Latex polymers made using metallic-base-neutralized surfactant and blush-resistant coating compositions containing such polymers

Patent metadata

Field	Value
Publication number	US-2020385601-A1
Application number	US-201616065294-A
Country	US
Kind code	A1
Filing date	Dec 22, 2016
Priority date	Dec 23, 2015
Publication date	Dec 10, 2020
Grant date	—

Abstract

An aqueous coating composition is provided that is preferably substantially free of bisphenol A. The coating composition is preferably a latex-based coating composition that includes a latex polymer formed from ingredients including an anionic and/or zwitterionic surfactant that includes one or more acid groups neutralized with a metallic base. The coating composition is useful in coating metal substrates such as, for example, interior and/or exterior surfaces of food or beverage containers.

First claim

1 . A water-based inside spray food or beverage can coating composition, wherein the coating composition comprises a latex polymer formed by polymerizing an ethylenically unsaturated monomer component in an aqueous media in the presence of a first surfactant, and wherein the first surfactant comprises an anionic surfactant, a zwitterionic surfactant, or a mixture thereof that includes an acid group neutralized with a metallic base;
wherein the coating composition, when spray applied via airless spray application to an interior of an aluminum beverage can at an average cured coating thickness of 4 grams per square meter and cured in an oven under conditions that obtain a peak metal temperature of 193° C. for 45 seconds, passes less than 3.5 mA of current when tested pursuant to the Metal Exposure After Drop Damage test disclosed herein.

2 . The coating composition of claim 1 , wherein the coating composition includes at least 50% by weight of the latex polymer, based on the total weight of resin solids in the coating composition.

3 . The coating composition of claim 1 , wherein the coating composition includes at least 90% by weight of the latex polymer, based on the total weight of resin solids in the coating composition.

4 . The coating composition of claim 1 , wherein the coating composition includes a crosslinker, and wherein the crosslinker is selected from one or more of a phenolic crosslinker, a blocked isocyanate crosslinker, or an aminoplast crosslinker.

5 . The coating composition of claim 1 , wherein the coating composition includes a crosslinker, and wherein: (i) the crosslinker comprises a carboxyl-reactive crosslinker and (ii) the latex polymer includes acid groups.

6 . The coating composition of claim 1 , wherein the coating composition is substantially free of bisphenol A, bisphenol F, and Bisphenol S, and wherein the coating composition is substantially free of halogenated monomers.

7 . The coating composition of claim 1 , wherein the coating composition is substantially free of each of acrylamide-type monomers and oxirane-functional monomers.

8 . The coating composition of claim 1 , wherein the coating composition, when spray applied via airless spray application to an interior of an aluminum beverage can at an average cured coating thickness of 4 grams per square meter and cured in an oven under conditions that obtain a peak metal temperature of 193° C. for 45 seconds, does not exhibit any whitening visible to the unaided human eye after retort in deionized water for 30 minutes at 121° C.

9 . The coating composition of claim 1 , wherein the coating composition, when spray applied via airless spray application to an interior of an aluminum beverage can at an average cured coating thickness of 4 grams per square meter and cured in an oven under conditions that obtain a peak metal temperature of 193° C. for 45 seconds, does not exhibit any whitening visible to the unaided human eye after retort in 2% citric acid solution for 30 minutes at 121° C.

10 . The coating composition of claim 1 , wherein the coating composition, when spray applied via airless spray application to an interior of an aluminum beverage can at an average cured in an oven under conditions that obtain a peak metal temperature of 193° C. for 45 seconds, passes less than 1.5 mA of current when tested pursuant to the Metal Exposure After Drop Damage test disclosed herein.

11 . The coating composition of claim 1 , wherein the metallic base includes aluminum, calcium, lithium, magnesium, sodium, or potassium.

12 . The coating composition of claim 1 , wherein the metallic base comprises sodium hydroxide.

13 . The coating composition of claim 1 , wherein the coating composition includes at least 0.5% by weight of the first surfactant, based on the total combined weight of first surfactant and the ethylenically unsaturated monomer component.

14 . The coating composition of claim 1 , wherein the first surfactant has a number average molecular weight of less than 1,000 Daltons or less than about 500 Daltons.

15 . The coating composition of claim 1 , wherein the first surfactant is saturated, and wherein the first surfactant includes one or more heteroatom-containing linkages.

16 . The coating composition of claim 1 , wherein the first surfactant includes one or more ester linkages.

17 . The coating composition of claim 1 , wherein the first surfactant is a sulfosuccinate-type surfactant.

18 . The coating composition of claim 17 , wherein the first surfactant comprises dioctyl sodium sulfosuccinate.

19 . The coating composition of claim 1 , wherein the ethylenically unsaturated monomer component includes a multi-ethylenically unsaturated monomer.

20 . The coating composition of claim 1 , wherein the ethylenically unsaturated monomer component includes more than 5% by weight of multi-ethylenically unsaturated monomer.

21 . The coating composition of claim 1 , wherein the ethylenically unsaturated monomer component in polymerized in the aqueous media in the presence of both the first surfactant and a second surfactant, and wherein the second surfactant is a non-ionic surfactant.

22 . The coating composition of claim 21 , wherein the non-ionic surfactant is ethoxylated.

23 . The coating composition of claim 21 , wherein the non-ionic surfactant comprises a sucrose ester, sorbitan ester, alkyl glycoside, polyglycerol ester, or mixture thereof.

24 . The coating composition of claim 21 , wherein the non-ionic surfactant includes one or more hydroxyl groups.

25 . The coating composition of claim 1 , wherein the latex polymer has a glass transition temperature of from about 50° C. to about 120° C.

26 . A method of coating a food or beverage container, comprising applying the coating composition of claim 1 on a metal substrate prior to, or after, forming the metal substrate into a food or beverage container or a portion thereof.

27 . The method of claim 26 , wherein the coating composition is spray applied on an interior surface of an aluminum beverage can and cured to form a continuous cured coating having an average film thickness of from about 2 to about 15 microns.

28 . A food or beverage container, or a portion thereof, resulting from the method of claim 26 .

29 . A food or beverage container, or a portion thereof, having a metal substrate with a coating disposed thereon formed from the coating composition of claim 1 .

30 . The food or beverage container of claim 28 or 29 , or portion thereof, wherein the cured coating has a Tg of at least 50° C.

31 . The method of claim 27 , wherein the cured coating has a Tg of at least 50° C.

Assignees

• Swimc Llc

Inventors

• Gibanel Sebastien
• Prouvost Benoit

Classifications

• C09D125/14 Primary

  with unsaturated esters · CPC title

• C08F222/1025

  of aromatic dialcohols · CPC title

• C08F220/1802

  C2-(meth)acrylate, e.g. ethyl (meth)acrylate · CPC title

• C08F2/24 Primary

  with the aid of emulsifying agents · CPC title

• C08F212/08

  Styrene · CPC title