Viscosity index improver and lube oil containing the same

• US 6,746,993 B2
• Filed: 08/07/2002
• Issued: 06/08/2004
• Est. Priority Date: 04/06/2001
• Status: Active Grant

• Current Assignee: Sanyo Chemical Industries Limited
• Original Assignee: Sanyo Chemical Industries Limited
• Inventors: Ota, Yoshihisa, Yuki, Tsuyoshi
• Primary Examiner(s): McAvoy, Ellen M.
• Application Number:
  US10/212,784
• Publication Number:
  US 20030104955A1
• Time in Patent Office: 671 Days
• Field of Search: 508/469, 508/321, 508/325, 508/320, 508/319
• US Class Current: 508/469
• CPC Class Codes: C10M 145/14 Acrylate; Methacrylate
• CPC Class Codes: C10M 149/04 containing monomers having an unsaturated radical bound to an amino group
• CPC Class Codes: C10M 149/10 containing monomers having an unsaturated radical bound to a nitrogen-containing hetero ring
• CPC Class Codes: C10M 171/00 Lubricating compositions characterised by purely physical criteria, e.g. containing as base-material, thickener or additive, ingredients which are characterised exclusively by their numerically specified physical properties, i.e. containing ingredients which are physically well-defined but for which the chemical nature is either unspecified or only very vaguely indicated chemically defined ingredients C10M101/00 - C10M169/00; petroleum fractions C10M101/02, C10M121/02, C10M159/04
• CPC Class Codes: C10M 2209/04 containing monomers having an unsaturated radical bound to an alcohol or ester thereof; bound to an aldehyde, ketonic, ether, ketal or acetal radical
• CPC Class Codes: C10M 2209/06 containing monomers having an unsaturated radical bound to an acyloxy radical of saturated carboxylic or carbonic acid
• CPC Class Codes: C10M 2209/062 Vinyl esters of saturated carboxylic or carbonic acids, e.g. vinyl acetate
• CPC Class Codes: C10M 2209/084 Acrylate; Methacrylate
• CPC Class Codes: C10M 2217/02 Macromolecular compounds obtained from nitrogen containing monomers by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: C10M 2217/022 containing monomers having an unsaturated radical bound to an amino group
• CPC Class Codes: C10M 2217/023 the amino group containing an ester bond
• CPC Class Codes: C10M 2217/028 containing monomers having an unsaturated radical bound to a nitrogen-containing hetero ring
• CPC Class Codes: C10N 2020/01 Physico-chemical properties
• CPC Class Codes: C10N 2020/04 Molecular weight; Molecular weight distribution
• CPC Class Codes: C10N 2020/071 Branched chain compounds
• CPC Class Codes: C10N 2030/02 Pour-point; Viscosity index
• CPC Class Codes: C10N 2040/02 Bearings
• CPC Class Codes: C10N 2040/04 Oil-bath; Gear-boxes; Automatic transmissions; Traction drives
• CPC Class Codes: C10N 2040/042 for automatic transmissions
• CPC Class Codes: C10N 2040/046 for traction drives
• CPC Class Codes: C10N 2040/08 : Hydraulic fluids, e.g. brake-fluids
• CPC Class Codes: C10N 2040/25 : Internal-combustion engines
• CPC Class Codes: C10N 2060/06 : by epoxydes or oxyalkylation reactions
• CPC Class Codes: C10N 2070/00 : Specific manufacturing methods for lubricant compositions
• CPC Class Codes: C10N 2070/02 : Concentrating of additives

Abstract

Viscosity index improvers, are disclosed, comprising the following polymer (A1) or (A0).

Polymer (A1) has a solubility parameter of 8.6-9.4, a crystallizing initiation temperature of −15° C. or less and a steric hindrance factor (F) of 0-13, and comprises units of at least one of (a) C_1-40alkyl group-containing (meth)acrylates, (b) alkyl alkenyl ethers, (c) alkenyl carboxylates and (d) nitrogen-containing unsaturated monomers.

Polymer (A0) comprises units of a branched C_20-40alkyl group-containing (meth)acrylate (a0) capable of providing a homopolymer having a Tc of 5° C. or less and units of another alkyl (meth)acrylate.

Monomers, 2-decyl-tetradecyl methacrylate and 2-decyl-tetradecyl acrylate, are also described, suitable for producing polymers for viscosity index improvers.

Claims

1. A viscosity index improver, which comprises a polymer (A1) having a solubility parameter of 8.6-9.4, a crystallizing initiation temperature of −

15°

C. or less, and a steric hindrance factor (F) of 0-13, said factor F being defined by the following equation;

9. A viscosity improver concentrate, which comprises 10-90% by weight of said improver of claim 1 and 10-90% by weight of a diluent.

10. A viscosity improver concentrate, which comprises 10-90% by weight of said improver of claim 2 and 10-90% by weight of a diluent.

11. A lube oil composition, which comprises a major amount of a base oil and 0.5-30% by weight of said improver of claim 1.

12. The composition of claim 11, wherein the base oil has a kinematic viscosity of 1-15 mm²/s at 100°

C. and a viscosity index of at least 80.

2. A viscosity index improver, which comprises a polymer (A0) having a weight-average molecular weight of 5,000-2,000,000, comprising 5-95% by weight of units of at least one monomer (a0) and 5-95% by weight of units of at least one alkyl acrylate or methacrylate other than said monomer (a0):

said monomer (a0) being capable of providing a homopolymer having a crystallizing initiation temperature of 5°

C. or less and represented by the general formula;

wherein R⁰ is hydrogen atom or methyl group, R is a branched alkyl group containing 20-40 carbon atoms, n is 0 or an integer of 1-20 giving 0-10 on average, A is an alkylene group containing 2-4 carbon atoms, plural A'"'"'s in case of n being at least 2 are the same or different, and the polyoxyalkylene moiety (AO)_n in case of the plural A'"'"'s being different comprises random-wise or block-wise distributed oxyalkylene groups;

wherein said branched alkyl group is represented by the general formula;

wherein R′ and

R″

are the same or different straight-chain alkyl groups containing 8-18 carbon atoms.

3. The improver of claim 2, wherein said polymer (A0) has a solubility parameter of 8.6-9.4, a crystallizing initiation temperature of −

15°

C. or less, and a steric hindrance factor F of 0-13, said factor being defined by the following equation;

4. The improver of claim 2, wherein said polymer (A0) has a steric hindrance factor F of 0-10.

5. The improver of claim 2, wherein said polymer (A0) comprises 5-90% by weight of units of said monomer (a0), and 10-60% by weight of units of an alkyl acrylate or methacrylate (a2) containing 1-4 carbon atoms in the alkyl group, with or without 0-85% by weight of units of at least one selected from the group consisting of an alkyl acrylate or methacrylate (a3) containing 8-15 carbon atoms in the alkyl group, a branched alkyl acrylate or methacrylate (a12) containing 16-19 carbon atoms in the alkyl group, a straight-chain alkyl acrylate or methacrylate (a4) containing 16-18 carbon atoms in the alkyl group and a straight-chain alkyl acrylate or methacrylate (a5) containing 20-40 carbon atoms in the alkyl group.

6. The improver of claim 2, wherein said polymer (A0) comprises 10-45% by weight of units of 2-decyl-tetradecyl methacrylate, 20-45% by weight of units of methyl methacrylate, and 10-60% by weight of units of a straight-chain alkyl acrylate or methacrylate containing 10-18 carbon atoms in the alkyl group.

7. The improver of claim 2, wherein said polymer (A0) further comprises 0.1-10% by weight of units of a nitrogen-containing unsaturated monomer (d).

8. The improver of claim 7, wherein said monomer (d) is at least one selected from the group consisting of dimethyl-aminoethyl methacrylate, diethylaminoethyl methacrylate, morpholinoethyl methacrylate, and corresponding acrylates.

13. A lube oil composition, which comprises a major amount of a base oil and 0.5-30% by weight of said improver of claim 2.

14. The composition of claim 13, wherein the base oil has a kinematic viscosity of 1-15 mm²/s at 100°

C. and a viscosity index of at least 80.

15. A compound of 2-decyl-tetradecyl methacrylate.

16. A compound of 2-decyl-tetradecyl acrylate.

17. A polymer having a weight-average molecular weight of 5,000-2,000,000, comprising units of a compound selected from the group consisting of a compound of 2-decyl-tetradecyl methacrylate and a compound of 2-decyl-tetradecyl acrylate.

18. The polymer of claim 17, which comprises 5-95% by weight of units of the compound of 2-decyl-tetradecyl methacrylate, and 5-95% by weight of units of at least one monomer selecting from the group consisting of:

another alkyl methacrylate or an alkyl acrylate; and

alkyl alkenyl ether;

an alkenyl carboxylate; and

a nitrogen-containing unsaturated monomer.