Epoxy resin powder including ethylene vinyl acetate
AssigneeMinnesota Mining and Manufacturing Company
InventorGerald H. Warnken
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Abstract
Stable, free-flowing epoxy resin powder which fuses to and cures upon striking an object which has been preheated to the curing temperature of the composition to provide a tough protective coating. The composition of the powder differs from the prior art in that it includes 3-30 parts of a copolymer of 2-50% vinyl acetate and 5-75% ethylene per 100 parts of the epoxy resin. The copolymer improves the flexibility of the cured coatings.
Claims6
A homogeneous free-flowing powder which is shelf-stable and when heated to 185.degree.-250.degree. C in contact with a metal article fuses and then gels to provide a tough protective coating, said powder comprising
- a polyglycidyl ether of a polyhydric phenol having a softening point of 70.degree.-150.degree. C,
- a normally solid latent hardening agent for epoxy resin,
- a latent catalyst for accelerating reaction between the polyglycidyl ether and the hardening agent when melted together,
- which powder is characterized by the feature that it incorporates per 100 parts of the polyglycidyl ether 3-30 parts by weight of one or more copolymers of monomers comprising by weight 2-50% vinyl acetate and 5-75% ethylene, which copolymer or copolymers have a melt index or combined melt index of 5-400 and impart extraordinarily good flexibility to cured coatings of the powder without undue effect upon other properties of the coatings.
Dependencies are inferred from the claim text.