Denka Company Limited

Denki Kagaku Kogyo Kabushiki Kaisha

Uichiro Yamagishi

Yasushi Abe

Shogo Hagiwara

Yuhei Ishigaki

Toshiaki Miyauchi

Wataru Nishino

Suguru Onuki

Kosuke Fujimoto

Takahiro Kozuka

Masao Onozuka

Takashi Aizawa

Hideki Toya

Satoru Ikari

Takashi Tachiyama

Disclosed are a polymer having a narrow molecular weight distribution prepared by living radical and a polymer manufacturing method comprising a step of performing living radical polymerization using 0.005 to 0.5 parts by mass of an oxygen radical scavenger per 100 parts by mass of a radical polymerizable monomer.

Polymer manufacturing method

To provide a statistical copolymer containing a chloroprene monomer unit and an unsaturated nitrile monomer unit which has a satisfactory oil resistance. A method for producing a statistical copolymer containing a chloroprene monomer unit and an unsaturated nitrile monomer unit includes a step for conducting continuous addition or 10 cycles or more of intermittent portionwise addition of the chloroprene monomer after initiation of a polymerization reaction is provided. A rubber composition using a statistical copolymer according to the invention or a vulcanized molded article containing the rubber composition is excellent in terms of oil resistance, mechanical strength, compression set at a low temperature and flex fatigue resistance.

Method for producing statistical copolymer containing chloroprene monomer unit and unsaturated nitrile monomer unit, statistical copolymer, latex and use of same

Disclosed is a block copolymer including one or more blocks of an acrylate polymer and one or more blocks of a chloroprene polymer, wherein the number average molecular weight of the block copolymer is 110,000 or more, the number average molecular weight of the block of a chloroprene polymer is 80,000 or more in total, and the block copolymer has a functional group with a structure represented by the following chemical formula (1) or (2): wherein in the chemical formula (1), Rrepresents hydrogen, chlorine, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group or a substituted, or unsubstituted heterocyclyl group.

Block copolymer and production method for block copolymer

To provide a block copolymer that includes an aromatic vinyl compound polymer and a chloroprene polymer, has a number average molecular weight of 100,000 or more, is preferred for a rubber composition and an adhesive composition, and is suitable for industrial production. A block copolymer includes at least one aromatic vinyl compound polymer block and at least one chloroprene polymer block, has a functional group with a structure represented by Chemical Formula (1) or (2), and has a number average molecular weight of 100,000 or more. The chloroprene polymer block has a number average molecular weight of 80,000 or more in total. (In Chemical Formula (1), Ris hydrogen, chlorine, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclyl group.)

Block copolymer and method for producing block copolymer

Provided is a chloroprene-based polymer having an industrially applicable sufficient molecular weight and capable of obtaining a vulcanized rubber excellent in durability and fatigue endurance and an adhesive excellent in layer separation resistance. A chloroprene-based polymer having a number average molecular weight Mn of 150000 to 300000 and comprising a functional group of a structure represented by the general formula (1) or (2) below: (wherein in the general formula (1), R1 shows hydrogen, chlorine, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclyl group.)

Chloroprene polymer and production method therefor

To provide a chloroprene rubber composition providing good permanent compression set and excellent mechanical strength, a vulcanizate of the composition, and a molded article of the composition. A chloroprene rubber composition including a chloroprene rubber and a natural rubber in a total amount of 100 parts by mass, a copolymer of styrene and butadiene in an amount of 0.1 to 10 parts by mass, ethylene thiourea in an amount of 0.1 to 3.0 parts by mass, and dipentamethylenethiuram tetrasulfide in an amount of 0.1 to 3.0 parts by mass is vulcanized after or during molding of the composition to yield a vulcanized molding.

Chloroprene rubber composition, and vulcanizate and molding thereof

Provided are a blended rubber and a blended rubber composition that give a vulcanizate superior in abrasion resistance and ozone resistance, and a vulcanizate prepared by vulcanizing the blended rubber composition. A blended rubber, comprising 30 to 93 mass % of a chloroprene rubber, 5 to 50 mass % of a soft polyvinyl chloride, and 2 to 20 mass % of an acrylonitrile-butadiene rubber. The polyvinyl chloride resin used preferably has a polymerization degree of 300 to 3000 and the acrylonitrile-butadiene rubber preferably has an acrylonitrile content of 18 to 50 mass %.

Blended rubber, blended rubber composition and vulcanizate

To provide a chloroprene rubber composition that provides excellent low temperature characteristics such as low temperature permanent compression set and dynamic characteristics at low temperature and provides good permanent compression set, mechanical strength, and processing characteristics also at high temperature thus to achieve excellent characteristics within a wide temperature region, and a vulcanizate and a molding thereof. To a chloroprene rubber including a 2,3-dichlorobutadiene unit in an amount of 5 to 20% by mass, a natural rubber is added so as to give a ratio (chloroprene rubber/natural rubber) of 60/40 to 95/5 by mass ratio. Then, with respect to 100 parts by mass of the rubber components, ethylene thiourea is added in an amount of 0.1 to 3.0 parts by mass and dipentamethylenethiuram tetrasulfide is added in an amount of 0.1 to 3.0 parts by mass, thereby preparing the chloroprene rubber composition.

Chloroprene rubber composition, and vulcanizates and moldings thereof

To provide an acrylic rubber composition and its vulcanized product, having excellent workability and an excellent balance of the vulcanization properties, the reduction of scorching, the rubber mechanical properties, the compression set and the heat resistance. An acrylic rubber composition comprising a carboxy group-containing acrylic rubber, a novolac phenol resin salt of a diazabicycloalkene compound and a polyamine compound. Particularly, the diazabicycloalkene compound is preferably 2,3,4,6,7,8,9,10-octahydropyrimido(1,2-a)azepine or 2,3,4,6,7,8-hexahydropyrrolo(1,2-a)pyrimidine, and the polyamine compound is preferably an aromatic polyamine or an aliphatic polyamine.

Acrylic rubber composition and vulcanized product thereof

Provided is a chloroprene rubber superior in the effectiveness of preventing mold staining. The chloroprene rubber contains at least one compound selected from phosphite ester compounds (such as tris(nonylphenyl)phosphite ester and tributyl phosphite ester) and phosphate ester compounds (such as tri(nonylphenyl)phosphate ester and tributyl phosphate ester) in a total amount of 0.1 to 5.0 mass % and additionally at least one compound selected from sulfonic acid compounds (such as benzenesulfonic acid and dodecylbenzenesulfonic acid) and fatty acid compounds in a total amount of 0.1 to 3.0 mass %.

Chloroprene rubber and chloroprene rubber composition

Provided are a chloroprene rubber, a chloroprene rubber composition and the vulcanizate and formed body thereof superior in low-temperature properties. A chloroprene rubber is obtained by emulsion polymerization of raw monomers containing antiperiplanar trans-1-chlorobuta-1,3-diene and cis-1-chlorobuta-1,3-diene in a total amount of 0.5 mass % or more, 2,3-dichlorobuta-1,3-diene in an amount of 2.0 mass % or more, and the rest being chloroprene. A composition containing the chloroprene is vulcanized into a formed body.

Chloroprene rubber, chloroprene rubber composition, vulcanizate thereof, and formed body

Provided is an acrylic rubber composition including an acrylic rubber and a functionalized silicone oil. Here, the functionalized silicone oil preferably has a particular polydimethylsiloxane structure having at least one binding site bonded with at least one of a monoamino group, a diamino group, a polyether group, an epoxy group, an alicyclic epoxy group, a hydroxyl group, a thiol group, a carboxyl group, a hydrogen group (Si&#x2014;H group), a methacryl group, a phenol group, an alkoxy group, an ester group, an amide group, an alkyl group, a fluoroalkyl group, and a diol group and has a functional group equivalent weight of 1 to 100,000 (g/mol). The composition is unlikely to be deteriorated even when it is exposed to high temperature for a long time and that has excellent heat resistance and a crosslinked product of the composition. The composition is unlikely to be deteriorated even when it is exposed to high temperature for a long time and that has excellent heat resistance and a crosslinked product of the composition.

Acrylic rubber composition and cross-linked product thereof

The present invention provides an acrylic rubber composition and its vulcanized product, having good vulcanization characteristics and an excellent balance between processability, mechanical properties of rubber and compression set. The acrylic rubber composition comprises a carboxyl group-containing acrylic rubber, a diazabicycloalkene compound, a polyamine compound, and a tertiary amine compound represented by the following formula (1): where each of R, Rand Ris independently a substituent having at least one saturated aliphatic hydrocarbon or unsaturated aliphatic hydrocarbon having a linear structure, a branched structure or a cyclic structure, or benzyl group.

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Itoigawa, Japan

Uichiro Yamagishi