JPH11241275A - Rubber reinforcing code and treating agent therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rubber reinforcing code having excellent adhesiveness with hydrogenated nitryl-based rubber by applying a treating agent containing a resorcin.formalin condensate and rubber latex to rubber reinforcing fibers and further applying a treating agent containing a specific rubber blended material, a curing agent and a curing auxiliary thereon. SOLUTION: This rubber reinforcing code is obtained by forming a first covering layer obtained by coating a treating agent containing a resorcin.formalin condensate and rubber latex on the surfaces of fibers for rubber reinforcement such as glass fibers or aramid fibers and dry-curing it, then providing a second covering layer by coating a treating agent composed of rubber blended materials consisting of a solution containing a rubber blended material consisting of a hydrogenated nitryl rubber and a hydrogenated nitryl rubber wherein zinc methacrylate is dispersed, a curing agent and a curing auxiliary such as N,N-(m)-phenylene dimaleimide on the first covering layer, followed by dry-curing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrogenated nitrile rubber (hereinafter referred to as "H-NBR") having excellent bending resistance and heat resistance.
The present invention relates to a rubber reinforcing cord used for reinforcing a mixed rubber comprising: a hydrogenated nitrile rubber in which zinc methacrylate is dispersed (hereinafter referred to as H-NBR / ZDMA).

[0002]

2. Description of the Related Art In order to improve the strength and durability of rubber products such as rubber belts and rubber tires, it is widely practiced to embed glass fibers, chemical fibers and the like as reinforcing fibers in rubber.

However, since the reinforcing fibers themselves generally have poor affinity with rubber and have poor adhesiveness, when the surface of the reinforcing fibers is embedded in rubber without processing, the reinforcing fibers do not adhere to the rubber. Adhesion is weak and easily peels off during use. In such a state, the reinforcing fiber cannot satisfy the performance required as a reinforcing material for rubber products.

For this reason, when various reinforcing fibers are used in rubber products, it is common practice to form a coating layer on the surface of the reinforcing fibers to improve the familiarity with the rubber used and to improve the adhesiveness. ing.

[0005] For example, a glass fiber cord (JP-A-63-270877) having a coating formed by applying a mixed treatment of a resorcin-formalin condensate and H-NBR latex to a glass fiber and drying and curing the glass fiber is exemplified. . Further, there has been proposed a rubber reinforcing fiber in which a second layer is coated with a halogen-containing polymer and isocyanate, and a third layer containing the same rubber as the matrix rubber is formed (Japanese Patent Publication No. 5-71710). However, the former cannot obtain sufficient adhesive strength with rubber mixed with H-NBR and H-NBR / ZDMA, and the latter requires three layers of coating, which complicates the production process and increases the cost.

[0006]

As described above, it is widely and generally practiced to form a coating layer on the surface of the reinforcing fiber in order to improve the adhesion between the rubber used and the reinforcing fiber. However, there are a wide variety of types of rubber and reinforcing fibers currently used, and if the types of rubber and reinforcing fibers are different, the types of coating layers for improving the adhesiveness are naturally different.

[0007] In recent years, H-NBR / ZDMA rubber has been receiving attention in various fields. The rubber obtained by mixing H-NBR / ZDMA rubber with H-NBR rubber has higher heat resistance than the conventionally used H-NBR rubber, and is used in a field where it could not be used conventionally, or compared with a conventional product. Can be used as a higher performance alternative.

[0008] The present invention relates to H-NBR and H-NBR /
When a reinforcing fiber is used for rubber containing ZDMA as a main component, a reinforcing cord having improved adhesion to the rubber and a coating layer of the reinforcing cord (the second layer on the reinforcing fiber) may be used.
The purpose of the present invention is to obtain a treating agent for forming a layer (surface treatment film).

[0009]

According to a first aspect of the present invention, there is provided a rubber reinforcing cord comprising a rubber reinforcing fiber comprising a resorcinol-formalin condensate and a rubber latex. A second coating layer formed by applying an agent and drying and curing to form a first coating layer, further applying a different treatment agent on the first coating layer, drying and curing to form a second coating layer, The treating agent contains a rubber compound, a vulcanizing agent and a maleimide-based vulcanizing aid as main components.

[0010] A rubber reinforcing cord according to a second aspect of the present invention is the cord according to the first aspect, wherein the vulcanization aid contained in the treating agent for the second coating layer is N, Nm-phenylenedimaleimide. It is.

According to a third aspect of the present invention, there is provided the rubber reinforcing cord according to the first or second aspect, wherein the rubber compound contained in the treating agent for the second coating layer comprises a hydrogenated nitrile rubber and zinc methacrylate. And a hydrogenated nitrile rubber in which is dispersed a mixed rubber.

[0012] The treatment agent of the invention according to claim 4 is the treatment agent for the second coating layer according to any one of claims 1 to 3.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, a rubber compound, a rubber coating,
By using a coating layer treating agent containing a vulcanizing agent and a maleimide-based vulcanizing aid, H-NBR and H-NBR can be obtained.
It has been found that the adhesion between the rubber containing / ZDMA as a main component and the reinforcing cord can be dramatically improved. Hereinafter, embodiments of the present invention will be described in detail.

The rubber reinforcing fiber used in the present invention is not limited, and specific examples thereof include glass fiber, polyvinyl alcohol fiber represented by vinylon fiber, polyester fiber, polyamide fiber such as nylon and aramid (aromatic polyamide). , Carbon fiber, polyparaphenylene benzoxazole fiber and the like. Among these, glass fibers and aramid fibers are preferably used. The type of glass fiber is not particularly limited, and non-alkali glass, high-strength glass, and the like can be used.
The filament diameter of the glass fibers is not particularly limited, but those having a diameter of 5 to 1.3 μm are generally used. Also, as aramid fiber, 500 to 5,000
Denier ones are commonly used. The form of these fibers includes stable, filament, cord,
As a specific example, a rope shape or a canvas can be used.

The rubber latex forming the first coating layer according to claim 1 is specifically a butadiene / styrene copolymer latex, a dicarboxylated butadiene / styrene copolymer latex, a vinylpyridine / butadiene / styrene. Terpolymer latex, chloroprene latex, butadiene rubber latex, chlorosulfonated polyethylene latex, acrylonitrile / butadiene copolymer latex, and nitrile group-containing highly saturated copolymer rubber latex are preferred.

The rubber compound contained in the treating agent for the second coating layer may be any one of various types depending on the type of the matrix rubber.
Alternatively, a plurality of mixed rubbers can be used. The type of rubber and its solvent are not limited. Examples of rubber include chloroprene rubber, chlorosulfonated polyethylene, H
-NBR or H-NBR / ZDMA or the like is used. These rubbers are selected in consideration of the compatibility and the like depending on the type of the matrix rubber. In particular, when the matrix rubber is a mixed rubber of H-NBR and H-NBR / ZDMA, the treating agent for the second coating layer is used. The same rubber compound dissolved in the same rubber is preferably used.

H-NBR and H-NBR / ZD to be dissolved
The weight ratio to MA is H-NBR / (H-NBR / ZDM).
A) = 45 to 80/55 to 20, preferably H-NBR
If the ratio of / ZDMA is small, sufficient adhesive strength cannot be obtained, and if the ratio is large, the cord becomes hard and the bending fatigue property deteriorates.

The H-NBR must have an iodine value of 120 or less from the viewpoint of the film strength of the rubber and the adhesiveness to the matrix rubber, and preferably has an iodine value of 0 to 100. Zetpol (trade name, manufactured by Zeon Corporation) can be suitably used as this rubber. The iodine value is a value determined according to JIS K0070.

As the H-NBR / ZDMA used in the present invention, ZSC (trade name, manufactured by Zeon Corporation) in which polyzinc methacrylate is dispersed in the above-mentioned zetpol can be suitably used.

The solvent for dissolving the rubber is benzene,
An aromatic hydrocarbon such as toluene or xylene, a halogenated hydrocarbon such as trichloroethylene, methyl ethyl ketone (hereinafter referred to as MEK), ethyl acetate, or the like is used. In the case of a compounded rubber such as the aforementioned H-NBR, MEK is usually used.

The vulcanizing agent contained in the treatment agent for the second coating layer includes:
Organic peroxides such as sulfur, dicumyl peroxide, 1,3-bis (t-butylperoxy-isopropyl) benzene, p-
Aromatic nitroso compounds such as dinitrosonaphthalene and p-dinitrosobenzene are exemplified. Many of these may be preliminarily compounded in the rubber compound, and are added when necessary.

As the maleimide-based vulcanization aid described in item 1, specifically, maleimide, phenylmaleimide, N, Nm-phenylenedimaleimide and the like can be used. In particular, N, Nm-phenylenedimaleimide according to claim 2 can be suitably used as a means for improving the adhesiveness.

The compounding ratio of the coating layer treating agent is as follows: rubber compound / vulcanizing agent / maleimide vulcanizing aid = 100 / 0-10
/ 1 to 150 parts by weight, and 100/0 to 6/30 to 8
It can be suitably used in the range of 0 parts by weight.

The treating agent for the second coating layer of the present invention may contain an inorganic filler such as carbon black, a plasticizer, an antioxidant, and other crosslinking aids.

The treating agent for the second coating layer of the glass fiber of the present invention is usually prepared as a solution or dispersion having a solid content of 3 to 25% by weight, more preferably 5 to 15% by weight.

The method of forming the second coating layer is not particularly limited, but usually, the rubber reinforcing fiber provided with the primary coating layer is immersed in a solvent tank containing a treating agent, and then dipped in a drying oven. , Forming a coating layer. Although the drying conditions are not limited, the drying is generally performed at 80 to 160 ° C. for 0.1 to 1 minute. The adhesion amount is 1 to 10%, preferably 3 to 7%.

[0027]

[Example 1] Glass fiber (E-glass: 9 μm)
Three glass filaments having a diameter of 200 were bundled, and a treating agent for a first coating layer having the following composition was applied by a known method.

[0028]

[Table 1] ---------------------------------------------- ---------------------- Composition Blending ratio (parts by weight) ------------------------------------ −−−−−−−−−−− Vinylpyridine latex (solid content 40%) 45 Chlorosulfonated polyethylene latex (solid content 40%) 20 Resorcin / formalin condensate (solid content 8%) 30 (resorcin / Formalin = 1 / 1.3 molar ratio) 25% ammonia water 1 water 4 --------------------------------- -----------------------------------

The glass fiber on which the first coating layer is formed is 8
After the twist / 10 cm priming, 11 strands are aligned and further 8 times / 10 cm twisted, then the second coating layer treating agent described below is applied and dried in the same manner as described above. It was cured and made into a glass fiber cord.

[0030]

[Table 2] ---------------------------------------------- Composition of treatment agent for coating layer Compounding ratio (parts by weight) Rubber composition 100 Toluene 416 Methyl ethyl ketone 180 N, Nm-phenylene Maleimide 50 ----------------------------------------------

The second coating layer was 5% by weight based on the weight of the glass fiber cord. Table 3 below shows the rubber compositions in Table 2 above.

[0032]

[Table 3] ---------------------------------------------- ---------------- Composition of rubber composition Compounding ratio (parts by weight) ------------------------------- −−−−−−−− ZETPOL2020 (* 1) 70 ZSC2000L (* 2) 30 ZnO 10 Stearic acid 1 Carbon black 30 TOTM (Trioctyl Trimellitate) 5 Sulfur 0.1 1,3-Bis- (t-butylperoxy-isopropyl) ) -benzene 6 ---------------------------------------------- ---------------- (* 1) Trade name H-NBR: manufactured by Zeon Corporation (* 2) Trade name H-NBR / ZDMA: manufactured by Zeon Corporation

In order to test the adhesion between the glass fiber cord and the mixed rubber composed of H-NBR and H-NBR / ZDMA, a test piece having a composition shown in Table 3 (width 25 mm × length 50 mm × thickness 5 mm) The glass fiber cords were arranged on the upper side along the long side, and bonded by heating at 160 ° C. for 30 minutes.

The test piece after the heat bonding was applied to a tensile tester and pulled in the fiber direction to measure the strength value.
The results are shown in Table 5 below.

Example 2 Instead of the glass fiber used in Example 1, an aramid fiber (Technola T202: 1500d, manufactured by Teijin Limited) was used, and the same treating agent for the first coating layer as in Example 1 was applied. Thereafter, the solid adhered rate was adjusted to 12%, and heat treatment was performed at 250 ° C. for 1 minute. This was plied twice and subjected to 3.1 times of twist per inch to obtain an aramid fiber cord. Using the aramid fiber cord thus obtained, a treatment was performed using the same treating agent for the second coating layer as in Example 1. The second coating layer was 10% by weight based on the weight of the aramid fiber cord. The method of evaluating the adhesion was the same as in Example 1.

Comparative Example 1 The second example used in Example 1 was used.
The second coating layer was formed using the processing agents shown in Table 4 below instead of the processing agents for forming the coating layer (described in Table 2). Other than that, the test was performed under the same conditions as in the example.

[0037]

[Table 4] ---------------------------------------- Composition Mixing ratio (parts by weight) ) ---------------- Rubber composition 100 Toluene 416 Methyl ethyl ketone 180 --------------------- -------------------

Comparative Example 2 A second coating layer was formed in Example 2 by using the treating agent shown in Table 4 used in Comparative Example 1 instead of the treating agent for the second coating layer used. . Otherwise, the test was performed under the same conditions as in Example 2.

[0039]

[Table 5]

[0040]

According to the present invention, H is excellent in bending resistance and heat resistance.
-Dramatically improving the adhesion between a compounded rubber comprising NBR and H-NBR / ZDMA and glass fiber, and using the glass fiber cord according to the present invention, as a result, enables use in a high temperature environment; In addition, it is possible to obtain an H-NBR rubber product having significantly improved durability.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code FI C08L 21/00 C08L 21/00 61/12 61/12 D06M 13/418 D06M 13/418 // C08J 5/06 CEQ C08J 5 / 06 CEQ

Claims (4)

[Claims] 1. A treatment agent containing a resorcinol-formalin condensate and rubber latex is applied to a rubber reinforcing fiber, dried and cured to form a first coating layer, and a different treatment agent is further applied on the first coating layer and dried. In a rubber reinforcing fiber cord having a second coating layer formed by curing, a treatment agent for the second coating layer contains a rubber compound, a vulcanizing agent, and a maleimide vulcanization aid as main components. Characteristic cord for rubber reinforcement. 2. The vulcanization aid contained in the second coating layer treatment agent is N, Nm-phenylenedimaleimide.
A rubber reinforcing cord according to the item. 3. The rubber compound contained in the second coating layer treating agent is a melt of a mixed rubber comprising a hydrogenated nitrile rubber and a hydrogenated nitrile rubber in which zinc methacrylate is dispersed. 3. The rubber reinforcing cord according to 2. 4. The treatment agent for a second coating layer according to claim 1, wherein