Baking oven interior coating and process therefor
AssigneeHenkel Corporation
InventorsChester P. Jarema, Michael A. Stuart
Life of this patent
Estimating the term…
Abstract
A mixture of two stabilizers, one including benzene rings bearing hydroxyl substituents and the other containing divalent sulfur atoms, is effective in stabilizing tacky polymers that remain solid up to a temperature of at least 160° C. particularly polymers of isobutylene, so that the polymers give long service in the ambient atmosphere as protective layers coated on aluminum substrates and used to line the interiors of paint baking ovens. When accumulated foreign materials accumulate on the coatings, the coating and the accumulated foreign materials can be decomposed to largely volatile products by heating to a temperature substantially higher than the service temperature but not high enough to melt the metal substrate for the coating.
Claims20
A liquid coating composition which comprises each of the following components (A)-(D):
- (A) an amount of a component of polymeric material that (i) is solid and (ii) has tack sufficient to be sensed by a brief touch by a normal human finger, both throughout a temperature range from 25 to 160° C.;
- (B) an amount of a component of first stabilizing molecules and moieties thereof, exclusive of molecules and moieties thereof that constitute component (A), each of the first stabilizing component molecules or moieties thereof containing (i) at least one benzene ring that is substituted with at least one hydroxyl moiety and at least two alkyl moieties and (ii) at least one carbon atom bonded by single bonds to four other carbon atoms, alternatively called a “tertiary” carbon atom;
- (C) an amount of a component of second stabilizing molecules or moieties thereof, exclusive of molecules or moieties thereof that constitute component (A) or (B), each of the second stabilizing component molecules or moieties thereof containing (i) at least one divalent sulfur atom that is bonded to two distinct carbon atoms and (ii) at least two carboxyl or carboxylate moieties;
- and
- (D) an amount of a component of solvent, exclusive of materials that constitute part of any of the preceding components, the solvent having a freezing point below 20° C. and a boiling range at a pressure of 1 bar that begins at a temperature that is at least about 70° C. and ends at a temperature that is not more than 230° C. and being present in sufficient amount to dissolve together into a single solution all of components (A), (B), and (C) to form a solution that is liquid at 25° C.,
- said liquid coating composition having the property that, when a volume of the composition is formed into a layer not more than 0.5 millimeter in thickness and heated to at least one temperature not greater than 160° C., in a space containing gas having a pressure no higher than that of the ambient natural atmosphere, at least components (A), (B), and (C) of the composition will be converted within a time of 60 minutes into a coherent tacky solid, and at least a preponderant part of component (D) will be volatilized.
Dependencies are inferred from the claim text.