KR102182529B1 - Pressure-sensitive-adhesive sheet - Google Patents

Abstract

After the adhesive sheet is bonded to an adherend, there is provided a pressure-sensitive adhesive sheet having sufficient adhesiveness and excellent moisture-proof properties without the need for treatment such as heat treatment or ultraviolet treatment. The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer containing a base polymer and a layered silicate, and the base polymer is a polyolefin-based resin. In the pressure-sensitive adhesive sheet, it is preferable that the adhesive force is 3.0 gf/25 mm or more and the transmittance is 80% or more.

Description

Adhesive sheet {PRESSURE-SENSITIVE-ADHESIVE SHEET}

The present invention relates to an adhesive sheet. More specifically, it relates to a pressure-sensitive adhesive sheet having excellent moisture-proof properties.

Conventionally, it is known to use an epoxy cured resin as a moisture-proof adhesive or pressure-sensitive adhesive (see Patent Document 1 and Patent Document 2). However, since the epoxy cured resin requires curing treatment such as heat treatment or ultraviolet treatment (UV treatment) after bonding in order to secure adhesion, it is difficult to use for those that are weak to heat or ultraviolet rays, and it is difficult to use the curing conditions. There was a problem in securing adhesion.

Further, in recent years, in the field of a moisture-proof adhesive sheet, a higher level of moisture-proof property has been required.

Japanese Patent Application Publication No. 2010-126699 Japanese Patent Application Publication No. 2012-151109

Accordingly, an object of the present invention is to provide a pressure-sensitive adhesive sheet having sufficient adhesiveness and excellent moisture-proof properties without the need for heat treatment or ultraviolet treatment after bonding the pressure-sensitive adhesive sheet to an adherend.

Therefore, as a result of intensive examination by the present inventors, in a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer, when the base polymer contained in the pressure-sensitive adhesive layer is made of a polyolefin resin, and the layered silicate is contained in the pressure-sensitive adhesive layer, curing treatment (adhesive sheet is used as an adherend) It was found that a pressure-sensitive adhesive layer having excellent moisture-proof properties was obtained, which was unnecessary, and the present invention was completed.

That is, the present invention has a pressure-sensitive adhesive layer containing a base polymer and a layered silicate,

It provides a pressure-sensitive adhesive sheet, characterized in that the base polymer is a polyolefin-based resin.

In the adhesive sheet, it is preferable that the adhesive force is 3.0 gf/25 mm or more and the transmittance is 80% or more.

In the pressure-sensitive adhesive sheet, it is preferable that the moisture permeability determined below is 125 g/m 2 ·day or less.

Moisture permeability: Using a sample for measurement obtained by bonding a pressure-sensitive adhesive sheet having a thickness of 35 μm of the pressure-sensitive adhesive layer to a triacetylcellulose film (25 μm in thickness), it is determined by a moisture permeability test method (cup method) under the following conditions.

Measurement temperature: 40℃

Relative humidity: 90%

Measurement time: 24 hours

The polyolefin resin preferably has at least one functional group selected from the group consisting of a hydroxyl group, an amino group, an epoxy group, a carboxyl group, an acid anhydride group, and a silyl group in the main chain.

It is preferable that the pressure-sensitive adhesive layer has a crosslinked structure.

Since the pressure-sensitive adhesive sheet of the present invention has the above configuration, it exhibits sufficient adhesiveness and is excellent in moisture-proof properties. In addition, there is no need for heat treatment or ultraviolet treatment after bonding the adhesive sheet to the adherend.

[Adhesive sheet]

The adhesive sheet of the present invention has a base polymer of a polyolefin resin, and an adhesive layer containing a base polymer and a layered silicate. That is, it is preferable that the pressure-sensitive adhesive sheet of the present invention has at least a polyolefin-based pressure-sensitive adhesive layer containing a layered silicate as the pressure-sensitive adhesive layer. In addition, in this specification, the said "adhesive layer containing a base polymer and a layered silicate, and the base polymer is a polyolefin resin" may be called "adhesive agent layer A".

In addition to the pressure-sensitive adhesive layer A, the pressure-sensitive adhesive sheet of the present invention may have a layer made of a base material, a pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer A (other pressure-sensitive adhesive layers), and other layers (for example, an intermediate layer, an undercoat layer, etc.). In addition, the pressure-sensitive adhesive layer surface (adhesive surface) of the pressure-sensitive adhesive sheet of the present invention may be protected by a release liner.

In addition, in this specification, "adhesive sheet" shall also include the meaning of "adhesive tape". That is, in this specification, the adhesive sheet may be an adhesive sheet having a tape-like (wound body) form. In addition, in this specification, the composition used when forming the adhesive layer A may be called "adhesive composition A". The pressure-sensitive adhesive composition is a composition used for forming the pressure-sensitive adhesive layer, and includes the meaning of the composition used for forming the pressure-sensitive adhesive.

The pressure-sensitive adhesive sheet of the present invention may be a pressure-sensitive adhesive sheet having a substrate (a pressure-sensitive adhesive sheet with a substrate), or may be a pressure-sensitive adhesive sheet without a substrate (a pressure-sensitive adhesive sheet without a substrate). As the pressure-sensitive adhesive sheet of the present invention, for example, (1) a pressure-sensitive adhesive sheet containing only the pressure-sensitive adhesive layer A and having no substrate (a double-sided pressure-sensitive adhesive sheet containing only the adhesive layer A), and (2) at least one side of the substrate ( A pressure-sensitive adhesive sheet (a single-sided pressure-sensitive adhesive sheet with a base material, a double-sided pressure-sensitive adhesive sheet with a base material) and the like having the pressure-sensitive adhesive layer A on both sides or one side). In addition, when the adhesive sheet of the present invention is a double-sided adhesive sheet, the adhesive sheet of the present invention may have a form in which both adhesive surfaces are provided by the adhesive layer A, one adhesive surface is provided by the adhesive layer A, and the other The side adhesive surface may have a form provided by another adhesive layer (adhesive layer other than the adhesive layer A).

(Adhesive layer A)

The pressure-sensitive adhesive sheet of the present invention has at least the pressure-sensitive adhesive layer A. The pressure-sensitive adhesive layer A contains a polyolefin resin as a base polymer. In addition, the pressure-sensitive adhesive layer A contains at least a layered silicate as components other than the base polymer.

The proportion of the base polymer in the pressure-sensitive adhesive layer A is not particularly limited, but from the viewpoint of obtaining sufficient adhesiveness, it is preferably 20% by weight or more with respect to the total amount (total weight, 100% by weight) of the pressure-sensitive adhesive layer A, more preferably It is 25% by weight or more, more preferably 30% by weight or more.

In the pressure-sensitive adhesive sheet of the present invention, the base polymer in the pressure-sensitive adhesive layer A is a polyolefin resin. Since the pressure-sensitive adhesive layer A contains a polyolefin-based resin as a base polymer, it has sufficient adhesiveness and excellent moisture-proof property. In addition, the pressure-sensitive adhesive layer A may contain resins other than polyolefin-based resins within a range that does not impair the effects of the present invention. For example, acrylic resins, vinyl alkyl ether resins, silicone resins, polyester resins, polyamide resins, urethane resins, fluorine resins, epoxy resins, etc., are included within the range not impairing the effects of the present invention. You may have it. Further, the polyolefin resin as the base polymer can be used alone or in combination of two or more.

The polyolefin resin as the base polymer is a polymer having a structural unit derived from an olefin. In addition, an aromatic vinyl compound such as styrene is also included in the "olefin". Moreover, the said polyolefin resin can be used individually or in combination of 2 or more types.

Examples of the polyolefin resin include an α-olefin homopolymer formed from one monomer selected from the group consisting of ethylene, propylene, 1-butene, 2-methylpropene, 1-hexene and α-olefin. have. Although it does not specifically limit as an α-olefin, For example, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, 1 -Decene, 1-dodecene, and the like.

Further, examples of the polyolefin resin include polyethylene, polypropylene, poly-1-butene, and polyisobutylene.

Further, examples of the polyolefin-based resin include an α-olefin copolymer formed of at least two monomers selected from the group consisting of ethylene, propylene, and α-olefin. More specifically, a copolymer containing ethylene as a main monomer (ethylene α-olefin copolymer), a copolymer containing propylene as a main monomer (propylene α-olefin copolymer), and the like can be cited. Further, the α-olefin copolymer may be any of a random copolymer, a block copolymer, or a graft copolymer.

In addition, as the polyolefin resin, a block A mainly containing a structural unit derived from an aromatic vinyl compound (hereinafter, sometimes referred to as an ``aromatic vinyl compound unit'') and a structural unit derived from isoprene (hereinafter, `` Hydrogen of a block copolymer containing block B containing a structural unit derived from 1,3-butadiene (hereinafter sometimes referred to as a ``1,3-butadiene unit'') and a structural unit derived from 1,3-butadiene. An additive (it may be called "hydrogenated TPE") is mentioned.

Moreover, as said polyolefin resin, a styrene-type thermoplastic elastomer is also mentioned. Examples of the styrene-based thermoplastic elastomer include a styrene-type AB diblock copolymer (diblock copolymer) such as a styrene-butadiene copolymer (SB), a styrene-isoprene copolymer (SI), and a styrene-butylene copolymer. ; Styrene-based ABA block copolymers (triblock copolymers) such as styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), and styrene-butylene-styrene copolymer; Styrene ABAB type block copolymers (tetra block copolymers) such as styrene/butadiene/styrene/butadiene copolymer (SBSB) and styrene/isoprene/styrene/isoprene copolymer (SISI); Styrene-based ABABA block copolymers (penta block copolymers) such as styrene-butadiene-styrene-butadiene-styrene copolymer (SBSBS) and styrene-isoprene-styrene-isoprene-styrene copolymer (SISIS); Multi-block copolymers having these structural units; Styrene-butadiene copolymer; A styrene-isoprene random copolymer, etc. are mentioned.

Moreover, as said styrene-type thermoplastic elastomer, what hydrogenated an ethylenic double bond is mentioned preferably. Examples of such hydrogenated substances include hydrogenated substances of AB type diblock copolymers such as styrene/ethylene-butylene copolymer (SEB) and styrene/ethylene-propylene copolymer (SEP); ABA such as styrene·ethylene-butylene copolymer·styrene (SEBS), styrene·ethylene-propylene copolymer·styrene (SEPS), styrene·ethylene-butylene copolymer·styrene·ethylene-butylene copolymer (SEBSEB) Hydrogenated products of type triblock copolymer or ABAB type tetra block copolymer; Styrene-ethylene-butylene random copolymer (HSBR), etc. are mentioned.

In addition, examples of the styrene-based thermoplastic elastomer include styrene-based random copolymers such as styrene-butadiene rubber (SBR), and ABC-type styrene-olefin crystal-based block copolymers such as styrene-ethylene-butylene copolymers and olefin crystals (SEBC). ; And these hydrogenated substances.

Moreover, as said polyolefin resin, a polyolefin resin which has a hydroxyl group in a main chain is mentioned. Examples of the polyolefin resin having a hydroxyl group in such a main chain include polyethylene polyol, polypropylene polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, polyisoprene polyol, hydrogenated polyisoprene polyol, and the like.

Particularly, the polyolefin-based resin is preferably a polyolefin-based resin containing no double bonds in the main chain or a hydrogenated polyolefin-based resin from the viewpoint of weather resistance and moisture permeability of the pressure-sensitive adhesive layer.

In addition, the polyolefin-based resin has a hydroxyl group (hydroxyl group), an amino group, an epoxy group, a carboxyl group, and an acid anhydride group in the main chain from the point that it is easy to obtain an adhesive layer having a crosslinked structure and an adhesive layer having good thermal stability. It is preferable to have at least one functional group selected from the group consisting of silyl groups. For example, the polyolefin resin is preferably a polyolefin resin having a functional group such as a hydroxyl group in the main chain.

The pressure-sensitive adhesive layer A of the pressure-sensitive adhesive sheet of the present invention contains at least a layered silicate together with the base polymer. The layered silicate is a plate-like substance having a structure in which silicates are laminated in a layered form through ions. Since the pressure-sensitive adhesive layer A of the pressure-sensitive adhesive sheet of the present invention contains a layered silicate together with the base polymer, the moisture permeability can be made smaller. This means that the layered silicate itself does not transmit water vapor, and the layered silicate contained in the adhesive layer blocks, lengthens, or narrows the path of water vapor when water vapor tries to pass through the adhesive layer. It is presumed that it is because it inhibits the passage of the layer.

Although it does not specifically limit as said layered silicate, For example, montmorillonite, hectorite, saponite, sauconite, videlite, stevensite, nontronite, borjonscoite, sauconite, margadiite, Medomontite, Kenite, Chlorite, Phlogopite, Lepidolite, Muscobite, Biotite, Paragonite, Margarite, Teniolite, Tetrasilic Mica, Trioctahedral Vermiculite, Diocta Hemoral vermiculite, muscovite mica, biotite, paragonite, levilite, margarite, cleantonite, anandite, and the like. In addition, layered silicates can be used alone or in combination of two or more.

In addition, it is preferable that the surface of the layered silicate is organically treated. When the layered silicate is subjected to an organic treatment, it is more likely to be compatible with the base polymer of the pressure-sensitive adhesive layer A, and it is more likely to be dispersed by the pressure-sensitive adhesive layer A. For this reason, the moisture-proof property in the pressure-sensitive adhesive layer A can be further improved, and in the pressure-sensitive adhesive layer A, fluctuations in moisture-proof properties by location are suppressed, and uniform moisture-proof properties are easily obtained. In addition, the transparency of the pressure-sensitive adhesive layer A can be further improved.

Although it does not specifically limit as such organizing treatment, For example, treatment with alkyl ammonium, treatment with quaternary ammonium, etc. are mentioned. In addition, a plurality of organic treatments may be performed.

Although the content of the layered silicate in the pressure-sensitive adhesive layer A of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, it is preferably 1 to 50 parts by weight, more preferably 2 to 40 parts by weight based on 100 parts by weight of the base polymer in the pressure-sensitive adhesive layer A. Parts, more preferably 3 to 30 parts by weight.

In addition, the pressure-sensitive adhesive layer A preferably contains a tackifying resin from the viewpoint of obtaining sufficient adhesiveness. Although it does not specifically limit as a tackifier resin, For example, rosin, rosin derivative resin, polyterpene resin, petroleum resin, coumarone-inden resin, styrene resin, phenol resin, xylene resin, etc. are mentioned. Moreover, tackifying resin can be used individually or in combination of 2 or more types.

In particular, as the tackifying resin, a hydrogenated tackifying resin is preferably mentioned from the viewpoint of compatibility with the base polymer and moisture permeability. Although it does not specifically limit as said hydrogenation type tackifying resin, For example, tackifier resins, such as rosin-type resin, petroleum-type resin, terpene-type resin, coumarone-indene-type resin, styrene-type resin, alkylphenol resin, xylene resin Derivatives (hydrogenated rosin resin, hydrogenated petroleum resin, hydrogenated terpene resin, etc.) are mentioned. Examples of the hydrogenated rosin-based tackifying resin include modified rosin in which unmodified rosin (raw rosin) such as gum rosin, wood rosin and tall oil rosin is modified by hydrogenation.

Although the softening point of the said tackifying resin is not specifically limited, For example, 80-200 degreeC is preferable, More preferably, it is 90-200 degreeC. When the softening point of the tackifying resin is within the range, the cohesive strength is further improved.

Although the content of the tackifying resin in the pressure-sensitive adhesive layer A of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, it is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 50 parts by weight based on 100 parts by weight of the base polymer in the pressure-sensitive adhesive layer A. It is 30 parts by weight.

In addition, it is preferable that the pressure-sensitive adhesive layer A contains a crosslinking agent from the viewpoint of obtaining a crosslinked structure. Although it does not specifically limit as a crosslinking agent, For example, an epoxy type crosslinking agent, an isocyanate type crosslinking agent, a silicone type crosslinking agent, an oxazoline type crosslinking agent, an aziridine type crosslinking agent, a silane type crosslinking agent, an alkyl etherified melamine type crosslinking agent, a metal chelate type crosslinking agent, etc. are mentioned. have. In addition, crosslinking agents can be used alone or in combination of two or more.

Among them, the crosslinking agent is preferably an epoxy crosslinking agent or an isocyanate crosslinking agent. In particular, when the base polymer of the pressure-sensitive adhesive layer A is a polyolefin-based resin having a hydroxyl group in its main chain, an isocyanate-based crosslinking agent is preferable.

As the isocyanate crosslinking agent, for example, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetra Methyl xylylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate, and adducts of these with polyols such as trimethylolpropane. Further, compounds having at least one or more isocyanate groups and one or more unsaturated bonds per molecule, specifically 2-isocyanatoethyl (meth)acrylate, and the like are also mentioned.

Examples of the epoxy crosslinking agent include bisphenol A, epichlorohydrin type epoxy resin, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1, 6-hexanediol glycidyl ether, trimethylolpropane triglycidyl ether, diglycidylaniline, diamine glycidylamine, N,N,N′,N′-tetraglycidyl-m-xylylenediamine And 1,3-bis(N,N'-diamineglycidylaminomethyl)cyclohexane.

Although the content of the crosslinking agent in the pressure-sensitive adhesive layer A of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, it is preferably 0.01 to 80 parts by weight, more preferably 0.1 to 50 parts by weight based on 100 parts by weight of the base polymer in the pressure-sensitive adhesive layer A. It is wealth.

In addition, the pressure-sensitive adhesive layer A may contain an additive depending on the use or the like within a range that does not impair the effects of the present invention. Examples of such additives include dispersants, surfactants, silane coupling agents, plasticizers, chain transfer agents, anti-aging agents, softeners, antioxidants, ultraviolet absorbers, antistatic agents, stabilizers, colorants (pigments, dyes, etc.). Further, the additives may be used alone or in combination of two or more.

The pressure-sensitive adhesive layer A of the pressure-sensitive adhesive sheet of the present invention is formed of the pressure-sensitive adhesive composition A. The pressure-sensitive adhesive composition A is a composition used for formation of the pressure-sensitive adhesive layer A, and preferably contains at least the base polymer and the layered silicate. The pressure-sensitive adhesive composition A is not particularly limited, but can be obtained, for example, by mixing the base polymer, the layered silicate, and a dilute solvent.

The viscosity of the pressure-sensitive adhesive composition A is not particularly limited, but from the viewpoints of workability, handling properties, ease of formation of a uniform pressure-sensitive adhesive layer, and dispersibility of the layered silicate, 0.1 to 100 Pa·s is preferable, and more preferably 0.5 to 50 Pa. ·S. In addition, in the present specification, the viscosity refers to a BH viscometer as a viscometer, and rotor: No. It refers to the viscosity measured under the conditions of 5 rotor, rotational speed: 10 rpm, and measurement temperature: 30°C.

The viscosity of the pressure-sensitive adhesive composition A may be adjusted by blending various polymer components such as acrylic rubber and thickening additive.

The pressure-sensitive adhesive layer A is formed by curing the pressure-sensitive adhesive composition A as a layer. For example, it is formed by obtaining a pressure-sensitive adhesive composition layer from the pressure-sensitive adhesive composition A, and heat-drying the pressure-sensitive adhesive composition layer (eg, heat treatment at a temperature of 80 to 140°C for 1 to 10 minutes).

The thickness of the pressure-sensitive adhesive layer A is not particularly limited, but from the viewpoint of adhesion reliability, it is preferably 5 to 200 µm, and more preferably 10 to 100 µm.

It is preferable that the adhesive layer A of the adhesive sheet of this invention has a crosslinked structure. When the pressure-sensitive adhesive layer A has a crosslinked structure, the thermal stability of the pressure-sensitive adhesive layer can be further improved. For example, even if it is used under a high temperature environment (for example, under a temperature environment of 80 to 100°C), it is possible to effectively suppress the occurrence of a problem that the pressure-sensitive adhesive flows and peels off. The crosslinked structure can be obtained, for example, by using a crosslinking agent.

(materials)

As described above, the adhesive sheet of the present invention may be an adhesive sheet having a base material having at least a base material and an adhesive layer A. Although it does not specifically limit as a base material used for the adhesive sheet with such a base material, a plastic base material (polymer base material) is mentioned preferably. In addition, the base material may be a base material consisting of one layer or may have a laminated structure of two or more layers.

Although it does not specifically limit as a material which comprises the said plastic base material, For example, polyester, such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate; Polyolefins such as polyethylene, polypropylene, and 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; Fluorine resin; Polyether; Polyetheramide; Polyetheretherketone; Polyphenylene sulfide; Polystyrene resins such as polystyrene; Polycarbonate; Polyethersulfone; Acrylic resins, such as polymethyl methacrylate, etc. are mentioned. Further, the above materials can be used alone or in combination of two or more.

Among them, as a material constituting the plastic substrate, polyester, cellulose, acrylic resin, etc. are preferable, and more preferable from the viewpoint of having a good balance of strength, handling properties (handling properties), cost, dimensional stability, and penetration power. Examples are polyethylene terephthalate (PET), triacetyl cellulose (TAC), and polymethyl methacrylate (PMMA). That is, the substrate is preferably a polyethylene terephthalate substrate, a triacetyl cellulose substrate, or a polymethyl methacrylate substrate.

The substrate may be subjected to a surface treatment as necessary. For example, the plastic substrate as a substrate may have deformability controlled by stretching treatment (uniaxial stretching or biaxial stretching) or the like. In addition, in order to increase the adhesion with the pressure-sensitive adhesive layer on the surface of the substrate, conventional surface treatments such as chromic acid treatment, ozone exposure, flame exposure, high pressure electric shock exposure, oxidation treatment by chemical or physical methods such as ionizing radiation treatment, etc. This may be implemented. Furthermore, a primer treatment may be applied to increase the adhesion to the pressure-sensitive adhesive layer.

In addition, the substrate may be subjected to a hard coating treatment in order to improve the scratch resistance (abrasion resistance) of the surface. When such a hard coating treatment is performed, the protective function can be further improved when used for surface protection. Further, the substrate may be subjected to an antistatic treatment in order to suppress 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 side and a hard coat treatment on the other side in order to improve the adhesion with the pressure-sensitive adhesive layer.

(Peel liner)

As described above, in order to protect the adhesive surface of the adhesive sheet of the present invention, a release liner may be provided. The release liner is not particularly limited, and a known or conventional release liner can be used. For example, examples of the release liner include polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); Olefin resins containing α-olefins as a monomer component such as polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), ethylene-propylene copolymer, and 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 resin; Polyetheretherketone (PEEK); Olefin resins such as polyethylene (PE) and polypropylene (PP); Fluorine resins such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and chlorofluoroethylene-vinylidene fluoride copolymer The plastic film to be constituted is preferably mentioned.

In addition, as the release liner, for example, a release liner having a release layer (release treatment layer) on at least one surface of the release liner substrate, a low adhesion release liner containing a fluorine-based polymer, and a low adhesion release containing a non-polar polymer Liners, etc. are also mentioned. Moreover, a release liner base material which does not have a release layer (that is, the release liner base material itself) is also mentioned. Although it does not specifically limit as said fluoropolymer, For example, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chlorofluoro And an ethylene-vinylidene fluoride copolymer. Moreover, although it does not specifically limit as said non-polar polymer, For example, olefin resins, such as polyethylene (PE) and polypropylene (PP), etc. are mentioned. Among them, it is preferable to use a release liner having a release layer on at least one surface of the release liner base material, and a release liner base material having no release layer (ie, the release liner base material 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); Olefin resins containing α-olefins as a monomer component such as polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), ethylene-propylene copolymer, and 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 resin; And a plastic film composed of polyether ether ketone (PEEK) or the like. Among them, from the viewpoints of processability, availability, workability, dustproofness, cost and the like, a plastic film formed of 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 a release treatment agent such as a silicone release treatment agent, a fluorine release treatment agent, a long-chain alkyl release treatment agent, and molybdenum sulfide. Among them, from the viewpoint of peeling control and stability over time, a silicone-based peeling treatment agent is preferable. In addition, the peeling treatment agent can be used alone or in combination of two or more.

The release liner can be manufactured by a known conventional method. In addition, the thickness of the release liner is not particularly limited.

(Adhesive sheet)

The manufacturing method of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, but a known forming method can be used. For example, when the adhesive sheet of the present invention is an adhesive sheet with a substrate, it can be produced by forming an adhesive layer A from the adhesive composition A on at least one side of the substrate. In addition, when the pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet containing only the pressure-sensitive adhesive layer A, it can be produced by forming the pressure-sensitive adhesive layer A from the pressure-sensitive adhesive composition A on the release liner.

In the pressure-sensitive adhesive sheet of the present invention, the moisture permeability obtained below is not particularly limited, but it is preferably 125 g/m 2 ·day or less from the viewpoint of obtaining excellent moisture-proof properties.

Moisture permeability: Using a sample for measurement obtained by bonding a pressure-sensitive adhesive sheet having a thickness of 35 μm of the pressure-sensitive adhesive layer to a triacetylcellulose film (25 μm in thickness), it is determined by a moisture permeability test method (cup method) under the following conditions.

Measurement temperature: 40℃

Relative humidity: 90%

Measurement time: 24 hours

In addition, in the pressure-sensitive adhesive sheet of the present invention, it is preferable that the pressure-sensitive adhesive layer A has the moisture permeability.

The adhesive strength of the pressure-sensitive adhesive sheet of the present invention (measurement temperature: 23°C, relative humidity: 50% RH, tensile speed: 300 mm/min, peeling angle: 180° peeling condition, versus glass plate) is not particularly limited, but good adhesion reliability From the viewpoint of obtaining, it is preferably 1.0 gf/25 mm or more, and more preferably 3.0 gf/25 mm or more. In addition, in the adhesive sheet of the present invention, it is preferable that the adhesive force on the adhesive surface provided by the adhesive layer A satisfies the above range.

It is preferable that the pressure-sensitive adhesive sheet of the present invention is transparent.

Further, the transmittance (total light transmittance in the visible light wavelength range, according to JIS K7361-1) of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, but is preferably 80% or more from the viewpoint of obtaining high transparency. In addition, for the transmittance, for example, the adhesive sheet of the present invention was bonded to a slide glass (article number "S-1112", manufactured by Matsunami Glass Kogyo Co., Ltd., thickness 1.0 mm, haze 0.1%), and a haze meter Shikigaisha Murakami Shikisai Kijutsu Kenkyujo, brand name "HM-150") can be used to measure.

Particularly, the pressure-sensitive adhesive sheet of the present invention preferably has an adhesive strength of 3.0 gf/25 mm or more and the transmittance of 80% or more from the viewpoint of achieving both sufficient adhesion and transparency to an adherend.

The thickness of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, but is preferably 5 to 200 µm, and more preferably 10 to 100 µm.

Since the pressure-sensitive adhesive sheet of the present invention has the pressure-sensitive adhesive layer A, it exhibits sufficient adhesion to an adherend and is excellent in moisture-proof properties. In addition, after bonding the pressure-sensitive adhesive sheet to the adherend, it is not necessary to perform treatment (curing treatment) such as heat treatment or ultraviolet ray treatment in order to exhibit adhesion or to further improve adhesion.

The pressure-sensitive adhesive sheet of the present invention exhibits sufficient adhesiveness to an adherend and is excellent in moisture-proof properties, and thus can be used for surface protection or reinforcing purposes. For example, the pressure-sensitive adhesive sheet of the present invention can be used as a surface protection film or a reinforcing film.

In addition, since the pressure-sensitive adhesive sheet of the present invention has the above properties, it can be used in various fields. For example, it can be used for electric or electronic devices. In particular, it can be suitably used for surface protection applications in the manufacture of electric or electronic devices, and surface protection applications in the use of electrical or electronic devices. Further, it can be suitably used for optical applications (for example, for surface protection applications in the manufacture of optical products and optical members, and for surface protection applications in use of optical products and optical members).

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

The optical product refers to a product in which optical properties (for example, polarization, light refraction, light scattering, light reflectivity, light transmittance, light absorption, light diffraction, optical rotation, visibility, etc.) are used in the product. Examples of the optical product include display devices such as a liquid crystal display device, a plasma display panel (PDP), and electronic paper, an input device such as a touch panel, or an appropriate combination of these display devices and input devices. have.

The optical member refers to a member having the optical properties. Examples of the optical member include members constituting devices (optical devices) such as the display device (image display device) and the input device, or members used in these devices. For example, a polarizing plate and a wave plate , Retardation plate, optical compensation film, brightness enhancement film, light guide plate, reflective film, anti-reflection film, transparent conductive film (ITO film), design film, decorative film, surface protection plate, prism, lens, color filter, transparent substrate, etc. The laminated members (these may be collectively referred to as "optical film"), etc. are mentioned. In addition, the said "plate" and "film" are what each includes a form, such as a plate shape, a film shape, and a sheet shape, For example, a "polarization film" is what contains a "polarization plate" and a "polarization sheet". do. In addition, in the ``optical member'' in the present invention, as described above, a member (design film, decorative film or surface) that plays a role of decoration or protection while maintaining the visibility and excellent appearance of the display unit in the display device or the input device. A protective film, etc.) shall also be included.

More specifically, the pressure-sensitive adhesive sheet of the present invention includes 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 therein), an image recognition member, and a thin-layer optical. It can be used for surface protection applications such as films (eg, polarizing plates) and electronic devices (especially thin-layer electronic devices).

Example

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited at all by these.

(Example 1)

Polyolefin resin (hydroxyl-terminated liquid polyolefin, brand name ``Epol'', manufactured by Idemitsu Kosan Corporation): 100 parts by weight, isocyanate-based crosslinking agent (trade name ``Duranate TSE-100'', manufactured by Asahi Kasei Corporation): 30% by weight Part, tin catalyst (trade name ``OL-1'', manufactured by Tokyo Fine Chemical Co., Ltd.): 0.03 parts by weight, layered silicate (trade name ``Organite'', manufactured by Hojun Co., Ltd.): 5 parts by weight and tackifying resin (alicyclic Group saturated hydrocarbon resin, brand name "Alcon P-125", manufactured by Arakawa Chemical Industry Co., Ltd.): 1 part by weight was mixed to obtain a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition was applied on the release-treated side of a release liner (a release liner subjected to a release treatment on one side of a polyethylene terephthalate base material, brand name ``Diare Foil MRF-38'', Mitsubishi Jushi Co., Ltd.), and a coating layer ( A pressure-sensitive adhesive composition layer) was obtained.

Subsequently, heat treatment (temperature: 130° C., time 3 minutes) was performed to form a pressure-sensitive adhesive layer having a thickness of 35 μm.

And a release liner was bonded on the obtained adhesive layer, and the adhesive sheet (double-sided adhesive sheet containing only an adhesive layer) was obtained in which both surfaces of the adhesive layer were protected by the release liner.

(Example 2)

As a layered silicate, a layered silicate (brand name "S-Ben NZ", manufactured by Hojun Corporation): Except having used 5 parts by weight, it carried out similarly to Example 1, and obtained the adhesive sheet.

(Example 3)

As a layered silicate, a layered silicate (trade name "Sben NX", manufactured by Hojun Co., Ltd.): Except having used 5 parts by weight, it carried out similarly to Example 1, and obtained the adhesive sheet.

(Comparative Example 1)

Except having not used the layered silicate, it carried out similarly to Example 1, and obtained the adhesive sheet.

(evaluation)

The following measurement or evaluation was performed about the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples. And the results are shown in Table 1.

(Measurement method of moisture permeability)

One release liner of the pressure-sensitive adhesive sheet was peeled off to expose the pressure-sensitive adhesive surface, and the pressure-sensitive adhesive sheet (thickness of the adhesive layer: 35 μm) was formed into a triacetylcellulose film (TAC film, 25 μm in thickness, Konica Minolta Co., Ltd.) Manufacturing). And the other release liner was peeled off, and the sample for measurement was obtained.

Next, using this sample for measurement, the moisture permeability (water vapor transmittance) was measured by the moisture permeability test method (cup method, conforming to JIS Z 0208) under the following conditions.

Measurement temperature: 40℃

Relative humidity: 90%

Measurement time: 24 hours

In addition, at the time of measurement, a constant temperature and humidity tank was used.

(Measurement of adhesion)

From the adhesive sheet, a sheet piece having a length of 100 mm and a width of 25 mm was obtained. Next, one release liner was peeled from the sheet piece, the adhesive surface was exposed, and the sheet piece was bonded to the PET film (thickness 25 µm) by the adhesive surface. Then, a sample for measurement having a laminated structure of a release liner/adhesive layer/PET film was obtained.

Subsequently, in an atmosphere of 23° C. and 50% RH, the release liner is peeled from the sample for measurement, the adhesive surface (measurement surface) is exposed, and the sample for measurement is applied to a glass plate (soda-lime glass #0050, Matsunami Glass Kogyo (manufactured by Co., Ltd.) was pressed and bonded by 1 reciprocating a 2 kg roller.

After allowing the measurement sample to stand for 30 minutes in an atmosphere of 23°C and 50%RH, a 180° peel test was performed using a tensile tester (trade name “TCM-1kNB”, manufactured by Minevea), and 180° peeling against a glass plate Adhesive force (180 degree peel adhesion) (gf/25mm) was measured. The measurement was performed under conditions of 23°C and 50% RH atmosphere, a peel angle of 180°, and a tensile speed of 300 mm/min.

(Measurement of transmittance)

One release liner of the pressure-sensitive adhesive sheet was peeled off to expose the pressure-sensitive adhesive surface, and the pressure-sensitive adhesive sheet was put on a slide glass (article number ``S-1112'', manufactured by Matsunami Glass Co., Ltd., thickness 1.0 mm, haze 0.1). %). And the other release liner was peeled off, and the sample for measurement was obtained.

Subsequently, the transmittance (total light transmittance) was measured with a haze meter (equipment name "HM-150", manufactured by Murakami Shikisai Kijutsu Kenkyujo Co., Ltd.).

In Table 1, the following expressions have the following meanings.

Epol: Polyolefin resin (liquid polyolefin with hydroxyl group, brand name "Epol", manufactured by Idemitsu Kosan Co., Ltd.)

TSE-100: Isocyanate crosslinking agent (brand name "Duranate TSE-100", manufactured by Asahi Kasei Co., Ltd.)

OL-1: Tin catalyst (trade name "OL-1", manufactured by Tokyo Fine Chemical Co., Ltd.)

Alcon P125: tackifying resin (alicyclic saturated hydrocarbon resin, brand name "Alcon P-125", manufactured by Arakawa Chemical Co., Ltd.)

Organite: Layered silicate (brand name "Organite", manufactured by Hojun Corporation)

NZ: Layered silicate (brand name ``S-Ben NZ'', manufactured by Hojun Corporation)

NX: Layered silicate (trade name ``Esven NX'', manufactured by Hojun Co., Ltd.)

In contrast to Examples 1 to 3 and Comparative Example 1, since Examples 1 to 3 contained layered silicate, the moisture permeability was reduced by about 20%.

The pressure-sensitive adhesive sheet of the present invention exhibits sufficient adhesiveness and is excellent in moisture-proof properties without the need for heat treatment or ultraviolet treatment after bonding the pressure-sensitive adhesive sheet to an adherend. For this reason, it can be suitably used for surface protection use, reinforcement use, etc.

Claims (5)

It has a pressure-sensitive adhesive layer containing a reaction product of a hydroxyl group-containing polyolefin-based resin and an isocyanate-based crosslinking agent as a base polymer, a layered silicate and a tackifying resin, and the content of the layered silicate is 1 to 50 parts by weight based on 100 parts by weight of the base polymer. And the content of the tackifying resin is 0.1 to 30 parts by weight based on 100 parts by weight of the base polymer. The pressure-sensitive adhesive sheet according to claim 1, which has an adhesive force of 3.0 gf/25 mm or more and a transmittance of 80% or more. The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the moisture permeability determined below is 125 g/m 2 ·day or less.
Moisture permeability: Using a sample for measurement obtained by bonding an adhesive sheet having a thickness of an adhesive layer of 35 µm to a triacetylcellulose film (25 µm in thickness), it is determined by a moisture permeability test method (cup method) under the following conditions.
Measuring temperature: 40℃
Relative humidity: 90%
Measurement time: 24 hours delete The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the pressure-sensitive adhesive layer has a crosslinked structure.