herdat, possibly fiberarmerat, foremal with law of shrinkage, erhallet by polymerisation in verme and pressure of a pulp comprising a eteniskt omettad, fornetbar polyester, a eteniskt omettad monomer and...

摘要

1276198 Unsaturated polyester compositions ROHM & HAAS CO 10 Oct 1969 [23 Oct 1968] 49934/69 Heading C3P A liquid polymerizable resin composition, capable of use in moulding compounds polymerizable under the influence of heat and pressure to give products of low shrinkage, comprises (a) 20 to 80% by weight of the total of (a), (b) and (c) of an ethylenically unsaturated cross-linkable polyester having a molecular weight per double bond factor of 142 to 215, (b) 20 to 80% by weight of the total of (a), (b) and (c) of an ethylenically unsaturated monomer, and (c) 1 to 25% by weight of the total of (a), (b) and (c) of a thermoplastic addition polymer containing 0À1 to 5% by weight of the polymer of acid groups, soluble in (b) or in mixtures of (a) and (b), the resin composition being polymerizable to form a non-homogenous polymeric system. In the examples the compositions comprise unsaturated polyesters prepared from propylene glycol, maleic anhydride, dipropylene glycol, fumaric acid, o-phthalic acid and ethylene glycol; styrene, vinyltoluene, tert-butyl styrene, methyl methacrylate and chlorostyrene; thermoplastic polymers prepared from methyl methacrylate, ethyl acrylate and acrylic acid; calcium carbonate, glass fibres, calcium hydroxide, zinc stearate and magnesium hydroxide and cured using tertbutyl perbenzoate.