JP6984249B2 - Adhesive sheet laminate, excipient adhesive sheet laminate and its manufacturing method - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention can be suitably used when 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, a pen tablet, or the like. The present invention relates to an adhesive sheet laminate and an adhesive sheet laminate suitable for forming a shaped adhesive sheet laminate.

The touch panel type image display device is usually configured by combining a surface protection panel, a touch panel, and an image display panel (collectively, "constituent members for an image display device").
In recent years, the surface protection panel of a touch panel type image display device such as a smartphone or tablet terminal uses a plastic material such as an acrylic resin plate or a polycarbonate plate together with tempered glass, and the peripheral edge other than the visible opening surface of the surface protection panel. The part is printed in black.
In the touch panel, a plastic film sensor is used together with the glass sensor, a member called a touch-on lens (TOR) whose touch panel function is integrated with the surface protection panel is used, and the touch panel function is integrated into 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 image visibility, the gaps between the components for each image display device are filled with a transparent resin such as a liquid adhesive, a thermoplastic adhesive sheet material, or an adhesive sheet material. The filling structure is common.
By the way, in the field of image display devices centered on mobile phones and mobile terminals, in addition to thinning and high precision, the design is diversifying, and the peripheral edge of the surface protection panel is black in a frame shape. In the past, it was common to print the concealed part of the frame, but with the diversification of designs, the frame-shaped concealed part is beginning to be formed in a color other than black. When the concealing portion is formed of a color other than black, the height of the concealing portion, that is, the printed portion tends to be higher than that of black because the concealing property is low. Therefore, it is required that the adhesive sheet for laminating the constituent members provided with such a printing portion is filled to every corner following a large printing step.
Therefore, various methods for filling the printing step have been conventionally proposed.

For example, in Patent Document 1, even if the adherend surface to which the adhesive sheet is bonded has a step due to printing or the like, the adhesive sheet can be bonded to the adherend surface in close contact with each other without a gap, for a new image display device. As the double-sided adhesive sheet, it is a double-sided adhesive sheet for adhering any two adherends selected from the components for an image display device of a surface protection panel, a touch panel, and an image display panel, and at least one of the adherends. The body has a stepped portion on the adhered surface to which the double-sided adhesive sheet is adhered, and the double-sided adhesive sheet has the shape of the bonded surface to be bonded to the adhered surface along the surface shape of the adhered surface. A double-sided adhesive sheet for an image display device, which is shaped, is disclosed.

Further, Patent Document 2 describes a method for manufacturing a double-sided adhesive sheet for bonding any two adherends selected from a surface protection panel, a touch panel and an image display panel. A double-sided pressure-sensitive adhesive sheet for an image display device, which comprises using a pressure-sensitive adhesive composition having a gel content of less than 40% to form a surface shape that is the same as the uneven shape of the bonded surface of the adherend. The manufacturing method is disclosed.

WO2014 / 073316 A1 WO2015 / 174392 A1

In recent years, in the field of image display devices centered on mobile phones and mobile terminals, further thinning and high precision are required, 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 to the outside. As a countermeasure for this, as disclosed in the above-mentioned prior patent documents, it has been studied to form the surface shape of the pressure-sensitive adhesive sheet in advance along the surface shape of the adherend.

Then, in order to form the surface shape of the adhesive sheet along the surface shape of the adherend in advance, the adhesive sheet laminate in which the release sheets are laminated on both sides of the adhesive sheet is press-molded. Therefore, a method of forming an uneven shape that matches the uneven portion on the surface of the adherend is envisioned.
However, as a result of actually carrying out the above method using an adhesive sheet laminate in which ordinary release sheets are laminated on both sides of the adhesive sheet, an uneven shape that matches the uneven portion on the surface of the adherend is obtained. The problem that it is difficult to form on the surface of the adhesive sheet with high accuracy has become clear.

Therefore, the present invention relates to an adhesive sheet laminate provided with an adhesive layer and a coating portion that is detachably laminated on one side of the adhesive layer, and accurately obtains an uneven shape that matches the uneven portion on the surface of the adherend. The present invention proposes 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.

INDUSTRIAL APPLICABILITY The present invention relates to a pressure-sensitive adhesive sheet laminate provided with a pressure-sensitive adhesive layer and a coating portion I that is detachably laminated on one side of the pressure- sensitive adhesive material layer. Is 1.0 or more, the loss tangent tan δ (SB) of the pressure-sensitive adhesive layer at 30 ° C. is less than 1.0, and 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'(MB) of the covering portion I at 30 ° C. is 5.0 × 10 ^{7 to} 1.0 × 10 ¹⁰ Pa. We propose an adhesive sheet laminate characterized by being present.

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

According to the pressure-sensitive adhesive sheet laminated body proposed by the present invention, for example, after heating the pressure-sensitive adhesive sheet laminated body, a mold is pressed against the covering portion I to form a concave-convex shape that matches the uneven portion on the surface of the adherend. Can be formed on the surface of the pressure-sensitive adhesive layer with high accuracy. Further, since the covering portion I can maintain its shape retention under normal conditions, it is not only easy to handle, but also because it is not too hard, it is possible to suppress unnecessary and unintended irregularities on the adhesive layer. can.

The shaped pressure-sensitive adhesive sheet laminate proposed by the present invention is provided with an uneven portion on the front and back surfaces of the pressure-sensitive adhesive layer, and the covering portion I is in close contact with the front and back surfaces of the pressure-sensitive adhesive layer. The surface of one side of the front and back is provided with unevenness on the surface of the covering portion, and the surface of the other side of the front and back opposite to the one side of the front and back is provided with unevenness on the back surface of the covering portion. As described above, in the shaped pressure-sensitive adhesive sheet laminate proposed by the present invention, the covering portion I adheres to the front and back one-side surfaces of the pressure-sensitive adhesive layer without gaps, and is peeled off from the front and back one-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 adhesive material layer and lowering the adhesive strength, and moreover, the adhesive material layer can be prevented from being lowered. The shape of the surface unevenness of the adhesive layer formed on the front and back sides of the surface prevents it from collapsing due to moisture in the air and preventing dust from adhering to the surface and reducing the adhesive strength. You can also do it.

It is sectional drawing which shows typically the example of the pressure-sensitive adhesive sheet laminated body which is an Example of this invention. It is sectional drawing for demonstrating an example of a pressing process at the time of manufacturing a shaped adhesive sheet laminated body using an example of the pressure-sensitive adhesive sheet laminated body which is an Example of this invention. It is a figure which showed the example of the shaping adhesive sheet laminated body which is an Example of this invention schematically, (A) is a sectional view, (B) is a perspective view. It is a figure which showed the viscoelastic curve of the material used for the pressure-sensitive adhesive sheet laminated body produced in an Example / comparative example. It is a perspective view which showed one of the molds used in an Example / 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 embodiments.

[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 off from the pressure-sensitive adhesive layer and the front and back sides of the pressure-sensitive adhesive layer. It is a pressure-sensitive adhesive sheet laminated body including a coated portion I formed by laminating and a covering portion II formed by being peelably laminated on the front and back sides of the pressure-sensitive adhesive layer. Here, the covering portion II is arbitrary, and a configuration in which the covering portion II is not laminated may be used.

<Adhesive layer>
The pressure-sensitive adhesive layer of the present pressure-sensitive adhesive sheet laminate may function as a double-sided pressure-sensitive adhesive sheet when the coating portion I and the coating portion II are peeled off, and may have a hot-melt property that softens or melts when heated. Just do it.

The pressure-sensitive adhesive layer preferably has a loss tangent tan δ (SA) of 1.0 or more at 100 ° C. Further, it is preferable that the loss tangent tan δ (SB) at 30 ° C. is less than 1.0.
Here, the loss tangent tan δ means the ratio (G'' / G') of the loss elastic modulus G'' and the storage elastic modulus G'.
Since the temperature at which the pressure-sensitive adhesive sheet laminate is heat-molded 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 formed on the surface of the pressure-sensitive adhesive layer. Will be easy.
Further, if the loss tangent tan δ (SB) of the adhesive layer at 30 ° C. is less than 1.0, the shape can be maintained under normal conditions, so that the uneven shape matching the uneven portion on the surface of the adherend can be accurately obtained. The state formed on the surface of the adhesive layer can be maintained.
Generally, a polymer material has both a viscous property and an elastic property, and the viscous property becomes stronger as the loss tangent tan δ is 1.0 or more and the value becomes larger. On the other hand, the elastic property becomes stronger as the loss tangent tan δ is less than 1.0 and the value becomes smaller. Therefore, by controlling the loss tangent tan δ at different temperatures of the pressure-sensitive adhesive layer, it is possible to have both moldability and shape retention.

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

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

Further, the storage elastic modulus G'(SA) of the pressure-sensitive adhesive layer at 100 ° C. is preferably less than ^{1.0 × 10 4 Pa.} Further, the storage elastic modulus G'(SB) of the pressure-sensitive adhesive layer at 30 ° C. ^{is preferably 1.0 × 10 4} Pa or more.
When the storage elastic modulus G'(SA) of the pressure-sensitive adhesive layer at 100 ° C. is ^{less than 1.0 × 10 4} Pa, sufficient moldability can be obtained, which is preferable. On the other hand, the storage elastic modulus of the pressure-sensitive adhesive layer at 30 ° C. When 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) of the pressure-sensitive adhesive layer at 100 ° C. ^{is preferably less than 1.0 × 10 4} Pa, and above all, 5.0 × 10 ¹ Pa or more or 5.0 × 10 ³ It is more preferably Pa or less, and more preferably 1.0 × 10 ² Pa or more or 1.0 × 10 ³ Pa or less.
From this viewpoint, the storage elastic modulus G'(SB) of the pressure-sensitive adhesive layer at 30 ° C. ^{is preferably 1.0 × 10 4} Pa or more, and more than 2.0 × 10 ⁴ Pa or more or 1.0 ×. It ^{is more preferably 10 7} Pa or less, and more preferably 5.0 × 10 ⁴ Pa or more or 1.0 × 10 ⁶ Pa or less.

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

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 higher or 130 ° C. or lower, and more preferably 70 ° C. or higher or 110 ° C. or lower. ..
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 it to 50 to 150 ° C.

The glass transition temperature (Tg) of the base resin of the pressure-sensitive adhesive layer is preferably -50 to 40 ° C, particularly -30 ° C or higher or 25 ° C or lower, and particularly -10 ° C or higher or 20 ° C or lower. More 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 raised at a rate of 3 ° C./min using a differential scanning calorimeter (DSC).
When 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 imparted with adhesiveness, and the temperature at which the loss tangent tan δ of the pressure-sensitive adhesive layer becomes 1.0 is set. It can be adjusted to 50 to 150 ° C.

As the material of the pressure-sensitive adhesive layer, a conventionally known pressure-sensitive adhesive sheet can be used as long as it is a material that can be adjusted to a predetermined viscoelastic behavior.
For example, 1) (meth) acrylic acid ester-based polymer (meaning that it contains a copolymer, hereinafter referred to as "acrylic acid ester-based (co) polymer") is used as a base resin, and a cross-linking monomer is required. A pressure-sensitive adhesive sheet formed by blending a cross-linking initiator, a reaction catalyst, etc. and performing a cross-linking reaction according to the above conditions.
2) A pressure-sensitive adhesive sheet formed by using a butadiene or isoprene-based copolymer as a base resin, blending it with a cross-linking monomer, a cross-linking initiator, a reaction catalyst, etc., if necessary, and performing a cross-linking reaction.
3) A pressure-sensitive adhesive sheet formed by using a silicone-based polymer as a base resin, blending it with a cross-linking monomer, and if necessary, a cross-linking initiator, a reaction catalyst, etc., and performing a cross-linking reaction.
4) A polyurethane-based pressure-sensitive adhesive sheet using a polyurethane-based polymer as a base resin can be mentioned.

The physical properties of the pressure-sensitive 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 adhesiveness, transparency, weather resistance, etc., those using the acrylic acid ester-based (co) polymer of 1) above as the base resin are preferable.
When performance such as electrical characteristics and low refractive index is required, those using the butadiene or isoprene-based copolymer of 2) above as the base resin are preferable.
When performance such as heat resistance and rubber elasticity in a wide temperature range is required, those using the silicone-based copolymer of 3) above as a base resin are preferable.
When performance such as removability is required, those using the polyurethane polymer of 4) above as the base resin are preferable.

As an example of the pressure-sensitive adhesive layer, it was formed from a resin composition containing a (meth) acrylic copolymer (a) as a base resin, a cross-linking agent (b), and a photopolymerization initiator (c). An adhesive sheet can be exemplified.
In this case, it is necessary to satisfy the above-mentioned viscoelastic property in the uncrosslinked state, that is, the state before the three-dimensionally crosslinked network structure is formed. From this point of view, the gel fraction of the pressure-sensitive adhesive layer is preferably 40% or less.

When the gel fraction of the pressure-sensitive adhesive layer is 40% or less, the bonds between the molecular chains constituting the pressure-sensitive adhesive layer are suppressed to an appropriate range, and therefore, appropriate fluidity is appropriate when forming into a shaped pressure-sensitive adhesive sheet laminate. Will be able to prepare.
From this point of view, the gel fraction of the pressure-sensitive adhesive layer is preferably 40% or less, particularly preferably 20% or less, and particularly preferably 10% or less. The lower limit of the gel fraction of the pressure-sensitive adhesive layer is not limited and may be 0%.
The gel content of the pressure-sensitive adhesive layer is a resin composition containing a (meth) acrylic copolymer (a), a cross-linking agent (b), and a photopolymerization initiator (c) as a base resin. The same applies not only to the case of using the above but also to the case of using another resin composition as the pressure-sensitive adhesive layer.

((Meta) acrylic copolymer (a))
The (meth) acrylic copolymer (a) appropriately has characteristics such as glass transition temperature (Tg) depending on the type, composition ratio, polymerization conditions, etc. of the acrylic monomer and methacrylic monomer used for polymerizing the copolymer (a). It is possible to adjust.

Examples of the acrylic monomer and methacrylic monomer used for polymerizing the acrylic acid ester polymer include 2-ethylhexyl acrylate, n-octyl acrylate, n-butyl acrylate, ethyl acrylate, and methyl methacrylate. Vinyl acetate, hydroxyethyl acrylate, acrylic acid, glycidyl acrylate, acrylamide, acrylic nitrile, methacrylic nitrile, fluoroacrylate, silicone acrylate and the like obtained by copolymerizing these with a hydrophilic group or an organic functional group can also be used.

Among the acrylic acid ester polymers, the (meth) acrylic acid alkyl ester-based copolymer is particularly preferable.
The (meth) acrylate used to form the (meth) acrylic acid alkyl ester-based copolymer, that is, the alkyl acrylate or the alkyl methacrylate component, has an alkyl group of n-octyl, isooctyl, 2-ethylhexyl, n-butyl, and the like. It is preferably 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.

As other components, acrylates or methacrylates having an organic functional group such as a carboxyl group, a hydroxyl group, and a glycidyl group may be copolymerized. Specifically, a monomer component in which the alkyl (meth) acrylate component and the (meth) acrylate component having an organic functional group are appropriately and selectively combined is heat-polymerized as a starting material, and the (meth) acrylic acid ester-based copolymer is used. A polymer polymer can be obtained.
Of these, one of alkyl acrylates such as iso-octyl acrylate, n-octyl acrylate, n-butyl acrylate, and 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 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, emulsification polymerization, bulk polymerization, and suspension polymerization can be adopted, and at that time, a thermal polymerization initiator or photopolymerization can be adopted depending on the polymerization method. An acrylic acid 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 pressure-sensitive adhesive layer, a (meth) acrylic copolymer (A1) composed of a graft copolymer having a macromonomer as a branch component can be mentioned.

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

The glass transition temperature of the copolymer constituting the stem 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 stem component refers to the glass transition temperature of the polymer obtained by copolymerizing only the monomer component constituting the stem component of the acrylic copolymer (A1). .. Specifically, it means a value calculated by the Fox calculation formula from the glass transition temperature and the composition ratio of the polymer obtained from the homopolymer of each component of the copolymer.
The Fox calculation formula is a calculated value obtained by the following formula, and is a polymer handbook [Polymer HandBook, J. Mol. It can be obtained by using the value described in Brandrup, Interscience, 1989].
1 / (273 + Tg) = Σ (Wi / (273 + Tgi))
[In the formula, Wi indicates the weight fraction of the monomer i, and Tgi indicates the Tg (° C.) of the homopolymer of the monomer i. ]

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

Examples of the (meth) acrylic acid ester monomer contained in the stem component of the acrylic copolymer (A1) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and 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 ( Meta) 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, dicyclopentenyl ( Examples thereof include meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and benzyl (meth) acrylate. These include hydroxyl group-containing (meth) acrylates such as hydroxyethyl (meth) acrylates, hydroxypropyl (meth) acrylates, hydroxybutyl (meth) acrylates, and glycerol (meth) acrylates having hydrophilic groups and organic functional groups, and (meth) acrylates. ) Acrylate, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxypropyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxypropylphthalic acid Acid, 2- (meth) acryloyloxyethyl maleic acid, 2- (meth) acryloyloxypropyl maleic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxypropyl succinic acid, crotonic acid, fumal Carboxyl group-containing monomers such as acid, maleic acid, itaconic acid, monomethyl maleate, monomethyl itaconate, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride, glycidyl (meth) acrylate, α-ethylacrylic acid. Epoxy group-containing monomers such as glycidyl and (meth) acrylic acid 3,4-epoxybutyl, amino group-containing (meth) acrylic acid ester-based monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate, (meth). ) Acrylate, N-t-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, diacetone acrylamide, maleic acid amide, maleimide, etc. It is also possible to use a monomer containing an amide group, a heterocyclic basic monomer such as vinylpyrrolidone, vinylpyridine, vinylcarbazole and the like.
In addition, styrene, t-butyl styrene, α-methyl styrene, vinyl toluene, acrylonitrile, methacrylonitonyl, vinyl acetate, vinyl propionate, alkyl vinyl ether, hydroxyalkyl vinyl ether, and alkyl, which can be copolymerized with the acrylic monomer or methacrylic monomer. Various vinyl monomers such as vinyl monomers can also be appropriately used.

Further, the stem component of the acrylic copolymer (A1) preferably contains a hydrophobic (meth) acrylate monomer and a hydrophilic (meth) acrylate monomer as constituent units.
If the stem component of the acrylic copolymer (A1) is composed of only hydrophobic monomers, there is a tendency for moist heat bleaching. Therefore, it is preferable to introduce hydrophilic monomers into the stem components to prevent moist heat bleaching. ..

Specifically, as the stem 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. Examples thereof include copolymer components obtained by random copolymerization.

Here, examples of the hydrophobic (meth) acrylate monomer include n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, and 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 ( Examples thereof include meta) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylicate, and methyl methacrylate.
Examples of the hydrophobic vinyl monomer include vinyl acetate, styrene, t-butylstyrene, α-methylstyrene, vinyltoluene, and alkylvinyl monomers.

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

It is preferable that the acrylic copolymer (A1) has a macromonomer introduced as a branch component of the graft copolymer and contains a repeating unit derived from the macromonomer.
The macromonomer is a polymer monomer having a polymerizable functional group at the terminal 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 pressure-sensitive adhesive layer 2, the glass transition temperature (Tg) of the macromonomer is 30 ° C to 120 ° C. It is preferably 40 ° C. or higher or 110 ° C. or lower, and more preferably 50 ° C. or higher or 100 ° C. or lower.
With such a glass transition temperature (Tg), by adjusting the molecular weight, excellent processability and storage stability can be maintained, and the temperature can be adjusted to hot melt at around 80 ° C.
The glass transition temperature of the macromonomer refers to the glass transition temperature of the macromonomer itself, and can be measured by a differential scanning calorimeter (DSC).

Further, in a room temperature state, it is possible to maintain a state in which the branch components are attracted to each other and 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 this point of view, 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 or 25% by mass or less, and 8% by mass among them. It is preferably more than or less than 20% by mass.
The number average molecular weight of the macromonomer is preferably 500 or more and less than 8000, and more preferably 800 or more or less than 7500, and more preferably 1000 or more or less than 7000.
As the macromonomer, a generally manufactured one (for example, a macromonomer manufactured by Toagosei 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, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate , Benzyl (meth) acrylate, hydroxyalkyl (meth) acrylate, (meth) acrylic acid, glycidyl (meth) acrylate, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, (meth) acrylic nitrile, alkoxyalkyl ( (Meta) acrylate monomers such as meth) acrylates and alkoxypolyalkylene glycol (meth) acrylates, styrene, t-butyl styrene, α-methyl styrene, vinyl toluene, alkyl vinyl monomers, vinyl acetate, alkyl vinyl ethers, hydroxyalkyl vinyl ethers, etc. Various vinyl monomers can be mentioned, and these can be used alone or in combination of two or more.

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 cross-linking agent (b), a cross-linking monomer used for cross-linking the acrylic acid ester polymer 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 cross-linking agent having the above can be mentioned, and one kind or a combination of two or more kinds may be used.
The crosslinkable functional group may be protected by a deprotectable protecting group.

Among them, a polyfunctional organic functional group 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, and an amino group. Organic metal compounds having a metal complex such as a base resin, zinc, aluminum, sodium, zirconium and calcium can be preferably used.

Examples of the polyfunctional (meth) acrylate include 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerindi (meth) acrylate, and glycering lysidyl ether di (meth) acrylate. , 6-Hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol A polyalkoxydi (meth) Acrylate, bisphenol F polyalkoxydi (meth) acrylate, polyalkylene glycol di (meth) acrylate, trimethylolpropanetrioxyethyl (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, propoxylated pentaerythritol tetra (meth) acrylate, ethoxylated penta Elythritol 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) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydroxyvivarate neopentylglycol di (meth) acrylate, hydroxyvivariate neopenglycol ε- In addition to UV-curable polyfunctional monomers such as di (meth) acrylates of caprolactone adducts, trimethylol propanetri (meth) acrylates, alkoxylated trimethylol propanetri (meth) acrylates, and ditrimethylol propanetetra (meth) acrylates. , Polyfunctional acrylic oligomers such as polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, and polyether (meth) acrylate can be mentioned.

Among the above-mentioned polyfunctional (meth) acrylic acid ester monomers, polar functional groups such as hydroxyl groups, carboxyl groups, and amide groups are among the polyfunctional (meth) acrylic acid ester monomers from the viewpoint of improving the adhesion to the adherend and the effect of suppressing moist heat bleaching. A polyfunctional monomer or oligomer containing the above is preferable. Among them, it is preferable to use a polyfunctional (meth) acrylic acid ester having a hydroxyl group or an amide group.
From the viewpoint of preventing moist heat bleaching, it is preferable to contain a hydrophobic acrylate monomer and a hydrophilic acrylate monomer as a stem component of the (meth) acrylic acid ester copolymer, for example, a graft copolymer. Furthermore, it is preferable to use a polyfunctional (meth) acrylic acid ester having a hydroxyl group as the cross-linking agent.
Further, in order to adjust the effects such as adhesion, moisture resistance and heat resistance, a monofunctional or polyfunctional (meth) acrylic acid ester that reacts with a cross-linking agent may be further added.

The content of the cross-linking 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. It is preferably 0.5 parts by mass or more or 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 cross-linking an acrylic acid ester polymer, a cross-linking initiator (peroxidation initiator, photopolymerization initiator) or reaction catalyst (tertiary amine compound, quaternary ammonium compound, tin laurate compound, etc.) is appropriately used. It is effective when added.

In the case of ultraviolet irradiation cross-linking, it is preferable to add the photopolymerization initiator (c).
The photopolymerization initiator (c) is roughly classified into two types according to the radical generation mechanism, that is, a cleavage type photopolymerization initiator capable of cleaving and decomposing a single bond of the photopolymerization initiator itself to generate a radical, and a photoexcitation. The initiator and the hydrogen donor in the system form an excitation complex, which is roughly classified into a hydrogen abstraction type photopolymerization initiator capable of transferring the hydrogen of the hydrogen donor.
Of these, the cleavage-type photopolymerization initiator decomposes to another compound when a radical is generated by light irradiation, and once excited, it loses its function as a reaction initiator. Therefore, when the intramolecular cleavage type is used as the photopolymerization initiator having an absorption wavelength in the visible light region, the pressure-sensitive adhesive light is crosslinked by light irradiation as compared with the case where the hydrogen extraction type is used. It is preferable because the polymerizable initiator remains in the pressure-sensitive adhesive composition as an unreacted residue and is unlikely to cause an unexpected change over time or promotion of cross-linking of the pressure-sensitive adhesive sheet. Further, the coloring peculiar 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 decolorizing agent can be appropriately selected.
On the other hand, the hydrogen abstraction type photopolymerization initiator does not generate a decomposition product like a cleaved type photopolymerization initiator during a radical generation reaction by irradiation with active energy rays such as ultraviolet rays, so that it is unlikely to become a volatile component after the reaction is completed, and is subject to damage. Damage to the body can be reduced.

Examples of the cleavage-type photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenyl-propane-1. -On, 1- (4- (2-hydroxyethoxy) phenyl) -2-hydroxy-2-methyl-1-propane-1-one, 2-hirodoxy-1- [4- {4- (2-hydroxy-) 2-Methyl-propionyl) benzyl} phenyl] -2-methyl-propane-1-one, oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone), phenylglioxy Methyl rickate 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butane-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 -On, 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-trimethyl Examples thereof include pentylphosphin oxide and derivatives thereof.

Among these, bis (2,4,6-trimethylbenzoyl) -phenylphosphinoxide and 2,4,6-trimethylbenzoyldiphenylphos are the cleavage-type photopolymerizable initiators in that they become decomposition products and decolorize after the reaction. Acylphosphine oxide-based photoinitiators such as finoxide, (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide, and bis (2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphinoxide are preferred.
Further, from the compatibility with an acrylic copolymer composed of a graft copolymer having a macromonomer as a branch component, 2,4,6-trimethylbenzoyldiphenylphosphine oxide as a photopolymerization initiator (2,4) 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 mass, particularly 0.2 parts by mass or more or 5 parts by mass or less, and 0.5 parts by mass or more or 3 parts by mass or less, based on 100 parts by mass of the (meth) acrylic copolymer. It is particularly preferable to include it in a proportion. However, this range may be exceeded in balance with other factors.
The photopolymerization initiator may be used alone or in combination of two or more.

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, etc. Various additives such as synthetic resins, glass fibers and glass beads can also be appropriately blended.

(Layer structure and thickness of adhesive layer)
The adhesive layer may be a single layer or a plurality of layers such as two layers and three layers.
Further, the adhesive layer may have a base material layer (a layer having no adhesiveness) as a core layer, and a layer made of an adhesive material may be laminated on both sides of the base material layer. .. In the case of such a configuration, it is preferable that the base material layer as the core layer 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-mentioned characteristics regarding loss tangent tan δ (SA), loss tangent tan δ (SB), storage elastic modulus G'(SA) and storage elastic modulus G'(SB). It is preferable to have it.

The thickness of the adhesive layer is not particularly limited. Above all, the range of 20 μm to 500 μm is preferable. Within this range, for example, a thin pressure-sensitive adhesive layer having a thickness of 20 μm can provide a pressure-sensitive adhesive sheet having excellent print step followability. Further, in a thick adhesive material layer having a thickness of 500 μm, the amount corresponding to the printing step is formed in advance, so that it is possible to suppress the overflow of the adhesive material at the time of bonding.
Therefore, the thickness of the pressure-sensitive adhesive layer is preferably 20 μm to 500 μm, more preferably 30 μm or more or 300 μm or less, and more preferably 50 μm or more or 200 μm or less.

<Cover I>
As shown in FIG. 1, the present pressure-sensitive adhesive sheet laminate includes a covering portion I which is peelably laminated on one side of the front and back sides of the pressure-sensitive adhesive layer, for example, the side where unevenness is formed on the surface.

The storage elastic modulus E'(MA) of the covering portion I at 100 ° C. 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 region where the pressure-sensitive adhesive composition is plasticized or flows, the coating portion I can be deformed by sufficiently following the uneven shape, and also on the surface of the pressure-sensitive adhesive layer pressed by the coating portion I during molding. It is possible to mold a desired uneven shape with high accuracy, for example, so that the corners are not rounded.

Conventionally, as a release film to be laminated on an adhesive sheet, a material having a high storage elastic modulus, in other words, a "hard" material has been widely used. This is because the properties required for the release film are mainly the protection of the pressure-sensitive adhesive layer and the releasability. However, according to the study by the present inventors, in a new application in which a release film is laminated on an adhesive sheet and heat-molded, when a new problem of heat-moldability is required, the conventional release is performed. It has been found that the above physical properties of the mold film cannot be achieved. For this reason, as a result of scrutinizing the phenomenon that occurs during heat molding and the characteristics of the adhesive layer, it is better to make the characteristics different from the release film that has been generally used so far, which is a new problem of heat moldability. It was found to be advantageous for solving the problem. In particular, it has been found that the above problems can be solved by controlling the storage elastic modulus at a specific temperature within a specific range.

From this point of view, the storage elastic modulus E'(MA) of the covering portion I at 100 ° C. is preferably 1.0 × 10 ^{6 to} 2.0 × 10 ⁹ Pa, and ^{more than 5.0 × 10 6} Pa or more. It is more preferably 1.0 × 10 ⁹ Pa or less, and ^{more preferably 1.0 × 10 7} Pa or more or 5.0 × 10 ⁸ Pa or less.

Further, the storage elastic modulus E'(MB) of the covering portion I at 30 ° C. is preferably ^{5.0 × 10 7 to} 1.0 × 10 ^{10 Pa.}
If the storage elastic modulus E'(MB) of the covering portion I at 30 ° C. is 5.0 × 10 ^{7 to} 1.0 × 10 ¹⁰ Pa, the shape retention can be maintained under normal conditions, and handling is easy. For example, not only is it easy to peel off, but it is not too hard, so it is possible to prevent unnecessary and unintended irregularities from being formed on the pressure-sensitive adhesive layer.
From this point of view, the storage elastic modulus E'(MB) of the covering portion I at 30 ° C. ^{is preferably 5.0 × 10 7 to} 1.0 × 10 ¹⁰ Pa, and ^{more than 1.0 × 10 8} Pa or more. It is more preferably 8.0 × 10 ⁹ Pa or less, and ^{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 of the coating portion I at 30 ° C. and 100 ° C. 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. of the coating portion I can be adjusted. It can be adjusted by adjusting the conditions of the material and the manufacturing conditions such as the presence or absence of stretching, the molding conditions, and the stretching conditions in the case of stretching. However, the method is not limited to these methods.

Further, 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 above relational expression (1), sufficient moldability can be obtained. It is more preferable because it can be used.
From this point of view, E'(MB) / E'(MA) ≧ 2.0 is preferable, and among them, 30 ≧ E'(MB) / E'(MA) or E'(MB) / E'(MA). ) ≧ 3.0, and among them, 10 ≧ E'(MB) / E'(MA) or E'(MB) / E'(MA) ≧ 5.0 is particularly preferable.

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. It can be adjusted by adjusting the conditions of the material and the manufacturing conditions such as the presence or absence of stretching, the molding conditions, and the stretching conditions in the case of stretching. However, the method is not limited to these methods.

Furthermore, the storage elastic modulus G'(SA) of the pressure-sensitive adhesive layer at 100 ° C. 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

Sufficient moldability if the storage elastic modulus G'(SA) of the pressure-sensitive adhesive layer at 100 ° C. and the storage elastic modulus E'(MA) of the covering portion I at 100 ° C. satisfy the relational expression (2). Is more preferable because it can be obtained.
From this point of view, E'(MA) / G'(SA) is preferably 1.0 × 10 ^{3 to} 1.0 × 10 ^7, with 5.0 × 10 ³ or more or 5.0 × 10 ^{6 among them.} Hereinafter, among them, 1.0 × 10 ⁴ or more or 1.0 × 10 ⁶ or less is particularly preferable.

In order to adjust E'(MA) and G'(SA) so as to have the above-mentioned relationship, the characteristics of the pressure-sensitive 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 of the composition constituting the pressure-sensitive adhesive layer, the gel fraction, the weight average molecular weight, and the like. Further, as the characteristics of the coating portion I, for example, the conditions of the material of the coating 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, and the presence or absence of stretching and molding are performed. It can be adjusted by adjusting the manufacturing conditions such as the conditions and, in the case of stretching, the stretching conditions. However, the method 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 the covering portion I is peeled from the pressure-sensitive 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 pressure-sensitive adhesive layer.
From this point of view, 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. It is more preferably / cm or more or 0.1 N / cm or less.

The covering portion I further heats the pressure-sensitive adhesive sheet laminate at 100 ° C. for 5 minutes and then cools it to 30 ° C., and the peeling force F (D) when peeling the covering portion I from the pressure-sensitive adhesive layer in an atmosphere of 30 ° C. Is preferably 0.2 N / cm or less.
If the peeling force F (D) obtained by heating the pressure-sensitive adhesive sheet laminate at 100 ° C. for 5 minutes and then cooling it to 30 ° C. and measuring in an atmosphere of 30 ° C. is about the same as the peeling force F (C). Since the peeling force F (D) does not change even if the pressure-sensitive adhesive sheet laminate is heat-molded, the coating portion I can be easily peeled off from the pressure-sensitive adhesive layer.
From this point of view, 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. It is more preferably / cm or more or 0.1 N / cm or less.

Further, it is preferable that 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 in the covering portion I.
The difference between the peeling force F (D) obtained by heating the pressure-sensitive adhesive sheet laminate at 100 ° C. for 5 minutes and then cooling it to 30 ° C. in an atmosphere of 30 ° C. and the peeling force F (C) under normal conditions. 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 coating portion I can be easily peeled off from the pressure-sensitive adhesive layer. can.
From this point of view, 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, particularly 0.08 N / cm or less, and among them 0.05 N / cm. The following is more preferable.

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

As a configuration example of the covering portion I, a configuration example including a covering base material layer and a release layer can be mentioned. By laminating the release layer on one side of the coating base material layer, the coating portion I can be configured so as to be easily peeled off from the pressure-sensitive adhesive layer.

At this time, the coated base material layer is a stretched or non-stretched layer containing, for example, one kind of resin selected from the group consisting of polyester, copolymerized polyester, polyolefin and copolymerized polyolefin as a main component or two or more kinds of resins. That is, it is preferably a single layer or a plurality of layers including a layer made of a stretched or unstretched film containing these resins as a main component.

Above all, the coating base material layer constituting the coating portion I is a stretched or unstretched film containing, for example, a copolymerized polyester, a polyolefin, or a copolymerized polyolefin as a main component from the viewpoint of mechanical strength, chemical resistance, and the like. It is preferably a single layer or a plurality of layers including a layer composed of.
Specific examples of the copolymerized polyester include copolymerized polyethylene terephthalate obtained by optionally copolymerizing isophthalic acid as a dicarboxylic acid, cyclohexanedimethanol as a diol, 1,4-butanediol, diethylene glycol and the like. 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 as well as a release agent such as silicone.
Here, examples of the modified olefin constituting the release layer include an unsaturated carboxylic acid or an anhydride thereof, or a resin containing a polyolefin modified with a silane coupling agent as a main component.

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 a monoepoxy compound of a derivative thereof and the acid. Examples include the ester compound of the above, a reaction product of an acid with a polymer having a group capable of reacting with these acids in the molecule, and the like. Moreover, these metal salts can also be used. Of these, maleic anhydride is more preferably used. In addition, these copolymers can be used alone or in admixture of two or more.

In order to produce the modified polyolefin resin, for example, these modified monomers can be copolymerized at the stage of prepolymerizing the polymer, or these modified monomers can be graft-copolymerized with the polymer once polymerized. Further, as the modified polyolefin resin, these modified monomers are 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. It is preferably in the range of 5% by mass or less, preferably 4.5% by mass or less, and more preferably 4.0% by mass or less. Of these, graft-modified ones are preferably used.

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

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

<Cover II>
As described above, in the present adhesive sheet laminate, the covering portion I is laminated on one side of the front and back sides of the pressure-sensitive adhesive layer so as to be peelable, and the coating portion I can be peeled off on the opposite side of the coating portion I, that is, on the front and back sides of the pressure-sensitive adhesive material layer. It can be configured by laminating the covering portions II. In this way, the handling property can be improved by laminating the covering portion II on the front and back sides of the adhesive layer so that it can be peeled off. However, it is also possible to have a configuration in which the covering portion II is not laminated.

The material and composition of the covering portion II are not particularly limited as long as they are laminated on the front and back sides of the pressure-sensitive adhesive layer so as to be peelable.

The covering portion II may have, for example, the same laminated structure and material as the covering portion I, and may have the same thickness as the covering portion I or a different thickness.
If the covering portion II has the same laminated structure and material as the covering portion I, it is possible to prevent warpage from occurring when the present pressure-sensitive 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 their ratios (E'(MB) / E'. (MA)), peeling force F (C), peeling 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 a material different from those of the covering portion I.
For the covering portion II, for example, a commonly used release film (also referred to as “release film”) can be used. Specific examples thereof include materials having a storage elastic modulus E'(MC) at 100 ° C. of 2.0 × 10 ^{9 to} 1.0 × 10 ¹¹ Pa, for example, a biaxially stretched polyethylene terephthalate (PET) film. Etc. can be used.

(Manufacturing method of this adhesive sheet laminate)
As an example of the method for producing the present pressure-sensitive adhesive sheet laminate, for example, a method in which a pressure-sensitive adhesive composition is sandwiched between two covering portions I or II and a laminator is used to form a pressure-sensitive adhesive layer can be mentioned. Further, as another method, a method of applying the pressure-sensitive adhesive composition to the covering portion I or II to form the pressure-sensitive adhesive layer can be mentioned. However, the present invention is not limited to such a 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.

[Laminate of this shaped adhesive sheet]
Using the present adhesive sheet laminate, a shaped adhesive sheet laminate 1 (referred to as "the present shaped adhesive sheet laminate 1") having an uneven shape formed on the surface of the adhesive layer is produced as follows. Can be done.

As shown in FIG. 3, the present-form adhesive sheet laminate 1 has an adhesive layer 2, a covering portion I which is detachably laminated on one side of the front and back of the adhesive layer 2, and the adhesive layer 2. It is equipped with a covering part II that is peelably laminated on the other side of the front and back of the
The adhesive layer 2 has 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 adhesive sheet 2, and the front and back one-side surface 3A is provided with a concave portion, a convex portion, or an uneven portion (referred to as “covered portion surface uneven portion 3B”). , The back surface 3C of the sheet is provided with a convex portion, a concave portion, or an uneven portion (referred to as "protective sheet back surface uneven portion 3D") that matches the uneven portion 2B on the front surface of the adhesive sheet, in other words, forms an uneven portion to be fitted.
The covering portion II may be provided with a configuration including a flat surface along the front and back surfaces 2C of the pressure-sensitive adhesive sheet 2.

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

As shown in FIG. 2, the modified pressure-sensitive adhesive sheet laminate 1 having such a configuration is obtained by press-molding, vacuum forming, vacuum forming, or roll-forming the main pressure-sensitive adhesive sheet laminate. It can be manufactured by integrally shaping the uneven shape with respect to the body.
By manufacturing in this way, the adhesive sheet surface uneven portion 2B of the adhesive layer 2, the protective sheet surface uneven portion 3B of the covering portion I, and the protective sheet back surface uneven portion 3D form irregularities corresponding to the same portions, respectively. Can be.

The adhesive layer 2 can be used, for example, as a double-sided adhesive sheet for bonding two image display device constituent members (also referred to as "adhesive bodies") constituting the image display device.
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 an uneven portion (“adhesive surface uneven portion”) on the bonded surface (also referred to as “bonded surface”) of the adherend. It can be preferably formed into the same contour shape so as to match (referred to as). Therefore, the pressure-sensitive adhesive sheet surface uneven portion 2B in the present shaped pressure-sensitive adhesive sheet laminated body 1 can be fitted to the adherend surface uneven portion in the image display device constituent member as the adherend.

Here, as the image display device, for example, a smartphone or tablet provided with a liquid crystal display device (LCD), an organic EL display device (OLED), an electronic paper, a micro electromechanical system (MEMS) display, a plasma display (PDP), or the like. Examples include terminals, mobile phones, televisions, game machines, personal computers, car navigation systems, ATMs, fish finder, and the like. However, it is not limited to these.
The image display device constituent member as an adherend is a member constituting these image display devices, and examples thereof include a surface protection panel, a touch panel, an image display panel, and the like. Reference numeral 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 the surface protection panel and the touch panel, or the touch panel and the image display panel. However, the adherend is not limited to these.

<Manufacturing method>
Here, the details of the manufacturing method of the present shaped pressure-sensitive adhesive sheet laminated body 1 will be described.

As described above, as shown in FIG. 2, the present adhesive sheet laminate is manufactured by heating and molding the present adhesive sheet laminate 1 to integrally form an uneven shape with respect to the present adhesive sheet laminate 1. Can be done.
At this time, as the molding processing method, for example, press molding, vacuum forming, compressed air forming, shaping by roll, shaping by lamination and the like can be mentioned. Of these, press molding is particularly preferable from the viewpoint of moldability and processability.

A more detailed concrete example will be described.
The adhesive sheet laminate was preheated with a heater, and when the temperature reached a predetermined temperature, the adhesive sheet laminate was transported to a press forming machine, and the uneven shape corresponding to the printed step shape of the adherend was previously formed. By pressing and cooling with a mold, it is possible to transfer the mold shape to one side of the present pressure-sensitive adhesive sheet laminate and manufacture the present-type shaped pressure-sensitive adhesive sheet laminate 1 having unevenness shaped on one side. ..

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

The material of the mold used for the unevenness shaping is not particularly limited. For example, resin-based materials such as silicone resin and fluororesin, metal-based materials such as stainless steel and aluminum, and the like can be mentioned. Of these, a metal-based mold capable of controlling the temperature during molding is particularly preferable because high-precision moldability is required for shaping the unevenness of the adherend.
Further, the cooling after the press working may be performed after the die is opened, or the die may be cooled and cooled at the same time as the press.

In the present invention, the conditions related to molding such as press pressure and press time are not particularly specified, and may be appropriately adjusted depending on the dimensions and shape to be molded, the material to be used, and the like.
Further, after the molding process, it may be cut using a Thomson blade, a rotary blade or the like.

<Use>
Here, an example of the usage of the present shaped adhesive sheet laminated body 1 will be described.
In recent years, as mobile phones, smartphones, tablet terminals, and the like have become more popular, there are many cases in which the image display unit is damaged due to accidental dropping by the user. In particular, when the image display device is of the touch panel type, not only the display becomes difficult to see due to damage, but also the touch panel operation itself becomes impossible due to physical obstacles or water intrusion, or it may cause a failure. Therefore, repair, that is, repair may be performed in which only the image display unit is replaced.
In the repair of the image display device, the adhesive sheet is also used when loading a new image display unit. Normally, repairs are often performed manually by repair workers, which requires the skill of repair workers. That is, if you are not an expert, when you load the image display unit via the adhesive sheet, air may enter inside or the adhesive material may squeeze out.
On the other hand, if the present shaped pressure-sensitive adhesive sheet laminate 1 is used, a highly accurate step shape or the like can be given in advance. Therefore, for example, a step shape corresponding to the model of the image display device is given to the pressure-sensitive adhesive layer in advance. By doing so, the repair work is greatly simplified, and it becomes possible to carry out the repair work without requiring the skill of a repair worker. As described above, the pressure-sensitive adhesive sheet laminate of the present invention can be usefully used for repairing an image display device.

<Explanation of words and phrases>
When expressed as "X to Y" (X and Y are arbitrary numbers) in the present specification, they mean "X or more and Y or less" and "preferably larger than X" or "preferably Y". It also includes the meaning of "smaller".
Further, when expressed as "X or more" (X is an arbitrary number) or "Y or less" (Y is an arbitrary number), it means "preferably larger than X" or "preferably less than Y". Intention is also included.

In the present invention, the boundary between the sheet and the film is not fixed, and it is not necessary to distinguish between the two in the present invention. Therefore, in the present invention, even if the term "film" is used, the "sheet" is included and the "sheet" is used. Even if it is referred to as "film", it shall be included.

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

<Measurement and evaluation method>
First, a method for measuring and evaluating various physical property values of the samples obtained in Examples and Comparative Examples will be described.

(Elastic modulus of the covering part)
The covering portions A to D used in the examples and comparative examples are cut out to a length of 50 mm and a width of 4 mm, respectively, and the distance between chucks is 25 mm and 1 using a dynamic viscoelastic device (DVA-200, IT Measurement Control Co., Ltd.). It was measured with a strain of%. The measurement was performed under the conditions that the measurement temperature range was −50 ° C. to 150 ° C., the frequency was 1 Hz, and the temperature rising rate was 3 ° C./min. The value of the storage elastic modulus at 100 ° C. of the obtained data was defined as E'(MA), and the value of the storage elastic modulus at 30 ° C. was defined as E'(MB).

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

(Gel fraction)
As for the gel content of the adhesive layer, about 0.05 g of each of the adhesive layers obtained in Examples and Comparative Examples was collected and wrapped in a bag shape with a SUS mesh (# 200) whose mass (X) was measured in advance. After closing the mouth of the bag and measuring the mass (Y) of this package, soak it in 100 ml of ethyl acetate and store it in the dark at 23 ° C for 24 hours, then remove the package and 4.5 at 70 ° C. After heating for a time to evaporate the adhered ethyl acetate, the mass (Z) of the dried package was measured, and the obtained mass was substituted into the following formula to obtain the result.
Gel fraction [%] = [(ZX) / (YX)] x 100

(Moldability)
In order to confirm the moldability, the molding tests of Examples and Comparative Examples were carried out using the mold described below. That is, as shown in FIG. 5, one of the upper and lower molds for molding is a convex mold 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. It was an aluminum flat plate having a width of 170 mm and a thickness of 40 mm.
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 are provided with four rectangular (length 89 mm, width 58 mm) molding recesses in a plan view.

The covering portions A to D of the shaped adhesive sheet laminate having irregularities formed by the methods described in Examples and Comparative Examples are peeled off to form a concave portion corresponding to a printing step and a convex portion corresponding to a display surface. The height of each was measured by a non-contact method 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 100 μm of the mold, and select the one with a transfer rate of 50% or more and the one with a transfer rate of less than 50% derived from the following formula. Each was evaluated as ×.
Transfer rate (%) = h (mold height) / 100 (mold depth) x 100

(Peeling force)
The pressure-sensitive adhesive sheet laminates produced in Examples and Comparative Examples were cut into pieces having a length of 150 mm and a width of 50 mm, and a 180 ° peeling test was performed on the interface between the covering portions A to D and the pressure-sensitive adhesive layer at a test speed of 300 mm / min.
The peeling force in an environment of 30 ° C. was F (C), and the peeling force after heating at 100 ° C. for 5 minutes and then naturally cooling to 30 ° C. was F (D). The peeling force of.

<Cover I>
The following covering portions A to D were used as the covering portion I of the pressure-sensitive adhesive sheet laminates in Examples and Comparative Examples. The values of each storage modulus are shown in Table 1.

-Coating part A: A film formed by laminating a release layer (thickness: 2 μm) made of a silicone compound on one side of a biaxially stretched isophthalic acid copolymer PET film (thickness: 75 μm).
Cover B: A film formed 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.
-Coating portion C: A film made of a polyolefin film (thickness: 70 μm) made of unstretched polypropylene.
Cover D: A film formed 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>
(Making a double-sided adhesive sheet)
As the (meth) acrylic copolymer (a), 15 parts by mass (18 mol%) of polymethylmethacrylate macromonomer (Tg: 105 ° C.) and butyl acrylate (Tg: −55 ° C.) 81 parts by mass having a number average molecular weight of 2400. 1 kg of an acrylic copolymer (a-1) (weight average molecular weight 230,000) formed by random copolymerization of (75 mol%) and 4 parts by mass (7 mol%) of acrylic acid (Tg: 106 ° C.), and a cross-linking agent. As (b), 90 g of glycerin dimethacrylate (manufactured by Nichiyu Co., Ltd., product name: GMR) (b-1), and as the photopolymerization initiator (c), 2,4,6-trimethylbenzophenone and 4-methylbenzophenone. A resin composition 1 to be used for the pressure-sensitive adhesive layer was prepared by uniformly mixing 15 g of the mixture (manufactured by Lamberti, product name: Ezacure TZT) (c-1). The glass transition temperature of the obtained resin composition was −5 ° C.

The obtained resin composition 1 is sandwiched between a PET film (manufactured by Mitsubishi Plastics Co., Ltd., product name: Diafoil MRV-V06, thickness: 100 μm) and a covering portion A, and a laminator is used. The resin composition 1 was shaped into a sheet so that the thickness was 100 μm, and the pressure-sensitive adhesive sheet laminate 1 was prepared. The release layer side of the covering portion A was arranged so as to be in contact with the resin composition 1.

The obtained pressure-sensitive adhesive sheet laminate 1 was thermoformed by the following process using a vacuum compressed air molding machine (FKS-0632-20 type) to prepare a shaped pressure-sensitive adhesive sheet laminate 1. ..
That is, using 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, under the condition of a mold clamping pressure of 8 MPa. Press molding was performed for a second to prepare a shaped pressure-sensitive adhesive sheet laminate 1 having irregularities shaped on the surface.

<Example 2>
The pressure-sensitive adhesive sheet laminate 2 and the shaped pressure-sensitive adhesive sheet laminate 2 were produced in the same manner as in Example 1 except that the coating portion B was used instead of the coating portion A.

<Example 3>
The pressure-sensitive adhesive sheet laminate 3 and the shaped pressure-sensitive adhesive sheet laminate 3 were produced in the same manner as in Example 1 except that the coating portion C was used instead of the coating portion A.

<Comparative Example 1>
The pressure-sensitive adhesive sheet laminate 4 and the shaped pressure-sensitive adhesive sheet laminate 4 were produced in the same manner as in Example 1 except that the coating portion D was used instead of the coating portion A.

Table 1 shows 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.

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 portion having a storage elastic modulus E'(MA) of 0 × 10 ¹⁰ Pa and a storage elastic modulus E ′ (MA) at 100 ° C. of 1.0 × 10 ^{6 to} 2.0 × 10 ⁹ Pa is laminated on the pressure-sensitive adhesive layer for molding. By doing so, it was confirmed that the uneven shape can be formed on the adhesive layer with high accuracy.
On the other hand, as shown in Comparative Example 1, when a general wide biaxially oriented homopolymer PET film used as a release film, since storage modulus even covering portion in a high temperature range exceeding 2.0 × 10 9 ^Pa Even if thermoforming was performed, sufficient unevenness could not be formed on the pressure-sensitive 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 well-shaped textured pressure-sensitive adhesive sheet can be obtained by laminating a covering portion having a size of 0 × 10 ^{6 to} 2.0 × 10 ^{9 Pa on an pressure-sensitive adhesive layer and performing molding.}

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

Therefore, by using the adhesive sheet laminate as described above to accurately shape the unevenness corresponding to the printing step of the image display device as the adherend, printing can be performed without a gap between the adherend and the adherend. It is possible to confirm that it is possible to manufacture a shaped adhesive sheet laminate for an image display device that can be adhered and adhered well without the adhesive material overflowing even in an adherend having a narrow frame design. did it.

Regarding the peeling force, the heating and cooling conditions when the peeling force F (D) is measured, that is, the conditions of heating at 100 ° C. for 5 minutes and then naturally cooling to 30 ° C., produce a shaped adhesive sheet laminate. This is a typical heating and cooling condition. In all of the above examples, 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. 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 provided with the pressure-sensitive adhesive layer and the covering portion I formed by stacking the pressure-sensitive adhesive layer on one side of the pressure-sensitive adhesive layer so as to be peelable.
The loss tangent tan δ (SA) of the pressure-sensitive adhesive layer at 100 ° C. is 1.0 or more, and the loss tangent tan δ (SB) of the pressure-sensitive adhesive layer at 30 ° C. is less than 1.0.
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 ′ (MA) of the covering portion I at 30 ° C. MB) is an adhesive sheet laminate having a value of 5.0 × 10 ^{7 to} 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 pressure-sensitive adhesive sheet laminate according to claim 1 or 2, wherein the gel content of the pressure-sensitive adhesive layer is 20% or less. The storage elastic modulus G'(SA) of the pressure-sensitive adhesive layer at 100 ° C. is ^{less than 1.0 × 10 4} Pa, and the storage elastic modulus G'(SB) of the pressure-sensitive adhesive layer at 30 ° C. is 1.0. × 10 The pressure-sensitive adhesive sheet laminate according to any one of claims 1 to 3, which is ^{4 Pa or more.} The storage elastic modulus E'(MA) of the covering portion I at 100 ° C. and the storage elastic modulus G'(SA) of the pressure-sensitive adhesive layer at 100 ° C. 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 coated base material layer has a stretched or unstretched layer containing one kind of resin selected from the group consisting of polyester, copolymerized polyester, polyolefin and copolymerized polyolefin as a main component or two or more kinds of resins. 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) when peeling the covering portion I from the pressure-sensitive adhesive layer in an atmosphere of 30 ° C. is 0.2 N / cm or less.
(II) The adhesive sheet laminate is heated at 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 adhesive material layer in an atmosphere of 30 ° C. is 0.2 N. It is less than / cm.
(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 claim is characterized in that the pressure-sensitive adhesive layer is formed of a resin composition containing a (meth) acrylic copolymer (a), a cross-linking agent (b) and a photopolymerization initiator (c). Item 2. The pressure-sensitive adhesive sheet laminate according to any one of Items 1 to 7. A shaped adhesive sheet laminate using the adhesive sheet laminate according to any one of claims 1 to 8.
The adhesive layer is provided with concave portions, convex portions or uneven portions (referred to as "adhesive layer surface uneven portions") on one side surface of the front and back surfaces, and
The covering portion I is in close contact with the front and back one-side surfaces of the pressure-sensitive adhesive layer, has concave portions, convex portions or uneven portions (referred to as “covered surface uneven portions”) on the front and back one-side surfaces, and the front and back surfaces are one. A shaped adhesive sheet provided with a convex portion, a concave portion, or an uneven portion (referred to as "covered portion back surface unevenness") having irregularities corresponding to the adhesive material layer surface uneven portion on the front and back other side surfaces on the opposite side to the side. Laminate. The adhesive layer is a double-sided adhesive sheet for adhering two adherends together.
The adhesive layer surface uneven portion is characterized in that it coincides with a concave portion, a convex portion, or an uneven portion (referred to as “adhesive surface uneven portion”) on the adherend surface of any of the adherends. The shaped adhesive sheet laminate according to claim 9. The shaped adhesive sheet laminate according to claim 10, wherein any of the adherends is selected from the group consisting of a surface protection panel, a touch panel, and an image display panel. The pressure-sensitive adhesive sheet laminate according to any one of claims 1 to 8 is heated to form an uneven shape on at least one surface of the pressure-sensitive adhesive sheet by press molding, vacuum forming, vacuum forming or roll molding. A method for manufacturing a laminated body of a shape adhesive sheet.

Images