WO2018101335A1

WO2018101335A1 - Double-sided adhesive sheet, and method for producing double-sided adhesive sheet

Info

Publication number: WO2018101335A1
Application number: PCT/JP2017/042828
Authority: WO
Inventors: 晃司土渕; 高志阿久津; 揮一郎加藤
Original assignee: リンテック株式会社
Priority date: 2016-11-30
Filing date: 2017-11-29
Publication date: 2018-06-07

Abstract

Provided is a double-sided adhesive sheet comprising a laminate produced by directly laminating a first adhesive agent layer (X1), a base layer (Y) and a second adhesive agent layer (X2) in this order, wherein the laminate is formed by directly laminating a coating film (x1') made from a composition (x1) that is a material for forming the first adhesive agent layer and contains an adhesive resin, a coating film (y') made from a composition (y) that is a material for forming the base layer (Y) and contains a non-adhesive resin selected from the group consisting of an acrylic urethane resin and an olefin resin, and a coating film (x2') made from a composition (x2) that is a material for forming the second adhesive agent layer and contains an adhesive resin in this order, and then drying the coating films (x1'), (y') and (x2') simultaneously. The double-sided adhesive sheet is highly prevented from the occurrence of an undesired separation phenomenon, i.e., a phenomenon that the adhesive agent layers are divided and torn from each other in conjunction with two release sheets upon the peeling off of one of the release sheets, and the double-sided adhesive sheet also has excellent punching properties, and is excellent in adhesion fitness and cutting processability.

Description

Double-sided pressure-sensitive adhesive sheet and method for producing double-sided pressure-sensitive adhesive sheet

The present invention relates to a double-sided pressure-sensitive adhesive sheet and a method for producing a double-sided pressure-sensitive adhesive sheet.

The double-sided pressure-sensitive adhesive sheet is used for fixing various members such as building materials, electronic parts, and interior materials.
As such a double-sided pressure-sensitive adhesive sheet, a baseless double-sided pressure-sensitive adhesive sheet having a configuration in which a single pressure-sensitive adhesive layer is sandwiched between two release sheets without providing a base material (core material), or a base material (core material) ) Is provided with a pressure-sensitive adhesive layer on both surfaces, and a pressure-sensitive adhesive sheet with a substrate having a structure in which a release sheet is laminated on each pressure-sensitive adhesive layer is known.

In Patent Document 1, as a double-sided pressure-sensitive adhesive sheet without a base material, a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive are respectively formed on the surface and the back surface of a base material pressure-sensitive adhesive formed only with a specific resin used as a pressure-sensitive adhesive. A double-sided pressure-sensitive adhesive sheet comprising only a pressure-sensitive adhesive provided with an agent layer is disclosed.

Moreover, in patent document 2, it has a transparent 1st adhesion layer and a 2nd adhesion layer respectively on two surfaces of an optically non-oriented and transparent base material as an adhesive sheet with a base material. A double-sided pressure-sensitive adhesive film in which the thickness of three laminated layers is 55 μm or less and the internal HAZE is 1 or less is disclosed.

Japanese Patent No. 4025405 JP 2007-119562 A

By the way, the double-sided pressure-sensitive adhesive sheet without a substrate as described in Patent Document 1 is likely to stick out of the adhesive layer from the end during sticking to the adherend or during storage, and may contaminate the adherend or the like. is there.
Further, the double-sided pressure-sensitive adhesive sheet without a substrate tends to cause a so-called “crying phenomenon”, which is a phenomenon in which the pressure-sensitive adhesive layer is divided and peeled off along with two release sheets when one release sheet is peeled off.
Furthermore, when punching a double-sided pressure-sensitive adhesive sheet without a substrate, problems such as shape deformation and oozing out of the pressure-sensitive adhesive layer are likely to occur, and there is a problem in punchability.

On the other hand, the double-sided pressure-sensitive adhesive sheet with a substrate is more effective than the pressure-sensitive adhesive sheet without a substrate in suppressing the sticking-out of the adhesive layer from the edge during sticking to the adherend or storage and the effect of suppressing the tearing phenomenon. Although it can be improved, it has a problem that the punching process is inferior.
Moreover, the double-sided pressure-sensitive adhesive sheet with a base material described in Patent Document 2 is caused by low interfacial adhesion between the base material and the pressure-sensitive adhesive layer, and is uniformly stretched according to the shape of the adherend. It tends to be difficult to apply. Also, the decrease in interfacial adhesion between the substrate and the pressure-sensitive adhesive layer is caused by the linear lifting parallel to the width direction in the cutting process where the roll product is unwound and the end is cut off and rolled up again. This causes the so-called “tunneling”.

In the present invention, when one release sheet is peeled off, the pressure-sensitive adhesive layer is divided and peeled off along with the two release sheets, and the effect of suppressing the tearing phenomenon is high. It aims at providing the manufacturing method of the double-sided adhesive sheet which is excellent, and a double-sided adhesive sheet.

For the double-sided pressure-sensitive adhesive sheet having a laminate in which the first pressure-sensitive adhesive layer, the base material layer, and the second pressure-sensitive adhesive layer are directly laminated in this order, the laminate is made of the above three-layer forming material. It has been found that the above-mentioned problems can be solved by sequentially laminating a coating film made of a certain composition and drying it at the same time.

That is, the present invention relates to the following [1] to [14].
[1] A double-sided pressure-sensitive adhesive sheet having a laminate in which a first pressure-sensitive adhesive layer (X1), a base material layer (Y), and a second pressure-sensitive adhesive layer (X2) are directly laminated in this order,
The laminate is
A coating film (x1 ′) comprising a composition (x1) containing an adhesive resin, which is a material for forming the first adhesive layer;
A coating film (y ′) made of a composition (y) containing a non-adhesive resin selected from the group consisting of an acrylic urethane-based resin and an olefin-based resin, which is a forming material of the base material layer (Y);
A coating film (x2 ′) comprising a composition (x2) containing an adhesive resin, which is a material for forming the second adhesive layer;
Are laminated | stacked directly in this order, Then, the double-sided adhesive sheet formed by drying simultaneously a coating film (x1 '), (y'), and (x2 ').
[2] In the above [1], the thickness ratio of the base material layer (Y) to the total thickness 100 of the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2) is 1 to 100 The double-sided pressure-sensitive adhesive sheet described.
[3] The double-sided pressure-sensitive adhesive sheet according to the above [1] or [2], wherein the thickness of the laminate is 2 to 90 μm.
[4] The double-sided pressure-sensitive adhesive sheet according to any one of [1] to [3], wherein the thickness of the base material layer (Y) is 0.3 to 50.0 μm.
[5] The double-sided pressure-sensitive adhesive sheet according to any one of the above [1] to [4], wherein the adhesive resin contained in the compositions (x1) and (x2) comprises an acrylic resin.
[6] Both sides according to any one of [1] to [5], wherein the non-adhesive resin contained in the composition (y) is an ultraviolet non-curable resin having no polymerizable functional group. Adhesive sheet.
[7] The double-sided pressure-sensitive adhesive sheet according to any one of [1] to [6], wherein the base material layer (Y) is an unstretched sheet-like material.
[8] The double-sided pressure-sensitive adhesive sheet according to any one of [1] to [7], wherein the base layer (Y) has a breaking elongation of 100% or more.
[9] The double-sided pressure-sensitive adhesive sheet according to any one of [1] to [8], wherein the base material layer (Y) has a breaking strength of 30 MPa or more.
[10] The double-sided pressure-sensitive adhesive sheet according to any one of [1] to [9], wherein the laminate has a haze of 5.00% or less.
[11] The double-sided pressure-sensitive adhesive sheet according to any one of [1] to [10], wherein the laminate has a total light transmittance of 80% or more.
[12] A method for producing the double-sided pressure-sensitive adhesive sheet according to any one of [1] to [11] above,
A method for producing a double-sided pressure-sensitive adhesive sheet, comprising the following steps (1) to (2).
Step (1): a coating film (x1 ′) composed of the composition (x1), a coating film (y ′) composed of the composition (y), and a coating film (x2 ′) composed of the composition (x2) A process of directly stacking layers in this order.
-Process (2): The process of drying a coating film (x1 '), a coating film (y'), and a coating film (x2 ') simultaneously, and forming the said laminated body.
[13] The method for producing a double-sided pressure-sensitive adhesive sheet according to [12], wherein in the step (1), the composition (x1), the composition (y), and the composition (x2) are applied simultaneously.
[14] The method for producing a double-sided pressure-sensitive adhesive sheet according to the above [12] or [13], wherein the composition (x1), the composition (y), and the composition (x2) further contain a diluent solvent.

The double-sided pressure-sensitive adhesive sheet of the present invention has a high effect of suppressing the tearing phenomenon that the pressure-sensitive adhesive layer is divided and peeled off with the two release sheets when peeling one of the release sheets. Due to high interfacial adhesion to the agent layer, it is excellent in punching processability, pasting ability and cutting processability.
Moreover, since the manufacturing method of the double-sided adhesive sheet of this invention can reduce the number of processes and improve handling property, the double-sided adhesive sheet which has such a characteristic can improve and can manufacture.

It is a cross-sectional schematic diagram of a double-sided pressure-sensitive adhesive sheet showing an example of the configuration of the double-sided pressure-sensitive adhesive sheet of the present invention.

In the present invention, whether the target resin belongs to “adhesive resin” or “non-adhesive resin” is determined based on the following procedures (1) to (4).
Procedure (1): A 20 μm thick resin layer formed from only the target resin is laminated on the surface of a 50 μm thick polyethylene terephthalate (PET) film to a size of 300 mm length × 25 mm width A cut specimen is prepared.
・ Procedure (2): Under an environment of 23 ° C. and 50% RH (relative humidity), the surface of the resin layer exposed on the test piece is attached to a stainless steel plate (SUS304 No. 360 polishing). Leave for 24 hours.
・ Procedure (3): After standing, in an environment of 23 ° C. and 50% RH (relative humidity), the adhesive strength was increased at a pulling speed of 300 mm / min by 180 ° peeling method based on JIS Z0237: 2000. taking measurement.
Procedure (4): If the measured adhesive strength is 0.1 N / 25 mm or more, the target resin is determined as an “adhesive resin”. On the other hand, if the measured adhesive strength is less than 0.1 N / 25 mm, the target resin is determined as a “non-adhesive resin”.

In the present specification, the “active ingredient” refers to a component excluding a diluent solvent among components contained in a target composition.
Moreover, a mass average molecular weight (Mw) and a number average molecular weight (Mn) are the values of standard polystyrene conversion measured by a gel permeation chromatography (GPC) method, and are specifically based on the method as described in an Example. Measured value.

In the present specification, for example, “(meth) acrylic acid” indicates both “acrylic acid” and “methacrylic acid”, and the same applies to other similar terms.
Moreover, about the preferable numerical range (for example, range of content etc.), the lower limit value and upper limit value which were described in steps can be combined independently, respectively. For example, from the description “preferably 10 to 90, more preferably 30 to 60”, “preferable lower limit (10)” and “more preferable upper limit (60)” are combined to obtain “10 to 60”. You can also.

[Configuration of the double-sided pressure-sensitive adhesive sheet of the present invention]
If the double-sided pressure-sensitive adhesive sheet of the present invention has a laminate in which the first pressure-sensitive adhesive layer (X1), the base material layer (Y), and the second pressure-sensitive adhesive layer (X2) are directly laminated in this order, It is not limited.
FIG. 1 is a schematic cross-sectional view of a double-sided PSA sheet showing the configuration of the double-sided PSA sheet of the present invention.

The double-sided pressure-sensitive adhesive sheet of the present invention has a first pressure-sensitive adhesive layer (X1) 121, a base material layer (Y) 11, and a second pressure-sensitive adhesive layer (X2) like the double-sided pressure-sensitive adhesive sheet 1 shown in FIG. What is necessary is just to have the laminated body 10 which laminated | stacked 122 directly in this order.
Here, the above-mentioned “directly laminated” means between the first pressure-sensitive adhesive layer (X1) and the base material layer (Y), and between the base material layer (Y) and the second pressure-sensitive adhesive layer (X2). Between the two, it refers to a configuration in which the two layers are in direct contact with no other layers.
The “laminate” of the double-sided pressure-sensitive adhesive sheet of the present invention is composed of the first pressure-sensitive adhesive layer (X1), the base material layer (Y), and the second pressure-sensitive adhesive layer (X2). Other layers (such as a release material, a third pressure-sensitive adhesive layer, and a fourth pressure-sensitive adhesive layer described later) are not included in the configuration of the laminate.

As a double-sided pressure-sensitive adhesive sheet of one embodiment of the present invention, from the viewpoint of handleability, one or both surfaces of the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2) (in contact with the base material layer) It is preferable that a release material is further provided on the surface (on the opposite side of the surface).
That is, as the double-sided pressure-sensitive adhesive sheet of this aspect, the double-sided pressure-sensitive adhesive sheet 2 further having a release material 131 on the sticking surface of the first pressure-sensitive adhesive layer (X1) 121 shown in FIG. The double-sided pressure-sensitive adhesive sheet 3 further having

release materials

131 and 132 on the sticking surfaces of the first pressure-sensitive adhesive layer (X1) 121 and the second pressure-sensitive adhesive layer (X2) 122 shown in FIG.

In addition, in the double-sided adhesive sheet 2 shown in FIG.1 (b), it is good also as a double-sided adhesive sheet which has the structure wound in roll shape using the peeling material by which the peeling process was given to both surfaces as the peeling material 131. FIG.
Moreover, in the double-sided adhesive sheet 3 shown in FIG.1 (c), from the viewpoint of improving the suppression effect of a tearing-off phenomenon, as the

release materials

131 and 132, two types of release materials designed to have different release forces from each other. Is preferably used.

Moreover, as a double-sided adhesive sheet of 1 aspect of this invention, it is the 1st adhesive layer (X1) and one or both sticking surfaces (the side which is contacting the base material layer) of a 2nd adhesive layer (X2). It is good also as a structure which laminated | stacked the adhesive layer formed from the composition which is a different formation material on the surface of the other side.
As such an embodiment, for example, a third pressure-sensitive adhesive layer (X3) 123 is further provided on the sticking surface of the first pressure-sensitive adhesive layer (X1) 121 as shown in FIG. The double-sided pressure-sensitive adhesive sheet 4 in which a fourth pressure-sensitive adhesive layer (X4) 124 is further provided on the adhesive surface of the pressure-sensitive adhesive layer (X2) 122 is mentioned.

In the double-sided pressure-sensitive adhesive sheet 4, the first pressure-sensitive adhesive layer (X1) and the third pressure-sensitive adhesive layer (X3) may be formed from compositions that are the same forming material and are different from each other. It may be formed from a composition that is Similarly, the second pressure-sensitive adhesive layer (X2) and the fourth pressure-sensitive adhesive layer (X4) may also be formed from compositions that are the same forming material, and compositions that are different from each other. It is formed from things.
However, when 1st adhesive layer (X1) and 3rd adhesive layer (X3) are formed from the composition which is the same formation material, 1st adhesive layer (X1) and 3rd adhesive The layer (X3) is not formed by simultaneously applying and drying the respective compositions, but is formed separately. The same applies to the second pressure-sensitive adhesive layer (X2) and the fourth pressure-sensitive adhesive layer (X4).

[Laminate]
The laminated body which the double-sided pressure-sensitive adhesive sheet of the present invention has includes a coating film (x1 ′) made of a composition (x1) containing an adhesive resin, which is a material for forming the first pressure-sensitive adhesive layer, and a base material layer (Y). A coating material (y ′) made of a composition (y) containing a non-adhesive resin selected from the group consisting of acrylic urethane resins and olefin resins, and a forming material for the second adhesive layer And after directly laminating the coating film (x2 ′) made of the composition (x2) containing the adhesive resin in this order, the coating films (x1 ′), (y ′) and (x2 ′) are simultaneously formed. It is formed by drying.

The double-sided pressure-sensitive adhesive sheet with a substrate is generally produced by the following method (hereinafter also referred to as “conventional production method”).
・ Manufacturing which has a process of applying a pressure-sensitive adhesive composition to both surfaces of a base material already formed into a film or sheet to form a coating film and drying the coating film to form a pressure-sensitive adhesive layer. Method.
・ On the release-treated surface of the release film, the adhesive composition is applied to form a coating film, and two films are prepared by drying the coating film to form an adhesive layer. The manufacturing method which has the process of affixing the adhesive layer formed on the peeling film, respectively on both surfaces of the base material already shape | molded in (1).
In each of the conventional production methods described above, a base material that has already been formed into a film shape or a sheet shape is used, and the pressure-sensitive adhesive layer is on the surface of the base material or the release treatment surface of the release film. Forming. That is, in the conventional manufacturing method, the base material and the pressure-sensitive adhesive layer are generally formed separately.

However, the pressure-sensitive adhesive sheet with a base material obtained by the above-described conventional manufacturing method is such that the base material and the pressure-sensitive adhesive layer are formed separately, so that the interface adhesion between the base material and the pressure-sensitive adhesive layer is Power is low.
In addition, the pressure-sensitive adhesive sheet with the base material is caused by the difference in mechanical properties between the base material and the pressure-sensitive adhesive layer, and the problem that the punching processability is inferior, and the base sheet and the pressure-sensitive adhesive layer are uniformly extended according to the shape of the adherend. There is a problem that sticking tends to be difficult. Furthermore, there is also a problem that so-called “tunneling” occurs in the cutting process of cutting off the end portion while winding the roll product and winding it up again in the form of a roll. .

On the other hand, the laminated body which the double-sided adhesive sheet of this invention has is the coating film (x1 ') which consists of each composition which is a formation material of a 1st adhesive layer, a base material layer, and a 2nd adhesive layer, (y ') And (x2') are formed by directly laminating these three coatings “simultaneously” after being directly laminated in this order.
Since the laminate was formed as such, it was between the first pressure-sensitive adhesive layer (X1) and the base material layer (Y), and between the base material layer (Y) and the second pressure-sensitive adhesive layer (X2). The interfacial adhesion is much higher than that of the pressure-sensitive adhesive sheet with a substrate obtained by the above-described general production method.
This is the process of simultaneously drying the above three coating films, the interface between the coating film (x1 ′) and the coating film (y ′), and the interface between the coating film (x1 ′) and the coating film (y ′). Thus, it is presumed that the molecular chain of the adhesive resin and the molecular chain of the non-adhesive resin included in each composition are easily entangled while the mixed layer is generated. Thereby, it is thought that the interface adhesiveness of a base material layer and an adhesive layer improves markedly.
As a result, the double-sided pressure-sensitive adhesive sheet of the present invention has a tearing phenomenon in which the pressure-sensitive adhesive layer is divided and peeled off along with the two peeling sheets when peeling one release sheet (hereinafter also simply referred to as “crying phenomenon”). ) Is highly effective and can be excellent in punching workability, sticking suitability and cutting workability.

In addition, in this invention, although the laminated body which a double-sided adhesive sheet has is specified by the manufacturing method as mentioned above, the situation which must be specified by such a manufacturing method exists.
As a method for prescribing the configuration of the laminate without specifying the manufacturing method, for example, the cross section cut in the thickness direction of the laminate using an electron microscope or the like, the interface between the base material layer and the adhesive layer In some cases, the interface can be specified by some physical property value.
Here, as a method for evaluating the interface between the base material layer and the pressure-sensitive adhesive layer, for example, a method of measuring the surface roughness can be considered. However, since the roughness of the interface is very small, it cannot be measured accurately, and the difference in the roughness state depending on the region to be observed is very large. For this reason, it is extremely difficult to evaluate by physical property values such as surface roughness.
In addition, depending on the type of adhesive resin contained in the adhesive layer and non-adhesive resin contained in the substrate layer, an electron microscope or the like may be used to observe the interface between the substrate layer and the adhesive layer. In some cases, the interface becomes unclear, and the surface roughness measurement itself may be difficult.
Furthermore, when the laminate is cut in the thickness direction in order to obtain a cross section of the laminate, the laminate is formed from a resin, so that the shape of the interface between the base material layer and the adhesive layer is There is also a situation that the interface state cannot be accurately evaluated.
Under such circumstances, in the present invention, the laminate of the double-sided pressure-sensitive adhesive sheet must be specified by the production method as described above.

In the present specification, the “coating film” is a film formed from a composition that is a forming material by a known coating method, and the residual ratio of volatile components such as a solvent contained in the film. It refers to those in a state of 10 to 100% by mass with respect to 100% by mass of the total amount of volatile components contained in the composition before coating.
That is, in the present specification, the coating films (x1 ′), (y ′), and (x2 ′) contain a certain amount of a volatile component such as a solvent. And the volatile component was removed by drying the coating film of these 3 layers simultaneously, and it comprised from the 1st adhesive layer (X1), the base material layer (Y), and the 2nd adhesive layer (X2). A laminate is formed.

In addition, about the method of forming a coating film (x1 '), (y'), and (x2 '), and the drying conditions of the formed coating film, description of the item of "the manufacturing method of a double-sided adhesive sheet" mentioned later is mentioned. It is as follows.

In addition, since a base material layer (Y) is formed as mentioned above, it becomes an unstretched sheet-like material.
In the present specification, the “non-stretched sheet-like material” excludes a sheet-like material obtained by intentionally stretching in a specific direction. For example, in a continuous manufacturing process such as using a roll to roll manufacturing apparatus, when the film is stretched by a force forcefully applied in the flow direction, it is not limited to this and may be regarded as a “non-stretched sheet”. it can.

<Composition (x1), (x2)>
Both the composition (x1) which is a forming material of the first pressure-sensitive adhesive layer (X1) and the composition (x2) which is a forming material of the second pressure-sensitive adhesive layer (X2) contain a pressure-sensitive adhesive resin. .
In one embodiment of the present invention, the compositions (x1) and (x2) may be the same or different from each other. The components contained in the compositions (x1) and (x2) can be appropriately adjusted according to the use application of the double-sided pressure-sensitive adhesive sheet of the present invention.

In one embodiment of the present invention, from the viewpoint of making a double-sided PSA sheet with improved adhesive strength, the compositions (x1) and (x2) may further contain a tackifier and a crosslinking agent. Moreover, you may contain the additive for adhesives used for a general adhesive.
The compositions (x1) and (x2) are also used as materials for forming the third pressure-sensitive adhesive layer (x3) and the fourth pressure-sensitive adhesive layer (x4) included in the double-sided pressure-sensitive adhesive sheet 4 shown in FIG. be able to.

[Adhesive resin]
In the present invention, “adhesive resin” means a polymer having adhesiveness by itself and having a mass average molecular weight (Mw) of 10,000 or more.
The mass average molecular weight (Mw) of the adhesive resin is preferably 10,000 to 2,000,000, more preferably 20,000 to 1,500,000, still more preferably 30,000 to 1,300,000, and still more preferably, from the viewpoint of improving the adhesive strength. Is 100,000 to 1,000,000.

Examples of the adhesive resin contained in the compositions (x1) and (x2) include acrylic resins, urethane resins, polyisobutylene resins, polyester resins, and olefin resins.
These adhesive resins may be used independently and may use 2 or more types together.
In addition, when these adhesive resins are copolymers having two or more kinds of structural units, the form of the copolymer is not particularly limited, and a block copolymer, a random copolymer, and a graft copolymer are not limited. Any of polymers may be used.

Furthermore, from the viewpoint of further improving the interfacial adhesion between the base material layer (Y), the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2), these pressure-sensitive adhesive resins have polymerizable functional groups. It is preferably an ultraviolet non-curable adhesive resin that does not have.
In the present specification, the polymerizable functional group means a group having a carbon-carbon double bond that can be polymerized by radical polymerization, and specifically includes a (meth) acryloyl group, a vinyl group, a vinyl ether group. , Allyl group, allyl ether group and the like.

The content of the adhesive resin in the compositions (x1) and (x2) is preferably 30 to 99.99 mass with respect to the total amount (100 mass%) of the active ingredients of the composition (x1) or (x2). %, More preferably 40 to 99.95% by mass, more preferably 50 to 99.90% by mass, still more preferably 55 to 99.80% by mass, and still more preferably 60 to 99.50% by mass.

In one embodiment of the present invention, the adhesive resin contained in the compositions (x1) and (x2) preferably contains an acrylic resin from the viewpoint of further improving the interfacial adhesion with the base material layer (Y). .
The acrylic resin is more preferably an ultraviolet non-curable resin having no polymerizable functional group.
From the above viewpoint, the content of the acrylic resin in the adhesive resin is preferably 30 to 100 mass with respect to the total amount (100 mass%) of the adhesive resin contained in the composition (x1) or (x2). %, More preferably 50 to 100% by mass, still more preferably 70 to 100% by mass, and still more preferably 85 to 100% by mass.

(Acrylic resin)
Examples of acrylic resins that can be used as adhesive resins include polymers containing structural units derived from alkyl (meth) acrylates having linear or branched alkyl groups, and (meth) acrylates having a cyclic structure. Examples thereof include a polymer containing a derived structural unit.

The mass average molecular weight (Mw) of the acrylic resin is preferably 100,000 to 1,500,000, more preferably 200,000 to 1,300,000, still more preferably 350,000 to 1,200,000, still more preferably 500,000 to 1,100,000. .

As an acrylic resin used in one embodiment of the present invention, an acrylic polymer having a structural unit (a1) derived from an alkyl (meth) acrylate (a1 ′) (hereinafter also referred to as “monomer (a1 ′)”) ( A0) is preferable, and together with the structural unit (a1), an acrylic copolymer (A1) having a structural unit (a2) derived from the functional group-containing monomer (a2 ′) (hereinafter also referred to as “monomer (a2 ′)”) ) Is more preferable.
The acrylic polymers (A0) and (A1) preferably have no polymerizable functional group.

The number of carbon atoms of the alkyl group contained in the monomer (a1 ′) is preferably 1 to 24, more preferably 1 to 12, still more preferably 1 to 8, and still more preferably 4 to 6 from the viewpoint of improving adhesive properties. It is.
The alkyl group contained in the monomer (a1 ′) may be a linear alkyl group or a branched alkyl group.

Examples of the monomer (a1 ′) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tridecyl ( Examples include meth) acrylate and stearyl (meth) acrylate.
These monomers (a1 ′) may be used alone or in combination of two or more.
As the monomer (a1 ′), butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferable, and butyl (meth) acrylate is more preferable.

The content of the structural unit (a1) is preferably 50 to 100% by weight, more preferably based on the total structural unit (100% by weight) of the acrylic polymer (A0) or the acrylic copolymer (A1). It is 60 to 99.9% by mass, more preferably 70 to 99.5% by mass, and still more preferably 80 to 99.0% by mass.

The functional group possessed by the monomer (a2 ′) refers to a functional group that reacts with a crosslinking agent to be described later and can serve as a crosslinking starting point or a functional group having a crosslinking accelerating effect. Can be mentioned.
That is, examples of the monomer (a2 ′) include a hydroxyl group-containing monomer, a carboxy group-containing monomer, an amino group-containing monomer, and an epoxy group-containing monomer.
These monomers (a2 ′) may be used alone or in combination of two or more.
As the monomer (a2 ′), a hydroxyl group-containing monomer and a carboxy group-containing monomer are preferable.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-hydroxybutyl (meth) ) And hydroxyalkyl (meth) acrylates such as 4-hydroxybutyl (meth) acrylate; and unsaturated alcohols such as vinyl alcohol and allyl alcohol.

Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids such as (meth) acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, maleic acid and citraconic acid, and anhydrides thereof. 2- (acryloyloxy) ethyl succinate, 2-carboxyethyl (meth) acrylate, and the like.

The content of the structural unit (a2) is preferably 0.1 to 40% by weight, more preferably 0.3 to 30%, based on the entire structural unit (100% by weight) of the acrylic copolymer (A1). % By mass, more preferably 0.5 to 20% by mass, still more preferably 0.7 to 10% by mass.

The acrylic copolymer (A1) may further have a structural unit (a3) derived from another monomer (a3 ′) other than the monomers (a1 ′) and (a2 ′).
In the acrylic copolymer (A1), the content of the structural units (a1) and (a2) is preferably 70 with respect to the total structural units (100% by mass) of the acrylic copolymer (A1). To 100% by mass, more preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, and still more preferably 95 to 100% by mass.

Examples of the monomer (a3 ′) include olefins such as ethylene, propylene, and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; diene monomers such as butadiene, isoprene, and chloroprene; cyclohexyl (meth) acrylate, It has a cyclic structure such as benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, imide (meth) acrylate, etc. (Meth) acrylate; styrene, α-methylstyrene, vinyl toluene, vinyl formate, vinyl acetate, acrylonitrile, (meth) acrylamide, (meth) acrylonitrile, (meth) acryloyl Ruhorin, N- vinylpyrrolidone and the like.

(Urethane resin)
The urethane resin that can be used as the adhesive resin is not particularly limited as long as it is a polymer having at least one of a urethane bond and a urea bond in at least one of the main chain and the side chain.
Specific examples of the urethane resin include a urethane prepolymer (UX) obtained by reacting a polyol and a polyvalent isocyanate compound.
The urethane prepolymer (UX) may be obtained by further subjecting to a chain extension reaction using a chain extender.

The mass average molecular weight (Mw) of the urethane resin is preferably 10,000 to 200,000, more preferably 12,000 to 150,000, still more preferably 15,000 to 100,000, and still more preferably 20,000 to 70,000.

Examples of the polyol used as a raw material for the urethane-based prepolymer (UX) include polyol compounds such as alkylene type polyols, polyether type polyols, polyester type polyols, polyester amide type polyols, polyester / polyether type polyols, and polycarbonate type polyols. Although it is mentioned, if it is a polyol, it will not specifically limit, Bifunctional diol and a trifunctional triol may be sufficient.
These polyols may be used independently and may use 2 or more types together.
Among these polyols, diols are preferable and alkylene type diols are more preferable from the viewpoints of availability, reactivity, and the like.

Examples of the alkylene type diol include alkane diols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol; ethylene glycol, propylene glycol, And alkylene glycols such as diethylene glycol and dipropylene glycol; polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polybutylene glycol; polyoxyalkylene glycols such as polytetramethylene glycol; and the like.
Among these alkylene type diols, glycols having a mass average molecular weight of 1000 to 3000 are preferable from the viewpoint of suppressing gelation when the reaction with a chain extender is performed.

Examples of the polyvalent isocyanate compound that is a raw material for the urethane prepolymer (UX) include aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates.
Examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2,4-TDI), 2 , 6-Tolylene diisocyanate (2,6-TDI), 4,4′-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4 ′ -Diphenyl ether diisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate, 1,4-tetramethylxylylene diisocyanate, 1,3-tetramethylxylylene diisocyanate and the like.
Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HMDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, and dodeca. Examples include methylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate.
Examples of the alicyclic polyisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4- Cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), 1,4-bis (isocyanatemethyl) cyclohexane, 1,4-bis (isocyanate) Methyl) cyclohexane and the like.
These polyisocyanate compounds may be a trimethylolpropane adduct type modified product of the above polyisocyanate, a burette type modified product reacted with water, or an isocyanurate type modified product containing an isocyanurate ring.

Among these polyvalent isocyanate compounds, 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2,4-TDI), 2, from the viewpoint of obtaining a urethane polymer having excellent adhesive properties. One or more selected from 6-tolylene diisocyanate (2,6-TDI), hexamethylene diisocyanate (HMDI), 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI) and modified products thereof are preferable. From the viewpoint of weather resistance, at least one selected from HMDI, IPDI, and modified products thereof is more preferable.

The isocyanate group content (NCO%) in the urethane-based prepolymer (UX) is preferably 0.5 to 12% by mass, more preferably 1 to 4% by mass, as measured according to JIS K 1603. is there.

As the chain extender, a compound having at least one of hydroxyl group and amino group, or a compound having at least three of hydroxyl group and amino group is preferable.

The compound having at least one of a hydroxyl group and an amino group is preferably at least one compound selected from the group consisting of aliphatic diols, aliphatic diamines, alkanolamines, bisphenols, and aromatic diamines.
Examples of the aliphatic diol include alkanediols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 1,7-heptanediol. Alkylene glycols such as ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol;
Examples of the aliphatic diamine include ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, and the like.
Examples of the alkanolamine include monoethanolamine, monopropanolamine, isopropanolamine and the like.
Examples of bisphenol include bisphenol A and the like.
Examples of the aromatic diamine include diphenylmethanediamine, tolylenediamine, xylylenediamine, and the like.

Examples of the compound having at least three hydroxyl groups and amino groups include polyols such as trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol; 1-amino-2,3-propanediol, 1-methyl And amino alcohols such as amino-2,3-propanediol and N- (2-hydroxypropylethanolamine); ethylene oxide or propylene oxide adducts of tetramethylxylylenediamine;

(Polyisobutylene resin)
The polyisobutylene resin (hereinafter also referred to as “PIB resin”) that can be used as the adhesive resin is not particularly limited as long as it has a polyisobutylene skeleton in at least one of the main chain and the side chain.

The mass average molecular weight (Mw) of the PIB resin is preferably 20,000 or more, more preferably 30,000 to 1,000,000, still more preferably 50,000 to 800,000, and still more preferably 70,000 to 600,000.

Examples of the PIB resin include polyisobutylene which is a homopolymer of isobutylene, a copolymer of isobutylene and isoprene, a copolymer of isobutylene and n-butene, a copolymer of isobutylene and butadiene, and these copolymers. Examples thereof include halogenated butyl rubber that has been brominated or chlorinated.

When the PIB-based resin is a copolymer, it is assumed that the structural unit composed of isobutylene is contained in the largest amount among all the structural units.
The content of the structural unit composed of isobutylene is preferably 80 to 100% by mass, more preferably 90 to 100% by mass, and still more preferably 95 to 100% by mass with respect to all the structural units (100% by mass) of the PIB resin. %.
These PIB resins may be used alone or in combination of two or more.

Moreover, when using a PIB resin, it is preferable to use together a PIB resin with a high mass average molecular weight and a PIB resin with a low mass average molecular weight.
More specifically, a PIB resin (p1) having a mass average molecular weight of 270,000 to 600,000 (hereinafter also referred to as “PIB resin (p1)”), and a PIB resin having a mass average molecular weight of 50,000 to 250,000 It is preferable to use the resin (p2) (hereinafter also referred to as “PIB resin (p2)”) in combination.
By using the PIB resin (p1) having a high mass average molecular weight, it is possible to improve the durability and weather resistance of the pressure-sensitive adhesive layer to be formed, and also improve the adhesive strength.
Further, by using the PIB resin (p2) having a low mass average molecular weight, it can be well compatible with the PIB resin (p1), and the PIB resin (p1) can be appropriately plasticized. The wettability of the layer to the adherend can be increased, and the adhesive properties, flexibility, and the like can be improved.

The mass average molecular weight (Mw) of the PIB resin (p1) is preferably 270,000 to 600,000, more preferably 290,000 to 480,000, still more preferably 310,000 to 450,000, and even more preferably 320,000 to 400,000. It is.
The mass average molecular weight (Mw) of the PIB resin (p2) is preferably 50,000 to 250,000, more preferably 80,000 to 230,000, still more preferably 140,000 to 220,000, and still more preferably 180,000 to 210,000. It is.

The content ratio of the PIB resin (p2) to 100 parts by mass of the PIB resin (p1) is preferably 5 to 55 parts by mass, more preferably 6 to 40 parts by mass, still more preferably 7 to 30 parts by mass, and even more. The amount is preferably 8 to 20 parts by mass.

(Polyester resin)
The polyester-based resin that can be used as the adhesive resin is a copolymer obtained by polycondensation reaction of an acid component and a diol component or a polyol component, and includes a modified product of the copolymer.
The polycondensation reaction is performed by a general polyesterification reaction such as a direct esterification method or a transesterification method.
These polyester resins may be used alone or in combination of two or more.

Examples of the acid component include terephthalic acid, isophthalic acid, phthalic anhydride, α-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid or esters thereof, pimelic acid, suberic acid, and azelain. Examples thereof include aliphatic dicarboxylic acids such as acid, sebacic acid, undecylenic acid, dodecanedicarboxylic acid or esters thereof; and alicyclic dicarboxylic acids such as 1,4-cyclohexahydrophthalic anhydride.

Examples of the diol component or polyol component include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, , 6-hexanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, 3-methylpentanediol, 2,2,3-trimethylpentanediol, diethylene glycol, triethylene glycol, dipropylene glycol, etc. An aliphatic glycol such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, and an aromatic glycol such as bisphenol A.

(Olefin resin)
The olefin resin that can be used as the adhesive resin is not particularly limited as long as it is a polymer having a structural unit derived from an olefin compound such as ethylene or propylene.
The said olefin resin may be used independently and may use 2 or more types together.

Specific examples of the olefin-based resin include polyethylenes such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene, polypropylene, copolymers of ethylene and propylene, ethylene and other α- Copolymers of olefins, copolymers of propylene and other α-olefins, copolymers of ethylene, propylene and other α-olefins, copolymers of ethylene and other ethylenically unsaturated monomers Examples thereof include ethylene (vinyl-vinyl acetate copolymer, ethylene-alkyl (meth) acrylate copolymer, etc.) and the like.
Examples of the α-olefin include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, 4-methyl-1-hexene and the like.
Examples of the ethylenically unsaturated monomer include vinyl acetate, alkyl (meth) acrylate, vinyl alcohol, and the like.

[Tackifier]
In one embodiment of the present invention, it is preferable that the compositions (x1) and (x2) further contain a tackifier from the viewpoint of making a double-sided PSA sheet with improved adhesive strength.
Here, the “tackifier” is a component that assists in improving the adhesive strength of the adhesive resin, and refers to an oligomer having a mass average molecular weight (Mw) of less than 10,000. It is a distinction.
The mass average molecular weight (Mw) of the tackifier is preferably 400 to 10000, more preferably 5000 to 8000, and still more preferably 800 to 5000.

Examples of tackifiers include rosin resins such as rosin resins, rosin ester resins, and rosin-modified phenol resins; hydrogenated rosin resins obtained by hydrogenating these rosin resins; terpene resins, aromatic modified terpene resins, and terpene phenols. Terpene resins such as epoxy resins; hydrogenated terpene resins obtained by hydrogenating these terpene resins; styrene obtained by copolymerizing a styrene monomer such as α-methylstyrene or β-methylstyrene with an aliphatic monomer Hydrogenated styrene resins obtained by hydrogenating these styrene resins; C5 systems obtained by copolymerizing C5 fractions such as pentene, isoprene, piperine, 1.3-pentadiene produced by thermal decomposition of petroleum naphtha Petroleum resin and hydrogenated petroleum resin of this C5 petroleum resin; indene and vinyl And C9 petroleum resins obtained by copolymerizing C9 fractions such as toluene and hydrogenated petroleum resins.
These tackifiers may be used alone or in combination of two or more different softening points and structures.

The softening point of the tackifier is preferably 60 to 170 ° C, more preferably 65 to 160 ° C, and still more preferably 70 to 150 ° C.
In the present specification, the “softening point” of the tackifier means a value measured according to JIS K2531.
Moreover, when using 2 or more types of several tackifier, it is preferable that the weighted average of the softening point of these several tackifier belongs to the said range.

The content of the tackifier in the compositions (x1) and (x2) is preferably 0.01 to 65 masses with respect to the total amount (100 mass%) of the active ingredients of the composition (x1) or (x2). %, More preferably 0.05 to 55% by mass, more preferably 0.1 to 50% by mass, still more preferably 0.5 to 45% by mass, and still more preferably 1.0 to 40% by mass.

The total content of the adhesive resin and the tackifier in the compositions (x1) and (x2) is preferably based on the total amount (100% by mass) of the active ingredients in the composition (x1) or (x2). Is 70% by mass or more, more preferably 80% by mass or more, more preferably 85% by mass or more, still more preferably 90% by mass or more, and still more preferably 95% by mass or more.

[Crosslinking agent]
In one embodiment of the present invention, when the compositions (x1) and (x2) contain an adhesive resin having a functional group such as the acrylic copolymer (A1) described above, the compositions (x1) and (x2) further contain a crosslinking agent. It is preferable to do.
The said crosslinking agent reacts with the functional group which the said adhesive resin has, and bridge | crosslinks resin.

Examples of the crosslinking agent include: tolylene diisocyanate, hexamethylene diisocyanate, and the like, and isocyanate-based crosslinking agents such as adducts thereof; epoxy-based crosslinking agents such as ethylene glycol glycidyl ether; hexa [1- (2-methyl) -aziridinyl ] Aziridine type crosslinking agents such as triphosphatriazine; Chelate type crosslinking agents such as aluminum chelate;
These crosslinking agents may be used independently and may use 2 or more types together.
Among these crosslinking agents, an isocyanate-based crosslinking agent is preferable from the viewpoints of increasing cohesive force and improving adhesive force, and availability.

Although content of a crosslinking agent is suitably adjusted with the number of functional groups which adhesive resin has, with respect to 100 mass parts of adhesive resins which have functional groups, such as said acrylic copolymer (A1). The amount is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 7 parts by mass, and still more preferably 0.05 to 4 parts by mass.

[Additives for adhesives]
In one aspect of the present invention, the compositions (x1) and (x2) are additives for pressure-sensitive adhesives used for general pressure-sensitive adhesives other than a crosslinking agent and a tackifier, as long as the effects of the present invention are not impaired. May be contained.
Examples of the adhesive additive include an antioxidant, a softener (plasticizer), a rust inhibitor, a pigment, a dye, a retarder, a reaction accelerator (catalyst), and an ultraviolet absorber.
These pressure-sensitive adhesive additives may be used alone or in combination of two or more.
When these pressure-sensitive adhesive additives are contained, the content of each pressure-sensitive adhesive additive is preferably 0.0001 to 20 parts by mass, more preferably 0.001 to 100 parts by mass of the adhesive resin. To 10 parts by mass, more preferably 0.005 to 5 parts by mass.

[Diluted solvent]
In one embodiment of the present invention, the compositions (x1) and (x2) may further contain a diluting solvent together with the various active ingredients described above, and may be in the form of a solution.
The dilution solvent may be water or an organic solvent.
Examples of the organic solvent include toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, isopropyl alcohol, t-butanol, s-butanol, acetylacetone, cyclohexanone, n-hexane, and cyclohexane.
In addition, the dilution solvent contained in composition (x1) and (x2) may be used independently, and may use 2 or more types together.

When the compositions (x1) and (x2) are in the form of a solution containing a diluting solvent, the active ingredient concentrations of the compositions (x1) and (x2) are each independently preferably preferably 0.1 to 60 The mass is more preferably 0.5 to 50 mass%, still more preferably 1.0 to 40 mass%.

<Composition (y)>
The composition (y) which is a forming material of the base material layer (Y) contains a non-adhesive resin selected from the group consisting of an acrylic urethane resin and an olefin resin.
In the present invention, the “non-adhesive resin” means a non-adhesive polymer belonging to acrylic urethane resin or olefin resin and having a mass average molecular weight (Mw) of 10,000 or more.
In addition, when the non-adhesive resin is a copolymer having two or more kinds of structural units, the form of the copolymer is not particularly limited, and a block copolymer, a random copolymer, and a graft copolymer Any of them may be combined.
Furthermore, in one aspect of the present invention, from the viewpoint of further improving the interfacial adhesion between the base material layer (Y), the first pressure-sensitive adhesive layer (X1), and the second pressure-sensitive adhesive layer (X2), the composition (y) It is preferable that the non-adhesive resin contained in is an ultraviolet non-curable resin having no polymerizable functional group.

Moreover, in one aspect of the present invention, the composition (y) may contain a resin other than an acrylic urethane-based resin and an olefin-based resin as long as the effects of the present invention are not impaired. You may contain the additive for base materials contained in the base material which a sheet | seat has.

The content of the non-adhesive resin in the composition (y) is preferably 50 to 100% by mass, more preferably 65 to 100% by mass with respect to the total amount (100% by mass) of the active ingredients in the composition (y). %, More preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, and still more preferably 95 to 100% by mass.

(Acrylic urethane resin)
Examples of the acrylic urethane-based resin contained as the non-adhesive resin in the composition (y) include a reaction product of an acrylic polyol compound and an isocyanate compound, and a linear urethane prepolymer having ethylenically unsaturated groups at both ends. Examples thereof include a copolymer obtained by polymerizing a polymer (UY) and a vinyl compound (VY) containing a (meth) acrylic ester.

An acrylic urethane resin (hereinafter also referred to as “acrylic urethane resin (I)”), which is a reaction product of an acrylic polyol compound and an isocyanate compound, has a main chain of the acrylic resin as a skeleton, and the intermolecular relationship between the molecules. It has a chemical structure that is cured by crosslinking with urethane bonds.
Since the acrylic resin that is the main chain is rich in rigidity, it has a structural unit derived from an isocyanate compound that is highly resistant to tensile stress and has a high reactivity, and therefore has the first pressure-sensitive adhesive layer (X1) and the first adhesive layer. It is thought that it is excellent also in adhesiveness with the adhesive resin contained in 2 adhesive layer (X2), and can contribute to the improvement of interface adhesiveness.

On the other hand, an acrylic urethane-based resin, which is a copolymer obtained by polymerizing a linear urethane prepolymer (UY) having an ethylenically unsaturated group at both ends and a vinyl compound (VY) containing a (meth) acrylic acid ester ( Hereinafter, the “acrylic urethane resin (II)” is a (meth) acrylic acid ester at both ends of the linear urethane prepolymer (UY) with the main chain of the linear urethane prepolymer (UY) as the skeleton. It has a structural unit derived from the vinyl compound (VY) containing.
Since acrylic urethane resin (II) has a portion derived from linear urethane polymer (UY) between acrylic sites in the main chain skeleton, the distance between crosslinking points is longer than that of acrylic urethane resin (I). The molecular structure tends to be a two-dimensional structure (network structure).
Further, since the urethane prepolymer (UY) of the main chain is linear, the stretching effect is high when an external force is applied.
Furthermore, the side chain of the structural unit derived from the vinyl compound (VY) containing the (meth) acrylic acid ester is easily entangled with the adhesive resin in the first adhesive layer (X1) and the second adhesive layer (X2). It has a structure.
Therefore, the use of acrylic urethane resin (II) as the material for forming the base layer (Y) improves the interfacial adhesion with the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2). It is thought that it can contribute to.

The mass average molecular weight (Mw) of acrylic urethane resins such as acrylic urethane resins (I) and (II) is preferably 2,000 to 500,000, more preferably 4,000 to 300,000, and even more preferably 5 1,000 to 200,000, and more preferably 10,000 to 150,000.
The acrylic urethane resins such as acrylic urethane resins (I) and (II) are preferably ultraviolet non-curable resins having no polymerizable functional group.

In one embodiment of the present invention, the acrylic urethane resin (II) is preferably used as the acrylic urethane resin contained in the composition (y) as a non-adhesive resin.
Hereinafter, the acrylic urethane resins (I) and (II) will be described.

(Acrylic urethane resin (I))
As an acrylic polyol compound that is a raw material of the acrylic urethane-based resin (I), a structural unit (b1) derived from an alkyl (meth) acrylate (b1 ′) (hereinafter also referred to as “monomer (b1 ′)”), An acrylic copolymer (B1) having a structural unit (b2) derived from a hydroxyl group-containing monomer (b2 ′) (hereinafter also referred to as “monomer (b2 ′)”) is preferable.

The number of carbon atoms of the alkyl group contained in the monomer (b1 ′) is preferably 1 to 12, more preferably 4 to 8, and still more preferably 4 to 6.
The alkyl group contained in the monomer (b1 ′) may be a straight chain alkyl group or a branched chain alkyl group.
Specific examples of the monomer (b1 ′) include the same monomers as the monomer (a1 ′) described above.
In addition, a monomer (b1 ') may be used independently and may use 2 or more types together.
However, as the monomer (b1 ′), butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferable, and butyl (meth) acrylate is more preferable.

The content of the structural unit (b1) is preferably 60 to 99.9% by mass, more preferably 70 to 99.7% by mass with respect to the total structural unit (100% by mass) of the acrylic copolymer (B1). %, More preferably 80 to 99.5% by mass.

Moreover, as a monomer (b2 '), the same thing as the hydroxyl-containing monomer which can be selected as said monomer (a2') is mentioned.
In addition, a monomer (b2 ') may be used independently and may use 2 or more types together.

The content of the structural unit (b2) is preferably 0.1 to 40% by weight, more preferably 0.3 to 30% by weight with respect to the total structural unit (100% by weight) of the acrylic copolymer (B1). %, And more preferably 0.5 to 20% by mass.

The acrylic copolymer (B1) may further have a structural unit (b3) derived from another monomer (b3 ′) other than the monomers (b1 ′) and (b2 ′).
Examples of the monomer (b3 ′) include functional group-containing monomers other than the hydroxyl group-containing monomer that can be selected as the above-mentioned monomer (a2 ′), and the same monomers as the above-mentioned monomer (a3 ′).

In the acrylic copolymer (B1), the content of the structural units (b1) and (b2) is preferably 70 with respect to the total structural units (100% by mass) of the acrylic copolymer (B1). To 100% by mass, more preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, and still more preferably 95 to 100% by mass.

On the other hand, examples of the isocyanate compound used as the raw material for the acrylic urethane resin (I) include the same polyvalent isocyanate compounds used as the raw material for the urethane prepolymer (U1).
However, as an isocyanate compound, from the viewpoint of stretchability when an external force is applied, an isocyanate compound having no aromatic ring is preferable, and an aliphatic polyisocyanate and an alicyclic polyisocyanate are more preferable.

In the acrylic urethane resin (I), the ratio of the structural unit derived from the acrylic polyol compound to the structural unit derived from the isocyanate compound [acryl polyol compound / isocyanate compound] is preferably 10/90 by mass ratio. Is 90/90, more preferably 20/80 to 80/20, still more preferably 30/70 to 70/30, and still more preferably 40/60 to 60/40.

(Acrylic urethane resin (II))
Examples of the linear urethane prepolymer (UY) that is a raw material for the acrylic urethane resin (II) include a reaction product of a diol and a diisocyanate compound.
The said diol and diisocyanate compound may be used independently and may use 2 or more types together.
The mass average molecular weight of the linear urethane prepolymer (UY) is preferably 1,000 to 300,000, more preferably 3,000 to 200,000, still more preferably 5,000 to 100,000, and still more preferably 10,000 to 80,000, particularly preferably 20,000 to 60,000.

Examples of the diol constituting the linear urethane prepolymer (UY) include alkylene glycol, polyether type diol, polyester type diol, polyester amide type diol, polyester / polyether type diol, and polycarbonate type diol.
Of these diols, polycarbonate diols are preferred.

Examples of the diisocyanate compound constituting the linear urethane prepolymer (UY) include aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates. From the viewpoint of stretchability when an external force is applied, alicyclic Diisocyanate is preferred.
In addition, as a specific diisocyanate compound, what corresponds to a diisocyanate compound is mentioned among the compounds illustrated as a polyisocyanate used as the raw material of the above-mentioned urethane type prepolymer (UX).

Further, the linear urethane prepolymer (UY) may be obtained by performing a chain extension reaction using a chain extender together with a diol and a diisocyanate compound.
Examples of the chain extender include the same chain extenders as those exemplified as the chain extender that can be used in the synthesis of the urethane prepolymer (UX).

In one embodiment of the present invention, the linear urethane prepolymer (UY) has an ethylenically unsaturated group at both ends.
As a method for introducing an ethylenically unsaturated group into both ends of the urethane prepolymer (UY), an NCO group at the end of the urethane prepolymer obtained by reacting a diol and a diisocyanate compound, and a hydroxyalkyl (meth) acrylate are used. The method of making it react is mentioned.
Examples of the hydroxyalkyl (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-hydroxy Examples thereof include butyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate.

As a vinyl compound (VY) used as the raw material of acrylic urethane type resin (II), at least (meth) acrylic acid ester is included.
The (meth) acrylic acid ester is the same as that corresponding to the (meth) acrylic acid ester among the monomers (a1 ′) to (a3 ′) used as the raw material of the above-mentioned acrylic copolymer (A1). Things.
However, as the (meth) acrylic acid ester, at least one selected from alkyl (meth) acrylate and hydroxyalkyl (meth) acrylate is preferable, and it is more preferable to use alkyl (meth) acrylate and hydroxyalkyl (meth) acrylate together. preferable.

When alkyl (meth) acrylate and hydroxyalkyl (meth) acrylate are used in combination, the proportion of hydroxyalkyl (meth) acrylate to 100 parts by mass of alkyl (meth) acrylate is preferably 0.1 to 100 parts by mass, The amount is preferably 0.5 to 30 parts by mass, more preferably 1.0 to 20 parts by mass, and still more preferably 1.5 to 10 parts by mass.

The number of carbon atoms in the alkyl group of the alkyl (meth) acrylate is preferably 1 to 24, more preferably 1 to 12, still more preferably 1 to 8, and still more preferably 1 to 3.
As the said alkyl (meth) acrylate, the same thing as what was illustrated as a monomer (a1 ') used as the raw material of the above-mentioned acrylic copolymer (A1) is mentioned.

Moreover, as hydroxyalkyl (meth) acrylate, the same thing as what was illustrated as hydroxyalkyl (meth) acrylate used in order to introduce | transduce an ethylenically unsaturated group into the both ends of the above-mentioned urethane prepolymer (UY) is mentioned. It is done.

Examples of vinyl compounds other than (meth) acrylic acid esters include aromatic hydrocarbon vinyl compounds such as styrene, α-methylstyrene, and vinyl toluene; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; vinyl acetate and vinyl propionate. Polar group-containing monomers such as (meth) acrylonitrile, N-vinylpyrrolidone, (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, and meta (acrylamide).
These may be used alone or in combination of two or more.

In one embodiment of the present invention, the content of (meth) acrylic acid ester in the vinyl compound (VY) used as the raw material for the acrylic urethane resin (II) is the total amount (100% by mass) of the vinyl compound (VY). Is preferably 40 to 100% by mass, more preferably 65 to 100% by mass, still more preferably 80 to 100% by mass, and still more preferably 90 to 100% by mass.

In one embodiment of the present invention, the total content of alkyl (meth) acrylate and hydroxyalkyl (meth) acrylate in vinyl compound (VY) used as a raw material for acrylic urethane resin (II) is the vinyl compound (VY). Is preferably 40 to 100% by mass, more preferably 65 to 100% by mass, still more preferably 80 to 100% by mass, and still more preferably 90 to 100% by mass with respect to the total amount (100% by mass).

The acrylic urethane resin (II) can be obtained by polymerizing a linear urethane prepolymer (UY) as a raw material and a vinyl compound (VY).
As a specific polymerization method, a radical generator is blended in an organic solvent together with the linear urethane prepolymer (UY) and vinyl compound (VY) as raw materials, and both ends of the linear urethane prepolymer (UY). It can be synthesized by a radical polymerization reaction of a vinyl compound (VY) starting from an ethylenically unsaturated group.
Examples of the radical generator used include diazo compounds such as azobisisobutyronitrile, benzoyl peroxide, and the like.
In this radical polymerization reaction, a chain transfer agent such as a thiol group-containing compound may be added to the solvent to adjust the polymerization degree of acrylic.

In the acrylic urethane resin (II) used in one embodiment of the present invention, the content ratio of the structural unit derived from the linear urethane prepolymer (UY) to the structural unit derived from the vinyl compound (VY) [(UY) / (VY)] is preferably 10/90 to 80/20, more preferably 20/80 to 70/30, still more preferably 30/70 to 60/40, still more preferably 35 / 65 to 55/45.

(Olefin resin)
The olefin resin contained as the non-adhesive resin in the composition (y) is a polymer having at least a structural unit derived from an olefin monomer.
The olefin resin is preferably an ultraviolet non-curable resin having no polymerizable functional group.
The olefin monomer is preferably an α-olefin having 2 to 8 carbon atoms, and specifically includes ethylene, propylene, butylene, isobutylene, 1-hexene and the like.
Among these, ethylene and propylene are preferable.

Specific olefinic resins, for example, ultra low density polyethylene (VLDPE, density: 880 kg / ^{m 3} or more 910 kg / ^m less than ^3), low density polyethylene (LDPE, density: 910 kg / ^{m 3} or more 915 kg / ^m less than ³ ), Medium density polyethylene (MDPE, density: 915 kg / m ³ or more and less than 942 kg / m ³ ), high density polyethylene (HDPE, density: 942 kg / m ³ or more), linear low density polyethylene, etc .; polypropylene resin (PP); polybutene resin (PB); ethylene-propylene copolymer; olefin elastomer (TPO); ethylene-vinyl acetate copolymer (EVA); ethylene-propylene- (5-ethylidene-2-norbornene), etc. Olefin terpolymers; and the like.

In one embodiment of the present invention, the olefin resin may be a modified olefin resin further modified by one or more selected from acid modification, hydroxyl group modification, and acrylic modification.

For example, as an acid-modified olefin resin obtained by subjecting an olefin resin to acid modification, a modified polymer obtained by graft polymerization of the above-mentioned unmodified olefin resin with an unsaturated carboxylic acid or its anhydride. Is mentioned.
Examples of the unsaturated carboxylic acid or anhydride thereof include maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, tetrahydrophthalic acid, aconitic acid, (meth) acrylic acid, maleic anhydride, itaconic anhydride. , Glutaconic anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride, and the like.
In addition, unsaturated carboxylic acid or its anhydride may be used independently and may use 2 or more types together.

As an acrylic modified olefin resin obtained by subjecting an olefin resin to acrylic modification, a modification obtained by graft polymerization of an alkyl (meth) acrylate as a side chain to the above-mentioned unmodified olefin resin as a main chain. A polymer is mentioned.
The number of carbon atoms in the alkyl group of the alkyl (meth) acrylate is preferably 1-20, more preferably 1-16, and still more preferably 1-12.
As said alkyl (meth) acrylate, the same thing as the compound which can be selected as said monomer (a1 ') is mentioned, for example.

Examples of the hydroxyl group-modified olefin resin obtained by subjecting an olefin resin to hydroxyl group modification include a modified polymer obtained by graft polymerization of a hydroxyl group-containing compound to the above-mentioned unmodified olefin resin, which is the main chain.
As said hydroxyl-containing compound, the same thing as the hydroxyl-containing monomer which can be selected as said monomer (a2 ') is mentioned.

The mass average molecular weight (Mw) of the olefin resin is preferably 2,000 to 1,000,000, more preferably 10,000 to 500,000, still more preferably 20,000 to 400,000, and even more preferably 50,000 to 300,000. is there.

(Resin other than acrylic urethane resin and olefin resin)
In one embodiment of the present invention, the composition (y) may contain a resin other than the acrylic urethane-based resin and the olefin-based resin as long as the effects of the present invention are not impaired.
Examples of such resins include vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer; polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate. Polyester resin such as phthalate; polystyrene; acrylonitrile-butadiene-styrene copolymer; cellulose triacetate; polycarbonate; polyurethane not applicable to acrylic urethane resin; polymethylpentene; polysulfone; polyetheretherketone; polyethersulfone; Sulfides; Polyimide resins such as polyetherimide and polyimide; Polyamide resins; Acrylic resins; Fluorine resins and the like.

However, from the viewpoint of further improving the interfacial adhesion between the base material layer (Y), the first pressure-sensitive adhesive layer (X1), and the second pressure-sensitive adhesive layer (X2), the acrylic urethane-based resin and olefin in the composition (y) The content ratio of the resin other than the resin is preferably as small as possible.
As a specific content of the resin other than the acrylic urethane resin and the olefin resin, the total amount of the non-adhesive resin selected from the group consisting of the acrylic urethane resin and the olefin resin contained in the composition (y) is 100. The amount is preferably less than 30 parts by weight, more preferably less than 20 parts by weight, more preferably less than 10 parts by weight, still more preferably less than 5 parts by weight, and still more preferably less than 1 part by weight with respect to parts by weight.

(Substrate additive)
1 aspect of this invention WHEREIN: The composition (y) may contain the base material additive contained in the base material which a general adhesive sheet has in the range which does not impair the effect of this invention.
Examples of such base material additives include ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, slip agents, antiblocking agents, and colorants.
These base material additives may be used alone or in combination of two or more.
In the case of containing these base material additives, the content of each base material additive is preferably 0.0001 to 20 parts by mass, more preferably 0 to 100 parts by mass of the non-adhesive resin. 0.001 to 10 parts by mass, still more preferably 0.005 to 5 parts by mass.

(Diluted solvent)
In one embodiment of the present invention, the composition (y) may further contain a diluting solvent together with the various active ingredients described above, and may be in the form of a solution.
The dilution solvent may be water or an organic solvent.
As an organic solvent, the same organic solvent used when preparing the above-mentioned composition (x1) and (x2) in the form of a solution is mentioned.
In addition, the dilution solvent contained in a composition (y) may be used independently, and may use 2 or more types together.

When the composition (y) is in the form of a solution containing a diluting solvent, the active ingredient concentration of the composition (y) is preferably independently 0.1 to 60% by mass, more preferably 0. It is 5 to 50% by mass, more preferably 1.0 to 40% by mass.

(Physical properties of the base material layer (Y) formed from the composition (y))
The elongation at break of the base material layer (Y) formed from the composition (y) is preferably 100% or more, more preferably 120% or more, still more preferably 200% or more, and still more preferably 350% or more. In addition, it is usually 1000% or less.
The breaking strength of the base material layer (Y) formed from the composition (y) is preferably 30 MPa or more, more preferably 60 MPa or more, and usually 300 MPa or less, preferably 200 MPa or less.
In addition, the breaking elongation and breaking strength of said base material layer (Y) are from the coating film (y ') which consists of a composition (y) on the same application quantity and drying conditions as the case where a double-sided adhesive sheet is manufactured. The formed base material layer (Y) is the object to be measured. The specific measurement method is as described in the examples.

<Physical properties of the laminate>
The thickness of the laminate of the double-sided pressure-sensitive adhesive sheet of one embodiment of the present invention is preferably 2 to 90 μm, more preferably 4 to 75 μm, still more preferably 6 to 60 μm, and still more preferably 8 to 45 μm.

The thicknesses of the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2) are each independently preferably 0.5 to 50 μm, more preferably 1 to 40 μm, still more preferably 2 to 30 μm. More preferably, the thickness is 3 to 20 μm.

The thickness of the base material layer (Y) is preferably 0.3 to 50.0 μm, more preferably 0.5 to 30.0 μm, still more preferably 0.7 to 15.0 μm, and still more preferably 1.0. -8.0 μm.

In the present specification, the thickness of the laminate is a value measured using a constant pressure thickness measuring instrument based on JIS K6783, Z1702, and Z1709, and specifically measured based on the method described in the examples. Means the value.
In addition, the thickness of each layer constituting the laminate may be measured by the same method as the thickness of the laminate described above. For example, a cross section of the laminate cut in the thickness direction is observed with a scanning electron microscope. Then, the ratio of the thicknesses of the respective layers may be measured and calculated from the thickness of the laminate measured by the method described above.

In the double-sided pressure-sensitive adhesive sheet of one embodiment of the present invention, the thickness ratio of the base material layer (Y) to the total thickness 100 of the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2) is preferably It is 1 to 100, more preferably 3 to 90, still more preferably 4 to 70, still more preferably 7 to 50, still more preferably 10 to 30, and particularly preferably 11 to 22.

The ratio [X1 / X2] of the thickness of the first pressure-sensitive adhesive layer (X1) to the thickness of the second pressure-sensitive adhesive layer (X2) is preferably 10/90 to 90/10, more preferably 20/80 to 80 / 20, more preferably 30/70 to 70/30, still more preferably 40/60 to 60/40.

The haze of the laminate of the double-sided pressure-sensitive adhesive sheet of one embodiment of the present invention is preferably 5.00% or less, more preferably 4.00% or less, still more preferably 3.00% or less, and still more preferably 2. 00% or less, particularly preferably 1.00% or less.
In the present specification, the haze is a value measured according to JIS K 7136: 2000, and specifically, a value measured by the method described in Examples.

The total light transmittance of the laminate which the double-sided pressure-sensitive adhesive sheet of one embodiment of the present invention has is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more.
In this specification, the total light transmittance is a value measured in accordance with JIS K7361-1: 1997, and specifically, a value measured by the method described in the examples.

In addition, as for the said laminated body which the double-sided adhesive sheet of this invention has as above-mentioned, a mixed layer arises between two coating films in the drying process of a coating film, and a 1st adhesive layer (X1) and a base material layer (Y) And the interface between the base material layer (Y) and the second pressure-sensitive adhesive layer (X2) tend to be unclear enough to disappear.
Therefore, light scattering due to the difference in refractive index due to the difference in the formation material of each layer hardly occurs, and as a result, the laminate is likely to have a low haze and a high total light transmittance.

As the adhesive force on the respective adhesive surfaces of the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2) of the double-sided pressure-sensitive adhesive sheet of one aspect of the present invention, each independently, preferably 3.0 N / 25 mm or more More preferably, it is 5.0 N / 25 mm or more, More preferably, it is 7.0 N / 25 mm or more, More preferably, it is 10.0 N / 25 mm or more, More preferably, it is 18.0 N / 25 mm or more.
In addition, the value of said adhesive force means the value measured by the method as described in an Example.

[Release material]
The double-sided pressure-sensitive adhesive sheet of one embodiment of the present invention may further have a release material on the sticking surface of the pressure-sensitive adhesive layer.
In addition, it is preferable that the two peeling materials which hold | pick a laminated body are adjusted so that the difference in peeling force may differ.
As the release material, a release sheet that has been subjected to a double-sided release process, a release sheet that has been subjected to a single-sided release process, or the like is used. Examples include a release material coated on a release material substrate.

Examples of the base material for the release material include papers such as high-quality paper, glassine paper, and kraft paper; polyester resin films such as polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin; and olefins such as polypropylene resin and polyethylene resin. A plastic film such as a resin film;

Examples of the release agent include silicone-based resins, olefin-based resins, isoprene-based resins, rubber-based elastomers such as butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, and fluorine-based resins.

The thickness of the release material is not particularly limited, but is preferably 10 to 200 μm, more preferably 25 to 170 μm, and still more preferably 35 to 80 μm.

[Method for producing double-sided PSA sheet]
The method for producing the double-sided PSA sheet of the present invention is preferably a method having the following steps (1) to (2).
Step (1): a coating film (x1 ′) composed of the composition (x1), a coating film (y ′) composed of the composition (y), and a coating film (x2 ′) composed of the composition (x2) A process of directly stacking layers in this order.
-Process (2): The process of drying a coating film (x1 '), a coating film (y'), and a coating film (x2 ') simultaneously, and forming the said laminated body.
Hereinafter, each step will be described.

<Step (1)>
In the step (1), as a method for forming the coating film (x1 ′), the coating film (y ′), and the coating film (x2 ′), for example, after forming the coating film (x1 ′), the coating film (x1 A sequential formation method may be used in which a coating film (y ') is formed on') and a coating film (x2 ') is further formed on the coating film (y'). From the viewpoint of productivity, the coating film ( A method in which x1 ′), (y ′), and (x2 ′) are simultaneously applied is preferable.
In addition, from the viewpoint of handleability, the coating film (x1 ′) is preferably formed on the release treatment surface of the release material.

Examples of the coater used for sequential formation include a spin coater, a spray coater, a bar coater, a knife coater, a roll coater, a knife roll coater, a blade coater, a gravure coater, a curtain coater, and a die coater.

As the coater used for simultaneous application, a multilayer coater can be mentioned, and specifically, a curtain coater, a die coater and the like can be mentioned. Among these, a die coater is preferable from the viewpoint of operability.

In addition, it is preferable that a composition (x1), a composition (y), and a composition (x2) contain a dilution solvent further from a viewpoint of making each coating film easy to form and improving productivity.
As a dilution solvent, water or the above-mentioned organic solvent can be used.
Moreover, the active ingredient density | concentration of the solution obtained by mix | blending a dilution solvent with each composition is as above-mentioned.

The coating amount of the coating film (x1 ') and film (x2') are each independently preferably 0.5 ~ 50.0g / ^{m 2,} more preferably 1.0 ~ 40.0g / ^{m 2,} further It is preferably 2.0 to 30.0 g / m ² , and more preferably 3.0 to 20.0 g / m ² .

The coating amount of the coating film (y ′) is preferably 0.3 to 50.0 g / m ² , more preferably 0.5 to 30.0 g / m ² , still more preferably 0.7 to 15.0 g / m. ² and more preferably 1.0 to 8.0 g / m ² .

The ratio of the coating amount of the coating film (y ′) to the total coating amount 100 of the coating film (x1 ′) and the coating film (x2 ′) is preferably 1 to 100, more preferably 4 to 70, still more preferably. It is 7 to 50, particularly preferably 10 to 30.

In addition, in this process (1), after forming the coating film of 1 layer or more of a coating film (x1 '), a coating film (y'), and a coating film (x2 '), before the process (2), You may perform the predrying process of the grade which does not advance the hardening reaction of a coating film.
For example, a pre-drying treatment may be performed each time a coating film (x1 ′), a coating film (y ′), and a coating film (x2 ′) are formed. After forming the two-layer coating film of the coating film (y ′), the coating film (x2 ′) may be formed after performing a pre-drying treatment collectively.
In this step (1), the drying temperature at the time of performing the pre-drying treatment is usually appropriately set within a temperature range in which the formed coating film does not cure, but preferably in the step (2). Below the drying temperature.
The specific drying temperature indicated by the phrase “below the drying temperature in step (2)” is preferably 10 to 45 ° C., more preferably 10 to 34 ° C., and further preferably 15 to 30 ° C.

<Step (2)>
In the step (2), the coating film (x1 ′), the coating film (y ′), and the coating film (x2 ′) are simultaneously dried to form the laminate.
In this drying process, a mixed layer is formed at the interface between the coating film (x1 ′) and the coating film (y ′) and at the interface between the coating film (y ′) and the coating film (x2 ′). The first pressure-sensitive adhesive layer (X1) and the base material layer (Y), and the base material layer (Y) and the second pressure-sensitive adhesive layer (X2) are dried and cured in an intertwined state with the non-adhesive resin. It is considered that the interfacial adhesion of the material significantly improves.

The drying temperature of the coating film in the step (2) is preferably 60 to 150 ° C, more preferably 70 to 145 ° C, still more preferably 80 to 140 ° C, and still more preferably 90 to 135 ° C.

<The manufacturing method of the double-sided adhesive sheet which has adhesive layers other than a 1st and 2nd adhesive layer>
When the double-sided pressure-sensitive adhesive sheet of one embodiment of the present invention has a configuration including pressure-sensitive adhesive layers other than the first and second pressure-sensitive adhesive layers, as in the double-sided pressure-sensitive adhesive sheet 4 shown in FIG. A pressure-sensitive adhesive layer other than the two pressure-sensitive adhesive layers may be separately formed and attached to the formed laminate, or may be formed simultaneously with the formation of the laminate.
For example, the third pressure-sensitive adhesive layer (X3) and the fourth pressure-sensitive adhesive layer (X4) included in the double-sided pressure-sensitive adhesive sheet 4 shown in FIG. 1 (d) are formed by any of the following (i) and (ii). Can do.

(I): The third pressure-sensitive adhesive layer (X3) 123 is formed on the release treatment surface of the release material 131, and the coating film (x1 ′), ( y ′) and (x2 ′) are formed, and these coating films are dried at the same time to form the laminate 10. Then, the second adhesive layer (X2) 122 of the laminate 10 has a Four adhesive layers (X4) 124 are laminated.
In addition, in said (i), the 4th adhesive layer (X4) is a coating film which consists of a composition which is a formation material of a 4th adhesive layer (X4) on the sticking surface of a 2nd adhesive layer (X2). May be formed by drying, and a fourth pressure-sensitive adhesive layer (X4) formed on a release-treated surface of a separate release material is applied to the surface of the second pressure-sensitive adhesive layer (X2). May be.

Method (ii): A coating film (x3 ′), a coating film (x1 ′), and a coating film made of a composition that is a material for forming the third pressure-sensitive adhesive layer (X3) 123 on the release treatment surface of the release material 131 (Y '), a coating film (x2'), and a coating film (x4 ') composed of a composition that is a forming material of the fourth pressure-sensitive adhesive layer (X4) 124 is applied in this order, and these coating films are simultaneously applied. It dries and forms the 3rd adhesive layer (X3) 123 and the 4th adhesive layer (X4) 124 simultaneously with formation of the laminated body 10. FIG.
In addition, in said (ii), after forming the laminated body 10, a 4th adhesive layer (X4) is the 4th adhesive layer on the sticking surface of the 2nd adhesive layer (X2) 122 of the laminated body 10. The coating film made of the composition which is the forming material of (X4) may be formed by drying, and the fourth pressure-sensitive adhesive layer (X4) formed on the release-treated surface of the release material prepared separately is used as the second pressure-sensitive adhesive. You may affix and form on the sticking surface of an agent layer (X2).
Further, at least when the coating film (x3 ′), the coating film (x1 ′), the coating film (y ′), and the coating film (x2 ′) are simultaneously dried, The composition (x1) on which the coating film (x1 ′) is formed is different from each other.
Similarly, at least when the coating film (x1 ′), the coating film (y ′), the coating film (x2 ′), and the coating film (x4 ′) are simultaneously dried, the composition in which the coating film (x4 ′) is formed. The product and the composition (x2) on which the coating film (x2 ′) is formed are different from each other.

The present invention will be specifically described with reference to the following examples, but the present invention is not limited to the following examples. In addition, the physical-property value in the following manufacture examples and Examples is a value measured by the following method.

<Mass average molecular weight (Mw)>
Using a gel permeation chromatograph (product name “HLC-8020” manufactured by Tosoh Corporation), measurement was performed under the following conditions, and values measured in terms of standard polystyrene were used.
(Measurement condition)
Column: “TSK guard column HXL-L”, “TSK gel G2500HXL”, “TSK gel G2000HXL”, and “TSK gel G1000HXL” (both manufactured by Tosoh Corporation) Column temperature: 40 ° C.
・ Developing solvent: Tetrahydrofuran ・ Flow rate: 1.0 mL / min

<Measurement of laminate thickness>
It was measured using a constant pressure thickness measuring instrument (model number: “PG-02J”, standard: conforming to JIS K6783, Z1702, Z1709) manufactured by Teclock Co., Ltd.
Specifically, after measuring the total thickness of the double-sided pressure-sensitive adhesive sheet to be measured, the value obtained by subtracting the thickness of the release material measured in advance was defined as the “thickness of the laminate”.

<Measurement of thickness of each layer>
Using a scanning electron microscope (product name “S-4700”, manufactured by Hitachi, Ltd.), a cross section in the thickness direction of the laminate was observed, and the first pressure-sensitive adhesive layer (X1) with respect to the thickness of the laminate The thickness ratio of each of the base material layer (Y) and the second pressure-sensitive adhesive layer (X2) was measured.
And based on the thickness ratio of each layer, the thickness of each layer was computed from the actual value of the "thickness of a laminated body" measured by the above-mentioned method.

Production Example 1
(Preparation of composition (x-1))
An acrylic resin having a structural unit derived from a raw material monomer consisting of an acrylic copolymer (n-butyl acrylate (BA) / acrylic acid (AAc) = 98.0 / 2.0 (mass ratio)) which is an adhesive resin Copolymer, mass average molecular weight: 1 million, dilution solvent: ethyl acetate, solid content concentration: 15% by mass) 100 parts by mass (solid content ratio), as a tackifier, rosin resin (manufactured by Harima Chemical Co., Ltd., Product name “Harry Star TF”, softening point: 75 to 85 ° C. 50 parts by mass (solid content ratio), and as crosslinking agent, isocyanate-based crosslinking agent (product name “Coronate L”, manufactured by Tosoh Corporation), solid content Concentration: 75% by mass) 1.5 parts by mass (solid content ratio) mixed and mixed, further diluted with toluene, stirred uniformly, and a solid content concentration (active ingredient concentration) of 30% by mass Prepare (x-1) .

Production Example 2
(Preparation of composition (y-1))
Non-adhesive resin, acid-modified olefin resin solution (Mitsubishi Chemical Co., Ltd., product name “Unistal H-200”, mass average molecular weight: 145,000, glass transition temperature: −53 ° C., dilution solvent : Mixed solvent of methylcyclohexane and methyl ethyl ketone, solid content concentration (active ingredient concentration): 20% by mass) was used as the composition (y-1).

Production Example 3
(Preparation of composition (y-2))
(1) Synthesis of urethane prepolymer In a reaction vessel under a nitrogen atmosphere, isophorone diisocyanate is mixed with the hydroxyl group of polycarbonate diol and isophorone diisocyanate with respect to 100 parts by mass (solid content ratio) of polycarbonate diol having a mass average molecular weight of 1,000. It mix | blends so that the equivalent ratio with an isocyanate group may be set to 1/1, Furthermore, 160 mass parts of toluene is added, and it stirs in nitrogen atmosphere, and it is 6 degreeC at 80 degreeC until an isocyanate group density | concentration reaches | attains theoretical amount. The reaction was continued for more than an hour.
Subsequently, a solution obtained by diluting 1.44 parts by mass (solid content ratio) of 2-hydroxyethyl methacrylate (2-HEMA) in 30 parts by mass of toluene is added, and further at 80 ° C. until the isocyanate groups at both ends disappear. The reaction was performed for 6 hours to obtain a urethane prepolymer (UY) having a mass average molecular weight of 29,000.
(2) Synthesis of acrylic urethane-based resin In a reaction vessel under nitrogen atmosphere, 100 parts by mass (solid content ratio) of urethane prepolymer obtained in (1) above and 117 parts by mass (solid content ratio) of methyl methacrylate (MMA) 2-hydroxyethyl methacrylate (2-HEMA) 5.1 parts by mass (solid content ratio), 1-thioglycerol 1.1 parts by mass (solid content ratio), and toluene 50 parts by mass, The temperature was raised to ° C.
Further, a solution obtained by further diluting 2.2 parts by mass (solid content ratio) of radical initiator (manufactured by Nippon Finechem Co., Ltd., product name “ABN-E”) with 210 parts by mass of toluene in a reaction vessel was heated to 105 ° C. It was dripped over 4 hours, maintaining.
After completion of the dropping, the reaction was carried out at 105 ° C. for 6 hours to obtain a solution of an acrylic urethane resin having a mass average molecular weight of 105,000.
(3) Preparation of composition (y-2) An isocyanate-based crosslinking agent as a crosslinking agent was added to 100 parts by mass (solid content ratio) of the acrylic urethane-based resin solution obtained in (2) above, which is a non-adhesive resin. (Product name “Coronate HL” manufactured by Tosoh Corporation) 6.3 parts by mass (solid content ratio), and 1.4 parts by mass (solid content ratio) of dioctyltin bis (2-ethylhexanoate) as a catalyst Were mixed, further diluted with toluene, and stirred uniformly to prepare a composition (y-2) having a solid content concentration (active ingredient concentration) of 30% by mass.

Production Example 4
(Adjustment of composition (y-3))
An acrylic copolymer having a structural unit derived from a raw material monomer consisting of an acrylic copolymer (n-butyl acrylate (BA) / acrylic acid (AAc) = 90/10 (mass ratio), which is an adhesive resin, (Mass average molecular weight: 460,000) was diluted with a mixed solvent of ethyl acetate and toluene to prepare a composition (y-3) having a solid content concentration (active ingredient concentration) of 30% by mass.

Details of the release film and the base film used in the following Examples and Comparative Examples are shown below.
Release film (1): manufactured by Lintec Corporation, product name “SP-PET 382150”, polyethylene terephthalate (PET) film provided with a release agent layer formed from a silicone release agent on one side, thickness: 38 μm.
Release film (2): manufactured by Lintec Co., Ltd., product name “SP-PET381031”, a PET film provided with a release agent layer formed from a silicone release agent on one side, thickness: 38 μm.
Base film (1): manufactured by Mitsubishi Plastics, product name “Diafoil K-700-6E”, biaxially oriented PET film, thickness: 6.0 μm.
Base film (2): manufactured by Mitsubishi Plastics, product name “Diafoil K100-2.0W”, biaxially stretched PET film, thickness: 2.0 μm.

Examples 1 to 3, Comparative Example 1
(1) Formation of coating film On the release agent layer of the release film (1) as the first release material, the composition (x-1) prepared in Production Example 1, the type of composition described in Table 1, and The composition (x-1) prepared in Production Example 1 was simultaneously applied in this order using a multilayer die coater (width: 250 mm) at a coating speed of 30 m / min. (Y ′) and the coating film (x2 ′) were simultaneously formed in this order.
In addition, the application quantity of the composition for forming a coating film (x1 '), a coating film (y'), and a coating film (x2 ') is as having described in Table 1.
(2) Drying treatment The formed coating film (x1 ′), coating film (y ′), and coating film (x2 ′) are simultaneously dried at a drying temperature of 125 ° C. for 60 seconds to form a release agent layer of the release film (1). In this order, a stacked body in which the layer (X1), the layer (Y), and the layer (X2) were directly stacked was formed.
And the release agent layer of the peeling film (2) which is a 2nd peeling material was laminated | stacked on the surface of the layer (X2) which has exposed, and the double-sided adhesive sheet was obtained.

Example 4
(1) Formation of coating film A coating film (x1) made of the composition (x-1) prepared in Production Example 1 using an applicator on the release agent layer of the release film (1) as the first release material ') And a coating film (y') comprising the composition (y-2) prepared in Production Example 3 on the coating film (x1 '), and Production Example 1 on the coating film (y'). The prepared composition (x-1) was sequentially formed.
(2) Drying treatment The formed coating film (x1 ′), coating film (y ′), and coating film (x2 ′) are simultaneously dried at a drying temperature of 110 ° C. for 120 seconds to form a release agent layer of the release film (1). In this order, a stacked body in which the layer (X1), the layer (Y), and the layer (X2) were directly stacked was formed. In addition, the thickness of the formed layer (X1), layer (Y), and layer (X2) was as shown in Table 1.
And the release agent layer of the peeling film (2) which is a 2nd peeling material was laminated | stacked on the surface of the layer (X2) which has exposed, and the double-sided adhesive sheet was obtained.

Comparative Example 2
On the release agent layer of the release film (1) as the first release material, a coating film (x1 ′) made of the composition (x-1) prepared in Production Example 1 is formed and dried at 110 ° C. for 120 seconds. Only the layer (X1) was formed. In addition, the thickness of the formed layer (X1) was as shown in Table 1.
And the release agent layer of the peeling film (2) which is a 2nd peeling material was laminated | stacked on the surface of the layer (X1) exposed, and the double-sided adhesive sheet was obtained.

Comparative Examples 3-4
On the release agent layer of the release film (1) as the first release material, a coating film (x1 ′) made of the composition (x-1) prepared in Production Example 1 is formed and dried at 110 ° C. for 120 seconds. Layer (X1) was formed.
Separately, a coating film (x2 ′) composed of the composition (x-1) prepared in Production Example 1 was formed on the release agent layer of the release film (2), which is the second release material, at 110 ° C. It was dried for 120 seconds to form a layer (X2).
In addition, the thickness of the formed layer (X1) and layer (X2) was as shown in Table 1.
Then, on the surface of the exposed layer (X1), as the layer (Y), the base film (1) is laminated in Comparative Example 3, the base film (2) is laminated in Comparative Example 4, and the base material is further laminated. A layer (X2) was laminated on the film to form a laminate, and a double-sided PSA sheet was obtained in which the laminate was sandwiched between two release materials.

Comparative Examples 5-6
On the release agent layer of the release film (1) as the first release material, a coating film (x1 ′) made of the composition (x-1) prepared in Production Example 1 is formed and dried at 110 ° C. for 120 seconds. Layer (X1) was formed.
Separately, a coating film (x2 ′) composed of the composition (x-1) prepared in Production Example 1 was formed on the release agent layer of the release film (2), which is the second release material, at 110 ° C. It was dried for 120 seconds to form a layer (X2).
Furthermore, on the release agent layer of the release film (2) prepared separately, (y-1) prepared in Production Example 2 was used in Comparative Example 5, and (y-2) prepared in Production Example 3 was used in Comparative Example 6. A coating film was formed and dried at 110 ° C. for 120 seconds to form a layer (Y).
In addition, the thickness of the formed layer (X1), layer (Y), and layer (X2) was as shown in Table 1.
Then, on the surface of the exposed layer (X1), the layer (Y) is laminated, and the release film (2) on the layer (Y) is further removed, and on the surface of the exposed layer (Y). The layer (X2) was laminated to form a laminate, and a double-sided PSA sheet was obtained in which the laminate was sandwiched between two release materials.

The thickness of the laminate (the thickness of the layer (X1) in Comparative Example 2) that the double-sided PSA sheets prepared in Examples and Comparative Examples have, and the layer (X1), the layer (Y) constituting the laminate, And the thickness of layer (X2) was measured based on the above-mentioned method. The measurement results are shown in Table 1.

About the layer (Y) and laminated body which the double-sided adhesive sheet produced by the Example and the comparative example has, various physical properties were measured based on the method below. These results are shown in Table 2.
In addition, since the double-sided adhesive sheet produced in the comparative example 2 does not have a layer (Y), the following various physical properties are not measured.

<Rupture strength and elongation at break of layer (Y)>
On the release agent layer of the release film (1), only the layer (Y) of the double-sided pressure-sensitive adhesive sheet prepared under the same conditions as in each Example and Comparative Example was formed, and then the release film (1) was removed, A sample cut into 150 mm × 15 mm was used as a test sample.
Then, using a universal material testing machine (manufactured by A & D Co., Ltd., product name “Tensilon RTG-1225”), the breaking strength in the MD direction of the test sample at a chuck distance of 100 mm and a tensile speed of 200 mm / min. And the breaking elongation was measured.
The “MD direction” refers to the direction in which the composition was applied when forming the coating film in Examples 1 to 4 and Comparative Examples 5 and 6, and in Comparative Examples 3 and 4, the base used. It refers to the flow direction of the film forming machine when manufacturing the material film.

<Haze of laminate, total light transmittance>
The double-sided PSA sheets obtained in Examples and Comparative Examples were each cut into 5 cm squares, the first release material was removed, and the surface of the exposed laminate (the surface of the layer (X1) in Comparative Example 2) was made of glass. A test piece was prepared by pasting on the surface of a plate (manufactured by Nippon Sheet Glass Co., Ltd., soda lime glass plate) and then removing the second release material.
About haze of a laminated body, the haze of 3 points | pieces arbitrarily selected of the test piece was measured based on JISK7136: 2000 using the haze meter (the Nippon Denshoku Industries Co., Ltd. make, product name "NDH2000"). And the average value was made into the haze of the target laminated body.
Further, the total light transmittance of the laminate was determined by measuring the total light transmittance at three arbitrarily selected points of the test piece in accordance with JIS K7361-1: 1997 using the haze meter, and calculating the average The value was defined as the total light transmittance of the target laminate.

About the double-sided adhesive sheet produced by the Example and the comparative example, the following tests were done and the property of each double-sided adhesive sheet was evaluated. The evaluation results are shown in Table 2.
In addition, since the double-sided adhesive sheet produced by the comparative example 2 does not have a layer (Y), the interface adhesiveness test is not performed.

<Adhesive strength>
The 2nd release material of the double-sided adhesive sheet produced by the Example and the comparative example was removed, and the PET film (Mitsubishi Resin Co., Ltd. product) on the surface of the exposed laminated body (in the comparative example 2 on the surface of a layer (X1)). The product name “Diafoil T-100”, thickness 50 μm) was bonded and cut into a size of 300 mm long × 25 mm wide.
Then, the first release material is also removed, and the stainless steel plate (on the surface of the layer (X1) in Comparative Example 2) is exposed to a stainless steel plate (23 ° C., 50% RH (relative humidity)). SUS304, No. 360) was affixed and allowed to stand for 24 hours in the same environment.
After standing, the adhesive strength of the double-sided pressure-sensitive adhesive sheet was measured at a pulling speed of 300 mm / min by a 180 ° peeling method based on JIS Z0237: 2000.

<Crying breakup test>
After the double-sided pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples are cut into a size of 300 mm long × 25 mm wide, the second release material side is fixed, and the first release material is at an angle of 90 ° with respect to the double-sided pressure-sensitive adhesive sheet. It was confirmed whether or not a tearing phenomenon occurred in which the laminate or the pressure-sensitive adhesive layer was divided and peeled off with the two release materials. This operation was repeated 20 times, and the effect of suppressing the crying phenomenon was evaluated based on the number of times the crying phenomenon occurred.
A: In all of the 20 times confirmed, no crying phenomenon occurred.
B: During the confirmed 20 times, a crying phenomenon occurred once.
C: The tearing phenomenon occurred twice or more during the confirmed 20 times.

<Interface adhesion test>
The second release material was removed from the double-sided PSA sheets prepared in Examples and Comparative Examples, and a PET film (product name “Diafoil T-100”, manufactured by Mitsubishi Plastics, Inc. 50 μm) were bonded together and cut into a size of 300 mm long × 25 mm wide.
Then, the first release material was also removed, and a stainless steel plate (SUS306, No. 600 polishing) was applied to the surface of the exposed laminate. After standing for 7 days in an environment of 70 ° C. and dry, further 23 ° C. , And left in an environment of 50% RH (relative humidity) for 1 day.
After standing, the state of the peeling interface when the PET film was peeled was observed, and the interfacial adhesion between the layer (Y) and the layers (X1) and (X2) was evaluated according to the following criteria.
A: No peeling was confirmed at any of the interface between the layer (X1) and the layer (Y) and at the interface between the layer (X2) and the layer (Y), and the layer (X2) and the PET film It was peeled between.
B: Slight peeling was confirmed at the interface between the layer (X1) and the layer (Y) and at least one of the interfaces between the layer (X2) and the layer (Y). , Peeled between layer (X2) and PET film.
C: Peeling was partially confirmed at the interface between the layer (X1) and the layer (Y) and at least one of the interfaces between the layer (X2) and the layer (Y). Y) was peeled between layer (X1) or layer (X2).
D: Most of the peeling was confirmed at the interface between the layer (X1) and the layer (Y) and at least one of the interfaces between the layer (X2) and the layer (Y). It peeled between the layer (X1) or the layer (X2).

From Table 2, the double-sided pressure-sensitive adhesive sheets of Examples 1 to 4 had good adhesive strength and resulted in a high effect of suppressing the tearing phenomenon. Moreover, these double-sided PSA sheets are considered to be excellent in punching processability, pasting suitability and cutting processability because of high interfacial adhesion between the base material layer and the PSA layer.
On the other hand, the double-sided pressure-sensitive adhesive sheets of Comparative Examples 1 and 2 did not have a base material layer composed of a non-adhesive resin, so that tearing was likely to occur.
In addition, although the double-sided PSA sheets of Comparative Examples 3 to 6 have a high effect of suppressing the tearing-off phenomenon, the interfacial adhesion between the base material layer and the PSA layer is low, and there are problems in the punching processability, sticking suitability, and cutting processability. It is believed that there is.

The double-sided pressure-sensitive adhesive sheet of one embodiment of the present invention is useful as a double-sided pressure-sensitive adhesive sheet having a large affixing area used for identification or decoration, coating masking, surface protection of metal plates and the like.

1, 2, 3, 4 Double-sided adhesive sheet 10 Laminate 11 Base material layer (Y)
121 1st adhesive layer (X1)
122 2nd adhesive layer (X2)
123 3rd adhesive layer (X3)
124 4th adhesive layer (X4)
131, 132 Release material

Claims

A double-sided pressure-sensitive adhesive sheet having a laminate in which the first pressure-sensitive adhesive layer (X1), the base material layer (Y), and the second pressure-sensitive adhesive layer (X2) are directly laminated in this order,
The laminate is
A coating film (x1 ′) comprising a composition (x1) containing an adhesive resin, which is a material for forming the first adhesive layer;
A coating film (y ′) made of a composition (y) containing a non-adhesive resin selected from the group consisting of an acrylic urethane-based resin and an olefin-based resin, which is a forming material of the base material layer (Y);
A coating film (x2 ′) comprising a composition (x2) containing an adhesive resin, which is a material for forming the second adhesive layer;
Are laminated | stacked directly in this order, Then, the double-sided adhesive sheet formed by drying simultaneously a coating film (x1 '), (y'), and (x2 ').
The double-sided pressure-sensitive adhesive according to claim 1, wherein the thickness ratio of the base material layer (Y) to the total thickness 100 of the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2) is 1 to 100. Sheet.
The double-sided pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the laminate has a thickness of 2 to 90 µm.
The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the base material layer (Y) has a thickness of 0.3 to 50.0 µm.
The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the adhesive resin contained in the compositions (x1) and (x2) contains an acrylic resin.
The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the non-sticky resin contained in the composition (y) is an ultraviolet non-curable resin having no polymerizable functional group.
The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the base material layer (Y) is an unstretched sheet-like material.
The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 7, wherein the elongation at break of the base material layer (Y) is 100% or more.
The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 8, wherein the base material layer (Y) has a breaking strength of 30 MPa or more.
The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 9, wherein the laminate has a haze of 5.00% or less.
The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 10, wherein the total light transmittance of the laminate is 80% or more.
A method for producing a double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 11,
A method for producing a double-sided pressure-sensitive adhesive sheet, comprising the following steps (1) to (2).
Step (1): a coating film (x1 ′) composed of the composition (x1), a coating film (y ′) composed of the composition (y), and a coating film (x2 ′) composed of the composition (x2) A process of directly stacking layers in this order.
-Process (2): The process of drying a coating film (x1 '), a coating film (y'), and a coating film (x2 ') simultaneously, and forming the said laminated body.
The manufacturing method of the double-sided adhesive sheet of Claim 12 which apply | coats a composition (x1), a composition (y), and a composition (x2) simultaneously in a process (1).
The method for producing a double-sided pressure-sensitive adhesive sheet according to claim 12 or 13, wherein the composition (x1), the composition (y), and the composition (x2) further contain a diluent solvent.