High functionality polyesters and coatings comprising the same

Patent metadata

Field	Value
Publication number	US-10450398-B2
Application number	US-201715611114-A
Country	US
Kind code	B2
Filing date	Jun 1, 2017
Priority date	Apr 1, 2010
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

A polyester prepared by free radical polymerization of an unsaturated polyester prepolymer, wherein the polymerization occurs primarily by reaction of the unsaturation of said prepolymer is disclosed. Coatings comprising the same are also disclosed, as are substrates coated at least in part with such coating.

First claim

The invention claimed is:

1. A process for preparing an ungelled crosslinkable polyester resin comprising:
(a) reacting a polycarboxylic acid with a polyol to form an unsaturated polyester prepolymer in which the unsaturation is along the backbone of the unsaturated polyester prepolymer and wherein the unsaturated polyester prepolymer has terminal acid and/or hydroxyl functional groups, a hydroxyl value ranging from 2 to 500 mg KOH/gm and/or an acid value ranging from 1 to 400 mg KOH/gm; and
(b) subjecting the unsaturated polyester prepolymer to thermally induced free radical polymerization via the points of unsaturation along the unsaturated polyester prepolymer backbone to form the ungelled crosslinkable polyester resin that has a higher weight average molecular weight than the unsaturated polyester prepolymer such that the weight average molecular weight ratio of the ungelled crosslinkable polyester resin to the unsaturated polyester prepolymer is at least 1.2 and the hydroxyl value and the acid value of the ungelled crosslinkable polyester resin is in the same range as those of the prepolymer.

2. The process of claim 1 in which the unsaturated polyester prepolymer comprises one or more unsaturated polyester prepolymers.

3. The process of claim 2 in which the unsaturated polyester prepolymer comprises a mixture of different unsaturated polyester prepolymers.

4. The process of claim 1 in which the polycarboxylic acid is unsaturated.

5. The process of claim 4 in which the polycarboxylic acid comprises maleic, fumaric and/or itaconic acid and/or the esters and/or the anhydrides thereof.

6. The process of claim 1 wherein the number average functionality of unsaturation is from 0.1 to 5.0.

7. The process of claim 1 wherein the thermally induced free radical polymerization conditions are by heating the unsaturated polyester prepolymer in a diluent comprising an organic solvent and/or water to a temperature of 50 to 150° C. in the presence of a free radical initiator.

8. The process of claim 1 in which the unsaturated polyester prepolymer component has a number average molecular weight of 150 to 5000.

9. The process of claim 1 in which the ungelled crosslinkable polyester resin has a weight average molecular weight of at least 15,000 and a functionality of at least 100 mg KOH/gm.

10. The process of claim 1 in which the ungelled crosslinkable polyester resin has a weight average molecular weight of 1000-7,000,000.

Assignees

• Ppg Ind Ohio Inc

Inventors

• Lock Kam Lun
• Woods Richard
• Masters Nigel Francis

Classifications

• Y10T428/1355

  Elemental metal containing [e.g., substrate, foil, film, coating, etc.] · CPC title

• Y10T428/31681

  Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.] · CPC title

• C08F299/045 Primary

  Peroxy-compounds · CPC title

• C08L2205/02

  containing two or more polymers of the same C08L -group · CPC title

• B65D25/14

  Linings or internal coatings (of containers made by folding or erecting blanks made of paper B65D5/56 {; linings for domestic water storage heaters F24H1/183}) · CPC title