JP2018203863A - Adhesive tape, article, and manufacturing method of article - Google Patents

Abstract

To provide an adhesive tape capable of being expanded by heating, having excellent adhesive force eve after heat expansion, further having no risk for inflammation even when the adhesive tape is stood under a high temperature in a practically sealed space.SOLUTION: There is provided an adhesive tape used in a practically sealed space, having a thermally expansible adhesive layer (A), in which the thermally expansible adhesive layer (A) contains an adhesive composition (a) and a thermally expansible capsule, and content of the thermally expansible capsule is 3 to 100 pts.mass based on 100 pts.mass of all solid components of the adhesive composition (a).SELECTED DRAWING: None

Description

  The present invention relates to an adhesive tape having a configuration capable of expanding in the thickness direction by giving a stimulus such as heating at a low temperature for a short time.

  In general, the adhesive tape can be suitably used for fixing one adherend to a flat surface portion or a curved surface portion of the other adherend, such as an automobile member or an electric device. Widely used in various product manufacturing scenes.

  On the other hand, the use range of the adhesive tape is expected to expand further, and the adhesive tape is suitable for the case where, for example, the other adherend is fixed in the gap of one adherend. It is demanded that it can be used. Specifically, as a motor mounted on a hybrid vehicle or the like, a motor having a configuration in which a magnet is embedded in a predetermined position (gap) of a core part (rotor core) is generally known. It has been studied to use the adhesive tape when fixing the magnet in the gap of the.

  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 tape that forms a second adhesive layer on a second surface is known (see, for example, Patent Document 1).

As the heat-expandable adhesive tape, one that realizes expansibility by adding a thermal expansion agent to the adhesive layer is known, and in particular, it is known to add a volume expansion agent by vaporization of flammable gas. ing. However, when the volume expansion agent is used, the flammable gas is released from the adhesive tape when left for a long time at a high temperature, and when used in a sealed space, the flammable gas stays, When an ignition source such as an electrostatic spark is generated inside an article, the danger of ignition is regarded as a problem.

JP 2010-023559 A

  The problem to be solved by the present invention is that the adhesive tape can be expanded by heating and has an excellent adhesive force even after heating and expansion, and the adhesive tape is kept at a high temperature for a long time in a substantially sealed space. The object is to provide an adhesive tape that does not ignite even if left untreated.

  The present inventors are an adhesive tape used in a substantially sealed space, the adhesive tape has a thermally expandable adhesive layer (A), and the thermally expandable adhesive layer (A) The adhesive composition (a) and a thermally expandable capsule are contained, and the content of the thermally expandable capsule is 3 to 100 parts by mass with respect to 100 parts by mass of the total solid component of the adhesive composition (a). The above problems were solved with adhesive tape.

  The adhesive tape of the present invention can sufficiently fill or bond the voids of the adherend and the gap between two or more adherends with excellent adhesive force. Further, the adhesive tape can be left in a sealed space at a high temperature for a long time, and even if flammable gas stays, it can be used safely without igniting.

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

  This adhesive tape is an adhesive tape used in a substantially sealed space, the adhesive tape has a thermally expandable adhesive layer (A), and the thermally expandable adhesive layer (A) It contains an adhesive composition (a) and a thermally expandable capsule, and the content of the thermally expandable capsule is 3 to 100 parts by mass with respect to 100 parts by mass of the total solid components of the adhesive composition (a). Is an adhesive tape characterized by

  The adhesive tape of the present invention includes a single layer or two or more layers of the thermally expandable adhesive layer (A), the thermally expandable adhesive layer (A) and other expandable adhesives. Adhesive tape composed of a layer (for example, a photo-expandable adhesive layer or a thermosetting expandable adhesive layer), an adhesive layer (for example, described later) that is difficult to expand with the thermal expandable adhesive layer (A) Adhesive tape (B) or the like) and the like.

  Especially, as said adhesive tape, it is the space | gap which adherend (C1) has to use the adhesive tape comprised by the said thermally expansible adhesive bond layer (A) and other adhesive bond layers, for example. Alternatively, it is preferable for filling the space between the adherend (C1) and the adherend (C2) with the expanded product of the adhesive tape and firmly bonding the gap.

  As an adhesive tape composed of the thermally expandable adhesive layer (A) and other adhesive layers, specifically, at least one surface of the thermally expandable adhesive layer (A) will be described later. It is preferable to use one having an adhesive layer (B). As the adhesive tape, the thermally expandable adhesive layer (A) and the adherend may be bonded to the adherend in advance before the expansion. It is preferable for maintaining excellent adhesion.

  The thermally expandable adhesive layer (A) is a layer that can expand by heating, for example. The heat-expandable adhesive layer (A) includes an expansion coefficient in the thickness direction of the heat-expandable adhesive layer (A) [thickness of the heat-expandable adhesive layer (A) after standing after heating / The thickness of the heat-expandable adhesive layer (A) before standing] × 100 is 150% or more. The expansion coefficient is preferably 200% or more, and more preferably 250% to 1000%. With such an adhesive tape, for example, when the height (thickness) of the gap between the adherend (C1) or the gap between the adherend (C1) and the adherend (C2) is large. Even if it exists, by expanding the said adhesive tape, the other to-be-adhered body can be suitably fixed in the said space | gap, or the said space | gap can be filled up with the said adhesive tape. Further, with the adhesive tape, even if the surface of the adherend is a rough surface, the other adherend can be suitably fixed to the rough surface.

  Note that the expansion rate is determined by the temperature of the adhesive tape when the adhesive tape is left in an environment of 100 ° C. for 30 minutes with respect to the thickness of the heat-expandable adhesive layer (A) before the expansion (before expansion). It refers to the ratio of the thickness of the thermally expandable adhesive layer (A1) formed by expanding the expandable adhesive layer (A).

  The thickness of the thermally expandable adhesive layer (A) before expansion is preferably in the range of 10 μm to 250 μm, more preferably in the range of 20 μm to 200 μm, and in the range of 30 μm to 150 μm. Further, it is more preferable for obtaining a further excellent adhesive strength.

  On the other hand, the thickness of the thermally expandable adhesive layer (A1) formed by expanding the thermally expandable adhesive layer (A) is preferably in the range of 15 μm to 2500 μm, and in the range of 20 μm to 1500 μm. It is preferable in order to obtain a further excellent adhesive force. The thermally expandable adhesive layer (A1) preferably has a porous structure.

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

  The thermally expandable adhesive layer (A) contains an adhesive composition (a). The heat-expandable adhesive layer (A) can be produced by applying the adhesive composition (a) to, for example, a release liner or a support of an adhesive tape and drying.

  As the adhesive composition (a), a known adhesive constituent resin can be used. As the adhesive constituent resin, thermoplastic resins, thermosetting resins, and mixtures thereof can be used, and epoxy resins, urethane resins, silicone resins, phenol resins, urea resins, fluororesins, acrylonitrile resins. In addition, vinyl resins such as acrylic resin, styrene resin, and butadiene resin can be used alone or in combination of two or more.

When a thermoplastic resin is used for the adhesive composition (a), it is preferable that the thermoplastic composition contains 50 parts by mass or more with respect to 100 parts by mass of the total solid components of the adhesive composition (a). More preferably, it contains more than 90 parts by mass, more preferably more than 90 parts by mass.

As the thermoplastic resin, a resin that can be easily expanded by heating can be used. The thermoplastic resin, the storage modulus _{G 23} as measured by dynamic viscoelasticity spectrum at 1Hz and 23 ° C. to use what is in a range of ^{1.0 × 10 3 ~5.0 × 10 7} Pa It is preferable that a storage elastic modulus G ₇₀ measured by a dynamic viscoelastic spectrum at 1 Hz and 70 ° C. is in the range of 1.0 × 10 ^{2 to} 1.0 × 10 ⁷ Pa. It is preferable that the storage elastic modulus G ₁₂₀ measured by a dynamic viscoelastic spectrum at 1 Hz and 120 ° C. is in the range of 1.0 × 10 ^{2 to} 1.0 × 10 ⁶ Pa. It is particularly preferable to obtain an adhesive tape that can prevent the adhesive tape from being peeled off or displaced from the adherend even before heating and can expand to a level that can sufficiently fill the gap.

The adhesive tape in the state before expanding the heat-expandable adhesive layer (A) can prevent the adhesive tape from peeling off or being displaced from the adherend even before heating, and in a room temperature environment after expansion. in contraction storage modulus _{G 23} is preferably ^{1.0 × 10 3 ~5.0 × 10 7} Pa as measured with a dynamic viscoelasticity spectrum at 1Hz and 23 ° C. in order to suppress, more preferably 5 Those containing a thermoplastic resin of 0.0 × 10 ^{3 to} 1.0 × 10 ⁷ Pa, particularly preferably 5.0 × 10 ^{3 to} 5.0 × 10 ⁶ Pa can be used.

Further, the thermoplastic resin, which has a storage modulus G ₂₃ as measured by dynamic viscoelasticity spectrum at 1Hz and 23 ° C. within the above range, dynamic at 1Hz in the range of 70 ° C. to 120 ° C. Use of a material having a storage elastic modulus measured by a viscoelastic spectrum in the range of 1.0 × 10 ² Pa to 1.0 × 10 ⁷ Pa in the plane direction (flow direction or width direction) of the adhesive tape. It is preferable for suppressing the expansion of the film and expanding in the thickness direction.

As the thermoplastic resin, a storage elastic modulus G ₇₀ measured by a dynamic viscoelastic spectrum at 1 Hz and 70 ° C. is preferably 1.0 × 10 ^{2 to} 1.0 × 10 ⁷ Pa, more preferably 5. ^{0 × 10 2 ~5.0 × 10 6} Pa, particularly preferably be used those ^{5.0 × 10 2 ~1.0 × 10 6} Pa.

Further, the thermoplastic resin, 1 Hz and preferably is storage modulus _{G 70} as measured by dynamic viscoelasticity spectrum at ^{70 ℃ 1.0 × 10 2 ~1.0 ×} 10 7 Pa, more preferably ^{5.0 × 10 2 ~5.0 × 10 6} Pa, particularly preferably be used those ^{5.0 × 10 2 ~1.0 × 10 6} Pa.

The storage elastic modulus G ₁₂₀ measured by a dynamic viscoelastic spectrum at 1 Hz and 120 ° C. of the thermoplastic resin is preferably 1.0 × 10 ^{2 to} 1.0 × 10 ⁶ Pa. It is more preferably 0.0 × 10 ^{2 to} 5.0 × 10 ⁶ Pa, and further preferably 5.0 × 10 ^{2 to} 2.0 × 10 ⁵ Pa.

The storage elastic modulus G ₁₂₀ of the thermoplastic resin is smaller it is preferable than the storage elastic modulus G _70, the storage elastic modulus G _70, it is preferable that the smaller than the storage modulus G _23.

The measurement of the storage modulus G _23, G ₇₀ and G ₁₂₀ are using a commercial viscoelastic tester, was measured by the method described in the examples below. As a test piece for the measurement, tapes obtained by applying a thermoplastic resin (not containing an expanding agent) contained in the thermally expandable adhesive layer (A) onto a release liner and drying, etc. And a test piece having a thickness of 2 mm was prepared and used.

  The thermoplastic resin has, for example, excellent adhesive strength before expansion, softens at the expansion start temperature of the expansion agent, the expansion agent easily expands, and can exhibit excellent adhesive strength even after expansion Is preferably used.

  Examples of the thermoplastic resin include urethane resins such as polyurethane (PU) and thermoplastic polyurethane (TPU); polycarbonate (PC); polyvinyl chloride (PVC) and vinyl chloride such as vinyl chloride-vinyl acetate copolymer resin. Resins such as polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polymethyl methacrylate (PMMA), polyethyl methacrylate, etc .; polyethylene terephthalate (PET), polybutylene terephthalate, Polyester resins such as polytrimethylene terephthalate, polyethylene naphthalate and polybutylene naphthalate; Polyamide resins such as nylon (registered trademark); Polystyrene (PS), Imido-modified polystyrene, Acrylonitrile butadiene, Styrene (ABS) resin, imide ABS resin, styrene-acrylonitrile copolymer (SAN) resin, polystyrene resins such as acrylonitrile, ethylene-propylene-diene, styrene (AES) resin, polyethylene (PE) resin, polypropylene (PP) resin, cycloolefin resin, etc. Olefin resins; Cellulosic resins such as nitrocellulose and cellulose acetate; Silicone resins; Thermoplastic resins such as fluororesins, Styrenic thermoplastic elastomers, Olefin thermoplastic elastomers, Vinyl chloride thermoplastic elastomers, Urethane heat Examples include thermoplastic elastomers such as plastic elastomers, ester-based thermoplastic elastomers, and amide-based thermoplastic elastomers.

  Among these thermoplastic resins, among them, styrene thermoplastic elastomer, olefin thermoplastic elastomer, vinyl chloride thermoplastic elastomer, ester thermoplastic elastomer, urethane thermoplastic elastomer, amide thermoplastic elastomer or acrylic It is preferable to use a styrene resin or the like, and it is particularly preferable to use a styrene thermoplastic elastomer or an acrylic resin.

  Examples of the styrenic thermoplastic elastomer include styrene-based AB diblock copolymers such as styrene-ethylene-butylene copolymer (SEB); styrene-butadiene-styrene copolymer (SBS), and hydrogenated product of SBS. (Styrene-ethylene-butylene-styrene copolymer (SEBS)), styrene-isoprene-styrene copolymer (SIS), hydrogenated product of SIS (styrene-ethylene-propylene-styrene copolymer (SEPS)), styrene -Styrenic ABA type triblock copolymer such as isobutylene-styrene copolymer (SIBS); Styrene type ABAB type tetrablock copolymer such as styrene-butadiene-styrene-butadiene (SBSB); Styrene-butadiene-styrene- Butadiene-styrene (SBSBS), etc. Styrene-based ABABA-type pentablock copolymer; Styrene-based multiblock copolymer having AB repeating units higher than these; Hydrogenation of ethylenic double bonds of styrene-based random copolymers such as styrene-butadiene rubber (SBR) And the like. A commercially available styrene thermoplastic elastomer may be used.

  As said acrylic resin, what is obtained by superposing | polymerizing the monomer containing an alkyl (meth) acrylate can be used, for example.

  As the alkyl (meth) acrylate, a (meth) acrylate having an alkyl group having 4 to 12 carbon atoms is preferably used. Specifically, butyl (meth) acrylate, isooctyl (meth) acrylate, 2- Ethylhexyl (meth) acrylate or the like is preferably used, and butyl acrylate and 2-ethylhexyl acrylate are preferably used alone or in combination.

  In addition to those described above, acrylonitrile, (meth) acrylic acid, maleic anhydride, acrylamide, itaconic acid, styrene, vinyl acetate and the like can be used as the monomer.

  When using a thermosetting resin for the adhesive composition (a), it is preferable that the thermosetting component is contained in an amount of 50 parts by mass or more with respect to 100 parts by mass of the total solid component of the adhesive composition (a). More preferably 75 parts by mass or more, more preferably 90 parts by mass or more.

  Among these, it is preferable to use an epoxy resin as the thermosetting resin in order to obtain an adhesive tape having excellent heat resistance even after expansion.

  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.

The thermally expandable adhesive layer (A) contains thermally expandable capsules. As the heat-expandable capsule, for example, a microcapsule of a hydrocarbon solvent can be used. As the thermally expandable capsule, it is preferable to use a capsule capable of generating gas and expanding at a temperature around the softening point of the thermoplastic resin. The expansion start temperature of the thermally expandable capsule is preferably 50 ° C to 150 ° C, preferably 60 ° C to 145 ° C, and preferably 70 ° C to 140 ° C.
Examples of commercially available thermal expansion capsules include EXPANSELL (manufactured by Nippon Philite Co., Ltd.), Matsumoto Microsphere (manufactured by Matsumoto Yushi Seiyaku Co., Ltd.), and Microsphere (manufactured by Kureha Co., Ltd.).

  Among the above-mentioned thermally expandable capsules, among them, the use of thermally expandable capsules in which a hydrocarbon solvent is microencapsulated can reduce deterioration of the thermally expandable adhesive layer (A) due to the influence of heat or the like. It is more preferable in preventing. The aforementioned expandable capsules can be used alone or in combination of two or more.

  The content of the thermally expandable capsule is preferably in the range of 3 parts by mass to 100 parts by mass with respect to 100 parts by mass of the total solid component of the thermally expandable adhesive layer (A). More preferably in the range of 50 parts by mass, the range of 5 to 30 parts by mass can expand sufficiently to fill the voids of the adherend and is sealed. It is more preferable that the adhesive tape is left in a space for a long period of time in an environment that is equal to or higher than the expansion start temperature of the thermally expandable capsule, and when flammable gas is retained, it does not ignite even if there is an ignition source.

As the adhesive composition (a), it is preferable to use a thermoplastic resin because it has an excellent adhesive force before expansion by heating.

  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.

  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 above-mentioned, as an adhesive tape of this invention, it is preferable to use what has an adhesive bond layer (B).

  As an adhesive layer (B) which comprises the said adhesive tape, it can form using the adhesive composition (b) which can form the layer which has adhesiveness or adhesiveness.

  As the adhesive layer (B), the expansion rate in the thickness direction of the adhesive layer (B) [the thickness of the adhesive layer (B) after being left after heating / the adhesive layer before being left ( Thickness of B)] × 100 of 120% or less can be used. The expansion ratio of the adhesive layer (B) is preferably 115% or less, and more preferably 110% or less. With such an adhesive tape, even after the thermally expandable adhesive layer (A) is expanded, excellent adhesive force to the adherend can be maintained. It should be noted that the expansion rate of the adhesive layer (B) is determined after the standing relative to the thickness of the adhesive layer (B) before leaving when the adhesive tape is left in an environment of 100 ° C. for 30 minutes. It refers to the ratio of the thickness of the adhesive layer.

  The thickness of the adhesive layer (B) is preferably in the range of 1 μm to 150 μm, and in the range of 5 μm to 100 μm, the thermally expandable adhesive layer (A) constituting the adhesive tape is expanded. The gap between the adherend (C1) or the gap between the adherend (C1) and the adherend (C2) is filled, and the adhesive layer (B) is adhered to the adherend (C2). It is more preferable because it can exhibit an excellent adhesive force when it is attached to the surface.

  Since it is preferable that the adhesive layer (B) has a low expansion coefficient as described above, the adhesive layer (B) substantially contains the expansion agent exemplified as being usable when forming the thermally expandable adhesive layer (A). It is preferable not to.

  As the adhesive (B), for example, an adhesive composition (b) containing a resin such as a thermosetting resin or a thermoplastic resin and containing little or no content of the expansion agent is preferably used. it can.

  As a resin that can be used for the adhesive composition (b), a conventionally known resin can be selected and used. Especially, as said resin, in order to improve the production efficiency of the adhesive tape of this invention, what was illustrated as an adhesive composition (a) which can be used for formation of the said thermally expansible adhesive layer (A), for example And the like are preferably used.

  As said adhesive composition (b), in addition to the said adhesive plastic material (b), what contains tackifying resin, a crosslinking agent, another additive etc. as needed can be used.

  Examples of the tackifying resin include a rosin-based tackifying resin, a polymerized rosin-based tackifying resin, a polymerized rosin ester-based tackifying resin, and a rosin phenol for the purpose of adjusting the strong adhesiveness of the adhesive layer (B). Tackifying resins, stabilized rosin ester tackifying resins, disproportionated rosin ester tackifying resins, terpene tackifying resins, terpene phenol tackifying resins, petroleum resin tackifying resins, etc. can be used. .

  Examples of the crosslinking agent include known isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, polyvalent metal salt crosslinking agents, metal chelates for the purpose of improving the cohesive strength of the adhesive layer (B). A cross-linking agent, a keto-hydrazide cross-linking agent, an oxazoline cross-linking agent, a carbodiimide cross-linking agent, a silane cross-linking agent, a glycidyl (alkoxy) epoxy silane cross-linking agent, or the like can be used.

  Examples of the additive include a base for adjusting pH (such as aqueous ammonia), an acid, a foaming agent, a plasticizer, a softening agent, an antioxidant, as long as the desired effect of the present invention is not inhibited as necessary. Glass or plastic fiber, balloon, bead, metal powder fillers, pigments, colorants such as dyes, pH adjusters, film formation aids, leveling agents, thickeners, water repellents, water A well-known thing, such as a foaming agent, can be used.

  As said adhesive composition (b), what maintains a solvent can be used when maintaining favorable coating workability | operativity etc. As the solvent, for example, toluene, xylene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, hexane and the like can be used. Moreover, when using an aqueous adhesive composition as the adhesive composition (b), water or an aqueous solvent mainly composed of water can be used as the solvent.

  The adhesive tape of this invention can be used for the use which fills the space | gap which an adherend (C1) has, or the space between an adherend (C1) and an adherend (C2). Further, when the surfaces of the adherend (C1) and the adherend (C2) are uneven, the adhesive tape is placed on the adherend (C1), and the adhesive tape is heated to expand, It can be used for the purpose of filling and adhering the gap formed by the irregularities on the surface of the adherend (C1) and adherend (C2).

  Further, the adhesive tape of the present invention includes the expanded adhesive layer (A1) or the adhesive layer (B) and the adherend by a force generated by expanding the thermally expandable adhesive layer (A). Since the body (C1) and the adherend (C2) are pressure-bonded, for example, the inside of an article that cannot be directly pressed, or for fixing a brittle member that is broken or deformed by direct pressure can do.

  The adhesive tape of the present invention is produced by, for example, passing through the step [I] of forming the thermally expandable adhesive layer (A) by applying the adhesive composition (a) to a release liner and drying it. Can do.

  Among the adhesive tapes of the present invention, the adhesive tape constituted by the thermally expandable adhesive layer (A) and the adhesive layer (B) is separate from the step [I] and the step [I]. The step [II] of forming the adhesive layer (B) by applying the adhesive composition (b) to a release liner and drying, etc., and the one side of the thermally expandable adhesive layer (A) It can be manufactured by transferring the adhesive layer (B) and passing through the step [III] for pressure bonding.

  In addition, it is preferable that the said thermally expansible adhesive layer (A) does not expand | swell substantially in the process of manufacturing the said adhesive tape.

  Moreover, as an adhesive tape of this invention, the layer (Z) which consists of a nonwoven fabric layer or a resin film layer, or a metal between the said thermally expansible adhesive bond layer (A) and an adhesive bond layer (B) as needed. What you have can be used. Since such an adhesive tape has good rigidity, it is excellent in sticking workability.

  As the layer (Z), for example, if it is a non-woven fabric, the material is preferably made of pulp, rayon, manila hemp, acrylonitrile, nylon, polyester, etc. In addition, a one-step impregnation treatment in which polyamide is added and coating after drying, a two-step impregnation treatment using viscose or a thermoplastic resin as a binder may be performed. As a resin film, a polyester film, a polyethylene film, a polypropylene film, a polyvinyl chloride film, a resin film layer formed using a plastic film such as a polyimide film, etc., and as a layer made of metal, a metal layer such as aluminum or copper Is mentioned.

  The layer (Z) preferably has a thickness of 1 μm to 200 μm.

  For the adhesive tape having the layer (Z), for example, the step [I] of forming the heat-expandable adhesive layer (A) by applying the adhesive composition (a) to a release liner and drying it [I], the step Apart from [I], the step [II] of forming the adhesive layer (B) by applying the adhesive composition (b) to a release liner and drying, etc., and the thermally expandable adhesive layer (A Step [IV] of laminating the layer (Z) on one side of the above) and Step [V] of transferring the adhesive layer (B) to the surface comprising the layer (Z) and press-bonding them. Can be manufactured.

  Since the adhesive tape of the present invention obtained by the above method can be expanded by heating and has an excellent adhesive force, it is exclusively the void of the adherend (C1) or the adherend (C1) and the adherend. The space between the bonded body (C2) can be suitably used in the production scene of an article filled or bonded with the expanded product of the adhesive tape of the present invention.

  As the method for manufacturing the article, for example, the step [1] of applying the thermally expandable adhesive layer (A) of the adhesive tape to the part (c1-1) constituting the adherend (C1), the thermal expansion A step [2] of heating the heat-adhesive adhesive layer (A), a step [3] in which the heat-expandable adhesive layer (A1) is formed by expansion of the heat-expandable adhesive layer (A) by the heating, And the thermally expansible adhesive layer (A1) or the adhesive layer (B) constituting the adhesive tape is another part (c1-2) or another adherend constituting the adherend (C1). The manufacturing method of the article | item which has process [4] affixed on (C2) is mentioned.

  In the step [1], the heat-expandable adhesive layer (A) of the adhesive tape is pressure-bonded to the site (c1-1) constituting the adherend (C1) with a force of 0.1 N / cm 2 or more. The adhesive force of the adhesive tape to the part (c1-1) constituting the adherend (C1) is increased, and the deviation between the adhesive tape and the adherend (C1) can be suppressed even before heating. .

  When press-bonding the thermally expandable adhesive layer (A) of the adhesive tape to the part (c1-1) constituting the adherend (C1), an apparatus such as a press or a roller is used as necessary. They may be used and may be pressed with a finger.

  The heating temperature in the step [2] is preferably a temperature corresponding to, for example, a temperature at which the expansion agent expands (expansion start temperature), specifically, preferably 50 to 150 ° C., 60 to 145 ° C. is more preferable, and 70 to 140 ° C. is excellent in stability during storage, and the adhesive tape is sufficiently expanded without damaging the adherend having low heat resistance, and excellent after expansion. It is preferable because an adhesive force can be obtained.

  As the heating method, for example, the article is put into a heating device such as an oven or a heating furnace, and the whole article is heated, or the thermally expandable adhesive layer (A), the adhesive tape, or the adherend is applied. The method of heating the said thermally expansible adhesive layer (A) by making a heat source contact or approach is mentioned.

  As the heat source, for example, a halogen lamp, a laser irradiation device, an electromagnetic induction heating device, a hot stamp, a hot plate, a soldering iron, or the like can be used. The heating method can be selected depending on the size of the article.

  The adhesive tape of the present invention preferably expands in the thickness direction after the heating, and preferably does not substantially expand in the flow direction or the width direction.

  Through the step [2], the thermally expandable adhesive layer (A) expands to form a thermally expandable adhesive layer (A1) (step [3]). The heat-expandable adhesive layer (A1) expands mainly in the thickness direction of the adhesive tape due to the expansion.

  In the step [4], the adhesive layer (A1) or the adhesive layer (B) and the adherend (C1) are generated by the force generated by expanding the thermally expandable adhesive layer (A). Is bonded to the other part (c1-2) or the other adherend (C2). Therefore, it is necessary to apply pressure using, for example, a press machine or the like when filling the voids of the adherend (C1) or the gaps between the adherend (C1) and the adherend (C2). Absent. In addition, since the adhesive tape and the adherend are brought into close contact with each other by the force generated by the expansion, the adhesive tape is used even when the adherend has an uneven surface (having a rough surface). It is difficult to form a gap between the substrate and the adherend.

  Examples of the adherends (C1) and (C2) include metals such as glass and aluminum, and plastics made of resin such as acrylic and polycarbonate. As said adherend (C1) and (C2), what consists of the same material and shape may be used, and the thing of a different material and shape may be used.

  As the adherends (C1) and (C2), the surface with which the thermally expandable adhesive layer (A) or the adhesive layer (B) is in contact may be a rough surface.

  The shape of the adherend (C1) and the adherend (C2) is not particularly defined, and examples thereof include a two-dimensional shape, a three-dimensional shape (curved surface, etc.), a shape having surface irregularities, and a fitting shape. It is done. A combination of the above shapes may also be used.

  The adhesive tape of the present invention can be expanded by applying heat to the thermally expandable adhesive layer (A) or the entire adhesive tape.

  As the method for producing the article, the steps [1], [2] and [3] are performed in this order, and have excellent adhesive force before heating, can be expanded by heating, and heated. It is preferable for exhibiting excellent adhesive force even after expansion. In particular, when the surface of the adherend (C1) or (C2) is a rough surface, it is effective in expressing good adhesive force.

  For example, even when an adhesive tape that has been heated and expanded in advance through the step [2] is used to attach to an adherend with surface irregularities, a fine gap is formed at the interface between them. The possibility of being reduced can be reduced.

  The adhesive tape of the present invention is used in a substantially sealed space. However, in the state where the atmospheric pressure is balanced inside and outside the substantially sealed space, the exchange of air is substantially inside and outside the space. It is closed without gaps so that it does not happen. Therefore, even if there is an inflow of air by raising the air pressure inside or outside the space, if there is no substantial exchange of air inside and outside the space in a state where the air pressure is suspended inside and outside the space, This corresponds to a substantially sealed space. Therefore, for example, an air leak test (a test in which air is introduced into the workpiece (inside the test object) to increase the pressure inside the workpiece, causing a pressure difference between the inside and outside of the workpiece, and detecting air leakage. If there is a leak, the pressure in the work will drop, so the leak will be detected by monitoring the change in the pressure in the work.) I don't say it's not a space.

When the adhesive tape is used in the substantially sealed space, a value obtained by dividing the adhesion area (cm ² ) of the adhesive tape by the volume (cm ³ ) of the sealed space is 0.001 to 50 cm ⁻ preferably ¹ is, more preferably 0.001～40Cm ^-1, more preferably from 0.002～15Cm ^-1, to be 0.005～15Cm ^-1, with adhesive tape Since an area sufficient for fixing the member can be secured, it is more preferable that the adhesive tape is left at a high temperature for a long period of time while maintaining sufficient adhesion, and even if flammable gas is retained, it does not ignite.

Examples of the article include a small motor mounted on a movable part of an automobile. The motor is generally composed of an exterior member (cylindrical member) and a lid-like member. As the motor, specifically, a metal cylindrical member and a resin lid-like member having a shape corresponding to the cylindrical member are hermetically fixed in a fitted state. . The adhesive tape of this invention can be filled with the space | gap which may be formed between the said cylindrical member and the said lid-shaped member. Although there is a concern that electrostatic spark is generated by the rotation of the coil inside the cylinder, the motor can be used without igniting when the adhesive tape is used within the above range. Applications are not limited to motors.

(Preparation Example 1)
<Preparation of adhesive composition (a-1)>
Styrene-butadiene block copolymer having a weight average molecular weight of 300,000 (mixture of triblock copolymer and diblock copolymer. The proportion of the diblock copolymer to the total amount of the mixture is 50% by mass. -The mass proportion of polystyrene units in the entire butadiene block copolymer is 30 mass%, the mass proportion of polybutadiene units is 70 mass%), 100 mass parts, terpene phenol tackifying resin (softening point 115 ° C, molecular weight 1000) An adhesive composition (a-1) was obtained by dissolving 65 parts by mass in toluene.

(Preparation Example 2)
<Preparation of adhesive composition (a-2)>
In a reaction vessel equipped with a stirrer, reflux condenser, thermometer, dropping funnel and nitrogen gas inlet, 44.9 parts by mass of butyl acrylate, 50 parts by mass of 2-ethylhexyl acrylate, 2 parts by mass of acrylic acid, 3 parts by mass of vinyl acetate By dissolving 0.1 part by mass of 4-hydroxybutyl acrylate and 0.1 part by mass of 2,2′-azobisisobutylnitrile as a polymerization initiator in 100 parts by mass of ethyl acetate and polymerizing at 70 ° C. for 10 hours. An acrylic copolymer W solution having a weight average molecular weight of 800,000 was obtained.

  Next, 30 parts by mass of polymerized rosin ester-based tackifier resin D-135 (manufactured by Arakawa Chemical Co., Ltd.) is added to 100 parts by mass of acrylic copolymer W, and ethyl acetate is added and mixed. An adhesive composition (a-2) having a nonvolatile content of 45 mass was obtained.

(Preparation Example 3)
<Preparation of adhesive plastic material (a-3)>
Epiklone N-680 (a cresol novolac type epoxy resin solution manufactured by DIC Corporation, epoxy equivalent 215 g / eq, 75% by mass of nonvolatile content) 21.4 parts by mass, “YL-7862” (an epoxy resin manufactured by Mitsubishi Chemical Corporation) The epoxy resin composition Y having a nonvolatile content of 40% by mass was obtained by mixing 48 parts by mass with an epoxy equivalent of 3748 g / eq and a nonvolatile content of 50% by mass, and then mixing 30.6 parts by mass of methyl ethyl ketone.

<Preparation of adhesive tape>
Example 1
On the surface of a release paper having a thickness of 130 μm having a polyethylene layer on both sides of a fine paper and a silicone release agent layer on one side of the polyethylene layer, the adhesive composition (a-1) expands with respect to 100 parts by mass. A rod-shaped metal was prepared by mixing 5 parts by mass of F-36D (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., thermally expandable microcapsules, initial particle size 10 to 16 μm, expansion start temperature 70 to 80 ° C.) and stirring for 10 minutes. Coating was performed using an applicator so that the thickness after drying was 60 μm, and drying was performed for 10 minutes with a dryer set at 65 ° C., thereby producing a thermally expandable adhesive layer (A-1). The heat-expandable adhesive layer (A-1) is laminated on a release paper different from the above, and the top surface of the patch is reciprocated once by using a 2 kg hand roller, whereby the heat-expandable adhesive agent An adhesive tape comprising the layer (A-1) was obtained.

(Example 2)
The adhesive tape which consists of a thermally expansible adhesive layer (A-2) is the same method as Example 1 except having mixed 20 mass parts of swelling agents with respect to 100 mass parts of adhesive composition (a-1). Obtained.

Example 3
An adhesive tape comprising a thermally expandable adhesive layer (A-3) was prepared in the same manner as in Example 1 except that 50 parts by mass of an expansion agent was mixed with 100 parts by mass of the adhesive composition (a-1). Obtained.

(Example 4)
An adhesive tape comprising a thermally expandable adhesive layer (A-4) was prepared in the same manner as in Example 1 except that 100 parts by mass of an expanding agent was mixed with 100 parts by mass of the adhesive composition (a-1). Obtained.

(Example 5)
Adhesion comprising a thermally expandable adhesive layer (A-5) in the same manner as in Example 1 except that the adhesive composition (a-2) was used instead of the adhesive composition (a-1). I got a tape.

(Example 6)
Instead of the adhesive composition (a-1), the adhesive composition (a-3) is used, and EXPANSEL 051-40 (as an expanding agent with respect to 100 parts by mass of the adhesive composition (a-2)) Except that 5 parts by mass of Nippon Philite Co., Ltd., thermally expandable microcapsules, initial particle size of 12 μm, and expansion start temperature of 110 ° C. were mixed, the thermally expandable adhesive layer (A- An adhesive tape consisting of 6) was obtained.

(Comparative Example 1)
An adhesive tape comprising a thermally expandable adhesive layer (A-7) was prepared in the same manner as in Example 1 except that 200 parts by mass of an expansion agent was mixed with 100 parts by mass of the adhesive composition (a-1). Obtained.

(Comparative Example 2)
An adhesive tape comprising a thermally expandable adhesive layer (A-8) was prepared in the same manner as in Example 1 except that 1 part by mass of an expanding agent was mixed with 100 parts by mass of the adhesive composition (a-1). Obtained.

[Measurement method of shear adhesive strength]
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) were arranged in parallel with a gap of 12 mm, and adhered using an adhesive tape (50 μm). The spacer used was prepared such that the total thickness of the adhesive tape used for bonding to the spacer was 60 μm thick relative to the total thickness of each adhesive tape prepared in Examples 1 to 6 and Comparative Examples 1 and 2. did.

Next, an adhesive tape cut to a size of 10 mm × 10 mm is pasted on the upper surface (C1-1) side of the aluminum plate (C1) and between the two spacers, and a 2 kg hand roller is attached. Used for crimping.
Next, another aluminum plate (C2) (width 15 mm × length 70 mm × thickness 0.5 mm) having a degreased smooth surface was placed on the upper surface of the adhesive tape, and these were fixed with clips.

  The above fixed one was heated at 100 ° C. for 30 minutes, allowed to stand in a 23 ° C. environment for 30 minutes and then cooled, and then the clip was removed as a test piece.

  The adhesive strength of the adhesive tape was determined by chucking the end portions of the two aluminum plates of the test piece and performing a tensile test in a 180 degree direction at a tensile speed of 10 mm / min using a tensile tester. .

[Flammability evaluation method]
Put 6cm2 of the adhesive tape prepared in Examples 1-8 and Comparative Examples 1 and 2 into a glass container with a volume of 10cm3, cover the glass container with a lid, heat it at 150 ° C for 1 hour, and then release it to 25 ° C. Chilled. Thereafter, a hole was made in the lid of the glass container, and electrostatic spark was generated inside the glass container. At this time, the case where no ignition was observed was evaluated as “◯”, and the case where ignition was observed was evaluated as “×”.

  According to the said result, in Examples 1-6 of this invention, there was no ignition in evaluation of flammability, showing favorable shear adhesive force. On the other hand, in Comparative Example 1, the shear adhesive strength was inferior, and in Comparative Example 2, flammability was observed in the flammability evaluation.

1 Aluminum plate (C1)
2 Aluminum plate (C2)
3 Spacer 4 Adhesive tape 5 Gap between adhesive tape and aluminum plate (c2)

Claims (12)

An adhesive tape used in a substantially sealed space, the adhesive tape having a thermally expandable adhesive layer (A), and the thermally expandable adhesive layer (A) is an adhesive composition ( An adhesive tape comprising a) and a thermally expandable capsule, wherein the content of the thermally expandable capsule is 3 to 100 parts by mass with respect to 100 parts by mass of the total solid component of the adhesive composition (a). The adhesive tape according to claim 1, wherein the adhesive composition (a) contains a thermoplastic resin. The storage elastic modulus measured by a dynamic viscoelastic spectrum at 1 Hz in a range of 70 ° C to 120 ° C of the thermoplastic resin is in a range of 1.0 × 10 ² Pa to 1.0 × 10 ⁷ Pa. The adhesive tape according to 1 or 2. The adhesive tape according to any one of claims 1 to 3, wherein an expansion start temperature of the thermally expandable capsule is 50C to 150C. The adhesive tape according to any one of claims 1 to 4, wherein the thermally expandable adhesive layer (A) has an adhesive force of 0.5 N / 20 mm or more. The value obtained by dividing the sticking area (cm ² ) of the thermally expandable adhesive layer (A) of the adhesive tape by the volume (cm ³ ) of the substantially sealed space is 0.001 to 50. The adhesive tape of any one of -5. The expansion | swelling thing of the adhesive tape of any one of Claims 1-6 in which the space | gap which an to-be-adhered body (C1) has, or the space | gap between an to-be-adhered body (C1) and an to-be-adhered body (C2) is. Articles glued or filled through. The step [1] of applying the thermally expandable adhesive layer (A) of the adhesive tape according to any one of claims 1 to 6 to a part (c1-1) constituting the adherend (C1), Step [2] of heating the heat-expandable adhesive layer (A) at a temperature of 50 ° C. to 120 ° C., the heat-expandable adhesive layer (A) is expanded by the heating, and the heat-expandable adhesive layer ( Step [3] in which A1) is formed, and the other part where the thermally expandable adhesive layer (A1) or the adhesive layer (B) constituting the adhesive tape constitutes the adherend (C1) (C1-2) or other adherend (C2) having a step [4] affixed to the adherend (C1) or the adherend (C1) and the adherend The thing by which the space | gap between adhering bodies (C2) was adhere | attached or filled through the expanded material of the adhesive tape of any one of Claims 1-6 The method of production. The thermally expandable adhesive layer (A) of the adhesive tape according to any one of claims 1 to 6, wherein the step [1] forms a part (c1-1) constituting the adherend (C1). The manufacturing method of the articles | goods of Claim 8 including the process crimped | bonded by the force of 0.1 N / cm < ² > or more. In the step [4], the heat-expandable adhesive layer (A1) or the adhesive layer (B) and the adherend (by the force generated by expanding the heat-expandable adhesive layer (A)) and the adherend ( The method for producing an article according to claim 8 or 9, comprising a step of pressure-bonding the other part (c1-2) or the other adherend (C2) constituting C1). The step [1] of applying the thermally expandable adhesive layer (A) of the adhesive tape according to any one of claims 1 to 6 to a part (c1-1) constituting the adherend (C1), Step [2] of heating the heat-expandable adhesive layer (A), Step of expanding the heat-expandable adhesive layer (A) by the heating and forming a heat-expandable adhesive layer (A1) [ 3] and the adhesive layer (B) constituting the adhesive tape is affixed to the other part (c1-2) or the other adherend (C2) constituting the adherend (C1). A method for filling a gap in the adherend (C1) or a gap between the adherend (C1) and the adherend (C2), comprising the step [4]. The space | gap which the to-be-adhered body (C1) of Claim 11 which has the value which remove | divided the application area (cm < ² >) of the said adhesive tape by the volume (cm < ³ >) of the sealed space is 0.001-50 cm < ^-1 >, Or the filling method of the space | gap between an adherend (C1) and an adherend (C2).

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