摘要 |
Hydroxy functional polyester graft copolymers are provided. The copolymer is crosslinkable by hydroxy-reactive crosslinking agent and, in particular, is suitable for use in thermosetting coating compositions adapted to form a flexible cured coating over a variety of substrates, such as metal and plastic. The copolymer has a number average molecular weight between about 1300 and about 15,000, has a hydroxyl number between about 30 and about 300, and is the reaction product of carbon-carbon double bond-reactive monoethylenically unsaturated monomer with hydroxy functional carbon-carbon double bond-bearing branched polyester macromer. The macromer is the reaction product of (i) hydroxy functional polyester reactant containing 0-10 urethane linkages per molecule with (ii) silane compound having the general chemical formula: <IMAGE> wherein X is an organic group or (-Si-O-)n, n being 1-50, and X' is independently an organic group, hydroxy-reactive functionality, or an organic group comprising hydroxy-reactive functionality, at least one X' comprising hydroxy-reactive functionality.
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