Additives to improve the flow of heavy fuels and crude oils

Abstract

Long-chain, amide-containing esters of carboxylic acid-containing polymers as flow improvers in hydrocarbon oils are disclosed and claimed. These fluidity improvers are useful in hydrocarbon oils, such as crude oils, residual fuel oils and middle distillate fuels. The novel materials of the present invention are also useful as pour point depressants in various hydrocarbon oils, for example, in crude oils, residual fuel oils and middle distillate fuels.

We claim: 
     
       1. An improved hydrocarbon oil having a lower pour point and improved flow characteristics comprising (a) a major amount of the oil and (b) a minor amount in the range of about 0.005% to about 1.0% of a composition comprising an N-acylaminoethyl ester of a carboxylic acid-containing polymer having the general formula: ##STR9## where R is an alkyl or alkene group having about 11 to 29 carbon atoms, .[.and.].0 where R 1  is H or an alkyl group having 1 to 4 carbon atoms.Iadd., and where the polymer backbone is derived from an olefin substituted or unsubstituted or from a copolymer of an olefin substituted or unsubstituted and at least one of an acid, an acid anhydride, and an ester.Iaddend. . 
     
     
       2. Composition according to claim 1 wherein the oil is selected from the group consisting of crude oils, middle distillate fuels and residual fuels, and wherein (b) is present in an amount of about 0.005% to about 1.0% by weight. 
     
     
       3. Composition according to claim 2 wherein (b) is a C 12  -C 30  amide-ester of an ethylene/acrylic acid copolymer, said copolymer having a molecular weight in the range of about 500 to 100,000. 
     
     
       4. Composition according to claim 2 wherein (b) is a C 14  -C 22  amide-ester of an ethylene/acrylic acid copolymer, said copolymer having a molecular weight in the range of about 500 to 100,000. 
     
     
       5. Composition according to claim 2 wherein (b) is a C 12  -C 30  amide-ester of .[.cetyl-eicosyl acrylate/acrylic acid copolymer, said copolymer.]. .Iadd.oxidized polyethylene, said polyethylene .Iaddend.having a molecular weight in the range of about 500 to 100,000. 
     
     
       6. Composition according to claim 2 wherein (b) is a C 12  -C 30  amide-ester of .[.cetyl-eicosyl methacrylate/acrylic acid.]. .Iadd.octadecene/maleic anhydride .Iaddend.copolymer, said copolymer having a molecular weight in the range of about 500 to 100,000. 
     
     
       7. Composition according to claim 2 wherein (b) is a C 12  -C 30  amide-ester of methyl acrylate/maleic anhydride/isobutylene copolymer, said copolymer having a molecular weight in the range of about 500 to about 100,000. 
     
     
       8. Composition according to claim 2 wherein (b) is a C 12  -C 30  amide-ester of ethylene/acrylic acid/vinyl acetate terpolymer, said terpolymer having a molecular weight in the range of about 500 to about 100,000.