Patent GB-899717-A (GB)
Title: Improvements in the production of expanded fine-pored and light-weight bands, films and sheets from thermoplastic synthetic resins
Inventor: MEYER FERDINAND
IPC: C08J9/14
Filed: 1960-08-10
Abstract: Expanded fine-pored, light weight sheets, films and bands are produced from thermoplastic synthetic resins by (1) applying to a support a solution of the resin in a mixture of a low-boiling solvent and an organic liquid which does not dissolve or only swells the plastic and of which the boiling point is at the most 30 DEG C. higher but preferably lower than that of the solvent, (2) evaporating the solvent at temperatures which lie below the softening temperature of the plastic and (3) expanding the expandable films, sheets and bands containing the non-solvent or swelling organic liquid by heating to temperatures above the softening temperature of the plastic.  Specified resins include polycarbonates; polymers and copolymers prepared from vinyl monomers such as styrene, chlorstyrene, alpha-methyl styrene, N-vinyl carbazole, vinyl chloride, vinyl fluoride, vinylidene chloride, vinylidene fluoride, acrylonitrile, vinyl acetate, vinyl propionate, vinyl butyrate, esters of acrylic acid, methacrylic acid, maleic acid or fumaric acid with methyl, ethyl, propyl, isopropyl, 2-ethylhexyl, decyl or cyclohexyl alcohols; copolymers of the above monomers and aliphatic diolefins such as butadiene-1,3, 2-chlorobutadiene-1,3 or isoprene; and mixtures of such polymers and copolymers.  Low boiling, non-solvent or only swelling organic liquids referred to are pentane, hexane, petroleum ether, cyclohexane, cyclohexene, cyclopentane and cyclopentene.  Suitable solvents are methylene chloride, carbon disulphide, methyl formate and acetonitrile.  Thicker sheets with thicknesses up to 1 cm. may be prepared from highly viscous solutions and these solutions may be prepared in kneaders.  In the examples, the expanded materials are prepared from (1) a copolymer of styrene (90 parts) and butadiene (10 parts), (2) a copolymer of styrene and methyl styrene, (3) after chlorinated polyvinyl chloride, (4) a copolymer of styrene and acrylonitrile mixed with a copolymer of vinyl chloride and vinyl acetate and (5) a copolymer of vinyl chloride, diethyl maleate and dimethyl maleate.  Uses: Wallpaper, heat and electrical insulation, and the production of cups.ALSO:Expanded fine-pored, light weight sheets, films and bands are produced from thermoplastic synthetic resins by (1) applying to a support a solution of the resin in a mixture of a low boiling solvent and an organic liquid which does not dissolve or only swells the plastic and of which the boiling point is at the most 30 DEG C. higher but preferably lower than that of the solvent, (2) evaporating the solvent at temperatures which lie below the softening temperature of the plastic and (3) expanding the expandable films, sheets and bands containing the non-solvent or swelling organic liquid by heating to temperatures above the softening temperature of the plastic.  Specified resins include polycarbonates; polymers and copolymers prepared from vinyl monomers such as styrene, chlorstyrene, alpha-methyl styrene, N-vinylcarbazole, vinyl chloride, vinyl fluoride, vinylidene chloride, vinylidene fluoride, acryloni trile, vinyl acetate, vinyl propionate, vinyl butyrate, esters of acrylic acid, methacrylic acid, maleic acid or fumaric acid with methyl, ethyl, propyl, isopropyl, 2-ethylhexyl, decyl or cyclohexyl alcohols; copolymers of the above monomers and aliphatic diolefins such as butadiene-1, 3, 2-chloro-butadiene-1, 3 or isoprene; and mixtures of such polymers and copolymers.  Low boiling, non-solvent or only swelling organic liquids referred to are pentane, hexane, petroleum ether, cyclohexane, cyclohexene, cyclopentane and cyclopentene.  Suitable solvents are methylene chloride, carbon disulphide, methyl formate and acetonitrile.  A substance which gives off gas when heated may also be included in the film forming solution.  The expansion stage may be effected using hot water, steam, infra-red or using high frequency heating.  In the examples, the expanded materials are prepared from (1) a copolymer of styrene (90 parts) and butadiene (10 parts), (2) a copolymer of styrene and methylstyrene, (3) after chlorinated polyvinyl chloride (4) a copolymer of styrene and acrylonitrile mixed with a copolymer of vinyl chloride and vinyl acetate and (5) a copolymer of vinyl chloride, diethyl maleate and dimethyl maleate.  Uses.  Wallpaper, heat and electrical insulation, and the production of cups.