Mixture of rough and spheroidized resin particles
AssigneeMinnesota Mining and Manufacturing Company
InventorsJames L. White, James G. Berg
Life of this patent
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Abstract
Free flowing resin powder which upon striking a heated article fuses, flows and hardens to provide a protective coating, which powder consists of a mixture of rough and rounded particles, the rough particles having a granular appearance as a result of being pulverized and the rounded particles having smooth, glossy, spheroidized surfaces as a result of being briefly heated to a temperature above the softening point. Preferably each particle of the powder is a blend of thermosetting resin and curing agent.
Claims6
Resin powder for applying protective coatings, which powder consists of a mixture of resin particles which as stored are free flowing at ordinary room temperature and would pass through a screen having openings not exceeding 200 micrometers, which particles have a softening point of at least 60.degree. C. but fuse, flow and harden quickly when heated to moderately elevated temperatures, 30-80% of the particles being rounded and at magnifications of 100 to 250X having a glossy appearance comparable to that of polished granite and correspondingly 70-20% being rough and at magnifications of 100 to 250X having a granular appearance comparable to that of rough-hewn granite, which mixture of rough and rounded particles enhances electrostatic coating operations.
Powdered resin for applying protective coatings consisting of resin particles which as stored are free flowing at ordinary room temperature and would pass through screen having 177-micrometer openings and would not pass screen having 1-micrometer openings, which particles have a softening point of at least 60.degree. C. but fuse, flow and harden quickly when heated to moderately elevated temperatures, characterized in that 30-80% of the particles are rounded and at magnifications of 100 to 250X have a glossy appearance comparable to the appearance of polished granite and correspondingly 70-20% are rough and at magnifications of 100 to 250X have a granular appearance comparable to the appearance of rough-hewn granite.
Dependencies are inferred from the claim text.