Polymer having unsaturated cycloaliphatic functionality and coating compositions therefrom
View Patent ↗A polymer is provided that preferably includes at least one unsaturated cycloaliphatic group. In one embodiment, the polymer is combined with an optional crosslinker and an optional carrier to form a coating composition suitable for use in coating articles such as packaging articles. In one embodiment, the polymer has at least one unsaturated cycloaliphatic group that is at least bicyclic.
1. A method, comprising:
providing a coating composition comprising an aromatic polyester polymer having a Tg of at least 0° C. and a backbone or pendant unsaturated at least bicyclic group with a double bond located between carbon atoms of a ring;
applying the coating composition on a metal substrate prior to, or after, forming the metal substrate into a food or beverage can or a portion thereof.
2. The method of claim 1 , wherein the coating composition includes less than 2 weight percent of water, if any.
3. The method of claim 1 , wherein the coating composition includes at least 20 weight percent of water.
4. The method of claim 1 , wherein the coating composition is applied on the metal substrate prior to forming the metal substrate into a food or beverage can or a portion thereof, and wherein, after curing the coating composition, the coated metal substrate is formed into a food or beverage can or a portion thereof.
5. The method of claim 1 , wherein the unsaturated at least bicyclic group was incorporated into the aromatic polyester polymer using nadic acid, methyl-nadic acid, or an anhydride or derivative thereof.
6. The method of claim 5 , wherein the aromatic polyester polymer includes a plurality of the unsaturated at least bicyclic groups that constitute at least about 5 weight percent of the aromatic polyester polymer.
7. The method of claim 1 , wherein the aromatic polyester polymer comprises a reaction product of ingredients including one or more of maleic acid or anhydride, and wherein a structural unit derived from maleic acid or anhydride includes the unsaturated at least bicyclic group.
8. The method of claim 7 , wherein the structural unit is a Diels-Alder reaction product.
9. The method of claim 1 , wherein the aromatic polyester polymer includes a plurality of the unsaturated at least bicyclic groups that constitute at least about 5 weight percent of the aromatic polyester polymer.
10. The method of claim 9 , wherein the aromatic polyester polymer includes at least 5 weight percent of aromatic groups.
11. The method of claim 9 , wherein the coating composition includes an amino crosslinker, an anhydride-based crosslinker, a blocked isocyanate crosslinker, a phenolic crosslinker, an epoxy-functional crosslinker, or a mixture thereof.
12. The method of claim 9 , wherein the aromatic polyester polymer includes less than 3 weight percent of fatty acids and oils, based on the total non-volatile weight of ingredients used to make the aromatic polyester polymer.
13. The method of claim 9 , wherein the aromatic polyester polymer includes less than 1 weight percent of long-chain hydrocarbons including eight or more carbon atoms, based on the total non-volatile weight of ingredients used to make the aromatic polyester polymer.
14. The method of claim 9 , wherein the aromatic polyester polymer is formed from reactants including a dianhydride.
15. The method of claim 9 , wherein the dianhydride comprises pyromellitic dianhydride.
16. The method of claim 1 , wherein the aromatic polyester polymer has a Tg of at least 25° C. and less than 150° C.
17. The method of claim 16 , wherein the coating compositions includes a resole phenolic crosslinker.
18. A method, comprising:
providing a coating composition comprising:
an aromatic polyester polymer having a number average molecular weight of from 3,000 to 15,000 that includes:
at least 10 weight percent of aromatic groups, and
at least 5 weight percent of backbone or pendant unsaturated at least bicyclic groups having a carbon-carbon double bond located between carbon atoms of a ring;
a crosslinker comprising an amino crosslinker, an anhydride-based crosslinker, a blocked isocyanate crosslinker, a phenolic crosslinker, an epoxy-functional crosslinker, or a mixture thereof; and
a liquid carrier; and
applying the coating composition on a metal substrate prior to, or after, forming the metal substrate into a food or beverage can or a portion thereof.
19. A method, comprising:
providing a metal substrate having a coating present on at least a portion of the substrate, wherein the coating was formed from a coating composition including at least 50 weight percent, based on the total nonvolatile weight of the coating composition, of an aromatic polyester polymer that includes (i) a backbone or pendant unsaturated at least bicyclic group with a double bond located between carbon atoms of a ring and (ii) at least 5 weight percent of aromatic groups; and
forming the metal substrate into a food or beverage can or a portion thereof.
20. The method of claim 19 , wherein the aromatic polyester polymer includes at least 20 weight percent of aromatic groups.
21. The method of claim 19 , wherein the coating composition includes, based on nonvolatile weight, from 5 to 50 weight percent of one or more crosslinkers.
22. The method of claim 19 , wherein the coating composition includes, based on nonvolatile weight, from 5 to 50 weight percent of a resole phenolic crosslinker.
23. The method of claim 19 , wherein the aromatic polyester polymer includes less than 3 weight percent of fatty acids and oils, based on the total non-volatile weight of ingredients used to make the aromatic polyester polymer.
24. The method of claim 19 , wherein the aromatic polyester polymer includes less than 1 weight percent of long-chain hydrocarbons including eight or more carbon atoms, based on the total non-volatile weight of ingredients used to make the aromatic polyester polymer.
25. The method of claim 19 , wherein the food or beverage can or a portion thereof comprises a sidewall of a three-piece food can and the coating comprises an interior coating.
26. The method of claim 19 , wherein the coating is substantially free of bound BPA and aromatic glycidyl ether compounds.
27. A food or beverage can or a portion thereof produced by the method of claim 19 .
28. The food or beverage can of claim 27 , wherein the coating is an interior coating and the food or beverage can contains a food or beverage product.