Oil spill microemulsion dispersants

Claim 1

A method for dispersing an oil spill on sea water which method comprises applying to the oil spill surface an effective amount of: (i) a blend of one or more hydrophilic and one or more lipophilic surfactants so balanced that they will form microemulsions with the sea water and the oil to be dispersed, (ii) a solvent which is miscible with the oil to be dispersed and in which the blend of surfactants is substantially soluble, and (iii) from 0 to about 10 wt.% water, wherein the blend of surfactants is such that it lowers the interfacial tension between the oil to be dispersed and the sea water to less than about 250 mdynes/cm when the blend is used at a treat rate of less than about 1 to 100 by weight, based on the oil to be dispersed.

Claim 2

A method for dispersing an oil spill on sea water which method comprises applying to the oil spill surface an effective amount of: (i) a blend of one or more hydrophilic and one or more lipophilic surfactants so balanced that they will form microemulsions with the sea water and the oil to be dispersed, (ii) a solvent which is miscible with the oil to be dispersed and in which the blend of surfactants is substantially soluble, and (iii) from 0 to about 10 wt.% water, wherein the blend of surfactants is such that it lowers the interfacial tension between the oil to be dispersed and the sea water to less than about 250 mdynes/cm when the blend is used at a treat rate of less than about 1 to 100 by weight, based on the oil to be dispersed.

Claim 4

The method of claims 2 wherein a cosolvent is present and the cosolvent is selected from the group consisting of one or more alkylene glycol monoalkyl ethers and C 2 to C 5 alcohols.

Claim 10

A method for dispersing an oil spill on sea water which method comprises applying to the oil spill surface an effective amount of: (i) a blend of one or more hydrophilic and one or more lipophilic surfactants so balanced that they will form microemulsions with the sea water and the oil to be dispersed wherein the blend is comprised of two or more surfactants selected from one or both of: (a) an alkali metal, ammonium, alkyl ammonium, alkanol ammonium or ethoxylated alkyl or alkanol ammonium salt of an alkyl or alkylaryl sulfonic acid of the generic formula: R--SO.sub.3 H wherein R is an alkyl or alkyl benzene group containing 8 to 30 carbon atoms in the alkyl chain and the benzene ring may be additional substituted with one or two alkyl groups containing 1-3 carbon atoms each, and (b) an ethoxylated surfactant of the generic formula: R.sub.1 X(CH.sub.2 CH.sub.2 O).sub.n Y wherein R 1 is an alkyl or mono- or di-alkyl aryl group containing 8 to 30 carbon atoms, X is --O--, --S--, ##STR4## or --SO 2 NH-- Y is --H, --SO 3 - M + or --(PO 3 H) - M + wherein M + is an inorganic on ammonium cation including alkyl substituted ammonium cations; R 2 is an alkyl group containing 1 to 20 carbon atoms or a polyethoxy ether group containing from 1 to 30 (CH 2 CH 2 O) groups; R 3 is H or an alkyl group containing 1 to 3 carbon atoms; R 4 is a poly hydroxy group derived from glycerol, glycols, sorbitol, or various sugars; and n is an integer from 1 to 30; (ii) a solvent which is miscible with the oil to be dispersed and in which the blend of surfactants is substantially soluble, and (iii) from 0 to about 10 wt.% water, wherein the blend of surfactants is such that it lowers the interfacial tension between the oil to be dispersed and the sea water to less than about 250 mdynes/cm when the blend is used at a treat rate of less than about 1 to 100 by weight, based on the oil to be dispersed.

Claim 11

A method for dispersing an oil spill on sea water which method comprises applying to the oil spill surface an effective amount of: (i) a blend of one or more hydrophilic and one or more lipophilic surfactants so balanced that they will form microemulsions with the sea water and the oil to be dispersed wherein the blend is comprised of two or more surfactants selected from one or both of: (a) an alkali metal, ammonium, alkyl ammonium, alkanol ammonium or ethoxylated alkyl or alkanol ammonium salt of an alkyl or alkylaryl sulfonic acid of the generic formula: R--SO.sub.3 H wherein R is an alkyl or alkyl benzene group containing 8 to 30 carbon atoms in the alkyl chain and the benzene ring may be additional substituted with one or two alkyl groups containing 1-3 carbon atoms each, and (b) an ethoxylated surfactant of the generic formula: R.sub.1 X(CH.sub.2 CH.sub.2 O).sub.n Y wherein R 1 is an alkyl or mono- or di-alkyl aryl group containing 8 to 30 carbon atoms, X is --O--, --S--, ##STR4## or --SO 2 NH-- Y is --H, --SO 3 - M + or --(PO 3 H) - M + wherein M + is an inorganic on ammonium cation including alkyl substituted ammonium cations; R 2 is an alkyl group containing 1 to 20 carbon atoms or a polyethoxy ether group containing from 1 to 30 (CH 2 CH 2 O) groups; R 3 is H or an alkyl group containing 1 to 3 carbon atoms; R 4 is a poly hydroxy group derived from glycerol, glycols, sorbitol, or various sugars; and n is an integer from 1 to 30; (ii) a solvent which is miscible with the oil to be dispersed and in which the blend of surfactants is substantially soluble, and (iii) from 0 to about 10 wt.% water, wherein the blend of surfactants is such that it lowers the interfacial tension between the oil to be dispersed and the sea water to less than about 250 mdynes/cm when the blend is used at a treat rate of less than about 1 to 100 by weight, based on the oil to be dispersed.