JPWO2018101252A1 - Photocurable composition, pressure-sensitive adhesive sheet, pressure-sensitive adhesive sheet laminate, cured product, laminate for constituting image display device, and image display device - Google Patents

Abstract

When heated to a temperature at which hot-melting is possible, it can be filled to every corner following the irregularities on the bonding surface, and after photo-curing, new photo-curing that can adhere the adherends more firmly To provide a sex composition. A photocurable composition comprising a (meth) acrylic copolymer (A) having a macromonomer as a copolymerizable component, a crosslinking agent (B), and a crosslinking initiator (C), in small-angle X-ray scattering measurement A photocurable composition is proposed in which the half width X1 (nm-1) of the one-dimensional scattering profile is 0.05 <X1 <0.30.

Description

  The present invention relates to a photocurable composition using a (meth) acrylic copolymer containing a macromonomer as a structural unit, and an adhesive sheet, an adhesive sheet laminate, a cured product, and an image display device configuration using the same. The present invention relates to a laminate for an image and an image display device.

  A macromonomer is a high molecular weight monomer having a functional group capable of bonding. The macromonomer can easily synthesize a graft copolymer by addition or copolymerization with another monomer. And when synthesizing a graft copolymer using a macromonomer, since resins having different physical properties can be separately incorporated into the branch component and the trunk component, respectively, and easily and with high purity, Various pressure-sensitive adhesive compositions using this type of macromonomer have been proposed.

  For example, Patent Document 1 discloses a macromonomer having a number average molecular weight of 1,000 to 100,000 and a glass transition temperature of −20 ° C. or less, as a resin composition for a pressure-sensitive adhesive having good pressure-sensitive adhesive properties such as tack, adhesive strength, and cohesive strength. It consists of a radically polymerizable monomer having a hydroxyl group or a carboxyl group and a graft copolymer obtained by radical polymerization of other monomers, and the glass transition temperature of the trunk polymer is higher than the glass transition temperature of the branch polymer. A resin composition for an adhesive is disclosed.

  Patent Document 2 discloses a (meth) acryloyl group-containing macromonomer having a glass transition temperature of 40 ° C. or higher and a number average molecular weight of 2000 to 20000 as a method for improving durability and removability under high temperature and high humidity conditions. 0.2 to 3 parts by mass, 57 to 98.8 parts by mass of alkyl (meth) acrylate, 1 to 20 parts by mass of a functional group-containing monomer, and 0 to another monomer copolymerizable with at least the alkyl (meth) acrylate An adhesive using a copolymer (weight average molecular weight of 500,000 to 2,000,000) with 20 parts by mass is disclosed.

  In Patent Document 3, it can be easily bonded to various adherends, and can be cured after bonding to exert adhesive strength similar to that of an adhesive. As an adhesive composition that does not easily cause sticking of the adhesive and adhesion between cut surfaces, an alkyl (meth) acrylate monomer and a number average molecular weight Mn occupying 1 to 30% by mass of all monomer components are 1000 to 200000, glass A curable adhesive composition comprising an acrylic adhesive polymer obtained by copolymerizing a macromonomer having a transition point Tg of 30 to 150 ° C., a photocationic polymerizable compound, and a photocationic photopolymerization initiator. Is disclosed.

  In Patent Document 4, even if the adhesive layer of the adhesive tape contains a high content of filler, it has excellent adhesiveness and maintains the adhesiveness even when exposed to high temperatures. As a pressure adhesive, a (meth) acrylic copolymer having a (meth) acrylic copolymer as a backbone polymer and a (meth) acrylic macromonomer as a branch polymer, a (meth) acrylic graft copolymer, a crosslinking agent, and a filler are contained. A pressure sensitive adhesive characterized by the following has been proposed.

In Patent Document 5, in a normal state, that is, in a room temperature state, it can be provided with a peelable adhesiveness (referred to as “tackiness”), and has fluidity when heated to a temperature capable of hot melting. As a pressure-sensitive adhesive resin composition that can be filled to every corner following the stepped portion of the bonding surface, and finally adherends can be firmly adhered to each other, an acrylic copolymer (A) A pressure-sensitive adhesive resin composition containing 100 parts by mass, a crosslinking agent (B) 0.5 to 20 parts by mass, and a crosslinking initiator (C) 0.1 to 5 parts by mass, and an acrylic resin The copolymer (A) is a graft copolymer having a weight average molecular weight of 5.0 × 10 ⁴ to 5.0 × 10 ⁵ , and is derived from (meth) acrylic acid ester as a trunk component of the graft copolymer. The graft copolymer Containing a repeating unit derived from a macromonomer having a number average molecular weight of 5.0 × 10 ² or more and less than 6.0 × 10 ³ as a branch component of the acrylic copolymer (A) A pressure-sensitive adhesive resin composition containing 0.1 to 3 mol% in the inside is disclosed.

  Patent Document 6 discloses that a weight average molecular weight obtained by polymerizing a monomer mixture containing a macromonomer (a) having a number average molecular weight of 500 or more and less than 6000 and a vinyl monomer (b) is 50,000. A pressure-sensitive adhesive composition containing a (meth) acrylic copolymer (A) that is ˜1 million, and a pressure-sensitive adhesive sheet using this pressure-sensitive adhesive composition are disclosed.

  In Patent Document 7, the sheet-like shape can be maintained at room temperature, and can be provided with a sticking property that can be peeled off. A new method for producing a laminate for constituting an image display device that can be cross-linked and firmly bonded to each other is disclosed.

  Patent Document 8 discloses a photo-curing property that can be cured even if there is a place where light is difficult to reach, such as a print concealing portion, and can be cured even if the pressure-sensitive adhesive sheet has a certain thickness. An adhesive sheet is disclosed.

  In Patent Document 9, two optical device constituent members are separated from an optical device constituent laminate formed by pasting two optical device constituent members once through a transparent adhesive material, thereby forming an optical device constituent member. A method for recycling a member is disclosed.

  In patent document 10, in the bonding of the image display apparatus constituent member, foreign matter mixing at the interface between the pressure-sensitive adhesive layer and the release layer, and transfer transfer of the release agent to the pressure-sensitive adhesive layer can be suppressed. An adhesive sheet laminate excellent in durability is disclosed.

Japanese Patent Laid-Open No. 1-20312 Japanese Unexamined Patent Publication No. Hei 8-209090 JP 11-158450 A JP 2011-219582 A JP2015-105296A International Publication No. 2015 / 080244A1 International Publication No. 2015 / 137178A1 International Publication No. 2016 / 024618A1 International Publication No. 2016 / 002763A1 International Publication No. 2016 / 088697A1

  The present invention further provides a photocurable composition as disclosed above, that is, a photocurable composition having a (meth) acrylic copolymer containing a macromonomer as a structural unit and a crosslinking agent. By heating to a temperature at which hot-melting is possible by improving, it is possible to fill up every corner following the uneven part of the bonding surface, and after photocuring, adherends can be bonded more firmly It is intended to provide a new photocurable composition that can be produced.

The present invention is a photocurable composition containing a (meth) acrylic copolymer (A) containing a macromonomer as a structural unit, a crosslinking agent (B), and a crosslinking initiator (C), and a small-angle X-ray A photocurable composition is proposed in which the half width X1 (nm ⁻¹ ) of a one-dimensional scattering profile in scattering measurement is 0.05 <X1 <0.30.

  According to the photocurable composition proposed by the present invention, it is possible to exhibit self-adhesiveness (referred to as “tackiness”) while maintaining a sheet shape at room temperature, and when heated in an uncrosslinked state, it softens or flows. For example, it can be softened or flowed by being heated to a temperature higher than the glass transition temperature of the macromonomer, and can be filled up to every corner following the uneven portion of the bonding surface. Furthermore, since excellent cohesive force can be exhibited by photocuring, adherends can be firmly bonded to each other.

  An example of the embodiment of the present invention will be described below. However, the present invention is not limited to the following embodiment.

[The present photocurable composition]
The composition according to an example of the embodiment of the present invention (referred to as “the present photocurable composition”) includes a (meth) acrylic copolymer (A) containing a macromonomer as a structural unit, and a crosslinking agent (B). And a cross-linking initiator (C), wherein the half-value width X1 (nm ⁻¹ ) of the one-dimensional scattering profile in the small-angle X-ray scattering measurement is 0.05 <X1 <0.30. It is a photocurable composition characterized by these.
The above-mentioned “contains a macromonomer as a structural unit” means that a (meth) acrylic copolymer (A) is included in addition to a case where a macromonomer is included as a copolymer component of the (meth) acrylic copolymer (A). This includes the case where it is contained as a structural unit other than the copolymer component, such as when it is contained as an additional bond component.

This photocurable composition has a structure in which at least one of the crosslinking agent (B) and the crosslinking initiator (C) is bonded to the (meth) acrylic copolymer (A). Is preferred.
If at least one of the crosslinking agent (B) and the crosslinking initiator (C) is bonded to the (meth) acrylic copolymer (A), the bonded crosslinking agent (B) or crosslinking initiator (C) Bleed-out can be suppressed. Moreover, since at least one of the crosslinking agent (B) and the crosslinking initiator (C) is bonded to the (meth) acrylic copolymer (A), the reaction efficiency of the photocrosslinking reaction is promoted, A photocured product with higher cohesion can be obtained.
Furthermore, if at least one of the crosslinking agent (B) and the crosslinking initiator (C) is bonded to the (meth) acrylic copolymer (A), the (meth) acrylic copolymer (A) is crosslinked. Since it is possible to intentionally design the location to be performed, it becomes easy to control the half width of the one-dimensional scattering profile in the small-angle X-ray scattering measurement defined in the present invention.
Here, the term “bonded to the (meth) acrylic copolymer (A)” means that the crosslinking agent (B) or the crosslinking initiator (C) and the (meth) acrylic copolymer (A) Refers to a state in which is bound by a chemical bond including a covalent bond, an ionic bond and a metal bond.

As described above, the present photocurable composition is characterized in that the half width X1 (nm ⁻¹ ) of the one-dimensional scattering profile in the small-angle X-ray scattering measurement is 0.05 <X1 <0.30.
Small-angle X-ray scattering measurement is a technique for obtaining nanoscale (1 to 100 nm) structural information by observing scattered X-rays having a scattering angle of several degrees or less (specifically, for example, 10 ° or less).
Therefore, a composition in which a one-dimensional scattering profile can be observed in small-angle X-ray scattering measurement means that the composition is not in a state where a one-dimensional scattering profile is not observed in small-angle X-ray scattering measurement. In addition, as long as a one-dimensional scattering profile can be observed in small-angle X-ray scattering measurement, the shape and state of the present photocurable composition are not limited.

The (meth) acrylic copolymer (A) in the present photocurable composition is a copolymer containing a macromonomer as a structural unit. In general, a copolymer having a macromonomer as a structural unit forms a graft copolymer or a block copolymer. When the macromonomer has one polymerizable group, the graft copolymer is usually formed by addition, condensation or copolymerization with another monomer. In addition, when the macromonomer has two polymerizable groups, the block monomer is usually formed by addition, condensation or copolymerization with other monomers. In general, it is known that a graft copolymer or a block copolymer forms a (micro) phase separation structure.
The half width of the one-dimensional scattering profile in the small-angle X-ray scattering measurement for the present photocurable composition is defined by the composition containing the (meth) acrylic copolymer (A) as described above (micro). It can be considered as a measure of the “phase separation state” of the phase separation structure. That is, for example, the trunk component and the branch component in the graft copolymer, or the individual block components in the block copolymer form a microscopically separated state as different “phases”.
Here, when the half-value width of the one-dimensional scattering profile in the small-angle X-ray scattering measurement is large (wide), it means that the peak is broad, and each phase separated as compared with the case where the half-value width is small. This means that the density difference between phases is small or the phase separation structure is not uniform.
On the other hand, the smaller (narrower) the half-value width means that the peak is sharper. Compared with the case where the half-value width is large, the density difference of each phase that is phase-separated is clearer or the phase separation structure is It means more uniform.
Therefore, in the present photocurable composition, by controlling the half width within a specific range, each phase phase-separated microscopically can separately bear different adhesive properties.
Therefore, it can be considered that it has become possible to combine characteristics that are generally difficult to achieve.

  In the following description, the term “branch component” and “trunk component” may be used to explain a graft copolymer as an example. In a block copolymer, this is referred to as “each block component” (for example, “block component”). Component A ”and“ Block component B ”) may be read.

From the above viewpoint, in the present photocurable composition, the half-value width X1 of the one-dimensional scattering profile in the small-angle X-ray scattering measurement is such that the branching component composed of the macromonomer in the copolymer containing the macromonomer as a constituent unit The (micro) phase separation structure formed with the trunk component can be used as an indicator of the state after changing depending on the crosslinking agent or photoinitiator to be formulated.
Therefore, in the present photocurable composition, when 0.05 <X1 <0.30, the conventionally disclosed photocurable composition as described above, that is, a macromonomer is included as a structural unit (meta ) Compared to the conventional photocurable composition having an acrylic copolymer and a cross-linking agent, it is possible to achieve a higher level of tackiness and shape stability, both of which are contradictory properties, and to improve handling properties. An effect can be obtained.

  From this point of view, in the present photocurable composition, the half width X1 of the one-dimensional scattering profile in the small-angle X-ray scattering measurement is preferably 0.05 <X1 <0.30, and in particular, 0.06 <X1 or X1. <0.27, more preferably 0.08 <X1 or X1 <0.25, and even more preferably 0.11 <X1 or X1 ≦ 0.23.

  From the above, the half width X1 is any of 0.05 <X1 <0.30, 0.05 <X1 <0.27, 0.05 <X1 <0.25 or 0.05 <X1 ≦ 0.23. Preferably, 0.06 <X1 <0.30, 0.06 <X1 <0.27, 0.06 <X1 <0.25, or 0.06 <X1 ≦ 0.23 It is more preferable that any one of 0.08 <X1 <0.30, 0.08 <X1 <0.27, 0.08 <X1 <0.25, or 0.08 <X1 ≦ 0.23. It is more preferable that 0.11 <X1 <0.30, 0.11 <X1 <0.27, 0.11 <X1 <0.25, or 0.11 <X1 ≦ 0.23. It is most preferable that it is either.

In the present photocurable composition, as a main means for adjusting the half-value width X1 of the one-dimensional scattering profile in the small-angle X-ray scattering measurement, the structure of the (meth) acrylic copolymer (A) as the base polymer Examples include means for adjusting the composition, molecular weight, etc., and adjusting and selecting the type and amount of the crosslinking agent (B) and the crosslinking initiator (C). However, it is not limited to such means. The “base polymer” refers to a main component contained in the photocurable composition, and the “main component” refers to a component contained in excess of 40% by mass of the photocurable composition.
Here, the selection of the structure of the (meth) acrylic copolymer (A) can be, for example, selection of whether it is a graft copolymer or a block copolymer.

Examples of the adjustment of the composition of the (meth) acrylic copolymer (A) include adjustment of the composition of the trunk component and the branch component (each block component in the case of a block copolymer).
Specifically, the glass transition temperature (Tg) of the phase based on the branch component and the phase based on the trunk component of the (meth) acrylic copolymer (A) is adjusted, or the compatibility parameter of the branch component and the trunk component is set. The half width can also be controlled by optimizing the balance or optimizing the balance between the hydrophilicity and hydrophobicity of the branch component and the trunk component. For example, the half-width can be controlled by forming a phase having a high Tg as a branch component and a phase having a low Tg as a trunk component.
As described above, the graft polymer is used to optimize the balance of the compatibility between the branch component and the trunk component, thereby controlling the half width and forming the optimum phase separation state, thereby improving the tack and hot melt properties. Can be combined.

Examples of the adjustment of the types of the crosslinking agent (B) and the crosslinking initiator (C) include adjusting the compatibility with the hydrophilic component constituting the (meth) acrylic copolymer (A). . The crosslinking agent (B) and the crosslinking initiator (C) are either a trunk component and a branch component (each block component in the case of a block copolymer) formed by the (meth) acrylic copolymer (A) or By making the component highly compatible with both phases and adjusting the addition amount, the trunk component and branch component (in the case of a block copolymer, each of the (meth) acrylic copolymer (A)) The compatibility of the block component) can be adjusted to control the phase separation state, that is, the half width of the one-dimensional scattering profile.
Among them, as the method for adjusting the half width X1 of the present photocurable composition, as described later, the type and content ratio of the functional group of the monomer constituting the trunk component and the branch component is optimized, It is effective to optimize the (meth) acrylic copolymer (A) by optimizing the molecular weight and to adjust the type and amount of the crosslinking agent (B) and the crosslinking initiator (C).

  Furthermore, in this photocurable composition, in order to adjust the said half value width X1 to a preferable range, it becomes the main of (1) (meth) acrylic-type copolymer (A), for example so that it may mention in detail later. As the copolymer component (main component), it is preferable to use a (meth) acrylic monomer or vinyl monomer having 5 or more carbon atoms, especially 8 or more, of which 9 or more, particularly 10 or more. Specifically, it is preferable to select from the examples of monomers contained in the stem component of the acrylic copolymer (A1) described later.

  (2a) It is preferable to use a hydrophilic component as the copolymerizable component (trunk component) other than the (meth) acrylic monomer or vinyl monomer. Specifically, it is preferable to select from the examples of hydrophilic monomers contained in the trunk component of the acrylic copolymer (A1) described later. In addition, it is more preferable that (2b) the hydrophilic component is contained in a mass ratio of 0.1 to 20 with respect to the copolymer component (trunk component) 100 to increase the hydrophilicity of the trunk component.

  Further, as a branch component of (3a) (meth) acrylic copolymer (A), a (meth) acrylic monomer or vinyl monomer component having 4 or less carbon atoms is contained in a mass ratio of 1 to 100 with respect to trunk component 100. It is preferable to adjust the microphase separation state formed by the trunk component phase and the branch component phase. In addition, as a branching component of (3b) (meth) acrylic copolymer (A), a (meth) acrylic monomer or vinyl monomer component having a cyclic structure, It is preferable to adjust the microphase separation state formed by the trunk component phase and the branch component phase.

  Furthermore, it is preferable to use a hydroxyl group-containing compound having high compatibility with the hydrophilic component as (4a) the crosslinking agent (B). Specifically, it is preferable to select from the examples of the crosslinking agent (B) described later. In addition, (4b) 0.05 to 30 parts by mass of the crosslinking agent (B) is added to 100 parts by mass of the (meth) acrylic copolymer to appropriately adjust the polarity of the phase composed of the trunk component. More preferably.

  As mentioned above, the phase-separated structure which a trunk component and a branch component comprise can be adjusted by selecting said (1)-(4b) each independently suitably. Among them, among the methods (1) to (4b), (1) and (2a) and / or (2b) are combined, or (1) and (3a) and / or (3b) are combined. It is preferable to combine (1) with (3a) and / or (3b) with (4a) and / or (4b), and adopt all methods (1) to (4b). Is most preferred. However, it is not limited to this method.

  As described above, since an optimal phase separation state may be formed by using the graft polymer and optimizing the compatibility balance between the branch component and the trunk component, other than the above, for example, By using a hydrophobic component as the main copolymerizable component (trunk component) of the polymer (A) and using a hydrophilic component as the branch component of the copolymer (B), the half width X1 is It can also be controlled.

This photocurable composition has a half-value width X2 (nm ⁻¹ ) of a one-dimensional scattering profile in a small angle X-ray scattering measurement of 0.05 <X2 <when a light of 4000 mJ / m ² is irradiated as an integrated light irradiation amount. More preferably, it is 0.25.
In the present photocurable composition, the one-dimensional scattering profile of the photocurable composition after irradiation with light of 4000 mJ / m ² as an integrated light irradiation amount, that is, the one-dimensional scattering profile of the present photocurable composition after irradiation with light. When half width X2 (nm ⁻¹ ) is 0.05 <X2 <0.25, in addition to the effect when X1 is in the predetermined range, the effect of obtaining a high cohesive force in the composition after photocuring Can be obtained. The wavelength of the irradiation light is preferably a wavelength to which a crosslinking initiator (C) described later is sensitive.

From this point of view, in the present photocurable composition, the half-value width X2 (nm ⁻¹ ) of the one-dimensional scattering profile in the small-angle X-ray scattering measurement when the accumulated light irradiation amount is 4000 mJ / m ² is 0. 05 <X2 <0.25, preferably 0.06 <X2 or X2 <0.24, of which 0.08 <X2 or X2 <0.22, and of which 0.10 <X2 or X2 It is even more preferable that it is <0.20.

  From the above, the half width X2 is any of 0.05 <X2 <0.25, 0.05 <X2 <0.24, 0.05 <X2 <0.22 or 0.05 <X2 <0.20. Preferably, 0.06 <X2 <0.25, 0.06 <X2 <0.24, 0.06 <X2 <0.22 or 0.06 <X2 <0.20. It is more preferable that any one of 0.08 <X2 <0.25, 0.08 <X2 <0.24, 0.08 <X2 <0.22 or 0.08 <X2 <0.20 among them. More preferably, among them, 0.10 <X2 <0.25, 0.10 <X2 <0.24, 0.10 <X2 <0.22, or 0.10 <X2 <0.20. It is most preferable that it is either.

In the present photocurable composition, means for adjusting the half-value width X2 (nm ⁻¹ ) of the one-dimensional scattering profile in the small-angle X-ray scattering measurement when irradiating light of 4000 mJ / m ² as the integrated light irradiation amount, This is the same as the means for adjusting the half width X1. For example, the structure, composition, molecular weight, etc. of the (meth) acrylic copolymer (A) as the base polymer are adjusted, and the type and amount of the crosslinking agent (B) and crosslinking initiator (C) are adjusted or selected. The means to do can be mentioned. However, it is not limited to such means.

  Furthermore, in the present photocurable composition, in order to adjust the half width X2 to a preferable range, as will be described in detail later, (1) the main copolymer of the (meth) acrylic copolymer (A). As the polymerization component (main component), it is preferable to use a (meth) acrylic monomer or vinyl monomer having 5 or more carbon atoms, particularly 8 or more, of which 9 or more, particularly 10 or more. Specifically, it is preferable to select from the examples of monomers contained in the stem component of the acrylic copolymer (A1) described later.

  (2a) It is preferable to use a hydrophilic component as the copolymer component (trunk component) other than the (meth) acrylic monomer or vinyl monomer. Specifically, it is preferable to select from the examples of hydrophilic monomers contained in the trunk component of the acrylic copolymer (A1) described later. In addition, it is more preferable that (2b) the hydrophilic component is contained in a mass ratio of 0.1 to 20 with respect to the copolymer component (trunk component) 100 to increase the hydrophilicity of the trunk component.

  Further, as a branch component of (3a) (meth) acrylic copolymer (A), a (meth) acrylic monomer or vinyl monomer component having 4 or less carbon atoms is contained in a mass ratio of 1 to 100 with respect to trunk component 100. It is preferable to adjust the microphase separation state formed by the trunk component phase and the branch component phase. In addition, as a branching component of (3b) (meth) acrylic copolymer (A), a (meth) acrylic monomer or vinyl monomer component having a cyclic structure, It is preferable to adjust the microphase separation state formed by the trunk component phase and the branch component phase.

  Furthermore, it is preferable to use a hydroxyl group-containing compound having high compatibility with the hydrophilic component as (4a) the crosslinking agent (B). Specifically, it is preferable to select from the examples of the crosslinking agent (B) described later. In addition, (4b) 0.05 to 30 parts by mass of the crosslinking agent (B) is added to 100 parts by mass of the (meth) acrylic copolymer to appropriately adjust the polarity of the phase composed of the trunk component. More preferably.

  As mentioned above, the phase-separated structure which a trunk component and a branch component comprise can be adjusted by selecting said (1)-(4b) each independently suitably. Among them, among the methods (1) to (4b), (1) and (2a) and / or (2b) are combined, or (1) and (3a) and / or (3b) are combined. It is preferable to combine (1) with (3a) and / or (3b) with (4a) and / or (4b), and adopt all methods (1) to (4b). Is most preferred. However, it is not limited to this method.

  As described above, since an optimal phase separation state may be formed by using the graft polymer and optimizing the compatibility balance between the branch component and the trunk component, other than the above, for example, By using a hydrophobic component as the main copolymerizable component (trunk component) of the polymer (A) and using a hydrophilic component as the branch component of the copolymer (B), the half width X2 is reduced. It can also be controlled.

In addition, as above-mentioned, the shape and state of this photocurable composition are not limited. When the light of 4000 mJ / m ² is not uniformly irradiated to the photocurable composition, it is determined that the photocurable composition is formed into a sheet having a thickness of 150 μm as a reference (measurement target). That's fine.

The photocurable composition preferably has adhesiveness at 20 ° C. and has a property of softening or fluidizing at 50 to 100 ° C.
As described above, the present photocurable composition can have such properties by using the (meth) acrylic copolymer (A1) described later as the base resin.

<(Meth) acrylic copolymer (A)>
As a (meth) acrylic copolymer (A) containing a macromonomer as a structural unit, a (meth) acrylic copolymer (A1) comprising a graft copolymer having a macromonomer as a branch component is taken as an example. Can do.
Since the present photocurable composition is crosslinked by the action of the crosslinking agent (B) and the crosslinking initiator (C), from the viewpoint of its efficiency, the (meth) acrylic copolymer (A) is a graft copolymer. Is preferred.

  If this photocurable composition is produced using the (meth) acrylic copolymer (A1) as a base resin, the half-value width of the one-dimensional scattering profile in the small-angle X-ray scattering measurement defined in the present invention can be controlled. It becomes easy. That is, it is one mode of an achievement means that makes the half width within the range. For this reason, this photocurable composition can exhibit self-adhesiveness (self-adhesiveness) while maintaining a predetermined shape, for example, a sheet shape, at room temperature, and is softened or fluidized when heated in an uncrosslinked state. It has melt properties and can be photocured, and after photocuring, it can be bonded by exhibiting excellent cohesive force.

  Therefore, if the (meth) acrylic copolymer (A1) is used as the base polymer of the present photocurable composition, it exhibits adhesiveness at room temperature (20 ° C.) even in an uncrosslinked state, and 50 It can be provided with a property of softening or fluidizing when heated to a temperature of ˜90 ° C., more preferably 60 ° C. or higher or 80 ° C. or lower.

(Stem component)
The glass transition temperature of the (co) polymer constituting the trunk component of the (meth) acrylic copolymer (A1) is preferably −70 to 0 ° C.
In this case, the glass transition temperature of the (co) polymer component constituting the trunk component is a polymer glass obtained by polymerizing only the monomer component constituting the trunk component of the (meth) acrylic copolymer (A1). Refers to the transition temperature. Specifically, it means a value calculated by the Fox formula from the glass transition temperature and the composition ratio of the polymer obtained from the homopolymer of each component of the (co) polymer. The polymer composed only of the trunk component may be either a homopolymer or a copolymer.

The Fox calculation formula is the following formula, which is described in Polymer Handbook [Polymer HandBook, J. Mol. Brandrup, Interscience, 1989].
1 / (273 + Tg) = Σ (Wi / (273 + Tgi))
[Wherein Wi represents the weight fraction of monomer i, and Tgi represents Tg (° C.) of the homopolymer of monomer i. ]

The glass transition temperature of the (co) polymer constituting the main component of the (meth) acrylic copolymer (A1) is the flexibility of the present photocurable composition at room temperature, and the glass transition temperature to the adherend. Since the wettability of the photocurable composition, that is, the adhesiveness is affected, the glass transition temperature of the present photocurable composition is −70 ° C. in order to obtain appropriate adhesiveness (tackiness) at room temperature. It is preferably ˜0 ° C., more preferably −65 ° C. or more or −5 ° C. or less, and particularly preferably −60 ° C. or more or −10 ° C. or less.
However, even if the glass transition temperature of the (co) polymer is the same temperature, the viscoelasticity can be adjusted by adjusting the molecular weight. For example, it can be made more flexible by reducing the molecular weight of the trunk component.

  Examples of the monomer contained in the trunk component of the (meth) acrylic copolymer (A1) include (meth) acrylic acid ester monomers, such as methyl (meth) acrylate, ethyl (meth) acrylate, and propyl. (Meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meta ) Acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (Meth) acrylate, isononyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (Meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, 3,5,5-trimethylcyclohexane acrylate, p-cumylphenol ethylene oxide modification (Meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate Benzyl (meth) acrylate, and the like.

Hydroxyl-containing (meth) such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, glycerol (meth) acrylate, etc., in which a hydrophilic group is bonded to these (meth) acrylic acid ester monomers Acrylate or the like can also be used.
Also, (meth) acrylic acid, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) Acryloyloxypropylphthalic acid, 2- (meth) acryloyloxyethylmaleic acid, 2- (meth) acryloyloxypropylmaleic acid, 2- (meth) acryloyloxyethylsuccinic acid, 2- (meth) acryloyloxypropylsuccinic acid, Carboxyl group-containing monomers such as crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, monomethyl itaconic acid can also be used.

Furthermore, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; epoxy group-containing monomers such as glycidyl (meth) acrylate, glycidyl α-ethyl acrylate, and 3,4-epoxybutyl (meth) acrylate Amino group-containing (meth) acrylic acid ester monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; (meth) acrylamide, dimethyl (meth) acrylamide, diethyl (meth) acrylamide, (meth) acryloyl Morpholine, hydroxyethyl (meth) acrylamide, isopropyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide / methyl chloride, (meth) acrylamide, Nt- Acrylamide monomers such as chill (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, diacetone (meth) acrylamide; maleic acid amide, maleimide, etc. Monomers containing amide groups of: heterocyclic basic monomers such as vinyl pyrrolidone, vinyl pyridine and vinyl carbazole; 2-isocyanatoethyl (meth) acrylate, 2- (2- (meth) acryloyloxyethyloxy) ethyl isocyanate An isocyanate group such as narate, 2- (0- [1′-methylpropylideneamino] carboxyamino) ethyl (meth) acrylate, 2-[(3,5-dimethylpyrazolyl) carbonylamino] ethyl (meth) acrylate, or The Monomers containing a polyisocyanate group; monomers containing an ultraviolet absorbing group such as 2- [2-hydroxy-5- [2-((meth) acryloyloxy) ethyl] phenyl] -2H-benzotriazole are used. You can also
In addition, styrene, t-butylstyrene, α-methylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, alkyl vinyl ether, hydroxyalkyl vinyl ether, alkyl, which can be copolymerized with the above acrylic monomers and methacrylic monomers. Various vinyl monomers such as vinyl monomers can also be used as appropriate.

Further, the trunk component of the (meth) acrylic copolymer (A1) preferably contains a hydrophobic monomer and a hydrophilic monomer as structural units.
When the trunk component of the (meth) acrylic copolymer (A1) is composed only of a hydrophobic monomer, a tendency to wet-heat whitening is observed, and thus hydrophilic monomers are also introduced into the trunk component to prevent wet-heat whitening. Is preferred.

  Specifically, as the main component of the (meth) acrylic copolymer (A1), a hydrophobic (meth) acrylate monomer, a hydrophilic (meth) acrylate monomer, and a polymerizable functional group at the end of the macromonomer. A copolymer component formed by random copolymerization with a group can be exemplified.

Here, examples of the hydrophobic (meth) acrylate monomer include ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. , Sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) ) Acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate Rate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate , Isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and methyl methacrylate.
Examples of the hydrophobic vinyl monomer include alkyl vinyl esters such as vinyl acetate, styrene, t-butyl styrene, α-methyl styrene, vinyl toluene, and alkyl vinyl monomers.

Among them, the number of carbon atoms is 5 or more from the viewpoint of easily forming an appropriate phase separation structure with a phase formed by a branch component, which will be described later, and imparting appropriate adhesiveness (tackiness) to the present photocurable composition. It is preferably 8 or more, more preferably 9 or more, and particularly preferably 10 or more alkyl (meth) acrylates.
For example, when this photocurable composition is used for a member having a touch sensor function, a photocurable composition having a low relative dielectric constant is used to absorb the change in touch detection sensitivity and suppress the generation of noise in the detection signal. It may be required. At this time, from the viewpoint of adjusting the relative dielectric constant of the photocurable composition and / or a cured product obtained by photocuring the photocurable composition to a low level, the hydrophobic monomer has 5 or more carbon atoms, especially 8 Above all, it is preferable to use 9 or more, particularly 10 or more alkyl (meth) acrylates.
Here, as an alkyl (meth) acrylate having 8 or more carbon atoms, for example, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, t-butylcyclohexyl ( (Meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) ) Acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and the like.

  Examples of the hydrophilic monomer include methyl acrylate, tetrahydrofurfuryl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and glycerol (meth) acrylate. Hydroxyl group-containing (meth) acrylate, (meth) acrylic acid, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid 2- (meth) acryloyloxypropylphthalic acid, 2- (meth) acryloyloxyethylmaleic acid, 2- (meth) acryloyloxypropylmaleic acid, 2- (meth) acryloyloxyethylsuccinic acid, -Carboxylic group-containing monomers such as (meth) acryloyloxypropyl succinic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate and monomethyl itaconic acid, and acid anhydride groups such as maleic anhydride and itaconic anhydride Monomer, Epoxy group-containing monomer such as glycidyl (meth) acrylate, glycidyl α-ethyl acrylate, 3,4-epoxybutyl (meth) acrylate, alkoxypolyalkylene glycol (meth) such as methoxypolyethylene glycol (meth) acrylate In addition to acrylate, (meth) acrylamide, dimethyl (meth) acrylamide, diethyl (meth) acrylamide, (meth) acryloylmorpholine, hydroxyethyl (meth) acrylamide, isopropyl (meth) acrylamide, di Methylaminopropyl (meth) acrylamide, phenyl (meth) acrylamide, Nt-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, (Meth) acrylamide monomers such as diacetone (meth) acrylamide can be used.

  Among the above, from the viewpoint of improving the adhesion to the adherend while preventing wet heat whitening of the present photocurable composition, as the hydrophilic monomer, a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an acid It is preferable to use an anhydride group-containing monomer or a (meth) acrylamide monomer.

  On the other hand, when this photocurable composition is used for a corrosive member such as a metal or metal oxide, a cured product obtained by photocuring the photocurable composition and / or the photocurable composition. In order to prevent corrosion deterioration of the adherend due to, it is preferable to use a hydrophilic component that does not contain a highly acidic carboxyl group or acid anhydride. From such a viewpoint, as the hydrophilic monomer, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyl-containing (meth) acrylate such as glycerol (meth) acrylate, (Meth) acrylamide, dimethyl (meth) acrylamide, diethyl (meth) acrylamide, (meth) acryloylmorpholine, hydroxyethyl (meth) acrylamide, isopropyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, phenyl (meth) acrylamide, Nt-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acryl Bromide, diacetone (meth) acrylamide, (meth) preferably used acrylamide monomer.

(Branch component: macromonomer)
The (meth) acrylic copolymer (A1) preferably contains a macromonomer as a structural unit by introducing a macromonomer as a branch component of the graft copolymer.
The macromonomer is a polymer monomer having a terminal polymerizable functional group and a high molecular weight skeleton component.

The glass transition temperature (Tg) of the macromonomer is preferably higher than the glass transition temperature of the copolymer component constituting the (meth) acrylic copolymer (A1).
Specifically, the glass transition temperature (Tg) of the macromonomer affects the heating and melting temperature (hot melt temperature) of the present photocurable composition, and is preferably 30 ° C. to 120 ° C., particularly 40 ° C. Above or 110 ° C. or less, more preferably 50 ° C. or more or 100 ° C. or less.
If the macromonomer is such a glass transition temperature (Tg), it is possible to maintain excellent processability and storage stability by adjusting the molecular weight, and to adjust so as to hot-melt in the vicinity of 50 ° C to 80 ° C. be able to.
The glass transition temperature of the macromonomer means the glass transition temperature of the macromonomer itself and can be measured with a differential scanning calorimeter (DSC).

Further, at room temperature, the branch components are attracted to each other and can maintain a state where they are physically cross-linked as a pressure-sensitive adhesive composition, and the physical cross-linking is released by heating to an appropriate temperature. In order to obtain fluidity, it is also preferable to adjust the molecular weight and content of the macromonomer.
From this point of view, the macromonomer is preferably contained in the (meth) acrylic copolymer (A1) at a ratio of 5% by mass to 30% by mass, particularly 6% by mass or more, or 25% by mass or less. It is preferably 8% by mass or more or 20% by mass or less.

  The number average molecular weight of the macromonomer is preferably 500 to 100,000, more preferably less than 8000, particularly 800 or more and less than 7500, and particularly preferably 1000 or more and less than 7000.

  As the macromonomer, a generally produced one (for example, a macromonomer manufactured by Toa Gosei Co., Ltd.) can be appropriately used.

The high molecular weight skeleton component of the macromonomer is preferably composed of an acrylic polymer or a vinyl polymer.
Examples of the high molecular weight skeleton component of the macromonomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) Acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, t-butylcyclohexyl ( Acrylate), decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) ) Acrylate, isobornyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, 3,5,5-trimethylcyclohexane acrylate, p-cumylphenol ethylene oxide modified (meth) acrylate, dicyclopentanyl (meth) acrylate, di Cyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, benzyl (meth) acrylate, hydroxyalkyl (meth) acrylate, (meth) (Meth) acrylate monomers such as crylic acid, glycidyl (meth) acrylate, alkoxyalkyl (meth) acrylate, alkoxypolyalkylene glycol (meth) acrylate, styrene, t-butylstyrene, α-methylstyrene, vinyltoluene, alkylvinyl Various vinyl monomers such as monomers, alkyl vinyl esters, alkyl vinyl ethers, hydroxyalkyl vinyl ethers, (meth) acrylonitriles, (meth) acrylamides, N-substituted (meth) acrylamides, and the like are used alone or in combination of two or more. Can be used.

The macromonomer has a radically polymerizable group or a polymerizable functional group such as a hydroxyl group, an isocyanate group, an epoxy group, a carboxyl group, an amino group, an amide group, or a thiol group. As the macromonomer, those having a radical polymerizable group copolymerizable with other monomers are preferable. One or two or more radically polymerizable groups may be contained, and one of them is particularly preferred. When the macromonomer has a functional group, one or two or more functional groups may be contained, and one of them is particularly preferable. Further, either one of the radical polymerizable group and the functional group may be contained. In the case of containing both a radical polymerizable group and a functional group, a functional group other than any one of a functional group to be added to a polymer unit composed of another monomer, or a radical polymerizable group copolymerized with another monomer, or Two or more radically polymerizable groups may be used.
Therefore, as the terminal functional group of the macromonomer, for example, a radical polymerizable group such as methacryloyl group, acryloyl group, vinyl group, hydroxyl group, isocyanate group, epoxy group, carboxyl group, amino group, amide group, thiol group And the like.

Among them, the terminal functional group of the macromonomer is preferably one having a radical polymerizable group copolymerizable with other monomers. At this time, one or two or more radically polymerizable groups may be contained, and one is particularly preferable.
Even when the macromonomer has a functional group, one or two or more functional groups may be contained, and one of them is particularly preferable.
Moreover, the radical polymerizable group and the functional group may contain either one or both. In the case of containing both a radical polymerizable group and a functional group, a functional group other than any one of a functional group to be added to a polymer unit composed of another monomer, or a radical polymerizable group copolymerized with another monomer, or Two or more radically polymerizable groups may be used.

  The macromonomer can be produced by a known method. Macromonomer production methods include, for example, a method using a cobalt chain transfer agent, a method using an α-substituted unsaturated compound such as α-methylstyrene dimer as a chain transfer agent, and chemically bonding a polymerizable group. And a method by thermal decomposition. Among these, as a method for producing a macromonomer, a method using a cobalt chain transfer agent is preferable because it uses a catalyst having a small number of production steps and a high chain transfer constant.

(Production method)
The acrylic copolymer (A1) can be obtained, for example, by adding a specific macromonomer (a) to a polymer composed of a vinyl monomer (b), and also with a specific macromonomer (a) and It can also be obtained by polymerizing a monomer mixture containing the vinyl monomer (b).

<Crosslinking agent (B)>
The crosslinking agent (B) in the present photocurable composition is a control agent for the (micro) phase separation structure formed by the composition containing the (meth) acrylic copolymer (A), in other words, the present photocurable composition. It has a role as a control agent that adjusts the flexibility and cohesive strength of objects.

Examples of the crosslinking agent (B) include (meth) acryloyl group, epoxy group, isocyanate group, carboxyl group, hydroxyl group, carbodiimide group, oxazoline group, aziridine group, vinyl group, amino group, imino group, amide group, N- The crosslinking agent which has at least 1 sort (s) of crosslinkable functional group chosen from a substituted (meth) acrylamide group and an alkoxy silyl group can be mentioned, You may use 1 type or in combination of 2 or more types.
The crosslinkable functional group may be protected with a deprotectable protecting group.

Among these, polyfunctional (meth) acrylate is preferable from the viewpoint of easy control of the crosslinking reaction.
Examples of such polyfunctional (meth) acrylates include 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin di (meth) acrylate, glycerin glycidyl ether di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol A polyalkoxydi (meth) ) Acrylate, bisphenol F polyalkoxy di (meth) acrylate, polyalkylene glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, ε-caprolactone modified (2-hydroxyethyl) isocyanurate tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate , Propoxylated pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyethylene glycol di (meth) acrylate, tris (acryloxyethyl) isocyanurate, pentaerythritol tetra (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta ( Di) of ε-caprolactone adduct of hydroxypentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydroxypentylglycol dipentaglycol di (meth) acrylate, and hydroxybivalic acid neopenglycol In addition to UV-curable polyfunctional monomers such as (meth) acrylate, trimethylolpropane tri (meth) acrylate, alkoxylated trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and polyester (meth) In addition to polyfunctional acrylic oligomers such as acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, and polyether (meth) acrylate, polyfunctional acrylamide is listed. Rukoto can.

Among the above-described polyfunctional (meth) acrylic acid ester monomers, among the above-mentioned polyfunctional (meth) acrylic acid ester monomers, such as hydroxyl group, carboxyl group, amino group, amide group, etc. Polyfunctional monomers or oligomers containing polar functional groups are preferred. Among these, it is preferable to use a polyfunctional (meth) acrylic acid ester having a hydroxyl group or an amide group.
From the viewpoint of preventing wet heat whitening, it contains a hydrophobic acrylate monomer and a hydrophilic acrylate monomer as the trunk component of the (meth) acrylic acid ester copolymer (A1), that is, the graft copolymer. Furthermore, it is preferable to use a polyfunctional (meth) acrylic acid ester having a hydroxyl group as the crosslinking agent (B).
Moreover, in order to adjust effects, such as adhesiveness, heat-and-moisture resistance, and heat resistance, you may further add monofunctional or polyfunctional (meth) acrylic acid ester which reacts with a crosslinking agent (B).

  Moreover, as a crosslinking agent which has a 2 or more types of crosslinkable functional group, (meth) acrylic-acid glycidyl, alpha-ethyl acrylate glycidyl, (meth) acrylic-acid 3,4-epoxybutyl, 4-hydroxybutyl (meta ) Epoxy group-containing monomers such as acrylate glycidyl ether, 2-isocyanatoethyl (meth) acrylate, 2- (2- (meth) acryloyloxyethyloxy) ethyl isocyanate, (meth) acrylic acid 2- (0- [ In addition to monomers containing isocyanate groups or blocked isocyanate groups such as 1′-methylpropylideneamino] carboxyamino) ethyl and 2-[(3,5-dimethylpyrazolyl) carbonylamino] ethyl (meth) acrylate, vinyltrimethoxy Silane, vinyltriethoxysilane, 3-glyce Doxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3 -Various silane coupling agents, such as isocyanate propyl triethoxysilane, can be mentioned.

The crosslinking agent having two or more kinds of crosslinkable functional groups is a structure in which one crosslinkable functional group is reacted with a (meth) acrylic copolymer and bonded to the (meth) acrylic copolymer (A). You may take
By binding the crosslinking agent (B) to the (meth) acrylic copolymer (A), bleeding out of the crosslinking agent (B) and unexpected plasticization of the pressure-sensitive adhesive composition can be suppressed. Moreover, since the reaction efficiency of a photocrosslinking reaction is accelerated | stimulated because a crosslinking agent (B) is couple | bonded with a (meth) acrylic-type copolymer (A), the hardened | cured material with higher cohesion force can be obtained. .

  The content of the crosslinking agent (B) is such that the half-value width of the one-dimensional scattering profile in the small-angle X-ray scattering measurement is adjusted to an appropriate range to maintain an appropriate phase separation structure, and the flexibility and aggregation of the present photocurable composition From the viewpoint of balancing the force, it is preferable to contain 0.05 parts by weight or 30 parts by weight with respect to 100 parts by weight of the (meth) acrylic copolymer (A). Or it is preferable to contain in the ratio of 20 mass parts, and it is especially preferable that it is a ratio of 0.5 mass part or more or 15 mass parts or less among these, especially 1 mass part or more or 13 mass parts or less.

  This photocurable composition may further contain the monofunctional monomer which reacts with the crosslinkable functional group of a crosslinking agent (B). By containing a monofunctional monomer, the half-value width X1 of the one-dimensional scattering profile in the small-angle X-ray scattering measurement of the present photocurable composition is increased, the fluidity during hot melt is increased, It is possible to improve the adhesion to the body and the effect of suppressing wet heat whitening.

Such monofunctional monomers include, for example, alkyl (meth) acrylates such as methyl acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, glycerol (meth) acrylate, poly Hydroxyl group-containing (meth) acrylates such as alkylene glycol (meth) acrylate; (meth) acrylic acid, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- ( (Meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxypropyl phthalic acid, 2- (meth) acryloyloxyethyl maleic acid, 2- (meth) acryloyloxypropyl maleic acid, 2- (meta Carboxyl group-containing monomers such as acryloyloxyethyl succinic acid, 2- (meth) acryloyloxypropyl succinic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, monomethyl itaconic acid; maleic anhydride, itaconic anhydride Acid anhydride group-containing monomers such as tetrahydrofurfuryl (meth) acrylate, ether group-containing (meth) acrylates such as methoxypolyethylene glycol (meth) acrylate; (meth) acrylamide, dimethyl (meth) acrylamide, diethyl (meth) acrylamide , (Meth) acryloylmorpholine, hydroxyethyl (meth) acrylamide, isopropyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, phenyl (meth) acrylamide, (Meth) acrylamide monomers such as Nt-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide and diacetone (meth) acrylamide Etc.
Among these, from the viewpoint of improving the adhesion to the adherend and the effect of suppressing the moist heat whitening, it is preferable to use a hydroxyl group-containing (meth) acrylate or a (meth) acrylamide monomer.

<Crosslinking initiator (C)>
The crosslinking initiator (C) used in the present photocurable composition serves as a reaction initiation assistant in the crosslinking reaction of the crosslinking agent (B).

  As the cross-linking initiator, those currently known can be appropriately used. Among these, a photopolymerization initiator that is sensitive to ultraviolet rays having a wavelength of 380 nm or less is preferable from the viewpoint of easy control of the crosslinking reaction.

  On the other hand, a photopolymerization initiator that is sensitive to light having a wavelength longer than 380 nm can obtain a high photoreactivity, and when the sensitive light forms the photocurable composition into a sheet shape, It is preferable in that it can easily reach the deep part.

  Photopolymerization initiators are roughly classified into two types depending on the radical generation mechanism, a cleavage-type photopolymerization initiator that can cleave and decompose a single bond of the photopolymerization initiator itself to generate a radical, and a photoexcited initiator. It is roughly classified into a hydrogen abstraction type photopolymerization initiator which can form an exciplex with a hydrogen donor in the system and transfer hydrogen of the hydrogen donor.

Of these, the cleavage type photopolymerization initiator decomposes to generate another compound when generating radicals by light irradiation, and once excited, it does not function as a crosslinking initiator. For this reason, it does not remain as an active species in the pressure-sensitive adhesive after the crosslinking reaction is completed, and it is not likely to cause unexpected light degradation or the like in the pressure-sensitive adhesive, which is preferable.
On the other hand, a hydrogen abstraction type photopolymerization initiator does not generate a decomposition product like a cleavage type photopolymerization initiator during radical generation reaction by irradiation with active energy rays such as ultraviolet rays, so it is difficult to become a volatile component after the reaction is completed. This is useful in that damage to the body can be reduced.

  Examples of the cleavage type photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexyl phenyl ketone, and 2-hydroxy-2-methyl-1-phenyl-propane-1. -One, 1- (4- (2-hydroxyethoxy) phenyl) -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- [4- {4- (2-hydroxy- 2-methyl-propionyl) benzyl} phenyl] -2-methyl-propan-1-one, oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone), phenylglyoxy Methyl lick, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2- (4-methylbenzyl) -2 -Dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2- (dimethylamino) -2-[(4-Methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 1,2-octanedione, 1- (4- (phenylthio), 2- (o -Benzoyloxime)), 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -ethanone 1- (O-acetyloxime), bis (2,4,6-trimethyl) Benzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine Fins oxide, and bis (2,6-dimethoxybenzoyl) 2,4,4-trimethylpentyl phosphine oxide, their derivatives etc. may be mentioned.

Examples of the hydrogen abstraction type photopolymerization initiator include benzophenone, 4-methyl-benzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 3,3′-dimethyl-4-methoxybenzophenone, 4- (meta ) Acryloyloxybenzophenone, 4- [2-((meth) acryloyloxy) ethoxy] benzophenone, 4- (meth) acryloyloxy-4′-methoxybenzophenone, methyl 2-benzoylbenzoate, methyl benzoylformate, bis (2- Phenyl-2-oxoacetic acid) oxybisethylene, 4- (1,3-acryloyl-1,4,7,10,13-pentaoxotridecyl) benzophenone, thioxanthone, 2-chlorothioxanthone, 3-methylthioxanthone, 2 , 4-Dimethylthioxanthate , Anthraquinone, 2-methyl anthraquinone, 2-ethylanthraquinone, 2-tert-butyl anthraquinone, 2-aminoanthraquinone, etc. can be exemplified camphorquinone and derivatives thereof.
However, the photopolymerization initiator is not limited to the substances listed above. Any one of the photo-opening polymerization initiators listed above or a derivative thereof may be used, or two or more thereof may be used in combination.

  Among them, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine are highly sensitive to light and become dissociated and disappear after reaction. Acyl phosphine oxide photopolymerization initiators such as oxide, (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphine oxide are preferred.

  From the viewpoint of ease of reaction control and compatibility with an acrylic copolymer composed of a graft copolymer having a macromonomer as a branch component, benzophenone, 4-methyl-benzophenone as a crosslinking initiator (C), 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 3,3′-dimethyl-4-methoxybenzophenone, 4- (meth) acryloyloxybenzophenone, 4- [2-((meth) acryloyloxy) ethoxy] benzophenone 4- (meth) acryloyloxy-4′-methoxybenzophenone, methyl 2-benzoylbenzoate, methyl benzoylformate and the like are preferably used.

The content of the crosslinking initiator (C) is not particularly limited. As a standard, 0.1 to 10 parts by weight, particularly 0.5 parts by weight or more and 5 parts by weight or less, particularly 1 part by weight or more or 3 parts by weight or less, based on 100 parts by weight of the acrylic copolymer (A). It is preferable to contain in the ratio.
By setting the content of the crosslinking initiator (C) in the above range, an appropriate reaction sensitivity with respect to the active energy ray can be obtained.

Furthermore, it is also possible to use a sensitizer in addition to the crosslinking initiator (C) component.
The sensitizer is not particularly limited, and any sensitizer that can be used as a photopolymerization initiator can be used without any problem. Examples include aromatic amines, anthracene derivatives, anthraquinone derivatives, coumarin derivatives, thioxanthone derivatives, phthalocyanine derivatives, aromatic ketones such as benzophenone, xanthone, thioxanthone, Michler ketone, 9,10-phenanthraquinone, and derivatives thereof. be able to.

<Other ingredients>
This photocurable composition may contain the well-known component mix | blended with the normal adhesion composition as components other than the above. For example, tackifier resins, antioxidants, light stabilizers, metal deactivators, rust inhibitors, anti-aging agents, hygroscopic agents, hydrolysis inhibitors, antistatic agents, antifoaming agents, inorganic particles, etc. Various additives can be appropriately contained.
Moreover, you may contain a reaction catalyst (A tertiary amine type compound, a quaternary ammonium type compound, a lauric acid tin compound, etc.) suitably as needed.

<This adhesive sheet>
An adhesive sheet (referred to as “present adhesive sheet”) can be prepared from the photocurable composition.

The pressure-sensitive adhesive sheet may be a single-layer sheet or a multilayer sheet in which two or more layers are laminated.
When this pressure-sensitive adhesive sheet is a pressure-sensitive adhesive sheet having three or more layers, for example, when forming a pressure-sensitive adhesive sheet having a laminated structure including an intermediate layer and an outermost layer, the outermost layer is formed from the present photocurable composition. It is preferable to do.

When the pressure-sensitive adhesive sheet is formed into a laminated pressure-sensitive adhesive sheet having an intermediate layer and an outermost layer, the ratio of the thickness of each outermost layer to the thickness of the intermediate layer is 1: 1 to 1:20. Among these, a ratio of 1: 2 to 1:10 is more preferable.
If the thickness of the intermediate layer is within the above range, the contribution of the thickness of the pressure-sensitive adhesive layer in the laminate is not too large, and it is preferable that the workability relating to cutting and handling is not deteriorated because it is too flexible.
In addition, if the outermost layer is in the above range, it is preferable because the adhesion to the adherend and the wettability can be maintained without being inferior in conformity to unevenness and a bent surface.

(Thickness of this adhesive sheet)
With regard to the thickness of this adhesive sheet, it is possible to meet the demand for thinning by reducing the sheet thickness. On the other hand, if the sheet thickness is too thin, for example, if there is an uneven part on the adherend surface, it will follow the unevenness sufficiently. It may not be possible or it may not be able to exert sufficient adhesion.
From this viewpoint, the thickness of the pressure-sensitive adhesive sheet is preferably 20 μm to 500 μm, particularly preferably 25 μm or more or 350 μm or less, and particularly preferably 50 μm or more or 250 μm or less.

(Adhesive strength of this adhesive sheet)
This pressure-sensitive adhesive sheet is attached to glass and has a 180 ° peel strength against the glass when irradiated with light of 4000 mJ / m ² as an integrated light irradiation amount, that is, the 180 ° peel of the pressure-sensitive adhesive sheet after irradiation with light. The strength is preferably 3 N / cm or more.
If the 180 ° peel strength with respect to glass is 3 N / cm or more, an excellent cohesive force can be exhibited, so that adherends can be firmly bonded to each other. Therefore, image display constituent members to be described later can be adhered more firmly.
From this point of view, the pressure-sensitive adhesive sheet preferably has a 180 ° peel strength of 3 N / cm or more when irradiated with light as described above, more preferably 5 N / cm or more, and more preferably 10 N / cm or more. Is more preferable.

(How to use this adhesive sheet)
This pressure-sensitive adhesive sheet can be used alone as it is. Moreover, it is also possible to use it by laminating with other members.

<This adhesive sheet laminate>
If this adhesive sheet laminated body is a laminated body which includes this adhesive sheet in a layer structure, the structure is arbitrary. For example, a pressure-sensitive adhesive sheet laminate can be formed by laminating a release film on one side or both sides of the pressure-sensitive adhesive sheet.

As the release film, any currently known film can be arbitrarily used.
The thickness of the release film is not particularly limited. Among them, for example, from the viewpoint of workability and handling properties, it is preferably 25 μm to 500 μm, more preferably 38 μm or more and 250 μm or less, and particularly preferably 50 μm or more or 200 μm or less.

<Hardened product>
When the photocurable composition is cured by irradiation with light (referred to as “photocuring”), the half width X3 (nm ⁻¹ ) of the one-dimensional scattering profile in the small-angle X-ray scattering measurement is 0. A cured product (referred to as “main cured product”) characterized in that 05 <X3 <0.25 can be obtained.
Here, the cured product means a product obtained by irradiating the photocurable composition with light and cured, and its form is arbitrary. Therefore, even if it is a sheet form, it does not need to be a sheet form.

In the present cured product, when the half-value width X3 (nm ⁻¹ ) of the one-dimensional scattering profile in the small-angle X-ray scattering measurement is 0.05 <X3 <0.25, a highly cured product with high cohesive force can be obtained. Obtainable.

From this viewpoint, in the present cured product, the half-value width X3 (nm ⁻¹ ) of the one-dimensional scattering profile in the small-angle X-ray scattering measurement is 0.05 <X3 <0 from the same viewpoint as in the present photocurable composition. .25, preferably 0.06 <X3 or X3 <0.24, especially 0.08 <X3 or X3 <0.22, and more preferably 0.10 <X3 or X3 <0.20. Even more preferably.

  From the above, the half width X3 is any of 0.05 <X3 <0.25, 0.05 <X3 <0.24, 0.05 <X3 <0.22 or 0.05 <X3 <0.20. Preferably, 0.06 <X3 <0.25, 0.06 <X3 <0.24, 0.06 <X3 <0.22 or 0.06 <X3 <0.20. It is more preferable that any one of 0.08 <X3 <0.25, 0.08 <X3 <0.24, 0.08 <X3 <0.22 or 0.08 <X3 <0.20 among them. It is more preferable that 0.10 <X3 <0.25, 0.10 <X3 <0.24, 0.10 <X3 <0.22 or 0.10 <X3 <0.20 among them. Most preferably.

The main means for adjusting the full width at half maximum X3 in the cured product is the same as the means for adjusting the full width at half maximum X1 (nm ⁻¹ ). For example, the structure, composition, molecular weight, etc. of the (meth) acrylic copolymer (A) as the base polymer are adjusted, and the type and amount of the crosslinking agent (B) and crosslinking initiator (C) are adjusted or selected. The means to do can be mentioned. However, it is not limited to these means.

  Furthermore, in this hardened | cured material, in order to adjust the said half value width X3 to a preferable range, as mentioned in detail, (1) The copolymer component (main component) which becomes the main of a (meth) acrylic-type copolymer as mentioned above. It is preferable to use a (meth) acrylic monomer or vinyl monomer having 5 or more carbon atoms, especially 8 or more, of which 9 or more, and particularly 10 or more. Specifically, it is preferable to select from the examples of monomers contained in the trunk component of the acrylic copolymer (A1) described above.

  (2a) It is preferable to use a hydrophilic component as the copolymerizable component (trunk component) other than the (meth) acrylic monomer or vinyl monomer. Specifically, it is preferable to select from the examples of hydrophilic monomers contained in the trunk component of the acrylic copolymer (A1) described later. In addition, it is more preferable that (2b) the hydrophilic component is contained in a mass ratio of 0.1 to 20 with respect to the copolymer component (trunk component) 100 to increase the hydrophilicity of the trunk component.

  Furthermore, as a branch component of (3) (meth) acrylic copolymer (A), a (meth) acrylic monomer or vinyl monomer component having 4 or less carbon atoms is in a mass ratio of 1 to 100 with respect to trunk component 100. It is preferable to adjust the microphase separation state formed by the trunk component phase and the branch component phase. In addition, as a branching component of (3b) (meth) acrylic copolymer (A), a (meth) acrylic monomer or vinyl monomer component having a cyclic structure, It is preferable to adjust the microphase separation state formed by the trunk component phase and the branch component phase.

  Furthermore, it is preferable to use a hydroxyl group-containing compound having high compatibility with the hydrophilic component as (4a) the crosslinking agent (B). Specifically, it is preferable to select from the examples of the crosslinking agent (B) described above. In addition, it is more preferable that (4b) 0.05 to 30 parts by mass of the crosslinking agent (B) is added to 100 parts by mass of the (meth) acrylic copolymer to appropriately adjust the polarity of the trunk component. .

  As mentioned above, the phase-separated structure which a trunk component and a branch component comprise can be adjusted by selecting said (1)-(4) each independently suitably. Among them, among the methods (1) to (4b), (1) and (2a) and / or (2b) are combined, or (1) and (3a) and / or (3b) are combined. It is preferable to combine (1) with (3a) and / or (3b) with (4a) and / or (4b), and adopt all methods (1) to (4b). Is most preferred. However, it is not limited to this method.

  As described above, since an optimal phase separation state may be formed by using the graft polymer and optimizing the compatibility balance between the branch component and the trunk component, other than the above, for example, By using a hydrophobic component as the main copolymerizable component (trunk component) of the polymer (A) and using a hydrophilic component as the branch component of the copolymer (B), the half width X3 is It can also be controlled.

<Laminated body for configuring the present image display device>
Two component members for an image display device are laminated through the photocurable composition, the pressure-sensitive adhesive sheet, or the cured product, and the laminate for the configuration of the image display device (“the laminate for the configuration of the image display device”). Can be configured).

  In this case, examples of the two constituent members for the image display device include any one of a group consisting of a touch sensor, an image display panel, a surface protection panel, and a polarizing film, or a combination of two or more types.

Specific examples of the laminate for constituting the image display device include, for example, a release sheet / the present photocurable composition or the present adhesive sheet or the present cured product / touch panel, a release sheet / the present photocurable composition, or the above. The present adhesive sheet or the present cured product / protective panel, the release sheet / the present photocurable composition or the present adhesive sheet or the present cured product / image display panel, the image display panel / the present photocurable composition or the present book. Adhesive sheet or the main cured product / touch panel, image display panel / main photocurable composition or the main adhesive sheet or main cured product / protective panel, image display panel / main photocurable composition, or the main adhesive sheet or The present cured product / touch panel / the present photocurable composition or the present adhesive sheet or the present cured product / protective panel, the polarizing film / the present photocurable composition or the present adhesive sheet or the present book. Structures such as a compound / touch panel, a polarizing film / the present photocurable composition or the present adhesive sheet or the present cured product / touch panel / the present photocurable composition or the present adhesive sheet or the present cured product / protective panel be able to. However, it is not limited to these lamination examples.
The touch panel includes a structure in which a touch panel function is included in a protective panel and a structure in which a touch panel function is included in an image display panel.

<This image display device>
An image display device (referred to as “the present image display device”) can be configured using the laminate for constituting the image display device as described above.
As this image display apparatus, image display apparatuses, such as a liquid crystal display, an organic EL display, an inorganic EL display, electronic paper, a plasma display, and a micro electro mechanical system (MEMS) display, can be comprised, for example.

<Explanation of words>
In the present specification, when expressed as “X to Y” (X and Y are arbitrary numbers), unless otherwise specified, “X is preferably greater than X” or “preferably Y”. It also includes the meaning of “smaller”.
Further, when expressed as “X or more” or “X ≦” (X is an arbitrary number), the intention of “preferably larger than X” is also included.
Further, when expressed as “Y or less” or “Y ≧” (Y is an arbitrary number), the intention of “preferably less than Y” is also included.

  In general, the boundary between the sheet and the film is not clear, and it is not necessary to distinguish the two in terms of the wording in the present invention. Therefore, in the present invention, even when the term “film” is used, the term “sheet” is included. Even when referring to it, “film” is included.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples.

[Example 1]
As the (meth) acrylic copolymer (A), an acrylic polymer obtained by random copolymerization of 15 parts by mass of a polymethyl methacrylate macromonomer having a number average molecular weight of 2500, 81 parts by mass of butyl acrylate, and 4 parts by mass of acrylic acid. 50 g of propoxylated pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester ATM-4PL) (B-1) as a crosslinking agent (B) per 1 kg of the copolymer (A-1, mass average molecular weight: 200,000) Then, 15 g of Ezacure TZT (manufactured by IGM) (C-1) was added as a photoinitiator (C) and mixed uniformly to obtain a photocurable composition 1.

  Next, the said photocurable composition 1 was shape | molded in the sheet form so that it might become 150 micrometers in thickness on the polyethylene terephthalate film (the Mitsubishi resin company make, Diafoil MRV, thickness 100 micrometers) by which the surface was peel-processed. Thereafter, a polyethylene terephthalate film (Made by Mitsubishi Plastics, Diafoil MRQ, thickness 75 μm) whose surface was peeled was coated to prepare an adhesive sheet laminate 1.

[Example 2]
As the (meth) acrylic copolymer (A), 15 parts by mass of a polymethyl methacrylate macromonomer (number average molecular weight 3000) whose terminal functional group is a methacryloyl group, 81 parts by mass of butyl acrylate, and 4 parts by mass of acrylic acid Propoxylated pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester) as a crosslinking agent (B) for 1 kg of an acrylic copolymer (A-2, mass average molecular weight: 150,000) obtained by random copolymerization of parts The photocurable composition 2 was obtained by adding 110 g of ATM-4PL) (B-1) and 15 g of Ezacure TZT (manufactured by IGM) (C-1) as the photoinitiator (C) and mixing them uniformly.
The photocurable composition 2 produced an adhesive sheet laminate 2 in the same manner as in Example 1.

[Example 3]
As the (meth) acrylic copolymer (A), 15 parts by mass of a polymethyl methacrylate macromonomer (number average molecular weight 6700) whose terminal functional group is a methacryloyl group, 81 parts by mass of butyl acrylate, and 4 parts by mass of acrylic acid A nonanediol diacrylate (manufactured by Osaka Organic Industry Co., Ltd., Viscoat 260) is used as a crosslinking agent (B) for 1 kg of an acrylic copolymer (A-3, mass average molecular weight: 46,000) obtained by random copolymerization of parts. ) (B-2) 5 g, Ezacure TZT (manufactured by IGM) (C-1) 15 g was added as a photoinitiator (C), and mixed uniformly to obtain a photocurable composition 3.
The photocurable composition 3 produced an adhesive sheet laminate 3 in the same manner as in Example 1.

[Example 4]
As the (meth) acrylic copolymer (A), 30 parts by mass of a polymethyl methacrylate macromonomer (number average molecular weight 2500) whose terminal functional group is a methacryloyl group, 66 parts by mass of butyl acrylate, and 4 parts by mass of acrylic acid 2-isocyanaethyl methacrylate (produced by Showa Denko KK, Karenz MOI) as a crosslinking agent (B) for 1 kg of an acrylic copolymer (A-4, mass average molecular weight: 110,000) formed by random copolymerization 27 g of (B-3) was mixed. It heated at 80 degreeC for 4 hours, and the carboxyl group of the (meth) acrylic-type copolymer (A-4) and the isocyanate group of the crosslinking agent (B-3) were made to react. Thereafter, 15 g of Ezacure TZT (manufactured by IGM) (C-1) as a photoinitiator (C) and 100 g of hydroxybutyl acrylate were added and mixed uniformly to obtain a photocurable composition 4.
For the photocurable composition 4, a pressure-sensitive adhesive sheet laminate 4 was produced in the same manner as in Example 1.

[Example 5]
As the (meth) acrylic copolymer (A), 1 kg of the acrylic copolymer (A-2, mass average molecular weight: 150,000) used in Example 2, and 2-isocyanate as the crosslinking agent (B) 36 g of naethyl methacrylate (Showen Denko, Karenz MOI) (B-3) was mixed. It heated at 80 degreeC for 4 hours, and the carboxyl group of the (meth) acrylic-type copolymer (A-4) and the isocyanate group of the crosslinking agent (B-3) were made to react. Thereafter, 15 g of Ezacure KTO46 (manufactured by IGM) (C-2) was added as a photoinitiator (C) and mixed uniformly to obtain a photocurable composition 5.
The photocurable composition 5 produced an adhesive sheet laminate 5 in the same manner as in Example 1.

[Example 6]
11 parts by weight of a polymethyl methacrylate macromonomer (number average molecular weight 2500) whose terminal functional group having a number average molecular weight of 2500 is a methacryloyl group as the (meth) acrylic copolymer (A), 86 parts by weight of 2-ethylhexyl acrylate, And 1 kg of an acrylic copolymer (A-5, mass average molecular weight: 74,000) obtained by random copolymerization of 3 parts by mass of acrylic acid, propoxylated pentaerythritol triacrylate (new) as a crosslinking agent (B) Nakamura Chemical Co., Ltd., NK Ester ATM-4PL) (B-1) 90 g, Ezacure TZT (IGM Co., Ltd.) (C-1) 15 g is added as a photoinitiator (C), uniformly mixed, and photocurable. Composition 6 was obtained.
The photocurable composition 6 produced an adhesive sheet laminate 6 in the same manner as in Example 1.

[Example 7]
As the (meth) acrylic copolymer (A), 13.5 parts by mass of a macromonomer (number average molecular weight 3000) having a terminal functional group of methacryloyl group consisting of isobornyl methacrylate: methyl methacrylate = 1: 1, Acrylic graft copolymer (A-6, mass average molecular weight: 160,000) obtained by random copolymerization of 43.7 parts by mass of lauryl acrylate, 40 parts by mass of 2-ethylhexyl acrylate, and 2.8 parts by mass of acrylamide. For 1 kg, 50 g of propoxylated pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester ATM-4PL) (B-1) as a crosslinking agent (B), and methylbenzoyl formate (Lambson) as a photoinitiator (C) Manufactured, Speed Cure MBF) (C-3) 15g, and mixed uniformly, To obtain a sexual composition 7.
The photocurable composition 7 produced the pressure-sensitive adhesive sheet laminate 7 in the same manner as in Example 1.

[Example 8]
As the (meth) acrylic copolymer (A), 30 parts by mass of macromonomer (number average molecular weight 3000) having a terminal functional group of methacryloyl group consisting of isobornyl methacrylate: methyl methacrylate = 1: 1, lauryl acrylate 33 parts by mass, 34 parts by mass of 2-ethylhexyl acrylate, and 1 kg of an acrylic graft copolymer (A-7, mass average molecular weight: 79,000) obtained by random copolymerization of 3 parts by mass of acrylamide, 200 g of tricyclodecane dimethanol dimethacrylate (manufactured by Shin-Nakamura Chemical Co., DCP) (B-4) as a crosslinking agent (B) and 15 g of Ezacure TZT (manufactured by IGM) (C-1) as a photoinitiator (C) The mixture was added and mixed uniformly to obtain a photocurable composition 8.
The photocurable composition 8 produced an adhesive sheet laminate 8 in the same manner as in Example 1.

[Example 9]
As the (meth) acrylic copolymer (A), 13.5 parts by mass of a macromonomer (number average molecular weight 8800) having a terminal functional group of methacryloyl group consisting of isobornyl methacrylate: methyl methacrylate = 1: 1, Acrylic graft copolymer (A-8, mass average molecular weight: 110,000) obtained by random copolymerization of 43.7 parts by mass of lauryl acrylate, 40 parts by mass of 2-ethylhexyl acrylate, and 2.8 parts by mass of acrylamide. For 1 kg, 90 g of propoxylated pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester ATM-4PL) (B-1) as a crosslinking agent (B), and Ezacure TZT (manufactured by IGM) as a photoinitiator (C) (C-1) 15 g was added and mixed uniformly to obtain a photocurable composition 9.
The photocurable composition 9 produced an adhesive sheet laminate 9 in the same manner as in Example 1.

[Comparative Example 1]
As the (meth) acrylic copolymer (A), a MMA-BA-MMA triblock copolymer (Kuraray Co., Ltd., Clarity LA2140e) (A-9, mass average molecular weight: 7. 40 kg) 1 kg, propoxylated pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK Ester ATM-4PL) (B-1) 110 g, and photoinitiator (C) Ezacure TZT (IGM) (C-1) (C-1) 15 g was added and mixed uniformly to obtain a photocurable composition 10.
The photocurable composition 10 produced an adhesive sheet laminate 10 in the same manner as in Example 1.

[Comparative Example 2]
As the (meth) acrylic copolymer (A), an acrylic copolymer (A-10, mass average molecular weight: 24 parts by mass of 2-ethylhexyl acrylate, 74 parts by mass of butyl acrylate, and 2 parts by mass of acrylic acid: 500,000) 1 kg, nonanediol diacrylate (Biscoat 260) (B-2) (B-2) 5.5 g as a crosslinking agent (B), and ezacure TZT (C) as a photocrosslinking initiator (C) -1) 9.5 g (manufactured by IGM) was added and mixed uniformly to obtain a photocurable composition 11. The (meth) acrylic copolymer (A-10) is a copolymer that does not contain a macromonomer component.
The photocurable composition 11 produced an adhesive sheet laminate 11 in the same manner as in Example 1.

[Comparative Example 3]
As the (meth) acrylic copolymer (A), 13.5 parts by mass of a macromonomer (number average molecular weight 3000) having a terminal functional group of methacryloyl group consisting of isobornyl methacrylate: methyl methacrylate = 1: 1, An acrylic graft copolymer (A-11, mass average molecular weight: 4.9) obtained by random copolymerization of 43.7 parts by mass of lauryl acrylate, 40 parts by mass of 2-ethylhexyl acrylate, and 2.8 parts by mass of acrylamide. 1) 1 kg of propoxylated pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester ATM-4PL) (B-1) as a crosslinking agent (B), and Ezacure TZT (C-) as a photoinitiator (C) 1) 15 g (manufactured by IGM) was added and mixed uniformly to obtain a photocurable composition 12.
The photocurable composition 12 produced an adhesive sheet laminate 12 in the same manner as in Example 1.
In addition, since the said (meth) acrylic-type polymer (A-11) has low molecular weight and high fluidity | liquidity, the photocurable composition 12 became viscous liquid form at room temperature.

<Evaluation>
Next, the evaluation method about the photocurable composition obtained by the said Example and comparative example, an adhesive sheet, or an adhesive sheet laminated body is demonstrated.

[Small angle X-ray scattering]
Small-angle X-ray scattering measurement was performed at BL03XU (Frontier Soft Matter Development Industry-Academia Beamline) of SPring-8, a large synchrotron radiation facility.
About the adhesive sheet laminated body produced by the Example and the comparative example, ie, the photocurable composition before photocuring, the release film of both surfaces was peeled and the adhesive sheet was installed in the jig for samples.
The X-ray beam shape was adjusted to be 120 μm in length and 120 μm in width. The X-ray wavelength was 1 mm, and a CCD (Hamamatsu Photonics V7739P + ORCA R2) was used as the detector. The camera length was set to about 4 m, and correction was performed using a standard sample (collagen). The type, thickness, and exposure time of the attenuator (attenuation plate) were adjusted so that the detector was not damaged by strong X-rays, and the sample was irradiated with X-rays to obtain a two-dimensional scattered image of the sample.

The background was corrected from the two-dimensional scattered image of the sample obtained by the above procedure. Specifically, a background two-dimensional scattered image obtained by performing the same operation as in the above procedure without a sample is acquired, and the background is obtained from the sample two-dimensional scattered image using image processing software (Image-J). The two-dimensional scattered image was subtracted to obtain a two-dimensional scattered image for analysis. Ring-like scattering was confirmed in the two-dimensional scattered image for analysis. Next, the two-dimensional scattering image for analysis was converted into a one-dimensional scattering profile. Specifically, the two-dimensional scattered image for analysis is read by the X-ray data processing software (Fit2d) and integrated in the range of q = 0.04 to 0.4 over all azimuth angles. A one-dimensional scattering profile was obtained with the axis q [nm ⁻¹ ] and the vertical axis the scattering intensity.

From the obtained one-dimensional scattering profile, the half width X and peak position Y of the peak were obtained. In the one-dimensional scattering profile, a local minimum value is obtained near q = 0.1 and the scattering intensity increases toward the origin, and the scattering intensity increases toward the origin after passing through an inflection point near q = 0.1. In some cases, it became smaller. When the minimum value was taken near q = 0.1 and the scattering intensity increased toward the origin, the region larger than the minimum value q was set as the analysis target. When the scattering intensity decreases toward the origin after passing through the inflection point in the vicinity of q = 0.1, a region larger than q at the inflection point is set as the analysis target. Next, as the baseline correction, the minimum value of the scattering intensity in the analysis target region was obtained, and the baseline correction was performed by subtracting the minimum value over the entire region. The obtained one-dimensional scattering profile after correction was fitted with a Gaussian function and a Lorentz function, and the half width of the resultant composite function was set to X1 and the peak position was set to Y1. For the fitting, waveform separation software (Fityk) was used.
In addition, the inter-domain distance Z1 of the phase separation structure formed by the photocurable composition was calculated as Z1 = 2π / Y1. In addition, what was not detected from the obtained one-dimensional scattering profile was described as (ND) in the table.

About the adhesive sheet laminated body produced by the Example and the comparative example, it irradiated with light so that the integrated light quantity of wavelength 365nm might be set to 4000 mJ / cm < ² > from the one release film side using a high pressure mercury lamp, and photocurable composition The object was cured. About the photocurable composition after photocuring, that is, the cured product, in the same manner as the photocurable composition before photocuring described above, the peak half width (X2) and peak position of the one-dimensional scattering profile in the small-angle X-ray scattering measurement (Y2) was determined, and the interdomain distance (Z2) was calculated from the peak position (Y2).

[Retention force]
The pressure-sensitive adhesive sheet laminates produced in Examples and Comparative Examples were cut into 40 mm × 50 mm, the release film on one side was peeled off, and a polyethylene terephthalate film for backing (Diafoil S-100 made by Mitsubishi Plastics, thickness 38 μm) was handed. After backing with a roller, this was cut into a strip of 25 mm width × 100 mm length to obtain a test piece.
Next, the remaining release film was peeled off and attached to a SUS plate (120 mm × 50 mm × thickness 1.2 mm) with a hand roller so that the application area was 25 mm × 20 mm.
Then, after the test piece was cured for 15 minutes in an atmosphere of 40 ° C., a weight of 500 gf (4.9 N) was attached to the test piece in a vertical direction and left standing, and then the falling time (minute) of the weight was determined. It was measured. About what did not fall within 30 minutes, the length (mm) that the sticking position of SUS and a test piece shifted | deviated below, ie, the gap | deviation amount, was measured.
In the table, “<0.2 mm” means that the amount of deviation is less than 0.2 mm and there is almost no deviation.

[Glass adhesive strength]
<Measurement of adhesive strength before curing>
About the adhesive sheet laminated body produced by the Example and the comparative example, one release film was peeled off, and a polyethylene terephthalate film (Toyobo Co., Ltd .; brand name "Cosmo Shine A4300", thickness 100 micrometers) was used as a backing film with a hand roller. Roll-bonded. This was cut into a strip of 10 mm width × 100 mm length, and the remaining release film was peeled off, and the exposed adhesive surface was roll-bonded to soda lime glass using a hand roller. An autoclave treatment (70 ° C., gauge pressure 0.2 MPa, 20 minutes) was applied and finished and a glass adhesive strength measurement sample before photocuring was prepared. While pulling the backing film at an angle of 180 ° at a peeling speed of 60 mm / min, the adhesive sheet is peeled from the glass, the tensile strength is measured with a load cell, and the 180 ° peel strength (N / Cm) was measured.

<Measurement of adhesive strength after curing>
About the adhesive sheet laminated body produced by the Example and the comparative example, one release film was peeled off, and a polyethylene terephthalate film (Toyobo Co., Ltd .; brand name "Cosmo Shine A4300", thickness 100 micrometers) was used as a backing film with a hand roller. Roll-bonded. This was cut into a strip of 10 mm width × 100 mm length, and the remaining release film was peeled off, and the exposed adhesive surface was roll-bonded to soda lime glass using a hand roller. After autoclaving (70 ° C., gauge pressure 0.2 MPa, 20 minutes) and finishing and sticking, using a high-pressure mercury lamp from the backing film side, adhesive so that the integrated light quantity at a wavelength of 365 nm is 4000 mJ / cm ^2. The sheet was irradiated with light, and a glass adhesive strength measurement sample after photocuring was produced. While peeling the adhesive film from the glass while pulling the backing film at an angle of 180 ° at a peeling speed of 60 mm / min, the tensile strength is measured with a load cell, and the 180 ° peel strength (N / Cm) was measured.
In addition, “<0.5” in the table indicates a state where the peel strength is too small to be measured.

[Relative permittivity]
About the adhesive sheet laminated body produced by the Example and the comparative example, it irradiated with light so that the integrated light quantity of wavelength 365nm might be set to 4000 mJ / cm < ² > from the one release film side using a high pressure mercury lamp, and photocurable composition The object was cured. Thereafter, the release film was sequentially peeled off and attached to an electrode (manufactured by Keycom, DPT-009). Based on JIS K6911, the relative dielectric constant at 23 ° C. 50% RH and frequency 100 kHz was measured with an LCR meter (manufactured by Agilent Technologies, E4980A).
A case where the relative dielectric constant at a frequency of 100 kHz was 3.5 or more was evaluated as “× (poor)”, and a case where the relative dielectric constant was less than 3.5 was evaluated as “good”.

[Metal corrosion resistance]
Five reciprocal wires of indium oxide (ITO) having a thickness of 100 to 150 mm are formed on a glass substrate (60 mm × 45 mm) so as to reciprocate 10.5 with a line width of 70 μm, a line length of 46 mm, and a line interval of 30 μm. At the same time, 2 mm squares made of ITO were formed at both ends of the reciprocating line to form an ITO pattern (length: about 97 cm), and an ITO glass substrate for metal corrosion resistance evaluation was produced.
One release film of the pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples was peeled off, and a PET film (Toyobo Co., Ltd., Cosmo Shine A4100, 125 μm) was attached to the exposed surface with a hand roller. Next, after cutting out the pressure-sensitive adhesive sheet to 52 mm × 45 mm, the remaining release film is peeled off, and the pressure-sensitive adhesive sheet is handed to the ITO glass substrate for metal corrosion resistance evaluation so as to cover the five reciprocating wires of ITO. Sticking with a roller. After autoclaving (70 ° C., gauge pressure 0.2 MPa, 20 minutes) and finishing and sticking, from the PET film side, using a high-pressure mercury lamp, adhesive so that the integrated light quantity at a wavelength of 365 nm is 4000 mJ / cm ^2. The sheet was irradiated with light to prepare a metal corrosion resistance evaluation sample (ITO wiring with adhesive sheet).

The resistance value at room temperature was measured for each of the five ITO wirings in this metal corrosion resistance evaluation sample (ITO wiring with adhesive sheet), and the average value (Ω0) of the initial wiring resistance values was obtained.
The corrosion resistance reliability evaluation sample (ITO wiring with adhesive sheet) was stored in a 65 ° C. 90% RH environment for 800 hours. After storage, the resistance value of the ITO wiring in the metal corrosion resistance evaluation sample (ITO wiring with adhesive sheet) was measured in the same manner, and the average value (Ω) of the wiring resistance value after the environmental test was obtained.
Then, the rate of change (%) [((Ω / Ω0) -1) × 100] of the ITO resistance value, that is, the resistance value between line ends was calculated and indicated as “resistance value change” in the table.
A change in resistance value of less than 5% was judged as “◎ (very good)”, 5% or more but less than 10% as “◯ (good)”, and 10% or more as “x (poor)”.

[Shape stability]
About the adhesive sheet laminated body produced by the Example and the comparative example, the other release film (Mitsubishi resin company make, Diafoil MRV from the one release film (Made by Mitsubishi resin company, Diafoil MRQ, thickness 75 micrometers) side) The pressure-sensitive adhesive sheet was half-cut into a 30 mm × 30 mm square shape so as not to penetrate a thickness of 100 μm.
One of the cut release films (Mitsubishi Resin, Diafoil MRQ, thickness 75 μm) is peeled off, and the polyethylene terephthalate film (Mitsubishi Resin, Diafoil MRT, thickness) is peeled on the exposed adhesive surface. 50 μm). The release films on both sides were cut into 50 mm × 50 mm, and samples for shape stability evaluation before photocuring were prepared.
The sample for shape stability evaluation was cured for 300 hours in an environment of a temperature of 40 ° C. and a humidity of 90%, and the amount of protrusion of the adhesive material on the end face of the adhesive sheet after curing was observed. The amount of protrusion of the adhesive material was determined by measuring the protruding distance of the adhesive material at the center of each side of the cut adhesive sheet after curing, and taking the average distance of the four sides as the protruding amount (mm) of the adhesive material.

After curing, the pressure-sensitive adhesive sheet collapsed, and the sticking amount of the sticking material was 2 mm or more, “× (poor)”, and the sticking material sticking out was found to be 1 mm or more and less than 2 mm. ) "Was determined to be" very good "if it was less than 1 mm.
In the table, “<0.1 mm” means that the amount of protrusion of the adhesive material is less than 0.1 mm and there is almost no protrusion of the adhesive material, and “> 2.0 mm” indicates that the adhesive material does not protrude. It is more prominent and indicates a state where the amount of protrusion is larger than 2.0 mm.

[Step absorbency]
58 mm x 110 mm x 0.8 mm thick glass peripheral edge (long side 3 mm, short side 15 mm), printed with a thickness of 40-50 μm, with a central recess 52 mm x 80 mm printed glass plate with printed steps Prepared.
One release film of the pressure-sensitive adhesive sheet laminate produced in Examples and Comparative Examples was peeled off and roll-bonded to the entire surface of soda lime glass (54 mm × 82 mm × thickness 0.5 mm). The remaining release film is peeled off, and pressure bonding is performed using a vacuum press so that an adhesive sheet is applied to the frame-shaped printing step of the glass plate with printing steps (absolute pressure 5 kPa, temperature 70 ° C., pressing pressure 0.04 MPa). An evaluation sample was prepared.

  Regarding the level difference absorbability of the evaluation sample, after autoclaving for 30 minutes under the conditions of 60 ° C. and 0.3 MPa, the appearance of the bonded evaluation sample was confirmed, and bubbles were observed in the vicinity of the printing level difference. “× (poor)”, and those where no bubbles were observed were judged as “good”.

[Foam resistance]
A polarizing plate with an adhesive layer (manufactured by Sanlitz, VLC2-1518AGD2SF4, size 54 mm × 82 mm) is attached to a soda lime glass of 54 mm × 82 mm × thickness 0.5 mm with a hand roller, and autoclaved (25 ° C., gauge A polarizing plate substrate was prepared by applying a pressure of 0.2 MPa for 20 minutes.
The release film on one side of the pressure-sensitive adhesive sheet laminate produced in Examples and Comparative Examples was peeled off, and 54 mm × 82 mm × 0.5 mm thick soda lime glass was attached to the exposed surface with a hand roller. Next, the release film on which the pressure-sensitive adhesive sheet laminate remained was peeled off, and the polarizing plate surface of the polarizing plate substrate was attached to the exposed surface with a hand roll. After autoclaving (temperature 60 ° C., atmospheric pressure 0.4 MPa, 30 minutes) and finishing and sticking, using a high-pressure mercury lamp from the soda lime glass surface, the integrated light intensity at a wavelength of 365 nm is 4000 mJ / cm ^2. The sheet was irradiated with light to prepare a foam resistance reliability evaluation sample.

  The evaluation sample was cured under an environment of 95 ° C. for 100 hours, and “○ (good)” indicates that the appearance was not changed without foaming, and “× (poor)” indicates that foaming or peeling was observed. Judged.

The photocurable compositions prepared in the examples have both a suitable cohesive force and adhesiveness because the half-value width of the photocurable composition obtained by small-angle X-ray scattering measurement is within a predetermined range. It was also excellent in storage stability and bonding reliability.
As for the photocurable composition before and after photocuring, the half width of 0.08 or more resulted in particularly high holding power.
For the photocurable compositions 6 to 9 using a hydrophobic monomer having 5 or more carbon atoms as the main copolymer component of the (meth) acrylic copolymer (A), the relative dielectric constant at a frequency of 100 kHz is used. The rate was as low as 3.5 or less, and it was more suitably used for touch sensors.
Furthermore, about the photocurable compositions 7-9, as a copolymerization component of a (meth) acrylic-type copolymer (A), a highly acidic carboxyl group-containing monomer or acid anhydride group-containing monomer is not used, and hydrophilicity is obtained. Acrylamide is used as a sex ingredient. For this reason, the photocurable compositions 7 to 9 are particularly excellent in metal corrosion resistance and can be suitably used for adherends having corrosive properties such as metals and metal oxides.

On the other hand, the photocurable composition prepared in Comparative Example 1 has a half-value width X1 of the photocurable composition obtained by small-angle X-ray scattering measurement of less than 0.05 and is outside the scope of the present invention. Was too strong and poor in tackiness and poor in step absorbability.
In the photocurable composition produced in Comparative Example 2, no one-dimensional scattering profile was observed by small angle X-ray scattering measurement. For this reason, the photocurable composition has poor cohesive force, and has poor storage stability before photocuring and poor foaming reliability after bonding.
The photocurable composition produced in Comparative Example 3 uses a (meth) acrylic polymer containing a macromonomer as a structural unit, but becomes a viscous liquid at room temperature, and the photocurable composition is a small-angle X-ray. A one-dimensional scattering profile in the scattering measurement was not observed. For this reason, the photocurable composition has poor cohesive force, and is inferior in storage stability before photocuring and anti-foaming reliability after bonding.

Claims (15)

A photocurable composition comprising a (meth) acrylic copolymer (A) containing a macromonomer as a structural unit, a crosslinking agent (B), and a crosslinking initiator (C),
A photocurable composition, wherein a half-value width X1 (nm ⁻¹ ) of a one-dimensional scattering profile in small-angle X-ray scattering measurement is 0.05 <X1 <0.30. A half-value width X2 (nm ⁻¹ ) of a one-dimensional scattering profile in small-angle X-ray scattering measurement when irradiating light of 4000 mJ / m ² as an integrated light irradiation amount is 0.05 <X2 <0.25. The photocurable composition according to claim 1.   The (meth) acrylic copolymer (A) is obtained by polymerizing a monomer containing a macromonomer (a) and a vinyl monomer (b). Photocurable composition.   The number average molecular weight of a macromonomer (a) is 500-100,000, The photocurable composition of Claim 3 characterized by the above-mentioned.   At least one of the crosslinking agent (B) and the crosslinking initiator (C) is bonded to the (meth) acrylic copolymer (A), according to any one of claims 1 to 4. Photocurable composition.   The photocurable composition according to any one of claims 1 to 5, which has a property of exhibiting adhesiveness at 20 ° C and softening or fluidizing at 50 to 100 ° C.   The adhesive sheet which consists of a photocurable composition in any one of Claims 1-6. The adhesive sheet is attached to glass, and the 180 ° peel strength with respect to the glass when irradiated with 4000 mJ / m ² of accumulated light irradiation amount is 3 N / cm or more. Adhesive sheet.   The adhesive sheet laminated body provided with the structure formed by laminating | stacking the adhesive sheet of Claim 7 or 8, and a release film.   The laminated body for image display apparatuses provided with the structure formed by interposing the photocurable composition in any one of Claims 1-6 between the two structural members for image display apparatuses. It is a cured product obtained by photocuring a photocurable composition containing a (meth) acrylic copolymer (A) containing a macromonomer as a structural unit, a crosslinking agent (B), and a crosslinking initiator (C). And
Hardened | cured material characterized by the half value width X3 (nm < ^-1 >) of the one-dimensional scattering profile in a small angle X-ray-scattering measurement being 0.05 <X3 <0.25.   The cured product according to claim 11, wherein the (meth) acrylic copolymer (A) is obtained by polymerizing a monomer containing the macromonomer (a) and the vinyl monomer (b). .   The laminated body for image display apparatuses provided with the structure formed by interposing the hardened | cured material of Claim 11 or 12 between the two structural members for image display apparatuses.   The image display device constituting member is a laminate composed of a combination of any two or more of the group consisting of a touch sensor, an image display panel, a surface protection panel, a polarizing film, and a retardation film. Item 14. The laminate for an image display device according to Item 10 or 13. An image display device comprising the laminate for constituting an image display device according to claim 10, 13 or 14.