CN113462311A - Adhesive sheet laminate, shaped adhesive sheet laminate, and method for producing same - Google Patents

Abstract

The application provides an adhesive sheet laminate, a shaped adhesive sheet laminate and a method for manufacturing the same. A pressure-sensitive adhesive sheet laminate characterized by comprising a pressure-sensitive adhesive material layer and a cover section I formed by laminating the pressure-sensitive adhesive material layer on one surface thereof in a peelable manner, wherein the pressure-sensitive adhesive sheet laminate is a novel pressure-sensitive adhesive sheet laminate capable of forming an uneven shape conforming to an uneven portion on the surface of an adherend with high surface accuracy, and the cover section I has a storage modulus E' (MA) at 100 ℃ of 1.0 x 10⁶～2.0×10⁹Pa, and the storage modulus E' (MB) at 30 ℃ of the cover part I is 5.0X 10⁷～1.0×10¹⁰Pa。

Description

Adhesive sheet laminate, shaped adhesive sheet laminate, and method for producing same

The present application is a divisional application filed on 2017, 9/6, application No. 201780056747.0 entitled "adhesive sheet laminate, shaped adhesive sheet laminate, and method for producing the same".

Technical Field

The present invention relates to a shaped adhesive sheet laminate which 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, a writing tablet, and the like, and to an adhesive sheet laminate which is suitable for forming a shaped adhesive sheet laminate.

Background

In general, a touch panel type image display device is configured by combining a surface protection panel, a touch panel, and an image display panel (collectively, also referred to as "configuration member for an image display device").

In recent years, a surface protection panel for a touch panel type image display device such as a smartphone or a tablet terminal is printed in black on the peripheral edge portion other than the visible opening surface portion, using a plastic material such as an acrylic resin plate or a polycarbonate plate in addition to tempered glass.

In addition, the Touch panel is formed by using a plastic film sensor together with a glass sensor, a Touch On Lens (TOL) member integrated with a surface protection panel by using a Touch panel function, or an On-cell or In-cell member integrated with an image display panel by using a Touch panel function.

In such an image display device, in order to further improve image visibility, a structure in which a gap between the respective image display device constituent members is filled with a transparent resin such as a liquid adhesive, a thermoplastic adhesive sheet, or an adhesive sheet is a general structure.

In addition, in the field of image display devices centered on mobile phones and mobile terminals, in addition to thinning and high precision, diversification of design is advanced, and conventionally, a black concealing portion is generally printed in a frame shape on a peripheral edge portion of a surface protective panel. When the concealing portion is formed in a color other than black, the concealing property is low, and therefore the height of the concealing portion, that is, the printed portion tends to be higher than that of black. Therefore, the adhesive sheet for bonding the constituent members having such a printed portion is required to fill each corner following a large print height difference.

Therefore, various methods for burying the printing step have been proposed.

For example, patent document 1 discloses, as a novel double-sided adhesive sheet for an image display device that can be bonded in an adhesive state without a gap on a surface to be bonded of the adhesive sheet even if the surface to be bonded has a level difference due to printing or the like, a double-sided adhesive sheet for an image display device for bonding 2 arbitrary adherends selected from a surface protective panel, a touch panel, and an image display panel, wherein at least one adherend has a level difference portion on the surface to be bonded of the adhesive sheet, and the double-sided adhesive sheet is formed in a shape of a bonding surface to be bonded to the surface to be bonded along a surface shape of the surface to be bonded.

Patent document 2 discloses a method for producing a double-sided adhesive sheet for an image display device, wherein the double-sided adhesive sheet before bonding is shaped into the same surface shape as the uneven shape of the bonding surface of the adherend using an adhesive composition having a gel fraction of less than 40%, in relation to a method for producing a double-sided adhesive sheet for bonding two adherends selected from a surface protection panel, a touch panel and an image display panel.

Documents of the prior art

Patent document

Patent document 1: WO 2014/073316A 1

Patent document 2: WO 2015/174392A 1

Disclosure of Invention

Problems to be solved by the invention

In recent years, in the field of image display devices such as mobile phones and mobile terminals, thinning and high precision are further required, and it is required that uneven portions on the surface of an adherend such as a print level difference can be filled with an adhesive sheet for bonding image display device constituent members with high precision, and that the adhesive material does not overflow to the outside. As a countermeasure, 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.

In order to form the surface shape of the pressure-sensitive adhesive sheet along the surface shape of the adherend in advance as described above, a method of forming an uneven shape conforming to the uneven portion on the surface of the adherend by press molding a pressure-sensitive adhesive sheet laminate in which release sheets are laminated on both sides of the pressure-sensitive adhesive sheet is assumed.

However, as a result of actually attempting to implement the above method using a psa sheet laminate in which a normal release sheet is laminated on both sides of a psa sheet, the following problems become apparent: it is difficult to form a concavo-convex shape conforming to the concavo-convex portion on the surface of the adherend with high accuracy on the surface of the pressure-sensitive adhesive sheet.

The present invention relates to a psa sheet laminate comprising a psa layer and a cover part formed by laminating the psa layer on one side in a peelable manner, and proposes a novel psa sheet laminate capable of forming a concavo-convex shape conforming to the concavo-convex shape of the surface of an adherend on the surface of the psa layer with high accuracy, and a shaped psa sheet laminate using the psa sheet laminate.

Means for solving the problems

The invention provides a pressure-sensitive adhesive sheet laminate comprising a pressure-sensitive adhesive layer and a cover section I laminated on one surface of the pressure-sensitive adhesive layer in a peelable manner, wherein the cover section I has a storage modulus E' (MA) at 100 ℃ of 1.0 x 10⁶～2.0×10⁹Pa, and the storage modulus E' (MB) at 30 ℃ of the cover part I is 5.0X 10⁷～1.0×10¹⁰Pa。

The present invention also provides a shaped adhesive sheet laminate using the adhesive sheet laminate, wherein the adhesive material layer has concave or convex portions or concave-convex portions (referred to as "adhesive material layer surface concave-convex portions") on the front and back surfaces, the coating portion I is in close contact with the front and back surfaces of the adhesive material layer, has concave or convex portions or concave-convex portions (referred to as "coating portion surface concave-convex portions") on the front and back surfaces, and has convex or concave portions or convex-concave portions (referred to as "coating portion back surface convex-concave portions") on the front and back surfaces opposite to the front and back surfaces, on which concave-convex portions or concave-convex portions corresponding to the adhesive material layer surface concave-convex portions are formed.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the pressure-sensitive adhesive sheet laminate proposed by the present invention, for example, after the pressure-sensitive adhesive sheet laminate is heated, the coating portion I is molded by pressing a mold, whereby the uneven shape conforming to the uneven portion on the surface of the adherend can be formed on the surface of the pressure-sensitive adhesive material layer with high accuracy. Further, since the covering section I can maintain the shape retention property in a normal state, it is not only easy to handle but also not excessively hard, and thus it is possible to suppress unnecessary undesired unevenness from being imparted to the adhesive material layer.

The shaped adhesive sheet laminate of the present invention comprises an adhesive sheet surface uneven portion on the front and back surfaces of an adhesive material layer, wherein the coating section I is in close contact with the front and back surfaces of the adhesive material layer, the coating section surface uneven portion is provided on the front and back surfaces, and the coating section back surface uneven portion is provided on the front and back surfaces opposite to the front and back surfaces. As described above, the shaped adhesive sheet laminate according to the present invention includes: the covering section I is configured to be closely attached to the front and back surfaces of the adhesive material layer without a gap, and the covering section I is configured to be detachably laminated on the front and back surfaces of the adhesive material layer, so that it is possible to prevent dust and the like from adhering to the surface of the adhesive material layer and reducing the adhesive force, and it is also possible to prevent the uneven shape of the surface of the adhesive material layer formed on the front and back surfaces of the adhesive material layer from absorbing moisture in the air and collapsing, or to prevent dust and the like from adhering to the surface and reducing the adhesive force.

Drawings

Fig. 1 is a cross-sectional view schematically showing an example of an adhesive sheet laminate as an embodiment of the present invention.

Fig. 2 is a sectional view for explaining an example of a pressing step in producing a shaped adhesive sheet laminate using an example of an adhesive sheet laminate according to an embodiment of the present invention.

Fig. 3 is a schematic view showing an example of a shaped adhesive sheet laminate according to an embodiment of the present invention, wherein (a) is a sectional view and (B) is a perspective view.

Fig. 4 is a graph showing the viscoelasticity curve of the material used for the adhesive sheet laminate produced in example/comparative example.

Fig. 5 is a perspective view showing one of the molds used in the example/comparative example.

Detailed Description

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

[ adhesive sheet laminate ]

As shown in fig. 1, a psa sheet laminate (referred to as "the psa sheet laminate") according to an embodiment of the present invention includes a psa layer, a cover section I formed by laminating the psa layer so as to be peelable from one of the front and back sides, and a cover section II formed by laminating the psa layer so as to be peelable from the other of the front and back sides. Here, the covering section II is optional, and a structure in which the covering section II is not laminated may be adopted.

< adhesive Material layer >

The adhesive material layer of the adhesive sheet laminate may be a hot-melt layer that can function as a double-sided adhesive sheet when the cover section I and the cover section II are peeled off, and that softens or melts when heated.

The adhesive material layer preferably has a loss tangent tan δ (SA) at 100 ℃ of 1.0 or more. Further, the loss tangent tan δ (SB) at 30 ℃ is preferably less than 1.0.

Here, the loss tangent tan δ means a ratio (G "/G ') of the loss modulus G ″ to the storage modulus G'.

Since the temperature at the time of thermoforming the adhesive sheet laminate is usually 70 to 120 ℃, if the loss tangent tan δ (SA) at 100 ℃ is 1.0 or more, the uneven shape is easily formed on the surface of the adhesive material layer.

Further, when the loss tangent tan δ (SB) at 30 ℃ of the pressure-sensitive adhesive material layer is less than 1.0, the shape can be maintained in a normal state, and therefore, a state in which an uneven shape conforming to the uneven portion on the surface of the adherend can be formed on the surface of the pressure-sensitive adhesive material layer with high accuracy can be maintained.

Generally, 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 larger the value, the stronger the viscous property. On the other hand, the loss tangent tan δ is less than 1.0, and the smaller the value becomes, the stronger the elastic property becomes. Therefore, by controlling the loss tangent tan δ of the adhesive material layer at different temperatures, both formability and shape retention can be achieved.

From the above-mentioned viewpoint, the loss tangent tan δ (SA) at 100 ℃ of the adhesive material layer is preferably 1.0 or more, more preferably 1.5 or more or 30 or less, particularly 3.0 or more or 20 or less.

On the other hand, the adhesive material layer preferably has a loss tangent tan δ (SB) at 30 ℃ of less than 1.0, of which 0.01 or more or 0.9 or less, particularly 0.1 or more or 0.8 or less is preferable.

Here, the loss tangent tan δ (SA) at 100 ℃ and the loss tangent tan δ (SB) at 30 ℃ of the adhesive material layer can be adjusted to the above ranges by adjusting the components of the composition constituting the adhesive material layer, the gel fraction, the weight average molecular weight, and the like.

Further, the storage modulus G' (SA) at 100 ℃ of the adhesive material layer is preferably less than 1.0X 10⁴Pa. In addition, the storage modulus G' (SB) at 30 ℃ of the adhesive material layer is preferably 1.0X 10⁴Pa or above.

The adhesive material layer has a storage modulus G' (SA) at 100 ℃ of less than 1.0X 10⁴Pa, since sufficient moldability can be obtained, the storage modulus G' (SB) at 30 ℃ of the pressure-sensitive adhesive material layer is preferably 1.0X 10⁴Pa or more is preferable from the viewpoint of shape stability after molding.

From the above viewpoint, the storage modulus G' (SA) at 100 ℃ of the adhesive material layer is preferably less than 1.0X 10⁴Pa, among them, 5.0X 10 is further preferred¹Pa or more or 5.0X 10³Pa or less, especially 1.0X 10²Pa or more or 1.0X 10³Pa or less.

From the above, the storage modulus G' (SA) at 100 ℃ of the adhesive material layer is more preferably 5.0X 10¹Pa is not less than 1.0X 10⁴Pa, or 5.0X 10¹Pa or more and 5.0X 10³Pa or less, among them, 1.0X 10 is more preferable²Pa is not less than 1.0X 10⁴Pa, or 1.0X 10²Pa or more and 5.0X 10³Pa or less, most preferably 1.0X 10²Pa or more and 1.0X 10³Pa or less.

From the above viewpoint, the storage modulus G' (SB) of the adhesive material layer at 30 ℃ is preferably 1.0 as a reference10⁴Pa or more, among them, 2.0X 10 is more preferable⁴Pa or more or 1.0X 10⁷Pa or less, particularly 5.0X 10⁴Pa or more or 1.0X 10⁶Pa or less.

Further, from the above, the storage modulus G' (SB) at 30 ℃ of the adhesive material layer is more preferably 1.0X 10⁴Pa or more and 1.0X 10⁷Pa or less, or 1.0X 10⁴Pa or more and 1.0X 10⁶Pa or less, among them, 2.0X 10 is more preferable⁴Pa or more and 1.0X 10⁷Pa or less, or 2.0X 10⁴Pa or more and 1.0X 10⁶Pa or less, most preferably 5.0X 10⁴Pa or more and 1.0X 10⁶Pa or less.

Here, the storage modulus G '(SA) at 100 ℃ of the adhesive material layer and the storage modulus G' (SB) at 30 ℃ of the adhesive material layer can be adjusted to the above ranges by adjusting the components of the composition constituting the adhesive material layer, the gel fraction, the weight average molecular weight, and the like.

The temperature at which the loss tangent tan δ of the adhesive material layer becomes 1.0 is preferably 50 to 150 ℃, more preferably 60 ℃ or more or 130 ℃ or less, particularly 70 ℃ or more or 110 ℃ or less.

When the temperature at which the loss tangent tan delta of the adhesive material layer becomes 1.0 is 50 to 150 ℃, the adhesive sheet laminate can be molded by heating the adhesive sheet laminate to 50 to 150 ℃.

The glass transition temperature (Tg) of the base resin of the adhesive material layer is preferably-50 to 40 ℃, and more preferably-30 ℃ or higher or 25 ℃ or lower, particularly-10 ℃ or higher or 20 ℃ or lower. Here, the measurement of the glass transition temperature refers to the midpoint between inflection points of the baseline shift when the temperature is raised at a rate of 3 ℃/min using a Differential Scanning Calorimeter (DSC).

When the glass transition temperature (Tg) of the base resin of the adhesive material layer is in the above range, adhesiveness can be provided to the adhesive material layer, and the temperature at which the loss tangent tan δ of the adhesive material layer becomes 1.0 can be adjusted to 50 to 150 ℃.

As the material of the adhesive material layer, any conventionally known adhesive sheet can be used as long as it can be adjusted to a predetermined viscoelastic behavior.

For example, there may be mentioned:

1) an adhesive sheet formed by using a (meth) acrylate polymer (hereinafter referred to as "acrylate (co) polymer" including copolymers) as a base resin, and blending a crosslinking monomer, a crosslinking initiator, a reaction catalyst, and the like as needed to perform a crosslinking reaction;

2) a pressure-sensitive adhesive sheet formed by using a butadiene or isoprene copolymer as a base resin and blending a crosslinking monomer, a crosslinking initiator if necessary, a reaction catalyst, and the like therein to perform a crosslinking reaction;

3) a pressure-sensitive adhesive sheet formed by using a silicone polymer as a base resin and blending a crosslinking monomer, and if necessary, a crosslinking initiator, a reaction catalyst, and the like to perform a crosslinking reaction;

4) polyurethane-based pressure-sensitive adhesive sheets using a polyurethane-based polymer as a base resin.

The physical properties of the adhesive material layer itself are not a substantial problem in the present invention, other than the viscoelastic properties and thermal properties described above. However, the material of the above 1) which uses an acrylate-based (co) polymer as a base resin is preferable from the viewpoints of adhesiveness, transparency, weather resistance, and the like.

When properties such as electrical characteristics and a low refractive index are required, the material of 2) above, which uses a butadiene or isoprene copolymer as a base resin, is preferable.

When heat resistance, rubber elasticity in a wide temperature range, and other properties are required, the silicone-based polymer of the above 3) is preferably used as the base resin.

When performance such as removability is required, the polyurethane polymer of the above 4) is preferably used as the base resin.

As an example of the adhesive material layer, an adhesive sheet formed of a resin composition containing a (meth) acrylic copolymer (a) as a base resin, a crosslinking agent (b), and a photopolymerization initiator (c) can be exemplified.

In this case, the viscoelastic properties must be satisfied in an uncrosslinked state, i.e., in a state before the 3-dimensional crosslinked network structure is formed. From this viewpoint, the gel fraction of the adhesive material layer is preferably 40% or less.

When the gel fraction of the adhesive material layer is 40% or less, the bonding of the molecular chains constituting the adhesive material layer to each other is suppressed within an appropriate range, and therefore, the adhesive material layer can have appropriate fluidity when molded into a shaped adhesive sheet laminate.

From the above viewpoint, the gel fraction of the pressure-sensitive adhesive layer is preferably 40% or less, particularly preferably 20% or less, 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 fraction of the adhesive material layer is not limited to the case of using a resin composition containing a (meth) acrylic copolymer (a) as a base resin, a crosslinking agent (b), and a photopolymerization initiator (c), and the same applies to the case of using another resin composition as an adhesive material layer.

((meth) acrylic copolymer (a))

The (meth) acrylic copolymer (a) can be appropriately adjusted in properties such as glass transition temperature (Tg) according to the kind and composition ratio of the acrylic monomer and the methacrylic monomer to be polymerized, and the polymerization conditions.

Examples of the acrylic monomer and the methacrylic monomer used for polymerizing the acrylic 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, acrylonitrile, methacrylonitrile, fluorine-containing acrylate, silicone acrylate, and the like obtained by copolymerizing a hydrophilic group, an organic functional group, and the like with these may also be used.

Among the acrylate polymers, alkyl ester (meth) acrylate copolymers are particularly preferred.

The alkyl acrylate or methacrylate component, which is the (meth) acrylate for forming the alkyl ester (meth) acrylate copolymer, is preferably 1 or a mixture of 2 or more selected from alkyl acrylates or alkyl methacrylates in which the alkyl group is any of n-octyl, isooctyl, 2-ethylhexyl, n-butyl, isobutyl, methyl, ethyl, and isopropyl.

As the other component, 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, the (meth) acrylate copolymer polymer can be obtained by heating and polymerizing a monomer component, which is an appropriate combination of the alkyl (meth) acrylate component and the (meth) acrylate component having an organic functional group, as a starting material.

Among them, 1 kind of alkyl acrylate such as isooctyl acrylate, n-octyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, or a mixture of 2 or more kinds selected from them, or a copolymer obtained by copolymerizing at least 1 or more kinds selected from isooctyl acrylate, n-octyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and the like with acrylic acid is preferable.

As the polymerization treatment using these monomers, known polymerization methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization can be used, and in this case, a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator is used according to the polymerization method, whereby an acrylate copolymer can be obtained.

(acrylic copolymer (A1))

An example of a preferable base polymer of the adhesive material layer is a (meth) acrylic copolymer (a1) formed of a graft copolymer having a macromonomer as a branch component.

When the adhesive material layer is formed using the acrylic copolymer (a1) as a base resin, the adhesive material layer can maintain a sheet shape at room temperature and exhibit self-adhesiveness, has a hot-melt property that melts or flows when heated in an uncrosslinked state, can be further photocured, and can be bonded by exhibiting excellent cohesive force after photocuring.

Therefore, when the acrylic copolymer (a1) is used as the base polymer of the adhesive material layer, it exhibits adhesiveness at room temperature (20 ℃) even in an uncrosslinked state, and has the property of softening or fluidizing when heated to a temperature of 50 to 100 ℃, more preferably 60 ℃ or higher or 90 ℃ or lower.

The glass transition temperature of the copolymer constituting the main component of the acrylic copolymer (A1) is preferably-70 to 0 ℃.

In this case, the glass transition temperature of the copolymer component constituting the main component means the glass transition temperature of a polymer obtained by copolymerizing only the monomer component constituting the main component of the acrylic copolymer (a 1). Specifically, the value is calculated from the glass transition temperature and the composition ratio of a polymer obtained from a homopolymer of each component of the copolymer and a calculation formula of Fox.

The formula for Fox is a calculation value obtained by the following formula, and can be obtained using a value described in Polymer HandBook [ Polymer handboot, j.

1/(273+Tg)＝Σ(Wi/(273+Tgi))

[ in the formula, Wi represents the weight fraction of the monomer i, and Tgi represents the Tg (. degree. C.) of the homopolymer of the monomer i. ]

Since the glass transition temperature of the copolymer component constituting the main component of the acrylic copolymer (a1) affects the flexibility of the pressure-sensitive adhesive layer in a room temperature state and the wettability of the pressure-sensitive adhesive layer to an adherend, that is, the adhesiveness, the glass transition temperature of the pressure-sensitive adhesive layer is preferably-70 ℃ to 0 ℃, and particularly preferably-65 ℃ or more or-5 ℃ or less, and particularly-60 ℃ or more or-10 ℃ or less, in order to obtain a suitable adhesiveness (tackiness) in a room temperature state.

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, the molecular weight of the copolymer component can be reduced to further soften it.

Examples of the (meth) acrylate 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, tert-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, tert-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, and the like, 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, and the like. Of these, hydroxyl-containing (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and glycerol (meth) acrylate, hydroxyl-containing (meth) acrylic acid, 2- (meth) acryloyloxyethylhexahydrophthalate, 2- (meth) acryloyloxypropylhexahydrophthalate, 2- (meth) acryloyloxyethylphthalate, 2- (meth) acryloyloxypropylphthalate, 2- (meth) acryloyloxyethylmaleate, 2- (meth) acryloyloxypropylmaleate, 2- (meth) acryloyloxyethylsuccinate, 2- (meth) acryloyloxypropylsuccinate, hydroxy-containing (meth) acrylate having a hydrophilic group or an organic functional group, hydroxy-containing (meth) acrylate having a hydroxyl group or a hydroxyl group, hydroxy-containing (meth) acrylate having a hydrophilic group or an organic functional group, hydroxy-containing a hydroxyl group, 2- (meth) acryloyloxyethylhexahydrophthalate, 2- (meth) acryloyloxypropyl phthalate, 2- (meth) acryloyloxypropyl maleate, 2- (meth) acryloyloxyethylhexahydrophthalate, 2- (meth) acryloyloxyethylphthalate, 2- (meth) acryloyloxypropyl-phthalate, 2- (meth) acryloyloxyethyl phthalate, 2-acryloyloxyethyl phthalate, 2-or (meth) acrylate having a hydroxyl group, or a, Carboxyl group-containing monomers such as crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, monomethyl itaconate, etc., anhydride group-containing monomers such as maleic anhydride, itaconic anhydride, etc., glycidyl (meth) acrylate, glycidyl α -ethyl acrylate, epoxy group-containing monomers such as 3, 4-epoxybutyl (meth) acrylate, amino group-containing monomers such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, etc., (meth) acrylamide, N-t-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, diacetone acrylamide, maleic amide, maleimide, etc., amide group-containing monomers such as vinylpyrrolidone, pyrrolidone, ethylene glycol, propylene glycol, and propylene glycol, and propylene glycol, Basic monomers of heterocyclic ring systems such as vinylpyridine and vinylcarbazole.

In addition, various vinyl monomers such as styrene, t-butylstyrene, α -methylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, alkyl vinyl ether, hydroxyalkyl vinyl ether, and alkyl vinyl monomer copolymerizable with the above acrylic monomer and methacrylic monomer can also be suitably used.

The main component of the acrylic copolymer (a1) preferably contains a hydrophobic (meth) acrylate monomer and a hydrophilic (meth) acrylate monomer as structural units.

Since the tendency of whitening due to moist heat is observed when the main component of the acrylic copolymer (a1) is composed of only a hydrophobic monomer, it is preferable to introduce a hydrophilic monomer into the main component to prevent whitening due to moist heat.

Specifically, as the main component of the acrylic copolymer (a1), there can be mentioned a copolymer component obtained by random copolymerization of a hydrophobic (meth) acrylate monomer, a hydrophilic (meth) acrylate monomer and a polymerizable functional group at the terminal of a macromonomer.

Examples of the hydrophobic (meth) acrylate monomer include n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-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, tert-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, and mixtures thereof, Isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and methyl methacrylate.

Further, as the hydrophobic vinyl monomer, there can be mentioned: vinyl acetate, styrene, t-butyl styrene, alpha-methyl styrene, vinyl toluene, alkyl vinyl monomers, and the like.

Examples of the hydrophilic (meth) acrylate monomer include: hydroxyl group-containing (meth) acrylates such as methyl acrylate, meth (acrylic acid), tetrahydrofurfuryl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and glycerol (meth) acrylate; carboxyl group-containing monomers such as (meth) acrylic acid, 2- (meth) acryloyloxyethylhexahydrophthalate, 2- (meth) acryloyloxypropylhexahydrophthalate, 2- (meth) acryloyloxyethylphthalate, 2- (meth) acryloyloxypropylphthalate, 2- (meth) acryloyloxyethylmaleate, 2- (meth) acryloyloxypropylmaleate, 2- (meth) acryloyloxyethylsuccinate, 2- (meth) acryloyloxypropylsuccinate, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, monomethyl itaconate, and acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; epoxy group-containing monomers such as glycidyl (meth) acrylate, glycidyl α -ethacrylate, 3, 4-epoxybutyl (meth) acrylate and the like; alkoxy polyalkylene glycol (meth) acrylates such as methoxypolyethylene glycol (meth) acrylate; n, N-dimethylacrylamide, hydroxyethylacrylamide, and the like.

In the acrylic copolymer (A1), it is preferable that the graft component of the graft copolymer contains a repeating unit derived from a macromonomer into which a macromonomer is introduced.

The macromonomer is a high molecular monomer having a polymerizable functional group at the end 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 aforementioned acrylic copolymer (a 1).

Specifically, the glass transition temperature (Tg) of the macromonomer affects the heating melting temperature (hot melt temperature) of the adhesive material layer 2, and therefore the glass transition temperature (Tg) of the macromonomer is preferably 30 ℃ to 120 ℃, more preferably 40 ℃ or more or 110 ℃ or less, particularly 50 ℃ or more or 100 ℃ or less.

When the glass transition temperature (Tg) is adjusted as described above, it is possible to maintain excellent processability and storage stability by adjusting the molecular weight, and it is possible to adjust the glass transition temperature so that hot melting occurs at around 80 ℃.

The glass transition temperature of the macromonomer is the glass transition temperature of the macromonomer itself and can be measured by a Differential Scanning Calorimeter (DSC).

In addition, it is also preferable to adjust the molecular weight and content of the macromonomer in order to maintain the state of physical crosslinking as a binder composition by allowing the branch components to attract each other at room temperature and to obtain fluidity by heating to an appropriate temperature to release the physical crosslinking.

From the above viewpoint, the macromonomer is preferably contained in the acrylic copolymer (a1) at a ratio of 5 to 30% by mass, and among them, 6 to 25% by mass, and particularly 8 to 20% by mass are preferable.

In addition, the number average molecular weight of the macromonomer is preferably 500 or more and less than 8000, among them preferably 800 or more or less than 7500, particularly 1000 or more or less than 7000.

As the macromonomer, conventionally produced one (for example, macromonomer manufactured by Toyo Synthesis Co., Ltd.) can be used.

The high molecular weight backbone 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, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-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, tert-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, isopropyl (meth) acrylate, hexyl (ethyl (meth) acrylate, hexyl (ethyl acrylate, hexyl (meth) acrylate, hexyl (ethyl (meth) acrylate, hexyl (ethyl (methyl (ethyl acrylate, hexyl (meth) acrylate, hexyl (ethyl acrylate, hexyl (meth) acrylate, hexyl (ethyl acrylate, hexyl (, 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, (meth) acrylate monomers such as benzyl (meth) acrylate, hydroxyalkyl (meth) acrylate, (meth) acrylic acid, glycidyl (meth) acrylate, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, (meth) acrylonitrile, alkoxyalkyl (meth) acrylate, and alkoxy polyalkylene glycol (meth) acrylate; styrene, tert-butyl styrene, alpha-methyl styrene, vinyl toluene, alkyl vinyl monomer, vinyl acetate, alkyl vinyl ether, hydroxy alkyl vinyl ether and various vinyl monomers, these can be used alone or more than 2 kinds combined.

Examples of the terminal-overlapping functional group of the macromonomer include: methacryloyl, acryloyl, vinyl, and the like.

(crosslinking agent (b))

As the crosslinking agent (b), a crosslinking monomer used in crosslinking the acrylate polymer can be used. Examples of the crosslinking agent include crosslinking agents having at least 1 crosslinkable functional group selected from a (meth) acryloyl group, an epoxy group, an isocyanate group, a carboxyl group, a hydroxyl group, a carbodiimide group, an oxazoline group, an aziridine group, a vinyl group, an amino group, an imino group, and an amide group, and 1 kind or 2 or more kinds may be used in combination.

The crosslinkable functional group may be protected with a protecting group capable of deprotection.

Among them, it is preferable to use: a polyfunctional (meth) acrylate having 2 or more (meth) acryloyl groups; a polyfunctional organic functional group resin having 2 or more organic functional groups such as an isocyanate group, an epoxy group, a melamine group, a glycol group, a siloxane group, and an amino group; an organometallic compound having a metal complex such as zinc, aluminum, sodium, zirconium or calcium.

Examples of the polyfunctional (meth) acrylate include 1, 4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerol glycidyl ether di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, 1, 9-nonanediol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, bisphenol A polyethoxy di (meth) acrylate, bisphenol A polyalkoxy di (meth) acrylate, bisphenol F polyalkoxy di (meth) acrylate, polyalkylene glycol di (meth) acrylate, trimethylolpropane triethoxy ethyl (meth) acrylate, epsilon-caprolactone-modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, and mixtures thereof, Pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, propoxylated 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) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, di (meth) acrylate of the epsilon-caprolactone adduct of hydroxypivalic acid neopentyl glycol, mixtures thereof, and mixtures thereof, Ultraviolet-curable polyfunctional monomers such as trimethylolpropane tri (meth) acrylate, alkoxylated trimethylolpropane tri (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate, and polyfunctional acrylic oligomers such as polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate and polyether (meth) acrylate.

Among the above-mentioned examples, from the viewpoint of improving the adhesion to an adherend and the effect of suppressing whitening by moist heat, among the above-mentioned polyfunctional (meth) acrylate monomers, polyfunctional monomers or oligomers containing a polar functional group such as a hydroxyl group, a carboxyl group, or an amide group are preferable. Among them, polyfunctional (meth) acrylates having a hydroxyl group or an amide group are preferably used.

From the viewpoint of preventing moist heat whitening, it is preferable that the main component of the (meth) acrylate copolymer, for example, the graft copolymer, contains a hydrophobic acrylate monomer and a hydrophilic acrylate monomer, and further, it is preferable to use a polyfunctional (meth) acrylate having a hydroxyl group as the crosslinking agent.

In addition, a monofunctional or polyfunctional (meth) acrylate which reacts with a crosslinking agent may be further added for adjusting the effects of adhesion, moist heat resistance, heat resistance and the like.

The content of the crosslinking agent is preferably 0.1 to 20 parts by mass, particularly preferably 0.5 part by mass or more and 15 parts by mass or less, particularly preferably 1 part by mass or more and 13 parts by mass or less, based on 100 parts by mass of the (meth) acrylic copolymer, from the viewpoint of balancing flexibility and cohesion as an adhesive composition.

(photopolymerization initiator (c))

When the acrylic ester polymer is crosslinked, it is effective to add a crosslinking initiator (a peroxidation initiator or a photopolymerization initiator) and a reaction catalyst (a tertiary amine compound, a quaternary ammonium compound, a tin laurate compound, or the like) as appropriate.

When crosslinking is performed by ultraviolet irradiation, the photopolymerization initiator (c) is preferably blended.

The photopolymerization initiators (c) are roughly classified into two types according to the radical generation mechanism, and roughly classified into: a cleavage type photopolymerization initiator capable of generating a radical by breaking and decomposing a single bond of the photopolymerization initiator itself; and a hydrogen abstraction type photopolymerization initiator in which a photo-excited initiator forms an excited state complex with a hydrogen donor in the system and hydrogen of the hydrogen donor can be transferred.

Among them, the cleavage type photopolymerization initiator decomposes to form other compounds when radicals are generated by light irradiation, and loses its function as a reaction initiator when excited. Therefore, when a cleavage type is used as the photopolymerization initiator having an absorption wavelength in the visible light region, it is preferable to use a hydrogen abstraction type because the photopolymerization initiator reactive to light remains as an unreacted residue in the adhesive composition after crosslinking the adhesive sheet by irradiation with light, which results in unexpected temporal change of the adhesive sheet and less possibility of acceleration of crosslinking. Further, regarding the coloring peculiar to the photopolymerization initiator, a substance which is formed into a reaction decomposition product and is thereby eliminated or discolored in the visible light region may be appropriately selected, and therefore, such a substance is preferable.

On the other hand, when the radical generating reaction is performed by irradiation with active energy rays such as ultraviolet rays, the hydrogen abstraction-type photopolymerization initiator does not generate a decomposition product such as a cleavage-type photopolymerization initiator, and therefore, it is difficult to form a volatile component after the reaction is completed, and damage to an adherend 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-propan-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) & lt/EN & gt, Methyl phenylglyoxylate, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinopropan-1-one, 2- (dimethylamino) -2- [ (4-methylphenyl) methyl ] -1- [4- (4-morpholino) 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, derivatives thereof, and the like.

Among them, from the viewpoint of being a cleavage type photopolymerization initiator and discoloring as a decomposition product after the reaction, acylphosphine oxide-based photoinitiators such as bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide, 2,4, 6-trimethylbenzoyl diphenylphosphine oxide, (2,4, 6-trimethylbenzoyl) ethoxyphenylphosphine oxide, bis (2, 6-dimethoxybenzoyl) 2,4, 4-trimethylpentylphosphine oxide and the like are preferable.

Further, from the viewpoint of suitability for an acrylic copolymer containing a graft copolymer having a macromonomer as a branching component, 2,4, 6-trimethylbenzoyl diphenylphosphine oxide, (2,4, 6-trimethylbenzoyl) ethoxyphenylphosphine oxide, bis (2, 6-dimethoxybenzoyl) 2,4, 4-trimethylpentylphosphine oxide, and the like are preferably used as a photopolymerization initiator.

The content of the photopolymerization initiator is not particularly limited. For example, it is particularly preferably contained in a proportion of 0.1 to 10 parts by mass, particularly 0.2 part by mass or more and 5 parts by mass or less, particularly 0.5 part by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the (meth) acrylic copolymer. However, the range may be out of this range in view of balance with other elements.

The photopolymerization initiator may be used in 1 kind or 2 or more kinds in combination.

In addition to the above components, various additives such as pigments having near infrared absorption properties, dyes such as dyes, tackifiers, antioxidants, moisture absorbents, ultraviolet absorbers, silane coupling agents, resins of natural products and synthetic products, glass fibers, and glass beads may be appropriately blended as necessary.

(layer Structure and thickness of adhesive Material layer)

The adhesive material layer may be a single layer, or may be a plurality of layers such as two or three layers.

The adhesive material layer may have a core layer of a base material layer (a layer having no adhesiveness) and layers of an adhesive material may be laminated on both sides of the base material layer. In the case of such a configuration, the base layer as the core layer preferably has such material and characteristics that the adhesive sheet laminate can be heat molded. The adhesive material layer other than the base material layer preferably has the above properties with respect to loss tangent tan δ (SA), loss tangent tan δ (SB), storage modulus G '(SA), and storage modulus G' (SB).

The thickness of the adhesive material layer is not particularly limited. Among them, the range of 20 μm to 500 μm is preferable. When the thickness is in this range, for example, when the thickness is a thin adhesive material layer such as 20 μm, an adhesive sheet having excellent print level difference following properties can be provided. In the case of a thick adhesive material layer having a thickness of 500 μm, the overflow of the adhesive material during the bonding can be suppressed by shaping the portion corresponding to the printing height difference in advance.

Therefore, the thickness of the adhesive material layer is preferably 20 μm to 500 μm, more preferably 30 μm or more or 300 μm or less, particularly 50 μm or more or 200 μm or less.

< cover I >

As shown in fig. 1, the adhesive sheet laminate includes a cover section I formed by laminating adhesive material layers in a peelable manner on the front and back sides, for example, on the side having irregularities formed on the surface.

The storage modulus E' (MA) of the cover I at 100 ℃ is preferably 1.0X 10⁶～2.0×10⁹Pa。

The temperature at which the adhesive sheet laminate is heat-molded is usually 70 to 120 ℃ and therefore the storage modulus E' (MA) at 100 ℃ is 1.0X 10⁶～2.0×10⁹Pa, in a temperature range in which the adhesive composition plasticizes or flows, not only can the covering part I sufficiently follow the uneven shape to deform, but also the adhesive material layer pressed by the covering part I can be molded with high surface accuracy at the time of molding, for example, desired depressions can be molded without rounding the cornersA convex shape.

Conventionally, as a release film to be laminated on an adhesive sheet, a material having a high storage modulus, in other words, "hard" has been used in many cases. This is because the properties required for the release film are mainly the protection and releasability of the adhesive material layer. However, according to the study of the present inventors, it was found that: in a new application in which thermoforming is performed with a release film laminated on a pressure-sensitive adhesive sheet, when a new problem such as thermoformability is required, the above-described physical properties of the conventional release film cannot be achieved. Therefore, it has been found that it is advantageous to solve a new problem of thermoformability to have properties different from those of release films generally used so far, as a result of examining the phenomenon occurring at the time of thermoforming, the properties of the adhesive material layer, and the like. In particular, the above problem can be solved by controlling the storage modulus at a specific temperature to a specific range.

From the above viewpoint, the storage modulus E' (MA) at 100 ℃ of the covering section I is preferably 1.0X 10⁶～2.0×10⁹Pa, among them, 5.0X 10 is further preferred⁶Pa or more or 1.0X 10⁹Pa or less, especially 1.0X 10⁷Pa or more or 5.0X 10⁸Pa or less.

From the above, the storage modulus E' (MA) at 100 ℃ of the covering section I is more preferably 1.0X 10⁶～1.0×10⁹Pa, or 1.0X 10⁶～5.0×10⁸Pa, among them, 5.0X 10 is more preferable⁶～2.0×10⁹Pa, or 5.0X 10⁶～1.0×10⁹Pa, most preferably 1.0X 10⁷～1.0×10⁹Pa, or 1.0X 10⁷～5.0×10⁸Pa。

The storage modulus E' (MB) at 30 ℃ of the covering section I is preferably 5.0X 10⁷～1.0×10¹⁰Pa。

The storage modulus E' (MB) at 30 ℃ of the cover I is 5.0X 10⁷～1.0×10¹⁰Pa, since the shape-retaining property can be maintained in a normal state, handling is easy, and for example, the pressure-sensitive adhesive layer can be prevented from being unnecessarily given an unnecessary peeling force, since the pressure-sensitive adhesive layer is not excessively hardUndesired irregularities.

From the above viewpoint, the storage modulus E' (MB) at 30 ℃ of the covering section I is preferably 5.0X 10⁷～1.0×10¹⁰Pa, among them, 1.0X 10 is more preferable⁸Pa or more or 8.0X 10⁹Pa or less, especially 1.0X 10⁹Pa or more or 5.0X 10⁹Pa or less.

From the above, the storage modulus E' (MB) at 30 ℃ of the covering section I is more preferably 5.0X 10⁷～8.0×10⁹Pa, or 5.0X 10⁷～5.0×10⁹Pa, among them, 1.0X 10 is more preferable⁸Pa～1.0×10¹⁰Pa, or 1.0X 10⁸Pa～8.0×10⁹Pa, most preferably 1.0X 10⁹～8.0×10⁹Pa, or 1.0X 10⁹～5.0×10⁹Pa。

In order to adjust the storage modulus of the coated part I at 30 ℃ and 100 ℃ as described above, the storage modulus can be adjusted by adjusting the conditions of the material of the coated part I, such as the type of the base resin, the component of the copolymer resin, the weight average molecular weight, the glass transition temperature, and the crystallinity, and by adjusting the production conditions such as the presence or absence of stretching, the molding conditions, and the stretching conditions during stretching. However, the method is not limited to these methods.

Further, the storage modulus E '(MA) at 100 ℃ of the covering section I and the storage modulus E' (MB) at 30 ℃ of the covering section I preferably satisfy the following relational expression (1).

(1)··E’(MB)/E’(MA)≥2.0

It is more preferable that the storage modulus E '(MA) at 100 ℃ of the covering part I and the storage modulus E' (MB) at 30 ℃ of the covering part I satisfy the relational expression (1) because sufficient moldability can be obtained.

From the above-mentioned viewpoint, E '(MB)/E' (MA) ≥ 2.0 is preferable, and among them, 30 ≥ E '(MB)/E' (MA) or E '(MB)/E' (MA) ≥ 3.0 is more preferable, and 10 ≥ E '(MB)/E' (MA) or E '(MB)/E' (MA) ≥ 5.0 is particularly preferable.

In order to adjust E '(MB) and E' (MA) so as to satisfy the above relationship, for example, the conditions of the material of the covering section 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, and the production conditions such as the presence or absence of stretching, the molding conditions, and the stretching conditions during stretching can be adjusted. However, the method is not limited to these methods.

Further, the storage modulus G '(SA) at 100 ℃ of the adhesive material layer and the storage modulus E' (MA) at 100 ℃ of the covering portion I preferably satisfy the following relational expression (2).

(2)··1.0×10³≤E’(MA)/G’(SA)≤1.0×10⁷

It is more preferable that the storage modulus G '(SA) at 100 ℃ of the adhesive material layer and the storage modulus E' (MA) at 100 ℃ of the covering section I satisfy the relational expression (2) because sufficient moldability can be obtained.

From the above viewpoint, E '(MA)/G' (SA) is preferably 1.0X 10³～1.0×10⁷Among them, 5.0X 10 is particularly preferable³Above or 5.0 × 10⁶The following, in particular 1.0X 10⁴Above or 1.0X 10⁶The following.

From the above, E '(MA)/G' (SA) is more preferably 1.0 × 10³～5.0×10⁶Or 1.0X 10³～1.0×10⁶More preferably 5.0X 10³～5.0×10⁶Or 5.0X 10³～1.0×10⁶Most preferably 1.0X 10⁴～5.0×10⁶Or 1.0X 10⁴～1.0×10⁶。

In order to adjust E '(MA) and G' (SA) so as to satisfy the above relationship, the properties of the adhesive material layer or the covering portion I may be adjusted. The properties of the adhesive material layer can be achieved by adjusting, for example, the components of the composition constituting the adhesive material layer, the gel fraction, the weight average molecular weight, and the like. The properties of the covering section I can be adjusted by adjusting the conditions of the material of the covering section 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, and adjusting the production conditions such as the presence or absence of stretching, the molding conditions, and the stretching conditions during stretching. However, the method is not limited to these methods.

The cover (I) preferably has a peeling force (F) (C) of 0.2N/cm or less when peeled from the adhesive material layer in an atmosphere at 30 ℃.

When the peeling force F (C) is 0.2N/cm or less, the covering section I can be easily peeled from the adhesive material layer.

From the above viewpoint, the peeling force F (C) is preferably 0.2N/cm or less, more preferably 0.01N/cm or more or 0.15N/cm or less, particularly 0.02N/cm or more or 0.1N/cm or less.

The cover I is also preferably: the peeling force F (D) when the cover part I is peeled from the adhesive material layer in an atmosphere of 30 ℃ is 0.2N/cm or less after heating the adhesive sheet laminate at 100 ℃ for 5 minutes and then cooling to 30 ℃.

When the pressure-sensitive adhesive sheet laminate is heated at 100 ℃ for 5 minutes and then cooled to 30 ℃ and the peel force f (d) measured in an atmosphere at 30 ℃ is about the same as the peel force f (c), the peel force f (d) does not change even when the pressure-sensitive adhesive sheet laminate is heat-molded, and therefore the cover section I can be easily peeled from the pressure-sensitive adhesive material layer.

From the above viewpoint, the peeling force F (D) is preferably 0.2N/cm or less, more preferably 0.01N/cm or more or 0.15N/cm or less, particularly 0.02N/cm or more or 0.1N/cm or less.

The absolute value of the difference between the peeling force F (C) and the peeling force F (D) is preferably 0.1N/cm or less.

When the absolute value of the difference between the peeling force f (d) obtained by heating the adhesive sheet laminate at 100 ℃ for 5 minutes and then cooling the adhesive sheet laminate to 30 ℃ in an atmosphere at 30 ℃ and the peeling force f (c) in a normal state measured at 30 ℃ is 0.1N/cm or less, the peeling force f (d) does not change even when the adhesive sheet laminate is heat-molded, and therefore the cover section I can be easily peeled from the adhesive material layer.

From the above viewpoint, the absolute value of the difference between the peeling force F (C) and the peeling force F (D) is preferably 0.1N/cm or less, more preferably 0.08N/cm or less, particularly preferably 0.05N/cm or less.

The peeling force f (c) and the peeling force f (d) of the covering portion I can be adjusted by the type of the release layer formed on one side of the covering portion I, and the like. However, the method is not limited thereto.

As an example of the configuration of the covering section I, there is a configuration including a covering base layer and a releasing layer. By laminating a release layer on one surface of the cover base layer, the cover section I can be configured so as not to be easily peeled from the adhesive material layer.

In this case, the cover base layer preferably includes, for example, a single layer or a plurality of layers of: a stretched or unstretched layer mainly composed of 1 resin or 2 or more resins selected from the group consisting of polyesters, copolyesters, polyolefins, and copolymerized polyolefins, that is, a layer formed of a stretched or unstretched film mainly composed of these resins.

Among them, from the viewpoint of mechanical strength, chemical resistance, and the like, the cover base layer constituting the cover section I is preferably a single layer or a plurality of layers including a layer formed of a stretched or unstretched film containing a copolyester, a polyolefin, or a copolymerized polyolefin as a main component.

Specific examples of the copolyester 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.

Specific examples of the polyolefin include an α -olefin homopolymer, such as a propylene homopolymer and a homopolymer of 4-methylpentene-1.

Specific examples of the polyolefin copolymer include copolymers of 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 a resin containing, as a main component, a polyolefin modified with an unsaturated carboxylic acid or an anhydride thereof, or a silane-based coupling agent.

Examples of the unsaturated carboxylic acid or anhydride thereof include a monoepoxy compound of acrylic acid, methacrylic acid, maleic anhydride, citraconic acid, citraconic anhydride, itaconic acid, itaconic anhydride, or a derivative thereof, an ester compound of the acid, a reaction product of a polymer having a group reactive with the acid in the molecule, and an acid. In addition, metal salts thereof may also be used. Among them, maleic anhydride is more preferably used. These copolymers may be used alone or in combination of 2 or more.

For producing the modified polyolefin-based resin, for example, these modifying monomers may be copolymerized in advance at the stage of polymerizing the polymer, or these modifying monomers may be graft-copolymerized to the temporarily polymerized polymer. Further, as the modified polyolefin-based resin, a plurality of these modifying monomers are used alone or in combination, and a resin having a content of 0.1% by mass or more, preferably 0.3% by mass or more, more preferably 0.5% by mass or more, 5% by mass or less, preferably 4.5% by mass or less, and more preferably 4.0% by mass or less can be suitably used. Among them, a resin subjected to graft modification can be suitably used.

Preferred examples of the modified polyolefin resin include maleic anhydride-modified polypropylene resins, maleic anhydride-modified polyethylene resins, and maleic anhydride ethylene-vinyl acetate copolymers.

From the viewpoint of moldability, the thickness of the covering section I is preferably from 10 μm to 500. mu.m, and among them, from 20 μm to 300 μm, particularly from 30 μm to 150 μm.

< covering section II >

As described above, the present adhesive sheet laminate may be configured as follows: the adhesive layer has a structure in which a covering section I is laminated so as to be peelable on one of the front and back surfaces of the adhesive layer, and a covering section II is laminated so as to be peelable on the other of the front and back surfaces of the adhesive layer, which is the opposite side of the covering section I. In this way, the covering section II is laminated so as to be peelable on the other of the front and back surfaces of the adhesive material layer, whereby the workability can be improved. However, the covering section II may not be laminated.

The material and the structure of the covering section II are not particularly limited as long as the covering section II is formed by laminating the adhesive material layers so as to be peelable from each other on the front and back surfaces thereof.

The covering section II may be formed of the same laminate structure and material as the covering section I, and in this case, may be formed of the same thickness as the covering section I or a different thickness.

When the cover section II is made of the same laminate structure and material as those of the cover section I, the present adhesive sheet laminate can be prevented from warping when heated.

The covering section II may have the same configuration as the covering section I, and may have a different configuration from the covering section I, such as a storage modulus E '(MA) at 100 ℃, a storage modulus E' (MB) at 30 ℃, a ratio thereof (E '(MB)/E' (MA)), a peeling force f (c), and a peeling force f (d).

Further, the covering section II may have a different laminate structure and material from those of the covering section I.

For the covering section II, for example, a commonly used release film (also referred to as "release film") may be used. Specifically, the storage modulus E' (MA) at 100 ℃ is 2.0X 10⁹～1.0×10¹¹For example, a biaxially stretched polyethylene terephthalate (PET) film or the like can be used as the material Pa.

[ covering section I ]

As an example of the configuration of the covering section I, a coated film (referred to as "the present coated film") characterized in that a coated layer is provided on one surface of a copolyester film and the storage modulus E' at 100 ℃ is 1.5X 10⁹Pa or less.

When the present coating film is used, for example, the pressure-sensitive adhesive sheet laminate is heated and then molded by pressing the coating film provided with the coating layer having releasability against a mold, whereby an uneven shape conforming to the uneven portion on the surface of the adherend can be formed on the surface of the pressure-sensitive adhesive sheet with high accuracy. Further, since the coating film can maintain the shape retention property in a normal state, the coating film is not only easy to handle but also not too hard, and thus it is possible to suppress unnecessary undesired irregularities from being imparted to the pressure-sensitive adhesive sheet.

< copolyester film >

The copolyester film constituting the coating film may be a single layer or a laminate, and may be, for example, 4 or more layers other than 2 or 3 layers, as long as the effect of the present invention is not exceeded, and is not particularly limited. For example, when the composition is 3 layers (surface layer/intermediate layer/surface layer), one of the surface layer and the intermediate layer, or 2 or more layers may be a copolyester component, and the other layers may be composed of a polyester component containing no copolyester component.

The copolyester film is a film obtained by cooling a molten polyester sheet extruded by an extrusion method and then stretching the sheet as necessary.

The dicarboxylic acid component of the copolyester is preferably terephthalic acid, and may contain, as a copolymerization component, at least one of known dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyletherdicarboxylic acid, cyclohexanedicarboxylic acid, and the like. The diol component is preferably ethylene glycol, and may contain, as a copolymerization component, at least one of known diols such as propylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, 1, 4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, and neopentyl glycol.

Among them, copolymerized polyethylene terephthalate obtained by optionally copolymerizing phthalic acid and isophthalic acid as dicarboxylic acid components, 1, 4-cyclohexanedimethanol as diol components, 1, 4-butanediol, diethylene glycol, and the like is more preferable.

The content of the copolymerizable component is preferably 1 mol% or more and 50 mol% or less, more preferably 3 mol% or more or 40 mol% or less, and further preferably 4 mol% or more or 30 mol% or less. By setting the content of the copolymerization component to 1 mol% or more, a concave shape, a convex shape, or a concave-convex shape can be formed on the surface of the adhesive sheet when the adhesive sheet is laminated. On the other hand, when the content is 50 mol% or less, not only sufficient dimensional stability is obtained, but also generation of wrinkles during processing can be sufficiently suppressed.

The melting point of the copolyester film is preferably set to 260 ℃ or lower, more preferably 200 to 255 ℃. By setting the melting point to 260 ℃ or lower, sufficient strength can be obtained even by heat treatment at a temperature lower than the melting point of the copolyester film in the heat treatment step after stretching.

It is desirable to contain particles in the copolyester film in order to improve the workability of the film. Examples of the particles include inorganic particles such as calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, lithium phosphate, magnesium phosphate, calcium phosphate, lithium fluoride, alumina, silica, and kaolin; organic particles such as acrylic resins and guanamine resins; the precipitated particles are not limited to these examples, and the precipitated particles are formed by granulating the catalyst residue. The particle diameter of these particles and the content of the copolyester film may be determined as appropriate depending on the purpose. The contained particles may be a single component, or 2 or more components may be used simultaneously. In addition, various stabilizers, lubricants, antistatic agents, and the like may be added as appropriate.

The average particle diameter of the particles contained in the copolyester film is preferably 0.1 to 5.0 μm. When the average particle diameter of the particles is less than 0.1. mu.m, the slip property of the film may be insufficient, and the workability may be deteriorated. On the other hand, when the average particle diameter of the particles exceeds 5.0. mu.m, the smoothness of the film surface may be impaired.

The content of the particles contained in the copolyester film is preferably 0.01 to 0.3 wt%. When the content of the particles is less than 0.01 wt%, the slip property of the film may be insufficient, and the workability may be deteriorated. On the other hand, when the content of the particles exceeds 0.3% by weight, smoothness of the film surface may be impaired.

The method for adding the particles to the copolyester film is not particularly limited, and a known method can be used. For example, it may be added at any stage of producing the polyester, and it is preferable to add the polyester in the form of a slurry dispersed in ethylene glycol or the like at the stage of esterification or at the stage before the start of the polycondensation reaction after the end of the transesterification reaction, and to perform the polycondensation reaction. In addition, the following method and the like can be used: a method of blending a slurry of particles dispersed in ethylene glycol, water or the like with a polyester raw material using a kneading extruder having an exhaust port; or a method of blending the dried pellets with a polyester raw material using a kneading extruder; a method for precipitating particles in a polyester production process system.

The intrinsic viscosity of the copolyester is usually 0.40 to 1.10dl/g, preferably 0.45 to 0.90dl/g, and more preferably 0.50 to 0.80 dl/g. When the intrinsic viscosity is less than 0.40dl/g, the mechanical strength of the film tends to be weak, and when the intrinsic viscosity exceeds 1.10dl/g, the melt viscosity becomes high, and an excessive load may be applied to the extruder.

Next, a production example of the copolyester film will be specifically described, but the production example is not limited at all.

First, a method of obtaining an unstretched sheet by cooling and solidifying a molten sheet extruded from a die with a cooling roll using the above-described raw material for copolyester is preferable. In this case, in order to improve the planarity of the sheet, it is necessary to improve the adhesion between the sheet and the rotary cooling drum, and it is preferable to use an electrostatic application method and/or a liquid coating method.

Next, the obtained unstretched sheet is preferably stretched in at least a uniaxial direction, and more preferably biaxially stretched in a biaxial direction. For example, in the case of continuous biaxial stretching as biaxial stretching, the unstretched sheet is stretched in one direction in the machine direction by a roll or tenter type stretching machine. The stretching temperature is usually 70 to 120 ℃, preferably 75 to 110 ℃, and the stretching ratio is usually 2.5 to 7.0 times, preferably 3.0 to 6.0 times. Next, stretching is performed in a direction perpendicular to the stretching direction (mechanical direction) in the first stage. The stretching temperature is usually 70 to 170 ℃ and the stretching ratio is usually 3.0 to 7.0 times, preferably 3.5 to 6.0 times. Then, the film is heat-treated under tension or relaxation of 30% or less at a temperature of 150 to 270 ℃ to obtain a biaxially oriented film. In the biaxial stretching, a method of stretching in one direction in 2 stages or more may be employed. In this case, it is preferable to perform the final stretching ratios in both directions so as to fall within the above ranges.

In addition, simultaneous biaxial stretching may be employed for the production of the copolyester film. The simultaneous biaxial stretching is a method of simultaneously stretching and orienting the unstretched sheet in the machine direction and the width direction while controlling the temperature at usually 70 to 120 ℃, preferably 75 to 110 ℃. The stretch ratio is preferably 4 to 50 times, more preferably 7 to 35 times, and further preferably 10 to 25 times in terms of area ratio. Then, the film is subjected to a heat treatment at a temperature of 150 to 250 ℃ under tension or under relaxation of 30% or less to obtain a biaxially stretched film. As the simultaneous biaxial stretching apparatus using the stretching method, a conventionally known stretching method such as a screw method, a pantograph method, a linear drive method, or the like can be used.

(coating layer)

In the present coated film, it is important to provide a coating layer on at least one side of the copolyester film. The coating layer is not particularly limited, and specific examples thereof include a release layer, an antistatic layer, an oligomer sealing layer, an easy-adhesion layer, and a primer layer. Among these, a release layer is more preferable in producing a pressure-sensitive adhesive sheet laminate obtained by laminating a pressure-sensitive adhesive sheet. In addition, 2 or more kinds of the functional layers described above may be combined.

As a specific example of the coating layer constituting the coating film, a release layer is explained below.

Specific examples of the resin used for the release layer include curable silicone resins, fluorine-based resins, and polyolefin-based resins, and among them, curable silicone resins are preferred. The curable silicone resin may be a type containing a curable silicone resin as a main component, and a modified silicone type obtained by graft polymerization or the like with an organic resin such as a urethane resin, an epoxy resin, an alkyd resin, or the like may be used within a range not to impair the gist of the present invention.

As the type of the curable silicone resin, any curing reaction type such as addition type, condensation type, ultraviolet curing type, electron beam curing type, solvent-free type, and the like can be used. Specific examples thereof include KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-856, X-62-2422, X-62-2461, X-62-1387, X-62-5039, X-62-5040, KNS-3051, X-62-1496, KNS320A, KNS316, X-62-1574A/B, X-62-7052, X-62-7028A/B, X-62-7619 and X-62-7213, all of which are available from shin-Etsu chemical industries; YSR-3022, TPR-6700, TPR-6720, TPR-6721, TPR6500, TPR6501, UV9300, UV9425, XS56-A2775, XS56-A2982, UV9430, TPR6600, TPR6604, TPR6605, manufactured by Momentive Performance Materials; toray Dow Corning Co., Ltd., SRX357, SRX211, SD7220, SD7292, LTC750A, LTC760A, LTC303E, SP7259, BY24-468C, SP7248S, BY24-452, DKQ3-202, DKQ3-203, DKQ3-204, DKQ3-205, DKQ3-210, and the like. Further, a release control agent may be used in combination for adjusting the releasability of the release layer.

The curing conditions for forming the release layer on the copolyester film are not particularly limited. When the release layer is formed by off-line coating, the heat treatment is preferably performed at 120 to 200 ℃ for 3 to 40 seconds, and preferably at 100 to 180 ℃ for 3 to 40 seconds. Further, if necessary, a combination of heat treatment and irradiation with active energy rays such as ultraviolet irradiation may be used. As an energy source for curing by irradiation with active energy rays, a conventionally known apparatus or energy source can be used. From the viewpoint of coatability, the amount of the release layer applied (after drying) is usually 0.005 to 1g/m²Preferably 0.005 to 0.5g/m²More preferably 0.01 to 0.2g/m²And (3) a range. The coating amount (after drying) is less than 0.005g/m²In the case of the coating, stability is poor in terms of coatability, and it is sometimes difficult to obtain a uniform coating film. On the other hand, more than 1g/m²When thick coating is performed, the coating adhesion, curability, and the like of the release layer itself may decrease.

As a method for providing a release layer on the copolyester film, conventionally known coating methods such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, curtain coating, and the like can be used. Regarding the coating method, there are examples described in "coating method" (Omaki original Miyazaki Yong Sunday, published in 1979).

The copolyester film may be subjected to a surface treatment for providing a coating layer, such as corona treatment, plasma treatment, or ultraviolet irradiation treatment.

(coating film)

The thickness of the coating film is usually 9 to 250. mu.m, preferably 12 to 125. mu.m, and more preferably 25 to 75 μm.

When the thickness is less than 9 μm, the film tension may be insufficient, and defects such as wrinkles may be easily introduced during slitting. On the other hand, if it exceeds 250 μm, the following property to a molded article having a curved surface shape may be insufficient.

The storage modulus E' of the coating film at 100 ℃ is 1.5X 10⁹Pa or less, preferably 1.0X 10⁹Pa or less. By making the storage modulus E' 1.5X 10⁹Pa or less, when laminated with the pressure-sensitive adhesive sheet, can form a concave shape, a convex shape, or an uneven shape on the surface of the pressure-sensitive adhesive sheet. In order to satisfy the storage modulus E 'at 100 ℃ in the above range, the storage modulus E' can be satisfied by adjusting the kind and content of the copolymerization component contained in the copolyester film.

On the other hand, the lower limit is not particularly limited, but is preferably 1.0X 10⁷Pa or more, more preferably 1.0X 10⁸Pa or above.

The shrinkage of the coated film after heating at 120 ℃ for 5 minutes is 3.0% or less, preferably 2.5% or less. Since the shrinkage ratio is 3.0% or less, sufficient dimensional stability is obtained, and therefore, when the pressure-sensitive adhesive sheet is laminated, a concave shape, a convex shape, or an uneven shape can be formed on the surface of the pressure-sensitive adhesive sheet. Further, since the occurrence of wrinkles can be suppressed during processing, wrinkles are not transferred to the pressure-sensitive adhesive sheet, and a pressure-sensitive adhesive sheet having a sufficient appearance can be produced.

Among them, the shrinkage in the Machine Direction (MD) after heating at 120 ℃ for 5 minutes is preferably 3.0% or less, and preferably 2.5% or less. On the other hand, the lower limit is not particularly limited, but is preferably 0.1% or more, more preferably 0.5% or more.

The shrinkage in The Direction (TD) perpendicular to the machine direction after heating at 120 ℃ for 5 minutes is preferably 1.0% or less, and preferably 0.8% or less. On the other hand, the lower limit is preferably-1.0% or more, more preferably-0.5% or more.

The present coating film can be prevented from suffering from the formation of oligomers (cyclic trimer) during the forming processFrom the viewpoint of contamination due to adhesion of a mold, the amount of oligomer extracted from the surface of the coating layer after heat treatment (180 ℃ C., 10 minutes) is preferably 1.0X 10^-3mg/cm²The following, more preferably 5.0X 10^-4mg/cm²The following.

When the oligomer extraction amount exceeds this range, the contamination by the adhesion of the oligomer to the mold may be serious during the molding process. For example, in a process in which thermoforming is continuously performed a plurality of times, deposition of precipitated oligomers promotes mold fouling, and therefore, control of the amount of oligomer precipitated during heating is important. For the above reasons, the smaller the oligomer extraction amount is, the more preferable.

[ method for producing adhesive sheet laminate ]

An example of a method for producing the adhesive sheet laminate of the present invention is a method in which an adhesive composition is sandwiched between 2 sheets of the cover I or II, and an adhesive material layer is formed using a laminator. In addition, another method is a method of forming an adhesive material layer by applying an adhesive composition to the cover I or II. However, the method is not limited to these production methods.

Examples of the method of applying the adhesive composition include conventionally known application methods such as reverse roll coating, gravure coating, bar coating, and blade coating.

[ shaped adhesive sheet laminate ]

Using the present adhesive sheet laminate, a shaped adhesive sheet laminate 1 having a concavo-convex shape formed on the surface of an adhesive material layer (referred to as "the present shaped adhesive sheet laminate 1") can be produced as follows.

As shown in FIG. 3, the shaped adhesive sheet laminate 1 comprises an adhesive material layer 2, a covering section I formed by laminating the adhesive material layer 2 so as to be peelable on one of the front and back sides thereof, and a covering section II formed by laminating the adhesive material layer 2 so as to be peelable on the other of the front and back sides thereof,

the adhesive material layer 2 has concave or convex or concave-convex portions (referred to as "adhesive sheet surface concave-convex portions 2B") on the front and back surface side surfaces 2A, and the front and back surface side surfaces 2C are flat surfaces,

the cover (I) is in close contact with the front and back surfaces (2A) of the adhesive material layer (2), and has concave or convex or concave-convex portions (referred to as "cover surface concave-convex portions (3B)") on the front and back surfaces (3A), and convex or concave or convex-concave portions (referred to as "protective sheet back surface concave-convex portions (3D)") corresponding to the adhesive sheet surface concave-convex portions (2B), in other words, forming concave-convex portions to be fitted to each other, on the sheet back surface (3C),

the covering portion II may have a flat surface along the front and back surfaces 2C of the adhesive material layer 2.

The front-surface and back-surface other side surfaces 2C may be flat surfaces as shown in fig. 3, or may be formed to have concave portions, convex portions, or concave-convex portions on the front-surface and back-surface other side surfaces 2C.

As shown in fig. 2, the present shaped adhesive sheet laminate 1 having such a configuration can be produced by: the adhesive sheet laminate is produced by subjecting the adhesive sheet laminate to press molding, vacuum molding, pressure-air molding or roll molding to integrally form the uneven shape.

By producing in this manner, the adhesive sheet surface irregularities 2B of the adhesive material layer 2, the covering part surface irregularities 3B of the covering part I, and the protective sheet back surface irregularities 3D can be formed at the same positions and in a corresponding manner.

The pressure-sensitive adhesive layer 2 can be used, for example, as a double-sided pressure-sensitive adhesive sheet for bonding 2 image display device constituting members (each of which may be referred to as an "adherend") constituting an image display device.

That is, the psa sheet surface irregularities 2B in the psa material layer 2 may preferably be formed in the same contour shape so as to correspond to the recesses or projections or irregularities (referred to as "adherend surface irregularities") in the attaching surface (also referred to as "attaching surface") of the adherend. Therefore, the adhesive sheet surface uneven portion 2B in the present shaped adhesive sheet laminate 1 can be fitted to the adherend surface uneven portion in the image display device constituting member as the adherend.

Examples of the image display device include a smart phone, a tablet terminal, a mobile phone, a television, a game machine, a personal computer, a car navigation system, an ATM, a fish detector, and the like, which are provided with 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. However, the present invention is not limited to these examples.

The member constituting the image display device as the adherend means a member constituting the image display device, and examples thereof include a surface protective panel, a touch panel, an image display panel, and the like, and the shaped adhesive sheet laminate 1 can be used for bonding any two adherends selected from the surface protective panel, the touch panel, and the image display panel, for example. For example, it can be used to attach a surface protective panel to a touch panel or a touch panel to an image display panel. However, the adherend is not limited to these.

< production method >

Here, the method for producing the shaped adhesive sheet laminate 1 of the present invention will be described in detail.

As described above, the adhesive sheet laminate 1 can be manufactured by integrally forming the uneven shape by heating and molding the adhesive sheet laminate as shown in fig. 2.

In this case, examples of the forming method include press forming, vacuum forming, pressure-air forming, shaping by a roll, shaping by lamination, and the like. Among them, press forming is particularly preferable from the viewpoint of formability and workability.

A more detailed specific example will be described.

The present adhesive sheet laminate is preheated by a heater, and at the stage of heating to a predetermined temperature, the present adhesive sheet laminate is conveyed to a press molding machine, and the shape of the mold is transferred to one surface of the present adhesive sheet laminate by press-working in advance with a mold that follows the uneven shape of the portion corresponding to the print level difference shape of the adherend, and cooling, whereby the present shaped adhesive sheet laminate 1 having the uneven shaped shape formed on one surface can be produced.

In this case, the preheating of the adhesive sheet laminate is preferably carried out at a temperature at which the adhesive material layer softens, specifically, 70 to 120 ℃.

The material of the mold used for the uneven shaping is not particularly limited. Examples thereof include resin materials such as silicone resins and fluororesins, and metal materials such as stainless steel and aluminum. Among them, a metal mold capable of controlling the temperature at the time of molding is particularly preferable in terms of the requirement for high-precision moldability for the concave-convex shape-forming of the adherend.

The cooling after the press working may be performed after the mold opening, or the mold may be cooled in advance and cooled simultaneously with the pressing.

In the present invention, conditions to be applied in forming such as pressing pressure and pressing time are not particularly specified, and may be appropriately adjusted depending on the size, shape, material to be used, and the like of the forming.

Further, the cutting may be performed by using a thomson blade, a rotary blade, or the like after the molding.

[ method for producing shaped adhesive sheet laminate ]

Next, a particularly preferred embodiment of a method for producing a shaped adhesive sheet laminate having a configuration in which a coating section I formed by laminating an adhesive material layer and a peelable layer on one surface of the adhesive material layer is formed and a concave or convex section or a concave-convex section (referred to as "adhesive material layer surface concave-convex section") is formed on one surface of the adhesive material will be described.

The present invention relates to the present production method 1 and the present production method 2 described below, and proposes a novel method for producing a shaped adhesive sheet laminate which can form, with high accuracy, uneven portions on the surface of an adhesive material layer corresponding to the uneven portions on the surface of an adherend, and which can preferably be produced continuously.

As an example of the embodiment of the present invention, a novel method for producing an adhesive sheet shaped laminate (referred to as "the present production method 1") comprising an adhesive material layer and a cover section I formed by laminating the adhesive material layer on one surface thereof in a peelable manner, and having a pressure sensitive adhesive layer is proposedThe method for producing a shaped adhesive sheet laminate comprises heating an adhesive sheet laminate comprising an adhesive material layer and a cover section I formed by laminating the adhesive material layer on one surface in a peelable manner, molding the heated adhesive sheet laminate and cooling the molded adhesive sheet laminate, and heating the adhesive sheet laminate so that the storage modulus E' (MS) of the cover section I is 1.0 x 10⁶～2.0×10⁹The molding was started in a state of Pa, and the storage modulus E' (MF) of the covering section I was 5.0X 10⁷～1.0×10¹⁰The molding is finished in a state of Pa.

In the present production method 1, it is also proposed that, in the above-described novel shaped adhesive sheet laminate production method, when the heated adhesive sheet laminate is molded, molding is performed using a cooled mold.

According to the production method 1, for example, after the adhesive sheet laminate is heated, the molding is started in a state where the covering section I is predetermined, and the molding is completed in a state where the covering section I is predetermined, whereby the uneven shape corresponding to the uneven portion on the surface of the adherend can be formed on the surface of the adhesive material layer with high accuracy.

Further, when the heated adhesive sheet laminate is molded, the molding can be completed simultaneously with the cooling by using a cooled mold, and therefore the above-described manufacturing method can be continuously performed.

< method 1> of production

In the present production method 1, the method for producing a shaped adhesive sheet laminate (referred to as "the present production method") according to the present embodiment includes the steps of: heating an adhesive sheet laminate (described later) (heating step); and a step of molding and cooling the heated adhesive sheet laminate (molding/cooling step).

The present manufacturing method 1 may include other steps as long as it includes the heating step and the forming/cooling step. For example, a heat treatment step, a conveying step, a slitting step, a cutting step, and the like may be provided as necessary. However, the method is not limited to these steps.

(adhesive sheet laminate)

The psa sheet laminate as the starting member in the present manufacturing method 1 may include an adhesive material layer and a cover section I laminated on one surface of the adhesive material layer so as to be peelable, and may include other members. For example, as shown in fig. 1, there can be exemplified a pressure-sensitive adhesive sheet laminate comprising a pressure-sensitive adhesive layer, a cover section I laminated so as to be peelable on one of the front and back surfaces of the pressure-sensitive adhesive layer, and a cover section II laminated so as to be peelable on the other of the front and back surfaces of the pressure-sensitive adhesive layer. However, whether or not the covering section II is provided is arbitrary, and a structure in which the covering section II is not laminated may be employed.

The details of the psa sheet laminate are as described above.

(heating step)

In the present production method 1, the pressure-sensitive adhesive sheet laminate is preferably heated so that the storage modulus E' (M) of the cover section I is 1.0 × 10⁶～2.0×10⁹State of Pa.

When the storage modulus E' (M) of the covering portion I is in the above range, the covering portion I can be deformed to an extent suitable for molding, and a desired uneven shape can be accurately formed on the surface of the adhesive material layer.

From the above viewpoint, it is preferable that the adhesive sheet laminate is heated so that the storage modulus E' (M) of the cover section I is 1.0 × 10⁶～2.0×10⁹Pa, among them, it is more preferably 5.0X 10⁶Pa or more or 1.0X 10⁹Pa or less, especially 1.0X 10⁷Pa or more or 5.0X 10⁸Pa or less.

From the above, it is more preferable that the storage modulus E' (M) of the cover section I is 1.0 × 10 by heating the adhesive sheet laminate⁶～1.0×10⁹Pa or 1.0X 10⁶～5.0×10⁸Among them, it is more preferable to set the state of (1) to 5.0X 10⁶～2.0×10⁹Pa or 5.0X 10⁶～1.0×10⁹The state of Pa is a state of,most preferably 1.0X 10⁷～1.0×10⁹Pa or 1.0X 10⁷～～5.0×10⁸The state of (1).

Here, in order to adjust the storage modulus E' (M) of the coated section I to be within the above range by heating the adhesive sheet laminate, the heating temperature may be adjusted according to the components of the composition constituting the coated section I, the gel fraction, the weight average molecular weight, and the like. However, the method is not limited to these methods.

Further, it is more preferable to provide: the adhesive sheet laminate was heated to set the storage modulus E' (M) of the cover section I to 1.0X 10⁶～2.0×10⁹Pa, and the storage modulus G' (S) of the adhesive material layer is less than 1.0X 10⁴State of Pa.

When the storage modulus E '(M) of the covering section I is adjusted to the above range, the above-described effects can be obtained, and when the storage modulus G' (S) of the adhesive material layer is less than 1.0 × 10⁴Pa, sufficient formability can be imparted to the adhesive material layer.

From the above viewpoint, it is preferable that the adhesive sheet laminate is heated so that the storage modulus E '(M) of the cover section I is in the above range and the storage modulus G' (S) of the adhesive material layer is less than 1.0 × 10⁴State of Pa, particularly 5.0X 10¹Pa or more or 5.0X 10³State of Pa or less, particularly 1.0X 10²Pa or more or 1.0X 10³Pa or less.

From the above, it is more preferable that the adhesive sheet laminate is heated so that the storage modulus E '(M) of the cover section I is in the above range and the storage modulus G' (S) of the adhesive material layer is 5.0 × 10¹Pa is not less than 1.0X 10⁴Pa, or 5.0X 10¹Pa or more and 5.0X 10³Pa or less, among them, 1.0X 10 is more preferable²Pa is not less than 1.0X 10⁴Pa, or 1.0X 10²Pa or more and 5.0X 10³The most preferable range is 1.0X 10 Pa or less²Pa or more and 1.0X 10³Pa or less.

Here, the storage modulus G' (S) of the adhesive material layer can be adjusted by adjusting the heating temperature according to the components of the composition constituting the adhesive material layer, the gel fraction, the weight average molecular weight, and the like. However, the method is not limited to the above method.

Further, it is particularly preferable that the loss tangent tan δ of the adhesive material layer is 1.0 or more by heating the adhesive sheet laminate. The loss tangent tan δ will be described later.

When the value of the loss tangent tan δ of the adhesive material layer is 1.0 or more, flexibility is imparted to the adhesive material layer to such an extent that the adhesive material layer can be molded.

From the above-described viewpoint, it is particularly preferable that the loss tangent tan δ of the adhesive material layer is 1.0 or more, more preferably 1.5 or more or 20 or less, and particularly preferably 3.0 or more or 10 or less, by heating the adhesive sheet laminate. However, the upper limit is not limited thereto.

In the production method 1, the adhesive sheet laminate is preferably heated so that the surface temperature of the cover section I is 70 to 180 ℃.

When the surface temperature of the covering section I is 70 ℃ or more, the adhesive material layer can be sufficiently softened and the covering section I can be sufficiently deformed, and when the surface temperature is 180 ℃ or less, adverse effects such as generation of wrinkles due to thermal shrinkage and decomposition of the adhesive material layer due to heat can be suppressed, and therefore, it is preferable.

From the above viewpoint, the adhesive sheet laminate is preferably heated so that the surface temperature of the cover section I is 70 to 180 ℃, more preferably 75 ℃ or more or 150 ℃ or less, particularly 80 ℃ or more or 120 ℃ or less.

Examples of heating methods for the adhesive sheet laminate include a method in which the adhesive sheet laminate is heated from the top and bottom by interposing the adhesive sheet laminate between top and bottom heating plates having a heating body such as an electrothermal heater therein; a method of direct clamping with a heating plate; a method using a heating roller; a method of immersing in hot water, and the like. However, the method is not limited to these methods.

(shaping/Cooling Process)

In this step, the adhesive sheet laminate heated as described above is molded, and the adhesive sheet laminate is molded and cooled. That is, the adhesive sheet laminate in which the adhesive material layer and the cover section I are laminated and integrated is directly molded. In this way, the cover I is molded by the mold, and the adhesive material layer is also molded simultaneously with the cover I.

In this step, the heated adhesive sheet laminate may be cooled after molding, or may be cooled simultaneously with molding. For example, pressing with a cooled die, whereby the forming and cooling can be performed simultaneously and finished simultaneously. This enables the present production method 1 to be continuously carried out as described later.

The molding method is not particularly limited as long as the uneven shape can be integrally formed in the adhesive sheet laminate. Examples thereof include press forming, vacuum forming, pressure-air forming, shaping by a roller, compression forming, shaping by lamination, and the like. Among them, press forming is particularly preferable from the viewpoint of formability and workability.

The material of the mold is not particularly limited. Examples thereof include resin materials such as silicone resin and fluororesin, and metal materials such as stainless steel and aluminum. Among them, a metal mold capable of controlling the temperature during molding is particularly preferable in terms of the requirement for high-precision moldability for the concave-convex shape-forming of an adherend.

The cooling means for the mold may be any conventionally used cooling means. Examples thereof include water cooling and cooling by compressed air.

As shown in fig. 2, for example, the uneven shape corresponding to a predetermined uneven shape, for example, a concave or convex or uneven shape in a bonding surface (also referred to as a "bonding surface") of an adherend to which an adhesive material layer is to be bonded is provided in advance on an inner wall surface of at least one of a pair of opened and closed molds, and the adhesive sheet laminate is subjected to press molding, vacuum molding, pressure-vacuum molding, or roll molding using the mold, whereby the uneven shape can be transferred to the adhesive sheet laminate to be shaped.

In this step, as described above, the storage modulus E' (MS) of the cover I in the psa sheet laminate is preferably 1.0 a10⁶～2.0×10⁹Forming is started in a state of Pa.

Here, "start of molding" means that, for example, in the case of molding using a mold, the mold is closed, that is, the pressure of the adhesive sheet laminate is started using the mold.

The storage modulus E' (MS) of the cover I is 1.0X 10⁶～2.0×10⁹In the range of Pa, the covering portion I can be deformed to an extent suitable for molding, and a desired uneven shape can be accurately formed on the surface of the adhesive material layer.

From the above viewpoint, the storage modulus E' (MS) of the covering section I is preferably 1.0 × 10⁶～2.0×10⁹The pressure-sensitive adhesive sheet laminate is preferably molded at 5.0X 10 Pa⁶Pa or more or 1.0X 10⁹State of Pa or less, particularly 1.0X 10⁷Pa or more or 5.0X 10⁸Forming is started in a state of Pa or less.

From the above, the storage modulus E' (MS) of the covering section I is more preferably 1.0 × 10⁶～1.0×10⁹Pa or 1.0X 10⁶～5.0×10⁸The molding of the adhesive sheet laminate is started in a state of Pa, and more preferably 5.0X 10⁶～1.0×10⁹Pa or 5.0X 10⁶～5.0×10⁸The molding is started in the state of Pa, and most preferably 1.0X 10⁷～1.0×10⁹Pa or 1.0X 10⁷～5.0×10⁸Forming is started in a state of Pa.

Further, the storage modulus E' (MS) of the covering section I is preferably 1.0X 10⁶～2.0×10⁹Pa, and the storage modulus G' (SS) of the adhesive material layer is less than 1.0X 10⁴The molding of the adhesive sheet laminate was started in a Pa state.

When the forming is started in a state where the storage modulus E '(MS) of the covering section I is in the aforementioned range, the effects as described above can be obtained, and further, the storage modulus G' (SS) of the adhesive material layer is less than 1.0 × 10⁴When the molding is started in the state of Pa, the adhesive material layer can be molded in a state having more sufficient moldability.

From the above viewpoint, the following is further madeThe storage modulus E '(MS) of the covering section I is in the above-mentioned range, and the storage modulus G' (SS) of the adhesive material layer is preferably less than 1.0X 10⁴Pa, in particular, G' (SS) of 5.0X 10¹Pa or more or 5.0X 10³Pa or less, and more preferably 1.0X 10²Pa or more or 1.0X 10³Forming is started in a state of Pa or less.

From the above, it is more preferable that the storage modulus E '(MS) of the covering section I is in the above range, and the storage modulus G' (SS) of the adhesive material layer is 5.0 × 10¹Pa is not less than 1.0X 10⁴Pa, or 5.0X 10¹Pa or more and 5.0X 10³The molding is started in a state of Pa or less, and among them, 1.0X 10 is more preferable²Pa is not less than 1.0X 10⁴Pa, or 1.0X 10²Pa or more and 5.0X 10³The molding is started under Pa or less, and most preferably 1.0X 10²Pa or more and 1.0X 10³Forming is started in a state of Pa or less.

Preferably, the molding is started in a state where the surface temperature of the covering section I is 70 to 180 ℃.

When the surface temperature of the covering section I is 70 ℃ or more, the adhesive material layer can be sufficiently softened and the covering section I can be sufficiently deformed, and when the surface temperature is 180 ℃ or less, defects such as generation of wrinkles due to thermal shrinkage and decomposition of the adhesive material layer due to heat can be suppressed, and therefore, this is preferable.

Therefore, the molding is preferably started in a state where the surface temperature of the covering section I is 70 to 180 ℃, and more preferably 75 ℃ or more or 150 ℃ or less, particularly 80 ℃ or more or 120 ℃ or less.

On the other hand, in this step, the storage modulus E' (MF) of the covering section I is preferably 5.0 × 10⁷～1.0×10¹⁰The molding is finished in a state of Pa.

Here, "finishing molding" means finishing applying the molding pressure to the adhesive sheet laminate, and if molding is performed, it means opening the mold.

The storage modulus E' (MF) of the covering section I is 5.0X 10⁷Pa or more and 1.0X 10¹⁰Range of Pa or lessIn the case of the resin composition, the shape stability after molding is excellent, and therefore, the resin composition is preferable.

From the above viewpoint, the storage modulus E' (MF) of the covering section I is preferably 5.0 × 10⁷～1.0×10¹⁰The molding is terminated in the state of Pa, and more preferably 1.0X 10⁸Pa or more or 8.0X 10⁹State of Pa or less, particularly 1.0X 10⁹Pa or more or 5.0X 10⁹The molding is finished in a state of Pa or less.

From the above, in this step, the storage modulus E' (MF) of the covering portion I is more preferably 5.0 × 10⁷～8.0×10⁹Pa, or 5.0X 10⁷～5.0×10⁹The molding is terminated in a state of Pa, and among them, it is preferably 1.0X 10⁸～8.0×10⁹Pa or 1.0X 10⁸～5.0×10⁹The molding is finished in the state of Pa, and the most preferable range is 1.0X 10⁹～8.0×10⁹Pa or 1.0X 10⁹～5.0×10⁹The molding is finished in a state of Pa.

Further, it is more preferable that the storage modulus E '(MF) of the covering section I is in the above range, and the storage modulus G' (SF) of the adhesive material layer is 1.0 × 10⁴And finishing the forming under the state of Pa or above.

When the molding is completed in a state where the storage modulus E '(MF) of the covering portion I is in the above-mentioned range, the above-mentioned effects can be obtained, and further, when the storage modulus G' (SS) of the adhesive material layer is 1.0 × 10⁴When the molding is finished in a state of Pa or more, the molded adhesive material layer can maintain the shape.

From the above viewpoint, it is preferable that the storage modulus E '(MF) of the covering section I is in the above range, and the storage modulus G' (SF) of the adhesive material layer is 1.0 × 10⁴The molding is terminated in a state of Pa or more, and it is more preferable that the storage modulus G' (SF) of the adhesive material layer is 5.0X 10⁴Pa or more or 5.0X 10⁷State of Pa or less, particularly 1.0X 10⁴Pa or more or 1.0X 10⁷The molding is finished in a state of Pa or less.

Preferably, the molding is finished in a state where the surface temperature of the covering section I is less than 50 ℃. For example, in the case of press forming, it is preferable to open the mold in a state where the surface temperature is lower than 50 ℃.

When the surface temperature of the covering part I is lower than 50 ℃, the storage modulus E' (MS) of the covering part I is 5.0X 10⁷～1.0×10¹⁰The range of Pa can suppress deformation when the molded body is taken out after the molding is completed, and warpage due to thermal shrinkage of the covering section I.

From the above-mentioned viewpoint, it is preferable to finish the molding in a state where the surface temperature of the covering section I is lower than 50 ℃, in particular, in a state where the surface temperature is 0 ℃ or higher or 45 ℃ or lower, particularly, 10 ℃ or higher or 40 ℃ or lower.

Further, it is preferable that the storage modulus E '(MS) of the covering section I at the start of molding and the storage modulus E' (MF) of the covering section I at the end of molding satisfy the following relational expression (1).

(1)··E’(MF)/E’(MS)≥1.3

Here, it is preferable that the storage modulus E '(MS) of the covering portion I and the storage modulus E' (MF) of the covering portion I at the end of molding satisfy the relational expression (1) because the covering portion is softened to such an extent that molding can be performed at the start of molding and has hardness to such an extent that the molded shape can be maintained after the end of molding.

From the above-mentioned viewpoint, E '(MF)/E' (MS) ≥ 1.3 is preferable, and among them, 100 ≥ E '(MF)/E' (MS) or E '(MF)/E' (MS) ≥ 3.0 is more preferable, and 50 ≥ E '(MF)/E' (MS) or E '(MF)/E' (MS) ≥ 5.0 is particularly preferable. However, the upper limit of E '(MF)/E' (MS) is not limited to these.

Preferably, the storage modulus E '(MF) of the covering section I at the end of molding and the storage modulus G' (SF) of the pressure-sensitive adhesive material layer at the end of molding satisfy the following relational expression (2).

(2)··E’(MF)/G’(SF)≤1.0×10⁷

Here, if the storage modulus E '(MF) of the covering section I at the end of the molding and the storage modulus G' (SF) of the adhesive material layer at the end of the molding satisfy the relational expression (2), the molded adhesive material layer can maintain the shape.

From the above viewpoint, E '(MF)/G' (SF) ≦ 1.0X 10 is preferable⁷Wherein 1.0. ltoreq. E '(MF)/G' (SF) or E '(MF)/G' (SF) is more preferably 1.0. ltoreq. 5.0X 10⁶In particular 1.0X 10¹E '(MF)/G' (SF) or E '(MF)/G' (SF) is not more than 1.0X 10⁶。

In the present manufacturing method 1, the press molding may be performed with a mold and the mold may be opened and then cooled, or the mold may be cooled in advance and cooled simultaneously with the press molding. When the mold is cooled in advance and the cooling is performed simultaneously with the press molding in this manner, the cooling can be finished simultaneously with the molding. Therefore, the shaped adhesive sheet laminate can be transported to the next step immediately after the completion of the molding and cooling, and thus the shaped adhesive sheet laminate can be continuously produced.

When the mold is cooled while being molded, the surface temperature of the mold is preferably 0 to 50 ℃.

When the surface temperature of the mold is 50 ℃ or lower, the shape of the adhesive sheet laminate can be fixed in a short time, and the molded article obtained is preferable in terms of good precision and suppression of warpage due to thermal shrinkage during cooling after molding.

Therefore, the surface temperature of the mold is preferably 0 to 50 ℃, more preferably 10 ℃ or more or 40 ℃ or less, particularly 15 ℃ or more or 30 ℃ or less.

The conditions to be applied in the press forming such as the pressing pressure and the pressing time are not particularly limited, and may be appropriately adjusted depending on the size, shape, material to be formed, and the like.

(others)

The shaped adhesive sheet laminate obtained in the molding/cooling step may be wound as it is, may be subjected to a heat treatment, or may be cut into a predetermined size and shape.

In the case of cutting, for example, a method of cutting with a thomson blade, a rotary blade, or the like is used.

In the present production method 1, the shaped adhesive sheet laminate is preferably produced continuously.

For example, the adhesive sheet laminate is conveyed to a heating unit such as a heater, and after the heating unit stops conveying and heats for a predetermined time or heats while conveying, the heated adhesive sheet laminate is conveyed to a molding unit such as a molding die, and the molding unit is pressed with a cooled die and cooled while molding, for example, and further conveyed to the next unit as needed, whereby a shaped adhesive sheet laminate can be continuously produced.

< method 2> of production

As an example of the embodiment of the present invention, there is proposed a method for producing a shaped adhesive sheet laminate (referred to as "present production method 2") comprising a pressure-sensitive adhesive layer and a covering section I formed by laminating the pressure-sensitive adhesive layer so as to be peelable on one surface thereof, and having a configuration in which a concave portion, a convex portion, or a concave-convex portion (referred to as "pressure-sensitive adhesive layer surface concave-convex portion") is formed on one surface of the pressure-sensitive adhesive layer, wherein the shaped adhesive sheet laminate is produced by heating a pressure-sensitive adhesive sheet laminate comprising a pressure-sensitive adhesive layer and a covering section I laminated so as to be peelable on one surface of the pressure-sensitive adhesive layer, molding the heated pressure-sensitive adhesive sheet laminate with a mold, and molding is started in a state in which the pressure-sensitive adhesive sheet laminate is heated and the surface temperature of the covering section I is 70 to 180 ℃, the shaped adhesive sheet laminate was taken out from the mold after the surface temperature of the cover part I was less than 60 ℃.

According to the production method 2, the adhesive sheet laminate is heated to start the molding with the surface temperature of the cover section I being 70 to 180 ℃, and the shaped adhesive sheet laminate is taken out from the mold after the surface temperature of the cover section I is less than 60 ℃, whereby the surface of the adhesive material layer can be accurately formed with, for example, irregularities corresponding to irregularities on the surface of the adherend.

The present manufacturing method 2 is a manufacturing method including the steps of: heating the adhesive sheet laminate (heating step) described later; and a step of molding and cooling the heated adhesive sheet laminate (molding/cooling step).

The present production method 2 may include other steps as long as it includes the heating step and the forming/cooling step. For example, a heat treatment step, a conveying step, a slitting step, a cutting step, and the like may be provided as necessary. However, the method is not limited to these steps.

(adhesive sheet laminate)

The psa sheet laminate as the starting member in the present manufacturing method 2 may be provided with other members as long as it includes a psa layer and a cover section I formed by laminating the psa layer on one surface thereof in a peelable manner. For example, as shown in fig. 1, there can be exemplified a pressure-sensitive adhesive sheet laminate comprising a pressure-sensitive adhesive layer, a cover section I laminated so as to be peelable on one of the front and back surfaces of the pressure-sensitive adhesive layer, and a cover section II laminated so as to be peelable on the other of the front and back surfaces of the pressure-sensitive adhesive layer. However, whether or not the covering section II is provided is arbitrary, and a structure in which the covering section II is not laminated may be employed.

The details of the psa sheet laminate are as described above.

(heating step)

In this step, the adhesive sheet laminate is preferably heated so that the surface temperature of the cover section I is 70 to 180 ℃.

When the surface temperature of the covering section I is 70 ℃ or more, the adhesive material layer can be sufficiently softened and the covering section I can be sufficiently deformed, and when the surface temperature is 180 ℃ or less, defects such as generation of wrinkles due to thermal shrinkage and decomposition of the adhesive material layer due to heat can be suppressed, and therefore, it is preferable.

From the above viewpoint, the surface temperature of the cover section I is preferably 70 to 180 ℃, more preferably 75 ℃ or more or 150 ℃ or less, particularly 80 ℃ or more or 120 ℃ or less, by heating the adhesive sheet laminate.

From the above, it is more preferable that the adhesive sheet laminate is heated so that the surface temperature of the cover section I becomes 70 to 150 ℃ or 70 to 120 ℃, further preferably 75 to 150 ℃ or 75 to 120 ℃, and most preferably 80 to 150 ℃ or 80 to 120 ℃.

Examples of the method for heating the adhesive sheet laminate include: a method of heating from the top and bottom by interposing an adhesive sheet laminate between upper and lower heating plates having a heating body such as an electrothermal heater therein; a method of direct clamping with a heating plate; a method using a heating roller; a method of immersing in hot water, and the like. However, the method is not limited to these methods.

(shaping/Cooling Process)

In this step, it is preferable that the molding of the adhesive sheet laminate is started in a state where the surface temperature of the cover section I is heated to 70 to 180 ℃. That is, it is preferable to directly mold the adhesive sheet laminate in which the adhesive material layer and the cover section I are laminated and integrated. In this case, the adhesive material layer can be molded by the cover I at the same time as the cover I is molded.

In this step, the heated adhesive sheet laminate may be cooled after molding, or may be cooled simultaneously with molding. For example, pressing with a cooled die, whereby the forming and cooling can be performed simultaneously and finished simultaneously. This enables continuous implementation of the present production method 2, as will be described later.

The molding method is not particularly limited as long as the uneven shape can be integrally formed in the adhesive sheet laminate. Examples thereof include press forming, vacuum forming, pressure-air forming, roll forming, compression forming, and forming by lamination. Among them, press forming is particularly preferable from the viewpoint of formability and workability.

When the molding is performed using a mold, the material of the mold is not particularly limited. Examples thereof include resin materials such as silicone resins and fluororesins, and metal materials such as stainless steel and aluminum. Among them, a metal-based mold capable of controlling the temperature during molding is particularly preferable in terms of the requirement for high-precision moldability for the concave-convex shape-forming of an adherend.

The cooling means for the mold may be any conventionally used cooling means. Examples thereof include water cooling and cooling by compressed air.

As shown in fig. 2, for example, the uneven shape corresponding to a predetermined uneven shape, for example, a concave or convex or uneven shape in a bonding surface (also referred to as a "bonding surface") of an adherend to which an adhesive material layer is to be bonded is provided in advance on an inner wall surface of at least one of a pair of opened and closed molds, and the adhesive sheet laminate is subjected to press molding, vacuum molding, pressure-vacuum molding, or roll molding using the mold, whereby the uneven shape can be transferred to the adhesive sheet laminate to be shaped.

As described above, it is preferable that the molding is started in a state where the surface temperature of the covering section I is 70 to 180 ℃. When the surface temperature of the covering section I is 70 ℃ or more, the adhesive material layer is sufficiently softened and the covering section I can be sufficiently deformed, and when the surface temperature is 180 ℃ or less, defects such as generation of wrinkles due to thermal shrinkage and decomposition of the adhesive material layer due to heat can be suppressed, and therefore, this is preferable.

Therefore, the molding is preferably started in a state where the surface temperature of the covering section I is 70 to 180 ℃, and more preferably 75 ℃ or more or 150 ℃ or less, particularly 80 ℃ or more or 120 ℃ or less.

On the other hand, in this step, the molding is preferably completed in a state where the surface temperature of the covering section I is lower than 60 ℃. For example, in the case of press forming, it is preferable to open the mold in a state where the surface temperature is lower than 60 ℃.

Here, "finishing molding" means finishing applying the molding pressure to the adhesive sheet laminate, and if molding is performed, it means opening the mold.

When the surface temperature of the covering section I is lower than 60 ℃, deformation at the time of taking out the molded body after completion of molding or warpage due to thermal shrinkage of the covering section I can be suppressed, and therefore, it is preferable.

From the above-mentioned viewpoint, it is preferable to finish the molding in a state where the surface temperature of the covering section I is lower than 60 ℃, in particular, in a state where the surface temperature is 0 ℃ or higher or 50 ℃ or lower, particularly, 10 ℃ or higher or 40 ℃ or lower.

In the present manufacturing method 2, the press molding may be performed with a mold and the mold may be opened and then cooled, or the mold may be cooled in advance and the press molding may be performed simultaneously with cooling. When the mold is cooled in advance and the cooling is performed simultaneously with the press molding in this manner, the cooling can be finished simultaneously with the molding. Therefore, the shaped adhesive sheet laminate can be transported to the next step immediately after the completion of the molding and cooling, and the shaped adhesive sheet laminate can be continuously produced.

In the case where cooling is performed while the mold is being formed, the surface temperature of the mold is preferably lower than 60 ℃.

When the surface temperature of the mold is less than 60 ℃, the shape of the adhesive sheet laminate can be fixed in a short time, and the molded article obtained is preferable in that the precision is good and warpage due to thermal shrinkage during cooling after molding can be suppressed.

Therefore, the surface temperature of the mold is preferably lower than 60 ℃, and more preferably 0 ℃ or higher or 50 ℃ or lower, particularly 10 ℃ or higher or 40 ℃ or lower.

The difference between the surface temperature of the covering section I at the start of molding and the surface temperature of the covering section I at the end of molding is preferably 10 to 100 ℃, and more preferably 20 ℃ or higher or 90 ℃ or lower. When the difference in surface temperature of the cover section I is 10 to 100 ℃, for example, when the uneven shape is transferred to the adhesive sheet laminate and shaped, the shaped adhesive sheet laminate can be immediately conveyed to the next step after completion of the shaping and cooling, and therefore the shaped adhesive sheet laminate can be continuously produced.

The conditions to be applied in the press forming such as the pressing pressure and the pressing time are not particularly limited, and may be appropriately adjusted depending on the size, shape, material to be formed, and the like.

(others)

The shaped adhesive sheet laminate obtained in the molding/cooling step may be wound as it is, may be subjected to a heat treatment, or may be cut into a predetermined size and shape.

In the case of cutting, for example, a thomson blade, a rotary blade, or the like may be used.

In the present production method 2, the shaped adhesive sheet laminate is preferably produced continuously.

For example, the shaped adhesive sheet laminate can be continuously produced by conveying the adhesive sheet laminate to a heating unit such as a heater, stopping the conveyance for heating for a predetermined time or heating while conveying, then conveying the heated adhesive sheet laminate to a molding unit such as a molding die, pressing the adhesive sheet laminate with the molding unit using a cooled die, cooling the adhesive sheet laminate while molding, and further conveying the adhesive sheet laminate to the next unit as needed.

< use >

Here, an example of the use application of the present shaped adhesive sheet laminate 1 will be described.

In recent years, with the widespread use of mobile phones, smartphones, tablet terminals, and the like, there have been many cases where the image display portion is damaged by a user's mistake, such as dropping. In particular, when the image display device is of a touch panel type, it is difficult to see the display due to breakage, and the touch panel operation itself becomes impossible or causes a failure due to physical obstruction, water intrusion, or the like. Therefore, repair, which is maintenance of replacing only the image display portion, may be performed.

In the maintenance of the image display device, the adhesive sheet may be used when a new image display unit is loaded. Generally, the repair is performed manually by a repair operator in many cases, and the skill of the repair operator is necessary. That is, if the person is not skilled, when the image display portion is loaded with the adhesive sheet, air is mixed into the inside or the adhesive material overflows.

On the other hand, since the shaped adhesive sheet laminate 1 can be provided with a highly accurate step shape in advance, for example, by providing a step shape corresponding to the model of the image display device in advance to the adhesive material layer, the maintenance work can be greatly simplified and the shaped adhesive sheet laminate can be implemented without requiring the skill of the repair worker. In this manner, the adhesive sheet laminate of the present invention can be usefully used for maintenance of an image display device.

< description of sentence >

In the present specification, unless otherwise specified, the term "X to Y" (X, Y is an arbitrary number) includes the meaning of "X to Y" and includes the meaning of "preferably greater than X" or "preferably less than Y".

In addition, the meaning of "preferably larger than X" or "preferably smaller than Y" is also included in the case where "X is larger than X" (X is an arbitrary number) or "Y is smaller than Y" (Y is an arbitrary number).

In the present invention, the boundary between the sheet and the film is not clear, and in the present invention, it is not necessary to distinguish the two in terms of language, and therefore, in the present invention, the case of being referred to as "film" also includes "sheet", and the case of being referred to as "sheet" also includes "film".

Examples

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

[ example/comparative example set 1]

< cover 1-I >

The adhesive sheet laminates 1-I of examples 1-1 to 1-3 and comparative example 1-1 (hereinafter, collectively referred to as "example/comparative example set 1") were each provided with the following covers 1-A to 1-D. The values of the respective storage moduli are shown in table 1.

Cover 1-a: a film comprising a biaxially stretched isophthalic acid copolymerized PET film (thickness: 75 μm) and a release layer (thickness: 2 μm) comprising a silicone compound laminated on one surface thereof.

Cover 1-B: a release layer (thickness: 38 μm) comprising a modified polyolefin was laminated on one surface of a non-stretched polyolefin film (thickness: 50 μm) comprising 4-methyl-1-pentene.

Cover 1-C: a film formed of a polyolefin film (thickness: 70 μm) comprising unstretched polypropylene.

Cover 1-D: a film comprising a biaxially stretched homopolyPET film (thickness: 75 μm) and a release layer (thickness: 2 μm) comprising a silicone compound laminated on one surface thereof.

< examples 1 to 1>

(preparation of double-sided adhesive sheet)

1kg of an acrylic copolymer (1-a-1) (weight-average molecular weight: 23 ten thousand) as a (meth) acrylic copolymer (1-a), 90g of glycerol dimethacrylate (manufactured by Nichikura, product name: GMR) (1-b-1) as a crosslinking agent (1-b), and 15g of a mixture of 2,4, 6-trimethylbenzophenone and 4-methylbenzophenone (manufactured by Lanberti Co., product name: Esacure TZT) (1-c-1) as a photopolymerization initiator (1-c) were uniformly mixed, and the acrylic copolymer (1-a-1) was obtained by randomly copolymerizing 15 parts by mass (18 mol%) of a polymethyl methacrylate macromonomer (Tg: 105 ℃) having a number-average molecular weight of 2400, 81 parts by mass (75 mol%) of butyl acrylate (Tg: -55 ℃) and 4 parts by mass (7 mol%) of acrylic acid (Tg: 106 ℃) Thereby producing the resin composition 1-1 for an adhesive material layer. The glass transition temperature of the resulting resin composition was-5 ℃.

The obtained resin composition 1-1 was sandwiched between a release-treated PET film (product name: Diafil MRV-V06, manufactured by Mitsubishi resin corporation, thickness: 100 μm) and a cover 1-A, and the resin composition 1-1 was shaped into a sheet form so that the thickness of the resin composition 1-1 became 100 μm using a laminator to prepare an adhesive sheet laminate 1-1. The release layer side of the covering portion 1-a is disposed so as to be in contact with the resin composition 1-1.

The adhesive sheet laminate 1-1 thus obtained was thermoformed using a vacuum press molding machine (FKS-0632-20 type, manufactured by first Utility Co., Ltd.) by the following process to prepare a shaped adhesive sheet laminate 1-1.

Specifically, the surface of the adhesive sheet laminate 1-1 was heated to 100 ℃ by an IR heater preheated to 400 ℃, and then press-molded for 5 seconds under a mold clamping pressure of 8MPa using a molding mold cooled to 25 ℃ to produce an shaped adhesive sheet laminate 1-1 having a surface shaped into irregularities.

< examples 1 and 2>

An adhesive sheet laminate 1-2 and a shaped adhesive sheet laminate 1-2 were produced in the same manner as in example 1-1, except that the cover 1-B was used instead of the cover 1-a.

< examples 1 to 3>

Adhesive sheet laminates 1-3 and shaped adhesive sheet laminates 1-3 were produced in the same manner as in example 1-1, except that the coated portion 1-C was used instead of the coated portion 1-a.

< comparative example 1-1>

Adhesive sheet laminates 1 to 4 and shaped adhesive sheet laminates 1 to 4 were produced in the same manner as in example 1-1, except that the cover 1-D was used instead of the cover 1-a.

< measurement and evaluation methods >

The measurement method and evaluation method of various physical property values of the samples obtained in examples 1-1 to 1-3/comparative example 1-1 will be described.

(modulus of elasticity of covering part)

The covers 1-A to 1-D used in group 1 of examples and comparative examples were cut to have a length of 50mm and a width of 4mm, and measured by applying a strain of 1% at a chuck pitch of 25mm using a dynamic visco-elastic device (アイティー Kogyo DVA-200). The measurement is carried out under the conditions that the measurement temperature range is-50 ℃ to 150 ℃, the frequency is 1Hz, and the temperature rise speed is 3 ℃/min. The storage modulus at 100 ℃ of the obtained data was designated as E '(MA), and the storage modulus at 30 ℃ was designated as E' (MB).

(modulus of elasticity of adhesive material layer)

The adhesive material layers obtained in example/comparative example group 1 were stacked to a thickness of 1mm, and measured using a rheometer (MARSII, manufactured by Thermo Fisher Scientific Co.). The measurement is carried out under the conditions that the measurement temperature range is-50 ℃ to 150 ℃, the frequency is 1Hz, and the temperature rise speed is 3 ℃/min.

The values of storage modulus at 100 ℃ and loss modulus at 30 ℃ in the obtained data were G ' (SA), G ' (SB), and G "/G ' at each temperature were G ″, and the loss tangent tan δ (SA, SB) of each adhesive material layer.

(gel fraction)

The gel fraction of the adhesive material layer was determined as follows: the adhesive material layers obtained in group 1 of examples/comparative examples were each measured by collecting an amount of about 0.05g, wrapping the adhesive material layers in a bag shape with a SUS mesh (#200) whose mass (X) was measured in advance, folding the bag mouth to seal the bag mouth, measuring the mass (Y) of the wrapping, immersing the resultant product in 100ml of ethyl acetate, storing the resultant product in a dark place at 23 ℃ for 24 hours, taking out the wrapping, heating the resultant product at 70 ℃ for 4.5 hours to evaporate the adhering ethyl acetate, measuring the mass (Z) of the dried wrapping, and substituting the obtained mass into the following equation.

Gel fraction [% ] [ (Z-X)/(Y-X) ] × 100

(moldability)

In order to confirm moldability, a molding test of group 1 of examples/comparative examples was carried out using a mold described below. That is, as shown in FIG. 5, one of the upper and lower dies for molding is a male die having a length of 270mm, a width of 170mm and a thickness of 40mm, and the other of the upper and lower dies is a flat aluminum plate having a length of 270mm, a width of 170mm and a thickness of 40 mm.

As shown in FIG. 5, a convex portion having a vertical length of 187mm, a horizontal length of 125mm and a height of 1mm was provided at the center of the molding surface of the male mold, and further, 4 molding concave portions having a rectangular plan view (a length of 89mm and a width of 58mm) and having a depth of 25 μm, 50 μm, 75 μm and 100 μm were provided in the molding surface of the convex portion.

The covering portions 1-a to 1-D of the shaped uneven adhesive sheet laminate obtained by the method described in group 1 of examples/comparative examples were peeled off, and the heights of the concave portions corresponding to the print height difference and the convex portions corresponding to the display surface were measured in a non-contact manner using a scanning white interference microscope.

The height h of the convex portion (and the edge portion of the concave portion) of the molded article was measured at a depth of 100 μm with respect to the mold, and a case where the transfer ratio derived from the following calculation formula was 50% or more was evaluated as "o", and a case where the transfer ratio was less than 50% was evaluated as "x".

Transfer ratio (%) < h (height of molded article)/100 (depth of mold) × 100

(Peel force)

The adhesive sheet laminate produced in group 1 of examples/comparative examples was cut out to have a length of 150mm and a width of 50mm, and a 180 ° peel test was performed at a test speed of 300 mm/min on the interface between the cover parts 1-a to 1-D and the adhesive material layer.

The peel strength of the covering parts 1-A to 1-D was defined as F (C) for the peel strength in an environment of 30 ℃ and F (D) for the peel strength after heating at 100 ℃ for 5 minutes and then naturally cooling to 30 ℃.

The evaluation results of the adhesive sheet laminates 1-1 to 1-4 and shaped adhesive sheet laminates 1-1 to 1-4 obtained in examples and comparative examples are shown in table 1.

[ Table 1]

From the results shown in Table 1 and FIG. 4 and the test results thus far conducted, it was confirmed that the storage modulus E' (MB) at 30 ℃ was 5.0X 10 as shown in examples 1-1 to 1-3⁷～1.0×10¹⁰Pa, and a storage modulus E' (MA) at 100 ℃ of 1.0X 10⁶～2.0×10⁹The covering portion of Pa is formed by laminating on the adhesive material layer, and the uneven shape can be formed on the adhesive material layer with high accuracy.

On the other hand, as shown in comparative example 1-1, in the case of using a biaxially stretched homopolyPET film which is generally widely used as a release film, the storage modulus of the covering part exceeds 2.0X 10 even in a high temperature region⁹Pa, therefore, sufficient unevenness cannot be formed in the adhesive material layer even by thermoforming.

As is clear from the above, the storage modulus E' (MB) at 30 ℃ was adjusted to 5.0X 10⁷～1.0×10¹⁰Pa, and a storage modulus E' (MA) at 100 ℃ of 1.0X 10⁶～2.0×10⁹The covering portion of Pa is laminated on the adhesive material layer and molded, and a shaped adhesive sheet having a good uneven shape can be obtained.

It is also found that more accurate shaping can be achieved by using a more preferable adhesive sheet laminate in which the loss tangent tan δ (a) at 100 ℃ of the adhesive material layer satisfies the condition of 1.0 or more and the loss tangent tan δ (B) at 30 ℃ of the adhesive material layer satisfies the condition of less than 1.0.

Therefore, it was confirmed that by using the pressure-sensitive adhesive sheet laminate as described above, unevenness corresponding to a print height difference of an image display device as an adherend was accurately shaped, and a shaped pressure-sensitive adhesive sheet laminate for an image display device capable of being bonded with good adhesion without a gap between the pressure-sensitive adhesive sheet laminate and the adherend and without an adhesive material overflowing in the adherend such that a print portion has a narrow frame design could be produced.

When observing the peel strength, the conditions of heating and cooling when measuring the peel strength f (d), i.e., the conditions of heating at 100 ℃ for 5 minutes and then naturally cooling to 30 ℃, are typical heating and cooling conditions in the production of a shaped adhesive sheet laminate. In the above examples, the absolute values of the differences between the peeling forces f (c) and f (D) were all 0.1N/cm or less, and therefore it was confirmed that the peeling forces of the covering parts 1-a to 1-D in the shaped adhesive sheet laminate did not change from the peeling forces of the covering parts 1-a to 1-D in the adhesive sheet laminate.

[ example/comparative example set 2]

< cover 2-I >

As the cover 2-I of the adhesive sheet laminate in examples 2-1 to 2-4 and comparative example 2-1 (hereinafter, collectively referred to as "example/comparative example set 2"), a film was used in which a release layer (thickness: 2 μm) containing a silicone compound was laminated on one surface of a biaxially stretched isophthalic acid copolymerized PET film (thickness: 75 μm). The values of the respective storage moduli are shown in table 2.

< example 2-1>

(preparation of double-sided adhesive sheet)

1kg of an acrylic copolymer (2-a-1) (weight-average molecular weight: 23 ten thousand) as a (meth) acrylic copolymer (2-a), 90g of glycerol dimethacrylate (manufactured by Nichikura, product name: GMR) (2-b-1) as a crosslinking agent (2-b), and 15g of a mixture of 2,4, 6-trimethylbenzophenone and 4-methylbenzophenone (manufactured by Lanberti Co., product name: Escapure TZT) (2-c-1) as a photopolymerization initiator (2-c) were uniformly mixed, the acrylic copolymer (2-a-1) was obtained by randomly copolymerizing 15 parts by mass (18 mol%) of a polymethyl methacrylate macromonomer (Tg: 105 ℃) having a number-average molecular weight of 2400 and 81 parts by mass (75 mol%) of butyl acrylate (Tg: -55 ℃) and 4 parts by mass (7 mol%) of acrylic acid (Tg: 106 ℃), thereby preparing a resin composition 2-1 for an adhesive material layer. The glass transition temperature of the resulting resin composition was-5 ℃.

The obtained resin composition 2-1 was sandwiched between a release-treated PET film (product name: Diafil MRV-V06, manufactured by Mitsubishi resin corporation, thickness: 100 μm) and a cover part 2-I, and shaped into a sheet form so that the thickness of the resin composition 2-1 became 100 μm using a laminator to prepare an adhesive sheet laminate 2-1. The release layer side of the covering portion 2-I is disposed so as to be in contact with the resin composition 2-1.

The adhesive sheet laminate 2-1 thus obtained was thermoformed by the following procedure using a vacuum press molding machine (FKS-0632-20 type, manufactured by first Utility Co., Ltd.) and a molding die to prepare a shaped adhesive sheet laminate 2-1.

As shown in FIG. 5, the upper and lower dies were male dies having a length of 270mm, a width of 170mm and a thickness of 40mm, and the other upper and lower dies were aluminum flat plates having a length of 270mm, a width of 170mm and a thickness of 40 mm. As shown in FIG. 5, a convex portion having a vertical length of 187mm, a horizontal length of 125mm and a height of 1mm was provided at the center of the molding surface of the male mold, and further, 4 molding concave portions having a rectangular plan view (vertical length of 89mm, horizontal length of 58mm) having a depth of 25 μm, 50 μm, 75 μm and 100 μm were provided in the molding surface of the convex portion.

The surface of the cover part 2-I of the adhesive sheet laminate 2-1 was heated to 100 ℃ with an IR heater preheated to 400 ℃ and molded. That is, the storage modulus E' (MS) of the coating layer 2-I was 2.1X 10⁸Pa, storage modulus G' (SS) of the adhesive material layer of 2.9X 10²The mold was pressed for 5 seconds under a mold clamping pressure of 8MPa using a molding die having a die surface temperature cooled to 30 ℃ in a state of Pa, and the storage modulus E' (MF) of the coated portion 2-I was 2.8X 10⁹Pa, storage modulus G' (SF) of the adhesive material layer of 6.1X 10⁴The mold was opened in a Pa state to produce a shaped adhesive sheet laminate 2-1 having a surface shaped into an uneven shape.

The ratio E '(MF)/E' (MS) of the storage modulus E '(MS) of the covering portion 2-I at the start of molding to the storage modulus E' (MF) of the covering portion 2-I at the end of molding was 13.3.

Further, the ratio E '(MF)/G' (SF) of the storage modulus E '(MF) of the covering section 2-I at the end of molding to the storage modulus G' (SF) of the pressure-sensitive adhesive material layer at the end of molding was 4.6X 10⁴。

The loss tangent tan δ (SS) of the adhesive material layer at the start of molding was 4.8, and the loss tangent tan δ (SF) of the adhesive material layer at the end of molding was 0.6.

< examples 2 to 2>

The adhesive sheet laminate 2-1 used in example 2-1 was heated using an IR heater preheated to 400 ℃ until the surface of the covering section 2-I of the adhesive sheet laminate 2-2 became 110 ℃ and molded. That is, the storage modulus E' (MS) of the coating layer 2-I was 1.3X 10⁸Pa, storage modulus G' (SS) of the adhesive material layer of 9.6X 10¹The mold was pressed for 5 seconds under a mold clamping pressure of 8MPa using a molding die having a die surface temperature cooled to 30 ℃ in a state of Pa, and the storage modulus E' (MF) of the coated portion 2-I was 2.8X 10⁹Pa, storage modulus G' (SF) of the adhesive material layer of 6.1X 10⁴The mold was opened in a Pa state to produce an shaped adhesive sheet laminate 2-2 having a surface shaped into a concavo-convex shape.

The ratio E '(MF)/E' (MS) of the storage modulus E '(MS) of the covering portion 2-I at the start of molding to the storage modulus E' (MF) of the covering portion 2-I at the end of molding was 21.5.

Further, the ratio E '(MF)/G' (SF) of the storage modulus E '(MF) of the covering section 2-I at the end of molding to the storage modulus G' (SF) of the pressure-sensitive adhesive material layer at the end of molding was 4.6X 10⁴。

The loss tangent tan δ (SS) of the adhesive material layer at the start of molding was 8.2, and the loss tangent tan δ (SF) of the adhesive material layer at the end of molding was 0.6.

< examples 2 to 3>

The IR Heater used in example 2-1 was preheated to 400 deg.CThe adhesive sheet laminate 2-1 is heated until the surface of the cover section 2-I of the adhesive sheet laminate 2-3 becomes 90 ℃ and is molded. That is, the storage modulus E' (MS) of the coating layer 2-I was 3.5X 10⁸Pa, storage modulus G' (SS) of the adhesive material layer of 8.9X 10²The mold was pressed for 5 seconds under a mold clamping pressure of 8MPa using a molding die having a die surface temperature cooled to 30 ℃ in a state of Pa, and the storage modulus E' (MF) of the coated portion 2-I was 2.8X 10⁹Pa, storage modulus G' (SF) of the adhesive material layer of 6.1X 10⁴The mold was opened in a Pa state to produce a shaped adhesive sheet laminate 2-3 having a surface shaped into a concavo-convex shape.

The ratio E '(MF)/E' (MS) of the storage modulus E '(MS) of the covering portion 2-I at the start of molding to the storage modulus E' (MF) of the covering portion 2-I at the end of molding was 8.0.

Further, the ratio E '(MF)/G' (SF) of the storage modulus E '(MF) of the covering section 2-I at the end of molding to the storage modulus G' (SF) of the pressure-sensitive adhesive material layer at the end of molding was 4.6X 10⁴。

The loss tangent tan δ (SS) of the adhesive material layer at the start of molding was 2.7, and the loss tangent tan δ (SF) of the adhesive material layer at the end of molding was 0.6.

< examples 2 to 4>

The adhesive sheet laminate 2-1 obtained in example 2-1 was heated using an IR heater preheated to 400 ℃ until the surface of the cover part 2-I of the adhesive sheet laminate 2-4 became 70 ℃ and molded. That is, the storage modulus E' (MS) of the coating layer 2-I was 1.9X 10⁹Pa, storage modulus G' (SS) of the adhesive material layer of 6.4X 10³The mold was pressed for 5 seconds under a mold clamping pressure of 8MPa using a molding die having a die surface temperature cooled to 25 ℃ in a state of Pa, and the storage modulus E' (MF) of the coated portion 2-I was 2.8X 10⁹Pa, storage modulus G' (SF) of the adhesive material layer of 6.1X 10⁴The mold was opened in a Pa state to produce a shaped adhesive sheet laminate 2-4 having a surface shaped into a concavo-convex shape.

The ratio E '(MF)/E' (MS) of the storage modulus E '(MS) of the covering portion 2-I at the start of molding to the storage modulus E' (MF) of the covering portion 2-I at the end of molding was 1.4.

Further, the ratio E '(MF)/G' (SF) of the storage modulus E '(MF) of the covering section 2-I at the end of molding to the storage modulus G' (SF) of the pressure-sensitive adhesive material layer at the end of molding was 4.6X 10⁴。

The loss tangent tan δ (SS) of the adhesive material layer at the start of molding was 1.4, and the loss tangent tan δ (SF) of the adhesive material layer at the end of molding was 0.6.

< comparative example 2-1>

The adhesive sheet laminate 2-1 used in example 2-1 was heated to 60 ℃ on the surface of the covering part 2-I of the adhesive sheet laminate 2-5 using an IR heater preheated to 400 ℃ and molded. That is, the storage modulus E' (MS) of the coating layer 2-I was 2.4X 10⁹Pa, storage modulus G' (SS) of the adhesive material layer of 1.3X 10⁴The mold was pressed for 5 seconds under a mold clamping pressure of 8MPa using a molding die having a die surface temperature cooled to 25 ℃ in a state of Pa, and the storage modulus E' (MF) of the coated portion 2-I was 2.8X 10⁹Pa, storage modulus G' (SF) of the adhesive material layer of 6.1X 10⁴The mold was opened in a Pa state to produce a shaped adhesive sheet laminate 2-5 having a surface shaped into a concavo-convex shape.

The ratio E '(MF)/E' (MS) of the storage modulus E '(MS) of the covering portion 2-I at the start of molding to the storage modulus E' (MF) of the covering portion 2-I at the end of molding was 1.2.

Further, the ratio E '(MF)/G' (SF) of the storage modulus E '(MF) of the covering section 2-I at the end of molding to the storage modulus G' (SF) of the pressure-sensitive adhesive material layer at the end of molding was 4.6X 10⁴。

The loss tangent tan δ (SS) of the adhesive material layer at the start of molding was 1.1, and the loss tangent tan δ (SF) of the adhesive material layer at the end of molding was 0.6.

< measurement and evaluation methods >

The measurement method and evaluation method of various physical property values of the samples obtained in examples 2-1 to 2-4 and comparative example 2-1 will be described.

(modulus of elasticity of covering part)

Storage modulus E '(MS) and E' (MF) of the covers 2-I were determined as follows: the cut pieces were 50mm in length and 4mm in width, and measured by using a dynamic viscoelastometer (アイティー Kogyo DVA-200) with a chuck pitch of 25mm and a strain of 1%. The measurement is carried out under the conditions that the measurement temperature range is-50 ℃ to 150 ℃, the frequency is 1Hz, and the temperature rise speed is 3 ℃/min.

The storage modulus value at the molding start temperature in each of examples and comparative examples was designated as E '(MS), and the storage modulus value at the molding end temperature was designated as E' (MF).

In example 2-1, the storage modulus E' (MS) in example 2-1 was 100 ℃ because the temperature at the start of molding was 100 ℃.

In addition, since the temperature at the end of molding was 30 ℃ in each of example/comparative example set 2, the E '(MF) was also the same as the storage modulus E' (MB) at 30 ℃ in any of example/comparative example set 2.

(modulus of elasticity of adhesive material layer)

The adhesive material layers obtained in group 2 of example/comparative example were stacked to a thickness of 1mm, and measured using a rheometer (MARSII, manufactured by Thermo Fisher Scientific Co.). The measurement is carried out under the conditions that the measurement temperature range is-50 ℃ to 150 ℃, the frequency is 1Hz, and the temperature rise speed is 3 ℃/min.

With respect to the obtained data, the value of storage modulus at 100 ℃ is G ' (SA), the value of loss modulus is G "(SA), the value of storage modulus at 30 ℃ is G ' (SB), the value of loss modulus is G" (SB), and the value of G "/G ' under each temperature condition is taken as the loss tangent tan δ (SA, SB) of each adhesive material layer.

On the other hand, the adhesive material layers obtained in example/comparative example group 2 were stacked to a thickness of 1mm with respect to storage moduli G '(SA) and G' (SB) of the adhesive material layers, and measured using a rheometer (MARSII manufactured by Thermo Fisher Scientific corporation). The measurement is carried out under the conditions that the measurement temperature range is-50 ℃ to 150 ℃, the frequency is 1Hz, and the temperature rise speed is 3 ℃/min.

With respect to the obtained data, the value of storage modulus at each molding start temperature in group 2 of example/comparative example was G ' (SS), the value of loss modulus was G "(SS), the value of storage modulus at each molding end temperature was G ' (SF), the value of loss modulus was G" (SF), and the value of G "/G ' under each temperature condition was defined as loss tangent tan δ (SS, SF) of each adhesive material layer.

(gel fraction)

The gel fraction of the adhesive material layer was determined as follows: the adhesive material layers obtained in group 2 of examples/comparative examples were each measured by collecting an amount of about 0.05g, wrapping the adhesive material layers in a bag shape with a SUS mesh (#200) whose mass (X) was measured in advance, folding the bag mouth to seal the bag mouth, measuring the mass (Y) of the wrapping, immersing the bag in 100ml of ethyl acetate, storing the bag in a dark place at 23 ℃ for 24 hours, taking out the wrapping, heating the bag at 70 ℃ for 4.5 hours to evaporate the attached ethyl acetate, measuring the mass (Z) of the dried wrapping, and substituting the obtained mass into the following formula.

Gel fraction [% ] [ (Z-X)/(Y-X) ] × 100

(moldability)

The coating portion I of the shaped adhesive sheet laminate having the irregularities formed obtained in group 2 of example/comparative example was peeled off, and the heights of the recesses corresponding to the print height difference and the projections corresponding to the display surface were measured in a non-contact manner using a scanning white interference microscope.

The height h of the convex portion (and the edge portion of the concave portion) of the molded article was measured at a depth of 100 μm with respect to the mold, and a case where the transfer ratio derived from the following calculation formula was 50% or more was evaluated as "o", and a case where the transfer ratio was less than 50% was evaluated as "x".

Transfer ratio (%) < h (height of molded article)/100 (depth of mold) × 100

(Peel force)

The adhesive sheet laminate produced in group 2 of example/comparative example was cut out to have a length of 150mm and a width of 50mm, and a 180 ° peel test was performed at a test speed of 300 mm/min on the interface between the cover 2-I and the adhesive material layer.

The peel force in the environment of 30 ℃ was defined as F (C), and the peel force after heating at 100 ℃ for 5 minutes and then naturally cooling to 30 ℃ was defined as F (D), and these values were defined as the peel force of the covering section 2-I.

The evaluation results of the shaped adhesive sheet laminates 2-1 to 2-5 obtained in examples 2-1 to 2-4 and comparative example 2-1 are shown in Table 2.

[ Table 2]

From the results shown in Table 2 and FIG. 4 and the test results thus far conducted, it was confirmed that the storage modulus E' (MS) of the covering part 2-I at the time of starting the molding was 1.0X 10 as shown in examples 2-1 to 2-4⁶～2.0×10⁹Pa and a storage modulus E' (MF) of the covering section 2-I at the end of molding of 5.0X 10⁷～1.0×10¹⁰Pa is adjusted and formed, so that the uneven shape can be formed on the adhesive material layer with high precision.

On the other hand, as shown in comparative example 2-1, the storage modulus E' (MS) of the covering section 2-I at the start of molding was more than 2.0X 10⁹Pa is not enough unevenness to be formed in the adhesive material layer even by thermoforming.

As is clear from the above, the storage modulus E' (MS) of the covering section 2-I at the start of molding was set to 1.0X 10⁶～2.0×10⁹Pa and a storage modulus E' (MF) of the covering section 2-I at the end of molding of 5.0X 10⁷～1.0×10¹⁰The pattern Pa is adjusted and molded, and a shaped adhesive sheet having a good uneven shape can be obtained.

It is also found that more accurate shaping can be achieved by adjusting and molding the pressure-sensitive adhesive layer so that the loss tangent tan δ (SS) of the pressure-sensitive adhesive layer at the start of molding satisfies the condition of 1.0 or more and the loss tangent tan δ (SF) of the pressure-sensitive adhesive layer at the end of molding satisfies the condition of less than 1.0.

Therefore, it was confirmed that by using the pressure-sensitive adhesive sheet laminate as described above, unevenness corresponding to a print height difference of an image display device as an adherend was accurately shaped, and a shaped pressure-sensitive adhesive sheet laminate for an image display device capable of being bonded with good adhesion without a gap between the pressure-sensitive adhesive sheet laminate and the adherend and without an adhesive material overflowing in the adherend such that a print portion has a narrow frame design could be produced.

When observing the peel strength, the conditions of heating and cooling when measuring the peel strength f (d), i.e., the conditions of heating at 100 ℃ for 5 minutes and then naturally cooling to 30 ℃, are typical heating and cooling conditions in the production of a shaped adhesive sheet laminate. In the above examples, the absolute values of the differences between the peeling forces f (c) and f (d) were all 0.1N/cm or less, and therefore, it was confirmed that the peeling forces were hardly changed before and after heating.

Further, the adhesive sheet laminate was heated to give a storage modulus E' (MS) of 1.0X 10 in the coated portion 2-I⁶～2.0×10⁹The molding was started in a state of Pa, and the storage modulus E' (MF) of the covering portion 2-I was 5.0X 10⁷～1.0×10¹⁰By finishing the molding in a state of Pa, an uneven shape conforming to the uneven portion on the surface of the adherend can be formed on the surface of the pressure-sensitive adhesive layer with high accuracy.

[ example/comparative example group 3]

< cover 3-I >

As the cover 3-I of the adhesive sheet laminates in examples 3-1 to 3-3 and comparative examples 3-1 to 3-2 (hereinafter, collectively referred to as "example/comparative example group 3"), a film was used in which a release layer (thickness: 2 μm) containing a silicone compound was laminated on one surface of a biaxially stretched isophthalic acid copolymerized PET film (thickness: 75 μm). The values of the respective storage moduli are shown in table 3.

< example 3-1>

(preparation of double-sided adhesive sheet)

1kg of an acrylic copolymer (3-a-1) (weight-average molecular weight: 23 ten thousand) as a (meth) acrylic copolymer (3-a), 90g of glycerol dimethacrylate (manufactured by Nichikura, product name: GMR) (3-b-1) as a crosslinking agent (3-b), and 15g of a mixture of 2,4, 6-trimethylbenzophenone and 4-methylbenzophenone (manufactured by Lanberti Co., product name: Escapure TZT) (3-c-1) as a photopolymerization initiator (3-c) were uniformly mixed, the acrylic copolymer (3-a-1) was obtained by randomly copolymerizing 15 parts by mass (18 mol%) of a polymethyl methacrylate macromonomer (Tg: 105 ℃) having a number-average molecular weight of 2400 and 81 parts by mass (75 mol%) of butyl acrylate (Tg: -55 ℃) and 4 parts by mass (7 mol%) of acrylic acid (Tg: 106 ℃), thereby preparing a resin composition 3-1 for an adhesive material layer. The glass transition temperature of the resulting resin composition was-5 ℃.

The obtained resin composition 3-1 was sandwiched between a release-treated PET film (product name: Diafil MRV-V06, manufactured by Mitsubishi resin corporation, thickness: 100 μm) and a cover part 3-I, and shaped into a sheet form so that the thickness of the resin composition 3-1 became 100 μm using a laminator to prepare an adhesive sheet laminate 3-1. The release layer side of the covering portion 3-I is disposed so as to be in contact with the resin composition 3-1.

The adhesive sheet laminate 3-1 thus obtained was thermoformed using a vacuum press molding machine (FKS-0632-20 type, manufactured by first Utility Co., Ltd.) and a molding die by the following process to prepare a shaped adhesive sheet laminate 3-1.

As shown in FIG. 5, the upper and lower dies were male dies having a length of 270mm, a width of 170mm and a thickness of 40mm, and the other upper and lower dies were aluminum flat plates having a length of 270mm, a width of 170mm and a thickness of 40 mm. As shown in FIG. 5, a convex portion having a vertical length of 187mm, a horizontal length of 125mm and a height of 1mm was provided at the center of the molding surface of the male mold, and further, 4 molding concave portions having a rectangular plan view (vertical length of 89mm, horizontal length of 58mm) having a depth of 25 μm, 50 μm, 75 μm and 100 μm were provided in the molding surface of the convex portion.

The surface of the covering part 3-I of the adhesive sheet laminate 3-1 was heated to 100 ℃ by an IR heater preheated to 400 ℃ and a molding die for cooling the die surface temperature to 30 ℃ was used for the adhesive sheet laminate 3-1 in the heated state, and the die was opened after press molding was performed for 5 seconds under a die clamping pressure of 8MPa to prepare a shaped adhesive sheet laminate 3-1 having a surface shaped into irregularities.

< examples 3 and 2>

The adhesive sheet laminate 3-1 used in example 3-1 was heated by an IR heater preheated to 400 ℃ until the surface of the covering portion 3-I of the adhesive sheet laminate 3-2 became 70 ℃, and the adhesive sheet laminate 3-1 in this heated state was press-molded for 5 seconds using a molding die having a die surface temperature cooled to 30 ℃ under a die clamping pressure of 8MPa, and then the die was opened to prepare a shaped adhesive sheet laminate 3-2 having a surface shaped into irregularities.

< examples 3 to 3>

The adhesive sheet laminate 3-1 used in example 3-1 was heated by an IR heater preheated to 400 ℃ until the surface of the covering portion 3-I of the adhesive sheet laminate 3-3 became 100 ℃, and the adhesive sheet laminate 3-1 in this heated state was press-molded for 5 seconds under a mold clamping pressure of 8MPa using a molding die having a die surface temperature adjusted to 50 ℃ and then opened to prepare a shaped adhesive sheet laminate 3-3 having a surface shaped into convexes and concaves.

< comparative example 3-1>

The adhesive sheet laminate 3-1 used in example 3-1 was heated by an IR heater preheated to 400 ℃ until the surface of the covering portion 3-I of the adhesive sheet laminate 3-5 became 60 ℃, and the adhesive sheet laminate 3-1 in this heated state was press-molded for 5 seconds using a molding die having a die surface temperature cooled to 30 ℃ under a die clamping pressure of 8MPa, and then the die was opened to prepare a shaped adhesive sheet laminate 3-4 having a surface shaped into irregularities.

< comparative example 3-2>

The adhesive sheet laminate 3-1 used in example 3-1 was heated by an IR heater preheated to 400 ℃ until the surface of the covering portion 3-I of the adhesive sheet laminate 3-5 became 100 ℃, and the adhesive sheet laminate 3-1 in this heated state was press-molded for 5 seconds under a mold clamping pressure of 8MPa using a molding die having a die surface temperature adjusted to 80 ℃ and then opened to prepare a shaped adhesive sheet laminate 3-5 having a surface shaped into convexes and concaves.

< measurement and evaluation methods >

The measurement method and evaluation method of various physical property values of the samples obtained in examples 3-1 to 3-3 and comparative examples 3-1 to 3-2 will be described.

(modulus of elasticity of covering part)

The storage modulus of the cover 3-I was determined as follows: the cut pieces were 50mm in length and 4mm in width, and measured by using a dynamic viscoelastometer (アイティー Kogyo DVA-200) with a chuck pitch of 25mm and a strain of 1%. The measurement is carried out under the conditions that the measurement temperature range is-50 ℃ to 150 ℃, the frequency is 1Hz, and the temperature rise speed is 3 ℃/min.

In the obtained data, the storage modulus of the coated part 3-I at 30 ℃ was designated as E '(MB), and the storage modulus of the coated part 3-I at 100 ℃ was designated as E' (MA).

(modulus of elasticity of adhesive material layer)

The adhesive material layers obtained in group 3 of example/comparative example were stacked to a thickness of 1mm, and measured using a rheometer (MARSII, manufactured by Thermo Fisher Scientific Co.). The measurement is carried out under the conditions that the measurement temperature range is-50 ℃ to 150 ℃, the frequency is 1Hz, and the temperature rise speed is 3 ℃/min.

With respect to the obtained data, the value of storage modulus at 100 ℃ is G ' (SA), the value of loss modulus is G "(SA), the value of storage modulus at 30 ℃ is G ' (SB), the value of loss modulus is G" (SB), and the value of G "/G ' under each temperature condition is taken as the loss tangent tan δ (SA, SB) of each adhesive material layer.

(moldability)

The coating portion I of the shaped adhesive sheet laminate having the irregularities formed obtained in group 3 of examples/comparative examples was peeled off, and the heights of the recesses corresponding to the print height difference and the projections corresponding to the display surface were measured in a non-contact manner using a scanning white interference microscope.

The height h of the convex portion (and the edge portion of the concave portion) of the molded article was measured at a depth of 100 μm with respect to the mold, and the case where the transfer ratio derived from the following calculation formula was 50% or more was evaluated as "o", and the case where the transfer ratio was less than 50% was evaluated as "x".

Transfer ratio (%) < h (height of molded article)/100 (depth of mold) × 100

(warping/waving)

Squares having a length of 100mm were cut out from the adhesive sheet laminate produced under the respective molding conditions of group 3 of examples/comparative examples, and the heights of the respective apexes were measured. The heights of the resulting 4 points were averaged and the value was taken as the warpage. The case where the height of the warpage was less than 10mm was determined as "O", and the case where the height was 10mm or more was determined as "X".

(Peel force)

The adhesive sheet laminate produced in group 3 of example/comparative example was cut out to have a length of 150mm and a width of 50mm, and a 180 ° peel test was performed at a test speed of 300 mm/min on the interface between the cover part 3-I and the adhesive material layer.

The peel force of the covering part 3-I was defined as F (C) for the peel force in the environment of 30 ℃ and F (D) for the peel force after heating at 100 ℃ for 5 minutes and then naturally cooling to 30 ℃.

The evaluation results of the shaped adhesive sheet laminates 3-1 to 3-5 obtained in examples 3-1 to 3-3 and comparative examples 3-1 to 3-2 are shown in Table 3.

[ Table 3]

From the results in table 3 and the test results thus far carried out, it was confirmed that the adhesive material layer can be shaped with high accuracy into the uneven shape by starting the molding with the surface temperature of the covering part 3-I being 70 to 180 ℃ and finishing the molding after the surface temperature of the covering part 3-I is less than 60 ℃ and taking out the molded article from the mold as shown in examples 3-1 to 3-3.

On the other hand, as shown in comparative example 3-1, when the temperature of the covering section 3-I at the start of molding is less than 70 ℃, sufficient unevenness cannot be formed in the adhesive material layer even by thermoforming.

It is also found that, as shown in comparative example 3-2, when the surface temperature of the covering part 3-I is 70 ℃ or higher at the time of completion of molding and removal of the molded article from the mold, warpage and waviness of the molded article occur due to thermal shrinkage of the sheet, which is not preferable.

From the above, in order to perform the uneven forming with higher accuracy, it is preferable to perform the forming such that the forming is started in a state where the surface temperature of the covering portion 3-I is 70 to 180 ℃, and the forming is finished after the surface temperature of the covering portion 3-I is less than 60 ℃, and the formed product is taken out from the mold.

Therefore, it was confirmed that by using the pressure-sensitive adhesive sheet laminate as described above, unevenness corresponding to a print height difference of an image display device as an adherend was accurately shaped, and a shaped pressure-sensitive adhesive sheet laminate for an image display device capable of being bonded with good adhesion without a gap between the pressure-sensitive adhesive sheet laminate and the adherend and without an adhesive material overflowing in the adherend such that a print portion has a narrow frame design could be produced.

When observing the peel force, the heating and cooling conditions for measuring the peel force f (d), i.e., the conditions of heating at 100 ℃ for 5 minutes and then naturally cooling to 30 ℃, are typical heating and cooling conditions for producing a shaped adhesive sheet laminate. In the above examples, the absolute values of the differences between the peeling forces f (c) and f (d) were all 0.1N/cm or less, and therefore, it was confirmed that the peeling forces were hardly changed before and after heating.

[ group 4 of examples ]

The method for producing the polyester raw material used in examples 4-1 to 4-5 (hereinafter, collectively referred to as "group 4 of examples") is as follows.

(method for producing polyester 4-A)

100 parts of dimethyl terephthalate, 70 parts of ethylene glycol and 0.07 part of calcium acetate monohydrate are taken into a reactor, methanol is distilled off while heating and raising the temperature, the ester exchange reaction is carried out, after the reaction is started, the temperature is raised to 230 ℃ for about 4 half an hour, and the ester exchange reaction is substantially finished.

Then, 0.04 parts of phosphoric acid and 0.035 parts of antimony trioxide were added thereto, and polymerization was carried out by a conventional method. That is, the reaction temperature was gradually increased to finally reach 280 ℃ and the pressure was gradually decreased to finally reach 0.05 mmHg. After 4 hours, the reaction was terminated, and the polyester 4-A was obtained by flaking according to a conventional method. The intrinsic viscosity IV of the resulting polyester chips was 0.70 dl/g.

(method for producing polyester 4-B)

Polyester 4-B was obtained in the same manner as for polyester A except that 78 mol% of terephthalic acid and 22 mol% of isophthalic acid were used as dicarboxylic acid units in the above-mentioned process for producing polyester 4-A. The intrinsic viscosity IV of the resulting polyester chips was 0.70 dl/g.

(method for producing polyester 4-C)

When the polyester 4-A was produced, 6000ppm of amorphous silica having an average particle size of 3 μm was added to prepare a polyester 4-C.

(method for producing polyester 4-D)

In the production of the polyester 4-A, 6000ppm of amorphous silica having an average particle diameter of 4 μm was added to prepare a polyester 4-D.

[ example 4-1]

The raw materials obtained by mixing the polyesters 4-B, 4-A and 4-D at the ratios of 65 wt%, 30 wt% and 5 wt%, respectively, were melt-extruded by a melt extruder to obtain a single-layer amorphous sheet.

Subsequently, a sheet was co-extruded on a cooled casting drum and cooled to solidify, to obtain a non-oriented sheet. Subsequently, the film was stretched 3.4 times at 80 ℃ in the machine direction (longitudinal direction), and then subjected to a preheating step in a tenter and stretched 3.9 times at 80 ℃ in the direction perpendicular to the machine direction (transverse direction). After biaxial stretching, heat treatment was carried out at 185 ℃ for 3 seconds, and then relaxation treatment was carried out at 6.4% in the width direction to obtain a polyester film having a thickness of 50 μm. The evaluation results are shown in table 4 below.

Examples 4 and 2 and examples 4 and 3

Polyester films were obtained in the same manner as in example 4-1, except that the conditions shown in Table 4 below were changed. The evaluation results are shown in table 4 below.

[ examples 4 to 4]

The raw materials obtained by mixing the polyesters 4-A and 4-C at the ratios of 86 wt% and 14 wt%, respectively, were used as raw materials for the surface layer, and the raw materials obtained by mixing the polyesters 4-B and 4-A at the ratios of 45 wt% and 55 wt%, respectively, were used as raw materials for the intermediate layer. Melt extrusion was carried out by different melt extruders to obtain 2 kinds of 3-layer laminated (skin layer/intermediate layer/skin layer) amorphous sheets.

Next, a sheet was co-extruded on a cooled casting drum and cooled to solidify, thereby obtaining a non-oriented sheet. Subsequently, the resultant was stretched 3.4 times at 82 ℃ in the Machine Direction (MD), and then further subjected to a preheating step in a tenter to be stretched 3.9 times at 110 ℃ in the direction (width direction, TD) perpendicular to the machine direction. After biaxial stretching, heat treatment was carried out at 210 ℃ for 3 seconds, and then relaxation treatment was carried out at 2.4% in the width direction to obtain a polyester film having a thickness of 50 μm. The evaluation results are shown in table 4 below.

[ examples 4 to 5]

Polyester films were obtained in the same manner as in example 4-4, except that the conditions shown in Table 4 below were changed. The evaluation results are shown in table 4 below.

< measurement and evaluation methods >

The measurement method and evaluation method of various physical property values of the samples obtained in group 4 of the examples will be described.

(1) Storage modulus (E')

For the films obtained in group 4 of the examples, samples of 30mm in the longitudinal direction × 5mm in the width direction were selected so that the longitudinal direction was the machine direction. Next, the sample was held and fixed by a chuck having a gap of 20mm using a dynamic viscoelastometer ("DVA-220" manufactured by アイティー division, Yu Ltd.), and then the temperature was raised from room temperature to 200 ℃ at a temperature raising rate of 10 ℃ per minute, and the storage modulus was measured at a frequency of 10 Hz. From the data obtained, the storage modulus at 100 ℃ was read.

(2) Heat shrinkage rate

From the widthwise central position of the film obtained in group 4 of example, a sample was cut into a short strip (15mm wide × 150mm long) so that the lengthwise direction of the sample became the measuring direction, and heat-treated in a tension-free state at 120 ℃ for 5 minutes to measure the length of the sample before and after the heat treatment, and the heat shrinkage (%) of the film was calculated by the following formula. In the following formula, a represents the sample length before heat treatment, and b represents the sample length after heat treatment.

Heat shrinkage (%) of [ (a-b)/a ] x 100

(3) Amount of oligomer on surface of film after heat treatment

For the films obtained in group 4 of the examples, the polyester films were treated for 10 minutes in a hot air circulation oven at 180 ℃ under a nitrogen atmosphere. The surface of the polyester film after the heat treatment was brought into contact with DMF (dimethylformamide) for 3 minutes to dissolve the oligomer precipitated on the surface. The above-mentioned operation can be performed by a method described in an elution device used in a single-sided elution method in an elution test or an autonomous standard relating to packaging of a food container made of synthetic resin such as polyolefin.

Then, the resulting DMF was subjected to liquid chromatography (Shimadzu LC-2010) to determine the amount of oligomer in the DMF, which was adjusted in concentration by dilution or the like as necessary, and this value was divided by the area of the film in contact with the DMF to obtain the amount of oligomer on the surface of the film (mg/cm)²)。

The amount of oligomers in DMF was determined from the peak area ratio of the peak area of the standard sample to the peak area of the measurement sample (absolute calibration curve method).

For the preparation of the standard sample, the oligomer (cyclic trimer) previously fractionated was accurately weighed and dissolved in an accurately weighed amount of DMF to prepare the sample. The concentration of the standard sample is preferably in the range of 0.001 to 0.01 mg/ml.

(4) Suitability for molding

1kg of an acrylic copolymer (weight-average molecular weight: 23 ten thousand) having a number-average molecular weight of 2400 (polymethyl methacrylate macromonomer (Tg: 105 ℃ C.) 15 parts by mass (18 mol%) and butyl acrylate (Tg: 55 ℃ C.) (75 mol%) and acrylic acid (Tg: 106 ℃ C.) 4 parts by mass (7 mol%) as a (meth) acrylic copolymer randomly copolymerized, 90g of glycerol dimethacrylate (manufactured by Nichiyan Co., Ltd., product name: GMR) (b-1) as a crosslinking agent, and 15g of a mixture of 2,4, 6-trimethylbenzophenone and 4-methylbenzophenone (manufactured by Lanberti Co., product name: Esacure TZT) as a photopolymerization initiator were uniformly mixed to prepare a resin composition for an adhesive sheet.

The obtained resin composition was sandwiched from the top and bottom by2 sheets of release films obtained from the polyester film shown in group 4 of example (the top and bottom were combined and sandwiched by the same release films), and shaped into a sheet form so that the thickness of the resin composition became 100 μm using a laminator, to produce an adhesive sheet laminate. The release layer side of the polyester film is disposed so as to be in contact with the resin composition.

The obtained adhesive sheet laminate was thermoformed using a vacuum press molding machine (FKS-0632-20 type, manufactured by first Utility Co., Ltd.) by the following process to prepare a shaped adhesive sheet laminate. Specifically, an shaped adhesive sheet laminate having a surface formed into an uneven shape was produced by heating the surface of the adhesive sheet laminate to 100 ℃ with an IR heater preheated to 400 ℃, followed by press molding for 5 seconds with a mold for molding cooled to 25 ℃ under a mold clamping pressure of 8 MPa.

The polyester film of the shaped adhesive sheet laminate having irregularities shaped was peeled off, and the heights of the recesses and projections of the shaped adhesive sheet were measured in a noncontact manner using a scanning white interference microscope, and the height of the molded article was designated as h.

The height h of the convex portion of the molded article was measured at a depth of 100 μm with respect to the mold, and the case where the transfer ratio derived from the following calculation formula was 70% or more was evaluated as "good", the case where the transfer ratio was 50% or more and less than 70% was evaluated as "Δ", and the case where the transfer ratio was less than 50% was evaluated as "x".

Transfer ratio (%) < h (height of molded article)/100 (depth of mold) × 100

(5) Appearance of the adhesive layer (wrinkle)

The appearance of the adhesive layer laminate obtained by the method described in (4) and before press molding was evaluated by the following evaluation methods.

< evaluation method >

O: the laminate was laminated without wrinkles, and maintained a good appearance.

X: the film had wrinkles, and the wrinkles were transferred to the adhesive layer, and were not usable as a product.

[ Table 4]

Industrial applicability

The shaped adhesive sheet laminate of 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, a tablet, or the like.

The adhesive sheet laminate and the coating film of the present invention can be suitably used for forming such a shaped adhesive sheet laminate.

Claims (11)

1. A method for producing a shaped adhesive sheet laminate comprising an adhesive material layer and a covering section I formed by laminating the adhesive material layer on one surface thereof in a peelable manner, wherein the adhesive material layer has a configuration in which a concave section, a convex section or a concave-convex section called a "concave-convex section on the surface of the adhesive material layer" is formed on one surface of the adhesive material layer,

a shaped adhesive sheet laminate is produced by heating an adhesive sheet laminate comprising an adhesive material layer and a cover section I formed by laminating the adhesive material layer on one side in a peelable manner, molding the heated adhesive sheet laminate, and cooling the molded adhesive sheet laminate,

the pressure-sensitive adhesive sheet laminate was heated to a storage modulus E' (MS) of 1.0X 10 in the cover section I⁶～2.0×10⁹The molding was started in a state of Pa, and the storage modulus E' (MF) of the covering section I was 5.0X 10⁷～1.0×10¹⁰The molding is finished in a state of Pa.

2. A method for producing a shaped adhesive sheet laminate according to claim 1, wherein the adhesive sheet laminate comprising an adhesive material layer and a cover section I formed by laminating the adhesive material layer on one surface thereof in a peelable manner is heated, and the heated adhesive sheet laminate is molded using a cooled mold.

3. A method for producing a shaped adhesive sheet laminate according to claim 1, wherein the storage modulus E '(MS) of the cover section I at the start of molding and the storage modulus E' (MF) of the cover section I at the end of molding satisfy the following relational expression (1),

(1)··E’(MF)/E’(MS)≥1.3。

4. a method for producing a shaped adhesive sheet laminate according to claim 1, wherein the adhesive sheet laminate is heated so that the storage modulus E' (MS) of the cover section I is 1.0X 10⁶～2.0×10⁹Pa, and the storage modulus G' (SS) of the adhesive material layer is less than 1.0X 10⁴The molding is started in the state of Pa,

the storage modulus E' (MF) in the covering section I was 5.0X 10⁷～1.0×10¹⁰Pa, and a storage modulus G' (SF) of the adhesive material layer of 1.0X 10⁴And finishing the forming under the state of Pa or above.

5. A method for producing a shaped adhesive sheet laminate according to claim 1, wherein the storage modulus E '(MF) of the covering section I at the end of molding and the storage modulus G' (SF) of the adhesive material layer at the end of molding satisfy the following relational expression (2),

(2)E’(MF)/G’(SF)≤1.0×10⁷。

6. a method for producing a shaped adhesive sheet laminate according to claim 1, wherein the cover section I comprises a cover base layer and a release layer,

the covering base material layer has a layer containing 1 resin or 2 or more resins selected from the group consisting of unstretched polyester, stretched polyester, copolymerized polyester, unstretched polyolefin, stretched polyolefin and copolymerized polyolefin as a main component.

7. A method for producing a shaped adhesive sheet laminate according to claim 1, wherein the adhesive material layer is formed from a resin composition containing a (meth) acrylic copolymer (a), a crosslinking agent (b) and a photopolymerization initiator (c).

8. A method for producing a shaped adhesive sheet laminate according to claim 1, wherein the adhesive material layer has concave portions, convex portions, or concave-convex portions called "uneven portions on the surface of the adhesive material layer" on the front and back surfaces, and the adhesive material layer is laminated on the adhesive material layer by the adhesive material layer,

the covering section I is in close contact with the front and back surfaces of the adhesive material layer, and has recesses, projections, or recesses and projections, which are called "covering section surface recesses and projections", on the front and back surfaces, and has projections, recesses, or projections and recesses, which are called "covering section back surface recesses and projections, which are called" covering section surface recesses and projections ", on the front and back surfaces opposite to the front and back surfaces, and which are formed with recesses and projections corresponding to the covering section surface recesses and projections, recesses, or projections and recesses, which are called" covering section back surface recesses and projections, on the other front and back surfaces.

9. A method for producing a shaped adhesive sheet laminate according to claim 8, wherein the adhesive material layer is a double-sided adhesive sheet for bonding 2 adherends,

the adhesive material layer surface irregularities conform to recesses or projections or irregularities called "adherend surface irregularities" in the adherend surface of the arbitrary adherend.

10. A method for producing a shaped adhesive sheet laminate according to claim 9, wherein the arbitrary adherend is any one selected from the group consisting of a surface protection panel, a touch panel, and an image display panel.

11. A method for producing a shaped adhesive sheet laminate according to claim 1, wherein the adhesive sheet laminate is heated to form a concavo-convex shape on at least one surface of the adhesive sheet by press molding, vacuum molding, pressure-air molding or roll molding.

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