JP6848724B2 - Polychloroprene rubber latex adhesive - Google Patents

Description

The present invention relates to a polychloroprene rubber latex adhesive, more specifically, a polychloroprene rubber latex adhesive capable of achieving both excellent adhesive strength and flexibility in bonding foams to each other or between a foam and a textile. is there.

Various foams are used as adherends in the manufacture of wet suits, supporters, insoles for sports shoes, shock absorbers, and the like. Conventionally, a solvent-based adhesive based on polychloroprene rubber or the like has been used for these adhesions. However, the volatilization of the organic solvent used in these adhesives causes health problems for workers or fires in the workplace, and latex-based adhesives that do not have such concerns have been eagerly desired. It was.

Further, the conventional polychloroprene rubber latex has a problem that the adhesive strength is insufficient. As a method for solving this problem, for example, in JP-A-2000-104028 and JP-A-2003-27024, an adhesive containing polychloroprene latex as a main component and polyisocyanate as a cross-linking agent in adhesion to a foam is used. The bonding method is known. However, since the adhesive film is cured by isocyanate, there is a problem that the adhesive strength is improved, but the flexibility of the foam after adhesion is impaired.

Japanese Unexamined Patent Publication No. 2000-104028 Japanese Unexamined Patent Publication No. 2003-27024

The present invention has been made in view of this problem, and an object of the present invention is to provide sports goods or sports goods in which sufficient adhesive strength cannot be obtained or the flexibility is reduced by the conventional polychloroprene rubber latex-based adhesive. It is an object of the present invention to provide a polychloroprene rubber latex adhesive having good adhesive strength and flexibility in adhesion between foams as a material for a wet suit, or between a foam and a textile.

Against this background, as a result of diligent studies to solve the above problems, the present inventor has made a polychloroprene rubber latex by mixing an aqueous dispersion type isocyanate and a water-soluble carbodiimide compound with the polychloroprene rubber latex. We have found that it is possible to improve the adhesive strength between the adhesive containing the above as the main component and the foam, and have completed the present invention.

That is, the present invention is a polychloroprene rubber latex adhesive containing 1 to 4 parts by weight of water-dispersed isocyanate and 3 to 15 parts by weight of a water-soluble carbodiimide compound with respect to 100 parts by weight of polychloroprene rubber latex.

Hereinafter, the present invention will be described in detail.

The polychloroprene rubber latex adhesive in the present invention contains 1 to 4 parts by weight of a water-dispersible isocyanate compound and 3 to 15 parts by weight of a water-soluble carbodiimide compound with respect to 100 parts by weight of the polychloroprene rubber latex.

Various products of polychloroprene rubber latex are commercially available, and one or more selected from latex containing a homopolymer of chloroprene monomer, chloroprene monomer, and carboxyl group-containing monomer and hydroxyl group-containing monomer. There is a latex of a copolymer with a monomer and the like. 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 a polychloroprene rubber latex containing a copolymer with one or more kinds of monomers is preferable because the polychloroprene rubber becomes hard due to crystallization at low temperature.

The adhesive containing the polychloroprene rubber latex as a main component of the present invention needs to contain a water-dispersible isocyanate compound and a water-soluble carbodiimide compound in order to achieve both sufficient adhesive strength and flexibility. The water-dispersible isocyanate compound is a compound having a functional group represented by −N = C = O, and is water-dispersed by protecting them with an emulsifier. Carbodiimide is a compound having a functional group represented by −N = C = N−, and is generally synthesized by a decarboxylation reaction of diisocyanate in the presence of a carbodiimidization catalyst. A part of the carbodiimide compound is made hydrophilic or emulsified with an emulsifier or the like to form various forms such as water-soluble, emulsion type and water-dispersed type, and various commercial products exist. In the present invention, a water-soluble substance that dissolves in water is used.

The water-dispersible isocyanate compound used in the present invention is 1 to 4 parts by weight, more preferably 1.5 to 3.0 parts by weight, based on 100 parts by weight of the polychloroprene rubber. If the amount of the water-dispersed carbodiimide compound is less than 1 part by weight, the adhesive property is lowered, and if it exceeds 4 parts by weight, the flexibility of the adherend is lowered. The water-soluble carbodiimide compound is 3 to 15 parts by weight, more preferably 4 to 12 parts by weight, based on 100 parts by weight of the polychloroprene rubber. If the amount of the water-dispersed carbodiimide compound is less than 3 parts by weight or more than 15 parts by weight, the adhesive property deteriorates.

The viscosity of the adhesive containing polychloroprene rubber latex as the main component is determined by various thickeners, for example, water-soluble polymers such as polyalkylene oxide, polyvinyl alcohol, hydrophobic cellulose, associative nonionic surfactant, and carboxyl group-containing polymers. The desired viscosity can be adjusted by blending an alkali-soluble thickener composed of, a silicate compound such as Hectrite, and the like. If necessary, tackifying resins such as rosin ester, terpenphenol, petroleum resin, and kumaron resin, antiaging agents, preservatives, antifreeze agents, film-forming aids, plasticizers, pH adjusters, etc. are appropriately added. You may.

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

Examples of the sports goods and other foams in the present invention 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 wet suits.

Textiles in the present invention include synthetic fibers such as nylon and polyester, and non-woven fabrics made of natural fibers such as cotton and silk, but jerseys having a water-repellent effect are used for wet suits.

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

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

The normal temperature peel strength and flexibility in the examples were measured and evaluated by the following methods.
<Measurement of normal temperature peel strength>
The adhered 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 ends of each adherend were attached to a Tencilon type tensile tester, and a 180 ° peeling test was carried out at 23 ° C. under the condition of a tensile speed of 20 mm / min, and the peeling state was observed and the peeling strength was measured.

The peeled state was judged as follows.

(Good) Material fracture (material fracture)> Aggregate fracture (aggregate)> Interface fracture (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 Tencilon 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
Polychloroprene rubber latex (chloroprene / methacrylic acid copolymer manufactured by Tosoh Co., Ltd., trade name: Skyperene GFL-890) 100 parts by weight, water-dispersed isocyanate compound (manufactured by Tosoh Co., Ltd., trade name: Coronate AQ-140) ) 2 parts by weight, water-soluble carbodiimide compound (manufactured by Nisshinbo Chemical Co., Ltd., trade name: carbodilite V-04, active ingredient 40%) 4 parts by weight, and association type viscosity modifier (manufactured by Adeca Co., Ltd., trade name:) Adecanol UH-438) 2.5 parts by weight was uniformly mixed with a homomixer to prepare an adhesive composition. The adhesive was applied to a CR sponge piece at about 100 g / m ² (wet), a water-repellent nylon jersey was layered without wrinkles, and ^{pressed and dried at 0.5 kg / m 2} in an oven at 110 ° C. for 1 minute. .. Table 1 shows the composition and evaluation results of the prepared sample.

In the peeling test, the sponge material was mainly broken, the normal temperature peeling strength 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 water-dispersed isocyanate to be mixed was changed to the amount shown in Table 1. In the peeling test, the sponge broke, and both normal temperature peeling strength and flexibility were good.

Examples 3-5
An adhesive composition was prepared and evaluated according to Example 1 except that the weight of the water-soluble carbodiimide to be mixed was changed to the amount shown in Table 1. In the peeling test, the sponge broke, and both normal temperature peeling strength and flexibility were good.

Comparative Example 1
An adhesive composition was prepared and evaluated according to Example 1 using only water-dispersed isocyanate without using water-soluble carbodiimide in the amount shown in Table 2. The peeled state became cohesive fracture, the tensile stress increased, and the flexibility was inferior.

Comparative Example 2
An adhesive composition was prepared and evaluated according to Example 1 except that only the water-soluble carbodiimide compound was used in the amount shown in Table 2 without using the water-dispersed isocyanate. The flexibility was good, but the interfacial fracture of the adhesive was the main factor, and the peel strength at room temperature was inferior.

Comparative Example 3
An adhesive composition was prepared and evaluated according to Example 1 except that the amount of water-dispersed isocyanate was used in the amount shown in Table 2. The flexibility was good, but the adhesive was mainly coagulated and broken, and the peel strength at room temperature was inferior.

Comparative Example 4
An adhesive composition was prepared and evaluated according to Example 1 except that the amount of water-dispersed isocyanate was used in the amount shown in Table 2. The sponge broke and there was no problem with the peeling strength at room temperature, but the flexibility was inferior.

Comparative Example 5
An adhesive composition was prepared and evaluated according to Example 1 except that the amount of the water-soluble carbodiimide compound was used in the amount shown in Table 2. The peeled state became cohesive fracture, the tensile stress increased, and the flexibility was inferior.

Comparative Example 6
An adhesive composition was prepared and evaluated according to Example 1 except that the amount of the water-soluble carbodiimide compound was used in the amount shown in Table 2. Due to the thickening, the viscosity of the adhesive was high, poor adhesion was partially observed, and the peel strength was also reduced.

Comparative Example 7
An adhesive composition was prepared and evaluated according to Example 1 except that the carbodiimide compound was changed to an aqueous dispersion type carbodiimide compound (manufactured by Nisshinbo Chemical Co., Ltd., trade name: carbodilite E-05, active ingredient 40%). The peel strength at room temperature was good, but the flexibility was inferior.

Comparative Example 8
An adhesive composition was prepared and evaluated according to Example 1 except that the carbodiimide compound was changed to an emulsion type carbodiimide compound (manufactured by Nisshinbo Chemical Co., Ltd., trade name: carbodilite E-02, active ingredient 40%). Poor adhesion was partially observed, and the peel strength at room temperature was also inferior. Also, the flexibility was low.

Claims (7)

A latex adhesive composition containing 1 to 4 parts by weight of water-dispersible isocyanate and 3 to 15 parts by weight of a water-soluble carbodiimide compound with respect to 100 parts by weight of polychloroprene rubber latex. The latex adhesive according to claim 1, wherein the polychloroprene rubber in the latex is a copolymer with one or more monomers selected from a carboxyl group-containing monomer and a hydroxyl group-containing monomer. Composition. The latex adhesive composition according to claim 1 or 2, wherein the content of the water-dispersible isocyanate compound is 1.5 parts by weight to 3.0 parts by weight. The latex adhesive composition according to claim 1 or 2, wherein the content of the water-soluble carbodiimide compound is 4.0 parts by weight to 12 parts by weight. An adhesive in which the foams or the foam and the textile are adhered to each other with the latex adhesive composition according to any one of claims 1 to 4. The adhesive according to claim 5, wherein the material of the foam is polychloroprene rubber. A wetsuit made of the adhesive according to claim 5 or 6.