JP6152319B2 - Adhesive composition, adhesive tape or sheet - Google Patents

Description

  The present invention relates to an adhesive composition and an adhesive tape or sheet.

  Conventionally, a composition containing an epoxy resin is known as a moisture-proof adhesive or pressure-sensitive adhesive (see, for example, Patent Documents 1, 2, and 3). However, a composition containing an epoxy resin must be adhered to an adherend and then subjected to a curing treatment such as heat treatment or ultraviolet treatment (UV treatment) to ensure adhesion, and the adherend is weak against heat and ultraviolet rays. And it was difficult to use for base materials. Moreover, it has been difficult to relax the curing conditions or to secure the adhesive force without performing the curing treatment.

JP 2010-126699 A JP 2012-151109 A JP 2007-112956 A

Accordingly, an object of the present invention is to provide a pressure-sensitive adhesive composition that can secure an adhesive force (adhesive strength) without performing a curing treatment and that forms a pressure-sensitive adhesive layer having excellent moisture resistance.
Another object of the present invention is to provide a pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer that can secure adhesive strength (adhesive strength) without being subjected to a curing treatment after bonding and has excellent moisture resistance.

  As a result of intensive studies by the present inventors, in a pressure-sensitive adhesive composition containing an acrylic monomer mixture or a partially polymerized product thereof and an isobutylene-based polymer, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition is cured. The present inventors have found that an adhesive layer (adhesive strength) can be secured without applying an adhesive and can form a pressure-sensitive adhesive layer excellent in moisture-proof property, and the present invention has been completed.

That is, the present invention is an adhesive composition containing an acrylic monomer mixture or a partial polymer thereof, and an isobutylene polymer,
The pressure-sensitive adhesive composition is characterized in that the moisture permeability measured by the following method of the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition is 100 g / m ² · day or less.
Method of measuring moisture permeability: Using a measurement sample obtained by bonding a pressure-sensitive adhesive layer (thickness 50 μm) formed from the pressure-sensitive adhesive composition to a triacetyl cellulose film (thickness 25 μm), JIS Z 0208 Based on the moisture permeability test method, the moisture permeability is measured under the following conditions.
Measurement temperature: 40 ° C
Relative humidity: 90%
Measurement time: 24 hours

  The adhesive force of the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition is preferably 1.0 N / 25 mm or more.

  The content of the isobutylene polymer is preferably 15 parts by weight or more with respect to 100 parts by weight of the acrylic monomer mixture or a partial polymer thereof.

  The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition preferably has a crosslinked structure.

  The gel fraction of the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition is preferably 20% by weight or more.

  Furthermore, this invention provides the adhesive tape or sheet | seat characterized by having an adhesive layer formed from the said adhesive composition.

Since the pressure-sensitive adhesive composition of the present invention has the above-described configuration, it is possible to secure a bonding force (pressure-sensitive adhesive force) without performing a curing treatment and to form a pressure-sensitive adhesive layer having excellent moisture resistance.
Moreover, since the adhesive tape or sheet | seat of this invention has an adhesive layer formed with the said adhesive composition, it can ensure adhesive force (adhesive force) without performing a hardening process after bonding, and it becomes moisture-proof. Excellent.

[Adhesive composition]
The pressure-sensitive adhesive composition of the present invention contains at least an acrylic monomer mixture or a partial polymer thereof, and an isobutylene polymer. In the pressure-sensitive adhesive composition of the present invention, the isobutylene polymer is dissolved or scattered in the acrylic monomer mixture or a partial polymer thereof. The pressure-sensitive adhesive composition of the present invention is preferably an acrylic pressure-sensitive adhesive composition containing an acrylic monomer mixture or a partial polymer thereof. Moreover, it is preferable that the adhesive layer formed with the adhesive composition of this invention is an acrylic adhesive layer formed with an acrylic adhesive composition.
In the present specification, the “acrylic monomer mixture” is a mixture (or a single product) composed of only monomer components, and a mixture (or a single product) containing at least one acrylic monomer as a monomer component. Say. The “partially polymerized acrylic monomer mixture” refers to a composition in which one or two or more monomer components among the monomer components contained in the acrylic monomer mixture are partially polymerized. The partially polymerized product of the acrylic monomer mixture also includes a mixture of the monomer component and a partially polymerized product obtained by partially polymerizing one or more monomer components among the monomer components contained in the acrylic monomer mixture.
Moreover, in this specification, an adhesive composition is the meaning of the composition used for formation of an adhesive layer, and the meaning of the composition used for formation of an adhesive is included.

  The pressure-sensitive adhesive composition of the present invention is not particularly limited, and may be a composition containing at least an acrylic monomer mixture and an isobutylene polymer, or at least a partial polymer of an acrylic monomer mixture and an isobutylene polymer. It may be a composition. In particular, the pressure-sensitive adhesive composition of the present invention is a composition containing at least an acrylic monomer mixture and an isobutylene polymer from the viewpoint of uniformly dissolving or dispersing an isobutylene polymer in an acrylic monomer mixture or a partial polymer thereof. Preferably there is.

  The pressure-sensitive adhesive composition of the present invention may contain arbitrary components such as a photopolymerization initiator described later in addition to the acrylic monomer mixture or a partial polymer thereof, and an isobutylene polymer. For example, when the pressure-sensitive adhesive composition of the present invention is a composition containing at least an acrylic monomer mixture and an isobutylene polymer, the pressure-sensitive adhesive composition of the present invention can be used in addition to the acrylic monomer mixture and the isobutylene polymer. A polymerization initiator may be included. When the pressure-sensitive adhesive composition of the present invention is a composition containing at least a partial polymer of an acrylic monomer mixture and an isobutylene polymer, photopolymerization is performed in addition to the partial polymer of the acrylic monomer mixture and the isobutylene polymer. An initiator may be included.

  In the pressure-sensitive adhesive composition of the present invention, the ratio of the acrylic monomer mixture or its partial polymer to the total amount (100% by weight) of the pressure-sensitive adhesive composition of the present invention is not particularly limited, but is sufficient for the adherend. From the viewpoint of ensuring good adhesiveness, it is preferably 30% by weight or more, and more preferably 50% by weight or more.

(Acrylic monomer mixture or its partial polymer)
The acrylic monomer mixture is a mixture (single product) of one or more monomer components, and includes at least one acrylic monomer. The acrylic monomer mixture may contain only acrylic monomers, or may contain monomers other than acrylic monomers and acrylic monomers. Although it does not specifically limit as monomers other than such an acryl-type monomer, The below-mentioned polar group containing monomer, a polyfunctional monomer, etc. are mentioned. In addition, the following (meth) acrylic acid alkyl ester, a polar group-containing monomer, and a monomer other than a polyfunctional monomer (sometimes referred to as “other copolymerizable monomers”) may be mentioned. For example, the acrylic monomer mixture may be a mixture containing a polar group-containing monomer and a polyfunctional monomer in addition to the acrylic monomer.

Although it does not specifically limit in the said acrylic monomer mixture, For example, it is preferable that (meth) acrylic-acid alkylester is contained. The said (meth) acrylic-acid alkylester can be used individually or in combination of 2 or more types.
Note that “(meth) acryl” means “acryl” and / or “methacryl” (one or both of “acryl” and “methacryl”), and the same applies to the following.
The “alkyl group” means a linear or branched alkyl group unless otherwise specified.

Although it does not specifically limit as said (meth) acrylic-acid alkylester, For example, the (meth) acrylic-acid alkylester ((meth) acrylic-acid _C1-24 alkylester) which has a C1-C24 alkyl group is mentioned. Is mentioned.
Although it does not specifically limit as said (meth) acrylic acid _C1-24 alkyl ester, For example, (meth) acrylic acid methyl, (meth) acrylic acid ethyl, (meth) acrylic acid propyl, (meth) acrylic acid isopropyl, N-butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, (meta ) Hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, ( (Meth) acrylic acid dodecyl, (meth) acrylic acid tridecyl, (meth) acrylic acid tetra Sil, (meth) acrylate, pentadecyl (meth) acrylate iso-pentadecyl, (meth) acrylate, hexadecyl and the like (meth) acrylic acid iso-hexadecyl.

  Although content of the said (meth) acrylic-acid alkylester in the said acrylic monomer mixture is not specifically limited, For example, 10 weight% or more (for example, 10 to 10 weight% with respect to the said acrylic monomer mixture whole quantity (100 weight%) 100% by weight), preferably 20% by weight or more, and more preferably 30% by weight or more. In addition, when two or more kinds of (meth) acrylic acid alkyl esters are included in the acrylic monomer mixture, the content of the (meth) acrylic acid alkyl ester is the total content of the acrylic monomer mixture. This refers to the total content of (meth) acrylic acid alkyl ester.

As described above, the acrylic monomer mixture may contain a polar group-containing monomer from the viewpoint of obtaining an appropriate cohesive force in the pressure-sensitive adhesive layer and a point of obtaining appropriate adhesiveness in the pressure-sensitive adhesive layer. The polar group-containing monomer is not particularly limited. For example, a carboxyl group-containing monomer such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid (an acid anhydride such as maleic anhydride). Group-containing monomers); (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 3-hydroxypropyl, (meth) acrylic acid 4-hydroxybutyl, (meth) acrylic acid 6-hydroxyhexyl ( Hydroxyl group (hydroxyl) -containing monomers such as hydroxyalkyl methacrylate, vinyl alcohol and allyl alcohol; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl ( (Meth) acrylamide, N- Amide group-containing monomers such as toximethyl (meth) acrylamide and N-hydroxyethyl (meth) acrylamide; aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, etc. Amino group-containing monomers; Epoxy group-containing monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate; Cyano group-containing monomers such as acrylonitrile and methacrylonitrile; N-vinyl-2-pyrrolidone, (meth) acryloyl In addition to morpholine, vinyl-containing monomers such as vinylpyridine, N-vinylpiperidone, vinylpyrimidine, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, and vinyloxazole; Sulfonic acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate, etc .; imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate It is done. The said polar group containing monomer can be used individually or in combination of 2 or more types.

  Among them, the polar group-containing monomer is preferably a carboxyl group-containing monomer or a hydroxyl group-containing monomer, more preferably acrylic acid (AA), 2-hydroxyethyl acrylate (HEA), or acrylic acid, from the viewpoint of adhesion to glass. 4-hydroxybutyl (4HBA).

  The content of the polar group-containing monomer in the acrylic monomer mixture is not particularly limited, but is preferably 0 to 75% by weight, and more preferably, with respect to the total amount (100% by weight) of the acrylic monomer mixture. 0 to 50% by weight. In addition, when two or more types of polar group-containing monomers are included in the acrylic monomer mixture, the content of the polar group-containing monomer is the content of all polar group-containing monomers included in the acrylic monomer mixture. Refers to the total amount.

In addition, as described above, the acrylic monomer mixture can easily adjust the gel fraction of the pressure-sensitive adhesive layer by cross-linking, and can also make the pressure-sensitive adhesive layer difficult to flow by cross-linking. In addition, a polyfunctional monomer may be included. The polyfunctional monomer means a monomer having two or more ethylenically unsaturated groups in one molecule. Although it does not specifically limit as said ethylenically unsaturated group, For example, radical polymerizable functional groups, such as a vinyl group, a propenyl group, an isopropenyl group, a vinyl ether group (vinyloxy group), an allyl ether group (allyloxy group), are mentioned. . The above (meth) acrylic acid alkyl ester, (meth) acrylic acid alkoxyalkyl ester, polar group-containing monomer, and other copolymerizable monomers are monomers having only one ethylenically unsaturated group in one molecule ( Monofunctional monomer).

  The polyfunctional monomer is not particularly limited. For example, hexanediol di (meth) acrylate (1,6-hexanediol di (meth) acrylate), butanediol di (meth) acrylate, (poly) ethylene glycol di ( (Meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri Methylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, epoxy acrylate, poly Ester acrylate, and urethane acrylate. Among these, trimethylolpropane triacrylate is preferable. In addition, the said polyfunctional monomer can be used individually or in combination of 2 or more types.

  Although content of the said polyfunctional monomer is not specifically limited, For example, 0.0001-5 weight% is preferable with respect to the said acrylic monomer mixture whole quantity (100 weight%), More preferably, it is 0.001-3 weight. %, More preferably 0.005 to 1% by weight. In addition, when two or more types of polyfunctional monomers are contained in the acrylic monomer mixture, the content of the polyfunctional monomer is the sum of the contents of all the polyfunctional monomers contained in the acrylic monomer mixture. Say quantity.

As described above, the acrylic monomer mixture contains other copolymerizable monomers (monomers other than the (meth) acrylic acid alkyl ester, the polar group-containing monomer, and the polyfunctional monomer) as a monomer component. May be. Examples of the other copolymerizable monomers include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, and 3-methoxy (meth) acrylate. (Meth) acrylic acid alkoxyalkyl esters such as propyl, (meth) acrylic acid 3-ethoxypropyl, (meth) acrylic acid 4-methoxybutyl, (meth) acrylic acid 4-ethoxybutyl; (meth) acrylic acid glycidyl, ( Epoxy group-containing monomer such as methyl glycidyl acrylate; sulfonic acid group-containing monomer such as sodium vinyl sulfonate; phosphoric acid group-containing monomer; cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic acid Cycloaliphatic carbonization such as isobornyl (Meth) acrylic acid ester having an elementary group; (meth) acrylic acid ester having an aromatic hydrocarbon group such as phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate; vinyl acetate Vinyl esters such as vinyl propionate; aromatic vinyl compounds such as styrene and vinyl toluene; olefins or dienes such as ethylene, propylene, butadiene, isoprene and isobutylene; vinyl ethers such as vinyl alkyl ether; vinyl chloride and the like Can be mentioned. Other copolymerizable monomers can be used alone or in combination of two or more.

  The acrylic monomer mixture is not particularly limited, and can be prepared, for example, by mixing (preferably uniformly mixing) the monomer components.

  The partially polymerized product of the acrylic monomer mixture is obtained by polymerizing the acrylic monomer mixture. Although it does not specifically limit as a polymerization method, For example, superposition | polymerization by active energy ray irradiation is mentioned preferably. In addition, it is preferable to superpose | polymerize by avoiding a contact with oxygen from the point which suppresses the superposition | polymerization inhibition by oxygen. For example, it is preferable to perform polymerization in a nitrogen atmosphere, or to perform polymerization while blocking oxygen with a release liner.

  Examples of the active energy rays irradiated in the active energy ray polymerization (photopolymerization) include ionizing radiation such as α rays, β rays, γ rays, neutron rays, electron rays, and ultraviolet rays, and particularly ultraviolet rays. Is preferred. The irradiation energy, irradiation time, irradiation method, and the like of the active energy ray are not particularly limited as long as the photopolymerization initiator can be activated to cause a monomer polymerization reaction.

  In the active energy ray polymerization (photopolymerization), a polymerization initiator such as a photopolymerization initiator (photoinitiator) may be used. The said polymerization initiator can be used individually or in combination of 2 or more types.

  The photopolymerization initiator is not particularly limited. For example, benzoin ether photopolymerization initiator, acetophenone photopolymerization initiator, α-ketol photopolymerization initiator, aromatic sulfonyl chloride photopolymerization initiator, photo Examples thereof include active oxime photopolymerization initiators, benzoin photopolymerization initiators, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, and thioxanthone photopolymerization initiators.

  Examples of the benzoin ether photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, Anisole methyl ether etc. are mentioned. Examples of the acetophenone photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, and 4- (t-butyl). ) Dichloroacetophenone and the like. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone and 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropan-1-one. It is done. Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime. Examples of the benzoin photopolymerization initiator include benzoin. Examples of the benzyl photopolymerization initiator include benzyl. Examples of the benzophenone photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexyl phenyl ketone, and the like. Examples of the ketal photopolymerization initiator include benzyl dimethyl ketal. Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, and the like.

  Although the usage-amount of the said photoinitiator is not specifically limited, 0.005-1 weight part is preferable with respect to 100 weight part of monomer component whole quantity, More preferably, it is 0.01-0.5 weight part.

Although the polymerization rate of the partial polymerization product of the acrylic monomer mixture is not particularly limited, it is preferably, for example, 20% by weight or less, and more preferably 15% by weight or less.

The polymerization rate of the partially polymerized product of the acrylic monomer mixture is determined as follows.
A part of the partially polymerized product is sampled and used as a sample. The sample is precisely weighed to determine its weight, and is defined as “weight of partially polymerized product before drying”. Next, the sample is dried at 130 ° C. for 2 hours, and the dried sample is precisely weighed to obtain its weight, which is defined as “weight of partially polymerized product after drying”. Then, from the “weight of the partial polymer before drying” and the “weight of the partial polymer after drying”, the weight of the sample decreased by drying at 130 ° C. for 2 hours is obtained, and the “weight reduction amount” (volatile content, Unreacted monomer weight).
From the obtained “weight of partial polymer before drying” and “weight loss”, the polymerization rate (% by weight) of the partial polymer is obtained from the following formula.
Polymerization rate of partial polymer of monomer component (% by weight) = [1− (weight reduction) / (weight of partial polymer before drying)] × 100

(Isobutylene polymer)
The pressure-sensitive adhesive composition of the present invention contains an isobutylene polymer together with the acrylic monomer mixture or a partial polymer thereof. For this reason, the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition of the present invention has a low moisture permeability. This is because the isobutylene polymer itself is difficult to permeate water vapor, and the isobutylene polymer in the pressure-sensitive adhesive layer blocks the water vapor path when water vapor tries to pass through the pressure-sensitive adhesive layer. It is presumed that the passage of water vapor through the pressure-sensitive adhesive layer is hindered by increasing or decreasing the length.

  The isobutylene polymer (polyisobutylene) is a polymer containing at least a monomer constituent unit derived from isobutylene (isobutene). That is, the isobutylene-based polymer is a polymer obtained by polymerizing a monomer component containing isobutylene. The isobutylene-based polymer is also a polymer having at least a polyisobutylene skeleton in the main chain or side chain. The above isobutylene polymers can be used alone or in combination of two or more.

The isobutylene-based polymer may be a homopolymer of isobutylene or a copolymer of isobutylene and another monomer (isobutylene copolymer). In the isobutylene copolymer, the other monomer copolymerized with isobutylene is not particularly limited, and examples thereof include a monomer having an ethylenic double bond. Examples of the monomer having an ethylenic double bond include α-olefins having 2 to 20 carbon atoms (for example, ethylene and propylene), aromatic vinyl compounds (for example, styrene compounds such as styrene, methylstyrene, and styrene). Product ), 1,3-butadiene compounds (for example, 1,3-butadiene, isoprene, etc.) and the like. Among these, a styrene compound is preferable from the viewpoint of easily obtaining cohesive force. The monomer component which comprises the said isobutylene type polymer can be used individually or in combination of 2 or more types.

  The isobutylene-based polymer is not particularly limited. For example, butyl rubber (polymer of isobutylene and isoprene), a random copolymer of isobutylene and normal butylene, a polymer block of an isobutylene polymer block and another monomer (for example, And block copolymers of styrene compounds with styrene polymer blocks, isoprene polymer blocks, etc.). Among them, a styrene polymer block having a styrene polymer block as a hard segment and an isobutylene polymer block as a soft segment (SIB block copolymer), a styrene-isobutylene-styrene block copolymer (SIBS block copolymer). ) Is preferred.

  Commercially available products can be used as the SIBS block copolymer, for example, trade name “SIBSTAR-062M” (manufactured by Kaneka Corporation), trade name “SIBSTAR-062T” (manufactured by Kaneka Corporation), Product name “SIBSTAR-072T” (manufactured by Kaneka Corporation) and the like.

  The proportion of isobutylene in the monomer constituting the isobutylene polymer is not particularly limited, but from the viewpoint of moisture resistance of the pressure-sensitive adhesive layer, the total amount of monomer components constituting the isobutylene polymer (100% by weight), 30 weight% or more (for example, 30-100 weight%) is preferable, More preferably, it is 50 weight% or more (for example, 50-100 weight%).

  Although content of the said isobutylene type polymer in the adhesive composition of this invention is not specifically limited, 15 weight part or more (for example, 15-100 weight) with respect to 100 weight part of the said acrylic monomer mixture or its partial polymer. Part) is preferred. When the content of the isobutylene polymer is 15 parts by weight or more, in the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition, it becomes easier to obtain better moisture resistance. Further, when the content of the isobutylene polymer is 100 parts by weight or less, the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition has sufficient cohesion and excellent cohesive strength even at high temperatures. Is easier to obtain. Moreover, the flow of the pressure-sensitive adhesive layer can be effectively suppressed, which is preferable.

(Tackifying resin)
The pressure-sensitive adhesive composition of the present invention may further contain a tackifier resin from the viewpoint of further improving the adhesiveness in the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition. The tackifying resin is not particularly limited. For example, alicyclic saturated hydrocarbon resin, petroleum resin, terpene resin, coumarone / indene resin, styrene resin, rosin resin, alkylphenol resin, xylene resin. Etc. The tackifying resin is a hydrogenated type tackifying resin (for example, alicyclic saturated hydrocarbon resin, rosin resin, petroleum resin, terpene resin, coumarone / indene resin, styrene resin, alkylphenol resin, Derivatives (hydrogenated rosin resin, hydrogenated petroleum resin, hydrogenated terpene resin, etc.) hydrogenated to a tackifying resin such as xylene resin may be used alone or in combination. Two or more types can be used in combination.

  Although content of the said tackifying resin in the adhesive composition of this invention is not specifically limited, 1-50 weight part is preferable with respect to 100 weight part of the said acrylic monomer mixture or its partial polymer, More preferably The amount is 1.5 to 40 parts by weight, more preferably 2 to 30 parts by weight. When the content of the tackifying resin is 1 part by weight or more, excellent adhesiveness is easily obtained in the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition, which is preferable. Moreover, when the content of the tackifying resin is 50 parts by weight or less, in the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition, the cohesive force is hardly reduced, which is preferable.

  The pressure-sensitive adhesive composition of the present invention may further contain an acrylic oligomer as long as the effects of the present invention are not impaired. Since the acrylic oligomer functions as a tackifier component, adhesion can be improved. The said acrylic oligomer can be used individually or in combination of 2 or more types.

  The pressure-sensitive adhesive composition of the present invention may further contain a silane coupling agent as long as the effects of the present invention are not impaired. When the silane coupling agent is contained in the pressure-sensitive adhesive composition of the present invention, the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition has adhesiveness (particularly, adhesion in a high-temperature and high-humidity environment, high-temperature and high-humidity). Adhesion to glass in the environment) is further improved. The said silane coupling agent can be used individually or in combination of 2 or more types.

  The silane coupling agent is not particularly limited, but γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-aminopropyltrimethoxysilane. Etc. are preferred.

  Although content of the said silane coupling agent in the adhesive composition of this invention is not specifically limited, 0.01-1 weight part is preferable with respect to 100 weight part of the said acrylic monomer mixture or its partial polymer, More preferably, it is 0.03-0.5 weight part.

  In the pressure-sensitive adhesive composition of the present invention, the gel fraction of the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition is adjusted to an appropriate range, and the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition is made difficult to flow. From the viewpoint of easy handling, a crosslinking agent may be further contained. The crosslinking agent is not particularly limited. For example, an isocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent, a peroxide crosslinking agent, a urea crosslinking agent, a metal alkoxide crosslinking agent, a metal chelate crosslinking agent. Agents, metal salt crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, amine crosslinking agents and the like. Of these, isocyanate crosslinking agents and epoxy crosslinking agents are preferred. The said crosslinking agent can be used individually or in combination of 2 or more types.

  Examples of the isocyanate-based crosslinking agent (polyfunctional isocyanate compound) include lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; cyclopentylene diisocyanate , Cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, and the like; 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate , Aromatic polyisocyanates such as xylylene diisocyanate, etc., trimethylolpropane / tolylene diisocyanate adduct [Japan Polyurethane Industry Co., Ltd. under the trade name "Coronate L"], trimethylolpropane / hexamethylene diisocyanate adduct [Nippon Polyurethane Industry Co., Ltd. under the trade name "Coronate HL"], and also such.

  Examples of the epoxy crosslinking agent (polyfunctional epoxy compound) include N, N, N ′, N′-tetraglycidyl-m-xylenediamine, diglycidylaniline, and 1,3-bis (N, N-diglycidyl). Aminomethyl) cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether Glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethy Roll propane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris (2-hydroxyethyl) isocyanurate, resorcin diglycidyl ether, bisphenol-S-diglycidyl ether, intramolecular And an epoxy resin having two or more epoxy groups. Furthermore, commercial items, such as a brand name "Tetrad C" (made by Mitsubishi Gas Chemical Co., Ltd.), are also mentioned.

  The content of the cross-linking agent in the pressure-sensitive adhesive composition of the present invention is not particularly limited, but the acrylic monomer is used from the viewpoint of controlling the gel fraction of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition to an appropriate range. 0.001-30 weight part is preferable with respect to 100 weight part of a mixture or its partial polymer, More preferably, it is 0.005-25 weight part, More preferably, it is 0.01-20 weight part.

  The pressure-sensitive adhesive composition of the present invention may contain an additive as long as the effects of the present invention are not impaired. Examples of the additive include a crosslinking accelerator, an anti-aging agent, a filler, a colorant (such as a pigment and a dye), an ultraviolet absorber, an antioxidant, a chain transfer agent, a plasticizer, a softening agent, a surfactant, Examples thereof include an antistatic agent. The said additive can be used individually or in combination of 2 or more types.

  A method for preparing the pressure-sensitive adhesive composition of the present invention is not particularly limited. For example, the acrylic monomer mixture or a partial polymer thereof, an isobutylene polymer, and any component added as necessary (for example, the above light A polymerization initiator, the tackifier resin, the acrylic oligomer, the silane coupling agent, the cross-linking agent, the additive, and the like).

  For example, when the pressure-sensitive adhesive composition of the present invention is a composition containing an acrylic monomer mixture and an isobutylene polymer and further containing a photopolymerization initiator, such a composition contains an acrylic monomer mixture, an isobutylene polymer and It can be prepared by mixing a photopolymerization initiator.

  Further, when the pressure-sensitive adhesive composition of the present invention is a composition containing a partial polymer of an acrylic monomer mixture and an isobutylene polymer, and further containing a photopolymerization initiator, such a composition is composed of an acrylic monomer mixture. It can be prepared by mixing a partial polymer, an isobutylene polymer and a photopolymerization initiator. As described above, the partial polymerization product of the acrylic monomer mixture is formed by partial polymerization of the acrylic monomer mixture, and includes, for example, the partial polymerization product of the acrylic monomer mixture and the isobutylene polymer, and further starts photopolymerization. The composition containing an agent may be prepared by first partially polymerizing a composition containing at least an acrylic monomer mixture and a photopolymerization initiator and then adding a photopolymerization initiator. Further, a composition containing at least a partial polymer of an acrylic monomer mixture and an isobutylene polymer is prepared by first partially polymerizing the acrylic monomer mixture and then adding an acrylic monomer or a polyfunctional monomer. May be.

The viscosity of the pressure-sensitive adhesive composition of the present invention is not particularly limited, but is preferably 0.1 to 100 Pa · s from the viewpoint of easier handling of the pressure-sensitive adhesive composition and further improving the coating property. Preferably it is 0.5-50 Pa.s.
In the present specification, the viscosity means a rotor: No. using a BH viscometer as a viscometer. The viscosity measured under the conditions of 5 rotors, rotation speed: 10 rpm, measurement temperature: 30 ° C.

  In addition, since the said acrylic monomer mixture has a low viscosity, there exists a tendency for the composition which contains an acrylic monomer mixture as a main component to become difficult to apply to a base material, a support body, etc. However, since the pressure-sensitive adhesive composition of the present invention contains an isobutylene polymer in addition to the acrylic monomer mixture or a partial polymer thereof, the viscosity can be easily maintained in the above range.

In the pressure-sensitive adhesive composition of the present invention, since the isobutylene polymer is easily dissolved in the acrylic monomer mixture or a partial polymer thereof, the viscosity can be maintained in the above range without adding a solvent. That is, the pressure-sensitive adhesive composition of the present invention may not contain a solvent. When the pressure-sensitive adhesive layer of the present invention does not contain a solvent, heating and drying after coating is not necessary, and the formation of the pressure-sensitive adhesive layer is further facilitated. It is also excellent in terms of environment and safety.
The viscosity of the pressure-sensitive adhesive composition of the present invention may be adjusted by, for example, blending various polymer components such as acrylic rubber and thickening additives.

  In general, an isobutylene-based polymer does not have a crosslinking point, and thus cannot form a crosslinked structure, and tends to flow at a high temperature, and may be inferior in durability at a high temperature. In addition, isobutylene polymers are often inferior in tack and tackiness. However, since the pressure-sensitive adhesive composition of the present invention contains an acrylic monomer mixture or a partial polymer thereof and an isobutylene-based polymer, it is possible to form a pressure-sensitive adhesive layer excellent in moisture resistance and adhesiveness. Moreover, when an adhesive layer has a crosslinked structure, durability at high temperature can be improved especially.

In the pressure-sensitive adhesive composition of the present invention, the moisture permeability measured by the following method of the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition is 100 g / m ² · day or less, preferably 80 g / m ² · day or less. More preferably, it is 60 g / m ² · day or less.
Method of measuring moisture permeability: Using a measurement sample obtained by bonding a pressure-sensitive adhesive layer (thickness 50 μm) formed from a pressure-sensitive adhesive composition to a triacetyl cellulose film (thickness 25 μm), the permeability of JIS Z 0208 In accordance with the humidity test method, the moisture permeability is measured under the following conditions.
Measurement temperature: 40 ° C
Relative humidity: 90%
Measurement time: 24 hours In this specification, “moisture permeability measured by the above method of the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition” in the pressure-sensitive adhesive composition is simply referred to as “moisture permeability of the present invention”. Sometimes called.

The pressure-sensitive adhesive composition of the present invention has excellent moisture resistance since the moisture permeability of the present invention is 100 g / m ² · day or less.

[Adhesive tape or sheet]
The pressure-sensitive adhesive tape or sheet of the present invention has a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention. That is, the pressure-sensitive adhesive tape or sheet of the present invention is preferably an acrylic pressure-sensitive adhesive tape or sheet having an acrylic pressure-sensitive adhesive layer formed from an acrylic pressure-sensitive adhesive composition. In this specification, the pressure-sensitive adhesive tape or sheet of the present invention may be simply referred to as “the pressure-sensitive adhesive tape of the present invention”. Moreover, the adhesive layer formed from the adhesive composition of this invention may be called "the adhesive layer of this invention."

  The pressure-sensitive adhesive tape of the present invention may be a single-sided pressure-sensitive adhesive tape whose only one surface is the pressure-sensitive adhesive layer surface (pressure-sensitive adhesive surface), or may be a double-sided pressure-sensitive adhesive tape whose both surfaces are the pressure-sensitive adhesive layer surface. The pressure-sensitive adhesive tape of the present invention is not particularly limited, but is preferably a double-sided pressure-sensitive adhesive tape from the viewpoint of being used for bonding adherends to each other.

The pressure-sensitive adhesive tape of the present invention may be a pressure-sensitive adhesive tape having no base material (base material layer), a so-called “base-less type” pressure-sensitive adhesive tape (sometimes referred to as “base-material-less pressure-sensitive adhesive tape”). Or an adhesive tape having a substrate (sometimes referred to as “adhesive tape with substrate”). Examples of the substrate-less pressure-sensitive adhesive tape include a double-sided pressure-sensitive adhesive tape comprising only the pressure-sensitive adhesive layer of the present invention (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention), and the pressure-sensitive adhesive layer of the present invention and the present invention. And a double-sided pressure-sensitive adhesive tape comprising a pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer (sometimes referred to as “other pressure-sensitive adhesive layer”). As the pressure-sensitive adhesive tape having the above-mentioned base material, for example, a single-sided pressure-sensitive adhesive tape having the pressure-sensitive adhesive layer of the present invention on one side of the base material, a double-sided pressure-sensitive adhesive tape having the pressure-sensitive adhesive layer of the present invention on both sides of the base material, Examples thereof include a double-sided pressure-sensitive adhesive tape having the pressure-sensitive adhesive layer of the present invention on one side of the substrate and the other pressure-sensitive adhesive layer on the other side.
The above-mentioned “base material (base material layer)” is affixed to the adherend together with the adhesive layer when the adhesive tape of the present invention is used (attached) to the adherend (such as an optical member). This does not include a release liner (separator) that is peeled off when the adhesive tape is used (attached).

  Among them, the pressure-sensitive adhesive tape of the present invention is preferably a substrate-less pressure-sensitive adhesive tape from the viewpoint that, when used, it can cope with various modes, and can limit the mode of use and increase the number of options for use. Is a double-sided pressure-sensitive adhesive tape (substrate-less double-sided pressure-sensitive adhesive tape) having only a base material and comprising only the pressure-sensitive adhesive layer of the present invention.

(Adhesive layer of the present invention)
The pressure-sensitive adhesive layer of the present invention is formed from the pressure-sensitive adhesive composition of the present invention. The method for forming the pressure-sensitive adhesive layer of the present invention is not particularly limited. For example, the pressure-sensitive adhesive composition of the present invention is applied (applied) onto a suitable support such as a substrate or a release liner, and active energy rays are applied. Irradiation. In addition, heat-drying may be performed after coating as needed.

  Note that a known coating method may be used for the above coating (coating). For example, a conventional coater, specifically, a gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, spray coater, comma coater, direct coater or the like may be used.

  When the active energy ray is irradiated after application of the pressure-sensitive adhesive composition of the present invention, examples of the active energy ray to be irradiated include ionization of α ray, β ray, γ ray, neutron ray, electron beam and the like. Radiation, ultraviolet rays and the like, and ultraviolet rays are particularly preferable. Moreover, the irradiation energy, irradiation time, irradiation method, etc. of an active energy ray are not specifically limited.

  The pressure-sensitive adhesive layer of the present invention contains at least a base polymer derived from an acrylic monomer mixture or a partial polymer thereof (that is, an acrylic polymer as a base polymer) and an isobutylene polymer. The pressure-sensitive adhesive layer of the present invention is not particularly limited. For example, the entire pressure-sensitive adhesive layer may have a uniform composition, or the pressure-sensitive adhesive layer contains a large amount of isobutylene-based polymer (for example, isobutylene-based polymer). Part containing 60 to 80% by weight or more) (sometimes referred to as “isobutylene polymer part”), and part containing a large amount of acrylic polymer as a base polymer derived from the above acrylic monomer mixture or its partial polymer (For example, a portion containing 60 to 80% by weight or more of the base polymer) (sometimes referred to as “acrylic polymer portion”) may be included.

  Usually, the pressure-sensitive adhesive layer has a uniform structure as a whole and often has uniform characteristics. The pressure-sensitive adhesive layer of the present invention (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) is a portion having a large amount of isobutylene polymer (for example, the above-mentioned isobutylene polymer portion) and a portion having a large amount of acrylic polymer as a base polymer It is preferable to have a structure in which (for example, the above-mentioned acrylic polymer portion) is scattered in a very small distribution. That is, it is preferable that the pressure-sensitive adhesive layer of the present invention has a separated structure (phase separated structure) of an acrylic polymer and an isobutylene polymer as a phase structure. When the pressure-sensitive adhesive layer of the present invention has such a structure, each of the properties of moisture resistance, cohesive strength (particularly, cohesive strength at high temperature), and adhesive properties is higher than that of a uniform case. It is obtained with. That is, the moisture-proof property, adhesiveness, and cohesive force at high temperature can be realized at a high level as the entire pressure-sensitive adhesive layer. This is because the isobutylene polymer has low moisture permeability and particularly excellent moisture resistance, while the acrylic polymer has high moisture permeability and inferior moisture resistance, but has excellent cohesive strength, particularly cohesive strength at high temperatures, and adhesiveness. It is because it is excellent in. Further, when the pressure-sensitive adhesive composition of the present invention contains a tackifier resin and the pressure-sensitive adhesive layer of the present invention has such a structure, the tackifier resin is a portion having a large amount of isobutylene polymer and a portion having a large amount of acrylic polymer. It is distributed moderately in both. For this reason, when the adhesive layer of this invention contains tackifying resin, adhesiveness improves further, without reducing moisture resistance as the whole adhesive layer. Examples of the tackifier resin that easily obtains such characteristics include saturated hydrocarbon resins.

  The proportion of the portion having a large amount of the isobutylene-based polymer (for example, the isobutylene-based polymer portion) and the portion having the large amount of the acrylic polymer (for example, the acrylic polymer portion) is, for example, the polymerization rate of the partial polymer of the acrylic monomer mixture, It can be adjusted by the content of the acrylic monomer mixture or its partial polymer in the pressure-sensitive adhesive composition, the content of the isobutylene polymer in the pressure-sensitive adhesive composition, the illuminance of active energy rays, and the like.

  Although the thickness of the adhesive layer of this invention is not specifically limited, 5-200 micrometers is preferable from the point which acquires the outstanding adhesiveness, and the point which suppresses the flow of an adhesive layer, More preferably, it is 10-100 micrometers.

  Moreover, it is preferable that the adhesive layer of this invention has a crosslinked structure. That is, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention preferably has a crosslinked structure. When it has a crosslinked structure, the thermal stability of the pressure-sensitive adhesive layer is further improved. For example, even under a high temperature environment (for example, a temperature environment of 80 to 100 ° C.), problems such as the pressure-sensitive adhesive layer flowing and peeling off hardly occur. The crosslinked structure can be obtained, for example, by using a polyfunctional monomer or a crosslinking agent.

  The gel fraction of the pressure-sensitive adhesive layer of the present invention (the pressure-sensitive adhesive formed from the pressure-sensitive adhesive composition of the present invention) is not particularly limited, but the point of thermal stability is that the flow of the pressure-sensitive adhesive layer at high temperatures is suppressed. More preferably, it is 20% by weight or more (for example, 20 to 99.9% by weight), more preferably 30% by weight or more (for example, 30 to 99.9% by weight), and even more preferably 50% by weight or more (for example, 50 to 99.99%). 9% by weight), more preferably 60% by weight or more (for example, 60 to 99.9% by weight).

The said gel fraction (solvent insoluble content) is calculated | required as follows.
(Measurement method of gel fraction)
Adhesive layer: About 0.1 g was sampled, wrapped in a porous tetrafluoroethylene sheet (trade name “NTF1122”, manufactured by Nitto Denko Corporation) with an average pore diameter of 0.2 μm, and then tied with silk thread. The weight is measured, and this weight is defined as the weight before immersion. The weight before immersion is the total weight of the acrylic pressure-sensitive adhesive layer (collected above), the tetrafluoroethylene sheet, and the kite string. Further, the total weight of the tetrafluoroethylene sheet and the kite string is also measured, and this weight is defined as the wrapping weight.
Next, a pressure-sensitive adhesive layer wrapped with a tetrafluoroethylene sheet and bound with a kite string (referred to as “sample”) is placed in a 50 ml container filled with ethyl acetate and allowed to stand at 23 ° C. for 7 days. Then, the sample (after ethyl acetate treatment) is taken out from the container, transferred to an aluminum cup, dried in a dryer at 130 ° C. for 2 hours to remove ethyl acetate, the weight is measured, and the weight is immersed. After weight.
Then, the gel fraction is calculated from the following formula.
Gel fraction (% by weight) = (ab) / (c−b) × 100
(In the above formula, a is the weight after immersion, b is the weight of the bag, and c is the weight before immersion.)

In addition, the pressure-sensitive adhesive layer of the present invention has a moisture permeability of 100 g / m ² · day or less (preferably 85 g / m ² · day or less, more preferably, from the viewpoint of obtaining excellent moisture resistance. Is 70 g / m ² · day or less).
Measurement method of moisture permeability: Using a measurement sample obtained by bonding an adhesive layer (thickness 50 μm) to a triacetyl cellulose film (thickness 25 μm), the moisture permeability test method (cup method) of JIS Z 0208 In conformity, the moisture permeability is measured under the following conditions. More specifically, it can be measured by the method described in “(Measurement method of moisture permeability)” in (Evaluation) described later.
Measurement temperature: 40 ° C
Relative humidity: 90%
Measurement time: 24 hours

Furthermore, the adhesive strength of the pressure-sensitive adhesive layer of the present invention (measurement temperature: 23 ° C., relative humidity: 50% RH, tensile speed: 300 mm / min, peeling angle: 180 ° peeling condition, glass plate) is not particularly limited. However, it is preferably 1.0 N / 25 mm or more, more preferably 3.0 N / 25 mm or more, and still more preferably 5.0 N / 25 mm or more. When the adhesive force is in the above range, the acrylic pressure-sensitive adhesive layer has excellent adhesiveness without performing a curing treatment.
More specifically, the adhesive strength of the acrylic pressure-sensitive adhesive layer can be measured by the method described in “(Measurement of adhesive strength)” in (Evaluation) described later.

(Base material)
As described above, the pressure-sensitive adhesive tape of the present invention may be a pressure-sensitive adhesive tape with a substrate having at least the pressure-sensitive adhesive layer and the substrate layer of the present invention. Although it does not specifically limit as said base material, For example, a plastic base material (polymer base material) is mentioned preferably. The base material may be a single layer base material (single layer base material) or may have a laminated structure of two or more layers (laminated base material).

  Although it does not specifically limit as a material which comprises the said plastic base material, For example, Polyesters, such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate; Polyolefins, such as polyethylene, a polypropylene, an ethylene propylene copolymer Polyvinyl alcohol, polyvinylidene chloride, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyamide, polyimide, celluloses such as triacetyl cellulose and diacetyl cellulose, fluororesin, polyether, polyether amide ; Polyetheretherketone; Polyphenylene sulfide; Polystyrene resin such as polystyrene; Polycarbonate; Polyethersulfone; Polymethylmeta Acrylic resins such relations and the like. In addition, the said material can be used individually or in combination of 2 or more types.

  Among them, as the material constituting the plastic base material, polyester, celluloses, acrylic resins, and the like are preferable, and more preferable because of the good balance of strength, handleability (handling property), cost, dimensional stability, and anchoring force. Polyethylene terephthalate (PET), triacetyl cellulose (TAC), and polymethyl methacrylate (PMMA). That is, the base material is preferably a polyethylene terephthalate base material, a triacetyl cellulose base material, or a polymethyl methacrylate base material.

  The base material may be subjected to a surface treatment as necessary. Examples of the surface treatment include treatment by chemical or physical methods such as chromic acid treatment, ozone exposure, flame exposure, high piezoelectric impact exposure, and ionizing radiation treatment. Moreover, the primer process for improving adhesiveness with an adhesive layer may be performed.

  In addition, the base material may be subjected to a hard coat treatment from the viewpoint of improving the scratch resistance (abrasion resistance) of the surface. When the surface of the base material is subjected to a hard coat treatment, the base material surface protecting property (property that the base material surface is hardly damaged) is improved. Moreover, the base material may be subjected to antistatic treatment from the viewpoint of suppressing the generation of static electricity.

  The base material may be, for example, a base material that has been subjected to a primer treatment on one surface in order to improve adhesion to the pressure-sensitive adhesive layer and a hard coat treatment on the other surface.

(Other layers)
The pressure-sensitive adhesive tape of the present invention may have other layers (for example, an intermediate layer, an undercoat layer, etc.) as long as the effects of the present invention are not impaired in addition to the pressure-sensitive adhesive layer and the substrate of the present invention.

(Release liner)
As described above, in the pressure-sensitive adhesive tape of the present invention, the pressure-sensitive adhesive surface may be protected by the release liner. Although it does not specifically limit as said release liner, A well-known thru | or usual release liner is mentioned preferably. Specifically, polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT); polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), ethylene-propylene Olefin resin containing α-olefin as monomer component such as copolymer, ethylene-vinyl acetate copolymer (EVA); polyvinyl chloride (PVC); vinyl acetate resin; polycarbonate (PC); polyphenylene sulfide (PPS) Amide resins such as polyamide (nylon) and wholly aromatic polyamide (aramid); polyimide resins; polyether ether ketone (PEEK); olefin resins such as polyethylene (PE) and polypropylene (PP); Plastic films composed of fluororesins such as fluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chlorofluoroethylene-vinylidene fluoride copolymer, etc. Preferably mentioned.

  Further, the release liner includes a release liner having a release layer (release treatment layer) on at least one surface of a release liner substrate, a low-adhesive release liner made of a fluorine-based polymer, and a low-adhesiveness made of a nonpolar polymer. And a release liner. In addition, a release liner base material having no release layer (that is, the release liner base material itself) is also included. The fluorine-based polymer is not particularly limited. For example, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chlorofluoroethylene-fluoride And vinylidene copolymer. The nonpolar polymer is not particularly limited, and examples thereof include olefin resins such as polyethylene (PE) and polypropylene (PP). Among these, it is preferable to use a release liner having a release layer on at least one surface of the release liner substrate, or a release liner substrate having no release layer (that is, the release liner substrate itself).

  Although it does not specifically limit as said release liner base material, A plastic film etc. are mentioned. Examples of such plastic films include polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); polyethylene (PE), polypropylene (PP), and polymethylpentene (PMP). ), Ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA) and other olefin-based resins containing α-olefin as a monomer component; polyvinyl chloride (PVC); vinyl acetate-based resin; polycarbonate (PC); Examples include polyphenylene sulfide (PPS); amide resins such as polyamide (nylon) and wholly aromatic polyamide (aramid); polyimide resins; and plastic films composed of polyether ether ketone (PEEK). It is. Among these, from the viewpoints of processability, availability, workability, dust resistance, cost, and the like, a plastic film formed from a polyester resin is preferable, and a PET film is more preferable.

  The release treatment agent constituting the release layer is not particularly limited, and examples thereof include release treatment agents such as silicone release treatment agents, fluorine release treatment agents, long-chain alkyl release treatment agents, and molybdenum sulfide. Among these, a silicone-based release treatment agent is preferable from the viewpoint of release control and stability over time. In addition, an exfoliation processing agent can be used individually or in combination of 2 or more types.

  The release liner can be produced by a publicly known method. Further, the thickness of the release liner is not particularly limited.

(Production method)
Although the manufacturing method of the adhesive tape of this invention is not specifically limited, A well-known formation method can be utilized. For example, when the pressure-sensitive adhesive tape of the present invention is a pressure-sensitive adhesive tape with a base material, it can be produced by forming the pressure-sensitive adhesive layer of the present invention on at least one surface side of the base material from the pressure-sensitive adhesive composition of the present invention. . When the pressure-sensitive adhesive tape of the present invention is a substrateless pressure-sensitive adhesive tape comprising the pressure-sensitive adhesive layer of the present invention, the pressure-sensitive adhesive composition of the present invention is formed on the release liner by the pressure-sensitive adhesive composition of the present invention. Can be produced.

(Physical properties)
The pressure-sensitive adhesive tape of the present invention is not particularly limited, but the moisture permeability required by the following measurement method is preferably 100 g / m ² · day or less, more preferably 80 g / m ² , from the viewpoint of obtaining excellent moisture resistance. m ² · day or less, more preferably 60 g / m ² · day or less.
Measurement method of moisture permeability: Using a measurement sample obtained by bonding an adhesive tape to a triacetyl cellulose film (thickness 25 μm), in accordance with the moisture permeability test method of JIS Z 0208, Measure humidity.
Measurement temperature: 40 ° C
Relative humidity: 90%
Measurement time: 24 hours

The adhesive strength of the pressure-sensitive adhesive tape of the present invention (measurement temperature: 23 ° C., relative humidity: 50% RH, tensile speed: 300 mm / min, peeling angle: 180 ° peeling condition, glass plate) is not particularly limited. It is preferably 0.0 N / 25 mm or more, more preferably 3.0 N / 25 mm or more, and still more preferably 5.0 N / 25 mm or more. When the adhesive force is within the above range, the pressure-sensitive adhesive tape of the present invention has excellent adhesiveness without being subjected to a curing treatment.
More specifically, the adhesive strength of the pressure-sensitive adhesive tape of the present invention can be measured by the method described in “(Measurement of adhesive strength)” in (Evaluation) described later.

  Although the thickness of the adhesive tape of this invention is not specifically limited, 5-200 micrometers is preferable, More preferably, it is 10-100 micrometers.

  Since the pressure-sensitive adhesive tape of the present invention has the pressure-sensitive adhesive layer of the present invention, the adhesive tape exhibits sufficient adhesion to the adherend and is excellent in moisture resistance without being subjected to a curing treatment after bonding. Further, the adherend can be protected from moisture.

  The pressure-sensitive adhesive tape of the present invention exhibits sufficient adhesion to an adherend without being subjected to a curing treatment, and is excellent in moisture resistance, so that it can be used for protection of an adherend that is weak in humidity. Can do. For example, the pressure-sensitive adhesive tape of the present invention can be used as a protective film.

  Since the pressure-sensitive adhesive tape of the present invention has the above-described characteristics, it can be used for, for example, an electric or electronic device (for example, an electric or electronic device that is weak against heat, humidity, and ultraviolet rays). In particular, it can be preferably used for surface protection when manufacturing electrical or electronic equipment, surface protection when using electrical or electronic equipment, and the like. Moreover, it can use preferably for optical uses (for example, surface protection use at the time of manufacture of an optical product or an optical member, surface protection use at the time of use of an optical product or an optical member).

  Although it does not specifically limit as said electric equipment, For example, household appliances, such as a television, a refrigerator, a washing machine, a vacuum cleaner, an air-conditioning outdoor unit etc. are mentioned. Further, the electronic device is not particularly limited. For example, an image display device such as a liquid crystal display or a plasma display, a mobile phone, a smartphone, a tablet PC (tablet computer), a notebook personal computer, or a portable information terminal. Mobile devices such as (PDA), portable music player, portable game machine, and portable television.

  The optical product has optical characteristics (for example, polarization, light refraction, light scattering, light reflectivity, light transmission, light absorption, light diffraction, optical rotation, visibility, etc.) in the product. The product used. Examples of the optical product include a display device such as a liquid crystal display device, a PDP (plasma display panel) and electronic paper, an input device such as a touch panel, or a device in which these display devices and input devices are appropriately combined. .

  The said optical member means the member which has the said optical characteristic. Examples of the optical member include a member constituting an apparatus (optical apparatus) such as the display device (image display apparatus) and the input device, or a member used in these apparatuses. Examples include a polarizing plate and a wave plate. , Retardation film, optical compensation film, brightness enhancement film, light guide plate, reflection film, antireflection film, transparent conductive film (ITO film), design film, decorative film, surface protection plate, prism, lens, color filter, transparent substrate In addition, members in which these are laminated (these may be collectively referred to as “optical films”) and the like may be mentioned. In addition, said "plate" and "film" shall include forms, such as plate shape, film shape, and sheet shape, respectively, for example, "polarizing film" shall include "polarizing plate" and "polarizing sheet". As described above, the “optical member” in the present invention is a member (design film, decorative film) that plays a role of decoration and protection while maintaining the visibility and excellent appearance of the display unit in the display device or the input device. And surface protective film).

  More specifically, the adhesive tape of the present invention comprises a thin layer display member (for example, a touch panel using an LCD), a thin layer display device (for example, an LCD or a color filter used therefor), an image recognition member, a thin layer. It can be preferably used for surface protection applications such as layer optical films (for example, polarizing plates) and electronic devices (particularly thin-layer electronic devices).

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited at all by these.

Example 1
80 parts by weight of butyl acrylate (BA) and 0.8 parts by weight of acrylic acid (AA) were mixed to obtain an acrylic monomer mixture.
To 80 parts by weight of this acrylic monomer mixture, styrene-isobutylene-styrene copolymer (trade name “SIBSTAR-062M”, manufactured by Kaneka Corporation, weight average molecular weight 60,000, styrene content 20%): 20 parts by weight , Trimethylolpropane triacrylate (TMPTA, polyfunctional monomer): 0.08 parts by weight, alicyclic saturated hydrocarbon resin (trade name “Arcon P125”, manufactured by Arakawa Chemical Industries, Ltd.): 6 parts by weight, 1 -Hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, trade name “Irgacure 184”, manufactured by BASF Japan Ltd.) 0.05 weight, and 2,2-dimethoxy-1,2-diphenylethane-1-one (Photopolymerization initiator, trade name “Irgacure 651”, manufactured by BASF Japan Ltd.) Add 0.05 parts by weight and mix uniformly To obtain an acrylic pressure-sensitive adhesive composition.

The acrylic pressure-sensitive adhesive composition is formed on the release-treated surface of a release liner (trade name “MRF # 38”, manufactured by Mitsubishi Plastics Co., Ltd.) so that the thickness of the pressure-sensitive adhesive layer formed is 50 μm. Was applied to form an acrylic pressure-sensitive adhesive composition layer. Next, a release liner (“MRE # 38”, manufactured by Mitsubishi Resin Co., Ltd.) was bonded to the surface of the acrylic pressure-sensitive adhesive composition layer. Next, ultraviolet light having an illuminance of 5 mW / cm ² was irradiated for 360 seconds using a black light lamp (manufactured by Toshiba Corporation), and the acrylic pressure-sensitive adhesive composition layer was photocured to form an acrylic pressure-sensitive adhesive layer.
The illuminance of ultraviolet rays was adjusted using an industrial UV checker (trade name “UVR-T1”, manufactured by Topcon Technohouse Co., Ltd., having a maximum sensitivity of about 350 nm).
Then, an acrylic pressure-sensitive adhesive tape (a substrate-less type double-sided pressure-sensitive adhesive tape in which both surfaces of the pressure-sensitive adhesive layer were protected with a release liner) was produced.

(Example 2)
38 parts by weight of butyl acrylate (BA), 38 parts by weight of 2-ethylhexyl acrylate (2EHA) and 4 parts by weight of acrylic acid (AA) were mixed to obtain an acrylic monomer mixture.
To 80 parts by weight of this acrylic monomer mixture, styrene-isobutylene-styrene copolymer (trade name “SIBSTAR-062M”, manufactured by Kaneka Corporation, weight average molecular weight 60,000, styrene content 20%): 20 parts by weight , Trimethylolpropane triacrylate (TMPTA, polyfunctional monomer): 0.08 parts by weight, alicyclic saturated hydrocarbon resin (trade name “Arcon P115”, manufactured by Arakawa Chemical Industries, Ltd.): 18 parts by weight, 1 -Hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, trade name “Irgacure 184”, manufactured by BASF Japan Ltd.) 0.05 parts by weight, and 2,2-dimethoxy-1,2-diphenylethane-1- ON (photopolymerization initiator, trade name “Irgacure 651”, manufactured by BASF Japan Ltd.) 0.05 parts by weight, uniformly Combined, to obtain an acrylic pressure-sensitive adhesive composition.

The acrylic pressure-sensitive adhesive composition is formed on the release-treated surface of a release liner (trade name “MRF # 38”, manufactured by Mitsubishi Plastics Co., Ltd.) so that the thickness of the pressure-sensitive adhesive layer formed is 50 μm. Was applied to form an acrylic pressure-sensitive adhesive composition layer. Next, a release liner (“MRE # 38”, manufactured by Mitsubishi Resin Co., Ltd.) was bonded to the surface of the acrylic pressure-sensitive adhesive composition layer. Next, ultraviolet light having an illuminance of 5 mW / cm ² was irradiated for 360 seconds using a black light lamp (manufactured by Toshiba Corporation), and the acrylic pressure-sensitive adhesive composition layer was photocured to form an acrylic pressure-sensitive adhesive layer . Your name, the illuminance of ultraviolet rays, industrial UV checker was adjusted using the (trade name "UVR-T1", Topcon Techno house Co., Ltd., having a maximum sensitivity at about 350nm). Its to and produce an acrylic pressure-sensitive adhesive tape (double-sided adhesive tape of a substrate-less type double-sided pressure-sensitive adhesive layer is protected by a release liner).

(Example 3)
An acrylic monomer mixture was obtained by mixing 59.1 parts by weight of 2-ethylhexyl acrylate (2EHA) and 5.9 parts by weight of acrylic acid (AA).
To 80 parts by weight of this acrylic monomer mixture, styrene-isobutylene-styrene copolymer (trade name “SIBSTAR-062T”, manufactured by Kaneka Corporation, weight average molecular weight 60,000, styrene content 20%): 35 parts by weight , Trimethylolpropane triacrylate (TMPTA, polyfunctional monomer): 0.3 part by weight, alicyclic saturated hydrocarbon resin (trade name “Arcon P125”, manufactured by Arakawa Chemical Industries, Ltd.): 10.5 part by weight , 1-hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, trade name “Irgacure 184”, manufactured by BASF Japan Ltd.) 0.05 parts by weight, and 2,2-dimethoxy-1,2-diphenylethane 1-one (photopolymerization initiator, trade name “Irgacure 651”, manufactured by BASF Japan Ltd.) 0.05 parts by weight was added uniformly. Mixture to give an acrylic adhesive composition.

The acrylic pressure-sensitive adhesive composition is formed on the release-treated surface of a release liner (trade name “MRF # 38”, manufactured by Mitsubishi Plastics Co., Ltd.) so that the thickness of the pressure-sensitive adhesive layer formed is 75 μm. Was applied to form an acrylic pressure-sensitive adhesive composition layer. Next, a release liner (“MRE # 38”, manufactured by Mitsubishi Resin Co., Ltd.) was bonded to the surface of the pressure-sensitive adhesive composition layer. Next, ultraviolet light having an illuminance of 5 mW / cm ² was irradiated for 360 seconds using a black light lamp (manufactured by Toshiba Corporation), and the acrylic pressure-sensitive adhesive composition layer was photocured to form an acrylic pressure-sensitive adhesive layer.
The illuminance of ultraviolet rays was adjusted using an industrial UV checker (trade name “UVR-T1”, manufactured by Topcon Technohouse Co., Ltd., having a maximum sensitivity of about 350 nm).
Then, an acrylic pressure-sensitive adhesive tape (a substrate-less type double-sided pressure-sensitive adhesive tape in which both surfaces of the pressure-sensitive adhesive layer were protected with a release liner) was produced.

(Comparative Example 1)
An acrylic monomer mixture was obtained by mixing 85 parts by weight of 2-ethylhexyl acrylate (2EHA) and 5 parts by weight of acrylic acid (AA).
This acrylic monomer mixture was charged into a four-necked flask. Next, 0.05 part by weight of 1-hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, trade name “Irgacure 184”, manufactured by BASF Japan Ltd.), and 2,2-dimethoxy-1,2-diphenylethane 0.05 parts by weight of -1-one (photopolymerization initiator, trade name “Irgacure 651”, manufactured by BASF Japan Ltd.) was added, and nitrogen gas was injected into the four-necked flask. Next, ultraviolet rays are irradiated in a nitrogen atmosphere to cause photopolymerization, and a partially polymerized monomer syrup (acrylic monomer mixture) having a viscosity (BH viscometer, No. 5 rotor, 10 rpm, temperature 30 ° C.) of about 15 Pa · s. Partial polymer).
To 80 parts by weight of this partially polymerized monomer syrup, styrene-isobutylene-styrene copolymer (trade name “SIBSTAR-062T”, manufactured by Kaneka Corporation, weight average molecular weight 60,000, styrene content 20%): 10 parts by weight , Trimethylolpropane triacrylate (TMPTA, polyfunctional monomer): 0.3 part by weight, 1-hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, trade name “Irgacure 184”, manufactured by BASF Japan Ltd.) 0 0.05 parts by weight, and 2,2-dimethoxy-1,2-diphenylethane-1-one (photopolymerization initiator, trade name “Irgacure 651”, manufactured by BASF Japan Ltd.) are added, It mixed uniformly and the acrylic adhesive composition was obtained.

The acrylic pressure-sensitive adhesive composition is formed on the release-treated surface of a release liner (trade name “MRF # 38”, manufactured by Mitsubishi Plastics Co., Ltd.) so that the thickness of the pressure-sensitive adhesive layer formed is 45 μm. Was applied to form an acrylic pressure-sensitive adhesive composition layer. Next, a release liner (“MRE # 38”, manufactured by Mitsubishi Resin Co., Ltd.) was bonded to the surface of the pressure-sensitive adhesive composition layer. Next, ultraviolet light having an illuminance of 5 mW / cm ² was irradiated for 360 seconds using a black light lamp (manufactured by Toshiba Corporation), and the acrylic pressure-sensitive adhesive composition layer was photocured to form an acrylic pressure-sensitive adhesive layer.
The illuminance of ultraviolet rays was adjusted using an industrial UV checker (trade name “UVR-T1”, manufactured by Topcon Technohouse Co., Ltd., having a maximum sensitivity of about 350 nm).
Then, an acrylic pressure-sensitive adhesive tape (a substrate-less type double-sided pressure-sensitive adhesive tape in which both surfaces of the pressure-sensitive adhesive layer were protected with a release liner) was produced.

(Measurement method of moisture permeability of pressure-sensitive adhesive composition)
The pressure-sensitive adhesive composition was applied on the release-treated surface of a release liner (trade name “MRF # 38”, manufactured by Mitsubishi Plastics Co., Ltd.) so that the thickness of the formed pressure-sensitive adhesive layer was 50 μm. Thus, an adhesive composition layer was formed. Next, a release liner (“MRE # 38”, manufactured by Mitsubishi Resin Co., Ltd.) was bonded to the surface of the pressure-sensitive adhesive composition layer. Next, ultraviolet light with an illuminance of 5 mW / cm ² was irradiated for 360 seconds using a black light lamp (manufactured by Toshiba Corporation), and the pressure-sensitive adhesive composition layer was photocured to form a pressure-sensitive adhesive layer. And the sheet | seat in which both surfaces of the adhesive layer were protected by the release liner was obtained.
The illuminance of ultraviolet rays was adjusted using an industrial UV checker (trade name “UVR-T1”, manufactured by Topcon Technohouse Co., Ltd., having a maximum sensitivity of about 350 nm).
Next, one release liner of this sheet is peeled off to expose the adhesive surface, and bonded to a triacetyl cellulose film (TAC film, thickness 25 μm, manufactured by Konica Minolta Co., Ltd.), release liner, adhesive layer, TAC film A pressure-sensitive adhesive tape laminated in this order was prepared. And the release liner was peeled off from this adhesive tape, and the measurement sample was obtained.
Next, using this measurement sample, moisture permeability (water vapor permeability) was measured by the moisture permeability test method (cup method, conforming to JIS Z 0208) under the following conditions.
Measurement temperature: 40 ° C
Relative humidity: 90%
Measurement time: 24 hours A constant temperature and humidity chamber was used for the measurement.

(Evaluation)
About the adhesive tape obtained by said Example and comparative example, adhesive force etc. were measured. The measurement results are shown in Table 1.

(Measurement of adhesive strength)
A tape piece having a length of 100 mm and a width of 25 mm was obtained from the adhesive tape. Next, one release liner is peeled off from the tape piece, the adhesive surface is exposed, and the adhesive surface of the tape piece is bonded to a PET film (thickness 25 μm), and the release liner, the adhesive layer, and the PET film are adhered. The single-sided adhesive tape with a base material (length 100mm, width 25mm) laminated | stacked in this order was produced. The release liner was peeled from the single-sided adhesive tape with the substrate to obtain a measurement sample.
Next, a glass plate (“Soda Lime Glass # 0050” manufactured by Matsunami Glass Industry Co., Ltd.) is bonded to the exposed adhesive surface (measurement surface) of the measurement sample in an atmosphere of 23 ° C. and 50% RH, and 2 kg. Crimping was performed by reciprocating the roller once. Then, it was left for 30 minutes in an atmosphere of 23 ° C. and 50% RH.
After leaving, using a tensile tester (trade name “TCM-1kNB”, manufactured by Minebea Co., Ltd.), a 180 ° peel test is performed to peel off the measurement sample from the glass plate, and 180 ° peel adhesion to the glass plate (180 °). The peel adhesive strength (N / 25 mm) was measured. The measurement was performed in an atmosphere of 23 ° C. and 50% RH under conditions of a peeling angle of 180 ° and a tensile speed of 300 mm / min.

(Measurement method of gel fraction)
The gel fraction of the pressure-sensitive adhesive layer was measured by the above method.

  In Table 1, the “separation structure” in the column of the phase structure of the acrylic pressure-sensitive adhesive layer means that the acrylic polymer and the isobutylene polymer as a whole are not one phase in the acrylic pressure-sensitive adhesive layer, but the acrylic polymer and isobutylene. This means that the polymer is phase separated.

In Table 1 above, the following expressions have the following meanings.
BA: butyl acrylate 2EHA: 2-ethylhexyl acrylate AA: acrylic acid TMPTA: trimethylolpropane triacrylate SIBSTAR-062M: styrene-isobutylene-styrene copolymer (trade name “SIBSTAR-062M”, manufactured by Kaneka Corporation) , Weight average molecular weight 60,000, styrene content 20%)
SIBSTAR-062T: Styrene-isobutylene-styrene copolymer (trade name “SIBSTAR-062T”, manufactured by Kaneka Corporation, weight average molecular weight 60,000, styrene content 20%)
Alcon P115: Alicyclic saturated hydrocarbon resin (trade name “Arcon P115”, manufactured by Arakawa Chemical Industries, Ltd.)
Alcon P125: Alicyclic saturated hydrocarbon resin (trade name “Arcon P125”, manufactured by Arakawa Chemical Industries, Ltd.)

Claims (6)

An adhesive composition comprising an acrylic monomer mixture or a partial polymer thereof, and a styrene-isobutylene-styrene block copolymer ,
The pressure-sensitive adhesive composition is characterized in that the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition has a moisture permeability measured by the following method of 100 g / m ² · day or less.
Method of measuring moisture permeability: Using a measurement sample obtained by bonding a pressure-sensitive adhesive layer (thickness 50 μm) formed from the pressure-sensitive adhesive composition to a triacetyl cellulose film (thickness 25 μm), JIS Z 0208 Based on the moisture permeability test method, the moisture permeability is measured under the following conditions.
Measurement temperature: 40 ° C
Relative humidity: 90%
Measurement time: 24 hours   The pressure-sensitive adhesive composition according to claim 1, wherein an adhesive force of the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition is 1.0 N / 25 mm or more. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein a content of the styrene-isobutylene-styrene block copolymer is 15 parts by weight or more with respect to 100 parts by weight of the acrylic monomer mixture or a partial polymer thereof.   The pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition has a crosslinked structure.   The pressure-sensitive adhesive composition according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition has a gel fraction of 20% by weight or more.   It has an adhesive layer formed from the adhesive composition of any one of Claims 1-5, The adhesive tape or sheet | seat characterized by the above-mentioned.