JP5395585B2 - Post-curing tape and joining member joining method - Google Patents

Description

The present invention relates to a post-curing tape that can be cured in a short time by induction heating to obtain a high adhesive force.

The epoxy resin adhesive is an adhesive that is cured by a reaction between an epoxy compound and a curing agent by heating, and takes, for example, a one-component or two-component liquid form or a film form. Epoxy resin adhesives are widely used in various fields because their cured products have excellent adhesion, heat resistance, chemical resistance, electrical properties, and the like.

In recent years, a film-like adhesive made of an epoxy-acrylic resin composition has been proposed as a film-like epoxy resin adhesive.
The epoxy-acrylic resin composition is, for example, a composition containing, as main components, an epoxy compound, a curing agent, an acrylate compound that can be polymerized by active energy ray irradiation, and a photopolymerization initiator. After being coated, the film is formed into an adhesive film by irradiation with active energy rays. A film-like adhesive composed of an epoxy-acrylic resin composition has a structure in which a curable component such as an epoxy compound or a curing agent is incorporated into a film having adhesiveness, and is bonded using the adhesiveness. After temporarily fixing to the surface of the member, a strong adhesive force can be exhibited by curing the curable component by heating.

As a film adhesive made of an epoxy-acrylic resin composition, for example, Patent Document 1 discloses a. An epoxy compound, b. A predetermined particulate epoxy curing agent, c. A compound having a predetermined glass transition point and having at least one ultraviolet-polymerizable acroyl group or metaacroyl group in the molecule; d. A compound having at least one functional group capable of reacting with an ultraviolet-polymerizable acroyl group or methacryloyl group and an epoxy compound or an epoxy curing agent, e. A film-like adhesive having a predetermined thickness obtained by ultraviolet polymerization of an epoxy-acrylic resin composition containing a photoinitiator is disclosed.
However, the film-like adhesive described in Patent Document 1 is heated and cured by leaving it in an oven at 150 ° C. for 30 minutes, and it takes a long time to cure, so that it is still insufficient from the viewpoint of productivity.

Japanese Patent Laid-Open No. 8-165659

An object of this invention is to provide the post-curing tape which can be hardened | cured in a short time by induction heating, and can obtain high adhesive force.

The present invention is a post-curing tape having an adhesive layer on at least one surface of a heat generating sheet that generates heat by high-frequency induction heating, the adhesive layer comprising a (meth) acrylic polymer, an epoxy resin, and an epoxy A post-curing tape containing a heat latent curing agent.
The present invention is described in detail below.

The inventors of the present invention provide a post-curing tape having a pressure-sensitive adhesive layer containing a (meth) acrylic polymer, an epoxy resin, and an epoxy thermal latent curing agent. The heat generated by the high-frequency induction heating of the pressure-sensitive adhesive layer. By forming on at least one surface of the sheet, it was found that it was cured in a short time and high adhesive strength was obtained, and the present invention was completed.

The post-curing tape of the present invention has a heat generating sheet that generates heat by high-frequency induction heating (hereinafter also simply referred to as a heat generating sheet). By having the heat generating sheet, the obtained post-curing tape is induction-heated by a high-frequency induction heating device, so that it can be cured in a short time, for example, about 3 to 60 seconds, and can exhibit high adhesive force. .
In this specification, induction heating refers to heating based on eddy current generated by a magnetic field. Further, in this specification, “heat generation due to high-frequency induction heating” means that an alternating magnetic field is generated by passing a high-frequency alternating current through the coil, and is conducted by a magnetic flux line passing through a conductive substance placed in the alternating magnetic field. An eddy current is generated in a conductive material, and the conductive material generates heat by Joule heat based on the generated eddy current.

The heating sheet is not particularly limited as long as it is a sheet that generates heat by high-frequency induction heating, that is, a sheet that generates heat by Joule heat based on eddy current generated when placed in an AC magnetic field, and has, for example, conductivity. A metal sheet etc. are mentioned.
The conductive metal sheet is not particularly limited, and examples thereof include a sheet made of aluminum, iron, stainless steel, copper, brass, or the like. Especially, since it is easy to handle, the sheet | seat which consists of aluminum and stainless steel is preferable.

When the said heat generating sheet has the adhesive layer mentioned later on both surfaces of a heat generating sheet, it is preferable to have several pores which occupy 30 to 70% of the area of the whole heat generating sheet. By having such a plurality of pores, the resulting post-curing tape has a pressure-sensitive adhesive on both sides integrated in the pores to improve the adhesive cohesive force, and between the heat generating sheet and the pressure-sensitive adhesive layer. Peeling is suppressed and the adhesion is improved.
When the area occupied by the plurality of pores is less than 30% of the total area of the heat generating sheet, the resulting post-cured tape has an effect of improving the adhesive cohesion by integrating the pressure-sensitive adhesives on both sides of the pores. The adhesive strength of the post-curing tape may decrease. When the area occupied by the plurality of pores exceeds 70% of the total area of the heat generating sheet, the heat generation amount of the heat generating sheet may be reduced, and the resulting post-cured tape may be insufficiently cured to reduce the strength. There is.
More preferably, the heat generating sheet has a plurality of pores that occupy 40 to 60% of the entire area of the heat generating sheet.

The plurality of pores have a preferable lower limit of the average pore diameter of 0.1 mm and a preferable upper limit of 3 mm. When the average pore diameter is less than 0.1 mm, in the resulting post-cured tape, the effect of improving the adhesive cohesive force due to the integration of the double-sided pressure-sensitive adhesive in the pores decreases, and the adhesive strength of the post-cured tape May decrease. When the average pore diameter exceeds 3 mm, the heat generated from the heat generating sheet may not be transmitted to the pore adhesive, and the resulting post-cured tape may be insufficiently cured to lower the strength. The plurality of pores has a more preferable lower limit of the average pore diameter of 0.3 mm and a more preferable upper limit of 2 mm.

Although the thickness of the said heat_generation | fever sheet | seat is not specifically limited, A preferable minimum is 10 micrometers and a preferable upper limit is 200 micrometers. If the thickness is less than 10 μm, the heat generation sheet may be weak and difficult to handle. In addition, if the thickness is less than 10 μm, the amount of heat generated may be reduced, and the resulting post-cured tape may be insufficiently cured to reduce the strength. If the thickness exceeds 200 μm, the heat generation sheet may be too stiff and the followability of the resulting post-cured tape may be reduced. The minimum with more preferable thickness of the said heat_generation | fever sheet | seat is 20 micrometers, and a more preferable upper limit is 100 micrometers.

The heat generating sheet is preferably preliminarily treated with a primer in order to improve adhesion with the pressure-sensitive adhesive layer. The primer is not particularly limited, and examples thereof include Poliment NK-350, Poliment NK-380 (both manufactured by Nippon Shokubai Co., Ltd.) and the like.

The post-curing tape of the present invention has an adhesive layer on at least one surface of the heat generating sheet. The post-curing tape of the present invention may have an adhesive layer on one side of the heat generating sheet, or may have an adhesive layer on both sides of the heat generating sheet.
The pressure-sensitive adhesive layer contains a (meth) acrylic polymer, an epoxy resin, and an epoxy thermal latent curing agent. Such an adhesive layer can be cured by induction heating after being bonded to the joining member. In this specification, after the adhesive layer having adhesiveness and having a structure in which a curable component such as an epoxy resin is taken in is bonded to the joining member using the adhesiveness. When the curable component is cured by heating and develops a strong adhesive force, it is called “post-curing”.

The said (meth) acrylic-type polymer will not be specifically limited if adhesiveness can be provided to the post-curing tape obtained, For example, the polymer obtained by polymerizing (meth) acrylic acid and / or (meth) acrylic acid ester, etc. Is mentioned.
The polymerization method is not particularly limited, and examples thereof include bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. The polymerization reaction in the polymerization method is not particularly limited, and examples thereof include a free radical polymerization reaction, a living radical polymerization reaction, and a living anion polymerization reaction. The polymerization reaction can be initiated by applying energy such as heat, ultraviolet rays, and electron beams. Moreover, in the said polymerization reaction, you may use a reaction initiator at the time of making it superpose | polymerize.

The (meth) acrylic acid ester is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, cyclohexyl (Meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isomyristyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) Acrylate, benzyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) a Relate, compounds having one (meth) acryloyl groups in one molecule, such as polypropylene glycol mono (meth) acrylate. These (meth) acrylic acid esters may be used alone or in combination of two or more. Above all, it has excellent compatibility with epoxy resin and improves the adhesive strength of the cured product of the resulting post-cured tape, so ethyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, polypropylene Glycol mono (meth) acrylate is preferred.

The epoxy resin is not particularly limited, and examples of commercially available products include novolak epoxy resins such as bisphenol F-type epoxy resins, bisphenol A-type epoxy resins, and novolak epoxy oligomers, brominated epoxy resins, flexible epoxy resins (and above). , All manufactured by Toto Kasei Co., Ltd.), Epicoat basic solid type, Epicoat bis F solid type (all of which are manufactured by Japan Epoxy Resin Co., Ltd.), EHPE alicyclic solid epoxy resin, glycidyl methacrylate homopolymer, glycidyl methacrylate copolymer ( As mentioned above, all are Daicel Chemical Industries Ltd.) etc.

Moreover, as a commercial item of the said epoxy resin, for example, jER828, jER834, jER806, jER807 (all are the Japan Epoxy Resin company make), EX-611, EX-612, EX-614, EX-614B, EX- 622, EX-512, EX-521, EX-411, EX-421, EX-313, EX-314, EX-321, EX-201, EX-211, EX-212, EX-252, EX-810, EX-811, EX-850, EX-851, EX-821, EX-830, EX-832, EX-841, EX-861, EX-911, EX-941, EX-920, EX-721, EX- 221, EM-150, EM-101, EM-103 (all of which are manufactured by Nagase ChemteX Corporation, Denacole Series) ), YD-115, YD-115G, YD-115CA, YD-118T, YD-127 (all are manufactured by Tohto Kasei Co., Ltd.), 40E, 100E, 200E, 400E, 70P, 200P, 400P, 1500NP, 1600, Examples thereof include liquid epoxy resins such as 80MF, 100MF, 4000, 3002, 1500 (all of which are manufactured by Kyoeisha Chemical Co., Ltd., Epolite series).

Further, commercially available products of the above epoxy resins include, for example, Celoxide 2021, Celoxide 2080, Celoxide 3000, Epolide GT300, Epolide GT400, Epolide D-100ET, Epolide D-100OT, Epolide D-100DT, Epolide D-100ST, Epolide D- Examples thereof include liquid epoxy resins such as 200HD, Epolide D-200E, Epolide D-204P, Epolide D-210P, Epolide PB3600, Epolide PB4700 (all of which are manufactured by Daicel Chemical Industries, Ltd., alicyclic epoxy compounds).

Although the compounding quantity of the said epoxy resin in the said adhesive layer is not specifically limited, The preferable minimum with respect to 100 weight part of said (meth) acrylic-type polymers is 5 weight part, and a preferable upper limit is 100 weight part. When the amount of the epoxy resin is less than 5 parts by weight, the adhesive strength after curing of the resulting post-cured tape may be reduced. When the amount of the epoxy resin exceeds 100 parts by weight, the cured product of the resulting post-curing tape becomes too hard and the stress dispersibility is lowered. For example, when a joining member such as glass is joined, stress is applied to the joined portion. If added, cracks or cracks may occur. As for the compounding quantity of the said epoxy resin in the said adhesive layer, the more preferable minimum with respect to 100 weight part of the said (meth) acrylic-type polymers is 10 weight part, and a more preferable upper limit is 80 weight part.

The epoxy thermal latent curing agent is not particularly limited, and examples thereof include dicyandiamide and derivatives thereof, boron trifluoride-amine complex, imidazole derivatives, and organic acid hydrazides.
Examples of commercially available epoxy thermal latent curing agents include Amicure PN-23, PN-31, PN-H, PN-40, PN-50, MY-24, VDH, UDH, AH-123, and AH-203. (All are manufactured by Ajinomoto Fine Techno Co., Ltd.), Fuji Cure FXR-1020, FXR-103, FXR-1081, FXR-1211, 7000 (all are manufactured by Fuji Kasei Kogyo Co., Ltd.), Curesol 2E4MZ-CN, 2PZ-CN 2MZ-A, C11Z-A, 2E4MZ-A, 2MA-OK, 2PZ-OK, 2PHZ-PW (all of which are manufactured by Shikoku Kasei Kogyo Co., Ltd.).

Moreover, since it is excellent in storage stability as the said epoxy thermal latent hardener, it is preferable to use the above-mentioned hardener or microencapsulated latent hardener which contains amines inside.
Examples of commercially available microencapsulated latent curing agents include NOVACURE HX-3721, HX-3722, HX-3748, HX-3741, HX-3742, HX-3088, and HX-3613 (all of which are Asahi Kasei Corporation). Materials) and the like.

Furthermore, it is also preferable to use a ketoprofen base generator as the epoxy thermal latent curing agent because the curing rate increases.
In this specification, the ketoprofen base generator refers to a salt of α- (2-benzoyl) phenylpropionic acid and an amine represented by the following formula (1).
_{H 2 N - [(CH 2} ) n -N-] m - (CH 2) n -NH 2 (1)
In formula (1), m represents 0 or 1, and n represents an integer of 4 to 8.

Since the ketoprofen base generator is a salt of α- (2-benzoyl) phenylpropionic acid and an amine represented by the above formula (1), it is decomposed by induction heating, and the above formula (1) To produce the amine represented.
The generated amine represented by the formula (1) functions as a curing agent for the epoxy resin. Therefore, after bonding the post-curing tape to the bonding member, the amine represented by the above formula (1) is generated by induction heating to generate the amine represented by the above formula (1), and the epoxy resin Reacts and cures, and can be firmly bonded.

Further, since the ketoprofen base generator is a viscous liquid rather than particles, it is more uniformly and finely dispersed in the pressure-sensitive adhesive layer than a conventionally known curing agent having a shape such as particles. That is, it can be more uniformly and finely dispersed in the epoxy resin. Therefore, when the amine represented by the formula (1) is generated from the ketoprofen base generator by induction heating, the curing reaction between the generated amine represented by the formula (1) and the epoxy resin is easy and Since it progresses uniformly as a whole, the obtained post-curing tape can be cured in a short time by induction heating.

In said formula (1), when m exceeds 1, the storage stability of the obtained post-curing tape may fall.
Moreover, in said formula (1), when n is less than 4, the dispersibility in the said adhesive layer of a ketoprofen type base generator may fall, and the sclerosis | hardenability of the obtained hardening tape may fall. When n exceeds 8 in the above formula (1), the resulting post-cured tape may be slow to cure or bleed.

Specific examples of the ketoprofen base generator include 1,4-diaminobutane 2α- (2-benzoyl) phenylpropionate and 1,6-diaminohexane 2α- (2-benzoyl) phenylpropion. Acid salt, bis (6-aminohexyl) amine tri-α- (2-benzoyl) phenylpropionate, and the like.

Although the compounding quantity of the said epoxy thermal latent hardener in the said adhesive layer is not specifically limited, The preferable minimum with respect to 100 weight part of said epoxy resins is 1 weight part, and a preferable upper limit is 80 weight part. When the blending amount of the epoxy thermal latent curing agent is less than 1 part by weight, the curing time of the obtained post-curing tape becomes long, and sufficient adhesive strength may not be obtained by short-time induction heating. When the amount of the epoxy thermal latent curing agent exceeds 80 parts by weight, the resulting post-curing tape may be poorly cured or the adhesive strength may be reduced. The compounding amount of the epoxy thermal latent curing agent in the pressure-sensitive adhesive layer is such that a more preferable lower limit with respect to 100 parts by weight of the epoxy resin is 3 parts by weight, and a more preferable upper limit is 50 parts by weight.

The said adhesive layer may contain a filler within the range which does not inhibit the effect of this invention.
The filler is not particularly limited, and examples thereof include organic substances such as polymethyl methacrylate, polyethylene, and polystyrene, and inorganic substances such as calcium carbonate and magnesium oxide.

The filler preferably has an average particle diameter of 5 μm or more and does not have a portion that reacts with the epoxy resin.
By containing such a filler, when stress is applied to the joint of the resulting post-curing tape, voids are generated around the filler to disperse and absorb the stress, reducing stress concentration at the joint interface. Thus, the adhesive force can be improved. If the average particle size of the filler is less than 5 μm, the effect of improving the adhesive force of the post-curing tape may not be obtained. The upper limit of the average particle diameter of the filler is not particularly limited. However, when the average particle diameter is larger than the thickness of the pressure-sensitive adhesive layer, the adhesive is exposed from the pressure-sensitive adhesive layer and the adhesiveness is lowered. It is preferably smaller than the thickness of the agent layer.

When the pressure-sensitive adhesive layer contains the filler, the amount of the filler in the pressure-sensitive adhesive layer is not particularly limited, but the total of the (meth) acrylic polymer, the epoxy resin, and the epoxy thermal latent curing agent is 100. A preferred lower limit relative to parts by weight is 1 part by weight, and a preferred upper limit is 30 parts by weight. When the blending amount of the filler is less than 1 part by weight, stress dispersion in the cured product of the obtained post-curing tape is insufficient, and the adhesive force may not be sufficiently improved. When the blending amount of the filler exceeds 30 parts by weight, the obtained post-curing tape may lack an effective adhesive component at the bonding interface, and the adhesive force may decrease. The blending amount of the filler in the pressure-sensitive adhesive layer is 3 parts by weight, more preferably 20 parts by weight, with respect to a total of 100 parts by weight of the (meth) acrylic polymer, the epoxy resin, and the epoxy thermal latent curing agent. Parts by weight.

The pressure-sensitive adhesive layer further contains a rosin resin, a modified rosin resin, a terpene resin, a terpene phenol resin, an aromatic modified terpene resin, a C5 or C9 petroleum oil, a coumarone resin, and the like. Also good.
In particular, when the joining member to which the obtained post-curing tape is bonded is made of polyolefin, it is preferable that the pressure-sensitive adhesive layer contains a rosin-based resin or a petroleum-based resin because the adhesive strength of the cured product can be increased.

The pressure-sensitive adhesive layer may further contain a silane coupling agent.
By containing the said silane coupling agent, the interface adhesive force of the hardened | cured material of the post-curing tape obtained can be improved.

The method for producing the post-curing tape of the present invention is not particularly limited. For example, the (meth) acrylic polymer, the epoxy resin, the epoxy thermal latent curing agent, and other components as necessary, a solvent A method of laminating and mixing using the above, coating and drying, then laminating the exothermic sheet, or directly applying to the exothermic sheet and drying, the monomer constituting the (meth) acrylic polymer, the above By mixing the epoxy resin, the above epoxy thermal latent curing agent, and other components such as a photo radical polymerization initiator, if necessary, without using a solvent, cast into a sheet, and then irradiate with ultraviolet rays Examples thereof include a method of polymerizing a monomer constituting the (meth) acrylic polymer and laminating it on the heat generating sheet. Among these, the latter method is preferred because it is not necessary to use a solvent, and therefore the possibility that the curing reaction proceeds in a process involving heating such as drying is low, and a thick film post-curing tape can be produced.

The use of the post-curing tape of the present invention is not particularly limited, and for example, the joining members can be joined using the post-curing tape of the present invention.
The method for joining the joining members is not particularly limited. After obtaining the assembly by pasting the post-curing tape of the present invention and the joining member, the obtained assembly is subjected to a high frequency induction heating apparatus for 3 to 60 seconds. The method of induction heating by is preferable. If the induction heating time is less than 3 seconds, the post-curing tape may be insufficiently cured and the adhesive force may be insufficient. When the induction heating time exceeds 60 seconds, the assembly is heated too much, and the adhesive force may be reduced due to deterioration of the bonding member and / or the pressure-sensitive adhesive. As the high-frequency induction heating device, for example, EASY WELDER KIT1000, EASY WELDER KIT2000 (both manufactured by Cyhit) are used.
A joining member joining method using the post-curing tape of the present invention, wherein the post-curing tape of the present invention and the joining member are bonded together to obtain an assembly, and the assembly is formed by high-frequency induction heating. A method for joining a joining member having a step of heating for ˜60 seconds is also one aspect of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the post-curing tape which can be hardened | cured in a short time by induction heating, and can acquire high adhesive force can be provided.

Examples of the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

(Synthesis example 1 of ketoprofen base generator)
(Synthesis of 1,4-diaminobutane 2α- (2-benzoyl) phenylpropionate)
80 g of α- (2-benzoyl) phenylpropionic acid and 12.6 g of 1,4-diaminobutane were mixed in ethanol and reacted by stirring at room temperature for 24 hours. Then, after removing ethanol using an evaporator, the obtained crude product was reprecipitated using ethanol / hexane to obtain 1,4-diaminobutane-2-α- (2-benzoyl) phenylpropionate. .

(Synthesis example 2 of ketoprofen base generator)
(Synthesis of 1,6-diaminohexane 2α- (2-benzoyl) phenylpropionate)
1,6-diaminohexane-2-α- (2-benzoyl) is the same as Synthesis Example 1 except that 80 g of α- (2-benzoyl) phenylpropionic acid and 16.6 g of 1,6-diaminohexane were used. Phenylpropionate was obtained.

(Synthesis example 3 of ketoprofen base generator)
(Synthesis of bis (6-aminohexyl) amine tri-α- (2-benzoyl) phenylpropionate)
In the same manner as in Synthesis Example 1 except that 80 g of α- (2-benzoyl) phenylpropionic acid and 20.5 g of bis (6-aminohexyl) amine were used, bis (6-aminohexyl) amine triα- ( 2-Benzoyl) phenylpropionate was obtained.

(Synthesis example 4 of ketoprofen base generator)
(Synthesis of ethylenediamine 2-α- (2-benzoyl) phenylpropionate)
Ethylenediamine 2-α- (2-benzoyl) phenylpropionate was obtained in the same manner as in Synthesis Example 1 except that 80 g of α- (2-benzoyl) phenylpropionic acid and 8.6 g of ethylenediamine were used.

(Examples 1-28, Comparative Examples 1-6)
(Preparation of post-curing tape)
According to the composition of Tables 1, 2, and 3, an acrylic monomer that becomes a (meth) acrylic polymer by photopolymerization, an epoxy resin (“JER828” manufactured by Japan Epoxy Resin Co., Ltd.), an epoxy thermal latent curing agent, a radical photopolymerization initiator ( “Irgacure 819” manufactured by Ciba Geigy Co., Ltd.) and other blending components were uniformly mixed to obtain a coating solution. Nitrogen was blown into the obtained coating liquid to drive out oxygen, and then each of the release processing surfaces of the two 38 μm silicon release processing PET films were in contact with the coating liquid so that the thickness became 0.2 mm. An acrylic monomer was polymerized by irradiating UV light of 2 mW for 3 minutes with a fluorescent lamp having a main wavelength of 420 nm with the coating liquid interposed therebetween, to obtain an adhesive tape having no substrate having a thickness of 0.2 mm.

The silicon release treatment PET film on one side of the obtained pressure-sensitive adhesive tape is peeled off, and this is applied to both sides of the heat generation sheet having the materials and thicknesses shown in Tables 1, 2, and 3, and the exposed pressure-sensitive adhesive layer surface is the heat generation sheet. The post-cured tape was obtained by bonding so as to face each other. In Comparative Examples 1, 4, 5, and 6, no heat generating sheet was used, and the adhesive tapes were laminated.
A primer (Nippon Shokubai Co., Ltd., Polyment NK-380) was previously applied to both sides of the heat generating sheet.

(Examples 29 to 41)
The formulation was changed according to Table 4, and circular pores having the average pore diameter (mm) shown in Table 4 were distributed almost uniformly, and the number of pores (number / cm ² ) shown in Table 4 and A post-cured tape was obtained in the same manner as in Examples 1 to 28 and Comparative Examples 1 to 6 except that a heat generating sheet having a pore area ratio (%) in the entire heat generating sheet was used.

(Evaluation)
The post-cured tapes obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in Tables 1, 2, 3, and 4.

(1) Evaluation of initial shear adhesive strength After curing, the cured tape was cut to have a planar shape of 20 mm × 20 mm. After cutting, the silicon release-treated PET film of the cured tape is peeled off on a glass plate (20 mm x 50 mm x 7 mm) from which dust and oil on the surface have been removed by alcohol washing so that the exposed adhesive layer surface faces the glass plate Then, a post-cured tape was bonded, and a glass plate was bonded in the same manner on the opposite surface to obtain a test piece. After the obtained test piece was cured at 23 ° C. for 20 minutes, a shear tensile test was performed using a tensile tester at 23 ° C. and a crosshead speed of 50 mm / min. The maximum breaking strength was evaluated as a shear adhesive strength.

(2) Evaluation of post-curing shear adhesive strength Test specimens were prepared in the same manner as in (1) above, and after induction heating with EASY WELDER KIT2000 (manufactured by Cyhit Corp.) for the times shown in Tables 1, 2, 3, and 4, After curing at 23 ° C. for 1 day, the shear adhesive strength was evaluated in the same manner as (1) above. In Comparative Examples 4 to 6, heating was performed in an oven at 150 ° C. for the time shown in Table 3 instead of induction heating.

ADVANTAGE OF THE INVENTION According to this invention, the post-curing tape which can be hardened | cured in a short time by induction heating, and can acquire high adhesive force can be provided.

Claims (4)

A post-curing tape having an adhesive layer on at least one surface of a heat generating sheet that generates heat by high frequency induction heating,
The said adhesive layer contains a (meth) acrylic-type polymer, an epoxy resin, and an epoxy thermal latent hardener, The postcure tape characterized by the above-mentioned. It has an adhesive layer on both sides of the heat generating sheet that generates heat by high frequency induction heating,
The heat generating sheet that generates heat by high frequency induction heating has a plurality of pores that occupy 30 to 70% of the entire area of the heat generating sheet,
The post-curing tape according to claim 1, wherein the pores have an average pore diameter of 0.1 to 3 mm. The post-curing tape according to claim 1 or 2, wherein the epoxy thermal latent curing agent is a ketoprofen base generator. A joining method for a joining member using the post-curing tape according to claim 1, 2 or 3,
Bonding the post-curing tape and the joining member to obtain an assembly;
And heating the assembly by high-frequency induction heating for 3 to 60 seconds.