Polymer compositions allowing easier handling

Abstract

The invention relates to a polymer composition that can be obtained by means of the free radical polymerisation of A) 95-40 wt. % of alkyl (meth)acrylate containing Ai) 20-95 wt. % of at least one alkyl (meth)acrylate with 16 to 40 C-atoms in the alcohol group, and Aii) 5-80 wt. % of at least one (meth)acrylic acid ester of a C.sub.8-C.sub.22 alcohol carrying a C.sub.6-C.sub.20 alkyl group in the 2-position relative to the hydroxyl group, in the presence of B) 5-60 wt. % ethylene copolymer. The invention also relates to a method for producing same and to the use of same as a flow improver for mineral oils and mineral oil distillates.

Claims

1. A polymer composition prepared by free-radical polymerization of A) 95-40% by weight of alkyl (meth)acrylate comprising Ai) 20-95% by weight of at least one alkyl (meth)acrylate having 16 to 40 carbon atoms in the alkyl radical and Aii) 5-80% by weight of at least one (meth)acrylic ester of a C.sub.5-C.sub.22 alcohol having a C.sub.6-C.sub.20-alkyl radical in the 2 position to the hydroxyl group, where Ai) and Aii) are different than one another, in the presence of B) 5-60% by weight of an ethylene copolymer.

2. The polymer composition as claimed in claim 1, wherein the alkyl (meth)acrylates Ai) are according to the general formula (1)
H.sub.2CC(R.sup.2)COOR.sup.3(1) where R.sup.2 is hydrogen or a methyl group, R.sup.3 is a linear alkyl radical having 16 to 40 carbon atoms.

3. The polymer composition as claimed in claim 1, wherein the alkyl (meth)acrylates Aii) are according to the general formula (2) ##STR00003## where R.sup.2 is hydrogen or a methyl group, R.sup.4 and R.sup.5 are independently a saturated linear alkyl radical having 6 to 20 carbon atoms and the sum total of the carbon atoms in R.sup.4 and R.sup.5 is between 16 and 40.

4. The polymer composition as claimed in claim 1, wherein the alkyl (meth)acrylate A) contains 25% to 90% by weight, of at least one alkyl (meth)acrylate Ai) based on the total weight of A).

5. The polymer composition as claimed in claim 1, wherein the alkyl (meth)acrylate A) contains 10% to 60% by weight, of at least one alkyl (meth)acrylate Aii) based on the total weight of A).

6. The polymer composition as claimed in claim 1, wherein the alkyl (meth)acrylate A) contains up to 40% by weight of one or more further monomers Aiii).

7. The polymer composition as claimed in claim 6, wherein the further monomers Aiii) are selected from the group consisting of vinyl esters of carboxylic acids having 1 to 20 carbon atoms, -olefins having 6 to 40 carbon atoms, vinylaromatics, ethylenically unsaturated dicarboxylic acids and the anhydrides and esters thereof with C.sub.10-C.sub.30 fatty alcohols, acrylic acid, methacrylic acid, ethylenically unsaturated compounds beating further functional groups, and vinyl and allyl polyglycols.

8. The polymer composition as claimed in claim 6, wherein the further monomers Aiii) according to the formula (3)
H.sub.2CC(R.sup.2)COOR.sup.6(3) where R.sup.2 is hydrogen or a methyl group, R.sup.6 is a linear alkyl radical having 1 to 11 carbon atoms, is a branched alkyl radical having 4 to 17 carbon atoms or is a cyclic alkyl radical having 5 to 20 carbon atoms.

9. The polymer composition as claimed in claim 6, wherein the further monomers Aiii) are vinyl or allyl polyglycols of the formula (4) ##STR00004## in which R.sup.7 is hydrogen or methyl, Z is C.sub.1-C.sub.3-alkylene or a single bond between the R.sup.7-bearing carbon atom and the oxygen atom, R.sup.8 is hydrogen, C.sub.1-C.sub.30-alkyl, cycloalkyl, aryl or C(O)R.sup.10, R.sup.9 is hydrogen or C.sub.1-C.sub.20-alkyl, R.sup.10 is C.sub.1-C.sub.30-alkyl, C.sub.3-C.sub.30-alkenyl, cycloalkyl or aryl and m is a number from 1 to 50.

10. The polymer composition as claimed in claim 1, wherein the ethylene copolymer contains, as well as ethylene, 4 to 18 mol % of at least one vinyl ester, acrylic ester, methacrylic ester, alkyl vinyl ether and/or alkene.

11. The polymer composition as claimed in claim 1, wherein the ethylene copolymer is a copolymer of ethylene and the vinyl ester of a C.sub.1-C.sub.24 carboxylic acid, a C.sub.1-C.sub.22-alkyl (meth)acrylate and/or a C.sub.3-C.sub.24 olefin.

12. The polymer composition as claimed in claim 1, wherein the ethylene copolymer is a copolymer of ethylene and at least one vinyl ester of the formula (6)
CH.sub.2CHOCOR.sup.11(6) in which R.sup.11 is C.sub.1- to C.sub.30-alkyl.

13. The polymer composition as claimed in claim 1, wherein the ethylene copolymer contains vinyl acetate as comonomer.

14. The polymer composition as claimed in claim 1, wherein the ethylene copolymer is a copolymer of ethylene and at least one acrylic or methacrylic ester of the formula (7)
CH.sub.2CR.sup.12COOR.sup.13(7) in which R.sup.12 is hydrogen or methyl and R.sup.13 is C.sub.1- to C.sub.30-alkyl.

15. The polymer composition as claimed in claim 1, wherein the ethylene copolymer has an MFI190 value measured according to DIN 53735 at 190 C. and an applied load of 2.16 kg of between 0.1 and 1200 g/10 min.

16. The polymer composition as claimed in claim 1, prepared by free-radical polymerization of A and B in the presence of a solvent, where the proportion thereof in the total amount of A, B and solvent and of any further auxiliaries is between 35% and 80% by weight.

17. The polymer composition as claimed in claim 6, in which the alkyl (meth)acrylates A) contain 20% to 93% by weight of monomers Ai).

18. The polymer composition as claimed in claim 6, in which the alkyl (meth)acrylates A) contain 5% to 78% by weight of monomers Aii).

19. The polymer composition as claimed in claim 6, in which the alkyl (meth)acrylates A) contain 2% to 40% by weight of monomers Aiii).

20. A process for preparing a polymer composition in which a mixture of A) 95-40% by weight of alkyl (meth)acrylate (A) comprising Ai) 20-95% by weight of at least one alkyl (meth)acrylate having 16 to 40 carbon atoms in the alkyl radical and Aii) 5-80% by weight of at least one (meth)acrylic ester of a C.sub.5-C.sub.22 alcohol having a C.sub.6-C.sub.20-alkyl radical in the 2 position to the hydroxyl group, where Ai) and Aii) are different than one another, in the presence of B) 5-60% by weight of an ethylene copolymer, is copolymerized by adding a free-radical chain initiator.

21. The process as claimed in claim 20, in which the polymerization is conducted in the presence of 0.1 to 10 times the amount of solvent based on the amount of A) and B).

22. The process as claimed in claim 20, in which the solvent is an aliphatic hydrocarbon or an aliphatic hydrocarbon mixture having a flashpoint of at least 60 C.

23. A concentrate comprising 10% to 80% by weight of the polymer composition as claimed in claim 1, and 90% to 20% by weight of organic solvent.

24. The concentrate as claimed in claim 23, wherein the organic solvent is a mixture of aliphatic and aromatic hydrocarbons.

25. The concentrate as claimed in claim 23, wherein the organic solvent contains at least 20% by weight of aromatic hydrocarbons.

26. The concentrate as claimed in claim 23, further comprising, in addition to the polymer composition, a wax dispersant and/or an asphaltene dispersant.

27. A process for improving the cold properties of a paraffin-containing mineral oil selected from the group consisting of crude oils, residue oils and products from mineral oil distillation, comprising the step of adding at least one polymer composition according to claim 1 to paraffin-containing mineral oil.

28. The process as claimed in claim 27, wherein the paraffin-containing mineral oil is crude oil.

29. The process as claimed in claim 27, wherein 10 to 10 000 ppm by weight of the polymer composition is added to the paraffin-containing mineral oil.

Description

EXAMPLES

(1) Preparation of the Polymers

(2) The polymer compositions of the invention, and also the comparative examples, were prepared by esterifying a mixture of linear alcohol and branched alcohol with acrylic acid and/or methacrylic acid in xylene with azeotropic removal of water of reaction. Subsequently, the EVA copolymer was dissolved in the acrylate with addition of further solvent (xylene), so as to form a solution of 60% strength by weight overall. Inertization with nitrogen was followed by free-radical polymerization with 2,2-azobis-2-methylbutyronitrile (AMBN) at 80 C. Table 1 lists the raw materials used for the production of the various polymer compositions.

(3) TABLE-US-00001 TABLE 1 Raw materials used for the production of the polymer compositions EVA 1 Ethylene-vinyl acetate copolymer of 72% by weight of ethylene and 28% by weight of vinyl acetate; melt flow index MFI (@190 C./2.16 kg) of 8 g/10 min. EVA 2 Ethylene-vinyl acetate copolymer of 81% by weight of ethylene and 19% by weight of vinyl acetate; melt flow index MFI (@190 C./2.16 kg) of 12 g/10 min. EVA 3 Terpolymer of 69% by weight of ethylene; 16% by weight of vinyl acetate and 15% by weight of 2-ethylhexyl acrylate; melt flow index MFI (@190 C./2.16 kg) of 32 g/10 min. BA 1 Behenyl acrylate: technical grade mixture of 39% by weight of C.sub.18-, 13% by weight of C.sub.20- and 48% by weight of C.sub.22-acrylates with a linear alkyl radical BA 2 Behenyl acrylate: technical grade mixture of 43% by weight of C.sub.18-, 11% by weight of C.sub.20- and 44% by weight of C.sub.22-acrylates with a linear alkyl radical BA 3 Behenyl methacrylate: technical grade mixture of 48% by weight of C.sub.18-, 9% by weight of C.sub.20- and 43% by weight of C.sub.22-acrylates with a linear alkyl radical GA 1 2-Dodecylhexadecyl acrylate GA 2 2-Octyldodecyl acrylate GA 3 2-Tetradecyloctadecyl acrylate tBA tert-Butyl acrylate IDTA Isotridecyl acrylate OA Oleyl acrylate 2-EHA 2-Ethylhexyl acrylate

Example 1: Preparation of a Copolymer of Behenyl Acrylate and 2-Dodecyl-Hexadecyl Acrylate (1:1) in the Presence of EVA 1

(4) In a polymerization vessel with Teflon stirrer, jacketed coil condenser, thermometer, gas inlet tube and dropping funnel, 182.9 g of behenyl acrylate (BA 1) and 237.7 g of 2-dodecylhexadecyl acrylate (GA 1) were dissolved in 188 g of xylene at 90 C. While stirring, 141.6 g of the ethylene-vinyl acetate copolymer EVA 1 and a further 108.1 g of xylene were added until there was a homogeneous solution. At 70 C., 1.78 g of the 2,2-azobis(2-methylbutyronitrile) initiator (Peroxan AIVN) dissolved in 80.0 g of xylene were metered in over the course of 1 hour. After a further 4 hours of reaction time at 70 C., the mixture was stirred at 90 C. for a further hour to destroy initiator residues.

(5) The solution obtained had a concentration of 60% by weight of the polymer composition. To assess the flowability, the reaction product was diluted with Solvent Naphtha, a high-boiling aromatic hydrocarbon mixture having a boiling range from 185 to 215 C., to a polymer content of 35% by weight and homogenized at 90 C. At this dilution, the dynamic viscosity was determined at 40 C. to DIN ISO 3219 and the intrinsic pour point of the product to DIN ISO 3016. The values ascertained are reported in table 2.

(6) The further examples and comparative examples were conducted according to the same method with the raw materials and ratios listed in table 2. Unless stated otherwise, percentages are based on parts by weight.

(7) TABLE-US-00002 TABLE 2 Characterization of the polymer compositions used Total Acrylate, composition EVA (B) acrylate linear (Ai) 2-branched (Aii) others (Aiii) Visc.@40 C. Pour point Polymer [% by wt.] [% by wt.] [mol %] [mol %] [mol %] [mPas] [ C.] P1 25% EVA1 75% 50% BA 1 50% GA1 167 9 P2 25% EVA1 75% 70% BA 1 30% GA1 207 6 P3 25% EVA1 75% 90% BA 1 10% GA1 288 21 P4 25% EVA1 75% 25% BA 1 75% GA1 131 27 P5 25% EVA1 75% 50% BA 1 50% GA2 172 6 P6 25% EVA1 75% 50% BA 1 50% GA3 161 3 P7 25% EVA1 75% 50% BA 1 25% GA1 25% OA 169 6 P8 25% EVA1 75% 50% BA 1 25% GA1 25% ITDA 167 3 P9 25% EVA1 75% 45% BA 1 25% GA1 30% ITDA 158 9 P10 25% EVA1 75% 50% BA 1 25% GA1 25% tBA 145 3 P11 20% EVA1 80% 45% BA 1 25% GA 1 30% ITDA 125 6 P12 25% EVA1 75% 34% BA 2 33% GA 1 33% OA 99 18 P13 25% EVA1 75% 50% BA 2 25% GA 1 25% OA 124 6 P14 25% EVA1 75% 50% BA 2 25% GA 1 25% ITDA 112 6 P15 25% EVA1 75% 45% BA 2 25% GA 1 30% ITDA 227 9 P16 35% EVA1 65% 50% BA 2 25% GA 1 25% OA 391 0 P17 25% EVA1 75% 45% BA 2 25% GA 1 30% ITDA 187 12 P18 25% EVA1 75% 50% BA 2 50% GA 1 157 9 P19 25% EVA1 75% 50% BA 3 50% GA3 620 12 P20 25% EVA2 75% 50% BA 1 50% GA 1 234 3 P21 20% EVA3 80% 50% BA 3 50% GA3 187 9 Comp. 1 25% EVA1 75% 100% BA 1 206 24 Comp. 2 20% EVA1 80% 100% BA 2 132 27 Comp. 3 25% EVA1 75% 50% BA 1 50% tBA 106 6 Comp. 4 20% EVA1 80% 45% BA 1 55% ITDA 118 12 Comp. 5 25% EVA1 75% 70% BA 1 30% 2-EHA 232 12 Comp. 6 25% EVA1 75% 100% BA 3 666 0 Comp. 7 25% EVA1 75% 100% GA1 94 39

(8) For the determination of the efficacy thereof, the polymer compositions were added to crude oils or residue oils and the pour point depression achieved as a result (pour point according to ASTM D97) in the oil was determined. The test oils O1, O2 and O4 were crude oils of West African provenance, and O3 was a crude oil of North African provenance. Test oil 5 was a residue from crude oil distillation. The characterization of the crude oils used is reported in table 3. The composition of oils was undertaken by means of SARA analysis according to IP 469-01. This involved determining the proportions in the crude oils of saturated hydrocarbons (Sat.), aromatics (Arom.), resins (Res.) and asphaltenes (Asph.). The wax appearance temperature (WAT) was determined by means of dynamic differential calorimetry (DSC). The starting temperature for the measurements was chosen such that it was at least 10 C. above the WAT. The samples were cooled at a cooling rate of 2.5 K/min. The commencement of exothermic paraffin crystallization is shown by the WAT. The pour point depressions achieved in the crude oils O1 to O4 are shown in tables 4 to 7.

(9) TABLE-US-00003 TABLE 3 Characterization of test oils O1 to O5 Pour Point SARA analysis (blank) Asph. WAT Test oil [ C.] Sat. [%] Arom. [%] Res. [%] [%] [ C.] O1 15 53 22 24 1 30 O2 15 50 24 25 1 24 O3 30 71 18 5 6 36 O4 12 60 29 10 1 20 O5 18 29 50 13 8 16

(10) TABLE-US-00004 TABLE 4 Pour point depression in test oil O1; blank PP + 15 C. Example Polymer 100 ppm 1 P1 3 2 P2 6 3 P3 6 4 P4 9 5 P5 0 6 P6 6 7 P7 0 8 P8 3 9 P9 3 10 P10 3 11 P11 6 12 P12 9 13 P13 6 14 P14 0 15 P15 0 16 P16 3 17 P17 0 18 P18 0 19 P19 6 20 (C) Comp. 1 6 21 (C) Comp. 2 3 22 (C) Comp. 3 6 23 (C) Comp. 4 6 24 (C) Comp. 5 0 25 (C) Comp. 6 6 26 (C) Comp. 7 15

(11) TABLE-US-00005 TABLE 5 Pour point depression in test oil O2; blank PP + 15 Example Polymer 100 ppm 27 P1 15 28 P2 18 29 P3 12 30 P4 6 31 P5 15 32 P6 15 33 P9 18 34 P13 15 35 P14 12 36 P15 12 37 P16 21 38 P17 15 39 P18 18 40 P19 18 41 P20 18 42 (C) Comp. 1 24 43 (C) Comp. 2 21 44 (C) Comp. 6 21

(12) TABLE-US-00006 TABLE 6 Pour point depression in test oil O3; blank PP + 30 Example Polymer 1000 ppm 45 P1 15 46 P5 12 47 P8 18 48 P11 15 49 P12 15 50 P13 18 51 P14 12 52 P18 12 53 P20 18 54 (C) Comp. 1 15 55 (C) Comp. 2 9 56 (C) Comp. 3 21 57 (C) Comp. 7 27

(13) TABLE-US-00007 TABLE 7 Pour point depression in test oil O4; blank PP + 12 Example Polymer 100 ppm 200 ppm 58 P1 3 6 59 P2 0 12 60 P3 3 15 61 P4 9 3 62 P5 6 0 63 P6 0 12 64 P 10 0 12 65 P13 9 12 66 P15 3 6 67 P16 3 9 68 P17 9 3 69 P18 9 0 70 P19 6 6 71 P21 3 9 72 (C) Comp. 1 9 15 73 (C) Comp. 2 6 15 74 (C) Comp. 3 9 6 75 (C) Comp. 5 3 3 76 (C) Comp. 6 6 3 77 (C) Comp. 7 9 9

(14) TABLE-US-00008 TABLE 8 Pour point depression in refinery residue O5; blank PP + 18 Example Polymer 1500 ppm 78 P1 9 79 P2 0 80 P3 3 81 P4 3 82 P5 6 83 P6 0 84 P7 6 85 P8 3 86 P9 9 87 P11 3 88 P12 3 89 P14 6 90 P15 6 91 P16 9 92 P17 9 93 P18 12 94 P21 9 95 (C) Comp. 1 3 96 (C) Comp. 2 6 97 (C) Comp. 4 3

(15) To assess the flowability of concentrates of the novel polymer compositions during prolonged storage at low temperatures, the polymer compositions were dissolved at 50 C. in Solvent Naphtha (high-boiling aromatics mixture with boiling range of 185-215 C.) with a polymer content of 35% by weight and left to cool gradually to room temperature. After storage of a 100 ml sample at room temperature for 15 hours, flowability was tested in analogy to ASTM D79 by tilting the sample vessel. Movement of the surface on tilting of the sample bottle showed that the sample was free-flowing and was recorded as OK; the presence of gel structures was additionally recorded as gel. The products were then stored at 0 C. in a climate-controlled cabinet. The first assessment of flowability was made after storage at 0 C. for 6 hours; the assessment of the long-term flowability/pumpability was made after storage at 0 C. for a further 10 days by the same testing and assessment principles. In the assessment of flowability, possible gel formation/inhomogeneity was additionally tested.

(16) TABLE-US-00009 TABLE 9 Assessment of storage stability and flowability Flowability Flowability at 0 C., at 0 C., Flowability storage storage Example Polymer at RT for 6 h for 10 days 98 P1 OK OK OK 99 P2 OK solid solid 100 P3 OK solid solid 101 P4 OK OK OK 102 P5 OK OK OK 103 P5 OK OK OK 104 P6 OK OK OK 105 P7 OK OK OK 106 P8 OK OK OK 107 P9 OK OK OK 108 P10 OK OK OK 109 P11 OK OK OK 110 P19 OK OK OK 111 P20 OK OK OK 112 P21 OK OK OK 113 (C) Comp. 1 free-flowing/gel solid solid 114 (C) Comp. 2 solid solid solid 115 (C) Comp. 3 OK OK viscous/gel 116 (C) Comp. 4 OK solid solid 117 (C) Comp. 5 OK solid solid 118 (C) Comp. 6 OK viscous/gel solid

(17) The additives of the invention, in the form of concentrates, have very good flowability at low temperatures and simultaneously superior efficacy on the pour point of crude oils. The short-chain or branched alkyl acrylates of WO 2014/095412 that were proposed in a similar context lower the intrinsic pour point of the additives only slightly, but are not capable of cocrystallization with the paraffins that precipitate out of the oil to be additized and hence attenuate the efficacy of the additives to a greater degree.