Decorative film, decorative laminated structure, and peeling method

Abstract

To provide a decorative film that maintains strong adhesion to the substrate at room temperature while suppressing adhesive residue when peeled off the substrate. [Solution] The easily peelable decorative film 100 comprises a base material 30 and an adhesive layer 10, wherein the adhesive layer 10 contains a moisture-cured product of a silyl group-containing resin and a terpene phenol-based tackifying resin, and the silyl group-containing resin has a polyoxyalkylene structure in its main chain, and has both urethane bonds and urea bonds in a part of the main chain or in a side chain, or has either a urethane bond or a urea bond, and has hydrolyzable silyl groups of formula (1) at both ends of the main chain (X1 and X2 are hydroxyl or alkoxy groups, and R is an alkyl group). TIFF2026165786000014.tif39170

Description

[Technical Field]

[0001] The present invention relates to a decorative film, a decorative laminated structure, and a peeling method. [Background technology]

[0002] A technique has been proposed for attaching decorative films to an object in order to impart design to that object. For example, a decorative film comprising an adhesive layer formed from an acrylic adhesive composition is known, and the object is decorated by attaching the adhesive side of the decorative film to the object.

[0003] Patent Document 1 discloses a decorative film in which a polyvinyl chloride film layer, an adhesive layer, and a separator are laminated in that order, and the adhesive layer is made of an adhesive composition containing an acrylic adhesive with a weight-average molecular weight of 500,000 to 2,000,000, a hindered amine light stabilizer, and an ultraviolet absorber.

[0004] Patent Document 2 discloses a decorative film comprising a base film and an adhesive layer laminated on the base film. In the decorative film described in Patent Document 2, the adhesive layer is formed from an adhesive composition comprising a (meth)acrylic copolymer (A), a (meth)acrylic copolymer (B), and a crosslinking agent. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2021-030584 [Patent Document 2] Japanese Patent Publication No. 2024-146838 [Overview of the project] [Problems that the invention aims to solve]

[0006] In recent years, the technology of applying decorative films to substrates to enhance their aesthetic appeal has attracted attention as a technology that can reduce carbon dioxide emissions compared to the technology of applying paint. Furthermore, with the aim of building a circular economy, there is a growing demand for the reuse of used products, and therefore, there is a growing demand for the reuse of decorative laminated structures in which the substrate is decorated with decorative films.

[0007] While decorative laminated structures require strong adhesion of the decorative film to the substrate during use, they also require easy separation and removal of the decorative film from the substrate when reusing used decorative laminated structures. Until now, no decorative film capable of satisfying these requirements was known.

[0008] For example, in a decorative laminated structure attached to a substrate using a decorative film having an adhesive layer formed with an acrylic adhesive composition, it has been found that by reducing the adhesive strength of the decorative film at high temperatures, it is possible to peel it off from the substrate by heating, thereby allowing the decorative film to be separated and removed from the decorative laminated structure. However, when separating and removing the adhesive layer from a substrate to which such a decorative film having an adhesive layer made of an acrylic adhesive composition is attached, cohesive failure of the adhesive layer may occur when the decorative film is peeled off the substrate, resulting in adhesive residue on the substrate. For this reason, it is difficult to easily peel the decorative film from a substrate in a decorative laminated structure attached with an adhesive layer made of an acrylic adhesive composition.

[0009] On the other hand, it is possible to suppress the occurrence of adhesive residue on the adherend by improving the crosslinking density of the adhesive layer made of an acrylic adhesive composition. However, since adhesive layers with improved crosslinking density tend to have reduced adhesive strength at room temperature, there is a concern that the decorative film may easily peel off the adherend during use of the decorative laminated structure.

[0010] The object of the present invention is to provide a decorative film that maintains strong adhesion to an adherend at room temperature while suppressing adhesive residue when peeled from the adherend, a decorative laminated structure using the decorative film, and a method for peeling the decorative film from the decorative laminated structure. [Means for solving the problem]

[0011] [1] A decorative film having easy peelability, It comprises a base material and an adhesive layer, The adhesive layer comprises a moisture-cured product of a silyl group-containing resin and a terpene phenol-based tackifying resin. The silyl group-containing resin is The main chain has a polyoxyalkylene structure, In part of the main chain or side chains, It has both urethane and urea bonds, or Having either the urethane bond or the urea bond, The main chain has hydrolyzable silyl groups represented by the following formula (1) at both ends. Decorative film.

[0012] [ka]

[0013] (In formula (1) above, X1 and X2 are each independently a hydroxyl group or an alkoxy group, R is an alkyl group having 1 to 20 carbon atoms, and * is a bond position.)

[0014] [2] In the decorative film described in [1], At 80°C, when the tensile load is 1 N / 10 mm, the elongation of the decorative film in the MD direction and the CD direction is 5.0% or less, respectively. Decorative film.

[0015] [3] In the decorative film described in [1] or [2], The content of the terpene phenol-based tackifier resin is 20 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the silyl group-containing resin, A decorative film.

[0016] [4] The decorative film according to any one of [1] to [3], The pressure-sensitive adhesive layer further contains an acrylic tackifier resin, The content of the acrylic tackifier resin is 1 part by mass or more and 100 parts by mass or less relative to 100 parts by mass of the silyl group-containing resin, A decorative film.

[0017] [5] The decorative film according to [4], The weight average molecular weight Mw of the acrylic tackifier resin is 300 or more and 10000 or less, A decorative film.

[0018] [6] The decorative film according to any one of [1] to [5], The base material contains at least one resin selected from the group consisting of vinyl chloride resin, urethane resin, and olefin resin, A decorative film.

[0019] [7] The decorative film according to any one of [1] to [6], A release liner is provided on the surface of the pressure-sensitive adhesive layer opposite to the surface where the base material is provided, A decorative film.

[0020] [8] The decorative film according to any one of [1] to [7], A laminate layer is provided on the surface of the base material opposite to the surface where the pressure-sensitive adhesive layer is provided, A decorative film.

[0021] [9] The decorative film according to [8], The laminate layer contains a fluororesin, A decorative film.

[0022]

[10] In the decorative film described in any one of the items [1] to [9], The adhesive strength of the decorative film to the substrate at 23°C when peeled off at 180°C, measured in accordance with the measurement method specified in JIS Z0237:2022, is defined as the room-temperature adhesive strength PsL. When the high-temperature adhesive strength PsH of the decorative film on the substrate at a temperature of 60°C or higher, measured in accordance with the measurement method specified in JIS Z0237:2022, The ratio of the high-temperature adhesive strength PsH to the room-temperature adhesive strength PsL satisfies the following formula (Equation 1): Decorative film. 0.2 ≥ (PsH / PsL) > 0 ···(Math 1)

[0023]

[11] Decorative laminated structure, A substrate comprising at least one material selected from the group consisting of metal, glass, and resin, The decorative film described in any one of [1] to

[10] is attached to the adherend, comprising: Decorative laminated structure.

[0024]

[12] A method for peeling a decorative film from a decorative laminated structure, A step of preparing a decorative laminated structure comprising: a substrate comprising at least one material selected from the group consisting of metal, glass, and resin; and a decorative film according to any one of [1] to

[10] attached to the substrate; A step of heating the decorative laminated structure, The process includes a step of separating and removing the decorative film from the adherend after heating the decorative laminated structure, while the temperature is decreasing to the ambient temperature of the peeling work environment. Method of removal. [Effects of the Invention]

[0025] According to one aspect of the present invention, a decorative film is provided that maintains strong adhesion to an adherend at room temperature while suppressing adhesive residue when peeled from the adherend, a decorative laminated structure using the decorative film, and a method for peeling the decorative film from the decorative laminated structure. [Brief explanation of the drawing]

[0026] [Figure 1] This is a schematic cross-sectional view showing an example of a decorative film according to the first embodiment of the first model. [Figure 2] This is a schematic cross-sectional view showing an example of a decorative film according to a second aspect of the first embodiment. [Figure 3] This is a schematic cross-sectional view showing an example of a decorative film according to a third aspect of the first embodiment. [Figure 4] This is a schematic cross-sectional view showing another example of a decorative film according to a third embodiment of the first embodiment. [Figure 5] This is a schematic cross-sectional view showing another example of a decorative film according to a third embodiment of the first embodiment. [Figure 6] This is a schematic cross-sectional view showing an example of a decorative laminated structure according to the second embodiment. [Figure 7] This is a schematic diagram illustrating an example of a peeling method according to the third embodiment. [Modes for carrying out the invention]

[0027] <First Embodiment> [Decorative film] The easily peelable decorative film according to this embodiment comprises a substrate and an adhesive layer. The adhesive layer comprises a moisture-cured product of a silyl group-containing resin and a terpene phenol-based tackifying resin, wherein the silyl group-containing resin has a polyoxyalkylene structure in its main chain and has both urethane bonds and urea bonds in a part of the main chain or in its side chains, or has either one of the urethane bonds or the urea bonds, and has hydrolyzable silyl groups represented by the following formula (1) at both ends of the main chain.

[0028] [ka]

[0029] (In formula (1) above, X1 and X2 are each independently a hydroxyl group or an alkoxy group, R is an alkyl group having 1 to 20 carbon atoms, and * is a bond position.)

[0030] The adhesive layer of the decorative film according to this embodiment contains a moisture-cured product of a silyl group-containing resin. The moisture-cured product of the silyl group-containing resin is pre-cured by moisture. The decorative film according to this embodiment is used by attaching the adhesive layer to an adherend. Pre-cured by moisture means that the silyl group-containing resin contained in the adhesive layer formed by the adhesive composition containing the silyl group-containing resin is already moisture-cured before use of the decorative film according to this embodiment. Therefore, the adhesive layer in the decorative film according to this embodiment is different from an adhesive layer formed by coating an adherend with an adhesive composition before moisture curing. For example, the storage modulus of the adhesive layer before and after moisture curing is different. The storage modulus of the adhesive layer containing the pre-cured silyl group-containing resin is, for example, 70,000 Pa or more at room temperature.

[0031] The decorative film according to this embodiment, having the above configuration, maintains high adhesion to the adherend at room temperature while suppressing adhesive residue when peeled off from the adherend. Specifically, the decorative film according to this embodiment achieves high adhesion to the adherend at room temperature (for example, 23°C). Here, room temperature refers to the temperature when the decorative laminate structure is not heated by a heating means, and is, for example, in a temperature range of approximately 15°C to 30°C. Furthermore, if the decorative film according to this embodiment is separated and removed from the adherend by heating at a high temperature (for example, 60°C or higher) after being attached to the adherend, adhesive residue on the adherend is suppressed.

[0032] Therefore, when an object is decorated using the decorative film according to this embodiment, a high adhesive strength is maintained between the object and the decorative film at room temperature. When the decorative film is peeled off the object after it has been heated and before it cools to the ambient temperature of the peeling work environment, the generation of adhesive residue on the object is suppressed. As a result, by using the decorative film according to this embodiment, it becomes easier to peel the decorative film from a decorated laminated structure that includes an object decorated with the decorative film according to this embodiment, and the object can be recovered without leaving any adhesive residue. Consequently, it becomes easier to reuse objects decorated using the decorative film according to this embodiment.

[0033] In one embodiment, the decorative film according to this embodiment may include a release liner provided on the side opposite to the side on which the substrate of the adhesive layer is provided.

[0034] In one embodiment, the decorative film according to this embodiment may include a laminate layer provided on the side of the substrate opposite to the side on which the adhesive layer is provided.

[0035] The decorative film according to this embodiment will be described below with reference to the drawings. In the drawings, some parts are enlarged or reduced in size for the sake of clarity.

[0036] "First aspect" A first embodiment of the decorative film according to this embodiment comprises a substrate and an adhesive layer provided on one side of the substrate.

[0037] Figure 1 shows a schematic cross-sectional view representing an example of a decorative film. As shown in Figure 1, the decorative film 100 comprises a base material 30 and an adhesive layer 10. The base material 30 has a first main surface 30A and a second main surface 30B opposite to the first main surface 30A. The first main surface 30A of the base material 30 is the exposed surface. In the decorative film 100, the base material 30 functions as a decorative layer capable of imparting design features such as color and patterns, and the first main surface 30A is the decorative surface. The second main surface 30B of the base material 30 is the surface on which the adhesive layer 10 is placed. The adhesive layer 10 contains a moisture-cured silyl group-containing resin as component (A) and a terpene phenol-based tackifying resin as component (B). The moisture-cured silyl group-containing resin is a silyl group-containing resin that has been pre-cured in moisture. The silyl group-containing resin can harden by reacting with moisture in the atmosphere, and can, for example, harden in a room temperature or a temperature higher than room temperature with moisture in the atmosphere. The adhesive layer 10 comprises a first main surface 10A and a second main surface 10B on the opposite side of the first main surface 10A. In the decorative film 100, the second main surface 30B of the substrate 30 and the first main surface 10A of the adhesive layer 10 face each other, and the adhesive layer 10 is provided in direct contact with the substrate 30. The second main surface 10B of the adhesive layer 10 is the exposed surface and is the adhesive surface. As shown in Figure 1, the decorative film 100 has the substrate 30 and the adhesive layer 10 in contact, but is not limited to this, and any additional layer may be provided between the substrate 30 and the adhesive layer 10 as needed. The thickness of the base material 30 corresponds to the distance between the first main surface 30A and the second main surface 30B of the base material 30, and the thickness of the adhesive layer 10 corresponds to the distance between the first main surface 10A and the second main surface 10B of the adhesive layer 10. The same applies to the thicknesses of the other layers described later.

[0038] Here, the main surface refers to the largest surface of the decorative film 100, the surface facing the thickness direction. For convenience, the terms first main surface and second main surface are used to clarify the positional relationship between one surface and the other of the decorative film 100. However, in some cases, the first and second main surfaces can be used interchangeably, and they can be used without distinction from each other. The same applies when referring to the main surface in the following explanation.

[0039] (base material) The base material 30 can support the adhesive layer 10. The base material 30 is, for example, a resin-containing base material, and is preferably a resin film. The resin contained in the base material 30 is not particularly limited and includes, for example, vinyl chloride resin, urethane resin, olefin resin, polyester resin, acrylic resin, and ethylene-vinyl acetate copolymer. Among these, from the viewpoint of ease of application, such as conformability to the adherend, it is preferable that the base material 30 contains at least one resin selected from the group consisting of vinyl chloride resin, urethane resin, and olefin resin.

[0040] Examples of vinyl chloride resins include various vinyl chloride resins such as vinyl chloride homopolymers and vinyl chloride-vinyl acetate copolymers.

[0041] Examples of urethane resins include polyester-based, polycaprolactone-based, polycarbonate-based, and polyether-based urethane resins.

[0042] Examples of olefin resins include homopolymers of α-olefins such as ethylene, propylene, methylpentene, and butene, as well as ethylene-α-olefin copolymers such as ethylene-propylene copolymers and ethylene-butene copolymers, and propylene-α-olefin copolymers such as propylene-ethylene copolymers and propylene-butene copolymers.

[0043] If the base material 30 is colored, the base material may include, for example, a resin and a coloring pigment. The coloring pigment can be one or more colored pigments, such as black, white, red, orange, yellow, green, blue, purple, gold, silver, and pearlescent, depending on the desired color and tone. The base material 30 may also be embossed, for example, to create a desired pattern.

[0044] The substrate 30 may, for example, have a printed layer on the first main surface 30A side, in which an ink containing a binder resin and the aforementioned coloring pigment is printed using various printing methods. The substrate 30 with the printed layer functions as a decorative layer.

[0045] The thickness of the substrate 30 is not particularly limited and may be, for example, 5 μm or more and 500 μm or less. The thickness of the substrate 30 may be, for example, 10 μm or more, or 15 μm or more. The thickness of the substrate 30 may be, for example, 400 μm or less, 300 μm or less, or 200 μm or less.

[0046] (Adhesive layer) The adhesive layer 10 comprises a moisture-cured silyl group-containing resin and a terpene phenol-based tackifying resin. The adhesive layer 10 may optionally further contain an acrylic-based tackifying resin.

[0047] [Silicone group-containing resin] The silyl group-containing resin has the following elements (a), (b), and (c). Element (a): Has a polyoxyalkylene structure in the main chain. Element (b): The main chain or side chain has both urethane bonds and urea bonds, or has either one of the urethane bonds or urea bonds. Element (c): The main chain has hydrolyzable silyl groups represented by formula (1) at both ends.

[0048] The above element (b) corresponds to any of the following elements (b-1), (b-2), (b-3), or (b-4). Element (b-1): The main chain has both urethane and urea bonds in a portion of it. Element (b-2): A portion of the main chain has either the urethane bond or the urea bond. Element (b-3): The side chain has both the urethane bond and the urea bond. Element (b-4): The side chain has either the urethane bond or the urea bond.

[0049] The silyl group-containing resin having elements (a), (b), and (c) is the silyl group-containing resin before moisture curing. When the silyl group-containing resin is moisture-cured, the hydrolyzable silyl groups represented by formula (1) undergo hydrolysis and dehydration condensation. As a result, the moisture-cured product of the silyl group-containing resin contains almost no hydrolyzable silyl groups represented by formula (1). In this specification, unless otherwise specified, the term "silyl group-containing resin" refers to the silyl group-containing resin before moisture curing, while the term "moisture-cured silyl group-containing resin" or similar terminology refers to the silyl group-containing resin after moisture curing.

[0050] In formula (1) above, R is an alkyl group having 1 to 20 carbon atoms. From the viewpoint of reactivity in hydrolysis dehydration condensation, R in formula (1) above is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, even more preferably an alkyl group having 1 to 3 carbon atoms, and still more preferably an alkyl group having 1 to 2 carbon atoms.

[0051] In formula (1) above, X1 and X2 are each independently a hydroxyl group or an alkoxy group. When at least one of X1 and X2 is an alkoxy group, from the viewpoint of reactivity in hydrolysis dehydration condensation, it is preferably an alkoxy group having 1 to 12 carbon atoms, more preferably an alkoxy group having 1 to 6 carbon atoms, even more preferably an alkoxy group having 1 to 3 carbon atoms, and still more preferably an alkoxy group having 1 to 2 carbon atoms. It is preferable that both X1 and X2 are alkoxy groups.

[0052] A silyl group-containing resin can be synthesized by mixing a urethane prepolymer having isocyanate groups obtained by reacting a polyol with a polyvalent isocyanate compound, and a silylation agent having hydrolyzable silyl groups represented by formula (1) and active hydrogen groups that can react with isocyanate groups, and reacting the urethane prepolymer and the silylation agent under predetermined conditions (e.g., 80°C for 1 hour) under a nitrogen atmosphere. The absorption peak of the isocyanate group (2265 cm⁻¹) measured by infrared spectroscopy (IR) indicates the reaction. -1 It is preferable to continue until the disappearance of the silyl group is confirmed. The silyl group-containing resin can be cured by a crosslinking reaction via hydrolysis of the hydrolyzable silyl group represented by formula (1) above to form a three-dimensional network structure.

[0053] The silyl group-containing resin is not limited to synthesis by reaction of the urethane prepolymer with the silylation agent. For example, the silyl group-containing resin can also be synthesized by reacting a silylation agent having an isocyanate group with a polymer having an active hydrogen group.

[0054] In silyl group-containing resins, the active hydrogen in both urethane bonds and urea bonds, or in either the urethane bond or the urea bond, which is introduced into part of the main chain or side chains, may be substituted with an organic group. Therefore, allophanate bonds are included in the category of urethane bonds, and biuret bonds are included in the category of urea bonds.

[0055] In formula (1) above, * may be a bonding position with an alkylene group having 1 to 20 carbon atoms. In formula (1) above, * is preferably a bonding position with an alkylene group having 2 to 16 carbon atoms, and more preferably a bonding position with an alkylene group having 3 to 12 carbon atoms. The alkylene group having 1 to 20 carbon atoms is preferably a linear alkylene group.

[0056] From the viewpoint of strengthening adhesion to the adherend, the specific structure of the terminal portion in the silyl group-containing resin is preferably a structure selected from the group consisting of formulas (11), (12), (13), (14), (15), (16), and (17). The structures represented by formulas (11) to (17) below contain a hydrolyzable silyl group represented by formula (1).

[0057] [ka]

[0058] [ka]

[0059] [ka]

[0060] [ka]

[0061] [ka]

[0062] [ka]

[0063] [ka]

[0064] (In equations (11), (12), (13), and (14) above, X1 and X2 are independently either a hydroxyl group or an alkoxy group. R is an alkyl group having 1 to 20 carbon atoms. R A and R B Each of these is an alkyl group having 1 to 20 carbon atoms, * indicates the bonding position. In equations (15) and (16) above, X1 and X2 are independently either a hydroxyl group or an alkoxy group. R is an alkyl group having 1 to 20 carbon atoms. * indicates the bonding position. In the above formula (17), X1 and X2 are independently either a hydroxyl group or an alkoxy group. R is an alkyl group having 1 to 20 carbon atoms. L is an alkylene group having 1 to 20 carbon atoms. R C This is an organic group having 1 or more carbon atoms and 20 or fewer carbon atoms. * indicates a bond position.

[0065] In the above equation (17), R CThe organic group represented is preferably an alkyl group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, a heterocyclic group having 2 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms.

[0066] From the viewpoint of exhibiting high tackiness and high elastic modulus to the adherend at room temperature, it is preferable that the silyl group-containing resin does not have hydrolyzable silyl groups represented by formula (1) in its side chains, but has hydrolyzable silyl groups represented by formula (1) only at both ends of the main chain. If the silyl group-containing resin does not have hydrolyzable silyl groups represented by formula (1) in its side chains, but has hydrolyzable silyl groups represented by formula (1) only at both ends of the main chain, the crosslinking density between the silyl group-containing resins can be adjusted to an appropriate range, making it easier to adjust the compatibility between the silyl group-containing resin and the tackifying resin to a more suitable range.

[0067] The silyl group-containing resin has a polyoxyalkylene structure in its main chain. If the silyl group-containing resin has a polyoxyalkylene structure in its main chain, the adhesive layer 10 can have appropriate flexibility, and the adhesive strength to the adherend can be further improved. The polyoxyalkylene structure is not particularly limited and includes, for example, polyoxypropylene, polyoxyethylene, and combinations thereof. The polyoxyalkylene structure may be present not only in the main chain of the silyl group-containing resin, but also in both the main chain and side chains.

[0068] The weight-average molecular weight Mw of the silyl group-containing resin is preferably 10,000 or more, and preferably 200,000 or less, from the viewpoint of ease of forming the adhesive layer 10 and having high adhesive strength to the adherend at room temperature. The weight-average molecular weight Mw of the silyl group-containing resin may be 12,000 (12,000) or more, or 15,000 (15,000) or more. The weight-average molecular weight Mw of the silyl group-containing resin may be 150,000 or less, or 100,000 or less. The weight-average molecular weight Mw of a silyl group-containing resin can be measured under predetermined conditions using a known molecular weight measuring device such as gel permeation chromatography (GPC).

[0069] The decorative film according to this embodiment is thought to suppress adhesive residue on the adherend when peeling the decorative film according to this embodiment from the adherend, due to the high cohesive force of the silyl group-containing resin contained in the adhesive layer 10. From the viewpoint of maintaining adhesive strength to the adherend at room temperature while suppressing adhesive residue when peeling from the adherend, the content of the silyl group-containing resin in the adhesive layer 10 is preferably 20% by mass or more and 90% by mass or less of the total (100% by mass) of the adhesive layer 10. The content of the silyl group-containing resin is more preferably 25% by mass or more, and even more preferably 30% by mass or more, based on the total amount (100% by mass) of the adhesive layer 10. The content of the silyl group-containing resin is more preferably 80% by mass or less, and even more preferably 75% by mass or less, relative to the total (100% by mass) of the adhesive layer 10.

[0070] [Terpene phenol-based tackifying resin] The adhesive layer 10 contains a terpene phenol-based tackifying resin. The terpene phenol-based tackifying resin has excellent compatibility with silyl group-containing resins. The inclusion of the terpene phenol-based tackifying resin in the adhesive layer 10 improves the adhesive strength to the adherend at room temperature. The terpene phenol-based tackifying resin is a copolymer of a terpene resin and phenol, and has a double bond derived from terpene and an aromatic ring double bond derived from phenol. The terpene phenol-based tackifying resin may be a fully hydrogenated terpene phenol-based tackifying resin or a partially hydrogenated terpene phenol-based tackifying resin.

[0071] Fully hydrogenated terpene phenol tackifying resins are tackifying resins obtained by substantially completely hydrogenating terpene phenol tackifying resins. Fully hydrogenated terpene phenol tackifying resins refer to tackifying resins in which both the terpene and phenol moieties are hydrogenated completely or nearly completely. Partially hydrogenated terpene phenol tackifying resins are tackifying resins obtained by partially hydrogenating a terpene phenol tackifying resin. Partially hydrogenated terpene phenol tackifying resins refer to tackifying resins in which both the terpene and phenol moieties are not completely or nearly completely hydrogenated, but are only partially hydrogenated. The method of hydrogenating the terpene phenol tackifying resin is not particularly limited. The hydrogenation rate of the terpene phenol-based tackifying resin may be, for example, 50 mol% or more, 65 mol% or more, 80 mol% or more, or 100 mol% or less, relative to 100 mol% of the unsaturated bonds of the terpene phenol-based resin, from the viewpoint of improving the adhesive strength to the adherend at room temperature. The terpene phenol-based resin may be used alone or in combination of two or more types.

[0072] Whether a resin is a fully hydrogenated terpene phenol-based tackifying resin or a partially hydrogenated terpene phenol-based tackifying resin can be determined using the FT-IR spectrum obtained by a Fourier transform infrared spectrophotometer (FT-IR). Specifically, it originates from the carbon-hydrogen bond stretching vibration of the methyl group, which is approximately 2960 cm². -1 When the peak height is set to 100, the value of 1625 cm² originates from the aromatic carbon-carbon double bond stretching vibration of the phenol moiety. -1 Above, 1575cm -1 This can be determined by the height of the following peaks.

[0073] The softening point of the terpene phenol-based tackifying resin is not particularly limited and may be, for example, 110°C or higher and 180°C or lower, from the viewpoint of improving the adhesive strength to the adherend at room temperature. The softening point of the terpene phenol-based tackifying resin can be measured by, for example, filling a support ring with the sample, placing a sphere of a certain weight in the center of the support ring in a bath of water or glycerin, raising the bath temperature at a specified rate, and then measuring the temperature at which the sample sags due to the weight of the sphere.

[0074] From the viewpoint of improving the adhesive strength to the adherend at room temperature, the content of the terpene phenol-based tackifying resin is preferably 20 parts by mass or more and 100 parts by mass or less per 100 parts by mass of the silyl group-containing resin. The content of the terpene phenol-based tackifying resin is more preferably 30 parts by mass or more, even more preferably 35 parts by mass or more, and even more preferably 40 parts by mass or more, per 100 parts by mass of the silyl group-containing resin. The content of the terpene phenol-based tackifying resin is more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of the silyl group-containing resin.

[0075] [Acrylic tackifying resin] In addition to containing a moisture-cured silyl group-containing resin as component (A) and a terpene phenol-based tackifying resin as component (B), the adhesive layer 10 may further contain an acrylic tackifying resin as component (C). The inclusion of an acrylic tackifying resin in the adhesive layer 10 makes it easier to improve the adhesion strength to the adherend at room temperature.

[0076] Acrylic tackifying resins are composed of, for example, (meth)acrylic acid ester polymers. Examples of (meth)acrylic acid ester polymers include polymers using alkyl (meth)acrylic acid esters as monomers, where the alkyl group has 1 to 20 carbon atoms. Alkyl (meth)acrylic acid esters may have an alicyclic structure within the molecule. The (meth)acrylic acid ester polymer may be a homopolymer of (meth)acrylic acid esters or a copolymer of (meth)acrylic acid esters. The copolymer of (meth)acrylic acid esters may be a copolymer of (meth)acrylic acid ester monomers and other monomers. The acrylic tackifying resin may contain functional groups such as carboxyl groups to facilitate the peeling of the decorative film from the decorative laminated structure, but it may not contain functional groups such as carboxyl groups.

[0077] In this specification, "(meth)acrylic" means both acrylic and methacrylic. The same applies to other similar terms.

[0078] Examples of alkyl acrylate monomers constituting the (meth)acrylate polymer include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate and dodecyl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, and stearyl (meth)acrylate. Alkyl (meth)acrylates may be used individually or in combination of two or more.

[0079] Other monomers that constitute the (meth)acrylic acid ester polymer when the (meth)acrylic acid ester polymer is a copolymer include, for example, carboxyl group-containing vinyl monomers, hydroxyl group-containing vinyl monomers, vinyl ether monomers, nitrogen-containing vinyl monomers, aromatic vinyl monomers, and vinyl ester monomers. These other monomers may be used individually from the same group or in combination of two or more. Alternatively, these other monomers may be used individually from different groups or in combination of two or more.

[0080] Examples of carboxyl group-containing vinyl monomers include (meth)acrylate maleic acid, itaconic acid, monomethyl maleic acid, monomethyl citraconic acid, 2-carboxyethyl acrylate, 2-carboxyethyl methacrylate, mono(2-acryloyloxyethyl) succinate, and mono(2-methacryloyloxyethyl) succinate. Examples of hydroxyl group-containing vinyl monomers include hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Examples of vinyl ether monomers include hydroxybutyl vinyl ether. Examples of nitrogen-containing vinyl monomers include monomethylaminoethyl (meth)acrylate, acrylamide, and acryloylmorpholine. Examples of aromatic vinyl monomers include olefins such as ethylene and propylene, as well as styrene. Examples of vinyl ester monomers include vinyl acetate.

[0081] (Meth)acrylic acid ester copolymers can be produced by known methods such as solution polymerization, emulsion polymerization, bulk polymerization, or suspension polymerization. (Meth)acrylic acid ester copolymers may also be (meth)acrylic acid ester oligomers, from the viewpoint of improving adhesion to the adherend at room temperature.

[0082] The weight-average molecular weight Mw of the acrylic tackifying resin is preferably 300 or more and 10,000 or less. The weight-average molecular weight Mw of the acrylic tackifying resin is more preferably 500 or more, even more preferably 800 or more, and even more preferably 1000 or more. The weight-average molecular weight Mw of the acrylic tackifying resin is more preferably 8000 or less, even more preferably 6000 or less, and even more preferably 4000 or less. The weight-average molecular weight Mw of acrylic tackifying resins can be measured under predetermined measurement conditions using known molecular weight measuring devices such as gel permeation chromatography (GPC).

[0083] The softening point of the acrylic tackifying resin is not particularly limited and may be, for example, 120°C or higher and 190°C or lower, from the viewpoint of improving the adhesive strength to the adherend at room temperature. The softening point of the acrylic tackifying resin can be determined, for example, by the same measurement method as that used for the softening point of the terpene phenol-based tackifying resin described above.

[0084] From the viewpoint of improving the adhesive strength to the adherend at room temperature, the content of the acrylic tackifying resin is preferably 1 part by mass or more and 100 parts by mass or less per 100 parts by mass of the silyl group-containing resin. The content of the acrylic tackifying resin is more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, per 100 parts by mass of the silyl group-containing resin. The content of the acrylic tackifying resin is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of the silyl group-containing resin.

[0085] [Fluorine catalyst] The adhesive layer 10 contains, in addition to a moisture-cured silyl group-containing resin as component (A) and a terpene phenol-based tackifying resin as component (B), it may also contain a fluorine catalyst as component (D). The fluorine catalyst may be used as a fluorine catalyst solution dissolved in a silane coupling agent as component (E) described later, or the fluorine catalyst may be used alone.

[0086] If the adhesive layer 10 contains a fluorine catalyst, it may not contain an acrylic tackifying resin as component (C), but may instead contain a moisture-cured silyl group-containing resin as component (A), a terpene phenol-based tackifying resin as component (B), and a fluorine catalyst solution (a fluorine catalyst as component (D) and a silane coupling agent as component (E)). If the adhesive layer 10 contains a fluorine catalyst solution, it may also contain a moisture-cured silyl group-containing resin as component (A), a terpene phenol-based tackifying resin as component (B), an acrylic-based tackifying resin as component (C), and a fluorine catalyst solution (a fluorine catalyst as component (D) and a silane coupling agent as component (E)).

[0087] The fluorine catalyst may be at least one selected from the group consisting of boron trifluoride and boron trifluoride complexes. From the viewpoint of ease of handling, the fluorine catalyst is preferably a boron trifluoride complex. Examples of boron trifluoride complexes include boron trifluoride amine complexes, boron trifluoride alcohol complexes, boron trifluoride ether complexes, boron trifluoride thiol complexes, boron trifluoride sulfide complexes, boron trifluoride carboxylic acid complexes, and boron trifluoride aqueous complexes. From the viewpoint of excellent stability and catalytic activity, the boron trifluoride complex is preferably a boron trifluoride amine complex. The boron trifluoride complex may be used alone or in combination of two or more types. Using a boron trifluoride complex as a fluorine catalyst makes it easier to suppress the hydrolysis of urethane and urea bonds contained in silyl group-containing resins. This reduces adhesive residue when peeling from the substrate while improving adhesion at room temperature. Furthermore, it also improves high-temperature adhesion while reducing adhesive residue when peeling from the substrate.

[0088] The boron trifluoride amine complex is not particularly limited and includes, for example, boron trifluoride monoethylamine complex, boron trifluoride diethylamine complex, boron trifluoride isopropylamine complex, boron trifluoride chlorophenylamine complex, boron trifluoride-trialylamine complex, boron trifluoride benzylamine complex, and boron trifluoride aniline complex.

[0089] The fluorine catalyst content is preferably 0.001 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the silyl group-containing resin.

[0090] [Silane coupling agent] The silane coupling agent is not particularly limited. For example, the silane coupling agent may be an amino group-containing alkoxysilane. Examples of silane coupling agents include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane. The silane coupling agent may be used alone or in combination of two or more. The inclusion of the silane coupling agent in the adhesive layer 10 makes it easier for it to exert its effect as a crosslinking aid.

[0091] The content of the silane coupling agent is preferably 0.01 parts by mass or more and 1 part by mass or less per 100 parts by mass of the silyl group-containing resin.

[0092] The adhesive layer 10 may also contain various additives in addition to the above-mentioned components. Examples of various additives include antioxidants, dehydrating agents (vinylsilane compounds and calcium oxide, etc.), fillers, conductive materials, thermally conductive materials, plasticizers, thixotropes (anhydrous silica and amide wax, etc.), diluents (isoparaffin, etc.), flame retardants (aluminum hydroxide, halogen-based, phosphorus-based, and silicone-based), silicone alkoxy oligomers, pigments, titanate coupling agents, aluminum coupling agents, and drying oils.

[0093] The adhesive layer 10 may be formed, for example, by a hot-melt adhesive composition. In this specification, a hot-melt adhesive composition refers to an adhesive composition that melts upon heating, becomes spreadable and coatable, and exhibits tackiness and cohesive force upon cooling. The adhesive layer 10 may be formed, for example, by a solvent-type adhesive composition.

[0094] The thickness of the adhesive layer 10 is preferably 1 μm or more and 500 μm or less. The thickness of the adhesive layer 10 is more preferably 5 μm or more, even more preferably 10 μm or more, and even more preferably 20 μm or more. The thickness of the adhesive layer 10 is more preferably 300 μm or less, even more preferably 200 μm or less, and even more preferably 100 μm or less.

[0095] "Second form" A second embodiment of the decorative film according to this embodiment comprises a substrate, an adhesive layer provided on one side of the substrate, and a release liner provided on the side of the adhesive layer opposite to the substrate. The following describes an embodiment in which a release liner is provided on the second main surface 10B of the adhesive layer 10 shown in Figure 1.

[0096] The following explanation will primarily focus on the differences from the decorative film 100 described above, and redundant explanations will be omitted or simplified. Components similar to those of the decorative film 100 will be given the same reference numerals, and their explanations will be omitted or simplified.

[0097] Figure 2 shows a schematic cross-sectional view representing another example of a decorative film, specifically an example of a decorative film equipped with a release liner. As shown in Figure 2, the decorative film 110 corresponds to the laminated structure shown in Figure 1, in which the release liner 20 is provided on the second main surface 10B of the adhesive layer 10. The first main surface 20A of the release liner 20 is the release surface. The second main surface 10B of the adhesive layer 10 faces the first main surface 20A of the release liner 20, and the adhesive layer 10 and the release liner 20 are in direct contact. In the decorative film 110, the release liner 20, the adhesive layer 10, and the substrate 30 are laminated in this order in the thickness direction (lamination direction).

[0098] (Removable liner) The release liner 20 is provided in contact with the second main surface 10B of the adhesive layer 10, which is the side of the adhesive layer 10 opposite to the side of the adhesive layer 10 on which the base material 30 is provided. The release liner 20 is a component provided to protect the adhesive layer 10 until the decorative film 110 is used. When the decorative film 110 is used, the release liner 20 is peeled off from the adhesive layer 10, exposing the second main surface 10B of the adhesive layer 10. The decorative film 110 with the second main surface 10B of the adhesive layer 10 exposed is used as the decorative film 100. After the release liner 20 is peeled off, the second main surface 10B of the adhesive layer 10 is attached to an object (not shown). When the adhesive layer 10 contains the aforementioned acrylic tackifying resin, it exhibits easier peeling force from the release liner 20 compared to when the adhesive layer 10 does not contain the aforementioned acrylic tackifying resin. Therefore, when using the decorative film 110, it becomes easier to peel the release liner 20 from the adhesive layer 10.

[0099] The release liner 20 is not particularly limited and can be any member having release properties. The release liner 20 can be any release material comprising, for example, a release substrate that supports the release agent layer of the release liner and a release agent layer formed by coating the release agent on the release substrate. In this specification, for convenience, in order to distinguish it from the substrate 30, the substrate that supports the release agent layer of the release liner is referred to as the release substrate.

[0100] Examples of release substrates include paper substrates (high-quality paper, glassine paper, and clay-coated paper, etc.), laminated paper obtained by laminating a thermoplastic resin such as polyethylene onto a paper substrate, and plastic films such as polyester (polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, etc.) and polyolefins (polypropylene and polyethylene, etc.). In addition, the release substrate may be embossed for purposes such as improving the workability of the decorative film 100 after removing the release liner 20 from the decorative film 110 (for example, making it less likely for distortion, wrinkles, and air bubbles to occur in the decorative film 100, and making it easier to apply to the substrate (not shown)), improving air release (making it easier to release air trapped between the decorative film 100 and the substrate when applying the decorative film 100 to the substrate), and improving repositionability (making it easier to peel the decorative film 100 from the substrate when resolving distortion, wrinkles, and air bubbles that occur when applying the decorative film 100 to the substrate). When the release substrate is embossed, the embossed pattern applied to the release substrate is transferred to the adhesive layer 10 of the decorative film 100, making it easier to obtain the above advantages. Furthermore, if the release substrate is a paper substrate, and there is a concern that the texture of the paper will be transferred to the substrate 30 when the decorative film 110 is wound into a roll, thereby impairing the aesthetic appearance after application, that is, that the adherend after the decorative film 100 is applied will significantly reduce the desired aesthetic appearance, then it is preferable that the release substrate be a resin substrate.

[0101] Examples of release agents include silicone-based, fluorine-based, and long-chain alkyl-based release agents.

[0102] The thickness of the release liner 20 is not particularly limited and may be, for example, 10 μm or more and 400 μm or less. If the release liner 20 includes a release agent layer, the thickness of the release agent layer may be, for example, 0.01 μm or more and 5 μm or less.

[0103] "The third aspect" A third embodiment of the decorative film according to this embodiment comprises a substrate, the aforementioned adhesive layer provided on one side of the substrate, and a laminate layer provided on the side of the substrate opposite to the side on which the adhesive layer is provided. The embodiment in which the laminate layer is provided on the first main surface 30A of the substrate 30 will be described below.

[0104] The following explanation will primarily focus on the differences between this product and the decorative films 100 and 110 mentioned above, omitting or simplifying any redundant explanations. Components similar to those of decorative films 100 and 110 are denoted by the same reference numerals, and their explanations will be omitted or simplified.

[0105] Figures 3, 4, and 5 schematically show examples of decorative films according to a third embodiment of this model. As shown in Figure 3, the decorative film 120 comprises a base material 30, an adhesive layer 10, and a laminate layer 40. The laminate layer 40 is provided on a first main surface 30A of the base material 30, which is the surface opposite to the side on which the adhesive layer 10 is provided. In the decorative film 120, the first main surface 30A of the base material 30 and the second main surface 40B of the laminate layer 40 face each other, and the laminate layer 40 is provided in direct contact with the base material 30. The first main surface 40A of the laminate layer 40 is the outermost surface and is exposed. In the decorative film 120, the adhesive layer 10, the base material 30, and the laminate layer 40 are provided in this order in the thickness direction.

[0106] As shown in Figure 4, the decorative film 130 comprises a base material 30, an adhesive layer 10, and a laminate layer 40. The laminate layer 40 is composed of a laminated structure having a first laminate layer 41 located on the outermost layer and a second laminate layer 42 located on the inner layer side of the base material 30. In the decorative film 130, the first main surface 30A of the base material 30 and the second main surface of the second laminate layer 42 (i.e., the second main surface 40B of the laminate layer 40) face each other, and the second laminate layer 42 is provided in direct contact with the base material 30. The first main surface of the first laminate layer 41 (i.e., the first main surface 40A of the laminate layer 40) is the outermost surface and is exposed. In the decorative film 130, the adhesive layer 10, the base material 30, the second laminate layer 42, and the first laminate layer 41 are arranged in this order in the thickness direction.

[0107] As shown in Figure 5, the decorative film 140 comprises a base material 30, an adhesive layer 10, a laminate layer 40, and an adhesive layer 50 for the laminate layer, with the laminate layer 40 being provided on the base material 30 via the adhesive layer 50 for the laminate layer. In the decorative film 140, the second main surface 40B of the laminate layer 40 and the first main surface 50A of the adhesive layer 50 for the laminate layer face each other, and the laminate layer 40 is provided in direct contact with the adhesive layer 50 for the laminate layer. The first main surface 40A of the laminate layer 40 is exposed. In the decorative film 140, the adhesive layer 10, the base material 30, the adhesive layer 50 for the laminate layer, and the laminate layer 40 are provided in this order in the thickness direction. In the decorative film 140, the laminate layer 40 can also be configured as a two-layer laminated structure, for example, as in the decorative film 130.

[0108] Although not shown in Figures 3, 4, and 5, a release liner 20, as shown in Figure 2, may be directly in contact with the second main surface 10B of the adhesive layer 10 to protect the adhesive surface of the adhesive layer 10 until the decorative films 120, 130, and 140 are used, respectively. In this case, the release liner 20 is peeled off when the decorative films 120, 130, and 140 are used, respectively.

[0109] When peeling the decorative film 100 according to the first embodiment of this model from an adherend, the peeling workability may decrease depending on the elongation of the base material 30. If a laminate layer 40 is provided on the base material 30, as in the decorative films 120, 130, and 140 shown in Figures 3, 4, and 5, the elongation of the base material 30 is suppressed, making it easier to peel the decorative films 120, 130, and 140 from the adherend. In addition, the presence of a laminate layer 40, as in the decorative films 120, 130, and 140, improves the scratch resistance of the base material 30.

[0110] (Laminate layer) The laminate layer 40 preferably contains a resin, and the resin contained in the laminate layer 40 is not particularly limited. To improve the visibility of the substrate 30 which functions as a decorative layer, the laminate layer 40 preferably has light-transmitting properties. The laminate layer 40 may contain, for example, at least one resin selected from the group consisting of acrylic resin and fluororesin. From the viewpoint of improving workability when peeling from the adherend, the laminate layer 40 preferably contains a fluororesin. The laminate layer 40 may contain, for example, only a fluororesin, or it may contain a fluororesin and a resin other than a fluororesin. In addition, the weather resistance of the laminate layer 40 is improved by containing a fluororesin.

[0111] Examples of acrylic resins include homopolymers of (meth)acrylic acid or (meth)acrylic acid esters, copolymers of (meth)acrylic acid or (meth)acrylic acid esters, and copolymers of (meth)acrylic acid or (meth)acrylic acid esters with other monomers. In this specification, "(meth)acrylic" means both acrylic and methacrylic. The same applies to other similar terms.

[0112] Examples of fluororesins include polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, tetrafluoroethylene-perfluoroalkoxyethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and polychlorotrifluoroethylene.

[0113] As shown in Figure 4, when the laminate layer 40 has a laminated structure, the outer first laminate layer 41 preferably contains a fluororesin. The first laminate layer 41 may contain only a fluororesin, or it may contain a fluororesin and other resins. For example, the first laminate layer 41 may contain a fluororesin and an acrylic resin. The inner second laminate layer 42 also preferably contains a fluororesin. The second laminate layer 42 may contain only a fluororesin, or it may contain a fluororesin and other resins. For example, the second laminate layer 42 may contain a fluororesin and an acrylic resin. When the first laminate layer 41 and the second laminate layer 42 each contain a fluororesin and an acrylic resin, the fluororesin and the acrylic resin may be the same or different. When the first laminate layer 41 and the second laminate layer 42 each contain a fluororesin and an acrylic resin, the mass ratio of the fluororesin to the acrylic resin may be the same or different. For example, from the viewpoint of weather resistance, the first laminate layer 41 may contain more fluororesin than the second laminate layer 42, and from the viewpoint of peelability, the second laminate layer 42 may contain more fluororesin than the first laminate layer 41.

[0114] The adhesive layer 50 for the laminate layer is not particularly limited and is formed from an adhesive composition containing various types of adhesives. Examples of adhesives include acrylic, rubber, silicone, urethane, polyester, and polyvinyl ether adhesives. Among these, an acrylic adhesive is preferred from the viewpoint of easily exhibiting adhesive strength with the substrate 30.

[0115] Examples of acrylic adhesives include polymers containing constituent units derived from alkyl (meth)acrylates, and acrylic polymers containing constituent units derived from (meth)acrylates having a cyclic structure.

[0116] From the viewpoint of improving workability when peeling from the adherend, the thickness of the laminate layer 40 is preferably 5 μm or more and 300 μm or less. The thickness of the adhesive layer 10 is more preferably 10 μm or more, even more preferably 15 μm or more, and even more preferably 20 μm or more. The thickness of the laminate layer 40 is more preferably 250 μm or less, even more preferably 200 μm or less, and even more preferably 150 μm or less. Even when the laminate layer 40 has a laminated structure comprising a first laminate layer 41 and a second laminate layer 42, the thickness of the laminate layer 40 is preferably 5 μm or more and 300 μm or less.

[0117] The thickness of the adhesive layer 50 for the laminate layer is preferably 1 μm or more and 500 μm or less. The thickness of the adhesive layer 10 is more preferably 5 μm or more, even more preferably 10 μm or more, and even more preferably 20 μm or more. The thickness of the adhesive layer 10 is more preferably 300 μm or less, even more preferably 200 μm or less, and even more preferably 100 μm or less.

[0118] [Characteristics of decorative films] In this embodiment, the decorative films 100, 120, 130, and 140 preferably have an elongation (tensile elongation at high temperature) in the MD direction and CD direction when the tensile load is 1 N / 10 mm at 80°C, which is 5.0% or less. The MD direction is the direction corresponding to the flow direction during manufacturing of the substrate, and the CD direction is the direction perpendicular to the MD direction and corresponding to the width direction. It is also preferable that the elongation in the MD direction and CD direction when the tensile load is 1 N / 10 mm at 80°C be 20% or less, 10% or less, and 5% or less, respectively. The lower limit of the elongation in the MD direction and CD direction when the tensile load is 1 N / 10 mm at 80°C is not particularly limited, and for example, it may be 0% or more. The tensile elongation at high temperature in the CD direction may be smaller than the tensile elongation at high temperature in the MD direction. If the elongation in the MD and CD directions at a tensile load of 1 N / 10 mm at 80°C is, for example, 5.0% or less, then the elongation of the decorative films 100, 120, 130, and 140 at high temperatures is suppressed, which improves the workability when peeling them off the adherend by heating at high temperatures. The elongation in the MD and CD directions is measured after the release liner 20 is removed.

[0119] For decorative films 100, 120, 130, and 140, when the 180° peel adhesion force of the decorative film to the adherend at 23°C, measured at 80°C in accordance with the measurement method specified in JIS Z0237:2022, is defined as the room temperature adhesion force PsL, and the 180° peel adhesion force of the decorative film to the adherend at a temperature range of 60°C or higher (e.g., 100°C), measured in accordance with the measurement method specified in JIS Z0237:2022, is defined as the high-temperature adhesion force PsH, it is preferable that the ratio of the high-temperature adhesion force PsH to the room temperature adhesion force PsL satisfies the following formula (Equation 1). 0.2 ≥ (PsH / PsL) > 0 ···(Math 1)

[0120] The ratio of the high-temperature adhesive strength PsH to the room-temperature adhesive strength PsL is more preferably 0.19 or less, even more preferably 0.18 or less, and even more preferably 0.17 or less. If the ratio of the high-temperature adhesive strength PsH to the room-temperature adhesive strength PsL satisfies formula (Equation 1), the film will peel off easily when heated to a high temperature. In this embodiment, the decorative film satisfies the range of formula (Equation 1) regardless of whether the high-temperature adhesive strength PsH is measured at any of the following temperatures: 60°C, 80°C, 100°C, and 120°C. The room-temperature adhesive strength PsL and the high-temperature adhesive strength PsH are measured after the release liner 20 is removed.

[0121] (Method of manufacturing decorative film) The decorative film 110 can be obtained, for example, by a manufacturing method having the following steps. Decorative films 120, 130, and 140, when equipped with a release liner 20, can be manufactured in a similar manner.

[0122] (Step P1A): A step to prepare an adhesive composition comprising (A1) a silyl group-containing resin (the above-mentioned silyl group-containing resin before it becomes a moisture-cured product) and (B) a terpene phenol-based tackifying resin. (Step P2A): A step in which the adhesive composition prepared in Step P1A is applied to the surface of the release liner 20 to form a coating film of the adhesive composition, thereby forming an adhesive layer 10 on the surface of the release liner 20. (Process P3A): Process for preparing the base material 30. (Step P4A): A step of laminating the surface of the substrate 30 toward the adhesive layer 10.

[0123] Step P1A is a step of preparing at least the silyl group-containing resin and the terpene phenol-based tackifying resin described in the first embodiment above, and mixing the silyl group-containing resin and the terpene phenol-based tackifying resin so that their content in the adhesive layer 10 is predetermined, thereby preparing an adhesive composition. Specific examples of the silyl group-containing resin and the terpene phenol-based tackifying resin are as described above. The adhesive composition may optionally contain at least one component selected from the group consisting of, for example, acrylic tackifying resin, fluorine catalyst, silane coupling agent, and various additives. Specific examples of these components are as described above. As described above, the adhesive composition may be a hot-melt adhesive composition or a solvent-type adhesive composition.

[0124] Step P2A is a step in which an adhesive layer 10 is formed on one of the release liners 20 by applying the adhesive composition prepared in step P1A to the surface of the release liner 20. Specifically, the adhesive composition is applied to the first main surface 20A, which is the release treatment surface of the release liner 20, to form a coating film of the adhesive composition. This forms an adhesive layer 10 on the release liner 20. At this time, the first main surface 20A of the release liner 20 and the second main surface 10B of the adhesive layer 10 are in contact.

[0125] The method for applying the adhesive composition to the first main surface 20A of the release liner 20 is not particularly limited, and known application methods such as hot melt coater, bar coat method, knife coat method, air knife coat method, roll knife coat method, roll coat method, blade coat method, die coat method, gravure coat method, lip coat method, curtain coat method, dip coat method, and squeeze coat method can be used.

[0126] Step P3A is a step in which the base material 30 is prepared. The base material 30 can be formed by, for example, melt extrusion, calendering, and solution method. From the viewpoint of efficiently producing the base material, it is preferable to produce the base material 30 by melt extrusion.

[0127] As with the decorative films 120, 130, and 140 according to the third embodiment of the above-described embodiment, when the base material 30 is equipped with a laminate layer 40, it can be used as a base material 30 with a laminate layer 40. The base material 30 with a laminate layer 40 can be formed, for example, by the following methods: (I) A method of obtaining a base material 30 with a laminate layer 40 by forming a resin film by melt extrusion and bonding the resin film to the first main surface 30A of the base material 30 by heat bonding; (II) A laminated film formed by laminating a first laminate layer 41 and a second laminate layer 42 by melt co-extrusion, or a laminated film formed by forming a first resin film for the first laminate layer 41 and a second resin film for the second laminate layer 42, respectively, by melt extrusion, and laminating the first resin film and the second resin film. Examples of methods for obtaining a substrate 30 with a laminate layer 40 include (III) forming a resin film by melt extrusion, forming an adhesive layer 50 for the laminate layer on the resin film, and attaching the adhesive layer 50 of the resin film with the adhesive layer 50 to the first main surface 30A of the substrate 30. However, the method for obtaining a substrate 30 with a laminate layer 40 is not limited to these methods.

[0128] Step P4A is a step in which the surface of the substrate 30 is laminated onto the adhesive layer 10 formed in step P2A. Specifically, the second main surface 30B of the substrate 30 is laminated toward the first main surface 10A of the adhesive layer 10. Similarly, for the substrate 30 with the laminate layer 40, the second main surface 30B of the substrate 30 is laminated toward the first main surface 10A of the adhesive layer 10. After that, the silyl group-containing resin contained in the adhesive layer 10 is moisture-cured by leaving it (curing) for a predetermined time (for example, 7 days) in an environment where, for example, the temperature is in the range of 15°C to 50°C and the relative humidity is in the range of 45%RH to 85%RH.

[0129] The method for manufacturing the decorative film 110 is not limited to this, and instead of (steps P2A) and (steps P4A), the following steps may be adopted: (step P2B) applying the adhesive composition prepared in step P1A to the surface of the substrate 30 (for example, the second main surface 30B) to form a coating film of the adhesive composition and forming an adhesive layer 10 on the surface of the substrate 30; and (step P4B) laminating the release treatment surface of the release liner 20 toward the adhesive layer 10.

[0130] The decorative films 100, 110, 120, 130, and 140 can be applied to one or both flat and curved surfaces, respectively. The decorative films 100, 110, 120, 130, and 140 are used, for example, to decorate at least a portion of the interior and exterior materials of automobiles. In addition, the decorative films 100, 110, 120, 130, and 140 can also be used to decorate at least a portion of vehicles such as motorcycles and bicycles, home appliances such as refrigerators and televisions, electronic devices such as personal computers and tablet terminals, furniture, building materials, and miscellaneous goods, as well as parts used in these items.

[0131] (Effects of the first embodiment) According to this embodiment, the following effects can be achieved. (1A): Each decorative film 100, 110, 120, 130, and 140 is equipped with an adhesive layer 10 containing a silyl group-containing resin having hydrolyzable silyl groups of a specific structure and a terpene phenol-based tackifying resin, thereby maintaining high adhesion to the adherend at room temperature. (2A): Each of the decorative films 100, 110, 120, 130, and 140 is equipped with an adhesive layer 10 containing a silyl group-containing resin having hydrolyzable silyl groups of a specific structure and a terpene phenol-based tackifying resin. Therefore, when the decorative films 100, 110, 120, 130, and 140 are peeled off from a decorative laminate structure prepared by attaching them to an adherend, the adhesive residue on the adherend is suppressed due to the cohesive force of the silyl group-containing resin. (3A): Decorative films 100, 110, 120, 130, and 140 each exhibit improved adhesive strength at room temperature when the adhesive layer 10 further contains an acrylic tackifying resin. (4A): When the adhesive layer 10 of the decorative films 100, 110, 120, 130, and 140 further contains an acrylic tackifying resin, they exhibit a light peeling force, so that the release liner 20 and the adhesive layer 10 can be easily peeled off with a low peeling force. (5A): Each of the decorative films 120, 130, and 140 is equipped with a laminate layer 40, and when the decorative films 120, 130, and 140 are peeled off from the substrate at high temperatures, the elongation of the substrate 30 is suppressed, thereby improving the ease of peeling from the substrate.

[0132] <Second Embodiment> [Decorated laminated structure] The second embodiment is a decorative laminated structure. The decorative laminated structure according to the second embodiment comprises a substrate comprising at least one material selected from the group consisting of metal, glass, and resin, and a decorative film according to the first embodiment attached to the substrate.

[0133] The decorative laminated structure according to this embodiment will be described below with reference to the drawings. In the drawings, some parts are shown enlarged or reduced in size for the sake of clarity.

[0134] The following description will primarily focus on the differences from the decorative film of the first embodiment, and redundant explanations will be omitted or simplified. Components similar to those in the decorative film of the first embodiment will be denoted by the same reference numerals, and their explanations will be omitted or simplified. The following describes how the decorative film 120 shown in Figure 3 is attached to the substrate.

[0135] Figure 6 shows a schematic cross-sectional view of a decorative laminated structure 200 as an example of this embodiment. The decorative laminated structure 200 is an example of a decorative laminated structure according to this embodiment. The decorative laminated structure 200 uses the decorative film 120 described in the third aspect of the first embodiment. When the decorative film 120 has a release liner 20 described in the second aspect of the first embodiment attached to the adhesive layer 10, the decorative laminated structure 200 is manufactured by removing the release liner 20 from the decorative film 120 and attaching the adhesive layer 10 to the first main surface 60A of the adherend 60. The decorative laminated structure 200 comprises an adherend 60 and a decorative film 120, and the adherend 60, adhesive layer 10, base material 30, and laminate layer 40 are laminated in this order in the thickness direction.

[0136] (adherent) The adherend 60 comprises at least one material selected from the group consisting of metal, glass, and resin. The adherend 60 may also be a composite material containing each of these materials. If the adherend 60 is a composite material, the adherend 60 may be, for example, glass with metal vapor-deposited on it, resin with metal vapor-deposited on it, resin with metal foil laminated on it, or glass with metal vapor-deposited resin laminated on it. In addition, the adherend 60 may be glass with resin laminated on it, metal with resin laminated on it, metal with glass coating, or metal with paint.

[0137] The material of the metal substrate is not particularly limited and may be a single metal or an alloy such as steel plate, aluminum, or stainless steel. The material of the glass substrate is not particularly limited, and examples include soda-lime glass and borosilicate glass. The material of the resin adherend is not particularly limited and includes various resins such as polyolefins (polypropylene and polyethylene, etc.), polyesters (polyethylene terephthalate, polybutylene terephthalate, and polybutylene terephthalate, etc.), polycarbonate, polymethyl (meth)acrylate, urethane, ABS resin, and melamine. The resin may also be a foamed resin. In addition, fiber-reinforced plastics containing carbon fibers, etc., may also be used.

[0138] The shape of the adherend 60 is not particularly limited; for example, it may be plate-shaped or block-shaped. The surface of the adherend 60 may be flat, curved, or a combination of both. The adherend 60 may be formed of a material, shape, and dimensions appropriate to the purpose.

[0139] Examples of objects to be coated 60 include, for example, the interior and exterior of automobiles. Other examples of objects to be coated 60 include vehicles such as motorcycles and bicycles, home appliances such as refrigerators and televisions, electronic devices such as personal computers and tablet terminals, furniture, building materials, and miscellaneous goods, as well as parts used in these.

[0140] The decorative laminated structure 200 can be obtained by directly attaching the decorative film 120 to the first main surface 60A of the adherend 60, for example, by a molding method such as vacuum forming, pressure forming, or vacuum and pressure forming. Alternatively, it can be obtained by directly attaching the decorative film 120 to the first main surface 60A of the adherend 60 by hand. Furthermore, it can be obtained by directly attaching the decorative film 120 to the first main surface 60A of the adherend 60 using a tool such as a squeegee.

[0141] In the decorative laminated structure 200, the decorative film 120 is provided over the entire surface of the first main surface 60A of the adherend 60, but is not limited to this, and the decorative film 120 may be provided over a part of the first main surface 60A of the adherend 60. The decorative laminated structure may also be obtained by using a decorative film 100 (or a decorative film 110 from which the release liner has been removed), or decorative films 130, 140 instead of the decorative film 120.

[0142] (Effects of the second embodiment) According to this embodiment, the following effects can be achieved. (1B): The decorative laminated structure 200 includes a decorative film 120 having the adhesive layer 10 described in the first embodiment, and therefore maintains high adhesion to the adherend 60 at room temperature. For this reason, the decorative laminated structure 200 made by adhering the decorative film 120 to the adherend 60 is firmly bonded to the decorative film 120 and the adherend 60 at room temperature. The same applies when decorative film 100 (or decorative film 110 with the release liner removed), or decorative films 130, 140 are used instead of decorative film 120.

[0143] <Third Embodiment> [Removal Method] The third embodiment is a peeling method for peeling a decorative film from a decorative laminated structure. One embodiment of the peeling method according to this embodiment comprises the steps of: preparing a decorative laminated structure (step S1) comprising an adherend containing at least one material selected from the group consisting of metal, glass, and resin, and a decorative film according to the first embodiment attached to the adherend; heating the decorative laminated structure (step S2); and separating and removing the decorative film from the adherend after heating the decorative laminated structure until the temperature drops to the ambient temperature of the peeling work environment (step S3).

[0144] In the step of heating the decorative laminated structure of this embodiment, the method of heating the decorative laminated structure to be heated is not particularly limited. Examples of the steps for heating the decorative laminated structure in this embodiment include the following. In any of the following embodiments, the steps other than the step of heating the decorative laminated structure are the same.

[0145] In the peeling method according to this embodiment, the step of heating the decorative laminated structure (step S2) may, in one embodiment, be a method of heating the decorative laminated structure by leaving it in a high-temperature environment.

[0146] In this embodiment, a high-temperature environment is created, and the decorative laminated structure is heated by placing it in the created high-temperature environment. The high-temperature environment is created, for example, by heating a gas to a predetermined temperature using a heating means such as a heater, and then circulating the heated gas into the high-temperature chamber using a blower or the like. The entire decorative laminated structure is then heated by placing it in the high-temperature chamber.

[0147] In the peeling method according to this embodiment, step S2 may, in one aspect, involve bringing a heating fluid into contact with the decorative film of the decorative laminated structure to heat the decorative laminated structure from the surface side of the decorative film.

[0148] In this embodiment, as an example, a heating medium such as hot water or hot oil is heated to a predetermined temperature, and the heated heating medium is brought into contact with the decorative film provided on the decorative laminated structure. Then, the decorative laminated structure may be heated from the surface side of the decorative film by spraying hot water or hot oil onto it. Another example of this embodiment involves heating the decorative laminated structure from the surface side of the decorative film using non-contact heating means such as a heat gun, high-pressure washer, steam sprayer, infrared heater, and heating lamp. Specifically, when heating the decorative laminated structure using a heat gun, for example, a heat gun having a heater, fan, and motor is used, and hot air heated to a predetermined temperature is sent out from the fan, and the decorative laminated structure is heated from the surface side of the decorative film by blowing the sent hot air onto it.

[0149] The following describes a method for peeling the decorative film from the decorative laminated structure according to this embodiment, with reference to the drawings. In the drawings, some parts are enlarged or reduced in size for ease of explanation. The following description will mainly explain the differences from the decorative laminated structure 200 according to the second embodiment, and redundant explanations will be omitted or simplified. Components similar to those in the decorative laminated structure 200 according to the second embodiment will be given the same reference numerals, and their explanations will be omitted or simplified. The following describes an embodiment in which the decorative film is peeled from the decorative laminated structure by heating the decorative laminated structure using a heat gun as an example of a non-contact heating means.

[0150] Figures 7(A), 7(B), and 7(C) show schematic diagrams illustrating an example of the peeling method according to this embodiment.

[0151] (Process S1) Step S1 is a step of preparing the decorative laminated structure described in the second embodiment. In Figure 7(A), the decorative laminated structure 200 described in the first aspect of the second embodiment is prepared as the decorative laminated structure to be peeled off. A specific example of the decorative laminated structure 200 is as described above.

[0152] (Process S2) Step S2 is a step in which the decorative laminated structure prepared in step S1 is heated. In Figure 7(B), a heat gun 80 is used as a heating means for heating the decorative laminated structure 200. As shown in Figure 7(B), hot air 82 is sprayed from the nozzle of the heat gun 80, and the sprayed hot air 82 is blown onto the first main surface 40A of the laminate layer 40, which is the surface of the decorative film 120 on the decorative laminated structure 200. As a result, the decorative laminated structure 200 is heated from the decorative film 120 side.

[0153] The heating conditions for heating the decorative laminated structure 200 are not particularly limited. The heating conditions for heating the decorative laminated structure 200 should at least be such that the adherend 60 and the decorative film 120 can be separated. The temperature of the hot air 82 used to heat the decorative laminated structure 200 is not particularly limited and may be, for example, 60°C or higher, 80°C or higher, 90°C or higher, 100°C or higher, or 110°C or higher. The upper limit of the temperature of the hot air 82 when heating the decorative laminated structure 200 is not particularly limited, and should be within a temperature range in which at least the adherend 60 and the decorative film 120 can be separated and the decorative film 120 can be peeled off from the decorative laminated structure 200. The time for heating the decorative laminated structure 200 is not particularly limited and may be, for example, 5 seconds or more, 10 seconds or more, 30 seconds or more, or 1 minute or more. The time for heating the decorative laminated structure 200 is not particularly limited and may be, for example, 1 hour or less, 30 minutes or less, 10 minutes or less, or 5 minutes or less.

[0154] (Process S3) Step S3 is a step in which the decorative film 120 is separated and removed from the decorative laminated structure 200 by peeling it off from the adherend 60 after the decorative laminated structure 200 has been heated in step S2 and before it has cooled down to the ambient temperature of the peeling work environment.

[0155] As shown in Figure 7(C), the decorative laminated structure 200 is heated by blowing hot air 82 from the decorative film 120 side, after which the adherend 60 and the decorative film 120 are separated. The means for separating the adherend 60 and the decorative film 120 can be a separation device such as a peeling device (not shown). The separation device is not particularly limited as long as it can separate the adherend 60 and the decorative film 120. Furthermore, the separation of the adherend 60 and the decorative film 120 may be done by hand without using a peeling device.

[0156] After heating the decorative laminated structure 200 by blowing hot air 82 from the decorative film 120 side, the temperature of the heated decorative laminated structure 200 decreases over time. The adherend 60 and the decorative film 120 are separated before the temperature drops to the ambient temperature of the peeling work environment. The ambient temperature of the peeling work environment is not particularly limited, but for example, it may be 40°C. From the viewpoint of easily peeling the decorative film 120 from the decorative laminated structure 200, it is preferable to peel the adherend 60 and the decorative film 120 while the temperature of the heated decorative laminated structure 200 is still small. The temperature when peeling the adherend 60 and the decorative film 120 is preferably higher than 40°C, measured from the first main surface 40A of the laminate layer 40, and may be 60°C or higher, 80°C or higher, 90°C or higher, 100°C or higher, or 110°C or higher.

[0157] (Effects of the third embodiment) According to this embodiment, the following effects can be achieved. (1C): The decorative laminated structure 200 made using the decorative film 120 is equipped with the adhesive layer 10 described in the first embodiment. Therefore, when the decorative film 120 is separated and removed from the decorative laminated structure 200, adhesive residue on the adherend 60 after the decorative film 120 has been peeled off from the adherend 60 is suppressed. (2C): When the decorative film 120 is separated and removed from the decorative laminated structure 200, the amount of adhesive residue left on the adherend 60 after the decorative film 120 has been peeled off from the adherend 60 is suppressed, so the adherend 60 is easy to reuse after the decorative film 120 has been separated and removed from the adherend 60.

[0158] [Variations of the Embodiment] The present invention is not limited to the embodiments described above, and any modifications or improvements that can achieve the objectives of the present invention are included in the present invention. [Examples]

[0159] Hereinafter, the present invention will be described in further detail with reference to Examples. The present invention is in no way limited to these Examples.

[0160] [Production of Decorative Film] Adhesive sheets as decorative films of each Example and each Comparative Example were produced according to the following procedure. In the following Examples and Comparative Examples, "parts by mass" refer to parts by mass in terms of solid content, unless otherwise specified.

[0161] <Example 1> (a1) Synthesis of Silyl Group-Containing Resin In a reaction vessel, 206 parts by mass of N-aminoethyl-γ-aminopropylmethyldimethoxysilane and 172 parts by mass of methyl acrylate were reacted at 80°C for 10 hours with stirring and mixing under a nitrogen atmosphere to obtain a silylating agent.

[0162] In a separate reaction vessel, 1000 parts by mass of polyoxypropylene diol (manufactured by AGC Inc., PMLS4015, molecular weight 15000), 24.6 parts by mass of isophorone diisocyanate (NCO / OH ratio = 1.7), and 0.05 parts by mass of dibutyltin dilaurate were reacted at 85°C for 7 hours with stirring and mixing under a nitrogen atmosphere, to obtain a urethane prepolymer in which the main component of the main chain is polyoxypropylene and urethane bonds are introduced into the main chain.

[0163] To 1000 parts by mass of the urethane prepolymer obtained above, 42.1 parts by mass of the silylating agent obtained above was added, and the mixture was reacted at 80°C for 1 hour with stirring and mixing under a nitrogen atmosphere, to obtain a silyl group-containing resin. The absorption of isocyanate groups at 2265 cm by IR -1 ) was used to confirm the progress of the reaction based on the degree of disappearance. The obtained silyl group-containing resin had two methoxy groups as hydrolyzable silyl groups at both terminals of the main chain, the main component of the main chain was polyoxypropylene, and urethane bonds were introduced into the main chain. The hydrolyzable silyl group is represented by the following formula (11A).

[0164] [Chemical Formula]

[0165] (a2) Preparation of adhesive composition A fluorine catalyst solution was prepared by dissolving 1 part by mass of boron trifluoride monoethylamine complex (containing 59% by mass of boron trifluoride) in 9 parts by mass of 3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM903). 100 parts by mass of the silyl group-containing resin obtained above and 42 parts by mass of terpene phenol-based tackifying resin (manufactured by Yasuhara Chemical Co., Ltd., YS Polystar T-130, softening point 130°C) were mixed and stirred until nearly homogeneous. Then, 1 part by mass of the fluorine catalyst solution prepared above was mixed into this mixture and stirred until nearly homogeneous to prepare an adhesive composition.

[0166] (a3) Preparation of substrate with laminate layer A laminated film (Denka Co., Ltd., "Denka DX Film DX-14S30", 30 μm thick) mixed with polyvinylidene fluoride (PVDF) as a laminate layer was prepared. In addition, a polyvinyl chloride film (degree of polymerization 800, 110 μm thick) mixed with carbon black was prepared as a base material. The outer surface, which would become the second main surface of the laminated film, was dry-laminated to the outer surface, which would become the first main surface of the polyvinyl chloride film (PVC) by heat fusion to produce a base material with a laminated layer (hereinafter referred to as the laminated base material).

[0167] (a3) Preparation of adhesive sheets The adhesive composition prepared above was melt-coated onto the release surface of a release liner (polyethylene laminate paper with release treatment, 175 μm thick) using a hot-melt coater, forming a 50 μm thick adhesive layer on the release surface of the release liner, thus obtaining a release liner with an adhesive layer. Subsequently, the surface of the polyvinyl chloride film of the laminated substrate was bonded to the exposed adhesive surface of the adhesive layer formed on the release liner to obtain a decorative film. The obtained decorative film was cured for 7 days under conditions of 40°C and 80% RH to produce an adhesive sheet as a decorative film in which the release liner, adhesive layer (thickness: 50 μm), and laminated substrate (substrate, laminate layer) were laminated in this order. The silyl group-containing resin contained in the adhesive layer of the obtained decorative film was pre-moisturized.

[0168] <Example 2> In the preparation of the adhesive composition (a2) in Example 1, the mixture was changed to a mixture obtained by mixing 100 parts by mass of a silyl group-containing resin, 42 parts by mass of a terpene phenol-based tackifying resin (Yashara Chemical Co., Ltd., YS Polystar T-130), and 48 parts by mass of an acrylic-based tackifying resin (Seiko PMC Co., Ltd., Hyros ATF-2377, weight-average molecular weight Mw: 3200, softening point 135°C), and stirring until it became nearly homogeneous. Otherwise, an adhesive sheet as a decorative film was prepared in the same manner as in Example 1.

[0169] <Example 3> (a3) In the preparation of the adhesive sheet, an adhesive sheet as a decorative film was prepared in the same manner as in Example 1, except that the polyvinyl chloride film used as the base material was laminated to the adhesive surface of the adhesive layer instead of the laminated base material.

[0170] <Example 4> (a3) In the preparation of the adhesive sheet, the polyvinyl chloride film as the base material was laminated to the adhesive surface of the adhesive layer instead of the laminated base material, and the adhesive sheet as a decorative film was prepared in the same manner as in Example 2.

[0171] <Comparative Example 1> (b1) Preparation of adhesive composition An acrylic resin was obtained by polymerizing 90 parts by mass of butyl acrylate, 1 part by mass of vinyl acetate, and 9 parts by mass of acrylic acid. The weight-average molecular weight Mw, measured using gel permeation chromatography (GPC) (GPC measurement), was 500,000 (500,000). An adhesive composition was prepared by mixing 100 parts by mass of the obtained acrylic resin with 0.05 parts by mass of an epoxy crosslinking agent (TETRAD-C, manufactured by Mitsubishi Gas Chemical Company, Inc.) and diluting it with toluene (solvent).

[0172] (b2) Preparation of adhesive sheets (a3) In the preparation of the adhesive sheet, an adhesive sheet as a decorative film was obtained in the same manner as in Example 1, except that the adhesive composition prepared with the above (b1) adhesive composition was applied to the release surface of the release liner using a knife coater to form an adhesive layer so that the thickness after drying was 20 μm.

[0173] <Comparative Example 2> (b1) An adhesive sheet as a decorative film was obtained in the same manner as in Comparative Example 1, except that the epoxy crosslinking agent was changed to 0.25 parts by mass in the preparation of the adhesive composition.

[0174] <Comparative Example 3> (a3) In the preparation of the adhesive sheet, an adhesive sheet as a decorative film was prepared in the same manner as in Comparative Example 1, except that the polyvinyl chloride film used as the base material was laminated to the adhesive surface of the adhesive layer instead of the laminated base material.

[0175] <Comparative Example 4> (a3) In the preparation of the adhesive sheet, the polyvinyl chloride film as the base material was laminated to the adhesive surface of the adhesive layer instead of the laminated base material, in the same manner as in Comparative Example 2, to prepare the adhesive sheet as a decorative film.

[0176] [Adhesion at room temperature (PsL)] In accordance with JIS Z0237:2022, the adhesive strength was measured by peeling the adhesive sheet from a stainless steel test plate at a 180° angle. Specifically, the adhesive sheets prepared in each example and comparative example were cut to a width of 25 mm, the release liner was peeled off to expose the adhesive layer, and the adhesive side of the adhesive layer was attached to a SUS304 stainless steel plate (SUS304 steel plate, hereinafter referred to as SUS plate), and pressed down once back and forth with a roller with a mass of 2000 g. After standing for 20 minutes in an environment of 23°C and 50% RH, the sample was peeled from the SUS304 at a 180° angle at a peeling speed of 300 mm / min using a Tensilon universal material tester (manufactured by A&D Co., Ltd., "RTG-1210") in the same environment, and the room temperature adhesive strength (PsL) was measured. The results are shown in Table 1.

[0177] [High temperature adhesive strength (PsH)] In measuring the "room temperature adhesive strength," the high-temperature adhesive strength (PsH) was measured in the same manner as for the "room temperature adhesive strength," except that after pressing with a roller for one back-and-forth motion, the material was left to stand in a 100°C environment for 20 minutes, and then peeled off in a 100°C environment. The results are shown in Table 1.

[0178] [Tensile elongation (at room temperature)] The adhesive sheets prepared in each example and comparative example were cut to a width of 10 mm and a length of 100 mm to be used as samples for tensile elongation measurement. The release liner was peeled off the samples, and they were left standing for 5 minutes in an environment of 23°C and 50% RH. Under the same conditions, the samples were stretched at a tensile speed of 300 mm / min using a Tensilon universal material tester (A&D Company, Limited, "RTG-1210"), and the elongation of the samples at a tensile strength of 10 N was measured. The results are shown in Table 1.

[0179] [Tensile elongation (high temperature)] The adhesive sheets prepared in each example and comparative example were cut to a width of 10 mm and a length of 100 mm to serve as samples for tensile elongation measurement. The release liner was peeled off the samples, and they were left standing in an 80°C environment for 5 minutes. Under the same conditions, the samples were stretched at a tensile speed of 300 mm / min using a Tensilon universal material tester (A&D Co., Ltd., "RTG-1210"), and the elongation of the samples at a tensile strength of 1 N was measured. The results are shown in Table 1.

[0180] [Easy peelability] The adhesive sheets prepared in each example and comparative example were cut to 7cm x 5cm, the release liner was peeled off, and the adhesive side of the exposed adhesive layer was attached to a 7cm x 14cm x 1mm SUS plate to be used as a sample for the peelability test. The obtained samples were left to stand for 24 hours under conditions of 23°C and 50%RH, and then heated for 30 seconds (set temperature 100°C) with a heat gun (Ryobi Corporation, "Ryobi Hot Air Gun HAG-1550"). After that, the adhesive sheets were peeled off from the SUS plate. The peelability was evaluated according to the evaluation criteria below. The results are shown in Table 1. <Evaluation Criteria> A: The adhesive sheet can be easily peeled off the SUS plate. B: The adhesive sheet can be peeled off the SUS plate, but the base material stretches, resulting in lower peelability than evaluation A. F: The adhesive sheet cannot be peeled off the SUS plate.

[0181] [Leaves adhesive residue] After evaluating the ease of peeling, the areas where the adhesive sheet had been applied were visually inspected to check for any remaining adhesive, and the adhesive residue was evaluated according to the following evaluation criteria. <Evaluation Criteria> A: No adhesive residue remains on the SUS plate, and no glue residue is left behind. F: Adhesive residue remained on the SUS plate, resulting in glue residue.

[0182] [Table 1]

[0183] The room-temperature adhesive strength of Comparative Example 1 and Comparative Example 3 was similar to that of Examples 1 and 3, respectively, but the high-temperature adhesive strength was higher than that of Examples 1 and 3, respectively. Furthermore, the ratio of room-temperature adhesive strength to high-temperature adhesive strength (PsH / PsL) exceeded 0.2, indicating that the decrease in high-temperature adhesive strength relative to room-temperature adhesive strength was small. In peelability tests of decorative laminated structures prepared by attaching the adhesive sheets of Comparative Example 1 and Comparative Example 3 to a SUS plate, cohesive failure occurred in the adhesive layer attached to the SUS plate, resulting in adhesive residue on the SUS plate.

[0184] The high-temperature adhesive strength of Comparative Examples 2 and 4 was equivalent to or lower than that of each example. Furthermore, the ratio of room-temperature adhesive strength to high-temperature adhesive strength exceeded 0.2, indicating that the decrease in high-temperature adhesive strength relative to room-temperature adhesive strength was small due to the low room-temperature adhesive strength. In the peelability test of Comparative Examples 2 and 4, peeling was possible at the interface between the adhesive layer of the adhesive sheet and the SUS plate, and no adhesive residue was left on the SUS plate. However, the room-temperature adhesive strength when using the adhesive sheets of Comparative Examples 2 and 4 was significantly lower than that of Examples 1 and 2, so sufficient adhesive strength to firmly adhere as a decorative film could not be obtained, and it peeled off easily even when attached to the substrate.

[0185] In contrast, when using the adhesive sheets of each example, excellent room-temperature adhesive strength values ​​were observed, and the high-temperature adhesive strength decreased, resulting in a ratio of room-temperature adhesive strength to high-temperature adhesive strength (PsH / PsL) of 0.2 or less. Furthermore, in peelability tests of decorative laminated structures prepared by attaching the adhesive sheets of each example to a SUS plate, peeling was possible at the interface between the adhesive layer of the adhesive sheet and the SUS plate, and no adhesive residue was left on the SUS plate. Therefore, it can be seen that the adhesive sheets of each example, which have an adhesive layer containing a silyl group-containing resin with hydrolyzable silyl groups having a specific structure and a terpene phenol-based tackifying resin, maintain high adhesive strength at room temperature to the SUS plate as the adherend, while suppressing adhesive residue when peeling the adhesive sheet as a decorative film from the decorative laminated structure, compared to the adhesive sheets of each comparative example which have an acrylic adhesive layer. The high-temperature adhesive strength of the adhesive sheets of the examples was measured at 60°C, 80°C, and 120°C, and the ratio of room-temperature adhesive strength to high-temperature adhesive strength was calculated, all of which satisfied a value of 0.2 or less.

[0186] Furthermore, in peelability tests of decorative laminated structures prepared by attaching the adhesive sheets of each embodiment to a SUS plate, the adhesive sheets of Embodiments 1 and 3, which have a laminated substrate with a laminate layer, exhibited superior peelability between the adherend and the adhesive sheet compared to the adhesive sheets of Embodiments 2 and 4, which have a substrate without a laminate layer, because the substrate elongation was smaller.

[0187] From the results above, it was confirmed that the adhesive sheets used as decorative films in each embodiment maintained high adhesive strength to the adherend at room temperature while suppressing adhesive residue when peeled off from the adherend. [Explanation of symbols]

[0188] 10...Adhesive layer, 10A...First main surface (adhesive layer), 10B...Second main surface (adhesive layer), 20...Release liner, 20A...First main surface (release liner), 30...Base material, 30A...First main surface (base material), 30B...Second main surface (base material), 40...Laminate layer, 41...First laminate layer, 42...Second laminate layer, 40A...First main surface (laminate layer), 40B...Second Main surface (laminate layer), 50...Adhesive layer for laminate layer, 50A...First main surface (adhesive layer for laminate layer), 50B...Second main surface (adhesive layer for laminate layer), 60...Substrate, 60A...First main surface (substrate), 80...Heat gun (example of heating means), 82...Hot air, 100, 110, 120, 130, 140...Decorative film, 200...Decorative laminated structure.

Claims

1. A decorative film having easy peelability, It comprises a base material and an adhesive layer, The adhesive layer comprises a moisture-cured product of a silyl group-containing resin and a terpene phenol-based tackifying resin. The silyl group-containing resin is The main chain has a polyoxyalkylene structure, In part of the main chain or side chains, It has both urethane and urea bonds, or Having either the urethane bond or the urea bond, The main chain has hydrolyzable silyl groups represented by the following formula (1) at both ends. Decorative film. 【Chemistry 1】 (In the above formula (1), X １ and X ２ Each of these is independently a hydroxyl group or an alkoxy group, R is an alkyl group having 1 to 20 carbon atoms, and * indicates the bond position.

2. In the decorative film according to claim 1, At 80°C, when the tensile load is 1 N / 10 mm, the elongation of the decorative film in the MD direction and the CD direction is 5.0% or less, respectively. Decorative film.

3. In the decorative film according to claim 1 or claim 2, The content of the terpene phenol-based tackifying resin is 20 parts by mass or more and 100 parts by mass or less, based on 100 parts by mass of the silyl group-containing resin. Decorative film.

4. In the decorative film according to claim 1 or claim 2, The adhesive layer further comprises an acrylic tackifying resin, The content of the acrylic tackifying resin is 1 part by mass or more and 100 parts by mass or less per 100 parts by mass of the silyl group-containing resin. Decorative film.

5. In the decorative film according to claim 4, The weight-average molecular weight Mw of the acrylic tackifying resin is 300 or more and 10,000 or less. Decorative film.

6. In the decorative film according to claim 1 or claim 2, The substrate comprises at least one resin selected from the group consisting of polyvinyl chloride resin, urethane resin, and olefin resin. Decorative film.

7. In the decorative film according to claim 1 or claim 2, The adhesive layer is provided with a release liner on the side opposite to the side on which the substrate is provided. Decorative film.

8. In the decorative film according to claim 1 or claim 2, The substrate comprises a laminate layer provided on the side opposite to the side on which the adhesive layer is provided. Decorative film.

9. In the decorative film according to claim 8, The laminate layer contains a fluororesin, Decorative film.

10. In the decorative film according to claim 1 or claim 2, The adhesive strength of the decorative film to the adherend at 23°C when peeled off at 180°C, measured in accordance with the measurement method specified in JIS Z0237:2022, is defined as the room temperature adhesive strength PsL. When the high-temperature adhesive strength PsH of the decorative film on the adherend at a temperature of 60°C or higher, measured in accordance with the measurement method specified in JIS Z0237:2022, The ratio of the high-temperature adhesive strength PsH to the room-temperature adhesive strength PsL satisfies the following formula (Equation 1): Decorative film. 0.2 ≥ (PsH / PsL) > 0 ... (Math 1)

11. A decorative laminated structure, A substrate comprising at least one material selected from the group consisting of metal, glass, and resin, The decorative film according to claim 1 or claim 2 is attached to the adherend, Decorative laminated structure.

12. A peeling method for peeling a decorative film from a decorative laminated structure, A step of preparing a decorative laminated structure comprising: a substrate comprising at least one material selected from the group consisting of metal, glass, and resin; and a decorative film according to claim 1 or claim 2 attached to the substrate; A step of heating the decorative laminated structure, The process includes a step of separating and removing the decorative film from the adherend after heating the decorative laminated structure, while the temperature is decreasing to the ambient temperature of the peeling work environment. Method of removal.

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