Polyisobutenyl sulfonates having low polydispersity

Abstract

The present invention provides for polyisobutenyl sulfonates, methods for preparing them, and composition employing them; wherein said polyisobutenyl sulfonates have improved low temperature and high temperature viscometric properties. The polyisobutenyl sulfonates are prepared by sulfonating polyisobutene and reacting the polyisobutenyl sulfonate with an alkali metal or alkaline earth metal, wherein the polyisobutene is characterized by having at least 90 mole percent methyl-vinylidene, a number average molecular weight of about 350 to 5,000, and a ratio of weight average molecular weight to number average molecular weight M w /M n of from about 1.01 to about 1.4.

1 .- 21 . (canceled) 
     
     
         22 . A method of making a polyisobutenyl sulfonate-containing lubricating oil composition, the method comprising admixing an oil of lubricating viscosity with a polyisobutenyl sulfonate prepared by sulfonating polyisobutene and reacting the resulting polyisobutenyl sulfonic acid with a source of an alkali metal or alkaline earth metal, wherein the polyisobutene is characterized by having at least 90 mole percent methyl-vinylidene, a number average molecular weight of about 350 to 5,000, and a ratio of weight average molecular weight to number average molecular weight M w /M n  of from about 1.01 to about 1.4. 
     
     
         23 . The method of  claim 22 , wherein the polyisobutene is derived from a cationic quasi-living polymerization reaction. 
     
     
         24 . The product prepared by the method of  claim 23 . 
     
     
         25 . The product prepared by the method of  claim 22 . 
     
     
         26 . A polyisobutenyl sulfonic acid composition obtained by reacting a polyisobutene characterized by having at least 90 mole percent methyl-vinylidene, a number average molecular weight of about 350 to 5,000, and a ratio of weight average molecular weight to number average molecular weight M w /M n  of less than about 1.4; with a sulfonating agent. 
     
     
         27 . The composition of  claim 26 , wherein the polyisobutene is derived from a quasi-living polymerization reaction which has been functionalized with methallyltrimethylsilane. 
     
     
         28 . The composition of  claim 26 , wherein the polyisobutene is derived from a quasi-living polymerization reaction which has been quenched by a suitable dihydrocarbyl substituted nitrogen containing five membered aromatic compounds selected from the group consisting of pyrroles and imidazoles. 
     
     
         29 . The composition of  claim 26 , wherein the polyisobutene is derived from a quasi-living polymerization reaction which has been quenched by a suitable quenching agent selected from the group consisting of substituted morpholine, substituted thiomorpholine, substituted phenothiazine, provided that the substituted morpholine is not 4-methylmorpoline; and substituted or unsubstituted dihydrobenzo[1,4]oxazine, dihydro[1,4]thiazine and phenoxazine. 
     
     
         30 . The composition of  claim 26 , wherein the polyisobutene is derived from a quasi-living polymerization reaction which has been quenched by a suitable quenching agent selected from group consisting of substituted azoles containing a nitrogen atom and an oxygen or sulfur heteroatom, wherein the substituents are selected so that the substituted azole is able to facilitate in preparing a vinylidene terminated polymer from a quasi-living carbocationically terminated polyisobutene. 
     
     
         31 . The composition of  claim 26 , wherein the polyisobutene is characterized by having at least 95 mole percent methyl-vinylidene. 
     
     
         32 . The composition of  claim 31 , wherein the polyisobutene is characterized by having at least 98 to 100 mole percent methyl-vinylidene. 
     
     
         33 . The composition of  claim 26 , wherein the polyisobutene is characterized by having a number average molecular weight of less than about 550. 
     
     
         34 . The composition of  claim 26 , wherein the polyisobutene is characterized by having a number average molecular weight of greater than about 1000. 
     
     
         35 . The composition of  claim 26 , wherein the polyisobutene is characterized by having a number average molecular weight of greater than about 2000. 
     
     
         36 . The composition of  claim 26 , wherein the polyisobutene is characterized by having a ratio of weight average molecular weight to number average molecular weight Mw/Mn of from 1.01 to 1.3. 
     
     
         37 . The composition of  claim 36 , wherein the polyisobutene is characterized by having a ratio of weight average molecular weight to number average molecular weight Mw/Mn of less than about 1.1 
     
     
         38 . A polyisobutenyl sulfonic acid salt prepared by neutralizing the composition of  claim 26 . 
     
     
         39 . The polyisobutenyl sulfonic acid salt of  claim 38 , wherein an ashless base is used for neutralization. 
     
     
         40 . The polyisobutenyl sulfonic acid salt of  claim 39 , wherein the polyisobutene is characterized by having a number average molecular weight of greater than about 2,000. 
     
     
         41 . The polyisobutenyl sulfonic acid salt of  claim 38 , wherein an alkali metal selected from sodium or potassium is used for neutralization, and wherein the polyisobutene is characterized by having a number average molecular weight of greater than about 2,000. 
     
     
         42 . The polyisobutenyl sulfonic acid salt of  claim 38 , wherein excess alkali metal or alkaline earth metal is incorporated during neutralization. 
     
     
         43 . The polyisobutenyl sulfonic acid salt of  claim 42 , wherein the TBN is greater than 0 to about 60 as determined by ASTM test method D2896. 
     
     
         44 . The polyisobutenyl sulfonic acid salt of  claim 42 , wherein the TBN is from 60 to about 400 as determined by ASTM test method D2896. 
     
     
         45 . The method of  claim 22 , wherein the polyisobutene is characterized by having a ratio of weight average molecular weight to number average molecular weight M w /M n  of less than 1.2. 
     
     
         46 . The method of  claim 22 , wherein the polyisobutene is characterized by having at least 95 mole percent methyl-vinylidene content and a ratio of weight average molecular weight to number average molecular weight M w /M n  of less than 1.2. 
     
     
         47 . The composition of  claim 26 , wherein the polyisobutene is characterized by having a ratio of weight average molecular weight to number average molecular weight M w /M n  of less than 1.2. 
     
     
         48 . The composition of  claim 26 , wherein the polyisobutene is characterized by having at least 95 mole percent methyl-vinylidene content and a ratio of weight average molecular weight to number average molecular weight M w /M n  of less than 1.2. 
     
     
         49 . A polyisobutenyl sulfonate obtained by the process comprising:
 (a) polymerizing isobutene in a quasi-living polymer system to form a quasi-living carbocationically terminated polymer comprising contacting an isobutene monomer with an initiator in the presence of a Lewis Acid selected from the group consisting of titanium tetrahalide, boron trichloride, aluminum trichloride, tin tetrachloride, zinc chloride, and ethyl aluminum dichloride, and a solvent, under suitable quasi-living polymerization reaction conditions to obtain a polyisobutene polymer having a number average molecular weight of about 350 to 5,000, and a ratio of weight average molecular weight to number average molecular weight M w /M n  of less than about 1.4;   (b) contacting the polymer prepared in step (a) with a suitable quenching agent whereby said quenching agent converts the quasi-living carbocationically terminated polymer to a polyisobutene polymer having at least 90 mole percent methylvinylidene content, wherein the suitable quenching agent is a dihydrocarbyl substituted nitrogen-containing five-membered aromatic compound selected from substituted pyrrole and substituted imidazole wherein the substituents are selected so that the substituted pyrrole or substituted imidazole is able to facilitate in preparing a vinylidene terminated polymer from a quasi-living carbocationically terminated polyisobutene; and   (c) reacting the polyisobutene polymer of step (b) with a sulfonating agent in a ratio of 0.9 to 1.2 and thereafter neutralizing with a source of alkali metal or alkaline earth metal.