Granted Patent B2

US 10,189,939 · App. 14/910,144 · Granted Jan 29, 2019

Abstract

Claims (25)

1. A method for curing an epoxy resin; said method comprising adding to the epoxy resin a curing agent comprising a compound of formula (I)

wherein:

X is a difunctional group selected from C 3 -C 10 alkyl and C 4 -C 20 heteroalkyl having only oxygen heteroatoms.

2. The method of claim 1 in which the epoxy resin is an aromatic epoxy resin having a molecular weight no greater than 1000.

3. The method of claim 1 in which the epoxy resin is an adduct of bisphenol A and epichlorohydrin.

4. The method of claim 1 in which a ratio of total equivalents of NH in the curing agent to equivalents of epoxide in the epoxy resin is from 0.5:1 to 1.5:1.

5. The method of claim 1 in which the curing agent comprises at least 40 wt % of at least one compound of formula (I).

6. The method of claim 1 in which X is a difunctional group selected from C 4 -C 10 alkyl and C 6 -C 15 heteroalkyl having only oxygen heteroatoms.

7. The method of claim 1 in which X is a mixture of difunctional groups of formula —CH(CH 3 )CH 2 (OCH 2 CH(CH 3 )) n —, wherein n is an average from 2 to 4.

8. The method of claim 1 in which the curing agent comprises at least 50 wt % of at least one compound of formula (I).

9. A cured epoxy resin prepared by a process comprising mixing and heating a composition comprising an epoxy resin and a curing agent,

wherein the curing agent comprises a compound of formula (I)

wherein:

X is a difunctional group selected from C 3 -C 10 alkyl and C 4 -C 20 heteroalkyl having only oxygen heteroatoms.

10. The cured epoxy resin of claim 9 in which X is selected from C 4 -C 10 alkyl and C 6 -C 15 heteroalkyl having only oxygen heteroatoms.

11. The cured epoxy resin of claim 9 in which X is a mixture of difunctional groups of formula —CH(CH 3 )CH 2 (OCH 2 CH(CH 3 )) n —, wherein n is an average from 2 to 4.

12. The cured epoxy resin of claim 9 in which the epoxy resin is an aromatic epoxy resin having a molecular weight no greater than 1000.

13. The cured epoxy resin of claim 9 in which the epoxy resin is an adduct of bisphenol A and epichlorohydrin.

14. The cured epoxy resin of claim 9 in which a ratio of total equivalents of NH in the curing agent to equivalents of epoxide in the epoxy resin is from 0.5:1 to 1.5:1.

15. The cured epoxy resin of claim 9 in which the curing agent comprises at least 40 wt % of at least one compound of formula (I).

16. The cured epoxy resin of claim 9 in which the curing agent comprises at least 50 wt % of at least one compound of formula (I).

17. A method for curing an epoxy resin; said method comprising adding to the epoxy resin a curing agent comprising a compound of formula (I)

wherein:

X is a difunctional group selected from C 4 -C 10 alkyl and C 4 -C 20 heteroalkyl having only oxygen heteroatoms with a ratio of carbon atoms to oxygen atoms from 5:1 to 2:1; and

a ratio of total equivalents of NH in the curing agent to equivalents of epoxide in the epoxy resin is from 0.5:1 to 1.5:1.

Assignments (6)