Coating compositions incorporating ingredients having secondary amine, hydroxyl and isocyanate functionality
The present invention provides coating compositions with excellent curing performance. Curing can occur very rapidly for excellent cycle time, yet with minimal (if any) foaming. A preferred catalyst system helps to provide excellent initial and follow through cure through the entirety of the coating thickness, even with respect to in-mold coating (IMC) applications. Preferred aspects of the invention provide a composition having zero, or nearly zero, emissions of volatile organic compounds (VOC) when applied and cured.
1. A coating composition derived from ingredients, comprising:
a) a secondary amine component;
b) a 100% solids polyisocyanate component; and
c) a catalyst system, comprising:
(i) a first catalyst comprising catalytically active aluminum; and
(ii) a second catalyst comprising a catalytically active zirconium,
wherein the first catalyst and the second catalyst are present in a ratio of 1:10 to 10:1 parts by weight, and wherein the composition is applied to a mold surface as an in-mold coating.
2. A coating composition according to claim 1 , further comprising d) a polyol component.
3. The coating composition of claim 1 , wherein
the secondary amine component comprises at least one compound according to the formula
X 1 —[NH—Z 1 —(COOR 1 ) m ] n
wherein each R 1 independently is a monovalent moiety other than H that is substantially inert with respect to being co-reactive with NCO functionality at a temperature of 150° C. or less, X 1 is a moiety having a valency of n that is substantially inert with respect to being co-reactive with NCO functionality at a temperature of at least 150° C. or less, Z 1 is a single bond or linking group with a valence of m+1; m is 1 to 20; and n is at least 1 and no greater than 20.
4. A cured coating obtained from a composition of claim 1 .
5. A coating composition according to claim 1 , further comprising an air release additive.
6. A coating composition according to claim 1 , further comprising a thixotrope.
7. The composition of claim 1 , wherein the first and second catalysts are present in a ratio of 1:1.5 to 1:2.
8. The composition of claim 1 , wherein the first catalyst is an aluminum chelate in 2, 4-pentanedione, and the second catalyst is a zirconium chelate in 2,4-pentanedione.