Polyamideimide compositions having multifunctional core structures

Abstract

Polyamideimide coating compositions, including polyamideimide coating compositions suitable for magnet wire applications are described. Processes for preparing coating compositions, for coating articles such as magnet wire, and for curing coating compositions are also described.

1 . A polyamideimide coating composition comprising a solvent, and the reaction products of a mixture of:
 component (a) selected from the group consisting of one or more acid anhydrides of triacids, and combinations thereof;   component (b) one or more diisocyanates; and   component (c) one or more multifunctional compounds.   
   
   
       2 . The coating composition of  claim 1  wherein component (a) comprises trimellitic anhydride. 
   
   
       3 . The coating composition of  claim 1  wherein component (c) comprises a multifunctional compound comprising a free carboxylic acid. 
   
   
       4 . The coating composition of  claim 1  wherein component (c) comprises a multifunctional compound comprising an aromatic nitrogen having a pKa of less than about 4. 
   
   
       5 . The coating composition of  claim 1  wherein component (c) comprises at least one multifunctional compound selected from the group consisting of isocyanuric acid, butane tetracarboxylic acid, citric acid, polyacrylic acid, polymethacrylic acid, and poly(methyl methacrylate-co-methacrylic acid), benzoic tetracarboxylic acid, phenolic resin, dicarboxy-terminated poly(acrylonitrile-co-butadiene-co-acrylic acid), poly(acrylamide-co-acry-lic acid 10%), and polyamide-amic acid, and combinations thereof. 
   
   
       6 . The coating composition of  claim 1  wherein component (c) comprises at least one multifunctional compound selected from the group consisting of butane tetracarboxylic acid, citric acid, polyacrylic acid, polymethacrylic acid, and poly(methyl methacrylate-co-methacrylic acid), benzoic tetracarboxylic acid, phenolic resin, dicarboxy-terminated poly(acrylonitrile-co-butadiene-co-acrylic acid), poly(acrylamide-co-acry-lic acid 10%), polyamide-amic acid, and combinations thereof. 
   
   
       7 . The coating composition of  claim 1  wherein component (c) comprises at least one multifunctional compound selected from the group consisting of butane tetracarboxylic acid and citric acid. 
   
   
       8 . The coating composition of  claim 1  further comprising component (d) one or more fillers. 
   
   
       9 . The coating composition of  claim 1  further comprising component (e) one or more nanofillers. 
   
   
       10 . The coating composition of  claim 1  further comprising component (f) one or more fluoropolymer fillers. 
   
   
       11 . The coating composition of  claim 1  further comprising component (g) selected from the group consisting of one or more diacids, one or more dianhydrides of tetraacids, and combinations thereof. 
   
   
       12 . The coating composition of  claim 11  wherein component (g) comprises a compound selected from the group consisting of isophthalic acid, adipic acid, a combination of isophthalic acid and adipic acid, and anhydrides thereof. 
   
   
       13 . The coating composition of  claim 1  wherein the solvent includes methylpyrrolidinone. 
   
   
       14 . The coating composition of  claim 1  wherein the reaction products result from a two-stage reaction comprising the steps of (i) heating the mixture to a first temperature for a predetermined period of time; and (ii) heating the mixture to a second temperature for a predetermined period of time, where the second temperature is higher than the first temperature. 
   
   
       15 . A magnet wire comprising a conductive element, and a polyamideimide coating therefor, said polyamideimide coating comprising a cured residue of the coating composition of  claim 1 . 
   
   
       16 . The magnet wire of  claim 15  further comprising a base coat, where said base coat in positioned between the conducting element and the polyamideimide coating. 
   
   
       17 . The magnet wire of  claim 16  wherein the base coat includes a polyester. 
   
   
       18 . The magnet wire of  claim 16  wherein the base coat includes a polymer of trishydroxyethyl isocyanurate. 
   
   
       19 - 27 . (canceled)