GB585205A - Curing of polymeric materials - Google Patents

Abstract

Organic diisocyanate modified polyesteramides are cured by heating in uniform admixture with a cellulose derivative, e.g. cellulose acetate or nitrate and benzyl cellulose, a curing agent, namely, formaldehyde or formaldehyde-liberating substance or a dichromate, and preferably a curing catalyst, namely, an acid or a substance which is substantially neutral, but which develops acidity under curing conditions. The ingredients are mixed by milling dry or in the presence of water or an organic solvent, and 25 to 175 parts of cellulose derivative are used per 100 parts of modified polyester amide. Additional compounding ingredients are fillers, for example, carbon black, iron oxide, clay, asbestos, blanc fixe, whiting, lithopone and mica; resins, for example, urea-formaldehyde and phenol-formaldehyde resins; other plastic materials, for example, natural or synthetic rubbers, vulcanized vegetable oils, dark substitute, white substitute, a Cumar resin, wood rosin and pitch; de-tackifying agents, that is to say, materials which reduce the tendency of the mix to stick to the rolls, for example, stearic acid, paraffin wax, oleic acid, lauric acid and dibutyl ammonium oleate; plasticisers, for example, tricresyl phosphate, dibutyl phthalate, butylphthalyl butyl glycollate, and N - alkyl - toluene - sulphonamides; stabilisers or anti-oxidants, for example, hydroquinone, N : N1 - hexamethylene - bis - ortho - benzamide, N - phenyl - a - naphthylamine, N - phenyl - b - naphthylamine and a : a - bis - (2 - hydroxy-3 : 5-dimethylphenyl) butane, as well as others commonly used in rubber technology. Small quantities of pigments, for example from 1-3 per cent by weight, such as are customarily used in rubber technology or in the coating composition art may also be used to impart colour. The ingredients are mixed and shaped or calendered on to a substrate followed by heating at 100-150 DEG C. Solvents or swelling agents may be incorporated, e.g. acetone, mixtures of benzene and acetone, mixtures of benzene and ethanol, mixtures of benzene and chloroform, mixtures of benzene and methylethyl ketone, mixtures of methyl ethyl ketone and tri-chlorethylene, and mixtures of acetone and the monoethyl ether of ethylene glycol. Polyester and polyamide-forming reactants specified are glycols, for example, ethylene glycol, diethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, dodecamethylene glycol, 1 : 12-octadecanediol and pentaglycol; aliphatic or aromatic amino-alcohols having at least one hydrogen atom attached to the amino nitrogen atom and preferably containing an aliphatic chain of at least two carbon atoms separating the amino and hydroxyl groups, for example b -ethanolamine and 3-aminopropanol; dibasic carboxylic acids or ester-forming derivatives thereof, preferably aliphatic dicarboxylic acids, for example, malonic, succinic, glutaric, adipic, b -methyladipic, pimelic, suberic, azelaic, sebacic, undecanedioic, brassylic, iso-phthalic, hexahydroterephthalic, p-phenylene-diacetic, and acetone-dicarboxylic acids; primary and secondary diamines, for example, ethylene diamine, hexamethylenediamine, 3 - methylhexamethylene diamine, decamethylenediamine, m-phenylene-diamine, N : N1 - dimethylhexamethylene - diamine, N : N1 - diethylhexamethylenediamine and N : N1 - dimethyldecamethylenediamine; monohydroxymonocarboxylic acids or their ester-forming derivatives, for example, glycollic, 6-hydroxycaproic, 10-hydroxydecanoic and 12-hydroxystearic acids; polymerizable monoaminomonocarboxylic acids, or their ester-forming derivatives, for example, 6-aminocaproic acid or its lactam, caprolactam, and 9-aminononanoic, 11-aminoundecanoic and 12-aminostearic acids. Diisocyanates specified are ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, p : p1-diphenyl diisocyanate, diphenylmethane-4 : 41-diisocyanate, naphthalene diisocyanates and adipyl diisocyanate. Articles and applications specified are gaskets, packings, hose, diaphragms for pumps, flexible containers, the coating of rollers, blankets and stereos for use in the printing industry, protective sheathings for insulated electric cables and other electrical conductors, the coating of balls for games, tyres and flexible materials generally, including fabrics, protective clothing, leather cloth and floor coverings, and generally in the construction of articles requiring the use of a material having physical properties resembling those of rubber, but also having a good resistance to the action of organic fluids and a low permeability to gases and vapours. The compositions may be used as lacquers or finishing compositions or as substitutes for leather or adhesives for wood, metal, fabrics, paper, leather and regenerated cellulose. In the examples, the organic diisocyanate modified polyesteramide, as described in example 7 in Specification 580,524, is milled with hexamethylol-melamine hexamethyl ether, titanium dioxide, and 2 : 4-dichloro-1-naphthol, the mix is dissolved in benzene and acetone, and mixed with (1) cellulose acetate (acetone-soluble), and (2) nitrocellulose (obtainable under the name Collodion Cotton HX 30/50). In example 3, the same modified polyesteramide is mixed with cellulose acetate, carbon black, hexamethylol melamine hexamethyl ether, 2.4-dichloro-1-naphthol, ethylene glycol monoethyl ether and acetone, and used to provide a top-coating for the hydrolysed-leather-organic diisocyanate-modified polyesteramide-coated fabric obtained according to Specification 583,862. Specifications 580,526 and 581,146 also are referred to.