Hyperbranched polyesters and their use as wax inhibitor, as pour point depressant, as lubricant or in lubricating oils

Abstract

The invention relates to a method for the preparation of a hyperbranched polyester mixture obtainable by reacting a hydroxyl group containing carboxylic acid (B) with at least one carboxylic acid group and at least two hydroxyl groups with a diol (C) having a molecular weight of more than 100 g/mol, optionally in the presence of at least one further reactant, wherein the at least one further reactant is a polyol (A) having at least three hydroxyl groups under a reaction condition allowing ester and ether formation; and reacting the mixture resulting from step (a) with a hydrophobic carboxylic acid (D) resulting in the hyperbranched polyester mixture. The invention further relates to said hyperbranched polyester mixture and the use as wax inhibitor, as pour point depressant, as lubricant or in lubricating oils.

Claims

1. A method for the preparation of a hyperbranched polyester mixture comprising the steps of: (a) reacting a hydroxyl group containing carboxylic acid (B) with at least one carboxylic acid group and at least two hydroxyl groups with a diol (C) having a molecular weight of more than 100 g/mol, in the presence of at least one further reactant, wherein the at least one further reactant is a polyol (A) having at least three hydroxyl groups under a reaction condition allowing ester and ether formation; and (b) reacting the mixture resulting from step (a) with a hydrophobic carboxylic acid (D) of the formula R.sup.h—COOH, wherein R.sup.h is a hydrocarbon radical with at least 10 carbon atoms or an activated form thereof so that at least 30% of terminal OH groups are converted into hydrophobically modified OC(O)—R.sup.h groups resulting in the hyperbranched polyester mixture.

2. The method of claim 1, wherein the reaction condition in step (a) comprises a reaction temperature of more than 80° C.

3. The method of claim 1, wherein the reaction condition in step (a) comprises acidic conditions.

4. The method of claim 1, wherein the reaction condition in step (a) comprises a reaction temperature of more than 140° C. and is carried out in the presence of an acid.

5. The method of claim 1, wherein the molar ratio of carboxylic acid (B) and polyol (A), (B):(A), is from 1000:1 to 10:1.

6. The method of claim 1, wherein the molar ratio of carboxylic acid (B) and diol (C), (B):(C), is from 1000:1 to 10:1.

7. The method of claim 1, wherein the hyperbranched polyester mixture has an acid number of below 100 mg KOH/g.

8. The method of claim 1, wherein the hyperbranched polyester mixture has an acid number in the range from 50 to 0 mg KOH/g.

9. The method of claim 1, wherein the hyperbranched polyester mixture comprises a polyester showing a partial structure resulting from ether formation of at least one hydroxyl group of polyol (A) with at least one hydroxyl group of diol (C).

10. The method of claim 1, wherein the hyperbranched polyester mixture comprises a polyester showing a partial structure resulting from ester formation of at least one hydroxyl group of polyol (A) with the at least one carboxylic acid group of hydroxyl group containing carboxylic acid (B).

11. The method of claim 1, wherein the hyperbranched polyester mixture comprises a polyester showing a partial structure resulting from ether formation of at least one hydroxyl group of the hydroxyl group containing carboxylic acid (B) with at least one hydroxyl group of diol (C).

12. The method of claim 1, wherein the polyol (A) having at least three hydroxyl groups is a polyol (A) having three hydroxyl groups.

13. The method of claim 1, wherein the polyol (A) having at least three hydroxyl groups is a polyol (A) is 1,1,1-trimethylolpropane, glycerol or an alkoxylated derivative of 1,1,1-trimethylolpropane or glycerol.

14. The method of claim 1, wherein the polyol (A) having at least three hydroxyl groups is 1,1,1-trimethylolpropane.

15. The method of claim 1, wherein the hydroxyl group containing carboxylic acid (B) with at least one carboxylic acid group and at least two hydroxyl groups is a hydroxyl group containing carboxylic acid (B) with one carboxylic acid group and two hydroxyl groups.

16. The method of claim 1, wherein diol (C) is a polymeric diol.

17. The method of claim 1, wherein hydrophobic carboxylic acid (D) is represented by the formula Rh-COOH, wherein R.sup.h is an aliphatic, linear or branched, saturated or unsaturated, aromatic or non-aromatic hydrocarbon group having 10 to 32 carbon atoms.

18. A hyperbranched polyester mixture obtainable by a method of claim 1.

19. A wax inhibitor, a pour point depressant or a lubricant which comprises the hyperbranched polyester mixture of claim 18.

20. A lubricating oil composition comprising: (a) at least one base oil component, (b) hyperbranched polyester mixture obtainable by a method of (i) reacting a hydroxyl group containing carboxylic acid (B) with at least one carboxylic acid group and at least two hydroxyl groups with a diol (C) having a molecular weight of more than 100 g/mol, in the presence of at least one further reactant, wherein the at least one further reactant is a polyol (A) having at least three hydroxyl groups under a reaction condition allowing ester and ether formation: and (ii) reacting the mixture resulting from step (a) with a hydrophobic carboxylic acid (D) or an activated form thereof, wherein at least 30% of terminal OH groups are converted into hydrophobically modified groups resulting in the hyperbranched polyester mixture, and (c) optionally other additives.

Description

EXAMPLES

Example 1

(1) Modified hyperbranched polyester with chain extender

(2) Polyester using trimethylolpropane, dimethylolpropionic acid, polyTHF 1000 and stearic acid

Step 1: Synthesis of the Hyperbranched Polyester

(3) 2.01 g trimethylolpropane (0.015 mol), 402.30 g dimethylolpropionic aicd (3.0 mol), 20.22 g PolyTHF 1000 (BASF SE) (0.020 mol) and 1.27 g methanesulphonic acid (0.013 mol) were added to a 2 L reaction vessel equipped with N2 inlet, thermometer, stirrer and distillation column.

Step 2: Modification with Stearic Acid

(4) In three steps 884.16 g stearic acid and methanesulphonic acid were added to the reaction mixture. After the first addition of 294.72 g (1.04 mol) stearic acid and 0.67 g methanesulphonic acid (0.0070 mol) the pressure of the reaction mixture was reduced to 600 mbar and the reaction mixture was kept under stirring at 150° C. until the acid number reached 45 mg KOH/g. After the second addition of 294.72 g stearic acid (1.04 mol) and 0.72 g methanesuphoric acid (0.0075 mol) the pressure was reduced to 200 mbar and the reaction mixture was kept under stirring at 150° C. until the acid number reached 36 mg KOH/g. After the third addition of 294.72 g (1.04 mol) stearic acid and 0.63 g methanesulphonic acid (0.0065mol) the pressure of the reaction mixture was reduced to 150 mbar and the reaction mixture was kept under stirring at 150° C. until the acid number reached 29 mg KOH/g.

(5) A light brown material was collected.

(6) Characterization Gel permeation chromatography in tetrahydrofuran (THF):

(7) Mn: 2864 g/mol

(8) Mw: 6467 g/mol

(9) PDI: 2.26

Example 2

(10) Polyester using trimethylolpropane, dimethylolpropionic acid, Polypropylenglycol 4000 and stearic acid

Step 1: Synthesis of the Hyperbranched Polyester

(11) 2.01 g trimethylolpropane (0.015 mol), 402.30 g dimethylolpropionic aicd (3.0 mol), 80 g polypropylene glycol (4000 g/mol) (0.020 mol) and 1.27 g methanesulphonic acid (0.013 mol) were added to a 2 L reaction vessel equipped with N2 inlet, thermometer, stirrer and distillation column.

(12) The reaction mixture was slowly heated with the help of an oil bad up to a temperature of 150° C. The reaction mixture was kept at 150° C. reduced pressure (800 mbar) until an acid number of 26 mg KOH/g was reached.

Step 2: Modification with Stearic Acid

(13) In three steps 884.16 g stearic acid and methanesulphonic acid were added to the reaction mixture. After the first addition of 294.72 g (1.04 mol) stearic acid and 0.67 g methanesulphonic acid (0.0070 mol) the pressure of the reaction mixture was reduced to 800 mbar and the reaction mixture was kept under stirring at 150° C. until the acid number reached 43 mg KOH/g. After the second addition of 294.72 g stearic acid (1.04 mol) and 0.72 g methanesuphoric acid (0.0075mol) the pressure was kept at 800 mbar and the reaction mixture was kept under stirring at 150° C. until the acid number reached 36 mg KOH/g. After the third addition of 294.72 g (1.04 mol) stearic acid and 0.63 g methanesulphonic acid (0.0065 mol) the pressure of the reaction mixture was reduced to 500 mbar and the reaction mixture was kept under stirring at 150° C. until the acid number reached 23 mg KOH/g.

(14) A light brown material was collected.

Example 3

(15) Polyester using trimethylolpropane, dimethylolpropionic acid, Polypropylenglycol 2000 and stearic acid

Step 1: Synthesis of the Hyperbranched Polyester

(16) 2.01 g trimethylolpropane (0.015 mol), 402.30 g dimethylolpropionic aicd (3.0 mol), 40 g polypropylene glycol (2000 g/mol) (0.020 mol) and 1.27 g methanesulphonic acid (0.013 mol) were added to a 2 L reaction vessel equipped with N2 inlet, thermometer, stirrer and distillation column.

(17) The reaction mixture was slowly heated with the help of an oil bad up to a temperature of 150° C. The reaction mixture was kept at 150° C. reduced pressure (800 mbar) until 23 ml of water were collected

Step 2: Modification with Stearic Acid

(18) In three steps 884.16 g stearic acid and methanesulphonic acid were added to the reaction mixture. After the first addition of 294.72 g (1.04 mol) stearic acid and 0.67 g methanesulphonic acid (0.0070 mol) the pressure of the reaction mixture was reduced to 700 mbar and the reaction mixture was kept under stirring at 150° C. until the acid number reached 29 mg KOH/g. After the second addition of 294.72 g stearic acid (1.04 mol) and 0.72 g methanesuphoric acid (0.0075) the pressure was kept at 700 mbar and the reaction mixture was kept under stirring at 150° C. until the acid number reached 22 mg KOH/g. After the third addition of 294.72 g (1.04 mol) stearic acid and 0.63 g methanesulphonic acid (0.0065 mol) the pressure of the reaction mixture was reduced to 500 mbar and the reaction mixture was kept under stirring at 150° C. until the acid number reached 23 mg KOH/g.

(19) A light brown material was collected.

(20) Characterization Gel permeation chromatography in tetrahydrofuran (THF):

(21) Mn: 3185 g/mol

(22) Mw: 6645 g/mol

(23) PDI: 2.08

Comparative Example 1

(24) Modified hyperbranched polyester without chain extender

(25) Polyester using trimethylolpropane, dimethylolpropionic acid and stearic acid (No chain extender)

Step 1: Synthesis of the Hyperbranched Polyester

(26) 2.01 g trimethylolpropane (0.015 mol), 402.30 g dimethylolpropionic aicd (3.0 mol), and 1.27 g methanesulphonic acid (0.013 mol) were added to a 2 L reaction vessel equipped with N2 inlet, thermometer, stirrer and distillation column.

(27) The reaction mixture was slowly heated with the help of an oil bad up to a temperature of 150° C. The reaction mixture was kept at 150° C. for 17 hours until an acid number of 68 mg KOH/g was reached.

Step 2: Modification with Stearic Acid

(28) In three steps 884.16 g stearic acid and methanesulphonic acid were added to the reaction mixture. After the first addition of 294.72 g (1.04 mol) stearic acid and 0.67 g methanesulphonic acid (0.0070 mol) the reaction mixture was kept under stirring at 150 C until the acid number reached 51 mg KOH/g. After the second addition of 294.72 g stearic acid (1.04 mol) and 0.72 g methanesuphoric acid (0.0075) the reaction mixture was kept under stirring at 140° C. until the acid number reached 57 mg KOH/g. After the third addition of 294.72 g (1.04 mol) stearic acid and 0.63 g methanesulphonic acid (0.0065 mol) the pressure of the reaction mixture was slowly reduced to 300 mbar and the reaction mixture was kept under stirring at 150° C. until the acid number reached 43 mg KOH/g.

(29) A light brown material was collected.

(30) Characterization Gel permeation chromatography in tetrahydrofuran (THF):

(31) Mn: 2184 g/mol

(32) Mw: 4605 g/mol

(33) PDI: 2.1

Comparative Example 2

(34) Boltorn H20 and stearic acid

(35) (Boltorn H20 is a commercially available product; synthesis protocol according to WO 2013/019704 PCT/US2012/048786, Example 3)

(36) 34.8 g Boltorn H20 (0.020 mol) and 94 g stearic acid (0.330 mol) were added to a 250 mL reaction vessel equipped with N2 inlet, thermometer, stirrer and distillation column. 0.01 g of p-Toluenesulfonic acid were added to the reaction mixture, which was slowly heated with the help of an oil bad up to a temperature of 140° C. The reaction mixture was stirred for 1 h under normal pressure, then 7 hours under stirring at 140° C. under vacuum until the acid number of 13.9 mg KOH/g was reached.

Comparative Example 3:

(37) Boltorn H2O and lauryl acid

(38) (synthesis protocol from WO 2013/019704 PCT/US2012/048786, Example 1)

(39) 34.8 g Boltorn H2O (0.020 mol) and 66.0 lauryl acid (0.329 mol) were added to a 250 mL reaction vessel equipped with N2 inlet, thermometer, stirrer and distillation column. 0.01 g of p-Toluenesulfonic acid were added to the reaction mixture, which was slowly heated with the help of an oil bad up to a temperature of 140° C. The reaction mixture was stirred for 1 h under normal pressure, then 6 hours under stirring at 140° C. under vacuum until the acid number of 14.6 mg KOH/g was reached.

Comparative Example 4:

(40) Boltorn H2O and palmitic acid

(41) (synthesis protocol from WO 2013/019704 PCT/US2012/048786, Example 2)

(42) 34.8 g Boltorn H2O (0.020 mol) and 84.6 palmitic acid (0.329 mol) were added to a 250 mL reaction vessel equipped with N2 inlet, thermometer, stirrer and distillation column. 0.01 g of p-Toluenesulfonic acid were added to the reaction mixture, which was slowly heated with the help of an oil bad up to a temperature of 140° C. The reaction mixture was stirred for 1 h under normal pressure, then 7 hours under stirring at 140° C. under vacuum until the acid number of 17.5 mgKOH/g was reached.

Performance Tests as Pour Point Depressants

(43) The pour point is determined by a Pour Point-Tester 45150 from PSL (Osterode am Harz, Germany). The measurement is carried out analogously to ASTM D5985. For the testing a Wintershall crude oil from the Landau region, Germany, is used with an API gravity of 37°.

(44) A 2 L aluminum bottle containing the crude oil is heated up to 80° C. for 30 minutes in a water bath. 50 mL of the preheated crude oil are transferred to 100 mL plastic bottles and tempered again at 80° C. for 15 minutes. A 10% active solution of the additive (pour point depressant) in Solvesso 150 is dosed in the corresponding amount, to achieve final testing concentration (treat rate). The mixture of crude oil and additive is shaken strongly. Finally, the sample is tempered again at 80° C. for 15 minutes. Then approximately 30 ml of the sample are transferred to the cup of the pour point tester so that it is filled up to the calibration line. The cup is inserted into the pour point tester, the sensor head is put into the sample and the measuring is started.

(45) TABLE-US-00001 Concentration No flow point.sup.1 Pour point.sup.1 Sample additive in ppm in ° C. in ° C. Crude oil — 18.6 21 19.4 21 With additive 500 5.7 6 (Example 1) 7.5 9 With additive 1000 4.4 6 (Example 1) 5.0 6 With additive 500 10.1 12 (Example 2) With additive 1000 9 6, 7 (Example 2) With additive 500 7.5 9 (Example 3) With additive 1000 4.6 6 (Example 3) .sup.1duplicate

(46) A reduction of the pour Point is observed, by adding pour point depressants from example 1, 2 and 3

(47) TABLE-US-00002 Concentration No flow point.sup.1 Pour point.sup.1 Sample additive in ppm in ° C. in ° C. Blank — 21.4 24 20.6 21 Comp. Exa. 1 500 19.1 21 Comp. Exa. 1 1000 15.2 18 Comp. Exa. 2 500 20.4 21 Comp. Exa. 2 1000 20.9 21 Comp. Exa. 3 500 20.4 21 Comp. Exa. 3 1000 20.9 21 Comp. Exa. 4 500 16.7 18 Comp. Exa. 4 1000 13.6 15 * sediment visible in the 10% active solution of reference 4

(48) The absence of chain length extenders (like PolyTHF 1000) shows a negative influence on the solubility of the polymer in Solvesso 150.

Viscosity Ddetermination of Crude Oil Treated with Pour Point Depressants (PPD's) as a Function of the Temperature

(49) The viscosity as a function of the temperature is determined by a Haake RheoStress 1 rheometer (TCP/P, Thermofisher). For the testing a Wintershall crude oil from the Landau region, Germany, is used with an API gravity of 37°. The measurement is performed with the following parameters, because an ASTM or DIN does not exist: start temp 70° C. cooling rate 1° C./min shear rate 10 s.sup.−1 geometry: cone/plate C60/2° CS

(50) A 2 L aluminum bottle containing the crude oil is heated up to 80° C. for 30 minutes in a water bath. 50 mL of the preheated crude oil are transferred to 100 mL plastic bottles and tempered again at 80° C. for 15 minutes. A 10% active solution of the additive (pour point depressant) in Solvesso 150 is dosed in corresponding amount, to achieve final testing concentration (treat rate). The mixture of crude oil and additive is shaken strongly. Finally, the sample is tempered again at 80° C. for 15 minutes. Then approximately 3 ml of the sample are applied to the plate of the rheometer, so that it is fully wetted and the measurement is started. The measuring unit is covered, to prevent evaporation.

(51) Rheology data: Temperature at which the viscosity of the oil reaches ˜1000 mPAs

(52) TABLE-US-00003 Samples T@ 500 ppm T@ 1000 ppm T Raw oil (blank) Example 1 11.1 (1010 mPas)  3.6 (1020 mPas) 22.6 (1020 mPas) Example 2 20.7 (1020 mPas) 12.6 (1010 mPas) 23.1 (1020 mPas) Example 3 21.8 (1020 mPas) 15.8 (1030 mPas) 23.0 (1020 mPas) Comp. Exa. 1 26.5 (1040 mPas) 20.4 (1010 mPas) 24.8 (1040 mPas) Comp. Exa. 2 25.6 (1040 mPas) 23.0 (1020 mPa)  24.8 (1040 mPas) Comp. Exa. 3 24.6 (1020 mPas) 23.7 (1010 mPas) 24.8 (1040 mPas) Comp. Exa. 4 23.2 (1050 mPas) 24.7 (1010 mPas) 26.4 (1060 mPas)

(53) The samples from the examples 1, 2 and 3 reach a viscosity of 1000 mPas at lower temperature with respect to the not-additivated oil (blank) and with respect to the comparative examples 1, 2, 3 and 4.