CS209161B1 - A method for producing a rubber product with a patterned surface - Google Patents

Abstract

The invention relates to a method for producing rubber products with a patterned surface, produced by dipping and precipitation on molds. The method according to the invention can be used to obtain rubber products with a finely roughened to coarsely wrinkled surface in a simple way, whereby these products are given an anti-slip treatment and their appearance is improved. The patterns obtained are regular on the entire surface of the products, even those with complex shapes, some patterns are also new types, thereby enriching the range of patterns. The essence of the surface treatment method according to the invention consists in precipitating a latex layer of such a gel-like consistency that has sufficient cohesion and remains malleable for several minutes and in the subsequent action of a mixture of solvents with a swelling and precipitation effect. The required ! properties of the precipitated film can be achieved by treating the latex mixture with the addition of surface-active non-ionic substances, which partially cancel the coagulation effects and thus affect the consistency of the resulting film. The actual patterning takes place during immersion in a solvent bath. The method can be applied to rubber products produced by dipping into latex mixtures using the coagulation and thermosensitive methods, or even to products dipped onto a textile insert.

Description

(54) A method for producing rubberized surface products

The present invention relates to a process for the manufacture of embossed surface rubber articles produced by dipping and molding. With the method according to the invention, rubber products having a finely roughened to coarse-wrinkled surface can be obtained in a simple way, thereby obtaining an anti-slip treatment and improving their appearance. Obtained designs are regular on the entire surface of products and complex shapes, some designs are also a new type and thus enrich the range of designs.

The essence of the surface treatment method according to the invention consists in the precipitation of a latex layer of a gel-like consistency having a sufficient content ^; and yet remains ductile for several minutes and subsequently treated with solvent swelling and clotting mixtures. Required ^! The properties of the precipitated film can be achieved by treating the latex mixture with the addition of nonionic surfactants, which partially cancel the coagulation effects and thereby affect the consistency of the resulting film. The actual design takes place when immersed in the solvent bath.

The method can be applied to rubber products made by dipping into latex mixtures by the coa and thermosensitive method, and possibly also to products soaked on a textile insert.

2

209161. . . ______________

The invention relates to a process for the manufacture of rubber; products with embossed surface, produced by dipping into latex mixtures and precipitation on even molds. 5

At present, the design of the dipped rubber products 5 is obtained, in particular, by imprinting the design with the mold to which it is soaked. When soaking on plain molds (or on a textile insert), a rough surface can be obtained, for example, by suspending solid particles in the latex mixture, mostly in the second shoulder. Another way is to roughen the surface after swelling with solvents, which is conditioned by pre-soaking in two latex mixtures of different composition. The method used previously was granulation of the surface of the latex films precipitated from the mixture, not containing the accelerator of the vulcanization process, which after drying were soaked in the hot bath with both water soluble and accelerator and then in the bath of organic solvents.

The aforementioned drawbacks are overcome by the process for the production of the embossed-surface rubber products according to the invention, which is characterized in that the mold is soaked in a latex mixture with an addition of 0.1 to 2.0. 1 wt. a portion of a non-ionic surfactant;

, preferably the condensation products of higher alcohols 5 or higher fatty acids with alkylene oxides; especially ethylene oxide per 100 wt. parts pevné- rubber and it then the resulting latex film 5 with an organic gel-like consistency rozpouš- 5 may thus be placed, preferably chlorinated hydrocarbon or _(j hydrocarbons, with addition of trace -5% acetic acid.

The effect achieved by the method according to the invention lies primarily in the simplicity of the embodiment.

Smooth molds can also be used for dipping, with the products easily contracting, these molds being considerably less soiled as compared to the embossed molds, becoming more versatile, since they can produce smooth products with a finely to coarse embossed surface. Roughening or wrinkling of the surface gives the products a non-slip finish and improves their appearance. Rough, plastic designs are also a new type of designs. The method can also be applied to articles soaked on a textile insert. When dipped to the embossed molds, products with double-sided design can be obtained.

The process of dipping with pre-soaking coagulation solution is as follows. The slightly preheated form is first wetted in a coagulant, which is most often an alcoholic or aqueous-alcoholic solution of calcium salts. After the coagulant has dried on the mold, it is soaked in a latex mixture. The effect of the coagulant precipitates on the mold surface a stronger "carrier" layer of latex film which ensures its strength, prevents film cracking and later reduces the possibility of "puncture" of the film under the action of solvent. This film passes away from the mold in the presence of the above-mentioned surfactants! substances that partially disrupt the coagulation effects of calcium salts into a semi-solid ductile gel, which remains in this state for several minutes and very well even compensates for different clotting conditions at different 5 surface areas of more complex shapes (eg gloves) basic prerequisite for the creation of a uniform design. On the surface of this gel-like layer due to drying, sometimes even intentionally at higher temperatures, weaker or stronger "crust" arises, which also significantly affects the character of the design. The thicker, dry layer on the gel-like base allows for the formation of deep, plastic designs; a slightly dried film gives a smaller, sharper design.

The actual surface treatment by roughening or wrinkling takes place only when the latex film is immersed in the solvent mixture. The solvent mixture consists of hydrocarbons or chlorinated hydrocarbons and a minor amount of acetic acid. Hydrocarbons have swelling effects, acetic acid precipitates. Due to the effect of the hydrocarbons on the gel-like, non-dry, latex film, it is only diluted with the solvent and begins to drip off the molds, and the film precipitates smoothly with acetic acid. It is only by the action of the solvent mixture that both the precipitation and the swelling coincide and the desene is formed. A lower concentration of acetic acid results in a deeper design, while a higher concentration of shallower designs. The action of a solvent with swelling effect is sufficient to wrinkle latex films with a dry surface layer on a gel-like surface, but the addition of even less acetic acid has a very favorable effect on the uniformity of the resulting desene. The roughness of the desenes and their quality is also influenced by the presence of acidic or neutral inorganic salts, preferably chlorides. Upon removal from the solvent bath, the surface of the latex film is strong enough to carry out other operations conventional in dipped rubber technology - scouring, drying, vulcanizing, scaling and stripping, and finishing.

In applying this method, on thermosensitive soaking technology, a stronger latex film backing precipitates on the surface of the preheated mold under the effect of heat. Similarly, it becomes gel-like away from the mold and a more solid film can be formed on the film surface by drying. The thermosensitive method enables, in addition to fine designs, the formation of deeply creased designs, especially in the case of thicker products.

The method of the invention is illustrated by two exemplary embodiments:

Components used in Example 1:

Kqagulant:

Ethanol 80 wt. parts

Calcium nitrate 20 wt. parts

Sodium lauryl sulfate (wetting agent) 0.3 wt. Parts'

Latex mixture

Latex low ammonia 167 wt. parts content. 60 wt. natural rubber (100 parts dry matter)

Sulfur ground 1.1 parts by weight

Zinc diethyldithiocarbamate 1.1 wt. parts

Sodium methylbis-naphthalenesulfonate

Polyglycol ether Ammonium chloride Distilled water

0.2 wt. parts 0.3 wt. 0.2 parts by weight. 60 wt. parts

Solvent bath

Petrol (boiling point 90 to 150 ° C) 97 wt. Acetic acid 3 wt. parts

The formation of a fine thin-film design when applying the method of the invention to roughened surgical gloves:

The glove porcelain mold, preheated to 60-70 ° C, is soaked in the coagulant. After the coagulant has dried on the mold, it is soaked in a latex mixture, where it coagulates for about 40 s. After removal, the mold surface is allowed to dry slightly at 40 to 50 ° C for about 3 minutes, preferably with rotation of the mold. It is then soaked in a solvent bath, where within 15 to 20 sec. the film surface is roughened.

Components used in the 2nd embodiment:

Coagulant

Ethanol

Calcium nitrate Sodium lauryl sulphate

Latex mixture Latex of low ammonia mass. 30 wt. parts, 0.3 wt. parts

167 wt. parts content. 60% natural rubber

Sulfur ground

Zinc diethyldithiocarbaman

Sodium methylbis-naphthalenesulfonate

Polyglycol ether Ammonium chloride Distilled water or dye of your choice (100 parts dry matter) 1.1 wt. parts 1.1 wt. parts

0.2 wt. parts 0.4 wt. parts _0.4 wt. 20 wt. parts

Toluene solvent bath

Acetic acid mass parts 2 wt. parts

Formation of coarse, plastic wrinkles on a thicker film when applying the method according to the invention to technical gloves:

The glove mold preheated to 60-70 ° C is urinated in a coagulant. After the coagulant has dried, it is soaked in a latex mixture where it coagulates for 10 minutes. The film coating is then allowed to dry at 80 to 90 ° C, preferably from air circulation and mold rotation for about 4 minutes. This is followed by soaking in a solvent bath, where within 30 to 60 seconds the surface becomes wrinkled.

Claims (1)

SUBJECT A process for the production of embossed surface rubber products produced by dipping and precipitation on molds, characterized in that the mold is soaked in a latex mixture in which it is added to 100 wt. parts of solid rubber 0.1 to 1 wt. Nonionic surfactants, preferably the condensation products of higher alcohols or higher OF THE INVENTION of fatty acids with alkylene oxides, in particular ethylene oxide, after which the resulting gel-like latex film is treated with an organic solvent, preferably hydrocarbons or chlorinated hydrocarbons, with an addition of - traces of up to 5% acetic acid.