TWI822414B - Photocurable adhesive sheet laminated body, manufacturing method of photocurable adhesive sheet laminated body, and image display panel laminated body manufacturing method - Google Patents

Abstract

The present invention relates to an adhesive sheet for bonding resin members. As an adhesive sheet that has photocurability and can achieve both step absorption and foaming resistance reliability, a photocurable adhesive sheet is proposed, which features The reason is: It is a photo-curable adhesive sheet used to bond a resin member (X) with a light transmittance of 10% or less at a wavelength of 365 nm and a light transmittance of 60% or more at a wavelength of 405 nm. It includes An adhesive layer (Y) that has all of the following characteristics (1) to (3). (1) The gel fraction is in the range of 0 to 60%. (2) The light transmittance at the wavelength of 390 nm is less than 89%, and the light transmittance at the wavelength of 410 nm is more than 80%. (3) It has photohardening properties that can be hardened by irradiation with light of a wavelength of 405 nm.

Description

Photocurable adhesive sheet laminated body, manufacturing method of photocurable adhesive sheet laminated body, and image display panel laminated body manufacturing method

The present invention relates to a photocurable adhesive sheet used to bond a resin member with ultraviolet cutoff properties that does not transmit ultraviolet rays, and has the property of being cured by irradiation with light (called "photo-curable adhesive sheet"). Hardening").

In recent years, in order to improve the visibility of image display devices, the following operations have been performed: filling image display panels and configurations such as liquid crystal displays (LCDs), plasma displays (PDP), and electroluminescent displays (ELD) with adhesives The gap between the protective panel or touch panel components on the front side (viewing side) is used to suppress the reflection of incident light or emitted light from the display image at the air layer interface.

As a method of filling the gaps between components of an image display device with an adhesive, it is known to fill the gaps with a liquid adhesive resin composition containing an ultraviolet curable resin, and then irradiate ultraviolet rays to cure them. method (Patent Document 1).

Also known is a method of using an adhesive sheet to fill the gaps between the components of the image display device. For example, Patent Document 2 discloses a method in which an adhesive sheet that has been primarily cross-linked by ultraviolet rays is bonded to a component of an image display device, and then the adhesive sheet is subjected to ultraviolet rays through the component of the image display device. Irradiation causes secondary hardening.

In Patent Document 3, when a transparent double-sided adhesive sheet is bonded to an image display device component having a step portion on the bonding surface, it is possible to follow the step portion and fill every corner, and A novel transparent double-sided adhesive sheet that can relax the strain generated in the adhesive sheet and maintain foaming resistance in high-temperature or high-humidity environments without compromising handleability reveals the following B-stage A transparent double-sided adhesive sheet containing one or more (meth)acrylate (co)polymers, with a molar absorption coefficient of 10 or more at a wavelength of 365 nm and a molar absorption coefficient of 0.1 or less at a wavelength of 405 nm. Dynamic storage modulus (E') at 60°C determined by the stretching method for the ultraviolet polymerization initiator (A) and the visible light polymerization initiator (B) with a molar absorption coefficient of 10 or more at a wavelength of 405 nm. The value (E'/G') divided by the dynamic storage modulus (G') at 60°C calculated by the shear method is 10 or more. [Prior technical literature] [Patent Document]

[Patent Document 1] International Publication No. 2010/027041 [Patent Document 2] Japanese Patent No. 4971529 [Patent Document 3] Japanese Patent Application Publication No. 2014-152295

[Problem to be solved by the invention]

When two components of the image display device are bonded using a photocurable adhesive sheet as described above, the two components of the image display device can be bonded once through the adhesive sheet and then automatically The outer side of one of the image display device components is irradiated with ultraviolet rays, and the adhesive sheet is cured by the ultraviolet rays through the image display device component, thereby performing secondary adhesion. With this method, it is possible to fill in the unevenness of the adhered surface while performing secondary adhesion, and finally it can be cured by ultraviolet rays to further improve the bonding reliability, so it can take into account the components to be bonded (also known as " "Laying member") "step difference absorption" when the adhered surface has unevenness and "foaming resistance reliability" after lamination.

For example, in a vehicle-mounted image display device or the like, a resin front panel is used to prevent glass from scattering, and a conductive member or a resin member such as a polarizing plate may be disposed inside the front panel. In this case, it is necessary to prevent the front panel or the conductive member or polarizing plate and other resin members disposed inside the front panel from deteriorating due to exposure to ultraviolet rays, such as yellowing. Therefore, the following operation is performed: among the resin members on the side exposed to ultraviolet rays UV absorbers are formulated to have the ability to absorb ultraviolet rays. However, in this case, it is impossible to irradiate ultraviolet rays from the outside of the image display device component as described above, and the adhesive sheet is cured by ultraviolet rays through the image display device component. Therefore, when laminating a resin front panel, it is necessary to use a non-photocurable adhesive sheet that is sufficiently cured to have foaming resistance reliability but does not have photocurability. However, the non-photocurable adhesive sheet may not be satisfactory in terms of step absorption properties.

The present invention provides a resin member that can be bonded to a resin member having ultraviolet cutoff properties that does not transmit ultraviolet rays, and can take into account the step-difference absorbability when the adherend surface of the bonded member has unevenness and the reliable foaming resistance after bonding. A novel adhesive sheet. [Technical means to solve problems]

The present invention proposes a photocurable adhesive sheet, which is characterized in that it is used to bond a resin member with ultraviolet cutoff properties that does not transmit ultraviolet rays, that is, the light transmittance at a wavelength of 365 nm is 10% or less, and the wavelength Photo-curable adhesive sheet of resin component (X) with a light transmittance of 60% or more at 405 nm, It includes an adhesive layer (Y) having all of the following characteristics (1) to (3). (1) The gel fraction (gel fraction before light irradiation X1) is in the range of 0 to 60%. (2) The light transmittance at the wavelength of 390 nm is less than 89%, and the light transmittance at the wavelength of 410 nm is more than 80%. (3) It has photohardening properties that can be hardened by irradiation with light of a wavelength of 405 nm.

The present invention also proposes a photocurable adhesive sheet laminate, which includes the above photocurable adhesive sheet and a light transmittance of 10% or less at a wavelength of 365 nm, and a light transmittance of 60% or more at a wavelength of 405 nm. It is composed of laminated resin components (X). [Effects of the invention]

The photocurable adhesive sheet proposed by the present invention has a gel fraction of 0 to 60% before photocuring, so it can obtain step absorption properties such as filling in the unevenness of the adhesive surface. On the other hand, it has The light transmittance at a wavelength of 390 nm is 89% or less, and it has photohardening properties that can be cured by irradiating light with a wavelength of 405 nm. Therefore, the light transmittance at a wavelength of 365 nm of the resin member (X) to be bonded It is less than 10% and has a light transmittance of more than 60% at a wavelength of 405 nm. It can also be hardened by irradiating light with a wavelength of 405 nm, thereby improving cohesion and achieving foaming resistance reliability after lamination. . In addition, the light transmittance of the photocurable adhesive sheet proposed by the present invention at a wavelength of 410 nm is more than 80%. Therefore, the following effects can be obtained: a sufficiently low light transmittance required for bonding optical components requiring transparency can be achieved. Yellowness (YI).

The photocurable adhesive sheet laminated body proposed by the present invention can obtain step absorption properties as described above. On the other hand, the adhesive layer (Y) of the photocurable adhesive sheet has a layer from the resin member (X). When the resin member (X) is irradiated with light having a wavelength of 405 nm from the outside, the difference in gel fraction increases the photocurability by more than 10%. Therefore, by blocking the resin member (X) from the outside, ) can harden the adhesive layer (Y) by irradiating light with a wavelength of 405 nm, and can also improve the cohesion and achieve foaming resistance reliability after lamination.

Next, an example of an embodiment of the present invention will be described. However, the present invention is not limited to this embodiment.

＜＜This adhesive sheet＞＞ An adhesive sheet (referred to as "this adhesive sheet") according to one embodiment of the present invention is a photocurable adhesive sheet including an adhesive layer (Y) having specific characteristics.

This adhesive sheet is an adhesive sheet having photocurable property that is cured by irradiation with light. At this time, the adhesive sheet may be cured into a state that leaves room for photocuring (also called "temporarily cured"), or may be uncured and has photocurability (called "uncured"). ")By. If the adhesive sheet is temporarily hardened or unhardened, after the adhesive sheet is bonded to the adherend, the adhesive sheet can be photocured (also called "formal curing"). The result will be It can improve cohesion and improve adhesion.

Preferable forms of the present adhesive sheet that are temporarily hardened or unhardened as described above and have properties that allow it to be formally hardened, that is, photocurable properties that can be hardened by irradiation of light with a wavelength of 405 nm, include the following ( The adhesive sheet of the adhesive layer (Y) shown in 1) to (3).

(1) The adhesive layer (Y) is temporarily hardened until the gel fraction becomes 60% or less. By containing the following visible light initiator (c), the visible light initiator (c) can be formally hardened. layer. (2) The adhesive layer (Y) is temporarily hardened by the hydrogen-abstracting type visible light initiator (c-2) in the visible light initiator (c) below until the gel fraction becomes less than 60%. The visible light initiator (c-2) is formally hardened to form an adhesive layer. (3) The adhesive layer (Y) maintains the shape of the sheet in an uncured state and can be formally cured by containing the visible light initiator (c) below. .

As a method of forming the adhesive layer (Y) in the above (1), for example, the following method can be cited: a (meth)acrylate (co)polymer (co)polymer containing a visible light initiator (c) and having a functional group (i) a), a compound having a functional group (ii) that reacts with the functional group (i), other photopolymerizable compounds with carbon-carbon double bonds (especially multifunctional monomers) and other cross-linking agents (b) if necessary ), and optionally, the composition of the silane coupling agent (d) (an example of the present resin composition described later) is heated or cured to form an adhesive layer (Y). According to this method, the functional group (i) in the (meth)acrylate (co)polymer reacts with the functional group (ii) in the compound to form a chemical bond and harden (cross-link) to form an adhesive layer ( Y). By forming the adhesive layer (Y) as described above, the visible light initiator (c) can be actively present in the adhesive layer (Y).

Examples of combinations of the functional group (i) and the functional group (ii) include a carboxyl group and an epoxy group, a carboxyl group and an aziridinyl group, a hydroxyl group and an isocyanato group, an amine group and an isocyanato group, and a carboxyl group and an isocyanate group. Cyanate group, etc. Among them, a combination of a hydroxyl group and an isocyanate group, an amine group and an isocyanate group, or a carboxyl group and an isocyanate group is particularly preferred. More specifically, the case where the above-mentioned (meth)acrylate copolymer (a) has a hydroxyl group (the following hydroxyl-containing monomer is used) and the above-mentioned compound has an isocyanate group is a particularly preferred example.

Furthermore, the compound having the functional group (ii) may further have a radically polymerizable functional group such as a (meth)acrylyl group. This can form a (meth)acrylate (co)polymer that maintains the above-mentioned radically polymerizable functional groups, specifically a (meth)acrylate having the following active energy ray crosslinkable structural parts. Photohardenable (cross-linked) adhesive layer (Y) of the copolymer. More specifically, the above-mentioned (meth)acrylate (co)polymer (a) has a hydroxyl group (the following hydroxyl-containing monomer is used), and the above-mentioned compound has a (meth)acrylyl group (isocyanate 2-Acryloxyethyl acid, 2-methacryloxyethyl isocyanate, 1,1-(bisacryloxymethyl)ethyl isocyanate, etc.) are particularly preferred examples. As described above, by utilizing the crosslinking reaction between (meth)acrylate (co)polymers due to the radically polymerizable functional group, it is possible to efficiently and easily form the polymer without using the crosslinking agent (b). It has the advantages of improved cohesion after photohardening (cross-linking) and excellent reliability, so it is better.

Furthermore, the acrylate (co)polymer (a) which is preferable in aspects other than the above, or the preferable form of the above-mentioned cross-linking agent (b), the above-mentioned visible light initiator (c) and the silane coupling agent (d) etc., as described below.

As a method of forming the adhesive layer (Y) in the above (2), for example, a method of using the following hydrogen abstraction type visible light initiator (c-2) as the visible light initiator (c) can be cited. Even if a hydrogen-abstracting initiator is excited once, the unreacted ones in the initiator will return to the base state and can therefore be reused as a visible light initiator. As described above, by using a hydrogen abstraction type visible light initiator, the visible light curing (cross-linking) property of the visible light initiator can be maintained even after temporary curing by visible light irradiation. In addition, aspects other than the above and preferred forms of the visible light initiator (c-2) are as follows.

As a method of forming the adhesive layer (Y) in the above (3), for example, there is a method of using the following macromonomer as a monomer component constituting the (meth)acrylate copolymer (a). More specifically, a method using a graft copolymer having a macromonomer as a branch component is exemplified. By utilizing such a macromonomer, it is possible to maintain a state in which branch components attract each other and are physically cross-linked into a composition (an example of this resin composition described later) at room temperature. Therefore, an adhesive layer (Y) that can maintain the shape of the sheet in an unhardened (cross-linked) state and contains the visible light initiator (c) can be formed. In addition, aspects other than the above and preferred forms of the graft copolymer having a macromonomer as a branch component are as follows.

This adhesive sheet is preferably used to bond the resin member (X) described below.

The adhesive sheet may be a single layer composed of the above-mentioned adhesive layer (Y), or may be a multi-layer structure having two or more layers of the above-mentioned adhesive layer (Y). Moreover, in the case of multiple layers, it is sufficient if at least the outermost layer is the above-mentioned adhesive layer (Y), or all the adhesive layers may be the above-mentioned adhesive layer (Y).

＜Adhesive layer (Y)＞ It is preferable that the above-mentioned adhesive layer (Y) has all of the following characteristics (1) to (3). (1) The gel fraction in the normal state, that is, the state before light irradiation (called "gel fraction before light irradiation X1") is in the range of 0 to 60%. (2) The light transmittance at the wavelength of 390 nm is less than 89%, and the light transmittance at the wavelength of 410 nm is more than 80%. (3) It has photohardening properties that can be hardened by irradiation with light of a wavelength of 405 nm.

If the adhesive layer (Y) has hot-melt properties that can be softened and even flowed by heating, when there is a step difference such as unevenness on the adhered surface of the bonding member, the adhesive can be further filled into the step difference more easily. Each corner can further improve step absorption, so it is better. From this viewpoint, it is preferable that the adhesive layer (Y) is the adhesive layer (Y) of (3) mentioned above.

(gel fraction) It is preferable that the gel fraction (gel fraction before light irradiation X1) of the adhesive layer (Y) is in the range of 0 to 60%. If the gel fraction of the adhesive layer (Y) is 60% or less, it is preferable from the following point of view: there is a sufficient amount of uncrosslinked components (in a temporarily hardened state or uncrosslinked components) that have room for hardening by light irradiation. Hardened state), because of this it is soft, and when it is officially hardened, the "gel fraction after light irradiation X2 - gel fraction before light irradiation X1" can be set to 10% or more. From this point of view, the gel fraction of the adhesive layer (Y) is preferably in the range of 0 to 60%, more preferably 55% or less, and even more preferably 50% or less.

In order to adjust the gel fraction of the adhesive layer (Y) (gel fraction before light irradiation It is sufficient to remove or use polymerization inhibitors, antioxidants, etc., so that undesirable curing (cross-linking) reactions caused by heat, light, etc. do not proceed before formal curing; and, after curing by light irradiation, When performing temporary hardening, it is sufficient to make the cumulative amount of light irradiated for temporary hardening sufficiently small and to increase the amount of uncrosslinked components sufficiently. However, it is not limited to this method.

Furthermore, it is preferable that the adhesive layer (Y) has photo-curing properties that can be cured by irradiation of light with a wavelength of 405 nm. As the degree of the photo-curing properties, for example, it is preferred that the adhesive layer (Y) has photo-curing properties between the outside and the resin member (X). When the resin member (X) is irradiated with light having a wavelength of 405 nm, the difference in gel fraction increases by more than 10%, preferably at least 15%, more preferably at least 20%, and still more preferably at least 30%. , among which the photohardenability of more than 50% is particularly preferred. Furthermore, the so-called "irradiation of light with a wavelength of 405 nm" means irradiation of light with a photosensitivity that has a photosensitive peak of 405 nm as a wavelength and extends to a wavelength range of 320 to 470 nm as measured using an ultraviolet light meter. Light sensitivity.

Among them, it is preferable that the adhesive layer (Y) has photocurability such that the cumulative amount of light irradiated from the outside of the above-mentioned resin member (X) through the resin member (X) at a wavelength of 405 nm is 3000 (mJ/cm ² ), the difference between the gel fraction before light irradiation (gel fraction before light irradiation X1) and the gel fraction after light irradiation (called "gel fraction after light irradiation The gel fraction X2 after light irradiation - the gel fraction X1 before light irradiation) becomes 10% or more. Therefore, it is preferable to have ^the following photohardenability: for example, when the gel fraction The gel fraction of layer (Y) (referred to as "gel fraction X2 after light irradiation") becomes 50% or more. If the difference in gel fraction of the adhesive layer (Y) before and after light hardening is 10% or more, it is preferable because it will have high cohesive force even in severe high temperature and high humidity environments, and the foaming resistance reliability will be improved. Therefore, the difference in gel fraction of the adhesive layer (Y) before and after the light irradiation is preferably 10% or more, more preferably 15% or more, more preferably 20% or more, and still more preferably 30%. Above, preferably above 50%. In order to adjust the gel fraction difference of the adhesive layer (Y) before and after the above light irradiation to the above range, the absorption of the photoinitiator can be present at the wavelength of 405 nm. However, it is not limited to this method.

In addition, the so-called "accumulated light amount at a wavelength of 405 nm" is the total amount of irradiation energy received per unit area. It refers to the light irradiated by a high-pressure mercury lamp, etc., using an ultraviolet integrated light meter "UIT-250" (manufactured by Ushio Electric Co., Ltd.) and the photoreceiver "UVD-C405" (manufactured by Ushio Electric Co., Ltd.). It refers to the photosensitive characteristics of the photoreceptor (having a sensitivity of 405 nm) peak, the peripheral light sensitivity extends to the wavelength range of 320 to 470 nm) and the cumulative light amount corresponding to the wavelength region. More specifically, it refers to the accumulated light amount calculated according to the method described in the Examples.

(light transmittance) Preferably, the light transmittance of the adhesive layer (Y) at a wavelength of 390 nm is less than 89%, and the light transmittance at a wavelength of 410 nm is more than 80%. Regarding an adhesive formulation containing a light initiator that absorbs in the ultraviolet to visible light range around 400 nm, the greater the light absorption of the light initiator, the greater the light transmittance at a wavelength of 390 nm derived from this absorption. If the value is low, the photosensitivity becomes better and hardening becomes easier. On the other hand, if the light transmittance at a wavelength of 410 nm is not high above a certain level, the adhesive layer (Y) will be colored yellow, making it difficult to use it in an optical member.

As the above criteria, if the light transmittance at a wavelength of 390 nm is 89% or less, the adhesive layer (Y) can ensure sufficient visible light curability, so it is better; if the light transmittance at a wavelength of 410 nm is 80% or more , it can achieve a sufficiently low yellowness (YI) required for bonding optical components that require transparency, so it is better. Therefore, the above-mentioned light transmittance of the wavelength 390 nm of the adhesive layer (Y) is preferably 89% or less, and more preferably 88% or less. Furthermore, the light transmittance at a wavelength of 410 nm is preferably 80% or more, more preferably 85% or more, and still more preferably 90% or more. In order to set the light transmittance of the adhesive layer (Y) as described above, it is sufficient to use a initiator that absorbs visible light and has the following absorption peak characteristics: the periphery of the absorption peak reaches 390 nm. In contrast, The absorption peak at 410 nm becomes smaller. However, it is not limited to this method.

(Storage Modulus) The storage modulus (G') of the adhesive layer (Y) is preferably 0.9×10 ⁵ Pa or less at a temperature of 25°C and a frequency of 1 Hz. By having such viscoelastic properties, this adhesive sheet can obtain particularly excellent step absorption properties required to fill in uneven steps on the adhered surface. From this point of view, the storage modulus (G') of the adhesive layer (Y) is preferably 0.9×10 ⁵ Pa or less at a temperature of 25°C and a frequency of 1 Hz, and further preferably 0.8×10 ⁵ Pa or less.

In addition, the storage modulus (G') of the adhesive layer (Y) after irradiating the adhesive layer (Y) with a cumulative light amount of 3000 (mJ/cm ² ) at a wavelength of 405 nm is preferably 0.7× at a temperature of 120°C and a frequency of 1 Hz. 10 ⁴ Pa and above. If the storage modulus (G') of the adhesive layer (Y) after light hardening falls into the above range, it is preferable to subject the laminate of the adhesive layer (Y) and the resin member (X) to a high-temperature test or a high-temperature test. During wet tests, etc., foaming of the adhesive layer (Y) caused by outgassing components from the resin member (X) can be suppressed. From this point of view, the storage modulus (G') of the adhesive layer (Y) after light hardening is preferably 0.7×10 ⁴ Pa or more at a temperature of 120°C and a frequency of 1 Hz, and more preferably 1.0×10 ⁴ Pa or more, particularly preferably 2.0×10 ⁴ Pa or more.

Here, in an image display device having a touch panel function, etc., as a touch sensor arranged on the back side of the front panel/adhesive layer, a glass sensor or a film sensor is used depending on the module design. Devices, polarizing plate glass (surface-mounted type or in-line type with a sensor incorporated inside), etc. have different susceptibility to defects in environmental tests due to the structure of the sensor component. The result of the experimental study in the present invention is that when the adhesive layer (Y) is used in conjunction with the structure of the resin component (X)/adhesive layer (Y)/glass sensor, the storage of the adhesive layer (Y) The preferred range of the modulus (G') is as shown above. On the other hand, when the structure of the resin member (X)/adhesive layer (Y)/film sensor is used in conjunction with each other, the film feel Detectors are usually thin-walled below 100 μm and have low hardness. Since the reliability improvement effect of the silane coupling agent is lower than that of the glass material, it is easier to test in hot and humid environments than with glass sensors. Foaming occurs and a higher level of storage modulus (G') becomes necessary.

Therefore, from this point of view, when the adhesive layer (Y) is bonded with the structure of the resin member (X)/adhesive layer (Y)/film sensor, the photo-cured adhesive layer (Y) is The storage modulus (G'), that is, the storage modulus (G') of the adhesive layer (Y) when irradiating light with a cumulative light intensity of 3000 (mJ/cm ² ) at a wavelength of 405 nm, is preferably in the range of 2.0× 10 ⁴ Pa or more, more preferably 5.0 × 10 ⁴ Pa or more, particularly more preferably 8.0 × 10 ⁴ Pa or more.

(Composition of adhesive layer (Y)) The adhesive layer (Y) can be composed of a (meth)acrylate (co)polymer (a) and a visible light initiator (c), a cross-linking agent (b) if necessary, and a silane coupling agent if necessary. (d), formed from an adhesive composition (called "this resin composition") containing other materials if necessary.

[(Meth)acrylate (co)polymer (a)] Preferably, the above-mentioned (meth)acrylate (co)polymer (a) is photohardenable.

In addition, the so-called "(meth)acrylic acid group" means an acrylic acid group and a methacrylic acid group, the so-called "(meth)acrylyl group" means an acrylyl group and a methacrylic acid group, and the so-called "(meth)acrylyl group" "Acrylate" means acrylate and methacrylate respectively. The so-called "(co)polymer" includes polymers and copolymers. In addition, the so-called "sheet" conceptually includes sheets, films, and tapes.

Examples of the (meth)acrylate (co)polymer (a) include, in addition to homopolymers of alkyl (meth)acrylate, copolymers obtained by polymerizing monomer components copolymerizable therewith. .

More specifically, examples of the (meth)acrylate (co)polymer (a) include alkyl (meth)acrylate and a monomer component copolymerizable therewith, for example, any monomer selected from the group consisting of: A copolymer of monomer components of more than one monomer: (a) a monomer containing a carboxyl group (hereinafter also referred to as "copolymerizable monomer A"), (b) a monomer containing a hydroxyl group (hereinafter also referred to as "copolymerizable monomer A") Monomer B"), (c) an amine group-containing monomer (hereinafter also referred to as "copolymerizable monomer C"), (d) epoxy group-containing monomer (hereinafter also referred to as "copolymerizable monomer D" ”), (e) amide group-containing monomer (hereinafter also referred to as “copolymerizable monomer E”), (f) vinyl monomer (hereinafter also referred to as “copolymerizable monomer F”), (g ) (meth)acrylate monomer with a side chain having 1 to 3 carbon atoms (hereinafter also referred to as "copolymerizable monomer G") and (h) macromonomer (hereinafter also referred to as "copolymerizable monomer H") ”).

As the above-mentioned (meth)acrylic acid alkyl ester, a linear or branched (meth)acrylic acid alkyl ester having a side chain having 4 to 18 carbon atoms is preferred. Examples of linear or branched (meth)acrylic acid alkyl esters with a side chain carbon number of 4 to 18 include: (meth)n-butyl acrylate, (meth)isobutyl acrylate, (meth)acrylate Second butyl acrylate, third butyl (meth)acrylate, amyl (meth)acrylate, isopentyl (meth)acrylate, neopentyl (meth)acrylate, hexyl (meth)acrylate Ester, cyclohexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, ( Nonyl methacrylate, isononyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, (meth) Undecyl acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, myristyl (meth)acrylate, cetyl (meth)acrylate, (meth) Stearyl acrylate, isostearyl (meth)acrylate, isostearyl (meth)acrylate, 3,5,5-trimethylcyclohexane (meth)acrylate, di(meth)acrylate Dicyclopentyl ester, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, etc. These may be used alone or in combination of two or more. Among the above, the linear or branched (meth)acrylic acid alkyl ester with a carbon number of 4 to 18 is particularly preferred including butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylate Any one or more of lauryl methacrylate and isopropyl (meth)acrylate.

Examples of the copolymerizable monomer A include: (meth)acrylic acid, 2-(meth)acryloxyethylhexahydrophthalic acid, and 2-(meth)acryloxypropylhexahydrophthalic acid. Hydrophthalic acid, 2-(meth)acryloxyethyl phthalic acid, 2-(meth)acryloxypropyl phthalic acid, 2-(meth)acryloxyethyl phthalic acid Ethyl maleic acid, 2-(meth)acryloxypropyl maleic acid, 2-(meth)acryloxyethyl succinic acid, 2-(meth)acryloxypropyl succinic acid acid, crotonic acid, fumaric acid, maleic acid, itaconic acid. These may be one type or a combination of two or more types.

Examples of the copolymerizable monomer B include: (meth)acrylic acid 2-hydroxyethyl, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid 3-hydroxypropyl, (meth)acrylic acid (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxybutyl ester. These may be one type or a combination of two or more types.

Examples of the copolymerizable monomer C include: (meth)acrylic acid aminomethyl ester, (meth)acrylic acid aminoethyl ester, (meth)acrylic acid aminopropyl ester, (meth)acrylic acid aminoisopropyl Propyl ester and other (meth)aminoalkyl acrylates, (meth)acrylic acid N-alkylaminoalkyl ester, (meth)acrylic acid N,N-dimethylaminoethyl ester, (meth)acrylic acid N,N-dialkylaminoalkyl (meth)acrylate such as N,N-dimethylaminopropyl ester. These may be one type or a combination of two or more types.

Examples of the copolymerizable monomer D include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and (methyl)acrylate. ) 4-hydroxybutyl acrylate glycidyl ether. These may be one type or a combination of two or more types.

Examples of the copolymerizable monomer E include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, and N-hydroxymethyl (meth)acrylamide, N-hydroxymethylpropane (meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide Amide, diacetone (meth)acrylamide, maleamide, maleimide. These may be one type or a combination of two or more types.

Examples of the copolymerizable monomer F include compounds having a vinyl group in the molecule. Examples of such compounds include (meth)acrylic acid alkyl esters whose alkyl group has 1 to 12 carbon atoms, and functional monomers having functional groups such as hydroxyl group, amide group, and alkoxyalkyl group in the molecule. polymers, as well as polyalkylene glycol di(meth)acrylates, vinyl ester monomers such as vinyl acetate, vinyl propionate and vinyl laurate, as well as styrene, chlorostyrene, chloromethyl Aromatic vinyl monomers such as styrene, α-methylstyrene and other substituted styrenes. These may be one type or a combination of two or more types. Furthermore, among the above, it is preferable to select the copolymerizable monomer F other than the alkyl (meth)acrylate and the alkyl (meth)acrylate.

Examples of the copolymerizable monomer G include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, and the like. These may be one type or a combination of two or more types. Furthermore, among the above, it is preferable to select the copolymerizable monomer G other than the alkyl (meth)acrylate and the alkyl (meth)acrylate.

As the macromonomer system of the above-mentioned copolymerizable monomer H, a polymer monomer having a terminal functional group and a high molecular weight skeleton component is preferably a side chain of A monomer with a carbon number of 20 or more.

By using the copolymerizable monomer H, the macromonomer can be introduced as a branch component of the graft copolymer, turning the (meth)acrylate copolymer into a graft copolymer. For example, a (meth)acrylate copolymer (a-1) containing a graft copolymer having a macromonomer as a branch component can be produced. Therefore, the characteristics of the main chain and side chains of the graft copolymer can be changed by the selection or blending ratio of the copolymerizable monomer H and its other monomers.

Preferably, the skeleton component of the macromonomer includes an acrylate polymer or a vinyl polymer. Examples include linear or branched (meth)acrylic acid alkyl esters having 4 to 18 carbon atoms in the side chain, the above-mentioned copolymerizable monomer A, the above-mentioned copolymerizable monomer B, the above-mentioned copolymerizable monomer G, etc. Those exemplified in can be used individually or in combination of two or more types.

Among them, it is preferable that the dry component of the (meth)acrylate copolymer (a-1) contains hydrophobic (meth)acrylate and hydrophilic (meth)acrylate as structural units.

As the above-mentioned hydrophobic (meth)acrylate, an alkyl ester having no polar group (excluding methyl acrylate) is preferred. Examples thereof include n-butyl (meth)acrylate and (meth)acrylic acid. Isobutyl ester, 2nd butyl (meth)acrylate, 3rd butyl (meth)acrylate, amyl (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, tert-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, (Methyl) Isoacrylate, cyclohexyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, methyl methacrylate. Examples of the hydrophobic vinyl monomer include vinyl acetate, styrene, tert-butylstyrene, α-methylstyrene, vinyltoluene, and alkylvinyl monomers.

On the other hand, the hydrophilic (meth)acrylate monomer is preferably methacrylate or an ester having a polar group, and examples thereof include methyl acrylate, (meth)acrylic acid, and (meth)acrylic acid. Tetrahydrofurfuryl ester, or (meth)acrylate containing hydroxyl groups such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, glyceryl (meth)acrylate, etc. , or (meth)acrylic acid, 2-(meth)acryloxyethylhexahydrophthalic acid, 2-(meth)acryloxypropylhexahydrophthalic acid, 2-(meth)acryloxyethylhexahydrophthalic acid methyl)acryloxyethyl phthalic acid, 2-(meth)acryloxyethyl phthalic acid, 2-(meth)acryloxyethyl maleic acid, 2-(meth)acryloxyethyl maleic acid 2-(meth)acryloxypropylmaleic acid, 2-(meth)acryloxypropylsuccinic acid, 2-(meth)acryloxypropylsuccinic acid, crotonic acid, fumaric acid, Maleic acid, itaconic acid, maleic acid monomethyl ester, itonic acid monomethyl ester and other monomers containing carboxyl groups, maleic anhydride, itonic acid anhydride and other monomers containing acid anhydride groups, (meth)acrylic acid glycidyl Monomers containing epoxy groups such as ester, α-ethyl glycidyl acrylate, 3,4-epoxybutyl (meth)acrylate, etc., alkoxy groups such as methoxy polyethylene glycol (meth)acrylate Polyalkylene glycol (meth)acrylate, N,N-dimethylacrylamide, hydroxyethylacrylamide, etc.

The above-mentioned macromonomer as the above-mentioned copolymerizable monomer H is preferably one having a functional group such as a radical polymerizable group, a hydroxyl group, an isocyanate group, an epoxy group, a carboxyl group, an amine group, a amide group or a thiol group. . As the above-mentioned macromonomer, one having a radical polymerizable group copolymerizable with other monomers is preferred. The radically polymerizable group may contain one or two or more radically polymerizable groups, and one is particularly preferred. When the above-mentioned macromonomer has a functional group, the functional group may also contain one or more than two, and one functional group is particularly preferred. Furthermore, either a radically polymerizable group or a functional group may be contained, or both may be contained. When it contains both a radical polymerizable group and a functional group, a functional group other than a functional group added to a polymer unit containing other monomers or a radical polymerizable group copolymerized with other monomers The number of radicals or radical polymerizable groups may be two or more.

Examples of the terminal functional group of the macromonomer include, in addition to radical polymerizing groups such as methacryloyl group, acrylyl group, and vinyl group, hydroxyl group, isocyanate group, epoxy group, carboxyl group, and amine group. group, amide group, thiol group and other functional groups. Among them, those having radically polymerizable groups copolymerizable with other monomers are preferred. The radically polymerizable group may contain one or two or more radically polymerizable groups, and one is particularly preferred. When the macromonomer has a functional group, the functional group may also contain one or more than two, and one functional group is particularly preferred. Furthermore, either a radically polymerizable group or a functional group may be contained, or both may be contained. When it contains both a radical polymerizable group and a functional group, a functional group other than a functional group added to a polymer unit containing other monomers or a radical polymerizable group copolymerized with other monomers The number of radicals or radical polymerizable groups may be two or more.

The number average molecular weight of the macromonomer is preferably 500 to 20,000, more preferably 800 or more or 8,000 or less, and still more preferably 1,000 or more or 7,000 or less.

It is preferable that the glass transition temperature (Tg) of the above-mentioned macromonomer is higher than the glass transition temperature of the copolymer component constituting the above-mentioned (meth)acrylate (co)polymer (a-1). Specifically, the glass transition temperature (Tg) of the macromonomer affects the heating melting temperature (hot melt temperature) of the adhesive sheet, so it is preferably 30°C to 120°C, and more preferably above 40°C or 110°C. below, and among them, 50°C or more or 100°C or less is more preferred.

If the macromonomer has such a glass transition temperature (Tg), excellent processability and storage stability can be maintained by adjusting the molecular weight, and it can be adjusted so that thermal melting occurs near 50°C to 80°C. The so-called glass transition temperature of the macromonomer refers to the glass transition temperature of the macromonomer itself, and can be measured by a differential scanning calorimeter (DSC).

In addition, in order to maintain the state in which branch components are attracted to each other and physically cross-linked to form an adhesive composition at room temperature, and to obtain fluidity by dissolving the above-mentioned physical cross-links by heating to an appropriate temperature, it is preferable that Adjust the molecular weight or content of macromonomer.

From this point of view, the macromonomer is preferably contained in the (meth)acrylate copolymer (a) at a ratio of 5% to 30% by mass, and more preferably 6% by mass or more or 25% by mass or less. The macromonomer is contained in a ratio of 8% by mass or more or 20% by mass or less. Furthermore, the number average molecular weight of the macromonomer is preferably 500 to 100,000, more preferably less than 8,000, more preferably 800 or more or less than 7,500, and still more preferably 1,000 or more or less than 7,000.

It is preferable that the (meth)acrylate (co)polymer (a) has an active energy ray cross-linkable structural part. The above-mentioned active energy ray crosslinkable structure can be formed with a part of the (meth)acrylate copolymer (a) or a (meth)acrylate copolymer in the presence of a visible light initiator (c) described below. Hardening components other than (a) react to form structural parts of a cross-linked structure.

Examples of the above-mentioned active energy ray cross-linkable structural parts include structures having radically polymerizable functional groups, such as (meth)acrylyl groups, vinyl groups, and other functional groups having unsaturated double bonds. radical polymerizable functional groups with carbon-carbon double bonds. Since the polymer chain of the above (meth)acrylate (co)polymer (a) has unsaturated double bonds, the polymer chains can be directly polymerized with each other even if it does not contain a cross-linking agent. The storage module (G') is increased to a higher level. Furthermore, when irradiating active energy rays, any light source containing light with a wavelength of 405 nm can be used. Considering the curing speed, availability of irradiation equipment, price, etc., visible light LED light sources, high-pressure mercury lamps, etc. can be used.

In order to introduce a structure including a radically polymerizable functional group having a carbon-carbon double bond such as a functional group having an unsaturated double bond, for example, the (meth)acrylate (co)polymer (a) having a functional group is copolymerized in advance. monomer with a carbon-carbon double bond, and then use a functional group that can react with the functional group (such as 2-isocyanatoethyl (meth)acrylate, etc.) and an unsaturated double bond. The compound just needs to react with the carbon-carbon double bond while maintaining its hardening properties.

Among them, the (meth)acrylate copolymer (a) is preferably a monomer containing a (meth)acrylate monomer having an active energy ray cross-linkable structural part and a linear alkyl group having 10 to 24 carbon atoms. (meth)acrylate (co)polymer (a-2) as a bulk component. Examples of such (meth)acrylate (co)polymer (a-2) include: (meth)acrylic acid decyl ester (the number of carbon atoms in the alkyl group is 10), (meth)acrylic acid lauryl ester (carbon number: The number is 12), tridecyl (meth)acrylate (the number of carbon atoms is 13), cetyl (meth)acrylate (the number of carbon atoms is 16), stearyl (meth)acrylate (the number of carbon atoms is 16) (18), behenyl (meth)acrylate (22 carbon atoms), etc. These may be used alone, or two or more types may be used in combination.

In addition, among the linear (meth)acrylic acid alkyl ester monomers (a) having an alkyl group having 10 to 24 carbon atoms, the dielectric constant can be lowered and the glass transition temperature of the acrylic resin can be lowered. , preferably alkyl methacrylate is used, especially one having an alkyl group with a carbon number of 12 to 20, most preferably stearyl methacrylate, lauryl methacrylate, or tridecyl methacrylate. ester.

The content of the alkyl (meth)acrylate monomer (a) having a linear alkyl group with a carbon number of 10 to 24 is 50 to 94% by weight, preferably 60%, based on the total (co)polymerization component. ~83% by weight, especially 70~80% by weight. By setting it within the above range, there is no risk that the dielectric constant will become high and the thermal stability of the resin will decrease.

[Crosslinking agent (b)] The cross-linking agent (b) is preferably a cross-linking agent having at least double bond cross-linking. For example, those having a group selected from the group consisting of (meth)acrylyl group, epoxy group, isocyanato group, carboxyl group, hydroxyl group, carbodiimide group, oxazolinyl group, aziridinyl group, vinyl group, and amine group can be listed. The crosslinking agent for at least one crosslinkable functional group of an imine group or a amide group may be used alone or in combination of two or more. In particular, by using two or more cross-linking agents in combination, a higher storage modulus (G') can be achieved compared to the case of using each cross-linking agent individually, even when the total compounding amount is the same. Therefore, it is more preferable to use two or more cross-linking agents (b) in combination. Furthermore, the aspect in which the cross-linking agent (b) and the (meth)acrylate (co)polymer (a) are chemically bonded is also included.

Among them, it is preferable to use a photopolymerizable compound having a carbon-carbon double bond, especially a polyfunctional (meth)acrylate. Here, polyfunctional means having two or more cross-linkable functional groups. Furthermore, it may also have 3 or more or 4 or more crosslinking functional groups if necessary. Furthermore, the above-mentioned crosslinkable functional group may also be protected by a deprotectable protecting group.

Examples of the polyfunctional (meth)acrylate include 1,4-butanediol di(meth)acrylate, glycerol di(meth)acrylate, and neopentyl glycol di(meth)acrylate. , Glyceryl glycidyl ether di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, tricyclodecanedimethyl Acrylate, tricyclodecane dimethanol di(meth)acrylate, bisphenol A polyethoxy di(meth)acrylate, bisphenol A polypropoxy di(meth)acrylate, bisphenol F poly Ethoxy di(meth)acrylate, ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane trioxyethyl(meth)acrylate , ε-caprolactone modified tri(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(acryloyloxyethyl)isocyanurate, Dipentaerythritol hexa(meth)acrylate, Dipentaerythritol penta(meth)acrylate )acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol penta(meth)acrylate, hydroxypivalate neopentyl glycol di(meth)acrylate, hydroxypivalate neopentyl glycol ester ε-Caprolactone adduct di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane polyethoxy tri(meth)acrylate, di-tri Ultraviolet curable polyfunctional (meth)acrylic monomers such as hydroxymethylpropane tetra(meth)acrylate, polyester (meth)acrylate, and epoxy (meth)acrylate may also be used. , (meth)acrylic urethane, polyether (meth)acrylate and other multifunctional (meth)acrylic oligomers. These may be used alone or in combination of two or more.

Among the above-mentioned polyfunctional (meth)acrylates, from the viewpoint of imparting high cohesive force, it is preferable to have a structure in which the distance between cross-linking points in the formed cross-linked structure is short and the cross-linking density is dense, for example Preferably, it is a polyfunctional (meth)acrylate with more than three functions without alkylene oxide modification, preferably selected from the group consisting of pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexacrylate. (Meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol penta(meth)acrylate, trimethylol Polyfunctional (meth)acrylate (b-1) among the group consisting of propane tri(meth)acrylate and di-trimethylolpropane tetra(meth)acrylate. This polyfunctional (meth)acrylate (b-1) can be used alone or in combination (as a mixture) of two or more types.

Moreover, when the above-mentioned polyfunctional (meth)acrylate (b-1) is used as a cross-linking agent, from the viewpoint of compatibility, the above-mentioned (meth)acrylate (a) preferably contains hydrophilic The monomer is a copolymer of monomer components that are polar components. Since the (meth)acrylate (a) contains a polar component, its compatibility with the polyfunctional (meth)acrylate (b-1) becomes good, and the mixture becomes easy to mix when mixed. When stored in a coupled state for a long time, phase separation becomes less likely to occur and there is no risk of the haze value increasing.

Specifically, the (meth)acrylate (co)polymer (a) is preferably a copolymerization of the alkyl (meth)acrylate and the following monomer component as a copolymerizable monomer copolymerizable therewith. The above-mentioned monomer component is a monomer component in which a hydrophilic monomer is appropriately selected from the above-mentioned copolymerizable monomers A to G, which contains the above-mentioned hydrophilic (meth)acrylate, or at least contains a copolymerizable monomer. G: Methyl (meth)acrylate. Furthermore, the (meth)acrylate (co)polymer (a) preferably contains at least methyl (meth)acrylate and a total amount of hydrophilic monomers (selected from copolymerizable monomers A to G). A copolymer of a monomer component accounting for 10 parts by mass or more of the total (meth)acrylate (co)polymer (a).

Furthermore, the (meth)acrylate (co)polymer (a-1) preferably contains a linear or branched chain (formalan) having a carbon number of 4 to 18 in the side chain as a skeleton component (dry component). A copolymer of alkyl acrylate and a monomer component of the above-mentioned hydrophilic monomer as a copolymerizable copolymerizable monomer.

The content of the cross-linking agent (b) is preferably 0.5 to 50 parts by mass relative to 100 parts by mass of the (meth)acrylate (co)polymer (a), and more preferably 1 part by mass or more. Or a ratio of 40 parts by mass or less, and more preferably a ratio of 5 parts by mass or more or 30 parts by mass or less.

[Visible light initiator (c)] The visible light initiator (c) preferably generates free radicals by irradiating visible light, light with at least wavelengths of 390 nm, 405 nm and 410 nm, such as light in the wavelength range of 380 nm to 700 nm, to become (A Visible light initiator that is the starting point for the reaction of acrylate (co)polymer (a). Among them, the visible light initiator (c) may be one that generates free radicals by irradiating only visible light, or may be one that generates free radicals by irradiating light in a wavelength range other than the visible light range.

The visible light initiator (c) preferably has an absorption coefficient of 10 mL/(g·/cm) or more at a wavelength of 405 nm, more preferably 15 mL/(g·/cm) or more, and more preferably 25 mL/(g・/cm) or above. By setting the absorption coefficient at a wavelength of 405 nm to 10 mL/(g·/cm) or more, curing (cross-linking) by irradiation with visible light can be sufficiently performed. On the other hand, the upper limit of the absorption coefficient at a wavelength of 405 nm is preferably 1×10 ⁴ mL/(g·/cm) or less, more preferably 1×10 ³ mL/(g·/cm) or less. Furthermore, it can also be used together with a photoinitiator whose absorption coefficient at the wavelength of 405 nm is less than 10 mL/(g・/cm).

Photoinitiators are roughly classified into two types based on the mechanism of free radical generation. They are roughly divided into: cleavage-type photoinitiators. The single bonds of the photoinitiator itself can be cracked and decomposed to generate free radicals; and hydrogen-abstraction type photoinitiators. , the photoexcited initiator and the hydrogen donor in the system can form an excitation complex, thereby transferring hydrogen from the hydrogen donor.

The cleavage-type photoinitiators among these decompose into other compounds when free radicals are generated by light irradiation. Once excited, they no longer function as reaction initiators. Therefore, it is preferable because it does not remain as an active species in the adhesive after the cross-linking reaction is completed, and there is no possibility of causing undesirable photodegradation to the adhesive. Furthermore, regarding the coloring unique to the photoinitiator, there is a risk of coloring when a cleavage-type visible light initiator (c-1) that is hardened by irradiation with visible light is added to the adhesive. Therefore, as the visible light initiator (c), it is preferable to select one in which the reaction decomposition product does not absorb in the visible light range and is achromatic. On the other hand, the hydrogen-abstracting type photoinitiator not only maintains its function as a reaction initiator even if it is irradiated with light multiple times, but it is also not as effective as the radical generation reaction when irradiating active energy rays such as ultraviolet rays. The cleavage-type photoinitiator generates decomposition products, so it is difficult to become a volatile component after the reaction is completed, and is useful in reducing damage to the adherend. Therefore, a hydrogen abstraction type visible light polymerization initiator (c-2) that starts polymerization when excited by visible light is particularly preferred.

Examples of the above-mentioned cleaved visible light initiator (c-1) include: 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-Hydroxy-2-methyl-1-phenyl-propan-1-one, 1-(4-(2-hydroxyethoxy)phenyl)-2-hydroxy-2-methyl-1-propane- 1-one, 2-hydroxy-1-[4-{4-(2-hydroxy-2-methyl-propanyl)benzyl}phenyl]-2-methyl-propan-1-one, oligomer (2-Hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)acetone), methyl phenylglyoxylate, 2-benzyl-2-dimethylamino-1 -(4-𠰌linylphenyl)butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-𠰌linylpropan-1-one, 2-( Dimethylamino)-2-[(4-methylphenyl)methyl)-1-[4-(4-𠰌linyl)phenyl]-1-butanone, bis(2,4,6- Trimethylbenzyl)-phenylphosphine oxide, 2,4,6-trimethylbenzyldiphenylphosphine oxide, (2,4,6-trimethylbenzyldiphenyl)ethoxy phenylphosphine oxide or their derivatives, etc. Among them, in terms of a method of decolorizing a decomposed product after the reaction, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and 2,4,6-trimethylbenzoylphosphine oxide are preferred. Benzyldiphenylphosphine oxide, (2,4,6-trimethylbenzyl)ethoxyphenylphosphine oxide, bis(2,6-dimethoxybenzyl)2, 4,4-Trimethylpentylphosphine oxide and other acylphosphine oxides are photoinitiators.

Examples of the hydrogen-abstracting visible light initiator (c-2) include bis(2-phenyl-2-side-oxyacetate)oxybis(ethylidene), methyl phenylglyoxylate, and hydroxyphenylacetic acid. A mixture of 2-[2-side oxy-2-phenylacetyloxyethoxy]ethyl ester and 2-[2-hydroxyethoxy]ethyl hydroxyphenylacetate, 9-oxosulfide , 2-chloro-9-oxosulfide𠮿 , 3-Methyl-9-oxosulfide𠮿 , 2,4-dimethyl-9-oxosulfide𠮿 , anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, camphorquinone or its derivatives, etc. Among them, preferred ones are selected from the group consisting of methyl phenylglyoxylate, 2-[2-side-oxy-2-phenylethyloxyethoxy]ethyl hydroxyphenylacetate and 2-[2-hydroxyphenylacetic acid Any one or two of the group consisting of a mixture of hydroxyethoxy]ethyl esters.

Furthermore, the visible light initiator (c) is not limited to those listed above. Any one of the above-listed visible light initiators (c) or derivatives thereof can be used, or two or more types can be used in combination. Furthermore, in addition to the visible light initiator (c), one that only generates free radicals by irradiating other light rays such as ultraviolet rays may be mixed.

The content of visible light initiator (c) is not particularly limited. Preferably, it is contained at a ratio of 0.1 to 10 parts by mass relative to 100 parts by mass of the (meth)acrylate (co)polymer (a) in the adhesive layer (Y), and more preferably 0.5 parts by mass. It is contained at a ratio of not less than 1 part by mass and not more than 5 parts by mass, and more preferably at a ratio of not less than 1 part by mass and not more than 3 parts by mass. By setting the content of the visible light initiator (c) to the above range, appropriate reaction sensitivity to visible light can be obtained.

[Silane coupling agent (d)] The silane coupling agent (d) can improve the adhesion, especially the adhesion to glass materials. Examples of the silane coupling agent include compounds having an unsaturated group such as a vinyl group, an acryloxy group, a methacryloxy group, an amine group, an epoxy group, etc., and a hydrolyzable functional group such as an alkoxy group. . Specific examples of the silane coupling agent include: N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyl Methyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, etc. Among them, in the adhesive layer (Y), γ-glycidoxypropyltrimethoxysilane or γ-methacryloxysilane can be preferably used from the viewpoint of good self-adhesion and less discoloration such as yellowing. Propyltrimethoxysilane. Only one type of the above-mentioned silane coupling agent may be used alone or two or more types may be used in combination.

The content of the silane coupling agent (d) is preferably 0.1 to 5 parts by mass relative to 100 parts by mass of the adhesive layer (Y), and more preferably 0.2 parts by mass or more or 3.0 parts by mass or less. In addition, coupling agents such as organic titanate compounds can also be effectively utilized in the same manner as silane coupling agents.

[other materials] Examples of components other than the above contained in the resin composition forming the adhesive layer (Y) include: light stabilizers, ultraviolet absorbers, metal deactivators, anti-metal corrosion agents, anti-aging agents, and antistatic agents. , hygroscopic agents, foaming agents, defoaming agents, inorganic particles, viscosity adjusters, adhesion-imparting resins, photosensitizers, fluorescent agents and other additives, reaction catalysts (tertiary amine compounds, quaternary ammonium compounds compounds, tin laurate compounds, etc.), etc. Moreover, well-known components prepared in ordinary adhesive compositions may also be suitably contained. Moreover, two or more types of each component may be used together.

Among the above, it is particularly preferred that the resin composition forming the adhesive layer (Y) contains an ultraviolet absorber. As described above, the adhesive layer (Y) has photo-curing properties that are cured by irradiation with light having a wavelength of 405 nm. Therefore, even if it contains an ultraviolet absorber, the photo-curing is not hindered. Therefore, by containing an ultraviolet absorber, the adhesive sheet can have excellent ultraviolet cutoff properties without impairing the properties of the adhesive sheet.

Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, and trisulfide-based ultraviolet absorbers. In addition, the above-mentioned ultraviolet absorbers may be used alone or in combination of two or more types. Among them, from the viewpoint of transparency, ultraviolet absorbability and compatibility, the above-mentioned ultraviolet absorber is particularly preferably a triple-series ultraviolet absorber.

[Preferred composition aspect of this resin composition] An example of a preferred resin composition for forming the adhesive layer (Y) includes a (meth)acrylate (co)polymer (a), the above-mentioned crosslinking agent (b), and a visible light initiator (c). , and the composition of the silane coupling agent if necessary. Among them, it is preferable to use a visible light initiator (c) with an absorption coefficient of 10 mL/(g·/cm) or more at a wavelength of 405 nm as the visible light initiator (c); and it is particularly preferable to use the above-mentioned cleavage type visible light initiator (c). The initiator (c-1) and/or the hydrogen-abstracting visible light initiator (c-2) is used as the visible light initiator (c).

Among them, the (meth)acrylate (co)polymer (a) is preferably formed based on a group selected from the group consisting of carboxyl and epoxy groups, carboxyl and aziridinyl groups, hydroxyl and isocyanate groups, amine groups and isocyanate groups. group, and the chemical bond of any functional group combination of carboxyl group and isocyanate group. Furthermore, the (meth)acrylate (co)polymer (a) preferably contains a linear or branched (meth)acrylic alkyl ester with a carbon number of 4 to 18 in the side chain and the hydrophilic (meth)acrylate A copolymer with acrylic acid ester as the copolymer component. Furthermore, the cross-linking agent (b) is preferably the above-mentioned polyfunctional (meth)acrylate (b-1).

An example of a preferred resin composition for forming the adhesive layer (Y) includes the above-mentioned (meth)acrylate copolymer (a-1), the above-mentioned crosslinking agent (b), and the visible light initiator (c). , and the composition of the silane coupling agent if necessary, the (meth)acrylate copolymer (a-1) includes a graft copolymer having a macromonomer as a branch component. Among them, it is preferable to use a visible light initiator (c) with an absorption coefficient of 10 mL/(g·/cm) or more at a wavelength of 405 nm as the visible light initiator (c); and it is particularly preferable to use the above-mentioned cleavage type visible light initiator (c). The initiator (c-1) and/or the hydrogen-abstracting visible light initiator (c-2) is used as the visible light initiator (c).

Among them, the (meth)acrylate (co)polymer (a-1) preferably contains a linear or branched (methyl) chain having a carbon number of 4 to 18 in the side chain as a skeleton component (dry component). ) alkyl acrylate, a copolymer with the above-mentioned hydrophilic (meth)acrylate as a copolymer component. Moreover, the cross-linking agent (b) is preferably the above-mentioned polyfunctional (meth)acrylate (b-1).

Another example of the preferred resin composition for forming the adhesive layer (Y) is one containing the above-mentioned (meth)acrylate copolymer (a-1), the above-mentioned crosslinking agent (b), the above-mentioned visible light initiator The above-mentioned (meth)acrylate copolymer (a-1) contains a macromonomer as a branch component and an active energy ray cross-linkable structural part. branch copolymer. Among them, it is preferable to use a visible light initiator (c) with an absorption coefficient of 10 mL/(g·/cm) or more at a wavelength of 405 nm as the visible light initiator (c); and it is particularly preferable to use the above-mentioned cleavage type visible light initiator (c). The initiator (c-1) and/or the hydrogen-abstracting visible light initiator (c-2) is used as the visible light initiator (c).

Among them, the (meth)acrylate (co)polymer (a-1) preferably contains a linear or branched (methyl) chain having a carbon number of 4 to 18 in the side chain as a skeleton component (dry component). ) alkyl acrylate, a copolymer with the above-mentioned hydrophilic (meth)acrylate as a copolymer component. Moreover, the cross-linking agent (b) is preferably the above-mentioned polyfunctional (meth)acrylate (b-1).

If the adhesive layer (Y) is formed using the present resin composition having the above composition, the adhesive layer (Y) using (meth)acrylate copolymer (a) or (a-1) as the base resin can be It maintains a sheet shape at room temperature and shows self-adhesiveness, allowing the adhesive to be filled into every corner of the step of the adhered surface of the bonded component. Furthermore, since the visible light initiator (c) can be photocured by visible light irradiation, cohesive force can be improved and foaming resistance reliability can be improved by photocuring. Furthermore, by blending a silane coupling agent, the adhesion, especially the adhesion to glass materials, can be further improved. In addition, the adhesive layer (Y) using (meth)acrylate copolymer (a-1) as the base resin has, in addition to the above, hot melt properties that melt or flow when heated, so it can have a higher level difference. Absorbency.

As another example of the preferred resin composition for forming the adhesive layer (Y), a (meth)acrylate (co)polymer (a-2) containing the following monomer components and the above-mentioned crosslinking agent (b ), the above-mentioned visible light initiator (c), and the composition of the silane coupling agent if necessary. The above-mentioned monomer component includes (methane) having an active energy ray cross-linkable structural part and a linear alkyl group with a carbon number of 10 to 24. base) acrylate monomer. Among them, it is preferable to use a visible light initiator (c) with an absorption coefficient of 10 mL/(g·/cm) or more at a wavelength of 405 nm as the visible light initiator (c); and it is particularly preferable to use the above-mentioned cleavage type visible light initiator (c). The initiator (c-1) and/or the hydrogen-abstracting visible light initiator (c-2) is used as the visible light initiator (c).

If the present resin composition having the composition as described above is used, an adhesive layer (Y) that is temporarily hardened into a state with room for light hardening or an unhardened adhesive layer (Y) can be formed, which can then be irradiated with visible light once or twice or more. And make it light harden. Therefore, for example, after the adhesive sheet is bonded to the adherend, the adhesive sheet can be photocured ("formal hardening") by irradiation with visible light, and the cohesive force can be increased through the formal curing to improve foaming resistance. reliability. In particular, (meth)acrylate (co)polymers, which have high fluidity at room temperature and have difficulty in storage, can be cured even if they undergo a step of temporarily hardening to improve storage properties. Hardening is performed as a subsequent step after visible light hardening after bonding. By further formulating a silane coupling agent, the adhesion, especially the adhesion to glass materials, can be further improved.

(layered structure) As mentioned above, when the adhesive layer (Y) has a laminated structure, from the viewpoint of foaming resistance, it is preferable to use the adhesive layer (Y) of this resin composition as the outermost surface and back layers. At this time, the thickness of the adhesive layer (Y) as the front and back layers is preferably 15 μm or more, more preferably 20 μm or more. If the thickness of the adhesive layer (Y) is 15 μm or more, it is better in the following aspects: In reliability tests, there is less risk of abnormality such as foaming due to the release pressure generated from the adherend member. .

In addition, from the viewpoint of maintaining storage stability, it may be preferable to have another layer with a higher viscosity than the adhesive layer (Y). That is, the adhesive layer (Y) formed by using a graft copolymer with a macromonomer is in an uncrosslinked state before light curing. If a multifunctional (meth)acrylate monomer is used, the multifunctional (meth)acrylate monomer will Due to the effect of the methacrylate monomer component, the adhesive layer (Y) before light curing may become a relatively low viscosity layer. Therefore, in this case, it is preferable to laminate another layer (Z) with a higher viscosity than the adhesive layer (Y) on the adhesive layer (Y). For example, if it is a three-layer multilayer structure including adhesive layer (Y)/layer (Z)/adhesive layer (Y), excellent storage stability can be achieved. From the viewpoint of storage stability, the viscosity of the other layer (Z) is preferably 1 to 10 kPa·s, and more preferably 1.5 to 5 kPa·s in the temperature range of 70°C to 100°C. In addition, the viscosity is a value measured according to the method described in the Example.

Furthermore, when the adhesive sheet has a multi-layered structure as described above, from the viewpoint of having both impact resistance and absorption properties, the glass transition temperature (Tg) of the adhesive sheet after irradiation with 405 nm light is preferably: Less than 20°C, more preferably less than 10°C. By having this adhesive sheet with such a relatively low Tg, the low-temperature adhesive properties (low-temperature peel strength, etc.) can be improved and the adhesive sheet can have impact resistance and absorption properties. Therefore, from the viewpoint of impact resistance and absorption, the Tg of other layers laminated with the above-mentioned adhesive layer (Y) after irradiation with 405 nm light is preferably less than 15°C, and more preferably less than 10°C, especially when it is not reaches 5℃. In addition, the Tg is a value measured at the peak temperature of Tanδ of dynamic viscoelasticity, and specifically, it is a value measured according to the method described in the Examples.

＜Adhesive sheet with release film＞ This adhesive sheet can also be used as an adhesive sheet with a release film. For example, a single-layer or multi-layer sheet-like adhesive layer can be formed on the release film to produce an adhesive sheet with a release film.

As the material of the release film, a known release film can be suitably used. As the material of the release film, for example, polyester film, polyolefin film, polycarbonate film, polystyrene film, acrylic resin film, triacetyl cellulose film, fluororesin film, etc. can be appropriately selected and coated on the film. Use silicone resin that has undergone a release treatment, or release paper, etc.

When a release film is laminated on both sides of the adhesive sheet, one release film may have the same lamination composition or material as the other release film, or may have a different lamination composition or material. Moreover, the thickness may be the same or different thicknesses may be used. In addition, release films with different peeling forces or release films with different thicknesses can be laminated on both sides of the adhesive sheet.

The release film preferably has a light transmittance of 40% or less for light with a wavelength of 410 nm or less. By laminating on at least one surface of this adhesive sheet a release film with a light transmittance of 40% or less for light with a wavelength of 410 nm or less, photopolymerization due to exposure to visible light can be effectively prevented. From this point of view, the release film laminated on one or both surfaces of the adhesive sheet preferably has a light transmittance of 40% or less for light with a wavelength of 410 nm or less, and more preferably 30% or less, where More preferably, it is less than 20%.

Here, as a release film having a light transmittance of 40% or less for light with a wavelength of 410 nm or less, that is, a film that has the function of blocking the transmission of a part of visible light and ultraviolet light, examples thereof include a laminated film including an ultraviolet absorbing layer. , the above-mentioned ultraviolet absorbing layer is coated with a re-peelable micro-adhesive resin on one side of a polyester-based, polypropylene-based, or polyethylene-based cast film or stretch film, and the other side is coated with an ultraviolet absorber. Made of paint. Alternatively, one surface of a polypropylene-based or polyethylene-based cast film or stretched film may be coated with a microadhesive resin that is blended with an ultraviolet absorber and has releasability. Examples include a cast film or stretched film containing a polyester, polypropylene, or polyethylene resin mixed with an ultraviolet absorber, and coated with a releasable microadhesive resin. In addition, one surface of a multi-layer cast film or stretched film coated with a slightly adhesive resin having releasability can be cited. The multi-layer cast film or stretched film is made of a polyester system containing an ultraviolet absorber, One or both sides of the polypropylene-based or polyethylene-based resin layer are formed into a layer containing a resin that does not contain an ultraviolet absorber. Another example is to apply a coating containing an ultraviolet absorber to one surface of a cast film or stretched film containing a polyester-based, polypropylene-based, or polyethylene-based resin to form an ultraviolet absorbing layer, and then apply the coating on the ultraviolet absorbing layer. The cloth is made of slightly adhesive resin with re-peelability. Another example is to apply a coating containing an ultraviolet absorber to one side of a cast film or stretched film containing a polyester, polypropylene, or polyethylene resin to provide an ultraviolet absorbing layer, and to coat the other side with a UV absorbing layer. It is made of peelable slightly adhesive resin. Furthermore, a resin film including a polyester-based, polypropylene-based, or polyethylene-based resin is coated on one surface with a releasable microadhesive resin through an adhesive layer or adhesive layer containing an ultraviolet absorber. The other side is laminated with a separately prepared resin film, etc. The above-mentioned film may also have an antistatic layer, a hard coating layer, an adhesion-promoting layer and other layers as needed.

The thickness of the release film is not particularly limited. Among them, from the viewpoint of processability and handleability, for example, 25 μm to 500 μm is preferred, 38 μm or more or 250 μm or less is more preferred, and 50 μm or more or 200 μm or less is particularly preferred.

Furthermore, this adhesive sheet can also be made by the following method: without using an adherend or a release film as mentioned above, for example, the method of directly extruding the resin composition, or by injecting it into a mold. The method of forming. Furthermore, the present resin composition may be directly filled between the constituent members for an image display device as an adherend, thereby forming the present adhesive sheet.

＜Manufacturing method of this adhesive sheet＞ An example of a method of manufacturing this adhesive sheet will be described. First, (meth)acrylate (co)polymer (a) and visible light initiator (c), if necessary, then cross-linking agent (b), if necessary, then silane coupling agent (d), if necessary Furthermore, other materials may be mixed in specific amounts to prepare the resin composition. The mixing method is not particularly limited, and the order in which the components are mixed is not particularly limited. In addition, a heat treatment step may be added when producing the composition. In this case, it is desirable to mix each component of the resin composition in advance and then perform heat treatment. Alternatively, various mixed components may be concentrated and turned into a masterbatch.

There are no special restrictions on the mixing device. For example, a universal mixer, a planetary mixer, a Banbury mixer, a kneader, a frame mixer, a pressure kneader, a three-roller mill, and a two-roller mill can be used. Solvents can also be used for mixing if necessary. Moreover, this resin composition can be used as a solvent-free system which does not contain a solvent. By using it as a solvent-free system, the following advantages can be obtained: no solvent remains, and heat resistance and light resistance are improved. From this viewpoint, it is also preferable that the resin composition contains a (meth)acrylate (co)polymer (a), a cross-linking agent (b), and a visible light initiator (c).

The adhesive sheet can be produced by coating (coating) the resin composition prepared in the above manner on a base sheet or a release sheet. Moreover, for example, the present adhesive sheet having a laminated structure can be produced by repeating the following steps, that is, applying (coating) the present resin composition to a base sheet or a release sheet. , forming the first layer, coating (coating) the resin composition on the formed first layer to form the second layer; forming the first layer and the second layer in the same manner as above, and then applying each A method of bonding the coated surfaces to each other; or a method of simultaneously forming the first layer and the second layer of the resin composition through multi-layer coating or co-extrusion molding.

The above coating (coating) method can be used without particular limitation as long as it is a general coating method. For example, methods such as roller coating, die coating, gravure coating, notched wheel coating, and screen printing can be cited.

Then, if necessary, the adhesive layer containing the above resin composition is irradiated with light to temporarily harden the adhesive layer (Y), leaving room for photohardening, and the gel fraction of the adhesive layer (Y) is set to 0 to 60%. . However, the adhesive layer (Y) may be temporarily hardened without irradiating light. For example, the adhesive layer (Y) may be temporarily hardened by heat or curing, or may be in an uncured state.

＜Use of this adhesive sheet＞ This adhesive sheet can be suitably used for bonding the resin member (X) as described above. Therefore, it is possible to provide an adhesive sheet laminated body (referred to as "the present adhesive sheet laminated body") consisting of a resin member (X) having specific characteristics and the adhesive sheet laminated thereon.

The adhesive sheet laminate can be produced, for example, by the following steps: using a resin composition containing a (meth)acrylate (co)polymer and a visible light initiator to prepare the adhesive sheet, and laminating the adhesive sheet to the above-mentioned resin member (X). However, the manufacturing method of this adhesive sheet laminated body is not limited to this method.

(Resin component (X)) The resin member (X) preferably has a light transmittance of 10% or less at 365 nm and a light transmittance of 60% or more at 405 nm.

If the light transmittance of the resin member (X) at 365 nm is less than 10% and the light transmittance at 405 nm is more than 60%, the transmission of ultraviolet rays can be fully blocked (cut off) and the resin member (X) can be suppressed. Light deterioration of itself and optical components (such as optical films such as polarizing films or retardation films) located on the back side (opposite to the visible side) can reduce the yellowness (YI) to the level required by the optical components. Examples of such a resin member (X) include a resin material as a main component and an ultraviolet absorber adjusted to have the above-mentioned light transmittance.

Examples of the resin material include materials containing polycarbonate resin or acrylic resin as a main component resin. At this time, the "main component resin" refers to the resin containing the largest mass among the resins constituting the resin member (X).

Moreover, regarding this adhesive sheet, for example, the above-mentioned resin member (X) and the image display panel (P) can be bonded together via this adhesive sheet to form a photocurable adhesive sheet laminate. From this resin member (X) ) side through the resin member (X), the adhesive sheet is irradiated with a cumulative light amount of 405 nm to become 3000 (mJ/cm ² ) light, thereby photo-hardening the adhesive layer (Y) and condensing it to achieve the results before and after photo-hardening. The gel fraction difference becomes 10% or more, and an image display panel laminated body is manufactured.

This adhesive sheet laminated body can be bonded to an image display panel (P), for example, to produce an image display panel laminated body. Specifically, the image display panel laminate including the adhesive sheet laminate and the image display panel (P) can be formed by laminating the resin member (X) and the image display panel (P) through, for example. After the adhesive sheet is laminated, light with a wavelength of 405 nm is irradiated from the outside of the resin member (X) through the resin member (X) to formally harden the adhesive layer (Y) of the adhesive sheet and the above-mentioned resin member ( X) is bonded to the image display panel (P) to produce an image display panel laminate. Furthermore, the method of laminating the resin member (X) and the image display panel (P) via this adhesive sheet is not particularly limited, and either the resin member (X) or the image display panel (P) can be laminated. After one is laminated with the adhesive sheet, the other is laminated with the adhesive sheet. Alternatively, the resin member (X) and the image display panel (P) can be laminated with the adhesive sheet at the same time.

(Image display panel (P)) Examples of the image display panel (P) include polarizing films, other optical films such as retardation films, liquid crystal materials, and backlight systems (normally, the composition or adhesive article is If the adhesive surface becomes an optical film), depending on the control method of the liquid crystal material, there are STN method, VA method, IPS method, etc., and it can be any method. Furthermore, the image display panel may be an in-cell type in which the touch panel function is built into the TFT-LCD, or it may be a type in which the touch panel function is built in between a glass substrate provided with a polarizing plate and a color filter. Table embedded type.

As for this adhesive sheet, from the viewpoint of foaming resistance reliability, it is particularly preferable that the adhesive layer (Y) is in a state of being in contact with the target object as described above, that is, the adhesive layer (Y) after light (this) curing Y) has the cross-linked structure of this resin composition. In particular, the adhesive layer (Y) is preferably a (meth)acrylate copolymer having an active energy ray-curable portion as described above, or a (meth)acrylate (co-polymer) having a functional group (i). ) Polymer (a), a chemical bond with a compound having a functional group (ii) that reacts with the functional group (i), or the use of a trifunctional or higher polyfunctional (meth)acrylate without alkylene oxide modification It is formed and has a cross-linked structure caused by these.

＜＜Explanation of statements, etc.＞＞ In the present invention, when it is called "film", it also includes "sheet", and when it is called "sheet", it also includes "film". In addition, the term "panel" such as an image display panel, a protective panel, etc. includes a board, a sheet, and a film.

In the present invention, when it is described as "X～Y" (X and Y are arbitrary numbers), unless otherwise specified, it includes the meaning of "more than X and less than Y" and "preferably greater than X" or " "Preferably less than Y" means. In addition, when it is described as "more than X" (X is an arbitrary number), it means "preferably greater than In this case, unless otherwise specified, it means "preferably less than Y". [Example]

Hereinafter, the method will be further described in detail through examples. However, the present invention is not limited to the examples described below.

<Examples, Comparative Examples> Materials used in Examples and Comparative Examples will be described.

[Example 1] (Photocurable adhesive sheet Y) As a (meth)acrylate (co)polymer, a macromonomer (number average molecular weight) containing isotrimethacrylate:methyl methacrylate=1:1 and having a terminal functional group of methacryloyl group is prepared. An acrylic graft copolymer (mass average molecular weight: 160,000). 90 g of propoxylated pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ESTER ATM-4PL) was added as a cross-linking agent per 1 kg of the acrylic graft copolymer, and cleavage was included as a visible light initiator. A mixture of visible light initiators, namely 2,4,6-trimethylbenzyldiphenylphosphine oxide, oligo(2-hydroxy-2-methyl-1-(4-(1-methyl (vinyl) phenyl) acetone), 2,4,6-trimethylbenzophenone, 4-methylbenzophenone mixture (Esacure KTO46 manufactured by Lamberti Company) 15 g, mix evenly to obtain light Hardening composition. Next, the above-mentioned photocurable composition was formed into a sheet on a polyethylene terephthalate film (manufactured by Mitsubishi Plastics Co., Ltd., DIAFOIL MRV, thickness 100 μm) with a surface peeling treatment so that the thickness became 150 μm. The material shape is then covered with a polyethylene terephthalate film (DIAFOIL MRQ, thickness 75 μm, manufactured by Mitsubishi Plastics Corporation) that has been peeled off the surface to produce a light-curable adhesive sheet Y1 with a release film. Furthermore, the photocurable adhesive sheet Y1 is a photocurable adhesive sheet that is cured by irradiation with light.

(Resin componentX) As the resin member (X), a polycarbonate-based resin sheet containing an ultraviolet absorber (Iupilon sheet MR58 manufactured by Mitsubishi Gas Chemical Co., Ltd.) with a thickness of 1.0 mm (used in the lamination structure P) and 1.5 mm (used in the lamination structure P) was used. Used in bonding structure Q and bonding structure R). For any thickness, the light transmittance at 365 nm is 0% and the light transmittance at 405 nm is 83%.

(Photocurable adhesive sheet laminate) Peel off the release film on one side of the photo-curable adhesive sheet Y1 with the release film, and bond it to one side of the polycarbonate plate (resin member X) with a roller to obtain the resin member (X)/photo-cured Photo-curable adhesive sheet laminated body of the adhesive sheet Y1 (also called "X/Y1 laminated body").

[Example 2] The type of cross-linking agent of the photocurable adhesive sheet Y was changed to pentaerythritol triacrylate (NK ESTER ATMM3 manufactured by Shin-Nakamura Chemical Co., Ltd.), and the proportion of the mixture was changed to 1 kg of the acrylic graft copolymer. It was 70 g, except that it carried out similarly to Example 1, and obtained the photocurable adhesive sheet Y2 and the X/Y2 laminated body. Furthermore, the photocurable adhesive sheet Y2 is a photocurable adhesive sheet that is cured by irradiation with light.

[Example 3] The composition of the (meth)acrylic copolymer of the photocurable adhesive sheet Y is changed so that the terminal functional group is a methacryl group with respect to the terminal functional group containing isoester methacrylate: methyl methacrylate = 1:1. 12.7 parts by mass of macromonomer (number average molecular weight: 3000), 41.1 parts by mass of lauryl acrylate, 37.6 parts by mass of 2-ethylhexyl acrylate, 2.6 parts by mass of acrylamide, and 6 parts by mass of 4-hydroxybutyl acrylate. 100 parts by mass of a hydroxyl-containing acrylic graft copolymer (mass average molecular weight: 160,000) obtained by random copolymerization and 6.5 parts by mass of 2-isocyanatoethyl methacrylate obtained by addition reaction with carbon- The photocurable adhesive sheet Y3 and the X/Y3 laminated body were obtained in the same manner as in Example 1 except for the (meth)acrylic copolymer of the active energy ray crosslinkable structural portion of the carbon double bond. Furthermore, the photocurable adhesive sheet Y3 is a photocurable adhesive sheet that is cured by irradiation with light.

[Example 4] As a photocurable adhesive sheet, the hydrogen-abstracting visible light initiator phenylglyoxylic acid methyl ester (Irgacure MBF, manufactured by BASF) was used as a visible light initiator. The ^photocurable adhesive sheets Y4 and /Y4 laminated body. Furthermore, the photocurable adhesive sheet Y4 is a photocurable adhesive sheet that is cured by irradiation with light.

[Example 5] As the (meth)acrylate (co)polymer, a macromonomer containing isotrimethacrylate:methyl methacrylate=1:1 with a terminal functional group of methacrylyl group (number average molecular weight: Acrylic graft copolymer (mass average molecular weight: 26) randomly copolymerized 13.5 parts by mass of 3000), 73.7 parts by mass of 2-ethylhexyl acrylate, 2.8 parts by mass of acrylamide and 10 parts by mass of methacrylate. million), and the type of cross-linking agent was changed to pentaerythritol triacrylate (NK ESTER ATMM3L manufactured by Shin-Nakamura Chemical Co., Ltd.), and the proportion of the mixture was changed to 70 g per 1 kg of acrylic graft copolymer, Otherwise, it carried out similarly to Example 1, and obtained the photocurable adhesive sheet Y5 and the X/Y5 laminated body. Furthermore, the photocurable adhesive sheet Y5 is a photocurable adhesive sheet that is cured by irradiation with light.

[Example 6] Except for changing the compounding amount of the crosslinking agent to 120 g per 1 kg of the acrylic graft copolymer, the same procedure as in Example 5 was performed to obtain the photocurable adhesive sheet Y6 and the X/Y6 laminate. . Furthermore, the photocurable adhesive sheet Y6 is a photocurable adhesive sheet that is cured by irradiation with light.

[Example 7] The type of cross-linking agent was adjusted to 1 kg of the acrylic graft copolymer, and pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ESTER ATMM3L) and dipentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK) were used in combination. ESTER A9570W) 90 g and 30 g each, except that the same procedure as in Example 5 was carried out to obtain a photocurable adhesive sheet Y7 and an X/Y7 laminated body. Furthermore, the photocurable adhesive sheet Y7 is a photocurable adhesive sheet that is cured by irradiation with light.

[Example 8] The type of cross-linking agent was adjusted to 1 kg of the acrylic graft copolymer, and pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ESTER ATMM3L) and dipentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK) were used in combination. ESTER A9570W), 120 g and 40 g each, were carried out in the same manner as in Example 5, to obtain photocurable adhesive sheets Y8 and X/Y8 laminated bodies. Furthermore, the photocurable adhesive sheet Y8 is a photocurable adhesive sheet that is cured by irradiation with light.

[Example 9] Relative to a macromonomer (number average molecular weight 3,000) containing isotrimethacrylate: methyl methacrylate = 1:1 as a (meth)acrylic copolymer with a terminal functional group of methacryloyl group (number average molecular weight: 3,000) An acrylic graft copolymer (mass average molecular weight: 260,000) produced by random copolymerization of 73.7 parts by mass of 2-ethylhexyl acrylate, 2.8 parts by mass of acrylamide and 10 parts by mass of methacrylate. kg, using pentaerythritol triacrylate (NK ESTER ATMM3L, manufactured by Shin-Nakamura Chemical Co., Ltd.) and dipentaerythritol tetraacrylate (NK ESTER A9570W, manufactured by Shin-Nakamura Chemical Co., Ltd.) as cross-linking agents in amounts of 75 g and 25 g respectively, Add as a visible light initiator a mixture containing a cleaved visible light initiator, namely 2,4,6-trimethylbenzoyldiphenylphosphine oxide, oligo(2-hydroxy-2-methyl- A mixture of 1-(4-(1-methylvinyl)phenyl)acetone), 2,4,6-trimethylbenzophenone, and 4-methylbenzophenone (Esacure KTO46 manufactured by Lamberti Corporation ) 15 g, and uniformly mixed 2 g of 3-glycidoxypropyltrimethoxysilane (KBM403 manufactured by Shin-Etsu Silicone Co., Ltd.) as a silane coupling agent to obtain a photocurable composition. Next, the above-mentioned photocurable composition was molded so that the thickness became 25 μm on a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, DIAFOIL MRV, thickness 100 μm) that had been peeled off. It is in the form of a sheet and is then coated with a polyethylene terephthalate film (made by Mitsubishi Chemical Corporation, DIAFOIL MRQ, thickness 75 μm) that has been peeled off the surface to produce an adhesive sheet for the front and back layers with a release film. Y9a.

To 1 kg of the same acrylic graft copolymer as the (meth)acrylic copolymer used in the adhesive sheet Y9a for the front and back layers, pentaerythritol triacrylate (Shin Nakamura Chemical Co., Ltd.) was added as a cross-linking agent. Manufactured by the company, NK ESTER ATMM3L) 30 g, as a visible light initiator, a mixture containing a cleavage type visible light initiator, namely 2,4,6-trimethylbenzyldiphenylphosphine oxide, oligo( 2-Hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), 2,4,6-trimethylbenzophenone, 4-methylbenzophenone 15 g of the mixture (Esacure KTO46 manufactured by Lamberti Company) was uniformly mixed to obtain a photocurable composition. Next, the above-mentioned photocurable composition was molded so that the thickness became 100 μm on a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, DIAFOIL MRV, thickness 100 μm) that had been peeled off. It is in the form of a sheet and is then coated with a polyethylene terephthalate film (made by Mitsubishi Chemical Corporation, DIAFOIL MRQ, thickness 75 μm) that has been peeled off the surface to produce an adhesive sheet Y9b for the intermediate layer with a release film. .

The PET films on both sides of the adhesive sheet Y9b for the middle layer are peeled off and removed in sequence, and the adhesive surfaces of the two adhesive sheets Y9a for the front and back layers are sequentially attached to the two surfaces of the adhesive sheet Y9b for the middle layer, to obtain Photocurable adhesive sheet Y9. The photocurable adhesive sheet Y9 includes (adhesive sheet Y9a for front and back layers)/(adhesive sheet Y9b for intermediate layers)/(adhesive sheet Y9a for front and back layers). Two types of 3-layer laminated bodies (total thickness: 150 μm) were prepared in the same manner as in Example 1 to obtain an X/Y9 laminated body.

[Example 10] The (meth)acrylic copolymer used in the above-mentioned adhesive sheet Y9b for the intermediate layer is changed to contain isopropyl methacrylate:methyl methacrylate=1:1 and the terminal functional group is a methacrylate group. An acrylic joint made of random copolymerization of 13.5 parts by mass of macromonomer (number average molecular weight: 3,000), 43.7 parts by mass of lauryl acrylate, 40 parts by mass of 2-ethylhexyl acrylate, and 2.8 parts by mass of acrylamide. The dendritic copolymer (mass average molecular weight: 160,000) was used to form the adhesive sheet Y10b for the intermediate layer. Except for this, the same procedure as in Example 9 was carried out to obtain the photocurable adhesive sheet Y10 and the X/Y10 laminate. The photocurable The adhesive sheet Y10 is a three-layer laminate of two types (total thickness 150 μm). Furthermore, the photocurable adhesive sheet Y10 is a photocurable adhesive sheet that is cured by irradiation with light.

[Comparative example 1] As the photocurable adhesive sheet, a hydrogen-abstracting initiator is used as a photoinitiator, that is, a mixture of 2,4,6-trimethylbenzophenone and 4-methylbenzophenone (Lamberti Co., Ltd., Esacure TZT), except that it was carried out in the same manner as in Example 1 to obtain a photocurable adhesive sheet Y11 and an X/Y11 laminated body.

[Comparative example 2] As the photocurable adhesive sheet, a hydrogen-abstracting initiator that is a photoinitiator, namely 1-[4-(4-benzylphenylthio)phenyl]-2-methyl- Except for using 2-(4-methylphenylsulfonyl)propan-1-one (Esacure1001M manufactured by Lamberti Corporation), the same procedure as in Example 1 was performed to obtain photocurable adhesive sheet Y12 and X/Y12 laminate. body.

[Comparative example 3] As the photocurable adhesive sheet, the photocurable adhesive sheets Y13 and /Y13 laminated body.

[Comparative example 4] As the resin member It carried out similarly to Example 1, and obtained the photocurable adhesive sheet Y14 and the X/Y14 laminated body.

＜Evaluation＞ The evaluation method shown in this specification will be described.

(1) Dynamic storage modulus (G') Eight of the 150 μm photocurable adhesive sheets Y1 to Y14 (without release film) obtained in the Examples and Comparative Examples were overlapped to become 1200 μm, and a dynamic viscoelasticity measuring device rheometer was used. ("MARS" manufactured by Eiko Seiki Co., Ltd.), measured under the conditions that the adhesive jig is a Φ25mm parallel plate, the strain is 0.5%, the frequency is 1 Hz, and the temperature rise rate is 3°C/min.

(2)Spectral transmittance Regarding the resin member (X), a spectrophotometer (UV2000 manufactured by Shimadzu Corporation) was used to measure the spectral transmittance (%T) at a wavelength of 300 nm to 800 nm. Let this spectral transmittance be the light transmittance.

(3) Gel fraction Each of the photocurable adhesive sheets Y1 to Y14 (without release film) obtained in the Examples and Comparative Examples was wrapped in a bag shape with a SUS net (♯200) whose mass (X) was measured in advance, Fold the mouth of the bag to seal it, measure the mass (Y) of the bag, then immerse it in 100 ml of ethyl acetate, store it in the dark at 23°C for 24 hours, take out the bag and heat it at 70°C for 4.5 hours. The adhered ethyl acetate was evaporated, the mass (Z) of the dried bag was measured, and the gel fraction X1 was calculated by substituting the calculated mass into the following formula. Gel fraction (%) = [(Z-X)/(Y-X)]×100

Furthermore, for each of the X/Y1 to Y14 laminates obtained in the Examples and Comparative Examples, a high-pressure mercury lamp was used from the resin member (X) side so that the cumulative light intensity at 405 nm became 3000 (mJ/cm ² ). After irradiating light, a sample is taken from the adhesive layer portion of the surface of the resin member (X) side of the photocurable adhesive sheet, and the gel fraction X2 is determined by the same method as above. And calculate X2-X1.

(4) Step difference absorption Print the peripheral part (long side 3 mm, short side 15 mm) of 58 mm Glass plate with printed steps. For each of the release film-attached photo-curable adhesive sheets Y1 to Y14 obtained in the Examples and Comparative Examples, one release film was peeled off, and they were bonded to soda-lime glass (54 mm × 82 mm × thickness) with a roller. 0.5 mm) on the entire surface, peel off the other remaining release film, and use vacuum pressure to perform vacuum pressure bonding by covering the frame-shaped printing step of the above-mentioned glass plate with printing step with an adhesive sheet ( The temperature is 25°C and the pressurizing pressure is 0.13 MPa) to prepare an evaluation sample. After the evaluation sample is autoclaved under the conditions of 60°C, 0.2 MPa, and 20 minutes, pass or fail is determined based on the following evaluation criteria. ○ (Good): No microbubbles are seen at all around the step. × (Difference): Micro bubbles are seen around the step difference

(5) Yellowness (YI) Regarding each of the X/Y1 to Y14 laminated bodies obtained in the Examples and Comparative Examples, the cumulative light intensity at 405 nm from the resin member (X) side was 3000 (mJ) using a high-pressure mercury lamp. /cm ² ). The so-called integrated light amount at 405 nm is measured using the ultraviolet integrated light meter "UIT-250" (manufactured by Ushio Electric Co., Ltd.) and the light receiver "UVD-C405" (manufactured by Ushio Electric Co., Ltd.) on the resin member (X) The cumulative amount of light transmitted through the resin member (X) and irradiated onto the photocurable adhesive sheet (Y1 to Y14) is measured by installing a light meter on the opposite side of the side where the high-pressure mercury lamp is irradiated. Thereafter, the yellowness (YI) of the X/Y1 to Y14 laminates was measured based on JIS K7103 using a spectrophotometer (Suga Testing Machinery Co., Ltd.) "SC-T", and pass or failure was determined based on the following evaluation criteria. . ○ (Good): YI is less than 2 × (Poor): YI is 2 or more

(6) UV resistance reliability (ΔYI) Regarding the X/Y1 to Y14 laminated bodies obtained in the Examples and Comparative Examples, the cumulative light intensity at 405 nm from the resin member (X) side was 3000 (mJ) using a high-pressure mercury lamp. /cm ² ). The so-called integrated light amount at 405 nm is measured using the ultraviolet integrated light meter "UIT-250" (manufactured by Ushio Electric Co., Ltd.) and the light receiver "UVD-C405" (manufactured by Ushio Electric Co., Ltd.) on the resin member (X) The cumulative amount of light transmitted through the resin member (X) and irradiated onto the photocurable adhesive sheet (Y1 to Y14) is measured by installing a light meter on the opposite side of the side where the high-pressure mercury lamp is irradiated. Thereafter, a UVB fluorescent lamp (G15T8E, manufactured by Sankyo Electric Co., Ltd., irradiance: 70 μW/cm ² ) was used to perform an irradiation test at a distance of 20 cm and 72 hr. Based on the change amount ΔYI in the yellowness (YI) of the X/Y1 to Y14 laminated body before and after irradiation, pass or fail was determined based on the following evaluation criteria. ○ (Good): ΔYI is less than 0.2 × (Poor): ΔYI is 0.2 or more

(7) Foaming resistance reliability Regarding each of the X/Y laminated bodies obtained in the Examples and Comparative Examples, the other release film remaining on the Y surface side was peeled off, and the following three types of members were attached to the exposed surface with a hand roller, and each evaluation was performed Foaming resistance and reliability during bonding. Furthermore, the X/Y laminated body is cut into the size of each component and used. The specific bonding structures are X/Y laminated body/member P (laminated structure P), X/Y laminated body/member Q (laminated structure Q), and X/Y laminated body/member R (laminated structure R) These 3 types. Component P: soda-lime glass 54 mm×82 mm×thickness 0.55 mm Component Q: Soda-lime glass 100 mm×180 mm×thickness 0.55 mm Component R: PET film 100 mm×180 mm×thickness 100 μm

In addition, for member P (laminated structure P), an autoclave treatment was performed at a temperature of 60°C, an air pressure of 0.2 MPa, and 30 minutes for final bonding. For members Q and R (laminated structure Q and R ), perform autoclave treatment at a temperature of 80°C, an air pressure of 0.2 MPa, and 30 minutes for final bonding.

After the above final bonding, a high-pressure mercury lamp was used to irradiate light from the resin member (X) side so that the cumulative light intensity at 405 nm became 3000 (mJ/cm ² ), and a foaming resistance reliability evaluation sample was produced. The above evaluation samples were exposed to an environment of 85°C and 85% RH for 24 hours. Those with no appearance defects such as foaming or peeling were judged as "○ (good)", and those with foaming or peeling were judged as "× ( Difference)". In addition, if no appearance defects such as foaming or peeling are found in the lamination structure P or Q (single-sided glass member) and the lamination structure R (double-sided resin member), the overall judgment will be "◎ (Excellent)". If no appearance defects such as foaming or peeling are found in any of the lamination structures P, Q and R, the overall judgment is "0 (good)". If foaming or peeling is found in all of the lamination structures P, Q and R The overall judgment is "× (poor)".

(8) Haze after long-term storage (an indicator of compatibility with the cross-linking agent) Regarding each of the photocurable adhesive sheets Y obtained in the Examples and Comparative Examples, 2 months passed after the sheet was produced. After the above, laminate the adhesive sheet Y by sandwiching the double-sided adhesive surfaces exposed by peeling off the release film between two pieces of soda-lime glass (thickness: 0.55 mm), and use a high-pressure mercury lamp to illuminate at 405 nm. After irradiating the light so that the cumulative light intensity reaches 3000 (mJ/cm ² ), measure the haze value. The haze value was measured in accordance with JIS K7136 using a haze meter (NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd.). Those with a haze value of less than 0.5 are judged as "○ (good)", those with a haze value of 0.5 or more and less than 1.0 are judged as "△ (fair)", and those with a haze value of 1.0 or more are judged as " × (poor)".

(9) Tg after photocuring For each of the 150 μm photocurable adhesive sheets Y1 to Y14 (without release film) obtained in the Examples and Comparative Examples, the cumulative light amount at 405 nm was previously set to 3000 ( mJ/cm ² ), eight pieces of the photocurable adhesive sheets Y1 to Y14 were overlapped to become 1200 μm, and a dynamic viscoelasticity measuring device rheometer (manufactured by Eiko Seiki Co., Ltd.) was used. MARS"), measured under the conditions that the adhesive fixture is a Φ25 mm parallel plate, the strain is 0.5%, the frequency is 1 Hz, and the temperature rise rate is 3°C/min. The temperature at which the obtained Tanδ value becomes the peak is measured as Tg.

(10)Viscosity About each of the 150 μm photocurable adhesive sheets Y1 to Y14 (without release film) obtained in the Examples and Comparative Examples, eight of them were overlapped to become 1200 μm, and flown using a dynamic viscoelasticity measuring device. A variable gauge ("MARS" manufactured by Eiko Seiki Co., Ltd.) was used to measure 70°C, 100 Reviscosity of the adhesive sheet before light hardening at ℃.

(11) Custody The light-hardening adhesive sheets Y1 to Y14 cut into 50 mm After leaving it in the same environment for 300 hours, visually observe whether the adhesive overflows from the laminate. The prepared laminated body was visually observed and judged as "× (poor)" if the adhesive overflowed entirely, "△ (fair)" if the adhesive only overflowed from the corners, and "△ (fair)" if the adhesive did not overflow. It is "○(good)".

[Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Resin componentsX Light transmittance (%) 365 nm 0 0 0 0 0 0 0 0 0 0 0 0 0 45 Light transmittance (%) 405 nm 83 83 83 83 83 83 83 83 83 83 83 83 83 91 Adhesive layer of photocurable adhesive sheet Y Light transmittance (%) 390 nm 77 77 77 86 76 76 76 76 76 76 91 91 90 77 Light transmittance (%) 410 nm 90 90 90 92 88 88 88 88 88 88 92 92 91 90 Gel fraction X1 (%) 0 0 0 45 0 0 0 0 0 0 0 0 88 0 Dynamic storage modulus (G') (25℃) (Pa) 3.8×10 ⁴ 4.1×10 ⁴ 7.9×10 ⁴ 6.5×10 ⁴ 6.0×10 ⁴ 5.4×10 ⁴ 5.4×10 ⁴ 5.1×10 ⁴ 8.2×10 ⁴ 5.4×10 ⁴ 3.8×10 ⁴ 3.8×10 ⁴ 9.0×10 ⁴ 3.8×10 ⁴ Viscosity (Pa.s)(70℃) 1050 1120 1139 1630 1405 1178 1290 1080 1930 1570 1018 1091 13700 1018 Viscosity (Pa.s)(100℃) 154 169 168 398 334 273 291 266 436 379 149 170 14100 149 Custody △ △ △ 〇 △ △ △ △ 〇 〇 △ △ 〇 △ X/Y layered body step difference absorptivity 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 × 〇 Tg(℃) after 405 nm light irradiation 0 5 9 -1 twenty one 37 40 43 4 twenty one -5 -5 0 -5 Gel fraction after 405 nm light irradiation X2 (%) 78 82 88 74 78 80 82 86 69 74 0 0 90 81 X2-X1(%) 78 82 88 29 78 80 82 86 69 74 0 0 2 81 Dynamic storage modulus after 405 nm light irradiation (G') (120℃) (Pa) 0.8×10 ⁴ 3.3×10 ⁴ 9.3×10 ⁴ 0.8×10 ⁴ 4.0×10 ⁴ 1.7×10 ⁵ 2.2×10 ⁵ 2.7×10 ⁵ 2.4×10 ⁴ 3.4×10 ⁴ 5.7×10 ¹ 5.7×10 ¹ 5.4×10 ⁴ 0.8×10 ⁴ Foaming resistance reliability 〇 〇 ◎ 〇 〇 〇 ◎ 〇 ◎ ◎ × × ◎ 〇 Fitting structure P: X/Y/Glass size: 54×82 mm 〇 〇 〇 〇 - - - - - - × × 〇 〇 Fitting structure Q: X/Y/glass size: 100×180 mm 〇 〇 〇 〇 〇 〇 〇 × 〇 〇 × × 〇 〇 Fitting structure R: X/Y/PET Size: 100×180 mm × × 〇 × × × 〇 〇 〇 〇 × × 〇 × Yellowness (YI) 〇1.85 〇1.85 〇1.85 〇1.85 〇1.85 〇1.85 〇1.85 〇1.85 〇1.85 〇1.85 〇1.82 〇1.82 〇1.90 〇1.76 UV resistance reliability (ΔYI) 〇0.2 〇0.2 〇0.2 〇0.2 〇0.2 〇0.2 〇0.2 〇0.2 〇0.2 〇0.2 〇0.2 〇0.2 〇0.2 × 1.65 Haze after long-term storage 〇0.3 △ 0.6 〇0.3 〇0.3 〇0.3 〇0.3 〇0.3 〇0.3 〇0.3 〇0.3 〇0.3 〇0.3 〇0.3 〇0.3

<Inspection> The photocurable adhesive sheet laminate (X/Y1 to Y10 laminate) of the resin member (X)/photocurable adhesive sheet (Y1 to Y10) of Examples 1 to 10 was obtained from the resin member (X ) side is irradiated with light in such a manner that the cumulative light intensity at a wavelength of 405 nm becomes 3000 (mJ/cm ² ), the photocurable adhesive sheets Y1 to Y10 can be fully cured until the gel fraction difference increases by more than 10%, and the dynamic storage The modulus (G') maintains a high-temperature cohesion of more than 0.7×10 ⁴ Pa at 120°C and 1 Hz, thus achieving good foaming resistance reliability. In particular, the touch sensor achieved good foaming resistance reliability in tests assuming the situation of a glass sensor. Among them, the dynamic storage modulus (G') of Examples 3, 7, 9, and 10 maintains a high-temperature cohesion of more than 2.0×10 ⁴ Pa at 120°C and 1 Hz. Therefore, the touch sensor is assumed to be a film sensor. Good foaming resistance reliability was also obtained in the test.

In addition, although the touch sensor in Example 8 obtained good foaming resistance reliability in the test assuming a film sensor, the touch sensor produced glass in the test assuming a glass sensor. of peeling off. The reason is believed to be that the dynamic storage modulus (G') becomes too high at 120°C and 1 Hz, and the viscosity and adhesion performance decrease. Furthermore, in Example 2, since the content of the hydrophilic monomer constituting the (meth)acrylate (co)polymer (a) is 10 parts by mass or less, phase separation occurs during long-term storage, so the fog after long-term storage The degree is "△(fair)". Examples 1 to 10 have good step absorption properties, and the cover member with printed steps can be used in practical applications depending on the type of touch sensor.

In addition, the viscosity (70°C) of Examples 4, 9, and 10 was as high as 1.5 kPa·s or more. Therefore, no paste overflow was found even after long-term storage, and the storage properties were excellent.

The light transmittance (%) of the photocurable adhesive sheets Y11 and Y12 of Comparative Examples 1 and 2 at a wavelength of 390 nm is as high as more than 90%, and the cumulative light amount at a wavelength of 405 nm from the resin member (X) side is 3000 ( When irradiating light with the method of mJ/cm ² ), because the photoinitiator absorbs light and performs excitation and hardening (cross-linking) reactions insufficiently, the adhesive layer (Y) cannot be fully hardened. In the foaming resistance reliability test bubbles are produced.

The photocurable adhesive sheet Y13 of Comparative Example 3 has a gel fraction of 88% and a dynamic storage modulus (G') (25°C) as high as 1.1×10 ⁵ Pa. Therefore, the step absorption is poor and bubbles are generated. The resin member (X) of Comparative Example 4 does not contain a UV absorber and has a light transmittance of 45% at a wavelength of 365 nm, so it was subjected to yellowing in the UV reliability test.

Claims (24)

A photocurable adhesive sheet laminate, which has a structure in which a photocurable adhesive sheet and a front panel used in an image display device are laminated; the photocurable adhesive sheet includes the following (1) to (3) Adhesion layer (Y) with all properties; The above front panel is not peeled off, the light transmittance at the wavelength of 365 nm is less than 10%, and the light transmittance at the wavelength of 405 nm is more than 60%: (1) The gel fraction (called "gel fraction before light irradiation X1") is in the range of 0 to 60%; (2) The light transmittance at the wavelength of 390 nm is less than 89%, and the light transmittance at the wavelength of 410 nm is more than 80%; (3) It has photohardening properties that can be hardened by irradiation with light of a wavelength of 405 nm. The photocurable adhesive sheet laminate of claim 1, wherein the photocurable property in (3) above is a photocurable property that increases the difference in gel fraction by more than 10% when irradiated with light of a wavelength of 405 nm. For example, the photocurable adhesive sheet laminate of claim 1 has photocurability as follows: when the cumulative light intensity at the irradiation wavelength of 405 nm is 3000 (mJ/cm ² ), the gel composition before light irradiation is The difference between the rate (gel fraction before light irradiation X1) and the gel fraction after light irradiation (called "gel fraction after light irradiation The gum fraction X1) becomes more than 10%. The photocurable adhesive sheet laminate according to any one of claims 1 to 3, wherein the adhesive layer (Y) contains a (meth)acrylate (co)polymer and a visible light initiator. The photocurable adhesive sheet laminate according to any one of claims 1 to 3, wherein the adhesive layer (Y) contains a silane coupling agent. The photocurable adhesive sheet laminate of claim 4, wherein the (meth)acrylate (co)polymer is formed of a base selected from the group consisting of carboxyl groups and epoxy groups, carboxyl groups and aziridinyl groups, hydroxyl groups and isocyanate. The chemical bond is a combination of any functional group among the group, amine group and isocyanate group, and carboxyl group and isocyanate group. The photocurable adhesive sheet laminate according to claim 4, wherein the (meth)acrylate (co)polymer is a graft copolymer having a macromonomer as a branch component. The photocurable adhesive sheet laminate of claim 4, wherein the visible light initiator is a hydrogen abstraction type visible light initiator. The photocurable adhesive sheet laminate of claim 8, wherein the hydrogen-abstracting visible light initiator is selected from the group consisting of methyl phenylglyoxylate and hydroxyphenylacetic acid 2-[2-side oxy-2-phenyl Any one or two of the group consisting of a mixture of acetyloxyethoxy]ethyl ester and 2-[2-hydroxyethoxy]ethyl hydroxyphenylacetate. The photocurable adhesive sheet laminate of claim 4, wherein the (meth)acrylate (co)polymer contains a linear or branched (meth)acrylic acid alkane with a carbon number of 4 to 18 in the side chain. A copolymer of base ester and hydrophilic (meth)acrylate as copolymer components. The photocurable adhesive sheet laminate according to any one of claims 1 to 3, wherein the adhesive layer (Y) contains a cross-linking agent or is formed using a cross-linking agent. The photocurable adhesive sheet laminate of claim 11, wherein the cross-linking agent is a trifunctional or higher polyfunctional (meth)acrylate that has not been modified by alkylene oxide. The photocurable adhesive sheet laminate according to claim 4, wherein the (meth)acrylate (co)polymer has an active energy ray cross-linkable structural site. The photocurable adhesive sheet laminate according to any one of claims 1 to 3, wherein the storage modulus (G') is 0.9×10 ⁵ Pa or less at a temperature of 25°C and a frequency of 1 Hz. The photo-curable adhesive sheet laminate according to any one of claims 1 to 3, wherein the storage model of the adhesive layer (Y) after irradiating light with a cumulative light intensity of 3000 (mJ/cm ² ) at a wavelength of 405 nm The number (G') becomes 0.7×10 ⁴ Pa or more at a temperature of 120°C and a frequency of 1 Hz. The photo-curable adhesive sheet laminate according to any one of claims 1 to 3, wherein the storage model of the adhesive layer (Y) after irradiating light with a cumulative light intensity of 3000 (mJ/cm ² ) at a wavelength of 405 nm The number (G') becomes 2.0×10 ⁴ Pa or more at a temperature of 120°C and a frequency of 1 Hz. The photocurable adhesive sheet laminated body according to any one of claims 1 to 3, wherein the adhesive layer (Y) has hot melt properties that can be softened or even flowed by heating. The photo-curable adhesive sheet laminate of claim 1, wherein the photo-curable adhesive sheet is composed of a single layer or a multi-layer structure of two or more layers, and the adhesive layer (Y) on the side surface of the front panel of the single layer or multi-layer layer has The photohardenability is as follows: when the gel fraction (referred to as "gel fraction before light irradiation The difference in gel fraction increases by more than 10%. The photocurable adhesive sheet laminate of claim 1, wherein the adhesive layer (Y) of the photocurable adhesive sheet has photocurable properties as follows: from the outside of the front panel at an irradiation wavelength of the front panel. When the cumulative light intensity at 405 nm is 3000 (mJ/cm ² ), the gel fraction before light irradiation (gel fraction before light irradiation The difference between the gel fraction after irradiation The photo-curable adhesive sheet laminate of claim 1, wherein when light with a cumulative light intensity of 3000 (mJ/cm ² ) at 405 nm is irradiated from the outside of the front panel through the front panel, the light after the light irradiation The storage modulus (G') of the adhesive layer (Y) in this photocurable adhesive sheet is 0.7×10 ⁴ Pa or more at a temperature of 120° C. and a frequency of 1 Hz. The photo-curable adhesive sheet laminate of claim 1, wherein when light with a cumulative light intensity of 3000 (mJ/cm ² ) at 405 nm is irradiated from the outside of the front panel through the front panel, the light after the light irradiation The storage modulus (G') of the adhesive layer (Y) in this photocurable adhesive sheet becomes 2.0×10 ⁴ Pa or more at a temperature of 120°C and a frequency of 1 Hz. The photocurable adhesive sheet laminate according to claim 1, wherein the front panel is used for a vehicle-mounted image display device. A method for manufacturing a photocurable adhesive sheet laminated body, characterized in that it is the method for manufacturing a photocurable adhesive sheet laminated body according to any one of claims 1 to 22, and The above-mentioned photocurable adhesive sheet is produced using a resin composition containing a (meth)acrylate (co)polymer and a visible light initiator, and the photocurable adhesive sheet is laminated on the above-mentioned front panel. A method for manufacturing an image display panel laminate, characterized in that it includes a photocurable adhesive sheet laminate having a photocurable adhesive sheet according to any one of claims 1 to 22 and an image display panel (P) A method of manufacturing an image display panel laminate composed of lamination, and The above-mentioned front panel and image display panel (P) are laminated via the above-mentioned photocurable adhesive sheet, Light with a wavelength of 405 nm is irradiated from the outside of the front panel through the front panel to harden the adhesive layer (Y) of the photocurable adhesive sheet, thereby bonding the front panel and the image display panel (P).