Quantcast

Can and coil coating resins

Imported: 23 Feb '17 | Published: 02 Jul '02

Albert Heyenk, Johannes Wilhelmus Besamusca

USPTO - Utility Patents

Abstract

The invention relates to a can or coil coating resin system. The system contains a mixture of at least 2 polymers wherein at least one polymer has a glass transition temperature greater than 45° C. and wherein the polymers are soluble in organic solvents. The polymer with the glass transition temperature of greater than 45° C. is preferably an amorphous polyester resin. The second polymer may be a resin with a dry solids content between 30% and 100% and a Tg of less than 40° C.

Claims

1. A coating resin comprising a mixture of at least two polyesters and a solvent wherein at least one polyester has a glass transition temperature greater than 45° C. and at least one polyester has a Tg of less than 40° C., and wherein the polyesters are soluble in organic solvents, said polyesters are formed from reaction components consisting of an acid component and at least one polyalcohol component, wherein said acid component is selected from the group consisting of phthalic anhydride, isophthalic acid, terephthalic acid, dimethylterephthalate ester, adipic acid, sebacic acid, hexahydroterephthalic acid, decane dicarboxylic acid, 5,6-butylisophthalic acid, tetrahydrophthalic anhydride, succinic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, and mixtures thereof.

2. A coating resin system according to claim 1, wherein the polyester with the glass transition temperature greater than 45° C. is an amorphous polyester.

3. A can or coil coating composition comprising a coating resin system according to claim 1, a crosslinker and optionally at least one additive.

4. A composition according to claim 3, wherein the crosslinker is a compound containing epoxy groups, a compound containing amino groups or a compound containing isocyanate groups.

5. A substrate that is at least partially coated wherein the coating is obtained from a composition according to claim 3.

6. A coating resin as claimed in claim 1, wherein said acid component is selected from the group consisting of phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid and mixtures thereof.

7. The coating resin according to claim 1, which comprises said at least one polyester having a Tg of less than 40° C. in an amount of at least 50 wt. %.

8. The coating resin composition according to claim 7, wherein the said at least one polyester having a Tg of less than 40° C., has a Tg of less than 10° C.