Curable polymers
Described is a method for synthesizing polymer compounds (P), preferably polysiloxanes, comprising at least one carboxylic ester group, in particular (meth)acrylate-containing polysiloxanes, said method being carried out in the presence of conversion products (U) of metal salts, in particular chromium(III) salts, and conversion products of aldehydes and primary amines.
1. A process for producing a polysiloxane having a carboxylic acid ester group, wherein at least one epoxy group bearing polysiloxane is reacted with one or more carboxylic acids to convert to the polysiloxane having a carboxylic acid ester group in the presence of conversion products (C) of (A) and (B), wherein (A) are metal salts and (B) is a reaction product of aldehydes and primary amines, wherein metal salts include salts of di- or triply positively charged metals of subgroups 3 to 12.
2. The process according to claim 1 , wherein the one or more carboxylic acids are selected from acrylic acid, methacrylic acid and a combination thereof, the polysiloxane having a carboxylic acid ester group free of double bonds capable of polymerization.
3. The process according to claim 2 , wherein a ratio of epoxy groups to carboxylic acids of 1:0.5-2.
4. The process according to claim 1 , wherein the metal salts (A) comprise chromium salts.
5. The process according to claim 1 , wherein the aldehydes employed are aliphatic and/or aromatic aldehydes.
6. The process according to claim 1 , wherein the primary amines are selected from the group consisting of substituted or unsubstituted C 6 -C 30 -arylamine, substituted or unsubstituted C 6 -C 30 -heteroarylamine, substituted or unsubstituted C 1 -C 12 -alkyl-C 6 -C 12 -arylamine, substituted or unsubstituted C 1 -C 30 -alkyloxyamine, substituted or unsubstituted cyclic C 3 -C 30 -alkylamine, fatty amines and fatty alcohol amines, primary fatty alcohol amines, obtained from saturated or unsaturated fatty alcohols and addition onto acrylonitrile and subsequent hydrogenation.
7. The process according to claim 1 , wherein the conversion product (C) is employed in amounts of 0.0001 wt % to 5 wt % based on the weight of polysiloxane having a carboxylic ester group.
8. The process according to claim 1 , wherein it is carried out at a temperature of 10° C. to 200° C., and at a pressure of 0.5 to 20 bar.
9. The process according to claim 1 , wherein it is carried out in the presence of a solvent selected from the group consisting of propanol, butanol, glycol, modified glycols, methyl isobutyl ketone, ethyl acetate, butyl acetate, toluene, xylene and isomers of xylene, wherein <20 wt % of solvent are employed, based on the entirety of the reaction mixture.
10. The process according to claim 1 , wherein the polysiloxane is a (meth)acrylate-bearing bolysiloxane.
11. The process according to claim 2 , wherein a ratio of epoxy groups to carboxylic acids of 1:0.6-1.8.
12. The process according to claim 1 , wherein the metal salts (A) comprises chromium(III) acetate.
13. The process according to claim 1 , wherein the aldehyde is salicylaldehyde.
14. The process according to claim 1 , wherein the conversion product (C) is employed in amounts of 0.01 to 0.5 wt % based on the entirety of the polysiloxane.
15. The process according to claim 1 , wherein it is carried out at a temperature of 80° C. to 140° C. and at atmospheric pressure.