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US 4,181,766 AGranted
Laminates comprising weatherable coatings and primer compositions comprising a mixture of an acrylic polymer and a cellulosic ester
AssigneeMinnesota Mining and Manufacturing Company
InventorsBrian H. Williams, J. Lamar Zollinger
Life of this patent
Estimating the term…
Abstract
The ability to withstand weathering by acrylic substrates having an abrasion resistant coating comprising a cured epoxy-terminated silane on the surface thereof is improved by using a particular primer composition between the coating and the substrate. The primer comprises a mixture of an acrylic polymer and cellulose esters of carboxylic acids.
Claims18
A multi-layered article comprising an acrylic substrate comprising at least 70% by weight of units having the formula:
- ##STR6## having coated on one surface thereof a composition comprising:
- (a) 10 to 85 percent by weight of an acrylic polymer comprising repeating units of the formula ##STR7## wherein R is H or CH.sub.3 and R.sup.4 is an alkyl group of 1 to 4 carbon atoms, said polymer having no more than 50% by weight of said repeating units having R.sup.4 groups of more than 2 carbon atoms,
- (b) 15 to 90 percent by weight of cellulose esters of carboxylic acids, said esters having 0.5 to 5.5 percent by weight of unesterified hydroxyl groups, a viscosity at 25.degree. C. of 300 to 10,000 centipoise, and an acyl content of no more than 56 percent by weight derived from carboxylic acids having 2 to 4 carbon atoms and no more than 20 percent by weight of said acyl content being derived from carboxylic acids having fewer than 3 carbon atoms, and
- (c) 0 to 65 percent by weight of an aliphatic epoxy compound,
- and coated over said composition an abrasion resistant coating comprising the cured product of an epoxy-terminated silane.
2 more elements
Dependencies are inferred from the claim text.