摘要:
A two-component coating composition that includes (A) a first component containing an acid functional aliphatic polyester polyol having an acid number of at least 20 mg KOH/g and a hydroxyl number of from 50 to 500 mg KOH/g, and (B) a second component comprising one or more polyisocyanates. The composition can be used to coat metal substrates by (i) mixing components (A) and (B) in the above-described composition to form a mixture; and (ii) applying the mixture to a surface of a metal substrate.
摘要:
A hydroxyl functional polyester suitable for use in powder coating formulations and bearing sulfonate salt groups, its preparation, and its use in powder coating formulations with methoxyalkylene amino group bearing curatives are described. These polyester resins preferably have 200.degree. C. ICI cone and plate viscosities between about 10 and 90 Poise, have DSC determined glass transition temperatures of at least about 40.degree. C., have hydroxyl numbers between about 10 and 60, and have a sulfonate salt group content between about 0.25 and 4 weight percent. They are preferably synthesized by esterification or transesterification utilizing a sulfonate salt group bearing reactant such as 5-sodium sulfo isophthalic acid. The sulfonate salt groups, preferably alkali metal salt groups, serve to catalyze the curing reaction between the resin and the curative. A preferred powder coating composition involves a resin based on terephthalic acid, isophthalic acid and neopentyl glycol and tetramethoxymethyl glycol uril in a resin to curative weight ratio of between about 90:10 and 94:6.
摘要:
A powder adhesive comprising a primary rubber bonding polymer and a thermosetting component, and a method for bonding elastomers to metals employing the same. By adding a thermosetting component to a powdered adhesive, the adhesive may be applied to a substrate, sintered and thermoset to provide a sweep resistant adhesive film on the substrate, which may subsequently be bonded to an elastomer. Without a thermosetting component, the adhesive is at risk to re-melt or otherwise soften during a heated elastomer molding operation which in turn could cause the adhesive material to sweep off the substrate.