Low temperature curable epoxy compositions
A heat curable epoxy composition comprising the contact product of an epoxy resin, an epoxy curing agent and an accelerator for the epoxy curing agent, the curing agent or the accelerator comprising the reaction product of (a) a phenolic resin (a) of general formula: Where R1, R2, R3, R4 are each independently of one another a hydrogen or unbranched or branched alky group having 1 to 17 carbon atoms, and n is an integer form 0 to 50; and (b) a modified amine compound which is the reaction product of an epoxy resin and a methylated polyalkylenepolyamine having one primary or secondary amine and at least two tertiary amines of the general formula: Where R1, R2, R3, R4 and R5 represent hydrogen, methyl or ethyl; n and m independently are integers from 1 to 10 and; X is an integer from 1 to 10.
1. A composition comprising (i) a reaction product of (a) a phenolic resin of general formula (A):
where R 1 , R 2 , R 3 , R 4 are each independently, of one another, a hydrogen or unbranched or branched alky group having 1 to 17 carbon atoms, and n is an integer from 0 to 50; and (b) an adduct of an epoxy resin and a polyalkylenepolyamine having one primary or secondary amine and at least two tertiary amines of the general formula (B):
R 1 , R 2 , R 3 , R 4 and R 5 are hydrogen, methyl or ethyl; n and m independently are integers from 1 to 10; and X is an integer from 1 to 10; (ii) at least one member selected from the group consisting of dicyandiamides and acid anhydrides and (iii) at least one epoxy resin; wherein the composition has a curing temperature of about 80 to about 240 C and a pot life at 25 C of greater than one year.
2. The composition of claim 1 wherein the epoxy resin of (iii) comprises at least one member selected from the group consisting of multifunctional epoxy resins, the glycidyl ethers of polyhydric phenols, glycidyl ethers of dihydric phenols, glycidyl ethers of resorcinol, hydroquinone, bis-(4-hydroxy-3,5-difluorophenyl)-methane, 1,1-bis-(4-hydroxyphenyl)-ethane, 2,2-bis-(4-hydroxy-3-methylphenyl)-propane, 2,2-bis-(4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis-(4-hydroxyphenyl)-propane, and bis-(4-hydroxyphenyl)-methane.
3. The composition of claim 1 wherein the epoxy resin of (iii) has the following structure:
where m is an integer, and R is a divalent hydrocarbon radical of a dihydric phenol.
4. The composition of claim 2 wherein multifunctional epoxy resin comprises the glycidyl ethers of novolac resins.
5. The composition of claim 2 wherein the multifunctional epoxy resin comprises at least one member selected from the group consisting of a diglycidyl ether of bisphenol A a diglycidyl ether of bisphenol-F, an epoxy novolac resin, or any combination thereof.
6. The composition of claim 2 wherein the multifunctional epoxy resin further comprises at least one member selected from the group consisting of styrene oxide, cyclohexene oxide, ethylene oxide, propylene oxide, butylene oxide, the glycidyl ethers of phenol, cresols, tert-butylphenol, other alkyl phenols, butanol, 2-ethylhexanol, C 4 to C 14 alcohols, and combinations thereof.
7. The composition of claim 1 wherein the adduct comprises an adduct of an epoxy resin and poly(N-methyl)azetidine.
8. The composition of claim 1 wherein the adduct comprises an adduct of an epoxy resin and N′-(3-dimethylaminopropyl)-N,N-dimethyl-propane-1,3-diamine.
9. The composition of claim 1 wherein the epoxy resin comprises polyglycidyl ether of Bisphenol A resin.
10. The composition of claim 1 wherein formula (B) comprises a compound wherein R 1 is H, R 2, 3, 4 and 5 are CH 3 , n and m are 3, and X is 1.
11. The composition of claim 1 wherein the composition comprises dicyandiamides.
12. The composition of claim 1 wherein the ratio of reaction product to epoxy resin of (iii) is about 0.3 to about 50 parts by weight reaction product to about 100 parts by weight epoxy resin.
13. The composition of claim 1 wherein the composition comprises acid anhydrides.
14. A composition comprising; (i) the reaction product of (a) an adduct of poly(N-methyl)azetidine and an epoxy resin, and (b) a phenolic resin, (ii) at least one member selected from the group consisting of dicyandiamides and acid anhydrides and (iii) at least one epoxy resin; wherein the composition has a curing temperature of about 80 to about 240 C and a pot life at 25 C of greater than one year.
15. A composition comprising: (i) the reaction product of (a) an adduct of N′-(3-dimethylaminopropyl)-N,N-dimethyl-propane-1,3-diamine and an epoxy resin, and (b) a phenolic resin; (ii) at least one member selected from the group consisting of dicyandiamides and acid anhydrides and (iii) at least one epoxy resin; wherein the composition has a curing temperature of about 80 to about 240 C.
16. A composition comprising: (i) the reaction product of: (a) a phenolic resin of general formula (A):
where R 1 , R 2 , R 3 , R 4 are each independently, of one another, a hydrogen or unbranched or branched alky group having 1 to 17 carbon atoms, and n is an integer from 0 to 50; and (b) an adduct of an epoxy resin and a polyalkylenepolyamine having one primary or secondary amine and at least two tertiary amines of the general formula (B):
R 1 is H; R 2 , R 3 , R 4 and R 5 are methyl or ethyl; n and m independently are integers from 1 to 10; and X is an integer from 1 to 10, (ii) at least one member selected from the group consisting of dicyandiamides and acid anhydrides and (iii) at least one epoxy resin; wherein the composition has a curing temperature of about 80 to about 240 C.
17. The composition of claim 16 wherein the epoxy resin of (iii) has the following structure:
where m is an integer, and R is a divalent hydrocarbon radical of a dihydric phenol.