POSTOPEK ZA IZDELAVO STRJENIH PROIZVODOV

1,241,147. Unsaturated polyester compositions. SOC. ITALIANA RESINE S.p.A. 30 Dec., 1969 [31 Dec., 1968], No. 63355/69. Heading C3P. Stable, photochemically hardenable unsaturated polyester resin compositions contain (a) an unsaturated polyester resin consisting of (i) styrene monomer and (ii) a polyester which is a condensation product of a polycarboxylic acid and. a polyhydroxyl alcohol, the acid or the alcohol being non-aromatically unsaturated, and (b) a stabilizing system consisting of an alkyl phosphite or aryl phosphite, a quaternary ammonium salt and (c) a compound decomposing under the action of light, of the general formula R-SO 2 X, in which X stands for halogen and R represents an alkyl, phenyl, aralkyl, naphthyl or alkyl-naphthyl radical. In the examples the compositions contained polyesters derived from propylene glycol, fumaric acid and phthalic anhydride, triphenyl phosphite, styrene, hydroquinone, trimethyl benzyl-ammonium chloride and 2-naphthyl sulphonyl chloride and films are hardened by irradiation with ultraviolet light.