Multi-layer coating system

Abstract

The present invention provides a multi-layer coating system, the multi-layer coating system comprising: an undercoat coating layer derived from a UV curable undercoat coating composition, the UV curable undercoat coating composition comprising: a1) an epoxy material; b1) a polyol material and / or a diketone functional material having a hydroxyl value (OHV) of at least 35 mg KOH / g; and c1) a photoinitiator; and an ink layer disposed directly on the base coat coating, the ink layer derived from an ink composition. The present invention extends to a multi-layer coating system for aluminum packaging, the multi-layer coating system comprising: an ink layer derived from an ink composition; and an overcoat coating layer disposed directly on the ink layer, the overcoat coating layer derived from a UV curable overcoat coating composition, the UV curable overcoat coating composition comprising: a2) an epoxy material; b2) a polyol material and / or a diketone functional material; and c2) a photoinitiator.

Description

Technical Field

[0001] The present disclosure relates to a multi-layer coating system that includes one or more coatings in direct contact with an ink layer (such as a digital printing ink layer). The coating in direct contact with the ink layer contains an epoxy resin, a polyol material, and a photoinitiator.

[0002] In particular, the present invention relates to a multi-layer coating system that includes: a primer layer derived from a UV-curable primer coating composition containing an epoxy resin, a polyol material, and a photoinitiator; an ink layer derived from an ink composition; and optionally a topcoat layer derived from a topcoat coating composition. The present disclosure also extends to a package (such as a plastic package) having the multi-layer coating system applied to at least a portion thereof; and a method of producing such a package.

[0003] The present invention also extends to a multi-layer coating system for an aluminum package that includes: optionally a primer coating derived from a primer coating composition; an ink layer derived from an ink composition; and an overcoat layer derived from a UV-curable overcoat coating composition that contains: an epoxy material; a polyol material and / or a diketone functional material, and a photoinitiator. The present disclosure also extends to an aluminum package having the multi-layer coating system applied to at least a portion thereof; and a method of producing such a package. Background Art

[0004] Various coatings are applied to the surfaces of packages (such as packages for food or beverages or for personal care products) to form protective coatings and / or decorative coatings. For example, coatings can be applied to packages formed from metals (including aluminum), or to packages formed from plastics (including polyethylene, polypropylene, and / or polyethylene terephthalate). Coating compositions can be applied to the inner surface of a package to protect the substrate (the package) from the contents (such as food, toothpaste, or personal care products) that may be contained therein. Coating compositions can also be applied to the outer surface of a metal or plastic or metal package, for example, to provide a decorative and / or protective coating.

[0005] Coating compositions can be applied to a pre-formed plastic package, such as by spraying and / or dip coating the component, and then curing. The coating should be capable of being applied to the substrate at a high speed while also providing the necessary properties to meet the needs of the end user. For example, the resulting coating should be safe for contact with the contents of the package, safe for contact with the end user, and / or have excellent adhesion to the substrate.

[0006] Typically, after forming a metal or plastic or metal package, a decorative coating can be applied. For example, an image can be printed onto the surface of the package using ink. Optionally, an overcoat can also be applied on top of the printed image. Typically, offset printing using conventional offset inks has been used in the packaging industry. However, there is a shift towards using digital printing to directly transfer an image onto a substrate (package). In any printing process, it is necessary to ensure that the resulting image has sufficient color depth and resolution, as well as good adhesion to the substrate.

[0007] Many coating compositions for food and beverage containers are based on epoxy resins based on bisphenol A polyglycidyl ethers. Bisphenol A in packaging coatings is problematic as bisphenol A itself (BPA), its derivatives such as diglycidyl ether of bisphenol A (BADGE), epoxy novolac resins, and polyols prepared from bisphenol A and bisphenol F. Although the scientific evidence available to date indicates that trace amounts of BPA or BADGE that may be released from existing coatings do not pose a risk to human health, some people still consider these compounds harmful to human health. Therefore, there is a strong desire to eliminate these compounds from coatings used for food and beverage containers. Accordingly, there is a need for a packaging coating composition for food or beverage containers that does not contain extractable amounts of BPA, BADGE, or other derivatives of BPA and still has suitable properties for this application. Summary of the Invention

[0008] According to the present disclosure, there is provided a multi-layer coating system comprising:

[0009] i) a primer coating derived from a UV-curable primer coating composition comprising:

[0010] a1) an epoxy material;

[0011] b1) a polyol material and / or diketone functional material having a hydroxyl value (OHV) of at least 35 mg KOH / g;

[0012] and

[0013] c1) a photoinitiator;

[0014] ii) an ink layer disposed directly on the primer coating, the ink layer being derived from an ink composition,

[0015] optionally wherein the ink composition is digitally printed; and

[0016] iii) optionally, a topcoat coating disposed directly on the ink layer, the topcoat coating being derived from a topcoat coating composition.

[0017] There is also provided a package having a multi - layer coating system applied to at least a portion of the package, the multi - layer coating system comprising:

[0018] i) a primer coating derived from a UV - curable primer coating composition, the UV - curable primer coating composition comprising:

[0019] a1) an epoxy material;

[0020] b1) a polyol material and / or diketone functional material having a hydroxyl value (OHV) of at least 35 mg KOH / g;

[0021] and

[0022] c1) a photoinitiator; and

[0023] ii) an ink layer directly disposed on the primer coating, the ink layer being derived from an ink composition,

[0024] optionally wherein the ink composition is digitally printed; and

[0025] iii) optionally, a topcoat coating directly disposed on the ink layer, the topcoat coating being derived from a topcoat coating composition.

[0026] There is also provided a plastic package having a multi - layer coating system applied to at least a portion of the plastic package, the multi - layer coating system comprising:

[0027] i) a primer coating derived from a UV - curable primer coating composition, the UV - curable primer coating composition comprising:

[0028] a1) an epoxy material;

[0029] b1) a polyol material and / or diketone functional material having a hydroxyl value (OHV) of at least 35 mg KOH / g;

[0030] and

[0031] c1) a photoinitiator;

[0032] ii) an ink layer directly disposed on the primer coating, the ink layer being derived from an ink composition,

[0033] optionally wherein the ink composition is digitally printed; and

[0034] iii) optionally, a topcoat coating directly disposed on the ink layer, the topcoat coating being derived from a topcoat coating composition.

[0035] There is also provided a method for producing a package, the method comprising the following steps:

[0036] I) Applying a UV-curable primer coating composition to at least a portion of the package, the UV-curable primer coating composition comprising:

[0037] a1) An epoxy material;

[0038] b1) A polyol material and / or a diketone functional material having a hydroxyl value (OHV) of at least 35 mg KOH / g;

[0039] and

[0040] c1) A photoinitiator;

[0041] II) Curing the UV-curable primer coating composition to form a cured primer coating;

[0042] III) Applying an ink composition, such as by digital printing, to at least a portion of the primer coating; and

[0043] IV) Curing the ink composition to form an ink layer;

[0044] V) Optionally applying a topcoat coating composition to at least a portion of the ink layer; and

[0045] VI) Curing the topcoat coating composition, if present, to form a cured topcoat coating.

[0046] There is also provided a method for producing a plastic package, the method comprising the following steps:

[0047] I) Applying a UV-curable primer coating composition to at least a portion of the plastic package, the UV-curable primer coating composition comprising:

[0048] a1) An epoxy material;

[0049] b1) A polyol material and / or a diketone functional material having a hydroxyl value (OHV) of at least 35 mg KOH / g;

[0050] and

[0051] c1) A photoinitiator;

[0052] II) Curing the UV-curable primer coating composition to form a cured primer coating;

[0053] III) Applying an ink composition, such as by digital printing, to at least a portion of the primer coating; and

[0054] IV) Curing the ink composition to form an ink layer;

[0055] V) Optionally, apply a topcoat coating composition onto at least a portion of the ink layer; and

[0056] VI) Cure the topcoat coating composition, if present, to form a cured topcoat layer.

[0057] There is also provided a multi-layer coating system for an aluminum package such as an aluminum one-piece spray can and / or tube, the multi-layer coating system comprising:

[0058] i) Optionally, a primer coating, the primer coating being derived from a primer coating composition;

[0059] ii) An ink layer, the ink layer being directly disposed on the aluminum package and / or the primer coating if present, the ink layer being derived from an ink composition, optionally wherein the ink composition is digitally printed; and

[0060] iii) An overcoat layer, the overcoat layer being directly disposed on the ink layer, the overcoat layer being derived from a UV-curable overcoat coating composition, the UV-curable overcoat coating composition comprising:

[0061] a2) An epoxy material;

[0062] b2) A polyol material and / or a diketone-functional material; and

[0063] c2) A photoinitiator.

[0064] There is also provided an aluminum package such as an aluminum one-piece spray can and / or tube, having a multi-layer coating system applied onto at least a portion of the aluminum package, the multi-layer coating system comprising:

[0065] i) Optionally a primer coating, the primer coating being derived from a primer coating composition;

[0066] ii) An ink layer, the ink layer being directly disposed on the aluminum package and / or the primer coating if present, the ink layer being derived from an ink composition, optionally wherein the ink composition is digitally printed; and

[0067] iii) An overcoat layer, the overcoat layer being directly disposed on the ink layer, the overcoat layer being derived from a UV-curable overcoat coating composition, the UV-curable overcoat coating composition comprising:

[0068] a2) An epoxy material;

[0069] b2) A polyol material and / or a diketone-functional material; and

[0070] c2) A photoinitiator.

[0071] There is also provided a method of producing an aluminum package such as an aluminum one-piece spray can and / or tube, the method comprising the steps of:

[0072] I) Optionally applying a primer coating composition to at least a portion of the aluminum package;

[0073] II) Curing the primer coating composition, if present, to form a cured primer coating;

[0074] III) Applying an ink composition, such as by digital printing, onto at least a portion of the aluminum package or the primer coating, if present;

[0075] IV) Curing the ink composition to form an ink layer;

[0076] V) Applying a UV-curable topcoat coating composition comprising:

[0077] a2) An epoxy material;

[0078] b2) A polyol material and / or a diketone-functional material; and

[0079] c2) A photoinitiator; and

[0080] VI) Curing the UV-curable topcoat coating composition to form a cured topcoat coating. Detailed Description

[0081] UV curable primer coating composition

[0082] The multi-layer coating system may include a primer coating derived from a UV-curable primer coating composition comprising an epoxy material, a polyol material and / or a diketone-functional material, and a photoinitiator. The terms "UV-curable primer coating composition" and "primer coating composition" may be used interchangeably herein. Unless otherwise specified, any reference to a "primer coating composition" shall be construed as the primer coating composition being UV-curable. As used herein, "UV-curable" and like terms mean that the coating composition can be cured by exposure to ultraviolet (UV) radiation, i.e., made hard to form a coating (or film).

[0083] The UV-curable primer coating composition comprises an epoxy material. The epoxy material can be any suitable epoxy material. As used herein, "epoxy material" and like terms mean a material comprising at least one side chain and / or terminal epoxy group.

[0084] The epoxy material may include aliphatic epoxy resins, alicyclic epoxy resins, and / or aromatic epoxy resins. Examples of suitable epoxy resins include, but are not limited to: epoxy-functional acrylic resins, 1,2-propanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, poly(propylene glycol) diglycidyl ether, 1,4-cyclohexanemethanol diglycidyl ether, 1,3-cyclohexanemethanol diglycidyl ether, 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylethylene oxide, 2-(3',4'-epoxycyclohexyl)-5,1”-spiro-3”,4”-epoxycyclohexane-1,3-dioxane, vinyl cyclohexene monoxide, bis(3,4-epoxycyclohexylmethyl) adipate, diglycidyl ester of cardanol, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, diglycidyl ether of bisphenol A (DGEBA), solid epoxy resin based on DGEBA, phenoxy resin, diglycidyl ether of bisphenol F, epoxy novolac resin, cresol epoxy novolac resin, and combinations thereof.

[0085] The epoxy material may include alicyclic epoxy resins.

[0086] The epoxy material may include 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 1,4-butanediol diglycidyl ether, bis(3,4-epoxycyclohexylmethyl) adipate, 1,6-hexanediol diglycidyl ether, and / or combinations thereof.

[0087] The epoxy material may include commercially available epoxy materials. Examples of suitable commercially available epoxy materials include, but are not limited to, those sold under the trade name UviCure(RTM) available from Lambson, such as UviCure S105, UviCure S105E, and UviCure S128; those sold under the trade name D.E.R.(RTM) available from Olin Epoxy, such as D.E.R.721, D.E.R.723, D.E.R.727, D.E.R.732, D.E.R.736, and D.E.R.741; those sold under the trade name Cardolite(RTM) available from Cardolite, such as Cardolite NC-547, NC-513, LITE 513E, Ultra LITE 513, NC-514, and NC-514S; and combinations thereof.

[0088] The epoxy material can be present in any suitable amount. The UV-curable primer coating composition can comprise at least 20% by weight, such as at least 30% by weight, such as at least 40% by weight, such as at least 50% by weight, such as at least 55% by weight, such as at least 60% by weight, such as at least 65% by weight, of the epoxy material based on the total solids weight of the UV-curable primer coating composition. The UV-curable primer coating composition can comprise up to 99% by weight, such as up to 95% by weight, such as up to 90% by weight, such as up to 85% by weight, such as up to 80% by weight, such as up to 75% by weight, of the epoxy material based on the total solids weight of the UV-curable primer coating composition.

[0089] The UV-curable primer coating composition can comprise from 20 to 99% by weight, such as from 30 to 99% by weight, such as from 40 to 99% by weight, such as from 50 to 99% by weight, such as from 55 to 99% by weight, such as from 60 to 99% by weight, such as from 65 to 99% by weight, of the epoxy material based on the total solids weight of the UV-curable primer coating composition. The UV-curable primer coating composition can comprise from 20 to 95% by weight, such as from 30 to 95% by weight, such as from 40 to 95% by weight, such as from 50 to 95% by weight, such as from 55 to 95% by weight, such as from 60 to 95% by weight, such as from 65 to 95% by weight, of the epoxy material based on the total solids weight of the UV-curable primer coating composition. The UV-curable primer coating composition can comprise from 20 to 90% by weight, such as from 30 to 90% by weight, such as from 40 to 90% by weight, such as from 50 to 90% by weight, such as from 55 to 90% by weight, such as from 60 to 90% by weight, such as from 65 to 90% by weight, of the epoxy material based on the total solids weight of the UV-curable primer coating composition. The UV-curable primer coating composition can comprise from 20 to 85% by weight, such as from 30 to 85% by weight, such as from 40 to 85% by weight, such as from 50 to 85% by weight, such as from 55 to 85% by weight, such as from 60 to 85% by weight, such as from 65 to 85% by weight, of the epoxy material based on the total solids weight of the UV-curable primer coating composition. The UV-curable primer coating composition can comprise from 20 to 80% by weight, such as from 30 to 80% by weight, such as from 40 to 80% by weight, such as from 50 to 80% by weight, such as from 55 to 80% by weight, such as from 60 to 80% by weight, such as from 65 to 80% by weight, of the epoxy material based on the total solids weight of the UV-curable primer coating composition. The UV-curable primer coating composition can comprise from 20 to 75% by weight, such as from 30 to 75% by weight, such as from 40 to 75% by weight, such as from 50 to 75% by weight, such as from 55 to 75% by weight, such as from 60 to 75% by weight, such as from 65 to 75% by weight, of the epoxy material based on the total solids weight of the UV-curable primer coating composition.

[0090] The UV-curable primer coating composition may comprise 50 to 90% by weight of an epoxy material based on the total solid weight of the UV-curable primer coating composition.

[0091] The UV-curable primer coating composition may comprise 55 to 85% by weight of an epoxy material based on the total solid weight of the UV-curable primer coating composition.

[0092] The UV-curable primer coating composition may comprise 60 to 80% by weight of an epoxy material based on the total solid weight of the UV-curable primer coating composition.

[0093] The UV-curable primer coating composition may comprise 65 to 75% by weight of an epoxy material based on the total solid weight of the UV-curable primer coating composition.

[0094] The UV-curable primer coating composition may comprise a polyol material having a hydroxyl value (OHV) of at least 35 mg KOH / g. The polyol material can be any suitable polyol material (provided that it has a hydroxyl value (OHV) of at least 35 mg KOH / g).

[0095] As used herein, "polyol" and similar terms refer to compounds having two or more hydroxyl groups, such as two, three, or four etc. hydroxyl groups. The hydroxyl groups of the polyol material can be linked by a bridging group selected from: an alkylene group; an alkenylene group; an alkynylene group; or an arylene group. The polyol material can be an organic polyol material.

[0096] Examples of suitable polyol materials include, but are not limited to, polyethylene glycol, polypropylene glycol, polycaprolactone, hydroxyl-functional polymers such as hydroxyl-functional polyester resins, acrylic resins, polyether resins, alkyd resins, vinyl resins, polyurethane resins and / or polysiloxane resins; hydroxyl-functional dendritic polymers such as fatty acid-modified dendritic polymers having two or more, such as 2, 3, 4, 5, 6 or more terminal hydroxyl groups; alkoxylated ether polyols; and / or combinations thereof.

[0097] The polyol material may include a hydroxyl-functional polyester resin.

[0098] The polyol material may include polycaprolactone.

[0099] The polyol material may include polypropylene glycol.

[0100] The polyol material may include fatty acid-modified dendritic polymers having two or more terminal hydroxyl groups, such as 2 to 6 terminal hydroxyl groups, such as 4 to 6 terminal hydroxyl groups, such as 6 terminal hydroxyl groups.

[0101] The polyol material may include a hydroxyl-functional vinyl resin.

[0102] The polyol material may include commercially available polyol materials. Examples of suitable commercially available polyol materials include, but are not limited to, those sold under the trade name Desmophen(RTM) and commercially available from Covestro, such as Desmophen 1380, Desmophen 1652, Desmophen C1200, Desmophen 1700, Desmophen 850, Desmophen 1800, and Desmophen 670; those sold under the trade name Capa(RTM) and commercially available from Perstorp, such as Capa 3031, Capa 4104, Capa 2043, Capa 3091, Capa 2065, Capa 2205, and Capa 2054; those sold under the trade name K-flex(RTM) and commercially available from King Industries, such as K-flex 337BA; those sold under the trade name Boltorn(RTM) and commercially available from Perstorp, such as Bolthorn H2004, Boltorn 4311, Boltorn P1000, and Boltorn P500; polyol 4290 commercially available from Perstorp; those sold under the trade name Nebores(RTM) and commercially available from Safic-Alcan, such as Nebores VAGH; and combinations thereof.

[0103] The polyol material may include commercially available hydroxyl-functional polyester resins. Suitable commercially available hydroxyl-functional polyester resins include, but are not limited to, those sold under the trade name Tego(RTM) and commercially available from Evonik, such as Tego Addbond LP 1600, LP1611, LTW, LTW-B, LTH, 2440, and 2325; those sold under the trade name URALAC(RTM) and commercially available from DSM, such as URALAC P1580; and combinations thereof.

[0104] The polyol material may have an OHV of at least 40 mg KOH / g, such as at least 45 mg KOH / g, such as at least 50 mg KOH / g, such as at least 55 mg KOH / g, such as at least 60 mg KOH / g, such as at least 70 KOH / g, such as at least 80 KOH / g, such as at least 90 KOH / g, such as at least 100 mg KOH / g, such as at least 110 mg KOH / g, such as at least 120 mg KOH / g, such as at least 130 mg KOH / g, such as at least 140 mg KOH / g, such as at least 150 mg KOH / g, such as at least 200 mg KOH / g, such as at least 250 mg KOH / g. The polyol material may have an OHV of up to 650 mg KOH / g, such as up to 600 mg KOH / g, such as up to 550 mg KOH / g, such as up to 500 mg KOH / g, such as up to 450 mg KOH / g, such as up to 400 mg KOH / g.

[0105] The polyol material may have an OHV of 35 to 650 mg KOH / g, such as 40 to 650 mg KOH / g, such as 45 to 650 mg KOH / g, such as 50 to 650 mg KOH / g, such as 55 to 650 mg KOH / g, such as 60 to 650 mg KOH / g, such as 70 to 650 KOH / g, such as 80 to 650 KOH / g, such as 90 to 650 KOH / g, such as 100 to 650 mg KOH / g, such as 110 to 650 KOH / g, such as 120 to 650 KOH / g, such as 130 to 650 KOH / g, such as 140 to 650 KOH / g, such as 150 to 650 mg KOH / g, such as 200 to 650 mg KOH / g, such as 250 to 650 mg KOH / g. The polyol material may have an OHV of 35 to 600 mg KOH / g, such as 40 to 600 mg KOH / g, such as 45 to 600 mg KOH / g, such as 50 to 600 mg KOH / g, such as 55 to 600 mg KOH / g, such as 60 to 600 mg KOH / g, such as 70 to 600 KOH / g, such as 80 to 600 KOH / g, such as 90 to 600 KOH / g, such as 100 to 600 mg KOH / g, such as 110 to 600 KOH / g, such as 120 to 600 KOH / g, such as 130 to 600 KOH / g, such as 140 to 600 KOH / g, such as 150 to 600 mg KOH / g, such as 200 to 600 mg KOH / g, such as 250 to 600 mg KOH / g. The polyol material may have an OHV of 35 to 550 mg KOH / g, such as 40 to 550 mg KOH / g, such as 45 to 550 mg KOH / g, such as 50 to 550 mg KOH / g, such as 55 to 550 mg KOH / g, such as 60 to 550 mg KOH / g, such as 70 to 550 KOH / g, such as 80 to 550 KOH / g, such as 90 to 550 KOH / g, such as 100 to 550 mg KOH / g, such as 110 to 550 KOH / g, such as 120 to 550 KOH / g, such as 130 to 550 KOH / g, such as 140 to 550 KOH / g, such as 150 to 550 mg KOH / g, such as 200 to 550 mg KOH / g, such as 250 to 550 mg KOH / g.The polyol material may have an OHV of 35 to 500 mg KOH / g, such as 40 to 500 mg KOH / g, such as 45 to 500 mg KOH / g, such as 50 to 500 mg KOH / g, such as 55 to 500 mg KOH / g, such as 60 to 500 mg KOH / g, such as 70 to 500 KOH / g, such as 80 to 500 KOH / g, such as 90 to 500 KOH / g, such as 100 to 500 mg KOH / g, such as 110 to 500 KOH / g, such as 120 to 500 KOH / g, such as 130 to 500 KOH / g, such as 140 to 500 KOH / g, such as 150 to 500 mg KOH / g, such as 200 to 500 mg KOH / g, such as 250 to 500 mg KOH / g. The polyol material may have an OHV of 35 to 450 mg KOH / g, such as 40 to 450 mg KOH / g, such as 45 to 450 mg KOH / g, such as 50 to 450 mg KOH / g, such as 55 to 450 mg KOH / g, such as 60 to 450 mgKOH / g, such as 70 to 450 KOH / g, such as 80 to 450 KOH / g, such as 90 to 450 KOH / g, such as 100 to 450 mg KOH / g, such as 110 to 450 KOH / g, such as 120 to 450 KOH / g, such as 130 to 450 KOH / g, such as 140 to 450 KOH / g, such as 150 to 450 mg KOH / g, such as 200 to 450 mg KOH / g, such as 250 to 450 mg KOH / g. The polyol material may have an OHV of 35 to 400 mg KOH / g, such as 40 to 400 mg KOH / g, such as 45 to 400 mg KOH / g, such as 50 to 400 mgKOH / g, such as 55 to 400 mg KOH / g, such as 60 to 400 mg KOH / g, such as 70 to 400 KOH / g, such as 80 to 400 KOH / g, such as 90 to 400 KOH / g, such as 100 to 400 mg KOH / g, such as 110 to 400 KOH / g, such as 120 to 400 KOH / g, such as 130 to 400 KOH / g, such as 140 to 400 KOH / g, such as 150 to 400 mg KOH / g, such as 200 to 400 mg KOH / g, such as 250 to 400 mg KOH / g.

[0106] The polyol material may have a hydroxyl value of at least 50 mg KOH / g.

[0107] The polyol material may have a hydroxyl value of at least 100 mg KOH / g.

[0108] As reported herein, the total hydroxyl value is expressed as a solid.

[0109] As reported herein, the hydroxyl value expressed as a solid is the number of milligrams of KOH equivalent to the hydroxyl groups in 1 g of the material. In such a method, a sample (typically 0.1 to 3 g) is accurately weighed into a conical flask and dissolved in 20 ml of tetrahydrofuran with appropriate use of light heating and stirring. Then 10 ml of 0.1 M 4-(dimethylamino)pyridine in tetrahydrofuran (catalyst solution) and 5 ml of 9 vol% acetic anhydride solution in tetrahydrofuran (i.e., 90 ml acetic anhydride in 910 ml tetrahydrofuran; acetylation solution) are added to the mixture. After 5 minutes, 10 ml of 80 vol% tetrahydrofuran solution (i.e., 4 parts by volume of tetrahydrofuran and 1 part of distilled water; hydrolysis solution) is added. After 15 minutes, 10 ml of tetrahydrofuran is added and the solution is titrated with 0.5 M ethanolic potassium hydroxide (KOH). A blank sample in which the solid polyester sample is omitted is also run. The resulting hydroxyl value is expressed in mg KOH / g and is calculated using the following equation:

[0110] Hydroxyl value = ((V2 – V1) x molar concentration (M) of KOH solution x 56.1) / weight of solid sample (g)

[0111] where V1 is the titre of the KOH solution (ml) for the polyester sample and V2 is the titre of the KOH solution (ml) for the blank sample. All values of the hydroxyl value reported herein are measured in this way.

[0112] The polyol material can have any suitable acid value (AV; also known as acid number or AN). The polyol material can have an acid value of up to 20 mg KOH / g, such as up to 10 mg KOH / g, such as up to 5 mg KOH / g, such as up to 4 mg KOH / g, such as up to 3 mg KOH / g, such as up to 2 mg KOH / g, such as up to 1 mg KOH / g.

[0113] As reported herein, the acid value is expressed as a solid.

[0114] As reported herein, the acid value (AV) expressed as a solid is determined by titration with 0.1 M methanolic potassium hydroxide (KOH) solution. A sample of the solid polymer (0.1 to 3 g, depending on the acid value) is accurately weighed into a conical flask and dissolved in 25 ml of dimethylformamide containing a phenolphthalein indicator with appropriate use of light heating and stirring. Then the solution is cooled to room temperature and titrated with 0.1 M methanolic potassium hydroxide solution. The resulting acid value is expressed in mg KOH / g and is calculated using the following equation:

[0115]

[0116] All values of acid number reported herein are measured in this way.

[0117] The polyol material may have any suitable number-average molecular weight (Mn). The polyol material may have an Mn of at least 100 Daltons (Da = g / mol), such as at least 200 Da, such as at least 250 Da, such as at least 300 Da. The polyol material may have an Mn of up to 50,000 Da, such as up to 25,000 Da, such as up to 20,000 Da, such as up to 10,000 Da, such as up to 5,000 Da, such as up to 4,500 Da, such as up to 4,000 Da, such as up to 3,500 Da.

[0118] The polyol material may have an Mn of 100 to 50,000 Da, such as 200 to 50,000 Da, such as 250 to 50,000 Da, such as 300 to 50,000 Da. The polyol material may have an Mn of 100 to 25,000 Da, such as 200 to 25,000 Da, such as 250 to 25,000 Da, such as 300 to 25,000 Da. The polyol material may have an Mn of 100 to 20,000 Da, such as 200 to 20,000 Da, such as 250 to 20,000 Da, such as 300 to 20,000 Da. The polyol material may have an Mn of 100 to 10,000 Da, such as 200 to 10,000 Da, such as 250 to 10,000 Da, such as 300 to 10,000 Da. The polyol material may have an Mn of 100 to 5,000 Da, such as 200 to 5,000 Da, such as 250 to 5,000 Da, such as 300 to 5,000 Da. The polyol material may have an Mn of 100 to 4,500 Da, such as 200 to 4,500 Da, such as 250 to 4,500 Da, such as 300 to 4,500 Da. The polyol material may have an Mn of 100 to 4,000 Da, such as 200 to 4,000 Da, such as 250 to 4,000 Da, such as 300 to 4,000 Da. The polyol material may have an Mn of 100 to 3,500 Da, such as 200 to 3,500 Da, such as 250 to 3,500 Da, such as 300 to 3,500 Da. The polyol material may have an Mn of 100 to 3,000 Da, such as 200 to 3,000 Da, such as 250 to 3,000 Da, such as 300 to 3,000 Da.

[0119] The polyol material may have a number-average molecular weight (Mn) of up to 5,000 Da.

[0120] The polyol material may have a number average molecular weight (Mn) of up to 4,000 Da.

[0121] The polyol material may have a number average molecular weight (Mn) of up to 3,500 Da.

[0122] The polyol material may have any suitable weight average molecular weight (Mw).

[0123] The polyol material may be a low molecular weight polyol material. As used herein, the terms “low molecular weight” and similar terms with respect to polyol materials mean polyol materials having an Mn of up to 5,000 Da.

[0124] As reported herein, Mn can be determined by using ASTM D6579-11 (“Standard Practice for Determination of Average Molecular Weight and Molecular Weight Distribution of Hydrocarbon Resins, Rosin Resins, and Terpene Resins by Size Exclusion Chromatography.” UV detector; 254 nm, solvent: unstable THF, retention time marker: toluene, sample concentration: 2 mg / ml). All values of Mn reported herein are measured in this manner.

[0125] The polyol material may have any suitable weight average molecular weight (Mw). The polyol material may have an Mw of at least 100 daltons (Da = g / mol), such as at least 200 Da, such as at least 250 Da, such as at least 300 Da. The polyol material may have an Mw of up to 50,000 Da, such as up to 25,000 Da, such as up to 20,000 Da, such as up to 10,000 Da, such as up to 5,000 Da, such as up to 4,500 Da, such as up to 4,000 Da, such as up to 3,500 Da.

[0126] The polyol material may have an Mw of 100 to 50,000 Da, such as 200 to 50,000 Da, such as 250 to 50,000 Da, such as 300 to 50,000 Da. The polyol material may have an Mw of 100 to 25,000 Da, such as 200 to 25,000 Da, such as 250 to 25,000 Da, such as 300 to 25,000 Da. The polyol material may have an Mw of 100 to 20,000 Da, such as 200 to 20,000 Da, such as 250 to 20,000 Da, such as 300 to 20,000 Da. The polyol material may have an Mw of 100 to 10,000 Da, such as 200 to 10,000 Da, such as 250 to 10,000 Da, such as 300 to 10,000 Da. The polyol material may have an Mw of 100 to 5,000 Da, such as 200 to 5,000 Da, such as 250 to 5,000 Da, such as 300 to 5,000 Da. The polyol material may have an Mw of 100 to 4,500 Da, such as 200 to 4,500 Da, such as 250 to 4,500 Da, such as 300 to 4,500 Da. The polyol material may have an Mw of 100 to 4,000 Da, such as 200 to 4,000 Da, such as 250 to 4,000 Da, such as 300 to 4,000 Da. The polyol material may have an Mw of 100 to 3,500 Da, such as 200 to 3,500 Da, such as 250 to 3,500 Da, such as 300 to 3,500 Da. The polyol material may have an Mw of 100 to 3,000 Da, such as 200 to 3,000 Da, such as 250 to 3,000 Da, such as 300 to 3,000 Da.

[0127] The polyol material may have a number average molecular weight (Mw) of up to 5,000 Da.

[0128] The polyol material may have a number average molecular weight (Mw) of up to 4,000 Da.

[0129] The polyol material may have a number average molecular weight (Mw) of up to 3,500 Da.

[0130] The polyol material may have any suitable weight average molecular weight (Mw).

[0131] Those skilled in the art will understand that the techniques for measuring the number average molecular weight can also be applied to measuring the weight average molecular weight.

[0132] The UV curable bottom coat coating composition may comprise a diketone functional material. The diketone functional material may be any suitable diketone functional material.

[0133] As used herein, "diketone-functional" and like terms refer to compounds having a -(O) m -C(O)-(CH2) n -C(O)-R group, where m is 0 or 1; n is from 1 to 20, such as from 1 to 10, such as from 1 to 8, such as from 1 to 6, such as from 1 to 4, such as from 1 to 3, such as 1 or 2, such as 1; and R is hydrogen or an alkyl, alkenyl, alkynyl, or aryl group.

[0134] m can be 1 such that the diketone functional group has the formula -O-C(O)-(CH2) n -C(O)-R, where each of n and R is as defined above.

[0135] m can be 1, n can be 1 and R can be methyl such that the diketone functional group has the formula -O-C(O)-CH2-C(O)-CH3. Thus, the diketone functional group can be an acetoacetate group.

[0136] Diketone-functional materials can include acetoacetate-functional materials.

[0137] Diketone-functional materials can include commercially available diketone-functional materials. Examples of suitable commercially available diketone-functional materials include, but are not limited to, those sold under the trade name K-flex(RTM) available from King Industries, such as K-flex 7301 and K-flex XM B301.

[0138] Diketone-functional materials can have any suitable diketone equivalent weight. Diketone-functional materials can have a diketone equivalent weight of at least 50 g / eq, such as at least 60 g / eq, such as at least 70 g / eq, such as at least 80 g / eq, such as at least 90 g / eq, such as at least 100 g / eq, such as at least 110 g / eq, such as at least 120 g / eq, such as at least 130 g / eq, such as at least 140 g / eq, such as at least 150 g / eq, such as at least 160 g / eq, such as at least 170 g / eq, such as at least 180 g / eq, such as at least 190 g / eq.

[0139] Diketone-functional materials can have a diketone equivalent weight of at least 120 g / eq.

[0140] Diketone-functional materials can have a diketone equivalent weight of at least 180 g / eq.

[0141] When the diketone functional material includes an acetoacetate functional material, the acetoacetate functional material can have any suitable acetoacetate (AcAc) equivalent weight. The acetoacetate functional material can have an AcAc equivalent weight of at least 50 g / eq, such as at least 60 g / eq, such as at least 70 g / eq, such as at least 80 g / eq, such as at least 90 g / eq, such as at least 100 g / eq, such as at least 110 g / eq, such as at least 120 g / eq, such as at least 130 g / eq, such as at least 140 g / eq, such as at least 150 g / eq, such as at least 160 g / eq, such as at least 170 g / eq, such as at least 180 g / eq, such as at least 190 g / eq.

[0142] The acetoacetate functional material can have an AcAc equivalent weight of at least 120 g / eq.

[0143] The acetoacetate functional material can have an AcAc equivalent weight of at least 180 g / eq.

[0144] When the UV-curable primer coating composition contains a polyol material, the UV-curable primer coating composition can contain at least 2% by weight of the polyol material based on the total solid weight of the UV-curable primer coating composition. The UV-curable primer coating composition can contain at least 3% by weight, such as at least 4% by weight, such as at least 5% by weight of the polyol material based on the total solid weight of the UV-curable primer coating composition. The UV-curable primer coating composition can contain up to 80% by weight, such as up to 70% by weight, such as up to 60% by weight, such as up to 50% by weight, such as up to 40% by weight, such as up to 30% by weight, such as up to 20% by weight, such as up to 15% by weight of the polyol material based on the total solid weight of the UV-curable primer coating composition.

[0145] The UV-curable primer coating composition may comprise from 2 to 80% by weight, such as from 2 to 70% by weight, such as from 2 to 60% by weight, such as from 2 to 50% by weight, such as from 2 to 40% by weight, such as from 2 to 30% by weight, such as from 2 to 20% by weight, such as from 2 to 15% by weight, of a polyol material based on the total solids weight of the UV-curable primer coating composition. The UV-curable primer coating composition may comprise from 3 to 80% by weight, such as from 3 to 70% by weight, such as from 3 to 60% by weight, such as from 3 to 50% by weight, such as from 3 to 40% by weight, such as from 3 to 30% by weight, such as from 3 to 20% by weight, such as from 3 to 15% by weight, of a polyol material based on the total solids weight of the UV-curable primer coating composition. The UV-curable primer coating composition may comprise from 4 to 80% by weight, such as from 4 to 70% by weight, such as from 4 to 60% by weight, such as from 4 to 50% by weight, such as from 4 to 40% by weight, such as from 4 to 30% by weight, such as from 4 to 20% by weight, such as from 4 to 15% by weight, of a polyol material based on the total solids weight of the UV-curable primer coating composition. The UV-curable primer coating composition may comprise from 5 to 80% by weight, such as from 5 to 70% by weight, such as from 5 to 60% by weight, such as from 5 to 50% by weight, such as from 5 to 40% by weight, such as from 5 to 30% by weight, such as from 5 to 20% by weight, such as from 5 to 15% by weight, of a polyol material based on the total solids weight of the UV-curable primer coating composition.

[0146] The UV-curable primer coating composition may comprise at least 5% by weight of a polyol material based on the total solids weight of the UV-curable primer coating composition.

[0147] The UV-curable primer coating composition may comprise from 5 to 30% by weight of a polyol material based on the total solids weight of the UV-curable primer coating composition.

[0148] The UV-curable primer coating composition may comprise from 5 to 20% by weight of a polyol material based on the total solids weight of the UV-curable primer coating composition.

[0149] The UV-curable primer coating composition may comprise from 5 to 15% by weight of a polyol material based on the total solids weight of the UV-curable primer coating composition.

[0150] When the UV - curable primer coating composition contains a diketone - functional material, the UV - curable primer coating composition may contain at least 2% by weight of the diketone - functional material based on the total solids weight of the UV - curable primer coating composition. The UV - curable primer coating composition may contain at least 3% by weight, such as at least 4% by weight, such as at least 5% by weight of the diketone - functional material based on the total solids weight of the UV - curable primer coating composition. The UV - curable primer coating composition may contain up to 80% by weight, such as up to 70% by weight, such as up to 60% by weight, such as up to 50% by weight, such as up to 40% by weight, such as up to 30% by weight, such as up to 20% by weight, such as up to 15% by weight of the diketone - functional material based on the total solids weight of the UV - curable primer coating composition.

[0151] The UV - curable primer coating composition may contain 2 to 80% by weight, such as 2 to 70% by weight, such as 2 to 60% by weight, such as 2 to 50% by weight, such as 2 to 40% by weight, such as 2 to 30% by weight, such as 2 to 20% by weight, such as 2 to 15% by weight of the diketone - functional material based on the total solids weight of the UV - curable primer coating composition. The UV - curable primer coating composition may contain 3 to 80% by weight, such as 3 to 70% by weight, such as 3 to 60% by weight, such as 3 to 50% by weight, such as 3 to 40% by weight, such as 3 to 30% by weight, such as 3 to 20% by weight, such as 3 to 15% by weight of the diketone - functional material based on the total solids weight of the UV - curable primer coating composition. The UV - curable primer coating composition may contain 4 to 80% by weight, such as 4 to 70% by weight, such as 4 to 60% by weight, such as 4 to 50% by weight, such as 4 to 40% by weight, such as 4 to 30% by weight, such as 4 to 20% by weight, such as 4 to 15% by weight of the diketone - functional material based on the total solids weight of the UV - curable primer coating composition. The UV - curable primer coating composition may contain 5 to 80% by weight, such as 5 to 70% by weight, such as 5 to 60% by weight, such as 5 to 50% by weight, such as 5 to 40% by weight, such as 5 to 30% by weight, such as 5 to 20% by weight, such as 5 to 15% by weight of the diketone - functional material based on the total solids weight of the UV - curable primer coating composition.

[0152] The UV - curable primer coating composition may contain at least 5% by weight of the diketone - functional material based on the total solids weight of the UV - curable primer coating composition.

[0153] The UV - curable primer coating composition may contain 5 to 30% by weight of the diketone - functional material based on the total solids weight of the UV - curable primer coating composition.

[0154] The UV-curable primer coating composition can comprise from 5 to 20% by weight of a diketone functional material based on the total solids weight of the UV-curable primer coating composition.

[0155] The UV-curable primer coating composition can comprise from 5 to 15% by weight of a diketone functional material based on the total solids weight of the UV-curable primer coating composition.

[0156] The UV-curable primer coating composition comprises a photoinitiator. As used herein, "photoinitiator" and like terms mean a molecule that generates reactive species (such as cations) when exposed to radiation (such as UV). The reactive species can initiate a polymerization process to cure the composition.

[0157] The photoinitiator can be formed from any suitable photoinitiator. The photoinitiator can include cationic photoinitiators. Examples of suitable photoinitiators include, but are not limited to, sulfonium salts such as triphenylsulfonium salts and sulfonium hexafluoroantimonate; diazonium salts; iodonium salts such as diaryliodonium salts; ferrocenium salts; other metallocene compounds; isobutyl benzoin ether; a mixture of butyl isomers of butyl benzoin ether; α,α -diethoxyacetophenone; α,α -dimethoxy-α -phenylacetophenone; ethyl benzoin ether; isopropyl benzoin ether; butyl benzoin ether; isobutyl benzoin ether; α,α -diethoxy-α -phenylacetophenone; 4,4'-dicarboethoxybenzoin ethyl ether; benzoin phenyl ether; α -methylbenzoin ethyl ether; α -hydroxymethylbenzoin methyl ether; α,α,α -trichloroacetophenone; and combinations thereof.

[0158] The photoinitiator can include cationic photoinitiators.

[0159] The photoinitiator can include sulfonium salts such as sulfonium hexafluoroantimonate.

[0160] The photoinitiator can have any suitable absorption maximum. The photoinitiator can have an absorption maximum at 291 and / or 279 nm (such as at 291 and 279 nm).

[0161] The photoinitiator can be present in the UV-curable primer coating composition in any suitable amount. The UV-curable primer coating composition can comprise at least 0.1% by weight, such as at least 0.5% by weight, such as at least 1% by weight of the photoinitiator based on the total solids weight of the UV-curable primer coating composition. The UV-curable primer coating composition can comprise up to 20% by weight, such as up to 15% by weight, such as up to 10% by weight, such as up to 5% by weight, such as up to 4% by weight, such as up to 3% by weight, such as up to 2% by weight of the photoinitiator based on the total solids weight of the UV-curable primer coating composition.

[0162] The UV-curable primer coating composition may contain 0.1 to 20% by weight, such as 0.1 to 15% by weight, such as 0.1 to 10% by weight, such as 0.1 to 5% by weight, such as 0.1 to 4% by weight, such as 0.1 to 3% by weight, such as 0.1 to 2% by weight of a photoinitiator based on the total solid weight of the UV-curable primer coating composition. The UV-curable primer coating composition may contain 0.5 to 20% by weight, such as 0.5 to 15% by weight, such as 0.5 to 10% by weight, such as 0.5 to 5% by weight, such as 0.5 to 4% by weight, such as 0.5 to 3% by weight, such as 0.5 to 2% by weight of a photoinitiator based on the total solid weight of the UV-curable primer coating composition. The UV-curable primer coating composition may contain 1 to 20% by weight, such as 1 to 15% by weight, such as 1 to 10% by weight, such as 1 to 5% by weight, such as 1 to 4% by weight, such as 1 to 3% by weight, such as 1 to 2% by weight of a photoinitiator based on the total solid weight of the UV-curable primer coating composition.

[0163] The UV-curable primer coating composition may contain 1 to 5% by weight of a photoinitiator based on the total solid weight of the UV-curable primer coating composition.

[0164] The UV-curable primer coating composition may contain 1 to 2% by weight of a photoinitiator based on the total solid weight of the UV-curable primer coating composition.

[0165] The UV-curable primer coating composition may further contain a polyester material.

[0166] The polyester material may have a hydroxyl value (OHV) of less than 35 mg KOH / g, such as up to 30 mg KOH / g. The polyester material may have an OHV of at least 0 mg KOH / g, such as at least 5 mg KOH / g, such as at least 10 mg KOH / g, such as at least 15 mg KOH / g, such as at least 20 mg KOH / g.

[0167] The polyester material may have an OHV of 0 to less than 35 mg KOH / g, such as 5 to less than 35 mg KOH / g, such as 10 to less than 35 mg KOH / g, such as 15 to less than 35 mg KOH / g, such as 20 to less than 35 mg KOH / g. The polyester material may have an OHV of 0 to 30 mg KOH / g, such as 5 to 30 mg KOH / g, such as 10 to 30 mg KOH / g, such as 15 to 30 mg KOH / g, such as 20 to 30 mg KOH / g.

[0168] The polyester material may have an OHV of up to 30 mg KOH / g.

[0169] The polyester material may have an OHV of 20 to 30 mg KOH / g.

[0170] For the avoidance of doubt, the UV curable basecoat coating composition may include a polyol material comprising a hydroxyl functional polyester resin and an additional polyester material. It will be appreciated by those skilled in the art that a polyester resin having an OHV of at least 35 mg KOH / g should be interpreted as a polyol material. In contrast, a polyester resin having an OHV of less than 35 mg KOH / g, such as up to 30 mg KOH / g, should be interpreted as an additional polyester material.

[0171] The polyester material may include the reaction product of a polyacid and a polyol.

[0172] As used herein, "polyacid" and like terms refer to compounds having two or more carboxylic acid groups, such as two, three or four acid groups, and include esters (wherein one or more acid groups are esterified) or anhydrides of the polyacid. A polyacid is an organic polyacid.

[0173] The carboxylic acid groups of the polyacid may be linked by a bridging group selected from: an alkylene group; an alkenylene group; an alkynylene group; or an arylene group.

[0174] The polyester material may be formed from any suitable polyacid. Suitable examples of polyacids include, but are not limited to, maleic acid; fumaric acid; itaconic acid; adipic acid; azelaic acid; succinic acid; sebacic acid; glutaric acid; sebacic acid; dodecanedioic acid; phthalic acid; isophthalic acid; 5-tert-butylisophthalic acid; tetrachlorophthalic acid; tetrahydrophthalic acid; trimellitic acid; naphthalene dicarboxylic acid; naphthalene tetracarboxylic acid; terephthalic acid; hexahydrophthalic acid; methyl hexahydrophthalic acid; dimethyl terephthalate; cyclohexane dicarboxylic acid; chlorendic anhydride; 1,3-cyclohexane dicarboxylic acid; 1,4-cyclohexane dicarboxylic acid; tricyclodecane polycarboxylic acid; endomethylene tetrahydrophthalic acid; endethylene hexahydrophthalic acid; cyclohexane tetracarboxylic acid; cyclobutane tetracarboxylic acid; esters and anhydrides of all the above acids and combinations thereof.

[0175] As used herein, "polyol" and similar terms refer to compounds having two or more hydroxyl groups, such as two, three or four hydroxyl groups. The hydroxyl groups of the polyol can be connected by a bridging group selected from: an alkylene group; an alkenylene group; an alkynylene group; or an arylene group. The polyol can be an organic polyol.

[0176] The polyester material can be formed from any suitable polyol. Suitable examples of polyols include, but are not limited to, alkylene diols such as ethylene glycol; propylene glycol; diethylene glycol; dipropylene glycol; triethylene glycol; tripropylene glycol; hexanediol; polyethylene glycol; polypropylene glycol and neopentyl glycol; hydrogenated bisphenol A; cyclohexanediol; propylene glycols including 1,2 - propylene glycol; 1,3 - propylene glycol; butylethylpropylene glycol; 2 - methyl - 1,3 - propylene glycol; and 2 - ethyl - 2 - butyl - 1,3 - propylene glycol; butanediols including 1,4 - butanediol; 1,3 - butanediol; and 2 - ethyl - 1,4 - butanediol; pentanediols including trimethylpentanediol and 2 - methylpentanediol; cyclohexanedimethanol; hexanediols including 1,6 - hexanediol; caprolactone diol (e.g., the reaction product of ε - caprolactone and ethylene glycol); hydroxyalkylated bisphenols; polyether diols such as poly(oxytetramethylene) glycol; trimethylolpropane; pentaerythritol; dipentaerythritol; trimethylolethane; trimethylolbutane; dimethylolcyclohexane; glycerol, etc. or combinations thereof.

[0177] The polyester material can include a polymer or copolymer formed from a diol and a diacid; polyol or polyacid components can optionally be used to produce a branched polymer.

[0178] The polyester material can be formed from diacids. Suitable examples of diacids include, but are not limited to, phthalic acid; isophthalic acid; terephthalic acid; 1,4 - cyclohexanedicarboxylic acid; succinic acid; adipic acid; azelaic acid; sebacic acid; fumaric acid; 2,6 - naphthalenedicarboxylic acid; phthalic acid; phthalic anhydride; tetrahydrophthalic anhydride; maleic anhydride; succinic anhydride; itaconic anhydride; diester materials such as dimethyl ester derivatives, e.g., dimethyl isophthalate, dimethyl terephthalate, dimethyl 1,4 - cyclohexanedicarboxylate, dimethyl 2,6 - naphthalenedicarboxylate, dimethyl fumarate, dimethyl phthalate, dimethyl succinate, dimethyl glutarate, dimethyl adipate; esters and acid anhydrides of all the above acids; and mixtures thereof.

[0179] The polyester material can be formed from diols. The polyester material can be formed from any suitable diols. Suitable examples of diols include, but are not limited to, ethylene glycol; 1,2-propanediol; 1,3-propanediol; 1,2-butanediol; 1,3-butanediol; 1,4-butanediol; 2-butene 1,4-diol; 2,3-butanediol; 2-methyl 1,3-propanediol; 2,2'-dimethyl 1,3-propanediol (neopentyl glycol); 1,5-pentanediol; 3-methyl 1,5-pentanediol; 2,4-diethyl 1,5-pentanediol; 1,6-hexanediol; 2-ethyl 1,3-hexanediol; diethylene glycol; triethylene glycol; dipropylene glycol; tripropylene glycol; 2,2,4-trimethylpentane 1,3-diol; 1,4-cyclohexanedimethanol; tricyclodecane dimethanol; 2,2,4,4-tetramethylcyclobutane 1,3-diol; isosorbide; 1,4-cyclohexanediol; 1,1'-isopropylidene-bis(4-cyclohexanol); and mixtures thereof.

[0180] Suitable additional polyacids that can optionally be used to produce branched polymers include, but are not limited to, the following: trimellitic anhydride; trimellitic acid; pyromellitic acid; esters and acid anhydrides of all of the above acids; and mixtures thereof.

[0181] Suitable additional polyols that can optionally be used to produce branched polymers include, but are not limited to, the following: glycerol; trimethylolpropane; trimethylolethane; 1,2,6-hexanetriol; pentaerythritol; erythritol; ditrimethylolpropane; dipentaerythritol; N,N,N',N'-tetrakis(hydroxyethyl)hexanediamide; N,N,N',N'-tetrakis(hydroxypropyl)hexanediamide; others, mainly hydroxy-functional branched monomers; or mixtures thereof.

[0182] The polyester material can be formed from any suitable molar ratio of polyacid:polyol. The molar ratio of polyacid:polyol in the polyester material can be from 10:1 to 1:10, such as from 5:1 to 1:5, such as from 3:1 to 1:3, or even from 2:1 to 1:2. The molar ratio of polyacid:polyol in the polyester material can be from 1.5:1 to 1:1.5, such as from 1.2:1 to 1:1.2.

[0183] The polyester material can be formed from any suitable molar ratio of diacid:diol. The molar ratio of diacid:diol in the polyester material can be from 10:1 to 1:10, such as from 5:1 to 1:5, such as from 3:1 to 1:3, or even from 2:1 to 1:2. The molar ratio of diacid:diol in the polyester material can be from 1.5:1 to 1:1.5, such as from 1.2:1 to 1:1.2, or even from 1.1:1 to 1:1.1.

[0184] The polyester material can optionally be formed from any suitable molar ratio of diacid + diol with polyacid and / or polyol. The polyester material can contain a molar ratio of diacid + diol with polyacid and / or polyol of from 100:1 to 1:1, such as from 100:1 to 5:1, such as from 100:1 to 20:1, or even from 100:1 to 50:1.

[0185] The polyester material can optionally be formed from additional monomers. The polyester material can optionally include additional monomers selected from monocarboxylic acids or monohydric alcohols or combinations thereof. The optional additional monomers can be organic.

[0186] The polyester material can optionally be formed from additional monocarboxylic acids. As used herein, "monocarboxylic acid" and like terms refer to compounds having one carboxylic acid group and include esters of monocarboxylic acids (where the acid group is esterified) or acid anhydrides. The monocarboxylic acid can be an organic monocarboxylic acid.

[0187] The polyester material can optionally be formed from any suitable additional monocarboxylic acids. Suitable examples of monocarboxylic acids include, but are not limited to, cyclohexanecarboxylic acid; tricyclodecane carboxylic acid; camphoric acid; benzoic acid; tert-butylbenzoic acid; C1-C 18 aliphatic carboxylic acids such as acetic acid; propionic acid; butyric acid; hexanoic acid; oleic acid; linoleic acid; undecanoic acid; lauric acid; isononanoic acid; fatty acids; hydrogenated fatty acids of naturally occurring oils; esters and / or acid anhydrides of any of the above acids and combinations thereof.

[0188] The polyester material can optionally be formed from additional monohydric alcohols. As used herein, "monohydric alcohol" and like terms refer to compounds having one hydroxyl group. The monohydric alcohol can be an organic monohydric alcohol.

[0189] The polyester material can optionally be formed from any suitable additional monohydric alcohols. Suitable examples of monohydric alcohols include, but are not limited to, benzyl alcohol; hydroxyethoxybenzene; methanol; ethanol; propanol; butanol; pentanol; hexanol; heptanol; dodecanol; stearyl alcohol; oleyl alcohol; undecanol; cyclohexanol; phenol; phenylmethanol; methylphenylmethanol; cresol; monoethers of diols; halogen-substituted or otherwise substituted alcohols and combinations thereof.

[0190] The polyester material can be prepared in the presence of an esterification catalyst. The esterification catalyst can be selected to promote the esterification reaction and / or transesterification reaction of the components. Suitable examples of esterification catalysts for preparing the polyester material include, but are not limited to, metal compounds such as stannous octanoate; stannous chloride; butyltin acid (hydroxybutyltin oxide); monobutyltin tris(2-ethylhexanoate); chloro butyl tin dihydroxide; tetra-n-propyl titanate; tetra-n-butyl titanate; zinc acetate; acidic compounds such as phosphoric acid; p-toluenesulfonic acid; dodecylbenzenesulfonic acid (DDBSA) and combinations thereof.

[0191] When present, the esterification catalyst can be used in an amount of 0.001 to 1% by weight, such as 0.01 to 0.2% by weight, such as 0.025 to 0.2% by weight, based on the total polymer components.

[0192] When present, the polyester material can be present in the UV - curable primer coating composition in any suitable amount. The UV - curable primer coating composition can comprise at least 1% by weight, such as at least 2% by weight, such as at least 5% by weight, such as at least 10% by weight of the polyester material, based on the total solids weight of the UV - curable primer coating composition. The UV - curable primer coating composition can comprise up to 50% by weight, such as up to 40% by weight, such as up to 30% by weight, such as up to 25% by weight, such as up to 20% by weight, such as up to 15% by weight of the polyester material, based on the total solids weight of the UV - curable primer coating composition.

[0193] The UV - curable primer coating composition can comprise 1 to 50% by weight, such as 2 to 50% by weight, such as 5 to 50% by weight, such as 10 to 50% by weight of the polyester material, based on the total solids weight of the UV - curable primer coating composition. The UV - curable primer coating composition can comprise 1 to 40% by weight, such as 2 to 40% by weight, such as 5 to 40% by weight, such as 10 to 40% by weight of the polyester material, based on the total solids weight of the UV - curable primer coating composition. The UV - curable primer coating composition can comprise 1 to 30% by weight, such as 2 to 30% by weight, such as 5 to 30% by weight, such as 10 to 30% by weight of the polyester material, based on the total solids weight of the UV - curable primer coating composition. The UV - curable primer coating composition can comprise 1 to 25% by weight, such as 2 to 25% by weight, such as 5 to 25% by weight, such as 10 to 25% by weight of the polyester material, based on the total solids weight of the UV - curable primer coating composition. The UV - curable primer coating composition can comprise 1 to 20% by weight, such as 2 to 20% by weight, such as 5 to 20% by weight, such as 10 to 20% by weight of the polyester material, based on the total solids weight of the UV - curable primer coating composition. The UV - curable primer coating composition can comprise 1 to 15% by weight, such as 2 to 15% by weight, such as 5 to 15% by weight, such as 10 to 15% by weight of the polyester material, based on the total solids weight of the UV - curable primer coating composition.

[0194] The UV - curable primer coating composition can comprise 5 to 20% by weight of the polyester material, based on the total solids weight of the UV - curable primer coating composition.

[0195] The UV - curable primer coating composition can comprise 5 to 15% by weight of a polyester material based on the total solids weight of the UV - curable primer coating composition.

[0196] The UV - curable primer coating composition can comprise 10 to 20% by weight of a polyester material based on the total solids weight of the UV - curable primer coating composition.

[0197] The UV - curable primer coating composition can comprise 10 to 15% by weight of a polyester material based on the total solids weight of the UV - curable primer coating composition.

[0198] UV curable topcoat coating composition

[0199] The multi - layer coating system can include a topcoat layer derived from a UV - curable topcoat coating composition, which comprises an epoxy material, a polyol material, and / or a diketone functional material and a photoinitiator. The terms "UV - curable topcoat coating composition" and "topcoat coating composition" can be used interchangeably herein. Any reference to the "topcoat coating composition" shall be construed as the topcoat coating composition being UV - curable unless otherwise specified.

[0200] The UV - curable topcoat coating composition comprises an epoxy material. Suitable epoxy materials are defined herein as for the UV - curable primer coating composition.

[0201] The epoxy material can be present in any suitable amount. The UV - curable topcoat coating composition can comprise at least 20% by weight, such as at least 30% by weight, such as at least 40% by weight, such as at least 50% by weight, such as at least 55% by weight, such as at least 60% by weight, such as at least 65% by weight of the epoxy material based on the total solids weight of the UV - curable topcoat coating composition. The UV - curable topcoat coating composition can comprise up to 99% by weight, such as up to 95% by weight, such as up to 90% by weight, such as up to 85% by weight, such as up to 80% by weight, such as up to 75% by weight of the epoxy material based on the total solids weight of the UV - curable topcoat coating composition.

[0202] The UV-curable topcoat coating composition may comprise 20 to 99 wt%, such as 30 to 99 wt%, such as 40 to 99 wt%, such as 50 to 99 wt%, such as 55 to 99 wt%, such as 60 to 99 wt%, such as 65 to 99 wt% of an epoxy material based on the total solids weight of the UV-curable topcoat coating composition. The UV-curable topcoat coating composition may comprise 20 to 95 wt%, such as 30 to 95 wt%, such as 40 to 95 wt%, such as 50 to 95 wt%, such as 55 to 95 wt%, such as 60 to 95 wt%, such as 65 to 95 wt% of an epoxy material based on the total solids weight of the UV-curable topcoat coating composition. The UV-curable topcoat coating composition may comprise 20 to 90 wt%, such as 30 to 90 wt%, such as 40 to 90 wt%, such as 50 to 90 wt%, such as 55 to 90 wt%, such as 60 to 90 wt%, such as 65 to 90 wt% of an epoxy material based on the total solids weight of the UV-curable topcoat coating composition. The UV-curable topcoat coating composition may comprise 20 to 85 wt%, such as 30 to 85 wt%, such as 40 to 85 wt%, such as 50 to 85 wt%, such as 55 to 85 wt%, such as 60 to 85 wt%, such as 65 to 85 wt% of an epoxy material based on the total solids weight of the UV-curable topcoat coating composition. The UV-curable topcoat coating composition may comprise 20 to 80 wt%, such as 30 to 80 wt%, such as 40 to 80 wt%, such as 50 to 80 wt%, such as 55 to 80 wt%, such as 60 to 80 wt%, such as 65 to 80 wt% of an epoxy material based on the total solids weight of the UV-curable topcoat coating composition. The UV-curable topcoat coating composition may comprise 20 to 75 wt%, such as 30 to 75 wt%, such as 40 to 75 wt%, such as 50 to 75 wt%, such as 55 to 75 wt%, such as 60 to 75 wt%, such as 65 to 75 wt% of an epoxy material based on the total solids weight of the UV-curable topcoat coating composition.

[0203] The UV-curable topcoat coating composition may comprise 50 to 90 wt% of an epoxy material based on the total solids weight of the UV-curable topcoat coating composition.

[0204] The UV-curable topcoat coating composition may comprise 55 to 85 wt% of an epoxy material based on the total solids weight of the UV-curable topcoat coating composition.

[0205] The UV-curable topcoat coating composition may comprise 60 to 80 wt% of an epoxy material based on the total solids weight of the UV-curable topcoat coating composition.

[0206] The UV curable topcoat coating composition may comprise 65 to 75 weight percent epoxy material based on the total solids weight of the UV curable topcoat coating composition.

[0207] The UV curable topcoat coating composition may comprise a polyol material. The polyol material may be any suitable polyol material. For example, the polyol material of the UV curable topcoat coating composition may comprise a hydroxy-functional polyester resin, a polycaprolactone, a polypropylene glycol, a fatty acid-modified dendrimer having two or more terminal hydroxy groups, such as 2 to 6 terminal hydroxy groups, such as 4 to 6 terminal hydroxy groups, such as 6 terminal hydroxy groups, and / or a hydroxy-functional vinyl resin. Examples of suitable hydroxy-functional polyester resins, polycaprolactones, polypropylene glycols, fatty acid-modified dendrimers, and hydroxy-functional vinyl resins are defined herein with respect to the UV curable primer coating composition.

[0208] The polyol material of the UV curable topcoat coating composition may comprise a commercially available polyol material and / or a commercially available hydroxy-functional polyester resin. Examples of suitable commercially available polyol materials and hydroxy-functional polyester resins are defined herein with respect to the UV curable primer coating composition.

[0209] The polyol material of the UV curable topcoat coating composition may have a hydroxyl value of at least 25 mg KOH / g.

[0210] The polyol material of the UV curable topcoat coating composition may have an OHV of at least 30 mg KOH / g, such as at least 40 mg KOH / g, such as at least 50 mg KOH / g, such as at least 60 mg KOH / g, such as at least 70 mg KOH / g, such as at least 80 mg KOH / g, such as at least 90 mg KOH / g, such as at least 100 mg KOH / g, such as at least 110 mg KOH / g, such as at least 120 mg KOH / g, such as at least 130 mg KOH / g, such as at least 140 mg KOH / g, such as at least 150 mg KOH / g, such as at least 200 mg KOH / g, such as at least 250 mg KOH / g. The polyol material of the UV curable topcoat coating composition may have an OHV of up to 650 mg KOH / g, such as up to 600 mg KOH / g, such as up to 550 mg KOH / g, such as up to 500 mg KOH / g, such as up to 450 mg KOH / g, such as up to 400 mg KOH / g.

[0211] The polyol material of the UV-curable topcoat coating composition can have any suitable acid value (AV; also known as acid number or AN). The polyol material of the UV-curable topcoat coating composition can have an acid value of up to 50 mg KOH / g, such as up to 30 mg KOH / g, such as up to 20 mg KOH / g, such as up to 10 mg KOH / g, such as up to 5 mg KOH / g, such as up to 4 mg KOH / g, such as up to 3 mg KOH / g, such as up to 2 mg KOH / g, such as up to 1 mg KOH / g.

[0212] The polyol material of the UV-curable topcoat coating composition can have any suitable number average molecular weight (Mn). The polyol material of the UV-curable topcoat coating composition can have at least 100 daltons (Da = g / mol), such as at least 200 Da, such as at least 250 Da, such as at least 300 Da of Mn. The polyol material of the UV-curable topcoat coating composition can have up to 50,000 Da, such as up to 25,000 Da, such as up to 20,000 Da, such as up to 10,000 Da, such as up to 5,000 Da, such as up to 4,500 Da, such as up to 4,000 Da, such as up to 3,500 Da of Mn.

[0213] The polyol material of the UV-curable topcoat coating composition can be a low molecular weight polyol material.

[0214] The polyol material of the UV-curable topcoat coating composition can have any suitable weight average molecular weight (Mw). The polyol material of the UV-curable topcoat coating composition can have at least 100 daltons (Da = g / mol), such as at least 200 Da, such as at least 250 Da, such as at least 300 Da of Mw. The polyol material of the UV-curable topcoat coating composition can have up to 50,000 Da, such as up to 25,000 Da, such as up to 20,000 Da, such as up to 10,000 Da, such as up to 5,000 Da, such as up to 4,500 Da, such as up to 4,000 Da, such as up to 3,500 Da of Mw.

[0215] The UV-curable topcoat coating composition can contain a diketone functional material. The diketone functional material can be any suitable diketone functional material. Examples of suitable diketone functional materials are defined herein for the UV-curable primer coating composition.

[0216] The UV-curable topcoat coating composition comprises a polyol material and / or a diketone functional material. The UV-curable topcoat coating composition may comprise a polyol material. The UV-curable topcoat coating composition may comprise any suitable amount of the polyol material. The UV-curable topcoat coating composition may comprise at least 2% by weight of the polyol material based on the total solids weight of the composition.

[0217] The UV-curable topcoat coating composition may comprise at least 3% by weight, such as at least 4% by weight, such as at least 5% by weight of the polyol material based on the total solids weight of the composition. The UV-curable topcoat coating composition may comprise up to 80% by weight, such as up to 70% by weight, such as up to 60% by weight, such as up to 50% by weight, such as up to 40% by weight, such as up to 30% by weight, such as up to 20% by weight, such as up to 15% by weight of the polyol material based on the total solids weight of the composition.

[0218] The UV-curable topcoat coating composition may comprise 2 to 80% by weight, such as 2 to 70% by weight, such as 2 to 60% by weight, such as 2 to 50% by weight, such as 2 to 40% by weight, such as 2 to 30% by weight, such as 2 to 20% by weight, such as 2 to 15% by weight of the polyol material based on the total solids weight of the composition. The UV-curable topcoat coating composition may comprise 3 to 80% by weight, such as 3 to 70% by weight, such as 3 to 60% by weight, such as 3 to 50% by weight, such as 3 to 40% by weight, such as 3 to 30% by weight, such as 3 to 20% by weight, such as 3 to 15% by weight of the polyol material based on the total solids weight of the composition. The UV-curable topcoat coating composition may comprise 4 to 80% by weight, such as 4 to 70% by weight, such as 4 to 60% by weight, such as 4 to 50% by weight, such as 4 to 40% by weight, such as 4 to 30% by weight, such as 4 to 20% by weight, such as 4 to 15% by weight of the polyol material based on the total solids weight of the composition. The UV-curable topcoat coating composition may comprise 5 to 80% by weight, such as 5 to 70% by weight, such as 5 to 60% by weight, such as 5 to 50% by weight, such as 5 to 40% by weight, such as 5 to 30% by weight, such as 5 to 20% by weight, such as 5 to 15% by weight of the polyol material based on the total solids weight of the composition.

[0219] The UV-curable topcoat coating composition may comprise at least 5% by weight of the polyol material based on the total solids weight of the composition.

[0220] The UV-curable topcoat coating composition may comprise 5 to 30% by weight of the polyol material based on the total solids weight of the composition.

[0221] The UV-curable topcoat coating composition can comprise 5 to 20% by weight of a polyol material based on the total solids weight of the composition.

[0222] The UV-curable topcoat coating composition can comprise 5 to 15% by weight of a polyol material based on the total solids weight of the composition.

[0223] The UV-curable topcoat coating composition can comprise a diketone functional material. The UV-curable topcoat coating composition can comprise any suitable amount of the diketone functional material. The UV-curable topcoat coating composition can comprise at least 2% by weight of the diketone functional material based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise at least 3% by weight, such as at least 4% by weight, such as at least 5% by weight of the diketone functional material based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise up to 80% by weight, such as up to 70% by weight, such as up to 60% by weight, such as up to 50% by weight, such as up to 40% by weight, such as up to 30% by weight, such as up to 20% by weight, such as up to 15% by weight of the diketone functional material based on the total solids weight of the composition.

[0224] The UV-curable topcoat coating composition can comprise 2 to 80% by weight, such as 2 to 70% by weight, such as 2 to 60% by weight, such as 2 to 50% by weight, such as 2 to 40% by weight, such as 2 to 30% by weight, such as 2 to 20% by weight, such as 2 to 15% by weight of the diketone functional material based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise 3 to 80% by weight, such as 3 to 70% by weight, such as 3 to 60% by weight, such as 3 to 50% by weight, such as 3 to 40% by weight, such as 3 to 30% by weight, such as 3 to 20% by weight, such as 3 to 15% by weight of the diketone functional material based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise 4 to 80% by weight, such as 4 to 70% by weight, such as 4 to 60% by weight, such as 4 to 50% by weight, such as 4 to 40% by weight, such as 4 to 30% by weight, such as 4 to 20% by weight, such as 4 to 15% by weight of the diketone functional material based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise 5 to 80% by weight, such as 5 to 70% by weight, such as 5 to 60% by weight, such as 5 to 50% by weight, such as 5 to 40% by weight, such as 5 to 30% by weight, such as 5 to 20% by weight, such as 5 to 15% by weight of the diketone functional material based on the total solids weight of the composition.

[0225] The UV-curable topcoat coating composition can comprise at least 5% by weight of the diketone functional material based on the total solids weight of the composition.

[0226] The UV curable topcoat coating composition may comprise from 5 to 30 weight percent of a diketone functional material based on the total solids weight of the composition.

[0227] The UV curable topcoat coating composition may comprise from 5 to 20 weight percent of a diketone functional material based on the total solids weight of the composition.

[0228] The UV curable topcoat coating composition may comprise from 5 to 15 weight percent of a diketone functional material based on the total solids weight of the composition.

[0229] The UV curable topcoat coating composition may not comprise a diketone functional material. For example, the UV curable topcoat coating composition may comprise less than 1 weight percent, such as less than 0.5 weight percent, such as less than 0.1 weight percent, such as less than 0.05 weight percent, such as substantially 0 weight percent of a diketone functional material based on the total solids weight of the composition.

[0230] The UV curable topcoat coating composition comprises a photoinitiator. The photoinitiator may be formed from any suitable photoinitiator. Examples of suitable photoinitiators are defined herein with respect to the UV curable primer coating composition.

[0231] The photoinitiator may be present in the UV curable topcoat coating composition in any suitable amount. The UV curable topcoat coating composition may comprise at least 0.1 weight percent, such as at least 0.5 weight percent, such as at least 1 weight percent, such as at least 2 weight percent, such as at least 3 weight percent of a photoinitiator based on the total solids weight of the composition. The UV curable topcoat coating composition may comprise up to 50 weight percent, such as up to 40 weight percent, such as up to 30 weight percent, such as up to 25 weight percent, such as up to 20 weight percent, such as up to 15 weight percent, such as up to 10 weight percent of a photoinitiator based on the total solids weight of the composition.

[0232] The UV-curable topcoat coating composition can comprise a photoinitiator in an amount of 0.1 to 50% by weight, such as 0.5 to 50% by weight, such as 1 to 50% by weight, such as 2 to 50% by weight, such as 3 to 50% by weight, based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise a photoinitiator in an amount of 0.1 to 40% by weight, such as 0.5 to 40% by weight, such as 1 to 40% by weight, such as 2 to 40% by weight, such as 3 to 40% by weight, based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise a photoinitiator in an amount of 0.1 to 30% by weight, such as 0.5 to 30% by weight, such as 1 to 30% by weight, such as 2 to 30% by weight, such as 3 to 30% by weight, based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise a photoinitiator in an amount of 0.1 to 25% by weight, such as 0.5 to 25% by weight, such as 1 to 25% by weight, such as 2 to 25% by weight, such as 3 to 25% by weight, based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise a photoinitiator in an amount of 0.1 to 20% by weight, such as 0.5 to 20% by weight, such as 1 to 20% by weight, such as 2 to 20% by weight, such as 3 to 20% by weight, based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise a photoinitiator in an amount of 0.1 to 15% by weight, such as 0.5 to 15% by weight, such as 1 to 15% by weight, such as 2 to 15% by weight, such as 3 to 15% by weight, based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise a photoinitiator in an amount of 0.1 to 10% by weight, such as 0.5 to 10% by weight, such as 1 to 10% by weight, such as 2 to 10% by weight, such as 3 to 10% by weight, based on the total solids weight of the composition.

[0233] The UV-curable topcoat coating composition can comprise a photoinitiator in an amount of 1 to 10% by weight based on the total solids weight of the composition.

[0234] The UV-curable topcoat coating composition can comprise a photoinitiator in an amount of 2 to 8% by weight based on the total solids weight of the composition.

[0235] The UV-curable topcoat coating composition can further comprise wax. As used herein, "wax" means a hydrophobic, malleable solid at near ambient temperature that exhibits a low viscosity in the molten phase.

[0236] The wax can comprise micronized wax and micronized polysaccharide. As used herein, the term "micronized" takes its ordinary meaning of particles having a D50 value in the micron range. For example, the micronized particles can have a D50 value of up to 100 μm, such as up to 50 μm, such as up to 30 μm or up to 10 μm. Micronization can be achieved by any suitable means known to those skilled in the art, including by mechanical means such as milling and grinding. The D50 value can be measured by any suitable method. Methods for measuring the D50 value will be known to those skilled in the art. The D50 values reported herein were measured using a Malvern Mastersizer 2000 laser diffraction test instrument, as is known to those skilled in the art.

[0237] The micronized wax can include any suitable wax, such as polyolefin wax, Fischer-Tropsch wax, polyamide wax, carnauba wax, and / or paraffin wax.

[0238] The micronized wax can include polyolefin wax, such as polyethylene wax and / or polypropylene wax.

[0239] The micronized polysaccharide can be in the form of wax or can not be wax. The micronized polysaccharide can include polysaccharide wax. When the micronized polysaccharide includes polysaccharide wax, the UV curable topcoat coating composition can contain additional micronized wax that does not contain polysaccharide. In other words, when the micronized polysaccharide includes micronized polysaccharide wax, the UV curable topcoat coating composition can further contain additional micronized wax, such as polyolefin wax, Fischer-Tropsch wax, polyamide wax, carnauba wax, and / or paraffin wax (e.g., polyolefin wax) as described herein.

[0240] The micronized polysaccharide can include any suitable micronized polysaccharide, such as polysaccharides containing glucose units (such as glucose monomers linked by α-glycosidic bonds). The micronized polysaccharide can include starch, glycogen, cellulose, cellulose, chitosan, chitin, amylose, and / or cane sugar (such as starch, glycogen, cellulose, cellulose, chitosan, chitin, and / or amylose).

[0241] The weight ratio of micronized wax to micronized polysaccharide can be at least 95:5, such as at least 90:10. The weight ratio of micronized wax to micronized polysaccharide can be up to 5:95, such as up to 80:20. The weight ratio of micronized wax to micronized polysaccharide can be from 95:5 to 5:95, such as from 90:10 to 80:20.

[0242] Micronized wax and micronized polysaccharide can be included in the UV-curable topcoat coating composition as separate components or as an additive composition comprising micronized wax and micronized polysaccharide (e.g., where the micronized wax and micronized polysaccharide are premixed to form the additive composition). The additive composition can comprise micronized wax and micronized polysaccharide, such as where the wax and polysaccharide are processed and / or micronized prior to use to provide the desired particle size.

[0243] The UV-curable topcoat coating composition can comprise any suitable amount of wax. The UV-curable topcoat coating composition can comprise at least 0.01 wt%, such as at least 0.05 wt%, such as at least 0.1 wt%, such as at least 0.2 wt%, such as at least 0.3 wt%, such as at least 0.4 wt%, such as at least 0.5 wt% of wax based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise up to 5 wt%, such as up to 4 wt%, such as up to 3 wt%, such as up to 2 wt%, such as up to 1 wt% of wax based on the total solids weight of the composition.

[0244] The UV-curable topcoat coating composition can comprise from 0.01 to 5 wt%, such as from 0.05 to 5 wt%, such as from 0.1 to 5 wt%, such as from 0.2 to 5 wt%, such as from 0.3 to 5 wt%, such as from 0.4 to 5 wt%, such as from 0.5 to 5 wt% of wax based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise from 0.01 to 4 wt%, such as from 0.05 to 4 wt%, such as from 0.1 to 4 wt%, such as from 0.2 to 4 wt%, such as from 0.3 to 4 wt%, such as from 0.4 to 4 wt%, such as from 0.5 to 4 wt% of wax based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise from 0.01 to 3 wt%, such as from 0.05 to 3 wt%, such as from 0.1 to 3 wt%, such as from 0.2 to 3 wt%, such as from 0.3 to 3 wt%, such as from 0.4 to 3 wt%, such as from 0.5 to 3 wt% of wax based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise from 0.01 to 2 wt%, such as from 0.05 to 2 wt%, such as from 0.1 to 2 wt%, such as from 0.2 to 2 wt%, such as from 0.3 to 2 wt%, such as from 0.4 to 2 wt%, such as from 0.5 to 2 wt% of wax based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise from 0.01 to 1 wt%, such as from 0.05 to 1 wt%, such as from 0.1 to 1 wt%, such as from 0.2 to 1 wt%, such as from 0.3 to 1 wt%, such as from 0.4 to 1 wt%, such as from 0.5 to 1 wt% of wax based on the total solids weight of the composition.

[0245] The UV curable topcoat coating composition may comprise a (meth)acrylate functional material. As used herein, "(meth)acrylate functional" and like terms mean a material that contains a (meth)acrylate functional group as its end group or side chain, typically a resin. The (meth)acrylate functional group suitably provides the material with reactive functional groups such as ethylenic unsaturation that can participate in crosslinking reactions during curing. The UV curable topcoat coating composition may comprise any suitable (meth)acrylate functional material. The (meth)acrylate functional material may comprise a (meth)acrylate functional resin. Examples of suitable (meth)acrylate functional materials include, but are not limited to, (meth)acrylate functional polyesters, (meth)acrylate functional polyurethanes, (meth)acrylate functional epoxy materials, and combinations thereof.

[0246] (Meth)acrylate functional materials may include commercially available materials. Examples of suitable commercially available (meth)acrylate functional materials include, but are not limited to, those sold under the trade name Mirame (commercially available from Miwon Specialty Chemical Co.), such as Miramer S5242, Miramer PS6300, Miramer PS460, Miramer P2229, Miramer PU610, Miramer SC2100, Miramer ME2500, and Miramer PE2130; those sold under the trade name Sartomer (commercially available from Arkema), such as Sartomer CN704, Sartomer 790, Sartomer CN965, and Sartomer CN981; those sold under the trade name Laromer (commercially available from BASF), such as Laromer LR 8863 and Laromer UP 9118; those sold under the trade name Ebecryl (commercially available from Allnex), such as Ebecryl 416, Ebecryl 895, Ebecryl 1885, Ebecryl 4690, Ebecryl 8894, and Ebecryl PEG200DMA; and combinations thereof.

[0247] The UV-curable topcoat coating composition can comprise any suitable amount of (meth)acrylate functional material. The UV-curable topcoat coating composition can comprise at least 1 wt%, such as at least 2 wt%, such as at least 3 wt%, such as at least 4 wt%, such as at least 5 wt%, such as at least 6 wt%, such as at least 7 wt%, such as at least 8 wt%, such as at least 9 wt%, such as at least 10 wt% of (meth)acrylate functional material based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise up to 50 wt%, such as up to 40 wt%, such as up to 30 wt%, such as up to 20 wt%, or even up to 15 wt% of (meth)acrylate functional material based on the total solids weight of the composition.

[0248] The UV-curable topcoat coating composition can comprise 1 to 50 wt%, such as 2 to 50 wt%, such as 3 to 50 wt%, such as 4 to 50 wt%, such as 5 to 50 wt%, such as 6 to 50 wt%, such as 7 to 50 wt%, such as 8 to 50 wt%, such as 9 to 50 wt%, such as 10 to 50 wt% of (meth)acrylate functional material based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise 1 to 40 wt%, such as 2 to 40 wt%, such as 3 to 40 wt%, such as 4 to 40 wt%, such as 5 to 40 wt%, such as 6 to 40 wt%, such as 7 to 40 wt%, such as 8 to 40 wt%, such as 9 to 40 wt%, such as 10 to 40 wt% of (meth)acrylate functional material based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise 1 to 30 wt%, such as 2 to 30 wt%, such as 3 to 30 wt%, such as 4 to 30 wt%, such as 5 to 30 wt%, such as 6 to 30 wt%, such as 7 to 30 wt%, such as 8 to 30 wt%, such as 9 to 30 wt%, such as 10 to 30 wt% of (meth)acrylate functional material based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise 1 to 20 wt%, such as 2 to 20 wt%, such as 3 to 20 wt%, such as 4 to 20 wt%, such as 5 to 20 wt%, such as 6 to 20 wt%, such as 7 to 20 wt%, such as 8 to 20 wt%, such as 9 to 20 wt%, such as 10 to 20 wt% of (meth)acrylate functional material based on the total solids weight of the composition. The UV-curable topcoat coating composition can comprise 1 to 15 wt%, such as 2 to 15 wt%, such as 3 to 15 wt%, such as 4 to 15 wt%, such as 5 to 15 wt%, such as 6 to 15 wt%, such as 7 to 15 wt%, such as 8 to 15 wt%, such as 9 to 15 wt%, such as 10 to 15 wt% of (meth)acrylate functional material based on the total solids weight of the composition.

[0249] The UV-curable topcoat coating composition may comprise 8 to 20% by weight, such as 9 to 20% by weight, such as 10 to 15% by weight, of a (meth)acrylate functional material based on the total solids weight of the composition.

[0250] The UV-curable topcoat coating composition may comprise a free radical photoinitiator. For example, the UV-curable topcoat coating composition may comprise a (meth)acrylate functional material and a free radical photoinitiator.

[0251] Examples of suitable free radical initiators include, but are not limited to: 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl phenylglyoxylate; 2-[2-hydroxy-ethoxy]-ethyl phenylglyoxylate; tert-butyl perbenzoate; tert-butyl peroxy 3,5,5-trimethylhexanoate; tert-butyl peroxy 2-ethylhexanoate; tert-amyl peroxy 2-ethylhexanoate; di-tert-butyl peroxide; tert-butyl peracetate; tert-butyl peroctoate; azo-type initiators such as, for example, 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile) and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile); persulfate initiators such as, for example, ammonium persulfate, sodium persulfate or potassium persulfate; and combinations thereof.

[0252] The free radical photoinitiator may comprise 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl phenylglyoxylate and / or 2-[2-hydroxy-ethoxy]-ethyl phenylglyoxylate, such as 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl phenylglyoxylate and 2-[2-hydroxy-ethoxy]-ethyl phenylglyoxylate.

[0253] Examples of suitable commercially available free radical photoinitiators include, but are not limited to, those sold under the trade name Omnirad (commercially available from IGM Resins), such as Omnirad 754, Omnirad 1173, Omnirad 184 and Omnirad TPO; those sold under the trade name Genocure (commercially available from Rahn Group), such as Genocure TPO, Genocure MBF and Genocure LBC.

[0254] A free radical photoinitiator can be present in the UV curable topcoat coating composition in any suitable amount. The UV curable topcoat coating composition can comprise at least 0.1 wt%, such as at least 0.5 wt%, such as at least 1 wt% of a free radical photoinitiator based on the total solids weight of the composition. The UV curable topcoat coating composition can comprise up to 5 wt%, such as up to 4 wt%, such as up to 3 wt%, such as up to 2 wt%, such as up to 1 wt% of a free radical photoinitiator based on the total solids weight of the composition.

[0255] Additional coating ingredients

[0256] The UV curable primer coating composition and / or the UV curable topcoat coating composition can comprise additional resin materials. Suitable additional resin materials will be well known to those skilled in the art. Examples of suitable additional resin materials include, but are not limited to, acrylic resins; polyvinyl chloride (PVC) resins; alkyd resins; polyurethane resins; polysiloxane resins; or combinations thereof.

[0257] The UV curable primer coating composition and / or the UV curable topcoat coating composition can comprise other optional materials well known in the art of formulating coatings, such as colorants, plasticizers, wear-resistant particles, antioxidants, hindered amine light stabilizers, UV light absorbers and stabilizers, surfactants, flow control agents, thixotropic agents, fillers, organic cosolvents, reactive diluents, catalysts, grinding media, lubricants, waxes, and other common additives.

[0258] As used herein, the term "colorant" means any substance that imparts color and / or other opacity and / or other visual effects to the composition. The colorant can be added to the coating composition in any suitable form, such as discrete particles, dispersions, solutions, and / or flakes. A single colorant or a mixture of two or more colorants can be used in the coating composition. Suitable colorants are listed in U.S. Patent No. 8,614,286, columns 7, line 2 to column 8, line 65, which is incorporated herein by reference. Examples of colorants for packaging coating compositions are those approved for food contact, such as titanium dioxide; iron oxides, such as black iron oxide; aluminum paste; aluminum powder, such as aluminum flakes; carbon black; ultramarine blue; phthalocyanines, such as phthalocyanine blue and phthalocyanine green; chromium oxides, such as chromium oxide green; graphite fibrils; iron yellow; quindo red; and combinations thereof, as well as those listed in Title 21, Code of Federal Regulations, Section 178.3297, which is incorporated herein by reference.

[0259] When an ultraviolet curable composition is desired, the colorants utilized are typically ultraviolet light transparent pigments. The phrase "ultraviolet light transparent" is used to mean that the pigment does not substantially interfere with the UV curing of the composition. Examples of ultraviolet light transparent pigments include, but are not limited to, talc, calcium carbonate, aluminum silicate, magnesium silicate, barite, and silica (SiO2). Colorants that are typically used to impart color in non-UV curable coating compositions typically absorb or block ultraviolet light, thus interfering with the UV curing of the composition. Thus, in cases where a certain degree of coloration of the composition is desired, when curing is carried out using UV, such conventional coloring pigments are typically used only in limited amounts.

[0260] When present, the colorant can be used in any suitable amount in the UV curable primer coating composition and / or the UV curable topcoat coating composition. When present, the colorant can be used in an amount of up to 90 wt%, such as up to 50 wt%, or even up to 10 wt% based on the total solids weight of the composition in the UV curable primer coating composition and / or the UV curable topcoat coating composition.

[0261] Suitable reactive diluents will be known to those skilled in the art. Examples of suitable commercially available reactive diluents include, but are not limited to, those sold under the trade name D.E.R. (RTM), such as D.E.R. 731; those sold under the trade name Curalite (commercially available from Perstorp), such as Curalite OX; those sold under the trade name Uvi-Cure (commercially available from Arkema), such as Uvi-Cure S170, S160, S130, and S140.

[0262] When present, the reactive diluent can contain oxetane groups. The reactive diluent can contain one or more oxetane groups. For example, a reactive diluent containing an oxetane group can be in the form of a monomer, dimer, oligomer, etc. The oxetane group can be substituted or unsubstituted. For example, the oxetane group can be substituted by an alkyl, alkenyl, alkynyl, or aryl group, such as an alkyl group, such as a C1-C10 alkyl group, such as a C1-C6 alkyl group, such as a C1-C4 alkyl group, such as methyl or ethyl, such as ethyl. The oxetane group can additionally or alternatively be substituted by a hydroxy group, such as a group of the formula –(X) n -OH group, where X is an organic bridging group, such as a C1-C10 alkylene group, such as a C1-C6 alkylene group, such as a C1-C4 alkylene group, such as methylene or ethylene, such as methylene, and n is 0 or 1, such as 1.

[0263] Examples of suitable commercially available reactive diluents containing an oxetane group include, but are not limited to, those sold under the trade name Curalite (commercially available from Perstorp), such as Curalite OX, and those sold under the trade name Uvi-Cure (commercially available from Arkema), such as Uvi-Cure S170, S160, S130, and S140.

[0264] The reactive diluent can be present in any suitable amount. The UV-curable primer coating composition and / or the UV-curable topcoat coating composition can contain at least 1% by weight, such as at least 2% by weight, such as at least 3% by weight, such as at least 4% by weight, such as at least 5% by weight of the reactive diluent based on the total solids weight of the composition. The UV-curable primer coating composition and / or the UV-curable topcoat coating composition can contain up to 50% by weight, such as up to 40% by weight, such as up to 30% by weight, such as up to 25% by weight, such as up to 20% by weight of the reactive diluent based on the total solids weight of the composition.

[0265] The UV-curable primer coating composition and / or the UV-curable topcoat coating composition can contain 5 to 50% by weight, such as 5 to 40% by weight, such as 5 to 30% by weight, such as 5 to 25% by weight, such as 5 to 20% by weight of the reactive diluent based on the total solids weight of the composition. The UV-curable primer coating composition and / or the UV-curable topcoat coating composition can contain 4 to 50% by weight, such as 4 to 40% by weight, such as 4 to 30% by weight, such as 4 to 25% by weight, such as 4 to 20% by weight of the reactive diluent based on the total solids weight of the composition. The UV-curable primer coating composition and / or the UV-curable topcoat coating composition can contain 3 to 50% by weight, such as 3 to 40% by weight, such as 3 to 30% by weight, such as 3 to 25% by weight, such as 3 to 20% by weight of the reactive diluent based on the total solids weight of the composition. The UV-curable primer coating composition and / or the UV-curable topcoat coating composition can contain 2 to 50% by weight, such as 2 to 40% by weight, such as 2 to 30% by weight, such as 2 to 25% by weight, such as 2 to 20% by weight of the reactive diluent based on the total solids weight of the composition. The UV-curable primer coating composition and / or the UV-curable topcoat coating composition can contain 1 to 50% by weight, such as 1 to 40% by weight, such as 1 to 30% by weight, such as 1 to 25% by weight, such as 5 to 20% by weight of the reactive diluent based on the total solids weight of the composition.

[0266] The UV-curable primer coating composition and / or the UV-curable topcoat coating composition can contain 5 to 20% by weight of the reactive diluent based on the total solids weight of the composition.

[0267] Suitable lubricants are known to those skilled in the art. Examples of suitable lubricants include, but are not limited to, lanolin wax; polytetrafluoroethylene (PTFE) waxes such as Lanco TF 1780 commercially available from Lubrizol; carnauba wax; polyethylene-type lubricants such as polyethylene wax, for example Lanco SF 1500 commercially available from Lubrizol; microcrystalline waxes such as Lubaprint 121 / F commercially available from Munzing, Ceracol 615 commercially available from BYK; and combinations thereof. When present, the lubricant can be used in the UV curable primer coating composition and / or the UV curable topcoat coating composition in an amount of at least 0.01 wt% based on the total solids weight of the composition.

[0268] The UV curable primer coating composition, the UV curable topcoat coating composition, and / or the multi-layer coating system can be substantially free of, can be essentially free of, or can be completely free of polytetrafluoroethylene (PTFE). "Substantially free" is intended to mean that the coating composition, coating system, or its components contain less than 1000 parts per million (ppm) of PTFE. "Essentially free" is intended to mean that the coating composition, coating system, or its components contain less than 100 ppm of PTFE. "Completely free" is intended to mean that the coating composition, coating system, or its components contain less than 20 parts per billion (ppb) of PTFE. The UV curable topcoat coating composition and / or the coating system can contain 0 wt% of PTFE.

[0269] Surfactants can optionally be added to the UV curable primer coating composition and / or the UV curable topcoat coating composition to assist in the flow and wetting of the substrate. Suitable surfactants are known to those skilled in the art. Surfactants (when present) compatible with food and / or beverage packaging applications can be selected. Examples of suitable surfactants include, but are not limited to, alkyl sulfates (such as sodium dodecyl sulfate); ether sulfates; phosphates; sulfonates; and their various base, ammonium, amine salts; fatty alcohol ethoxylates; alkylphenol ethoxylates (such as nonylphenol polyethers); salts; polyether siloxane copolymers, such as those sold under the trade name Tego Glide(RTM), e.g., Tego Glide B 1484 commercially available from Evonik; polysiloxanes, such as those sold under the trade name Borchi(RTM), e.g., Borchi Gol 1376 commercially available from Borchers, those sold under the trade name BYK(RTM), e.g., BYK 313 and BYK 370 commercially available from BYK Chemie, and those sold under the trade name Tego Glide(RTM), e.g., Tego Glide 496 commercially available from Evonik; polyvinyl polymers, such as those sold under the trade name Dynoadd(RTM), e.g., Dynoadd F300 commercially available from Dynea; silicone polyesters, such as those sold under the trade name Silikovtal(RTM), e.g., Silikovtal HTT commercially available from Evonik and / or combinations thereof. When present, the surfactant can be present in an amount of 0.01 to 10 wt%, such as 0.01 to 5 wt%, or even 0.01 to 2 wt% based on the total solids weight of the composition.

[0270] Suitable plasticizers are known to those skilled in the art. Examples of suitable plasticizers include, but are not limited to, esters such as those sold under the trade name Dioplex(RTM), e.g., Dioplex 907 commercially available from Hallstar; polybutadiene diols such as those sold under the trade name Krasol(RTM), e.g., Krasol F3000 commercially available from Cray Valley and those sold under the trade name Poly bd(RTM), e.g., Polybd605E and Poly bd R45HTLO commercially available from Total; epoxidized soybean oil such as EFKA(RTM)PL5382 commercially available from BASF; polyurethane diols such as those sold under the trade name K Flex(RTM), e.g., KFlex UD 320 commercially available from KingIndustries; aliphatic diols such as those sold under the trade name K POL(RTM), e.g., K POL 8211 commercially available from King Industries; polyols such as those sold under the trade name Cardolite(RTM), e.g., Cardolite NX-9001, 9007 and 9014 commercially available from Cardolite; thermoplastic methacrylate polymers such as those sold under the trade name Degalan(RTM), e.g., Degalan LP 6511 and 6512 commercially available from ROHM; polyvinyl butyral such as those sold under the trade name Mowital(RTM), e.g., MowitalB14S, B16H, BA 20S, B 60HH and B30T commercially available from Kuraray; polytetrahydrofuran (THF) elastomers (such as those available from BASF); polyesters such as those sold under the trade name Dynapol 9RTM, e.g., DynapolLS 615 and Dynapol LS 415 commercially available from Evonik, those sold under the trade name Vitel(RTM), e.g., Vitel 3200 commercially available from Bostik and those sold under the trade name Uralac(RTM), e.g., UralacCP4197, SH994, SN908 and SH 979 commercially available from DSM; and combinations thereof. When present, the plasticizer can be used in the UV curable primer coating composition and / or the UV curable topcoat coating composition in an amount of 0.01 to 20 wt%, such as 0.01 to 15 wt%, such as 0.01 to 10 wt%, such as 0.01 to 5 wt%, or even 0.02 to 2 wt% based on the total weight of the composition.

[0271] The UV curable primer coating composition and / or the UV curable topcoat coating composition can have any suitable solids content. The solids content of the UV curable primer coating composition and / or the UV curable topcoat coating composition can be at least 90% by weight based on the total weight of the UV curable topcoat coating composition.

[0272] The solids content of the UV curable primer coating composition and / or the UV curable topcoat coating composition can be at least 91% by weight, such as at least 92% by weight, such as at least 93% by weight, such as at least 94% by weight, such as at least 95% by weight, such as at least 96% by weight, such as at least 97% by weight, such as at least 98% by weight, such as at least 99% by weight, such as at least 99.5% by weight, such as at least 99.9% by weight, based on the total weight of the composition.

[0273] The solids content of the UV curable primer coating composition and / or the UV curable topcoat coating composition can be at least 95% by weight based on the total weight of the composition.

[0274] The UV curable primer coating composition and / or the UV curable topcoat coating composition can contain up to 10% by weight, such as up to 5% by weight, of a liquid carrier based on the total weight of the composition.

[0275] The UV curable primer coating composition and / or the UV curable topcoat coating composition can contain up to 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5 or 0.01% by weight of one or more liquids based on the total weight of the composition. The liquid may be present due to the use of one or more viscous components. For example, the liquid can be present as part of one or more components (i.e., raw material components) of the composition and is not added directly as a solvent.

[0276] The UV curable primer coating composition and / or the UV curable topcoat coating composition can contain up to 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5 or 0.01% by weight of one or more organic solvents based on the total weight of the composition. When present, the solvent suitably has sufficient volatility to substantially completely evaporate from the coating composition during the curing process.

[0277] Suitable organic solvents include, but are not limited to, aliphatic hydrocarbons such as mineral spirits and high flash naphtha; aromatic hydrocarbons such as toluene; xylene; solvent naphthas 100, 150, 150ND, 200 and / or 200ND; those available from Exxon-Mobil Chemical Company under the trade name SOLVESSO(RTM); alcohols such as ethanol, n-propanol, isopropanol, n-butanol, 2-butoxyethanol and 1-methoxypropan-2-ol, diacetone alcohol; ketones such as acetone, cyclohexanone, methyl isobutyl ketone and methyl ethyl ketone; esters such as ethyl acetate, butyl acetate, n-hexyl acetate, binary esters commercially available from Sigma Aldrich, propylene glycol methyl ether acetate, butyl glycol acetate, butyl diglycol acetate and RHODIASOLV(RTM) RPDE (a mixture of succinate and adipate esters commercially available from Solvay); diols such as butanediol and dibutylene glycol; ethylene glycol ethers such as methoxypropanol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol methyl ether and dipropylene glycol monomethyl ether; and combinations thereof.

[0278] The UV curable overcoat coating composition can suitably form a protective coating after curing.

[0279] The UV curable overcoat coating composition can be substantially transparent. "Substantially transparent" means that the UV curable overcoat coating composition is transparent / semitransparent enough once cured to allow the underlying ink layer to be visible.

[0280] The UV curable overcoat coating composition can be colorless. "Colorless" means that the UV curable overcoat coating composition can be substantially free, can be largely free or can be completely free of pigments. "Substantially free" means that the coating composition contains less than 1 wt% of pigments based on the total solids weight of the coating composition. "Largely free" means that the coating composition contains less than 0.1 wt% of pigments based on the total solids weight of the coating composition. "Completely free" means that the coating composition contains less than 0.001 wt% of pigments based on the total solids weight of the coating composition.

[0281] Ink composition

[0282] The multi-layer coating system includes an ink layer derived from an ink composition.

[0283] The term "ink composition" or "ink" (which may be used interchangeably herein) will be familiar to those skilled in the art. For example, as used herein, "ink composition", "ink" and similar terms mean a powder, fluid or paste such as a gel, sol (colloidal suspension) or solution that contains at least one colorant and can be used for printing, i.e., can be used to impart color to a surface to produce an image, text or design, etc.

[0284] The ink can be operably disposed on at least a portion of a UV curable primer coating composition or a primer coating derived therefrom. When present, the UV curable topcoat coating composition can be operably disposed on at least a portion of the ink composition or an ink layer derived therefrom.

[0285] The ink can be any suitable ink. Suitable inks will be known to those skilled in the art. The ink can be selected from inks commonly commercially available for two-piece and three-piece cans, including those provided by INX, Triton, and SunChemical.

[0286] The ink can comprise a variety of suitable components, including but not limited to dyes, pigments, resins, solvents, and / or additives. Examples of suitable additives include but are not limited to lubricants, fluorescent agents, waxes, curing accelerators (such as photo-curing accelerators), and combinations thereof.

[0287] The ink can be liquid or powder. Such terms associated with ink will be known to those skilled in the art. However, for the sake of clarity, as used herein, "powder" and similar terms refer to materials in the form of solid fine particles as opposed to materials in liquid form.

[0288] The ink can be applied to at least a portion of a UV curable primer coating composition or a primer coating derived therefrom. One or more inks can be applied. One or more inks can be applied in a specific pattern, such as to impart text and / or images to the primer coating (and the underlying substrate). Typically, more than one ink will be applied to impart images to the primer coating (and the underlying substrate).

[0289] The ink can be applied by any suitable method. The ink can be applied by digital printing. As used herein, "digital printing" and similar terms refer to methods of directly printing a digital-based image onto a substrate. Thus, the ink layer can be directly applied to a substrate having a primer coating thereon. In contrast, offset printing, for example, is a printing technique where the image is transferred (or "offset") from a printing plate to a rubber blanket and then to the printing surface (i.e., the image is not directly transferred to the substrate).

[0290] Thus, the ink can be an ink suitable for digital printing (e.g., as opposed to offset printing inks). The ink can be a digital printing ink.

[0291] The ink can be applied by digital printing.

[0292] The ink can be applied to at least a portion of a UV curable primer coating composition or a primer coating derived therefrom.

[0293] The ink can be cured to form an ink layer. The ink can be cured by any suitable method. Suitable methods are known to those skilled in the art. For example, the ink can be cured by exposure to radiation. The radiation can be, for example, high-energy radiation or actinic radiation.

[0294] One type of high-energy radiation curing includes electron beam curing.

[0295] One type of actinic radiation that can be used herein is ultraviolet light (UV) and other forms of actinic radiation commonly found in radiation emitted from the sun or from artificial sources such as RS-type sun lamps, carbon arc lamps, gas discharge tubes such as xenon arc lamps, mercury vapor lamps, tungsten halogen lamps, pulsed and non-pulsed TV lasers, UV point radiators such as UV-emitting diodes and blacklight tubes, electrodeless microwave-powered lamps, etc. Ultraviolet radiation can be used most effectively, and the ink composition contains a suitable photo-curing rate promoter. By appropriately selecting the ultraviolet light source, photo-curing rate promoter, and their concentrations and / or temperature, the curing period can be adjusted to be very short and thus commercially economical.

[0296] The ink composition can be UV curable.

[0297] Multilayer system

[0298] A multi-layer coating system can be applied to any suitable substrate. A multi-layer coating system can be applied to any suitable substrate and cured. For example, a UV curable primer coating composition and an ink composition can be each applied to the substrate and cured to form a multi-layer coating system comprising a primer coating and an ink layer. For example, an ink composition and a UV curable topcoat coating composition can be each applied to the substrate and cured to form a multi-layer coating system comprising an ink layer and a topcoat coating.

[0299] The multi-layer coating system can comprise a UV curable primer composition and a UV curable coating composition each according to the present invention. Thus, the multi-layer coating system can include:

[0300] i) A primer coating, the primer coating being derived from a UV curable coating composition according to the present invention;

[0301] ii) An ink layer, the ink layer being directly disposed on the primer coating, the ink layer being derived from an ink composition;

[0302] and

[0303] iii) A topcoat coating, the topcoat coating being directly disposed on the ink layer, the topcoat coating being derived from a UV curable topcoat coating composition according to the present invention.

[0304] Such multi-layer coating systems can be applied to any substrate disclosed herein.

[0305] Each layer can be independently cured by any suitable method. For example, a UV-curable primer coating composition can be partially cured or fully cured before applying the ink composition. The ink composition can be partially cured or fully cured before applying the UV-curable topcoat coating composition.

[0306] The UV-curable primer coating composition can be fully cured before applying the ink composition.

[0307] The ink composition can be fully cured before applying the UV-curable topcoat coating composition.

[0308] Those skilled in the art will understand that, for example, when the ink composition is applied to the UV-curable primer coating composition before curing of the UV-curable primer coating composition, the application of the ink composition will be a so-called "wet-on-wet" application. Then the UV-curable primer coating composition and the ink composition can be cured simultaneously.

[0309] The UV-curable primer coating composition and / or the UV-curable topcoat coating composition can be cured according to the methods described herein (such as by exposure to UV radiation).

[0310] The ink composition can be cured according to the methods defined herein (such as by exposure to UV radiation).

[0311] Additional coatings

[0312] The multi-layer coating system of the present invention can include one or more additional coatings.

[0313] The additional coatings can be derived from one or more additional coating compositions. The additional coatings can comprise any suitable paint, such as those containing, for example: epoxy resins; polyester resins; polyurethane resins; polysiloxane resins; hydrocarbon resins or combinations thereof. The additional coatings can be liquid coatings or powder coatings.

[0314] The multi-layer coating system can include a primer coating derived from a primer coating composition. As used herein, "primer coating", "primer coating composition", etc. refer to a coating applied below one or more of the coatings or ink layers defined herein. For example, the primer coating can be applied below an ink layer as defined herein and / or below a primer coating layer derived from a UV-curable primer coating composition as defined herein. For the avoidance of doubt, "primer coating", "primer coating composition", etc. are distinguished from the primer coating layer derived from the UV-curable primer coating composition of the present invention (and as defined herein).

[0315] The primer coating can be derived from a thermosettable primer coating composition.

[0316] When the substrate is an aluminum package such as an aluminum one-piece spray can and / or tube, the multi-layer coating system can include a primer layer derived from a primer coating composition, an ink layer derived from an ink composition, and an outer coating layer derived from the UV-curable outer coating composition of the present invention (and as defined herein).

[0317] The multi-layer coating system can include a topcoat layer derived from a topcoat coating composition. As used herein, "topcoat layer", "topcoat coating composition", etc. refer to a coating applied on top of one or more of the coatings or ink layers defined herein. For the avoidance of doubt, "topcoat layer", "topcoat coating composition", etc. are distinct from the topcoat layer derived from the UV-curable topcoat coating composition of the present invention (and as defined herein).

[0318] The topcoat layer can be derived from a thermosettable topcoat coating composition.

[0319] The primer coating composition and / or the topcoat coating composition can comprise one or more components selected from, but not limited to, resin binders, solvents, crosslinking agent materials, additives, and combinations thereof. The primer composition and / or the topcoat coating composition can comprise a resin binder and one or more additives. For example, when it is desired that the primer composition and / or the topcoat coating composition be UV-curable, the primer composition and / or the topcoat coating composition comprise a photoinitiator.

[0320] Examples of suitable resin binders that can be present in the primer coating composition and / or the topcoat coating composition include, but are not limited to, polyester resins; acrylic resins; polyvinyl chloride (PVC) resins; alkyd resins; polyurethane resins; polysiloxane resins; epoxy resins, or combinations thereof.

[0321] Examples of suitable solvents that can be present in the primer coating composition and / or the topcoat coating composition are as defined herein with respect to the UV-curable primer coating composition and / or the UV-curable outer coating composition. The primer coating composition and / or the topcoat coating composition can be solvent-based. "Solvent-based" means that the composition comprises one or more organic solvents as carriers and up to 20% by volume, such as up to 10% by volume, such as up to 5% by volume, such as up to 1% by volume, of water based on the total volume of the carriers present. The primer coating composition and / or the topcoat coating composition can comprise 100% by volume of solvent based on the total volume of the carriers present.

[0322] Examples of suitable crosslinking agent materials that can be present in the primer coating composition and / or the topcoat coating composition include, but are not limited to, the following: phenolic resins (or phenol-formaldehyde resins); aminoplast resins (or triazine formaldehyde resins); amino resins; epoxy resins; epoxy mimic resins, such as those based on bisphenols and other bisphenol A (BPA) alternatives; isocyanate resins, isocyanurate resins, such as triglycidyl isocyanurate; hydroxy(alkyl)amide resins, such as β-hydroxy(alkyl)amide resins; hydroxy(alkyl)urea resins; carbodiimide resins, such as polycarbodiimide resins; oxazolines; and combinations thereof.

[0323] Non-limiting examples of phenolic resins are those formed by the reaction of phenol with an aldehyde or a ketone, such as the reaction of phenol with an aldehyde, such as the reaction of phenol with formaldehyde or acetaldehyde or even the reaction of phenol with formaldehyde. Non-limiting examples of phenol that can be used to form phenolic resins are phenol, butylphenol, xylenol, and cresol. The general preparation of phenolic resins is described in “The Chemistry and Application of Phenolic Resins or Phenoplasts”, Volume V, Part I, edited by Dr. Oldring; John Wiley and Sons / Cita Technology Limited, London, 1997. Phenolic resins belong to the resole type. “Resole type” means a resin formed in the presence of a basic (alkali) catalyst and optionally an excess of formaldehyde. Examples of suitable commercially available phenolic resins include, but are not limited to, those commercially available from Cytec Industries and sold under the trade name PHENODUR(RTM), such as PHENODUR EK-827, PHENODUR VPR1785, PHENODUR PR 515, PHENODUR PR516, PHENODUR PR 517, PHENODURPR 285, PHENODUR PR612, PHENODUR 520, PHENODUR 307, or PHENODUR PH2024; resins commercially available from Momentive and sold under the trade name BAKELITE(RTM), such as BAKELITE 6582LB, BAKELITE 6535, BAKELITE PF9989, BAKELITE PF 7295LB, BAKELITE 6736LG, BAKELITE6572LB, or BAKELITE PF6581; SFC 112 commercially available from Schenectady; DUREZ(RTM) 33356 commercially available from SHHPP; Curaphen 40-862 commercially available from Bitre; BDP2220 / DF0181 commercially available from Bitre; BURNOCK PH2891 commercially available from DIC Corporation; Askofen R9500 commercially available from AskChemicals; or a combination thereof.

[0324] Non-limiting examples of isocyanate resins include, but are not limited to, isophorone diisocyanate (IPDI), such as those sold under the trade name DESMODUR® commercially available from Covestro, e.g., DESMODUR VP-LS 2078 / 2 or DESMODUR PL 340, or those sold under the trade name VESTANAT® commercially available from Evonik, e.g., VESTANANT B 1370, VESTANAT B 118 6A or VESTANAT B 1358A; blocked aliphatic polyisocyanates based on hexamethylene diisocyanate (HDI), such as those sold under the trade name DESMODUR® commercially available from Covestro, e.g., DESMODUR BL3370 or DESMODUR BL 3175SN, those sold under the trade name DURANATE® commercially available from Asahi KASEI, e.g., DURANATE MF-K60X, those sold under the trade name TOLONATE® commercially available from Perstorp, e.g., TOLONATE D2, or those sold under the trade name TRIXENE® commercially available from Baxenden, e.g., TRIXENE-BI-7984 or TRIXENE 7981; or combinations thereof.

[0325] Non-limiting examples of aminoplast resins include those aminoplast resins formed by the reaction of triazines, such as melamine or benzoguanamine with formaldehyde. The resulting compounds can be etherified with alcohols, such as methanol, ethanol, butanol, or combinations thereof. The preparation and use of aminoplast resins are described in “The Chemistry and Applications of AminoCrosslinking Agents or Aminoplast”, Volume V, Part II, page 21 et seq., edited by Dr. Oldring; John Wiley and Sons / Cita Technology Limited, London, 1998. Examples of suitable commercially available aminoplast resins include, but are not limited to: aminoplast resins sold under the trademark MAPRENAL® commercially available from Prefere Resins, such as MAPRENAL MF980, MF 820 / 60IB or 821 / 84B; and aminoplast resins sold under the trademark CYMEL® commercially available from Allnex, such as CYMEL 303, CYMEL 651E and CYMEL 1128.

[0326] Examples of additives that can be present in the primer composition and / or the topcoat composition include, but are not limited to, colorants, plasticizers, wear-resistant particles, antioxidants, hindered amine light stabilizers, UV light absorbers and stabilizers, surfactants, flow control agents, thixotropic agents, fillers, organic cosolvents, reactive diluents, catalysts, grinding media, lubricants, waxes, and other conventional aids, suitable examples of which are defined herein with respect to the UV curable primer coating composition and / or the UV curable topcoat composition.

[0327] The primer coating composition can suitably form a protective coating after curing, i.e., it can form a coating operable to protect the substrate.

[0328] The topcoat composition can suitably form a protective coating after curing, i.e., it can form a coating operable to protect the ink layer.

[0329] The topcoat composition can be substantially transparent. The topcoat composition can be colorless.

[0330] The primer coating composition and / or the topcoat composition can be cured by any means. For example, the primer coating composition and / or the topcoat composition can be thermally curable and / or UV curable, such as thermally curable. When the primer coating composition and / or the topcoat composition is UV curable, the primer composition and / or the topcoat composition can contain a photoinitiator. The primer coating composition and / or the topcoat composition can be cured by exposure to heat. For example, the primer composition and / or the topcoat composition can be cured by heating at 130 °C to 230 °C for 1 to 15 minutes.

[0331] Each coating composition, including the UV curable coating composition as defined herein and optionally one or more additional coating compositions, can be independently applied to the substrate one or more times.

[0332] Substrate

[0333] As defined herein, a multi-layer coating system can be applied to the substrate. The substrate can be any suitable substrate. The substrate can be a package. Thus, the multi-layer coating system can be applied to the package.

[0334] The package can be a metal package. Examples of metal packages include, but are not limited to, food and / or beverage packages, components for manufacturing such packages, or one-piece spray cans and / or tubes. The food and / or beverage package can be a can. Suitable examples of cans include, but are not limited to, two-piece cans, three-piece cans, etc. Suitable examples of one-piece spray cans and / or tubes include, but are not limited to, deodorant containers and hair spray containers. The one-piece spray can and / or tube can be an aluminum one-piece spray can and / or tube.

[0335] The packaging can be used for packaging cosmetic, food products, beverages, and / or pharmaceutical products.

[0336] The packaging can contain aluminum. For example, the packaging can be an aluminum packaging. The packaging can be an aluminum one-piece spray can, an aluminum one-piece spray tube, or a flexible aluminum packaging. Such aluminum packaging is typically used for packaging personal care products, such as cosmetic and / or pharmaceutical products.

[0337] A multi-layer coating system can be applied to food and / or beverage packaging and / or one-piece spray cans and / or tubes or components for manufacturing such packaging.

[0338] A multi-layer coating system can be applied to one-piece spray cans, one-piece spray tubes, or components for manufacturing such packaging.

[0339] A multi-layer coating system can be applied to an uncoated substrate. For the avoidance of doubt, an uncoated substrate extends to a surface that has been cleaned prior to application.

[0340] The applications of various pre-treatments and coatings for packaging are well established. For example, such treatments and / or coatings can be used in the case of metal cans, where the treatment and / or coating is used to retard or inhibit corrosion, provide a decorative coating, provide ease of handling during the manufacturing process, etc. The coating can be applied to the interior of such cans to prevent contact of the contents with the metal of the container. For example, contact between the metal and food or beverage can cause corrosion of the metal container, which can then contaminate the food or beverage. This can be true when the contents of the can are acidic in nature. The coating applied to the interior of the metal can can also help prevent corrosion of the headspace of the can, which is the area between the fill line of the product and the can lid; for food products with a high salt content, corrosion in the headspace can become a problem. The coating can also be applied to the exterior of the metal can. Certain coating compositions of the present invention can be adapted for use with coiled metal blanks such as those used in the manufacture of can ends (“can end blanks”) and in the manufacture of end caps and closures (“lid / closure blanks”). Since the coatings designed for can end blanks and lid / closure blanks can be applied before the sheet is cut and stamped from the coiled metal blank, the coatings can be flexible and extensible. For example, such blanks can be coated on both sides. Thereafter, the coated metal blank is stamped. For the can end, the metal is then scored with an “easy open” opening, and then the pull tab is attached to a separately manufactured plug. The end is then attached to the can body by a seaming process. A similar procedure is carried out for the “easy open” can end. For the easy open can end, scoring substantially along the perimeter of the lid allows for easy opening or removal of the can lid, such as by means of a pull tab. For the lid and closure, the lid / closure blank can be coated, such as by roll coating, and the lid or closure is stamped from the blank; however, the lid / closure can be coated after formation. Coatings for cans that are subject to relatively stringent temperature and / or pressure requirements should also be able to resist cracking, corrosion, whitening, and / or blistering.

[0341] More specifically, a "package" is for containing another article, such as any substance for transporting from a manufacturing point to a consumer and subsequently stored by the consumer. Thus, the package will be understood as being sealed to keep its contents from spoiling before being opened by the consumer. Manufacturers typically identify the length of time that food or beverage will not spoil, which can range from several months to several years. Thus, the "package" of the present invention is distinct from a storage container or baking pan in which a consumer can make and / or store food; such containers can only maintain the freshness or integrity of food for a relatively short period of time. The package according to the present invention can be made of metal or non-metal, such as plastic or laminate, and can be in any form. Examples of suitable packages are laminated tubes. The packages coated according to the present invention can also include plastic bottles, plastic tubes, laminates, and flexible packages, such as plastic bottles, plastic tubes, laminates, and flexible packages made of PE, PP, PET, etc. Such packages can contain, for example, food, toothpaste, personal care products, etc.

[0342] Another example of a suitable package is a metal can. The term "metal can" includes any type of metal can, container, or any type of reservoir or part thereof sealed by food and / or beverage manufacturers to minimize or eliminate spoilage of the contents before such packages are opened by consumers. An example of a metal can is a food can; the term "food can" is used herein to refer to a can, container, or any type of reservoir or part thereof for containing any type of food and / or beverage. The term "metal can" specifically includes food cans and also specifically includes "can ends", which include "E-Z openings", which can be stamped from end stock and used in combination with the packaging of food and beverages. The term "metal can" also specifically includes metal lids and / or closures, such as bottle caps, screw-top lids and caps, snap-on caps, etc. of any size. Metal cans can also be used to contain other articles, including but not limited to personal care products, insecticidal sprays, spray paints, and any other compounds suitable for packaging in aerosol cans. Cans can include "two-piece cans" and "three-piece cans" as well as drawn and ironed single-piece cans; such single-piece cans are often applied to aerosol products.

[0343] The package can be a food or beverage preparation capsule, such as a capsule for preparing beverages (such as coffee or coffee-type beverages, tea, chocolate, milk (for infants or others), broth, cider, etc.). In use, such a capsule is placed into a compatible machine in which hot and / or pressurized water can pass through the capsule to contact the beverage ingredients, thereby preparing the beverage by, for example, dissolution, extraction, brewing, or other interactions.

[0344] The packaging can be general series products, such as buckets, paint cans, and / or pails. The packaging can be special products, such as metal containers or even hinged metal containers (for candies, lighter fluid, tobacco, etc.), for example, Altoid containers. For example, the packaging can be an aluminum foil container.

[0345] A multi-layer coating system can be applied to the interior and / or exterior of the packaging. A multi-layer coating system can be applied to the exterior of the packaging.

[0346] A multi-layer coating system can be applied to the "side seam stripe" of a metal can, which will be understood as the seam formed during the manufacture of a three-piece can. The multi-layer coating system can also be applied as an edge coating to the bottom of the can. The function of the edge coating is to reduce friction during the continuous manufacture and / or processing of the can to improve handling. The coating composition can also be applied to the lid and / or closure; such application can include, for example, a protective varnish applied before and / or after the formation of the lid / closure, and / or a colored enamel applied later to the lid, such as a colored enamel having a scored seam at the bottom of the lid.

[0347] The decorated can blanks can also be partially coated on the exterior with the multi-layer coating system described herein, and the decorated and coated can blanks are used to form various metal cans.

[0348] The packaging can include an integral spray can, an integral aerosol can, or plastic packaging, such as an extruded plastic tube.

[0349] The packaging can include plastic packaging.

[0350] Accordingly, the present disclosure extends to a packaging having a multi-layer coating system according to the present invention applied to at least a portion thereof, wherein the packaging is an integral spray can, an integral aerosol can, or an extruded plastic tube.

[0351] The plastic packaging can be formed of polyethylene and / or polypropylene.

[0352] The plastic packaging can be an extruded and / or injection-molded plastic tube, such as an extruded plastic tube.

[0353] The plastic packaging can be an extruded and / or injection-molded plastic tube containing polyethylene and / or polypropylene, such as an extruded plastic tube containing polyethylene and / or polypropylene.

[0354] The UV-curable primer coating composition and / or the UV-curable topcoat coating composition can be a one-component coating composition (commonly referred to as a 1K coating composition) or a multi-component coating composition, such as a two-component coating composition (commonly referred to as a 2K coating composition). This terminology is well known in the art. In a multi-component coating composition, the components are provided separately but are introduced into each other (e.g., by mixing) before application. This can be several hours before application, such as up to 24 hours before application, or up to 12 hours before application, or up to 8 hours before application, or up to 4 hours before application. In some cases, for example, the multi-components can be introduced into each other (such as by mixing) during the application process, such as in-line mixing. If the UV-curable primer coating composition and / or the UV-curable topcoat coating composition is a multi-component coating composition, such as a 2-component coating composition, one or more materials can be provided in the first component and other materials can be provided in an additional component (such as the second component). For example, an epoxy material can be provided in the first component and a photoinitiator can be provided in an additional component (such as the second component).

[0355] The multi-layer coating system can be applied to at least a portion of the package. For example, the multi-layer coating system can be applied to at least a portion of a plastic tube. For example, the multi-layer coating system can be applied to at least a portion of an integral spray can or an integral aerosol tube.

[0356] The multi-layer coating system can be applied to any suitable surface of the substrate (package). For example, the multi-layer coating system can be applied to at least a portion of the inner surface and / or the outer surface of the package. For example, the multi-layer coating system can be applied to at least a portion of the outer surface of the package.

[0357] The multi-layer coating system can be applied to the substrate before or after the substrate is formed into a package. For example, the multi-layer coating system can be applied to a flat sheet before the substrate (flat sheet) is formed into a package. For example, the multi-layer coating system can be applied to a preformed or partially formed package.

[0358] The multi-layer coating system can be applied to a preformed package.

[0359] Each layer of the multi-layer coating system can be applied to the substrate (package) by any suitable method. Methods for applying coating compositions and / or ink compositions will be known to those skilled in the art. Suitable methods include but are not limited to electrocoating, such as electrodeposition; spraying; electrostatic spraying; dip coating; roll coating; brush coating; and so on. The UV-curable primer coating composition and / or the UV-curable topcoat coating composition can be applied to the substrate (package) by lamination. For example, a film can be formed from the coating composition, and the film can then be applied thereto by laminating onto a metal substrate (package, such as a food or beverage can).

[0360] A UV curable primer coating composition and / or a UV curable topcoat coating composition can be applied to any suitable dry film thickness. The UV curable primer coating composition and / or the UV curable topcoat coating composition can be applied to a dry film thickness of 0.5 to 100 micrometers (μm), suitably 0.5 to 75 μm, such as 1 to 50 μm, such as 1 to 40 μm, such as 1 to 20 μm, such as 1 to 10 μm.

[0361] Selected definitions

[0362] Unless otherwise defined, as used herein, the term “alk” or “alky” refers to a saturated hydrocarbon group which is a straight-chain, branched-chain, cyclic or polycyclic moiety or a combination thereof and contains 1 to 20 carbon atoms, such as 1 to 10 carbon atoms, such as 1 to 8 carbon atoms, such as 1 to 6 carbon atoms, or even 1 to 4 carbon atoms. These groups can be optionally substituted with chlorine, bromine, iodine, cyano, nitro, OR 19 , OC(O)R 20 , C(O)R 21 , C(O)OR 22 , NR 23 R 24 , C(O)NR 25 R 26 , SR 27 , C(O)SR 27 , C(S)NR 25 R 26 , aryl or halo-substituted, wherein R 19 to R 27 each independently represent hydrogen, aryl or alkyl, and / or interrupted by an oxygen or sulfur atom or by a silanol group or a dialkylsiloxanyl group. Examples of such groups can be independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, pentyl, isopentyl, hexyl, cyclohexyl, 3-methylpentyl, octyl, etc. As used herein, the term “alkylene” refers to a divalent group alkyl group as defined above. For example, an alkyl group such as methyl which would be represented as –CH3 becomes a methylene –CH2- when represented as an alkylene. Other alkylene groups should be understood accordingly.

[0363] As used herein, the term “alkenyl” refers to a hydrocarbon group having, for example, up to 4 double bonds, being a straight-chain, branched-chain, cyclic or polycyclic moiety or a combination thereof and containing 2 to 18 carbon atoms, such as 2 to 10 carbon atoms, such as 2 to 8 carbon atoms, such as 2 to 6 carbon atoms, or even 2 to 4 carbon atoms. These groups can be optionally substituted with hydroxy, chlorine, bromine, iodine, cyano, nitro, OR 19 , OC(O)R 20, C(O)R 21 , C(O)OR 22 , NR 23 R 24 , C(O)NR 25 R 26 , SR 27 , C(O)SR 27 , C(S)NR 25 R 26 or aryl-substituted, wherein R 19 to R 27 each independently represents hydrogen, aryl or alkyl, and / or is interrupted by an oxygen atom or a sulfur atom or by a silanol group or a dialkylsiloxanyl group. Examples of such groups may independently be selected from alkenyl groups including vinyl, allyl, isopropenyl, pentenyl, hexenyl, heptenyl, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, 1-propenyl, 2-butenyl, 2-methyl-2-butenyl, isoprenyl, farnesyl, geranyl, geranylgeranyl, etc. As used herein, the term "alkenylene" refers to a divalent group alkenyl group as defined above. For example, an alkenyl group such as vinyl represented as -CH=CH2 becomes vinylene -CH=CH- when represented as an alkenylene group. Other alkenylene groups should be understood accordingly.

[0364] As used herein, the term "alkynyl" refers to a hydrocarbon group having, for example, up to 4 triple bonds, being a straight-chain, branched-chain, cyclic or polycyclic moiety or a combination thereof and having 2 to 18 carbon atoms, such as 2 to 10 carbon atoms, such as 2 to 8 carbon atoms, such as 2 to 6 carbon atoms, or even 2 to 4 carbon atoms. These groups may optionally be substituted by hydroxyl, chlorine, bromine, iodine, cyano, nitro, OR 19 , OC(O)R 20 , C(O)R 21 , C(O)OR 22 , NR 23 R 24 , C(O)NR 25 R 26 , SR 27 , C(O)SR 27 , C(S)NR 25 R 26 or aryl-substituted, wherein R 19 to R 27Each independently represents hydrogen, aryl or lower alkyl, and / or is interrupted by an oxygen atom, a sulfur atom, a silanol group or a dialkylsiloxy group. Examples of such groups can independently be selected from alkynyl groups including ethynyl, propynyl, propargyl, butynyl, pentynyl, hexynyl, etc. As used herein, the term "alkynylene" refers to a divalent alkynyl group as defined above. For example, an alkynyl group such as ethynyl represented as -C≡CH becomes ethynylene -C≡C- when represented as an alkynylene. Other alkynylene groups should be understood accordingly.

[0365] As used herein, the term "aryl" refers to an organic group derived from an aromatic hydrocarbon from which one hydrogen has been removed, and includes any monocyclic, bicyclic or polycyclic carbocyclic ring having at most 7 members in each ring, where the ring is aromatic. These groups can optionally be substituted by hydroxy, chloro, bromo, iodo, cyano, nitro, OR 19 、OC(O)R 20 、C(O)R 21 、C(O)OR 22 、NR 23 R 24 、C(O)NR 25 R 26 、SR 27 、C(O)SR 27 、C(S)NR 25 R 26 or aryl substitution (where R 19 to R 27 each independently represents hydrogen, aryl or lower alkyl) and / or is interrupted by an oxygen atom, a sulfur atom or by a silane or dialkylsilicon group. Examples of such groups can independently be selected from phenyl, p-tolyl, 4-methoxyphenyl, 4-(tert-butoxy)phenyl, 3-methyl-4-methoxyphenyl, 4-fluorophenyl, 4-chlorophenyl, 3-nitrophenyl, 3-aminophenyl, 3-acetamidophenyl, 4-acetamidophenyl, 2-methyl-3-acetamidophenyl, 2-methyl-3-aminophenyl, 3-methyl-4-aminophenyl, 2-amino-3-methylphenyl, 2,4-dimethyl-3-aminophenyl, 4-hydroxyphenyl, 3-methyl-4-hydroxyphenyl, 1-naphthyl, 2-naphthyl, 3-amino-1-naphthyl, 2-methyl-3-amino-1-naphthyl, 6-amino-2-naphthyl, 4,6-dimethoxy-2-naphthyl, tetrahydronaphthyl, indanyl, biphenyl, phenanthryl, anthryl or acenaphthylenyl, etc. As used herein, the term "arylene" refers to a divalent aryl group as defined above. For example, an aryl such as phenyl represented as -Ph becomes phenylene -Ph- when represented as an arylene. Other arylene groups should be understood accordingly.

[0366] To avoid ambiguity, references to alkyl, alkenyl, alkynyl, aryl or aralkyl groups in a compound group herein shall be construed accordingly. For example, the reference to alkyl in aminoalkyl or the reference to alkyl in alkoxy shall be construed as the above-mentioned alkane or alkyl group, etc.

[0367] As used herein, unless otherwise expressly specified, all numbers, such as those representing values, ranges, amounts or percentages, can be interpreted as if preceded by the word "about", even if the term does not explicitly appear. Similarly, the recitation of a numerical range by endpoints includes all integers, and in appropriate cases, fractions within the range (e.g., when referring to, for example, a plurality of elements, 1 to 5 can include 1, 2, 3, 4, and when referring to, for example, measurement results, can also include 1.5, 2, 2.75, and 3.80). The recitation of endpoints also includes the endpoint values themselves (e.g., 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

[0368] The singular encompasses the plural and vice versa. For example, although this disclosure refers to "a" crosslinking agent material, "a" thermoplastic particle, "an" epoxy compound, etc., one or more of each of these can be used, as well as any other components. As used herein, the term "polymer" refers to both oligomers and homopolymers and copolymers, and the prefix "poly" refers to two or more. The inclusion of terms such as "such as" and "like" means inclusion including but not limited to.

[0369] As used herein, the terms "comprising", "comprises" and "comprised of" are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, unrecited members, elements or method steps. Additionally, although this disclosure has been described from the perspective of "comprising", the coating compositions described in detail herein can also be described as "consisting essentially of" or "consisting of".

[0370] As used herein, the term "and / or" when used in a list of two or more items means that any one of the listed items can be used alone, or any combination of two or more of the listed items can be used. For example, if the list is described as including groups A, B and / or C, the list can include A alone; B alone; C alone; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B and C.

[0371] The present disclosure may be according to any one of the following numbered aspects:

[0372] 1. A multi-layer coating system comprising: i) a primer coating derived from a UV-curable primer coating composition comprising: a) an epoxy material; b) a polyol material and / or a diketone functional material having a hydroxyl value (OHV) of at least 35 mg KOH / g; and c) a photoinitiator; and ii) an ink layer derived from an ink composition.

[0373] 2. The multi-layer coating system according to aspect 1, wherein the ink layer is disposed directly on the primer coating.

[0374] 3. The multi-layer coating system according to any one of aspects 1 or 2, wherein the ink composition is digitally printed.

[0375] 4. The multi-layer coating system according to any one of aspects 1 to 3, wherein the UV-curable primer coating composition has a solids content of at least 95% by weight based on the total weight of the composition.

[0376] 5. The multi-layer coating system according to any one of aspects 1 to 4, wherein the UV-curable primer coating composition comprises a polyol material in an amount of at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight, based on the total solids weight of the composition.

[0377] 6. The multi-layer coating system according to any one of aspects 1 to 5, wherein the UV-curable primer coating composition comprises a diketone functional material, such as an acetoacetate functional material, in an amount of at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight, based on the total solids weight of the composition.

[0378] 7. The multi-layer coating system according to any one of aspects 1 to 6, wherein the epoxy material comprises an alicyclic epoxy resin.

[0379] 8. The multi-layer coating system according to any one of aspects 1 to 7, wherein the UV-curable primer coating composition comprises 55 to 85% by weight of an epoxy material based on the total solids weight of the composition.

[0380] 9. The multi-layer coating system according to any one of aspects 1 to 8, wherein the photoinitiator comprises a cationic photoinitiator.

[0381] 10. The multi-layer coating system according to any one of aspects 1 to 9, wherein the UV-curable primer coating composition is substantially free of polytetrafluoroethylene (PTFE).

[0382] 11. The multi-layer coating system according to any one of aspects 1 to 10, wherein the polyol material has a hydroxyl value (OHV) of at least 50 mg KOH / g, such as at least 100 mg KOH / g.

[0383] 12. The multi-layer coating system according to any one of aspects 1 to 11, wherein the polyol material has an acid value (AV) of up to 10 mg KOH / g.

[0384] 13. The multi-layer coating system according to any one of aspects 1 to 12, wherein the polyol material has a number average molecular weight (Mn) of up to 5,000 Da.

[0385] 14. The multi-layer coating system according to any one of aspects 1 to 13, wherein the UV-curable primer coating composition further comprises a polyester material having a hydroxyl value (OHV) of up to 45 mg KOH / g, optionally wherein the polyester material is present in the UV-curable primer coating composition in an amount of 6 to 20% by weight based on the total solid weight of the composition.

[0386] 15. The multi-layer coating system according to any one of aspects 1 to 14, wherein the UV-curable primer coating composition comprises 1 to 5% by weight of a photoinitiator based on the total solid weight of the composition.

[0387] 16. A package having at least a portion thereof coated with the multi-layer coating system according to any one of aspects 1 to 15.

[0388] 17. A plastic package having at least a portion thereof coated with the multi-layer coating system according to any one of aspects 1 to 15.

[0389] 18. The package according to aspect 17, wherein the package comprises polyethylene and / or polypropylene.

[0390] 19. The package according to any one of aspects 17 or 18, wherein the package comprises an extruded and / or injection molded plastic tube, such as an extruded plastic tube.

[0391] 20. A multi-layer coating system comprising: i) a primer coating derived from the UV-curable primer coating composition according to any one of aspects 1 to 15; ii) an ink layer derived from an ink composition; and iii) a topcoat coating derived from a topcoat coating composition.

[0392] 21. The multi-layer coating system according to aspect 20, wherein the ink layer is disposed directly on the primer coating.

[0393] 22. The multi-layer coating system according to any one of aspects 20 or 21, wherein the top coating is directly provided on the ink layer.

[0394] 23. The multi-layer coating system according to any one of aspects 20 to 22, wherein the top coating composition is thermosettable.

[0395] 24. The multi-layer coating system according to any one of aspects 20 to 23, wherein the top coating composition comprises one or more components selected from the group consisting of: resin binders, solvents, crosslinking agent materials, and additives.

[0396] 25. The multi-layer coating system according to any one of aspects 20 to 24, wherein the top coating composition is solvent-based.

[0397] 26. The multi-layer coating system according to any one of aspects 24 or 25, wherein the top coating composition comprises one or more resins selected from the group consisting of polyester resins, acrylic resins, polyvinyl chloride (PVC) resins, alkyd resins, polyurethane resins, polysiloxane resins, epoxy resins, or combinations thereof.

[0398] 27. The multi-layer coating system according to any one of aspects 24 to 26, wherein the top coating composition comprises one or more crosslinking agent materials selected from the group consisting of: phenolic resins (or phenol formaldehyde resins); aminoplast resins (or triazine formaldehyde resins); amino resins; epoxy resins; epoxy analog resins, such as those based on bisphenols and other bisphenol A (BPA) alternatives; isocyanate resins, isocyanurate resins, such as triglycidyl isocyanurate; hydroxy (alkyl) amide resins, such as β-hydroxy (alkyl) amide resins; hydroxy (alkyl) urea resins; carbodiimide resins, such as polycarbodiimide resins; oxazolines; and combinations thereof.

[0399] 27. The multi-layer coating system according to aspect 27, wherein the crosslinking agent material comprises phenolic resin, aminoplast resin, isocyanate resin, isocyanurate resin, or combinations thereof.

[0400] 28. A package having at least a portion thereof coated with the multi-layer coating system according to any one of aspects 20 to 27.

[0401] 29. A plastic package having at least a portion thereof coated with the multi-layer coating system according to any one of aspects 20 to 27.

[0402] 30. The package according to aspect 29, wherein the package comprises polyethylene and / or polypropylene.

[0403] 31. The package according to any one of aspects 29 or 30, wherein the package comprises an extruded and / or injection molded plastic tube, such as an extruded plastic tube.

[0404] 32. A multi-layer coating system for an aluminum package, the multi-layer coating system comprising: i) an ink layer derived from an ink composition; and ii) an outer coating derived from a UV-curable outer coating composition, the UV-curable outer coating composition comprising: a2) an epoxy material; b2) a polyol material and / or a diketone functional material; and c2) a photoinitiator.

[0405] 33. The multi-layer coating system according to aspect 32, wherein the outer coating is directly disposed on the ink layer.

[0406] 34. The multi-layer coating system according to any one of aspects 32 or 33, wherein the ink composition is digitally printed.

[0407] 35. The multi-layer coating system according to any one of aspects 32 to 34, wherein the UV-curable outer coating composition has a solids content of at least 95% by weight based on the total weight of the composition.

[0408] 36. The multi-layer coating system according to any one of aspects 32 to 35, wherein the UV-curable outer coating composition comprises a polyol material in an amount of at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight, based on the total solids weight of the composition.

[0409] 37. The multi-layer coating system according to any one of aspects 32 to 36, wherein the UV-curable outer coating composition comprises a diketone functional material, such as an acetoacetate functional material, in an amount of at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight, based on the total solids weight of the composition.

[0410] 38. The multi-layer coating system according to any one of aspects 32 to 37, wherein the epoxy material comprises an alicyclic epoxy resin.

[0411] 39. The multi-layer coating system according to any one of aspects 32 to 38, wherein the UV-curable outer coating composition comprises 55 to 85% by weight of an epoxy material based on the total solids weight of the composition.

[0412] 40. The multi-layer coating system according to any one of aspects 32 to 39, wherein the photoinitiator comprises a cationic photoinitiator.

[0413] 41. The multi-layer coating system according to any one of aspects 32 to 40, wherein the outer coating composition comprises a reactive diluent, such as a reactive diluent containing oxetane groups.

[0414] 42. The multi-layer coating system according to any one of aspects 32 to 41, wherein the UV-curable topcoat coating composition comprises 1 to 10% by weight of a photoinitiator based on the total solids weight of the composition.

[0415] 43. The multi-layer coating system according to any one of aspects 32 to 42, wherein the UV-curable topcoat coating composition is substantially free of polytetrafluoroethylene (PTFE).

[0416] 44. The multi-layer coating system according to any one of aspects 32 to 43, wherein the polyol material has a hydroxyl value (OHV) of at least 25 mg KOH / g.

[0417] 45. The multi-layer coating system according to any one of aspects 32 to 44, wherein the UV-curable topcoat coating composition comprises wax, such as wax comprising micronized wax and / or micronized polysaccharide.

[0418] 46. The multi-layer coating system according to any one of aspects 32 to 45, wherein the UV-curable topcoat coating composition further comprises a (meth)acrylate functional material.

[0419] 47. The multi-layer coating system according to aspect 46, wherein the UV-curable topcoat coating composition further comprises a radical initiator.

[0420] 48. The multi-layer coating system according to any one of aspects 32 to 47, wherein the aluminum package is an integral spray can and / or tube.

[0421] 49. The multi-layer coating system according to any one of aspects 32 to 48, wherein the aluminum package is for packaging cosmetic products, food products, beverage and / or pharmaceutical products, such as for packaging cosmetic products and / or pharmaceutical products.

[0422] 50. A multi-layer coating system for an aluminum package, the multi-layer coating system comprising: i) a primer layer derived from a primer coating composition, ii) an ink layer derived from an ink composition; and ii) a topcoat layer derived from the UV-curable topcoat coating composition according to any one of aspects 32 to 49.

[0423] 51. The multi-layer coating system according to aspect 50, wherein the ink layer is directly disposed on the primer coating.

[0424] 52. The multi-layer coating system according to any one of aspects 50 or 51, wherein the topcoat layer is directly disposed on the ink layer.

[0425] 53. The multi-layer coating system according to any one of aspects 50 to 52, wherein the ink composition is digitally printed.

[0426] 54. The multi-layer coating system according to any one of aspects 50 to 53, wherein the primer coating composition is thermally cured.

[0427] 55. The multi-layer coating system according to any one of aspects 50 to 54, wherein the primer coating composition comprises one or more components selected from resin binders, solvents, crosslinker materials, and additives.

[0428] 56. The multi-layer coating system according to any one of aspects 50 to 55, wherein the primer coating composition is solvent-based.

[0429] 57. The multi-layer coating system according to any one of aspects 55 or 56, wherein the primer coating composition comprises one or more resins selected from polyester resins, acrylic resins, polyvinyl chloride (PVC) resins, alkyd resins, polyurethane resins, polysiloxane resins, epoxy resins, or combinations thereof.

[0430] 58. The multi-layer coating system according to any one of aspects 55 to 57, wherein the primer coating composition comprises one or more crosslinker materials selected from the following: phenolic resins (or phenol-formaldehyde resins); aminoplast resins (or triazine formaldehyde resins); amino resins; epoxy resins; epoxy mimic resins, such as those based on bisphenols and other bisphenol A (BPA) alternatives; isocyanate resins, isocyanurate resins, such as triglycidyl isocyanurate; hydroxy (alkyl) amide resins, such as β-hydroxy (alkyl) amide resins; hydroxy (alkyl) urea resins; carbodiimide resins, such as polycarbodiimide resins; oxazolines; and combinations thereof.

[0431] 59. The multi-layer coating system according to aspect 58, wherein the crosslinker material comprises a phenolic resin, an aminoplast resin, an isocyanate resin, an isocyanurate resin, or a combination thereof.

[0432] 60. The multi-layer coating system according to any one of aspects 50 to 59, wherein the aluminum package is an integral spray can and / or tube.

[0433] 61. The multi-layer coating system according to any one of aspects 50 to 59, wherein the aluminum package is used for packaging cosmetic products, food products, beverages, and / or pharmaceutical products, for example, for packaging cosmetic products and / or pharmaceutical products.

[0434] 62. An aluminum package, on at least a portion of which is coated with the multi-layer coating system according to any one of aspects 32 to 49.

[0435] 63. An aluminum packaging, on at least a part of which a multilayer coating system according to any one of aspects 50 to 61 is applied.

[0436] 64. The aluminum packaging according to any one of aspects 62 or 63, wherein the packaging is for packaging cosmetic products, food products, beverages, and / or pharmaceutical products, for example for packaging cosmetic products and / or pharmaceutical products.

[0437] 65. The aluminum packaging according to any one of aspects 62 to 64, wherein the aluminum packaging is an integral spray can and / or tube.

[0438] 66. A method for producing a packaging, the method comprising the steps of: I) applying a UV-curable primer coating composition to at least a part of the packaging, the UV-curable primer coating composition comprising: a) an epoxy material; b) a polyol material and / or a diketone functional material having a hydroxyl value (OHV) of at least 35 mg KOH / g; and c) a photoinitiator; II) curing the UV-curable primer coating composition to form a cured primer coating; III) applying an ink composition on at least a part of the primer coating; and IV) curing the ink composition to form an ink layer.

[0439] 67. The method according to aspect 66, wherein the ink composition is applied by digital printing.

[0440] 68. The method according to any one of aspects 66 or 67, wherein the UV-curable primer coating composition has a solids content of at least 95% by weight based on the total weight of the composition.

[0441] 69. The method according to any one of aspects 66 to 68, wherein the UV-curable primer coating composition comprises a polyol material in an amount of at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight, based on the total solids weight of the composition.

[0442] 70. The method according to any one of aspects 66 to 69, wherein the UV-curable primer coating composition comprises a diketone functional material, such as an acetoacetate functional material, in an amount of at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight, based on the total solids weight of the composition.

[0443] 71. The method according to any one of aspects 66 to 70, wherein the epoxy material comprises an alicyclic epoxy resin.

[0444] 72. The method according to any one of aspects 66 to 71, wherein the UV-curable primer coating composition comprises 55 to 85% by weight of an epoxy material based on the total solids weight of the composition.

[0445] 73. The method according to any one of aspects 66 to 72, wherein the photoinitiator comprises a cationic photoinitiator.

[0446] 74. The method according to any one of aspects 66 to 73, wherein the UV-curable primer coating composition is substantially free of polytetrafluoroethylene (PTFE).

[0447] 75. The method according to any one of aspects 66 to 74, wherein the polyol material has a hydroxyl value (OHV) of at least 50 mg KOH / g, such as at least 100 mg KOH / g.

[0448] 76. The method according to any one of aspects 66 to 75, wherein the polyol material has an acid value (AV) of up to 10 mg KOH / g.

[0449] 77. The method according to any one of aspects 66 to 76, wherein the polyol material has a number average molecular weight (Mn) of up to 5,000 Da.

[0450] 78. The method according to any one of aspects 66 to 77, wherein the UV-curable primer coating composition further comprises a polyester material having a hydroxyl value (OHV) of less than 35 mg KOH / g, such as up to 30 mg KOH / g, optionally wherein the polyester material is present in the UV-curable primer coating composition in an amount of 6 to 20% by weight based on the total solid weight of the composition.

[0451] 79. The method according to any one of aspects 66 to 78, wherein the UV-curable primer coating composition comprises 1 to 5% by weight of a photoinitiator based on the total solid weight of the composition.

[0452] 80. The method according to any one of aspects 66 to 79, further comprising the steps of: V) applying a topcoat coating composition over at least a portion of the ink layer; and VI) curing the topcoat coating composition to form a cured topcoat layer.

[0453] 81. The method according to aspect 80, wherein the topcoat coating composition is thermally curable.

[0454] 82. The method according to any one of aspects 80 or 81, wherein the topcoat coating composition comprises one or more components selected from resin binders, solvents, crosslinking agent materials, and additives.

[0455] 83. The method according to any one of aspects 80 to 82, wherein the topcoat coating composition is solvent-based.

[0456] 84. The method according to any one of aspects 82 or 83, wherein the topcoat coating composition comprises one or more resins selected from polyester resins, acrylic resins, polyvinyl chloride (PVC) resins, alkyd resins, polyurethane resins, polysiloxane resins, epoxy resins, or combinations thereof.

[0457] 85. The method according to any one of aspects 82 to 84, wherein the topcoat coating composition comprises one or more crosslinker materials selected from: phenolic resins (or phenol-formaldehyde resins); aminoplast resins (or triazine formaldehyde resins); amino resins; epoxy resins; epoxy analog resins, such as those based on bisphenols and other bisphenol A (BPA) alternatives; isocyanate resins, isocyanurate resins, such as triglycidyl isocyanurate; hydroxy(alkyl)amide resins, such as β-hydroxy(alkyl)amide resins; hydroxy(alkyl)urea resins; carbodiimide resins, such as polycarbodiimide resins; oxazolines; and combinations thereof.

[0458] 86. The method system according to aspect 85, wherein the crosslinker material comprises a phenolic resin, an aminoplast resin, an isocyanate resin, an isocyanurate resin, or a combination thereof.

[0459] 87. The method according to any one of aspects 66 to 86, wherein the packaging is plastic packaging.

[0460] 88. The method according to aspect 87, wherein the plastic packaging comprises polyethylene and / or polypropylene.

[0461] 89. The method according to any one of aspects 87 or 88, wherein the plastic packaging comprises an extruded and / or injection-molded plastic tube, such as an extruded plastic tube.

[0462] 90. A method of producing an aluminum package such as an integral spray can and / or tube, the method comprising the steps of: III) applying an ink composition to at least a portion of the aluminum package; IV) curing the ink composition to form an ink layer; V) applying a UV-curable topcoat coating composition to at least a portion of the ink layer, the UV-curable topcoat coating composition comprising: a) an epoxy material; b) a polyol material and / or a diketone functional material; and c) a photoinitiator; and VI) curing the topcoat coating composition to form a cured topcoat layer.

[0463] 91. The method according to aspect 90, wherein the ink composition is applied by digital printing.

[0464] 92. The method according to any one of aspects 90 or 91, wherein the UV-curable topcoat coating composition has a solids content of at least 95 wt% based on the total weight of the composition.

[0465] 93. The method according to any one of aspects 90 to 92, wherein the UV curable topcoat coating composition comprises a polyol material in an amount of at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight, based on the total solids weight of the composition.

[0466] 94. The method according to any one of aspects 90 to 93, wherein the UV curable topcoat coating composition comprises a diketone functional material, such as an acetoacetate functional material, in an amount of at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight, based on the total solids weight of the composition.

[0467] 95. The method according to any one of aspects 90 to 94, wherein the epoxy material comprises an alicyclic epoxy resin.

[0468] 96. The method according to any one of aspects 90 to 95, wherein the UV curable topcoat coating composition comprises 55 to 85% by weight of an epoxy material based on the total solids weight of the composition.

[0469] 97. The method according to any one of aspects 90 to 96, wherein the photoinitiator comprises a cationic photoinitiator.

[0470] 98. The method according to any one of aspects 90 to 97, wherein the topcoat coating composition comprises a reactive diluent, such as a reactive diluent containing oxetane groups.

[0471] 99. The method according to any one of aspects 90 to 98, wherein the UV curable topcoat coating composition comprises 1 to 10% by weight of a photoinitiator based on the total solids weight of the composition.

[0472] 100. The method according to any one of aspects 90 to 99, wherein the UV curable topcoat coating composition is substantially free of polytetrafluoroethylene (PTFE).

[0473] 101. The method according to any one of aspects 90 to 100, wherein the polyol material has a hydroxyl value (OHV) of at least 25 mg KOH / g.

[0474] 102. The method according to any one of aspects 90 to 101, wherein the UV curable topcoat coating composition comprises wax, such as wax containing micronized wax and / or micronized polysaccharide.

[0475] 103. The method according to any one of aspects 99 to 102, wherein the UV curable topcoat coating composition further comprises an acrylic material.

[0476] 104. The method according to aspect 103, wherein the UV curable topcoat coating composition further comprises a radical initiator.

[0477] 105. According to the method of any one of aspects 90 to 104, it further comprises the following steps: I) applying a primer coating composition to at least a part of the aluminum package; and II) curing the primer coating composition to form a cured primer coating.

[0478] 106. According to the method of aspect 105, wherein the ink layer is directly disposed on the primer coating.

[0479] 107. According to the method of any one of aspects 106 or 106, wherein the primer layer is directly disposed on the aluminum package.

[0480] 108. According to the method of any one of aspects 105 to 107, wherein the primer coating composition is thermally cured.

[0481] 109. According to the method of any one of aspects 105 to 108, wherein the primer coating composition comprises one or more components selected from a resin binder, a solvent, a crosslinking agent material, and an additive.

[0482] 110. According to the method of any one of aspects 105 to 109, wherein the primer coating composition is solvent-based.

[0483] 111. According to the method of any one of aspects 109 or 110, wherein the primer coating composition comprises one or more resins selected from a polyester resin, an acrylic resin, a polyvinyl chloride (PVC) resin, an alkyd resin, a polyurethane resin, a polysiloxane resin, an epoxy resin, or a combination thereof.

[0484] 112. According to the method of any one of aspects 109 to 111, wherein the primer coating composition comprises one or more crosslinking agent materials selected from the following: phenolic resin (or phenol-formaldehyde resin); aminoplast resin (or triazine formaldehyde resin); amino resin; epoxy resin; epoxy mimic resin, such as those based on bisphenol and other bisphenol A (BPA) alternatives; isocyanate resin, isocyanurate resin, such as tris(glycidyl isocyanurate); hydroxy(alkyl)amide resin, such as β-hydroxy(alkyl)amide resin; hydroxy(alkyl)urea resin; carbodiimide resin, such as polycarbodiimide resin; oxazoline; and combinations thereof.

[0485] 113. According to the method of aspect 112, wherein the crosslinking agent material comprises a phenolic resin, an aminoplast resin, an isocyanate resin, an isocyanurate resin, or a combination thereof.

[0486] 114. According to the method of any one of aspects 90 to 113, wherein the aluminum package is an integral spray can and / or tube.

[0487] 115. The method according to any one of aspects 90 to 114, wherein the aluminum packaging is used for packaging cosmetic products, food products, beverages, and / or pharmaceutical products, such as for packaging cosmetic products and / or pharmaceutical products.

[0488] 116. A UV - curable primer coating composition, the primer coating composition comprising: a) an epoxy material; b) a polyol material having a hydroxyl value (OHV) of at least 50 mg KOH / g, and / or a diketone - functional material; and c) a photoinitiator; wherein when present, the polyol material is present in the primer coating composition in an amount of at least 2% by weight based on the total solid weight of the primer coating composition; wherein when present, the diketone - functional material is present in the primer coating composition in an amount of at least 2% by weight based on the total solid weight of the primer coating composition; and wherein the solid content of the primer coating composition is at least 95% by weight based on the total weight of the primer coating composition.

[0489] 117. A coating composition system, the coating composition system comprising: i) a UV - curable primer coating composition operably disposed on a substrate, the primer coating composition comprising: a) an epoxy material; b) a polyol material having a hydroxyl value (OHV) of at least 50 mg KOH / g, and / or a diketone - functional material; and c) a photoinitiator; wherein when present, the polyol material is present in the primer coating composition in an amount of at least 2% by weight based on the total solid weight of the primer coating composition; wherein when present, the diketone - functional material is present in the primer coating composition in an amount of at least 2% by weight based on the total solid weight of the primer coating composition; and wherein the solid content of the primer coating composition is at least 95% by weight of the total weight of the primer coating composition; ii) an ink operably disposed on at least a portion of the primer coating composition or a primer coating derived therefrom; and iii) optionally, an over - coating composition operably disposed on at least a portion of the ink or an ink layer derived therefrom.

[0490] 118. The UV - curable primer coating composition according to aspect 116 or the coating composition system according to aspect 117, wherein the primer coating composition further comprises a polyester material having a hydroxyl value (OHV) of up to 45 mg KOH / g.

[0491] 119. The UV - curable primer coating composition according to any one of aspects 116 or 118 or the coating composition system according to any one of aspects 117 or 118, wherein the polyol material has a hydroxyl value (OHV) of at least 100 mg KOH / g.

[0492] 120. The UV-curable primer coating composition according to any one of aspects 116, 118, or 119, or the coating composition system according to any one of aspects 117 to 119, wherein the polyol material has an acid value (AV) of up to 10 mg KOH / g.

[0493] 121. The UV-curable primer coating composition according to any one of aspects 116 or 118 to 120, or the coating composition system according to any one of aspects 117 to 120, wherein the diketone-functional material includes an acetoacetate-functional material.

[0494] 122. The UV-curable primer coating composition according to any one of aspects 116 or 118 to 121, or the coating composition system according to any one of aspects 117 to 121, wherein the primer coating composition comprises a polyol material; and wherein the primer coating composition comprises at least 5 wt% of the polyol material based on the total solid weight of the primer coating composition, such as 5 to 30 wt% of the polyol material based on the total solid weight of the primer coating composition.

[0495] 123. The UV-curable primer coating composition according to any one of aspects 116 or 118 to 122, or the coating composition system according to any one of aspects 117 to 122, wherein the primer coating composition comprises a diketone-functional material; and wherein the primer coating composition comprises at least 5 wt% of the diketone-functional material based on the total solid weight of the primer coating composition, such as 5 to 30 wt% of the diketone-functional material based on the total solid weight of the primer coating composition.

[0496] 124. The UV-curable primer coating composition according to any one of aspects 116 or 118 to 123, or the coating composition system according to any one of aspects 117 to 123, wherein the epoxy material includes an alicyclic epoxy resin.

[0497] 125. The UV-curable primer coating composition according to any one of aspects 116 or 118 to 124, or the coating composition system according to any one of aspects 117 to 124, wherein the photoinitiator includes a cationic photoinitiator.

[0498] 126. The UV-curable primer coating composition according to any one of aspects 116 or 118 to 125, or the coating composition system according to any one of aspects 117 to 125, wherein the primer coating composition comprises 55 to 85 wt% of the epoxy material based on the total solid weight of the primer coating composition.

[0499] 127. The UV - curable primer coating composition according to any one of aspects 116 or 118 to 126, or the coating composition system according to any one of aspects 117 to 126, wherein the coating composition comprises 5 to 20% by weight of a polyester material based on the total solids weight of the primer coating composition.

[0500] 128. The UV - curable primer coating composition according to any one of aspects 116 or 118 to 127, or the coating composition system according to any one of aspects 117 to 127, wherein the coating composition comprises 1 to 5% by weight of a photoinitiator based on the total solids weight of the primer coating composition.

[0501] 129. The UV - curable primer coating composition according to any one of aspects 116 or 118 to 128, or the coating composition system according to any one of aspects 117 to 128, wherein the polyol material has a number - average molecular weight (Mn) of up to 5,000 Da.

[0502] 130. The UV - curable primer coating composition according to any one of aspects 116 or 118 to 129, or the coating composition system according to any one of aspects 117 to 129, wherein the primer coating composition and / or the coating composition system is substantially free of polytetrafluoroethylene (PTFE).

[0503] 131. A plastic package having a primer coating on at least a portion thereof, the primer coating being derived from the UV - curable primer coating composition according to any one of aspects 116 or 118 to 130.

[0504] 132. A plastic package having a coating system on at least a portion thereof, the coating system comprising: i) a primer coating layer derived from the UV - curable primer coating composition according to any one of aspects 116 or 118 to 130; ii) an ink layer disposed on at least a portion of the primer coating layer, the ink layer being derived from an ink; and iii) optionally, a top - coat layer disposed on at least a portion of the ink layer, the top - coat layer being derived from a top - coat coating composition.

[0505] 133. A method for producing a coated plastic packaging, the method comprising the steps of: I) applying a primer coating composition according to any one of aspects 116 or 118 to 130 to at least a part of the plastic packaging; II) curing the primer coating composition to form a cured primer coating; III) digitally printing an ink on at least a part of the primer coating; IV) curing the ink to form an ink layer; V) optionally, applying an overcoat coating composition on at least a part of the ink layer; and VI) curing the overcoat coating composition, if present, to form a cured overcoat coating.

[0506] 134. The plastic packaging according to any one of aspects 131 or 132 or the method according to aspect 133, wherein the packaging comprises polyethylene and / or polypropylene.

[0507] 135. The plastic packaging according to any one of aspects 131, 132 or 134 or the method according to any one of aspects 133 or 134, wherein the packaging is an extruded and / or injection molded plastic pipe.

[0508] 136. The plastic packaging according to any one of aspects 131, 132, 134 or 135 or the method according to any one of aspects 133 to 135, wherein the primer coating and / or the coating system is provided on at least a part of the outer surface of the packaging.

[0509] 137. The plastic packaging according to any one of aspects 131, 132 or 134 to 136 or the method according to any one of aspects 133 to 136, wherein the primer coating composition is applied to a thickness of 1 to 10 μm.

[0510] All features contained herein can be combined in any combination with any of the above aspects.

[0511] For a better understanding of the present disclosure and to illustrate how embodiments of the present disclosure can be implemented, reference will now be made, by way of example, to the following examples.

[0512] Examples

[0513] Primer coating examples 1 to 7

[0514] Prepare UV curable primer examples 1 to 7 according to the formulations in Table 1, wherein:

[0515] · UviCure S105 is a difunctional alicyclic epoxy resin, 7-oxabicyclo[4.1.0]hept-3-ylmethyl 7-oxabicyclo[4.1.0]heptane-3-carboxylate, available from Lambson;

[0516] · Tego AddBond LTW is a polyester resin with an OHV of 20 to 30 mg KOH / g and is available from Evonik;

[0517] · D.E.R. 731 is a reactive diluent based on 1,4 - butanediol diglycidyl ether and is available from Olin Epoxy; · Plastomoll DOA is bis(2 - ethylhexyl) adipate, a plasticizer available from BASF;

[0518] · BYK - 310 is a silicone additive commercially available from Altana;

[0519] · BYK - 141 is a silicone additive (defoamer) commercially available from Altana;

[0520] · Speedcure 976 is a cationic photoinitiator of the sulfonium hexafluoroantimonate family available from Lambson;

[0521] · Desmophen 1380 is a trifunctional polypropylene ether polyol with an OHV of 385 mg KOH / g and an AV of 0.5 mg KOH / g and is available from Covestro;

[0522] · Desmophen 670 is a slightly branched hydroxyl - terminated polyester available from Covestro;

[0523] · Capa 3031 is a very low MW trifunctional caprolactone polyol with an OHV of 560 mg KOH / g, an AV of < 1 mg KOH / g and an MW of 300 g / mol and is available from Perstorp;

[0524] · K - flex 7301 is an acetoacetate - functional reactive diluent available from King Industries;

[0525] · Polyol 4290 is a caprolactone polyol tetrol with an OHV of 218 mg KOH / g, an AV of < 1 mg KOH / g and an MW of 1,000 g / mol and is available from Perstorp;

[0526] · Boltorn H 2004 is a fatty acid - modified dendrimer with 6 terminal hydroxyl groups, having an OHV of 105 - 135 mg KOH / g, an AV of < 7 mg KOH / g and an MW of 3,200 g / mol and is available from Perstorp; and

[0527] mole and is available from Perstorp; and

[0528] ·Capa 2054 is a low MW linear polyester diol derived from caprolactone with an OHV of 204 mg KOH / g, an AV of < 0.25 mg KOH / g, and an MW of 550 g / mol, available from Perstorp; unless otherwise noted, all amounts are provided in parts by weight (pbw).

[0529] Comparative primer coating examples 1 and 2

[0530] UV curable comparative primer coat Examples 1 and 2 were prepared according to the formulations in Table 1. Unless otherwise noted, all amounts are provided in parts by weight (pbw).

[0531] Primer coating examples 8 to 7

[0532] UV curable primer coat Examples 1 to 7 were prepared according to the formulations in Table 2, where:

[0533] ·Lanco TF 1780EFC is a micronized PTFE modified polyethylene wax available from Lubrizol Corporation; ·Capa 4104 is a polycaprolactone polyol tetrol with an OHV of 218 mg KOH / g, an AV of < 0.1 mg KOH / g, and an MW of 1,000 g / mol, available from Perstorp;

[0534] ·K-flex XM B301 is an acetoacetate functional reactive diluent with an OHV of 190 mg KOH / g, available from King Industries;

[0535] ·K-flex 337BA is an aliphatic saturated polyester diol with an OHV of 220 mg KOH / g, available from King Industries; and

[0536] ·Nebores VAGH is a vinyl resin available from Safic-Alcan.

[0537] The remaining components are as described above with respect to Table 1 (and primer coat Examples 1 to 8 and / or comparative primer coat Examples 1 to 2).

[0538] Unless otherwise noted, all amounts are provided in parts by weight (pbw).

[0539] Comparative primer coating examples 3 to 5

[0540] UV curable comparative primer coat Examples 3 to 5 were prepared according to the formulations in Table 2. Unless otherwise noted, all amounts are provided in parts by weight (pbw).

[0541] Table 1 - Formulations of Primer Coat Examples 1 to 7 and Comparative Primer Coat Examples 1 and 2

[0542]

[0543] Table 2 - Formulations of Primer Coat Examples 8 to 14 and Comparative Primer Coat Examples 3 to 5

[0544]

[0545] The primer coat coating compositions were tested according to the following method:

[0546] Substrate Preparation: The LDPE substrate in the form of a tube was cleaned with methyl ethyl ketone (MEK), left for 2 minutes under ambient conditions, and then flame treated. Then, the coating composition was applied to the substrate using a bar coater. Then, according to the manufacturer's instructions, the coating composition was cured under Uviterno Lab BD - 5025 UV light. Five coated substrates were prepared for each sample. Once cured, a 5 cm x 5 cm piece of the coated substrate was cut for evaluation.

[0547] Flexure Test: The flexibility of the coating was tested as follows. The coated substrate was placed in a Sheen manual cupping test device with the coated side facing up. The Sheen manual cupping test device will be familiar to those skilled in the art and is a revolutionary device for testing the resistivity of coatings at various stages of deformation. The test panel was deformed by rotating the applied manual force. The substrate was deformed in 1 - mm increments by applying an appropriate number of rotations to produce the deformation in mm applied by the device (where 1 rotation corresponds to 1 mm of deformation). Thus, for deformations of 2, 3, 4, 5, 6, etc. mm, 2, 3, 4, 5, 6, etc. rotations were applied respectively. The formation of cracks in the coating between rotations was evaluated by applying graphite to the deformed area and visually assessing under a microscope. The mm of deformation before cracking occurred was recorded.

[0548] The results are shown in Table 3.

[0549] Table 3 - Results

[0550]

[0551] The results show that the UV - curable primer coat coating composition of the present invention, i.e., the UV - curable primer coat coating composition according to the present disclosure, has improved flexibility compared to the comparative examples. For example, the results show that the use of polyol materials and / or diketone functional materials has improved flexibility compared to the comparative examples (i.e., compared to coating compositions that do not contain such materials). Therefore, the UV - curable primer coat coating composition of the present invention is suitable for use as a primer coat for digital printing on plastic substrates.

[0552] Topcoat coating example 1

[0553] Example 1 of the UV-curable overcoat was prepared according to the formulation in Table 4, where:

[0554] · Curalite OX is a 3-ethyl-3-oxetanemethanol reactive diluent available from Perstorp;

[0555] · Speedcure 992 is a cationic photoinitiator of the sulfonium hexafluorophosphate family available from Lambson;

[0556] · BYK-330 is a silicone-containing surface additive available from Altana; and

[0557] · MP 22XF is a micronized synthetic wax available from Micro Powders, Inc.

[0558] The remaining components are as described above with respect to Table 1 (and primer coat examples 1 to 8 and / or comparative primer coat examples 1 to 2).

[0559] Unless otherwise stated, all amounts are provided in parts by weight (pbw).

[0560] Table 4 - Formulation of Overcoat Example 1

[0561] Components Topcoat coating example 1 UviCure S105 63.45 Curalite OX 9.4 Speedcure 992 4.23 BYK-330 1.29 Capa 3031 20.45 MP 22XF 1.18 Total 100

[0562] Comparative topcoat coating example 1

[0563] Comparative overcoat example 1 is PPG4619-805 / A, a solvent-based topcoat varnish commercially available from PPG.

[0564] The overcoat coating compositions were tested according to the following method:

[0565] Substrate preparation: An aluminum panel (untreated) was coated with PPG4666-002A (a solvent-based white primer coat commercially available from PPG) using a doctor blade to achieve an average film thickness of 15 microns. The panel was placed in an oven and the primer coat was thermally cured at a temperature of 150 °C for 5 minutes. After curing the primer coat, the topcoat varnish coating composition was applied to the panel using a doctor blade to achieve an average film thickness between 4 and 5 microns. The topcoat coating composition was then cured in a Nordson Minicure UV Conveyor Curing Oven according to the manufacturer's instructions.

[0566] MEK double rub: The number of reciprocating rubs required to remove the coating was measured using a degreased cotton ball soaked in methyl ethyl ketone (MEK).

[0567] Flexibility: Cut a 15 cm x 15 cm coated panel and place it in a die cutter to produce a club box shape with 4 different curved corners. Visually evaluate the degree of damage and record it using the following alphanumeric scale, where the higher the number and the "further back" the letter in the alphabet, the better the result. For example, the best result would be 5E, and the worst result would be 1A:

[0568] Damage Description Rating E No damage detected 5 D Very fine cracks 4 C Fine cracks 3 B Delamination points 2 A Delamination 1

[0569] The results are shown in Table 5.

[0570] Table 5 - Results

[0571]

[0572] The results show that the UV - curable topcoat coating composition of the present invention, i.e., the UV - curable topcoat coating composition according to the present disclosure, performs as well as or better than the compositions of the comparative examples. This means that the topcoat composition of the present invention is suitable for use as a clear topcoat in the multi - layer coating system of the present disclosure.

[0573] Attention is directed to all papers and documents that are filed simultaneously with or prior to this application and with this specification and are publicly available for review with this specification, and the contents of all such papers and documents are hereby incorporated by reference.

[0574] All features disclosed in this specification (including any appended claims, abstract, and drawings) and / or all steps of any method or process so disclosed may be combined in any combination, except where at least some of such features and / or steps are mutually exclusive.

[0575] Each feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by an alternative feature for the same, equivalent, or similar purpose, unless otherwise expressly stated. Thus, unless otherwise expressly stated, each feature disclosed is only one example of a series of equivalent or similar features.

[0576] The present disclosure is not limited to the foregoing details. The present disclosure extends to any novel feature or any novel combination of the features disclosed in this specification (including any appended claims, abstract, and drawings) or to any novel step or any novel combination of the steps of any method or process so disclosed.

Claims

1. A multi-layer coating system, comprising: i) a primer coating derived from a UV-curable primer coating composition, the UV-curable primer coating composition comprising: a1) an epoxy material; b1) a polyol material and / or a diketone-functional material having a hydroxyl value (OHV) of at least 35 mg KOH / g; and c1) a photoinitiator; ii) an ink layer directly disposed on the primer coating, the ink layer derived from an ink composition, optionally wherein the ink composition is digitally printed; and iii) optionally, a topcoat coating directly disposed on the ink layer, the topcoat coating derived from a topcoat coating composition.

2. The multi-layer coating system according to claim 1, wherein the UV-curable primer coating composition has a solids content of at least 95% by weight based on the total weight of the composition.

3. The multi-layer coating system according to any one of claims 1 or 2, wherein the UV-curable primer coating composition comprises a polyol material in an amount of at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight, based on the total solids weight of the composition; and / or wherein the UV-curable primer coating composition comprises a diketone-functional material, such as an acetoacetate-functional material, in an amount of at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight, based on the total solids weight of the composition.

4. The multi-layer coating system according to any one of claims 1 to 3, wherein the epoxy material comprises an alicyclic epoxy resin.

5. The multi-layer coating system according to any one of claims 1 to 4, wherein the UV-curable primer coating composition comprises 55 to 85% by weight of an epoxy material based on the total solids weight of the composition.

6. The multi-layer coating system according to any one of claims 1 to 5, wherein the photoinitiator comprises a cationic photoinitiator.

7. The multi-layer coating system according to any one of claims 1 to 6, wherein the UV-curable primer coating composition is substantially free of polytetrafluoroethylene (PTFE).

8. The multi-layer coating system according to any one of claims 1 to 7, wherein the polyol material, when present, has a hydroxyl value (OHV) of at least 50 mg KOH / g, such as at least 100 mg KOH / g; and / or wherein the polyol material, when present, has an acid value (AV) of up to 10 mg KOH / g; and / or wherein the polyol material, when present, has a number average molecular weight (Mn) of up to 5,000 Da.

9. The multi-layer coating system according to any one of claims 1 to 8, wherein the UV-curable primer coating composition further comprises a polyester material, such as a polyester material having an OHV of less than 35 mg KOH / g, such as up to 30 mg KOH / g.

10. The multi-layer coating system according to claim 9, wherein the polyester material is present in an amount of 6 to 20% by weight based on the total solids weight of the composition.

11. The multi-layer coating system according to any one of claims 1 to 10, wherein the UV-curable primer coating composition comprises 1 to 5% by weight of a photoinitiator based on the total solid weight of the composition.

12. A plastic packaging, on at least a part of which is coated with the multi-layer coating system according to any one of claims 1 to 11.

13. A method for producing a plastic packaging, the method comprising the following steps: I) Applying the UV-curable primer coating composition according to any one of claims 1 to 11 to at least a part of the plastic packaging; II) Curing the UV-curable primer coating composition to form a cured primer coating; III) Applying an ink composition, such as by digital printing, on at least a part of the primer coating; IV) Curing the ink composition to form an ink layer; V) Optionally applying a topcoat coating composition on at least a part of the ink layer; and VI) Curing the topcoat coating composition, if present, to form a cured topcoat coating.

14. The packaging according to claim 12 or the method according to claim 13, wherein the plastic packaging comprises polyethylene and / or polypropylene; and / or wherein the plastic packaging comprises an extruded and / or injection-molded plastic tube.

15. A multi-layer coating system for aluminum packaging such as an aluminum one-piece spray can and / or tube, the multi-layer coating system comprising: i) Optionally a primer coating, which is derived from a primer coating composition; ii) An ink layer, which is directly disposed on the aluminum packaging and / or the primer coating if present, the ink layer being derived from an ink composition, optionally wherein the ink composition is digitally printed; and iii) An outer coating layer, which is directly disposed on the ink layer, the outer coating layer being derived from a UV-curable outer coating composition, the UV-curable outer coating composition comprising: a2) An epoxy material; b2) A polyol material and / or a diketone functional material; and c2) A photoinitiator.

16. The multi-layer coating system according to claim 15, wherein the UV-curable outer coating composition has a solids content of at least 95% by weight based on the total weight of the composition.

17. The multi-layer coating system according to any one of claims 15 or 16, wherein the UV-curable outer coating composition comprises at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight of a polyol material based on the total solid weight of the composition; and / or wherein the UV-curable outer coating composition comprises at least 2% by weight, such as at least 5% by weight, such as 5 to 30% by weight of a diketone functional material, such as an acetoacetate functional material, based on the total solid weight of the composition.

18. The multi-layer coating system according to any one of claims 15 to 17, wherein the epoxy material comprises an alicyclic epoxy resin.

19. The multi-layer coating system according to any one of claims 15 to 18, wherein the UV-curable topcoat paint composition comprises 55 to 85% by weight of an epoxy material based on the total solids weight of the composition.

20. The multi-layer coating system according to any one of claims 15 to 19, wherein the photoinitiator comprises a cationic photoinitiator.

21. The multi-layer coating system according to any one of claims 15 to 20, wherein the UV-curable topcoat paint composition is substantially free of polytetrafluoroethylene (PTFE).

22. The multi-layer coating system according to any one of claims 15 to 21, wherein the UV-curable primer coat paint composition comprises a polyol material having a hydroxyl value (OHV) of at least 25 mg KOH / g.

23. The multi-layer coating system according to any one of claims 15 to 21, wherein the UV-curable topcoat paint composition comprises 1 to 10% by weight of a photoinitiator based on the total solids weight of the composition.

24. The multi-layer coating system according to any one of claims 15 to 23, wherein the UV-curable topcoat paint composition further comprises wax, such as wax comprising micronized wax and / or micronized polysaccharide; and / or wherein the UV-curable topcoat paint composition further comprises a reactive diluent, such as a reactive diluent comprising an oxetane group.

25. The multi-layer coating system according to any one of claims 15 to 23, wherein the UV-curable topcoat paint composition further comprises a (meth)acrylate functional material and optionally a free radical initiator, such as a (meth)acrylate functional material and a free radical initiator.

26. An aluminum package, such as an aluminum one-piece spray can and / or tube, having a multi-layer coating system applied to at least a portion of the aluminum package, the multi-layer coating system comprising: i) an optional primer coat, the primer coat being derived from a primer paint composition; ii) an ink layer, the ink layer being disposed directly on the aluminum package and / or the primer coat if present, the ink layer being derived from an ink composition, optionally wherein the ink composition is digitally printed; and iii) a topcoat layer, the topcoat layer being disposed directly on the ink layer, the topcoat layer being derived from a UV-curable topcoat paint composition, the UV-curable topcoat paint composition comprising: a2) an epoxy material; b2) a polyol material and / or a diketone functional material; and c2) a photoinitiator.

27. A method of producing an aluminum package such as an aluminum one-piece spray can and / or tube, the method comprising the steps of: I) optionally applying a primer paint composition to at least a portion of the aluminum package; II) curing the primer coat paint composition if present to form a cured primer coat layer; III) applying an ink composition, such as by digital printing, to at least a portion of the aluminum package or the primer coat if present; IV) curing the ink composition to form an ink layer; V) Applying a UV-curable topcoat coating composition, the UV-curable topcoat coating composition comprising: a2) an epoxy material; b2) a polyol material and / or a diketone functional material; and c2) a photoinitiator; and VI) Curing the UV-curable topcoat coating composition to form a cured topcoat coating.

28. The package according to claim 26 or the method according to claim 27, wherein the aluminum package is for packaging cosmetic, food product, beverage, and / or pharmaceutical products.

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