Low cure powder compositions for heat sensitive substrates
AssigneeH. B. Fuller Licensing & Financing, Inc.
InventorsStephen C. Hart, Jeffrey G. Schmierer, Brian W. Carlson, Stephen C. Larson
Life of this patent
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Abstract
The invention is directed to new thermosetting powder coating compositions comprising acid functional acrylic resin(s); polyepoxy resin(s) and catalyst(s). The powder coating compositions can be applied to substrates, especially heat sensitive substrates such as wood substrates and cured at low temperature and/or shorter time to provide finishes having controllable gloss and/or high hardness. The invention is also directed to an article comprising a heat sensitive substrate, such as wood substrate, and coated and cured on at least one surface of the substrate the powder coating composition of the invention.
Claims40
A powder coating composition comprising:
- a). about 10% to 90% by weight, relative to (a) plus (b), of carboxylic acid functional acrylic resin(s);
- b). about 10% to 90% by weight, relative to (a) plus (b), of polyepoxy resin(s);
- c). a first catalyst which functions primarily as an epoxy homopolymerization catalyst;
- and
- d). a second catalyst which functions primarily as an epoxy/carboxylic acid reaction catalyst.
A powder coating composition comprising:
- a). about 10% to 90% by weight, relative to (a) plus (b), of carboxylic acid functional acrylic resin(s);
- b). about 10% to 90% by weight, relative to (a) plus (b), of polyepoxy resin(s);
- and
- c). a catalyst in an amount sufficient to cure the composition at a temperature of about 300° F. or below for about 30 minutes or less, wherein the composition provides a finish having a pencil hardness of at least 3H.
A powder coating composition in particulate form consisting essentially of a mixture of:
- a). about 10% to 90% by weight, relative to (a) plus (b), of carboxylic acid functional acrylic resin(s);
- b). about 10% to 90% by weight, relative to (a) plus (b), of polyepoxy resin(s);
- c). a catalyst in an amount sufficient to cure the composition at a temperature of about 300° F. or below for about 30 minutes or less;
- and
- d). optionally, a flexibilizing agent.
Dependencies are inferred from the claim text.