Mitsui Chemicals, Inc.

The Lubrizol Corporation

Akihiro Matsuda

Satoshi Ikeda

Keiji Okada

Ryousuke Kaneshige

Junichi Mohri

Masahiro Enna

Yoshiki Shimokawatoko

Masaaki Kawasaki

Shigenobu Ikenaga

Shigekazu Matsui

Yasuhiro Kitahara

Naomi Urakawa

Makoto Nakano

Ryosuke Aburaki

Toshiyuki Shimazaki

Hiroshi Terao

Koji Takeda

Nobuo Murase

The propylene-based polymer composition includes a specific amount of a propylene-based polymer (A) having a syndiotactic pentad fraction (rrrr fraction) of 85% or more and containing 90 to 100 mol % of a structural unit derived from propylene; a specific amount of a propylene-based copolymer (B) containing 40 to 89 mol % of a structural unit derived from propylene and 11 to 60 mol % of a structural unit derived from an &#x3b1;-olefin and satisfying a specific equation of intrinsic viscosity [&#x3b7;] and MFR; and specific amount(s) of at least one polymer of an olefin-based thermoplastic elastomer (C), a styrene-based elastomer (D), a propylene/ethylene/&#x3b1;-olefin copolymer (E) and an isotactic propylene-based polymer (F), and optionally an ethylene/vinyl acetate copolymer (G) and/or an ethylene-based polymer (H).

Propylene-based polymer composition and uses thereof

A lubricating oil composition for a power transmission system, which is excellent in both of low-temperature viscosity property and shear stability, is provided. The viscosity modifier of a lubricating oil for a power transmission system according to the present invention comprises an ethylene/&#x3b1;-olefin copolymer (B) having the properties: (B1) an ethylene content in the range of 70 to 85% by mol, (B2) an intrinsic viscosity [&#x3b7;] in the range of 0.2 to 1.0 dl/g, (B3) Mw/Mn not more than 2.4, and (B4) a melting point, as measured by DSC, not higher than 60&#xb0; C., or no melting point observed.

Viscosity modifier of lubricating oil for power transmission system and lubricating oil composition for power transmission system

The present invention is a polyolefin polymer containing vinyl groups at both ends thereof, and a composition and a molded product containing the polymer, wherein the polymer contains a constitutional unit derived from at least one selected from the group consisting of ethylene (a), an &#x3b1;-olefin (b) having 3 to 20 carbon atoms, and a cyclic olefin (c), and The polymer of the present invention may be molded by a LIM molding, an injection molding, a transfer molding, a compression molding, and the like, and is excellent in acid resistance, gas permeation resistance, hydrolysis resistance, and dynamic fatigue resistance. From the polymer, a thermoplastic resin composition and a crosslinkable resin composition, and a crosslinked composition having excellent mechanical characteristics are obtained.

Polyolefin polymer containing vinyl groups at both ends and composition thereof

Copolymers when used as lubricating oil viscosity modifiers enable lubricating oils to show excellent low-temperature properties. Processes for producing the copolymers are disclosed. Lubricating oil viscosity modifiers and lubricating oil compositions contain the copolymers. A copolymer includes structural units derived from ethylene and structural units derived from a C3-20 &#x3b1;-olefin and satisfies the following requirements (1) to (8): (1) the melting point (Tm) according to DSC is in the range of 0 to 60&#xb0; C.; (2) the melting point (Tm) and the density D (g/cm) satisfy the equation: Tm&#x2267;1073&#xd7;D&#x2212;893; (3) Mw/Mn according to GPC is from 1.6 to 5.0; (4) the half-value width (&#x394;T) of a melting peak measured by DSC is not more than 90&#xb0; C.; (5) the half-value width (&#x394;T) and the melting point (Tm) satisfy the equation: &#x394;T&#x2266;&#x2212;0.71&#xd7;Tm+101.4; (6) the heat of fusion (&#x394;H) as measured by DSC is not more than 60 J/g; (7) the crystallization temperature (Tc) measured by DSC is not more than 70&#xb0; C.; (8) the heat of fusion (&#x394;H), the crystallization temperature (Tc), each measured by DSC and the crystallization temperature measured by a CRYSTAF method (T) satisfy the equation: Tc&#x2212;T&#x2267;0.028&#xd7;&#x394;H+25.3.

Copolymer, production process thereof, lubricating oil viscosity modifier, and lubricating oil composition

A viscosity modifier for lubricating oils or an additive composition for lubricating oils, which is excellent in oil-thickening properties and can provide lubricating oil compositions excellent in low-temperature characteristics and handleability at low temperatures; and lubricating oil compositions excellent in low-temperature characteristics and handleability at low temperatures. The viscosity modifier comprises an ethylene/&#x3b1;-olefin copolymer (B) which comprises (i) a structural unit derived from ethylene, (ii) a structural unit derived from an &#x3b1;-olefin having 3 to 19 carbon atoms, and (iii) a structural unit derived from a higher &#x3b1;-olefin having 4 to 20 carbon atoms whose carbon number is by one or more larger than that of the &#x3b1;-olefin having the unit (ii) which has the following properties of (1) and (2): (1) the contents of units (i), (ii) and (iii) are 25-49 mol %, 15-55 mol %, and 9-40 mol % respectively (with the proviso that the total of the units (i), (ii), and (iii) is 100 mol %) and (2) the intrinsic viscosity [&#x3b7;] is 0.5 to 5.0 dl/g.

Viscosity modifier for lubricating oils, additive composition for lubricating oils, and lubricating oil compositions

A copolymer containing a constituent unit derived from ethylene and a constituent unit derived from an &#x3b1;-olefin having 3 to 20 carbon atoms and satisfying the following requirements (1) to (5): (1) the copolymer has a melting point (Tm) of &#x2212;20&#xb0; C. to 100&#xb0; C.; (2) the melting point (Tm) and the density D (g/cm) satisfy the following expression Tm&#x2267;1073&#xd7;D&#x2212;893 (1); (3) the copolymer has a molecular weight distribution (Mw/Mn) measured by GPC of 1.6 to 5.0; (4) the copolymer has a half-width (&#x394;Thalf) of a melting peak measured by DSC of 90&#xb0; C. or less; and (5) the half-width (&#x394;Thalf) and the melting point (Tm) satisfy the relationship shown by the following expression&#x394;Thalf&#x2266;&#x2212;0.71&#xd7;Tm+101.4&#x2003;&#x2003;(2).

Copolymer, lubricating oil viscosity modifier, and lubricating oil composition

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Ichihara, Japan

Akihiro Matsuda