Process for the synthesis of aliphatic dialkyl esters from vegetable oils

Patent metadata

Field	Value
Publication number	US-9862671-B2
Application number	US-201515124876-A
Country	US
Kind code	B2
Filing date	Mar 10, 2015
Priority date	Mar 11, 2014
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

This invention relates to a process for obtaining highly pure aliphatic dialkyl esters of saturated dicarboxylic acids from vegetable oils, which can advantageously be used in polymerization. The process comprises the steps of reacting with an aliphatic alcohol a triglycerides mixture containing at least one triglyceride of at least one saturated dicarboxylic acid in the presence of one or more catalysts capable of catalyzing the esterification and transesterification reactions, and separating the dialkyl esters of saturated dicarboxylic acids from the reaction mixture thus obtained.

First claim

The invention claimed is:

1. A process for preparing aliphatic dialkyl esters of saturated dicarboxylic acids from a triglycerides mixture containing
at least one triglyceride of at least one saturated dicarboxylic acid and
at least 65% of glycerides of formula R x —O—CH 2 —CH(OR y )—CH 2 —O—R z , measured by HPLC-MS analysis

wherein R x , R y , R z are independently selected from the group consisting of H, C 6 -C 24 monocarboxylic acid residues and C 6 -C 24 dicarboxylic acid residues, and wherein at least one of R x , R y , R z is a C 6 -C 24 dicarboxylic acid residue,
the said process comprising the steps of:
1) esterifying and/or transesterifying with an aliphatic alcohol said triglycerides mixture, in the presence of one or more catalysts capable of catalysing the esterifying and/or transesterifying;
2) separating the aliphatic dialkyl esters of saturated dicarboxylic acids from the reaction mixture obtained at the end of step 1).

2. The process according to claim 1 , in which said triglycerides mixture is obtained from vegetable oils containing unsaturated carboxylic acids.

3. The process according to claim 2 , in which said triglycerides mixture is obtained by oxidative cleavage of the double bonds in the unsaturated carboxylic acids present in the vegetable oils.

4. The process according to claim 3 , in which the oxidative cleavage is carried out through one or more oxidising agents selected from peroxides and O 2 or mixtures containing O 2 .

5. The process according to claim 2 , in which said triglycerides containing at least one dicarboxylic acid are prepared from vegetable oils containing triglycerides of unsaturated carboxylic acids, by means of the steps of:
a) causing the triglycerides of unsaturated carboxylic acids to react with an oxidising compound in the presence of a catalyst capable of catalysing the reaction of oxidising of the olefin double bond in order to obtain an intermediate compound containing vicinal diols;
b) causing the said intermediate compound to react with oxygen, or a gaseous mixture containing oxygen, with a catalyst capable of catalysing the reaction of oxidising the vicinal diols to carboxyl groups in order to obtain (i) saturated monocarboxylic acids and (ii) triglycerides containing saturated dicarboxylic acids;
c) separating the saturated monocarboxylic acids (i) from the triglycerides containing saturated dicarboxylic acids (ii).

6. The process according to claim 1 in which step 1) is performed in a single stage and in the presence of a strong acid as catalyst.

7. The process according to claim 6 in which the strong acid is selected form sulfuric acid, hydrochloric acid, perchloric acid, alkylsulfonic acids, arylsulfonic acids, sulfonic resins or acid earths of the montmorillonite type.

8. The process according to claim 1 in which step 1) is performed using a weak acid to catalyse the esterification reaction in a first stage and a strong base to catalyse the transesterification reaction in a second stage.

9. The process according to claim 8 in which the weak acid is selected from the group comprising phosphoric acid, tungstic acid, molybdic acid, phosphotungstic acid or weakly acid montmorillonites and the strong base is selected from the group comprising sodium hydroxide, potassium hydroxide, sodium methylate or potassium t-butylate.

10. The process according to claim 1 in which the temperature of the esterification and transesterification reactions in step 1 is comprised between 80 and 200° C.

11. The process according to claim 1 in which the aliphatic alcohol is a straight or branched chain C 1 -C 10 monoalcohol.

12. The process according to claim 11 in which the aliphatic alcohol is selected from methanol, ethanol, n-propanol or n-butanol.

13. The process according to claim 12 in which the aliphatic alcohol is n-butanol.

14. The process according to claim 1 in which said dicarboxylic acids present in the triglycerides in step 1) comprise at least one of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecandicarboxylic acid, dodecandicarboxylic acid, brassylic acid, tetradecandicarboxylic acid or pentadecandicarboxylic acid.

15. The process according to claim 14 in which said dicarboxylic acids comprise azelaic acid.

16. The process according to claim 1 in which the aliphatic diesters of the dicarboxylic acids comprise dibutyl azelate.

17. The process according to claim 3 , in which said triglycerides containing at least one dicarboxylic acid are prepared from vegetable oils containing triglycerides of unsaturated carboxylic acids, by means of the steps of:
a) causing the triglycerides of unsaturated carboxylic acids to react with an oxidising compound in the presence of a catalyst capable of catalysing the reaction of oxidising of the olefin double bond in order to obtain an intermediate compound containing vicinal diols;
b) causing the said intermediate compound to react with oxygen, or a gaseous mixture containing oxygen, with a catalyst capable of catalysing the reaction of oxidising the vicinal diols to carboxyl groups in order to obtain (i) saturated monocarboxylic acids and (ii) triglycerides containing saturated dicarboxylic acids;
c) separating the saturated monocarboxylic acids (i) from the triglycerides containing saturated dicarboxylic acids (ii).

18. The process according to claim 4 , in which said triglycerides containing at least one dicarboxylic acid are prepared from vegetable oils containing triglycerides of unsaturated carboxylic acids, by means of the steps of:
a) causing the triglycerides of unsaturated carboxylic acids to react with an oxidising compound in the presence of a catalyst capable of catalysing the reaction of oxidising of the olefin double bond in order to obtain an intermediate compound containing vicinal diols;
b) causing the said intermediate compound to react with oxygen, or a gaseous mixture containing oxygen, with a catalyst capable of catalysing the reaction of oxidising the vicinal diols to carboxyl groups in order to obtain (i) saturated monocarboxylic acids and (ii) triglycerides containing saturated dicarboxylic acids;
c) separating the saturated monocarboxylic acids (i) from the triglycerides containing saturated dicarboxylic acids (ii).

19. The process according to claim 2 in which step 1) is performed in a single stage and in the presence of a strong acid as catalyst.

20. The process according to claim 3 in which step 1) is performed in a single stage and in the presence of a strong acid as catalyst.

Assignees

• Novamont Spa

Inventors

• Bastioli Catia
• Capuzzi Luigi
• Digioia Francesca

Classifications

• C07C67/313

  by introduction of doubly bound oxygen containing functional groups, e.g. carboxyl groups · CPC title

• C07C67/48

  Separation; Purification; Stabilisation; Use of additives · CPC title

• C07C67/03 Primary

  by reacting an ester group with a hydroxy group · CPC title

• C07C67/31

  by introduction of functional groups containing oxygen only in singly bound form · CPC title

• C07C67/08

  by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds · CPC title