JP6592070B2 - Adhesive sheet, electronic device member laminate, and optical member laminate - Google Patents

Description

  The present invention relates to a pressure-sensitive adhesive sheet, an electric or electronic device member laminate, and an optical member laminate. Specifically, the pressure-sensitive adhesive sheet is thin, has both processability (particularly punching processability) and unevenness followability, an electronic device member laminate having the pressure-sensitive adhesive sheet, and an optical member laminate having the pressure-sensitive adhesive sheet. About. Furthermore, even if it is thin, it has processability (particularly punching processability) and unevenness followability, and further has excellent separator peelability, an electronic device member laminate having the above adhesive sheet, and an optical having the above adhesive sheet The present invention relates to a member laminate.

  In recent years, mobile devices such as mobile phones, digital cameras, smartphones, and PDAs (Personal Digital Assistants) have been downsized. For this reason, various electronic components to be mounted are also reduced in size and thickness. For example, mobile phones and smartphones, which are representative devices as mobile devices, tend to be laminated with each major component. Usually, the display part of a mobile phone or a smart phone is mainly composed of an LCD module and a backlight unit, and various sheet-like parts are laminated to develop devices such as light emission, reflection, light shielding, and light guide. Therefore, an adhesive tape or sheet (sometimes simply referred to as “adhesive tape” or “adhesive sheet”) for use in assembling (joining) these components has been devised. For example, a thin double-sided adhesive tape or sheet having strength is known (see Patent Document 1).

JP 2005-105212 A

  In recent years, with the reduction in thickness and size of portable devices and the reduction in thickness of electronic components mounted on portable devices, further ultrathin pressure-sensitive adhesive sheets have been demanded as pressure-sensitive adhesive sheets used for assembling (joining) components.

  However, when the pressure-sensitive adhesive sheet is thinned, there is a concern that the processability (particularly punching processability) is deteriorated and the unevenness followability is deteriorated.

  Also, if the pressure-sensitive adhesive sheet is made thin, when the separator (release liner) is peeled off from the pressure-sensitive adhesive surface (the surface provided by the pressure-sensitive adhesive layer) in order to use the pressure-sensitive adhesive sheet, Phenomenon that does not peel off at the specified interface but is originally peeled off at the interface that must be adhered (attached) to the adhesive surface), remaining adhesive layer on the separator (peeling off), overlapping of adhesive layers, intention Problems such as movement of the adhesive layer that does not occur, wrinkles and kinking of the adhesive layer accompanying such movement, and damage to the adhesive sheet are likely to occur.

Therefore, the objective of this invention is providing the adhesive sheet provided with workability and uneven | corrugated followability, even if it is thin.
Furthermore, another object of the present invention is to provide a pressure-sensitive adhesive sheet that has workability and unevenness followability and is excellent in separator peelability even when it is thin.

As a result of intensive studies, the inventors of the present invention have a pressure-sensitive adhesive sheet having a base material and a pressure-sensitive adhesive layer. Even if the pressure-sensitive adhesive sheet is thin, it can have both processability and handleability (handling property) at the same time, and It has been found that when the thickness of the base material is made smaller than a specific thickness, the unevenness followability can be provided.
Furthermore, when the double-sided pressure-sensitive adhesive sheet has an acrylic pressure-sensitive adhesive layer on both sides of the substrate, both the workability and the handleability (handling property) can be provided at the same time even if the pressure-sensitive adhesive sheet is thin, and the substrate If the thickness of the separator is smaller than a specific thickness, it is possible to provide uneven followability, and in addition, the peeling force on the pressure-sensitive adhesive layer in the separator on the heavy release surface side and the peeling on the pressure-sensitive adhesive layer in the separator on the light release surface side. It has been found that when the difference from the force is a specific value or more, good separator peelability is easily obtained.
And the present invention was completed.

That is, the present invention has an adhesive layer on at least one side of a plastic substrate having a thickness of less than 2.0 μm,
The pressure-sensitive adhesive layer contains 50.0 to 99.8% by weight of the following (m1) with respect to the total amount of monomer components (100% by weight), and the following (m2) with respect to the total amount of monomer components (100% by weight) A pressure-sensitive adhesive sheet comprising 50% by weight or more of an acrylic polymer or a rubber-based polymer formed by a monomer mixture containing 0.01 to 20% by weight with respect to the total amount (100% by weight) of the pressure-sensitive adhesive layer is provided.
(M1): an alkyl (meth) acrylate monomer having an alkyl group having 1 to 10 carbon atoms represented by the following formula (1) CH ₂ = C (R ¹ ) COOR ² (1)
(In formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 10 carbon atoms.)
(M2): Polar group-containing monomer

The pressure-sensitive adhesive layer contains an acrylic polymer,
The monomer mixture preferably includes, as (m1), an alkyl (meth) acrylate monomer having an alkyl group having 1 to 5 carbon atoms and an alkyl (meth) acrylate monomer having an alkyl group having 6 to 10 carbon atoms. .

  The (m2) is one or more monomers selected from the group consisting of a vinyl monomer having a nitrogen atom in the skeleton, a vinyl monomer having a carboxyl group in the skeleton, and a vinyl monomer having a hydroxyl group in the skeleton. It is preferable.

  The vinyl monomer having a hydroxyl group in the skeleton is preferably hydroxyalkyl (meth) acrylate.

  The pressure-sensitive adhesive layer preferably contains a crosslinking agent in an amount of 0.001 to 10 parts by weight with respect to 100 parts by weight of the acrylic polymer or the rubber polymer.

  The pressure-sensitive adhesive layer preferably contains 5 to 60 parts by weight of a tackifier resin with respect to 100 parts by weight of the acrylic polymer or the rubber-based polymer.

  The pressure-sensitive adhesive sheet preferably has the pressure-sensitive adhesive layer on both sides of the plastic substrate.

Furthermore, the present invention has an acrylic pressure-sensitive adhesive layer on both sides of a plastic substrate having a thickness of less than 2.0 μm,
The separator A is provided so as to be in contact with one acrylic pressure-sensitive adhesive layer A, and the separator B is provided so as to be in contact with the other acrylic pressure-sensitive adhesive layer B.
The separator A is a separator having a release layer made of a silicone-based release agent on at least one side of a plastic substrate,
The separator B is a separator having a release layer made of a silicone release agent on at least one side of a plastic substrate,
A pressure-sensitive adhesive sheet is provided, wherein a difference between a peeling force of the separator B with respect to the acrylic pressure-sensitive adhesive layer B and a peeling force of the separator A with respect to the acrylic pressure-sensitive adhesive layer A is 0.01 N / 50 mm or more. To do.

  The pressure-sensitive adhesive sheet is preferably used for electrical or electronic equipment.

  The pressure-sensitive adhesive sheet is preferably for an optical member.

  Furthermore, this invention provides the electrical or electronic device member laminated body which has the laminated structure of the said adhesive sheet and an electrical or electronic device member.

  Furthermore, this invention provides the optical member laminated body which has a laminated structure of the said adhesive sheet and an optical member.

Since the pressure-sensitive adhesive sheet of the present invention has the above-described configuration, it has workability and unevenness followability even if it is thin.
Furthermore, even if the pressure-sensitive adhesive sheet of the present invention is thin, the pressure-sensitive adhesive sheet has processability and unevenness followability, and is excellent in separator peelability.

  The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer on at least one side of a plastic substrate having a thickness of less than 2.0 μm. In the present specification, the “plastic substrate having a thickness of less than 2.0 μm” may be referred to as “the substrate of the present invention”.

  The pressure-sensitive adhesive sheet of the present invention may be a pressure-sensitive adhesive sheet (single-sided pressure-sensitive adhesive sheet, single-sided pressure-sensitive adhesive sheet) having a pressure-sensitive adhesive layer (pressure-sensitive adhesive layer) on one side of the substrate of the present invention. It may be a pressure-sensitive adhesive sheet (double-sided pressure-sensitive adhesive sheet, double-sided pressure-sensitive adhesive sheet) having pressure-sensitive adhesive layers (pressure-sensitive adhesive layers) on both sides of the substrate of the invention. Especially, it is preferable that the adhesive sheet of this invention is a double-sided adhesive sheet from the point which bonds two members together, and the point used for fixation and temporary fixation of a member.

  In the pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive surface (the surface of the pressure-sensitive adhesive layer) may be protected by a separator (release liner) or the substrate of the present invention until use. For example, when the pressure-sensitive adhesive sheet of the present invention is a single-sided pressure-sensitive adhesive sheet, the pressure-sensitive adhesive surface may be protected by a separator, and the back surface of the base material (the base material pressure-sensitive adhesive layer is provided by winding). It may be protected by a surface on the opposite side to the surface on the side. On the other hand, in the case of a double-sided pressure-sensitive adhesive sheet, one pressure-sensitive adhesive surface may be protected by one separator, and the other pressure-sensitive adhesive surface may be protected by another separator. May be protected by one surface of one separator, and the other adhesive surface may be protected by the other surface of one separator. That is, when the pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet, it may be a double separator type in which two pressure-sensitive adhesive surfaces are protected by two separators, or two pressure-sensitive adhesive surfaces are protected by one separator. A single separator type may be used.

  When the pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet whose pressure-sensitive adhesive surface is protected by a separator, as an example of the embodiment, the acrylic pressure-sensitive adhesive layer is provided on both sides of the base material of the present invention, and one acrylic pressure-sensitive adhesive is used. A separator A is provided so as to be in contact with the agent layer A, a separator B is provided so as to be in contact with the other acrylic pressure-sensitive adhesive layer B, and the separator A is a release made of a silicone release agent on at least one side of the plastic substrate. A separator having a layer, wherein the separator B is a separator having a release layer made of a silicone release agent on at least one side of a plastic substrate, and the release force of the separator B to the acrylic pressure-sensitive adhesive layer B and the separator A pressure-sensitive adhesive sheet in which the difference between the peel strength of A and the acrylic pressure-sensitive adhesive layer A is 0.01 N / 50 mm or more is mentioned. It is. This pressure-sensitive adhesive sheet is a double separator type double-sided pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive surface provided by the acrylic pressure-sensitive adhesive layer A is protected by the separator A, and the pressure-sensitive adhesive surface provided by the acrylic pressure-sensitive adhesive layer B is protected by the separator B. .

Further, the pressure-sensitive adhesive sheet of the present invention contains 50.0 to 99.8% by weight of the following (m1) with respect to the total amount of monomer components (100% by weight), and the following (m2) to the total amount of monomer components (100% by weight). And having at least one pressure-sensitive adhesive layer containing 50% by weight or more of the acrylic polymer or rubber-based polymer formed by the monomer mixture containing 0.01 to 20% by weight with respect to the total amount (100% by weight) of the pressure-sensitive adhesive layer. Is preferred. In addition, a monomer mixture is a mixture comprised only from a monomer component.
(M1): an alkyl (meth) acrylate monomer having an alkyl group having 1 to 10 carbon atoms represented by the following formula (1) CH ₂ = C (R ¹ ) COOR ² (1)
(In formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 10 carbon atoms.)
(M2): Polar group-containing monomer Note that “(meth) acryl” means acryl and / or methacryl, and one or both of acryl and methacryl.
Further, “adhesive sheet” includes the meaning of “adhesive tape”. That is, the pressure-sensitive adhesive sheet of the present invention may be a pressure-sensitive adhesive tape having a tape-like form.

[Substrate of the Present Invention]
The base material of the present invention is a plastic base material (resin base material, polymer base material) having a thickness of less than 2.0 μm. In addition, the base material of this invention is a base material which consists of at least 1 layer, and may have a laminated structure of two or more layers. In addition, the base material of this invention is a part stuck to a to-be-adhered body with an adhesive layer, when using the adhesive sheet of this invention to a to-be-adhered body.

  Although it does not specifically limit as a material which comprises the base material of this invention, For example, polyesters, such as a polyethylene terephthalate, a polyethylene naphthalate, a polybutylene terephthalate, a polybutylene naphthalate; polyethylene, a polypropylene, an ethylene propylene copolymer, etc. Polyvinyl alcohol; Polyvinylidene chloride; Polyvinyl chloride; Vinyl chloride-vinyl acetate copolymer; Polyvinyl acetate; Polyamide; Polyimide; Cellulose; Fluorine-based resin; Polyether; Polyether amide; Examples thereof include sulfides; polystyrene resins such as polystyrene; polycarbonates; polyethersulfones. Of these, polyethylene terephthalate (PET) is preferred because of its good balance of strength, handleability (handling properties), cost, dimensional stability, and anchoring force. In addition, the said material can be used individually or in combination of 2 or more types.

  The thickness of the base material of the present invention is not particularly limited as long as it is less than 2.0 μm. The thickness of the base material of the present invention is such that, even in the pressure-sensitive adhesive sheet, it is thin, from the point of obtaining unevenness followability while obtaining processability (particularly punching workability) and handleability, from the point of obtaining thermal resistance, It is less than 2.0 μm, preferably 1.5 μm or less, more preferably 1.0 μm or less, even more preferably 0.8 μm or less, and particularly preferably 0.5 μm or less. In addition, the minimum of the base material of this invention should just be larger than 0 micrometer, Preferably it is 0.01 micrometer or more, More preferably, it is 0.1 micrometer or more, More preferably, it is 0.5 micrometer or more.

  The base material of the present invention may have deformability controlled by stretching treatment (uniaxial stretching or biaxial stretching) or the like. In addition, the surface of the base material of the present invention may be subjected to conventional surface treatments, for example, chromic acid treatment, ozone exposure, flame exposure, high piezoelectric impact exposure, ionization, in order to enhance the adhesion with the pressure-sensitive adhesive layer, if necessary. Oxidation treatment or the like by a chemical or physical method such as radiation treatment may be performed. Furthermore, when the base material of the present invention protects the adhesive surface on the back surface, a peeling treatment may be performed.

[Adhesive layer]
The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer is not particularly limited, but is preferably an acrylic pressure-sensitive adhesive layer or a rubber-based pressure-sensitive adhesive layer. The said acrylic adhesive layer contains 50 weight% or more of acrylic polymers as a base polymer with respect to the adhesive layer whole quantity (100 weight%). The rubber-based pressure-sensitive adhesive layer contains 50% by weight or more of a rubber-based polymer as a base polymer with respect to the total amount (100% by weight) of the pressure-sensitive adhesive layer.

  The pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition (pressure-sensitive adhesive composition). The pressure-sensitive adhesive composition includes the meaning of the composition forming the pressure-sensitive adhesive. In this specification, the pressure-sensitive adhesive composition that forms the acrylic pressure-sensitive adhesive layer may be referred to as “acrylic pressure-sensitive adhesive composition”, and the pressure-sensitive adhesive composition that forms the rubber-based pressure-sensitive adhesive layer may be referred to as “rubber-based pressure-sensitive adhesive”. It may be referred to as a “composition”.

  The pressure-sensitive adhesive composition may be a pressure-sensitive adhesive composition having any form, for example, an emulsion type, a solvent type (solution type), an active energy ray curable type, a hot melt type (hot melt type). ) And the like. Among them, the solvent type is preferable from the viewpoint of productivity.

  Preferred examples of the solvent-type pressure-sensitive adhesive composition include a pressure-sensitive adhesive composition containing a base polymer (rubber polymer or acrylic polymer) as an essential component. Moreover, as said active energy ray hardening-type adhesive composition, the adhesive composition which contains the mixture (monomer mixture) of the monomer component which comprises a base polymer (rubber polymer or acrylic polymer), or its partial polymer as an essential component. A thing is mentioned preferably. The “partially polymerized product” means a composition in which one or more components among the monomer components contained in the monomer mixture are partially polymerized. In addition, the “monomer mixture” includes a case where there is only one monomer component.

(Rubber adhesive layer)
As described above, the pressure-sensitive adhesive sheet of the present invention preferably has a rubber-based pressure-sensitive adhesive layer as the pressure-sensitive adhesive layer. The rubber-based pressure-sensitive adhesive layer contains a rubber-based polymer as a base polymer. The ratio of the rubber-based polymer in the rubber-based pressure-sensitive adhesive layer is not particularly limited as long as it is 50% by weight or more, but is preferably 60% by weight or more, more preferably 70% by weight or more from the viewpoint of adhesion reliability. It is.

  Examples of the rubber polymer include natural rubber, polybutadiene, polyisoprene, polyisobutylene, butyl rubber, chloroprene rubber, silicone rubber, acrylonitrile-butadiene rubber, and ethylene-propylene terpolymer. In addition, a rubber-type polymer can be used individually or in combination of 2 or more types.

  Furthermore, as said rubber-type polymer, a styrene-type block copolymer is mentioned preferably. The styrenic block copolymer means a polymer having at least one styrene block. The styrene block refers to a segment having styrene as a main monomer. A segment consisting essentially of styrene is a typical example of a styrene block as used herein.

  Examples of the styrenic block copolymer include a styrene isoprene block copolymer and a styrene butadiene block copolymer. The styrene isoprene block copolymer refers to a polymer having at least one styrene block and at least one isoprene block (a segment having isoprene as a main monomer). Examples of the styrene isoprene block copolymer include a triblock structure copolymer having a styrene block (hard segment) at both ends of the isoprene block (soft segment) (triblock body, styrene-isoprene-styrene block copolymer). (SIS block copolymer)); a copolymer having a diblock structure composed of one isoprene block and one styrene block (diblock body such as styrene-isoprene rubber). Examples of the styrene butadiene block copolymer include polymers having at least one styrene block and at least one butadiene block (a segment containing butadiene as a main monomer) (for example, styrene-butadiene rubber). . Other examples of the styrene block copolymer include styrene-butadiene-styrene block copolymer (SBS block copolymer), styrene-ethylene-butylene-styrene block copolymer (SEBS block copolymer). ) And the like.

  Furthermore, as the rubber-based polymer, a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound is also preferable. The “block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound” is a segment having a monovinyl-substituted aromatic compound as a main monomer (a copolymer component exceeding 50% by weight) (hereinafter referred to as “A And a polymer having at least one segment having a conjugated diene compound as a main monomer (hereinafter sometimes referred to as “B segment”). Generally, the glass transition temperature of the A segment is higher than the glass transition temperature of the B segment. A typical structure of the above-mentioned “block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound” is a co-polymerization of a triblock structure having A segments (hard segments) at both ends of the B segment (soft segments). Examples thereof include a blend (A-B-A structure triblock), a diblock copolymer (A-B structure diblock) composed of one A segment and one B segment.

  The monovinyl substituted aromatic compound refers to a compound in which one functional group having a vinyl group is bonded to an aromatic ring. A benzene ring is mentioned as said aromatic ring. The benzene ring may be a benzene ring substituted with a functional group having no vinyl group (for example, an alkyl group). Examples of the monovinyl substituted aromatic compound include styrene, α-methylstyrene, vinyl toluene, vinyl xylene and the like. Specific examples of the conjugated diene compound include 1,3-butadiene and isoprene.

  Among these, the rubber-based polymer is preferably the styrene-based block copolymer or the block copolymer of the monovinyl-substituted aromatic compound and the conjugated diene compound from the viewpoint of obtaining resistance to repulsive force and holding power.

  In the styrenic block copolymer or the block copolymer of the monovinyl-substituted aromatic compound and the conjugated diene compound, the styrene content is not particularly limited, but from the point of obtaining resistance to repulsive force and holding power, 10 It is preferable that it is -35 weight%, More preferably, it is 15-24 weight%, More preferably, it is 16-23 weight%.

  The styrene content is the mass ratio (weight ratio) of the styrene component to the total mass (total weight) of the styrene block copolymer or the block copolymer of the monovinyl-substituted aromatic compound and the conjugated diene compound. Say. The styrene content can be measured by NMR (nuclear magnetic resonance spectroscopy).

  The styrenic block copolymer and the “block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound” are in the form of a diblock body, a triblock body, a radial body, a mixture thereof, or the like. However, it is preferable to include a diblock body from the viewpoint of obtaining resistance to repulsive force and holding power. In the styrenic block copolymer and the “block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound”, the diblock ratio is not particularly limited, but is preferably 30 to 80% by weight, More preferably, it is 40-80 weight%, More preferably, it is 50-80 weight%, Most preferably, it is 50-70 weight%.

  The diblock body ratio is the mass ratio (weight) of the diblock body to the total mass (overall weight) of the styrene block copolymer or the “block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound”. Rate). A diblock body ratio can be calculated | required by comparing the peak area by a high performance liquid chromatography. For example, the total amount is dissolved in tetrahydrofuran (THF), and GS5000H and G4000H liquid chromatograph columns manufactured by Tosoh Corporation are connected in two stages, for a total of four stages, and THF is used as the mobile phase at a temperature of 40 ° C. , High performance liquid chromatography is performed under conditions of a flow rate of 1 ml / min. The peak area corresponding to the diblock body and the area of all peaks can be obtained from the obtained chart, and the percentage of the peak area of the diblock body relative to the area of all peaks can be calculated.

(Acrylic adhesive layer)
As described above, the pressure-sensitive adhesive sheet of the present invention preferably has an acrylic pressure-sensitive adhesive layer as the pressure-sensitive adhesive layer. The acrylic pressure-sensitive adhesive layer contains an acrylic polymer as a base polymer. The proportion of the acrylic polymer in the acrylic pressure-sensitive adhesive layer is not particularly limited as long as it is 50% by weight or more, but is preferably 60% by weight or more, more preferably 70% by weight or more from the viewpoint of adhesion reliability. It is.

  It does not specifically limit as said acrylic polymer, For example, the well-known acrylic polymer used for an acrylic adhesive is mentioned. Furthermore, as said acrylic polymer, 50.0-99.8 weight% is included with respect to monomer component whole quantity (100 weight%) as (m1), (m2) with respect to monomer component whole quantity (100 weight%). An acrylic polymer formed by a monomer mixture containing 0.01 to 20% by weight is preferred. In this specification, “(m1) is contained in an amount of 50.0 to 99.8% by weight based on the total amount of the monomer components (100% by weight), and (m2) is 0% based on the total amount of the monomer components (100% by weight). The “acrylic polymer formed by the monomer mixture containing 0.01 to 20% by weight” may be referred to as “acrylic polymer A”.

  The acrylic polymer A contains at least (m1) and (m2) as monomer components constituting the polymer.

  (M1) is an alkyl (meth) acrylate monomer having an alkyl group having 1 to 10 carbon atoms. It is preferable that the said C1-C10 alkyl group is a linear or branched alkyl group. In addition, (m1) can be used individually or in combination of 2 or more types.

  Examples of (m1) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylic acid. Isobutyl, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, (meta Preferred examples include octyl acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, and dodecyl (meth) acrylate.

  The ratio of (m1) to the total amount of monomer components (100% by weight) of the monomer mixture forming the acrylic polymer A is 50.0 to 99.8% by weight from the viewpoint of obtaining durability and adhesion reliability. Preferably 60.0-99.8 wt%, more preferably 70.0-99.8 wt%, even more preferably 80.0-99.8 wt%, particularly preferably 90.0-99.8 wt%. %. That is, the ratio of (m1) to the total amount (100% by weight) of monomer components constituting the acrylic polymer is 50.0 to 99.8% by weight, preferably 60.0 to 99.8% by weight. Preferably it is 70.0-99.8 weight%, More preferably, it is 80.0-99.8 weight%, Especially preferably, it is 90.0-99.8 weight%.

  Among them, (m1) is an alkyl (meth) acrylate monomer having an alkyl group having 1 to 5 carbon atoms from the viewpoint of sufficiently obtaining tack and adhesion reliability even when the acrylic pressure-sensitive adhesive layer is thin, and An alkyl (meth) acrylate monomer having an alkyl group having 6 to 10 carbon atoms is preferable. That is, (m1) is preferably used in combination of an alkyl (meth) acrylate monomer having an alkyl group having 1 to 5 carbon atoms and an alkyl (meth) acrylate monomer having an alkyl group having 6 to 10 carbon atoms. .

  That is, the acrylic pressure-sensitive adhesive layer contains the acrylic polymer A, and the monomer mixture forming the acrylic polymer A is an alkyl (meth) acrylate monomer having an alkyl group having 1 to 5 carbon atoms as (m1). And an alkyl (meth) acrylate monomer having an alkyl group having 6 to 10 carbon atoms.

  In particular, (m1) is preferably n-butyl acrylate and 2-ethylhexyl acrylate. That is, the monomer mixture forming the acrylic polymer preferably contains n-butyl acrylate and 2-ethylhexyl acrylate as (m1).

  When (m1) is an alkyl (meth) acrylate monomer having an alkyl group having 1 to 5 carbon atoms and an alkyl (meth) acrylate monomer having an alkyl group having 6 to 10 carbon atoms, as described above, carbon The ratio of the alkyl (meth) acrylate monomer having an alkyl group of 1 to 5 and the alkyl (meth) acrylate monomer having an alkyl group of 6 to 10 carbon atoms is 90:10 in the former: latter (weight basis). It is preferable that it is -10: 90, More preferably, it is 80: 20-20: 80.

  The monomer mixture forming the acrylic polymer A contains at least (m2). That is, the acrylic polymer A contains at least (m2) copolymerizable with (m1) as a constituent monomer component. In addition, (m2) can be used individually or in combination of 2 or more types.

  (M2) is a polar group-containing monomer, which is a monomer having a polar group and a carbon-carbon double bond (ethylenically unsaturated bond) in the skeleton, that is, in the structure of the monomer. (M2) is a vinyl monomer having a polar group. Since the acrylic polymer A contains (m2) as a constituent monomer component, it becomes easy to obtain an appropriate cohesive force. For this reason, even if the said acrylic adhesive layer is thin, it becomes easy to obtain adhesive reliability, workability, and step absorbability.

  (M2) is not particularly limited, but preferably includes a vinyl monomer having a nitrogen atom in the skeleton, a vinyl monomer having a carboxyl group in the skeleton, and a vinyl monomer having a hydroxyl group in the skeleton. In the present specification, the “vinyl monomer having a nitrogen atom in the skeleton” is sometimes referred to as “nitrogen atom-containing monomer”, and the “vinyl monomer having a carboxyl group in the skeleton” is referred to as “carboxyl group-containing monomer”. The “vinyl monomer having a hydroxyl group in the skeleton” may be referred to as a “hydroxyl group-containing monomer”. However, the hydroxyl group-containing monomer does not include a nitrogen atom-containing monomer. That is, in this specification, the monomer having a hydroxyl group and a nitrogen atom in the skeleton is included in the nitrogen atom-containing monomer.

  That is, (m2) is preferably one or more monomers selected from the group consisting of a nitrogen atom-containing monomer, a carboxyl group-containing monomer, and a hydroxyl group-containing monomer.

  Preferred examples of the nitrogen atom-containing monomer include N-vinyl cyclic amides and (meth) acrylamides. In addition, a nitrogen atom containing monomer can be used individually or in combination of 2 or more types.

（式（２）中、Ｒ³は２価の有機基を示す） As said N-vinyl cyclic amide, the N-vinyl cyclic amide represented by following formula (2) is mentioned, for example.

(In formula (2), R ³ represents a divalent organic group)

R ³ in the above formula (2) is a divalent organic group, preferably a divalent saturated hydrocarbon group or an unsaturated hydrocarbon group, more preferably a divalent saturated hydrocarbon group (for example, carbon number). 3-5 alkylene groups, etc.).

  Examples of the N-vinyl cyclic amide represented by the above formula (2) include N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, N-vinyl-3-morpholinone, and N-vinyl-2-caprolactam. N-vinyl-1,3-oxazin-2-one, N-vinyl-3,5-morpholinedione, and the like.

  Examples of the (meth) acrylamides include (meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide and the like. Examples of the N-alkyl (meth) acrylamide include N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, Nn-butyl (meth) acrylamide, N-octylacrylamide and the like. Furthermore, the N-alkyl (meth) acrylamide includes (meth) acrylamide having an amino group such as dimethylaminoethyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, and dimethylaminopropyl (meth) acrylamide. Examples of the N, N-dialkyl (meth) acrylamide include N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, and N, N-diisopropyl. (Meth) acrylamide, N, N-di (n-butyl) (meth) acrylamide, N, N-di (t-butyl) (meth) acrylamide and the like can be mentioned.

  The (meth) acrylamides include, for example, various N-hydroxyalkyl (meth) acrylamides. Examples of the N-hydroxyalkyl (meth) acrylamide include N-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N- (2-hydroxypropyl) (meth) acrylamide, N- (1-hydroxypropyl) (meth) acrylamide, N- (3-hydroxypropyl) (meth) acrylamide, N- (2-hydroxybutyl) (meth) acrylamide, N- (3-hydroxybutyl) (meth) acrylamide, N- (4-hydroxybutyl) (meth) acrylamide, N-methyl-N-2-hydroxyethyl (meth) acrylamide and the like can be mentioned.

  The (meth) acrylamides include, for example, various N-alkoxyalkyl (meth) acrylamides. Examples of the N-alkoxyalkyl (meth) acrylamide include N-methoxymethyl (meth) acrylamide and N-butoxymethyl (meth) acrylamide.

  Examples of the nitrogen atom-containing monomer other than the N-vinyl cyclic amide and the (meth) acrylamides include aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and dimethylamino (meth) acrylate. Amino group-containing monomers such as propyl and t-butylaminoethyl (meth) acrylate; Cyano group-containing monomers such as acrylonitrile and methacrylonitrile; (Meth) acryloylmorpholine, N-vinylpiperazine, N-vinylpyrrole and N-vinyl Imidazole, N-vinylpyrazine, N-vinylmorpholine, N-vinylpyrazole, vinylpyridine, vinylpyrimidine, vinyloxazole, vinylisoxazole, vinylthiazole, vinylisothiazole, vinylpyridazine, (meth) acryloyl Heterocyclic monomers such as pyrrolidone, (meth) acryloylpyrrolidine, (meth) acryloylpiperidine, N-methylvinylpyrrolidone; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide Itaconimide monomers such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexitaconimide, N-laurylitaconimide, N-cyclohexylitaconimide, N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyoctamethylene Imide group-containing monomers such as succinimide monomers such Kushin'imido; and 2- (meth) acryloyl isocyanate group-containing monomers such as methacryloyloxyethyl isocyanate.

  Among these, as the nitrogen atom-containing monomer, N-vinyl cyclic amides and (meth) acrylamides represented by the above formula (2) are preferable, and more preferably N-vinyl-2-pyrrolidone and N-vinyl-2- Caprolactam, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, and more preferably N-vinyl-2-pyrrolidone.

  Examples of the carboxyl group-containing monomer include (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. Furthermore, an acid anhydride group-containing monomer such as maleic anhydride is also included. In addition, a carboxyl group-containing monomer can be used individually or in combination of 2 or more types.

  Among these, the carboxyl group-containing monomer is preferably (meth) acrylic acid, more preferably acrylic acid, from the viewpoints of adhesive strength and cohesive strength.

  Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth) acrylate, vinyl alcohol, allyl alcohol, and the like. Examples of the hydroxyalkyl (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxy (meth) acrylate. Examples include hexyl, hydroxyoctyl (meth) acrylate, hydroxydecyl (meth) acrylate, hydroxylauryl (meth) acrylate, (meth) acrylic acid (4-hydroxymethylcyclohexyl), and the like. In addition, a hydroxyl-containing monomer can be used individually or in combination of 2 or more types.

  Among these, the hydroxyl group-containing monomer is preferably a hydroxyalkyl (meth) acrylate, more preferably 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, 6-hydroxyhexyl acrylate, from the viewpoint of adhesive strength and cohesive strength. Even more preferred are 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate.

  Furthermore, examples of the polar group-containing monomer other than the nitrogen atom-containing monomer, the carboxyl group-containing monomer, and the hydroxyl group-containing monomer include (meth) acrylic acid alkoxyalkyl ester, epoxy group-containing monomer, sulfonic acid group-containing monomer, phosphorus Examples include acid group-containing monomers, vinyl esters, vinyl ethers, and vinyl chloride. As said (meth) acrylic-acid alkoxyalkyl ester, (meth) acrylic-acid 2-methoxyethyl, (meth) acrylic-acid 2-ethoxyethyl, (meth) acrylic-acid methoxytriethylene glycol, (meth) acrylic acid 3 -Methoxypropyl, (meth) acrylic acid 3-ethoxypropyl, (meth) acrylic acid 4-methoxybutyl, (meth) acrylic acid 4-ethoxybutyl and the like. Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate. Examples of the sulfonic acid group-containing monomer include sodium vinyl sulfonate. Examples of the vinyl esters include vinyl acetate and vinyl propionate. Examples of the vinyl ethers include vinyl alkyl ethers. In addition, these polar group containing monomers can be used individually or in combination of 2 or more types.

  In particular, (m2) is preferably two or more monomers selected from the group consisting of a nitrogen atom-containing monomer, a carboxyl group-containing monomer, and a hydroxyl group-containing monomer from the viewpoint of adhesive strength and cohesive strength. That is, (m2) is a combination of a nitrogen atom-containing monomer and a carboxyl group-containing monomer, a combination of a nitrogen atom-containing monomer and a hydroxyl group-containing monomer, or a carboxyl group-containing monomer and a hydroxyl group-containing monomer. It is preferably used in combination, or a nitrogen atom-containing monomer, a carboxyl group-containing monomer, and a hydroxyl group-containing monomer are used in combination. In particular, (m2) is preferably used in combination of a carboxyl group-containing monomer and a hydroxyl group-containing monomer.

  That is, the acrylic pressure-sensitive adhesive layer contains the acrylic polymer A, and the monomer mixture forming the acrylic polymer A is a group consisting of a nitrogen atom-containing monomer, a carboxyl group-containing monomer, and a hydroxyl group-containing monomer as (m2). It is preferable that two or more monomers (particularly, a carboxyl group-containing monomer and a hydroxyl group-containing monomer) are selected.

  Furthermore, the acrylic polymer A may contain a polyfunctional monomer (polyfunctional monomer) as a constituent monomer component, that is, as a monomer component copolymerizable with (m1) or (m2). That is, the monomer mixture that forms the acrylic polymer may contain a polyfunctional monomer. In addition, a polyfunctional monomer can be used individually or in combination of 2 or more types.

  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, 1,6-hexanediol diacrylate and dipentaerythritol hexa (meth) acrylate are preferable as the polyfunctional monomer. In addition, content of the said polyfunctional monomer is suitably selected in the range which does not impair the effect of this invention.

  Furthermore, the acrylic polymer A may contain the following other monomers as constituent monomer components, that is, as monomer components copolymerizable with (m1) and (m2). That is, the monomer mixture forming the acrylic polymer A may contain the following other monomers. Examples of the other monomer include (meth) acrylic acid ester having an alicyclic hydrocarbon group, (meth) acrylic acid ester having an aromatic hydrocarbon group, alkyl having 11 to 20 carbon atoms ( And (meth) acrylate monomers. Examples of the (meth) acrylic acid ester having an alicyclic hydrocarbon group include cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, and isobornyl (meth) acrylate. Examples of the (meth) acrylic acid ester having an aromatic hydrocarbon group include phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, and benzyl (meth) acrylate. Examples of the alkyl (meth) acrylate monomer having an alkyl group having 11 to 20 carbon atoms include, for example, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, Tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate Can be mentioned.

  The content of the other monomers is not particularly limited, but is appropriately determined within a range that does not adversely affect the properties of the pressure-sensitive adhesive sheet of the present invention. In addition, the said other monomer can be used individually or in combination of 2 or more types.

  The acrylic polymer A is formed of a monomer mixture containing at least (m1) and (m2). The acrylic polymer A is obtained by polymerizing the monomer components. Examples of the polymerization method include a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a polymerization method (thermal polymerization method, active energy ray polymerization method) by heat or active energy ray irradiation. Among them, from the viewpoint of balance of adhesion and ease of polymerization, a polymerization method by active energy ray irradiation (active energy ray polymerization method) and a solution polymerization method are preferable, and a solution polymerization method is more preferable.

  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 reaction of the monomer component.

  In the above solution polymerization, various common solvents can be used. Examples of such solvents include esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; cyclohexane and methyl Examples thereof include alicyclic hydrocarbons such as cyclohexane; organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. In addition, a solvent can be used individually or in combination of 2 or more types.

  In the polymerization, a polymerization initiator such as a photopolymerization initiator (photoinitiator) or a thermal polymerization initiator may be used depending on the type of polymerization reaction. In addition, a 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, 0.01-1 weight part is preferable with respect to 100 weight part of monomer components whole quantity contained in the acrylic monomer mixture which forms the said acrylic polymer A, More preferably, it is 0.05-0.5 weight part.

  Examples of the polymerization initiator used in the solution polymerization include azo polymerization initiators, peroxide polymerization initiators (eg, dibenzoyl peroxide, tert-butyl permaleate), redox polymerization initiators, and the like. Is mentioned. Of these, the azo polymerization initiators disclosed in JP-A No. 2002-69411 are preferable. Examples of the azo polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis (2-methylpropionic acid) dimethyl, Examples include 4,4′-azobis-4-cyanovaleric acid.

  Although the usage-amount of the said azo polymerization initiator is not specifically limited, It is 0.05-0.5 weight part with respect to 100 weight part of monomer components whole quantity contained in the acrylic monomer mixture which forms the said acrylic polymer A. Is more preferable, and 0.1 to 0.3 part by weight is more preferable.

  In the above description, the acrylic polymer A has been mainly described. However, acrylic polymers other than the acrylic polymer A can be similarly produced.

  The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention may contain an additive. The pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition (for example, an acrylic pressure-sensitive adhesive composition or a rubber-based pressure-sensitive adhesive composition), and such a pressure-sensitive adhesive composition contains an additive. It may be. The additive may be contained in a form bonded to an acrylic polymer or a rubber polymer in the pressure-sensitive adhesive layer. For example, the below-mentioned crosslinking agent may be contained in a form in which it is bonded to an acrylic polymer or rubber polymer in the pressure-sensitive adhesive layer. In addition, an additive is used individually or in combination of 2 or more types.

  As said additive, a crosslinking agent is mentioned preferably. According to the cross-linking agent, the base polymer (for example, the rubber polymer or the acrylic polymer) of the pressure-sensitive adhesive layer can be cross-linked to improve adhesion and cohesion. Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, urea crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, and metal salt crosslinking agents. Examples thereof include a crosslinking agent, a carbodiimide crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, and an amine crosslinking agent. Of these, isocyanate crosslinking agents and epoxy crosslinking agents are preferred. In addition, a crosslinking agent is 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 And aromatic polyisocyanates such as xylylene diisocyanate. Furthermore, trimethylolpropane / tolylene diisocyanate adduct [manufactured by Nippon Polyurethane Industry Co., Ltd., trade name “Coronate L”], trimethylolpropane / hexamethylene diisocyanate adduct [manufactured by Japan Polyurethane Industry Co., Ltd., trade name “Coronate HL”] ].

  Examples of the epoxy-based 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, trime 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 crosslinking agent in the pressure-sensitive adhesive layer (for example, the rubber-based pressure-sensitive adhesive layer, the acrylic pressure-sensitive adhesive layer, etc.) of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, but from the viewpoint of adhesiveness and cohesive force, The amount is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, and still more preferably 0.01 to 3 parts by weight with respect to 100 parts by weight of the acrylic polymer or rubber polymer. .

  Furthermore, as said additive, tackifying resin (tackifier) is mentioned preferably. According to the tackifier resin (tackifier), the adhesive properties and adhesion reliability of the adhesive layer can be further improved. Examples of the tackifier resin include terpene tackifier resins, phenol tackifier resins, rosin tackifier resins, and petroleum tackifier resins. In addition, tackifying resin is used individually or in combination of 2 or more types.

  Examples of the terpene-based tackifier resins include terpene resins such as α-pinene polymers, β-pinene polymers, dipentene polymers, and modified terpene resins (phenol-modified, aromatic-modified, hydrogenated). Modified terpene resin (modified, hydrocarbon modified, etc.) (for example, terpene phenol resin, styrene modified terpene resin, aromatic modified terpene resin, hydrogenated terpene resin, etc.).

  Examples of the phenolic tackifying resin include condensates (for example, alkylphenolic resins, xylenes) of various phenols (for example, phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcin, etc.) and formaldehyde. Formaldehyde resins), resols obtained by addition reaction of the above phenols with formaldehyde with an alkali catalyst, novolaks obtained by condensation reaction of the above phenols with formaldehyde with an acid catalyst, and rosins (unmodified rosin, Examples thereof include rosin-modified phenolic resins obtained by adding phenol to an acid catalyst and then thermally polymerizing them.

  Examples of the rosin-based tackifying resin include unmodified rosin (raw rosin) such as gum rosin, wood rosin and tall oil rosin, and modified rosin modified by hydrogenation, disproportionation, polymerization and the like of these unmodified rosins. In addition to hydrogenated rosin, disproportionated rosin, polymerized rosin and other chemically modified rosins, various rosin derivatives and the like can be mentioned. Examples of the rosin derivative include a rosin ester compound obtained by esterifying an unmodified rosin with an alcohol, and a modified rosin obtained by esterifying a modified rosin such as a hydrogenated rosin, a disproportionated rosin, or a polymerized rosin with an alcohol. Ester compounds such as rosin esters; Unmodified rosin and modified rosins (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.) modified with unsaturated fatty acids; Unsaturated fatty acid modified rosins; Rosin esters with unsaturated fatty acids Unmodified rosin, modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.), unsaturated fatty acid modified rosins and unsaturated fatty acid modified rosin esters Reduced rosin alcohols; unmodified rosin, modified rosin and various rosin derivatives Rosins and the like (in particular, rosin esters) and the like metal salts of.

  Examples of the petroleum-based tackifier resins include aromatic petroleum resins, aliphatic petroleum resins, alicyclic petroleum resins (aliphatic cyclic petroleum resins), aliphatic / aromatic petroleum resins, aliphatic / aliphatic resins. Examples include cyclic petroleum resins, hydrogenated petroleum resins, coumarone resins, coumarone indene resins, and the like. Specifically, as the aromatic petroleum resin, for example, a vinyl group-containing aromatic hydrocarbon having 8 to 10 carbon atoms (styrene, o-vinyltoluene, m-vinyltoluene, p-vinyltoluene, α-methyl styrene, β-methyl styrene, indene, methyl indene, etc.) are used alone or in combination of two or more. Further, the aromatic petroleum resin is preferably an aromatic petroleum resin (so-called “C9 petroleum resin”) obtained from a fraction such as vinyltoluene or indene (so-called “C9 petroleum fraction”). Examples of the aliphatic petroleum resin include olefins having 4 to 5 carbon atoms and dienes [olefins such as butene-1, isobutylene and pentene-1; dienes such as butadiene, piperylene (1,3-pentadiene) and isoprene, etc. ] Is a polymer in which only one type or two or more types are used. Further, as the aliphatic petroleum resin, an aliphatic petroleum resin (so-called “C4 type”) obtained from a fraction such as butadiene, piperylene or isoprene (so-called “C4 petroleum fraction”, “C5 petroleum fraction”, etc.). “Petroleum resin”, “C5 petroleum resin” and the like are preferred. Examples of the alicyclic petroleum resin include alicyclic carbonization obtained by polymerizing an aliphatic petroleum resin (so-called “C4 petroleum resin” or “C5 petroleum resin”) after cyclization and dimerization. Hydrogen-based resins, cyclic diene compounds (cyclopentadiene, dicyclopentadiene, ethylidene norbornene, dipentene, ethylidenebicycloheptene, vinylcycloheptene, tetrahydroindene, vinylcyclohexene, limonene, etc.) polymers or hydrogenated products thereof, Examples thereof include aromatic hydrocarbon resins and alicyclic hydrocarbon resins obtained by hydrogenating the aromatic rings of the following aliphatic / aromatic petroleum resins. Examples of the aliphatic / aromatic petroleum resins include styrene-olefin copolymers. Furthermore, examples of the aliphatic / aromatic petroleum resins include so-called “C5 / C9 copolymer petroleum resins”.

  Furthermore, examples of the tackifying resin include commercial products such as those manufactured by Sumitomo Bakelite Co., Ltd., trade name “Sumilite Resin PR-12603”, Arakawa Chemical Industries, Ltd., trade name “Pencel D125”, and the like.

  Among these, as the tackifier resin, rosin tackifier resins are preferable, rosin esters are more preferable, and polymerized rosin ester systems (rosin esterified products and modified rosin esterified products) are more preferable.

  The content of the tackifying resin in the pressure-sensitive adhesive layer (for example, the rubber-based pressure-sensitive adhesive layer, the acrylic pressure-sensitive adhesive layer, etc.) of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, but the pressure-sensitive adhesive properties and adhesion of the pressure-sensitive adhesive layer are not particularly limited. From the viewpoint of improving the reliability, the amount is preferably 5 to 60 parts by weight, more preferably 10 to 50 parts by weight, and still more preferably 10 to 45 parts by weight with respect to 100 parts by weight of the acrylic polymer or rubber polymer. It is.

  Furthermore, as said additive, a silane coupling agent is mentioned preferably. When the silane coupling agent is contained, the adhesion reliability to glass (particularly, the adhesion reliability to glass in a high temperature and high humidity environment) is improved, which is preferable.

  The silane coupling agent is not particularly limited. For example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-aminopropyltri And methoxysilane. Among these, γ-glycidoxypropyltrimethoxysilane is preferable. Moreover, as a commercial item, brand name "KBM-403" (made by Shin-Etsu Chemical Co., Ltd.) is mentioned, for example. In addition, a silane coupling agent can be used individually or in combination of 2 or more types.

  Content of the silane coupling agent in the adhesive layer which the adhesive sheet of this invention has is suitably selected in the range which does not impair the effect of this invention.

  Further, the additives include crosslinking accelerators, anti-aging agents, fillers, colorants (such as pigments and dyes), ultraviolet absorbers, antioxidants, chain transfer agents, plasticizers, softeners, surfactants, Examples thereof include an antistatic agent. These additives may be contained in the range which does not impair the effect of this invention.

  The pressure-sensitive adhesive layer (for example, the rubber-based pressure-sensitive adhesive layer and the acrylic pressure-sensitive adhesive layer) may be formed of a pressure-sensitive adhesive composition (for example, a rubber-based pressure-sensitive adhesive composition, an acrylic pressure-sensitive adhesive composition, etc.). The pressure-sensitive adhesive composition is not particularly limited, but can be obtained by, for example, a known preparation method. For example, a solvent-type pressure-sensitive adhesive composition is mixed with a base polymer (the rubber-based polymer or the acrylic polymer), a solvent, and an additive that is added as necessary (for example, the cross-linking agent or the tackifier resin described above). It is produced by doing. In the case of an active energy ray-curable pressure-sensitive adhesive composition, for example, the active energy ray-curable acrylic pressure-sensitive adhesive composition is a monomer mixture or a partial polymer thereof, and additives that are added as necessary (for example, It is produced by mixing the above-mentioned crosslinking agent and tackifying resin.

  The pressure-sensitive adhesive composition preferably has a viscosity suitable for handling and coating. For example, the active energy ray-curable acrylic pressure-sensitive adhesive composition preferably contains a partially polymerized monomer mixture. Although the polymerization rate of the said partial polymer is not specifically limited, 5-20 weight% is preferable, More preferably, it is 5-15 weight%.

The polymerization rate of the partial polymer is obtained as follows.
A part of the partially polymerized product is sampled and used as a sample. The sample is precisely weighed and its weight is determined to be “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 partially polymerized product before drying” and “weight loss”, the polymerization rate (% by weight) of the partially polymerized monomer component 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

  Although the said adhesive layer is not specifically limited, For example, the said adhesive composition is apply | coated (coating) on suitable support bodies, such as a base material of this invention, and a peeling film, and it heat-drys as needed. And / or by curing. For example, when the acrylic pressure-sensitive adhesive layer is formed of an active energy ray-curable acrylic pressure-sensitive adhesive composition, the active energy ray-curable acrylic pressure-sensitive adhesive composition is applied (coated) on a support, It is formed by irradiating active energy rays. In addition to the active energy ray irradiation, heat drying may be performed as necessary.

  A known coating method may be used for the above application (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 pressure-sensitive adhesive layer is formed of the pressure-sensitive adhesive composition, a decompression means (for example, a vacuum box configured so that the gas inside thereof is sucked by an exhaust duct connected to a suction fan) You may use the coating apparatus which has. If a coating apparatus having such a decompression means is used, a thin pressure-sensitive adhesive layer having a uniform thickness can be obtained efficiently.

  In addition, according to said coating apparatus, thickness is uniform and thin, and a roll-shaped adhesive sheet (adhesive tape) can be obtained efficiently. For example, a double-sided pressure-sensitive adhesive tape having a total thickness of 1 to 30 μm can be obtained efficiently. Moreover, when obtaining such a double-sided adhesive tape, it is preferable that the tension | tensile_strength of the base material (base material sheet) in said coating apparatus shall be 1-15N.

  Although the gel fraction of the said adhesive layer is not specifically limited, For example, it can be set to 10 to 60 weight%, Preferably it is 10 to 50 weight%, More preferably, it is 10 to 40 weight%. By setting the gel fraction to 60% by weight or less, the cohesive force of the pressure-sensitive adhesive layer is reduced to some extent and the pressure-sensitive adhesive layer becomes soft, so that the pressure-sensitive adhesive layer easily follows the stepped portion, and step absorbability is obtained. It becomes easy. On the other hand, by setting the gel fraction to 10% by weight or more, it is possible to suppress the occurrence of the problem that the pressure-sensitive adhesive layer becomes too soft and the workability of the pressure-sensitive adhesive sheet is deteriorated. Under the environment, it is possible to improve the adhesion reliability by suppressing the occurrence of bubbles and floating. The gel fraction can be controlled by, for example, the type and content (use amount) of the polyfunctional monomer and / or the crosslinking agent.

The gel fraction (ratio of solvent insoluble matter) can be determined as ethyl acetate insoluble matter. Specifically, the pressure-sensitive adhesive layer is determined as a weight fraction (unit:% by weight) with respect to the sample before immersion of the insoluble matter after being immersed in ethyl acetate at room temperature (23 ° C.) for 7 days. More specifically, the gel fraction is a value calculated by the following “gel fraction measurement method”.
(Measurement method of gel fraction)
About 1 g of the pressure-sensitive adhesive layer is sampled and the weight thereof is measured, and the weight is defined as “weight of the pressure-sensitive adhesive layer before immersion”. Next, after the collected pressure-sensitive adhesive layer was immersed in 40 g of ethyl acetate for 7 days, all the components insoluble in ethyl acetate (insoluble portions) were recovered, and the recovered all insoluble portions were dried at 130 ° C. for 2 hours. After removing ethyl acetate, the weight is measured to obtain “dry weight of insoluble portion” (weight of the pressure-sensitive adhesive layer after immersion). Then, the obtained numerical value is substituted into the following formula to calculate.
Gel fraction (% by weight) = [(Dry weight of insoluble part) / (Weight of pressure-sensitive adhesive layer before immersion)] × 100

  The adhesive strength (180 ° peel adhesive strength, 180 ° peel adhesive strength) of the pressure-sensitive adhesive layer is not particularly limited, but is preferably 0.1 N / 20 mm or more. When the adhesive strength is 0.1 N / 20 mm or more, it can be preferably used for temporary fixing applications and fixing applications. In addition, the said adhesive force is measured on condition of peeling angle: 180 degrees and a tensile speed of 300 mm / min.

  Although the thickness of the said adhesive layer is not specifically limited, 0.1-30 micrometers is preferable, More preferably, it is 0.1-10 micrometers, More preferably, it is 0.25-3 micrometers.

  In particular, the pressure-sensitive adhesive layer can have an adhesive strength of 0.1 N / 20 mm or more even when it is as thin as 0.25 to 3 μm.

[Other adhesive layers]
The pressure-sensitive adhesive sheet of the present invention may have another pressure-sensitive adhesive layer (pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer (for example, the acrylic pressure-sensitive adhesive layer, the rubber-based pressure-sensitive adhesive layer, etc.)). Although it does not specifically limit as said other adhesive layer, For example, a urethane adhesive, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a polyester adhesive, a polyamide adhesive, an epoxy adhesive And a pressure-sensitive adhesive layer formed from a known or common pressure-sensitive adhesive such as a vinyl alkyl ether pressure-sensitive adhesive or a fluorine-based pressure-sensitive adhesive. In addition, the said adhesive can be used individually or in combination of 2 or more types.

[Other layers]
The pressure-sensitive adhesive sheet of the present invention has the effects of the present invention in addition to the base material of the present invention, the pressure-sensitive adhesive layer (for example, the acrylic pressure-sensitive adhesive layer, the rubber-based pressure-sensitive adhesive layer, etc.), and other pressure-sensitive adhesive layers. Other layers (for example, an intermediate layer, an undercoat layer, etc.) may be included as long as they are not damaged.

[Separator]
The pressure-sensitive adhesive layer surface (pressure-sensitive adhesive surface) of the pressure-sensitive adhesive sheet of the present invention may be protected by a separator (release liner) until use. When the pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet, each pressure-sensitive adhesive surface may be protected by two separators, respectively, or in a roll shape by one separator whose both surfaces are release surfaces. You may protect in the form wound. The separator is used as a protective material for the pressure-sensitive adhesive layer, and is peeled off when the pressure-sensitive adhesive sheet of the present invention is attached to an adherend. Note that the separator is not necessarily provided.

  Although it does not specifically limit as said separator, For example, the separator which has a peeling layer (peeling process layer) on the at least one surface of a separator base material, the low-adhesion separator which consists of a fluoropolymer, the low adhesion which consists of a nonpolar polymer Sex separators and the like. 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 separator having a release layer on at least one surface of the separator substrate.

  Although it does not specifically limit as said separator 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). ), An olefin resin having an α-olefin as a monomer component, such as an ethylene-propylene copolymer, an ethylene-vinyl acetate copolymer (EVA); a polyvinyl chloride (PVC); a vinyl acetate resin; a polycarbonate (PC); Examples include polyphenylene sulfide (PPS); amide resins such as polyamide (nylon) and wholly aromatic polyamide (aramid); polyimide resins; and polyether ether ketone (PEEK).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.

  Further, the release layer may be a single layer or may have a laminated structure in which two or more layers are laminated as long as the characteristics of the present invention are not impaired.

  Among them, an example of a preferable specific configuration of the separator includes a configuration in which a PET film is used as a separator substrate, and a release layer made of a silicone-based release treatment agent is provided on at least one surface of the separator substrate. .

  The said separator can be manufactured by a well-known and usual method. Further, the separator 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.

  The thickness of the separator is not particularly limited, but is preferably 12 to 200 μm, more preferably 25 to 100 μm, and still more preferably 25 to 75 μm, from the viewpoint of cost and handling properties of the pressure-sensitive adhesive sheet in bonding work. It is.

  Moreover, when the adhesive sheet of this invention is a double separator type double-sided adhesive sheet, a separator is provided in one adhesive surface and a separator is provided also in the other adhesive surface. In such a case, both separators are preferably separators in which only one surface is a release layer (particularly, a separator having a release layer made of a silicone-based release agent on one surface of a plastic substrate). . The separator is provided so that the release layer is in contact with the adhesive surface. Of the two surfaces of the separator, the surface opposite to the side in contact with the pressure-sensitive adhesive layer may be referred to as the “back surface” of the separator.

  Furthermore, when the pressure-sensitive adhesive sheet of the present invention is a double separator type double-sided pressure-sensitive adhesive sheet, it is preferable that a difference is provided between the two separator peeling forces. For example, when the pressure-sensitive adhesive sheet of the present invention is a double separator type double-sided pressure-sensitive adhesive sheet, one separator is used for the pressure-sensitive adhesive surface (also referred to as “one surface side”) that is used (attached) first, and the other It is preferable that the separator is used for an adhesive surface (also referred to as “two-surface side”) to be used (attached) later. Therefore, one separator is used as a “light release side” separator that can be peeled off with a smaller force (peeling force), and the other separator requires a larger force (peeling force) to peel from the adhesive layer. It is preferably used as a separator on the “heavy release side”. In the present specification, the light release separator may be referred to as a “light release separator”, and the heavy release surface side separator may be referred to as a “heavy release separator”.

  In addition, when the adhesive sheet of this invention is a single separator type double-sided adhesive sheet, a separator is provided in one adhesive surface, and the other adhesive surface of an adhesive body is also protected by this separator by winding this. . When the pressure-sensitive adhesive sheet of the present invention is a single separator type, it is preferable that both surfaces of the separator have a release layer (release treatment layer). Of the two release layers of the separator, the release layer that comes into contact with the pressure-sensitive adhesive surface by being wound may be particularly referred to as a “back release layer”. Usually, the back side peeling layer side of the separator is used for “one side” of the double-sided pressure-sensitive adhesive sheet.

  When the pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet, the pressure-sensitive adhesive on the one surface side (lightly peeled side) of the separator from the viewpoint of suppressing the occurrence of the tearing phenomenon and allowing the pressure-sensitive adhesive sheet to be used stably. The peel force (separator peel force) for the layers (for example, the acrylic pressure-sensitive adhesive layer, the rubber-based pressure-sensitive adhesive layer, etc.) is 0.01 to 0.15 N / 50 mm, and the two sides of the separator (heavy peel side) ) In the pressure-sensitive adhesive layer (for example, the above-mentioned acrylic pressure-sensitive adhesive layer, rubber-based pressure-sensitive adhesive layer, etc.) (separator peeling force) is 0.05 to 0.25 N / 50 mm. The separator peeling force is preferably larger than the separator peeling force on the light peeling surface side.

  In particular, when the pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet, the release force against the pressure-sensitive adhesive layer of the heavy release separator (separator) can be suppressed from suppressing the occurrence of the tearing phenomenon and allowing the pressure-sensitive adhesive sheet to be used stably. The difference between the peeling force) and the peeling force with respect to the pressure-sensitive adhesive layer of the light release separator (separator peeling force) is preferably 0.01 N / 50 mm or more, more preferably 0.02 N / 50 mm or more, still more preferably 0.8. 05 N / 50 mm or more, particularly preferably 0.06 N / 50 mm or more.

  In addition, the said separator peeling force means 180 degree peeling adhesive force of the separator with respect to an adhesive layer measured by a 180 degree peeling test. The tensile speed is 300 mm / min.

Factors for controlling the separator peeling force include the type of release treatment agent, the amount of release treatment agent applied, the thickness of the separator, and the like.
In addition, even when they are the same separator, the case where the peeling difference has arisen by the direct coating surface and the bonding surface is also included. Even in the case of a separator that has been subjected to the same peeling treatment, the separator peeling force may be different between a surface directly coated with an adhesive in a wet state and a surface bonded with a roll after drying. The reason is as follows. By directly applying to the separator in the wet state, the adhesive flows into the gaps between the fine irregularities on the separator surface, and the adhesion is improved. On the other hand, the dried pressure-sensitive adhesive cannot flow into such irregularities as much as the wet state, and the adhesion is not good. Thereby, even if it is the separator which performed the same peeling process, a peeling force difference arises. The factor for controlling the separator peeling force includes a peeling force difference generated for the above reason.

[Adhesive sheet of the present invention]
The pressure-sensitive adhesive sheet of the present invention has at least the substrate and pressure-sensitive adhesive layer of the present invention. The pressure-sensitive adhesive sheet of the present invention is preferably a double-sided pressure-sensitive adhesive sheet having a structure having pressure-sensitive adhesive layers on both sides of the substrate of the present invention. Furthermore, the pressure-sensitive adhesive sheet of the present invention has a structure having pressure-sensitive adhesive layers on both sides of the substrate of the present invention until use, and the double-separator type in which the pressure-sensitive adhesive surface is protected by a light release separator and a heavy release separator It is preferable that it is a double-sided adhesive sheet.

  As a specific aspect of the pressure-sensitive adhesive sheet of the present invention, for example, the acrylic pressure-sensitive adhesive layer containing the acrylic polymer A as a base polymer on at least one side of a plastic substrate having a thickness of less than 2.0 μm or the above-mentioned An adhesive sheet having an adhesive layer selected from rubber-based adhesive layers can be mentioned.

  Furthermore, when the pressure-sensitive adhesive sheet of the present invention is a double separator type double-sided pressure-sensitive adhesive sheet, as a preferred specific embodiment, a pressure-sensitive adhesive layer [for example, the above-mentioned acrylic on both sides of a plastic substrate having a thickness of less than 2.0 μm] System adhesive layer (especially the above acrylic adhesive layer containing the above acrylic polymer A as a base polymer), the above rubber adhesive layer, etc.], and a light release separator is provided so as to be in contact with one adhesive layer A heavy release separator is provided so as to be in contact with the other pressure-sensitive adhesive layer, and the light release separator is a separator having a release layer made of a silicone release agent on at least one side of a plastic substrate, and the heavy release separator is A separator having a release layer made of a silicone-based release agent on at least one side of a plastic substrate, the heavy release separator Examples include a pressure-sensitive adhesive sheet having a difference between a peeling force (separator peeling force) for the pressure-sensitive adhesive layer of the separator and a peeling force (peeling force) for the light release separator to the pressure-sensitive adhesive layer of 0.01 N / 50 mm or more.

  The thickness (total thickness) of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, but is preferably 1.0 μm or more and less than 30.0 μm, more preferably 1.0 μm or more and less than 10.0 μm, and still more preferably 1. It is 0 μm or more and 3.0 μm or less. The above thickness does not include the thickness of the separator.

  In particular, the pressure-sensitive adhesive sheet of the present invention has a thickness (total thickness) in the above range, and even when it is thin, it has the base material of the present invention, so that the workability (particularly punching workability), handling ( Handling), and also has an uneven tracking ability. In addition, it is because the thickness of the base material of this invention is less than 2.0 micrometers that is excellent in uneven | corrugated followable | trackability. Furthermore, even if it is thin, since it has the said adhesive layer (for example, the said acrylic adhesive layer, the said rubber adhesive layer, etc.), it has adhesive reliability.

  The pressure-sensitive adhesive sheet of the present invention is preferably used for electric or electronic devices, particularly for portable electric or electronic devices. Examples of the portable electronic device include mobile phones, PHS, smart phones, tablets (tablet computers), mobile computers (mobile PCs), personal digital assistants (PDAs), electronic notebooks, portable televisions, portable radios, and the like. Type broadcast receivers, portable game machines, portable audio players, portable DVD players, cameras such as digital cameras, camcorder type video cameras, and the like.

  The pressure-sensitive adhesive sheet of the present invention is preferably used, for example, for manufacturing electrical or electronic devices, and is preferably used for manufacturing portable electrical or electronic devices. Specifically, the pressure-sensitive adhesive sheet of the present invention is preferably used for pasting members and modules constituting a portable electronic device, fixing members and modules constituting a portable electronic device to a housing, and the like. More specifically, a cover glass or lens (especially a glass lens) and a touch panel or a touch sensor are bonded together, a cover glass or lens (especially a glass lens) is fixed to a case, a display panel is fixed to a case, Fixing input devices such as a sheet-like keyboard and touch panel to the case, bonding the protective panel of the information display unit to the case, bonding the cases together, bonding the case and the decorative sheet, portable electronics Examples include fixing and bonding various members and modules constituting the device. Note that in this specification, the display panel refers to a structure including at least a lens (particularly a glass lens) and a touch panel. In addition, the lens in the present specification is a concept including both a transparent body showing a light refraction action and a transparent body having no light refraction action. That is, the lens in the present specification includes a simple window panel having no refraction action. Furthermore, in this specification, a member or a module constituting an electric or electronic device may be referred to as an “electric or electronic device member”.

  As described above, the pressure-sensitive adhesive sheet of the present invention can be preferably used for fixing a screen display.

  Furthermore, the pressure-sensitive adhesive sheet of the present invention is preferably used for optical applications. That is, the pressure-sensitive adhesive sheet of the present invention may be a pressure-sensitive adhesive sheet for optical members (optical pressure-sensitive adhesive sheet). For example, the pressure-sensitive adhesive sheet of the present invention is preferably used for an application for bonding an optical member (for optical member bonding) or a manufacturing application for a product (optical product) using the optical member. Furthermore, the pressure-sensitive adhesive sheet of the present invention is preferably used for fixing various optical films shown below.

  The optical member is a member having optical properties (for example, polarization, light refraction, light scattering, light reflection, light transmission, light absorption, light diffraction, optical rotation, visibility, etc.). Say. Although it will not specifically limit if it is a member which has an optical characteristic as said optical member, For example, it is used for the member which comprises apparatuses (optical apparatus), such as a display apparatus (image display apparatus) and an input device, or these apparatuses. For example, a polarizing plate, a wavelength plate, a retardation plate, an optical compensation film, a brightness enhancement film, a light guide plate, a reflection film, an antireflection film, a transparent conductive film (for example, a plastic film having an ITO layer on the surface ( ITO films), design films, decorative films, surface protective plates, prisms, lenses, color filters, transparent substrates, and members in which these are laminated (collectively referred to as “functional films”) There are). 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".

  Examples of the display device include a liquid crystal display device, an organic EL (electroluminescence) display device, a PDP (plasma display panel), and electronic paper. Moreover, a touch panel etc. are mentioned as said input device.

  Although it does not specifically limit as said optical member, For example, members (for example, a sheet form, a film form, a plate-shaped member etc.) etc. which consist of glass, an acrylic resin, a polycarbonate, a polyethylene terephthalate, a cycloolefin polymer, a metal thin film etc., etc. Can be mentioned. As described above, the “optical member” in the present invention is a member (design film, decorative film, or surface protection) that plays a role of decoration or protection while maintaining the visibility of a display device or an input device as an adherend. Film etc.).

  Furthermore, the pressure-sensitive adhesive sheet of the present invention can be preferably used for fixing a heat radiating sheet, fixing a ferrite sheet, fixing a magnetic shield sheet, and the like.

  Furthermore, as an aspect of bonding of electrical or electronic equipment members by the pressure-sensitive adhesive sheet of the present invention, although not particularly limited, for example, (1) an aspect of bonding electrical or electronic equipment members to each other via the pressure-sensitive adhesive sheet of the present invention, (2) A mode in which an electric or electronic device member is bonded to a member other than an electric or electronic device member via the pressure-sensitive adhesive sheet of the present invention, (3) the pressure-sensitive adhesive sheet of the present invention containing an electric or electronic device member (for example, the following For example, the electrical or electronic device member laminate may be bonded to an electrical or electronic device member or a member other than the electrical or electronic device member.

  Further, the mode of bonding of the optical member by the pressure-sensitive adhesive sheet of the present invention is not particularly limited. For example, (1) a mode of bonding the optical members to each other via the pressure-sensitive adhesive sheet of the present invention, (2) of the present invention. A mode in which the optical member is bonded to a member other than the optical member via the pressure-sensitive adhesive sheet, (3) the pressure-sensitive adhesive sheet of the present invention (for example, the following optical member laminate) including the optical member is a member other than the optical member or the optical member The mode of pasting to the above is mentioned.

[Laminate of electrical or electronic equipment members]
The electric or electronic device member laminate of the present invention has a laminated structure of the pressure-sensitive adhesive sheet of the present invention and an electric or electronic device member. That is, the electrical or electronic equipment member laminate of the present invention includes the pressure-sensitive adhesive sheet of the present invention. In addition, when the pressure-sensitive adhesive sheet of the present invention which is a double-sided pressure-sensitive adhesive sheet is included, the electrical or electronic device member laminate of the present invention is a pressure-sensitive electrical or electronic device member provided with a pressure-sensitive adhesive surface on at least a part of the optical member surface. It is also a laminate (for example, an adhesive electric or electronic device member laminate in which an adhesive surface is provided on at least one side of a sheet-like electrical or electronic device member laminate).

  Since the electrical or electronic equipment member laminate of the present invention includes the pressure-sensitive adhesive sheet of the present invention, it has unevenness followability and adhesion reliability. For this reason, it can use preferably for uses, such as fixation of an electronic device member, and temporary fixation.

[Optical member laminate]
The optical member laminate of the present invention has a laminated structure of the pressure-sensitive adhesive sheet and the optical member of the present invention. That is, the optical member laminate of the present invention includes the pressure-sensitive adhesive sheet of the present invention. In addition, when the pressure-sensitive adhesive sheet of the present invention which is a double-sided pressure-sensitive adhesive sheet is included, the optical member laminate of the present invention has a pressure-sensitive adhesive optical member (for example, sheet-like optics) in which a pressure-sensitive adhesive surface is provided on at least a part of the optical member surface. It is also an adhesive optical member in which an adhesive surface is provided on at least one side of the member.

  Examples of the optical member laminate of the present invention include an optical member including the pressure-sensitive adhesive sheet of the present invention, a touch panel including the pressure-sensitive adhesive sheet of the present invention, an image display device including the pressure-sensitive adhesive sheet of the present invention, and a glass including the pressure-sensitive adhesive sheet of the present invention. Examples include lenses.

  Since the optical member laminate of the present invention includes the pressure-sensitive adhesive sheet of the present invention, the optical member laminate has irregularity following properties and adhesion reliability. For this reason, it can use preferably for uses, such as fixation of an optical member, and temporary fixation.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In the examples, unless otherwise indicated, parts by weight means a value converted to solid content.

(Preparation example 1 of acrylic polymer solution)
n-butyl acrylate (BA) 70 parts by weight, 2-ethylhexyl acrylate (2-EHA) 30 parts by weight, acrylic acid (AA) 3 parts by weight, 4-hydroxybutyl acrylate (4-HBA) 0.05 parts by weight, and 0.08 parts by weight of azobisisobutyronitrile (AIBN) as a polymerization initiator was added to a toluene solvent. Thereafter, solution polymerization was carried out at 68 ° C. for 8 hours to obtain an acrylic polymer solution. The weight average molecular weight of the acrylic polymer was 440,000.
The acrylic polymer solution thus obtained was referred to as “acrylic polymer solution (A)”.

(Preparation example 1 of acrylic pressure-sensitive adhesive composition)
Polymeric rosin pentaerythritol ester resin (trade name “Pencel D125”, manufactured by Arakawa Chemical Industry Co., Ltd., softening point: 125 ° C.) is added to acrylic polymer solution (A) to 30 parts by weight with respect to 100 parts by weight of acrylic polymer in the solution. In addition, an isocyanate-based crosslinking agent (trade name “Coronate L”, manufactured by Nippon Polyurethane Industry Co., Ltd.) is added to 2 parts by weight with respect to 100 parts by weight of the acrylic polymer in the solution. It was. In this way, an acrylic pressure-sensitive adhesive composition was prepared.
The acrylic pressure-sensitive adhesive composition thus obtained was referred to as “acrylic pressure-sensitive adhesive composition (A)”.

(Usage example 1 of base material)
A PET film having a thickness of 0.5 μm was used as the substrate. This base material was referred to as “base material (A)”.

(Usage example 2)
A PET film having a thickness of 5 μm was used as the substrate. This base material was referred to as “base material (B)”.

(Usage example 3)
A PET film having a thickness of 12 μm was used as the substrate. In addition, this base material was set to "base material (C)."

(Separator Production Example 1)
Add thermosetting addition type silicone (trade name “KS-847T”, manufactured by Shin-Etsu Chemical Co., Ltd.), platinum catalyst (trade name “PL-50T”, manufactured by Shin-Etsu Chemical Co., Ltd.), and add toluene. Thus, a silicone release treatment agent (solvent type silicone release treatment agent) having a solid content concentration of 1% by weight was obtained. This silicone release agent was applied to one surface of a PET film and cured by heat to obtain a separator (release liner) having a silicone release layer on one surface of the PET film.
The separator thus obtained was designated as “Separator (A)”. The separator (A) was used as a light release surface side (one surface side) separator.

(Separator Production Example 1)
Thermosetting addition type silicone (trade name “KS-3703”, manufactured by Shin-Etsu Chemical Co., Ltd.), release control agent (trade name “X-92-183”, manufactured by Shin-Etsu Chemical Co., Ltd.), platinum catalyst (product) The name “PL-50T” (manufactured by Shin-Etsu Chemical Co., Ltd.) was blended, and toluene was added to obtain a silicone release agent (solvent type silicone release agent) having a solid content concentration of 1% by weight. This silicone release agent was applied to one surface of a PET film and cured by heat to obtain a separator (release liner) having a silicone release layer on one surface of the PET film.
The separator thus obtained was designated as “Separator (B)”. The separator (B) was used as a separator on the heavy release surface side (2 surface side).

(Example 1)
Applying the acrylic pressure-sensitive adhesive composition (A) to the separator (A) so that the final thickness (thickness of the formed acrylic pressure-sensitive adhesive layer) is 0.8 μm to form a coating layer, This was put into an oven and heat-dried at 100 ° C. for 3 minutes to obtain a sheet 1 having an acrylic pressure-sensitive adhesive layer (thickness 0.8 μm).
Next, the acrylic pressure-sensitive adhesive composition (A) is applied to the separator (B) so that the final thickness (thickness of the formed acrylic pressure-sensitive adhesive layer) is 0.8 μm. After forming, this was put into an oven and heat-dried at 100 ° C. for 3 minutes to obtain a sheet 2 having an acrylic pressure-sensitive adhesive layer (thickness 0.8 μm).
And the sheet | seat 2 is bonded together on the one side of a base material (A), and the sheet | seat 1 is then bonded together on the other side of a base material (A), and both surfaces which have an adhesive layer on the both surfaces side of a base material An adhesive sheet was obtained.
In addition, this double-sided pressure-sensitive adhesive sheet has a separator (A) (one side) / acrylic pressure-sensitive adhesive layer (thickness 0.8 μm) / base material (A) (thickness 0.5 μm) / acrylic pressure-sensitive adhesive layer ( (Thickness 0.8 μm) / Separator (B) (2 side side).
Moreover, when apply | coating an acrylic adhesive composition to a separator, the coating device which has a pressure reduction means was used. In addition, according to this coating apparatus, it is preferable at the point which can apply | coat the thickness of an acrylic adhesive composition uniformly.

(Example 2)
Applying the acrylic pressure-sensitive adhesive composition (A) to the separator (A) so that the final thickness (thickness of the formed acrylic pressure-sensitive adhesive layer) is 1.2 μm to form a coating layer, In the same manner as in Example 1, a sheet 1 having an acrylic pressure-sensitive adhesive layer (thickness: 1.2 μm) was obtained.
Further, an application layer is formed by applying the acrylic pressure-sensitive adhesive composition (A) to the separator (B) so that the final thickness (thickness of the formed acrylic pressure-sensitive adhesive layer) is 1.2 μm. In the same manner as in Example 1, a sheet 2 having an acrylic pressure-sensitive adhesive layer (thickness: 1.2 μm) was obtained.
Then, in the same manner as in Example 1, the sheet 2 is bonded to one surface of the substrate (A), the sheet 1 is bonded to the other surface of the substrate (A), and the both surfaces of the substrate are adhered. A double-sided PSA sheet having an agent layer was obtained.
In addition, this double-sided pressure-sensitive adhesive sheet has a separator (A) (one side) / acrylic pressure-sensitive adhesive layer (thickness 1.2 μm) / base material (A) (thickness 0.5 μm) / acrylic pressure-sensitive adhesive layer ( It has a laminated structure of (thickness 1.2 μm) / separator (B) (two sides).

(Comparative Example 1)
The acrylic pressure-sensitive adhesive composition (A) was applied to the separator (B) so that the final thickness (thickness of the acrylic pressure-sensitive adhesive layer to be formed) was 3.0 μm to form a coating layer. Next, a separator (A) was provided on the coating layer to coat the coating layer. Next, the substrate-less double-sided pressure-sensitive adhesive sheet having an acrylic pressure-sensitive adhesive layer (thickness: 3.0 μm) was obtained by irradiating ultraviolet light having an illuminance of 5 mW / cm ² with a black light (manufactured by Toshiba Corporation).
In addition, this double-sided pressure-sensitive adhesive sheet has a laminated structure of separator (A) (one side) / acrylic pressure-sensitive adhesive layer (thickness: 3.0 μm) / separator (B) (two sides).

(Comparative Example 2)
Applying the acrylic pressure-sensitive adhesive composition (A) to the separator (A) so that the final thickness (the thickness of the acrylic pressure-sensitive adhesive layer to be formed) is 0.5 μm to form a coating layer, In the same manner as in Example 1, a sheet 1 having an acrylic pressure-sensitive adhesive layer (thickness 0.5 μm) was obtained.
Further, an application layer is formed by applying the acrylic pressure-sensitive adhesive composition (A) to the separator (B) so that the final thickness (thickness of the acrylic pressure-sensitive adhesive layer to be formed) is 0.5 μm. In the same manner as in Example 1, a sheet 2 having an acrylic pressure-sensitive adhesive layer (thickness: 0.5 μm) was obtained.
And like Example 1, the sheet | seat 1 is bonded together on one side of a base material (B), the sheet | seat 2 is bonded together on the other side of a base material (B), and it adheres to both surfaces of a base material. A double-sided PSA sheet having an agent layer was obtained.
In addition, this double-sided pressure-sensitive adhesive sheet has a separator (A) (one side) / acrylic pressure-sensitive adhesive layer (thickness 0.5 μm) / base material (B) (thickness 5 μm) / acrylic pressure-sensitive adhesive layer (thickness). 0.5 μm) / separator (B) (2 side side).

(Comparative Example 3)
Applying the acrylic pressure-sensitive adhesive composition (A) to the separator (A) so that the final thickness (thickness of the formed acrylic pressure-sensitive adhesive layer) is 1.5 μm to form a coating layer, In the same manner as in Example 1, a sheet 1 having an acrylic pressure-sensitive adhesive layer (thickness: 1.5 μm) was obtained.
Further, an application layer is formed by applying the acrylic pressure-sensitive adhesive composition (A) to the separator (B) so that the final thickness (thickness of the formed acrylic pressure-sensitive adhesive layer) is 1.5 μm. In the same manner as in Example 1, a sheet 2 having an acrylic pressure-sensitive adhesive layer (thickness: 1.5 μm) was obtained.
And like Example 1, the sheet | seat 1 is bonded together on the one surface of a base material (C), the sheet | seat 2 is bonded together on the other surface of a base material (C), and it adheres to both surfaces of a base material. A double-sided PSA sheet having an agent layer was obtained.
In addition, this double-sided pressure-sensitive adhesive sheet has a separator (A) (one surface side) / acrylic pressure-sensitive adhesive layer (thickness 1.5 μm) / base material (C) (thickness 12 μm) / acrylic pressure-sensitive adhesive layer (thickness). 1.5 μm) / separator (B) (2 side side).

(Measurement or evaluation)
The double-sided pressure-sensitive adhesive sheets of Examples and Comparative Examples were subjected to the following measurements or evaluations. The results are shown in Table 1.

(180 ° peeling adhesion strength (adhesive strength))
A sheet piece having a length of 100 mm and a width of 20 mm was cut out from the double-sided pressure-sensitive adhesive sheet. Next, the separator (A) was peeled from the sheet piece, and a PET film (trade name “Lumirror S-10”, thickness 25 μm) was attached (backed) to the exposed adhesive surface. And it was set as the test piece.
Next, the test piece was bonded to the test plate with the pressure-sensitive adhesive surface that was peeled off and exposed from the separator (B) of the test piece, and pressed under the conditions of a 2 kg roller and one reciprocation. Thereafter, the film was aged for 30 minutes in an atmosphere of 23 ° C. and 50% RH. After aging, using a tensile tester (device name “Autograph AG-IS”, manufactured by Shimadzu Corporation) under the conditions of 23 ° C., 50% RH, tensile speed 300 mm / min, peel angle 180 °, The test piece was peeled off from the test plate, peeled off 180 °, and the adhesive strength (N / 20 mm) was measured.
A stainless steel plate (SUS304BA plate) was used as the test plate. Note that the surface of the test plate is smooth.

(Unevenness tracking)
A PET film (trade name “Lumirror S-10”, thickness 25 μm) was attached (backed) to the adhesive surface exposed by peeling off the separator (A) of the double-sided adhesive sheet to obtain a test piece.
Next, the separator (B) of the test piece was peeled off, and the test piece was bonded to the surface having the step of the adherend with the exposed adhesive surface, and pressure-bonded under the conditions of a 2 kg roller and one reciprocating pressure. Thereafter, the film was aged for 30 minutes in an atmosphere of 23 ° C. and 50% RH. And the structure A was obtained.
And the test piece near the level | step difference in the structure A was observed visually, and the following reference | standard evaluated.
Evaluation criteria Good (◯): The pressure-sensitive adhesive sheet follows the level difference, and no floating is observed.
Bad (×): The pressure-sensitive adhesive sheet cannot follow the step, and floating is observed.
In addition, the adherend used for evaluation of uneven | corrugated followable | trackability is a sheet form, and has a level | step difference in one surface. The height of the step is 10 μm.

(Punching workability)
A double-sided adhesive sheet is punched from one side with a sealing blade (device name “D250”, manufactured by Iwasaki Tekko Co., Ltd.) at a rate of 100 shots / min. did.
The punched double-sided PSA sheet was observed and evaluated according to the following evaluation criteria.
Evaluation criteria: When the punched double-sided pressure-sensitive adhesive sheet is observed, wrinkles or warpage, damage, adhesive sticking out at the edge of the sticking sheet, or unintentional joining between double-sided pressure-sensitive adhesive sheets due to damage or sticking out It was evaluated as defective (x). On the other hand, it was evaluated as good (◯) when it was punched neatly and the above problem did not occur.

(Separator peeling force)
A sheet piece having a length of 100 mm and a width of 50 mm was cut out from the double-sided pressure-sensitive adhesive sheet to obtain a test piece. This test piece was used as a test piece for one side evaluation.
Moreover, the separator (A) was peeled off from the test piece for evaluation on one side, and a PET film (trade name “Lumirror S-10”, thickness 25 μm) was attached (backed) to the exposed adhesive surface. And it was set as the test piece for 2 surface side evaluation.
Using a tensile tester (device name “Autograph AG-IS”, manufactured by Shimadzu Corporation), under the conditions of 23 ° C., 50% RH, tensile speed 300 mm / min, peel angle 180 °, one side The separator (A) was peeled off from the test specimen for evaluation, peeled off by 180 °, and the adhesive strength (N / 50 mm) was measured. And this 180 degree peeling adhesive strength was made into the separator peeling force of the 1st surface side.
On the other hand, using a tensile tester (device name “Autograph AG-IS”, manufactured by Shimadzu Corporation), under an atmosphere of 23 ° C. and 50% RH, a tensile speed of 300 mm / min and a peeling angle of 180 °, 2 The separator (B) was peeled off from the test piece for surface side evaluation, peeled off by 180 °, and the adhesive strength (N / 50 mm) was measured. And this 180 degree peeling adhesive strength was made into the separator peeling force of the 2 side.

(Separator peelability)
During the separator peeling force test, the phenomenon of tearing, the adhesive layer remaining on the separator (peeling off), the overlapping of the adhesive layers, the unintended movement of the adhesive layer, and the adhesive layer accompanying such movement The case where wrinkles, kinks, damage to the adhesive sheet, etc. occurred was evaluated as defective (x). On the other hand, the case where it was separated neatly at the interface between the pressure-sensitive adhesive layer and the separator and the above problem did not occur was evaluated as good (◯).

  In addition, the separator peeling force of Comparative Example 1 could not be measured.

Claims (7)

Having an acrylic adhesive layer on both sides of a plastic substrate having a thickness of less than 2.0 μm,
The separator A is provided so as to be in contact with one acrylic pressure-sensitive adhesive layer A, and the separator B is provided so as to be in contact with the other acrylic pressure-sensitive adhesive layer B.
The separator A is a separator having a release layer made of a silicone-based release agent on at least one side of a plastic substrate,
The separator B is a separator having a release layer made of a silicone release agent on at least one side of a plastic substrate,
The total thickness of the pressure-sensitive adhesive sheet (excluding the thickness of the separator) is 1.0 μm or more and less than 10.0 μm,
The difference between the peeling force of the separator B with respect to the acrylic pressure-sensitive adhesive layer B and the peeling force of the separator A with respect to the acrylic pressure-sensitive adhesive layer A is 0.01 N / 50 mm or more,
The adhesive force (180 degree peeling adhesive force) of one or more acrylic adhesive layers selected from the group consisting of the acrylic adhesive layer A and the acrylic adhesive layer B is 0.1 N / 20 mm or more,
The acrylic pressure-sensitive adhesive layer contains an acrylic polymer as a base polymer, and the acrylic polymer has, as a monomer component constituting the polymer, an alkyl (meth) acrylate monomer (m1) having an alkyl group having 1 to 10 carbon atoms; At least a polar group-containing monomer (m2) copolymerizable therewith,
(M1) contains n-butyl acrylate and 2-ethylhexyl acrylate, and the ratio of the n-butyl acrylate and 2-ethylhexyl acrylate is the former: the latter (by weight): 80:20 to 10 : 90,
(M2) includes one or more monomers selected from the group consisting of nitrogen atom-containing monomers, carboxyl group-containing monomers, and hydroxyl group-containing monomers,
A pressure-sensitive adhesive sheet for electrical or electronic equipment.   The pressure-sensitive adhesive sheet according to claim 1, wherein the separator A has a peeling force with respect to the acrylic pressure-sensitive adhesive layer A of 0.01 to 0.15 N / 50 mm.   The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein a peeling force of the separator B with respect to the acrylic pressure-sensitive adhesive layer B is 0.05 to 0.25 N / 50 mm.   The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the thickness of one or more separators selected from the group consisting of the separator A and the separator B is 12 to 200 µm. The thickness of one or more acrylic pressure-sensitive adhesive layers selected from the group consisting of acrylic pressure-sensitive adhesive layer A and acrylic pressure-sensitive adhesive layer B is 0.1 µm or more and less than 10.0 µm. The pressure-sensitive adhesive sheet according to claim 1.   The gel fraction of one or more acrylic pressure-sensitive adhesive layers selected from the group consisting of the acrylic pressure-sensitive adhesive layer A and the acrylic pressure-sensitive adhesive layer B is 10 to 60% by weight. The pressure-sensitive adhesive sheet according to item.   The electrical or electronic device member laminated body which has a laminated structure of the adhesive sheet of any one of Claims 1-6, and an electrical or electronic device member.