Abstract: A pressure-sensitive adhesive contains an acrylic triblock copolymer (I) at not less than 60% by mass based on the total mass of all solids contained in the pressure-sensitive adhesive, the acrylic triblock copolymer being represented by the formula A1-B-A2 wherein: A1 and A2 are each independently an alkyl methacrylate polymer block having Tg of not less than 100° C. and B is an acryl acrylate polymer block having Tg of not more than ?20° C.; the content of the polymer block B is 50 to 95% by mass; Mw is in the range of 50,000 to 300,000; and the molecular weight distribution is in the range of 1.0 to 1.5. Preferably, the acrylic triblock copolymer (I) is a combination of an acrylic triblock copolymer (Ia) having Mw of 50,000 to less than 100,000 and an acrylic triblock copolymer (Ib) having Mw of 100,000 to 300,000, in a mass ratio (Ia):(Ib) of 45:55 to 75:25.

Abstract: A continuous production process, for producing an (meth)acrylic ester (co)polymer comprises the step of continuously feeding an organoaluminum compound-containing polymerization initiator solution and an (meth)acrylic ester into a reactor to continuously obtain a living polymer-containing polymer reaction liquid. The {[molar quantity of methacrylic ester or acrylic ester]/([molar quantity of organoaluminum compound]?[molar quantity of polymerization initiator])} fed into the reactor is regulated to be 15 to 80, and the content of the (meth)acrylic ester in the total feed amount of a polymerization initiator solution and an (meth)acrylic ester fed into the reactor is regulated to not more than 5% by mass.

Abstract: A lubricating oil additive containing at least one acrylic block copolymer having a weight-average molecular weight of 10,000 to 1,000,000 and a molecular weight distribution [ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn), i.e., Mw/Mn ratio] of 1.5 or below; and lubricating oil compositions containing the additive. The lubricating oil additive exhibits a thickening effect higher than those of conventional acrylic lubricating oil additives and can improve the viscosity index of lubricating oil even when added in a small amount. Further, the additive can also improve the low-temperature characteristics, flow characteristics, and shear stability. The lubricating oil compositions enable energy saving and can lengthen the lifetime of lubricating oil and reduce the load on the global environment.

Abstract: Pressure-sensitive adhesives for optical films exhibit high cohesion, excellent re-workability, adhesion properties, heat resistance and durability without chemical crosslinking. A pressure-sensitive adhesive contains an acrylic triblock copolymer (I) at not less than 60% by mass based on the total mass of all solids contained in the pressure-sensitive adhesive, the acrylic triblock copolymer being represented by the formula A1-B-A2 wherein: A1 and A2 are each independently an alkyl methacrylate polymer block having Tg of not less than 100° C. and B is an acryl acrylate polymer block having Tg of not more than ?20° C.; the content of the polymer block B is 50 to 95% by mass; Mw is in the range of 50,000 to 300,000; and the molecular weight distribution is in the range of 1.0 to 1.5.

Abstract: A continuous production process, which can allow polymerization to proceed at a milder polymerization temperature and a higher polymerization speed as compared with the conventional method while maintaining a high level of living properties and can produce an (meth)acrylic ester (co)polymer having a narrow molecular weight distribution in a high yield with good productivity. The continuous production process for producing an (meth)acrylic ester (co)polymer comprises the step of continuously feeding an organoaluminum compound-containing polymerization initiator solution and an (meth)acrylic ester into a reactor to continuously obtain a living polymer-containing polymer reaction liquid.

Abstract: The present invention provides an adhesive composition containing a block copolymer, wherein the block copolymer has a polymer block (A) which is principally composed of a ?-methyl styrene unit, and a polymer block (B) which is principally composed of a conjugated diene unit and of which at least part of carbon-carbon unsaturated double bonds may be hydrogenated, and having a good holding power at high temperatures.

Abstract: A lubricating oil additive containing at least one acrylic block copolymer having a weight-average molecular weight of 10,000 to 1,000,000 and a molecular weight distribution [ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn), i.e., Mw/Mn ratio] of 1.5 or below; and lubricating oil compositions containing the additive. The lubricating oil additive exhibits a thickening effect higher than those of conventional acrylic lubricating oil additives and can improve the viscosity index of lubricating oil even when added in a small amount. Further, the additive can also improve the low-temperature characteristics, flow characteristics, and shear stability. The lubricating oil compositions enable energy saving and can lengthen the lifetime of lubricating oil and reduce the load on the global environment.

Abstract: A block copolymer is obtained by anionic polymerization, includes two or more polymer blocks A miscible with each other, and at least one (meth)acrylic ester polymer block B immiscible with the polymer blocks A, has a ratio [Mn(Amax)/Mn(Amin)] of 2 or more, wherein the ratio [Mn(Amax)/Mn(Amin)] is the ratio of the largest number average molecular weight [Mn(Amax)] to the smallest number average molecular weight [Mn(Amin)] among the polymer blocks A, has at least one block bonding including polymer block Amax-polymer block B-polymer block Amin, and has a total content of the polymer blocks A ranging from 20 wt % to 45 wt % based on the total mass of the block copolymer. This invention provides block copolymers having two or more polymer blocks A miscible with each other and at least one (meth)acrylic ester polymer block B immiscible with the polymer blocks A and exhibiting satisfactory flexibility, melt fluidity, moldability, coatability, mechanical properties, and other properties.

Abstract: A process for the preparation of an acrylic acid ester polymer, includes carrying out polymerization of an acrylic acid ester or block copolymerization of an acrylic acid ester and another (meth)acrylic monomer in the presence of an organolithium compound and an organoaluminum compound represented by the following formula (I): AlR1R2R3??(I) wherein R1 represents an alkyl group having at least 3 carbon atoms, an alkoxy group having at least 3 carbon atoms or an aryloxy group, R2 and R3 each independently represent an aryloxy group or may be coupled together to form an arylenedioxy group. The process makes it possible to heighten the reaction rate and living properties upon polymerization and heighten the block formation efficiency upon block copolymerization.

Abstract: The present invention provides an adhesive composition containing a block copolymer, wherein the block copolymer has a polymer block (A) which is principally composed of a ?-methyl styrene unit, and a polymer block (B) which is principally composed of a conjugated diene unit and of which at least part of carbon-carbon unsaturated double bonds may be hydrogenated, and having a good holding power at high temperatures.

Abstract: In anionic polymerization using an anionic polymerization initiator, a tertiary organoaluminum compound (A) having in the molecule thereof a chemical structure represented by a general formula: Al—O—Ar wherein Ar represents an aromatic ring, and at least one Lewis base (B) selected from the group consisting of an ether compound and a tertiary polyamine compound are caused to be present in the polymerization system. In this way, the polar monomer can be polymerized with a high polymerization initiation efficiency and a high living polymerization property and at a high polymerization rate even if the used polymerization initiator is suitable for industrial use and a relatively mild cooling condition or a temperature condition near room temperature is adopted as a polymerization temperature condition.

Abstract: The present invention provides an adhesive composition containing a block copolymer, wherein the block copolymer has a polymer block (A) which is principally composed of a &agr;-methyl styrene unit, and a polymer block (B) which is principally composed of a conjugated diene unit and of which at least part of carbon-carbon unsaturated double bonds may be hydrogenated, and having a good holding power at high temperatures.

Abstract: (1) A methacrylic ester or an acrylic ester is anionically polymerized, using a polymerization initiator compound comprising an addition reaction product of a conjugated diene compound and an organic alkali metal compound, in the presence of a tertiary organoaluminum compound having in the molecule thereof a chemical structure represented by a formula: Al—O—Ar wherein Ar represents an aromatic ring; or (2) a methacrylic ester or an acrylic ester is anionically polymerized, using a polymerization initiator compound comprising an addition reaction product of an organic alkali metal compound and a compound having a 1,1-diaryl-1-alkene structure, by adding the ester in the form of a mixture with the above-mentioned specific tertiary organoaluminum compound to the polymerization system.

Abstract: To provide a biocompatible material with a high level of safety at a low cost. The biocompatible material has a polymer synthesized from monomers by an anionic polymerization, wherein the polymer has a ratio (Mw/Mn) of a weight-average molecular weight (Mw) to a number-average molecular weight (Mn) in a range of 1.0 to 1.5, in which the weight-average molecular weight is 40,000 or more, and each of the monomers is represented by a following general formula (1): where R1 is a hydrogen atom or a methyl group; R2 is a C1-C4 alkylene group; and R3 is a C1-C4 alkyl group.

Abstract: A block copolymer is obtained by anionic polymerization, includes two or more polymer blocks A miscible with each other, and at least one (meth)acrylic ester polymer block B immiscible with the polymer blocks A, has a ratio [Mn(Amax)/Mn(Amin)] of 2 or more, wherein the ratio [Mn(Amax)/Mn(Amin)] is the ratio of the largest number average molecular weight [Mn(Amax)] to the smallest number average molecular weight [Mn(Amin)] among the polymer blocks A, has at least one block bonding including polymer block Amax-polymer block B-polymer block Amin, and has a total content of the polymer blocks A ranging from 20 wt % to 45 wt % based on the total mass of the block copolymer.

Abstract: (1) A methacrylic ester or an acrylic ester is anionically polymerized, using a polymerization initiator compound comprising an addition reaction product of a conjugated diene compound and an organic alkali metal compound, in the presence of a tertiary organoaluminum compound having in the molecule thereof a chemical structure represented by a formula: Al—O—Ar wherein Ar represents an aromatic ring; or

Abstract: (1) A methacrylic ester or an acrylic ester is anionically polymerized, using a polymerization initiator compound comprising an addition reaction product of a conjugated diene compound and an organic alkali metal compound, in the presence of a tertiary organoaluminum compound having in the molecule thereof a chemical structure represented by a formula: Al—O—Ar wherein Ar represents an aromatic ring; or (2) a methacrylic ester or an acrylic ester is anionically polymerized, using a polymerization initiator compound comprising an addition reaction product of an organic alkali metal compound and a compound having a 1,1-diaryl-1-alkene structure, by adding the ester in the form of a mixture with the above-mentioned specific tertiary organoaluminum compound to the polymerization system.

Abstract: In anionic polymerization using an anionic polymerization initiator, a tertiary organoaluminum compound (A) having in the molecule thereof a chemical structure represented by a general formula: Al—O—Ar wherein Ar represents an aromatic ring, and at least one Lewis base (B) selected from the group consisting of an ether compound and a tertiary polyamine compound are caused to be present in the polymerization system. In this way, the polar monomer can be polymerized with a high polymerization initiation efficiency and a high living polymerization property and at a high polymerization rate even if the used polymerization initiator is suitable for industrial use and a relatively mild cooling condition or a temperature condition near room temperature is adopted as a polymerization temperature condition.

Abstract: In anionic polymerization using an anionic polymerization initiator, a tertiary organoaluminum compound (A) having in the molecule thereof a chemical structure represented by a general formula: Al—O—Ar wherein Ar represents an aromatic ring, and at least one Lewis base (B) selected from the group consisting of a tertiary polyamine compound, are caused to be present in the polymerization system. In this way, the polar monomer can be polymerized with a high polymerization initiation efficiency and a high living polymerization property and at a high polymerization rate even if the used polymerization initiator is suitable for industrial use, and a relatively mild cooling condition or a temperature condition near room temperature is adopted as a polymerization temperature condition.

Abstract: To provide a biocompatible material with a high level of safety at a low cost. The biocompatible material has a polymer synthesized from monomers by an anionic polymerization, wherein the polymer has a ratio (Mw/Mn) of a weight-average molecular weight (Mw) to a number-average molecular weight (Mn) in a range of 1.0 to 1.