Coating compositions including a polyisocyanate chain extended NH functional prepolymer

A method for coating of a metallic or plastic substrate, the method comprising the steps of:

• a) applying a coating composition to at least a portion of a metallic or plastic substrate to be coated, wherein the coating composition comprises a polyisocyanate chain extended NH functional pre-polymer, wherein the polyisocyanate chain extended NH functional pre-polymer
• 1) is free of isocyanate groups,
• 2) has an NH equivalent weight of from 300 to 5,000 g, and
• 3) consists of a reaction product that is made by reacting a reaction mixture consisting of:
• (c1) at least one polyisocyanate selected from the group consisting of:
• 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (IPDI), 1,5-pentane diisocyanate, 4,4′-diisocyanatocyclohexylmethane, hexamethylene diisocyanate (HDI), 1,1′,6,6′-tetramethyl-hexamethylene diisocyanate, p- or m-tetramethylxylylene diisocyanate, 2,2′,5 trimethylhexane diisocyanate, aromatic polyisocyanates, toluenediisocyanate, diphenylmethanediisocyanate, and mixtures thereof, and
• (c2) a NH functional pre-polymer, and
• (c3) optional solvents and reaction catalysts, wherein the NH functional pre-polymer consists of a reaction product that is made by reacting a reaction mixture consisting of:
• (c2.1) a compound having at least one primary amine group that is an arylalkyl diamine selected from the group consisting of:
• 1,3- and 1,4-cyclohexane diamine, 5-amino-1,3,3-trimethyl-cyclohexanemethanamine (IPDA), norbornyldiamine, 2,4- and 2,6-hexahydrotoluylene diamine, 2,4′- and 4,4′-diamino-dicyclohexyl methane and 3,3′-dialkyl-4, 4′-diaminodicyclohexylmethanes, 3, 3′-dimethyl-4, 4′-diaminodicyclohexyl methane and 3,3′-diethyl-4,4′-diaminodicyclohexylmethane, 1,3- and 1,4 xylylenediamine, tetramethyl xylylenediamine, and mixtures thereof,
• (c2.2) at least one dialkyl maleate selected from the group consisting of:
• dimethyl maleate, diethyl maleate, di-n-butyl maleate, di-iso-butyl maleate, di-tert-butyl maleate, diamyl maleate, di-n-octyl maleate, dilauryl maleate, and mixtures thereof,
• (c2.3) at least one acrylate- and/or methacrylate-containing compound selected from the group consisting of:
• methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, isobutyl(meth)acrylate, sec.-butyl(meth)acrylate, tert.-butyl(meth)acrylate, cyclohexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, isooctyl(meth)acrylate, isodecyl(meth)acrylate, lauryl(meth)acrylate, stearyl(meth)acrylate, isobornyl(meth)acrylate, tert-butylcyclohexyl(meth)acrylate, and
• (c2.4) optional solvents and reaction catalysts, wherein a molar ratio of the at least one dialkyl maleate to the at least one acrylate- and/or methacrylate-containing compound is from 1:10 to 10:1, and
• b) curing the coating composition applied in step a).

A coating composition comprising a polyisocyanate chain extended NH functional pre-polymer, wherein the polyisocyanate chain extended NH functional pre-polymer is free of isocyanate groups, has an NH equivalent weight of from 300 to 5,000 g, and consists of a reaction product formed from reactants consisting of:

• isophoronediisocyanate and a NH functional pre-polymer,
• wherein the NH functional pre-polymer consists of a biaspartate consisting of a reaction product formed from reactants consisting of:
• isophoronediamine, diethylmaleate, and methyl(meth)acrylate, and
• wherein a molar ratio of the diethylmaleate to the methyl(meth)acrylate in the NH functional pre-polymer is from 1:10 to 10:1.