Lubricant base stock blends

Patent metadata

Field	Value
Publication number	US-10731096-B2
Application number	US-201615750342-A
Country	US
Kind code	B2
Filing date	Jun 24, 2016
Priority date	Aug 21, 2015
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

Disclosed is a lubricant base stock blend comprising a PAO base stock and an alkylated aromatics (AA) base stock, wherein at least the longer portion of the pendant groups attached to the carbon backbones of the PAO molecules have comparable length to at least the longer portion of the side chain groups attached to the aromatic ring structure of the AA molecules. The comparable lengths of at least the longer portion of the pendant groups and the side chain groups lead to enhanced improvement in oxidation stability of the blend.

First claim

The invention claimed is:

1. A lubricant base stock blend comprising a PAO base stock made using a metallocene or supported chromium oxide catalyst and an alkylated aromatic base stock, wherein:
each molecule of the PAO base stock comprises a plurality of pendant groups, where at least 50% of the pendant groups on the PAO molecules are regio-regular;
the longest 5%, by mole, of the pendant groups of all of the molecules of the PAO base stock have an average pendant group length of Lpg(5%);
each molecule of the alkylated aromatic base stock comprises one or more side chain group;
the longest 5%, by mole, of all of the side chain groups of all of the molecules of the alkylated aromatic base stock have an average side chain group length of Lsc(5%); and
the difference between Lsc(5%) and Lpg(5%) is at most 8.0.

2. The lubricant base stock blend of claim 1 , wherein:
the longest 10%, 20%, 40%, 50%, and 100%, by mole, of the pendant groups of all of the molecules of the PAO base stock have an average pendant group length of Lpg(10%), Lpg(20%), Lpg(40%), Lpg(50%), and Lpg(100%), respectively;
the longest 10%, 20%, 40%, 50%, and 100%, by mole, of all of the side chain groups of all of the molecules of the alkylated aromatic base stock have an average side chain group length of Lsc(10%), Lsc(20%), Lsc(40%), Lsc(50%), and Lsc(100%), respectively; and at least one of the following conditions is met:
(i) |Lsc(10%)−Lpg(10%)|≤8.0;
(ii) |Lsc(20%)−Lpg(20%)|≤8.0;
(iii) |Lsc(40%)−Lpg(40%)|≤8.5;
(iv) |Lsc(50%)−Lpg(50%)|≤9.0; and
(v) |Lsc(100%)−Lpg(100%)|≤9.5.

3. The lubricant base stock blend of claim 1 , wherein at least one of the following conditions is met:
(i) Lsc(5%)≥Lpg(5%);
(ii) Lsc(10%)≥Lpg(10%);
(iii) Lsc(20%)≥Lpg(20%);
(iv) Lsc(40%)≥Lpg(40%);
(v) Lsc(50%)≥Lpg(50%); and
(vi) Lsc(100%)≥Lpg(100%).

4. The lubricant base stock blend of claim 1 , wherein at least one of the following conditions is met:
(i) 7.0≤Lpg(5%)≤12.0;
(ii) 7.0≤Lpg(10%)≤12.0;
(iii) 6.5≤Lpg(20%)≤11.0;
(iv) 6.0≤Lpg(40%)≤11.0;
(v) 5.5≤Lpg(50%)≤9.5; and
(vi) 5.0≤Lpg(100%)≤9.0.

5. The lubricant base stock blend of claim 1 , wherein at least 60% of the pendant groups on the PAO molecules in the PAO base stock have a pendent group length of at least 6.

6. The lubricant base stock blend of claim 4 , wherein at least 90% of the pendent groups on the PAO molecules in the PAO base stock have a pendant group length of at least 6.

7. The lubricant base stock blend of claim 1 , wherein at least 60% of the pendant groups on the PAO molecules have a pendent group length of at least 8.

8. The lubricant base stock blend of claim 6 , wherein at least 90% of the pendant groups on the PAO molecules have a pendent group length of at least 8.

9. The lubricant base stock blend of claim 1 , wherein the PAO base stock is produced from at least one alpha olefin comprising at least 8 carbon atoms in the presence of a metallocene catalyst.

10. The lubricant base stock blend of claim 1 , wherein the alkylated aromatic base stock comprises an alkylated naphthalene base stock.

11. The lubricant base stock blend of claim 1 , wherein at least one of the following conditions is met:
(i) Lsc(5%)≥10;
(ii) Lsc(10%)≥10;
(iii) Lsc(20%)≥10;
(iv) Lsc(40%)≥10;
(v) Lsc(50%)≥10; and
(vi) Lsc(100%)≥10.

12. The lubricant base stock blend of claim 1 , wherein at least one of the following conditions is met:
(i) 10.0≤Lsc(5%)≤20.0;
(ii) 10.0≤Lsc(10%)≤20.0;
(iii) 11.0≤Lsc(20%)≤19.0;
(iv) 12.0≤Lsc(40%)≤18.0;
(v) 13.0≤Lsc(50%)≤17.0; and
(vi) 14.0≤Lsc(100%)≤16.0.

13. The lubricant base stock blend of claim 1 , wherein the molar ratio of the PAO molecules to the alkylated aromatic base stock molecules is in a range from 1.0 to 10.0.

14. The lubricant base stock blend of claim 1 , wherein the weight ratio of the PAO base stock to the alkylated aromatic base stock is in a range from 0.40 to 0.90.

15. The lubricant base stock blend of claim 1 , further having an oxidation stability equal to aa*OS (ret), where OS(ref) is calculated pursuant to the following equation:

OS
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ref
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A
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A

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W
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+

W
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A
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+

OS
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Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Han Wenning W
• Nandapurkar Pramod J

Classifications

• C10M111/04 Primary

  at least one of them being a macromolecular organic compound · CPC title

• C10M2203/065

  used as base material · CPC title

• C10M2205/223

  used as base material · CPC title

• C10N2020/065

  Saturated Compounds · CPC title

• C10N2030/10

  Inhibition of oxidation, e.g. anti-oxidants · CPC title