Patent GB-1479942-A (GB)
Title: Thermoplastic moulding compositions
IPC: C08L51/02
Filed: 1974-09-25
Abstract: 1479942 Thermoplastic moulding compositions comprising vinyl chloride polymer WACKER-CHEMIE GmbH 25 Sept 1974 [25 Sept 1973] 41726/74 Heading C3P A thermoplastic moulding composition (for use in the manufacture, for example, of rigid sheets, flexible sheets and shaped articles, for instance hollow articles such as bottles) is prepared from (a) a homopolymer of vinyl chloride or a copolymer containing a major proportion of units derived from vinyl chloride and a minor proportion (for example not more than 10 weight per cent) of units derived from another alpha-ethylenically unsaturated monomer, (b) a "modifying resin", in an amount of from 2 to 20 weight per cent based on the total weight of component (a) plus component (b), and (c) stearic acid-coated calcium carbonate having a particle size of from 0À04 to 0À1 microns and, preferably, a surface area of from 10 to 50m.<SP>2</SP>/g., in an amount of from 2 to 30 weight per cent based on the weight of component (a), the "modifying resin" being defined as a resin which is such that an article produced from a moulding composition prepared from material consisting of component (a) and modifying resin has an improved notched impact strength relative to an article produced from a moulding composition prepared from material consisting of component (a) alone. The modifying resin preferably is a rubbery polymer. Specified modifying resins are long chain fumaric acid ester copolymers, acrylate copolymers, methacrylate-butadiene-styrene copolymers, acrylonitrile - butadiene - styrene copolymers, ethylene - vinyl ester copolymers, chlorinated polyethylenes and sulphochlorinated polyethylenes. The modifying resin may be in the form of a graft copolymer with vinyl chloride. The composition additionally may contain auxiliaries customarily present in moulding compositions which comprise vinyl chloride polymers. Specified auxiliaries are stabilizers, for example barium-cadmium stabilizers, lead compounds and organotin compounds; lubricants and processing aids, for example montan waxes, esters of long chain fatty acids, calcium salts and magnesium salts of long chain fatty acids, higher fatty alcohols, polyethylenes, acrylates and organopolyiloxanes; colorants, for example organic dyestuffs such as phthalocyanine dyestuffs, for instance Chromophthal Blue, and inorganic pigments such as carbon black, titanium oxide, iron oxide and cadmium pigments; and plasticizers. As exemplified, compositions are prepared from vinyl chloride homopolymer, modifying resin, proprietary stearic acid-coated calcium carbonate and either (Examples 1, 2, 3 and 6) dioctyltin thioglycollic acid ester (Examples 1 and 6) or dioctyltin dithioglycollate/glycerol monofatty acid ester (Examples 2 and 3) as stabilizer, partially saponified montan ester wax, polyethylene wax, glycerol monoricinoleate and a processing auxiliary based on modified acrylate resin or (Examples 4 and 5) barium-cadmium stabilizer, octyl epoxystearate, hydroxystearic acid and proprietary chelating agent, the modifying resin being (Examples 1, 2 and 6) methacrylate-butadiene-styrene copolymer or (Example 3) acrylonitrile-butadiene-styrene copolymer or (Example 4) ethylene-vinyl acetate copolymer or (Example 5) chlorinated polyethylene.