GB740994A - Improvements relating to plastic products - Google Patents

Abstract

Two plasticized thermoplastic organic substitution derivatives of cellulose which contain the same substituent or substituents but in different proportions and which are free from liquids other than plasticizers are fed to a chamber through which they are forced under pressure whilst they are being mixed together and heated to a temperature at which one of the derivatives is more plastic than the other. The mixture is thus extruded from the chamber in the form of a coherent product in which regions occupied by one material are visually distinguishable from regions occupied by the other. The mixture may be forced from the chamber by a screw. Within the chamber one of the materials may become liquid whilst the other remains solid. The two materials may be differently coloured. The cellulose derivatives may have different degrees of substitution, e.g. they may be plasticized cellulose acetate of acetyl value 51-54 per cent (having a greater plastic flow rate) and plasticized cellulose acetate of acetyl value 56-62.5 per cent (having a lesser plastic flow rate). The mixture may be extruded in rod, sheet or tube form. Blocks of the patterned material may be made by bonding sheets together or extruding into a mould. The Provisional Specification refers also to the application of the invention to the following materials: polymerized monovinyl and monovinylidene compounds, including copolymers; acrylic polymers, especially copolymers of acrylonitrile with methacrylonitrile, with vinyl chloride or with vinylidene chloride; polymers of ethylene; polymers of styrene and chloro-substituted styrenes; condensation polymers such as the polyamides; polyesters; polyester - amides; polyamino carboxylic acids. The Provisional Specification refers also to polymers containing the recurring units -CH(CN).CH2-, -C (CN)2.CH2-, and to cellulose triacetate, 6,6-nylon, polyethylene terephthalate; mixed condensation polymers, e.g. condensation polymers of hexamethylene diamine with adipic acid or sebacic acid; cellulose acetate-butyrate and acetate-propionate; and ethyl cellulose.ALSO:Two plasticized thermoplastic organic substitution derivatives of cellulose which contain the same substituent or substituents but in different proportions and which are free from liquids other than plasticizers are fed to a chamber through which they are forced under pressure whilst they are being mixed together and heated to a temperature at which one of the derivatives is more plastic than the other. The mixture is thus extruded from the chamber in the form of a coherent product in which regions occupied by one material are visually distinguishable from regions occupied by the other. The mixture may be forced from the chamber by a screw. Within the chamber one of the materials may become liquid whilst the other remains solid. The two materials may be differently coloured. The cellulose derivatives may have different degrees of substitution, e.g. they may be plasticized cellulose acetate of acetyl value 51-54 per cent (having a greater plastic flow rate) and plasticized cellulose acetate of acetyl value 56-62.5 per cent (having a lesser plastic flow rate). The mixture may be extruded in rod, sheet or tube form. Blocks of the patterned material may be made by bonding sheets together or extruding into a mould. The Provisional Specification refers also to the application of the invention to the following materials:-Polymerized monovinyl and monovinylidene compounds, including copolymers; acrylic polymers, especially copolymers of acrylonitrile with methacrylonitrile, with vinyl chloride or with vinylidene chloride; polymers of ethylene; polymers of styrene and chloro-substituted styrenes; condensation polymers such as the polyamides; polyesters; polyester-amides; polyamino carboxylic acids. The Provisional Specification refers also to polymers containing the recurring units -CH(CN). CH2-, -C(CN)2. CH2-, and to cellulose triacetate, 6.6, nylon, polyethylene terephthalate; mixed condensation polymers, e.g. condensation polymers of hexamethylene diamine with adipic acid or sebacic acid; cellulose acetate-butyrate and acetate-propionate; and ethyl cellulose.