Lubricant for two-cycle engines

Abstract

A two-cycle engine lubricant comprising from about 10% to about 30% low ash detergent inhibitor; from about 10% to about 45% bio-based ester selected from the group consisting of castor oil, a synthetic polyol-based ester and mixtures thereof; from about 14% to about 37% polyalphaolefin; from about 7% to about 18% synthetic ester; from 2% to about 10% surfactant; and from about 2% to about 5% pour point depressant; by weight of the lubricant. Optionally, the subject two-cycle lubricant can also comprise up to about 20 weight percent solvent, such as Stoddard solvent, to improve miscibility of the lubricant with gasoline fuel. The subject lubricant can be pre-packaged with gasoline for use with small engines not equipped for direct lubricant injection. A method for making the subject lubricant composition so as to resist subsequent separation of the components into layers is also disclosed.

What is claimed:  
     
         1 . A two-cycle engine lubricant comprising from about 10% to about 30% low ash detergent inhibitor; from about 10% to about 45% bio-based ester selected from castor oil, a synthetic polyol-based ester, and mixtures thereof; from about 14% to about 37% polyalphaolefin; from about 7% to about 18% synthetic ester; from 2% to about 10% surfactant; and from about 2% to about 5% pour point depressant, by weight of the lubricant.  
     
     
         2 . The lubricant of  claim 1 , further comprising up to about 20 vol. % of a compatible solvent.  
     
     
         3 . The lubricant of  claim 2 , comprising about 10 vol. % solvent.  
     
     
         4 . The lubricant of  claim 2  wherein the lubricant viscosity is not less than about 6.5 cSt at 100° C.  
     
     
         5 . The lubricant of  claim 2  wherein the solvent is Stoddard Solvent.  
     
     
         6 . The lubricant of  claim 1 , comprising from about 10 wt. % to about 25 wt. % low ash detergent inhibitor.  
     
     
         7 . The lubricant of  claim 6 , comprising about 20 wt. % low ash detergent inhibitor.  
     
     
         8 . The lubricant of  claim 1  wherein the detergent inhibitor is ashless.  
     
     
         9 . The lubricant of  claim 1 , comprising from about 15 wt. % to about 40 wt. % of a bio-based ester selected from castor oil, synthetic polyol-based ester, and mixtures thereof.  
     
     
         10 . The lubricant of  claim 9 , comprising from about 20 wt. % to about 40 wt. % castor oil.  
     
     
         11 . The lubricant of  claim 9 , comprising from about 20 wt. % to about 40 wt. % synthetic polyol-based ester.  
     
     
         12 . The lubricant of  claim 9 , comprising a mixture of about 20 wt. % castor oil and about 20 wt. % synthetic polyol-based ester.  
     
     
         13 . The lubricant of  claim 9 , further comprising up to about 20 vol. % solvent.  
     
     
         14 . The lubricant of  claim 13  comprising about 10 vol. % solvent.  
     
     
         15 . The lubricant of  claim 13  wherein in the solvent is Stoddard Solvent.  
     
     
         16 . The lubricant of  claim 1  wherein the polyalphaolefin is a synthetic oil comprising hydrogenated trimer and homopolymer of 1-decene.  
     
     
         17 . The lubricant of  claim 9  wherein the polyalphaolefin is a synthetic oil comprising hydrogenated trimer and homopolymer of 1-decene.  
     
     
         18 . The lubricant of  claim 1  comprising about 25 wt. % polyalphaolefin.  
     
     
         19 . The lubricant of  claim 1  wherein the polyalphaolefin has a viscosity ranging between about 2 and about 6 cSt at 100° C.  
     
     
         20 . The lubricant of  claim 19  wherein the polyalphaolefin has a viscosity ranging between about 2 cSt and about 4 cSt at 100° C.  
     
     
         21 . A biodegradable lubricant having the composition of  claim 20 .  
     
     
         22 . The lubricant of  claim 1  wherein the synthetic ester comprises 2-ethylhexyl 2-ethylhexanonate.  
     
     
         23 . The lubricant of  claim 1  wherein the pour point depressant comprises diethylhexyl adipate.  
     
     
         24 . The lubricant of  claim 9  wherein the pour point depressant comprises diethylhexyl adipate.  
     
     
         25 . The lubricant of  claim 1  wherein the surfactant is a polyolefin derivative that comprises a highly branched succinic acid that can be neutralized with potassium hydroxide and amine.  
     
     
         26 . The lubricant of  claim 1  in combination with gasoline.  
     
     
         27 . The combination of  claim 26  wherein the lubricant and gasoline are premixed and packaged.  
     
     
         28 . The combination of  claim 27  wherein the gasoline and lubricant are packaged in a ratio of about 50 to 1 by volume.  
     
     
         29 . The combination of  claim 27  wherein the gasoline and lubricant are packaged in a ratio of about 100 to 1 by volume.  
     
     
         30 . The combination of  claim 27  wherein the lubricant is diluted with a solvent before premixing with gasoline.  
     
     
         31 . The combination of  claim 26  wherein the lubricant is biodegradable.  
     
     
         32 . A method for making a two-cycle engine lubricant comprising the steps of: 
 preparing a first premixture by combining a first set of components comprising from about 10 wt. % to about 30 wt. % of a low ash detergent inhibitor and from about 14 wt. % to about 37 wt. % polyalphaolefin, by weight of the lubricant, and mixing the combined first set of components under high shear conditions for about 10 to about 15 minutes;    preparing a second premixture by combining a second set of components comprising from about 10 wt. % to about 45 wt. % bio-based ester selected from the group consisting of castor oil, a synthetic polyol-based ester and mixtures thereof, from about 7 wt. % to about 18 wt. % synthetic ester, from 2 wt. % to about 10 wt. % surfactant and from about 2 wt. % to about 5 wt. % pour point depressant, by weight of the lubricant, and mixing the combined second set of components under high shear conditions for a period ranging from about 20 to about 40 minutes; and    thereafter adding the first premixture to the second premixture and mixing under high shear conditions for a period ranging from about 30 to about 35 minutes to form the lubricant composition.    
     
     
         33 . The method of  claim 32  wherein mixing takes place at a temperature ranging between about 120° and about 125° F.  
     
     
         34 . The method of  claim 32  wherein the first and second premixtures are further combined with up to about 20 vol. % solvent.  
     
     
         35 . The method of  claim 34  wherein the first and second premixtures are combined with about 10 vol. % solvent.  
     
     
         36 . The method of  claim 34  wherein the solvent is Stoddard Solvent.  
     
     
         37 . The method of  claim 34  wherein the viscosity of the resultant lubricant is not reduced below about 6.5 cSt at 100° C.  
     
     
         38 . The method of  claim 32  wherein the lubricant is then cooled to ambient temperature.  
     
     
         39 . The method of  claim 38  wherein the cooled lubricant is then packaged.  
     
     
         40 . The method of  claim 34  wherein the cooled lubricant is mixed with gasoline and then packaged.  
     
     
         41 . The method of  claim 40  wherein the gasoline and cooled lubricant are mixed in a ratio of about 50 to 1 by volume.  
     
     
         42 . The method of  claim 40  wherein the gasoline and cooled lubricant are mixed in a ratio of about 100 to 1 by volume.