Acid coating for improved cleaning

Abstract

Disclosed herein is an improved metal or glass container. The metal or glass container includes a body portion and an end closure. The end closure exhibits reduced oxides and hydroxides prior to application of a liner or lacquer, improving adhesion to the end closure. Provided are methods and systems that improve the cleaning of the end closure without increasing waste or require additional waste treatment operations.

Description

ACID COATING FOR IMPROVED CLEANINGREFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 558,181, filed on February 27, 2024, and entitled ACID COATING FOR IMPROVED CLEANING, the content of which is hereby incorporated by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates to metalworking generally and, more specifically, to laminated metal strips suitable for use as can end stock and to their production.BACKGROUND

[0003] Certain metal products, such as aluminum beverage cans, may require or otherwise benefit from a protective layer between the metal and its contents. For example, beverage cans often must provide sufficient protection between the metal of the beverage can and the beverage contained therein to avoid damage to the metal from harsh beverages, such as sodas and colas, as well as to avoid undesirable effects to the beverage, such as discoloration or change in taste. Furthermore, metal products may further benefit from a protective layer between the metal and the exterior environment. A protective layer on the exterior of beverage cans, for example, may protect the beverage can from abrasion or other damage during production processes. The protective layer on the exterior of beverage cans may also be necessary or beneficial in applying an exterior design on the beverage can.

[0004] There are often requirements placed on the protective layers on both the interior and exterior surfaces of metal products. For example, the protective layer must adequately adhere to the metal product. On the exterior surface, by way of further example, the protective layer must typically demonstrate a homogenous color, resistance to abrasion, appropriate opening behavior, and appropriate general behavior during end manufacturing. Conventional protective layers, such as lacquer, have been found to demonstrate inadequate abrasion resistance. Previously attempted alternatives to the conventional protective layers, meanwhile, have been found to exhibit undesirable hairing and feathering. Furthermore, conventional protective layers have exhibitedinadequate adhesion to the metal product, poor color, and require costly and time-intensive production processes. It is believed that conventional protective layers are ineffective due at least in part to the failure of present methods to fully clean the substrate surface prior to application of a liner pretreatment.SUMMARY

[0005] The term embodiment and like terms are intended to refer broadly to all of the subject matter of this disclosure and the claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the claims below. Embodiments of the present disclosure covered herein are defined by the claims below, not this summary. This summary is a high-level overview of various aspects of the disclosure and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this disclosure, any or all drawings and each claim.

[0006] The present technology is generally directed to processes and systems for preparing can end stock. Processes include cleaning a metal strip with an alkaline cleaning solution. Processes include cleaning the metal strip with an acid coating cleaning solution, where the acid coating cleaning solution is applied to the metal strip at a basis weight of 1 g / m2to 100 g / m2. Processes include applying an adhesion promoter to a first side of the acid coated metal strip.

[0007] In embodiments, the metal strip is an aluminum strip. In more embodiments, processes include where no drying step is conducted after cleaning the metal strip with the acid coating cleaning solution. Furthermore, in embodiments, the acid coating is dried prior to application of the adhesion promoter. Additionally or alternatively, in embodiments, the acid coating cleaning solution is applied at a rate of 0.1 grams per minute to 10 grams per minute. Embodiments include where the acid coating cleaning solution is applied at a rate of 0.5 grams per minute to 6 grams per minute. Moreover, in embodiments, the acid coating cleaning solution is applied to the metal strip at a basis weight from 10 g / m2to 75 g / m2. In further embodiments, the acid coating cleaning solution includes sulfuric acid (H2SO4), hydrofluoric acid (HF), phosphoric acid (H3PO4), nitricacid (HNCh), hydrochloric acid (HC1), hydrobromic acid (HBr), perchloric acid (HCIO4), hydroiodic acid (HI), boric acid (H3BO3), or a combination thereof, and / or where the acid coating cleaning solution comprises a pH of from 1 to 5. In yet more embodiments, the metal strip is rinsed after cleaning with the alkaline cleaning solution. Embodiments include where no rinsing step is conducted after cleaning with the acid coating cleaning solution. Further embodiments include that after the cleaning with the acid coating cleaning solution, less than 10% of a surface area of the metal strip contains an oxide or hydroxide thereon. In embodiments, processes include applying a lacquer or a polymer fdm to the adhesion promoter.

[0008] The present technology is also generally directed to can end stock products prepared according to any one or more of the processes discussed above. In embodiments, the first side of the metal strip corresponds to an exterior-facing side of the can end stock product. The present technology is also generally directed to beverage cans that include a body piece and an end cap, where the end cap is formed from can end stock prepared according to any one or more of the processes discussed above.

[0009] The present technology is also generally directed to processes and systems for preparing metal strips. Systems include an alkaline clean and rinse station. Systems include an acid coating station positioned downstream of the alkaline clean and rinse station for accepting a metal strip from the alkaline clean and rinse station, where the acid coating station includes an applicator configured to apply the acid coating at a rate of 0.1 grams per minute to 10 grams per minute. Systems include an adhesion promoter system positioned downstream of the acidic coating station.

[0010] In embodiments, systems include a pre-heating oven positioned downstream from the adhesion promoter system, and a protective layer application system positioned downstream of the pre-heating oven for accepting the metal strip at a pre-heating temperature and applying a protective layer to an adhesion promoter layer on a first side of the metal strip, where the first side of the metal strip corresponds to an exterior-facing side of a can end formed from the metal strip. In further embodiments, the metal strip is an aluminum strip, wherein the alkaline rinse station is positioned between the alkaline clean station and the acid coating station. Moreover, in embodiments, there is no rinse station disposed between the acid coating station and the adhesion promoter system. Additionally or alternatively, in embodiments, the acid coating station includes a spray application, a roll-on system, a wipe-on system, or a combination thereof.

[0011] Other objects and advantages will be apparent from the following detailed description of non-limiting examples.BRIEF DESCRIPTION OF THE FIGURES

[0012] The disclosure is described in detail below with reference to the appended drawings, wherein like numerals designate similar parts.

[0013] Figure 1 is a schematic diagram of a system and method for preparing can end stock according to certain aspects of the present disclosure.

[0014] Figure 2 is a schematic depicting a can end stock configuration as described herein.DETAILED DESCRIPTION

[0015] Described herein are processes and systems for producing can end stock from a metal strip, such as an aluminum strip. In the processes described herein, a secondary cleaning operation may be conducted without producing further waste or expensive processing changes, but that provides improved color and adhesion of a protective layer. The resultant can end stock can be used, for example, in beverage cans.

[0016] Can end stock produced according the methods described herein advantageously exhibit improved properties. In particular, the can end stock exhibits improved color, low surface oxidation, and improved adhesion to a protective layer, and also exhibits reduced blistering along seams or rivets. Furthermore, the can end stock described herein can be formed without expensive bleed down systems, as the methods and systems discussed herein advantageously avoid the need for additional waste treatment. Alternatively or additionally, the processes and systems discussed herein do not require further rinsing generally associated with cleaning operations, reducing waste and cost, as well as reducing the overall water usage of the process. Thus, the processes and systems discussed herein may provide an improved can end stock without requiring costly and wasteful cleaning operation.

[0017] In embodiments, a container includes a body portion and the end closure. The end closure may include a lacquer coating and / or a laminated polymer film attached to the product side of the end closure. When the container is sealed (e.g., seamed), the lacquer and / or laminatedpolymer film attached to the product side of the end closure contacts the product side of the body (or, in some examples, a coating provided thereon), providing an end closure liner.De finitions and Descriptions

[0018] As used herein, the terms “invention,” “the invention,” “this invention,” and “the present invention” are intended to refer broadly to all of the subject matter of this patent application and the claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below.

[0019] In this description, reference is made to alloys identified by aluminum industry designations, such as “series” or “5xxx.” For an understanding of the number designation system most commonly used in naming and identifying aluminum and its alloys, see “International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys” or “Registration Record of Aluminum Association Alloy Designations and Chemical Compositions Limits for Aluminum Alloys in the Form of Castings and Ingot,” both published by The Aluminum Association.

[0020] Aluminum alloys are described herein in terms of their elemental composition in weight percentage (wt. %) based on the total weight of the alloy. In certain examples of each alloy, the remainder is aluminum, with a maximum wt. % of 0.15 % for the sum of the impurities.

[0021] As used herein, “feathering” refers to the elongation and delamination of a protective layer (e.g., lacquer and / or polymer film) on the metal strip. The extent of feathering is measured by the amount of the protective layer that extends over the cut aluminum edge as a result of elongation and delamination. Can end stock is especially susceptible to feathering when cutting a disc from the can end stock to produce a can end. In addition, feathering is a risk at breaks in the metal, such as the orifice created when opening a beverage can.

[0022] As used herein, “hairing” refers to the formation of visible hair-like deformations in a protective layer on the metal strip. Can end stock is especially susceptible to hairing when cutting through the protective layer (e.g., polymer film), such as to create a score line. In some cases, hairing is a result of poor adhesion of the protective layer to the metal strip.

[0023] Reference is made in this application to alloy temper or condition. For an understanding of the alloy temper descriptions most commonly used, see “American National Standards (ANSI) H35 on Alloy and Temper Designation Systems.” An F condition or temper refers to an aluminumalloy as fabricated. An O condition or temper refers to an aluminum alloy after annealing. An Hxx condition or temper, also referred to herein as an H temper, refers to an aluminum alloy after cold rolling with or without thermal treatment (e.g., annealing). Suitable H tempers include HX1, HX2, HX3 HX4, HX5, HX6, HX7, HX8, or HX9 tempers. For example, the aluminum alloy can be cold rolled to result in a possible Hl 9 temper. In a further example, the aluminum alloy can be cold rolled and annealed to result in a possible H23 temper.

[0024] As used herein, terms such as “cast metal article,” “cast article,” and the like are interchangeable and refer to a product produced by direct chill casting (including direct chill cocasting) or semi-continuous casting, continuous casting (including, for example, by use of a twin belt caster, a twin roll caster, a block caster, or any other continuous caster), electromagnetic casting, hot top casting, or any other casting method.

[0025] As used herein, a plate generally has a thickness of greater than about 15 mm. For example, a plate may refer to an aluminum product having a thickness of greater than about 15 mm, greater than about 20 mm, greater than about 25 mm, greater than about 30 mm, greater than about 35 mm, greater than about 40 mm, greater than about 45 mm, greater than about 50 mm, greater than about 100 mm, or up to about 200 mm.

[0026] As used herein, a shate (also referred to as a sheet plate) generally has a thickness of from about 4 mm to about 15 mm. For example, a shate may have a thickness of about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, about 11 mm, about 12 mm, about 13 mm, about 14 mm, or about 15 mm.

[0027] As used herein, a sheet generally refers to an aluminum product having a thickness of less than about 4 mm. For example, a sheet may have a thickness of less than about 4 mm, less than about 3 mm, less than about 2 mm, less than about 1 mm, less than about 0.5 mm, or less than about 0.3 mm (e.g., about 0.2 mm).

[0028] As used herein, the meaning of “a,” “an,” or “the” includes singular and plural references unless the context clearly dictates otherwise.

[0029] As used herein, the meaning of “room temperature” can include a temperature of from about 15 °C to about 30 °C, for example about 15 °C, about 16 °C, about 17 °C, about 18 °C, about 19 °C, about 20 °C, about 21 °C, about 22 °C, about 23 °C, about 24 °C, about 25 °C, about 26 °C, about 27 °C, about 28 °C, about 29 °C, or about 30 °C.

[0030] All ranges disclosed herein are to be understood to encompass any and all endpoints, and any and all subranges subsumed therein. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, e.g. 1 to 6.1, and ending with a maximum value of 10 or less, e.g., 5.5 to 10.

[0031] As used herein, the term “polymer” is inclusive of homopolymers and copolymers. Homopolymer refers to a polymer derived from a single polymerizable monomer. Copolymer refers to a polymer derived from two or more polymerizable monomers.Metal Strip

[0032] The present disclosure provides processes and systems for producing can end stock from a metal strip. More specifically, the methods described herein include cleaning a metal strip prior to application of a pretreatment and / or protective layer to the metal strip. The composition of the metal strip on which the polymer film is laminated is not limited. The methods described herein are particularly well suited for, but not limited to, aluminum strips. The polymer film may be applied, for example, to any suitable aluminum alloy, such as a continuous coil of an aluminum alloy. Suitable aluminum alloys include, for example, Ixxx series aluminum alloys, 2xxx series aluminum alloys, 3xxx series aluminum alloys, 4xxx series aluminum alloys, 5xxx series aluminum alloys, 6xxx series aluminum alloys, 7xxx series aluminum alloys, and 8xxx series aluminum alloys.

[0033] By way of non-limiting example, exemplary Ixxx series aluminum alloys for use as the metal strip can include AA 1100, AA1100A, AA1200, AA1200A, AA1300, AA1110, AA1120, AA1230, AA1230A, AA1235, AA1435, AA1145, AA1345, AA1445, AA1150, AA135O, AA1350A, AA1450, AA1370, AA1275, AA1185, AA1285, AA1385, AA1188, AA1190, AA1290, AA1193, AA1198, or AA1199. In some cases, the aluminum alloy is at least 99.9 % pure aluminum (e.g., at least 99.91 %, at least 99.92 %, at least 99.93 %, at least 99.94 %, at least 99.95 %, at least 99.96 %, at least 99.97 %, at least 99.98 %, or at least 99.99 % pure aluminum).

[0034] Non-limiting exemplary 2xxx series aluminum alloys for use as the metal strip can include AA2001, AA2002, AA2004, AA2005, AA2006, AA2007, AA2007A, AA2007B, AA2008, AA2009, AA2010, AA2011, AA2011A, AA2111, AA2111A, AA2111B, AA2012, AA2013, AA2014, AA2014A, AA2214, AA2015, AA2016, AA2017, AA2017A, AA2117,AA2018, AA2218, AA2618, AA2618A, AA2219, AA2319, AA2419, AA2519, AA2021, AA2022, AA2023, AA2024, AA2024A, AA2124, AA2224, AA2224A, AA2324, AA2424, AA2524, AA2624, AA2724, AA2824, AA2025, AA2026, AA2027, AA2028, AA2028A, AA2028B, AA2028C, AA2029, AA2030, AA2031, AA2032, AA2034, AA2036, AA2037, AA2038, AA2039, AA2139, AA2040, AA2041, AA2044, AA2045, AA2050, AA2055, AA2056, AA2060, AA2065, AA2070, AA2076, AA2090, AA2091, AA2094, AA2095, AA2195, AA2295, AA2196, AA2296, AA2097, AA2197, AA2297, AA2397, AA2098, AA2198, AA2099, or AA2199.

[0035] Non-limiting exemplary 3xxx series aluminum alloys for use as the metal strip can include AA3002, AA3102, AA3OO3, AA3103, AA3103A, AA3103B, AA3203, AA3403, AA3004, AA3004A, AA3104, AA3204, AA3304, AA3005, AA3OO5A, AA3105, AA3105A, AA31O5B, AA3007, AA3107, AA3207, AA3207A, AA3307, AA3009, AA3010, AA3110, AA3011, AA3012, AA3012A, AA3O13, AA3014, AA3015, AA3016, AA3017, AA3019, AA3020, AA3021, AA3025, AA3026, AA3030, AA3130, or AA3065.

[0036] Non-limiting exemplary 4xxx series aluminum alloys for use as the metal strip can include AA4004, AA4104, AA4006, AA4007, AA4008, AA4009, AA4010, AA4013, AA4014, AA4015, AA4015A, AA4115, AA4016, AA4017, AA4018, AA4019, AA4020, AA4021, AA4026, AA4032, AA4043, AA4043A, AA4143, AA4343, AA4643, AA4943, AA4044, AA4045, AA4145, AA4145A, AA4046, AA4047, AA4047A, or AA4147.

[0037] Non-limiting exemplary 5xxx series aluminum alloys for use as the metal strip can include AA5182, AA5183, AA5OO5, AA5005A, AA5205, AA5305, AA5505, AA5605, AA5006, AA5106, AA5010, AA5110, AA5110A, AA5210, AA5310, AA5016, AA5017, AA5018, AA5018A, AA5019, AA5019A, AA5119, AA5119A, AA5021, AA5022, AA5023, AA5024, AA5026, AA5027, AA5028, AA5040, AA5140, AA5041, AA5042, AA5043, AA5049, AA5149, AA5249, AA5349, AA5449, AA5449A, AA5O5O, AA5050A, AA5050C, AA5150, AA5051, AA5051A, AA5151, AA5251, AA5251A, AA5351, AA5451, AA5052, AA5252, AA5352, AA5154, AA5154A, AA5154B, AA5154C, AA5254, AA5354, AA5454, AA5554, AA5654, AA5654A, AA5754, AA5854, AA5954, AA5056, AA5356, AA5356A, AA5456, AA5456A, AA5456B, AA5556, AA5556A, AA5556B, AA5556C, AA5257, AA5457, AA5557, AA5657, AA5058, AA5059, AA5070, AA5180, AA5180A, AA5082, AA5182, AA5083, AA5183,AA5183A, AA5283, AA5283A, AA5283B, AA5383, AA5483, AA5086, AA5186, AA5087, AA5187, or AA5088.

[0038] Non-limiting exemplary 6xxx series aluminum alloys for use as the metal strip can include AA6101, AA6101A, AA6101B, AA6201, AA6201A, AA6401, AA6501, AA6002, AA6003, AA6103, AA6005, AA6005A, AA6005B, AA6005C, AA6105, AA6205, AA6305, AA6006, AA6106, AA6206, AA6306, AA6008, AA6009, AA6010, AA6110, AA6110A, AA6011, AA6111, AA6012, AA6012A, AA6013, AA6113, AA6014, AA6015, AA6016,AA6016A, AA6116, AA6018, AA6019, AA6020, AA6021, AA6022, AA6023, AA6024,AA6025, AA6026, AA6027, AA6028, AA6031, AA6032, AA6033, AA6040, AA6041, AA6042, AA6043, AA6151, AA6351, AA6351A, AA6451, AA6951, AA6053, AA6055, AA6056,AA6156, AA6060, AA6160, AA6260, AA6360, AA6460, AA6460B, AA6560, AA6660,AA6061, AA6061A, AA6261, AA6361, AA6162, AA6262, AA6262A, AA6063, AA6063A, AA6463, AA6463A, AA6763, A6963, AA6064, AA6064A, AA6065, AA6066, AA6068, AA6069, AA6070, AA6081, AA6181, AA6181A, AA6082, AA6082A, AA6182, AA6091, or AA6092.

[0039] Non-limiting exemplary 7xxx series aluminum alloys for use as the metal strip can include AA7011, AA7019, AA7020, AA7021, AA7039, AA7072, AA7075, AA7085, AA7108, AA7108A, AA7015, AA7017, AA7018, AA7019A, AA7024, AA7025, AA7028, AA7030, AA7031, AA7033, AA7035, AA7035A, AA7046, AA7046A, AA7003, AA7004, AA7005, AA7009, AA7010, AA7011, AA7012, AA7014, AA7016, AA7116, AA7122, AA7023, AA7026, AA7029, AA7129, AA7229, AA7032, AA7033, AA7034, AA7036, AA7136, AA7037, AA7040, AA7140, AA7041, AA7049, AA7049A, AA7149, AA7204, AA7249, AA7349, AA7449, AA7050, AA7050A, AA7150, AA7250, AA7055, AA7155, AA7255, AA7056, AA7060, AA7064, AA7065, AA7068, AA7168, AA7175, AA7475, AA7076, AA7178, AA7278, AA7278A, AA7081, AA7181, AA7185, AA7090, AA7093, AA7095, or AA7099.

[0040] Non-limiting exemplary 8xxx series aluminum alloys for use as the metal strip can include AA8005, AA8006, AA8007, AA8008, AA8010, AA8011, AA8011A, AA8111, AA8211, AA8112, AA8014, AA8015, AA8016, AA8017, AA8018, AA8019, AA8021, AA8021A, AA8021B, AA8022, AA8023, AA8024, AA8025, AA8026, AA8030, AA8130, AA8040, AA8050, AA8150, AA8076, AA8076A, AA8176, AA8077, AA8177, AA8079, AA8090, AA8091, and AA8093.

[0041] In some embodiments, the metal strip comprises AA3104, AA5006, AA5182, or a combination thereof.

[0042] While aluminum alloy products are described throughout the disclosure, the methods and products apply to any metal strip. In some embodiments, the metal strip is aluminum, an aluminum alloy, magnesium, a magnesium-based material, titanium, a titanium-based material, copper, a copper-based material, steel, a steel-based material, bronze, a bronze-based material, brass, a brass-based material, a composite, a sheet used in composites, or any other suitable metal or combination of materials. The product may include monolithic materials, as well as non- monolithic materials such as roll-bonded materials, clad materials, composite materials, or various other materials. In some examples, the metal article is a metal coil, a metal strip, a metal plate, a metal sheet, a metal billet, a metal ingot, or the like.

[0043] The metal strip can be prepared from an alloy of any suitable temper. In certain examples, the alloys can be used in F, O, T3, T4, T6, or T8x tempers. The alloys can be produced by direct chill casting (including direct chill co-casting) or semi-continuous casting, continuous casting (including, for example, by use of a twin belt caster, a twin roll caster, a block caster, or any other continuous caster), electromagnetic casting, hot top casting, or any other casting method.Lacquer

[0044] In some embodiments, the protective layer according the present disclosure may include one or more layers of lacquer. In some cases, for example, a layer of lacquer may be applied to a surface of the metal strip, e.g., the internal-facing surface. In these embodiments, the lacquer forms a protective layer between the metal strip and the contents of the can end stock (e.g., the contents of a beverage can formed from can end stock). Surprisingly, lacquers according the present technology may also exhibit improved adhesion due at least in part to the improvements in surface quality and consistency after the second cleaning operation discussed herein.

[0045] The composition of the lacquer suitable for use in the processes described herein is not particularly limited. In some cases, the lacquer includes a water-based and / or solvent-based composition, which preferably may be sprayed, poured, or otherwise applied to a surface of the metal strip. In some embodiments, the lacquer applied to a surface of the metal strip includes an epoxy-based solution, a polyester solution, or a combination thereof.

[0046] In some examples, the lacquer can include a natural polymer or a synthetic polymer. In some non-limiting examples, the lacquer can be prepared from a homopolymer or a copolymer. Suitable homopolymers include polyesters (e.g., polyethylene terephthalate (PET)), epoxies, polyurethanes, polyvinyls, polyacrylics, polyamides, polyolefins, and silicones. In some cases, the polyesters can be hot melt polyesters. In some cases, the lacquer can include copolymers. Suitable copolymers as described herein include block copolymers, random copolymers, graft copolymers, copolymer blends, statistical copolymers, periodic copolymers, alternating copolymers, star copolymers, starblock copolymers, and / or any combinations thereof. The copolymers can be configured as head-to-head copolymers and / or as head-to-tail copolymers. The copolymers can have any suitable structure, or be any suitable isomer thereof (e.g., cis isomers or trans isomers).

[0047] In embodiments, the lacquer can be a polyester film. In some cases, the polyester film can be a hot melt polyester film. Optionally, the lacquer can be a polyethylene terephthalate (PET) film. In some examples, the PET film includes a polymer derived from ethylene glycol, terephthalic acid, or a terephthalate-containing compound, and optionally one or more additional comonomers. The one or more additional comonomers can be used to tailor the properties of the film, such as the melting temperature. Exemplary comonomers for use as the additional comonomers can include isophthalic acid, butylene diol, 2-methyl- 1,3 -propanediol, phthalate, 1,8- naphthalenedicarboxylate, and 1,8-anthracenedicarboxylate, to name a few. Optionally, the polymer film includes a polyethylene naphthalate film. Commercial examples of compositions suitable for use as a lacquer for the present disclosure include EzDex from Sherwin-Williams (Cleveland, OH).

[0048] Suitable polymers for use as the lacquer can have a weight average molecular weight (Mw) of the copolymers between about 10,000 grams per mole (g / mol) and about 500,000 g / mol. For example, the Mw can be from about 20,000 g / mol to about 400,000 g / mol; from about 30,000 g / mol to about 300,000 g / mol; or from about 40,000 g / mol to about 100,000 g / mol, or any value in between. For example, the Mw can be 10,000 g / mol, 20,000 g / mol, 30,000 g / mol, 40,000 g / mol, 50,000 g / mol, 60,000 g / mol, 70,000 g / mol, 80,000 g / mol, 90,000 g / mol, 100,000 g / mol, 110,000 g / mol, 120,000 g / mol, 130,000 g / mol, 140,000 g / mol, 150,000 g / mol, 160,000 g / mol, 170,000 g / mol, 180,000 g / mol, 190,000 g / mol, 200,000 g / mol, 210,000 g / mol, 220,000 g / mol, 230,000 g / mol, 240,000 g / mol, 250,000 g / mol, 260,000 g / mol, 270,000 g / mol, 280,000 g / mol, 290,000 g / mol, 300,000 g / mol, 310,000 g / mol, 320,000 g / mol, 330,000 g / mol, 340,000 g / mol, 350,000g / mol, 360,000 g / mol, 370,000 g / mol, 380,000 g / mol, 390,000 g / mol, 400,000 g / mol, 410,000 g / mol, 420,000 g / mol, 430,000 g / mol, 440,000 g / mol, 450,000 g / mol, 460,000 g / mol, 470,000 g / mol, 480,000 g / mol, 490,000 g / mol, or 500,000 g / mol.

[0049] In some non-limiting examples, the lacquer is resistant to (e.g., does not degrade in the presence of) nitrogen gas, carbon dioxide, acidic materials, alkaline materials, solvents, corrosive materials, or materials having a pH of from about 1 to about 14 (e.g., from about 2 to about 13, from about 3 to about 12, from about 4 to about 11, from about 5 to about 10, from about 6 to about 9, or from about 7 to about 8). For example, the lacquer is resistant to materials having a pH of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or anywhere in between. In some cases, the lacquer is resistant to alcoholic liquids (e.g., alcoholic beverages, solvents, or the like). For example, the lacquer is resistant to alcoholic liquids containing up to about 50 percent by volume (vol. %) alcohol (e.g., from about to about 4 vol. % to about 40 vol. %, from about 6 vol. % to about 50 vol. %, from about 8 vol. % to about 40 vol. %, from about 10 vol. % to about 35 vol. %, from about 12 vol. % to about 25 vol. %, or from about 15 vol. % to about 20 vol. %). For example, the lacquer is resistant to alcoholic liquids containing an amount of alcohol of about 1 vol. %, 2 vol. %, 3 vol. %, 4 vol. %, 5 vol. %, 6 vol. %, 7 vol. %, 8 vol. %, 9 vol. %, 10 vol. %, 11 vol. %, 12 vol. %, 13 vol. %, 14 vol. %, 15 vol. %, 16 vol. %, 17 vol. %, 18 vol. %, 19 vol. %, 20 vol. %,21 vol. %, 22 vol. %, 23 vol. %, 24 vol. %, 25 vol. %, 26 vol. %, 27 vol. %, 28 vol. %, 29 vol. %,30 vol. %, 31 vol. %, 32 vol. %, 33 vol. %, 34 vol. %, 35 vol. %, 36 vol. %, 37 vol. %, 38 vol. %,39 vol. %, 40 vol. %, 41 vol. %, 42 vol. %, 43 vol. %, 44 vol. %, 45 vol. %, 46 vol. %, 47 vol. %,48 vol. %, 49 vol. %, or 50 vol. %.

[0050] In embodiments, the lacquer provides a product shelflife of up to about four years (e.g., up to about 6 months, up to about 12 months, up to about 18 months, up to about 24 months, up to about 36 months, or up to about 48 months). For example, the lacquer as described herein provides a product shelf life of up to about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 13 months, 14 months, 15 months, 16 months, 17 months, 18 months, 19 months, 20 months, 21 months, 22 months, 23 months, 24 months, 25 months, 26 months, 27 months, 28 months, 29 months, 30 months, 31 months, 32 months, 33 months, 34 months, 35 months, 36 months, 37 months, 38 months, 39 months, 40 months, 41 months, 42 months, 43 months, 44 months, 45 months, 46 months, 47 months, or 48months. In some cases, the lacquer is suitable for products that are consumed as soon as accessible or shortly thereafter (e.g., products having a shelflife of less than 1 month, such as 0 months).

[0051] In some embodiments, the layer of lacquer has an average thickness of from 2 pm to 20 pm, e.g., from 2 pm to 18 pm, from 2 pm to 16 pm, from 2 pm to 14 pm, from 2 pm to 12 pm, from 2 pm to 10 pm, from 3 pm to 20 pm, from 3 pm to 18 pm, from 3 pm to 16 pm, from 3 pm to 14 pm, from 3 pm to 12 pm, from 3 pm to 10 pm, from 4 pm to 20 pm, from 4 pm to 18 pm, from 4 pm to 16 pm, from 4 pm to 14 pm, from 4 pm to 12 pm, from 4 pm to 10 pm, from 5 pm to 20 pm, from 5 pm to 18 pm, from 5 pm to 16 pm, from 5 pm to 14 pm, from 5 pm to 12 pm, from 5 pm to 10 pm, from 6 pm to 20 pm, from 6 pm to 18 pm, from 6 pm to 16 pm, from 6 pm to 14 pm, from 6 pm to 12 pm, or from 6 pm to 10 pm.

[0052] In terms of lower limits, the layer of lacquer may have an average thickness greater than 2 pm, e.g., greater than 3 pm, greater than 4 pm, greater than 5 pm, or greater than 6 pm. In terms of upper limits, the layer of lacquer may have an average thickness less than 20 pm, e.g., less than 18 pm, less than 16 pm, less than 14 pm, less than 12 pm, or less than 10 pm.

[0053] Examples of suitable average thicknesses of the layer of lacquer include 2 pm, 3 pm, 4 pm, 5 pm, 6 pm, 7 pm, 8 pm, 9 pm, 10 pm, 11 pm, 12 pm, 13 pm, 14 pm, 15 pm, 16 pm, 17 pm, 18 pm, 19 pm, and 20 pm, and any thickness therebetween.

[0054] In some cases, the thickness of the layer of lacquer may be expressed in terms of basis weight. In some embodiments, the layer of lacquer has a basis weight of from 1 g / m2to 15 g / m2, e.g., from 1 g / m2to 14 g / m2, from 1 g / m2to 12 g / m2, from 1 g / m2to 10 g / m2, from 1 g / m2to 8 g / m2, from 1 g / m2to 6 g / m2, from 1.5 g / m2to 15 g / m2, from 1.5 g / m2to 14 g / m2, from 1.5 g / m2to 12 g / m2, from 1.5 g / m2to 10 g / m2, from 1.5 g / m2to 8 g / m2, from 1.5 g / m2to 6 g / m2, from 2 g / m2to 15 g / m2, from 2 g / m2to 14 g / m2, from 2 g / m2to 12 g / m2, from 2 g / m2to 10 g / m2, from 2 g / m2to 8 g / m2, from 2 g / m2to 6 g / m2, from 2.5 g / m2to 15 g / m2, from 2.5 g / m2to 14 g / m2, from 2.5 g / m2to 12 g / m2, from 2.5 g / m2to 10 g / m2, from 2.5 g / m2to 8 g / m2, from 2.5 g / m2to 6 g / m2, from 3 g / m2to 15 g / m2, from 3 g / m2to 14 g / m2, from 3 g / m2to 12 g / m2, from 3 g / m2to 10 g / m2, from 3 g / m2to 8 g / m2, or from 3 g / m2to 6 g / m2.

[0055] In terms of lower limits, the layer of lacquer may have a basis weight greater than 1 g / m2, e.g., greater than 1.5 g / m2, greater than 2 g / m2, greater than 2.5 g / m2, or greater than 3 g / m2. In terms of upper limits, the layer of lacquer may have a basis weight less than 15 g / m2, e.g., less than 14 g / m2, less than 12 g / m2, less than 10 g / m2, less than 8 g / m2, or less than 6 g / m2.

[0056] Examples of suitable basis weight of the layer of lacquer include 1 g / m2, 1 .5 g / m2, 2 g / m2, 2.5 g / m2, 3 g / m2, 3.5 g / m2, 4 g / m2, 4.5 g / m2, 5 g / m2, 5.5 g / m2, 6 g / m2, 6.5 g / m2, 7 g / m2, 7.5 g / m2, 8 g / m2, 9 g / m2, 10 g / m2, 11 g / m2, 12 g / m2, 13 g / m2, 14 g / m2, 15 g / m2, and any thickness therebetween.

[0057] In some embodiments, the can end stock produced according the present disclosure comprises an adhesion coating between the metal strip and the layer of lacquer. In particular, an adhesion coating may be applied to the metal strip, and the lacquer may be applied thereon. The adhesion coating beneficially fixes the lacquer to the metal strip. In some embodiments, the adhesion coating is a pretreatment applied to the metal strip, e.g., a pretreatment suited to the metal strip. The adhesion coating between the metal strip and layer of lacquer may be the same or different from the adhesion coating between the polymer film and the metal strip. Commercial examples of suitable pretreatments that can be employed as the adhesion coating between the metal strip and the lacquer include titanium zirconium (Ti-Zr) based pretreatments, such as Bonderite from Henkel Adhesive Technologies (Dusseldorf, Germany) and / or Perm atr eat 1903 from BASF- Chemetall. Nonetheless, as discussed above, the processes and systems discussed herein may provide improved adhesion of the adhesion coating and thus, also, the lacquer layer.Polymer Film

[0058] In embodiments, the protective layer discussed herein may include laminating a polymer film to the metal strip. However, as discussed above, in embodiments, the polymer film may instead be painted or coated onto the can end stock, and my therefore be referred to as a “lacquer”. Thus, any one or more of the polymer films discussed herein may be either laminated or coated, onto the metal sheet. Nonetheless, in embodiments, the processes of the present disclosure may include laminating or coating the polymer film on a side (e.g., the first side) of the metal strip that corresponds to an exterior-facing side of a can end formed from the metal strip after the cleaning methods and processes discussed in greater detail below. Thus, the polymer film forms a portion of the public side of the can end stock.

[0059] As further detailed in the examples below, the use of a polymer film on an exteriorfacing side of a can end may beneficially improve the quality of the can end product. In particular, the polymer film imparts greater resistance to abrasion relative to conventional can end products. However, it should be clear that, by utilizing the enhanced cleaning processes and systemsdiscussed herein, improved adhesion and abrasion resistance may be achieved with other protective layers, and thus, the protective layer may include a lacquer, a laminate, or a combination thereof.

[0060] The polymer fdm is not particularly limited and may include any polymer suitable for the desired use of the can end stock (e.g., as a beverage can). Suitable polymers for the polymer film include, for example, polyethylene, polypropylene, and polyethylene terephthalate (PET). In some cases, the polymer film laminated to the metal strip is a biaxially oriented polymer, such as a biaxially-oriented polyethylene terephthalate (BoPET) film.

[0061] In some embodiments, the polymer film further includes a colorant, such as a dye or a colorant particle or pigment. Said another way, the polymer film may be a colored polymer film (e.g., a colored PET film). In embodiments, the use of colored polymer films may beneficially improve the quality of the can end product. Relative to colorless polymer films, the colored films may exhibit a low tendency for hairing. Without being bound by theory, it is believed that the presence of colorant particles in the film affect the composition of the films so as to facilitate smooth breaking of the film (e.g., at the creation of the orifice when opening a beverage can).

[0062] The colorant used in the colored polymer film is not particularly limited. Suitable colorants include, for example, titanium dioxide (e.g., to produce a white polymer film) and carbon black (e.g., to produce a black polymer film).

[0063] In some embodiments, the polymer film has an average thickness of from 5 pm to 150 pm, e.g., from 5 pm to 125 pm, from 5 pm to 100 pm, from 5 pm to 75 pm, from 5 pm to 50 pm, from 5 pm to 25 pm, from 6 pm to 150 pm, from 6 pm to 125 pm, from 6 pm to 100 pm, from 6 pm to 75 pm, from 6 pm to 50 pm, from 6 pm to 25 pm, from 8 pm to 150 pm, from 8 pm to 125 pm, from 8 pm to 100 pm, from 8 pm to 75 pm, from 8 pm to 50 pm, from 8 pm to 25 pm, from 10 pm to 150 pm, from 10 pm to 125 pm, from 10 pm to 100 pm, from 10 pm to 75 pm, from 10 pm to 50 pm, from 10 pm to 25 pm, from 12 pm to 150 pm, from 12 pm to 125 pm, from 12 pm to 100 pm, from 12 pm to 75 pm, from 12 pm to 50 pm, or from 12 pm to 25 pm.

[0064] In terms of lower limits, the polymer film may have an average thickness greater than 5 pm, e.g., greater than 6 pm, greater than 8 pm, greater than 10 pm, or greater than 12 pm. In terms of upper limits, the polymer film may have an average thickness less than 150 pm, e.g., less than 125 pm, less than 100 pm, less than 75 pm, less than 50 pm, or less than 25 pm.

[0065] Examples of suitable average thicknesses of the polymer film include 10 pm, 1 1 pm,12 pm, 13 pm, 14 pm, 15 pm, 16 pm, 17 pm, 18 pm, 19 pm, 20 pm, 21 pm, 22 pm, 23 pm, 24 pm,25 pm, 26 pm, 27 pm, 28 pm, 29 pm, 30 pm, 31 pm, 32 pm, 33 pm, 34 pm, 35 pm, 36 pm, 37 pm,38 pm, 39 pm, 40 pm, 41 pm, 42 pm, 43 pm, 44 pm, 45 pm, 46 pm, 47 pm, 48 pm, 49 pm, 50 pm,51 pm, 52 pm, 53 pm, 54 pm, 55 pm, 56 pm, 57 pm, 58 pm, 59 pm, 60 pm, and any thickness therebetween.

[0066] In some embodiments, the process of the present disclosure includes laminating multiple layers of polymer film on the metal strip. In these embodiments, each layer of polymer film may independently be a polymer film as described above. In some cases, multiple layers of polymer film are laminated on the metal strip, and each of the layers are identical (e.g., in terms of composition, colorant, and / or thickness). In some cases, multiple layers of polymer film are laminated on the metal strip, and each of the layers are not identical (e.g., in terms of composition, colorant, and / or thickness).Adhesion Coatins

[0067] In some embodiments, the can end stock produced according the present disclosure includes an adhesion coating. In particular, an adhesion coating may be applied to the metal strip, and the polymer film and / or coating may be coated or laminated thereon. The adhesion coating beneficially fixes the protective layer to the metal strip.

[0068] In embodiments, the adhesion coating according to the present technology may exhibit improved adhesion to the metal strip and to the protective layer. Thus, the adhesion coating may provide improved feathering performance, improved adhesion, and other benefits. In particular, adhesion of the protective layer to the metal strip can be controlled (e.g., improved) by utilizing the cleaning methods and systems discussed below by providing excellent adhesion and consistent application of the adhesion coating, in addition to controlling process parameters (such as the annealing temperature, as described below).

[0069] In some embodiments, the adhesion coating is a pretreatment applied to the metal strip, e.g., a pretreatment suited to the metal strip. Commercial examples of suitable pretreatments that can be employed as the adhesion coating include Addibond 712 - CP 30 from Solvay (Brussels, Belgium).Wax Coating

[0070] In some embodiments, the can end stock produced according the present disclosure includes a wax coating. In some cases, for example, a wax coating may be applied to the externalfacing surface of the protective layer. The wax coating beneficially improves the appearance of the can end stock. In particular, a wax coating according to the present disclosure exhibits a homogenous appearance with minimal or no streaking in appearance. In addition, the wax coating acts as lubricant to reduce friction forces on the surface. Lubrication may be necessary to ensure proper function of the machinery used in the production of the can end stock.

[0071] The wax coating may comprise a solution of wax, e.g., carnauba wax, petroleum, wax, and the like. Commercial example of suitable wax products that can be employed as the wax coating include LUBA-print 965-A from Miinzing (Abstatt, Germany). In some embodiments, the wax coating is a dilution of carnauba wax or a petroleum wax in water. For example, the wax coating may comprise a dilution of carnauba wax (e.g., LUBA-print 965-A) at a volume ratio of from 1 :2 to 1:50 (e.g., 1:5, 1 :6, 1 :8, 1: 10, 1 : 12, 1 :14, 1 :16, 1 : 18, or 1 :20) with water. Diluting the wax coating ensures that the wax coating can be pumped into a nip during commercial application and mitigate foaming, which has been found to dry and to lead to solid carnauba particles on the surface of the can end stock.

[0072] In some embodiments, the wax coating has an average thickness of from 5 mg / m2to 150 mg / m2, e.g., from 5 mg / m2to 120 mg / m2, from 5 mg / m2to 115 mg / m2, from 5 mg / m2to 110 mg / m2, from 5 mg / m2to 105 mg / m2, from 5 mg / m2to 100 mg / m2, from 6 mg / m2to 150 mg / m2, from 6 mg / m2to 120 mg / m2, from 6 mg / m2to 115 mg / m2, from 6 mg / m2to 110 mg / m2, from 6 mg / m2to 105 mg / m2, from 6 mg / m2to 100 mg / m2, from 7 mg / m2to 150 mg / m2, from 7 mg / m2to 120 mg / m2, from 7 mg / m2to 115 mg / m2, from 7 mg / m2to 110 mg / m2, from 7 mg / m2to 105 mg / m2, from 7 mg / m2to 100 mg / m2, from 8 mg / m2to 150 mg / m2, from 8 mg / m2to 120 mg / m2, from 8 mg / m2to 115 mg / m2, from 8 mg / m2to 110 mg / m2, from 8 mg / m2to 105 mg / m2, from 8 mg / m2to 100 mg / m2, from 9 mg / m2to 150 mg / m2, from 9 mg / m2to 120 mg / m2, from 9 mg / m2to 115 mg / m2, from 9 mg / m2to 110 mg / m2, from 9 mg / m2to 105 mg / m2, from 9 mg / m2to 100 mg / m2, from 10 mg / m2to 150 mg / m2, from 10 mg / m2to 120 mg / m2, from 10 mg / m2to 115 mg / m2, from 10 mg / m2to 110 mg / m2, from 10 mg / m2to 105 mg / m2, or from 10 mg / m2to 100 mg / m2.

[0073] In terms of lower limits, the wax coating may have an average thickness greater than 5 mg / m2, e g., greater than 6 mg / m2, greater than 7 mg / m2, greater than 8 mg / m2, greater than 9mg / m2, or greater than 10 mg / m2. In terms of upper limits, the wax coating may have an average thickness less than 125 mg / m2, e.g., less than 120 mg / m2, less than 115 mg / m2, less than 110 mg / m2, less than 105 mg / m2, or less than 100 mg / m2.Containers

[0074] In embodiments, the containers incorporating the can end stock discussed herein may include a metal or glass container, including a body (e.g., a metal container body or a glass bottle body) having a sealable opening, a product facing body side (e.g., an inside), and a consumer facing body side (e.g., an outside). The metal or glass container further includes an end closure having a product facing closure side and a consumer facing closure side. The sealable opening is configured to receive the end closure, and likewise, the end closure is configured to engage the sealable opening.

[0075] The metal container can be prepared from any suitable metal article. In some examples, the metal container includes aluminum, an aluminum alloy, magnesium, a magnesium-based material, titanium, a titanium-based material, copper, a copper-based material, steel, a steel-based material, bronze, a bronze-based material, brass, a brass-based material, a composite, a sheet used in composites, or any other suitable metal or combination of materials. The metal article may include monolithic materials, as well as non-monolithic materials such as roll-bonded materials, clad materials, composite materials (such as, but not limited to, carbon fiber-containing materials), or various other materials. In some examples, the metal article used to prepare the metal container can be a metal coil, a metal strip, a metal plate, a metal sheet, a metal billet, a metal ingot, or the like. In some cases, the methods described herein can be applied to a non-metal article.

[0076] In some cases, the metal article for use in preparing the metal container is an aluminum alloy, such as a Ixxx series aluminum alloy, a 3xxx series aluminum alloy, or a 5xxx series aluminum alloy. By way of non-limiting example, exemplary Ixxx series aluminum alloys can include AA1100, AA1100A, AA1200, AA1200A, AA1300, AA1110, AA1120, AA1230, AA1230A, AA1235, AA1435, AA1145, AA1345, AA1445, AA1150, AA1350, AA135OA, AA1450, AA1370, AA1275, AA1185, AA1285, AA1385, AA1188, AA1190, AA1290, AA1193, AA1198, and AA1199.

[0077] By way of non-limiting example, exemplary 3xxx series aluminum alloys can include AA3002, AA3102, AA3003, AA3103, AA3103A, AA31O3B, AA3203, AA3403, AA3004,AA3004A, AA3104, AA3204, AA3304, AA3005, AA3OO5A, AA3105, AA31O5A, AA3105B, AA3007, AA3107, AA3207, AA3207A, AA3307, AA3009, AA3010, AA3110, AA3011, AA3012, AA3012A, AA3O13, AA3014, AA3015, AA3016, AA3017, AA3019, AA3020, AA3021, AA3025, AA3026, AA3030, AA3130, and AA3065.

[0078] Non-limiting exemplary 5xxx series aluminum alloys can include AA5OO5, AA5005A, AA5205, AA53O5, AA5505, AA5605, AA5006, AA5106, AA5010, AA5110, AA5110A, AA5210, AA5310, AA5016, AA5017, AA5018, AA5018A, AA5019, AA5019A, AA5119, AA5119A, AA5021, AA5022, AA5023, AA5024, AA5026, AA5027, AA5028, AA5040, AA5140, AA5041, AA5042, AA5043, AA5049, AA5149, AA5249, AA5349, AA5449, AA5449A, AA5050, AA5050A, AA5050C, AA5150, AA5O51, AA5051A, AA5151, AA5251, AA5251A, AA5351, AA5451, AA5052, AA5252, AA5352, AA5154, AA5154A, AA5154B, AA5154C, AA5254, AA5354, AA5454, AA5554, AA5654, AA5654A, AA5754, AA5854, AA5954, AA5056, AA5356, AA5356A, AA5456, AA5456A, AA5456B, AA5556, AA5556A, AA5556B, AA5556C, AA5257, AA5457, AA5557, AA5657, AA5O58, AA5059, AA5070, AA5180, AA5180A, AA5082, AA5182, AA5O83, AA5183, AA5183A, AA5283, AA5283A, AA5283B, AA5383, AA5483, AA5086, AA5186, AA5087, AA5187, and AA5088.Container Closures

[0079] In some non-limiting examples, the end closure described herein is an aluminum can end stock (CES) product. CES as used herein refers to an aluminum alloy formed to a shape to serve as a closure for an aluminum can. In some cases, the closure may include a scored orifice that can be broken by a consumer to form an opening in the can end to retrieve any product stored within the can. In some non-limiting examples, the end closure can be an easy open closure (e.g., a ring pull closure), a peel off closure (e.g., a thin foil closure), a beverage closure or seam (e.g., a double seam), a penny lever closure (e.g., a drum closure, or a paint can closure), a sanitary closure (e.g., a closure opened by cutting with, for example, a can opener), an aerosol valve cap closure, a ring pull closure, any suitable container end closure, or any combination thereof. In some cases, the closure can be a resealable closure. For example, the resealable closure can be a threaded closure (e.g., a twist-off cap), a bottle rolled-on pilfer proof closure, a clamp closure, a hinged closure, a snap-on closure, or any combination thereof.Container Bodies

[0080] In some non-limiting examples, the metal or glass container can have any suitable body shape, including a cylinder, a cube, a cuboid, a sphere, a cone, a tetrahedron, a pyramid, any other suitable three-dimensional (3-D) shape, or any combination thereof. Accordingly, the CES product can be formed into any shape suitable to form a closure for the container body. For example, the closure for the container body can be a disc (e.g., to seal a cylinder), a square (e.g., to seal a cube), a rectangle (e.g., to seal a cuboid), a hemisphere (e.g., to seal a sphere), a cone top (e.g., to seal a cone), a tetrahedron top (e.g., to seal a tetrahedron), a pyramid top (e.g., to seal a pyramid), any suitable closure that is complementary to a body (e.g., a closure that completes the shape of the body when joined together), or any combination thereof.

[0081] The container can be a beverage can (e.g., a soda can, a water can, an alcoholic beverage can, any pressurized beverage can, or any non-pressurized beverage can), a glass bottle (e.g., a water bottle, a soda bottle, an alcoholic beverage bottle, a chemical storage bottle, or the like), a food storage can (e.g., a canned vegetable can, a canned meat can, a sardine can, a pet food can, or an emergency provisions can), an aerosol can (e.g., a cooking spray can, a hairspray can, a lubricant can, or a whipped product can), a chemical storage can (e.g., a weak acid storage can, a weak base storage can, a solvent storage can, or any chemical suitable for use with a polymer film liner, such as a chemical that does not degrade the polymer film), any suitable metal container, or any combination thereof.Process and System for Preparins an Article, such as a Can End Stock

[0082] In embodiments, the present disclosure provides processes for preparing an article, such as a can end stock. The processes described herein advantageously produce coated articles having improved adhesion to films and / or lacquers, as well as excellent appearance and low occurrence of blistering. In some embodiments, the processes described herein produce articles that also exhibits high performance in other testing parameters, such as in an acetic acid test which can assess the corrosion resistance of the protective layer against acidic conditions that can result in delamination and / or peeling. According to the processes of the present disclosure, the present technology provides for a second cleaning operation, which will be referred to as an acid coating, after an alkaline cleaning operation. Surprisingly, the present technology has found that by carefully controlling coating thickness and application parameters, an acid coating may be appliedto react with any remaining surface oxidation after an alkaline clean, without producing excess runoff. Thus, processes and systems according to the present technology may provide for an enhanced clean without producing further waste which would require additional remediation.Cleaning

[0083] In some aspects, the process can include cleaning the article(s) before coating, operations of which may be illustrated in method 200. In some cases, the article is cleaned with an alkaline treatment at first cleaning operation 202. For example, the cleaning process can include an alkaline treatment comprising sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca(OH)2), or any combination thereof. In embodiments, the end closure stock is cleaned with an alkaline organic compound (i.e., an organic base) treatment. For example, the cleaning process can include an organic base treatment comprising barium ter / -butoxide (CsHisBaCh), choline hydroxide (C5H15NO2), di ethylamine (C4H11N), dimethylamine (C2H7N), ethylamine (C2H7N), methylamine (CHsN), piperidine (C5H11N), and / or any combination thereof. This cleaning treatment can reduce and / or remove any aluminum oxide or hydroxide layers on the surface of the article (e.g., an aluminum alloy strip). In embodiments, alkaline cleaning operation 202 may include a rinse after application of the alkaline treatment but prior to second cleaning operation 204.

[0084] Nonetheless, as discussed above, existing cleaning operations fail to fully remove oxide or hydroxide layers on either an internal surface, an external surface, or a combination thereof, of the article. Thus, the present technology provides, at second cleaning operation 204, where an acid coating is applied to the end closure stock. The present technology has surprisingly found that by carefully controlling coating thickness of the acid coating, excellent cleaning may be achieved without producing measurable runoff. Furthermore, due at least in part to the coating thickness and tailored amounts applied, no rinse operation may be necessary after the acid coating. Thus, advantageously, the present technology does not require an acid neutralization step in treating the wastewater, as little to no waste is produced. Due at least in part to the lack of additional waste produced, the systems and methods according to the present disclosure also do not require the use of a further loop or bleed down, thus reducing the footprint of operations according to the present technology and also allowing for improved efficiency of the process.

[0085] Namely, at second cleaning operation 204 after alkaline clean 202, a low volume of an acid coating 104 may be sprayed, or otherwise applied to a metal sheet 102. In embodiments, the application at operation 204 may include a spray bar or other suitable low volume spray system, or may instead be rolled or coated onto the can end stock, as well as other methods as known in the art. While the acid coating 104 is shown as forming a layer for illustration purposes, it should be clear that, in embodiments, the acid coating may be virtually undetectable in the final can end stock 100. Namely, the acid coating 104 may react with any oxides and / or hydroxides present on the can end stock 100, but may be present in such low amounts, selected to react with the oxides and hydroxides present, without providing excess acid to the can end stock.

[0086] In order to provide the tailored coating without producing excess acid or runoff, the coating may have a basis weight from 1 g / m2to 100 g / m2, or from 2 g / m2to 95 g / m2, or from 3 g / m2to 90 g / m2, or from 4 g / m2to 85 g / m2, or from 5 g / m2to 80 g / m2, or from 7.5 g / m2to 77.5 g / m2, or from 10 g / m2to 75 g / m2, or from 11 g / m2to 70 g / m2, or from 12 g / m2to 65 g / m2, or from 13 g / m2to 60 g / m2, or from 15 g / m2to 55 g / m2, or from 16 g / m2to 50 g / m2, or from 17 g / m2to 45 g / m2, or from 18 g / m2to 40 g / m2, or from 19 g / m2to 35 g / m2, or from 20 g / m2to 30 g / m2, or from 22.5 g / m2to 27.5 g / m2, or any ranges or values therebetween. In terms of lower limits, the acid coating may have a basis weight greater than 1 g / m2, e.g., greater than 2 g / m2, greater than 3 g / m2, greater than 4 g / m2, greater than 5 g / m2, greater than 6 g / m2, greater than 7 g / m2, greater than 8 g / m2, greater than 9 g / m2, greater than 10 g / m2, greater than 11 g / m2, greater than 12 g / m2, greater than 13 g / m2, greater than 14 g / m2, greater than 15 g / m2, greater than 16 g / m2, greater than 17 g / m2, greater than 18 g / m2, greater than 19 g / m2, greater than 20 g / m2, greater than 21 g / m2, greater than 22 g / m2, greater than 23 g / m2, greater than 24 g / m2, greater than 25 g / m2. In terms of upper limits, the layer of lacquer may have a basis weight less than 75 g / m2, e.g., less than 70 g / m2, less than 65 g / m2, less than 60 g / m2, less than 55 g / m2, or less than 50 g / m2, less than 45 g / m2, less than 40 g / m2, less than 35 g / m2, less than 30 g / m2, or less than 25 g / m2.

[0087] Thus, in embodiments, operation 204 may include spraying or otherwise applying the acid coating at a rate of from 0.1 grams per minute to 10 grams per minute, from 0.2 grams per minute to 9 grams per minute, from 0.3 grams per minute to 8 grams per minute, from 0.4 grams per minute to 7 grams per minute, from 0.5 grams per minute to 6 grams per minute, from 0.6 grams per minute to 5 grams per minute, from 0.7 grams per minute to 4 grams per minute, from 0.8 grams per minute to 3 grams per minute, from 0.9 grams per minute to 2 grams per minute,from 0.9 grams per minute to 1 .5 grams per minute, or from 0.9 grams per minute to 1 .1 grams per minute, or any ranges or values therebetween.

[0088] In embodiments, the acid coating may be a coating of sulfuric acid (H2SO4), hydrofluoric acid (HF), phosphoric acid (H3PO4), nitric acid (HNO3), hydrochloric acid (HC1), hydrobromic acid (HBr), perchloric acid (HCIO4), hydroiodic acid (HI), boric acid (H3BO3), and / or any combination thereof. In embodiments, the acid coating may be phosphoric acid, sulfuric acid, or a combination thereof. In embodiments, the acid coating is phosphoric acid. Regardless of the acid selected for the acid coating, the acid coating may have a pH of from 1 to 5, from 1 to 4, from 2 to 3, or any ranges or values therebetween.

[0089] In embodiments, the acid coating is applied at a temperature of from about 15 °C to about 85 °C, from about 20 °C to about 80 °C, from about 25 °C to about 75 °C, from about 30 °C to about 70 °C, from about 35 °C to about 65 °C, from about 40 °C to about 60 °C, or from about 45 °C to about 55°C.

[0090] Moreover, while, in embodiments no drying may be necessary, as the application rate and thickness has been carefully tailored to provide sufficient acid for reaction with any remaining oxide or hydroxide without producing waste, in embodiments it may be desired to dry or wipe the can end stock. In such embodiments, the wiping, such as by a roller, may provide an even coating as well as remove any drips. Additionally or alternatively, the drying may include other drying as known in the art, such as heat, air, or the like. Nonetheless, if drying is utilized, the acid coating should be allowed to remain on the can end stock for at least about 0.1 seconds to 5 seconds, from 0.2 seconds to 4 seconds, from 0.3 seconds to 3 seconds, from 0.4 seconds to 2 seconds, from 0.5 seconds to 1.5 seconds, from 0.6 seconds to 1.4 seconds, from 0.7 seconds to 1.3 seconds, from 0.8 seconds to 1.2 seconds, from 0.9 seconds to 1.1 seconds, or any ranges or values therebetween. In such a manner, the acid coating may fully react with any oxides or hydroxides present prior to the optional wiping or drying.

[0091] Regardless of whether any drying or wiping is necessary, the can end stock 100 may exhibit low surface oxide or hydroxide concentration. For instance in embodiments, the can end stock 100 may have a surface area where oxides or hydroxides cover from 0% to 10% of the surface area, from 0% to 9%, from 0% to 8%, from 0% to 7%, from 0% to 6%, from 0% to 5%, from 0.1% to 4%, from 0.2% to 3%, from 0.3% to 2.5%, from 0.4% to 2%, from 0.5% to 1.5%, from 0.6% to 1%, from 0.75% to 0.9%, or any ranges or values therebetween. Moreover, the canend stock 100 may exhibit the improved surface(s) (e.g., internal or external) without requiring an additional waste collection or treatment. Namely, as discussed above, when utilizing the amounts of acid coating discussed herein, little to no waste liquid may be formed during the acid coating cleaning operation 204, thus not requiring a collection or treatment step.Optional Pretreating

[0092] After the acid coating operation, optionally, the processes and systems can include pretreating the end closure stock with a conversion layer. In some cases, this conversion layer can include compounds of trivalent chromium (Cr(III)) and phosphates. In some cases, this conversion layer can include compounds of titanium and zirconium (Ti / Zr). This optional conversion layer can provide enhanced adhesion, low blushing after pasteurization, and resistance to corrosion when exposed to acids, such as acetic acid or citric acid. In some cases, the end closure stock can include one or more optional conversion layers located on the product side (e.g., an interior-facing side) and / or the consumer side (e.g., an exterior-facing side).

[0093] Optionally, the process can further include applying an adhesion promoter to the end closure stock. The adhesion promoter can provide enhanced adhesion in optional downstream coating steps. Adhesion promoters suitable for use in this process include silane-based chemistries, titanium / zirconium (Ti / Zr) based chemistries, and polymer-based chemistries. The adhesion promoter can be applied by dip coating, bar coating, roll coating, spin coating, spray coating, screen coating, drop coating, or using any other suitable coating technique. If the end closure stock is pre-treated with a conversion layer, the end closure stock pre-treated with the conversion layer can be further coated with the adhesion promoter as described above.

[0094] For instance, in embodiments, a metal strip 102, after cleaning operation 204, passes into an adhesion promoter coating operation 206, where an adhesion promoter 120 is applied to the metal strip. The metal strip 102, is passed through a coating system 114 that applies an adhesion promoter 120 to one side of the metal strip 102. In some cases, an adhesion promoter 120 can be applied to both sides of the metal strip 102. The adhesion promoter coating operation 114 can be any suitable system for coating metal strip 102.Protective layer application

[0095] In some examples, the process further includes a step of applying a protective layer to the article optionally coated with the adhesion promoter and optionally pre-treated with the conversion layer, at operation 208. In some cases, the article is not pre-treated with the adhesion promoter and / or the conversion layer. The application can include coating or otherwise applying one or more lacquers or fdms discussed above. In embodiments, the application 208 may include painting, rolling, or otherwise coating the article, and / or heating a polymer film to a temperature such that the polymer film is soft and tacky, applying the heated polymer film to at least a product facing side of the article. Regardless of the method of application of the protective layer, methods may also include heating the combined article and protective layer, optionally to an annealing temperature such that the protective layer can be at least partially viscous and wet the product facing side of the end closure stock. However, in embodiments, the protective layer(s) discussed herein may not require heating after coating.

[0096] For instance, in embodiments, referring again to FIG. 1 a pre-heated metal strip 108 that is optionally coated with an adhesion promoter 120, passes into a coating and / or lamination system 116 after cleaning operation 204 and / or application of the adhesion promoter 120 at operation 206. The metal strip 102, as an optionally pre-heated metal strip 106, is passed through a coating and / or lamination system 116 that applies a protective layer 122 to one side of the metal strip 102. In some cases, the protective layer can be applied to both sides of the metal strip 102. The coating and / or lamination system 116 can be any suitable system for coating and / or laminating a protective layer 122 to the metal strip 102. In some cases, the system 116 is a hot melt lamination system, a roll coating system, a spray coating system, a paint coating system, or the like. A metal strip having one or more protective layers 110 exits the lamination system 116, combining the metal strip 102 with protective layer 122.

[0097] After heating, the article and / or protection layer can be maintained at the temperature of at least 200 °C to about 280 °C for about 1 second to about 30 seconds (e.g., from about 5 seconds to about 25 seconds, from about 10 seconds to about 20 seconds, from about 5 seconds to about 30 seconds, or from about 10 seconds to about 30 seconds). For example, the end closure stock and / or polymer film can be maintained at the temperature of at least 200 °C to about 280 °C for about 1 second, about 2 seconds, about 3 seconds, about 4 seconds, about 5 seconds, about 6 seconds, about 7 seconds, about 8 seconds, about 9 seconds, about 10 seconds, about 11 seconds, about 12 seconds, about 13 seconds, about 14 seconds, about 15 seconds, about 16 seconds, about17 seconds, about 18 seconds, about 19 seconds, about 20 seconds, about 21 seconds, about 22 seconds, about 23 seconds, about 24 seconds, about 25 seconds, about 26 seconds, about 27 seconds, about 28 seconds, about 29 seconds, or about 30 seconds.

[0098] FIG. 2 illustrates a close-up side view of an article 110 of FIG. 1. The article 110 may include metal strip 102 sandwiched between a protective layer 122 and / or 124. Furthermore, as discussed above, acid coating 104 is shown as one or more layers, which may be shown for illustrative purpose. Namely, in embodiments, alkaline cleaning and / or acid coating 104 may overlie little to no surface area of the metal strip 102 after application and reaction.Forming and Sealing

[0099] In some embodiments, as discussed above, the article may be an end closure stock, which can be formed into any suitable shape closure. For example, the end closure stock can be formed into an easy open closure (e.g., a ring pull closure), a peel off closure (e.g., a thin foil closure), a beverage closure, a penny lever closure (e.g., a drum closure, or a paint can closure), a sanitary closure (e.g., a closure opened by cutting with, for example, a can opener), an aerosol valve cap closure, a resealable closure, a bottle rolled-on pilfer proof closure, any suitable container end closure, or any combination thereof, providing a closure with a protective layer thereon.

[0100] In some examples, the closure with a protective layer thereon is attached to a previously prepared container body (e.g., a previously formed and coated container body). Attaching the end closure encloses the product within the container. As described herein, the container body is configured to receive the end closure, wherein a product side of the container body contacts the protective layer on the product side of the end closure, thus providing the end closure liner.

[0101] Optionally, the sealed container may be annealed to bond the laminated polymer film and / or lacquer on the product side of the container body to the end closure. For example, the sealed container can be heated to an annealing temperature (e.g., 130 °C in the present example) such that the laminated polymer film and / or lacquer on the product side of the container body can at least partially flow and bond to a protective coating on the product facing side of the container body. Bonding the laminated polymer film and / or lacquer on the product side of the end closure to, forexample, a laminated polymer film and / or lacquer on the product side of the container body provides the end closure liner described herein.

[0102] The foregoing description of the embodiments, including illustrated embodiments, has been presented only for the purpose of illustration and description and is not intended to be exhaustive or limiting to the precise forms disclosed. Numerous modifications, adaptations, and uses thereof will be apparent to those skilled in the art. The following examples will serve to further illustrate the present invention without, at the same time, however, constituting any limitation thereof. On the contrary, it is to be clearly understood that resort may be had to various embodiments, modifications and equivalents thereof which, after reading the description herein, may suggest themselves to those skilled in the art without departing from the spirit of the invention.ILLUSTRATIVE ASPECTS

[0103] As used below, any reference to a series of aspects (e.g., “Aspects 1-4”) or nonenumerated group of aspects (e.g., “any previous or subsequent aspect”) is to be understood as a reference to each of those aspects disjunctively (e.g., “Aspects 1 -4” is to be understood as “Aspects 1, 2, 3, or 4”).

[0104] Aspect 1 : A process for preparing can end stock, comprising: cleaning a metal strip with an alkaline cleaning solution; cleaning a metal strip with an acid coating cleaning solution, wherein the acid coating cleaning solution is applied to the metal strip at a basis weight of 1 g / m2to 100 g / m2; and applying an adhesion promoter to a first side of the acid coated metal strip.

[0105] Aspect 2: The method of aspect 1, wherein the metal strip is an aluminum strip.

[0106] Aspect 3 : The method of aspect 1 or 2, wherein no drying step is conducted after cleaning the metal strip with the acid coating cleaning solution.

[0107] Aspect 4: The method of any one of aspects 1 to 3, wherein the acid coating is dried prior to application of the adhesion promoter.

[0108] Aspect 5: The method of any one of aspects 1 to 4, wherein the acid coating cleaning solution is applied at a rate of 0.1 grams per minute to 10 grams per minute.

[0109] Aspect 6: The method of any one of aspects 1 to 5, wherein the acid coating cleaning solution is applied at a rate of 0.5 grams per minute to 6 grams per minute.

[0110] Aspect 7: The method of any one of aspects 1 to 6, wherein the acid coating is applied to the metal strip at a basis weight from 10 g / m2to 75 g / m2.

[0111] Aspect 8: The method of any one of aspects 1 to 7, wherein the acid coating comprises sulfuric acid (H2SO4), hydrofluoric acid (HF), phosphoric acid (H3PO4), nitric acid (HNO3), hydrochloric acid (HC1), hydrobromic acid (HBr), perchloric acid (HCIO4), hydroiodic acid (HI), boric acid (H3BO3), or a combination thereof, and / or wherein the acid coating comprises a pH of from 1 to 5.

[0112] Aspect 9: The method of any one of aspects 1 to 8, wherein the metal strip is rinsed after cleaning with the alkaline cleaning solution.

[0113] Aspect 10: The method of any one of aspects 1 to 9, wherein no rinsing step is conducted after cleaning with the acid coating.

[0114] Aspect 11 : The method of any one of aspects 1 to 10, wherein after the cleaning with the acid coating, less than 10% of a surface area of the metal strip contains an oxide or hydroxide thereon.

[0115] Aspect 12: The method of any one of aspects 1 to 11, further comprising applying a lacquer or a polymer film to the adhesion promoter.

[0116] Aspect 13: A can end stock product prepared according to any one of aspects 1 to 12.

[0117] Aspect 14: The can end stock of aspect 13, wherein the first side of the metal strip corresponds to an exterior-facing side of the can end stock product.

[0118] Aspect 15: A beverage can comprising a body piece and an end cap, wherein the end cap is formed from can end stock prepared according to any one of aspects 1 to 12.

[0119] Aspect 16: A system, comprising: an alkaline clean and rinse station; an acid coating station positioned downstream of the alkaline clean and rinse station for accepting a metal strip from the alkaline clean and rinse station, wherein the acid coating station includes an applicator configured to apply the acid coating at a rate of 0.1 grams per minute to 10 grams per minute; and an adhesion promoter system positioned downstream of the acidic coating station.

[0120] Aspect 17: The system of aspect 16, further comprising a pre-heating oven positioned downstream from the adhesion promoter system, and a protective layer application system positioned downstream of the pre-heating oven for accepting the metal strip at a pre-heating temperature and applying a protective layer to an adhesion promoter layer on a first side of the metal strip, wherein the first side of the metal strip corresponds to an exterior-facing side of a can end formed from the metal strip.

[0121] Aspect 18: The system of aspects 16 or 17, wherein the metal strip is an aluminum strip, wherein the alkaline rinse station is positioned between the alkaline clean station and the acid coating station.

[0122] Aspect 19: The system of any one of aspects 16 to 18, wherein there is no rinse station disposed between the acid coating station and the adhesion promoter system.

[0123] Aspect 20: The system of any one of aspects 16 to 19, wherein the acid coating station comprises a spray application, a roll-on system, a wipe-on system, or a combination thereof.

[0124] All patents, publications, and abstracts cited above are incorporated herein by reference in their entireties. Various embodiments of the invention have been described in fulfillment of the various objectives of the invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptions thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention as defined in the following claims.

Claims

WHAT IS CLAIMED IS:

1. A process for preparing can end stock, comprising: cleaning a metal strip with an alkaline cleaning solution; cleaning the metal strip with an acid coating cleaning solution, wherein the acid coating cleaning solution is applied to the metal strip at a basis weight of 1 g / m2to 100 g / m2; and applying an adhesion promoter to a first side of the acid coated metal strip.

2. The process of claim 1, wherein the metal strip is an aluminum strip.

3. The process of claim 1, wherein no drying step is conducted after cleaning the metal strip with the acid coating cleaning solution.

4. The process of claim 1, wherein the acid coating cleaning solution is dried prior to application of the adhesion promoter.

5. The process of claim 1, wherein the acid coating cleaning solution is applied at a rate of 0.1 grams per minute to 10 grams per minute.

6. The process of claim 5, wherein the acid coating cleaning solution is applied at a rate of 0.5 grams per minute to 6 grams per minute.

7. The process of claim 1, wherein the acid coating cleaning solution is applied to the metal strip at a basis weight from 10 g / m2to 75 g / m2.

8. The process of claim 7, wherein the acid coating cleaning solution comprises sulfuric acid (H2SO4), hydrofluoric acid (HF), phosphoric acid (H3PO4), nitric acid (HNO3), hydrochloric acid (HC1), hydrobromic acid (HBr), perchloric acid (HCIO4), hydroiodic acid (HI), boric acid (H3BO3), or a combination thereof, and / or wherein the acid coating cleaning solution comprises a pH of from 1 to 5.

9. The process of claim 1, wherein the metal strip is rinsed after cleaning with the alkaline cleaning solution.

10. The process of claim 1, wherein no rinsing step is conducted after cleaning with the acid coating cleaning solution.11 . The process of claim 1, wherein after the cleaning with the acid coating cleaning solution, less than 10% of a surface area of the metal strip contains an oxide or hydroxide thereon.

12. The process of claim 1, further comprising applying a lacquer or a polymer film to the adhesion promoter.

13. A can end stock product prepared according to the process of claim 1.

14. The can end stock product of claim 13, wherein the first side of the metal strip corresponds to an exterior-facing side of the can end stock product.

15. A beverage can comprising a body piece and an end cap, wherein the end cap is formed from can end stock prepared according to the process of claim 1.

16. A system, comprising: an alkaline clean and rinse station; an acid coating station positioned downstream of the alkaline clean and rinse station for accepting a metal strip from the alkaline clean and rinse station, wherein the acid coating station includes an applicator configured to apply the acid coating at a rate of 0.1 grams per minute to 10 grams per minute; and an adhesion promoter system positioned downstream of the acidic coating station.

17. The system of claim 16, further comprising a pre-heating oven positioned downstream from the adhesion promoter system, and a protective layer application system positioned downstream of the pre-heating oven for accepting the metal strip at a pre-heating temperature and applying a protective layer to an adhesion promoter layer on a first side of the metal strip, wherein the first side of the metal strip corresponds to an exterior-facing side of a can end formed from the metal strip.

18. The system of claim 16, wherein the metal strip is an aluminum strip, wherein the alkaline rinse station is positioned between the alkaline clean station and the acid coating station.

19. The system of claim 16, wherein there is no rinse station disposed between the acid coating station and the adhesion promoter system.

20. The system of claim 16, wherein the acid coating station comprises a spray application, a roll-on system, a wipe-on system, or a combination thereof.

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