GB572738A - Improvements in polymeric materials - Google Patents

Abstract

Organic di-isocyanate modified polyesters or polyester-amides are given improved physical properties by mechanically working them whilst in a plastic condition. The products have increased solubility in organic liquids and a decreased plasticity, while their solutions are progressively less viscous as they are made from polymers which have been subjected to progressively longer periods of working. The mechanical working may be performed on a two-roll, differentially-geared rubber mill, at a temperature such that the polymer forms a running band on the slow-moving roll, or an internal-mixer may be used. Working for 1/2 to 1 hour is usually sufficient, and temperatures of 60 DEG C. and 85 DEG C. are mentioned. Other ingredients may be incorporated with the polymers during or after the working, and specified optional additions are carbon black, clay, asbestos, blanc fixe, whiting, lithopone, mica, ethanol, benzene, acetone, trichlorethylene, tetrachlorethylene, methyl ethyl ketone, natural or synthetic rubbers, vulcanized vegetable oils, white substitute, dark substitute, "Cumar" (Registered Trade Mark) resin, wood rosin, pitch, stearic acid, paraffin wax, oleic acid, lauric acid, tricresyl phosphate, dibutyl ammonium oleate, dibutyl phthalate, butylphthalyl butyl glycollate, N-alkyl-toluenesulphonamides, pigments, hydroquinone, N : N1-hexamethylene bis - ortho - hydroxybenzamide, and other anti-oxidants customarily used in rubber technology. According to examples: (1) a polyester-amide, prepared from ethylene glycol, adipic acid and ethanolamine, and modified by treatment with hexamethylene di-isocyanate, is compounded with hydroquinone and milled for 40 mins. at or below 60 DEG C.; (2) a polyester-amide, prepared from ethylene glycol and hexamethylene diammonium adipate, and modified by treatment with hexamethylene di-isocyanate, is compounded with hydroquinone and worked in an internal mixer for 40 mins. at or below 85 DEG C.; (3) a polyester from ethylene glycol and adipic acid, modified with hexamethylene di-isocyanate, is compounded with hydroquinone and worked as in example (1). Specification 553,733 is referred to.