WO2011009024A1 - Compositions de revêtement pour des boîtes et procédés de revêtement - Google Patents

Compositions de revêtement pour des boîtes et procédés de revêtement Download PDF

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Publication number
WO2011009024A1
WO2011009024A1 PCT/US2010/042226 US2010042226W WO2011009024A1 WO 2011009024 A1 WO2011009024 A1 WO 2011009024A1 US 2010042226 W US2010042226 W US 2010042226W WO 2011009024 A1 WO2011009024 A1 WO 2011009024A1
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WO
WIPO (PCT)
Prior art keywords
polymer
parts
acid
ethylenically unsaturated
article
Prior art date
Application number
PCT/US2010/042226
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English (en)
Inventor
Robert M. O'brien
Daniel E. Rardon
Rachael Spynda
George K. Bartley, Iii
Richard H. Evans
T. Howard Killilea
Carl Cavallin
Bruce G. Sicklesteel
Original Assignee
Valspar Sourcing, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Priority claimed from US12/505,250 external-priority patent/US8173265B2/en
Application filed by Valspar Sourcing, Inc. filed Critical Valspar Sourcing, Inc.
Publication of WO2011009024A1 publication Critical patent/WO2011009024A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
    • C08G18/65—Low-molecular-weight compounds having active hydrogen with high-molecular-weight compounds having active hydrogen
    • C08G18/66—Compounds of groups C08G18/42, C08G18/48, or C08G18/52
    • C08G18/6625—Compounds of groups C08G18/42, C08G18/48, or C08G18/52 with compounds of group C08G18/34
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F265/00—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00
    • C08F265/04—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00 on to polymers of esters
    • C08F265/06—Polymerisation of acrylate or methacrylate esters on to polymers thereof
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
    • C08F283/006—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polymers provided for in C08G18/00
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
    • C08F283/02—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polycarbonates or saturated polyesters
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/08—Processes
    • C08G18/0804—Manufacture of polymers containing ionic or ionogenic groups
    • C08G18/0819—Manufacture of polymers containing ionic or ionogenic groups containing anionic or anionogenic groups
    • C08G18/0823—Manufacture of polymers containing ionic or ionogenic groups containing anionic or anionogenic groups containing carboxylate salt groups or groups forming them
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/08—Processes
    • C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
    • C08G18/12—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step using two or more compounds having active hydrogen in the first polymerisation step
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D151/00—Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers
    • C09D151/003—Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D151/00—Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers
    • C09D151/08—Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers grafted on to macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F212/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring
    • C08F212/02—Monomers containing only one unsaturated aliphatic radical
    • C08F212/04—Monomers containing only one unsaturated aliphatic radical containing one ring
    • C08F212/06—Hydrocarbons
    • C08F212/08—Styrene
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/04—Acids; Metal salts or ammonium salts thereof
    • C08F220/06—Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/10—Esters
    • C08F220/12—Esters of monohydric alcohols or phenols
    • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
    • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
    • C08F220/1804—C4-(meth)acrylate, e.g. butyl (meth)acrylate, isobutyl (meth)acrylate or tert-butyl (meth)acrylate
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G2390/00—Containers
    • C08G2390/40—Inner coatings for containers

Definitions

  • a wide variety of coatings have been used to coat the surfaces of packaging articles (e.g., food and beverage cans).
  • metal cans are sometimes coated using "coil coating” or "sheet coating” operations, i.e., a planar coil or sheet of a suitable substrate (e.g., steel or aluminum metal) is coated with a suitable composition and hardened (e.g., cured).
  • a suitable substrate e.g., steel or aluminum metal
  • the coated substrate then is formed into the can end or body.
  • liquid coating compositions may be applied (e.g., by spraying, dipping, rolling, etc.) to the formed article and then hardened (e.g., cured).
  • Packaging coatings should preferably be capable of high-speed application to the substrate and provide the necessary properties when hardened to perform in this demanding end use.
  • the coating should be safe for food contact, have excellent adhesion to the substrate, and resist degradation over long periods of time, even when exposed to harsh environments.
  • BPA bisphenol A
  • PVC aromatic glycidyl ether compounds
  • a packaging container e.g., a food or beverage can
  • a composition that does not contain extractible quantities of such compounds.
  • This invention provides a coating composition for a food or beverage can that includes an emulsion polymerized latex polymer.
  • This polymer is preferably formed by combining an ethylenically unsaturated monomer component with an aqueous dispersion of a salt of an acid- or anhydride- functional polymer (i.e., an acid group- or anhydride group- containing polymer) and an amine, preferably, a tertiary amine, and then polymerizing the monomer component.
  • an acid- or anhydride- functional polymer i.e., an acid group- or anhydride group- containing polymer
  • an amine preferably, a tertiary amine
  • the latex polymer is alternatively formed by combining the ethylenically unsaturated monomer component with an aqueous dispersion of a polymer salt or other water-dispersible polymer, which may or may not include neutralized acid or anhydride groups.
  • the water-dispersible polymer may include any suitable water-dispersing groups, such as anionic salt groups, cationic salt groups, non-ionic water-dispersing groups, or combinations thereof, to facilitate formation of a stable aqueous dispersion.
  • the ethylenically unsaturated monomer component is preferably a mixture of monomers.
  • at least one of the monomers in the mixture is preferably an alpha, beta-unsaturated monomer, and at least one monomer is preferably an oxirane functional monomer. More preferably, at least one of the monomers in the mixture is an oxirane group-containing alpha, beta-ethylenically unsaturated monomer.
  • a method of preparing a food or beverage can includes: forming a composition that includes an emulsion polymerized latex polymer, including: forming a salt of an acid- or anhydride- functional polymer and an amine in a carrier comprising water (and an optional organic solvent) to form an aqueous dispersion; combining an ethylenically unsaturated monomer component with the aqueous dispersion; and polymerizing the ethylenically unsaturated monomer component in the presence of the aqueous dispersion to form an emulsion polymerized latex polymer; and applying the composition including the emulsion polymerized latex polymer to a metal substrate prior to or after forming the metal substrate into a food or beverage can or portion thereof.
  • the above method utilizes an aqueous dispersion that includes a polymer salt having (i) salt groups formed from salt-forming groups other than acid or anhydride groups and/
  • the method includes: forming a composition including an emulsion polymerized latex polymer, including: forming a salt of an acid- or anhydride- functional polymer and a tertiary amine in a carrier comprising water (and an optional organic solvent) to form an aqueous dispersion; combining an ethylenically unsaturated monomer component comprising 0.1 percent by weight (wt-%) to 30 wt-% of an oxirane- functional alpha, beta-ethylenically unsaturated monomer with the aqueous dispersion, based on the weight of the monomer component; and polymerizing the ethylenically unsaturated monomer component in the presence of the aqueous dispersion to form an emulsion polymerized latex polymer; and applying the composition comprising the emulsion polymerized latex polymer to a metal substrate prior to or after forming the metal substrate into a food or beverage can or portion thereof.
  • the composition can include an organic solvent in the aqueous dispersion.
  • the method can include removing at least a portion of the organic solvent, if present, from the aqueous dispersion.
  • applying the composition to a metal substrate includes applying the composition to the metal substrate in the form of a planar coil or sheet, hardening the emulsion polymerized latex polymer, and forming the substrate into a food or beverage can or portions thereof.
  • applying the composition to a metal substrate comprises applying the composition to the metal substrate after the metal substrate is formed into a can or portion thereof.
  • forming the substrate into a can or portion thereof includes forming the substrate into a can end or a can body.
  • the can is a two-piece drawn food can, three-piece food can, food can end, drawn and ironed food or beverage can, beverage can end, and the like.
  • the metal substrate can be steel or aluminum.
  • combining an ethylenically unsaturated monomer component with the aqueous dispersion includes adding the ethylenically unsaturated monomer component to the aqueous dispersion.
  • the ethylenically unsaturated monomer component may be added incrementally to the aqueous dispersion, or in a batch addition.
  • the ethylenically unsaturated monomer component includes a mixture of monomers.
  • the mixture of monomers includes at least one oxirane functional group-containing monomer, and more preferably, at least one oxirane functional group-containing alpha, beta-ethylenically unsaturated monomer.
  • the oxirane functional group-containing monomer is present in the ethylenically unsaturated monomer component in an amount of at least 0.1 wt-%, based on the weight of the monomer mixture.
  • the oxirane functional group- containing monomer is present in the ethylenically unsaturated monomer component in an amount of no greater than 30 wt-%, based on the weight of the monomer mixture. In some embodiments, the unsaturated monomer component does not include any monomers having oxirane groups.
  • the methods of the present invention further include combining the emulsion polymerized latex polymer with one or more crosslinkers, fillers, catalysts, dyes, pigments, toners, extenders, lubricants, anticorrosion agents, flow control agents, thixotropic agents, dispersing agents, antioxidants, adhesion promoters, light stabilizers, organic solvents, surfactants or combinations thereof in the coating composition.
  • the acid-functional polymer has a number average molecular weight of 1500 to 50,000.
  • the composition is substantially free of mobile BPA and aromatic glycidyl ether compounds.
  • the composition is substantially free of bound BPA and aromatic glycidyl ether compounds.
  • the acid- or anhydride-functional polymer includes an acid- or anhydride-functional acrylic polymer, acid- or anhydride-functional alkyd resin, acid- or anhydride-functional polyester resin, acid- or anhydride-functional polyurethane, or combinations thereof.
  • the acid- or anhydride-functional polymer includes an acid-functional acrylic polymer.
  • the polymer (e.g., acrylic, alkyd, polyester, and/or polyurethane) used to form the aqueous dispersion may include any suitable combination of salt groups, salt-forming groups, or non-ionic water-dispersing groups.
  • the polymer of the aqueous dispersion may include anionic salt groups, cationic salt groups, salt-forming groups that yield an anionic or cationic salt group (e.g., when neutralized with a suitable acid or base), non-ionic water-dispersing groups, or a combination thereof.
  • the amine is a tertiary amine.
  • the tertiary amine is selected from the group consisting of trimethyl amine, dimethylethanol amine (also known as dimethylamino ethanol), methyldiethanol amine, triethanol amine, ethyl methyl ethanol amine, dimethyl ethyl amine, dimethyl propyl amine, dimethyl 3 -hydroxy- 1 -propyl amine, dimethylbenzyl amine, dimethyl 2-hydroxy-l -propyl amine, diethyl methyl amine, dimethyl l-hydroxy-2-propyl amine, triethyl amine, tributyl amine, N-methyl morpholine, and mixtures thereof.
  • the acid- or anhydride- functional polymer is at least 25% neutralized with the amine in water.
  • the ethylenically unsaturated monomer component is polymerized in the presence of the aqueous dispersion with a water-soluble free radical initiator at a temperature of O 0 C to 100 0 C.
  • the free radical initiator includes a peroxide initiator.
  • the free radical initiator includes hydrogen peroxide and benzoin.
  • the free radical initiator includes a redox initiator system.
  • the present invention also provides food cans and beverage cans prepared by a method described herein.
  • the present invention provides a food or beverage can that includes: a body portion or an end portion including a metal substrate; and a coating composition disposed thereon, wherein the coating composition includes an emulsion polymerized latex polymer, wherein the emulsion polymerized latex polymer is prepared from a salt of an acid- or anhydride-functional polymer and an amine, an ethylenically unsaturated monomer component, and water.
  • the emulsion polymerized latex polymer of the food or beverage can coating includes a different polymer salt in addition to, or in place of, the salt of an acid- or anhydride-functional polymer.
  • the present invention provides a composition for use in coating a food or beverage can, wherein the composition includes an emulsion polymerized latex polymer, wherein the emulsion polymerized latex polymer is prepared from a salt of an acid- or anhydride-functional polymer and an amine, an ethylenically unsaturated monomer component, and water.
  • the emulsion polymerized latex polymer of the coating composition includes a different polymer salt in addition to, or in place of, the salt of an acid- or anhydride-functional polymer.
  • the term "substantially free” of a particular mobile compound means that the compositions of the present invention contain less than 1000 parts per million (ppm) of the recited mobile compound.
  • the term “essentially free” of a particular mobile compound means that the compositions of the present invention contain less than 100 parts per million (ppm) of the recited mobile compound.
  • the term “essentially completely free” of a particular mobile compound means that the compositions of the present invention contain less than 5 parts per million (ppm) of the recited mobile compound.
  • the term “completely free” of a particular mobile compound means that the compositions of the present invention contain less than 20 parts per billion (ppb) of the recited mobile compound.
  • the term "mobile” means that the compound can be extracted from the cured coating when a coating (typically, approximate film weight of 1 mg/cm 2 ) is exposed to a test medium for some defined set of conditions, depending on the end use.
  • a coating typically, approximate film weight of 1 mg/cm 2
  • An example of these testing conditions is exposure of the cured coating to 10 weight percent ethanol solution for two hours at 121°C followed by exposure for 10 days in the solution at 49°C.
  • compositions of the present invention contain less than the aforementioned amount of the compound whether the compound is mobile in the coating or bound to a constituent of the coating.
  • organic group means a hydrocarbon group (with optional elements other than carbon and hydrogen, such as oxygen, nitrogen, sulfur, and silicon) that is classified as an aliphatic group, cyclic group, or combination of aliphatic and cyclic groups (e.g., alkaryl and aralkyl groups).
  • aliphatic group means a saturated or unsaturated linear or branched hydrocarbon group. This term is used to encompass alkyl, alkenyl, and alkynyl groups, for example.
  • alkyl group means a saturated linear or branched hydrocarbon group including, for example, methyl, ethyl, isopropyl, t-butyl, heptyl, dodecyl, octadecyl, amyl, 2-ethylhexyl, and the like.
  • alkenyl group means an unsaturated, linear or branched hydrocarbon group with one or more carbon-carbon double bonds, such as a vinyl group.
  • alkynyl group means an unsaturated, linear or branched hydrocarbon group with one or more carbon-carbon triple bonds.
  • cyclic group means a closed ring hydrocarbon group that is classified as an alicyclic group or an aromatic group, both of which can include heteroatoms.
  • alicyclic group means a cyclic hydrocarbon group having properties resembling those of aliphatic groups.
  • Ar refers to a divalent aryl group (i.e., an arylene group), which refers to a closed aromatic ring or ring system such as phenylene, naphthylene, biphenylene, fluorenylene, and indenyl, as well as heteroarylene groups (i.e., a closed ring hydrocarbon in which one or more of the atoms in the ring is an element other than carbon (e.g., nitrogen, oxygen, sulfur, etc.)).
  • arylene group i.e., an arylene group
  • a closed aromatic ring or ring system such as phenylene, naphthylene, biphenylene, fluorenylene, and indenyl
  • heteroarylene groups i.e., a closed ring hydrocarbon in which one or more of the atoms in the ring is an element other than carbon (e.g., nitrogen, oxygen, sulfur, etc.)
  • Suitable heteroaryl groups include furyl, thienyl, pyridyl, quinolinyl, isoquinolinyl, indolyl, isoindolyl, triazolyl, pyrrolyl, tetrazolyl, imidazolyl, pyrazolyl, oxazolyl, thiazolyl, benzofuranyl, benzothiophenyl, carbazolyl, benzoxazolyl, pyrimidinyl, benzimidazolyl, quinoxalinyl, benzothiazolyl, naphthyridinyl, isoxazolyl, isothiazolyl, purinyl, quinazolinyl, pyrazinyl, 1 -oxidopyridyl, pyridazinyl, triazinyl, tetrazinyl, oxadiazolyl, thiadiazolyl, and so on.
  • heteroarylene groups e.g., furylene, pyridylene, etc.
  • a group that may be the same or different is referred to as being “independently” something.
  • alkyl group is intended to include not only pure open chain saturated hydrocarbon alkyl substituents, such as methyl, ethyl, propyl, t-butyl, and the like, but also alkyl substituents bearing further substituents known in the art, such as hydroxy, alkoxy, alkylsulfonyl, halogen atoms, cyano, nitro, amino, carboxyl, etc.
  • alkyl group includes ether groups, haloalkyls, nitroalkyls, carboxyalkyls, hydroxyalkyls, sulfoalkyls, etc.
  • alkyl moiety is limited to the inclusion of only pure open chain saturated hydrocarbon alkyl substituents, such as methyl, ethyl, propyl, t-butyl, and the like.
  • a coating composition that comprises “a” polymer can be interpreted to mean that the coating composition includes “one or more” polymers.
  • This invention provides a coating composition for use on food and beverage cans that includes a latex polymer.
  • the polymer is prepared in an emulsion polymerization process, preferably a free radical initiated polymerization process.
  • the latex polymer can be applied to a metal substrate either before or after the substrate is formed into a food or beverage can (e.g., two-piece cans, three-piece cans) or portions thereof, whether it be a can end or can body.
  • the latex polymers of the present invention are suitable for use in food contact situations and may be used on the inside of such cans. They are particularly useful on the interior of two-piece drawn and ironed beverage cans and on beverage can ends.
  • the latex polymer is prepared by polymerizing an ethylenically unsaturated monomer component in an aqueous medium in the presence of the salt of an acid group- or anhydride group-containing polymer and an amine, preferably, a tertiary amine.
  • the ethylenically unsaturated monomer component is preferably a mixture of monomers.
  • at least one of the monomers in the mixture is an alpha, beta- ethylenically unsaturated monomer, and preferably at least one of the monomers contains an oxirane groups. More preferably, at least one of the monomers is an oxirane group- containing alpha, beta-ethylenically unsaturated monomer.
  • the latex polymer is prepared by polymerizing the ethylenically unsaturated monomer component in the presence of an aqueous dispersion of a polymer, such as for example, a water-dispersible polyester resin, alkyd resin, polyurethane resin, or a combination thereof.
  • a polymer such as for example, a water-dispersible polyester resin, alkyd resin, polyurethane resin, or a combination thereof.
  • the polymer of the aqueous dispersion can be made water- dispersible by incorporating non-ionic water-dispersing groups, salt groups (e.g., anionic and/or cationic salt groups), or a combination thereof.
  • salt groups e.g., anionic and/or cationic salt groups
  • water- dispersing groups also encompasses water-solubolizing groups.
  • composition may optionally include crosslinkers, fillers, catalysts, dyes, pigments, toners, extenders, lubricants, anticorrosion agents, flow control agents, thixotropic agents, dispersing agents, antioxidants, adhesion promoters, light stabilizers, surfactants, organic solvents, and mixtures thereof as required to provide the desired film properties.
  • the coating composition is prepared by: forming a salt of an acid- functional or anhydride-functional polymer and an amine; dispersing the salt in a carrier that includes water and an optional organic solvent to form an aqueous dispersion; optionally removing the organic solvent, if present, from the aqueous dispersion; combining an ethylenically unsaturated monomer component with the aqueous dispersion (preferably, the ethylenically unsaturated monomer component is added to the aqueous dispersion); and polymerizing the ethylenically unsaturated monomer component in the presence of the aqueous dispersion to form an emulsion polymerized latex polymer.
  • a neutralizing base other than an amine may be used to form the salt of the acid-functional or anhydride-functional polymer.
  • a polymer salt including salt groups other than neutralized acid or anhydride groups may be used.
  • compositions are substantially free of mobile bisphenol A (BPA) and aromatic glycidyl ether compounds (e.g., BADGE, BFDGE, and epoxy novalacs), more preferably essentially free of these compounds, even more preferably essentially completely free of these compounds, and most preferably completely free of these compounds.
  • BPA mobile bisphenol A
  • aromatic glycidyl ether compounds e.g., BADGE, BFDGE, and epoxy novalacs
  • the coating composition is also preferably substantially free of bound BPA and aromatic glycidyl ether compounds, more preferably essentially free of these compounds, most preferably essentially completely free of these compounds, and optimally completely free of these compounds.
  • Preferred emulsion polymerized latex polymers are at least substantially "epoxy - free", more preferably "epoxy- free.”
  • epoxy- free when used herein in the context of a polymer, refers to a polymer that does not include any epoxy backbone segments. Thus, for example, a polymer made from ingredients including an epoxy resin would not be considered epoxy-free. Similarly, a polymer having backbone segments that are the reaction product of a bisphenol (e.g., bisphenol A, bisphenol F, bisphenol S, 4,4'dihydroxy bisphenol, etc.) and a halohdyrin (e.g., epichlorohydrin) would not be considered epoxy-free.
  • the coating composition is also preferably at least substantially epoxy-free, more preferably epoxy-free.
  • Preferred emulsion polymerized latex polymers do not include any structural units derived from aromatic isocyanate compounds.
  • the ethylenically unsaturated monomer component is preferably a mixture of monomers that is capable of free radical initiated polymerization in aqueous medium.
  • the monomer mixture preferably contains at least one oxirane functional monomer, and more preferably, at least one oxirane group-containing alpha, beta-ethylenically unsaturated monomer.
  • the monomer mixture preferably contains at least 0.1 wt-%, more preferably at least 1 wt-%, of an oxirane group-containing monomer, based on the weight of the monomer mixture.
  • at least 0.1 wt-% of the oxirane group-containing monomer contributes to the stability of the latex. Although not intended to be limited by theory, it is believed that this is because of the reduction in the amount of quaternary salt formation between the oxirane species, acid group-containing polymer, and amine, which can cause coagulation of the latex.
  • at least 0.1 wt-% of the oxirane group-containing monomer contributes to crosslinking in the dispersed particles and during cure, resulting in better properties of coating compositions formulated with the polymeric latices.
  • the monomer mixture preferably contains no greater than 30 wt-%, more preferably no greater than 20 wt-%, even more preferably no greater than 10 wt-%, and optimally no greater than 9 wt-%, of the oxirane group-containing monomer, based on the weight of the monomer mixture.
  • greater than 30 wt-% of the oxirane group- containing monomer in the monomer mixture can contribute to diminished film properties. Although not intended to be limited by theory, it is believed that this is due to embrittlement caused by an overabundance of crosslinking.
  • the monomer mixture does not contain any oxirane-group containing monomer.
  • Suitable oxirane- functional monomers include monomers having a reactive carbon-carbon double bond and an oxirane (i.e., a glycidyl) group.
  • the monomer is a glycidyl ester of an alpha, beta-unsaturated acid, or anhydride thereof (i.e., an oxirane group-containing alpha, beta-ethylenically unsaturated monomer).
  • Suitable alpha, beta- unsaturated acids include monocarboxylic acids or dicarboxylic acids.
  • carboxylic acids include, but are not limited to, acrylic acid, methacrylic acid, alpha- chloroacrylic acid, alpha-cyanoacrylic acid, beta-methylacrylic acid (crotonic acid), alpha- phenylacrylic acid, beta-acryloxypropionic acid, sorbic acid, alpha-chlorosorbic acid, angelic acid, cinnamic acid, p-chlorocinnamic acid, beta-stearylacrylic acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, aconitic acid, maleic acid, fumaric acid,
  • Suitable monomers containing a glycidyl group are glycidyl (meth)acrylate (i.e., glycidyl methacrylate and glycidyl acrylate), mono- and di-glycidyl itaconate, mono- and di-glycidyl maleate, and mono- and di-glycidyl formate. It also is envisioned that allyl glycidyl ether and vinyl glycidyl ether can be used as the oxirane- functional monomer.
  • a preferred monomer is glycidyl methacrylate ("GMA").
  • the oxirane-functional monomer is preferably reacted with suitable other monomers within the monomer mixture. These can be ethylenically unsaturated monomer and hydroxy-functional monomers. Suitable ethylenically unsaturated monomers include alkyl (meth)acrylates, vinyl monomers, alkyl esters of maleic or fumaric acid, and the like.
  • Suitable alkyl (meth)acrylates include those having the structure:
  • R 1 is hydrogen or methyl
  • R 2 is an alkyl group preferably containing one to sixteen carbon atoms.
  • the R group can be substituted with one or more, and typically one to three, moieties such as hydroxy, halo, phenyl, and alkoxy, for example.
  • Suitable alkyl (meth)acrylates therefore encompass hydroxy alkyl (meth)acrylates.
  • the alkyl (meth)acrylate typically is an ester of acrylic or methacrylic acid.
  • R 1 is hydrogen or methyl and R 2 is an alkyl group having two to eight carbon atoms.
  • R 1 is hydrogen or methyl and R 2 is an alkyl group having two to four carbon atoms.
  • alkyl (meth)acrylates include, but are not limited to, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, decyl
  • (meth)acrylate isodecyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, isobornyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, hydroxyethyl acrylate (HEA), hydroxyethyl methacrylate (HEMA), hydroxypropyl (meth)acrylate (HPMA).
  • Difunctional (meth)acrylate monomers may be used in the monomer mixture as well. Examples include ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, allyl methacrylate, and the like.
  • Suitable vinyl monomers include styrene, methyl styrene, halostyrene, isoprene, diallylphthalate, divinylbenzene, conjugated butadiene, alpha-methylstyrene, vinyl toluene, vinyl naphthalene, and mixtures thereof.
  • the vinyl aromatic monomers described below in connection with the acid- or anhydride-functional polymer are also suitable for use in the ethylenically unsaturated monomer component used to make the latex polymer.
  • Styrene is a presently preferred vinyl monomer, in part due to its relatively low cost.
  • Suitable polymerizable vinyl monomers for use in the ethylenically unsaturated monomer component include acrylonitrile, acrylamide, methacrylamide, methacrylonitrile, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl stearate, N- isobutoxymethyl acrylamide, N-butoxymethyl acrylamide, and the like.
  • the oxirane group-containing monomer preferably constitutes
  • wt-% 0.1 wt-% to 30 wt-%, and more preferably 1 wt-% to 20 wt-%, of the ethylenically unsaturated monomer component.
  • the other monomer or monomers in the mixture constitute the remainder of the monomer component, that is, 70 wt-% to 99.9 wt-%, preferably 80 wt-% to 99 wt-%, based on total weight of the monomer mixture.
  • At least 40 wt-% of the ethylenically unsaturated monomer component will be selected from alkyl acrylates and methacrylates.
  • at least 20 wt-%, more preferably at least 30 wt-% will be selected from vinyl aromatic compounds.
  • At least 5 wt-%, more preferably at least 25 wt-%, even more preferably at least 50 wt-%, and even more preferably at least 60 wt-%, of the ethylenically unsaturated monomer component is used in making the latex polymer.
  • no greater than 95 wt-%, more preferably no greater than 90 wt-%, and even more preferably no greater than 85 wt-%, of the ethylenically unsaturated monomer component is used in making the latex polymer.
  • Such percentages are based on total weight of ethylenically unsaturated monomer component and salt of the acid group-containing or anhydride group- containing polymer (i.e., acid-functional or anhydride-functional polymer)).
  • the choice of the acid-containing or anhydride-containing monomer(s) is dictated by the intended end use of the coating composition and is practically unlimited.
  • the acid-containing polymer i.e., acid-functional polymer
  • the acid-containing polymer preferably has an acid number of at least 40, and more preferably at least 100, milligrams (mg) KOH per gram resin.
  • the acid-containing polymer preferably has an acid number of no greater than 400, and more preferably no greater than 300, mg KOH per gram resin.
  • the anhydride- containing polymer when in water, preferably has similar acid number ranges.
  • the molecular weight of the acid- or anhydride-functional polymer is no greater than 50,000 on a number average molecular weight basis, and preferably no greater than 20,000.
  • the molecular weight of the acid- or anhydride-functional polymer is at least 1500 on a number average molecular weight basis, and more preferably at least 2000.
  • salt- forming groups other than acid- or anhydride- groups are used, the molecular weight of the polymer salt will typically fall within the above parameters.
  • Preferred acid- or anhydride-functional polymers that may be employed include acid-functional or anhydride-functional acrylic polymers, alkyd resins, polyester polymers, and polyurethanes. Combinations of such polymers can be used if desired.
  • the term polymer includes both homopolymers and copolymers (i.e., polymers of two or more different monomers).
  • Preferred acid- or anhydride-functional polymers utilized in this invention include those prepared by conventional free radical polymerization techniques. Suitable examples include those prepared from unsaturated acid- or anhydride-functional monomers, or salts thereof, and other unsaturated monomers. Of these, preferred examples include those prepared from at least 15 wt-%, more preferably at least 20 wt-%, unsaturated acid- or anhydride-functional monomer, or salts thereof, and the balance other polymerizable unsaturated monomer. Examples of co-monomers described previously apply here as well.
  • a variety of acid- or anhydride-functional monomers, or salts thereof, can be used; their selection is dependent on the desired final polymer properties.
  • such monomers are ethylenically unsaturated, more preferably, alpha, beta-ethylenically unsaturated.
  • Suitable ethylenically unsaturated acid- or anhydride-functional monomers for the present invention include monomers having a reactive carbon-carbon double bond and an acidic or anhydride group, or salts thereof.
  • Preferred such monomers have from 3 to 20 carbons, at least 1 site of unsaturation, and at least 1 acid or anhydride group, or salt thereof.
  • Suitable acid-functional monomers include ethylenically unsaturated acids (mono-protic or diprotic), anhydrides or monoesters of a dibasic acid, which are
  • Half-esters of these acids with alkanols of 1 to 8 carbon atoms are also suitable.
  • Non-limiting examples of useful ethylenically unsaturated acid-functional monomers include acids such as, for example, acrylic acid, methacrylic acid, alpha- chloroacrylic acid, alpha-cyanoacrylic acid, crotonic acid, alpha-phenylacrylic acid, beta- acryloxypropionic acid, fumaric acid, maleic acid, sorbic acid, alpha-chlorosorbic acid, angelic acid, cinnamic acid, p-chlorocinnamic acid, beta-stearylacrylic acid, citraconic acid, mesaconic acid, glutaconic acid, aconitic acid, tricarboxyethylene, 2-methyl maleic acid, itaconic acid, 2-methyl itaconic acid, methyleneglutaric acid, and the like, or mixtures thereof.
  • acids such as, for example, acrylic acid, methacrylic acid, alpha- chloroacrylic acid, alpha-cyanoacrylic acid, crotonic acid, alpha-
  • Preferred unsaturated acid-functional monomers include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, 2-methyl maleic acid, itaconic acid, 2-methyl itaconic acid, and mixtures thereof. More preferred unsaturated acid- functional monomers include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, and mixtures thereof. Most preferred unsaturated acid-functional monomers include acrylic acid, methacrylic acid, maleic acid, crotonic acid, and mixtures thereof.
  • Nonlimiting examples of suitable ethylenically unsaturated anhydride monomers include compounds derived from the above acids (e.g., as pure anhydride or mixtures of such).
  • Preferred anhydrides include acrylic anhydride, methacrylic anhydride, and maleic anhydride. If desired, aqueous salts of the above acids may also be employed.
  • acid- or anhydride-functional acrylic polymers can also be used in the practice of the invention.
  • acid- or anhydride-functional alkyd polyester, polyurethane resins, or combinations thereof.
  • polyester, polyurethane resins, or combinations thereof can also be used in the practice of the invention.
  • Such polymers are described in U.S. Pat. Nos. 4,692,491; 3,479,310; and 4,147,679.
  • the acid- or anhydride- functional polymers are acid- functional acrylic polymers.
  • the acid- or anhydride-functional polymers are polyester polymers.
  • polyester polymers are disclosed in U.S. Provisional Patent Application Serial No. 60/727,734 (Attorney Docket No. 287.00220160), filed on, October 18, 2005 entitled COATING COMPOSITIONS FOR CONTAINERS AND
  • each Ar is independently a divalent aryl group (i.e., an arylene group) or heteroarylene group;
  • R 1 is a divalent organic group;
  • each R is independently a divalent organic group; and
  • n is 0 or 1. Any one polymer can have a variety of such segments, which may be the same or different.
  • R 1 provides hydrolytic stability to at least one of the adjacent ester linkages (-C(O)-O- and -O-C(O)-), and preferably to both of them.
  • the adjacent ester linkages -C(O)-O- and -O-C(O)-
  • hydrolytic stability means that R 1 decreases the reactivity (preferably, by at least half) of the adjacent ester linkage with water compared to a -CH 2 -CH 2 - moiety under the same conditions. This can be accomplished by selection of R 1 that includes a sterically bulky group in proximity (preferably within two atoms distance) to the oxygen of the ester.
  • the polymer preferably includes more than 70%, more preferably more than 80%, and even more preferably more than 90%, hydrolytically stable ester linkages (based on the total number of ester linkages).
  • R 1 is a divalent organic group, preferably, having at least 3 carbon atoms, more preferably, at least 4 carbon atoms, even more preferably, at least 5 carbon atoms, and even more preferably, at least 8 carbon atoms. It is envisioned that R 1 can be as large as desired for the particular application, which one of skill in the art can readily determine.
  • R 1 is of the formula
  • each R is independently hydrogen or an organic group (e.g., an alicyclic group or a branched or unbranched alkyl group), Y is a divalent organic group, and t is 0 or 1
  • each R is independently hydrogen.
  • Y can optionally include one or more ether or ester linkages.
  • Y is a divalent saturated aliphatic group (i.e., a branched or unbranched alkylene group), a divalent alicyclic group, or a divalent aromatic group (i.e., an arylene group), or combinations thereof.
  • Y is a divalent alkyl group (i.e., an alkylene group), which can be branched or unbranched, preferably having at least 1 carbon atom, more preferably having at least 2 carbon atoms, even more preferably having at least 3 carbon atoms, and even more preferably having at least 6 carbon atoms.
  • Y is a divalent alicylic group, preferably cyclohexylene. It is envisioned that Y can be as large as desired for the particular application, which one of skill in the art can readily determine.
  • Y provides hydro lytic stability to at least one of the ester linkages adjacent R 1 in Formula I. This can be accomplished by selection of Y that includes a sterically bulky group that is in proximity (preferably within two atoms) of at least one of the ester oxygen atoms in Formula I.
  • R 1 has the formula -(C(R 2 ) 2 ) S - wherein s is at least 2, and preferably, s is at least 3, wherein each R 2 is as defined above.
  • R 1 groups include, for example, neopentylene, butylethylpropylene, and -CH 2 -CH(CHs)-CH 2 -.
  • Y has the formula
  • each R 2 is as defined above, each R 3 is independently a divalent organic group, and each Z is independently a divalent organic group.
  • R 3 is a divalent saturated aliphatic group (i.e., branched or unbranched alkylene group), a divalent alicyclic group, an arylene group, or combinations thereof.
  • R is a (C3-C20)alkylene (branched or unbranched) group or a phenylene group.
  • Z is a divalent saturated aliphatic group (i.e., branched or unbranched alkylene group), a divalent alicyclic group, a divalent aromatic group (i.e., an arylene group), or combinations thereof.
  • Z provides hydrolytic stability to at least one of the ester linkages adjacent R 1 in Formula I and/or to an adjacent ester linkage contained within Y. This can be accomplished by selection of Z that includes a sterically bulky group that is in proximity (preferably within two atoms distance) of at least one of the ester oxygen atoms.
  • n is preferably 0 (i.e., R is not present). If n is 1 and R is present, however, it is preferably a (Cl-C4)alkylene group, and more preferably a (Cl-C4)alkylene moiety.
  • each Ar has less than 20 carbon atoms, more preferably less than 11 carbon atoms, and even more preferably less than 8 carbon atoms.
  • Ar has at least 4 carbon atoms, more preferably at least 5 carbon atoms, and even more preferably, at least 6 carbon atoms.
  • each Ar is a phenylene group.
  • each Ar is a phenylene group of the formula -Ce(R 4 V, wherein each R 4 is independently hydrogen, a halogen, or an organic group, and wherein two R 4 groups can join to form a ring optionally containing one or more heteroatoms.
  • R 4 is hydrogen or an organic group, wherein two R 4 groups can join to form a 6-membered ring.
  • R 4 is hydrogen.
  • Polyester polymers such as these can be made by a variety of methods from compounds of Formula II:
  • Such compounds can be made, for example, by the esterification reaction of one mole of a diol (e.g., HO-R ⁇ -OH such as, for example, 1,4-cyclohexane dimethanol, neopentyl glycol, 2-butyl-2-ethyl-l,3-propane diol, or
  • 2-methyl-l,3-propane diol with two moles of an acid (e.g., 4-hydroxy benzoic acid).
  • an acid e.g., 4-hydroxy benzoic acid
  • such compounds can be made, for example, by the transesterification reaction of one mole of a diol (e.g., 1,4-cyclohexane dimethanol, neopentyl glycol, 2-butyl-2-ethyl- 1,3-propane diol, or 2-methyl- 1,3 -propane diol) with two moles of an ester (e.g., 4-hydroxy methyl benzoate, 4-hydroxy ethyl benzoate, or 4-hydroxy butyl benzoate).
  • a diol e.g., 1,4-cyclohexane dimethanol, neopentyl glycol, 2-butyl-2-ethyl- 1,3-propane diol, or 2-methyl- 1,3 -propane diol
  • an ester e.g., 4-hydroxy methyl benzoate, 4-hydroxy ethyl benzoate, or 4-hydroxy butyl benzoate.
  • Polymers of Formula I can be prepared by methods that involve advancing the molecular weight of compounds of Formula II.
  • compounds of Formula II e.g., dihydric phenols
  • a diepoxide to advance the molecular weight.
  • compounds of Formula II e.g., dihydric phenols
  • non-BPA and non-BPF based diepoxides can be reacted with non-BPA and non-BPF based diepoxides much in the same manner that Bisphenol A or Bisphenol F do, to create polymers that can be formulated with crosslinkers and additives for coatings for rigid packaging.
  • compounds of Formula II can be reacted with a diepoxide to form a polymer that includes -CH 2 -CH(OH)-CH 2 - segments.
  • compounds of Formula II can be reacted with epichlorohydrin to form a diepoxide analog of compounds of Formula II, which can then be reacted with other compounds of Formula II to form a polymer that includes -CH 2 -CH(OH)-CH 2 - segments.
  • the diepoxide analogs of compounds of Formula II can be prepared by reacting the required proportions of a compound of Formula II (e.g., dihydric phenol) and epichlorohydrin in an alkaline medium.
  • the desired alkalinity is obtained by adding basic substances, such as sodium or potassium hydroxide, preferably in stoichiometric excess to the epichlorohydrin.
  • the reaction is preferably accomplished at temperatures of 50 0 C to 150 0 C. The heating is continued for several hours to effect the reaction and the product is then washed free of salt and base. Procedures for such reactions are generally well known and disclosed, for example, in U.S. Pat.
  • suitable diepoxides are BPA- or BPF-free diepoxides, preferably with one or more ether linkages.
  • Suitable diepoxides may be prepared by a variety of processes, for example, by the condensation of a dihydroxy compound and epichlorohydrin.
  • Suitable diepoxides include, for example, 1 ,4-cyclohexanedimethanol diglycidyl ether (CHDMDGE), resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, and 2-methyl-l,3-propandiol diglycidyl ether.
  • CHDMDGE 1 ,4-cyclohexanedimethanol diglycidyl ether
  • resorcinol diglycidyl ether resorcinol diglycidyl ether
  • neopentyl glycol diglycidyl ether 2-methyl-l,3-propandiol diglycidyl ether.
  • the resultant polymers of Formula I may be epoxy terminated or phenoxy terminated, for example. They may be made in a variety of molecular weights, such as the molecular weights of commercially available BPA-based epoxy materials (e.g., those available under trade designations such as EPON 828, 1001, 1007, 1009 from Resolution Performance Products, Houston, Texas). Preferred polymers of the present invention have a number average molecular weight (M n ) of at least 2,000, more preferably at least 3,000, and even more preferably at least 4,000. The molecular weight of the polymer may be as high as is needed for the desired application.
  • M n number average molecular weight
  • Typical catalysts usable in the advancement of the molecular weight of the epoxy material of the present invention include amines, hydroxides (e.g., potassium hydroxide), phosphonium salts, and the like.
  • a presently preferred catalyst is a phosphonium catalyst.
  • the phosphonium catalyst useful in the present invention is preferably present in an amount sufficient to facilitate the desired condensation reaction.
  • the epoxy terminated polymers of Formula I may be reacted with fatty acids to form polymers having unsaturated (e.g., air oxidizable) reactive groups, or with acrylic acid or methacrylic acid to form free radically curable polymers.
  • unsaturated e.g., air oxidizable
  • Advancement of the molecular weight of the polymer may also be enhanced by the reaction of an epoxy terminated polymer of Formula I with a suitable diacid (such as adipic acid).
  • a suitable diacid such as adipic acid
  • a salt (which can be a full salt or partial salt) of the acid- or anhydride-functional polymer is formed by neutralizing or partially neutralizing the acid groups (whether present initially in the acid-functional polymer or formed upon addition of the anhydride-functional polymer to water) of the polymer with a suitable base such as, for example, an amine, preferably a tertiary amine.
  • tertiary amines are trimethyl amine, dimethylethanol amine (also known as dimethylamino ethanol), methyldiethanol amine, triethanol amine, ethyl methyl ethanol amine, dimethyl ethyl amine, dimethyl propyl amine, dimethyl 3 -hydroxy- 1 -propyl amine, dimethylbenzyl amine, dimethyl 2-hydroxy-l -propyl amine, diethyl methyl amine, dimethyl l-hydroxy-2-propyl amine, triethyl amine, tributyl amine, N-methyl morpholine, and mixtures thereof. Most preferably triethyl amine or dimethyl ethanol amine is used as the tertiary amine.
  • the degree of neutralization required to form the desired polymer salt may vary considerably depending upon the amount of acid included in the polymer, and the degree of solubility or dispersibility of the salt which is desired.
  • the acidity of the polymer is at least 25% neutralized, preferably at least 30% neutralized, and more preferably at least 35% neutralized, with the amine in water.
  • the degree of neutralization may be pursuant to those described above.
  • the polymer of the aqueous dispersion includes a sufficient number of water- dispersing groups to form a stable aqueous dispersion.
  • any suitable salt-forming or water-dispersing group may be used in place of, or in addition to, acid or anhydride groups.
  • anionic salt groups include sulphate groups (-OS(V), phosphate groups (-OPO3 ), sulfonate groups (-SO 2 O ), phosphinate groups (-POO " ), phosphonate groups (-PO3 ), and
  • Suitable cationic salt groups include:
  • non-ionic water- dispersing groups include hydrophilic groups such as ethylene oxide groups.
  • neutralizing bases for forming anionic salt groups include inorganic and organic bases such as sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonium hydroxide, and mixtures thereof.
  • neutralizing compounds for forming cationic salt groups include organic and inorganic acids such as formic acid, acetic acid, hydrochloric acid, sulfuric acid, and combinations thereof.
  • the amount of the salt of the acid-functional or anhydride- functional polymer that is used in the polymerization is preferably at least 5 wt-%, more preferably at least 10 wt-%, and even more preferably at least 15 wt-%.
  • the amount of the salt of the acid- functional or anhydride- functional polymer that is used in the polymerization is preferably no greater than 95 wt-%, preferably no greater than 50 wt-%, and even more preferably no greater than 40 wt-%. These percentages are based on total weight of polymerizable ethylenically unsaturated monomer component and the salt of the acid group-containing polymer.
  • the total amount of the polymer used in the polymerization will typically fall within the above parameters, with the above percentages based on based on total weight of ethylenically unsaturated monomer component and water- dispersible polymers
  • one reaction involves the tertiary amine neutralized acid-functional polymer reacting with an oxirane-functional monomer or polymer to form a quaternary ammonium salt.
  • a second reaction involves esterification of the oxirane-functional monomer or polymer with a carboxylic acid or salt.
  • the presence of water and level of amine favor formation of quaternary ammonium salts over ester linkages.
  • a high level of quaternization improves water dispersability while a high level of esterification gives higher viscosity and possibly gel-like material.
  • the ethylenically unsaturated monomer component is preferably polymerized in aqueous medium with a water-soluble free radical initiator in the presence of the salt of the acid- or anhydride- functional polymer.
  • the temperature of polymerization is typically from 0 0 C to 100 0 C, preferably from 50 0 C to 90 0 C, more preferably from 70 0 C to 90 0 C, and even more preferably from 8O 0 C to 85 0 C.
  • the pH of the aqueous medium is usually maintained at a pH of 5 to 12.
  • the free radical initiator can be selected from one or more water-soluble peroxides which are known to act as free radical initiators. Examples include hydrogen peroxide and t-butyl hydroperoxide. Redox initiator systems well known in the art (e.g., t-butyl hydroperoxide, erythorbic acid, and ferrous complexes) can also be employed. In some embodiments, it is especially preferred to use a mixture of benzoin and hydrogen peroxide. Persulfate initiators such as ammonium persulfate or potassium persulfate are not preferred, as they lead to poor water resistance properties of the cured coating.
  • polymerization initiators which can be employed include polymerization initiators which thermally decompose at the polymerization temperature to generate free radicals. Examples include both water-soluble and water-insoluble species.
  • free radical initiators that can be used include persulfates, such as ammonium or alkali metal (potassium, sodium or lithium) persulfate; azo compounds such as 2,2'-azo-bis(isobutyronitrile), 2,2'-azo-bis(2,4-dimethylvaleronitrile), and 1-t-butyl- azocyanocyclohexane; hydroperoxides such as t-butyl hydroperoxide, hydrogen peroxide, t-amyl hydroperoxide, methyl hydroperoxide, and cumene hydroperoxide; peroxides such as benzoyl peroxide, caprylyl peroxide, di-t-butyl peroxide, ethyl 3,3'-di(t-but)
  • Polymerization initiators can be used alone or as the oxidizing component of a redox system, which also preferably includes a reducing component such as ascorbic acid, malic acid, glycolic acid, oxalic acid, lactic acid, thiogycolic acid, or an alkali metal sulfite, more specifically a hydrosulfite, hyposulfite or metabisulfite, such as sodium hydrosulfite, potassium hyposulfite and potassium metabisulfite, or sodium formaldehyde sulfoxylate, and combinations thereof.
  • the reducing component is frequently referred to as an accelerator or a catalyst activator.
  • the initiator and accelerator is preferably used in proportion from about 0.001% to 5% each, based on the weight of monomers to be copolymerized.
  • Promoters such as chloride and sulfate salts of cobalt, iron, nickel or copper can be used in small amounts, if desired.
  • redox catalyst systems include tert-butyl hydroperoxide/sodium formaldehyde sulfoxylate/Fe(II), and ammonium persulfate/sodium bisulfite/sodium hydrosulfite/Fe(II).
  • Chain transfer agents can be used to control polymer molecular weight, if desired.
  • the polymerization reaction of the ethylenically unsaturated monomer component in the presence of the aqueous dispersion of the polymer salt may be conducted as a batch, intermittent, or continuous operation. While all of the polymerization ingredients may be charged initially to the polymerization vessel, better results normally are obtained with proportioning techniques. In certain embodiments, however, it is desirable to charge all, or substantially all, of the ingredients to the polymerization vessel before commencing polymerization.
  • the reactor is charged with an appropriate amount of water, polymer salt, and free radical initiator.
  • the reactor is then heated to the free radical initiation temperature and then charged with the ethylenically unsaturated monomer component.
  • Preferably only water, initiator, polymer salt, and some portion of the ethylenically unsaturated monomer component are initially charged to the vessel. There may also be some water miscible solvent present. After this initial charge is allowed to react for a period of time at polymerization temperature, the remaining ethylenically unsaturated monomer component is added incrementally with the rate of addition being varied depending on the polymerization temperature, the particular initiator being employed, and the type and amount of monomers being polymerized. After all the monomer component has been charged, a final heating is carried out to complete the polymerization. The reactor is then cooled and the latex recovered.
  • a "batch" process may be used to polymerize the ethylenically unsaturated monomer component in the presence of the aqueous dispersion. While not intending to be bound by any theory, batch polymerization of the ethylenically unsaturated monomer component can result in a higher molecular weight polymerized component that may yield desirable performance properties for certain coating end uses such as, for example, beverage end coatings.
  • the polymerized ethylenically unsaturated monomer component has a M n of at least about 100,000, more preferably at least about 200,000, or even more preferably at least about 300,000.
  • the upper range of the M n of the polymerized ethylenically unsaturated monomer component is not restricted and may be 1,000,000 or more. In certain embodiments, however, the M n of the polymerized ethylenically unsaturated component is less than about 1,000,000, or less than about 600,000.
  • Redox initiation is presently preferred for use in batch polymerizing the ethylenically unsaturated component.
  • the benefits of a batch polymerization process may also be realized by (i) batch polymerizing, for example, a substantial portion (e.g., at least a majority) of the ethylencially unsaturated monomer component and then later (ii) adding the balance of the ethylenically unsaturated monomer component (e.g., through a continuous or intermittent feed) and completing the polymerization.
  • At least about 75 wt-%, more preferably at least about 85 wt-%, and even more preferably at least about 95 wt-% of the total amount of ethylenically unsaturated monomer component is present as unreacted monomer in the aqueous dispersion within a 1-hour time period (more preferably within a 30-minute time period) during polymerization of the ethylenically unsaturated monomer component, and more preferably at the same time (e.g., at the onset of polymerization of the ethylenically unsaturated monomer component).
  • polymerized ethylenically unsaturated monomer component constitutes at least about
  • the emulsion polymerized latex polymer exihibts a M n of at least about 100,000, more preferably at least about 200,000, and even more preferably at least about 300,000.
  • Coating compositions of the invention preferably include at least a film- forming amount of the latex polymer.
  • the coating composition includes at least about 5 wt-%, more preferably at least about 15 wt-%, and even more preferably at least about 25 wt-% of the latex polymer, based on the weight of the latex polymer solids relative to the total weight of the coating composition.
  • the coating composition includes less than about 65 wt-%, more preferably less than about 55 wt-%, and even more preferably less than about 45 wt-% of the latex polymer, based on the weight of the latex polymer solids relative to the total weight of the coating composition.
  • coating compositions using the aforementioned latices may be formulated using one or more optional curing agents (i.e., crosslinking resins, sometimes referred to as "crosslinkers").
  • crosslinkers optional curing agents
  • the choice of particular crosslinker typically depends on the particular product being formulated. For example, some coating
  • compositions are highly colored (e.g., gold-colored coatings). These coatings may typically be formulated using crosslinkers that themselves tend to have a yellowish color. In contrast, white coatings are generally formulated using non-yellowing crosslinkers, or only a small amount of a yellowing crosslinker.
  • Preferred curing agents are substantially free of mobile BPA and aromatic glycidyl ether compounds (e.g., BADGE, BFDGE and epoxy novalacs).
  • Any of the well known hydroxyl-reactive curing resins can be used.
  • phenoplast, and aminoplast curing agents may be used.
  • Phenoplast resins include the condensation products of aldehydes with phenols. Formaldehyde and acetaldehyde are preferred aldehydes.
  • Various phenols can be employed such as phenol, cresol, p-phenylphenol, p-tert-butylphenol, p-tert-amylphenol, and cyclopentylphenol.
  • Aminoplast resins are the condensation products of aldehydes such as formaldehyde, acetaldehyde, crotonaldehyde, and benzaldehyde with amino or amido group- containing substances such as urea, melamine, and benzoguanamine.
  • aldehydes such as formaldehyde, acetaldehyde, crotonaldehyde, and benzaldehyde with amino or amido group- containing substances such as urea, melamine, and benzoguanamine.
  • crosslinking resins include, without limitation,
  • the crosslinker employed when practicing this invention includes a melamine-formaldehyde resin.
  • a particularly useful crosslinker is the fully alkylated melamine-formaldehyde resin commercially available from Cytec Industries, Inc. under the trade name of CYMEL 303.
  • curing agents are the blocked or non- blocked aliphatic, cycloaliphatic or aromatic di-, tri-, or poly-valent isocyanates, such as hexamethylene diisocyanate (HMDI), cyclohexyl-l ⁇ -diisocyanate, and the like.
  • HMDI hexamethylene diisocyanate
  • blocked isocyanates include isomers of isophorone diisocyanate, dicyclohexylmethane diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, tetramethyl xylene diisocyanate, xylylene
  • blocked isocyanates are used that have a M n of at least about 300, more preferably at least about 650, and even more preferably at least about 1,000.
  • Polymeric blocked isocyanates are preferred in certain embodiments.
  • suitable polymeric blocked isocyanates include a biuret or isocyanurate of a diisocyanate, a trifunctional "trimer", or a mixture thereof.
  • Suitable blocked polymeric isocyanates include Trixene BI 7951, Trixene BI 7984, Trixene BI 7963, Trixene BI 7981 (Trixene materials are available from Baxenden Chemicals, Ltd., Accrington, Lancashire, England), Desmodur BL 3175A, Desmodur BL3272, Desmodur BL3370, Desmodur BL 3475, Desmodur BL 4265, Desmodur PL 340, Desmodur VP LS 2078, Desmodur VP LS 2117, and Desmodur VP LS 2352 (Desmodur materials are available from Bayer Corp., Pittsburgh, PA, USA), or combinations thereof.
  • trimers may include a trimerization product prepared from on average three diisocyanate molecules or a trimer prepared from on average three moles of diisocyanate (e.g., HMDI) reacted with one mole of another compound such as, for example, a triol (e.g., trimethylolpropane).
  • HMDI diisocyanate
  • a triol e.g., trimethylolpropane
  • Suitable blocking agents include malonates, such as ethyl malonate and diisopropyl malonte, acetylacetone, ethyl acetoacetate, l-phenyl-3-methyl-5-pyrazolone, pyrazole, 3-methyl pyrazole, 3,5 dimethyl pyrazole, hydroxylamine, thiophenol, caprolactam, pyrocatechol, propyl mercaptan, N-methyl aniline, amines such as diphenyl amine and diisopropyl amine, phenol, 2,4-diisobutylphenol, methyl ethyl ketoxime, .alpha.- pyrrolidone, alcohols such as methanol, ethanol, butanol and t-butyl alcohol, ethylene imine, propylene imine, benzotriazoles such as benzotriazole, 5-methylbenzotriazole,
  • the level of curing agent i.e., crosslinker
  • the crosslinker is typically present in an amount of up to 50 wt-%, preferably up to 30 wt-%, and more preferably up to 15 wt-%.
  • the crosslinker is typically present in an amount of at least 0.1 wt-%, more preferably at least 1 wt-%, and even more preferably at least 1.5 wt-%. These weight percentages are based upon the total weight of the resin solids in the coating composition.
  • the coating composition of the invention includes at least 5 wt-% of blocked polymeric isocyanates, more preferably from about 5 to about 20 wt-% of blocked polymeric isocyanates, and even more preferably from about 10 to about 15 wt-% of blocked polymeric isocyanates.
  • a coating composition of the present invention may also include other optional polymers that do not adversely affect the coating composition or a cured coating
  • Such optional polymers are typically included in a coating composition as a filler material, although they can be included as a crosslinking material, or to provide desirable properties.
  • One or more optional polymers e.g., filler polymers
  • Such additional polymeric materials can be nonreactive, and hence, simply function as fillers.
  • Such optional nonreactive filler polymers include, for example, polyesters, acrylics, polyamides, polyethers, and novalacs.
  • additional polymeric materials or monomers can be reactive with other components of the composition (e.g., the acid- functional polymer).
  • reactive polymers can be incorporated into the compositions of the present invention, to provide additional functionality for various purposes, including crosslinking.
  • examples of such reactive polymers include, for example, functionalized polyesters, acrylics, polyamides, and polyethers.
  • Preferred optional polymers are substantially free of mobile BPA and aromatic glycidyl ether compounds (e.g., BADGE, BFDGE and epoxy novalacs).
  • a coating composition of the present invention may also include other optional ingredients that do not adversely affect the coating composition or a cured coating composition resulting therefrom.
  • Such optional ingredients are typically included in a coating composition to enhance composition esthetics, to facilitate manufacturing, processing, handling, and application of the composition, and to further improve a particular functional property of a coating composition or a cured coating composition resulting therefrom.
  • Such optional ingredients include, for example, catalysts, dyes, pigments, toners, extenders, fillers, lubricants, anticorrosion agents, flow control agents, thixotropic agents, dispersing agents, antioxidants, adhesion promoters, light stabilizers, surfactants, and mixtures thereof.
  • Each optional ingredient is included in a sufficient amount to serve its intended purpose, but not in such an amount to adversely affect a coating composition or a cured coating composition resulting therefrom.
  • One preferred optional ingredient is a catalyst to increase the rate of cure.
  • catalysts include, but are not limited to, strong acids (e.g., dodecylbenzene sulphonic acid (DDBSA, available as CYCAT 600 from Cytec), methane sulfonic acid (MSA), p-toluene sulfonic acid (pTSA), dinonylnaphthalene disulfonic acid (DNNDSA), and triflic acid), quaternary ammonium compounds, phosphorous compounds, and tin and zinc compounds.
  • strong acids e.g., dodecylbenzene sulphonic acid (DDBSA, available as CYCAT 600 from Cytec
  • MSA methane sulfonic acid
  • pTSA p-toluene sulfonic acid
  • DNNDSA dinonylnaphthalene disulfonic acid
  • triflic acid triflic acid
  • a catalyst is preferably present in an amount of at least 0.01 wt-%, and more preferably at least 0.1 wt-%, based on the weight of nonvolatile material. If used, a catalyst is preferably present in an amount of no greater than 3 wt-%, and more preferably no greater than 1 wt-%, based on the weight of nonvolatile material.
  • a lubricant e.g., a wax
  • Preferred lubricants include, for example, Carnauba wax and polyethylene type lubricants.
  • a lubricant is preferably present in the coating composition in an amount of at least 0.1 wt-%, and preferably no greater than 2 wt-%, and more preferably no greater than 1 wt-%, based on the weight of nonvolatile material.
  • Another useful optional ingredient is a pigment, such as titanium dioxide. If used, a pigment is present in the coating composition in an amount of no greater than 70 wt-%, more preferably no greater than 50 wt-%, and even more preferably no greater than 40 wt-%, based on the total weight of solids in the coating composition.
  • Surfactants can be optionally added to the coating composition to aid in flow and wetting of the substrate.
  • examples of surfactants include, but are not limited to, nonylphenol polyethers and salts and similar surfactants known to persons skilled in the art. If used, a surfactant is preferably present in an amount of at least 0.01 wt-%, and more preferably at least 0.1 wt-%, based on the weight of resin solids. If used, a surfactant is preferably present in an amount no greater than 10 wt-%, and more preferably no greater than 5 wt-%, based on the weight of resin solids.
  • the coating composition of the invention preferably includes water and may further include one or more optional organic solvents.
  • the coating composition includes at least about 20 wt-%, more preferably at least about 25 wt-%, and even more preferably at least about 30 wt-% of water, based on the weight of the coating composition.
  • the coating composition includes less than about 60 wt-%, more preferably less than about 50 wt-%, and even more preferably less than about 40 wt-% of water, based on the weight of the coating composition.
  • the coating composition preferably includes one or more organic solvents in an amount of at least about 10 wt-%, more preferably at least about 20, and even more preferably at least about 25 wt-%, based on the weight of the coating composition. In some embodiments, the coating composition includes less than about 70 wt-%, more preferably less than about 60 wt-%, and even more preferably less than about 45 wt-% of organic solvent, based on the weight of the coating composition. While not intending to be bound by any theory, the inclusion of a suitable amount of organic solvent is advantageous for certain coil coating applications to modify flow and leveling of the coating composition, control blistering, and maximize the line speed of the coil coater. Moreover, vapors generated from evaporation of the organic solvent during cure of the coating may be used to fuel the curing ovens.
  • the coating composition preferably has a total solids content of from about 10 to about 70 wt-%, more preferably from about 20 to about 50 wt-%, and even more preferably from about 30 to about 40 wt-%, based on the weight of the coating composition.
  • the coating composition includes 5-65 wt-% of the latex polymer (more preferably 15-55 wt-%, even more preferably 25-45 wt-%), 20-60 wt-% of water (more preferably 25-50 wt-%, even more preferably 30-40 wt-%), and 10-70 wt-% of organic solvent (more preferably 20-60 wt-%, even more preferably 25-45 wt-%).
  • the coating compositions of the present invention are particularly well adapted for use on food and beverage cans (e.g., two-piece cans, three-piece cans, etc.). Two-piece cans are manufactured by joining a can body (typically a drawn metal body) with a can end (typically a drawn metal end).
  • the coatings of the present invention are suitable for use in food or beverage contact situations and may be used on the inside of such cans. They are particularly suitable for spray applied, liquid coatings for the interior of two- piece drawn and ironed beverage cans and coil coatings for beverage can ends.
  • the present invention also offers utility in other applications. These additional applications include, but are not limited to, wash coating, sheet coating, and side seam coatings (e.g., food can side seam coatings).
  • the coating composition may also be useful in medical packaging applications, including, for example, on surfaces of metered-dose inhalers
  • MDIs drug-contact surfaces
  • Spray coating includes the introduction of the coated composition into the inside of a preformed packaging container.
  • Typical preformed packaging containers suitable for spray coating include food cans, beer and beverage containers, and the like.
  • the spray preferably utilizes a spray nozzle capable of uniformly coating the inside of the preformed packaging container.
  • the sprayed preformed container is then subjected to heat to remove the residual solvents and harden the coating.
  • a coil coating is described as the coating of a continuous coil composed of a metal (e.g., steel or aluminum). Once coated, the coating coil is subjected to a short thermal, ultraviolet, and/or electromagnetic curing cycle, for hardening (e.g., drying and curing) of the coating.
  • Coil coatings provide coated metal (e.g., steel and/or aluminum) substrates that can be fabricated into formed articles, such as two-piece drawn food cans, three-piece food cans, food can ends, drawn and ironed cans, beverage can ends, and the like.
  • a wash coating is commercially described as the coating of the exterior of two- piece drawn and ironed ("D&I") cans with a thin layer of protectant coating.
  • the exterior of these D&I cans are "wash-coated” by passing pre-formed two-piece D&I cans under a curtain of a coating composition.
  • the cans are inverted, that is, the open end of the can is in the "down” position when passing through the curtain.
  • This curtain of coating composition takes on a "waterfall-like" appearance. Once these cans pass under this curtain of coating composition, the liquid coating material effectively coats the exterior of each can.
  • each can is passed through a thermal, ultraviolet, and/or electromagnetic curing oven to harden (e.g., dry and cure) the coating.
  • the residence time of the coated can within the confines of the curing oven is typically from 1 minute to 5 minutes.
  • the curing temperature within this oven will typically range from 150 0 C to 220 0 C.
  • a sheet coating is described as the coating of separate pieces of a variety of materials (e.g., steel or aluminum) that have been pre-cut into square or rectangular "sheets.” Typical dimensions of these sheets are approximately one square meter. Once coated, each sheet is cured.
  • Sheet coatings provide coated metal (e.g., steel or aluminum) substrate that can be successfully fabricated into formed articles, such as two-piece drawn food cans, three-piece food cans, food can ends, drawn and ironed cans, beverage can ends, and the like.
  • a side seam coating is described as the spray application of a liquid coating over the welded area of formed three-piece food cans.
  • a rectangular piece of coated substrate is formed into a cylinder.
  • the formation of the cylinder is rendered permanent due to the welding of each side of the rectangle via thermal welding.
  • each can typically requires a layer of liquid coating, which protects the exposed "weld” from subsequent corrosion or other effects to the contained foodstuff.
  • the liquid coatings that function in this role are termed "side seam stripes.” Typical side seam stripes are spray applied and cured quickly via residual heat from the welding operation in addition to a small thermal, ultraviolet, and/or electromagnetic oven.
  • Preferred coatings of the present invention display one or more of the properties described in the Examples Section. More preferred coatings of the present invention display one or more of the following properties: metal exposure value of less than 3 mA; metal exposure value after drop damage of less than 3.5 mA; global extraction results of less than 50 ppm; adhesion rating of 10; blush rating of at least 7; slight or no crazing in a reverse impact test; no craze (rating of 10) in a dome impact test; feathering below 0.2 inch; COF range of 0.055 to 0.095; an initial end continuity of less than 10 mA (more preferably less than 5, 2, or 1 mA); and after pasteurization or retort, a continuity of less than 20 mA.
  • the curing conditions involve maintaining the temperature measured at the can dome at 188°C to 199°C for 30 seconds.
  • the curing conditions involve the use of a temperature sufficient to provide a peak metal temperature within the specified time (e.g., 10 seconds at 204 0 C means 10 seconds, in the oven, for example, and a peak metal temperature achieved of 204 0 C).
  • This test method determines the amount of the inside surface of the can that has not been effectively coated by the sprayed coating. This determination is made thorough the use of an electrically conductive solution (1% NaCl in deionized water). The coated can is filled with this room-temperature conductive solution, and an electrical probe is attached in contact to the outside of the can (uncoated, electrically conducting). A second probe is immersed in the salt solution in the middle of the inside of the can. If any uncoated metal is present on the inside of the can, a current is passed between these two probes and registers as a value on an LED display. The LED displays the conveyed currents in milliamps (mA).
  • mA milliamps
  • the current that is passed is directly proportional to the amount of metal that has not been effectively covered with coating.
  • the goal is to achieve 100% coating coverage on the inside of the can, which would result in an LED reading of 0.0 mA.
  • Preferred coatings give metal exposure values of less than 3 mA, more preferred values of less than 2 mA, and even more preferred values of less than 1 mA.
  • Commercially acceptable metal exposure values are typically less than 2.0 mA on average.
  • Drop damage resistance measures the ability of the coated container to resist cracks after being in conditions simulating dropping of a filled can.
  • the presence of cracks is measured by passing electrical current via an electrolyte solution, as previously described in the Metal Exposure section.
  • a coated container is filled with the electrolyte solution and the initial metal exposure is recorded.
  • the can is then filled with water and dropped through a tube from a specified height onto an inclined plane, causing a dent in the chime area.
  • the can is then turned 180 degrees, and the process is repeated. Water is then removed from the can and metal exposure is again measured as described above. If there is no damage, no change in current (mA) will be observed. Typically, an average of 6 or 12 container runs is recorded.
  • Preferred coatings give metal exposure values after drop damage of less than 3.5 mA, more preferred valued of less than 2.5 mA, and even more preferred values of less than 1.5 mA.
  • the extent of "cure” or crosslinking of a coating is measured as a resistance to solvents, such as methyl ethyl ketone (MEK, available from Exxon, Newark, NJ) or isopropyl alcohol (IPA). This test is performed as described in ASTM D 5402 - 93. The number of double-rubs (i.e., one back-and forth motion) is reported.
  • solvents such as methyl ethyl ketone (MEK, available from Exxon, Newark, NJ) or isopropyl alcohol (IPA).
  • the global extraction test is designed to estimate the total amount of mobile material that can potentially migrate out of a coating and into food packed in a coated can.
  • coated substrate is subjected to water or solvent blends under a variety of conditions to simulate a given end use.
  • Acceptable extraction conditions and media can be found in 21CFR 175.300 paragraphs (d) and (e).
  • the allowable global extraction limit as defined by the FDA regulation is 50 parts per million (ppm).
  • the coated beverage can was filled with 10 weight percent aqueous ethanol and subjected to pasteurization conditions (150 0 F) for 2 hours, followed by a 10-day equilibrium period at 100 0 F. Determination of the amount of extractives was determined as described in 2 ICFR 175.300 paragraph (e) (5), and ppm values were calculated based on surface area of the can (no end) of 44 square inches with a volume of 355 ml.
  • Preferred coatings give global extraction results of less than 50 ppm, more preferred results of less than 10 ppm, even more preferred results of less than 1 ppm. Most preferably, the global extraction results are optimally non-detectable.
  • Adhesion testing is performed to assess whether the coating adheres to the coated substrate.
  • the adhesion test was performed according to ASTM D 3359 - Test Method B, using SCOTCH 610 tape, available from 3M Company of Saint Paul, Minnesota.
  • Adhesion is generally rated on a scale of 0-10 where a rating of "10" indicates no adhesion failure, a rating of "9” indicates 90% of the coating remains adhered, a rating of "8” indicates 80% of the coating remains adhered, and so on. Adhesion ratings of 10 are typically desired for commercially viable coatings.
  • Blush resistance measures the ability of a coating to resist attack by various solutions. Typically, blush is measured by the amount of water absorbed into a coated film. When the film absorbs water, it generally becomes cloudy or looks white. Blush is generally measured visually using a scale of 0-10 where a rating of "10" indicates no blush and a rating of "0" indicates complete whitening of the film. Blush ratings of at least 7 are typically desired for commercially viable coatings and optimally 9 or above.
  • the reverse impact measures the coated substrate's ability to withstand the deformation encountered when impacted by a steel punch with a hemispherical head.
  • coated substrate was subjected to 12 in-lbs (1.36 N m) of feree using BYK-Gardner "overall" Bend and Impact Tester and rated visually for micro-cracking or micro-fracturing - commonly referred to as crazing. Test pieces were impacted on the uncoated or reverse side. A rating of 10 indicates no craze and suggests sufficient flexibility and cure. A rating of 0 indicates complete failure. Commercially viable coatings preferably show slight or no crazing on a reverse impact test.
  • Dome impact was evaluated by subjecting the dome apex of a 12 oz. beverage can to a reverse impact as described in the previous section. Craze was evaluated after impact. A rating of 10 indicates no craze and suggests sufficient flexibility and cure. A rating of 0 indicates complete failure. Coatings for beverage can interiors preferably show no craze (rating of 10) on a dome impact.
  • a 1% solution of JOY Detergent (available from Procter & Gamble) in deionized water is prepared and heated to 82°C (180 0 F). Coated panels are immersed in the heated solution for 10 minutes and then removed, rinsed, and dried. Samples are then evaluated for adhesion and blush, as previously described. Commercially viable beverage interior coatings preferably give adhesion ratings of 10 and blush ratings of at least 7, optimally at least 9, in the detergent test.
  • Feathering is a term used to describe the adhesion loss of a coating on the tab of a beverage can end. When a beverage can is opened, a portion of free film may be present across the opening of the can if the coating loses adhesion on the tab. This is feathering.
  • a "tab" is scored on the backside of a coated panel, with the coated side of the panel facing downward.
  • the test piece is then pasteurized as described under the Pasteurization section below.
  • the "Dowfax" test is designed to measure the resistance of a coating to a boiling detergent solution. This is a general test run for beverage end coatings and is mainly used to evaluate adhesion. Historically, this test was used to indicate problems with the interaction of coating to substrate pretreatment.
  • the solution is prepared by mixing 5 ml of Dowfax 2Al (product of Dow Chemical) into 3000 ml of deionized water. Typically, coated substrate strips are immersed into the boiling Dowfax solution for 15 minutes. The strips are then rinsed and cooled in deionized water, dried, and then tested and rated for blush and adhesion as described previously.
  • Preferred beverage end coatings provide adhesion ratings of 10 and blush ratings of at least 4, more preferably 6 or above in the Dowfax detergent test.
  • the sterilization or pasteurization test determines how a coating withstands the processing conditions for different types of food products packaged in a container.
  • a coated substrate is immersed in a water bath and heated for 5-60 minutes at temperatures ranging from 65°C to 100 0 C.
  • the coated substrate was immersed in a deionized water bath for 45 minutes at 85°C.
  • the coated substrate was then removed from the water bath and tested for coating adhesion and blush as described above.
  • Commercially viable coatings preferably provide adequate pasteurization resistance with perfect adhesion (rating of 10) and blush ratings of at least 5, optimally at least 9.
  • Coefficient of friction is a measurement of lubricity of a coating and is used to give an indication of how a cured coating will perform on commercial fabrication equipment and presses. Typically, lubricants are added to coatings requiring aggressive post application fabrication to give the appropriate lubricity.
  • This test measures the ability of a coated substrate to retain its integrity as it undergoes the formation process necessary to produce a beverage can end. It is a measure of the presence or absence of cracks or fractures in the formed end.
  • the end is typically placed on a cup filled with an electrolyte solution. The cup is inverted to expose the surface of the end to the electrolyte solution. The amount of electrical current that passes through the end is then measured. If the coating remains intact (no cracks or fractures) after fabrication, minimal current will pass through the end.
  • Preferred coatings of the present invention initially pass less than 10 milliamps (mA) when tested as described above, more preferably less than 5 mA, most preferably less than 2 mA, and optimally less than 1 mA. After pasteurization or retort, preferred coatings give continuities of less than 20 mA, more preferably less than 10 mA, even more preferably less than 5 mA, and even more preferably less than 2 mA.
  • a premix of 512.6 parts glacial methacrylic acid (MAA), 512.6 parts butyl acrylate (BA), 114.0 parts styrene, and 73.2 parts benzoyl peroxide (70% water wet) was prepared in a separate vessel.
  • a 3 -liter flask was equipped with a stirrer, reflux condenser, thermocouple, heating mantle, and nitrogen blanket.
  • Ten percent of the premix was added to the flask along with 405.9 parts butanol and 30.6 parts deionized water.
  • To the remaining premix were added 496.1 parts butanol and 38.3 parts deionized water. With the nitrogen blanket flowing in the flask, the contents were heated to 93 0 C.
  • a premix of 677.7 parts glacial methacrylic acid, 677.7 parts butyl methacrylate (BMA), 150.8 parts styrene, and 96.9 parts benzoyl peroxide (70% water wet) was prepared in a separate vessel.
  • a 5-liter flask was equipped with a stirrer, reflux condenser, thermocouple, heating mantle, and nitrogen blanket.
  • Ten percent of the premix was added to the flask along with 536.9 parts butanol and 40.7 parts deionized water.
  • To the remaining premix were added 758.1 parts butanol and 50.6 parts deionized water. With the nitrogen blanket flowing in the flask, the contents were heated to 93 0 C.
  • a second premix containing 59.2 parts butanol and 16.1 parts t-butyl peroctoate was prepared. When the addition of the first premix was complete the second premix was added over 30 minutes. Once complete, the batch was held for 30 minutes. A chase of 3.4 parts t-butyl peroctoate was added and the batch held for 2 hours. After the 2-hour hold time, the heat was discontinued and the batch cooled. The resulting acrylic prepolymer was 50.1% NV, with an acid number of 292 and a Brookfield viscosity of 150,000 cps.
  • a premix of 802.6 parts glacial methacrylic acid, 445.9 parts ethyl acrylate, 535.1 parts styrene, 108.6 parts t-butyl peroctoate, 838.5 parts butanol, and 59.9 parts deionized water was prepared in a separate vessel.
  • a 5-liter flask was equipped with a stirrer, reflux condenser, thermocouple, heating mantle, and nitrogen blanket. Added to the 5 -liter flask was 635.8 parts butanol and 48.1 parts deionized water. The flask was heated to 94 0 C. At 94 0 C, 16.6 parts t-butyl peroctoate was added.
  • the batch was held for 5 minutes after which the premix was added over 2.5 hours.
  • a second premix containing 59.2 parts butanol and 21.2 parts t-butyl peroctoate was prepared. When the addition of the first premix was complete, the second premix was added over 30 minutes. Once complete, the batch was held for 30 minutes. A chase of 4.6 parts t-butyl peroctoate was added and the batch held for 2 hours. After the 2-hour hold, the heat was discontinued and the batch cooled.
  • the resulting acrylic prepolymer was 49.8% NV, with an acid number of 303 and a Brookfield viscosity of 21,650 cps.
  • a premix of 803.4 parts glacial methacrylic acid, 446.3 parts ethyl acrylate (EA), 535.5 parts styrene, 153 parts benzoyl peroxide (70% water wet), 839.2 parts butanol, and 60 parts deionized water was prepared in a separate vessel.
  • a 5-liter flask was equipped with a stirrer, reflux condenser, thermocouple, heating mantle and nitrogen blanket.
  • 636.3 parts butanol and 48.2 parts deionized water were added and heated to 97 0 C to 100 0 C with a nitrogen blanket flowing in the flask.
  • the premix was added uniformly over 2.5 hours maintaining 97 0 C to 100 0 C.
  • the premix vessel When the premix was in, the premix vessel was rinsed with 59.2 parts butanol and added to the flask. The batch was held at temperature for 2 hours. The heating was discontinued and the batch cooled. The resulting acrylic prepolymer was 50.2% NV, with an acid number of 301 and a Brookfield viscosity of 25,400 cps.
  • Example 1 A 3-liter flask was equipped with a stirrer, reflux condenser, Dean Stark Tube, thermocouple, heating mantle, and nitrogen blanket. Into the flask was added 711.5 parts of Example 1: Run 1 acrylic, 762.9 parts deionized water, and 56.9 parts dimethyl ethanol amine (DMEA). The contents were heated to reflux and 553 parts were distilled from the flask. After distillation was complete, 598 parts of deionized water were added. The batch was cooled giving an acrylic solution at 20.3% solids and 307 acid number.
  • DMEA dimethyl ethanol amine
  • Example 1 A 5-liter flask was equipped with a stirrer, reflux condenser, Dean Stark Tube, thermocouple, heating mantle, and nitrogen blanket. Into the flask was added 1853 parts of Example 1: Run 2 acrylic, 2220.4 parts deionized water, and 163.3 parts dimethyl ethanol amine. The contents were heated to reflux and 1587 parts were distilled from the flask. After distillation was complete, 1718 parts of deionized water were added. The batch was cooled giving an acrylic solution at 22.2% solids, 294 acid number, pH of 6.0, and a viscosity of 13 seconds (Number 4 Ford cup viscosity as determined by ASTM D- 1200).
  • Example 1 Run 3 acrylic, 2219 parts deionized water, and 163 parts dimethyl ethanol amine. The contents were heated to reflux and 1463 parts were distilled from the flask. After distillation was complete, 1581 parts of deionized water were added. The batch was cooled giving an acrylic solution at 21.6% solids, 284 acid number, pH of 6.23 and a viscosity of 13 seconds (Number 4 Ford cup).
  • Example 1 A 5-liter flask was equipped with a stirrer, reflux condenser, Dean Stark Tube, thermocouple, heating mantle, and nitrogen blanket. Into the flask was added 1799.2 parts of Example 1 : Run 4 acrylic, 2155.9 parts deionized water, and 158.6 parts dimethyl ethanol amine. The contents were heated to reflux and 1541 parts were distilled from the flask. After distillation was complete, 1615 parts of deionized water were added. The batch was cooled giving an acrylic solution at 22.1% solids, 302 acid number, pH of 6.55 and a Brookfield viscosity of 2060 cps.
  • Example 2 Using techniques from Example 2: Run 4 the systems shown in Table 3 were prepared. Each run of Example 2 used the correspondingly numbered run from Example 1. That is, Example 2: Run 5 used the acrylic prepolymer from Example 1: Run 5, etc.
  • a 1 -liter flask was equipped with a stirrer, reflux condenser, thermocouple, heating mantle, and nitrogen blanket.
  • Example 2 Run 3 salt and 267.3 parts deionized water.
  • the contents of the flask were heated to 75 0 C at 280 revolutions per minute (RPM).
  • RPM revolutions per minute
  • a premix of 71.4 parts styrene, 116.3 parts butyl methacrylate, and 16.3 parts glycidyl methacrylate (GMA) was prepared. Once the flask was at 75 0 C, 10% of the premix was added followed by 2.04 parts benzoin and 20 parts deionized water.
  • the flask was heated further to 79 0 C. At 79 0 C, 2.04 parts of 35% hydrogen peroxide was added and held for 5 minutes. After 5 minutes, the temperature control was set at 81 0 C and the remaining premix was added over a period of 1 hour. When the addition was complete, 20 parts deionized water were used to rinse the residual premix into the flask. The batch was held for 10 minutes and then 0.35 parts benzoin, 20 parts deionized water, and 0.35 parts 35% hydrogen peroxide were added. After 2 hours the heat was removed and the batch cooled. This gave an emulsion at 31.9% solids, 63.3 acid number, pH of 6.48, and a Brookfield viscosity of 203 cps.
  • a 0.5-liter flask was equipped with a stirrer, reflux condenser, thermocouple, heating mantle, and nitrogen blanket.
  • Example 2 Run 4 salt and 120.6 parts deionized water.
  • the contents of the flask were heated to 75 0 C at 240 RPM.
  • a premix of 66.3 parts styrene, 19.6 parts ethyl acrylate, and 7.5 parts glycidyl methacrylate was prepared. Once the flask was at 75 0 C, 10% of the premix was added followed by 0.91 parts benzoin and 9.4 parts deionized water. The flask was heated further to 79 0 C.
  • a 1 -liter flask was equipped with a stirrer, reflux condenser, thermocouple, heating mantle, and nitrogen blanket.
  • Example 2 Run 4 salt and 241.2 parts deionized water.
  • the contents of the flask were heated to 75 0 C at 270 RPM.
  • a premix of 112.1 parts styrene, 59.8 parts ethyl acrylate, and 14.9 parts glycidyl methacrylate was prepared.
  • 10% of the premix was added followed by 1.87 parts benzoin and 18.8 parts deionized water.
  • the flask was heated further to 79 0 C.
  • a 5-liter flask was equipped with a stirrer, reflux condenser, thermocouple, heating mantle, and nitrogen blanket.
  • Into the flask was added 1525.0 parts of Example 2: Run 4 salt and 1219.1 parts deionized water.
  • the contents of the flask were heated to 7O 0 C at 250 RPM.
  • a premix of 380.4 parts styrene, 278.3 parts butyl acrylate (BA), 194.9 parts butyl methacrylate, and 74.2 parts glycidyl methacrylate was prepared. Once the flask was at 7O 0 C, 10% of the premix was added followed by 9.29 parts benzoin and 92.9 parts deionized water.
  • the flask was heated further to 79 0 C. At 79 0 C, 9.29 parts of 35% hydrogen peroxide were added and held for 5 minutes. After 5 minutes, the temperature control was set at 81 0 C and the remaining premix was added over 1 hour. When the addition was complete, 92.9 parts deionized water were used to rinse the residual premix into the flask. The batch was held for 10 minutes and then 1.59 parts benzoin, 92.9 parts deionized water, and 1.59 parts 35% hydrogen peroxide were added. The batch was held for 45 minutes and then 0.52 parts benzoin and 0.52 parts 35% hydrogen peroxide were added. After 2 hours, the heat was removed and the batch cooled. This gave an emulsion at 31.4% solids, 64.1 acid number, pH of 6.95, and a viscosity of 22 seconds (Number 4 Ford cup).
  • a 12-liter flask was equipped with a stirrer, reflux condenser, thermocouple, heating mantle, and nitrogen blanket.
  • Into the flask was added 3886.5 parts of Example 2: Run 4 salt and 3022.5 parts deionized water.
  • the contents of the flask were heated to 7O 0 C at 235 RPM.
  • a premix of 771.25 parts styrene, 933.75 parts butyl acrylate, 537.5 parts butyl methacrylate, and 93.75 parts glycidyl methacrylate was prepared.
  • Example 2 Run 4 as the acid functional acrylic salt and the process outlined above was prepared and is depicted in Table 7.
  • Example 3 Run 5b was included as one of the variables and was a repeat of Run 5.
  • a series of emulsions, shown in Table 11 were prepared using a monomer to acid-functional acrylic ratio of 73/27 solids/solids. These systems were prepared using the process outlined in Example 3: Run 5 using Example 2: Run 4 as the acid- functional acrylic salt.
  • Results from Table 13 indicate the optimum level of IBMA in the emulsion monomer composition is around 5%, when used in conjunction with hydroxyl functionality in the acrylic polymer stabilizer.
  • Example 4 Runs 1-2 - Spray Application
  • Example 3 The water-based emulsion of Example 3: Run 4 was successfully formulated into a spray applied coating for the interior of beer/beverage aluminum cans. The product was formulated with or without additional surfactant, as described in Table 14.
  • Example 3 The water-based emulsion of Example 3: Run 4 and Example 3: Run 7 were successfully formulated into spray applied coatings for the interior of beer/beverage aluminum cans. Coating compositions are shown in Table 16.
  • Example 3 In ajar with an agitator, 483.25 parts of Example 3: Run 5 emulsion was stirred with 16.75 parts SLIPAYD 404 wax. The mixture was stirred for 10 minutes to make it uniform. The mixture was then filtered. The mixture was approximately 31% solids. The mixture was applied at 7-8 milligrams per square inch (msi) (1.1-1.25 mg/cm ) on ALX Alcoa aluminum and baked for 10 seconds (sec) to achieve a 400°F (204 0 C) peak metal temperature in a coil oven.
  • msi milligrams per square inch
  • Example 5 Using the process of Example 5: Run 1, the formulations shown in Table 19 were prepared to investigate the effect of GMA level on end continuities. Each formula was applied at 7-8 msi (1.1 - 1.25 mg/cm 2 ) on ALX Alcoa aluminum and baked for 10 seconds to achieve a 420°F (215°C) peak metal temperature in a coil oven. End continuities are shown in Table 20. Table 19: Effect of GMA Level
  • a phenol-formaldehyde phenolic at 50% in water prepared by reacting 2.3 moles of formaldehyde with 1 mole of phenol.
  • Example 5 Using the process of Example 5: Run 1, the formulation shown in Table 21 was prepared. The formula was applied at 7-8 milligrams per square inch (msi) (1.1-1.25 mg/cm 2 ) on ALX Alcoa aluminum and baked for 10 seconds to achieve 400 0 F (204 0 C) and 420 0 F (215°C) peak metal temperatures in a coil oven. Film and end performance properties are shown in Table 22. This material contains 4% GMA and 5% IBMA in the emulsion monomer mix and an acrylic composition with hydroxyl functionality. Table 21 : Beverage End Formulation
  • Example 6 is designed to illustrate the use of a different acid-functional polymer salt as the stabilizer for an emulsion of the present invention.
  • a 2-liter flask was equipped with a stirrer, packed column, Dean Stark trap, reflux condenser, thermocouple, heating mantle and nitrogen blanket.
  • To the flask 700.1 parts dipropylene glycol and 700.1 parts isophthalic acid were added. Under a nitrogen blanket, the contents were heated to 125°C. At 125°C, 1.05 parts FASCAT 4201 was added.
  • the temperature was increased to remove water.
  • water was beginning to collect.
  • thermocouple heating mantle, and nitrogen blanket.
  • Into the flask was added 93.2 parts of the Stage C material and 179 parts deionized water. While the contents of the flask were being heated to 50 0 C at 240 RPM, 2 drops of HAMP-OL 4.5% Iron and 1.11 parts erythorbic acid were added.
  • a premix of 28.8 parts styrene, 50.9 BA, 21.0 parts BMA, 5.6 parts IBMA, 4.5 parts GMA and 1.11 parts TRIGONOX A-W70 were premixed. Once the flask was at 52°C, 10% of the premix was added and held for 5 minutes.
  • a 3-liter flask was equipped with a stirrer, reflux condenser, thermocouple, heating mantle, and nitrogen blanket.
  • Into the flask was added 392.2 parts of Example 1 : Run 4 acid- functional acrylic, 86.4 parts deionized water, 34.6 parts DMEA, and 1120.8 parts deionized water.
  • the contents of the flask were heated to 7O 0 C.
  • a premix of 215.8 parts styrene, 302.7 parts butyl acrylate, and 42.0 parts glycidyl methacrylate was prepared. Once the flask was at 7O 0 C, 5.5 parts benzoin and 27.8 parts deionized water were added, followed by 10% of the premix.
  • the flask was heated further to 79 0 C and when this temperature was reached, 5.5 parts of 35% hydrogen peroxide and 27.8 parts deionized water were added and held for 5 minutes.
  • the flask was stirred at 210 RPM. After 5 minutes, the temperature control was set at 81 0 C and the remaining premix was added over 1 hour. When the addition was complete, 55.9 parts deionized water were used to rinse the residual premix into the flask.
  • the batch was held for 10 minutes and then 0.96 parts benzoin, 55.9 parts deionized water, and 0.95 parts 35% hydrogen peroxide were added.
  • the batch was held for 45 minutes and then 0.31 parts benzoin and 0.31 parts 35% hydrogen peroxide were added.
  • Example 7 The water-based emulsion of Example 7 was successfully formulated into a spray applied coating for the interior of beer/beverage aluminum cans.
  • the product was formulated as described in Table 24.
  • This formulation was sprayed at typical laboratory conditions at 120 mg/can to 130 mg/can coating weight for the application of interior beverage coatings, and cured at
  • Example 9 Latex with Polyester-Poly ether Stabilizer
  • Example 9 illustrates the use of a different acid-functional polymer salt as the stabilizer for an emulsion of the present invention.
  • a flask was equipped with a stirrer, packed column, Dean Stark trap, reflux condenser, thermocouple, heating mantle and nitrogen blanket.
  • 809.8 parts sebacic acid and 1283.0 parts CHDM-90 (90% 1,4-cyclohexane dimethanol in water) were added. Under a nitrogen blanket, the contents were heated to distill the water from the
  • a 5 -liter flask was equipped with a stirrer, reflux condenser, thermocouple, heating mantle, and nitrogen blanket.
  • Into the flask was added 1183.4 parts of the Stage B material and 779.6 parts deionized water.
  • a premix of 7.25 parts erythorbic acid, 6.5 parts DMEA, and 76.7 parts deionized water was prepared. This initial premix and 0.18 parts HAMP-OL 4.5% Iron were added to the flask. The contents of the flask were heated to 30 0 C.
  • a monomer premix of 249.0 parts styrene, 113.8 BA, 106.7 parts BMA, 177.8 parts Hydroxy Ethyl Methacrylate (HEMA), 35.6 parts IBMA, and 28.5 parts GMA was prepared.
  • a third premix of 7.25 parts TRIGONOX A-W70 and 82.2 parts deionized water were made. Once all the premixes were prepared and the flask at 30 0 C, the stirrer was set at 240 RPM and all of the monomer premix was added. The monomer premix vessel was rinsed with 81.6 parts deionized water, which was also added to the flask.
  • the contents of the flask were stirred for 10 minutes, after which 10% of the third premix was added within 1 minute. Once the 10% of the third premix was in, the temperature was increased to 37°C and the batch was held for 5 minutes. After 5 minutes, the remaining amount of the third premix was added over 45 minutes. The temperature was allowed to increase with no external heat applied. During the addition the maximum temperature was 57°C. After the addition was complete the temperature was 51 0 C. Temperature control was set for 52°C. The third premix was rinsed with 108.4 parts deionized water and added to the batch. The batch was held for 1.5 hours and then cooled. This yielded an emulsion at 33.1% solids, 27.1 acid number, pH of 7.9, and a viscosity of 12 seconds (Number 4 Ford Cup).
  • the Stage D composition was applied to non-chrome aluminum panels and baked for 10 seconds to achieve a 420 0 F (215°C) peak metal temperature. A second set was baked for 10 seconds to achieve a 440 0 F (227°C) peak metal temperature. Results from beverage end testing of this example versus a commercial water base and solvent base control formulas are shown in Tables 26 and 27. Table 26: Comparative Testing of Example 9 Stage D Cured at 420 0 F (215°C)
  • Example 10 illustrates the use of a different acid-functional polymer salt as the stabilizer for an emulsion of the present invention.
  • a 5 -liter flask is equipped with a stirrer, reflux condenser, thermocouple, heating mantle, and nitrogen blanket.
  • Into the flask is added approximately 1183 parts of the Stage 1 material and 780 parts deionized water.
  • a premix of 7.25 parts erythorbic acid, 6.5 parts DMEA, and 77 parts deionized water is prepared. This initial premix and 0.18 parts HAMP- OL 4.5% Iron are added to the flask.
  • the contents of the flask are heated to 30 0 C.
  • a monomer premix of 249 parts styrene, 114 BA, 107 parts BMA, 178 parts HEMA, 36 parts IBMA, and 28 parts GMA is prepared.
  • TRIGONOX A-W70 and 82.2 parts deionized water is made. Once all the premixes are prepared and the flask is at 30 0 C, the stirrer is set at 240 RPM and all of the monomer premix is added. The monomer premix vessel is rinsed with 82 parts deionized water, which is also added to the flask. The contents of the flask are stirred for 10 minutes, after which 10% of the third premix is added within 1 minute. Once the 10% is in the temperature is increased to 37°C. The batch is held for 5 minutes. After 5 minutes, the remaining amount of the third premix is added over 45 minutes. The temperature is allowed to increase with no external heat applied. During the addition, the maximum temperature is 57°C.
  • the temperature is set for 52°C.
  • the third premix is rinsed with 109 parts deionized water and added to the batch.
  • the batch is held for 1.5 hours and cooled. This process should yield an emulsion with a target of approximately 33 % solids, 27 acid number, pH of 8, and a viscosity of 12 seconds (Number 4 Ford Cup).
  • This formulation should yield a composition having approximately
  • the Stage 3 composition may be applied to non-chrome aluminum panels and baked for 10 seconds to achieve a 217°C peak metal temperature.
  • initiator premix 1 Another premix (hereinafter "initiator premix 1”) was made in a separate container consisting of 316.3 grams of n-butanol and 113.7 grams of Luperox 26 (tert-butyl-peroxy-2-ethylhexenoate).
  • itiator premix 2 Another premix consisting of 8.2 grams of n-butanol and 17.6 grams of Luperox 26 was prepared.
  • initiator premix 2 was charged to the reaction flask and the monomer premix and initiator premix 1 feeds were then simultaneously started and fed into the reactor over a period of 2.5 hours.
  • initiator premix 3 another initiator premix
  • the initiator flask and lines were rinsed with 16.4 grams of n-butanol and the batch was held at 97°C to 100 0 C for 30 minutes.
  • the following monomer mixture was then added to the reaction flask: 89.9 grams of styrene, 126.1 grams of n-butyl acrylate, and 17.5 grams of glycidyl methacrylate. The temperature of the flask was allowed to drop. After mixing for approximately 30 minutes, 10.0 grams of deionized water and 0.4 grams of tert-butyl hydroperoxide were added to the reaction flask. Next, a premix of 0.3 grams of erythorbic acid, 0.3 grams of dimethylethanolamine, 0.025 grams of a 6.17% aqueous solution of sodium feredetate, and 25.0 grams of deionized water was fed into the reactor over 15 to 20 minutes.
  • peak 1 represents the "batch" polymerized latex component of the polymer and that peak 2 represents the alkali soluble support polymer.
  • the mixture was stirred for 10 minutes to make it uniform. The mixture was then filtered. The mixture was approximately 32 wt-% solids. The mixture was applied at 6-7 milligrams per square inch (msi) (0.94-1.10 mg/cm 2 ) on ALX Alcoa aluminum and baked for 10 seconds to achieve a 425 °F (218°C) peak metal temperature (PMT) in a coil oven.
  • msi milligrams per square inch
  • PMT peak metal temperature
  • Stepanpol PS-70L polyester (Stepan Corp., Northfield, IL, USA)
  • the mixture was then heated with an air sparge to 88 0 C and held at temperature for approximately 3 hours, after which substantially all of the hydroxyl groups had been reacted with isocyanate and an isocyanate terminated prepolymer was formed.
  • the prepolymer was then cooled to 6O 0 C and neutralized with 32.16 grams of triethylamine.
  • Michem Lube 160 PF carnauba wax emulsion available from Michelman, Cincinnati, OH, USA
  • 4.03 grams of a phenol-formaldehyde crosslinker The mixture was stirred for 10 minutes to make it uniform. The mixture was then filtered. The mixture was approximately 38.2 wt-% solids. The mixture was applied at 6-7 msi (0.94-1.10 mg/cm 2 ) on ALX Alcoa aluminum and baked for 10 seconds to achieve a 465°F (241°C) peak metal temperature (PMT) in a coil oven.
  • PMT peak metal temperature

Abstract

L'invention porte sur une composition de revêtement pour une boîte destinée à contenir des aliments ou une boisson. Cette composition comprend un polymère de latex polymérisé en émulsion formé par combinaison d'un composant monomère à insaturation éthylénique avec une dispersion aqueuse d'un polymère dispersible dans l'eau.
PCT/US2010/042226 2009-07-17 2010-07-16 Compositions de revêtement pour des boîtes et procédés de revêtement WO2011009024A1 (fr)

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US12/505,236 2009-07-17
US12/505,250 US8173265B2 (en) 2004-10-20 2009-07-17 Coating compositions for cans and methods of coating
US12/505,250 2009-07-17
US12/505,236 US8092876B2 (en) 2004-10-20 2009-07-17 Coating compositions for cans and methods of coating
US12/505,255 2009-07-17
US12/505,255 US8142868B2 (en) 2004-10-20 2009-07-17 Coating compositions for cans and methods of coating

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Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012162299A1 (fr) * 2011-05-23 2012-11-29 Ppg Industries Ohio, Inc. Compositions de revêtement pour récipients
US9029470B2 (en) 2009-02-24 2015-05-12 Akzo Nobel Coatings International B.V. Latex emulsions and coating compositions formed from latex emulsions
US9133292B2 (en) 2009-03-05 2015-09-15 Akzo Nobel Coatings International B.V. Hydroxyl functional oil polyol acrylic graft copolymers
US9181448B2 (en) 2010-12-29 2015-11-10 Akzo Nobel Coatings International B.V. Latex emulsions and coating compositions formed from latex emulsions
US9260625B2 (en) 2011-12-21 2016-02-16 Akzo Nobel Coatings International B.V. Water-based coating compositions
US9273226B2 (en) 2011-12-21 2016-03-01 Akzo Nobel Coatings International B.V. Solvent-based coating compositions
US9394456B2 (en) 2009-02-24 2016-07-19 Akzo Nobel Coatings International B.V. Latex emulsions and coating compositions formed from latex emulsions
US9458345B2 (en) 2010-12-28 2016-10-04 Akzo Nobel Coatings International B.V. Coating compositions comprising latex emulsions and hydroxyl functional oil polyol graft copolymers
WO2017180895A1 (fr) * 2016-04-15 2017-10-19 Valspar Sourcing, Inc. Copolymères sans styrène et compositions de revêtement contenant de tels copolymères
WO2017198936A1 (fr) * 2016-05-20 2017-11-23 Constellium Neuf-Brisach Bande metalloplastique pour emballage alimentaire rigide et procédé de fabrication
WO2018013766A1 (fr) * 2016-07-15 2018-01-18 Valspar Sourcing, Inc. Composition de revêtement en latex ayant des propriétés de réduction de l'arôme réduites
WO2019040823A1 (fr) * 2017-08-25 2019-02-28 The Sherwin-Williams Company Promoteurs d'adhésion et compositions pour récipients et autres articles
US10800941B2 (en) 2014-12-24 2020-10-13 Valspar Sourcing, Inc. Coating compositions for packaging articles such as food and beverage containers
US10968288B2 (en) 2014-12-24 2021-04-06 Swimc Llc Styrene-free coating compositions for packaging articles such as food and beverage containers
US11059989B2 (en) 2017-06-30 2021-07-13 Valspar Sourcing, Inc. Crosslinked coating compositions for packaging articles such as food and beverage containers
US11427654B2 (en) 2017-09-01 2022-08-30 Swimc Llc Multi-stage polymeric latexes, coating compositions containing such latexes, and articles coated therewith
US11466162B2 (en) 2017-09-01 2022-10-11 Swimc Llc Multi-stage polymeric latexes, coating compositions containing such latexes, and articles coated therewith
US11602768B2 (en) 2016-10-19 2023-03-14 Swimc, Llc Acrylic polymers and compositions containing such polymers

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020176994A1 (en) * 2001-02-27 2002-11-28 Shalati Mohamad Deeb Reactive non-isocyanate coating compositions
US20050277569A1 (en) * 2004-06-14 2005-12-15 Goodall Brian L Catalytic composition and its preparation and use for preparing polymers from ethylenically unsaturated monomers
US20060100366A1 (en) * 2004-10-20 2006-05-11 O'brien Robert M Coating compositions for cans and methods of coating

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020176994A1 (en) * 2001-02-27 2002-11-28 Shalati Mohamad Deeb Reactive non-isocyanate coating compositions
US20050277569A1 (en) * 2004-06-14 2005-12-15 Goodall Brian L Catalytic composition and its preparation and use for preparing polymers from ethylenically unsaturated monomers
US20060100366A1 (en) * 2004-10-20 2006-05-11 O'brien Robert M Coating compositions for cans and methods of coating

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US9029470B2 (en) 2009-02-24 2015-05-12 Akzo Nobel Coatings International B.V. Latex emulsions and coating compositions formed from latex emulsions
US9394456B2 (en) 2009-02-24 2016-07-19 Akzo Nobel Coatings International B.V. Latex emulsions and coating compositions formed from latex emulsions
US9133292B2 (en) 2009-03-05 2015-09-15 Akzo Nobel Coatings International B.V. Hydroxyl functional oil polyol acrylic graft copolymers
US9458345B2 (en) 2010-12-28 2016-10-04 Akzo Nobel Coatings International B.V. Coating compositions comprising latex emulsions and hydroxyl functional oil polyol graft copolymers
US9181448B2 (en) 2010-12-29 2015-11-10 Akzo Nobel Coatings International B.V. Latex emulsions and coating compositions formed from latex emulsions
WO2012162299A1 (fr) * 2011-05-23 2012-11-29 Ppg Industries Ohio, Inc. Compositions de revêtement pour récipients
US9260625B2 (en) 2011-12-21 2016-02-16 Akzo Nobel Coatings International B.V. Water-based coating compositions
US9273226B2 (en) 2011-12-21 2016-03-01 Akzo Nobel Coatings International B.V. Solvent-based coating compositions
US10800941B2 (en) 2014-12-24 2020-10-13 Valspar Sourcing, Inc. Coating compositions for packaging articles such as food and beverage containers
US11725067B2 (en) 2014-12-24 2023-08-15 Swimc Llc Styrene-free coating compositions for packaging articles such as food and beverage containers
US11332636B2 (en) 2014-12-24 2022-05-17 Swimc Llc Coating compositions for packaging articles such as food and beverage containers
US10968288B2 (en) 2014-12-24 2021-04-06 Swimc Llc Styrene-free coating compositions for packaging articles such as food and beverage containers
WO2017180895A1 (fr) * 2016-04-15 2017-10-19 Valspar Sourcing, Inc. Copolymères sans styrène et compositions de revêtement contenant de tels copolymères
US11306168B2 (en) 2016-04-15 2022-04-19 Swimc Llc Styrene-free copolymers and coating compositions containing such copolymers
US10501639B2 (en) 2016-04-15 2019-12-10 Swimc Llc Styrene-free copolymers and coating compositions containing such copolymers
EP3443044A4 (fr) * 2016-04-15 2020-01-01 Swimc LLC Copolymères sans styrène et compositions de revêtement contenant de tels copolymères
US11795250B2 (en) 2016-04-15 2023-10-24 Swimc Styrene-free copolymers and coating compositions containing such copolymers
US10836915B2 (en) 2016-04-15 2020-11-17 Swimc Llc Styrene-free copolymers and coating compositions containing such copolymers
EP3950861A1 (fr) * 2016-04-15 2022-02-09 Swimc LLC Copolymères sans styrène et compositions de revêtement contenant de tels copolymères
WO2017198936A1 (fr) * 2016-05-20 2017-11-23 Constellium Neuf-Brisach Bande metalloplastique pour emballage alimentaire rigide et procédé de fabrication
US11623792B2 (en) 2016-05-20 2023-04-11 Constellium Neuf-Brisach Metalloplastic strip for rigid food packaging and manufacturing method
FR3051395A1 (fr) * 2016-05-20 2017-11-24 Constellium Neuf-Brisach Bande metalloplastique pour emballage alimentaire rigide et procede de fabrication
EP3484964B1 (fr) 2016-07-15 2022-04-13 Swimc Llc Composition de revêtement en latex ayant des propriétés de réduction de l'arôme réduites
CN109715739A (zh) * 2016-07-15 2019-05-03 Swimc有限公司 具有降低的风味剥落性质的胶乳涂料组合物
EP4086314A1 (fr) * 2016-07-15 2022-11-09 Swimc Llc Composition de revêtement en latex ayant des propriétés de réduction de l'arôme réduites
WO2018013766A1 (fr) * 2016-07-15 2018-01-18 Valspar Sourcing, Inc. Composition de revêtement en latex ayant des propriétés de réduction de l'arôme réduites
US11602768B2 (en) 2016-10-19 2023-03-14 Swimc, Llc Acrylic polymers and compositions containing such polymers
US11059989B2 (en) 2017-06-30 2021-07-13 Valspar Sourcing, Inc. Crosslinked coating compositions for packaging articles such as food and beverage containers
US11667809B2 (en) 2017-08-25 2023-06-06 Swimc Llc Adhesion promoters and compositions for containers and other articles
WO2019040823A1 (fr) * 2017-08-25 2019-02-28 The Sherwin-Williams Company Promoteurs d'adhésion et compositions pour récipients et autres articles
US11427654B2 (en) 2017-09-01 2022-08-30 Swimc Llc Multi-stage polymeric latexes, coating compositions containing such latexes, and articles coated therewith
US11466162B2 (en) 2017-09-01 2022-10-11 Swimc Llc Multi-stage polymeric latexes, coating compositions containing such latexes, and articles coated therewith

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