Lubricant additive

• US 8,999,905 B2
• Filed: 10/25/2010
• Issued: 04/07/2015
• Est. Priority Date: 10/25/2010
• Status: Active Grant

• Current Assignee: Afton Chemical Corporation (Newmarket Corporation)
• Original Assignee: Afton Chemical Corporation (Newmarket Corporation)
• Inventors: Duggal, Akhilesh
• Primary Examiner(s): Oladapo, Taiwo
• Application Number:
  US12/925,565
• Publication Number:
  US 20120101017A1
• Time in Patent Office: 1,625 Days
• Field of Search: 508/591
• US Class Current: 508/591
• CPC Class Codes: C10M 143/10 containing aromatic monomer, e.g. styrene
• CPC Class Codes: C10M 143/12 containing conjugated diene
• CPC Class Codes: C10M 2205/04 containing aromatic monomers, e.g. styrene
• CPC Class Codes: C10M 2205/06 containing conjugated dienes
• CPC Class Codes: C10N 2020/01 Physico-chemical properties
• CPC Class Codes: C10N 2020/073 Star shaped polymers
• CPC Class Codes: C10N 2030/02 Pour-point; Viscosity index
• CPC Class Codes: C10N 2030/08 Resistance to extreme temperature
• CPC Class Codes: C10N 2040/25 Internal-combustion engines
• CPC Class Codes: C10N 2060/02 Reduction, e.g. hydrogenation
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A hydrogenated styrene butadiene star copolymer is incorporated in a lubricant additive package. The star copolymer can include about 3 to 25% and about 97 to 75% butadiene. The star copolymer may further be incorporated in a lubricant additive in the amount of about 12 wt % of the star copolymer as compared to the base oil.

Claims

1. A lubricant comprising a viscosity index improver wherein

a. the viscosity index improver comprises:

a hydrogenated styrene butadiene star copolymer, wherein the star copolymer is formed from styrene and butadiene monomers in a ratio of about 5 to 13% styrene to about 95 to 87% butadiene by weight, further wherein the star copolymer has greater than 50% of 1,2 polymerization of the butadiene monomer;

wherein the star copolymer core comprises divinylbenzene;

wherein the degree of hydrogenation of the star copolymer is at least 95%;

wherein the star copolymer has 3 or more arms and the molecular weight of each arm is more than 50,000;

a base oil; and

wherein the star copolymer is provided in an amount to be approximately 0.5 to 1.5 wt % of the lubricant; and

b. the lubricant has a mini-rotary viscometer (MRV TP-1) value improvement of at least 5000 cP over a lubricant containing a hydrogenated styrene isoprene star polymer or an olefin copolymer at generally equivalent kinematic viscosity at 100°

C.

2. The lubricant of claim 1, wherein the hydrogenated star polymer has about a 98% degree of hydrogenation.

3. The lubricant of claim 1, wherein the star copolymer has an average molecular weight (Mw) of at least about 700,000.

4. The lubricant of claim 1, wherein the ratio of styrene and butadiene monomers is about 10% styrene and 90% butadiene.

5. The lubricant of claim 1, wherein the star polymer comprises a hydrogenated, random styrene-butadiene copolymer.

6. The lubricant of claim 1, wherein the star polymer comprises a hydrogenated, styrene-butadiene block copolymer.

7. The lubricant of claim 1, wherein the base oil is a Group I base oil.

8. The lubricant of claim 1 having a mini-rotary viscometer value improvement of at least 8000 cP.

9. The lubricant of claim 1, wherein the lubricant comprises a Group I, Group II, Group III, or Group IV oil.

13. The lubricant of claim 1, wherein the star copolymer is provided in an amount to be approximately 0.3 to 2 wt % of the lubricant.

10. A method of improving the mini-rotary viscometer value (MRV TP-1) of a lubricant comprising the step of:

mixing a lubricant with a viscosity index improver,

wherein the viscosity index improver comprises;

a. a hydrogenerated styrene butadiene star copolymer, wherein the star copolymer is formed from styrene and butadiene monomers in a ratio of about 5 to 13% styrene to about 95 to 87% butadiene by weight, further wherein the star copolymer has greater than 50% of 1,2 polymerization of the butadiene monomer, and still further wherein the star copolymer core comprises divinylbenzene;

b. wherein the degree of hydrogenation of the star copolymer is at least 95% and further wherein the star copolymer has 3 or more arms and the molecular weight of each arm is more than 50,000;

c. a base oil; and

wherein the star copolymer is provided in an amount to be approximately 0.5 to 1.5 wt % of the lubricant.

11. The method of claim 10, further wherein the star copolymer comprises a hydrogenated, random styrene-butadiene copolymer.

12. The method of claim 10, further wherein the star copolymer comprises a hydrogenated, styrene-butadiene block copolymer.

14. The method of claim 10, wherein the star copolymer is provided in an amount to be approximately 0.3 to 2 wt % of the lubricant.

15. The method of claim 14, wherein the star copolymer is provided in an amount to be approximately 0.5 to 1.5 wt % of the lubricant.