Processes for Preparing Low Viscosity Lubricants

Abstract

Disclosed are processes for forming an oligomer product by contacting a feedstock olefin containing trisubstituted olefins with a solid acid catalyst. The oligomer product can be formed at an oligomerization temperature in a range from −20° C. to 40° C. Polyalphaolefins produced from the oligomer product can have reduced viscosities at low temperatures.

We claim: 
     
         1 . A process comprising contacting a feedstock olefin with a solid acid catalyst to form an oligomer product at an oligomerization temperature in a range from −20° C. to 40° C., wherein the feedstock olefin comprises trisubstituted olefins. 
     
     
         2 . The process of  claim 1 , wherein the solid acid catalyst comprises an acidic ion exchange resin. 
     
     
         3 . The process of  claim 1 , wherein the solid acid catalyst comprises a functionalized styrene-divinylbenzene polymer, a 4-vinylpyridine divinylbenzene polymer, a tetrafluoroethylene polymer modified with perfluorovinyl ether groups terminated with sulfonate groups, or a combination thereof. 
     
     
         4 . The process of  claim 1 , wherein the solid acid catalyst comprises an AMBERLYST® resin, a NAFION® resin, or a combination thereof. 
     
     
         5 . The process of  claim 1 , wherein the solid acid catalyst comprises AMBERLYST® 15 resin. 
     
     
         6 . The process of  claim 1 , wherein:
 the oligomerization temperature is in a range from 15° C. to 35° C.; and   the feedstock olefin comprises at least 75 wt. % C 16  to C 24  trisubstituted olefins.   
     
     
         7 . The process of  claim 1 , wherein the feedstock olefin is produced by a process comprising isomerizing a vinylidene composition comprising a C 12  to C 48  vinylidene. 
     
     
         8 . The process of  claim 1 , wherein the feedstock olefin is produced by a process comprising contacting a monomer comprising a C 6  to C 24  normal alpha olefin with a catalyst system comprising a metallocene compound, a chemically-treated solid oxide, and a co-catalyst. 
     
     
         9 . The process of  claim 1 , wherein the process further comprises a step of removing at least a portion of the oligomer product from the feedstock olefin and the solid acid catalyst. 
     
     
         10 . The process of  claim 9 , wherein the process further comprises a step of hydrogenating the portion of the oligomer product to form a polyalphaolefin. 
     
     
         11 . The process of  claim 10 , wherein the feedstock olefin comprises a compound having the structure: 
       
         
           
           
               
               
           
         
       
       or
 any combination thereof. 
 
     
     
         12 . The process of  claim 10 , wherein the polyalphaolefin comprises:
 at least 80 wt. % C 4 -0 branched hydrocarbons; and   a maximum of 5 wt. %<C 40  hydrocarbons.   
     
     
         13 . The process of  claim 10 , wherein the polyalphaolefin has:
 a kinematic viscosity at −40° C. in a range 5,000 to 9,000 cSt;   a kinematic viscosity at 40° C. in a range from 25 to 50 cSt;   a kinematic viscosity at 100° C. in a range from 4 to 10 cSt;   a viscosity index in a range from 120 to 150;   a pour point in a range from −45 to −85° C.; or   any combination thereof   
     
     
         14 . A process for forming a polyalphaolefin, the process comprising:
 (1) contacting a monomer comprising a C 6  to C 24  normal alpha olefin with a catalyst system to form a dimer composition comprising trisubstituted dimers, the catalyst system comprising a metallocene compound, a chemically-treated solid oxide, and a co-catalyst;   (2) removing at least a portion of the monomer and/or at least a portion of higher oligomers from the dimer composition to form a trisubstituted olefin composition comprising trisubstituted dimers;   (3) contacting the trisubstituted olefin composition with a solid acid catalyst to form an oligomer product comprising olefin tetramers at an oligomerization temperature in a range from −20° C. to 40° C.;   (4) removing at least a portion of the oligomer product from the trisubstituted dimers and the solid acid catalyst to form a tetramer composition comprising olefin tetramers; and   (5) hydrogenating the tetramer composition to form the polyalphaolefin.   
     
     
         15 . The process of  claim 14 , wherein:
 the chemically-treated solid oxide comprises a solid oxide treated with an electron withdrawing anion; and   the co-catalyst comprises an organoaluminum compound, an organozinc compound, an organomagnesium compound, an organolithium compound, or a combination thereof.   
     
     
         16 . The process of  claim 14 , wherein:
 the monomer comprises a C 8  to C 12  normal alpha olefin;   the chemically-treated solid oxide comprises fluorided alumina, chlorided alumina, bromided alumina, sulfated alumina, fluorided silica-alumina, chlorided silica-alumina, bromided silica-alumina, sulfated silica-alumina, fluorided silica-zirconia, chlorided silica-zirconia, bromided silica-zirconia, sulfated silica-zirconia, fluorided silica-titania, fluorided silica-coated alumina, sulfated silica-coated alumina, phosphated silica-coated alumina, or any combination thereof; and   the co-catalyst comprises trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diisobutylaluminum hydride, diethylaluminum ethoxide, diethylaluminum chloride, or any combination thereof   
     
     
         17 . A polyalphaolefin produced by the process of  claim 14 . 
     
     
         18 . A polyalphaolefin comprising at least 80 wt. % C 4 -0 saturated branched hydrocarbons, wherein the polyalphaolefin has a kinematic viscosity at −40° C. in a range from 4,500 to 9,500 cSt. 
     
     
         19 . The polyalphaolefin of  claim 18 , wherein the polyalphaolefin comprises:
 from 82 to 99 wt. % C 4 -0 branched hydrocarbons; and   a maximum of 5 wt. %<C 40  hydrocarbons.   
     
     
         20 . The polyalphaolefin of  claim 18 , wherein the polyalphaolefin has:
 a kinematic viscosity at −40° C. in a range 5,000 to 9,000 cSt;   a kinematic viscosity at 40° C. in a range from 25 to 50 cSt;   a kinematic viscosity at 100° C. in a range from 4 to 10 cSt;   a viscosity index in a range from 120 to 150;   a pour point in a range from −45 to −85° C.; or   any combination thereof.