Polymer formulations in solvents with a high flashpoint, processes for production thereof and use thereof as pour point depressants for crude oils, mineral oils or mineral oil products

Abstract

Polymer formulations comprising at least two different solvents having a flashpoint ≧60° C., and polymeric compositions obtainable by free-radical polymerization of at least one alkyl (meth)acrylate in the presence of at least one ethylene-vinyl ester copolymer. Multistage process for producing such formulations and the use of such formulations as pour point depressants for crude oils, mineral oils or mineral oil products.

1 . A process for producing a polymer formulation at least comprising
 two different solvents and   a polymeric composition obtainable by free-radical polymerization of at least one monoethylenically unsaturated monomer (A) in the presence of at least one ethylene-vinyl ester copolymer (B),
 the monomers (A) comprising at least 70% by weight - based on the amount of all monomers (A)—of at least one alkyl (meth)acrylate (A1) of the general formula H 2 C=CR 1 -COOR 2 where R 1  is H or a methyl group and R 2  is a linear alkyl radical having 12 to 60 carbon atoms, 
 the ethylene-vinyl ester copolymers (B) comprising 55 to 85% by weight of ethylene and 15 to 45% by weight of vinyl esters of the general formula H 2 C=CH-O-(O)C-R 3  (III) where R 3  is H or a C 1 - to C 4  hydrocarbyl radical, and 
 the amount of the monomers (A) being 70 to 90% by weight and that of the ethylene-vinyl ester copolymers (B) 10 to 30% by weight based on the sum of the monomers (A) and the ethylene-vinyl ester copolymers (B) together, 
   wherein the solvents comprise   a nonpolar solvent (S1) comprising saturated aliphatic hydrocarbyl groups and having a flashpoint ≧60° C., and   an aromatic hydrocarbon (S2) having a flashpoint >60° C., said process comprising:   (I) providing a solution at least comprising monomers (A) and ethylene-vinyl ester copolymers (B) each in the abovementioned amounts in at least one solvent (S1), and   (II) free-radically polymerizing the monomers (A) in the presence of the ethylene-vinyl ester copolymers (B) by addition of at least one thermally decomposing initiator for the free-radical polymerization to the solution obtained in (I) and polymerizing at a temperature of at least 50° C., the reaction medium being diluted with solvent (S2) during and/or after the polymerization.   
     
     
         2 . The process according to  claim 1 , wherein solvent (S1) comprises saturated aliphatic hydrocarbons having a flashpoint ≧60° C. 
     
     
         3 . The process according to  claim 2 , wherein process step (I) comprises the following component steps:
 (Ia) preparation of a solution comprising alkyl (meth)acrylates (A1) in at least one aliphatic hydrocarbon as solvent (S1) by esterifying at least one alcohol of the general formula R 2 -OH with (meth)acrylic acid H 2 C=CR 1 -COOH in the presence of solvents (S1), and   (Ib) mixing the solution obtained in process step (Ia) with at least one ethylene-vinyl ester copolymer (B) and optionally further monomers (A) other than (A1).   
     
     
         4 . The process according to  claim 1 , wherein a portion of the solvents solvent (S2) is added during the polymerization and a portion of the solvents solvent (S2) is added after the polymerization. 
     
     
         5 . The process according to  claim 1 , wherein the weight ratio of the solvents S1/S2 is 1:5 to 2:1. 
     
     
         6 . The process according to  claim 1 , wherein the concentration of the monomers (A) in the solvent (S1) at the start of process step (II) is 50 to 85% by weight. 
     
     
         7 . The process according to  claim 1 , wherein the amount of the solvents (S1) and (S2) is such that the concentration of all polymers prepared together at the end of process step (II) is 35 to 55% by weight based on the sum of all components of the solution. 
     
     
         8 . The process according to  claim 1 , wherein the amount of the solvents (S1) and (S2) is such that the concentration of all polymers prepared together at the end of process step (II) is 40 to 50% by weight based on the sum of all components of the solution. 
     
     
         9 . The process according to  claim 1 , wherein the mean molecular weight M w  of the ethylene-vinyl ester copolymers (B) used is at least 30 000 g/mol. 
     
     
         10 . The process according to  claim 1 , wherein the ethylene-vinyl ester copolymers (B) comprise 55 to 75% by weight of ethylene and 25 to 45% by weight of vinyl esters. 
     
     
         11 . The process according to  claim 1 , wherein the ethylene-vinyl ester copolymers (B) comprise 60 to 70% by weight of ethylene and 30 to 40% by weight of vinyl esters. 
     
     
         12 . The process according to  claim 1 , wherein R 3  is a methyl radical. 
     
     
         13 . The process according to  claim 1 , wherein R 2  is a linear alkyl radical having 16 to 30 carbon atoms. 
     
     
         14 . The process according to  claim 1 , wherein R 2  is a linear alkyl radical having 18 to 24 carbon atoms. 
     
     
         15 . The process according to  claim 1 , wherein the amount of the monomers (A) is 75 to 85% by weight and that of the ethylene-vinyl ester copolymers (B) 15 to 25% by weight based on the sum of monomers (A) and ethylene- vinyl ester copolymers (B). 
     
     
         16 . The process according to  claim 1 , wherein the monomers (A) used, as well as monomers (Al), are different (meth)acrylates (A2) of the general formula H 2 C=CR 1 -COOR 4 where R 1  is H or methyl and R 4  is a hydrocarbyl radical selected from the group of R 4a , R 4b , R 4c  and R 4d  radicals and the radicals are each defined as follows:
 R 4a : linear alkyl radicals having 1 to 11 carbon atoms,   R 4b : branched alkyl radicals having 4 to 60 carbon atoms,   R 4c : unsubstituted or alkyl-substituted saturated cyclic hydrocarbyl radicals having 5 to 30 carbon atoms, or   R 4d :unsubstituted or alkyl-substituted aromatic hydrocarbyl radicals having 6 to 30 carbon atoms.   
     
     
         17 . The process according to  claim 1 , wherein the monomers (A) used are exclusively alkyl (meth)acrylates (Al). 
     
     
         18 . A polymer formulation comprising
 two different solvents and   a polymeric composition obtainable by free-radical polymerization of at least one monoethylenically unsaturated monomer (A) in the presence of at least one ethylene-vinyl ester copolymer (B),
 the monomers (A) comprising at least 70% by weight—based on the amount of all monomers (A)—of at least one alkyl (meth)acrylate (A1) of the general formula H 2 C=CR 1 -COOR 2 where R 1  is H or a methyl group and R 2  is a linear alkyl radical having 12 to 60 carbon atoms, 
 the ethylene-vinyl ester copolymers (B) comprising 55 to 85% by weight of ethylene and 15 to 45% by weight of vinyl esters of the general formula H 2 C=CH-O-(O)C-R 3  (III) where R 3  is H or a C 1 - to C 4  hydrocarbyl radical, and 
 the amount of the monomers (A) being 70 to 90% by weight and that of the ethylene-vinyl ester copolymers (B) 10 to 30% by weight based on the sum of the monomers (A) and the ethylene-vinyl ester copolymers (B) together, 
   wherein the solvents comprise at least   a nonpolar solvent (S1) comprising saturated aliphatic hydrocarbyl groups and having a flashpoint ≧60° C., and   an aromatic hydrocarbon (S2) having a flashpoint 60° C.   
     
     
         19 . The formulation according to  claim 18 , wherein solvent (S1) comprises saturated aliphatic hydrocarbons having a flashpoint >60° C. 
     
     
         20 . The process according to  claim 18  or  19 , wherein the weight ratio S1/S2 is 1:5 to 2:1. 
     
     
         21 . The formulation according to  claim 18 , wherein the concentration of all polymers together is 35 to 55% by weight based on the sum of all constituents of the formulation. 
     
     
         22 . The formulation according to  claim 18 , wherein the concentration of all polymers together is 40 to 50% by weight based on the sum of all constituents of the formulation. 
     
     
         23 . The formulation according to  claim 18 , wherein the mean molecular weight M w  of the ethylene-vinyl ester copolymers (B) used is at least 30 000 g/mol. 
     
     
         24 . The formulation according to  claim 18 , wherein the ethylene-vinyl ester copolymers (B) comprise 55 to 75% by weight of ethylene and 25 to 45% by weight of vinyl esters. 
     
     
         25 . The formulation according to  claim 18 , wherein the ethylene-vinyl ester copolymers (B) comprise 60 to 70% by weight of ethylene and 30 to 40% by weight of vinyl esters. 
     
     
         26 . The formulation according to  claim 18 , wherein R 3  is a methyl radical. 
     
     
         27 . The formulation according to  claim 18 , wherein R 2  is a linear alkyl radical having 16 to 30 carbon atoms. 
     
     
         28 . The formulation according to  claim 18 , wherein R 2  is a linear alkyl radical having 18 to 24 carbon atoms. 
     
     
         29 . The formulation according to  claim 18 , wherein the amount of the monomers (A) is 75 to 85% by weight and that of the ethylene-vinyl ester copolymers (B) is 15 to 25% by weight based on the sum of monomers (A) and ethylene-vinyl ester copolymers (B). 
     
     
         30 . The formulation according to  claim 18 , wherein the monomers (A) used, as well as monomers (A), are alkyl (meth)acrylates (A2) of the general formula H 2 C=CR 1 -COOR 4  where R 4  is H or methyl and R 4  is a hydrocarbyl radical selected from the group of R 4a , R 4b , R 4c  and R 4d  radicals and the radicals are each defined as follows:
 R 4a : linear alkyl radicals having 1 to 11 carbon atoms,   R 4b : branched alkyl radicals having 4 to 60 carbon atoms,   R 4c : unsubstituted or alkyl-substituted saturated cyclic hydrocarbyl radicals having 5 to 30 carbon atoms,   R 4d :unsubstituted or alkyl-substituted aromatic hydrocarbyl radicals having 6 to 30 carbon atoms.   
     
     
         31 . The formulation according to  claim 18 , wherein the monomers (A) used are exclusively alkyl (meth)acrylates (A1). 
     
     
         32 . The formulation according to  claim 18 , which is obtainable by means of a process comprising
 I. providing a solution comprising monomers (A) and ethylene-vinyl ester copolymers (B) each in the abovementioned amounts in at least one solvent (S1), and   II. free-radically polymerizing the monomers (A) in the presence of the ethylene-vinyl ester copolymers (B) by addition of at least one thermally decomposing initiator for the free-radical polymerization to the solution obtained in (I) and polymerizing at a temperature of at least 50° C., the reaction medium being diluted with solvent (S2) during and/or after the polymerization.   
     
     
         33 - 39 . (canceled) 
     
     
         40 . A process for producing crude oil, mineral oil, and/or mineral oil products, said process comprising adding at least one formulation according to  claim 18  as a pour point depressant. 
     
     
         41 . The process according to  claim 40 , wherein the formulation used additionally comprises at least one wax dispersant. 
     
     
         42 . The process according to  claim 40 , wherein the amount added of the formulation is 50 to 1500 ppm based on the oil. 
     
     
         43 . The process according to  claim 40 , wherein the oil is crude oil and the formulation is injected into a crude oil pipeline. 
     
     
         44 . The process according to  claim 40 , wherein the oil is crude oil and the formulation is injected into a production well. 
     
     
         45 . The process according to  claim 44 , wherein the injection is effected on an offshore platform. 
     
     
         46 . A process for prevention of wax deposits on surfaces in contact with crude oil, mineral oil, and/or mineral oil products, said process comprising adding at least one formulation according to  claim 1  to the crude oil, mineral oil, and/or mineral oil products.