JP6356564B2 - Adhesive sheet - Google Patents

Description

  The present invention relates to a temporary fixing method and an adhesive sheet.

In the manufacturing process of organic thin film transistors (organic TFTs), light emitting elements (LEDs), flat panel displays (FPDs), etc., flexible substrates (resin films, etc.) are made of glass from the viewpoint of ease of processing and transport in the manufacturing process. In some cases, it is temporarily fixed to a rigid support substrate such as.
As a method for temporarily fixing in this way, a temporary fixing method using an adhesive sheet has been proposed. However, in the above manufacturing process, heat treatment is often performed for the purpose of sintering or controlling the orientation of a semiconductor layer or conductor (metal layer) provided on a flexible substrate. In such a case, when peeling a flexible substrate, there exists a tendency for the peeling force of an adhesive sheet to become high. As a result, there is a problem that an excessive force is applied to the flexible substrate, and the semiconductor layer and the conductor on the flexible substrate are damaged. In addition, depending on the pressure-sensitive adhesive sheet, there is also a problem that the flexible substrate is deformed by foaming or the like by heat treatment, and a load is applied to the semiconductor layer or the conductor to easily cause a defect.
In order to solve the above-mentioned problems, a method of temporarily fixing two substrates using an easily peelable pressure-sensitive adhesive sheet whose adhesive force can be reversibly controlled by heat has been proposed (see Patent Documents 1 and 2). .

JP 2011-153203 A JP 2011-219617 A

  When the easily peelable pressure-sensitive adhesive sheet described in Patent Document 1 or 2 is used, the peel strength of the pressure-sensitive adhesive sheet can be reduced if the flexible substrate is peeled off at a predetermined temperature or lower even if heat treatment is performed. Therefore, it is possible to reduce the load on the semiconductor layer and the conductor on the flexible substrate. However, since the pressure-sensitive adhesive remains on the support substrate after the flexible substrate is peeled off, it is difficult to remove and clean the pressure-sensitive adhesive, and thus it is difficult to reuse the support substrate.

  Therefore, an object of the present invention is to provide a temporary fixing method and an adhesive sheet in which the substrate after temporary fixing can be easily peeled and the adhesive can be easily removed from the substrate used for temporary fixing. .

The temporary fixing method according to one aspect of the present invention includes an energy ray-curable pressure-sensitive adhesive layer that is cured by energy rays and decreases the peeling force between two substrates, and a temperature-sensitive type in which the peeling force changes due to a temperature change. An adhesive layer is provided, and the two substrates are temporarily fixed.
According to this configuration, after the two substrates are temporarily fixed and processed, the two pressure-sensitive adhesive layers and the two substrates can be easily separated as follows. That is, after the energy beam curable pressure-sensitive adhesive layer is irradiated with energy rays, the peeling force of the energy beam curable pressure-sensitive adhesive layer decreases, so the substrate can be easily peeled off from the energy beam curable pressure-sensitive adhesive layer. it can. On the other hand, if the temperature is set to a predetermined temperature or lower, for example, the peeling force of the temperature-sensitive pressure-sensitive adhesive layer decreases, so that the substrate can be easily peeled from the temperature-sensitive pressure-sensitive adhesive layer. It should be noted that it is difficult to remove or clean the pressure sensitive adhesive layer alone after temporary fixing. However, if the energy ray curable pressure-sensitive adhesive layer is irradiated with energy rays, the energy ray curable pressure-sensitive adhesive layer becomes a thin film capable of supporting the temperature-sensitive pressure-sensitive adhesive layer. And by peeling this thin film from a board | substrate, the temperature-sensitive adhesive layer currently carry | supported can be peeled from a board | substrate together, and an adhesive can be removed from a board | substrate.

In the temporary fixing method according to an aspect of the present invention, the temperature-sensitive pressure-sensitive adhesive layer contains a side-chain crystalline polymer, and a peel strength is reduced at a temperature equal to or lower than the melting point of the side-chain crystalline polymer. It is preferable that
According to this configuration, if the melting point of the side chain crystalline polymer is not higher than the melting point, the peeling force of the temperature-sensitive pressure-sensitive adhesive layer is reduced, so that the substrate can be easily peeled from the temperature-sensitive pressure-sensitive adhesive layer.

In the temporary fixing method according to one aspect of the present invention, it is preferable that one of the two substrates is a flexible substrate and the other substrate is a rigid substrate.
According to this configuration, by temporarily fixing the flexible substrate to the rigid substrate, it is possible to easily process and transport various products in the manufacturing process. And the flexible substrate after a process can be peeled easily, and an energy-beam curable adhesive layer and a temperature-sensitive adhesive layer can be easily peeled from the rigid board | substrate after peeling a flexible substrate. Therefore, the rigid substrate used as the support substrate can be reused.

In the temporary fixing method according to an aspect of the present invention, it is preferable that at least one of the two substrates is a transparent substrate that transmits the energy rays.
According to this structure, when peeling the board | substrate after processing, an energy-beam curable adhesive layer and a board | substrate can be peeled first. That is, when both substrates are not transparent substrates, the energy beam curable pressure sensitive adhesive is not after removing one substrate and exposing the temperature sensitive pressure sensitive adhesive layer or the energy ray curable pressure sensitive adhesive layer. The layer cannot be irradiated with energy rays. On the other hand, according to this configuration, the energy ray-curable pressure-sensitive adhesive layer can be irradiated with energy rays through the transparent substrate even before the one substrate is peeled off. And an energy ray hardening-type adhesive layer and a board | substrate can be peeled first, and a temperature-sensitive adhesive layer and a board | substrate can be peeled after that.

In the temporary fixing method according to one aspect of the present invention, after the two substrates are temporarily fixed, at least one of the temporarily fixed substrates may be subjected to processing including heat treatment.
Thus, when heat-processing to the board | substrate after temporarily fixing, the peeling force of an adhesive sheet becomes high and it exists in the tendency for a load to be easily applied to a board | substrate. However, according to the temporary fixing method according to an aspect of the present invention, the energy beam curable pressure-sensitive adhesive layer or the energy beam curable pressure-sensitive adhesive layer or the energy beam curable pressure-sensitive adhesive layer or The peeling force of the temperature-sensitive pressure-sensitive adhesive layer can be reduced. Therefore, even when heat treatment is performed on the temporarily fixed substrate, the substrate can be easily peeled from the energy ray-curable pressure-sensitive adhesive layer and the temperature-sensitive pressure-sensitive adhesive layer.

The pressure-sensitive adhesive sheet according to one aspect of the present invention is a pressure-sensitive adhesive sheet used for the temporary fixing method, and includes the energy ray-curable pressure-sensitive adhesive layer and the temperature-sensitive pressure-sensitive adhesive layer. It is.
If the pressure-sensitive adhesive sheet having this configuration is used, two different layers, that is, an energy ray-curable pressure-sensitive adhesive layer and a temperature-sensitive pressure-sensitive adhesive layer, can be provided in one step.

In the adhesive sheet which concerns on 1 aspect of this invention, it is preferable to further provide the peeling film provided in the outer side of the said energy-beam curable adhesive layer and the said thermosensitive adhesive layer.
According to this configuration, the energy ray-curable pressure-sensitive adhesive layer and the temperature-sensitive pressure-sensitive adhesive layer are covered with the release film, so that the handleability as the pressure-sensitive adhesive sheet is excellent and the surface of these pressure-sensitive adhesive layers before use. Contamination can be suppressed.

In the pressure-sensitive adhesive sheet according to one aspect of the present invention, it is preferable that a core material does not exist between the energy ray-curable pressure-sensitive adhesive layer and the temperature-sensitive pressure-sensitive adhesive layer.
In the pressure-sensitive adhesive sheet according to one embodiment of the present invention, the energy ray-curable pressure-sensitive adhesive layer is a thin film that can carry the temperature-sensitive pressure-sensitive adhesive layer. Therefore, even when there is no core material, the energy ray curable pressure-sensitive adhesive layer and the temperature-sensitive pressure-sensitive adhesive layer can be easily peeled from the substrate. Furthermore, there is no change in the shape of the core material caused by a temperature change due to heat treatment or the like, and the load on the substrate due to this can be suppressed.

It is a schematic sectional drawing which shows the adhesive sheet which concerns on 1st embodiment of this invention. It is explanatory drawing which shows the method of peeling each of the two board | substrates temporarily fixed by this temporary fixing method and the temporary fixing method which concerns on 1st embodiment of this invention. It is explanatory drawing which shows the temporary fixing method which concerns on 2nd embodiment of this invention.

[First embodiment]
Hereinafter, the present invention will be described with reference to embodiments. The present invention is not limited to the contents of the embodiment.
In the first embodiment, a temporary fixing method in which a flexible substrate is temporarily fixed to a rigid substrate using an adhesive sheet will be described as an example with reference to the drawings. First, the pressure-sensitive adhesive sheet according to this embodiment will be described.

(Adhesive sheet)
As shown in FIG. 1, the pressure-sensitive adhesive sheet 1 according to this embodiment includes a temperature-sensitive pressure-sensitive adhesive layer 11, an energy ray-curable pressure-sensitive adhesive layer 12, and release films 13 and 14 provided on the outside thereof, It has.

The temperature-sensitive pressure-sensitive adhesive layer 11 is a layer whose peeling force changes due to a temperature change. For example, when the temperature is set to a predetermined temperature or lower, the peeling force is reduced.
The temperature-sensitive pressure-sensitive adhesive layer 11 is preferably a layer containing a side chain crystalline polymer and having a peel strength that is reduced at a temperature equal to or lower than the melting point of the side chain crystalline polymer.
The side chain crystalline polymer is a polymer that reversibly causes a crystalline state and a fluid state in response to a temperature change. The temperature-sensitive adhesive layer 11 contains this side chain crystalline polymer as a main component.
Melting point shall mean the temperature at which a particular portion of the polymer that was initially aligned in an ordered arrangement is disordered by some equilibrium process. The melting point is a value obtained by measurement with a differential thermal scanning calorimeter (DSC) under measurement conditions of 10 ° C./min.
The range of the melting point of the temperature-sensitive adhesive layer 11 is preferably room temperature (for example, 25 ° C.) or less, more preferably 0 ° C. or more and 15 ° C. or less. If the melting point is too high, unintended peeling may occur during temporary fixing. Also, if the melting point is too low, special measures may be required to prevent defects due to condensation or frost adhesion.

  The side chain crystalline polymer is composed of a polymer obtained by polymerizing a monomer constituting the side chain crystalline polymer (hereinafter sometimes referred to as “monomer”). Examples of the monomer include (meth) acrylate having a linear alkyl group having 16 or more carbon atoms, (meth) acrylate having an alkyl group having 1 to 6 carbon atoms, and a polar monomer. These may be used alone or in combination of two or more.

Examples of the (meth) acrylate having a linear alkyl group having 16 or more carbon atoms include 16 to 22 carbon atoms such as cetyl (meth) acrylate, stearyl (meth) acrylate, eicosyl (meth) acrylate, and behenyl (meth) acrylate. (Meth) acrylates having a linear alkyl group of
Examples of the (meth) acrylate having an alkyl group having 1 to 6 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, and the like.
Examples of polar monomers include ethylenically unsaturated monomers having a carboxyl group such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meta And ethylenically unsaturated monomers having a hydroxyl group such as acrylate and 2-hydroxyhexyl (meth) acrylate.

  As a polymerization ratio of the monomer, 30 to 100 parts by mass of a (meth) acrylate having a linear alkyl group having 16 or more carbon atoms, and 0 to 70 parts by mass of a (meth) acrylate having an alkyl group having 1 to 6 carbon atoms. The polar monomer is preferably 0 to 10 parts by mass. The monomer species and the polymerization ratio are preferably selected so that the melting point of the side chain crystalline polymer obtained by polymerization is the predetermined temperature.

  The polymerization method is not particularly limited, and examples thereof include a solution polymerization method, a bulk polymerization method, a suspension polymerization method, and an emulsion polymerization method. For example, when the solution polymerization method is employed, the above-described monomers may be added to the solvent and mixed, and stirred at about 40 to 90 ° C. for about 2 to 10 hours.

  The mass average molecular weight of the polymer constituting the side chain crystalline polymer is preferably 200,000 or more and 1,000,000 or less, and more preferably 400,000 or more and 700,000 or less. The mass average molecular weight is a value obtained by measuring a polymer by gel permeation chromatography (GPC) and converting the obtained measurement value into polystyrene.

  On the other hand, as a material constituting the temperature-sensitive adhesive layer 11 together with such a side chain crystalline polymer, for example, polyethylene, polyethylene terephthalate, polypropylene, polyester, polyamide, polyimide, polycarbonate, ethylene vinyl acetate copolymer, ethylene ethyl Examples thereof include synthetic resins such as acrylate copolymers, ethylene polypropylene copolymers, and polyvinyl chloride.

  The thickness of the temperature-sensitive adhesive layer 11 is not particularly limited, but is usually 2 μm or more and 200 μm or less. If the thickness is less than the lower limit, there is a possibility that the peeling force for temporary fixing cannot be obtained sufficiently. On the other hand, if the thickness exceeds the upper limit, the pressure-sensitive adhesive layer tends to be deformed by heat treatment.

The energy ray-curable pressure-sensitive adhesive layer 12 is a layer that is cured by energy rays and has a peeling force that decreases.
The energy ray-curable pressure-sensitive adhesive layer 12 is preferably a layer made of an energy-ray-curable pressure-sensitive adhesive that has a large initial peel force and a large drop in peel strength after irradiation with energy rays.

  As the energy ray curable (ultraviolet ray curable, electron beam curable) pressure-sensitive adhesive, it is particularly preferable to use an ultraviolet curable pressure-sensitive adhesive. The energy ray curable pressure sensitive adhesive generally comprises an acrylic pressure sensitive adhesive and an energy ray polymerizable compound as main components. Examples of the energy ray polymerizable compound used in the energy ray curable pressure-sensitive adhesive include a low molecular weight compound having at least two photopolymerizable carbon-carbon double bonds in a molecule that can be three-dimensionally reticulated by light irradiation. Used.

  The acrylic adhesive has an acrylic copolymer as a main component. Examples of the acrylic copolymer include a polymer obtained by polymerizing an alkyl ester of (meth) acrylic acid as a main component and a polar monomer (functional group-containing monomer) that can be copolymerized therewith. .

  As the alkyl ester of (meth) acrylic acid, an alkyl ester of (meth) acrylic acid having 1 to 12 carbon atoms in the alkyl group is preferably used. Specifically, methyl acrylate, methyl methacrylate, acrylic Ethyl acetate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, pentyl acrylate, pentyl methacrylate, hexyl acrylate, hexyl methacrylate Octyl acrylate, octyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl acrylate, lauryl methacrylate, and the like. Examples of polar monomers (functional group-containing monomers) include acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, and 2-hydroxyethyl methacrylate. An acrylic copolymer may be used individually by 1 type, or 2 or more types may be mixed and used for it.

  The molecular weight of the acrylic copolymer is preferably 100,000 or more, and more preferably 150,000 to 2,000,000. Moreover, the glass transition temperature of an acrylic copolymer is 20 degrees C or less normally, Preferably it is -70 degreeC or more and 10 degrees C or less.

  Specific examples of the low molecular weight compound having at least two photopolymerizable carbon-carbon double bonds in the molecule include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol monohydroxy. Pentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and the like can be used.

  Furthermore, in addition to the acrylate compounds as described above, urethane acrylate oligomers can also be used as the energy beam polymerizable compound. The urethane acrylate oligomer includes a polyol compound such as a polyester type or a polyether type and a polyvalent isocyanate compound (for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1 , 4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc., and a terminal isocyanate urethane prepolymer obtained by reacting with an acrylate or methacrylate having a hydroxyl group (for example, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, polyethylene glycol acrylate, polyethylene glycol methacrylate, etc. Obtained by reacting.

  The energy ray curable pressure-sensitive adhesive layer 12 may be formed of an energy ray curable copolymer having an energy ray polymerizable group in a side chain (hereinafter sometimes referred to as “adduct polymer”). Such an energy beam curable copolymer has the property of having both adhesiveness and energy beam curable properties. As the energy ray curable copolymer having an energy ray polymerizable group in the side chain, known ones can be appropriately used.

  The energy ray curable copolymer is obtained by reacting an acrylic copolymer having a functional group-containing monomer in the side chain with a compound having an energy ray polymerizable group and a substituent that reacts with the functional group. It is done. Examples of such an acrylic copolymer include a copolymer of an alkyl ester of (meth) acrylic acid exemplified in the above-mentioned acrylic copolymer and a functional group monomer. Examples of the compound having a substituent and an energy beam polymerizable group include methacryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, glycidyl (meth). Examples include acrylate and (meth) acrylic acid.

  The molecular weight of the energy beam curable copolymer is preferably 100,000 or more, and more preferably 150,000 to 2,000,000. Moreover, the glass transition temperature of an acrylic copolymer is 20 degrees C or less normally, Preferably it is -70 degreeC or more and 10 degrees C or less.

It is preferable that a photopolymerization initiator is further added to the energy ray-curable pressure-sensitive adhesive and the acrylic pressure-sensitive adhesive and the energy ray-polymerizable compound or the energy ray-curable copolymer. By using a photopolymerization initiator in the energy ray curable pressure-sensitive adhesive layer, sufficient curability can be obtained even when ultraviolet rays (UV) are used as the energy rays to be irradiated, and the peelability from the substrate is improved. .
Specific examples of the photopolymerization initiator include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, benzoin dimethyl ketal, and 2,4. -Diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, 2-chloroanthraquinone or 2,4,6-trimethylbenzoyl Diphenylphosphine oxide, 2-benzothiazole-N, N-diethyldithiocarbamate, oligo {2-hydroxy-2-methyl-1- [4- (1-propenyl) phenyl] propanone} and the like. A photoinitiator may be used individually or may be used in mixture of 2 or more types.

  Moreover, other components may be mix | blended with the energy-beam curable adhesive in the range which does not impair the objective of this invention. Examples of other components include a crosslinking agent, a curing agent, an inorganic filler, an organic filler, a plasticizer, an antistatic agent, an antioxidant, a pigment, and a dye. These may be used alone or in combination of two or more.

  The thickness of the energy ray curable pressure-sensitive adhesive layer 12 is not particularly limited, but is usually 2 μm or more and 200 μm or less. If the thickness is less than the lower limit, there is a possibility that the peeling force for temporary fixing cannot be obtained sufficiently. On the other hand, if the thickness exceeds the upper limit, the pressure-sensitive adhesive layer tends to be deformed by heat treatment.

The release films 13 and 14 are laminated on each adhesive surface for protection of the adhesive surface during storage or transportation, or as a carrier during application. The release films 13 and 14 are formed by applying a release agent such as a silicone resin to a dimensionally stable plastic film such as a polyethylene terephthalate film to form a layer.
In order to smoothly perform the sticking operation of the pressure-sensitive adhesive sheet 1, the peeling force between the release film 13 laminated on the surface of the temperature-sensitive pressure-sensitive adhesive layer 11 and the release film 14 laminated on the surface of the energy ray-curable pressure-sensitive adhesive layer 12 It is preferable to provide a difference in. A release film with a small peel strength (light release) is laminated on the adhesive surface on the side of the substrate to be applied first, and a release film with a large release force (heavy release) on the adhesive surface on the side to be applied later. Have a laminated structure. With such a configuration, the operation of attaching the adhesive sheet 1 to the two substrates 2 and 3 can be performed smoothly. The release film 13 laminated on the surface of the temperature-sensitive adhesive layer 11 may be a light release release film, and the release film 14 laminated on the energy ray curable adhesive layer 12 may be a heavy release release film. Or the opposite combination. The correspondence between the release film and the pressure-sensitive adhesive layer may be appropriately selected according to the function of the sticking device or the like so that the work process becomes smooth.
As the release film, a single film having a release agent layer formed on both sides of a plastic film is used, and a temperature-sensitive adhesive layer 11 and an energy ray-curable adhesive layer 12 are laminated on one side to form a roll. It is good also as a form by which both surfaces of an adhesion surface are protected by winding up.

Such a pressure-sensitive adhesive sheet 1 can be produced, for example, by forming a sheet made of a temperature-sensitive pressure-sensitive adhesive layer 11 and a sheet made of an energy ray-curable pressure-sensitive adhesive layer 12 and bonding one side of each. preferable.
First, for the temperature-sensitive adhesive or the energy ray-curable adhesive, a coating agent having an appropriate viscosity is prepared by dissolving the components forming each in a solvent. Next, a coating agent for forming a temperature-sensitive adhesive is applied to the release surface of the release film 13 and dried to form the temperature-sensitive adhesive layer 11. On the other hand, the energy ray curable pressure-sensitive adhesive layer 12 is formed by applying a coating agent for forming the energy ray curable pressure sensitive adhesive to the release surface of the release film 14 and drying it. Examples of the coating treatment means include a knife coater, a roll coater, a roll knife coater, a die coater, a curtain coater, a gravure coater, and a rod coater. Subsequently, the exposed surface of the temperature-sensitive pressure-sensitive adhesive layer 11 and the exposed surface of the energy ray-curable pressure-sensitive adhesive layer 12 are opposed to each other and bonded together. Thereby, the adhesive sheet 1 which becomes the order of the peeling film 13, the temperature sensitive adhesive layer 11, the energy-beam curable adhesive layer 12, and the peeling film 14 is obtained.

  In the above manufacturing method, a manufacturing method in which the temperature-sensitive adhesive layer 11 or the energy ray-curable adhesive layer 12 is directly bonded after coating and drying is shown. In place of this manufacturing method, either one or both of the temperature-sensitive adhesive layer 11 and the energy ray-curable adhesive layer 12 are applied and dried, and then another release film is attached to the exposed surface of the adhesive layer. In addition, after storing for a predetermined period, a manufacturing method may be employed in which the other release film is peeled off and bonded to the other pressure-sensitive adhesive layer. In this case, the release film to which the coating agent is applied may be replaced with another release film, and the release film bonded to the exposed adhesive surface may be used as the release film 13 or the release film 14. Also, one adhesive layer uses another release film that has been stored for a predetermined period of time, and the other adhesive film is peeled off on the adhesive layer surface immediately after the other adhesive layer is applied and dried. However, the manufacturing method of bonding together may be adopted.

  Further, the pressure-sensitive adhesive sheet 1 may be a method in which the temperature-sensitive pressure-sensitive adhesive layer 11 and the energy ray-curable pressure-sensitive adhesive layer 12 are not separately formed, and the film is formed in a batch as a sheet in which two layers are laminated. . As a method of forming two layers at once, a die coater or a curtain coater having a coating head in which a plurality of discharge ports are incorporated, and each coating agent is applied to the release film 13 or the release film 14 from another discharge port. Apply to the release surface and dry together. A production method for obtaining the pressure-sensitive adhesive sheet 1 by laminating the other release film on the exposed surface of the laminated body of the obtained temperature-sensitive pressure-sensitive adhesive layer 11 and the energy ray-curable pressure-sensitive adhesive layer 12 can be mentioned.

About the peeling force of the temperature sensitive adhesive layer 11, it is preferable to satisfy | fill all the conditions (A1), (A2), and (A3) shown below. In such a case, the temperature-sensitive pressure-sensitive adhesive layer 11 has a sufficient peeling force at room temperature. For example, when the temperature is set to a predetermined temperature or lower (for example, 10 ° C. or lower), the peeling force of the temperature-sensitive pressure-sensitive adhesive layer 11 is reduced, so that the substrate can be easily peeled from the temperature-sensitive pressure-sensitive adhesive layer 11. The substrate is an object to which the temperature-sensitive adhesive layer 11 adheres, and the material thereof is glass, silicon, plastic, or the like.
Condition (A1): The peeling force with respect to the substrate at a temperature of 23 ° C. is 700 mN / 25 mm or more (more preferably 1000 mN / 25 mm or more and 10,000 mN / 25 mm or less).
Condition (A2): When the heat-sensitive adhesive layer 11 is subjected to heat treatment (for example, 150 ° C. for 1 hour), the peel force to the substrate at a temperature of 23 ° C. is 700 mN / 25 mm or more (more preferably 1000 mN / 25 mm). More than 20000 mN / 25 mm.
Condition (A3): When the heat-sensitive adhesive layer 11 is subjected to heat treatment (for example, 150 ° C. for 1 hour), the peel force to the substrate at a temperature of 5 ° C. is 500 mN / 25 mm or less (more preferably 10 mN / 25 mm). More than 300mN / 25mm.
In addition, peeling force (180 degree peeling strength) can be measured by the method based on description to JISZ0237.

About the peeling force of the energy ray hardening-type adhesive layer 12, it is preferable to satisfy | fill all of conditions (B1)-(B3) among conditions (B1)-(B4) shown below, and conditions (B1)-( It is particularly preferable to satisfy all of B4). In such a case, the energy ray curable pressure-sensitive adhesive layer 12 has a sufficient peeling force before irradiation with energy rays. If the energy beam curable pressure-sensitive adhesive layer 12 is irradiated with energy rays, the peeling force of the energy beam curable pressure-sensitive adhesive layer 12 decreases, so that the substrate can be easily removed from the energy beam curable pressure-sensitive adhesive layer. Can be peeled off. The substrate is an object to which the energy ray curable pressure-sensitive adhesive layer 12 adheres, and the material thereof is glass, silicon, plastic, or the like.
Condition (B1): The peeling force with respect to the substrate at a temperature of 23 ° C. is 800 mN / 25 mm or more (more preferably 1000 mN / 25 mm or more and 10000 mN / 25 mm or less).
Condition (B2): When heat treatment (for example, 150 ° C. for 1 hour) is performed on the energy ray curable pressure-sensitive adhesive layer 12, the peel force with respect to the substrate at a temperature of 23 ° C. is 800 mN / 25 mm or more (more preferably 1000 mN / 25 mm or more and 20000 mN / 25 mm or less).
Condition (B3): When the heat treatment (for example, 150 ° C. for 1 hour) is performed on the energy ray curable pressure-sensitive adhesive layer 12, the peeling force with respect to the substrate at a temperature of 5 ° C. is 800 mN / 25 mm or more (preferably 1000 mN / 25 mm). 10000 mN / 25 mm or less).
Condition (B4): The energy ray curable pressure-sensitive adhesive layer 12 is heat-treated (for example, 150 ° C. for 1 hour), left at a temperature of 5 ° C. for 20 minutes, and then further irradiated with energy rays (for example, ultraviolet light having a light amount of 200 mJ / cm ² ). In the case of irradiation, the peeling force on the substrate at a temperature of 23 ° C. is 700 mN / 25 mm or less (more preferably 10 mN / 25 mm or more and 600 mN / 25 mm or less).

(Temporary fixing method)
Next, the temporary fixing method according to the present embodiment will be described.
FIG. 2 is an explanatory diagram showing a temporary fixing method according to the first embodiment and a method of peeling two substrates temporarily fixed by the temporary fixing method.
In the temporary fixing method according to the present embodiment, as shown in FIG. 2 (B), between the flexible substrate 2 and the rigid substrate 3, an energy ray-curable pressure-sensitive adhesive layer 12, a temperature-sensitive pressure-sensitive adhesive layer 11, and , And the flexible substrate 2 and the rigid substrate 3 are temporarily fixed (temporary fixing step).
Moreover, in this embodiment, the peeling film 13 laminated | stacked on the temperature-sensitive adhesive layer 11 is a peeling film which shows light peeling, and the peeling film 14 laminated | stacked on the energy-beam curable adhesive layer 12 is heavy peeling. The adhesive sheet 1 which is a peeling film which shows is used.
In the temporary fixing step, the release film 13 is peeled from the pressure-sensitive adhesive sheet 1, and the temperature-sensitive pressure-sensitive adhesive layer 11 is exposed and attached to the flexible substrate 2. Subsequently, the release film 14 is peeled to expose the energy ray curable pressure-sensitive adhesive sheet so as to be opposed to the rigid substrate 3, and both are bonded together to temporarily fix the flexible substrate 2 and the rigid substrate 3 (FIG. 2A). And (B)).

The material of the flexible substrate 2 and the rigid substrate 3 is not particularly limited, and examples thereof include glass, silicon, and plastic. Examples of the plastic include polyethylene terephthalate (PET), polyethylene naphthate (PEN), and polycarbonate (PC). These may be substrates that have been appropriately surface-coated for the production of various products described below.
In the present embodiment, the flexible substrate 2 and the rigid substrate 3 are both transparent substrates that transmit energy rays. The material of the flexible substrate 2 is plastic, and the material of the rigid substrate 3 is glass.

The flexible substrate 2 and the rigid substrate 3 temporarily fixed by the temporary fixing method according to the present embodiment are processed according to the manufacturing process of various products (processing process).
Here, various products include, but are not limited to, an organic thin film transistor (organic TFT), a light emitting element (LED), a flat panel display (FPD), and the like. For example, as a processing step in manufacturing an organic TFT, functional films such as a source / drain electrode, a semiconductor layer, an insulating layer, and a gate electrode are formed on the flexible substrate 2 by a wet method (printing method, spin coating method, For example, a dispenser method, a spray method, and the like.
In such a processing step, heat treatment may be performed for the purpose of sintering the functional film as described above or controlling the orientation. As the heat treatment, for example, heat treatment at 100 ° C. or higher and 220 ° C. or lower for 1 minute or longer and 120 minutes or shorter can be employed.

Next, as shown in FIG. 2C, the flexible substrate 2 is peeled from the flexible substrate 2 and the rigid substrate 3 after the processing step (first peeling step).
In the first peeling step, first, the temperature of the flexible substrate 2 and the rigid substrate 3 after the processing step is set to a predetermined temperature or lower (for example, 10 ° C. or lower), and then the flexible substrate 2 is peeled at the temperature. By doing so, the peeling force of the temperature-sensitive pressure-sensitive adhesive layer 11 is reduced, so that the flexible substrate 2 can be easily peeled from the temperature-sensitive pressure-sensitive adhesive layer 11.
As shown in FIG. 2D, the temperature-sensitive adhesive layer 11 and the energy ray-curable adhesive layer 12 remain on the rigid substrate 3 after the first peeling step, as shown in FIG.

Next, an energy ray is irradiated with respect to the energy ray hardening-type adhesive layer 12 on the rigid board | substrate 3 after a 1st peeling process (energy ray irradiation process). In addition, although this energy ray irradiation process may be performed before a 1st peeling process, in such a case, about the peeling force of the temperature-sensitive adhesive layer 11 and the energy-beam curable adhesive layer 12, it is below. It is preferable to satisfy the condition (C1) shown. When the condition (C1) shown below is satisfied, the flexible substrate 2 and the temperature-sensitive adhesive layer 11 can be easily peeled off.
Condition (C1): In the temperature-sensitive pressure-sensitive adhesive layer 11 side of the pressure-sensitive adhesive sheet 1 and the flexible substrate 2, the peeling force in the condition (A3) is on the energy-beam curable pressure-sensitive adhesive layer 12 side of the pressure-sensitive adhesive sheet 1 and the rigid substrate 3. , Smaller than the peeling force in the condition (B3).
In the energy ray curable pressure-sensitive adhesive layer 12, the peeling force is greatly reduced by irradiation with energy rays. As energy rays, ultraviolet rays, electron beams, and the like are used. Further, the amount of irradiation varies depending on the type of energy beam, and is not particularly limited. When used, for example ultraviolet radiation is typically illuminance is at 1 mW / cm ² or more 1000 mW / cm ² or less, the amount of light 40 mJ / cm ² or more 1000 mJ / cm ² or less.

Next, as shown in FIG. 2E, the temperature-sensitive pressure-sensitive adhesive layer 11 and the energy-beam curable pressure-sensitive adhesive layer 12 are peeled off from the rigid substrate 3 after the energy ray irradiation step (second peeling step).
In the second peeling step, the peeling force of the energy ray curable pressure-sensitive adhesive layer 12 is reduced by the energy ray irradiation step, so that the energy ray curable pressure-sensitive adhesive layer 12 can be easily peeled from the rigid substrate 3. The energy ray curable pressure-sensitive adhesive layer 12 is a thin film that can carry the temperature-sensitive pressure-sensitive adhesive layer 11. Then, by peeling the thin film from the rigid substrate 3, the supported temperature-sensitive adhesive layer 11 can be peeled from the rigid substrate 3 together.

(Operational effects of the first embodiment)
According to this embodiment, the following operational effects can be achieved.
(1) After the flexible substrate 2 and the rigid substrate 3 are temporarily fixed and processed, if the temperature is set to a predetermined temperature or less, the peeling force of the temperature-sensitive adhesive layer 11 is reduced. Can be peeled off.
(2) Since the energy beam curable pressure-sensitive adhesive layer 12 is reduced in peeling force by the energy beam irradiation step, and the energy beam curable pressure-sensitive adhesive layer 12 is a thin film that can be carried by the temperature-sensitive pressure-sensitive adhesive layer 11, The temperature-sensitive adhesive layer 11 and the energy ray curable adhesive layer 12 are peeled together from the rigid substrate 3, and the adhesive can be easily removed from the rigid substrate 3. Therefore, the rigid substrate 3 used as the support substrate can be reused.
(3) By temporarily fixing the flexible substrate 2 to the rigid substrate 3, it is possible to easily process and transport various products in the manufacturing process.
(4) In the pressure-sensitive adhesive sheet 1, the energy ray-curable pressure-sensitive adhesive layer 12 and the temperature-sensitive pressure-sensitive adhesive layer 11 are covered with the release film 13, so that surface contamination of these pressure-sensitive adhesive layers before use can be suppressed.
(5) Since the core material is not provided in the pressure-sensitive adhesive sheet 1, the structure of the pressure-sensitive adhesive sheet is simplified, and there is no change in the shape of the core material due to a temperature change caused by heat treatment or the like, thereby suppressing the load on the substrate. it can.

[Second Embodiment]
Next, a second embodiment of the present invention will be described based on the drawings.
The first pressure-sensitive adhesive sheet 4 and the second pressure-sensitive adhesive sheet 5 of the present embodiment are substantially the same as the temperature-sensitive pressure-sensitive adhesive layer 11 and the energy ray-curable pressure-sensitive adhesive layer 12 in the first embodiment, respectively. Therefore, the detailed description is omitted or simplified.
FIG. 3 is an explanatory view showing a temporary fixing method according to the second embodiment.
In the first embodiment, the pressure-sensitive adhesive sheet 1 in which the temperature-sensitive pressure-sensitive adhesive layer 11 and the energy ray-curable pressure-sensitive adhesive layer 12 are laminated is used. On the other hand, in the second embodiment, the first pressure-sensitive adhesive sheet 4 composed of the temperature-sensitive pressure-sensitive adhesive layer 11 and the light release film 15 and the heavy release film 16 laminated on both surfaces thereof, and the energy ray curable pressure-sensitive adhesive. A second pressure-sensitive adhesive sheet 5 composed of the agent layer 12 and the light release film 17 and the heavy release film 18 laminated on both sides thereof is used.

  In the temporary fixing method according to the present embodiment, the temperature-sensitive adhesive layer 11 and the flexible substrate 2 that are exposed by peeling off the light release film 15 of the first pressure-sensitive adhesive sheet 4 are bonded together, and on the other hand, the second The light release film 17 of the pressure-sensitive adhesive sheet 5 is peeled off and the energy ray-curable pressure-sensitive adhesive layer 12 exposed and the rigid substrate 3 are bonded together. Further, the heavy release film 16 on the temperature-sensitive pressure-sensitive adhesive layer 11 and the heavy release film 18 on the energy ray-curable pressure-sensitive adhesive layer 12 are peeled off, and the exposed temperature-sensitive pressure-sensitive adhesive layer 11 and the energy-ray-curable type are exposed. The adhesive layer 12 is bonded, and the flexible substrate 2 and the rigid substrate 3 are temporarily fixed (see FIGS. 3A and 3B).

In the temporary fixing method according to the present embodiment, next, the flexible substrate 2 and the rigid substrate 3 after the temporary fixing step are processed according to the manufacturing process of various products (processing step).
Next, the flexible substrate 2 is peeled from the flexible substrate 2 and the rigid substrate 3 by cooling to a predetermined temperature (first peeling step). Then, by irradiating the rigid substrate 3 on which the temperature-sensitive adhesive layer 11 and the energy ray-curable adhesive layer 12 remain, energy rays are irradiated from the rigid substrate 3 to the temperature-sensitive adhesive layer 11 and the energy beam. The curable pressure-sensitive adhesive layer 12 is peeled together (second peeling step).
According to this embodiment, the same operational effects as those of the first embodiment can be obtained.

[Modification of Embodiment]
The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above-described embodiment, the temporary fixing method in which the temperature-sensitive adhesive layer 11 is laminated on the flexible substrate 2 and the energy ray curable adhesive layer 12 is laminated on the rigid substrate 3 is shown. On the other hand, a temporary fixing method in which the flexible substrate 2 and the energy ray curable pressure-sensitive adhesive layer 12, the rigid substrate 3 and the temperature-sensitive pressure-sensitive adhesive layer 11 are laminated may be used.

  In the above-described embodiment, the temperature-sensitive pressure-sensitive adhesive layer 11 is first peeled off from the substrate by cooling to a predetermined temperature, and the energy-ray-curable pressure-sensitive adhesive layer 12 is cured by energy ray irradiation. A temporary fixing method is shown in which an operation of peeling the interface between the energy ray curable pressure-sensitive adhesive layer 12 and the substrate is performed later. On the other hand, the energy ray-curable pressure-sensitive adhesive layer by energy ray irradiation is cured, the interface between the energy ray-curable pressure-sensitive adhesive layer 12 and the substrate is first peeled, and cooled to a predetermined temperature, thereby being a temperature-sensitive pressure-sensitive adhesive. The peeling operation at the interface between the layer 11 and the substrate may be performed later. In addition, the energy ray curable pressure-sensitive adhesive layer 12 is not peeled off while the energy ray curable pressure-sensitive adhesive layer 12 is cured by energy ray irradiation, and is cooled to a predetermined temperature, whereby the interface between the temperature-sensitive pressure-sensitive adhesive layer 11 and the substrate. Then, the interface between the energy ray curable pressure-sensitive adhesive layer 12 and the substrate may be peeled off. In this case, the energy beam irradiation may be performed not before the peeling operation but before a processing step or heat treatment for various products.

  Further, in the above-described embodiment, the core material is not used for the pressure-sensitive adhesive sheet 1, but the pressure-sensitive adhesive sheet in which the core material is laminated between the temperature-sensitive pressure-sensitive adhesive layer 11 and the energy ray-curable pressure-sensitive adhesive layer 12 is provided. May be used. If the core material has a necessary and sufficient resistance to the processing conditions adopted according to the manufacturing process of various products, the load on each substrate can be suppressed. In this case, since the tensile strength of the pressure-sensitive adhesive sheet is increased, the pressure-sensitive adhesive layer is hardly broken by the peeling operation.

In the above-described embodiment, the flexible substrate 2 and the rigid substrate 3 are temporarily fixed, but the present invention is not limited to this. That is, in the above-described embodiment, the flexible substrate 2 is temporarily fixed to the rigid substrate 3 from the viewpoint of ease of processing and transport in the manufacturing process of various products, but the purpose of temporary fixing is not limited. Regardless of the purpose of temporary fixing, various substrates can be temporarily fixed.
In the above-described embodiment, transparent substrates are used as the flexible substrate 2 and the rigid substrate 3, but the present invention is not limited to this. For example, both the flexible substrate 2 and the rigid substrate 3 may be opaque substrates. However, in such a case, the energy beam curable pressure-sensitive adhesive layer 12 must be removed after one substrate is peeled off to expose the temperature-sensitive pressure-sensitive adhesive layer 11 or the energy beam curable pressure-sensitive adhesive layer 12. Cannot be irradiated with energy rays.

EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these examples.
[Example 1]
Adduct in which methacryloyloxyethyl isocyanate 22.4 parts by mass is reacted with 100 parts by mass of a copolymer consisting of butyl acrylate, methyl methacrylate and hydroxy acrylate (mass ratio: 62/10/28), and a methacryloyl group is introduced into the side chain A polymer (Mw: 600,000) was obtained. 30 parts by weight of the solid content of this adduct polymer, 1 part by weight of an isocyanate crosslinking agent (trade name: BHS-8515, manufactured by Toyochem Co.) and 3 parts by weight of a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) The mixture was diluted and mixed using ethyl acetate as a diluent solvent to prepare a coating solution for an adhesive having a concentration of 26% by mass.
This pressure-sensitive adhesive coating solution is applied to the release surface of a release film (trade name: SP-PE3811 (S), manufactured by Lintec Corporation) using a knife coater, dried by heating, and then an energy ray curable pressure-sensitive adhesive layer (ultraviolet curable type). ) Was formed. The film thickness of the obtained energy ray-curable pressure-sensitive adhesive layer was 25 μm.
On the other hand, a single-sided release film is peeled off from a temperature-sensitive adhesive sheet (made by Nitta, trade name: Intellimer tape, cool-off type, melting point 7 ° C.) to expose the adhesive surface, and the adhesive surface is obtained as described above. The surface of the energy beam curable pressure-sensitive adhesive layer was laminated with a laminator to obtain a pressure-sensitive adhesive sheet comprising a temperature-sensitive pressure-sensitive adhesive layer and an energy beam curable pressure-sensitive adhesive layer.

[Example 2]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the coating solution for the energy ray-curable pressure-sensitive adhesive layer in Example 1 was changed to the following composition.
Adduct polymer (Mw: 600,000) in which 12 parts by mass of methacryloyloxyethyl isocyanate was reacted with 100 parts by mass of a copolymer of butyl acrylate and hydroxyethyl acrylate (mass ratio: 85/15) ) 35 parts by mass of the solid content of this adduct polymer, 1 part by mass of an isocyanate crosslinking agent (manufactured by Toyochem, trade name: BHS-8515) and 4 parts by mass of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals, trade name: Irgacure 184) Dilution mixing was performed using ethyl acetate as a dilution solvent, and a coating solution for pressure-sensitive adhesive having a concentration of 30% by mass was prepared.

[Comparative Example 1]
A temperature-sensitive pressure-sensitive adhesive sheet (manufactured by Nitta Co., Ltd., trade name: Intellimer tape, cool-off type, melting point 7 ° C.) was used as a pressure-sensitive adhesive sheet having a single temperature-sensitive pressure-sensitive adhesive layer.
[Comparative Example 2]
A release film (trade name: SP-PET50C, manufactured by Lintec Corporation) is laminated on the exposed surface of the energy beam curable pressure-sensitive adhesive layer prepared in Example 1, and the energy beam curable pressure-sensitive adhesive layer is a single layer adhesive. It was set as a sheet.
[Comparative Example 3]
A release film (trade name: SP-PET50C, manufactured by Lintec Corporation) is laminated on the exposed surface of the energy beam curable pressure-sensitive adhesive layer prepared in Example 2, and the energy beam curable pressure-sensitive adhesive layer is a single layer. It was set as a sheet.

[Peeling force test]
The release film on one side of the pressure-sensitive adhesive sheets of Examples and Comparative Examples (for the examples, the surface on the energy ray curable pressure-sensitive adhesive layer side) was peeled off, and a polyethylene terephthalate (PET) pressure-sensitive adhesive tape ( (PET thickness 25 μm, strong adhesive type) are laminated and cut to a width of 25 mm, and then the release film on the opposite surface (the surface on the temperature-sensitive adhesive layer side in the example) is peeled off to obtain a thick flexible substrate. A 125 μm PEN film (manufactured by Teijin DuPont, trade name: Teonex PQDA5) was attached as an adherend with a 1 kg roll in an environment of 23 ° C. and 50 RH% to obtain a sample for a peel strength test on the PEN film. . Then, after applying any one of the following load conditions 1 to 3 and 5 to each sample, it was deposited at 300 mm / min in a 180 ° direction by a universal tensile tester under any of the following measurement conditions 1 to 3 and 5. It peeled from the body and the peeling force (unit: mN / 25mm) with respect to a PEN film was measured. The obtained results are shown in Table 1.
On the other hand, the release film on the other side of the pressure-sensitive adhesive sheets of Examples and Comparative Examples (the surface on the temperature-sensitive pressure-sensitive adhesive layer side in the examples) is peeled off, and the PET pressure-sensitive adhesive tape (PET thickness) is exposed on the exposed pressure-sensitive adhesive surface. 25 μm, strong adhesive type) are laminated and cut to a width of 25 mm, and then the release film on the opposite side (in the embodiment, the surface on the energy ray curable adhesive layer side) is peeled off to form a glass plate as a rigid substrate (Alkali-free glass, product of Corning, trade name: EagleXG) was used as an adherend, and a 1 kg roll was applied in an environment of 23 ° C. and 50 RH% to obtain a sample for a peel strength test on a glass plate. Thereafter, each sample is subjected to any one of the following load conditions 1 to 4, and then peeled from the adherend at 300 mm / min in the 180 ° direction by a universal tensile tester under any of the following measurement conditions 1 to 4. The peel force (unit: mN / 25 mm) for the glass plate was measured. The obtained results are shown in Table 1.
(Load condition / Measurement condition)
Condition 1: No load / 23 ° C 50RH% (Note 1)
Condition 2: Heat treatment at 150 ° C. for 1 hour / 23 ° C. and 50 RH% (Note 1)
Condition 3: Heat treatment at 150 ° C. for 1 hour / 5 ° C. (Note 2)
Condition 4: Heat treatment at 150 ° C for 1 hour-Cooling treatment at 5 ° C for 20 minutes-Irradiation with ultraviolet light (UV) with a light amount of 200 mJ / cm ² at room temperature / 23 ° C and 50RH%
Condition 5: Heat treatment at 150 ° C. for 1 hour-UV irradiation with a light amount of 200 mJ / cm ² at room temperature / 23 ° C. and 50 RH% (Note 1)
(Note 1) “23 ° C., 50 RH%” was left in a 23 ° C., 50 RH% environment for 20 minutes and then subjected to a peel strength test in the same environment.
(Note 2) “5 ° C.” was left in an environmental test room at 5 ° C. for 20 minutes and then subjected to a peel force test under the same environment.

(Note 3) About the peeling force to the PEN film of Comparative Example 2 and Comparative Example 3, the peeling force under the above condition 5 was measured instead of the above condition 3. In addition, the peeling force (peeling force at 5 ° C. after heat treatment at 150 ° C. for 1 hour) to the PEN films of Comparative Example 2 and Comparative Example 3 is the peeling force (150 ° C. 1 The peel strength at 23 ° C. and 50 RH% after heat treatment for a long time) is almost equivalent. As described above, even if the temperature is set to 5 ° C. after the heat treatment, the peeling force does not decrease, so that the PEN film cannot be easily peeled off. Therefore, Comparative Example 2 and Comparative Example 3 are evaluated under the above-described condition 5 in which UV irradiation is performed after heat treatment to reduce the peeling force.
[Evaluation of peelability]
A sample was prepared by performing the same operation as in the sample preparation in the above peel force test except that the PET adhesive tape was not laminated. When the adherend was a PEN film, the peel force test was performed under the above condition 3, and when the adherend was a glass plate, the peel force test was performed under the above condition 4. In addition, about the peeling force to the PEN film of the comparative example 2 and the comparative example 3, the peeling force test was done on the said conditions 5. FIG. About the sample after this peeling force test, the adhesive remaining state of the adherend and the state of the adhesive sheet were observed. The evaluation criteria for peelability were as follows. The obtained results are shown in Table 2.
A: There is no adhesive residue on the adherend after peeling, and the adhesive sheet has no damage such as breakage.
B: No adhesive residue is observed on the adherend after peeling, but the adhesive sheet is partially broken.
C: The adhesive residue and the adhesive sheet are damaged.

[Total peelability]
In the evaluation of peelability, the evaluation on the PEN surface and the glass surface is A, and the overall peelability evaluation is A when there is no problem in each peeling operation, and the overall peelability in other cases. Evaluation of sex was B.

As is clear from the results shown in Table 2, in Examples 1 and 2, it was confirmed that the peelability of the PEN surface and the glass surface and the peel balance were all good. From this, when both the energy ray-curable pressure-sensitive adhesive layer and the temperature-sensitive pressure-sensitive adhesive layer are provided between the two substrates (Examples 1 and 2), the temperature is set to 5 ° C. after the heat treatment. Thus, the PEN film can be peeled off from the temperature-sensitive pressure-sensitive adhesive layer without any adhesive residue, and further, the adhesive sheet can be peeled off from the glass plate without adhesive residue by UV irradiation. That is, in such a case, it was confirmed that the substrate after temporary fixing was easy to peel and the adhesive after temporary fixing was easy to remove. That is, it was found that when a rigid substrate is used as a temporarily fixed support substrate, it can be reused as a support substrate in the next temporary fixation.
On the other hand, it was found that when only the temperature-sensitive adhesive layer was provided between the two substrates (Comparative Example 1), adhesive residue on the glass plate and the adhesive sheet were damaged. .
In addition, when only the energy ray-curable pressure-sensitive adhesive layer is provided between the two substrates (Comparative Examples 2 and 3), if the peeling is performed after UV irradiation, the adhesive residue is not left on the adherend after peeling. Although not observed, it was found that the adhesive sheet was partially broken.

  DESCRIPTION OF SYMBOLS 1 ... Adhesive sheet, 11 ... Temperature sensitive adhesive layer, 12 ... Energy-beam curable adhesive layer, 13, 14, 15, 16, 17, 18 ... Release film, 2 ... Flexible substrate, 3 ... Rigid substrate.

Claims (6)

Between the two substrates,
An energy ray curable pressure-sensitive adhesive layer that is cured by energy rays and has a reduced peel force;
A temperature-sensitive pressure-sensitive adhesive layer whose peeling force changes due to a temperature change, and
A pressure-sensitive adhesive sheet using the two substrates temporarily fixed way to temporarily fixed,
The energy ray-curable pressure-sensitive adhesive layer, and the temperature-sensitive pressure-sensitive adhesive layer,
There is no core material between the energy ray-curable pressure-sensitive adhesive layer and the temperature-sensitive pressure-sensitive adhesive layer.
A pressure-sensitive adhesive sheet. In the pressure-sensitive adhesive sheet according to claim 1,
The pressure-sensitive adhesive sheet, wherein the temperature-sensitive pressure-sensitive adhesive layer is a layer containing a side chain crystalline polymer and having a peeling force reduced at a temperature equal to or lower than the melting point of the side chain crystalline polymer. In the pressure-sensitive adhesive sheet according to claim 1 or 2,
Adhesive sheet substrate one of said two substrates is a flexible substrate, other substrate, which is a rigid substrate. In the adhesive sheet according to any one of claims 1 to 3,
Wherein at least one of the two substrates, the pressure-sensitive adhesive sheet which is a transparent substrate which transmits the energy ray. In the adhesive sheet according to any one of claims 1 to 4,
The two substrates after temporary fixing, a pressure-sensitive adhesive sheet, characterized in that for machining, including a heat treatment to at least one of the substrate after the temporary fixing. In the pressure-sensitive adhesive sheet according to any one of claims 1 to 5 ,
A pressure-sensitive adhesive sheet, further comprising a release film provided outside the energy ray-curable pressure-sensitive adhesive layer and the temperature-sensitive pressure-sensitive adhesive layer.

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