Coating alternative film and method of decomposing article

Abstract

To provide a coating alternative film capable of readily separating from a decorative target.SOLUTION: A coating alternative film to be adhered to a decorative target as a substitute for coating, comprises a decorative layer, a thermoplastic base film layer laminated on one side of the decorative layer, and an adhesive layer laminated on the side of the thermoplastic base film layer opposite to the decorative layer, and the adhesive layer is such that its adhesion decreases due to foaming inside caused by at least one of heating or irradiation with active energy rays, thereby enabling separation of the coating alternative film from the decorative target.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a paint replacement film and a method for dismantling an article having the paint replacement film. [Background technology]

[0002] The exteriors and interiors of automobiles, railroad cars, and aircraft, as well as home appliances and furniture, are usually finished with paint. Painting is done by spraying a liquid paint onto the object to be decorated or by immersing the object in a liquid paint, and then the paint is dried to complete the finish.

[0003] For example, when coloring the exterior of an automobile body, a typical process involves applying an anti-rust electrodeposition primer coat, then applying an undercoat after it dries to prevent scratches and improve color development, and then applying a topcoat containing a colorant after the undercoat has dried, followed by drying to complete the finish. In this way, coloring is usually achieved by spraying or immersing the liquid paint three times.

[0004] As mentioned above, the painting process requires a drying process in which liquid paint is placed in a heating oven to dry, which requires a large amount of heat energy and is a cause of CO2 emissions.In the automotive industry, it is said that approximately 30% of the CO2 emitted in automobile manufacturing comes from the painting process, and there has been growing interest in decorative films (paint alternative films) as a material to replace paint.

[0005] As an example of a method for manufacturing a decorated molded body that does not require the application of liquid paint, Patent Document 1 proposes a method that uses a decorative film that is applied to outdoor molded bodies such as automobile bodies and automobile exterior parts, and that is laminated with a thermoplastic resin layer, an uncured ultraviolet-curable hard coat layer, and a release film layer.

[0006] Furthermore, Patent Document 2 discloses an acrylic resin film suitable for lamination and in-mold forming as an example of a film to replace paint for use in high-end furniture materials and interior materials for high-end automobiles.

[0007] Furthermore, Patent Document 3 discloses a decorative film that can be applied easily using a simple process and can provide an appearance with good smoothness and gloss equivalent to that achieved by a coating process using a liquid paint. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 4627099 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-080678 [Patent Document 3] Japanese Patent Publication No. 2020-196213 Summary of the Invention [Problem to be solved by the invention]

[0009] In recent years, in order to contribute to the realization of a sustainable society, the development of paint-replacement films that can be easily separated from decorative objects by specific external factors has been considered from the perspective of recycling. However, existing paint-replacement films have insufficient peelability, and further improvement is required.

[0010] The present invention has been made in view of the above circumstances, and has as its object to provide a paint substitute film that can be easily separated from an object to be decorated. [Means for solving the problem]

[0011] In order to achieve the above-mentioned object, firstly, the present invention provides a paint substitute film that is attached to an object to be decorated as a paint substitute, the paint substitute film comprising a decorative layer, a thermoplastic base film layer laminated on one side of the decorative layer, and an adhesive layer laminated on the side of the thermoplastic base film layer opposite the decorative layer, the adhesive layer foaming internally when heated or irradiated with active energy rays, thereby reducing its adhesive strength, thereby enabling the paint substitute film to be separated from the object to be decorated (Invention 1).

[0012] In the above invention (Invention 1), it is preferable that the thermoplastic base film layer is composed of a material containing at least one selected from the group consisting of acrylic resin, polyurethane, polyvinyl chloride, vinyl acetate resin, and polyvinyl alcohol (Invention 2).

[0013] In the above inventions (Inventions 1 and 2), the pressure-sensitive adhesive layer contains, as monomer units constituting a polymer, a (meth)acrylic acid alkyl ester (a1) and a copolymer represented by the following formula (1): [ka] and a catalyst (B) capable of performing a nucleophilic attack on a carbon atom constituting a carbonyl group in the ethylene carbonate structure by at least one of heating and irradiation with active energy rays, thereby decomposing the ethylene carbonate structure and releasing carbon dioxide (Invention 3).

[0014] In the above inventions (Inventions 1 to 3), it is preferable that the paint substitute film has a barrier layer laminated directly or indirectly to the thermoplastic base film layer at least in one of the positions between the decorative layer and the thermoplastic base film layer and between the thermoplastic base film layer and the adhesive layer (Invention 4).

[0015] In the above invention (Invention 4), the barrier layer is preferably at least one of a gas barrier film formed from a gas barrier resin, a metal vapor-deposited film formed by vapor-depositing a metal on at least one surface of a base film, a film with an inorganic oxide layer formed on at least one surface of a base film, a gas barrier coated film formed by applying a gas barrier coating to at least one surface of a base film, a metal foil, and an inorganic oxide layer formed from an inorganic oxide (Invention 5).

[0016] In the above inventions (Inventions 1 to 5), the thickness of the thermoplastic base film layer is preferably 50 μm or more and 150 μm or less (Invention 6).

[0017] In the above inventions (Inventions 1 to 6), the thickness of the pressure-sensitive adhesive layer is preferably 10 μm or more and 100 μm or less (Invention 7).

[0018] In the above inventions (Inventions 1 to 7), it is preferable that a protective film be provided on the side of the decorative layer opposite to the thermoplastic base film layer (Invention 8).

[0019] Secondly, the present invention provides a method for dismantling an article in which the adhesive side of the paint substitute film (Inventions 1 to 8) is attached to at least a portion of the surface of the object to be decorated, the method comprising applying an external stimulus of at least one of heating and irradiation with active energy rays to the paint substitute film to foam the inside of the adhesive layer, thereby separating the paint substitute film from the object to be decorated (Invention 9). [Effects of the Invention]

[0020] The paint substitute film according to the present invention can be easily separated from the object to be decorated. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described. The paint substitute film according to this embodiment is attached to an object to be decorated as a paint substitute, and includes a decorative layer, a thermoplastic base film layer laminated on one side of the decorative layer, and a pressure-sensitive adhesive layer laminated on the other side of the thermoplastic base film layer opposite the decorative layer.

[0022] The paint substitute film according to this embodiment includes an adhesive layer, which allows it to adhere well to the object to be decorated. Furthermore, the paint substitute film according to this embodiment includes a decorative layer, which allows it to easily impart a desired decoration to the object to be decorated. In particular, the paint substitute film according to this embodiment does not require the multiple steps required for general painting, which effectively reduces CO2 emissions. Furthermore, the paint substitute film according to this embodiment includes a thermoplastic base film layer, which absorbs the unevenness of the surface of the object to be decorated and smooths the surface of the decorative layer, thereby imparting to the surface of the decorative layer an appearance with smoothness and gloss similar to that of a painted surface that is painted through multiple steps.

[0023] Furthermore, in the paint substitute film according to this embodiment, the pressure-sensitive adhesive layer foams internally upon heating or irradiation with active energy rays, reducing its adhesive strength, thereby enabling the paint substitute film to be separated from the object to be decorated. This makes it possible to more reliably separate the decoration (paint substitute film) from the object to be decorated by the extremely simple means of heating or irradiation with active energy rays, compared to peeling off the paint from a commonly painted object to be decorated.

[0024] The paint substitute film according to this embodiment can be attached to an already formed object to be decorated, as in the case of producing the exterior of an automobile, or can be attached to the object to be decorated at the same time as molding it in in-mold molding, as in the case of producing the interior of an automobile.

[0025] 1.Decorative layer The decorative layer in this embodiment is not particularly limited, and any conventionally known layer can be used as long as it can express the desired decoration with a pattern, letters, etc. The decorative layer may be provided on the entire surface of one side of the thermoplastic base film layer, or may be provided on a part of the one side.

[0026] Examples of decorative layers include those in which ink constituting a predetermined decoration is printed on one side of a thermoplastic base film layer, those in which paint constituting a predetermined decoration is applied to said one side, those in which ink or paint constituting a predetermined decoration is transferred to said one side from a transfer sheet, and those in which decoration is formed on said one side by vapor deposition or sputtering, etc. The inks and paints constituting such decorative layers can be those commonly used in paint replacement films.

[0027] The thickness of the decorative layer is usually about 0.01 to 100 μm, preferably about 0.1 to 60 μm, but can be changed appropriately depending on the application.

[0028] 2. Thermoplastic base film layer The thermoplastic base film layer in this embodiment is not particularly limited as long as it is a film whose main material is a thermoplastic resin, and any conventionally known film can be used.

[0029] Examples of the thermoplastic resin include acrylic resin, polyurethane, polyvinyl chloride, vinyl acetate resin, polyvinyl alcohol, etc. Among these, the thermoplastic base film layer in the present embodiment is preferably made of a material containing at least one selected from the group consisting of polyurethane and polyvinyl chloride.

[0030] The material constituting the thermoplastic base film layer in this embodiment may contain other components in addition to the above-mentioned thermoplastic resin. Examples of such components include flame retardants, plasticizers, antistatic agents, lubricants, antioxidants, infrared absorbers, ultraviolet absorbers, ion scavengers, etc. In addition, the thermoplastic base film layer in this embodiment may be obtained by a general resin film manufacturing method.

[0031] The thickness of the thermoplastic base film layer in this embodiment is preferably 50 μm or more, and particularly preferably 70 μm or more. A thickness of 50 μm or more makes the paint substitute film of this embodiment more likely to have sufficient strength. Furthermore, the thickness of the thermoplastic base film layer is preferably 150 μm or less, and particularly preferably 100 μm or less. A thickness of 150 μm or less makes the paint substitute film of this embodiment easier to handle.

[0032] 3. Adhesive layer As described above, the adhesive layer in this embodiment is not particularly limited as long as it is one that undergoes foaming inside and a decrease in adhesive strength upon at least one of heating and irradiation with active energy rays, thereby enabling the paint substitute film of this embodiment to be separated from the object to be decorated.

[0033] The type of adhesive constituting the adhesive layer in this embodiment is not particularly limited, and conventionally known adhesives can be used. For example, acrylic adhesives, silicone adhesives, urethane adhesives, rubber adhesives, etc. can be used as the adhesive. Among them, acrylic adhesives are preferred because they can easily achieve good adhesion.

[0034] When the pressure-sensitive adhesive layer in this embodiment is composed of an acrylic pressure-sensitive adhesive, the pressure-sensitive adhesive layer contains, as a monomer unit constituting a polymer, a (meth)acrylic acid alkyl ester (a1) and a compound represented by the following formula (1): [ka] a (meth)acrylic acid ester copolymer (A) containing an ethylene carbonate-containing monomer (a2) having an ethylene carbonate structure represented by the formula: a catalyst (B) capable of nucleophilically attacking a carbon atom constituting a carbonyl group in an ethylene carbonate structure by at least one of heating and irradiation with active energy rays, thereby decomposing the ethylene carbonate structure and releasing carbon dioxide; It is preferable that the adhesive composition is formed from a pressure-sensitive adhesive composition containing the above-mentioned compound. In this specification, (meth)acrylic acid means both acrylic acid and methacrylic acid. The same applies to other similar terms. Furthermore, the term "copolymer" also includes the concept of "polymer."

[0035] The catalyst (B) in this embodiment is not particularly limited as long as it is capable of nucleophilic attack on the carbon atoms constituting the carbonyl groups in the ethylene carbonate structure, thereby decomposing the ethylene carbonate structure and releasing carbon dioxide. Examples of catalysts include nucleophilic anion generators capable of generating nucleophilic anions, and particularly nucleophilic anion generators capable of generating nucleophilic anions in response to a specific external stimulus. When attempting to separate the paint substitute film of this embodiment from the object to be decorated, the pressure-sensitive adhesive layer is subjected to at least one of heating and active energy ray irradiation. This generates nucleophilic anions from the catalyst (B) within the pressure-sensitive adhesive layer. The generated nucleophilic anions then nucleophilically attack the carbon atoms constituting the carbonyl groups in the ethylene carbonate structure, thereby decomposing the ethylene carbonate structure and releasing carbon dioxide. The carbon dioxide thus generated accumulates as a gas at the interface between the pressure-sensitive adhesive layer and the object to be decorated, thereby separating the paint substitute film from the object to be decorated. As a result, the paint substitute film can be very easily peeled off from the object to be decorated without the need to apply a physical force to peel the paint substitute film off from the object to be decorated. Furthermore, as described above, such peeling occurs when a treatment such as heating or irradiation with active energy rays is performed, and therefore, peeling can be easily achieved at any desired timing.

[0036] Examples of the nucleophilic anion include fluoride ion (F-), chloride ion (Cl-), bromide ion (Br-), iodide ion (I-), hydroxide ion (OH-), etc., among which, fluoride ion (F-) and bromide ion (Br-) are preferred, and fluoride ion (F-) is particularly preferred. Examples of the cation constituting the nucleophilic anion generator include quaternary ammonium cation, imidazolium cation, pyrrolidinium cation, pyridinium cation, piperidinium cation, phosphonium cation, alkali metal ion, alkaline earth metal ion, etc., among which, quaternary ammonium cation is preferred.

[0037] Specific preferred examples of the nucleophilic anion generator include tetrabutylammonium fluoride (TBAF), tetrabutylammonium bromide (TBAB), 1-ethyl-3-methylimidazolium bromide, tetrabutylphosphonium bromide, sodium hydroxide, etc. Among these, tetrabutylammonium fluoride (TBAF) and tetrabutylammonium bromide (TBAB) are preferred. These nucleophilic anion generators may be used alone or in combination of two or more.

[0038] (1) (Meth)acrylic acid ester copolymer (A) As described above, the (meth)acrylic acid ester copolymer (A) in the present embodiment preferably contains, as a monomer unit constituting the polymer, a (meth)acrylic acid alkyl ester (a1) in which the alkyl group has 1 to 12 carbon atoms, and particularly preferably contains a (meth)acrylic acid alkyl ester (a1) in which the alkyl group has 1 to 12 carbon atoms.

[0039] Examples of (meth)acrylic acid alkyl esters (a1) having an alkyl group containing 1 to 12 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-decyl (meth)acrylate, and n-dodecyl (meth)acrylate. When the (meth)acrylic acid ester copolymer (A) contains a (meth)acrylic acid alkyl ester (a1) having an alkyl group containing 1 to 12 carbon atoms as a monomer constituting the polymer, the resulting pressure-sensitive adhesive can exhibit desired adhesiveness. From this perspective, among the above-mentioned (meth)acrylic acid alkyl esters, it is preferable to use a (meth)acrylic acid alkyl ester having an alkyl group containing 1 to 8 carbon atoms, and particularly n-butyl (meth)acrylate is preferably used, with n-butyl acrylate being particularly preferred. These may be used alone or in combination of two or more.

[0040] The (meth)acrylic acid ester copolymer (A) preferably contains the above-mentioned (meth)acrylic acid alkyl ester (a1) as a monomer unit constituting the polymer in an amount of 60% by mass or more, particularly preferably 70% by mass or more, and even more preferably 80% by mass or more. The (meth)acrylic acid ester copolymer (A) preferably contains the above-mentioned (meth)acrylic acid alkyl ester (a1) as a monomer unit constituting the polymer in an amount of 99.9% by mass or less, particularly preferably 99.5% by mass or less, and even more preferably 99.0% by mass or less. By ensuring that the content of the (meth)acrylic acid alkyl ester (a1) is within the above-mentioned range, the resulting pressure-sensitive adhesive layer is more likely to exhibit the desired adhesive strength.

[0041] As described above, the (meth)acrylic acid ester copolymer (A) preferably contains an ethylene carbonate-containing monomer (a2) containing an ethylene carbonate structure as a monomer unit constituting the polymer. When the (meth)acrylic acid ester copolymer (A) is composed of the ethylene carbonate-containing monomer (a2), the pressure-sensitive adhesive composition of this embodiment contains an ethylene carbonate structure as a side chain of the (meth)acrylic acid ester copolymer (A). The ethylene carbonate-containing monomer (a2) generally has a fast polymerization rate, and therefore the resulting (meth)acrylic acid ester copolymer (A) tends to have block-like portions formed in which units derived from the monomer are concentrated. This makes the (meth)acrylic acid ester copolymer (A) more likely to effectively generate carbon dioxide gas.

[0042] The ethylene carbonate-containing monomer (a2) is not particularly limited as long as it contains an ethylene carbonate structure and can undergo a polymerization reaction with the above-mentioned (meth)acrylic acid alkyl ester (a1) having an alkyl group with 1 to 12 carbon atoms.

[0043] A preferred example of the ethylene carbonate-containing monomer (a2) is a (meth)acrylic acid ester having a structure in which an organic group having an ethylene carbonate structure and a (meth)acryloyloxy group are bonded. Examples of such (meth)acrylic acid esters include those represented by the following formula (2): [ka] or an acrylic acid ester represented by the following formula (3): [ka] In both formula (2) and formula (3), n represents an integer of 0 or more. Among the (meth)acrylic acid esters represented by formula (2) and formula (3), (meth)acrylic acid esters in which n=1 are preferred, and acrylic acid esters in which n=1 in formula (2) are particularly preferred, from the viewpoint of facilitating the release of carbon dioxide gas. The ethylene carbonate-containing monomer (a2) may be used singly or in combination of two or more.

[0044] When the (meth)acrylic acid ester copolymer (A) contains the above-mentioned ethylene carbonate-containing monomer (a2) as a monomer unit constituting the polymer, it preferably contains 10% by mass or more of the ethylene carbonate-containing monomer (a2), particularly preferably 20% by mass or more, and even more preferably 30% by mass or more of the ethylene carbonate-containing monomer (a2). When the (meth)acrylic acid ester copolymer (A) contains the above-mentioned ethylene carbonate-containing monomer (a2) as a monomer unit constituting the polymer, it preferably contains 70% by mass or less of the ethylene carbonate-containing monomer (a2), particularly preferably 60% by mass or less, and even more preferably 50% by mass or less of the ethylene carbonate-containing monomer (a2). When the content of the ethylene carbonate-containing monomer (a2) is 10% by mass or more, the pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition of this embodiment efficiently generates carbon dioxide gas due to the action of fluoride ions generated from the fluoride ion generator (B), thereby making it easier to peel the paint substitute film including the pressure-sensitive adhesive layer from the object to be decorated. Furthermore, when the content of the ethylene carbonate-containing monomer (a2) is 70 mass% or less, it becomes easier to ensure a sufficient content of the (meth)acrylic acid alkyl ester (a1), and it becomes easier to achieve the desired adhesive performance in the paint replacement film.

[0045] The (meth)acrylic acid ester copolymer (A) also preferably contains a hydroxy group-containing monomer (a3) ​​as a monomer unit constituting the polymer. When the (meth)acrylic acid ester copolymer (A) contains a hydroxy group-containing monomer (a3) ​​as a monomer unit constituting the polymer, the (meth)acrylic acid ester copolymer (A) contains a hydroxy group in the side chain. Here, when the pressure-sensitive adhesive composition of this embodiment contains a crosslinking agent (C) (particularly a polyisocyanate-based compound) described below, the hydroxy group functions as a reaction site with the crosslinking agent (C), making it easy to obtain a well-crosslinked pressure-sensitive adhesive.

[0046] Preferred examples of the hydroxy group-containing monomer (a3) ​​include (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyheptyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate. Among these, 2-hydroxyethyl (meth)acrylate is preferred, and 2-hydroxyethyl acrylate is particularly preferred, from the viewpoint of excellent reactivity with the above-mentioned crosslinking agent (C). These may be used alone or in combination of two or more.

[0047] The (meth)acrylic acid ester copolymer (A) preferably contains 1% by mass or more, particularly 3% by mass or more, and even more preferably 5% by mass or more, of the hydroxy group-containing monomer (a3) ​​as a monomer unit constituting the polymer. The (meth)acrylic acid ester copolymer (A) preferably contains 20% by mass or less, particularly 15% by mass or less, and even more preferably 10% by mass or less, of the hydroxy group-containing monomer (a3) ​​as a monomer unit constituting the polymer. A hydroxy group-containing monomer (a3) ​​content of 1% by mass or more facilitates the reaction with the crosslinking agent (C) described above. A hydroxy group-containing monomer (a3) ​​content of 20% by mass or less facilitates the sufficient content of the (meth)acrylic acid alkyl ester (a1), thereby making it easier to achieve the desired adhesive strength in the paint substitute film described above.

[0048] If desired, the (meth)acrylic acid ester copolymer (A) may contain, as a monomer unit constituting the copolymer, a monomer other than the above-mentioned (meth)acrylic acid alkyl ester (a1), ethylene carbonate-containing monomer (a2), and hydroxy group-containing monomer (a3).

[0049] Examples of such other monomers include monomers having a reactive group capable of reacting with a crosslinking agent, such as a carboxy group, an amino group, or an aziridinyl group. Particularly, examples of monomers containing a carboxy group include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Furthermore, examples of monomers containing an amino group include aminoethyl (meth)acrylate and n-butylaminoethyl (meth)acrylate. These monomers can be used alone or in combination of two or more.

[0050] Further examples of the other monomers mentioned above include alkoxyalkyl group-containing (meth)acrylic acid esters such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate; aromatic ring-containing (meth)acrylic acid esters such as phenyl (meth)acrylate; non-crosslinkable acrylamides such as acrylamide and methacrylamide; non-crosslinkable tertiary amino group-containing (meth)acrylic acid esters such as N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate; vinyl acetate; styrene, etc. These may be used alone or in combination of two or more.

[0051] The polymerization mode of the (meth)acrylic acid ester copolymer (A) may be a random copolymer or a block copolymer. The (meth)acrylic acid ester copolymer (A) can be obtained by copolymerizing the above-mentioned monomers by a conventional method. For example, it can be produced by polymerization using an emulsion polymerization method, a solution polymerization method, a suspension polymerization method, a bulk polymerization method, an aqueous solution polymerization method, or the like. Among these, from the viewpoints of stability during polymerization and ease of handling during use, it is preferable to produce it by a solution polymerization method carried out in an organic solvent.

[0052] For example, the (meth)acrylic acid ester copolymer (A) can be produced by dissolving a mixture of monomer components in an organic solvent, adding a conventionally known azo-based polymerization initiator such as azobisisobutyronitrile, 2,2′-azobis(2-aminodipropane) dihydrochloride, or 4,4′-azobis(4-cyanovaleric acid), or a peroxide-based polymerization initiator such as benzoyl peroxide, and carrying out radical polymerization.

[0053] The weight average molecular weight of the (meth)acrylic acid ester copolymer (A) is preferably 50,000 or more, particularly preferably 80,000 or more, and even more preferably 100,000 or more. Furthermore, the weight average molecular weight is preferably 2,000,000 or less, particularly preferably 1,700,000 or less, and even more preferably 1,500,000 or less. When the weight average molecular weight of the (meth)acrylic acid ester copolymer (A) is within the above range, it becomes easy to form a pressure-sensitive adhesive layer having the desired adhesive strength. The weight average molecular weight in this specification is a value measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

[0054] The pressure-sensitive adhesive composition of the present embodiment may contain one or more of the above-described (meth)acrylic acid ester copolymers (A). The pressure-sensitive adhesive composition of the present embodiment may contain another (meth)acrylic acid ester polymer in addition to the above-described (meth)acrylic acid ester copolymer (A).

[0055] (2) Fluoride ion generator (B) The fluoride ion generator (B) is a compound that generates fluoride ions (F - ) and the fluoride ions can be used to sufficiently release carbon dioxide gas from the ethylene carbonate structure contained in the pressure-sensitive adhesive composition of the present embodiment, so long as the fluoride ions can be used to sufficiently release carbon dioxide gas from the ethylene carbonate structure contained in the pressure-sensitive adhesive composition of the present embodiment.

[0056] Preferred examples of the fluoride ion generator (B) include salts with fluoride ions as the anion, such as quaternary alkylammonium fluorides such as tetra-n-butylammonium fluoride (TBAF) and tetramethylammonium fluoride; alkali metal fluoride salts such as hydrofluoric acid, sodium fluoride and potassium fluoride; amine hydrofluorides such as monoethylamine hydrofluoride and triethylamine trihydrofluoride; pyridine hydrofluoric acid, ammonium fluoride, H2SiF6, HBF4 and HPF6. Among these, it is preferable to use quaternary alkylammonium fluorides, and it is particularly preferable to use tetra-n-butylammonium fluoride (TBAF), from the viewpoint of easily releasing fluoride ions while ensuring the desired performance of the paint replacement film.

[0057] The fluoride ion generating agent (B) can be used alone or in combination of two or more.

[0058] When the (meth)acrylic acid ester copolymer (A) has an ethylene carbonate structure, the content of the fluoride ion generator (B) in the pressure-sensitive adhesive composition of this embodiment is preferably 0.01 parts by mass or more, particularly preferably 0.03 parts by mass or more, even more preferably 0.75 parts by mass or more, and most preferably 1 part by mass or more, per 100 parts by mass of the (meth)acrylic acid ester copolymer (A). Furthermore, the content is preferably 10 parts by mass or less, particularly preferably 7 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the (meth)acrylic acid ester copolymer (A). By including the fluoride ion generator (B) in an amount of 0.01 parts by mass or more, fluoride ions can be effectively generated in the pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition of this embodiment. This allows for good generation of carbon dioxide gas from the pressure-sensitive adhesive layer, thereby making it easier to peel the paint substitute film including the pressure-sensitive adhesive layer from the object to be decorated. Furthermore, when the content of the fluoride ion generating agent (B) is 10 parts by mass or less, it becomes easier to maintain a good surface condition when forming a coating film using the pressure-sensitive adhesive composition of the present embodiment.

[0059] (3) Crosslinking agent (C) The pressure-sensitive adhesive composition of this embodiment also preferably contains a crosslinking agent (C). By containing the crosslinking agent (C), a crosslinking reaction between the (meth)acrylic acid ester copolymer (A) and the crosslinking agent (C) can occur, and a three-dimensional network structure can be favorably formed in the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of this embodiment. This makes it easy to form a pressure-sensitive adhesive layer with the desired adhesive strength.

[0060] The crosslinking agent (C) is not particularly limited as long as it can cause a crosslinking reaction with the (meth)acrylic acid ester copolymer (A), and examples thereof include polyisocyanate compounds, epoxy compounds, metal chelate compounds, polyimine compounds such as aziridine compounds, melamine resins, urea resins, dialdehydes, methylol polymers, metal alkoxides, metal salts, etc. Among these, polyisocyanate compounds or epoxy compounds are preferred, and polyisocyanate compounds are particularly preferred, because the crosslinking reaction is easily controlled.

[0061] The polyisocyanate compound is a compound having two or more isocyanate groups per molecule. Specific examples include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate; and their biurets, isocyanurates, and adducts obtained by reaction with low-molecular-weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, trimethylolpropane-modified tolylene diisocyanate is preferred.

[0062] Examples of epoxy compounds include 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylylenediamine, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidylaniline, and diglycidylamine.

[0063] When the pressure-sensitive adhesive composition of this embodiment contains a crosslinking agent (C), the content of the crosslinking agent (C) is preferably 0.05 parts by mass or more, particularly preferably 0.1 parts by mass or more, and even more preferably 0.15 parts by mass or more, per 100 parts by mass of the (meth)acrylic acid ester copolymer (A). Furthermore, the content is preferably 1 part by mass or less, particularly preferably 0.9 parts by mass or less, and even more preferably 0.8 parts by mass or less, per 100 parts by mass of the (meth)acrylic acid ester copolymer (A). When the content of the crosslinking agent (C) is within the above-mentioned range, the crosslinking reaction between the (meth)acrylic acid ester copolymer (A) and the crosslinking agent (C) occurs appropriately, thereby facilitating the formation of a pressure-sensitive adhesive layer with the desired adhesive strength.

[0064] (4) Ethylene carbonate-containing components The pressure-sensitive adhesive layer in this embodiment may be composed of a pressure-sensitive adhesive composition containing a component containing an ethylene carbonate structure (ethylene carbonate-containing component) other than the above-mentioned (meth)acrylic acid ester copolymer (A). For example, the pressure-sensitive adhesive layer in this embodiment may be formed from a pressure-sensitive adhesive composition containing a (meth)acrylic acid ester copolymer not containing an ethylene carbonate structure, the above-mentioned fluoride ion generating agent (B), the above-mentioned crosslinking agent (C), and an ethylene carbonate-containing component.

[0065] The ethylene carbonate-containing component is not particularly limited as long as it has an ethylene carbonate structure, and examples thereof include ethylene carbonate, the above-mentioned hydroxy group-containing monomer (a3) ​​alone, and oligomers containing the hydroxy group-containing monomer (a3) ​​as a monomer unit constituting a copolymer.

[0066] When the pressure-sensitive adhesive composition of this embodiment contains an ethylene carbonate-containing component, the content of the ethylene carbonate-containing component is preferably 3 parts by mass or more, particularly preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, per 100 parts by mass of the (meth)acrylic acid ester copolymer (A). Furthermore, the content is preferably 70 parts by mass or less, particularly preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less, per 100 parts by mass of the (meth)acrylic acid ester copolymer (A). When the content of the ethylene carbonate-containing component is 3 parts by mass or more, the pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition of this embodiment is effectively affected by the action of fluoride ions generated from the fluoride ion generator (B) to effectively generate carbon dioxide gas, thereby making it easier to peel a pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer from an adherend. Furthermore, when the content of the ethylene carbonate-containing component is 70 parts by mass or less, a good surface condition is more easily maintained when a coating film is formed using the pressure-sensitive adhesive composition of this embodiment.

[0067] (5) Other ingredients The pressure-sensitive adhesive composition of the present embodiment may contain, in addition to the above components, various additives such as coloring materials such as dyes and pigments, flame retardants, fillers, plasticizers, and antistatic agents.

[0068] (6) Method for producing pressure-sensitive adhesive composition The pressure-sensitive adhesive composition of this embodiment can be produced by producing a (meth)acrylic acid ester copolymer (A), and mixing the resulting (meth)acrylic acid ester copolymer (A) with a fluoride ion generating agent (B), and optionally a crosslinking agent (C), an ethylene carbonate-containing component, and additives. The mixing may be carried out in a solvent, in which case a coating liquid of the pressure-sensitive adhesive composition can be obtained.

[0069] Examples of the solvent include aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and ethylene chloride; alcohols such as methanol, ethanol, propanol, butanol, and 1-methoxy-2-propanol; ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, and cyclohexanone; esters such as ethyl acetate and butyl acetate; and cellosolve-based solvents such as ethyl cellosolve.

[0070] The concentration and viscosity of the coating solution prepared in this manner are not particularly limited as long as they are within a range that allows coating, and can be appropriately selected depending on the situation. For example, the adhesive composition is diluted so that the concentration is 10% by mass or more and 60% by mass or less. Note that, when preparing the coating solution, it is not necessary to add a solvent or the like, and as long as the adhesive composition has a viscosity that allows coating, it is not necessary to add a solvent.

[0071] (7) Thickness of adhesive layer In this embodiment, the thickness of the adhesive layer is preferably 10 μm or more, particularly preferably 20 μm or more, and even more preferably 30 μm or more. Furthermore, the thickness of the adhesive layer is preferably 100 μm or less. Having a thickness of 10 μm or more provides sufficient adhesive strength to the object to be decorated, allowing the paint substitute film to be better fixed to the object to be decorated, and also ensures that a sufficient amount of carbon dioxide gas is released when carbon dioxide gas is released from the adhesive layer. This allows sufficient carbon dioxide gas to accumulate at the interface between the paint substitute film and the object to be decorated, facilitating the peeling of the paint substitute film from the object to be decorated. Furthermore, having a thickness of 100 μm or less makes it easier to heat the adhesive layer and irradiate the adhesive layer with active energy rays, thereby facilitating the peeling of the paint substitute film from the object to be decorated.

[0072] 4. Barrier layer It is also preferable that the paint substitute film of this embodiment has a barrier layer laminated directly or indirectly to the thermoplastic base film layer at at least one position between the decorative layer and the thermoplastic base film layer and between the thermoplastic base film layer and the adhesive layer.

[0073] The paint substitute film according to this embodiment is provided with a barrier layer, which allows the desired barrier properties to be imparted to the object to be decorated to which the paint substitute film is attached. Furthermore, the presence of the barrier layer makes it easier for bubbles generated within the pressure-sensitive adhesive layer to remain within the paint substitute film, thereby facilitating more effective separation of the paint substitute film from the object to be decorated.

[0074] The configuration of the barrier layer is not particularly limited as long as it can contain foaming inside the pressure-sensitive adhesive layer, and any known barrier layer can be used.

[0075] Examples of the barrier layer of this embodiment include a gas barrier film formed from a gas barrier resin, a metal vapor-deposited film obtained by vapor-depositing a metal on at least one surface of a base film, a film with an inorganic oxide layer formed on at least one surface of a base film, a gas barrier coated film obtained by applying a gas barrier coating to at least one surface of a base film, a metal foil, an inorganic oxide layer formed from an inorganic oxide, etc. The barrier layer may be composed of one of these alone or a combination of two or more of them.

[0076] The gas barrier film formed from the gas barrier resin is preferably formed by extrusion molding or the like of at least one resin selected from rubber-based resins, polyester-based resins, polyolefin-based resins, cycloolefin-based resins, epoxy-based resins, ethylene-vinyl alcohol-based copolymers, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polychlorotrifluoroethylene, polyethylene fluoride, polytetrafluoroethylene, polyvinylidene fluoride, and the like.

[0077] The thickness of the gas barrier film is preferably 10 to 100 μm, and particularly preferably 30 to 50 μm.

[0078] The metal-deposited film obtained by depositing a metal on at least one surface of a base film is preferably, for example, a resin base film on which at least one metal selected from aluminum, magnesium, zinc, tin, etc. is deposited.

[0079] The thickness of the metal vapor-deposited film is preferably 10 to 100 μm, and particularly preferably 30 to 50 μm.

[0080] A film with an inorganic oxide layer, in which an inorganic oxide layer is formed on at least one surface of a substrate film, is preferably formed, for example, on at least one surface of a resin substrate film, with at least one inorganic oxide layer selected from inorganic oxides such as silicon oxide, aluminum oxide, magnesium oxide, zinc oxide, indium oxide, and tin oxide, inorganic nitrides such as silicon nitride, and inorganic oxynitrides such as silicon oxynitride and aluminum oxynitride. The inorganic oxide layer may be a coating film or a vapor-deposited film, with a vapor-deposited film being preferred. The substrate film is not particularly limited, and known resin substrates such as PET film can be used.

[0081] The thickness of the film on which the inorganic oxide layer is formed is preferably 10 to 100 μm, and particularly preferably 30 to 50 μm.

[0082] The gas barrier coated film obtained by applying a gas barrier coating to at least one surface of a base film is preferably obtained by coating at least one surface of a resin base film with at least one resin selected from rubber-based resins, polyester-based resins, polyolefin-based resins, cycloolefin-based resins, epoxy-based resins, ethylene-vinyl alcohol-based copolymers, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polychlorotrifluoroethylene, polyethylene fluoride, polytetrafluoroethylene, polyvinylidene fluoride, and the like.

[0083] The thickness of the gas barrier coating film is preferably 10 to 100 μm, and particularly preferably 30 to 50 μm.

[0084] Examples of the metal foil include aluminum, magnesium, zinc, tin, nickel, stainless steel, iron, copper, and titanium foils.

[0085] The inorganic oxide layer composed of an inorganic oxide is preferably at least one selected from inorganic oxides such as silicon oxide, aluminum oxide, magnesium oxide, zinc oxide, indium oxide, and tin oxide, inorganic nitrides such as silicon nitride, and inorganic oxynitrides such as silicon oxynitride and aluminum oxynitride. In the barrier layer of the present embodiment, the inorganic oxide layer composed of an inorganic oxide is more preferably laminated directly on the thermoplastic base film layer, and even more preferably laminated at a position between the thermoplastic base film layer and the pressure-sensitive adhesive layer.

[0086] 5. Protective film The paint substitute film according to this embodiment preferably also includes a protective film on the side of the decorative layer opposite the thermoplastic base film layer, which can prevent damage to the decorative layer and the surface of the object to be decorated to which the paint substitute film is attached.

[0087] The structure of the protective film is not particularly limited, and any known film can be used. For example, a film having a hard coat layer formed on the surface of a substrate film can be used.

[0088] The hard coat layer is preferably formed by curing a composition containing a curable component. Examples of the curable component include an active energy ray curable component and a thermosetting component. From the viewpoint of facilitating the formation of a desired hard coat layer, it is preferable to use an active energy ray curable component. Examples of the active energy ray curable component include a polyfunctional (meth)acrylate monomer, a (meth)acrylate prepolymer, and an active energy ray curable polymer.

[0089] The composition for forming the hard coat layer preferably contains an inorganic filler, examples of which include powders of silica, alumina, boehmite, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, boron nitride, zirconium oxide, etc., beads obtained by spheronizing these powders, single crystal fibers, and glass fibers.

[0090] In addition to the above-mentioned components, the composition for forming the hard coat layer may contain organic components such as a thermosetting resin or a thermoplastic resin, and additives such as a photopolymerization initiator, an antioxidant, an antistatic agent, a silane coupling agent, an antiaging agent, a thermal polymerization inhibitor, a colorant, a surfactant, a storage stabilizer, a plasticizer, a lubricant, and an antifoaming agent.

[0091] The thickness of the protective film is preferably 10 to 200 μm, and particularly preferably 30 to 100 μm.

[0092] 6.Release sheet In the paint substitute film of this embodiment, a release sheet may be laminated on the side of the adhesive layer opposite the thermoplastic base film layer (adhesive side) to protect that side until it is attached to the object to be decorated.

[0093] The release sheet may have any configuration, and may be, for example, a plastic film that has been subjected to a release treatment using a release agent or the like. Specific examples of such plastic films include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. Examples of the release agent that can be used include silicone-based, fluorine-based, long-chain alkyl, and rubber-based agents, and among these, silicone-based agents are preferred because they are inexpensive and provide stable performance.

[0094] 7.Manufacturing method of paint replacement film The method for producing the paint substitute film according to the present embodiment is not particularly limited as long as the layers constituting the paint substitute film can be laminated in the aforementioned order. For example, a paint substitute film can be obtained by laminating a decorative layer, a thermoplastic base film layer, a pressure-sensitive adhesive layer, and the like, each of which has been formed in advance, in a predetermined order.

[0095] The decorative layer may be formed directly on the thermoplastic base film layer by printing or applying ink or paint to one side of the thermoplastic base film layer, or a decorative layer formed independently of the thermoplastic base film layer may be laminated on one side of the thermoplastic base film layer.

[0096] As a method for forming the pressure-sensitive adhesive layer, for example, a coating liquid containing the pressure-sensitive adhesive composition described above and, if desired, a solvent or dispersion medium is prepared, and the coating liquid is applied to the release surface of the release sheet using a die coater, curtain coater, spray coater, slit coater, knife coater, or the like to form a coating film, and the coating film is dried, thereby forming the pressure-sensitive adhesive layer.

[0097] The thermoplastic base film layer and the adhesive layer can be integrated by bonding the adhesive layer side of the laminate of the adhesive layer and release sheet formed as described above to one side of the thermoplastic base film layer (particularly the side on which the decorative layer is not laminated).

[0098] 8. How to use paint replacement film The paint substitute film according to this embodiment can be used as a paint substitute by being attached to an object to be decorated, similar to conventional paint substitute films. In particular, the paint substitute film according to this embodiment can be attached to the surface of a molded product, such as the exterior of an automobile, to impart decoration thereto, and can also be used to impart decoration to a product simultaneously with molding by in-mold molding, such as the interior of an automobile.

[0099] The objects to be decorated with the paint substitute film according to this embodiment are not particularly limited, and examples thereof include the exterior and interior of automobiles, railway vehicles, aircraft, household electrical appliances, furniture, and the like.

[0100] As described above, the paint substitute film of this embodiment has an adhesive layer that foams internally when heated or exposed to active energy rays, reducing its adhesive strength, and therefore can be easily separated from the object to be decorated by the very simple means of heating or exposure to active energy rays.

[0101] Therefore, the paint substitute film according to the present embodiment is suitable for use in a method for dismantling an article in which the adhesive side of the paint substitute film according to the present embodiment is attached to at least a portion of the surface of an object to be decorated. The method includes applying an external stimulus of at least one of heating and irradiating with active energy rays to the paint substitute film to foam the inside of the adhesive layer, thereby separating the paint substitute film from the object to be decorated.

[0102] According to the above method, it is possible to more efficiently dispose of the object to be decorated to which the paint substitute film according to the present embodiment is attached. The above method is also effective when replacing the paint substitute film attached to the object to be decorated.

[0103] The heating means and conditions can be appropriately set depending on the composition of the pressure-sensitive adhesive layer and the state of the object to be decorated. Examples of heating means that can be used include a thermostatic oven, a hot air dryer, a hot plate, a near-infrared lamp, and a heating roller. The heating conditions are preferably, for example, a temperature of 100°C or higher and 250°C or lower for 5 seconds or longer and 30 minutes or shorter.

[0104] The irradiation of the above-mentioned active energy rays can also be appropriately set depending on the composition of the pressure-sensitive adhesive layer and the state of the object to be decorated. Examples of the active energy rays include ionizing radiation, i.e., ultraviolet rays and electron beams, but ultraviolet rays are preferred because irradiation equipment is relatively easy to install.

[0105] When ultraviolet light is used as the ionizing radiation, it is preferable to use near ultraviolet light containing ultraviolet light with a wavelength of about 200 to 380 nm for ease of handling. The light intensity of ultraviolet light is usually 50 mJ / cm. 2 It is preferable to set the dose to 100 mJ / cm or more, and particularly 100 mJ / cm 2 It is preferable that the dose is 200 mJ / cm or more, and more preferably 200 mJ / cm 2 The amount of ultraviolet light is preferably 2000 mJ / cm or more. 2 It is preferable that the dose is not more than 1700 mJ / cm 2 It is preferable that the intensity is 1400 mJ / cm or less, and more preferably 1400 mJ / cm 2 The irradiance of ultraviolet light is preferably 50 mW / cm or less. 2 It is preferable that the power is equal to or higher than 100 mW / cm 2 It is preferable that the intensity is 200 mW / cm or more, and more preferably 200 mW / cm 2 The irradiance of ultraviolet light is preferably 500 mW / cm or more. 2 It is preferable that the power consumption is 450 mW / cm or less, and particularly 450 mW / cm 2 It is preferable that the intensity is 400 mW / cm or less, and more preferably 400 mW / cm 2 The ultraviolet light source is not particularly limited, and examples thereof include a high-pressure mercury lamp, a metal halide lamp, and a UV-LED.

[0106] The above-described embodiments have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention. [Industrial Applicability]

[0107] The paint substitute film of the present invention can be suitably used to decorate various products as a substitute for painting.

Claims

1. A paint substitute film that is attached to an object to be decorated as a paint substitute, The paint substitute film comprises a decorative layer, a thermoplastic base film layer laminated on one side of the decorative layer, and a pressure-sensitive adhesive layer laminated on the thermoplastic base film layer on the side opposite to the decorative layer, The adhesive layer is foamed internally by at least one of heating and irradiation with active energy rays, thereby reducing adhesive strength, thereby enabling the paint substitute film to be separated from the object to be decorated. A paint replacement film characterized by:

2. 2. The paint substitute film according to claim 1, wherein the thermoplastic base film layer is made of a material containing at least one selected from the group consisting of acrylic resin, polyurethane, polyvinyl chloride, vinyl acetate resin, and polyvinyl alcohol.

3. The pressure-sensitive adhesive layer is The monomer units constituting the polymer include (meth)acrylic acid alkyl ester (a1) and a monomer represented by the following formula (1): 【Chemical 1】 a (meth)acrylic acid ester copolymer (A) containing an ethylene carbonate-containing monomer (a2) having an ethylene carbonate structure represented by the formula: a catalyst (B) capable of nucleophilically attacking a carbon atom constituting a carbonyl group in an ethylene carbonate structure by at least one of heating and irradiation with active energy rays, thereby decomposing the ethylene carbonate structure and releasing carbon dioxide; 2. The paint replacement film according to claim 1, which is formed from a pressure-sensitive adhesive composition containing:

4. The paint substitute film according to claim 1, characterized in that the paint substitute film has a barrier layer laminated directly or indirectly to the thermoplastic base film layer at at least one position between the decorative layer and the thermoplastic base film layer and between the thermoplastic base film layer and the adhesive layer.

5. 5. The paint substitute film according to claim 4, wherein the barrier layer is at least one of a gas barrier film formed from a gas barrier resin, a metal vapor-deposited film formed by vapor-depositing a metal on at least one surface of a base film, a film with an inorganic oxide layer formed on at least one surface of a base film, a gas barrier coated film formed by applying a gas barrier coating to at least one surface of a base film, a metal foil, and an inorganic oxide layer formed from an inorganic oxide.

6. 2. The paint substitute film according to claim 1, wherein the thickness of the thermoplastic base film layer is 50 μm or more and 150 μm or less.

7. 2. The paint substitute film according to claim 1, wherein the thickness of the adhesive layer is 10 μm or more and 100 μm or less.

8. 2. The paint substitute film according to claim 1, further comprising a protective film on the side of the decorative layer opposite to the thermoplastic base film layer.

9. A method for dismantling an article in which the adhesive side of the paint substitute film according to any one of claims 1 to 8 is attached to at least a part of the surface of the object to be decorated, The paint substitute film is subjected to at least one external stimulus of heating or irradiation with active energy rays to cause foaming inside the adhesive layer, thereby separating the paint substitute film from the object to be decorated. A method comprising:

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