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US 5,635,555 AGranted
PVC-free coil-coated steel having excellent cut-side corrosion resistance
AssigneeFina Research, S.A.
InventorsPaul Vranken, Philippe Pigeolet
Life of this patent
Estimating the term…
Abstract
PVC-free coil coated steel having excellent cut-side corrosive resistance can be prepared by using on one or both sides a primer composition essentially consisting of a linear polyester of Mn=3,000-15,000, of acid number 0-10, and hydroxyl index 10-25; a blocked polyisocyanate, melamine or an urea-formaldehyde adduct, in an equivalent ratio of 0.8-4.0 to polyester; a catalyst; anti-corrosive pigments of the chromate type, being at least 50 weight percent of all pigments; and solvents.
Claims9
Primer coating composition essentially consisting of
- (i) a binder system consisting essentially of:
- (a) an essentially linear polyester resin having a number-average molecular weight of 3,000 to 15,000, a acid number of 0 to 10 and a hydroxyl index of 10 to 25;
- (b) a cross linking agent selected from the group consisting of block polyisocyanates, melamine and urea-formaldehyde adducts, the equivalent ratio of polyester resin to cross linking agent being of from 0.8 to 4.0;
- and
- (c) a suitable cross linking catalyst;
- (ii) at least one anti-corrosive chromate pigment, the amount of anti-corrosive pigment being at least 50 weight percent of all pigments in the composition, and the pigment volume concentration being 90 to 99% of the critical pigment volume concentration;
- and
- (iii) at least one solvent.
5 more elements
Dependencies are inferred from the claim text.