GB532022A - Improvements in and relating to synthetic resins and to articles made therefrom - Google Patents

Abstract

532,022. Vinyl polymerization products. NORTON GRINDING WHEEL CO.. Ltd. May 8, 1939, No. 14810/40. Convention date, May 7, 1938. Divided out of 531,956. [Class 2 (iii)] A transparent synthetic resin, susceptible to optical grinding and polishing, is obtained by polymerizing by known methods a mixture of styrene with a miscible amount of acrylic or methacrylic anhydride or allyl or alphasubstituted allyl acrylate or methacrylate. Specified alpha-substituted allyl esters are the methyl, ethyl, propyl, butyl, allyl, cyclohexyl, phenyl. tolyl or furyl esters. To modify refractive index or dispersion value, a further polymerizable substance may be included in the mixture, e.g. a co-polymer of methyl methacrylate, styrene and allyl methacrylate may be formed. Other specified additional polymerizable substances are acrylic and methacrylic esters of hydroxy-quinolines, hydroxydiphenyls, nitrophenols and chlorophenols ; nitroethylene , triphenylmethyl acrylate or methacrylate; o, m, or pnitrostyrene, vinyl chloride, and vinyl acetate. The change in refractive index or dispersion value is approximately proportional to the amount of added substance. Optical elements may be formed from the polymers by moulding under heat and pressure in polished moulds. Spectacle lenses may be secured to nose pieces and bows made of similar compounds. Lenses made from the interpolymers may be combined with silicate glass lenses to produce new optical systems. Colour may be imparted e.g. for light filters or protective eye glasses, by employing acrylic acid resins which are naturally coloured or by the use of dyestuffs soluble in the monomer.