Abstract: A cladding material for plastic optical fibers is disclosed. The cladding material comprises mainly a copolymer comprising a fluoroalkyl methacrylate and an N-aliphatic maleimide as monomer units. The cladding material has low refractive index and high thermal stability, so that an optical fiber with a large acceptance angle can be obtained.

Abstract: A plastic lens formed from a copolymer of three components. A first component which is a vinyl monomer having a nucleus-halogen-substituted aromatic ring. A second component which is selected from at least one member of the group consisting of aliphatic diacrylate, dimethacrylate, triacrylate, and trimethacrylate. A third component is chosen from mono-acrylate or mono-methacrylate having a nucleus-halogen substituted aromatic ring. The components are present in the weight ratio of 20/15/0 to 85/80/60 weight percent, respectively.

Abstract: A plastic lens formed from a copolymer of three components. A first component which is a vinyl monomer having a nucleus-halogen-substituted aromatic ring. A second component which is selected from at least one member of the group consisting of aliphatic diacrylate, dimethacrylate, triacrylate, and trimethacrylate. A third component is chosen from mono-acrylate or mono-methacrylate having a nucleus-halogen substituted aromatic ring. The components are present in the weight ratio of 20/15/0 to 85/80/60 weight percent, respectively.

Abstract: A polymer obtained by polymerizing a urethanized acrylic or methacrylic monomer obtained by reacting the hydroxyl group of an acrylic or methacrylic monomer having a nucleus-halogen-substituted aromatic ring and a hydroxyl group with the isocyanate group of a polyfunctional isocyanate is excellent and has a high refractive index. Accordingly, this polymer is valuable as a resin material for a plastic lens.

Abstract: Highly refractive urethane polymers for use in optical lenses and the lenses produced therefrom are obtained by polymerizing at least one unsaturated urethane compound which is the reaction product of at least one xylylene diisocyanate and at least one compound selected from the group comprising: ##STR1## where: R.sub.1 is either H or CH.sub.3R.sub.2 is a remnant radical of a substituent or non-substituent hydrocarbon having 2-4 carbon atoms; ##STR2## where: R.sub.3 is either H or CH.sub.3m=2-5;CH.sub.2 =CH--CH.sub.2 --OH; and 3(CH.sub.2 =CH--CH.sub.2 --O--CH.sub.2).sub.2 CHOH.

Abstract: Polyurethane resins and polyurethane coating compositions are provided which exhibit enhanced resistance to weather. The resins comprise the reaction product obtained from reacting a polyol with 1,6,11-undecanetriisocyanate. The resin composition herein disclosed is readily adapted for use in either a one component-heat curing system or in a two component-polyol hardening system. In the one component system, the isocyanate group of the isocyanate compound is blocked by a blocking agent so as to ensure stability of the coating at room temperature. After application, the coating resin is heated to effect reaction of a hydroxyl group from the polyol with an isocyanate group to cause hardening of the film. In the two component system, the polyol-pigment liquid, liquid "A", is mixed with the trifunctional isocyanurate compound (above noted) and solvent, liquid "B".

Abstract: Polyurethane resins with an excellent weather resistance are provided by the reaction of polyols with trifunctional isocyanates which are expressed by the following general formula: ##STR1## (R=a remnant of divalent hydrocarbon group with carbon number of 2 or 3) The reaction between a polyol and a trifunctional isocyanate is effectuated at an NCO/OH mole percentage of 0.5 to 2.0, and adjustments are made so that the concentration of carbamide group will be 5.times.10.sup.-4 to 50.times.10.sup.-4 moles per gram of the reaction product, and that the bridging parameter will be 150 to 1,500.The resins may be used to best advantage as polyurethane resin coatings excelling in weather resistance.

Abstract: A polymer dispersed liquid is prepared by the following steps: (1) polymerzing at least two different types of monomers of the vinyl series in the presence of a block or graft copolymer of the vinyl series containing a component solvating in a dispersion medium (.alpha.) and a component not solvating in the dispersion medium, but being compatible with a dispersed polymer (.beta.) in an organic liquid in which a copolymer of the vinyl series to be produced is soluble; then at that time, uniformly admixing an alkylated melamine-formaldehyde reaction product before, during or after the polymerization, (2) distilling out a part of the organic liquid, thereby varying the solubility parameter of the organic liquid of said polymer solution by more than about 0.5.