Abstract: 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.

Abstract: 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(1) the polybutadiene or styrene-butadiene copolymer comprises at least 20% by weight of a polymer having in its molecular chain a linkage between butadienyl and at least one metal selected from the group consisting of silicon, germanium, tin and lead,(2) the styrene content of said copolymer is 40% by weight or less, and(3) the polybutadiene or the butadiene portion of the styrene-butadiene copolymer has a vinyl content of 50 to 95%.Said polybutadiene or styrene-butadiene copolymer has low rolling resistance, high wet skid resistance, highly improved fracture property and, an excellent processability.

Abstract: 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.

Abstract: 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:(A) a cobalt compound,(B) at least one member selected from the group consisting of:(i) a trialkylaluminum,(ii) a reaction product of a trialkylaluminum and an alcohol or water,(iii) a mixture of a trialkylaluminum and a dialkylaluminum halide,(iv) a dialkylaluminum hydride, and(v) an organolithium compound, and(C) at least one compound selected from the group consisting of phenyl isothiocyanate and carbon disulfide, in a hydrocarbon or halogenated hydrocarbon solution of a high cis-1,4-polybutadiene obtained by polymerizing 1,3-butadiene with a catalyst consisting of:(D) at least one compound selected from the group consisting of the organocarboxylates of nickel and organic complex compounds of nickel,(E) at least one compound selected from the group consisting of boron trifluoride, boron tr

Abstract: 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.

Abstract: 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:(A) a cobalt compound,(B) an organic phosphine compound,(C) a trialkylaluminum compound, and(D) water in an amount of 0.1 to 1.2 moles per mole of said trialkylaluminum,in the presence of a molecular weight regulator,(E) an alkylaluminum halide compound is used as the molecular weight regulator in an amount of at least 0.01 mole per mole of the trialkylaluminum compound (C), whereby 1,2-polybutadiene with a regulated molecular weight can be produced without causing decreased polymerization activity and change of vinyl content and crystallinity of the produced polymer. The alkylaluminum halide compound (E) is preferably used in an amount of 0.05 to 1.0 mole per mole of the trialkylaluminum compound (C).

Abstract: 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(1) one or more anionic surface active agent having a group --SO.sub.3 M or --OSO.sub.3 M (where M is an alkali metal) and(2) one or more Lewis bases.

Abstract: 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.

Abstract: 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.