摘要 |
1513993 Unsaturated polyester resin syrup compositions H H ROBERTSON CO 1 Sept 1976 [16 March 1976] 36118/76 Heading C3R A semisolid polymerizable composition comprises the unpolymerized reaction product of one part by weight of unsaturated polyester resin syrup comprising a mixture of unsaturated polyester resin and ethylenically unsaturated monomer, 0À1-1À5 parts by weight of an aqueous alkali-stabilized colloidal silica and 0À2-4À0 parts by weight of calcium sulphate hemihydrate, the amount of said calcium sulphate hemihydrate being sufficient to combine with at least 85% by weight of the water which is contained in the other ingredients of the composition. The specific examples describe compositions in which the unsaturated polyester resin syrup is a mixture of styrene and an unsaturated polyester formed from phthalic anhydride, maleic anhydride and propylene glycol and optionally including as a filler alumina trihydrate. |