RO120346B1 - Polychloroprene adhesive - Google Patents

Abstract

The invention relates to a monocomponent polychloroprene adhesive used in leather and footwear industry, furniture and textile industry, for gluing macro and micro-porous surfaces of leather, textile materials, plastics or elastomeric materials, to each other and to various supports. According to the invention, the adhesive consists of polychloroprene polymer, butadiene-styrene or butadiene-alpha-methyl styrene copolymer, thermoreactive phenolic resin, silicon dioxide, with the BET specific surface of 200 m2/g and the grain size less than 40 mium, and oxides of the metals of the IInd group of the periodical system, natural calcined pulverous mordenite, in a solvent mixture consisting of C6-C8 aliphatic hydrocarbons, C3-C6 lower ketones, acetic esters of the C2-C4 alcohols, alkylaromatic hydrocarbons, the dry substance content being of minimum 15% in the final product.

Description

The invention relates to a monocomponent chloroprene adhesive, with low pollutant potential, used in the footwear and leather goods industry, in the textile industry and in the furniture industry, for bonding the macro- and microporous surfaces of leather, textile materials, plastics and elastomeric materials between them and on different supports.

Several adhesive compositions, containing chloroprene, mixed with various synthetic resins, metal oxides and antioxidants, which, depending on type and the proportion of the mixture, gives the adhesive composition a certain destination. The adhesive composition is obtained as a solution in a solvent mixture consisting of ketones, lower esters, aliphatic hydrocarbons and aromatic hydrocarbons.

Also, patent RO 91427 describes an adhesive composition based on polychloroprene rubber with a strong tendency to crystallize, hydrated silica, modified phenolic resins and usual antioxidant, dissolved in a mixture of solvents such as toluene and ethyl acetate.

Patent R0113565 discloses a two-component adhesive composition used for joining conveyor belts and bonding elastomeric films to metals. One component of the adhesive comprises polychloroprene rubber, chlorinated rubber, 2-2 methylbisbis 4-methyl-6-tert-butylphenyl], MgO, ZnO, SiO ₂ , S, detetramethylthiuram disulphide, stearin, epoxy resin, tricloethylene and triacloetylene. .

These compositions have a number of disadvantages;

- limited applicability, each composition being designed for a particular domain;

- high inorganic load, which raises problems of stability of the adhesive composition;

- the presence in the adhesive composition in large quantities of some aromatic hydrocarbons which are difficult to biodegrad and potentially carcinogenic.

A polychloroprene adhesive, which also contains asbestos powder, a product with high carcinogenic potential, whose use has been drastically restricted in all areas, is known from patent RO 109746.

The problem solved by the invention is to provide a composition with superior adhesive properties and low pollutant potential, which can be used for a wide range of bonding media.

The adhesive according to the invention contains 100 parts by weight of polychloroprene polymer, 1-5 parts butadiene-styrene or butadiene-a-methyl-styrene copolymer, 20-45 parts thermoreactive phenolic resin, 0.5-6 parts silica dioxide with specific BET weight. approx. 200 m ^z / g and granulation below 40 mp, 0.5-2% naturally powdery mildew, calcined at over 280 ° C, 1-10 oxide parts of metals in the I-group of the periodic system, which dissolve and dissolve. homogenizes in a solvent mixture consisting of 40-60 parts aliphatic hydrocarbons C ₆ .C ₈ , 10-30 parts lower ketones C ₃ -C ₆ , 10-40 parts acetic esters of alcohols C ₂ -C ₄ , 6-12 parts of alkylaromatic hydrocarbons, the dry matter content of the finished product being at least 15%.

Optionally, 0.5-2 parts by weight of alkylphenolic type antioxidant, selected from 2,6-d / -f-butyl-4-cresol, 2.6 - (// - f-butyl-) may be added to the adhesive. 4- (4,6-b / 's (octylthio) 1,3,5-triazin-2-ylamino) phenol, 4,6-b / s (octylthiomethyl) -2-cresol, 4,6-b /' s (dodecylthiomethyl) -2-cresol or other similar compounds.

The adhesive according to the invention has the following advantages:

- superior adhesive properties;

- wide range of uses of adhesive composition;

- simple application technology;

- low content in carcinogenic components and heavy biodegradation;

- eliminates the danger of occupational diseases;

- good stability over time.

RO 120346 Β1

The addition of butadiene-styrene or butadiene-methyl-styrene copolymer increases the adhesiveness of the adhesive composition, according to the invention, to the less porous surfaces and reduces the amount of adhesive that is absorbed on the highly porous surfaces. In this way, it increases the range of uses of the adhesive and reduces the consumption of adhesive for certain uses. In addition, the combination of silicon dioxide with the specific BET weight of approx. 200m ² / g and naturally powdered 5 mordenite, calcined, due to thixotropic properties, ensures a high stability to the adhesive according to the invention. 7 a non-limiting example of embodiment of the invention is provided below.

In an autoclave type reactor with a thermostat and a mechanical shaker with a speed of 9 to ensure a peripheral speed of at least 0.4 m / s, 200 parts by weight of extraction gasoline, fraction 80-120, 90 parts are introduced in weight acetone, 155 parts by weight 11 ethyl acetate, in which stirring is added, at room temperature, 3 parts by weight zinc oxide, 100 parts by weight polychloroprene rubber, 3 parts by weight copolymer buta-13 diene-styrene in 15 parts toluene, 26 parts by weight thermoreactive phenolic resin in 30 parts toluene, 2 parts by weight silicon dioxide with BET specific surface area of 200 m ² / g, 1 part 15 natural mordenite calcined at 290 ° C and 0.5 parts in antioxidant weight alkylphenolic. Homogenize for a minimum of 3 hours under thermostat at 25-30'C. 17

The adhesive obtained, containing 21.6% dry matter, has a viscosity of 78 s. In the Ford cup with the 8 mm nozzle. The adhesive has good rheological properties, good stability 19 in time, high initial adhesion, short film drying time and high resistance to sticking. 21

Claims (2)

Claims 23 1. One-component, non-polluting polychloroprene adhesive, used in the shoe industry - 25 minds and leather goods, in the textile industry and in the furniture industry, for bonding the macro- and microporous surfaces of leather, textile materials, plastics and elastomeric materials between 27 and on supports. different, based on polychloroprene polymer, thermoreactive phenolic resin, silicon dioxide and metals oxides of group II of the periodic system, in a mixture of 29 solvents, characterized in that 100 parts by weight of polychloroprene polymer, 1- 5 parts butadiene-styrene or butadiene-a-methyl-styrene copolymer, 20-45 parts thermo-reactive phenolic resin, 0.5-6 parts silicon dioxide with the specific BET surface of approx. 200 m ² / g and granulation below 40 sqm, 0.5-2% naturally powdery mildew, calcined at over 280 ° C, 1-10 oxide parts 33 of the metals in group III of the periodic system, dissolve and dissolve homogenizes in a solvent mixture consisting of 40-60 parts C ₆ -C ₈ aliphatic hydrocarbons, 10-30 lower ketones 35 C ₃ -C ₆ , 10-40 parts acetic esters of C ₂ -C ₄ alcohols, 6- 12 parts alkylaromatic hydrocarbons, the dry matter content of the finished product being at least 15%. 37 A single component polychloroprene adhesive according to claim 1, characterized in that 0.5-2 parts by weight of an alkylphenolic type antioxidant, selected from 39 2,6-d / '- t-butyl-4-cresol, 2 is added. 6-c // - butyl-4- (4,6-bis (octylthio) 1,3,5-triazin-2-yl-amino) phenol, 4.6-b / s (octiltiometil) -2 -Cresol, 4,6-b / s (dodecylthiomethyl) -2-cresol or other similar compounds. 41