JP6601459B2 - Double-sided adhesive tape - Google Patents

Description

  The present invention relates to an adhesive tape.

  Adhesive tapes are widely used in situations such as fixing parts constituting electronic devices. Specifically, the adhesive tape is used for fixing sheet metals and exterior parts and casings of relatively large electronic devices such as flat-screen TVs, home appliances, and OA devices, and portable electronic terminals, cameras, and personal computers. It is used for fixing exterior parts and rigid parts such as batteries to relatively small electronic devices. These rigid parts may have uneven shapes and distortions, and the pressure-sensitive adhesive tape is required to have a follow-up property that develops a strong adhesive force while following these surface shapes.

  Also, in the field of office automation equipment such as flat-screen TVs, home appliances, printers and copiers, reusable parts used in products are disassembled after use for the purpose of resource conservation from the viewpoint of environmental harmony. Reuse is increasing. At this time, if an adhesive tape is used, it may be necessary to peel off the adhesive tape attached to the part. There was a problem that it was cut or the double-sided adhesive tape was broken between the nonwoven fabric layers. In addition, after use in a high temperature or high humidity environment, the adhesive tape is sufficiently adhered to the adherend, so that it may be very difficult to peel again.

  In addition, when hard materials such as metal and plastic are firmly bonded using conventional adhesive tape, it is necessary to heat and soften the adhesive component, etc., but in this case In such a case, the metal or plastic of the adherend that is desired to be reused will also be affected by deterioration due to heating. Similarly, the adhesive tape can be embrittled and peeled off using an organic solvent or the like, but the problem of deterioration of the adherend occurs as in the case of heating.

  In order to solve the above problem, a transparent pressure-sensitive adhesive sheet strip consisting of three layers, each of which is based on a vinyl hydride aromatic block copolymer and a tackifier resin. (Patent Document 1) has been proposed. However, when three layers based on a vinyl hydride aromatic block copolymer and a tackifier are laminated, sufficient initial adhesion performance may not be obtained. For example, hard adherends with large strains may be stuck together. There were problems such as a decrease in adhesive strength when mating.

  In addition, there is a method of utilizing a pressure-sensitive adhesive tape having a strong adhesive force that is generally used, but it is difficult to ensure sufficient re-peelability, which is a problem, and it is re-peeled after being used in a high temperature or high humidity environment. It wasn't done.

JP 2004-162064 A

  The problem to be solved by the present invention is excellent in followability and adhesion to an adherend, particularly a hard adherend, and when peeling the adhesive tape, the adhesive tape becomes brittle by heating or an organic solvent. Excellent re-peelability that does not need to be applied and does not remain on the adherend, and can be stretched and peeled off in the horizontal direction even after being used in a high-temperature or high-humidity environment. It is providing the adhesive tape which has.

As a result of intensive studies, the present inventors have completed the present invention for solving the above problems.
This invention is an adhesive tape provided with the resin base material containing the vinyl aromatic block copolymer (A), and the adhesion layer, and the tensile strength at the time of 50% expansion | extension of the said adhesion layer is 0.05-10.5MPa The pressure-sensitive adhesive layer has a storage elastic modulus G ′ (23 ° C.) of 1.0 × 10 ^{5 to} 1.0 × 10 ⁷ Pa.

  The pressure-sensitive adhesive tape of the present invention is excellent in followability even when hard adherends such as metal and plastic are bonded to each other, and can be firmly bonded. There is no need to embrittle the tape, and there is no adhesive residue on the adherend, and it can be peeled clean by stretching in the horizontal direction even after being used in high temperature and high humidity environments. The adherend can be reused.

  Below, the structure of the adhesive tape of this invention is demonstrated in more detail.

<Base material>
The adhesive tape of this invention is equipped with the resin base material containing a vinyl aromatic block copolymer (A).

  As the vinyl aromatic block copolymer (A) that can be used for the resin substrate, one or more copolymers selected from block copolymers of an aromatic vinyl compound and a conjugated diene compound can be used. A styrene copolymer in which the aromatic vinyl compound is styrene is preferred. The conjugated diene compound is preferably isoprene, butadiene, ethylene butylene, or ethylene propylene. Especially, as said block copolymer (A), diblock copolymers, such as a styrene-isoprene copolymer, a styrene-butadiene copolymer, a styrene-ethylene butylene copolymer, a styrene-ethylene propylene copolymer. , One or more copolymers selected from triblock copolymers such as styrene-isoprene-styrene copolymer and styrene-butadiene-styrene copolymer are preferable, styrene-isoprene copolymer, styrene- One or two or more types of copolymer selected from a butadiene copolymer, a styrene-ethylenebutylene copolymer, a styrene-isoprene-styrene copolymer, a styrene-butadiene-styrene copolymer, and a styrene-ethylenebutylene copolymer. A styrene-isoprene copolymer, styrene-iso Len - styrene copolymer is particularly preferred.

  The proportion of the vinyl aromatic block copolymer (A) in the resin component contained in the resin base material of the present invention is preferably 50 to 100%, more preferably 60 to 100%, and 65 to 100% is more preferable, and 70 to 100% is even more preferable. By being in this range, the excellent elongation at break and stress at break of the styrene copolymer can be obtained. In addition to the vinyl aromatic block copolymer (A) contained in the base material of the present invention, various thermoplastic resins such as polyolefin and polycarbonate can be used, and one or a plurality of them can be used simultaneously. it can.

  As said styrene-type copolymer, the structural unit shown by following Chemical formula (1) is 13 mass%-60 mass% with respect to the total mass of the said styrene-isoprene copolymer and a styrene-isoprene-styrene copolymer. It is preferable to use what has in the range of 15-50 mass%, It is more preferable to use what has in the range of 15-50 mass%, It is still more preferable to use what has in the range of 16-45 mass% It is even more preferable to use those having a mass% range. Thereby, the elongation at break and the stress at break are easily obtained in a suitable range.

As the styrene-based copolymer, one containing two or more types of copolymers having different structures is used, and one containing a combination of a styrene-isoprene copolymer and a styrene-isoprene-styrene copolymer. I can do it.
The styrene copolymer contains the styrene-isoprene copolymer in a range of 0% by mass to 80% by mass with respect to the total mass of the styrene-isoprene copolymer and the styrene-isoprene-styrene copolymer. It is preferable to use what is contained in the range of 0% by mass to 70% by mass, and it is more preferable to use what is contained in the range of 0% by mass to 50% by mass. More preferably, it is used in the range of 0% by mass to 30% by mass. By setting it as the said range, coexistence with thermal durability is attained, maintaining the elongation at break and the stress at break.

  Moreover, as said styrene-isoprene copolymer, the weight average molecular weight (gel permeation chromatography, SC-8020 by Tosoh Corporation, high molecular weight column TSKgelGMHHR measured by gel permeation chromatography (GPC) in standard polystyrene conversion). -H, solvent: tetrahydrofuran) is preferably used in the range of 10,000 to 800,000, more preferably in the range of 30,000 to 500,000, and more preferably in the range of 50,000 to 300,000. It is even more preferable to use what is. Within the above range, heat fluidity and compatibility at the time of solvent dilution can be ensured, so that it is more preferable for obtaining a pressure-sensitive adhesive tape having thermal durability while having good workability in the manufacturing process.

  The styrenic copolymer can be used, for example, having a single structure such as a linear structure, a branched structure or a multi-branched structure, but it is also possible to use a mixture of different structures. . A styrene copolymer rich in a linear structure gives the elongation at break excellent in the pressure-sensitive adhesive tape of the present invention. On the other hand, those having a styrene block at the molecular terminal, although having a branched structure or a multi-branched structure, can take a pseudo-crosslinked structure and can give excellent cohesive force. For this reason, it is preferable to mix and use according to a required mechanical characteristic.

  The method for producing the styrene-isoprene-styrene copolymer is not particularly limited, and conventionally known production methods can be applied. For example, a method in which a styrene block and an isoprene block are sequentially polymerized by an anion living polymerization method, or a block copolymer having a living active terminal is produced and then reacted with a coupling agent to produce a coupled block copolymer. There is a way.

  The method for producing the styrene-isoprene copolymer is not particularly limited, and conventionally known production methods can be applied. For example, there is a method of sequentially polymerizing a styrene block and an isoprene block by an anion living polymerization method.

  The method for producing the mixture of the styrene-isoprene copolymer and the styrene-isoprene-styrene copolymer is not particularly limited, and conventionally known production methods can be applied. For example, there is a method in which the styrene-isoprene copolymer produced above and a styrene-isoprene-styrene copolymer are mixed and used. It is also possible to produce a mixture simultaneously in one polymerization step. As a more specific embodiment, first, a polystyrene block having a living active terminal by first polymerizing a styrene monomer using an anionic polymerization initiator in a polymerization solvent by an anion living polymerization method. Form. Next, secondly, isoprene is polymerized from the living active end of the polystyrene block to obtain a styrene-isoprene diblock copolymer having a living active end. Subsequently, thirdly, a part of the styrene-isoprene diblock copolymer having the living active terminal is reacted with a coupling agent to form a coupled styrene-isoprene-styrene block copolymer. Fourthly, the remaining part of the styrene-isoprene diblock copolymer having an active end of the living property is a polymerization terminator, and the active end of the living property is deactivated, thereby the styrene-isoprene diblock copolymer. To form.

  Moreover, a tackifier resin can be used for the said base material in order to improve adhesiveness with an adhesion layer, or to improve heat resistance. Among them, a tackifying resin having a softening point of 80 ° C. or higher can be suitably used. The softening point is more preferably 90 ° C. or higher, still more preferably 100 ° C. or higher, and even more preferably 110 ° C. or higher. preferable. The softening point refers to a value measured by a method (dry bulb method) defined in JISK2207.

As the tackifying resins, for example, preferably used ones at ordinary temperature (23 ° C.) solid, C ₅ petroleum resins, C ₅ based / C ₉ petroleum resins, petroleum such as alicyclic petroleum resin Resin can be used.
The petroleum resin is easily compatible with the polyisoprene structure constituting the styrene-isoprene block copolymer and the styrene-isoprene block-styrene copolymer. As a result, the initial adhesive force and the heat durability of the adhesive tape are more improved. This can be further improved.
Examples of the _{C 5} petroleum resins, can be used aliphatic petroleum resin, for example, Escorez 1202,1304,1401 (Tonen Ltd. LLC), Wing Tack 95 (Goodyear Tire & Rubber Company Quinton K100, R100, F100 (manufactured by Zeon Corporation), Picotac 95, Pico Pale 100 (Rika Hercules), and the like can be used.

Examples of the _{C 5} system / _{C 9} petroleum resins, and _{C 5} petroleum resins described above, can be used a copolymer of _{C 9} petroleum resins, for example, Escorez 2101 (manufactured by Tonex), Quinton G115 (Manufactured by Nippon Zeon Co., Ltd.), Hercotac 1149 (manufactured by Rika Hercules) and the like can be used.
As the alicyclic petroleum resin, it is obtained by hydrogenating the above-mentioned _{C 9} petroleum resins, for example, Escorez 5300 (manufactured by Tonex), ARKON P-100 (manufactured by Arakawa Chemical Industries), Rigaraito R101 (Rika Finetech) and the like can be used.

As the tackifier resin, the C ₅ petroleum resins, C ₅ based / C ₉ petroleum resins, and in addition alicyclic petroleum resin, for example, polymerized rosin-based resins, C ₉ petroleum resins, terpene resins A rosin resin, a terpene-phenol resin, a styrene resin, a coumarone-indene resin, a xylene resin, a phenol resin, or the like can be used.
Among them, as the tackifier resin, the use in combination with said C ₅ petroleum resins and polymerized rosin resin, preferable for both the more excellent initial adhesion and heat resistance.

  The tackifier resin is preferably used in the range of 0% by mass to 100% by mass with respect to the total amount of the styrene-isoprene copolymer or styrene-isoprene-styrene copolymer, and 0% by mass to 70% by mass. More preferably, it is used in the range of 0% by mass to 50% by mass, and more preferably in the range of 0% by mass to 30% by mass. By using in the said range, it becomes easy to make compatible the elongation at break and thermal durability which were excellent in the adhesive tape, improving the interface adhesiveness of an adhesion layer and a base material layer.

  In addition, the resin base material may contain other polymer components, crosslinking agents, anti-aging agents, ultraviolet absorbers, fillers, polymerization inhibitors, surface conditioners, antistatic agents as necessary as long as the properties are not impaired. , Antifoaming agents, viscosity modifiers, light stabilizers, weathering stabilizers, heat stabilizers, antioxidants, leveling agents, organic pigments, inorganic pigments, pigment dispersants, silica beads, organic beads, etc .; silicon oxide Further, those containing inorganic fillers such as aluminum oxide, titanium oxide, zirconia, and antimony pentoxide can be used.

As the anti-aging agent, for example, the use of a phenol-based anti-aging agent can effectively improve the heat resistance stability of a styrene-isoprene copolymer, and as a result, good initial adhesiveness is maintained. In addition, the pressure-sensitive adhesive and pressure-sensitive adhesive tape having further excellent heat durability can be obtained, which is preferable.
The phenolic anti-aging agent is generally a phenolic compound having a sterically hindering group, and a monophenol type, a bisphenol type, and a polyphenol type are representative. Specific examples include 2,6-di-tert-butyl-4-methylphenol, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6). -T-butylphenol), 4,4'-thiobis (6-t-butyl-3-methylphenol), 4,4'-butylidenebis- (3-methyl-6-t-butylphenol), tetrakis- [methylene-3 -(3'5'-di-t-butyl-4-hydroxyphenyl) propionate] methane, n-octadecyl-3- (4'-hydroxy-3'5'-di-t-butylphenyl) propionate alone Alternatively, two or more kinds can be used in combination.

The phenol-based anti-aging agent is preferably used in a range of 0.1 to 5 parts by mass with respect to 100 parts by mass of the styrene-isoprene block copolymer, and 0.5 to 3 parts by mass. When used in a range, the heat stability of the styrene-isoprene copolymer can be effectively improved, and as a result, good initial adhesiveness is maintained, and further excellent thermal durability is provided. Adhesive can be obtained.
As the anti-aging agent, the anti-aging agent such as the above-mentioned phenolic anti-aging agent and other anti-aging agents such as phosphorus-based anti-aging agent (also called processing stabilizer), amine-based anti-aging agent and imidazole anti-aging agent are used. In particular, the use of a combination of the above-mentioned phenolic anti-aging agent and phosphorus-based anti-aging agent maintains a good initial adhesiveness, and further provides a pressure-sensitive adhesive with even better thermal durability. Obtainable. In addition, since the phosphorous anti-aging agent may slightly discolor (yellowing) over time in a high-temperature environment, the amount used thereof balances the initial adhesiveness, thermal durability, and discoloration prevention. It is preferable to set appropriately in consideration.

  The base material preferably has a thickness of 100 to 2490 μm, more preferably 120 to 1990 μm, still more preferably 150 to 1790 μm, and even more preferably 200 μm to 1490 μm. When the thickness of the base material is in the above range, the adhesive tape easily follows the distortion of the adherend, and it is easy to obtain high adhesive strength, which is necessary when the adhesive tape is peeled while being stretched in the horizontal direction. This is preferable because the stress does not become too large.

  The elongation at break of the substrate is preferably 600 to 3000%, more preferably 650 to 2800%, still more preferably 700 to 2700%, and 750 to 2600%. Is even more preferred. The elongation at break of the base material is equal to or higher than the lower limit of the range, so that the adhesive tape is stretched in the horizontal direction when the adhesive tape is peeled again even when the adhesive tape is firmly adhered to the adherend. The stress does not become too large, and the adhesive tape can be easily peeled off without excessively extending in the peeling process. In addition, since the elongation at break of the base material is not more than the upper limit of the above range, it is possible to work in a small space without excessively extending the tape in the horizontal direction when the adhesive tape is peeled again. preferable.

  The stress at break of the substrate is preferably 2.5 to 80.0 MPa, more preferably 3.0 to 600 MPa, still more preferably 3.5 to 30 MPa, and 4.0 to 20 MPa. Is more preferable. When the stress at break of the base material is in the above range, the adhesive tape can be prevented from being broken when the adhesive tape is stretched and peeled off, and the load for extending the adhesive tape is not excessive. Therefore, the re-peeling work by peeling becomes easy. Further, the force required to stretch and deform the adhesive tape also depends on the thickness of the adhesive tape. For example, when an adhesive tape having a large thickness and a high stress at break is stretched and re-peeled, it cannot be sufficiently stretched and cannot be re-peeled.

  The stress at 25% elongation of the substrate is preferably 0.15 to 10.0 MPa, more preferably 0.25 to 7.0 MPa, and still more preferably 0.35 to 5.0 MPa. 0.45 to 2.0 MPa is even more preferable. When the stress at 25% elongation of the pressure-sensitive adhesive tape is in the above range, it is possible to obtain a suitable adhesive strength for the pressure-sensitive adhesive tape, and it can be peeled off relatively easily even in the re-peeling step. When less than the said range, when the load to the shearing direction of an adhesive tape arises, fixing the hard adherends, there exists a concern that an adhesive tape may peel off. Moreover, when exceeding the said range, in the peeling process of an adhesive tape, the force required in order to extend an adhesive tape will become excessive.

  The stress at 50% elongation of the substrate is preferably 0.15 to 10.5 MPa, more preferably 0.25 to 7.5 MPa, and still more preferably 0.35 to 5.0 MPa. More preferably, it is 0.5 to 2.5 MPa. When the stress at the time of 50% elongation of the pressure-sensitive adhesive tape is in the above range, it is possible to obtain an adhesive strength suitable for the pressure-sensitive adhesive tape, and it can be peeled off relatively easily even in the re-peeling process. When less than the said range, when the load to the shearing direction of an adhesive tape arises, fixing the hard adherends, there exists a concern that an adhesive tape may peel off. Moreover, when exceeding the said range, in the peeling process of an adhesive tape, the force required in order to extend an adhesive tape will become excessive.

The stress at 50% elongation of the substrate is preferably 100 to 160% of the stress at 25% elongation, more preferably 103 to 150%, still more preferably 105 to 140%, and more preferably 110 to 140%. Even more preferably, it is 130%.
Since the stress at 50% elongation of the pressure-sensitive adhesive tape is in the above range with respect to the stress at 25% elongation of the pressure-sensitive adhesive tape, the stress necessary for peeling in the re-peeling process at the time of re-peeling the pressure-sensitive adhesive tape is stabilized. It becomes possible.

The storage elastic modulus E ′ (23 ° C.) of the base material is preferably 1.0 × 10 ^{4 to} 1.0 × 10 ⁸ Pa, and preferably 5.0 × 10 ^{4 to} 5.0 × 10 ⁷ Pa. more preferably, more preferably from ^{1.0 × 10 5 ~1.0 × 10 7} Pa, and even more preferably ^{3.0 × 10 5 ~7.0 × 10 6} Pa. Suitable because the stress at the breaking point of the substrate is in the above range, it is easy to follow the distortion of the adherend, and excellent adhesive strength can be easily obtained, and the dimensional stability of the adhesive tape can be secured. Achieving easy workability. As described above, it is assumed that the adhesive tape of the present invention has a large area while the adherend is hard such as metal or plastic. In general, the larger the adherend, the more difficult it is to mold while suppressing the strain. However, if the pressure-sensitive adhesive tape has the above storage elastic modulus range, the above-described adherend is not strained. It can be made to follow with an adhesive tape, and a suitable adhesive force can be obtained.

  As the substrate, for the purpose of further improving the adhesion with the pressure-sensitive adhesive layer, a surface provided with a primer layer, surface roughening treatment such as sandblasting or solvent treatment, corona discharge treatment, chromium Those subjected to surface treatment such as acid treatment, flame treatment, hot air treatment, ozone treatment, ultraviolet irradiation treatment and oxidation treatment can be used.

  Examples of the method for producing the substrate include a casting method by extrusion molding, a uniaxial stretching method, a sequential secondary stretching method, a simultaneous biaxial stretching method, an inflation method, a tube method, a calendar method, and a solution method. Among them, a cast method by extrusion molding, a uniaxial stretching method, a sequential secondary stretching method, a simultaneous biaxial stretching method, an inflation method, and a tube method can be suitably used, and the mechanical strength required for the adhesive tape of the present invention is matched. To select.

  The substrate may have a single layer structure, a two-layer structure, a three-layer structure or more. In the case of a multilayer structure, it is preferable that at least one layer is a layer having the above-described resin composition because necessary mechanical characteristics are easily exhibited. Further, for example, a base material having a three-layer structure can be obtained by a method of co-extruding a thermoplastic resin such as polypropylene and the styrene-isoprene-styrene copolymer. This may be used as a suitable configuration for the pressure-sensitive adhesive tape of the present invention, for example, when it is desired to have appropriate dimensional stability and stiffness.

<Adhesive layer>
The adhesive layer of the adhesive tape of the present invention has a 50% elongation stress of 0.05 to 10.5 MPa, more preferably 0.07 to 7.5 MPa, and 0.1 to 5.5 MPa. Is more preferable and 0.15-3.5 MPa is even more preferable. When the stress at the time of 50% elongation of the pressure-sensitive adhesive layer is in the above range, excellent adhesiveness and removability of the pressure-sensitive adhesive tape can be obtained. That is, it is easy to follow the distortion of the adherend and excellent adhesive strength can be obtained, and it is possible to suppress the adhesive layer from remaining on the adherend in the adhesive tape re-peeling step.

The adhesive layer of the adhesive tape of the present invention has a storage elastic modulus G ′ (23 ° C.) of 1.0 × 10 ^{5 to} 1.0 × 10 ⁷ Pa, but 1.0 × 10 ^{5 to} 8.0 × 10. ⁶ Pa is preferable, 1.0 × 10 ^{5 to} 5.0 × 10 ⁶ Pa is more preferable, 1.0 × 10 ^{5 to} 4.0 × 10 ⁶ Pa is further preferable, and 1.0 × 10 ^{5 to} 3. 0 × 10 ⁶ Pa is most preferable. By having the storage elastic modulus G ′ (23 ° C.) of the pressure-sensitive adhesive layer in the above range, it is possible to obtain excellent adhesiveness and re-peelability of the pressure-sensitive adhesive tape, especially after being used in a high temperature or high humidity environment. Moreover, it can suppress that an adhesive layer remains on a to-be-adhered body at the re-peeling process of an adhesive tape.

  The thickness of the adhesive layer is preferably 1/2 to 1/500, more preferably 1/3 to 1/300, and more preferably 1/5 to 1/200 with respect to the thickness of the base material layer. More preferably, it is even more preferably 1/10 to 1/50. The adhesiveness and removability which were excellent in the adhesive tape can be acquired because the thickness ratio of the adhesive layer and base material layer of an adhesive tape exists in the said range. In the pressure-sensitive adhesive tape of the present invention, the cohesive force of the pressure-sensitive adhesive layer is lower than the cohesive force of the base material. Therefore, when the pressure-sensitive adhesive layer is thicker than the above range, only the pressure-sensitive adhesive layer is attached in the re-peeling process of the pressure-sensitive adhesive tape. May remain in the body. Further, when the pressure-sensitive adhesive layer is thinner than the above range, there is a concern that the adhesive strength cannot be remarkably lowered because the pressure-sensitive adhesive layer cannot follow when the surface of the adherend is uneven.

  The stress at break of the pressure-sensitive adhesive layer used in the pressure-sensitive adhesive tape of the present invention is preferably 0.5 to 25.0 MPa, more preferably 0.8 to 20.0 MPa, and 1.0 to 17.0 MPa. It is still more preferable, and it is still more preferable that it is 1.2-15.0 MPa. When the stress at break of the adhesive layer is in the above range, excellent adhesiveness can be exhibited, and the adhesive component hardly remains on the adherend when the adhesive tape of the present invention is stretched and peeled in the horizontal direction. Therefore, it is preferable.

  As the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape of the present invention, those containing the vinyl aromatic block copolymer (B) are preferable from the viewpoint of followability to the substrate and adhesion. Of these, one or more copolymers selected from block copolymers of aromatic vinyl compounds and conjugated diene compounds can be used, and styrene copolymers in which the aromatic vinyl compound is styrene are preferred. . The conjugated diene compound is preferably isoprene, butadiene, ethylene butylene, or ethylene propylene. Especially, as said block copolymer (B), diblock copolymers, such as a styrene-isoprene copolymer, a styrene-butadiene copolymer, a styrene-ethylene butylene copolymer, and a styrene-ethylene propylene copolymer. , One or more copolymers selected from triblock copolymers such as styrene-isoprene-styrene copolymer and styrene-butadiene-styrene copolymer are preferable, styrene-isoprene copolymer, styrene- One or more copolymers selected from butadiene copolymers, styrene-ethylene butylene copolymers, styrene-isoprene-styrene copolymers, and styrene-butadiene-styrene copolymers are more preferred, and styrene-isoprene. Selected from copolymers, styrene-isoprene-styrene copolymers Species or two or more copolymers are particularly preferred.

  As said vinyl aromatic block copolymer, the structural unit shown by following Chemical formula (2) is 10 mass%-80 with respect to the total mass of the said styrene-isoprene copolymer and a styrene-isoprene-styrene copolymer. It is preferable to use what has in the range of 12 mass%, it is more preferable to use what has in the range of 12-60 mass%, and it is still more preferable to use what has in the range of 15-40 mass%. It is even more preferable to use what has in the range of -35 mass%. Thereby, the outstanding adhesiveness and heat resistance can be obtained.

As the vinyl aromatic block copolymer, those containing two or more types of copolymers having different structures can be used, and a combination of a styrene-isoprene copolymer and a styrene-isoprene-styrene copolymer is contained. You can use what you want.
The styrene resin contains the styrene-isoprene copolymer in a range of 0% by mass to 80% by mass with respect to the total mass of the styrene-isoprene copolymer and the styrene-isoprene-styrene copolymer. Is preferably used, more preferably 0 to 77% by mass, more preferably 0 to 75% by mass, and still more preferably 0 to 75% by mass. It is even more preferable to use in the range of mass% to 70 mass%. By setting it as the said range, the adhesive performance excellent in the adhesive tape of this invention and thermal durability can be made to make compatible.

  Moreover, as said styrene-isoprene copolymer, the weight average molecular weight (gel permeation chromatography, SC-8020 by Tosoh Corporation, high molecular weight column TSKgelGMHHR measured by gel permeation chromatography (GPC) in standard polystyrene conversion). -H, solvent: tetrahydrofuran) is preferably used in the range of 10,000 to 800,000, more preferably in the range of 30,000 to 500,000, and more preferably in the range of 50,000 to 300,000. It is even more preferable to use what is. Within the above range, heat fluidity and compatibility at the time of solvent dilution can be ensured, so that it is more preferable for obtaining a pressure-sensitive adhesive tape having thermal durability while having good workability in the manufacturing process.

  The styrenic copolymer can be used, for example, having a single structure such as a linear structure, a branched structure or a multi-branched structure, but it is also possible to use a mixture of different structures. . When a styrenic resin rich in linear structure is used for the adhesive layer, the adhesive tape of the present invention has excellent adhesive performance. On the other hand, those having a styrene block at the molecular end while having a branched structure or a multi-branched structure can take a pseudo-crosslinked structure and can give an excellent cohesive force, thus giving a high holding power. . These are preferably mixed and used according to the required characteristics.

  The method for producing the styrene-isoprene-styrene copolymer is not particularly limited, and a conventionally known production method can be applied, and the styrene-isoprene-styrene copolymer can be produced by the same method as described for the substrate.

  Moreover, tackifying resin can be used for the adhesive of the adhesive tape of this invention, and it is preferable to use the tackifying resin whose softening point is 80 degreeC or more among them. Thereby, the adhesive and adhesive tape provided with the outstanding initial adhesiveness and thermal durability can be obtained. The softening point refers to a value measured by a method (dry bulb method) defined in JISK2207.

The tackifying resins, for example, it is preferable to use a solid at ordinary temperature (23 ℃), C ₅ petroleum resins, C ₅ based / C ₉ petroleum resins, petroleum resins such as alicyclic petroleum resin Can be used. The petroleum resin is easily compatible with the polyisoprene structure constituting the styrene resin, and as a result, the initial adhesive force and thermal durability of the pressure-sensitive adhesive and pressure-sensitive adhesive tape can be further improved.
Examples of the _{C 5} petroleum resins, can be used aliphatic petroleum resin, for example, Escorez 1202,1304,1401 (Tonen Ltd. LLC), Wing Tack 95 (Goodyear Tire & Rubber Company Quinton K100, R100, F100 (manufactured by Zeon Corporation), Picotac 95, Pico Pale 100 (Rika Hercules), and the like can be used.

Examples of the _{C 5} system / _{C 9} petroleum resins, and _{C 5} petroleum resins described above, can be used a copolymer of _{C 9} petroleum resins, for example, Escorez 2101 (manufactured by Tonex), Quinton G115 (Manufactured by Nippon Zeon Co., Ltd.), Hercotac 1149 (manufactured by Rika Hercules) and the like can be used.
As the alicyclic petroleum resin, it is obtained by hydrogenating the above-mentioned _{C 9} petroleum resins, for example, Escorez 5300 (manufactured by Tonex), ARKON P-100 (manufactured by Arakawa Chemical Industries), Rigaraito R101 (Rika Finetech) and the like can be used.

Examples of the tackifying resin having a softening point of 80 ° C. or higher include, in addition to the C ₅ petroleum resin, C ₅ / C ₉ petroleum resin, and alicyclic petroleum resin, for example, a polymerized rosin resin, C ₉ Series petroleum resins, terpene resins, rosin resins, terpene-phenol resins, styrene resins, coumarone-indene resins, xylene resins, phenol resins, and the like can be used.
Among them, as the softening point of 80 ° C. or more tackifier resins, the use in combination with said C ₅ petroleum resins and polymerized rosin resin, both a more excellent initial adhesion and heat resistance This is preferable.
The tackifying resin having a softening point of 80 ° C. or higher is preferably used in a range of 3% by mass to 100% by mass with respect to the total amount of the styrenic resin, and is used in a range of 5% by mass to 80% by mass. It is more preferable to use the resin in the range of 5% by mass to 80% by mass in order to obtain a pressure-sensitive adhesive and pressure-sensitive adhesive tape that have both excellent adhesiveness and excellent thermal durability.

For the purpose of obtaining stickability and initial adhesiveness in a constant temperature environment, a tackifying resin having a softening point of −5 ° C. or lower can be used in combination with the tackifying resin having a softening point of 80 ° C. or higher. The pour point refers to a value measured by a method based on the method defined in JISK2269.
As the tackifying resin having a softening point of −5 ° C. or lower, it is preferable to use a tackifying resin that is liquid at room temperature. Such a tackifying resin that is liquid at room temperature is preferably selected from the known tackifying resins.
As the tackifying resin having a softening point of −5 ° C. or less, for example, liquid rubber such as process oil, polyester, and polybutene can be used, and in particular, the use of polybutene makes even better initial adhesion. It is preferable for expressing the sex.

The tackifying resin having a softening point of −5 ° C. or lower is preferably used in the range of 0% by mass to 40% by mass, and in the range of 0% by mass to 30% by mass, based on the total amount of the tackifying resin. More preferably.
The tackifying resin having a softening point of −5 ° C. or lower is preferably used in the range of 0% by mass to 40% by mass, and in the range of 0% by mass to 30% by mass with respect to the total amount of the styrenic resin. The use can improve the initial adhesive force and achieve good adhesion, and can obtain sufficient thermal durability.

  The mass ratio of the tackifying resin having a softening point of 80 ° C. or higher and the tackifying resin having a softening point of −5 ° C. or lower is preferably in the range of 5-50, and in the range of 10-30, It is more preferable to obtain a pressure-sensitive adhesive and pressure-sensitive adhesive tape that have both excellent initial adhesiveness and excellent holding power.

  The styrenic resin and the tackifier resin are preferably used in combination in a range where the mass ratio represented by [styrene resin / tackifier resin] is 0.5 to 10.0, 0.6 to When used within the range of 9.0, the initial adhesive force can be improved, and excellent thermal durability can be obtained. The mass ratio [styrene-based resin / tackifier resin] is greater than 1, for example, preventing peeling due to the repulsive force of the adhesive tape when affixed to the curved surface of the adherend (resilience resistance) Is preferable.

  As an additive for pressure-sensitive adhesives, other polymer components, cross-linking agents, anti-aging agents, UV absorbers, fillers, polymerization inhibitors, surface conditioners, antistatic agents, anti-extinguishing agents can be used as long as they do not impair the properties. Foaming agent, viscosity modifier, light stabilizer, weather stabilizer, heat stabilizer, antioxidant, leveling agent, organic pigment, inorganic pigment, pigment dispersant, plasticizer, softener, flame retardant, metal deactivator, It is possible to use those containing additives such as silica beads and organic beads; inorganic fillers such as silicon oxide, aluminum oxide, titanium oxide, zirconia and antimony pentoxide.

  As the anti-aging agent, those which can be generally used for pressure-sensitive adhesives can be applied, but those as described in the item of the base material are mentioned as an example.

Examples of the method for producing the substrate include a casting method by extrusion molding, a uniaxial stretching method, a sequential secondary stretching method, a simultaneous biaxial stretching method, an inflation method, a tube method, a calendar method, and a solution method. Among them, a production method by a cast method by extrusion molding or a solvent method can be suitably used, and it may be selected in accordance with compatibility of the thickness control of the adhesive layer and the lamination method with the base material.
Also in the case of the solvent method, a method of directly applying to a substrate with a roll coater or the like, and a method of once forming an adhesive layer on a release liner and then transferring to a substrate are used. In order to obtain smoothness suitable for the pressure-sensitive adhesive layer, a method of once forming the pressure-sensitive adhesive layer on the release liner and transferring it to the substrate is preferable.

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

<Adhesive tape>
The thickness of the adhesive tape is preferably greater than 150 μm, more preferably 170 μm or more, more preferably 200 μm or more, and particularly preferably 250 μm or more. The thickness of the adhesive tape is 2500 μm or less, preferably 2000 μm or less, more preferably 1800 μm or less, and particularly preferably 1500 μm or less. When the thickness of the adhesive tape is within the above range, it is easy to follow the distortion of the adherend, and it is easy to obtain excellent adhesive strength, which is necessary when the adhesive tape is stretched horizontally and re-peeled. This is preferable because the stress is not too large. In the pressure-sensitive adhesive tape of the present invention, it is assumed that the adherend is a hard material such as metal or plastic but has a large area. In general, the larger the adherend, the more difficult it is to mold while suppressing distortion. By following such distortion of the adherend with an adhesive tape, a precise mechanism such as an electronic device can be completed more accurately.

  The elongation at break of the adhesive tape is preferably 600 to 3000%, more preferably 650 to 2800%, still more preferably 700 to 2700%, and more preferably 750 to 2600%. Even more preferable. As described above, the pressure-sensitive adhesive tape of the present invention is a relatively thick pressure-sensitive adhesive tape having a thickness of more than 150 and less than 1500 μm, and possesses strong adhesive strength. When the adhesive tape strongly bonded as in the present invention is stretched and peeled off, it is in the range of elongation at break so that even when the adhesive tape is firmly adhered to the adherend, It can be peeled off by a tensile stress, and can be easily peeled off without excessively stretching the adhesive tape in the peeling process.

  The stress at break of the adhesive tape is preferably 2.5 to 80.0 MPa, more preferably 3.0 to 60.0 MPa, still more preferably 3.5 to 30.0 MPa. More preferably, it is 0.0-20.0 MPa. When the stress at break of the adhesive tape is in the above range, the adhesive tape will not be broken even when the adhesive tape is stretched and peeled off, and it is easy to suitably stretch the adhesive tape. It becomes easy. Further, the force required to stretch and deform the adhesive tape also depends on the thickness of the adhesive tape. For example, when an adhesive tape having a large thickness and a high stress at break is stretched and re-peeled, it cannot be sufficiently stretched and cannot be re-peeled.

  The stress at 25% elongation of the adhesive tape is preferably 0.05 to 10.0 MPa, more preferably 0.15 to 5.0 MPa, and still more preferably 0.2 to 3.0 MPa. 0.3 to 2.0 MPa is even more preferable. When the stress at 25% elongation of the pressure-sensitive adhesive tape is in the above range, it is possible to obtain a suitable adhesive strength for the pressure-sensitive adhesive tape, and it can be peeled off relatively easily even in the re-peeling step. When less than the said range, when the load to the shearing direction of an adhesive tape arises, fixing the hard adherends, there exists a concern that an adhesive tape may peel off. Moreover, when exceeding the said range, in the peeling process of an adhesive tape, the force required in order to extend an adhesive tape will become excessive.

  The stress at 50% elongation of the adhesive tape is preferably 0.07 to 10.5 MPa, more preferably 0.17 to 5.5 MPa, and further preferably 0.25 to 3.5 MPa. 0.3 to 2.5 MPa is even more preferable. When the stress at the time of 50% elongation of the pressure-sensitive adhesive tape is in the above range, it is possible to obtain an adhesive strength suitable for the pressure-sensitive adhesive tape, and it can be peeled off relatively easily even in the re-peeling process. When less than the said range, when the load to the shearing direction of an adhesive tape arises, fixing the hard adherends, there exists a concern that an adhesive tape may peel off. Moreover, when exceeding the said range, in the peeling process of an adhesive tape, the force required in order to extend an adhesive tape will become excessive.

The stress at 50% elongation of the adhesive tape is preferably 100 to 160% of the stress at 25% elongation, more preferably 103 to 150%, still more preferably 105 to 140%, and more preferably 110 to 140%. Even more preferably, it is 130%.
Since the stress at 50% elongation of the pressure-sensitive adhesive tape is in the above range with respect to the stress at 25% elongation of the pressure-sensitive adhesive tape, the stress necessary for peeling in the re-peeling process at the time of re-peeling the pressure-sensitive adhesive tape is stabilized. It becomes possible.

The storage elastic modulus E ′ (23 ° C.) of the adhesive tape is preferably 1.0 × 10 ^{4 to} 1.0 × 10 ⁸ Pa, and preferably 5.0 × 10 ^{4 to} 5.0 × 10 ⁷ Pa. more preferably, more preferably from ^{1.0 × 10 5 ~1.0 × 10 7} Pa, and even more preferably ^{3.0 × 10 5 ~8.0 × 10 6} Pa. It is preferable that the stress at break of the pressure-sensitive adhesive tape is in the above range, and it is easy to follow the distortion of the adherend and excellent adhesive strength can be obtained, and the dimensional stability of the pressure-sensitive adhesive tape can be secured. Achieving easy workability. As described above, the pressure-sensitive adhesive tape of the present invention is assumed to have a large area while the adherend is hard such as metal or plastic. In general, the larger the adherend, the more difficult it is to mold while suppressing distortion. If it is an adhesive tape which has the said storage elastic modulus range, the distortion of the above-mentioned to-be-adhered body can be tracked with an adhesive tape, and suitable adhesive force can be obtained.

  The adhesive strength of 180 ° peel of the pressure-sensitive adhesive tape is preferably 5 N / 20 mm or more, more preferably 7 N / 20 mm or more, still more preferably 9 N / 20 mm or more, and even more preferably 12 N / 20 mm or more. When the 180 ° peel adhesive strength of the pressure-sensitive adhesive tape is in the above range, excellent adhesiveness is easily obtained even when the adherends are rigid bodies. When the adhesive tape is stretched as in the present invention, the adhesive strength below the 180 ° peel in the above range is suggested to be low in the interfacial adhesive strength to the adherend. For this reason, when it uses for bonding of rigid bodies, there exists a possibility that sufficient adhesion | attachment behavior may no longer be obtained.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[Example 1]
(Preparation of adhesive layer)
Resin composition (1) (styrene-isoprene copolymer and styrene-isoprene-styrene copolymer mixture, styrene-derived structural unit 24% by mass represented by the chemical formula (2), and the resin composition (1) styrene to the total amount - proportion of the isoprene copolymer 67 wt%) 100 parts by weight, Quinton G115 (Nippon Zeon Co., Ltd. of _{C 5} system / _{C 9} petroleum resin, softening point 115 ° C.) 40 parts by mass, PENSEL D- 160 (polymerized rosin ester resin manufactured by Arakawa Chemical Industries, Ltd., softening point 150 ° C. to 165 ° C.) 30 parts by mass, Nisseki Polybutene HV-50 (polybutene manufactured by JX Nippon Mining & Energy Corporation, pour point −12.5 ° C.) 5 parts by mass and an antioxidant (tetrakis- [methylene-3- (3′5′-di-t-butyl-4-hydroxyphenyl) propionate] Tan) 1 part by mass was mixed and dissolved in 100 parts by mass of toluene as a solvent to obtain a pressure-sensitive adhesive (1).
The pressure-sensitive adhesive (1) was coated on a release paper with an applicator so that the thickness after drying was 5 μm, and dried at 80 ° C. for 3 minutes to prepare a pressure-sensitive adhesive layer (1).

(Manufacture of adhesive tape)
Resin composition (2) (styrene-isoprene copolymer and styrene-isoprene-styrene copolymer mixture, 25 mass% of styrene-derived structural unit represented by the chemical formula (1), and the resin composition (2) A base material having a thickness of 200 μm was prepared by heat pressing (pressure 0.5 MPa, press plate temperature 130 ° C., press time 2 minutes) with a styrene-isoprene copolymer ratio of 17% by mass with respect to the total amount. The pressure-sensitive adhesive layer (1) prepared above was bonded to both surfaces and pressed and laminated at 0.2 MPa to prepare a pressure-sensitive adhesive tape.

[Example 2]
An adhesive tape was produced in the same manner as in Example 1 except that the resin composition (2) used for the base material of the adhesive tape was replaced with the resin composition (1).

Example 3
(Manufacture of adhesive tape)
Resin composition (3) (styrene-isoprene-styrene copolymer, 18 mass% of styrene-derived structural unit represented by chemical formula (1)) is heat-pressed (pressure 0.5 MPa, press plate temperature 130 ° C., press A substrate having a thickness of 200 μm was prepared by 2 hours). The pressure-sensitive adhesive layer (1) prepared above was bonded to both surfaces and pressed and laminated at 0.2 MPa to prepare a pressure-sensitive adhesive tape.

Example 4
(Manufacture of adhesive tape)
Resin Composition (4) (Styrene-Ethylene Butylene-Styrene Copolymer and Styrene-Ethylene Butylene Copolymer Mixture, 30% by Mass of Structural Unit Derived from Styrene Shown by Chemical Formula (1), Resin Composition (4 ) To produce a base material having a thickness of 200 μm by heat pressing (pressure 0.5 MPa, press plate temperature 130 ° C., press time 2 minutes). did. The pressure-sensitive adhesive layer (1) prepared above was bonded to both surfaces and pressed and laminated at 0.2 MPa to prepare a pressure-sensitive adhesive tape.

Example 5
Resin composition (5) (styrene-isoprene copolymer and styrene-isoprene-styrene copolymer mixture, 15 mass% of structural unit derived from styrene represented by chemical formula (2), total amount of composition (5) to styrene - ratio 78 wt%) 100 parts by weight of the isoprene copolymer, Quinton G115 (Nippon Zeon Co., Ltd. of _{C 5} system / _{C 9} petroleum resin, softening point 115 ° C.) 40 parts by mass, Pensel D-160 (Polymerized rosin ester resin manufactured by Arakawa Chemical Industries, Ltd., softening point 150 ° C. to 165 ° C.) 30 parts by mass, Nisseki Polybutene HV-50 (polybutene manufactured by JX Nippon Mining & Energy Corporation, pour point −12.5 ° C. ) 5 parts by weight and an antioxidant (tetrakis- [methylene-3- (3′5′-di-t-butyl-4-hydroxyphenyl) propionate] methane ) 1 part by mass was mixed and dissolved in 100 parts by mass of toluene as a solvent to obtain an adhesive (2).
The pressure-sensitive adhesive (2) was coated on a release paper with an applicator so that the thickness after drying was 5 μm, and dried at 85 ° C. for 3 minutes to prepare a pressure-sensitive adhesive layer (2).

(Manufacture of adhesive tape)
A base material having a thickness of 200 μm was prepared by heat-pressing the resin composition 2 (pressure 0.5 MPa, press plate temperature 130 ° C., press time 2 minutes). The pressure-sensitive adhesive layer (2) prepared above was bonded to both surfaces and pressed and laminated at 0.2 MPa to prepare a pressure-sensitive adhesive tape.

Example 6
The resin composition (2) 100 parts by weight, Quinton G115 (Nippon Zeon Co., Ltd. of _{C 5} system / _{C 9} petroleum resin, softening point 115 ° C.) 16 parts by weight, Pensel D-160 (Arakawa Chemical Industries, Ltd. Polymerized rosin ester resin, softening point 150 ° C. to 165 ° C. 12 parts by mass, Nisseki Polybutene HV-50 (polybutene manufactured by JX Nippon Mining & Energy Corporation, pour point −12.5 ° C.) 2 parts by mass and anti-aging 1 part by weight of an agent (tetrakis- [methylene-3- (3′5′-di-t-butyl-4-hydroxyphenyl) propionate] methane) and dissolved in 100 parts by weight of toluene as a solvent (3) was obtained.
The pressure-sensitive adhesive (3) was coated on a release paper with an applicator so that the thickness after drying was 5 μm, and dried at 80 ° C. for 3 minutes to prepare a pressure-sensitive adhesive layer (3).

(Manufacture of adhesive tape)
A base material having a thickness of 200 μm was prepared by heat-pressing the resin composition (2) (pressure 0.5 MPa, press plate temperature 130 ° C., press time 2 minutes). The pressure-sensitive adhesive layer (3) prepared above was bonded to both sides and pressed and laminated at 0.2 MPa to prepare a pressure-sensitive adhesive tape.

Example 7
The resin composition (2) 100 parts by weight, Quinton G115 (Nippon Zeon Co., Ltd. of _{C 5} system / _{C 9} petroleum resin, softening point 115 ° C.) 8 parts by weight, Pensel D-160 (Arakawa Chemical Industries, Ltd. Polymerized rosin ester resin, softening point 150 ° C. to 165 ° C.) 6 parts by mass, Nisseki Polybutene HV-50 (polybutene manufactured by JX Nippon Mining & Energy Corporation, pour point −12.5 ° C.) 1 part by mass and anti-aging 1 part by weight of an agent (tetrakis- [methylene-3- (3′5′-di-t-butyl-4-hydroxyphenyl) propionate] methane) and dissolved in 100 parts by weight of toluene as a solvent (4) was obtained.
The pressure-sensitive adhesive (4) was applied on a release paper with an applicator so that the thickness after drying was 5 μm, and dried at 80 ° C. for 3 minutes to prepare a pressure-sensitive adhesive layer (4).

(Manufacture of adhesive tape)
A base material having a thickness of 200 μm was prepared by heat-pressing the resin composition (2) (pressure 0.5 MPa, press plate temperature 130 ° C., press time 2 minutes). The pressure-sensitive adhesive layer (4) prepared above was bonded to both surfaces and pressed and laminated at 0.2 MPa to prepare a pressure-sensitive adhesive tape.

Example 8
The resin composition (2) 100 parts by weight, Quinton G115 (Nippon Zeon Co., Ltd. of _{C 5} system / _{C 9} petroleum resin, softening point 115 ° C.) 24 parts by weight, Pensel D-160 (Arakawa Chemical Industries, Ltd. Polymerized rosin ester resin, softening point 150 ° C. to 165 ° C.) 18 parts by mass, Nisseki Polybutene HV-50 (polybutene made by JX Nippon Mining & Energy Corporation, pour point −12.5 ° C.) 3 parts by mass and anti-aging 1 part by weight of an agent (tetrakis- [methylene-3- (3′5′-di-t-butyl-4-hydroxyphenyl) propionate] methane) and dissolved in 100 parts by weight of toluene as a solvent (5) was obtained.
The pressure-sensitive adhesive 4 was coated on a release paper with an applicator so that the thickness after drying was 5 μm, and dried at 80 ° C. for 3 minutes to prepare a pressure-sensitive adhesive layer (5).

(Manufacture of adhesive tape)
A base material having a thickness of 200 μm was prepared by heat-pressing the resin composition (2) (pressure 0.5 MPa, press plate temperature 130 ° C., press time 2 minutes). The pressure-sensitive adhesive layer (5) prepared above was bonded to both surfaces, and the pressure-sensitive adhesive tape was produced by laminating by pressing at 0.2 MPa.

Example 9
The resin composition (1) 100 parts by weight, Quinton G115 (Nippon Zeon Co., Ltd. of _{C 5} system / _{C 9} petroleum resin, softening point 115 ° C.) 16 parts by weight, Pensel D-160 (Arakawa Chemical Industries, Ltd. Polymerized rosin ester resin, softening point 150 ° C. to 165 ° C. 12 parts by mass, Nisseki Polybutene HV-50 (polybutene manufactured by JX Nippon Mining & Energy Corporation, pour point −12.5 ° C.) 2 parts by mass and anti-aging 1 part by weight of an agent (tetrakis- [methylene-3- (3′5′-di-t-butyl-4-hydroxyphenyl) propionate] methane) and dissolved in 100 parts by weight of toluene as a solvent (6) was obtained.
The pressure-sensitive adhesive 5 was applied on a release paper with an applicator so that the thickness after drying was 5 μm, and dried at 80 ° C. for 3 minutes to prepare a pressure-sensitive adhesive layer (6).

(Manufacture of adhesive tape)
A base material having a thickness of 200 μm was prepared by heat-pressing the resin composition (2) (pressure 0.5 MPa, press plate temperature 130 ° C., press time 2 minutes). The pressure-sensitive adhesive layer (6) prepared above was bonded to both surfaces and pressed and laminated at 0.2 MPa to produce a pressure-sensitive adhesive tape.

Example 10
An adhesive tape was prepared in the same manner as in Example 1 except that the thickness of the adhesive (1) was 25 μm.

Example 11
An adhesive tape was prepared in the same manner as in Example 1 except that the thickness of the resin composition (2) used for the base material of the adhesive tape was 400 μm.

Example 12
An adhesive tape was produced in the same manner as in Example 1 except that the thickness of the adhesive layer of the adhesive tape was 50 μm.

Example 13
(Manufacture of adhesive tape)
A base material having a thickness of 1000 μm was produced by heat pressing the resin composition (3) (pressure 0.5 MPa, press plate temperature 130 ° C., press time 2 minutes). The pressure-sensitive adhesive layer (1) prepared above was bonded to both surfaces and pressed and laminated at 0.2 MPa to prepare a pressure-sensitive adhesive tape.

Example 14
The resin composition 2 to 100 parts by mass, Quinton G115 (Nippon Zeon Co., Ltd. of _{C 5} system / _{C 9} petroleum resin, softening point 115 ° C.) 8 parts by weight, Pensel D-160 (polymerization manufactured by Arakawa Chemical Industries, Ltd. Rosin ester resin, softening point 150 ° C. to 165 ° C.) 6 parts by mass, Nisseki Polybutene HV-50 (polybutene manufactured by JX Nippon Oil & Energy Corporation, pour point −12.5 ° C.) 1 part by mass and anti-aging agent ( Tetrakis- [methylene-3- (3′5′-di-t-butyl-4-hydroxyphenyl) propionate] methane) 1 part by mass is mixed and dissolved in 100 parts by mass of toluene as a solvent to produce an adhesive (7 )

(Manufacture of adhesive tape)
The pressure-sensitive adhesive (7) was coated on a release paper with an applicator so that the thickness after drying was 66 μm, dried at 80 ° C. for 3 minutes, and pasted three sheets to produce a pressure-sensitive adhesive tape having a total thickness of 198 μm. .

[Comparative Example 1]
An adhesive tape was prepared in the same manner as in Example 1 except that a PET film having a thickness of 188 μm was used as the substrate instead of the resin composition (1).

[Comparative Example 2]
(Preparation of adhesive layer)
In a reaction vessel equipped with a stirrer, reflux condenser, thermometer, dropping funnel and nitrogen gas inlet, 60 parts by mass of n-butyl acrylate, 35.95 parts by mass of 2-ethylhexyl acrylate, 4.0 parts by mass of acrylic acid, 4 -0.05 part by weight of hydroxybutyl acrylate and 0.2 part by weight of 2,2'-azobisisobutylnitrile as a polymerization initiator were dissolved in a mixed solvent of 50 parts by weight of ethyl acetate and 20 parts by weight of n-hexane. These were polymerized at 70 ° C. for 8 hours to obtain an acrylic copolymer solution having a weight average molecular weight of 700,000.
Next, 20 parts by mass of a polymerized rosin ester resin (Arakawa Chemical Industries, Ltd., D-125), 100 parts by mass of a solid content of the acrylic copolymer having a weight average molecular weight of 700,000, a disproportionated rosin ester An acrylic pressure-sensitive adhesive composition (1) was obtained by adding 10 parts by mass (A100 manufactured by Arakawa Chemical Co., Ltd.) and adjusting the solid content concentration to 45% by mass using ethyl acetate.

Next, 100 parts by mass (45 parts by mass of solid content) of the acrylic pressure-sensitive adhesive composition (1) and a crosslinking agent (manufactured by DIC Corporation, Vernock NC-40, isocyanate-based crosslinking agent, solid content of 40% by mass, acetic acid The pressure-sensitive adhesive (8) was obtained by mixing 2.0 parts by mass of the ethyl solution) and mixing them for 10 minutes using a dispersion stirrer.
The pressure-sensitive adhesive (8) was coated on a release liner with an applicator so that the thickness after drying was 5 μm, and dried at 80 ° C. for 3 minutes to prepare a pressure-sensitive adhesive layer (8).

(Manufacture of adhesive tape)
A base material having a thickness of 200 μm was prepared by heat-pressing the resin composition (2) (pressure 0.5 MPa, press plate temperature 130 ° C., press time 2 minutes). The pressure-sensitive adhesive layer (7) prepared above was bonded to both surfaces and pressed and laminated at 0.2 MPa to prepare a pressure-sensitive adhesive tape.

[Comparative Example 3]
(Manufacture of adhesive tape)
A pressure-sensitive adhesive tape is prepared by laminating the pressure-sensitive adhesive layer (1) prepared above on both sides of the resin composition (6) (ester polyurethane compound) having a thickness of 200 μm and pressing and laminating at 0.2 MPa. did.

[Comparative Example 4]
The pressure-sensitive adhesive (8) was applied on a release liner with an applicator so that the thickness after drying was 65 μm, and dried at 65 ° C. for 10 minutes to prepare a pressure-sensitive adhesive layer (9). Three pressure-sensitive adhesive layers (9) were bonded together, pressed at 0.2 MPa, and laminated to prepare a pressure-sensitive adhesive tape.

  The pressure-sensitive adhesive tapes, substrates and pressure-sensitive adhesive layers prepared in Examples 1 to 13 and Comparative Examples 1 to 4 were tested by the methods shown below, and the evaluation results are shown in Tables 1 and 2.

[Adhesive tape and substrate, stress at break of adhesive, elongation at break, stress at 25% elongation, stress at 50% elongation]
The stress at break of the adhesive tape, the elongation at break, the stress at 25% elongation, and the stress at 50% elongation were obtained by punching the adhesive tape into a dumbbell shape with a marked line length of 20 mm and a width of 10 mm, and a measurement atmosphere of 23 ° C. and 50% RH. Using a Tensilon tensile tester, the sample was pulled in the length direction at a tensile speed of 300 mm / min.

[Storage modulus E ′ of adhesive tape and substrate]
A test piece obtained by punching the adhesive tape obtained in Examples and Comparative Examples into the shape of JIS K 7127 test piece type 5 using a dumbbell cutter was used.
Using the test piece, measurement was performed with a dynamic viscoelasticity measuring device RSA-II (frequency: 1 Hz, temperature rising rate: 3 ° C./min) manufactured by Rheometrics, and storage elastic modulus E ′ at 23 ° C. was obtained.

[Storage modulus G ′ of adhesive layer]
In the present invention, the storage elastic modulus G ′ is obtained by using a laminated adhesive up to a thickness of 2 mm as a test piece, attaching a parallel plate having a diameter of 7.9 mm to a rheometer viscoelasticity tester Ares 2kSTD, and sandwiching the test piece. It is a value measured at 1 Hz.

[Adhesive strength]
An adhesive tape sample having a width of 20 mm was attached to a stainless steel plate at 23 ° C., and a reciprocating pressure was applied to a 2 kg roller. After standing at 23 ° C. for 1 hour, the tensile strength was measured using a Tensilon tensile tester at a pulling speed of 300 mm / min in the 180 ° direction.

[Evaluation method of holding power]
One adhesive surface of the adhesive tape is lined with a 25 μm-thick polyethylene terephthalate film and cut into a length of 20 mm × 100 mm. A stainless steel plate having a clean and smooth surface under an atmosphere of 23 ° C. and 50% RH ( No. 360 water-resistant polishing paper (hairline polishing treatment) is placed on the surface so that the pasting area is 20 mm × 20 mm, and the upper surface is reciprocated once by a 2 kg roller, and they are pressure-bonded to each other in an environment of 23 ° C. A test piece was prepared by leaving it for a period of time.
The time from when a load of 1 kg was applied to the pressure-sensitive adhesive tape in an environment of 70 ° C. with the stainless steel plate constituting the test piece being fixed was measured until the pressure-sensitive adhesive tape dropped from the stainless steel plate. When the adhesive tape did not fall after 24 hours or more, “> 24” was indicated.

[Evaluation method of shear adhesive strength]
The adhesive tape cut to 20 mm width x 20 mm length is pasted on the surface of a clean and smooth stainless steel plate 1 (hairline polishing treatment with # 360 water-resistant abrasive paper) at 23 ° C. and 50% RH atmosphere. Is pasted so that the pasting area becomes 20 mm × 20 mm, and the opposite surface is pasted on the surface of the clean and smooth stainless steel plate 2 (hairline polishing treatment with No. 360 water-resistant abrasive paper) so that the pasting area becomes 20 mm × 20 mm. They were pressure-bonded by reciprocating once with a 5 kg roller, and left to stand in an environment of 23 ° C. for 24 hours to prepare test pieces.
With the stainless steel plate 1 constituting the test piece fixed, using a Tensilon tensile tester, the stainless steel plate 2 was pulled at a speed of 300 mm / min in the shearing direction of the adhesive tape under an atmosphere of 23 ° C. and 50% RH. Shear adhesion was measured.

[Evaluation method of split adhesion]
The pressure-sensitive adhesive tape cut into 20 mm width × 20 mm length is placed on the surface of a clean and smooth aluminum plate 1 (A1050) at 23 ° C. and 50% RH so that the application area is 20 mm × 20 mm. Affixed to the surface of the clean and smooth aluminum plate 2 (A1050) so that the affixed area was 20 mm × 20 mm, and then reciprocated with a 5 kg roller to make them pressure-bonded at 23 ° C. A test piece was prepared by leaving it for 24 hours in the above environment.
With the aluminum plate 1 constituting the test piece fixed, using a Tensilon tensile tester, the aluminum plate 2 was pulled at a speed of 300 mm / min in the splitting direction of the adhesive tape under an atmosphere of 23 ° C. and 50% RH. The split adhesion was measured.

[Removability]
After sticking the 10 mm wide x 60 mm long adhesive tape to a clean and smooth stainless steel plate with a 10 mm wide x 10 mm long gripping hand protruding, the opposite surface is also cleaned into a clean and smooth stainless steel plate The test piece was affixed and pressured one reciprocating on the roller while applying a 2 kg load. After pasting, it was left for 3 days in an atmosphere of 23 ° C. and 50% RH, and at 23 ° C. and 50% RH, the grip portion of the adhesive tape was stretched by hand in the horizontal direction of the adhesive tape at a speed of about 300 mm / min.
The degree of adhesive remaining on the adherend after the adhesive tape was cut and the adhesive tape was peeled out was evaluated visually according to the following criteria.
(Double-circle): It peeled off neatly 3 times.
○: The film was peeled off twice, but the tape was cut once. The area of the adhesive tape remaining without stretching was 1/5 or less of the initial application area.
Δ: The film was peeled off twice, but the tape was cut once. The area of the adhesive tape that remained without stretching was 1/5 or more of the initial application area.
X: The adhesive tape could not be peeled off. Or, the tape was cut twice or more.

[Heat-resistant removability]
After sticking the 10 mm wide x 60 mm long adhesive tape to a clean and smooth stainless steel plate with a 10 mm wide x 10 mm long gripping hand protruding, the opposite surface is also cleaned into a clean and smooth stainless steel plate The test piece was affixed and pressured one reciprocating on the roller while applying a 2 kg load. After pasting, leave at 60 ° C and 90% RH for 7 days, let cool for 3 hours at 23 ° C and 50% RH, and then grip the adhesive tape with your hand in the horizontal direction of the adhesive tape at 23 ° C and 50% RH. The film was stretched at a speed of 300 mm / min.
The degree of adhesive remaining on the adherend after the adhesive tape was cut and the adhesive tape was peeled out was evaluated visually according to the following criteria.
(Double-circle): It peeled off neatly 3 times.
○: The film was peeled off twice, but the tape was cut once. The area of the adhesive tape remaining without stretching was 1/5 or less of the initial application area.
Δ: The film was peeled off twice, but the tape was cut once. The area of the adhesive tape that remained without stretching was 1/5 or more of the initial application area.
X: The adhesive tape could not be peeled off. Or, the tape was cut twice or more.

Claims (8)

It is an adhesive tape with a resin base and an adhesive layer,
The resin substrate contains a vinyl aromatic block copolymer (A),
The pressure-sensitive adhesive used for the pressure-sensitive adhesive layer is a pressure-sensitive adhesive containing the vinyl aromatic block copolymer (B),
The vinyl aromatic block copolymer (B) in the adhesive layer includes a styrene-isoprene copolymer and a styrene-isoprene-styrene copolymer, and the styrene-isoprene copolymer and the styrene-isoprene-styrene copolymer. Having a structural unit represented by the following chemical formula (2) in a range of 12 to 60% by mass with respect to the total mass of
The stress at 50% elongation of the adhesive layer is 0.05 to 10.5 MPa, and the storage elastic modulus G ′ (23 ° C.) of the adhesive layer is 1.0 × 10 ^{5 to} 1.0 × 10 ⁷ Pa. Adhesive tape.

The pressure-sensitive adhesive tape according to claim 1, which has a shear adhesive strength of 0.5 to 2.5 MPa. The pressure-sensitive adhesive tape according to claim 1 or 2, wherein the peel adhesive strength is 20 N / 20 mm or more. 2. The vinyl aromatic block copolymer (A) is one or more kinds of copolymers selected from block copolymers of an aromatic vinyl compound (a1) and a conjugated diene compound (a2). The adhesive tape of any one of -3. The pressure-sensitive adhesive tape according to claim 4, wherein the aromatic vinyl compound (a1) is styrene. The pressure-sensitive adhesive tape according to claim 4 or 5, wherein the conjugated diene compound (a2) is isoprene, butadiene, ethylene butylene, or ethylene propylene. Adhesive tape according to any one of claims 1 to 6, the adhesive used for the adhesive layer contains a tackifier resin. The pressure-sensitive adhesive tape according to any one of claims 1 to 7 , wherein the pressure-sensitive adhesive tape is peeled off by being stretched in the horizontal direction of the pressure-sensitive adhesive tape when peeling from the adherend.