Abstract: The present invention provides a viscosity index improver having an excellent viscosity index improving effect, a lubricant composition having excellent low-temperature viscosity in which the viscosity reduction due to long-term use is small, and a method for producing the lubricant composition. A viscosity index improver of the present invention contains a copolymer (A) containing, as monomer units, an alkyl (meth)acrylate (a) whose alkyl group contains 5 or more carbon atoms, and an alkyl (meth)acrylate (b) whose alkyl group contains 1 to 4 carbon atoms, wherein the alkyl group of the alkyl (meth)acrylate (a) whose alkyl group contains 5 or more carbon atoms has a molar-average carbon number (Q) of 29 or more, and the alkyl (meth)acrylate (b) whose alkyl group contains 1 to 4 carbon atoms is contained as a monomer unit in an amount of 38 to 75% by weight based on the weight of the copolymer (A).

Abstract: The present invention provides a viscosity index improver having an excellent viscosity index improving effect, a lubricant composition having excellent low-temperature viscosity in which the viscosity reduction due to long-term use is small, and a method for producing the lubricant composition. A viscosity index improver of the present invention contains a copolymer (A) containing, as monomer units, an alkyl (meth)acrylate (a) whose alkyl group contains 5 or more carbon atoms, and an alkyl (meth)acrylate (b) whose alkyl group contains 1 to 4 carbon atoms, wherein the alkyl group of the alkyl (meth)acrylate (a) whose alkyl group contains 5 or more carbon atoms has a molar-average carbon number (Q) of 29 or more, and the alkyl (meth)acrylate (b) whose alkyl group contains 1 to 4 carbon atoms is contained as a monomer unit in an amount of 38 to 75% by weight based on the weight of the copolymer (A).

Abstract: The present invention aims to provide a viscosity index improver excellent in shear stability and having a low HTHS viscosity and a high viscosity index. The viscosity index improver of the present invention contains a (co)polymer (A) containing a polyolefin-based monomer as an essential monomer unit, and a base oil, wherein the absolute value of difference in solubility parameter between the (co)polymer (A) and the base oil is 0.8 to 2.0 (cal/cm3)1/2.

Abstract: The present invention aims to provide a viscosity index improver excellent in shear stability and having a low HTHS viscosity and a high viscosity index. The viscosity index improver of the present invention contains a (co)polymer (A) containing a polyolefin-based monomer as an essential monomer unit, and a base oil, wherein the absolute value of difference in solubility parameter between the (co)polymer (A) and the base oil is 0.8 to 2.0 (cal/cm3)1/2.

Abstract: A polymer polyol (I) is provided that is formed of a polyol (A), polymer particles (B) obtained by polymerization of an ethylenically unsaturated compound (b), and an active-hydrogen-containing compound (d) having an aromatic ring and having a number-average molecular weight of 150 to 2,000, wherein a content of (d) is 1 to 20% on the basis of a weight of (B). The polymer polyol of the present invention contains polymer particles having sufficiently small particle diameters, has a low viscosity, and has excellent handleability. A polyurethane resin obtained by using the polymer polyol of the present invention has excellent mechanical strengths such as elongation at break.

Abstract: A method for producing a fine-particle-dispersed polyol (I) is provided, the method including the steps (1) and (n?1): the step (1) of polymerizing an ethylenically unsaturated monomer (b) in a polyol (a), in the presence of fine particles (P1) and a radical polymerization initiator (c), so as to obtain a fine-particle-dispersed polyol intermediate (B2); and the step (n?1) of polymerizing (b) in a fine-particle-dispersed polyol intermediate (B(n?1)), in the presence of (c), so as to obtain a fine-particle-dispersed polyol intermediate (Bn) or the fine-particle-dispersed polyol (I), where n represents an integer of 3 to 7, wherein (P1) have a volume-average particle diameter (R1) of 0.01 ?m to 1.0 ?m, and a concentration of (b) in the step (1) is 7 wt % to 40 wt %.

Abstract: A polymer polyol (I) is provided that is formed of a polyol (A), polymer particles (B) obtained by polymerization of an ethylenically unsaturated compound (b), and an active-hydrogen-containing compound (d) having an aromatic ring and having a number-average molecular weight of 150 to 2,000, wherein a content of (d) is 1 to 20% on the basis of a weight of (B). The polymer polyol of the present invention contains polymer particles having sufficiently small particle diameters, has a low viscosity, and has excellent handleability. A polyurethane resin obtained by using the polymer polyol of the present invention has excellent mechanical strengths such as elongation at break.

Abstract: A polymer polyol (I) is provided that is formed of a polyol (A), polymer particles (B) obtained by polymerization of an ethylenically unsaturated compound (b), and an active-hydrogen-containing compound (d) having an aromatic ring and having a number-average molecular weight of 150 to 2,000, wherein a content of (d) is 1 to 20% on the basis of a weight of (B). The polymer polyol of the present invention contains polymer particles having sufficiently small particle diameters, has a low viscosity, and has excellent handleability. A polyurethane resin obtained by using the polymer polyol of the present invention has excellent mechanical strengths such as elongation at break.

Abstract: A polyol composition comprising a polyol (a) and resin fine particles (b) dispersed in the polyol (a), and a method for producing the polyol composition are provided, wherein the resin fine particles (b) are particles such that an arithmetic standard deviation by volume of a particle size distribution of the particles, derived from respective values in 85 divisions of a range of 0.020 to 2000 ?m determined by a laser diffraction/scattering particle size distribution analyzer, is not more than 0.6. A resin fine particle-dispersed polyol composition that, even if the resin particles dispersed in the polyol have a small particle diameter, allows the production of a polyurethane resin having an excellent mechanical strength such as elongation at break, and a method for producing the same, are provided.

Abstract: A polyol composition comprising a polyol (a) and resin fine particles (b) dispersed in the polyol (a), and a method for producing the polyol composition are provided, wherein the resin fine particles (b) are particles such that an arithmetic standard deviation by volume of a particle size distribution of the particles, derived from respective values in 85 divisions of a range of 0.020 to 2000 ?m determined by a laser diffraction/scattering particle size distribution analyzer, is not more than 0.6. A resin fine particle-dispersed polyol composition that, even if the resin particles dispersed in the polyol have a small particle diameter, allows the production of a polyurethane resin having an excellent mechanical strength such as elongation at break, and a method for producing the same, are provided.

Abstract: A polyol composition comprising a polyol (a) and resin fine particles (b) dispersed in the polyol (a), and a method for producing the polyol composition are provided, wherein the resin fine particles (b) are particles such that an arithmetic standard deviation by volume of a particle size distribution of the particles, derived from respective values in 85 divisions of a range of 0.020 to 2000 ?m determined by a laser diffraction/scattering particle size distribution analyzer, is not more than 0.6. A resin fine particle-dispersed polyol composition that, even if the resin particles dispersed in the polyol have a small particle diameter, allows the production of a polyurethane resin having an excellent mechanical strength such as elongation at break, and a method for producing the same, are provided.

Abstract: A polyol composition comprising a polyol (a) and resin fine particles (b) dispersed in the polyol (a), and a method for producing the polyol composition are provided, wherein the resin fine particles (b) are particles such that an arithmetic standard deviation by volume of a particle size distribution of the particles, derived from respective values in 85 divisions of a range of 0.020 to 2000 ?m determined by a laser diffraction/scattering particle size distribution analyzer, is not more than 0.6. A resin fine particle-dispersed polyol composition that, even if the resin particles dispersed in the polyol have a small particle diameter, allows the production of a polyurethane resin having an excellent mechanical strength such as elongation at break, and a method for producing the same, are provided.

Abstract: Provided is a polymer polyol which has solved problems, such as clogging in a discharge head and insufficient hardness of a resulting polyurethane foam, occurring in the production of a polyurethane foam by mechanical foaming using a conventional polymer polyol as a raw material. The present invention is a polymer polyol (A) in which polymer fine particles (JR) having an ethylenically unsaturated compound (E) as a constituent unit are contained in a polyol (PL), wherein the (PL) comprises a polyol (a) with which the average number x of moles of ethylene oxide added per active hydrogen atom and the primary hydroxidation ratio y of terminal hydroxyl groups satisfy a specific relationship, and the volume average particle diameter (R) of the (JR) is from 0.1 to 1.5 ?m.

Abstract: A method for producing a fine-particle-dispersed polyol (I) is provided, the method including the steps (1) and (n?1): the step (1) of polymerizing an ethylenically unsaturated monomer (b) in a polyol (a), in the presence of fine particles (P1) and a radical polymerization initiator (c), so as to obtain a fine-particle-dispersed polyol intermediate (B2); and the step (n?1) of polymerizing (b) in a fine-particle-dispersed polyol intermediate (B(n?1)), in the presence of (c), so as to obtain a fine-particle-dispersed polyol intermediate (Bn) or the fine-particle-dispersed polyol (I), where n represents an integer of 3 to 7, wherein (P1) have a volume-average particle diameter (R1) of 0.01 ?m to 1.0 ?m, and a concentration of (b) in the step (1) is 7 wt % to 40 wt %.

Abstract: A polymer polyol (I) is provided that is formed of a polyol (A), polymer particles (B) obtained by polymerization of an ethylenically unsaturated compound (b), and an active-hydrogen-containing compound (d) having an aromatic ring and having a number-average molecular weight of 150 to 2,000, wherein a content of (d) is 1 to 20% on the basis of a weight of (B). The polymer polyol of the present invention contains polymer particles having sufficiently small particle diameters, has a low viscosity, and has excellent handleability. A polyurethane resin obtained by using the polymer polyol of the present invention has excellent mechanical strengths such as elongation at break.

Abstract: A polymer polyol (A) that comprises a polyol (PL) and polymer particles (JR) having an ethylenically unsaturated compound (E) as a constituent unit and contained in a polyol (PL) is provided, in which a ratio of acrylonitrile in (E) is 0 mol % to 67 mol %, and relationship between a viscosity of the polymer polyol and a content (PC) of the polymer particles satisfies a formula (1) below, and/or satisfies formulae (2) and (3) below: (N1)<0.9×(PC)?35??(1) (N2)<1.17×(PC)?46??(2) (N3)<1.37×(PC)?55??(3) where N1, N2, and N3 represent viscosities (Pa·s) of the polymer polyol at 25° C. at a shearing speeds of 1.0 (l/s), 0.1 (l/s), and 10.0 (l/s), respectively, measured by a rheometer; and PC represents a content (wt %) of (JR) in the polymer polyol.

Abstract: A polyol composition comprising a polyol (a) and resin fine particles (b) dispersed in the polyol (a), and a method for producing the polyol composition are provided, wherein the resin fine particles (b) are particles such that an arithmetic standard deviation by volume of a particle size distribution of the particles, derived from respective values in 85 divisions of a range of 0.020 to 2000 ?m determined by a laser diffraction/scattering particle size distribution analyzer, is not more than 0.6. A resin fine particle-dispersed polyol composition that, even if the resin particles dispersed in the polyol have a small particle diameter, allows the production of a polyurethane resin having an excellent mechanical strength such as elongation at break, and a method for producing the same, are provided.