JP5481225B2 - Copolymer latex for adhesive - Google Patents

Description

  The present invention relates to a copolymer latex for adhesive, and more particularly to a copolymer latex for adhesive that bonds rubber and fiber.

  Conventionally, fibers such as nylon, polyester, and aramid have been used as rubber reinforcing fibers for reinforcing rubber products such as tires, belts, and hoses.

  These rubber reinforcing fibers are usually used for an adhesive copolymer latex (generally a butadiene-vinylpyridine copolymer latex or a butadiene-vinylpyridine) in order to ensure their adhesion to rubber products. Adhesive treatment using an adhesive composition (hereinafter referred to as RFL) containing a copolymer copolymer latex and other rubber latex) and a resorcin-formalin resin (hereinafter referred to as RF resin). Has been.

  In this bonding treatment, the rubber reinforcing fibers are immersed in RFL and dried, and then heat treatment is performed at a high temperature of 170 ° C. or higher for nylon fibers and 220 ° C. or higher for polyester fibers or aramid fibers.

  As such a copolymer latex for adhesive used in RFL, for example, a butadiene-vinylpyridine copolymer latex having a specific monomer composition has been proposed (see, for example, Patent Documents 1 and 2).

  Further, for example, a copolymer latex composed of a butadiene-vinylpyridine copolymer latex having a specific monomer composition and SBR having a specific monomer composition has been proposed (see, for example, Patent Documents 3, 4, and 5). .

  For example, a copolymer latex composed of copolymer particles having a specific structure has been proposed (see, for example, Patent Document 6).

  Further, for example, a copolymer latex composed of butadiene-vinylpyridine copolymer latex having two kinds of specific monomer compositions has been proposed (see, for example, Patent Document 7).

Japanese Patent Publication No. 7-78207 Japanese Patent Publication No. 8-32864 Japanese Examined Patent Publication No. 6-74401 Japanese Patent Publication No. 7-5871 JP 2007-154126 A Japanese Patent No. 3986654 JP-A-11-158289

  However, the above-described adhesion treatment has a disadvantage that the strength of the rubber reinforcing fiber is reduced by the heat treatment.

  On the other hand, in order to suppress the strength reduction of the rubber reinforcing fiber, it is considered that the heat treatment is performed at a temperature lower than the above temperature. There is a problem that.

  Moreover, even if it uses the copolymer latex for adhesives of the above-mentioned patent documents 1-7, the adhesive force of rubber | gum and rubber reinforcing fiber is suppressed, suppressing the strength reduction of the rubber reinforcing fiber by heat processing. It is difficult to improve.

  Then, the objective of this invention is providing the copolymer latex for adhesive agents which can improve the adhesive force of rubber | gum and a rubber reinforcing fiber, suppressing the strength fall of the rubber reinforcing fiber by heat processing. is there.

  In order to solve the above problems, the copolymer latex for adhesive of the present invention comprises 35 to 75% by weight of a butadiene monomer, 10 to 30% by weight of a vinylpyridine monomer, and 10 to 10% of a styrene monomer. Copolymer latex (A) obtained by emulsion polymerization of a monomer composition (a) containing 55% by weight, 50 to 90% by weight (in terms of solid content), 3 to 25% by weight of a butadiene monomer, Contains 0 to 5% by weight of a vinylpyridine monomer, 55 to 97% by weight of a styrene monomer, and 0 to 20% by weight of another copolymerizable monomer. It is characterized by containing 10 to 50% by weight (in terms of solid content) of a copolymer latex (B) obtained by emulsion polymerization of a monomer composition (b) containing no body.

  Moreover, as for the copolymer latex for adhesives of this invention, it is suitable that the said monomer composition (b) contains 0 to 3 weight% of vinyl pyridine-type monomers.

  According to the copolymer latex for adhesive of the present invention, the adhesive force between rubber and rubber reinforcing fiber can be improved while suppressing the strength reduction of the rubber reinforcing fiber due to heat treatment.

  The adhesive copolymer latex of the present invention contains a copolymer latex (A) and a copolymer latex (B).

  The copolymer latex (A) is obtained by emulsion polymerization of a monomer composition (a) containing a butadiene monomer, a vinylpyridine monomer and a styrene monomer.

  Examples of the butadiene monomer include 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, and preferably 1,3-butadiene. Is mentioned. These butadiene monomers can be used alone or in combination of two or more.

  Examples of vinylpyridine monomers include 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine, and preferably 2-vinylpyridine. These vinylpyridine monomers can be used alone or in combination of two or more.

  Examples of the styrene monomer include styrene, α-methylstyrene, monochlorostyrene, and preferably styrene. These styrenic monomers can be used alone or in combination of two or more.

  In the monomer composition (a), the butadiene monomer is 35 to 75% by weight, preferably 40 to 70% by weight, and the vinylpyridine monomer is 10 to 30% by weight, preferably 13%. It contains ˜25 wt% and styrene monomer in an amount of 10 to 55 wt%, preferably 15 to 50 wt%.

  When the blending ratio of the butadiene monomer is less than 35% by weight, the initial adhesive strength is lowered, and when it exceeds 75% by weight, the cord strength and the heat resistant adhesive strength are lowered.

  When the compounding ratio of the vinylpyridine monomer is less than 10% by weight, the initial adhesive strength and the heat-resistant adhesive force are lowered, and when it exceeds 30% by weight, the initial adhesive force is lowered.

  When the blending ratio of the styrenic monomer is less than 10% by weight, the heat-resistant adhesive strength is lowered, and when it exceeds 55% by weight, the initial adhesive force and the heat-resistant adhesive force are lowered.

  The monomer composition (a) is a monomer composition which will be described later with a part of the contained monomers (butadiene monomer, vinylpyridine monomer and styrene monomer). It can be replaced with other copolymerizable monomers exemplified in (b).

  The monomer composition (a) is preferably composed of a butadiene monomer, a vinylpyridine monomer, and a styrene monomer.

  And copolymer latex (A) is obtained by carrying out emulsion polymerization of the monomer composition (a).

  In order to emulsion-polymerize the monomer composition (a), an emulsifier and a polymerization initiator are added to the monomer composition (a).

  Examples of the emulsifier include nonionic surfactants such as polyethylene glycol alkyl ester type, alkyl phenyl ether type, and alkyl ether type, such as rosin acid salt, fatty acid salt, sulfate ester salt of higher alcohol, alkylbenzene sulfonate, Anionic surfactants such as alkyl diphenyl ether sulfonates, aliphatic sulfonates, aliphatic carboxylates, sulfate esters of nonionic surfactants, formalin condensates of naphthalene sulfonate, and the like, preferably, An anionic surfactant is mentioned, More preferably, the formalin condensate of a rosinate and a naphthalenesulfonate is mentioned. One or more emulsifiers can be used.

  The polymerization initiator is a radical polymerization initiator, for example, a water-soluble polymerization initiator such as potassium persulfate, sodium persulfate, ammonium persulfate, such as cumene hydroperoxide, benzoyl peroxide, t-butyl hydroperoxide. And oil-soluble polymerization initiators such as acetyl peroxide, diisopropylbenzene hydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide. Preferably, the water-soluble polymerization initiator includes potassium persulfate, sodium persulfate, and ammonium persulfate, and the oil-soluble polymerization initiator includes cumene hydroperoxide.

  Moreover, in order to emulsion-polymerize a monomer composition (a), a reducing agent and a chain transfer agent can be added as needed.

  Examples of the reducing agent include sulfite, bisulfite, pyrosulfite, nitrite, nithionate, thiosulfate, formaldehyde sulfonate, benzaldehyde sulfonate, such as L-ascorbic acid and erythorbic acid. Carboxylic acids such as tartaric acid and citric acid and salts thereof, for example, reducing sugars such as dextrose and saccharose, and amines such as dimethylaniline and triethanolamine. Preferably, carboxylic acid and its salt are mentioned, More preferably, L-ascorbic acid and erythorbic acid are mentioned.

  Examples of the chain transfer agent include alkyl mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, and n-stearyl mercaptan, such as dimethylxanthogen disulfide, diisopropyl. Xanthogen compounds such as xanthogen disulfide, for example, thiuram compounds such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethylthiuram monosulfide, such as 2,6-di-t-butyl-4-methylphenol, styrenated phenol, etc. Phenolic compounds such as allyl compounds such as allyl alcohol, eg halogenated carbonization such as dichloromethane, dibromomethane, carbon tetrabromide Elemental compounds such as vinyl ethers such as α-benzyloxystyrene, α-benzyloxyacrylonitrile, α-benzyloxyacrylamide, such as triphenylethane, pentaphenylethane, acrolein, metaacrolein, thioglycolic acid, thiomalic acid, 2- Examples include ethylhexyl thioglycolate and α-methylstyrene dimer, preferably alkyl mercaptan, and more preferably n-octyl mercaptan and t-dodecyl mercaptan. One or two or more chain transfer agents can be used.

  The chain transfer agent is added, for example, at a ratio of, for example, 0 to 10 parts by weight, preferably 0.05 to 7 parts by weight with respect to 100 parts by weight of the monomer composition (a).

  In the emulsion polymerization, if necessary, a hydrocarbon solvent can be added. Examples of the hydrocarbon include saturated hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane, and cycloheptane, such as pentene, hexene, heptene, cyclopentene, cyclohexene, cycloheptene, 4-methylcyclohexene, and 1-methylcyclohexene. An unsaturated hydrocarbon etc. are mentioned, Preferably a cyclohexene is mentioned. Cyclohexene has a low boiling point and can be easily recovered and reused by, for example, steam distillation after polymerization, and is suitable from the viewpoint of environmental burden.

  As other additives, for example, electrolytes such as sodium hydroxide and sodium carbonate, polymerization inhibitors such as hydroquinone, polymerization accelerators, chelating agents, and the like can be added as necessary.

  Moreover, it does not specifically limit as a polymerization method, Batch polymerization, semibatch polymerization, seed polymerization, etc. can be used.

  Moreover, the addition method of various components is not particularly limited, and a batch addition method, a divided addition method, a continuous addition method, a power feed method, or the like can be used.

  In the emulsion polymerization of the copolymer latex (A), a divided addition method is preferably used.

  Specifically, in the emulsion polymerization of the copolymer latex (A), the monomer composition (a) is divided into a first-stage monomer composition (a-1) and a second-stage monomer composition (a -2), and first emulsion polymerization of the first-stage monomer composition (a-1) to obtain a pre-copolymer, followed by the second-stage in the presence of the pre-copolymer A copolymer latex (A) is obtained by emulsion polymerization of the monomer composition (a-2).

  In the first-stage monomer composition (a-1), the butadiene monomer is, for example, 10 to 60% by weight, preferably 20 to 55% by weight, and the vinylpyridine monomer is, for example, 10%. It contains -40% by weight, preferably 12-35% by weight, and a styrenic monomer, for example, 30-70% by weight, preferably 30-60% by weight.

  When the blending ratio of the butadiene-based monomer is less than 10% by weight, the initial adhesive force tends to decrease, and when it exceeds 60% by weight, the fiber strength and the heat-resistant adhesive force tend to decrease.

  When the compounding ratio of the vinylpyridine monomer is less than 10% by weight, the initial adhesive force and the heat-resistant adhesive force tend to decrease, and when it exceeds 40% by weight, the initial adhesive force tends to decrease.

  When the blending ratio of the styrenic monomer is less than 30% by weight, the cord strength tends to decrease, and when it exceeds 70% by weight, the initial adhesive force tends to decrease.

  The first-stage monomer composition (a-1) is, for example, 30 to 70 parts by weight, preferably 40 to 60 parts by weight, out of 100 parts by weight of the monomer composition (a).

  In the second-stage monomer composition (a-2), the butadiene monomer is, for example, 40 to 90% by weight, preferably 50 to 80% by weight, and the vinylpyridine monomer is, for example, 5%. -30 wt%, preferably 10-25 wt%, styrenic monomer, for example, 5-30 wt%, preferably 10-25 wt%.

  When the blending ratio of the butadiene-based monomer is less than 40% by weight, the initial adhesive force tends to decrease, and when it exceeds 90% by weight, the fiber strength and the heat-resistant adhesive force tend to decrease.

  When the blending ratio of the vinylpyridine monomer is less than 5% by weight, the initial adhesive force and the heat-resistant adhesive force tend to decrease, and when it exceeds 30% by weight, the initial adhesive force tends to decrease.

  If the blending ratio of the styrene monomer is less than 5% by weight, the fiber strength tends to decrease, and if it exceeds 30% by weight, the initial adhesive force tends to decrease.

  The second-stage monomer composition (a-2) is, for example, 30 to 70 parts by weight, preferably 40 to 60 parts by weight, out of 100 parts by weight of the monomer composition (a).

  The second-stage monomer composition (a-2) is preferably added when the polymerization conversion rate of the first-stage monomer composition (a-1) reaches 60 to 90%. The

  The copolymer latex (B) includes a butadiene monomer, a vinyl pyridine monomer, a styrene monomer, and other monomers capable of copolymerization, and contains an ethylenically unsaturated carboxylic acid. It is obtained by emulsion polymerization of the monomer composition (b) not containing a monomer.

  Examples of the butadiene monomer, the vinyl pyridine monomer, and the styrene monomer include the same monomers as those exemplified in the copolymer latex (A). The same applies to preferred monomers.

  Examples of other copolymerizable monomers include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, for example, ethylenically unsaturated carboxylic acid alkyl esters such as methyl methacrylate, ethyl acrylate, and butyl acrylate. Monomers, for example, ethylenically unsaturated carboxylic acid hydroxyalkyl ester monomers such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, amide monomers such as acrylamide and methacrylamide, etc. , One or more of each can be used.

  That is, the monomer composition (b) is composed of a butadiene monomer, a vinylpyridine monomer, a styrene monomer, and another copolymerizable monomer (however, an ethylenically unsaturated carboxylic acid). Acid monomers are excluded).

  The monomer composition (b) contains 3 to 25% by weight of butadiene monomer, preferably 4 to 20% by weight, and 0 to 5% by weight of vinylpyridine monomer (that is, vinylpyridine). The monomer may or may not be contained, and if it is contained, it is 5% by weight or less.), Preferably 0 to 4.5% by weight, more preferably 0 to 3 wt%, styrenic monomer 55 to 97 wt%, preferably 60 to 93 wt%, and other copolymerizable monomers 0 to 20 wt% (i.e. The other copolymerizable monomer may or may not be contained, and when it is contained, it is not more than 20% by weight.), Preferably 0 to 15% by weight doing.

  When the butadiene monomer is less than 3% by weight, the initial adhesive strength is lowered, and when it exceeds 25% by weight, the cord strength and the heat resistant adhesive strength are lowered.

  If the vinylpyridine monomer exceeds 5% by weight, the initial adhesive strength is lowered.

  If the styrenic monomer is less than 55% by weight, the cord strength and the heat-resistant adhesive strength are lowered. If it exceeds 97% by weight, the initial adhesive force and the heat-resistant adhesive force are lowered.

  Moreover, it does not specifically limit as a polymerization method, Batch polymerization, semibatch polymerization, seed polymerization, etc. can be used.

  Moreover, the addition method of various components is not particularly limited, and a batch addition method, a divided addition method, a continuous addition method, a power feed method, or the like can be used.

  In the emulsion polymerization of the copolymer latex (B), a batch addition method is preferably used.

  The glass transition temperature of the obtained copolymer latex (B) is, for example, 36 to 90 ° C, and preferably 40 to 85 ° C. When the glass transition temperature of the copolymer latex (B) is less than 36 ° C, the heat-resistant adhesive force tends to decrease, and when it exceeds 90 ° C, the initial adhesive force tends to decrease.

  And in order to obtain the copolymer latex for adhesives of this invention, copolymer latex (A) is 50 to 90 weight%, Preferably, 50 to 80 weight% and copolymer latex (B) are used. 10 to 50% by weight, preferably 20 to 50% by polymerization, and mixed.

  If the blending ratio of the copolymer latex (A) and the copolymer latex (B) is outside this range, the fiber strength and the heat resistant adhesive force tend to be lowered.

  Thereby, the copolymer latex for adhesives of this invention is prepared.

  The adhesive copolymer latex is preferably blended in an adhesive composition for bonding rubber and rubber reinforcing fibers.

  The rubber is not particularly limited, and examples thereof include natural rubber, SBR, NBR, chloroprene rubber, polybutadiene rubber, polyisoprene rubber, and various modified rubbers thereof. Moreover, well-known additives, such as a filler, a softening agent, a vulcanizing agent, a vulcanization accelerator, can be mix | blended with rubber | gum, for example.

  Examples of the rubber reinforcing fiber include nylon fiber, polyester fiber, and aramid fiber. Moreover, it does not specifically limit as a form of these fibers, For example, a cord, a cable, a textile fabric, a canvas, a short fiber etc. are mentioned.

  The adhesive composition is obtained by blending and mixing a copolymer latex for adhesive and a resorcin-formalin resin.

  To prepare the adhesive composition, the adhesive copolymer latex and the resorcin-formalin resin are not particularly limited, but the resorcin-- is used for 100 parts by weight (solid content) of the adhesive copolymer latex. Formalin resin is blended, for example, 5 to 100 parts by weight, preferably 5 to 90 parts by weight.

  The adhesive composition may contain isocyanate, blocked isocyanate, ethylene urea, 2,6-bis (2,4-dihydroxyphenylmethyl) -4-chlorophenol, sulfur monochloride and resorcin, as necessary. And resorcin-formalin condensate and other modified resorcin-formalin resins, polyepoxides, modified polyvinyl chloride, carbon black and other adhesion aids, fillers, crosslinking agents, vulcanizing agents, vulcanization accelerators, etc. can do.

  In order to bond the rubber and the rubber reinforcing fiber, first, the adhesive composition is processed into the rubber reinforcing fiber.

  In order to treat the adhesive composition into the rubber reinforcing fiber, the rubber reinforcing fiber is immersed in the adhesive composition using, for example, a dipping machine. Then, for example, it is dried at 100 to 150 ° C., preferably 110 to 130 ° C., for example, 80 to 200 seconds, preferably 100 to 150 seconds, and then, for example, 180 to 300 ° C., preferably 200 to 260 Baking is performed at a temperature of, for example, 30 to 100 seconds, preferably 50 to 80 seconds.

  After the treatment, when the rubber is brought into contact with the rubber reinforcing fiber treated with the adhesive composition and the rubber and the rubber reinforcing fiber are heated and pressurized, the rubber and the rubber reinforcing fiber are bonded.

  And, by adjusting the adhesive composition using the copolymer latex for adhesive of the present invention, the adhesive strength between the rubber and the rubber reinforcing fiber is improved while suppressing the strength reduction of the rubber reinforcing fiber due to heat treatment. Can be made.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to these Examples. In the examples, parts and% indicating the blending ratio are based on weight.
1. Synthesis of copolymer latex (A) for adhesive (1) Synthesis Examples 1 and 2
In an autoclave equipped with a stirrer, 135 parts of water, 1 part of a sodium naphthalenesulfonate / formalin condensate, 0.5 part of sodium hydroxide and 5.0 parts of potassium rosinate were added and dissolved.

  Next, the first-stage monomer composition (a-1) shown in Table 1 and 0.3 part of t-dodecyl mercaptan were added and emulsified.

  Subsequently, 0.5 part of potassium persulfate was added, the internal temperature was kept at 55 ° C., and the first stage monomer composition (a-1) was polymerized.

  When the polymerization conversion of the first-stage monomer composition (a-1) reached 82%, the second-stage monomer composition (a-2) and t-dodecyl mercaptan 0 shown in Table 1 were used. .25 parts was added continuously and polymerized subsequently.

When the polymerization conversion rate reached 93%, 0.1 part of hydroquinone was added to stop the polymerization, and then the unreacted monomer was removed by distillation under reduced pressure to obtain a copolymer latex (A). .
(2) Synthesis Example 3 and Comparative Synthesis Examples 1 and 2
In an autoclave equipped with a stirrer, 130 parts of water, 1 part of a sodium naphthalenesulfonate / formalin condensate, 0.5 part of sodium hydroxide and 4 parts of potassium rosinate were added and dissolved.

  Subsequently, the monomer composition (a) shown in Table 1 and 0.55 part of t-dodecyl mercaptan were added and emulsified.

  Subsequently, 0.5 part of potassium persulfate was added, the internal temperature was kept at 50 ° C., and the monomer composition was polymerized.

When the polymerization conversion rate reached 93%, 0.1 part of hydroquinone was added to stop the polymerization, and then the unreacted monomer was removed by distillation under reduced pressure to obtain a copolymer latex (A). .
2. Synthesis of copolymer latex (B) for adhesive (1) Synthesis Examples 4 to 6, Reference Synthesis Example 7 and Comparative Synthesis Examples 3 to 5
In an autoclave equipped with a stirrer, 125 parts of water, 0.8 part of sodium dodecylbenzenesulfonate, 0.2 part of sodium carbonate and 0.7 part of potassium persulfate were charged and sufficiently stirred.

  Next, 0.1 part of t-dodecyl mercaptan, each monomer composition (b) shown in Table 2 and cyclohexene were added, and the polymerization was carried out while maintaining the internal temperature at 65 ° C., so that the polymerization conversion rate was 98%. The polymerization was terminated when reached.

Next, an aqueous sodium hydroxide solution was added to adjust the pH to 8, and then unreacted monomers and the like were removed by steam distillation to obtain a copolymer latex (B).
(2) Measurement of glass transition temperature of copolymer latex (B) About 0.5 g of each obtained copolymer latex (B) was applied to a glass plate and dried at 70 ° C. for 4 hours to form a film. . The dried film is set in an aluminum pan for DSC test, the sample is homogenized again by heating, and then the measurement temperature is raised from -100 to 150 ° C at a rate of 10 ° C / min. The starting point was read and used as the glass transition temperature (° C.) of each copolymer latex (B).
3. A preparation copolymer latex adhesives copolymer latex (A) and the copolymer latex (B) were mixed and blended in proportions shown in Table 3 (solid), each of the embodiments, the reference Copolymer latexes for adhesives of Examples and Comparative Examples were obtained.
4). Preparation of Adhesive Composition After adding 4 parts of 10% sodium hydroxide to 260 parts of water and stirring, add 7.9 parts of resorcin and 8.6 parts of 37% formalin and stir and mix to 30 ° C. For 6 hours to synthesize resorcin-formalin resin.

Next, after adding water and stirring to 100 parts of the copolymer latex for adhesives of each example , each reference example and each comparative example so that the solid content concentration of the adhesive composition becomes 16.5% The total amount of resorcin-formalin resin and 11.4 parts of 28% aqueous ammonia were added and mixed with stirring.

Then, 46.3 parts of 27% blocked isocyanate dispersion (Meisei Chemical Industry Co., Ltd., SU-125F) was added and aged at 30 ° C. for 48 hours to obtain an adhesive composition.
4). Evaluation (1) Tire cord dipping treatment Using a test single cord dipping machine, the pretreated polyester tire cord (1500D / 2) was dipped in the obtained adhesive composition and dried at 120 ° C for 120 seconds. And then baked at 240 ° C. for 60 seconds.
(2) Rubber A rubber was prepared according to the following formulation.
<Rubber prescription>
Natural rubber 70 parts SBR rubber 30 parts FEF carbon 40 parts Process oil 4 parts Antigen RD (* 1) 2 parts Stearic acid 1.5 parts Zinc white 5 parts Vulcanization accelerator DM (* 2) 0.9 parts Sulfur 7 parts * 1: 2,2,4-trimethyl-1,2-dihydroquinoline polymer (manufactured by Sumitomo Chemical Co., Ltd.)
* 2: Dibenzothiazyl disulfide (3) Measurement of fiber strength The fiber strength of polyester tire cords treated with the adhesive compositions of each Example , each Reference Example and each Comparative Example was measured according to JIS-L1017. did. The results are shown in Table 3.
(4) Measurement of adhesive strength A polyester tire cord treated with the adhesive composition of each example , each reference example and each comparative example was sandwiched with rubber and 20 minutes at 160 ° C. (initial adhesive strength evaluation condition), or Then, vulcanization press was performed at 170 ° C. for 50 minutes (conditions for evaluating heat-resistant adhesion).

  The initial adhesive strength and heat-resistant adhesive strength between rubber and rubber reinforcing fiber were measured according to ASTM D2138-67 (H Pull Test). The results are shown in Table 3.

Claims (1)

Obtained by emulsion polymerization of a monomer composition (a) containing 35 to 75% by weight of a butadiene monomer, 10 to 30% by weight of a vinylpyridine monomer and 10 to 55% by weight of a styrene monomer. Copolymer latex (A) 50 to 90% by weight (in terms of solid content),
Butadiene monomer 3-25% by weight, vinylpyridine monomer 0-3 by weight%, styrene monomer 55-97 wt%, and, other copolymerizable monomers 0-20 % And a copolymer latex (B) obtained by emulsion polymerization of a monomer composition (b) that does not contain an ethylenically unsaturated carboxylic acid monomer. A copolymer latex for an adhesive, comprising: