JP2020105478A - Latex adhesive composition - Google Patents

Abstract

To provide a polychloroprene rubber latex having excellent adhesiveness and flexibility.SOLUTION: A latex adhesive composition is used which contains 2.0 to 8.0 pts.wt. of a nonaqueous dispersion type isocyanate compound and 7.0 pts.wt. or smaller of aqueous carbodiimide compound relative to 100 pts.wt. of a polychloroprene rubber latex is used.SELECTED DRAWING: None

Description

The present invention relates to a latex adhesive composition containing a polychloroprene rubber latex, and more specifically, a latex adhesive capable of achieving both excellent adhesive strength and flexibility in adhesion between foams or between foam and textiles. It relates to a composition.

BACKGROUND ART In the production of wet suits, supporters, insoles for sports shoes, shock absorbers, and the like, various foams are used as adherends. Conventionally, solvent-based adhesives based on polychloroprene rubber or the like have been used in these adhesions. However, volatilization of the organic solvent used for these adhesives causes health hazards for workers, fires in the workplace, and the like, and a latex-based adhesive composition free from such concerns is earnestly desired. Came.

Further, the conventional polychloroprene rubber latex has a problem that the adhesive strength is insufficient. As a method for solving this problem, in adhesion to a foam, an adhesive composition containing polychloroprene latex as a main component and a water-dispersible polyisocyanate as a cross-linking agent and an adhesion method thereof are known (for example, See Patent Documents 1 and 2.). However, when the adhesive composition coating is cured by isocyanate, the adhesive strength is improved, but there is a problem that the flexibility of the foamed product after adhesion is impaired. As a method for solving this problem, an adhesive composition containing polychloroprene latex as a main component and an aqueous dispersion type carbodiimide compound as a cross-linking agent in adhesion to a foam and an adhesion method thereof are known (for example, , Patent Document 3.). However, although the flexibility is good, there is a problem that the adhesive strength is insufficient, and particularly the toluene resistance required in the wetsuit manufacturing process is insufficient.

JP, 2000-104028, A JP, 2003-27024, A JP, 2008-168327, A

The present invention has been made in view of this problem, and an object thereof is a sport in which sufficient adhesive strength cannot be obtained with a conventional polychloroprene rubber latex-based adhesive composition, or flexibility decreases. It is intended to provide a latex adhesive composition having good adhesive strength and flexibility in adhering foams, which are materials for goods and wet suits, or in adhering foams and textiles.

The present inventor, under such a background, as a result of intensive studies to solve the above-mentioned problems, by mixing a non-aqueous dispersion type isocyanate with polychloroprene rubber latex, an adhesive composed mainly of polychloroprene rubber latex The inventors have found that it is possible to improve the adhesive strength between the agent composition and the foam, and have completed the present invention.

That is, the present invention is a latex adhesive composition containing 2.0 to 8.0 parts by weight of a non-aqueous dispersion type isocyanate compound and 7.0 parts by weight or less of a water-soluble carbodiimide compound with respect to 100 parts by weight of polychloroprene rubber latex. It is a thing.

Hereinafter, the present invention will be described in detail.

The latex adhesive composition in the present invention contains 2.0 to 8.0 parts by weight of a non-aqueous dispersion type isocyanate compound with respect to 100 parts by weight of polychloroprene rubber latex.

Various products of polychloroprene rubber latex are commercially available. Latex containing homopolymer of chloroprene monomer, chloroprene monomer, and one or more selected from carboxyl group-containing monomer and hydroxyl group-containing monomer. There are latexes of copolymers with monomers. Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, fumaric acid and maleic acid, and examples of the hydroxyl group-containing monomer include hydroxyethyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.

The polychloroprene latex is not particularly limited, but since the polychloroprene rubber becomes hard due to crystallization at a low temperature, a polychloroprene rubber latex containing a copolymer with one or more kinds of monomers is preferable.

The latex adhesive composition of the present invention needs to contain a non-aqueous dispersion type isocyanate compound in order to achieve both sufficient adhesive strength and flexibility.

The isocyanate compound is a compound having a functional group represented by -N=C=O, and in part, there is a water dispersion type (dispersion type) in which water dispersion is possible by modification treatment or the like, but such is the case in the present invention. A non-aqueous dispersion type that has not been treated is used. The content of the isocyanate group (NCO) is not particularly limited, but is generally 12 to 23%, and 15 to 21% is preferable in terms of cost and pot life balance. Further, as the skeleton of the isocyanate compound, one having a skeleton such as a trimer type or an allophanate type is known, and either type can be used in the present invention, but the trimer type is generally more adhesive strength. And the allophanate type is superior in terms of flexibility.

The adhesive composition of the present invention can increase the adhesive strength by containing a carbodiimide compound. The carbodiimide compound is a compound having a functional group represented by -N=C=N-, and is generally synthesized by decarboxylation condensation reaction of diisocyanate in the presence of a carbodiimidization catalyst. The NCN content is generally about 5 to 15%, but 10% or more with high reactivity is preferable. The carbodiimide compound has various forms such as a water-soluble type, an emulsifying type, and a water-dispersing type by hydrophilizing a part thereof or emulsifying it with an emulsifier or the like, and there are various commercially available products. Of these, water-soluble ones that are soluble in water are preferable from the viewpoint of toluene resistance and flexibility, and it is preferable not to use the emulsifying type and water-dispersing type because they impair the flexibility.

The non-aqueous dispersion type isocyanate compound used in the present invention is 2.0 to 8.0 parts by weight, preferably 3.0 to 7.0 parts by weight, and more preferably 4.0, based on 100 parts by weight of the polychloroprene rubber. ~ 5.0 parts by weight. If the amount of the non-aqueous dispersion type isocyanate compound is less than 2 parts by weight, the adhesive physical properties are deteriorated, and if it exceeds 8.0 parts by weight, the flexibility of the adherend is deteriorated. The amount of the water-soluble carbodiimide compound is 7.0 parts by weight or less based on 100 parts by weight of the polychloroprene rubber, more preferably 2.0 to 6.0 parts by weight, and further preferably 3.0 parts by weight based on 100 parts by weight of the polychloroprene rubber. ~ 5.0 parts by weight. When the amount of the water-dispersible carbodiimide compound is 7.0 parts by weight or less, the adhesive property and the coatability of the adhesive composition will be good.

The viscosity of the latex adhesive composition can be adjusted by various thickeners such as polyalkylene oxide, polyvinyl alcohol, hydrophobized cellulose, water-soluble polymers such as associative nonionic surfactants, and alkali-containing polymers composed of carboxyl group-containing polymers. The viscosity can be adjusted to a desired value by blending a solution type thickener, a silicate compound such as hectorite, and the like. At this time, it is preferable to use polyethylene oxide because the coatability at the time of coating by roll coating is good. Polyethylene oxide is preferably contained in an amount of 0.05 to 1.0 part by weight based on 100 parts by weight of the polychloroprene rubber latex. If necessary, a tackifying resin such as rosin ester, terpene phenol, petroleum resin, and coumarone resin, an antiaging agent, an antiseptic agent, an antifreezing agent, a film-forming aid, a plasticizer, a pH adjusting agent, etc. may be appropriately mixed. May be.

The adhesive composition of the present invention is used for adhering foams, which are materials for sports goods, wet suits, etc., or between foams and textiles.

Examples of sports goods and other foams include foams molded from polychloroprene rubber, ethylene-vinyl acetate copolymer, chlorosulfonated polyethylene, styrene butadiene rubber and the like. On the other hand, polychloroprene rubber or the like is used as the foam for the wet suit.

Textiles include synthetic fibers such as nylon and polyester, and non-woven fabrics of natural fibers such as cotton and silk. For wet suits, a water-repellent jersey is used.

The adhesive composition of the present invention has excellent adhesive strength between foams or between a foam and a textile, and the adhesive maintains excellent flexibility and toluene resistance.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

The room temperature peel strength and flexibility in the examples were measured and evaluated by the following methods.
<Measurement of normal temperature peel strength>
The bonded sample was cured in a thermostatic chamber at 23° C. for 1 day and then punched with a 25 mm×150 mm cutting machine to prepare a test piece. The end of each adherend was attached to a Tensilon tensile tester, and a 180° peel test at 23° C. was carried out at a pulling speed of 20 mm/min to observe the peeled state.

The peeled state was judged as follows.

(Good) Material failure (material failure)> Cohesive failure (cohesion)> Interface failure (interface) (Inferior)
<Measurement of toluene resistance>
After curing the adhered sample in a thermostatic chamber at 23° C. for 7 days, a room temperature peel test was performed by a Tensilon type tensile tester while dropping toluene into the sample, and the peeled state was observed. The peel strength was measured when the material was not destroyed.

The peeled state was judged as follows.

(Good) Material failure (material failure)> Cohesive failure (cohesion)> Interface failure (interface) (Inferior)
<Measurement of flexibility>
The adhered sample was cured in a thermostatic chamber at 23° C. for 7 days, and then punched with a 25 mm×150 mm cutting machine to prepare a test piece. Both ends of the test piece were attached to a Tensilon type tensile tester, and the tensile stress at 60% elongation at 23°C was measured under the condition of a tensile speed of 100 mm/min.

Example 1
100 parts by weight of polychloroprene rubber latex (chloroprene/methacrylic acid copolymer manufactured by Tosoh Corporation, trade name: SKYPREN GFL-890), non-aqueous dispersion type isocyanate compound A (manufactured by Tosoh Corporation, trade name: Coronate C) -2793, NCO 16.4%) 4 parts by weight, water-soluble carbodiimide compound (manufactured by Nisshinbo Chemical Co., Ltd., trade name: Carbodilite V-04, active ingredient 40%) 10 parts by weight (pure content 4 parts by weight), association type 2.5% by weight of a viscosity modifier (manufactured by ADEKA CORPORATION, trade name: ADECANOL UH-438) and a 10% aqueous solution of a polyethylene oxide compound (manufactured by Sumitomo Seika Chemical Co., Ltd., trade name: PEO-1, white powder) An adhesive composition was prepared by uniformly mixing 1 part by weight with a homomixer. Approximately 80 g/m ² (wet) of the adhesive composition was applied to a chloroprene rubber sponge piece, a water-repellent nylon jersey was layered over it without wrinkling, and an iron plate of about 10 kg was placed on it in an oven at 100°C for 90 seconds. Dried under pressure.

In the peeling test, the sponge material was mainly broken, the room temperature peel strength in the toluene resistance test was high, the tensile stress of the test piece was low, and the flexibility was good.

Example 2
An adhesive composition was prepared and evaluated according to Example 1 except that the weight of the non-aqueous dispersion type isocyanate compound to be mixed was changed to the amount shown in Table 1. In the peeling test, the sponge material was mainly broken, the room temperature peel strength in the toluene resistance test was high, the tensile stress of the test piece was low, and the flexibility was good.

Example 3
An adhesive composition was prepared and evaluated according to Example 1 except that the non-aqueous dispersion type isocyanate compound to be mixed was changed to isocyanate compound B (manufactured by Tosoh Corporation, trade name: Coronate C-2785, NCO 19.2%). I went. In the peel test, the sponge material was mainly broken, and the room temperature peel strength and flexibility were good.

Examples 4, 5
An adhesive composition was prepared and evaluated according to Example 1 except that the weight of the water-soluble carbodiimide compound to be mixed was changed to the amount shown in Table 1. In the peel test, the sponge material was mainly broken, and the room temperature peel strength and flexibility were good.

Example 6
An adhesive composition was prepared and evaluated according to Example 1 except that the weight of the water-soluble carbodiimide compound to be mixed was changed to the amount shown in Table 1. The flexibility was good, and the adhesive peel strength was high and good.

Example 7
An adhesive composition was prepared and evaluated according to Example 1 except that the water-soluble carbodiimide was not mixed. In the peel test, the sponge material was mainly broken, and the room temperature peel strength and flexibility were good.

Example 8
An adhesive composition was prepared and evaluated according to Example 1 except that the weight of the non-aqueous dispersion type isocyanate compound to be mixed was changed to the amount shown in Table 1 and the water-soluble carbodiimide was not mixed. In the peel test, the sponge material was mainly broken, and the room temperature peel strength and flexibility were good.

Table 1 shows the composition and evaluation results of the samples prepared in Examples 1 to 8.

Comparative Example 1
An adhesive composition was prepared and evaluated according to Example 1 except that the isocyanate compound to be mixed was changed to a water-dispersed isocyanate compound (Tosoh Corp., trade name: Coronate AQ-140, NCO 18.0%). It was The adhesive properties at room temperature were good, but the flexibility and toluene resistance were poor.

Comparative example 2
An adhesive composition was prepared and evaluated according to Example 1 except that the weight of the non-aqueous dispersion type isocyanate to be mixed was changed to the amount shown in Table 2. The flexibility was good, but the adhesive properties were poor.

Comparative Example 3
An adhesive composition was prepared and evaluated according to Example 1 except that the weight of the non-aqueous dispersion type isocyanate to be mixed was changed to the amount shown in Table 2. Application of the adhesive composition was difficult, resulting in poor adhesion.

Comparative Example 4
An adhesive composition was prepared and evaluated according to Example 1 except that the weight of the water-soluble carbodiimide compound to be mixed was changed to the amount shown in Table 2. Application of the adhesive composition was difficult, resulting in poor adhesion.

Reference example 100 parts by weight of polychloroprene rubber latex (chloroprene/methacrylic acid copolymer manufactured by Tosoh Corp., trade name: SKYPREN GFL-890), water-dispersible carbodiimide compound (produced by Nisshinbo Chemical Co., Ltd., trade name: carbodilite) 4.0 parts by weight of E-05, active ingredient 40%) and 2.5 parts by weight of an associative viscosity modifier (manufactured by ADEKA CORPORATION, trade name: ADECANOL UH-438) are uniformly mixed and bonded by a homomixer. An agent composition was prepared and tested under the conditions of Example 1. The adhesive properties and flexibility at room temperature were good, but the toluene resistance was poor.

Table 2 shows the compositions and evaluation results of the samples prepared in Comparative Examples 1 to 4 and Reference Example.

Claims (9)

Latex adhesive composition containing 2.0 to 8.0 parts by weight of a non-aqueous dispersion type isocyanate compound and 7.0 parts by weight or less of a water-soluble carbodiimide compound with respect to 100 parts by weight of polychloroprene rubber latex. .. The polychloroprene rubber in the polychloroprene rubber latex is a copolymer of a chloroprene monomer and one or more monomers selected from a carboxyl group-containing monomer and a hydroxyl group-containing monomer. The latex adhesive composition according to claim 1. The latex adhesive composition according to claim 1 or 2, wherein the content of the non-aqueous dispersion type isocyanate compound is 3.0 to 7.0 parts by weight. Content of a water-soluble carbodiimide compound is 2.0-6.0 weight part, The latex adhesive composition in any one of Claims 1-3 characterized by the above-mentioned. The latex adhesive composition according to any one of claims 1 to 4, which does not contain an emulsion-dispersion type carbodiimide compound. The latex adhesive composition according to any one of claims 1 to 5, comprising 0.05 to 1.0 part by weight of polyethylene oxide based on 100 parts by weight of the polychloroprene rubber latex. An adhesive in which the foams or the foam and the textile are bonded with the latex adhesive composition according to any one of claims 1 to 6. The adhesive body according to claim 7, wherein the material of the foam is polychloroprene rubber. A wetsuit made of the adhesive body according to claim 7.