Classifications

• • 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
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/44—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes for electrophoretic applications
• • 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
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/44—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes for electrophoretic applications
  • C09D5/4484—Anodic paints
• • 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
  • C08F289/00—Macromolecular compounds obtained by polymerising monomers on to macromolecular compounds not provided for in groups C08F251/00 - C08F287/00
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
  • C08L51/08—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to macromolecular compounds obtained otherwise than 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
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers

Definitions

• the present invention relates to methods for electrocoating full panel easy open ends, wherein a surface of the end is substantially uncqated prior to electrodepositipn.
• the present invention is directed to methods for electrocoating a substantially uncoated surface of a full panel easy open end, comprising electrodepositing on the end an electrodepositable coating.
• Full panel easy open ends prepared according to this method are also within the scope of the invention. .
• the present invention is directed to methods for electrocoating full panel easy open ends, comprising electrodepositing an electrodepositable coating on the ends.
• a surface of the end is substantially uncoated according to the present methods.
• a full panel easy open end will be understood by one skilled in. the art as an end or lid in which substantially all (i.e. 90 percent or greater) of the lid is removed upon opening of the can; opening is effected by means of a pull tab, as opposed to a conventional can opener.
• a score substantially around the perimeter of the lid allows for easy opening or removing of the lid from the can, typically by . means of a pull tab.
• a full panel easy open end is therefore distinguished from other Sids or ends, which may be removed only by means of a can opener, or in which only a small portion of the lid is removed or otherwise opened, such as in the manner of a beverage can.
• a full panel easy open end is coated by means of electrodeposition.
• a substantially uncoated. i ⁇ - • , . • . - • surface of the end is coated according to the present methods. "Substantially : uncoated” and like terms mean 50 percent or greater of a surface is uncoated.
• the present invention is distinct from electr ⁇ coat "repair" known in the art, in which much less than 50 percent of the end's surface is uncoated prior to electrodeposition.
• Such lids are already substantially coated with one or more other layers.
• conventional lid repair methodologies discussed above, only a very small percent of the lid is electrocoated.
• the present, methods are therefore distinct from the art. For example, an end having a precoated exterior, such as some sort of print, with a clear overcoat, can be treated according to the present methods, in which any uncoated portion of the exterior, and/or the substantially uncoated interior of the lid will be electrocoated.
• an electrodepositable coating will not deposit on any portion of the end that is coated prior to electrocoating, unless such coating is electrically conductive.
• an end having substantially no coating on the interior and/or the exterior can be treated according to the methods of the present invention. These alternatives are not intended to be exhaustive.
• touch points may occur on the ends, as a result of the device used to hold the ends in place during electro- deposition. The effects of the touch points are minimized, however, by "reflow” that occurs when the contacts are removed and the uncured electrocoat paint flows into the touch points, such as during the high temperature bake.
• any suitable electrodepositable coating can be used according to the present invention. Either cathbdic or anodic elecfrodepositi ⁇ n can be used, with anodic typically being more suitable. Since the full panel easy open ends are typically used in conjunction with food . cans, however, it may be desired to use components that are approved by the United States Food and Drug Administration (“FDA”) for direct food contact and/or the European Inventory of Existing Commercial Substances (“EINECS").
• FDA United States Food and Drug Administration
• EINECS European Inventory of Existing Commercial Substances
• the term "food can” is used herein to refer to cans, containers, or any type of metal receptacle for holding any type of food or beverage.
• the coating can be any conventional ep ⁇ xy-amine coating used in the industry that can be electrodeposited onto a conductive substrate.
• polymers useful in forming the resin include hydroxyl or carboxylic acid-containing acrylic copolymers, hydroxyl or carboxylic acid- containing polyester polymers, isocyanate or hydroxyl containing polyurethane polymers, and amine or isocyanate containing polyureas. These polymers are further described in U.S. Patent No.
• film-forming resins are acrylic resins and epoxy-acrylic resins, such as those that are commercially available from PPG Industries, Inc., or otherwise reported in the art. Curing agents for these resins are also described in the '491 patent at column 6, lines 6 to 62; particularly suitable crosslinkers, especially for epoxy-acrylic resins and acrylic resins, include melamine, benzoguanamine, and phenolic crosslinkers.
• the electrodepositable coating is epoxy free.
• “Epoxy-free” and like terms means that all components of . the coating are substantially free from oxirane rings or residues of oxirane rings; bisphenol A; bisphenol A diglycidylether (“BADGE”) or adducts of BADGE.
• the coatings used according to the present invention can be epoxy free and/or free from polyvinylchloride and/or related halide-containing vinyl polymers.
• the coating is epoxy- free and comprises acrylic resin, such as an acrylic crosslinked with a phenolic.
• Acrylic polymers can be (meth)acrylic acid and/or hydroxy alkyl esters of (meth)acrylic acid, such as hydroxyethylmethacrylate or hydroxypropyl(meth)acrylate; alkyl esters of (meth)acrylic can also be used, such as methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, and the like, as can 2-ethylhexyl(meth)acrylate, acrylamide reacted with formaldehyde and butanol (“nBMA"), vinyl aromatic compounds such as styrene and vinyl toluene, nitriles such as (meth)acrylonitrile, and vinyl esters such as vinyl acetate. Any other acrylic monomers known to those skilled in the art could also be used.
• the term "(nBMA) vinyl aromatic compounds such
• the coating may comprise both an acrylic moiety and a polyester moiety.
• the two moieties can be combined, for example, by blending or by grafting. Suitable blends and grafts are described in U.S. Publication No. 2004/0044117A1 , which is hereby incorporated by reference. .
• the coatings of the present invention are water-borne or aqueous coatings. Aqueous coatings are generally preferred over solvent-based coatings for environmental reasons. The term "aqueous" as used herein . means that the.coatings are predominantly water.
• 2004/0044117A1 which is hereby referred to herein, are suitable for use in the present invention and can have improved water solubility by neutralizing the acid with a suitable amine, such as dimethylethylamine. When the acid is sufficiently neutralized, it can then be slowly added to water.
• a suitable amine such as dimethylethylamine
• Coatings used according to the present invention will typically comprise a curing agent.
• the curing agent is a phenolic or mixture of phenolics. Suitable phenolics are commercially available from Cytec in their PHENODUR line.
• the crosslinker comprises 30 weight percent or greater, such as 50 weight percent or greater, such as 60 weight percent. or greater of the total solid weight of the coating.
• the coatings used according to the present methods can also comprise a pigment. Any suitable pigment can be used including TiO 2 , ZnO, and MgO. Pigments can be added for color and also for hiding and stain resistance in coatings for food cans that may contain high sulfide foods, such as meats.
• the composition used according to the present methods may further comprise one or more additives standard in the art, such as coalescence solvents, plasticizers, dispersing agents, wetting agents, light stabilizers, surfactants and catalysts. Such additives, if used, will typically comprise 0.001 to 5 weight percent, based on the total solid weight of the coating.
• any suitable electrocoating method can be used according to the present invention, such any of those well known in the art.
• cure, of the electrodeposited coating can be. conducted using cure parameters known in the art and based upon a particular coating used. When using certain phenolics, for example, a cure of 3 minutes at 400 0 F may be suitable.
• the dry film thickness of. the cured coating can range, for example, from 7 to 12 mgs/in 2 .
• Suitable substrates include any of those known in the can art, such as tin plated steel, tin-free steel, and black-plated steel.
• the full panel easy open ends of the present invention can be used in conjunction with any suitable type of can, such as food cans.
• Suitable cans include two-piece cans and three-piece cans.
• a two-piece can will be understood by those skilled in the art as referring to a drawn and wall ironed can; a three-piece can will be understood by those skilled in the art as referring to one that is coated in flat sheet, fabricated and welded.
• the present invention is further directed to methods for preparing a full panel easy open end comprising stamping an end from a metal sheet and electrodepositing on the end an electrodepositable coating. At least one surface of the end is substantially uncoated prior to the electrodeposition step.
• the metal may be lubricated prior to stamping, such as by Using a commercially available lubricant. Suitable lubricants are available from PPG Industries, Inc. Typically, the lubricant is cleaned from the metal following stamping. Again, any conventional cleaner can be used to remove the lubricant, such as acidic or alkaline cleaners commercially available from PPG Industries, Inc.
• the lubricant does not constitute a "coating", and that a full panel easy open end having a lubricant and/or cleaner applied thereto and nothing else would still be regarded as being "uncoated”.
• some portion of one or both of the surfaces of the end can have some coating applied thereto prior to electrodeposition.
• a print . or other design may be applied to one or both sides of the end prior to electrbcoating.
• the print can be covered with a clear protective coat.
• At least one surface of the end, however, is substantially uncoated prior to electrodeposition.
• the electrodeposition process, coating, and the like are as described above.
• a second electrocoat may be desired, according to any embodiments of the present invention, to apply a second electrocoat following cure of the first electrocoat.
• a second electrocoat wouid be desired to minimize the possibility of any blister points or touch points that may have been created during cure of the first coat.
• a single coat of electrodepositable coating on the full panel easy open end will give suitable enamel rater test results.
• the methods of the present invention can consistently result in ends giving enamel rater readings of less than 25 milliamps, such as less than 10 milliamps or even less than 5 milliamps.
• a second electrocoat can be used according to the present invention, it is a feature of the present invention that no additional coat needs to be used over top of the electrocoat according to the present methods.
• the need to do a repair on an end is minimized, if not eliminated, because the part is stamped prior to coating.
• the present invention represents a significant savings in both time and materials as compared with conventional methods, in which one, two or even three coats are applied to a metal sheet, the end is stamped. ' and repair of the coating is required.
• the present invention is further directed to a full panel easy open end prepared according to any of the methods disclosed herein.
• This example illustrates the preparation of a polyester-graft-acrylic copolymer. .
• the reaction mixture was cooled to 18O 0 C, the packed column replaced with a Dean-Stark and a nitrogen sparge was started.
• Charge #3 was added and the reaction was heated to 195 0 C for 7 hours at which ; time the acid value was less than 3.0 mg KOH/gram.
• the resin was cooled, thinned with Charge #4, discharged and analyzed.
• the determined acid value was 2.1 mg KOH/gram, and hydroxy value was 20.9 mg KOH/gram.
• the determined non-volatile content of the resin was 69.9% as measured by weight loss of a sample heated to 110 0 C for 1 hour.
• Analysis of the polymer by GPC (using linear polystyrene standards) showed the polymer to have an M w value of 10,115, M n value of 2,798, and an M w /M n value of 3.6.
• polyester-graft-acrylic.copolymer "B” Synthesis of polyester-graft-acrylic.copolymer "B” is carried out as follows:
• the reaction product was then cooled, discharged and analyzed: The determined acid, value was 28.6 mg KOH/gram.
• the determined non-volatile content of the resin was 59.70% as measured by weight loss of a sample heated to 110 0 C for 1 hour.
• Analysis of the polymer by GPC (using linear polystyrene standards) showed the polymer to have an M w value of 147,598, M n value of 4,937, and an M w /M n value of 29.9,
• This example illustrates the preparation of a polyester-graft-acrylic copolymer.
• Charge #1 was added to a round-bottom, 4-necked flask equipped with a motor driven stainless steel stir blade, a water cooled condenser and a heating mantle with a thermometer connected through a temperature feed-back control device. The contents of the flask were heated to reflux temperature. The addition of Charges #2 and #3 were started simultaneously and continued over 3 hours. After the additions were complete, the reaction was held at 12O 0 C for 30 minutes. Charge #4 was then added to the mixture and after 60 additional minutes, Charge #5 was added. After Charge #5 was added, the mixture was held for 60 additional minutes, and Charge #6 was added.
• the reaction product was then cooled, discharged and analyzed.
• the determined acid value was 28.6 mg KOH/gram.
• the determined non-volatile content of the resin was 61.00% as measured by weight loss of a sample heated to 11O 0 C for 1 hour.
• Analysis of the polymer by GPC (using linear polystyrene standards) showed the polymer to have an M w value of 38,794, M n value of 4,878, and an M w /Mn value of 8.0.
• Example 3 This example illustrates the preparation of an acrylic polymer.
• Charge #1 was added to a round-bottom, 4-necked flask equipped with a motor driven stainless steel stir blade, a water cooled condenser and a heating mantle with a thermometer connected through a temperature feed-back control device. The contents of the flask were heated to reflux temperature. The addition of Charges #2 and #3 were started simultaneously and continued over 3 hours. After the additions were complete, 1/3 of Charge #4 was added to the mixture and after 60 additional minutes an additional 1/3 of Charge #4 was added and after 60 additional minutes the 1/3 of Charge #4 was added. After the final portion of Charge #4 was added, the mixture was held for 120 additional minutes, then cooled and discharged from the reactor.
• a coating composition was formulated from the polyester-graft-acrylic copolymer "B" of Example 1 (Part 2).
• the resulting coating was electrodeposited on tinplated 207.5 easy open ends.
• the electrodeposition took place at a voltage of 245 volts over a 3 second dwell at a bath temperature of 77 0 F.
• the ends were baked in a gas fired oven at an oven temperature of 41O 0 F for 3 minutes, to give a film weight of ⁇ 8 mg/in 2 .
• the resulting ends were tested for film integrity using a Wilkensr Anderson WACO Digital Enamel Rater (See Table 5). Average Enamel Rater values less than 3 milliamps, with no single value greater than 5, were targeted.
• a coating composition was formulated from the polyester-graft-acrylic copolymer "C" of Example 2.
• the ends were baked in a gas fired oven at an oven temperature of 41O 0 F for 3 minutes, to give a film weight of ⁇ 8 mg/in 2 .
• the resulting ends were tested for film integrity using a Wilkens- Anderson WACO Digital Enamel Rater (See Table 5). Average Enamel Rater values less than 3.milliamps, with no single value greater than 5, were targeted.
• a coating composition was formulated from the acrylic polymer "D" of
• the resulting coating was electrodeposited on tinplated 300 full panel easy open ends.
• the electrodeposition took place at a voltage of 230 volts over a 30 second dwell at a bath temperature of 85 0 F.
• the ends were baked in a gas fired oven at an oven temperature of 410 0 F for 3 minutes, to give a film weight of - ⁇ 8 mg/in 2 .
• the resulting ends were tested for film integrity using a Wilkens- Anderson WACO Digital Enamel Rater (See Table 5). Average Enamel Rater values less than 3 milliamps, with no single value greater than 5, were targeted.
• Example 4 3.8 0.9 2.3 1 .6 3.5 1,9 2.3
• Example 5. 0.5 0.4 .1-2 • 1.7 0,1 0,1 0.7
• Example 6 . 0.0 0.0 . .0.0 . 0.1 0.0
• excellent enamel rater readings were obtained with all three coatings.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Molecular Biology (AREA)
• Paints Or Removers (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Rigid Containers With Two Or More Constituent Elements (AREA)
• Panels For Use In Building Construction (AREA)
• Containers Opened By Tearing Frangible Portions (AREA)
• Sealing Material Composition (AREA)
• Lubricants (AREA)

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• 2005
  • 2005-10-07 US US11/246,466 patent/US20070080065A1/en not_active Abandoned
• 2006
  • 2006-10-03 BR BRPI0617996-7A patent/BRPI0617996A2/pt not_active IP Right Cessation
  • 2006-10-03 JP JP2008534631A patent/JP4790810B2/ja not_active Expired - Fee Related
  • 2006-10-03 EP EP06816152A patent/EP1931738A2/en not_active Withdrawn
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  • 2006-10-03 AU AU2006302532A patent/AU2006302532B2/en not_active Ceased
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  • 2006-10-03 WO PCT/US2006/038697 patent/WO2007044359A2/en not_active Ceased
  • 2006-10-03 KR KR1020087008216A patent/KR20080043395A/ko not_active Abandoned
  • 2006-10-04 TW TW095136897A patent/TWI336357B/zh not_active IP Right Cessation
  • 2006-10-05 UY UY29841A patent/UY29841A1/es not_active Application Discontinuation
  • 2006-10-05 AR ARP060104397A patent/AR057537A1/es not_active Application Discontinuation
  • 2006-10-10 PE PE2006001231A patent/PE20070734A1/es not_active Application Discontinuation
• 2008
  • 2008-03-19 ZA ZA200802615A patent/ZA200802615B/xx unknown
  • 2008-04-03 EC EC2008008344A patent/ECSP088344A/es unknown

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