KR102166231B1 - Copolymer latex for adhesive, and adhesive composition - Google Patents

Abstract

The adhesive copolymer latex is an adhesive obtained by emulsion polymerization of a monomer composition containing 30 to 80 mass% of an aliphatic conjugated diene monomer, 5 to 25 mass% of a vinylpyridine monomer, and 15 to 65 mass% of other monomers copolymerizable therewith. As a copolymer latex for use, 0.5 to 4.0 parts by mass of fatty acid soap is contained with respect to 100 parts by mass of the monomer composition, and the angle of the swash plate is set to 20° in the inclined vortex test specified in JIS Z 0237:2009 with respect to the dry film. When set and implemented, the ball number is 3 or less.

Description

Copolymer latex for adhesive and adhesive composition {COPOLYMER LATEX FOR ADHESIVE, AND ADHESIVE COMPOSITION}

The present invention relates to an adhesive copolymer latex and an adhesive composition, in particular, to an adhesive copolymer latex and adhesive composition for bonding rubber and fibers.

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

These rubber reinforcing fibers are different from copolymer latex for adhesives (generally, butadiene-vinylpyridine copolymer latex, or butadiene-vinylpyridine copolymer latex, so as to ensure adhesion to rubber products. It is treated using an adhesive composition containing a mixture of rubber latex) and a resorcin-formalin resin.

In the treatment with the adhesive composition, rubber reinforcing fibers are immersed in the adhesive composition. At this time, if the mechanical stability of the adhesive composition is inferior, the treatment operability of the fibers is lowered.

Therefore, as a method for producing a copolymer latex capable of improving the mechanical stability of the adhesive composition, for example, it has been proposed to emulsion-polymerize a vinylpyridine-based monomer and a copolymerizable monomer using a sulfonate of an aromatic vinyl compound as a reactive surfactant. (See, for example, Patent Document 1).

In the copolymer latex obtained by this production method, generation of aggregates in the adhesive composition can be suppressed when the rubber reinforcing fiber is immersed in the adhesive composition.

Japanese Patent Laid-Open No. Hei 8-134273

By the way, in the copolymer latex obtained by the method described in patent document 1, the effect of improving the mechanical stability of an adhesive composition may be insufficient.

In addition, when the dried product of the adhesive composition is sticky, the adhesive composition may easily adhere to the processing machine. When the adhesion amount of the adhesive composition to the treatment machine increases, an operation of removing the adhesion matter is required, and the treatment operability of the fiber is deteriorated.

Accordingly, an object of the present invention is to provide an adhesive copolymer latex capable of improving the treatment operability for fibers of the adhesive composition, and an adhesive composition containing the adhesive copolymer latex.

The copolymer latex for adhesive of the present invention is emulsion polymerization of a monomer composition containing 30 to 80% by mass of an aliphatic conjugated diene monomer, 5 to 25% by mass of a vinylpyridine monomer, and 15 to 65% by mass of other monomers copolymerizable therewith. As a copolymer latex for adhesives obtained by this method, it contains 0.5 to 4.0 parts by mass of fatty acid soap based on 100 parts by mass of the monomer composition, and the dry coating thereof was subjected to an oblique ball tack test specified in JIS Z 0237:2009. When the angle of the swash plate is set to 20°, the ball number is 3 or less.

In addition, it is preferable that the copolymer latex for adhesives of the present invention further contains 0.1 to 3 parts by mass of a nonionic surfactant per 100 parts by mass of the monomer composition.

In addition, the copolymer latex for adhesives of the present invention is a Mooney viscosity specified in JIS K 6300-1:2001 measured under conditions of a measurement temperature of 100°C, a preheat time of 1 minute, and a rotor rotation time of 4 minutes using an L-type rotor. It is suitable that the (Mooney viscosity) is 20-100M.

Moreover, the adhesive composition of this invention is characterized by containing the said copolymer latex for adhesives.

The copolymer latex for adhesives of the present invention has a ball number of 3 or less when the inclined voltack test specified in JIS Z 0237:2009 is carried out with the angle of the inclined plate set to 20° with respect to the dry film thereof.

Therefore, when the adhesive composition containing the copolymer latex for adhesives of the present invention is treated to fibers, adhesion of the adhesive composition to the processing machine can be reduced.

As a result, it is possible to improve the treatment operability for fibers of the adhesive composition.

The copolymer latex for adhesives of the present invention is obtained by emulsion polymerization of a monomer composition containing an aliphatic conjugated diene monomer, a vinylpyridine monomer, and other monomers copolymerizable therewith.

Examples of aliphatic conjugated diene-based monomers include butadiene-based monomers such as 1,3-butadiene, 2-methyl-1,3-butadiene, and 2,3-dimethyl-1,3-butadiene. And the like.

These aliphatic conjugated diene-based monomers may be used alone (only one type), or two or more types may be used in combination.

Among these aliphatic conjugated diene-based monomers, preferably a butadiene-based monomer is mentioned, and more preferably 1,3-butadiene is used.

The aliphatic conjugated diene-based monomer is blended in the monomer composition in a ratio of, for example, 30% by mass or more, preferably 40% by mass or more, and, for example, 80% by mass or less, preferably 75% by mass or less.

If the blending ratio of the aliphatic conjugated diene-based monomer is less than the above lower limit, the initial adhesive strength may decrease. In addition, when the blending ratio of the aliphatic conjugated diene-based monomer exceeds the above upper limit, the heat-resistant adhesive strength may decrease.

Examples of vinylpyridine-based monomers include 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, and 2-methyl-5-vinylpyridine.

These vinylpyridine-based monomers may be used alone (only one type) or two or more types may be used in combination.

Among these vinylpyridine-based monomers, 2-vinylpyridine is preferably used.

The vinylpyridine monomer is blended in the monomer composition in a ratio of, for example, 5% by mass or more, preferably 7% by mass or more, and, for example, 25% by mass or less.

If the blending ratio of the vinylpyridine-based monomer is less than the above lower limit, the initial adhesive strength and heat-resistant adhesive strength may decrease. In addition, when the blending ratio of the vinylpyridine-based monomer exceeds the above upper limit, the initial adhesive strength may decrease.

Other monomers copolymerizable with the above-described aliphatic conjugated diene monomer and vinylpyridine monomer include, for example, an aromatic vinyl monomer, a vinyl cyanide monomer, an ethylenically unsaturated carboxylic acid monomer, an ethylenically unsaturated carboxylic acid alkyl ester monomer, and a hydroxyalkyl group. An unsaturated monomer and an ethylenically unsaturated carboxylic acid amide monomer.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, and monochlorostyrene.

As a vinyl cyanide monomer, acrylonitrile, methacrylonitrile, etc. are mentioned, for example.

Examples of the ethylenically unsaturated carboxylic acid monomer include ethylenically unsaturated monocarboxylic acid monomers such as acrylic acid and methacrylic acid, such as ethylenically unsaturated dicarboxylic acid monomers (or anhydrides thereof) such as fumaric acid and itaconic acid.

Examples of ethylenically unsaturated carboxylic acid alkyl ester monomers include acrylic acid alkyl ester monomers such as methyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate, such as methyl methacrylate, ethyl methacrylate, and 2-ethylhexyl methacrylate. The methacrylic acid alkyl ester monomer is mentioned.

Examples of the unsaturated monomer containing a hydroxyalkyl group include β-hydroxyethyl acrylate and β-hydroxyethyl methacrylate.

As an ethylenically unsaturated carboxylic acid amide monomer, acrylamide, methacrylamide, etc. are mentioned, for example.

These other monomers may be used alone (only one type), or may be used in combination of two or more.

Among these other monomers, preferably an aromatic vinyl-based monomer alone or a combination of an aromatic vinyl-based monomer and a cyanide vinyl monomer, an ethylenically unsaturated carboxylic acid monomer, and an ethylenically unsaturated carboxylic acid alkyl ester monomer, More preferably, a combination of styrene and any one of α-methylstyrene, acrylonitrile, acrylic acid, itaconic acid and methyl methacrylate may be mentioned.

Other monomers are blended in the monomer composition in a ratio of, for example, 15% by mass or more, for example, 65% by mass or less, and preferably 60% by mass or less.

When the blending ratio of other monomers exceeds the above upper limit, the initial adhesive strength and heat-resistant adhesive strength may decrease.

And, in order to emulsion-polymerize the monomer composition, an emulsifier and a polymerization initiator are added to the monomer composition.

Fatty acid soap is mentioned as an emulsifier.

As fatty acid soap, for example, lithium laurate, sodium laurate, potassium laurate, ammonium laurate, lithium myristic acid, sodium myristic acid, potassium myristic acid, ammonium myristic acid, lithium stearate, stearic acid Saturated fatty acid soap having an alkyl group having 12 to 18 carbon atoms, such as sodium acid, potassium stearate, ammonium stearate, lithium palmitate, sodium palmitate, potassium palmitate, and ammonium palmitate, such as lithium hexadecenoate, Unsaturated fatty acids having 12 to 18 carbon atoms, such as sodium hexadecenoate, potassium hexadecenoate, ammonium hexadecenoate, lithium oleate, sodium oleate, potassium oleate, ammonium oleate, lithium linoleate, sodium linoleate, potassium linoleate, and ammonium linoleate Soaps, such as fatty acid soaps obtained from tallow (mixture of myristic acid, stearic acid, palmitic acid, oleic acid and linoleic acid), i.e. lithium myristic acid, lithium stearate, lithium palmitate, lithium oleate and lithium linoleate Mixture of sodium myristic acid, sodium stearate, sodium palmitate, sodium oleate and sodium linoleate mixture, potassium myristic acid, potassium stearate, potassium palmitate, potassium oleate and potassium linoleate mixture, myristic acid And mixtures of ammonium, ammonium stearate, ammonium palmitate, ammonium oleate and ammonium linoleate, and the like.

These fatty acid soaps may be used alone (only one type) or two or more types may be used in combination.

Among these fatty acid soaps, preferably an unsaturated fatty acid soap is used, and more preferably, an oleic acid soap (oleic acid salt) is used.

Fatty acid soap is added in a ratio of, for example, 0.5 parts by mass or more, preferably 1.0 parts by mass or more, and, for example, 4.0 parts by mass or less, preferably 3.0 parts by mass or less, based on 100 parts by mass of the monomer composition.

If the blending ratio of the fatty acid soap is less than the above lower limit, the dried product of the adhesive composition described later may be sticky. When the blending ratio of the fatty acid soap exceeds the above upper limit, bubbles tend to occur when preparing the adhesive composition described later, and the work efficiency of preparing the adhesive composition may be inferior.

Further, examples of the emulsifier include anionic surfactants other than the above-described fatty acid soaps, nonionic surfactants, and the like.

Examples of anionic surfactants other than fatty acid soaps include rosin acid soaps such as sodium rosinate and potassium rosinate, such as sulfuric ester salts of higher alcohols, such as alkylbenzene sulfonates, such as alkyldiphenylether sulfonates, such as aliphatic sulfones. Acid salts, such as sulfuric ester salts of nonionic surfactants, such as formalin condensates of naphthalene sulfonates.

Anionic surfactants other than these fatty acid soaps may be used alone (only one type) or two or more types may be used in combination.

Among these anionic surfactants other than fatty acid soaps, rosin acid soaps are preferably used.

Anionic surfactants other than fatty acid soap are added in a ratio of, for example, 1.0 parts by mass or more, preferably 1.5 parts by mass or more, and, for example, 5.0 parts by mass or less, preferably 4.0 parts by mass or less, based on 100 parts by mass of the monomer composition. do.

If the blending ratio of anionic surfactants other than fatty acid soap is less than the above lower limit, the stability of the copolymer latex tends to be inferior, and if the blending ratio of anionic surfactants other than fatty acid soap exceeds the above upper limit, the adhesive composition It becomes easy to generate bubbles.

Examples of the nonionic surfactant include polyoxyethylene alkylphenyl ether types such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether, such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, and polyoxyethylene. And polyoxyethylene alkyl ether types such as ethylene stearyl ether, polyoxyethylene myristyl ether, and polyoxyethylene oleyl ether.

These nonionic surfactants may be used alone (only one type), or two or more types may be used in combination.

Among these nonionic surfactants, preferably polyoxyethylene alkyl ether type, more preferably polyoxyethylene lauryl ether is used.

The nonionic surfactant is added in a ratio of, for example, 0.1 parts by mass or more, preferably 0.3 parts by mass or more, and, for example, 3 parts by mass or less, preferably 2.0 parts by mass or less, based on 100 parts by mass of the monomer composition.

When the blending ratio of the nonionic surfactant is less than the lower limit, the dried product of the adhesive composition described later may be sticky. When the blending ratio of the nonionic surfactant exceeds the above upper limit, bubbles tend to occur when preparing the adhesive composition described later, and the working efficiency of the preparation operation of the adhesive composition may be inferior.

On the other hand, when rosin acid soap, fatty acid soap, and nonionic surfactant are used as emulsifiers for polymerization of the copolymer latex, rosin acid soap, fatty acid soap and nonionic surfactant may not be blended in the obtained copolymer latex. In addition, when rosin acid soap, fatty acid soap, and nonionic surfactant are used as emulsifiers for polymerization of the copolymer latex, rosin acid soap, fatty acid soap, and nonionic surfactant may be further added to the obtained copolymer latex. Specifically, the copolymer latex can be polymerized using rosin acid soap as an emulsifier, and a fatty acid soap and a nonionic surfactant can be blended into the obtained copolymer latex.

The polymerization initiator is a radical polymerization initiator, and a water-soluble polymerization initiator such as potassium persulfate, sodium persulfate, and ammonium persulfate, such as cumene hydroperoxide, benzoyl peroxide, t-butyl hydroperoxide, acetyl peroxide, diisopropylbenzene hydrogen Oil-soluble polymerization initiators, such as loperoxide and 1,1,3,3-tetramethylbutyl hydroperoxide, are mentioned.

Among these polymerization initiators, potassium persulfate, sodium persulfate, and ammonium persulfate are preferably mentioned as a water-soluble polymerization initiator, and cumene hydroperoxide is mentioned as an oil-soluble polymerization initiator.

The polymerization initiator is added in a ratio of, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more, and, for example, 3.0 parts by mass or less, preferably 2.0 parts by mass or less, based on 100 parts by mass of the monomer composition.

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

Examples of the reducing agent include sulfite, hydrogen sulfite, pyrosulfite, adithionate, dithionate, thiosulfate, formaldehyde sulfonate, benzaldehyde sulfonate, ferrous sulfate, such as L-ascorbic acid, erythorbic acid. , Carboxylic acids such as tartaric acid and citric acid, and salts thereof, such as reducing sugars such as dextrose and saccharose, such as amines such as dimethylaniline and triethanolamine.

Among these reducing agents, preferably, carboxylic acids and salts thereof are mentioned, and more preferably, L-ascorbic acid and erythorbic acid are used.

The reducing agent is added in a ratio of, for example, 0 parts by mass or more, and, for example, 1.0 parts by mass or less, and preferably 0.7 parts by mass or less, based on 100 parts by mass of the polymerization initiator.

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 dimethyl Xantogen compounds such as xanthogen disulfide and diisopropyl xanthogen disulfide, such as tetramethyl thiuram disulfide, tetraethyl thiuram disulfide, and thiuram compounds such as tetramethyl thiuram monosulfide, such as 2,6- Phenol compounds such as di-t-butyl-4-methylphenol and styrene phenol, such as allyl compounds such as allyl alcohol, such as halogenated hydrocarbon compounds such as dichloromethane, dibromomethane, and carbon tetrabromide, such as Vinyl ethers such as α-benzyloxystyrene, α-benzyloxyacrylonitrile, and α-benzyloxyacrylamide, such as triphenylethane, pentaphenylethane, acrolein, methacrolein, thioglycolic acid, thio Malic acid, 2-ethylhexylthioglycolate, α-methylstyrene dimer, and the like.

These chain transfer agents may be used alone (only one type), or two or more types may be used in combination.

Among these chain transfer agents, preferably, an alkyl mercaptan is mentioned, and more preferably, n-octyl mercaptan and t-dodecyl mercaptan are used.

The chain transfer agent is added in a ratio of, for example, 0 parts by mass or more, preferably 0.05 parts by mass or more, and, for example, 10 parts by mass or less, preferably 7 parts by mass or less, based on 100 parts by mass of the monomer composition.

Moreover, in emulsion polymerization, hydrocarbons can be added as needed (as an optional component).

Examples of hydrocarbons include saturated hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane, and cycloheptane, such as pentene, hexene, heptene, cyclopentene, cyclohexene, cycloheptene, 4-methylcyclohexene And unsaturated hydrocarbons such as 1-methylcyclohexene, and aromatic hydrocarbons such as benzene, toluene, and xylene.

As hydrocarbons, preferably, cyclohexene and toluene are mentioned. If the hydrocarbons are cyclohexene or toluene, they can be recovered and reused by steam distillation or the like after polymerization at a low boiling point, which is suitable from the viewpoint of reducing environmental load.

In addition, in order to emulsion-polymerize the monomer composition, if necessary (as an optional component), an electrolyte such as sodium hydroxide or sodium carbonate, a polymerization accelerator, a chelating agent, and the like can be added.

On the other hand, the method of emulsion polymerization is not particularly limited, for example, a known emulsion polymerization method such as a batch addition polymerization method, a divided addition polymerization method, a continuous addition polymerization method, a two-stage polymerization method, and a power feed polymerization method can be employed.

Then, the monomer composition is emulsion-polymerized so that its polymerization conversion ratio is, for example, 90% or more, and then, a polymerization inhibitor such as hydroquinone is added to stop the polymerization reaction, and unreacted by a method such as distillation under reduced pressure. Remove the monomer.

Thereby, the copolymer latex for adhesives is prepared.

The particle diameter of the copolymer of the obtained adhesive copolymer latex is, for example, 70 nm or more, preferably 90 nm or more, and for example 300 nm or less, preferably 250 nm or less.

The solid content concentration of the obtained adhesive copolymer latex is, for example, 35 mass% or more, preferably 40 mass% or more, and, for example, 55 mass% or less, preferably 50 mass% or less.

The Mooney viscosity of the solid content of the obtained adhesive copolymer latex (JIS K 6300-1:2001, L-type rotor, preheating time 1 minute, rotor rotation time 4 minutes, measurement temperature 100°C) is, for example, 20M or more, preferably 30M. It is more than, for example, 100M or less, preferably 80M or less. If the Mooney viscosity is less than 20M, the dried product of the adhesive composition described later may be sticky. In addition, when it exceeds 100M, initial adhesive strength may decrease.

The ball number (angle of the inclined plate: 20°) in the inclined bolt test (JIS Z 0237:2009) of the dried film of the obtained adhesive copolymer latex is, for example, 3 or less, preferably 2 or less.

The obtained copolymer latex for adhesive is blended into 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. In addition, a filler, a softener, a vulcanizing agent, a vulcanization accelerator, and the like can be blended into the rubber.

Examples of the rubber reinforcing fibers include nylon fibers, polyester fibers, aramid fibers, and glass fibers. In addition, the form of these fibers is not particularly limited, and examples thereof include cords, cables, woven fabrics, canvas, short fibers, and the like.

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

In order to prepare an adhesive composition, a resorcin-formalin resin, for example, 5 parts by mass or more, and, for example, 100 parts by mass or less, preferably 90 parts by mass or less, is blended with respect to 100 parts by mass (solid content) of the adhesive copolymer latex. do.

In addition, in the adhesive composition, if necessary (as an optional component), isocyanate, block isocyanate, ethylene urea, 2,6-bis(2,4-dihydroxyphenylmethyl)-4-chlorophenol, Modified resorcin-formalin resin, such as a condensate of sulfur monochloride and resorcin and a mixture of resorcin-formalin condensation, polyepoxide, modified polyvinyl chloride, adhesion aid for carbon black, pH adjuster such as ammonia water, filler , A crosslinking agent, a vulcanizing agent, a vulcanization accelerator, and the like can be blended.

The solid content concentration of the adhesive composition is, for example, 10 mass% or more, preferably 13 mass% or more, and, for example, 25 mass% or less, preferably 20 mass% or less.

Then, in order to bond the rubber and the rubber reinforcing fibers, the adhesive composition is first treated with the rubber reinforcing fibers.

In order to treat the adhesive composition with the rubber reinforcing fibers, for example, the rubber reinforcing fibers are immersed in the adhesive composition using a processing device such as a dipping machine.

At this time, if the aggregate or dry matter of the adhesive composition is sticky, the aggregate or dry matter of the adhesive composition may be liable to adhere to the processing device (specifically, the roller of the dipping machine). In addition, if the adherend attached to the processing device is left unattended, there is a fear that the adherend adheres to the rubber reinforcing fibers from the processing device, resulting in poor adhesion. Therefore, with an increase in the adhesion amount of the adhesive composition to the treatment machine, it is necessary to remove the deposit from the treatment device, and the treatment operability of the immersion treatment may decrease.

From this point of view, the ball number (angle of the inclined plate: 20°) in the inclined ball tack test (JIS Z 0237:2009) of the dry film of the copolymer latex for adhesive of the present invention is 3 or less. Therefore, the adhesive copolymer latex of the present invention has reduced stickiness of its dried film.

Thereby, the adhesive composition containing the copolymer latex for adhesives of the present invention also reduces the stickiness of the dry film thereof, and the stickiness of the treatment device is reduced.

As a result, it is possible to suppress a decrease in the treatment operability of the immersion treatment.

Thereafter, the rubber reinforcing fibers treated with the adhesive composition are, for example, 100°C or higher, preferably 110°C or higher, and also at 180°C or lower, preferably 160°C or lower, such as 80 seconds or longer, preferably 100 seconds or longer. , Further, for example, 200 seconds or less, preferably 150 seconds or less, and then, for example, 180° C. or more, preferably 200° C. or more, and, for example, 300° C. or less, preferably 260° C. or less, such as 30 seconds or more , Preferably it is heated for 50 seconds or more, and for example 100 seconds or less, preferably 80 seconds or less, and the adhesive composition is baked with respect to the rubber reinforcing fibers.

Then, after the treatment, when the rubber is brought into contact with the rubber reinforcing fibers treated with the adhesive composition, and the rubber and the rubber reinforcing fibers are heated and pressed, the rubber and the rubber reinforcing fibers are adhered.

Example

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. On the other hand, in the examples, parts and% indicating the blending ratio are based on mass. In addition, numerical values such as the blending ratio in the examples can be replaced with the upper limit value or the lower limit value of the corresponding portion described in the above embodiment.

1. Synthesis of adhesive copolymer latex

(1) Examples

(1-1) Example 1

To 130 parts by mass of water in an autoclave equipped with a stirrer, an emulsifier shown in the following table, 1 part by mass of a formalin condensate of sodium naphthalene sulfonate, and 0.3 parts by mass of sodium hydroxide were added and dissolved.

Subsequently, monomer composition A and t-dodecylmercaptan shown in the following table were added to an autoclave and emulsified.

Then, 0.5 parts by mass of potassium persulfate was added to the autoclave, and the internal temperature was maintained at 55°C to polymerize the monomer composition A (polymerization in the first stage).

Next, when the polymerization conversion ratio of the monomer composition A reached 85%, the monomer composition B and t-dodecylmercaptan shown in the following table were added to the autoclave, and polymerization was continued (polymerization in the second stage).

When the polymerization conversion ratio of the monomer composition A and the monomer composition B reached 94%, 0.1 parts by mass of hydroquinone was added to stop the polymerization.

Thereafter, the unreacted monomer was removed by distillation under reduced pressure to obtain a copolymer latex for an adhesive.

(1-2) Examples 2 and 4

In the same manner as in Example 1, the monomer composition shown in the following table was subjected to emulsion polymerization using an emulsifier shown in the following table to obtain a copolymer latex for an adhesive.

(1-3) Example 3

In the same manner as in Example 1, except that the monomer composition was not divided (that is, only monomer composition A) was polymerized at 55°C, the monomer composition shown in the following table was emulsion-polymerized using the emulsifier shown in the following table, The coalescence latex was obtained.

(1-4) Example 5

In the same manner as in Example 3, the monomer composition shown in the following table was subjected to emulsion polymerization using an emulsifier shown in the following table to obtain a copolymer latex for an adhesive.

(2) Comparative example

(2-1) Comparative Examples 1, 2, 4

In the same manner as in Example 3, the monomer composition shown in the following table was subjected to emulsion polymerization using an emulsifier shown in the following table to obtain a copolymer latex for an adhesive.

(2-2) Comparative Example 3

In the same manner as in Example 1, the monomer composition shown in the following table was subjected to emulsion polymerization using an emulsifier shown in the following table to obtain a copolymer latex for an adhesive.

2. Evaluation of adhesive copolymer latex

(1) Measurement of Mooney viscosity

Drying the copolymer latex for adhesives of each of the Examples and Comparative Examples, and the Mooney viscosity of the obtained solid (resin powder) according to JIS K 6300-1:2001, measured using an L-type rotor temperature 100 ℃, preheating time 1 It measured on the conditions of minutes and a rotor rotation time of 4 minutes. The results are shown in Table 1 below.

(2) Voltack test of dry film

Copolymer latex for adhesive was coated on a commercially available polyethylene terephthalate film so that the applied amount after drying was about 7 g/m ² , and dried with a dryer at 120° C. for 1 minute to prepare a dry film of the copolymer latex for adhesive.

Then, the obtained dry film was humidified overnight at a temperature of 23°C and a humidity of 50%.

Then, using a ball tack tester (manufactured by Tester Industries), in accordance with JIS Z 0237 (adhesive tape/adhesive sheet test method), in accordance with the tack test method (formal method), on a dry film under conditions of an inclination angle of 20°. Rolled the ball.

Among the balls stuck to the dry film and stopped, the largest ball was found.

The ball numbers of the found balls are shown in Table 1 below.

3. Preparation of adhesive composition

After adding and stirring 4 parts by mass of 10% sodium hydroxide to 239 parts by mass of water, 7.9 parts by mass of resorcin and 8.6 parts by mass of 37% formalin were added and mixed with stirring, and aged at 30° C. for 6 hours to synthesize a resorcin-formalin resin. did.

Separately, water was added to 100 parts by mass of the adhesive copolymer latex for each of the Examples and Comparative Examples so that the solid content concentration at the time of preparing the adhesive composition became 16.5% by mass and stirred to dilute the adhesive copolymer latex.

The total amount of the resorcin-formalin resin and 11.4 parts by mass of 28% aqueous ammonia were added and stirred to the diluted product of the adhesive copolymer latex.

To the obtained mixture, 46.3 parts by mass of a 27% block isocyanate dispersion (made by Meisei Chemical Industries, Ltd. SU-125F) was added, and it was aged at 30° C. for 48 hours to obtain an adhesive composition having a solid content concentration of 16.5% by mass.

4. Evaluation of adhesive composition

(1) Adhesion test

(1-1) Tire cord immersion treatment

Using a test single cord dipping machine, pretreated polyethylene terephthalate tire cord (1670dtex/2) was immersed in the adhesive composition obtained in each Example and each Comparative Example, dried at 120°C for 120 seconds, and then 60 at 240°C. Burned for a second.

(1-2) rubber

Rubber was prepared according to the following formulation.

(1-3) Measurement of initial adhesion

The polyethylene terephthalate tire cord treated with the adhesive composition was sandwiched with rubber, and vulcanization pressed at 160°C for 20 minutes.

The initial adhesive strength of rubber and rubber reinforcing fibers was measured according to ASTM D2138-67 (H Pull Test). The results are shown in Table 1 below.

(1-4) Measurement of heat-resistant adhesion

The polyethylene terephthalate tire cord treated with the adhesive composition was sandwiched with rubber, and vulcanization pressed at 170°C for 50 minutes.

Heat-resistant adhesion between rubber and rubber reinforcing fibers was measured according to ASTM D2138-67 (H Pull Test). The results are shown in Table 1 below.

(2) antifoaming test

200 g (200 ml) of the adhesive composition obtained using the copolymer latex for adhesives of each of the Examples and Comparative Examples was put into a scalpel cylinder (1000 ml), and 700 ml of air was blown into the adhesive composition to foam.

The upper end of the adhesive composition immediately after foaming was confirmed by the scale of the scalpel cylinder. Moreover, the time until the bubble disappears was measured, and it evaluated based on the following evaluation criteria. The results are shown in Table 1 below.

<Evaluation criteria for whipping property>

○: The upper end of the adhesive composition immediately after foaming is less than 700 ml

△: The upper end of the adhesive composition immediately after foaming is 700 ml or more and less than 900 ml

X: 900 ml or more of the upper end of the adhesive composition immediately after foaming

<Evaluation criteria for antifoam>

○: The time until the bubble disappears is less than 70 seconds

△: The time until the bubble disappears is 70 seconds or more and less than 90 seconds

X: The time until the bubble disappears is 90 seconds or more

On the other hand, the above invention was provided as an exemplary embodiment of the present invention, but this is only a mere illustration and should not be interpreted limitedly. Modification examples of the present invention that are apparent by those skilled in the art are included in the claims to be described later.

Claims (5)

An emulsion polymerization product of a monomer composition containing 30 to 80% by mass of an aliphatic conjugated diene monomer, 5 to 25% by mass of a vinylpyridine monomer, and 15 to 65% by mass of another monomer copolymerizable therewith, and an emulsifier for emulsifying the monomer composition. As a copolymer latex for an adhesive containing at least rosin acid soap,
Fatty soap,
Containing the aliphatic conjugated diene monomer, the vinylpyridine monomer, and a nonionic surfactant that does not copolymerize with the other monomers,
The fatty acid soap is contained 0.5 to 4.0 parts by mass per 100 parts by mass of the monomer composition,
The nonionic surfactant is contained in an amount of 0.1 to 3 parts by mass based on 100 parts by mass of the monomer composition,
For the dry film, when the inclined voltack test specified in JIS Z 0237:2009 was carried out by setting the angle of the inclined plate to 20°, the ball number became 2 or less
Copolymer latex for an adhesive, characterized in that. The method of claim 1,
Air for adhesives characterized in that the Mooney viscosity specified in JIS K 6300-1:2001 measured under conditions of 100°C measurement temperature, 1 minute preheating time, and 4 minutes rotor rotation time using an L-type rotor is 20-100M. Coalescence latex. An adhesive composition comprising the copolymer latex for an adhesive according to claim 1 or 2. delete delete