# US 4,393,181 A · Polyfunctional phenolic-melamine epoxy resin curing agents

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- Number: US 4,393,181 A
- Document ID: US4393181A
- Status: Granted
- Kind: A
- Application number: 06/393,974
- Filed: 1982-06-30
- Granted: 1983-07-12
- Earliest claimed: 1982-06-30
- Assignees: Shell Oil Company
- Inventors: Roy A. Allen
- Web page: https://patentgrep.com/patent/US4393181A

## CPC

- C08G 14/12: Chemically modified polycondensates
- C08G 59/621: {Phenols}
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

## Abstract

The present invention is directed to epoxy curing agents prepared by reacting a polyhydric phenol with a hexa-alkyl ether of hexamethylol melamine in an amount to provide at least two phenolic hydroxyl groups to one methoxy group. The invention is further directed to curable epoxy compositions.

## Claims

### Claim 1

An epoxy resin curing agent prepared by reacting a polyhydric phenol with an amino-triazine having the general formula ##STR5## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are the same or different alkyl radicals of 1 to 4 carbon atoms, said polyhydric phenol and amino-triazine being reacted in an amount to provide at least two phenolic hydroxyl groups to one alkoxy group.

### Claim 2 (depends on 1)

The curing agent of claim 1 wherein the polyhydric phenol is 2,2-bis(4-hydroxyphenyl)propane.

### Claim 3 (depends on 1)

The curing agent of claim 1 wherein the amino-triazine is hexamethoxy-methyl melamine.

### Claim 4 (depends on 1)

The curing agent of claim 1 wherein the components are reacted at a temperature of from about 120.degree. C. to about 200.degree. C. until the evolution of methanol essentially ceases.

### Claim 5 (depends on 1)

A heat curable composition, especially suitable for powder coating applications, comprising:
(a) at least one normally solid epoxy resin containing at least one vicinal epoxy group,
(b) a curable amount of a curing agent prepared as in claim 1, and
(c) an alkaline epoxy curing agent accelerator.

### Claim 6 (depends on 5)

The composition of claim 5 wherein the epoxy resin is a glycidyl polyether of 2,2-bis(4-hydroxyphenyl)propane.

### Claim 7 (depends on 5)

The composition of claim 5 wherein the epoxy resin is a glycidyl novolac resin.

### Claim 8 (depends on 5)

The composition of claim 5 wherein the epoxy curing agent accelerator is an imidazole compound.

### Claim 9 (depends on 8)

The composition of claim 8 wherein the imidazole compound is 2-methylimidazole.