GB505770A - Improvements in rubber hydrohalides - Google Patents

Abstract

505,770. Rubber hydrohalides. WINGFOOT CORPORATION. Nov. 16, 1937, No. 31448. Convention date, March 23. [Class 70] A solution of rubber hydrohalide prepared by treating a solution of rubber in benzene or like organic solvent with hydrogen halide, is neutralized at a temperature above that at which gelation occurs. Benzene and like solvents, e.g. toluene and xylene, give rubber hydrohatide solutions which gel on cooling. The neutralization is preferably carried out with solid alkaline compound such as soda ash or sodium sulphate of fine particle size. The hot solution may be allowed to percolate. through a thick bed of the alkali, or the alkali may be stirred into the solution. After neutralization, the solutions are advantageously filtered hot and applied hot to form coatings or films. Stabilizers such as hexamethylenetetramine or other stabilizer described in Specification 437,304, may be added, and also plasticizers, e.g. paraffin wax or butyl stearate, colouring matter and other compounding ingredients. In an example, a solution of 250 lb. of rubber in 3,321 1b. of benzol is mixed with 68 lb. of soda ash and 250 gallons of benzol. The mixture is gradually heated to 140‹ F. during a period of 10À5 hours and then an additional 10 1b. of soda ash is added and heating at 140‹ F. continued for 2 hours. The mixture is then cooled to 130‹ F. and filtered. The Specification as open to inspection under Sect. 91 comprises also the hot neutralization of non-gelling solutions of rubber hydrohalides in solvents such as chloroform. This subjectmatter does not appear in the Specification as accepted.