Patent GB-640597-A (GB)
Title: Compositions comprising polymeric materials
IPC: C08L1/18
Filed: 1948-03-01
Abstract: Compositions which may be formed into films or spread or calendered on to a substrate such as the surface of a coated fabric, comprise an organic polyisocyanate modified polyester in uniform admixture with nitrocellulose.  The polyester is said to function as a plasticizer and is formed from a glycol and a dibasic carboxylic acid or from an ester-forming derivative of either or both of these or from a mixture of two or more of each of such components.  20-100 parts by weight of the modified polyester may be used per 100 parts of nitrocellulose. Glycols which may be used are ethylene glycol, 1 : 2-propylene glycol, diethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, decamethylene glycol, dodecamethylene glycol, 1 : 12-octadecanediol and pentaglycol [(CH3)2 : C : (CH2OH)2].  Examples of dibasic carboxylic acids are malonic, succinic, glutaric, adipic, b  - methyladipic, pimelic, suberic, azelaic, sebacic, undecanedioic, brassylic, isophthalic, terephthalic, hexahydroterephthalic, p-phenylene-diacetic and acetone-dicarboxylic acids.  Preferably the polyesters used have a molecular weight of 1000 or more and the organic polyisocyanate modified polyesters over 10,000.  The polyesters are modified with the organic polyisocyanate in known manner, up to 15 per cent, and usually at least 3 per cent by weight of the polyisocyanate being used.  Examples of organic polyisocyanates are hydrocarbon polyisocyanates including ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, naphthalene diisocyanates, benzene-1 : 3 : 5 - triisocyanate, toluene - 2 : 4 : 6 - triisocyanate, ethylbenzene - 2 : 4 : 6 - triisocyanate, monochlorbenzene - 2 : 4 : 6 - triisocyanate, triphenylmethane - 4 : 41 : 411 - triisocyanate and diphenyl-2 : 4 : 41-triisocyanate.  The modified polyester or mixture of modified polyesters may be mixed with the nitrocellulose by mixing or milling together at moderately elevated temperature as such or may be mixed in the presence of organic liquids which are solvents for one or both components, or solutions of the components may be mixed, the solvents, if volatile, being subsequently removed.  Suitable organic liquids include acetone, ethyl acetate, chloroform, mixtures of benzene and acetone, mixtures of benzene and ethanol, mixtures of benzene and chloroform, mixtures of benzene and methyl ethyl ketone, mixtures of methyl ethyl ketone and trichlorethylene, mixtures of acetone and the monoethyl ether of ethylene glycol, mixtures of ethyl acetate and chloroform, and mixtures of acetone and chloroform.  The modified polyester may be formed in situ, for example by incorporating the polyester and the polyisocyanate with the nitrocellulose, and thereafter heating the mixture. Additional organic polyisocyanates, fillers and pigments such as carbon black, iron oxides, clay, asbestos, blanc fixe, whiting, and lithopone, and plasticizers such as tricresyl phosphate, dibutyl phthalate, butyl-phthalyl butyl glycollate, and N-alkyl-toluenesulphonamides may be incorporated in the compositions.  Also antioxidants such as hydroquinone, N : N1-hexamethylene-bis - ortho - hydroxy - benzamide, N - phenyl - alpha - naphthylamine, N - phenyl - beta - naphthylamine and alpha: alpha - bis - (2 - hydroxy - 3 : 5 - dimethylphenyl) - butane.  In an example 2 parts of polyethylene sebacate modified with 3.85 per cent by weight of hexamethylene diisocyanate are dissolved in 10 parts of chloroform and mixed with a solution of 4 parts of nitrocellulose dissolved in 20 parts of ethyl acetate and the solvents evaporated.  In this and other examples methods of preparing and modifying the polyester are described.  Specifications 580,524 and 580,526 are referred to.ALSO:Polyisocyanates which may be used for modifying polyesters employed in cellulose nitrate compositions (see Group IV (a)) may be obtained by passing phosgene into a suspension of the corresponding amine hydrochloride in an inert medium, for example, orthodichlorobenzene, at a temperature of 140-180 DEG  C.  Examples of organic polyisocyanates which may be prepared in this manner are hydrocarbon polyisocyanates including ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, p - phenylene diisocyanate, m-phenylene diisocyanate, naphthalene diisocyanates, benzene-1 : 3 : 5 - triisocyanate, toluene - 2 : 4 : 6 - triisocyanate, ethylbenzene - 2 : 4 : 6 - triisocyanate, monochlorobenzene - 2 : 4 : 6 - triisocyanate, triphenylmethane - 4 : 41 : 411 - triisocyanate, and diphenyl-2 : 4 : 41-triisocyanate.