JPH0753808B2 - Surface treatment method for rubber products - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a surface treatment method for a rubber product made of synthetic rubber including natural rubber and gen-based rubber,
More specifically, it relates to a method for obtaining a rubber product having non-stickiness and lubricity.

[0002]

2. Description of the Related Art Conventionally, the method for treating the surface of a rubber product made of synthetic rubber including natural rubber and gen-based rubber is (1) adding chlorine to the surface (chlorination), (2) solvent treatment Surface degreasing, (3) Surface oxidation such as strong acid treatment, plasma treatment, corona treatment, (4) Surface roughening by blast treatment, (5) Silica, talc, starch powder adhesion,
(6) There was adhesion of resin such as silicone and fluororesin.

[0003]

However, these methods are labor-intensive, and the use of harmful substances and strong oxidants lowers the work environment and increases the cost of equipment due to the use of high energy. There was a problem.

Further, regarding the chlorinated product, water marks may remain on the rubber product depending on the drying condition after washing, and the chlorinated product may harden the surface of the rubber to cause minute cracks. There was also a problem.

Regarding the adhesion of resin to the surface, the natural and synthetic rubbers, which are the raw materials of these rubber products, have few functional groups because of their composition, so that the resin can adhere to the surface, but the adhesive force There was a drawback that was weak

Further, silicone oil, powder, etc. have the drawback that they are removed from the rubber surface after a short time of use to give a sticky feeling, and other synthetic resins also have an emulsion powder diameter of 0.05 to 0.2. Because of μ, the rubber product adheres in a static state, but since the rubber surface is a microscopic uneven surface, when the rubber product is stretched, cracks occur and it is easily peeled off and partially removed. It was difficult to use for a long time.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. The means is to coat a surface of a rubber main body with an acrylic microemulsion of a hydrosol type water-soluble resin, It is to provide a dry film.

[0008]

EXAMPLES Examples of the present invention will be described. The rubber body is made of various rubber products such as a rubber film, a finger sack, which are known in this technical field and are made of synthetic rubber including natural rubber and gen rubber. Nipples, dry suits, boots, rubber frames for automobiles, wiper blades, medical devices (drage bag, catheter balloon, urethral catheter,
Condoms), tubes, packing rubber, rubber bands, gloves, etc., which are obtained by well-known manufacturing methods such as dipping method and extrusion method. Hydrosol-type water-soluble resin is applied to the outer surface, inner surface or inner / outer surface thereof. The acrylic microemulsion (1) is applied by an arbitrary method such as coating, spraying or dipping, and dried to form a film on the surface.

The composition of the acrylic microemulsion of the hydrosol type water-soluble resin is composed of a copolymer of methacrylic acid ester monomer and acrylic acid ester monomer, and the factors selected as the monomer are hydrophilic, Considering high reactivity, adhesiveness, low friction coefficient, etc., as monomers having good performance, methacrylic acid, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, decylaminoethyl are used. Methacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, methyl methacrylate, 2-
Ethylhexyl methacrylate and the like, and particularly high-performance monomers are methacrylic acid, 2-hydroxyethyl methacrylate, 2-ethylhexyl methacrylate and the like. It is also possible to use these as basic monomers of the copolymer and to use them in combination with other monomers.

Further, in the present invention, it is necessary to adjust the solution concentration of the acrylic microemulsion so as to be suitable for each rubber main body, and the range of 0.1 to 20% is suitable, and the usual rubber product has a concentration of 0.5 to 20%. 10% can be more effective.

The above-mentioned hydrosol type water-soluble resin acrylic microemulsion has a particle size of 0.05 μm or less, and the central value of the particle size is 0.02 μm or less. On the other hand, the emulsion particles can sufficiently enter.

In order to improve the solvent resistance, heat resistance and water resistance of such an emulsion, water-soluble melamine, epoxy resin or the like is added as a crosslinking agent, and organic amines or ammonium salts are added as catalysts. The surface of the rubber body is dipped in the surface treatment agent, or the surface treatment agent is sprayed or coated on the surface.

An example of the formulation of the surface treatment agent is as follows: 100 to 40,000 parts of water, 1 to 4 parts of water-soluble melamine, 0.1 to 4 parts of organic amine catalyst per 100 parts by weight of acrylic microemulsion (40%). 0.4 copies. The coating amount should be taken into consideration when it is dried to form a film, but it should be formed as thin as possible so as not to change the texture of the rubber product.

Next, specific embodiments and comparative examples (conventional methods) will be described in detail. Example 1 and Comparative Example 1 A rubber tube is formed from the natural dry rubber compound shown in Table 1 by an extrusion method and processed by the steps shown in Table 2. The compounding example of the surface treatment agent in Example 1 is 100 parts by weight of acrylic microemulsion (solid content 40%) and water.
300 parts, 2 parts of water-soluble melamine and 0.2 part of organic amine catalyst were added.

Natural rubber 100 parts by weight S 2 parts by weight ZnO 3 parts by weight TET 1 part by weight TMT 0.5 part by weight Stearic acid 1 part by weight Anti-aging agent 1 part by weight

[0016]

[Table 1]

Example 2 and Comparative Example 2 A balloon catheter was formed by dipping in the natural rubber latex composition shown in Table 3 and processed by the steps shown in Table 4. The surface treatment agent in Example 2 has the same composition as in Example 1.

Natural rubber latex (DRY) 100 parts by weight S 1 parts by weight ZnO 1 part by weight Dithiocarbamate vulcanization accelerator 0.8 parts by weight Anti-aging agent 1 part by weight Stabilizer suitable amount

[0019]

[Table 2] Next, Table 5 shows physical properties and performance tables of the film prepared by blending the natural rubber latex shown in Table 3 with the surface-treating agent in Example 1 and the untreated film.

[0020]

[Table 3]

[0021]

INDUSTRIAL APPLICABILITY According to the present invention, the surface of the rubber body is coated with the acrylic microemulsion of the hydrosol type water-soluble resin to form a dry film, so that not only the non-adhesiveness and lubricity but also these are improved. You get what you did,
In addition, it is extremely simple as compared with the conventional method without requiring pretreatment, and it is free from peeling during use and elongation.

That is, the hydrosol-type water-soluble acrylic microemulsion has a particle size of 0.05 μm or less, and the emulsion particles sufficiently enter and adhere to the microscopic unevenness of the rubber surface to form a strong film, which forms a rubber. It can be permanently formed on the surface of the product, and since it does not use powder or the like, it is not contaminated or removed during use.

Claims (1)

[Claims] 1. The particle size is 0.05 μm or less on the surface of the rubber body.
Surface treatment method for rubber products, characterized by applying an acrylic microemulsion of hydrosol-type water-soluble resin with a median particle diameter of 0.02μ or less and forming a dry film