Showing papers on "Magnesium peroxide published in 1968"

Improvements in or relating to moulding compositions

Abstract: A storable heat-hardenable dry moulding composition comprises an unsaturated polyester resin component which is wholly or partially crystalline, an oligomer-containing prepolymer component, a peroxide polymerization catalyst to harden the moulding composition under the influence of heat, and a filler material The oligomer-containing pre-polymer component is a component comprising an oligomer dissolved in monomers containing vinyl and/or allyl groups derived by a peroxide catalyzed pre-polymerization at an elevated temperature of a monomer containing at least two vinyl and/or allyl groups with or without other monomers containing vinyl and/or allyl groups After the pre-polymerization there is still monomer present The composition may also include a lubricant of mould-release agent, a fire-extinguishing agent, a colouring agent or a fibrous filler material In Examples: suitable crystalline polyesters referred to are (1) ethylene-glycol fumarate, (2) neopentyl-glycol fumarate, (3) mixed polyester of fumaric and adipic acids and butane-1,4-diol; a suitable amorphous polyester resin is (4) one of oxyethylated Bisphenol A and fumaric acid; oligomer-containing cross-linking solutions are prepared from (5) diallyl phthalate, (6) diallyl phthalate and styrene and (7) diallyl phthalate and vinyl stearate, all using benzoyl peroxide as catalyst In Example 8, a composition is prepared from the crystalline polyester of Example 1, the amorphous polyester of Example 4, the oligomer-containing prepolymer of Example 5, tert-butyl perbenzoate, aluminium stearate and chalk, glass fibres being incorporated before the composition is rolled into a sheet In Example 9, are used the polyesters of Examples 2 and 4, the pre-polymer of Example 6, tert-butyl perbenzoate, magnesium peroxide and chalk, glass fibres being incorporated In Example 10 are used the polyester of Example 3, the prepolymer of Example 6, tert-butyl perbenzoate, magnesium peroxide, aluminium stearate, chalk, chlorinated paraffin and antimony trioxide, fine cotton fabric shreds being incorporated