COATING COMPOSITIONS WITH IMPROVED ADHESION TO CONTAINERS

• US 20120301645A1
• Filed: 05/23/2011
• Published: 11/29/2012
• Est. Priority Date: 05/23/2011
• Status: Active Grant

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Moussa, Youssef, Knotts, Claudia, List, Michael
• Granted Patent: US 9,670,378 B2
• Time in Patent Office: Days
• US Class Current: 428/35.7
• CPC Class Codes: C08G 59/1422 containing phosphorus
• CPC Class Codes: C08G 59/304 containing phosphorus
• CPC Class Codes: C08K 5/524 Esters of phosphorous acids, e.g. of H3PO3
• CPC Class Codes: C08L 63/00 Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• CPC Class Codes: C09D 133/02 Homopolymers or copolymers of acids; Metal or ammonium salts thereof
• CPC Class Codes: C09D 133/064 containing anhydride, COOH or COOM groups, with M being metal or onium-cation
• CPC Class Codes: C09D 143/02 Homopolymers or copolymers of monomers containing phosphorus
• CPC Class Codes: C09D 167/00 Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain based on polyester-amides C09D177/12; based on polyester-imides C09D179/08; Coating compositions based on derivatives of such polymers
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]

Abstract

A coating composition comprising a resinous binder and up to 10 percent by weight of the reaction product of (i) a phosphorus acid, and (ii) a polyglycidyl ether of cyclohexane dimethanol. The compositions are useful for coating containers of all sorts, such as food and beverage containers, and the reaction product provides enhanced adhesion of the coating to the substrate. The compositions can be formulated to be substantially free of bisphenol A (BPA) and derivatives thereof such as bisphenol A diglycidyl ether (BADGE).

Claims

1. A coating composition comprising:

(a) a resinous binder,

(b) up to 10 percent by weight based on weight of resin solids in the coating composition of a reaction product comprising;

(i) a phosphorus acid, and

(ii) polyglycidyl ether of cyclohexane dimethanol.

2. The coating composition of claim 1 in which the resinous binder comprises an acrylic polymer and/or a polyester polymer.

3. The coating composition of claim 1 further comprising a crosslinking agent.

4. The coating composition of claim 3 in which the crosslinking agent comprises an aminoplast and/or a phenolplast.

5. The coating composition of claim 1 in which the phosphorus acid comprises a phosphoric acid.

6. The coating composition of claim 1 in which the phosphorus acid is used in amounts of 0.2 to 0.5 equivalents per equivalent of epoxy, that is, 0.2 to 0.5 P—

OH for each oxirane group.

7. The coating composition of claim 1 wherein (b) is present in amounts of 0.5 to 5 percent by weight.

11. A coated article comprising:

(a) a substrate, and

(b) a coating deposited on at least a portion thereon from the composition of claim 1.

12. The coated article of claim 11 in which the substrate is a container.

13. The coated article of claim 12 in which the substrate is a can for food or beverage.

14. The coated article of claim 11 in which the coating is deposited on the exterior of the container.

15. The coated article of claim 14 in which the coating is a cured thermoset composition.

16. The coating composition of claim 1, which is substantially free of bisphenol A and derivatives thereof.

17. The coating composition of claim 1, which is free of bisphenol A and derivatives thereof.

8. A coating composition comprising:

(a) a resinous binder comprising;

(i) an acrylic polymer having reactive functional groups,

(ii) an aminoplast crosslinker having functional groups reactive with the functional groups of (i),

(b) 0.5 to 5 percent by weight based on weight of resin solids in the coating composition of a reaction product comprising;

(i) phosphoric acid, and

(ii) cyclohexane dimethanol diglycidyl ether.

9. The coating composition of claim 8 in which the acrylic polymer is present in amounts of 40 to 90 percent by weight;

the crosslinking agent is present in amounts of 5 to 50 percent by weight;

the percentages by weight being based on total weight of resin solids in the composition.

10. The coating composition of claim 8 in which the phosphoric acid is used in amounts of 0.2 to 0.5 equivalents per equivalent of oxirane.