Japan Synthetic Rubber Co., Ltd.

Kohei Goto

Hiroharu Ikeda

Akira Iio

Yasuyuki Shimozato

Noboru Yamahara

Zen Komiya

Iwakazu Hattori

Hiroshi Oka

Kazuo Soga

Masao Hisatomi

Shoji Ogasahara

Masahiro Shibata

Yoshiyuki Michino

Takeshi Shiono

A process for producing a polybutadiene, which comprises polymerizing 1,3-butadiene in an inert organic solvent with a catalyst comprising (A) a cobalt compound, (B) an organoaluminum compound consisting essentially of an aluminoxane and, if necessary, (C) a tertiary phosphine compound, (D) at least one compound selected from the group consisting of an ester compound, an alcohol compound, a phenolic compound, a sulfoxide compound, a nitrogen-containing heterocyclic compound, water and a tertiary amine compound and (E) at least one compound selected from the group consisting of carbon disulfide, a xanthogen compound and a thioisocyanide. By this process, there can be produced, as desired, a cis-1,4-polybutadiene, a 1,2-polybutadiene having a desired vinyl content, a crystalline 1,2-polybutadiene or a polybutadiene containing crystalline 1,2-polybutadiene segments.

Process for producing polybutadiene

A transparent resin material consisting of a hydrogenation product of a (co)polymer obtained by subjecting at least one compound represented by general formula (I) or a combination of at least 5% by weight of said compound and 95% by weight or less of other copolymerizable cyclic olefin monomer to metathesis polymerization: ##STR1## wherein A and B are independently hydrogen atoms or C.sub.1-10 hydrocarbon groups; and X and Y are independently hydrogen atoms, C.sub.1-10 hydrocarbon groups, --C(CH.sub.2).sub.n COOR.sup.1 groups or --(CH.sub.2).sub.n OCOR.sup.1 groups [R.sup.1 is a C.sub.1-20 hydrocarbon group and n is 0 or an integer of 1-10] with the proviso that at least one of X and Y is selected from the above --(CH.sub.2).sub.n COOR.sup.1 and --(CH.sub.2).sub.n OCOR.sup.1 groups. Said transparent resin material is moldable and has sufficient optical properties, low hygroscopicity, good heat resistance and excellent adhesion to recording layer.

Transparent resin material

A transparent resin material consisting of a (co)polymer obtained by subjecting at least one compound represented by the general formula (I) or a combination of said compound and other copolymerizable monomer to metathesis polymerization, or a hydrogenation product of the (co)polymer: ##STR1## wherein A and B are independently hydrogen atoms or C.sub.1-10 hydrocarbon groups; X and Y are independently hydrogen atoms, C.sub.1-10 hydrocarbon groups, halogen atoms, halogen-substituted C.sub.1-10 hydrocarbon groups, --(CH.sub.2).sub.n COOR.sup.1, --(CH.sub.2).sub.n OCOR.sup.1, --(CH.sub.2).sub.n OR.sup.1, --(CH.sub.2).sub.n CN, --(CH.sub.2).sub.n CONR.sup.2 R.sup.3, --(CH.sub.2).sub.n COOZ, --(CH.sub.2).sub.n OCOZ, --(CH.sub.2).sub.n OZ or --(CH.sub.2).sub.n W [R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently C.sub.1-20 hydrocarbon groups, Z is a halogen-substituted hydrocarbon group, W is SiR.sub.p.sup.5 D.sub.3-p (R.sup.5 is a C.sub.1-10 hydrocarbon group, D is a halogen atom, --OCOR.sup.5 or --OR.sup.5, p is 0 or an integer of 1-3), n is 0 or an integer of 1-10] with the proviso that at least one of X and Y is selected from the above groups other than the hydrogen atom and the hydrocarbon groups, or X and Y may form together ##STR2## and m is 0 or 1. Said transparent resin material is moldable and has sufficient optical properties, low hygroscopicity, good heat resistance and excellent adhesion to recording layer.

A rubber composition consisting essentially of a dispersion in which particles of a high-melting isotactic poly-.alpha.-olefin having a melting point of at least 150.degree. C. are uniformly dispersed in a rubber matrix, said particles having an average particle size of not more than 200.mu., has a high modulus of elasticity and also excellent tear resistance. Such rubber composition can be obtained, for example, by mixing fine powder of said isotactic poly-.alpha.-olefin having an average particle size of not more than 200.mu. with a rubber solution, dispersing the particles uniformly in said rubber solution and recovering a rubber composition from the dispersion.

Rubber composition having high modulus of elasticity and process for

When an elastomeric copolymer of a C.sub.4 or C.sub.5 conjugated diene and an aromatic vinyl compound is brominated in latex while keeping the uniformity of the latex until the amount of bormine combined with the copolymer reaches 0.5-15% by weight, the resulting brominated conjugated diene-aromatic vinyl compound rubber contains 3-80% by weight of a toluene-insoluble fraction formed by the bromination and has a high green strength and a good processability. A vulcanized rubber obtained from said brominated rubber has a high modulus of elasticity and a high tensile strength. When an anionic surfactant is used as an emulsifier, the uniformity of the above-mentioned latex can be kept by adjusting the pH value of the bromination reaction system to 9 or highter, preferably 10 or higher, during the reaction or by auxiliarily adding a nonionic surfactant. When a cationic or nonionic surfactant is used as an emulsifier, regulation of pH is unnecessary.

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Yokkaichi, Japan

Kohei Goto