JP2017105878A - Adhesive tape and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive tape excellent in adhesive force and hardly deforming whole adhesive tape by an external force.SOLUTION: The invention solves the above described problem by an adhesive tape having an adhesive layer (B) on at least one surface side of a substrate (A), storage elastic modulus (E') thereof measured at temperature of 20°C and frequency of 10.0 Hz of 1.0×10Pa or more and storage elastic modulus (E') thereof measured at temperature of 60°C and frequency of 10.0 Hz of 1.0×10Pa or more and a ratio of thickness of the adhesive layer (B) to thickness of the substrate (A) [thickness of the adhesive layer (B)/thickness of the substrate (A)] of 1/100 to 30/100.SELECTED DRAWING: None

Description

  The present invention relates to an adhesive tape that can be used in various fields including, for example, a manufacturing scene of a display having a touch panel function.

  Adhesive tapes are widely known as means for joining two or more adherends, and are used in various fields including electronic devices and automobiles.

  In recent years, adhesive tapes are required to have various functions depending not only on the strength of the adhesive force but also on the application in which they are used. Sex etc. may be required.

  In addition, along with the downsizing and thinning of the electronic equipment and the like, the components constituting the electronic device are also being downsized or thinned, and the adherend fixed by the adhesive tape is also being thinned.

  Examples of the thin adherend include a sheet-like material such as an optical film and a piezoelectric film, for example, in the case of manufacturing information display devices such as a display. The use of adhesive tape is being considered.

  However, since conventional thin adhesive tapes are generally not sufficient in terms of adhesive strength, when they are used in the production scenes of electronic devices and the like, they may cause peeling over time.

  By the way, as a touch panel, a method using a transparent piezoelectric sheet in which electrodes are arranged on the surface of a piezoelectric film via an adhesive layer has been proposed (for example, unlike a conventional resistive film method and a capacitance method) (for example, (See Patent Document 1).

  Moreover, in the flat display, an adhesive sheet that is difficult to be deformed even when the surface of the display is pressed when the optical film is bonded, and the dent is easily recovered even when deformed is proposed (for example, see Patent Document 2). ).

  More specifically, as the pressure-sensitive adhesive sheet, a pressure-sensitive adhesive composition containing a base polymer containing at least one (meth) acrylic acid ester polymer, an acrylic crosslinking monomer, and a crosslinking initiator is crosslinked. There is known a pressure-sensitive adhesive sheet that defines a predetermined storage shear modulus and Tan δ at a predetermined frequency.

  However, in the conventional adhesive tape, for example, when a force is applied locally from the surface of the adherend such as the piezoelectric film or the optical film, the entire adhesive tape is greatly deformed to try to relieve the force. For this reason, the piezoelectric film and the optical film are not locally deformed, and as a result, a malfunction may be caused when the touch panel or a display including the touch panel is operated by pressing.

JP 2011-222679 A JP 2009-46620 A

  The problem to be solved by the present invention is to provide a pressure-sensitive adhesive tape that is excellent in adhesive force and is difficult to deform the entire pressure-sensitive adhesive tape by external force.

The inventor is an adhesive tape having an adhesive layer (B) on at least one surface side of the base material (A), and the storage elastic modulus (E ′) measured at a temperature of 20 ° C. and a frequency of 10.0 Hz. ₂₀ ) is 1.0 × 10 ⁷ Pa or more, the storage elastic modulus (E ′ ₆₀ ) measured at a temperature of 60 ° C. and a frequency of 10.0 Hz is 1.0 × 10 ⁶ Pa or more, and The ratio of the thickness of the pressure-sensitive adhesive layer (B) to the thickness of the material (A) [the thickness of the pressure-sensitive adhesive layer (B) / the thickness of the base material (A)] is 1/100 to 30/100. The said subject was solved by the adhesive tape characterized by these.

  Since the pressure-sensitive adhesive tape of the present invention is excellent in adhesive force, for example, even when used for joining thin or small parts, it is difficult to cause peeling over time. Moreover, since the adhesive tape of the present invention is not easily deformed by an external force, it is possible to effectively prevent malfunction of a touch panel device or various operation devices that can be operated by pressing, for example.

The pressure-sensitive adhesive tape of the present invention is a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer (B) on at least one surface side of the substrate (A), and its storage elastic modulus (measured at a temperature of 20 ° C. and a frequency of 10.0 Hz). E ′ ₂₀ ) is 1.0 × 10 ⁷ Pa or more, the storage elastic modulus (E ′ ₆₀ ) measured at a temperature of 60 ° C. and a frequency of 10.0 Hz is 1.0 × 10 ⁶ Pa or more, and The ratio of the thickness of the pressure-sensitive adhesive layer (B) to the thickness of the base material (A) [thickness of the pressure-sensitive adhesive layer (B) / thickness of the base material (A)] is 1/100 to 30/100. It is characterized by being.

  Although the pressure-sensitive adhesive tape of the present invention is a pressure-sensitive adhesive tape that can bond the adherend with sufficient adhesive force even when it is thin, for example, stress such as indentation load or bending against the film- or sheet-like adherend or pressure-sensitive adhesive tape. Even when the is added, it is difficult to deform, and malfunction of the information display device including the touch panel device can be prevented.

As an embodiment of the pressure-sensitive adhesive tape of the present invention, one in which the pressure-sensitive adhesive layer (B) is laminated on one side or both sides of the substrate (A) can be mentioned. As the pressure-sensitive adhesive tape of the present invention, the storage elastic modulus (E ′ ₂₀ ) measured at a temperature of 20 ° C. and a frequency of 10.0 Hz is 1.0 × 10 6 in any of the so-called single-sided pressure-sensitive adhesive tape and double-sided pressure-sensitive adhesive tape. ^An adhesive tape having a storage elastic modulus (E ′ ₆₀ ) of 7 × 10 ⁶ Pa or more measured at a temperature of 60 ° C. and a frequency of 10.0 Hz is used. Thereby, the adhesive tape with which the whole adhesive tape cannot change easily with local external force can be obtained.

The adhesive tape has a storage elastic modulus (E ′ ₂₀ ) of 3.0 × 10 ⁷ Pa or more and a storage elastic modulus (E ′ ₆₀ ) of 3.0 × 10 ⁶ Pa or more. Preferably, the storage elastic modulus (E ′ ₂₀ ) is 1.0 × 10 ⁸ Pa or more and the storage elastic modulus (E ′ ₆₀ ) is 1.0 × 10 ⁷ Pa or more. More preferably, the storage elastic modulus (E ′ ₂₀ ) is 1.0 × 10 ⁹ Pa or more and the storage elastic modulus (E ′ ₆₀ ) is 1.0 × 10 ⁸ Pa or more. More preferably, is used. By using an adhesive tape having a storage elastic modulus in the above range, even when stress such as indentation load or bending is applied, it is difficult to be deformed, and malfunction of an information display device equipped with a touch panel device can be prevented. It can be effectively prevented.

  By the way, the adhesive tape generally has a tendency for the adhesive strength to decrease when the thickness of the pressure-sensitive adhesive layer is reduced. In addition, the pressure-sensitive adhesive layer generally has a lower elastic modulus than the base material (A). Therefore, when the thickness is increased, the entire pressure-sensitive adhesive tape tends to be easily deformed by a local external force. is there.

  The present invention sets the storage elastic modulus of the entire pressure-sensitive adhesive tape as described above, and controls the thickness of the base material (A) and the pressure-sensitive adhesive layer (B) so as to satisfy a specific relationship. It is possible to obtain a pressure-sensitive adhesive tape that is excellent in resistance to deformation of the whole pressure-sensitive adhesive tape by local external force.

  In the pressure-sensitive adhesive tape of the present invention, the ratio of the thickness of the pressure-sensitive adhesive layer (B) to the thickness of the base material (A) [thickness of the pressure-sensitive adhesive layer (B) / base material] The thickness of (A)] is 1/100 to 30/100. Especially, it is preferable to use what the [adhesive layer (B) thickness / base material (A) thickness] is 2 / 100-25 / 100 as said adhesive tape. It is more preferable to use a material having a thickness of ˜20 / 100 in order to obtain a pressure-sensitive adhesive tape that is more excellent in adhesive force even if it is thin and that the entire pressure-sensitive adhesive tape is hardly deformed by external force.

  As said adhesive tape, while satisfy | filling the said ratio, it is preferable to use a thing with a thickness of 5 micrometers-100 micrometers as said base material (A), and it is thin to use a thing with a thickness of 10 micrometers-80 micrometers. Is more preferable for obtaining a pressure-sensitive adhesive tape that is more excellent in adhesive force and is difficult to deform the entire pressure-sensitive adhesive tape due to external force.

  Moreover, as said adhesive tape, while satisfy | filling the said ratio, it is preferable to use that the thickness of the adhesive layer (B) provided in the single side | surface of the said base material (A) is 0.5 micrometer-15 micrometers, It is more preferable to use those having a thickness of 1.0 μm to 12 μm in order to obtain a pressure-sensitive adhesive tape that is more excellent in adhesive force even if it is thin, and that the entire pressure-sensitive adhesive tape is hardly deformed by external force.

  Further, the pressure-sensitive adhesive tape of the present invention can be suitably used for bonding various adherends. For example, from the viewpoint of effectively preventing malfunction of a touch panel device or various operation devices that can be operated by pressing, the pressure-sensitive adhesive tape A thinner layer is preferable because the amount of deformation is reduced.

  On the other hand, when the layer made of the adhesive tape becomes thin, there is a tendency that the adhesive force tends to decrease, or bubbles are caught between the layer made of the adhesive tape and the adherend in the bonding process of the adherend. May cause. In particular, when a high-rigidity object is used as the adherend, the above-described problem may be significant.

  As the pressure-sensitive adhesive tape of the present invention, even when a highly rigid adherend such as a glass plate is used, in order to achieve a sufficient adhesive force while effectively preventing the occurrence of the above problems, The thickness of the adhesive layer (B) is preferably 1 μm to 15 μm, and the total thickness of the adhesive tape including the base material (A) and the adhesive layer (B) is 25 μm to 100 μm, more preferably the adhesive layer (B). The thickness of the pressure-sensitive adhesive tape including the base material (A) and the pressure-sensitive adhesive layer (B) is 40 μm to 90 μm, more preferably the pressure-sensitive adhesive layer (B) has a thickness of 3 μm to 12 μm. The thing whose total thickness of the adhesive tape containing 8 micrometers and the said base material (A) and an adhesive layer (B) is 60 micrometers-85 micrometers can be used.

  On the other hand, if a flexible material such as a film is used as the adherend, the thickness of the pressure-sensitive adhesive layer (B) is preferably 0.5 μm to 10 μm, and the substrate (A) and the pressure-sensitive adhesive layer (B ) And the adhesive layer (B) has a thickness of 0.8 to 8 μm, and preferably includes the substrate (A) and the adhesive layer (B). The total thickness of the pressure-sensitive adhesive tape is 7 μm to 40 μm, more preferably, the thickness of the pressure-sensitive adhesive layer (B) is 1 μm to 6 μm, and the total thickness of the pressure-sensitive adhesive tape includes the substrate (A) and the pressure-sensitive adhesive layer (B). Use of a material having a thickness of 10 μm to 30 μm is suitable for achieving sufficient adhesive force while effectively preventing the above problems.

As the base material constituting the adhesive tape of the present invention (A), and the temperature 20 ° C. and the measured storage modulus at a frequency 10.0Hz (E _'20) is 2.0 × ¹⁰ 7 Pa or more, In addition, the storage elastic modulus of the pressure-sensitive adhesive tape described above is that the storage elastic modulus (E ′ ₆₀ ) measured at a temperature of 60 ° C. and a frequency of 10.0 Hz is 2.0 × 10 ⁶ Pa or more. As a result, it is preferable to obtain a pressure-sensitive adhesive tape that is more excellent in adhesive force even if it is thin, and that the entire pressure-sensitive adhesive tape is hardly deformed by external force.

As the base material (A), the storage elastic modulus (E ′ ₂₀ ) is 1.0 × 10 ⁸ Pa or more, and the storage elastic modulus (E ′ ₆₀ ) is 1.0 × 10 ⁷ Pa or more. More preferably, the storage elastic modulus (E ′ ₂₀ ) is 1.0 × 10 ⁹ Pa or more, and the storage elastic modulus (E ′ ₆₀ ) is 1.0 × 10 ⁸ Pa or more. It is more preferable to use what is. By using a substrate having a storage elastic modulus in the above range, for example, even when stress such as indentation load or bending is applied, it is difficult to deform, and malfunction of an information display device equipped with a touch panel device can be prevented. It can be effectively prevented.

  As the substrate (A), among those satisfying the storage elastic modulus, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, cellophane, diacetylcellulose, triacetylcellulose, acetylcellulose butyrate, polychlorinated Vinyl, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyetheretherketone, polyethersulfone, polyetherimide, polyimide, fluororesin, nylon, acrylic resin, A resin base material including polyurethane, acrylic acrylate, urethane acrylate, epoxy acrylate, or the like can be used.

  As the base material (A), it is even more excellent to use a material having a functional group (for example, a hydroxyl group) capable of reacting with a functional group (for example, an isocyanate group) or the like of the pressure-sensitive adhesive layer (B) described later. It is more preferable for expressing adhesive strength and preventing peeling with time.

  Moreover, as said base material (A), the active energy ray hardened | cured material hardened | cured by irradiating an active energy ray can be used suitably, and the active energy ray hardened | cured material which has a urethane bond can be used. preferable. In the active energy ray curing reaction, a heating and curing step is not usually required, so that the substrate (A) can be produced in a relatively short time.

  Moreover, when reaction with the said functional group (for example, hydroxyl group) which can react with the functional group (for example, isocyanate group) etc. which the said adhesive layer (B) may have is a heat reaction type, it depends on active energy ray reaction. It is preferable because the production process of the base material (A) and the production process of the pressure-sensitive adhesive tape for forming a bond between the base material (A) and the pressure-sensitive adhesive layer (B) can be selectively performed.

  As a functional group which the said base material (A) may have, a heat reaction type functional group is mentioned, for example, For example, a hydroxyl group etc. are mentioned.

  Moreover, as a functional group which the said adhesive layer (B) may have, a heat-reactive functional group is mentioned, It is preferable that it is reactive functional groups, such as an isocyanate group.

  As the substrate (A), it is preferable to use polyurethane, epoxy resin, acrylic acrylate or the like having an active energy ray-curable functional group such as acryloyl group and a heat-reactive functional group in the molecule, such as acryloyl group. It is more preferable to use polyurethane having an active energy ray-curable functional group and a heat-reactive functional group in the molecule.

  Examples of the polyurethane having an active energy ray-curable functional group such as the acryloyl group and a heat-reactive functional group include a polyurethane having an isocyanate group (a1 ′) and a functional group capable of reacting with the isocyanate group (for example, a hydroxyl group). Etc.) can be suitably used as the polyurethane (a1) which is a reaction product with the (meth) acryl monomer.

  As the polyurethane (a1 ′) having an isocyanate group, a reaction product of a polyol (a1-1) and a polyisocyanate (a1-2) can be preferably used.

  As said polyol (a1-1), a polycarbonate polyol, a polyester polyol, a polyether polyol etc. can be used, for example. Especially, as said polyol (a1-1), after irradiating an active energy ray, when obtaining the base material (A) provided with the said storage tension elastic modulus of the said suitable range, a polycarbonate polyol and a polyester polyol are individual. Or it is preferable to use 2 or more types in combination, and it is preferable to use a combination of polycarbonate polyol and polyester polyol.

  As said polycarbonate polyol, what is obtained by making carbonate ester and / or phosgene react with the low molecular polyol mentioned later, for example can be used.

  As the carbonate ester, for example, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like can be used.

  Examples of the low molecular polyol that can react with the carbonate ester or phosgene include, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene, and the like. Propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexane Diol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol 2-methyl-1,3-propanediol Neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octane Diol, 1,4-cyclohexanedimethanol, hydroquinone, resorcin, bisphenol A, bisphenol F, 4,4′-biphenol, and the like can be used.

  Examples of the polyester polyol that can be used for the polyol (a1-1) include those obtained by esterifying low molecular weight polyols and polycarboxylic acids, and ring-opening polymerization reactions of cyclic ester compounds such as ε-caprolactone. Polyesters obtained by the above, copolymerized polyesters thereof, and the like can be used.

  Examples of the low molecular weight polyol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and 1,3-butane having a molecular weight of about 50 to 300. Aliphatic alkylene glycols such as diols, cyclohexanedimethanol and the like can be used.

  Examples of the polycarboxylic acid that can be used in the production of the polyester polyol include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, and naphthalene dicarboxylic acid. Aromatic dicarboxylic acids such as acids, and anhydrides or esterified products thereof can be used.

  Moreover, polyether polyol can also be used as said polyol (a1-1). As the polyether polyol, for example, one obtained by addition polymerization of alkylene oxide using one or more compounds having two or more active hydrogen atoms as an initiator can be used.

  Moreover, as said polyol (a1-1), another polyol other than what was mentioned above can be used. As said other polyol, an acrylic polyol etc. are mentioned, for example.

  Moreover, as said polyisocyanate (a1-2), alicyclic polyisocyanate, aliphatic polyisocyanate, aromatic polyisocyanate etc. can be used, and it is preferable to use alicyclic polyisocyanate.

  Examples of the alicyclic polyisocyanate include isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 4,4′-dicyclohexylmethane diisocyanate, 2,4- and / or 2,6-methylcyclohexane diisocyanate, cyclohexyl. Silylene diisocyanate, methylcyclohexylene diisocyanate, bis (2-isocyanatoethyl) -4-cyclohexylene-1,2-dicarboxylate and 2,5- and / or 2,6-norbornane diisocyanate, dimer acid diisocyanate, bicycloheptane Triisocyanate etc. can be used individually or in combination of 2 or more types.

  As a method for producing the polyurethane (a1 ′) having an isocyanate group by reacting the polyol (a1-1) and the polyisocyanate (a1-2), for example, the polyol (a1-1) charged in a reaction vessel is used. In addition, after removing moisture by heating under normal pressure or reduced pressure, the polyisocyanate (a1-2) is supplied in batch or divided and reacted.

  Reaction of the said polyol (a1-1) and the said polyisocyanate (a1-2) is equivalent ratio of the isocyanate group which the said polyisocyanate (a1-2) has, and the hydroxyl group which the said polyol (a1-1) has ( [NCO / OH equivalent ratio] is preferably in the range of 1.1 to 20.0, more preferably in the range of 1.1 to 13.0, and 1.1 to 5. More preferably, it is carried out in the range of 0, particularly preferably in the range of 1.5 to 3.0.

  The reaction conditions (temperature, time, etc.) between the polyol (a1-1) and the polyisocyanate (a1-2) may be appropriately set in consideration of various conditions such as safety, quality, and cost, and are not particularly limited. For example, the reaction temperature is preferably in the range of 70 to 120 ° C., and the reaction time is preferably in the range of 30 minutes to 5 hours.

  When the polyol (a1-1) and the polyisocyanate (a1-2) are reacted, for example, a tertiary amine catalyst or an organometallic catalyst can be used as a catalyst as necessary. .

  The reaction may be performed in a solvent-free environment or in the presence of an organic solvent.

  Examples of the organic solvent include ester solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl butyl ketone, and cyclohexanone; and ether esters such as methyl cellosolve acetate and butyl cellosolve acetate. Solvents, aromatic hydrocarbon solvents such as toluene and xylene, amide solvents such as dimethylformamide and dimethylacetamide, and the like can be used alone or in combination of two or more. The organic solvent may be removed during the production of the polyurethane (a1 ') or after the production of the polyurethane (a1') by an appropriate method such as heating under reduced pressure or drying at normal pressure.

  As the polyurethane (a1 ′) having an isocyanate group obtained by the above method, a polyurethane having a softening temperature of 40 ° C. or higher is preferably used, and a polyurethane having a softening temperature of 50 ° C. or higher is more preferably used. . In addition, the said softening temperature refers to the value measured based on JISK2207. The upper limit of the softening temperature is preferably 100 ° C. or less.

  The polyurethane (a1) that can be used in the present invention is a polyurethane (a1 ′) having an isocyanate group obtained by the above method, and a (meth) acrylic monomer having a functional group capable of reacting with the isocyanate group. Can be made to react. Specifically, the polyurethane (a1) can be produced by mixing and reacting the polyurethane (a1 ′) obtained by the above method or an organic solvent solution thereof with the (meth) acrylic monomer. .

  As the (meth) acrylic monomer, for example, a (meth) acrylic monomer having a hydroxyl group, an amino group, a carboxyl group, a mercapto group, or the like as a functional group capable of reacting with an isocyanate group can be used. It is preferable to use a (meth) acrylic monomer having an amino group.

  Specific examples of the (meth) acrylic monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth). Acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, butanediol mono (meth) acrylate, caprolactone modified product of 2-hydroxyethyl (meth) acrylate, glycidol di (meth) acrylate Dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and the like can be used alone or in combination of two or more thereof.

  Among these, as the (meth) acrylic monomer, for example, irradiation with active energy rays such as infrared rays, visible rays, ultraviolet rays, X-rays, electron beams, α rays, β rays, γ rays, sunlight, etc. It is preferable to use 2-hydroxyethyl acrylate in order to further improve the mechanical strength of the curable and finally obtained substrate (A). In the present invention, “(meth) acrylate” refers to one or both of acrylate and methacrylate.

  The (meth) acrylic monomer is preferably used in a range of 5 to 20 parts by mass with respect to 100 parts by mass of the polyurethane (a1 ′), and used in a range of 5 to 15 parts by mass. More preferably.

  When the polyurethane (a1 ′) and the (meth) acrylic monomer are reacted, a urethanization catalyst can be used as necessary. The urethanization catalyst can be appropriately added at any stage of the urethanization reaction. The urethanization reaction is preferably performed until the isocyanate group content (%) becomes substantially constant.

  Examples of the urethanization catalyst include nitrogen-containing compounds such as triethylamine, triethylenediamine and N-methylmorpholine, organometallic salts such as potassium acetate, zinc stearate and stannous octylate, and organometallic compounds such as dibutyltin dilaurate. Etc. can be used.

  In the polyurethane (a1) having a polymerizable unsaturated double bond obtained by the above method, radical polymerization of a polymerizable unsaturated double bond such as a (meth) acryloyl group proceeds when irradiated with active energy rays. Harden.

  When the base material (A) is produced using the polyurethane (a1), the active energy ray curing containing the radical polymerization initiator (a2) and other active energy ray-curable compound resins together with the polyurethane (a1). Sex compositions can be used.

  As the radical polymerization initiator (a2), known ones can be used, and examples thereof include a photopolymerization initiator and a peroxide, and a photopolymerization initiator is preferable for maintaining good productivity and the like. .

  Examples of the photopolymerization initiator (a2) include conventionally known photopolymerization initiators such as alkylphenone photopolymerization initiators such as benzophenone, camphorquinone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, and titanocene photopolymerization initiators. Can be used.

  Examples of commercially available photopolymerization initiators (hereinafter referred to as trademarks) include benzophenone, 4,4-bis (diethylamino) benzophenone, 2,4,6-trimethylbenzophenone, methyl orthobenzoylbenzoate, 4-phenylbenzophenone, Thioxanthones such as t-butylanthraquinone, 2-ethylanthraquinone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone; diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1 -On (for example, Darocur 1173 manufactured by Ciba Specialty Chemicals), benzyldimethyl ketal, 1-hydroxycyclohexyl-phenylketone (for example, Irgacure manufactured by Ciba Specialty Chemicals) 84), 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one (for example, Irgacure 2959 manufactured by Ciba Specialty Chemicals), 2-methyl- Acetophenones such as 2-morpholino (4-thiomethylphenyl) propan-1-one (eg, Irgacure 907 manufactured by Ciba Specialty Chemicals) and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone Benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether; 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4 -Birds Acylphosphine oxides such as tilpentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; methylbenzoylformate (for example, BYCURE 55 manufactured by Stower), 1,7-bisacridini Luheptane, 9-phenylacridine, Quantacure (manufactured by International Bio-Synthetics), Kaiacure MBP (manufactured by Nippon Kayaku Co., Ltd.), Esacure BO (manufactured by Fratelli Lamberti), Trigonal 14 (manufactured by Akzo) ), Irgacure (made by Ciba Geigy), Darocure (made by the company), Speedcure (made by the company), Darocur 1173 and Fi-4 mixture (made by Eastman), etc., alone or in combination. be able to.

  As the photopolymerization initiator, it is preferable to use Irgacure 184, Irgacure 651, or the like that can be quickly cured by irradiating active energy rays such as ultraviolet rays.

  The radical polymerization initiator (a2) is preferably used in the range of 0.5 to 5 parts by mass with respect to 100 parts by mass of the polyurethane (a1), and used in the range of 1 to 3 parts by mass. More preferably.

  Moreover, as said other active energy ray hardening compound, a well-known polyfunctional (meth) acrylate compound can be used as needed.

  The “polyfunctional” as used in the present invention refers to having two or more polymerizable unsaturated double bonds in the molecule.

  Examples of the polyfunctional (meth) acrylate compound include polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol hydroxypivalate di (meth) acrylate, and ditrimethylolpropane tetra (meth) acrylate. , Neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, etc. ) Those having 2 to 4 polymerizable unsaturated double bonds, such as (meth) acrylate esters of sugar alcohols such as acrylate and sorbitol, are used alone or in combination of two or more. Rukoto can.

  The polyfunctional (meth) acrylate compound is preferably used in the range of 5 to 50 parts by mass with respect to 100 parts by mass of the polyurethane (a1), and used in the range of 10 to 40 parts by mass. More preferably.

  As said base material (A), what contains an additive as needed other than the said polyurethane (a1) can be used.

  Examples of the additive include a silane coupling agent, a phosphoric acid additive, an acrylate additive, a tackifier, a light stabilizer, an anti-aging agent, a release modifier, a plasticizer, a softener, a filler, a colorant, A surfactant or the like can be used.

  If the said active energy ray curable composition is used for the said base material (A), for example, it will apply | coat to the surface of a peeling liner, it will dry etc. as needed, and an active energy ray will be irradiated. It can be manufactured by the step [1].

  Examples of the coating include gravure coating method, roll coating method, comma coating method, air knife coating method, kiss coating method, spray coating method, transfer coating method, spinner coating method, wheeler coating method, brush coating method, and betacoating by silk screen. It can be performed by a method such as a method, a wire bar coating method, a flow coating method, an offset printing method, a letterpress printing method, or an extrusion molding method.

  You may perform the said drying, when using what contains a solvent as the said active energy ray curable composition, for example. The drying may be appropriately set in consideration of various conditions such as safety, quality, and cost, and is not particularly limited. For example, the drying temperature is in the range of 60 ° C to 120 ° C, and the drying time is 30 seconds to 10 minutes. It is preferable to carry out within the range in order to produce a substrate that is not cured with active energy rays (uncured state).

  Next, as a method of irradiating the active energy ray to the substrate that is not cured with the active energy ray (uncured state), for example, in the case of ultraviolet rays, a low pressure mercury lamp, a high pressure mercury lamp, Examples include high pressure mercury lamp, metal halide lamp, electrodeless lamp (fusion lamp), chemical lamp, black light lamp, mercury-xenon lamp, short arc lamp, helium / cadmium laser, argon laser, sunlight, LED, etc. .

  The active energy ray may be irradiated to the base material in a state where the active energy ray is not cured, but in addition to being able to directly irradiate the base material, it is irradiated after providing the pressure-sensitive adhesive layer (B). You can also. In this case, there may be a release liner attached to the pressure-sensitive adhesive layer (B). In addition, it is necessary to attach a release liner for the purpose of preventing oxygen damage when the substrate undergoes a curing reaction with active energy rays, or to apply a cut filter that is suitable for the purpose of irradiating active energy rays while blocking a specific wavelength. It can also be irradiated. Furthermore, if you want to obtain a smoother shape, stick a release liner with high smoothness, or if you want to form a three-dimensional shape such as irregularities or curved surfaces, stick a release liner with the shape you want to form. Can also be irradiated.

  Examples of the active energy rays include ionizing radiation such as ultraviolet rays, electron beams, α rays, β rays, and γ rays.

  As the base material (A) obtained by the above method, it is preferable to use a substrate having a total light transmittance of 80% or more and a haze of 1.0% or less, and a total light transmittance of 90% or more, It is more preferable to use one having a haze of 0.5% or less. By using a substrate having a total light transmittance within the above range, excellent transparency of a display equipped with a touch panel device or the like can be maintained.

  As the base material (A), for example, if the resin base material is used, a base material made only of the resin base material may be used, but the adhesiveness with the pressure-sensitive adhesive layer (B) is improved. In order to improve, the thing which has a thin primer layer on the surface of the said resin base material can be used.

  Moreover, as said base material (A), in order to further improve the adhesiveness with the pressure-sensitive adhesive layer (B), surface roughening treatment, corona discharge treatment, chromic acid treatment by a sandblast method or a solvent treatment method, etc. Those subjected to surface treatment such as flame treatment, hot air treatment, ozone treatment or ultraviolet irradiation treatment, and surface oxidation treatment can also be used.

<Adhesive layer>
The pressure-sensitive adhesive layer (B) constituting the pressure-sensitive adhesive tape of the present invention is laminated directly or via another layer on one side or both sides of the substrate (A).

  As the pressure-sensitive adhesive layer (B), it is preferable to use a layer having a thickness of 0.5 μm to 15 μm, and using a layer having a thickness of 1.0 μm to 12 μm is the range described above for the storage elastic modulus of the pressure-sensitive adhesive tape. As a result, it is more preferable to obtain a pressure-sensitive adhesive tape that is more excellent in adhesive force even if it is thin, and that the entire pressure-sensitive adhesive tape is difficult to be deformed by external force. In addition, the said thickness points out the thickness of the adhesive layer (B) provided in the single side | surface of the said base material (A), and is the total thickness of the thickness of the adhesive layer (B) provided in the both surfaces side. It does not point to.

The pressure-sensitive adhesive layer (B) has an elastic modulus (G ′ ₂₀ ) measured at a temperature of 25 ° C. and a frequency of 1.0 Hz in the range of 1.0 × 10 ^{4 to} 5.0 × 10 ⁵ Pa, and The tensile modulus of elasticity (G ′ ₆₀ ) measured at a temperature of 60 ° C. and a frequency of 1.0 Hz is 1.0 × 10 ⁶ Pa or more, and the storage modulus of the adhesive tape is set in the above-described range. It is more preferable to obtain an adhesive tape that can be easily deformed by an external force.

  The pressure-sensitive adhesive layer (B) preferably has a gel fraction of 30% by mass to 80% by mass, more preferably 30% by mass to 70% by mass, and 30% by mass to 60% by mass. Is more preferable. The pressure-sensitive adhesive layer having a gel fraction in the above range is particularly difficult to cause peeling from the adherend, and higher adhesion can be obtained by increasing the adhesion area following the unevenness of the adherend surface. . The gel fraction in the present invention is expressed as a percentage of the original mass by immersing the cured pressure-sensitive adhesive layer in toluene, measuring the mass after drying of the insoluble matter remaining after standing for 24 hours, and the original mass. Is.

  The pressure-sensitive adhesive layer (B) preferably has a total light transmittance of 80% or more and a haze of 1.0% or less, a total light transmittance of 90% or more and a haze of 0.00. It is more preferable to use what is 5% or less. By using an adhesive layer having a total light transmittance within the above range, excellent transparency of a display equipped with a touch panel device can be maintained.

  The pressure-sensitive adhesive layer (B) can be formed by applying or bonding a pressure-sensitive adhesive. As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a rubber pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, or the like can be used.

  Of these, the use of an acrylic pressure-sensitive adhesive containing an acrylic polymer as the pressure-sensitive adhesive makes it easy to obtain adhesion with the base material (A), thereby realizing higher adhesive strength. Moreover, since transparency, a weather resistance, etc. can be improved further, it is preferable.

  As said acrylic polymer, what is obtained by superposing | polymerizing a (meth) acryl monomer (b1) can be used. As said (meth) acryl monomer (b1), (meth) acrylate is mentioned, for example, It is preferable to use what contains the (meth) acrylate which has a C2-C14 alkyl group.

  Examples of the (meth) acrylate having an alkyl group having 2 to 14 carbon atoms include ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, t-butyl acrylate, and n-hexyl. Acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, isodecyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec -Butyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate Rate, n- octyl methacrylate, isooctyl methacrylate, 2-ethylhexyl methacrylate, isononyl methacrylate, isodecyl methacrylate, lauryl methacrylate.

  Among the above (meth) acrylates, it is preferable to use an alkyl (meth) acrylate having an alkyl group having 4 to 14 carbon atoms, and an alkyl acrylate having an alkyl group having 4 to 9 carbon atoms. More preferably, is used.

  As the alkyl acrylate having an alkyl group having 4 to 9 carbon atoms, n-butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, and ethyl acrylate are more preferable because it is easy to ensure suitable adhesive strength. .

  The (meth) acrylate having an alkyl group having 2 to 14 carbon atoms can be used in the range of 90 to 99 parts by mass with respect to 100 parts by mass of the total amount of the (meth) acrylic monomer. Even when the agent layer is thin, it is more preferable because a suitable adhesive force is easily secured.

  As said acrylic polymer, what has polar groups, such as a hydroxyl group and an alkoxy group, can be used, for example.

  The acrylic polymer can be produced, for example, by polymerizing a (meth) acrylic monomer having a polar group such as a hydroxyl group.

  Examples of the (meth) acrylate monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, hydroxypropyl (meth) acrylate, Examples include caprolactone-modified (meth) acrylate, polyethylene glycol mono (meth) acrylate, and polypropylene glycol mono (meth) acrylate. Among these, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxyhexyl (meth) acrylate are preferably used.

  Examples of the (meth) acrylate monomer having an alkoxy group include 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-methoxytriethylene glycol acrylate, 3-methoxypropyl acrylate, and 3-methoxy acrylate. Examples include ethoxypropyl, 4-methoxybutyl acrylate, 4-ethoxybutyl acrylate and the like. Among these, the use of 2-methoxyethyl acrylate and 2-ethoxyethyl acrylate can impart more excellent cohesive force to the pressure-sensitive adhesive layer.

  The (meth) acrylic monomer having a hydroxyl group or an alkoxy group is used in the range of 5% by mass to 95% by mass with respect to the total amount of the (meth) acrylic monomer used for the production of the acrylic polymer. Is preferably used in the range of 10% by mass to 90% by mass, more preferably in the range of 20% by mass to 90% by mass, so that the cohesive force and holding force can be easily adjusted to a suitable range. Even if it is thin, it is more preferable because excellent adhesiveness is easily obtained.

  Moreover, you may use the vinyl monomer (b2) which has a carboxyl group for manufacture of the said acrylic polymer. However, when the adherend is a metal surface or the like, it may cause problems such as corrosion. The vinyl monomer (b2) used when it can be determined that there is no adverse effect on the adherend is not particularly limited, but acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, acrylic acid dimer, ethylene Oxide modified succinic acrylate and the like can be used. When the vinyl monomer (b2) having a carboxyl group is used, it is preferable to use acrylic acid because of its high versatility.

  The vinyl monomer (b2) having a carboxyl group is used in an amount of 1% by mass or less based on the total amount of monomer components used in the production of the (meth) acrylic acid ester copolymer. In particular, the vinyl monomer having a carboxyl group (b2) is preferably used in a range of 0.5% by mass or less, more preferably 0.1% by mass or less, and not used. Is more preferable. Thereby, for example, even when the adherend is a metal surface or the like and the adhesive tape of the present invention is applied, corrosion can be sufficiently prevented.

  The acrylic polymer preferably has a molecular weight distribution (weight average molecular weight / number average molecular weight) of 10 to 50, more preferably 10 to 30, and still more preferably 10 to 20. By adjusting the molecular weight distribution (weight average molecular weight / number average molecular weight) of the (meth) acrylic acid ester copolymer to the above range, even if the pressure-sensitive adhesive layer is thin, the followability to the unevenness of the adherend is excellent, It is difficult to leave bubbles in the display screen portion, and high adhesion reliability to the adherend can be imparted.

In addition, the weight average molecular weight of the said (meth) acrylic acid ester copolymer points out the value measured by the gel permeation chromatograph (GPC). More specifically, it is a value obtained by measuring “SC8020” manufactured by Tosoh Corporation as a GPC measurement device, and measuring the polystyrene conversion value under the following GPC measurement conditions.
(GPC measurement conditions)
Sample concentration: 0.5% by mass (tetrahydrofuran solution)
Sample injection volume: 100 μL
・ Eluent: Tetrahydrofuran (THF)
・ Flow rate: 1.0 mL / min
Column temperature (measurement temperature): 40 ° C
Column: “TSKgel GMHHR-H” manufactured by Tosoh Corporation
・ Detector: Differential refraction

  As the pressure-sensitive adhesive, it is preferable to use a material containing a crosslinking agent in addition to the acrylic polymer in order to further increase the cohesive force.

  Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, chelate crosslinking agents, and the like.

  As the acrylic pressure-sensitive adhesive, in addition to the above-described components, other additives can be used as necessary.

  Examples of the additive include an ultraviolet absorber, a light stabilizer, an anti-aging agent, a release modifier, a tackifier, a plasticizer, a softener, a filler, a colorant (such as a pigment and a dye), and a surfactant. Can be used.

<Manufacturing method of adhesive tape>
The pressure-sensitive adhesive tape of the present invention has the thickness of the base material (A) on at least one surface side of the base material (A) after the base material (A) is manufactured through the step [1]. The thickness ratio of the pressure-sensitive adhesive layer (B) to [the thickness of the pressure-sensitive adhesive layer (B) / the thickness of the base material (A)] is in the range of 1/100 to 30/100. It can manufacture by passing through process [2] which provides (B).

  Examples of the step [2] include a step of transferring the pressure-sensitive adhesive layer (B) obtained by previously applying the pressure-sensitive adhesive to the surface of the release liner and drying.

  Moreover, as said process [2], the process of forming an adhesive layer (B) by apply | coating the said adhesive to the surface of the said base material (A), drying, etc. is mentioned.

  The pressure-sensitive adhesive tape of the present invention has a structure in which the physical property value and thickness of the base material (A) and the pressure-sensitive adhesive layer (B) are adjusted to a specific range and combined, so that even if it is thin, the adhesive force is further increased. Because it is excellent and the entire adhesive tape is not easily deformed by external force, for example, in a display terminal equipped with a touch panel and a piezoelectric film, when a pressing force is applied from the outside of the display, local stress is applied to the piezoelectric film. Can be added. Thereby, the malfunctioning of the operating device by a press can be prevented.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

Example 1
(Production of substrate (A-1))
100 parts by mass of a polyurethane composition (solid content 48% by mass) having an acryloyl group and a hydroxyl group, 14.5 parts by mass of Aronix M309 (manufactured by Toagosei Co., Ltd., trimethylolpropane triacrylate, solid content 100% by mass), "Irgacure 184" (manufactured by BASF Japan, photopolymerization initiator, 1-hydroxycyclohexyl phenyl ketone, solid content 100% by mass) 4.5 parts by mass and methyl ethyl ketone 30 parts by mass were stirred to obtain an activity with a solid content of 43% by mass An energy ray curable resin composition (A-1-1) was prepared.

Next, the thickness after drying the active energy ray-curable resin composition (A-1-1) on a release liner provided with a release layer made of a silicone compound on one side of a 75 μm thick polyethylene terephthalate film. Is applied at a temperature of 65 μm, dried at 75 ° C. for 5 minutes, and irradiated with an ultraviolet ray irradiation device (“F450” manufactured by Fusion UV Systems Japan Co., Ltd., lamp: 120 W / cm, H bulb). ^The base material (A-1) was formed by irradiating ultraviolet rays at ² .

(Preparation of adhesive)
In a reaction vessel equipped with a stirrer, reflux condenser, thermometer, dropping funnel and nitrogen gas inlet, 75 parts by mass of 2-methoxyethyl acrylate, 24 parts by mass of n-butyl acrylate, 1 mass of 2-hydroxyethyl acrylate Part and 0.22 parts by mass of 2,2′-azobisisobutylnitrile as a polymerization initiator were dissolved in 100 parts by mass of ethyl acetate, and after substitution with nitrogen, polymerization was carried out at 80 ° C. for 8 hours. Then, it diluted with ethyl acetate and obtained the adhesive composition of 45 mass% of solid content.
An acrylic pressure-sensitive adhesive was prepared by adding 0.08 parts by weight of Coronate HL (manufactured by Nippon Polyurethane Industry Co., Ltd., hexamethylene diisocyanate compound) to 100 parts by weight of the pressure-sensitive adhesive composition and stirring for 15 minutes.

(Production of adhesive tape)
To the release liner provided with a release layer made of a silicone compound on one side of a 75 μm thick polyethylene terephthalate film, the acrylic pressure-sensitive adhesive was applied so that the thickness of the pressure-sensitive adhesive layer after drying was 5 μm, The pressure-sensitive adhesive layer was prepared by drying at 80 ° C. for 5 minutes.

  Next, the pressure-sensitive adhesive layer was sequentially bonded to both surfaces of the base material (A-1) under a pressure condition of 4 kg / cm. Then, an adhesive tape having a total thickness of 75 μm was obtained by aging at 40 ° C. for 3 days. The gel fraction of the pressure-sensitive adhesive layer was 52% by mass. The gel fraction was determined based on the insoluble matter remaining after 24 hours of immersion in an adhesive layer (thickness 5 μm) obtained in the same manner as described above after curing at 40 ° C. for 3 days. Based on the mass after drying for 1 minute and the mass before soaking, the formula [mass of insoluble matter after soaking / mass of pressure-sensitive adhesive layer before soaking] × 100 was calculated.

(Comparative Example 1)
(Production of adhesive tape)
On the release liner provided with a release layer made of a silicone compound on one side of a 75 μm thick polyethylene terephthalate film, the acrylic adhesive was applied so that the thickness of the adhesive layer after drying was 75 μm, By drying at 80 ° C. for 5 minutes, an adhesive tape having a thickness of 75 μm without a core was prepared. In addition, the gel fraction of the adhesive layer measured by the method similar to the above was 52 mass%.

<Measuring method of dynamic viscoelastic E 'spectrum>
After bonding the adhesive tapes obtained in Examples and Comparative Examples so as to have a thickness of 150 μm, a test piece was punched into the shape of JIS K 7127 test piece type 5 using a dumbbell cutter.

Moreover, the thickness after drying the said active energy ray-curable resin composition (A-1-1) to the peeling liner by which the peeling layer which consists of a silicone compound was provided in the single side | surface of a 75-micrometer-thick polyethylene terephthalate film. After coating for 65 μm, drying at 75 ° C. for 5 minutes, bonding to a thickness of 130 μm, ultraviolet irradiation device (“F450” manufactured by Fusion UV Systems Japan Co., Ltd., lamp: 120 W / cm, H bulb ) Was irradiated with ultraviolet rays at an irradiation light quantity of 1000 mJ / cm ² and then punched into the shape of test piece type 5 of JIS K 7127 using a dumbbell cutter as a test piece.

  Using the test piece, a storage elastic modulus E ′ at 20 ° C. and 60 ° C. was measured with a dynamic viscoelasticity measuring device RSA-II (frequency 10.0 Hz, temperature rising rate 3 ° C./min) manufactured by Rheometrics. Got.

<Measuring method of dynamic viscoelastic G 'spectrum>
The storage elastic modulus at each temperature of the 5 μm thick adhesive layer of Example 1 and the 75 μm thick adhesive layer of Comparative Example 1 was measured by viscoelasticity testing machine (manufactured by T.A. Name: ARES-G2) is used to insert a test piece between parallel disks, which are the measurement unit of the tester, and measure the storage elastic modulus (G ′) at a temperature of 20 ° C. or 60 ° C. and a frequency of 1 Hz. did. As a test piece when measuring the storage elastic modulus of the pressure-sensitive adhesive layer, a plurality of pressure-sensitive adhesive layers are bonded so that the thickness of the test piece is 1 mm, and then cut into a circular shape having a diameter of 8 mm is used. did.

<Non-deformability evaluation method>
First, a plurality of adhesive tapes were bonded together so that the thickness of the test piece was 1 mm, and then the test piece was obtained by cutting into a circular shape having a diameter of 8 mm.

Using a viscoelasticity tester (manufactured by TA Instruments Japan, trade name: ARES-G2), the test piece is sandwiched between a pair of parallel disks which are measuring units of the tester, The test piece was pressurized in the vertical direction. The initial normal stress (V ₁ ) when the pressure reached 0.5 MPa was measured. Moreover, the distance (distance between a pair of parallel disks) when the pressure was 0.5 MPa was maintained.

Next, the vertical stress (V ₂ ) at the time when 180 seconds had elapsed while maintaining the distance (distance between a pair of parallel disks) from when the pressure became 0.5 MPa was measured.

The initial ratio of the vertical stress to normal stress _{(V 1) (V 2)} [ the vertical stress _(V 2) / initial normal stress _(V 1)] was calculated × 100.

  The pressure-sensitive adhesive tape having the ratio of 50 or more was evaluated as being hard to be deformed and hardly deformed even when an external force was applied. On the other hand, the pressure-sensitive adhesive tape whose ratio was less than 50 was evaluated as being easy to deform when the external force was applied and the external force was relaxed by the pressure-sensitive adhesive tape over time.

<Measurement method of adhesive strength>
A polyethylene terephthalate film (manufactured by Toray Industries, Inc., Lumirror S-10 25 μm) is applied to one adhesive layer surface of the adhesive tape obtained in Example 1 and Comparative Example 1, and bubbles are not left at the interface using a hand roller. Pasted together.

  The patch obtained above was cut into a size of 25 mm × 100 mm, and the surface corresponding to the other adhesive layer was placed on the surface of a clean and smooth glass plate (float plate glass). And they were pasted together by reciprocating a 2 kg roller once in a 50% RH atmosphere.

  Next, after being left in an atmosphere of 23 ° C. and 50% RH for 1 hour, using a Tensilon type peel tester, the patch was placed in a 90 ° direction with respect to the surface of the glass plate at a peel rate of 300 mm / min. The adhesive force was measured by peeling.

Claims (8)

A pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer (B) on at least one surface side of the substrate (A), the storage elastic modulus (E ′ ₂₀ ) measured at a temperature of 20 ° C. and a frequency of 10.0 Hz is 1. 0 × 10 ⁷ Pa or more, the storage elastic modulus (E ′ ₆₀ ) measured at a temperature of 60 ° C. and a frequency of 10.0 Hz is 1.0 × 10 ⁶ Pa or more, and the base material (A) The ratio of the thickness of the pressure-sensitive adhesive layer (B) to the thickness [the thickness of the pressure-sensitive adhesive layer (B) / the thickness of the substrate (A)] is 1/100 to 30/100. tape. The base material (A) has a thickness in the range of 5 μm to 100 μm, and the adhesive layer (B) provided on one side of the base material (A) has a thickness in the range of 0.5 μm to 15 μm. The pressure-sensitive adhesive tape according to claim 1. The pressure-sensitive adhesive tape according to claim 1 or 2, wherein the substrate (A) is an active energy ray cured product having a urethane bond. The storage elastic modulus (E ′ ₂₀ ) measured at a temperature of 20 ° C. and a frequency of 10.0 Hz of the base material (A) is 2.0 × 10 ⁷ Pa or more, and at a temperature of 60 ° C. and a frequency of 10.0 Hz. The pressure-sensitive adhesive tape according to any one of claims 1 to 3, wherein the measured storage elastic modulus (E _'60 ) is 2.0 x 10 ⁶ Pa or more. The pressure-sensitive adhesive layer (B) has an elastic modulus (G ′ ₂₀ ) measured at a temperature of 25 ° C. and a frequency of 1.0 Hz in the range of 1.0 × 10 ^{4 to} 5.0 × 10 ⁵ Pa, and The pressure-sensitive adhesive tape according to any one of claims 1 to 4, wherein a tensile elastic modulus (G _'60 ) measured at a temperature of 60 ° C and a frequency of 1.0 Hz is 1.0 x 10 ⁶ Pa or more. The tensile elastic modulus (E ′ ₂₀ ) measured at a temperature of 20 ° C. and a frequency of 10.0 Hz by applying the active energy ray-curable resin composition to the surface of the release liner and irradiating the active energy ray is 2. A base material (A) having a tensile elastic modulus (E ′ ₆₀ ) of 2.0 × 10 ⁶ Pa or more measured at a temperature of 60 ° C. and a frequency of 10.0 Hz is 0 × 10 ⁷ Pa or more. Step [1] and the ratio of the thickness of the pressure-sensitive adhesive layer (B) to the thickness of the base material (A) on at least one surface side of the base material (A) [of the pressure-sensitive adhesive layer (B) And having a step [2] of providing a pressure-sensitive adhesive layer (B) having a thickness of 1/100 to 30/100 in the range of [thickness / thickness of substrate (A)] the storage modulus measured at a frequency 10.0Hz (E _'20) is 1.0 × ¹⁰ 7 Pa or higher There, the production method of the adhesive tape storage modulus measured at a temperature 60 ° C. and a frequency 10.0Hz (E _'60) is 1.0 × ¹⁰ 6 Pa or more. The base material (A) has a thickness in the range of 5 μm to 100 μm, and the adhesive layer (B) provided on one side of the base material (A) has a thickness in the range of 0.5 μm to 15 μm. A method for producing an adhesive tape according to claim 6. The method for producing a pressure-sensitive adhesive tape according to claim 6, wherein the active energy ray-curable resin composition contains a functional group capable of reacting with an isocyanate group and a polyurethane having an active energy ray-curable functional group.