Use of acid anhydride accelerants for the production of high purity polyol esters

Patent metadata

Field	Value
Publication number	US-10125080-B2
Application number	US-201615741658-A
Country	US
Kind code	B2
Filing date	Jul 8, 2016
Priority date	Jul 9, 2015
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

A method of producing high purity polyol esters comprises reacting a polyol with an excess amount of a linear or branched aliphatic monocarboxylic C3-20 acid to esterify less than the total amount of the polyol present to form an intermediate reaction composition having a hydroxyl value of from 7 to about 50 mg KOH/g. An anhydride of the corresponding linear or branched aliphatic monocarboxylic C3-20 acid is added to the intermediate reaction composition in an amount of from 1 to about 2.5 equivalents of available OH in the intermediate composition to form a reaction mixture. The reaction mixture is heated for 5-30 minutes or until all of the corresponding anhydride has reacted to form a reaction product. The reaction product is then de-acidified. No metal or acid catalyst or bleaching agents are present in any of the above reaction steps at a concentration above about 15 ppm.

First claim

What is claimed is:

1. A method of producing high purity polyol esters comprising:
a) reacting a polyol with an excess amount of a linear or branched aliphatic monocarboxylic C3-20 acid to esterify less than the total amount of the polyol present to form an intermediate reaction composition having a hydroxyl value of from 7 to about 50 mg KOH/g;
b) adding an anhydride of the corresponding linear or branched aliphatic monocarboxylic C3-20 acid to the intermediate reaction composition in an amount of from 1 to about 2.5 equivalents of available OH in the intermediate composition to form a reaction mixture;
c) heating the reaction mixture for 5-30 minutes or until all of the corresponding anhydride has reacted to form a reaction product; and
d) de-acidifying the reaction product;

wherein no catalyst comprising metal, halogen or sulfur or bleaching agent comprising metal, halogen or sulfur is present in any of the above method steps a-c at a concentration above about 15 ppm.

2. The method of claim 1 , wherein the intermediate reaction composition has a hydroxyl value of from about 8 to about 40 mg KOH/g.

3. The method of claim 1 , wherein the intermediate reaction composition has a hydroxyl value of from about 9 to about 30 mg KOH/g.

4. The method of claim 1 , wherein the intermediate reaction composition has a hydroxyl value of from about 10 to about 25 mg KOH/g.

5. The method of claim 1 , wherein steps a-c are carried out at ambient pressure.

6. The method of claim 1 , wherein step a) is carried out at a temperature of from about 170° C. to about 230° C.

7. The method of claim 1 , wherein step a) is carried out for at time of from about 3 to about 5 hours.

8. The method of claim 1 , wherein step c) is carried out at a temperature of from about 150° C. to about 170° C.

9. The method of claim 1 , wherein steps a-c are carried out in the presence of an adsorbent.

10. The method of claim 9 , wherein the adsorbent is activated carbon.

11. The method of claim 1 , wherein step d) comprises vacuum distillation and steam treatment to remove acid and water.

12. The method of claim 1 , further comprising the steps of filtration and drying.

13. The method of claim 1 , wherein the polyol is selected from the group consisting of 1,3-propanediol; 1,3-butanediol; 1,4-butanediol; 1,2-hexanediol; 1,6-hexanediol; neopentyl glycol; trimethylolpropane; penta-erythritol; 2,2,4-trimethylpentane-1,3-diol; glycerol; polyglycerol, isosorbide and 3(4), 8(9)-dihydroxymethyltricyclo[5.2.1.0 2,6 ]decane.

14. The method of claim 1 , wherein the polyol is neopentyl glycol.

15. The method of claim 1 , wherein the monocarboxylic C3-20 acid is branched at the 2-position of the acid.

16. The method of claim 15 , wherein the branching at the 2-position of the acid is a C2-C4 alkyl moiety.

17. The method of claim 1 , wherein the monocarboxylic acid is a C4-16 acid that is branched at the 2-position of the acid with a C2-C4 alkyl moiety.

18. The method of claim 1 , wherein the monocarboxylic acid is 2-Ethylhexanoic Acid.

19. The method of claim 1 , wherein the monocarboxylic acid is 2-propylheptanoic acid.

20. The method of claim 1 , wherein the final product has a hydroxyl value of less than about 1 mg KOH/g.

Assignees

• Cargill Inc

Inventors

• Eubanks John

Classifications

• C10N2040/30

  Refrigerators lubricants {or compressors lubricants} · CPC title

• C10N2070/00

  Specific manufacturing methods for lubricant compositions · CPC title

• C10M2207/2835

  used as base material · CPC title

• C10M105/38

  of polyhydroxy compounds · CPC title

• C11C3/02

  by esterification of fatty acids with glycerol · CPC title