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

Patent metadata

Field	Value
Publication number	US-2018320102-A1
Application number	US-201615770041-A
Country	US
Kind code	A1
Filing date	Nov 7, 2016
Priority date	Nov 9, 2015
Publication date	Nov 8, 2018
Grant date	—

Abstract

A viscosity modifier for lubricating oils according to the present invention contains a resin (α), wherein the resin (α) satisfies specific requirements, and contains a grafted olefin polymer [R1] which is composed of a main chain and a side chain(s) and which satisfies the following requirements (i) and (ii). (i) The main chain is composed of a copolymer of ethylene and at least one α-olefin selected from α-olefins having from 3 to 12 carbon atoms, and contains the structural units derived from ethylene within the range of from 74 to 86 mol %. (ii) The side chain(s) is/are composed of a copolymer of ethylene and at least one α-olefin selected from α-olefins having from 3 to 12 carbon atoms, and contain(s) the structural units derived from ethylene within the range of from 30 to 65 mol %.

First claim

1 . A viscosity modifier for lubricating oils, comprising a resin (α),
wherein the resin (α) satisfies the following requirements (I) and (II), and comprises a grafted olefin polymer [R1] which is composed of a main chain and a side chain(s) and which satisfies the following requirements (i) and (ii):
(i) the main chain is composed of a copolymer of ethylene and at least one α-olefin selected from α-olefins having from 3 to 12 carbon atoms, and comprises structural units derived from the ethylene within the range of from 74 to 86 mol %; and
(ii) the side chain(s) is/are composed of a copolymer of ethylene and at least one α-olefin selected from α-olefins having from 3 to 12 carbon atoms, and comprise(s) the structural units derived from ethylene within the range of from 30 to 65 mol %;
(I) the melting point (Tm) as measured by differential scanning calorimetry (DSC) is within the range of from −20 to 100° C.; and
(II) the intrinsic viscosity [η] as measured in decalin at 135° C. is within the range of from 0.5 to 2.5 dl/g.

2 . The viscosity modifier for lubricating oils according to claim 1 , wherein the resin (α) further satisfies the following requirement (III):
(III) the ratio of the structural units derived from ethylene with respect to the total structural units is within the range of from 40 to 85 mol %, and the ratio of structural units derived from the α-olefin having from 3 to 12 carbon atoms with respect to the total structural units is within the range of from 15 to 60 mol % (with the proviso that the total amount of the structural units derived from ethylene and the structural units derived from the α-olefin having from 3 to 12 carbon atoms is taken as 100 mol %).

3 . The viscosity modifier for lubricating oils according to claim 1 , wherein the resin (α) is composed of the structural units derived from ethylene and structural units derived from propylene.

4 . The viscosity modifier for lubricating oils according to claim 1 , wherein the resin (α) has a density as measured by the density-gradient tube method in accordance with JIS K7112 within the range of from 850 to 880 kg/m 3 .

5 . The viscosity modifier for lubricating oils according to claim 1 , wherein the grafted olefin polymer [R1] further satisfies the following requirement (iii):
(iii) the main chain is derived from an ethylene/α-olefin copolymer having a weight average molecular weight within the range of from 70,000 to 400,000.

6 . The viscosity modifier for lubricating oils according to claim 1 , wherein the grafted olefin polymer [R1] further satisfies the following requirement (iv):
(iv) the side chain(s) is/are derived from an ethylene/α-olefin copolymer having a weight average molecular weight (Mw) within the range of from 1,000 to 70,000.

7 . A method for producing the viscosity modifier for lubricating oils according to claim 1 , the method comprising the following steps (A) and (B):
(A) copolymerizing ethylene and at least one α-olefin selected from α-olefins having from 3 to 12 carbon atoms in the presence of an olefin polymerization catalyst comprising a transition metal compound [A] of a transition metal of Group 4 in the periodic table, to produce an ethylene/α-olefin copolymer having terminal unsaturation; and (B) copolymerizing the ethylene/α-olefin copolymer having terminal unsaturation produced in the step (A), ethylene, and at least one α-olefin selected from α-olefins having from 3 to 12 carbon atoms in the presence of an olefin polymerization catalyst comprising a transition metal compound [B] of a transition metal of Group 4 in the periodic table, to produce the resin (α).

8 . The method for producing the viscosity modifier for lubricating oils, according to claim 7 , wherein the ethylene/α-olefin copolymer having terminal unsaturation produced in the step (A) comprises the structural units derived from ethylene within the range of from 30 to 65 mol %, and has a weight average molecular weight (Mw) as measured by gel permeation chromatography within the range of from 1,000 to 70,000.

9 . The method for producing the viscosity modifier for lubricating oils, according to claim 7 , wherein the transition metal compound [A] of a transition metal of Group 4 in the periodic table is a transition metal compound of a transition metal of Group 4 in the periodic table, the compound comprising a ligand having a dimethylsilylbisindenyl skeleton.

10 . The method for producing the viscosity modifier for lubricating oils, according to claim 7 , wherein the transition metal compound [B] of a transition metal of Group 4 in the periodic table is a bridged metallocene compound represented by the following general formula [B]:

(wherein in the formula [B],
R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , R 9 and R 12 each independently represents a hydrogen atom, a hydrocarbon group, a silicon-containing group, or a hetero atom-containing group other than silicon-containing groups, and two mutually adjacent groups of the groups represented by R 1 to R 4 are optionally bound together to form a ring;
R 6 and R 11 are the same atom or the same group selected from hydrogen atom, hydrocarbon groups, silicon-containing groups, and hetero atom-containing groups other than the silicon-containing groups; R 7 and R 10 are the same atom or the same group selected from hydrogen atom, hydrocarbon groups, silicon-containing groups, and hetero atom-containing groups other than the silicon-containing groups; R 6 and R 7 are optionally bound together to form a ring; and R 10 and R 11 are optionally bound together to form a ring; with the proviso that all of R 6 , R 7 , R 10 and R 11 are not hydrogen atoms;
R 13 and R 14 each independently represents an aryl group;
Y 1 represents a carbon atom or a silicon atom;
M 1 represents a zirconium atom or a hafnium atom;
Q represents a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a neutral conjugated or non-conjugated diene having from 4 to 10 carbon atoms, an anionic ligand, or a neutral ligand capable of being coordinated with a lone pair of electrons;
j represents an integer of from 1 to 4; and
in cases where j is an integer of two or more, a plurality of Qs may be the same as or different from each other).

11 . The method for producing the viscosity modifier for lubricating oils, according to claim 7 , wherein the step (B) is a solution polymerization process carried out at a polymerization temperature of 90° C. or more.

12 . An additive composition for lubricating oils, comprising from 1 to 50 parts by mass of the viscosity modifier for lubricating oils according to claim 1 , and from 50 to 99 parts by mass of an oil (B) (with the proviso that the total amount of the viscosity modifier for lubricating oils and the oil (B) is taken as 100 parts by mass).

13 . A lubricating oil composition comprising from 0.1 to 5 parts by mass of the viscosity modifier for lubricating oils according to claim 1 , and from 95 to 99.9 parts by mass of a lubricating oil base (BB) (with the proviso that the total amount of the viscosity modifier for lubricating oils and the lubricating oil base (BB) is taken as 100 parts by mass).

14 . The lubricating oil composition according to claim 13 , further comprising from 0.05 to 5% by mass of a pour point depressant (C) in 100% by mass of the lubricating oil composition.

15 . The lubricating oil composition according to claim 13 , wherein the lubricating oil base (BB)

Assignees

• Mitsui Chemicals Inc

Inventors

• Hayakawa Akio
• Yanagimoto Yasushi
• Yamamoto Atsushi
• Nakamura Tatsuya
• Matsugi Tomoaki
• Okada Keiji

Classifications

• C08F4/65908

  in combination with an ionising compound other than alumoxane, e.g. (C6F5)4B-X+ · CPC title

• C10M143/02 Primary

  Polyethylene · CPC title

• C08F290/042

  Polymers of hydrocarbons as defined in group C08F10/00 · CPC title

• C10N2030/02

  Pour-point; Viscosity index · CPC title

• C10M2209/084

  Acrylate; Methacrylate · CPC title