High molecular weight, oil-soluble, mono- and polycarboxylic acid esters are posttreated with mono- or polycarboxylic acid acylating reagents to provide compositions useful as dispersants in lubricants and fuels. Esters of polyisobutenyl-substituted succinic anhydride and pentaerythritol posttreated with maleic anhydride exemplify the process and compositions of this invention.
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权利要求:
What is claimed is:1. A lubricating or fuel composition comprising a major amount of, respectively, a lubricating oil or a normally liquid fuel and a minor amount sufficient to improve the sludge-dispersing capabilities of said composition of an oil-soluble ester product produced by a process comprising contacting at a temperature of about 50.degree. C. up to just below the decomposition temperature (A) at least one oil-soluble ester of aliphatic mono- or polycarboxylic acid and a polyhydric alcohol characterized by the presence of unesterified free hydroxyl groups in the alcohol moiety where the carboxylic acid moiety of the ester is characterized by at least about 50 aliphatic carbon atoms exclusive of the carboxyl carbon atoms and the alcohol moiety contains up to about 40 aliphatic carbon atoms with (B) at least one acylating reactant selected from mono- or polycarboxylic acids having one to about 30 carbon atoms, anhydrides thereof, acyl halides thereof, or mixtures of two or more of these acylating agents, in an equivalent reaction of (A) to (B) of about 1:0.05 to about 1:5.2. A composition according to claim 1 where at last a portion of said oil-soluble ester (A) is characterized by the presence of unreacted hydroxyl groups in the alcoholic moiety as a result of preparing said oil-soluble ester (A) by reacting aliphatic mono- or polycarboxylic acid acylating agent and polyhydric alcohol in an equivalent ratio of acylating agent to polyhydric alcohol of about 1:1.05 to about 1:6.3. A composition according to claim 2 where said oil-soluble ester (A) is at least one ester of a mono- or polycarboxylic acid or anhydride with at least one polyhydric alcohol having three to 10 aliphatic carbon atoms and at least three hydroxyl groups wherein the mono- or polycarboxylic acid or anhydride is one derived from the reaction of a poly (1-monoolefin) or chlorinated poly (1-monoolefin) having average molecular weight of about 700 to about 5,000 with an .alpha., .beta.-ethylenically unsaturated mono- or polycarboxylic acid or anhydride and wherein said contacting occurs at a temperature of about 100.degree. C. to about 250.degree. C.4. A composition according to claim 3 where said acylating reactant (B) is an aliphatic acylating reactant containing one to six carbon atoms.5. A composition according to claim 4 wherein said polyhydric alcohol is a polyhydric alkanol and said acylating reactant (B) is selected from maleic anhydride, succinic maleic acid, succinic anhydride, succininc acid, or fumaric acid.6. A composition according to claim 5 wherein said polyhydric alkanol is selected from the class consisting of glycerol, erythritol, pentaerythritol, mannitol, and sorbitol.7. A composition according to claim 2 wherein said equivalent ratio of acylating agent to polyhydric alcohol is about 1:1.1 to 1:4.8. A composition according to claim 7 where said oil-soluble ester (A) is at least one ester of a substituted succinic acid wherein the substituent is a substantially saturated aliphatic substituent containing at least about 50 aliphatic carbon atoms.9. A lubricating composition according to claim 8 where said oil-soluble ester (A) is a diester of a polyolefin-substituted succinic acid wherein the polyolefin substituent has a molecular weight of about 700 to about 5,000 and not more than about 5 percent of the carbon-to-carbon covalent linkages in this substituent are unsaturated linkages.10. A composition according to claim 9 wherein the acylating reactant (B) is an aliphatic acylating agent containing one to six carbon atoms.11. A composition according to claim 10 wherein said oil-soluble ester (A) is an ester of a polyhydric aliphatic alcohol of up to 10 carbon atoms and characterized by the presence of at least three hydroxyl groups.12. A composition according to claim 11 wherein the polyhydric alcohol is a polyhydric alkanol, the acylating reactant is selected from the class consisting of maleic anhydride, maleic acid, succinic anhydride, succinic acid, and fumaric acid.13. A composition according to claim 12 wherein said oil-soluble ester (A) is a diester of polyisobutenyl-substituted succinic acid and a polyhydric alkanol selected from the class consisting of glycerol, erythritol, pentaerythritol, mannitol, and sorbitol.