JP2002047356A - Composite of elastomer composition and fiber, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite composed of an ethylene-α-olefin elastomer and fibers, excellent in adhesion of the elastomer and the fibers, having excellent heat resistance, bending fatigue resistance and tensile strength and showing no decrease in adhesiveness by heat load and excellent in durability, and also to provide a method of manufacturing the same. SOLUTION: The composite consists of an elastomer composition (A) including the ethylene-α-olefin copolymer of 100 wt.pts. and the ethylene-α-olefin elastomer of 100 wt.pts. copolymerized with an ethylene unsaturated carboxylic acid metal salt of 10-80 wt.pts. and the fiber (B) which is coated with a mixture of a saturated copolymer rubber latex having nitrile groups and an iodine value of <=80 and a resorcin - formaldehyde precondensate. The elastomer composition and the fiber are bonded to each other by vulcanization. The method of manufacturing the composite is also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a rubber composition containing an ethylene-α-olefin copolymer rubber such as an ethylene-propylene copolymer rubber or an ethylene-propylene-diene terpolymer and a fiber material. The present invention relates to a composite having excellent adhesion between a rubber composition and a fiber material, exhibiting high heat resistance and bending fatigue resistance, having a large tensile stress, and having excellent durability, and a method for producing the same.

[0002]

2. Description of the Related Art Ethylene-propylene copolymer rubber (hereinafter referred to as "EPM") and ethylene-propylene-diene terpolymer rubber (hereinafter referred to as "EPDM").
Because of its excellent heat resistance, steam resistance, weather resistance, and ozone resistance, it is used as a rubber material for heat-resistant conveyor belts, radiator hoses for automobiles, steam hoses, and the like.

However, since EPM and EPDM have a small reinforcing effect by carbon black, they are not suitable for applications such as automobile tires and high load belts, which require high strength. In applications such as belts and hoses, rubber is used in combination with a fiber material.
PM and EPDM are rubbers that are difficult to adhere to fiber materials, and there has been a demand for improvement in adhesion to fiber materials.

Japanese Patent Application Laid-Open No. 9-216954 discloses EP
In the method for bonding a rubber composition comprising DM and a fiber material, the fiber material is immersed in a dip solution containing a resorcinol-formaldehyde precondensate and a nitrile group-containing saturated rubber latex having an iodine value of 0 to 120. After the treatment, a bonding method for vulcanizing and bonding with a rubber composition has been proposed. Further, the publication discloses a heat-resistant conveyor belt in which a composite obtained by laminating a rubber composition made of EPDM and a canvas is covered with a cover rubber, wherein the rubber composition and the canvas are bonded by the bonding method. A heat resistant conveyor belt is disclosed.

[0005] However, the above-mentioned bonding method can be applied to a belt rotating at a relatively low speed such as a conveyor belt, but it is required to withstand a high load and to have a high degree of bending fatigue resistance. However, there are problems such as insufficient strength of the rubber composition itself and insufficient adhesion between the rubber composition and the fiber material.

[0006] International Publication WO 96/13544 discloses ethylene-α-olefin elastomers and α, β-olefin elastomers.
An elastomer composition containing a metal salt of an unsaturated organic acid and cured by a free radical generator is disclosed. Further, the publication describes a belt in which a belt base portion is prepared from the elastomer composition.

[0007] Specifically, in the embodiments of the above publication, EPD
In preparing a belt by compounding an elastomer composition containing M and zinc methacrylate with a polyester woven sheet, the polyester woven sheet was previously converted to a vinylpyridine-styrene-butadiene terpolymer rubber latex and resorcinol-formaldehyde. It describes a method of coating with a treatment liquid containing a condensate and then vulcanizing and bonding to an elastomer composition.

[0008] However, vinyl pyridine-
When a treatment liquid containing a styrene-butadiene terpolymer rubber latex is used, the adhesive strength between the elastomer composition and the fiber material is significantly reduced when the belt is exposed to a high-temperature atmosphere for a long time. There was found. As a result, according to the method described in the publication, a decrease in adhesiveness due to heat load is caused, so that a belt having excellent durability cannot be obtained.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rubber composition containing an ethylene-α-olefin copolymer rubber such as an ethylene-propylene copolymer rubber or an ethylene-propylene-diene terpolymer. A composite with a fiber material, having excellent adhesion between the rubber composition and the fiber material,
An object of the present invention is to provide a composite which exhibits high heat resistance and bending fatigue resistance, has a large tensile stress, does not cause a decrease in adhesiveness due to a heat load, and has excellent durability, and a method for producing the same.

The present inventors have conducted intensive studies to achieve the above object, and as a result, have used a rubber composition obtained by blending a metal salt of an ethylenically unsaturated carboxylic acid with an ethylene-α-olefin copolymer rubber, and When the rubber composition and the fiber material are vulcanized and bonded, the fiber material is preliminarily replaced with an iodine value of 8;
It has been found that the above object can be achieved by coating with a treating solution containing a nitrile group-containing highly saturated copolymer rubber latex of 0 or less and a resorcinol-formaldehyde precondensate. The vulcanization bonding is preferably performed in the presence of an organic peroxide. The composite of the present invention can be suitably applied to uses such as belts and hoses. The present invention has been completed based on these findings.

[0011]

Thus, according to the present invention, there are provided (a) 100 parts by weight of an ethylene-α-olefin copolymer rubber, and (b) 100 parts by weight of an ethylene-α-olefin copolymer rubber. Rubber composition (A) containing 10 to 80 parts by weight of a metal salt of an ethylenically unsaturated carboxylic acid, a nitrile group-containing highly saturated copolymer rubber latex having an iodine value of 80 or less, and resorcinol-formaldehyde A composite comprising a fiber material (B) coated with a treatment liquid containing an initial condensate, wherein the rubber composition and the fiber material are vulcanized and adhered.

Further, according to the present invention, 10 parts by weight of (a) 100 parts by weight of ethylene-α-olefin copolymer rubber and (b) 100 parts by weight of ethylene-α-olefin copolymer rubber, A rubber composition (A) containing 80 parts by weight of a metal salt of an ethylenically unsaturated carboxylic acid, a nitrile group-containing highly saturated copolymer rubber latex having an iodine value of 80 or less, and a resorcinol-formaldehyde precondensate. The present invention provides a method for producing a composite in which a fiber material (B) coated with a treatment liquid to be subjected to vulcanization bonding is performed in the presence of an organic peroxide.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Ethylene-α-olefin copolymer rubber The ethylene-α-olefin copolymer rubber used in the present invention is a rubber obtained by copolymerizing ethylene and α-olefin, and has a non-conjugated diene as the third component. May be copolymerized. Examples of the α-olefin include α-olefins having 3 to 8 carbon atoms such as propylene, 1-butene, 1-pentene, 1-hexene, and 1-octene. These α-olefins can be used alone or in combination of two or more.

Examples of the non-conjugated diene include dicyclopentadiene, methyltetrahydroindene, vinylnorbornene, 5-ethylidene-2-norbornene,
4-hexadiene and the like can be mentioned. Among these, 5-ethylidene-2-norbornene and dicyclopentadiene are preferred.

In the ethylene-α-olefin copolymer rubber, the ethylene unit is usually 35 to 80% by weight,
The olefin unit is usually 20 to 65% by weight, and the non-conjugated diene unit is usually 20% by weight or less. Ethylene-α-
Among olefin copolymer rubbers, ethylene-propylene copolymer rubber (EPM), ethylene-propylene-non-conjugated diene copolymer rubber (EPDM), and a mixture thereof are preferable.

The EPM preferably has 40 ethylene units.
７５75 wt%, more preferably 45-70 wt%, and the propylene unit content is preferably 25-60 wt%, more preferably 30-55 wt%. EPD
M is preferably from 44 to 75% by weight, more preferably from 49 to 65% by weight of ethylene units, and preferably from 24 to 55% by weight, more preferably from 34 to 55% by weight of propylene units.
It is desirable that the content is 50% by weight and the non-conjugated diene unit is preferably 1 to 12% by weight. Mooney viscosity of ethylene-α-olefin copolymer rubber (ML _{1 + 4} , 100 ° C)
Is usually 15 to 120.

2. Metal salt of ethylenically unsaturated carboxylic acid The metal salt of ethylenically unsaturated carboxylic acid used in the present invention is, for example, an unsaturated monocarboxylic acid such as acrylic acid, methacrylic acid, crotonic acid, and 3-butenoic acid; Unsaturated dicarboxylic acids such as acid, fumaric acid and itaconic acid; monoesters of unsaturated dicarboxylic acids such as monomethyl maleate, monoethyl maleate and monoethyl itaconate; unsaturated polycarboxylic acids other than the above and at least monovalent free And at least one metal salt of an ethylenically unsaturated carboxylic acid such as an ester of an unsaturated polycarboxylic acid leaving a carboxyl group.

The metal is not particularly limited as long as it forms a salt with the ethylenically unsaturated carboxylic acid, but zinc, magnesium, calcium and aluminum are particularly suitable.

These metal salts of ethylenically unsaturated carboxylic acids may be incorporated as the metal salts.
oxides of the metal and the ethylenically unsaturated carboxylic acid α- olefin copolymer rubber, and adding a metal compound such as hydroxide or carbonate, is reacted with the rubber during the preparation of the rubber composition, in A method of generating a metal salt in situ may be used. However, when these compounds or metal salts are used, it is preferable to remove the coarse particles, that is, to classify the particles with an air classifier or the like to reduce the content of particles having a particle diameter of 20 μm or more to 5% or less.

Among these metal salts of ethylenically unsaturated carboxylic acids, zinc methacrylate is particularly preferred in view of physical properties and availability. When zinc methacrylate is used, a zinc compound such as zinc oxide or zinc carbonate is reacted in an amount of 0.5 to 3.2 mol, preferably 0.6 to 2 mol, per 1 mol of methacrylic acid. Those obtained by the above method are preferred.

The proportion of the metal salt of the ethylenically unsaturated carboxylic acid used is defined as ethylene-α-olefin copolymer rubber 10
10 to 80 parts by weight, preferably 15 parts by weight, per 0 parts by weight
７５75 parts by weight, more preferably 20-70 parts by weight. If the proportion of the metal salt of the ethylenically unsaturated carboxylic acid is too small, sufficient strength cannot be obtained, and if it is too large, kneading becomes difficult.

3. Crosslinking Agent In the present invention, it is preferable to use an organic peroxide as a crosslinking agent for vulcanizing a rubber composition containing an ethylene-α-olefin copolymer rubber. Specific examples of the organic peroxide include, for example, dicumyl peroxide, di-t-butyl peroxide, t-
Butylcumyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (benzoylperoxy) hexane, , 5-Dimethyl-2,5-mono (t-butylperoxy) -hexane,
α, α′-bis (t-butylperoxy-m-isopropyl) benzene and the like.

The proportion of the organic peroxide used is ethylene-α
-It is usually 0.2 to 10 parts by weight, preferably 0.4 to 8 parts by weight, based on 100 parts by weight of the olefin copolymer rubber. If the use ratio is too small or too large, it is difficult to obtain a high-strength composite.

4. Other additives In the rubber composition of the present invention, as other additives, reinforcing agents such as carbon black and silica; calcium carbonate,
Fillers such as talc; crosslinking aids such as triallyl isocyanurate, trimethylolpropane trimethacrylate, and m-phenylene bismaleimide; stabilizers, coloring agents, and the like can be added as necessary.

[5] Preparation of Rubber Composition The rubber composition is composed of an ethylene-α-olefin copolymer rubber, a metal salt of an ethylenically unsaturated carboxylic acid (or a metal compound with an ethylenically unsaturated carboxylic acid), a crosslinking agent, and other additives. Such components can be prepared by kneading using a mixer such as a roll, a Banbury or a kneader.

In the kneading of each component, as a first step, an ethylene-α-olefin copolymer rubber and a metal salt of an ethylenically unsaturated carboxylic acid (or an ethylenically unsaturated carboxylic acid and a metal compound) are mixed for 100 to 100 minutes. Kneading at a high temperature of 130 ° C., and then, as a second step, lowering the temperature,
And other additives are desirably kneaded. The temperature in the second step is a temperature at which the crosslinking agent is not activated, but is usually 70 ° C. or lower, preferably 60 ° C. or lower.

6. Nitrile Group-Containing Highly Saturated Copolymer Rubber Latex The nitrile group-containing highly saturated copolymer rubber latex used in the present invention is obtained by copolymerizing an α, β-ethylenically unsaturated nitrile monomer with another monomer. Latex of a nitrile group-containing highly saturated copolymer rubber obtained by the reaction, or a nitrile group-containing unsaturated copolymer obtained by copolymerizing an α, β-ethylenically unsaturated nitrile monomer with another monomer. This is a latex obtained by subjecting a polymer rubber to a hydrogenation reaction to obtain a nitrile group-containing highly saturated copolymer rubber. Usually, a nitrile group-containing unsaturated copolymer rubber latex obtained by emulsion polymerization of an ethylenically unsaturated nitrile monomer and another monomer is subjected to a hydrogenation reaction in a latex state to obtain a nitrile group-containing unsaturated copolymer rubber latex. A method of obtaining a highly saturated copolymer rubber latex is employed.

The method of hydrogenation is not particularly limited.
For example, the method described in JP-A-2-178305 and JP-A-3-167239 using a palladium compound as a hydrogenation catalyst can be exemplified. Also, Japanese Patent Application Laid-Open No. 59-1 using hydrazine and peroxide for hydrogenation
No. 61415, JP-A-4-505176, W
The method described in O00 / 09576 can also be adopted.

The iodine value of the nitrile group-containing highly saturated copolymer rubber is 80 or less, preferably 60 or less, more preferably 40 or less (0 to 40). When the fiber material is coated with a treatment solution (adhesive treatment solution) containing a nitrile group-containing highly saturated copolymer rubber latex having an iodine value that is too large, the heat resistance of the composite comprising the rubber composition and the fiber material becomes poor. Be impaired. The iodine value is an index indicating the degree of unsaturation of carbon-carbon bonds in rubber molecules, and is a numerical value expressing the amount of iodine that can be added to 100 g of rubber in grams.

Other monomers to be copolymerized with the α, β-ethylenically unsaturated nitrile monomer include conjugated diene monomers, non-conjugated diene monomers, and α-olefins. These monomers can be used alone or in combination of two or more. When an α, β-ethylenically unsaturated nitrile monomer and a conjugated diene monomer are copolymerized, a copolymer rubber having an excessively high iodine value can be obtained in many cases. The iodine value may be lowered by hydrogenating carbon-carbon unsaturated bonds in the polymerized rubber.

Examples of the α, β-ethylenically unsaturated nitrile monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile and the like. Among these, acrylonitrile is particularly preferred. These can be used alone or in combination of two or more. The content of the α, β-ethylenically unsaturated nitrile monomer unit in the nitrile group-containing highly saturated copolymer rubber is usually from 10 to 60% by weight, preferably from 10 to 55% by weight, more preferably from 10 to 55% by weight. 50% by weight.

As the conjugated diene monomer, for example, 1,
Examples thereof include 3-butadiene, 2,3-dimethylbutadiene, isoprene, and 1,3-pentadiene. Among these, 1,3-butadiene is particularly preferred. A nitrile group-containing highly saturated copolymer rubber copolymerizes an α, β-ethylenically unsaturated nitrile monomer, a conjugated diene monomer, and other copolymerizable monomers as necessary, If the copolymer is hydrogenated as required, the content of the conjugated diene monomer unit in the copolymer is preferably 30.
%, More preferably 40 to 90% by weight, and even more preferably 50 to 90% by weight.

As the non-conjugated diene monomer, those having 5 to 12 carbon atoms are preferable, and 1,4-pentadiene,
Examples thereof include 1,4-hexadiene, vinylnorbornene, and dicyclopentadiene. As the α-olefin, those having 2 to 12 carbon atoms are preferable, and ethylene, propylene, 1-butene, 4-methyl-1-pentene, l
-Hexene, 1-octene and the like.

Other monomers copolymerizable with the α, β-ethylenically unsaturated nitrile monomer include α, β-ethylenically unsaturated nitrile monomers.
Ethylenically unsaturated carboxylic acid esters, aromatic vinyl monomers, fluorine-containing vinyl monomers, α, β-ethylenically unsaturated monocarboxylic acids, α, β-ethylenically unsaturated dicarboxylic acids and their anhydrides Products, copolymerizable antioxidants and the like. Each of these monomers alone,
Alternatively, two or more kinds can be used in combination.

Examples of the α, β-ethylenically unsaturated carboxylic acid esters include those having 1 to 1 carbon atoms such as methyl acrylate, ethyl acrylate, n-dodecyl acrylate, methyl methacrylate and ethyl methacrylate.
Acrylates and methacrylates having an alkyl group of 8; acrylates and methacrylates having an alkoxyalkyl group having 2 to 12 carbon atoms such as methoxymethyl acrylate and methoxyethyl methacrylate; and α-cyanoethyl acrylate, β-cyanoethyl acrylate, cyanobutyl methacrylate and the like. 2-12 carbon atoms
Acrylates and methacrylates having a cyanoalkyl group; acrylates and methacrylates having a hydroxyalkyl group such as 2-hydroxyethyl acrylate and hydroxypropyl acrylate; monoethyl maleate, dimethyl maleate, dimethyl fumarate, dimethyl itaconate, diethyl itaconate, Α, β-ethylenically unsaturated dicarboxylic acid monoalkyl ester such as di-n-butyl itaconate and α, β-ethylenically unsaturated dicarboxylic acid dialkyl ester; amino group-containing α such as dimethylaminomethyl acrylate and diethylaminoethyl acrylate , Β-ethylenically unsaturated carboxylic acid ester monomer; having a fluoroalkyl group such as trifluoroethyl acrylate and tetrafluoropropyl methacrylate Acrylate and methacrylate; fluorobenzyl acrylate, and fluorine-substituted benzyl acrylates and fluoro-substituted benzyl methacrylates, such as fluorobenzyl methacrylate.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, vinylpyridine and the like. Examples of the fluorine-containing vinyl monomer include fluoroethyl vinyl ether, fluoropropyl vinyl ether, o-trifluoromethylstyrene, vinyl pentafluorobenzoate, difluoroethylene, and tetrafluoroethylene. Examples of the α, β-ethylenically unsaturated monocarboxylic acid include acrylic acid and methacrylic acid. Examples of the α, β-ethylenically unsaturated dicarboxylic acid include itaconic acid, fumaric acid, and maleic acid. Examples of the anhydride of α, β-ethylenically unsaturated dicarboxylic acid include maleic anhydride. Examples of the copolymerizable antioxidant include N- (4-anilinophenyl) acrylamide and N- (4-anilinophenyl)
Methacrylamide, N- (4-anilinophenyl) cinnamamide, N- (4-anilinophenyl) crotonamide, N-phenyl-4- (3-vinylbenzyloxy) aniline, N-phenyl-4- (4- Vinylbenzyloxy) aniline and the like.

Examples of the nitrile group-containing highly saturated copolymer rubber latex include those obtained by hydrogenating the conjugated diene unit of an unsaturated nitrile-conjugated diene copolymer rubber and those obtained by unsaturated nitrile-conjugated diene-α, β-ethylenically unsaturated rubber. A hydrogenated conjugated diene unit of a saturated monomer terpolymer is preferred.

7. Resorcinol-formaldehyde precondensate The resorcinol-formaldehyde precondensate (sometimes simply referred to as "resorcinol-formaldehyde resin") used in the present invention is not particularly limited.
No. 5,142,635.
These include a resol type obtained by dissolving resorcinol and an aqueous formaldehyde solution in water and reacting with an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide as a catalyst, or an acidic compound such as oxalic acid or hydrochloric acid as a catalyst. There is a novolak type obtained by reacting as above, but either type can be used.

Examples of the novolak resin include Sumikanol 700 (manufactured by Sumitomo Chemical Co., Ltd.) and Adha RF (manufactured by Hodogaya Chemical Co., Ltd.). When using these novolak-type resorcinol-formaldehyde resins,
A novolak resin is added to water to which a small amount of sodium hydroxide or ammonia water has been added to prepare an aqueous solution. Also,
When using these novolak resorcinol-formaldehyde resins, a formaldehyde aqueous solution may be added as necessary.

The resorcinol-formaldehyde precondensate used in the present invention has a molar ratio of resorcinol to formaldehyde of 1: 1 to 1 from the viewpoint of the water resistance of the composite and the adhesiveness to a fiber material such as canvas. 1: 3 is preferred,
1: 1.2 to 1: 2 is more preferable.

8. Treatment liquid (adhesive) In the present invention, when compounding the rubber composition and the fiber material, a treatment liquid containing a specific component is used in order to enhance the adhesiveness between the two. This treatment liquid may be referred to as an adhesive or an adhesive treatment liquid. Specifically, the treatment liquid contains a nitrile group-containing highly saturated copolymer rubber latex having an iodine value of 80 or less and a resorcinol-formaldehyde precondensate as main components.

From the viewpoint of the water resistance of the composite and the adhesiveness to the fiber material, the treatment liquid of the present invention is prepared based on 100 parts by weight of the solid content of the nitrile group-containing highly saturated copolymer rubber latex based on the resorcinol-formaldehyde initial concentration. The condensate is preferably blended in a dry weight ratio of 5 to 30 parts by weight, more preferably 7 to 15 parts by weight.

To the treatment liquid, a crosslinking agent such as zinc oxide, zinc peroxide, sulfur, etc., a crosslinking accelerator, an antioxidant, an aqueous dispersion of carbon black, etc. are added within a range not to impair the object of the present invention. You may. The amount of carbon black used is 5 to 5 parts by weight of the solid content of the nitrile group-containing highly saturated copolymer rubber latex from the viewpoint of the adhesion between the rubber composition and the fiber material, and the abrasion of the fiber material. 20 parts by weight,
Preferably it is 7 to 15 parts by weight. The particle size of the carbon black is preferably 0.02 to 0.04 μm, and the grade is I
SAF, HAF and FEF grades are preferred.

The treatment liquid of the present invention contains a styrene-butadiene copolymer rubber latex, a modified styrene-butadiene copolymer rubber latex, an acrylonitrile-butadiene copolymer rubber latex, a modified rubber latex as long as the effects of the present invention are not impaired. Acrylonitrile-butadiene copolymer rubber latex, chloroprene rubber latex, chlorosulfonated polyethylene latex, acrylate latex, or natural rubber latex may be added.

9. Fiber material The fiber material used in the present invention is not particularly limited, for example, cotton, vinylon fiber, rayon fiber, nylon fiber,
Examples thereof include polyester fibers and aramid fibers. These fiber materials include staples, filaments,
Used in the form of cords, ropes, woven fabrics, non-woven fabrics and the like.

10. Composite and Method for Producing the Same The composite of the present invention is obtained by using the above-mentioned treatment solution by mixing a rubber composition containing an ethylene-α-olefin copolymer rubber and a metal salt of an ethylenically unsaturated carboxylic acid and a fiber material with the above-described treatment liquid. Vulcanized.

In the production method of the present invention, first, the fiber material is coated with a treatment liquid containing a nitrile group-containing highly saturated copolymer rubber latex having an iodine value of 80 or less and a resorcinol-formaldehyde precondensate. The method of coating the fiber material with the treatment liquid is not particularly limited, and, similarly to a general tire cord, a nitrile group-containing highly saturated copolymer rubber latex having an iodine value of 80 or less and a resorcinol-formaldehyde precondensate. It can be carried out by using the contained aqueous solution or aqueous dispersion as the treatment liquid, immersing the fiber material in the treatment liquid, drying, and performing heat treatment.

For example, the fibrous material, preferably having a viscosity of 10
After being immersed in a treatment solution whose concentration has been adjusted to 20 cps, it is dried to remove water. Usually, from the viewpoint of the adhesiveness between the rubber composition and the fiber material, the solid content of the treatment liquid is 1 to 15% by weight based on the weight of the fiber material,
Preferably it is 2 to 10% by weight, more preferably 3 to 6% by weight. The drying conditions are not particularly limited, and are usually 10
A drying temperature of 0 to 180 ° C and a drying time of about 0.5 to 10 minutes are employed. Further, heat treatment is performed to enhance the adhesiveness between the rubber composition and the fiber material. As heat treatment conditions, usually, a heat treatment temperature of 150 to 280 ° C,
A heat treatment time of about 30 to 120 seconds is employed.

Depending on the type of the fiber material, the fiber material is immersed in an isocyanate compound solution, an aqueous solution of an isocyanate compound, an epoxy compound solution or an aqueous dispersion of an epoxy compound, etc., prior to immersion in the treatment liquid, and then dried. Then, it is sometimes desirable to enhance the adhesiveness by fixing an isocyanate compound or an epoxy compound to the fiber material. The drying temperature in this case may be any temperature and time sufficient for the isocyanate compound or the epoxy compound to be fixed to the fiber material and for drying a solvent such as water, and is usually 120 to 200 ° C. for several tens of seconds to several minutes. Done. The amount of these compounds attached to the fibers is preferably in the range of 0.05 to 1.0% by weight based on the weight of the fiber material. The amount of these compounds attached to the fiber material can be controlled by adjusting the concentration of the solution or aqueous dispersion, adjusting the immersion time, and repeating the immersion.

The isocyanate compound is not particularly restricted but includes diphenylmethane diisocyanate, tolylene diisocyanate, triphenylmethane diisocyanate,
Examples thereof include polymethylene polyphenyl isocyanate. Examples of the epoxy compound include ethylene glycol diglycidyl ether, propylene glycol glycidyl ether, glycerol polyglycidyl ether, and sorbitol polyglycidyl ether.

After coating the fiber material with the treatment liquid, the rubber composition and the fiber material are brought into close contact with each other and vulcanized. More specifically, for example, a method of laminating an unvulcanized rubber sheet formed from a rubber composition and a fiber material and press-vulcanizing the material can be mentioned. As the vulcanization conditions, ordinary vulcanization conditions adopted for ethylene-α-olefin copolymer rubber can be applied. The vulcanization temperature can be appropriately determined according to the decomposition temperature of the crosslinking agent (organic peroxide) used.

The composite of the present invention can be used as it is as a belt or a hose. However, if necessary, additional layers or parts such as covering with a cover rubber can be attached. Also, the shape is not particularly limited, and products having various shapes such as a V-belt and a toothed belt can be obtained. Since the composite of the present invention retains excellent adhesiveness even after prolonged bending fatigue, it is suitable as a V-belt or V-ribbed belt for automobiles.

[0053]

The present invention will be described below in more detail with reference to Production Examples, Examples and Comparative Examples. The measuring method of the physical properties is as follows. (1) Peeling Adhesive Strength The initial adhesive strength and the heat resistant adhesive strength of the adhesive test piece were measured using an Instron-type Tensilon at a peeling rate of 50 mm / min. The heat resistance of the adhesive test piece was 140 ° C.
Is the adhesive strength after heat aging for 168 hours. The measurement temperature was 25 ° C. in each case. The unit is N / 25
mm.

(2) Bending fatigue test Using a bending fatigue tester specified in JIS K-6260, the ratio of the moving distance of the device to the maximum distance of the gripper was set to 0.5, and an adhesive test piece was attached. And after 100,000 times of fatigue, the adhesive strength was measured. The measurement of the peel adhesive strength after bending fatigue was performed on an untreated adhesive test piece and an adhesive test piece after heat-aging the adhesive test piece at 140 ° C. for 168 hours.

(3) Rubber Adhesion Rate The rubber adhesion rate was measured by peeling off the adhesive test piece and visually determining the area fraction of the adhered rubber adhering to the polyester fiber cord side. The indication is 10% from 0 to 100%
I went in steps.

Production Example 1 Preparation Example of Latex In a pressure-resistant bottle, 240 parts by weight of water, 2.5 parts by weight of sodium alkylbenzenesulfonate adjusted to pH 9, 35 parts by weight of acrylonitrile, and t-dodecylmercaptan 0.1 part as a molecular weight regulator. 4 parts by weight, butadiene 65 parts by weight, and ammonium persulfate 0.25 as a polymerization initiator
The polymerization reaction was carried out with stirring at a reaction temperature of 50 ° C. for 20 hours to obtain a nitrile group-containing unsaturated polymer rubber latex.

Next, 400 ml of a nitrile group-containing unsaturated polymer rubber latex adjusted to a total solid content of 12% by weight was prepared.
(Total solid content: 48 g) was charged into an autoclave equipped with a stirrer. After the inside of the autoclave was replaced with nitrogen, 100 mg of palladium acetate as a hydrogenation catalyst was dissolved in 240 ml of water to which 4-fold molar amount of nitric acid was added and added. After replacing the inside of the system twice with hydrogen gas, pressurize the hydrogen gas to 30 atm.
The reaction was performed at 0 ° C. for 6 hours. After depressurization, the mixture was concentrated using an evaporator until the solid content concentration became 40% by weight to obtain a nitrile group-containing highly saturated copolymer rubber latex (HNBR latex) having an iodine value of 30.

[Production Example 2] Preparation example of treatment liquid 11.0 parts by weight of resorcinol, 12.2 parts by weight of an aqueous formaldehyde solution (37% by weight), and 3.0 parts by weight of an aqueous solution of sodium hydroxide (10% by weight) were distilled. 193.8 water
It was dissolved in parts by weight and reacted at 25 ° C. for 6 hours with stirring.
A latex (solid content of 40%) was added to the obtained liquid (RF liquid).
25% by weight) and 107.5 parts by weight of distilled water were added, and the mixture was aged at 25 ° C. for 20 hours with stirring. To the obtained liquid, Vulkabond E [2,6-bis (2,4-dihydroxyphenylmethyl) -4-chlorophenol,
20% by weight] to obtain a final treatment liquid.

A treatment liquid (HNBR) using a hydrogenated acrylonitrile-butadiene copolymer rubber latex (Production Example 1) as a latex, and a styrene-butadiene-
A treatment liquid (VP) using vinylpyridine terpolymer latex (manufactured by Zeon Corporation) was prepared. Table 1 shows the composition of each processing solution.

[0060]

[Table 1]

Footnotes (1) The RF solution was aged at 25 ° C. for 6 hours. (2) The RFL solution was aged at 25 ° C. for 20 hours, and then Vulkabond E was added to obtain a treatment solution (dip solution). (* 1) Hydrogenated acrylonitrile-butadiene copolymer rubber latex, iodine value = 30 (* 2) Styrene-butadiene-vinylpyridine ternary copolymer latex (manufactured by Zeon Corporation) (* 3) 2,6-bis (2,4-dihydroxyphenylmethyl) -4-chlorophenol

[Production Example 3] Preparation Example of Rubber Compound According to the compounding recipe shown in Table 2, first, EPM or EP
The kneading of DM with zinc oxide and a zinc salt of methacrylic acid or methacrylic acid (zinc dimethacrylate) is carried out on a roll having a roll surface temperature of 120 ° C., and then on a roll having a roll surface temperature of 50 ° C. Knead the compounding agent to about 2.
An unvulcanized rubber sheet having a thickness of 5 mm was prepared.

[0063]

[Table 2]

Footnotes (1) EPM: ethylene-propylene copolymer rubber, manufactured by Mitsui Chemicals, Inc., trade name: Mitsui EPT0045 (2) EPDM-1: ethylene-propylene-diene terpolymer rubber, manufactured by Mitsui Chemicals, Inc. Product name Mitsui EPT3
070 (3) EPDM-2: ethylene-propylene-diene terpolymer rubber, manufactured by Mitsui Chemicals, Inc., trade name: Mitsui EPT4
070 (4) EPDM-3: ethylene-propylene-diene terpolymer rubber, manufactured by Mitsui Chemicals, Inc., trade name: Mitsui EPT1
070 (5) Trade name Zinc Hua No. 1, manufactured by Shodo Chemical Co., Ltd. (6) Trade name manufactured by Saret 634, manufactured by Sartomer Co., Ltd. (7) Trade name manufactured by Sampar 150, manufactured by Sun Oil Co. (8) Trade name: Nocrack 224, 1, 2 -Dihydro-
2,2,4-trimethylquinoline, manufactured by Ouchi Shinko Co., Ltd. (9) Trade name: VALQUAP 40KE, α, α-bis (t
-Butyl peroxy) diisopropylbenzene, manufactured by Hercules

[Production Example 4] Preparation Example of Adhesion Test Specimen Using a Ritzler type dip machine, a polyester fiber cord (made of polyethylene terephthalate, 1500)
d / 2 × 3) in an isocyanate treatment liquid,
The solvent was removed at 10 ° C. for 2 minutes, then at 220 ° C.
For 30 seconds. As an isocyanate treatment liquid, a mixture of 10 parts by weight of polymethylene polyphenylisocyanate (PAPI-135, manufactured by Mitsubishi Chemical Dow) and 100 parts by weight of toluene was used.

Next, the polyester fiber cord was immersed in the treatment solution shown in Table 1, dried at 110 ° C. for 2 minutes, and then heat-treated at 240 ° C. for 30 seconds to obtain a polyester fiber coated with an adhesive. Code (processing code) was obtained.

The obtained treatment cords are arranged on an unvulcanized rubber sheet having a length of 155 mm and a width of 25 mm so as to have a width of 25 mm, and then a test piece for a flex crack test according to JIS K-6260 is prepared. Using a mold, press pressure 5M
press vulcanization at a press temperature of 160 ° C. for 30 minutes,
An adhesion test piece (composite) of the polyester fiber cord and the rubber composition was obtained.

Examples 1 to 6 EPM or EPD containing zinc salt of methacrylic acid (zinc dimethacrylate)
M (rubber compounds A, B, D, E, G, H), a treatment liquid comprising a resorcinol-formaldehyde precondensate and a nitrile group-containing highly saturated copolymer rubber latex (HNBR)
Using a polyester fiber cord coated with
An adhesion test piece was prepared. About the obtained adhesion test piece,
The adhesive strength after heat aging at room temperature (25 ° C.) and 140 ° C. for 168 hours was measured using an Instron type Tensilon at a peeling speed of 50 mm / min. Further, the adhesive test pieces were heat-aged at room temperature (25 ° C.) and 140 ° C. for 168 hours, and then subjected to a bending fatigue test, and the peel adhesion after the fatigue test was measured by the same method. Table 3 shows the measurement results.

[Comparative Examples 1 to 5] Examples 1 to 6 were conducted using a treatment liquid (VP) containing a vinylpyridine-styrene-butadiene terpolymer rubber latex as a treatment liquid.
Similarly, an adhesion test piece was prepared, and the peel adhesion was measured (Comparative Examples 1, 2, and 4). Further, using a rubber composition containing no zinc salt of methacrylic acid, adhesion test pieces were prepared in the same manner as in Examples 1 to 6, and peel adhesion was measured (Comparative Examples 3 and 5).
Table 3 shows the results.

[0070]

[Table 3]

As is evident from the results in Table 3, a rubber composition containing EPM or EPDM containing a metal salt of an ethylenically unsaturated carboxylic acid was used as a rubber component, and the rubber composition was prepared using a nitrile group-containing rubber composition. It can be seen that when the polyester fiber coated with a treatment solution containing a highly saturated copolymer rubber latex and a resorcinol-formaldehyde precondensate is treated with the polyester fiber, the adhesion between the two is excellent (Examples 1 to 6). Further, it can be seen that the adhesiveness after bending fatigue is excellent.

On the other hand, when a polyester fiber coated with a treatment liquid containing a styrene-butadiene-vinylpyridine terpolymer latex and a resorcinol-formaldehyde precondensate is used, the initial adhesive strength is decent. It can be seen that the heat resistance is inferior (Comparative Examples 1, 2, and 4). Further, using a rubber composition not containing a metal salt of an ethylenically unsaturated carboxylic acid, a polyester fiber coated with a treatment solution containing a nitrile group-containing highly saturated copolymer rubber latex and a resorcinol-formaldehyde precondensate, In the case of a composite, the adhesion between the two shows a moderate adhesive strength in both the initial adhesion and the heat-resistant adhesion, but the initial adhesion is lower than when a rubber composition containing a metal salt of an ethylenically unsaturated carboxylic acid is used. It can be seen that both the heat resistance and the heat resistance are inferior (Comparative Examples 3, 5).

[0073]

According to the present invention, a rubber composition containing an ethylene-α-olefin copolymer rubber, such as an ethylene-propylene copolymer rubber or an ethylene-propylene-diene terpolymer, is mixed with a fiber material. A composite, having excellent adhesion between the rubber composition and the fiber material, exhibiting high heat resistance and bending fatigue resistance, having a large tensile stress, and not causing a decrease in adhesion due to heat load. And a composite having excellent durability and a method for producing the same.

Continued on front page F term (reference) 4F072 AA01 AA02 AA04 AA07 AB03 AB04 AB05 AB06 AB25 AB28 AB29 AC10 AD04 AE01 AE02 AF17 AG22 AJ02 AJ03 AK05 AK14 AL16 AL18 AL19 4F205 AA45 AD16 AD34 AG08 AG16 AG17 HA08 HA22 HA33 HA46 4J002 BB051 BB151 BB231 EG016 EK028 EK058 EK068 FA047 FB267 FD148 GN00

Claims (2)

[Claims] 1 to 80 parts by weight per 100 parts by weight of (a) 100 parts by weight of ethylene-α-olefin copolymer rubber and (b) 100 parts by weight of ethylene-α-olefin copolymer rubber.
A rubber composition (A) containing parts by weight of a metal salt of an ethylenically unsaturated carboxylic acid, a nitrile group-containing highly saturated copolymer rubber latex having an iodine value of 80 or less, and a resorcinol-formaldehyde precondensate. A composite comprising a fiber material (B) coated with a treatment liquid, wherein the rubber composition and the fiber material are vulcanized and adhered. 2. 10 to 80 parts by weight of (a) 100 parts by weight of ethylene-α-olefin copolymer rubber and (b) 100 parts by weight of ethylene-α-olefin copolymer rubber.
A rubber composition (A) containing parts by weight of a metal salt of an ethylenically unsaturated carboxylic acid, a nitrile group-containing highly saturated copolymer rubber latex having an iodine value of 80 or less, and a resorcinol-formaldehyde precondensate. A method for producing a composite in which a fiber material (B) coated with a treatment liquid is vulcanized and bonded in the presence of an organic peroxide.