| 摘要 |
<p>A thermoplastic material comprises a copolymer of (a) 65-82 mole per cent of a styrene of formula <FORM:1100624/C3/1> where Rx is H, a methyl or methoxy radical and x is 0, 1 or 2, with (b) 18-35 mole per cent of at least one methacrylate of formula <FORM:1100624/C3/2> where R1 is a C1- 22 alkyl, C7- 22 aralkyl or C7- 22 phenoxyalkyl radical, the copolymer having a number average molecular weight of less than 7000. The copolymer may comprise (a) styrene or vinyl toluene and (b) methyl, ethyl, n-butyl, n-hexyl, n-decyl, stearyl and/or octadecyl methacrylates and may contain o-terphenyl as plasticizer. The copolymer may be produced by heating a solution of the monomers and a catalyst (#c,#c1-azodi-isobutyronitrile), e.g. in toluene, in the absence of oxygen and recovering the precipitated copolymer, e.g. by addition of methanol. The copolymers may be dissolved in benzene and used to coat a substrate to form a recording element.ALSO:A recording element has a substrate coated with a layer of a thermoplastic material comprising a copolymer of a) 65-82 mole % of a styrene of formula <FORM:1100624/B1-B2/1> where Rx is H1 a methyl or methoxy radical and x is 0, 1 or 2, with b) 18-35 mole % of at least one methacrylate of formula <FORM:1100624/B1-B2/2> where R1 is a C1-22 alkyl, C7-22 aralkyl or C7-22 phenoxy alkyl radical, the copolymer having a number average molecular weight of less than 7,000. The substrate may be of glass or may be flexible, e.g. of polyethylene terephthalate or of polycarbonate resin. The thermoplastic composition and substrate may be both optically clear and the substrate may be coated with a transparent conductive layer, e.g. of tin oxide or chromium.</p> |
