Patent GB-712812-A (GB)
Title: Improvements in or relating to synthetic sheet material and shaped articles
IPC: C08J5/04
Filed: 1949-10-23
Abstract: A composition used in making sheet materials &c., contains in intimate mixture rubber latex, a filler, one or more organic solvents, e.g. rubber solvents, and 15 per cent. or more, preferably 25 per cent., of concentrated aqueous ammonia by weight of the latex. A colouring agent may be added before or during mixing.  The latex may contain natural and/or synthetic rubber and a synthetic rubbery polymer, e.g. plasticized polyvinyl chloride or polybutadiene.  The latex may contain reclaim rubber and natural rubber in a weight ratio of 15 to 1 and at least one part of a synthetic rubbery polymer for each 15 parts of reclaim rubber present.  A composition suitable for making substitute leather may contain as filler leather powder or fibre, from 50 to 85 per cent. of rubber latex based on the weight of filler and 40 to 50 per cent. of solvent based on the composition. The amount of concentrated aqueous ammonia may exceed 50 per cent. and the weight of solvent or solvents may be decreased by an amount equal to the excess of ammonia but not below 5 per cent. of the total weight of filler, latex and ammonia.  Upwards of 1 per cent. of chromic oxide or sulphate, aluminium oxide or sulphate or potassium alum may be added to the ammonia before it is used.  The following are suitable solvents:-petroleum ether, preferably mixed with trichlorethylene, petrol, white spirit, carbon tetrachloride, toluol, xylol and benzol.  The following may also be used as fillers:-cotton, jute, rayon, wool, asbestos and cork. Mineral oil may be added. Specification 390,526, [Group V], is referred to.ALSO:A composition used in making sheet materials &c. contains in intimate mixture rubber latex, a filler, one or more organic solvents, e.g. rubber solvents, and 15 per cent. or more, preferably 25 per cent., of concentrated aqueous ammonia by weight of the latex.  The ingredients may be mixed on mixing rolls or in a rubber mill.  A colouring agent may be added before or during mixing.  A composition suitable for making substitute leather contains finely divided leather or leather fibre as filler, from 50 to 85 per cent. of rubber latex based on the weight of filler and 40 to 50 per cent. of solvent based on the composition.  The latex may be natural rubber latex, an emulsion containing natural and synthetic rubber or an emulsion containing natural, synthetic or reclaim rubber and optionally a synthetic rubbery polymer, e.g. plasticized polyvinyl chloride or polybutadiene.  The latex may contain reclaim rubber and natural rubber in a weight ratio of 15 to 1, and at least one part of a synthetic rubbery polymer may be added for each 15 parts of reclaim rubber present.  The amount of concentrated aqueous ammonia may exceed 50 per cent. and the weight of solvent or solvents may then be decreased by an amount equal to the excess of ammonia, but not below 5 per cent. of the total weight of filler, latex and ammonia. Upwards of 1 per cent. of chromic oxide or sulphate, aluminium oxide or sulphate or potassium alum may be added to the ammonia before it is used.  The following are suitable solvents:-petroleum ether, preferably mixed with trichlorethylene, petrol, white spirit, carbon tetrachloride, toluol, xylol and benzol.  The following may also be used as fillers:-cotton, jute, rayon, wool, asbestos and cork. Mineral oil may be added.  Specification 390,526 is referred to.