Ashless Controlled Release Gels for Fuels

Abstract

The present invention relates to a control release gel for delivery of additives to fuels where the gel compositions are free of ash producing components, or are substantially free of ash producing components, such that the gel compositions of the present invention do not supply any ash to the fuel compositions with which they are used. Further, the invention provides for the use of such compositions in the operation of an internal combustion engine.

1 . A fuel additive gel composition comprising:
 a) a fuel soluble dispersant;   b) a fuel soluble acid selected from the group consisting of an acid formed from a polymer containing acidic groups in the backbone, a polyacidic compound, surfactants with acidic groups in the backbone, emulsifiers with acidic groups in the backbone and mixtures thereof; and   c) optionally at least one additional fuel additive;   wherein the gel composition is substantially free of ash producing components, and wherein the gel composition will release over time one or more of its components into a fuel composition with which it comes into contact.   
     
     
         2 . The fuel additive gel composition of  claim 1  wherein the fuel additive gel is at least 50% soluble in the fuel in which it is used, on a weight basis. 
     
     
         3 . The fuel additive gel compositions of  claim 1  wherein the fuel additive gel composition contains completely ashless components and wherein the weight ratio of the dispersant to the acid is about 0.01:1 to about 100:1; and wherein the gel has a tan delta value of ≦1. 
     
     
         4 . The composition of  claim 1  wherein the dispersant is present in a range from about 0.001 wt % to about 99.5 wt %, preferably 0.01% to 50% and more preferably 0.05% to 25%; and wherein the acid is present in a range from about 0.01 wt % to about 99.5 wt %, preferably 0.1% to 75% and more preferably 1% to 50%; and wherein the optional additional additive is present in a range from about 0 wt % to about 95 wt %, preferably 30% to 95% and more preferably 40% to 95% of the total weight of the gel. 
     
     
         5 . The composition of  claim 1  wherein the dispersant component comprises one or more dispersants selected from the group consisting of Mannich dispersants, polymeric dispersants, carboxylic dispersants, amine dispersants, polyisobutylene succinimide dispersants and combinations thereof;
 wherein the dispersant component is fuel soluble and is substantially free of ash forming components. 
 
     
     
         6 . The composition of  claim 1  wherein the acid component comprises an acid derived from a polymer selected from the group consisting of: polymers derived from the polymerization of styrene and maleic anhydride; polymers derived from acrylic acid; polymers derived from acrylic acid esters; polymers derived from methacrylic acid; polymers derived from methacrylic acid esters; polymers derived from high molecular weight esters and acids; partially esterified maleic anhydride styrene copolymers; polymers derived from maleic anhydride and alpha olefins and partially esterified versions thereof, polymers derived from esterified maleic anhydride grafted ethylene propylene diene monomer copolymers; a polyacidic compound; surfactants with acidic groups in the backbone; emulsifiers with acidic groups in the backbone; and combinations thereof. 
     
     
         7 . The composition of  claim 1  wherein the acid component comprises an acid selected from the group consisting of: an acid formed from the polymerization of styrene and maleic anhydride; an acid formed from the partial esterification of such a copolymer with one or more C 6  to C 32  alcohols or a mixture of such alcohols; and combinations thereof. 
     
     
         8 . The composition of  claim 1  wherein the acid has a residual acid group with a total acid number >1, preferably 2-100, more preferably 5-50 
     
     
         9 . The composition of  claim 1  further comprising one or more additional fuel additive selected from the group consisting of viscosity modifiers, friction modifiers, detergents, cloud point depressants, pour point depressants, demulsifiers, flow improvers, antistatic agents, other dispersants, antioxidants, antifoams, corrosion/rust inhibitors, extreme pressure/antiwear agents, seal swell agents, lubricity agent, antimisting agents, and mixtures thereof;
 and wherein at least one fuel additive is controlled released over time into a fuel when the gel is in contact with the fuel. 
 
     
     
         10 . The composition of  claim 9  wherein the additional fuel additive is a friction modifier and/or a lubricity agent. 
     
     
         11 . A process for operating an internal combustion engine comprising:
 I. supplying one or more fuel additive gel compositions to the fuel system of the internal combustion engine, where the fuel additive gel composition comprises:   a) a fuel soluble dispersant;   b) a fuel soluble acid selected from the group consisting of an acid formed from a polymer containing acidic groups in the backbone, a polyacidic compound, surfactants with acidic groups in the backbone, emulsifiers with acidic groups in the backbone and mixtures thereof; and   c) optionally at least one additional fuel additive;   wherein the gel composition is substantially free of ash producing components;   II. contacting the fuel and the fuel additive gel composition during the operation of the internal combustion engine;   resulting in a controlled release of at least one of the additives in the fuel additive gel composition into a fuel, where the release is substantially free of the addition of ash into the fuel; and   III. supplying said fuel to an engine during the engine's operation.   
     
     
         12 . The process of  claim 11  wherein the fuel additive gel composition is at least 50% soluble in the fuel in which it is used, on a weight basis. 
     
     
         13 . The process of  claim 11  wherein the release rate of the additive components from the gel composition to the fuel is determined by the fuel; additive gel composition formulation; and wherein the gel formulation comprises one or more additives that only partially dissolve into the fuel over time. 
     
     
         14 . A fuel conditioning device comprising a fuel additive gel composition and a means for containing said gel composition; wherein the fuel additive gel composition comprises:
 a) a fuel soluble dispersant;   b) a fuel soluble acid selected from the group consisting of an acid formed from a polymer containing acidic groups in the backbone, a polyacidic compound, surfactants with acidic groups in the backbone, emulsifiers with acidic groups in the backbone and mixtures thereof; and   c) optionally at least one additional fuel additive;   wherein the gel composition is substantially free of ash producing components;   and wherein the fuel conditioning device may be placed inside and/or connected to the fuel system of an internal combustion engine; and wherein the fuel conditioning device allows for the contacting of the fuel in the fuel system with the fuel additive gel composition, during the operation of the engine as the fuel is supplied to the engine.   
     
     
         15 . The fuel conditioning device of  claim 14  wherein the fuel additive gel composition is at least 50% soluble in the fuel in which it is used, on a weight basis.