Method for Producing Polyol Esters

• US 20150344400A1
• Filed: 08/10/2013
• Published: 12/03/2015
• Est. Priority Date: 09/14/2012
• Status: Active Grant

• Current Assignee: OQ Chemicals GmbH (Oxea SARL)
• Original Assignee: OXEA GmbH (Oxea SARL)
• Inventors: FREY, Guido D., WEBER, Tonia, ARNOLD, Jrg, KREICKMANN, Thorsten, STRUTZ, Heinz
• Granted Patent: US 9,284,253 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C07C 67/08 by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
• CPC Class Codes: C07C 69/28 esterified with dihydroxylic compounds

Abstract

A process for preparing polyol esters by reacting polyols with linear or branched aliphatic monocarboxylic acids having 3 to 20 carbon atoms, is characterized in that a mixture of the starting compounds is allowed to react in the presence of a Lewis acid containing at least one element of groups 4 to 14 of the periodic table of the elements as a catalyst and in the presence of an adsorbent with removal of the water formed, and then the crude ester obtained is aftertreated by adding a further adsorbent which is an acidic activated carbon having a pH of 1 to 6.5.

Claims

1. Process for preparing polyol esters by reacting polyols with linear or branched aliphatic monocarboxylic acids having 3 to 20 carbon atoms, characterized in that a mixture of the starting compounds is allowed to react in the presence of a Lewis acid containing at least one element of groups 4 to 14 of the periodic table of the elements as a catalyst and in the presence of an adsorbent with removal of the water formed, and then the crude ester obtained is aftertreated by adding a further adsorbent.

2. Process according to claim 1, characterized in that the aftertreatment with the further adsorbent is effected at a temperature of room temperature to 140°

C., preferably of 60 to 120°

C.

3. Process according to claim 1, characterized in that a steam treatment is performed in the presence of the further adsorbent.

4. Process according to claim 3, characterized in that the steam treatment is performed at a temperature of 100 to 250°

C., preferably of 150 to 220°

C. and especially of 170 to 200°

C.

5. Process according to one or more of claims 1 to 4, characterized in that the polyol ester is dried at temperatures of 80 to 250°

C., preferably 100 to 180°

C. and at pressures of 0.2 to 500 hPa, preferably 1 to 200 hPa and especially of 1 to 20 hPa.

6. Process according to one or more of claims 1 to 5, characterized in that the further adsorbent used is bleaching earth, alumina, alumina hydrate, clays or activated carbon.

7. Process according to one or more of claims 1 to 6, characterized in that the further adsorbent is an acidic adsorbent having a pH of 1 to 6.5, preferably 2 to 5.5.

8. Process according to one or more of claims 1 to 7, characterized in that 0.05 to 2.5 and preferably 0.1 to 0.75 parts by weight of the further adsorbent are added per 100 parts by weight of crude ester to be treated.

9. Process according to one or more of claims 1 to 8, characterized in that the catalyst is used in an amount of 1.0×

10<sup>−

5</sup> to 20 mol %, based on the starting compound used in deficiency.

10. Process according to claim 9, characterized in that the catalyst is used in an amount of 0.01 to 5 and preferably 0.01 to 2 mol %, based on the starting compound used in deficiency.

11. Process according to one or more of claims 1 to 10, characterized in that the catalyst used is titanium, zirconium, hafnium, iron, zinc, boron, aluminium or tin as elements or in the form of compounds thereof.

12. Process according to claim 11, characterized in that the tin compounds used are tin(II) oxide, tin(II) oxalate, tin(II) carboxylates, tin(IV) alkoxides or organotin compounds.

13. Process according to claim 11, characterized in that the titanium compounds used are alkoxides, acylates, carboxylates or chelates.

14. Process according to claim 11, characterized in that the boron compounds used are boric acid or boric esters.

15. Process according to claim 11, characterized in that the aluminium compounds used are aluminium oxide, aluminium hydroxide, aluminium carboxylates or aluminium alkoxides.

16. Process according to claim 11, characterized in that the zinc compounds used are zinc oxide, zinc sulphate or zinc carboxylates.

17. Process according to one or more of claims 1 to 16, characterized in that 0.1 to 5 and preferably 0.5 to 1.5 parts by weight of adsorbent are used in the reaction of polyols with linear or branched aliphatic monocarboxylic acids having 3 to 20 carbon atoms per 100 parts by weight of reaction mixture.

18. Process according to claim 17, characterized in that the adsorbent used is silica gel, kieselguhr, alumina, alumina hydrates, clays, carbonates or activated carbon.

19. Process according to one or more of claims 1 to 18, characterized in that the polyols used are compounds of the general formula (I)

R(OH)_n 

 

(I)

in which R is an aliphatic or cycloaliphatic hydrocarbyl radical having 2 to 20 and preferably 2 to 10 carbon atoms and n is an integer from 2 to 8, preferably 2, 3, 4, 5 or 6.

20. Process according to one or more of claims 1 to 18, characterized in that the polyols used are compounds of the general formula (II)

H—

(—

O—

[—

CR¹R²-]_m—

)_o—

OH 

 

(II)

in which R¹ and R² are each independently hydrogen, an alkyl radical having 1 to 5 carbon atoms, preferably methyl, ethyl or propyl, or a hydroxyalkyl radical having 1 to 5 carbon atoms, preferably the hydroxymethyl radical, m is an integer from 1 to 10, preferably 1 to 8 and especially 1, 2, 3 or 4, o is an integer from 2 to 15, preferably 2 to 8 and especially 2, 3, 4 or 5.

21. Process according to claim 19, characterized in that the polyols used are 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 2,2-dimethylolbutane, trimethylolethane, trimethylolpropane, trimethylolbutane, 2,2,4-trimethylpentane-1,3-diol, 1,2-hexanediol, 1,6-hexanediol, pentaerythritol, ethylene glycol or 3(4),8(9)-dihydroxymethyltricyclo[5.2.1.0^2,6]decane.

22. Process according to claim 20, characterized in that the polyols used are ditrimethylolpropane, dipentaerythritol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol or tetrapropylene glycol.

23. Process according to one or more of claims 1 to 22, characterized in that the aliphatic monocarboxylic acid converted is propionic acid, n-butyric acid, isobutyric acid, n-pentanoic acid, 2-methylbutyric acid, 3-methylbutyric acid, 2-methylpentanoic acid, n-hexanoic acid, 2-ethylbutyric acid, n-heptanoic acid, 2-methylhexanoic acid, 2-ethylhexanoic acid, n-nonanoic acid, 2-methyloctanoic acid, isononanoic acid, 3,5,5-trimethylhexanoic acid or 2-propylheptanoic acid.

24. Process according to one or more of claims 1 to 23 for preparation of triethylene glycol di-2-ethylhexanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-n-heptanoate or tetraethylene glycol di-2-ethylhexanoate.