WO2016170795A1

WO2016170795A1 - Transmission belt

Info

Publication number: WO2016170795A1
Application number: PCT/JP2016/002147
Authority: WO
Inventors: 正吾小林; 鉄平中山; 大樹土屋; 奥野　茂樹; 博之橘
Original assignee: バンドー化学株式会社
Priority date: 2015-04-24
Filing date: 2016-04-21
Publication date: 2016-10-27
Also published as: CN107532681A; CN107532681B

Abstract

This transmission belt simultaneously satisfies a plurality of prescribed characteristics. The belt B is a transmission belt that is wound around pulleys and transmits power. Said belt has a layer comprising a rubber composition that contains cellulose-based fine fibers, and short fibers (16) having an average diameter of 1µm or greater.

Description

Transmission belt

The present invention relates to a transmission belt.

A short fiber is blended with a rubber composition constituting a rubber layer of a transmission belt. For example, Patent Document 1 discloses that at least a compression layer of a V-ribbed belt is constituted by a rubber composition containing carbon black and short fibers.

Japanese Patent Laid-Open No. 2014-167347

Transmission belts are required for various characteristics such as wear resistance, coefficient of friction, and suppression of adhesive wear. When carbon black and short fibers are blended and reinforced in the rubber composition constituting the belt, other characteristics tend to deteriorate if the blended amount is adjusted so as to satisfy certain characteristics.

Therefore, an object of the present invention is to provide a transmission belt that simultaneously satisfies a plurality of required characteristics.

The present invention is a transmission belt that is wound around a pulley and transmits power, and has a layer made of a rubber composition containing cellulosic fine fibers and short fibers having an average diameter of 1 μm or more.

According to the present invention, since it has a layer made of a rubber composition containing cellulosic fine fibers and other short fibers, a plurality of characteristics required for a transmission belt can be satisfied simultaneously.

FIG. 1 is a perspective view schematically showing an exemplary V-ribbed belt of the first and second embodiments. FIG. 2 is a cross-sectional view of a main part of the V-ribbed belt of the first and second embodiments. FIG. 3 is a first explanatory view showing a method for manufacturing the V-ribbed belt of the first and second embodiments. FIG. 4 is a second explanatory view showing the manufacturing method of the V-ribbed belt of the first and second embodiments. FIG. 5 is a third explanatory view showing the manufacturing method of the V-ribbed belt of the first and second embodiments. FIG. 6 is a fourth explanatory view showing the method for manufacturing the V-ribbed belts of the first and second embodiments. FIG. 7 is a fifth explanatory view showing the method for manufacturing the V-ribbed belt of the first and second embodiments. FIG. 8 is a sixth explanatory view showing the method for manufacturing the V-ribbed belt of the first and second embodiments. FIG. 9 is a pulley layout diagram of a traveling tester for measuring crack resistance life. FIG. 10 is a pulley layout diagram of the high tension belt running test machine. FIG. 11 is a diagram for explaining a method of measuring a friction coefficient. FIG. 12 is a diagram showing a pulley layout of an auxiliary drive belt transmission device for an automobile using the V-ribbed belt of the embodiment. FIG. 13 is a perspective view schematically showing an exemplary flat belt of the third embodiment. FIG. 14 is a first explanatory view showing the flat belt manufacturing method according to the third embodiment. FIG. 15 is a second explanatory view showing the flat belt manufacturing method according to the third embodiment. FIG. 16 is a third explanatory view showing the flat belt manufacturing method according to the third embodiment. FIG. 17 is a diagram showing the configuration of the friction coefficient measuring apparatus. FIG. 18 is a diagram showing a pulley layout of the belt running test machine for wear resistance evaluation. FIG. 19 is a diagram showing a pulley layout of a belt running test machine for evaluating bending fatigue resistance. FIG. 20 is a diagram showing a pulley layout of a belt running test machine for evaluating friction / wear characteristics. FIG. 21 is a diagram showing a pulley layout of a belt running tester for wear resistance evaluation. FIG. 22 is a perspective view schematically showing an exemplary toothed belt according to the fourth embodiment. FIG. 23 is a partial cross-sectional view of a belt forming die used for manufacturing the toothed belt of the fourth embodiment. FIG. 24 is a first explanatory view of the manufacturing method of the toothed belt according to the fourth embodiment. FIG. 25 is a second explanatory view of the manufacturing method of the toothed belt according to the fourth embodiment. FIG. 26 is a third explanatory view of the manufacturing method of the toothed belt according to the fourth embodiment. FIG. 27 is a first explanatory view of the manufacturing method of the toothed belt according to the fifth embodiment. FIG. 28 is a second explanatory view of the manufacturing method of the toothed belt of the fifth embodiment. FIG. 29 is a third explanatory view of the manufacturing method of the toothed belt of the fifth embodiment. FIG. 30 is a cross-sectional view showing an interface structure between the tooth side reinforcing cloth and the toothed belt body in the seventh embodiment. FIG. 31 is a cross-sectional view showing an interface structure between a tooth portion side reinforcing cloth and a toothed belt body in the eighth embodiment. FIG. 32 is a diagram showing a pulley layout in a belt running tester for evaluating tooth chipping resistance and wear resistance of a toothed belt.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[Embodiment 1]
(V-ribbed belt B)
1 and 2 show a V-ribbed belt B according to the first embodiment. The V-ribbed belt B according to the first embodiment is an endless power transmission member used, for example, in an accessory drive belt transmission device provided in an engine room of an automobile. The V-ribbed belt B according to Embodiment 1 has, for example, a belt length of 700 to 3000 mm, a belt width of 10 to 36 mm, and a belt thickness of 4.0 to 5.0 mm.

The V-ribbed belt B according to the first embodiment is configured in a three-layer structure including a compression rubber layer 11 that constitutes a pulley contact portion on the inner peripheral side of the belt, an intermediate adhesive rubber layer 12, and a back rubber layer 13 on the outer peripheral side of the belt. A rubber V-ribbed belt body 10 is provided. A core wire 14 is embedded in an intermediate portion in the thickness direction of the adhesive rubber layer 12 in the V-ribbed belt body 10 so as to form a spiral having a pitch in the belt width direction. A back reinforcing cloth may be provided instead of the back rubber layer 13, and the V-ribbed belt main body 10 may be configured as a double layer of the compression rubber layer 11 and the adhesive rubber layer 12.

The compression rubber layer 11 is provided such that a plurality of V ribs 16 hang down to the inner peripheral side of the belt. The plurality of V ribs 16 are each formed in a ridge having a substantially inverted triangular cross section extending in the belt length direction, and provided in parallel in the belt width direction. Each V-rib 16 has, for example, a rib height of 2.0 to 3.0 mm and a width between base ends of 1.0 to 3.6 mm. The number of V ribs 16 is, for example, 3 to 6 (six in FIG. 1). The adhesive rubber layer 12 is formed in a band shape having a horizontally long cross section and has a thickness of, for example, 1.0 to 2.5 mm. The back rubber layer 13 is also formed in a band shape having a horizontally long cross section, and has a thickness of, for example, 0.4 to 0.8 mm. It is preferable that a woven fabric pattern is provided on the surface of the back rubber layer 13 from the viewpoint of suppressing the generation of sound during back driving.

The compressed rubber layer 11, the adhesive rubber layer 12, and the back rubber layer 13 are rubbers obtained by crosslinking an uncrosslinked rubber composition obtained by mixing and kneading various rubber compounding ingredients with a rubber component and then crosslinking with a crosslinking agent. It is formed with a composition. The rubber composition forming the compressed rubber layer 11, the adhesive rubber layer 12, and the back rubber layer 13 may be the same or different.

Examples of the rubber component of the rubber composition forming the compression rubber layer 11, the adhesive rubber layer 12, and the back rubber layer 13 include ethylene / propylene copolymer (EPR), ethylene / propylene / diene terpolymer (EPDM), Examples include ethylene-α-olefin elastomers such as octene copolymer and ethylene / butene copolymer; chloroprene rubber (CR); chlorosulfonated polyethylene rubber (CSM); hydrogenated acrylonitrile rubber (H-NBR). The rubber component is preferably one or more of these blend rubbers. The rubber components of the rubber composition forming the compressed rubber layer 11, the adhesive rubber layer 12, and the back rubber layer 13 are preferably the same.

At least one of the rubber compositions forming the compressed rubber layer 11, the adhesive rubber layer 12, and the back rubber layer 13 contains cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm. It is preferable that all the rubber compositions forming the compressed rubber layer 11, the adhesive rubber layer 12, and the back rubber layer 13 contain such cellulosic fine fibers, but at least the compressed rubber layer 11 constituting the pulley contact portion is formed. It is more preferable that the rubber composition to be contained contains such cellulosic fine fibers.

Cellulosic fine fiber is a fiber material derived from cellulose fine fiber composed of a skeletal component of a plant cell wall obtained by finely loosening plant fiber. Examples of the cellulosic fine fiber plant include wood, bamboo, rice (rice straw), potato, sugar cane (bagasse), aquatic plants, and seaweed. Of these, wood is preferred. When the porous rubber composition forming the surface rubber layer 11a contains such cellulosic fine fibers, the high reinforcing effect is exhibited.

The cellulose-based fine fiber may be either the cellulose fine fiber itself or a hydrophobic cellulose fine fiber that has been subjected to a hydrophobic treatment. Moreover, you may use together cellulose fine fiber itself and hydrophobized cellulose fine fiber as a cellulosic fine fiber. From the viewpoint of dispersibility, the cellulosic fine fibers preferably include hydrophobized cellulose fine fibers. Examples of the hydrophobized cellulose fine fibers include cellulose fine fibers in which some or all of the hydroxyl groups of cellulose are substituted with hydrophobic groups, and cellulose fine fibers that have been subjected to a hydrophobized surface treatment with a surface treatment agent.

Examples of hydrophobization for obtaining cellulose fine fibers in which part or all of the hydroxyl groups of cellulose are substituted with hydrophobic groups include esterification (acylation) (alkyl esterification, complex esterification, β-ketoesterification, etc.) ), Alkylation, tosylation, epoxidation, arylation and the like. Of these, esterification is preferred. Specifically, in the esterified hydrophobized cellulose fine fiber, part or all of the hydroxyl groups of cellulose are carboxylic acids such as acetic acid, acetic anhydride, propionic acid, butyric acid, or halides thereof (particularly chlorides). It is the cellulose fine fiber acylated by. Examples of the surface treatment agent for obtaining cellulose fine fibers hydrophobized and surface-treated with the surface treatment agent include silane coupling agents.

From the viewpoint of realizing the belt characteristics, the lower limit of the fiber diameter distribution of the cellulosic fine fibers is preferably 10 nm or less, more preferably 3 nm or less. The upper limit is preferably 500 nm or more, more preferably 700 nm or more, and further preferably 1 μm or more. The distribution range of the fiber diameter of the cellulosic fine fibers is preferably 20 to 500 nm, more preferably 20 to 700 mm, and still more preferably 20 nm to 1 μm.

The average fiber diameter of the cellulosic fine fibers is preferably 3 nm or more and 200 nm or less, more preferably 3 nm or more and 100 nm or less.

The distribution of the fiber diameter of the cellulosic fine fibers is determined by observing the cross section with a transmission electron microscope (TEM) after freezing and pulverizing a sample of the rubber composition constituting the belt main body. The fiber diameter is measured by arbitrarily selecting and obtained based on the measurement result. The average fiber diameter of the cellulosic fine fibers is obtained as the number average of the fiber diameters of 50 arbitrarily selected cellulosic fine fibers.

The cellulosic fine fibers may be either high aspect ratio manufactured by mechanical defibrating means, or manufactured by chemical defibrating means. Of these, those produced by chemical defibrating means are preferred. Moreover, you may use together what was manufactured by the mechanical defibration means, and what was manufactured by the chemical defibration means as a cellulose fine fiber. Examples of the defibrating apparatus used for the mechanical defibrating means include a kneader such as a twin-screw kneader, a high-pressure homogenizer, a grinder, and a bead mill. Examples of the treatment used for the chemical defibrating means include acid hydrolysis treatment.

The content of the cellulosic fine fibers in the rubber composition constituting the compressed rubber layer 11, the adhesive rubber layer 12, and / or the back rubber layer 13 is 100 parts by mass of the rubber component from the viewpoint of satisfying various characteristics of the transmission belt. On the other hand, it is preferably 1 part by mass or more, more preferably 5 parts by mass or more, further preferably 10 parts by mass or more, and preferably 30 parts by mass or less, more preferably 25 parts by mass or less, still more preferably 20 parts by mass. Or less.

Also, examples of rubber compounding agents include reinforcing materials, oils, processing aids, vulcanization acceleration aids, crosslinking agents, co-crosslinking agents, and vulcanization accelerators.

Short fibers used as a reinforcing material in addition to cellulosic fine fibers include, for example, 6-nylon fiber, 6,6-nylon fiber, 4,6-nylon fiber, polyethylene terephthalate (PET) fiber, polyethylene naphthalate (PEN) Examples thereof include fibers, para-aramid fibers, meta-aramid fibers, and polyester fibers. Only a single species may be included, or a plurality of species may be included. The short fiber is manufactured by, for example, cutting a long fiber, which has been subjected to an adhesion treatment to be heated after being immersed in an RFL aqueous solution, into a predetermined length.

The diameter of the short fiber is preferably 1 μm or more, more preferably 5 μm or more, still more preferably 10 μm or more, and preferably 100 μm or less, more preferably 70 μm or less, and even more preferably 50 μm or less.

The blend amount of the short fibers is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and preferably 50 parts by mass or less, more preferably 100 parts by mass of the rubber component of the rubber composition. It is 40 parts by mass or less.

As a reinforcing material, carbon black, for example, channel black; furnace black such as SAF, ISAF, N-339, HAF, N-351, MAF, FEF, SRF, GPF, ECF, N-234; FT, MT, etc. Thermal black; acetylene black etc. are mentioned.

When cellulosic fine fibers are used, carbon black is not necessarily added, but may be added for the purpose of antistatic or the like. When added, the amount of carbon black is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and preferably 100 parts by mass or less, with respect to 100 parts by mass of the rubber component of the rubber composition. More preferably, it is 50 parts by mass or less.

Oils include, for example, petroleum-based softeners, mineral oils such as paraffin wax, castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, palm oil, fall raw oil, wax, rosin, pine And vegetable oils such as oil. The oil is preferably one or more of these. The oil content is, for example, 5 to 15 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

Examples of the vulcanization acceleration aid include metal oxides such as zinc oxide (zinc white) and magnesium oxide, metal carbonates, fatty acids and derivatives thereof. Among these, the vulcanization acceleration aid is preferably one or more. The content of the vulcanization acceleration aid is, for example, 5 to 15 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

Examples of the crosslinking agent include sulfur and organic peroxides. As a crosslinking agent, sulfur may be blended, an organic peroxide may be blended, or both of them may be used in combination. The compounding amount of the crosslinking agent is, for example, 0.5 to 4.0 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition in the case of sulfur, and the rubber component 100 of the rubber composition in the case of an organic peroxide. For example, 0.5 to 8.0 parts by mass with respect to parts by mass.

Examples of the organic peroxide include dialkyl peroxides such as dicumyl peroxide, peroxyesters such as t-butyl peroxyacetate, and ketone peroxides such as dicyclohexanone peroxide. The organic peroxide may be a single species or a plurality of species.

Examples of the co-crosslinking agent include maleimide, TAIC, 1,2-polybutadiene, oximes, guanidine, and trimethylolpropane trimethacrylate. The co-crosslinking agent is preferably one or more of these. The content of the co-crosslinking agent is, for example, 0.5 to 15 parts by mass with respect to 100 parts by mass of the rubber component.

The adhesive rubber layer 12 and the back rubber layer 13 are solid rubber compositions in which an uncrosslinked rubber composition in which various rubber compounding agents are blended with a rubber component and kneaded is heated and pressurized to be crosslinked with the crosslinking agent. Is formed. Examples of the rubber component of the rubber composition constituting the adhesive rubber layer 12 and the back rubber layer 13 include the same rubber components as those of the compressed rubber layer 11 and may be the same. As the rubber compounding agent, as in the case of the compressed rubber layer 11, a reinforcing material, oil, a processing aid, a vulcanization acceleration aid, a crosslinking agent, a co-crosslinking agent, a vulcanization accelerator, and the like can be given. Further, the rubber composition constituting the adhesive rubber layer 12 and the back rubber layer 13 may contain cellulosic fine fibers and short fibers in the same manner as the compressed rubber layer 11.

The core wire 14 is composed of a wire such as a twisted yarn or a braid of polyethylene terephthalate (PET) fiber, polyethylene naphthalate (PEN) fiber, para-aramid fiber, vinylon fiber, or the like. In order to give the core wire 14 adhesion to the V-ribbed belt main body 10, an adhesive treatment that is heated after being immersed in an RFL aqueous solution before molding and / or an adhesive treatment that is dried after being immersed in rubber paste is performed. In addition, the core 14 is subjected to an adhesive treatment that is heated after being immersed in an adhesive solution made of a solution such as an epoxy resin or a polyisocyanate resin, if necessary, before the adhesive treatment with the RFL aqueous solution and / or the rubber paste. It may be. The diameter of the core wire 14 is, for example, 0.5 to 2.5 mm, and the dimension between the centers of the adjacent core wires 14 in the cross section is, for example, 0.05 to 0.20 mm.

(Manufacturing method of V-ribbed belt B)
A method for manufacturing the V-ribbed belt B according to the first embodiment will be described with reference to FIGS.

3 and 4 show a belt forming die 30 used for manufacturing the V-ribbed belt B according to the first embodiment.

The belt mold 30 is provided with a cylindrical inner mold 31 and an outer mold 32 which are provided concentrically.

The inner mold 31 is made of a flexible material such as rubber. The outer mold 32 is made of a rigid material such as metal. The inner peripheral surface of the outer mold 32 is formed as a molding surface, and V rib forming grooves 33 having the same shape as the V ribs 16 are provided on the inner peripheral surface of the outer mold 32 at a constant pitch in the axial direction. Yes. The outer mold 32 is provided with a temperature control mechanism that controls the temperature by circulating a heat medium such as water vapor or a coolant such as water. Further, a pressurizing means for pressurizing and expanding the inner mold 31 from the inside is provided.

The manufacturing method of the V-ribbed belt B according to Embodiment 1 includes a material preparation process, a molding process, a crosslinking process, and a finishing process.

<Material preparation process>
-Uncrosslinked rubber sheets 11 ', 12', 13 'for compressed rubber layer, adhesive rubber layer, and back rubber layer
Of the uncrosslinked rubber sheets 11 ′, 12 ′, and 13 ′ for the compressed rubber layer, the adhesive rubber layer, and the back rubber layer, those containing cellulosic fine fibers are produced as follows.

First, cellulosic fine fibers are put into a kneaded rubber component and dispersed by kneading.

Here, as a method for dispersing the cellulose-based fine fibers in the rubber component, for example, a dispersion (gel) in which the cellulose-based fine fibers are dispersed in water is added to the rubber component kneaded with an open roll, A method of vaporizing moisture while kneading them, a master of cellulose fine fibers / rubber obtained by mixing a dispersion (gel) in which cellulosic fine fibers are dispersed in water and rubber latex to vaporize the moisture Obtained by mixing the batch into a rubber component that has been masticated, mixing a dispersion in which cellulosic fine fibers are dispersed in a solvent and a solution in which the rubber component is dissolved in the solvent, and evaporating the solvent Cellulose fine fiber / rubber masterbatch is put into the kneaded rubber component, dispersion (gel) in which cellulose fine fiber is dispersed in water is freeze-dried and pulverized And what, how to put into a rubber component is masticated, methods and the like to introduce cellulosic microfibers made hydrophobic in rubber component is masticated.

Next, while kneading the rubber component and the cellulosic fine fiber, various rubber compounding agents are added and kneading is continued to prepare an uncrosslinked rubber composition.

Then, the uncrosslinked rubber composition is molded into a sheet by calendar molding or the like.

In addition, the preparation of those not containing cellulosic fine fibers is carried out by blending various rubber compounding agents with the rubber component, kneading with a kneader such as a kneader or a Banbury mixer, and the resulting uncrosslinked rubber composition by calendar molding or the like. This is done by forming into a sheet.

-Core 14'-
An adhesive treatment is applied to the core wire 14 '. Specifically, the core wire 13 'is subjected to an RFL adhesion treatment in which it is immersed in an RFL aqueous solution and heated. Moreover, it is preferable to perform the foundation | substrate adhesion | attachment process which immerses in a foundation | substrate adhesion | attachment processing liquid and heats before RFL adhesion | attachment processing. In addition, you may give the rubber paste adhesion | attachment process which is immersed in rubber glue and dried before RFL adhesion | attachment processing.

<Molding process>
As shown in FIG. 5, a rubber sleeve 35 is placed on a cylindrical drum 34 having a smooth surface, and an uncrosslinked rubber sheet 13 ′ for the back rubber layer and an uncrosslinked rubber sheet 12 for the adhesive rubber layer are formed on the outer periphery thereof. 'Are wound in order and laminated, and the core wire 14' is wound spirally around the cylindrical inner mold 31 from above, and the uncrosslinked rubber sheet 12 'for the adhesive rubber layer and the compressed rubber layer are further wound thereon. The uncrosslinked rubber sheet 11 ′ for use is wound in order. At this time, a laminated molded body B ′ is formed on the rubber sleeve 35.

<Crosslinking process>
The rubber sleeve 35 provided with the laminated molded body B ′ is removed from the cylindrical drum 34 and, as shown in FIG. 6, it is set in the inner peripheral surface side of the outer mold 32 and then, as shown in FIG. The inner mold 31 is positioned and sealed in the rubber sleeve 35 set on the outer mold 32.

Next, the outer mold 32 is heated and pressurized by injecting high-pressure air or the like into the sealed interior of the inner mold 31. At this time, the inner mold 31 expands, and the uncrosslinked rubber sheets 11 ′, 12 ′, and 13 ′ in the laminated molded body B ′ enter the molded surface of the outer mold 32 while being compressed, and the crosslinking proceeds. In addition, the core wire 14 'is combined and integrated, and finally a cylindrical belt slab S is formed as shown in FIG. The molding temperature of the belt slab S is, for example, 100 to 180 ° C., the molding pressure is, for example, 0.5 to 2.0 MPa, and the molding time is, for example, 10 to 60 minutes.

<Finishing process>
The inside of the inner mold 31 is decompressed to release the seal, the belt slab S molded between the inner mold 31 and the outer mold 32 is taken out via the rubber sleeve 35, and the belt slab S is cut into a predetermined width and turned upside down. V-ribbed belt B is manufactured by turning over.

-Example-
[Test Evaluation 1]
Low edge V belts of Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-8 were produced using a rubber composition containing chloroprene rubber (also referred to as CR rubber) as a rubber component. Details of each are also shown in Table 1.

<Example 1-1>
CR latex (made by Showa Denko Co., Ltd., trade name: Shoprene 842A) and cellulose fine fiber (manufactured by Daio Paper Co., Ltd.) manufactured by mechanical defibration means are mixed, and water is evaporated to produce cellulose fine fiber / A master batch of CR was prepared.

Subsequently, CR (Showa Denko Co., Ltd., trade name: Showpren GS) was masticated, and a master batch was added thereto for kneading. The input amount of the master batch was such that the content of the cellulosic fine fibers was 20 parts by mass when the total CR was 100 parts by mass.

Then, CR and cellulosic fine fibers are kneaded, and there are 20 parts by mass of reinforcing material carbon black HAF (product name: SEAST 3), 100 parts by mass of CR, and aramid short fibers (Teijin). 5 parts by mass of Technora (registered trademark) oil (trade name: Samper 2280 manufactured by Nippon San Oil Co., Ltd.), 5 parts by mass of zinc oxide (manufactured by Sakai Chemical Industry Co., Ltd.), magnesium oxide ( 4 parts by mass of Kyowa Chemical Industry Co., Ltd. (trade name: Kyowa Mug 150) was added and kneading was continued to prepare an uncrosslinked rubber composition.

This uncrosslinked rubber composition was molded into a sheet to form an uncrosslinked rubber sheet for constituting a belt body (compressed rubber layer, adhesive rubber layer and stretched rubber layer), and a low edge V belt of Example 1-1 was produced. did.

In addition, the strand made from the polyester fiber which gave the adhesion process was used for the core wire.

<Example 1-2>
10 parts by weight of cellulose fine fibers produced by chemical defibration means (TEMPO oxidation treatment), 20 parts by weight of carbon black HAF as a reinforcing material, and 5 parts by weight of oil are added to CR and 100 parts by weight of CR. An uncrosslinked rubber composition was prepared by kneading 5 parts by mass of zinc oxide as a sulfur accelerator and 4 parts by mass of magnesium oxide and reducing the pressure.

A low-edge V belt of Example 1-2 having the same configuration as Example 1-1 was produced except that this uncrosslinked rubber composition was used as an uncrosslinked rubber sheet for constituting the belt body.

<Example 1-3>
About the uncrosslinked rubber sheet for forming the belt main body, the content of the cellulosic fine fibers not blended with carbon black and defibrated by chemical means is 20 parts by mass with respect to 100 parts by mass of the rubber component. Except for this, the belt of Example 1-3 having the same configuration as that of Example 1-2 was produced.

<Example 1-4>
The uncrosslinked rubber sheet for constituting the belt main body was cut into 3 mm length from a tire short made of nylon short fiber (nylon 66 made by Toray Industries, Inc.) with 10 parts by weight of aramid short fibers per 100 parts by weight of the rubber component. A belt of Example 1-4 having the same configuration as Example 1-2 was prepared except that 10 parts by mass of short fiber) was further blended.

<Example 1-5>
The belt of Example 1-5 having the same configuration as Example 1-2, except that 20 parts by mass of nylon short fibers were blended in place of 20 parts by mass of aramid short fibers for the uncrosslinked rubber sheet for constituting the belt body. Was made.

<Comparative Example 1-1>
With respect to the uncrosslinked rubber sheet for constituting the belt main body, a belt of Comparative Example 1-1 having the same constitution as that of Example 1-1 was produced, except that no cellulosic fine fibers were blended.

<Comparative Example 1-2>
Comparative Example 1-2 having the same configuration as Comparative Example 1-1, except that the amount of carbon black HAF was 70 parts by mass with respect to 100 parts by mass of the rubber component for the uncrosslinked rubber sheet for the belt body configuration A belt was prepared.

<Comparative Example 1-3>
The belt of Comparative Example 1-3 having the same configuration as that of Comparative Example 1-1, except that 20 parts by mass of nylon short fibers were blended in place of 20 parts by mass of aramid short fibers for the uncrosslinked rubber sheet for constituting the belt body. Was made.

<Comparative Example 1-4>
About the uncrosslinked rubber sheet for the belt body constitution, the blending amount of carbon black HAF is 70 parts by weight with respect to 100 parts by weight of the rubber component, and 20 parts by weight of nylon short fibers are blended instead of 20 parts by weight of aramid short fibers. A belt of Comparative Example 1-4 having the same configuration as that of Comparative Example 1-2 was produced.

<Comparative Example 1-5>
For the uncrosslinked rubber sheet for constituting the belt body, 20 parts by mass of cellulose fibers (made by Daio Paper Co., Ltd., kraft pulp) that are not fine fibers (fiber diameter of about 10 to 100 μm) are further blended with 100 parts by mass of the rubber component. A belt of Comparative Example 1-5 having the same configuration as that of Comparative Example 1-1 was produced.

<Comparative Example 1-6>
With respect to the uncrosslinked rubber sheet for constituting the belt body, Comparative Example 1 except that carbon black HAF is not blended and 20 parts by mass of cellulose fibers that are not fine fibers are further blended with 100 parts by mass of the rubber component. A belt of Comparative Example 1-6 having the same configuration as that of No. 5 was produced.

<Comparative Example 1-7>
With respect to the uncrosslinked rubber sheet for constituting the belt main body, a belt of Comparative Example 1-7 having the same constitution as that of Example 1-2 was produced except that aramid short fibers were not blended.

<Comparative Example 1-8>
With respect to the uncrosslinked rubber sheet for constituting the belt main body, a belt of Comparative Example 1-8 having the same constitution as Example 1-2 was produced except that neither carbon black HAF nor aramid short fibers were blended.

(Test evaluation method)
Each evaluation result is shown in Table 1.

<Average fiber diameter / fiber diameter distribution>
After freezing and pulverizing the samples of the inner rubber layers of the belts of Examples 1-1 to 1-5, the cross section was observed with a transmission electron microscope (TEM), and 50 cellulose fine fibers were arbitrarily selected. Then, the fiber diameter was measured, and the number average was obtained to obtain the average fiber diameter. Moreover, the maximum value and minimum value of the fiber diameter were calculated | required among 50 cellulose fine fibers.

<Crack resistance evaluation belt running test>
The crack life of the belt is an index indicating the crack resistance of rubber, and the longer the life is, the better.

FIG. 9 shows a running test machine 40 for measuring crack resistance life. The crack running evaluation belt running test machine 40 includes a drive pulley 41 having a pulley diameter of φ40 mm and a driven pulley 42 having a pulley diameter of 40 mm provided on the right side thereof. The driven pulley 42 is movably provided to the left and right so as to apply an axial load (dead weight DW) and apply tension to the low edge V-belt B.

About each belt of Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-8, the belt is wound around the driving pulley 41 and the driven pulley 42 of the traveling test machine 40, and the belt is driven to the right side with respect to the driven pulley 42. A belt load was applied by applying an axial load of 600 N to the belt and rotating the driving pulley 41 at a rotational speed of 3000 rpm under an ambient temperature of 100 ° C. The belt travel was periodically stopped and whether or not cracks occurred in the low edge V-belt B was visually confirmed, and the belt travel time until the occurrence of cracks was confirmed as the crack-resistant life. In addition, when generation | occurrence | production of the crack was not recognized over 200 hours, the test was stopped at that time.

<High tension belt running test>
High tension durability evaluation under dead weight conditions is effective as an accelerated evaluation of belt performance and life. The change in the distance between the shafts before and after the traveling becomes larger as the change in the belt length due to the permanent elongation of the core wire is considered to be constant, the greater the permanent set and wear of the rubber member. Therefore, the smaller the change in the inter-axis distance before and after traveling, the better. The change in the belt mass before and after running becomes an index indicating the wear resistance of the rubber member, and the smaller the better.

FIG. 10 shows a high tension belt running test machine 50.

The high tension belt running test machine 50 having a biaxial layout includes a driving V pulley 51 having a pulley diameter of φ100 mm and a driven V pulley 52 having a pulley diameter of 60 mm provided on the right side thereof. The driven V pulley 52 is movably provided to the left and right so as to apply an axial load (dead weight DW) and apply tension to the belt.

For each belt B of Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-4, the mass was measured before running to obtain an initial mass.

Thereafter, the belt was attached to the high tension belt running test machine 50, and the following inter-axial load was applied to the driven pulley. That is, examples in which aramid short fibers are blended alone (Examples 1-1 to 1-3, Comparative Examples 1-1 and 1-2) are examples in which both 1000N, both aramid short fibers and nylon short fibers are blended (implementation) In Example 1-4, Comparative Examples 1-5 and 1-6), 800 N is used, and in the case of blending nylon short fibers alone (Example 1-5, Comparative Examples 1-3 and 1-4), 500 N is used. In the case of not blending (Comparative Examples 1-7 and 1-8), it is 500N.

First, the ambient temperature was set to 100 ° C., no load was applied, the drive pulley was run at 5000 rpm for 10 minutes, the distance between the axes was measured, and the initial distance between the axes was obtained.

Thereafter, the drive V pulley 51 was rotated at 5000 rpm with the following load applied to the driven V pulley 52. In other words, examples in which aramid short fibers are blended alone (Examples 1-1 to 1-3, Comparative Examples 1-1 and 1-2) are examples in which both 40Nm, both aramid short fibers and nylon short fibers are blended (implementation) In Examples 1-4 and Comparative Examples 1-5 and 1-6), 30 Nm and Nylon short fibers were blended alone (Example 1-5, Comparative Examples 1-3 and 1-4), 20 Nm, short fibers In the case of not blending (Comparative Examples 1-7 and 1-8), it is 20 Nm.

In all cases, after traveling for 200 hours, the distance between the axes when further traveling for 10 minutes with no load was measured, and the distance between the axes after traveling was measured.

The distance change (%) between the axes after running was calculated as follows.

Axle distance change (%)
= (Distance between axes after running-Distance between axes before running) / Distance between axes before running x 100
Further, the weight of the belt after running was measured and used as the belt weight after durability. The belt weight change was calculated as follows.

Belt weight change (%)
= (Belt weight before running-belt weight after running) / belt weight before running x 100
However, in Comparative Examples 1-7 and 1-8, the belt was cut in a short time (about 30 minutes) after the start of running, and measurement related to the high tension running test was impossible.

<Friction coefficient>
FIG. 11 shows a friction coefficient measuring apparatus.

The friction coefficient measuring device 40 includes a test pulley 82 made of a rib pulley having a pulley diameter of 75 mm and a load cell 83 provided on the side thereof. The test pulley 82 is made of an iron-based material S45C. The low-edge V-belt test piece 81 is provided so that the test piece 81 extends horizontally from the load cell 83 and is then wound around the test pulley 82, that is, the winding angle around the test pulley 82 is 90 °.

Each of the non-running low-edge V belts of Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-4 was cut to produce a test piece 81 of a low-edge V-belt piece, and one end of the load cell 83 was provided at one end. A weight 84 was attached to the other end and suspended. Subsequently, at an atmospheric temperature of 25 ° C., the test pulley 82 is rotated at a rotation speed of 43 rpm in a direction to lower the weight 84, and at 60 seconds after the rotation starts, the test pulley 82 in the test piece 81 is loaded by the load cell 83. The tension Tt applied to the horizontal portion between the load cell 83 and the load cell 83 was measured. The tension Ts applied to the vertical portion between the test pulley 82 and the weight 84 of the test piece 81 was 17.15 N corresponding to the weight of the weight 84. Then, the friction coefficient μ at the time of drying the surface of the compressed rubber layer was obtained by the following formula (1) based on the Euler formula. Note that θ = π / 2.

In addition, the same test was performed on the low edge V belt after the high tension belt running test, and the friction coefficient during drying of the surface of the inner rubber layer was obtained. Then, the ratio of the friction coefficient at the time of drying after traveling to the friction coefficient at the time of drying without traveling (friction coefficient (after traveling) / friction coefficient (not traveling)) was obtained. The ratio of the friction coefficient before and after the running is an indicator of the change in the friction coefficient. The closer the ratio is to 1, the more stable the transmission characteristics are.

<Adhesive wear>
After the high-tension belt running test, the belt was removed from the high-tension belt running test machine 50, and it was visually confirmed whether or not adhesive wear of rubber occurred on the pulley contact portion and the pulley surface.

The presence / absence of adhesive wear after the high-tension running test is an index indicating the adhesive wear resistance of rubber. Occurrence of adhesive wear causes abnormal noise of the belt, vibration, sticking to the pulley, and the like, and it is preferable that the abrasion is not generated.

<Strong retention>
After the high-tensile belt running test, a belt tensile test was performed, and the strength after running per cord was measured by dividing the belt breaking strength by the number of cords driven into the fractured portion.

Also, the strength per belt of the same lot before running was measured in the same manner, and the strength retention of the belt was obtained as follows. The results are shown in Table 1.

Strong belt retention (%)
= Power per core after driving / Power per core before driving x 100
The strength retention of the belt after the high-tension running test is an index indicating the magnitude of damage to the tensile body (core wire) by the test. In the case of V-belts, the strain on the core wire increases due to increased local strain on the core wire due to buckling due to permanent deformation of the bottom rubber, and reduced winding diameter around the pulley due to rubber wear. Damage. Further, if the friction coefficient of rubber increases and the pull-out property from the pulley when the belt comes out of the pulley is deteriorated, reverse bending stimulation is applied and the fatigue of the core wire is promoted. Since such a thing works in combination, it can be judged that the higher the strength retention rate of the belt, the higher the performance of the rubber covering the core wire.

(Test evaluation results)
The test results are shown in Table 1.

According to Table 1, it can be seen that the cellulose fine fibers of Examples 1-1 to 1-5 all have a wide fiber diameter distribution.

In Examples 1-1 to 1-5 in which the cellulosic fine fibers and other short fibers are used in combination, the belt crack resistance life is 200 hours or more. In addition, after the high tension running test, the change in the distance between the shafts is 1 to 2%, the change in the belt weight is 2 to 3%, there is no adhesive wear, and the strength retention of the belt is 88 to 90%. Furthermore, the ratio of the coefficient of friction before and after the high tension running test is 0.95. In each Example, although the kind of cellulosic fine fiber (mechanical defibration and chemical defibration) and the kind of short fiber (aramid short fiber and nylon short fiber) differ, all are good results. In the case of Example 1-3, carbon black is not blended, and the blending amount of the cellulosic fine fibers is higher than in other examples (1-2, 1-4, 1-5) using the same type of cellulosic fine fibers. Is increasing. That is, the carbon black is completely replaced by the cellulosic fine fibers. In this case as well, the result is the same as in the other examples, and it is possible to obtain a rubber composition that does not use carbon black.

On the other hand, Comparative Examples 1-1 to 1-4 are belts made of rubber that is reinforced with short aramid fibers or short nylon fibers but does not contain cellulosic fine fibers.

For Comparative Examples 1-1 and 1-3 in which the blending amount of carbon black is 20 parts by mass, the crack resistance life of the belt is 200 hours or more, which is equivalent to that of the example, there is no adhesive wear, and the friction coefficient ratio is 0. .9, which is relatively close to the embodiment. However, the mass change of the belt before and after the high tension running test is 20%, and the wear resistance of the rubber is extremely bad. As a result, the change in the inter-axis distance is as large as 20%. Furthermore, the strength retention after running is extremely low at 31 or 33%. This is considered that the fatigue of the core wire was promoted by the poor pullability from the pulley due to the friction coefficient being too high and the buckling deformation of the rubber.

On the contrary, in Comparative Examples 1-2 and 1-4 in which the amount of carbon black was increased to 70 parts by mass, the wear resistance of the rubber (belt mass change) was improved to 3%, but the crack resistance life of the belt was improved. Worsens to 10 or 20. Further, the change in the distance between the belt axes is increased by 10%, which seems to be caused by a large permanent set of rubber due to the high self-heating during running. Further, adhesive wear occurs and the coefficient of friction changes. The belt strength retention after running is as low as 42 or 48%. This is considered that the fatigue of the core wire was promoted by the deterioration of the pull-out property from the pulley due to the increase of the friction coefficient and the self-heating of the rubber.

Next, Comparative Examples 1-5 and 1-6 are examples in which kraft pulp was used as cellulose having a larger size in place of cellulosic fine fibers. The difference between Comparative Example 1-5 and Comparative Example 1-6 is the presence or absence of carbon black. In both examples, both the crack resistance life and the wear resistance are deteriorated. Further, the belt strength retention is low, and the fatigue of the core wire is promoted. This is considered to be the same reason as in Comparative Examples 1-1 and 1-3.

Comparative Examples 1-7 and 1-8 are examples in which cellulosic fine fibers are blended and reinforcement with short fibers is not performed. The difference between Comparative Example 1-7 and Comparative Example 1-8 is the presence or absence of carbon black. In both examples, the belt crack resistance is good at 200 hours or more, but the belt breaks in a short time in the high tension running test, which is a high tension and high load condition, and the results of each item are measured. It was impossible. This is considered that the elastic modulus of the bottom rubber is insufficient and the rubber is buckled.

As described above, as in Comparative Examples 1-1 to 1-8, reinforcement by the combined use of carbon black and short fibers (nylon short fibers, aramid short fibers), and reinforcement by cellulose fibers that are not fine fibers (mixing of carbon black) In addition, the use of cellulosic fine fibers but the use of other short fibers (including the presence or absence of carbon black) does not satisfy all of the performances studied. could not. In particular, under the high temperature atmosphere (100 ° C.) as in the test conditions of the present example, it is impossible to satisfy the performance, and it is necessary to limit the use conditions to the low temperature side.

On the other hand, by replacing part or all of the carbon black with cellulosic fine fibers and using it together with reinforcement with short fibers, all the performances studied can be satisfied simultaneously. Moreover, this is realized under high temperature conditions as in this embodiment.

Although the elucidation of this specific mechanism is awaited, it is conceivable that the reinforcement form is different between the reinforcement by the cellulosic fine fibers and the reinforcement by the carbon black. That is, the carbon black reinforcement is manifested by the rubber layer (bound rubber) adsorbed by the carbon black being suppressed in the rubber mobility. Further, it is considered that no chemical cross-linking occurs in the rubber layer, and it is considered that exothermicity increases or adhesive wear occurs during repeated deformation. On the other hand, the details of the reinforcement by the cellulosic fine fibers are unknown, so this result is difficult to predict. However, as a consideration from the results, the rubber molecules in the vicinity of the cellulosic fine fibers are not suppressed as much as the rubber molecules in the vicinity of the carbon black, or are crosslinked and become rubber-like elastic bodies. There is a possibility that the nature of can be kept. The reinforcing effect by the cellulosic fine fibers may be due to the three-dimensional network structure of the fine fibers. However, the mechanism is not particularly concerned with the effect of the combined use of the cellulosic fine fibers and the short fibers.

In addition, Example 1-1 which mix | blended the cellulose fine fiber by 20 mass parts mechanical defibration means with respect to 100 mass parts of rubber components, and the cellulose fine fiber by the chemical defibration means of 10 mass parts similarly. Each evaluation is substantially the same about the blended Example 1-2. Therefore, the same effect can be realized with a small amount of the cellulose-based fine fibers obtained by the chemical defibrating means.

[Test evaluation 2]
Belts of Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-8 were produced using a rubber composition containing hydrogenated NBR (H-NBR) as a rubber component. Details of each are also shown in Table 2.

<Example 2-1>
H-NBR latex (trade name: ZLX-B, manufactured by Nippon Zeon Co., Ltd.) and an aqueous dispersion of cellulose fine fibers produced by mechanical defibration means are mixed, and water is vaporized to produce cellulose fine fibers / H-NBR. A master batch was prepared.

Subsequently, H-NBR (trade name: Zettopol 2020, manufactured by Nippon Zeon Co., Ltd.) was masticated, and a master batch was added thereto for kneading. The input amount of the master batch was such that the content of the fine cellulose fiber was 20 parts by mass when the total H-NBR was 100 parts by mass.

Then, H-NBR and fine cellulose fibers are kneaded, and there are 20 parts by mass of carbon black HAF as a reinforcing material, 20 parts by mass of aramid short fibers, and 10 parts by mass of oil with respect to 100 parts by mass of H-NBR. Kneading by adding 5 parts by mass of an organic peroxide as a crosslinking agent (trade name: Peroximone F40, manufactured by NOF Corporation) and 1 part by mass of a co-crosslinking agent (trade name: high cloth M, manufactured by Seiko Chemical Co., Ltd.). By continuing, an uncrosslinked rubber composition was produced.

This uncrosslinked rubber composition is molded into a sheet to form an uncrosslinked rubber sheet for constituting a belt body (compressed rubber layer, adhesive rubber layer and stretched rubber layer), and a low edge V belt of Example 2-1 is produced. did.

<Example 2-2>
10 parts by mass of cellulose fine fiber produced by chemical defibration means (TEMPO oxidation treatment), 20 parts by mass of carbon black HAF as a reinforcing material, 10 parts by mass of oil, and crosslinking with respect to 100 parts by mass of CR and its CR 5 parts by weight of the organic peroxide and 1 part by weight of the co-crosslinking agent were added and kneaded to prepare an uncrosslinked rubber composition.

A low-edge V belt of Example 2-2 having the same configuration as that of Example 2-1 was produced except that this uncrosslinked rubber composition was used as an uncrosslinked rubber sheet for constituting the belt body.

<Example 2-3>
About the uncrosslinked rubber sheet for the belt main body constitution, the content of the cellulosic fine fiber not blended with carbon black and defibrated by chemical means is 20 parts by mass with respect to 100 parts by mass of the rubber component. Except for this, the belt of Example 2-3 having the same configuration as that of Example 2-2 was produced.

<Example 2-4>
With respect to the uncrosslinked rubber sheet for constituting the belt body, Example 2-2 except that 10 parts by mass of aramid short fibers and 10 parts by mass of nylon short fibers were further blended with respect to 100 parts by mass of the rubber component. A belt of Example 2-4 having the same configuration was produced.

<Example 2-5>
The belt of Example 2-5 having the same configuration as Example 2-2, except that 20 parts by mass of nylon short fibers were blended in place of 20 parts by mass of aramid short fibers for the uncrosslinked rubber sheet for constituting the belt body. Was made.

<Comparative Example 2-1>
With respect to the uncrosslinked rubber sheet for constituting the belt main body, Example 2-1 except that the blending amount of the carbon black HAF is 30 parts by mass with respect to 100 parts by mass of the rubber component, and no cellulosic fine fibers are blended. A belt of Comparative Example 2-1 having the same configuration was produced.

<Comparative Example 2-2>
Comparative Example 2-2 having the same configuration as Comparative Example 2-1 except that the amount of carbon black HAF was 90 parts by mass with respect to 100 parts by mass of the rubber component for the uncrosslinked rubber sheet for the belt body configuration A belt was prepared.

<Comparative Example 2-3>
The belt of Comparative Example 2-3 having the same configuration as that of Comparative Example 2-1 except that 20 parts by mass of nylon short fibers were blended in place of 20 parts by mass of aramid short fibers for the uncrosslinked rubber sheet for constituting the belt body. Was made.

<Comparative Example 2-4>
About the uncrosslinked rubber sheet for the belt body constitution, the blending amount of carbon black HAF is 90 parts by weight with respect to 100 parts by weight of the rubber component, and 20 parts by weight of nylon short fibers are blended instead of 20 parts by weight of aramid short fibers. A belt of Comparative Example 2-4 having the same configuration as that of Comparative Example 2-1 was produced.

<Comparative Example 2-5>
About the uncrosslinked rubber sheet for the belt body constitution, the blending amount of carbon black HAF is 20 parts by mass with respect to 100 parts by mass of the rubber component, and 20 parts by mass of cellulose fibers that are not fine fibers with respect to 100 parts by mass of the rubber component A belt of Comparative Example 2-5 having the same configuration as that of Comparative Example 2-1 was prepared, except that was further blended.

<Comparative Example 2-6>
Comparative Example 2 except that the uncrosslinked rubber sheet for constituting the belt main body was not compounded with carbon black HAF, and further blended 20 parts by mass of cellulose fibers that were not fine fibers with respect to 100 parts by mass of the rubber component. A belt of Comparative Example 2-5 having the same configuration as that of 1 was produced.

<Comparative Example 2-7>
With respect to the uncrosslinked rubber sheet for constituting the belt main body, a belt of Comparative Example 2-7 having the same constitution as that of Example 2-2 was produced except that an aramid short fiber was not blended.

<Comparative Example 2-8>
A belt of Comparative Example 2-8 having the same configuration as that of Example 2-2 was produced except that neither carbon black HAF nor short aramid fibers were blended in the uncrosslinked rubber sheet for constituting the belt main body.

(Test evaluation method)
For each belt of Examples 2-1 to 2-5, the average value, the minimum value, and the maximum value of the fiber diameter of the fine cellulose fibers were determined in the same manner as in Test Evaluation 1. In addition, for each belt of Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-8, as in Test Evaluation 1, the belt crack life was measured and a high-tension running test was performed to check the shaft. The change in distance, the change in mass, the wear coefficient ratio, the presence or absence of adhesive wear after the test, and the strength retention were evaluated.

However, the atmospheric temperature was set to 120 ° C. for the measurement of the belt crack resistance and the high tension running test. Further, the belt anti-cracking life was measured up to 300 hours, and the test was terminated if no cracks were observed after 300 hours.

(Test evaluation results)
The test results are shown in Table 2.

According to Table 2, it can be seen that the same results as in Test Evaluation 1 were obtained even when the rubber component was H-NBR. In particular, although the atmospheric temperature in the crack resistance evaluation belt running test and the high tension belt running test is higher (120 ° C.) than in test evaluation 1, a good evaluation result is obtained. For this reason, one possibility is that the reinforcing effect of the cellulosic fine fibers is less temperature-dependent than the reinforcing effect of carbon black.

[Test Evaluation 3]
Belts for test evaluation of Examples 3-1 to 3-5 and Comparative Examples 3-1 to 3-8 were produced using a rubber composition containing EPDM as a rubber component. Details of each are also shown in Table 3.

<Example 3-1>
A dispersion in which fine cellulose fibers produced by mechanical defibrating means are dispersed in toluene and a solution in which EPDM (trade name: EP33 manufactured by JSR) is dissolved in toluene are mixed, and toluene is vaporized to mix cellulose. A fine fiber / EPDM masterbatch was prepared.

Next, EPDM was masticated, and a master batch was added thereto for kneading. The input amount of the masterbatch was such that the content of cellulose fine fibers was 20 parts by mass when the total EPDM was 100 parts by mass.

Then, while EPDM and cellulose fine fiber are kneaded, with respect to 100 parts by mass of EPDM, 20 parts by mass of carbon black as a reinforcing material, 20 parts by mass of aramid short fibers, 10 parts by mass of oil, and organic of a crosslinking agent An uncrosslinked rubber composition was prepared by adding 5 parts by weight of a peroxide and 1 part by weight of a co-crosslinking agent and continuing kneading.

This uncrosslinked rubber composition was molded into a sheet to form an uncrosslinked rubber sheet for constituting a belt body (compressed rubber layer, adhesive rubber layer and stretched rubber layer), and a low edge V belt of Example 3-1 was produced. did.

<Example 3-2>
10 parts by mass of cellulose fine fiber produced by chemical defibration means (TEMPO oxidation treatment), 20 parts by mass of carbon black as a reinforcing material, 10 parts by mass of oil, and organic peroxidation of a crosslinking agent with respect to 100 parts by mass of EPDM 5 parts by mass of the product and 1 part by mass of the co-crosslinking agent were kneaded to prepare an uncrosslinked rubber composition.

A low-edge V belt of Example 3-2 having the same configuration as that of Example 3-1 was produced except that this uncrosslinked rubber composition was used as an uncrosslinked rubber sheet for constituting the belt body.

<Example 3-3>
About the uncrosslinked rubber sheet for the belt main body constitution, the content of the cellulosic fine fiber not blended with carbon black and defibrated by chemical means is 20 parts by mass with respect to 100 parts by mass of the rubber component. A belt of Example 3-3 having the same configuration as that of Example 3-2 was produced.

<Example 3-4>
With respect to the uncrosslinked rubber sheet for constituting the belt main body, Example 3-2 except that 10 parts by mass of aramid short fibers and 10 parts by mass of nylon short fibers were further blended with respect to 100 parts by mass of the rubber component. A belt of Example 3-4 having the same configuration was produced.

<Example 3-5>
The belt of Example 3-5 having the same configuration as that of Example 3-2 except that 20 parts by mass of nylon short fibers were blended in place of 20 parts by mass of aramid short fibers for the uncrosslinked rubber sheet for constituting the belt body. Was made.

<Comparative Example 3-1>
With respect to the uncrosslinked rubber sheet for constituting the belt main body, Example 3-1, except that the blending amount of the carbon black HAF is 30 parts by mass with respect to 100 parts by mass of the rubber component and no cellulosic fine fibers are blended. A belt of Comparative Example 3-1 having the same configuration was produced.

<Comparative Example 3-2>
Comparative Example 3-2 having the same configuration as Comparative Example 3-1, except that the amount of carbon black HAF was 90 parts by mass with respect to 100 parts by mass of the rubber component for the uncrosslinked rubber sheet for the belt body configuration A belt was prepared.

<Comparative Example 3-3>
The belt of Comparative Example 3-3 having the same configuration as Comparative Example 3-1, except that 20 parts by mass of nylon short fibers were blended in place of 20 parts by mass of aramid short fibers for the uncrosslinked rubber sheet for the belt body configuration Was made.

<Comparative Example 3-4>
About the uncrosslinked rubber sheet for the belt body constitution, the blending amount of carbon black HAF is 90 parts by weight with respect to 100 parts by weight of the rubber component, and 20 parts by weight of nylon short fibers are blended instead of 20 parts by weight of aramid short fibers. A belt of Comparative Example 3-4 having the same configuration as that of Comparative Example 3-1 was produced.

<Comparative Example 3-5>
About the uncrosslinked rubber sheet for the belt body constitution, the blending amount of carbon black HAF is 20 parts by mass with respect to 100 parts by mass of the rubber component, and 20 parts by mass of cellulose fibers that are not fine fibers with respect to 100 parts by mass of the rubber component A belt of Comparative Example 3-5 having the same configuration as that of Comparative Example 3-1 was produced, except that was further blended.

<Comparative Example 3-6>
With respect to the uncrosslinked rubber sheet for constituting the belt body, Comparative Example 3 except that carbon black HAF was not blended and 20 parts by mass of cellulose fibers that were not fine fibers were further blended with respect to 100 parts by mass of the rubber component. A belt of Comparative Example 3-5 having the same configuration as 1 was produced.

<Comparative Example 3-7>
A belt of Comparative Example 3-7 having the same configuration as that of Example 3-2 was prepared for the uncrosslinked rubber sheet for constituting the belt body, except that aramid short fibers were not blended.

<Comparative Example 3-8>
A belt of Comparative Example 3-8 having the same configuration as Example 3-2 was produced except that neither carbon black HAF nor aramid short fibers were blended in the uncrosslinked rubber sheet for constituting the belt main body.

(Test evaluation method)
For each belt of Examples 3-1 to 3-5, the average value, the minimum value, and the maximum value of the fiber diameter of the cellulose fine fiber were determined in the same manner as in Test Evaluation 1. In addition, for each belt of Examples 3-1 to 3-5 and Comparative Examples 3-1 to 3-8, as in Test Evaluation 1, a belt crack resistance life was measured and a high-tension running test was performed. The change in distance, the change in mass, the wear coefficient ratio, the presence or absence of adhesive wear after the test, and the strength retention were evaluated.

(Test evaluation results)
The test results are shown in Table 3.

According to Table 3, it can be seen that the same results as in Test Evaluations 1 and 2 were obtained even when the rubber component was EPDM. In particular, although the atmospheric temperature in the crack resistance evaluation belt running test and the high tension belt running test is higher (120 ° C.) than in test evaluation 1, a good evaluation result is obtained.

[Embodiment 2]
(V-ribbed belt B)
1 and 2 are also diagrams showing a V-ribbed belt B according to the second embodiment. The V-ribbed belt B according to the second embodiment is an endless power transmission member used, for example, in an accessory drive belt transmission device provided in an engine room of an automobile. The V-ribbed belt B according to Embodiment 2 has, for example, a belt length of 700 to 3000 mm, a belt width of 10 to 36 mm, and a belt thickness of 4.0 to 5.0 mm.

The V-ribbed belt B according to the second embodiment has a three-layer structure including a compression rubber layer 11 that forms a pulley contact portion on the belt inner peripheral side, an intermediate adhesive rubber layer 12, and a back rubber layer 13 on the belt outer peripheral side. A rubber V-ribbed belt body 10 is provided. A core wire 14 is embedded in an intermediate portion in the thickness direction of the adhesive rubber layer 12 in the V-ribbed belt body 10 so as to form a spiral having a pitch in the belt width direction. A back reinforcing cloth may be provided instead of the back rubber layer 13, and the V-ribbed belt main body 10 may be configured as a double layer of the compression rubber layer 11 and the adhesive rubber layer 12.

According to the V-ribbed belt B according to the second embodiment, at least one of the rubber compositions forming the compression rubber layer 11, the adhesive rubber layer 12, and the back rubber layer 13 that constitutes the V-ribbed belt main body 10 as described above is a fiber. By containing a cellulosic fine fiber having a diameter distribution range of 50 to 500 nm, excellent bending fatigue resistance can be obtained. Moreover, when the rubber composition which forms the compression rubber layer 11 which comprises a contact part contains such a cellulose fine fiber, a stable friction coefficient can be obtained with high abrasion resistance.

Cellulosic fine fiber is a fiber material derived from cellulose fine fiber composed of a skeletal component of a plant cell wall obtained by finely loosening plant fiber. Examples of the cellulosic fine fiber plant include wood, bamboo, rice (rice straw), potato, sugar cane (bagasse), aquatic plants, seaweed and the like. Of these, wood is preferred.

The cellulosic fine fibers preferably have a wide fiber diameter distribution from the viewpoint of enhancing bending fatigue resistance, and the fiber diameter distribution range includes 50 to 500 nm. From the viewpoint, the lower limit of the fiber diameter distribution is preferably 20 nm or less, more preferably 10 nm or less. From the same viewpoint, the upper limit is preferably 700 nm or more, more preferably 1 μm or more. The fiber diameter distribution range of the cellulosic fine fibers preferably includes 20 nm to 700 mm, and more preferably includes 10 nm to 1 μm.

The average fiber diameter of the cellulosic fine fibers contained in the rubber composition is preferably 10 nm or more, more preferably 20 nm or more, and preferably 700 nm or less, more preferably 100 nm or less.

The distribution of the fiber diameter of the cellulosic fine fibers is obtained by freezing and crushing a sample of the rubber composition, then observing the cross section with a transmission electron microscope (TEM) and arbitrarily selecting 50 cellulosic fine fibers. The fiber diameter is measured and obtained based on the measurement result. The average fiber diameter of the cellulosic fine fibers is obtained as the number average of the fiber diameters of 50 arbitrarily selected cellulosic fine fibers.

The cellulosic fine fibers may be either high aspect ratio manufactured by mechanical defibrating means, or needle-shaped crystals manufactured by chemical defibrating means. Of these, those manufactured by mechanical defibrating means are preferred. Moreover, you may use together what was manufactured by the mechanical defibration means, and what was manufactured by the chemical defibration means as a cellulose fine fiber. Examples of the defibrating apparatus used for the mechanical defibrating means include a kneader such as a twin-screw kneader, a high-pressure homogenizer, a grinder, and a bead mill. Examples of the treatment used for the chemical defibrating means include acid hydrolysis treatment.

The content of the cellulosic fine fibers in the rubber composition is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and still more preferably 5 parts with respect to 100 parts by mass of the rubber component from the viewpoint of enhancing the bending fatigue resistance. It is not less than 30 parts by mass, preferably not more than 30 parts by mass, more preferably not more than 20 parts by mass, and still more preferably not more than 10 parts by mass.

Examples of rubber compounding agents include reinforcing materials, process oils, processing aids, vulcanization acceleration aids, crosslinking agents, vulcanization accelerators, and anti-aging agents.

As the reinforcing material, carbon black, for example, channel black; furnace black such as SAF, ISAF, N-339, HAF, N-351, MAF, FEF, SRF, GPF, ECF, N-234; FT, MT, etc. Thermal black; acetylene black and the like. Silica is also mentioned as the reinforcing material. It is preferable that a reinforcing material is 1 type, or 2 or more types among these. The content of the reinforcing material is preferably 50 to 90 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

Oils include, for example, petroleum-based softeners, mineral oils such as paraffin wax, castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, palm oil, fall raw oil, wax, rosin, pine And vegetable oils such as oil. The oil is preferably one or more of these. The oil content is, for example, 10 to 30 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

Examples of processing aids include stearic acid, polyethylene wax, and fatty acid metal salts. Among these, the processing aid is preferably one or more. The content of the processing aid is, for example, 0.5 to 2 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

Examples of the vulcanization acceleration aid include metal oxides such as magnesium oxide and zinc oxide (zinc white), metal carbonates, fatty acids and derivatives thereof. Among these, the vulcanization acceleration aid is preferably one or more. The content of the vulcanization acceleration aid is, for example, 3 to 7 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

Examples of the anti-aging agent include benzimidazole anti-aging agents, amine-ketone anti-aging agents, diamine anti-aging agents, and phenol anti-aging agents. It is preferable that an anti-aging agent is 1 type, or 2 or more types among these. The content of the anti-aging agent is, for example, 0.1 to 5 parts by mass with respect to 100 parts by mass of the rubber component.

Examples of the co-crosslinking agent include maleimide, TAIC, 1,2-polybutadiene, oximes, guanidine, trimethylolpropane trimethacrylate, and liquid rubber. The co-crosslinking agent is preferably one or more of these. The content of the co-crosslinking agent is, for example, 0.5 to 30 parts by mass with respect to 100 parts by mass of the rubber component.

Examples of the crosslinking agent include sulfur and organic peroxides. As a crosslinking agent, sulfur may be blended, an organic peroxide may be blended, or both of them may be used in combination. The amount of the crosslinking agent is, for example, 1 to 5 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition in the case of sulfur, and 100 parts by mass of the rubber component of the rubber composition with respect to the organic peroxide. For example, 1 to 5 parts by mass.

Examples of the vulcanization accelerator include thiuram (eg, TETD, TT, TRA, etc.), thiazole (eg, MBT, MBTS, etc.), sulfenamide (eg, CZ), dithiocarbamate (eg, BZ-P). Etc.). It is preferable that a vulcanization accelerator is 1 type, or 2 or more types among these. The content of the vulcanization accelerator is, for example, 1 to 3 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

The rubber composition forming the compressed rubber layer 11, the adhesive rubber layer 12, and the back rubber layer 13 may contain short fibers 16 having a fiber diameter of 10 μm or more. In particular, the short fiber 16 is preferably contained in the rubber composition forming the compressed rubber layer 11 constituting the pulley contact portion. In that case, the short fibers 16 are preferably contained in the compressed rubber layer 11 so as to be oriented in the belt width direction, and the short fibers 16 exposed on the surface of the V ribs 15 of the compressed rubber layer 11 are partially Preferably protrudes from the surface. In addition, the structure by which the short fiber 16 was planted on the V-rib 15 surface of the compression rubber layer 11 instead of the structure in which the short fiber 16 was mix | blended with the rubber composition may be sufficient.

Examples of the short fibers 16 include nylon short fibers, vinylon short fibers, aramid short fibers, polyester short fibers, and cotton short fibers. The short fiber 16 is manufactured by, for example, cutting a long fiber that has been subjected to an adhesion treatment to be heated after being immersed in an RFL aqueous solution or the like into a predetermined length. The length of the short fiber 16 is, for example, 0.2 to 5.0 mm, and the fiber diameter is, for example, 10 to 50 μm.

The content of the short fibers 16 is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and preferably 30 parts by mass or less, more preferably 20 parts by mass or less, with respect to 100 parts by mass of the rubber component. It is. The content of the short fibers 16 is preferably larger than the content of the cellulosic fine fibers. The ratio of the content of the short fibers 16 to the content of the cellulosic fine fibers (the content of the cellulosic fine fibers of the content of the short fibers 16) is preferably 1 or more, more preferably 2 or more, and preferably Is 15 or less, more preferably 5 or less. The total content of cellulosic fine fibers and short fibers 16 is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and preferably 25 parts by mass or less, with respect to 100 parts by mass of the rubber component. Preferably it is 15 mass parts or less.

The core wire 14 is composed of a twisted yarn formed of polyamide fiber, polyester fiber, aramid fiber, polyamide fiber or the like. The diameter of the core wire 14 is, for example, 0.5 to 2.5 mm, and the dimension between the centers of the adjacent core wires 14 in the cross section is, for example, 0.05 to 0.20 mm. The core wire 14 is subjected to an adhesive treatment for imparting adhesiveness to the V-ribbed belt main body 10.

Next, FIG. 12 shows a pulley layout of the auxiliary drive belt transmission device 20 for an automobile using the V-ribbed belt B according to the second embodiment. The accessory drive belt transmission device 20 is of a serpentine drive type in which a V-ribbed belt B is wound around six pulleys of four rib pulleys and two flat pulleys to transmit power.

In this accessory drive belt transmission device 20, a rib pulley power steering pulley 21 is provided at the uppermost position, and a rib pulley AC generator pulley 22 is provided below the power steering pulley 21. A flat pulley tensioner pulley 23 is provided at the lower left of the power steering pulley 21, and a flat pulley water pump pulley 24 is provided below the tensioner pulley 23. Further, a rib pulley crankshaft pulley 25 is provided on the lower left side of the tensioner pulley 23, and a rib pulley air conditioner pulley 26 is provided on the lower right side of the crankshaft pulley 25. These pulleys are made of, for example, a metal stamped product, a casting, or a resin molded product such as nylon resin or phenol resin, and have a pulley diameter of φ50 to 150 mm.

In this accessory drive belt transmission device 20, the V-ribbed belt B is wound around the power steering pulley 21 so that the V-rib 16 side contacts, and then wound around the tensioner pulley 23 so that the back surface of the belt contacts. After that, it is wound around the crankshaft pulley 25 and the air conditioner pulley 26 in order so that the V rib 16 side comes into contact, and further wound around the water pump pulley 24 so that the back surface of the belt comes into contact. Thus, it is wound around the AC generator pulley 22 and finally returned to the power steering pulley 21. The belt span length, which is the length of the V-ribbed belt B spanned between the pulleys, is, for example, 50 to 300 mm. Misalignment that can occur between pulleys is 0-2 °.

(Manufacturing method of V-ribbed belt B)
The manufacturing method of the V-ribbed belt B according to the second embodiment is the same as that of the V-ribbed belt according to the first embodiment.

-Example-
[V-ribbed belt]
V-ribbed belts of Examples 4-1 to 4-9 and Comparative Example 4 below were produced. Details of each are also shown in Table 4.

<Example 4-1>
Prepare a dispersion in which powdered cellulose (trade name: KC Flock W-50GK, manufactured by Nippon Paper Industries Co., Ltd.) made of wood as a raw material in toluene is dispersed. The fine fibers were defibrated to obtain a dispersion in which cellulose fine fibers were dispersed in toluene. Accordingly, the cellulose fine fibers are produced by mechanical defibrating means and are not subjected to a hydrophobic treatment.

Next, the dispersion in which cellulose fine fibers are dispersed in toluene is mixed with a solution in which ethylene propylene diene monomer (trade name: EP33, manufactured by JSR Corporation, hereinafter referred to as “EPDM”) is dissolved in toluene, and the toluene is vaporized. Thus, a master batch of cellulose fine fiber / EPDM was prepared.

Subsequently, EPDM was masticated, and a master batch was added thereto for kneading. The input amount of the master batch was such that the cellulose fine fiber content was 1 part by mass when the total EPDM was 100 parts by mass.

Then, EPDM and fine cellulose fibers are kneaded, and 60 mass parts of HAF carbon black (trade name: Dia Black H) manufactured by Mitsubishi Chemical Co., Ltd. is added to 100 mass parts of EPDM. Name: 15 parts by weight of sampler 2280), 1 part by weight of stearic acid (manufactured by Shin Nippon Rika Co., Ltd., trade name: stearic acid 50S) as processing aid, zinc oxide (product of Sakai Chemical Co., Ltd.) as vulcanization accelerator Name: 5 parts by mass of zinc oxide (3 types), 2.5 parts by mass of benzimidazole anti-aging agent (trade name: NOCRACK MB), sulfur as a crosslinking agent (product by Hosoi Chemical Co., Ltd.) Name: oil sulfur) 2.3 parts by mass, and thiuram vulcanization accelerator (made by Ouchi Shinsei Chemical Co., Ltd., trade name: Noxeller TET-G) To prepare uncrosslinked rubber composition by continuing kneading the.

Using this uncrosslinked rubber composition, a V-ribbed belt of Example 4-1 having the same configuration as that of Embodiment 2 in which a compressed rubber layer was formed so that the cutting direction was the belt width direction was produced.

The V-ribbed belt of Example 4-1 has a belt length of 1400 mm, a belt width of 2.2 mm, a belt thickness of 4.5 mm, and three V-ribs. The adhesive rubber layer and the back rubber layer were formed from a rubber composition not containing cellulose fine fibers and short fibers, and the core wire was formed from a polyester fiber twisted yarn that had been subjected to an adhesive treatment.

<Example 4-2>
A V-ribbed belt of Example 4-2 was produced in the same manner as in Example 4-1, except that the cellulose fine fiber content was 3 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 4-3>
A V-ribbed belt of Example 4-3 was produced in the same manner as in Example 4-1, except that the content of cellulose fine fibers was 5 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 4-4>
A V-ribbed belt of Example 4-4 was produced in the same manner as in Example 4-1, except that the cellulose fine fiber content was 10 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 4-5>
A V-ribbed belt of Example 4-5 was produced in the same manner as in Example 4-1, except that the content of cellulose fine fibers was 15 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 4-6>
A V-ribbed belt of Example 4-6 was produced in the same manner as in Example 4-1, except that the content of cellulose fine fibers was 25 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 4-7>
Except that the uncrosslinked rubber composition for the compression rubber layer contains 14 parts by mass of nylon short fibers (trade name: CFN3000, fiber diameter: 26 μm, fiber length: 3 mm, manufactured by Teijin Ltd.) with respect to 100 parts by mass of the rubber component. In the same manner as in Example 4-1, a V-ribbed belt of Example 4-7 was produced. The ratio of the short fiber content to the cellulosic fine fiber content (“B / A” in Table 4) is 14. The total content of cellulosic fine fibers and short fibers (“A + B” in Table 4) is 15 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 4-8>
The V of Example 4-8 is the same as Example 4-2, except that 12 parts by mass of nylon short fibers are added to 100 parts by mass of the rubber component in the uncrosslinked rubber composition for the compressed rubber layer. A ribbed belt was produced. The ratio (B / A) of the short fiber content to the cellulosic fine fiber content is 4. The total content (A + B) of the cellulosic fine fibers and short fibers is 15 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 4-9>
The V of Example 4-9 is the same as Example 4-3 except that the uncrosslinked rubber composition for the compressed rubber layer contains 10 parts by mass of nylon short fibers per 100 parts by mass of the rubber component. A ribbed belt was produced. The ratio of the short fiber content to the cellulosic fine fiber content (the short fiber content to the cellulosic fine fiber content) is 3. The total content of cellulosic fine fibers and short fibers is 15 parts by mass with respect to 100 parts by mass of the rubber component.

<Comparative example 4>
The same as in Example 4-1, except that the uncrosslinked rubber composition for the compressed rubber layer does not contain fine cellulose fibers and 15 parts by mass of nylon short fibers per 100 parts by mass of the rubber component. Thus, a V-ribbed belt of Comparative Example 4 was produced.

(Test evaluation method)
<Average fiber diameter / fiber diameter distribution>
Samples collected for the rubber composition forming the compressed rubber layer of each V-ribbed belt of Example 4-1 to Example 4-9 were freeze-ground and then the cross section was observed with a scanning electron microscope (SEM). , 50 fibers were arbitrarily selected, the fiber diameter was measured, and the number average was obtained to obtain the average fiber diameter. Moreover, the maximum value and minimum value of the fiber diameter were calculated | required among 50 cellulose fine fibers.

<Friction coefficient measurement test>
FIG. 17 shows the friction coefficient measuring device 140.

The friction coefficient measuring device 140 includes a test pulley 141 made of a rib pulley having a pulley diameter of 75 mm and a load cell 142 provided on the side thereof. The test pulley 141 is made of an iron-based material S45C. The test piece 143 of the V-ribbed belt extends horizontally from the load cell 142 and is then wound around the test pulley 141. That is, the V-ribbed belt test piece 143 is provided such that the winding angle around the test pulley 141 is 90 °.

About each of the V-ribbed belts of Example 4-1 to Example 4-9 and Comparative Example 4, a belt-like test piece 143 is cut, and one end thereof is fixed to the load cell 142 and wound around the test pulley 141. A weight 144 was attached to the other end and hung. Subsequently, at an ambient temperature of 25 ° C., the test pulley 141 is rotated at a rotation speed of 43 rpm in a direction to lower the weight 144, and at 60 seconds after the rotation starts, the test pulley 141 in the test piece 143 is loaded by the load cell 142. The tension Tt applied to the horizontal portion between the load cell 142 and the load cell 142 was measured. The tension Ts applied to the vertical part of the test pulley 141 and the weight 144 of the test piece 143 was 17.15 N corresponding to the weight of the weight 144. Then, the friction coefficient μ at the time of drying the surface of the compressed rubber layer was obtained by the following formula (1) based on the Euler formula. Note that θ = π / 2.

Also, water was interposed on the test pulley 141, the same test was carried out when it was dried, and the difference obtained by subtracting the friction coefficient at the time of drying from the friction coefficient at the time of drying was obtained.

<Abrasion resistance evaluation belt running test>
FIG. 18 shows a pulley layout of the abrasion resistance evaluation belt running test machine 150.

The belt running test machine 150 for wear resistance evaluation includes a driving rib pulley 151 having a pulley diameter of φ60 mm and a driven rib pulley 152 having a pulley diameter of 60 mm provided on the right side thereof. The driven rib pulley 152 is movably provided to the left and right so that an axial load (dead weight DW) can be applied and tension can be applied to the V-ribbed belt B.

For each of the V-ribbed belts of Examples 4-1 to 4-9 and Comparative Example 4, after measuring the belt mass, the belt is wound between the drive rib pulley 151 and the driven rib pulley 152 of the belt running test machine 150 for wear resistance evaluation. Hang and apply a shaft load of 490 N to the right side of the driven rib pulley 152 to apply tension to the V-ribbed belt B, and apply a rotational load of 5.9 kW (8 PS) to drive the driving rib pulley 151 at 3500 rpm in a normal temperature atmosphere. The belt was run at a rotational speed. Then, the belt running was stopped 24 hours after the start of running, the belt mass of the V-ribbed belt was measured, and the weight loss was obtained as a percentage.

<Bend fatigue test belt running test>
FIG. 19 shows a pulley layout of a belt running test machine 160 for evaluating bending fatigue resistance.

The belt running test machine 160 for evaluating bending fatigue resistance includes a driving rib pulley 161 having a pulley diameter of φ60 mm, a first driven rib pulley 162a having a pulley diameter of φ60 mm provided above, a driving rib pulley 161 and a first driven rib pulley 162a. Pulleys provided on the right side of the intermediate portion of the second driven rib pulley 162b having a pulley diameter of φ60 mm and on the right side of the intermediate portions of the drive rib pulley 161 and the first driven rib pulley 162a, respectively, And a pair of idler pulleys 163 having a diameter of 50 mm. The first driven rib pulley 162a is provided movably up and down so as to apply a shaft load (dead weight DW) and apply tension to the V-ribbed belt B. In this belt running test machine 160 for evaluating bending fatigue resistance, bending fatigue is accelerated by bending the V-ribbed belt B to the back side to increase the strain generated at the tip of the V-rib.

For each of the V-ribbed belts of Examples 4-1 to 4-9 and Comparative Example 4, the belt running tester 160 for evaluating bending fatigue resistance has a compression rubber layer as a driving rib pulley 161 and first and second driven rib pulleys. 162a and 162b, and the back rubber layer is wound around the idler pulley 163 so as to be in contact with each other, and an axial load of 588 N is applied to the first driven rib pulley 162a to apply tension to the V-ribbed belt B. The driving rib pulley 161 was rotated at a rotational speed of 5100 rpm under the atmospheric temperature of 70 ° C. to run the belt. The belt travel was periodically stopped and whether or not a crack was generated in the compressed rubber layer was visually confirmed, and the belt travel time until the occurrence of the crack was confirmed was defined as the crack generation life.

(Test evaluation results)
The test results are shown in Table 2. Hereinafter, the content of the cellulose fine fiber means a part by mass with respect to 100 parts by mass of the rubber component even if not particularly described.

<Average fiber diameter / fiber diameter distribution>
It can be seen that the cellulose fine fibers contained in the rubber compositions forming the compressed rubber layers of the V-ribbed belts of Examples 4-1 to 4-9 all have a wide fiber diameter distribution.

<Friction coefficient>
The friction coefficient of Comparative Example 4 was 0.6, whereas the friction coefficients of Examples 4-1 to 4-9 were in the range of 0.6 to 1.1, which was equivalent to Comparative Example 4 or It can be seen that it is somewhat larger than Comparative Example 4. However, for all of Examples 4-1 to 4-9, the amount of change (increase) between the friction coefficient at the time of drying and the friction coefficient at the time of drying is smaller than 0.9 in the case of Comparative Example 4. I understand that. In particular, Examples 4-3 to 4-6 in which the content of cellulose fine fibers is 5 parts by mass or more, and Examples 4-7 to Examples 4-6 including both cellulose fine fibers and short nylon fibers 9 shows that the increase amount is -0.05 to 0.05, which is close to 0, and therefore, the increase in the coefficient of friction during drying after being flooded is suppressed. Even in the case of Example 4-1 with the smallest content of cellulose fine fibers (1 part by mass), it can be seen that the change in the friction coefficient is 0.5, which is nearly half that of Comparative Example 4.

From the above, it can be seen that the change in the coefficient of friction after water exposure can be suppressed by incorporating fine cellulose fibers into the rubber composition forming the compressed rubber layer. This effect is exhibited both in the case of not containing nylon short fibers and containing only cellulose fine fibers, or in the case of containing both nylon short fibers and cellulosic fine fibers. is there.

<Abrasion resistance>
The weight loss of Comparative Example 4 was improved to 2.8% in Example 4-1 in which the content of cellulose fine fibers was 1 part by mass with respect to the wear rate of 3.2%, and the content of cellulose fine fibers was It can be seen that the wear resistance is improved as the value increases (in Examples 4-2 to 4-6, 2.7, 2.1, 1.9, 1.8, and 1.7 in order). However, it can be seen that when the content of the fine cellulose fiber exceeds 10 parts by mass, the improvement is small even if the content is further increased (Examples 4-4 to 4-6).

Moreover, the mass loss of the comparative example 4 in which 15 mass parts of nylon short fibers were contained was 3.2%, and in Example 4-1 in which the content of cellulose fine fibers was 1 mass part, 2.8%. In Example 4-7 in which the content of short nylon fibers is 14 parts by mass and the content of fine cellulose fibers is 1 part by mass, it is 2.3%. That is, it can be seen that the wear resistance is further improved by including both nylon short fibers and cellulose fine fibers. In Examples 4-7 to 4-9, the total content of cellulose fine fibers and short nylon fibers is the same, but the wear resistance improves as the proportion of the content of cellulose fine fibers increases. I understand.

<Bending fatigue resistance>
In Comparative Example 4 in which the content of short nylon fibers was 15 parts by mass, the crack generation life was 520 hours, whereas in Example 4-1, in which the content of cellulose fine fibers was 1 part by mass, cracks were observed. It can be seen that the generation life is 1205 hours, which is improved more than twice. It can be seen that the crack generation life is further improved by increasing the content of the cellulose fine fiber to 3 parts by mass (Example 4-2), but if it is further increased, the crack generation life is rather shortened (Example 4- 3 to Example 4-6). However, even in Example 4-6 in which the content of fine cellulose fibers is 25 parts by mass, the crack generation life is 900 hours, which is a significant improvement over Comparative Example 4.

It can be seen that even when cellulose fine fibers and nylon short fibers are used in combination, the bending fatigue resistance is improved as compared with Comparative Example 4. It can also be seen that the bending fatigue resistance improves as the proportion of the content of cellulose fine fibers increases (Examples 4-7 to 4-9).

As described above, by incorporating cellulose fine fibers into the rubber composition forming the compressed rubber layer, the friction coefficient stability (suppression of changes due to moisture), wear resistance, flex fatigue resistance, etc. have been improved. A V-ribbed belt can be produced.

[Embodiment 3]
(Flat Belt C)
FIG. 13 schematically shows a flat belt C according to the third embodiment. The flat belt C according to the third embodiment is used in applications that require a long life in use under relatively high load conditions such as a drive transmission application such as a blower, a compressor, and a generator, and an auxiliary machine drive application of an automobile. It is the power transmission member used. The flat belt C has, for example, a belt length of 600 to 3000 mm, a belt width of 10 to 20 mm, and a belt thickness of 2 to 3.5 mm.

The flat belt C according to the third embodiment is provided such that an inner rubber layer 121 on the inner peripheral side of the belt, an adhesive rubber layer 122 on the outer peripheral side of the belt, and an outer rubber layer 123 on the outer peripheral side of the belt are laminated. An integrated flat belt body 120 is provided. A core wire 124 is embedded in the adhesive rubber layer 122 so as to form a spiral having a pitch in the belt width direction at an intermediate portion in the belt thickness direction.

The inner rubber layer 121, the adhesive rubber layer 122, and the outer rubber layer 123 are each formed in a band shape having a horizontally long cross section, and an uncrosslinked rubber composition in which various compounding agents are blended and kneaded with a rubber component is heated. And it is formed with the rubber composition bridge | crosslinked by the crosslinking agent by being pressurized. The thickness of the inner rubber layer 121 is preferably 0.3 mm or more, more preferably 0.5 mm or more, and preferably 3.0 mm or less, more preferably 2.5 mm or less. The thickness of the adhesive rubber layer 122 is, for example, 0.6 to 1.5 mm. The thickness of the outer rubber layer 123 is, for example, 0.6 to 1.5 mm.

At least one of the rubber compositions forming the inner rubber layer 121, the adhesive rubber layer 122, and the outer rubber layer 123 contains cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm. It is preferable that all the rubber compositions forming the inner rubber layer 121, the adhesive rubber layer 122, and the outer rubber layer 123 contain such cellulosic fine fibers, but at least the rubber composition forming the inner rubber layer 121 is applied. It is more preferable to contain a cellulosic fine fiber.

The rubber composition that forms the inner rubber layer 121, the adhesive rubber layer 122, and the outer rubber layer 123 is the same as the rubber composition that forms the compression rubber layer 111, the adhesive rubber layer 112, and the back rubber layer 113 of the second embodiment. It has the composition of. Cellulose fine fibers also have the same configuration as that of the second embodiment.

The rubber composition forming the inner rubber layer 121, the adhesive rubber layer 122, and the outer rubber layer 123 may contain short fibers 126. In particular, the short rubber 126 is preferably contained in the rubber composition forming the inner rubber layer 121. In that case, the short fibers 126 are preferably contained in the inner rubber layer 121 so as to be oriented in the belt width direction. The short fiber 126 has the same configuration as that of the second embodiment.

Further, the core wire 124 has the same configuration as that of the second embodiment.

According to the flat belt C according to the third embodiment, at least one of the rubber compositions forming the inner rubber layer 121, the adhesive rubber layer 122, and the outer rubber layer 123 that constitutes the flat belt main body 120 in this way is a fiber. By containing a cellulosic fine fiber having a diameter distribution range of 50 to 500 nm, excellent bending fatigue resistance can be obtained. In particular, when the rubber composition forming the inner rubber layer 121 constituting the contact portion contains such cellulosic fine fibers, a high friction resistance and a stable friction coefficient can be obtained.

(Manufacturing method of flat belt C)
A method for manufacturing the flat belt C according to the third embodiment will be described with reference to FIGS. 14, 15, and 16.

The manufacturing method of the flat belt C according to Embodiment 3 includes a material preparation process, a molding process, a crosslinking process, and a finishing process.

<Material preparation process>
Among the uncrosslinked rubber sheets 121 ′, 122 ′, and 123 ′ for the inner rubber layer, the adhesive rubber layer, and the outer rubber layer, those containing cellulosic fine fibers are produced in the same manner as in the second embodiment. . In addition, the preparation of those not containing cellulosic fine fibers is carried out by blending various rubber compounding agents with the rubber component, kneading with a kneader such as a kneader or a Banbury mixer, and the resulting uncrosslinked rubber composition by calendar molding or the like. This is done by forming into a sheet.

Further, the bonding process is performed on the core wire 124 ′ in the same manner as in the second embodiment.

<Molding process>
As shown in FIG. 14A, after the uncrosslinked rubber sheet 121 ′ for the inner rubber layer is wound around the outer periphery of the cylindrical mold 145, the uncrosslinked rubber sheet 122 ′ for the adhesive rubber layer is wound thereon.

Next, as shown in FIG. 14 (b), a core wire 124 'is spirally wound on the uncrosslinked rubber sheet 122' for the adhesive rubber layer, and then again uncrosslinked for the adhesive rubber layer. A rubber sheet 122 'is wound.

Next, as shown in FIG. 14C, the uncrosslinked rubber sheet 123 'for the outer rubber layer is wound around the uncrosslinked rubber sheet 122' for the adhesive rubber layer. As a result, a laminated molded body C ′ is formed on the cylindrical mold 145.

<Crosslinking process>
Next, as shown in FIG. 15, after the laminated molded body C ′ on the cylindrical mold 145 is covered with a rubber sleeve 146, it is set in a vulcanizing can and sealed, and the cylindrical mold is heated with high-temperature steam or the like. While heating 145, high pressure is applied and the rubber sleeve 146 is pressed in the radial direction on the cylindrical mold 145 side. At this time, the uncrosslinked rubber composition of the laminated molded body C ′ flows, and the crosslinking reaction of the rubber component proceeds. In addition, the adhesion reaction of the core wire 124 ′ also proceeds. As a result, as shown in FIG. A cylindrical belt slab S is formed on the mold 145.

<Polishing and finishing process>
In the polishing and finishing process, the cylindrical mold 145 is taken out from the vulcanizing can, the cylindrical belt slab S formed on the cylindrical mold 145 is removed, and then the outer peripheral surface and / or the inner peripheral surface is polished. To make the thickness uniform.

Finally, a flat belt C is produced by cutting the belt slab S into a predetermined width.

-Example-
[Flat belt]
Flat belts of the following Example 5-1 to Example 5-6 and Comparative Example 5-1 to Comparative Example 5-2 were produced. Details of each are also shown in Table 5.

<Example 5-1>
A master batch of fine cellulose fiber / EPDM was produced in the same manner as in Example 4-1.

And while kneading EPDM and cellulose fine fiber, with respect to 100 parts by mass of EPDM, 40 parts by mass of HAF carbon black (trade name: Diamond Black H) manufactured by Mitsubishi Chemical Co., Ltd., process oil (product manufactured by Sun Oil Co., Ltd.) Name: Thumper 2280) 5 parts by mass, stearic acid as a processing aid (manufactured by Shin Nippon Chemical Co., Ltd., trade name: stearic acid 50S) 0.5 parts by mass, zinc oxide as a vulcanization accelerator (Sakai Chemical Co., Ltd.) Product name: Zinc oxide (3 types) 5 parts by mass, benzimidazole anti-aging agent (Ouchi Shinsei Chemical Co., Ltd., product name: NOCRACK MB) 2 parts by mass, and organic peroxide (JP An uncrosslinked rubber composition was prepared by adding 6 parts by mass of each product (trade name: Peroximon F-40, purity 40% by mass) manufactured by Oil Co. and continuing kneading.

Using this uncrosslinked rubber composition, a flat belt of Example 5-1 having the same configuration as that of Embodiment 3 in which the inner rubber layer was formed so that the line direction was the belt width direction was produced.

The V-ribbed belt of Example 5-1 had a belt length of 1118 mm, a belt width of 10 mm, and a belt thickness of 2.8 mm. The adhesive rubber layer and the outer rubber layer were formed of a rubber composition not containing fine cellulose fibers and short fibers, and the core wire was formed of a twisted yarn made of polyester fiber subjected to an adhesion treatment.

<Example 5-2>
A flat belt of Example 5-2 was produced in the same manner as in Example 5-1, except that the content of the fine cellulose fiber was 3 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 5-3>
A flat belt of Example 5-3 was produced in the same manner as in Example 5-1, except that the content of the fine cellulose fiber was 5 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 5-4>
A flat belt of Example 5-4 was produced in the same manner as in Example 5-1, except that the content of the cellulose fine fiber was 10 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 5-5>
A flat belt of Example 5-5 was produced in the same manner as in Example 5-1, except that the content of the fine cellulose fiber was 15 parts by mass with respect to 100 parts by mass of the rubber component.

<Example 5-6>
A flat belt of Example 5-6 was produced in the same manner as Example 5-1, except that the content of cellulose fine fibers was 25 parts by mass with respect to 100 parts by mass of the rubber component.

<Comparative Example 5-1>
A flat belt of Comparative Example 5-1 was produced in the same manner as in Example 5-1, except that cellulose fine fibers were not contained in the rubber composition forming the inner rubber layer.

<Comparative Example 5-2>
Except that the rubber composition forming the inner rubber layer does not contain fine cellulose fibers and 5 parts by mass of nylon short fibers with respect to 100 parts by mass of the rubber component, the same as Example 5-1. A flat belt of Comparative Example 5-2 was produced.

(Test evaluation method)
<Average fiber diameter / fiber diameter distribution>
Samples were collected from the rubber compositions forming the inner rubber layer of the flat belts of Examples 5-1 to 5-6, and the average fiber diameter of the cellulose fine fibers was measured in the same manner as in Test Evaluation 1. The maximum value and the minimum value of the fiber diameter were determined.

<Friction and wear characteristics evaluation belt running test>
FIG. 20 shows a pulley layout of the belt running test machine 170 for evaluating friction / wear characteristics.

The belt running test machine 170 for evaluating friction / wear characteristics includes a driving flat pulley 171 having a pulley diameter of 120 mm, a first driven flat pulley 172 having a pulley diameter of 120 mm provided above the right driving pulley 171 and a right at an intermediate position between them. And a second driven flat pulley 173 having a pulley diameter of φ50 mm provided on the side. The second driven flat pulley 173 is movably provided to the left and right so as to apply an axial load (dead weight DW) and apply tension to the flat belt C.

For each flat belt C of Example 5-1 to Example 5-6 and Comparative Example 5-1 to Comparative Example 5-2, the driving flat pulley 171 of the belt running test machine 170 for evaluating friction and wear characteristics, the first The second driven flat pulleys 72 and 73 are wound around, and a 98 N axial load is applied to the right side of the second driven flat pulley 173 to apply tension to the flat belt C. The belt was run by applying a rotational load of 8.8 kW and rotating the drive pulley 171 at a rotational speed of 4800 rpm under an ambient temperature of 120 ° C. Then, the belt running was stopped 24 hours after the running started, and the friction coefficient of the surface of the inner rubber layer after the belt running was obtained by the same method as in Test Evaluation 1 using the friction coefficient measuring device 140 shown in FIG. . As the test pulley 141, a flat pulley having a pulley diameter of φ65 mm was used.

In addition, the same test was performed with the belt running time set to 500 hours, and the amount of change in the friction coefficient was calculated when the belt running time was set to 24 hours.

Further, the running surface of the driving flat pulley 171 and the first and second driven flat pulleys 72 and 73 after the belt running for 24 hours is visually observed to perform a sensory evaluation of the surface state, and the state from the amount of rubber adhesion and texture The sticking wear occurrence index was numerically determined as follows.

When sticky eraser residue is attached: 100
When there is a powdery deposit: 50,
When there is no deposit: 0
Here, the rubber that is difficult to collect becomes powdery and tends to fall off the belt surface. Even if the wear resistance is good, if the state of the wear powder is poor, the wear powder becomes a foreign substance, and the product value is evaluated low.

<Abrasion resistance evaluation belt running test>
FIG. 21 shows a pulley layout of the belt running test machine 180 for evaluating wear resistance.

The belt running test machine 180 for wear resistance evaluation includes a driving flat pulley 181 having a pulley diameter of φ100 mm and a driven flat pulley 182 having a pulley diameter of 100 mm provided on the left side thereof. The driving flat pulley 181 is provided so as to be movable left and right so as to apply an axial load (dead weight DW) and apply tension to the flat belt C.

For each flat belt C of Example 5-1 to Example 5-6 and Comparative Example 5-1 to Comparative Example 5-2, the belt mass was measured, and then the belt running tester 180 for wear resistance evaluation was driven. Wrapped between the flat pulley 181 and the driven flat pulley 182 to apply a shaft load of 300 N to the right side of the driving flat pulley 181 to apply tension to the flat belt C, and rotate the driven flat pulley 182 by 12 N · m. Torque was applied, and the drive flat pulley 181 was rotated at a rotational speed of 2000 rpm under the atmospheric temperature of 100 ° C. to run the belt. Then, the belt running was stopped 24 hours after the start of running, the belt mass of the flat belt C was measured, the weight loss was determined, and the relative value was calculated with the weight loss of Comparative Example 5-1 being 100.

(Test evaluation results)
The test results are shown in Table 5. Hereinafter, the content of the cellulose fine fiber means a part by mass with respect to 100 parts by mass of the rubber component even if not particularly described.

<Average fiber diameter / fiber diameter distribution>
It can be seen that the cellulose fine fibers contained in the rubber composition forming the inner rubber layer of each flat belt of Example 5-1 to Example 5-6 all have a wide fiber diameter distribution.

<Friction and wear characteristics>
-Coefficient of friction-
The coefficient of friction after running the belt for 24 hours in Comparative Example 5-1 was 0.85, whereas in Example 5-1 and Example 5-2, the same coefficient was 0.85, which was 100 parts by weight of the rubber component. When the cellulose fine fiber content is about 1 to 3 parts by mass, no change is observed in the friction coefficient. It can be seen that when the content of the fine cellulose fiber is further increased (Examples 5-3 to 5-6), the content decreases somewhat, and at 25 parts by mass (Example 5-6), it is 0.6.

In addition, in the case of Comparative Example 5-2 in which 5 parts by mass of nylon short fibers are blended, the friction coefficient is 0.75, and the content of cellulose fine fibers is 10 parts by mass. Same as the case.

The friction coefficient after running the belt for 500 hours, compared with the friction coefficient after running the belt for 24 hours, decreases in order of 0.35 and 0.25 in Comparative Example 5-1 and Comparative Example 5-2. In Examples 5-1 to 5-6, the decrease is 0.15 at the maximum (Examples 5-1 and 2-2). When the content of cellulose fine fiber is increased, the decrease is further reduced. When the content is 10 parts by mass or more (Example 5-4 to Example 5-6), after running the belt for 24 hours and after running the belt for 500 hours. It can be seen that the coefficient of friction is the same value.

From the above, it can be seen that a flat belt having a small change in friction coefficient with time can be obtained by forming the inner rubber layer from a rubber composition containing fine cellulose fibers.

-Adhesive wear index-
In Comparative Examples 5-1 and 5-2, the adhesive wear occurrence index is evaluated as 100 and 90, whereas when a rubber composition containing cellulose fine fibers is used, the content is the smallest (1 (Mass part) In Example 5-1, the adhesive wear occurrence index is 45, which shows that it is remarkably improved. By increasing the content, the adhesive wear occurrence index was further improved, and in Example 5-6 containing 25 parts by mass of cellulose fine fibers, the evaluation was 10 (powder with less adhesion on the belt surface and low adhesive powder) It can be seen that there are many body-shaped ones).

In the case of Comparative Example 5-2 containing nylon short fibers, an improvement is seen as compared with Comparative Example 5-1, but this is not remarkable.

From the above, it can be seen that the adhesive wear occurrence index of the flat belt is improved by forming the inner rubber layer with the rubber composition containing cellulose fine fibers.

<Abrasion resistance>
The evaluation of abrasion resistance of Comparative Example 5-1 and Comparative Example 5-2 is 100, whereas Example 5-1 in which the content of cellulose fine fibers is 1 part by mass is improved to 65, It can be seen that the evaluation is further improved by further increasing the content. However, the evaluation is 50 or 45 when the content of cellulose fine fiber is in the range of 3 to 25 parts by mass (Example 5-2 to Example 5-6), and even if the content of cellulose fine fiber is increased, The improvement in wear tends to saturate.

[Embodiment 4]
(Toothed belt B)
FIG. 22 shows a toothed belt B according to the fourth embodiment.

The toothed belt B according to Embodiment 4 includes an endless toothed belt body 310 formed of a rubber composition. The toothed belt main body 310 includes a flat belt-like base portion 311a and a plurality of tooth portions 311b that are integrally provided at a constant pitch at intervals in the belt length direction on one side, that is, the inner peripheral surface. Have. A tooth side reinforcing cloth 312 is attached to the toothed belt main body 310 so as to cover the tooth side surface thereof. A core wire 313 is embedded on the inner peripheral side of the base 311a of the toothed belt main body 310 so as to form a spiral having a pitch in the belt width direction. The toothed belt B according to the fourth embodiment is suitably used as a power transmission member of, for example, a belt transmission device in a machine tool or the like, in particular, a belt transmission device in a machine tool having an operation time of about 3 to 120 hours per year. The toothed belt B according to Embodiment 4 has, for example, a belt length of 500 to 3000 mm, a belt width of 10 to 200 mm, and a belt thickness of 3 to 20 mm. Further, the tooth portion 311b has, for example, a width of 0.63 to 16.46 mm, a height of 0.37 to 9.6 mm, and a pitch of 1.0 to 31.75 mm.

The tooth portion 311b of the toothed belt main body 310 may be a trapezoidal tooth having a trapezoidal shape when viewed from the side, may be a semicircular round tooth, and may have other shapes. Good. The tooth portion 311b may be formed so as to extend in the belt width direction, or may be a helical tooth formed so as to extend in a direction inclined with respect to the belt width direction.

In the toothed belt main body 310, an uncrosslinked rubber composition obtained by mixing and kneading various rubber compounding agents in addition to cellulose fine fibers containing a fiber diameter distribution range of 50 to 500 nm in a rubber component is heated and added. It is formed of a rubber composition that is pressed and crosslinked with a crosslinking agent. As described above, the rubber composition forming the toothed belt body 310 contains the cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm, whereby the durability of the toothed belt B can be improved. . Here, “fine fiber” in the present application means a fiber having a fiber diameter of 1.0 μm or less.

Examples of the rubber component of the rubber composition forming the toothed belt main body 310 include hydrogenated acrylonitrile rubber (H-NBR), hydrogenated acrylonitrile rubber reinforced with unsaturated carboxylic acid metal salt (H-NBR), ethylene, and the like. -Ethylene-α-olefin elastomers such as propylene copolymer (EPR), ethylene-propylene-diene terpolymer (EPDM), ethylene-octene copolymer, ethylene-butene copolymer, chloroprene rubber (CR), and chlorosulfonated polyethylene rubber (CSM) ) And the like. The rubber component of the rubber composition forming the toothed belt main body 310 is preferably a blend rubber of one or more of these.

In H-NBR reinforced with an unsaturated carboxylic acid metal salt, examples of the unsaturated carboxylic acid include methacrylic acid and acrylic acid, and examples of the metal include zinc, calcium, magnesium, aluminum and the like. Is mentioned.

The cellulosic fine fibers preferably have a wide fiber diameter distribution from the viewpoint of improving the durability of the toothed belt B, and the fiber diameter distribution range includes 50 to 500 nm. From the viewpoint, the lower limit of the fiber diameter distribution is preferably 20 nm or less, more preferably 10 nm or less. From the same viewpoint, the upper limit is preferably 700 nm or more, more preferably 1 μm or more. The fiber diameter distribution range of the cellulosic fine fibers preferably includes 20 nm to 700 mm, and more preferably includes 10 nm to 1 μm.

The average fiber diameter of the cellulosic fine fibers contained in the rubber composition forming the toothed belt body 310 is preferably 10 nm or more, more preferably 20 nm or more, and preferably 700 nm or less, more preferably 100 nm or less. It is.

The distribution of the fiber diameter of the cellulosic fine fibers was determined by freeze-grinding a sample of the rubber composition forming the toothed belt main body 310, and then observing the cross section with a transmission electron microscope (TEM). A fine fiber is arbitrarily selected, the fiber diameter is measured, and obtained based on the measurement result. The average fiber diameter of the cellulosic fine fibers is obtained as the number average of the fiber diameters of 50 arbitrarily selected cellulosic fine fibers.

From the viewpoint of improving the durability of the toothed belt B, the content of the cellulosic fine fibers in the rubber composition forming the toothed belt body 310 is preferably 1 part by weight or more with respect to 100 parts by weight of the rubber component. More preferably, it is 3 parts by mass or more, more preferably 5 parts by mass or more, preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and still more preferably 10 parts by mass or less.

Examples of rubber compounding agents include reinforcing materials, processing aids, vulcanization acceleration aids, plasticizers, co-crosslinking agents, crosslinking agents, vulcanization accelerators, anti-aging agents, and the like.

As the reinforcing material, carbon black, for example, channel black; furnace black such as SAF, ISAF, N-339, HAF, N-351, MAF, FEF, SRF, GPF, ECF, N-234; FT, MT, etc. Thermal black; acetylene black and the like. Silica is also mentioned as the reinforcing material. It is preferable that a reinforcing material is 1 type, or 2 or more types among these. The content of the reinforcing material is, for example, 20 to 60 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

Examples of the vulcanization acceleration aid include metal oxides such as zinc oxide (zinc white) and magnesium oxide, metal carbonates, fatty acids and derivatives thereof. Among these, the vulcanization acceleration aid is preferably one or more. The content of the vulcanization acceleration aid is, for example, 3 to 7 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

Examples of the plasticizer include dialkyl phthalates such as dibutyl phthalate (DBP) and dioctyl phthalate (DOP), dialkyl adipates such as dioctyl adipate (DOA), and dialkyl sebacates such as dioctyl sebacate (DOS). It is preferable that a plasticizer is 1 type, or 2 or more types among these. The plasticizer content is, for example, 0.1 to 40 parts by mass with respect to 100 parts by mass of the rubber component.

Examples of the co-crosslinking agent include liquid rubber such as liquid NBR. The co-crosslinking agent is preferably one type or two or more types. The content of the co-crosslinking agent is, for example, 3 to 7 parts by mass with respect to 100 parts by mass of the rubber component.

Examples of the vulcanization accelerator include thiuram (eg, TETD, TT, TRA, etc.), thiazole (eg, MBT, MBTS, etc.), sulfenamide (eg, CZ), dithiocarbamate (eg, BZ-P). Etc.). It is preferable that a vulcanization accelerator is 1 type, or 2 or more types among these. The content of the vulcanization accelerator is, for example, 2 to 5 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

Examples of the anti-aging agent include amine-ketone anti-aging agents, diamine anti-aging agents, phenol anti-aging agents and the like. It is preferable that an anti-aging agent is 1 type, or 2 or more types among these. The content of the anti-aging agent is, for example, 0.1 to 5 parts by mass with respect to 100 parts by mass of the rubber component.

Note that the rubber composition forming the toothed belt main body 310 may contain short fibers having a fiber diameter of 10 μm or more.

The tooth part side reinforcing cloth 312 is made of a cloth material such as a woven fabric, a knitted fabric, or a non-woven fabric formed of yarns such as cotton, polyamide fiber, polyester fiber, and aramid fiber. It is preferable that the tooth part side reinforcing cloth 312 has extensibility. The thickness of the tooth side reinforcing cloth 312 is, for example, 0.3 to 2.0 mm. The tooth part side reinforcing cloth 312 is subjected to an adhesion process for adhesion to the toothed belt main body 310.

The core wire 313 is composed of a twisted yarn formed of glass fiber, aramid fiber, polyamide fiber, polyester fiber or the like. The diameter of the core wire 313 is, for example, 0.5 to 2.5 mm, and the dimension between adjacent core wire centers in the cross section is, for example, 0.05 to 0.20 mm. The core wire 313 is subjected to an adhesive treatment for imparting adhesiveness to the toothed belt main body 310.

According to the toothed belt B according to the fourth embodiment having the above-described configuration, the rubber composition forming the toothed belt main body 310 including the base portion 311a and the tooth portion 311b includes cellulose having a fiber diameter distribution range of 50 to 500 nm. By containing the system fine fiber, its excellent reinforcing effect can be obtained, and in particular, chipping of the tooth portion 311b can be suppressed, and excellent oil resistance can be obtained, and as a result, high durability can be obtained. it can.

(Manufacturing method of toothed belt B)
A method for manufacturing the toothed belt B according to the fourth embodiment will be described with reference to FIGS.

FIG. 23 shows a belt forming die 320 used for manufacturing the toothed belt B according to the fourth embodiment.

The belt forming die 320 has a cylindrical shape, and tooth portion forming grooves 321 extending in the axial direction are formed on the outer peripheral surface thereof at a constant pitch with an interval in the circumferential direction.

The method for manufacturing a toothed belt according to Embodiment 4 includes a material preparation process, a molding process, a crosslinking process, and a finishing process.

<Material preparation process>
-Uncrosslinked rubber sheet 311 'for base and teeth-
First, cellulosic fine fibers are put into a kneaded rubber component and dispersed by kneading.

Here, as a method for dispersing the cellulose-based fine fibers in the rubber component, for example, a dispersion (gel) in which the cellulose-based fine fibers are dispersed in water is added to the rubber component kneaded with an open roll, A method of vaporizing moisture while kneading them, a master of cellulose fine fibers / rubber obtained by mixing a dispersion (gel) in which cellulosic fine fibers are dispersed in water and rubber latex to vaporize the moisture Obtained by mixing the batch into a rubber component that has been masticated, mixing a dispersion in which cellulosic fine fibers are dispersed in a solvent, and a solution in which the rubber component is dissolved in the solvent, and evaporating the solvent. Cellulose fine fiber / rubber masterbatch is put into the kneaded rubber component, dispersion (gel) in which cellulose fine fiber is dispersed in water is freeze-dried and pulverized And what, how to put into a rubber component is masticated, methods and the like to introduce cellulosic microfibers made hydrophobic in rubber component is masticated.

Next, while kneading the rubber component and the cellulosic fine fiber, various rubber compounding agents are added and kneading is continued.

Then, the obtained uncrosslinked rubber composition is formed into a sheet shape by calendar molding or the like to produce an uncrosslinked rubber sheet 311 'for the base and teeth.

-Tooth side reinforcing cloth 312'-
Adhesive treatment is applied to the tooth side reinforcing cloth 312 ′. Specifically, the tooth side reinforcing cloth 312 ′ is subjected to an RFL adhesion treatment in which it is immersed in an RFL aqueous solution and heated. Further, if necessary, a base adhesion treatment in which the substrate is immersed in a base adhesion treatment solution and heated is performed before the RFL adhesion treatment. In addition, if necessary, a soaking rubber paste bonding treatment that is immersed in rubber paste after the RFL bonding treatment and / or drying, and / or a coating rubber paste that is coated with rubber paste on the surface on the toothed belt body 310 side and dried. Apply adhesive treatment.

Next, both ends of the tooth side reinforcing cloth 312 ′ subjected to the adhesion treatment are joined to form a cylindrical shape.

-Core 313'-
An adhesive treatment is applied to the core wire 313 ′. Specifically, the core wire 313 ′ is subjected to an RFL adhesion treatment in which it is immersed in a resorcin / formalin / latex aqueous solution (hereinafter referred to as “RFL aqueous solution”) and heated. In addition, if necessary, a base adhesive treatment in which the substrate is immersed in a base adhesive treatment solution and heated before the RFL adhesive treatment and / or a rubber paste adhesive treatment in which the RFL adhesive treatment is immersed in rubber paste and dried are performed.

<Molding process>
As shown in FIG. 24, a cylindrical tooth portion side reinforcing cloth 312 ′ is placed on the outer periphery of the belt mold 320, and a core wire 313 ′ is wound spirally thereon, and further, an uncrosslinked rubber sheet 311 ′ is formed thereon. Wrap. At this time, a laminated molded body B ′ is formed on the belt mold 320. The uncrosslinked rubber sheet 311 ′ may be used so that the line direction corresponds to the belt length direction, or the line direction may correspond to the belt width direction. .

<Crosslinking process>
As shown in FIG. 25, after the release paper 322 is wound around the outer periphery of the laminated molded body B ′, a rubber sleeve 323 is placed on the outer periphery, and the rubber sleeve 323 is placed and sealed in the vulcanizing can. Is filled with high-temperature and high-pressure steam and held for a predetermined molding time. At this time, the uncrosslinked rubber sheet in the laminated molded body B ′ flows while pressing the tooth portion side reinforcing cloth 312 ′ and flows into the tooth portion forming groove 321 of the belt forming die 320, and the crosslinking proceeds, And the tooth part side reinforcing cloth 312 ′ and the core wire 313 ′ are combined and integrated, and finally, a cylindrical belt slab S is formed as shown in FIG. The molding temperature of the belt slab S is, for example, 100 to 180 ° C., the molding pressure is, for example, 0.5 to 2.0 MPa, and the molding time is, for example, 10 to 60 minutes.

<Finishing process>
The inside of the vulcanizing can is depressurized to release the seal, the belt slab S molded between the belt mold 320 and the rubber sleeve 323 is taken out and demolded, and the back side is polished to adjust the thickness. After that, the toothed belt B is manufactured by cutting into a predetermined width.

[Embodiment 5]
(Toothed belt B)
Since the external configuration of the toothed belt B according to the fifth embodiment is the same as that of the fourth embodiment, a description will be given below based on FIG.

In the toothed belt B according to the fifth embodiment, the rubber composition forming the base 311a in the toothed belt main body 310 contains cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm. On the other hand, the rubber composition forming the tooth portion 311b does not contain such cellulosic fine fibers. The rubber composition forming the tooth portion 311b may contain cellulosic fine fibers whose fiber diameter distribution range does not include 50 to 500 nm.

Other configurations are the same as those in the fourth embodiment.

According to the toothed belt B according to the fifth embodiment having the above-described configuration, the rubber composition forming the base 311a is superior in that it contains cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm. The reinforcing effect can be obtained, and excellent oil resistance can be obtained. As a result, high durability can be obtained.

(Manufacturing method of toothed belt B)
In the manufacturing method of the toothed belt B according to the fifth embodiment, in the material preparation step, as in the fourth embodiment, an uncrosslinked rubber sheet for a base containing cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm is used. 311a ′ is produced. In addition, uncrosslinked rubber containing no cellulosic fine fiber having a fiber diameter distribution range of 50 to 500 nm obtained by blending various rubber compounding agents with a rubber component and kneading with a kneader such as a kneader or Banbury mixer. An uncrosslinked rubber 311 b ′ for a tooth part, in which the composition is formed in the shape of the tooth part forming groove 321 of the belt mold 320, is prepared.

Then, in the molding step, as shown in FIG. 27, the outer periphery of the belt mold 320 is covered with a cylindrical tooth side reinforcing cloth 312 ′ and along the tooth part forming groove 321, then, as shown in FIG. Then, the uncrosslinked rubber 311b ′ for the tooth portion is fitted into each tooth portion forming groove 321, and as shown in FIG. 29, the core wire 313 ′ is spirally wound from above, and the unbridged portion for the base portion is further wound thereon. A laminated molded body B ′ is formed by winding the rubber sheet 311a ′. In the cross-linking step, cross-linking of the uncrosslinked rubber 311b ′ for teeth and the uncrosslinked rubber sheet 311a ′ for base in the laminated molded body B ′ proceeds, and the tooth side reinforcing cloth 312 ′ and the core wire 313 ′. Finally, a cylindrical belt slab S similar to that shown in FIG. 26 in the fourth embodiment is molded.

Other methods are the same as those in the fourth embodiment.

[Embodiment 6]
(Toothed belt B)
Since the external configuration of the toothed belt B according to the sixth embodiment is the same as that of the fourth embodiment, the following description is based on FIG.

In the toothed belt B according to the sixth embodiment, the rubber composition forming the tooth portion 311b in the toothed belt main body 310 contains cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm. On the other hand, the rubber composition forming the base 311a does not contain such cellulosic fine fibers. Note that the rubber composition forming the base 311a may contain cellulosic fine fibers whose fiber diameter distribution range does not include 50 to 500 nm.

Other configurations are the same as those in the fourth embodiment.

According to the toothed belt B according to the sixth embodiment having the above configuration, the rubber composition forming the tooth portion 311b contains cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm. An excellent reinforcing effect can be obtained, in particular, chipping of the tooth portion 311b can be suppressed, and excellent oil resistance can be obtained. As a result, high durability can be obtained.

(Manufacturing method of toothed belt B)
In the manufacturing method of the toothed belt B according to the sixth embodiment, in the material preparation step, as in the fourth embodiment, the uncrosslinked rubber for the tooth portion containing the cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm as in the fourth embodiment The composition is kneaded, and an uncrosslinked rubber 311 b ′ for the tooth portion, which is formed into the shape of the tooth portion forming groove 321 of the belt mold 320, is produced. Further, by blending various rubber compounding agents with the rubber component and kneading with a kneader such as a kneader or a Banbury mixer, the uncrosslinked rubber composition not containing such cellulosic fine fibers is formed into a sheet by calendar molding or the like. An uncrosslinked rubber sheet 311a ′ for the base is formed by molding.

Then, in the molding step, as shown in FIG. 27 in the fifth embodiment, after covering the outer periphery of the belt mold 320 with the cylindrical tooth side reinforcing cloth 312 ′ and along the tooth part forming groove 321, As shown in FIG. 28, uncrosslinked rubber 311b ′ for teeth is inserted into each tooth forming groove 321 and the core wire 313 ′ is spirally wound from above, as shown in FIG. Further, a laminated molded body B ′ is formed by winding an uncrosslinked rubber sheet 311a ′ for the base portion thereon. In the cross-linking step, cross-linking of the uncrosslinked rubber 311b ′ for teeth and the uncrosslinked rubber sheet 311a ′ for base in the laminated molded body B ′ proceeds, and the tooth side reinforcing cloth 312 ′ and the core wire 313 ′. Finally, a cylindrical belt slab S similar to that shown in FIG. 26 in the fourth embodiment is molded.

Other methods are the same as those in the fourth embodiment.

[Embodiment 7]
(Toothed belt B)
Since the external configuration of the toothed belt B according to the seventh embodiment is the same as that of the fourth embodiment, a description will be given below based on FIG.

In the toothed belt B according to the seventh embodiment, the tooth portion side reinforcing cloth 312 is subjected to an RFL adhesion treatment in which it is immersed in an RFL aqueous solution and heated. As a result, the tooth side reinforcing cloth 312 is adhered to the toothed belt main body 310 via the RFL adhesive layer 314 formed by the RFL adhesion process, as shown in FIG. In addition, before the RFL adhesion treatment, a foundation adhesion treatment comprising a solution obtained by dissolving a foundation adhesion treatment agent such as an epoxy resin or an isocyanate resin (block isocyanate) in a solvent such as toluene, or a dispersion liquid dispersed in water. It is preferable that a base adhesion treatment in which the substrate is immersed in a liquid and heated is performed, and a base adhesive layer is provided under the RFL adhesive layer 314. Further, after RFL adhesion treatment, one kind of soaking rubber glue adhesion treatment that is immersed in rubber glue and dried, and coating rubber glue adhesion treatment that coats and drys the rubber glue on the surface on the toothed belt body 310 side Alternatively, two types of rubber glue adhesion treatment may be performed, and a rubber glue adhesion layer may be provided on the RFL adhesion layer 314.

The RFL adhesive layer 314 is formed of a solid content contained in the RFL aqueous solution, and includes a resorcin / formalin resin (RF resin) and a rubber component derived from rubber latex. The RFL adhesive layer 314 contains cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm. The cellulosic fine fibers contained in the RFL adhesive layer 314 have the same configuration as that contained in the toothed belt main body 310 in the fourth embodiment. As described above, the RFL adhesive layer 314 contains a cellulosic fine fiber having a fiber diameter distribution range of 50 to 500 nm, thereby obtaining a high adhesive force of the tooth side reinforcing fabric 312 to the toothed belt body 310. Can do.

In the RFL adhesive layer 314, the cellulosic fine fibers are not oriented in a specific direction and are not oriented.

The content of the cellulosic fine fibers in the RFL adhesive layer 314 is preferably 0.5% by mass or more, more preferably 1.% from the viewpoint of obtaining high adhesion of the tooth side reinforcing fabric 312 to the toothed belt body 310. It is 0 mass% or more, More preferably, it is 2.0 mass% or more, Preferably it is 12 mass% or less, More preferably, it is 10 mass% or less, More preferably, it is 8 mass% or less.

The content of the cellulosic fine fibers with respect to 100 parts by mass of the rubber component in the RFL adhesive layer 314 is preferably 1 part by mass or more from the viewpoint of obtaining high adhesion to the toothed belt body 310 of the tooth side reinforcing cloth 312. Preferably it is 3 mass parts or more, More preferably, it is 5 mass parts or more, Preferably it is 30 mass parts or less, More preferably, it is 20 mass parts or less, More preferably, it is 10 mass parts or less.

The RFL adhesive layer 314 preferably does not contain short fibers having a fiber diameter of 10 μm or more. However, the RFL adhesive layer 314 is short as long as the adhesiveness of the tooth portion side reinforcing cloth 312 to the toothed belt main body 310 is not hindered. Fibers may be included.

Note that the rubber composition forming the base 311a of the toothed belt main body 310 may contain cellulosic fine fibers as in the fourth and fifth embodiments, and may not contain cellulosic fine fibers. Or either. The rubber composition forming the tooth portion 311b of the toothed belt main body 310 may contain cellulosic fine fibers as in the fourth and sixth embodiments, and may not contain cellulosic fine fibers. Or either.

Other configurations are the same as those in the fourth embodiment.

According to the toothed belt B according to the seventh embodiment configured as described above, the RFL adhesive layer 314 provided between the tooth portion side reinforcing cloth 312 and the toothed belt body 310 has a fiber diameter distribution range of 50 to 50. By containing the cellulosic fine fibers containing 500 nm, it is possible to obtain a high adhesive force of the tooth side reinforcing cloth 312 to the toothed belt main body 310, so that an excellent reinforcing effect is obtained. The chipping of the portion 311b is suppressed, and as a result, high durability can be obtained.

(Manufacturing method of toothed belt B)
In the manufacturing method of the toothed belt B according to the seventh embodiment, in the material preparation process, when the tooth portion side reinforcing cloth 312 ′ is manufactured, the tooth portion side reinforcing cloth 312 ′ is bonded. Specifically, an RFL adhesion treatment is performed on the tooth portion side reinforcing cloth 312 ′ by immersing it in an RFL aqueous solution and heating it. Moreover, it is preferable to perform the foundation | substrate adhesion | attachment process which immerses in a foundation | substrate adhesion | attachment processing liquid and heats before RFL adhesion | attachment processing. In addition, after RFL adhesion treatment, one type of soaking rubber glue adhesion treatment that is dipped in rubber glue and dried, and coating rubber glue adhesion treatment that coats and drys the rubber glue on the surface on the toothed belt body 310 side or Two types of rubber paste adhesion treatment may be performed.

《Base adhesion processing》
The base adhesion treatment liquid is, for example, a solution obtained by dissolving a base adhesion treatment agent such as epoxy resin or isocyanate resin (block isocyanate) in a solvent such as toluene, or a dispersion liquid dispersed in water. The temperature of the base adhesion treatment liquid is, for example, 20 to 30 ° C. The solid content concentration of the base adhesion treatment liquid is preferably 20% by mass or less.

The immersion time in the base adhesive treatment solution is, for example, 1 to 3 seconds. The heating temperature (furnace temperature) after immersion in the base adhesion treatment liquid is, for example, 200 to 250 ° C. The heating time (residence time in the furnace) is, for example, 1 to 3 minutes. The number of times of base adhesion treatment may be only once or may be two or more. The base adhesive treating agent adheres to the tooth side reinforcing cloth 312 ′, and the amount of attachment (weight per unit area) is, for example, 0.5 to 8 based on the mass of the fiber material forming the tooth side reinforcing cloth 312 ′. % By mass.

<< RFL adhesion treatment >>
The RFL aqueous solution is an aqueous solution in which a dispersion (gel) in which cellulosic fine fibers are dispersed in water together with a rubber latex is mixed with an initial condensate of resorcin and formaldehyde. The liquid temperature of the RFL aqueous solution is, for example, 20 to 30 ° C.

The molar ratio of resorcin (R) to formalin (F) is, for example, R / F = 1/1 to 1/2. Examples of the rubber latex include vinylpyridine / styrene / butadiene rubber latex (Vp / St / SBR), chloroprene rubber latex (CR), chlorosulfonated polyethylene rubber latex (CSM), and the like. The solid content mass ratio of the initial condensate (RF) of resorcinol and formaldehyde and the rubber latex (L) is, for example, RF / L = 1/5 to 1/20.

The solid content concentration of the RFL aqueous solution is preferably 6.0% by mass or more, more preferably 9.0% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less.

The immersion time in the RFL aqueous solution is, for example, 1 to 3 seconds. The heating temperature (furnace temperature) after immersion in the RFL aqueous solution is, for example, 100 to 180. The heating time (residence time in the furnace) is, for example, 1 to 5 minutes. The number of RFL adhesion treatments may be only once, or may be two or more. The RFL adhesive layer 314 is attached to the tooth side reinforcing cloth 312 ′, and the attached amount (weight per unit area) is, for example, 2 to 5% by mass based on the mass of the fiber material forming the tooth side reinforcing cloth 312 ′. It is.

Other methods are the same as those in the fourth embodiment.

[Embodiment 8]
Since the external configuration of the toothed belt B according to the eighth embodiment is the same as that of the fourth embodiment, the following description is based on FIG.

In the toothed belt B according to the eighth embodiment, an RFL bonding treatment in which the tooth portion side reinforcing cloth 312 is immersed in an RFL aqueous solution and heated, a soaking rubber paste bonding treatment in which the toothed belt B is dipped in rubber paste and dried, and a toothed belt. One or two types of rubber glue adhesion treatment is applied among the coating rubber glue adhesion treatments in which the surface on the main body 310 side is coated with rubber glue and dried. Thereby, as shown in FIG. 31, the tooth part side reinforcing cloth 312 has a toothed belt main body via the RFL adhesive layer 314 formed by the RFL adhesive treatment and the rubber glue adhesive layer 315 formed by the rubber glue adhesive treatment. Bonded to 310. In addition, before the RFL adhesion treatment, a foundation adhesion treatment comprising a solution obtained by dissolving a foundation adhesion treatment agent such as an epoxy resin or an isocyanate resin (block isocyanate) in a solvent such as toluene, or a dispersion liquid dispersed in water. It is preferable that a base adhesion treatment in which the substrate is immersed in a liquid and heated is performed, and a base adhesive layer is provided under the RFL adhesive layer 314.

The RFL adhesive layer 314 may contain cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm as in the fourth embodiment, or may not contain such cellulosic fine fibers. But you can.

The rubber paste adhesive layer 315 is formed of a solid rubber composition contained in the rubber paste, and the rubber composition forming the rubber paste adhesive layer 315 has a fiber diameter distribution range of 50 in the rubber component. An uncrosslinked rubber composition in which various rubber compounding agents are blended and kneaded in addition to cellulose fine fibers containing ˜500 nm is heated and pressurized and crosslinked with a crosslinking agent. As described above, since the rubber paste adhesive layer 315 contains the cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm, the adhesive strength of the tooth side reinforcing cloth 312 to the toothed belt body 310 is high. Can be obtained.

Examples of the rubber component of the rubber composition forming the rubber paste adhesive layer 315 include hydrogenated acrylonitrile rubber (H-NBR), hydrogenated acrylonitrile rubber reinforced with unsaturated carboxylic acid metal salt (H-NBR), ethylene, and the like. -Ethylene-α-olefin elastomers such as propylene copolymer (EPR), ethylene-propylene-diene terpolymer (EPDM), ethylene-octene copolymer, ethylene-butene copolymer, chloroprene rubber (CR), and chlorosulfonated polyethylene rubber (CSM) ) And the like. The rubber component of the rubber composition forming the toothed belt main body 310 is preferably a blend rubber of one or more of these. The rubber component of the rubber composition forming the rubber paste adhesive layer 315 may be the same as or different from the rubber component of the rubber composition forming the toothed belt main body 310.

The cellulosic fine fibers contained in the rubber composition forming the rubber paste adhesive layer 315 have the same configuration as that contained in the toothed belt body 310 in the fourth embodiment. In the rubber paste adhesive layer 315, the cellulosic fine fibers are not oriented in a specific direction and are not oriented.

The content of the cellulosic fine fibers in the rubber paste adhesive layer 315 is preferably 1 mass with respect to 100 parts by mass of the rubber component from the viewpoint of obtaining high adhesion of the tooth side reinforcing fabric 312 to the toothed belt body 310. Part or more, more preferably 3 parts by weight or more, still more preferably 5 parts by weight or more, and preferably 30 parts by weight or less, more preferably 20 parts by weight or less, still more preferably 10 parts by weight or less.

Examples of rubber compounding agents include reinforcing materials, friction coefficient reducing materials, cross-linking agents, and anti-aging agents.

As the reinforcing material, carbon black, for example, channel black; furnace black such as SAF, ISAF, N-339, HAF, N-351, MAF, FEF, SRF, GPF, ECF, N-234; FT, MT, etc. Thermal black; acetylene black and the like. Silica is also mentioned as the reinforcing material. It is preferable that a reinforcing material is 1 type, or 2 or more types among these. The content of the reinforcing material is preferably smaller than the content of the reinforcing material in the rubber composition forming the toothed belt body 310, and is, for example, 10 to 30 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition. is there.

Examples of the friction coefficient reducing material include ultra high molecular weight polyethylene resin powder, fluororesin powder, and molybdenum. The friction coefficient reducing material is preferably one or more of these. The content of the friction coefficient reducing material is, for example, 5 to 15 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

Examples of the crosslinking agent include sulfur and organic peroxides. As a crosslinking agent, sulfur may be blended, an organic peroxide may be blended, or both of them may be used in combination. The compounding amount of the crosslinking agent is, for example, 0.3 to 5 parts by mass in the case of sulfur with respect to 100 parts by mass of the rubber component of the rubber composition, and 100 parts by mass of the rubber component of the rubber composition in the case of the organic peroxide. For example, it is 0.3 to 5 parts by mass.

Examples of the anti-aging agent include amine-ketone anti-aging agents, diamine anti-aging agents, phenol anti-aging agents and the like. It is preferable that an anti-aging agent is 1 type, or 2 or more types among these. The content of the anti-aging agent is, for example, 1 to 3 parts by mass with respect to 100 parts by mass of the rubber component.

The rubber composition forming the rubber paste adhesive layer 315 preferably does not contain short fibers having a fiber diameter of 10 μm or more. However, the adhesiveness of the tooth side reinforcing cloth 312 to the toothed belt body 310 is not preferred. Such short fibers may be included as long as they do not hinder.

According to the toothed belt B according to the eighth embodiment configured as described above, the rubber glue adhesive layer 315 provided between the tooth portion side reinforcing cloth 312 and the toothed belt main body 310 has a fiber diameter distribution range of 50. By containing cellulosic fine fibers containing ˜500 nm, it is possible to obtain a high adhesive force to the toothed belt body 310 of the tooth portion side reinforcing cloth 312, so that an excellent reinforcing effect is obtained. The chipping of the tooth portion 311b is suppressed, and excellent oil resistance can be obtained. Furthermore, since the rubber paste adhesive layer 315 contains cellulosic fine fibers having a fiber diameter distribution range of 50 to 500 nm, it is possible to obtain high wear resistance on the tooth side surface. As a result, high durability can be obtained.

(Manufacturing method of toothed belt B)
In the manufacturing method of the toothed belt B according to the eighth embodiment, in the material preparation process, when the tooth part side reinforcing cloth 312 ′ is manufactured, the tooth part side reinforcing cloth 312 ′ is bonded. Specifically, in addition to the RFL adhesion treatment in which the tooth portion side reinforcing cloth 312 ′ is immersed and heated in the RFL aqueous solution, the soaking rubber glue adhesion treatment in which the tooth side reinforcement cloth 312 ′ is immersed in the rubber glue and dried, and the toothed belt body One or two types of rubber glue adhesion treatment is performed among the coating rubber glue adhesion treatments in which the surface on the 310 side is coated with rubber glue and dried. In addition, it is preferable to perform the foundation | substrate adhesion | attachment process which is immersed in a foundation | substrate adhesion | attachment processing liquid and heated before RFL adhesion | attachment processing.

The base adhesion process is the same as that of the seventh embodiment.

<< RFL adhesion treatment >>
The RFL aqueous solution is an aqueous solution in which a rubber latex is mixed with an initial condensate of resorcin and formaldehyde. In addition, when including a cellulose fine fiber in RFL contact bonding layer 314, the dispersion (gel) which disperse | distributed the cellulose fine fiber in water similarly to Embodiment 7 should just be included. The liquid temperature of the RFL aqueous solution is, for example, 20 to 30 ° C. The solid content concentration of the RFL aqueous solution is preferably 30% by mass or less.

The immersion time in the RFL aqueous solution is, for example, 1 to 3 seconds. The heating temperature (furnace temperature) after immersion in the RFL aqueous solution is, for example, 100 to 180 ° C. The heating time (residence time in the furnace) is, for example, 1 to 5 minutes. The number of RFL adhesion treatments may be only once, or may be two or more. The RFL adhesive layer 314 is attached to the tooth side reinforcing cloth 312 ′, and the attached amount (weight per unit area) is, for example, 2 to 5% by mass based on the mass of the fiber material forming the tooth side reinforcing cloth 312 ′. It is.

<Rubber glue adhesion treatment>
The rubber paste is a solution in which an uncrosslinked rubber composition before crosslinking of a rubber composition containing cellulosic fine fibers forming the rubber paste adhesive layer 315 is dissolved in a solvent such as toluene. The rubber paste is produced as follows.

Here, as a method for dispersing the cellulose-based fine fibers in the rubber component, for example, a dispersion (gel) in which the cellulose-based fine fibers are dispersed in water is added to the rubber component kneaded with an open roll, A method of vaporizing moisture while kneading them, a master of cellulose fine fibers / rubber obtained by mixing a dispersion (gel) in which cellulosic fine fibers are dispersed in water and rubber latex to vaporize the moisture A method in which a batch is put into a kneaded rubber component, a dispersion in which hydrophobic cellulose fine fibers are dispersed in a solvent, and a solution in which the rubber component is dissolved in a solvent are mixed and the solvent is evaporated. Of the obtained cellulose-based fine fiber / rubber masterbatch into the kneaded rubber component, and a dispersion (gel) in which the cellulose-based fine fiber is dispersed in water is freeze-dried A material obtained by pulverizing Te, how to put into a rubber component is masticated, methods and the like to introduce cellulosic microfibers made hydrophobic in rubber component is masticated.

Then, the uncrosslinked rubber composition is put into a solvent and stirred until a uniform solution is obtained, thereby producing a rubber paste. The temperature of the rubber paste is, for example, 20 to 30 ° C.

The solid content concentration of the rubber paste is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, for soaking rubber paste adhesion treatment. is there. For coating rubber paste adhesion treatment, it is preferably 10% by mass or more, more preferably 20% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less.

In the case of soaking rubber glue bonding treatment, the immersion time in the rubber glue is, for example, 1 to 3 seconds. The drying temperature (furnace temperature) after immersion in rubber paste is, for example, 50 to 100 ° C. The drying time (residence time in the furnace) is, for example, 1 to 3 minutes. The number of times of the soaking rubber paste adhesion treatment may be only once, or may be two or more times. A rubber glue adhesive layer 315 is attached to the tooth side reinforcing cloth 312 ′. The amount of attachment (weight per unit area) is, for example, 2 to 5 mass based on the mass of the fiber material forming the tooth side reinforcing cloth 312 ′. %.

In the case of coating rubber paste adhesion treatment, the drying temperature (furnace temperature) after coating is, for example, 50 to 100 ° C. The drying time (residence time in the furnace) is, for example, 1 to 3 minutes. The number of times of coating rubber paste adhesion treatment may be only once or may be two or more times. A rubber glue adhesive layer 315 is attached to the tooth side reinforcing cloth 312 ′. The amount of attachment (weight per unit area) is, for example, 2 to 5 mass based on the mass of the fiber material forming the tooth side reinforcing cloth 312 ′. %.

Other methods are the same as those in the fourth embodiment.

-Example-
(Uncrosslinked rubber composition)
The following rubbers 1 to 7 of an uncrosslinked rubber composition for forming a toothed belt body and rubbers 8 to 14 of an uncrosslinked rubber composition for a rubber paste adhesive layer of a tooth side reinforcing fabric were prepared. Each formulation is also shown in Table 6 and Table 7.

<Rubber 1>
First, a dispersion in which powdered cellulose (trade name: KC Flock W-GK manufactured by Nippon Paper Industries Co., Ltd.) is dispersed in toluene is prepared, and the dispersion is collided with a high-pressure homogenizer to convert the powdered cellulose into cellulose fine fibers. The fiber was defibrated to obtain a dispersion in which cellulose fine fibers were dispersed in toluene. Accordingly, the cellulose fine fibers are produced by mechanical defibrating means and are not subjected to a hydrophobic treatment.

Next, the dispersion in which fine cellulose fibers are dispersed in toluene, and H-NBR (trade name: Zetpol 2020 manufactured by Nippon Zeon Co., Ltd.) are dissolved in toluene and a plasticizer (trade name: W-260 manufactured by DIC) is added. The resultant solution was mixed, and toluene and a plasticizer were vaporized to prepare a master batch of cellulose fine fiber / H-NBR. The content of each component in the master batch was 25% by mass for the cellulosic fine fibers, 25% by mass for the plasticizer, and 50% by mass for H-NBR.

Subsequently, H-NBR was masticated and a master batch was added thereto for kneading. The mixing mass ratio of H-NBR and masterbatch was 98: 4, and the content of fine cellulose fibers was 1 part by mass when the total H-NBR was 100 parts by mass.

Then, H-NBR, cellulose fine fiber, and plasticizer are kneaded, and 40 parts by mass of reinforcing material FEF carbon black (trade name: Seast SO manufactured by Tokai Carbon Co., Ltd.) is added to 100 parts by mass of H-NBR. 1 part by weight of processing aid stearic acid (trade name: Tsubaki stearic acid manufactured by NOF Corporation) and 5 parts by weight of zinc oxide (trade name: Zinc Oxide made by Sakai Chemical Industry Co., Ltd.) , 24 parts by mass of plasticizer, 5 parts by mass of liquid NBR (trade name: Nipol 1312 manufactured by Nippon Zeon Co., Ltd.) as a co-crosslinking agent, and 0% of sulfur (trade name: Oil Sulfur manufactured by Nippon Kibuki Kogyo Co., Ltd.) as a crosslinking agent. 5 parts by mass, 2 parts by mass of a thiuram vulcanization accelerator (Ouchi Shinsei Chemical Co., Ltd., trade name: Noxeller TET-G), and an amine-ketone antioxidant (manufactured by Ouchi Shinsei Co., Ltd., trade name: Nocrack 224) To prepare uncrosslinked rubber composition by parts by weight respectively turned to continue the kneading. The uncrosslinked rubber composition was designated as rubber 1. The content of the plasticizer in the rubber 1 is 25 parts by mass with respect to 100 parts by mass of H-NBR, including those contained in the master batch and those added later.

<Rubber 2>
Rubber 2 was an uncrosslinked rubber composition prepared in the same manner as rubber 1 except that the content of fine cellulose fibers was 3 parts by mass with respect to 100 parts by mass of H-NBR.

<Rubber 3>
Rubber 3 was an uncrosslinked rubber composition produced in the same manner as rubber 1 except that the content of cellulose fine fibers was 5 parts by mass with respect to 100 parts by mass of H-NBR.

<Rubber 4>
Rubber 4 was an uncrosslinked rubber composition prepared in the same manner as rubber 1 except that the content of cellulose fine fibers was 10 parts by mass with respect to 100 parts by mass of H-NBR.

<Rubber 5>
Rubber 5 was an uncrosslinked rubber composition produced in the same manner as rubber 1 except that the content of fine cellulose fibers was 15 parts by mass with respect to 100 parts by mass of H-NBR.

<Rubber 6>
Rubber 6 was an uncrosslinked rubber composition produced in the same manner as rubber 1 except that the content of cellulose fine fibers was 25 parts by mass with respect to 100 parts by mass of H-NBR.

<Rubber 7>
While masticating H-NBR, 40 parts by mass of FEF carbon black as a reinforcing material, 1 part by mass of stearic acid as a processing aid, and zinc oxide as a vulcanization accelerating agent are added to 100 parts by mass of H-NBR. 5 parts by weight, plasticizer 10 parts by weight, co-crosslinking agent liquid NBR 5 parts by weight, crosslinking agent sulfur 0.5 parts by weight, thiuram vulcanization accelerator 2 parts by weight, and amine-ketone system An uncrosslinked rubber composition was prepared by charging and kneading 2 parts by weight of each anti-aging agent. The uncrosslinked rubber composition was designated as rubber 7. Therefore, the rubber 7 does not contain cellulose fine fibers.

<Rubber 8>
Zinc methacrylate reinforced H-NBR (trade name: Zeoforte ZSC 2295, manufactured by Nippon Zeon Co., Ltd.) and H-NBR (trade name: Zetpole 2020, manufactured by Nippon Zeon Co., Ltd.) were kneaded with a mixing mass ratio of the former and the latter of 50:50. At the same time, 20 parts by mass of reinforcing material FEF carbon black (trade name: Seast SO manufactured by Tokai Carbon Co., Ltd.) and 100% by mass of these rubber components, ultrahigh molecular weight polyethylene powder (Mitsui) 10 parts by mass of trade name: Mipperon XM-220 manufactured by Kagaku Co., Ltd., 0.5 parts by mass of sulfur as a crosslinking agent (trade name: Oil Sulfur manufactured by Nippon Kibushi Kogyo Co., Ltd.), thiuram vulcanization accelerator (Ouchi Shinsei Chemical) 2 parts by mass of the product, product name: Noxeller TET-G), and 2 parts by mass of the amine-ketone anti-aging agent (trade name: Nocrack 224, manufactured by Ouchi Shinsei Co., Ltd.) And kneading to prepare an uncrosslinked rubber composition. The uncrosslinked rubber composition was designated as rubber 8. Accordingly, the rubber 8 does not contain cellulose fine fibers.

<Rubber 9>
Zinc methacrylate reinforced H-NBR and H-NBR were masticated, and a master batch was added thereto and kneaded. The content of cellulose fine fiber is 1 part by mass when the mixing mass ratio of zinc methacrylate reinforced H-NBR, H-NBR, and masterbatch is 50: 48: 4 and the total H-NBR is 100 parts by mass. It was made to become.

Then, zinc methacrylate reinforced H-NBR, H-NBR, fine cellulose fiber, and plasticizer are kneaded and reinforced with respect to 100 parts by mass of the zinc methacrylate reinforced H-NBR and H-NBR rubber components. 20 parts by mass of FEF carbon black as a material, 10 parts by mass of ultra high molecular weight polyethylene powder, 0.5 parts by mass of sulfur as a crosslinking agent, 2 parts by mass of a thiuram vulcanization accelerator, and an amine-ketone aging inhibitor 2 parts by mass of each was added and kneaded to prepare an uncrosslinked rubber composition. The uncrosslinked rubber composition was designated as rubber 9.

<Rubber 10>
The rubber 10 was an uncrosslinked rubber composition prepared in the same manner as the rubber 9 except that the cellulose fine fiber content was 3 parts by mass with respect to 100 parts by mass of the rubber component.

<Rubber 311>
The rubber 311 was an uncrosslinked rubber composition prepared in the same manner as the rubber 9 except that the cellulose fine fiber content was 5 parts by mass with respect to 100 parts by mass of the rubber component.

<Rubber 12>
Rubber 12 was an uncrosslinked rubber composition prepared in the same manner as rubber 9 except that the content of fine cellulose fibers was 10 parts by mass with respect to 100 parts by mass of the rubber component.

<Rubber 13>
Rubber 13 was an uncrosslinked rubber composition prepared in the same manner as rubber 9 except that the content of cellulose fine fibers was 15 parts by mass with respect to 100 parts by mass of the rubber component.

<Rubber 14>
The rubber 14 was an uncrosslinked rubber composition prepared in the same manner as the rubber 9 except that the content of the cellulose fine fiber was 25 parts by mass with respect to 100 parts by mass of the rubber component.

(Toothed belt for prototype evaluation)
The following test evaluation toothed belts (tooth pitch 8 mm and belt width 10 mm) of Examples 6-1 to 6-13 and Comparative Example 6 were produced. Each configuration is also shown in Table 8.

<Example 6-1>
For the toothed belt of Example 6-1, rubber 1 containing fine cellulose fibers was used as the uncrosslinked rubber composition forming the toothed belt body.

As the tooth side reinforcing fabric, a woven fabric was used in which a covering yarn obtained by wrapping an aramid fiber (trade name: Technora, manufactured by Teijin Ltd.) around a urethane yarn to give elasticity was used as a weft and a nylon twisted warp. The woven fabric of the tooth side reinforcing fabric was subjected to a base adhesion treatment that was heated after being immersed in an epoxy resin solution as a base adhesion treatment, and an RFL adhesion treatment that was heated after being immersed in an RFL aqueous solution. In addition, the soaking rubber paste bonding treatment in which the woven fabric of the tooth side reinforcing fabric subjected to the RFL bonding treatment was dipped in rubber paste and dried was repeatedly applied. As the rubber paste, a rubber paste having a solid content concentration of 10% by mass obtained by dissolving rubber 8 containing no cellulose fine fibers in toluene as a solvent was used. The liquid temperature of the rubber paste was 25 ° C. The immersion time in the rubber paste was 5 seconds. The drying temperature after immersion in rubber paste was 100 ° C. and the drying time was 40 seconds.

Glass fiber was used as the core wire.

<Example 6-2>
A toothed belt of Example 6-2 was produced in the same manner as Example 6-1 except that rubber 2 containing cellulose fine fibers was used as the uncrosslinked rubber composition forming the toothed belt body.

<Example 6-3>
A toothed belt of Example 6-3 was prepared in the same manner as Example 6-1 except that rubber 3 containing fine cellulose fibers was used as the uncrosslinked rubber composition forming the toothed belt body.

<Example 6-4>
A toothed belt of Example 6-4 was produced in the same manner as Example 6-1 except that rubber 4 containing fine cellulose fibers was used as the uncrosslinked rubber composition forming the toothed belt body.

<Example 6-5>
A toothed belt of Example 6-5 was prepared in the same manner as Example 6-4 except that rubber paste of rubber 9 containing cellulose fine fibers was used for the soaking rubber paste adhesion treatment of the tooth side reinforcing fabric. .

<Example 6-6>
A toothed belt of Example 6-6 was produced in the same manner as Example 6-4 except that rubber paste of rubber 10 containing cellulose fine fibers was used for the soaking rubber paste bonding treatment of the tooth side reinforcing fabric. .

<Example 6-7>
A toothed belt of Example 6-7 was prepared in the same manner as in Example 6-4 except that rubber paste of rubber 311 containing cellulose fine fiber was used for the soaking rubber paste bonding treatment of the tooth side reinforcing fabric. .

<Example 6-8>
A toothed belt of Example 6-8 was produced in the same manner as in Example 6-4 except that the rubber paste of rubber 12 containing cellulose fine fiber was used for the soaking rubber paste bonding treatment of the tooth side reinforcing fabric. .

<Example 6-9>
A toothed belt of Example 6-9 was produced in the same manner as Example 6-4 except that rubber paste of rubber 13 containing fine cellulose fibers was used for the soaking rubber paste bonding treatment of the tooth side reinforcing fabric. .

<Example 6-10>
A toothed belt of Example 6-10 was produced in the same manner as in Example 6-4, except that rubber paste of rubber 14 containing cellulose fine fibers was used for the soaking rubber paste adhesion treatment of the tooth side reinforcing fabric. .

<Example 6-11>
A toothed belt of Example 6-11 was prepared in the same manner as Example 6-1 except that rubber 5 containing fine cellulose fibers was used as the uncrosslinked rubber composition forming the toothed belt body.

<Example 6-12>
A toothed belt of Example 6-12 was produced in the same manner as Example 6-1 except that rubber 6 containing fine cellulose fibers was used as the uncrosslinked rubber composition forming the toothed belt body.

<Example 6-13>
As the uncrosslinked rubber composition forming the toothed belt body, rubber 7 containing no cellulose fine fibers is used, and the rubber paste of rubber 12 containing cellulose fine fibers is used for the soaking rubber paste bonding treatment of the tooth side reinforcing fabric. A toothed belt of Example 6-13 was produced in the same manner as in Example 6-1, except that this was the case.

<Comparative Example 6>
As a non-crosslinked rubber composition for forming a toothed belt body, rubber 7 containing no cellulose fine fibers is used, and rubber glue of rubber 8 containing no cellulose fine fibers is used for the soaking rubber paste bonding treatment of the tooth side reinforcing fabric. A toothed belt of Comparative Example 6 was produced in the same manner as in Example 6-1 except that this was the case.

(Test evaluation method)
<Average fiber diameter and fiber diameter distribution of cellulose fine fiber>
Samples of a rubber composition in which rubbers 1 to 6 and rubbers 9 to 14 are cross-linked are collected from the toothed belt body and the rubber paste adhesive layer of the toothed belts of Examples 6-1 to 6-13. After freezing and pulverizing a sample of the rubber composition, the cross section thereof is observed with a scanning electron microscope (SEM), 50 fibers are arbitrarily selected, the fiber diameter is measured, the number average is obtained, and the average fiber is obtained. The diameter. Moreover, the maximum value and minimum value of the fiber diameter were calculated | required among 50 cellulose fine fibers.

<Belt running test>
FIG. 32 shows a pulley layout of the belt running test machine 330.

The belt running test machine 330 includes a driving pulley 331, a driven pulley 332, and an idler pulley 333. The drive pulley 331 is provided with 21 tooth-engagement grooves on the pulley periphery. The driven pulley 332 is provided with 42 tooth-engagement grooves on the periphery of the pulley. The idler pulley 333 has a flat pulley periphery for pressing the back surface of the belt. The drive pulley 331, the driven pulley 332, and the idler pulley 333 are all made of carbon steel (S45C).

For each toothed belt B of Example 6-1 to Example 6-13 and Comparative Example 6, this belt running tester 330 was used to evaluate the chipping resistance and wear resistance as follows.

-Tooth chipping resistance evaluation-
The mass of the toothed belt B was measured in advance. Thereafter, the toothed belt B was wound around the belt running tester 330, a load was applied to the driven pulley 332 in the rearward direction, and a tension of 216N was applied to the toothed belt B. Then, the tension applied to the toothed belt B is set to 550 N, the driving pulley 331 is rotated at a rotational speed of 3000 rpm, the belt travels, and the travel time until the tooth part is lost is the tooth endurance life. It was. The belt running test was performed for all of Examples 6-1 to 6-13 and Comparative Example 6 in a room temperature atmosphere, and Examples 6-1 to 6-4, Example 6-11, and Example 6 were performed. For -12 and Comparative Example 6, it was also performed in an 80 ° C. atmosphere.

-Wear resistance evaluation-
The toothed belt B was run for 300 hours under the same conditions as in the measurement of wear resistance. After running the belt, the mass of the toothed belt B was measured again, and the mass difference before and after running was calculated as the wear mass.

<Oil resistance test>
The toothed belts of Examples 6-1 to 6-13 and Comparative Example 6 were each measured for mass and then immersed in new engine oil at 140 ° C. for 168 hours. Thereafter, the adhered oil was sufficiently removed with an air gun, and the mass was measured again. The rate of change in mass before and after immersion (expressed in%) was calculated.

(Test evaluation results)
The test results are shown in Table 9 and Table 10. Hereinafter, the content of the cellulose fine fiber means a part by mass with respect to 100 parts by mass of the rubber component even if not particularly described.

<Average fiber diameter and fiber diameter distribution of cellulose fine fiber>
According to Table 10, it can be seen that the cellulose fine fibers contained in the rubber composition obtained by crosslinking the rubbers 1 to 6 and the rubbers 9 to 14 all have a wide fiber diameter distribution.

<Belt running test>
-Tooth chip resistance (room temperature)-
In Comparative Example 6 in which neither the toothed belt body nor the rubber paste adhesive layer contained cellulose fine fibers, the tooth part durable life at room temperature was 384 hours.

On the other hand, cellulose fine fibers are contained only in the toothed belt body, and the contents thereof are 0 parts by weight, 1 part by weight, 3 parts by weight, 5 parts by weight, 10 parts by weight, and 15 parts by weight, respectively. In Examples 6-1 to 6-4 and Examples 6-11 to 6-12 having 25 parts by mass, the tooth endurance life at room temperature was 528 hours, 696 hours, time 792, 864 hours, in order, 936 hours and 1056 hours. That is, in the range of the present Example, it turns out that tooth | gear part durable life becomes long as content of a cellulose fine fiber increases.

In Examples 6-4 to 6-10, in which the content of cellulose fine fibers in the toothed belt body is the same 10 parts by mass, as the content of cellulose fine fibers in the rubber glue adhesive layer increases, It can be seen that the endurance life of the tooth is long. Specifically, the cellulose fine fiber content in the rubber paste adhesive layers in Examples 6-4 to 6-10 is 0 parts by weight, 1 part by weight, 3 parts by weight, 5 parts by weight, and 10 parts by weight, respectively. , 15 parts by weight, and 25 parts by weight, while the tooth endurance life at room temperature was 864 hours, 912 hours, 960 hours, 1032 hours, 1080 hours, 1128 hours, and 1128 hours, respectively. In Examples 6-9 and 6-10, since the tooth endurance life is the same, when the content of the fine cellulose fibers is 15 parts by mass or more, the effect of increasing the tooth endurance is saturated. Possible possibility.

Further, in Example 6-13 in which only 10 parts by mass of cellulose fine fiber was contained only in the rubber glue adhesive layer, the durable life of the tooth portion was 456 hours, which is slightly longer than that of 384 hours in Comparative Example 6. However, in Example 6-8 in which the content of cellulose fine fibers in the toothed belt body is 10 parts by mass, the content of cellulose fine fibers in the rubber paste adhesive layer is the same as in Example 6-13. It can be seen that the tooth endurance life is significantly excellent at 1080 hours.

From the above, although the durable life of the tooth portion is improved when cellulose fine fibers are contained in any of the toothed belt body and the rubber paste adhesive layer, the effect is more remarkable when it is contained in the toothed belt body. I understand that.

-Tooth chip resistance (80 ° C)-
In Comparative Example 6 in which neither the toothed belt body nor the rubber paste adhesive layer contained cellulose fine fibers, the tooth part durable life at 80 ° C. was 240 hours.

On the other hand, cellulose fine fibers are contained only in the toothed belt body, and the contents thereof are 0 parts by weight, 1 part by weight, 3 parts by weight, 5 parts by weight, 10 parts by weight, and 15 parts by weight, respectively. In Examples 6-1 to 6-4 and Examples 6-11 to 6-12 having 25 parts by mass, the tooth endurance life at 80 ° C. was 432 hours, 624 hours, 744 hours, and 792 hours, respectively. 888 hours, and 9126 hours. That is, in the range of the present Example, it turns out that the tooth | gear durable life at high temperature becomes long as content of a cellulose fine fiber increases.

Further, the tooth endurance life at high temperature (80 ° C.) is shorter than the tooth endurance life at room temperature. However, it turns out that the deterioration is reduced by containing the cellulose fine fiber. That is, in Comparative Example 6, the tooth endurance life at room temperature was 384 hours, whereas the tooth endurance life at 80 ° C. was 240 hours, which was deteriorated by about 38%. On the other hand, in Example 6-1 in which 1 part by mass of cellulose fine fiber was contained in the toothed belt body, the tooth part durable life at room temperature was 528 hours, whereas the tooth part durable life at 80 ° C. Is 432 hours, and the deterioration is about 18%. Also in Example 6-2, Example 6-3, Example 6-4, Example 6-11 and Example 6-12, the deterioration was 10%, 6%, 8%, 5% and 14 in order. It can be seen that, in any case, it is greatly reduced as compared with the case where the fine cellulose fibers are not included.

As described above, a decrease in the coefficient of linear expansion can be considered as a factor for reducing deterioration of the durable life of the tooth portion at a high temperature due to the inclusion of the fine cellulose fibers. That is, the linear expansion coefficient of a toothed belt falls by containing a cellulose fine fiber. When the linear expansion coefficient decreases, the expansion of the tooth portion at a high temperature is suppressed. As a result, the meshing accuracy between the tooth part and the pulley is maintained even at a high temperature, and an increase in the burden on the tooth part due to the temperature rise is suppressed. I guess that.

-Abrasion resistance-
In Comparative Example 6 in which neither the toothed belt body nor the rubber paste adhesive layer contained cellulose fine fibers, the wear mass was 4.1 g. In Examples 6-1 to 6-4 and Examples 6-11 to 6-12 in which cellulose fine fibers are contained only in the toothed belt body, the wear mass is 3.9 g to 4. It was 3 g. Therefore, it can be seen that even if cellulose fine fibers are contained only in the toothed belt body, no particular improvement in wear resistance is observed.

On the other hand, in Examples 6-4 to 6-10 in which the content of cellulose fine fibers in the toothed belt body is the same 10 parts by mass, the content of cellulose fine fibers in the rubber paste adhesive layer is 0 respectively. While the weight parts are 1 part by weight, 3 parts by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, and 25 parts by weight, the wear mass is 4.2 g, 3.3 g, 2.5 g, 2 0.1 g, 1.8 g, 1.4 g, and 1.3 g. That is, it is understood that the wear mass decreases as the content of the cellulose fine fiber in the rubber paste adhesive layer increases. Here, if the wear mass is 3.5 g or less, it is considered that the wear mass is improved significantly over the conventional technique.

Further, in Examples 6-13 in which the toothed belt body does not contain cellulose fine fibers, the rubber paste adhesive layer contains 10 parts by weight of cellulose fine fibers, and the wear mass is 2.0 g. It can be seen that the wear resistance is improved.

From the above, it is considered that the effect of improving the wear resistance is exhibited by the inclusion of cellulose fine fibers in the rubber paste adhesive layer of the tooth side reinforcing fabric.

<Oil resistance test>
In Comparative Example 6 in which neither the toothed belt body nor the rubber paste adhesive layer contained cellulose fine fibers, the mass change amount before and after oil swelling as an evaluation index of oil resistance was 4.4%.

On the other hand, cellulose fine fibers are contained only in the toothed belt body, and the contents thereof are 0 parts by weight, 1 part by weight, 3 parts by weight, 5 parts by weight, 10 parts by weight, and 15 parts by weight, respectively. In Examples 6-1 to 6-4 and Examples 6-11 to 6-12 having 25 parts by mass, the mass change amounts were 3.9%, 3.7%, 3.1%, 2.8%, 1.9%, and 1.5%. That is, in the range of the present Example, it turns out that mass change amount becomes small as content of a cellulose fine fiber increases, and oil resistance improves.

In Examples 6-4 to 6-10 in which the content of cellulose fine fibers in the toothed belt body is the same 10 parts by mass, the content of cellulose fine fibers in the rubber paste adhesive layer is 0 parts by mass, respectively. 1 part by mass, 3 parts by mass, 5 parts by mass, 10 parts by mass, 15 parts by mass, and 25 parts by mass, while the mass change amount is 2.8%, 2.8%, 2.7% in order. 2.6%, 2.3%, 2.2%, and 2.1%. That is, it can be seen that as the content of the cellulose fine fiber in the rubber paste adhesive layer increases, the mass change rate decreases, and the oil resistance improves.

Further, in Example 6-13 in which only 10 parts by mass of cellulose fine fiber was contained only in the adhesive layer of rubber paste, the mass change rate was 4.3%, which was slightly suppressed from 4.4% of Comparative Example 6. Has been. In the case of Example 6-8 in which the content of cellulose fine fibers in the toothed belt body is 10 parts by mass, the content of cellulose fine fibers in the rubber paste adhesive layer is the same as in Example 6-13, but the rate of mass change Is 2.3%.

From the above, it is possible to improve the oil resistance by containing cellulose fine fibers in the toothed belt body, and even when cellulose fine fibers are contained only in the rubber paste adhesive layer of the tooth side reinforcing fabric, the effect is Even if it is small, it can be seen that the oil resistance is improved. It can also be seen that when the fine cellulose fibers are contained in the rubber paste adhesive layer in addition to the toothed belt body, the oil resistance is significantly improved.

The present invention is useful as a transmission belt.

10 V-ribbed belt body 11 Compressed rubber layer 12 Adhesive rubber layer 13 Back rubber layer 16 Short fiber
120 Flat belt body 121 Inner rubber layer 122 Adhesive rubber layer 123 Outer rubber layer 126 Short fiber
310 toothed belt body 311a base 311b tooth 312 core 313 tooth side reinforcing cloth 314 RFL adhesive layer 315 rubber glue adhesive layer

Claims

In a transmission belt that is wound around a pulley and transmits power,
A power transmission belt comprising a layer made of a rubber composition containing cellulosic fine fibers and short fibers having an average diameter of 1 μm or more.
The power transmission belt according to claim 1,
A power transmission belt characterized in that a fiber diameter distribution range of the cellulosic fine fibers includes 20 to 500 nm.
The power transmission belt according to claim 1 or 2,
A power transmission belt characterized in that carbon black is not blended in the rubber composition.
The transmission belt according to any one of claims 1 to 3,
The power transmission belt, wherein the cellulosic fine fibers are produced by mechanical defibrating means.
The transmission belt according to any one of claims 1 to 3,
The power transmission belt, wherein the cellulosic fine fibers are produced by chemical defibrating means.
In the transmission belt according to any one of claims 1 to 5,
A power transmission belt characterized in that a fiber diameter distribution range of the cellulosic fine fibers includes 50 to 500 nm.
The transmission belt according to any one of claims 1 to 6,
A power transmission belt having a content of 1 to 25 parts by mass of the cellulose-based fine fibers with respect to 100 parts by mass of a rubber component of the rubber composition.
The transmission belt according to any one of claims 1 to 7,
The rubber composition is a power transmission belt containing short fibers having a fiber diameter of 10 μm or more.
The transmission belt according to claim 8,
A power transmission belt in which the content of the short fiber relative to 100 parts by mass of the rubber component of the rubber composition is larger than the content of the cellulosic fine fibers relative to 100 parts by mass of the rubber component of the rubber composition.
The transmission belt according to any one of claims 1 to 9,
The transmission belt is
A toothed belt main body having a flat belt-like base portion and a plurality of tooth portions integrally provided at a distance in the belt length direction on one surface of the base portion;
A tooth-side reinforcing cloth pasted to cover the tooth-side surface of the toothed belt body through an adhesive layer containing a rubber component;
A toothed belt with
At least one of the base part, the tooth part, and the adhesive layer is formed of the rubber composition containing cellulosic fine fibers and short fibers having an average diameter of 1 μm or more.
The power transmission belt according to claim 10,
The power transmission belt, wherein the content of the cellulose fine fibers in the rubber composition is 1 to 30 parts by mass with respect to 100 parts by mass of the rubber component.
The power transmission belt according to claim 10 or 11,
A power transmission belt, wherein the rubber component of the rubber composition forming the toothed belt body includes hydrogenated acrylonitrile rubber.
The transmission belt according to any one of claims 10 to 12,
A power transmission belt, wherein the rubber component contained in the adhesive layer includes hydrogenated acrylonitrile rubber and hydrogenated acrylonitrile rubber reinforced with an unsaturated carboxylic acid metal salt.