Patent ID: 7396893

Claim:
A solid silicone polyester suitable for use as a powder coating, said silicone polyester being aliphatic with hydroxyl functionality and prepared by reacting a silicone with a polyester, the resulting silicone polyester having a Tg between 35° C. and 75° C., wherein the polyester and the silicone being reacted to form the silicone polyester each have a Tg greater than 30° C.; wherein the silicone comprises a silanol-functional organopolysiloxane resin which contains at least one or more of the repeating units having the formulae: R a 1 ⁢ R b 2 ⁢ SiO 1 2 ⁡ ( M ⁢ ⁢ units ) R a 1 ⁢ R b 2 ⁢ SiO 2 2 ⁡ ( D ⁢ ⁢ units ) R a 1 ⁢ R b 2 ⁢ SiO 3 2 ⁡ ( T ⁢ ⁢ units ) SiO 4 2 ⁡ ( Q ⁢ ⁢ units ) wherein R 1 and R 2 are independently a C 1-20 hydrocarbon, optionally interspersed with a heteroatom linking group such as, but not limited to, a is an integer of 0, 1, 2 or 3; b is an integer of 0, 1, 2 or 3; and in M units, a+b+c=3; in D units, a+b+c=2; in T units, a+b+c=1; and wherein the silicone polyester comprises 28-33 weight % silicone and 67-72 weight % polyester, and has a hydroxy equivalent of 187-280 g/mole OH.