KR20090042923A - Vulcanizable aqueous adhesive and use thereof - Google Patents

Abstract

It provides a vulcanizable aqueous adhesive that does not use an organic solvent and is free of protein allergy.

It is a vulcanizable aqueous adhesive containing chloroprene latex, sulfur and zinc oxide. It is preferable that a vulcanized-type aqueous adhesive contains 2-5 mass parts of sulfur content and 3-10 mass parts of zinc oxide content with respect to 100 mass parts of solid content in chloroprene latex. The vulcanized water-based adhesive can be used for vulcanizing the rubber outsole of a canvas shoe, a foam upper, and a foxing tape.

Description

Vulcanizable Waterborne Adhesive and Its Uses {VULCANIZABLE AQUEOUS ADHESIVE AND USE THEREOF}

The present invention relates to a vulcanizable aqueous adhesive which can be preferably used for vulcanization and its use.

When manufacturing shoes by the valcanise manufacturing method, such as canvas shoes, the chloroprene solvent type adhesive agent and the natural rubber latex adhesive agent have been used. However, for solvent-based adhesives, the demand for development of alternative adhesives is increasing year by year from the viewpoint of environmental impact and worker safety and hygiene, and for natural rubber latex adhesives in terms of protein allergy of latex (for example, non-patent literature). 1, 2).

Non-Patent Document 1: Japanese Rubber Association, Vol. 78, No. 2 (2005) (Page 55; Section 4.2.1)

[Non-Patent Document 2] Techniques for Bonding Vol. 21, No. 4 (2002) Vol. 65 (p. 12; Section 2.1.4)

Disclosure of the Invention

Problems to be Solved by the Invention

An object of the present invention is to provide a vulcanized aqueous adhesive that does not use an organic solvent and that is free of protein allergy.

Means to solve the problem

As a result of intensive studies to achieve the above object, the present invention has reached the present invention having the following gist.

(1) A vulcanized aqueous adhesive comprising chloroprene latex, sulfur, and zinc oxide.

(2) The vulcanized aqueous adhesive according to the above (1), wherein the solid content concentration in the chloroprene latex is 40 to 70 mass%.

(3) The vulcanized aqueous adhesive according to the above (1) or (2), wherein 0.5 to 10 parts by mass of the emulsifier and / or dispersant are contained in the chloroprene latex based on the total monomers used to obtain the chloroprene polymer.

(4) The vulcanized aqueous adhesive according to any one of the above (1) to (3), which contains 2 to 5 parts by mass of sulfur and 3 to 10 parts by mass of zinc oxide with respect to 100 parts by mass of solids in chloroprene latex.

(5) The vulcanized aqueous adhesive according to any one of the above (1) to (4), which is used for the production of canvas shoes.

(6) The vulcanized aqueous adhesive according to any one of the above (1) to (4), which is used for vulcanizing two or more of rubber outsoles, canvas uppers, and foxing tapes of canvas shoes.

(7) Using the vulcanized aqueous adhesive according to any one of the above (1) to (4), vulcanizing and adhering two or more of rubber outsoles, foam uppers, and foxing tapes are manufactured. Way.

(8) The manufacturing method of canvas shoes as described in said (7) which apply | coats and heat-bonds a vulcanized aqueous adhesive with a coating amount of 100-300g / cm <2> with respect to an adhesive surface.

(9) The manufacturing method of the canvas shoes as described in said (7) or (8) which apply | coats a vulcanized aqueous adhesive, dries at 60-100 degreeC, compresses an application surface, and vulcanizes at 100-150 degreeC.

Effects of the Invention

Since the vulcanized aqueous adhesive of the present invention does not contain an organic solvent, it is environmentally friendly or human-friendly, and since synthetic rubber latex is used as a raw material, there is no fear of protein allergy. Moreover, since sufficient adhesive strength is expressed after vulcanization, it can be used suitably as a vulcanization type adhesive agent used for canvas shoes etc.

Best Mode for Carrying Out the Invention

Chloroprene latex is obtained by emulsifying / dispersing chloroprene polymer in water through an emulsifier and / or a dispersant (hereinafter also referred to as an emulsifier / or dispersant). Although the solid content concentration in chloroprene latex is not specifically limited, From a viewpoint of improving workability and stability of chloroprene latex itself, Preferably it is the range of 40-70 mass%, More preferably, it is the range of 50-60 mass%. Set to.

The chloroprene polymer is a homopolymer obtained by polymerizing 2-chloro-1,3-butadiene (hereinafter referred to as chloroprene) or a copolymer obtained by polymerizing monomers copolymerizable with chloroprene and chloroprene. The content of the polymerized unit of chloroprene in the copolymer is preferably 80 mol% or more, particularly 90 mol% or more.

Although it does not specifically limit as a monomer copolymerizable with chloroprene, For example, 2, 3- dichloro- 1, 3- butadiene, 1-chloro- 1, 3- butadiene, butadiene, isoprene, styrene, acrylonitrile, acrylic acid Or the ester, methacrylic acid or its ester, etc. are mentioned, You may use these two or more types together as needed. Especially, as a monomer which can be copolymerized, Preferably, it is 2, 3- dichloro- 1, 3- butadiene.

Although the structure of a chloroprene polymer is not specifically limited, Molecular weight, molecular weight distribution, gel content, molecular terminal structure, crystallization rate by selecting and controlling a polymerization temperature, a polymerization initiator, a chain transfer agent, a polymerization terminator, a final polymerization rate, etc. suitably. Etc. can be adjusted.

The emulsifier / dispersant used in the production of chloroprene latex is not particularly limited, and various kinds of anions, nonions, cationics and the like used in emulsion polymerization of conventional chloroprene can be used.

Examples of the anionic emulsifier / dispersant include a carboxylic acid type and a sulfuric acid ester type. Examples thereof include alkali metal salts of rosin acids, alkyl sulfonates having 8 to 20 carbon atoms, alkylaryl sulfates, sodium naphthalin sulfonate, and form. Condensate of an aldehyde, sodium alkyl diphenyl ether disulfonate, etc. are mentioned.

As nonionic emulsifying / dispersing agent, for example, polyvinyl alcohol (hereinafter PVA) or its copolymer (for example, copolymer with acrylamide), polyvinyl ether or its copolymer (for example, maleic acid and Copolymers), polyvinylpyrrolidone or copolymers thereof (for example, copolymers with vinyl acetate), or chemical modifications of these (co) polymers, or cellulose derivatives (hydroxyethyl cellulose) , Polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene alkyl phenyl ether, polyoxyalkylene alkyl ether, polyoxyethylene-acetylene glycol ether, sorbitan fatty acid ester and the like Can be mentioned.

Examples of the cationic emulsifier / dispersant include aliphatic amine salts and aliphatic quaternary ammonium salts, and examples thereof include octadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride and dilauryldimethylammonium chloride. .

Among these emulsifiers and dispersants, anionic type is preferable, and rosinate is particularly preferable. As rosin acid, any of wood rosin acid, gum rosin acid, tall oil rosin acid, or disproportionated rosin acid which disproportionate them can be used.

When using a rosin acid salt, in order to provide sufficient stability to chloroprene latex, it is preferable to use together an anionic emulsifier and a dispersing agent of a sulfate type or a sulfonate type.

0.5-10 mass parts is preferable with respect to 100 mass parts of all the monomers used for obtaining a chloroprene polymer, and, as for the usage-amount of an emulsifier / dispersant, 2-6 mass parts is more preferable.

Although sulfur is not specifically limited, Powder sulfur, precipitated sulfur, colloidal sulfur, etc. which are generally used as a vulcanizing agent of rubber | gum are used. In view of dispersibility, the use of finely divided sulfur is preferred. Considering the handling when added to chloroprene latex, sulfur is more preferably used as an aqueous dispersion. As a method of using sulfur as an aqueous dispersion, for example, conventional methods described in Adhesion Vol. 36, No. 8 (1992), Vol. 388 (p. 343; Section 3) and the like can be used.

Although content of sulfur is not specifically limited, 1-10 mass parts is preferable with respect to 100 mass parts of solid content in chloroprene latex, More preferably, it is 2-5 mass parts. When the addition amount of sulfur is set in this range, the adhesive strength after vulcanization adhesion becomes sufficient, and the bloom of sulfur is hardly generated.

Although zinc oxide is not specifically limited, Any zinc oxide generally used as a compounding compound for rubber | gum can be used. Specifically, there are one kind, two kinds, three kinds, active zincation, and the like. It is also preferable to use zinc oxide as an aqueous dispersion. The preparation method of the aqueous dispersion is described in the same manner as in the case of sulfur, as described in Adhesion Vol. 36, No. 8 (1992), Vol. 388 (p. 343; Any conventional method may be used. Moreover, the product marketed as an aqueous dispersion of zinc oxide can also be used.

Although content of zinc oxide is not specifically limited, 1-10 mass parts is preferable with respect to 100 mass parts of solid content in chloroprene latex, More preferably, it is 3-10 mass parts, Especially preferably, 3-7 mass parts to be. When the addition amount of zinc oxide is set in this range, while the adhesive strength after vulcanization adhesion becomes sufficient, it becomes difficult to separate adhesive agent itself.

The vulcanized aqueous adhesive includes a tackifying resin, a thickener, a metal oxide other than zinc oxide, a filler, a film forming aid, a ultraviolet absorber, an antioxidant, a plasticizer, a vulcanizing agent other than sulfur, a vulcanization accelerator, Defoamer etc. can be added arbitrarily.

Although the use of the vulcanized aqueous adhesive is not particularly limited, it is possible to adhere various materials such as cement, mortar, slate, foam, wood, synthetic rubber material, polyurethane material, polyvinyl chloride material, and polyolefin material. Can be preferably used. In particular, it can use suitably as a vulcanized adhesive at the time of manufacturing canvas shoes.

In order to manufacture canvas shoes with a vulcanized water-based adhesive, the following can be performed.

First, a fabric upper part is made upper by sewing, pull bonding, etc. Subsequently, the upper is joined to the bottom and bottom by a so-called lasting operation and shaped. A vulcanized water-based adhesive is applied to each of the adhered surfaces of the formed foam upper, the rubber outsole, and the rubber foxing tape. In order to ensure sufficient adhesive strength and prevent it from protruding from the interface, the coating amount at this time is preferably 100 to 300 g / cm 2, particularly preferably 150 to 250 g / cm 2. . The material to which these vulcanized aqueous adhesives are applied is dried at 60 to 100 ° C, preferably at 70 to 90 ° C for 5 to 30 minutes, bonded to each other so as to be in contact with the coated surfaces, and sufficiently compressed, and then 100 to 150 ° C, preferably It is preferable to vulcanize and complete at 120-140 degreeC for 0.5 to 2 hours.

Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, these Examples do not limit the interpretation of this invention. In addition, unless otherwise indicated in the following description, a part and% are shown on a mass basis.

"Example 1"

[Polymerization Example 1]

In a nitrogen atmosphere, in a nitrogen atmosphere, in a nitrogen atmosphere, 5 parts of disproportionated rosin acid, 0.5 parts of sodium hydroxide, 0.8 parts of potassium hydroxide, 0.5 parts of sodium salt of formaldehyde-naphthalenesulfonic acid condensate, sodium hydrogen sulfite 0.5 parts were dissolved. While stirring, 100 parts of chloroprene monomer and 0.14 part of n-dodecylmercaptan were added. Potassium persulfate was polymerized as an initiator at 10 ° C. under a nitrogen atmosphere, and an emulsion of phenothiazine was added to terminate the polymerization when the polymerization rate reached 90%. The mixture was heated under reduced pressure to remove unreacted monomer, and then concentrated to 50% solids to obtain chloroprene latex.

[Preparation of Sulfur Aqueous Dispersion]

100 parts of powdered sulfur, 5 parts of 20% by mass aqueous solution of sodium dodecylbenzenesulfonate, 1 part of bentonite, 10 parts of 5% by mass aqueous sodium hydroxide solution, and 184 parts of pure water were added to a ball mill and stirred and mixed for one day to prepare 33% by mass of aqueous dispersion of sulfur. It prepared.

[Preparation of Vulcanized Water-Based Adhesive]

To 200 parts of chloroprene latex obtained in Polymerization Example 1 (100 parts by dry basis), 3 parts of aqueous dispersion of sulfur (1 part by dry basis) obtained above, an aqueous dispersion of zinc oxide (AZ-SW manufactured by Osaki Industries, Ltd., zinc oxide) 2 parts (containing 50 parts by mass) (1 part on dry basis) were added. Next, an acrylic thickener (Aaron A-20L manufactured by Toa Synthetic Co., Ltd.) was added, and the viscosity was prepared at about 3,000 mPa · s to obtain an adhesive.

[Adhesion test]

The obtained adhesive agent was apply | coated to the natural vulcanized rubber sheet (20x120 mm) and canvas (20x120 mm). After drying at 90 ° C. for 2 minutes, the unvulcanized rubber sheet and the canvas were bonded together. The bonded adherend was vulcanized in a vulcanized kiln at 120 ° C. for 1 hour.

The to-be-adhered body after vulcanization measured peeling strength at the tensile speed of 200 mm / min after standing at room temperature for 24 hours.

[Examples 2 to 5]

Except having changed the usage-amount of the aqueous dispersion of sulfur and the aqueous dispersion of zinc oxide as shown in Table 1, it tested like Example 1 and set it as Examples 2-5.

Comparative Example 1

Except having changed the usage-amount of the aqueous dispersion of sulfur and the aqueous dispersion of zinc oxide as shown in Table 1, it tested similarly to Example 1 and set it as the comparative examples 1-3.

From the comparison of the Example and comparative example shown in Table 1, it turns out that the vulcanized-type aqueous adhesive agent of this invention shows the outstanding adhesive strength.

In Table 1, MF shows that the material destruction of the rubber sheet was confirmed, mf means that material destruction was confirmed to a part of the rubber sheet, and AC indicates that interfacial peeling and cohesive failure of the adhesive surface were confirmed.

The vulcanized aqueous adhesive obtained by the present invention is a vulcanized adhesive used for canvas shoes and the like, which exhibits sufficient adhesive strength in the absence of an organic solvent and in which the risk of protein allergy due to natural rubber latex is also suppressed. It can be used suitably as.

In addition, all the content of the specification, the claim, drawing, and the abstract described in Japanese Patent Application No. 2006-230000 for which it applied on August 28, 2006 is referred here, and it introduces as an indication of the specification of this invention.

Claims (9)

A vulcanizable aqueous adhesive comprising chloroprene latex, sulfur, and zinc oxide. The method of claim 1, The vulcanized aqueous adhesive whose solid content concentration in a chloroprene latex is 40-70 mass%. The method according to claim 1 or 2, The vulcanized aqueous adhesive containing 0.5-10 mass parts of emulsifiers and / or dispersing agents with respect to the total monomer used for obtaining a chloroprene polymer in chloroprene latex. The method according to any one of claims 1 to 3, A vulcanized aqueous adhesive containing 2 to 5 parts by mass of sulfur and 3 to 7 parts by mass of zinc oxide with respect to 100 parts by mass of solids in chloroprene latex. The method according to any one of claims 1 to 4, Vulcanizable aqueous adhesive used in the manufacture of canvas shoes. The method according to any one of claims 1 to 4, A vulcanized water-based adhesive used for vulcanizing two or more of rubber outsoles of canvas shoes, cloth uppers, and foxing tapes. The vulcanized aqueous adhesive according to any one of claims 1 to 4 is used to vulcanize two or more of rubber outsoles, foam uppers, and foxing tapes. The method of claim 7, wherein The manufacturing method of the canvas shoe which apply | coats and heat-bonds a vulcanized aqueous adhesive with a coating amount of 100-300 g / cm <2> with respect to an adhesive surface. The method according to claim 7 or 8, The manufacturing method of the canvas shoes which apply | coat a vulcanized aqueous adhesive, dry at 60-100 degreeC, crimp a coating surface, and vulcanize at 100-150 degreeC.