| 摘要 |
1329598 Matt surfaced polystyrene film OJI YUKA GOSEISHI KENKYUJO KK 27 Nov 1970 [28 Nov 1969 12 March 1970 26 Aug 1970] 56462/70 Heading B5B Drawn polystyrene film containing elastomeric particles of size 0À1-10 Á (e.g. of polybutadiene or poly-(butadiene - styrene) and which may be grafted on to the polystyrenes) is given a matt surface by treatment with a liquid having solvent action on the polystyrene and swelling action on the particles, followed by positively stopping the action of the liquid. Stopping may be with a non-solvent (e.g. methanol) at least partially miscible with the liquid or by cooling the film below the temperature at which the liquid affects it. Liquids exemplified are heptane, hexane and octane and may also contain chlorobenzene, toluene or benzene to modify their efficacy. Cooling may be effected with polished, cooled squeeze-rollers. The liquid may be floated on water and the film passed through the floating layer before cooling. The product of transverse and longitudinal elongations in the drawn film should be at least 6, but is not so restricted provided treatment is between 30‹ C. and the deformation temperature of the film, cooling below 40‹ C. is used to stop the solvent/swelling action, and the liquid satisfies a given equation relating to its solvent power. In examples is used an ABS resin or high-impact polystyrene containing butadiene and optionally blended with high-impact polyethylene. |
