| abstract |
A polyester composition has a number average molecular weight Mn of between about 500 and about 1000, a weight average molecular weight Mw of between about 600 and about 2000, a polydispersity below about 2, preferably below about 1.8, hydroxyl functionality between 2 and 3, a hydroxyl value of between about 160 and about 260, and an acid number below about 10. Less than about 5% of the OH groups of the polyester are pendent, the rest being terminal. Between about 10 and about 50 wt % of the monomers used to form the polyester composition are anhydrides having the formula: <IMAGE> (I) where R1 is a non-aromatic, saturated or unsaturated hydrocarbon chain having between 6 and 30 carbon atoms, R2 is hydrogen or a non-aromatic saturated or unsaturated hydrocarbon having between 1 and 8 carbon atoms, and R1 and R2 have, in total, between 8 and 30 carbon atoms. The polyester in conjunction with a hydroxyl-reactive curative provides a coating composition. |