Sanyo Chemical Industries, Ltd.

Shigekuni Nakada

Takayuki Tsuji

Yukiya Kobayashi

Hiroyuki Watanabe

Ayumu Sakaguchi

Katsuya Uchida

Hiroki Mori

Satoshi Matsumoto

Hiroki Yamashita

Kenyuu Yoshida

Motonao Kaku

Takenori Tatsumi

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).

Viscosity index improver, lubricant composition, and method for manufacturing lubricant composition

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/cm).

Viscosity index improver and lubricating oil composition

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.

Polymer polyol, method for producing the same, and method for producing polyurethane resin

A method for producing a fine-particle-dispersed polyol (I) is provided, the method including the steps (1) and (n&#x2212;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&#x2212;1) of polymerizing (b) in a fine-particle-dispersed polyol intermediate (B(n&#x2212;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 &#x3bc;m to 1.0 &#x3bc;m, and a concentration of (b) in the step (1) is 7 wt % to 40 wt %. Thus, a method for producing a fine-particle-dispersed polyol can be provided that contains polymer fine particles dispersed in a polyol having a small particle diameter, and that, when it is used for forming a polyurethane resin, allows the polyurethane resin to exhibit excellent resin properties.

Method for producing fine-particle-dispersed polyol, and method for producing polyurethane resin

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 &#x3bc;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.

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Kyoto, Japan

Shigekuni Nakada