Patent GB-855213-A (GB)
Title: A process for the production of vinyl chloride polymers
Inventor: BASKETT ARTHUR COLIN
IPC: C08F14/06
Filed: 1958-07-18
Abstract: Polyvinyl chloride is produced by exposing vinyl chloride, in the liquid phase or in solution, suspension or emulsion, as the sole polymerizable monomer, at a temperature below -20 DEG C. to electromagnetic ionising radiation, uncharged or positively charged particulate ionising radiation, or ultra-violet light. Specified dispersion media for the vinyl chloride are mixtures of water and alcohols e.g. methanol, ethylene glycol and glycerol, and aqueous solutions of inorganic salts.  Specified radiations are X-rays; gamma-rays e.g. from atomic piles or their waste fission products and from radio-active materials such as radium, cobalt 60, tantalum 182 and iridium 192; high speed neutrons; positive ions; a -particles; positrons; low intensity neutrons such as may be obtained by mixing a radio-active element e.g. radium, polonium or antimony 124 with beryllium; and U-V light of 2,000-4,000   wavelength.  When ionising radiation is used a sensitizer may be present e.g. chlorohydrocarbons such as tetrachloro-ethane or chloroform; aliphatic alcohols such as n-propanol; ethers; and ketones.  When U-V light is used a photosensitizer may be present e.g. acetone; biacetyl; benzoin and its ethers; acyleg.. diacetyl-peroxides: aliphatic azo compounds such as alkyl esters of azo-bis-isobutyric acid; metal alkyls such as tetraethyl lead; or uranyl or ferric salts.  The process may be effected batchwise or continuously.  The products may be used to produce tubing for plumbing, panels for lining chemical tanks and other plant, films and fibres, and has good electrical properties for use in conduits and other electrical equipment. The products have high softening points which may be further increased by annealing. Examples contrast the softening points of products obtained by irradiation with g -rays at -80 DEG C. or with U-V light at -26 DEG C. with that of polyvinyl chlorides obtained by suspension polymerization at 50 DEG C.  Specification 717,771 is referred to.ALSO:Polyvinyl chloride is produced by exposing vinyl chloride, in the liquid phase or in solution, suspension or emulsion, as the sole polymerizable monomer, at a temperature below -20 DEG C. to electromagnetic ionising radiation, uncharged or positively charged particulate ionising radiation, or ultra-violet light. Specified dispersion media for the vinyl chloride are mixtures of water and alcohols, e.g. methanol, ethylene glycol and glycerol, and aqueous solutions of inorganic salts.  Specified radiations are X-rays; gamma-rays, e.g. from atomic piles or their waste fission products and from radio-active materials such as radium, cobalt 60, tantalum 182 and iridium 192; high speed neutrons; positive ions; alphaparticles; positrons; low intensity neutrons such as may be obtained by mixing a radio-active element, e.g. radium, polonium or antimony 124 with beryllium; and U-V light of 2,000-4,000 wavelength.  When ionising radiation is used a sensitizer may be present, e.g. chlorohydrocarbons such as tetrachloro-ethane or chloroform; aliphatic alcohols such as n-propanol; ethers; and ketones.  When U-V light is used a p  photo-sensitizer may be present, e.g. acetone; biacetyl; benzoin and its ethers; acyl-, e.g. diacetyl-peroxides; aliphatic azo compounds such as alkyl esters of azo-bis-isobutyric acid; metal alkyls such as tetraethyl lead; or uranyl or ferric salts.  The process may be effected batchwise or continuously.  The products may be used to produce tubing for plumbing, panels for lining chemical tanks and other plant, films and fibres, and has good electrical properties for use in conduits and other electrical equipment.  The products have high softening points which may be further inceased by annealing.  Examples contrast the softening points of products obtained by irradiation with gamma-rays at -80 DEG C. or with U-V light at -26 DEG C. with that of polyvinyl chlorides obtained by suspension polymerization at 50 DEG C. Specification 717,771 is referred to.