Ester formation of fatty acid and hydroxycarboxylic acid
The present invention relates to a process for the transesterification of a fatty acid ester of a lower alcohol and a salt of hydroxycarboxylic acid without making use of organic solvents. The process can also be carried out without added anionic surface active agents.
1. A process for the preparation of a salt of a fatty acid ester of hydroxycarboxylic acid which comprises heating a salt of hydroxycarboxylic acid with a catalyst in admixture with a C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms at a temperature at which there exists a liquid phase and subjecting the mixture to ester interchange whereby the temperature of the process is kept at or below the boiling point of the C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms, wherein the temperature is in the range of 160-200° C.
2. The process according to claim 1 wherein the heating of a salt of hydroxycarboxylic acid with a catalyst in admixture with a C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms occurs in the absence of an organic solvent.
3. The process of claim 1 wherein the temperature is kept between the melting temperature of the salt of hydroxycarboxylic acid and the boiling point of the C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon.
4. The process of claim 1 wherein said hydroxycarboxylic acid is lactic acid.
5. The process according to claim 1 wherein said C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms is a C8-C18 fatty acid ester of a lower alcohol having 1-4 carbon atoms.
6. The process of claim 1 wherein the lower alcohol of said C8-C24 fatty acid ester has 1-2 carbon atoms.
7. The process of claim 6 wherein the C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms is methyl laurate.
8. The process of claim 1 wherein said catalyst is of the following formula:
M-OR
wherein
M is an alkali metal, and
R is H or Me.
9. The process of claim 4 wherein said salt of hydroxycarboxylic acid is sodium lactate.
10. The process of claim 1 wherein the molar ratio of salt hydroxycarboxylic acid to the C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms is from 0.2 to 20 mols per mol.
11. The process according to claim 1 wherein water and the lower alcohol are evaporated.
12. The process according to claim 1 , wherein the catalyst is NaOH or NaOMe.
13. A process for the preparation of a salt of a fatty acid ester of hydroxycarboxylic acid which comprises heating a salt of hydroxycarboxylic acid with a catalyst in admixture with a C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms at a temperature at which there exists a liquid phase and subjecting the mixture to ester interchange whereby the temperature of the process is kept at or below the boiling point of the C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms, wherein the heating of a salt of hydroxycarboxylic acid with a catalyst in admixture with a C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms occurs in the absence of an organic solvent.
14. The process of claim 13 , wherein said hydroxycarboxylic acid is lactic acid.
15. The process of claim 13 , wherein said catalyst is of the following formula:
M-OR
wherein
M is an alkali metal, and
R is H or Me.
16. The process of claim 13 , wherein the temperature is kept between the melting temperature of the salt of hydroxycarboxylic acid and the boiling point of the C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon.
17. The process of claim 13 , wherein the reaction temperature is in the range of 160-200° C.
18. The process of claim 13 , wherein water and the lower alcohol are evaporated.
19. The process of claim 13 , wherein the molar ratio of salt hydroxycarboxylic acid to the C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms is from 0.2 to 20 mols per mol.
20. A process for the preparation of a salt of a fatty acid ester of hydroxycarboxylic acid which comprises heating a salt of hydroxycarboxylic acid with a catalyst in admixture with a C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms at a temperature at which there exists a liquid phase and subjecting the mixture to ester interchange whereby the temperature of the process is kept at or below the boiling point of the C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms, wherein the heating of a salt of hydroxycarboxylic acid with a catalyst in admixture with a C8-C24 fatty acid ester of a lower alcohol having 1-4 carbon atoms occurs in the absence of an amount of an organic solvent necessary to form a liquid state.