SU1137100A1 - Composition based on isoprene rubber - Google Patents

Abstract

COMPOSITION BASED ON ISOPRENE RUBBER LATEX, comprising sulfur, zinc oxide, zinc mercaptobenzothiazole, zinc diethyldithiocarbamate, IS -

Description

The invention relates to the production of latex articles, in particular protective gloves, having reduced flammability. The following compounds are used as fire extinguishing additives for the protection of natural and butyl rubbers: chloroparaffins in combination with alkali and alkaline earth metal borates l, -1decabromodiphenyl t2, bromine-containing phosphates 3, The said compounds, when applied to latex articles, either do not provide the required fire protection effect or cannot be introduced into the latex at all, since they destabilize the latex system. A composition based on butyl rubber latex is known, containing a combination of fire retardants consisting of hexabromobenzene, chloroparaffin, and antimony trioxide 4J. The disadvantage of this composition for finishing carpets is that in order to achieve a noticeable fire-protective effect it is necessary to introduce more than 80% of the specified combination of fire retardants, which causes a sharp deterioration in the physical, mechanical and elastic properties of the products. At the same time, even such filling with the specified fire retardants does not provide the required fire retardant properties, while smaller amounts do not provide the required fire retardant properties. The closest to the proposed one in technical essence is a composition based on unsaturated rubber latex, including sulfur, zinc oxide, vulcanization accelerators mercaptobenzothiazole zinc and zinc dithyl dithiocarbamate, as well as an antioxidant - N- (1,3-dimethylbutyrosulfonate) -N-phenyl -p-phenylenediamine, chloroparaffin and a bromine-containing fire retardant - pentabromotoluene Z. However, the fire-resistant properties of this composition are insufficient. The purpose of the invention is to increase the fire resistance of latex products. The said objective is achieved in that the composition based on isoprene rubber latex includes sulfur, zinc oxide, zinc mercaptobenzothiazole, zinc diethyldithiocarbamate, N-(153-dimethylbutyl)-K-phenyl p-phenylenediamine, chloroparaffin and a bromine-containing fire retardant, containing N-4-aminophen-1-bromphthalamide as the bromine-containing fire retardant and additionally antimony trioxide in the following ratio of components, in parts by weight: Isoprene rubber latex (dry matter) 100 Sulfur 1.2-1.6 Zinc oxide 5.0-5.4 Zinc mercaptobenzothiazole. 1,8-2,2 Pink diethyldithiocarbamate1,4-1,8 N -(1,3-dimethylbutyl)- N -phenyl-p-phenylenediamine,7 Chloroparaffin15-20 N-4-aminophenyltetra-. bromophthalimide20-30 Antimony trioxide8-10 The N-4-aminophenyltetrabromophthalimide or otherwise called tetrabromophthalaminoazobenzene b used in the proposed composition has the formula It is an orange amorphous powder, poorly soluble in benzene and acetone, soluble in xylene and acetic anhydride, has a melting point of 314-317 C. Examples. Latex compositions are prepared by conventional technology by preparing dispersions of the ingredients and mixing them with latex. The compositions of the composition based on natural latex and the properties of films made from them are given in Table 1, and the composition of the compositions based on SKI latex and the properties of the films are in Table 2. The fire resistance of the films is assessed according to GOST 15898-70 on the OT-68 device with a vertical sample position and flame supplied from below. The duration of exposure to flame is measured, after which the samples immediately stop burning, i.e. self-extinguishing occurs. Fire resistance, as well as the duration of residual smoldering of the samples after their combustion has ceased, physical and mechanical

3.1

The properties of latex films are determined according to GOST 12580-79.

As can be seen from the presented data, the use of N-4-aminophenyltetrabromophthalimide in combination with chloroparaffin or hexabromobenzene and antimony trioxide makes it possible to obtain a product based on natural rubber, which has high fire resistance and satisfactory physical and mechanical properties. To obtain such a fire-retardant effect using hexabromobenzene with chloroparaffin and antimony trioxide, it is necessary to introduce it into the latex mixture in an amount of 50, 20 and 10 wt. parts, respectively. In this case, a sharp decrease in the physical and mechanical properties of latex films occurs.

371004

It should be noted that when using the proposed combination of fire retardants, the combustion nature of the samples changes noticeably. Thus, the formation of a rigid framework formed by coke and preventing the spread of flame over the surface of the sample is observed. At the same time, after the samples are transferred from the flame, they instantly die out. .;

The test results show that N-4-aminophenyltetrabromophthalimide is effective for latex films based on SKI latex.

15 Thus, the proposed composition allows obtaining latex products with reduced flammability without changing traditional technology and improving mechanical properties and can be easily introduced into industry.

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Claims (1)

A COMPOSITION BASED ON ISOPRENE RUBBER LATEX, comprising sulfur, zinc oxide, zinc mercaptobenzothiazolate, zinc diethyldithiocarbamate, U-(1,3-dimethylbutyl)-N-phenyl-P-phenylenediamine, chloroparaffin and a brominated fire retardant, characterized in that, in order to increase fire resistance, it contains N-4-aminophenyltetrabromophthalimide as a brominated fire retardant and additionally antimony trioxide in the following ratio of components, parts by weight: Isoprene rubber latex (dry) substance) 100 Sulfur 1.2-1.6 Zinc oxide Mercaptobenzothiazolate 5.0-5.4 zinc Diethyldithiocarbamate 1.8-2.2 zinc N-(1,3-dimethylbutyl)- 1.4-1.8 - N-phenyl-p-phenylene- diamine 1.3-1.7 Chlorinated paraffin N-4-aminophenyltetra- 15-20 .(bromophthalimide 20-30 Antimony trioxide 8-10 SU _t , 1137100