Coating composition and coated label

Abstract

The present disclosure provides a coating composition containing (A) a waterborne polyurethane dispersion; (B) a silica; and (C) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating composition. The present disclosure also provides a coated label including (A) a polymeric substrate having a top surface and an opposing bottom surface, (B) an adhesive layer in contact with the bottom surface of the polymeric substrate; and (C) a coating layer in contact with the top surface of the polymeric substrate, the coating layer containing (i) a waterborne polyurethane dispersion; (ii) a silica; and (iii) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating layer.

Description

COATING COMPOSITION AND COATED LABEL BACKGROUND

[0001] The present disclosure is directed to coating compositions for labels.

[0002] Labels that are printable with vibrant colors that maintain their vibrancy under harsh conditions, such as cold temperatures and chemical exposure, are desired for use in laboratory and commercial settings. Labels printed with vibrant colors are easier to read and are more visually attractive. Labels that are easier to read are safer to use in laboratory and commercial settings, where the printing may include vital safety information. If the label’s vibrancy fades over time, or after being exposed to harsh conditions, it can result in a label that is difficult or impossible to read, which can be dangerous.

[0003] The art recognizes a need for labels that can be printed with a machine printer, such as an inkjet printer, to form vibrant graphics on the label that are easy to read and do not diminish in vibrancy over time, or after being exposed to extremely cold conditions (such as cryogenic conditions). The art also recognizes the need for labels that can be printed with a machine printer, such as an inkjet printer, to form graphics on the label that do not become illegible or come off after being exposed to chemicals (such as ethanol, a common chemical used in laboratories). SUMMARY

[0004] The present disclosure provides a coating composition. In an embodiment, the coating composition contains (A) a waterborne polyurethane dispersion; (B) a silica; and (C) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating composition.

[0005] The present disclosure also provides a coated label. In an embodiment, the coated label includes (A) a polymeric substrate having a top surface and an opposing bottom surface; (B) an adhesive layer in contact with the bottom surface of the polymeric substrate; and (C) a coating layer in contact with the top surface of the polymeric substrate, the coating layer containing (i) a waterborne polyurethane dispersion; (ii) a silica; and (iii) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating layer.

[0006] The present disclosure also provides a printed coated label. In an embodiment, the printed coated label includes (A) a polymeric substrate having a top surface and an opposing bottom surface; (B) an adhesive layer in contact with the bottom surface of the polymeric substrate; (C) a coating layer in contact with the top surface of the polymeric substrate, the coating layer formed from a coating composition containing (i) a waterborne polyurethane dispersion; (ii) a silica; and (iii) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating composition; and (D) an ink layer in contact with the coating layer.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A is photographs of EX 1–5 taken before and after 72 to 96 hours aging in 66°C and 80% relative humidity.

[0008] Figure 1B is photographs of EX 6–9 and B-7425J taken before and after 72 to 96 hours aging in 66°C and 80% relative humidity.

[0009] Figure 2A is photographs of EX 1–5 taken before and after 30 days aging in -40°C.

[0010] Figure 2B is photographs of EX 6–9 and B-7425J taken before and after aging in -40°C.

[0011] Figure 3A is photographs of EX 1–5 taken during Ethanol Chemical Resistance testing (Method 1), on day one and day fourteen.

[0012] Figure 3B is photographs of EX 1, EX 6, EX 7, and B-7425J taken during Ethanol Chemical Resistance testing (Method 1), on day one.

[0013] Figure 4A is photographs of EX 1–5 taken during Ethanol Chemical Resistance testing (Method 2), on day one and day fourteen.

[0014] Figure 4B is photographs of EX 1, EX 6, EX 7, and B-7425J taken during Ethanol Chemical Resistance testing (Method 1), on day one.

[0015] Figure 5 is a schematic of a coated label in accordance with an embodiment of the present disclosure.

[0016] Figure 6 is a schematic of a printed coated label in accordance with an embodiment of the present disclosure.

[0017] Figure 7 is a perspective view of a coated label in accordance with an embodiment of the present disclosure. DEFINITIONS AND TEST METHODS

[0018] For purposes of United States patent practice, the contents of any referenced patent, patent application or publication are incorporated by reference in their entirety (or its equivalent US version is so incorporated by reference) especially with respect to the disclosure of definitions (to the extent not inconsistent with any definitions specifically provided in this disclosure) and general knowledge in the art.

[0019] The numerical ranges disclosed herein include all values from, and including, the lower and upper value. For ranged containing explicit values (e.g., 1 or 2; or 3 to 5; or 6; or 7), any subrange between any two explicit values is included (e.g., 1 to 2; 2 to 6; 5 to 7; 3 to 7; 5 to 6; etc.).

[0020] Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percents are based on weight and all test methods are current as of the filing date of this disclosure.

[0021] The terms “comprising,” “including,” “having,” and their derivatives, are not intended to exclude the presence of any additional component, step, or procedure, whether or not the same is specifically disclosed. In order to avoid any doubt, all articles claimed through use of the term “comprising” may include any additional component, feature, or element, unless stated to the contrary. In contrast, the term, “consisting essentially of” excludes from the scope of any succeeding recitation any other component, step, or procedure, excepting those that are not essential to operability. The term “consisting of” excludes any component, step, or procedure not specifically delineated or listed. The term “or,” unless stated otherwise, refers to the listed members individually as well as in any combination. Use of the singular includes use of the plural and vice versa. As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably.

[0022] The term “composition” refers to a mixture of materials which comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0023] “Anionic” refers to a compound or composition that has a negative net charge.

[0024] An “aziridine” is a chemical that contains at least one aziridine functional group. An aziridine functional group is a three-membered heterocycle with one amine (>N—) and two methylene bridges (>C<). An aziridine that contains two aziridine functional groups is a di- functional aziridine. An aziridine that contains three aziridine functional groups is a tri- functional aziridine

[0025] A “carbodiimide” is a chemical that contains at least one carbodiimide functional group represented by the formula —N=C=N—.

[0026] A “continuous layer” is a layer that extends from each edge of a surface to the opposing edge, without any gaps or voids.

[0027] “Contact” refers to direct contact and indirect contact.

[0028] “Direct contact” means a layer configuration whereby a first layer is located immediately adjacent to a second layer and no intervening layers or no intervening structures are present between the first layer and the second layer.

[0029] A “discontinuous layer” is a layer that is not continuous. Nonlimiting examples of discontinuous layers include a striped layer, a layer in the shape of a graphic image, a dotted layer, and combinations thereof.

[0030] The term, “ethylene-based polymer,” as used herein, refers to a polymer that comprises, in polymerized form, at least 50 wt% or a majority amount of ethylene monomer (based on the weight of the polymer), and optionally may comprise one or more comonomers. In oneembodiment, the ethylene-based polymer comprises a majority amount of ethylene monomer (based on the weight of the ethylene-based polymer), and optionally may comprise one or more comonomers.

[0031] “Facial surface”, “planar surface”, “top surface”, “bottom surface” and the like are used in distinction to “edge surface”. If rectangular in shape or configuration, an article, e.g., a layer or film, will comprise two opposing facial surfaces joined by four edge surfaces (two opposing pairs of edge surfaces, each pair intersecting the other pair at right angles). If circular in configuration, then the article will comprise two opposing facial surfaces joined by one continuous edge surface.

[0032] The term “hydrocarbon,” as used herein, refers to a chemical group containing only hydrogen atoms and carbon atoms.

[0033] “Hydrophilic” refers to a compound or composition that can mix and interact with water.

[0034] “Hydrophobic” refers to a compound or composition that is not soluble in water and repels water.

[0035] “Indirect contact” means a layer configuration whereby a first layer is located adjacent to a second layer and at least one intervening layer or intervening structure is present between the first layer and the second layer.

[0036] “Ink” and like terms mean a coatable or printable formulation that can and usually does contain a dye and / or pigment. A nonlimiting example of a suitable ink is inkjet ink.

[0037] An isocyanate is a chemical that contains at least one isocyanate group in its structure. An isocyanate group (or NCO) is represented by the formula: —N=C=O. An isocyanate that has two isocyanate groups is a di-isocyanate and an isocyanate that has three isocyanate groups is a tri-isocyanate, etc. An isocyanate may be aromatic or aliphatic. In an embodiment, the isocyanate component is selected from a mono-isocyanate, a di-isocyanate, a tri-isocyanate, and combinations thereof.

[0038] “Layer” and like terms, as used herein, mean a single thickness, coating, or stratum of a compound, polymer, or composition spread out or covering a surface. A layer may be continuous or discontinuous.

[0039] “Lipophobic” refers to a compound or composition that is not soluble in lipids or other non-polar solvents.

[0040] “Nonionic” refers to a compound or composition that has no net charge.

[0041] “Pigment” and like terms mean a visible light absorbing material or compound that is present in a non-molecularly dispersed (particulate) form.

[0042] A “polyester” is a polymer in which the polymer units are linked by ester groups. A nonlimiting example of a polyester is polyethylene terephthalate (PET).

[0043] A “polygon” is a closed-plane figure bounded by at least three sides. The polygon can be a regular polygon, or an irregular polygon having three, four, five, six, seven, eight, nine, ten, or more sides. Nonlimiting examples of suitable polygonal shapes include triangle, square, rectangle, diamond, trapezoid, parallelogram, hexagon, and octagon.

[0044] “Polymer” and like terms, as used herein, refer to a polymeric compound prepared by polymerizing monomers, whether of the same or a different type. The generic term polymer thus embraces the term homopolymer (employed to refer to polymers prepared from only one type of monomer, with the understanding that trace amounts of impurities can be incorporated into the polymer structure), and the term interpolymer as defined hereinafter. Trace amounts of impurities, for example, catalyst residues, may be incorporated into and / or within the polymer. It also embraces all forms of interpolymers, e.g., random, block, homogeneous, heterogeneous, etc.

[0045] A “polyurethane” is a polymer formed of hydrocarbon units joined by urethane links (—NH—(C=O)—O—).

[0046] A “polyurethane dispersion” is an emulsion containing polyurethane particles dispersed in a solvent, such as water. A nonlimiting example of a polyurethane dispersion is PrintRite DP 378, available from The Lubrizol Corporation.

[0047] “Propylene-based polymer” as used herein, refers to a polymer that comprises, in polymerized form, a majority weight percent (wt%) of propylene monomer (based on the total weight of the polymer), and optionally may comprise one or more comonomers.

[0048] “Silica” is an oxide of silicon with the chemical formula SiO2. The silica may be organic silica or synthetic silica. The silica may be crystalline silica or amorphous silica. A nonlimiting example of an organic crystalline silica is quartz. Nonlimiting examples of synthetic amorphous silica include fumed silica, silica gel, precipitated silica, and colloidal silica.

[0049] A “vinyl” is a chemical that contains at least one vinyl group. A vinyl group is represented by the formula: —CH=CH2.

[0050] A “waterborne polyurethane dispersion” is a polyurethane dispersion in which the solvent is water. A nonlimiting example of a waterborne polyurethane dispersion is PrintRite DP 378, available from The Lubrizol Corporation.

[0051] Average particle size of the silica is measured in accordance with ASTM C721-20.

[0052] Color density is measured in accordance with CIE94 of ASTM D2244-21.

[0053] Glass transition temperature (Tg) is measured according to ASTM-D3418-15.

[0054] Isocyanate group (NCO) content by weight is measured in accordance with ASTM D5155. DETAILED DESCRIPTION

[0055] The present disclosure provides a coating composition. In an embodiment, the coating composition includes (A) a waterborne polyurethane dispersion; (B) a silica; and (C) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating composition.

[0056] In another embodiment, the coating composition includes (A) a waterborne polyurethane dispersion; (B) a silica; and (C) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating composition; and (D) an optional additive. A. Waterborne Polyurethane Dispersion

[0057] The coating composition includes a waterborne polyurethane dispersion.

[0058] The waterborne polyurethane dispersion includes a polyurethane dispersed in water.

[0059] In an embodiment, the polyurethane is hydrophobic. In other words, the polyurethane is not hydrophilic.

[0060] In an embodiment, the polyurethane is lipophobic.

[0061] In an embodiment, the polyurethane is nonionic.

[0062] In an embodiment, the waterborne polyurethane dispersion contains a polyurethane that is hydrophobic and lipophobic. In a further embodiment, the waterborne polyurethane dispersion contains a polyurethane that is hydrophobic, lipophobic, and nonionic.

[0063] The polyurethane, or further the waterborne polyurethane dispersion, has a glass transition temperature (Tg) of from -70°C to 25°C, or from -70°C to 0°C, or from -60°C to - 20°C, or from -60°C to -40°C, or from -50°C to -40°C. In a further embodiment, the polyurethane, or further the waterborne polyurethane dispersion, has a Tg of from -70°C, or - 60°C, or -55°C, or -50°C, or -49°C to -45°C, or -40°C, or -35°C, or -30°C, or -20°C, or -10°C, or 0°C, or 10°C, or 20°C, or 25°C.

[0064] In an embodiment, the waterborne polyurethane dispersion contains polyurethane in an amount of from 10 wt% to 75 wt%, or from 10 wt% to 50 wt%, or from 20 wt% to 50 wt%, or from 20 wt% to 40 wt%, or from 30 wt% to 40 wt%, based on the total weight of the waterborne polyurethane dispersion. In a further embodiment, the waterborne polyurethane dispersion contains from 10 wt%, or 15 wt%, or 20 wt%, or 25 wt%, or 30 wt%, or 35 wt% to 40 wt%, or 45 wt%, or 50 wt%, or 60 wt%, or 70 wt%, or 75 wt% polyurethane, based on the total weight of the waterborne polyurethane dispersion.

[0065] In an embodiment, the waterborne polyurethane dispersion contains a polyurethane that is hydrophobic and lipophobic. In a further embodiment, the waterborne polyurethanedispersion contains a polyurethane that is hydrophobic, lipophobic, and nonionic. In a further embodiment, the polyurethane, or further the waterborne polyurethane dispersion, has a Tg of from -70°C to 25°C, or from -70°C to 0°C, or from -60°C to -20°C, or from -60°C to -40°C, or from -50°C to -40°C. In some embodiments, the waterborne polyurethane dispersion contains polyurethane in an amount of from 10 wt% to 75 wt%, or from 10 wt% to 50 wt%, or from 20 wt% to 50 wt%, or from 20 wt% to 40 wt%, or from 30 wt% to 40 wt%, based on the total weight of the waterborne polyurethane dispersion.

[0066] In an embodiment, the waterborne polyurethane dispersion is PrintRite DP 378, available from The Lubrizol Corporation.

[0067] The waterborne polyurethane dispersion may comprise two or more embodiments disclosed herein. B. Silica

[0068] The coating composition includes a silica.

[0069] In an embodiment, the silica is a synthetic silica. In another embodiment, the silica is an amorphous silica. In a further embodiment, the silica is a synthetic amorphous silica. Nonlimiting examples of suitable synthetic amorphous silica include fumed silica, silica gel, precipitated silica, colloidal silica, and combinations thereof. A nonlimiting example of a suitable synthetic amorphous silica is Syloid W 300, available from W.R. Grace & Co.-Conn.

[0070] In an embodiment, the silica is a powder.

[0071] In an embodiment, the silica has an average particle size of from 1 μm to 15 μm, or from 1 μm to 10 μm, or from 2 μm to 9 μm, or from 4 μm to 8 μm, or from 5 μm to 7 μm. In a further embodiment, the silica has an average particle size of from 1 μm, or 2 μm, or 3 μm, or 4 μm, or 5 μm to 7 μm, or 8 μm, or 9 μm, or 10 μm, or 12 μm, or 15 μm.

[0072] In an embodiment, the silica is a synthetic amorphous silica having an average particle size of from 1 μm to 15 μm, or from 1 μm to 10 μm, or from 2 μm to 9 μm, or from 4 μm to 8 μm, or from 5 μm to 7 μm.

[0073] In an embodiment, the silica is Syloid W 300, available from W.R. Grace & Co.-Conn.

[0074] The silica may comprise two or more embodiments disclosed herein. C. Crosslinking Agent

[0075] The coating composition includes a crosslinking agent. A “crosslinking agent” is a compound or composition that is a reagent with at least two reactive ends capable of chemically attaching to polyurethane molecules.

[0076] Nonlimiting examples of suitable crosslinking agents include hydrophilic isocyanates, carbodiimides, aziridines, polyamide epichlorohydrins, methylated melamines, and combinations thereof.

[0077] In an embodiment, the crosslinking agent is selected from a hydrophilic isocyanate, a carbodiimide, an aziridine, or a combination thereof.

[0078] In an embodiment, the crosslinking agent is selected from a hydrophilic isocyanate, a hydrophilic carbodiimide, an aziridine, or a combination thereof.

[0079] In an embodiment, the crosslinking agent is selected from a hydrophilic isocyanate, an aziridine, or a combination thereof.

[0080] In an embodiment, the crosslinking agent is a hydrophilic isocyanate. In a further embodiment, the crosslinking agent is a hydrophilic aliphatic polyisocyanate. Nonlimiting examples of suitable hydrophilic aliphatic polyisocyanates include Bayhydur 2547, Bayhydur Ultra 2487 / 1, Bayhydur Ultra 304, and Bayhydur Ultra 3100, each available from Covestro LLC. In a further embodiment, the hydrophilic aliphatic polyisocyanate is a hydrophilic aliphatic polyisocyanate based on hexamethylene diisocyanate (HDI) (e.g., Bayhydur 2547).

[0081] In an embodiment, the crosslinking agent is a hydrophilic isocyanate. In a further embodiment, the crosslinking agent is a hydrophilic aliphatic polyisocyanate. In a further embodiment, the hydrophilic isocyanate, or further the hydrophilic aliphatic polyisocyanate, has an NCO content of from 10% to 50%, or from 15% to 40%, or from 15% to 30%, or from 20% to 30%, or from 20% to 25%. In a further embodiment, the hydrophilic isocyanate, or further the hydrophilic aliphatic polyisocyanate, has an NCO content of from 10%, or 15%, or 20%, or 22% to 23%, or 25%, or 30%, or 35%, or 40%, or 45%, or 50%.

[0082] In an embodiment, the crosslinking agent is a hydrophilic isocyanate. In a further embodiment, the crosslinking agent is a hydrophilic aliphatic polyisocyanate. In a further embodiment, the hydrophilic isocyanate, or further the hydrophilic aliphatic polyisocyanate, or further the hydrophilic aliphatic polyisocyanate based on HDI, has an NCO content of from 10% to 50%, or from 15% to 40%, or from 15% to 30%, or from 20% to 30%, or from 20% to 25%. In a further embodiment, the hydrophilic isocyanate, or further the hydrophilic aliphatic polyisocyanate, or further the hydrophilic aliphatic polyisocyanate based on HDI, has an NCO content of from 10%, or 15%, or 20%, or 22% to 23%, or 25%, or 30%, or 35%, or 40%, or 45%, or 50%. In a further embodiment, the hydrophilic isocyanate, or further the hydrophilic aliphatic polyisocyanate, or further the hydrophilic aliphatic polyisocyanate based on HDI, has a monomeric HDI content of from greater than 0 wt% to less than 0.5 wt%, based on the total weight of the hydrophilic aliphatic polyisocyanate based on HDI.

[0083] In an embodiment, the crosslinking agent is a carbodiimide. In an embodiment, the carbodiimide is a hydrophilic carbodiimide. A nonlimiting example of a suitable carboiimide is Zoldine XL 29SE (CAS No. 667905-24-0), available from Angus Chemical Company. Nonlimiting examples of suitable hydrophilic carbodiimides include Carbodilite V-02-L2, Carbodilite E-05, and Carbodilite E-02, each available from Nisshinbo Chemical Inc.

[0084] In an embodiment, the crosslinking agent is an aziridine. A nonlimiting example of a suitable aziridine is a tri-functional aziridine. Nonlimiting examples of suitable tri-functional aziridines include trimethylolpropane tris(2-methyl-1-aziridine propionate) (CAS No. 64265- 57-2) and pentaerythritol tris (3-(1-aziridinyl) propionate (CAS No. 57116-45-7). A nonlimiting example of a suitable trimethylolpropane tris(2-methyl-1-aziridine propionate) is PZ-28, available from PolyAziridine LLC. A nonlimiting example of a suitable pentaerythritol tris (3-(1-aziridinyl) propionate is PZ-33, available from PolyAziridine LLC.

[0085] In an embodiment, the crosslinking agent is an aziridine. In a further embodiment, the crosslinking agent is an ethylene imine based tri-functional polyaziridine. In a further embodiment, the ethylene imine based tri-functional polyaziridine is pentaerythritol tris (3-(1- aziridinyl) propionate. In an embodiment, the aziridine, or further the ethylene imine based tri- functional polyaziridine, or further the pentaerythritol tris (3-(1-aziridinyl) propionate, has an aziridine functionality of at least 3, or of from 3 to 4, or from 3 to 5.

[0086] In an embodiment, the crosslinking agent is a polyamide epichlorohydrin (PAE). Nonlimiting examples of suitable PAE include Polycup 172, Polycup 8210, Polycup 5150, and Polycup 1884, available from Solenis LLC.

[0087] In an embodiment, the crosslinking agent is a methylated melamine. Nonlimiting examples of methylated melamines include methylated monomeric melamine resin (e.g., Cymel 350, available from Allnex GMBH) and methylated high imino melamine (e.g., Cymel 323, Cymel 325, Cymel 327, Cymel 328, and Cymel 385, each available from Allnex GMBH).

[0088] In an embodiment, the crosslinking agent is selected from a hydrophilic aliphatic polyisocyanate, an ethylene imine based tri-functional polyaziridine, a hydrophilic carbodiimide, and a combination thereof.

[0089] In an embodiment, the crosslinking agent is selected from a hydrophilic aliphatic polyisocyanate, an ethylene imine based tri-functional polyaziridine, and a combination thereof.

[0090] In an embodiment, the crosslinking agent is selected from a hydrophilic aliphatic polyisocyanate, an ethylene imine based tri-functional polyaziridine, a hydrophilic carbodiimide, and a combination thereof.

[0091] The crosslinking agent may comprise two or more embodiments disclosed herein. D. Optional Additive

[0092] In some embodiments, the coating composition includes an optional additive.

[0093] Nonlimiting examples of suitable optional additives include surfactants, dispersing agents, rheology modifiers, solvents, and combinations thereof.

[0094] In an embodiment, the coating composition includes a surfactant. Nonlimiting examples of surfactants include anionic surfactants, cationic surfactants, nonionic surfactants, and Zwitterionic surfactants. In an embodiment, the surfactant is a nonionic surfactant. A nonlimiting example of a nonionic surfactant is isopropyl alcohol (e.g., Surfynol 104Pa, available from Evonik Corporation). Nonlimiting examples of suitable surfactants include isopropyl alcohol (e.g., Surfynol 104Pa, available from Evonik Corporation), polyether- modified polydimethylsiloxane (e.g., Byk-3455, available from Byk-Chemic GmbH), and combinations thereof.

[0095] A nonlimiting example of a suitable dispersing agent is a modified styrene maleic acid copolymer (e.g., Disperbyk-190, available from Byk-Chemic GmbH).

[0096] Nonlimiting examples of suitable solvents include deionized water, triethylamine, and combinations thereof.

[0097] Nonlimiting examples of suitable rheology modifiers include hydrophobically modified ethylene oxide urethane (e.g., Acrysol RM-12W, available from The Dow Chemical Company) and a sodium salt of an acrylic copolymer (e.g., Texipol 63-934, available from ScottBader Co. Ltd.).

[0098] In an embodiment, the coating composition contains surfactants, dispersing agents, solvents, and combinations thereof. In a further embodiment, the coating composition contains isopropyl alcohol, polyether-modified polydimethylsiloxane, a modified styrene maleic acid copolymer, and deionized water. In another embodiment, the coating composition contains isopropyl alcohol, polyether-modified polydimethylsiloxane, and deionized water.

[0099] The optional additive may comprise two or more embodiments disclosed herein. E. Coating Composition

[0100] The coating composition includes (A) the waterborne polyurethane dispersion; (B) the silica; and (C) from 0.5 wt% to 10 wt% of the crosslinking agent, based on the total weight of the coating composition.

[0101] In some embodiments, the coating composition includes (A) the waterborne polyurethane dispersion; (B) the silica; and (C) from 0.5 wt% to 10 wt% of the crosslinking agent, based on the total weight of the coating composition, and (D) an optional additive.

[0102] In an embodiment, the coating composition has a P:B ratio (or Pigment-to-Binder ratio) of from 0.7:1.0 to 1.4:1.0. The “P:B ratio” is the weight ratio of silica to polyurethane present in the coating composition. In an embodiment, the coating composition has a P:B ratio of from 0.7:1.0, or 0.8:1.0, or 1.0:1.0 to 1.1:1.0, or 1.2:1.0. In another embodiment, the coating composition has a P:B ratio of from 0.7:1.0 to 1.2:1.0, or from 0.7:1.0 to 1.1:1.0; or from 0.7:1.0 to 1.0:1.1; or from 0.7:1.0 to 0.9:1.0; or from 0.7:1.0 to 0.8:1.0; or from 0.8:1.0 to 1.2:1.0; or from 0.8:1.0 to 1.1:1.0; or from 0.8:1.0 to 1.0:1.0; or from 0.8:1.0 to 0.9:1.0; or from 0.9:1.0 to 1.2:1.0; or from 0.9:1.0 to 1.1:1.0; or from 0.9:1.0 to 1.0:1.0; or from 1.0:1.0 to 1.2:1.0; or from 1.0:1.0 to 1.1:1.0; or from 1.1:1.0 to 1.2:1.0. In a further embodiment, the coating composition has a P:B ratio of 1.06:1.

[0103] In an embodiment, the coating composition contains from 35 wt% to 80 wt%, or from 40 wt% to 70 wt%, or from 40 wt% to 65 wt%, or from 40 wt% to 60 wt%, or from 40 wt% to 55 wt% of the waterborne polyurethane dispersion, based on the total weight of the coating composition. In a further embodiment, the coating composition contains from 35 wt%, or 40 wt%, or 41 wt%, or 44 wt% to 50 wt%, or 51 wt%, or 55 wt%, or 60 wt%, or 65 wt%, or 70 wt%, or 75 wt%, or 80 wt% of the waterborne polyurethane dispersion, based on the total weight of the coating composition.

[0104] In an embodiment, the coating composition contains from 10 wt% to 50 wt%, or from 15 wt% to 40 wt%, or from 20 wt% to 40 wt%, or from 25 wt% to 40 wt%, or from 30 wt% to 40 wt%, or from 30 wt% to 35 wt% silica, based on the total weight of the coating composition. In another embodiment, the coating composition contains from 10 wt%, or 15 wt%, or 20 wt%, or 25 wt%, or 30 wt% to 35 wt%, or 40 wt%, or 50 wt% silica, based on the total weight of the coating composition.

[0105] The coating composition contains from 0.5 wt% to 10 wt% of the crosslinking agent, based on the total weight of the coating composition. In a further embodiment, the coating composition contains from 0.5 wt% to 5 wt%, or from 0.75 wt% to 4 wt%, or from 0.8 wt% to 3 wt%, or from 0.8 wt% to 2.6 wt%, or from 0.5 wt% to 9 wt%, or from 0.75 wt% to 9 wt%, or from 0.9 wt% to 9 wt%, or from 1 wt% to 10 wt%, or from 1 wt% to 9 wt%, or from 2 wt% to 9 wt%, or from 5 wt% to 10 wt%, or from 5 wt% to 9 wt% crosslinking agent, based on the total weight of the coating composition. In a further embodiment, the coating composition contains from 0.5 wt%, or 0.6 wt%, or 0.7 wt%, or 0.8 wt%, or 0.9 wt%, or 1.0 wt% to 2 wt%, or 2.6 wt%, or 2.8 wt% or 3 wt%, or 4 wt%, or 5 wt%, or 6 wt%, or 7 wt%, or 8 wt%, or 9 wt%, or 10 wt% crosslinking agent, based on the total weight of the coating composition.

[0106] In an embodiment, the coating composition contains from 0.1 wt% to 5 wt%, or from 0.1 wt% to 3 wt%, or from 0.1 wt% to 1.0 wt%, or from 0.5 wt% to 0.9 wt% dispersing agent, based on the total weight of the coating composition. In a further embodiment, the coating composition contains from 0.1 wt%, or 0.2 wt%, or 0.3 wt%, or 0.4 wt%, or 0.5 wt%, or 0.7 wt% to 0.8 wt%, or 1.0 wt%, or 2 wt%, or 3 wt%, or 4 wt%, or 5 wt% dispersing agent, based on the total weight of the coating composition.

[0107] In an embodiment, the coating composition contains from 0.1 wt% to 5 wt%, or from 0.1 wt% to 3 wt%, or from 0.1 wt% to 1.0 wt%, or from 0.5 wt% to 0.9 wt% surfactant, based on the total weight of the coating composition. In a further embodiment, the coating composition contains from 0.1 wt%, or 0.2 wt%, or 0.3 wt%, or 0.4 wt%, or 0.5 wt%, or 0.6 wt% to 0.7 wt%, or 1.0 wt%, or 2 wt%, or 3 wt%, or 4 wt%, or 5 wt% surfactant, based on the total weight of the coating composition.

[0108] In an embodiment, the crosslinking agent is a carbodiimide, or further a hydrophilic carbodiimide. In a further embodiment, the coating composition has a pH greater than 8.00, or greater than 8.50. In another embodiment, the coating composition has a pH of from greater than 8.00 to 12.00, or from greater than 8.00 to 11.00, or from greater than 8.00 to 10.00, or from greater than 8.00 to 9.00, or from 8.50 to 9.00, or from 8.75 to 9.00. In a further embodiment, the coating composition has a pH of from greater than 8.00, or from 8.50, or from 8.75, or from 8.80 to 9.00, or 9.25, or 9.50, or 9.75, or 10.00, or 10.50, or 11.00, or 11.50, or 12.00.

[0109] In an embodiment, the coating composition contains from 0 wt% to 50 wt%, or from greater than 0 wt% to 50 wt%, or from greater than 0 wt% to less than 50 wt%, or from 1 wt% to 45 wt%, or from 1 wt% to 40 wt%, or from 1 wt% to 35 wt%, or from 1 wt% to 30 wt%, or from 1 wt% to 25 wt%, or from 1 wt% to 20 wt%, or from 5 wt% to 20 wt%, or from 10 wt% to 20 wt%, or from 15 wt% to 20 wt% optional additive, based on the total weight of the coating composition, such that the amount is a cumulative, or combined, amount of each optional additive included in the coating composition. In another embodiment, the coating composition contains from 0 wt%, or greater than 0 wt%, or 1 wt%, or 5 wt%, or 10 wt%, or 15 wt% to 20 wt%, or 25 wt%, or 30 wt%, or 35 wt%, or 40 wt%, or 45 wt%, or less than 50 wt%, or 50 wt% optional additive, based on the total weight of the coating composition, such that the amount is a cumulative, or combined, amount of each optional additive included in the coating composition. In some embodiments, the optional additive is selected from a dispersing agent, a surfactant, a solvent, and combinations thereof.

[0110] In an embodiment, the coating composition contains (A) from 35 wt% to 80 wt%, or from 40 wt% to 70 wt%, or from 40 wt% to 65 wt%, or from 40 wt% to 60 wt%, or from 40 wt% to 55 wt% of the waterborne polyurethane dispersion; (B) from 10 wt% to 50 wt%, or from 15 wt% to 40 wt%, or from 20 wt% to 40 wt%, or from 25 wt% to 40 wt%, or from 30 wt% to 40 wt%, or from 30 wt% to 35 wt% silica; and (C) 0.5 wt% to 5 wt%, or from 0.75 wt% to 4 wt%, or from 0.8 wt% to 3 wt%, or from 0.8 wt% to 2.6 wt%, or from 0.5 wt% to 9 wt%, or from 0.75 wt% to 9 wt%, or from 0.9 wt% to 9 wt%, or from 1 wt% to 10 wt%, or from 1 wt% to 9 wt%, or from 2 wt% to 9 wt%, or from 5 wt% to 10 wt%, or from 5 wt% to 9 wt% crosslinking agent, based on the total weight of the coating composition; and (D) optionally, an additive. In a further embodiment, the coating composition has one, some, or all of the following properties: (i) a P:B ratio of from 0.7:1.0 to 0.8:1.0; or from 0.8:1.0 to 1.2:1.0; or from 0.8:1.0 to 1.1:1.0; or from 0.8:1.0 to 1.0:1.0; or from 0.8:1.0 to 0.9:1.0; or from 0.9:1.0 to 1.2:1.0; or from 0.9:1.0 to 1.1:1.0; or from 0.9:1.0 to 1.0:1.0; or from 1.0:1.0 to 1.2:1.0; or from 1.0:1.0 to 1.1:1.0; and / or (ii) the waterborne polyurethane dispersion contains a hydrophobic and lipophobic polyurethane; (iii) the silica is a synthetic amorphous silica; and / or (iv) the silica has an average particle size of from 1 μm to 15 μm, or from 1 μm to 10 μm, or from 2 μm to 9 μm, or from 4 μm to 8 μm, or from 5 μm to 7 μm; and / or (v) the crosslinking agent is selected from hydrophilic isocyanates, carbodiimides, aziridines, polyamide epichlorohydrins, methylated melamines, and combinations thereof; and / or (vi) the crosslinking agent is selected from a hydrophilic isocyanate, a hydrophilic carbodiimide, an aziridine, or a combination thereof; and / or (vii) the crosslinking agent is selected from a hydrophilic isocyanate, an aziridine, or a combination thereof; and / or (viii) the crosslinking agent is a hydrophilic isocyanate, or further a hydrophilic aliphatic polyisocyanate; and / or (ix) the hydrophilic isocyanate, or further the hydrophilic aliphatic polyisocyanate, has an NCO content of from 10% to 50%, or from 15% to 40%, or from 15% to 30%, or from 20% to 30%, or from 20% to 25%; and / or(x) the crosslinking agent is an aziridine, or further an ethylene imine based tri- functional polyaziridine; and / or (xi) the crosslinking agent is a carbodiimide, or further a hydrophilic carbodiimide; and / or (xii) the crosslinking agent is a carbodiimide, or further a hydrophilic carbodiimide, and the coating composition has a pH of from greater than 8.00 to 12.00, or from greater than 8.00 to 11.00, or from greater than 8.00 to 10.00, or from greater than 8.00 to 9.00, or from 8.50 to 9.00, or from 8.75 to 9.00; and / or (xiii) the coating composition contains the additive; and / or (xiv) the additive is selected from a surfactant, a dispersing agent, a rheology modifier, a solvent, or a combination thereof; and / or (xv) the additive is selected from a surfactant, a dispersing agent, a solvent, or a combination thereof.

[0111] In an embodiment, the coating composition contains (A) from 35 wt% to 80 wt%, or from 40 wt% to 70 wt%, or from 40 wt% to 65 wt%, or from 40 wt% to 60 wt%, or from 40 wt% to 55 wt% of the waterborne polyurethane dispersion; (B) from 10 wt% to 50 wt%, or from 15 wt% to 40 wt%, or from 20 wt% to 40 wt%, or from 25 wt% to 40 wt%, or from 30 wt% to 40 wt%, or from 30 wt% to 35 wt% silica; and (C) 0.5 wt% to 5 wt%, or from 0.75 wt% to 4 wt%, or from 0.8 wt% to 3 wt%, or from 0.8 wt% to 2.6 wt%, or from 0.5 wt% to 9 wt%, or from 0.75 wt% to 9 wt%, or from 0.9 wt% to 9 wt%, or from 1 wt% to 10 wt%, or from 1 wt% to 9 wt%, or from 2 wt% to 9 wt%, or from 5 wt% to 10 wt%, or from 5 wt% to 9 wt% crosslinking agent; (D) from 0.1 wt% to 5 wt%, or from 0.1 wt% to 3 wt%, or from 0.1 wt% to 1.0 wt%, or from 0.5 wt% to 0.9 wt% dispersing agent; and (E) from 0.1 wt% to 5 wt%, or from 0.1 wt% to 3 wt%, or from 0.1 wt% to 1.0 wt%, or from 0.5 wt% to 0.9 wt% surfactant, based on the total weight of the coating composition. In a further embodiment, the coating composition has a P:B ratio of from 0.7:1.0 to 0.8:1.0; or from 0.8:1.0 to 1.2:1.0; or from 0.8:1.0 to 1.1:1.0; or from 0.8:1.0 to 1.0:1.0; or from 0.8:1.0 to 0.9:1.0; or from 0.9:1.0 to 1.2:1.0; or from 0.9:1.0 to 1.1:1.0; or from 0.9:1.0 to 1.0:1.0; or from 1.0:1.0 to 1.2:1.0; or from 1.0:1.0 to 1.1:1.0.

[0112] It is understood that the total cumulative weight percent of the above-described coating compositions, and every composition disclosed herein, is 100 wt%.

[0113] In an embodiment, the coating composition is void of, or excludes, anionic polyurethane.

[0114] In an embodiment, the coating composition is void of, or excludes, polyvinyl alcohol.

[0115] The coating composition may be formed by combining the polyurethane dispersion, silica, crosslinking agent, and optional additive(s), and mixing the components together, such as with agitation with a Cowells blade.

[0116] The coating composition may comprise two or more embodiments disclosed herein. F. Coated Label

[0117] The present disclosure provides a coated label. In an embodiment, the coated label includes (A) a polymeric substrate having a top surface and an opposing bottom surface; (B) an adhesive layer in contact with the bottom surface of the polymeric substrate; and (C) a coating layer in contact with the top surface of the polymeric substrate, the coating layer containing (i) a waterborne polyurethane dispersion; (ii) a silica; and (iii) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating layer.

[0118] In some embodiments, the coated label includes (A) a polymeric substrate having a top surface and an opposing bottom surface; (B) an adhesive layer in contact with the bottom surface of the polymeric substrate; and (C) a coating layer in contact with the top surface of the polymeric substrate, the coating layer containing (i) a waterborne polyurethane dispersion; (ii) a silica; (iii) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating layer; and (iv) an optional additive.

[0119] In some embodiments, the coated label includes (D) an optional release liner in contact with the adhesive layer.

[0120] The coating layer may be formed from any coating composition disclosed herein. The waterborne polyurethane dispersion, silica, crosslinking agent and optional additive may be any respective waterborne polyurethane dispersion, silica, crosslinking agent, and optional additive disclosed herein. G. Coating Layer

[0121] The coated label includes a coating layer. The coating layer has a top surface and an opposing bottom surface. The bottom surface of the coating layer contacts the top surface of the polymeric substrate.

[0122] The coating layer contains (i) a waterborne polyurethane dispersion; (ii) a silica; (iii) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating layer. In another embodiment, the coating layer contains (i) a waterborne polyurethane dispersion; (ii) a silica; (iii) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating layer; and (iv) an optional additive.

[0123] The coating layer may be formed from any coating composition disclosed herein.

[0124] In an embodiment, the coating layer (after drying) has a thickness of from 10 μm to 100 μm, or from 10 μm to 50 μm, or from 15 μm to 40 μm, or from 20 μm to 30 μm. In another embodiment, the coating layer (after drying) has a thickness of from 10 μm, or 15 μm, or 20 μm, or 25 μm to 30 μm, or 35 μm, or 50 μm, or 75 μm, or 100 μm.

[0125] In an embodiment, the coating layer has a substantially uniform thickness from each edge surface to the opposing edge surface. In a coating layer having substantially uniform thickness from each edge surface to the opposing edge surface, the top surface and the opposing bottom surface extend parallel to each other.

[0126] The coating layer may directly or indirectly contact the polymeric substrate. In an embodiment, the coating layer indirectly contacts the polymeric substrate. In another embodiment, the coating layer directly contacts the polymeric substrate.

[0127] The coating layer is the top facial surface of the coated label. In other words, the top surface of the coated label structure is the top facial surface of the coated label. The coating layer is therefore exposed to ambient environment.

[0128] In an embodiment, the coating layer, or further the coating composition from which the coating layer is formed, has a P:B ratio of from 0.7:1.0 to 1.4:1.0, or from 0.7:1.0 to 1.2:1.0, or from 0.7:1.0 to 1.1:1.0; or from 0.7:1.0 to 1.0:1.1; or from 0.7:1.0 to 0.9:1.0; or from 0.7:1.0 to 0.8:1.0; or from 0.8:1.0 to 1.2:1.0; or from 0.8:1.0 to 1.1:1.0; or from 0.8:1.0 to 1.0:1.0; or from 0.8:1.0 to 0.9:1.0; or from 0.9:1.0 to 1.2:1.0; or from 0.9:1.0 to 1.1:1.0; or from 0.9:1.0 to 1.0:1.0; or from 1.0:1.0 to 1.2:1.0; or from 1.0:1.0 to 1.1:1.0; or from 1.1:1.0 to 1.2:1.0.

[0129] In some embodiments, the coating layer includes an optional additive. In some embodiments, the optional additive is selected from a surfactant, a dispersing agent, a rheology modifier, and combinations thereof. In another embodiment, the coating composition from which the coating layer is formed contains an optional additive selected from a surfactant, a dispersing agent, a rheology modifier, a solvent, and combinations thereof.

[0130] In some embodiments, the waterborne polyurethane dispersion includes a hydrophobic and lipophobic polyurethane.

[0131] In some embodiments, the silica is a synthetic amorphous silica.

[0132] In some embodiments, the crosslinking agent is selected from a hydrophilic isocyanate, a carbodiimide, an aziridine, and combinations thereof. In other embodiments, the crosslinking agent is selected from a hydrophilic isocyanate, a hydrophilic carbodiimide, an aziridine, and combinations thereof. In further embodiments, the crosslinking agent is selected from a hydrophilic isocyanate, an aziridine, and combinations thereof.

[0133] The coating layer may comprise two or more embodiments disclosed herein.H. Polymeric Substrate

[0134] The coated label includes a polymeric substrate having a top surface and an opposing bottom surface.

[0135] The polymeric substrate may be a single-layer or a multi-layer structure. In an embodiment, the polymeric substrate is a single-layer structure containing one layer formed from a polymer.

[0136] In another embodiment, the polymeric substrate is a multi-layer structure containing at least one layer formed from a polymer.

[0137] The polymeric substrate includes at least one layer formed from, or containing, a polymer. Nonlimiting examples of suitable polymers include polyolefins, polyamides, vinyl polymers, and polyesters. In an embodiment, the polymer is a polyester (e.g., PET), a propylene-based polymer (e.g., polypropylene), an ethylene-based polymer, a vinyl polymer (e.g., polyvinyl chloride or “PVC”), or a combination thereof. In a further embodiment, the polymer is a polyester. In another embodiment, the polymer is a propylene-based polymer.

[0138] In an embodiment, the polymeric substrate is a multi-layer structure containing at least one layer formed from a polyester. A nonlimiting example of a suitable multi-layer structure is the label disclosed in U.S. Patent No. 8,920,895, the entire contents of which are hereby incorporated by reference herein. In U.S. Patent No. 8,920,895, a polyester face sheet layer is in contact with a topcoat layer and a detectable layer. In some embodiments, the polymeric substrate is a multi-layer structure including a topcoat in contact with a polyester film, which contacts a detectable layer.

[0139] In an embodiment, the layer (or film) formed from the polymer has a thickness of from 0.5 μm to 15 μm, or from 1 μm to 15 μm, or from 5 μm to 15 μm, or from 10 μm to 15 μm, or from 1 μm to 13 μm, or from 5 μm to 13 μm, or from 10 μm to 13 μm. In another embodiment, the layer (or film) formed from the polymer has a thickness of from 0.5 μm, or 1 μm, or 5 μm, or 10 μm, or 12 μm to 13 μm, or 14 μm, or 15 μm. The thickness of the layer (or film) formed from the polymer excludes the thickness of any other layers or coatings that may be present in a multi-layer polymeric substrate structure.

[0140] In an embodiment, the polymeric substrate has a substantially uniform thickness from each edge surface to the opposing edge surface. In a polymeric substrate having substantially uniform thickness from each edge surface to the opposing edge surface, the top surface and the opposing bottom surface extend parallel to each other.

[0141] In an embodiment, the polymeric substrate is selected from a polyester layer, a propylene-based layer, and a combination thereof.

[0142] The polymeric substrate may comprise two or more embodiments disclosed herein. I. Adhesive Layer

[0143] The coated label includes an adhesive layer in contact with the bottom surface of the polymeric substrate.

[0144] The adhesive layer has a top surface and an opposing bottom surface.

[0145] The adhesive layer may directly or indirectly contact the polymeric substrate.

[0146] In an embodiment, the polymeric substrate directly contacts the adhesive layer. In other words, the bottom surface of the polymeric substrate directly contacts the top surface of the adhesive layer. In another embodiment, the polymeric substrate indirectly contacts the adhesive layer.

[0147] The adhesive layer is used to attach the label to the end-use surface.

[0148] In an embodiment, the adhesive layer is configured to directly contact an end-use surface when the coated label is placed on the end-use surface. In other words, the bottom surface of the adhesive layer is configured to directly contact an end-use surface when the coated label is placed on, or in direct contact with, the end-use surface.

[0149] In an embodiment, the adhesive layer directly contacts the optional release liner, which is described in detail below. In other words, the bottom surface of the adhesive layer directly contacts a top surface of the release liner.

[0150] A nonlimiting example of a suitable adhesive is a pressure-sensitive adhesive (“PSA”). Nonlimiting examples of suitable pressure sensitive adhesives include acrylic-based PSAs, acrylic-hybrid PSAs, rubber-based PSAs, silicone-based PSAs, and combinations thereof. The PSA may be thermoplastic, solvent-based, or water-based.

[0151] In an embodiment, the PSA is an acrylic-based PSA. Acrylic-based PSAs are formed from an acrylic-based polymer. A nonlimiting example of a suitable acrylic-based PSA is LOCTITE™ DURO-TAK 230A, available from Henkel.

[0152] In an embodiment, the PSA is an acrylic-hybrid PSA. Nonlimiting examples of suitable acrylic hybrids include acrylic-rubber hybrid and acrylic-silicone hybrid PSAs. In an embodiment, the acrylic-hybrid PSA is an acrylic-rubber PSA. A nonlimiting example of a suitable acrylic-rubber PSA is LOCTITE™ DURO-TAK AH 115, available from Henkel.

[0153] In an embodiment, the PSA is a rubber-based PSA. Nonlimiting examples of suitable rubber-based PSAs include compositions containing (i) one or more polymers such as styrene- butadiene (SBR), styrenic block copolymer (such as polystyrene-polyisoprene-polystyrene (SIS) or polystyrene-polybutadiene-polystyrene (SBS)), and butyl rubber; and (ii) an optional tackifying resin such as polyisobutylene. Nonlimiting examples of suitable rubber-based PSAsinclude MORSTIK™ 123 and 190, available from The Dow Chemical Company; and Thermogrip™ 9492KN, available from Bostik. In an embodiment, the PSA is a rubber-based PSA containing butyl rubber, such as Thermogrip™ 9492KN.

[0154] In an embodiment, the PSA is selected from an acrylic-based PSA, an acrylic-hybrid PSA, a rubber-based PSA, and combinations thereof.

[0155] In an embodiment, the PSA includes one or more optional additives. A nonlimiting example of a suitable additive is a pigment, such as titanium dioxide.

[0156] Nonlimiting examples of an adhesive are the adhesives disclosed in U.S. Patent No. 8,920,895 and U.S. Publication No. 2019 / 0210391, the entire contents of which are hereby incorporated by reference herein.

[0157] In an embodiment, the adhesive layer has a thickness of from 0.1 μm to 10 μm, or from 0.1 μm to 5 μm, or from 0.1 μm to 3 μm, or from 0.5 μm to 3 μm, or from 0.5 μm to 2 μm. In another embodiment, the adhesive layer has a thickness of from 0.1 μm, or 0.5 μm, or 1 μm to 1.5 μm, or 2 μm, or 3 μm, or 4 μm, or 5 μm, or 8 μm, or 10 μm.

[0158] In an embodiment, the adhesive layer has a substantially uniform thickness from each edge surface to the opposing edge surface. In an adhesive layer having substantially uniform thickness from each edge surface to the opposing edge surface, the top surface and the opposing bottom surface extend parallel to each other.

[0159] The adhesive layer may comprise two or more embodiments disclosed herein. J. Optional Release Liner

[0160] In some embodiments, the coated label includes an optional release liner in contact with the adhesive layer.

[0161] Nonlimiting examples of release liners include glassine paper, laminated paper, differential release liner, polyester film, and polypropylene film, each of which may or may not have been subjected to a coating of silicone.

[0162] In one embodiment the coated label is void of a release liner. In this embodiment the release liner may or may not be replaced with a release coating, e.g., a silicone-based or wax- based material.

[0163] The release liner is removed from the coated label before it is applied to an end-use surface.

[0164] The release liner has a top surface and an opposing bottom surface.

[0165] In an embodiment, the release liner has a thickness of from 10 μm to 400 μm, or from 50 μm to 300 μm, or from 100 μm to 200 μm.

[0166] The optional release liner may comprise two or more embodiments disclosed herein.

[0167] In an embodiment, the coated label includes (A) the polymeric substrate having a top surface and an opposing bottom surface; (B) the adhesive layer in contact with the bottom surface of the polymeric substrate; and (C) the coating layer in contact with the top surface of the polymeric substrate, the coating layer containing (i) the waterborne polyurethane dispersion; (ii) the silica; and (iii) from 0.5 wt% to 10 wt% of the crosslinking agent, based on a total weight of the coating layer. In a further embodiment, the coated label has the following Structure I: Coating Layer / Polymeric Substrate / Adhesive Layer (Structure I).

[0168] Figure 5 is a schematic of a coated label having the Structure I. The coated label 10 has a coating layer 12, a polymeric substrate 14, and an adhesive layer 16. The coating layer 12 directly contacts the polymeric substrate 14. Further, the polymeric substrate 14 directly contact the adhesive layer 16. However, it is understood that in an alternate embodiment, one or more of the layers of Structure I may instead indirectly contact an adjacent layer.

[0169] In an embodiment, as shown in Figure 7, the coated label 10 has a top facial surface 3 and an opposing bottom facial surface 5. The coated label 10 has a front edge surface 7 and an opposing rear edge surface 9. The coated label 10 has a left edge surface 11 and an opposing right edge surface 13. A layer that has substantially uniform thickness has substantially the same thickness extending from the front edge surface 7 to the opposing rear edge surface 9, and from the left edge surface 11 to the opposing right edge surface 13.

[0170] In some embodiments, the coated label includes (A) a polymeric substrate having a top surface and an opposing bottom surface; (B) an adhesive layer in contact with the bottom surface of the polymeric substrate; (C) a coating layer in contact with the top surface of the polymeric substrate, the coating layer containing (i) a waterborne polyurethane dispersion; (ii) a silica; (iii) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating layer; and (D) the release liner in contact with the adhesive layer. In a further embodiment, the coated label has the following Structure II: Coating Layer / Polymeric Substrate / Adhesive Layer / Release Liner (Structure II).

[0171] The polymeric substrate may be formed by extrusion. Optional additives in polymeric substrate (such as pigments) may be added during compounding prior to extrusion, or they may be added inline during extrusion. The polymeric substrate is a film. The film may be a single layer film or a multilayer film. In an embodiment, the polymeric substrate is a single layer film. In another embodiment, the polymeric substrate is a multilayer film, with at least one layer containing a polymer.

[0172] In some embodiments, the adhesive layer is applied to the bottom surface of the polymeric substrate via slot die coating. The coated adhesive layer is then exposed to heat and convective air movement to remove, or substantially remove, solvent and / or water that may be present in the PSA. The slot die coating and heat / air movement exposure steps may be repeated until the desired thickness of the adhesive layer is attained.

[0173] In some embodiments, the adhesive layer is hot-melt coated on the bottom surface of the polymeric substrate. During hot-melt coating, the PSA is placed in a drum unloader, in which the PSA is heated to a target temperature. The PSA is then pumped to a melt tank with a controlled temperature and volume level. A coating head pumps the PSA from the melt tank at a constant rate to maintain a constant layer thickness. The coated adhesive layer is then cooled to room temperature.

[0174] The coating composition may be formed by combining the polyurethane dispersion, silica, crosslinking agent, and optional additive(s), and mixing the components together, such as with agitation with a Cowells blade. The coating composition may then be applied to the polymeric substrate, or further, the top surface of the polymeric substrate. For example, the coating composition may be applied to the top surface of the polymeric substrate with applicator rods, via a multi-thickness 8-path scraper drawdown, knife over roll coating, or slot die coating. The coating layer contacts the top surface of the polymeric substrate and the polymeric substrate contacts the adhesive layer. The coated label is then exposed to heat and convective air movement to remove, or substantially remove, solvent and / or water that may be present in the coating layer.

[0175] In an embodiment, a sheet is formed as described above. Then, the sheet is sliced or die cut into strips or the desired shape, such as a circle, a square, or a rectangle, to form the coated labels. In some embodiments, the strip is wound onto itself to form a roll. In some embodiments, a continuous sheet or strip of release liner contains a plurality of coated labels, wherein each coated label may or may not be in contact with an adjacent coated label.

[0176] In an embodiment, the coated label (after drying) has a total thickness of from 50 μm to 500 μm, or from 50 μm to 300 μm, or from 50 μm to 200 μm, or from 50 μm to 150 μm. In another embodiment, the coated label (after drying) has a thickness of from 50 μm, or 75 μm, or 100 μm to 150 μm, or 200 μm, or 300 μm, or 400 μm, or 500 μm. It is understood that the total thickness of the coated label (after drying) excludes the thickness of the optional release liner. In other words, the total thickness of the coated label (after drying) is the cumulative thickness of the ink layer (described below), the coating layer, the polymeric substrate, and theadhesive layer (and any intermediate layer between the aforesaid layers), but excluding the thickness of the release liner.

[0177] It is understood that during drying, all or substantially all of the water (and any other solvent) present in the coating layer is removed.

[0178] In an embodiment, the coated label has a substantially uniform thickness from each edge surface to the opposing edge surface. In a coated label having substantially uniform thickness from each edge surface to the opposing edge surface, the top surface and the opposing bottom surface extend parallel to each other.

[0179] The coated label has a shape. Nonlimiting examples of suitable shapes include polygon, circle, and irregular. A nonlimiting example of a polygon is a rectangle. Figure 7 depicts a coated label with a rectangle shape.

[0180] The coated label may comprise two or more embodiments disclosed herein. K. Printed Coated Label

[0181] In some embodiments, the coated label is printable.

[0182] A “printable” coated label is a label that is configured to run through a printing machine in its normal operation, and receive and retain ink on or in the coating layer. To constitute a printable coated label, the coated label must have a structure that is capable of being run through a printing machine (e.g., having an appropriate thickness). Further, the coated label’s top facial surface (here, the top surface of the coating layer) should be smooth, or substantially smooth, so as to avoid uneven printing or voids in printing. Moreover, in some embodiments, the coated label should have a substantially uniform thickness from each edge surface to the opposing edge surface.

[0183] In some embodiments, the coated label is printed with an inkjet ink. The inkjet ink is applied to the coating layer in an inkjet printer. Not wishing to be bound by any particular theory, it is believed that at least a portion of the inkjet ink is absorbed by the coating layer.

[0184] It is understood that some or all of the ink may be absorbed by the coating layer, or the ink may form a discrete layer having a top surface and an opposing bottom surface, the bottom surface contacting the coating layer. Regardless of whether the ink is absorbed by the coating layer (partially or completely), the ink deposited by the printer onto the coating layer is herein be referred to as an “ink layer.”

[0185] In an embodiment, the coated label is inkjet printable.

[0186] In an embodiment, the ink layer is formed from inkjet ink. Nonlimiting examples of suitable inkjet ink include the ink colors cyan, magenta, yellow, and black.

[0187] A nonlimiting example of a suitable inkjet printer is a BradyJet J2000 Color Label Printer, available from Brady Corporation. A nonlimiting example of a suitable ink is the BradyJet J2000 Full Color Ink Cartridge (part number J20-CMY).

[0188] The ink layer may directly or indirectly contact the coating layer. In an embodiment, the ink layer directly contacts the coating layer.

[0189] In an embodiment, the ink layer is in the form of a graphic image, such as a pattern (e.g., striped, dotted, etc.), indicia, text, or a combination thereof. For example, the graphic image may be text that says “BIOHAZARD” and the coated label may be placed on an end- use surface, such as a vial, to indicate that the contents of the vial are biohazardous. In another instance, the graphic image may be the image of a triangle shape with an exclamation point therein and the coated label may be used on an end-use surface, such as a drum, to indicate that the drum contains dangerous materials.

[0190] The ink layer may be continuous or discontinuous. A continuous ink layer is present at a substantially uniform thickness from each edge surface to the opposing edge surface of the printed coated label. A discontinuous ink layer has gaps, or voids. A nonlimiting example of a discontinuous ink layer is an ink layer in the shape of a graphic image.

[0191] In some embodiments, the printed coated label may have a plurality, or more than one, or two ink layers. For example, the printed coated label may be printed with a first ink layer in a first color, the first ink layer in contact with the coating layer and the first ink layer being a continuous ink layer. A second ink layer in a second color may then be applied with a printer to be in contact with the first ink layer, and may be a discontinuous layer in the form of a graphic image, for example.

[0192] The ink layer may comprise two or more embodiments disclosed herein.

[0193] In an embodiment, the printed coated label includes (A) a polymeric substrate having a top surface and an opposing bottom surface; (B) an adhesive layer in contact with the bottom surface of the polymeric substrate; (C) a coating layer in contact with the top surface of the polymeric substrate, the coating layer formed from a coating composition containing (i) a waterborne polyurethane dispersion; (ii) a silica; and (iii) from 0.5 wt% to 10 wt% of the crosslinking agent, based on a total weight of the coating composition; and (D) an ink layer in contact with the coating layer. The coating layer may be formed from any coating composition disclosed herein. The waterborne polyurethane dispersion, silica, crosslinking agent and optional additive may be any respective waterborne polyurethane dispersion, silica, crosslinking agent, and optional additive disclosed herein. The polymeric substrate, adhesivelayer, coating layer, and ink layer may be any respective polymeric substrate, adhesive layer, coating layer, and ink layer disclosed herein.

[0194] In an embodiment, the printed coated label includes (A) the polymeric substrate having a top surface and an opposing bottom surface; (B) the adhesive layer in contact with the bottom surface of the polymeric substrate; (C) the coating layer in contact with the top surface of the polymeric substrate, the coating layer formed from a coating composition containing (i) the waterborne polyurethane dispersion; (ii) the silica; and (iii) from 0.5 wt% to 10 wt% of the crosslinking agent, based on a total weight of the coating composition; and (D) an ink layer in contact with the coating layer. In a further embodiment, the printed coated label has the following Structure III: Ink Layer / Coating Layer / Polymeric Substrate / Adhesive Layer (Structure III).

[0195] In some embodiments, the printed coated label includes (A) a polymeric substrate having a top surface and an opposing bottom surface; (B) an adhesive layer in contact with the bottom surface of the polymeric substrate; (C) the coating layer in contact with the top surface of the polymeric substrate, the coating layer formed from a coating composition containing (i) the waterborne polyurethane dispersion; (ii) the silica; and (iii) from 0.5 wt% to 10 wt% of the crosslinking agent, based on a total weight of the coating composition; (D) the ink layer in contact with the coating layer; and (E) the release liner in contact with the adhesive layer. In a further embodiment, the printed coated label has the following Structure IV: Ink Layer / Coating Layer / Polymeric Substrate / Adhesive Layer / Release Liner (Structure IV).

[0196] Figure 6 is a schematic of a printed coated label having the Structure IV. The coated label 100 has an ink layer 120, a coating layer 112, a polymeric substrate 114, an adhesive layer 116, and a release liner 118. The ink layer 120 directly contacts the coating layer 112. The coating layer directly contacts the polymeric substrate 114. The polymeric substrate 114 directly contacts the adhesive layer 116. The adhesive layer 116 directly contacts the release liner 118. It is understood that in an alternate embodiment, one or more of the layers of Structure IV may instead indirectly contact an adjacent layer. While the ink layer 120 is depicted as a distinct layer, it is understood that a portion of, substantially all, or all, of the ink layer 120 may be absorbed into the coating layer 112.

[0197] The structures depicted in Figures 5, 6, and 7 are schematics that are not intended to represent the relative thickness of each layer with respect to the other layers.

[0198] In an embodiment, the printed coated label (after drying) has a total thickness of from 50 μm to 500 μm, or from 50 μm to 300 μm, or from 50 μm to 200 μm, or from 50 μm to 150μm. In another embodiment, the coated label (after drying) has a thickness of from 50 μm, or 75 μm, or 100 μm to 150 μm, or 200 μm, or 300 μm, or 400 μm, or 500 μm. It is understood that the total thickness of the printed coated label (after drying) excludes the thickness of the optional release liner. In other words, the total thickness of the printed coated label (after drying) is the cumulative thickness of the ink layer (described below), the coating layer, the polymeric substrate, and the adhesive layer (and any intermediate layer between the aforesaid layers), but excluding the thickness of the release liner.

[0199] It is understood that during drying, all or substantially all of the water (and any other solvent) present in the coating layer and ink layer is removed.

[0200] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink.

[0201] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a cyan color density of at least 0.7. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a cyan color density of from 0.7 to 1.5, or from 0.7 to 1.0, or from 0.7 to 0.9. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a cyan color density of from 0.7, or 0.8 to 0.9, or 1.0, or 1.5.

[0202] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a magenta color density of at least 0.8. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a magenta color density of from 0.8 to 1.5, or from 0.8 to 1.0. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a magenta color density of from 0.8, or 0.9 to 1.0, or 1.2, or 1.5.

[0203] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a yellow color density of at least 0.8, or at least 1.00. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a yellow color density of from 0.80 to 1.50, or from 0.85 to 1.50, or from 0.89 to 1.50, or from 1.00 to 1.50, or from 1.06 to 1.50, or from 1.07 to 1.20. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a yellow color density of from 0.80, or 0.85, or 0.89, or 0.90, or 0.93, or 0.95, or 1.00, or 1.06, or 1.07, or 1.08 to 1.10, or 1.15, or 1.20, or 1.50.

[0204] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a black color density of at least 0.7, or at least 0.8. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a black color density of from 0.7 to 1.5, or from 0.8 to 1.5, or from 0.8 to 1.0. In a further embodiment, before and after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a black color density of from 0.7, or 0.8, or 0.9 to 1.0, or 1.2, or 1.5.

[0205] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a cyan color density of at least 0.7. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a cyan color density of from 0.7 to 1.5, or from 0.7 to 1.0, or from 0.7 to 0.9. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a cyan color density of from 0.7, or 0.8 to 0.9, or 1.0, or 1.5.

[0206] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a magenta color density of at least 0.8. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a magenta color density of from 0.8 to 1.5, or from 0.8 to 1.2, or from 0.8 to 1.0. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a magenta color density of from 0.8, or 0.9 to 1.0, or 1.2 or 1.5.

[0207] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a yellow color density of at least 0.8, or at least 0.9, or at least 1.0. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a yellow color density of from 0.8 to 1.5, or from 0.9 to 1.2, or from 1.0 to 1.2. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a yellow color density of from 0.8, or 0.9, or 1.0 to 1.1, or 1.2 or 1.5.

[0208] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a black color density of at least 0.7, or at least 0.8. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a black color density of from 0.7 to 1.5, or from 0.8 to 1.2, or from 0.8 to 1.0. In a further embodiment, before and after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a black color density of from 0.7, or 0.8, or 0.9 to 1.0, or 1.2 or 1.5.

[0209] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a total change in color density of less than 3% for each inkjet ink color (cyan, magenta, yellow, and black – or, “CMYK”). In a further embodiment, after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a total change in color density of from 0% to 3%, or from 0% to 2%, or from 0% to 1%, or from 0% to 0.9%, or from 0% to 0.6% for each inkjet ink color (CMYK). In a further embodiment, after 30 days aging in -40°C, the ink layer, or further the inkjet ink, exhibits a total change in color density of from 0%, or 0.1% to 0.2%, or 0.4%, or 0.6%, or 0.8%, or 0.9%, or 1%, or 2%, or less than 3% for each inkjet ink color (CMYK).

[0210] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a total change in color density of less than 13%, or less than 3% for each inkjet ink color (CMYK). In a further embodiment, after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a total change in color density of from 0% to 13%, or from 0% to 3%, or from 0% to 2%, or from 0% to 1%, or from 0% to 0.9%, or from 0% to 0.6% for each inkjet ink color (CMYK). In a further embodiment, after 72 to 96 hours aging in 66°C and 80% relative humidity, the ink layer, or further the inkjet ink, exhibits a total change in color density of from 0%, or 0.1% to 0.2%, or 0.4%, or 0.5%, or 0.8%, or 0.9%, or 1%, or 2%, or 2.5%, or 3%, or 5%, or 10%, or 12%, or 12.6%, or 13% for each inkjet ink color (CMYK).

[0211] It is understood that the total change in color density percentage is the absolute value of the calculated percentage of change in color density between an un-aged sample and an aged sample, tested as described below in the Examples section.

[0212] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, after one day of aging, the ink layer is able to withstand at least 50, or at least 55 rubs, or at least 60 rubs, or at least 70 rubs with 100% ethanol before the ink layer is broken through.

[0213] In an embodiment, the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink. In a further embodiment, after fourteen days of aging, the ink layer is able to withstand at least 50, or at least 55 rubs, or at least 60 rubs, or at least 70 rubs, or at least 80 rubs, or at least 90 rubs, or at least 100 rubs with 100% ethanol before the ink layer is broken through.

[0214] In an embodiment, the crosslinking agent in the coating layer is an aziridine crosslinking agent, such as an ethylene imine based tri-functional polyaziridine, and the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink.

[0215] In an embodiment, the crosslinking agent in the coating layer is a hydrophilic isocyanate, such as a hydrophilic aliphatic polyisocyanate, and the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink.

[0216] In an embodiment, the crosslinking agent in the coating layer is a carbodiimide, such as a hydrophilic carbodiimide, and the printed coated label is an inkjet printed coated label having an ink layer containing inkjet ink.

[0217] The present coated label, and further the printed coated label, are suitable for being applied to an end-use surface. Nonlimiting examples of suitable end-use surfaces include surfaces of vials, beakers, flasks, tubes, graduated cylinders, petri dishes, bottles, drums, containers, shelves, benches, jars, boxes, and barrels. In some embodiments, the end-use surface is the surface of a piece of laboratory equipment, such as a beaker or a graduated cylinder. The end-use surface may be a glass surface, a plastic surface, a metal surface, a cardboard surface, a wood surface, or any other solid surface. The present coated label is suitable for both indoor and outdoor use. When applied, the optional release liner is removed and the label is positioned so that the adhesive layer directly contacts the end-use surface.

[0218] The printed coated label may comprise two or more embodiments disclosed herein.

[0219] By way of example, and not limitation, examples of the present disclosure are provided. EXAMPLES

[0220] The materials used to produce the coating compositions and articles are provided in Table 1A below.

[0221] Glass transition temperature (Tg) of the waterborne polyurethane dispersion (PrintRite DP 378) is measured using a TA Differential Scanning Calorimeter, model 2500, Serial numberDSC2A-01410. A TA Tzero DSC pan and lid were used under the conditions listed in Table 1B.

[0222] The solids content of the synthetic silica is measured using a Mark 3 HP moisture analyzer. Table 1ATable 1B: Tg Temperature Conditions1. Preparation of Coating Compositions

[0223] EX A –EX E: A given amount of waterborne polyurethane dispersion (PrintRite DP 378) is weighed into a lined pint can. Given amounts of Disperbyk-190 and Surfynol 104PA are added into the can and the combination is mixed under slow agitation with a Cowells blade until homogeneous. Then, the synthetic silica (Syloid W 300) is slowly added to the homogeneous mixture, followed by mixing at a speed of 1800 rotations per minutes (RPM) for ten minutes, after which deionized water is added to adjust the desired solids content.

[0224] EX F –EX I: A given amount of waterborne polyurethane dispersion (PrintRite DP 378) is weighed into a lined pint can. Given amounts of Disperbyk-190 and Surfynol 104PA are added into the can and the combination is mixed under slow agitation with a Cowells blade until homogeneous. Then, the synthetic silica (Syloid W 300) is slowly added to the homogeneous mixture, followed by mixing at a speed of 1800 rotations per minutes (RPM) for ten minutes, after which a mixture of deionized water and crosslinking agent (Bayhydur 2547 or PZ-333) is added.

[0225] EX J –EX L: A given amount of waterborne polyurethane dispersion (PrintRite DP 378) is weighed into a lined pint can. Given amounts of Disperbyk-190 and Surfynol 104PA are added into the can and the combination is mixed under slow agitation with a Cowells blade until homogeneous. Then, the synthetic silica (Syloid W 300) is slowly added to the homogeneous mixture, followed by mixing at a speed of 1800 rotations per minutes (RPM) for ten minutes, after which a mixture of deionized water and triethylamine are added and stirred for five minutes. The pH of the mixture is measured with an OAKTON pH 700 pH / ORP / TEMP meter to ensure the mixture has a pH above 8.00. Then, the crosslinking agent (Carbodilite E-05) is added to the mixture and stirred for an additional five minutes. The pH of the mixture is measured again and recorded as the pH of the coating composition.

[0226] Tables 2A and 2B provide the formulation for each coating composition. 2. Preparation of Coated Labels

[0227] The coating compositions prepared as described above are applied to the top surface of the B-492 Freezerbondz label stock (i.e., to the surface opposite the adhesive surface) with Gardco Wire-wound Mayer Wet Film Applicator Rods ranging from 18 to 30 (i.e., from 0.018 to 0.030 inches); followed by baking in an oven for three minutes at 220°F (~104°C). The coating thickness is measured by calculating the mass difference between the coated and uncoated B-492 Freezerbondz label stock to give a total weight percent of the coating at a target of 16 pounds per ream for 1 mil (25.4 μm) of dried coating. Tables 2C and 2D provide the structure for each coated label.

[0228] Coated labels EX A – EX L and Comparative B-7425J labels are cut into 4 inch (10.16 cm) wide strips for testing.

[0229] In Tables 2A and 2B, amounts are listed in wt%, based on the total weight of the coating composition. In each of the example coated labels of Tables 2C and 2D, the coating composition directly contacts the top surface of the label stock (i.e., the surface opposite the release liner and the adhesive layer). Tbl 2A C ti C itiTbl 2B C ti C itiTbl 2C C td Lblμ. . . .3. Service Temperature Color Density

[0230] The service temperature color density of the coated labels prepared as described above is tested by measuring the CIELab color densities on printed samples before and after aging for 72-96 hours in an Espec chamber set to 66°C / 80% relative humidity and 30 days in a Thermo Scientific TSC Series freezer capable of reaching – 40°C. A template including color lines and weathering blocks is printed on the strips with an inkjet printer (a BradyJet J2000 Color Label Printer) equipped with a BradyJet J2000 Full Color Ink Cartridge (part number J20-CMY; Cyan, Magenta, Yellow). Black ink is obtained by combining the cyan, magenta, and yellow ink during the printing process. The printed samples are prepared by removing the release liner from the cut strip and contacting the adhesive layer of the coated label with an aluminum panel, thereby laminating the coated labels to the aluminum panel. The L*a*b* color density of each weathering block on the printed samples is measured using an X-Rite Exact handheld Color Densitometer and is measured before aging and again after aging. Results for samples aged for from 72 to 96 hours in 66°C / 80% relative humidity are reported in Table 3 and Figure 1, and results for samples aged for 30 days in -40°C are reported in Table 4 and Figures 2A and 2B.

[0231] While printing with CMY, color density represents the ink’s ability to absorb light. Typically, a thicker ink layer will have a better ability to absorb light. However, a thicker ink layer requires the use of more materials and can therefore be more expensive to produce. Color density is a measurement of the color vibrancy. The more vibrant the color, the easier is to control color uniformity, and the easier it is for an individual to see what was printed. Consequently, it is advantageous for a printed label to achieve and maintain a high color density, even after aging and / or exposure to certain conditions.

[0232] As shown in Tables 3 and 4, EX 6, EX 7, EX 8, EX 11, and EX 12 and B-7425J each had less than a 3% total change (with difference values falling above 3.0% and below -3.0% falling outside a total change of 3%), across all colors under both tested conditions. This indicates that EX 6, EX 7, EX 8, EX 11, and EX 12 have suitable color density retention for many conditions, including label applications in which the label will be exposed to low temperatures for extended periods of time (e.g., cryogenic applications). As shown in Table 4, EX 9 exhibits less than a 3% total change after aging for 30 days at -40°C, which indicates that EX 9 has suitable color density retention for label applications in which the label will be exposed to low temperatures for extended periods of time (e.g., cryogenic applications).Table 3. Color Density at 66°C / 80% Relative Humidity (72–96 hr Aging). . . .

[0233] Moreover, as shown in Tables 3 and 4, EX 1 (which has a P:B ratio of 1.06:1 and does not contain any crosslinker) exhibits a lower cyan, magenta, and black color density under bothtested conditions and in both the aged and unaged samples relative to EX 6–EX 9 (each of which having a P:B ratio of 1.06:1 but containing a crosslinker). EX 8 exhibits a higher yellow color density than EX 1 under both tested conditions and in both the aged and unaged samples. EX 6–EX 9 each also exhibit higher color densities across all colors under both tested conditions and in both the aged and unaged samples relative to B-7425J. The results suggest that EX 6–EX 9 exhibit sufficient vibrancy across different conditions to be easy for a person to read what is printed on the label without requiring a thicker ink layer to be applied. Table 4. Color Density at -40°C (30 Day Aging). . . .. . . .4. Ethanol Chemical Resistance

[0234] Ethanol chemical resistance of the printed coated labels prepared as described above is measured by removing the release liner from the cut strip and contacting the adhesive layer of the coated label with an aluminum panel and allowing samples to dwell for 24 hours and 14 days at ambient conditions before being exposed to 100% ethanol. Ethanol chemical rub resistance is measured in two separate ways.

[0235] Method 1: Samples are fully immersed in the test solvent for fifteen minutes, removed, and rubbed back-and-forth ten times with a cotton swab saturated with the test solvent. Visual observations are recorded and rated based on the scale in Table 5, with results reported in Table 6 and photographs taken, as shown in Figures 3A and 3B. Table 5. Chemical Rub Resistance Ratingp p p Table 6: Method 1 —100% Ethanol Rub Resistance Resultsyy

[0236] Method 2: Samples are laid flat and the release liner removed so the adhesive is in contact with a platform. A Balanced Beam Scrape Adhesion Tester for Mechanical Double Rubs is used to collect the number of double rubs withstood. The machine is set up with a 50- gram weight and a cut cotton swab tip soaked in 100% ethanol. Double rubs continue until complete break through and all ink removal is achieved or the number of double rubs reaches 100, whichever occurs first. The number of double rubs is reported in Table 7, with photographs and a visual comparison shown in Figuresand 4B. Table 7: Method 2 — 100% Ethanol Rub Resistance Resultsyy

[0237] Resistance to 100% ethanol is advantageous in label applications in which labels may be exposed to ethanol because it minimizes the risk of the data printed on the label being damaged or rendered unreadable.

[0238] As shown in Table 6, EX 6, EX 7, and EX 8 each exhibit only slight ink smear one day after aging. As shown in Table 7, EX 6, EX 7, and EX 8 each withstood over 50 rubs before breakthrough one day after aging, and over 60 rubs before breakthrough fourteen days after aging. The results indicate that EX 6, EX 7, and EX 8 are suitable for use in laboratory conditions where the label may be exposed to ethanol.

[0239] Further, as shown in Table 7, EX 1 (which has a P:B ratio of 1.06:1 and does not contain any crosslinker) requires fewer rubs until breakthrough at Day 1 (10 rubs) relative to each of EX 6–EX 9 (each of which having a P:B ratio of 1.06:1 but containing a crosslinker) (61, 58, 66, and 17 rubs). Likewise, EX 6 and EX 7 each require more rubs until breakthrough at Day 14 (100 rubs each) relative to EX 1 (69 rubs).

[0240] It is specifically intended that the present disclosure not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.

Claims

CLAIMS We Claim:

1. A coating composition comprising: (A) a waterborne polyurethane dispersion; (B) a silica; and (C) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating composition.

2. The coating composition of claim 1, wherein the coating composition has a P:B ratio of from 0.7:1.0 to 1.4:1.

0.

3. The coating composition of claim 1 or claim 2, wherein the waterborne polyurethane dispersion comprises a hydrophobic and lipophobic polyurethane.

4. The coating composition of any of claims 1–3, wherein the silica is a synthetic amorphous silica.

5. The coating composition of any of claims 1–4, wherein the silica has an average particle size of from 1 μm to 15 μm.

6. The coating composition of any of claims 1–5, wherein the crosslinking agent is selected from the group consisting of a hydrophilic isocyanate, a carbodiimide, an aziridine, or a combination thereof.

7. The coating composition of any of claims 1–6, further comprising an additive selected from the group consisting of a surfactant, a dispersing agent, a rheology modifier, a solvent, and combinations thereof.

8. The coating composition of any of claims 1–7, wherein the coating comprises from 0.5 wt% to 5 wt% of the crosslinking agent, based on the total weight of the coating composition.

9. The coating composition of any of claims 1–8, wherein the waterborne polyurethane dispersion has a Tg of from -70°C to 25°C.

10. A coated label comprising: (A) a polymeric substrate having a top surface and an opposing bottom surface; (B) an adhesive layer in contact with the bottom surface of the polymeric substrate; and (C) a coating layer in contact with the top surface of the polymeric substrate, the coating layer comprising (i) a waterborne polyurethane dispersion; (ii) a silica; and(iii) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating layer.

11. The coated label of claim 10, wherein the coating layer has a P:B ratio of from 0.7:1.0 to 1.4:1.

0.

12. The coated label of claim 10 or claim 11, wherein the coated label is printable.

13. The coated label of claim 12, wherein the coated label is inkjet printable.

14. The coated label of any of claims 10–13, wherein the coating layer further comprises an additive selected from the group consisting of a surfactant, a dispersing agent, a rheology modifier, and combinations thereof.

15. The coated label of any of claims 10–14, wherein the coating layer is printed with an inkjet ink; and after 30 days aging in -40°C, the inkjet ink exhibits a total change in color density of less than 3% for each inkjet ink color (CMYK).

16. The coated label of any of claims 10–15, wherein the waterborne polyurethane dispersion comprises a hydrophobic and lipophobic polyurethane.

17. The coated label of any of claims 10–16, wherein the silica is a synthetic amorphous silica.

18. The coated label of any of claims 10–17, wherein the crosslinking agent is selected from the group consisting of a hydrophilic isocyanate, a carbodiimide, an aziridine, or a combination thereof.

19. The coated label of any of claims 10–18, wherein the polymeric substrate is selected from a polyester layer, a propylene-based layer, or a combination thereof.

20. A printed coated label comprising: (A) a polymeric substrate having a top surface and an opposing bottom surface; (B) an adhesive layer in contact with the bottom surface of the polymeric substrate; (C) a coating layer in contact with the top surface of the polymeric substrate, the coating layer formed from a coating composition comprising (i) a waterborne polyurethane dispersion; (ii) a silica; and (iii) from 0.5 wt% to 10 wt% of a crosslinking agent, based on a total weight of the coating composition; and (D) an ink layer in contact with the coating layer.

Images