JP2016027081A - Adhesive tape and method for disassembling electronic apparatus and article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive tape that has extremely superior adhesive strength in a temperature range of 60°C and below and drastically decreases its adhesive strength by application of heat in a short time.SOLUTION: An adhesive tape having a rubber-based adhesive layer is provided, which has such characteristics that: a storage modulus Gat 120°C of an adhesive component included in the adhesive layer is 1.0×10Pa to 2.0×10Pa; a ratio [G/G] of a storage modulus Gat 23°C to the storage modulus G120 is 1 to 20; and the adhesive tape is to be used for adhering two or more adherends, and upon separating the two or more adherends adhered, the tape is heated by use of a halogen lamp.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an adhesive tape that can be used for fixing two or more members constituting an electronic device, for example, and that can reduce the adhesive force by heating with a halogen lamp and separate the members. is there.

  Adhesive tapes are being considered for use in various electronic device manufacturing situations, such as copiers and multifunction machines having a copy function and a scan function.

  The pressure-sensitive adhesive tape is, for example, a double-sided adhesive tape in which a pressure-sensitive adhesive layer is formed on both sides of a non-woven fabric substrate, the interlayer fracture area ratio of the double-sided adhesive tape is 10% or less, and the tensile strength of the double-sided adhesive tape A double-sided adhesive tape is known in which both the MD direction (longitudinal direction) and the TD direction (lateral direction) are 20 N / 10 mm or more (see, for example, Patent Document 1).

  On the other hand, when the electronic device is used up and discarded, the electronic device is often dismantled manually, and components constituting the electronic device are classified by material and discarded or recycled. Specifically, in the case of the above-mentioned copying machine or multi-function machine, the transparent top plate constituting the copier and the casing may be manually disassembled, classified according to material, and discarded or recycled. Many.

  However, the transparent top plate is assumed to be repeatedly loaded with a paper medium such as a document, an image, and a book on its surface, and is firmly bonded to the casing, so that they can be easily handled manually. There was a case that could not be dismantled.

  In view of this, in the field of dismantling the electronic device, a method of cutting a part of the transparent top plate using a cutting machine or the like instead of manually dismantling the transparent top plate and the case has been studied.

  However, the cutting operation often takes a long time and is not preferred because it lowers the dismantling efficiency. Further, since a part of the transparent top plate is still adhered to a part of the case, it cannot be separated and disposed of, and the disposal process may be very expensive. .

  Thus, two or more adherends can be firmly bonded in a temperature range of 60 ° C. or lower, particularly in a room temperature range of about 20 ° C. to 60 ° C., and abruptly heated by heating for a short time. Therefore, it has been demanded to develop a pressure-sensitive adhesive tape capable of reducing the adhesive force and separating two or more adherends adhered to each other.

JP 2001-152111 A

  The problem to be solved by the present invention is to provide a pressure-sensitive adhesive tape that has a very excellent adhesive force under a temperature range of 60 ° C. or lower and that rapidly reduces the adhesive force by heating for a short time. It is.

The present invention is an adhesive tape having an adhesive layer (A) containing a rubber-based block copolymer (a), wherein the adhesive component contained in the adhesive layer (A) operates at 1 Hz and 120 ° C. Storage elastic modulus G ₁₂₀ measured by dynamic viscoelastic spectrum is in the range of 1.0 × 10 ³ Pa to 2.0 × 10 ⁵ Pa, and dynamics at 1 Hz and 23 ° C. with respect to the storage elastic modulus G ₁₂₀ The ratio [G ₂₃ / G ₁₂₀ ] of the storage elastic modulus G ₂₃ measured by the viscoelastic spectrum is 1 to 20, is used for bonding two or more adherends, and the two or more bonded substrates are bonded. The present invention relates to an adhesive tape which is heated using a halogen lamp when separating the adherend.

  The pressure-sensitive adhesive tape of the present invention is limited to a narrow range in which the pressure-sensitive adhesive tape can be applied (applied part), so even if it is necessary to use a thin pressure-sensitive adhesive tape, it is 60 ° C. or less, particularly 20 ° C. The adhesive strength of the level which can fully fix two or more to-be-adhered bodies in the temperature range of about -60 degreeC is provided.

  On the other hand, the pressure-sensitive adhesive tape of the present invention can have its adhesive strength rapidly reduced by heating to approximately 120 ° C., and as a result, has a characteristic that two or more adherends can be easily separated.

It is a conceptual diagram which shows the measuring method of surface adhesive strength. It is a conceptual diagram which shows the disassembling evaluation method.

The pressure-sensitive adhesive tape of the present invention is a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer (A) containing a rubber-based block copolymer (a), and includes 1 Hz and 120 ° C. of the pressure-sensitive adhesive component contained in the pressure-sensitive adhesive layer (A). in the range of the storage modulus _{G 120} is ^{1.0 × 10 3 Pa~2.0 × 10 5} Pa as measured by dynamic viscoelasticity spectrum at, relative to the storage elastic modulus _{G 120,} at 1Hz and 23 ° C. The ratio [G ₂₃ / G ₁₂₀ ] of the storage elastic modulus G ₂₃ measured by the dynamic viscoelastic spectrum is 1 to 20, and is used for bonding two or more adherends, and the bonded 2 When the above adherend is separated, it is heated using a halogen lamp.

  The pressure-sensitive adhesive tape of the present invention includes a so-called base-less pressure-sensitive adhesive tape constituted by a single layer or a laminated pressure-sensitive adhesive layer (A), the pressure-sensitive adhesive directly on one side or both sides of the base, or through another layer. An adhesive tape having the agent layer (A) can be used. As the pressure-sensitive adhesive tape, it is preferable to use a pressure-sensitive adhesive tape having the pressure-sensitive adhesive layer (A) on both sides of the substrate directly or via another layer.

  The pressure-sensitive adhesive layer (A) constituting the pressure-sensitive adhesive tape of the present invention includes a rubber-based block copolymer (a) capable of imparting so-called pressure-sensitive adhesiveness, and a pressure-sensitive adhesive component of a tackifying resin that can be used as necessary, and , Containing other additives that can be used as required.

As the said adhesive component contained in the pressure-sensitive adhesive layer (A), the storage modulus _{G 120} at 120 ° C. at a frequency 1Hz uses what is ^{1.0 × 10 3 ~2.0 × 10 5} Pa. By using a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer (A) containing a pressure-sensitive adhesive component having a storage elastic modulus G ₁₂₀ in the above range, a very excellent adhesive force can be expressed under a temperature range of 60 ° C. or lower, Even when heated for a short time using a relatively simple heating device such as a halogen lamp, the adhesive force can be remarkably reduced, and as a result, it is easy to separate two or more adherends adhered to each other. Can be done.

As the adhesive component, it is more preferable to use one having a storage elastic modulus G ₁₂₀ of 1.0 × 10 ³ Pa or more and 1.8 × 10 ⁵ Pa or less, and 5.0 × 10 ³ Pa or more and 1. The use of a material having a pressure of 6 × 10 ⁵ Pa or less can exhibit even better adhesive force in a temperature range of 60 ° C. or less, and can be used for a short time using a relatively simple heating device such as a halogen lamp. Further, it is more preferable to obtain a pressure-sensitive adhesive tape capable of remarkably reducing the adhesive force even when heated and separating two or more adherends adhered.

As the pressure-sensitive adhesive component contained in the pressure-sensitive adhesive layer (A), one having a storage elastic modulus G ′ at a frequency of 1 Hz and a storage elastic modulus G ′ at 23 ° C. of 1.0 × 10 ⁴ Pa or more is preferably 5.0 × 10 ^4. It is more preferable to use one having Pa of 2.0 × 10 ⁶ Pa or less, and using 8.0 × 10 ⁵ or more and 1.5 × 10 ⁶ Pa or less of the adhesive tape is applied. Even if it is a member limited to a very narrow area (applying part) and a narrow adhesive tape is unavoidable, it provides an adhesive force that can sufficiently fix the member. It is more preferable because

Further, as the adhesive component contained in the pressure-sensitive adhesive layer (A), the ratio of storage modulus _{G 23} as measured by dynamic viscoelasticity spectrum at 1Hz and 23 ° C. for the storage elastic modulus _{G 120 [G 23} / G ₁₂₀ ] is 1-20. By using a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer (A) containing a pressure-sensitive adhesive component in the range [G ₂₃ / G ₁₂₀ ], a very excellent adhesive force can be expressed in a temperature range of 60 ° C. or lower. In addition, a relatively simple heating device such as a halogen lamp is used, and when it is heated for a short time, its adhesive strength is remarkably reduced, and two or more adherends adhered can be separated, which is further preferable. .

The ratio [G ₂₃ / G ₁₂₀ ] is preferably in the range of 1-20, more preferably in the range of 1-18, and in the range of 1-15, the temperature range of 60 ° C. or less. Below, it can exhibit very good adhesive strength, and it uses a relatively simple heating device such as a halogen lamp to significantly reduce the adhesive strength when heated for a short period of time. It is more preferable because the adherend can be separated.

  Further, as the pressure-sensitive adhesive layer (A), it is possible to use a material that softens or melts when heated using a halogen lamp, and uses a relatively simple heating device such as a halogen lamp for heating in a short time. In this case, the adhesive strength is remarkably lowered, and it is preferable for separating two or more adherends adhered to each other. The pressure-sensitive adhesive layer (A) can rapidly soften or melt when heated to a temperature exceeding the glass transition temperature of the rubber-based block copolymer (a) contained in the pressure-sensitive adhesive layer (A). It is preferable.

  The pressure-sensitive adhesive layer (A) can significantly reduce the adhesive force at a relatively low temperature, and can cause separation of two or more adherends adhered to each other, compared to the case where a heating device other than a halogen lamp is used. . For this reason, when separating the two or more adherends, it is difficult to cause deformation, discoloration, failure or the like of the adherend due to the influence of heat. Specifically, the pressure-sensitive adhesive layer (A) is preferably heated to a range of 80 ° C. to 130 ° C. when the two or more adherends are separated, and is heated to 80 ° C. to 125 ° C. More preferably, it is more preferable to be heated to 90 ° C to 120 ° C. The heating is preferably performed for 3 seconds to 20 seconds, and more preferably performed for a relatively short time of 3 seconds to 15 seconds.

  In addition, the halogen lamp is normally heated to the suitable temperature range (for example, 80 ° C. to 130 ° C.) immediately after the power is turned on, and can quickly heat the object with the radiant heat. . The pressure-sensitive adhesive layer (A) is easily softened or melted rapidly in the preferred temperature range, and therefore, when it is heated for a short time using a halogen lamp, its adhesive strength is remarkably reduced, and two or more adhered. It is easy to separate the adherend.

  As described above, the pressure-sensitive adhesive layer (A) contains a rubber-based block copolymer (a), a pressure-sensitive adhesive component such as a tackifier resin that can be used as necessary, and other additives as necessary. It is a layer to do.

  Examples of the rubber block copolymer (a) include so-called ABA type block copolymers (triblock copolymers), AB type block copolymers (diblock copolymers), and mixtures thereof. Can be used.

  As the rubber-based block copolymer (a), it is possible to use a mixture of the triblock copolymer and the diblock copolymer, the storage elastic modulus at 23 ° C. and the storage elastic modulus at 120 ° C., It has a value obtained by dividing the storage elastic modulus at 23 ° C. by the storage elastic modulus measured at 120 ° C., and as a result, can exhibit a very high adhesive force in a normal temperature region of about 23 ° C., and It is preferable for obtaining a pressure-sensitive adhesive tape capable of reducing the adhesive strength to such an extent that two or more adherends can be easily separated by heating to 120 ° C., and the diblock copolymer is preferably used for the rubber-based block copolymer. It is more preferable to use what is contained in the range of 10% by mass to 90% by mass with respect to the whole polymer (a), and it is more preferable to use in the range of 15% by mass to 80% by mass It is especially preferred to use a range of 0 wt% to 75 wt%.

  As the pressure-sensitive adhesive tape of the present invention, it is preferable to use a tape having a peeling distance of 20 mm or less in a constant load holding force test measured at 23 ° C., and to use a tape having a thickness of 10 mm or less as the pressure-sensitive adhesive tape. Even in a state where a certain external adaptation force is applied, it is preferable because peeling hardly occurs.

  As the rubber block copolymer (a), a styrene block copolymer is preferably used. The styrenic block copolymer refers to a triblock copolymer, a diblock copolymer, or a mixture thereof having a polystyrene unit (a1) and a polyolefin unit.

  The polystyrene unit (a1) increases the elastic modulus of the pressure-sensitive adhesive layer (A), can exhibit a very excellent adhesive force in a temperature range of 60 ° C. or lower, and is heated for a short time using a halogen lamp. In some cases, this contributes to the characteristics that can significantly reduce the adhesive strength.

  Examples of the styrenic block copolymer include polystyrene-poly (isopropylene) block copolymer, polystyrene-poly (isopropylene) block-polystyrene copolymer, polystyrene-poly (butadiene) block copolymer, polystyrene. -Poly (butadiene) block-polystyrene copolymer, polystyrene-poly (butadiene / butylene) block copolymer, polystyrene-poly (butadiene / butylene) block-polystyrene copolymer, polystyrene-poly (ethylene / propylene) block copolymer Polymer, polystyrene-poly (ethylene / propylene) block-polystyrene copolymer, polystyrene-poly (ethylene / butylene) block copolymer, polystyrene-poly (ethylene / butylene) block-polis Ren copolymer, polystyrene - poly (ethylene - ethylene / propylene) block copolymer, polystyrene - poly (ethylene - ethylene / propylene) block - can be used polystyrene copolymer. Among these, as the styrenic block copolymer, it is preferable to use a block copolymer having a polystyrene unit (a1) and a polyisoprene unit (a2), and a polystyrene-poly (isopropylene) block copolymer. The use of coalescence, polystyrene-poly (butadiene) block copolymer, polystyrene-poly (butadiene) block-polystyrene copolymer can exhibit very good adhesive force under a temperature range of 60 ° C. or lower. Thermally decomposable adhesive that can use a relatively simple heating device such as a halogen lamp to significantly reduce the adhesive strength when heated for a short time and separate two or more adhered adherends. It is further preferable for obtaining a tape.

  As the rubber-based block copolymer (a), a rubber having a weight average molecular weight in the range of 10,000 to 800,000 is used in order to further improve the excellent adhesive force and the disassembling property by heating. It is more preferable to use those having a weight average molecular weight in the range of 50,000 to 500,000, and it is more preferable to use those having a weight average molecular weight in the range of 150,000 to 450,000.

  As said adhesive layer (A), it is preferable to use what contains tackifying resin etc. as needed as an adhesive component other than the said rubber-type block copolymer (a).

  Examples of the tackifying resin include a rosin tackifying resin, a polymerized rosin tackifying resin, a polymerized rosin ester tackifying resin, a rosin phenol tackifying resin, a hydrogenated rosin ester tackifying resin, and a disproportionated rosin ester. System-based tackifier resins, terpene-based tackifier resins, terpene-phenol-based tackifier resins, aliphatic (petroleum resin) -based tackifier resins, and C5-based petroleum-based tackifier resins can be used.

  Among these, as the tackifier resin, it is preferable to use a C5 petroleum-based tackifier resin or a terpene phenol-based tackifier resin in order to improve the wettability to the adherend surface. In particular, the terpene phenol-based tackifying resin can impart appropriate flexibility to the pressure-sensitive adhesive layer (A), can impart very high adhesive force in a temperature range of about 20 ° C to 60 ° C, and has a certain repulsive force. It is particularly preferable to use it for obtaining a heat-decomposable pressure-sensitive adhesive tape that can prevent peeling over time when added to the tape.

  As the C5 tackifying resin, a resin obtained by polymerizing the residue obtained by extracting and separating isoprene and cyclopentadiene from a C5 fraction generally obtained by decomposition of naphtha can be used.

  As the terpene phenol-based tackifier resin, a resin obtained by copolymerizing a terpene monomer and phenol can be used. As the terpene phenol-based tackifying resin, use of a resin having a softening point in the range of 105 ° C. to 145 ° C. improves compatibility with the rubber-based block copolymer (a), and as a result, 60 ° C. Preferable for obtaining a pressure-sensitive adhesive tape that can give a very high adhesive force under the following temperature range and has a peeling resistance capable of preventing a peeling over time when a certain repulsive force is applied to the tape. .

  The tackifier resin is preferably used in a range of 10 parts by mass to 150 parts by mass with respect to 100 parts by mass of the rubber-based block copolymer (a), and is used in a range of 15 parts by mass to 100 parts by mass. It is more preferable.

  In particular, the terpene phenol-based tackifying resin is preferably used in the range of 50 to 100 parts by mass with respect to 100 parts by mass of the rubber-based block copolymer (a), and 65 to 80 parts by mass. Use within the range can provide very high adhesive force in a temperature range of 60 ° C. or less, and it has a peel resistance that can prevent peeling over time when a certain repulsive force is applied to the tape. It is preferable when obtaining the heat decomposable pressure-sensitive adhesive tape provided. Moreover, it is preferable to use the said C5 type tackifying resin in the range of 10 mass parts-100 mass parts with respect to 100 mass parts of said rubber-type block copolymers (a), 20 mass parts-50 mass parts. It is more preferable to use in a range, and it is still more preferable to use in the range of 25 mass parts-50 mass parts.

  Further, as the tackifying resin, in addition to those described above, a tackifying resin that is liquid at room temperature can also be used. Examples of the liquid tackifying resin include low molecular weight liquid rubbers such as process oil, polyester-based tackifying resin, and polybutene.

  The pressure-sensitive adhesive layer (A) includes, in addition to the pressure-sensitive adhesive component, an infrared absorber, an antioxidant, an ultraviolet absorber, a filler, a fiber made of glass or plastic, a thermally expandable balloon, What contains fillers, such as a bead and metal powder, a pigment, a thickener, etc. can be used.

  In particular, the infrared absorbent can improve the rate at which the pressure-sensitive adhesive tape is heated when the pressure-sensitive adhesive tape of the present invention is heated using a halogen lamp, and the adhesive force can be reduced with a shorter heating time. It is preferable to use it because it is possible to reduce the separation of the two or more adherends adhered to each other.

  As the infrared absorber, known pigments such as inorganic pigments such as carbon black and composite oxide pigments; organic pigments such as phthalocyanine pigments, lake pigments, polycyclic pigments, and various dyes can be appropriately used.

  The infrared absorber is preferably included in the range of 0.01% by mass to 20% by mass with respect to the total amount of the pressure-sensitive adhesive layer (A).

  Further, the heat-expandable balloon is suitable for heating the pressure-sensitive adhesive tape of the present invention and separating two or more adherends adhered to each other with a weaker force. Can be used for

  Examples of the thermally expandable balloon include “Matsumoto Microsphere” (trade name, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.), “Microsphere Expandel” (trade name, manufactured by Nippon Philite Co., Ltd.), “Dai” Commercial products such as “form” (trade name, manufactured by Dainichi Seika Kogyo Co., Ltd.) can be used.

  The heat-expandable balloon obtains a pressure-sensitive adhesive tape that can separate two or more adherends that are adhered with a weaker force by heating while maintaining an excellent adhesive force in a temperature range of 60 ° C. or lower. In addition, it is preferably used in the range of 3% by mass to 50% by mass with respect to the mass of the adhesive component contained in the adhesive layer (A), and used in the range of 5% by mass to 30% by mass. It is more preferable to use in the range of 10% by mass to 20% by mass.

  As the pressure-sensitive adhesive tape, for example, it is preferable to use a pressure-sensitive adhesive layer (A) provided on one side of the base material having a thickness of 25 μm or more, and one having a thickness of 60 μm to 120 μm is used. It is more preferable to use a material having a thickness of 80 μm to 120 μm, which is excellent in cohesive force, can exhibit very excellent adhesive force in a temperature range of 60 ° C. or lower, and is relatively simple heating such as a halogen lamp. It is more preferable to obtain a pressure-sensitive adhesive tape that can reduce the adhesive strength when heated using an apparatus for a short time and can separate two or more adherends that have been bonded.

  As the pressure-sensitive adhesive tape, for example, it is preferable to use one having a total thickness of the pressure-sensitive adhesive layer (A) provided on both sides of the base material of 50 μm or more, and is in a range of 50 μm to 300 μm. Is more preferable, it is more preferable that it is in the range of 100 μm to 250 μm, and that it is in the range of 100 μm to 210 μm is excellent in cohesive force, and can exhibit very excellent adhesive force in a temperature range of 60 ° C. or lower, It is more preferable to obtain a pressure-sensitive adhesive tape that can separate two or more adherends adhered by heating with a weaker force.

  As described above, as the pressure-sensitive adhesive tape of the present invention, a pressure-sensitive adhesive tape having the pressure-sensitive adhesive layer (A) can be used on one side or both sides of the substrate directly or via another layer.

  As said base material, a nonwoven fabric base material, a resin film base material, etc. can be used, for example. Especially, as said base material, it is preferable to use the base material (infrared absorptive base material) which is excellent in the absorptivity of infrared rays.

  Examples of the infrared absorbing substrate include a resin film substrate containing an infrared absorbing inorganic filler, an organic dye, an inorganic dye, a dye, and a pigment, and a substrate provided with an infrared absorbing layer on a resin film.

  In particular, as the infrared absorbing base material, the use of a black base material gives a suitable endothermic property or heat storage property to the adhesive tape, and is a case where it is heated using a relatively simple halogen lamp. However, since the temperature of the adhesive tape can be increased in a short time to such an extent that separation of the two or more adherends occurs, the irradiation time can be shortened. This is preferable because the working efficiency of the step of separating two or more adherends can be significantly improved.

  On the other hand, when the adhesive tape obtained using the black base material is irradiated by using a local heating device such as a semiconductor laser, if the output is not strictly controlled, only the base material is heated. There is a possibility that separation of the two or more adherends cannot be sufficiently caused, or only the base material becomes high temperature and causes deformation or the like. Thus, the adhesive tape obtained using the black base material is preferably used in combination with a heating method using a halogen lamp.

  The black base material is not particularly limited as long as it is black. For example, a black base layer printed on a resin base material, a resin and black pigment kneaded into a film, a non-woven base material And the like in which black pigment is dispersed.

  As the substrate, it is preferable to use a substrate having a thickness of 4 μm to 100 μm, and using a substrate having a thickness of 10 μm to 75 μm is preferable for excellent workability of the adhesive tape and excellent adherend. It is more preferable in order to provide the following capability.

  A polyethylene terephthalate substrate or the like can be used as the resin film substrate. Moreover, as the said resin film base material, in order to improve the anchoring property of the said adhesive layer (A), what gave the corona treatment and the anchor coat process can be used.

  The pressure-sensitive adhesive tape of the present invention is obtained by, for example, applying and drying a pressure-sensitive adhesive containing the rubber-based block copolymer (a) on one or both surfaces of the base material using a roll coater or a die coater. It can manufacture by forming a layer (A).

  The pressure-sensitive adhesive tape is prepared by previously applying a pressure-sensitive adhesive containing the rubber-based block copolymer (a) on the surface of a release liner using a roll coater and drying the pressure-sensitive adhesive layer. (A) can be formed, and then the pressure-sensitive adhesive layer (A) can be produced by a transfer method in which the substrate is bonded to one side or both sides.

  The pressure-sensitive adhesive tape of the present invention exhibits a very excellent adhesive force, for example, in a temperature range of 60 ° C. or lower. Therefore, the said adhesive tape can be used conveniently for adhesion | attachment of various to-be-adhered bodies.

  The pressure-sensitive adhesive tape preferably has an adhesive strength of about 15 N / 20 mm to 40 N / 20 mm, for example, at a normal temperature (23 ° C.) environment, by peeling off 180 ° from the stainless steel plate. It is more preferable to have an adhesive strength of about 40 N / 20 mm in order to firmly adhere the adherend and prevent peeling over time.

  As a method for producing an article by adhering two or more adherends using the adhesive tape, for example, one adhesive layer (A) constituting the adhesive tape is formed on the surface of any one adherend. After pasting, the article can be manufactured by sticking the other adherend to the surface of the other pressure-sensitive adhesive layer (A) and pressing them as necessary.

  On the other hand, as a method of disassembling the article, for example, a halogen lamp is brought close to or in contact with the adhesive tape or the adherend constituting the article, and the adhesive tape is heated directly or indirectly to bond the article. In addition, there is a method of disassembling the article by separating two or more adherends.

  During the heating, a halogen lamp may be brought close to or in contact with the pressure-sensitive adhesive tape, or the pressure-sensitive adhesive tape may be indirectly heated by bringing a halogen lamp close to or in contact with the adherend. For example, when the end portion of the adhesive tape protrudes outside the end portion of the adherend, a halogen lamp may approach or contact the end portion of the adhesive tape.

  In the heating step, using a heating device equipped with a halogen lamp, it is preferable to heat the pressure-sensitive adhesive tape to a temperature of 80 ° C to 130 ° C, more preferably to 85 ° C to 125 ° C, More preferably, heating is performed until the temperature reaches 90 ° C to 120 ° C. The heating is preferably within 20 seconds, more preferably within 15 seconds, and further preferably within a relatively short period of time within 10 seconds.

  Specifically, the heating step using the halogen lamp is a step of setting the temperature of the pressure-sensitive adhesive tape to 100 ° C. within 20 seconds, so that the disassembly efficiency of the article can be improved and the heat of the adherend This is preferable because deformation can be prevented.

  In addition, as a heating device equipped with a halogen lamp, for example, a “parallel light type halogen lamp heater” capable of heating a certain area in a short time, a condensing halogen type lamp capable of local heating, or the like may be used. In addition, the use of a parallel light type halogen lamp heater can heat a wide range at a time, so that the heating time can be shortened to the time described above.

Area heatable in the parallel light type halogen lamp heater ^once, preferably a 10cm ² ~500cm 2 about. Moreover, it is preferable that the heating device such as a parallel light type halogen lamp heater has a portable size and weight in order to improve the efficiency of the work for disassembling the article. The weight is preferably 3 kg or less, preferably 2 kg or less, and more preferably 0.1 kg to 1 kg.

  The article heated by the above method can be easily disassembled by applying little or no force to two or more adherends constituting the article. Since there is almost no adhesive residue derived from the adhesive tape on the surface of the adherend, the adherend can be used for recycling or the like.

  Since the pressure-sensitive adhesive tape of the present invention has a very excellent adhesive force in a temperature range of 60 ° C. or lower, for example, a transparent top plate constituting an electronic device such as a copying machine or a multi-function machine having a copy function or a scan function; It can be used for fixing to the case.

  As the transparent top plate, it is possible to use a transparent top plate installed in a copying machine or a multifunction peripheral equipped with a general copy function or scan function.

  As the transparent top plate, for example, a transparent plate-like rigid body made of glass or plastic can be used. As said plastic, an acrylic board, a polycarbonate board, etc. can be used, for example.

  As the transparent top plate, those suitable for the shape of the copying machine or the like on which it is installed can be used, but it is usually preferable to use a square or rectangular one.

  If the adhesive tape is, for example, a rectangular transparent top plate, it is preferable that the adhesive tape is attached along two opposing end portions. At this time, the adhesive tape can be cut into a cover corresponding to the length of the side of the transparent top plate. For example, the width is 0.5 mm to 20 mm and the length is 0.1 mm to 2 mm. It is preferable to use one that is 0 mm.

  Moreover, the adhesive tape of this invention can be used exclusively for fixing of the member which comprises a portable electronic device. Examples of the member include two or more casings or lens members constituting an electronic device.

  Examples of the portable electronic device include those having a structure in which a case and one of a lens member or other case are joined via the adhesive tape as the member.

  Examples of the fixing of the member include a method in which one of the casing or the lens member and the other casing or the lens member are laminated via the adhesive tape and then cured for a certain period.

  Examples will be described in detail below.

(Production Example 1)
Styrene-butadiene block copolymer S having a weight average molecular weight of 300,000 (a mixture of a triblock copolymer and a diblock copolymer. The ratio of the diblock copolymer to the total amount of the mixture is 20% by mass. The mass proportion of polystyrene units in the whole styrene-butadiene block copolymer is 20 mass%, the mass proportion of polybutadiene units is 80 mass%) 100 mass parts, C5 petroleum-based tackifying resin (softening point 100 ° C, number average molecular weight) 885) An adhesive (a-1) was obtained by dissolving 40 parts by mass in toluene.

The pressure-sensitive adhesive (a-1) was applied to the surface of the release liner using an applicator so that the thickness after drying was 100 μm, and dried at 85 ° C. for 5 minutes to form a pressure-sensitive adhesive layer. . The pressure-sensitive adhesive layer is bonded to both surfaces of a base material provided with a black ink layer having a thickness of 4 μm on both sides of a polyethylene terephthalate film having a thickness of 38 μm, and then pressure-bonded with 4 kgf / cm ² to laminate. 1 was produced.

  The adhesive tape 1 was cut into two strips having a length of 50 and a width of 5 mm. An adherend was prepared by sticking the cut adhesive tape to both ends of the long side of a transparent glass plate having a length of 50 mm, a width of 40 mm, and a thickness of 0.4 mm.

Next, the adhesive tape side of the adherend is approximately at the center of a polymer alloy resin plate made of white acrylonitrile / butadiene / styrene resin and polycarbonate resin, which is a rectangular parallelepiped having a length of 100 mm, a width of 100 mm and a thickness of 2 mm. Then, after pressurizing for 10 seconds at 80 N / cm ² using a press machine, the pressed state was released, and the article 1 was produced by allowing to stand in an environment of 85 ° C. for 24 hours.

(Production Example 2)
Instead of the polyethylene terephthalate film having the black ink layer used in Production Example 1, Foret GS-1000 (manufactured by Soken Chemical Co., Ltd., polymethyl methacrylate, 30% by mass solution) 600 parts by mass, infrared absorbing dye CIR-RL (Nippon Carlit Co., Ltd., diimonium salt compound) A coating solution containing 6.4 parts by mass, 400 parts by mass of methyl ethyl ketone and 400 parts by mass of toluene is applied to a polyethylene terephthalate film having a thickness of 38 μm and a thickness after drying to 4 μm. An adhesive tape 2 and an article 2 were produced in the same manner as in Production Example 1 except that a substrate having an infrared absorption layer obtained by coating and drying was used.

(Production Example 3)
The same method as in Preparation Example 1 except that a 38 μm thick polyethylene terephthalate film (PET film) having no black ink layer was used instead of the polyethylene terephthalate film having the black ink layer used in Preparation Example 1. Thus, an adhesive tape 3 and an article 3 were prepared.

(Production Example 4)
Instead of the pressure-sensitive adhesive (a-1), the pressure-sensitive adhesive (a-1) was mixed with 0.5 parts by mass of “carbon black” (infrared absorber) manufactured by Evonik Degussa Japan which is not a pressure-sensitive adhesive component. An adhesive tape 4 and an article 4 were produced in the same manner as in Production Example 3 except that the adhesive (a-2) was used.

(Production Example 5)
Instead of the styrene-butadiene block copolymer S, a styrene-butadiene block copolymer T having a weight average molecular weight of 300,000 (a mixture of a triblock copolymer and a diblock copolymer. The diblock relative to the total amount of the mixture). The copolymer accounted for 20% by mass, with the exception of using 15% by mass of polystyrene units and 85% by mass of polybutadiene units in the styrene-butadiene block copolymer. A pressure-sensitive adhesive tape 5 and an article 5 were produced in the same manner as in Example 3.

(Production Example 6)
In place of the styrene-butadiene block copolymer S, a styrene-butadiene block copolymer U having a weight average molecular weight of 320,000 (a mixture of a triblock copolymer and a diblock copolymer. The diblock relative to the total amount of the mixture). The proportion of the copolymer is 30% by mass, and the polystyrene unit is 20% by mass and the polybutadiene unit is 80% by mass. An adhesive tape 6 and an article 6 were produced in the same manner as in Example 3.

(Production Example 7)
Instead of the styrene-butadiene block copolymer S, a styrene-butadiene block copolymer V having a weight average molecular weight of 400,000 (a mixture of a triblock copolymer and a diblock copolymer. The diblock relative to the total amount of the mixture). The copolymer accounted for 15% by mass, except that the polystyrene unit mass ratio was 10% by mass and the polybutadiene unit mass ratio was 90% by mass). A pressure-sensitive adhesive tape 7 and an article 7 were produced in the same manner as in Example 3.

(Production Example 8)
An adhesive tape 8 and an article 8 are produced in the same manner as in Production Example 3 except that the amount of C5 petroleum-based tackifying resin (softening point 100 ° C., number average molecular weight 885) used is changed from 40 parts by mass to 20 parts by mass. did.

(Production Example 9)
Instead of the styrene-butadiene block copolymer S, a styrene-butadiene block copolymer X having a weight average molecular weight of 300,000 (a mixture of a triblock copolymer and a diblock copolymer. The diblock relative to the total amount of the mixture). The proportion of the copolymer is 50% by mass, the mass proportion of polystyrene units in the total of the styrene-butadiene block copolymer is 30% by mass, and the mass proportion of polybutadiene units is 70% by mass. A pressure-sensitive adhesive tape 9 and an article 9 were prepared in the same manner as in Preparation Example 1 except that 65 parts by mass of a terpene phenol-based tackifying resin (softening point 115 ° C., molecular weight 1000) was used instead of the C5 petroleum-based tackifying resin. .

(Production Example 10)
An adhesive tape 10 was prepared in the same manner as in Preparation Example 9 except that a 25 μm thick polyethylene terephthalate film kneaded with black pigment was used instead of the polyethylene terephthalate film having the black ink layer used in Preparation Example 9. And the article 10 was produced.

(Production Example 11)
The adhesive tape 11 and the adhesive tape 11 were prepared in the same manner as in Preparation Example 9 except that the amount of the terpene phenol-based tackifying resin (softening point 115 ° C., molecular weight 1000) used in Preparation Example 9 was changed from 65 parts by mass to 75 parts by mass. Article 11 was made.

(Production Example 12)
Instead of the pressure-sensitive adhesive used in Production Example 9, the pressure-sensitive adhesive used in Production Example 9 and Matsumoto Microsphere F-48 (Matsumoto Yushi Seiyaku Co., Ltd., having a thermal expansion coefficient of 370%, which is not an adhesive component) Example 9 except that an adhesive obtained by mixing an expansion start temperature of 90 ° C. to 100 ° C., a maximum expansion temperature of 125 ° C. to 135 ° C., and an average particle size (before expansion) of 9 μm to 15 μm) was used. A pressure-sensitive adhesive tape 12 and an article 12 were produced in the same manner. The Matsumoto Microsphere F-48 was used in an amount of 15 parts by mass with respect to the adhesive component (the total of the styrene-butadiene block copolymer W and the terpene phenol tackifying resin).

(Comparative Production Example 1)
Instead of the styrene-butadiene block copolymer S, a styrene-butadiene block copolymer W having a weight average molecular weight of 1,000,000 (a mixture of a triblock copolymer and a diblock copolymer. The diblock relative to the total amount of the mixture). The copolymer accounted for 20% by mass, except that the polystyrene unit was 30% by mass and the polybutadiene unit was 70% by mass). An adhesive tape 13 and an article 13 were produced in the same manner as in Example 1.

(Comparative Production Example 2)
(Preparation of pressure-sensitive adhesive (a-3))
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 X solution having a weight average molecular weight of 800,000 was obtained.

  Next, by adding 30 parts by mass of polymerized rosin ester-based tackifier resin D-135 (Arakawa Chemical Industries, Ltd.) to 100 parts by mass of acrylic copolymer X, adding ethyl acetate and mixing, An acrylic pressure-sensitive adhesive having a nonvolatile content of 45% by mass was obtained.

  1.1 parts by mass of “Coronate L-45” (isocyanate-based crosslinking agent, solid content: 45% by mass) manufactured by Nippon Polyurethane Industry Co., Ltd. was added to 100 parts by mass of the acrylic pressure-sensitive adhesive and stirred for 15 minutes. The acrylic pressure-sensitive adhesive layer is formed by applying the acrylic pressure-sensitive adhesive (a-3) on the separator using an applicator so that the thickness after drying becomes 100 μm and drying at 85 ° C. for 5 minutes. did.

Next, the acrylic pressure-sensitive adhesive layer was laminated on both sides of a 38 μm polyethylene terephthalate film having a 4 μm-thick black ink layer provided on the surface, and then pressure-bonded and laminated at 4 kgf / cm ^2. 14 was produced.

  An article 14 was produced in the same manner as in Production Example 1 except that the above adhesive tape was used instead of Production Example 1.

(Comparative Production Example 3)
A 38 μm thick polyethylene terephthalate film having no 4 μm thick black ink layer was used instead of the 38 μm thick polyethylene terephthalate film provided on the surface with the 4 μm thick black ink layer used in Comparative Preparation Example 2. Except for the above, an adhesive tape 15 and an article 15 were produced in the same manner as in Comparative Production Example 2.

(Comparative Production Example 4)
(Preparation of adhesive (a-4))
In a reaction vessel equipped with a stirrer, reflux condenser, thermometer, dropping funnel and nitrogen gas inlet, 100 parts by mass of the monomer combination of Table 1 and 2,2′-azobisisobutylnitrile as a polymerization initiator 0.2 mass Were dissolved in 100 parts by mass of ethyl acetate and polymerized at 80 ° C. for 8 hours to obtain an acrylic copolymer Y solution.

  Next, 10 parts by mass of rosin ester resin A-100 (Arakawa Chemical Industries, Ltd.) and polymerized rosin ester tackifier resin D-135 (Arakawa Chemical Industries, Ltd.) with respect to 100 parts by mass of the acrylic copolymer Y ) Was added in an amount of 20 parts by mass, and diluted with toluene to obtain a pressure-sensitive adhesive (a-4) having a nonvolatile content of 45% by mass.

  1.1 parts by mass of “Coronate L-45” (isocyanate-based crosslinking agent, solid content: 45% by mass) manufactured by Nippon Polyurethane Industry Co., Ltd. was added to 100 parts by mass of the pressure-sensitive adhesive (a-4) and stirred for 15 minutes. The pressure-sensitive adhesive layer was applied on a separator using an applicator so that the thickness after drying was 100 μm, and dried at 85 ° C. for 5 minutes to form an adhesive layer.

Next, the pressure-sensitive adhesive layer was bonded to both surfaces of a 38 μm polyethylene terephthalate film having a 4 μm thick black ink layer provided on the surface, and then the pressure-sensitive adhesive tape 16 was laminated by pressing at 4 kgf / cm ^2. Produced.

  An article 16 was produced in the same manner as in Production Example 1 except that the above-mentioned adhesive tape 16 was used instead of the adhesive tape 1.

Example 1
Three articles 1 obtained in Production Example 1 were prepared, and a parallel light type halogen lamp heater (manufactured by Heat Tech Co., Ltd., two halogen lamp tubes having a length of 10 cm was mounted in an environment of 23 ° C. and generated from the halogen lamp. Wavelength of light: gold infrared region 2 μm, rated voltage 100 V, rated power consumption 850 W, portable type, weight 0.7 kg, collective irradiation area about 200 cm ² ) to the distance from the glass plate constituting the article to 10 mm Set.

  Next, the three articles 1 were heated using the heater for 5 seconds, 10 seconds, and 15 seconds, respectively. The temperature of the adhesive tape when heated for 5 seconds is about 90 ° C., the temperature of the adhesive tape when heated for 10 seconds is about 105 ° C., and the temperature of the adhesive tape when heated for 15 seconds is about It was 120 ° C.

  After the heating, each article 1 was left at 23 ° C. for 5 seconds, and a force was applied with a finger in the shearing direction of the glass plate to separate the glass plate constituting the article 1 from the article.

(Example 2)
Heating and peeling were performed in the same manner as in Example 1 except that the product 2 obtained in Production Example 2 was used instead of the product 1.

(Example 3)
Heating and peeling were performed in the same manner as in Example 1 except that the product 3 obtained in Production Example 3 was used instead of the product 1.

Example 4
Heating and peeling were performed in the same manner as in Example 1 except that the product 4 obtained in Production Example 4 was used instead of the product 1.

(Example 5)
Heating and peeling were performed in the same manner as in Example 1 except that the product 5 obtained in Production Example 5 was used instead of the product 1.

(Example 6)
Heating and peeling were performed in the same manner as in Example 1 except that the product 6 obtained in Production Example 6 was used instead of the product 1.

(Example 7)
Heating and peeling were performed in the same manner as in Example 1 except that the product 7 obtained in Production Example 7 was used instead of the product 1.

(Example 8)
Heating and peeling were performed in the same manner as in Example 1 except that the product 8 obtained in Production Example 8 was used instead of the product 1.

Example 9
Heating and peeling were performed in the same manner as in Example 1 except that the product 9 obtained in Production Example 9 was used instead of the product 1.

(Example 10)
Heating and peeling were performed in the same manner as in Example 1 except that the article 10 obtained in Preparation Example 10 was used instead of the article 1.

(Example 11)
Heating and peeling were performed in the same manner as in Example 1 except that the product 11 obtained in Production Example 11 was used instead of the product 1.

(Example 12)
Heating and peeling were performed in the same manner as in Example 1 except that the article 12 obtained in Production Example 12 was used instead of the article 1.

(Comparative Example 1)
Heating and peeling were performed in the same manner as in Example 1 except that the article 13 obtained in Comparative Production Example 1 was used instead of the article 1.

(Comparative Example 2)
Heating and peeling were performed in the same manner as in Example 1 except that the article 14 obtained in Comparative Production Example 2 was used instead of the article 1.

(Comparative Example 3)
Heating and peeling were performed in the same manner as in Example 1 except that the product 15 obtained in Comparative Production Example 3 was used instead of the product 1.

(Comparative Example 4)
Heating and peeling were performed in the same manner as in Example 1 except that the product 16 obtained in Comparative Production Example 4 was used instead of the product 1.

(Comparative Example 5)
Parallel type halogen lamp heater used in Example 1 (Heattech, two halogen lamp tubes with a length of 10 cm are mounted, wavelength of light generated from the halogen lamp: gold infrared region 2 μm, rated voltage 100 V, rated power consumption Instead of 850 W, portable, weight 0.7 kg, collective irradiation area about 200 cm ² ), scan with semiconductor laser (output 4 W, wavelength 940 nm, weight 250 kg, collective irradiation area about 0.1 cm ² (local heating)) The article 1 was heated and peeled in the same manner as in Example 1 except that it was used at a speed of 500 mm / min.

(Comparative Example 6)
Parallel type halogen lamp heater used in Example 9 (Heattech Co., Ltd., equipped with two 10 cm long halogen lamp tubes, wavelength of light generated from halogen lamp: gold infrared region 2 μm, rated voltage 100 V, rated power consumption Instead of 850 W, portable, weight 0.7 kg, collective irradiation area about 200 cm ² ), scan with semiconductor laser (output 4 W, wavelength 940 nm, weight 250 kg, collective irradiation area about 0.1 cm ² (local heating)) The article 9 was heated and peeled off in the same manner as in Example 9 except that it was used at a speed of 500 mm / min.

(Comparative Example 7)
Parallel type halogen lamp heater used in Example 1 (Heattech, two halogen lamp tubes with a length of 10 cm are mounted, wavelength of light generated from the halogen lamp: gold infrared region 2 μm, rated voltage 100 V, rated power consumption 850 W, portable type, weight 0.7 kg, collective irradiation possible area about 200 cm ² ), except that a dryer set at 120 ° C. was used, and heating the article 1 in the same manner as in Example 1 Peeling was performed.

(Comparative Example 8)
Parallel type halogen lamp heater used in Example 9 (two heat lamp tubes made by Heat Tech Co., Ltd. are mounted, wavelength of light generated from the halogen lamp: gold infrared region 2 μm, rated voltage 100 V, rated consumption Heating the article 9 in the same manner as in Example 9 except that a dryer set at 120 ° C. was used instead of an electric power of 850 W, a portable type, a weight of 0.7 kg, and a collective irradiation area of about 200 cm ² ). And peeling off.

(Measurement of dynamic viscoelasticity of adhesive layer)
Thickness after drying the adhesive components (total of rubber-based block copolymer or acrylic copolymer and tackifying resin) used in the production of the adhesive tapes obtained in the production examples and comparative production examples using an applicator Was applied to the surface of the release liner so as to be 100 μm, and dried at 85 ° C. for 5 minutes to form a plurality of 100 μm-thick adhesive layers.

  Next, the test piece which consists of an adhesive layer with a thickness of 2 mm was each created by overlapping the adhesive layer obtained using the same adhesive.

A parallel plate having a diameter of 7.9 mm was attached to a viscoelasticity tester (ARES 2kSTD) manufactured by TA Instruments Japan. The test specimen is sandwiched between the parallel plates with a compressive load of 40 to 60 g, and a storage elastic modulus (23 ° C.) at a frequency of 1 Hz, a temperature range of −60 to 150 ° C., and a temperature increase rate of 2 ° C./min ( G ₂₃ ) and storage elastic modulus (G ₁₂₀ ) at 120 ° C. were measured.

[Ratio of storage elastic modulus (G ₂₃ ) at ₂₃ ° C. and storage elastic modulus (G ₁₂₀ ) at 120 ° C.]
The ratio of the storage elastic modulus (G ₂₃ ) at 23 ° C. to the storage elastic modulus (G ₁₂₀ ) at 120 ° C. measured by the above method was calculated.

[Adhesive strength evaluation method (surface adhesive strength)]
Under the environment of 23 ° C., the pressure-sensitive adhesive tapes obtained in the production example and the comparative production example were cut into a frame with a side of 14 mm and a width of 2 mm.

  The cut adhesive tape 2 was attached to a transparent acrylic plate 1 which is a rectangular parallelepiped having a length of 15 mm, a width of 15 mm and a thickness of 2 mm. At that time, a test piece 1 was prepared by attaching one side of the cut adhesive tape 2 so as to correspond to one side 15 mm of the acrylic plate 1.

Next, the 20 mm long, 50 mm wide, and 1 mm thick polycarbonate plate 3 having a hole with a diameter of 10 mm in the central portion and the adhesive tape side surface of the test piece 1 are pasted so that their centers coincide. Then, after pressurizing at 80 N / cm ² for 10 seconds using a press machine, the pressed state was released, and the specimen 2 was produced by allowing it to stand at 23 ° C. for 1 hour.

Next, a tensile tester (A & D Tensilon RTA-100, compression mode) equipped with a stainless steel probe 4 having a diameter of 8 mm was prepared. When the probe 4 applied a force to the test piece 1 constituting the test piece 2 through the hole of the SUS plate 3 constituting the test piece 2, the test piece 1 was peeled off from the polycarbonate plate 3. The strength (N / cm ² ) at the time was measured in a temperature environment of 23 ° C. and 120 ° C., respectively. The speed at which the probe 4 pushes the test piece 1 was set to 10 mm / min.

[Evaluation method of adhesive strength (180 degree peeling adhesive strength)]
180 degree peeling adhesion was measured according to JIS Z 0237. Specifically, the release liner on one side of the pressure-sensitive adhesive tapes obtained in Examples and Comparative Examples was peeled off, and the pressure-sensitive adhesive layer was lined with a polyethylene terephthalate film (PET film) having a thickness of 25 μm.

  The backed adhesive tape was cut into a width of 20 mm, the release liner on the other side was peeled off, and the adhesive layer was bonded to a transparent polycarbonate plate to make a test piece 3.

  The test piece 3 was allowed to stand in an environment of 23 ° C. and 50% RH for 30 minutes, and then a Tensilon tensile tester [manufactured by A & D Co., Ltd., model: RTM-100] in each of the temperature environments of 23 ° C. and 120 ° C. The adhesive strength when the double-sided pressure-sensitive adhesive tape constituting the test piece 3 was peeled from the polycarbonate plate at a speed of 300 mm / min in the direction of 180 degrees was measured.

[Evaluation method of constant load holding force]
One side of the adhesive tape was lined with a polyethylene terephthalate film having a thickness of 25 μm, and cut into a width of 10 mm and a length of 70 mm to prepare a test tape. A range of 50 mm in length of the test tape was affixed to a stainless steel plate, and reciprocated using a 2 kg roller to adhere them. The bonded material was left in an atmosphere of 23 ° C. and 50% RH for 1 hour, then a load of 300 g was applied in the direction of 90 ° with respect to the peeling direction, and left for 3 hours. The peel distance was measured and evaluated according to the following criteria. In addition, the above-described evaluation method of the constant load holding force is a substitute evaluation method assuming a case where a deformation stress is applied to the test tape from the outside for a long time, and indicates that the longer the peeling distance, the better the constant load holding force. The values in the table indicate the peeling distance (mm) after standing for 3 hours.

[Evaluation of thermal decomposability in a short time]
The ease of peeling when performing heating and peeling by the methods described in Examples and Comparative Examples was evaluated according to the following criteria.

  (Double-circle): The glass plate was able to be isolate | separated from the said articles | goods only by pushing in the glass plate which comprises articles | goods in the shear direction with one index finger.

  ○: When the glass plate constituting the article was pushed in with one thumb in the shear direction, the glass plate could be separated from the article.

  (Triangle | delta): The glass plate which was comprised from the said article | item was able to be isolate | separated by grasping the glass plate which comprises articles | goods by hand, and pulling with the force in the shear direction.

  X: Even if the glass plate constituting the article was grasped by hand and pulled in the shearing direction with full force, the glass plate could not be separated from the article, and the glass plate could not be moved at all.

[Portability of heating device]
The portability of the heating devices used in Examples and Comparative Examples was evaluated according to the following criteria.

○: The weight is less than 5.0 kg and can be carried with one hand. ×: The weight is 5.0 kg or more and cannot be carried with one hand.

DESCRIPTION OF SYMBOLS 1 Transparent acrylic board 2 Cut adhesive tape 3 Polycarbonate board 4 Probe 5 Transparent glass board 6 Cut adhesive tape 7 Polymer alloy resin board made of acrylonitrile / butadiene / styrene resin and polycarbonate resin

Claims (16)

A pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer (A) containing a rubber-based block copolymer (a), the dynamic viscoelastic spectrum at 1 Hz and 120 ° C. of the pressure-sensitive adhesive component contained in the pressure-sensitive adhesive layer (A) in a measured range of storage modulus _{G 120} is ^{1.0 × 10 3 Pa~2.0 × 10 5} Pa is, with respect to the storage elastic modulus _{G 120,} a dynamic viscoelasticity spectrum at 1Hz and 23 ° C. The ratio [G ₂₃ / G ₁₂₀ ] of the storage elastic modulus G ₂₃ to be measured is 1 to 20, and it is used for bonding two or more adherends, and the two or more adherends are separated. A pressure-sensitive adhesive tape that is heated using a halogen lamp when performing the process. The pressure-sensitive adhesive tape according to claim 1, wherein the pressure-sensitive adhesive component is the rubber-based block copolymer (a) and a tackifier resin. The pressure-sensitive adhesive tape according to claim 1 or 2, wherein the rubber-based block copolymer (a) is a block copolymer having a polystyrene unit (a1) and a polybutadiene unit (a2). The pressure-sensitive adhesive tape according to any one of claims 1 to 3, wherein the heating performed using the halogen lamp is heating performed using a parallel light halogen lamp heater. The pressure-sensitive adhesive layer according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer (A) is provided on both surfaces of the substrate, and the pressure-sensitive adhesive layer (A) has a thickness of 25 µm or more. tape. The pressure-sensitive adhesive tape according to claim 5, wherein the substrate is an infrared-absorbing substrate. The pressure-sensitive adhesive tape according to any one of claims 1 to 6, which is used for fixing the transparent top plate constituting the electronic apparatus and the casing. A method for disassembling an article having a configuration in which two or more adherends are bonded together by the adhesive tape according to any one of claims 1 to 7, wherein the halogen is applied to the adhesive tape or the adherend. A method for disassembling an article, wherein the two or more adherends are separated by approaching or contacting a lamp and heating the adhesive tape. The method for disassembling an article according to claim 8, wherein the heating step using the halogen lamp is a step of bringing the temperature of the adhesive tape to 100 ° C within 20 seconds. The article disassembling method according to claim 8 or 9, wherein the heating performed using the halogen lamp is heating performed using a parallel light halogen lamp heater. The electronic device with which the said transparent top plate was fixed to the housing with the adhesive tape of any one of Claims 1-7. The electronic apparatus according to claim 11, wherein the transparent top plate is fixed to a front surface of an image or document reading unit. The said transparent top plate is heated by making the said halogen lamp approach or contact the said adhesive tape which comprises the electronic device of Claim 11 or 12, or the said transparent top plate, or the said case, and heating the said adhesive tape. A method for disassembling an electronic device characterized by separating the body. The method for disassembling an electronic device according to claim 13, wherein the heating step using the halogen lamp is a step of setting the temperature of the adhesive tape to 100 ° C. within 20 seconds. The portable electronic terminal with which the housing | casing and the lens member or the other housing were fixed with the adhesive tape of any one of Claims 1-7. The adhesive lamp or the casing or the lens member constituting the portable electronic terminal according to claim 15, wherein the halogen lamp is brought close to or in contact with the lens member, and the adhesive tape is heated to separate them. A method for dismantling a portable electronic terminal.

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