Claims
- 1. A method for coating a heat sensitive substrate comprising applying a thermosetting coating powder onto a surface of the substrate and heating the powder to a curing temperature of from about 225° F. to about 300° F., the powder comprising an epoxy resin composition, the epoxy resin composition having a melt viscosity of from about 200 to about 2700 centipoise at 150° C. and further wherein the epoxy resin composition comprises from about 5% to about 20% by weight of a crystalline epoxy resin, and a low temperature curing agent which is latent at a temperature of 230° F. or less.
- 2. The method of claim 1 wherein the low temperature curing agent is a solid blocked polyamine.
- 3. The method of claim 1 further characterized by a catalyst having the general formula: wherein R1, R2, R3, and R4 are independently hydrogen or any substituent which is not reactive with the epoxy resin.
- 4. The method of claim 1 further characterized by a catalyst which is an epoxy adduct of an imidazole having the general formula: wherein R1, R2, R3, and R4 are independently hydrogen or any substituent which is not reactive with the epoxy resin.
- 5. The method of claim 3 wherein R1, R2, R3, and R4 are independently hydrogen, alkyl, aryl, or aralkyl.
- 6. The method of claim 3 wherein R2 is methyl or phenyl and R1, R3, and R4 are hydrogen.
- 7. The method of claim 4 wherein R2 is methyl or phenyl and R1, R3, and R4 are hydrogen.
- 8. The method of claim 3 wherein the amount of catalyst is from about 0.2 to about 5 parts per hundred parts of the resin.
- 9. The method of claim 4 wherein the amount of the epoxy adduct of the imidazole is from about 0.2 to about 5 parts per hundred parts of the resin.
- 10. The method of claim 2 wherein the curing agent is an epoxy adduct of a polyamine.
Parent Case Info
This is a continuation-in-part of application Ser. No. 09/191,938, filed Nov. 13, 1998 pending which was a C-I-P of U.S. application Ser. No. 09/111,419, filed Jul. 7, 1998, (now abandoned), which was a C-I-P of U.S. application Ser. No. 08/964,242, filed Nov. 4, 1997, (now abandoned).
US Referenced Citations (15)
Foreign Referenced Citations (5)
Number |
Date |
Country |
0325146 |
Jul 1989 |
EP |
7-179564 |
Jul 1995 |
JP |
07179564 |
Jul 1995 |
JP |
07258384 |
Sep 1995 |
JP |
7-258384 |
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Continuation in Parts (3)
|
Number |
Date |
Country |
Parent |
09/191938 |
Nov 1998 |
US |
Child |
09/316545 |
|
US |
Parent |
09/111419 |
Jul 1998 |
US |
Child |
09/191938 |
|
US |
Parent |
08/964242 |
Nov 1997 |
US |
Child |
09/111419 |
|
US |