Adhesives for hard to bond surfaces in multi-layer constructions

Abstract

Adhesive compositions for bonding to surfaces such as polyolefin or poly(ethylene vinyl alcohol) include a) a chlorinated thermoplastic resin, b) a halogen-free modified polyolefin-based resin, c) an acrylic resin with a Tg less than or equal to -30°C, and d) at least one isocyanate-functional crosslinker. The adhesive composition is a heat activated adhesive such that when formed into an adhesive layer, the adhesive layer adheres to polyolefin and polyethylene vinyl alcohol) substrates and has impact resistance at -30°C. Adhesive layers are formed by disposing an adhesive solution with the adhesive composition and a solvent and drying.

Description

[0001] ADHESIVES FOR HARD TO BOND SURFACES IN MULTI-LAYER CONSTRUCTIONS

[0002] Summary

[0003] Disclosed herein are adhesive compositions for forming heat activated adhesive layers, Transfer Gravure Printing) sheets prepared with the heat activated adhesive compositions, and multi-layer articles that contain the heat activated adhesive layers.

[0004] In some embodiments, the adhesive composition comprises a) a chlorinated thermoplastic resin, b) a halogen-free modified polyolefin-based resin, c) an acrylic resin with a Tg less than or equal to -30°C, and d) at least one crosslinker comprising an isocyanate-functional crosslinker. The adhesive composition is a heat activated adhesive such that when formed into an adhesive layer, the adhesive layer adheres to polyolefin and polyethylene vinyl alcohol) substrates and has impact resistance at -30°C. Typically, the adhesive layer is formed by disposing an adhesive solution on a substrate and drying the solution to form the adhesive layer, where the adhesive solution comprises the adhesive composition and at least one solvent.

[0005] Also disclosed are TGP (Transfer Gravure Printing) sheets comprising a carrier film; a thermally adherable thermoplastic resin layer disposed on the carrier film, a color layer disposed on the thermally adherable thermoplastic resin layer wherein the color layer comprises a pigment dispersed in a binder, and a heat activated adhesive layer disposed on the color layer. The heat activated adhesive layer has been described above.

[0006] Also disclosed are methods of making multi-layer film articles. In some embodiments, the method comprises preparing a TGP (Transfer Gravure Printing) sheet. The TGP sheet is prepared by providing a carrier film, depositing a thermally adherable thermoplastic resin composition on the carrier film and drying the thermally adherable thermoplastic resin composition to form a thermally adherable thermoplastic resin layer, depositing a color solution comprising a pigment in a binder on the thermally adherable thermoplastic resin layer to form a color layer, and forming a heat activated adhesive composition on the color layer, where forming the heat activated adhesive layer comprises depositing an adhesive solution on the color layer, and drying the adhesive solution to form the heat activated adhesive layer. The adhesive solution comprises the adhesive composition described above and at least one solvent.

[0007] The method further comprises preparing a top layer article, where the top layer article comprises a multi-layer film with at least 2 layers comprising a polyolefin-based film and a support film, heat laminating the top layer to the TGP sheet by contacting the support layer of the top layer to the heat activated adhesive layer of the TGP sheet and applying heat and pressure to form an intermediate article, removing the carrier film from the intermediate article to expose the thermally adherable thermoplastic resin layer, providing an adhesive article with a second adhesive layer disposed on a release liner, heat laminating the second adhesive layer to the intermediate article such that the phenoxy adhesive layer contacts the second adhesive layer and applying heat and pressure to form a secondary article, and heating and contacting the polyolefin-based film surface of the top layer of the secondary article to an embossing tool to impart a structured surface to the top layer.

[0008] Brief Description of the Drawings

[0009] The present application may be more completely understood in consideration of the following detailed description of various embodiments of the disclosure in connection with the accompanying drawings.

[0010] Figure 1 is a cross sectional view of a Transfer Gravure Printing Sheet article of this disclosure.

[0011] Figure 2 is a cross sectional view of a decorative article of this disclosure.

[0012] Figure3 is a cross sectional view of another decorative article of this disclosure.

[0013] The figures are not necessarily to scale. Like numbers used in the figures refer to like components.

[0014] Detailed Description

[0015] Decorative films such as those for interior decorative articles are used to decorate the interior parts of automobiles. The use of these materials is effective in improving the work environment because installing decorative panels requires no volatile organic compounds (VOC) or any spray mist. The decorative films generally have an outermost layer which protects the decorative article. Generally, the decorative article has an adhesive layer to mount the decorative article in a vehicle. Between the outermost layer and an adhesive layer, the article includes a variety of layers. Among these layers are aesthetic layers such as one or more color layers and / or one or more metal layers. The layers may also include adhesive layers to bond together these layers.

[0016] The outermost layer has a number of requirements. These requirements include chemical resistance, thermal resistance, desirable hardness, stain resistance, and the like. In some articles, the outermost layer of the interior trim articles is a fluorocarbon-based film layer, as fluorocarbon films fulfill these requirements. However, these films also have undesirable features such as high cost. Additionally, as the forward trend is to eliminate the use of fluorocarbon-based films, it is desirable to develop interior trim articles with outermost layers that do not have fluorocarbon films.

[0017] Replacement of outermost layer fluorocarbon films is difficult, since, as described above, the outermost layers have a variety of needed properties including hardness. Polyolefin-based films are potential candidates as replacement films since polyolefin-based films have desirable thermal resistance and stain resistance properties and are relatively inexpensive. However, it was discovered that polyolefin-based films did not have the required hardness. Therefore, multi-layer films with an exterior polyolefin-based film that could meet the hardness requirements were developed. These multi-layer films comprise either 2-layer films comprising polyolefin film / support film or 3 -layer films comprising polyolefin film / support film / polyolefin film. In many embodiments, the support film is a poly(ethylene vinyl alcohol) film. Poly(ethylene vinyl alcohol) is often abbreviated as poly-EVOH, and this abbreviation is used throughout this disclosure.

[0018] These multi-layer films are not without complications, however. The multilayer films are either 2-layer films comprising polyolefin film / support film or 3- layer films comprising polyolefin film / support film / polyolefin film. The polyolefin films and support films are difficult for adhesives to bond, and this adhesive weakness compromises the integrity of the overall article. Therefore, adhesives that bond strongly to the polyolefin or support films of the newly developed exterior layers of the multi-layer trim film articles are needed.

[0019] Disclosed herein are adhesives that adhere strongly to the polyolefin or support films of the newly developed exterior layers of the multi-layer trim film articles. These adhesives are heat activated adhesives that are formed from adhesive solutions that are deposited on a substrate and dried. The heat activated adhesives can be heat laminated to polyolefin or support films to give strong adhesion. Also disclosed are decorative film articles that include the adhesives and methods of preparing the decorative film articles, such as interior trim film articles.

[0020] The term “adhesive” as used herein refers to polymeric compositions useful to adhere together two adherends. Examples of adhesives are heat activated adhesives.

[0021] Heat activated adhesives are non-tacky at room temperature but become tacky and capable of bonding to a substrate at elevated temperatures. These adhesives usually have a Tg(glass transition temperature) or melting point (Tm) above room temperature. When the temperature is elevated above the Tgor Tm, the storage modulus usually decreases and the adhesive becomes tacky.

[0022] The term “(meth)acrylate” refers to monomeric acrylic or methacrylic esters of alcohols. Acrylate and methacrylate monomers or oligomers are referred to collectively herein as "(meth)acrylates”. Materials referred to as “(meth)acrylate functional” are materials that contain one or more (meth)acrylate groups. The term “(meth)acrylic” as used herein refers to both acrylic and methacrylic compounds, where acrylic and methacrylic compounds are of the general structure: CH2=CR1-(C0)-, where R1is an H or a methyl group. When this group is linked to an -OR group where R is an alkyl or other substituted alkyl group, the compound is a (meth)acrylate as described above, when it is linked to an amino group -NR2 where each R group is independently an H or an alkyl group, the compound is a (meth)acrylamide.

[0023] The terms "room temperature" and "ambient temperature" are used interchangeably to mean temperatures in the range of 20°C to 25°C.

[0024] The terms “Tg” and “glass transition temperature” are used interchangeably. If measured, Tg values are determined by Differential Scanning Calorimetry (DSC) at a scan rate of 10°C / minute, unless otherwise indicated. Typically, Tg values for copolymers are not measured but are calculated using the well-known Fox Equation, using the homopolymer Tg values provided by the monomer supplier, as is understood by one of skill in the art.

[0025] The term “adjacent” as used herein when referring to two layers means that the two layers are in proximity with one another with no intervening open space between them. They may be in direct contact with one another (e.g. laminated together) or there may be intervening layers.

[0026] The terms “polymer” and “macromolecule” are used herein consistent with their common usage in chemistry. Polymers and macromolecules are composed of many repeated subunits. As used herein, the term “macromolecule” is used to describe a group attached to a monomer that has multiple repeating units. The term “polymer” is used to describe the resultant material formed from a polymerization reaction.

[0027] Unless otherwise indicated, the terms “transparent”, and “visible light transmissive” are used interchangeably, and refer to an article, fdm or adhesive that has a high light transmittance over at least a portion of the visible light spectrum (about 400 to about 700 nm). Typically, transparent articles have a visible light transmittance of at least 50%. The term “transparent fdm" refers to a fdm having a thickness and when the fdm is disposed on a substrate, an image (disposed on or adjacent to the substrate) is visible through the thickness of the transparent fdm. In many embodiments, a transparent fdm allows the image to be seen through the thickness of the fdm without substantial loss of image clarity. In some embodiments, the transparent fdm has a matte or glossy finish.

[0028] The terms “EVOH” and “poly-EVOH” are used interchangeably and refer to poly(ethylene-vinyl alcohol).

[0029] Disclosed herein are adhesive compositions suitable for preparing multi-layer interior trim fdm articles. The adhesives are capable of bonding to surfaces that are difficult for traditional adhesives to form strong bonds. Also disclosed are multi-layer fdm articles and methods for making multi-layer fdm articles.

[0030] Disclosed herein are adhesive compositions. In some embodiments, the adhesive compositions comprise: a) a chlorinated thermoplastic resin; b) a halogen-free modified polyolefin-based resin; c) an acrylic resin with a Tg less than or equal to -30°C; and d) at least one crosslinker comprising an isocyanate-functional crosslinker. The adhesive compositions are typically used in the form of adhesive solutions, where the adhesive solutions comprise the adhesive compositions and at least one solvent. The adhesive solution upon coating and drying forms a heat activated adhesive layer comprising the adhesive composition. The heat activated adhesive layer is capable of bonding to polypropylene-based substrates and poly-EVOH (poly (ethylene vinyl alcohol)) substrates, and has impact resistance at -30°C.

[0031] The adhesive composition includes a chlorinated thermoplastic resin. A wide range of chlorinated thermoplastic resins are suitable. In some embodiments, the chlorinated thermoplastic resin comprises a chlorinated olefinic polymer. Particularly suitable are chlorinated polypropylene polymers. Examples of suitable chlorinated thermoplastic resins include SUPERCHLON 822S and SUPERCHLON 836S from Nippon Paper Industries, Co. Particularly suitable is SUPERCHLON 822S from Nippon Paper Industries, Co.

[0032] The adhesive composition also includes a halogen-free modified polyolefin-based resin. In some embodiments, the halogen-free modified polyolefin-based resin comprises a special modified polyolefin resin, as described in the literature for compounds available from Nippon Paper Industries. Co. Examples of suitable halogen-free modified polyolefin-based resins are AUROREN 150S, AUROREN 200S, AUROREN 353S, and AUROREN 35 OS from Nippon Paper Industries, Co. Particularly suitable is AUROREN 350S from Nippon Paper Industries, Co.

[0033] The adhesive composition also includes an acrylic resin with a Tg less than or equal to -30°C. A wide range of acrylic resins are suitable. In some embodiments, the acrylic resin is a liquid acrylic resin that is hydroxyl -functional. An example of an acrylic resin with a Tg less than or equal to -30°C is ALFON UH-2000 from Toagosei Co.

[0034] The adhesive composition also includes at least one crosslinker comprising an isocyanate-functional crosslinker. Typically, the isocyanate-functional crosslinker is a polyisocyanate. Examples of polyisocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, aromatic aliphatic polyisocyanates and the like, and multimers (dimers, trimers and the like), biuret-modified products, allophanate- modified products, oxadiazine trione-modified products and carbodiimide-modified products of these polyisocyanates. Polyisocyanates may be used as one type alone or in a combination of two or more types. In some embodiments, a particularly suitable crosslinker is an isocyanurate crosslinker such as DURANATE TPA-100 from Asahi Kasei Corporation.

[0035] In some embodiments, it may be desirable to include a second optional crosslinker. Typically, the second optional crosslinker is an epoxy-functional crosslinker.

[0036] A wide range of composition ranges are suitable for the adhesive compositions of this disclosure. In some embodiments, the adhesive composition comprises: a) 49 - 99.5 parts by weight of chlorinated thermoplastic resin; b) 0 - 50 parts by weight of a halogen-free modified polyolefin-based resin; c) 2.5 - 12.5 parts by weight of an acrylic resin with a Tg less than or equal to -30°C; and d) 3.7 - 10 parts by weight of at least one isocyanate -functional crosslinker.

[0037] In some embodiments, the adhesive composition further comprises up to 1.0 part by weight of at least one epoxy-functional crosslinker. As with the isocyanate-functional crosslinker, the epoxy-functional crosslinker is typically at least difunctional. A suitable epoxy-functional crosslinker is the tetrafunctional E-5XM from Soken Chemical and Engineering Co., Ltd.

[0038] The adhesive layer can also comprise a variety of optional additives. Among the suitable additives are UV stabilizers and anti-oxidants. Suitable UV stabilizers include HALS (Hindered Amine Light Stabilizers) such as ADK stab LA 63P from Adeka Corporation. Suitable anti-oxidants include IRGANOX 1098 from BASE and ADK stab 2112 from Adeka Corporation, as well as combinations of these materials. Combinations of additives can also be used. Additionally, while not required, an ultraviolet absorbing agent can be used if desired.

[0039] As mentioned above, typically the adhesive composition is disposed on a substrate as a solution comprising the adhesive composition and at least one solvent. Suitable solvents include: aliphatic solvents such as hexane, heptane, cyclohexane, methylcyclohexane, and the like; aromatic solvents such as toluene and xylene; ketones such as acetone and MEK (methyl ethyl ketone); and esters such as ethyl acetate.

[0040] The adhesive composition is used to form adhesive layers. The adhesive solution, comprising the adhesive composition and at least one solvent, is disposed upon a surface and is dried to form the adhesive layer. The adhesive solution can be disposed using a variety of techniques including coating and printing techniques. In some embodiments, gravure printing is particularly suitable. Often drying involves the use of elevated temperature, for example by placing the coating in an oven. The adhesive layer is a heat activated adhesive, being non-tacky at room temperature and becoming tacky upon heating. The adhesive layer is able to be heat laminated at a temperature of 120°C to form an adhesive bond. The adhesive layer has desirable features such as the ability to adhere to a wide range of substrates, including polyolefin-based substrates and poly-EVOH (poly (ethylene vinyl alcohol)) substrates. As will be described below, this feature is particularly suitable for formation of multi-layer articles such as multi-layer interior trim film articles. The adhesion required to form multi-layer interior trim film articles is described in greater detail below.

[0041] Additionally, the adhesives have a wide range of desirable properties including thermal stability, permitting not only use over a wide range of temperatures, but also elevated temperature processing. Additionally, the adhesive layers have desirable low temperature impact resistance down to a temperature of -30°C. The method of measuring low temperature impact resistance is described in the Examples section.

[0042] The adhesive compositions can be used to prepare TGP (Transfer Gravure Printing) sheets. TGP sheets are multi-layer articles that have an adhesive layer on each interface and at least one layer between, wherein the at least one layer is gravure printed. Typically, the TGP sheets have more than one layer between the external adhesive layers.

[0043] In some embodiments, the TGP sheet comprises a heat activated adhesive layer, a color layer disposed on the heat activated adhesive layer, a thermally adherable thermoplastic resin layer disposed on the color layer, and a carrier film disposed on the thermally adherable thermoplastic resin layer. The TGP sheet may contain additional layers as will be discussed below. The heat activated adhesive layer is a layer prepared from the adhesive compositions described above. The adhesive composition that forms the heat activated adhesive layer comprises: a) a chlorinated thermoplastic resin; b) a halogen-free modified polyolefin-based resin; c) an acrylic resin with a Tg less than or equal to -30°C; and d) at least one crosslinker comprising an isocyanate-functional crosslinker.

[0044] As mentioned above, the heat activated adhesive layer can be heat laminated to a layer of polyolefin such as polypropylene or a layer of poly-EVOH of atop layer article to form a laminated article. Among the features of these articles is that the adhesion between the heat activated adhesive and the top layer article is sufficiently strong that the carrier film of the TGP sheet can be removed from the laminated article without delamination of the bond between the heat activated adhesive and the layer of polypropylene or poly- EVOH.

[0045] The heat activated adhesive layer can have a range of thicknesses. Typically, the heat activated adhesive layer is relatively thin, having a thickness of at least 0.01 micrometers. In some embodiments, the heat activated adhesive layer has a thickness of from 0.1 - 5 micrometers.

[0046] The TGP sheets also comprise a color layer in contact with the first adhesive layer. Examples of suitable color layers include a color layer that exhibits a paint color, metallic color or the like, a pattern layer that imparts a logo, an image, or a pattern such as a wood grain pattern, stone grain pattern, geometric pattern or leather pattern to the structure, a relief (embossed pattern) layer in which recesses and protrusions are provided on the surface, and combinations thereof.

[0047] Pigments that may be used for the color layer by dispersion in a binder resin such as acrylic resin, polyurethane resin or the like are exemplified by inorganic pigments such as titanium oxide, carbon black, chrome yellow, yellow iron oxide, colcothar, red iron oxide, or the like; organic pigments such as phthalocyanine pigments (phthalocyanine blue, phthalocyanine green, or the like), azo lake pigments, indigo pigments, perinone pigments, perylene pigments, quinophthalone pigments, dioxazine pigments, quinacridone pigments (quinacridone red, or the like), or the like; aluminum brightening agents such as aluminum flake, vapor-deposited aluminum flake, metal oxide-coated aluminum flake, colored aluminum flake, or the like; and pearlescent brightening materials such as flakelike mica and synthetic mica coated with a metal oxide such as titanium oxide or iron oxide, or the like. The color layer can be formed by printing such as gravure direct printing, gravure offset printing, inkjet printing, laser printing, or screen printing, coating such as gravure coating, roll coating, die coating, bar coating, or knife coating. Examples of suitable color layers are described in US Patent No. 10,774,242 (Y asuda et al.).

[0048] The color layer may be a single layer or a multi-layer construction comprising multiple color layers. If the color layer is a multi-layer construction, the multiple layers generally contain different pigments. In embodiments in which the color layer is a multi - layer construction, one or more of the layers may be a patterned layer. The multi-layer color layer may contain different colors, different patterns, or both.

[0049] The color layer may have a variety of thicknesses, and it is generally not less than approximately 0.01 micrometers, not less than approximately 0.1 micrometers, or not less than approximately 0.8 micrometers, and not more than approximately 100 micrometers, not more than approximately 50 micrometers, or not more than approximately 10 micrometers.

[0050] The TGP sheets also comprise a thermally adherable thermoplastic resin layer in contact with the color layer. A number of suitable thermally adherable thermoplastic resin layer materials are suitable. Particularly suitable are phenoxy resins, or combinations of phenoxy resins and polyurethanes. In the present disclosure, “phenoxy resin” means a thermoplastic polyhydroxy polyether synthesized using a bisphenol and epichlorohydrin and encompasses those having an epoxy group derived from a tiny amount of epichlorohydrin in the molecule (for example, at the terminal). For example, the epoxy equivalent amount of phenoxy resin is higher than that of epoxy resin, for example, not less than 5,000, not less than 7,000 or not less than 10,000. Particularly suitable thermally adherable thermoplastic resin layer materials are phenoxy resin and polyurethane. Examples of suitable phenoxy resin and polyurethanes are described in US Patent No. 10,774,242 (Yasuda et al.).

[0051] In some embodiments, instead of the thermally adherable thermoplastic resin layer, a layer of heat activated adhesive can be used, either the heat activated adhesive described above or a different heat activated adhesive.

[0052] A variety of fdms are suitable for the carrier fdm. Particularly suitable fdms include polyester fdms such as PET (polyethylene terephthalate) fdms. In some embodiments, the carrier fdm may be a release liner. Release liners are well known in the adhesive arts. Exemplary release liners include those prepared from paper (e.g., Kraft paper) or polymeric material (e.g., polyolefins such as polyethylene or polypropylene, ethylene vinyl acetate, polyurethanes, polyesters such as polyethylene terephthalate, and the like, and combinations thereof). At least some release liners are coated with a layer of a release agent such as a silicone, a fluorosilicone-containing material or a fluorocarbon- containing material. The articles may also include additional layers. In some embodiments, the carrier film of the above-described articles are replaced with a multi-layer construction. These multi-layer constructions comprise a second adhesive layer disposed on a release liner and optionally may comprise a vapor-deposited metal layer on the second adhesive layer.

[0053] The articles also comprise a second adhesive layer in contact with the thermally adherable thermoplastic resin layer. The second adhesive layer may be a heat activated adhesive, wither the same as described above or a different heat activated adhesive. In some embodiments, the second adhesive layer comprises a (meth)acry late -based adhesive layer comprising a cured layer prepared from a reaction mixture comprising: at least one alkyl (meth)acrylate; at least one (meth)acrylic monomer with a basic-functional group; at least one (meth)acrylate copolymer with a Tg of at least 55°C; at least one crosslinking monomer; and at least one initiator.

[0054] Examples of suitable second adhesives are described in the co-pending application Attorney Docket Number PA102510US01 fded on the same day as the current application.

[0055] The articles also comprise a release liner in contact with the second adhesive layer. Release liners are well known in the adhesive arts. Exemplary release liners include those prepared from paper (e.g., Kraft paper) or polymeric material (e.g., polyolefins such as polyethylene or polypropylene, ethylene vinyl acetate, polyurethanes, polyesters such as polyethylene terephthalate, and the like, and combinations thereof). At least some release liners are coated with a layer of a release agent such as a silicone, a fluorosilicone- containing material or a fluorocarbon-containing material.

[0056] The multi-layer constructions may also include additional layers. One particularly suitable additional layer is a vapor-deposited metal layer between the second adhesive layer and the thermally adherable thermoplastic resin layer. This vapor-deposited metal layer can aid in enhancing the visual appearance of the trim article. Light contacting the metal layer is reflected back through the color layer giving the trim article a metallic-like appearance. A variety of metals can be used, especially suitable metals are aluminum, tin, and indium or their oxidation products. A method for vapor-depositing metal onto the second adhesive layer is described in the co-pending application Attorney Docket Number PA102510US01 filed on the same day as the current application. The TGP sheets are designed to be adhered to top layer articles to form an interior trim fdm article. As mentioned above, one desirable feature of the interior trim articles of this disclosure is that they do not contain fluorocarbon fdm layers. The top layer articles of this disclosure do not contain fluorocarbon fdm layers but have many of the desirable properties of top layer articles that contain fluorocarbon fdm layers. The top layer articles are adhered to TGP sheets by disposing the top layer articles on the heat activated adhesive layer of the TGP sheets. As mentioned above, the adhesive compositions of this disclosure are designed to adhere to the top layer articles.

[0057] The top layer articles have a first major surface and a second major surface and comprise a transparent multi-layer fdm with at least 2 layers. The 2 layers are an outermost layer and a bottom layer. The outermost layer comprises a first polyolefin- based layer and the bottom layer is a support fdm that is a transparent fdm layer with a pencil hardness of at least B. The first major surface of the top layer article is a structured surface comprising a plurality of protrusions arising from a base surface where the protrusions have a height of at least 5 micrometers, and the top layer article has a pencil hardness of at least 2B. In some embodiments, the top layer article further comprises a second polyolefin-based layer disposed on the support fdm, where the second polyolefin- based layer is the bottom layer and the support fdm is disposed between the two polyolefin-based layers. Typically, the polyolefin-based layer and the support layer comprise crystalline materials, and the thermoforming operations described below tend to increase the pencil hardness of these layers. However, even after thermoforming, the polyolefin-based layer, without the support layer, did not have sufficient pencil hardness.

[0058] A variety of materials are suitable for use as the first polyolefin-based layer of the top layer article. In many embodiments, the first polyolefin-based layer comprises a polypropylene-based layer. A particularly suitable polypropylene material is MODIC P555 from Mitsubishi Chemical Corporation.

[0059] Besides the polypropylene material, the first polyolefin-based layer can also comprise a variety of optional additives. Among the suitable additives are UV stabilizers and anti-oxidants. Suitable UV stabilizers include HALS (Hindered Amine Light Stabilizers) such as ADK stab LA 63P from Adeka Corporation. Suitable anti-oxidants include IRGANOX 1098 from BASF Japan Co., Ltd. and ADK stab 2112 from Adeka Corporation, as well as combinations of these materials. Combinations of additives can also be used. Also, while not required, an ultraviolet absorbing agent can be used if desired.

[0060] As mentioned above, some embodiments comprise top layer articles with 3 layers: a first polyolefin-based layer / a support film / a second polyolefin-based layer. In many of these embodiments, the polyolefin-based layers comprise a polypropylene-based layer as described above. In some embodiments, the two polyolefin-based layers comprise the same materials.

[0061] A variety of materials are suitable for use in the support film of the top layer articles. The support film comprises a transparent film layer with a pencil hardness of at least B. Suitable materials include poly(ethylene-vinyl alcohol) often abbreviated as EVOH, and a cured poly(meth)acrylate layer. Examples of suitable materials include EVOH AT4403B from Mitsubishi Chemical Corporation and EVOH E105B from Kuraray Co., Ltd.. Particularly suitable materials are EVOH AT4403B from Mitsubishi Chemical Corporation.

[0062] The top layer articles can have a range of thicknesses. In some embodiments, the top layer article has a thickness of at least 30 micrometers. Each of the layers can also have a variety of thicknesses. In some embodiments, the first polyolefin-based layer has a thickness of from 1-30 micrometers and the support layer has a thickness of at least 1 times the thickness of the first polyolefin-based layer. In embodiments where the top layer article comprises 3 layers, the first polyolefin-based layer has a thickness of from 1-30 micrometers, the support layer has a thickness of at least 1 times the thickness of the first polyolefin-based layer, and the second polyolefin -based layer has a thickness of from 1-30 micrometers. In some embodiments, the support layer is at least 3 times the thickness of the first polyolefin-based layer.

[0063] The top layer article may further comprise optional layers. One particularly suitable layer is a bonding layer to facilitate the bonding of the polyolefin-based layer or layers to EVOH, when EVOH is used as the support film. Therefore, in some embodiments, the top layer article further comprises a bonding layer between the first polyolefin-based layer and the support film, between the support film and the second polyolefin-based layer, or both, where the bonding layer comprises a thermoplastic modified polyolefin. A particularly suitable material for use in the bonding layer is ADMER ADHESIVE RESIN from Mitsui Chemicals Inc. Also disclosed herein are methods for preparing multi-layer fdm articles. In some embodiments, the method comprises preparing a TGP (Transfer Gravure Printing) sheet. The method comprises providing a carrier fdm, and depositing a thermally adherable thermoplastic resin composition on the carrier fdm, drying the thermally adherable thermoplastic resin composition to form a thermally adherable thermoplastic resin layer, depositing a color solution comprising a pigment in a binder on the thermally adherable thermoplastic resin layer to form a color layer, and depositing a heat activated adhesive composition on the color layer to form a heat activated adhesive layer. Each of these layers have been described in detail above.

[0064] The heat activated adhesive layer comprises an adhesive composition that has been deposited on the color layer and dried. The adhesive composition comprises: a) a chlorinated thermoplastic resin; b) a halogen-free modified polyolefin-based resin; c) an acrylic resin with a Tg less than or equal to -30°C; and d) at least one crosslinker comprising an isocyanate-functional crosslinker. Typically, the adhesive composition is deposited as an adhesive solution comprising the adhesive composition and at least one solvent. After deposition, the adhesive solution is dried to form a layer of heat activated adhesive. The adhesive compositions are described in detail above.

[0065] The method further comprises preparing a top layer article, wherein the top layer article comprises a multi-layer film with at least 2 layers comprising a polyolefin-based film and a support film, heat laminating the top layer to the TGP sheet by contacting the support layer of the top layer to the heat activated adhesive layer of the TGP sheet and applying heat and pressure to form an intermediate article. Top layer articles have been described in detail above. In some embodiments, the top layer article comprises a 3-layer construction comprising a polyolefin-based film, a support film, and a second polyolefin- based film.

[0066] The method further comprises removing the carrier film from the intermediate article to expose the thermally adherable thermoplastic resin layer, providing an adhesive article with a second adhesive layer disposed on a release liner, heat laminating the second adhesive layer to the intermediate article such that the thermally adherable thermoplastic resin composition layer contacts the second adhesive layer and applying heat and pressure to form a secondary article. The adhesive article may further comprise a vapor-deposited metal layer on the second adhesive layer. Such layers and constructions are described in detail above.

[0067] The method further comprises heating and contacting the polyolefin-based film surface of the top layer article of the secondary article to an embossing tool to impart a structured surface to the top layer.

[0068] In some embodiments, heat laminating the top layer article to the TGP sheet by applying heat and pressure comprises passing the top layer article / TGP sheet laminate through a heated nip roller.

[0069] The articles of this disclosure may be more fully understood by reference to the figures. Figure 1 shows article 100. Article 100 is a TGP sheet and comprises carrier film 110, thermally adherable resin thermoplastic resin layer 120, color layer 130 with optional color sublayers 131, 132, 133, and heat activated adhesive layer 140.

[0070] Figure 2 shows article 200. Article 200 is a decorative sheet and comprises adhesive article 250 comprising release liner 251 and (meth)acrylate -based adhesive layer 252, and optional metal layer 253. Disposed on adhesive article 250 is thermally adherable resin thermoplastic resin layer 220, color layer 230 with optional color sublayers 231, 232, 233, and heat activated adhesive layer 240. Disposed on heat activated adhesive layer 240 is top layer 260 comprising polyolefin-based layer 261, support layer 262, and optional polyolefin-based layer 263.

[0071] Figure 3 shows article 300. Article 300 is a decorative sheet and is article 200 that has had a structured surface imparted into the top layer 260. Article 300 comprises adhesive article 350 comprising release liner 351 and (meth)acrylate -based adhesive layer 352, and optional metal layer 353. Disposed on adhesive article 350 is thermally adherable resin thermoplastic resin layer 220, color layer 330 with optional color sublayers 331, 332, 333, and heat activated adhesive layer 340. Disposed on heat activated adhesive layer 340 is top layer 360 comprising polyolefin-based layer 361, support layer 362, and optional polyolefin-based layer 363. While layer 363 is shown as flat, in some embodiments the layer may not be flat but may have a pattern that mimics the pattern of the layers above (361 and 362). Additionally, the layers below layer 363, namely 340, 330, 320, 352, and 353, are also shown as flat but likewise may have a pattern that mimics the pattern of the layers above. Examples

[0072] These examples are merely for illustrative purposes only and are not meant to be limiting on the scope of the appended claims. All parts, percentages, ratios, etc. in the examples and the rest of the specification are by weight, unless noted otherwise.

[0073] Table of Abbreviations

[0074] Test Methods

[0075] Impact Resistance

[0076] Impact resistance was tested on vacuum formed multi-layer samples using the methods of Test Method JIS K5600-5-3 and ISO6272. Testing was carried out using a Dupont impact tester that sandwiched the test samples between a punch with a spherical tip having a fixed radius and a cradle with a recess of the same size as the tip of the lead. The steel weight (1 kilogram) was dropped from a height of 30 cm. The test was carried out in a room with a temperature of -30°C, and the test sample was allowed to dwell for at least 4 hours at that temperature prior to testing. After dropping the weight, the test sample was evaluated for intactness of the adhesive bonding in the multi-layer articles. The results are presented in the Adhesive Evaluation Tables as Pass (bond remains intact) or Fail (bond does not remain intact).

[0077] Adhesive Evaluation

[0078] Coated adhesive layers were evaluated at various stages of the process of forming multi-layer articles. The tackiness and adhesive bonding of the adhesive layer was evaluated according to these criteria:

[0079] Examples E1-E9 and Comparative Examples CE1-CE24

[0080] Formation of Top Layer Articles

[0081] The Top layer Article of Example El was a three-layer construction with the layers PP / EVOH / PP, where the PP layers were 20 micrometers thick and comprised of the components of Table 3, and the EVOH layer was EVOH-3 and had a thickness of 60 micrometers.

[0082] The Top layer Articles of Comparative Examples CE1-CE24 and Examples E2- E12 were one- or two-layer constructions. The constructions are shown in Table 1, where the layers, composition, and thicknesses are shown. Table 1

[0083] Formation of TGP (Transfer Gravure Printing) Sheets

[0084] The TGP sheet was formed in sequence with a carrier film of PET on which was deposited by a gravure print roller a Phenoxy Adhesive layer (the components of the Phenoxy Adhesive are shown in Table 2) and the layer was dried in an 80°C oven to form a layer of 0.1 micrometer. A Color layer solution of a pigment in a binder was gravure printed with a gravure print roller on the Phenoxy Adhesive layer and dried in an 80°C oven to form a layer of 0. 1 micrometer. An Adhesive Solution was gravure printed with a gravure print roller on the Color layer and dried in an 80°C oven to form an Adhesive Layer of 0.1 micrometer. The components of the Adhesive Solutions (Solutions 1-32) are shown in Tables 3A-3E. All components are in parts by weight. The Adhesive Solution that was used to form each Example is shown in Table 4.

[0085] Table 2: Phenoxy Adhesive

[0086] Table 3 A: Adhesive Solutions 1-7

[0087] Table 3B: Adhesive Solutions 8-14

[0088] Table 3C: Adhesive Solutions 15-21

[0089] Table 3D: Adhesive Solutions 22-28

[0090] Table 3E: Adhesive Solutions 29-32 Table 4

[0091] Formation of ATT (Adhesive Transfer Tape) Articles To form the ATT, the adhesive mixture shown in Table 5 was disposed on the release surface of a Liner and cured with UV light to form an adhesive layer of 40 micrometer thickness. In Example El, this ATT had indium metal vapor deposited using a vapor coater to give a metal thickness of 30-60 nanometers.

[0092] Table 5

[0093] Lamination of Top Layer Article to TGP Sheet to Form Intermediate Article

[0094] The Top Layer Article was laminated to the TGP sheet by contacting the bottom most layer of the Top Layer Article to the Adhesive Layer of the TGP and passing the construction through 120°C nip rolls. The resultant article is an Intermediate Article.

[0095] Removal of PET Carrier Film (Initial Bonding) from Intermediate Article

[0096] The PET carrier film was removed from the laminated construction prepared above, and the construction was inspected for the intactness of the bonding as described in the Adhesive Evaluation Test Method above. The results are shown in Table 6.

[0097] Lamination of Intermediate Article to ATT Article to Form Secondary Article

[0098] The Intermediate Article with the PET carrier film removed was laminated to ATT sheet by contacting the Phenoxy Adhesive layer of the Intermediate Article to the Adhesive Layer or the metal layer of the ATT article and passing the construction through 120°C nip rolls. The resultant article is a Secondary Article.

[0099] Embossing of the Secondary Article (After Embossing Bonding) The secondary article was heated to 180°C and passed under an embossing roll (100-micrometer texture depth) to form an embossed pattern in the topmost polypropylene-based layer of the Secondary Article. The construction was inspected for the intactness of the bonding as described in the Adhesive Evaluation Test Method above. The results are shown in Table 6.

[0100] Vacuum Forming of the Embossed Article (After Forming Bonding)

[0101] The release liner was removed from the Embossed Article and the exposed adhesive layer was contacted to the surface of a PC / ABS panel and the resultant construction was vacuum formed by TOM (Three-dimensional Overlay Method) by passing through a thermoforming machine (from Fu-se Vacuum Forming, LTD., model number NGF-0709) at a temperature of 120°C and elongation of 100%. The results are shown in Table 6.

[0102] Adhesive Testing

[0103] Adhesive testing of selected samples was carried out as described in the test method above. The results are shown in Table 6.

[0104] Table 6

[0105]

[0106] NT = Not Tested

Claims

What is claimed is:

1. An adhesive composition comprising: a) a chlorinated thermoplastic resin; b) a halogen-free modified polyolefin-based resin; c) an acrylic resin with a Tg less than or equal to -30°C; and d) at least one crosslinker comprising an isocyanate-functional crosslinker, wherein the adhesive composition is a heat activated adhesive such that when formed into an adhesive layer, the adhesive layer adheres to polyolefin and polyethylene vinyl alcohol) substrates and has impact resistance at -30°C.

2. The adhesive composition of claim 1, wherein the adhesive layer is formed by disposing an adhesive solution on a substrate and drying the solution to form the adhesive layer, wherein the adhesive solution comprises the adhesive composition and at least one solvent.

3. The adhesive composition of claim 1, wherein the chlorinated thermoplastic resin comprises a chlorinated olefinic polymer.

4. The adhesive composition of claim 1, wherein the chlorinated thermoplastic resin comprises a chlorinated polypropylene.

5. The adhesive composition of claim 1, wherein the acrylic resin comprises a hydroxyl- functional acrylic liquid polymer.

6. The adhesive composition of claim 1, comprising a) 49 - 99.5 parts by weight of chlorinated thermoplastic resin; b) 0 - 50 parts by weight of a halogen-free modified polyolefin-based resin; c) 2.5 - 12.5 parts by weight of an acrylic resin with a Tg less than or equal to -30°C; and d) 3.7 - 10 parts by weight of at least one isocyanate -functional crosslinker.

7. The adhesive composition of claim 6, further comprising up to 1.0 part by weight of at least one epoxy-functional crosslinker.

8. The adhesive composition of claim 1, wherein the heat activated adhesive layer is heat bondable at a temperature of 120°C.

9. A TGP (Transfer Gravure Printing) sheet comprising: a carrier film; a thermally adherable thermoplastic resin layer disposed on the carrier film; a color layer disposed on the thermally adherable thermoplastic resin layer wherein the color layer comprises a pigment dispersed in a binder; and a heat activated adhesive layer disposed on the color layer, wherein the heat activated adhesive layer comprises: a) a chlorinated thermoplastic resin; b) a halogen-free modified polyolefin-based resin; c) an acrylic resin with a Tg less than or equal to -30°C; and d) at least one crosslinker comprising an isocyanate-functional crosslinker, wherein the heat activated adhesive layer is formed by disposing an adhesive solution on a substrate and drying the solution to form the adhesive layer, wherein the adhesive solution comprises the adhesive composition and at least one solvent, and has impact resistance at - 30°C, and wherein the heat activated adhesive layer of the TGP sheet can be heat laminated to a polyolefin-based layer or a layer of poly(ethylene-vinyl alcohol) to form a laminated article, such that the carrier film can be removed from the laminated article without delamination of the bond between the heat activated adhesive and the layer of polypropylene or poly(ethylene-vinyl alcohol).

10. The TGP sheet of claim 9, wherein the chlorinated thermoplastic resin comprises a chlorinated olefinic polymer.

11. The TGP sheet of claim 9, wherein the chlorinated thermoplastic resin comprises a chlorinated polypropylene.

12. The TGP sheet of claim 9, wherein the acrylic resin comprises a hydroxyl -functional acrylic liquid polymer.

13. The TGP sheet of claim 9, comprising a) 49 - 99.5 parts by weight of chlorinated thermoplastic resin; b) 0 - 50 parts by weight of a halogen-free modified polyolefin-based resin; c) 2.5 - 12.5 parts by weight of an acrylic resin with a Tg less than or equal to -30°C; and d) 3.7 - 10 parts by weight of at least one isocyanate -functional crosslinker.

14. The TGP sheet of claim 9, wherein the carrier film comprises a multi-layer adhesive comprising: a release liner with at least one release surface; a second adhesive layer, disposed on the surface of the release liner, wherein the second adhesive layer comprises a (meth)acrylate-based adhesive layer; and a vapor-deposited metal layer disposed on the second adhesive layer, wherein the vapor- deposited metal layer is in contact with the thermally adherable thermoplastic resin layer.

15. The TGP sheet of claim 9, wherein the color layer comprises multiple layers, wherein the multiple layers comprise color layers, patterned layers or both, and wherein the multiple layers if color may be the same color or different colors.

16. The method of making a multi-layer film article comprising: preparing a TGP (Transfer Gravure Printing) sheet, comprising: providing a carrier film; and depositing a thermally adherable thermoplastic resin composition on the carrier film and drying the thermally adherable thermoplastic resin composition to form a thermally adherable thermoplastic resin layer; depositing a color solution comprising a pigment in a binder on the thermally adherable thermoplastic resin layer to form a color layer; and forming a heat activated adhesive composition on the color layer, wherein forming the heat activated adhesive layer comprises depositing an adhesive solution on the colorlayer and drying the adhesive solution to form the heat activated adhesive layer, wherein the adhesive solution comprises an adhesive composition and at least one solvent, wherein the adhesive composition comprises: a) a chlorinated thermoplastic resin; b) a halogen-free modified polyolefin-based resin; c) an acrylic resin with a Tg less than or equal to -30°C; and d) at least one crosslinker comprising an isocyanate-functional crosslinker, wherein the heat activated adhesive layer has impact resistance at -30°C; preparing a top layer article, wherein the top layer article comprises a multi-layer film with at least 2 layers comprising a polyolefin-based film and a support film; heat laminating the top layer to the TGP sheet by contacting the support layer of the top layer to the heat activated adhesive layer of the TGP sheet and applying heat and pressure to form an intermediate article; removing the carrier film from the intermediate article to expose the thermally adherable thermoplastic resin layer; providing an adhesive article with a second adhesive layer disposed on a release liner; heat laminating the second adhesive layer to the intermediate article such that the phenoxy adhesive layer contacts the second adhesive layer and applying heat and pressure to form a secondary article; and heating and contacting the polyolefin-based film surface of the top layer of the secondary article to an embossing tool to impart a structured surface to the top layer.

17. The method of claim 16, wherein the top layer further comprises a second polyolefin- based layer in contact with the support film.

18. The method of claim 16, wherein heat laminating the top film to the TGP sheet by applying heat and pressure comprises passing the top layer / TGP sheet laminate through a heated nip roller.

19. The method of claim 16, wherein the adhesive article with a second adhesive layer disposed on a release liner further comprises a vapor-deposited layer of metal disposed on the second adhesive layer.

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