Japan Synthetic Rubber Co., Ltd.

Ituo Nishiwaki

Shin-ichiro Iwanaga

Hiroji Enyo

Tatsuaki Matsunaga

Akira Iio

Masatoshi Arakawa

Naoki Andoh

A conjugated diene copolymer comprising (A) 40 to 90 mole % of a conjugated diene component, (B) 0.5 to 10 mole % of an alpha,beta-ethylenically unsaturated carboxylic acid component, (C) 0.1 to 5 mole % of a polyfunctional alkenyl compound component and (D) 5 to 58 mole % of a monoolefinically unsaturated compound component wherein the intrinsic viscosity [.eta.] of the copolymer as measured at 30.degree. C. in dimethylformamide is 0.01 to 3.0 dl/g, the width (.DELTA.Tg) of the endothermic transition temperature section determined by a differential scanning calorimetry is 45.degree. to 120.degree. C., and the limit temperature (T.sub.1) on the lower temperature side of the endothermic transition temperature section is -40.degree. C. or less. This copolymer, when combined with a photopolymerizable unsaturated monomer and a photosensitizer, provides a photosensitive resin composition which is soluble in aqueous alkali solutions, has an excellent processability and a photocurability, has an excellent rubber elasticity and a transparency even after curing, and has excellent water resistance.

Conjugated diene copolymer, process for producing the same, and

A conjugated diene copolymer comprising (A) 40 to 90 mole % of a conjugated diene component, (B) 0.5 to 10 mole % of an alpha,beta-ethylenically unsaturated carboxylic acid component, (C) 0.1 to 5 mole % of a polyfunctional alkenyl compound component and (D) 5 to 58 mole % of a monoolefinically unsaturated compound component wherein the intrinsic viscosity [.eta.] of the copolymer as measured at 30.degree. C. in dimethylformamide is 0.01 to 3.0 dl/g, the width (.DELTA.Tg) of the endothermic transition temperature section determined by a differential scanning calorimetry is 45.degree. to 120.degree. C. and the limit temperature (T.sub.1) on the lower temperature side of the endothermic transition temperature section is -40.degree. C. or less. This copolymer, when combined with a photopolymerizable unsaturated monomer and a photosensitizer, provides a photosensitive resin composition which is soluble in aqueous alkali solutions, has an excellent processability and a photocurability, has an excellent rubber elasticity and a transparency even after curing, and has excellent water resistance.

Methacrylic acid is produced from methacrolein by gaseous phase oxidation in a very high selectivity, when methacrolein, molecular oxygen-containing gas and steam in a molar ratio of methacrolein:molecular oxygen:steam of 1:1-3:0-50 are subjected to reaction at a temperature in the range of 250.degree. to 400.degree. C., at a space velocity of 250 to 3,000 hr.sup.-1 (at 0.degree. C. and 1 atm.) with a novel catalyst having the following composition formula in atomic ratio:

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Yokkaichi, Japan

Ituo Nishiwaki