Laminated sheet, laminated sheet roll, release film, and method for processing laminated sheet

Abstract

To provide a laminated sheet in which a release film is laminated on an adhesive face, which has excellent thermoforming properties, is suitable for a use form in which the release film is peeled after being thermally formed in advance and the adhesive face is adhered onto an adherend, and can impart an excellent external appearance.SOLUTION: Provided is a laminated sheet including: a sheet-shaped adhesive body, a first film laminated on a first face of the adhesive body; and a second film laminated on a second face of the adhesive body. The second film is a release film that includes a resin film and a release treatment layer provided on at least a surface of the resin film closer to the adhesive body, and satisfies the following conditions: Young's modulus at 85°C is 500 MPa or more; and Young's modulus at 120°C is 500 MPa or less. Further, the maximum height Rz of the second face of the adhesive body is 1000nm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a release film, a laminate sheet including the release film, a roll around which the laminate sheet is wound, and a method for processing the laminate sheet. [Background technology]

[0002] Generally, pressure-sensitive adhesives (also referred to as pressure-sensitive adhesives; the same applies hereinafter) are soft solids (viscoelastic bodies) at temperatures around room temperature and have the property of easily adhering to an adherend when pressure is applied. Utilizing this property, pressure-sensitive adhesives, typically in the form of pressure-sensitive adhesive sheets containing a layer of the pressure-sensitive adhesive, are widely used in various industrial fields, from home appliances to automobiles and office automation equipment.

[0003] Depending on the application, pressure-sensitive adhesive sheets are attached to the surface of an adherend having a non-planar shape (three-dimensional shape). Patent Document 1 proposes attaching a double-sided pressure-sensitive adhesive sheet that has been pre-formed to have a non-planar shape to the adherend in order to facilitate the attachment work and prevent the occurrence of wrinkles during attachment when attaching a pressure-sensitive adhesive sheet to the surface of such a non-planar shape. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-029139 Summary of the Invention [Problem to be solved by the invention]

[0005] However, before being attached to an adherend, an adhesive sheet is usually processed, distributed, stored, etc. in the form of an adhesive sheet with a release liner, in which the adhesive surface (the surface that is attached to the adherend) is protected by laminating a release liner. However, when an adhesive sheet with a release liner that has a typical planar shape (flat shape) is formed into a non-planar shape by heat pressing or the like, the release liner may be damaged, such as torn, by the stress during thermoforming, or the release liner may partially lift off from the adhesive surface during thermoforming or over time thereafter, resulting in a poor appearance and a decrease in the protective reliability of the adhesive surface.

[0006] Furthermore, in applications where a good appearance is required when attached to an adherend, a highly smooth adhesive surface is required in which orange peel and distortion are highly suppressed. It is desirable that such a highly smooth adhesive maintains a smooth adhesive surface that is free from distortion and can provide a good appearance during storage after being molded into a non-planar shape by heat pressing or the like as described above.

[0007] Therefore, an object of the present invention is to provide a laminate sheet having a release film laminated on its adhesive surface, which has good thermoformability, is suitable for use in a mode in which the release film is peeled off after thermoforming and the adhesive surface is attached to an adherend, and can impart a good appearance. Another related object is to provide a laminate sheet roll in which the laminate sheet is wound. Yet another related object is to provide a release film suitable as a component of the laminate sheet. Yet another related object is to provide a method for processing the laminate sheet into a non-planar shape. [Means for solving the problem]

[0008] According to this specification, a laminated sheet is provided, which includes a sheet-shaped adhesive body, a first film laminated on a first surface of the adhesive body, and a second film laminated on a second surface of the adhesive body. The second film includes a resin film and a release treatment layer provided on at least the adhesive body side surface of the resin film, and has a Young's modulus at 85°C (hereinafter referred to as "Young's modulus E 85" or simply "E 85 ") is 500 MPa or more; and Young's modulus at 120°C (hereinafter referred to as "Young's modulus E 120 " or simply "E 120 The release film satisfies the requirement that the surface roughness (Rz) of the second surface of the pressure-sensitive adhesive body is 500 MPa or less. In addition, the maximum height Rz of the second surface of the pressure-sensitive adhesive body is 1000 nm or less.

[0009] The laminated sheet having such a configuration has a Young's modulus E 120 The Young's modulus E of the second film is limited to 500 MPa or less, which results in good thermoformability. For example, the second film is easily deformed during thermoforming, so that the second film is less likely to be damaged. Furthermore, the second film has a release treatment layer on the surface of the adhesive body side, which allows the peel force of the second film from the adhesive body to be appropriately controlled. Furthermore, the Young's modulus E of the second film is 85 Since the compressive strength is 500 MPa or more, it is easy to appropriately form a release treatment layer on the resin film used to produce the second film. Therefore, the laminate sheet has good formability (easily formable) and is suitable for use in an embodiment in which the release film is peeled off from the laminate sheet after molding and the adhesive surface is attached to an adherend. Furthermore, since the second surface of the adhesive body has smoothness with a maximum height Rz of 1000 nm or less, it can provide a good appearance based on the smoothness even after being molded into a non-planar shape by heat pressing or the like and then attached to an adherend.

[0010] In some preferred embodiments, the adhesive body has a stress of 50 N / cm when measured after being stretched 300% at a temperature of 23°C, a stretching speed of 200 mm / min, and being held at the 300% stretched position for 150 seconds. 2 The stress measured under these conditions is considered to correspond to the residual stress after the deformation load. An adhesive body in which the above-mentioned stress (residual stress) is equal to or less than a predetermined value is easy to relax the stress after being molded into a non-planar shape by heat pressing or the like, so that the adhesive body is less likely to be distorted and is easy to maintain a good appearance.

[0011] The laminate sheet disclosed herein has a peel strength (hereinafter referred to as "peeling strength P") of the second film from the adhesive body after heat pressing at 120°C for 1 minute. 2A It is preferable that the peeling force P is 0.10 N / 50 mm or more and 5 N / 50 mm or less. 2A A laminate sheet having a viscosity within the above range allows the second film to be easily peeled from the adhesive surface, and can effectively prevent the second film from partially lifting off the adhesive surface during thermoforming or over time thereafter.

[0012] In some embodiments, the first film is a support film adhered to the first surface of the pressure-sensitive adhesive body. The laminate sheet of such embodiments can be understood as a single-sided PSA sheet with a release film, including a single-sided PSA sheet having a pressure-sensitive adhesive body on the support film as a non-releasable substrate, and a second film as a release film releasably laminated on the adhesive surface of the single-sided PSA sheet (the second surface of the pressure-sensitive adhesive body). The single-sided PSA sheet with a release film can be thermoformed into an appropriate shape (e.g., a non-planar shape) corresponding to the surface shape of the adherend, and then the release film can be peeled off and the single-sided PSA sheet can be attached to the surface of the adherend, thereby easily forming a structure in which the support film is bonded to the adherend via the PSA. Note that when the surface shape of the adherend is non-planar, the "appropriate non-planar shape corresponding to the surface shape of the adherend" means a shape that is closer to the non-planar shape of the adherend surface than a planar shape (i.e., a shape that is easier to conform to the non-planar shape of the adherend surface than a planar shape), and is not limited to a shape that is completely identical to the non-planar shape of the adherend surface. The same applies to the following explanation.

[0013] In some other embodiments of the laminate sheet, the first film is a release film. In these laminate sheets, the first film is releasably laminated to a first surface of the pressure-sensitive adhesive body, and the second film is releasably laminated to a second surface of the pressure-sensitive adhesive body. Therefore, the pressure-sensitive adhesive body can be understood as a double-sided pressure-sensitive adhesive sheet in which both the first and second surfaces are adhesive surfaces. Furthermore, the laminate sheet can be understood as a double-sided pressure-sensitive adhesive sheet with a release film, in which the first and second surfaces of the double-sided pressure-sensitive adhesive sheet are protected by first and second films. The double-sided PSA sheet with a release film can be preferably used, for example, in an embodiment in which the sheet is thermoformed into an appropriate shape (e.g., a non-planar shape) corresponding to the surface shape of the adherend, the first film is peeled off, and the first side of the adhesive body is attached to the surface of the first adherend, and then the second film is peeled off, and the second side of the adhesive body is attached to the surface of the second adherend. Alternatively, the double-sided PSA sheet with a release film can be produced by peeling off the first film and attaching the first side of the adhesive body to a non-releasable member (e.g., a resin film) to produce a single-sided PSA sheet with a release film having a configuration in which the member, the adhesive body, and the second film are laminated in this order, and the single-sided PSA sheet with a release film is thermoformed into an appropriate shape (e.g., a non-planar shape) corresponding to the surface shape of the adherend, and then the second film is peeled off, and the second side of the adhesive body is attached to the surface of the adherend, thereby easily forming a structure in which the member is bonded to the adherend via the adhesive body. The first adherend surface and the second adherend surface may be surfaces of two or more mutually different (separate) adherends, or may be surfaces at different positions on a single adherend.

[0014] In a laminate sheet in an embodiment in which both the first and second films are release films, the laminate sheet has a peel strength of the first film from the adhesive body (hereinafter referred to as "peeling strength P 1B ") is the peeling force of the second film from the adhesive body (hereinafter referred to as "peeling force P 2BThe laminated sheet configured in this manner is typically used in a manner in which the first film is peeled off from the adhesive body before the second film, and can suitably prevent the adhesive body from floating up from the second film when the first film is peeled off.

[0015] In some preferred embodiments, the adhesive body is a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive. Generally, compared with a substrate-attached adhesive body having a pressure-sensitive adhesive on both sides of a substrate (core material), an adhesive body composed of the pressure-sensitive adhesive layer (not including a substrate, i.e., substrate-less) exhibits higher deformability and flexibility. Therefore, a substrate-less adhesive body is advantageous from the viewpoint of thermoformability of the laminated sheet, and is also preferable from the viewpoint of adhesion of the adhesive body to the surface of the adherend.

[0016] The laminate sheet disclosed herein can be provided in the form of a laminate sheet roll (also simply referred to as a "roll body") in which the laminate sheet is wound. Such a roll body is easy to handle during storage and transportation and is also advantageous in terms of productivity.

[0017] This specification also provides a release film that includes a resin film and a release treatment layer provided on at least the surface of the resin film facing the pressure-sensitive adhesive layer, and that satisfies the following conditions: Young's modulus at 85°C is 500 MPa or more; and Young's modulus at 120°C is 500 MPa or less, and the maximum height Rz of the surface of the release treatment layer is 1000 nm or less. This release film can be used, for example, as a component of any of the laminate sheets disclosed herein, and more specifically, preferably as at least the second film of the laminate sheet.

[0018] Furthermore, this specification provides a method for processing a laminate sheet, which includes preparing any of the laminate sheets disclosed herein and heating and pressurizing at least a partial region of the laminate sheet to form a non-planar shape. The laminate sheet disclosed herein can be preferably used in such an embodiment that the laminate sheet is formed into a desired non-planar shape by this processing method, the release film is peeled off from the formed laminate sheet, and the pressure-sensitive adhesive surface is attached to an adherend.

[0019] Appropriate combinations of the elements described in this specification may also be included within the scope of the invention for which patent protection is sought by this patent application. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a laminate sheet according to one embodiment. [Figure 2] FIG. 2 is a schematic perspective view illustrating the shape of a lower mold of the molds used in the molding test. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0021] Preferred embodiments of the present invention are described below. Matters necessary for carrying out the present invention other than those specifically mentioned in this specification can be understood by those skilled in the art based on the teachings for carrying out the invention described in this specification and the common general technical knowledge at the time of filing. The present invention can be carried out based on the contents disclosed in this specification and the common general technical knowledge in the relevant field. Furthermore, in the following drawings, components and parts that perform the same function may be denoted by the same reference numerals, and redundant explanations may be omitted or simplified. Furthermore, the embodiments shown in the drawings are schematic for the purpose of clearly explaining the present invention, and do not necessarily accurately represent the size or scale of the actual product provided.

[0022] In this specification, the term "adhesive" refers to a material that, as mentioned above, is in a soft solid (viscoelastic) state in the temperature range around room temperature and has the property of easily adhering to an adherend by pressure. The adhesive referred to here is generally a material having a complex tensile modulus E * (1Hz)<10 7 dyne / cm 2 The material may be a material having the properties satisfying the above (typically, a material having the above properties at 25°C).

[0023] <Example of laminated sheet configuration> The laminated sheet disclosed herein includes a sheet-shaped adhesive body, a first film laminated on a first surface of the adhesive body, and a second film laminated on a second surface of the adhesive layer. The second film is a release film. Here, the release film refers to a film whose surface to be laminated on the adhesive body is a release surface. The first film may be a release film or a non-release film (support film).

[0024] The structure of a laminate sheet according to one embodiment is shown schematically in FIG. 1. This laminate sheet 50 includes an adhesive body 10, a first film 31 laminated on a first surface 10A of the adhesive body 10, and a second film 32 laminated on a second surface 10B of the adhesive body 10. The second film 32 is a release film in which at least the surface facing the adhesive body 10 is a release surface. The surface of the first film 31 facing the adhesive body 10 may be a release surface or a non-release surface. That is, the first film 11 may be a release film or a non-release film (support film). The surfaces of the first and second films 31 and 32 opposite the adhesive body 10 may independently be a release surface or a non-release surface. The adhesive body 10 may be an adhesive layer made of an adhesive (i.e., a substrate-less adhesive body), or may be an adhesive body with a substrate having adhesives on both sides of a substrate (core material). The adhesive contained in the adhesive body 10 may be, for example, a cured product of a photocurable adhesive composition.

[0025] Before use, the laminate sheet may be in the form of a laminate sheet roll (also simply referred to as a "roll body" or, for example, an adhesive sheet roll) in which the laminate sheet is wound. Such a laminate sheet includes, for example, the laminate sheet (a laminate sheet having a laminated structure of a first film / adhesive body / second film) wound around a core (spool). Alternatively, the roll body may be in the form of a so-called coreless type roll body in which the laminate sheet is wound alone. Such a roll body is easy to handle during storage and transportation and is also advantageous in terms of productivity.

[0026] <Second film> The second film in the laminate sheet disclosed herein is a release film including a resin film as a base film and a release-treated layer provided on at least one surface of the resin film. The second film (release film) has a Young's modulus (E 85 ) is 500 MPa or more, and the Young's modulus (E 120 ) is 500 MPa or less.

[0027] As the base film of the second film, a known plastic film having the above Young's modulus E 85 ,E 120 In this specification, a plastic film is typically a non-porous sheet, and is a concept that is distinguished from, for example, nonwoven fabrics (i.e., does not include nonwoven fabrics).

[0028] Examples of resin materials that can be used to form the plastic film include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN); polyolefin resins such as polyethylene (PE), polypropylene (PP), ethylene-propylene copolymers, and ethylene-butene copolymers; cellulose polymers such as diacetyl cellulose and triacetyl cellulose (TAC); acetate resins; polycarbonate (PC); nylon 6, nylon 66, and partially aromatic polyamides. Examples of suitable resin materials include polyamide (PA), polyimides such as transparent polyimide (CPI), polyamideimide (PAI), polyetheretherketone (PEEK), polysulfone-based resins, polyethersulfone (PES)-based resins, cyclic polyolefins such as norbornene-based resins, (meth)acrylic resins, polyvinyl chloride-based resins, polyvinylidene chloride-based resins, polystyrene-based resins, polyvinyl alcohol (PVA)-based resins, ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol copolymers, polyarylate-based resins, and polyphenylene sulfide (PSS). A plastic film formed from one or a mixture of two or more of these resin materials can be used as the base film for the second film. Suitable examples include polyester-based films (e.g., PET films) primarily composed of polyester-based resins, and polyolefin-based films primarily composed of polyolefin-based resins.

[0029] The release treatment layer can be formed by applying a release treatment agent to the base film and curing (drying, crosslinking, reaction, etc.). Examples of the release treatment agent that can be used include known release treatment agents, such as silicone-based release treatment agents, long-chain alkyl-based release treatment agents, fluorine-based release treatment agents, and molybdenum (IV) sulfide. The thickness of the release treatment layer is not particularly limited and can be set so as to exhibit the desired release properties. In some embodiments, the thickness of the release treatment layer is suitably 0.01 μm or more, preferably 0.05 μm or more, and may be 0.08 μm or more. The thickness of the release treatment layer may be, for example, 3 μm or less, 1 μm or less, or 0.5 μm or less.

[0030] The release agent used may be in the form of a solvent, a solventless type, or an aqueous solution (aqueous solution type, water dispersion type), etc. In some embodiments, solvent-based release agents containing release layer-forming components in an organic solvent may be preferably used from the viewpoints of ease of viscosity adjustment and ease of forming a highly homogeneous release treatment layer. The organic solvent may be any one solvent selected from, for example, aliphatic hydrocarbons such as hexane and heptane; alicyclic hydrocarbons such as cyclohexane; aromatic compounds (typically aromatic hydrocarbons) such as toluene and xylene; halogenated alkanes such as 1,2-dichloroethane; ethers such as tert-butyl methyl ether; and ketones such as methyl ethyl ketone; or a mixture of two or more solvents. A release treatment layer can be formed on a resin film by applying a solvent-based release treatment agent to the resin film to be treated and drying the applied agent. For efficient drying, the resin film coated with the solvent-based release treatment agent is dried at, for example, 40°C or higher, preferably 60°C or higher, and more preferably 70°C or higher. The drying temperature is preferably less than 120°C, more preferably 110°C or lower, and may be 100°C or lower or 90°C or lower.

[0031] A suitable example of a release treatment agent is a silicone-based release treatment agent. The silicone-based release treatment agent may be any of addition reaction type, condensation reaction type, ultraviolet curing type, electron beam curing type, etc. In terms of reactivity, performance stability, etc., addition reaction type silicone-based release treatment agents may be preferably used in some embodiments. Addition reaction type silicone-based release treatment agents usually contain an organohydrogenpolysiloxane and an organopolysiloxane having an aliphatic unsaturated group, and may be either solventless or solvent-based. For example, a thermosetting addition reaction type silicone-based release treatment agent that crosslinks and cures by a thermal addition reaction may be preferably used.

[0032] The thermosetting addition reaction type silicone release agent may, for example, be a release agent containing a polysiloxane having a hydrogen atom (H) bonded to a silicon atom (Si) in the molecule (Si-H group-containing polysiloxane) and a polysiloxane containing a functional group (Si-H group-reactive functional group) in the molecule that is reactive with an Si-H bond (covalent bond between Si and H) (Si-H group-reactive polysiloxane). Such a release agent cures by crosslinking caused by an addition reaction between the Si-H group and the Si-H group-reactive functional group.

[0033] In the above-mentioned Si-H group-containing polysiloxane, the Si bonded to H may be either Si in the main chain or Si in the side chain. Polysiloxanes containing two or more Si-H groups in the molecule are preferred. Examples of polysiloxanes containing two or more Si-H groups include dimethylhydrogensiloxane polymers such as poly(dimethylsiloxane-methylsiloxane).

[0034] On the other hand, the Si-H group-reactive polysiloxane may be a polysiloxane in which a Si-H group-reactive functional group or a side chain containing such a functional group is bonded to Si (e.g., Si at the end of the main chain, Si inside the main chain) that forms the main chain (skeleton) of the siloxane-based polymer. Among these, polysiloxanes in which the Si-H group-reactive functional group is directly bonded to Si in the main chain are preferred. Also preferred are polysiloxanes containing two or more Si-H group-reactive functional groups in the molecule. Examples of the Si-H group-reactive functional group include alkenyl groups such as vinyl and hexenyl. Examples of the siloxane-based polymer forming the main chain portion include polydialkylsiloxanes such as polydimethylsiloxane, polydiethylsiloxane, and polymethylethylsiloxane (the two alkyl groups may be the same or different); polyalkylarylsiloxanes; and polymers obtained by polymerizing multiple Si-containing monomers, such as poly(dimethylsiloxane-methylsiloxane). A particularly preferred main chain polymer is polydimethylsiloxane.

[0035] In some embodiments, a thermosetting addition reaction type silicone release agent containing a polysiloxane containing two or more Si-H groups in the molecule and a polysiloxane containing two or more Si-H group-reactive functional groups in the molecule can be preferably used. The mixing ratio of the Si-H group-containing polysiloxane and the Si-H group-reactive polysiloxane contained in the release agent is not particularly limited as long as the release agent is sufficiently cured and the above-mentioned silicone migration amount can be achieved, but it is preferable to select the number of moles of Si in the Si-H groups, X, and the number of moles of Si-H group-reactive functional groups, Y, so that X≧Y, and usually X:Y is preferably about 1:1 to 2:1 (more preferably 1.2:1 to 1.6:1).

[0036] The addition reaction type silicone release agent may contain a catalyst to accelerate the crosslinking reaction. Examples of such catalysts include platinum catalysts such as platinum fine particles, chloroplatinic acid and its derivatives. The amount of catalyst added is not particularly limited, but is selected from the range of 0.005 to 5 parts by weight (preferably 0.01 to 1 part by weight) per 100 parts by weight of the Si-H group-reactive polysiloxane.

[0037] The silicone-based release treatment agent may be a mixture of the above-mentioned components prepared or procured as appropriate, or a commercially available product containing the above-mentioned components. In addition to the above-mentioned components, other known and commonly used additives such as fillers, antistatic agents, antioxidants, ultraviolet absorbers, plasticizers, colorants (dyes, pigments, etc.) may also be added as needed.

[0038] In some other embodiments, a release film having a release treatment layer formed from a long-chain alkyl release agent can be preferably used. Examples of long-chain alkyl release agents include polyvinyl carbamates obtained by reacting a polyvinyl alcohol polymer with a long-chain alkyl isocyanate (e.g., having 8 to 30 carbon atoms), and alkyl urea derivatives obtained by reacting a polyethyleneimine with a long-chain alkyl isocyanate (e.g., having 8 to 30 carbon atoms). Furthermore, long-chain alkyl release agents containing long-chain alkyl materials, such as those described in JP 2016-145341 A, can be used as release agents for release films used in the laminate sheets disclosed herein. This publication is incorporated herein by reference.

[0039] Young's modulus (E 120 ) is 500 MPa or less, as described above, and is preferably 400 MPa or less, but may be 300 MPa or less, 200 MPa or less, 100 MPa or less, or 20 MPa or less. 120 As E decreases, thermoformability tends to improve. 120In some embodiments, the Young's modulus (E 85 ) to be more than the specified value, 120 is suitably 2 MPa or more, preferably 4 MPa or more, may be 10 MPa or more, 70 MPa or more, 150 MPa or more, 250 MPa or more, or may be 350 MPa or more.

[0040] Young's modulus E of the second film 120 The preferred range of E may vary depending on the type of base film. For example, when the base film of the second film is a polyester film, in some embodiments, 120 is preferably 70 MPa or more and 500 MPa or less, and more preferably 150 MPa or more and 400 MPa or less (for example, 150 MPa or more and 300 MPa or less, 250 MPa or more and 400 MPa or less). When the base film of the second film is a polyolefin film, in some embodiments, the E of the second film 120 is preferably 2 MPa or more and 100 MPa or less, and more preferably 2 MPa or more and 20 MPa or less.

[0041] Young's modulus (E 85 ) is 500 MPa or more as mentioned above. For example, E 85 By forming a release treatment layer on a base film having a strength of 500 MPa or more, 85 It is possible to preferably realize a second film that satisfies the above. 85 A base film having a heat resistance of 500 MPa or more is preferred because it is less likely to cause deformation (e.g., waviness, curling, shrinkage, etc.) or poor appearance such as cloudiness even when heated (e.g., heated to a temperature range of about 70°C to 100°C) for the purpose of drying the release agent or promoting crosslinking. In some embodiments, the E of the second film 85 For example, E may be 600 MPa or more, 700 MPa or more, 900 MPa or more, or 1100 MPa or more. 85There is no particular upper limit to E 120 In order to make it easier to keep the E of the second film below the specified value, 85 may be, for example, 2000 MPa or less, 1700 MPa or less, 1500 MPa or less, 1200 MPa or less, or 1000 MPa or less.

[0042] Young's modulus E of the second film 85 The preferred range of E may vary depending on the type of base film. For example, when the base film of the second film is a polyester film, in some embodiments, 85 is preferably 500 MPa or more and 2000 MPa or less, and more preferably 600 MPa or more and 1500 MPa or less (for example, 700 MPa or more and 1200 MPa or less, 900 MPa or more and 1500 MPa or less). When the base film of the second film is a polyolefin film, in some embodiments, the E of the second film 85 is preferably 500 MPa or more and 1500 MPa or less, more preferably 500 MPa or more and 1200 MPa or less (for example, 700 MPa or more and 1500 MPa or less), and may be 900 MPa or more and 1200 MPa or less.

[0043] E of the second film 120 Value of E [MPa] 85 The ratio of the values ​​[MPa], that is, the ratio (E 85 / E 120 ) is typically greater than 1, and is preferably 3 or greater from the viewpoint of achieving a high level of both heat resistance suitable for suppressing appearance defects due to release treatment and ease of deformation during thermoforming, and may be 5 or greater, 20 or greater, 50 or greater, 100 or greater, or 160 or greater. 85 / E 120 ) is not particularly limited in its upper limit, and may be, for example, 500 or less, 300 or less, 150 or less, 80 or less, 40 or less, or 10 or less.

[0044] The ratio of the second film (E85 / E 120 The preferred range of the ratio (E) of the second film may vary depending on the type of base film. For example, when the base film of the second film is a polyester film, in some embodiments, 85 / E 120 ) is preferably 3 or more and 40 or less (for example, 3 or more and 10 or less). When the base film of the second film is a polyolefin-based film, in some embodiments, the ratio (E 85 / E 120 ) is preferably 20 or more and 500 or less, and more preferably 50 or more and 300 or less (for example, 100 or more and 300 or less).

[0045] In some embodiments, the elongation at break of the second film at 120°C (hereinafter, "elongation at break L 120 " or simply "L 120 From the viewpoint of preventing breakage during thermal deformation, the elongation at break L of the second film is suitably 230% or more, preferably 250% or more, may be 300% or more, 400% or more, or may be 500% or more. 120 The upper limit of L of the second film is not particularly limited. 120 may be, for example, 1000% or less, 700% or less, 500% or less, or 400% or less.

[0046] The ratio of the second film (E 85 / E 120 The lower and upper limits of the ratio (E 85 / E 120 The above-mentioned lower and upper limits of the elongation at break of the second film can also be preferably applied to the lower and upper limits of the elongation at break of the first film when the first film is a release film.

[0047] In this specification, the Young's modulus and elongation at break of a film (which may be a first film, a second film, a base film thereof, etc.) are measured by the method described in the Examples below. The Young's modulus and elongation at break can be adjusted by the composition and production method of the film.

[0048] In some embodiments, the maximum height Rz of the release treatment layer surface of the second film is approximately 1000 nm or less. This can increase the smoothness of the adhesive surface (second surface) of the adhesive body. The maximum height Rz is preferably approximately 900 nm or less, more preferably approximately 800 nm or less. In some preferred embodiments, the maximum height Rz is approximately 700 nm or less, and may be approximately 600 nm or less, or may be approximately 500 nm or less (e.g., 450 nm or less). Furthermore, from the viewpoint of ease of production and handleability of the release film, in some embodiments, the maximum height Rz may be, for example, approximately 10 nm or more, approximately 100 nm or more, approximately 200 nm or more, or approximately 300 nm or more. When the maximum height Rz is a predetermined value or more, peeling from the adhesive surface tends to be easier.

[0049] Unless otherwise specified, the maximum height Rz in this specification refers to the maximum height roughness obtained using a non-contact surface roughness measuring device. The non-contact surface roughness measuring device may be an optical interference type surface roughness measuring device, such as the Wyko NT-9100 manufactured by Veeco or an equivalent. The specific measurement procedure and conditions can be set according to the measurement conditions described in the Examples below, or to obtain results equivalent to or corresponding to those obtained using the measurement conditions. The maximum height Rz is calculated as the sum of the height Rp of the highest peak above the mean line of the roughness curve obtained by the surface roughness measurement and the depth Rv of the deepest valley below the mean line.

[0050] The maximum height Rz of the surface of the release treatment layer of the second film can be adjusted by the type and manufacturing method of the base film, the composition of the release treatment layer, the coating method, etc. For example, when using a base film having a smooth surface and a rough surface (e.g., a polyolefin film), the rough surface is usually used as the release surface for releasability, but by forming a release treatment layer on the smooth surface and using the surface of the release treatment layer as the release surface, the above maximum height Rz can be obtained.

[0051] <First Film> The first film in the laminated sheet disclosed herein may be a support film (non-peelable film) adhered to the first surface of the adhesive body constituting the laminated sheet, or may be a release film in which the first surface side of the adhesive body is the release surface.

[0052] In an embodiment in which the first film is a support film, various plastic films can be used as the base film of the support film. Examples of resin materials that can be used to form the plastic film include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN); polyolefin resins such as polyethylene (PE), polypropylene (PP), ethylene-propylene copolymers, and ethylene-butene copolymers; cellulose polymers such as diacetyl cellulose and triacetyl cellulose (TAC); acetate resins; polycarbonate (PC); nylon 6, nylon 66, and partially aromatic polyamides. Examples of suitable plastic films include polyamides (PA), polyimides such as transparent polyimide (CPI), polyamideimides (PAI), polyetheretherketone (PEEK), polysulfone-based resins, polyethersulfone (PES)-based resins, cyclic polyolefins such as norbornene-based resins, (meth)acrylic resins, polyvinyl chloride-based resins, polyvinylidene chloride-based resins, polystyrene-based resins, polyvinyl alcohol (PVA)-based resins, ethylene-vinyl acetate copolymers (EVA), ethylene-vinyl alcohol copolymers, polyarylate-based resins, and polyphenylene sulfide (PSS). Plastic films formed from one or a mixture of two or more of these resin materials can be used as the base film for the support film. Among these, preferred plastic films include cellulose-based films such as diacetyl cellulose film and triacetyl cellulose (TAC) film, polyester-based films such as PET film, polyimide-based films such as transparent polyimide (CPI) film, and polyethersulfone (PES)-based films.

[0053] The surface of the support film on the adhesive side may be subjected to a surface treatment such as application of a primer, corona discharge treatment, plasma treatment, etc. Such a surface treatment can be useful for improving the adhesion between the adhesive side surface and the adhesive (preventing anchor failure).

[0054] In embodiments in which the first film is a release film, the configuration of the release film is not particularly limited. Examples of release films that can be used as the first film include: a release film comprising a resin film as a base film and a release treatment layer provided on at least one surface of the resin film; a release film made of a low-adhesion resin such as a fluorine-based polymer (e.g., polytetrafluoroethylene) or a polyolefin-based resin (e.g., polyethylene, polypropylene); and the like. In some embodiments, a release film comprising a resin film as a base film and a release treatment layer provided on at least one surface of the resin film can be preferably used as the first film. The first film included in the laminate sheet disclosed herein can be the same resin film as the second film included in the laminate sheet, or a resin film that differs only in thickness, and provided with a release treatment layer that is the same as or different from the second film. In embodiments in which the first film is a release film, the maximum height Rz of the release surface (e.g., the surface on which the release treatment layer is formed) of the first film is not particularly limited; for example, the range of the maximum height Rz of the release treatment layer surface of the second film can be adopted.

[0055] Young's modulus (E 120 ) is not particularly limited and may be 500 MPa or less or may be greater than 500 MPa. In some embodiments, the E 120 For example, in a laminate sheet in which the first film is a support film, or in which the first film is a release film and is expected to be thermoformed in a state in which the first film is laminated on the first surface of the pressure-sensitive adhesive body, the E of the first film is preferably 500 MPa or less. 120 The E of the first film is suitably 500 MPa or less, preferably 400 MPa or less, may be 300 MPa or less, may be 200 MPa or less, may be 100 MPa or less, or may be 20 MPa or less. 120 The lower limit is not particularly limited, and may be, for example, 2 MPa or more, 4 MPa or more, 10 MPa or more, 70 MPa or more, 150 MPa or more, 250 MPa or more, or 350 MPa or more.

[0056] Young's modulus (E 85 ) is not particularly limited, and may be 500 MPa or more, or may be less than 500 MPa. In an embodiment in which the first film is a release film including a resin film as a base film and a release treatment layer provided on at least one surface of the resin film, from the viewpoint of preventing poor appearance due to the formation of a release treatment layer on the base film, the E 85 is preferably 500 MPa or more, may be 600 MPa or more, may be 700 MPa or more, may be 900 MPa or more, or may be 1100 MPa or more. 85 There is no particular upper limit to the pressure, and it may be, for example, 2000 MPa or less, 1700 MPa or less, 1500 MPa or less, 1200 MPa or less, or 1000 MPa or less.

[0057] The plastic film used as the base film of the support film or release film in the laminate sheet disclosed herein may be any of an unstretched film, a uniaxially stretched film, and a biaxially stretched film. The plastic film may have a single-layer structure or a multilayer structure (e.g., a three-layer structure) including two or more sublayers. The plastic film may contain known additives that can be used in the support film or release film of a pressure-sensitive adhesive sheet, such as antioxidants, antiaging agents, heat stabilizers, light stabilizers, UV absorbers, colorants such as pigments and dyes, lubricants, fillers, antistatic agents, and nucleating agents. In a multilayer plastic film, each additive may be present in all or only some of the sublayers.

[0058] <Adhesive body> The adhesive body in the laminated sheet disclosed herein may be a substrate-less adhesive body consisting of an adhesive layer made of an adhesive, or may be a substrate-attached adhesive body having adhesive on both sides of a substrate (core material).

[0059] The adhesive surface (second surface) of the adhesive body disclosed herein has a maximum height Rz of approximately 1,000 nm or less. An adhesive body having such a smooth surface can provide a good appearance due to the smoothness, even after being formed into a non-planar shape by heat pressing or the like and then attached to an adherend. The maximum height Rz is preferably approximately 900 nm or less, more preferably approximately 800 nm or less. In some preferred embodiments, the maximum height Rz is approximately 700 nm or less, or may be approximately 600 nm or less, or may be approximately 500 nm or less (e.g., 450 nm or less). Furthermore, from the viewpoint of ease of production and handleability, in some embodiments, the maximum height Rz may be, for example, approximately 10 nm or more, approximately 100 nm or more, approximately 200 nm or more, or approximately 300 nm or more. Having a maximum height Rz equal to or greater than a predetermined value tends to facilitate easier peeling from the release film.

[0060] The maximum height Rz of the adhesive surface of the adhesive body can be adjusted mainly by the surface properties of the release film laminated on the adhesive surface. Specifically, the maximum height Rz of the adhesive surface of the adhesive body is measured by the method described in the Examples below. The specific measurement procedure and measurement conditions can be set according to the measurement conditions described in the Examples below, or to obtain results equivalent to or corresponding to those obtained when the measurement conditions are followed.

[0061] In some embodiments, the adhesive body (typically the adhesive layer) has a stress of 50 N / cm when measured after being stretched 300% at a temperature of 23°C, a pulling rate of 200 mm / min, and being held at the 300% stretched position for 150 seconds. 2 It is preferable that the stress measured under the above conditions corresponds to the residual stress after deformation load. An adhesive body having the above stress (residual stress) below a predetermined value is easy to relax after being molded into a non-planar shape by heat pressing or the like, so that the adhesive body is less likely to be distorted during storage and is easy to maintain a good appearance. The above residual stress is 49 N / cm 2 It may be less than 48N / cm 2 Less than 47N / cm 2 Less than 46N / cm2 Less than 45N / cm 2 In some preferred embodiments, the residual stress is 40 N / cm 2 or less, more preferably 35 N / cm 2 or less, more preferably 30 N / cm 2 The lower limit of the residual stress is not particularly limited, and is usually 1 N / cm from the viewpoint of having a moderate cohesive force and exhibiting good adhesive properties. 2 The above is appropriate, 5N / cm 2 It may be more than 10N / cm 2 More than 15N / cm 2 More than 20N / cm 2 More than 25N / cm 2 More than that is fine.

[0062] The residual stress can be adjusted by the PSA components (e.g., the monomer composition and molecular weight of the base polymer, the polymerization method, the selection of the type and amount of the polyfunctional monomer and crosslinking agent, etc.) The residual stress is specifically measured by the method described in the Examples below.

[0063] The type of adhesive contained in the adhesive body is not particularly limited, and may be one or more adhesives selected from various known adhesives such as acrylic adhesives, rubber adhesives (natural rubber, synthetic rubber, mixtures thereof, etc.), silicone adhesives, polyester adhesives, urethane adhesives, polyether adhesives, polyamide adhesives, and fluorine adhesives. From the viewpoints of transparency, weather resistance, etc., preferred adhesive bodies include those in which the proportion of acrylic adhesives in the adhesive body is 50% by weight or more, more preferably 70% by weight or more, and even more preferably 90% by weight or more. The proportion of acrylic adhesives may be more than 98% by weight, and the adhesive body may be essentially composed of acrylic adhesives.

[0064] In this specification, an acrylic pressure-sensitive adhesive refers to a pressure-sensitive adhesive that uses an acrylic polymer as the base polymer (the main component of the polymer component, i.e., a component that is contained in an amount of more than 50% by weight). The same applies to rubber-based pressure-sensitive adhesives and other pressure-sensitive adhesives. In this specification, "(meth)acrylic" refers to both acrylic and methacrylic in a comprehensive sense. Similarly, "(meth)acryloyl" refers to both acryloyl and methacryloyl in a comprehensive sense, and "(meth)acrylate" refers to both acrylate and methacrylate in a comprehensive sense. In this specification, the term "acrylic polymer" refers to a polymer containing a (meth)acrylic monomer as a monomer component constituting the acrylic polymer. That is, the term refers to a polymer containing a monomer unit derived from a (meth)acrylic monomer. Here, the term "(meth)acrylic monomer" refers to a monomer having at least one (meth)acryloyl group in one molecule.

[0065] Although not particularly limited, in one embodiment of the technology disclosed herein, the pressure-sensitive adhesive body can be suitably prepared using a pressure-sensitive adhesive composition containing a monomer component that constitutes an acrylic polymer. Hereinafter, such a pressure-sensitive adhesive composition may be referred to as an "acrylic pressure-sensitive adhesive composition." Herein, the "monomer component that constitutes the acrylic polymer" refers to the monomer component that constitutes the acrylic polymer in a pressure-sensitive adhesive obtained from the acrylic pressure-sensitive adhesive composition. The monomer component may be contained in the acrylic pressure-sensitive adhesive composition as an unreacted monomer (i.e., in the form of a raw material monomer in which the polymerizable functional group is unreacted), in the form of a polymer (i.e., as a monomer unit), or in both of these forms.

[0066] In one embodiment of the technology disclosed herein, the above-mentioned adhesive body can be formed using a pressure-sensitive adhesive composition containing the following component (A) as a monomer component constituting the acrylic polymer. In a preferred embodiment, the above-mentioned adhesive body can be suitably formed using an acrylic pressure-sensitive adhesive composition containing at least the following component (A) as a monomer component constituting the acrylic polymer, and further containing the following component (B) and / or the following component (C) as necessary.

[0067] (Component (A)) The component (A) is an alkyl(meth)acrylate having an alkyl group having 2 to 18 carbon atoms at the ester terminal. Hereinafter, an alkyl(meth)acrylate having an alkyl group having a carbon number of X or more and Y or less at the ester terminal will be referred to as "C X-Y It is sometimes written as "alkyl (meth)acrylate". 2-18 C in alkyl (meth)acrylate 2-18 The structure of the alkyl group is not particularly limited, and both straight-chain and branched-chain alkyl groups can be used. 2-18 The alkyl (meth)acrylates can be used alone or in combination of two or more.

[0068] C with a straight chain alkyl group at the ester end 2-18 Examples of alkyl (meth)acrylates include ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-undecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, n-pentadecyl (meth)acrylate, n-hexadecyl (meth)acrylate, n-heptadecyl (meth)acrylate, and n-octadecyl (meth)acrylate. Also, C alkyl groups having a branched alkyl group at the ester terminal are available.3-18 Examples of alkyl (meth)acrylates include isopropyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, isopentyl (meth)acrylate, t-pentyl (meth)acrylate, neopentyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, 2-propylheptyl (meth)acrylate, isoundecyl (meth)acrylate, isododecyl (meth)acrylate, isotridecyl (meth)acrylate, isomistyryl (meth)acrylate, isopentadecyl (meth)acrylate, isohexadecyl (meth)acrylate, isoheptadecyl (meth)acrylate, and isostearyl (meth)acrylate. The technology disclosed herein is a method for producing a cellulose acetate composition comprising the steps of: (A) component C 4-9 It is preferable to use one or more alkyl acrylates selected from the group consisting of C, ... 4-9 Suitable examples of alkyl acrylates include n-butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate and isononyl acrylate.

[0069] ((B) component) The component (B) is a monomer selected from the group consisting of alicyclic monomers and heterocycle-containing monomers. This component (B) is typically used in combination with the component (A), and can be useful for improving the cohesion, transparency, heat resistance, etc. of the PSA.

[0070] Alicyclic monomers can be used without particular limitations as long as they have a polymerizable functional group with an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, and an alicyclic structure-containing group. Alicyclic monomers can be used singly or in combination of two or more. Here, the term "alicyclic structure-containing group" refers to a moiety containing at least one alicyclic structure. Furthermore, the term "alicyclic structure" refers to a saturated or unsaturated carbon ring structure that does not have aromaticity. In this specification, the alicyclic structure-containing group may be simply referred to as an "alicyclic group." Suitable examples of the alicyclic group include hydrocarbon groups and hydrocarbonoxy groups that contain an alicyclic structure.

[0071] In the technology disclosed herein, preferred examples of alicyclic monomers include alicyclic (meth)acrylates having an alicyclic group and a (meth)acryloyl group. Specific examples of alicyclic (meth)acrylates include cyclopropyl (meth)acrylate, cyclobutyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, cyclooctyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and the like, as well as HPMPA, TMA-2, HCPA, and the like, as shown in the following chemical formula.

[0072] [ka]

[0073] The number of carbon atoms in the alicyclic group in the alicyclic monomer (in the case of an alicyclic (meth)acrylate, the portion obtained by removing the (meth)acryloyl group from the alicyclic (meth)acrylate) is not particularly limited. For example, an alicyclic monomer having an alicyclic group with 4 to 24 carbon atoms (preferably 5 to 18, more preferably 5 to 12) can be used. Among these, cyclohexyl acrylate (CHA), cyclohexyl methacrylate, isobornyl acrylate (IBXA), and isobornyl methacrylate are preferred, CHA and IBXA are more preferred, and CHA is particularly preferred.

[0074] Examples of heterocycle-containing monomers include cyclic nitrogen-containing monomers and cyclic ether group-containing monomers. Like alicyclic monomers, heterocycle-containing monomers can be useful for improving the cohesiveness, transparency, and heat resistance of the pressure-sensitive adhesive. They can also be useful for improving the adhesive strength and cohesive strength of the pressure-sensitive adhesive. One type of heterocycle-containing monomer can be used alone, or two or more types can be used in combination.

[0075] The cyclic nitrogen-containing monomer may be any monomer having a polymerizable functional group with an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, and a cyclic nitrogen structure. The cyclic nitrogen structure preferably has a nitrogen atom within the cyclic structure. Examples of the cyclic nitrogen-containing monomer include lactam vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and methylvinylpyrrolidone; oxazoline group-containing monomers such as 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, and 2-isopropenyl-2-oxazoline; and vinyl monomers having a nitrogen-containing heterocycle, such as vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, and vinylmorpholine. Other examples of the cyclic nitrogen-containing monomer include (meth)acrylic monomers having a nitrogen-containing heterocycle, such as a morpholine ring, a piperidine ring, a pyrrolidine ring, a piperazine ring, and an aziridine ring. Specific examples include N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylpyrrolidine, N-acryloylaziridine, etc. Among the above cyclic nitrogen-containing monomers, lactam vinyl monomers are preferred from the viewpoint of aggregation properties, etc., and N-vinylpyrrolidone is more preferred.

[0076] Monomers having a cyclic ether group can be any monomer having a polymerizable functional group with an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, and a cyclic ether group, such as an epoxy group or an oxetane group, without any particular limitation. Examples of epoxy group-containing monomers include glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate glycidyl ether. Examples of oxetane group-containing monomers include 3-oxetanylmethyl (meth)acrylate, 3-methyl-oxetanylmethyl (meth)acrylate, 3-ethyl-oxetanylmethyl (meth)acrylate, 3-butyl-oxetanylmethyl (meth)acrylate, and 3-hexyl-oxetanylmethyl (meth)acrylate.

[0077] ((C) component) The component (C) is a monomer having at least one of a hydroxy group and a carboxy group.

[0078] The hydroxyl group-containing monomer may be any monomer having a polymerizable functional group with an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, and a hydroxyl group. The hydroxyl group-containing monomer may be used alone or in combination of two or more. Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate; hydroxyalkyl cycloalkane (meth)acrylates such as (4-hydroxymethylcyclohexyl)methyl (meth)acrylate; and others such as hydroxyethyl (meth)acrylamide, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether. Among these, hydroxyalkyl (meth)acrylates are preferred. For example, hydroxyalkyl (meth)acrylates having a hydroxyalkyl group having 2 to 6 carbon atoms at the ester terminal are preferred. In a preferred embodiment, one or more hydroxy group-containing monomers selected from 2-hydroxyethyl acrylate (HEA), 2-hydroxyethyl methacrylate, 4-hydroxybutyl acrylate (4HBA), and 4-hydroxybutyl methacrylate can be used. In a preferred embodiment of the technology disclosed herein, the hydroxy group-containing monomer used may be 4HBA alone, HEA alone, or a combination of 4HBA and HEA.

[0079] The carboxyl group-containing monomer may be any monomer having a polymerizable functional group with an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, and a carboxyl group, without any particular limitations. The carboxyl group-containing monomer may be used alone or in combination of two or more. Examples of the carboxyl group-containing monomer include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, carboxyethyl (meth)acrylate, and carboxypentyl (meth)acrylate; ethylenically unsaturated dicarboxylic acids such as itaconic acid, maleic acid, fumaric acid, and citraconic acid; metal salts thereof (e.g., alkali metal salts); and anhydrides of the above ethylenically unsaturated dicarboxylic acids, such as maleic anhydride and itaconic anhydride. Among these, acrylic acid and methacrylic acid are preferred, with acrylic acid being particularly preferred.

[0080] The technology disclosed herein can be preferably implemented in an embodiment in which component (C) contains a hydroxy group-containing monomer. That is, component (C) preferably contains only a hydroxy group-containing monomer, or contains both a hydroxy group-containing monomer and a carboxy group-containing monomer. When component (C) contains both a hydroxy group-containing monomer and a carboxy group-containing monomer, the proportion of the hydroxy group-containing monomer in the entire component (C) is preferably greater than approximately 50% by weight, more preferably approximately 80% by weight or more (e.g., approximately 90% by weight or more). Increasing the proportion of the hydroxy group-containing monomer in component (C) is preferable from the perspective of reducing metal corrosion caused by carboxy groups, etc. The technology disclosed herein can be preferably implemented in an embodiment in which the monomer component substantially does not contain a carboxy group-containing monomer. For example, the proportion of the carboxy group-containing monomer in the monomer component can be less than approximately 1% by weight, preferably less than approximately 0.5% by weight, and more preferably less than approximately 0.2% by weight.

[0081] The proportion of the (A) component in the total monomer components is not particularly limited. From the viewpoint of imparting appropriate cohesiveness to the PSA, the proportion of the (A) component is typically approximately 90% by weight or less, preferably approximately 85% by weight or less, and more preferably approximately 75% by weight or less. In a preferred embodiment, the proportion of the (A) component may be approximately 70% by weight or less (more preferably approximately 60% by weight or less, even more preferably approximately 50% by weight or less, for example, approximately 45% by weight or less). Furthermore, from the viewpoint of initial adhesion to an adherend, the proportion of the (A) component is preferably approximately 30% by weight or more, more preferably approximately 35% by weight or more. In one embodiment, the proportion of the (A) component in the total monomer components can be, for example, about 30 to 75% by weight.

[0082] When the monomer components include component (B), the proportion of component (B) relative to the total monomer components is not particularly limited. Considering the balance of adhesive properties, the proportion of component (B) is typically approximately 3% by weight or more, preferably approximately 5% by weight or more, more preferably approximately 8% by weight or more, and may be approximately 10% by weight or more. Furthermore, from the viewpoint of initial adhesion to the adherend, the proportion of component (B) is approximately 65% ​​by weight or less, preferably approximately 60% by weight or less, and more preferably approximately 55% by weight or less (even approximately 50% by weight or less, e.g., less than approximately 50% by weight). In a preferred embodiment, the proportion of component (B) relative to the total monomer components may be approximately 15% by weight or more, approximately 20% by weight or more, approximately 25% by weight or more, or even approximately 30% by weight or more (e.g., approximately 35% by weight or more). In one embodiment, the proportion of component (B) relative to the total monomer components may be, for example, approximately 20 to 50% by weight.

[0083] When the monomer components include component (C), the proportion of component (C) in the total monomer components is not particularly limited. From the viewpoint of initial adhesion to an adherend, the proportion of component (C) is typically about 3 wt % or more, preferably about 5 wt % or more, and more preferably about 8 wt % or more (e.g., about 10 wt % or more). Furthermore, from the viewpoint of imparting appropriate cohesive properties to the PSA, the proportion of component (C) is usually preferably about 35 wt % or less, more preferably about 30 wt % or less, and even more preferably about 25 wt % or less. In one embodiment, the proportion of component (C) can be, for example, about 15 to 30 wt %.

[0084] (Optional Monomer) The monomer components constituting the acrylic polymer may contain, as necessary, a monomer other than the above-mentioned components (A), (B), and (C) (hereinafter also referred to as "optional monomer").

[0085] Examples of the optional monomer include alkyl(meth)acrylates not belonging to component (A), i.e., alkyl(meth)acrylates in which the alkyl group has 1 or 19 or more carbon atoms (for example, 19 to 24). Specific examples of such alkyl(meth)acrylates include methyl(meth)acrylate, n-nonadecyl(meth)acrylate, isononadecyl(meth)acrylate, n-eicosyl(meth)acrylate, isoeicosyl(meth)acrylate, etc. These can be used alone or in combination of two or more.

[0086] Other examples of the optional monomer include monomers containing functional groups other than hydroxyl and carboxyl groups. Such functional group-containing monomers can be used to introduce crosslinking points into the acrylic polymer or to increase the cohesive strength of the acrylic polymer. Examples of functional group-containing monomers include amide group-containing monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, and N-methylol(meth)acrylamide; cyano group-containing monomers such as acrylonitrile and methacrylonitrile; sulfonic acid group-containing monomers such as styrenesulfonic acid, allylsulfonic acid, and 2-(meth)acrylamido-2-methylpropanesulfonic acid; phosphate group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; keto group-containing monomers such as diacetone(meth)acrylamide, diacetone(meth)acrylate, vinyl methyl ketone, and vinyl acetoacetate; isocyanate group-containing monomers such as 2-(meth)acryloyloxyethyl isocyanate; alkoxy group-containing monomers such as methoxyethyl(meth)acrylate and ethoxyethyl(meth)acrylate; and alkoxysilyl group-containing monomers such as 3-(meth)acryloxypropyltrimethoxysilane and 3-(meth)acryloxypropyltriethoxysilane. These can be used alone or in combination of two or more.

[0087] The monomer components in the technology disclosed herein may contain, as the optional monomer, a copolymerizable monomer other than those exemplified above that is copolymerizable with the components (A), (B), and (C) for the purposes of adjusting the glass transition temperature (Tg) of the acrylic polymer or improving the cohesive strength, for example. Examples of such copolymerizable monomers include vinyl carboxylate esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene, substituted styrenes (α-methylstyrene, etc.), and vinyltoluene; aromatic ring-containing (meth)acrylates such as aryl(meth)acrylates (e.g., phenyl(meth)acrylate), aryloxyalkyl(meth)acrylates (e.g., phenoxyethyl(meth)acrylate), and arylalkyl(meth)acrylates (e.g., benzyl(meth)acrylate); olefinic monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene; chlorine-containing monomers such as vinyl chloride and vinylidene chloride; vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether; and macromonomers having a radically polymerizable vinyl group at the terminal of a monomer obtained by polymerizing a vinyl group. These may be used alone or in combination of two or more.

[0088] The amount of these optional monomers used is not particularly limited and can be determined appropriately. Typically, the total amount of optional monomers used is suitably less than approximately 50% by weight of the monomer components, preferably approximately 30% by weight or less, and more preferably approximately 20% by weight or less. The technology disclosed herein can be preferably implemented in an embodiment in which the total amount of optional monomers used is approximately 10% by weight or less (e.g., approximately 5% by weight or less) of the monomer components. When optional monomers are used, in order to adequately exert the effect of enhancing adhesive strength and cohesive strength, the amount of the optional monomers used is suitably approximately 0.5% by weight or more of the monomer components, preferably approximately 0.8% by weight or more. The technology disclosed herein can also be preferably implemented in an embodiment in which no optional monomers are substantially used (e.g., an embodiment in which the amount of optional monomers used is approximately 0.3% by weight or less, typically approximately 0.1% by weight or less, of the monomer components).

[0089] The above-mentioned components (A), (B), (C), and optional monomers are typically monofunctional monomers. In addition to such monofunctional monomers, the above-mentioned monomer components may contain an appropriate amount of polyfunctional monomers as needed for purposes such as adjusting the storage modulus of the PSA. Herein, the term "monofunctional monomer" refers to a monomer having only one polymerizable functional group (typically a radically polymerizable functional group) with an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group. In contrast, the term "polyfunctional monomer" refers to a monomer having at least two such polymerizable functional groups, as described below.

[0090] (polyfunctional monomer) The polyfunctional monomer is a monomer having at least two polymerizable functional groups (typically radically polymerizable functional groups) having an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group. Examples of polyfunctional monomers include esters of polyhydric alcohols and (meth)acrylic acid, such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tetramethylolmethane tri(meth)acrylate; allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, and urethane acrylate. Among these, preferred examples include trimethylolpropane tri(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. Of these, preferred examples include 1,6-hexanediol diacrylate (HDDA). The polyfunctional monomers can be used alone or in combination of two or more. From the viewpoint of reactivity, etc., polyfunctional monomers having two or more acryloyl groups are usually preferred.

[0091] The amount of polyfunctional monomer used is not particularly limited and can be appropriately set so as to achieve the intended purpose of the polyfunctional monomer. In some embodiments, the amount of polyfunctional monomer used can be approximately 3% by weight or less of the monomer components, preferably approximately 2% by weight or less, and more preferably approximately 1% by weight or less. In some preferred embodiments, the amount of polyfunctional monomer used is less than 1% by weight of the monomer components, and may be less than 0.8% by weight, less than 0.6% by weight, less than 0.5% by weight, or less than 0.4% by weight. By limiting the amount of polyfunctional monomer used within the above range, the residual stress of the PSA after molding tends to decrease. When a polyfunctional monomer is used, the lower limit of the amount used is not particularly limited as long as it is greater than 0% by weight. Usually, the amount of polyfunctional monomer used is approximately 0.001% by weight or more (e.g., approximately 0.01% by weight or more) of the monomer components, and may be 0.05% by weight or more, or may be 0.1% by weight or more.

[0092] Although not particularly limited, the proportion of the total amount of components (A), (B), and (C) relative to the total monomer components is typically greater than approximately 50% by weight, preferably approximately 70% by weight or more, more preferably approximately 80% by weight or more, and even more preferably approximately 90% by weight or more. The technology disclosed herein is preferably implemented in an embodiment in which the proportion of the total amount is approximately 95% by weight or more (e.g., approximately 99% by weight or more). The proportion of the total amount may be 100% by weight. The technology disclosed herein is preferably implemented in an embodiment in which the proportion of the total amount relative to the total monomer components is 99.999% by weight or less (e.g., 99.99% by weight or less).

[0093] The Tg of the copolymer corresponding to the composition of the monomer components is not particularly limited and may be, for example, approximately −70°C or higher. In some embodiments, the Tg of the copolymer may be, for example, approximately −60°C or higher, preferably approximately −55°C or higher, more preferably approximately −50°C or higher, and may be approximately −45°C or higher. The technology disclosed herein can also be preferably implemented in an embodiment in which the Tg of the copolymer is approximately −40°C or higher (e.g., approximately −35°C or higher), or even approximately −30°C or higher. The Tg of the copolymer is usually appropriately approximately 0°C or lower, and is preferably approximately −10°C or lower from the viewpoint of the adhesiveness of the pressure-sensitive adhesive to the adherend and the low-temperature properties. In some embodiments, the Tg of the copolymer may be approximately −15°C or lower, or may be approximately −20°C or lower. The technology disclosed herein can also be preferably implemented in an embodiment in which the Tg of the copolymer is approximately −30°C or higher and approximately −10°C or lower.

[0094] Here, the Tg of a copolymer corresponding to the composition of the monomer components refers to the Tg calculated based on the composition of the monomer components using the Fox equation, which is a relational expression between the Tg of a copolymer and the glass transition temperature Tgi of a homopolymer obtained by homopolymerizing each of the monomers constituting the copolymer, as shown below. 1 / Tg=Σ(Wi / Tgi) In the Fox formula, Tg represents the glass transition temperature (unit: K) of the copolymer, Wi represents the weight fraction of monomer i in the copolymer (copolymerization ratio by weight), and Tgi represents the glass transition temperature (unit: K) of the homopolymer of monomer i. However, in this specification, Tg is calculated taking into account only monofunctional monomers. Therefore, when the monomer component contains polyfunctional monomers, the total amount of monofunctional monomers contained in the monomer component is set to 100% by weight, and Tg is calculated based on the Tg of the homopolymer of each monofunctional monomer and the weight fraction of the monofunctional monomer relative to the total amount.

[0095] The glass transition temperature of the homopolymer used to calculate Tg is determined based on the value described in the publicly available literature. For example, for the following monomers, the following values ​​are used as the glass transition temperatures of the homopolymers of the monomers: n-Butyl acrylate -55℃ 2-Ethylhexyl acrylate -70℃ Cyclohexyl acrylate 15℃ Isobornyl acrylate 94℃ 2-Hydroxyethyl acrylate -15℃ 4-Hydroxybutyl acrylate -40℃ N-vinylpyrrolidone 54℃ Acrylic acid 106℃ Methacrylic acid 228℃

[0096] For the glass transition temperatures of homopolymers of monomers other than those exemplified above, the values ​​described in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) shall be used. For monomers for which multiple values ​​are described in the above literature, the highest value shall be used. If the glass transition temperature of the homopolymer is not described in publicly available materials, the value obtained by the measurement method described in JP 2007-51271 A shall be used. For monomers for which the manufacturer or other source provides a nominal value for the glass transition temperature of the homopolymer, that nominal value may be used.

[0097] (Adhesive composition) The adhesive body in the technology disclosed herein can be formed using a pressure-sensitive adhesive composition containing the monomer components having the above-mentioned composition in the form of a polymer, an unpolymer (i.e., a form in which the polymerizable functional group is unreacted), or a mixture thereof. The pressure-sensitive adhesive composition can be in various forms, such as a composition containing a pressure-sensitive adhesive (adhesive component) in an organic solvent (solvent-based pressure-sensitive adhesive composition), a composition in which a pressure-sensitive adhesive is dispersed in an aqueous solvent (water-dispersed pressure-sensitive adhesive composition), a composition prepared to form a pressure-sensitive adhesive upon curing with active energy rays such as ultraviolet light or radiation (active energy ray-curable pressure-sensitive adhesive composition), or a hot-melt pressure-sensitive adhesive composition that is applied in a heated and molten state and forms a pressure-sensitive adhesive upon cooling to around room temperature.

[0098] Here, in this specification, the term "active energy rays" refers to energy rays having energy capable of inducing chemical reactions such as polymerization reactions, crosslinking reactions, decomposition of initiators, etc. Examples of active energy rays referred to here include light such as ultraviolet rays, visible light, and infrared rays, and radioactive rays such as α rays, β rays, γ rays, electron beams, neutron beams, and X-rays.

[0099] The pressure-sensitive adhesive composition typically contains at least a portion of the monomer components of the composition (which may be a portion of the type of monomer or a portion of the amount) in the form of a polymer. The polymerization method used to form the polymer is not particularly limited, and various conventionally known polymerization methods can be appropriately employed. Examples of suitable polymerization methods include thermal polymerization (typically carried out in the presence of a thermal polymerization initiator), such as solution polymerization, emulsion polymerization, and bulk polymerization; photopolymerization (typically carried out in the presence of a photopolymerization initiator) carried out by irradiation with light such as ultraviolet light; and radiation polymerization (typically carried out by irradiation with radiation such as beta rays and gamma rays). Among these, photopolymerization is preferred. The polymerization mode in these polymerization methods is not particularly limited, and can be carried out by appropriately selecting a conventionally known method for supplying monomers, polymerization conditions (temperature, time, pressure, light exposure dose, radiation exposure dose, etc.), and materials used other than the monomers (polymerization initiator, surfactant, etc.).

[0100] In the polymerization, a known or commonly used photopolymerization initiator or thermal polymerization initiator can be used depending on the polymerization method, polymerization mode, etc. Such polymerization initiators can be used alone or in appropriate combination of two or more.

[0101] The photopolymerization initiator is not particularly limited, but examples of usable photopolymerization initiators include ketal-based photopolymerization initiators, acetophenone-based photopolymerization initiators, benzoin ether-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, and thioxanthone-based photopolymerization initiators.

[0102] The thermal polymerization initiator is not particularly limited, but examples thereof include azo polymerization initiators, peroxide initiators, redox initiators formed by combining peroxides with reducing agents, substituted ethane initiators, etc. Thermal polymerization is preferably carried out at a temperature of, for example, about 20 to 100°C (typically 40 to 80°C).

[0103] The amount of such a thermal polymerization initiator or photopolymerization initiator used is not particularly limited and may be a normal amount depending on the polymerization method, polymerization mode, etc. For example, about 0.001 to 5 parts by weight (typically about 0.01 to 2 parts by weight, for example, about 0.01 to 1 part by weight) of the polymerization initiator can be used per 100 parts by weight of the monomer to be polymerized.

[0104] (Adhesive composition containing polymerized and unpolymerized monomer components) A preferred embodiment of the pressure-sensitive adhesive composition comprises a polymerization reaction product of a monomer mixture containing at least a portion of the monomer components (raw material monomers) of the composition. Typically, the composition contains a portion of the monomer components in the form of a polymer, and the remainder in the form of an unpolymerized product (unreacted monomer). A pressure-sensitive adhesive composition containing a polymer and an unpolymerized product of the monomer components can be preferably used, for example, as an active energy ray-curable pressure-sensitive adhesive composition. The polymerization reaction product of the monomer mixture can be prepared by at least partially polymerizing the monomer mixture. The polymerization reaction product is preferably a partial polymer of the monomer mixture. Such a partial polymer is a mixture of polymers derived from the monomer mixture and unreacted monomers, and typically has a syrup-like appearance (a viscous liquid). Hereinafter, a partial polymer in this state may be referred to as a "monomer syrup" or simply as a "syrup."

[0105] The polymerization method for obtaining the polymerization reaction product is not particularly limited, and various polymerization methods such as those described above can be appropriately selected and used. From the viewpoints of efficiency and simplicity, a photopolymerization method can be preferably used. Photopolymerization makes it possible to easily control the polymerization conversion rate of the monomer mixture by adjusting polymerization conditions such as the amount of light irradiation (light amount).

[0106] The polymerization conversion rate (monomer conversion) of the monomer mixture in the partially polymerized product is not particularly limited. The polymerization conversion rate can be, for example, about 70% by weight or less, and preferably about 60% by weight or less. From the viewpoint of ease of preparation and coatability of the pressure-sensitive adhesive composition containing the partially polymerized product, the polymerization conversion rate is usually suitably about 50% by weight or less, and preferably about 40% by weight or less (e.g., about 35% by weight or less). There is no particular lower limit to the polymerization conversion rate, but it is typically about 1% by weight or more, and usually about 5% by weight or more.

[0107] The pressure-sensitive adhesive composition containing the partial polymer of the monomer mixture can be easily obtained, for example, by partially polymerizing a monomer mixture containing all of the raw material monomers by an appropriate polymerization method (e.g., photopolymerization). Other components (e.g., photopolymerization initiators, polyfunctional monomers, crosslinking agents, etc.) may be blended into the pressure-sensitive adhesive composition containing the partial polymer, as needed. The method for blending such other components is not particularly limited; for example, they may be incorporated into the monomer mixture in advance, or they may be added to the partial polymer.

[0108] The PSA composition disclosed herein may also be in a form in which a partially polymerized or fully polymerized product of a monomer mixture containing some types of monomers among the monomer components (raw material monomers) is dissolved in the remaining types of monomers or their partially polymerized products. PSA compositions in such a form are also included in examples of PSA compositions containing polymerized and unpolymerized products of the monomer components. In this specification, the term "fully polymerized product" refers to a product having a polymerization conversion rate of more than 95% by weight.

[0109] Photopolymerization is preferably used as a curing method (polymerization method) when forming a pressure-sensitive adhesive from a pressure-sensitive adhesive composition containing a polymerized and unpolymerized monomer component. Photopolymerization is particularly suitable as a curing method for a pressure-sensitive adhesive composition containing a polymerization reactant prepared by photopolymerization. Since the polymerization reactant obtained by photopolymerization already contains a photopolymerization initiator, when the pressure-sensitive adhesive composition containing this polymerization reactant is further cured to form a pressure-sensitive adhesive, photocuring can be achieved without adding a new photopolymerization initiator. Alternatively, the pressure-sensitive adhesive composition may be prepared by adding a photopolymerization initiator to the polymerization reactant prepared by photopolymerization as needed. The added photopolymerization initiator may be the same as or different from the photopolymerization initiator used to prepare the polymerization reactant. Pressure-sensitive adhesive compositions prepared by methods other than photopolymerization can be made photocurable by adding a photopolymerization initiator. Photocurable pressure-sensitive adhesive compositions have the advantage of being easily formed, even in thick pressure-sensitive adhesive layers. In a preferred embodiment, photopolymerization when forming a pressure-sensitive adhesive from the pressure-sensitive adhesive composition can be performed by ultraviolet irradiation. For ultraviolet irradiation, known high pressure mercury lamps, low pressure mercury lamps, metal halide lamps, etc. can be used.

[0110] (Adhesive composition containing monomer component in the form of a completely polymerized product) A PSA composition according to another preferred embodiment contains the monomer components of the PSA composition in the form of a complete polymer, and may be in the form of, for example, a solvent-based PSA composition containing an acrylic polymer, which is a complete polymer of the monomer components, in an organic solvent, or an aqueous-dispersion PSA composition in which the acrylic polymer is dispersed in an aqueous solvent.

[0111] (Crosslinking agent) The pressure-sensitive adhesive composition disclosed herein may contain a crosslinking agent. Examples of crosslinking agents that can be used include those known or commonly used in the field of pressure-sensitive adhesives. Examples include epoxy-based crosslinking agents, isocyanate-based crosslinking agents, silicone-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, silane-based crosslinking agents, alkyl-etherified melamine-based crosslinking agents, and metal chelate-based crosslinking agents. These crosslinking agents can be used alone or in combination of two or more. The content of the crosslinking agent (the total amount when two or more crosslinking agents are included) is not particularly limited. From the viewpoint of realizing a pressure-sensitive adhesive that exhibits well-balanced adhesive properties such as adhesive strength and cohesive strength, the content of the crosslinking agent is usually about 5 parts by weight or less, preferably about 0.001 to 5 parts by weight, more preferably about 0.001 to 4 parts by weight, and even more preferably about 0.001 to 3 parts by weight, per 100 parts by weight of the monomer components included in the pressure-sensitive adhesive composition. Alternatively, the pressure-sensitive adhesive composition may not contain the above-mentioned crosslinking agent.

[0112] (oligomer) The pressure-sensitive adhesive composition disclosed herein may contain an oligomer (e.g., an acrylic oligomer) from the viewpoint of improving adhesive strength. As the acrylic oligomer, it is preferable to use a polymer having a Tg higher than that of a copolymer corresponding to the composition of the above-mentioned monomer components (typically, this roughly corresponds to the Tg of the acrylic polymer contained in the pressure-sensitive adhesive formed from the pressure-sensitive adhesive composition). By containing an oligomer, the adhesive strength of the pressure-sensitive adhesive can be improved.

[0113] The oligomer (e.g., acrylic oligomer) desirably has a Tg of about 0°C or higher and about 300°C or lower, preferably about 20°C or higher and about 300°C or lower, and more preferably about 40°C or higher and about 300°C or lower. Having a Tg within the above range allows for an appropriate improvement in adhesive strength. The Tg of the oligomer, like the Tg of the copolymer corresponding to the composition of the above monomer components, is a value calculated based on the Fox formula.

[0114] The weight-average molecular weight (Mw) of the oligomer (e.g., acrylic oligomer) is typically about 1,000 or more but less than about 30,000, preferably about 1,500 or more but less than about 20,000, and more preferably about 2,000 or more but less than about 10,000. Having an Mw within the above range is preferable because it provides good adhesive strength and retention properties. The Mw of the oligomer can be measured by gel permeation chromatography (GPC) and calculated as a value equivalent to standard polystyrene. Specifically, it is measured using a Tosoh Corporation HPLC 8020 with two TSKgel GMH-H (20) columns at a flow rate of about 0.5 ml / min in tetrahydrofuran solvent.

[0115] Examples of monomers constituting the oligomer (specifically, acrylic oligomer) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl ( Examples of the (meth)acrylate include alkyl (meth)acrylates such as cyclohexyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate; esters of (meth)acrylic acid and alicyclic alcohols such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; aryl (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate; and (meth)acrylates obtained from alcohols derived from terpene compounds. These (meth)acrylates can be used alone or in combination of two or more.

[0116] The acrylic oligomer preferably contains, as a monomer unit, an acrylic monomer having a relatively bulky structure, such as alkyl (meth)acrylates having a branched alkyl group, such as isobutyl (meth)acrylate and t-butyl (meth)acrylate; esters of (meth)acrylic acid and alicyclic alcohol, such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; (meth)acrylates having a cyclic structure, such as aryl (meth)acrylates, such as phenyl (meth)acrylate and benzyl (meth)acrylate; etc., from the viewpoint of further improving the adhesiveness of the pressure-sensitive adhesive layer. Furthermore, when ultraviolet light is used during the synthesis of the acrylic oligomer or during the preparation of the pressure-sensitive adhesive layer, those having saturated bonds are preferred, since they are less likely to cause polymerization inhibition. Alkyl (meth)acrylates having a branched alkyl group, or esters of alicyclic alcohols, can be suitably used as the monomer constituting the acrylic oligomer.

[0117] From this viewpoint, suitable acrylic oligomers include, for example, homopolymers of dicyclopentanyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate (IBXA), dicyclopentanyl acrylate (DCPA), 1-adamantyl methacrylate (ADMA), and 1-adamantyl acrylate (ADA), as well as copolymers of CHMA and isobutyl methacrylate (IBMA), copolymers of CHMA and IBXMA, copolymers of CHMA and acryloylmorpholine (ACMO), copolymers of CHMA and diethylacrylamide (DEAA), copolymers of ADA and methyl methacrylate (MMA), copolymers of DCPMA and IBXMA, and copolymers of DCPMA and MMA.

[0118] When the pressure-sensitive adhesive composition disclosed herein contains an oligomer (e.g., an acrylic oligomer), the content thereof is not particularly limited. From the viewpoint of effectively exhibiting the effect of adding the oligomer, the content of the oligomer is preferably about 1 part by weight or more, more preferably about 3 parts by weight or more, and may be about 5 parts by weight or more, per 100 parts by weight of the monomer components contained in the pressure-sensitive adhesive composition. Furthermore, from the viewpoint of easily realizing a pressure-sensitive adhesive layer having a desirable storage modulus, the content of the oligomer is usually preferably about 20 parts by weight or less, more preferably about 15 parts by weight or less, and even more preferably about 10 parts by weight or less, per 100 parts by weight of the monomer components contained in the pressure-sensitive adhesive composition. Furthermore, the technology disclosed herein can also be practiced in an embodiment in which an oligomer (e.g., an acrylic oligomer) is not used.

[0119] In addition, the PSA composition disclosed herein may contain various additives known in the field of PSA, as needed. For example, colorants such as dyes and pigments, antistatic agents, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, antiaging agents, light stabilizers, UV absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particulate materials, foil-like materials, etc. may be added as appropriate depending on the application.

[0120] In the technology disclosed herein, an active energy ray-curable pressure-sensitive adhesive composition (typically a photocurable pressure-sensitive adhesive composition) can be preferably used as the pressure-sensitive adhesive composition used to form the pressure-sensitive adhesive body. From the viewpoint of environmental hygiene, etc., a solvent-free pressure-sensitive adhesive composition is preferred. Herein, a solvent-free pressure-sensitive adhesive composition refers to a pressure-sensitive adhesive composition that is substantially free of solvent. For example, a solvent-free pressure-sensitive adhesive composition having a solvent content of about 5 wt % or less (more preferably about 3 wt % or less, e.g., about 0.5 wt % or less) is preferred. The solvent refers to a volatile component that should be removed during the pressure-sensitive adhesive body formation process, i.e., a volatile component that is not intended to be a constituent of the pressure-sensitive adhesive body that is ultimately formed.

[0121] (substrate-less adhesive) In some preferred embodiments, the adhesive body is a substrateless adhesive body comprising an adhesive layer formed of an adhesive. Generally, substrateless adhesive bodies exhibit higher deformability and flexibility than substrate-attached adhesive bodies having adhesives on both sides of a substrate (core material). For this reason, a laminate sheet having a substrateless adhesive body is advantageous from the viewpoint of the thermoformability of the laminate sheet and is also preferred from the viewpoint of the adhesion of the adhesive body to the surface of an adherend. The laminate sheet disclosed herein may be in a form in which a first surface of the substrateless adhesive body is fixed to a non-releasable support film (first film), and the second film (release film) is laminated on the second surface of the substrateless adhesive body, or in a form in which a first film, which is a release film, is laminated on the first surface of the substrateless adhesive body, and the second film (release film) is laminated on the second surface of the substrateless adhesive body.

[0122] The thickness of the pressure-sensitive adhesive layer constituting the substrate-less pressure-sensitive adhesive body is not particularly limited. The thickness of the pressure-sensitive adhesive layer may be, for example, about 1 μm to 1000 μm, and is suitably about 5 μm to 250 μm. In some embodiments, the thickness of the pressure-sensitive adhesive layer may be, for example, 10 μm or more, preferably 20 μm or more, more preferably 25 μm or more, and may be greater than 25 μm, 30 μm or more, 35 μm or more, 40 μm or more, or 45 μm or more. As the thickness of the pressure-sensitive adhesive layer increases, the stress dispersion ability of the pressure-sensitive adhesive layer tends to increase. This is advantageous from the viewpoint of preventing the release film from partially lifting from the surface of the pressure-sensitive adhesive layer during thermoforming or over time thereafter. On the other hand, if the thickness of the pressure-sensitive adhesive layer is excessively large, problems may occur due to the pressure-sensitive adhesive protruding from the outer edges of the laminate sheet when the laminate sheet is subjected to processing such as thermoforming or cutting. Therefore, in some embodiments, the thickness of the pressure-sensitive adhesive layer is suitably, for example, 200 μm or less, and may be 150 μm or less, 100 μm or less, or 70 μm or less.

[0123] (Adhesive body with substrate) The laminate sheet disclosed herein may be in the form of a substrate-attached adhesive body having adhesives on both sides of a substrate (core material). Such a substrate-attached adhesive body can be produced, for example, by a method of forming an adhesive by curing (drying, crosslinking, reacting, etc.) an adhesive composition directly applied to the substrate, or by a method of laminating an adhesive formed on a release surface (which may be the release surface of the second film or the first film) to the substrate, or a combination of these methods.

[0124] The substrate in the substrate-attached adhesive body is not particularly limited, and examples thereof include resin films, paper, cloth, metal foils, and composites thereof. Examples of resin films include the various plastic films exemplified as the base film of the first film or the second film. Examples of paper include Japanese paper, kraft paper, glassine paper, fine paper, synthetic paper, and top-coated paper. Examples of cloth include woven fabrics and nonwoven fabrics made by spinning various fibrous materials alone or in combination. Examples of the fibrous materials include cotton, staple fiber, Manila hemp, pulp, rayon, acetate fiber, polyester fiber, polyvinyl alcohol fiber, polyamide fiber, and polyolefin fiber. Examples of metal foils include aluminum foil and copper foil. From the viewpoint of shape imparting ability by thermoforming, resin films can be preferably used as the substrate. From the viewpoint of strength and thermoformability, preferred substrates include polyester-based films (PET-based films, etc.) and polyolefin-based films. One or both surfaces of the substrate may be subjected to a surface treatment such as application of a primer, corona discharge treatment, plasma treatment, etc., in the same manner as the adhesive side surface of the support film.

[0125] The thickness of the substrate is not particularly limited and can be selected depending on the purpose and mode of use of the laminate sheet. In some embodiments, the thickness of the substrate may be, for example, 0.5 μm or more, and from the viewpoint of the handleability of the substrate, it is preferably 2 μm or more, and may be 5 μm or more. The thickness of the substrate may be, for example, 200 μm or less, and from the viewpoint of thinning the adhesive body and the formability of the laminate sheet, it is preferably 150 μm or less, more preferably 100 μm or less, and may be 50 μm or less, 25 μm or less, or 10 μm or less. In addition, in a substrate-attached adhesive body, the thickness of the adhesive layer disposed on both sides of the substrate (thickness per side of the substrate) can be selected from the same range as the thickness of the substrate-less adhesive body described above.

[0126] <Laminated sheet> The method for producing the laminate sheet disclosed herein is not particularly limited. For example, a laminate sheet can be obtained by applying a pressure-sensitive adhesive composition to the release surface of a second film and curing (drying, crosslinking, reaction, etc.) it to form an adhesive body (adhesive layer), and then laminating a first film onto this adhesive body. Alternatively, a laminate sheet can be obtained by applying a pressure-sensitive adhesive composition to a first film and curing (drying, crosslinking, reaction, etc.) it to form an adhesive body, and then laminating the release surface of a second film onto this adhesive body. Alternatively, a laminate sheet can be produced by drying or curing a pressure-sensitive adhesive composition sandwiched between the release surface of a second film and the release surface of a first film to form an adhesive body. Alternatively, a laminate sheet can be produced by drying or curing a pressure-sensitive adhesive composition sandwiched between the release surface of a second film and the release surface of another release film (processing material) to form an adhesive body, and then peeling off the processing material to laminate a first film onto the exposed adhesive surface. Various conventionally known methods can be used to apply the pressure-sensitive adhesive composition. Specific examples of the coating method include roll coating, kiss roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and extrusion coating using a die coater.

[0127] The thickness of the first film is not particularly limited and may be selected, for example, from a range of approximately 2 μm to 500 μm. From the viewpoint of ease of handling of the first film during the production and use of the laminate sheet, the thickness of the first film is advantageously 5 μm or more, preferably 10 μm or more, and more preferably 25 μm or more. In some embodiments, the thickness of the first film is preferably 35 μm or more, more preferably 40 μm or more, and may be 45 μm or more, 50 μm or more, 60 μm or more, or 70 μm or more. Furthermore, from the viewpoint of avoiding an unnecessarily large thickness of the laminate sheet, the thickness of the first film is typically appropriately 300 μm or less, preferably 250 μm or less, and may be 200 μm or less, 190 μm or less, 150 μm or less, 130 μm or less, 110 μm or less, 90 μm or less, or 80 μm or less.

[0128] The thickness of the second film is not particularly limited and can be selected, for example, from a range of approximately 2 μm to 500 μm. From the same viewpoint as for the first film, the thickness of the second film is advantageously 5 μm or more, preferably 10 μm or more, and more preferably 25 μm or more. In some embodiments, the thickness is preferably 35 μm or more, more preferably 40 μm or more, and may be 45 μm or more, 50 μm or more, 60 μm or more, or 70 μm or more. Furthermore, the thickness of the second film is usually suitably 300 μm or less, preferably 250 μm or less, and may be 200 μm or less, 190 μm or less, 150 μm or less, 130 μm or less, or 110 μm or less. In some embodiments, the thickness of the second film may be 90 μm or less, or 80 μm or less.

[0129] (peel force) The laminated sheet disclosed herein has a peel strength (i.e., peel strength P 2A ) is suitably less than 10 N / 50 mm, and preferably 5 N / 50 mm or less. 2AIn a laminate sheet having a peel strength of 5 N / 50 mm or less, the second film has good peelability from the adhesive body even after the heat pressing, which is intended for thermoforming of the laminate sheet, and therefore workability is good when peeling the second film from the adhesive body. 2A The peeling force P is preferably 3 N / 50 mm or less, more preferably 2 N / 50 mm or less, may be 1.5 N / 50 mm or less, or may be 1.0 N / 50 mm or less. 2A Reducing this is also preferable from the viewpoint of avoiding the phenomenon in which the shape of the second surface of the adhesive body is distorted when the second film is peeled off from the adhesive body, or the first surface of the adhesive body is lifted from the first film or the substrate to which the first surface is attached.

[0130] On the other hand, from the viewpoint of preventing the second film from partially lifting off the adhesive surface of the formed laminated film during thermoforming or over time thereafter (for example, during storage of the formed laminated film), the peel force P 2A From this viewpoint, it is advantageous that the peel force P 2A is suitably 0.05 N / 50 mm or more (for example, more than 0.05 N / 50 mm), preferably 0.10 N / 50 mm or more, may be 0.15 N / 50 mm or more, may be 0.30 N / 50 mm or more, or may be 0.50 N / 50 mm or more.

[0131] When the first film of the laminate sheet disclosed herein is a release film, the peel strength of the first film from the adhesive body after heat pressing at 120°C for 1 minute (peel strength P 1A ) can be, for example, about 0.01 N / 50 mm to 3 N / 50 mm. In some embodiments, the peel force P 1A is the peeling force P 2AIt is preferable that the peeling force of the first film from the adhesive body after the heat pressing is lower than the peeling force of the second film from the adhesive body. The laminated sheet configured in this manner is used, for example, in a mode in which the first film is peeled from the adhesive body before the second film after thermoforming, and can suitably prevent the adhesive body from floating up from the second film when the first film is peeled off. From the viewpoint of more reliably preventing such a phenomenon, in some embodiments, the peeling force P 2A [N / 50mm] and peeling force P 1A Difference from [N / 50mm] (P 2A -P 1A ) is suitably 0.02 N / 50 mm or more, preferably 0.05 N / 50 mm or more, and may be 0.10 N / 50 mm or more.

[0132] When the first film of the laminate sheet disclosed herein is a release film, in some embodiments, the peel force of the first film from the adhesive body (peel force P 1B ) is the peeling force of the second film from the adhesive body (peel force P 2B ) is preferably lower. The laminated sheet configured in this manner can suitably prevent the adhesive body from floating up from the second film when peeling the first film, for example, in a use mode in which the first film is peeled off from the adhesive body before thermoforming (for example, a use mode including laminating another release film or a non-release member on the adhesive surface exposed after peeling the first film). From the viewpoint of more reliably preventing such a phenomenon, in some embodiments, the peel force P 2B [N / 50mm] and peeling force P 1B Difference from [N / 50mm] (P 2B -P 1B ) is suitably 0.02 N / 50 mm or more, preferably 0.05 N / 50 mm or more, and may be 0.10 N / 50 mm or more. 1B and P 2B The preferred range of the peeling force P 1A and P 2A and the like.

[0133] The peel strength of the second film after heat pressing, P 2A The peel strength P of the first film after heat pressing is measured by the method described in the Examples below. 1A The peel force P in a laminate sheet in which the first film is a release film is also measured in the same manner. 2A To measure the normal peel strength P, first peel off the first film and laminate a non-peeling resin film (for example, a PET film with a thickness of about 50 μm) on the exposed adhesive surface, then heat press the laminate at 120°C for 1 minute and measure. 2B ,P 1B The peel strength after heat pressing P is the same as that of the laminated sheet to be evaluated except that heat pressing is not performed. 2A ,P 1A is measured in the same manner as

[0134] <Application> The laminate sheet disclosed herein is suitable for use in a mode in which, after thermoforming, the release film is peeled off and the adhesive surface is attached to an adherend. Taking advantage of these characteristics, the laminate sheet can be preferably used, for example, in a mode in which the adhesive contained in the laminate sheet (which may be an adhesive whose first surface is fixed to a first film or the non-releasable surface of another member) is attached to the surface of a non-planar adherend, such as a member constituting various portable devices, for fixing, joining, heat dissipation, heat transfer, molding, decoration, protection, support, etc. of the member. Here, "portable" does not simply mean being portable, but also means having a level of portability that allows an individual (average adult) to carry it relatively easily. Examples of portable devices herein include mobile phones, smartphones, tablet computers, notebook computers, various wearable devices, digital cameras, digital video cameras, audio equipment (portable music players, IC recorders, etc.), calculators (calculators, etc.), portable game devices, electronic dictionaries, electronic organizers, e-books, in-vehicle information equipment, portable radios, portable televisions, portable printers, portable scanners, and portable modems, as well as mechanical wristwatches, pocket watches, flashlights, and hand mirrors. Examples of components constituting the above portable electronic devices include optical films and display panels used in image display devices such as liquid crystal displays and organic EL displays. The laminate sheet disclosed herein can also be preferably used for fixing, joining, heat dissipation, heat transfer, molding, decoration, protection, and support of various components in automobiles, home appliances, etc., in a manner in which the adhesive contained in the laminate sheet is attached to the components.

[0135] The laminate sheet disclosed herein can be preferably used in an embodiment in which at least a portion of the laminate sheet is heated and pressurized to form it into a non-planar shape (three-dimensional shape), and then the adhesive body contained in the laminate sheet is attached to an adherend. The time from the forming to the attachment of the adhesive body can be, for example, 1 minute or more, 5 minutes or more, 30 minutes or more, 1 hour or more, 6 hours or more, or 1 day or more. The upper limit of the time from the forming to the attachment of the adhesive body is not particularly limited and can be, for example, within 1 year or 6 months. The heating temperature when forming the laminate sheet into a non-planar shape can be, for example, 90°C or more, 100°C or more, 110°C or more, or 120°C or more. The heating temperature can also be, for example, 250°C or less, 220°C or less, 200°C or less, 180°C or less, or 160°C or less. The time for the heating and pressurization can be, for example, 0.5 seconds or more, 1 second or more, or 5 seconds or more, and can be 30 minutes or less, 5 minutes or less, 60 seconds or less, or 40 seconds or less.

[0136] The matters disclosed by this specification include the following: [1] A sheet-shaped adhesive body, a first film laminated on a first surface of the adhesive body, and a second film laminated on a second surface of the adhesive body, The second film includes a resin film and a release-treated layer provided on at least the surface of the resin film on the side of the adhesive body, and satisfies the following conditions: A Young's modulus at 85°C of 500 MPa or more; and Young's modulus at 120°C is 500 MPa or less; It is a release film that satisfies the above requirements. A laminated sheet, wherein the second surface of the adhesive body has a maximum height Rz of 1000 nm or less. [2] The laminate sheet according to [1], wherein the resin film included in the second film is a polyester film. [3] The laminate sheet according to [2], wherein the second film has a Young's modulus at 85°C of 500 MPa or more and 2000 MPa or less, and a Young's modulus at 120°C of 70 MPa or more and 500 MPa or less. [4] The laminate sheet according to [1], wherein the resin film included in the second film is a polyolefin-based film. [5] The laminate sheet according to [4], wherein the second film has a Young's modulus at 85°C of 500 MPa or more and 1500 MPa or less, and a Young's modulus at 120°C of 2 MPa or more and 100 MPa or less. [6] The laminate sheet according to any one of [1] to [5] above, wherein the second film has a ratio of Young's modulus at 85°C to Young's modulus at 120°C of 3 or more. [7] The above adhesive body is stretched 300% under the conditions of a temperature of 23°C, a pulling speed of 200 mm / min, and after holding at the 300% stretched position for 150 seconds, the measured stress is 50 N / cm 2 The laminate sheet according to any one of the above [1] to [6], which is: [8] The laminate sheet according to any one of [1] to [7] above, wherein the peel strength of the second film from the adhesive body after heat pressing at 120°C for 1 minute is 0.10 N / 50 mm or more and 5 N / 50 mm or less. [9] The laminate sheet according to any one of [1] to [8] above, wherein the first film is a support film adhered to the first surface of the pressure-sensitive adhesive body.

[10] The laminate sheet according to any one of [1] to [8] above, wherein the first film is a release film.

[11] The laminate sheet according to

[10] , wherein the peel strength of the first film from the adhesive body is lower than the peel strength of the second film from the adhesive body.

[12] The laminate sheet according to any one of [1] to

[11] above, wherein the adhesive body is an adhesive layer made of an adhesive.

[13] The laminate sheet according to any one of the above [1] to

[12] , which has a planar shape and may be wound into a roll.

[14] A laminated sheet roll in which the laminated sheet according to any one of [1] to

[13] above is wound.

[15] A release film which is the second film in the laminate sheet according to any one of [1] to

[13] above.

[0137]

[21] A film comprising a resin film and a release treatment layer provided on at least one surface of the resin film, and satisfying the following conditions: A Young's modulus at 85°C of 500 MPa or more; and Young's modulus at 120°C is 500 MPa or less; Fulfilling A release film, wherein the maximum height Rz of the surface of the release treatment layer is 1000 nm or less.

[22] The release film according to

[21] above, wherein the resin film is a polyester film.

[23] The release film according to

[22] above, having a Young's modulus at 85°C of 500 MPa or more and 2000 MPa or less, and a Young's modulus at 120°C of 70 MPa or more and 500 MPa or less.

[24] The release film according to

[21] above, wherein the resin film is a polyolefin-based film.

[25] The release film according to the above

[24] , having a Young's modulus at 85°C of 500 MPa or more and 1500 MPa or less, and a Young's modulus at 120°C of 2 MPa or more and 100 MPa or less.

[26] The release film according to any one of the above

[21] to

[25] , wherein the ratio of Young's modulus at 85°C to Young's modulus at 120°C is 3 or more.

[27] The release film according to any one of the above

[21] to

[26] , which has an elongation at break at 120°C of 230% or more.

[28] The release film according to any one of the above

[21] to

[27] , which is used as a second film of the laminate sheet according to any one of the above [1] to

[13] .

[29] A method for producing the release film according to any one of

[21] to

[28] above, comprising: applying a release treatment agent to one surface of the resin film; and heating the resin film coated with the release treatment agent to a temperature of 40°C or higher and 110°C or lower.

[0138]

[31] Preparing the laminate sheet according to any one of [1] to

[13] above; and heating and pressing at least a partial region of the laminate sheet to form it into a non-planar shape.

[32] The processing method according to

[31] above, wherein the heating is carried out at a temperature of 90°C or higher and 250°C or lower.

[33] The processing method according to

[31] or

[32] , wherein the non-planar shape includes a curved shape having a concave or convex shape on one side of the laminated sheet and a convex shape or a concave shape corresponding to the concave shape on the other side.

[34] A laminated sheet including a region formed into a non-planar shape, which is processed by the processing method according to any one of

[31] to

[33] above.

[35] A method for joining a first adherend surface having a non-planar shape to a second adherend surface having a non-planar shape corresponding to (complementary to) the first adherend surface, comprising: preparing a laminated sheet formed into an appropriate non-planar shape corresponding to the non-planar shape of the surface of the first adherend, wherein the laminated sheet comprises a sheet-shaped adhesive body, a first film which is a release film laminated on a first surface of the adhesive body, and a second film which is a release film laminated on a second surface of the adhesive body, the second film comprising a resin film and a release treatment layer provided on at least the surface of the resin film on the adhesive body side, the second film having a Young's modulus of 500 MPa or more at 85°C and a Young's modulus of 500 MPa or less at 120°C, and a maximum height Rz of 1000 nm or less on the second surface of the adhesive body; Peeling the first film from the adhesive body and attaching the first surface of the adhesive body to the surface of a first adherend; and peeling off the second film and attaching the second surface of the adhesive body to the surface of a second adherend; The joining method includes the steps of:

[36] The bonding method according to

[35] above, wherein the laminate sheet formed into the non-planar shape is a laminate sheet formed into the non-planar shape from the laminate sheet according to any one of [1] to

[13] above, in which the first film is a release film. [Example]

[0139] Several examples of the present invention will be described below, but it is not intended that the present invention be limited to these specific examples. In the following description, "parts" and "%" are by weight unless otherwise specified.

[0140] <Measurement and Evaluation> (Young's modulus) The film to be evaluated is cut into a dumbbell shape with a total length of 120 mm and a parallel section width of 10 mm to prepare a test specimen. This test specimen is placed in a tensile testing machine with a chuck distance of 30 mm and placed in a measurement atmosphere at 85°C or 120°C. After 2 minutes, the tensile test begins at a tensile speed of 50 mm / min. Five points in the small deformation region (within 5% strain) are selected from the obtained stress (vertical axis) - strain (horizontal axis) curve, and the Young's modulus is calculated from the slope obtained from a linear approximation equation.

[0141] (elongation at break) In the measurement of the Young's modulus, the elongation at break is determined from the results of a tensile test carried out in a measurement atmosphere at 120°C.

[0142] (Maximum height of adhesive surface Rz) The maximum height Rz of the second surface (adhesive surface on the second film side) of the adhesive body is measured as follows: The laminated sheet is cut to a size of 20 mm x 50 mm to prepare an evaluation sample. The second film is peeled off from this evaluation sample to expose the adhesive surface (second surface), one drop of water is placed on a slide glass S1214 (manufactured by Matsunami Glass Industry Co., Ltd.), the first film side (back side of the first film side) of the evaluation sample is placed on top of it, and the first film side is adhered to the slide glass, and the maximum height Rz of the adhesive surface (second surface) is measured under the following conditions. Equipment: Optical interference type surface roughness measuring device (Veeco, Wyko NT-9100) ·Measurement area / times: 622μm×467μm (Objective lens: 10x, FOV (internal lens): 1.0x) Measurement mode: VSI (Vertical Scan Interferometry) Back scan: 5μm ·Measurement distance: 10μm Threshold: 0.1% Scan speed: 1x (Single scan) From the data set obtained by the measurement, the height Rp of the highest peak above the mean line of the roughness curve and the depth Rv of the lowest valley below the mean line are determined, and the sum of Rp and Rv is defined as the maximum height Rz. Measurements are carried out five times (i.e., N=5), and the average value is used. If the first film is a release film, the first film is peeled off and the exposed adhesive surface (first surface) is attached to the slide glass, and then the second film is peeled off from the sample, and the maximum height Rz of the exposed adhesive surface (second surface) is measured.

[0143] (Maximum height Rz of the release treatment layer surface of the second film) The maximum height Rz of the release treatment layer surface (release treatment surface) of the second film can be measured under the same conditions as those for measuring the maximum height Rz of the adhesive surface. Specifically, in an environment of 23°C and 50% RH, a drop of water is dropped onto a glass slide S1214 (manufactured by Matsunami Glass Industry Co., Ltd.), and the second film to be measured is placed on top of it with the surface opposite to the surface to be measured (specifically, the release treatment layer surface) facing the glass slide, so that the surface of the second film not to be measured is placed in close contact with the glass slide. Next, the maximum height Rz of the release treatment layer surface of the second film placed on the glass slide is measured. The measurement conditions are the same as those for measuring the maximum height Rz of the adhesive body. Note that when the maximum height Rz [nm] of the release treatment layer surface of the second film in each example was measured using the above method, it was within ±10% of the maximum height Rz [nm] of the second surface of the adhesive body in the corresponding example.

[0144] (residual stress) The adhesive body (adhesive layer) is cut into a size of 4 cm x 4 cm, and while peeling off the release film as needed, the adhesive body is folded to a width of 1 cm, taking care not to trap air bubbles. The evaluation sample thus obtained is set in a tensile tester with a chuck distance of 2 cm under a measurement environment of 23 ° C and 50% RH, and pulled to 300% at a pulling speed of 200 mm / min (the chuck distance after pulling is 8 cm). The sample is fixed (held) at the 300% pulled position for 150 seconds, and the stress value [N] after 150 seconds is read, and the cross-sectional area [cm] of the adhesive body is measured. 2 ] is divided by the residual stress [N / cm 2 The cross-sectional area of ​​the adhesive body is specifically calculated by multiplying the thickness of the adhesive body [cm] by 4. If the sample breaks before reaching 300% elongation during the tensile test, it is recorded as "break."

[0145] (Peeling force of second film (P 2A )) The laminate sheet to be evaluated is sandwiched between two flat metal plates heated to 120°C and hot-pressed for 1 minute, then returned to room temperature and cut into 50mm wide strips to prepare test specimens. The test specimens are placed in a tensile tester under a measurement environment of 23°C and 50% RH, and the peel force of the second film from the adhesive body (adhesive layer) is measured at a peel angle of 180° and a tensile speed of 300mm / min.

[0146] (Appearance after peeling) If the peeling treatment caused obvious deformation (shrinkage, waviness, etc.) or abnormal appearance such as cloudiness in the resin film, it was rated as "poor," and if no abnormal appearance was observed, it was rated as "good."

[0147] (Laminated sheet molding test) 2 to 4, a mold 60 is prepared, which includes a lower mold 62 having a recess 622 and an upper mold 64 (not shown in FIG. 2) having a protrusion 642 shaped to correspond to the recess 622. In FIG. 4, the left and right ends of the protrusion 642 are arc-shaped with a curvature radius of 65 mm. A test piece 70, which is obtained by cutting the laminate sheet to be evaluated into a rectangle having a width of 100 mm and a length of 200 mm, is placed on the lower mold 62 so that both longitudinal ends of the test piece 70 extend beyond both longitudinal ends of the recess 622 of the lower mold 62 and the center of the width of the test piece 70 coincides with the center of the width of the recess 622 in a plan view (see the imaginary lines in FIG. 4). The upper mold 64 is lowered and hot press molding is performed at 120°C for 1 minute. After the mold 60 is cooled to 40°C, the upper mold 64 is raised and the test piece 70 is removed.

[0148] The obtained molded sheet (test piece after molding) is visually observed, and if a tear occurs in the second film, it is evaluated as "torn," and if no tear is observed, it is evaluated as "not torn." Furthermore, if peeling or lifting of the second film from the pressure-sensitive adhesive layer occurs in areas where the test piece protrudes from both ends of the longitudinal direction of the recess 622 or in areas molded along the arc shape of the protrusion 642, it is evaluated as "peeling," and if peeling or lifting is not observed, it is evaluated as "not peeling."

[0149] (Storage test after molding) The molded sheet (molded test piece) obtained by the above molding test is stored in an environment of 23°C and 50% RH for 24 hours, and then the presence or absence of peeling or lifting of the second film from the adhesive body (adhesive layer) is observed. If peeling or lifting is observed, it is evaluated as "poor appearance retention," and if peeling or lifting is not observed, it is evaluated as "good appearance retention."

[0150] (with or without yuzu skin) The laminate sheet was cut into A4 size pieces to be used as evaluation samples. This evaluation sample (a laminate sheet having a first film / adhesive layer / second film configuration) was held flat and placed between a point light source and a screen, with the second film side of the sample facing the point light source, at an angle of approximately 90 degrees relative to the light from the point light source. The distance from the point light source to the screen was approximately 100 cm, and the sample was placed approximately halfway down that distance. The point light source was turned on in a darkroom at 23°C and 50% RH, and the presence or absence of citrus peel was evaluated by visually observing the image projected onto the screen through the sample. For example, a xenon lamp C2577 manufactured by Hamamatsu Photonics KK can be used as the point light source.

[0151] (Distortion appearance) The laminate sheet was cut into a 4 cm x 8 cm piece to serve as the evaluation sample. This evaluation sample (a laminate sheet having a first film / adhesive layer / second film configuration) was placed in a tensile tester with a chuck distance of 4 cm under a measurement environment of 23°C and 50% RH, and stretched to 300% at a tensile speed of 200 mm / min (the chuck distance after stretching was 12 cm). The sample was held at the 300% stretch position for 150 seconds and then removed. If the sample broke before reaching 300% elongation during the tensile test, it was recorded as "fracture." After the tensile test and 150-second hold, the evaluation sample was held flat and placed between a point light source and a screen, with the second film side of the sample facing the point light source and at an angle of approximately 45 degrees relative to the light from the point light source. The distance from the point light source to the screen was approximately 100 cm, and the sample was placed approximately halfway down that distance. The point light source was turned on in a darkroom at 23°C and 50% RH, and the image projected onto the screen through the sample was visually observed to evaluate the appearance of distortion. If the image was free of distortion, it was rated "good," and if distortion was observed, it was rated "poor." The point light source may be, for example, a xenon lamp C2577 manufactured by Hamamatsu Photonics KK

[0152] <Production of laminated sheets> (Example 1) 40 parts of n-butyl acrylate (BA), 40 parts of cyclohexyl acrylate (CHA), 20 parts of 4-hydroxybutyl acrylate (4HBA), 0.05 parts of 2,2-dimethoxy-1,2-diphenylethan-1-one (manufactured by IGM Regins, trade name "Omnirad 651") as a photopolymerization initiator, and 0.05 parts of 1-hydroxycyclohexyl-phenyl-ketone (manufactured by IGM Regins, trade name "Omnirad 184") were mixed and irradiated with ultraviolet light under a nitrogen atmosphere to produce a partially polymerized product (monomer syrup). 0.3 parts of 1,6-hexanediol diacrylate was added to 100 parts of the resulting monomer syrup and mixed uniformly to prepare PSA composition C1.

[0153] A silicone-based release treatment agent S1 was prepared by dissolving 92 parts of a vinyl-containing silicone-based release agent (KS-3703, manufactured by Shin-Etsu Chemical Co., Ltd.), 8 parts of a release control agent (KS-3800, manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.2 parts of a platinum catalyst (CAT-PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd.) in heptane (dilution solvent) at a total concentration of 2.0%. A 100 μm-thick polyolefin film POL-1 (Q16CK, manufactured by Toray Industries, Inc.) with one rough surface and the other smooth surface was also prepared. The release treatment agent S1 was applied to the smooth surface of this polyolefin film POL-1 using a Meyer bar #5, dried by heating at 80°C for 3 minutes, and then aged in a 40°C environment for 72 hours. In this way, a release film R1 was obtained, having a release treatment layer formed from the silicone-based release treatment agent S1 on the smooth surface of the polyolefin film POL-1.

[0154] This release film R1 was used as the second film to prepare a laminate sheet in which a first film (support film) was adhered and laminated to the first surface of an adhesive body consisting of an adhesive layer, and a second film was laminated to the second surface of the adhesive. Specifically, the above-mentioned adhesive composition C1 was applied to the release-treated surface of release film R1, and a release film R0 (Toray Advanced Film Co., Ltd., Cerapeel TKA07(07)) consisting of a 75 μm-thick transparent polyethylene terephthalate (PET) film with one side treated with a silicone-based release agent was placed over the film to block air. The adhesive composition was cured by UV irradiation to form a 50 μm-thick adhesive layer. Release film R0 was peeled from the adhesive layer, and an 80 μm-thick triacetyl cellulose (TAC) film (Fujifilm Corporation) was attached to the exposed adhesive surface. In this way, a laminate sheet was obtained in which a TAC film (support film), an adhesive layer, and release film R1 (second film) were laminated in this order. For this laminate sheet, the peel strength (P 2A ) was measured and found to be in the range of 0.10 to 5N / 50mm.

[0155] (Example 2) A pressure-sensitive adhesive composition C2 was prepared in the same manner as in the preparation of pressure-sensitive adhesive composition C1, except that the amount of HDDA used was changed from 0.3 parts to 0.7 parts. A laminate sheet according to this example was obtained in the same manner as in Example 1, except that the obtained pressure-sensitive adhesive composition C2 was used.

[0156] (Example 3) Silicone-based release treatment agent S2 was prepared by dissolving 88 parts of a vinyl-containing silicone-based release agent (Shin-Etsu Chemical Co., Ltd., KS-3703), 12 parts of a release control agent (Shin-Etsu Chemical Co., Ltd., KS-3800), and 0.2 parts of a platinum catalyst (Shin-Etsu Chemical Co., Ltd., CAT-PL-50T) in heptane at a total concentration of 2.0%. Silicone-based release treatment agent S2 was applied to one side of a 19 μm-thick PET film PET-1 (Toyobo Co., Ltd., TF8) using a Meyer bar #5. The film was then heated to 80°C for 3 minutes, dried, and then aged for 72 hours at 40°C to obtain release film R2. This release film R2 was used as the second film, and the laminate sheet of this example was obtained in the same manner as in Example 1.

[0157] (Example 4) The laminated sheet of this example was obtained in the same manner as in Example 3, except that the adhesive composition C2 was used instead of the adhesive composition C1.

[0158] (Example 5) A 100 μm thick polyolefin film POL-1 (Toray Industries, Inc., Q16CK) was prepared, and release treatment agent S1 was applied to the rough surface of this polyolefin film POL-1 using a Mayer bar #5, and the film was dried by heating at 80° C. for 3 minutes, and then aged for 72 hours in an environment of 40° C. In this way, a release film R3 was obtained, having a release treatment layer formed from the silicone release treatment agent S1 on the rough surface of the polyolefin film POL-1. A laminated sheet according to this example was obtained in the same manner as in Example 1, except that this release film R3 was used as the second film.

[0159] (Example 6) A pressure-sensitive adhesive composition C3 was prepared in the same manner as in the preparation of pressure-sensitive adhesive composition C1, except that the amount of HDDA used was changed from 0.3 part to 1.0 part. A laminate sheet according to this example was obtained in the same manner as in Example 5, except that the obtained pressure-sensitive adhesive composition C3 was used.

[0160] (Example 7) Instead of the PET-based film PET-1, a 100 μm thick PET-based film PET-2 (R41, manufactured by Toray Industries, Inc.) was used. The rest of the process was the same as for the preparation of release film R2 to obtain release film R4. The laminate sheet of this example was obtained in the same manner as for the laminate sheet of Example 3, except that this release film R4 was used as the second film.

[0161] (Example 8) A laminate sheet according to this example was obtained in the same manner as in Example 7, except that pressure-sensitive adhesive composition C3 was used.

[0162] The laminate sheets according to the examples were subjected to the above-mentioned measurements and evaluations, and the results obtained are shown in Table 1.

[0163] [Table 1]

[0164] As shown in Table 1, all of the laminate sheets of Examples 1 to 4 exhibited good thermoformability in the molding test, and lifting and peeling of the second film (release film) during storage after molding were suppressed. Furthermore, the adhesive surfaces (second surfaces) of the laminate sheets of Examples 1 to 4 were free of yuzu peel and had good distortion appearances. In contrast, in Examples 5 and 6, where the Rz of the adhesive surface was too high, yuzu peel was observed and the appearance was not good. Furthermore, in Examples 7 and 8, where the 120°C Young's modulus of the second film was too high, tearing and peeling occurred during molding.

[0165] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific examples exemplified above. [Explanation of symbols]

[0166] 10 Sticky substance 10A First side (first adhesive side) 10B Second side (second adhesive side) 31 First Film 32 Second film (release film) 50 laminated sheets 60 molds 62 Lower mold 622 recess 64 Upper mold 642 Convex 70 test specimens

Claims

1. The adhesive sheet includes a sheet-shaped adhesive body, a first film laminated on a first surface of the adhesive body, and a second film laminated on a second surface of the adhesive body, The second film includes a resin film and a release treatment layer provided on at least the surface of the resin film on the pressure-sensitive adhesive side, and satisfies the following conditions: A Young's modulus at 85°C of 500 MPa or more; and Young's modulus at 120°C is 500 MPa or less; It is a release film that satisfies the above requirements. A laminated sheet, wherein the maximum height Rz of the second surface of the adhesive body is 1000 nm or less.

2. The adhesive body was stretched to 300% at a temperature of 23°C and a pulling rate of 200 mm / min, and the stress measured after holding the stretched body at 300% for 150 seconds was 50 N / cm 2 2. The laminate sheet according to claim 1, wherein:

3. The laminated sheet according to claim 1 or 2, wherein the first film is a support film adhered to the first surface of the adhesive body.

4. 3. The laminated sheet according to claim 1, wherein the first film is a release film.

5. The laminated sheet according to claim 4 , wherein the peel strength of the first film from the adhesive body is lower than the peel strength of the second film from the adhesive body.

6. The laminated sheet according to claim 1 or 2, wherein the adhesive body is an adhesive layer made of an adhesive.

7. A laminated sheet roll in which the laminated sheet according to claim 1 or 2 is wound.

8. The present invention relates to a film that includes a resin film and a release treatment layer provided on at least one surface of the resin film, and satisfies the following conditions: A Young's modulus at 85°C of 500 MPa or more; and Young's modulus at 120°C is 500 MPa or less; Fulfilling A release film, wherein the maximum height Rz of the surface of the release treatment layer is 1000 nm or less.

9. Preparing the laminate sheet according to claim 1 or 2; and heating and pressing at least a partial region of the laminate sheet to form it into a non-planar shape.

Images