GB1383268A - Method for the preparation of moulding compositions - Google Patents

Abstract

1383268 Foaming inorganic substances LION YUSHI KK (LION OIL & FAT CO Ltd) 23 Feb 1973 [24 Feb 1972] 9123/73 Heading C1A [Also in Division C3] Moulding compositions comprising a particulate inorganic substance coated with an organic polymer are prepared by subjecting a foaming inorganic substance to a treatment to remove water of crystallization or other combined water or carbon dioxide therefrom and thereafter bringing the degassed inorganic substance into contact with a vinyl monomer capable of radical polymerization or radical copolymerization thereby effecting the polymerization reaction of the vinyl monomer. A "foaming inorganic substance" refers to a compound having water of crystallization, a hydroxy group, or a carbonate group, and which is capable of releasing water of crystallization, water or gaseous carbon dioxide when heated and/or kept under reduced pressure, and having sufficient strength to retain the skeleton like structure by the removal of water or gas. Illustrative of the foaming inorganic substance are CaSO 4 2H 2 O, CaSO 3 ¢H 2 O, Al 2 O 3 6H 2 O, CaCO 3 Ca(OH) 2 , Al(OH) 3 , MgCO 3 , Mg(OH) 2 , BaCO 3 , Ba(OH) 2 , Na 2 SO 4 10H 2 O, CaCl 2 2H 2 O, 3CaOSiO 2 6H 2 O. A list of suitable vinyl monomers includes salts and esters of acrylic and meth-acrylic acids, vinyl esters, dienes, vinyl chloride, vinylidene chloride, styrene, vinylpyridine, vinyl isocyanate, acrylonitrile and meth-acrylonitrile. The foaming inorganic substance may be heated at 100‹ to 500‹ C. to effect degassing. Monomer may be applied directly or in liquid propane. In examples: (1) CaSO 3 ¢H 2 O is heated at 340‹ C. to remove water of crystallization, methyl meth-acrylate containing dissolved benzoyl peroxide is applied and the mixture is suspended in hexane and heated to 75‹ C. to effect polymerization, generally similar processes are carried out with (2) gypsum dihydrate and styrene; (3) calcium aluminate hydrate and methyl methacrylate; (4) Al 2 O 3 6H 2 O and methyl methacrylate. Comparison experiments with analogous non-foamed materials are given.