JP6041178B2 - Adhesive tape, article, motor and method for producing article - Google Patents

Description

  The present invention relates to an adhesive tape having a configuration in which a volume is expanded by applying a stimulus such as heating.

  Since the adhesive tape can be suitably used when fixing two or more adherends, it is widely used in the production scenes of various products such as automobiles and electric devices.

  On the other hand, as the use range of the adhesive tape further expands, the adhesive tape is required to be used when, for example, the other adherend is fixed in the gap of one adherend. Specifically, as a motor mounted on a hybrid vehicle or the like, a motor having a configuration in which a gap is generally provided at a predetermined position of a core (rotor core) and a magnet is embedded in the gap is known. Yes. The use of an adhesive tape is being studied when fixing the magnet in the gap of the core portion.

  The adhesive tape that can be used in the above application is formed on the first surface of the base material having a first surface and a second surface on the opposite side of the first surface and having a communication port, for example. A first adhesive layer containing a thermosetting thermally expandable epoxy adhesive, and the thermosetting thermally expandable epoxy adhesive passes through the communication port of the substrate when heated, and A thermosetting thermally expandable adhesive sheet that forms a second adhesive layer on the second surface is known (see, for example, Patent Document 1).

  Since it is considered that the first adhesive layer constituting the thermosetting thermally expandable adhesive sheet is previously attached to an adherend such as a magnet, it has a good adhesive force even after the thermal expansion. It can be maintained.

  However, fine irregularities may be formed on the surface of the second adhesive layer due to the thermal expansion. In some cases, the second adhesive layer having the surface on which the fine irregularities are formed cannot exhibit a sufficient adhesive force to the adherend.

JP 2013-023559 A

  The problem to be solved by the present invention is to provide an adhesive tape that can maintain excellent adhesive strength even after the expansion, among adhesive tapes that can expand by stimulation such as heating.

  The inventors of the present invention provide an adhesive tape having an adhesive layer (B) on one side of the adhesive layer (A) directly or via another layer, and the adhesive tape is placed in an environment at 130 ° C. Expansion rate in the thickness direction of the adhesive layer (A) after being left for a time [thickness of the adhesive layer (A) after being left / thickness of the adhesive layer (A) before being left] × 100 is 200% or more, and the expansion rate in the thickness direction of the adhesive layer (B) [the thickness of the adhesive layer (B) after being left / the adhesive layer (B) before being left) It has been found that the above problem can be solved by an adhesive tape characterized in that the [thickness] × 100 is 120% or less.

  Since the adhesive tape of the present invention can maintain an excellent adhesive strength even after being expanded, it can be used for fixing two or more adherends, and in addition, the other adherend can be placed in the gap of one adherend. It can be suitably used for applications such as fixing the adherend and filling the voids of the adherend with the adhesive tape.

  In addition, the adhesive tape of the present invention can follow the fine irregularities due to the expansion even when the adherend has minute irregularities and gaps, and as a result, exhibits excellent adhesive strength. Can do. In addition, since the adhesive tape of the present invention can expand or fix other adherends at predetermined positions in the voids of the adherends by expanding, the production efficiency of final products including motors can be increased. Can be improved.

  Moreover, the adhesive tape of the present invention is less likely to cause variations in the adhesive strength even when the expansion coefficient is appropriately changed.

It is a conceptual diagram which shows the measuring method of the shearing adhesive force of an adhesive tape.

  The adhesive tape of the present invention is an adhesive tape having an adhesive layer (B) on one side of the adhesive layer (A) directly or via another layer, and the adhesive tape is placed in an environment of 130 ° C. Expansion coefficient in the thickness direction of the adhesive layer (A) after being left for 1 hour [thickness of the adhesive layer (A) after being left / thickness of the adhesive layer (A) before being left] X100 is 200% or more, and the expansion coefficient in the thickness direction of the adhesive layer (B) [the thickness of the adhesive layer (B) after being left / the adhesive layer (B) before being left) The thickness] × 100 is 120% or less.

  The adhesive layer (A) constituting the adhesive tape is a layer that can be expanded by applying a stimulus such as heat or light.

  As the adhesive layer (A), when the adhesive tape is left in an environment of 130 ° C. for 1 hour, the expansion rate in the thickness direction of the adhesive layer (A) [the adhesive layer after being left ( Thickness of A) / thickness of adhesive layer (A) before leaving] × 100 is 200% or more.

  The expansion coefficient is preferably 250% or more, and more preferably 250% to 1000%. If the adhesive tape has the adhesive layer (A) having the expansion coefficient, for example, even when the height (thickness) of the gap of one adherend is large, the other adherend is placed in the gap. The body can be suitably fixed, or the space can be filled with the adhesive tape.

  In addition, the expansion coefficient indicates that the adhesive layer (A) after being left with respect to the thickness of the adhesive layer (A) before being left standing when the adhesive tape is left in an environment of 130 ° C. for 1 hour. It refers to the ratio of thickness ((thickness of the adhesive layer (A ′) formed by expansion). Specifically, the expansion coefficient refers to a value calculated by the following method.

  The thickness of the adhesive layer (A) constituting the adhesive tape before being left for 1 hour in a 130 ° C. environment (before expansion) is measured in a 23 ° C. environment.

  The adhesive tape is left in an environment of 130 ° C. for 1 hour.

  The adhesive tape after being left standing is taken out in a 23 ° C. environment, and the thickness of the adhesive layer (A ′) formed by immediately expanding the adhesive layer (A) is measured.

The expansion coefficient is calculated based on the measurement result and the following formula.
[The thickness of the adhesive layer (A) constituting the adhesive tape after standing] [The thickness of the adhesive layer (A ') formed by swelling] / of the adhesive layer (A) constituting the adhesive tape before standing Thickness] × 100

In order to maintain excellent adhesion between the adhesive layer (A) after the expansion and the adherend, the adhesive layer (A) is previously attached to the adherend before the expansion. preferable.
preferable.

  The thickness of the adhesive layer (A) constituting the adhesive tape is preferably 1 μm or more, more preferably in the range of 10 μm to 250 μm, still more preferably in the range of 20 μm to 150 μm, and 30 μm. The range of ˜70 μm is particularly preferable in order to obtain a further excellent adhesive strength.

  On the other hand, the thickness of the adhesive layer (A ′) formed by expanding the adhesive layer (A) is preferably in the range of 20 μm to 2500 μm, and in the range of 40 μm to 1500 μm. It is preferable for obtaining even better adhesive strength. The adhesive layer (A ′) preferably has a porous structure.

  Moreover, as said adhesive tape, it is preferable to use what the thickness of the said adhesive bond layer (A) is 10% or more with respect to the total thickness of the said adhesive tape, and what is 30% or more It is more preferable to use it because, for example, it is easy to fix the other adherend in the gap of one adherend or to fill the gap with the adhesive tape.

  As the adhesive layer (A), as described above, a layer that can be expanded by applying a stimulus such as heat or light can be used. Specifically, a layer containing various resins and an expansion agent is used. be able to.

  The adhesive layer (A) can be formed, for example, by applying an adhesive composition (a) containing the resin and an expanding agent to a release liner or the like and drying it.

  As the adhesive composition (a) that can be used for forming the adhesive layer (A), as described above, a composition containing a resin, an expansion agent, and a solvent as required can be used.

  As the resin, an epoxy resin, a urethane resin, a silicone resin, a phenol resin, a urea resin, a fluororesin, an acrylonitrile resin, an acrylic resin, a styrene resin, a vinyl resin such as a butadiene resin, or the like is used alone or in combination of two or more. be able to.

  Among these, it is preferable to use a thermosetting resin as the resin, and it is preferable to use an epoxy resin, which has excellent heat resistance after expansion, and the expanded adhesive layer (A ′) is remarkably over time. It is more preferable for obtaining an adhesive tape capable of preventing shrinkage.

  Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, hindered-in type epoxy resin, biphenyl type epoxy resin, alicyclic epoxy resin, triphenylmethane type epoxy resin, and phenol novolac. Type epoxy resin, cresol novolak type epoxy resin, naphthol novolak type epoxy resin, dicyclopentadiene / phenol epoxy resin, alicyclic amine epoxy resin, aliphatic amine epoxy resin, and CTBN modification (carboxy-terminated butadiene nitrile modification) Halogen-modified epoxy resins or the like can be used alone or in combination of two or more, and the use of a cresol novolac type epoxy resin can be caused by the stimulation. Zhang easy and preferable because it can hold the adhesive strength is excellent even after expansion.

  It is preferable that 10 mass%-99 mass% of thermosetting resins, such as the said epoxy resin, are contained with respect to the said adhesive bond layer (A) whole.

  Moreover, it is preferable to use what contains a swelling agent as said adhesive composition (a), when forming the adhesive bond layer (A) which can be expanded by the said irritation | stimulation.

  The expansion agent is preferably one that can form a porous structure as the adhesive layer (A ′) after expansion, such as ammonium carbonate, ammonium hydrogen carbonate, ammonium nitrite, ammonium borohydride, azide, and the like. Inorganic compounds, fluorinated alkanes such as trichloromonofluoromethane, azo compounds such as azobisisobutyronitrile, hydrazine compounds such as paratoluenesulfonyl hydrazide, semicarbazide compounds such as p-toluenesulfonyl semicarbazide, 5-morpholyl-1,2 Triazole compounds such as 3,3,4-thiatriazole and N-nitroso compounds such as N, N′-dinitrosotephthalamide can be used.

  Further, as the expansion agent, for example, an expandable capsule such as a thermally expandable capsule in which a hydrocarbon solvent is microencapsulated can be used. As the expansion agent, it is preferable to use a material capable of generating gas and expanding at a temperature around the softening point of the resin.

  As the expansion agent, use of a thermally expandable capsule in which a hydrocarbon solvent is microencapsulated among the above is used, for example, to inhibit the curing of the epoxy resin, or to form an adhesive layer (A ) Is preferable for preventing deterioration and the like.

  As the thermally expandable capsule, it is preferable to use a capsule having a volume after expansion (volume expansion coefficient) of 8 to 60 times with respect to the volume of the capsule before expansion.

  Examples of commercially available thermal expandable capsules include EXPANSEL (manufactured by Nippon Philite Co., Ltd.), Matsumoto Microsphere (manufactured by Matsumoto Yushi Seiyaku Co., Ltd.), and Microsphere (manufactured by Kureha Co., Ltd.).

  The amount of the expansion agent used, preferably the amount of the thermally expandable capsule, is preferably in the range of 0.3% by mass to 40% by mass with respect to the total amount of the adhesive layer (A). More preferably, it is in the range of 0.0 mass% to 30 mass%, and the range of 3.0 mass% to 20 mass% is expanded to a sufficient volume for filling the voids of the adherend. It is preferable for obtaining an adhesive tape that can be maintained and can maintain an even better adhesive strength.

  As said adhesive composition (a), what contains a hardening | curing agent, a hardening accelerator, etc. other than what was mentioned above as needed can be used.

  Examples of the curing agent include bisphenol A, bisphenol F, bisphenol AD, hydroquinone, resorcin, methyl resorcin, biphenol, tetramethylbiphenol, dihydroxynaphthalene, dihydroxydiphenyl ether, phenol novolac resin, bisphenol A novolac resin, dicyclopentadiene phenol resin. Various polyphenol resins such as terpene phenol resin, naphthol novolac resin, biphenyl phenol resin, polyhydric phenol resins obtained by condensation reaction of various phenols with various aldehydes such as hydroxybenzaldehyde, crotonaldehyde, glyoxal, And a modified phenol obtained by polycondensation of heavy oil or pitch, phenol and formaldehyde compounds Various phenolic resins such as resins, acid anhydrides such as methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, methylnadic acid, amines such as diethylenetriamine, isophoronediamine, diaminodiphenylmethane, diaminodiphenylsulfone, dicyandiamide, etc. Can be used.

  Examples of the curing accelerator include imidazoles such as 2-methylimidazole, 2-methyl-4-ethylimidazole, and 2-phenylimidazole; 1,8-diazabicyclo [5.4.0] undecene-7, triethylenediamine, benzyl Tertiary amines such as dimethylamine; organic phosphines such as tributylphosphine and triphenylphosphine can be used alone or in combination of two or more.

  Moreover, as said adhesive tape, what has an adhesive bond layer (B) on the single side | surface of the said adhesive bond layer (A) is used. The adhesive layer (B) may be directly laminated on one surface side of the adhesive layer (A), or may be laminated via another layer such as a so-called base material. .

  As the adhesive layer (B), when the adhesive tape is allowed to stand in an environment of 130 ° C. for 1 hour, the expansion rate in the thickness direction of the adhesive layer (B) [the adhesive layer after being left ( B) thickness / thickness of adhesive layer (B) before standing] × 100 is 120% or less.

  The expansion ratio of the adhesive layer (B) is preferably 115% or less, and more preferably 100% to 115%.

  If it is an adhesive tape which has the adhesive layer (B) of the said expansion coefficient, even after the said adhesive layer (A) expand | swells, the outstanding adhesive strength with respect to a to-be-adhered body can be maintained.

  It should be noted that the expansion rate of the adhesive layer (B) is such that, when the adhesive tape is left in an environment of 130 ° C. for 1 hour, the thickness of the adhesive layer (B) before being left is not changed. It refers to the ratio of the thickness of the adhesive layer.

  Note that the expansion rate of the adhesive layer (B) is the ratio of the adhesive layer (B) after being left with respect to the thickness of the adhesive layer (B) before being left when the adhesive tape is left in an environment of 130 ° C. for 1 hour. It refers to the ratio of the thickness of the adhesive layer (B ′). Specifically, the expansion coefficient indicates a value calculated by the following method.

  The thickness of the adhesive layer (B) constituting the adhesive tape before being left in a 130 ° C. environment for 1 hour (before expansion) is measured in a 23 ° C. environment.

  The adhesive tape is left in an environment of 130 ° C. for 1 hour.

  The adhesive tape after the standing is taken out in a 23 ° C. environment, and the thickness of the adhesive layer (B ′) corresponding to the adhesive layer (B) is immediately measured.

The expansion coefficient is calculated based on the measurement result and the following formula.
[The thickness of the adhesive layer (B ′) constituting the adhesive tape after being left / the thickness of the adhesive layer (B) constituting the adhesive tape before being left] × 100

  The thickness of the adhesive layer (B) is preferably in the range of 5 μm to 150 μm, and more preferably in the range of 10 μm to 100 μm, in order to express even better adhesive strength.

  The thickness of the adhesive layer (B ′) after being left for 1 hour in the environment of 130 ° C. varies within the above expansion coefficient range as compared with the thickness of the adhesive layer (B) before being left standing. May be. The thickness of the adhesive layer (B ′) is preferably in the range of 1 μm to 150 μm, and more preferably in the range of 5 μm to 100 μm, in order to express even better adhesive strength.

  Moreover, as said adhesive bond layer (B), the layer which has adhesiveness or adhesiveness is mentioned, For example, a thermosetting adhesive bond layer, a pressure sensitive adhesive layer, etc. are mentioned.

  The said adhesive bond layer (B) can be formed using the adhesive composition (b) which can form the layer which has adhesiveness or adhesiveness, for example.

  As said adhesive composition (b), what contains adhesive resin and the hardening | curing agent as needed, for example can be used. In addition, since it is preferable that the adhesive bond layer (B) formed using the said adhesive composition (b) has a low expansion coefficient as above-mentioned, it can be used when forming the said adhesive bond layer (A). It is preferable that the swelling agent illustrated as a thing does not contain substantially.

  As an adhesive resin that can be used for the adhesive composition (b), a conventionally known resin can be selected and used. For example, a thermosetting resin, a pressure-sensitive adhesive resin, or the like can be used.

  Especially, as said adhesive resin, when improving the production efficiency of the adhesive tape of this invention, it illustrates as adhesive resin (a) containing resin which can be used for formation of the said adhesive bond layer (A), for example The same ones can be used.

  In addition, as the adhesive resin, even after the adhesive layer (A) is expanded, it can maintain excellent adhesive strength to the adherend, and particularly has excellent adhesive strength regardless of the influence of heat. In obtaining an adhesive tape having a maintainable adhesive layer (B), a thermosetting resin is preferably used, and an epoxy resin is more preferably used.

  As the epoxy resin, it is possible to use the same resin as exemplified for the adhesive composition (a), even after the adhesive layer (A) is expanded. It is preferable for obtaining an adhesive tape having an adhesive layer (B) that can maintain excellent adhesive strength with respect to the adherend and can maintain excellent adhesive strength regardless of the influence of heat.

  As said adhesive composition (b), what contains a hardening | curing agent, a hardening accelerator, etc. other than what was mentioned above as needed can be used. As said hardening | curing agent and hardening accelerator, the thing similar to what was illustrated as a hardening | curing agent and hardening accelerator which can be used for the said adhesive composition (a) can be used.

  As the adhesive composition (b), in addition to those described above, a coupling agent, a tackifier, an antifoaming agent, a pigment, an antioxidant, a core-shell type reinforcing agent, a thixotropic agent, You may use what contains a heat conductive filler, an insulating filler, etc.

  The adhesive tape of the present invention, for example, the step [1] of forming the adhesive layer (A) by applying the adhesive composition (a) to a release liner and drying it, separately from the step [1], Step [2] of forming the adhesive layer (B) by applying the adhesive composition (b) to a release liner and drying, etc., and the adhesive layer on one side of the adhesive layer (A) It can manufacture by passing (B) and passing through the process [3] of crimping them.

  A part of the adhesive layer (A) may be cured in the process of producing the adhesive tape, but it is preferable that the adhesive layer (A) is not substantially expanded or cured. A part of the adhesive layer (B) may also be cured in the process of producing the adhesive tape, but it is preferable that the adhesive layer (B) is not substantially cured.

  In addition, as the adhesive tape of the present invention, if necessary, a tape having a resin film layer or a metal layer (Z) between the adhesive layer (A) and the adhesive layer (B) is used. Can do. Since such an adhesive tape has good rigidity, it is excellent in sticking workability.

  Examples of the layer (Z) include a resin film layer formed using a plastic film such as a polyester film, a polyethylene film, a polypropylene film, a polyvinyl chloride film, a polyimide film, and a polyethylene terephthalate film, and a metal such as aluminum and copper. Layer.

  As the layer (Z), it is preferable to use a layer having a thickness of 1 μm to 200 μm, and it is more preferable to use a layer having a thickness of 12 μm to 50 μm.

  For the adhesive tape having the layer (Z), for example, the step [1] of forming the adhesive layer (A) by applying the adhesive composition (a) to a release liner and drying it [1], the step [1] Separately, the step (2) of forming the adhesive layer (B) by applying the adhesive (b) to a release liner and drying or the like, the layer (Z) on one side of the layer (A) And the step [5] of transferring the adhesive layer (B) onto the surface composed of the layer (Z) and press-bonding them to the surface comprising the layer (Z).

  The adhesive tape of this invention can be expanded by giving irritation | stimulation to the said adhesive bond layer (A) or the said adhesive tape whole. Examples of the stimulus include heat and light as described above. Examples of the method for giving the stimulus include methods such as heating and light irradiation, and it is preferable to employ a heating method.

  The heating temperature is preferably a temperature corresponding to, for example, a temperature at which the expansion agent expands (expansion start temperature), specifically, preferably 80 ° C to 300 ° C, and preferably 100 ° C to 200 ° C. Preferably there is.

  The adhesive tape of the present invention preferably expands in the thickness direction after the stimulus such as heating is given. On the other hand, it is preferable that the adhesive tape of the present invention does not substantially expand in the flow direction or the width direction after the stimulation such as heating is given.

  As a method for fixing two or more adherends using the adhesive tape of the present invention, for example, one adherend and the adhesive layer (A) constituting the adhesive tape are pasted in advance. The adhesive layer (B) and another adherend are brought into contact with each other by placing the product obtained in a predetermined position and causing the adhesive layer (A) to stimulate and expand at least the adhesive layer (A). The method of making it adhere | attach is mentioned. In that case, the said stimulus may be given to the said adhesive bond layer (A) which comprises the said adhesive tape, and may be given to the said adhesive tape whole.

  The adhesive tape of the present invention includes, for example, a part (c1-1) constituting the adherend (C1) and another part (c1-2) constituting the adherend (C1) or another adherend ( It can be suitably used for the manufacture of an article having a configuration in which C2) is bonded.

  In the article, the adhesive layer (A) constituting the adhesive tape and the part (c1-1) constituting the adherend (C1) are bonded in advance [1], and at least the adhesive By stimulating and expanding the layer (A), the adhesive layer (B) constituting the adhesive tape and the part (c1-2) constituting the adherend (C1) or the adherend (C2) ) And the process [2] for bonding.

  Examples of the article include a motor mounted on a hybrid vehicle or the like. Specifically, in the motor, an adhesive layer (A) that constitutes the adhesive tape and a part of a part such as a magnet are preliminarily bonded to a gap included in a core member that constitutes the motor. After placing, it can be produced by stimulating and expanding at least the adhesive layer (A).

  The adhesive tape can be used for the purpose of filling the voids of the adherend. For example, after the adhesive tape is placed in the voids of the adherend, at least the adhesive layer (A Can be used to form a structure in which two or more locations in the gap are bonded by the adhesive tape.

(Preparation Example 1)
<Preparation of adhesive composition (a-1)>
Epiklone N-680 (a cresol novolac type epoxy resin solution manufactured by DIC Corporation, epoxy equivalent 215 g / eq, 75% by mass of non-volatile content) 21.4 parts by mass, “JER YL-7862” (Mitsubishi Chemical Corporation bisphenol) After mixing 48 parts by mass of an A-type epoxy resin solution, epoxy equivalent 3748 g / eq, nonvolatile content 50% by mass), 30.6 parts by mass of methyl ethyl ketone is mixed to obtain an epoxy resin composition having a nonvolatile content of 40% by mass (1 )

  Next, with respect to 100 parts by mass of the epoxy resin composition (1), Expandel 051-40 (manufactured by Nippon Philite Co., Ltd., thermally expandable microcapsule, initial particle size 12 μm, expansion start temperature 110 ° C., Mixing 3.2 parts by mass with a volume expansion coefficient at 130 ° C. of 7 times and 0.4 parts by mass of Curazole 2MAOK-PW (manufactured by Shikoku Kasei Co., Ltd., imidazole curing accelerator) as a curing agent, 10 minutes By stirring, the adhesive composition (a-1) was obtained.

(Preparation Example 2)
<Preparation of adhesive composition (a-2)>
The amount of use of the expand cell 051-40 (manufactured by Nippon Philite Co., Ltd., thermally expandable microcapsule, initial particle diameter 12 μm, expansion start temperature 110 ° C., volume expansion coefficient at 130 ° C. is 7 times) is 3.2 mass. An adhesive composition (a-2) was obtained in the same manner as in Preparation Example 1, except that the amount was changed from 5.4 parts to 6.4 parts by weight.

(Preparation Example 3)
<Preparation of adhesive composition (a-3)>
The amount of use of the expand cell 051-40 (manufactured by Nippon Philite Co., Ltd., thermally expandable microcapsule, initial particle diameter 12 μm, expansion start temperature 110 ° C., volume expansion coefficient at 130 ° C. is 7 times) is 3.2 mass. An adhesive composition (a-3) was obtained in the same manner as in Preparation Example 1, except that the amount was changed from 9.5 parts to 9.6 parts by weight.

(Preparation Example 4)
<Preparation of adhesive composition (a-4)>
Instead of 3.2 parts by mass of the above Expandel 051-40 (manufactured by Nippon Philite Co., Ltd., thermally expandable microcapsule, initial particle diameter 12 μm, expansion start temperature 110 ° C., volume expansion coefficient at 130 ° C. is 7 times) Other than using 1.6 parts by mass of EXPANSEL 920-120 (manufactured by Nippon Philite Co., Ltd., thermally expandable microcapsule, initial particle size 12 μm, expansion start temperature 127 ° C., volume expansion coefficient at 130 ° C. is 4 times). Obtained the adhesive composition (a-4) in the same manner as in Preparation Example 1.

(Preparation Example 5)
<Preparation of adhesive composition (a-5)>
Epicron N-680 (a cresol novolac type epoxy resin solution manufactured by DIC Corporation, epoxy equivalent 215 g / eq, 75% by mass of nonvolatile content) 37.3 parts by mass, “JER YL-7862” (Mitsubishi Chemical Corporation bisphenol A type epoxy resin solution, epoxy equivalent 3748 g / eq, non-volatile content 50% by mass) 24 parts by mass, and then mixed with 38.7 parts by mass of methyl ethyl ketone, whereby an epoxy resin composition (non-volatile content 40% by mass) ( 2) was obtained.

  Next, with respect to 100 parts by mass of the epoxy resin composition (2), Expandel 051-40 (manufactured by Nippon Philite Co., Ltd., thermally expandable microcapsule, initial particle diameter 12 μm, expansion start temperature 110 ° C., Mixing 3.2 parts by mass with a volume expansion coefficient at 130 ° C. of 7 times and 0.4 parts by mass of Curazole 2MAOK-PW (manufactured by Shikoku Kasei Co., Ltd., imidazole curing accelerator) as a curing agent, 10 minutes By stirring, an adhesive composition (a-5) was obtained.

(Preparation Example 6)
<Preparation of adhesive composition (b-1)>
Epiklone N-680 (cresol novolac type epoxy resin solution manufactured by DIC Corporation, epoxy equivalent 215 g / eq, non-volatile content 75 mass%) 21.4 parts by mass, “YL-7862” (Mitsubishi Chemical Corporation bisphenol A Type epoxy resin solution, epoxy equivalent 3748 g / eq, non-volatile content 50% by mass) 48 parts by mass, and then mixing 30.6 parts by mass of methyl ethyl ketone (40% by mass) epoxy resin composition (3) Got.

  Next, with respect to 100 parts by mass of the epoxy resin composition (3), 0.4 part by mass of Curazole 2MAOK-PW (manufactured by Shikoku Kasei Co., Ltd., imidazole-based curing accelerator) is mixed and stirred for 10 minutes. As a result, an adhesive composition (b-1) was obtained.

(Preparation Example 7)
<Preparation of adhesive composition (b-2)>
Epicron N-680 (a cresol novolac type epoxy resin solution manufactured by DIC Corporation, epoxy equivalent 215 g / eq, 75% by mass of nonvolatile content) 37.3 parts by mass, “JER YL-7862” (Mitsubishi Chemical Corporation bisphenol A type epoxy resin solution, epoxy equivalent 3748 g / eq, non-volatile content 50% by mass) 24 parts by mass, and then mixed with 38.7 parts by mass of methyl ethyl ketone, whereby an epoxy resin composition (non-volatile content 40% by mass) ( 4) was obtained.

  Next, with respect to 100 parts by mass of the epoxy resin composition (4), 0.4 part by mass of Curazole 2MAOK-PW (manufactured by Shikoku Kasei Co., Ltd., imidazole-based curing accelerator) is mixed and stirred for 10 minutes. As a result, an adhesive composition (b-2) was obtained.

<Preparation of adhesive tape>
Example 1
Thickness after drying the adhesive composition (a-1) on the surface of a release film having one surface of a 75 μm-thick polyethylene terephthalate film peel-treated with a silicone compound, using a rod-shaped metal applicator. The adhesive layer (A-1) was produced by coating for 50 μm and drying for 10 minutes with a dryer set at 75 ° C.

  Next, after drying the adhesive composition (b-1) on the surface of the release film having one surface of a 75 μm-thick polyethylene terephthalate film peel-treated with a silicone compound, using a rod-shaped metal applicator. The adhesive layer (B-1) was prepared by applying the coating to a thickness of 100 μm and drying for 10 minutes with a dryer set at 75 ° C.

  The adhesive layer (B-1) is pasted on the adhesive layer (A-1) obtained above, and the adhesive layer is moved back and forth once using a 2 kg hand roller. The adhesive tape which the adhesive bond layer (B-1) laminated | stacked on the single side | surface of (A-1) was obtained.

(Example 2)
The same method as in Example 1 except that the adhesive composition (a-2) was used in place of the adhesive composition (a-1) and the adhesive layer (A-2) was formed. An adhesive tape was prepared.

Example 3
The same method as in Example 1 except that the adhesive composition (a-3) was used instead of the adhesive composition (a-1), and an adhesive layer (A-3) was formed. An adhesive tape was prepared.

Example 4
The same method as in Example 1 except that the adhesive composition (a-4) was used in place of the adhesive composition (a-1) and the adhesive layer (A-4) was formed. An adhesive tape was prepared.

(Example 5)
An adhesive layer (A-5) is formed by using the adhesive composition (a-5) instead of the adhesive composition (a-1), and the adhesive composition (b- An adhesive tape was produced in the same manner as in Example 1 except that the adhesive layer (B-2) was formed by using the adhesive composition (b-2) instead of 1).

(Example 6)
Thickness after drying the adhesive composition (a-1) on the surface of a release film having one surface of a 75 μm-thick polyethylene terephthalate film peel-treated with a silicone compound, using a rod-shaped metal applicator. The layer (A-1) was produced by applying for 50 minutes and drying for 10 minutes with a dryer set at 75 ° C.

  Next, a film made of polyethylene terephthalate having a thickness of 50 μm was bonded to one side of the adhesive layer (A-1).

  Next, after drying the adhesive composition (b-1) on the surface of the release film having one surface of a 75 μm-thick polyethylene terephthalate film peel-treated with a silicone compound, using a rod-shaped metal applicator. The adhesive layer (B-1) was prepared by applying the coating so that the thickness of the film became 50 μm and drying it with a dryer set at 75 ° C. for 10 minutes.

  Next, the adhesive layer (B-1) is attached to a film made of polyethylene terephthalate, and the adhesive layer (A- The adhesive tape which the polyethylene terephthalate film laminated | stacked on the single side | surface of 1), and the adhesive bond layer (B-1) laminated | stacked on the surface was obtained.

(Comparative Example 1)
Thickness after drying the adhesive composition (a-1) on the surface of a release film having one surface of a 75 μm-thick polyethylene terephthalate film peel-treated with a silicone compound, using a rod-shaped metal applicator. Was applied to a thickness of 150 μm and dried for 10 minutes with a drier set at 75 ° C. to obtain an adhesive tape comprising the adhesive layer (A-1).

(Comparative Example 2)
Thickness after drying the adhesive composition (b-1) on the surface of a release film obtained by peeling one side of a 75 μm thick polyethylene terephthalate film with a silicone compound, using a rod-shaped metal applicator. Was applied to be 150 μm and dried to obtain an adhesive tape comprising the adhesive layer (B-1).

[Adhesive tape and method for measuring expansion coefficient of each adhesive layer constituting it]
The thickness of the adhesive tape produced by the above method and the thickness of each adhesive layer constituting it were measured using a thickness meter.

  Further, the adhesive tape was expanded by being left in an environment at 130 ° C. for 1 hour.

  Next, the thickness of the expanded adhesive tape and the thickness of the adhesive layer constituting it were measured using a thickness meter.

  The expansion coefficient of the pressure-sensitive adhesive layer (A) was calculated by the following method.

  The thickness of the adhesive layer (A) constituting the adhesive tape before being left for 1 hour in a 130 ° C. environment (before expansion) was measured in a 23 ° C. environment.

  The adhesive tape was left in an environment at 130 ° C. for 1 hour.

  The adhesive tape after standing was taken out in an environment of 23 ° C., and the thickness of the adhesive layer (A ′) formed by immediately expanding the adhesive layer (A) was measured.

The expansion coefficient was calculated based on the measurement result and the following formula.
[The thickness of the adhesive layer (A) constituting the adhesive tape after standing] [The thickness of the adhesive layer (A ') formed by swelling] / of the adhesive layer (A) constituting the adhesive tape before standing Thickness] × 100
The expansion coefficient of the pressure-sensitive adhesive layer (B) was calculated by the following method.

  The thickness of the adhesive layer (B) constituting the adhesive tape before being left for 1 hour in a 130 ° C. environment (before expansion) was measured in a 23 ° C. environment.

  The adhesive tape was left in an environment at 130 ° C. for 1 hour.

  The adhesive tape after the standing was taken out in an environment of 23 ° C., and the thickness of the adhesive layer (B ′) corresponding to the adhesive layer (B) was immediately measured.

The expansion coefficient was calculated based on the measurement result and the following formula.
[The thickness of the adhesive layer (B ′) constituting the adhesive tape after being left / the thickness of the adhesive layer (B) constituting the adhesive tape before being left] × 100
The expansion coefficient of the adhesive tape was calculated by the following method.

  The thickness of the adhesive tape before being left for 1 hour in a 130 ° C. environment (before expansion) was measured in a 23 ° C. environment.

  The adhesive tape was left in an environment at 130 ° C. for 1 hour.

  The adhesive tape after being left standing was taken out in an environment of 23 ° C., and its thickness was immediately measured.

The expansion coefficient was calculated based on the measurement result and the following formula.
[Thickness of the adhesive tape after being left / thickness of the adhesive tape before being left] × 100

[Measurement method of shear adhesive strength 1]
Corresponds to the adhesive layer (A) of an adhesive tape cut to a size of 10 mm × 10 mm on the surface of a degreased smooth aluminum plate (width 15 mm × length 70 mm × thickness 0.5 mm) The surface was affixed and pressure-bonded using a 2 kg hand roller.

  Next, another aluminum plate (width 15 mm × length 70 mm × thickness 0.5 mm) having a smooth surface subjected to degreasing is placed on the upper surface of the adhesive tape (the surface corresponding to the adhesive layer (B)). These were fixed with clips.

  The fixed one was heated at 130 ° C. for 1 hour, and then allowed to stand in a 23 ° C. environment for 30 minutes and cooled.

  Next, the sample with the clip removed is used as a test piece, the ends of the two aluminum plates are chucked, and a tensile test is performed in a 180 ° direction at a tensile speed of 5 mm / min. The adhesive strength of the adhesive tape was determined.

[Measurement method of shear adhesive strength 2]
Two surface-smoothed aluminum plates having a width of 15 mm, a length of 70 mm and a thickness of 0.5 mm are degreased, and the end of the upper surface (C1-1) of one aluminum plate (C1) (1 in FIG. 1) In addition, two spacers (3 in FIG. 1) having a thickness of 0.3 mm were arranged in parallel with a gap of 12 mm, and adhered using an adhesive.

  Next, a 10 mm × 10 mm adhesive tape (4 in FIG. 1) was attached on the upper surface (C1-1) side of the aluminum plate (C1) and between the two spacers.

  Next, the other aluminum plate (C2) (2 in FIG. 1) was placed on top of the spacer and fixed with a clip. This was heated at 130 ° C. for 1 hour, and the adhesive tape was expanded to thermally bond the two aluminum plates.

  After the heat-bonded material was cooled at 23 ° C. for 30 minutes, the adhesive strength of the material from which the clip was removed was chucked at each end of the aluminum plate using a tensile tester, and the direction of 180 ° It was measured by carrying out a tensile test at a tensile speed of 5 mm / min (in the shear direction).

The shear adhesive strength 2 was evaluated is preferably approximately 120 N / cm ² or more, and more preferably 300N / cm ² or more, and still more preferably 450 N / cm ² or more.

  In addition, as for the adhesive tape obtained in Examples 1-6 and the comparative example 1, the surface equivalent to the expansible adhesive bond layer (A) which comprises it is affixed on the upper surface (C1-1) of the said aluminum plate. Thus, the above test was conducted. In addition, the adhesive tape obtained in Comparative Example 2 was subjected to the above test such that the surface corresponding to the adhesive layer (B) was stuck to one surface (C1-1) of the aluminum plate.

  Moreover, as Reference Examples 1-5, the surface corresponding to the said adhesive bond layer (B) which comprises the adhesive tape obtained in Examples 1-5 is affixed previously on the upper surface (C1-1) of the said aluminum plate. The adhesive layer (A) that can expand by stimulation is the same as the above [Method for measuring shearing adhesive force 2] except that it is arranged so as to come into contact with the aluminum plate (C2) after expansion. Shear adhesion was measured.

1 Aluminum plate (C1)
2 Aluminum plate (C2)
3 Spacer 4 Adhesive tape 5 Gap between adhesive tape and aluminum plate (C2)

Claims (9)

An adhesive tape having an adhesive layer (B) on one side of an adhesive layer (A) containing a thermosetting resin containing a cresol novolac type epoxy resin and an expansion agent, directly or via another layer, The expansion rate in the thickness direction of the adhesive layer (A) after leaving the adhesive tape in an environment of 130 ° C. for 1 hour [thickness of the adhesive layer (A) after standing / before the standing The thickness of the adhesive layer (A)] × 100 is 200% or more, and the expansion rate in the thickness direction of the adhesive layer (B) [the thickness of the adhesive layer (B) after being left / The thickness of the adhesive layer (B) before leaving] × 100 is 120% or less, and the adhesive layer (A) is a layer that can expand in the thickness direction by stimulation, And an adhesive layer previously attached to the adherend. The adhesive tape according to claim 1, wherein the thermosetting resin is contained in an amount of 10% by mass to 99% by mass with respect to the entire adhesive layer (A). The adhesive layer (A) contains a cresol novolac type epoxy resin and a bisphenol A type epoxy resin, and [cresol novolac type epoxy resin / bisphenol A type epoxy resin] (mass ratio) is 16.05 / 24. The adhesive tape according to claim 1, wherein the adhesive tape is in a range of ˜27.975 / 12. The adhesive tape according to any one of claims 1 to 3, wherein the adhesive layer (B) is a thermosetting adhesive layer or a pressure-sensitive adhesive layer. The adhesive layer (A) has a thickness of 10 μm to 250 μm, and the adhesive layer (B) has a thickness of 5 μm to 150 μm. The adhesive tape as described in the item. The said adhesive bond layer (B) is laminated | stacked on the single side | surface of the said adhesive bond layer (A) through the layer (Z) which consists of a resin film or a metal, The any one of Claims 1-5. Adhesive tape. A member which constitutes the adherend (C1) (c1-1), said the other portions constituting the adherend (C1) (c1-2) or other adherend (C2), according to claim 1 It is the adhesion | attachment method adhere | attached with the adhesive tape of any one of -6 ,
The step [1] of previously bonding the adhesive layer (A) before expansion constituting the adhesive tape and the portion (c1-1) constituting the adherend (C1), and at least the adhesive layer By stimulating and expanding (A), the adhesive layer (B) constituting the adhesive tape and the part (c1-2) constituting the adherend (C1) or the adherend (C2) A bonding method, comprising the step [2] of bonding to each other. The part (c1-1) constituting the adherend (C1) and the other part (c1-2) or the other adherend (C2) constituting the adherend (C1) are defined in claim 1. A method for producing an article bonded with the adhesive tape according to any one of -6,
The step [1] of previously bonding the adhesive layer (A) constituting the adhesive tape and the site (c1-1) constituting the adherend (C1), and at least the adhesive layer (A) The adhesive layer (B) constituting the adhesive tape and the part (c1-2) constituting the adherend (C1) or the adherend (C2) are adhered by stimulating and expanding the adhesive tape. The manufacturing method of the articles | goods characterized by including the process [2] to make. The adhesive layer (A) constituting the adhesive tape according to any one of claims 1 to 6 and a part of the magnet are pre-adhered in a gap of the core member constituting the motor. A method for manufacturing a motor, comprising: a structure in which the magnet is fixed in the gap by stimulating and expanding at least the adhesive layer (A) after being placed.

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