Abstract: A radiation sensitive resin composition comprising:(A) an alkali-soluble copolymer comprising:(a) 10 to 50% by weight of a first unit consisting of a radical polymerizable compound having a carboxylic group,(b) 20 to 60% by weight of a second unit consisting of a radical polymerizable compound having a cycloalkyl group, the unit containing no carboxyl group, and(c) 5 to 40% by weight of a third unit consisting of a radical polymerizable compound other than the radical polymerizable compounds in (a) and (b) above;(B) a polymerizable compound having at least one ethylenically unsaturated double bond; and(C) a radiation sensitive radical initiator. Also is disclosed a material for forming bumps containing the radiation sensitive resin composition. The radiation sensitive resin composition has sufficient developability with an alkali developer and sufficient resolution when the composition is in the form of a 20 .mu.m or more thick film.

Abstract: A liquid curable resin composition containing urethane bond at a concentration of 2.0.times.10.sup.-3 mole/gm or more and comprising:(a) a urethane (meth)acrylate having at least three cyclic structures in the molecule;(b) a polymerizable mono-functional vinyl monomer of which the homopolymer has a glass transition point of 50.degree. C. or more; and(c) a polymerization initiator.The liquid curable resin composition possesses a high Young's modulus, exhibits very little contraction stress, has high tenacity and good curing characteristics. Along with these superior characteristics, the high reliability of the composition makes it a suitable coating material for optical fiber. Furthermore, since the resin composition possesses a high Young's modulus and high tenacity, it is also useful as a protective coating material for metals, plastics, wood, ceramics, glass, and the like.

Abstract: A curable liquid resin composition comprising a urethane (meth)acrylate polymer obtained by reacting:(A) a polyol compound containing as structural units groups which are represented by formulae--CH.sub.2 CH.sub.2 O-- or--CH.sub.2 CH(CH.sub.2 CH.sub.3)O--;(B) a polyisocyanate compound; and(C) at least one (meth)acrylate compound containing a hydroxyl group and coated articles produced therefrom.

Abstract: A liquid photocurable plastic composition is disclosed which comprises:(a) from 14% to 70% by weight of a polyurethane (meth)acrylate having a polyoxyalkylene structure in the backbone of the polyurethane, said polyurethane (meth)acrylate containing 0.8 to 8 weight percent of ethylenic unsaturation, from 50% to 98% by weight of the polyoxyalkylene structure, and having a number average molecular weight of 1,000 to 7,000;(b) from 5% to 40% by weight of a polyurethane (meth)acrylate having at least 15% by weight of a tricyclodecane structure in the backbone of the polyurethane and a number average molecular weight of from 500 to 1,000;(c) a reactive diluent; and(d) a polymerization initiator.

Abstract: A radiation-curable coating composition adapted for the coating of optical glass fiber, comprising an ethylenically unsaturated polyurethane which is the reaction product of:(A) a polyether diol having a molecular weight in the range of 200 to 8,000 and a structural unit represented by the formula: ##STR1## in which R.sup.1 -R.sup.4 are each independently selected from hydrogen and an alkyl group containing from 1-4 carbon atoms, such as a polymer of copolymer of methyl tetrahydrofuran;(B) a polyisocyanate compound, preferably a diisocyanate; and(C) a polymerizable ethylenically unsaturated compound having a single hydroxy group, such as a monohydric acrylate;there being employed per equivalent of hydroxy in component (C) from 1.1 to 2 equivalents of said polyisocyanate with the balance of the isocyanate groups being reacted waith the hydroxy groups of said diol.

Abstract: A curable resin composition adapted for bundling coated optical fibers comprises:(A) polyetherpolyurethanes of at least one kind having an ethylenically unsaturated group and containing from 40% to 85%, by weight, of a tetramethyleneoxy structure in the entire structure thereof;(B) ethylenically unsaturated monomer; and(C) a photopolymerization initiator. This resin composition, when cured, has a coefficient of dynamic friction with polyethylene of not more than 0.4, and is thus specially adapted for use in holding together coated optical fibers in a tape-like structure.

Abstract: A curing apparatus utilizing ultraviolet radiation for curing a coating over the surface of a line-shaped medium such as an optical fiber, comprising: a pair of reflecting mirrors, each of which has an elliptical mirror surface, the ratio between the major and minor axes of which is within a range from 1.02 to 1.35; a source for producing ultraviolet radiation having a tube which is disposed along a first focal axis of the pair of reflecting mirrors for emitting ultraviolet radiation and has a diameter within a range from 12 mm to 24 mm and a light emission length equal to or longer than 15 cm; and an ultraviolet radiation transmission hollow tube which is disposed along a second focal axis of the pair of reflecting mirrors and through which the line shaped medium is passed in the axial direction of the hollow tube. The ultraviolet radiation emitting tube is air-cooled.

Abstract: Polymers or copolymers of norbornene derivatives can be produced by contacting in the presence or absence of an inert solvent at least one norbornene derivative substituted by at least one polar group selected from the group consisting of ester, ether, nitrile, amide, imide, acid anhydride, halogen, and silyl, or by at least one substituent having one of said polar groups; or a combination of said norbornene derivative with at least one member selected from the group consisting of cycloalkenes having no polar substituent and polymers having olefinic carbon-to-carbon double bonds; with a catalyst consisting essentially of (a) at least one coordination compound of W or Mo, the oxidation number of which is 2, 1 or 0, (b) at least one titanium tetrahalide and, if necessary, (c) at least one compound selected from the group consisting of componds having an electron-accepting .pi. bond, N-halogen-substituted cyclic acid imides, sulfides, sulfoxides and phosphines.