GB420116A - Improvements in fireproofing rubber and its manufacture - Google Patents

Abstract

In examples for chlorinating drying or semidrying oils, (1) chlorine is passed into a solution of raw linseed oil in carbon tetrachloride for five hours. The chlorinated oil is precipitated by ethyl alcohol, washed with alcohol and boiled in water. After complete removal of water, the product is a transparent, viscous, fluid mass; (2) raw linseed oil is chlorinated as in (1) for upwards of 24 hours. The chlorination can be accelerated by exposure to sunlight. On purification as above, a brittle resinous mass is obtained; (3) mixtures of raw linseed oil and rubber in solution in carbon tetrachloride are chlorinated together, the product being a solid.ALSO:Compositions containing rubber are made fire-resistant by incorporating chlorinated derivatives of drying or semidrying oils. Chlorinated rubber, polymerized chlorobutadiene, and chlorinated cyclic hydrocarbons may also be incorporated. The fire resistant properties may also be increased by suitable choice of compounding and vulcanizing ingredients e.g. clay, magnesium carbonate or selenium. The chlorinated additions may be blended before addition to the rubber, by mixing solutions of them or by chlorinating a mixed solution of the parent materials and separating the mixture therefrom. In examples (1) chlorine is passed into a solution of raw linseed oil in carbon tetrachloride for five hours. The chlorinated oil is precipitated by ethyl alcohol, washed with alcohol and boiled in water. After complete removal of water, the product is a transparent, viscous, fluid mass; 2 parts of this product, 1 of chlorinated rubber and 3 of rubber in solution in carbon tetrachloride is precipitated by ethyl alcohol, boiled with water and dried and milled with 1 1/2 per cent sulphur, 2 1/2 per cent zinc oxide, 1 per cent stearic acid and 1/2 per cent mercaptobenzthiazole and vulcanized at 147 DEG C. for 10 minutes; (2) raw linseed oil is chlorinated as in (1) for upwards of 24 hours. The chlorination can be accelerated by exposure to sunlight. On purification as above a brittle, resinous mass is obtained. A mixture of rubber 100, sulphur 3, zinc oxide 5, stearic acid 2, and mercaptobenzthiazole 1 with an equal weight of the powdered chlorinated oil is vulcanized at 147 DEG C. for 10 minutes; (3) mixtures of raw linseed oil and rubber in solution in carbon tetrachloride are chlorinated together, the resultant solid mass being mixed with a rubber mix as in (2) and vulcanized; (4) solutions of chlorinated rubber and chlorinated linseed oil are mixed and the mixed derivatives precipitated by ethyl alcohol.