Curing agent for epoxy resins and epoxy resin composition

Abstract

The present invention relates to a curing agent for epoxy resins comprising (A) an epoxy adduct of isophoronediamine, (B) an epoxy adduct of 1,3-bis(aminomethyl) cyclohexane, (C) isophoronediamine and (D) 1,3-bis (aminomethyl) cyclohexane wherein the weight ratio of (D) to (C) (=(D)/(C)) in said curing agent is in the range of 0.04 to 0.22, which can provide an epoxy resin composition with excellent curing performances such as curability under the condition of low temperature, excellent performances of epoxy resin cured coating films, excellent chemical resistance of epoxy resin cured coating films and excellent physical properties of epoxy resin cured products.

Description

Claims

1. A curing agent for epoxy resins comprising the following components (A), (B), (C) and (D) wherein the weight ratio of (D) to (C) (=(D)/(C)) in said curing agent is in the range of 0.04 to 0.22: (A) an epoxy adduct of isophoronediamine obtained by addition reaction of isophoronediamine with a diglycidyl compound(B) an epoxy adduct of 1,3-bis(aminomethyl) cyclohexane obtained by addition reaction of 1,3-bis(aminomethyl) cyclohexane with a diglycidyl compound(C) isophoronediamine(D) 1,3-bis (aminomethyl) cyclohexane

2. The curing agent for epoxy resins according to claim 1, wherein the weight ratio of the total content of epoxy adducts to the total content of diamines (=[the total content of epoxy adducts]/[the total content of diamines]) is in the range of 0.17 to 4.2.

3. The curing agent for epoxy resins according to claim 1 or 2, wherein the reaction proportion in addition reaction of isophoronediamine with the diglycidyl compound (=[the number of amino groups]/[the number of glycidyl groups]) is in the range of 3 to 10.

4. The curing agent for epoxy resins according to claim 2, wherein the reaction proportion in addition reaction of isophoronediamine with the diglycidyl compound (=[the number of amino groups]/[the number of glycidyl groups]) is in the range of 3 to 10.

5. The curing agent for epoxy resins according to claim 1, wherein the reaction proportion in addition reaction of 1,3-bis (aminomethyl) cyclohexane with the diglycidyl compound (=[the number of amino groups]/[the number of glycidyl groups]) is in the range of 3 to 10.

6. The curing agent for epoxy resins according to claim 2, wherein the reaction proportion in addition reaction of 1,3-bis (aminomethyl) cyclohexane with the diglycidyl compound (=[the number of amino groups]/[the number of glycidyl groups]) is in the range of 3 to 10.

7. The curing agent for epoxy resins according to claim 1, wherein the diglycidyl compound added with isophoronediamine is selected from the group consisting of 4,4′-isopropylidenediphenol diglycidylether and 4,4′-methylenediphenol diglycidylether.

8. The curing agent for epoxy resins according to claim 2, wherein the diglycidyl compound added with isophoronediamine is selected from the group consisting of 4,4′-isopropylidenediphenol diglycidylether and 4,4′-methylenediphenol diglycidylether.

9. The curing agent for epoxy resins according to claim 1, wherein the diglycidyl compound added with 1,3-bis (aminomethyl) cyclohexane is selected from the group consisting of 4,4′-isopropylidenediphenol diglycidylether and 4,4′-methylenediphenol diglycidylether.

10. The curing agent for epoxy resins according to claim 2, wherein the diglycidyl compound added with 1,3-bis (aminomethyl) cyclohexane is selected from the group consisting of 4,4′-isopropylidenediphenol diglycidylether and 4,4′-methylenediphenol diglycidylether.

11. An epoxy resin composition comprising an epoxy resin and the curing agent for epoxy resins according to claim 1.

12. An epoxy resin composition comprising an epoxy resin and the curing agent for epoxy resins according to claim 2.

13. An epoxy resin cured product obtained by curing the epoxy resin composition according to claim 11.

14. An epoxy resin cured product obtained by curing the epoxy resin composition according to claim 12.