TW201920565A - Photocurable pressure-sensitive adhesive sheet, photocurable pressure-sensitive adhesive sheet laminate, production method for photocurable pressure-sensitive adhesive sheet laminate, and production method for image display panel laminate - Google Patents

Abstract

The present invention relates to a pressure-sensitive adhesive sheet for use in laminating a resin member, the pressure-sensitive adhesive sheet being photocurable and exhibiting both surface conformance properties and anti-blistering properties. Proposed is a photocurable pressure-sensitive adhesive sheet for use in laminating a resin member (X) which has a light transmittance of 10% or less at a wavelength of 365 nm and a light transmittance of 60% or greater at a wavelength of 405 nm, characterized by including a pressure-sensitive adhesive layer (Y) having all of the following properties (1) to (3): (1) a gel content in the range of 0-60%; (2) a light transmittance of 89% or less at a wavelength of 390 nm and a light transmittance of 80% or greater at a wavelength of 410 nm; and (3) photocuring properties such that curing occurs upon irradiation with light having a wavelength of 405 nm.

Description

Photocurable adhesive sheet, photocurable adhesive sheet laminate, method for producing photocurable adhesive sheet laminate, and method for producing image display panel laminate

The present invention relates to a light-curable adhesive sheet, which is an adhesive sheet for bonding a resin member having ultraviolet cut-off property that does not transmit ultraviolet rays, and has a property of curing by irradiating light (referred to as "light Sclerosis ").

In recent years, in order to improve the visibility of image display devices, the following operations have been performed: Filling image display panels and arrangements such as liquid crystal displays (LCD), plasma displays (PDP), and electroluminescence displays (ELD) with an adhesive The gap between the protective panel or the touch panel member on the front side (viewing side) of the panel, thereby suppressing the reflection of the incident light or the outgoing light from the display image at the air layer interface.

As such a method for filling a space between constituent members of an image display device with an adhesive, a liquid adhesive resin composition containing a UV-curable resin is filled in the space, and then it is irradiated with ultraviolet rays to harden it. Method (Patent Document 1).

There is also known a method of filling a space between constituent members for an image display device with an adhesive sheet. For example, Patent Document 2 discloses a method in which an adhesive sheet that is crosslinked by ultraviolet rays at a time is bonded to a constituent member of an image display device, and then the adhesive sheet is subjected to ultraviolet rays through the constituent member of the image display device. Irradiate to harden it twice.

In Patent Document 3, when an image display device having a stepped portion is bonded to a bonding surface with a transparent double-sided adhesive sheet interposed therebetween, the stepped portion can be filled to each corner, and A new transparent double-sided adhesive sheet that can alleviate the strain generated in the adhesive sheet and maintain the foaming resistance under high temperature or high humidity environment without impairing the handleability, revealing the following B-stage A transparent double-sided adhesive sheet in a state containing one or more (meth) acrylate (co) polymers, a Mohr absorption coefficient of a wavelength of 365 nm of 10 or more and a Mohr absorption coefficient of a wavelength of 405 nm of 0.1 or less Ultraviolet polymerization initiator (A) and visible light polymerization initiator (B) with a Molar absorption coefficient of 10 or more at a wavelength of 405 nm, and a dynamic storage modulus (E ') of 60 ° C obtained by a stretching method The value (E '/ G') of the dynamic storage modulus (G ') at 60 ° C divided by the shear method is 10 or more. [Prior Art Literature] [Patent Literature]

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

[Problems to be solved by the invention]

When the photocurable adhesive sheet is used to attach two image display device constituent members as described above, the two image display device constituent members can be attached once through the adhesive sheet, and then An image display device constituting member is irradiated with ultraviolet rays, and the image display device constituting member causes the adhesive sheet to be cured by ultraviolet rays to perform secondary adhesion. With this method, it is possible to perform sub-adhesion while filling the unevenness of the adhered surface, and finally to harden it with ultraviolet rays to further improve the reliability. Therefore, it can take into account the attached components (also known as " "Adhesive member") "step difference absorption" when the adhered surface has unevenness, and "foaming resistance" after bonding.

For example, in a vehicle-mounted image display device or the like, a resin front panel is used to prevent scattering of glass, and a resin member such as a conductive member or a polarizing plate may be disposed on the inside thereof. In this case, it is necessary to prevent the front panel or resin members such as conductive members or polarizers disposed on the inner side of the panel from deteriorating due to ultraviolet exposure. Therefore, perform the following operations: In the resin members exposed to the ultraviolet side Blend ultraviolet absorbers to make them absorb ultraviolet rays. However, in this case, it is not possible to irradiate ultraviolet rays from the outside of the constituent elements of the image display device as described above, and the adhesive sheet is cured by the ultraviolet rays of the constituent elements of the image display device. Therefore, when bonding a resin-made front panel, a non-light-curing adhesive sheet that has sufficiently cured to the extent that it has resistance to foaming and does not have light-curability has to be used. However, this non-light-curing adhesive sheet is not necessarily satisfactory in terms of step absorptivity.

The present invention provides bonding with a resin member having ultraviolet cut-off property that does not transmit ultraviolet rays, and can also take into account the step absorption when the adhered surface of the bonding member has unevenness, and the foam resistance after bonding is reliable. Sexual novel adhesive sheet. [Technical means to solve the problem]

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

The present invention also provides a photocurable adhesive sheet laminate, which includes the 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. The resin member (X) is laminated. [Effect of the invention]

The gel fraction of the photo-curable adhesive sheet before the photo-hardening of the present invention is 0 to 60%. Therefore, it is possible to obtain step absorptivity such as unevenness in the land to be adhered, and on the other hand, The light transmittance at a wavelength of 390 nm is 89% or less, and has a light-hardening property that is hardened by irradiating light at a wavelength of 405 nm. Therefore, even if the resin member (X) to be bonded has a light transmittance at a wavelength of 365 nm, It is 10% or less, and the light transmittance at a wavelength of 405 nm is 60% or more. It can also be hardened by irradiating light containing a wavelength of 405 nm, thereby improving cohesion and obtaining foaming reliability after bonding. . In addition, the light-curable adhesive sheet of the present invention has a light transmittance of more than 80% at a wavelength of 410 nm, so that the following effects can be obtained: a sufficiently low level required for bonding optical components requiring transparency Yellowness (YI).

The photo-curable adhesive sheet laminate according to the present invention can obtain the step absorbency as described above. On the other hand, the photo-curable adhesive sheet has an adhesive layer (Y) provided in the resin member (X). When the resin member (X) is irradiated with light having a wavelength of 405 nm on the outside, the difference in gel fraction is improved by more than 10% of the light-hardening property. Therefore, the resin member (X) is separated from the outside by the resin member (X). ) Irradiating light with a wavelength of 405 nm can harden the adhesive layer (Y), and it can also improve cohesion and obtain foaming reliability after bonding.

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") which is an example of an embodiment of the present invention is a photocurable adhesive sheet including an adhesive layer (Y) having specific characteristics.

The present adhesive sheet is a light-curable adhesive sheet that is cured by irradiating light. At this time, the present adhesive sheet may be hardened to a state where there is room for light hardening (also referred to as "temporary hardening"), or it may be unhardened and hardened with light hardening (referred to as "unhardened" ")By. If the adhesive sheet is temporarily hardened or uncured, the adhesive sheet can be light cured (also referred to as "formal hardening") after the adhesive sheet is attached to the adherend, and the result is It improves cohesion and improves adhesion.

As a preferable form of the present adhesive sheet which is temporarily hardened or not hardened and has the property that it can be hardened formally, that is, light-hardenable by hardening by irradiating light with a wavelength of 405 nm, the following may be included: 1) The adhesive sheet of the adhesive layer (Y) shown in (3).

(1) The adhesive layer (Y) is temporarily hardened until the gel fraction becomes 60% or less, and the visible light initiator (c) can be adhered to formally hardened by containing the visible light initiator (c) described below. Floor. (2) The adhesive layer (Y) is temporarily hardened to a gel fraction of 60% or less by the hydrogen-abstracting visible light initiator (c-2) of the visible light initiator (c) described below. The visible light initiator (c-2) was subjected to the hardening of the adhesive layer. (3) The adhesive layer (Y) is an adhesive layer that maintains the shape of the sheet in an unhardened state, and can formally harden the visible light initiator (c) by containing the visible light initiator (c) described below. .

As a method for forming the adhesive layer (Y) in the above (1), for example, the following method can be mentioned: a (meth) acrylate (co) polymer containing a visible light initiator (c) and having a functional group (i) ( a) Compounds having a functional group (ii) that reacts with the functional group (i), other photopolymerizable compounds with carbon-carbon double bonds (especially polyfunctional monomers), and other cross-linking agents (b ). Further, if necessary, 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 is reacted with the functional group (ii) in the compound to form a chemical bond to be hardened (crosslinked) to form an adhesive layer ( Y). By forming the adhesive layer (Y) as described above, the visible light initiator (c) can be made active in the adhesive layer (Y).

Examples of the combination 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 isocyanate group, an amine group and an isocyanate group, and a carboxyl group and an isocyanate group. Cyano, 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 (meth) acrylate copolymer (a) has a hydroxyl group (a monomer containing a hydroxyl group described below) is used, and the compound has an isocyanate group is a particularly preferable example.

The compound having the functional group (ii) may further have a radical polymerizable functional group such as a (meth) acrylfluorenyl group. Thereby, a (meth) acrylate (co) polymer which maintains the (meth) acrylate (co) polymer by the said radically polymerizable functional group, specifically, the (meth) acrylate which has the following active energy ray crosslinkable structure part can be formed. Photocuring (crosslinking) adhesive layer (Y) of the copolymer. More specifically, when the (meth) acrylate (co) polymer (a) has a hydroxyl group (using a hydroxyl-containing monomer described below) and the compound has a (meth) acrylfluorenyl group (isocyanate Acid 2-propenyloxyethyl, 2-methacryloxyethyl isocyanate, and 1,1- (bispropenyloxymethyl) ethyl isocyanate are particularly preferred examples. As described above, by using a cross-linking reaction of the (meth) acrylate (co) polymers due to the radical polymerizable functional group, it is possible to efficiently and easily without using a crosslinking agent (b). It is better because it improves cohesion after photo-hardening (cross-linking) and has excellent reliability.

Furthermore, preferred aspects of the acrylate (co) polymer (a), or the crosslinking agent (b), the visible light initiator (c), and the silane coupling agent (d), which are more preferable than the above, are preferable. Etc. as described below.

As a method for forming the adhesive layer (Y) in the above (2), for example, a method using the following hydrogen-abstracting visible light initiator (c-2) as the visible light initiator (c) is mentioned. Even if the hydrogen-abstracting initiator is excited once, the unreacted ones in the initiator will return to the base state, so it can be reused as a visible light initiator. As described above, by using a visible light initiator of a hydrogen abstraction type, the visible light hardening (crosslinking) property of the visible light initiator can be maintained even after temporary hardening by visible light irradiation. In addition, aspects other than the above and a preferable aspect of the visible light initiator (c-2) are described below.

Examples of the method for forming the adhesive layer (Y) in the above (3) include a method 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 can be mentioned. By using such a macromonomer, it is possible to maintain a state in which the branch components are attracted to each other and physically crosslinked into a composition (an example of the present resin composition described later) at room temperature. Therefore, it is possible to form an adhesive layer (Y) that can maintain the sheet shape in the uncured (crosslinked) state and contains a visible light initiator (c). In addition, the aspect other than the above and the preferable aspect of the graft copolymer which has a macromonomer as a branch component etc. are as follows.

This adhesive sheet is preferably used for bonding a resin member (X) described later.

The adhesive sheet may be a single-layer structure of the above-mentioned adhesive layer (Y), or may be a multilayer structure of two or more layers having the above-mentioned adhesive layer (Y). In the case of multiple layers, at least the outermost layer may be 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 said adhesive layer (Y) has all the characteristics of the following (1)-(3). (1) The gel fraction in the normal state, that is, the state before light irradiation (referred to as "gel fraction X1 before light irradiation") is in the range of 0 to 60%. (2) The light transmittance at a wavelength of 390 nm is 89% or less, and the light transmittance at a wavelength of 410 nm is more than 80%. (3) It has photohardenability which is hardened by irradiation with light having a wavelength of 405 nm.

If the adhesive layer (Y) has a hot-melt property that softens or even flows by heating, when there is a step such as unevenness on the adhered surface of the bonded member, the adhesive can be filled more easily to the step Each corner is more preferable because it can further improve the step absorptivity. From this viewpoint, it is preferable that the adhesive layer (Y) is the adhesive layer (Y) of the above (3).

(Gel fraction) It is preferable that the gel fraction (gel fraction X1 before light irradiation) 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 viewpoint that there are enough uncrosslinked components (in a temporarily hardened state or uncured state) having room for hardening by light irradiation. (Hardened state). Because of this, it is soft, and when it is fully hardened, the "gel fraction X2 after light irradiation-gel fraction X1 before light irradiation" 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%, and among them, it is more preferably 55% or less, and more preferably 50% or less.

In order to adjust the gel fraction of the adhesive layer (Y) (gel fraction X1 before light irradiation) to the above-mentioned range, the residual catalyst is sufficient during polymerization of the present resin composition described later and during processing of the adhesive sheet. It can be removed, or polymerization inhibitors, antioxidants, etc. can be used to prevent undesired hardening (crosslinking) reaction due to heat, light, etc. before the actual hardening; In the case of performing temporary hardening, it is sufficient if the cumulative light amount of light irradiated for temporary hardening is sufficiently small, and the amount of uncrosslinked components is sufficient. It is not limited to this method.

Furthermore, it is preferable that the adhesive layer (Y) has a light-hardening property that is hardened by irradiating light having a wavelength of 405 nm. The degree of the light-hardening property is, for example, preferably provided on the outside of the resin member (X). When the resin member (X) is irradiated with light having a wavelength of 405 nm, the difference in gel fraction is increased by more than 10%, preferably 15% or more, more preferably 20% or more, and even more preferably 30% or more. Among them, the photo-hardening property is more preferably 50% or more. In addition, the "light irradiated with a wavelength of 405 nm" means light irradiated with the following light sensitivity, that is, a light having a wavelength of 405 nm as a photometric peak measured with an ultraviolet light meter and a periphery extending to a wavelength range of 320 to 470 nm. Light sensitivity.

Among them, it is preferable that the adhesive layer (Y) has a photo-hardening property: from the outside of the resin member (X), a cumulative light amount at a wavelength of 405 nm is 3,000 (mJ / cm) through a resin member (X), for example. ² ) In the case of light, the difference between the gel fraction before light irradiation (gel fraction X1 before light irradiation) and the gel fraction after light irradiation (referred to as "gel fraction X2 after light irradiation") ( Gel fraction X2 after light irradiation-gel fraction X1) before light irradiation becomes 10% or more. Therefore, it is preferable to have photohardenability. For example, in the case where the gel fraction X1 is 40% before light irradiation, adhesion after irradiation with light with a cumulative light amount of 3000 (mJ / cm ² ) at a wavelength of 405 nm is performed. The gel fraction (referred to as "gel fraction X2 after light irradiation") of the layer (Y) is 50% or more. If the gel fraction difference of the adhesive layer (Y) before and after photo-hardening is 10% or more, it will have high cohesion even in severe high-temperature and high-humidity environments, and it will improve foaming reliability, so it is preferred. Therefore, it is preferable that the gel fraction difference of the adhesive layer (Y) before and after the light irradiation is 10% or more, of which 15% or more is more preferable, 20% or more is more preferable, and 30% is more preferable. Above, especially 50% is more preferable. In order to adjust the gel fraction difference of the adhesive layer (Y) before and after the light irradiation as described above, absorption of a photoinitiator may exist at a wavelength of 405 nm. It is not limited to this method.

In addition, the "cumulative light amount at a wavelength of 405 nm" is the total amount of irradiation energy per unit area, and it refers to the use of ultraviolet light intensity meter "UIT-250" in light irradiated by a high-pressure mercury lamp or the like. (Manufactured by Oxtail Electric Co., Ltd.) and the total amount of light irradiation energy measured by the receiver "UVD-C405" (manufactured by Oxtail Electric Co., Ltd.), which refers to the photosensitivity characteristics of the photoreceptor (with a sensitivity of 405 nm Peak, the light sensitivity around the wavelength range extending from 320 to 470 nm) corresponds to the cumulative amount of light in the wavelength region. More specifically, it means the cumulative amount of light obtained in accordance with the method described in the examples.

(Light transmittance) The light transmittance of the adhesive layer (Y) at a wavelength of 390 nm is preferably 89% or less, and the light transmittance at a wavelength of 410 nm is 80% or more. Regarding an adhesive formulation having a light initiator having an absorption light initiator in the ultraviolet to visible light region before and after a wavelength of 400 nm, the greater the light absorption of the light initiator, the greater the light transmittance at the wavelength of 390 nm derived from the absorption. The lower the photosensitivity, the harder it becomes. On the other hand, if the light transmittance at a wavelength of 410 nm is not high to a certain degree or more, the adhesive layer (Y) is colored yellow and it becomes difficult to use it in an optical member.

As the above standard, if the light transmittance at a wavelength of 390 nm is 89% or less, the adhesive layer (Y) can ensure sufficient visible light hardening, so it is preferable; if the light transmittance at a wavelength of 410 nm is more than 80% , It can achieve a sufficiently low yellowness (YI) required for bonding optical components that require transparency, so it is preferred. Therefore, the light transmittance of the adhesive layer (Y) at a wavelength of 390 nm is preferably 89% or less, and more preferably 88% or less. The light transmittance at a wavelength of 410 nm is preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more. In order to set the light transmittance of the adhesive layer (Y) as described above, it is only necessary to use one of the following absorption peak characteristics in an initiator having absorption in visible light: the periphery of the absorption peak sufficiently reaches 390 nm. The absorption peak becomes smaller at 410 nm. 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 lower at a temperature of 25 ° C. and a frequency of 1 Hz. By having such viscoelastic properties, the present adhesive sheet can obtain particularly excellent step absorbency required for filling the unevenness such as unevenness of the adhered surface. From this viewpoint, 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 more preferably 0.8 × 10 ⁵ Pa or less.

The storage modulus (G ') of the adhesive layer (Y) at a wavelength of 405 nm and a cumulative light amount of 3000 (mJ / cm ² ) is preferably 0.7 × at a temperature of 120 ° C. and a frequency of 1 Hz. 10 ⁴ Pa or more. If the storage modulus (G ') of the adhesive layer (Y) after photo-hardening is in the above range, it is preferable in the following aspects: The laminated body of the adhesive layer (Y) and the resin member (X) is supplied to a high temperature test, and the high temperature is high. In the wet test and the like, foaming of the adhesive layer (Y) due to the outgassing component 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 higher at a temperature of 120 ° C. and a frequency of 1 Hz, and more preferably 1.0 × 10 ⁴ Pa or more, and more preferably 2.0 × 10 ⁴ Pa or more.

Here, in an image display device or the like having a touch panel function, as a touch sensor disposed on the back side of the front panel / adhesive layer, a glass sensor and a film sensor are respectively used according to the module design. Sensors, polarizing plate glass (surface-mounted or embedded-type with sensors incorporated inside), etc., due to the structure of the sensor components, the easiness of defects in environmental tests is different. The result of the experimental research in the invention of the present application is the storage of the adhesive layer (Y) when the adhesive layer (Y) is bonded and used with the structure of the resin member (X) / adhesive layer (Y) / glass sensor. The preferred range of the modulus (G ') is as shown in the above range. On the other hand, when the resin member (X) / adhesive layer (Y) / membrane sensor is used in a bonded manner, the film feels The detector is usually thin with a thickness of less than 100 μm and has a small hardness. Because the reliability improvement effect of the silane coupling agent is lower than the reliability improvement effect of the glass material, it is easier in the hot and humid environment test than the case of the glass sensor. Foaming occurs, and a higher level of storage modulus (G ') becomes necessary.

Therefore, as this point of view, that is, the structure of the resin member (X) / adhesive layer (Y) / film sensor is used to bond the adhesive layer (Y) after light curing when the adhesive layer (Y) is used. The storage modulus (G '), that is, the preferable range of the storage modulus (G') of the adhesive layer (Y) when the cumulative light amount at a wavelength of 405 nm is 3000 (mJ / cm ² ) is 2.0 × 10 ⁴ Pa or more, more preferably 5.0 × 10 ⁴ Pa or more, and even more preferably 8.0 × 10 ⁴ Pa or more.

(Composition of Adhesive Layer (Y)) The adhesive layer (Y) may include a (meth) acrylate (co) polymer (a) and a visible light initiator (c), and a cross-linking agent (b) if necessary. It is formed by the silane coupling agent (d) which is further contained as needed, and the adhesive composition (referred to as "this resin composition") of another material which is further contained.

[(Meth) acrylate (co) polymer (a)] The above (meth) acrylate (co) polymer (a) is preferably photocurable.

In addition, the "(meth) acryl group" means an acrylic group and a methacryl group, and the "(meth) acryl group" means an acryl group and a methacryl group, and the "(meth) "Acrylate" includes the meanings of acrylate and methacrylate, respectively. The term "(co) polymer" includes the meaning of polymers and copolymers. In addition, the "sheet" conceptually includes a sheet, a film, and a tape.

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

More specifically, examples of the (meth) acrylate (co) polymer (a) include an alkyl (meth) acrylate and a monomer component copolymerizable therewith, for example, including any one selected from the following monomers Copolymer of monomer components of one or more monomers: (a) a carboxyl group-containing monomer (hereinafter also referred to as "copolymerizable monomer A"), (b) a hydroxyl group-containing monomer (hereinafter also referred to as "copolymerization" Monomer B "), (c) an amine group-containing monomer (hereinafter also referred to as" copolymerizable monomer C "), (d) an epoxy group-containing monomer (hereinafter also referred to as" copolymerizable monomer D " "), (E) a amine group-containing monomer (hereinafter also referred to as" copolymerizable monomer E "), (f) a vinyl monomer (hereinafter also referred to as" copolymerizable monomer F "), (g ) (Meth) acrylate monomers with 1 to 3 carbon atoms in side chains (hereinafter also referred to as "copolymerizable monomers G") and (h) macromonomers (hereinafter also referred to as "copolymerizable monomers H" ").

The alkyl (meth) acrylate is preferably a linear or branched (meth) acrylate having 4 to 18 carbon atoms in the side chain. Examples of the linear or branched (meth) acrylic acid alkyl ester having 4 to 18 carbon atoms in the side chain include n-butyl (meth) acrylate, isobutyl (meth) acrylate, and (formyl) Base) second butyl acrylate, third butyl (meth) acrylate, amyl (meth) acrylate, isoamyl (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-butyl cyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, (meth) Undecyl acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, cetyl (meth) acrylate, (meth) Stearyl Acrylate, Isostearyl (meth) acrylate, Isopropyl (meth) acrylate, 3,5,5-Trimethylcyclohexane (meth) acrylate, Dicyclo (meth) acrylate Amyl ester, dicyclopentenyl (meth) acrylate , (Meth) acrylate, dicyclopentenyloxyethyl acrylate and the like. These may be used singly or in combination of two or more. Among the above, as the linear or branched (meth) acrylic acid alkyl ester having 4 to 18 carbon atoms, it is particularly preferable to include butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ( Any one or more of lauryl (meth) acrylate and iso (meth) acrylate.

Examples of the copolymerizable monomer A include (meth) acrylic acid, 2- (meth) acryloxyethylhexahydrophthalic acid, and 2- (meth) acryloxypropylhexadecane. Hydrophthalic acid, 2- (meth) acryloxyethyl phthalate, 2- (meth) acryloxypropyl phthalate, 2- (meth) acryloxy Ethylmaleic acid, 2- (meth) acryloxypropyl maleic acid, 2- (meth) acryloxyethyl succinic acid, 2- (meth) acryloxypropyl succinic acid Acid, butenoic 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 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (meth) acrylic acid. Hydroxyalkyl (meth) acrylates 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 aminomethyl (meth) acrylate, aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, and aminoiso (meth) acrylate. (Meth) acrylate amino alkyl esters such as propyl ester, N-alkylamino alkyl alkyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, (meth) acrylic acid N, N-dialkylamino alkyl (meth) acrylates such as N, N-dimethylaminopropyl. These may be one type or a combination of two or more types.

Examples of the copolymerizable monomer D include glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, 3,4-epoxycyclohexyl methyl (meth) acrylate, and (meth) ) 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-methylolpropane (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acryl Amidine, diacetone (meth) acrylamide, maleimide, 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 alkyl (meth) acrylates having 1 to 12 carbon atoms in the alkyl group, and functional monomers having functional groups such as a hydroxyl group, amidino group, and an alkoxyalkyl group in the molecule. Types, and polyalkylene glycol di (meth) acrylates, and vinyl ester monomers such as vinyl acetate, vinyl propionate, and vinyl laurate, and styrene, chlorostyrene, and 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. Moreover, among the above, it is preferable to select the alkyl (meth) acrylate and the said copolymerizable monomer F other than this alkyl (meth) acrylate.

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

As the macromonomer system of the copolymerizable monomer H described above, the polymer monomer having a terminal functional group and a high molecular weight skeleton component is preferably a polymer having a side chain when a (meth) acrylate copolymer is formed by polymerization. A monomer having a carbon number of 20 or more.

By using the copolymerizable monomer H, a macromonomer can be introduced as a graft component of the graft copolymer, and the (meth) acrylate copolymer can be made into a graft copolymer. For example, a (meth) acrylic acid ester copolymer (a-1) can be prepared which contains a graft copolymer having a macromonomer as a branch component. Therefore, the characteristics of the main chain and the side chain of the graft copolymer can be changed by the selection or blending ratio of the copolymerizable monomer H and other monomers.

The skeleton component of the macromonomer preferably contains an acrylate polymer or an ethylene-based polymer. Examples include straight or branched (meth) acrylic acid alkyl esters having 4 to 18 carbon atoms in the side chain, the copolymerizable monomer A, the copolymerizable monomer B, the copolymerizable monomer G, and the like. As exemplified above, these can be used alone or in combination of two or more.

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

As the above-mentioned hydrophobic (meth) acrylate, an alkyl ester (excluding methyl acrylate) which does not have a polar group is preferred, and examples thereof include n-butyl (meth) acrylate and (meth) acrylic acid. Isobutyl ester, second butyl (meth) acrylate, third butyl (meth) acrylate, amyl (meth) acrylate, isoamyl (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, third butyl cyclohexyl (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, (meth) Isopropyl acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and methyl methacrylate. Examples of the hydrophobic vinyl monomer include vinyl acetate, styrene, third butylstyrene, α-methylstyrene, vinyl toluene, and alkyl vinyl monomers.

On the other hand, as the hydrophilic (meth) acrylate monomer, a methacrylate or an ester having a polar group is preferred, and examples thereof include methyl acrylate, (meth) acrylic acid, and (meth) acrylic acid. Tetrahydrofurfuryl ester, or hydroxyl-containing (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and glyceryl (meth) acrylate , Or (meth) acrylic acid, 2- (meth) acryloxyethyl hexahydrophthalic acid, 2- (meth) acryloxypropyl hexahydrophthalic acid, 2- (formaldehyde) Propyl) acryloxyethyl phthalic acid, 2- (meth) acryloxypropyl phthalic acid, 2- (meth) acryloxyethyl maleic acid, 2- (formyl) Propyl) acryloxypropylmaleic acid, 2- (meth) acryloxyethyl succinic acid, 2- (meth) acryloxypropyl succinic acid, butenoic acid, fumaric acid, Monocarboxylic acid-containing monomers such as maleic acid, itaconic acid, monomethyl maleate, and monomethyl maleate, etc. Monocarboxylic acid-containing monomers such as maleic anhydride, itaconic anhydride, and glycidyl (meth) acrylate Esters, α-Ethyl Acrylic Epoxy group-containing monomers such as glycidyl ester, 3,4-epoxybutyl (meth) acrylate, and alkoxy polyalkylene glycols such as methoxy polyethylene glycol (meth) acrylate ( (Meth) acrylates, N, N-dimethylacrylamide, hydroxyethylacrylamide and the like.

The macromonomer as the 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 sulfonylamine group, or a thiol group. . The macromonomer is preferably one having a radical polymerizable group that can be copolymerized with other monomers. The radical polymerizable group may contain one or two or more, and particularly preferably one. When the above-mentioned macromonomer has a functional group, the functional group may also contain one or two or more, of which one is particularly preferred. In addition, it may contain either one of a radical polymerizable group and a functional group, or both. In the case where both a radical polymerizable group and a functional group are contained, a function other than any one of a functional group added to a polymer unit containing another monomer or a radical polymerizable group copolymerized with another monomer There may be two or more radical or radical polymerizable groups.

Examples of the terminal functional group of the macromonomer include a radical polymerization group such as a methacryl group, an acryl group, and a vinyl group, and also include a hydroxyl group, an isocyanate group, an epoxy group, a carboxyl group, and an amine. Functional groups such as amino, amido, and thiol. Among these, it is preferable to have a radical polymerizable group which can be copolymerized with other monomers. The radical polymerizable group may contain one or two or more, and particularly preferably one. When the macromonomer has a functional group, the functional group may also contain one or two or more, and one of them is particularly preferred. In addition, it may contain either one of a radical polymerizable group and a functional group, or both. In the case where both a radical polymerizable group and a functional group are contained, a function other than any one of a functional group added to a polymer unit containing another monomer or a radical polymerizable group copolymerized with another monomer There may be two or more radical or radical polymerizable groups.

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 even more preferably 1,000 or 7,000 or less.

The glass transition temperature (Tg) of the macromonomer is preferably higher than the glass transition temperature of the copolymer component constituting the (meth) acrylate (co) polymer (a-1). Specifically, the glass transition temperature (Tg) of the macromonomer has an influence on the heating and melting temperature (hot melting temperature) of the adhesive sheet, so it is preferably 30 ° C to 120 ° C, and more preferably 40 ° C or above or 110 ° C. Hereinafter, it is more preferable that it is 50 degreeC or more and 100 degreeC or less.

If the macromonomer is such a glass transition temperature (Tg), it can maintain excellent processability or storage stability by adjusting the molecular weight, and it can be adjusted to cause hot melting around 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 that the branch components are attracted to each other and to physically crosslink the adhesive composition at a room temperature state, and to obtain the fluidity by dissolving the physical crosslinking by heating to a moderate temperature, it is preferred Adjust the molecular weight or content of the macromonomer.

From this viewpoint, the (meth) acrylate copolymer (a) preferably contains a macromonomer at a ratio of 5 to 30% by mass, and more preferably 6 to 25% by mass or more. The macromonomer is contained in the ratio, and it is more preferable that the macromonomer is contained in a ratio of 8% by mass or more or 20% by mass or less. The number average molecular weight of the macromonomer is preferably 500 to 100,000, more preferably less than 8,000, more preferably 800 or less or 7500, and even more preferably 1,000 or less or 7,000.

The (meth) acrylate (co) polymer (a) preferably has an active energy ray crosslinkable structural site. The above-mentioned active energy ray crosslinkable structure may be, for example, a part of the (meth) acrylate copolymer (a) or the (meth) acrylate copolymer in the presence of a visible light initiator (c) described later. (a) Structural parts other than the hardening component react to form a crosslinked structure.

Examples of the active energy ray crosslinkable structural site include a structure having a radical polymerizable functional group. The radical polymerizable functional group is a functional group having an unsaturated double bond such as a (meth) acrylfluorenyl group or a vinyl group. Radical polymerizable functional group having a carbon-carbon double bond such as a radical. Since the polymer chain of the (meth) acrylate (co) polymer (a) has an unsaturated double bond, the polymer chains can be directly polymerized with each other even when the crosslinking agent is not contained, The storage modulus (G ') is increased to a higher level. In addition, when performing active energy ray irradiation, any light source including light having a wavelength of 405 nm may be used. In consideration of the curing speed, the availability of the irradiation device, and the price, visible light LED light sources, high-pressure mercury lamps, and the like can be used.

In order to introduce a structure containing a radically polymerizable functional group having a carbon-carbon double bond such as a functional group having an unsaturated double bond, for example, a functional group is copolymerized with the above (meth) acrylate (co) polymer (a) in advance. And then a monomer having a carbon-carbon double bond such as a functional group capable of reacting with the functional group (e.g., 2-isocyanatoethyl (meth) acrylate, etc.) and an unsaturated double bond The compound may react with the carbon-carbon double bond while maintaining its hardening property.

Among them, the (meth) acrylate copolymer (a) is preferably a unit containing a (meth) acrylate monomer having a linear energy alkyl group having an active energy ray crosslinkable structure portion and having 10 to 24 carbon atoms. Body (meth) acrylate (co) polymer (a-2). Examples of such a (meth) acrylate (co) polymer (a-2) include decyl (meth) acrylate (the carbon number of the alkyl group is 10), and lauryl (meth) acrylate (carbon Number 12), tridecyl (meth) acrylate (carbon number 13), cetyl (meth) acrylate (carbon number 16), stearyl (meth) acrylate (carbon number 18), behenyl (meth) acrylate (carbon number 22), and the like. These can be used alone or in combination of two or more.

The linear (meth) acrylic acid alkyl ester monomer (a) having an alkyl group having 10 to 24 carbon atoms is considered from the viewpoint of lowering the dielectric constant and reducing the glass transition temperature of the acrylic resin. Preferably, an alkyl methacrylate is used, especially those having an alkyl group having 12 to 20 carbon atoms, and most preferably stearyl methacrylate, lauryl methacrylate, and tridecyl methacrylate ester.

The content of the (meth) acrylic acid alkyl ester monomer (a) having a linear alkyl group having 10 to 24 carbon atoms is 50 to 94% by weight based on the entire (co) polymerization component, and preferably 60 83% by weight, particularly preferably 70 to 80% by weight. By setting it as the said range, there exists no possibility that a dielectric constant will become high and the thermal stability of resin will fall.

[Crosslinking agent (b)] The crosslinking agent (b) is preferably a crosslinking agent having at least a double bond crosslinking. For example, it has a material selected from the group consisting of (meth) acrylfluorenyl, epoxy, isocyano, carboxyl, hydroxyl, carbodiimide, oxazoline, aziridinyl, vinyl, amine, The crosslinking agent of at least one kind of crosslinkable functional group of an imino group and a sulfonyl group may be used alone or in combination of two or more kinds. In particular, by using two or more kinds of cross-linking agents in combination, a higher storage modulus (G ') can be achieved even when the total amount of the compounding is the same as compared with the case of using them individually. Therefore, it is more preferable to use a combination of two or more crosslinking agents (b). Moreover, the aspect which chemically bonds the crosslinking agent (b) and a (meth) acrylate (co) polymer (a) is included.

Among them, it is preferable to use a photopolymerizable compound having a carbon-carbon double bond, particularly a polyfunctional (meth) acrylate. Here, the polyfunctional means one having two or more crosslinkable functional groups. Furthermore, if necessary, it may have 3 or more and 4 or more crosslinkable functional groups. The crosslinkable functional group may be protected by a protective group capable of being deprotected.

Examples of the polyfunctional (meth) acrylate include 1,4-butanediol di (meth) acrylate, glycerol di (meth) acrylate, and neopentyl glycol di (meth) acrylate , Glycerol glycidyl ether di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tricyclodecane dimethyl 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 tris (2-hydroxyethyl) isocyanurate tris (meth) acrylate, pentaerythritol tris (meth) acrylate, propoxylated pentaerythritol tris (meth) acrylate, Ethoxylated pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, propoxylated pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, polyethylene glycol di (meth) acrylate, tris (propyleneoxyethyl) isocyanurate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (methyl) Base) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, hydroxypentopenate neopentyl glycol ester Ε-caprolactone adducts of di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, di- In addition to UV-curable polyfunctional (meth) acrylic monomers such as trimethylolpropane tetra (meth) acrylate, polyester (meth) acrylate, (meth) acrylic epoxy can also be mentioned. Polyfunctional (meth) acrylic oligomers such as esters, (meth) acrylate urethanes, and polyether (meth) acrylates. These may be used singly 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 be a structure having a short distance between crosslinking points and a dense crosslinking density in the formed crosslinking structure, such as It is preferably a trifunctional or higher polyfunctional (meth) acrylate which is not modified with alkylene oxide, and is preferably selected from pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, trimethylol Polyfunctional (meth) acrylate (b-1) in the group consisting of propyl propane tri (meth) acrylate and di-trimethylolpropane tetra (meth) acrylate. The polyfunctional (meth) acrylate (b-1) may be used singly or in combination (as a mixture), and two or more kinds may be used.

When the above-mentioned polyfunctional (meth) acrylate (b-1) is used as a cross-linking agent, the (meth) acrylate (a) preferably contains hydrophilicity from the viewpoint of compatibility. A copolymer of a monomer component having a monomer as a polar component. Since this (meth) acrylate (a) contains a polar component, its compatibility with the above-mentioned multifunctional (meth) acrylate (b-1) becomes good, and it becomes easily mixed during mixing, and it is not It becomes difficult to cause phase separation when stored for a long time in a connected state, and there is no possibility that the haze value will increase.

Specifically, as the (meth) acrylate (co) polymer (a), copolymerization of the (meth) acrylic acid alkyl ester with the following monomer components as a copolymerizable monomer copolymerizable therewith is preferred. The monomer component is a monomer component suitable for selecting a hydrophilic monomer from the copolymerizable monomers A to G, and contains the above-mentioned hydrophilic (meth) acrylate, or at least one selected from copolymerizable monomers. G of methyl (meth) acrylate. Furthermore, the (meth) acrylate (co) polymer (a) is particularly preferably a total amount of hydrophilic monomers containing at least methyl (meth) acrylate and (selected from copolymerizable monomers A to G). A copolymer of 10 parts by mass or more of a monomer component in the entire (meth) acrylate (co) polymer (a).

The (meth) acrylate (co) polymer (a-1) is preferably a straight or branched chain (4 to 18 carbon atoms) containing the side chain as a skeleton component (dry component). A copolymer of an alkyl acrylate and a monomer component of the above-mentioned hydrophilic monomer which is a copolymerizable monomer copolymerizable therewith.

The content of the crosslinking 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 further more preferably a ratio of 5 parts by mass or more and 30 parts by mass or less.

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

The visible light initiator (c) preferably has an absorbance 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 more. By setting the absorption coefficient at a wavelength of 405 nm to be 10 mL / (g · / cm) or more, hardening (cross-linking) of 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, and more preferably 1 × 10 ³ mL / (g · / cm) or less. Furthermore, it can be used in combination with a light initiator having a wavelength of 405 nm and an absorption coefficient of less than 10 mL / (g · / cm).

Photoinitiators are roughly classified into two types according to the mechanism of free radical generation, which are roughly divided into: cleavable photoinitiators, whose single bonds can be cleaved and decomposed to generate free radicals; and hydrogen abstraction photoinitiators , The photoexcited initiator and the hydrogen donor in the system can form an excitation complex, thereby causing hydrogen transfer from the hydrogen donor.

Among these, the cleavage type photoinitiator is decomposed into other compounds when free radicals are generated by light irradiation, and once excited, it does not have a function as a reaction initiator. Therefore, it does not remain as an active species in the adhesive after the crosslinking reaction is completed, and there is no possibility that the adhesive may cause undesired light degradation, etc., and is therefore preferred. Moreover, regarding the coloring peculiar to a photoinitiator, when the cleavable visible light initiator (c-1) which irradiates and hardens by visible light was added to the adhesive previously, there exists a possibility of coloring. Therefore, as the visible light initiator (c), it is preferable to appropriately select a reaction decomposed product which does not absorb color in the visible light region and decolorizes. On the other hand, a hydrogen-abstracting photoinitiator not only maintains its function as a reaction initiator even if it is irradiated with a plurality of times of light, but it is not as good as a radical generating reaction by irradiating active energy rays such as ultraviolet rays. A decomposed product is generated like a cleavage type photoinitiator, and therefore it is difficult to become a volatile component after completion of the reaction. This is useful in reducing damage to an adherend. Therefore, a hydrogen abstraction type visible light polymerization initiator (c-2) which is excited by visible light and starts polymerization is particularly preferred.

Examples of the cleavable visible light initiator (c-1) include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1- (4- (2-hydroxyethoxy) phenyl) -2-hydroxy-2-methyl-1-propane- 1-keto, 2-hydroxy-1- [4- {4- (2-hydroxy-2-methyl-propionyl) benzyl} phenyl] -2-methyl-propane-1-one, oligomer (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) acetone), methyl phenylglyoxylate, 2-benzyl-2-dimethylamino-1 -(4-Phenylphenyl) butane-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-olinylpropane-1-one, 2- (dimethylform Amine) -2-[(4-methylphenyl) methyl) -1- [4- (4-lineyl) phenyl] -1-butanone, bis (2,4,6-trimethyl (Benzylidene) -phenylphosphine oxide, 2,4,6-trimethylbenzylidene diphenylphosphine oxide, (2,4,6-trimethylbenzylidene) ethoxyphenyl Phosphine oxide or derivatives thereof. Among these methods, bis (2,4,6-trimethylbenzyl) -phenylphosphine oxide and 2,4,6-trimethyl are preferred as a method for decolorization after reaction. Benzamyl diphenylphosphine oxide, (2,4,6-trimethylbenzyl) ethoxyphenylphosphine oxide, bis (2,6-dimethoxybenzyl) 2, Fluorenylphosphine oxide based photoinitiators such as 4,4-trimethylpentylphosphine oxide.

Examples of the hydrogen-abstracting visible light initiator (c-2) include bis (2-phenyl-2-sideoxyacetic acid) oxybis (ethylene) ethoxylate, methyl phenylglyoxylate, and hydroxyphenylacetic acid. Mixture of 2- [2-Pentoxy-2-phenylethoxyethoxy] ethyl ester and 2- [2-hydroxyethoxy] ethyl hydroxyphenylacetate, 9-oxysulfur , 2-chloro-9-oxysulfur 3-methyl-9-oxysulfur 2,4-dimethyl-9-oxysulfur , Anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, camphorquinone or derivatives thereof, and the like. Among these, it is preferably selected from the group consisting of methyl phenylglyoxylate, 2- [2- pendantoxy-2-phenylacetamidooxyethoxy] ethyl hydroxyphenylacetate, and 2- [2- Either or both of the groups consisting of a mixture of hydroxyethoxy] ethyl esters.

The visible light initiator (c) is not limited to the substances listed above. Any of the visible light initiators (c) listed above or a derivative thereof may be used, or two or more of them may be used in combination. In addition, in addition to the visible light initiator (c), those that generate only radicals by irradiating other light such as ultraviolet rays may be mixed.

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

[Silane coupling agent (d)] The silane coupling agent (d) can improve the adhesion, and among them, the adhesion to the glass material can be improved. 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, and the like, 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, and the like. Among them, in the adhesive layer (Y), γ-glycidoxypropyltrimethoxysilane or γ-methacryloxy is preferably used from the viewpoints of good adhesion and less discoloration such as yellowing. Propyltrimethoxysilane. These silane coupling agents may be used alone or in combination of two or more.

The content of the silane coupling agent (d) is preferably 0.1 to 5 parts by mass based on 100 parts by mass of the adhesive layer (Y), and more preferably 0.2 part by mass or more or 3.0 parts by mass or less. Furthermore, a coupling agent such as an organic titanate compound can be effectively used in the same manner as the silane coupling agent.

[Other materials] Examples of components other than the above contained in the present resin composition forming the adhesive layer (Y) include light stabilizers, ultraviolet absorbers, metal deactivators, anti-corrosive agents, and anti-aging agents. , Antistatic agent, hygroscopic agent, foaming agent, defoaming agent, inorganic particles, viscosity adjuster, adhesion-imparting resin, photosensitizer, fluorescent agent and other additives, reaction catalysts (tertiary amine compounds, Quaternary ammonium compounds, tin laurate compounds, etc.). Moreover, you may contain well-known components formulated in a general adhesive composition suitably. Moreover, you may use 2 or more types of each component together.

Among the above, it is particularly preferred that the present resin composition forming the adhesive layer (Y) contains an ultraviolet absorber. As described above, the adhesive layer (Y) has photo-hardening property which is hardened by irradiating light with a wavelength of 405 nm, and therefore does not prevent the photo-hardening even if it contains an ultraviolet absorber. Therefore, by including an ultraviolet absorber, it is possible to have excellent ultraviolet cutoff properties without impairing the properties of the present adhesive sheet.

Examples of the ultraviolet absorber include a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, and a triple-type ultraviolet absorber. Moreover, the said ultraviolet absorber can be used individually or in combination of 2 or more types. Among these, from the viewpoints of transparency, ultraviolet absorption, and compatibility, the above-mentioned ultraviolet absorber is particularly preferably a three-series ultraviolet absorber.

[Preferred composition state of the present resin composition] As an example of a preferable present resin composition for forming the adhesive layer (Y), a (meth) acrylate (co) polymer (a), the above-mentioned crosslinking Composition of agent (b), visible light initiator (c), and silane coupling agent as needed. Among them, it is preferable to use a visible light initiator (c) having a light absorption coefficient of 10 mL / (g · / cm) or more as the visible light initiator (c) at a wavelength of 405 nm; it is more preferable to use the above-mentioned splitting visible light. The initiator (c-1) and / or the hydrogen abstraction type visible light initiator (c-2) are used as the visible light initiator (c).

Among them, it is preferred that the (meth) acrylate (co) polymer (a) is formed based on a group selected from the group consisting of a carboxyl group and an epoxy group, a carboxyl group and an aziridinyl group, a hydroxyl group and an isocyanate group, and an amine group and an isocyanate. And a chemical bond in which a carboxyl group is combined with any functional group of an isocyanate group. The (meth) acrylate (co) polymer (a) preferably contains a linear or branched (meth) acrylic acid alkyl ester having 4 to 18 carbon atoms in the side chain and the hydrophilic (formaldehyde) Copolymer of acrylate) as a copolymer component. Furthermore, the crosslinking agent (b) is preferably the above-mentioned polyfunctional (meth) acrylate (b-1).

Examples of a preferable resin composition for forming the adhesive layer (Y) include the above-mentioned (meth) acrylate copolymer (a-1), the above-mentioned crosslinking agent (b), and a visible light initiator (c). And, if necessary, the composition of a silane coupling agent, 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) having a light absorption coefficient of 10 mL / (g · / cm) or more as the visible light initiator (c) at a wavelength of 405 nm; it is more preferable to use the above-mentioned splitting visible light. The initiator (c-1) and / or the hydrogen abstraction type visible light initiator (c-2) are used as the visible light initiator (c).

Among them, the (meth) acrylate (co) polymer (a-1) is preferably a linear or branched (methyl) group having 4 to 18 carbon atoms in the side chain as a skeleton component (dry component). ) A copolymer of an alkyl acrylate and the above-mentioned hydrophilic (meth) acrylate as a copolymerization component. The crosslinking agent (b) is preferably the above-mentioned polyfunctional (meth) acrylate (b-1).

As still another example of the present resin composition which is preferable for forming the adhesive layer (Y), the above-mentioned (meth) acrylate copolymer (a-1), the above-mentioned crosslinking agent (b), and the above-mentioned visible light initiation are mentioned. The composition of the agent (c) and, if necessary, the silane coupling agent. The (meth) acrylate copolymer (a-1) contains a macromonomer as a branch component and an active energy ray crosslinkable structural site. Branch copolymer. Among them, it is preferable to use a visible light initiator (c) having a light absorption coefficient of 10 mL / (g · / cm) or more as the visible light initiator (c) at a wavelength of 405 nm; it is more preferable to use the above-mentioned splitting visible light. The initiator (c-1) and / or the hydrogen abstraction type visible light initiator (c-2) are used as the visible light initiator (c).

Among them, the (meth) acrylate (co) polymer (a-1) is preferably a linear or branched (methyl) group having 4 to 18 carbon atoms in the side chain as a skeleton component (dry component). ) A copolymer of an alkyl acrylate and the above-mentioned hydrophilic (meth) acrylate as a copolymerization component. The crosslinking 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 composition as described above, the adhesive layer (Y) using the (meth) acrylate copolymer (a) or (a-1) as the base resin can be applied to The sheet is kept at room temperature and shows self-adhesiveness, so that the adhesive can be filled to each corner of the step of the adhered surface of the bonding member. In addition, the visible light initiator (c) allows light hardening by visible light irradiation, and can improve cohesion and increase foaming resistance by light hardening. Furthermore, by blending a silane coupling agent, it is possible to further improve the adhesion, especially the adhesion to a glass material. In addition, the adhesive layer (Y) using the (meth) acrylate copolymer (a-1) as a base resin also has a hot-melt property that melts or flows when heated, in addition to the above, so it can have a higher level difference. Absorptive.

As yet another example of the present resin composition which is preferable for forming the adhesive layer (Y), (meth) acrylate (co) polymer (a-2) containing the following monomer components, and the above-mentioned crosslinking agent (b ), The composition of the visible light initiator (c), and optionally a silane coupling agent, the monomer component includes an active energy ray crosslinkable structural site, and (A) having a linear alkyl group having 10 to 24 carbon atoms. ) Acrylate monomer. Among them, it is preferable to use a visible light initiator (c) having a light absorption coefficient of 10 mL / (g · / cm) or more as the visible light initiator (c) at a wavelength of 405 nm; it is more preferable to use the above-mentioned splitting visible light. The initiator (c-1) and / or the hydrogen abstraction type visible light initiator (c-2) are used as the visible light initiator (c).

When the present resin composition having the composition as described above is used, an adhesive layer (Y) which is temporarily hardened to a state where there is room for light hardening or is not hardened can be formed, and thereafter can be irradiated with visible light once or twice. And make it light hardened. Therefore, for example, after bonding the adhesive sheet to an adherend, the adhesive sheet can be light-hardened ("formally hardened") by visible light irradiation, and the cohesive force can be improved by the formal hardening to improve foam resistance. reliability. Especially for (meth) acrylic acid (co) polymers which have high fluidity at room temperature and have difficulties in storage, even when the step of improving storage properties by temporary hardening can be used, After the lamination, visible light hardening is performed in a subsequent step. By further blending a silane coupling agent, it is possible to further improve the adhesion, especially the adhesion to glass materials.

(Laminated structure) As described above, when the adhesive layer (Y) is a laminated structure, from the viewpoint of foam resistance, it is preferable that the adhesive layer (Y) using the resin composition is the outermost surface. Back layer. At this time, the thickness of the adhesive layer (Y) as the surface and back layer is preferably 15 μm or more, and 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 the reliability test, there is less risk of abnormalities such as pressure release of the gas pressure generated from the adherend member and foaming. .

Moreover, from the viewpoint of having both storage stability, there are cases in which it is better to have another layer having a higher viscosity than the adhesive layer (Y). That is, the adhesion layer (Y) formed by using a graft copolymer having a macromonomer is in an uncrosslinked state before light curing. If a polyfunctional (meth) acrylate monomer is used, the polyfunctional (meth) acrylate The role of the (meth) acrylate monomer component may cause the adhesive layer (Y) before light curing to become a relatively low-viscosity layer. Therefore, in this case, it is preferable that another layer (Z) having a higher viscosity than the adhesive layer (Y) is laminated on the adhesive layer (Y). For example, if it has a multilayer structure including three layers of an adhesive layer (Y) / layer (Z) / adhesive layer (Y), it can have both excellent storage stability. From the viewpoint of such 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 a temperature range of 70 ° C to 100 ° C. The viscosity is a value measured in accordance with the method described in the examples.

When the adhesive sheet has a multilayer structure as described above, the glass transition temperature (Tg) of the adhesive sheet after irradiation with 405 nm light is preferably from the viewpoint of further having impact resistance and absorption. It is less than 20 ° C, more preferably less than 10 ° C. By providing the present adhesive sheet with such a relatively low Tg, low-temperature adhesive properties (such as low-temperature peel strength) can be improved, and impact absorption properties can be improved. Therefore, from the viewpoint of impact absorption resistance, the Tg after irradiation with 405 nm light of the other layers laminated with the above-mentioned adhesive layer (Y) is particularly preferably less than 15 ° C, more preferably less than 10 ° C, and especially less than 10 ° C. Up to 5 ° C. The Tg is a value measured at the peak temperature of Tan δ of the dynamic viscoelasticity, and specifically 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 form an adhesive sheet with a release film.

As a material of this release film, a well-known release film can be used suitably. As a material of the release film, for example, a polyester film, a polyolefin film, a polycarbonate film, a polystyrene film, an acrylic resin film, a triethyl cellulose film, a fluororesin film, or the like can be appropriately selected and applied. Silicone resin is used after being subjected to a release treatment, release paper, or the like.

In the case where the release film is laminated on both sides of the adhesive sheet, one release film may be the same laminate structure or material as the other release film, or it may be a different laminate structure or material. The thickness may be the same or different. 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 having a wavelength of 410 nm or less. Since a release film having a light transmittance of 40% or less is laminated on at least one side of the adhesive sheet, light polymerization at a wavelength of 410 nm or less can be effectively prevented from occurring due to irradiation with visible light. From this point of view, the release film laminated on one or both sides of the adhesive sheet preferably has a light transmittance of light having a wavelength of 410 nm or less and a light transmittance of 40% or less, and further preferably 30% or less, of which It is more preferably 20% or less.

Here, as a release film having a light transmittance of 40% or less for light having a wavelength of 410 nm or less, that is, a film having a function of blocking the transmission of a part of visible light and ultraviolet light, for example, a laminated film including an ultraviolet absorbing layer is mentioned. The above-mentioned ultraviolet absorbing layer is coated on one side of a polyester-based, polypropylene-based, or polyethylene-based casting film or stretched film with a micro-adhesive resin having re-peelability, and the other side is coated with a UV-absorbing agent. Painter. In addition, a micro-adhesive resin having an ultraviolet absorber and a re-peeling property can be applied to one surface of a polypropylene-based or polyethylene-based cast film or stretched film. In addition, examples include a cast film or a stretched film containing a polyester-based, polypropylene-based, or polyethylene-based resin formulated with an ultraviolet absorber, and coated with a micro-adhesive resin having re-peelability. In addition, the multilayer cast film or the stretched film is coated with a micro-adhesive resin having re-peelability on one side, and the multilayer cast film or the stretched film is made of a polyester system containing an ultraviolet absorber, One or both sides of a polypropylene or polyethylene resin layer is formed by forming a layer containing a resin containing no ultraviolet absorber. In addition, a coating containing a UV absorbent is applied to one surface of a cast film or stretch film containing a polyester-based, polypropylene-based, or polyethylene-based resin to provide a UV-absorbing layer, and the UV-absorbing layer is further coated. Fabric made of micro-adhesive resin with re-peelability. In addition, a coating containing a UV absorbent is applied to one surface of a cast film or stretch film containing a polyester-based, polypropylene-based, or polyethylene-based resin, and an ultraviolet-absorbing layer is provided. Removable micro-adhesive resin. In addition, a resin film containing a polyester-based, polypropylene-based, or polyethylene-based resin, which is coated with a micro-adhesive resin having re-peelability on one surface, is further interposed between an adhesive layer or an adhesive layer containing an ultraviolet absorber. The other side is laminated with a separately prepared resin film. The above-mentioned film may also have other layers such as an antistatic layer or a hard coat layer and a tackifier layer as needed.

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

In addition, the present adhesive sheet can also adopt the following method: as described above, no adherend or release film is used, such as a method of directly extruding the resin composition or injecting it into a mold Medium and shaped method. Furthermore, the present resin composition may be directly filled between the constituent members for an image display device as an adherend, thereby making it the state of the present adhesive sheet.

<The manufacturing method of this adhesive sheet> An example of the method of manufacturing this adhesive sheet is demonstrated. First, a (meth) acrylate (co) polymer (a) and a visible light initiator (c), if necessary, a cross-linking agent (b), and if necessary, a silane coupling agent (d), and if necessary, Further, other materials may be mixed in a specific amount to prepare the present resin composition. There are no particular restrictions on the mixing method, and the mixing order of the components is also not particularly limited. In addition, a heat treatment step may be added during the production of the composition. In this case, it is desirable to perform heat treatment after mixing the components of the resin composition in advance. It is also possible to use one obtained by concentrating and mixing various mixed components.

The device for mixing is also not particularly limited. For example, a universal mixer, a planetary mixer, a Banbury mixer, a kneader, a frame mixer, a pressure kneader, a three-roll mill, and a two-roll mill can be used. If necessary, a solvent may be used for mixing. The present resin composition can be used as a solvent-free solvent-free system. By using it as a solventless system, it has the advantage that a solvent does not remain, and heat resistance and light resistance are improved. From this viewpoint, it is also preferable that the resin composition is a form including a (meth) acrylate (co) polymer (a), a crosslinking agent (b), and a visible light initiator (c).

The present adhesive sheet can be produced by coating (coating) the present resin composition prepared in the above manner on a base material sheet or a release sheet. In addition, for example, the present adhesive sheet composed of a laminate can be produced by a method of repeating the steps of coating (applying) the present resin composition on a base material sheet or a release sheet. , Forming a first layer, coating (coating) the resin composition on the formed first layer to form a second layer; forming the first layer and the second layer in the same manner as above, and thereafter A method in which the coated (coated) surfaces are adhered to each other; or a method in which the present resin composition is simultaneously formed into a first layer and a second layer by multi-layer coating or coextrusion.

The said coating (application) method is not specifically limited if it is a general coating method. For example, methods such as roll coating, die coating, gravure coating, notch coating, and screen printing can be mentioned.

Then, if necessary, the adhesive layer containing the present resin composition is irradiated with light to temporarily harden the adhesive layer (Y) and leave room for photo-hardening. 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 cured by heat or curing, or may be in an uncured state.

<Application of this adhesive sheet> This adhesive sheet can be suitably used for bonding a resin member (X) as mentioned above. Therefore, it is possible to provide an adhesive sheet laminate (referred to as "this adhesive sheet laminate") composed of a resin member (X) having specific characteristics laminated with the present adhesive sheet.

The present 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 produce the present adhesive sheet, and stacking the present adhesive sheet On the resin member (X). However, the manufacturing method of this adhesive sheet laminated body is not limited to this method.

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

If the light transmittance at 365 nm of the resin member (X) is 10% or less and the light transmittance at 405 nm is 60% or more, it is possible to sufficiently block (cut off) the transmission of ultraviolet rays and suppress the resin member (X) The optical degradation of itself and optical components (such as optical films such as polarizing films or retardation films) located on the back side (opposite to the recognized side surface) of the optical components can be reduced, and the yellowness (YI) can be reduced to the level required by the optical components. Examples of such a resin member (X) include those containing a resin material as a main component and adjusted to have the above-mentioned light transmittance using an ultraviolet absorber.

Examples of the resin material include a material containing a polycarbonate resin or an acrylic resin as a main component resin. At this time, the "main component resin" means a resin having the highest mass among the resins constituting the resin member (X).

Moreover, regarding this adhesive sheet, for example, the said resin member (X) and an image display panel (P) can be bonded together via this adhesive sheet to form a photocurable adhesive sheet laminate, and from this resin member (X The resin sheet (X) is used to irradiate the adhesive sheet with a cumulative light amount of 3,000 (mJ / cm ² ) at 405 nm, thereby hardening the adhesive layer (Y) and condensing it so that The gel fraction difference is 10% or more, and an image display panel laminate is manufactured.

This adhesive sheet laminated body can be bonded to an image display panel (P), for example, and an image display panel laminated body can be manufactured. Specifically, an image display panel laminate including a structure in which the adhesive sheet laminate is bonded to an image display panel (P) can be, for example, a resin member (X) and an image display panel (P). After the adhesive sheet is laminated, the resin member (X) is irradiated with light having a wavelength of 405 nm from the outside of the resin member (X), and the adhesive layer (Y) of the adhesive sheet is hardened to form the resin member ( X) Lamination with an image display panel (P) to manufacture an image display panel laminate. Furthermore, the method of laminating the resin member (X) and the image display panel (P) through the 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, and the resin member (X) and the image display panel (P) can also be laminated with the adhesive sheet at the same time.

(Image display panel (P)) The image display panel (P) includes, for example, other optical films such as a polarizing film and a retardation film, a liquid crystal material, and a backlight system (normally, the composition or an adhesive article). In contrast to the adhered surface of the image display panel, which is an optical film), there are STN method, VA method, or IPS method depending on the control method of the liquid crystal material, which may be any method. In addition, the image display panel may be an in-cell type in which a touch panel function is built in a TFT-LCD, or a touch panel function may be built in a glass substrate provided with a polarizing plate and a color filter. Table embedded.

As for the present adhesive sheet, from the viewpoint of resistance to foaming reliability, it is particularly preferable that the adhesive layer (Y) in a state where the target is adhered as described above, that is, the adhesive layer after light (present) curing ( Y) It has a crosslinked structure of the present resin composition. In particular, the adhesive layer (Y) is particularly preferably a (meth) acrylate copolymer having an active energy ray-curable site, or a (meth) acrylate (co-) having a functional group (i) as described above. ) A polymer (a), a chemical bond with a compound having a functional group (ii) that reacts with the functional group (i), or a polyfunctional (meth) acrylic acid ester having three or more functions not modified with an alkylene oxide It is formed with a cross-linked structure caused by these.

<< Description of Sentences >> In the present invention, a case called "film" also includes a "sheet", and a case called "sheet" also includes a "film". In addition, a case which appears as a "panel" like 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 to 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 " It is preferably less than Y ". In addition, when it is described as "more than X" (X is an arbitrary number), unless otherwise specified, it includes the meaning of "preferably greater than X" and is described as "below Y" (Y is an arbitrary number) In such cases, the meaning of "preferably less than Y" is included unless otherwise specified. [Example]

Hereinafter, it demonstrates in detail based on an Example. However, the present invention is not limited to the embodiments described below.

<Examples and Comparative Examples> Materials used in the examples and comparative examples will be described.

[Example 1] (Photocurable adhesive sheet Y) As a (meth) acrylate (co) polymer, a terminal functional group containing isomethacrylate: methyl methacrylate = 1: 1 was prepared as 13.5 parts by mass of a methacrylfluorene macromonomer (number average molecular weight is 3000), 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 resulting 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 to 1 kg of the acrylic graft copolymer, and cracking was included as a visible light initiator. A mixture of visible light initiators, namely 2,4,6-trimethylbenzylidene diphenylphosphine oxide, oligo (2-hydroxy-2-methyl-1- (4- (1-methyl 15 g of a mixture of vinyl vinyl) phenyl) acetone), 2,4,6-trimethylbenzophenone and 4-methylbenzophenone (Esacure KTO46 manufactured by Lamberti), uniformly mixed to obtain light Hardening composition. Next, the photocurable composition was formed into a sheet on a polyethylene terephthalate film (manufactured by Mitsubishi Resin Corporation, DIAFOIL MRV, thickness 100 μm) with a peeling treatment on the surface so that the thickness became 150 μm. Then, a polyethylene terephthalate film (manufactured by Mitsubishi Resin Co., Ltd., DIAFOIL MRQ, thickness: 75 μm) was coated on the surface, and a photocurable adhesive sheet Y1 with a release film was produced. The photocurable adhesive sheet Y1 is a photocurable adhesive sheet that is cured by irradiating light.

(Resin member X) As the resin member (X), a polycarbonate-based resin plate (manufactured by Mitsubishi Gas Chemical Co., Ltd., Iupilon sheet MR58) containing a UV absorber was used. The thickness was 1.0 mm (used in the bonding structure P). And 1.5 mm (used in the bonding structure Q and the bonding structure R). Any thickness is 0% light transmittance at 365 nm and 83% light transmittance at 405 nm.

(Photocurable Adhesive Sheet Laminate) Peel off the release film on one side of the photocurable adhesive sheet Y1 with a release film, and stick to one side of the polycarbonate plate (resin member X) with a roller. To obtain a photocurable adhesive sheet laminate (also referred to as “X / Y1 laminate”) of the resin member (X) / photocurable adhesive sheet Y1.

[Example 2] The type of the cross-linking agent of the photocurable adhesive sheet Y was changed to pentaerythritol triacrylate (manufactured by Shin Nakamura Chemical Co., Ltd., NK ESTER ATMM3), and the number of prepared ingredients was changed to acrylic copolymerization. The weight of 1 kg was 70 g, except that the same procedure as in Example 1 was performed to obtain a photocurable adhesive sheet Y2 and X / Y2 laminate. The photocurable adhesive sheet Y2 is a photocurable adhesive sheet that is cured by irradiating light.

[Example 3] The composition of the (meth) acrylic copolymer of the photocurable adhesive sheet Y was changed to a terminal functional group containing an isomethacrylate: methyl methacrylate = 1: 1. Macropropylene monomer (number average molecular weight is 3000) 12.7 parts by mass, 41.1 parts by mass of lauryl acrylate, 37.6 parts by mass of 2-ethylhexyl acrylate, 2.6 parts by mass of allyl methacrylate, and 4-hydroxybutyl acrylate 6 parts by mass of 100% by mass of an acrylic graft copolymer containing a hydroxyl group (mass average molecular weight: 160,000) obtained by random copolymerization, and obtained by addition reaction with 6.5 parts by mass of 2-isocyanate ethyl methacrylate A (meth) acrylic copolymer having an active energy ray crosslinkable structural site having a carbon-carbon double bond was carried out in the same manner as in Example 1 to obtain a photocurable adhesive sheet Y3 and X / Y3 laminate. body. The photo-curable adhesive sheet Y3 is a photo-curable adhesive sheet that is cured by irradiating light.

[Example 4] The following was used as a photocurable adhesive sheet, that is, a hydrogen abstraction type visible light initiator phenylglyoxylate (manufactured by BASF, Irgacure MBF) was used as a visible light initiator. A light-curing adhesive sheet Y4 and X were obtained in the same manner as in Example 1 except that the light was irradiated so that the cumulative amount of light at 405 nm was 100 (mJ / cm ² ), and then cured (crosslinked). / Y4 laminated body. The photo-curable adhesive sheet Y4 is a photo-curable adhesive sheet that is cured by irradiating light.

[Example 5] As the (meth) acrylate (co) polymer, a macromonomer containing a methacrylic acid isoester: methyl methacrylate = 1: 1 and having a terminal functional group of methacrylfluorene ( Number average molecular weight is 3000) An acrylic graft copolymer (mass) obtained by random copolymerization of 13.5 parts by mass, 73.7 parts by mass of 2-ethylhexyl acrylate, 2.8 parts by mass of acrylamide, and 10 parts by mass of methacrylate (Average molecular weight: 260,000), and the type of cross-linking agent was changed to pentaerythritol triacrylate (manufactured by Shin Nakamura Chemical Co., Ltd., NK ESTER ATMM3L), and the number of preparations was changed to 1 kg of acrylic graft copolymer Except having set it as 70 g, it carried out similarly to Example 1, and obtained the photocurable adhesive sheet Y5 and X / Y5 laminated body. The photocurable adhesive sheet Y5 is a photocurable adhesive sheet that is cured by irradiating light.

[Example 6] A photocurable adhesive sheet Y6 and a photocurable adhesive sheet Y6 were obtained in the same manner as in Example 5 except that the blending amount of the crosslinking agent was changed to 120 g relative to 1 kg of the acrylic graft copolymer. X / Y6 laminated body. The photo-curable adhesive sheet Y6 is a photo-curable adhesive sheet that is cured by irradiating light.

[Example 7] The type of the cross-linking agent was set to 1 kg with respect to the acrylic graft copolymer, and pentaerythritol triacrylate (manufactured by Shin Nakamura Chemical Co., Ltd., NK ESTER ATMM3L) and dipentaerythritol tetraacrylate (Sin Nakamura Except for 90 g and 30 g each of NK ESTER A9570W (manufactured by Chemical Co., Ltd.), a photocurable adhesive sheet Y7 and an X / Y7 laminate were obtained in the same manner as in Example 5. The photo-curable adhesive sheet Y7 is a photo-curable adhesive sheet that is cured by irradiating light.

[Example 8] The type of the cross-linking agent was set to 1 kg with respect to the acrylic graft copolymer, and pentaerythritol triacrylate (manufactured by Shin Nakamura Chemical Co., Ltd., NK ESTER ATMM3L) and dipentaerythritol tetraacrylate (Sin Nakamura NK ESTER A9570W (manufactured by Chemical Co., Ltd.) was carried out in the same manner as in Example 5 except that each of 120 g and 40 g was used to obtain a photocurable adhesive sheet Y8 and an X / Y8 laminate. The photo-curable adhesive sheet Y8 is a photo-curable adhesive sheet that is cured by irradiating light.

[Example 9] A macromonomer containing a methacryl isopropyl group as a (meth) acrylic copolymer containing a methyl methacrylate: methacrylic acid terminal = 1: 1 (quantity average) Molecular weight 3,000) Acrylic graft copolymer (mass average molecular weight: 13.5 parts by mass, 73.7 parts by mass of 2-ethylhexyl acrylate, 2.8 parts by mass of acrylamide, and 10 parts by mass of methacrylate) 260,000) 1 kg, using pentaerythritol triacrylate (manufactured by Shin Nakamura Chemical Co., Ltd., NK ESTER ATMM3L) and dipentaerythritol tetraacrylate (manufactured by Shin Nakamura Chemical Co., Ltd., NK ESTER A9570W) in an amount of 75 g and 25 g, respectively. Crosslinking agent, as a visible light initiator, a mixture containing a cleavable visible light initiator, that is, 2,4,6-trimethylbenzylidene diphenylphosphine oxide, oligo (2-hydroxy-2 -Methyl-1- (4- (1-methylvinyl) phenyl) acetone), a mixture of 2,4,6-trimethylbenzophenone and 4-methylbenzophenone (Lamberti 15 g of Esacure KTO46), uniformly mixed with 3-glycidoxypropyltrimethoxysilane as a silane coupling agent 2 g (KBM403 manufactured by Shin-Etsu Silicone Co., Ltd.) to obtain a photocurable composition. Next, the above photocurable composition was formed on a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, DIAFOIL MRV, thickness 100 μm) on the surface of which was peeled to a thickness of 25 μm. Sheet-shaped, and then covered with a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, DIAFOIL MRQ, thickness 75 μm) with a peeling treatment on the surface, to produce an adhesive sheet for the front and back layers with a release film Y9a.

A pentaerythritol triacrylate (Shin Nakamura Chemical Co., Ltd.) was added as a cross-linking agent to 1 kg of the acrylic graft copolymer used as the (meth) acrylic copolymer in the adhesive sheet Y9a for the front and back layers. NK ESTER ATMM3L manufactured by the company, 30 g, as a visible light initiator, a mixture containing a cleavable visible light initiator, that is, 2,4,6-trimethylbenzylidene diphenylphosphine oxide, oligo ( 2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) acetone), 2,4,6-trimethylbenzophenone, 4-methylbenzophenone 15 g of the mixture (Esacure KTO46 manufactured by Lamberti) was uniformly mixed to obtain a photocurable composition. Next, the above photocurable composition was formed on a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, DIAFOIL MRV, thickness 100 μm) on the surface of which was peeled to a thickness of 100 μm. Sheet-like, and then coated with a polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, DIAFOIL MRQ, thickness 75 μm) with a peeling treatment on the surface, to produce an adhesive sheet Y9b for an intermediate layer with a release film .

The PET films on both sides of the adhesive sheet Y9b for the intermediate layer were sequentially peeled off and removed, and the adhesive surfaces of the two adhesive sheets Y9a for the front and back layers were sequentially adhered to both surfaces of the adhesive sheet Y9b for the intermediate 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 middle layers) / (adhesive sheet Y9a for front and back layers) Two kinds of three-layer laminates (total thickness: 150 μm) were carried out in the same manner as in Example 1 to obtain X / Y9 laminates.

[Example 10] The (meth) acrylic copolymer used in the above-mentioned adhesive sheet Y9b for an intermediate layer was changed to include an isomethacrylate: methyl methacrylate = 1: 1, and the terminal functional group was formazan 13.5 parts by mass of acryl-based 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 An acrylic graft copolymer (mass average molecular weight: 160,000) was used to form an adhesive sheet Y10b for an intermediate layer, and a photocurable adhesive sheet Y10 and X / Y10 laminate were obtained in the same manner as in Example 9. The photo-curable adhesive sheet Y10 includes two types of three-layer laminate ((adhesive sheet for front and back layer Y9a) / (adhesive sheet for middle layer Y10b) / (adhesive sheet for front and back layer Y9a)) (Total thickness is 150 μm). The photo-curable adhesive sheet Y10 is a photo-curable adhesive sheet that is cured by irradiating light.

[Comparative Example 1] As a photocurable adhesive sheet, a hydrogen abstraction type initiator as a photo initiator, that is, 2,4,6-trimethylbenzophenone and 4-methylbenzophenone was used. A mixture of ketones (Esacure TZT manufactured by Lamberti, Inc.) was carried out in the same manner as in Example 1 to obtain a photocurable adhesive sheet Y11 and an X / Y11 laminate.

[Comparative Example 2] As a photocurable adhesive sheet, a hydrogen abstraction type initiator as a photoinitiator, that is, 1- [4- (4-benzylidenephenylthio) phenyl]- A photocurable adhesive sheet Y12 was obtained in the same manner as in Example 1 except that 2-methyl-2- (4-methylphenylsulfonyl) propane-1-one (Esacure 1001M, manufactured by Lamberti) was used. And X / Y12 laminated body.

[Comparative Example 3] A photo-curable adhesive was obtained in the same manner as in Example 1 except that a commercially available non-curable optical transparent adhesive sheet having no photo-curability was used as the photo-curable adhesive sheet. Laminates of sheet Y13 and X / Y13.

[Comparative Example 4] As the resin member X, a polycarbonate-based resin plate (with a thickness of 1.0 mm, a light transmittance at 365 nm of 45%, and a light transmittance at 405 nm of 91%) was used. ), Other than that, it carried out similarly to Example 1, and obtained the photocurable adhesive sheet Y14 and X / Y14 laminated body.

<Evaluation> The evaluation method shown in this specification is demonstrated.

(1) Dynamic storage modulus (G ') Regarding each of the 150 μm light-curable adhesive sheets Y1 to Y14 (without release film) obtained in the examples and comparative examples, 8 sheets were overlapped to make it 1200. μm, using a dynamic viscoelasticity measuring device rheometer ("MARS" manufactured by Hidehiro Seiki Co., Ltd.), a Φ25mm parallel plate, a strain of 0.5%, a frequency of 1 Hz, and a heating rate of 3 ° C / min The measurement was performed under the conditions.

(2) Spectral transmittance About 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 a light transmittance.

(3) Gel fractions For each of the photocurable adhesive sheets Y1 to Y14 (without release film) obtained in the examples and comparative examples, the SUS net (♯200 ) The bag is in the shape of a bag, and the mouth of the bag is closed to measure the mass (Y) of the bag. Then, it is dipped in 100 ml of ethyl acetate, and stored at 23 ° C in a dark place for 24 hours. It was heated at 70 ° C for 4.5 hours to evaporate the attached ethyl acetate, and the mass (Z) of the dried bag was measured. The obtained mass was substituted into the following formula to obtain a gel fraction X1. Gel fraction (%) = [(Z-X) / (Y-X)] × 100

In addition, regarding each of the X / Y1 to Y14 laminates obtained in the examples and comparative examples, from the resin member (X) side, a high-pressure mercury lamp was used at a cumulative light amount of 3,000 (mJ / cm ² ) at 405 nm. After irradiating light, a sample was taken from the adhesive layer portion on the resin member (X) side surface of the photocurable adhesive sheet, and the gel fraction X2 was obtained by the same method as described above. And calculate X2-X1.

(4) Step absorptivity The thickness of the peripheral part (long side 3 mm, short side 15 mm) of 58 mm × 110 mm × 0.8 mm glass is printed with a thickness of 22 to 24 μm. 52 mm × 80 mm glass plate with printing step. Regarding each of the photocurable adhesive sheets Y1 to Y14 with a release film obtained in the examples and comparative examples, a release film was peeled off, and a soda-lime glass (54 mm × 82 mm × thickness) was bonded by a roller. 0.5 mm) on the entire surface, peel off the remaining mold release film, and use vacuum pressure to perform pressure bonding using vacuum pressure to cover the frame-shaped printing step of the glass plate with printing steps as described above with an adhesive sheet. The temperature was 25 ° C and the pressure was 0.13 MPa), and an evaluation sample was prepared. After the autoclave treatment was performed on the evaluation samples under the conditions of 60 ° C., 0.2 MPa, and 20 minutes, it was judged as pass or fail according to the following evaluation criteria. ○ (Good): Fine bubbles were not seen at the periphery of the step × × (Poor): Fine bubbles were seen at the periphery of the step

(5) Yellowness (YI) Regarding each of the X / Y1 to Y14 laminates obtained in the examples and comparative examples, from the resin member (X) side, using a high-pressure mercury lamp, the accumulated light amount at 3000 (mJ) at 405 nm / cm ² ). The so-called cumulative light quantity at 405 nm is a UV cumulative light meter "UIT-250" (made by Niuwei Electric Co., Ltd.) and a light receiver "UVD-C405" (made by Niuwei Electric Co., Ltd.). The cumulative light amount measured by installing a light meter on the opposite side of the side irradiated by the high-pressure mercury lamp, and passing through the resin member (X) to the photocurable adhesive sheet (Y1 to Y14). Thereafter, the yellowness (YI) of the X / Y1 to Y14 laminate was measured using a spectrophotometer (Suga test machine (stock)) "SC-T" based on JIS K7103, and the pass or failure was judged by 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 laminates obtained in the examples and comparative examples, from the resin member (X) side, using a high-pressure mercury lamp, the cumulative light amount at 3000 nm (mJ) / cm ² ). The so-called cumulative light quantity at 405 nm is a UV cumulative light meter "UIT-250" (made by Niuwei Electric Co., Ltd.) and a light receiver "UVD-C405" (made by Niuwei Electric Co., Ltd.). The cumulative light amount measured by installing a light meter on the opposite side of the side irradiated by the high-pressure mercury lamp, and passing through the resin member (X) to the photocurable adhesive sheet (Y1 to Y14). Thereafter, a UVB fluorescent lamp (G15T8E, manufactured by Sankyo Electric Co., Ltd., with an irradiance of 70 μW / cm ² ) was used to perform an irradiation test at a distance of 20 cm and 72 hr. According to the change amount ΔYI of the yellowness (YI) of the X / Y1 to Y14 laminated body before and after the irradiation, the 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 Reliability About each of the X / Y laminates obtained in the examples and comparative examples, peel off the other release film remaining on the Y surface side, and stick it on the exposed surface by a hand pressure roller The following three types of members were attached to evaluate the foaming resistance during bonding. Moreover, the X / Y laminated body was cut and used for the size of each member. The specific bonding structure is 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) This 3 kinds. 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, the component P (bonded structure P) was subjected to autoclave treatment at a temperature of 60 ° C. and an air pressure of 0.2 MPa for 30 minutes to perform final bonding. The components Q and R (bonded structure Q and R ), An autoclave treatment was performed under conditions of a temperature of 80 ° C., an air pressure of 0.2 MPa, and 30 minutes, and final adhesion was performed.

After the final adhesion, light was irradiated from the resin member (X) side using a high-pressure mercury lamp so that the cumulative light amount at 405 nm became 3000 (mJ / cm ² ) to prepare a foaming reliability evaluation sample. The above evaluation samples were exposed to an environment of 85 ° C. and 85% RH for 24 hr, and those with no appearance defects such as foaming or peeling were determined as “○ (good)”, and those who found foaming or peeling were determined as “× (good) difference)". In addition, those with no appearance defects such as foaming or peeling in the bonded structure P or Q (single-sided glass member) and bonded structure R (double-sided resin member) will be comprehensively judged as "◎ (excellent)", In any of the bonded structures P, Q, and R, no defective appearance such as foaming or peeling was found, and it was judged as "0 (good)". Foaming or peeling will be found in all of the bonded structures P, Q, and R. The overall judgment is "× (poor)".

(8) Haze (indicator of compatibility with cross-linking agent) after long-term storage Regarding each of the photocurable adhesive sheet Y obtained in the examples and comparative examples, two months have passed after the sheet was made. After that, the two sides of the soda-lime glass (thickness 0.55 mm) were used to sandwich the two-sided adhesive surface exposed by peeling the release film of the adhesive sheet Y, and a high-pressure mercury lamp was used at 405 nm. After the light was irradiated so that the accumulated light amount became 3000 (mJ / cm ² ), the haze value was measured. The haze value was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., NDH5000) in accordance with JIS K7136. Those with a haze value of less than 0.5 were judged to be "○ (good)", those with a haze value of 0.5 or more and less than 1.0 were judged to be "△ (OK)", and those with a haze value of 1.0 or more were judged to be " × (poor) ".

(9) Tg after photo-hardening For each of the 150 μm photo-curable adhesive sheets Y1 to Y14 (without release film) obtained in the examples and comparative examples, the cumulative light amount at 405 nm was 3000 ( mJ / cm ² ) after irradiation with light, 8 photo-curable adhesive sheets Y1 to Y14 were superimposed so that they became 1200 μm, and a dynamic viscoelasticity measuring device rheometer ("Eihong Seiki Co., Ltd." MARS "). The measurement was performed under the conditions that the adhesion jig was a Φ25 mm parallel plate, the strain was 0.5%, the frequency was 1 Hz, and the heating rate was 3 ° C / min. The temperature at which the value of Tan δ obtained by the measurement became a peak was taken as Tg.

(10) Viscosity Regarding each of the 150 μm light-curable adhesive sheets Y1 to Y14 (without release film) obtained in the examples and comparative examples, 8 of them were stacked to make it 1200 μm, and dynamic adhesion was used. Elasticity measuring device rheometer ("MARS" manufactured by Hidehiro 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 heating rate is 3 ° C / min. Re-viscosity of the adhesive sheet before light curing at 70 ° C and 100 ° C.

(11) Storage: Cut a 50 mm × 50 mm square light-curable adhesive sheet Y1 ～ Y14 between two 100 mm × 100 mm square PET films with a thickness of 100 μm to make a laminated body. After standing at 23 ° C and 50% for 300 hours, visually observe whether the adhesive overflowed from the laminate. The laminated body produced was visually observed, and those who spilled the entire adhesive were judged to be "× (poor)", those who only spilled from the corners were judged to be "△ (OK)", and those who did not overflow were judged. "○ (良)".

[Table 1]

<Examination> 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 placed on the self-resin member (X ) Side When the light is irradiated such that the cumulative light quantity at a wavelength of 405 nm becomes 3000 (mJ / cm ² ), the light-curing adhesive sheets Y1 to Y10 can be sufficiently hardened until the difference in gel fraction increases by more than 10%. Dynamic storage The modulus (G ') maintains a high-temperature cohesive force of 0.7 × 10 ⁴ Pa or higher at 120 ° C. and 1 Hz, and thus obtains good foaming resistance. In particular, the touch sensor obtained a good resistance to foaming in a test assuming a case of a glass sensor. Among them, the dynamic storage modulus (G ') of Examples 3, 7, 9, and 10 maintained a high-temperature cohesive force of 2.0 × 10 ⁴ Pa or higher at 120 ° C. and 1 Hz. Therefore, the touch sensor is a hypothetical film sensor. In the case of the test, good foaming resistance was also obtained.

In addition, in Example 8, although the touch sensor obtained good resistance to foaming in the test under the assumption of a film sensor, the touch sensor produced glass in the test under the assumption of a glass sensor. Peeling off. The reason for this is considered to be that the dynamic storage modulus (G ') became too high at 120 ° C and 1 Hz, and the viscosity and adhesion performance were reduced. In addition, in Example 2, since the content of the hydrophilic monomer constituting the (meth) acrylate (co) polymer (a) is 10 parts by mass or less, the phase separation was performed during long-term storage, so the fog after long-term storage The degree is "△ (Fair)". Examples 1 to 10 have good absorptivity, and the cover member having a printing step can be practically used depending on the type of the touch sensor.

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

The light-curing adhesive sheets Y11 and Y12 of Comparative Examples 1 and 2 had a light transmittance (%) of more than 90% at a wavelength of 390 nm, and the cumulative light amount at a wavelength of 405 nm from the resin member (X) side became 3000 ( mJ / cm ² ) when the light is irradiated, the excitation and curing (cross-linking) reaction is not sufficient because the light initiator absorbs the light, so the adhesive layer (Y) cannot be sufficiently hardened, and it is resistant to foaming reliability tests. Bubbles are generated.

The gel fraction of the photo-curable adhesive sheet Y13 of Comparative Example 3 was 88%, and the dynamic storage modulus (G ′) (25 ° C.) was as high as 1.1 × 10 ⁵ Pa. Therefore, the step absorbency was poor and bubbles were generated. Since the resin member (X) of Comparative Example 4 did not contain an ultraviolet absorber, and the light transmittance at a wavelength of 365 nm was as high as 45%, yellowing in the UV resistance reliability test was performed.

Claims (26)

A light-curable adhesive sheet characterized by including an adhesive layer (Y) having all of the following characteristics (1) to (3): (1) gel fraction (referred to as "gel fraction before light irradiation X1" ") Is in the range of 0 to 60%; (2) the light transmittance at a wavelength of 390 nm is 89% or less, and the light transmittance at a wavelength of 410 nm is more than 80%; (3) it has an irradiation wavelength of 405 nm light and hardened light hardenability. For example, the photocurable adhesive sheet according to claim 1, wherein the photocurability in (3) above is a photocurability in which the difference in gel fraction is increased by more than 10% when the light having a wavelength of 405 nm is irradiated. For example, the photocurable adhesive sheet of claim 1 has the following photocurability: When the light having a cumulative light amount of 3000 (mJ / cm ² ) at a wavelength of 405 nm is irradiated, the gel fraction before light irradiation ( Gel fraction before light irradiation X1) and gel fraction after light irradiation (referred to as "gel fraction after light irradiation X2") (gel fraction after light irradiation X2-gel fraction before light irradiation The ratio X1) is 10% or more. The photocurable adhesive sheet 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 according to any one of claims 1 to 4, wherein the adhesive layer (Y) contains a silane coupling agent. The photocurable adhesive sheet according to claim 4 or 5, wherein the (meth) acrylate (co) polymer is formed based on a group selected from a carboxyl group and an epoxy group, a carboxyl group and an aziridinyl group, and a hydroxyl group and an isocyanate A chemical bond in which any of the functional groups of a amine group, an amine group and an isocyanate group, and a carboxyl group and an isocyanate group is combined. The photocurable adhesive sheet according to claim 4 or 5, wherein the (meth) acrylate (co) polymer is a graft copolymer having a macromonomer as a branch component. The photocurable adhesive sheet according to any one of claims 4 to 7, wherein the visible light initiator is a hydrogen abstraction type visible light initiator. The photocurable adhesive sheet according to claim 8, wherein the hydrogen abstraction type visible light initiator is selected from the group consisting of methyl phenylglyoxylate and hydroxyphenylacetic acid 2- [2- pendantoxy-2-phenylacetamidine Either or two of the group consisting of a mixture of oxyethoxy] ethyl ester and 2- [2-hydroxyethoxy] ethyl hydroxyphenylacetate. The photocurable adhesive sheet according to any one of claims 4 to 9, wherein the (meth) acrylate (co) polymer is a linear or branched chain having a carbon number of 4 to 18 (a A copolymer of an alkyl acrylate and a hydrophilic (meth) acrylate as copolymerization components. The photocurable adhesive sheet according to any one of claims 1 to 10, wherein the adhesive layer (Y) is formed by containing a crosslinking agent or using a crosslinking agent. The photocurable adhesive sheet according to claim 11, wherein the above-mentioned crosslinking agent is a trifunctional or higher polyfunctional (meth) acrylate which is not modified with alkylene oxide. The photocurable adhesive sheet according to any one of claims 4 to 12, wherein the (meth) acrylate (co) polymer has an active energy ray crosslinkable structural site. The photocurable adhesive sheet according to any one of claims 1 to 13, wherein the storage modulus (G ') at a temperature of 25 ° C and a frequency of 1 Hz is 0.9 × 10 ⁵ Pa or less. For example, the photocurable adhesive sheet according to any one of claims 1 to 14, wherein the storage modulus (Y) of the adhesive layer (Y) after irradiation with light having a cumulative light amount of 3000 (mJ / cm ² ) at a wavelength of 405 nm ( G ') is 0.7 × 10 ⁴ Pa or more at a temperature of 120 ° C. and a frequency of 1 Hz. For example, the photocurable adhesive sheet according to any one of claims 1 to 14, wherein the storage modulus (Y) of the adhesive layer (Y) after irradiation with light having a cumulative light amount of 3000 (mJ / cm ² ) at a wavelength of 405 nm ( G ') is 2.0 × 10 ⁴ Pa or higher at a temperature of 120 ° C. and a frequency of 1 Hz. The photocurable adhesive sheet according to any one of claims 1 to 16, wherein the above-mentioned adhesive layer (Y) has a hot-melt property that softens or even flows by heating. For example, the light-curable adhesive sheet according to any one of claims 1 to 17, which is used for bonding 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. An adhesive sheet of the resin member (X). A light-curable adhesive sheet laminate having the light-curable adhesive sheet according to any one of claims 1 to 17 and a light transmittance of 10% or less at a wavelength of 365 nm and a light at a wavelength of 405 nm A resin member (X) having a transmittance of 60% or more is laminated. For example, the photocurable adhesive sheet laminate of claim 19, wherein the photocurable adhesive sheet is composed of a single layer or a multilayer of two or more layers, and the adhesive layer (Y) ) Has photohardenability: the gel fraction (referred to as "gel fraction X1 before light irradiation") is 0 to 60% and the resin member (X) is interposed from the outside of the resin member (X) When the light with a wavelength of 405 nm is irradiated, the difference in gel fraction increases by more than 10%. For example, the photocurable adhesive sheet laminate of claim 19 or 20, wherein the adhesive layer (Y) of the photocurable adhesive sheet has the following photocurability: it is separated from the outside of the resin member (X) When the resin member (X) is irradiated with light having a cumulative light amount of 3000 (mJ / cm ² ) at a wavelength of 405 nm, the gel fraction (gel fraction X1 before light irradiation) and the gel fraction after light irradiation The difference between the gel fractions (called "gel fractions after light irradiation X2") (gel fractions after light irradiation X2-gel fractions before light irradiation X1) is 10% or more. The photocurable adhesive sheet laminate according to any one of claims 19 to 21, wherein the resin member (X) is a member containing a polycarbonate resin or an acrylic resin as a main component resin. For example, the photocurable adhesive sheet laminate according to any one of claims 19 to 22, wherein a cumulative light amount at 405 nm from the resin member (X) is 3,000 (mJ / cm ² ), the storage modulus (G ') of the adhesive layer (Y) in the photo-curable adhesive sheet after light irradiation becomes 0.7 × 10 ⁴ Pa or higher at a temperature of 120 ° C. and a frequency of 1 Hz. For example, the photocurable adhesive sheet laminate according to any one of claims 19 to 23, wherein the cumulative light amount at 405 nm is 3,000 (mJ / cm ² ), the storage modulus (G ') of the adhesive layer (Y) in the photocurable adhesive sheet after light irradiation becomes 2.0 × 10 ⁴ Pa or higher at a temperature of 120 ° C. and a frequency of 1 Hz. A method for producing a photocurable adhesive sheet laminate, which is characterized in that it is the method for producing a photocurable adhesive sheet laminate according to any one of claims 19 to 24, and (meth) acrylic acid is used. A resin composition of an ester (co) polymer and a visible light initiator to produce the photocurable adhesive sheet, and the photocurable adhesive sheet is laminated on the resin member (X). A method for manufacturing an image display panel laminate, comprising: a photocurable adhesive sheet laminate having a photocurable adhesive sheet according to any one of claims 19 to 24; and an image display panel. (P) A method for manufacturing a laminated body of an image display panel formed by bonding, and laminating a resin member (X) and an image display panel (P) through the photocurable adhesive sheet, and from the resin member (X) The resin member (X) is irradiated with light having a wavelength of 405 nm through the resin member (X) to harden the adhesive layer (Y) of the photocurable adhesive sheet, thereby curing the resin member (X) and the image display panel (P). )fit.