Process for curing thermoset resins
View Patent ↗Process for curing a thermoset resin comprising the step of contacting said resin with (i) one or more imines of the structure Formula (I), wherein —y=0 or 1, z=1-4, and y+z≧2, —X is independently selected from O, S, P, NH, N—R1, and N—OH, —R1 is selected from linear or branched, cyclic, bi-cyclic, or tri-cyclic alkylene groups with 2-18 carbon atoms, arylene groups with 6-12 carbon atoms, and aralkylene groups with 2-18 carbon atoms, —R2-R5 are individually selected from hydrogen, linear or branched alkyl groups having 1-18 carbon atoms, cycloalkyl groups having 3-12 carbon atoms, aryl groups having 6-12 carbon atoms, aralkyl groups having 6-18 carbon atoms, alkoxy groups having 1-6 carbon atoms, and aryloxy groups; —each of said R-groups may optionally be substituted with O, S, Si, P, or N-containing substituents, —R4 and R5; R3 and R4; R2, R5 and R1 and R3 may optionally form ring, and (ii) a peroxide.
1. Process for curing a thermoset resin comprising the step of contacting said resin with
(i) one or more imines of the structure
wherein
y=0 or 1, z=1-4, and y+z≧2,
X is independently selected from the group consisting of O, S, P, NH, N—R1, and N—OH
R1 is selected from the group consisting of linear or branched, cyclic, bi-cyclic, or tri-cyclic alkylene groups with 2-18 carbon atoms, arylene groups with 6-12 carbon atoms, and aralkylene groups with 2-18 carbon atoms,
R2-R5 are each individually selected from the group consisting of hydrogen, linear or branched alkyl groups having 1-18 carbon atoms, cycloalkyl groups having 3-12 carbon atoms, aryl groups having 6-12 carbon atoms, aralkyl groups having 6-18 carbon atoms, alkoxy groups having 1-6 carbon atoms, and aryloxy groups;
each of said R-groups may optionally be substituted with O, S, Si, P, or N-containing substituents,
R4 and R5; R3 and R4; R2, R5 and R1 and R3 may optionally form ring, and
(ii) a peroxide.
2. Process according to claim 1 wherein X is an oxygen atom.
3. Process according to claim 1 wherein R5 is hydrogen.
4. Process according to claim 1 wherein R4 is hydrogen.
5. Process according to claim 1 wherein R2 and R3 are alkyl groups.
6. Process according to claim 1 wherein the one or more imines is/are the reaction product of a polyamine and a 3-oxoalkanoic acid alkyl ester.
7. Process according to claim 6 wherein the 3-oxoalkanoic acid alkyl ester is ethyl acetoacetate.
8. Process according to claim 6 wherein the polyamine is isophorone diamine.
9. Process according to claim 6 wherein the polyamine and the 3-oxoalkanoic acid alkyl ester are added individually to the thermoset resin, resulting in in-situ formation of the one or more imines.
10. Process according to claim 6 wherein the polyamine and the 3-oxoalkanoic acid alkyl ester have been reacted to form the one or more imines prior to its/their addition to the thermoset resin.
11. Process according to claim 1 wherein the peroxide is selected from ketone peroxides and organic hydroperoxides.
12. Process according to claim 11 wherein the ketone peroxide is methyl ethyl ketone peroxide, methyl isopropyl ketone peroxide, or methyl isobutyl ketone peroxide.
13. Process according to claim 1 wherein said resin is contacted with said one or more imines in an amount of 0.5 to 2 parts by weight of imine per 100 parts by weight of resin.
14. Process according to claim 1 wherein said resin is contacted with said peroxide in an amount of 1 to 2 parts by weight of peroxide per 100 parts by weight of resin.