Abstract: A continuous sheet having a three-dimensional pattern providing the optical functions is produced by the use of a release sheet of a curable resin on which the three-dimensional pattern is formed, a change in a surface-gloss of a layer of the release sheet on which the three-dimensional pattern is formed, is not more than 30% in pressing a hot plate heated to 160° C. under a force of 20 kg/cm2 for 3 seconds and the release sheet may be wound in a form of cylinder of not more than 12 inches in diameter. In accordance with the present invention, it is possible to enhance a degree of freedom of processing conditions and thermoplastic resins to be used and to produce a continuous sheet having high performance optical functions efficiently.

Abstract: A continuous sheet having an optical function imparted thereto, which is obtained by extruding a thermoplastic resin on a three-dimensional pattern side of a continuous release sheet having a three-dimensional pattern in its surface to shus transfer said pattern to a surface of said thermoplastic resin, simultaneously contacting the other side of said thermoplastic resin with a cooling roll having an uneven pattern or a mirror surface to thus transfer said pattern or mirror surface to a surface of said thermoplastic resin in contact with said cooling roll, and separating by peeling said release sheet from said thermoplastic resin after cooling. The continuous sheet is free of a streak and scratch and freely cuttable in any desired size and form.

Abstract: A prism sheet having a plurality of substantially triangular prism-shaped lens units with their longitudinal axes almost parallel to each other arranged on one side and having the other side roughened, and with a characteristic value of 100 when said roughned side is smooth, the characterstic values are not less than 50 in glossiness, not more than 70 in internal reflective ability, and not more than 70 in friction coefficient when the plane including the prism peaks is rubbed by the roughened surface. The prism sheet of the present invention is therefrom free from interference fringes, substantially safe from scratching and uniform and high in brightness, being thus useful for liquid crystal devices etc.

Abstract: A polyamide acid composition for preparing a polyimide which is improved in the stability in a form of solution and can extend the pot life of the composition comprising a solution of a polyamide acid in an organic solvent, the polyamide acid being a precursor of the polyimide, and an N-substituted heterocyclic compound as a chemical treating agent which can lower a rate of conversion of the polyamide acid to the polyimide. The pot life can be extremely extended to give the composition an enough flowability for a long time without reducing the excellent properties such as a heat resistance of the obtained polyimide.

Abstract: A polyamide acid composition for preparing a polyimide which can extend the pot life of the composition comprising a solution of a polyamide acid in an organic solvent, the polyamide acid being a precursor of the polyimide, a dehydrating agent, a catalyst and a pot life extending agent which can lower a rate of conversion of the polyamide acid to the polyimide, and the process for preparing the polyimide from said polyamide acid composition. According to the present invention the pot life can be extremely extended to give the composition an enough flowability for a long time without reducing the excellent properties such as a heat resistance and an electric insulation of the obtained polyimide.

Abstract: A thermoplastic resin composition consisting essentially of homopolymer or copolymer of polyvinyl chloride and a graft copolymer of a monomer mixture consisting essentially of alkyl methacrylate, aromatic vinyl compound, unsaturated nitrile and monovinylidene compound copolymerizable therewith, grafted to an aqueous elastomeric dispersion of alkyl acrylate, or a mixture of alkyl acrylate and mono vinylidene compound and a multi-functional cross-linking agent and of which the particles are agglomerated before or during the graft polymerization process, and process of manufacturing the same.

Abstract: A vinyl chloride resin composition consisting essentially of a vinyl chloride polymer or copolymer of 70% or more by weight vinyl chloride and 30% or less by weight of one or more monomers copolymerizable therewith and a graft copolymer prepared by graft copolymerizing one or more monomers selected from alkyl methacrylate, vinyl aromatic compound and unsaturated nitrile, in the presence of an aqueous dispersion of alkyl acrylate elastomer obtained by copolymerizing an allyl ester of vinyl or vinylidene unsaturated alpha-carboxylic acid and alkyl acrylate.

Abstract: A two stage emulsion polymerization process for preparing resins having both weather resistance and impact resistance. In the first step, there are copolymerized 100 to 80% by weight of an alkyl acrylate having alkyl containing 2 to 8 carbon atoms; 0 to 20% by weight of a monomer containing a vinylidene group copolymerizable therewith and cross-linking monomer to produce an aqueous dispersion of cross-linked copolymer having degree of swelling above 10, gel content above 80% and average particle size of 0.15 to 0.5 microns. Emulsifier in an amount of 0.05 to 1 % by weight is used. In the second step, 5 to 50 parts by weight of the solid copolymer of the cross-linked polymer of step 1 is polymerized in the presence of 50 to 95 parts by weight of a monomer mixture of at least 50% by weight of aromatic vinyl monomer and less than 50% by weight of vinyl monomer copolymerizable therewith.