Aluminum complexes useful for cross-linking coating compositions

Abstract

Aluminum complexes useful as cross-linking agents for coating compositions, especially high solids compositions containing an alkyd resin binder, are made by reacting a volatile oxime with a product of reaction of (1) an aluminum alcoholate or phenolate, (2) a carboxylic acid and/or β-diketo compound, and (3) optionally water.

We claim: 
     
       1. A coating composition comprising an air-drying alkyd resin binder and a cross-linking agent consisting of an aluminum complex, said aluminum complex formed by a process comprising the steps of: (a) forming an aluminum product having aluminum coordination sites by reacting (i) an aluminum alcoholate or phenolate with (ii) an enolizable β-diketo compound or a carboxylic acid; and   (b) forming the aluminum complex by reacting said aluminum product with a volatile ketoxime or aldoxime compound, the proportion of said volatile ketoxime or aldoxime compound being sufficient to complex all of the aluminum coordination sites in said aluminum product.   
     
     
       2. An aluminum complex formed by a process comprising the steps of: (a) forming an aluminum product having aluminum coordination sites by reacting (i) an aluminum alcoholate or phenolate with (ii) an enolizable β-diketo compound or a carboxylic acid; and   (b) forming the aluminum complex by reacting said aluminum product with a volatile ketoxime or aldoxime compound, the proportion of said volatile ketoxime or aldoxime compound being sufficient to complex all of the aluminum coordination sites in said aluminum product.   
     
     
       3. An aluminum complex according to claim 2, wherein said reaction in step (a) is conducted in the presence of water. 
     
     
       4. An aluminum complex according to claim 2, wherein said volatile ketoxime or aldoxime compound has from 2 to 6 carbon atoms. 
     
     
       5. An aluminum complex according to claim 4, wherein said volatile ketoxime or aldoxime compound is methlethylketoxime.