Claims
- 1. A method of dispersing visible wax particles in a lubricating oil containing fractions of naphthenic or paraffinic crude oil at room temperature comprising adding to the oil from about 50 to about 2,500 parts per million of a composition comprisingA) an esterified styrene-maleic anhydride copolymer wherein the number of repeating units ranges from about 60 to about 400, and wherein said copolymer is a reaction product of a styrene-maleic anhydride copolymer having a molecular weight of from about 24,000 to about 60,000 and a mixture of C20-C28 linear alcohols containing about 49% C20 alcohols, about 29% C22 alcohols about 12% C24 alcohol, about 5% C26 alcohols and about 2% C28 alcohols by weight, and C22 alcohol wherein the alcohols are in a 3 to 1 ratio for C20-C28 linear alcohols to C22 alcohol; and B) an esterified alpha-olefin maleic anhydride copolymer wherein the number of repeating units ranges from about 20 to about 220, wherein the esterified alpha-olefin maleic anhydride copolymer is prepared by: (1) reacting maleic anhydride and a mixture of linear alpha-olefins of from about 10 to about 18 carbon atoms to form an alpha olefin-maleic anhydride copolymer having a molecular weight of from about 18,000 to about 40,000 and (2) reacting the alpha olefin-maleic anhydride copolymer with a mixture of C9-C18 alcohols containing about 47% C12-C16 alcohols, about 20% C9-C10 alcohols and about 33% C16-C18 alcohols by weight, wherein the ratio of the esterified styrene-maleic anhydride copolymer to the esterified alpha-olefin maleic anhydride copolymer is from about one to two to about two to one.
- 2. The method of claim 1 wherein the lubricating oil is a naphthenic lubricating oil having a viscosity between about 200 and about 850 SSU at 100° F.
- 3. The method of claim 1 wherein the ratio of the esterified styrene-maleic anhydride copolymer to the esterified alpha-olefin maleic anhydride copolymer is about two to one.
Parent Case Info
This application is a continuation-in-part of Ser. No. 08/017,426 entitled “Composition and Method for Lubricant Wax Dispersant and Pour Point Improver” by Kim B. Peyton and Sophia L. Wang filed Feb. 12, 1993, now abandoned, which is in turn a continuation-in-part of Ser. No. 07/566,615 filed Aug. 13, 1990, now abandoned.
US Referenced Citations (12)
Foreign Referenced Citations (2)
Number |
Date |
Country |
1800712 |
May 1969 |
DE |
1963761 |
Jul 1970 |
DE |
Non-Patent Literature Citations (2)
Entry |
Literature Search Report No. 2638, S. Boyle, Sep. 17, 1988 “Styrene-maleic anhydride copolymer esters used as lubricant wax dispersants”, 1967-Aug. 1988 (Nalco Chemical Company). |
Literature Search Report No. 2639, S. Boyle, Sep. 17, 1988, “Styrene-maleic anhydride copolymer esters used as naphthenic oil pour point depressants”, 1967, Aug. 1988 (Nalco Chemical Company). |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
08/017426 |
Feb 1993 |
US |
Child |
08/340998 |
|
US |
Parent |
07/566615 |
Aug 1990 |
US |
Child |
08/017426 |
|
US |