Carbamate-functional resins and their use in high solids coating compositions

A carbamate functional resin, made by a process comprising the steps of:

• reacting a core compound having three or more primary or secondary hydroxyl groups with a carboxylic anhydride to form a first intermediate containing at least one carboxylic functional group and optionally containing primary hydroxyl groups;
• reacting the first intermediate with a compound containing one epoxide group to form a second intermediate containing at least one secondary hydroxyl group;
• and
• reacting the second intermediate with a carbamic compound to convert some or all of the secondary and optional primary hydroxyl groups to a carbamate functional group.

A carbamate-functional resin comprising

• a hyperbranched or star polyol core;
• a first chain extension based on a polycarboxylic acid or anhydride;
• a second chain extension based on an epoxide-containing compound;
• and
• carbamate functional groups on the core, the second chain extension or both.