Japan Synthetic Rubber Co., Ltd.

Bridgestone Tire Company Limited

Noboru Ohshima

Yasumasa Takeuchi

Mitsuhiko Sakakibara

Yutaka Obata

Hozumi Sato

Kenya Makino

Akira Tsuji

Toshio Miyabayashi

Koei Komatsu

Takashi Nishioka

Tooru Shibata

Yoji Watabe

Katsuo Koshimura

Yoshito Yoshimura

Yutaka Iseda

Eitaro Okuya

Takayoshi Tanabe

Michio Ishii

Toshio Omori

Akinori Nishioka

Masaaki Watanabe

Kaoru Nakako

Masanobu Takahashi

Hiromichi Hara

Yoshikazu Torigoe

Funio Tsutsumi

Kouei Komatsu

Yozo Nakata, Deceased

A photo-sensitive resin composition is provided which contains (1) a particulate polymer of a carboxy-group-containing-diene having a cross-linked structure; (2) a polymer having two or more photo-polymerizable unsaturated groups at its molecular chain terminals, and, optionally, a photo-polymerizable unsaturated group, carboxyl group, hydroxy group, amino group, or epoxy group in side chains, or (2') a non-diene-type polymer having a photo-polymerizable unsaturated group, carboxyl group, hydroxy group, amino group, or epoxy group in side chains, or a low molecular weight linear diene-type polymer; (3) a photo-polymerizable unsaturated monomer; (4) a polymer containing an amino group; and (5) a photo-polymerization initiator. The photo-sensitive resin composition has excellent water-developing capability and shows almost no swelling in water, causing minimal reduction in strength and only minimal dimensional changes during development. Resin plates prepared from the composition possess excellent strength after exposure to light, excellent elongation at break, impact resilience and superb transparency, providing a good characteristic balance of properties.

Water developable photosensitive resin composition

High vinyl polybutadiene or styrene-butadiene copolymer obtained by polymerizing 1,3-butadiene alone or with styrene in a hydrocarbon solvent using an organolithium compound as an initiator and coupling the resulting polymer, characterized in that

High vinyl polybutadiene or styrene-butadiene copolymer

Styrene-butadiene random copolymers having an average vinyl content of at least 70%, a breadth of the distribution of vinyl contents of at least 20%, a Mooney viscosity (ML.sub.1+4, 100.degree. C.) of 10 to 150, and a styrene content of about 3 to 30% by weight. They are prepared by copolymerizing styrene and butadiene in a hydrocarbon solvent in the presence of an organolithium initiator and a Lewis base and, if necessary, an anionic surface active agent containing --SO.sub.3 M or --OSO.sub.3 M (wherein M is Na, K, Rb or Cs) under temperature-raising conditions. They are rubber materials having low rolling resistance and high wet skid resistance.

Styrene-butadiene random copolymer and process for the production thereof

A process for preparing polybutadiene having a 1,2-configuration content of 5-40% and a cis-1,4-configuration content of 60% or more, which comprises polymerizing 1,3-butadiene in the presence of a catalyst consisting of:

Process for preparing polybutadiene having a 1,2-configuration content

A polybutadiene rubber composition comprising (A) a polybutadiene rubber obtained by solution polymerization and having a Mooney viscosity (ML.sub.1+4.sup.100.degree. C.) of 60-110 and a 1,4-configuration content of not less than 60%, preferably not less than 70%, and (B) a polybutadiene polymer obtained by solution polymerization and having a viscosity-average molecular weight of 20,000-140,000, preferably 40,000-100,000, and a 1,4-configuration content of not less than 60%, preferably not less than 70%, in which composition the weight ratio of (A)/(B) is 100/5-100/150, preferably 100/35-100/100, and the Mooney viscosity (ML.sub.1+4.sup.100.degree. C.) of which composition is 20-70. This composition is high in tackiness in the unvulcanized state and also excellent in the physical properties of vulcanizate.

Polybutadiene rubber compositions

In the preparation of 1,2-polybutadiene with a vinyl content of at least 70% by contacting 1,3-butadiene with a catalyst consisting of:

Process for the preparation of 1,2-polybutadiene

A process for preparing conjugated diene polymers by either polymerization of one or more monomers selected from a group of conjugated diene compounds or copolymerization of a conjugated diene compound with an alkenyl aromatic compound, using an organolithium initiator in a hydrocarbon solvent, characterized in that the polymerization is carried out in the presence of

Process for preparing conjugated diene polymers

A process for producing a polymer having functional groups at its chain terminals, which comprises reacting a polymer having alkali metal atoms at its chain terminals with an alkylene oxide or sulfide in a hydrocarbon medium having a solubility parameter of 7.2 or less at 25.degree. C. This process makes it possible to produce the said polymer in a short period of time without necessitating a large power for agitation. According to this process, there can be produced a polymer having a functionality near the theoretical functionality in a short period of time.

Process for producing polymer having functional groups at its chain

Polydiene polyurethanes having high tear strength are obtained by using polydiene glycols, prepared with use of lithium-based catalyst, having a number average molecular weight of 1,000 to 5,000 and functionality of 1.8 - 2.1, diisocyanates and chain-extending agents, and by controlling chemical cross-link density being 4 .times. 10.sup.-5 mole/cc and less. When the chemical cross-link density is within the above range, elongation and tensile strength in addition to tear strength of the polyurethane are improved significantly. Furthermore, when 10 - 50 parts by weight of the specified carbon black are added to 100 parts by weight of the mixture of the prepolymer, the chain-extending agent and the additive prior to curing the prepolymer, these mechanical properties of the polyurethane are improved further.

Process for preparing high tear-strength polydiene polyurethane

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Suzuka, Japan

Noboru Ohshima