GB458642A - A process for the production of films, strips, filaments or other objects - Google Patents

Abstract

Films, strips, filaments, or other objects are formed from a composition comprising a cellulose ester and/or ether and a relatively small amount of a solid insoluble metallic phthalate dispersed therein. In a modification, a phthalated pigment may be used instead of the metallic phthalate, i.e. a pigment on the surface of which a phthalate has been formed or phthalic acid has been adsorbed by immersion of the pigment in a solution of phthalic acid. Suitable phthalates are those of titanium, lead, copper, cobalt, cadmium, manganese, iron, barium and mercury. These pigments transmit very little ultra-violet light. When making artificial silk sufficient pigment may be added to produce a delustred appearance, i.e. 5--15 per cent of the weight of cellulose. For films a smaller amount is used, e.g. 1--5 per cent, transparency being thereby retained and ultra-violet light transmission reduced. Such films are very suitable for packing foodstuffs or for safety glass. The pigment is preferably dispersed by pebble mill grinding. A phthalated pigment may be prepared by standing 1000 grams of antimony oxide, barium-titanium oxide pigment or of calcium-titanium pigment (a mixture of titanium oxide with a small amount of a calcium compound) in a 0,7 per cent solution of phthalic acid overnight. These pigments adsorb phthalic acid. Leaded zinc (5--50 per cent lead sulphate and 95--50 per cent zinc oxide) on the other hand immersed in a 1--5 per cent solution of phthalic acid reacts therewith to produce a zinc phthalate-containing complex.