Thermosetting compositions containing carbamate-functional polylmers prepared using atom transfer radical polymerization

A method of coating a substrate comprising:

• (a) applying a thermosetting composition to the substrate;
• (b) coalescing the thermosetting composition over the substrate in the form of a substantially continuous film;
• and
• (c) curing the thermosetting composition, wherein the thermosetting composition comprises:
• (i) a crosslinking agent having at least two functional groups that are reactive with carbamates;
• and
• (ii) a non-gelled, carbamate functional polymer prepared by atom transfer radical polymerization, in the presence of an initiator having at least one radically transferable group, and wherein the polymer contains at least one of the following polymer chain structures:
• —{(M)p—(G)q}x—
• or
• —{(G)q—(M)p}x—
• wherein M is a residue, that is free of carbamate functionality, of at least one ethylenically unsaturated radically polymerizable monomer;
• G is a residue, that has pendant carbamate functionality of the structure:
• of at least one ethylenically unsaturated radically polymerizable monomer wherein R is hydrogen or a monovalent alkyl group having from 1 to 10 carbon atoms or aryl group having from 6 to 10 carbon atoms;
• p and q represent average numbers of residues occurring in a block of residues in each polymer chain structure;
• and p, q, and x are each independently selected for each structure such that said carbamate functional polymer has a number average molecular weight of at least 250.

A multi-component composite coating composition comprising a base coat deposited from a pigmented film-forming composition and a transparent top coat applied over the base coat wherein the transparent top coat is deposited from a clear film-forming composition and is a thermosetting composition comprising:

• (a) a crosslinking agent having at least two functional groups that are reactive with carbamates;
• and
• (b) a non-gelled, carbamate functional polymer prepared by atom transfer radical polymerization, in the presence of an initiator having at least one radically transferable group, and wherein the polymer contains at least one of the following polymer chain structures:
• —{(M)p—(G)q}x—
• or
• —{(G)q—(M)p}x—
• wherein M is a residue, that is free of carbamate functionality, of at least one ethylenically unsaturated radically polymerizable monomer;
• G is a residue, that has pendant carbamate functionality of the structure:
• of at least one ethylenically unsaturated radically polymerizable monomer wherein R is hydrogen or a monovalent alkyl group having from 1 to 10 carbon atoms or aryl group having from 6 to 10 carbon atoms;
• p and q represent average numbers of residues occurring in a block of residues in each polymer chain structure;
• and p, q, and x are each independently selected for each structure such that said carbamate functional polymer has a number average molecular weight of at least 250.