Glycerol (meth)acrylate carboxylic ester having a long shelf life

1. A method for preparing storage-stable glycerol (meth)acrylate carboxylic esters of formula (I):

wherein:

R 1 =H or CH 3 ;

R 2 =hydrogen; a C1 to C30 aliphatic group optionally with a hydroxyl substituent; an aliphatic cyclic group with a C4 to C8 ring unsubstituted or substituted by N, S, O or P; a C1 to C8 halogenated aliphatic group; an aromatic group having a ring with five or six carbons and optionally with a hydroxyl substituent; a heteroaromatic group substituted by N, S, O or P and having a ring with five or six carbons; or a C2 to C30 unsaturated aliphatic group;

said method comprising the steps of:

a) reacting carboxylic acids of formula (II) with glycidyl (meth)acrylate at a temperature of 20-130° C. in the presence of a catalyst, by initially charging the carboxylic acids of formula (II) and adding glycidyl (meth)acrylate continuously, wherein the carboxylic acids of formula (II) have the structure:

wherein R 2 =hydrogen; a C1 to C30 aliphatic group optionally with a hydroxyl substituent; an aliphatic cyclic group with a C4 to C8 ring unsubstituted or substituted by N, S, O or P; a C1 to C8 halogenated aliphatic group; an aromatic group having a ring with five or six carbons and optionally with a hydroxyl substituent; a heteroaromatic group substituted by N, S, O or P and having a ring with five or six carbons; or a C2 to C30 unsaturated aliphatic group;

b) optionally, after the reaction is complete and prior to storage, adding foreign carboxylic acids of formula (III) and/or foreign Broensted acids, wherein the carboxylic acids of formula (III) have the structure:

wherein R 3 is defined as for R 2 ;

c) storing the storage stable glycerol (meth)acrylate carboxylic esters of formula (I) with the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula III and foreign Broensted acids;

wherein, at the beginning of storage, the sum total of the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula (III) and foreign Broensted acids is in molar excess to the glycidyl (meth)acrylate present.

2. The method of claim 1 , wherein the molar ratio of the sum total of the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula (III) and foreign Broensted acids to glycidyl (meth)acrylate is from 1.001:1 to 5:1.

3. The method of claim 1 , wherein the molar ratio of the sum total of the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula (III) and foreign Broensted acids to glycidyl (meth)acrylate is from 1.01:1 to 2:1.

4. The method of claim 1 , wherein the molar ratio of endogenous carboxylic acids of formula (II) to glycidyl (meth)acrylate at the end of the reaction is above 1:1 and neither foreign carboxylic acids of formula (III) nor foreign Broensted acids are added prior to storage.

5. The method of claim 1 , wherein the molar ratio of endogenous carboxylic acids of formula (II) to glycidyl (meth)acrylate, at the end of the reaction is below 1:1 but is adjusted to greater than 1:1 by addition of foreign carboxylic acids (III) and/or Broensted acids prior to storage.

6. The method of claim 1 , wherein the molar ratio of endogenous carboxylic acids of formula (II) to glycidyl (meth)acrylate, at the end of the reaction is below 1:1 but is adjusted to greater than 1:1 by addition of carboxylic acids (III) without Broensted acids.

7. The method of claim 1 , wherein the molar stoichiometry (glycidyl methacrylate: carboxylic acid) during the reaction is at least 1.02:1.

8. The method of claim 1 , wherein glycidyl (meth)acrylate and carboxylic acid (II) are reacted in the presence of catalytic amounts of a quaternary alkylammonium halide.

9. The method of claim 8 , wherein the quaternary alkylammonium halide is benzyltriethylammonium chloride.

10. The method of claim 1 , wherein, in step c), the glycerol (meth)acrylate carboxylic esters of formula (I) are stored for a period of at least three months at a temperature of up to 50° C. and maintain a diester content of 85% or greater and a triester content of 3% or less.

11. The method of claim 1 , wherein, in step c), the glycerol (meth)acrylate carboxylic esters of formula (I) are stored for a period of at least six months at a temperature of up to 30° C. and maintain a diester content of 85% or greater and a triester content of 3% or less.

12. The method of claim 1 , wherein R 2 is a C1 to C30 aliphatic group, or an aliphatic cyclic group with a C4 to C8 ring, unsubstituted or substituted by N, S, O or P.

13. The method of claim 1 , wherein R 2 is an aromatic group having a ring with up to six carbons or a heteroaromatic group substituted by N, S, O or P and having a ring with up to six carbons, or a C2 to C30 unsaturated aliphatic group.

14. The method of claim 2 , wherein glycidyl (meth)acrylate and endogenous carboxylic acids of formula (II) are reacted in the presence of catalytic amounts of a quaternary alkylammonium halide.

15. The method of claim 14 , wherein the quaternary alkylammonium halide is benzyltriethylammonium chloride.

16. The method of claim 15 , wherein, in step c), the glycerol (meth)acrylate carboxylic esters of formula (I) are stored for a period of at least three months at a temperature of up to 50° C. and maintain a diester content of 85% or greater and a triester content of 3% or less.

17. A method for preparing storage-stable glycerol (meth)acrylate carboxylic esters of formula (I):

wherein:

R 1 =H or CH 3 ;

R 2 =hydrogen; a C1 to C30 aliphatic group optionally with a hydroxyl substituent; an aliphatic cyclic group with a C4 to C8 ring unsubstituted or substituted by N, S, O or P; a C1 to C8 halogenated aliphatic group; an aromatic group having a ring with five or six carbons and optionally with a hydroxyl substituent; a heteroaromatic group substituted by N, S, 0 or P and having a ring with five or six carbons; or a C2 to C30 unsaturated aliphatic group;

said method comprising:

a) making the storage-stable glycerol (meth)acrylate carboxylic esters of formula (I) by a procedure consisting essentially of reacting carboxylic acids of formula (II) with glycidyl (meth)acrylate at a temperature of 20-130° C. in the presence of a catalyst, wherein the carboxylic acids of formula (II) have the structure:

R 2 =hydrogen; a C1 to C30 aliphatic group optionally with a hydroxyl substituent; an aliphatic cyclic group with a C4 to C8 ring unsubstituted or substituted by N, S, O or P; a C1 to C8 halogenated aliphatic group; an aromatic group having a ring with five or six carbons and optionally with a hydroxyl substituent; a heteroaromatic group substituted by N, S, or P and having a ring with five or six carbons; or a C2 to C30 unsaturated aliphatic group;

b) optionally, after the reaction of step a) is complete and prior to storage, adding foreign carboxylic acids of formula (III) and/or foreign Broensted acids, wherein the carboxylic acids of formula (III) have the structure:

wherein R 3 is defined as for R 2 ;

c) storing the storage stable glycerol (meth)acrylate carboxylic esters of formula (I) with the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula III and foreign Broensted acids;

wherein, at the beginning of storage, the sum total of the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula (III) and foreign Broensted acids is in molar excess to the glycidyl (meth)acrylate present.

18. The method of claim 1 , wherein the carboxylic acids of formulas II and III are selected from the group consisting of: acetic acid, butyric acid, stearic acid, benzoic acid, salicylic acid, nicotinic acid, proline, acrylic acid, oleic acid, lactic acid, hydroxyisobutyric acid, trichloroacetic acid, or methacrylic acid.

19. The method of claim 1 , wherein the molar ratio of the sum total of the endogenous carboxylic acids of formula (II), foreign carboxylic acids of formula (III) and foreign Broensted acids to glycidyl (meth)acrylate is from 1.01:1 to 5:1.

20. The method of claim 1 , wherein foreign carboxylic acids of formula (III) and/or foreign Broensted acids are added in step b) prior to storage.