Thermosetting coating compositions
AssigneeEastman Kodak Company
InventorThauming Kuo
Life of this patent
Estimating the term…
Abstract
Provided are enhanced phenolic-functional polyesters which are useful in enamel compositions. The enamel compositions provide coatings which exhibit superior hardness, impact resistance, acid resistance, and weatherability heretofore unachievable with other polyester-based coatings.
Claims9
A curable polyester having a number average molecular weight of about 1500 to about 3500 and a weight average molecular weight of about 10,000 to about 70,000, comprising:
- (a) about 20 to 36 mole percent of diol residues, based on the total moles of (a), (b), (c), (d), and (e);
- (b) about 10 to about 21 mole percent of triol residues, based on the total moles of (a), (b), (c), (d), and (e);
- (c) about 5 to about 18 mole percent, based on the total moles of (a), (b), (c), (d), and (e), of residues of an aliphatic diacid,
- (d) about 25 to about 35 mole percent of aromatic dicarboxylic acid residues based on the total moles of (a), (b), (c), (d), and (e);
- (e) about 12 to about 20 mole percent, based on the total moles of (a), (b), (c), (d), and (e), of hydroxy acid residues selected from residues of ##STR7## wherein substantially all of said hydroxy acid residues are at the ends of said curable polyester.
A process for preparing a curable polyester having a number average molecular weight of about 1500 to about 3500 and a weight average molecular weight of about 10,000 to about 70,000, comprising
- (a) about 20 to 36 mole percent of diol residues, based on the total moles of (a), (b), (c), (d), and (e);
- (b) about 10 to about 21 mole percent of triol residues, based on the total moles of (a), (b), (c), (d), and (e);
- (c) about 5 to about 18 mole percent, based on the total moles of (a), (b), (c), (d), and (e), of residues of an aliphatic diacid,
- (d) about 25 to about 35 mole percent of aromatic dicarboxylic acid residues based on the total moles of (a), (b), (c), (d), and (e);
- (e) about 12 to about 20 mole percent, based on the total moles of (a), (b), (c), (d), and (e), of hydroxy acid residues selected from residues of ##STR13## wherein substantially all of said hydroxy acid residues are at the ends of said curable polyester;
- which comprises combining component (b) triol with component (e) in the presence of a condensation catalyst, followed by heating to a temperature sufficient to induce condensation, followed by addition of components (a), (d) and optionally (c), followed by continued heating until said condensation is substantially complete.
Dependencies are inferred from the claim text.