Abstract: An acrylic rubber, including: 50 to 99.9% by weight of a bond unit derived from at least one (meth) acrylic acid ester selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylic acid alkoxyalkyl ester; 0.1 to 20% by weight of a bond unit derived from a monomer containing a reactive group; and 0 to 30% by weight of a bond unit derived from other monomer, wherein the acrylic rubber contains a phenolic anti-aging agent represented by a general formula (1), (R1 represents an isopropyl group or a t-butyl group, and R2 represents an alkyl group having 1 to 12 carbon atoms), and the weight average molecular weight (Mw) of the acrylic rubber is in the range of 100,000 to 5,000,000.

Abstract: Acrylic rubber bale excellent in storage stability and processability, a method for producing the same, a rubber mixture obtained by mixing the acrylic rubber bale, and a cross-linked product of the rubber mixture are provided. The acrylic rubber bale includes an acrylic rubber having a reactive group and a weight average molecular weight (Mw) of 100,000 to 5,000,000, wherein an amount of gel insoluble in methyl ethyl ketone is 50% by weight or less, and a specific gravity is 0.8 or more.

Abstract: An acrylic rubber bale excellent in storage stability and processability, a method for producing the same, a rubber mixture obtained by mixing the acrylic rubber bale, and a rubber cross-linked product of the rubber mixture are provided. The acrylic rubber bale according to the present invention includes an acrylic rubber having a reactive group and a weight average molecular weight (Mw) of 100,000 to 5,000,000, wherein an amount of gel insoluble in methyl ethyl ketone is 50% by weight or less, and pH is 6 or less.

Abstract: An acrylic rubber excellent in water resistance and a method for producing the same are provided. An acrylic rubber composed of: 70 to 99.9 wt % of a bonding unit derived from (meth) acrylic acid ester; 0.1 to 10 wt % of a bonding unit derived from a cross-linkable monomer; and if necessary, 0 to 20 wt % of a bonding unit derived from another monomer, wherein the ash content is 0.5 wt % or less, the total amount of magnesium and phosphorus in the ash is 30 wt % or more, a ratio of the magnesium to the phosphorus ([Mg]/[P]) by weight is 0.4 to 2.5, and Mooney viscosity (ML1+4, 100° C.) of the rubber is 10 to 150 is particularly excellent in water resistance, and a rubber cross-linked product using the same is also excellent in physical properties.

Abstract: Acrylic rubber bale excellent in storage stability and processability, a method for producing the same, a rubber mixture obtained by mixing the acrylic rubber bale, and a cross-linked product of the rubber mixture are provided. The acrylic rubber bale includes an acrylic rubber having a reactive group and a weight average molecular weight (Mw) of 100,000 to 5,000,000, wherein an amount of gel insoluble in methyl ethyl ketone is 60% by weight or less, and a specific gravity is 0.8 or more.

Abstract: An acrylic rubber bale excellent in strength properties and processability, a method for producing the same, a rubber mixture containing the acrylic rubber bale, a method for producing the same, and a rubber cross-linked product of the same. The acrylic rubber bale includes an acrylic rubber mainly containing a (meth) acrylic acid ester having a weight average molecular weight (Mw) of 1,000,000 to 5,000,000, and a ratio (Mz/Mw) of a Z-average molecular weight (Mz) and a weight average molecular weight (Mw) is 1.3 or more, wherein an amount of gel insoluble in methyl ethyl ketone is 50% by weight or less.

Abstract: Acrylic rubber bale having remarkably improved storage stability and water resistance without deteriorating cross-linking properties, a method of production, a rubber mixture obtained by mixing the acrylic rubber bale, a method of production, and a rubber cross-linked product obtained by cross-linking the same is provided. The acrylic rubber bale includes an acrylic rubber, and the acrylic rubber is mainly composed of (meth) acrylic acid ester, and has a weight average molecular weight of 100,000 to 5,000,000, and has a ratio of a Z-average molecular weight and a weight average molecular weight of 1.3 or more, where an ash content is 0.6% by weight or less, and the ash contains a periodic table group 2 metal and phosphorus, and a phosphorus content is 10% by weight or more, and the ratio of the periodic table group 2 metal to phosphorus is in the range of 0.6 to 2 molar ratio.

Abstract: An acrylic rubber sheet excellent in storage stability and processability, a method for producing the same, an acrylic rubber bale obtained by laminating the sheets, a mixture obtained by mixing the acrylic rubber sheet and the acrylic rubber bale, a method for producing the mixture and a rubber cross-linking product obtained by cross-linking the mixture. The acrylic rubber sheet comprises, an acrylic rubber mainly composed of a (meth) acrylic acid ester and having a weight average molecular weight (Mw) of 100,000 to 5,000,000 and a ratio (Mz/Mw) of a Z-average molecular weight (Mz) and a weight average molecular weight (Mw) is 1.3 or more, and the acrylic rubber sheet contains a phenolic anti-aging agent, and a gel amount is 50 wt % or less. The acrylic rubber sheet is extremely excellent in storage stability and processability and the sheet can be easily produced by the claimed method.

Abstract: A nitrile group-containing copolymer rubber comprising 10 to 40 wt % of ?,?-ethylenically unsaturated nitrile unit (a), 10 to 60 wt % of ?,?-ethylenically unsaturated carboxylic acid ester unit (b), and 20 to 70 wt % in total of conjugated diene unit (c) and saturated conjugated diene unit (d), wherein a content ratio “x” of a conjugated diene unit (c) based on the total content of said conjugated diene unit (c) and said saturated conjugated diene unit (d) is 0.08 or smaller, and “x·A” defined as a product of said ratio “x” and a content ratio “A” (%) of said ?,?-ethylenically unsaturated nitrile unit (a) is 1.5 or smaller. According to the present invention, a nitrile group-containing copolymer rubber capable to provide a rubber vulcanizate highly balanced in mechanical strength, heat aging resistance, oil resistance, cold resistance and ozone resistance, and a vulcanizable rubber composition using the rubber can be provided.

Abstract: A process for hydrogenating a conjugated diene polymer wherein a conjugated diene polymer is hydrogenated in the presence of a catalyst comprising a platinum group metal or its compound, and a basic compound. More specifically, (1) hydrogenation is conducted in a reaction system prepared by incorporating the catalyst and the basic compound in a solution or latex of the conjugated diene polymer; (2) hydrogenation is conducted in a reaction system prepared by incorporating a catalyst system comprising a combination of the catalyst with the basic compound, in a solution or latex of the conjugated diene polymer; or (3) hydrogenation is conducted in a reaction system prepared by incorporating the catalyst in a solution of a composition comprising the conjugated diene polymer and the basic compound. Thus, a hydrogenated conjugated diene polymer can be efficiently and industrially advantageously produced using a small amount of a catalyst.

Abstract: A nitrile group-containing copolymer rubber comprising 10 to 40 wt % of ?,?-ethylenically unsaturated nitrile unit (a), 10 to 60 wt % of ?,?-ethylenically unsaturated carboxylic acid ester unit (b), and 20 to 70 wt % in total of conjugated diene unit (c) and saturated conjugated diene unit (d), wherein a content ratio “x” of a conjugated diene unit (c) based on the total content of said conjugated diene unit (c) and said saturated conjugated diene unit (d) is 0.08 or smaller, and “x·A” defined as a product of said ratio “x” and a content ratio “A” (%) of said ?,?-ethylenically unsaturated nitrile unit (a) is 1.5 or smaller. According to the present invention, a nitrile group-containing copolymer rubber capable to provide a rubber vulcanizate highly balanced in mechanical strength, heat aging resistance, oil resistance, cold resistance and ozone resistance, and a vulcanizable rubber composition using the rubber can be provided.

Abstract: A process for hydrogenating a conjugated diene polymer wherein a conjugated diene polymer is hydrogenated in the presence of a catalyst comprising a platinum group metal or its compound, and a basic compound. More specifically, (1) hydrogenation is conducted in a reaction system prepared by incorporating the catalyst and the basic compound in a solution or latex of the conjugated diene polymer; (2) hydrogenation is conducted in a reaction system prepared by incorporating a catalyst system comprising a combination of the catalyst with the basic compound, in a solution or latex of the conjugated diene polymer; or (3) hydrogenation is conducted in a reaction system prepared by incorporating the catalyst in a solution of a composition comprising the conjugated diene polymer and the basic compound. Thus, a hydrogenated conjugated diene polymer can be efficiently and industrially advantageously produced using a small amount of a catalyst.

Abstract: A latex of a cyano-bearing copolymer rubber which contains units derived from an ?,?-ethylenically unsaturated nitrile monomer in an amount of 10 to 30% by mass and has an iodine number of 250 or below, a Mooney viscosity (ML1+4, 100° C.) of 10 to 120, and a difference (?Tg) between extrapolated glass transition initiation temperature (Tig) and extrapolated glass transition ending temperature (Teg) of 15° C. or below as determined by differential scanning calorimetry; and fluid treatments for bonding and adhesive compositions, containing the latex. The adhesive compositions are excellent in heat resistance, oil resistance, and adhesion to vulcanized rubbers, and exhibit tackiness.

Abstract: A process for hydrogenating a conjugated diene polymer wherein a conjugated diene polymer is hydrogenated in the presence of a catalyst comprising a platinum group metal or its compound, and a basic compound. More specifically, (1) hydrogenation is conducted in a reaction system prepared by incorporating the catalyst and the basic compound in a solution or latex of the conjugated diene polymer; (2) hydrogenation is conducted in a reaction system prepared by incorporating a catalyst system comprising a combination of the catalyst with the basic compound, in a solution or latex of the conjugated diene polymer; or (3) hydrogenation is conducted in a reaction system prepared by incorporating the catalyst in a solution of a composition comprising the conjugated diene polymer and the basic compound. Thus, a hydrogenated conjugated diene polymer can be efficiently and industrially advantageously produced using a small amount of a catalyst.

Abstract: A crosslinkable rubber composition comprising (a) 100 weight parts of a nitrile group-containing highly saturated copolymer rubber containing units of an ethlenically unsaturated dicarboxylic acid monoalkyl ester monomer, (b) 0.5 to 10 parts by weight of a polyamine crosslinking agent, and (c) 0.5 to 10 parts by weight of a basic crosslinking accelerator. This rubber composition gives a crosslinked nitrile group-containing highly saturated copolymer rubber article having excellent heat resistance, flex fatigue resistance and elongation, and reduced permanent set.

Abstract: There are provided an acrylate polymer elastomer containing a particular acrylic ester unit as a constitutive component, and a vulcanizable composition comprising the elastomer and a vulcanizing agent.The acrylate polymer elastomer is obtained by copolymerizing(a) 45 to 89.9 wt. % of a monomer represented a by the formula ##STR1## wherein R.sup.1 represents an alkyl group having 1 to 8 carbon atoms, and/or a monomer represented by the formula ##STR2## wherein R.sup.2 represents an alkylene group having 1 to 8 carbon atoms and R.sup.3 represents an alkyl group having 1 to 8 carbon atoms,(b) 10 to 35 wt. % of a monomer represented by the formula t,0012wherein R.sup.4 represents a hydrogen atom or a methyl group, R.sup.5 represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, and n represents an integer of 1 to 5,(c) 0.1 to 10 wt. % of crosslinkable monomer, and(d) 0 to 30 wt. % of a monoethylenic unsaturated monomer copolymerizable with the above(a) , (b) and (c) components.

Abstract: An additive for improving the dispersibility of a particulate substance in an organic medium, a thermoplastic polymer, or a thermosetting resin, is at least one compound having a ##STR1## bond in the molecule, including, for example, compounds having an oxazolinium ion in the molecule. The preferred additive compounds are oligomeric or polymeric.

Abstract: There are provided an acrylic copolymer elastomer containing an acrylic acid polyalkylene glycol ester as a constituent, and a vulcanizable composition comprising said elastomer and a vulcanizing agent, which composition gives a vulcanizate excellent in cold resistance, heat resistance and oil resistance. The acrylic copolymer elastomer is obtained by copolymerizing(a) 45 to 89.9% by weight of a monomer represented by the formula ##STR1## wherein R.sup.1 denotes an alkyl group having 1 to 8 carbon atoms, and/or a monomer represented by the formula ##STR2## wherein R.sup.2 denotes an alkylene group having 1 to 8 carbon atoms, and R.sup.3 denotes an alkyl group having 1 to 8 carbon atoms,(b) 10 to 45% by weight of a monomer represented by the formula ##STR3## wherein R.sup.4 denotes a hydrogen atom or a methyl group, R.sup.5 denotes a hydrocarbon group having 1 to 8 carbon atoms, m is an integer of 2 to 10, and n is an integer of 2 to 3,(c) 0.

Abstract: There are provided an acrylic copolymer elastomer containing an acrylic acid polyalkylene glycol ester as a constituent, and a vulcanizable composition comprising said elastomer and a vulcanizing agent, which composition gives a vulcanizate excellent in cold resistance, heat resistance and oil resistance. The acrylic copolymer elastomer is obtained by copolymerizing(a) 45 to 89.9% by weight of a monomer represented by the formula ##STR1## wherein R.sup.1 denotes an alkyl group having 1 to 8 carbon atoms, and/or a monomer represented by the formula ##STR2## wherein R.sup.2 denotes an alkylene group having 1 to 8 carbon atoms, and R.sup.3 denotes an alkyl group having 1 to 8 carbon atoms,(b) 10 to 45% by weight of a monomer represented by the formula ##STR3## wherein R.sup.4 denotes a hydrogen atom or a methyl group, R.sup.5 denotes a hydrocarbon group having 1 to 8 carbon atoms, m is an integer of 2 to 10, and n is an integer of 2 to 3,(c) 0.

Abstract: An improved diene type polymer rubber is prepared by reacting a diene type polymer rubber, to which an alkali metal and/or an alkaline earth metal has been added, with a compound represented by the formula: ##STR1## wherein M is oxygen or sulfur, R.sub.1 and R.sub.4 are a substituent having no hydrogen on the .alpha.-carbon atom, R.sub.2 and R.sub.3 are hydrogen or a hydrocarbon group, m is an integer of at least 2, and n is an integer of 2 to 4. The diene type polymer rubber is characterized in that, even after storage for a long time, the Mooney viscosity rises only to a very slight extent, and the rebound, wet skid resistance and other physical properties of the cured product thereof are not substantially changed.