Adhesive sheets and their uses

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 widely used in various fields typically 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 their applications. Among those characteristics, there are some that are difficult to achieve at a high level, such as a tendency for one characteristic to deteriorate when attempting to improve another characteristic. 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 "resistance to deformation") and a property of withstanding impact and maintaining bonding with an 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 resistance to deformation 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. [[ID=X]] [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 carried out 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 carried out using a pendulum-type adhesive shear impact testing machine 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 carried out. After irradiating with ultraviolet rays 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. The above measurement sample is fixed with the stainless steel plate facing downwards, and the absorbed energy [J] is measured when a hammer is struck against the outer surface of the glass plate under the conditions of hammer energy 2.75J and hammer speed (impact velocity) 3.5m / sec in an environment of 23℃ and 50%RH, thereby determining the impact resistance [J / (10mm)]. 2 Find the answer to ].

[0007] By satisfying the above characteristic (a), the adhesive layer can exhibit high deformation resistance in the usage state of the adhesive sheet, for example. Since an 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 purposes such as joining and fixing members.

[0008] Furthermore, this specification provides an adhesive sheet comprising an adhesive layer, wherein the adhesive layer contains a polymer (A) and a photoreactive monomer (B). In some embodiments of the adhesive sheet, the photoreactive monomer (B) comprises a compound B1 having a ring structure and two or more ethylenically unsaturated groups in its molecule. It is preferable that the molecular weight of compound B1 per ethylenically unsaturated group is 100 g / mol or more. With an adhesive sheet having such an adhesive layer, a bond with high deformation resistance and high impact resistance can be suitably formed.

[0009] An adhesive sheet according to any embodiment disclosed herein may satisfy the following characteristic (c). An adhesive sheet satisfying characteristic (c) may be preferably used for purposes such as joining or fixing members. (c) The peel strength measured by the following peel test is 1.0 N / 10 mm or greater. [Peel test] The first surface of the adhesive layer described above is pressed onto a glass plate by rolling a 2kg rubber roller back and forth once, then autoclaved (50°C, 0.5MPa, 15 minutes), and then exposed to an illuminance of 300mW / cm² from the glass plate side. 2 , cumulative light intensity 3000 mJ / cm 2The sample is irradiated with ultraviolet light under the specified conditions. After aging at 50°C for 48 hours, the peel strength is measured when peeling the test piece from the glass plate using a tensile testing machine 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.

[0010] This specification provides an adhesive sheet-attached film member comprising an adhesive sheet as disclosed herein and a film member bonded to the adhesive layer of the adhesive sheet. The adhesive sheet-attached film member can suitably form a bond that is highly resistant to deformation and impact.

[0011] This specification provides a method for manufacturing a laminate, comprising, in this order, bonding one of the adhesive sheets disclosed herein to a substrate, and then irradiating the adhesive sheet with ultraviolet light to photocur the adhesive layer. This method makes it possible to manufacture a laminate that suitably achieves both impact resistance and high deformation resistance.

[0012] Furthermore, combinations of the above-mentioned elements may also be included within the scope of the invention for which patent protection is sought in this patent application. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic cross-sectional view showing the structure of an adhesive sheet according to one embodiment. [Figure 2] This is a schematic cross-sectional view showing the structure of an adhesive sheet according to another embodiment. [Figure 3] This is a schematic cross-sectional view showing a film member with an adhesive sheet attached, in which an adhesive sheet according to one embodiment is attached to a film member. [Modes for carrying out the invention]

[0014] Preferred embodiments of the present invention are described below. Matters other than those specifically mentioned herein but necessary for carrying out the present invention can be understood by those skilled in the art based on the teachings on carrying out the invention described herein and the common technical knowledge at the time of filing. The present invention can be carried out based on the contents disclosed herein and the common technical knowledge in the art. Furthermore, in the following drawings, components and parts that perform the same function may be denoted by the same reference numerals and described accordingly, and redundant descriptions may be omitted or simplified. Also, the embodiments shown in the drawings are schematic for the purpose of clearly illustrating the present invention and do not necessarily accurately represent the size or scale of the actual product provided.

[0015] In this specification, "acrylic polymer" refers to a polymer derived from a monomer component containing more than 50% by weight of acrylic monomers, and is also called an acrylic polymer. The above-mentioned acrylic monomer refers to a monomer having at least one (meth)acryloyl group in one molecule. In this specification, "(meth)acryloyl" comprehensively refers to acryloyl and methacryloyl. Similarly, "(meth)acrylate" comprehensively refers to acrylate and methacrylate, and "(meth)acrylic" comprehensively refers to acrylic and methacrylic. In this specification, "mass" and "weight" shall be considered synonymous.

[0016] In this specification, "photoreactive monomer" is a compound having at least one functional group (photoreactive functional group) in its molecule that can undergo a reaction upon irradiation with light, and is typically a compound having at least one ethylenically unsaturated group in its molecule as the above-mentioned photoreactive functional group. The photoreactive monomer referred to herein can be any monomer that can undergo a reaction, and may, for example, be a polymer such as an oligomer or polymer (for example, a polymer having at least one ethylenically unsaturated group in its molecule).

[0017] <Example of adhesive sheet configuration> Figure 1 shows an example of the configuration of the adhesive sheet disclosed herein. This adhesive sheet 1 is configured as a single-sided adhesive sheet (single-sided adhesive sheet with support) including an adhesive layer 10 on which one surface 10A is the surface to be attached to the adherend (adhesive surface), and a support 20 laminated on the other surface 10B of the adhesive layer 10. The adhesive layer 10 is bonded to one surface 20A of the support 20. As the support 20, for example, a resin film such as a polyester film may be used. The support 20 may also be an optical film such as a polarizing plate. In the example shown in Figure 1, the adhesive layer 10 has a single-layer structure. Before use (before being attached to the adherend), the adhesive sheet 1 may be in the form of an adhesive sheet 50 with a release liner, where the adhesive surface 10A is protected by a release liner 30 on which at least the adhesive layer side is a release surface (release surface), as shown in Figure 1. Alternatively, the second surface 20B of the support 20 (the surface opposite to the first surface 20A, also called the back surface) may be a release surface, and the adhesive surface 10A may be protected by winding or laminating the support 20 so that it comes into contact with the second surface 20B.

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

[0019] The adhesive sheet disclosed herein may be a supportless double-sided adhesive sheet comprising an adhesive layer. As shown in Figure 2, the supportless double-sided adhesive sheet 2 may be in a form in which, before use, each surface 10A, 10B of the adhesive layer 10 is protected by release liners 31, 32, at least on the side facing the adhesive layer, which is a release surface (release surface). Alternatively, the back surface of the release liner 31 (the surface opposite to the adhesive side) may be the release surface, and the adhesive surfaces 10A, 10B may be protected by winding or laminating so that the adhesive surface 10B abuts against the back surface of the release liner 31. Such a supportless double-sided adhesive sheet can be used, for example, by joining a support to either surface of the adhesive layer. Furthermore, the adhesive sheet disclosed herein may be in the form of a double-sided adhesive sheet with a support, wherein an adhesive layer is laminated on one surface and the other surface of a sheet-like support. In such an adhesive sheet, the support may be, for example, a resin film such as a polyester film, or an optical film such as a polarizing plate.

[0020] The adhesive sheet disclosed herein may be a component of an adhesive sheet-attached film member in which a film member is bonded to one surface of an adhesive layer. For example, the adhesive sheet 1 shown in Figure 1 may be a component of an adhesive sheet-attached film member 100 in which a film member 70 is bonded to one surface 10A of an adhesive layer 10, as shown in Figure 3. The film member may be, for example, an electromagnetic wave-transmitting metallic glossy member as described in Japanese Patent Application Publication No. 2018-69462, a polarizing plate, or other optical film.

[0021] <Characteristics of adhesive sheets> (Tensile modulus of elasticity) The adhesive sheet disclosed herein preferably has an adhesive layer (which may be an adhesive layer formed using any of the adhesive compositions disclosed herein) with a tensile modulus of 3.0 MPa or higher. The tensile modulus is measured by the tensile test described above, and more specifically by the method described in the examples below. Adhesive layers with a higher tensile modulus tend to exhibit better deformation resistance. The adhesive sheet with a high tensile modulus can be preferably used for purposes such as joining and fixing members. For example, in a laminate in which a member and an adherend are joined via an adhesive layer, high deformation resistance of the adhesive layer can help maintain the relative position of the member with respect to the adherend with good accuracy. Also, in a laminate in which a film member and an adherend are joined via an adhesive layer, high deformation resistance of the adhesive layer can help suppress the phenomenon in which the appearance of the laminate changes due to localized pressure from the film member side. In a laminate in which the adherend is a transparent rigid member (e.g., a glass member), suppressing changes in appearance visible from the adherend side is particularly significant.

[0022] In some preferred embodiments of the adhesive sheet, the tensile modulus may be, for example, 5.0 MPa or higher, 7.0 MPa or higher, 10.0 MPa or higher, 15.0 MPa or higher, or 20.0 MPa or higher. Deformation resistance tends to improve with increasing tensile modulus. There is no particular upper limit to the tensile modulus. From the viewpoint of easily balancing with other properties (e.g., one or more properties selected from impact resistance, peel strength, haze value, etc.), the tensile modulus is usually advantageous to be 150 MPa or lower, preferably 120 MPa or lower, but may also be 100 MPa or lower, 80 MPa or lower, or 60 MPa or lower. The tensile modulus can be adjusted by selecting the composition of the adhesive layer, etc.

[0023] In addition, in the above tensile test, the treatment of irradiating the adhesive layer with ultraviolet rays is preferably performed in a state where the adhesive layer is sandwiched between transparent release liners. From the viewpoint of transparency, as the release liner, a polyester 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 adhesive layer constituting the adhesive sheet disclosed herein. For example, when the thickness of the adhesive layer constituting the adhesive sheet is relatively small, for the purpose of improving operability, etc., the result 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 adhesive layer. The thickness of the test piece can be adjusted, for example, by appropriately overlapping the adhesive layers before ultraviolet irradiation. Also, using the same adhesive composition as that used for forming the adhesive layer to be measured, a test piece having a thickness suitable for performing a tensile test is prepared, and the result obtained by performing the above tensile test on the test piece can be adopted as the tensile elastic modulus of the 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 adhesive sheet disclosed herein has an impact resistance of 2.0 J / (10 mm) 2The above is preferable. The above impact resistance is measured by the shear impact test described above, and more specifically by the method described in the examples below. With the above impact-resistant adhesive sheet, a highly reliable bond can be formed. This can be an advantageous feature for adhesive sheets used, for example, for joining or fixing members. Such an adhesive sheet can withstand impacts such as drops or collisions and maintain a good bond between the member and the adherend.

[0026] In some preferred embodiments of adhesive sheets, the impact resistance is, for example, 2.1 J / (10 mm) 2 The above is sufficient, and 2.3J / (10mm) 2 The above is also acceptable, 2.5J / (10mm) 2 The above is also acceptable, 2.7J / (10mm) 2 The above is also acceptable, 3.0J / (10mm) 2 The above is also acceptable. The adhesive sheet disclosed herein has an impact resistance of 3.3 J / (10 mm) 2 Above or 3.5J / (10mm) 2 The above-mentioned embodiments may also be preferably implemented. The upper limit of the above impact resistance is not particularly limited. From the viewpoint of easily balancing with other characteristics, the above impact resistance is, for example, 20 J / (10 mm) 2 The following are acceptable: 15J / (10mm) 2 The following is also acceptable: 10J / (10mm) 2 The following is also acceptable: 8.0J / (10mm) 2 But often, 6.0J / (10mm) 2 The following are also acceptable. Impact resistance can be adjusted by selecting the composition and thickness of the adhesive layer, etc.

[0027] Furthermore, the adhesive sheets disclosed herein include embodiments without limitations on tensile modulus, and in such embodiments, the adhesive sheets are not limited to satisfying the above-mentioned tensile modulus. Similarly, the adhesive sheets disclosed herein include embodiments without limitations on impact resistance, and in such embodiments, the adhesive sheets are not limited to satisfying the above-mentioned impact resistance.

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

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

[0030] Here, "haze value" refers to the ratio of diffusely transmitted light to total transmitted light when visible light is shone on the object being measured. 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 was measured at an illuminance of 300 mW / cm². 2 , cumulative light intensity 3000 mJ / cm 2 The adhesive layer, after being irradiated with ultraviolet light under these conditions and aged at 50°C for 48 hours, can be used as a measurement sample and measured using a haze meter (for example, "MR-100" manufactured by Murakami Color Technology Laboratory). The haze value can be adjusted by selecting, for example, the composition and thickness of the adhesive layer. It is preferable that the treatment of irradiating the adhesive layer with ultraviolet light be carried out with the adhesive layer sandwiched between transparent release liners (for example, a release-treated PET film), similar to the tensile test in the measurement of tensile modulus of elasticity described above.

[0032] <Adhesive layer> The adhesive sheet in the technologies disclosed herein (including adhesive sheets, film members with adhesive sheets, and methods for manufacturing laminates; the same applies hereinafter) includes an adhesive layer. The configuration of the adhesive layer can be selected to form a bond that is highly resistant to deformation and impact.

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

[0034] The weight percentage of polymer (A) in the total weight of the adhesive layer is usually appropriate to be 40% by weight or more, preferably 50% by weight or more, and may also be 60% by weight or more, or 70% by weight or more, from the viewpoint of impact resistance and the like. In addition, the weight percentage of polymer (A) in the total weight of the adhesive layer is typically less than 100% by weight, and from the viewpoint of easily adjusting the balance of properties, it is usually advantageous to be 95% by weight or less, preferably 92% by weight or less, and may also be 90% by weight or less, or 87% by weight or less.

[0035] One preferred example of polymer (A) is an acrylic polymer. The adhesive layer in the technology disclosed herein may be an acrylic adhesive layer containing an acrylic polymer as the base polymer (the main component of the polymer components, i.e., the component accounting for more than 50% by weight). The acrylic polymer as polymer (A) (hereinafter sometimes referred to as "acrylic polymer (A)") is preferably an acrylic polymer composed of monomer components containing 40% by weight or more of an alkyl (meth)acrylate ester having a linear or branched alkyl group with 1 to 20 carbon atoms at the ester end. Hereinafter, alkyl (meth)acrylate esters having an alkyl group with X to Y carbon atoms at the ester end will be referred to as "(meth)acrylate C X-Y It is sometimes written as "alkyl ester".

[0036] In some embodiments, (meth)acrylic acid C is included in the entire monomer component of the acrylic polymer (A). 1-20 The proportion of alkyl esters is appropriately greater than 40% by weight, as it allows for a good balance of properties. For example, it may be 45% by weight or more, 50% by weight or more, 55% by weight or more, or 60% by weight or more. Among the monomer components, (meth)acrylic acid C 1-20The proportion of alkyl ester can be 100% by weight, but it is usually appropriate to be 98% by weight or less, for easier balance of properties, for example, 95% by weight or less, or even 90% by weight or less. In some embodiments, C is present in the total monomer component of the acrylic polymer (A). 1-20 The proportion of alkyl methacrylate may be, for example, 85% by weight or less, 80% by weight or less, 75% by weight or less, 70% by weight or less, 65% by weight or less, or 60% by weight or less, from the viewpoint of improving the cohesiveness of the adhesive layer.

[0037] (meth)acrylic acid C 1-20 Non-specific examples of alkyl esters 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, and i Examples include sooctyl, 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, and eicosyl (meth)acrylate.

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

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

[0040] In some embodiments, the monomer component constituting the acrylic polymer (A) is (meth)acrylic acid C 4-18 It may contain alkyl esters in a proportion of 40% by weight or more. (meth)acrylate C in the monomer component. 4-18 The proportion of alkyl ester may be, for example, 50% by weight or more, 60% by weight or more, or 65% by weight or more. Furthermore, from the viewpoint of improving the cohesiveness of the adhesive layer, (meth)acrylic acid C is included in the monomer component. 4-18 The proportion of alkyl esters is usually appropriate to be 99.5% by weight or less, but may also 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, optionally, include other monomers copolymerizable with the (meth)acrylate alkyl ester (copolymerizable monomers). Suitable copolymerizable monomers include monomers having polar groups (e.g., carboxyl groups, hydroxyl groups, nitrogen-containing rings, etc.) and monomers with relatively high glass transition temperatures (e.g., 10°C or higher) of the homopolymer. Monomers having polar groups can be useful for introducing crosslinking points into the acrylic polymer (A) or for increasing the cohesive strength of the adhesive. Copolymerizable monomers can be used individually or in combination of two or more.

[0042] Non-specific examples of 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. Monomers containing acid anhydride groups: For example, maleic anhydride, itaconic anhydride. Hydroxypropyl 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, hydroxyalkyl (meth)acrylate such as (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, etc. Monomers containing sulfonic acid groups or phosphate groups: 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-ethyl glycidyl ether (meth)acrylate, allyl glycidyl ether, glycidyl (meth)acrylate, etc. Cyano group-containing monomers: for example, acrylonitrile, methacrylonitrile, etc. Monomers containing isocyanate groups: for example, 2-isocyanate ethyl (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; N-alkyl(meth)acrylamides such as N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-butyl(meth)acrylamide, Nn-butyl(meth)acrylamide; N-vinyl carboxylic acid amides such as N-vinylacetamide; monomers having a hydroxyl group and an amide group, for example, N-(2-hydroxyethyl)(meth)acrylamide N-hydroxyalkyl(meth)acrylamides such as 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, and N-(4-hydroxybutyl)(meth)acrylamide; 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, and N-butoxymethyl(meth)acrylamide; and others such as N,N-dimethylaminopropyl(meth)acrylamide and N-(meth)acryloylmorpholine. Amino group-containing monomers: for example, aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate. Monomers containing epoxy groups: for example, glycidyl (meth)acrylate, methylglycidyl (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-vinyloxazole, N-(meth)acryloyl-2-pyrrolidone, N-(meth)acryloylpiperidine, N-(meth)acryloylpyrrolidone N-(meth)acryloylmorpholine, N-vinylmorpholine, N-vinyl-3-morpholinone, N-vinyl-2-caprolactam, N-vinyl-1,3-oxazin-2-one, N-vinyl-3,5-morpholindione, 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)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, N-(meth)acryloyl-8-oxyhexamethylenesuccinimide, etc. Maleimides: For example, N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide, etc. Itaconimides: For example, N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide, etc. (meth)acrylate aminoalkyls: for example, (meth)acrylate aminoethyl, (meth)acrylate N,N-dimethylaminoethyl, (meth)acrylate N,N-diethylaminoethyl, (meth)acrylate t-butylaminoethyl. Alkoxy group-containing monomers: For example, alkoxyalkyl (alkoxyalkyl (meth)acrylate) types such as 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, propoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, and ethoxypropyl (meth)acrylate; alkoxyalkylene glycol (e.g., alkoxypolyalkylene glycol (meth)acrylate) types such as methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, and methoxypolypropylene 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, and 3-(meth)acryloxypropylmethyldiethoxysilane, as well as alkoxysilyl group-containing vinyl compounds such as vinyltrimethoxysilane and 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. (Meth)acrylic acid esters having alicyclic hydrocarbon groups: For example, alicyclic hydrocarbon group-containing (meth)acrylates such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and adamantyl (meth)acrylate. (Meth)acrylic acid esters having aromatic hydrocarbon groups: for example, aromatic hydrocarbon group-containing (meth)acrylates such as phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, and benzyl (meth)acrylate. Other examples include heterocyclic (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate, halogen-containing (meth)acrylates such as vinyl chloride and fluorine-containing (meth)acrylates, silicon-containing (meth)acrylates such as silicone (meth)acrylate, and (meth)acrylic acid esters obtained from terpene compound derivative alcohols.

[0043] When using such copolymerizable monomers, the amount used is not particularly limited, but it is generally appropriate to use at least 0.01% by weight of the total monomer components. From the viewpoint of better demonstrating the effects of copolymerizable monomers, the amount used may be 0.1% by weight or more of the total monomer components, or 0.5% by weight or more. Furthermore, from the viewpoint of easily balancing the adhesive properties, it is generally appropriate to use 50% by weight or less of the total monomer components, and preferably 40% by weight or less.

[0044] In some embodiments, the monomer components constituting the acrylic polymer (A) may include monomers having nitrogen atoms. The use of monomers having nitrogen atoms can enhance the cohesive force of the adhesive and preferably improve the peel strength after photocuring. A suitable example of a monomer having nitrogen atoms is a monomer having a nitrogen atom-containing ring. Examples of monomers having a nitrogen atom-containing ring include those exemplified above, for example, general formula (1): [ka] An N-vinyl cyclic amide represented by can be used. Here, in general formula (1), R 1 -(CH2) is a divalent organic group, a specific example being -(CH2) n- are examples. Here, n is an integer between 2 and 7 (preferably 2, 3, or 4). Among these, N-vinyl-2-pyrrolidone can be preferably used. Other preferred examples of monomers having a nitrogen atom include amide group-containing monomers such as (meth)acrylamide.

[0045] The amount of monomer containing nitrogen atoms (preferably monomers having a nitrogen atom-containing ring) used is not particularly limited, and may be, for example, 1% or more by weight of the total monomer component, 3% or more by weight, or even 5% or more by weight or 7% or more by weight. In one embodiment, the amount of monomer containing nitrogen atoms used may be 10% or more by weight of the total monomer component, 15% or more by weight, or 20% or more by weight. Also, it is appropriate to use 40% or less by weight of the total monomer component, for example, but may be 35% or less by weight, 30% or less by weight, or 25% or less by weight. In another embodiment, the amount of monomer containing nitrogen atoms used may be 20% or less by weight of the total monomer component, for example, or 15% or less by weight.

[0046] In some embodiments, the monomer components constituting the acrylic polymer (A) may include hydroxyl group-containing monomers. The use of hydroxyl group-containing monomers can suitably adjust the cohesive force and degree of crosslinking (e.g., crosslinking with isocyanate crosslinking agents) of the adhesive. The amount of hydroxyl group-containing monomer used 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. Furthermore, from the viewpoint of suppressing the water absorption of the adhesive layer, in some embodiments, the amount of hydroxyl group-containing monomer used may be, for example, 40% by weight or less of the total monomer component, for example, 30% by weight or less, 25% by weight or less, or 20% by weight or less. In another embodiment, the amount of hydroxyl group-containing monomer used may be, for example, 15% by weight or less of the total monomer component, for example, 10% by weight or less, or 5% by weight or less.

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

[0048] In some embodiments, the monomer components constituting the acrylic polymer (A) may include alicyclic hydrocarbon group-containing (meth)acrylate. This can enhance the cohesive force of the adhesive and improve the peel strength after photocuring. Examples of alicyclic hydrocarbon group-containing (meth)acrylates can be those exemplified above, and for example, cyclohexyl acrylate and isobornyl acrylate are preferably used. When using alicyclic hydrocarbon group-containing (meth)acrylate, the amount used is not particularly limited and can be, for example, 1% or more by weight, 3% or more by weight, or 5% or more by weight of the total monomer components. In one embodiment, the amount of alicyclic hydrocarbon group-containing (meth)acrylate used may be 10% or more by weight of the total monomer components, or 15% or more by weight. The upper limit of the amount of alicyclic hydrocarbon group-containing (meth)acrylate used is appropriately about 40% or less by weight, for example, it may be 30% or less by weight, or 25% or less by weight (for example, 15% or less by weight, and even 10% or less by weight).

[0049] The polymerization method used to form (synthesize) polymer (A) from monomer components is not particularly limited, and various conventionally known polymerization methods can be appropriately employed. For example, polymerization methods such as thermal polymerization (typically carried out in the presence of a thermal polymerization initiator), including solution polymerization, emulsion polymerization, and bulk polymerization; photopolymerization (typically carried out in the presence of a photopolymerization initiator), which is performed by irradiation with light such as ultraviolet light; and radiation polymerization (typically carried out by irradiation with radiation such as beta rays and gamma rays) can be appropriately employed. Two or more polymerization methods may also be combined (for example, in steps).

[0050] For solution polymerization, one solvent or a mixture of two or more solvents can be used as the solvent (polymerization solvent), 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 (e.g., monohydric alcohols with 1 to 4 carbon atoms); ethers such as tert-butyl methyl ether; ketones such as methyl ethyl ketone; etc.

[0051] In polymerization, known or conventional thermal polymerization initiators or photopolymerization initiators may be used depending on the polymerization method and polymerization mode. Such polymerization initiators can be used individually or in appropriate combinations of two or more.

[0052] While not particularly limited, the following can be used as thermal polymerization initiators: azo polymerization initiators, peroxide initiators, redox initiators using a combination of peroxide and reducing agent, substituted ethane initiators, etc. More specifically, for example, 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'-dimethyleneisobutylamidine), 2,2'-azobis[N-(2-carboxyethyl)-2- Examples of azo initiators include methylpropionamidine hydrate; persulfates such as potassium persulfate and ammonium persulfate; peroxide initiators such as benzoyl peroxide, t-butyl hydroperoxide, and hydrogen peroxide; substituted ethane initiators such as phenyl-substituted ethane; and redox initiators such as combinations of persulfates and sodium bisulfite, or peroxides and sodium ascorbate; but are not limited to these. Thermal polymerization can preferably be carried out at a temperature of, for example, 20 to 100°C (typically 40 to 80°C), but is not limited to this.

[0053] While not particularly limited, the following can be used as photopolymerization initiators: ketal-based photopolymerization initiators, acetophenone-based photopolymerization initiators, benzoin ether-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, and the like.

[0054] The amount of polymerization initiator used can be the usual amount depending on the polymerization method and polymerization mode, and is not particularly limited. For example, approximately 0.001 to 5 parts by weight (typically approximately 0.01 to 2 parts by weight, for example, approximately 0.01 to 1 part by weight) of polymerization initiator can be used per 100 parts by weight of the monomer to be polymerized.

[0055] For the above polymerization, various conventionally known chain transfer agents (which may also be known as molecular weight modifiers or degree of polymerization modifiers) can be used as needed. As chain transfer agents, mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan, thioglycolic acid, and α-thioglycerol can be used. Alternatively, chain transfer agents that do not contain sulfur atoms (non-sulfur chain transfer agents) may be used. Specific examples of non-sulfur chain transfer agents 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 benzylidenyl group such as dibenzylideneacetone, cinnamyl alcohol, and cinnamylaldehyde; 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; and benzyl hydrogens such as diphenylbenzene and triphenylbenzene. Chain transfer agents can be used individually or in combination of two or more. The technology disclosed herein can also be preferably implemented in a form that does not use chain transfer agents.

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

[0057] In the technologies disclosed herein, the glass transition temperature (Tg) of polymer (A) is not particularly limited, but is usually suitable to be below 0°C, preferably below -10°C, and preferably below -20°C. The impact resistance tends to improve as the Tg of polymer (A) decreases. In some embodiments, the Tg of polymer (A) may be below -25°C or below -30°C. Also, the Tg of polymer (A) is typically -80°C or higher, for example, it may be -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 polymer (A) is preferably -50°C or higher, more preferably -45°C or higher, may be -40°C or higher, may be -38°C or higher, or may be -35°C or higher.

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

[0059] In Fox's equation above, Tg represents the glass transition temperature of the copolymer (unit: K), Wi represents the weight fraction of monomer i in the copolymer (weight-based copolymerization ratio), and Tgi represents the glass transition temperature of the monomer i homopolymer (unit: K). If the polymer for which Tg is to be specified is a homopolymer, the Tg of the homopolymer and the Tg of the target polymer are the same.

[0060] The glass transition temperature of the homopolymer used in calculating Tg shall be the value specified in publicly available documents. For example, for the monomers listed below, the following values ​​shall be used as the glass transition temperature of the homopolymer of the monomer. n-butyl acrylate -55℃ Isostearyl acrylate -18℃ Cyclohexyl acrylate 15℃ N-vinyl-2-pyrrolidone 54℃ 4-Hydroxybutyl acrylate -40℃

[0061] For the glass transition temperatures of monomer homopolymers other than those exemplified above, the values ​​listed in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) shall be used. If multiple values ​​are listed in this document, 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 The above is appropriate, 20 × 10 4 It is preferable that it be greater than 30 × 10 4 Super is fine, 40 x 10 4 Super is fine, 50 x 10 4 It can also be super. Also, the upper limit of Mw for polymer (A) is usually approximately 500 × 10 4 The following is possible. In some embodiments, from the viewpoint of adhesion to the adherend and peel strength, the Mw of polymer (A) is, for example, 150 × 10 4 The following may be true: 100 × 10 4 The following is also acceptable: 90 x 10 4 The following is also acceptable: 75 x 10 4 The following is also acceptable. Here, Mw refers to the value obtained by gel permeation chromatography (GPC) on a standard polystyrene basis. As the GPC apparatus, for example, the model name "HLC-8320GPC" (column: TSKgelGMH-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 adhesive layer of the adhesive sheet disclosed herein, or to the Mw of polymer (A) in the adhesive composition used to form the adhesive layer.

[0063] (Photoreactive monomer (B)) The adhesive layer in the technology disclosed herein may include a photoreactive monomer (B) in addition to the polymer (A) described above (for example, an acrylic polymer (A)). As the photoreactive monomer (B), a compound having two or more ethylenically unsaturated groups (hereinafter also referred to as "number of functional groups") in the molecule can be used. There is no particular upper limit to the number of functional groups of the compound used as the photoreactive monomer (B). 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 number of functional groups of, for example, 2 to 10 can be used, preferably a compound with a number of functional groups of 2 to 8, and more preferably a compound with a number of functional groups of 2 to 6. 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 ethylenically unsaturated groups with light (e.g., ultraviolet light) after application to the substrate. An adhesive sheet containing the photoreactive monomer (B) in the adhesive layer can have its deformation resistance improved by curing the adhesive layer with ultraviolet light after application to the substrate. This allows for a favorable balance between good conformability to the surface shape of the substrate during application and high deformation resistance after application.

[0065] The above examples of ethylenically unsaturated groups include, but are not limited to, acryloyl, methacryloyl, vinyl, and allyl groups. The two or more ethylenically unsaturated groups in the photoreactive monomer (B) may be the same group or two or more different groups. From the viewpoint of photoreactivity, preferred ethylenically unsaturated groups include acryloyl and methacryloyl groups. Among these, acryloyl groups are preferred.

[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, about 50 to 8,000 g / mol, about 50 to 5,000 g / mol, about 50 to 3,000 g / mol, or about 50 to 2,000 g / mol. In some embodiments, from the viewpoint of photocurability, 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 as the photoreactive monomer (B).

[0067] The functional group equivalent of photoreactive monomer (B) is calculated by dividing the molecular weight [g / mol] of photoreactive monomer (B) by the number of ethylene unsaturated functional groups it possesses. The molecular weight of photoreactive monomer (B) can be obtained, for example, by gel permeation chromatography (GPC) as the weight-average molecular weight on a standard polystyrene basis. Alternatively, the molecular weight [g / mol] of photoreactive monomer (B) may be the manufacturer's stated value or the molecular weight calculated from the molecular structure.

[0068] The molecular weight of the photoreactive monomer (B) is not particularly limited and can be selected so as to suitably exhibit the desired effect. For example, a photoreactive monomer (B) with a molecular weight of approximately 20,000 or less can be used. From the viewpoint of ease of preparation and coating properties of the adhesive composition, in some embodiments, the molecular weight of the photoreactive monomer (B) may be, for example, 16,000 or less, 10,000 or less, 4,000 or less, 1,500 or less, or 1,000 or less. The molecular weight of the photoreactive monomer (B) is, for example, 100 or more, and is typically 120 or more. From the viewpoint of processability and handling properties of the adhesive sheet, in some embodiments, the molecular weight of the photoreactive monomer (B) may be, for example, 150 or more, 200 or more, 280 or more, 350 or more, 420 or more, 480 or more, or 550 or more.

[0069] In the adhesive sheet disclosed herein, the amount of photoreactive monomer (B) contained in the adhesive layer is not particularly limited and can be appropriately set according to the target performance (e.g., the tensile modulus of the adhesive layer after photocuring). In some embodiments in which the adhesive layer contains a polymer (A) and a photoreactive monomer (B), the amount of photoreactive monomer (B) per 100 parts by weight of polymer (A) contained in the adhesive layer may be, for example, 1 part by weight or more, and is usually appropriate to be 3 parts by weight or more. From the viewpoint of making it easier to increase the tensile modulus of the adhesive layer after photocuring, the amount of photoreactive monomer (B) per 100 parts by weight of 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. Furthermore, from the viewpoint of the cohesiveness of the adhesive layer before photocuring and the handling (e.g., processability) of the adhesive sheet, the amount of photoreactive monomer (B) per 100 parts by weight of polymer (A) is usually appropriate to be 80 parts by weight or less, preferably 60 parts by weight or less, and may also be 50 parts by weight or less, 40 parts by weight or less, or 35 parts by weight or less.

[0070] In some embodiments, the adhesive layer preferably contains at least a compound B1 as the photoreactive monomer (B), which has a ring structure and two or more ethylenically unsaturated groups in its molecule. An adhesive layer containing a compound B1 with such a structure can effectively increase the deformation resistance of the adhesive layer upon light irradiation. The ring in the ring structure may be an aliphatic ring or an aromatic ring. The ring may also be a carbon ring or a heterocycle. The number of rings contained in one molecule of compound B1 may be one or two or more. There is no particular upper limit to the number of rings contained in compound B1; for example, it may be 100 or less, 70 or less, 50 or less, 30 or less, 15 or less, 8 or less, 6 or less, 5 or less, or 4 or less. If compound B1 contains two or more rings, these rings may or may not form a fused ring (typically a bicyclic or tricyclic fused ring) with one or more rings. The above-mentioned ring is preferably included in the main chain of compound B1. That is, it is preferable that one ethylenically unsaturated group of compound B1 and at least one other ethylenically unsaturated group are linked via the above-mentioned ring structure. Compound B1 can be used alone or in combination of two or more types.

[0071] As compound B1, a compound having a ring structure and two or more ethylenically unsaturated groups in its molecule, and having a functional group equivalent of 100 g / mol or more, can preferably be used. An adhesive sheet containing compound B1 satisfying the above functional group equivalent in the adhesive layer can suitably form a bond with high deformation resistance and high impact resistance. The reason for obtaining such effects is not to be interpreted in a particularly restrictive way, but it is thought that compound B1 can effectively increase the tensile modulus of the adhesive layer after light irradiation due to the rigidity of the ring structure, thereby providing deformation resistance, while the functional group equivalent of compound B1 being above a predetermined level maintains the distance between crosslinking points, thereby forming a crosslinked structure with high impact resistance. In some embodiments, the functional group equivalent of 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. Impact resistance tends to improve with increasing functional group equivalent of compound B1. The functional group equivalent of compound B1 may be, for example, 10,000 g / mol or less, 8,000 g / mol or less, 5,000 g / mol or less, 3,000 g / mol or less, or 2,000 g / mol or less. In some embodiments, from the viewpoint of photocurability, etc., the functional group equivalent of 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 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 in compound B1 (i.e., 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, compound B1 having 2 functional groups may be preferred.

[0073] Compound B1 may have functional groups other than ethylenically unsaturated groups. Examples of functional groups other than ethylenically unsaturated groups include hydroxyl groups, carboxyl groups, and amino groups. Preferred examples of functional groups other than ethylenically unsaturated groups include hydroxyl groups and amino groups.

[0074] Examples of compound B1 include bisphenol A type epoxy (meth)acrylates such as bisphenol A glycidyl ether (meth)acrylic acid adduct, bisphenol A glycidylamine (meth)acrylic acid adduct, and bisphenol A glycidyl ester (meth)acrylic acid adduct; 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 adduct, bisphenol F glycidylamine (meth)acrylic acid adduct, and bisphenol F glycidyl ester (meth)acrylic acid adduct; 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 glycidyl ether (meth)acrylic acid adduct, and bisphenol E Bisphenol E type epoxy (meth)acrylates such as glycidylamine (meth)acrylate adducts and bisphenol E glycidyl ester (meth)acrylate 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; 9,9-bis(4-hydroxyphenyl)full orange (meth)acrylate, 9,9-bis[4-(2-hydroxyethoxy)phenyl]full orange (meth)acrylate (Meth)acrylates containing a fluorene skeleton, such as rilate; 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 phthalate type epoxy(meth)acrylate, hydrogenated terpenephenol(meth)acrylate, 1,4-cyclohexanedimethanol diglycidyl ether(meth)acrylate, etc., which may be aliphatic rings (or alicyclic condensed rings).Examples of (meth)acrylates having ); (meth)acrylic acid adducts of novolac-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 terpenephenol resins; isocyanurate-type (meth)acrylates such as tris(2-hydroxyethyl)isocyanurate di(meth)acrylate and tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate; divinylbenzene; hydroquinone di(meth)acrylate; resorcinol di(meth)acrylate; modified versions of any of the above materials (e.g., amine-modified, acid-modified, halogen-modified); etc., but not limited to these. In some embodiments, compound B1 having an aromatic carbon ring can be preferably used. Preferred examples of 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 (e.g., amine-modified products).

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

[0076] The amount of compound B1 per 100 parts by weight of polymer (A) contained in the adhesive layer is not particularly limited and can be, for example, 0.5 parts by weight or more. From the viewpoint of making it easier to obtain an adhesive layer that balances deformation resistance and impact resistance well, in some embodiments, the amount of compound B1 per 100 parts by weight of 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. Furthermore, from the viewpoint of the cohesiveness of the adhesive layer before photocuring and the handling of the adhesive sheet, the amount of compound B1 per 100 parts by weight of polymer (A) is usually appropriate to be 80 parts by weight or less, preferably 60 parts by weight or less, may be 50 parts by weight or less, may be 40 parts by weight or less, or may be 35 parts by weight or less.

[0077] In some embodiments, the adhesive layer may contain, as the photoreactive monomer (B), compound B2 having two or more functional groups and no ring structure within the molecule. Compound B2 is preferably used in combination with compound B1. This adjusts the crosslinking structure of the adhesive layer, making it possible to form a bond that more favorably balances deformation resistance and impact resistance. Compound B2 can be used alone or in combination of two or more types.

[0078] The number of functional groups in 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 in compound B2 may be, for example, 2 to 10, preferably 3 to 10, 3 to 8, or 4 to 6. For example, in embodiments where compound B1 is a compound with 2 functional groups, it may be advantageous to use compound B2 with 3 or more functional groups (preferably 4 or more, more preferably 5 or more, and even more preferably 6 or more).

[0079] The functional group equivalent of compound B2 is not particularly limited and may be, for example, 5000 g / mol or less, 2000 g / mol or less, or 1000 g / mol or less. In some embodiments, the functional group equivalent of compound B2 may be, for example, 600 g / mol or less, and 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 viewpoint of improving photocurability and 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, may be 70 g / mol or more, may be 80 g / mol or more, or may be 90 g / mol or more.

[0080] Examples of compounds that can be used as compound B2 include, but are not limited to, 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, hydroxypivalate neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, allyl(meth)acrylate, vinyl(meth)acrylate, EO-modified or PO-modified versions of any of the above materials, etc.

[0081] In embodiments using compound B2, the amount of compound B2 per 100 parts by weight of polymer (A) contained in the adhesive layer is not particularly limited and can be, for example, 0.1 parts by weight or more. From the viewpoint of making it easier to obtain an adhesive layer that balances deformation resistance and impact resistance well, in some embodiments, the amount of compound B2 per 100 parts by weight of polymer (A) may 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. Furthermore, from the viewpoint of suppressing a decrease in adhesion to the adherend due to excessive crosslinking, in some embodiments, the amount of compound B2 per 100 parts by weight of polymer (A) is, for example, suitable to be 25 parts by weight or less, preferably 17 parts by weight or less, may be 15 parts by weight or less, may be 13 parts by weight or less, or may be 9 parts by weight or less.

[0082] In embodiments where compound B1 and compound B2 are used in combination, compound B2 may preferably be a compound having 3 or more functional groups and having a smaller functional group equivalent than compound B1 used in combination with it. In some embodiments, the ratio of the functional group equivalent FE2 of compound B2 to the functional group equivalent FE1 of compound B1 (FE2 / FE1) may be, for example, 0.9 or less, 0.7 or less, 0.5 or less, or 0.4 or less. According to such embodiments, the tensile modulus improvement effect of the photoreactive monomer (B) can be efficiently exhibited. The lower limit of the above ratio (FE2 / FE1) is not particularly limited and may be, for example, 0.01 or more, 0.1 or more, or 0.2 or more.

[0083] In embodiments where compound B1 and compound B2 are used in combination, the weight ratio (W2 / W1) of the amount of compound B2 used W2 to the amount of compound B1 used W1 is not particularly limited. In some embodiments, the weight ratio (W2 / W1) may 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) to any of the above ranges, the effects of using compound B1 and compound B2 in combination tend to be favorably exhibited.

[0084] In some embodiments of the adhesive sheets disclosed herein, the photoreactive monomer (B) may be included in the adhesive layer in a free form. Such an adhesive layer can be suitably formed using an adhesive composition containing the photoreactive monomer (B) in a free form. Here, "free form" means that the photoreactive monomer (B) is not chemically bonded to other components (e.g., polymer (A)) contained in the adhesive layer or adhesive composition. Adhesive compositions containing the photoreactive monomer (B) in a free form may be advantageous in terms of ease of preparation and suppression of gelation.

[0085] In some other forms of the adhesive sheet disclosed herein, at least a portion of the photoreactive monomer (B) may be included in the adhesive layer in a form chemically bonded to other components (e.g., polymer (A), crosslinking agent described later) contained in the adhesive layer or adhesive composition, from the viewpoint of improving the processability of the adhesive sheet. The chemical bond may be, for example, a bond formed by the reaction of a functional group F1 other than an ethylenically unsaturated group that the photoreactive monomer (B) has in its molecule with a functional group F2 that has in the molecule of the other component and is reactable with the functional group F1. The other component may be a crosslinking agent, and the photoreactive monomer (B) may be bonded to polymer (A) via the crosslinking agent.

[0086] (Acrylic oligomers) The adhesive layer of the adhesive sheet disclosed herein may contain an acrylic oligomer for the viewpoint of improving cohesive force and adhesion to adjacent surfaces (for example, the surface of the support on the adhesive sheet, the surface of the object to which the adhesive sheet is attached, etc.). The adhesive layer containing the acrylic oligomer can preferably be formed using an adhesive composition containing the acrylic oligomer. As the acrylic oligomer, one having a higher Tg than the polymer (A) described above can preferably be used.

[0087] The Tg of the above acrylic oligomer is not particularly limited and may be, for example, between approximately 20°C and 300°C. The above Tg may be, for example, above approximately 30°C, above approximately 40°C, above approximately 60°C, above approximately 80°C, or above approximately 100°C. Generally, as the Tg of the acrylic oligomer increases, the effect of improving cohesive force tends to increase. Furthermore, from the viewpoint of anchoring ability to the support and shock absorption, the Tg of the acrylic oligomer may be, for example, below approximately 250°C, below approximately 200°C, below approximately 180°C, or below approximately 150°C. Note that the Tg of the acrylic oligomer is a value calculated based on Fox's formula, just like the Tg of polymer (A).

[0088] The Mw of the acrylic oligomer is not particularly limited and may be approximately 1000 or more, usually approximately 1500 or more is appropriate, may be approximately 2000 or more, or approximately 3000 or more. Furthermore, the Mw of the acrylic oligomer may be approximately less than 30000, usually approximately less than 10000 is appropriate, may be approximately less than 7000, or approximately less than 5000. When the Mw is within the above range, the effect of improving the cohesiveness of the adhesive layer and adhesion to adjacent surfaces is favorably exhibited. The Mw of the acrylic oligomer can be measured by gel permeation chromatography (GPC) and determined as a value equivalent to standard polystyrene. Specifically, for example, it can be measured using an HPLC8020 manufactured by Tosoh Corporation with two TSKgelGMH-H(20) columns and a flow rate of approximately 0.5 mL / min in tetrahydrofuran solvent.

[0089] Examples of monomer components that make up acrylic oligomers include the various (meth)acrylic acid C compounds mentioned above. 1-20 Examples of (meth)acrylate monomers include alkyl esters; various alicyclic hydrocarbon group-containing (meth)acrylates mentioned above; various aromatic hydrocarbon group-containing (meth)acrylates mentioned above; and (meth)acrylates obtained from terpene compound derivative alcohols. These can be used individually or in combination of two or more.

[0090] From the viewpoint of improving adhesion, it is preferable that acrylic oligomers contain relatively bulky acrylic monomers as monomer units, such as alkyl(meth)acrylates with branched alkyl groups like isobutyl(meth)acrylate and t-butyl(meth)acrylate; alicyclic hydrocarbon group-containing(meth)acrylates; and aromatic hydrocarbon group-containing(meth)acrylates. Furthermore, when ultraviolet light is used during the synthesis of acrylic oligomers or the preparation of adhesive layers, monomers having saturated hydrocarbon groups at the ester terminus are preferred because they are less likely to inhibit polymerization. For example, alkyl(meth)acrylates with branched alkyl groups and saturated alicyclic hydrocarbon group-containing(meth)acrylates can be suitably used.

[0091] The proportion of (meth)acrylate monomers in the total 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 (e.g., 80% by weight or more, and even more than 90% by weight or more). In one preferred embodiment, the acrylic oligomer has a monomer composition consisting substantially of only one or more (meth)acrylate monomers. For example, the monomer components constituting the acrylic oligomer may be an alicyclic hydrocarbon group-containing (meth)acrylate and (meth)acrylic acid C 1-20 When alkyl esters are included, their weight ratio is not particularly limited. In some embodiments, alicyclic hydrocarbon group-containing (meth)acrylate / (meth)acrylic acid C 1-20 The weight ratio of alkyl esters 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] In addition to the (meth)acrylate monomers mentioned above, functional group-containing monomers may be used as constituent monomers of the acrylic oligomer as needed. Examples of functional group-containing monomers include monomers having nitrogen atom-containing heterocycles such as N-vinyl-2-pyrrolidone and N-acryloylmorpholine; monomers containing amino groups such as N,N-dimethylaminoethyl (meth)acrylate; monomers containing amide groups such as N,N-diethyl (meth)acrylamide; monomers containing carboxyl groups such as acrylic acid (AA) and methacrylic acid (MAA); and monomers containing hydroxyl groups such as 2-hydroxyethyl (meth)acrylate. These functional group-containing monomers can be used individually or in combination of two or more. When functional group-containing monomers are used, the proportion of functional group-containing monomers in the total monomer components constituting the acrylic oligomer can be, for example, 1% or more by weight, 2% or more by weight, or 3% or more by weight, and can also be, for example, 15% or less by weight, 10% or less by weight, or 7% or less by weight. Acrylic oligomers may also be those that do not use functional group-containing monomers.

[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), and 1-adamantyl acrylate (ADA), as well as 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, and the like.

[0094] Acrylic oligomers can be formed by polymerizing their constituent monomer components. The polymerization method and polymerization mode are not particularly limited, and various conventionally known polymerization methods (e.g., solution polymerization, emulsion polymerization, bulk polymerization, photopolymerization, radiation polymerization, etc.) can be employed in appropriate manner. The types of polymerization initiators that can be used as needed (e.g., azo polymerization initiators) are generally as exemplified for the synthesis of acrylic polymer (A), and the amount of polymerization initiator and the amount of chain transfer agent (e.g., mercaptans) used as needed are appropriately set based on common technical knowledge to achieve the desired molecular weight, so a detailed explanation is omitted.

[0095] When an acrylic oligomer is included in the adhesive layer or adhesive composition, its content can be, for example, 0.01 parts by weight or more per 100 parts by weight of polymer (A), and may be 0.05 parts by weight or more, or 0.1 parts by weight or more, or 0.2 parts by weight or more, from the viewpoint of obtaining a higher effect. Furthermore, from the viewpoint of compatibility with polymer (A), the content of the acrylic oligomer per 100 parts by weight of polymer (A) is usually appropriate to be 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, or 5 parts by weight or less, or 1 part by weight or less. An adhesive layer or adhesive composition that does not contain an acrylic oligomer is also acceptable.

[0096] The adhesive layer or adhesive composition of the adhesive sheet disclosed herein may optionally contain, as needed, various additives common in the field of adhesives, such as tackifying resins (e.g., rosin-based, petroleum-based, terpene-based, phenol-based, ketone-based, etc.), viscosity modifiers (e.g., thickeners), leveling agents, plasticizers, fillers, colorants such as pigments and dyes, stabilizers, preservatives, and anti-aging agents. Such additives can be conventionally used by conventional methods and do not particularly characterize the present invention, so a detailed explanation is omitted. Furthermore, the technology disclosed herein can exhibit good adhesive strength without using the tackifying resin described above. For this reason, in some embodiments, the content of the tackifying resin in the adhesive layer or adhesive composition may be, for example, less than 10 parts by weight, or even less than 5 parts by weight, per 100 parts by weight of polymer (A). The content of the tackifying resin may be less than 1 part by weight (for example, less than 0.5 parts by weight), or less than 0.1 parts by weight (0 parts by weight or more and less than 0.1 parts by weight). The adhesive layer or adhesive composition may not contain the tackifying resin.

[0097] When the adhesive sheet disclosed herein is used for optical applications, the adhesive layer of the adhesive sheet may have predetermined optical properties (e.g., transparency). From the viewpoint of such optical properties, it is preferable that the amount of components other than the polymer (A) and the photoreactive monomer (B) used as needed in the adhesive layer (and by extension, the adhesive composition used to form the adhesive layer) is limited. In the technology disclosed herein, the amount of components other than the polymer (A) and the photoreactive monomer (B) in the adhesive layer is usually about 30% by weight or less, appropriately about 15% by weight or less, and preferably about 12% by weight or less (e.g., about 10% by weight or less). In an adhesive sheet according to one embodiment, the amount of components other than the polymer (A) and the photoreactive monomer (B) in the adhesive layer may be about 5% by weight or less, about 3% by weight or less, or about 1.5% by weight or less (e.g., about 1% by weight or less).

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

[0099] The type of crosslinking agent is not particularly limited, and can be selected from conventionally known crosslinking agents, for example, depending on the composition of the adhesive composition, so that the crosslinking agent exhibits appropriate crosslinking function within the adhesive layer. Examples of crosslinking agents 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 individually or in combination of two or more.

[0100] As isocyanate crosslinking agents, polyfunctional isocyanate compounds with two or more functions can be used. Examples include aromatic isocyanates such as tolylene diisocyanate, xylene diisocyanate, polymethylene polyphenyl diisocyanate, tris(p-isocyanatophenyl)thiophosphate, and diphenylmethane diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; and aliphatic isocyanates such as hexamethylene diisocyanate. Examples of commercially available products include isocyanate adducts such as trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, product name "Coronate L"), trimethylolpropane / hexamethylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, product name "Coronate HL"), isocyanurate of hexamethylene diisocyanate (manufactured by Tosoh Corporation, product name "Coronate HX"), and trimethylolpropane / xylylene diisocyanate adduct (manufactured by Mitsui Chemicals, product name "Takenate D-110N").

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

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

[0103] In some embodiments, peroxides may be used as crosslinking agents. Examples of peroxides include di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxyisobutyrate, and dibenzoyl peroxide. Among these, di(4-t-butylcyclohexyl)peroxydicarbonate, dilauroyl peroxide, and dibenzoyl peroxide are particularly excellent in crosslinking reaction efficiency. When peroxides are used as polymerization initiators, any remaining peroxide that is not used in the polymerization reaction can also be used in the crosslinking reaction. In that case, the amount of remaining peroxide should be quantified, and if the proportion of peroxide is less than a predetermined amount, peroxide should be added as needed to reach the predetermined amount. The quantification of peroxide can be carried out by the method described in Japanese Patent Publication No. 4971517.

[0104] The amount of crosslinking agent used (or the total amount if two or more crosslinking agents are used) is not particularly limited. From the viewpoint of realizing an adhesive that exhibits a good balance of adhesive properties such as adhesion and cohesiveness, the amount of crosslinking agent used is usually appropriate to be approximately 5 parts by weight or less per 100 parts by weight of polymer (A), but may also be 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, or less than 1 part by weight. In embodiments in which a crosslinking agent and a photoreactive monomer (B) are used in combination, from the viewpoint of making it easier to suitably exhibit the effects of such combination use, the amount of crosslinking agent used per 100 parts by weight of polymer (A) may be, for example, 0.80 parts by weight or less, 0.60 parts by weight or less, 0.30 parts by weight or less, or 0.10 parts by weight or less. The lower limit of the amount of crosslinking agent used is not particularly limited, and it may be used in an amount greater than 0 parts by weight per 100 parts by weight of polymer (A). In some embodiments, the amount of crosslinking agent used may be, for example, 0.001 parts by weight or more, 0.01 parts by weight or more, or 0.03 parts by weight or more, per 100 parts by weight of polymer (A).

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

[0106] A crosslinking catalyst may be used to more effectively advance the crosslinking reaction. Examples of crosslinking catalysts include metal-based crosslinking catalysts such as tetra-n-butyl titanate, tetraisopropyl titanate, ferric narcem, butyltin oxide, and dioctyltin dilaurate. Among these, tin-based crosslinking catalysts such as dioctyltin dilaurate are preferred. The amount of crosslinking catalyst used is not particularly limited. The amount of 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, or approximately 1 part by weight or less, approximately 0.1 parts by weight or less, approximately 0.05 parts by weight or less, per 100 parts by weight of polymer (A).

[0107] The adhesive composition used to form the adhesive layer may optionally contain a compound that induces keto-enol tautomerism as a crosslinking retarder. For example, in an adhesive composition containing an isocyanate crosslinking agent or an adhesive composition that may be used with an isocyanate crosslinking agent, a compound that induces keto-enol tautomerism can be preferably used. This can extend the pot life of the adhesive composition. Various β-dicarbonyl compounds can be used as compounds that exhibit keto-enol tautomerism. Specific examples include β-diketones such as acetylacetone and 2,4-hexanedione; acetoacetate esters such as methyl acetoacetate and ethyl acetoacetate; propionyl acetate esters such as ethyl propionylacetate; isobutyryl acetate esters such as ethyl isobutyrylacetate; and malonic acid esters such as methyl malonate and ethyl malonate. Among these, acetylacetone and acetoacetate esters are particularly preferred. The compounds exhibiting keto-enol tautomerism can be used individually or in combination of two or more. The amount of compound that produces keto-enol tautomerism may be, for example, 0.1 parts by weight or more and 20 parts by weight or less per 100 parts by weight of polymer (A), and is usually appropriate to be 0.5 parts by weight or more and 15 parts by weight or less, 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) The adhesive layer of the adhesive sheet disclosed herein may optionally contain a silane coupling agent. The use of a silane coupling agent can improve the peel strength of the adhesive sheet from the adherend (e.g., a glass plate). An adhesive layer containing a silane coupling agent can be suitably formed using an adhesive composition containing a silane coupling agent. In such an adhesive composition, the silane coupling agent is preferably included in the adhesive composition in a free form from the viewpoint of suppressing gelation, etc. Furthermore, in some embodiments, the silane coupling agent is preferably included in the adhesive layer of the adhesive sheet disclosed herein in a free form. A silane coupling agent included in the adhesive layer in such a form can effectively contribute to improving the peel strength. Herein, "free form" means that the silane coupling agent is not chemically bonded to other components contained in the adhesive composition or adhesive layer.

[0109] Examples of silane coupling agents 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; acetoacetyl group-containing trimethoxysilane; (meth)acrylic group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; and isocyanate group-containing silane coupling agents such as 3-isocyanatetopropyltriethoxysilane. In some embodiments, the above-mentioned effects can be more preferably achieved by employing a silane coupling agent having a trialkoxysilyl group. Among the preferred silane coupling agents, 3-glycidoxypropyltrimethoxysilane and acetoacetyl group-containing trimethoxysilane are examples.

[0110] The amount of silane coupling agent used when using a silane coupling agent can be set to obtain the desired effect and is not particularly limited. In some embodiments, the amount of silane coupling agent used may be, for example, 0.001 parts by weight or more per 100 parts by weight of polymer (A), and from the viewpoint of obtaining a higher effect, it may be 0.01 parts by weight or more, 0.05 parts by weight or more, or 0.1 parts by weight or more. Furthermore, from the viewpoint of suppressing gelation of the adhesive composition, the amount of silane coupling agent used per 100 parts by weight of polymer (A) is usually appropriate to be 3 parts by weight or less, but it may also be 1 part by weight or less, or 0.5 parts by weight or less.

[0111] (Photopolymerization initiator) The adhesive layer of the adhesive sheet disclosed herein may contain a photopolymerization initiator as needed for the purpose of improving or imparting photocurability. As the photopolymerization initiator, ketal-based photopolymerization initiators, acetophenone-based photopolymerization initiators, benzoin ether-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, etc., can be used, similar to the photopolymerization initiators exemplified for use in the synthesis of polymer (A). The photopolymerization initiators can be used individually or in appropriate combinations of two or more types.

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

[0113] The content of the photopolymerization initiator in the adhesive layer is not particularly limited and can be set so as to appropriately exhibit the desired effect. In some embodiments, the content of the photopolymerization initiator can be, for example, approximately 0.005 parts by weight or more per 100 parts by weight of polymer (A) contained in the adhesive layer, usually 0.01 parts by weight or more is appropriate, preferably 0.05 parts by weight or more, may be 0.10 parts by weight or more, may be 0.15 parts by weight or more, or may be 0.20 parts by weight or more. Increasing the content of the photopolymerization initiator tends to improve the photocurability of the adhesive layer. In addition, the content of the photopolymerization initiator per 100 parts by weight of polymer (A) is usually appropriate to be 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, or may be 1 part by weight or less. Not having too much photopolymerization initiator content can be advantageous from the viewpoint of improving the storage stability of the adhesive sheet (e.g., stability against photodegradation).

[0114] An adhesive layer containing a photopolymerization initiator can typically be formed using an adhesive composition containing the photopolymerization initiator (e.g., a solvent-based adhesive composition). The adhesive composition containing the photopolymerization initiator can be prepared, for example, by mixing the photopolymerization initiator with other components used in the composition. Furthermore, when preparing an adhesive composition using a polymer (A) synthesized (photopolymerized) in the presence of a photopolymerization initiator (e.g., an acrylic polymer (A)), the residue (unreacted material) of the photopolymerization initiator used in the synthesis of polymer (A) may be used as part or all of the photopolymerization initiator contained in the adhesive layer. The same applies when using an acrylic oligomer synthesized in the presence of a photopolymerization initiator, as needed. From the viewpoint of ease of manufacturing control, the adhesive layers disclosed herein can preferably be formed using an adhesive composition prepared by adding the above-described amount of photopolymerization initiator to other components.

[0115] Furthermore, the adhesive layer in the technology disclosed herein may optionally contain known additives that can be used in adhesives, such as leveling agents, plasticizers, softeners, colorants (dyes, pigments, etc.), fillers, antistatic agents, anti-aging agents, ultraviolet absorbers, antioxidants, light stabilizers, and preservatives, to the extent that the effects of the present invention are not significantly hindered. However, for adhesive sheets intended for applications where the inclusion of siloxanes is undesirable (e.g., for the manufacture of electronic equipment), it is desirable to avoid the use of silicone-based additives (e.g., silicone-based leveling agents and defoamers).

[0116] <Formation of the adhesive layer> The adhesive layer constituting the adhesive sheet disclosed herein may be a cured layer of an adhesive composition containing the corresponding components. That is, the adhesive layer may be formed by applying (e.g., coating) the adhesive composition to 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 crosslinking agent described above), and cooling. When two or more curing treatments are performed, they may be carried out simultaneously or in stages.

[0117] In some embodiments, the adhesive composition contains at least one of the polymers (A) described above. In one preferred embodiment, the adhesive composition contains an acrylic polymer (A) as the polymer (A). The adhesive composition may contain the polymer (A) in the form of its precursor. The adhesive composition preferably contains one of the polymers (A) described above and one of the photoreactive monomers (B) described above. The photoreactive monomer (B) preferably contains a compound B1 having a ring structure and two or more ethylenically unsaturated groups in its molecule. The 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 and may be various conventionally known forms, such as a water-dispersible adhesive composition in which the adhesive (adhesive component) is dispersed in water, a solvent-type adhesive composition in which the adhesive is contained in an organic solvent, or a hot-melt type adhesive composition that is applied in a heated molten state and forms an adhesive when cooled to around room temperature. From the viewpoint of ease of preparation of the adhesive composition and ease of formation of the adhesive layer, a solvent-type adhesive composition may be preferably used in some embodiments. The solvent-type adhesive composition may preferably be prepared using a polymer (A) which is a polymer obtained by solution polymerization of monomer components.

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

[0120] The thickness of the adhesive layer is not particularly limited and may be, for example, about 3 μm to 500 μm. From the viewpoint of impact resistance, in some embodiments, the thickness of the adhesive layer is suitable to be 5 μm or more, preferably 10 μm or more, and more preferably 15 μm or more. Also, in some embodiments, the thickness of the adhesive layer may be, for example, 200 μm or less, preferably 120 μm or less from the viewpoint of suppressing deformation of the adhesive layer, 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 embodiments comprising an adhesive layer with a thickness of, for example, 70 μm or less, a bond with high deformation resistance and high impact resistance can be formed.

[0121] <Support> Adhesive sheets according to some embodiments may take the form of an adhesive sheet with a support, which includes a support bonded to an adhesive layer. The material of the support is not particularly limited and can be appropriately selected depending on the purpose and manner of use of the adhesive sheet. Non-limiting examples of usable supports include: resin films such as polyolefin films mainly composed of polyolefins such as polypropylene and ethylene-propylene copolymer, polyester films mainly composed of polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polyvinyl chloride films mainly composed of polyvinyl chloride; foam sheets made of foams such as polyurethane foam, polyethylene foam, and polychloroprene foam; woven and nonwoven fabrics made by single or blended fibrous materials (which may be natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, and semi-synthetic fibers such as acetate); papers such as Japanese paper, fine paper, kraft paper, and crepe paper; and metal foils such as aluminum foil and copper foil. Supports may also have a composite structure of these materials. Examples of such composite support structures include, for example, a support structure in which a metal layer (e.g., metal foil, continuous or discontinuous metal sputtered layer, metal vapor deposition layer, metal plating layer, etc.) or a metal oxide layer is laminated with the resin film, and a resin sheet reinforced with inorganic fibers such as glass cloth. The support may also correspond to an optical component (e.g., an optical film) as described later, or it may be a transparent component formed from a transparent material (e.g., a transparent resin material or glass, etc.).

[0122] Various films (hereinafter also referred to as support films) can be preferably used as the support for the adhesive sheet disclosed herein. The support film may be a porous film such as a foam film or a nonwoven fabric sheet, a nonporous film, or a film with a structure in which a porous layer and a nonporous layer are laminated. In some embodiments, the support film may preferably include a resin film that is independently shape-retaining (self-supporting or independent) as a base film. Here, "resin film" means a resin film with a nonporous structure, which is typically substantially free of air bubbles (voidless). Therefore, the resin film is a concept distinct from foam films and nonwoven fabrics. The resin film may have a single-layer structure or a multilayer structure of two or more layers (for example, a three-layer structure).

[0123] As resin materials constituting the resin film, for example, polycycloolefins derived from monomers having an aliphatic ring structure such as polyester, polyolefins, norbornene structures, polyamides (PA) such as nylon 6, nylon 66, and partially aromatic polyamides, polyimides (PI), polyamide-imides (PAI), polyetheretherketones (PEEK), polyethersulfones (PES), polyphenylene sulfide (PPS), polycarbonate (PC), polyurethane (PU), ethylene-vinyl acetate copolymers (EVA), fluororesins such as polystyrene, polyvinyl chloride, polyvinylidene chloride, and polytetrafluoroethylene (PTFE), acrylic resins such as polymethyl methacrylate, cellulosic polymers such as diacetylcellulose and triacetylcellulose, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, and epoxy polymers can be used. The above resin film may be formed using a resin material containing one of these resins alone, or it may be formed using a resin material blended with two or more of these resins. The above resin film may be unstretched or stretched (for example, uniaxially stretched or biaxially stretched).

[0124] Suitable examples of resin materials constituting resin films include polyester resins, PPS resins, and polyolefin resins. Here, a polyester resin refers to a resin containing polyester in a proportion of more than 50% by weight. Similarly, a PPS resin refers to a resin containing PPS in a proportion of more than 50% by weight, and a polyolefin resin refers to a resin containing polyolefin in a proportion of more than 50% by weight.

[0125] Typically, polyester resins are used that primarily contain polyester obtained by polycondensation of dicarboxylic acid and diol. Specific examples of polyester resins include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polybutylene naphthalate.

[0126] Polyolefin resins can be made using one type of polyolefin alone or in combination of two or more types of polyolefins. These polyolefins may include, for example, α-olefin homopolymers, copolymers of two or more α-olefins, or copolymers of one or more α-olefins with other vinyl monomers. Specific examples include polyethylene (PE), polypropylene (PP), poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene rubber (EPR), ethylene-propylene-butene copolymers, ethylene-butene copolymers, ethylene-vinyl alcohol copolymers, and ethylene-ethyl acrylate copolymers. Both low-density (LD) and high-density (HD) polyolefins are usable. Examples of polyolefin resin films include unoriented polypropylene (CPP) film, biaxially oriented polypropylene (OPP) film, low-density polyethylene (LDPE) film, linear low-density polyethylene (LLDPE) film, medium-density polyethylene (MDPE) film, high-density polyethylene (HDPE) film, polyethylene (PE) film made by blending two or more types of polyethylene (PE), and PP / PE blend film made by blending polypropylene (PP) and polyethylene (PE).

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

[0128] The resin film may contain known additives such as light stabilizers, antioxidants, antistatic agents, colorants (dyes, pigments, etc.), fillers, slip agents, and antiblocking agents, as needed. The amount of additives is not particularly limited and can be set appropriately depending on the application of the adhesive sheet.

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

[0130] The above-mentioned support may be a support film substantially composed of such a resin film. Alternatively, the support may be a support film that includes an auxiliary layer in addition to the resin film. The auxiliary layer may be located on the adhesive layer side of the resin film, on the opposite side from the adhesive layer, or on both sides of the resin film. Examples of the auxiliary layer include optical property adjustment layers (e.g., coloring layers, anti-reflective layers), decorative layers that impart a desired appearance to the support or adhesive sheet (e.g., printing layers, laminating layers, continuous or discontinuous metal layers, continuous or discontinuous metal oxide layers, etc.), conductive layers, antistatic layers, primer layers, release layers, and the like.

[0131] The thickness of the support is not particularly limited and can be selected according to the purpose and manner of use of the adhesive sheet. The thickness of the support may be, for example, 1000 μm or less, 500 μm or less, 100 μm or less, 70 μm or less, 50 μm or less, 25 μm or less, 10 μm or less, or 5 μm or less. As the thickness of the support decreases, the flexibility of the adhesive sheet and its ability to conform to the surface shape of the adherend tend to improve. Also, from the viewpoint of handling and processability, the thickness of the support may be, for example, 2 μm or more, or greater than 5 μm or greater than 10 μm. In some embodiments, the thickness of the support may be, for example, 20 μm or more, 35 μm or more, or 55 μm or more.

[0132] The side of the support that is joined to the adhesive layer may be subjected to conventionally known surface treatments as needed, such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, application of a primer, or antistatic treatment. Such surface treatments may be intended to improve the adhesion between the support and the adhesive layer, in other words, the anchoring ability of the adhesive layer to the support. The composition of the primer is not particularly limited and can be appropriately selected from known primers. The thickness of the undercoat layer is not particularly limited, but is usually appropriate at about 0.01 μm to 1 μm, and preferably at about 0.1 μm to 1 μm.

[0133] In a single-sided adhesive sheet with a support, the side of the support opposite to the side bonded to the adhesive layer (hereinafter also referred to as the back surface) may be subjected to conventionally known surface treatments such as release treatment, adhesion or tackiness improvement treatment, or antistatic treatment, as needed. For example, by surface treating the back surface of the support with a release agent, the unwinding force of an adhesive sheet wound in a roll can be reduced. Examples of release agents that can be used include silicone-based release agents, long-chain alkyl-based release agents, olefin-based release agents, fluorine-based release agents, fatty acid amide-based release agents, molybdenum sulfide, silica powder, etc.

[0134] <Laminate Manufacturing Method> The adhesive sheets disclosed herein may be preferably used in a manner in which they are attached to an adherend by a method that includes photocuring the adhesive layer after bonding the adhesive sheet to the adherend. By bonding the adhesive sheet to an adherend, an adherend in which the adhesive sheets are laminated is formed. By photocuring the adhesive layer of this adhesive sheet, a laminate is obtained in which the adhesive sheet with the cured adhesive layer and the adherend are obtained. Therefore, this specification provides a method for manufacturing a laminate comprising bonding one of the adhesive sheets disclosed herein to an adherend, and photocuring the adhesive layer of the adhesive sheet by irradiating it with ultraviolet light, in this order.

[0135] <Application> The adhesive sheets disclosed herein can be used for applications such as fixing, joining, molding, decorating, protecting, and supporting components of various products. The material constituting at least the surface of the component may be, for example, glass such as alkali glass or alkali-free glass; metal materials such as stainless steel (SUS) or aluminum; resin materials such as acrylic resin, ABS resin, polycarbonate resin, or polystyrene resin. The component may be, for example, a component of various portable devices, automobiles, home appliances, etc. Furthermore, the surface to which the adhesive sheet is attached may be a painted surface with paints such as acrylic, polyester, alkyd, melamine, urethane, acid epoxy crosslinked, or composites thereof (e.g., acrylic melamine, alkyd melamine), or a plated surface such as galvanized steel sheet. In addition, the component may be any of the support films exemplified as materials that can be used as a support (e.g., a resin film, or a support film having a continuous or discontinuous inorganic layer (which may be a metal layer, a metal oxide layer, etc.) on a resin film). The adhesive sheet disclosed herein may be, for example, a component of an adhesive sheet-attached member in which the member is bonded to at least one surface of the adhesive layer constituting the adhesive layer.

[0136] One example of a preferred application is an optical application. More specifically, the adhesive sheet disclosed herein can be preferably used as an optical adhesive sheet for applications such as bonding optical components together (for bonding optical components) or for manufacturing products using the optical components (optical products).

[0137] The above-mentioned optical components refer to components that have optical properties (for example, polarization, refractiveness, scattering, reflectivity, transmission, absorption, diffraction, optical rotation, visibility, etc.). The above-mentioned optical components are not particularly limited as long as they have optical properties, but examples include components that make up devices (optical devices) such as display devices (image display devices) and input devices, or components used in such devices. Examples include polarizers, waveplates, phase difference plates, optical compensation films, brightness enhancement films, light guide plates, reflective films, anti-reflective films, hard coat (HC) films, shock-absorbing films, anti-fouling films, photochromic films, dimming films, transparent conductive films (ITO films), decorative films, surface protection plates, prisms, lenses, color filters, transparent substrates, and even components in which these are laminated (these are sometimes collectively referred to as "functional films"). Furthermore, the terms "plate" and "film" above include forms such as plate-like, film-like, and sheet-like shapes, respectively. For example, "polarizing film" includes "polarizing plate," "polarizing sheet," etc.

[0138] Examples of the above-mentioned display devices include liquid crystal displays, organic electroluminescent (EL) displays, PDPs (plasma display panels), and electronic paper. Examples of the above-mentioned input devices include touch panels.

[0139] The optical components mentioned above are not particularly limited, but examples include components made of glass, acrylic resin, polycarbonate, polyethylene terephthalate, metal thin films, etc. (for example, sheet-like, film-like, or plate-like components). In this specification, "optical components" also include components that serve a decorative or protective role while maintaining the visibility of display devices and input devices (such as design films, decorative films, and surface protection films).

[0140] The manner in which optical members are bonded using the adhesive sheet disclosed herein is not particularly limited, but may include, for example, (1) bonding optical members to each other via the adhesive sheet disclosed herein, (2) bonding an optical member to a member other than an optical member via the adhesive sheet disclosed herein, or (3) a form in which the adhesive sheet disclosed herein includes an optical member and the adhesive sheet is bonded to an optical member or a member other than an optical member. In the embodiment of (3) above, the adhesive sheet that includes an optical member may be, for example, an adhesive sheet whose support is an optical member (e.g., an optical film). Such an adhesive sheet that includes an optical member as a support can also be understood as an adhesive-type optical member (e.g., an adhesive-type optical film). Furthermore, if the adhesive sheet disclosed herein is an adhesive sheet having a support, and the functional film is used as the support, the adhesive sheet disclosed herein can also be understood as an "adhesive-type functional film" having the adhesive layer disclosed herein on at least one side of the functional film.

[0141] The matters disclosed in this specification include the following: (1) An adhesive sheet containing an adhesive layer, The above adhesive layer contains a polymer (A) and a photoreactive monomer (B), The above photoreactive monomer (B) comprises compound B1 having two or more ethylenically unsaturated groups, Compound B1 is an adhesive sheet having a molecular weight (functional group equivalent) of 100 g / mol or more per ethylenically unsaturated group. (2) Compound B1 is the adhesive sheet described in (1) above, wherein the compound B1 contains a ring structure within the molecule. (3) The adhesive sheet according to (2) above, wherein compound B1 contains in its molecule at least one structure selected from the group consisting of a bisphenol A structure, a bisphenol F structure, and a bisphenol E structure. (4) The adhesive sheet according to (2) or (3) above, wherein compound B1 includes an aliphatic ring structure as the ring structure. (5) The adhesive sheet according to any one of (1) to (4) above, wherein compound B1 contains in its molecule at least one structure selected from the group consisting of a hydroxyl group and an amino group. (6) The adhesive sheet according to any one of (1) to (5) above, wherein the content of compound B1 in the adhesive layer is 0.5 parts by weight or more and 60 parts by weight or less per 100 parts by weight of polymer (A). (7) The adhesive sheet according to any one of (2) to (5) above, wherein the adhesive layer comprises the above-mentioned compound B1 and compound B2 having two or more functional groups and no ring structure in the molecule as the above-mentioned photoreactive monomer (B). (8) The adhesive sheet as described in (7) above, wherein the functional group equivalent of compound B2 is less than the functional group equivalent of compound B1. (9) The adhesive sheet according to (7) or (8) above, wherein the functional group equivalent of compound B2 is 400 g / mol or less. (10) The adhesive sheet according to any one of (7) to (9) above, wherein the content of compound B2 in the adhesive layer is 25 parts by weight or less per 100 parts by weight of polymer (A). (11) The adhesive sheet according to any one of (1) to (10) above, wherein the content of the photoreactive monomer (B) in the adhesive layer is 1 part by weight or more and 80 parts by weight or less per 100 parts by weight of the polymer (A). (12) The adhesive sheet according to any of (1) to (11) above, wherein the polymer (A) is an acrylic polymer. (13) The adhesive sheet according to (12) above, wherein the monomer component constituting the acrylic polymer includes a monomer having a nitrogen atom-containing ring. (14) The adhesive sheet according to any of (1) to (13) above, wherein the glass transition temperature of the polymer (A) is -45°C or higher and less than 0°C. (15) The adhesive sheet according to any of (1) to (14) above, wherein the adhesive layer is crosslinked with a crosslinking agent. (16) The adhesive sheet according to any one of (1) to (15) above, wherein the adhesive layer contains a photopolymerization initiator. (17) The adhesive sheet according to any of (1) to (14) above, wherein the adhesive layer contains a silane coupling agent. (18) An adhesive sheet as described in any of (1) to (17) above, wherein the tensile modulus measured by the above tensile test is 3.0 MPa or higher. (19) The impact resistance measured by the above shear impact test is 2.0 J / (10 mm) 2 The adhesive sheet described in any of (1) to (18) above. (20) An adhesive sheet according to any 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) comprising polymer (A) and photoreactive monomer (B), The above photoreactive monomer (B) comprises compound B1 having two or more ethylenically unsaturated groups, Compound B1 is an adhesive composition in which the molecular weight (functional group equivalent) per ethylenically unsaturated group is 100 g / mol or more. (22) The adhesive sheet described in (21) above, wherein compound B1 contains a ring structure within the molecule. (23) The adhesive composition according to (22) above, wherein compound B1 contains in its molecule at least one structure selected from the group consisting of a bisphenol A structure, a bisphenol F structure, and a bisphenol E structure. (24) The adhesive composition according to (2) or (23) above, wherein compound B1 includes an aliphatic ring structure as the ring structure. (25) The adhesive composition according to any one of (21) to (24) above, wherein compound B1 contains in its molecule at least one structure selected from the group consisting of a hydroxyl group and an amino group. (26) The adhesive composition according to any one of (21) to (25), wherein the content of compound B1 in the adhesive layer is 0.5 parts by weight or more and 60 parts by weight or less per 100 parts by weight of polymer (A). (27) The adhesive layer comprises, as the photoreactive monomer (B), compound B1 and compound B2 having two or more functional groups and no ring structure in the molecule, according to any one of (22) to (25). (28) The adhesive composition according to (27), wherein the functional group equivalent of compound B2 is less than the functional group equivalent of compound B1. (29) The adhesive composition according to (27) or (28) above, wherein the functional group equivalent of compound B2 is 400 g / mol or less. (30) The adhesive composition according to any one of (27) to (29), wherein the content of compound B2 in the adhesive layer is 25 parts by weight or less per 100 parts by weight of polymer (A). (31) The adhesive composition according to any one of (21) to (30), wherein the content of the photoreactive monomer (B) in the adhesive layer is 1 part by weight or more and 80 parts by weight or less per 100 parts by weight of the polymer (A). (32) The adhesive composition according to any one of (21) to (31) above, wherein the polymer (A) is an acrylic polymer. (33) The adhesive composition according to (32) above, wherein the monomer component constituting the acrylic polymer includes a monomer having a nitrogen atom-containing ring. (34) The adhesive composition according to any one of (21) to (33) above, wherein the glass transition temperature of the polymer (A) is -45°C or higher and less than 0°C. (35) The adhesive composition according to any one of (21) to (34) above, comprising a crosslinking agent. (36) The adhesive composition according to any one of (21) to (35) above, comprising a photopolymerization initiator. (37) The adhesive composition according to any one of (21) to (36) above, comprising a silane coupling agent. (38) An adhesive composition according to any one of (21) to (37) above, used to form an adhesive layer of an adhesive sheet according to any one of (1) to (20). (39) An adhesive sheet comprising an adhesive layer composed of any of the adhesive compositions described in (21) to (37) above.

[0143] (40) An adhesive sheet comprising an adhesive layer, The tensile modulus measured by the above tensile test is 3.0 MPa or higher, and the impact resistance measured by the above shear impact test is 2.0 J / (10 mm). 2 That's all for the adhesive sheet. (41) The adhesive sheet described in (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 of (40) to (41), wherein the adhesive layer is the adhesive layer according to any of (1) to (17) above. (43) The adhesive sheet according to any one of (40) to (42), wherein the adhesive layer is an adhesive layer formed from the adhesive composition described in any one of (21) to (37) above.

[0144] (44) The adhesive composition according to any one of (21) to (37) above, wherein the adhesive layer formed from the adhesive composition and having a thickness selected from the range of 5 μm to 200 μm (preferably in the range of 15 μm to 25 μm) (for example, an adhesive layer with a thickness of 20 μm) has a tensile modulus of elasticity of 3.0 MPa or more as measured by the tensile test. (45) The above adhesive composition has an impact resistance of 2.0 J / (10 mm) measured by the above shear impact test for an adhesive layer of the above thickness formed from the adhesive composition. 2 The adhesive composition described in (44) above. (46) The adhesive composition according to (44) or (45), wherein the peel strength measured by the peel test for an adhesive layer of the above thickness formed from the adhesive composition is 1.0 N / 10 mm or more. (47) A film member with an adhesive sheet, comprising an adhesive sheet as described in any of (1) to (20) and (40) to (43) above, and a film member bonded to the adhesive layer. (48) Adhering an adhesive sheet described in any of (1) to (20) and (40) to (43) above to the object to be attached, The adhesive sheet is irradiated with ultraviolet light to photocur the adhesive layer, A method for manufacturing a laminate, comprising the elements in this order.

[0145] The following describes several embodiments of the present invention, but the present invention is not intended to be limited to those shown in these embodiments. In the following description, "parts" and "%" refer to weight unless otherwise specified.

[0146] <Synthesis of polymer (A)> (Polymer P1) In a reaction vessel equipped with a condenser, nitrogen inlet tube, thermometer, and stirrer, 60 parts n-butyl acrylate (BA), 6 parts cyclohexyl acrylate (CHA), 18 parts N-vinyl-2-pyrrolidone (NVP), 1 part isostearyl acrylate (iSTA), and 15 parts 4-hydroxybutyl acrylate (4HBA) were charged as monomer components, 0.085 parts α-thioglycerol was added as a chain transfer agent, and 122 parts ethyl acetate was added as a polymerization solvent. 0.2 parts 2,2'-azobisisobutyronitrile (AIBN) was added as a thermal polymerization initiator, and 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 above monomer component composition, is -33°C.

[0147] (Polymer P2) In a reaction vessel equipped with a condenser, nitrogen inlet tube, thermometer, and stirrer, 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 parts of α-thioglycerol as a chain transfer agent, and 122 parts of ethyl acetate as a polymerization solvent. 0.2 parts of AIBN were added as a thermal polymerization initiator, and 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 above monomer component composition, is -39°C.

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

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

[0150] (Example 4) The solvent-type adhesive composition for this example was prepared in the same manner as the solvent-type adhesive composition for Example 3, except that an 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) The solvent-type adhesive composition according to this example was prepared in the same manner as the preparation of the solvent-type adhesive composition according to Example 10, except that the solution of polymer P2 was used instead of the solution of polymer P1.

[0152] <Making adhesive sheets> A 38 μm thick release film R1 (Mitsubishi Plastics, MRF#38), with one side of the polyester film being a release surface, was coated with the solvent-type adhesive composition prepared in each example above. The mixture was dried at 130°C for 3 minutes to form a 20 μm thick photocurable adhesive layer (supportless double-sided adhesive sheet). The release surface of a 38 μm thick release film R2 (Mitsubishi Plastics, MRE#38), with one side of the polyester film being a release surface, was bonded to the surface of this adhesive layer for protection. In this way, a laminated sheet was obtained in which release film R1, supportless double-sided adhesive sheet, and release film R2 were laminated in this order.

[0153] <Measurement and Evaluation> The following measurements and evaluations were performed on the obtained adhesive sheets. (1) Measurement of tensile modulus For each example, the laminated sheet (a laminated sheet consisting of a supportless adhesive layer sandwiched between two transparent release films) was subjected to an illuminance of 300 mW / cm using a high-pressure mercury lamp. 2 , cumulative light intensity 3000 mJ / cm 2 The laminated sheet was irradiated with ultraviolet light under the specified conditions and aged at 50°C for 48 hours. After this, the laminated sheet was cut to a size of 10 mm in width and 150 mm in length. Under conditions of 23°C and 50% RH, the release films R1 and R2 were peeled off to expose the adhesive layer. A tensile test was then performed on the specimen using a tensile testing machine (Minebea Co., Ltd., universal tensile and compression testing machine, device name "Tensile and Compression Testing Machine, TCM-1kNB") with a chuck distance of 120 mm and a tensile speed of 50 mm / min to obtain the SS curve. The tensile modulus [MPa] was calculated from the initial slope (the slope in the elastic deformation region of the SS curve, specifically the slope in the range where the displacement is approximately less than 5%). The measurement was performed three times (i.e., n=3), and the arithmetic mean values ​​are shown in Tables 1 and 2.

[0154] (2) Measurement of impact resistance Shear impact tests were performed using a pendulum-type adhesive shear impact tester based on JIS K6855. For the measurement samples, the laminated sheets for each example were cut into 10 mm squares, the release film R1 was peeled off to expose the first surface of the adhesive layer, and this first surface was bonded to the center of a 25 mm square, 1.7 mm thick chemically strengthened glass plate (manufactured by Corning). Then, the release film R2 was peeled off and the second surface of the adhesive layer was bonded to the center of a 40 mm square stainless steel plate (SUS304BA plate) and pressed with a load of 5 N for 10 seconds. Subsequently, autoclaving (50°C, 0.5 MPa, 15 minutes) was performed, and an illuminance of 300 mW / cm was applied from the glass plate side using a high-pressure mercury lamp. 2 , cumulative light intensity 3000 mJ / cm 2 The sample used was one that had been irradiated with ultraviolet light under the specified conditions, followed by aging at 50°C for 48 hours. The above measurement sample was fixed with the stainless steel plate facing downwards, and under conditions of 23°C and 50% RH, a hammer was struck against the outer surface of the glass plate with a hammer energy of 2.75 J and a hammer velocity (impact velocity) of 3.5 m / sec. The absorbed energy [J] was measured to determine the impact resistance [J / (10mm)]. 2 We calculated [the value]. The measurement was performed three times, and the arithmetic mean of these measurements is shown in Tables 1 and 2.

[0155] (3) Peel strength A test specimen was prepared by cutting the laminated sheet for each example to a size of 10 mm in width and 150 mm in length. The first surface of the adhesive layer of the test specimen was pressed onto a glass plate (alkali glass plate manufactured by Matsunami Glass Industry Co., Ltd., made by the float method, 1.35 mm thick, blue plate with polished edges) by passing a 2 kg rubber roller back and forth once. After autoclaving (50°C, 0.5 MPa, 15 minutes), an illuminance of 300 mW / cm² was applied from the glass plate side using a high-pressure mercury lamp. 2 , cumulative light intensity 3000 mJ / cm 2The specimen was irradiated with ultraviolet light under the specified conditions. After aging at 50°C for 48 hours, the peel strength was measured when peeling the specimen from the glass plate using a tensile testing machine (Minebea Co., Ltd., universal tensile and compression testing machine, device name "Tensile and Compression Testing Machine, TCM-1kNB") in an environment of 23°C and 50% RH, under the conditions of a peel angle of 180 degrees and a tensile speed of 60 mm / min. Three measurements were taken, and the arithmetic mean values ​​are shown in Tables 1 and 2.

[0156] Furthermore, when the haze values ​​of the adhesive layers of the adhesive sheets in Examples 1, 6, 8, and 11 were measured using the method described above, they were all 0.5% or less. The adhesive layers of the adhesive sheets in Examples 6 and 8 showed particularly good transparency.

[0157] [Table 1]

[0158] [Table 2]

[0159] The photoreactive monomers used in Examples 1-13 are as follows. In Tables 1 and 2, each photoreactive monomer is shown by its abbreviation. DPHA: Dipentaerythritol hexaacrylate (Shin-Nakamura Chemical Co., Ltd., product name "A-DPH", functional group equivalent 96) A-DCP: Tricyclodecanedimethanol diacrylate (Shin-Nakamura Chemical Co., Ltd., trade name "A-DCP", functional group equivalent 152) #540: Bisphenol A diglycidyl ether acrylic acid adduct (Osaka Organic Chemical Industry Co., Ltd., product name "Viscote #540", functional group equivalent weight 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 molar adduct diacrylate (Osaka Organic Chemical Industry Co., Ltd., product name "Viscote #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 Industry Co., Ltd., product name "APG-400", functional group equivalent 268)

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

[0161] Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. [Explanation of symbols]

[0162] 1,2 Adhesive sheets 10 Adhesive layer 10A One side (adhesive side) 10B The other side 20 Support 20A front page 20B Second side (back) 30, 31, 32 Release Liner 50 Adhesive sheets with release liner 70 Film component 100 Adhesive sheet-attached components

Claims

1. An adhesive sheet containing an adhesive layer, The adhesive layer contains an acrylic polymer (A) and a photoreactive monomer (B), The glass transition temperature of the acrylic polymer (A) is -80°C or higher and less than -20°C. The photoreactive monomer (B) comprises compound B1 having a ring structure and two or more ethylenically unsaturated groups in its molecule, and compound B2 having five or more ethylenically unsaturated groups without a ring structure in its molecule, wherein the functional group equivalent of compound B1 is FE １ The functional group equivalent FE of compound B2 relative to the above ２ Ratio (FE ２ / FE １ ) is 0.7 or less, The ratio of the amount of compound B2 to the amount of compound B1 in the adhesive layer is 0.2 or more and 8 / 8 or less. The elastic modulus measured by the tensile test described below is 3.0 MPa or higher, and the impact resistance measured by the shear impact test described below is 2.0 J / (10 mm). ２ That's all for the adhesive sheet. [Tensile Test] The adhesive layer is exposed to an illuminance of 300 mW / cm². ２ , cumulative light intensity 3000 mJ / cm ２ The adhesive layer is irradiated with ultraviolet light under the specified conditions and aged at 50°C for 48 hours. After this, the adhesive layer is cut to a size of 10 mm in width and 150 mm in length to prepare a test specimen. In an environment of 23°C and 50% RH, a tensile test is performed on the test specimen using a tensile testing machine with a chuck distance of 120 mm and a tensile speed of 50 mm / min to obtain a stress-displacement curve, and the modulus of elasticity [MPa] is calculated from its initial slope. [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 10 mm square adhesive layer to the center of a 25 mm square, 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) and crimped with a 5 N weight for 10 seconds. Then, autoclave treatment (50 °C, 0.5 MPa, 15 minutes) is performed, 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 irradiation, the sample is aged at 50 °C for 48 hours and then used. The measurement sample is fixed with the stainless steel plate facing downwards, and the absorbed energy [J] is measured when a hammer is struck against the outer surface of the glass plate under the conditions of hammer energy 2.75 J and hammer speed 3.5 m / s in an environment of 23°C and 50% RH, thereby determining the impact resistance [J / (10 mm)]. ２ To find out ].

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] The adhesive sheet was cut to a size of 10 mm in width and 150 mm in length to prepare a test piece. This test piece was pressed onto a glass plate by rolling a 2 kg rubber roller back and forth once, and then autoclaved (50°C, 0.5 MPa, 15 minutes). After that, an illuminance of 300 mW / cm² was applied from the glass plate side. ２ , cumulative light intensity 3000 mJ / cm ２ The specimen is irradiated with ultraviolet light under the specified conditions. After aging at 50°C for 48 hours, the peel strength is measured when the specimen is peeled from the glass plate using a tensile testing machine 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 compound B1 has a molecular weight of 100 g / mol or more per ethylenically unsaturated group.

4. An adhesive sheet containing an adhesive layer, The adhesive layer contains an acrylic polymer (A) and a photoreactive monomer (B), The glass transition temperature of the acrylic polymer (A) is -80°C or higher and less than -20°C. The photoreactive monomer (B) comprises compound B1 having a ring structure and two or more ethylenically unsaturated groups in its molecule, and compound B2 having five or more ethylenically unsaturated groups without a ring structure in its molecule, wherein the functional group equivalent of compound B1 is FE １ The functional group equivalent FE of compound B2 relative to the above ２ Ratio (FE ２ / FE １ ) is 0.7 or less, The compound B1 has a molecular weight of 100 g / mol or more per ethylenically unsaturated group. An adhesive sheet in which the ratio of the amount of compound B2 to the amount of compound B1 in the adhesive layer is 0.2 or more and 8 / 8 or less.

5. The adhesive sheet according to claim 4, wherein the modulus of elasticity measured by the tensile test described below is 3.0 MPa or more. [Tensile Test] The adhesive layer is exposed to an illuminance of 300 mW / cm². ２ , cumulative light intensity 3000 mJ / cm ２ The adhesive layer is irradiated with ultraviolet light under these conditions and aged at 50°C for 48 hours. After this, the adhesive layer is cut to a size of 10 mm in width and 150 mm in length to prepare a test specimen. In an environment of 23°C and 50% RH, a tensile test is performed on the test specimen using a tensile testing machine with a chuck distance of 120 mm and a tensile speed of 50 mm / min to obtain a stress-displacement curve, and the modulus of elasticity is calculated from its initial slope.

6. The impact resistance measured by the shear impact test described below is 2.0 J / (10 mm). ２ The adhesive sheet according to claim 4 or 5. [Shear Impact Test] A shear impact test is performed using a pendulum-type adhesive shear impact tester based on JIS K6855. For the measurement sample, the first surface of a 10 mm square adhesive layer is bonded to the center of a 25 mm square, 1.7 mm thick chemically strengthened glass plate. Then, the second surface of the adhesive layer is bonded to the center of a 40 mm square stainless steel plate (SUS304BA plate) and pressed with a load of 5 N for 10 seconds. Subsequently, it is autoclaved (50°C, 0.5 MPa, 15 minutes), and an illuminance of 300 mW / cm² is applied from the glass plate side. ２ , cumulative light intensity 3000 mJ / cm ２ The product used will have been irradiated with ultraviolet light under these conditions, followed by aging at 50°C for 48 hours. The measurement sample is fixed with the stainless steel plate facing downwards, and the absorbed energy [J] is measured when a hammer is struck against the outer surface of the glass plate under the conditions of hammer energy 2.75 J and hammer speed 3.5 m / s in an environment of 23°C and 50% RH, thereby determining the impact resistance [J / (10 mm)]. ２ To find out ].

7. A film member with an adhesive sheet, comprising an adhesive sheet according to any one of claims 1 to 6 and a film member bonded to the adhesive layer.

8. The adhesive sheet described in any one of claims 1 to 6 is attached to the object to be adhered, The adhesive sheet is irradiated with ultraviolet light to photocur the adhesive layer, A method for manufacturing a laminate, comprising the elements in this order.

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