JP2019173003A - Manufacturing method of laminate containing adhesive sheet - Google Patents

Abstract

An object to be solved by the present invention is to complete a construction in a short time and at a low temperature, to be capable of joining, and not to transmit an active energy ray, and to have two or more members having flexure or irregularities on a member surface. It is an object of the present invention to provide a curable adhesive composition that can be suitably bonded to an adherend. The present invention relates to a method for manufacturing a laminate in which two or more adherends having a surface through which an active energy ray does not pass are laminated via an adhesive sheet. [1] a step of bonding the body to the body by pressure-sensitive bonding, and a step [2] of irradiating the surface of the adhesive layer of the adhesive sheet with an active energy ray to improve the curing rate of the adhesive layer by 0.01% or more. ], A step [3] of bonding the surface of the adhesive layer of the front adhesive sheet to the second adherend by pressure-sensitive bonding, and setting the curing rate of the adhesive layer to 3% or more from the curing rate of the step [2]. This is a method for producing a laminate including a step [4] of curing in this order. [Selection diagram] None

Description

  The present invention relates to a method for producing a laminate using an adhesive sheet that can be used for laminating two or more adherends having a surface through which an active energy ray is not transmitted.

In recent years, liquid crystal display devices have been widely used as display devices for televisions, smartphones, personal assistant devices (PADs), tablet computers, car navigation systems, and the like.
As the liquid crystal display device, in general, a liquid crystal display panel and a planar illumination device (backlight device), a circuit board (substrate), and other electronic components that are arranged on the back surface of the liquid crystal display panel to illuminate the liquid crystal display panel It is known to have a structure in which members such as a chassis to which a battery is mounted and a heat sink that diffuses heat generated from components are laminated.

  In order to laminate the members constituting the liquid crystal display device, for example, in the case where there are bending or unevenness on the surface of the member to be laminated, after applying the adhesive and making the adhesive follow the bending or unevenness, the application surface In order to remove the thickness unevenness, a method of smoothing the surface to which the adhesive has been applied by squeezing the applied adhesive and then laminating the other member is frequently used (see, for example, Patent Document 1). ).

  Further, in the method of joining the members together, for example, in the case where there are deflections or irregularities on the surface of the members to be laminated, after applying an adhesive and causing the adhesive to follow the deflections or irregularities, the thickness unevenness of the coated surface is increased. In order to remove, the applied adhesive is squeezed to smooth the surface to which the adhesive has been applied, and then the other member is laminated (see, for example, Patent Document 2).

  In the current production, it is necessary to use an adhesive having a long curing time in order to secure the construction time necessary for the above-described lamination process. As a result, a process of curing for a long time is required until the adhesive after the above-described laminating process exhibits sufficient bonding strength.

  As a means of accelerating the curing of the adhesive after the laminating step, heat curing of the adhesive at a high temperature was also examined, but there was a possibility that the members constituting the liquid crystal display device were damaged by the heat at the time of curing. . In addition, due to the difference in thermal expansion of each member, there are problems such as deformation of the member due to strain between the members generated when cooling, cracks between the bonding material and the member, and peeling, and the adhesive was used. There was a problem in the joining method.

In addition, if an adhesive having excellent curability at room temperature is used for shortening the curing time, the construction time required for the above-described lamination process cannot be secured, and the curing proceeds before lamination. In some cases, sufficient bonding strength was not exhibited.
In addition, as a means to complete curing at a low temperature in a short time, a joining method by irradiation of light has also been studied, but it cannot be used for a member that cannot transmit active energy rays, and the applicable member is limited and practical application is difficult. there were.
In view of the above background, there is a strong demand for a new joining method that can complete construction in a short time and at a low temperature and that can suitably join even a light-impermeable material.

JP 2010-181432 A JP 2003-136777 A

  The problem to be solved by the present invention is that the construction can be completed and bonded in a short time and at a low temperature, and the active energy ray is not transmitted, and the surface of the member has two or more objects having bending or unevenness. It is an object of the present invention to provide a curable adhesive composition that can be suitably bonded to an adherend.

  As a result of earnest research, the present inventors have found that the above problems can be solved by a production method having the following steps [1] to [3]. It came to be completed.

  That is, this invention is a manufacturing method of the laminated body which laminates | stacks two or more to-be-adhered bodies which have the surface which an active energy ray does not permeate | transmit through an adhesive sheet, and the 1st surface of the adhesive bond layer of an adhesive sheet, The process [1] for bonding the first adherend to the adhesive body by pressure-sensitive adhesion, and the active energy ray is irradiated to the other surface of the adhesive layer of the adhesive sheet before or after the process of [1]. Then, the step [2] for improving the curing rate of the adhesive layer by 0.01% or more, and the second surface of the adhesive layer of the adhesive sheet and the second adherend are bonded by pressure-sensitive adhesion. It is a manufacturing method of the laminated body which contains process [3] and the process [4] which further hardens the hardening rate of the said adhesive bond layer 3% or more from the hardening rate of said process [2].

  In the step [1] of the present invention, temporary fixing to the first surface of the adhesive layer of the adhesive sheet and the first adherend is easy, and reattachment can be easily performed.

  In the step [2] of the present invention, the adherends can be laminated even after being irradiated with active energy rays because they have adhesiveness necessary for bonding even after irradiation with active energy rays. is there.

  In step [3] of the present invention, temporary fixing to the first surface of the adhesive layer of the adhesive sheet and the second adherend is easy, and reattachment can be easily performed.

  By using the step [4] of the present invention, damage to the liquid crystal display device due to heating at a high temperature is suppressed, and due to the difference in thermal expansion of each member, the adhesion is caused by the strain between the members generated during cooling. Deformation of the body and peeling due to cracks generated between the adhesive sheet and the adherend can be suppressed, and the adherends can be firmly bonded to each other with the predetermined curing rate. .

  The production method of the present invention is a production method of a laminate in which two or more adherends having a surface that does not transmit active energy rays are laminated via an adhesive sheet, and the first surface of the adhesive layer of the adhesive sheet A step [1] of bonding the first adherend and the first adherend to the other surface of the adhesive layer of the adhesive sheet with an active energy ray before or after the step [1]. Then, the step [2] for improving the curing rate of the adhesive layer by 0.01% or more, and bonding the second surface of the adhesive layer of the adhesive sheet and the second adherend by pressure-sensitive adhesion Step [3], and a step [4] of further curing 3% or more of the curing rate of the adhesive layer from the curing rate of the step [2].

  The adherend having a surface through which the active energy ray does not pass is an adherend having a light transmittance of 30% or less at a wavelength of 200 nm to 780 nm, for example, a metal such as aluminum, stainless steel, copper, or glass. Examples thereof include an epoxy substrate, a colored film base material, and a colored glass base material.

  In the step [1], the first surface of the adhesive layer of the adhesive sheet and the first adherend are bonded by pressure-sensitive adhesion. Since this step [1] can be carried out in a timely manner even at a temperature in the working environment, temporary fixing to the first adherend is easy, and reattachment can be easily performed.

  The pressure used for the pressure-sensitive adhesion in the step [1] is preferably 0.1 to 3000 kPa, more preferably 0.5 to 1000 kPa, and further preferably 1.0 to 500 kPa. . By setting it as the said range, the adhesiveness required in order to obtain high joining strength can be obtained, without damaging a 1st to-be-adhered body.

  The temperature used for pressure-sensitive adhesion in the step [1] is preferably 5 to 100 ° C, more preferably 10 to 70 ° C, and further preferably 20 to 40 ° C. By setting it as the said range, the adhesiveness required in order to obtain high joining strength can be obtained, without damaging a 1st to-be-adhered body.

  In the step [2], an active energy ray is irradiated to the other surface of the adhesive layer of the adhesive sheet before or after the step [1], so that the curing rate of the adhesive layer is 0.01 to 30. %Improve. In this step [2], the adherends can be laminated even after being irradiated with active energy rays because they have adhesiveness necessary for bonding even after irradiation with active energy rays.

The irradiation intensity of the active energy ray, preferably 0.1~1000mW / cm ^2, more preferably 0.5～800MW, more preferably 0.1~400mW / cm ^2. By setting it as the said predetermined | prescribed intensity | strength, since the heat | fever produced when an active energy ray is irradiated can be reduced, it becomes possible to adjust suitably the hardening rate after irradiating an active energy ray.

  The irradiation time of the active energy ray is preferably 1 to 60 seconds, more preferably 5 to 50 seconds, and more preferably 10 to 40 seconds. By setting it as the said predetermined time, since the heat | fever which arises when irradiated with an active energy ray can be reduced, the hardening rate after irradiating an active energy ray can be adjusted suitably.

  The irradiation time of the active energy rays may be collectively irradiated or may be divided and irradiated. When dividing and irradiating, for example, 1 minute of irradiation may be divided into 2 times, and 30 seconds may be irradiated twice. By dividing, the heat generated when the active energy ray is irradiated can be reduced, so that the curing rate after the active energy ray is irradiated can be suitably adjusted.

  In the step [2], the curing rate of the adhesive sheet after irradiation with the active energy ray is improved by 0.01% or more. Incidentally, to improve the curing rate by 1% means that when the curing rate in the step [1] is 1%, it becomes 2% (the same applies hereinafter). By setting the curing rate, the adhesive sheet has adhesiveness necessary for pasting even after irradiation with active energy rays, so that adherends can be laminated even after irradiation with active energy rays. Is possible. In addition, since the adhesive sheet has flexibility necessary for step following even after irradiation with active energy rays by setting the curing rate, for example, at least one of the adherends is bent and / or uneven. In the adherend stacking step, the adhesive sheet can follow the bending and / or the unevenness. In the step [2], in order to enhance the effect, it is preferable to improve the curing rate by 0.1 to 60%, more preferably improve the curing rate by 0.2 to 40%, and 0.5 to More preferably, the 20% cure rate is improved.

  The curing rate is represented by a gel fraction, and the gel fraction was immersed in toluene adjusted to 23 ° C. for 24 hours and remained in the solvent. The mass after drying of the adhesive bond layer of an adhesive sheet and the value computed based on the following formulas are pointed out.

  Gel fraction (mass%) = {(mass of adhesive layer of adhesive sheet remaining without being dissolved in toluene) / (mass of adhesive layer of adhesive sheet before immersion in toluene)} × 100

  In the step [2], the curing reaction of the adhesive sheet is started by irradiating active energy rays. Other means for initiating the curing reaction include heating, moisture absorption (water absorption), etc., but by using an active energy ray, it can be applied to a member that may be deteriorated by heating, and the adhesive sheet in the lamination process Hygroscopic management becomes unnecessary.

  It is preferable to use ultraviolet rays as the active energy rays. The ultraviolet rays may be irradiated in an inert gas atmosphere such as nitrogen gas or an air atmosphere in order to efficiently perform the curing reaction by the ultraviolet rays. In addition, if necessary, heat may be used as an energy source, and the active energy ray may be irradiated and then heated.

  When ultraviolet rays are used as the active energy ray, low pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, metal halide lamp, electrodeless lamp (fusion lamp), chemical lamp, black light lamp, mercury-xenon lamp, short arc lamp , Helium / cadmium laser, argon laser, sunlight, LED and the like. Further, the LED is preferable because the amount of heat generated during irradiation is small and the influence of heat on the base material can be minimized.

  As the active energy ray irradiation apparatus, in addition to those described above, a germicidal lamp, a carbon arc, a xenon lamp, a metal halide lamp, a scanning type, a curtain type electron beam accelerator, and the like can be used.

  Examples of the method of irradiating the active energy ray include a method of directly irradiating the adhesive sheet, or a method of irradiating the active energy ray through a base material previously laminated on the adhesive sheet. In that case, the said base material etc. need to be transparent, As a said base material, the peeling liner etc. which are mentioned later are mentioned, for example.

  In the step [3], the second surface of the adhesive layer of the adhesive sheet and the second adherend are bonded together by pressure-sensitive adhesion. Since this step [3] can be carried out in a timely manner even at a temperature in the working environment, it can be easily temporarily fixed to the second adherend and can be easily reattached.

  The pressure used for pressure-sensitive adhesion in the step [3] is preferably a pressure of 0.1 to 3000 kPa, more preferably 0.5 to 1000 kPa, and even more preferably 1.0 to 500 kPa. . By setting it as the said range, the adhesiveness required in order to obtain high joining strength can be obtained, without damaging a 1st to-be-adhered body.

  The temperature used for the pressure-sensitive adhesion in the step [3] is preferably 5 to 100 ° C, more preferably 10 to 70 ° C, and further preferably 20 to 40 ° C. By setting it as the said range, the adhesiveness required in order to obtain high joining strength can be obtained, without damaging a 1st to-be-adhered body.

  In the step [4], the curing rate of the adhesive layer is further improved by 3% or more from the curing rate in the step [2] by curing at a temperature of 20 to 100 ° C. for 30 minutes to 7 days. In the production method of the present invention, the curing reaction of the adhesive sheet is started by irradiating active energy rays, and thus the curing proceeds even at room temperature. However, the curing time can be shortened by heating as necessary.

  In the step [4], the cured product formed by curing the adhesive sheet is preferably improved by 10% or more. By setting it as the said hardening rate, it becomes possible to obtain the adhesive bond layer which can join members firmly. The curing rate of the adhesive sheet is more preferably 20% or more, further preferably 30% or more, and most preferably 60% or more.

  The curing rate is represented by a gel fraction, and the gel fraction was immersed in toluene adjusted to 23 ° C. for 24 hours and remained in the solvent. The mass after drying of the adhesive bond layer of an adhesive sheet and the value computed based on the following formulas are pointed out.

  Gel fraction (mass%) = {(mass of adhesive layer of adhesive sheet remaining without being dissolved in toluene) / (mass of adhesive layer of adhesive sheet before immersion in toluene)} × 100

  The curing temperature of the step [4] is preferably 30 to 100 ° C, more preferably 40 to 90 ° C, and further preferably 50 to 80 ° C. By setting the predetermined range, it is possible to obtain the adhesiveness necessary to suitably deform the thickness and obtain a high bonding strength without suppressing damage to the liquid crystal display device due to heating. Further preferred.

  The curing time in the step [4] is preferably 10 minutes to 7 days, more preferably 15 minutes to 1 day, more preferably 20 minutes to 3 hours, and more preferably 1 to 2 hours. Curing suppresses damage to the members of the liquid crystal display device due to heating at a high temperature, and due to the difference in thermal expansion of each member, deformation of the adherend due to strain between the members caused by cooling, and an adhesive sheet And peeling due to a crack generated between the adherends can be suppressed.

  The step [4] is preferably performed within 60 minutes after the step [2] is completed. More preferably, it is within 5 to 45 minutes, and more preferably within 10 to 30 minutes. In order to ensure the preparation time until it transfers to the process [4] from the said process [2] by setting it as the said predetermined range, and in the said process [4], in order to make the said adhesive sheet adhere | attach an adherend Necessary tackiness and flexibility can be imparted.

As the adhesive layer of the adhesive sheet used in the production method, the loss tangent (tan δ ₂₃ ) at 23 ° C. of the adhesive layer before curing is preferably less than 3.0.

The loss tangent (tan δ ₂₃ ) at 23 ° C. was tested between parallel disks, which are measuring units, using a dynamic viscoelasticity tester (manufactured by Rheometrics, trade name: Ares 2KSTD). The storage elastic modulus (G ′) and loss elastic modulus (G ″) at a temperature of 0 to 150 ° C. and a frequency of 1 Hz are measured, and the loss tangent (tan δ) is the loss elastic modulus (G ″). It is a value (G ″ / G ′) divided by the storage elastic modulus (G ′). As a test piece used in the above measurement, the adhesive layer has a thickness of 1 mm and a diameter of 8 mm. The one cut into a circle was used.

The adhesive layer of the adhesive sheet is more preferably less than 1.5 or less when the loss tangent (tan δ ₂₃ ) at 23 ° C. of the adhesive layer before curing is measured at a frequency of 1 Hz. A range of 1.0 or less is more preferable, and a range of 0.1 or more and 0.8 or less is particularly preferable. By setting it as the said range, in the said process [1] and process [2], the manufacturing method which kept the thickness of the adhesive sheet constant and improved the handleability at the time of bonding an adhesive sheet can be obtained.

In addition, the loss tangent (tan δ ₂₃ ) at 23 ° C. of the adhesive layer before curing of the adhesive sheet is in addition to the conditions at the time of production, the photocurable resin (A) and the thermoplastic resin (B) described later. If necessary, the composition of other components, the number average molecular weight, and the like can be set within a predetermined range in the previous period by appropriately selecting the composition.

Moreover, the manufacturing method of the laminated body of this invention WHEREIN: Between said process [1] and process [2], between said process [1] and process [3], and at least said process [3] and process [4]. It is preferable to have a step [5] of forming a state in which the adhesive sheet is crushed in one. By crushing the adhesive sheet, it is possible to improve the adhesion to the adherend, for example, even if the adherend has a bend or unevenness on the surface, the adhesive sheet is made to follow the bend or unevenness, It can be suitably adhered.

  Further, in the step [5], by adjusting the temperature, pressure, and time described later as appropriate, for example, the thickness after the adhesive sheet can be reduced by 10% or more of the original thickness. In the step of laminating the adherend so that at least one of the adherends has a bend and / or unevenness, the adhesive sheet can sufficiently follow the bend and / or unevenness. Moreover, in order to make it adhere | attach with a to-be-adhered body, making the thickness of the said adhesive sheet 10% or more of the original thickness, the hardening rate after irradiating the active energy ray in process [2] mentioned above is said predetermined | prescribed It is necessary to make it a preferable range.

  In the step [5], the temperature at which the adhesive sheet is crushed is necessary to bring the adhesive sheet into close contact with the adherend and to change the thickness. It is preferable that it is -100 degreeC, It is more preferable that it is 40 degreeC-90 degreeC, It is further more preferable that it is 50-80 degreeC. By setting the predetermined range, the sheet shape is maintained in the steps [1], [2], and [3], and the thickness is suitably adjusted without suppressing damage to the liquid crystal display device due to heating. It is more preferable because the adhesiveness necessary for deformation and high bonding strength can be obtained.

  In the step [5], the pressure for crushing the adhesive sheet is necessary to bring the adherent sheet into close contact with the adherend and to change the thickness. The pressure is preferably from 1 to 3000 kPa, more preferably from 0.5 to 1000 kPa, and even more preferably from 1.0 to 500 kPa. By setting it as the said range, adhesiveness required in order to deform | transform thickness suitably and to obtain high joining strength can be obtained, without damaging the member of the liquid crystal display device by pressurization.

  In the step [5], the time for crushing the adhesive sheet is necessary for bringing the adherent sheet into close contact with the adherend and changing the thickness, and the time can be adjusted as appropriate for joining. It is preferably from 2 to 20 minutes, more preferably from 30 to 15 minutes, and preferably from 1 to 10 minutes, with the thickness being suitably deformed and high without damaging the adherend. It is more preferable because the adhesion necessary for obtaining the bonding strength can be obtained.

  For example, when the step [5] is performed after the step [2], the step [5] is preferably performed within 60 minutes after the step [2] is completed. More preferably, it is within 5 to 45 minutes, and more preferably within 10 to 30 minutes. By setting the predetermined range, it is possible to secure a preparation time from the step [2] to the transition to the step [3], and to provide flexibility necessary for crushing the adhesive sheet in the step [5]. It becomes possible to grant.

  As the adhesive layer of the adhesive sheet, it is preferable to use an adhesive layer having a melting point below the operating temperature of the step [5]. Those having a melting point in the above range can suitably reduce the thickness of the hard adhesive sheet, and can obtain an improved manufacturing method with improved flexibility of the member and followability to the stepped portion of the surface. .

  The melting point is determined by using a differential scanning calorimetry method (DSC method) from 30 ° C. to 150 ° C. under a temperature rising rate of 10 ° C./min, held for 1 minute, and then 10 ° C. The temperature indicates the maximum exothermic peak (exothermic peak top) that is observed when the temperature is once lowered to −10 ° C. under a temperature-decreasing condition per minute, held for 10 minutes, and then measured again under the temperature-raising condition at 10 ° C./min. .

  As the adhesive layer of the adhesive sheet used in the production method, a composition containing a polymerizable compound or the like described later can be used, but the polymerizable compound is particularly limited if polymerization is induced by an external stimulus. Not done.

  As the adhesive layer of the adhesive sheet used in the manufacturing method, it is preferable to use one having a thickness in the range of 50 to 2000 μm, more preferably 100 to 1500 μm, and 200 to 1000 μm. In the step [1] and step [2], the thickness of the adhesive sheet is kept constant, the handling property when the adhesive sheet is bonded is improved, and the adhesion in the step [5] is used. It is preferable to obtain a manufacturing method that can suitably reduce the thickness of the sheet and improve the flexibility of the member and the followability to the stepped portion of the surface.

  As the adhesive layer of the adhesive sheet used in the manufacturing method, it is preferable to use a photopolymerizable adhesive layer having a photocurable resin (A), a thermoplastic resin (B), and a photopolymerization initiator.

  As the photopolymerizable adhesive layer, an active energy ray (light) is applied as an external stimulus in the step [2] to activate the polymerizable functional group of the photopolymerizable adhesive layer. ], The curing can proceed at a low temperature. Further, the curing can be progressed in a short time in the step [4] as compared with a state where the activation is not performed.

  As the photopolymerizable adhesive layer, curing does not proceed regardless of the storage temperature as long as the active energy ray is not irradiated, the storage stability is good, and the reactive site can be formed without heating. Since it can be activated, the curing can proceed at a low temperature. Moreover, you may use together external stimuli other than an active energy ray.

  For example, heat may be used in combination as an external stimulus other than the active energy ray. When heat is used in combination, the reaction has started to proceed due to the light, so heat is used only for the purpose of accelerating the curing reaction, and it is not necessary to heat at a high temperature. Can be cured.

  It is preferable that the photocurable resin (A) and the thermoplastic resin (B) contained in the photopolymerizable adhesive layer have a polymerizable functional group other than the unsaturated double bond. Accordingly, since rapid curing reaction can be suppressed after the irradiation with active energy rays in the step [2] and the curing reaction can be gradually advanced, the step [1] is performed even after irradiation with active energy rays. ] Or [3] can have adhesiveness necessary for bonding. As a result, it is possible to laminate the adhesive composition and the members after irradiation with active energy rays.

  In the case of the photopolymerizable adhesive layer, for example, the curing gradually proceeds after irradiation with active energy rays, and thus has adhesiveness necessary for bonding even after irradiation with active energy rays. It is possible to bond even on adherends that cannot pass through.

  As the photocurable resin (A), a photocationically polymerizable compound or a photoanion polymerizable compound is preferably used. By using the photocationic polymerizable compound or the photoanionic polymerizable compound, the reaction is not inhibited by oxygen during curing, and the reaction proceeds continuously after irradiation. By laminating, it is possible to laminate even a member that does not transmit active energy rays. In particular, it is more preferable to use a cationically polymerizable compound because it is excellent in reactivity after light irradiation and easy to obtain high bondability after curing. The photopolymerizable compounds may be used alone or in combination.

  The photocationically polymerizable compound is not particularly limited as long as it has one or more photocationically polymerizable functional groups in one molecule. As the photocationically polymerizable compound, one or more epoxy groups, oxetanyl groups, hydroxyl groups, vinyl ether groups, episulfide groups, ethyleneimine groups, oxazoline groups, and the like are included in one molecule. It is preferable. Among these, in order to obtain high curability and bondability after curing, the photocationically polymerizable compound is more preferably one having an epoxy group or an oxetanyl group.

  As the photocationic polymerizable compound having an epoxy group, a compound having one or more epoxy groups in one molecule can be used. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, polyhydroxynaphthalene type epoxy resin, isocyanate modified epoxy resin, 10- (2,5-dihydroxyphenyl) ) -9,10-dihydro 9-oxa-10-phosphaphenanthrene-10-oxide modified epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, hexanediol type epoxy resin, triphenylmethane type epoxy resin, tetra Phenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolak type epoxy resin, naphthol aral Kill type epoxy resin, naphthol-phenol co-condensed novolak type epoxy resin, naphthol-cresol co-condensed novolac type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenolic resin type epoxy resin, biphenyl modified novolak type epoxy resin, trimethylolpropane type epoxy resin A resin, an alicyclic epoxy resin, an acrylic resin having an epoxy group, a polyurethane resin having an epoxy group, a polyester resin having an epoxy group, an epoxy resin having flexibility, and the like can be used.

  Especially, as said epoxy resin, it is preferable to use an alicyclic epoxy resin and a polyfunctional aliphatic epoxy resin, and it is more preferable to use an alicyclic epoxy resin. Since these have excellent photocationic polymerizability, a bonding material having excellent curability can be obtained, and the time required for the step [4] can be shortened. Moreover, the suitable elasticity modulus for suppressing a time-dependent deformation | transformation of the adhesive bond layer after joining can be provided.

  Furthermore, it may be possible to increase flexibility by adding or adding other resin components to these, or to improve the adhesive force or bending force. As such a modified body, CTBN (terminal Carboxyl group-containing butadiene-acrylonitrile rubber) modified epoxy resin; epoxy resin in which various rubbers such as acrylic rubber, NBR, SBR, butyl rubber or isoprene rubber are dispersed; epoxy resin modified with liquid rubber as described above; acrylic An epoxy resin obtained by adding various resins such as urethane, urea, polyester, and styrene; a chelate-modified epoxy resin; a polyol-modified epoxy resin can be used.

  Examples of the photocationically polymerizable compound having an oxetanyl group include 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene and 1,4-bis [(3-methyl-3-oxetanylmethoxy) methyl. ] Benzene, 3-methyl-3-glycidyl oxetane, 3-ethyl-3-glycidyl oxetane, 3-methyl-3-hydroxymethyl oxetane, 3-ethyl-3-hydroxymethyl oxetane, di {1-ethyl (3-oxetanyl) )} Oxetane compounds such as methyl ether.

  The photocurable resin (A) is preferably used in the range of 10% by mass to 70% by mass, and in the range of 20% by mass to 40% by mass with respect to the total amount of the photopolymerizable adhesive layer. However, even when the adhesive sheet made of, for example, a photopolymerizable adhesive layer is wound around a roll and stored, the adhesive layer is removed from the end of the roll. Extrusion can be further prevented, and it is more preferable because an adhesive composition can be obtained in which the bending of the member and the followability to the stepped portion on the surface are further improved.

  Moreover, the photopolymerizable adhesive layer of the present invention contains a thermoplastic resin (B). The thermoplastic resin (B) has a polymerizable functional group other than the unsaturated double bond. By using the thermoplastic resin (B) having a polymerizable functional group other than the unsaturated double bond, it becomes possible to react with the polymerizable compound (A) and irradiated with active energy rays. Since the subsequent rapid curing reaction can be suppressed and the curing reaction can be allowed to proceed gradually, it is possible to have flexibility necessary for bonding even after irradiation with active energy rays in the step [2]. As a result, it is possible to laminate the adhesive composition and the members after applying the active energy ray in the step [1] or [3].

  The polymerizable functional group of the thermoplastic resin (B) preferably has at least one selected from the group consisting of an isocyanate group, a hydroxyl group, an oxetanyl group, and an epoxy group. By using the thermoplastic resin (B) having at least one selected from the group consisting of the isocyanate group, hydroxyl group, oxetanyl group and epoxy group, it becomes possible to react with the polymerizable compound (A). In addition, since it is possible to suppress a rapid curing reaction after irradiation with active energy rays and to gradually advance the curing reaction, it is necessary for bonding even after irradiation with active energy rays in the step [2]. It can have flexibility. As a result, it is possible to laminate the adhesive composition and the members after applying the active energy ray in the step [1] or [3].

The thermoplastic resin (B) preferably has a loss tangent (tan δ ₄₀ ) at 40 ° C. of less than 3.0 and a loss tangent (tan δ ₆₀ ) at 60 ° C. of 1.5 or more.

As the thermoplastic resin (B), it is more preferable to use a resin whose loss tangent (tan δ ₄₀ ) at 40 ° C. is less than 1.5 when measured at a frequency of 1 Hz. Is more preferably in the range of not more than 0.0, particularly preferably in the range of not less than 0.1 and not more than 0.8. By setting the above range, the shape of the adhesive sheet before curing is more stable. Therefore, the handleability of the adhesive sheet is improved, and the workability of the steps [1], [2], and [3] is improved. Further, for example, even when the adhesive sheet made of the photopolymerizable adhesive layer containing the thermoplastic resin (B) is wound around a roll or the like and stored, the adhesive layer is extruded from the end of the roll. Can be further prevented, and a photopolymerizable adhesive layer with improved flexibility of the member and followability to the stepped portion of the surface can be obtained.

As the thermoplastic resin (B), it is excellent in handleability before curing that the loss tangent (tan δ ₆₀ ) at 60 ° C. is 1.5 or more when measured at a frequency of 1 Hz. The adhesive sheet comprising the photopolymerizable adhesive layer containing the thermoplastic resin (B) is wound around a roll or the like, and even when it is stored, the adhesive layer can be prevented from being extruded from the end of the roll, And it is preferable when obtaining the photopolymerizable adhesive layer which improved the followability to the bending of a member and the surface level | step difference part, It is more preferable to use what is 5.0 or more, and is 10.0 or more It is further preferable to use a material in order to obtain a photopolymerizable adhesive layer in which the flexibility of the member and the followability to the stepped portion on the surface are further improved.

The loss tangent at 40 ° C. (tan δ ₄₀ ) and the loss tangent at 60 ° C. (tan δ ₆₀ ) were measured using a dynamic viscoelasticity tester (Rheometrics, trade name: Ares 2KSTD). A test piece is sandwiched between parallel disks as measurement parts, and the storage elastic modulus (G ′) and loss elastic modulus (G ″) at a temperature of 40 ° C. or 60 ° C. and a frequency of 1 Hz are measured, and the loss tangent (tan δ) ) Is a value (G ″ / G ′) obtained by dividing the loss elastic modulus (G ″) by the storage elastic modulus (G ′). As the test piece used in the measurement, the adhesive layer is What was cut into a circle having a thickness of 1 mm and a diameter of 8 mm was used.

The loss tangent (tan δ ₄₀ ) at ₄₀ ° C. and the loss tangent (tan δ ₆₀ ) at 60 ° C. of the thermoplastic resin (B) are, for example, when a urethane resin is used, such as polyol and polyisocyanate constituting the urethane resin By appropriately selecting the composition, its number average molecular weight, etc., it can be set within a predetermined range in the previous period.

  Moreover, as said thermoplastic resin (B), it is preferable to use what has melting | fusing point in the range of 30 to 120 degreeC, what has melting | fusing point in the range of 35 to 100 degreeC is more preferable, and 40 to Those having a melting point in the range of 80 ° C. are excellent in handling properties before curing. For example, an adhesive sheet comprising a photopolymerizable adhesive layer containing the thermoplastic resin (B) is wound around a roll or the like and stored. Even in this case, the adhesive layer can be prevented from being pushed out from the end of the roll, and for example, in the step [5], it is easy to improve the flexibility of the member and the followability to the stepped portion of the surface. It is preferable because a simple adhesive layer can be obtained.

  The melting point is determined by using a differential scanning calorimetry method (DSC method) from 30 ° C. to 150 ° C. under a temperature rising rate of 10 ° C./min, held for 1 minute, and then 10 ° C. The temperature indicates the maximum exothermic peak (exothermic peak top) that is observed when the temperature is once lowered to −10 ° C. under a temperature-decreasing condition per minute, held for 10 minutes, and then measured again under the temperature-raising condition at 10 ° C./min. .

  Moreover, as said thermoplastic resin (B), it is excellent in the handleability before hardening, for example, even when it winds up the adhesive sheet which consists of the said photopolymerizable adhesive bond layer on a roll etc., and stored it An adhesive that can further prevent the adhesive layer from being pushed out from the end of the roll, and that can easily improve, for example, the bending of the member and the followability to the stepped portion of the surface in the step [5]. In order to obtain a layer, it is preferable to use an adhesive resin having a weight average molecular weight in the range of 2,000 to 2,000,000. A more preferable range of the weight average molecular weight is 5000 to 1000000, and a further preferable range of the weight average molecular weight is 5000 to 800000. If the weight average molecular weight is too small, the cohesive force of the photopolymerizable adhesive layer before curing is insufficient, and the handleability deteriorates due to the occurrence of bleeding of the photopolymerizable adhesive layer over time. Moreover, when a weight average molecular weight is too large, compatibility with the said photocurable resin (A) may fall.

  Examples of the thermoplastic resin (B) include polyester resins, urethane resins, acrylic resins, and polyvinyl acetal resins. These adhesive resins may be a homopolymer or a copolymer. Moreover, these adhesive resins may be used independently and 2 or more types may be used together.

  As the thermoplastic resin (B), use of a urethane resin or an acrylic resin is excellent in handleability before curing, and for example, an adhesive sheet made of a photopolymerizable adhesive layer is wound around a roll or the like, Even when stored, it is possible to further prevent the adhesive layer from being pushed out from the end of the roll, and to obtain an adhesive composition in which the flexibility of the member and the followability to the stepped portion of the surface are further improved. More preferably, it is more preferable to use a urethane resin (B ′).

  The urethane resin (B ′) preferably has a polymerizable functional group other than the polymerizable unsaturated double bond.

  By using a urethane resin (B ′) having a polymerizable functional group other than the unsaturated double bond, it is possible to suppress a rapid reaction when the adhesive composition is irradiated with active energy rays. It is possible to join members after irradiating active energy rays.

  As the external stimulus, it is preferable to use an active energy ray. When a cured product is formed by advancing a polymerization reaction, by using a urethane resin (B ′) having a polymerizable functional group other than the unsaturated double bond, not only by polymerization by light irradiation but also by a dark reaction. Since the polymerization can proceed, for example, members that cannot transmit active energy rays can be joined together.

  As the external stimulus, in addition to the light, heat may be used in combination as necessary. In this case, since the progress of the reaction is started by the light, heat is used only for the purpose of accelerating the curing reaction, it is not necessary to heat at a high temperature, and a good curing reaction even at a low temperature and in a short time. Can be obtained.

  The polymerizable functional group other than the unsaturated double bond preferably has at least one selected from the group consisting of an isocyanate group, a hydroxyl group, an oxetanyl group, and an epoxy group.

  As the urethane resin (B ′) having an isocyanate group, for example, a urethane resin (B′1) having an isocyanate group obtained by reacting a polyol (b′1) with a polyisocyanate (b′2). Can be used.

  As the urethane resin (B ′) having a hydroxyl group, for example, a urethane resin (B′2) having a hydroxyl group obtained by reacting a polyol (b′1) and a polyisocyanate (b′2) is used. be able to.

  Examples of the urethane resin (B ′) having an oxetanyl group or an epoxy group include a urethane resin (B′1) having the isocyanate group and a functional group (b ″ 1) capable of reacting with the isocyanate group, Urethane resin (B′3) obtained by reacting a monomer (B ″) having a polymerizable functional group (b ″ 2) other than oxetanyl group or epoxy group and at least one unsaturated double bond Can be used.

  As the functional group (b ″ 1) capable of reacting with the isocyanate group, for example, a hydroxyl group, an amino group, a carboxyl group, a mercapto group and the like can be used, and a hydroxyl group and an amino group are preferably used.

  The polymerizable functional group (b ″ 2) other than the unsaturated double bond polymerizable unsaturated double bond refers to other than the functional group having so-called radical polymerizable property, for example, a functional group having cationic polymerizable property, It is a functional group having anionic polymerizability.

  In addition, as the polymerizable functional group (b ″ 2) other than the unsaturated double bond polymerizable unsaturated double bond, for example, an epoxy group, an oxetanyl group, an ethylene sulfide group, and the like can be used. It is preferable to use it.

  The monomer (B ″) has a functional group (b ″ 1) capable of reacting with the isocyanate group and an oxetanyl group or an epoxy group and a polymerizable functional group (b ″ 2) other than the unsaturated double bond. For example, 3-ethyl-3- (4-hydroxybutyl) oxymethyl-oxetane, 3-hydroxymethyl-3-ethyloxetane, 2-hydroxymethyloxetane, 3 -Hydroxyoxetane etc. are mentioned.

  The monomer (B ″) is preferably used in a range of 5 to 20 parts by mass with respect to 100 parts by mass of the urethane resin (B ′), and in a range of 5 to 15 parts by mass. It is more preferable to use in.

  More specifically, the monomer (B ″) is preferably more than 50 mol% and not more than 100 mol%, more preferably, relative to the number of moles of isocyanate groups of the urethane resin (B ′). 60 mol% to 100 mol%, more preferably 80 mol% to 100 mol% of an amount capable of supplying a functional group capable of reacting with the isocyanate group can be used. It is possible to obtain the thermoplastic resin (B) excellent in fast curability, shape retention after application to the substrate, mechanical strength, durability (particularly hydrolysis resistance), adhesion to the substrate, etc. it can.

  When the urethane resin (B ′) and the monomer (B ″) are reacted, a urethanization catalyst can be used as necessary. The urethanization catalyst is used for the urethanization reaction. The urethanization reaction is preferably carried out until the isocyanate group content (%) becomes substantially constant.

  Examples of the urethanization catalyst include nitrogen-containing compounds such as triethylamine, triethylenediamine and N-methylmorpholine, organometallic salts such as potassium acetate, zinc stearate and stannous octylate, and organometallic compounds such as dibutyltin dilaurate. Etc. can be used.

  Moreover, as said polyol (b'1) which can be used for manufacture of the said polyurethane, 1 or more types chosen from the group which consists of polycarbonate polyol, polyester polyol, polyether polyol, etc. can be used. Especially, as said polyol (b'1), it is preferable to use a polycarbonate polyol and a polyester polyol individually or in combination of 2 or more types, and using a polyester polyol or a combination of a polycarbonate polyol and a polyester polyol before curing is preferable. For example, the adhesive layer of the photopolymerizable adhesive layer containing the urethane resin (B ′) is wound around a roll or the like, and the adhesive layer can be removed from the end of the roll even when stored. It is more preferable because it can prevent the extrusion further and can obtain a photopolymerizable adhesive layer in which the bending of the member and the followability to the stepped portion of the surface are further improved.

  As said polycarbonate polyol, what is obtained by making carbonate ester and / or phosgene react with the low molecular polyol mentioned later, for example can be used.

  As the carbonate ester, for example, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like can be used.

  Examples of the low molecular polyol that can react with the carbonate ester or phosgene include, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene, and the like. Propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexane Diol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol 2-methyl-1,3-propanediol Neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octane Diol, 1,4-cyclohexanedimethanol, hydroquinone, resorcin, bisphenol A, bisphenol F, 4,4′-biphenol, and the like can be used.

  As the polycarbonate polyol, an aliphatic polycarbonate polyol or an alicyclic polycarbonate polyol is preferably used.

  Examples of the aliphatic polycarbonate polyol include a photopolymerizable adhesive layer containing the urethane resin (B ′), for example, a dialkyl carbonate and 1,4-butane for imparting a level of tackiness that can be applied at room temperature. It is possible to use those obtained by reacting one or more polyols selected from the group consisting of diol, 1,5-pentanediol, 3-methyl-1,5-pentanediol and 1,6-hexanediol. preferable.

  As an alicyclic polycarbonate polyol, for example, the photopolymerizable adhesive layer adhesive sheet containing the urethane resin (B ′) is given a level of tackiness that can be applied at room temperature, for example, and has excellent initial cohesive strength. In doing so, it is preferable to use, for example, a product obtained by reacting a dialkyl carbonate with a polyol containing one or more selected from the group consisting of cyclohexanedimethanol and derivatives thereof.

As the polycarbonate polyol, a urethane resin having a loss tangent (tan δ ₄₀ and tan δ ₆₀ ) within the predetermined range is formed, and is excellent in handleability before curing, for example, photopolymerizability including the urethane resin (B ′) Even when the adhesive sheet of the adhesive layer is wound around a roll or the like and stored, the adhesive layer can be further prevented from being pushed out from the end of the roll, and the bending of the member or the stepped portion of the surface can be prevented. In order to obtain an adhesive sheet that further improves the follow-up property, it is preferable to use one having a number average molecular weight in the range of 500 to 5,000, and one having a number average molecular weight in the range of 800 to 3,000. It is preferable.

  The polycarbonate polyol is preferably used in a range of 20% by mass to 80% by mass with respect to the total amount of the polyol (b′1), and more preferably in a range of 30% by mass to 70% by mass. Adhesion using a curable adhesive composition containing the urethane resin (B ′) while maintaining a level of tackiness that can be applied at a light ambient temperature when used in the range of 40 mass% to 50 mass% Even when the adhesive sheet having the adhesive layer is wound around a roll or the like and stored, the adhesive layer can be further prevented from being pushed out from the end of the roll, and the bending of the member or the stepped portion on the surface can be prevented. It is preferable for obtaining an adhesive sheet having further improved followability.

  Examples of the polyester polyol that can be used in the polyol (b′1) include those obtained by esterifying low molecular weight polyols and polycarboxylic acids, and ring-opening polymerization reactions of cyclic ester compounds such as ε-caprolactone. Polyesters obtained by the above, copolymerized polyesters thereof, and the like can be used.

  Examples of the low molecular weight polyol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and 1,3-butane having a molecular weight of about 50 to 300. Aliphatic alkylene glycols such as diols, cyclohexanedimethanol and the like can be used.

  Examples of the polycarboxylic acid that can be used in the production of the polyester polyol include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, and naphthalene dicarboxylic acid. Acid, biphenyldicarboxylic acid, binaphthyldicarboxylic acid, oxydibenzoic acid, carbonyldibenzoic acid, isophthaloyldibenzoic acid, terephthaloyldibenzoic acid and other aromatic dicarboxylic acids, and anhydrides or esterified products thereof can be used.

As the polyester polyol, a urethane resin having a loss tangent (tan δ ₄₀ and tan δ ₆₀ ) within the predetermined range is formed, and is excellent in handleability before curing, for example, photopolymerizability including the urethane resin (B ′). Even when the adhesive sheet of the adhesive layer is wound around a roll or the like and stored, the adhesive layer can be further prevented from being pushed out from the end of the roll, and the bending of the member or the stepped portion of the surface can be prevented. In order to obtain an adhesive sheet with further improved followability to the surface, it is preferable to use an aliphatic polyester polyol, and it is more preferable to use a linear aliphatic polyester polyol. The said linear aliphatic polyester polyol refers to the polyester polyol which does not have an alkyl group in a side chain.

  Examples of the polyester polyol include those obtained by reacting the aliphatic alkylene glycol with an aliphatic dicarboxylic acid, and aliphatic polyester polyols obtained by esterifying 1,6-hexanediol and adipic acid. Is preferably used.

As the polyester polyol, a urethane resin having a loss tangent (tan δ ₄₀ and tan δ ₆₀ ) within the predetermined range is formed, and is excellent in handleability before curing, for example, photopolymerizability including the urethane resin (B ′). Even when the adhesive sheet of the adhesive layer is wound around a roll or the like and stored, the adhesive layer can be further prevented from being pushed out from the end of the roll, and the bending of the member or the stepped portion of the surface can be prevented. In order to obtain an adhesive sheet that further improves the follow-up property, it is preferable to use a sheet having a number average molecular weight in the range of 1000 to 5000.

  In particular, when the polyester polyol obtained by reacting an aliphatic diol such as 1,2-ethanediol or 1,4-butanediol with adipic acid is used as the polyester polyol, the range is from 1100 to 2900. It is preferable to use a polyester polyol obtained by reacting 1,6-hexanediol with adipic acid, having a number average molecular weight in the range of 1100 to 5000. It is preferable to use a polyester polyol, and when a polyester polyol obtained by reacting 1,6-hexanediol and sebacic acid is used, a polyester polyol having a number average molecular weight in the range of 1000 to 5000 is preferably used. preferable.

  The polyester polyol is preferably used in a range of 10% by mass to 70% by mass with respect to the total amount of the polyol (b′1), and is preferably used in a range of 20% by mass to 60% by mass at room temperature. Even when the adhesive sheet of the photopolymerizable adhesive layer containing the urethane resin (B ′) is wound around a roll or the like and stored, the adhesive is maintained. It is preferable for obtaining an adhesive sheet that can further prevent the layer from being pushed out from the end of the roll and further improve the flexibility of the member and the followability to the stepped portion of the surface.

  As the polyol (b′1), it is preferable to use a combination of the polycarbonate polyol and the polyester polyol.

  As for the said polycarbonate polyol and the said polyester polyol, it is preferable to use what contains a total of 20 mass parts or more with respect to 100 mass parts of the said polyol (b'1), and uses what contains 50 mass parts or more. The adhesive sheet of the photopolymerizable adhesive layer containing the urethane resin (B ′) was wound around a roll or the like, and maintained. Even if it is a case, it can prevent further that an adhesive bond layer is extruded from the edge part of a roll, and it is preferable when obtaining the adhesive sheet which improved further the bending | flexion of a member and the followability to the level | step difference part of a surface.

When the polycarbonate polyol and the polyester polyol are used in combination, the [polycarbonate polyol / polyester polyol] (mass ratio) is preferably in the range of 0.4 to 7.0, and 1.0 to 2. A range of 0 forms a urethane resin having a loss tangent (tan δ ₄₀ and tan δ ₆₀ ) within the predetermined range. Even when the photopolymerizable adhesive layer containing urethane resin (B ') is wound around a roll or the like and stored, the adhesive layer can be further prevented from being pushed out from the end of the roll. And it is preferable when obtaining the adhesive sheet which further improved the followability to the bending of a member and the level | step difference part of a surface.

  Moreover, polyether polyol can also be used as said polyol (b'1). As the polyether polyol, for example, one obtained by addition polymerization of alkylene oxide using one or more compounds having two or more active hydrogen atoms as an initiator can be used.

  Examples of the initiator include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, bisphenol A, glycerin, and triglyceride. Methylolethane, trimethylolpropane and the like can be used.

  Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran.

  As the polyether polyol, it is preferable to use an aliphatic polyether polyol or a polyether polyol having an alicyclic structure.

  Examples of the polyether polyol include polytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran, polytetramethylene glycol derivative obtained by reacting tetrahydrofuran and alkyl-substituted tetrahydrofuran, and copolymerization of neopentyl glycol and tetrahydrofuran. Polytetramethylene glycol derivatives and the like can be used. Among them, as the polyether polyol, the adhesive sheet containing the photopolymerizable adhesive layer maintains the level of sticking possible at room temperature, and has excellent flexibility and durability (particularly hydrolysis resistance). ) And the like, it is preferable to use polytetramethylene glycol (PTMG) or polytetramethylene glycol derivative (PTXG).

  In addition, as the polyol (b′1), it is possible to suppress time-dependent displacement and deformation of the adhesive layer after bonding of a cured product (cured adhesive layer) formed by curing the adhesive sheet. For the purpose, it is preferable to use an aromatic polyol. By using the aromatic polyol, the rigidity of the urethane resin (B ′) can be improved.

  Examples of the aromatic polyol include hydroquinone, resorcin, dihydroxyphenyl, naphthalene diol, dihydroxydiphenyl ether, bisphenol F, bisphenol A, and bisphenol A added with an alkylene oxide such as ethylene oxide and propylene oxide (diethoxylated bisphenol). A), p-xylylene glycol, m-xylylene glycol, o-xylylene glycol, 4,4'-bishydroxymethylbiphenyl, 4,2'-bishydroxymethylbiphenyl, 2,2'-bishydroxymethyl Biphenyl, 4,3′-bishydroxymethylbiphenyl, 3,3′-bishydroxymethylbiphenyl, 3,2′-bishydroxymethylbiphenyl, phenol novolac, Resole novolak, 1,4-benzenedimethanol, 1,3-benzenedimethanol, 1,2-benzenedimethanol, 4,4′-naphthalenediethanol, 3,4′-naphthalenediethanol, and modified compounds thereof Etc.

  Further, as the polyol (b′1), other polyols can be used in addition to those described above. As said other polyol, an acrylic polyol etc. are mentioned, for example.

  As said polyol (b'1), it is preferable to use what has a number average molecular weight of the range of 500-5000, and what has a number average molecular weight of the range of 1000-3000 is used for shape retention. It is more preferable for obtaining a photopolymerizable adhesive layer excellent in coating workability, initial cohesive force and the like. The number average molecular weight is a value measured under the following conditions.

[Measurement method of number average molecular weight]
The measurement of the number average molecular weight described in the present invention is a value measured under the following conditions by gel permeation chromatograph (GPC) in terms of polystyrene.

Resin sample solution; 0.4% by mass tetrahydrofuran (THF) solution Measuring device model number: HLC-8220GPC (manufactured by Tosoh Corporation)
Column: TSKgel (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran (THF)

  As the polyisocyanate (b′2) that can be used in the production of the urethane resin (B ′), alicyclic polyisocyanate, aliphatic polyisocyanate, aromatic polyisocyanate and the like can be used.

  Moreover, as said polyisocyanate (b'2), it is preferable to use an alicyclic polyisocyanate in order to obtain the adhesive composition which further improved the flexibility of the member and the follow-up to the level | step difference part of a surface. .

  Examples of the alicyclic polyisocyanate include isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 4,4′-dicyclohexylmethane diisocyanate, 2,4- and / or 2,6-methylcyclohexane diisocyanate, cyclohexyl. Sylene diisocyanate, methylcyclohexylene diisocyanate, bis (2-isocyanatoethyl) -4-cyclohexylene-1,2-dicarboxylate and 2,5- and / or 2,6-norbornane diisocyanate, dimer acid diisocyanate, bicycloheptane Triisocyanate etc. can be used individually or in combination of 2 or more types.

  As the alicyclic polyisocyanate, among the above, in order to obtain an adhesive sheet having good reactivity with the polyol (b′1) and excellent in heat resistance and light transmittance, It is preferable to use 4,4′-dicyclohexylmethane diisocyanate (HMDI), isophorone diisocyanate (IPDI), 1,3-bis (isocyanatomethyl) cyclohexane (BICH).

  As a method for producing the urethane resin (B ′) having an isocyanate group by reacting the polyol (b′1) and the polyisocyanate (b′2), for example, the polyol (b′1) charged in a reaction vessel. Is removed by heating under normal pressure or reduced pressure, and then the polyisocyanate (b′2) is fed in batches or divided to react.

  Reaction of the said polyol (b'1) and the said polyisocyanate (b'2) is equivalent ratio (the isocyanate group which the said polyisocyanate (b'2) has, and the hydroxyl group which the said polyol (b'1) has ( [NCO / OH equivalent ratio] is preferably performed in the range of 1.1 to 20.0, more preferably in the range of 1.1 to 13.0, and more preferably 1.1 to 5. More preferably, it is carried out in the range of 0, particularly preferably in the range of 1.5 to 3.0.

  In addition, as the polyisocyanate (b′2), an aromatic polyisocyanate is used, and an adhesive after bonding of a cured product (adhesive layer after curing) formed by curing the adhesive composition It is preferable for suppressing the shift and deformation of the layer over time.

  Examples of the aromatic polyisocyanate include diphenylmethane diisocyanate (MDI) such as 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, and 2,2′-diphenylmethane diisocyanate, polynuclear polyphenylene polymethyl polyisocyanate (polymeric). MDI), tolylene diisocyanate (TDI) such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene diisocyanate (NDI) such as 1,4-naphthalene diisocyanate, 1,5-naphthalene diisocyanate; 5-tetrahydronaphthalene diisocyanate; 1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate Phenylene diisocyanate (PDI), xylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI); tolidine diisocyanate (TODI), 2,4,6-trimethylphenyl-1,3-diisocyanate, 2,4,6 -Triisopropylphenyl-1,3-diisocyanate, chlorophenylene-2,4-diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy- Examples include 4,4′-diphenylene diisocyanate, 3,3′-dichloro-4,4′-biphenylene diisocyanate, and modified compounds thereof.

  Among the aromatic polyisocyanates, a cured product (adhesion after curing) having good reactivity with the polyol (b′1) and formed by curing the adhesive composition among the above-described aromatic polyisocyanates. Diphenylmethane diisocyanate such as 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, etc. (MDI), naphthalene diisocyanate (NDI) such as 2,4-tolylene diisocyanate, tolylene diisocyanate (TDI) such as 2,6-tolylene diisocyanate, 1,4-naphthalene diisocyanate, 1,5-naphthalene diisocyanate It is preferable to do.

  The reaction conditions (temperature, time, etc.) between the polyol (b′1) and the polyisocyanate (b′2) may be appropriately set in consideration of various conditions such as safety, quality, and cost, and are not particularly limited. For example, the reaction temperature is preferably in the range of 70 to 120 ° C., and the reaction time is preferably in the range of 30 minutes to 5 hours.

  When reacting the polyol (b′1) and the polyisocyanate (b′2), for example, a tertiary amine catalyst or an organometallic catalyst can be used as a catalyst as necessary. .

  The reaction may be performed in a solvent-free environment or in the presence of an organic solvent.

  Examples of the organic solvent include ester solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl butyl ketone, and cyclohexanone; and ether esters such as methyl cellosolve acetate and butyl cellosolve acetate. Solvents, aromatic hydrocarbon solvents such as toluene and xylene, amide solvents such as dimethylformamide and dimethylacetamide, and the like can be used alone or in combination of two or more. The organic solvent may be removed by an appropriate method such as heating under reduced pressure or drying at normal pressure during the production of the urethane resin (B ′) or after the production of the urethane resin (B ′).

  As the photopolymerizable adhesive layer of the present invention, a layer containing a photopolymerization initiator is used in order to promote the reactivity after irradiation with active energy rays and to obtain high bondability after curing.

  The polymerization initiator includes, for example, a photopolymerization initiator and a thermal polymerization initiator. By using a photopolymerization initiator whose reaction proceeds by light, a reaction at a low temperature and a good curing reaction are performed. Can be obtained. Thereby, it is possible to obtain high bondability without causing damage to the members to be laminated or causing distortion between the members without causing deformation of the members or causing cracks between the adhesive sheet and the members.

  As the light, an appropriate active energy ray such as an ultraviolet ray or visible light can be used, but an active energy ray having a wavelength of 300 nm to 420 nm is preferably used.

  The photopolymerization initiator is not particularly limited as long as it is activated by light, and examples thereof include a photoradical polymerization initiator, a photocationic polymerization initiator, and a photoanionic polymerization initiator. It is preferable to use an anionic polymerization initiator, and it is preferable to use a photocationic polymerization initiator because polymerization by dark reaction can be suitably adjusted.

  The photocationic polymerization initiator is not particularly limited as long as it can induce a ring-opening reaction of a cationically polymerizable functional group by light having a wavelength to be used, but cationic polymerization is performed by light having a wavelength of 300 to 370 nm. A compound that induces a ring-opening reaction of a functional group and is inactive in a wavelength region exceeding 370 nm is preferably used. Examples of such a compound include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfoniums. Examples include onium salts such as salts.

  Specific examples of such onium salts include, for example, optomer SP-150, optomer SP-170, optomer SP-171 (all manufactured by ADEKA), UVE-1014 (manufactured by General Electronics), OMNICAT250, and OMNICAT270 (all Also IGM Resin), IRGACURE290 (BASF), Sun-Aid SI-60L, Sun-Aid SI-80L, Sun-Aid SI-100L (all from Sanshin Chemical Industry Co., Ltd.), CPI-100P, CPI-101A, CPI-200K (Both manufactured by San Apro).

  In addition, the said cationic photopolymerization initiator may be used independently and may be used together 2 or more types. Furthermore, two-step curing may be performed using a plurality of photocationic polymerization initiators having different effective active wavelengths.

  The photocationic polymerization initiator may be used in combination with an anthracene-based, thioxanthone-based, or other sensitizer as necessary.

  The mixing ratio of the cationic photopolymerization initiator is preferably 0.001 to 30 parts by mass with respect to 100 parts by mass of the adhesive composition containing the urethane resin (B). It is preferably used in the range of 0.01 to 20 parts by mass, and more preferably in the range of 0.1 to 10 parts by mass. If the proportion of the photocationic polymerization initiator is too small, the curing required for the expression of high bondability is insufficient, and if it is too large, the curability is improved, but the curing proceeds rapidly after light irradiation, and the active energy is increased. It becomes difficult to join members that cannot transmit a line.

  As the photopolymerizable adhesive layer of the present invention, the photocurable resin (A), the thermoplastic resin (B), and the one containing other components as necessary in addition to the photopolymerization initiator. Can be used.

  As the photopolymerizable adhesive layer of the present invention, for example, when an adhesive sheet including a photopolymerizable adhesive layer is used, even if the adhesive sheet is wound around a roll or the like and stored, the adhesive layer is the end of the roll. In order to obtain an adhesive sheet that is further prevented from being extruded from the part and has excellent adhesive properties at room temperature, an adhesive resin having a weight average molecular weight in the range of 2000 to 2000000 can be used. The range of a preferable weight average molecular weight is 5000-1 million, and the more preferable range of a weight average molecular weight is 5000-800000.

  Examples of the adhesive resin include polyester, polyurethane, poly (meth) acrylate, and polyvinyl acetal. These adhesive resins may be homopolymers or copolymers. Moreover, these adhesive resins may be used independently and 2 or more types may be used together.

  As the adhesive resin, it is preferable that the adhesive resin has an adhesive property at room temperature because the adhesiveness when the photopolymerizable adhesive layer is laminated on the adherend is improved. In order to impart the tackiness of the adhesive resin, the glass transition temperature of the adhesive resin is preferably in the range of -30 to 20 ° C, more preferably in the range of -25 to 10 ° C. . By being a glass transition temperature within the above range, it is possible to impart tackiness to the curable adhesive sheet composition, to impart a high elastic modulus, and to improve the bonding strength of the adhesive sheet.

  The glass transition temperature of the adhesive resin is, for example, a test piece between parallel disks that are measuring units of the test machine using a dynamic viscoelasticity tester (manufactured by Rheometrics, trade name: Ares 2KSTD). , The storage elastic modulus (G ′) and loss elastic modulus (G ″) at a frequency of 1.0 Hz are measured, and the loss elastic modulus (G ″) is divided by the storage elastic modulus (G ′) ( G ″ / G ′) can be calculated as the temperature at which the loss tangent (tan δ) can be maximized.

  Since the adhesive resin may be crosslinked, a functional group capable of reacting with a functional group contained in the crosslinking agent or the photopolymerizable adhesive layer may be introduced. Examples of the functional group include a hydroxyl group, a carboxyl group, an epoxy group, an amino group, and the like, but it is preferable to select the functional group in a time range that does not hinder the polymerization of the photopolymerizable adhesive layer.

  The adhesive resin is preferably used in the range of 0.1 to 100 parts by mass, and in the range of 1 to 50 parts by mass with respect to 100 parts by mass of the photopolymerizable adhesive layer. It is preferable to use in the range of 5 to 30 parts by mass. Even if it is a case where the adhesive sheet is wound around a roll or the like and stored, the adhesive layer is a roll without reducing the bondability after curing by setting the adhesive resin within the above range. Can be further prevented from being pushed out from the end portion, and an adhesive sheet excellent in stickability at room temperature can be obtained.

  As the photopolymerizable adhesive layer, one containing other additives can be used as necessary.

  Examples of the additive include aluminum hydroxide, aluminum oxide, aluminum nitride, magnesium hydroxide, magnesium oxide, mica, talc, boron nitride, glass flake and other fillers, silane coupling agents, phosphoric acid additives, and acrylate additives. An agent, a tackifier, etc. can be used. In particular, it is preferable to use a silane coupling agent rich in reactivity with glass because an adhesive sheet excellent in adhesiveness to a member made of glass or the like can be obtained, and can react with the photopolymerizable adhesive layer. It is more preferable to use a photocurable silane coupling agent.

  In addition to the above-described additives, the additives are within the range not impairing the effects of the present invention, for example, softeners, stabilizers, adhesion promoters, leveling agents, antifoaming agents, plasticizers, tackifying resins, fibers Those containing additives such as antioxidants, hydrolysis inhibitors, thickeners, colorants such as pigments, fillers and the like can be used.

  As the photopolymerizable adhesive layer, it is preferable to use one previously formed into an arbitrary shape such as a sheet as described above, and has the adhesive layer on both surfaces of a sheet-like substrate. Alternatively, it may be a so-called substrate-less adhesive sheet that does not have the sheet-like substrate and is constituted by the adhesive layer. As said adhesive sheet, what is comprised by the single adhesive layer may be used, and what laminated | stacked the same or different 2 or more adhesive layers can also be used.

As a manufacturing method of the said adhesive sheet, it can manufacture, for example by apply | coating the said adhesive composition on both surfaces of a base material, and drying as needed and forming an adhesive bond layer.

  In the case of producing the adhesive sheet in which two or more adhesive layers having the same or different compositions are laminated, for example, the adhesive composition 1 is applied to both surfaces of the sheet-like substrate, and dried as necessary. Can be produced by forming the adhesive layer 1, applying another adhesive composition 2 to the surface of the adhesive layer 1, and drying the adhesive layer 2 as necessary to form the adhesive layer 2.

  As the adhesive sheet, for example, the adhesive composition 1 is applied to the surface of a release sheet, and dried as necessary to form the adhesive layer 1, and another adhesive is applied to the surface of the adhesive layer 1. It can be produced by applying the composition 2 and drying it as necessary to form the adhesive layer 2.

  As the adhesive sheet, it is preferable to use a composition containing a solvent in addition to the polymerizable compound and the polymerization initiator as the composition in order to improve the working efficiency when the sheet is formed into the sheet shape or the like.

  Examples of the solvent include ester solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; ketone solvents such as acetone, methyl ketyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone; aromatics such as toluene and xylene. Hydrocarbon solvents and the like can be used.

  The adhesive sheet of this invention can be manufactured by mixing the said polymeric compound and arbitrary components, such as the said polymerization initiator and a solvent. When producing the adhesive sheet (X) by mixing the components described above, a dissolver, butterfly mixer, BDM biaxial mixer, planetary mixer, etc. can be used as necessary, and the dissolver and butterfly mixer should be used. In the case of using the conductive filler, it is preferable to use a planetary mixer in order to improve the dispersibility thereof.

The polymerization initiator is preferably used before the adhesive sheet is cured or before the adhesive sheet is formed into a sheet or the like.
The adhesive sheet is prepared by, for example, applying a composition containing the polymerizable compound and an arbitrary component such as the polymerization initiator or a solvent, and then applying the composition to a release liner, for example, and drying the composition. Can be manufactured.
The drying is preferably performed at a temperature of about 40 ° C. to 120 ° C., more preferably about 50 ° C. to 90 ° C., in order to suppress the progress of the curing reaction of the sheet-like adhesive sheet. Moreover, since the foaming of the sheet | seat surface by rapid volatilization, such as a solvent, can be suppressed, it is preferable.

  The adhesive sheet may be sandwiched between the release liners before being used.

  Examples of the release liner include paper such as kraft paper, glassine paper, and high-quality paper; resin films such as polyethylene, polypropylene (OPP, CPP), and polyethylene terephthalate; laminated paper in which the paper and the resin film are laminated, and the paper A material obtained by applying a release treatment such as a silicone-based resin to one or both surfaces of a material subjected to a sealing treatment with clay or polyvinyl alcohol can be used.

  The temperature at the time of storing the adhesive sheet is preferably −10 ° C. or more, more preferably 5 ° C. or more, and 23 ° C. or more reduces water absorption of the adhesive sheet due to condensation, It is more preferable because it can suppress a decrease in curability of the adhesive sheet.

The cured product (cured adhesive layer) formed by curing the adhesive sheet is 1.0 × 10 ⁴ Pa when the storage elastic modulus (E ′ ₄₀ ) at 40 ° C. is measured at a frequency of 1.0 Hz. In addition, when the storage elastic modulus (E ′ ₆₀ ) at 60 ° C. is 1.0 × 10 ⁴ Pa or more when measured at a frequency of 1.0 Hz, it is at a level that does not cause peeling over time. It is preferable when it has adhesiveness.

The cured product (cured adhesive layer) formed by curing the adhesive sheet is 1.0 × 10 ⁵ Pa when the storage elastic modulus (E ′ ₂₅ ) at 25 ° C. is measured at a frequency of 1.0 Hz. Preferably, it is 1.0 × 10 ⁶ Pa or more, and more preferably 1.0 × 10 ⁷ Pa or more. By setting it as the above range, it is possible to suppress time-dependent displacement and deformation of the adhesive layer after joining.

  The dynamic viscoelasticity of the cured product (adhesive layer after curing) formed by curing the adhesive sheet was measured using a dynamic viscoelasticity measuring device (trade name: RSA-II, manufactured by Rheometrics). It is the value. For the measurement, a cured product (adhesive layer after curing) having a thickness of 100 μm formed by curing the adhesive sheet was prepared, and this was used as a shape of test piece type 5 of JIS K 7127 using a dumbbell cutter. The one punched out was used.

Examples of the image display device include a mobile terminal (PDA) such as a personal computer, a mobile phone, a smartphone, and a tablet PC, a game machine, a television (TV), a car navigation system, a touch panel, and a pen tablet, LCD, PDP or EL, organic EL, The structural member of the flat-type image display apparatus using the image display panel carrying micro LED, quantum dot (QD), etc. can be mentioned. Examples of the structural member include an image display panel, a circuit board, a rear cover, a bezel, a frame, and a chassis. Since the adhesive sheet of the present invention can firmly join members after curing, it can also be used for joining members constituting a large-sized image display device used for industrial applications and advertising applications.
It is preferable in terms of wearing ability.

Examples and comparative examples will be specifically described below.
<Preparation of thermoplastic resin (X-1)>
In a reaction vessel, 50 parts by mass of an aliphatic polycarbonate polyol having a number average molecular weight of 2000 obtained by reacting 1,5-pentanediol, 1,6-hexanediol and dialkyl carbonate, 1,6-hexanediol and adipic acid 30 parts by mass of a polyester polyol having a number average molecular weight of 4500 obtained by the reaction was mixed, and dehydrated by heating to 100 ° C. under reduced pressure conditions until the water content became 0.05% by mass.

  Next, after the mixture of the aliphatic polycarbonate polyol and the polyester polyol cooled to 70 ° C. and 14.5 parts by mass of dicyclohexylmethane-4,4′-diisocyanate were heated to 100 ° C., By reacting for 3 hours, a thermoplastic resin (X-1) made of polyurethane was obtained. In addition, the said thermoplastic resin (X-1) has an isocyanate group as a polymeric functional group.

<Preparation of thermoplastic resin (X-2)>
In a reaction vessel, 40 parts by mass of an aliphatic polycarbonate polyol having a number average molecular weight of 2000 obtained by reacting 1,5-pentanediol, 1,6-hexanediol and dialkyl carbonate, 1,6-hexanediol and adipic acid It mixed with 40 mass parts of polyester polyols of the number average molecular weight 4500 obtained by making it react, and it dehydrated until it became 0.05 mass% by heating to 100 degreeC on pressure reduction conditions.

  Next, after mixing the mixture of the aliphatic polycarbonate polyol and the polyester polyol cooled to 70 ° C. and 13.7 parts by mass of dicyclohexylmethane-4,4′-diisocyanate, the temperature was raised to 100 ° C., By reacting for 3 hours, a thermoplastic resin (X-2) was obtained. In addition, the said thermoplastic resin (X-2) has an isocyanate group as a polymeric functional group.

<Preparation of adhesive sheet (Y-1)>
100 parts by mass of the thermoplastic resin (X-1), 43 parts by mass of CEL-2021P (manufactured by Daicel Corp., alicyclic epoxy resin), CPI-100P (manufactured by San Apro Corp., sulfonium salt type, solid concentration 50%) 11 .4 parts by mass was mixed and stirred, and methyl ethyl ketone was added to adjust the nonvolatile content to 75% by mass to obtain an adhesive composition (y-1).

  Next, the bonding resin paint (y-1) is applied to the surface of a release liner (one surface of a polyethylene terephthalate film having a thickness of 50 μm is peeled off with a silicone compound) using a rod-shaped metal applicator. The coating was performed so that the thickness after drying was 100 μm.

Further, the coated product was put into a drier at 85 ° C. for 5 minutes and dried, and a release liner (one side of a 38 μm thick polyethylene terephthalate film was peeled off with a silicone compound on one side of the dried coated product). The adhesive sheet (Y-1) having a thickness of 100 μm was obtained.
The gel fraction before curing of the adhesive sheet (Y-1) was 0.5%.

In addition, as a measuring method of the gel fraction before hardening of the said adhesive sheet (Y-1), after cut | disconnecting the adhesive sheet (Y-1) to the magnitude | size of 40 mm x 50 mm, only the single sided release liner is removed. A test piece was obtained. After measuring the mass of the test piece, it was immersed in toluene adjusted to 23 ° C. for 24 hours.
After the immersion, the test piece was taken out, and the mass of what was dried in a dryer at 105 ° C. for 1 hour was measured. Based on the said mass and the following formula | equation, the gel fraction of the adhesive bond layer before active energy ray irradiation was computed.

  Gel fraction (% by mass) of adhesive layer before irradiation with active energy ray = {(mass of adhesive layer of adhesive sheet remaining without being dissolved in toluene) / (adhesive layer of adhesive sheet before immersion in toluene) Mass)} × 100

The mass of the adhesive layer of the adhesive sheet (Y-1) before the immersion indicates a value obtained by subtracting the mass of the release liner used for the production from the mass of the test piece. Further, the mass of the remaining adhesive layer refers to a value obtained by subtracting the mass of the release liner from the mass after the residue is dried.
Moreover, the loss tangent (tan δ ₂₃ ) at 23 ° C. of the adhesive sheet (Y-1) was 0.5.

The loss tangent (tan δ ₂₃ ) of the adhesive sheet (Y-1) at 23 ° C. is 8 mm in diameter after peeling the release liner laminated on both sides of the adhesive sheet and laminating the adhesive layer to a thickness of 1 mm. A test piece was cut into a circle having a size of. Using a dynamic viscoelasticity tester (manufactured by Rheometrics, trade name: Ares 2KSTD), a test piece is sandwiched between parallel disks, which are measurement parts of the tester, at a temperature of 23 ° C. and a frequency of 1 Hz. The storage elastic modulus (G ′) and the loss elastic modulus (G ″) are measured, and the loss tangent (tan δ) is a value obtained by dividing the loss elastic modulus (G ″) by the storage elastic modulus (G ′) (G ″ / G ′).

<Preparation of adhesive sheet (Y-2)>
In the same manner as the preparation of the adhesive sheet (Y-1), except that 100 parts by mass of the thermoplastic resin (X-1) is used instead of 100 parts by mass of the thermoplastic resin (X-1), adhesion is performed. The sheet (Y-2) was adjusted.
In addition, the gel fraction before hardening of the said adhesive sheet (Y-2) was 0.2%.
Further, the loss tangent (tan δ ₃₃ ) of the adhesive sheet (Y-2) at 23 ° C. was 0.3.

  As adherends used in this example and comparative example, an aluminum plate having a smooth surface with a width of 15 mm, a length of 70 mm, and a thickness of 0.3 mm is degreased, and two pieces are attached to the end of the upper surface of the aluminum plate. The spacers were arranged in parallel with a gap of 12 mm to produce bonded aluminum with a spacer, and this was used as the adherend (I). The spacer was made of a PET film and an adhesive sheet, and was prepared so that the total thickness of the PET film and the adhesive sheet was 80 μm. Further, an epoxy glass plate (Shin-Kobe Electric Co., Ltd./KEL-GEF) having a width of 15 mm, a length of 70 mm and a thickness of 1.0 mm was used as the adherend (II). The adherend (I) and the adherend (II) are light opaque materials.

Example 1
Step [1-1]: A test sample was prepared by cutting the adhesive sheet (Y-1) into a size of width 10 mm × length 10 mm. The 38 μm-thick release liner of the test sample was removed, and press-bonded for 10 seconds at a pressure of 0.05 MPa under a temperature environment of 23 ° C. so as to be between the two adherends (I), Pasted together.

Step [2-1]: Next, the patch was left in a temperature environment of 23 ° C. for 30 minutes. Thereafter, the surface layer on the other surface of the test sample was irradiated with ultraviolet rays having an intensity of about 100 mW / cm ² for 10 seconds using an electrodeless lamp (fusion lamp H bulb).

  Step [3-1]: The patch after the ultraviolet irradiation was left in a temperature environment of 23 ° C. for 20 minutes, then the release liner on the other side of the test sample was removed, and the release liner was removed. The surface and the adherend (II) were bonded together by press-bonding at a pressure of 0.05 MPa for 2 seconds in a temperature environment of 23 ° C.

  Step [5-1]: The patch was press-molded for 10 minutes under a pressure of 0.2 MPa using a hot press heated to 80 ° C.

  Step [4-1]: The laminate after press-bonding was left to stand at 80 ° C. for 1 hour, and left to stand in a 23 ° C. environment for 30 minutes to cool to obtain an evaluation sample (Z-1).

  In the step [2-1], the gel fraction of the adhesive sheet (Y-1) after irradiation with ultraviolet light was 8.5%.

  In the step [4-1], the gel fraction of the adhesive sheet (Y-1) after being allowed to cool for 30 minutes in the 23 ° C. environment was 71.5%.

  When the said evaluation sample (Z-1) was confirmed visually, the said adherend (I) and the adherend (II) did not show changes, such as generation | occurrence | production of bending, a dent, and discoloration.

(Example 2)
Instead of the adhesive sheet (Y-1), the process [1-2], the process [2-2], and the process [2] are performed in the same manner as in Example 1 except that the adhesive sheet (Y-2) is used. 3-2], step [5-2], and step [4-2] were performed to obtain an evaluation sample (Z-2).

  In the step [2-2], the gel fraction of the adhesive sheet (Y-1) after being irradiated with ultraviolet light was 6.1%.

  In the step [4-2], the gel fraction of the adhesive sheet (Y-1) after being allowed to cool for 30 minutes in the 23 ° C. environment was 68.9%.

  When the said evaluation sample (Z-2) was confirmed visually, the said adherend (I) and the adherend (II) did not show changes, such as generation | occurrence | production of bending, a dent, and discoloration.

(Example 3)
Between step [1-1] and step [2-1], step [5′-3]: the patch was pressurized at 0.2 MPa using a hot press heated to 80 ° C. The process [1-3], the process [2-3], the process [3-3], and the process [5-3] are performed in the same manner as in Example 1 except that a process of press molding for 1 minute is added. And Step [4-3] were performed to obtain an evaluation sample (Z-3).

  In the step [2-3], the gel fraction of the adhesive sheet (Y-1) after irradiation with ultraviolet light was 9.0%.

  In the step [4-3], the gel fraction of the adhesive sheet (Y-1) after being allowed to cool for 30 minutes in the 23 ° C. environment was 74.1%.

(Comparative Example 1)
In the step [2-1], the steps [1-1 ′] and [2-1 ′] are performed in the same manner as in Example 1 except that ultraviolet rays having an intensity of about 100 mW / cm ² are irradiated for 1 minute. Step [3-1 ′], Step [5-1 ′] and Step [4-1 ′] were performed to obtain an evaluation sample (Z′-1).

  In the step [2-1 '], the gel fraction of the adhesive sheet (Y-1) after irradiation with ultraviolet light was 46.1%.

  In the step [4-1 ′], the gel fraction of the adhesive sheet (Y-1) after being allowed to cool for 30 minutes in the 23 ° C. environment was 77.8%.

  When the said evaluation sample (Z'-1) was confirmed visually, generation | occurrence | production of a partial bending and a dent was seen in the said to-be-adhered body (I).

(Comparative Example 2)
In the step [2-1], the step [1-2 ′] and the step [2-2 ′] are performed in the same manner as in Example 1 except that ultraviolet rays having an intensity of about 90 mW / cm ² are irradiated for 1 second. Step [3-2 ′], Step [5-2 ′] and Step [4-2 ′] were performed to obtain an evaluation sample (Z′-2).

  In the step [2-2 '], the gel fraction of the adhesive sheet (Y-1) after irradiation with ultraviolet light was 0.3%.

In the step [4-2 '], the gel fraction of the adhesive sheet (Y-1) after being allowed to cool for 30 minutes in the 23 ° C. environment was 10.8%.

  When the said evaluation sample (Z'-2) was confirmed visually, the said adherend (I) and the adherend (II) did not see changes, such as generation | occurrence | production of bending, a dent, and discoloration.

(Comparative Example 3)
In the step [2-1], an ultraviolet ray having an intensity of about 90 mW / cm ^{2 was} irradiated for 1 second, and in the step [4-1], the heating and leaving of the laminate after press-bonding was changed from 80 ° C. to 180 ° C. The process [1-3 ′], process [2-3 ′], process [3-3 ′], process [5-3 ′], process [4-3] are the same as in Example 1 except that '] To obtain an evaluation sample (Z'-3).

  In the step [2-3 '], the gel fraction of the adhesive sheet (Y-1) after irradiation with ultraviolet light was 0.3%.

  In the step [4-3 ′], the gel fraction of the adhesive sheet (Y-1) after being allowed to cool for 30 minutes in the 23 ° C. environment was 84.1%.

  When the evaluation sample (Z′-2) was visually confirmed, the adherend (II) was deteriorated and turned yellow.

  Moreover, the following evaluation was performed about the evaluation sample obtained by the said Example and comparative example.

[Evaluation of thickness change (flexibility)]
Measure the total thickness of the evaluation samples obtained in the examples and comparative examples, and calculate the thickness of the adhesive sheet after lamination by subtracting the thickness of the adherend (I) and adherend (II) from there. And evaluated according to the following criteria.

(Double-circle): The thickness of the adhesive sheet after the said lamination | stacking was 80 micrometers.
A: The thickness of the adhesive sheet after the lamination was greater than 80 μm and 90 μm or less.
(Triangle | delta): The thickness of the adhesive sheet after the said lamination | stacking was thicker than 90 micrometers, and was 95 micrometers or less.
(Triangle | delta): The thickness of the adhesive sheet after the said lamination | stacking was thicker than 95 micrometers, and was 100 micrometers or less (no change).

[Evaluation of shear adhesive strength (bondability)]
The end portions of the adherend (I) and the adherend (II) of the evaluation samples obtained in the examples and comparative examples are each chucked and 180 ° C. using a tensile tester in a temperature environment of 23 ° C. The evaluation sample shear adhesive force was determined by performing a tensile test in the direction of the tension at a tensile speed of 10 mm / min.

Claims (16)

A method for producing a laminate in which two or more adherends having a surface that does not transmit active energy rays are laminated via an adhesive sheet, the first surface of the adhesive layer of the adhesive sheet, the first adherend, [1], the active energy ray is irradiated to the other surface of the adhesive layer of the adhesive sheet before or after the step [1] to cure the adhesive layer. Step [2] for improving the rate by 0.01% or more, Step [3] for bonding the second surface of the adhesive layer of the adhesive sheet and the second adherend by pressure-sensitive adhesion, and the adhesion The manufacturing method of the laminated body which contains the process [4] which further hardens the hardening rate of an agent layer 3% or more from the hardening rate of the said process [2] in this order. The state in which the adhesive sheet is crushed between the step [1] and the step [2], between the step [1] and the step [3], and at least one of the step [3] and the step [4]. The manufacturing method of the laminated body of Claim 1 which has process [5] which forms. The manufacturing method of the laminated body of Claim 1 or 2 whose pressure which the said process [1] bonds is 0.1-3000 KPa. Active energy rays of the step [2], the intensity of 0.1~1000mW / cm ^2, the laminate according to claim 1 for irradiating this 0.1 to 60 seconds Production method. In the said process [5], the manufacturing method of the laminated body as described in any one of Claims 2-4 which crushes the said adhesive sheet by applying the pressure of 1-600 KPa at the temperature of 30-100 degreeC. In the said process [4], the manufacturing method of the laminated body as described in any one of Claims 1-5 hardened by curing the said adhesive sheet at the temperature of 20-100 degreeC for 10 minutes-7 days. The manufacturing method of the laminated body as described in any one of Claims 2-6 by which the said process [5] is performed within 60 minutes after finishing the said process [2]. The manufacturing method of the laminated body as described in any one of Claims 1-7 by which the said process [4] is performed within 60 minutes after finishing the said process [2]. The method for producing a laminate according to any one of claims 1 to 8, wherein a loss tangent (tan δ ₂₃ ) of the adhesive layer of the adhesive sheet before curing at 23 ° C is less than 3.0. The manufacturing method of the laminated body as described in any one of Claims 1-9 in which the adhesive bond layer of the said adhesive sheet contains a photocurable resin (A), a thermoplastic resin (B), and a photoinitiator. The manufacturing method of the laminated body as described in any one of Claims 1-10 in which the said photopolymerizable compound (A) and a thermoplastic resin (B) have polymerizable functional groups other than a polymerizable unsaturated double bond. The method for producing a laminate according to any one of claims 1 to 11, wherein the photocurable resin (A) has a photocationically polymerizable and / or photoanion polymerizable functional group. The said thermoplastic resin (B) is a urethane resin, The manufacturing method of the laminated body as described in any one of Claims 1-12. The method for producing a laminate according to any one of claims 1 to 13, wherein the photopolymerization initiator is a photocationic polymerization initiator. The manufacturing method of the laminated body as described in any one of Claims 1-14 in which the adhesive bond layer of the said adhesive sheet has melting | fusing point in the range of 30 to 120 degreeC. An image display device manufactured using the manufacturing method according to claim 1.