JP6769461B2 - Adhesive sheet, adhesive sheet with release sheet, adhesive sheet with transparent film, laminate and manufacturing method of laminate - Google Patents

Description

The present invention relates to an adhesive sheet, an adhesive sheet with a release sheet, an adhesive sheet with a transparent film, a laminate, and a method for producing the laminate.

Conventionally, a display device such as a liquid crystal display (LCD) and an input device used in combination with a display device such as a touch panel have been widely used. In the manufacture of these display devices and input devices, transparent adhesive sheets are used for bonding optical members, and transparent adhesive sheets are also used for bonding display devices and input devices. ..

It is known that there are several polymerization methods for the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive sheet, as described below. Specifically, two steps of (1) polymerization by heat, (2) polymerization by active energy rays, (3) polymerization by heat (or active energy rays), and then polymerization by active energy rays (or heat). There are methods such as polymerization and (4) two-stage polymerization in which polymerization is carried out by active energy rays after polymerization by active energy rays.

In recent years, as a method for forming an adhesive sheet used for the above-mentioned applications, (3) polymerization by heat (or active energy ray) and then polymerization by active energy ray (or heat) is performed by two-stage polymerization. A curing method may be used. Since such a pressure-sensitive adhesive sheet is formed from, for example, a pressure-sensitive adhesive composition having both thermosetting property and active energy ray-curing property (hereinafter, may be referred to as "dual-curing type pressure-sensitive adhesive composition"). It has thermosetting property and active energy ray curable property. Therefore, it can be temporarily adhered by performing only thermosetting, for example, before being bonded to the adherend, and then further cured by active energy rays (referred to as post-curing or after-cure). Can be firmly adhered to the body.

For example, Patent Document 1 describes a base polymer (A) containing a non-crosslinkable (meth) acrylic acid ester unit (a1) and an acrylic monomer unit (a2) having a crosslinkable functional group, and a lauryl acrylate (b1). A monomer (B) containing the above, a cross-linking agent (C) that reacts with the base polymer (A) by heat, and a polymerization initiator (D) that initiates the polymerization reaction of the monomer (B) by irradiation with active energy rays. ) And the solvent (E), and a pressure-sensitive adhesive sheet containing a pressure-sensitive adhesive layer obtained by semi-curing the pressure-sensitive adhesive composition by heating is described.
In Patent Document 2, glass plates are bonded to each other, glass plates and synthetic resin plates or synthetic resin plates are bonded to each other, and a pressure-sensitive adhesive sheet having at least one UV-curable pressure-sensitive adhesive layer is used. A method for producing a transparent laminate in which the pressure-sensitive adhesive layer is cured by ultraviolet rays by irradiating with ultraviolet rays from the side is described.

Japanese Unexamined Patent Publication No. 2016-084391 Japanese Unexamined Patent Publication No. 2012-031059

As a result of examining the characteristics of the pressure-sensitive adhesive sheet described in Patent Documents 1 and 2, the present inventors may not sufficiently exhibit high-temperature durability when trying to improve workability of the pressure-sensitive adhesive sheet after post-curing. I understood.
Therefore, in order to solve the problems of the prior art, the present inventors have proceeded with studies for the purpose of improving the high temperature durability of the adhesive sheet having post-curability and processability.

As a result of diligent studies to solve the above problems, the present inventors have conducted cross-linking acrylic polymers, cross-linking agents, polyfunctional monomers having two or more reactive double bonds in the molecule, and molecules. In a pressure-sensitive adhesive composition containing a monofunctional monomer having one reactive double bond and a polymerization initiator, the alkoxyalkyl group-containing (meth) acrylate is used as a monomer constituting the crosslinkable acrylic polymer. , When the semi-cured pressure-sensitive adhesive layer is post-cured by using hydroxy group-containing (meth) acrylate and methyl (meth) acrylate and setting the proportion occupied by the alkoxyalkyl group-containing (meth) acrylate within a predetermined range. It has been found that an adhesive sheet capable of exhibiting excellent high temperature durability can be obtained.
Specifically, the present invention has the following configuration.

[1] An adhesive sheet having an adhesive layer in which the adhesive composition is in a semi-cured state.
The pressure-sensitive adhesive composition is a crosslinkable acrylic polymer, a crosslinker, a polyfunctional monomer having two or more reactive double bonds in the molecule, and a monofunctional monomer having one reactive double bond in the molecule. And contains a polymerization initiator,
The crosslinkable acrylic polymer contains a unit derived from an alkoxyalkyl group-containing (meth) acrylate, a unit derived from a hydroxy group-containing (meth) acrylate, and a unit derived from a methyl (meth) acrylate.
A pressure-sensitive adhesive sheet in which the content of a unit derived from an alkoxyalkyl group-containing (meth) acrylate is 50 to 90% by mass with respect to the total mass of the crosslinkable acrylic polymer.
[2] The pressure-sensitive adhesive sheet according to [1], wherein the polyfunctional monomer has a bisphenol skeleton in one molecule.
[3] The polyfunctional monomer has an alkylene glycol group in one molecule, and the glass transition temperature (Tg) of the homopolymer when the polyfunctional monomer is polymerized is 150 ° C. or lower [1]. ] The adhesive sheet described in.
[4] The crosslinkable acrylic polymer further contains units derived from the nitrogen-containing monomer, and the content of the carboxy group-containing monomer unit with respect to the total mass of the crosslinkable acrylic polymer is 0.1% by mass or less. The adhesive sheet according to any one of [1] to [3].
[5] The pressure-sensitive adhesive sheet according to any one of [1] to [4], wherein when the pressure-sensitive adhesive layer is post-cured, the gel fraction after post-curing is 65 to 100% by mass.
[6] The gel fraction of the pressure-sensitive adhesive layer in the semi-cured state is 10% by mass or more and less than 70% by mass, and
The pressure-sensitive adhesive sheet according to any one of [1] to [5], wherein when the pressure-sensitive adhesive layer is post-cured, the gel fraction after post-curing is 10% by mass or more higher than the gel fraction in the semi-cured state.
[7] The pressure-sensitive adhesive sheet according to any one of [1] to [6], wherein the cross-linking agent is a bifunctional or higher functional isocyanate compound.
[8] The method according to any one of [1] to [7], wherein the total content of the monofunctional monomer and the polyfunctional monomer is 6 to 50 parts by mass with respect to 100 parts by mass of the crosslinkable acrylic polymer. Adhesive sheet.
[9] The pressure-sensitive adhesive sheet according to any one of [1] to [8], wherein the content of the polyfunctional monomer is 5 to 30 parts by mass with respect to 100 parts by mass of the crosslinkable acrylic polymer.
[10] The pressure-sensitive adhesive sheet according to any one of [1] to [9], wherein the monofunctional monomer is an alkyl (meth) acrylate.
[11] The pressure-sensitive adhesive sheet according to any one of [1] to [10], wherein the polymerization initiator initiates the polymerization of the polyfunctional monomer and / or the monofunctional monomer by irradiation with active energy rays.
[12] An adhesive sheet with a release sheet, comprising a pair of release sheets having different peeling forces on both surfaces of the adhesive sheet according to any one of [1] to [11].
[13] At least one selected from a polyethylene terephthalate film, an acrylic film, a polycarbonate film, a triacetyl cellulose film, and a cycloolefin polymer film on at least one surface of the pressure-sensitive adhesive sheet according to any one of [1] to [11]. Adhesive sheet with transparent film with transparent film.
[14] An adhesive layer after curing after irradiating the adhesive layer of the adhesive sheet according to any one of [1] to [11] with active energy rays and post-curing, and an adhesive layer after post-curing. A laminated body having an adherend on at least one surface side of the above.
[15] After the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to any one of [1] to [11] is attached to the adherend in a semi-cured state, the pressure-sensitive adhesive layer is rearranged by irradiating with active energy rays. A method for producing a laminate, which includes a step of curing.

According to the present invention, high temperature durability can be enhanced in a pressure-sensitive adhesive sheet having post-curability and processability.

FIG. 1 is a schematic view showing a cross section of a release sheet or an adhesive sheet having a base material. FIG. 2 is a diagram illustrating a method for measuring a constant load peeling distance. FIG. 3 is a schematic view showing a cross section of an example of the laminated body of the present invention. FIG. 4 is a schematic view showing a cross section of another example of the laminated body of the present invention.

Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be based on typical embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, the numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.

In addition, in this specification, "(meth) acrylate" represents both acrylate and methacrylate, or either, and "(meth) acrylic acid" represents both acrylic acid and methacrylic acid, or either.
Further, in the present specification, "monomer" and "monomer" are synonymous, and "polymer" and "polymer" are synonymous.

<Adhesive sheet>
The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer in which the pressure-sensitive adhesive composition is in a semi-cured state. Here, the pressure-sensitive adhesive composition is a cross-linking acrylic polymer, a cross-linking agent, a polyfunctional monomer having two or more reactive double bonds in the molecule, and a monofunctional one having one reactive double bond in the molecule. Contains a monomer and a polymerization initiator. The crosslinkable acrylic polymer contains a unit derived from an alkoxyalkyl group-containing (meth) acrylate, a unit derived from a hydroxy group-containing (meth) acrylate, and a unit derived from a methyl (meth) acrylate, and has a crosslinkable acrylic weight. The content of the unit derived from the alkoxyalkyl group-containing (meth) acrylate with respect to the total mass of the coalescence is 50 to 90% by mass.

With the above configuration, in the present invention, high temperature durability can be enhanced in a pressure-sensitive adhesive sheet having post-curability and processability. In the present specification, a triacetyl cellulose film is attached to one surface of the pressure-sensitive adhesive sheet, and a polycarbonate plate is attached to the other surface, which is then cured and then left at 105 ° C. for 240 hours in a dry environment. Even if there is, it can be determined that the adhesive sheet is excellent in high temperature durability when it is suppressed from floating or peeling from the polycarbonate plate.

Further, in the pressure-sensitive adhesive sheet of the present invention, stickiness of the end face after post-curing is suppressed, and for example, it is possible to prevent the pressure-sensitive adhesive from adhering to the punching blade during the punching process and the resulting deformation of the pressure-sensitive adhesive layer. .. Further, the pressure-sensitive adhesive sheet of the present invention is also excellent in processability after post-curing.

<Structure of adhesive sheet>
The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer. The pressure-sensitive adhesive sheet may be a single-layer pressure-sensitive adhesive sheet composed of only the pressure-sensitive adhesive layer. Further, the adhesive sheet may be a single-sided adhesive sheet having a base material (preferably a transparent base material) on one side, or a double-sided pressure-sensitive adhesive sheet. The double-sided adhesive sheet includes a single-layer adhesive sheet composed of an adhesive layer, a multi-layer adhesive sheet in which a plurality of adhesive layers are laminated, and a multi-layer adhesive in which another adhesive layer is laminated between the adhesive layers. A multi-layered pressure-sensitive adhesive sheet in which a support is laminated between a sheet, a pressure-sensitive adhesive layer and a pressure-sensitive adhesive layer, and a multi-layered pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer is laminated on one side of the support and another pressure-sensitive adhesive layer is laminated on the other side. Can be mentioned. When the double-sided adhesive sheet has a support, it is preferable to use a transparent support as the support. As the support, a general film used in the optical field can be used as in the case of the transparent substrate. Since such a double-sided pressure-sensitive adhesive sheet is also excellent in transparency of the pressure-sensitive adhesive sheet as a whole, it can be suitably used for bonding optical members to each other.

When the pressure-sensitive adhesive sheet of the present invention is a single-sided pressure-sensitive adhesive sheet, as shown in FIG. 1, a transparent base material 12a may be provided on one side of the pressure-sensitive adhesive layer 11. In this case, it is preferable that the other surface of the pressure-sensitive adhesive layer 11 is covered with the release sheet 12b. When using an adhesive sheet, the release sheet 12b may be peeled off and attached to the desired adherend so that the adhesive layer 11 adheres to the desired adherend, and then post-cured by irradiating with active energy rays or the like. preferable. As the transparent base material, a general film used in the optical field such as a polyethylene terephthalate film, an acrylic film, a polycarbonate film, a triacetyl cellulose film, and a cycloolefin polymer film can be used. Further, an easy-adhesion layer may be provided on the pressure-sensitive adhesive layer side of these transparent substrates. Further, a functional layer such as a hard coat layer, an antireflection layer, an antifouling layer, and an ultraviolet absorbing layer may be provided on the opposite surface of the adhesive layer of the transparent base material.

The present invention may relate to an adhesive sheet with a release sheet having release sheets on both surfaces of the adhesive sheet. When the release sheets are provided on both surfaces of the pressure-sensitive adhesive sheet of the present invention, it is preferable to have the release sheets 12a and 12b on both surfaces of the pressure-sensitive adhesive layer 11 as shown in FIG.

The release sheet is a releaseable laminated sheet having a release sheet base material and a release agent layer provided on one side of the release sheet base material, or a polyolefin film such as a polyethylene film or polypropylene film as a low polarity base material. Can be mentioned.
Papers and polymer films are used as the base material for the release sheet in the releaseable laminated sheet. As the release agent constituting the release agent layer, for example, a general-purpose addition-type or condensation-type silicone-based release agent or a long-chain alkyl group-containing compound is used. In particular, an addition type silicone release agent having high reactivity is preferably used.
Specific examples of the silicone-based release agent include BY24-4527 and SD-7220 manufactured by Toray Dow Corning Silicone Co., Ltd., and KS-3600, KS-774, and X62-2600 manufactured by Shin-Etsu Chemical Co., Ltd. Can be mentioned. Further, the silicone-based release agent may contain a silicone resin which is an organic silicon compound having ₂ units of SiO and (CH ₃ ) ₃ SiO _1/2 units or CH ₂ = CH (CH ₃ ) SiO _1/2 units. preferable. Specific examples of the silicone resin include BY24-843, SD-7292, SHR-1404, etc. manufactured by Toray Dow Corning Silicone Co., Ltd., KS-3800, X92-183, etc. manufactured by Shin-Etsu Chemical Co., Ltd.
A commercially available product may be used as the peelable laminated sheet. Examples thereof include a heavy separator film, which is a release-treated polyethylene terephthalate film manufactured by Teijin DuPont Film Co., Ltd., and a light separator film, which is a release-treated polyethylene terephthalate film manufactured by Teijin DuPont Film Co., Ltd. it can.

When the pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet, it is preferable to have a pair of release sheets having different peeling forces. That is, it is preferable that the release sheet has different peelability between the release sheet 12a and the release sheet 12b in order to facilitate the release. When the peelability from one side and the peelability from the other side are different, it becomes easy to peel off only the release sheet having the higher peelability first. In that case, the peelability of the release sheet 12a and the release sheet 12b may be adjusted according to the bonding method and the bonding order.

Further, the present invention may relate to an adhesive sheet with a transparent film having a transparent film on at least one surface of the adhesive sheet. In this case, the transparent film is preferably at least one selected from a polyethylene terephthalate film, an acrylic film, a polycarbonate film, a triacetyl cellulose film and a cycloolefin polymer film. The adhesive sheet with a transparent film may be a sheet in which a transparent film / adhesive sheet / release sheet are laminated in this order.

<Adhesive layer>
The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer in which the pressure-sensitive adhesive composition is in a semi-cured state, and the pressure-sensitive adhesive layer has post-curing property.

Here, in the present specification, when the gel fraction of the pressure-sensitive adhesive layer is increased by 10% by mass or more by irradiating or heating the active energy rays under the following conditions, the pressure-sensitive adhesive layer before irradiation or heating is half. It is assumed that it is in a cured state. In this case, when the pressure-sensitive adhesive layer is post-cured by irradiating it with an active energy ray, an optical transparent PET separator is attached to both surfaces of the pressure-sensitive adhesive layer, and the active energy ray (high-pressure mercury lamp) is applied from the optical transparent PET separator side. Alternatively, a metal halide lamp) is irradiated so that the integrated light intensity is 3000 mJ / cm ² . When the pressure-sensitive adhesive layer is post-cured by heating, heat treatment is performed in an oven at 100 ° C. for 3 hours with separator films bonded to both surfaces of the pressure-sensitive adhesive layer.
Among them, the gel fraction of the pressure-sensitive adhesive layer in the semi-cured state is preferably 10% by mass or more and less than 70% by mass, preferably 12% by mass or more and less than 70% by mass, and is 15 to 65% by mass. It is particularly preferable to have.
The gel fraction of the pressure-sensitive adhesive layer after post-curing is preferably 60 to 100% by mass, more preferably 65 to 100% by mass, and even more preferably 70 to 100% by mass.
The gel fraction of the pressure-sensitive adhesive layer is a value measured by the following method. First, about 0.1 g of an adhesive sheet (adhesive layer) is collected in a sample bottle, 30 ml of ethyl acetate is added, and the mixture is shaken for 24 hours. Then, the contents of this sample bottle are filtered through a 150 mesh stainless steel wire mesh, and the residue on the wire mesh is dried at 100 ° C. for 1 hour to measure the dry mass (g). From the obtained dry mass, the gel fraction is calculated by the following formula 1.
Gel fraction (mass%) = (dry mass / collected mass of adhesive sheet) x 100 ... Equation 1

In the present specification, the "semi-cured state" is preferably a state after thermosetting. Then, it is preferable to "post-cure" by irradiating with active energy rays after that. That is, the "semi-cured state" is preferably a state after thermosetting and is a soft pressure-sensitive adhesive layer before irradiation with active energy rays. The "post-curing" is preferably a step of completely curing the pressure-sensitive adhesive layer with heat or active energy rays, and more preferably a step of completely curing the pressure-sensitive adhesive layer with active energy rays. That is, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention is preferably in a semi-cured state by thermosetting the pressure-sensitive adhesive composition, and preferably has active energy ray curability.

When the pressure-sensitive adhesive layer is post-cured, the pressure-sensitive adhesive sheet preferably satisfies the following physical properties (1).
Physical properties (1): The probe tack value measured at 23 ° C. and under the following measurement conditions is 10 N / 5 mmφ or less.
(Measurement conditions for probe tack value)
Measuring equipment: NS probe tack tester (manufactured by Nichiban Co., Ltd.)
Probe diameter: 5 mmφ
Probe base material: Stainless steel surface finish AA # 400 Mirror surface weight by polishing: 19.6 ± 0.2 g (made of brass)
Probe moving speed: 1.0 cm / sec Duel time: 1 sec

The probe tack value of the pressure-sensitive adhesive sheet measured at 23 ° C. and under the above measurement conditions is more preferably 9 N / 5 mmφ or less, and further preferably 8 N / 5 mmφ or less. The lower limit of the probe tack value of the adhesive sheet measured at 23 ° C. and the above measurement conditions is not particularly limited, but may be, for example, 0.01 N / 5 mmφ or more.

Further, when the pressure-sensitive adhesive layer is post-cured, the pressure-sensitive adhesive sheet preferably satisfies the following physical properties (2).
Physical properties (2): The constant load peeling distance at 23 ° C. measured under the following measurement condition (a) is 20 mm or less, and the constant load peeling distance at 85 ° C. measured under the following measurement condition (b) is 100 mm or less. ..
(Measurement condition (a))
Of the adhesive surface of the adhesive sheet having a width of 25 mm and a length of 100 mm, a region having a width of 25 mm and a length of 75 mm is attached to the adherend and post-cured. In an environment of 23 ° C., the adherend is fixed in the horizontal direction so that the non-bonded region of the adhesive sheet hangs downward. A load of 300 g is applied to the end portion of the non-bonded region of the adhesive sheet in the length direction for 30 minutes, and the distance at which the bonded region of the adhesive sheet is peeled off from the adherend during this period is measured as a constant load peeling distance at 23 ° C.
(Measurement condition (b))
Of the adhesive surface of the adhesive sheet having a width of 25 mm and a length of 100 mm, a region having a width of 25 mm and a length of 75 mm is attached to the adherend and post-cured. In an environment of 85 ° C., the adherend is fixed in the horizontal direction so that the non-bonded region of the adhesive sheet hangs downward. A load of 100 g is applied to the end portion of the non-bonded region of the adhesive sheet in the length direction for 10 minutes, and the distance at which the bonded region of the adhesive sheet is separated from the adherend during this period is measured as a constant load peeling distance at 85 ° C.

When performing the above measurement, first, a test piece for measurement is prepared by the following method. A triacetyl cellulose film (manufactured by FUJIFILM Corporation, Fujitac TD60UL, thickness 60 μm) is bonded to one surface of the pressure-sensitive adhesive sheet using a hand roller to prepare a laminated film. This laminated film is cut into a size of 25 mm in width and 100 mm in length, and then a region of 25 mm in width and 75 mm in length of the other side of the adhesive sheet having a width of 25 mm and a length of 100 mm is covered with an adherend (hard). Polycarbonate plate with coat layer: Made by Mitsubishi Gas Chemical Company, Iupilon MR58 (thickness 1 mm) is attached to the hard coat surface side using a 2 kg crimping roller. In this state, it is held in an autoclave under the conditions of 40 ° C. and 5 atm for 30 minutes to be brought into close contact with the adherend. Two such test pieces are prepared.
Under the above measurement conditions, when performing post-curing, ultraviolet rays are irradiated from the triacetyl cellulose film side of the test piece for measurement so that the integrated light intensity is 3000 mJ / cm ^2, and the temperature is 23 ° C. and the relative humidity is 50%. Leave for 24 hours in the environment of.

For one of the test pieces, as shown in FIG. 2, in an environment of 23 ° C., in the length direction of the non-bonded region (width 25 mm, length 25 mm) of the laminated film composed of the adhesive sheet 1 and the triacetyl cellulose film 30. A 300 g weight 34 is hung at the end, a load of 300 g is applied in the direction of 90 ° to the plane of the adherend 32, and the film is left in that state for 30 minutes. During that time, the length L (constant load peeling distance) of the portion where the laminated film is peeled off is measured (constant load peeling distance under the measurement condition (a)).
The other test piece was left in an environment of 85 ° C. for 30 minutes, and then in an environment of 85 ° C., as shown in FIG. 2, the end portion in the length direction of the non-bonded region (width 25 mm, length 25 mm) of the laminated film. A 100 g weight 34 is hung on the surface, a load of 100 g is applied in the direction of 90 ° to the plane of the adherend 32, and the mixture is left in that state for another 10 minutes. During that time, the length L (constant load peeling distance) of the portion where the laminated film is peeled off is measured (constant load peeling distance under the measurement condition (b)).

The constant load peeling distance at 23 ° C. measured under the measurement condition (a) is preferably 10 mm or less, and more preferably 5 mm or less. The constant load peeling distance at 23 ° C. measured under the measurement condition (a) may be 0 mm. The constant load peeling distance at 85 ° C. measured under the measurement condition (b) is preferably 80 mm or less, more preferably 70 mm or less, further preferably 50 mm or less, and more preferably 30 mm or less. More preferably, it is more preferably 20 mm or less, and particularly preferably 10 mm or less. The constant load peeling distance at 85 ° C. measured under the measurement condition (b) may be 0 mm.

When the pressure-sensitive adhesive layer is in a semi-cured state, the probe tack value measured at 23 ° C. and the above-mentioned measurement conditions is preferably 1.0 N / 5 mmφ or more, and more preferably 5.0 N / 5 mmφ or more. It is more preferably 10.0 N / 5 mmφ or more, further preferably 50.0 N / 5 mmφ or more, and particularly preferably 100.0 N / 5 mmφ or more. When the pressure-sensitive adhesive layer is in a semi-cured state, the probe tack value measured at 23 ° C. and under the above-mentioned measurement conditions is preferably 1000.0 N / 5 mmφ or less.

The thickness of the pressure-sensitive adhesive layer can be appropriately set depending on the intended use, and is not particularly limited, but is preferably 5 to 500 μm, more preferably 10 to 300 μm, and particularly preferably 12 to 100 μm. By setting the thickness of the pressure-sensitive adhesive layer within the above range, it is possible to prevent the pressure-sensitive adhesive from sticking out and stickiness, so that workability can be improved. Further, by setting the thickness of the pressure-sensitive adhesive layer within the above range, the production of a double-sided pressure-sensitive adhesive sheet becomes easy.

<Adhesive composition>
The pressure-sensitive adhesive layer described above is a semi-cured state of the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition used in the present invention is a dual-curable pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition is a cross-linking acrylic polymer, a cross-linking agent, a polyfunctional monomer having two or more reactive double bonds in the molecule, and a monofunctional monomer having one reactive double bond in the molecule. And contains a polymerization initiator. Here, the crosslinkable acrylic polymer contains a unit derived from an alkoxyalkyl group-containing (meth) acrylate, a unit derived from a hydroxy group-containing (meth) acrylate, and a unit derived from methyl (meth) acrylate, and is crosslinked. The content of the unit derived from the alkoxyalkyl group-containing (meth) acrylate with respect to the total mass of the sex acrylic polymer is 50 to 90% by mass.

(Crosslinkable acrylic polymer)
The crosslinkable acrylic polymer contains a unit derived from an alkoxyalkyl group-containing (meth) acrylate, a unit derived from a hydroxy group-containing (meth) acrylate, and a unit derived from a methyl (meth) acrylate. In the present specification, the "unit" is a repeating unit (monomer unit) constituting the polymer. The crosslinkable acrylic polymer preferably has transparency to the extent that it does not reduce the visibility of the display device.

<Alkoxyalkyl group-containing (meth) acrylate>
The alkoxyalkyl group-containing (meth) acrylate is an alkoxyalkyl (meth) acrylate. As the alkoxyalkyl (meth) acrylate, for example, an alkoxyalkyl (meth) acrylate having an alkoxy group having 1 to 12 carbon atoms and an alkylene group bonded to the alkoxy group having 1 to 18 carbon atoms is preferable. The alkoxy group preferably has 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and particularly preferably 1 or 2 carbon atoms. The alkylene group bonded to the alkoxy group preferably has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, further preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.

Examples of such alkoxyalkyl (meth) acrylates include 2-methoxymethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxymethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, and the like. Examples thereof include 3-methoxypropyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, and 4-ethoxybutyl (meth) acrylate. Of these, 2-methoxyethyl (meth) acrylate is particularly preferable. By using 2-methoxyethyl (meth) acrylate as the alkoxyalkyl (meth) acrylate, the adhesive layer in the semi-cured state can improve the wettability to the substrate while suppressing stickiness.

The content of the unit derived from the alkoxyalkyl group-containing (meth) acrylate is preferably 50% by mass or more, more preferably 55% by mass or more, based on the total mass of the crosslinkable acrylic polymer. It is more preferably 60% by mass or more. The content of the unit derived from the alkoxyalkyl group-containing (meth) acrylate is preferably 90% by mass or less with respect to the total mass of the crosslinkable acrylic polymer. By setting the content of the unit derived from the alkoxyalkyl group-containing (meth) acrylate within the above range, the adhesive layer in the semi-cured state can easily adhere to the substrate, while the adhesive after post-curing The agent layer has a high hardness, and can further improve high temperature durability and workability.

<Hydroxy group-containing (meth) acrylate>
Examples of the hydroxy group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 3-chloro-2-hydroxypropyl (meth). Examples thereof include acrylate, 4-hydroshikibutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, polyalkylene glycol mono (meth) acrylate and the like. Among them, at least one selected from 2-hydroxyethyl (meth) acrylate and 4-hydroshikibutyl (meth) acrylate is preferably used.

The content of the unit derived from the hydroxy group-containing (meth) acrylate is preferably 5% by mass or more, more preferably 7% by mass or more, based on the total mass of the crosslinkable acrylic polymer. The content of the unit derived from the hydroxy group-containing (meth) acrylate is preferably 35% by mass or less, more preferably 30% by mass or less, based on the total mass of the crosslinkable acrylic polymer. .. By setting the content of the unit derived from the hydroxy group-containing (meth) acrylate within the above range, the adhesion to the adherend can be further enhanced.

<Alkyl (meth) acrylate>
The crosslinkable acrylic polymer contains a unit derived from methyl (meth) acrylate. The content of the unit derived from methyl (meth) acrylate is preferably 5% by mass or more, more preferably 7% by mass or more, based on the total mass of the crosslinkable acrylic polymer. The content of the unit derived from methyl (meth) acrylate is preferably 35% by mass or less, and more preferably 30% by mass or less, based on the total mass of the crosslinkable acrylic polymer.

The crosslinkable acrylic polymer may contain a unit derived from an alkyl (meth) acrylate in addition to a unit derived from the methyl (meth) acrylate. Examples of alkyl (meth) acrylates include ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, and cetyl (meth). Examples thereof include alkyl (meth) acrylates such as meta) acrylates, stearyl (meth) acrylates, and behenyl (meth) acrylates. The content of the unit derived from the alkyl (meth) acrylate other than the methyl (meth) acrylate is preferably 1% by mass or more, preferably 3% by mass or more, based on the total mass of the crosslinkable acrylic polymer. Is more preferable. Further, the content of the unit derived from the alkyl (meth) acrylate other than the methyl (meth) acrylate is preferably 50% by mass or less with respect to the total mass of the crosslinkable acrylic polymer. By setting the content of the unit derived from the alkyl (meth) acrylate other than the methyl (meth) acrylate within the above range, the stickiness (tackiness) can be kept low and the adhesion to the substrate can be improved.

<Nitrogen-containing monomer>
The crosslinkable acrylic polymer preferably further contains a unit derived from the nitrogen-containing monomer. The nitrogen-containing monomer is a monomer containing a nitrogen element in one molecule. Examples of nitrogen-containing monomers include dimethylacrylamide, diethylacrylamide, acryloylmorpholine, hydroxyethylacrylamide, methylolacrylamide, methoxymethylacrylamide, ethoxymethylacrylamide, dimethylaminoethylacrylamide, N-vinylcaprolactam, and N-vinyl-2-. Examples thereof include pyrrolidone, dimethylaminoethyl (meth) acrylate, and N-vinylformamide. Among them, the nitrogen-containing monomer is preferably at least one selected from an acrylamide derivative, an amino group-containing monomer and a nitrogen-containing heterocyclic ring-containing monomer, and more preferably an acrylamide derivative. The acrylamide derivative is more preferably at least one selected from dimethylacrylamide, diethylacrylamide and acryloylmorpholine, and particularly preferably dimethylacrylamide. Since the crosslinkable acrylic polymer contains a unit derived from the nitrogen-containing monomer as described above, the adhesive layer in the semi-cured state easily adheres to the substrate, but after post-curing. The pressure-sensitive adhesive layer has a high hardness, and high-temperature durability and workability can be further improved.

The content of the unit derived from the nitrogen-containing monomer is preferably 1% by mass or more, more preferably 3% by mass or more, based on the total mass of the crosslinkable acrylic polymer. The content of the unit derived from the nitrogen-containing monomer is preferably 20% by mass or less with respect to the total mass of the crosslinkable acrylic polymer.

<Other monomers>
The crosslinkable acrylic polymer may have other monomeric units, if desired. The other monomer may be copolymerizable with the above-mentioned acrylic monomer, and examples thereof include (meth) acrylonitrile, vinyl acetate, styrene, vinyl chloride, vinylpyrrolidone, and vinylpyridine. The content of the other monomer unit in the crosslinkable acrylic polymer is preferably 20% by mass or less, and more preferably 15% by mass or less.

In the crosslinkable acrylic polymer, the content of the carboxy group monomer unit is preferably 0.1% by mass or less, even if it is 0% by mass, based on the total mass of the crosslinkable acrylic polymer. Good. Examples of the carboxy group-containing monomer unit include acrylic acid and methacrylic acid.

<Weight average molecular weight of crosslinkable acrylic polymer>
The weight average molecular weight of the crosslinkable acrylic polymer is preferably 100,000 to 2 million, more preferably 200,000 to 1.5 million. When the weight average molecular weight is within the above range, it is easy to maintain the semi-cured state of the pressure-sensitive adhesive sheet, and it is easy to obtain the hardness after post-curing, and the processability is excellent. The weight average molecular weight of the crosslinkable acrylic polymer is a value before being crosslinked with a crosslinking agent. The weight average molecular weight is a value measured by size exclusion chromatography (SEC) and determined based on polystyrene. As the crosslinkable acrylic polymer, a commercially available one may be used, or one synthesized by a known method may be used.

(Crosslinking agent)
The pressure-sensitive adhesive composition contains a cross-linking agent. The cross-linking agent can be appropriately selected in consideration of the reactivity of the cross-linking acrylic polymer with the cross-linking functional group. For example, it can be selected from known cross-linking agents such as isocyanate compounds, epoxy compounds, oxazoline compounds, aziridine compounds, metal chelate compounds and butylated melamine compounds. Among these, it is preferable to use an isocyanate compound or an epoxy compound because the hydroxy group-containing (meth) acrylate can be easily crosslinked. That is, the cross-linking agent is preferably at least one selected from a bifunctional or higher functional epoxy compound and a bifunctional or higher functional isocyanate compound, and more preferably a bifunctional or higher functional isocyanate compound.

Examples of the isocyanate compound include tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and the like. Examples of commercially available products include tolylene diisocyanate compounds (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L), xylylene diisocyanate compounds (manufactured by Mitsui Chemicals, Inc., Takenate D-110N) and the like.

The content of the cross-linking agent in the pressure-sensitive adhesive composition is appropriately selected according to the desired tackiness and the like, but is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the cross-linking acrylic polymer, and is 0. .1 to 3 parts by mass is more preferable. By setting the content of the cross-linking agent within the above range, the workability can be further improved. As the cross-linking agent, one type may be used alone or two or more types may be used in combination, and when two or more types are used in combination, the total mass is preferably within the above range.

(Polyfunctional monomer)
The pressure-sensitive adhesive composition contains a polyfunctional monomer having two or more reactive double bonds in the molecule. The polyfunctional monomer has two or more reactive double bonds, and among them, the polyfunctional monomer preferably has two or more and less than five reactive double bonds. It is more preferable to have more than four.

The polyfunctional monomer is preferably a polyfunctional monomer having a bisphenol skeleton in one molecule. By using a polyfunctional monomer having a bisphenol skeleton in one molecule, the hardness of the pressure-sensitive adhesive layer after post-curing can be increased more effectively. As a result, the stickiness (tackiness) of the end face of the pressure-sensitive adhesive layer after post-curing can be suppressed to a low level, and the workability of the pressure-sensitive adhesive layer can be improved.

Examples of the polyfunctional monomer having a bisphenol skeleton in one molecule include diacrylate of bisphenol A diglycidyl ether, diacrylate of propoxylated bisphenol A, and diacrylate of bisphenol F diglycidyl ether.

Commercially available products can be used as the polyfunctional monomer. Examples of commercially available products include bifunctional monomer M211B (bisphenol A ethylene oxide-modified diacrylate) manufactured by Toa Synthetic Co., Ltd., bifunctional monomer M08 (bisphenol F ethylene oxide-modified diacrylate) manufactured by Shin-Nakamura Chemical Co., Ltd. , Bifunctional monomer A-BPP-3 (propoxylated bisphenol A diacrylate) and the like.

Further, the polyfunctional monomer may be a polyfunctional monomer having an alkylene glycol group in one molecule. The glass transition temperature (Tg) of the homopolymer when such a polyfunctional monomer is polymerized is preferably 150 ° C. or lower, more preferably 100 ° C. or lower. Further, the glass transition temperature (Tg) of the homopolymer when a polyfunctional monomer having an alkylene glycol group in one molecule is polymerized is preferably −35 ° C. or higher, more preferably −10 ° C. or higher. preferable.

In the present invention, by using a polyfunctional monomer having an alkylene glycol group in one molecule, it is possible to increase the hardness of the pressure-sensitive adhesive layer after post-curing and at the same time impart stress relaxation property to the pressure-sensitive adhesive sheet. It is possible to impart curl resistance while improving workability. Further, by setting the glass transition temperature (Tg) of the homopolymer to 150 ° C. or lower, the stress relaxation property can be further enhanced and the curl resistance can be improved.

The alkylene glycol group contained in the polyfunctional monomer preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and particularly preferably 2 or 3 carbon atoms. That is, the polyfunctional monomer preferably has at least one selected from an ethylene glycol group and a propylene glycol group. The ethylene glycol group is −CH ₂ CH ₂ O−, and the propylene glycol group is −CH ₂ CH ₂ CH ₂ O−.
The polyfunctional monomer may have one alkylene glycol group in one molecule, or may have two or more alkylene glycol groups. The number of alkylene glycol groups in one molecule of the polyfunctional monomer is preferably 1 to 20, and more preferably 1 to 10.

Examples of such a polyfunctional monomer include polyethylene glycol diacrylate and trimethylolpropane propylene oxide-modified triacrylate.

Commercially available products can be used as the polyfunctional monomer. Examples of commercially available products include trifunctional monomer M321 (trimethylolpropane propylene oxide-modified triacrylate, Tg50 ° C.) and bifunctional monomer M240 (polyethylene glycol diacrylate, Tg50 ° C.) manufactured by Toagosei Co., Ltd.

The content of the polyfunctional monomer is preferably 1 to 30 parts by mass, and more preferably 5 to 30 parts by mass with respect to 100 parts by mass of the crosslinkable acrylic polymer. The polyfunctional monomer may be used alone or in combination of two or more, and when two or more are used in combination, the total mass is preferably within the above range. By setting the content of the polyfunctional monomer within the above range, the hardness of the pressure-sensitive adhesive layer after post-curing can be increased more effectively, and the processability of the pressure-sensitive adhesive sheet can be improved.

(Monofunctional monomer)
The pressure-sensitive adhesive composition contains a monofunctional monomer having one reactive double bond in the molecule. The glass transition temperature (Tg) of the homopolymer when the monofunctional monomer is polymerized is preferably 50 ° C. or higher and lower than 200 ° C.

The glass transition temperature (Tg) of the homopolymer when the monofunctional monomer is polymerized is preferably higher than 50 ° C, more preferably 55 ° C or higher, and even more preferably 60 ° C or higher. The glass transition temperature (Tg) of the homopolymer when the monofunctional monomer is polymerized is preferably 180 ° C. or lower, more preferably 150 ° C. or lower.

Examples of the monofunctional monomer include isobornyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, benzyl methacrylate, N-acryloyloxyethyl hexahydrophthalimide, acrylamide, N, N-dimethylacrylamide, N, N-diethyl. Acrylamide, acryloylmorpholin, vinylpyrrolidone and the like can be mentioned. Among them, the monofunctional monomer is preferably an alkyl (meth) acrylate, and preferably an isobornyl acrylate. Examples of commercially available products of monofunctional monomers include IBXA manufactured by Osaka Organic Chemical Industry Co., Ltd.

The content of the monofunctional monomer is preferably 1 to 30 parts by mass, and more preferably 2 to 30 parts by mass with respect to 100 parts by mass of the crosslinkable acrylic polymer. The monofunctional monomer may be used alone or in combination of two or more, and when two or more are used in combination, the total mass is preferably within the above range.

The total content of the monofunctional monomer and the polyfunctional monomer is preferably 6 to 50 parts by mass, more preferably 10 to 45 parts by mass with respect to 100 parts by mass of the crosslinkable acrylic polymer. It is preferably 15 to 40 parts by mass, and more preferably 15 to 40 parts by mass. By setting the total content of the monofunctional monomer and the polyfunctional monomer within the above range, stickiness of the end face is suppressed after post-curing, and a pressure-sensitive adhesive sheet having excellent workability can be obtained. Further, by setting the total content of the monofunctional monomer and the polyfunctional monomer within the above range, the high temperature durability of the pressure-sensitive adhesive sheet after post-curing can be more effectively enhanced.

(Polymerization initiator)
The pressure-sensitive adhesive composition contains a polymerization initiator. The polymerization initiator preferably initiates the polymerization of the polyfunctional monomer and / or the monofunctional monomer by irradiation with active energy rays, and the polyfunctional monomer and the monofunctional monomer by irradiation with active energy rays. More preferably, it initiates polymerization of the body. As the polymerization initiator, for example, a known one such as a photopolymerization initiator can be used.
Here, the "active energy ray" means an electromagnetic wave or a charged particle beam having an energy quantum, and examples thereof include ultraviolet rays, electron beams, visible rays, X-rays, and ion rays. Among them, from the viewpoint of versatility, ultraviolet rays or electron beams are preferable, and ultraviolet rays are particularly preferable.

Examples of the polymerization initiator include acetophenone-based initiators, benzoin ether-based initiators, benzophenone-based initiators, hydroxyalkylphenone-based initiators, thioxanthone-based initiators, amine-based initiators, acylphosphine oxide-based initiators, and the like. Be done.
Specific examples of the acetophenone-based initiator include diethoxyacetophenone and benzyl dimethyl ketal.
Specific examples of the benzoin ether-based initiator include benzoin and benzoin methyl ether.
Specific examples of the benzophenone-based initiator include benzophenone, methyl o-benzoylbenzoate and the like.
Specific examples of the hydroxyalkylphenone-based initiator include 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF Japan Ltd., commercially available as IRGACURE184) and the like.
Specific examples of the thioxanthone-based initiator include 2-isopropylthioxanthone, 2,4-dimethylthioxanthone and the like.
Specific examples of the amine-based initiator include triethanolamine, ethyl 4-dimethylbenzoate and the like.
Specific examples of the acylphosphine oxide-based initiator include phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide (manufactured by BASF Japan Ltd., commercially available as IRGACURE819).

The content of the polymerization initiator in the pressure-sensitive adhesive composition is appropriately selected according to the content of the monomer, the irradiation amount of active energy rays at the time of post-curing, and the like. Specifically, it is preferably 0.05 to 10% by mass, more preferably 0.1 to 5.0% by mass, based on the total mass of the monomer. If it is at least the above lower limit value, the hardness can be adjusted to a desired level by post-curing, so that workability is excellent. When it is not more than the above upper limit value, the molecular weight after post-curing is not reduced and the processability is excellent. As the polymerization initiator, one type may be used alone or two or more types may be used in combination, and when two or more types are used in combination, the total mass is preferably within the above range.

(solvent)
The pressure-sensitive adhesive composition may contain a solvent. In this case, the solvent is used to improve the coating suitability of the pressure-sensitive adhesive composition. Examples of the solvent include hydrocarbons such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane and methylcyclohexane; halogenated hydrocarbons such as dichloromethane, trichloroethane, trichloroethylene, tetrachloroethylene and dichloropropane; methanol, ethanol, Alcohols such as propanol, isopropyl alcohol, butanol, isobutyl alcohol, diacetone alcohol; ethers such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone, cyclohexanone; methyl acetate , Ethyl acetate, butyl acetate, isobutyl acetate, amyl acetate, ethyl butyrate, etc .; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene Examples thereof include polyols such as glycol monomethyl ether acetate and derivatives thereof.

The content of the solvent in the pressure-sensitive adhesive composition is not particularly limited, but is preferably 25 to 500 parts by mass, more preferably 30 to 400 parts by mass with respect to 100 parts by mass of the crosslinkable acrylic polymer.
The content of the solvent is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, based on the total mass of the pressure-sensitive adhesive composition. One type of solvent may be used alone, two or more types may be used in combination, and when two or more types are used in combination, the total mass is preferably within the above range.

(Plasticizer)
The pressure-sensitive adhesive composition may further contain a plasticizer as long as the effects of the present invention are not impaired. When the pressure-sensitive adhesive composition contains a plasticizer, the pressure-sensitive adhesive sheet can fill the step formed on the adherend, and the step-following property is enhanced. The plasticizer is preferably a non-functional acrylic polymer. As the non-functional group acrylic polymer, a polymer consisting only of an acrylic monomer unit having no functional group other than an acrylate group, or an acrylic monomer unit having no functional group other than an acrylate group and having no functional group. Examples thereof include polymers composed of non-acrylic monomer units. Since the non-functional group acrylic polymer is not crosslinked, the step followability can be improved without affecting the adhesiveness.
Examples of the acrylic monomer unit having no functional group other than the acrylate group include non-crosslinkable alkyl (meth) acrylate. Examples of the non-acrylic monomer unit having no functional group include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, and stear. Examples thereof include vinyl carboxylic acid esters such as vinyl acetate, vinyl cyclohexanecarboxylate, vinyl benzoate, and styrene.

(Other ingredients)
The pressure-sensitive adhesive composition may contain components other than the above as long as the effects of the present invention are not impaired. Examples of other components include components known as additives for adhesives. For example, an antioxidant, a metal corrosion inhibitor, a tackifier, a silane coupling agent, an ultraviolet absorber, a light stabilizer such as a hindered amine compound, and the like can be selected as necessary. Further, dyes and pigments may be added for the purpose of coloring.
Examples of the antioxidant include a phenol-based antioxidant, an amine-based antioxidant, a lactone-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, and the like. One type of these antioxidants may be used alone, or two or more types may be used in combination.
As the metal corrosion inhibitor, a benzodiazole-based resin can be mentioned as a preferable example because of the compatibility and high effect of the pressure-sensitive adhesive.
Examples of the tackifier include rosin-based resin, terpene-based resin, terpene phenol-based resin, Kumaron inden-based resin, styrene-based resin, xylene-based resin, phenol-based resin, and petroleum resin.
Examples of the silane coupling agent include a mercaptoalkoxysilane compound (for example, a mercapto group-substituted alkoxy oligomer).
Examples of the ultraviolet absorber include benzotriazole-based compounds and benzophenone-based compounds. However, when ultraviolet rays are used for the active energy rays during post-curing, it is preferable to add them within a range that does not inhibit the polymerization reaction.

<Manufacturing method of adhesive sheet>
The method for producing an adhesive sheet of the present invention includes a step of applying the above-mentioned pressure-sensitive adhesive composition on a release sheet to form a coating film, and a step of heating the coating film to make a cured product in a semi-cured state. Is preferable. By heating the coating film, the reaction between the crosslinkable acrylic polymer and the crosslinker proceeds to form a cured product (adhesive layer) in a semi-cured state. That is, during heating, the polymerization reaction of the monomer by the polymerization initiator does not proceed in the coating film, or even if it progresses, it is slight, so that the single amount contained in the pressure-sensitive adhesive composition is contained in the pressure-sensitive adhesive layer. At least a part of the body and the polymerization initiator is contained in an unreacted state. The pressure-sensitive adhesive sheet of the present invention preferably has post-curability and active energy ray-curability.
In order to bring the pressure-sensitive adhesive composition into a semi-cured state, it is preferable to perform an aging treatment in which the pressure-sensitive adhesive sheet is allowed to stand at a constant temperature for a certain period of time after the solvent is removed after coating. The aging treatment can be performed, for example, by allowing it to stand at 23 ° C. for 7 days.

The semi-cured pressure-sensitive adhesive layer can be post-cured by irradiating an adherend such as a base material with active energy rays. That is, the pressure-sensitive adhesive sheet of the present invention is a two-step curing type pressure-sensitive adhesive sheet, has a pressure-sensitive adhesive layer semi-cured only by heat before bonding, and the pressure-sensitive adhesive layer is post-cured by active energy rays after bonding. Will be done.

The coating of the pressure-sensitive adhesive composition can be carried out using a known coating device. Examples of the coating device include a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a micro gravure coater, a rod blade coater, a lip coater, a die coater, a curtain coater and the like.

A known heating device such as a heating furnace or an infrared lamp can be used for heating the coating film formed by applying the pressure-sensitive adhesive composition.

<How to use the adhesive sheet>
In the method of using the pressure-sensitive adhesive sheet of the present invention, it is preferable that the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is brought into contact with the surface of the adherend. In the method of using the pressure-sensitive adhesive sheet, it is preferable that the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is adhered to an adherend when it is in a semi-cured state and irradiated with active energy rays to post-cure the pressure-sensitive adhesive layer.

<Use of adhesive sheet>
The pressure-sensitive adhesive sheet of the present invention is preferably used for an optical member that requires durability, particularly an application that has a complicated shape and requires punching after forming a laminated body.
It is preferable that the pressure-sensitive adhesive sheet of the present invention can suppress the generation of air bubbles even when it is attached to an adherend such as a base material, post-cured, and then exposed to a high humidity and heat environment. The pressure-sensitive adhesive sheet of the present invention is preferably a pressure-sensitive adhesive sheet used for sticking to a base material, and more preferably a pressure-sensitive adhesive sheet used for sticking to a polycarbonate base material. Examples of the polycarbonate base material include PC-1151 manufactured by Teijin Chemicals Ltd.

The pressure-sensitive adhesive sheet of the present invention is preferably a pressure-sensitive adhesive sheet used for direct bonding to a base material, but may be used for indirectly bonding to a base material. For example, it may be bonded to a multilayer base material including a polycarbonate base material. Such a multilayer base material is preferably a base material having a polycarbonate layer and a hard coat layer. The composition of the hard coat layer is preferably selected from acrylic, urethane, silicone, melamine, and epoxy, and more preferably acrylic and silicone. The composition of the hard coat layer is more preferably acrylic from the viewpoint of processability and hardness.
As the multilayer base material containing the polycarbonate base material, for example, MR-58 or IMR05 manufactured by Mitsubishi Gas Chemical Company, Inc. can be used. Here, the composition of MR-58 is HC (hard coat) / PMMA (polymethyl methacrylate) / PC (polycarbonate) / HC (hard coat). The overall thickness of MR-58 is preferably 0.3 mm to 1.2 mm, and the thickness of one hard coat layer is preferably 0.0005 mm to 0.02 mm. The composition of IMR05 is HC (hard coat) / PC (polycarbonate).

Further, the adhesive sheet of the present invention can suppress the occurrence of air bubbles and peeling even when it is attached to an optical member such as a polarizing plate, post-cured, and then exposed to a high humidity and heat environment. .. Here, the polarizing plate includes a polarizer and a polarizer protective film, and the pressure-sensitive adhesive sheet of the present invention is preferably bonded to the polarizer protective film. The polarizer protective film includes a cycloolefin resin film, a cellulose acetate resin film such as triacetyl cellulose and diacetyl cellulose, a polyester resin film such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, a polycarbonate resin film, and acrylic. Examples thereof include a based resin film and a polypropylene resin film. In particular, when the polarizer protective film is a cellulose acetate-based resin film, the effect of suppressing the generation of bubbles is exhibited by using the pressure-sensitive adhesive sheet of the present invention.
In the present invention, since the generation of air bubbles in the adherend of the adhesive sheet can be suppressed, deterioration of visibility can be prevented when the adhesive sheet is incorporated in a display device or the like.

[Laminate]
The present invention also relates to a laminate having the above-mentioned adhesive sheet and adherend. The laminate is an adherend on at least one surface side of the adhesive layer after curing after irradiating the adhesive layer of the adhesive sheet with active energy rays and post-curing, and the adhesive layer after post-curing. To be equipped. When the pressure-sensitive adhesive sheet is a double-sided pressure-sensitive adhesive sheet, the laminate is formed by post-curing the two adherends by irradiating them with active energy rays while the two adherends are bonded together with the semi-cured pressure-sensitive adhesive sheet. Is preferable. Here, the adherend is more preferably a base material and an optical member, and particularly preferably a polycarbonate base material, a polarizing plate, a transparent film, a transparent resin or glass.

FIG. 3 is a schematic view showing a cross section of an example of the laminated body of the present invention. FIG. 3 is a cross-sectional view showing an example of the configuration of the laminated body 20 in which the pressure-sensitive adhesive sheet 21 of the present invention is bonded to the base material 22 and the optical member 24. As shown in FIG. 3, the adhesive sheet 21 of the present invention is preferably used for bonding to the base material 22, and may be used for bonding the base material 22 and another optical member 24. preferable. The pressure-sensitive adhesive sheet 21 of the present invention may be used for bonding with a polarizing plate.

Examples of the optical member included in the laminate include a shatterproof film attached to each component of an optical product such as a touch panel and an image display device, and a cover lens on the outermost layer. Examples of the constituent members of the touch panel include an ITO film in which an ITO film is provided on a transparent resin film, an ITO glass in which an ITO film is provided on the surface of a glass plate, and a transparent conductive film in which a transparent resin film is coated with a conductive polymer. Examples include hard coat films and fingerprint resistant films. Examples of the constituent members of the image display device include an antireflection film, an alignment film, a polarizing film, a retardation film, and a luminance improving film used in a liquid crystal display device.
Examples of the material used for these members include glass, polycarbonate, polyethylene terephthalate, polymethylmethacrylate, polyethylene naphthalate, cycloolefin polymer, triacetyl cellulose, polyimide, cellulose acylate and the like.

When the pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet, it can be used for bonding two adherends. In this case, the adhesive sheet of the present invention is used for bonding transparent optical films inside the touch panel, bonding the transparent optical film and glass, bonding the transparent optical film of the touch panel to the liquid crystal panel, and covering glass. It is used for bonding a transparent optical film to a cover glass and a transparent optical film, and is useful when any of the members is a polycarbonate base material. As the transparent optical film, a general film used in the optical field such as a polyethylene terephthalate film, an acrylic film, a polycarbonate film, a triacetyl cellulose film, and a cycloolefin polymer film can be used. Further, a hard coat layer may be provided on the transparent optical film or the polycarbonate base material.

FIG. 4 is a schematic view showing a cross section of another example of the laminated body of the present invention. As shown in FIG. 4, the adherend may have stepped portions (27a, 27b, 27c, 27d). In FIG. 4, the base material has a stepped portion (27a, 27b), and the optical member has a stepped portion (27c, 27d). The thickness of the stepped portion (27a, 27b, 27c, 27d) is usually 5 to 60 μm. As described above, the adhesive sheet 21 of the present invention can be attached to a member having a stepped portion, and can follow the unevenness generated from the stepped portion.

[Manufacturing method of laminate]
The method for producing a laminated body includes a step of attaching the pressure-sensitive adhesive layer of the above-mentioned pressure-sensitive adhesive sheet to an adherend in a semi-cured state and then irradiating an active energy ray to post-cure the pressure-sensitive adhesive layer. Before the irradiation with the active energy rays, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is in a semi-cured state, so that the initial adhesion to the substrate is good. In this way, after the pressure-sensitive adhesive sheet is attached to the adherend, the pressure-sensitive adhesive layer is post-cured with active energy rays, so that the cohesive force of the pressure-sensitive adhesive layer is increased and the adhesiveness to the adherend is improved. In addition, the post-cured pressure-sensitive adhesive layer can prevent the base material from being deformed or distorted.

Examples of the active energy ray include ultraviolet rays, electron beams, visible rays, X-rays, ion rays and the like, which can be appropriately selected depending on the polymerization initiator contained in the pressure-sensitive adhesive layer. Among them, from the viewpoint of versatility, ultraviolet rays or electron beams are preferable, and ultraviolet rays are particularly preferable.
As the light source of ultraviolet rays, for example, a high-pressure mercury lamp, a low-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a carbon arc, a xenon arc, an electrodeless ultraviolet lamp and the like can be used.
As the electron beam, for example, an electron beam emitted from each type of electron beam accelerator such as Cockloft Wald type, Bandecliff type, Resonant transformer type, Insulated core transformer type, Linear type, Dynamitron type, High frequency type is used. it can.
Radiation output of the UV, integrated light quantity is preferably to be a 100~10000mJ / cm ^2, and more preferably made to be 500~5000mJ / cm ^2.

When the pressure-sensitive adhesive sheet is attached to the base material and the optical member, the active energy rays can be irradiated from either the base material side or the optical member side, but it is preferable to irradiate from the base material side.

The features of the present invention will be described in more detail with reference to Examples and Comparative Examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention should not be construed as limiting by the specific examples shown below.

[Example 1]
<Synthesis of crosslinkable acrylic polymer>
A crosslinkable acrylic polymer was prepared by solution polymerization in ethyl acetate. 2-methoxyethyl acrylate monomer (MEA), 2-hydroxyethyl acrylate monomer (2HEA), methyl methacrylate (MMA), dimethylacrylamide (DMAA) and butyl acrylate (BA) in a mass ratio of 70:10: 10: 5: 5. AIBN (azobisisobutyronitrile) was dissolved in the solution as a radical polymerization initiator. The solution was heated to 60 ° C. and randomly copolymerized to obtain a crosslinkable acrylic polymer A. The solution viscosity of the 35% by mass solution of the crosslinkable acrylic polymer A at 23 ° C. was 2000 mPa · s.

0.2 parts by mass of xylylene diisocyanate compound (Takenate D-110N, manufactured by Mitsui Chemicals, Inc.) as a cross-linking agent and bisphenol A ethylene oxide as a polyfunctional monomer with respect to 100 parts by mass of the crosslinkable acrylic polymer A. 8 parts by mass of modified diacrylate (Aronix M211B, manufactured by Toa Synthetic Co., Ltd.), 8 parts by mass of isobornyl acrylate (IBXA, Tg = 97 ° C.) as a monofunctional monomer, 0.3 parts by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF Japan Co., Ltd., IRGACURE184) was added as a polymerization initiator, and ethyl acetate was added as a solvent so that the solid content concentration became 40% by mass. The pressure-sensitive adhesive composition was obtained.

The pressure-sensitive adhesive composition was applied onto a first release sheet (heavy separator film, Teijin DuPont Film Co., Ltd., release-treated polyethylene terephthalate film). The coating was carried out using a doctor blade YD type manufactured by Yoshimitsu Seiki Co., Ltd. so that the thickness after drying was 25 μm. Then, it was dried in a hot air dryer at 100 ° C. for 3 minutes to remove the solvent, and a pressure-sensitive adhesive sheet having a semi-cured pressure-sensitive adhesive layer was formed.
A second release sheet (light separator film, manufactured by Teijin DuPont Film Co., Ltd.), which has been subjected to a mold release treatment that is more peelable than the first release sheet, is attached to one side of this adhesive sheet, and the adhesive with the release sheet is attached. An adhesive sheet of Example 1 which is a sheet was obtained.

[Example 2]
In <Synthesis of Crosslinkable Acrylate Polymer> of Example 1, 2-methoxyethyl acrylate monomer (MEA), 2-hydroxyethyl acrylate monomer (2HEA), methyl methacrylate (MMA), dimethyl acrylamide (DMAA) and butyl acrylate ( The mass ratio of BA) was changed from 70:10: 10: 5: 5 to 80: 7: 7: 5: 1 to obtain a crosslinkable acrylic polymer C. The solution viscosity of the 35% by mass solution of the crosslinkable acrylic polymer C at 23 ° C. was 2100 mPa · s. A pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet with a release sheet were obtained in the same manner as in Example 1 except that the amount of the cross-linking agent added to 100 parts by mass of the crosslinkable acrylic polymer C was 1.0 part by mass.

[Example 3]
Adhesive composition and release sheet in the same manner as in Example 1 except that IBXA, which is a monofunctional monomer, was changed to N-acryloyloxyethyl hexahydrophthalimide (Aronix M-140, manufactured by Toagosei Co., Ltd.). I got an adhesive sheet with.

[Example 4]
M211B, which is a polyfunctional monomer, is changed to trimethylolpropane propylene oxide-modified triacrylate (manufactured by Toagosei Co., Ltd., M310, Tg120 ° C.) in the same manner as in Example 1 with an adhesive composition and a release sheet. Obtained an adhesive sheet.

[Example 5]
A pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet with a release sheet were prepared in the same manner as in Example 1 except that M211B, which is a polyfunctional monomer, was changed to polyethylene glycol diacrylate (M220, Tg 90 ° C., manufactured by Toagosei Co., Ltd.). Obtained.

[Comparative Example 1]
A crosslinkable acrylic polymer was prepared by solution polymerization in ethyl acetate. 2-Hydroxyethyl acrylate monomer (2HEA), dimethylacrylamide (DMAA) and butyl acrylate (BA) are blended in a mass ratio of 5:20:75, and AIBN (azobisisobutyronitrile) is used as a radical polymerization initiator. ) Was dissolved in the solution. The solution was heated to 60 ° C. and randomly copolymerized to obtain a crosslinkable acrylic polymer E. The solution viscosity of the 35% by mass solution of the crosslinkable acrylic polymer E at 23 ° C. was 3500 mPa · s.

0.2 parts by mass of xylylene diisocyanate compound (manufactured by Mitsui Chemicals Co., Ltd., Takenate D-110N) as a cross-linking agent and bisphenol A ethylene oxide as a polyfunctional monomer with respect to 100 parts by mass of the crosslinkable acrylic polymer E 8 parts by mass of modified diacrylate (Aronix M211B, manufactured by Toa Synthetic Co., Ltd.), 8 parts by mass of isobornyl acrylate (IBXA, Tg = 97 ° C.) as a monofunctional monomer, 0.3 parts by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF Japan Co., Ltd., IRGACURE184) was added as a polymerization initiator, and ethyl acetate was added as a solvent so that the solid content concentration became 40% by mass. The pressure-sensitive adhesive composition was obtained.
Using this pressure-sensitive adhesive composition, a pressure-sensitive adhesive sheet with a release sheet was obtained in the same manner as in Example 1.

[Comparative Example 2]
An adhesive sheet with a release sheet was obtained in the same manner as in Example 4 except that the crosslinkable acrylic polymer A was changed to the crosslinkable acrylic polymer E.

[Measurement and evaluation]
<Constant load peeling distance>
The light release separator, which is the second release sheet, was peeled off, and instead of the peeled separator, a triacetyl cellulose film (manufactured by FUJIFILM Corporation, Fujitac TD60UL, thickness 60 μm) was laminated using a hand roller to prepare a laminated film. .. This laminated film was cut into a size of 25 mm in width and 100 mm in length, and the first release sheet was peeled off. Next, of the exposed 25 mm wide and 100 mm long adhesive surfaces, the region of 25 mm wide and 75 mm long is the hard coated surface side of the adherend (polycarbonate plate with hard coat layer: manufactured by Mitsubishi Gas Chemical Company, Iupilon MR58, 1 mm thick). It was attached to the surface using a 2 kg crimping roller. In this state, the film was kept in an autoclave under the conditions of 40 ° C. and 5 atm for 30 minutes to be brought into close contact with the PC plate, and then irradiated with ultraviolet rays from the triacetyl cellulose film side so that the integrated light intensity was 3000 mJ / cm ² . A test piece was prepared by leaving it to stand for 24 hours in an environment of 23 ° C. and a relative humidity of 50%. Two of the above test pieces were prepared.
For this set of test pieces, as shown in FIG. 2, in an environment of 23 ° C., in the length direction of the non-bonded region (width 25 mm, length 25 mm) of the laminated film composed of the adhesive sheet 1 and the triacetyl cellulose film 30. A 300 g weight 34 was hung at the end, a load of 300 g was applied in the direction of 90 ° to the plane of the adherend 32, and the film was left in that state for 30 minutes. During that time, the length L (constant load peeling distance) of the portion where the laminated film was peeled off was measured. The other set of test pieces was left in an environment of 85 ° C. for 30 minutes, and then in an environment of 85 ° C. in the length direction of the non-bonded region (width 25 mm, length 25 mm) of the laminated film as shown in FIG. A 100 g weight 34 was hung at the end, a load of 100 g was applied in the direction of 90 ° to the plane of the adherend 32, and the mixture was left in that state for another 10 minutes. During that time, the length L (constant load peeling distance) of the portion where the laminated film was peeled off was measured.

<Probe tack value>
The second release sheet, which is a light separator film of the adhesive sheet, was peeled off and attached to a PET film to prepare a measurement sample in a semi-cured state.
The second release sheet, which is a light separator film of another adhesive sheet, was peeled off and attached to the PET film. Next, ultraviolet rays were irradiated from the side of the first release sheet, which is a heavy separator film, so that the integrated light intensity was 3000 mJ / cm ^2, and a sample for measurement after post-curing was prepared.
Each measurement sample was cut into 3 cm × 3 cm and measured with a probe tack tester under the following conditions. The measurement temperature was 23 ° C.
Measuring equipment: NS probe tack tester (manufactured by Nichiban Co., Ltd.)
Probe diameter: 5 mmφ
Probe base material: Stainless steel surface finish AA # 400 Mirror surface weight by polishing: 19.6 g (made of brass)
Probe moving speed: 1.0 cm / sec Duel time: 1 sec

<Gel fraction>
The pressure-sensitive adhesive layer was cut to a size of 100 mm × 60 mm to prepare a semi-cured measurement sample.
The pressure-sensitive adhesive layer is cut to a size of 100 mm × 60 mm, and ultraviolet rays are irradiated from the side of the first release sheet, which is a heavy separator film, so that the integrated light intensity is 3000 mJ / cm ^2, and the sample for measurement after post-curing is prepared. Made.
About 0.1 g of an adhesive sheet for each measurement sample was collected in a sample bottle, 30 ml of ethyl acetate was added, and the mixture was shaken for 24 hours. Then, the contents of this sample bottle were filtered off with a 150 mesh stainless steel wire mesh, and the residue on the wire mesh was dried at 100 ° C. for 1 hour to measure the dry mass (g). From the obtained dry mass, the gel fraction was calculated by the following formula 1.
Gel fraction (mass%) = (dry mass / collected mass of adhesive sheet) x 100 ... Equation 1

<Sticky end face>
Fifty A4 size adhesive sheets irradiated with ultraviolet rays from the side of the first release sheet, which is a heavy separator film, so that the integrated light intensity was 3000 mJ / cm ² , were superposed to prepare a sample for cutting after post-curing.
The guillotine blade when the adhesive sheet used as a sample for cutting after post-curing was cut by a guillotine cutting machine, and the end surface which is the cutting surface of the adhesive sheet were visually judged.
The adhesive does not squeeze out from the end face, which is the cutting surface of the adhesive sheet, and the guillotine blade and the end face, which is the cutting surface, are not sticky and are good ... ○
The adhesive squeezes out severely from the end face, which is the cutting surface of the adhesive sheet, and the guillotine blade and the end face stickiness, which is the cutting surface, are at a level that poses a practical problem ...

<Workability>
First, the second release sheet, which is a light separator film of the pressure-sensitive adhesive layer, was peeled off and bonded to a PET film having a thickness of 25 μm.
Next, the first release sheet, which is a heavy separator film, was peeled off and attached to a PC plate. The sample having the composition of PET / adhesive layer / PC was autoclaved (40 ° C., 0.5 MPa, 30 min), and then ultraviolet rays were irradiated from the PET film side so that the integrated light intensity was 3000 mJ / cm ^2, and the test sample was obtained. Got Next, the end portion of the test sample was cut using a guillotine cutting machine, and the cut end portion was rubbed by hand so as to peel off the PET film from the PC plate side. The peeling distance at that time was measured.
Peeling distance is less than 0.05 mm ... ◎
Peeling distance is 0.05 mm or more and less than 0.1 mm ... 〇 Peeling distance is 0.1 mm or more ... ×

<High temperature durability>
The light release separator, which is the second release sheet, was peeled off, and instead of the peeled separator, a triacetyl cellulose film (manufactured by FUJIFILM Corporation, Fujitac TD60UL, thickness 60 μm) was laminated using a hand roller to prepare a laminated film. .. The laminated film was cut into a size of 60 mm in width and 80 mm in length, and the first release sheet was peeled off. Next, the exposed adhesive surface having a width of 60 mm and a length of 80 mm is attached to the hard coat surface side of the adherend (polycarbonate plate with hard coat layer: manufactured by Mitsubishi Gas Chemical Company, Iupilon MR58, thickness 1 mm) using a 2 kg crimping roller. It was. In this state, the film was kept in an autoclave under the conditions of 40 ° C. and 5 atm for 30 minutes to be brought into close contact with the polycarbonate plate, and then ultraviolet rays were irradiated from the triacetyl cellulose film side so that the integrated light amount was 3000 mJ / cm ² . A test piece was prepared by leaving it to stand for 24 hours in an environment of 23 ° C. and a relative humidity of 50%. Next, the test sample was placed in a dry environment at 105 ° C., and the presence or absence of floating and peeling after 240 hours was observed.
No floating or peeling is observed ... ○
Lifting and / or peeling of 1.0 mm or more is observed ... ×

From Table 1 above, it was found that the adhesive sheet of the example was excellent in high temperature durability. In addition, the adhesive sheet of the example had no stickiness on the end face and had good workability.

On the other hand, the adhesive sheet of the comparative example was inferior in high temperature durability and processability.

1 Adhesive sheet 11 Adhesive layer 12a Transparent base material or release sheet 12b Release sheet 20 Laminated body 21 Adhesive sheet 22 Base material 24 Optical members 27a, 27b, 27c, 27d Steps 30 Triacetyl cellulose film 32 Adhesive body 34 Weight L Constant load peeling distance

Claims (12)

A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer in which the pressure-sensitive adhesive composition is in a semi-cured state.
The pressure-sensitive adhesive composition is a cross-linking acrylic polymer, a cross-linking agent, a polyfunctional monomer having two or more reactive double bonds in the molecule, and a monofunctional monomer having one reactive double bond in the molecule. Contains body and polymerization initiator,
The crosslinkable acrylic polymer is derived from a unit derived from an alkoxyalkyl group-containing (meth) acrylate, a unit derived from a hydroxy group-containing (meth) acrylate, a unit derived from methyl (meth) acrylate, and a nitrogen-containing monomer. Contains units to
The content of the unit derived from an alkoxyalkyl group-containing (meth) acrylate to the total weight of the crosslinkable acrylic polymer is Ri 50-90% by mass,
The content of the unit derived from the nitrogen-containing monomer is 1 to 20% by mass with respect to the total mass of the crosslinkable acrylic polymer.
The polyfunctional monomer is a monomer having a bisphenol skeleton in one molecule, or is homozygous when it has an alkylene glycol group in one molecule and the polyfunctional monomer is polymerized. A monomer having a polymer glass transition temperature (Tg) of 150 or less.
The monofunctional monomer includes isobornyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, benzyl methacrylate, N-acryloyloxyethyl hexahydrophthalimide, acrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, An adhesive sheet which is at least one selected from the group consisting of acryloylmorpholin and vinylpyrrolidone . The pressure-sensitive adhesive sheet according to claim 1 , wherein the content of the carboxy group-containing monomer unit with respect to the total mass of the crosslinkable acrylic polymer is 0.1% by mass or less. The pressure-sensitive adhesive sheet according to claim 1 or 2 , wherein when the pressure-sensitive adhesive layer is post-cured, the gel fraction after post-curing is 65 to 100% by mass. The gel fraction of the pressure-sensitive adhesive layer in the semi-cured state is 10% by mass or more and less than 70% by mass, and
The pressure-sensitive adhesive sheet according to any one of claims 1 to 3 , wherein when the pressure-sensitive adhesive layer is post-cured, the gel fraction after post-curing becomes 10% by mass or more higher than the gel fraction in the semi-cured state. .. The pressure-sensitive adhesive sheet according to any one of claims 1 to 4 , wherein the cross-linking agent is a bifunctional or higher functional isocyanate compound. The invention according to any one of claims 1 to 5 , wherein the total content of the monofunctional monomer and the polyfunctional monomer is 6 to 50 parts by mass with respect to 100 parts by mass of the crosslinkable acrylic polymer. Adhesive sheet. The pressure-sensitive adhesive sheet according to any one of claims 1 to 6 , wherein the content of the polyfunctional monomer is 5 to 30 parts by mass with respect to 100 parts by mass of the crosslinkable acrylic polymer. The pressure-sensitive adhesive sheet according to any one of claims 1 to 7 , wherein the polymerization initiator initiates the polymerization of the polyfunctional monomer and / or the monofunctional monomer by irradiation with active energy rays. An adhesive sheet with a release sheet, comprising a pair of release sheets having different release forces on both surfaces of the adhesive sheet according to any one of claims 1 to 8 . At least one transparent film selected from a polyethylene terephthalate film, an acrylic film, a polycarbonate film, a triacetyl cellulose film, and a cycloolefin polymer film on at least one surface of the pressure-sensitive adhesive sheet according to any one of claims 1 to 8. Adhesive sheet with transparent film. At least one of the post-curing pressure-sensitive adhesive layer after irradiating the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to any one of claims 1 to 8 with active energy rays and post-curing, and the post-curing pressure-sensitive adhesive layer. A laminated body having an adherend on one surface side. After the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to any one of claims 1 to 8 is attached to an adherend in a semi-cured state, the pressure-sensitive adhesive layer is post-cured by irradiating with active energy rays. A method for manufacturing a laminate including a process.

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