Thermosetting compositions containing epoxy-functional polymers prepared using atom transfer radical

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 liquid thermosetting composition comprising:

• (a) a crosslinking agent having at least two functional groups that are reactive with epoxide groups;
• and
• (b) a non-gelled, epoxy functional block copolymer prepared by atom transfer radical polymerization, in the presence of an initiator having at least one radically transferable group, and wherein the polymer contains the following polymer chain structure:
• wherein M is a residue, that is free of epoxy functionality, of at least one ethylenically unsaturated radically polymerizable monomer;
• G is a residue, that has epoxy functionality, of at least one ethylenically unsaturated radically polymerizable monomer;
• φ is a residue from the initiator, free from the radically transferable group, selected from the group consisting of linear or branched aliphatic compounds, cycloaliphatic compounds, heterocyclic compounds, sulfonyl compounds, sulfenyl compounds, esters of carboxylic acids, polymeric compounds and mixtures thereof;
• T is or is derived from the radically transferable group and is selected from the group consisting of halide and a dehalogenation reaction product of a limited radically polymerizable ethylenically unsaturated compound;
• z represents the number of radically transferable groups;
• r, p and q represent average numbers of residues occurring in a block of residues in each polymer chain structure;
• z, r, p, q and x are each individually selected for each structure such that said epoxy functional block copolymer has a number average molecular weight of at least 250;
• p is an integer of from 1 to 100;
• q is an integer of from 1 to 15;
• and x is an integer of from 1 to 10;
• r is an integer from 3 to 100;
• z is at least 1;
• and wherein the epoxy functional polymer has an epoxy equivalent weight of from 128 to 10,000 grams/equivalent.