Pressure sensitive adhesive sheet and utilization thereof

Abstract

To provide a pressure sensitive adhesive sheet capable of forming a junction with high deformation resistance and high impact resistance.SOLUTION: A pressure sensitive adhesive sheet includes an adhesive layer. The pressure sensitive adhesive sheet has characteristics (a) and (b): (a) an elastic modulus measured by a tensile test is 3.0 MPa or more; and (b) an impact resistance measured by a shear impact test is 2.0 J / (10 mm)2 or more.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an adhesive sheet, a film member with an adhesive sheet, and a method for manufacturing a laminate.

Background Art

[0002] Generally, an adhesive (also referred to as a pressure-sensitive adhesive. The same applies hereinafter.) exhibits a state of a soft solid (viscoelastic body) in a temperature range near room temperature and has a property of easily adhering to an adherend by pressure. Taking advantage of such properties, adhesives are typically widely used in various fields in the form of an adhesive sheet including an adhesive layer. As a technical document regarding adhesive sheets, Patent Document 1 can be cited.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Adhesives are required to have various characteristics depending on the application. Among these characteristics, there are some that are difficult to achieve at a high level, such as when attempting to improve one characteristic, the other characteristic tends to deteriorate. As an example of characteristics that are difficult to achieve simultaneously, there are a property of being difficult to deform with respect to stress (hereinafter, also referred to as "deformation resistance") and a property of withstanding impact and maintaining the bond with the adherend (hereinafter, also referred to as "impact resistance").

[0005] Therefore, an object of the present invention is to provide an adhesive sheet capable of forming a joint with high deformation resistance and high impact resistance. Another object of the present invention is to provide a film member with an adhesive sheet configured to include the above adhesive sheet. Still another object of the present invention is to provide a method for manufacturing a laminate using the above adhesive sheet.

Means for Solving the Problem

[0006] According to this specification, an adhesive sheet including an adhesive layer is provided, which has the following characteristics (a) and (b). (a) The elastic modulus measured by the following tensile test is 3.0 MPa or more. (b) The impact resistance measured by the following shear impact test is 2.0 J / (10 mm) 2 or more. [Tensile Test] The adhesive layer is irradiated with ultraviolet rays under the conditions of an illuminance of 300 mW / cm 2 and an integrated light quantity of 3000 mJ / cm 2 Then, after aging at 50°C for 48 hours, the adhesive layer is cut into a size of 10 mm in width and 150 mm in length to prepare a test piece. In an environment of 23°C and 50% RH, using a tensile testing machine, a tensile test of the test piece is performed under the conditions of a chuck distance of 120 mm and a tensile speed of 50 mm / min to obtain a stress-displacement curve (hereinafter, also referred to as the "S-S curve"), and the elastic modulus [MPa] (hereinafter, also referred to as the tensile elastic modulus) is calculated from its initial slope. [Shear Impact Test] A shear impact test is performed using a pendulum-type adhesive shear impact tester based on JIS K6855. As a measurement sample, after bonding the first surface of the 10 mm square adhesive layer to the center of a 25 mm square and 1.7 mm thick chemically strengthened glass plate, the second surface of the adhesive layer is attached to the center of a 40 mm square stainless steel plate (SUS304BA plate), crimped with a 5 N weight for 10 seconds, and then autoclave treatment (50°C, 0.5 MPa, 15 minutes) is performed. After irradiating with ultraviolet rays from the glass plate side under the conditions of an illuminance of 300 mW / cm 2 and an integrated light quantity of 3000 mJ / cm 2 and then aging at 50°C for 48 hours is used. Fix the above measurement sample so that the above stainless steel plate is on the lower side. In an environment of 23°C and 50% RH, measure the absorption energy [J] when hitting the outer peripheral side surface of the above glass plate with a hammer under the conditions of a hammer energy of 2.75 J and a hammer speed (impact speed) of 3.5 m / s, and thereby obtain the impact resistance [J / (10 mm) 2 .

[0007] By satisfying the above characteristic (a), for example, in the use state of the above adhesive sheet, the above adhesive layer can exhibit high deformation resistance. Since the adhesive sheet satisfying the above characteristics (a) and (b) can form a joint with high deformation resistance and high impact resistance, it can be preferably used, for example, for the purpose of joining and fixing members.

[0008] Further, according to this specification, there is provided an adhesive sheet including an adhesive layer, wherein the adhesive layer contains a polymer (A) and a photoreactive monomer (B). In some embodiments of the above adhesive sheet, the above photoreactive monomer (B) includes a compound B1 having a ring structure and two or more ethylenically unsaturated groups in the molecule. It is preferable that the above compound B1 has a molecular weight of 100 g / mol or more per one of the above ethylenically unsaturated groups. According to the adhesive sheet having such an adhesive layer, a joint with high deformation resistance and high impact resistance can be preferably formed.

[0009] The adhesive sheet according to any of the embodiments disclosed herein may satisfy the following characteristic (c). The adhesive sheet satisfying the characteristic (c) can be preferably used, for example, for the purpose of joining and fixing members, etc. (c) The peel strength measured by the following peel test is 1.0 N / 10 mm or more. [Peel Test] Press the first surface of the above adhesive layer onto a glass plate by reciprocating a 2 kg rubber roller once, and after performing autoclave treatment (50°C, 0.5 MPa, 15 minutes), from the glass plate side, the illuminance is 300 mW / cm 2 , and the integrated light quantity is 3000 mJ / cm 2Irradiate with ultraviolet rays under the conditions described above. After aging this at 50°C for 48 hours, in an environment of 23°C and 50% RH, using a tensile testing machine, measure the peel strength when peeling the test piece from the glass plate under the conditions of a peel angle of 180 degrees and a tensile speed of 60 mm / min.

[0010] According to this specification, there is provided a film member with an adhesive sheet, including any one of the adhesive sheets disclosed herein and a film member joined to the adhesive layer of the adhesive sheet. According to the film member with the adhesive sheet, a joint with high deformation resistance and high impact resistance can be preferably formed.

[0011] According to this specification, there is provided a method for manufacturing a laminate, including, in this order, bonding any one of the adhesive sheets disclosed herein to an adherend and irradiating the adhesive sheet with ultraviolet rays to photocure the adhesive layer. According to such a method, a laminate having both high impact resistance and high deformation resistance can be manufactured.

[0012] In addition, combinations of the above-described elements as appropriate may also be included in the scope of the invention for which patent protection is sought in this patent application.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0014] Hereinafter, preferred embodiments of the present invention will be described. Matters other than those specifically mentioned in this specification and necessary for the implementation of the present invention can be understood by those skilled in the art based on the teachings regarding the implementation of the invention described in this specification and the common general knowledge in the art at the time of filing. The present invention can be implemented based on the content disclosed in this specification and the common general knowledge in the relevant field. In the following drawings, members and parts having the same function may be denoted by the same reference numerals and may be described, and duplicate descriptions may be omitted or simplified. In addition, the embodiments described in the drawings are schematized for clearly explaining the present invention and do not necessarily accurately represent the size and scale of the actually provided product.

[0015] In this specification, the "acrylic polymer" refers to a polymer derived from a monomer component containing more than 50% by weight of acrylic monomers, and is also referred to as an acrylic polymer. The above acrylic monomer refers to a monomer having at least one (meth)acryloyl group in one molecule. In addition, in this specification, "(meth)acryloyl" means comprehensively referring to acryloyl and methacryloyl. Similarly, "(meth)acrylate" means comprehensively referring to acrylate and methacrylate, and "(meth)acrylic" means comprehensively referring to acrylic and methacrylic. In this specification, "mass" and "weight" shall be regarded as having the same meaning.

[0016] In this specification, the "photoreactive monomer" is a compound having at least one functional group (photoreactive functional group) in the molecule whose reaction can proceed by light irradiation, and typically is a compound having at least one ethylenically unsaturated group in the molecule as the above photoreactive functional group. The photoreactive monomer referred to here may be any monomer that can cause a reaction, for example, it may itself be a polymer such as an oligomer or a polymer (for example, a polymer having at least one ethylenically unsaturated group in the molecule).

[0017] <Configuration example of the adhesive sheet> A configuration example of the adhesive sheet disclosed herein is shown in FIG. 1. This adhesive sheet 1 is configured as a single-sided adhesive sheet (a single-sided adhesive sheet with a support) including an adhesive layer 10 having one surface 10A as an attachment surface (adhesive surface) to an adherend, and a support 20 laminated on the other surface 10B of the adhesive layer 10. The adhesive layer 10 is joined to one surface 20A of the support 20. As the support 20, for example, a resin film such as a polyester film can be used. The support 20 may be an optical film such as a polarizing plate. In the example shown in FIG. 1, the adhesive layer 10 has a single-layer structure. Before use (before attachment to the adherend), the adhesive sheet 1 can be in the form of an adhesive sheet 50 with a release liner, for example, as shown in FIG. 1, where the adhesive surface 10A is protected by a release liner 30 whose at least the adhesive layer side is a releasable surface (release surface). Alternatively, the second surface 20B of the support 20 (the surface opposite to the first surface 20A, also referred to as the back surface) is a release surface, and the adhesive surface 10A may be protected by winding or laminating such that the adhesive surface 10A abuts against the second surface 20B of the support 20.

[0018] The release liner is not particularly limited, and for example, a release liner obtained by subjecting the surface of a liner base material such as a resin film or paper to a release treatment, a release liner made of a low-adhesion material such as a fluoropolymer (such as polytetrafluoroethylene) or a polyolefin resin (such as polyethylene or polypropylene), etc. can be used. For the above-mentioned release treatment, for example, a release treatment agent such as a silicone-based or long-chain alkyl-based release treatment agent can be used. In some embodiments, a resin film subjected to a release treatment can be preferably adopted as the release liner.

[0019] The pressure-sensitive adhesive sheet disclosed herein may be in the form of a supportless double-sided pressure-sensitive adhesive sheet composed of a pressure-sensitive adhesive layer. As shown in FIG. 2, before use, the supportless double-sided pressure-sensitive adhesive sheet 2 may be in a form protected by release liners 31 and 32 in which each surface 10A, 10B of the pressure-sensitive adhesive layer 10 has at least the side of the pressure-sensitive adhesive layer as a releasable surface (release surface). Alternatively, the back surface (the surface opposite to the pressure-sensitive adhesive side) of the release liner 31 may be the release surface, and the pressure-sensitive adhesive surfaces 10A, 10B may be protected by winding or laminating the pressure-sensitive adhesive surface 10B so as to contact the back surface of the release liner 31. Such a supportless double-sided pressure-sensitive adhesive sheet can be used, for example, by joining a support to one surface of the pressure-sensitive adhesive layer. Further, the pressure-sensitive adhesive sheet disclosed herein may be in the form of a double-sided pressure-sensitive adhesive sheet with a support in which pressure-sensitive adhesive layers are laminated on each of one surface and the other surface of a sheet-like support. The support in such a form of pressure-sensitive adhesive sheet can be, for example, a resin film such as a polyester film or an optical film such as a polarizing plate.

[0020] The pressure-sensitive adhesive sheet disclosed herein can be a component of a film member with a pressure-sensitive adhesive sheet in which a film member is joined to one surface of the pressure-sensitive adhesive layer. For example, the pressure-sensitive adhesive sheet 1 shown in FIG. 1 can be a component of a film member 100 with a pressure-sensitive adhesive sheet in which a film member 70 is joined to one surface 10A of the pressure-sensitive adhesive layer 10 as shown in FIG. 3. The film member can be, for example, an electromagnetic wave-transmissive metallic gloss member or a polarizing plate or other optical film as described in JP-A-2018-69462.

[0021] <Properties of the pressure-sensitive adhesive sheet> (Tensile modulus of elasticity) The pressure-sensitive adhesive sheet disclosed herein preferably has a tensile elastic modulus of 3.0 MPa or more for the pressure-sensitive adhesive layer (which may be a pressure-sensitive adhesive layer formed using any of the pressure-sensitive adhesive compositions disclosed herein). The above tensile elastic modulus is measured by the tensile test described above, and more specifically, it is measured by the method described in the examples below. A pressure-sensitive adhesive layer with a higher tensile elastic modulus tends to exhibit better deformation resistance. The pressure-sensitive adhesive sheet with the above high tensile elastic modulus can be preferably used, for example, for purposes such as joining or fixing members. For example, in a laminate where a member and an adherend are joined via a pressure-sensitive adhesive layer, the high deformation resistance of the pressure-sensitive adhesive layer can help maintain the relative position of the member with respect to the adherend accurately. Also, for example, in a laminate where a film member and an adherend are joined via a pressure-sensitive adhesive layer, the high deformation resistance of the pressure-sensitive adhesive layer can help suppress an event where the appearance of the laminate changes due to local pressing from the film member side. In a laminate where the adherend is a rigid member having transparency (e.g., a glass member), it is particularly significant to suppress a change in the appearance visually recognized from the adherend side.

[0022] In the pressure-sensitive adhesive sheet according to some preferred embodiments, the above tensile elastic modulus may be, for example, 5.0 MPa or more, 7.0 MPa or more, 10.0 MPa or more, 15.0 MPa or more, or 20.0 MPa or more. With the increase in the above tensile elastic modulus, the deformation resistance tends to improve. The upper limit of the above tensile elastic modulus is not particularly limited. From the viewpoint of facilitating the balance with other properties (e.g., one or more properties selected from impact resistance, peel strength, haze value, etc.), it is usually advantageous that the above tensile elastic modulus is 150 MPa or less, preferably 120 MPa or less, and may be 100 MPa or less, 80 MPa or less, or 60 MPa or less. The tensile elastic modulus can be adjusted by selecting the composition of the pressure-sensitive adhesive layer, etc.

[0023] In addition, the treatment of irradiating the pressure-sensitive adhesive layer with ultraviolet rays in the above tensile test is preferably performed in a state where the pressure-sensitive adhesive layer is sandwiched between transparent release liners. As the release liner, from the viewpoint of transparency, a polyester-based resin film having at least one surface subjected to a release treatment (for example, a polyethylene terephthalate resin (PET) film subjected to a release treatment) can be preferably used. Although not particularly limited, the thickness of the release liner may be, for example, about 10 μm or more and 125 μm or less, may be 10 μm or more and 75 μm or less, or may be 20 μm or more and 50 μm or less.

[0024] The thickness of the test piece used in the above tensile test may be the same as or different from the thickness of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet disclosed herein. For example, when the thickness of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet is relatively small, for the purpose of improving operability, etc., the results obtained by performing the above tensile test using a test piece prepared to have a thickness of 5 μm or more (for example, about 5 μm to 200 μm) can be adopted as the tensile elastic modulus of the pressure-sensitive adhesive layer. The thickness of the test piece can be adjusted, for example, by appropriately overlapping the pressure-sensitive adhesive layers before ultraviolet irradiation. Also, using the same pressure-sensitive adhesive composition as that used for forming the pressure-sensitive adhesive layer to be measured, a test piece having a thickness suitable for performing the tensile test is prepared, and the results obtained by performing the above tensile test on the test piece can be adopted as the tensile elastic modulus of the pressure-sensitive adhesive layer. The above tensile test can be performed, for example, using a test piece having a thickness of about 10 μm to 50 μm (preferably about 15 μm to 25 μm).

[0025] (Impact resistance) The pressure-sensitive adhesive sheet disclosed herein has an impact resistance of 2.0 J / (10 mm) 2It is preferably as described above. The impact resistance is measured by the shear impact test described above, and more specifically, by the method described in the examples below. According to the pressure-sensitive adhesive sheet with high impact resistance, a highly reliable bond can be formed. This can be an advantageous feature, for example, in pressure-sensitive adhesive sheets used for bonding or fixing members. Such a pressure-sensitive adhesive sheet can, for example, withstand impacts such as dropping or collision and maintain a good bond between the member and the adherend even under such impacts.

[0026] In the pressure-sensitive adhesive sheet according to some preferred embodiments, the impact resistance is, for example, 2.1 J / (10 mm) 2 or more, and may be 2.3 J / (10 mm) 2 or more, and may be 2.5 J / (10 mm) 2 or more, and may be 2.7 J / (10 mm) 2 or more, and may be 3.0 J / (10 mm) 2 or more. The pressure-sensitive adhesive sheet disclosed herein may be preferably implemented in an embodiment where the impact resistance is 3.3 J / (10 mm) 2 or more or 3.5 J / (10 mm) 2 or more. The upper limit of the impact resistance is not particularly limited. From the perspective of facilitating balance with other properties, the impact resistance may be, for example, 20 J / (10 mm) 2 or less, and may be 15 J / (10 mm) 2 or less, and may be 10 J / (10 mm) 2 or less, and may be 8.0 J / (10 mm) 2 or less, and may be 6.0 J / (10 mm) 2 or less. The impact resistance can be adjusted by selecting the composition and thickness of the adhesive layer, etc.

[0027] Note that the pressure-sensitive adhesive sheet disclosed in this specification includes embodiments without limitations on the tensile elastic modulus, and in such embodiments, the pressure-sensitive adhesive sheet is not limited to those satisfying the above tensile elastic modulus. Similarly, the pressure-sensitive adhesive sheet disclosed in this specification includes embodiments without limitations on the impact resistance, and in such embodiments, the pressure-sensitive adhesive sheet is not limited to those satisfying the above impact resistance.

[0028] (Peeling Strength) The peeling strength of the pressure-sensitive adhesive sheet disclosed herein is not particularly limited and can be set according to the purpose. The above peeling strength is measured by the peeling test described above, and more specifically, it is measured by the method described in the examples below. In some embodiments, the above peeling strength may be, for example, 0.5 N / 10 mm or more, preferably 1.0 N / 10 mm or more, more preferably 1.5 N / 10 mm or more, may be 2.0 N / 10 mm or more, may be 2.2 N / 10 mm or more, and may be 2.3 N / 10 mm or more from the viewpoint of joint reliability. Also, from the viewpoint of facilitating the balance with other properties, the above peeling strength may be, for example, 10 N / 10 mm or less, may be 8.0 N / 10 mm or less, may be 6.0 N / 10 mm or less, may be 5.0 N / 10 mm or less, and may be 4.0 N / 10 mm or less. The peeling strength can be adjusted by selecting the composition, thickness, etc. of the pressure-sensitive adhesive layer.

[0029] (Haze Value) In the pressure-sensitive adhesive sheet disclosed herein, the haze value of the pressure-sensitive adhesive layer is not particularly limited. When transparency is required for the pressure-sensitive adhesive layer, the haze value of the pressure-sensitive adhesive layer may be, for example, 10% or less, may be 5.0% or less, may be 3.0% or less, and may be 1.0% or less. Non-limiting examples of usage modes where transparency is required for the pressure-sensitive adhesive layer include usage modes where a member is joined to a transparent adherend via the pressure-sensitive adhesive layer and the member is visible through the pressure-sensitive adhesive layer from the adherend side, and usage modes where a pressure-sensitive adhesive sheet having a support is joined to a transparent adherend and the support is visible through the pressure-sensitive adhesive layer from the adherend side. In some embodiments, the haze value of the pressure-sensitive adhesive layer may be less than 1.0%, may be less than 0.7%, and may be 0.5% or less (for example, 0 to 0.5%).

[0030] Here, the "haze value" refers to the ratio of the diffused transmitted light to the total transmitted light when the measurement object is irradiated with visible light. It is also called the cloudiness value. The haze value can be expressed by the following formula. Th[%]=Td / Tt×100 In the above formula, Th is the haze value [%], Td is the scattered light transmittance, and Tt is the total light transmittance.

[0031] The haze value is measured by irradiating ultraviolet rays under the conditions of an illuminance of 300 mW / cm 2 and an integrated light quantity of 3000 mJ / cm 2 and using, as a measurement sample, the adhesive layer after aging at 50°C for 48 hours, it can be measured using a haze meter (for example, "MR-100" manufactured by Murakami Color Research Laboratory). The haze value can be adjusted, for example, by selecting the composition, thickness, etc. of the adhesive layer. Note that the process of irradiating the adhesive layer with ultraviolet rays is preferably carried out in a state where the above adhesive layer is sandwiched between transparent release liners (for example, a release-treated PET film), similar to the tensile test in the measurement of the tensile modulus described above.

[0032] <Adhesive layer> The adhesive sheet in the technology disclosed herein (including the adhesive sheet, the film member with an adhesive sheet, and the method for manufacturing a laminate. The same applies hereinafter) includes an adhesive layer. The configuration of the adhesive layer can be selected so as to form a joint with high deformation resistance and high impact resistance.

[0033] (Polymer (A)) In some embodiments, the above adhesive layer contains a polymer (A). Examples of materials that can be used as the polymer (A) include polymers that exhibit rubber elasticity in the room temperature range, such as acrylic polymers, rubber polymers, polyester polymers, urethane polymers, polyether polymers, silicone polymers, polyamide polymers, fluorine polymers, etc., which are known in the field of adhesives. These can be used alone or in combination of two or more.

[0034] The weight ratio of the polymer (A) in the total weight of the adhesive layer is usually preferably 40% by weight or more, more preferably 50% by weight or more, and may be 60% by weight or more, or 70% by weight or more, from the viewpoint of impact resistance and the like. Further, the weight ratio of the polymer (A) in the total weight of the adhesive layer is typically less than 100% by weight, and from the viewpoint of facilitating adjustment of the balance of properties, it is usually advantageously 95% by weight or less, preferably 92% by weight or less, and may be 90% by weight or less, or 87% by weight or less.

[0035] As a preferred example of the polymer (A), an acrylic polymer can be mentioned. The adhesive layer in the technology disclosed herein can be an acrylic adhesive layer containing an acrylic polymer as a base polymer (the main component among the polymer components, that is, the component occupying more than 50% by weight). The acrylic polymer as the polymer (A) (hereinafter, may be referred to as "acrylic polymer (A)") is preferably an acrylic polymer composed of a monomer component containing an alkyl (meth)acrylate having a linear or branched alkyl group having 1 to 20 carbon atoms at the ester terminal in a proportion of 40% by weight or more. Hereinafter, an alkyl (meth)acrylate having an alkyl group having X or more and Y or less carbon atoms at the ester terminal may be referred to as "(meth)acrylic acid C X-Y alkyl ester".

[0036] In some embodiments, the ratio of the (meth)acrylic acid C 1-20 alkyl ester in the total monomer component of the acrylic polymer (A) is suitably more than 40% by weight, for example, may be 45% by weight or more, 50% by weight or more, 55% by weight or more, or 60% by weight or more, because it is easy to balance the properties. Among the monomer components, (meth)acrylic acid C 1-20The proportion of the alkyl ester can be 100% by weight, but usually it is suitably 98% by weight or less, for example, it may be 95% by weight or less, or may be 90% by weight or less, in order to easily achieve a balance of properties. In some embodiments, C in the total monomer components of the acrylic polymer (A) 1-20 From the viewpoint of improving the cohesiveness of the pressure-sensitive adhesive layer, the proportion of the (meth)acrylic acid alkyl ester may be, for example, 85% by weight or less, may be 80% by weight or less, may be 75% by weight or less, may be 70% by weight or less, may be 65% by weight or less, or may be 60% by weight or less.

[0037] (Meth)acrylic acid C 1-20 Non-limiting specific examples of the alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate and the like.

[0038] Among these, it is preferable to use at least the (meth)acrylic acid C 4-20 alkyl ester, and it is more preferable to use at least the (meth)acrylic acid C 4-18 alkyl ester. Particularly preferred (meth)acrylic acid C 4-18Examples of the alkyl ester include n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA). The C 4-20 Other specific examples of the alkyl ester include isononyl acrylate, n-butyl methacrylate (BMA), 2-ethylhexyl methacrylate (2EHMA), isostearyl acrylate (iSTA), and the like. These C 4-20 alkyl esters can be used alone or in combination of two or more.

[0039] The monomer component preferably contains either or both of, for example, n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA). In some embodiments, the monomer component preferably contains at least BA. Here, examples of the monomer component containing at least BA include a monomer component having a composition containing BA and not containing 2EHA, and a monomer component having a composition containing BA and 2EHA, wherein the content of 2EHA is less than the content of BA (for example, the content of 2EHA is less than 0.5 times or less than 0.3 times the content of BA).

[0040] In some embodiments, the monomer component constituting the acrylic polymer (A) may contain the C 4-18 alkyl ester of (meth)acrylic acid at a ratio of 40% by weight or more. The proportion of the C 4-18 alkyl ester of (meth)acrylic acid in the monomer component may be, for example, 50% by weight or more, 60% by weight or more, or 65% by weight or more. Also, from the viewpoint of enhancing the cohesiveness of the adhesive layer, the proportion of the C 4-18 alkyl ester of (meth)acrylic acid in the monomer component is usually suitably 99.5% by weight or less, and may be 95% by weight or less, 85% by weight or less, or 75% by weight or less.

[0041] The monomer components constituting the acrylic polymer (A) may contain, together with the (meth)acrylic acid alkyl ester, other monomers copolymerizable with the (meth)acrylic acid alkyl ester (copolymerizable monomers), if necessary. As the copolymerizable monomers, monomers having a polar group (for example, carboxy group, hydroxy group, nitrogen atom-containing ring, etc.) or monomers having a relatively high glass transition temperature of the homopolymer (for example, 10 ° C or higher) can be preferably used. Monomers having a polar group can be useful for introducing crosslinking points into the acrylic polymer (A) or increasing the cohesive force of the adhesive. The copolymerizable monomers can be used singly or in combination of two or more.

[0042] Non-limiting specific examples of the copolymerizable monomers include the following. Carboxy group-containing monomers: for example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, etc. Acid anhydride group-containing monomers: for example, maleic anhydride, itaconic anhydride. Hydroxy group-containing monomers: for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, etc., (meth)acrylic acid hydroxyalkyl. Monomers containing a sulfonic acid group or a phosphoric acid group: for example, styrene sulfonic acid, allyl sulfonic acid, sodium vinyl sulfonate, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, sulfopropyl (meth)acrylate, (meth)acryloyloxynaphthalenesulfonic acid, 2-hydroxyethylacryloyl phosphate, etc. Epoxy group-containing monomers: For example, epoxy group-containing acrylates such as glycidyl (meth)acrylate and 2-ethylglycidyl (meth)acrylate, allyl glycidyl ether, glycidyl (meth)acrylate ether, etc. Cyano group-containing monomers: For example, acrylonitrile, methacrylonitrile, etc. Isocyanate group-containing monomers: For example, 2-isocyanatoethyl (meth)acrylate, etc. Amide group-containing monomers: For example, (meth)acrylamide; N,N-dialkyl (meth)acrylamides such as N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-dipropyl (meth)acrylamide, N,N-diisopropyl (meth)acrylamide, N,N-di(n-butyl) (meth)acrylamide, N,N-di(t-butyl) (meth)acrylamide, etc.; N-alkyl (meth)acrylamides such as N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-butyl (meth)acrylamide, N-n-butyl (meth)acrylamide, etc.; N-vinyl carboxamides such as N-vinylacetamide; monomers having a hydroxyl group and an amide group, for example, N-hydroxyalkyl (meth)acrylamides such as N-(2-hydroxyethyl) (meth)acrylamide, N-(2-hydroxypropyl) (meth)acrylamide, N-(1-hydroxypropyl) (meth)acrylamide, N-(3-hydroxypropyl) (meth)acrylamide, N-(2-hydroxybutyl) (meth)acrylamide, N-(3-hydroxybutyl) (meth)acrylamide, N-(4-hydroxybutyl) (meth)acrylamide, etc.; monomers having an alkoxy group and an amide group, for example, N-alkoxyalkyl (meth)acrylamides such as N-methoxymethyl (meth)acrylamide, N-methoxyethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, etc.; and others, such as N,N-dimethylaminopropyl (meth)acrylamide, N-(meth)acryloylmorpholine, etc. Amino group-containing monomers: for example, aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate. Epoxy group-containing monomers: for example, glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, allyl glycidyl ether. Monomers having a nitrogen atom-containing ring: for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyl oxazole, N-(meth)acryloyl-2-pyrrolidone, N-(meth)acryloylpiperidine, N-(meth)acryloylpyrrolidine, N-(meth)acryloylmorpholine, N-vinylmorpholine, N-vinyl-3-morpholinone, N-vinyl-2-caprolactam, N-vinyl-1,3-oxazine-2-one, N-vinyl-3,5-morpholinedione, N-vinylpyrazole, N-vinylisoxazole, N-vinylthiazole, N-vinylisothiazole, N-vinylpyridazine, etc. (for example, lactams such as N-vinyl-2-caprolactam). Monomers having a succinimide skeleton: for example, N-(meth)acryloyloxymethylene succinimide, N-(meth)acryloyl-6-oxyhexamethylene succinimide, N-(meth)acryloyl-8-oxyhexamethylene succinimide, etc. Maleimides: for example, N-cyclohexyl maleimide, N-isopropyl maleimide, N-lauryl maleimide, N-phenyl maleimide, etc. Itaconimides: for example, N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itaconimide, N-cyclohexyl itaconimide, N-lauryl itaconimide, etc. (Meth)acrylic acid aminoalkyls: For example, aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate. Alkoxy group-containing monomers: For example, alkoxyalkyl (meth)acrylates such as 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, propoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxypropyl (meth)acrylate; alkoxyalkylene glycol (meth)acrylates such as methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate (for example, alkoxypolyalkylene glycol (meth)acrylate). Alkoxysilyl group-containing monomers: For example, alkoxysilyl group-containing (meth)acrylates such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, and alkoxysilyl group-containing vinyl compounds such as vinyltrimethoxysilane, vinyltriethoxysilane. Vinyl esters: For example, vinyl acetate, vinyl propionate, etc. Vinyl ethers: For example, vinyl alkyl ethers such as methyl vinyl ether and ethyl vinyl ether. Aromatic vinyl compounds: For example, styrene, α-methylstyrene, vinyltoluene, etc. Olefins: For example, ethylene, butadiene, isoprene, isobutylene, etc. Alkyl (meth)acrylates having an alicyclic hydrocarbon group: For example, alicyclic hydrocarbon group-containing (meth)acrylates such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate. (Meth)acrylate having an aromatic hydrocarbon group: for example, aromatic hydrocarbon group-containing (meth)acrylates such as phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, etc. In addition, heterocyclic ring-containing (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate, halogen atom-containing (meth)acrylates such as vinyl chloride and fluorine atom-containing (meth)acrylates, silicon atom-containing (meth)acrylates such as silicone (meth)acrylate, (meth)acrylates obtained from terpene compound derivative alcohols, etc.

[0043] When using such a copolymerizable monomer, its usage amount is not particularly limited, but usually it is appropriate to be 0.01% by weight or more of the total monomer component. From the viewpoint of more effectively exerting the effect of the copolymerizable monomer, the usage amount of the copolymerizable monomer may be 0.1% by weight or more of the total monomer component, or may be 0.5% by weight or more. Also, from the viewpoint of easily achieving a balance in adhesive properties, the usage amount of the copolymerizable monomer is usually appropriately 50% by weight or less of the total monomer component, and preferably 40% by weight or less.

[0044] In some embodiments, the monomer component constituting the acrylic polymer (A) may include a monomer having a nitrogen atom. By using a monomer having a nitrogen atom, the cohesive force of the adhesive can be increased, and the peel strength after photocuring can be preferably improved. As a preferred example of the monomer having a nitrogen atom, a monomer having a nitrogen atom-containing ring can be mentioned. As the monomer having a nitrogen atom-containing ring, those exemplified above can be used, for example, general formula (1):

Chemical formula

[0045] The usage amount of the monomer having a nitrogen atom (preferably a monomer having a nitrogen atom-containing ring) is not particularly limited, and may be, for example, 1% by weight or more of the total monomer component, 3% by weight or more, and further may be 5% by weight or more or 7% by weight or more. In one aspect, the usage amount of the monomer having a nitrogen atom may be 10% by weight or more, 15% by weight or more, or 20% by weight or more of the total monomer component. Also, the usage amount of the monomer having a nitrogen atom is suitably, for example, 40% by weight or less of the total monomer component, may be 35% by weight or less, 30% by weight or less, or 25% by weight or less. In another aspect, the usage amount of the monomer having a nitrogen atom may be, for example, 20% by weight or less, 15% by weight or less, or 10% by weight or less of the total monomer component.

[0046] In some aspects, the monomer component constituting the acrylic polymer (A) may include a hydroxyl group-containing monomer. By using the hydroxyl group-containing monomer, the cohesive force and the degree of crosslinking (for example, crosslinking with an isocyanate crosslinking agent) of the adhesive can be suitably adjusted. The usage amount when using the hydroxyl group-containing monomer is not particularly limited, and may be, for example, 0.01% by weight or more of the total monomer component, 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more, 5% by weight or more, or 10% by weight or more. Also, from the viewpoint of suppressing the water absorption of the adhesive layer, in some aspects, the usage amount of the hydroxyl group-containing monomer is suitably, for example, 40% by weight or less of the total monomer component, may be 30% by weight or less, 25% by weight or less, or 20% by weight or less. In another aspect, the usage amount of the hydroxyl group-containing monomer may be, for example, 15% by weight or less, 10% by weight or less, or 5% by weight or less of the total monomer component.

[0047] In some embodiments, the proportion of the carboxy group-containing monomer in the monomer component of the acrylic polymer (A) may be, for example, 2% by weight or less, may be 1% by weight or less, or may be 0.5% by weight or less (for example, less than 0.1% by weight). It is not necessary to substantially use a carboxy group-containing monomer as the monomer component of the acrylic polymer (A). Here, not substantially using a carboxy group-containing monomer means not using a carboxy group-containing monomer at least intentionally. The pressure-sensitive adhesive layer containing the acrylic polymer (A) with the amount of the carboxy group-containing monomer restricted as described above is preferable from the viewpoint of preventing metal corrosion. The pressure-sensitive adhesive sheet having such a pressure-sensitive adhesive layer can be preferably used, for example, in a mode where the pressure-sensitive adhesive layer is in contact with an adherend having a metal material and / or a support (which can be a metal foil or a support film containing a metal material).

[0048] In some embodiments, the monomer component constituting the acrylic polymer (A) may include an alicyclic hydrocarbon group-containing (meth)acrylate. Thereby, the cohesive force of the pressure-sensitive adhesive can be increased, and the peel strength after photocuring can be improved. As the alicyclic hydrocarbon group-containing (meth)acrylate, those exemplified above and the like can be used, and for example, cyclohexyl acrylate or isobornyl acrylate can be preferably employed. The amount used when using an alicyclic hydrocarbon group-containing (meth)acrylate is not particularly limited, and can be, for example, 1% by weight or more, 3% by weight or more, or 5% by weight or more of the total monomer component. In one embodiment, the amount used of the alicyclic hydrocarbon group-containing (meth)acrylate may be 10% by weight or more, or 15% by weight or more of the total monomer component. The upper limit of the amount used of the alicyclic hydrocarbon group-containing (meth)acrylate is suitably about 40% by weight or less, and may be, for example, 30% by weight or less, or 25% by weight or less (for example, 15% by weight or less, and further 10% by weight or less).

[0049] The polymerization method for forming (synthesizing) the polymer (A) from the monomer components is not particularly limited, and various conventionally known polymerization methods can be appropriately employed. For example, thermal polymerization such as solution polymerization, emulsion polymerization, bulk polymerization, etc. (typically carried out in the presence of a thermal polymerization initiator); photopolymerization carried out by irradiating light such as ultraviolet rays (typically carried out in the presence of a photopolymerization initiator); radiation polymerization carried out by irradiating radiation such as beta rays, gamma rays, etc.; and the like, can be appropriately adopted. Two or more polymerization methods may be combined (for example, stepwise) and carried out.

[0050] As the solvent (polymerization solvent) for solution polymerization, for example, aromatic compounds such as toluene (typically aromatic hydrocarbons); esters such as ethyl acetate and butyl acetate; aliphatic or alicyclic hydrocarbons such as hexane and cyclohexane; halogenated alkanes such as 1,2-dichloroethane; lower alcohols such as isopropyl alcohol (for example, monohydric alcohols having 1 to 4 carbon atoms); ethers such as tert-butyl methyl ether; ketones such as methyl ethyl ketone; etc., any one kind of solvent selected therefrom, or a mixed solvent of two or more kinds can be used.

[0051] In the polymerization, known or commonly used thermal polymerization initiators and photopolymerization initiators can be used according to the polymerization method, polymerization mode, etc. Such polymerization initiators can be used singly or in appropriate combinations of two or more kinds.

[0052] As the thermal polymerization initiator, there is no particular limitation, and for example, azo polymerization initiators, peroxide initiators, redox initiators by a combination of a peroxide and a reducing agent, substituted ethane initiators, etc. can be used. More specifically, for example, azo initiators such as 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2-methylpropionamidine) disulfate, 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis(N,N'-dimethylenebisobutylamidine), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate; peroxides such as potassium persulfate, ammonium persulfate; peroxide initiators such as benzoyl peroxide, t-butyl hydroperoxide, hydrogen peroxide; substituted ethane initiators such as phenyl-substituted ethane; redox initiators such as a combination of persulfate and sodium bisulfite, a combination of peroxide and sodium ascorbate; etc. are exemplified, but not limited thereto. Thermal polymerization can be preferably carried out at a temperature of about 20 to 100 °C (typically 40 to 80 °C), but is not limited thereto.

[0053] As the photoinitiator, there is no particular limitation, and for example, ketal photoinitiators, acetophenone photoinitiators, benzoin ether photoinitiators, acylphosphine oxide photoinitiators, α-ketol photoinitiators, aromatic sulfonyl chloride photoinitiators, photoactive oxime photoinitiators, benzoin photoinitiators, benzyl photoinitiators, benzophenone photoinitiators, thioxanthone photoinitiators, etc. can be used.

[0054] The amount of the polymerization initiator used can be the normal amount according to the polymerization method, polymerization mode, etc., and is not particularly limited. 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 with respect to 100 parts by weight of the monomer to be polymerized.

[0055] For the above polymerization, various conventionally known chain transfer agents (which can also be understood as molecular weight regulators or polymerization degree regulators) can be used as necessary. As the chain transfer agent, mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan, thioglycolic acid, and α-thioglycerol can be used. Alternatively, a chain transfer agent that does not contain a sulfur atom (non-sulfur-based chain transfer agent) may be used. Specific examples of the non-sulfur-based chain transfer agent include anilines such as N,N-dimethylaniline and N,N-diethylaniline; terpenoids such as α-pinene and terpinolene; styrenes such as α-methylstyrene and α-methylstyrene dimer; compounds having a benzylidene group such as dibenzylideneacetone, cinnamyl alcohol, and cinnamaldehyde; hydroquinones such as hydroquinone and naphthohydroquinone; quinones such as benzoquinone and naphthoquinone; olefins such as 2,3-dimethyl-2-butene and 1,5-cyclooctadiene; alcohols such as phenol, benzyl alcohol, and allyl alcohol; benzyl hydrogens such as diphenylbenzene and triphenylbenzene; etc. The chain transfer agent can be used alone or in combination of two or more. Note that the technology disclosed herein can also be preferably implemented in a mode without using a chain transfer agent.

[0056] When using a chain transfer agent, the amount used can be, for example, about 0.005 parts by weight to 1 part by weight with respect to 100 parts by weight of the monomer component. In some embodiments, from the perspective of impact resistance, the amount of the chain transfer agent used with respect to 100 parts by weight of the monomer component can be, for example, 0.01 part by weight or more, and can also be 0.03 part by weight or more, 0.05 part by weight or more, or 0.07 part by weight or more. Also, in some embodiments, from the perspective of deformation resistance, the amount of the chain transfer agent used with respect to 100 parts by weight of the monomer component can be, for example, 0.5 part by weight or less, and can also be 0.2 part by weight or less, 0.1 part by weight or less, or less than 0.1 part by weight (for example, 0.09 part by weight or less).

[0057] In the technology disclosed herein, the glass transition temperature (Tg) of the polymer (A) is not particularly limited, but is usually preferably less than 0 °C, more preferably less than -10 °C, and even more preferably less than -20 °C. With a decrease in the Tg of the polymer (A), the impact resistance tends to improve. In some embodiments, the Tg of the polymer (A) may be less than -25 °C or less than -30 °C. Also, the Tg of the polymer (A) is typically -80 °C or higher, and may be, for example, -70 °C or higher, -60 °C or higher, or -55 °C or higher. From the viewpoint of increasing the tensile modulus, in some embodiments, the Tg of the polymer (A) is preferably -50 °C or higher, more preferably -45 °C or higher, and may be -40 °C or higher, -38 °C or higher, or -35 °C or higher.

[0058] Here, in this specification, the Tg of a polymer refers to the Tg determined by Fox's equation based on the composition of the monomer components used in the preparation of the polymer. Fox's equation is, as shown below, a relational equation between the Tg of a copolymer and the glass transition temperatures Tgi of the homopolymers obtained by homopolymerizing each of the monomers constituting the copolymer. 1 / Tg = Σ(Wi / Tgi)

[0059] In the above Fox's equation, Tg represents the glass transition temperature of the copolymer (unit: K), Wi represents the weight fraction of monomer i in the copolymer (copolymerization ratio based on weight), and Tgi represents the glass transition temperature of the homopolymer of monomer i (unit: K). When the polymer targeted for the determination of Tg is a homopolymer, the Tg of the homopolymer coincides with the Tg of the targeted polymer.

[0060] As the glass transition temperature of the homopolymer used for calculating Tg, the values described in known materials shall be used. For example, for the monomers listed below, the following values are used as the glass transition temperatures of the homopolymers of the monomers. n-butyl acrylate -55 °C isostearyl acrylate -18 °C cyclohexyl acrylate 15 °C N-vinyl-2-pyrrolidone at 54 °C 4-hydroxybutyl acrylate at -40 °C

[0061] Regarding the glass transition temperature 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. When multiple types of values are described in this literature, the highest value shall be adopted.

[0062] The weight average molecular weight (Mw) of polymer (A) is not particularly limited. From the viewpoint of achieving a good balance between deformation resistance and impact resistance, in some embodiments, the Mw of polymer (A) is, for example, approximately 10×10 4 or more, preferably 20×10 4 or more, more preferably 30×10 4 or more, even more preferably 40×10 4 or more, and even more preferably 50×10 4 or more. Also, the upper limit of the Mw of polymer (A) can usually be approximately 500×10 4 or less. From the viewpoint of adhesion and peel strength to the adherend, in some embodiments, the Mw of polymer (A) can be, for example, 150×10 4 or less, may be 100×10 4 or less, may be 90×10 4 or less, may be 75×10 4 or less. Here, Mw refers to the value in terms of standard polystyrene obtained by gel permeation chromatography (GPC). As the GPC device, for example, the model name "HLC-8320GPC" (column: TSKgel GMH-H(S), manufactured by Tosoh Corporation) may be used. The same applies to the examples described later. The above examples of Mw may be applied to the Mw of polymer (A) in the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet disclosed herein, or may be applied to the Mw of polymer (A) in the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer.

[0063] (Photoreactive monomer (B)) In the technology disclosed herein, the adhesive layer may contain a photoreactive monomer (B) in addition to the polymer (A) as described above (for example, acrylic polymer (A)). As the photoreactive monomer (B), a compound having 2 or more ethylenically unsaturated groups (hereinafter also referred to as "number of functional groups") contained in the molecule can be used. The upper limit of the number of functional groups of the compound used as the photoreactive monomer (B) is not particularly limited. The number of functional groups may be, for example, 50 or less, 40 or less, 30 or less, 20 or less, or 15 or less. In some embodiments, a compound having ethylenically unsaturated groups with a functional group number of, for example, 2 to 10 can be used, a compound having a functional group number of 2 to 8 is preferably used, and a compound having a functional group number of 2 to 6 is more preferably used. The photoreactive monomer (B) can be used alone or in combination of two or more.

[0064] The photoreactive monomer (B) contained in the adhesive layer can form a crosslinked structure by reacting the above-mentioned ethylenically unsaturated groups by irradiation with light (for example, ultraviolet light) or the like after being attached to the adherend. An adhesive sheet containing the photoreactive monomer (B) in the adhesive layer can enhance the deformation resistance of the adhesive layer by performing ultraviolet irradiation or the like after being attached to the adherend to cure the adhesive layer. Thereby, good followability to the surface shape of the adherend at the time of attachment to the adherend and high deformation resistance after attachment can be preferably achieved both at the same time.

[0065] Examples of the above-mentioned ethylenically unsaturated groups include, but are not limited to, acryloyl group, methacryloyl group, vinyl group, and allyl group. The two or more ethylenically unsaturated groups that the photoreactive monomer (B) has in the molecule may be the same group as each other, or may be two or more different groups. Examples of the ethylenically unsaturated groups preferable from the viewpoint of photoreactivity include acryloyl group and methacryloyl group. Among them, acryloyl group is preferable.

[0066] The functional group equivalent of the compound used as the photoreactive monomer (B) is not particularly limited. The above functional group equivalent may be, for example, about 50 to 10,000 g / mol, may be about 50 to 8,000 g / mol, may be about 50 to 5,000 g / mol, may be about 50 to 3,000 g / mol, or may be about 50 to 2,000 g / mol. In some embodiments, as the photoreactive monomer (B), a compound having a functional group equivalent of about 60 to 800 g / mol (more preferably about 80 to 600 g / mol) can be preferably used from the viewpoint of photocurability.

[0067] Note that the functional group equivalent of the photoreactive monomer (B) is calculated by dividing the molecular weight [g / mol] of the photoreactive monomer (B) by the number of ethylenically unsaturated functional groups possessed by the photoreactive monomer (B). The molecular weight of the photoreactive monomer (B) can be obtained, for example, as the weight average molecular weight in terms of standard polystyrene by the gel permeation chromatography (GPC) method. Also, as the molecular weight [g / mol] of the photoreactive monomer (B), the molecular weight calculated from the manufacturer's nominal value or the molecular structure may be adopted.

[0068] The molecular weight of the photoreactive monomer (B) is not particularly limited and can be selected so that the desired effect is preferably exhibited. For example, as the photoreactive monomer (B), those having a molecular weight of approximately 20,000 or less can be used. From the viewpoints of ease of preparation and coatability of the pressure-sensitive adhesive composition, in some embodiments, the molecular weight of the photoreactive monomer (B) may be, for example, 16,000 or less, may be 10,000 or less, may be 4,000 or less, may be 1,500 or less, or may be 1,000 or less. The molecular weight of the photoreactive monomer (B) is, for example, 100 or more, and typically 120 or more. From the viewpoints of processability and handleability of the pressure-sensitive adhesive sheet, in some embodiments, the molecular weight of the photoreactive monomer (B) may be, for example, 150 or more, may be 200 or more, may be 280 or more, may be 350 or more, may be 420 or more, may be 480 or more, or may be 550 or more.

[0069] In the pressure-sensitive adhesive sheet disclosed herein, the amount of the photoreactive monomer (B) contained in the pressure-sensitive adhesive layer is not particularly limited and can be appropriately set according to the target performance (for example, the tensile elastic modulus of the pressure-sensitive adhesive layer after photocuring). In some embodiments where the pressure-sensitive adhesive layer contains the polymer (A) and the photoreactive monomer (B), the amount of the photoreactive monomer (B) relative to 100 parts by weight of the polymer (A) contained in the pressure-sensitive adhesive layer may be, for example, 1 part by weight or more, and usually it is appropriate to be 3 parts by weight or more. From the viewpoint of facilitating an increase in the tensile elastic modulus of the pressure-sensitive adhesive layer after photocuring, the amount of the photoreactive monomer (B) relative to 100 parts by weight of the polymer (A) may be 5 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, or 20 parts by weight or more. Further, from the viewpoints of the cohesiveness of the pressure-sensitive adhesive layer before photocuring and the handleability (for example, processability) of the pressure-sensitive adhesive sheet, the amount of the photoreactive monomer (B) relative to 100 parts by weight of the polymer (A) is usually appropriately 80 parts by weight or less, preferably 60 parts by weight or less, and may be 50 parts by weight or less, 40 parts by weight or less, or 35 parts by weight or less.

[0070] In some embodiments, it is preferable that the pressure-sensitive adhesive layer contains at least compound B1 having a ring structure and two or more ethylenically unsaturated groups in the molecule as the photoreactive monomer (B). According to the pressure-sensitive adhesive layer containing a compound B1 having such a structure, the deformation resistance of the pressure-sensitive adhesive layer can be effectively enhanced by light irradiation. The ring in the ring structure may be an aliphatic ring or an aromatic ring. Further, the ring may be a carbocyclic ring or a heterocyclic ring. The number of rings contained in one molecule of compound B1 may be 1 or 2 or more. The upper limit of the number of rings contained in compound B1 is not particularly limited, and may be, for example, 100 or less, 70 or less, 50 or less, 30 or less, 15 or less, 8 or less, 6 or less, 5 or less, 4 or less. When compound B1 contains two or more rings, those rings may or may not form a condensed ring (typically a bicyclic or tricyclic condensed ring) by one or two or more rings. The ring is preferably contained in the main chain of compound B1. That is, it is preferable that one ethylenically unsaturated group and at least one other ethylenically unsaturated group of compound B1 are linked via the ring structure. Compound B1 can be used alone or in combination of two or more kinds.

[0071] As the compound B1, a compound having a ring structure and two or more ethylenically unsaturated groups in the molecule and a functional group equivalent of 100 g / mol or more can be preferably used. According to the pressure-sensitive adhesive sheet containing the compound B1 satisfying the above functional group equivalent in the pressure-sensitive adhesive layer, a joint having high deformation resistance and high impact resistance can be preferably formed. The reason for obtaining such an effect is not particularly limitedly interpreted, but according to the compound B1, the rigidity of the ring structure can effectively increase the tensile elastic modulus of the pressure-sensitive adhesive layer after light irradiation to impart deformation resistance, while the functional group equivalent of the compound B1 is above a predetermined value, which is considered to be able to maintain the distance between crosslinking points and form a crosslinked structure with high resistance to impact. In some embodiments, the functional group equivalent of the compound B1 may be, for example, 120 g / mol or more, 150 g / mol or more, 180 g / mol or more, 230 g / mol or more, 280 g / mol or more, 320 g / mol or more, or 350 g / mol or more. With the increase in the functional group equivalent of the compound B1, the impact resistance tends to improve. Also, the functional group equivalent of the compound B1 may be, for example, 10000 g / mol or less, 8000 g / mol or less, 5000 g / mol or less, 3000 g / mol, or 2000 g / mol or less. In some embodiments, from the viewpoint of photocurability and the like, the functional group equivalent of the compound B1 is preferably 800 g / mol or less, and more preferably 600 g / mol or less. In some embodiments, the functional group equivalent of the compound B1 may be 500 g / mol or less, 400 g / mol or less, or 300 g / mol or less.

[0072] In some embodiments, the number of functional groups of the compound B1 (that is, the number of ethylenically unsaturated groups contained in the molecule) may be, for example, 2 to 50, 2 to 40, 2 to 30, 2 to 10, preferably 2 to 6, 2 to 4, or 2 to 3. In some embodiments, the compound B1 having 2 functional groups can be preferably employed.

[0073] Compound B1 may have a functional group other than an ethylenically unsaturated group. Examples of the functional group other than an ethylenically unsaturated group include a hydroxyl group, a carboxy group, an amino group, etc. Preferable examples of the functional group other than an ethylenically unsaturated group include a hydroxyl group and an amino group.

[0074] Examples of Compound B1 include bisphenol A type epoxy (meth)acrylates such as bisphenol A glycidyl ether (meth)acrylic acid adducts, bisphenol A glycidyl amine (meth)acrylic acid adducts, and bisphenol A glycidyl ester (meth)acrylic acid adducts; alkylene oxide modified bisphenol A (meth)acrylates such as ethylene oxide (EO) modified bisphenol A di(meth)acrylate and propylene oxide (PO) modified bisphenol A di(meth)acrylate; bisphenol F type epoxy (meth)acrylates such as bisphenol F glycidyl ether (meth)acrylic acid adducts, bisphenol F glycidyl amine (meth)acrylic acid adducts, and bisphenol F glycidyl ester (meth)acrylic acid adducts; alkylene oxide modified bisphenol F (meth)acrylates such as EO modified bisphenol F di(meth)acrylate and PO modified bisphenol F di(meth)acrylate; bisphenol E type epoxy (meth)acrylates such as bisphenol E glycidyl ether (meth)acrylic acid adducts, bisphenol E glycidyl amine (meth)acrylic acid adducts, and bisphenol E glycidyl ester (meth)acrylic acid adducts; alkylene oxide modified bisphenol E (meth)acrylates such as EO modified bisphenol E di(meth)acrylate and PO modified bisphenol E di(meth)acrylate; (meth)acrylates containing a fluorene skeleton such as 9,9-bis(4-hydroxyphenyl)fluorene di(meth)acrylate and 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene di(meth)acrylate; alicyclic rings (which may be alicyclic condensed rings), such as tricyclodecane dimethanol di(meth)acrylate, hydrogenated bisphenol A type epoxy (meth)acrylate, hydrogenated bisphenol F type epoxy (meth)acrylate, hydrogenated bisphenol E type epoxy (meth)acrylate, hydrogenated phthalic acid type epoxy (meth)acrylate, hydrogenated terpene phenol (meth)acrylate, and 1,4-cyclohexane dimethanol diglycidyl ether (meth)acrylate.(Meth)acrylates having the following; (meth)acrylic acid adducts of novolak type epoxy resins; (meth)acrylic acid adducts of thioether type epoxy resins; (meth)acrylic acid adducts of naphthalene type epoxy resins; (meth)acrylic acid adducts of dicyclopentadiene type epoxy resins; (meth)acrylic acid adducts of alkyldiphenol type epoxy resins; (meth)acrylic acid adducts of biphenyl type epoxy resins; (meth)acrylic acid adducts of terpene phenol resins; isocyanurate type (meth)acrylates such as tris(2-hydroxyethyl)isocyanurate di(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate; divinylbenzene; hydroquinone di(meth)acrylate; resorcin di(meth)acrylate; modified products of any of the above materials (for example, amine-modified products, acid-modified products, halogen-modified products); etc. are mentioned, but not limited thereto. In some embodiments, a compound B1 having an aromatic carbon ring may be preferably employed. Preferable examples of the compound B1 include compounds containing a bisphenol A structure such as bisphenol A type epoxy (meth)acrylate, alkylene oxide-modified bisphenol A (meth)acrylate, and their modified products (for example, amine-modified products).

[0075] Commercially available products that can be used as the compound B1 include, but are not limited to, products named "A-DCP", "A-BPE-4" manufactured by Shin-Nakamura Chemical Co., Ltd., products named "Biscote #540", "Biscote #700HV" manufactured by Osaka Organic Chemical Industry Co., Ltd., "R-114F" manufactured by Nippon Kayaku Co., Ltd., products named "Epoxy Ester 3000A", "Epoxy Ester 80MFA" manufactured by Kyoeisha Chemical Co., Ltd., products named "EBECRYL 3700", "EBECRYL 3703", "EBECRYL 3603" manufactured by Daicel Ornex Co., Ltd., etc.

[0076] The amount of Compound B1 relative to 100 parts by weight of the polymer (A) contained in the adhesive layer is not particularly limited, and can be, for example, 0.5 part by weight or more. From the perspective of easily obtaining an adhesive layer that balances deformation resistance and impact resistance, in some embodiments, the amount of Compound B1 relative to 100 parts by weight of the polymer (A) may be, for example, 1 part by weight or more, 3 parts by weight or more, 5 parts by weight or more, 7 parts by weight or more, 10 parts by weight or more, or 15 parts by weight or more. Also, from the perspective of the cohesiveness of the adhesive layer before photocuring and the handleability of the adhesive sheet, the amount of Compound B1 relative to 100 parts by weight of the polymer (A) is usually suitably 80 parts by weight or less, preferably 60 parts by weight or less, and may be 50 parts by weight or less, 40 parts by weight or less, or 35 parts by weight or less.

[0077] In some embodiments, the above adhesive layer may contain, as the above photoreactive monomer (B), a Compound B2 having 2 or more functional groups and no ring structure in the molecule. Compound B2 is preferably used in combination with Compound B1. Thereby, the crosslinked structure of the adhesive layer can be adjusted, and a joint that more suitably balances deformation resistance and impact resistance can be formed. Compound B2 can be used alone or in combination of two or more.

[0078] The number of functional groups of Compound B2 may be, for example, 50 or less, 40 or less, 30 or less, 20 or less, or 15 or less. In some embodiments, the number of functional groups of Compound B2 used may be, for example, 2 to 10, preferably 3 to 10, may be 3 to 8, or may be 4 to 6. For example, in an embodiment where a compound having 2 functional groups is used as Compound B1, it may be advantageous to use Compound B2 having 3 or more (preferably 4 or more, more preferably 5 or more, and even more preferably 6 or more) functional groups.

[0079] The functional group equivalent of compound B2 is not particularly limited and may be, for example, 5000 g / mol or less, may be 2000 g / mol or less, or may be 1000 g / mol or less. In some embodiments, the functional group equivalent of compound B2 may be, for example, 600 g / mol or less, may be 400 g / mol or less, 300 g / mol or less, 200 g / mol or less, 150 g / mol or less, or 100 g / mol or less from the viewpoints of photocurability and improvement in the hardness of the cured product. The functional group equivalent of compound B2 is typically 50 g / mol or more, preferably 60 g / mol or more, and may be 70 g / mol or more, 80 g / mol or more, or 90 g / mol or more.

[0080] Examples of compounds that can be used as compound B2 include pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, trimethylolethane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, pentaerythritol di(meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate, EO-modified products or PO-modified products of any of the above-mentioned materials, etc., but are not limited thereto.

[0081] In the embodiment using Compound B2, the amount of Compound B2 relative to 100 parts by weight of the polymer (A) contained in the pressure-sensitive adhesive layer is not particularly limited, and can be, for example, 0.1 part by weight or more. From the viewpoint of easily obtaining a pressure-sensitive adhesive layer that achieves a good balance between deformation resistance and impact resistance, in some embodiments, the amount of Compound B2 relative to 100 parts by weight of the polymer (A) can be, for example, 1 part by weight or more, 2 parts by weight or more, 4 parts by weight or more, 6 parts by weight or more, 10 parts by weight or more, or 12 parts by weight or more. Also, from the viewpoint of suppressing a decrease in adhesion to the adherend due to excessive crosslinking, in some embodiments, it is appropriate that the amount of Compound B2 relative to 100 parts by weight of the polymer (A) is, for example, 25 parts by weight or less, preferably 17 parts by weight or less, and may also be 15 parts by weight or less, 13 parts by weight or less, or 9 parts by weight or less.

[0082] In the embodiment of using Compound B1 and Compound B2 in combination, as Compound B2, a compound having 3 or more functional groups and a smaller functional group equivalent than the functional group equivalent of Compound B1 used in combination therewith can preferably be employed. In some embodiments, the ratio (FE2 / FE1) of the functional group equivalent FE2 of Compound B2 to the functional group equivalent FE1 of Compound B1 can be, for example, 0.9 or less, 0.7 or less, 0.5 or less, or 0.4 or less. According to such an embodiment, the effect of improving the tensile elastic modulus by the photoreactive monomer (B) can be efficiently exerted. The lower limit of the above ratio (FE2 / FE1) is not particularly limited and can be, for example, 0.01 or more, 0.1 or more, or 0.2 or more.

[0083] In the embodiment of using Compound B1 and Compound B2 in combination, the weight ratio (W2 / W1) of the amount of use W2 of Compound B2 to the amount of use W1 of Compound B1 is not particularly limited. In some embodiments, the above weight ratio (W2 / W1) can be, for example, 0.05 to 10, 0.1 to 5, 0.2 to 3, or 0.3 to 2. By setting the weight ratio (W2 / W1) within any of the above-mentioned ranges, the effect of using Compound B1 and Compound B2 in combination tends to be preferably exerted.

[0084] In some embodiments of the pressure-sensitive adhesive sheet disclosed herein, the photoreactive monomer (B) can be contained in the pressure-sensitive adhesive layer in a free form. Such a pressure-sensitive adhesive layer can be preferably formed using a pressure-sensitive adhesive composition containing the photoreactive monomer (B) in a free form. Here, the "free form" means that the photoreactive monomer (B) is not chemically bonded to other components (e.g., the polymer (A)) contained in the pressure-sensitive adhesive layer or the pressure-sensitive adhesive composition. A pressure-sensitive adhesive composition containing the photoreactive monomer (B) in a free form can be advantageous from the viewpoints of ease of preparation and suppression of gelation.

[0085] In some other forms of the pressure-sensitive adhesive sheet disclosed herein, at least a part of the photoreactive monomer (B) can be contained in the pressure-sensitive adhesive layer in a form chemically bonded to other components (e.g., the polymer (A), a crosslinking agent described later, etc.) contained in the pressure-sensitive adhesive layer or the pressure-sensitive adhesive composition, from the viewpoint of improving the processability of the pressure-sensitive adhesive sheet and the like. The above chemical bond can be, for example, a bond formed by the reaction between a functional group F1 other than the ethylenically unsaturated group that the photoreactive monomer (B) has in the molecule and a functional group that the above other component has in the molecule and that is reactive with the functional group F1. The above other component may be a crosslinking agent, and the photoreactive monomer (B) may be bonded to the polymer (A) via the crosslinking agent.

[0086] (Acrylic oligomer) In the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet disclosed herein, an acrylic oligomer can be contained from the viewpoints of improving the cohesive force and improving the adhesiveness to a surface adjacent to the pressure-sensitive adhesive layer (e.g., the surface of the support in the pressure-sensitive adhesive sheet, the surface of the adherend to which the pressure-sensitive adhesive sheet is adhered, etc.). A pressure-sensitive adhesive layer containing an acrylic oligomer can be preferably formed using a pressure-sensitive adhesive composition containing the acrylic oligomer. As the acrylic oligomer, those having a higher Tg than the Tg of the polymer (A) described above can be preferably employed.

[0087] The Tg of the above acrylic oligomer is not particularly limited and can be, for example, about 20°C or higher and 300°C or lower. The above Tg may be, for example, about 30°C or higher, about 40°C or higher, about 60°C or higher, about 80°C or higher, or about 100°C or higher. When the Tg of the acrylic oligomer increases, the effect of improving the cohesive force generally tends to increase. Further, from the viewpoints of the anchoring property to the support and the shock absorption property, etc., the Tg of the acrylic oligomer may be, for example, about 250°C or lower, about 200°C or lower, about 180°C or lower, or about 150°C or lower. Note that the Tg of the acrylic oligomer is a value calculated based on Fox's equation, similar to the Tg of polymer (A).

[0088] The Mw of the acrylic oligomer is not particularly limited and can be, for example, approximately 1000 or higher, and usually it is appropriate that it is approximately 1500 or higher, and it may be approximately 2000 or higher, or approximately 3000 or higher. Also, the Mw of the acrylic oligomer may be, for example, less than approximately 30000, and usually it is appropriate that it is less than approximately 10000, and it may be less than approximately 7000, or less than approximately 5000. When the Mw is within the above range, the effect of improving the cohesiveness of the adhesive layer and the adhesiveness to the adjacent surface is preferably easily exerted. The Mw of the acrylic oligomer can be measured by gel permeation chromatography (GPC) and obtained as a value in terms of standard polystyrene. Specifically, for example, it can be measured under the conditions of a flow rate of about 0.5 mL / min in a tetrahydrofuran solvent using two TSKgel GMH-H(20) columns on HPLC8020 manufactured by Tosoh Corporation.

[0089] Examples of the monomer components constituting the acrylic oligomer include the various (meth)acrylic acid C 1-20 alkyl esters; the various alicyclic hydrocarbon group-containing (meth)acrylates described above; the various aromatic hydrocarbon group-containing (meth)acrylates described above; (meth)acrylates obtained from terpene compound derivatives of alcohol; and the like (meth)acrylate monomers can be mentioned. These can be used alone or in combination of two or more.

[0090] It is preferable from the viewpoint of improving adhesiveness that the acrylic oligomer contains, as monomer units, acrylic monomers having a relatively bulky structure typified by alkyl (meth)acrylates having a branched alkyl group such as isobutyl (meth)acrylate and t-butyl (meth)acrylate; (meth)acrylates containing an alicyclic hydrocarbon group and (meth)acrylates containing an aromatic hydrocarbon group; and the like. Further, when ultraviolet rays are employed during the synthesis of the acrylic oligomer or during the production of the pressure-sensitive adhesive layer, monomers having a saturated hydrocarbon group at the ester terminal are preferable in that they are less likely to cause polymerization inhibition. For example, alkyl (meth)acrylates having a branched alkyl group and (meth)acrylates containing a saturated alicyclic hydrocarbon group can be suitably used.

[0091] The proportion of the (meth)acrylate monomer in all the monomer components constituting the acrylic oligomer is typically more than 50% by weight, preferably 60% by weight or more, more preferably 70% by weight or more (for example, 80% by weight or more, still more preferably 90% by weight or more). In a preferred embodiment, the acrylic oligomer has a monomer composition consisting essentially of only one or more (meth)acrylate monomers. For example, when the monomer components constituting the acrylic oligomer include a (meth)acrylate containing an alicyclic hydrocarbon group and a C 1-20 alkyl ester of (meth)acrylic acid, their weight ratio is not particularly limited. In some embodiments, the weight ratio of the (meth)acrylate containing an alicyclic hydrocarbon group / C 1-20 alkyl ester of (meth)acrylic acid can be, for example, 10 / 90 or more, 20 / 80 or more, or 30 / 70 or more, and can also be 90 / 10 or less, 80 / 20 or less, or 70 / 30 or less.

[0092] As the constituent monomer components of the acrylic oligomer, in addition to the above (meth)acrylate monomers, functional group-containing monomers can be used as necessary. Examples of the functional group-containing monomers include monomers having a nitrogen atom-containing heterocyclic ring such as N-vinyl-2-pyrrolidone and N-acryloylmorpholine; amino group-containing monomers such as N,N-dimethylaminoethyl (meth)acrylate; amide group-containing monomers such as N,N-diethyl (meth)acrylamide; carboxy group-containing monomers such as acrylic acid (AA) and methacrylic acid (MAA); hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate. These functional group-containing monomers can be used alone or in combination of two or more. When using a functional group-containing monomer, the proportion of the functional group-containing monomer in all the monomer components constituting the acrylic oligomer can be, for example, 1% by weight or more, 2% by weight or more, or 3% by weight or more, and can also be, for example, 15% by weight or less, 10% by weight or less, or 7% by weight or less. The acrylic oligomer may not contain a functional group-containing monomer.

[0093] 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), 1-adamantyl acrylate (ADA), and copolymers of DCPMA and MMA, copolymers of DCPMA and IBXMA, copolymers of ADA and methyl methacrylate (MMA), 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 CHMA and AA, etc.

[0094] The acrylic oligomer can be formed by polymerizing its constituent monomer components. The polymerization method and mode are not particularly limited, and various conventionally known polymerization methods (for example, solution polymerization, emulsion polymerization, bulk polymerization, photopolymerization, radiation polymerization, etc.) can be adopted in an appropriate manner. The types of polymerization initiators (for example, azo-based polymerization initiators) that can be used as necessary are generally as exemplified for the synthesis of the acrylic polymer (A). The amount of the polymerization initiator and the amount of the chain transfer agent (for example, mercaptans) optionally used are appropriately set based on common general technical knowledge so as to obtain a desired molecular weight, and thus detailed description is omitted.

[0095] When the adhesive layer or the adhesive composition contains an acrylic oligomer, its content can be, for example, 0.01 part by weight or more, based on 100 parts by weight of the polymer (A). From the viewpoint of obtaining a higher effect, it may be 0.05 part by weight or more, 0.1 part by weight or more, or 0.2 part by weight or more. Also, from the viewpoint of compatibility with the polymer (A) and the like, the content of the acrylic oligomer based on 100 parts by weight of the polymer (A) is usually appropriately less than 50 parts by weight, preferably less than 30 parts by weight, more preferably 25 parts by weight or less, and may be, for example, 10 parts by weight or less, 5 parts by weight or less, or 1 part by weight or less. An adhesive layer or an adhesive composition that does not contain an acrylic oligomer may also be used.

[0096] The adhesive layer or the adhesive composition of the adhesive sheet disclosed herein may contain, as other optional components, various common additives in the field of adhesives, such as tackifier resins (for example, rosin-based, petroleum-based, terpene-based, phenolic-based, ketone-based tackifier resins), viscosity modifiers (for example, thickeners), leveling agents, plasticizers, fillers, colorants such as pigments and dyes, stabilizers, preservatives, antioxidants, etc. For such various additives, those conventionally known can be used by conventional methods and are not particularly characteristic of the present invention, so detailed description is omitted. Note that the technology disclosed herein can exhibit good adhesive strength without using the above-mentioned tackifier resin. Therefore, in some embodiments, the content of the tackifier resin in the adhesive layer or the adhesive composition can be, for example, less than 10 parts by weight, and further less than 5 parts by weight, based on 100 parts by weight of the polymer (A). The content of the tackifier resin may be less than 1 part by weight (for example, less than 0.5 part by weight), or may be less than 0.1 part by weight (0 part by weight or more and less than 0.1 part by weight). The adhesive layer or the adhesive composition may not contain a tackifier resin.

[0097] When the pressure-sensitive adhesive sheet disclosed herein is used for optical applications, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet may have predetermined optical properties (for example, transparency). From the perspective of such optical properties, it is preferable that the amount of components other than the polymer (A) and, if necessary, the photoreactive monomer (B) used in the formation of the pressure-sensitive adhesive layer (and thus the pressure-sensitive adhesive composition) is limited. In the technology disclosed herein, the amount of components other than the polymer (A) and the photoreactive monomer (B) in the pressure-sensitive adhesive layer is usually approximately 30% by weight or less, and it is appropriate that it is approximately 15% by weight or less, and preferably approximately 12% by weight or less (for example, approximately 10% by weight or less). In the pressure-sensitive adhesive sheet according to one embodiment, the amount of components other than the polymer (A) and the photoreactive monomer (B) in the pressure-sensitive adhesive layer may be approximately 5% by weight or less, may be approximately 3% by weight or less, or may be approximately 1.5% by weight or less (for example, approximately 1% by weight or less).

[0098] (Crosslinking agent) A crosslinking agent may be used in the pressure-sensitive adhesive layer as necessary. In the pressure-sensitive adhesive sheet disclosed herein, the crosslinking agent is typically contained in the pressure-sensitive adhesive layer in the form after the crosslinking reaction. By using the crosslinking agent, the cohesive force of the pressure-sensitive adhesive layer and the like can be appropriately adjusted. Further, in a pressure-sensitive adhesive sheet containing the photoreactive monomer (B) in the pressure-sensitive adhesive layer, by using the crosslinking agent and the photoreactive monomer (B) in combination, it is possible to preferably achieve both the flexibility of the pressure-sensitive adhesive layer before photocuring of the photoreactive monomer and the deformation resistance of the pressure-sensitive adhesive layer after photocuring.

[0099] The type of the crosslinking agent is not particularly limited, and it can be selected from conventionally known crosslinking agents so that the crosslinking agent exhibits an appropriate crosslinking function in the adhesive layer, for example, according to the composition of the adhesive composition. Examples of the crosslinking agent that can be used include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, carbodiimide-based crosslinking agents, melamine-based crosslinking agents, urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, hydrazine-based crosslinking agents, amine-based crosslinking agents, and the like. These can be used alone or in combination of two or more.

[0100] As the isocyanate-based crosslinking agent, a polyfunctional isocyanate compound having two or more functional groups can be used. For example, aromatic isocyanates such as tolylene diisocyanate, xylene diisocyanate, polymethylene polyphenyl diisocyanate, tris(p-isocyanatophenyl) thiophosphate, diphenylmethane diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; aliphatic isocyanates such as hexamethylene diisocyanate; and the like. Examples of commercially available products include isocyanate adducts such as trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, trade name "Coronate L"), trimethylolpropane / hexamethylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, trade name "Coronate HL"), isocyanurate form of hexamethylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate HX"), trimethylolpropane / xylylene diisocyanate adduct (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D-110N").

[0101] As the epoxy crosslinking agent, those having two or more epoxy groups in one molecule can be used without particular limitation. An epoxy crosslinking agent having 3 to 5 epoxy groups in one molecule is preferred. Specific examples of the epoxy crosslinking agent include N,N,N’,N’-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, polyglycerol polyglycidyl ether, and the like. Commercially available products of the epoxy crosslinking agent include "TETRAD-X", "TETRAD-C" manufactured by Mitsubishi Gas Chemical Company, "Epiclon CR-5L" manufactured by DIC Corporation, "Denacol EX-512" manufactured by Nagase ChemteX Corporation, "TEPIC-G" manufactured by Nissan Chemical Industries, Ltd., and the like.

[0102] As the oxazoline crosslinking agent, those having one or more oxazoline groups in one molecule can be used without particular limitation. Examples of the aziridine crosslinking agent include trimethylolpropane tris[3-(1-aziridinyl)propionate], trimethylolpropane tris[3-(1-(2-methyl)aziridinylpropionate)], and the like. As the carbodiimide crosslinking agent, a low molecular weight compound or a high molecular weight compound having two or more carbodiimide groups can be used.

[0103] In some embodiments, a peroxide may be used as the crosslinking agent. Examples of the peroxide include di(2-ethylhexyl) peroxydicarbonate, di(4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butyl peroxydicarbonate, t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutyl peroxyisobutyrate, dibenzoyl peroxide, and the like. Among these, particularly excellent peroxides in terms of crosslinking reaction efficiency include di(4-t-butylcyclohexyl) peroxydicarbonate, dilauroyl peroxide, dibenzoyl peroxide, and the like. When a peroxide is used as the polymerization initiator, it is also possible to use the peroxide remaining without being used in the polymerization reaction for the crosslinking reaction. In that case, the remaining amount of the peroxide is quantified, and if the ratio of the peroxide is less than the predetermined amount, the peroxide may be added as necessary to reach the predetermined amount. The quantification of the peroxide can be performed by the method described in Japanese Patent No. 4971517.

[0104] When using a crosslinking agent, the amount used (when using two or more crosslinking agents, the total amount thereof) is not particularly limited. From the perspective of realizing an adhesive that exhibits balanced adhesive properties such as adhesive strength and cohesive strength, the amount of the crosslinking agent used is usually suitably about 5 parts by weight or less, may be 3 parts by weight or less, may be 2 parts by weight or less, may be 1 part by weight or less, and may be less than 1 part by weight, based on 100 parts by weight of the polymer (A). In an embodiment where the crosslinking agent and the photoreactive monomer (B) are used in combination, from the perspective of preferably facilitating the exhibition of the effects of such combined use, the amount of the crosslinking agent used based on 100 parts by weight of the polymer (A) may be, for example, 0.80 parts by weight or less, may be 0.60 parts by weight or less, may be 0.30 parts by weight or less, and may be 0.10 parts by weight or less. The lower limit of the amount of the crosslinking agent used is not particularly limited, and it can be used in an amount more than 0 parts by weight based on 100 parts by weight of the polymer (A). In some embodiments, the amount of the crosslinking agent used can be, for example, 0.001 parts by weight or more, may be 0.01 parts by weight or more, and may be 0.03 parts by weight or more, based on 100 parts by weight of the polymer (A).

[0105] The technology disclosed herein can be preferably implemented in an embodiment using at least an isocyanate-based crosslinking agent as the crosslinking agent. The isocyanate-based crosslinking agent may be used in combination with other crosslinking agents. In an embodiment using the isocyanate-based crosslinking agent, the amount of the isocyanate-based crosslinking agent used based on 100 parts by weight of the polymer (A) may be, for example, 0.005 parts by weight or more, may be 0.01 parts by weight or more, and may be 0.03 parts by weight or more. Also, the amount of the isocyanate-based crosslinking agent used based on 100 parts by weight of the polymer (A) may be, for example, 10 parts by weight or less, may be 5 parts by weight or less, may be 3 parts by weight or less, may be less than 2 parts by weight, may be less than 1 part by weight, may be less than 0.80 parts by weight, may be less than 0.60 parts by weight, may be less than 0.30 parts by weight, may be less than 0.10 parts by weight, and may be less than 0.08 parts by weight.

[0106] In order to make the crosslinking reaction proceed more effectively, a crosslinking catalyst may be used. Examples of the crosslinking catalyst include metal-based crosslinking catalysts such as tetra-n-butyl titanate, tetra-isopropyl titanate, ferric naphthenate, butyltin oxide, dioctyltin dilaurate, etc. Among them, tin-based crosslinking catalysts such as dioctyltin dilaurate are preferred. The amount of the crosslinking catalyst used is not particularly limited. The amount of the crosslinking catalyst used can be, for example, approximately 0.0001 parts by weight or more, approximately 0.001 parts by weight or more, approximately 0.005 parts by weight or more, etc. with respect to 100 parts by weight of the polymer (A), and can also be approximately 1 part by weight or less, approximately 0.1 part by weight or less, approximately 0.05 part by weight or less, etc.

[0107] If desired, the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer may contain, as a crosslinking retarder, a compound that causes keto-enol tautomerism. For example, in a pressure-sensitive adhesive composition containing an isocyanate-based crosslinking agent or a pressure-sensitive adhesive composition that can be used by blending an isocyanate-based crosslinking agent, a compound that causes keto-enol tautomerism can be preferably used. Thereby, the effect of extending the pot life of the pressure-sensitive adhesive composition can be exhibited. As the compound that causes keto-enol tautomerism, various β-dicarbonyl compounds can be used. Specific examples include β-diketones such as acetylacetone and 2,4-hexanedione; acetoacetic acid esters such as methyl acetoacetate and ethyl acetoacetate; propionylacetic acid esters such as ethyl propionylacetate; isobutyrylacetic acid esters such as ethyl isobutyrylacetate; malonic acid esters such as methyl malonate and ethyl malonate; etc. Among them, preferred compounds include acetylacetone and acetoacetic acid esters. The compound that causes keto-enol tautomerism can be used alone or in combination of two or more. The amount of the compound that causes keto-enol tautomerism used can be, for example, 0.1 part by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the polymer (A), and usually it is appropriate to be 0.5 part by weight or more and 15 parts by weight or less, and can be, for example, 1 part by weight or more and 10 parts by weight or less, or 1 part by weight or more and 5 parts by weight or less.

[0108] (Silane coupling agent) In the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet disclosed herein, a silane coupling agent can be contained, if desired. By using the silane coupling agent, the peel strength from an adherend (e.g., a glass plate) of the pressure-sensitive adhesive sheet can be improved. The pressure-sensitive adhesive layer containing the silane coupling agent can be preferably formed using a pressure-sensitive adhesive composition containing the silane coupling agent. In such a pressure-sensitive adhesive composition, the silane coupling agent is preferably contained in the pressure-sensitive adhesive composition in a free form from the viewpoint of suppressing gelation and the like. Further, in some embodiments, the silane coupling agent is preferably contained in a free form in the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet disclosed herein. The silane coupling agent contained in the pressure-sensitive adhesive layer in such a form can effectively contribute to the improvement of the peel force. Here, the "free form" means that the silane coupling agent is not chemically bonded to other components contained in the pressure-sensitive adhesive composition or the pressure-sensitive adhesive layer.

[0109] Examples of the silane coupling agent include silicon compounds having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino group-containing silicon compounds such as 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane; 3-chloropropyltrimethoxysilane; trimethoxysilane containing an acetoacetyl group; (meth)acrylic group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; isocyanate group-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane; and the like. In some embodiments, by employing a silane coupling agent having a trialkoxysilyl group, the above-described effects can be more preferably exhibited. Among them, preferred silane coupling agents include 3-glycidoxypropyltrimethoxysilane and trimethoxysilane containing an acetoacetyl group.

[0110] When using the silane coupling agent, the amount used can be set so as to obtain a desired use effect and is not particularly limited. In some embodiments, the amount of the silane coupling agent used may be, for example, 0.001 parts by weight or more, more preferably 0.01 parts by weight or more, 0.05 parts by weight or more, or 0.1 parts by weight or more, based on 100 parts by weight of the polymer (A). From the perspective of suppressing gelation of the adhesive composition, etc., the amount of the silane coupling agent used based on 100 parts by weight of the polymer (A) is usually suitably 3 parts by weight or less, more preferably 1 part by weight or less, or 0.5 parts by weight or less.

[0111] (Photoinitiator) In the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet disclosed herein, a photoinitiator can be contained as needed for the purpose of improving or imparting photocurability. Examples of the photoinitiator include ketal-based photoinitiators, acetophenone-based photoinitiators, benzoin ether-based photoinitiators, acylphosphine oxide-based photoinitiators, α-ketol-based photoinitiators, aromatic sulfonyl chloride-based photoinitiators, photoactive oxime-based photoinitiators, benzoin-based photoinitiators, benzyl-based photoinitiators, benzophenone-based photoinitiators, thioxanthone-based photoinitiators, etc., which are the same as the photoinitiators exemplified as those that can be used in the synthesis of polymer (A). The photoinitiator can be used alone or in an appropriate combination of two or more kinds.

[0112] Specific examples of the ketal-based photoinitiator include 2,2-dimethoxy-1,2-diphenylethane-1-one and the like. Specific examples of the acetophenone-based photoinitiator include 1-hydroxycyclohexyl-phenyl-ketone, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, methoxyacetophenone and the like. Specific examples of the benzoin ether-based photoinitiator include benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and substituted benzoin ethers such as anisole methyl ether. Specific examples of the acylphosphine oxide-based photoinitiator include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide and the like. Specific examples of α-ketol-based photoinitiators include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one, etc. Specific examples of aromatic sulfonyl chloride-based photoinitiators include 2-naphthalenesulfonyl chloride, etc. Specific examples of photoactive oxime-based photoinitiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime, etc. Specific examples of benzoin-based photoinitiators include benzoin, etc. Specific examples of benzyl-based photoinitiators include benzyl, etc. Specific examples of benzophenone-based photoinitiators include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexyl phenyl ketone, etc. Specific examples of thioxanthone-based photoinitiators include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, etc.

[0113] The content of the photoinitiator in the pressure-sensitive adhesive layer is not particularly limited and can be set so that the desired effect is appropriately exerted. In some embodiments, the content of the photoinitiator can be, for example, at least about 0.005 parts by weight based on 100 parts by weight of the polymer (A) contained in the pressure-sensitive adhesive layer, usually preferably at least 0.01 parts by weight, preferably at least 0.05 parts by weight, may be at least 0.10 parts by weight, may be at least 0.15 parts by weight, and may be at least 0.20 parts by weight. With an increase in the content of the photoinitiator, the photocurability of the pressure-sensitive adhesive layer tends to improve. Also, the content of the photoinitiator based on 100 parts by weight of the polymer (A) is usually preferably 10 parts by weight or less, preferably 7 parts by weight or less, may be 5 parts by weight or less, may be 3 parts by weight or less, may be 2 parts by weight or less, and may be 1 part by weight or less. The fact that the content of the photoinitiator is not too much can be advantageous from the viewpoint of improving the storage stability of the pressure-sensitive adhesive sheet (for example, stability against photo-degradation).

[0114] The pressure-sensitive adhesive layer containing a photoinitiator can typically be formed using a pressure-sensitive adhesive composition containing the photoinitiator (for example, a solvent-based pressure-sensitive adhesive composition). The pressure-sensitive adhesive composition containing a photoinitiator can be prepared, for example, by mixing the photoinitiator with other components used in the composition. Also, when preparing a pressure-sensitive adhesive composition using a polymer (A) (for example, an acrylic polymer (A)) synthesized (photopolymerized) in the presence of a photoinitiator, the residue (unreacted product) of the photoinitiator used when synthesizing the polymer (A) may be used as part or all of the photoinitiator contained in the pressure-sensitive adhesive layer. The same applies when using an acrylic oligomer synthesized in the presence of a photoinitiator as the acrylic oligomer used as needed. From the viewpoint of ease of production management, the pressure-sensitive adhesive layer disclosed herein can preferably be formed using a pressure-sensitive adhesive composition prepared by newly adding the photoinitiator in the above-described amount to other constituent components.

[0115] In addition, the pressure-sensitive adhesive layer in the technology disclosed herein may optionally contain known additives that can be used in pressure-sensitive adhesives, such as leveling agents, plasticizers, softening agents, colorants (dyes, pigments, etc.), fillers, antistatic agents, antioxidants, ultraviolet absorbers, antioxidants, light stabilizers, preservatives, etc., as long as the effects of the present invention are not significantly hindered. Note that for pressure-sensitive adhesive sheets intended for applications where the inclusion of siloxane is undesirable (e.g., in the manufacture of electronic devices), it is desirable to avoid using silicone-based additives (e.g., silicone-based leveling agents and defoaming agents).

[0116] <Formation of the pressure-sensitive adhesive layer> The pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet disclosed herein can be a cured layer of a pressure-sensitive adhesive composition containing corresponding components. That is, the above pressure-sensitive adhesive layer can be formed by appropriately applying (e.g., coating) the above pressure-sensitive adhesive composition onto a suitable surface and then appropriately performing curing treatments such as drying (e.g., heat drying), crosslinking (e.g., crosslinking by the reaction of the above-described crosslinking agent), and cooling. When performing two or more curing treatments, these can be performed simultaneously or stepwise.

[0117] In some embodiments, the above pressure-sensitive adhesive composition contains at least any one of the above-described polymers (A). A pressure-sensitive adhesive composition according to a preferred embodiment contains an acrylic polymer (A) as the above polymer (A). The above pressure-sensitive adhesive composition may contain the above polymer (A) in the form of its precursor. The above pressure-sensitive adhesive composition preferably contains any one of the above-described polymers (A) and any one of the above-described photoreactive monomers (B). The above photoreactive monomer (B) preferably contains a compound B1 having a ring structure and two or more ethylenically unsaturated groups in the molecule. The above compound B1 preferably has a molecular weight of 100 g / mol or more per ethylenically unsaturated group.

[0118] The form of the above-mentioned adhesive composition is not particularly limited. For example, it can be various conventionally known forms such as an aqueous dispersion-type adhesive composition in which an adhesive (adhesive component) is dispersed in water, a solvent-type adhesive composition in which an adhesive is contained in an organic solvent, a hot-melt type adhesive composition that is applied in a heat-melted state and forms an adhesive when cooled to near room temperature, etc. From the viewpoints of ease of preparation of the adhesive composition and ease of formation of the adhesive layer, in some aspects, a solvent-type adhesive composition can be preferably adopted. The solvent-type adhesive composition can be preferably prepared using a polymer (A) that is a polymer obtained by solution polymerization of a monomer component.

[0119] The application of the adhesive composition can be carried out using conventional coaters such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, etc. In the case of an adhesive sheet having a support, as a method of providing an adhesive layer on the support, a direct method of directly applying the adhesive composition to the support to form the adhesive layer may be used, or a transfer method of transferring the adhesive layer formed on the release surface to the support may also be used.

[0120] The thickness of the adhesive layer is not particularly limited and can be, for example, about 3 μm to 500 μm. From the viewpoint of impact resistance, in some aspects, the thickness of the adhesive layer is suitably 5 μm or more, preferably 10 μm or more, and more preferably 15 μm or more. Also, in some aspects, the thickness of the adhesive layer can be, for example, 200 μm or less, preferably 120 μm or less from the viewpoint of suppressing deformation of the adhesive layer, and may be 100 μm or less, 70 μm or less, 50 μm or less, or 35 μm or less. According to the adhesive sheet disclosed herein, in an aspect having an adhesive layer with a thickness of, for example, 70 μm or less, a joint with high deformation resistance and high impact resistance can be formed.

[0121] <Support> The pressure-sensitive adhesive sheet according to some aspects can be in the form of a pressure-sensitive adhesive sheet with a support body, which includes a support body joined to a pressure-sensitive adhesive layer. The material of the support body is not particularly limited and can be appropriately selected according to the purpose of use and the usage mode of the pressure-sensitive adhesive sheet, etc. Non-limiting examples of the support body that can be used include polyolefin films mainly composed of polyolefins such as polypropylene and ethylene-propylene copolymers, polyester films mainly composed of polyesters such as polyethylene terephthalate and polybutylene terephthalate, resin films such as polyvinyl chloride films mainly composed of polyvinyl chloride; foam sheets made of foams such as polyurethane foam, polyethylene foam, and polychloroprene foam; various fibrous substances (which can be natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, semi-synthetic fibers such as acetate, etc.).) Woven fabrics and non-woven fabrics by single or blended spinning, etc.; papers such as Japanese paper, fine paper, kraft paper, crepe paper, etc.; metal foils such as aluminum foil and copper foil; etc. A support body having a composite structure of these may also be used. Examples of such a support body with a composite structure include, for example, a support body having a structure in which a metal layer (for example, a metal foil, or a continuous or discontinuous metal sputter layer, metal vapor deposition layer, metal plating layer, etc.) or a metal oxide layer and the above resin film are laminated, a resin sheet reinforced with inorganic fibers such as glass cloth, etc. The above support body may correspond to an optical member (for example, an optical film) described later, or may be a transparent member formed of a transparent material (for example, a resin material having transparency or glass, etc.).

[0122] As the support for the pressure-sensitive adhesive sheet disclosed herein, various films (hereinafter also referred to as support films) can be preferably used. The support film may be a porous film such as a foam film or a non-woven fabric sheet, a non-porous film, or a film having a structure in which a porous layer and a non-porous layer are laminated. In some embodiments, as the support film, those containing a resin film that can maintain its shape independently (self-supporting or non-dependent) as a base film can be preferably used. Here, the "resin film" means a resin film having a non-porous structure and typically substantially containing no air bubbles (voidless). Therefore, the resin film is a concept distinct from a foam film or a non-woven fabric. The resin film may have a single-layer structure or a multi-layer structure of two or more layers (for example, a three-layer structure).

[0123] As the resin material constituting the resin film, for example, polyester, polyolefin, polycycloolefin derived from monomers having an aliphatic cyclic structure such as a norbornene structure, polyamide (PA) such as nylon 6, nylon 66, and partially aromatic polyamide, polyimide (PI), polyamideimide (PAI), polyetheretherketone (PEEK), polyethersulfone (PES), polyphenylene sulfide (PPS), polycarbonate (PC), polyurethane (PU), ethylene-vinyl acetate copolymer (EVA), polystyrene, polyvinyl chloride, polyvinylidene chloride, fluororesin such as polytetrafluoroethylene (PTFE), acrylic resin such as polymethyl methacrylate, cellulose-based polymers such as diacetyl cellulose and triacetyl cellulose, vinyl butyral-based polymers, allylate-based polymers, polyoxymethylene-based polymers, epoxy-based polymers and other resins can be used. The resin film may be formed using a resin material containing one of such resins alone, or may be formed using a resin material in which two or more are blended. The resin film may be unstretched or stretched (for example, uniaxially stretched or biaxially stretched).

[0124] Preferable examples of the resin material constituting the resin film include polyester resins, PPS resins, and polyolefin resins. Here, the polyester resin refers to a resin containing polyester at a ratio exceeding 50% by weight. Similarly, the PPS resin refers to a resin containing PPS at a ratio exceeding 50% by weight, and the polyolefin resin refers to a resin containing polyolefin at a ratio exceeding 50% by weight.

[0125] As the polyester resin, typically, a polyester resin mainly containing a polyester obtained by polycondensing a dicarboxylic acid and a diol is used. Specific examples of the polyester resin include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate, and the like.

[0126] As the polyolefin resin, one type of polyolefin can be used alone, or two or more types of polyolefins can be combined and used. The polyolefin can be, for example, a homopolymer of α-olefin, a copolymer of two or more types of α-olefins, a copolymer of one or two or more types of α-olefins and other vinyl monomers, etc. Specific examples include polyethylene (PE), polypropylene (PP), poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymers such as ethylene-propylene rubber (EPR), ethylene-propylene-butene copolymers, ethylene-butene copolymers, ethylene-vinyl alcohol copolymers, ethylene-ethyl acrylate copolymers, etc. Both low-density (LD) polyolefins and high-density (HD) polyolefins can be used. Examples of polyolefin resin films include unstretched polypropylene (CPP) films, biaxially stretched polypropylene (OPP) films, low-density polyethylene (LDPE) films, linear low-density polyethylene (LLDPE) films, medium-density polyethylene (MDPE) films, high-density polyethylene (HDPE) films, polyethylene (PE) films blended with two or more types of polyethylene (PE), PP / PE blend films blended with polypropylene (PP) and polyethylene (PE), etc.

[0127] Specific examples of resin films that can be preferably used as the support include PET films, PEN films, PPS films, PEEK films, CPP films, and OPP films. Preferred examples from the viewpoint of strength include PET films, PEN films, PPS films, and PEEK films. A preferred example from the viewpoints of easy availability, dimensional stability, optical properties, etc. is the PET film.

[0128] Known additives such as light stabilizers, antioxidants, antistatic agents, colorants (dyes, pigments, etc.), fillers, slip agents, antiblocking agents, etc. can be blended into the resin film as necessary. The blending amount of the additive is not particularly limited and can be appropriately set according to the use of the adhesive sheet, etc.

[0129] The method for manufacturing the resin film is not particularly limited. For example, conventionally known general resin film forming methods such as extrusion molding, inflation molding, T-die casting molding, calender roll molding, etc. can be appropriately employed.

[0130] The above-mentioned support may be a support film substantially composed of such a resin film. Further, the above-mentioned support may be a support film including an auxiliary layer in addition to the above-mentioned resin film. The above-mentioned auxiliary layer may be disposed on the adhesive layer side of the resin film, may be disposed on the side opposite to the adhesive layer, or may be disposed on both sides of the resin film. Examples of the above-mentioned auxiliary layer include an optical property adjustment layer (e.g., a coloring layer, an antireflection layer), a decorative layer (e.g., a printing layer, a laminate layer, a continuous or discontinuous metal layer, a continuous or discontinuous metal oxide layer, etc.) that imparts a desired appearance to the support or the adhesive sheet, a conductive layer, an antistatic layer, an undercoat layer, a release layer, etc.

[0131] The thickness of the support is not particularly limited and can be selected according to the purpose of use and the usage mode of the adhesive sheet, etc. The thickness of the support may be, for example, 1000 μm or less, may be 500 μm or less, may be 100 μm or less, may be 70 μm or less, may be 50 μm or less, may be 25 μm or less, may be 10 μm or less, or may be 5 μm or less. When the thickness of the support decreases, the flexibility of the adhesive sheet and the followability to the surface shape of the adherend tend to improve. Also, from the viewpoints of handleability and processability, etc., the thickness of the support may be, for example, 2 μm or more, may be more than 5 μm or more than 10 μm. In some embodiments, the thickness of the support may be, for example, 20 μm or more, may be 35 μm or more, or may be 55 μm or more.

[0132] On the surface of the support on the side joined to the adhesive layer, if necessary, conventionally known surface treatments such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, application of a primer, antistatic treatment, etc. may be performed. Such surface treatment can be a treatment for improving the adhesion between the support and the adhesive layer, in other words, the anchoring property of the adhesive layer to the support. The composition of the primer is not particularly limited and can be appropriately selected from known ones. The thickness of the primer layer is not particularly limited, but usually about 0.01 μm to 1 μm is appropriate, and about 0.1 μm to 1 μm is preferable.

[0133] In the single-sided adhesive sheet with a support, on the surface of the support on the side opposite to the side joined to the adhesive layer (hereinafter also referred to as the back surface), if necessary, conventionally known surface treatments such as release treatment, adhesion or adhesiveness improvement treatment, antistatic treatment, etc. may be performed. For example, by surface-treating the back surface of the support with a release treatment agent, the rewinding force of the adhesive sheet in the form of being wound into a roll can be reduced. As the release treatment agent, silicone-based release treatment agents, long-chain alkyl-based release treatment agents, olefin-based release treatment agents, fluorine-based release treatment agents, fatty acid amide-based release treatment agents, molybdenum sulfide, silica powder, etc. can be used.

[0134] <Method for manufacturing a laminate> The adhesive sheet disclosed herein can preferably be used in a mode of attaching to the adherend by a method including photocuring the adhesive layer after laminating the adhesive sheet to the adherend. By laminating the adhesive sheet to the adherend, an adherend with the adhesive sheet laminated thereon is formed. By photocuring the adhesive layer of this adhesive sheet, a laminate including the adherend with the cured adhesive layer and the above adherend is obtained. Therefore, according to this specification, a method for manufacturing a laminate is provided, which includes laminating any of the adhesive sheets disclosed herein to an adherend and irradiating the adhesive sheet with ultraviolet rays to photocure the adhesive layer in this order.

[0135] <Use> The pressure-sensitive adhesive sheet disclosed herein can be used for applications such as fixing, joining, forming, decorating, protecting, and supporting members that make up various products. The material constituting at least the surface of the above-mentioned members can be, for example, glass such as alkali glass or non-alkali glass; metal materials such as stainless steel (SUS), aluminum, etc.; resin materials such as acrylic resin, ABS resin, polycarbonate resin, polystyrene resin, etc.; and the like. The above-mentioned members can be, for example, members that make up various portable devices, automobiles, household appliances, etc. Further, the surface of the above-mentioned members to which the pressure-sensitive adhesive sheet is attached may be a painted surface with a paint such as an acrylic-based, polyester-based, alkyd-based, melamine-based, urethane-based, acid epoxy cross-linked-based, or a composite system thereof (for example, acrylic melamine-based, alkyd melamine-based), or a plated surface such as a zinc-plated steel sheet. Further, the above-mentioned members may be any of the support films exemplified as materials that can be used for the support, for example, a resin film or a support film having a continuous or discontinuous inorganic layer (which can be a metal layer, a metal oxide layer, etc.) on the resin film. The pressure-sensitive adhesive sheet disclosed herein can be, for example, a component of a member with a pressure-sensitive adhesive sheet in which the above-mentioned member is joined to at least one surface of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive layer.

[0136] As an example of a preferred application, optical applications can be mentioned. More specifically, for example, as an optical pressure-sensitive adhesive sheet used for applications such as bonding optical members (for bonding optical members) or manufacturing applications of products (optical products) using the above-mentioned optical members, the pressure-sensitive adhesive sheet disclosed herein can be preferably used.

[0137] The above-mentioned optical member refers to a member having optical properties (e.g., polarization, photo-refractivity, light scattering, light reflection, light transmittance, light absorption, light diffraction, optical rotation, visibility, etc.). The above-mentioned optical member is not particularly limited as long as it is a member having optical properties. For example, it includes members constituting devices (optical devices) such as display devices (image display devices) and input devices, or members used in these devices. Examples include polarizing plates, wave plates, retardation plates, optical compensation films, brightness enhancement films, light guide plates, reflection films, anti-reflection films, hard coat (HC) films, impact absorption films, antifouling films, photochromic films, dimming films, transparent conductive films (ITO films), design films, decorative films, surface protection plates, prisms, lenses, color filters, transparent substrates, and further members in which these are laminated (these may be collectively referred to as "functional films"). Note that the above-mentioned "plates" and "films" include forms such as plate-like, film-like, and sheet-like. For example, "polarizing film" includes "polarizing plate", "polarizing sheet", etc.

[0138] Examples of the above-mentioned display device include liquid crystal display devices, organic EL (electroluminescence) display devices, PDP (plasma display panels), electronic paper, etc. Examples of the above-mentioned input device include touch panels, etc.

[0139] The above-mentioned optical member is not particularly limited. For example, it includes members made of glass, acrylic resin, polycarbonate, polyethylene terephthalate, metal thin films, etc. (e.g., sheet-like, film-like, or plate-like members). Note that the "optical member" in this specification also includes members that play a role in decoration and protection while maintaining the visibility of display devices and input devices (such as design films, decorative films, and surface protection films).

[0140] The mode of bonding optical members using the pressure-sensitive adhesive sheet disclosed herein is not particularly limited. For example, (1) a mode of bonding optical members to each other via the pressure-sensitive adhesive sheet disclosed herein, (2) a mode of bonding an optical member to a member other than an optical member via the pressure-sensitive adhesive sheet disclosed herein, or (3) a mode in which the pressure-sensitive adhesive sheet disclosed herein includes an optical member and the pressure-sensitive adhesive sheet is bonded to an optical member or a member other than an optical member may be used. In the mode (3) above, the pressure-sensitive adhesive sheet in a form including an optical member may be, for example, a pressure-sensitive adhesive sheet in which the support is an optical member (e.g., an optical film). The pressure-sensitive adhesive sheet in a form including an optical member as the support can also be regarded as a pressure-sensitive adhesive optical member (e.g., a pressure-sensitive adhesive optical film). Further, when the pressure-sensitive adhesive sheet disclosed herein is a type of pressure-sensitive adhesive sheet having a support and the functional film is used as the support, the pressure-sensitive adhesive sheet disclosed herein can also be regarded as a "pressure-sensitive adhesive functional film" having the pressure-sensitive adhesive layer disclosed herein on at least one side of the functional film.

[0141] Note that the matters disclosed by this specification include the following. (1) A pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer contains a polymer (A) and a photoreactive monomer (B), the photoreactive monomer (B) includes a compound B1 having two or more ethylenically unsaturated groups, the compound B1 has a molecular weight (functional group equivalent weight) of 100 g / mol or more per ethylenically unsaturated group, and is a pressure-sensitive adhesive sheet. (2) The pressure-sensitive adhesive sheet according to (1) above, wherein the compound B1 contains a ring structure in the molecule. (3) The pressure-sensitive adhesive sheet according to (2) above, wherein the compound B1 contains at least one structure selected from the group consisting of a bisphenol A structure, a bisphenol F structure, and a bisphenol E structure in the molecule. (4) The pressure-sensitive adhesive sheet according to (2) or (3) above, wherein the compound B1 contains an aliphatic ring structure as the ring structure. (5) The pressure-sensitive adhesive sheet according to any one of (1) to (4) above, wherein the compound B1 contains at least one structure selected from the group consisting of a hydroxyl group and an amino group in the molecule. (6) The pressure-sensitive adhesive sheet according to any one of (1) to (5) above, wherein the content of the compound B1 in the pressure-sensitive adhesive layer is 0.5 parts by weight or more and 60 parts by weight or less with respect to 100 parts by weight of the polymer (A). (7) The pressure-sensitive adhesive sheet according to any one of (2) to (5) above, wherein the pressure-sensitive adhesive layer contains, as the photoreactive monomer (B), the compound B1 and a compound B2 having 2 or more functional groups and no ring structure in the molecule. (8) The pressure-sensitive adhesive sheet according to (7) above, wherein the functional group equivalent of the compound B2 is smaller than the functional group equivalent of the compound B1. (9) The pressure-sensitive adhesive sheet according to (7) or (8) above, wherein the functional group equivalent of the compound B2 is 400 g / mol or less. (10) The pressure-sensitive adhesive sheet according to any one of (7) to (9) above, wherein the content of the compound B2 in the pressure-sensitive adhesive layer is 25 parts by weight or less with respect to 100 parts by weight of the polymer (A). (11) The pressure-sensitive adhesive sheet according to any one of (1) to (10) above, wherein the content of the photoreactive monomer (B) in the pressure-sensitive adhesive layer is 1 part by weight or more and 80 parts by weight or less with respect to 100 parts by weight of the polymer (A). (12) The pressure-sensitive adhesive sheet according to any one of (1) to (11) above, wherein the polymer (A) is an acrylic polymer. (13) The pressure-sensitive adhesive sheet according to (12) above, wherein the monomer component constituting the acrylic polymer contains a monomer having a nitrogen atom-containing ring. (14) The pressure-sensitive adhesive sheet according to any one of (1) to (13) above, wherein the glass transition temperature of the polymer (A) is -45°C or higher and lower than 0°C. (15) The pressure-sensitive adhesive sheet according to any one of (1) to (14) above, wherein the pressure-sensitive adhesive layer is crosslinked with a crosslinking agent. (16) The pressure-sensitive adhesive sheet according to any one of (1) to (15) above, wherein the pressure-sensitive adhesive layer contains a photopolymerization initiator. (17) The pressure-sensitive adhesive sheet according to any one of (1) to (14) above, wherein the pressure-sensitive adhesive layer contains a silane coupling agent. (18) The pressure-sensitive adhesive sheet according to any one of (1) to (17) above, wherein the tensile elastic modulus measured by the above tensile test is 3.0 MPa or more. (19) The impact resistance measured by the above shear impact test is 2.0 J / (10 mm) 2 or more, and the pressure-sensitive adhesive sheet according to any one of (1) to (18) above. (20) The pressure-sensitive adhesive sheet according to any one of (1) to (19) above, wherein the peel strength measured by the above peel test is 1.0 N / 10 mm or more.

[0142] (21) Containing polymer (A) and photo-reactive monomer (B), wherein the photo-reactive monomer (B) contains a compound B1 having two or more ethylenically unsaturated groups, and the compound B1 has a molecular weight (functional group equivalent weight) of 100 g / mol or more per ethylenically unsaturated group, and is a pressure-sensitive adhesive composition. (22) The pressure-sensitive adhesive sheet according to (21) above, wherein the compound B1 contains a ring structure in the molecule. (23) The pressure-sensitive adhesive composition according to (22) above, wherein the compound B1 contains at least one structure selected from the group consisting of a bisphenol A structure, a bisphenol F structure, and a bisphenol E structure in the molecule. (24) The pressure-sensitive adhesive composition according to (2) or (23) above, wherein the compound B1 contains an aliphatic ring structure as the ring structure. (25) The pressure-sensitive adhesive composition according to any one of (21) to (24) above, wherein the compound B1 contains at least one structure selected from the group consisting of a hydroxyl group and an amino group in the molecule. (26) The pressure-sensitive adhesive composition according to any one of (21) to (25) above, wherein the content of the compound B1 in the pressure-sensitive adhesive layer is 0.5 parts by weight or more and 60 parts by weight or less with respect to 100 parts by weight of the polymer (A). (27) The pressure-sensitive adhesive layer is the pressure-sensitive adhesive composition according to any one of (22) to (25) above, which contains, as the above photoreactive monomer (B), the above compound B1 and a compound B2 having 2 or more functional groups and no ring structure in the molecule. (28) The pressure-sensitive adhesive composition according to (27) above, wherein the functional group equivalent of the above compound B2 is smaller than the functional group equivalent of the above compound B1. (29) The pressure-sensitive adhesive composition according to (27) or (28) above, wherein the functional group equivalent of the above compound B2 is 400 g / mol or less. (30) The pressure-sensitive adhesive composition according to any one of (27) to (29) above, wherein the content of the above compound B2 in the above pressure-sensitive adhesive layer is 25 parts by weight or less with respect to 100 parts by weight of the above polymer (A). (31) The pressure-sensitive adhesive composition according to any one of (21) to (30) above, wherein the content of the above photoreactive monomer (B) in the above pressure-sensitive adhesive layer is 1 part by weight or more and 80 parts by weight or less with respect to 100 parts by weight of the above polymer (A). (32) The pressure-sensitive adhesive composition according to any one of (21) to (31) above, wherein the above polymer (A) is an acrylic polymer. (33) The pressure-sensitive adhesive composition according to (32) above, wherein the monomer component constituting the above acrylic polymer contains a monomer having a nitrogen atom-containing ring. (34) The pressure-sensitive adhesive composition according to any one of (21) to (33) above, wherein the glass transition temperature of the above polymer (A) is -45°C or higher and lower than 0°C. (35) The pressure-sensitive adhesive composition according to any one of (21) to (34) above, wherein the above pressure-sensitive adhesive composition contains a crosslinking agent. (36) The pressure-sensitive adhesive composition according to any one of (21) to (35) above, wherein the above pressure-sensitive adhesive composition contains a photopolymerization initiator. (37) The pressure-sensitive adhesive composition according to any one of (21) to (36) above, wherein the above pressure-sensitive adhesive composition contains a silane coupling agent. (38) The pressure-sensitive adhesive composition according to any one of (21) to (37) above, which is used to form the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to any one of (1) to (20). An adhesive sheet comprising an adhesive layer composed of the adhesive composition according to any one of (21) to (37) above.

[0143] (40) An adhesive sheet containing an adhesive layer, wherein the tensile elastic modulus measured by the above tensile test is 3.0 MPa or more, and the impact resistance measured by the above shear impact test is 2.0 J / (10 mm) 2 or more. An adhesive sheet. (41) The adhesive sheet according to (40) above, wherein the peel strength measured by the above peel test is 1.0 N / 10 mm or more. (42) The adhesive sheet according to any one of (40) to (41) above, wherein the adhesive layer is the adhesive layer according to any one of (1) to (17) above. (43) The adhesive sheet according to any one of (40) to (42) above, wherein the adhesive layer is an adhesive layer formed from the adhesive composition according to any one of (21) to (37) above.

[0144] (44) The adhesive composition according to any one of (21) to (37) above, wherein the tensile elastic modulus measured by the above tensile test for an adhesive layer having a thickness selected from the range of 5 μm to 200 μm (preferably in the range of 15 μm to 25 μm) formed from the adhesive composition (for example, an adhesive layer having a thickness of 20 μm) is 3.0 MPa or more. (45) The adhesive composition according to (44) above, wherein the impact resistance measured by the above shear impact test for the adhesive layer having the above thickness formed from the adhesive composition is 2.0 J / (10 mm) 2 or more. The adhesive composition according to (44) above. (46) The adhesive composition according to (44) or (45) above, wherein the peel strength measured by the above peel test for the adhesive layer having the above thickness formed from the adhesive composition is 1.0 N / 10 mm or more. (47) An adhesive sheet - attached film member comprising the adhesive sheet according to any one of (1) to (20) and (40) to (43) above, and a film member joined to the adhesive layer. Bonding the pressure-sensitive adhesive sheet according to any one of (1) to (20) and (40) to (43) above to an adherend, irradiating the pressure-sensitive adhesive sheet with ultraviolet rays to photocure the pressure-sensitive adhesive layer, A method for manufacturing a laminate, which includes the above steps in this order.

[0145] Hereinafter, some examples of the present invention will be described, but the present invention is not intended to be limited to those shown in the examples. In the following description, "parts" and "%" are based on weight unless otherwise specified.

[0146] <Synthesis of Polymer (A)> (Polymer P1) Into a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer, and a stirring device, 60 parts of n-butyl acrylate (BA), 6 parts of cyclohexyl acrylate (CHA), 18 parts of N-vinyl-2-pyrrolidone (NVP), 1 part of isostearyl acrylate (iSTA), and 15 parts of 4-hydroxybutyl acrylate (4HBA) were charged as monomer components, 0.085 part of α-thioglycerol was charged as a chain transfer agent, 122 parts of ethyl acetate was charged as a polymerization solvent, and 0.2 part of 2,2'-azobisisobutyronitrile (AIBN) was charged as a thermal polymerization initiator. Solution polymerization was carried out under a nitrogen atmosphere to obtain a solution of Polymer P1. The weight average molecular weight (Mw) of Polymer P1 was 300,000. The Tg of Polymer P1 calculated from the composition of the above monomer components was -33°C.

[0147] (Polymer P2) Into a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer, and a stirring device, 64.5 parts of BA, 6 parts of CHA, 9.6 parts of NVP, 5 parts of iSTA, and 14.9 parts of 4HBA were charged as monomer components, 0.07 part of α-thioglycerol was charged as a chain transfer agent, 122 parts of ethyl acetate was charged as a polymerization solvent, and 0.2 part of AIBN was charged as a thermal polymerization initiator. Solution polymerization was carried out under a nitrogen atmosphere to obtain a solution of Polymer P2. The Mw of Polymer P2 was 600,000. The Tg of Polymer P2 calculated from the composition of the above monomer components was -39°C.

[0148] <Preparation of Adhesive Composition> (Example 1) To the solution of polymer P1 obtained above, per 100 parts of the monomer components used for preparing the solution, 0.05 part of isocyanate-based crosslinking agent X1 (trimethylolpropane / xylene diisocyanate adduct (manufactured by Mitsui Chemicals, Inc., trade name: Takenate D-110N, solid content concentration 75%)) based on solid content, 0.01 part of dioctyltin dilaurate (manufactured by Tokyo Fine Chemical Co., Ltd., trade name: Envirez OL-1) as a crosslinking accelerator, 4 parts of acetylacetone as a crosslinking retarder, 0.3 part of 3-glycidoxypropyltrimethoxysilane (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) as a silane coupling agent, 8 parts of dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "A-DPH") and 12 parts of tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "A-DCP") as photoreactive monomers, and 0.72 part of 1-hydroxycyclohexyl-phenyl-ketone (manufactured by IGM Regins, trade name: Omnirad 184) as a photopolymerization initiator were added and uniformly mixed to prepare a solvent-based adhesive composition according to Example 1.

[0149] (Examples 2 to 3, 5 to 12) Solvent-based adhesive compositions according to each example were prepared in the same manner as the preparation of the solvent-based adhesive composition according to Example 1, except that the type and amount of the photoreactive monomer, the amount of the crosslinking agent, and the amount of the photopolymerization initiator were as shown in Tables 1 and 2.

[0150] (Example 4) A solvent-based adhesive composition according to this example was prepared in the same manner as the preparation of the solvent-based adhesive composition according to Example 3, except that isocyanate-based crosslinking agent X2 (trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, trade name: Coronate L)) was used instead of isocyanate-based crosslinking agent X1.

[0151] (Example 13) A solvent-based pressure-sensitive adhesive composition according to this example was prepared in the same manner as in Example 10, except that a solution of polymer P2 was used instead of the solution of polymer P1.

[0152] <Production of Adhesive Sheet> On the release surface of a release film R1 (manufactured by Mitsubishi Rayon Co., Ltd., MRF#38) with a thickness of 38 μm, one side of which is the release surface of a polyester film, the solvent-based pressure-sensitive adhesive composition according to each of the above-prepared examples was applied and dried at 130 °C for 3 minutes to form a photocurable pressure-sensitive adhesive layer (a supportless double-sided adhesive sheet) with a thickness of 20 μm. On the surface of this pressure-sensitive adhesive layer, the release surface of a release film R2 (manufactured by Mitsubishi Rayon Co., Ltd., MRE#38) with a thickness of 38 μm, one side of which is the release surface of a polyester film, was laminated and protected. In this way, a laminated sheet having a structure in which the release film R1, the supportless double-sided adhesive sheet, and the release film R2 are laminated in this order was obtained.

[0153] <Measurement and Evaluation> The following measurements and evaluations were performed on the obtained adhesive sheet. (1) Measurement of Tensile Modulus On each laminated sheet according to the examples (a laminated sheet having a structure in which a supportless pressure-sensitive adhesive layer is sandwiched between two transparent release films), ultraviolet rays were irradiated using a high-pressure mercury lamp under the conditions of an illuminance of 300 mW / cm 2 and an integrated light quantity of 3000 mJ / cm 2 . After aging at 50 °C for 48 hours, the laminated sheet was cut into a size of 10 mm in width and 150 mm in length. In an environment of 23 °C and 50% RH, the release films R1 and R2 were peeled off to expose the pressure-sensitive adhesive layer, and a tensile test of the above test piece was performed using a tensile tester (manufactured by Minebea Co., Ltd., universal tensile compression tester, apparatus name "Tensile Compression Tester, TCM-1kNB") under the conditions of a chuck distance of 120 mm and a tensile speed of 50 mm / min to obtain an S-S curve, and the tensile modulus [MPa] was calculated from its initial slope (the elastic deformation region of the above S-S curve, specifically, the slope in the range where the displacement is less than approximately 5%). The measurement was performed 3 times (i.e., n = 3), and Tables 1 and 2 show the arithmetic mean values thereof.

[0154] (2) Measurement of impact resistance A pendulum-type adhesive shear impact tester based on JIS K6855 was used to conduct a shear impact test. As the measurement sample, the laminated sheet according to each example was cut into a 10 mm square, the release film R1 was peeled off to expose the first surface of the adhesive layer, and the first surface was bonded to the center of a chemically strengthened glass plate (manufactured by Corning Inc.) with a size of 25 mm square and a thickness of 1.7 mm. After that, the release film R2 was peeled off and the second surface of the adhesive layer was attached to the center of a 40 mm square stainless steel plate (SUS304BA plate), and pressure-bonded with a 5 N weight for 10 seconds. Then, autoclave treatment (50 °C, 0.5 MPa, 15 minutes) was performed, and from the glass plate side, using a high-pressure mercury lamp, the illuminance was 300 mW / cm 2 , and the cumulative light quantity was 3000 mJ / cm 2 . After irradiating with ultraviolet rays under the conditions of, aging was performed at 50 °C for 48 hours and the obtained samples were used. The above measurement sample was fixed so that the stainless steel plate was on the lower side, and in an environment of 23 °C and 50% RH, when a hammer was applied to the outer peripheral side surface of the glass plate under the conditions of a hammer energy of 2.75 J and a hammer speed (impact speed) of 3.5 m / s, the impact resistance [J / (10 mm) 2 was obtained. The measurement was performed 3 times, and Tables 1 and 2 show the arithmetic mean values thereof.

[0155] (3) Peel strength The laminated sheet according to each example was cut into a size of 10 mm in width and 150 mm in length to prepare a test piece. The first surface of the adhesive layer in the test piece was pressure-bonded to a glass plate (alkali glass plate manufactured by Matsunami Glass Industry Co., Ltd., produced by the float method, thickness 1.35 mm, blue plate edge polished product) by reciprocating a 2 kg rubber roller once, and after autoclave treatment (50 °C, 0.5 MPa, 15 minutes), from the glass plate side, using a high-pressure mercury lamp, the illuminance was 300 mW / cm 2 , and the cumulative light quantity was 3000 mJ / cm 2It was irradiated with ultraviolet rays under the conditions described above. After aging this at 50 °C for 48 hours, in an environment of 23 °C and 50% RH, using a tensile testing machine (manufactured by Minebea Co., Ltd., universal tensile and compression testing machine, apparatus name "Tensile and Compression Testing Machine, TCM-1kNB"), the peel strength was measured when peeling the above test piece from the above glass plate under the conditions of a peel angle of 180 degrees and a tensile speed of 60 mm / min. The measurement was performed three times, and Tables 1 and 2 show the arithmetic mean values thereof.

[0156] In addition, when measuring the haze value of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheets according to Examples 1, 6, 8, and 11 by the above method, all of them were 0.5% or less. The pressure-sensitive adhesive layers of the pressure-sensitive adhesive sheets of Examples 6 and 8 showed particularly good transparency.

[0157] [Table 1]

[0158] [Table 2]

[0159] In addition, the photo-reactive monomers used in Examples 1 to 13 are as follows. In Tables 1 and 2, each photo-reactive monomer is shown by an abbreviation. DPHA: Dipentaerythritol hexaacrylate (Shin-Nakamura Chemical Co., Ltd., trade name "A-DPH", functional group equivalent 96) A-DCP: Tricyclodecane dimethanol diacrylate (Shin-Nakamura Chemical Co., Ltd., trade name "A-DCP", functional group equivalent 152) #540: Bisphenol A diglycidyl ether acrylate adduct (Osaka Organic Chemical Industry Co., Ltd., trade name "Biscoat #540", functional group equivalent 250) R115F: Bisphenol A diglycidyl ether acrylate adduct (Nippon Kayaku Co., Ltd., trade name "KAYARAD R-115F", functional group equivalent 450) #700HV: Bisphenol A ethylene oxide 3.8 mol adduct diacrylate (Osaka Organic Chemical Industry Co., Ltd., trade name "Biscoat #700HV", functional group equivalent 350) E3703: Amine-modified bisphenol A type epoxy diacrylate (Daicel Ornex, trade name "EBECRYL 3703", functional group equivalent 425) APG400: Polypropylene glycol #400 diacrylate (Shin-Nakamura Chemical Co., Ltd., trade name "APG-400", functional group equivalent 268)

[0160] The pressure-sensitive adhesive sheets of Examples 1 to 9 shown in Table 1 were excellent in deformation resistance due to their high tensile elastic modulus and showed high impact resistance. On the other hand, the pressure-sensitive adhesive sheets of Examples 10, 12, and 13 shown in Table 2 had low deformation resistance, and the pressure-sensitive adhesive sheet of Example 11 had low peel strength.

[0161] As described above, specific examples of the present invention have been described in detail, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

Explanation of reference numerals

[0162] 1, 2 Pressure-sensitive adhesive sheet 10 Adhesive layer 10A One surface (adhesive surface) 10B The other surface 20 Support 20A First surface 20B Second surface (back surface) 30, 31, 32 Release liner 50 Pressure-sensitive adhesive sheet with release liner 70 Film member 100 Member with pressure-sensitive adhesive sheet

Claims

1. An adhesive sheet including an adhesive layer, The elastic modulus measured by the following tensile test is 3.0 MPa or more, and the impact resistance measured by the following shear impact test is 2.0 J / (10 mm). ２ The above-mentioned pressure-sensitive adhesive sheet. [Tensile test] The pressure-sensitive adhesive layer is irradiated with ultraviolet rays under the conditions of an illuminance of 300 mW / cm ２ and an integrated light quantity of 3000 mJ / cm ２ . After aging at 50°C for 48 hours, the pressure-sensitive adhesive layer is cut into a size of 10 mm in width and 150 mm in length to prepare a test piece. In an environment of 23°C and 50% RH, a tensile test of the test piece is performed using a tensile testing machine under the conditions of a chuck distance of 120 mm and a tensile speed of 50 mm / min to obtain a stress-displacement curve, and the elastic modulus [MPa] is calculated from the initial slope thereof. [Shear impact test] A shear impact test is conducted using a pendulum-type adhesive shear impact testing machine based on JIS K6855. As the measurement sample, after bonding the first surface of the adhesive layer with a size of 10 mm square to the central part of a chemically strengthened glass plate with a size of 25 mm square and a thickness of 1.7 mm, the second surface of the adhesive layer is attached to the central part of a stainless steel plate (SUS304BA plate) with a size of 40 mm square and crimped with a 5 N weight for 10 seconds. Then, autoclave treatment (50 °C, 0.5 MPa, 15 minutes) is performed, and the sample is irradiated with ultraviolet rays from the glass plate side under the conditions of an illuminance of 300 mW / cm ２ , an integrated light quantity of 3000 mJ / cm ２ . After that, a sample that has been aged at 50 °C for 48 hours is used. Fix the measurement sample so that the stainless steel plate is on the lower side, and measure the absorbed energy [J] when a hammer is applied to the outer peripheral side surface of the glass plate under the conditions of a hammer energy of 2.75 J and a hammer speed of 3.5 m / s in an environment of 23 °C and 50% RH, thereby obtaining the impact resistance [J / (10 mm) ２ .

2. The adhesive sheet according to claim 1, wherein the peel strength measured by the following peel test is 1.0 N / 10 mm or more. [Peel test] A test piece prepared by cutting the adhesive sheet to a size of 10 mm in width and 150 mm in length was pressure-bonded to a glass plate by passing a 2 kg rubber roller once, and after autoclave treatment (50 °C, 0.5 MPa, 15 minutes), the illuminance was 300 mW / cm from the glass plate side ２ , and ultraviolet rays were irradiated under the conditions of an integrated light quantity of 3000 mJ / cm ２ . After aging this at 50 °C for 48 hours, the peel strength when peeling the test piece from the glass plate was measured using a tensile tester under the conditions of a peel angle of 180 degrees and a tensile speed of 60 mm / min in an environment of 23 °C and 50% RH.

3. The adhesive sheet according to claim 1 or 2, wherein the adhesive layer contains a polymer (A) and a photo-reactive monomer (B).

4. The adhesive sheet according to claim 3, wherein the photo-reactive monomer (B) includes a compound B1 having a ring structure and two or more ethylenically unsaturated groups in the molecule.

5. The adhesive sheet according to claim 4, wherein the compound B1 has a molecular weight of 100 g / mol or more per ethylenically unsaturated group.

6. An adhesive sheet including an adhesive layer, wherein the adhesive layer contains a polymer (A) and a photo-reactive monomer (B), the photo-reactive monomer (B) includes a compound B1 having a ring structure and two or more ethylenically unsaturated groups in the molecule, and the compound B1 has a molecular weight of 100 g / mol or more per ethylenically unsaturated group.

7. The adhesive sheet according to claim 6, wherein the elastic modulus measured by the following tensile test is 3.0 MPa or more. [Tensile test] The adhesive layer is irradiated with ultraviolet rays under the conditions of an illuminance of 300 mW / cm ２ and an integrated light quantity of 3000 mJ / cm ２ . After aging at 50°C for 48 hours, the adhesive layer is cut into a size of 10 mm in width and 150 mm in length to prepare a test piece. In an environment of 23°C and 50% RH, a tensile test of the test piece is carried out using a tensile testing machine under the conditions of a chuck distance of 120 mm and a tensile speed of 50 mm / min to obtain a stress-displacement curve, and the elastic modulus is calculated from the initial slope thereof.

8. The adhesive sheet according to claim 6 or 7, wherein the impact resistance measured by the following shear impact test is 2.0 J / (10 mm) or more. ２ ​ [Shear impact test] A shear impact test is performed using a pendulum-type adhesive shear impact testing machine based on JIS K6855. As the measurement sample, after bonding the first surface of the adhesive layer with a size of 10 mm square to the central part of a chemically strengthened glass plate with a size of 25 mm square and a thickness of 1.7 mm, the second surface of the adhesive layer is attached to the central part of a stainless steel plate (SUS304BA plate) with a size of 40 mm square and crimped with a 5 N weight for 10 seconds. Then, autoclave treatment (50 °C, 0.5 MPa, 15 minutes) is carried out, and ultraviolet rays are irradiated from the glass plate side under the conditions of an illuminance of 300 mW / cm ２ , an integrated light quantity of 3000 mJ / cm ２ . After that, the sample that has been aged at 50 °C for 48 hours is used. Fix the measurement sample so that the stainless steel plate is on the lower side, and in an environment of 23°C and 50% RH, measure the absorption energy [J] when a hammer is applied to the outer peripheral side surface of the glass plate under the conditions of a hammer energy of 2.75 J and a hammer speed of 3.5 m / s, thereby obtaining the impact resistance [J / (10 mm ２ .

9. An adhesive sheet-attached film member including the adhesive sheet according to any one of claims 1 to 8 and a film member joined to the adhesive layer.

10. A method for manufacturing a laminate, including bonding the adhesive sheet according to any one of claims 1 to 8 to an adherend, and irradiating the adhesive sheet with ultraviolet rays to photocure the adhesive layer, in this order.

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