JP2018048317A - Adhesive sheet laminate, size enlarged adhesive sheet laminate and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel adhesive sheet laminate having an adhesive layer, and a coating part by detachably being laminated on one surface of the adhesive layer, and capable of forming an uneven shape corresponding to an uneven shape of an adherend surface at high accuracy, and a size enlarged adhesive sheet laminate using the adhesive sheet laminate.SOLUTION: There is proposed an adhesive sheet laminate having an adhesive layer and a coated part by being detachably laminated on one surface of the adhesive layer, storage elastic modulus E'(MA) of the coated part I at 100°C of 1.0×10to 2.0×10Pa and storage elastic modulus E'(MB) of the coated part I at 30°C of 5.0×10to 1.0×10Pa.SELECTED DRAWING: Figure 1

Description

  The present invention can be suitably used for forming an image display device such as a personal computer, a mobile terminal (PDA), a game machine, a television (TV), a car navigation system, a touch panel, and a pen tablet. The present invention relates to a pressure-sensitive adhesive sheet laminate and a pressure-sensitive adhesive sheet laminate suitable for forming a shaped pressure-sensitive adhesive sheet laminate.

A touch panel image display device is usually configured by combining a surface protection panel, a touch panel, and an image display panel (collectively, also referred to as “component for image display device”).
In recent years, surface protection panels for touch panel image display devices such as smartphones and tablet terminals have been made of tempered glass and plastic materials such as acrylic resin plates and polycarbonate plates. The part is printed in black.
In the touch panel, a plastic film sensor is used together with the glass sensor, a touch-on lens (TOL) member in which the touch panel function is integrated with the surface protection panel, or the touch panel function is integrated in the image display panel. Members such as on-cell and in-cell are used.

In this type of image display device, in order to further improve the image visibility, the gaps between the constituent members for each image display device are made of a transparent resin such as a liquid adhesive, a thermoplastic adhesive sheet material, and an adhesive sheet material. The structure to fill is common.
By the way, in the field of image display devices centering on mobile phones and mobile terminals, in addition to thinning and high precision, design diversification has progressed, and the peripheral edge of the surface protection panel has a black frame shape. In the past, it has been common to print the concealing portion, but with the diversification of design, the frame-shaped concealing portion has begun to be formed in a color other than black. When the concealing part is formed with a color other than black, the concealing property is low, and therefore the height of the concealing part, that is, the printing part tends to be higher than that of black. Therefore, it is required that the pressure-sensitive adhesive sheet for laminating components having such a printing unit be filled to every corner following a large printing step.
Therefore, various methods for filling the printing step have been proposed.

  For example, Patent Document 1 discloses a new image display device that can be bonded to a surface to be adhered in a close contact state even if the surface to be bonded to which the pressure-sensitive adhesive sheet is bonded has a step due to printing or the like. A double-sided pressure-sensitive adhesive sheet for bonding any two adherends selected from the constituent members for image display devices of a surface protection panel, a touch panel and an image display panel as a double-sided pressure-sensitive adhesive sheet, The body has a stepped portion on the adherend surface to which the double-sided pressure-sensitive adhesive sheet is adhered, and the double-sided pressure-sensitive adhesive sheet has a shape of a bonding surface to be bonded to the adherend surface along the surface shape of the adhesion surface. A double-sided pressure-sensitive adhesive sheet for an image display device, which is shaped, is disclosed.

  Moreover, in patent document 2, about the manufacturing method of the double-sided adhesive sheet for bonding any two adherends selected from a surface protection panel, a touch panel, and an image display panel, the double-sided adhesive sheet before bonding is A double-sided pressure-sensitive adhesive sheet for an image display device, wherein the pressure-sensitive adhesive composition having a gel fraction of less than 40% is formed into the same surface shape as the uneven shape of the bonding surface of the adherend. A manufacturing method is disclosed.

WO2014 / 073316 A1 WO2015 / 174392 A1

  In recent years, in the field of image display devices centering on mobile phones and mobile terminals, there has been a further demand for thinning and high precision, and adhesive sheets for bonding image display device components also have printing steps and the like. It is required that the uneven portion on the surface of the adherend can be filled with high accuracy and that the adhesive material does not protrude outside. As a countermeasure for this, it has been studied that the surface shape of the pressure-sensitive adhesive sheet is formed in advance along the surface shape of the adherend as disclosed in the above-mentioned prior patent documents.

And in order to form the surface shape of the pressure-sensitive adhesive sheet along the surface shape of the adherend in advance, a pressure-sensitive adhesive sheet laminate in which release sheets are laminated on both sides of the pressure-sensitive adhesive sheet is press-molded. Thus, a method of forming a concavo-convex shape coinciding with the concavo-convex portion on the adherend surface is assumed.
However, as a result of actually carrying out the method using a pressure-sensitive adhesive sheet laminate formed by laminating a normal release sheet on both sides of the pressure-sensitive adhesive sheet, a concavo-convex shape coinciding with the concavo-convex portion on the adherend surface is obtained. The problem that it is difficult to form on the surface of an adhesive sheet with high accuracy has been clarified.

  Therefore, the present invention relates to a pressure-sensitive adhesive sheet laminate comprising a pressure-sensitive adhesive layer and a covering portion that is detachably laminated on one side of the pressure-sensitive adhesive layer, and has an uneven shape that matches the unevenness on the adherend surface. A new pressure-sensitive adhesive sheet laminate that can be formed on the surface of the pressure-sensitive adhesive layer and a shaped pressure-sensitive adhesive sheet laminate using the pressure-sensitive adhesive sheet laminate are proposed.

The present invention relates to a pressure-sensitive adhesive sheet laminate comprising a pressure-sensitive adhesive layer and a covering portion I that is peelably laminated on one surface of the pressure-sensitive adhesive layer, and a storage elastic modulus E ′ of the covering portion I at 100 ° C. MA) is 1.0 × 10 ^{6 to} 2.0 × 10 ⁹ Pa, and the storage elastic modulus E ′ (MB) at 30 ° C. of the covering portion I is 5.0 × 10 ^{7 to} 1.0 ×. A pressure-sensitive adhesive sheet laminate having a pressure of 10 ¹⁰ Pa is proposed.

  The present invention is also a shaped pressure-sensitive adhesive sheet laminate using the pressure-sensitive adhesive sheet laminate, wherein the pressure-sensitive adhesive layer has a concave portion, a convex portion, or a concave-convex portion (referred to as “pressure-sensitive adhesive layer surface concave-convex portion”) on one surface of the front and back sides. ), And the covering portion I is in close contact with the front and back side surfaces of the pressure-sensitive adhesive layer, and is provided with a concave portion, a convex portion, or an uneven portion (referred to as a “cover portion surface uneven portion”) on the front and back side surface. In addition, a convex portion or a concave portion or a convex concave portion (referred to as a “covered portion back surface convex concave portion”) having irregularities that coincide with the concave and convex portions on the surface of the adhesive material layer on the front and back other side surfaces opposite to the one side of the front and back sides. Proposed is a shaped adhesive sheet laminate.

  According to the pressure-sensitive adhesive sheet laminate proposed by the present invention, for example, after the pressure-sensitive adhesive sheet laminate is heated, a mold is pressed against the covering portion I to form a concave-convex shape that matches the concave-convex portion on the adherend surface. Can be formed on the surface of the adhesive layer with high accuracy. In addition, since the covering portion I can maintain shape retention in a normal state, it is easy to handle and is not too hard, so that it is possible to suppress unnecessary unintentional unevenness on the adhesive layer. it can.

  The shaped pressure-sensitive adhesive sheet laminate proposed by the present invention comprises a pressure-sensitive adhesive sheet surface uneven portion on the front and back side surfaces of the pressure-sensitive adhesive layer, and the covering portion I is in close contact with the front and back side surfaces of the pressure-sensitive adhesive layer. The front and back one side surface is provided with a covering portion surface uneven portion, and the front and back other side surface opposite to the front and back one side is provided with a covering portion back surface convex concave portion. Thus, in the shaped pressure-sensitive adhesive sheet laminate proposed by the present invention, the covering portion I is in close contact with the front and back side surfaces of the pressure-sensitive adhesive layer, and is peeled to the front and back side surfaces of the pressure-sensitive adhesive layer. Since the covering portion I is configured to be laminated, it is possible to prevent dust and the like from adhering to the surface of the pressure-sensitive adhesive layer to reduce the adhesive force, and the pressure-sensitive adhesive layer. The shape of the uneven surface of the adhesive material layer formed on the front and back surfaces of the surface prevents moisture from absorbing moisture and collapsing, and dust adheres to the surface and reduces adhesive strength. You can also.

It is sectional drawing which showed typically an example of the adhesive sheet laminated body which is an Example of this invention. It is sectional drawing for demonstrating an example of the press process at the time of manufacturing a shaped adhesive sheet laminated body using an example of the adhesive sheet laminated body which is an Example of this invention. It is the figure which showed typically an example of the shaped adhesive sheet laminated body which is an Example of this invention, (A) is sectional drawing, (B) is a perspective view. It is the figure which showed the viscoelastic curve of the material used for the adhesive sheet laminated body produced by the Example and the comparative example. It is the perspective view which showed one side of the metal mold | die used by the Example and the comparative example.

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

[This adhesive sheet laminate]
As shown in FIG. 1, the pressure-sensitive adhesive sheet laminate (referred to as “the present pressure-sensitive adhesive sheet laminate”) according to an example of the embodiment of the present invention can be peeled from the pressure-sensitive adhesive layer and one side of the pressure-sensitive adhesive layer. It is a pressure-sensitive adhesive sheet laminate comprising a laminated covering portion I and a covering portion II that is releasably laminated on the other side of the pressure-sensitive adhesive layer. Here, the covering portion II is arbitrary, and the covering portion II may not be stacked.

<Adhesive layer>
The pressure-sensitive adhesive layer of this pressure-sensitive adhesive sheet laminate can function as a double-sided pressure-sensitive adhesive sheet when the covering portion I and the covering portion II are peeled off, and has a hot melt property that softens or melts when heated. That's fine.

The pressure-sensitive adhesive layer preferably has a loss tangent tan δ (SA) at 100 ° C. of 1.0 or more. Further, the loss tangent tan δ (SB) at 30 ° C. is preferably less than 1.0.
Here, the loss tangent tan δ means the ratio (G ″ / G ′) between the loss elastic modulus G ″ and the storage elastic modulus G ′.
Since the temperature at the time of heat-molding this pressure-sensitive adhesive sheet laminate is usually 70 to 120 ° C., if the loss tangent tan δ (SA) at 100 ° C. is 1.0 or more, an uneven shape is molded on the surface of the pressure-sensitive adhesive layer. It becomes easy.
Further, if the loss tangent tan δ (SB) at 30 ° C. of the pressure-sensitive adhesive layer is less than 1.0, the shape can be maintained in a normal state, so that the uneven shape matching the uneven portion on the adherend surface can be accurately obtained. The state formed on the surface of the adhesive layer can be maintained.
In general, a polymer material has both a viscous property and an elastic property, and the loss tangent tan δ is 1.0 or more, and the viscosity value becomes stronger as the value increases. On the other hand, the elastic property becomes stronger as the loss tangent tan δ is less than 1.0 and the value is further reduced. For this reason, by controlling the loss tangent tan δ at different temperatures of the adhesive layer, it becomes possible to have both formability and shape retention.

From this viewpoint, the loss tangent tan δ (SA) at 100 ° C. of the pressure-sensitive adhesive layer is preferably 1.0 or more, more preferably 1.5 or more and 30 or less, and particularly preferably 3.0 or more and 20 or less. preferable.
On the other hand, the loss tangent tan δ (SB) at 30 ° C. of the pressure-sensitive adhesive layer is preferably less than 1.0, particularly 0.01 or more and 0.9 or less, and more preferably 0.1 or more and 0.8 or less. Is preferred.

  Here, the loss tangent tan δ (SA) at 100 ° C. and the loss tangent tan δ (SB) at 30 ° C. of the adhesive layer adjust the components, gel fraction, weight average molecular weight, etc. of the composition constituting the adhesive layer. Can be adjusted to the above range.

Furthermore, it is preferable that the storage elastic modulus G ′ (SA) at 100 ° C. of the pressure-sensitive adhesive layer is less than 1.0 × 10 ⁴ Pa. Moreover, it is preferable that the storage elastic modulus G '(SB) in 30 degreeC of the said adhesive material layer is 1.0 * 10 < ⁴ > Pa or more.
If the storage elastic modulus G ′ (SA) at 100 ° C. of the pressure-sensitive adhesive layer is less than 1.0 × 10 ⁴ Pa, it is preferable because sufficient moldability can be obtained. On the other hand, the storage elastic modulus at 30 ° C. of the pressure-sensitive adhesive layer. If G ′ (SB) is 1.0 × 10 ⁴ Pa or more, it is preferable from the viewpoint of shape stability after molding.

From this point of view, the storage elastic modulus G ′ (SA) at 100 ° C. of the adhesive layer is preferably less than 1.0 × 10 ⁴ Pa, among which 5.0 × 10 ¹ Pa or more or 5.0 × 10 ^3. It is more preferable that it is Pa or less, and among these, 1.0 × 10 ² Pa or more or 1.0 × 10 ³ Pa or less is more preferable.
From this viewpoint, the storage elastic modulus G ′ (SB) at 30 ° C. of the pressure-sensitive adhesive layer is preferably 1.0 × 10 ⁴ Pa or more, and more preferably 2.0 × 10 ⁴ Pa or more or 1.0 ×. 10 ⁷ Pa or less is more preferable, and among them, 5.0 × 10 ⁴ Pa or more or 1.0 × 10 ⁶ Pa or less is more preferable.

  Here, the storage elastic modulus G ′ (SA) at 100 ° C. of the pressure-sensitive adhesive layer and the storage elastic modulus G ′ (SB) at 30 ° C. of the pressure-sensitive adhesive layer are components and gel fractions of the composition constituting the pressure-sensitive adhesive layer. By adjusting the weight average molecular weight or the like, the above range can be adjusted.

The temperature at which the loss tangent tan δ of the pressure-sensitive adhesive layer is 1.0 is preferably 50 to 150 ° C., more preferably 60 ° C. or more and 130 ° C. or less, and particularly preferably 70 ° C. or more or 110 ° C. or less. .
If the temperature at which the loss tangent tan δ of the pressure-sensitive adhesive layer is 1.0 is 50 to 150 ° C., the pressure-sensitive adhesive sheet laminate can be molded by heating to 50 to 150 ° C.

The glass transition temperature (Tg) of the base resin of the adhesive layer is preferably −50 to 40 ° C., more preferably −30 ° C. or more or 25 ° C. or less, and particularly preferably −10 ° C. or more or 20 ° C. or less. Further preferred. Here, the measurement of the glass transition temperature refers to the midpoint between the inflection points of the baseline shift when the temperature is increased at a rate of 3 ° C./min using a differential scanning calorimeter (DSC).
If the glass transition temperature (Tg) of the base resin of the pressure-sensitive adhesive layer is within the above range, the pressure-sensitive adhesive layer can be given adhesiveness, and the temperature at which the loss tangent tan δ of the pressure-sensitive adhesive layer becomes 1.0 is set. It is possible to adjust to 50 to 150 ° C.

As the material of the adhesive layer, a conventionally known adhesive sheet can be used as long as it can be adjusted to a predetermined viscoelastic behavior.
For example, 1) a (meth) acrylic acid ester-based polymer (including a copolymer, hereinafter referred to as “acrylic ester-based (co) polymer”) is used as a base resin, and a crosslinking monomer is necessary for this. Depending on the pressure-sensitive adhesive sheet formed by blending a crosslinking initiator or a reaction catalyst,
2) A pressure-sensitive adhesive sheet formed by using a butadiene or isoprene-based copolymer as a base resin, blending a crosslinking monomer, a crosslinking initiator or a reaction catalyst as necessary, and causing a crosslinking reaction;
3) A pressure-sensitive adhesive sheet formed by crosslinking reaction by using a silicone polymer as a base resin, blending a crosslinking monomer, a crosslinking initiator or a reaction catalyst if necessary, and the like,
4) A polyurethane-based pressure-sensitive adhesive sheet using a polyurethane-based polymer as a base resin can be used.

The physical properties of the adhesive layer itself are not an essential problem in the present invention, except for the viscoelastic properties and thermal properties described above. However, from the viewpoints of tackiness, transparency, weather resistance, and the like, those using the acrylate ester (co) polymer of 1) as a base resin are preferable.
When performance such as electrical characteristics and low refractive index is required, those based on the butadiene or isoprene-based copolymer of 2) above are preferable.
When performances such as heat resistance and rubber elasticity in a wide temperature range are required, those using the silicone copolymer of 3) as a base resin are preferable.
When performance such as removability is required, those using the polyurethane polymer of 4) as a base resin are preferable.

As an example of the adhesive material layer, it was formed from a resin composition containing a (meth) acrylic copolymer (a) as a base resin, a crosslinking agent (b), and a photopolymerization initiator (c). An adhesive sheet can be illustrated.
In this case, it is necessary to satisfy the viscoelastic characteristics in an uncrosslinked state, that is, before a three-dimensionally crosslinked network structure is formed. From this viewpoint, it is preferable that the gel fraction of the adhesive layer is 40% or less.

If the gel fraction of the pressure-sensitive adhesive layer is 40% or less, the bonding between the molecular chains constituting the pressure-sensitive adhesive layer is suppressed to an appropriate range, so that it has an appropriate fluidity when molded into a shaped pressure-sensitive adhesive sheet laminate. Can be provided.
From this viewpoint, the gel fraction of the pressure-sensitive adhesive layer is preferably 40% or less, more preferably 20% or less, and particularly preferably 10% or less. In addition, the minimum of the gel fraction of an adhesive material layer is not limited, 0% may be sufficient.
In addition, the gel fraction of said adhesive material layer is a resin composition containing (meth) acrylic-type copolymer (a), a crosslinking agent (b), and a photoinitiator (c) as base resin. The same applies to the case where other resin composition is used as the adhesive layer.

((Meth) acrylic copolymer (a))
The (meth) acrylic copolymer (a) has properties such as a glass transition temperature (Tg) as appropriate depending on the types and composition ratios of the acrylic and methacrylic monomers used for polymerizing the (meth) acrylic copolymer (a). It is possible to adjust.

  Examples of the acrylic monomer and methacrylic monomer used for polymerizing the acrylate polymer include 2-ethylhexyl acrylate, n-octyl acrylate, n-butyl acrylate, ethyl acrylate, methyl methacrylate, and the like. Vinyl acetate, hydroxyethyl acrylate, acrylic acid, glycidyl acrylate, acrylamide, acrylonitrile, methacrylonitrile, fluorine acrylate, silicone acrylate, etc., which are copolymerized with a hydrophilic group or an organic functional group, can also be used.

Among the acrylic ester polymers, (meth) acrylic acid alkyl ester copolymers are particularly preferable.
The (meth) acrylate used for forming the (meth) acrylic acid alkyl ester copolymer, that is, as the alkyl acrylate or alkyl methacrylate component, the alkyl group is n-octyl, isooctyl, 2-ethylhexyl, n-butyl, One of alkyl acrylate or alkyl methacrylate which is any one of isobutyl, methyl, ethyl and isopropyl, or a mixture of two or more selected from these is preferable.

As other components, an acrylate or methacrylate having an organic functional group such as a carboxyl group, a hydroxyl group, or a glycidyl group may be copolymerized. Specifically, a monomer component obtained by appropriately and selectively combining the alkyl (meth) acrylate component and the (meth) acrylate component having an organic functional group as a starting material is subjected to heat polymerization to form a (meth) acrylate ester copolymer. A polymer polymer can be obtained.
Among them, preferably, an alkyl acrylate such as iso-octyl acrylate, n-octyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, or a mixture of two or more selected from these, or iso-octyl acrylate, Examples thereof include those obtained by copolymerizing at least one kind of n-octyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and the like with acrylic acid.

  As the polymerization treatment using these monomers, known polymerization methods such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization and the like can be employed. In this case, a thermal polymerization initiator or photopolymerization is used according to the polymerization method. An acrylic ester copolymer can be obtained by using a polymerization initiator such as an initiator.

(Acrylic copolymer (A1))
As an example of a preferable base polymer of the adhesive material layer, there can be mentioned a (meth) acrylic copolymer (A1) composed of a graft copolymer having a macromonomer as a branch component.

If the pressure-sensitive adhesive layer is composed of the acrylic copolymer (A1) as a base resin, the pressure-sensitive adhesive layer can exhibit self-adhesion while maintaining a sheet shape at room temperature, and when heated in an uncrosslinked state It has a hot melt property that melts or flows, and can be photocured, and after photocuring, it exhibits excellent cohesive force and can be bonded.
Therefore, if the acrylic copolymer (A1) is used as the base polymer of the adhesive material layer, even in an uncrosslinked state, it exhibits adhesiveness at room temperature (20 ° C.) and is more preferably 50 to 100 ° C. Can be softened or fluidized when heated to a temperature of 60 ° C. or higher or 90 ° C. or lower.

The glass transition temperature of the copolymer constituting the trunk component of the acrylic copolymer (A1) is preferably −70 to 0 ° C.
At this time, the glass transition temperature of the copolymer component constituting the trunk component refers to the glass transition temperature of a polymer obtained by copolymerizing only the monomer component composing the trunk component of the acrylic copolymer (A1). . Specifically, it means a value calculated by the Fox formula from the glass transition temperature and the composition ratio of the polymer obtained from the homopolymer of each component of the copolymer.
In addition, the calculation formula of Fox is a calculation value calculated | required by the following formula | equation, Polymer handbook [Polymer HandBook, J.M. Brandrup, Interscience, 1989].
1 / (273 + Tg) = Σ (Wi / (273 + Tgi))
[Wherein Wi represents the weight fraction of monomer i, and Tgi represents Tg (° C.) of the homopolymer of monomer i. ]

The glass transition temperature of the copolymer component constituting the backbone component of the acrylic copolymer (A1) is the flexibility of the adhesive layer at room temperature, the wettability of the adhesive layer to the adherend, In order to affect the adhesiveness, the glass transition temperature is preferably −70 ° C. to 0 ° C., particularly −65 ° C. in order for the pressure-sensitive adhesive layer to obtain appropriate adhesiveness (tackiness) at room temperature. Above, or −5 ° C. or less, and particularly preferably −60 ° C. or more or −10 ° C. or less.
However, even if the glass transition temperature of the copolymer component is the same temperature, the viscoelasticity can be adjusted by adjusting the molecular weight. For example, it can be made more flexible by reducing the molecular weight of the copolymer component.

Examples of the (meth) acrylic acid ester monomer contained in the main component of the acrylic copolymer (A1) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl ( (Meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meth) acrylate, isononyl (meta Acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl ( (Meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, 3,5,5-trimethylcyclohexane acrylate, p-cumylphenol EO-modified (meth) acrylate, dicyclopenta Nyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, benzyl (meth) acrylate, etc. . These include hydroxyl-containing (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and glycerol (meth) acrylate having a hydrophilic group or an organic functional group, ) Acrylic acid, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxypropylphthalate Acid, 2- (meth) acryloyloxyethylmaleic acid, 2- (meth) acryloyloxypropylmaleic acid, 2- (meth) acryloyloxyethylsuccinic acid, 2- (meth) acryloyloxypropylsuccinic acid, crotonic acid, fumaric acid Carboxyl group-containing monomers such as maleic acid, itaconic acid, monomethyl maleate and monomethyl itaconic acid, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride, glycidyl (meth) acrylate, glycidyl α-ethyl acrylate , Epoxy group-containing monomers such as (meth) acrylic acid 3,4-epoxybutyl, amino group-containing (meth) acrylic acid ester monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate, (meth) Acrylamide, Nt-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, diacetone acrylamide, maleic acid amide, maleimide, etc. Monomers containing amide group, vinyl pyrrolidone, vinyl pyridine, can also be used heterocyclic basic monomers such as vinyl carbazole.
Also, styrene, t-butylstyrene, α-methylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, alkyl vinyl ether, hydroxyalkyl vinyl ether, alkyl, which can be copolymerized with the acrylic monomer or methacrylic monomer. Various vinyl monomers such as vinyl monomers can also be used as appropriate.

Moreover, it is preferable that the trunk component of the acrylic copolymer (A1) contains a hydrophobic (meth) acrylate monomer and a hydrophilic (meth) acrylate monomer as constituent units.
If the trunk component of the acrylic copolymer (A1) is composed only of a hydrophobic monomer, a tendency to wet-heat whitening is recognized. Therefore, it is preferable to introduce a hydrophilic monomer into the trunk component to prevent wet-heat whitening. .

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

Here, examples of the hydrophobic (meth) acrylate monomer include n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) ) Acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meta) ) Acrylate, isononyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate , Lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxyethyl Examples thereof include (meth) acrylate and methyl methacrylate.
Examples of the hydrophobic vinyl monomer include vinyl acetate, styrene, t-butyl styrene, α-methyl styrene, vinyl toluene, and alkyl vinyl monomers.

  Examples of the hydrophilic (meth) acrylate monomer include methyl acrylate, (meth) acrylic acid, tetrahydrofurfuryl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) ) Acrylate, hydroxyl-containing (meth) acrylate such as glycerol (meth) acrylate, (meth) acrylic acid, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxypropyl phthalic acid, 2- (meth) acryloyloxyethyl maleic acid, 2- (meth) acryloyloxypropyl maleic acid, 2- ( TA) carboxyl group-containing monomers such as acryloyloxyethyl succinic acid, 2- (meth) acryloyloxypropyl succinic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, monomethyl itaconate, maleic anhydride, anhydrous Acid anhydride group-containing monomer such as itaconic acid, epoxy group-containing monomer such as glycidyl (meth) acrylate, glycidyl α-ethyl acrylate, 3,4-epoxybutyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate Examples thereof include alkoxy polyalkylene glycol (meth) acrylates such as N, N-dimethylacrylamide, hydroxyethylacrylamide and the like.

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

The glass transition temperature (Tg) of the macromonomer is preferably higher than the glass transition temperature of the copolymer component constituting the acrylic copolymer (A1).
Specifically, since the glass transition temperature (Tg) of the macromonomer affects the heating and melting temperature (hot melt temperature) of the adhesive layer 2, the glass transition temperature (Tg) of the macromonomer is 30 ° C to 120 ° C. Among them, it is preferable to be 40 ° C or higher or 110 ° C or lower, and it is more preferable to be 50 ° C or higher or 100 ° C or lower.
With such a glass transition temperature (Tg), by adjusting the molecular weight, it is possible to maintain excellent processability and storage stability, and to adjust so as to hot-melt near 80 ° C.
The glass transition temperature of the macromonomer refers to the glass transition temperature of the macromonomer itself, and can be measured with a differential scanning calorimeter (DSC).

Further, at room temperature, the branch components are attracted to each other and can maintain a state where they are physically cross-linked as a pressure-sensitive adhesive composition, and the physical cross-linking is released by heating to an appropriate temperature. In order to obtain fluidity, it is also preferable to adjust the molecular weight and content of the macromonomer.
From such a viewpoint, the macromonomer is preferably contained in the acrylic copolymer (A1) in a proportion of 5% by mass to 30% by mass, particularly 6% by mass or more and 25% by mass or less, and more preferably 8% by mass. It is preferable that the amount is 20% by mass or more.
The number average molecular weight of the macromonomer is preferably 500 or more and less than 8000, more preferably 800 or more and less than 7500, and particularly preferably 1000 or more and less than 7000.
As the macromonomer, a generally produced one (for example, a macromonomer manufactured by Toa Gosei Co., Ltd.) can be appropriately used.

The high molecular weight skeleton component of the macromonomer is preferably composed of an acrylic polymer or a vinyl polymer.
Examples of the high molecular weight skeleton component of the macromonomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. , Sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) ) Acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, t-butylcyclohexyl ( (Meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) ) Acrylate, isobornyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, 3,5,5-trimethylcyclohexane acrylate, p-cumylphenol EO modified (meth) acrylate, dicyclopentanyl (meth) acrylate, di Cyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, benzyl (meth) acrylate, hydroxyalkyl (meth) acrylate, (meth) acrylic acid, (Meth) acrylate monomers such as lysidyl (meth) acrylate, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, (meth) acrylonitrile, alkoxyalkyl (meth) acrylate, alkoxypolyalkylene glycol (meth) acrylate, , Styrene, t-butyl styrene, α-methyl styrene, vinyl toluene, alkyl vinyl monomer, vinyl acetate, alkyl vinyl ether, hydroxyalkyl vinyl ether, and other various vinyl monomers. These may be used alone or in combination of two or more. can do.

  Examples of the terminal polymerizable functional group of the macromonomer include a methacryloyl group, an acryloyl group, and a vinyl group.

(Crosslinking agent (b))
As the crosslinking agent (b), a crosslinking monomer used when the acrylic ester polymer is crosslinked can be used. For example, at least one crosslinkable functional group selected from (meth) acryloyl group, epoxy group, isocyanate group, carboxyl group, hydroxyl group, carbodiimide group, oxazoline group, aziridine group, vinyl group, amino group, imino group, and amide group The crosslinking agent which has can be mentioned, You may use 1 type or in combination of 2 or more types.
The crosslinkable functional group may be protected with a deprotectable protecting group.

  Above all, a polyfunctional organic function having two or more organic functional groups such as a polyfunctional (meth) acrylate having two or more (meth) acryloyl groups, an isocyanate group, an epoxy group, a melamine group, a glycol group, a siloxane group or an amino group. An organometallic compound having a metal complex such as a base resin, zinc, aluminum, sodium, zirconium, or calcium can be preferably used.

  Examples of the polyfunctional (meth) acrylate include 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin di (meth) acrylate, glycerin glycidyl ether di (meth) acrylate, 1 , 6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol A polyalkoxydi (meth) Acrylate, bisphenol F polyalkoxy di (meth) acrylate, polyalkylene glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, ε-caprolactone modified tris 2-hydroxyethyl) isocyanurate tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, propoxy Pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyethylene glycol di (meth) acrylate, tris (acryloxyethyl) isocyanurate, pentaerythritol tetra (meth) ) Acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) Di (meta) of ε-caprolactone adducts of acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydroxypentylglycol dipentaglycol di (meth) acrylate, hydroxybivalic acid neopenglycol ) In addition to UV-curable polyfunctional monomers such as acrylate, trimethylolpropane tri (meth) acrylate, alkoxylated trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, polyester (meth) acrylate, Polyfunctional acrylic oligomers such as epoxy (meth) acrylate, urethane (meth) acrylate, and polyether (meth) acrylate can be exemplified.

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

  The content of the crosslinking agent is 0.1 to 20 parts by mass with respect to 100 parts by mass of the (meth) acrylic copolymer, from the viewpoint of balancing the flexibility and cohesive force of the pressure-sensitive adhesive composition. In particular, the ratio is preferably 0.5 parts by mass or more and 15 parts by mass or less, and particularly preferably 1 part by mass or more or 13 parts by mass or less.

(Photopolymerization initiator (c))
When crosslinking the acrylic ester polymer, a crosslinking initiator (peroxidation initiator, photopolymerization initiator) and reaction catalyst (tertiary amine compound, quaternary ammonium compound, tin laurate compound, etc.) are appropriately used. It is effective when added.

In the case of UV irradiation crosslinking, it is preferable to blend a photopolymerization initiator (c).
The photopolymerization initiator (c) is roughly classified into two types depending on the radical generation mechanism. The photopolymerization initiator is capable of generating a radical by cleaving the single bond of the photopolymerization initiator itself, and photoexcitation. In general, the initiator and the hydrogen donor in the system form an exciplex and can be roughly classified into a hydrogen abstraction type photopolymerization initiator that can transfer hydrogen of the hydrogen donor.
Among these, the cleavage type photopolymerization initiator is decomposed when a radical is generated by light irradiation to be another compound, and once excited, it does not function as a reaction initiator. For this reason, when the intramolecular cleavage type is used as a photopolymerization initiator having an absorption wavelength in the visible light region, light-reactive light is obtained after the pressure-sensitive adhesive sheet is cross-linked by light irradiation as compared with the case of using a hydrogen abstraction type. A polymerizable initiator is preferable because it remains as an unreacted residue in the pressure-sensitive adhesive composition and is unlikely to cause an unexpected change with time or promotion of crosslinking. Further, the coloring specific to the photopolymerizable initiator is also preferable because it becomes a reaction decomposition product, so that absorption in the visible light region is eliminated and a color to be erased can be appropriately selected.
On the other hand, a hydrogen abstraction type photopolymerization initiator does not generate a decomposition product such as a cleavage type photopolymerization initiator during radical generation reaction by irradiation of active energy rays such as ultraviolet rays, so that it is difficult to become a volatile component after completion of the reaction. Damage to the body can be reduced.

  Examples of the cleavage type photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexyl phenyl ketone, and 2-hydroxy-2-methyl-1-phenyl-propane-1. -One, 1- (4- (2-hydroxyethoxy) phenyl) -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- [4- {4- (2-hydroxy- 2-methyl-propionyl) benzyl} phenyl] -2-methyl-propan-1-one, oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone), phenylglyoxy Methyl lickate, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 -One, 2- (dimethylamino) -2 -[(4-Methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6 -Trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphine oxide, and their derivatives Can be mentioned.

Among these, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine is a cleavage-type photopolymerization initiator, and becomes a degradation product after the reaction and discolors. Acylphosphine oxide photoinitiators such as fin oxide, (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphine oxide are preferred.
Furthermore, from the compatibility with an acrylic copolymer comprising a graft copolymer having a macromonomer as a branch component, 2,4,6-trimethylbenzoyldiphenylphosphine oxide as a photopolymerization initiator, It is preferable to use 6-trimethylbenzoyl) ethoxyphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphine oxide, and the like.

The content of the photopolymerization initiator is not particularly limited. For example, 0.1 to 10 parts by weight with respect to 100 parts by weight of the (meth) acrylic copolymer, particularly 0.2 to 5 parts by weight, and more preferably 0.5 to 3 parts by weight. It is particularly preferable to include them in proportions. However, this range may be exceeded in balance with other elements.
A photoinitiator can be used 1 type or in combination of 2 or more types.

  In addition to the above components, pigments such as pigments and dyes having near-infrared absorption characteristics, tackifiers, antioxidants, antioxidants, hygroscopic agents, ultraviolet absorbers, silane coupling agents, natural products, Various additives such as synthetic resins, glass fibers and glass beads can be appropriately blended.

(Layer structure and thickness of adhesive layer)
The adhesive material layer may be a single layer or a plurality of layers such as two layers or three layers.
The pressure-sensitive adhesive layer may have a structure in which a base layer (non-sticky layer) is provided as a core layer, and layers made of a pressure-sensitive adhesive are laminated on both sides of the base layer. . In the case of such a configuration, the base material layer as the core layer preferably has a material and characteristics such that the pressure-sensitive adhesive sheet laminate can be heat-molded. Further, the adhesive layer excluding the base material layer has the above-described characteristics with respect to loss tangent tan δ (SA), loss tangent tan δ (SB), storage elastic modulus G ′ (SA), and storage elastic modulus G ′ (SB). It is preferable.

The thickness of the adhesive layer is not particularly limited. Among these, a range of 20 μm to 500 μm is preferable. If it is this range, if it is a thin adhesive material layer like thickness 20 micrometers, the adhesive sheet excellent in the printing level | step difference followable | trackability can be provided. Moreover, in the thick adhesive material layer having a thickness of 500 μm, it is possible to suppress the overflow of the adhesive material at the time of pasting because the portion corresponding to the printing step is shaped in advance.
Accordingly, the thickness of the pressure-sensitive adhesive layer is preferably 20 μm to 500 μm, more preferably 30 μm or more and 300 μm or less, and particularly preferably 50 μm or more or 200 μm or less.

<Coating part I>
As shown in FIG. 1, the pressure-sensitive adhesive sheet laminate includes a covering portion I that is detachably laminated on one side of the pressure-sensitive adhesive layer, for example, on the side that forms irregularities on the surface.

The storage elastic modulus E ′ (MA) at 100 ° C. of the covering portion I is preferably 1.0 × 10 ^{6 to} 2.0 × 10 ⁹ Pa.
Since the temperature at which the pressure-sensitive adhesive sheet laminate is heat molded is usually 70 to 120 ° C., the storage elastic modulus E ′ (MA) at 100 ° C. is 1.0 × 10 ^{6 to} 2.0 × 10 ⁹ Pa. For example, in the temperature range where the pressure-sensitive adhesive composition is plasticized or fluidized, the covering portion I is not only deformable by following the uneven shape sufficiently, but also on the surface of the pressure-sensitive adhesive layer pressed by the covering portion I during molding. The desired uneven shape can be molded with high accuracy, for example, so that the corners are not rounded.

  Conventionally, a high storage elastic modulus, in other words, a “hard” material has been frequently used as a release film laminated on an adhesive sheet. This is because the properties required for the release film were mainly the protection of the adhesive layer and the release property. However, according to the study by the present inventors, when a new problem of heat moldability is required in a new application of heat forming in a state where a release film is laminated on an adhesive sheet, a conventional release is required. It has been found that the above-mentioned physical properties provided in the mold film cannot be achieved. For this reason, as a result of scrutinizing the phenomena occurring during heat molding and the characteristics of the adhesive layer, it is a new problem of heat moldability that has characteristics different from those of the release films that have been generally used so far. It has been found that it is advantageous for solving the problem. In particular, it has been found that the above problem can be solved by controlling the storage elastic modulus at a specific temperature within a specific range.

From such a viewpoint, the storage elastic modulus E ′ (MA) at 100 ° C. of the covering portion I is preferably 1.0 × 10 ^{6 to} 2.0 × 10 ⁹ Pa, and more preferably 5.0 × 10 ⁶ Pa or more. 1.0 × 10 ⁹ Pa or less, more preferably 1.0 × 10 ⁷ Pa or more or 5.0 × 10 ⁸ Pa or less.

Further, the storage elastic modulus E '(MB) at 30 ° C. of the covering portion I is preferably at ^{5.0 × 10 7 ~1.0 × 10 10} Pa.
If the storage elastic modulus E ′ (MB) at 30 ° C. of the covering part I is 5.0 × 10 ^{7 to} 1.0 × 10 ¹⁰ Pa, shape retention can be maintained in a normal state, and handling is easy. For example, since it is easy to peel off and is not too hard, it is possible to suppress unnecessary undesired unevenness on the adhesive layer.
From this viewpoint, the storage elastic modulus E ′ (MB) at 30 ° C. of the covering portion I is preferably 5.0 × 10 ^{7 to} 1.0 × 10 ¹⁰ Pa, and more preferably 1.0 × 10 ⁸ Pa or more. 8.0 × 10 ⁹ Pa or less, more preferably 1.0 × 10 ⁹ Pa or more or 5.0 × 10 ⁹ Pa or less.

  In order to adjust the storage elastic modulus at 30 ° C. and 100 ° C. of the coating part I as described above, for example, the type of the base resin, the copolymer resin component, the weight average molecular weight, the glass transition temperature, the crystallinity, etc. While adjusting the conditions of the material, it can be adjusted by adjusting the presence / absence of stretching, molding conditions, and in the case of stretching, production conditions such as stretching conditions. However, it is not limited to these methods.

Furthermore, it is preferable that the storage elastic modulus E ′ (MA) of the covering portion I at 100 ° C. and the storage elastic modulus E ′ (MB) of the covering portion I at 30 ° C. satisfy the following relational expression (1).
(1) ... E '(MB) / E' (MA) ≧ 2.0

If the storage elastic modulus E ′ (MA) of the covering portion I at 100 ° C. and the storage elastic modulus E ′ (MB) of the covering portion I at 30 ° C. satisfy the relational expression (1), sufficient formability can be obtained. More preferably.
From this viewpoint, it is preferable that E ′ (MB) / E ′ (MA) ≧ 2.0, and in particular, 30 ≧ E ′ (MB) / E ′ (MA) or E ′ (MB) / E ′ (MA ) ≧ 3.0, more preferably 10 ≧ E ′ (MB) / E ′ (MA) or E ′ (MB) / E ′ (MA) ≧ 5.0.

  In order to adjust E ′ (MB) and E ′ (MA) to have the above relationship, for example, the type of base resin, copolymer resin component, weight average molecular weight, glass transition temperature, crystallinity, etc. While adjusting the conditions of the material, it can be adjusted by adjusting the presence / absence of stretching, molding conditions, and in the case of stretching, production conditions such as stretching conditions. However, it is not limited to these methods.

Furthermore, the storage elastic modulus G ′ (SA) at 100 ° C. of the pressure-sensitive adhesive layer and the storage elastic modulus E ′ (MA) of the covering portion I at 100 ° C. satisfy the following relational expression (2). preferable.
(2) .. 1.0 × 10 ³ ≦ E ′ (MA) / G ′ (SA) ≦ 1.0 × 10 ⁷

If the storage elastic modulus G ′ (SA) at 100 ° C. of the pressure-sensitive adhesive layer and the storage elastic modulus E ′ (MA) of the covering portion I at 100 ° C. satisfy the relational expression (2), sufficient formability is obtained. Is more preferable.
From this viewpoint, E ′ (MA) / G ′ (SA) is preferably 1.0 × 10 ^{3 to} 1.0 × 10 ⁷ , and more preferably 5.0 × 10 ³ or more or 5.0 × 10 ^6. Hereinafter, it is particularly preferably 1.0 × 10 ⁴ or more or 1.0 × 10 ⁶ or less.

  In order to adjust E ′ (MA) and G ′ (SA) so as to satisfy the above relationship, the characteristics of the adhesive layer or the covering portion I may be adjusted. The characteristics of the pressure-sensitive adhesive layer can be achieved, for example, by adjusting the components, gel fraction, weight average molecular weight, and the like of the composition constituting the pressure-sensitive adhesive layer. In addition, as the characteristics of the covering portion I, for example, the conditions of the material of the covering portion I such as the type of the base resin, the copolymer resin component, the weight average molecular weight, the glass transition temperature, and the crystallinity are adjusted, whether or not there is stretching, molding In the case of stretching, it can be adjusted by adjusting the production conditions such as stretching conditions. However, it is not limited to these methods.

Further, it is preferable that the covering portion I has a peeling force F (C) of 0.2 N / cm or less when peeling the covering portion I from the adhesive layer in an atmosphere of 30 ° C.
When the peeling force F (C) is 0.2 N / cm or less, the covering portion I can be easily peeled from the adhesive material layer.
From such a viewpoint, the peeling force F (C) is preferably 0.2 N / cm or less, more preferably 0.01 N / cm or more or 0.15 N / cm or less, and more preferably 0.02 N / cm. / Cm or more or 0.1 N / cm or less is more preferable.

The covering portion I further has a peeling force F (D) when the pressure-sensitive adhesive sheet laminate is heated to 100 ° C. for 5 minutes and then cooled to 30 ° C., and the covering portion I is peeled off from the pressure-sensitive adhesive layer in a 30 ° C. atmosphere. Is preferably 0.2 N / cm or less.
If the peel force F (D) obtained by heating the pressure-sensitive adhesive sheet laminate at 100 ° C. for 5 minutes and then cooling to 30 ° C. and measuring in an atmosphere at 30 ° C. is approximately the same as the peel force F (C) Even if the pressure-sensitive adhesive sheet laminate is heat-molded, the peeling force F (D) does not change, so that the covering portion I can be easily peeled from the pressure-sensitive adhesive layer.
From this viewpoint, the peeling force F (D) is preferably 0.2 N / cm or less, more preferably 0.01 N / cm or more or 0.15 N / cm or less, and more preferably 0.02 N / cm. / Cm or more or 0.1 N / cm or less is more preferable.

The covering portion I further preferably has an absolute value of a difference between the peeling force F (C) and the peeling force F (D) of 0.1 N / cm or less.
The pressure-sensitive adhesive sheet laminate is heated at 100 ° C. for 5 minutes and then cooled to 30 ° C., and the difference between the peel force F (D) obtained by measurement in an atmosphere at 30 ° C. and the peel force F (C) in a normal state If the absolute value is 0.1 N / cm or less, the peeling force F (D) does not change even if the pressure-sensitive adhesive sheet laminate is heat-molded, so that the covering portion I can be easily peeled from the pressure-sensitive adhesive layer. it can.
From this viewpoint, the absolute value of the difference between the peeling force F (C) and the peeling force F (D) is preferably 0.1 N / cm or less, more preferably 0.08 N / cm or less, and particularly 0.05 N / cm. More preferably, it is as follows.

  Note that the peeling force F (C) and the peeling force F (D) of the covering portion I can be prepared depending on the type of the release layer formed on one side of the covering portion I. However, it is not limited to this method.

  As a structural example of the coating | coated part I, the structural example provided with the coating | coated base material layer and the release layer can be mentioned. By laminating the release layer on one surface of the covering base material layer, the covering portion I can be configured to be easily peeled from the adhesive material layer.

  In this case, the covering base layer is, for example, a stretched or unstretched layer mainly composed of one type of resin or two or more types of resins selected from the group consisting of polyester, copolyester, polyolefin and copolyolefin. That is, it is preferably a single layer or a multilayer having a layer made of a stretched or non-stretched film containing these resins as a main component.

Among them, the covering base layer constituting the covering portion I is, for example, a copolymerized polyester, a polyolefin, or a stretched or non-stretched film containing a copolymerized polyolefin as a main component from the viewpoint of mechanical strength, chemical resistance, and the like. It is preferable that it is a single layer provided with the layer which consists of or multiple layers.
Specific examples of the copolymerized polyester include copolymerized polyethylene terephthalate obtained by arbitrarily copolymerizing isophthalic acid as a dicarboxylic acid, cyclohexanedimethanol, 1,4-butanediol, diethylene glycol, or the like as a diol. it can.
Specific examples of the polyolefin include an α-olefin homopolymer, and examples thereof include a propylene homopolymer and a homopolymer of 4-methylpentene-1.
Specific examples of the polyolefin copolymer include copolymers such as ethylene, propylene, other α-olefins and vinyl monomers.

The release layer is preferably a layer containing a modified polyolefin in addition to a release agent such as silicone.
Here, examples of the modified olefin constituting the release layer include resins mainly composed of an unsaturated carboxylic acid or an anhydride thereof, or a polyolefin modified with a silane coupling agent.

  Examples of the unsaturated carboxylic acid or its anhydride include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, citraconic acid, citraconic anhydride, itaconic acid, itaconic anhydride or monoepoxy compounds of these derivatives and the acid. Ester compounds, polymers having a group capable of reacting with these acids in the molecule, and reaction products of the acids. These metal salts can also be used. Among these, maleic anhydride is more preferably used. Moreover, these copolymers can be used individually or in mixture of 2 or more types, respectively.

  In order to produce a modified polyolefin-based resin, for example, these modified monomers can be copolymerized in the stage of polymerizing the polymer in advance, or these modified monomers can be graft-copolymerized to the polymer once polymerized. Further, as the modified polyolefin resin, these modified monomers may be used alone or in combination, and the content thereof is 0.1% by mass or more, preferably 0.3% by mass or more, more preferably 0.5% by mass or more. In the range of 5% by mass or less, preferably 4.5% by mass or less, more preferably 4.0% by mass or less is preferably used. Of these, those that have been graft-modified are preferably used.

  Preferable examples of the modified polyolefin resin include maleic anhydride modified polypropylene resin, maleic anhydride modified polyethylene resin, maleic anhydride ethylene-vinyl acetate copolymer and the like.

  From the viewpoint of moldability, the thickness of the covering portion I is preferably 10 μm to 500 μm, more preferably 20 μm or more and 300 μm or less, and particularly preferably 30 μm or more or 150 μm or less.

<Coating II>
As described above, this pressure-sensitive adhesive sheet laminate has a covering portion I laminated on the front and back sides of the pressure-sensitive adhesive layer so as to be peelable, and is peelable on the opposite side of the covering portion I, that is, on the other side of the pressure-sensitive adhesive layer It can be set as the structure which laminate | stacks the coating | coated part II. Thus, handling property can be improved by laminating | stacking the coating | coated part II on the front and back other side of an adhesive material layer so that peeling is possible. However, a configuration in which the covering portion II is not stacked is also possible.

  The covering part II is not particularly limited in its material and configuration as long as it is formed by being detachably laminated on the other side of the adhesive material layer.

The covering portion II may be, for example, the same laminated structure and material as the covering portion I, and may be the same thickness as the covering portion I or a different thickness.
If the covering part II is the same laminate structure and material as the covering part I, it is possible to prevent warping from occurring when the present adhesive sheet laminate is heated.

The covering portion II has the same configuration as the covering portion I, but has a storage elastic modulus E ′ (MA) at 100 ° C., a storage elastic modulus E ′ (MB) at 30 ° C., and a ratio thereof (E ′ (MB) / E ′). (MA)), peel force F (C), peel force F (D), and the like may be different from those of the covering portion I.
Further, the covering portion II may have a laminated structure and material different from those of the covering portion I.
For the covering part II, for example, a generally used release film (also referred to as “release film”) can be used. Specifically, a material whose storage elastic modulus E ′ (MC) at 100 ° C. is 2.0 × 10 ^{9 to} 1.0 × 10 ¹¹ Pa, for example, a biaxially stretched polyethylene terephthalate (PET) film is used. Etc. can be used.

(Method for producing this pressure-sensitive adhesive sheet laminate)
As an example of the method for producing the present pressure-sensitive adhesive sheet laminate, there can be mentioned, for example, a method in which a pressure-sensitive adhesive composition is sandwiched between two covering parts I or II and a pressure-sensitive adhesive layer is formed using a laminator. Moreover, as another method, the method of apply | coating an adhesive composition to the coating | coated part I or II, and forming the adhesive material layer can be mentioned. However, it is not limited to this manufacturing method.
Examples of the method for applying the pressure-sensitive adhesive composition include conventionally known coating methods such as reverse roll coating, gravure coating, bar coating, and doctor blade coating.

[This shaped adhesive sheet laminate]
Using this pressure-sensitive adhesive sheet laminate, a shaped pressure-sensitive adhesive sheet laminate 1 (referred to as “the present shaped pressure-sensitive adhesive sheet laminate 1”) having an uneven shape formed on the surface of the pressure-sensitive adhesive layer is produced as follows. Can do.

As shown in FIG. 3, the shaped adhesive sheet laminate 1 includes an adhesive material layer 2, a covering portion I that is detachably laminated on the front and back sides of the adhesive material layer 2, and the adhesive material layer 2. And the other side of the front and back of the cover part II that is laminated in a peelable manner,
The pressure-sensitive adhesive layer 2 includes a concave portion, a convex portion, or an uneven portion (referred to as “adhesive sheet surface uneven portion 2B”) on the front and back one side surface 2A, and the front and back other side surface 2C is a flat surface,
The covering portion I is in close contact with the front and back one side surface 2A of the pressure-sensitive adhesive sheet 2 and includes a concave portion, a convex portion, or an uneven portion (referred to as “covering portion surface uneven portion 3B”) on the front and back one side surface 3A. In addition, the sheet back surface 3C is provided with a convex portion, a concave portion or a convex concave portion (referred to as "protective sheet back surface convex concave portion 3D") that coincides with the adhesive sheet surface concave and convex portion 2B, in other words, is fitted.
The covering portion II may have a configuration including a flat surface along the front and back other surface 2C of the pressure-sensitive adhesive sheet 2.

  The front and back other surface 2C can be a flat surface as shown in FIG. 3, and the front and back other surface 2C can also be formed to have a concave portion, a convex portion, or an uneven portion. it can.

As shown in FIG. 2, the present shaped adhesive sheet laminate 1 having such a structure is formed by subjecting the present adhesive sheet laminate to press molding, vacuum forming, pressure forming, or roll forming, thereby stacking the present adhesive sheet laminate. It can be manufactured by shaping the concavo-convex shape integrally with the body.
By manufacturing in this way, the pressure-sensitive adhesive sheet surface uneven portion 2B of the pressure-sensitive adhesive layer 2, the protective sheet surface uneven portion 3B and the protective sheet back surface concave / convex portion 3D of the covering portion I have unevenness corresponding to the same location, respectively. It can be.

The pressure-sensitive adhesive layer 2 can be used as a double-sided pressure-sensitive adhesive sheet for bonding together two image display device constituent members (each also referred to as “adhered body”) constituting the image display device, for example.
That is, the pressure-sensitive adhesive sheet surface uneven portion 2B in the pressure-sensitive adhesive layer 2 is a concave portion, a convex portion, or a concave-convex portion (“adhered surface uneven portion”) on the bonding surface (also referred to as “bonding surface”) of the adherend. So that they can be formed in the same contour shape. Therefore, the adhesive sheet surface uneven part 2B in the shaped adhesive sheet laminate 1 can be fitted to the adherend surface uneven part in the image display device constituting member as the adherend.

Here, as the image display device, for example, a smartphone or a tablet including a liquid crystal display device (LCD), an organic EL display device (OLED), electronic paper, a micro electro mechanical system (MEMS) display, a plasma display (PDP), and the like A terminal, a mobile phone, a television, a game machine, a personal computer, a car navigation system, an ATM, a fish finder, and the like can be given. However, it is not limited to these.
The image display device constituent member as the adherend is a member constituting these image display devices, and examples thereof include a surface protection panel, a touch panel, and an image display panel. 1 can be used for bonding any two adherends selected from, for example, a surface protection panel, a touch panel, and an image display panel. For example, it can be used to bond a surface protection panel and a touch panel, or a touch panel and an image display panel. However, the adherend is not limited to these.

<Manufacturing method>
Here, the detail of the manufacturing method of this shaped adhesive sheet laminated body 1 is demonstrated.

As described above, as shown in FIG. 2, by manufacturing the pressure-sensitive adhesive sheet laminate by heating and forming it, the concave-convex shape is integrally formed on the pressure-sensitive adhesive sheet laminate 1. Can do.
In this case, examples of the forming method include press forming, vacuum forming, pressure forming, forming by a roll, forming by lamination, and the like. Among these, press molding is particularly preferable from the viewpoints of moldability and workability.

A more specific example will be described.
The pressure-sensitive adhesive sheet laminate is preheated with a heater, and the pressure-sensitive adhesive sheet laminate is transported to a press molding machine when it is heated to a predetermined temperature, and has a shape corresponding to the printed step shape of the adherend in advance. By performing press working with a mold and cooling, the shape of the pressure-sensitive adhesive sheet laminate 1 can be produced by transferring the shape of the mold to one side of the pressure-sensitive adhesive sheet laminate and forming the unevenness on one side. .

  At this time, the preheating of the pressure-sensitive adhesive sheet laminate is preferably performed at a temperature at which the pressure-sensitive adhesive layer is softened, specifically, 70 to 120 ° C.

The material of the type | mold used for uneven | corrugated shaping is not specifically limited. For example, resin-based materials such as silicone resin and fluororesin, and metal-based materials such as stainless steel and aluminum can be used. Among these, metal molds that can be controlled in temperature during molding are particularly preferred because high-precision moldability is required for forming irregularities on the adherend.
Further, the cooling after the press working may be performed after the mold is opened, or the mold may be cooled and cooled at the same time as pressing.

In the present invention, molding conditions such as pressing pressure and pressing time are not particularly specified, and may be appropriately adjusted depending on the dimension and shape to be molded, the material to be used, and the like.
Moreover, you may cut using a Thomson blade, a rotary blade, etc. after a shaping | molding process.

<Application>
Here, an example of the usage of the shaped adhesive sheet laminate 1 will be described.
In recent years, as mobile phones, smartphones, tablet terminals, and the like are generalized, there are many cases in which an image display unit is damaged by a user accidentally dropping it. In particular, when the image display device is a touch panel system, not only the display becomes difficult to see due to breakage, but also the touch panel operation itself becomes impossible or causes a failure due to a physical failure or water intrusion. Therefore, there is a case where repair, that is, repair, in which only the image display unit is replaced, is performed.
In the repair of the image display device, the adhesive sheet is also used when a new image display unit is loaded. Usually, repair is often performed as a manual work by a repair worker, and skill of the repair worker is required. That is, if it is not an expert, when an image display part is loaded via an adhesive sheet, air will enter inside or an adhesive material will protrude.
On the other hand, if this shaped adhesive sheet laminate 1 is used, a highly accurate step shape or the like can be given in advance. For example, a step shape corresponding to the model of the image display device is given in advance to the adhesive material layer. By doing so, the repair work is greatly simplified and can be carried out without requiring the skill of a repair worker. Thus, the pressure-sensitive adhesive sheet laminate of the present invention can be usefully used for repairing image display devices.

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

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

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

<Measurement and evaluation method>
First, measurement methods and evaluation methods for various physical property values of samples obtained in Examples and Comparative Examples will be described.

(Elastic modulus of the coating)
The covering portions A to D used in the examples and comparative examples were cut into a length of 50 mm and a width of 4 mm, respectively, and the distance between chucks was 25 mm using a dynamic viscoelastic device (ITA Measurement Control Co., Ltd. DVA-200). % Strain was measured. The measurement temperature range was −50 ° C. to 150 ° C., the frequency was 1 Hz, and the temperature increase rate was 3 ° C./min. The value of the storage elastic modulus at 100 ° C. of the obtained data was E ′ (MA), and the value of the storage elastic modulus at 30 ° C. was E ′ (MB).

(Elastic modulus of adhesive layer)
The pressure-sensitive adhesive layers obtained in Examples and Comparative Examples were stacked to a thickness of 1 mm and measured using a rheometer (MARSII manufactured by Thermo Fisher Scientific). The measurement temperature range was −50 ° C. to 150 ° C., the frequency was 1 Hz, and the temperature increase rate was 3 ° C./min. In the obtained data, the storage elastic modulus value at 100 ° C. is G ′ (SA), the loss elastic modulus value is G ″ (SA), the storage elastic modulus value at 30 ° C. is G ′ (SB), and the loss elastic modulus. The rate value was G ″ (SB), and the value of G ″ / G ′ under each temperature condition was the loss tangent tan δ (SA, SB) of each adhesive material layer.

(Gel fraction)
The gel fraction of the adhesive material layer was obtained by collecting about 0.05 g of each of the adhesive material layers obtained in Examples and Comparative Examples, and wrapping them in a bag shape with a SUS mesh (# 200) whose mass (X) was measured in advance. The bag mouth was folded and closed, and the mass (Y) of the packet was measured. Then, the bag was immersed in 100 ml of ethyl acetate and stored in the dark at 23 ° C. for 24 hours. The ethyl acetate attached by heating for a period of time was evaporated, the mass (Z) of the dried packet was measured, and the obtained mass was determined by substituting it into the following formula.
Gel fraction [%] = [(Z−X) / (Y−X)] × 100

(Formability)
In order to confirm the moldability, molding tests of Examples and Comparative Examples were performed using the molds described below. That is, as shown in FIG. 5, the upper and lower molds of the molding mold are convex molds having a length of 270 mm, a width of 170 mm, and a thickness of 40 mm, and the upper and lower molds have a length of 270 mm, The aluminum plate was 170 mm wide and 40 mm thick.
As shown in FIG. 5, a convex portion having a length of 187 mm, a width of 125 mm, and a height of 1 mm is provided in the center on the molding surface of the convex mold, and the depth is 25 μm and 50 μm in the molding surface of the convex portion. , 75 μm and 100 μm, four rectangular concave portions (89 mm long and 58 mm wide) in plan view are provided.

The covering portions A to D of the shaped pressure-sensitive adhesive sheet laminate having irregularities formed by the methods described in Examples and Comparative Examples are peeled off, and a concave portion corresponding to a printing step and a convex portion corresponding to a display surface Were measured in a non-contact manner using a scanning white interference microscope.
Measure the height h of the convex part (edge part with the concave part) of the molded body with respect to the depth of the mold of 100 μm, and the transfer rate derived from the following calculation formula is 50% or more: ○, less than 50% Each was evaluated as x.
Transfer rate (%) = h (molded body height) / 100 (mold depth) × 100

(Peeling force)
The pressure-sensitive adhesive sheet laminates produced in Examples and Comparative Examples were cut into a length of 150 mm and a width of 50 mm, and a 180 ° peel test was performed at a test speed of 300 mm / min on the interface between the coating parts A to D and the pressure-sensitive adhesive layer.
Covering parts A to D were values obtained with F (D) being the peel force after 30 minutes of natural cooling to 30 ° C after heating for 5 minutes at 100 ° C and F (C). It was set as the peeling force.

<Coating part I>
The following coating | coated part A-the coating | coated part D was used for the coating | coated part I of the adhesive sheet laminated body in an Example and a comparative example. The value of each storage modulus is shown in Table 1.

Covering part A: a film obtained by laminating a release layer (thickness: 2 μm) made of a silicone compound on one side of a biaxially stretched isophthalic acid copolymerized PET film (thickness: 75 μm).
Covering part B: a film obtained by laminating a release layer (thickness: 38 μm) made of modified polyolefin on one side of an unstretched polyolefin film (thickness: 50 μm) made of 4-methylpentene-1.
Covering part C: A film made of a polyolefin film (thickness: 70 μm) made of unstretched polypropylene.
Covering part D: a film obtained by laminating a release layer (thickness: 2 μm) made of a silicone compound on one side of a biaxially stretched homo-PET film (thickness: 75 μm).

<Example 1>
(Production of double-sided PSA sheet)
As the (meth) acrylic copolymer (a), a polymethyl methacrylate macromonomer having a number average molecular weight of 2400 (Tg: 105 ° C.) 15 parts by mass (18 mol%) and butyl acrylate (Tg: −55 ° C.) 81 parts by mass 1 kg of an acrylic copolymer (a-1) (weight average molecular weight 230,000) obtained by random copolymerization of (75 mol%) and 4 parts by mass (7 mol%) of acrylic acid (Tg: 106 ° C.), and a crosslinking agent As (b), glycerin dimethacrylate (manufactured by NOF Corporation, product name: GMR) (b-1) 90 g, and photopolymerization initiator (c) as 2,4,6-trimethylbenzophenone and 4-methylbenzophenone 15 g of a mixture (manufactured by Lanberti, product name: Ezacure TZT) (c-1) was uniformly mixed to prepare a resin composition 1 used for an adhesive layer. The obtained resin composition had a glass transition temperature of −5 ° C.

  The obtained resin composition 1 was sandwiched between two pieces of a PET film (Mitsubishi Resin, product name: Diafoil MRV-V06, thickness: 100 μm) and a coating part A, and a laminator was used. The pressure-sensitive adhesive sheet laminate 1 was produced by shaping the resin composition 1 into a sheet shape so that the thickness was 100 μm. In addition, it arrange | positioned so that the mold release layer side of the coating | coated part A might contact | connect the resin composition 1. FIG.

The obtained pressure-sensitive adhesive sheet laminate 1 was thermoformed by the following process using a vacuum / pressure forming machine (Daiichi Jitsugyo Co., Ltd., FKS-0632-20 type) to produce a shaped pressure-sensitive adhesive sheet laminate 1. .
That is, with an IR heater preheated to 400 ° C., the surface of the pressure-sensitive adhesive sheet laminate 1 was heated to 100 ° C., and then cooled to 25 ° C., using a molding die with a clamping pressure of 8 MPa. A shaped pressure-sensitive adhesive sheet laminate 1 formed by press forming for 2 seconds and forming irregularities on the surface was produced.

<Example 2>
Except having used the coating | coated part B instead of the said coating | coated part A, it carried out similarly to Example 1, and produced the adhesive sheet laminated body 2 and the shaping adhesive sheet laminated body 2. As shown in FIG.

<Example 3>
Except having used the coating | coated part C instead of the said coating | coated part A, it carried out similarly to Example 1, and produced the adhesive sheet laminated body 3 and the shaped adhesive sheet laminated body 3. FIG.

<Comparative Example 1>
Except having used the coating | coated part D instead of the said coating | coated part A, it carried out similarly to Example 1, and produced the adhesive sheet laminated body 4 and the shaped adhesive sheet laminated body 4. FIG.

  The evaluation results of the pressure-sensitive adhesive sheet laminates 1 to 4 and the shaped pressure-sensitive adhesive sheet laminates 1 to 4 obtained in Examples and Comparative Examples are shown in Table 1.

From the results of Table 1 and FIG. 4 and the test results conducted so far, as shown in Examples 1 to 3, the storage elastic modulus E ′ (MB) at 30 ° C. is 5.0 × 10 ⁷ to 1. A covering part having a storage elastic modulus E ′ (MA) at 100 ° C. of 0 × 10 ¹⁰ Pa and a storage elastic modulus E ′ (MA) of 1.0 × 10 ^{6 to} 2.0 × 10 ⁹ Pa is laminated on the pressure-sensitive adhesive layer. By performing, it confirmed that an uneven | corrugated shape could be shape | molded with high precision to an adhesive material layer.
On the other hand, as shown in Comparative Example 1, when a biaxially stretched homo-PET film that is generally widely used as a release film is used, the storage elastic modulus of the coating exceeds 2.0 × 10 ⁹ Pa even in a high temperature range. Even when thermoformed, sufficient unevenness could not be formed on the adhesive layer.
From the above, the storage elastic modulus E ′ (MB) at 30 ° C. is 5.0 × 10 ^{7 to} 1.0 × 10 ¹⁰ Pa, and the storage elastic modulus E ′ (MA) at 100 ° C. is 1. It was found that a shaped pressure-sensitive adhesive sheet with good irregularities can be obtained by laminating a covering portion of 0 × 10 ^{6 to} 2.0 × 10 ⁹ Pa on the pressure-sensitive adhesive layer and performing molding.

  More preferably, the loss tangent tan δ (A) at 100 ° C. of the adhesive layer satisfies the condition of 1.0 or more, and the loss tangent tan δ (B) at 30 ° C. of the adhesive layer satisfies the condition of less than 1.0. It was also found that more accurate shaping can be achieved by using such a pressure-sensitive adhesive sheet laminate.

  Therefore, by using the pressure-sensitive adhesive sheet laminate as described above, the irregularities corresponding to the printing steps of the image display device as the adherend are accurately shaped, so that there is no gap between the adherend and the printing. It is possible to confirm that a shaped pressure-sensitive adhesive sheet laminate for an image display device that can be satisfactorily bonded without causing the adhesive material to overflow even on an adherend having a narrow frame design can be manufactured. did it.

  Moreover, when it sees about peeling force, the heating-cooling conditions at the time of measuring peeling force F (D), ie, the conditions which carry out natural cooling to 30 degreeC after heating for 5 minutes at 100 degreeC manufacture a shaped adhesive sheet laminated body. This is a typical heating / cooling condition. In any of the above examples, since the absolute value of the difference between the peeling force F (C) and the peeling force F (D) was 0.1 N / cm or less, peeling of the covering portions A to D in the shaped pressure-sensitive adhesive sheet laminate It was confirmed that the force was not different from the peeling force of the covering portions A to D in the pressure-sensitive adhesive sheet laminate.

Claims (12)

In the pressure-sensitive adhesive sheet laminate comprising the pressure-sensitive adhesive layer and the covering portion I laminated in a peelable manner on one side of the pressure-sensitive adhesive layer,
The storage elastic modulus E ′ (MA) of the covering portion I at 100 ° C. is 1.0 × 10 ^{6 to} 2.0 × 10 ⁹ Pa, and the storage elastic modulus E ′ of the covering portion I at 30 ° C. ( adhesive sheet laminated body characterized by MB) is ^{5.0 × 10 7 ~1.0 × 10 10} Pa. The pressure-sensitive adhesive sheet laminate according to claim 1, wherein the storage elastic modulus E '(MA) and the storage elastic modulus E' (MB) satisfy the following relational expression (1).
(1) E ′ (MB) / E ′ (MA) ≧ 2.0   The loss tangent tan δ (SA) at 100 ° C. of the pressure-sensitive adhesive layer is 1.0 or more, and the loss tangent tan δ (SB) at 30 ° C. of the pressure-sensitive adhesive layer is less than 1.0. The pressure-sensitive adhesive sheet laminate according to claim 1 or 2. The adhesive modulus G ′ (SA) at 100 ° C. of the adhesive layer is less than 1.0 × 10 ⁴ Pa, and the storage modulus G ′ (SB) at 30 ° C. of the adhesive layer is 1.0. The pressure-sensitive adhesive sheet laminate according to claim 1, wherein the pressure-sensitive adhesive sheet laminate is × 10 ⁴ Pa or more. The storage elastic modulus E ′ (MA) at 100 ° C. of the covering portion I and the storage elastic modulus G ′ (SA) at 100 ° C. of the pressure-sensitive adhesive layer satisfy the following relational expression (2). The pressure-sensitive adhesive sheet laminate according to any one of claims 1 to 4.
(2) 1.0 × 10 ³ ≦ E ′ (MA) / G ′ (SA) ≦ 1.0 × 10 ⁷ The covering portion I includes a covering base material layer and a release layer,
The covering base material layer has a stretched or non-stretched layer mainly composed of one kind of resin or two or more kinds of resins selected from the group consisting of polyester, copolymerized polyester, polyolefin and copolymerized polyolefin. The pressure-sensitive adhesive sheet laminate according to any one of claims 1 to 5. The pressure-sensitive adhesive sheet laminate according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive layer and the covering portion I satisfy the following conditions (I) to (III).
(I) The peeling force F (C) at the time of peeling the said coating | coated part I from the said adhesive material layer in 30 degreeC atmosphere is 0.2 N / cm or less.
(II) The pressure-sensitive adhesive sheet laminate is heated to 100 ° C. for 5 minutes and then cooled to 30 ° C., and the peeling force F (D) when peeling the covering portion I from the pressure-sensitive adhesive layer in a 30 ° C. atmosphere is 0.2N. / Cm or less.
(III) The absolute value of the difference between the peeling force F (C) and the peeling force F (D) is 0.1 N / cm or less.   The pressure-sensitive adhesive layer is formed from a resin composition containing a (meth) acrylic copolymer (a), a crosslinking agent (b), and a photopolymerization initiator (c). Item 8. The pressure-sensitive adhesive sheet laminate according to any one of Items 1 to 7. A shaped pressure-sensitive adhesive sheet laminate using the pressure-sensitive adhesive sheet laminate according to any one of claims 1 to 8,
The pressure-sensitive adhesive layer includes a concave portion, a convex portion, or an uneven portion (referred to as an “adhesive material layer surface uneven portion”) on the front and back side surfaces, and
The covering portion I is in close contact with the front and back side surfaces of the pressure-sensitive adhesive layer, and has a concave portion, a convex portion, or an uneven portion (referred to as a “cover portion surface uneven portion”) on the front and back side surface, A shaped pressure-sensitive adhesive sheet comprising a convex part or a concave part or a convex concave part (referred to as a "covered part rear surface convex concave part") that has irregularities that coincide with the concave and convex parts on the surface of the adhesive material layer on the front and back other side surfaces opposite to the side Laminated body. The pressure-sensitive adhesive layer is a double-sided pressure-sensitive adhesive sheet for bonding two adherends,
The pressure-sensitive adhesive layer surface unevenness portion corresponds to a concave portion, a convex portion, or an uneven portion (referred to as an “adherent surface unevenness portion”) on the adherend surface of any one of the adherends. The shaped pressure-sensitive adhesive sheet laminate according to claim 9.   The shaped adhesive sheet laminate according to claim 10, wherein any one of the adherends is selected from the group consisting of a surface protection panel, a touch panel, and an image display panel.   Heating the pressure-sensitive adhesive sheet laminate according to any one of claims 1 to 8, and forming a concavo-convex shape on at least one side of the pressure-sensitive adhesive sheet by press molding, vacuum forming, pressure forming, or roll forming. A method for producing a shaped adhesive sheet laminate.

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