CN117946463A

CN117946463A - Cold-resistant rubber for synchronous belt and preparation method thereof

Info

Publication number: CN117946463A
Application number: CN202410114214.5A
Authority: CN
Inventors: 叶海峰
Original assignee: Shanghai Wutong Synchronous Belt Co ltd
Current assignee: Shanghai Wutong Synchronous Belt Co ltd
Priority date: 2024-01-28
Filing date: 2024-01-28
Publication date: 2024-04-30

Abstract

The invention provides cold-resistant rubber for a synchronous belt, which comprises the following raw materials in parts by weight: 20-50 parts of chloroprene rubber, 20-50 parts of chlorostyrene modified chloroprene rubber, 30-50 parts of butadiene rubber, 5-15 parts of vulcanizing agent, 1-5 parts of vulcanization accelerator, 1-3 parts of rubber adhesive, 50-70 parts of modified carbon black, 2-15 parts of plasticizer, 1-4 parts of anti-aging agent, 0.5-3 parts of softener and 0.5-3 parts of lubricant. The minimum temperature use temperature of the cold-resistant rubber for the synchronous belt provided by the invention can reach 50 ℃ below zero, other properties of the rubber are not affected, and the cost is reasonable.

Description

Cold-resistant rubber for synchronous belt and preparation method thereof

Technical Field

The invention relates to cold-resistant rubber, in particular to cold-resistant rubber for a synchronous belt and a preparation method thereof.

Background

The synchronous belt is a novel conveyor belt developed by combining the advantages of belt transmission, chain transmission and gear transmission. The timing belt generally comprises three parts, a rubber body, a carcass material and a cloth covering layer. The rubber main body is generally polyurethane or chloroprene rubber, the framework material is generally copper-plated steel wires, glass fibers or aramid fiber ropes, and the wrapping layer is generally nylon materials.

Early synchronous belts were made of polyurethane rubber by casting, and tooth-wrapping cloth could not be placed on the synchronous belts produced by casting, so that the wear resistance was poor compared with neoprene belts with wear-resistant nylon wrapping cloth, and the heat resistance and water resistance of polyurethane rubber were poor, so that the synchronous belts could not be widely used in various fields. The neoprene has excellent stretching performance and dynamic fatigue performance, contains chlorine groups, so that the neoprene has excellent weather aging resistance, oil resistance and ozone resistance, and can release hydrogen chloride gas when the neoprene burns to dilute the oxygen concentration, and has better flame retardance and heat resistance, and researches show that the lowest temperature application range of the neoprene synchronous belt is-30 ℃ to-40 ℃ and cannot meet the use requirement in a cold environment of-50 ℃. The temperature change in northern areas is obvious, the temperature difference is large, the temperature is dry, the extreme temperatures are high and low alternately, and all weather factors can influence the performance of rubber materials.

Patent CN103073765A discloses a rubber dam with high cold resistance, which breaks the regularity of the chloroprene rubber molecular chain by introducing 2 and 3 units of chlorine atoms into chloroprene, thus obtaining a cold-resistant rubber with excellent cold resistance, but the rubber can only be used under the condition of minimum-31 ℃, which shows that the method of breaking the regularity of the chloroprene rubber molecular chain by introducing 2 and 3 units of chlorine atoms has no obvious effect. Styrene is used as a modifier of the chloroprene rubber in an attempt by researchers in the field to break the regularity of the molecular chain of the chloroprene rubber so as to reduce the crystallization capability of the chloroprene rubber to enhance the cold resistance of the chloroprene rubber, but the addition of the styrene reduces the chlorine content in the chloroprene rubber, thereby affecting the self-extinguishing performance of the chloroprene rubber in terms of oxidation resistance, ozone resistance and ignition resistance.

Patent CN101353453a discloses a neoprene composition with improved cold resistance, which is preferably a neoprene which is difficult to crystallize, and other gum types and other compounding agents which can interfere with crystallization of the neoprene are added, so that the neoprene composition can be used under the condition of-50 ℃, but most of the preferred neoprene which is difficult to crystallize has high import cost.

Therefore, the cold-resistant rubber for the synchronous belt, which has the lowest temperature of-50 ℃ and does not affect other properties of the rubber, and has reasonable cost, is urgently needed in the market.

Disclosure of Invention

Aiming at the problems existing in the prior art, the invention aims to obtain the cold-resistant rubber for the synchronous belt, which has the lowest temperature use temperature of-50 ℃ and has no influence on other properties of the rubber and reasonable cost.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

the invention provides cold-resistant rubber for a synchronous belt, which comprises the following raw materials in parts by weight: 20-50 parts of chloroprene rubber, 20-50 parts of chlorostyrene modified chloroprene rubber, 30-50 parts of butadiene rubber, 5-15 parts of vulcanizing agent, 1-5 parts of vulcanization accelerator, 1-3 parts of rubber adhesive, 50-70 parts of modified carbon black, 2-15 parts of plasticizer, 1-4 parts of anti-aging agent, 0.5-3 parts of softener and 0.5-3 parts of lubricant.

For the problem that neoprene cannot be used at-50 ℃, the applicant selects a method for blending neoprene with butadiene rubber to improve the cold resistance of neoprene, because the minimum use temperature of butadiene rubber is about-60 ℃, and the minimum use temperature of neoprene composition can be reduced after blending.

In some embodiments, the invention defines a mass ratio of neoprene to chlorostyrene modified neoprene of 1:1 to 2:1.

The applicant has defined the mass ratio of neoprene to chlorostyrene-modified neoprene because chlorostyrene-modified neoprene is more costly than neoprene, and the cost can be controlled by selecting the appropriate mass ratio in order to obtain cold-resistant rubber within the appropriate cost range.

In some embodiments, the method of making a chlorostyrene modified neoprene comprises the steps of:

(1) The chloroprene monomer and the chlorostyrene monomer are sent into a polymerization kettle, a pH regulator is added to regulate the pH to 7-8, an emulsifying agent, soft water and a dispersing agent are added after stirring, and finally an initiator is added to polymerize at the temperature of 30-50 ℃;

(2) Adding a terminator to perform termination reaction when the conversion rate reaches 60% -80%;

(3) Stripping the generated glue solution by steam to remove unreacted monomer chloroprene and chlorostyrene, breaking the chain, uniformly mixing, adjusting the pH value to 7-8, freezing and condensing at-5-7 ℃, washing by hot water at 40-50 ℃, drying, dicing and cooling to obtain the finished product of chlorostyrene modified chloroprene rubber.

Preferably, the emulsifier is OP-10.

Preferably, the dispersant is sodium dodecyl sulfate.

Preferably, the initiator is potassium persulfate.

Preferably, the terminator is a dialkyldithiocarbamate.

In some embodiments, the chlorostyrene is 5% -10% of the mass of chloroprene.

In some embodiments, the chlorostyrene comprises any one or more of 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene.

The low temperature resistance of the chloroprene rubber is closely related to the crystallization performance of the chloroprene rubber, the chloroprene rubber molecules are in a regular linear arrangement structure, so that the chloroprene rubber has high crystallinity, the chloroprene rubber modified chloroprene rubber is the chloroprene rubber copolymerized by using the styrene containing chlorine groups as a second monomer, the crystallization capability of the chloroprene rubber can be reduced due to the fact that the presence of the chlorostyrene destroys the regularity of the polychloroprene, the chloroprene rubber has better low temperature resistance, meanwhile, the existence of chlorine elements with stable chemical properties and benzene ring structures in the chlorostyrene further increases the self-extinguishing performance of the chloroprene rubber in terms of oxidation resistance, ozone resistance and ignition resistance, but when the chlorostyrene content is too high, the mechanical property of the chloroprene rubber is also affected to a certain extent due to the fact that the crystallization capability of the chloroprene rubber is reduced.

In some embodiments, the rubber adhesive is resorcinol micelle.

Preferably, the resorcinol colloidal particle is of the type R80.

The rubber adhesive can effectively improve the adhesive strength of the chloroprene rubber and the framework material, can be directly added with rubber material in the mixing process, generates crosslinking reaction during vulcanization to generate adhesive effect, uses more resorcinol in the rubber adhesive, has excellent comprehensive performance of the corresponding rubber material, but has serious fuming of resorcinol and serious harm to environment and occupational health.

R80 is a form of pre-dispersed master batch of resorcinol 80% and rubber carrier 20%, and dust flying and irritating smoke are not generated in the subsequent rubber mixing process of preparing the tire, so that the working environment can be greatly improved, and the health of workers is protected.

In some embodiments, the plasticizer is selected from any one or more of dioctyl sebacate, dioctyl adipate, diisononyl cyclohexane-1, 2-dicarboxylate.

The applicant can reduce the acting force among the molecules of the chloroprene rubber by optimizing the cold-resistant plasticizer, so that the vitrification temperature of the chloroprene rubber is reduced, the plasticity and the fluidity of the chloroprene rubber are enhanced, the shaping operations such as calendaring and extrusion are facilitated, the hardness and the elasticity of vulcanized rubber can be improved, and the cold resistance can be improved.

In some embodiments, the cold resistant rubber for a synchronous belt further comprises 3-5 parts by weight of aerogel.

In some embodiments, the aerogel comprises any one or more of silica aerogel, alumina aerogel, titania aerogel.

Preferably, the aerogel is a silica aerogel.

The aerogel is a three-dimensional nano porous material with ultrahigh porosity, a space reticular medium in the gel is converted from liquid into gas by removing a solvent in the gel, the appearance is a novel environment-friendly material with solid, the aerogel has the characteristic of high porosity, the uniform and compact nano pores and the multi-level fractal pore microstructure can effectively prevent air convection, the temperature conduction speed is reduced, the rubber product is transferred from indoor to outdoor, and the outside low Wen Hennan is transferred into the rubber, so that the cold resistance of the rubber product can be improved.

Meanwhile, the applicant has unexpectedly found that the mechanical property of the neoprene composition can be greatly improved by adding a small amount of silica aerogel, and presumably, the aerogel and the neoprene chain form covalent bonds, so that the entanglement degree of the molecular chain is increased, the molecular chain is not easy to slide relatively, and the strength of the composition is enhanced; in addition, the penetration of the neoprene chains inside the aerogel increases interfacial interactions and adhesion between the macromolecular segments and the inorganic filler, thus improving the mechanical properties of the neoprene.

On the premise that the mechanical property of the neoprene composition can be greatly improved by a small amount of silicon dioxide, the applicant can reduce the addition amount of the modified carbon black, and the effect of reducing the cost is achieved.

In some embodiments, the modified carbon black is prepared by: preparing the carbon black oxidized by nitric acid into a carbon black aqueous solution with the concentration of 5% -15%, adding a coupling agent, isooctyl acrylate, acrylic acid and potassium persulfate, uniformly stirring at 60-80 ℃, and washing and drying to obtain the modified carbon black.

Preferably, the preparation method of the modified carbon black comprises the following steps:

(1) Putting 10g of carbon black into a three-neck flask with the volume of 500ml, adding a prepared 8mol/L nitric acid solution into the three-neck flask to 300ml, stirring at the reaction temperature of 80 ℃ for reflux reaction for 8 hours, repeatedly filtering the reacted product to be neutral by using a Buchner funnel, and finally putting the filtered carbon black into an electric heating constant-temperature blast drying box, and drying at 50 ℃ to constant weight to obtain oxidized carbon black;

(2) Uniformly stirring oxidized carbon black and deionized water in a mass ratio of 1:10, and performing ultrasonic treatment for 30 minutes to obtain oxidized carbon black aqueous solution;

(3) Regulating the pH of the carbon black aqueous solution to 7-8, continuing ultrasonic treatment for 30 minutes, then adding a silane coupling agent, isooctyl acrylate and acrylic acid, wherein the mass ratio of the carbon black aqueous solution to the silane coupling agent is 100:3-100:1, adding potassium persulfate with the mass of 0.01% of the system, and heating to 60 ℃ to react for 12 hours;

(4) And (3) carrying out vacuum filtration on the solution obtained in the step (3), washing with ethanol and deionized water for three times, and putting the obtained solid matter into a vacuum oven to dry for 24 hours at 50 ℃ to obtain the modified carbon black loaded with isooctyl acrylate.

Preferably, the acrylate ester is isooctyl acrylate.

In some embodiments, the mass ratio of carbon black aqueous solution, isooctyl acrylate, and acrylic acid is 100:5-3:0.5-1.

In some embodiments, the coupling agent is an elemental sulfur-containing coupling agent.

Preferably, the silane coupling agent is bis- [ gamma- (triethoxysilyl) propyl ] tetrasulfide and/or 3-mercaptopropyl trimethoxysilane.

Further preferably, the silane coupling agent is bis- [ gamma- (triethoxysilyl) propyl ] tetrasulfide (SI-69).

Carbon black has many advantages as a filler, and can increase the hardness and strength of rubber, so that the rubber is more wear-resistant, ageing-resistant and weather-resistant, the carbon black can promote the improvement of the elasticity and flexibility of the rubber, in addition, the carbon black can improve the oil resistance, solvent resistance and cold resistance of the rubber, and finally, the carbon black can improve the processability of the rubber, but the uneven easy dispersion of the conventionally used carbon black leads to the influence on the mechanical property, processability and appearance quality of the rubber, so that the surface of the carbon black needs to be modified to increase the dispersibility of the carbon black.

The applicant selects the sulfur-containing silane coupling agent in the surface modification of the carbon black, because the sulfur-containing silane coupling agent can react with the surface of the carbon black to enable the carbon black to have better dispersibility, and the sulfur-containing silane coupling agent can participate in the vulcanization process of the chloroprene rubber composition, maintain the vulcanization balance to increase reversion resistance, thereby increasing the tear resistance, shearing resistance, heat resistance and the like of vulcanized rubber.

Acrylic ester substances are often used by scientific researchers in the field to modify rubber so as to improve the adhesive property, thermal performance, high temperature resistance and the like of the rubber, but no one considers the influence of acrylic ester on the cold resistance of chloroprene rubber, and acrylic ester with higher glass transition temperature than chloroprene rubber, such as methyl methacrylate, ethyl methacrylate, isobornyl methacrylate and the like, is selected, so that the glass transition temperature of the whole rubber is increased, and the cold resistance of the rubber is deteriorated; the acrylate with lower glass transition temperature than the chloroprene rubber, such as methyl acrylate, isooctyl acrylate and the like, can reduce the overall glass transition temperature of the rubber, so that the cold resistance of the rubber is better, but the conventional method for modifying the chloroprene rubber by using the acrylate is to blend the acrylate with the chloroprene rubber, then polymerize in the vulcanization process, the phenomenon that the chloroprene rubber and the acrylate chain segments alternately appear easily occurs in the vulcanization process, the good modification effect on the chloroprene rubber is not achieved, and the overall performance of the chloroprene rubber is easily influenced.

The invention selects the method of reacting acrylic acid with active hydroxyl on the surface of carbon black and then grafting acrylic ester onto the carbon black, and discovers that the problem that acrylic ester cannot be polymerized with chloroprene rubber well in acrylic ester modified chloroprene rubber can be solved, because the dispersion of the carbon black can drive the dispersion of acrylic ester grafts on the surface of the carbon black, and better modification effect is given to the chloroprene rubber.

The glass transition temperature of the isooctyl acrylate is-70 ℃, and the glass transition temperature of the rubber can be further reduced after the isooctyl acrylate is polymerized with the chloroprene rubber, so that the cold resistance of the rubber is improved.

In the preparation process of the modified carbon black, the grafting effect of the isooctyl acrylate can be ensured by controlling the mass ratio of the carbon black aqueous solution to the isooctyl acrylate to the acrylic acid to be 100:5-3:0.5-1, when the content of the acrylic acid is too high, the acrylic acid is easy to graft and polymerize to influence the isooctyl acrylate to be uniformly grafted on the surface of the carbon black, the isooctyl acrylate is wrapped in a chain to play a role in modifying, and when the content of the acrylic acid is too low, the surface of the carbon black cannot provide too many groups to graft the isooctyl acrylate on the carbon black.

In some embodiments, the carbon black is a combination of N330 carbon black and N550 carbon black.

N330 carbon black is a highly dispersed fine-grained carbon black, and can be used in rubber products to increase the strength, hardness, wear resistance and ageing resistance of rubber products, while N550 carbon black is a medium-grain-size carbon black, and can be used in rubber to endow rubber with higher stiffness, extrusion speed and smooth surface, and the combination of the two carbon blacks is more beneficial to the improvement of the comprehensive performance of the rubber.

Preferably, the mass ratio of the N330 carbon black to the N550 carbon black is 6:5-8:5.

The invention also provides a preparation method of the cold-resistant rubber for the synchronous belt, which comprises the following steps:

(1) Weighing all raw materials according to parts by weight;

(2) Respectively placing chloroprene rubber, chlorostyrene modified chloroprene rubber and butadiene rubber into an open mill for plasticating at 70-80 ℃ for 1-1.2 hours to obtain plasticated chloroprene rubber, chlorostyrene modified chloroprene rubber and butadiene rubber;

(3) Pouring plasticated chloroprene rubber, chlorostyrene modified chloroprene rubber, butadiene rubber, a vulcanizing agent, a vulcanization accelerator and a rubber adhesive into an open mill, rolling together modified carbon black, a plasticizer, an anti-aging agent, a softener, a lubricant, a silane coupling agent and aerogel until a sizing material wrapping roller has no viscous liquid on the surface, and then standing the next piece for 2-3 days;

(4) Finally, vulcanizing the formed rubber in a flat vulcanizing machine to obtain the cold-resistant rubber; the vulcanization temperature is 145-150 ℃, the vulcanization time is 50-60 minutes, and the vulcanization pressure is 10-15 MPa.

In some embodiments, the vulcanizing agent is selected from any one or more of a sulfur vulcanizing agent, a metal oxide vulcanizing agent, a peroxide vulcanizing agent, a resin vulcanizing agent, a quinone oxime vulcanizing agent, a polyamine vulcanizing agent.

Preferably, the vulcanizing agent is a combination of S-80, zinc oxide and magnesium oxide.

Further preferably, the mass ratio of S-80, zinc oxide and magnesium oxide is 1:8-12:7-10.

In some embodiments, the vulcanization accelerator may be selected from any one or more of the commercially available.

Preferably, the vulcanization accelerator is a combination of SA, DM and ETU.

Further preferably, the mass ratio of SA, DM and ETU is 1-2:1:1-2.

In some embodiments, the softening agent may be selected from any one or more of those commercially available.

Preferably, the softening agent is RX-80.

In some embodiments, the lubricant may be selected from any one or more of the commercially available.

Preferably, the lubricant is polyethylene wax.

In some embodiments, the anti-aging agent may be selected from any one or more of the commercially available agents.

Preferably, the anti-aging agent is a combination of BLE and RD.

Further preferably, the mass ratio of BLE and RD is 1-2:1-2.

Compared with the prior art, the invention has the following beneficial effects:

(1) According to the application, the chlorostyrene modified chloroprene rubber, aerogel and modified carbon black are added into the chloroprene rubber to prepare the cold-resistant rubber for the synchronous belt, which has the lowest temperature use temperature of-50 ℃ and has no influence on other properties of the rubber, and has reasonable cost.

(2) According to the application, the regularity of polychloroprene is destroyed by adding the copolymerization of chlorostyrene and chloroprene, the crystallization capability of the chloroprene rubber can be reduced, so that the chloroprene rubber has better low temperature resistance, and meanwhile, the oxidation resistance and ozone resistance of the chloroprene rubber are further improved due to the introduction of chlorine element and benzene ring in the chlorostyrene.

(3) According to the application, the dispersion performance of the carbon black in the chloroprene rubber composition is improved by grafting the isooctyl acrylate on the carbon black, meanwhile, the cold resistance of the rubber is improved by utilizing the characteristic that the isooctyl acrylate has a low glass transition temperature, the phenomenon that chloroprene rubber and acrylate chain segments are alternately arranged in the rubber-cited acrylic resin is solved, and a better modification effect is given to the chloroprene rubber.

(4) According to the application, the sulfur-containing silane coupling agent is used for modifying the carbon black, so that the dispersion performance of the carbon black in the chloroprene rubber composition is improved, the sulfur-containing silane coupling agent can improve the vulcanization effect to enhance the performance of the vulcanized chloroprene rubber composition, and the problem that the silane coupling agent is easy to separate out when being directly added into rubber is solved due to the combination of the silane coupling agent and the carbon black.

(5) According to the application, the temperature conduction speed can be reduced by adding the aerogel into the rubber, so that the outside low Wen Hennan is transmitted into the rubber after the rubber product is from indoor to outdoor, the cold resistance of the rubber product is improved, and meanwhile, the mechanical property of the chloroprene rubber composition can be obviously improved by finding out a small amount of aerogel.

Detailed Description

The invention will be described below in connection with specific embodiments. The following examples are illustrative of the present invention and are not intended to limit the present invention. Other combinations and various modifications within the spirit of the invention may be made without departing from the spirit or scope of the invention.

In the following examples and comparative examples, the remaining compound monomers and related reagents used were commercially available except for chlorostyrene modified neoprene and modified carbon black, wherein neoprene was purchased from Shanghai Seattle Co., ltd; butadiene rubber was purchased from chinese petrochemical single mountain petrochemical company; r80 is purchased from Qingdao Fukai rubber and plastic New Material Co., ltd; s-80, polyethylene wax, DM, ETU, resorcinol colloidal particles, SA, RX-80, BLE, RD, SI-69, N330 and N550 carbon blacks were purchased from Guangzhou Kogyo Seda rubber raw materials trade Co., ltd; the pH adjustor is purchased from Hubei Watson chemical technology Co., ltd; SI-60 was purchased from nanjing product-coupling agent limited and silica aerogel was purchased from guangxi guangshen environmental protection technology limited.

Preparation example 1

The preparation method of the chlorostyrene modified chloroprene rubber-1 comprises the following steps:

(1) 100 parts by weight of chloroprene monomer and chlorostyrene monomer are fed into a polymerization kettle (the mass of the chlorostyrene monomer is 7% of that of the chloroprene monomer), a pH regulator is added to regulate the pH to 8, 0.5 part of OP-10, 150 parts of soft water and 0.7 part of sodium dodecyl sulfate are added after stirring, and finally 0.2 part of potassium persulfate is added to polymerize at the temperature of 40 ℃;

(2) Adding dialkyl dithiocarbamate to carry out termination reaction when the conversion rate reaches 70%;

(3) Stripping the glue solution generated in the step (2) by steam to remove unreacted monomer chloroprene and chlorostyrene, breaking the chain, uniformly mixing, adjusting the pH value to 8, freezing and condensing at the temperature of minus 5 ℃, washing with hot water at the temperature of 50 ℃, drying, dicing and cooling to obtain a chlorostyrene modified chloroprene rubber finished product.

Preparation example 2

The procedure for the preparation of the chlorostyrene-modified neoprene-2 was essentially the same as in preparation example 1, except that the amount of chlorostyrene was 4% by mass of the chloroprene.

Preparation example 3

The procedure for the preparation of chlorostyrene-modified neoprene-3 was essentially the same as in preparation example-1, except that the amount of chlorostyrene was 11% of the mass of chloroprene.

Preparation example 4

The styrene-modified chloroprene rubber was prepared in the same manner as in preparation example 1, except that the chlorostyrene monomer was replaced with styrene.

Preparation example 5

The preparation method of the modified carbon black-1 comprises the following steps:

(1) Putting 10g of carbon black into a three-neck flask with a volume of 500ml, wherein the mass ratio of N330 carbon black to N550 carbon black in the carbon black is 7:5, adding a prepared 8mol/L nitric acid solution into the three-neck flask to 300ml, stirring at a reaction temperature of 80 ℃ and carrying out reflux reaction for 8 hours, repeatedly filtering the reacted product to be neutral by using a Buchner funnel, and finally, putting the filtered carbon black into an electrothermal constant-temperature blast drying box, and drying at 50 ℃ to constant weight to obtain oxidized carbon black;

(2) Uniformly stirring the oxidized carbon black obtained in the step (1) and deionized water in a mass ratio of 1:10, and performing ultrasonic treatment for 30 minutes to obtain a carbon black aqueous solution;

(3) Regulating the pH of a carbon black aqueous solution to 7, continuing ultrasonic treatment for 30 minutes, then adding SI-69, isooctyl acrylate and acrylic acid, wherein the mass ratio of the carbon black aqueous solution to the isooctyl acrylate to the acrylic acid is 100:4:0.5, the mass ratio of the carbon black aqueous solution to SI-60 is 100:2, adding potassium persulfate with the mass of 0.01% of the system, and heating to 60 ℃ for reaction for 12 hours;

(4) And (3) carrying out vacuum filtration on the solution obtained in the step (3), washing the solution for three times by using ethanol and deionized water, putting the obtained solid matters into a vacuum oven, and drying the solid matters for 24 hours at 50 ℃ to obtain the modified carbon black loaded with isooctyl acrylate.

Preparation example 6

The procedure for preparing modified carbon black-2 was substantially the same as in preparation example 5, except that the mass ratio of the aqueous carbon black solution, isooctyl acrylate and acrylic acid was 10:1:4.

Preparation example 7

The procedure for preparing modified carbon black-3 was substantially the same as in preparation example 5, except that the mass ratio of the aqueous carbon black solution, isooctyl acrylate and acrylic acid was 10:4:0.1.

Example 1

The cold-resistant rubber for the synchronous belt comprises the following raw materials in parts by weight: 35 parts of chloroprene rubber, 25 parts of chlorostyrene modified chloroprene-1, 30 parts of butadiene rubber, 5 parts of zinc oxide, 4 parts of magnesium oxide, 10 parts of S-80, 1.5 parts of SA, 1 part of DM, 2 parts of ETU, 2 parts of resorcinol colloidal particles, 10 parts of dioctyl sebacate, 2 parts of BLE, 2 parts of RD, 2 parts of RX-80, 2 parts of polyethylene wax, 5 parts of SI-69 and 70 parts of modified carbon black-1.

The preparation method of the cold-resistant rubber comprises the following steps:

(1) Weighing all raw materials according to parts by weight;

(2) Respectively placing chloroprene rubber, chlorostyrene modified chloroprene rubber-1 and butadiene rubber into an open mill for plasticating, wherein the plasticating temperature is 75 ℃, and the plasticating time is 1 hour, so as to obtain plasticated chloroprene rubber, chlorostyrene modified chloroprene rubber and butadiene rubber;

(3) Pouring plasticated chloroprene rubber, chlorostyrene modified chloroprene rubber, butadiene rubber, zinc oxide, magnesium oxide, S-80, RX-80, SA, DM, ETU, resorcinol colloidal particles, modified carbon black-1, dioctyl sebacate, BLE, RD, polyethylene wax and SI-69 into an open mill together until a sizing material wrapping roller has no viscous liquid on the surface, and then placing the lower piece for 2 days;

(4) Finally, vulcanizing the formed rubber in a flat vulcanizing machine at 145 ℃ for 55 minutes under a vulcanizing pressure of 12MPa.

Example 2

The cold-resistant rubber for the synchronous belt comprises the following raw materials in parts by weight: 20 parts of chloroprene rubber, 20 parts of chlorostyrene modified chloroprene-1, 50 parts of butadiene rubber, 4 parts of zinc oxide, 3.5 parts of magnesium oxide, 0.5 part of S-80, 1 part of SA, 1 part of DM, 1 part of ETU, 2 parts of resorcinol colloidal particles, 10 parts of dioctyl sebacate, 1 part of BLE, 1 part of RD, 2 parts of RX-80, 2 parts of polyethylene wax, 5 parts of SI-69 and 70 parts of modified carbon black-1.

(1) Weighing all raw materials according to parts by weight;

(2) Respectively placing chloroprene rubber, chlorostyrene modified chloroprene rubber-1 and butadiene rubber into an open mill for plasticating, wherein the plasticating temperature is 70 ℃, and the plasticating time is 1 hour, so as to obtain plasticated chloroprene rubber, chlorostyrene modified chloroprene rubber and butadiene rubber;

(4) Finally, vulcanizing the formed rubber in a flat vulcanizing machine at 145 ℃ for 50 minutes under 10MPa.

Example 3

The cold-resistant rubber for the synchronous belt comprises the following raw materials in parts by weight: 50 parts of chloroprene rubber, 50 parts of chlorostyrene modified chloroprene-1, 50 parts of butadiene rubber, 6 parts of zinc oxide, 5 parts of magnesium oxide, 0.5 part of S-80, 2 parts of SA, 1 part of DM, 2 parts of ETU, 2 parts of resorcinol colloidal particles, 10 parts of dioctyl sebacate, 2 parts of BLE, 2 parts of RD, 2 parts of RX-80, 2 parts of polyethylene wax, 5 parts of SI-69 and 70 parts of modified carbon black-1.

(1) Weighing all raw materials according to parts by weight;

(2) Respectively placing chloroprene rubber, chlorostyrene modified chloroprene rubber-1 and butadiene rubber into an open mill for plasticating, wherein the plasticating temperature is 80 ℃, and the plasticating time is 1.2 hours, so as to obtain plasticated chloroprene rubber, chlorostyrene modified chloroprene rubber and butadiene rubber;

(3) Pouring plasticated chloroprene rubber, chlorostyrene modified chloroprene rubber, butadiene rubber, zinc oxide, magnesium oxide, S-80, RX-80, SA, DM, ETU, resorcinol colloidal particles, modified carbon black-1, dioctyl sebacate, BLE, RD, polyethylene wax and SI-69 into an open mill together until a sizing material wrapping roller has no viscous liquid on the surface, and then placing the lower piece for 3 days;

(4) Finally, vulcanizing the formed rubber in a flat vulcanizing machine at 150 ℃ for 60 minutes under 15MPa.

Example 4

A cold-resistant rubber for a synchronous belt is basically the same as the formula of the example 1, except that chlorostyrene modified chloroprene rubber-1 is replaced with chlorostyrene modified chloroprene rubber-2.

The preparation method is the same as in example 1.

Example 5

A cold-resistant rubber for a synchronous belt is basically the same as the formula of the example 1, except that chlorostyrene modified chloroprene rubber-1 is replaced with chlorostyrene modified chloroprene rubber-3.

The preparation method is the same as in example 1.

Example 6

A cold-resistant rubber for a synchronous belt was substantially the same as the formulation of example 1, except that 3 parts by weight of silica aerogel was further added.

The preparation is the same as in example 1, wherein the silica aerogel is added in step (3).

Example 7

A cold-resistant rubber for a synchronous belt was substantially the same as the formulation of example 6, except that carbon black was reduced to 50 parts.

The preparation method is the same as in example 6.

Example 8

A cold-resistant rubber for a synchronous belt was substantially the same as the formulation of example 6, except that modified carbon black-1 was changed to modified carbon black-2.

The preparation method is the same as in example 6.

Example 9

A cold-resistant rubber for a synchronous belt was substantially the same as the formulation of example 6, except that modified carbon black-1 was changed to modified carbon black-3.

The preparation method is the same as in example 6.

Comparative example 1

The synchronous belt rubber comprises the following raw materials in parts by weight: 60 parts of neoprene, 30 parts of butadiene rubber, 5 parts of zinc oxide, 4 parts of magnesium oxide, 10 parts of S-80, 1.5 parts of SA, 1 part of DM, 2 parts of ETU, 2 parts of resorcinol colloidal particles, 10 parts of dioctyl sebacate, 2 parts of BLE, 2 parts of RD, 2 parts of RX-80, 2 parts of polyethylene wax, 5 parts of SI-69 and 70 parts of modified carbon black-1.

The preparation method is the same as in example 1.

Comparative example 2

The rubber for the synchronous belt comprises the following raw materials in parts by weight: 35 parts of chloroprene rubber, 25 parts of styrene modified chloroprene, 30 parts of butadiene rubber, 5 parts of zinc oxide, 4 parts of magnesium oxide, 10 parts of S-80, 1.5 parts of SA, 1 part of DM, 2 parts of ETU, 2 parts of resorcinol colloidal particles, 10 parts of dioctyl sebacate, 2 parts of BLE, 2 parts of RD, 2 parts of RX-80, 2 parts of polyethylene wax, 5 parts of SI-69 and 70 parts of modified carbon black-1.

The preparation method is the same as in example 1.

Comparative example 3

A synchronous belt rubber was prepared in substantially the same manner as in example 1 except that modified carbon black-1 was changed to unmodified carbon black (the mass ratio of N330 carbon black to N550 carbon black: 7:5).

The preparation method is the same as in example 1.

Performance testing

Test items and test criteria are shown in table 1.

TABLE 1

TABLE 2

As can be seen from the data of Table 2, the PC master batches in examples 1-9 of the invention have cold resistance at-50 ℃ and also have the characteristics of aging resistance and ozone resistance, wherein the comparison of comparative example 1 and example 1 shows that the cold resistance of cold-resistant rubber prepared by adding chlorostyrene modified styrene and modified carbon black is greatly improved; from comparison of comparative example 2 and example 1, it can be seen that cold-resistant rubber prepared with chlorostyrene has superior ozone resistance compared to cold-resistant rubber prepared with styrene; from the comparison of comparative example 3 and example 1, it can be seen that the mechanical properties of the composition are greatly improved due to the better dispersion of the modified carbon black in the neoprene composition; from the comparison of examples 1 to 3 and examples 4 and 5, it can be seen that the cold resistance of the chloroprene rubber composition is not satisfactory when the chlorostyrene content is too low, and the mechanical properties are slightly reduced due to the reduced crystallization ability of chlorostyrene when the chlorostyrene content is too high; after aerogel is added in the embodiment 6, the cold resistance and mechanical properties of the cold-resistant rubber are further improved; in the embodiment 7, the content of carbon black is reduced on the premise of adding aerogel, and the mechanical property and cold resistance of PC master batch are not greatly changed; from a comparison of example 6 and examples 8 and 9, it can be seen that the mass ratio of the aqueous carbon black solution, isooctyl acrylate and acrylic acid has a great influence on the cold resistance of the system.

The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the present invention and to implement it, but not limit the scope of the present invention, and all equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of the present invention.

Claims

1. The tunnel lining concrete construction joint sealant is characterized by comprising the following raw materials in percentage by weight: 100-120 parts of alpha, omega-dihydroxy polydimethylsiloxane, 10-30 parts of vinyl tributyl ketoxime silane, 1-3.5 parts of Beckmann rearrangement initiator, 60-80 parts of calcium carbonate, 60-80 parts of calcium oxide, 10-25 parts of simethicone, 1-3 parts of coupling agent, 0.01-0.1 part of tetra-n-butyl titanate, 0.5-1 part of initiator and 55-95 parts of plasticizer.

2. The tunnel lining concrete construction joint sealant according to claim 1, wherein the beckmann rearrangement initiator is triphenylphosphine and carbon tetrabromide.

3. A tunnel lining concrete construction joint sealant according to claim 3, wherein the mass ratio of triphenylphosphine to carbon tetrabromide is 2-4:1-2.

4. The tunnel lining concrete construction joint sealant according to claim 1, wherein the calcium carbonate is nano calcium carbonate and heavy calcium carbonate.

5. The tunnel lining concrete construction joint sealant according to claim 4, wherein the mass ratio of the nano calcium carbonate to the heavy calcium carbonate is 6-8:4-6.

6. The tunnel lining concrete construction joint sealant according to claim 1, wherein the coupling agent is KH-550 and KH-560.

7. The tunnel lining concrete construction joint sealant according to claim 1, wherein the particle size of the calcium oxide is 1200-1500 mesh.

8. The tunnel lining concrete construction joint sealant according to claim 7, wherein the plasticizer is one or more of dioctyl phthalate, diisononyl phthalate and diisodecyl phthalate.

9. The tunnel lining concrete construction joint sealant according to any one of claims 1 to 8, wherein the self-healing concrete waterproof and anti-corrosion additive further comprises 5 to 10 parts by weight of rare earth metal oxide.

10. The tunnel lining concrete construction joint sealant according to any one of claims 1 to 8, wherein the preparation method of the sealant comprises the steps of:

(1) Blending alpha, omega-dihydroxy polydimethylsiloxane, simethicone, calcium carbonate and calcium oxide for 2.5 to 3.5 hours under the conditions of vacuum degree of 0.085 to 0.09Mpa, rotating speed of 300 to 500rpm and temperature of 100 to 105 ℃;

(2) And (2) adding a Beckmann rearrangement initiator, calcium carbonate, calcium oxide, dimethyl silicone oil, a coupling agent, an initiator and a plasticizer into the product obtained in the step (1), and reacting for 0.8-1 hour at normal temperature under the vacuum degree of 0.085-0.09Mpa and the rotating speed of 200-300rpm to obtain the sealant.