JP2015091924A - Adhesive layer for chemical liquid treatment, pressure sensitive adhesive sheet for chemical liquid treatment, surface protection sheet and glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive layer for chemical liquid treatment capable of realizing both chemical liquid infiltration prevention properties, and a suppressed peeling static voltage (antistatic properties) when peeled off from an adherend having no antistatic treatment, and also to provide a pressure sensitive adhesive sheet for chemical liquid treatment having the adhesive layer, a surface protection sheet having the adhesive layer, and a surface-protection-sheet-inclusive glass substrate onto which the surface protection sheet is adhered.SOLUTION: An adhesive layer for chemical liquid treatment is formed of an adhesive composition including a polymer (A) with glass-transition temperature of lower than 0°C. In the adhesive layer for chemical liquid treatment, the ratio of components insoluble to a solvent is 50-90 mass%, and surface resistivity is 10-10Ω/sq.

Description

  The present invention relates to a pressure-sensitive adhesive layer for chemical treatment. Specifically, a pressure-sensitive adhesive layer having chemical solution intrusion-preventing properties and antistatic properties, a pressure-sensitive adhesive sheet formed in the form of a sheet or tape using the same, a surface protective sheet, and the surface protective sheet are affixed It is related with the glass substrate formed. More specifically, the present invention relates to a surface treatment sheet for chemical treatment that can mask a non-treatment target portion (a portion where the influence of the chemical solution is to be excluded) when the adherend is treated with the chemical solution.

  An adhesive sheet (protective sheet) for masking a non-treatment target portion (a portion where the influence of the chemical solution is desired to be eliminated) of the adherend when processing an adherend (material to be treated) with a chemical solution is typically Is configured to include a film-like pressure-sensitive adhesive (pressure-sensitive adhesive layer) and a base material that supports the pressure-sensitive adhesive, and is used by attaching the pressure-sensitive adhesive to an adherend. Such a pressure-sensitive adhesive sheet (protective sheet) for chemical treatment, for example, dissolves glass with a chemical solution (etching solution) for adjusting the thickness of the glass or removing burrs formed on the cut end surface of the glass. Etching treatment, etching treatment that partially corrodes the metal surface with chemical solution (etching solution), connection terminal part of circuit board (printed circuit board, flexible printed circuit board (FPC), etc.) etc. partially with chemical solution (plating solution) It can utilize suitably in the plating process etc. which plate. Patent documents 1 and 2 are mentioned as literature about this kind of technique.

  The protective sheet allows the chemical solution to enter from the surface (the surface directly exposed to the chemical solution, that is, the surface opposite to the side attached to the adherend) or the outer edge (hereinafter also referred to as an end surface or a side surface). The property to be prevented, that is, the chemical solution penetration preventing property (sealability) is required.

  Here, the infiltration of the chemical solution from the outer edge of the protective sheet can also occur from the interface between the adhesive of the protective sheet and the adherend. In order to prevent the intrusion of the chemical solution from such an interface, the adhesive (adhesive layer) constituting the protective sheet closely adheres to the surface of the adherend without any gap (adhesion), and the adhesive strength ( Adhesive strength) is important.

  The protective sheet is peeled off and removed when it is no longer needed. In general, a protective sheet and a plastic material and glass constituting an adherend have high electrical insulation properties, and generate static electricity during friction and peeling. Accordingly, static electricity is generated when the protective sheet is peeled off from the adherend. For this reason, there is a possibility that dust, dust or the like in the air is adsorbed, or unpleasant due to electric shock, and various electrostatic failures such as destruction of circuit boards and connection terminals due to static electricity. Therefore, in order to prevent such problems, the protective sheet is subjected to various antistatic treatments.

  For example, a method is disclosed in which a low molecular surfactant is added to an adhesive, and the surfactant is transferred from the adhesive to an adherend to prevent electrification (see, for example, Patent Document 3). However, in this method, the surfactant easily bleeds on the surface of the pressure-sensitive adhesive, and there is a concern about contamination of the adherend when applied to a protective sheet. Therefore, when a pressure-sensitive adhesive to which a low molecular surfactant is added is applied to the protective sheet, it is difficult to develop sufficient antistatic properties without impairing the properties of the adherend.

  Further, a method is disclosed in which an antistatic agent comprising a polyether polyol and an alkali metal salt is added to an acrylic pressure-sensitive adhesive to suppress bleeding of the antistatic agent on the surface of the pressure-sensitive adhesive (for example, see Patent Document 4). . However, even in this method, bleeding of the antistatic agent is unavoidable, and as a result, when it is actually applied to a protective sheet, if the treatment is performed at a high temperature, the adherend is contaminated by the bleeding phenomenon. End up.

  In addition, a technique related to an antistatic acrylic pressure-sensitive adhesive containing an acrylic copolymer having an alkylene oxide chain in the side chain and an ionic compound is disclosed (Patent Document 5), and both antistatic properties and low contamination are achieved. Yes. However, in this method, there is a possibility that problems related to adhesion such as floating and peeling occur.

JP 2010-53346 A Japanese Patent Laid-Open No. 2003-82299 JP-A-9-165460 JP-A-6-128539 Japanese Patent Application Laid-Open No. 2005-206776

  Therefore, the present invention provides a chemical treatment pressure-sensitive adhesive layer capable of achieving both chemical solution penetration prevention and suppression of peeling voltage (antistatic property) at the time of peeling from a non-antistatic adherend, and the pressure-sensitive adhesive layer. It is intended to provide a pressure-sensitive adhesive sheet for chemical treatment, a surface protective sheet, and a glass substrate with a surface protective sheet to which the surface protective sheet is attached.

The pressure-sensitive adhesive layer for chemical treatment of the present invention is a pressure-sensitive adhesive layer for chemical treatment formed from a pressure-sensitive adhesive composition containing a polymer (A) having a glass transition temperature of less than 0 ° C., and the solvent-insoluble component ratio is It is 50-90 mass%, and surface resistivity is 10 < ³ > -10 < ¹³ > ohm / square.

In the pressure-sensitive adhesive layer for chemical treatment according to the present invention, the pressure-sensitive adhesive composition has a weight-average molecular weight of 1000 or more and less than 30000, and has a cycloaliphatic structure represented by the following general formula (1). It is preferable to contain the (meth) acrylic-type polymer (B) which contains as a monomer component.
CH ₂ = C (R ¹ ) COOR ² (1)
[In Formula (1), R ¹ is a hydrogen atom or a methyl group, and R ² is an alicyclic hydrocarbon group having an alicyclic structure. ]

  As for the adhesive layer for chemical | medical solution processing of this invention, it is preferable that the said adhesive composition contains an ionic compound (C).

  As for the adhesive layer for chemical | medical solution processing of this invention, it is preferable that the said adhesive composition contains the compound (D) which has a polyoxyalkylene chain.

  In the pressure-sensitive adhesive layer for chemical treatment according to the present invention, the pressure-sensitive adhesive composition contains 0.005 to 2 parts by mass of the (meth) acrylic polymer (B) with respect to 100 parts by mass of the polymer (A). It is preferable to do.

  In the pressure-sensitive adhesive layer for chemical treatment according to the present invention, the pressure-sensitive adhesive composition preferably contains 0.005 to 2 parts by mass of the ionic compound (C) with respect to 100 parts by mass of the polymer (A). .

  The pressure-sensitive adhesive layer for chemical treatment according to the present invention contains 0.005 to 1 part by mass of the compound (D) having the polyoxyalkylene chain with respect to 100 parts by mass of the polymer (A). It is preferable to do.

  In the chemical treatment adhesive layer of the present invention, the polymer (A) is preferably a (meth) acrylic polymer (a).

  In the chemical treatment adhesive layer of the present invention, the alicyclic hydrocarbon group of the (meth) acrylic monomer having an alicyclic structure preferably has a bridged ring structure.

  In the chemical treatment adhesive layer of the present invention, the glass transition temperature of the (meth) acrylic polymer (B) is preferably 0 to 300 ° C.

  In the chemical treatment adhesive layer of the present invention, the ionic compound (C) is preferably an alkali metal salt and / or an ionic liquid.

  In the pressure-sensitive adhesive layer for chemical treatment according to the present invention, the alkali metal salt is preferably a lithium salt.

  In the chemical treatment adhesive layer of the present invention, the ionic liquid is preferably at least one of a nitrogen-containing onium salt, a sulfur-containing onium salt, and a phosphorus-containing onium salt.

［式（Ｃ１）中のＲ_ａは、炭素数４から２０の炭化水素基を表し、前記炭化水素基の一部がヘテロ原子で置換された官能基であってもよく、Ｒ_ｂおよびＲ_ｃは、同一または異なって、水素または炭素数１から１６の炭化水素基を表し、前記炭化水素基の一部がヘテロ原子で置換された官能基であってもよい。但し、窒素原子が２重結合を含む場合、Ｒ_ｃはない。］
［式（Ｃ２）中のＲ_ｄは、炭素数２から２０の炭化水素基を表し、前記炭化水素基の一部がヘテロ原子で置換された官能基であってもよく、Ｒ_ｅ、Ｒ_ｆ、およびＲ_ｇは、同一または異なって、水素または炭素数１から１６の炭化水素基を表し、前記炭化水素基の一部がヘテロ原子で置換された官能基であってもよい。］
［式（Ｃ３）中のＲ_ｈは、炭素数２から２０の炭化水素基を表し、前記炭化水素基の一部がヘテロ原子で置換された官能基であってもよく、Ｒ_ｉ、Ｒ_ｊ、およびＲ_ｋは、同一または異なって、水素または炭素数１から１６の炭化水素基を表し、前記炭化水素基の一部がヘテロ原子で置換された官能基であってもよい。］
［式（Ｃ４）中のＺは、窒素、硫黄、またはリン原子を表し、Ｒ_ｌ、Ｒ_ｍ、Ｒ_ｎ、およびＲ_ｏは、同一または異なって、炭素数１から２０の炭化水素基を表し、前記炭化水素基の一部がヘテロ原子で置換された官能基であってもよい。但しＺが硫黄原子の場合、Ｒ_ｏはない。］
［式（Ｃ５）中のＲ_Ｐは、炭素数１から１８の炭化水素基を表し、前記炭化水素基の一部がヘテロ原子で置換された官能基であってもよい。］ In the adhesive layer for chemical treatment according to the present invention, the ionic liquid preferably contains one or more cations represented by the following general formulas (C1) to (C5).

[R _a in Formula (C1) represents a hydrocarbon group having 4 to 20 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom, and R _b and R _c May be the same or different and each represents hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and a part of the hydrocarbon group may be a functional group substituted with a hetero atom. However, when the nitrogen atom contains a double bond, there is no R _c . ]
[R _d in Formula (C2) represents a hydrocarbon group having 2 to 20 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom, and R _e , R _f And R _g may be the same or different and each represents hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and a part of the hydrocarbon group may be a functional group substituted with a hetero atom. ]
[R _h in the formula (C3) represents a hydrocarbon group having from 2 to 20 carbon atoms, a part of the hydrocarbon group may be substituted by a functional group with a hetero atom, R _i, R _j , And R _k may be the same or different and each represents hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and a part of the hydrocarbon group may be a functional group substituted with a hetero atom. ]
[Z in Formula (C4) represents a nitrogen, sulfur, or phosphorus atom, and R ₁ , R _m , R _n , and R _o are the same or different and each represents a hydrocarbon group having 1 to 20 carbon atoms. A functional group in which a part of the hydrocarbon group is substituted with a hetero atom may be used. However, when Z is a sulfur atom, there is no _Ro . ]
[R _P in the formula (C5) represents a hydrocarbon group having 1 to 18 carbon atoms, a part of the hydrocarbon group may be substituted by a functional group with a heteroatom. ]

  In the adhesive layer for chemical treatment according to the present invention, the compound (D) having a polyoxyalkylene chain is preferably an organopolysiloxane having a polyoxyalkylene chain.

［式（Ｄ１）中のＲ_１は１価の有機基、Ｒ_２，Ｒ_３及びＲ_４はアルキレン基、Ｒ_５は水素もしくは有機基、ｍ及びｎは０〜１０００の整数。但し、ｍ,ｎが同時に０となることはない。ａ及びｂは０〜１０００の整数。但し、ａ,ｂが同時に０となることはない。］
［式（Ｄ２）中のＲ_１は１価の有機基、Ｒ_２，Ｒ_３及びＲ_４はアルキレン基、Ｒ_５は水素もしくは有機基、ｍは１〜２０００の整数。ａ及びｂは０〜１０００の整数。但し、ａ,ｂが同時に０となることはない。］
［式（Ｄ３）中のＲ_１は１価の有機基、Ｒ_２，Ｒ_３及びＲ_４はアルキレン基、Ｒ_５は水素もしくは有機基、ｍは１〜２０００の整数。ａ及びｂは０〜１０００の整数。但し、ａ,ｂが同時に０となることはない。］ In the chemical treatment adhesive layer of the present invention, the organopolysiloxane having a polyoxyalkylene chain is preferably an organopolysiloxane represented by the following general formulas (D1) to (D3).

[R ₁ in the formula (D1) is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is hydrogen or an organic group, m and n are integers of 0 to 1000. However, m and n are not 0 at the same time. a and b are integers of 0 to 1000. However, a and b are not 0 at the same time. ]
[R ₁ in the formula (D2) is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is hydrogen or an organic group, and m is an integer of 1 to 2000. a and b are integers of 0 to 1000. However, a and b are not 0 at the same time. ]
[In Formula (D3), R ₁ is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is hydrogen or an organic group, and m is an integer of 1 to 2000. a and b are integers of 0 to 1000. However, a and b are not 0 at the same time. ]

  It is preferable that the adhesive layer for chemical | medical solution processing of this invention contains a hydroxyl group containing monomer as a monomer component which comprises the said (meth) acrylic-type polymer (a).

  The pressure-sensitive adhesive layer for chemical treatment of the present invention contains an alkylene oxide group having an average addition mole number of oxyalkylene units of 3 to 40 with respect to the total amount of monomer components constituting the (meth) acrylic polymer (a). It is preferable to contain 5.0 mass% or less of a reactive monomer.

  The pressure-sensitive adhesive sheet for chemical treatment according to the present invention is preferably formed by forming the pressure-sensitive adhesive layer on at least one surface of a support.

  In the chemical treatment adhesive sheet of the present invention, the support is preferably a plastic film that has been subjected to antistatic treatment.

  The surface protective sheet of the present invention is preferably composed of the chemical treatment adhesive sheet.

  The glass substrate with a surface protective sheet of the present invention is preferably formed by attaching the surface protective sheet to a glass substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive layer for chemical | medical solution processing which can aim at the coexistence of suppression of chemical | medical solution penetration | invasion, and suppression of the stripping voltage at the time of peeling from an adherend which is not antistatic (antistatic property) It is possible to provide a chemical treatment pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer, a surface protective sheet, and a glass substrate with a surface protective sheet to which the surface protective sheet is attached.

It is sectional drawing which shows typically the example of 1 structure of the protective sheet for chemical | medical solution processes. It is sectional drawing which shows typically the other structural example of the protective sheet for chemical | medical solution processing. It is sectional drawing which shows typically the other structural example of the protective sheet for chemical | medical solution processing. It is sectional drawing which shows typically the other structural example of the protective sheet for chemical | medical solution processing. It is a schematic block diagram of the electric potential measurement part used for the measurement of peeling band voltage in an Example etc.

The pressure-sensitive adhesive layer for chemical treatment of the present invention is a pressure-sensitive adhesive layer for chemical treatment formed from a pressure-sensitive adhesive composition containing a polymer (A) having a glass transition temperature of less than 0 ° C., and the solvent-insoluble component ratio is It is 50-90 mass%, and surface resistivity is 10 < ³ > -10 < ¹³ > ohm / square. When the solvent-insoluble component ratio is in the range of 50 to 90% by mass, the adhesion reliability (adhesion, adhesiveness, removability) is improved, and it is possible to prevent the infiltration of the chemical solution. Further, when the surface resistivity is in the range of 10 ³ to 10 ¹³ Ω / □, it is possible to suppress the generation of the peeling band voltage (to impart antistatic properties).

  Hereinafter, a pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer for chemical treatment of the present invention (sometimes simply referred to as “pressure-sensitive adhesive layer”), a pressure-sensitive adhesive formed by the pressure-sensitive adhesive composition Layer, a pressure-sensitive adhesive sheet for chemical treatment (sometimes simply referred to as “pressure-sensitive adhesive sheet”), a surface protective sheet (sometimes simply referred to as “protective sheet”), and the surface protective sheet. The details of the glass substrate to which is attached will be described.

<Overall structure of pressure-sensitive adhesive sheet for chemical treatment (surface protective sheet)>
The chemical treatment pressure-sensitive adhesive sheet (surface protective sheet) disclosed herein includes a support and a pressure-sensitive adhesive layer provided on at least one surface of the support. The shape of the pressure-sensitive adhesive sheet may be a sheet shape, and may be, for example, a roll shape or a single plate shape with a separator.
A typical configuration example of such an adhesive sheet is schematically shown in FIG. The pressure-sensitive adhesive sheet 10 includes a sheet-like support (for example, a resin-made sheet-like base material) 1 and a pressure-sensitive adhesive layer 2 provided on one surface (one surface) thereof. The pressure-sensitive adhesive sheet 10 has a predetermined portion (a portion to be protected, typically a portion where the chemical solution is desired to be excluded) before the pressure-sensitive adhesive layer 2 side is treated with the chemical solution on the adherend (material to be treated). (Hereinafter also referred to as “non-processing target portion”). Thereby, the said non-process target part can be protected from a chemical | medical solution. Moreover, the adhesive sheet 10 before use (that is, before application to the adherend) typically has a surface of the adhesive layer 2 (applied surface to the adherend. The surface is also referred to as “surface”.) Is a form protected by a release liner 3 having at least a pressure-sensitive adhesive layer 2 side as a release surface. Alternatively, the other surface of the support 1 (the back surface of the surface on which the pressure-sensitive adhesive layer 2 is provided) is a peeling surface, and the pressure-sensitive adhesive layer 2 is formed on the other surface by winding the pressure-sensitive adhesive sheet 10 in a roll shape. It may be in a form in which the surface (adhesive surface) is protected by contact. The pressure-sensitive adhesive sheet 10 may be a double-sided pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive layer 2 is provided on each surface of the support 1. In that case, the adhesive surface (adhesive surface) of each pressure-sensitive adhesive layer to the adherend may be protected by a release liner 3 having at least a pressure-sensitive adhesive layer side as a release surface. The form wound by roll shape via the release liner 3 used as the surface may be sufficient. Moreover, as shown in FIG. 3, the form which has the antistatic layer 4 in the other surface (back surface of the surface in which the adhesive layer 2 is provided) of the support body 1 may be sufficient. Furthermore, as shown in FIG. 4, the form which has the antistatic layer 4 in the middle of the support body 1 and the adhesive layer 2 may be sufficient. The “sheet” in the present invention includes a film whose thickness is relatively thinner than the sheet and a tape generally referred to as an adhesive tape.

<Polymer (A)>
The pressure-sensitive adhesive layer for chemical treatment according to the present invention is formed from a pressure-sensitive adhesive composition containing a polymer (A) having a glass transition temperature of less than 0 ° C. The polymer (A) is not particularly limited as long as the glass transition temperature is less than 0 ° C. For example, an adhesive such as an acrylic polymer, a rubber polymer, a silicone polymer, a polyurethane polymer, and a polyester polymer Various polymers generally used can be used. In particular, it is preferable to use a (meth) acrylic polymer which is preferably used in the pressure-sensitive adhesive layer of the present invention, is easily compatible with the (meth) acrylic polymer (B) described later, and has high transparency.

  The glass transition temperature (Tg) of the polymer (A) is less than 0 ° C, preferably less than -10 ° C, more preferably less than -40 ° C, and usually -80 ° C or higher. When the glass transition temperature of the polymer (A) is 0 ° C. or higher, the polymer is difficult to flow, wetness to the adherend (protected body) becomes insufficient, and adhesion may be lowered. In addition, the fact that the glass transition temperature of the polymer (A) is not too low can contribute to prevention of chemical solution intrusion (typically, chemical solution infiltration mainly due to swelling of the adhesive with the chemical solution).

In the present specification, “glass transition temperature when homopolymer is formed” means “glass transition temperature of homopolymer of the monomer”, and may be referred to as a certain monomer (“monomer X”). ) Is the glass transition temperature (Tg) of a polymer formed using only the monomer component. Specifically, numerical values are listed in “Polymer Handbook” (3rd edition, John Wiley & Sons, Inc, 1989).
In addition, the glass transition temperature (Tg) of the homopolymer which is not described in the said literature says the value obtained by the following measuring methods, for example.
That is, in a reactor equipped with a thermometer, a stirrer, a nitrogen introduction tube, and a reflux condenser, 100 parts by mass of monomer X, 0.2 parts by mass of 2,2′-azobisisobutyronitrile and ethyl acetate 200 as a polymerization solvent. Stirring is performed for 1 hour while introducing nitrogen gas. After removing oxygen in the polymerization system in this way, the temperature is raised to 63 ° C. and the reaction is carried out for 10 hours. Subsequently, it cools to room temperature and the homopolymer solution with a solid content concentration of 33 mass% is obtained. Next, this homopolymer solution is cast-coated on a release liner and dried to prepare a test sample (sheet-like homopolymer) having a thickness of about 2 mm. Then, about 1 to 2 mg of this test sample was weighed in an aluminum open cell, and a nitrogen atmosphere of 50 ml / min was used using a temperature modulation DSC (trade name “Q-2000”, manufactured by T.A. Instruments Inc.). Under the temperature rising rate of 5 ° C./min, the reversing heat flow (specific heat component) behavior of the homopolymer is obtained.
Referring to JIS-K-7121, the lower line of the obtained Reversing Heat Flow and the straight line that is equidistant in the vertical axis from the straight line obtained by extending the high temperature base line, and the stepwise change of the glass transition The temperature at the point where the curve of the part intersects is the glass transition temperature (Tg) when the homopolymer is used.

  Further, the polymer (A) has a weight average molecular weight (Mw) of preferably 30,000 to 5,000,000, more preferably 100,000 to 2,000,000, still more preferably 200,000 to 1,000,000. When the weight average molecular weight (Mw) is less than 30,000, the cohesive force of the pressure-sensitive adhesive (layer) may be insufficient, and the chemical solution may easily enter. On the other hand, when the weight average molecular weight (Mw) exceeds 5,000,000, the fluidity of the pressure-sensitive adhesive is lowered, the wetness to the adherend is insufficient, and the adhesion may be lowered.

<(Meth) acrylic polymer (a)>
Below, the (meth) acrylic-type polymer (a) which is a suitable specific example of the said polymer (A) is explained in full detail.

  The (meth) acrylic polymer (a) is, for example, a polymer containing 50% by mass or more of a (meth) acrylic acid alkyl ester having a linear or branched alkyl group having 1 to 20 carbon atoms as a monomer component. Preferably there is. In addition, the (meth) acrylic polymer (a) can have a configuration in which (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms is used alone or in combination of two or more.

  The method for obtaining the (meth) acrylic polymer (a) is not particularly limited, and is generally used as a method for synthesizing (meth) acrylic polymers such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and radiation curing polymerization. Various polymerization methods used in the above can be applied. In addition, when using the adhesive layer for chemical | medical solution processing (adhesive sheet) of this invention for the surface protection sheet mentioned later, it is a preferable aspect to use solution polymerization and emulsion polymerization suitably.

  As a ratio of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms, it is 50 with respect to the total amount of monomer components (100% by mass) for preparing the (meth) acrylic polymer (a). The mass% is preferably 50% to 99.9% by mass, more preferably 60 to 98% by mass, and particularly preferably 70 to 95% by mass. When it is within the above range, preferable adhesive properties (adhesiveness, adhesiveness, removability) are obtained for the chemical treatment adhesive layer (adhesive sheet, surface protective sheet).

Examples of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and isopropyl (meth) acrylate. Butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, (meth) Hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, (meth ) Decyl acrylate, isodecyl (meth) acrylate, (meth) acrylate Decyl, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate (Meth) acrylic acid C _1-20 alkyl esters such as nonadecyl (meth) acrylate and eicosyl (meth) acrylate [preferably (meth) acrylic acid C _2-14 alkyl ester, more preferably (meth) acrylic acid C _2-10 alkyl ester] and the like. In addition, (meth) acrylic acid alkyl ester means acrylic acid alkyl ester and / or methacrylic acid alkyl ester, and “(meth)...” Has the same meaning.

  The (meth) acrylic polymer (a) can be copolymerized with the (meth) acrylic acid alkyl ester as necessary for the purpose of modifying cohesive strength, heat resistance, crosslinkability, etc. The monomer component (copolymerizable monomer) may be included. Therefore, the said (meth) acrylic-type polymer (a) may contain the copolymerizable monomer with the (meth) acrylic-acid alkylester as a main component. As the copolymerizable monomer, a monomer having a polar group can be suitably used.

As a specific example of the copolymerizable monomer,
Carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid;
2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, Hydroxyl group-containing monomers such as (meth) acrylic acid hydroxyalkyl such as (meth) acrylic acid 10-hydroxydecyl, (meth) acrylic acid 12-hydroxylauryl, (4-hydroxymethylcyclohexyl) methyl methacrylate;
Acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride;
Sulphonic acid groups such as styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid Containing monomers;
Phosphate group-containing monomers such as 2-hydroxyethylacryloyl phosphate;
(Meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N, N-diisopropyl (meth) acrylamide, N, N-di N, N-dialkyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) such as (n-butyl) (meth) acrylamide, N, N-di (t-butyl) (meth) acrylamide Acrylamide, N-butyl (meth) acrylamide, Nn-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-ethylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-methoxymethyl ( (Meth) acrylamide, N-methoxyethyl (meta) Acrylamide, N- butoxymethyl (meth) acrylamide, N- acryloyl morpholine, etc. (N- substituted) amide monomers;
Succinimide monomers such as N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyoctamethylene succinimide;
Maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide;
Itaconimides such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide System monomers;
Vinyl esters such as vinyl acetate and vinyl propionate;
N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N- Vinyloxazole, N- (meth) acryloyl-2-pyrrolidone, N- (meth) acryloylpiperidine, N- (meth) acryloylpyrrolidine, N-vinylmorpholine, N-vinyl-2-piperidone, N-vinyl-3-morpholinone N-vinyl-2-caprolactam, N-vinyl-1,3-oxazin-2-one, N-vinyl-3,5-morpholinedione, N-vinylpyrazole, N-vinylisoxazole, N-vinylthiazole, Contains nitrogen such as N-vinylisothiazole and N-vinylpyridazine Ring-based monomer;
N-vinylcarboxylic acid amides;
Lactam monomers such as N-vinylcaprolactam;
Cyano group-containing monomers such as acrylonitrile and methacrylonitrile;
(Meth) acrylic such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate Acid aminoalkyl monomers;
(Meth) acrylic acid alkoxyalkyl monomers such as (meth) acrylic acid methoxyethyl, (meth) acrylic acid ethoxyethyl, (meth) acrylic acid propoxyethyl, (meth) acrylic acid butoxyethyl, (meth) acrylic acid ethoxypropyl ;
Styrene monomers such as styrene and α-methylstyrene;
Epoxy group-containing acrylic monomers such as (meth) glycidyl acrylate;
(Meth) acrylic acid tetrahydrofurfuryl, fluorine atom-containing (meth) acrylate, silicone (meth) acrylate and other heterocyclic rings, halogen atoms, silicon atoms and the like, acrylic ester monomers;
Olefin monomers such as isoprene, butadiene, isobutylene;
Vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether;
Vinyl esters such as vinyl acetate and vinyl propionate;
Aromatic vinyl compounds such as vinyltoluene and styrene;
Olefins or dienes such as ethylene, butadiene, isoprene, isobutylene;
Vinyl ethers such as vinyl alkyl ethers;
Vinyl chloride;
Sulfonic acid group-containing monomers such as sodium vinyl sulfonate;
Imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide;
Isocyanate group-containing monomers such as 2-isocyanatoethyl (meth) acrylate;
Acryloylmorpholine;
(Meth) acrylic acid ester having an alicyclic hydrocarbon group such as cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate;
(Meth) acrylic acid ester having an aromatic hydrocarbon group such as phenyl (meth) acrylate and phenoxyethyl (meth) acrylate;
(Meth) acrylic acid ester obtained from terpene compound derivative alcohol. These copolymerizable monomers can be used alone or in combination of two or more.

  When the (meth) acrylic polymer (a) contains a copolymerizable monomer together with the (meth) acrylic acid alkyl ester as a main component, the hydroxyl group-containing monomer and the carboxyl are particularly preferred as the copolymerizable monomer. A group-containing monomer can be preferably used. Among them, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate can be suitably used as the hydroxyl group-containing monomer, and acrylic acid can be suitably used as the carboxyl group-containing monomer.

  Although there is no restriction | limiting in particular as content of the said copolymerizable monomer, Usually, the said copolymerizable monomer is 0.00 with respect to the monomer component whole quantity (100 mass%) for preparing the said acrylic polymer (a). The content is preferably 01 to 40% by mass, more preferably 0.1 to 30% by mass, and still more preferably 0.5 to 20% by mass. By containing 0.01% by mass or more of the copolymerizable monomer, it is possible to prevent a decrease in cohesive force of the pressure-sensitive adhesive (layer) and to prevent contamination when peeled from the adherend. Moreover, by making content of the said copolymerizable monomer into 40 mass% or less, it can prevent that cohesion force becomes high too much and can improve the tack feeling in normal temperature (25 degreeC).

  The (meth) acrylic polymer (a) may further contain 5.0% by mass or less of an alkylene oxide group-containing reactive monomer having an average addition mole number of oxyalkylene units of 3 to 40 as a monomer component. it can.

  The average addition mole number of oxyalkylene units to the alkylene oxide group-containing reactive monomer is preferably 3 to 40, more preferably 4 to 35, from the viewpoint of compatibility with the ionic compound. It is especially preferable that it is 5-30. When the average added mole number is 3 or more, the effect of reducing the contamination of the adherend (protected body) tends to be obtained efficiently. Further, when the average added mole number is larger than 40, the interaction with the ionic compound that acts as an antistatic agent is large, and the pressure-sensitive adhesive composition tends to be in a gel form, which makes coating difficult. Absent. In addition, the terminal of the oxyalkylene chain may be substituted with other functional groups or the like as a hydroxyl group.

  The alkylene oxide group-containing reactive monomer may be used alone or in combination of two or more, but the total amount of monomer components of the (meth) acrylic polymer (a) (100% by mass) ) Is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, still more preferably 3.0% by mass or less, and 1.0% by mass or less. It is particularly preferred that When the content of the alkylene oxide group-containing reactive monomer exceeds 5.0% by mass, the interaction with the ionic compound acting as an antistatic agent increases, ionic conduction is hindered, and the antistatic property is lowered. This is not preferable.

  Examples of the oxyalkylene unit of the alkylene oxide group-containing reactive monomer include those having an alkylene group having 1 to 6 carbon atoms, such as an oxymethylene group, an oxyethylene group, an oxypropylene group, and an oxybutylene group. It is done. The hydrocarbon group of the oxyalkylene chain may be linear or branched.

  Furthermore, the alkylene oxide group-containing reactive monomer is more preferably a reactive monomer having an ethylene oxide group. By using a (meth) acrylic polymer having a reactive monomer having an ethylene oxide group as the base polymer, the compatibility between the base polymer and the ionic compound is improved, and bleeding to the adherend is suitably suppressed, and the A contaminating adhesive (layer) is obtained.

  Examples of the alkylene oxide group-containing reactive monomer include (meth) acrylic acid alkylene oxide adducts and reactive surfactants having reactive substituents such as acryloyl group, methacryloyl group, and allyl group in the molecule. Can be mentioned.

  Specific examples of the (meth) acrylic acid alkylene oxide adduct include, for example, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, polyethylene glycol-polybutylene glycol (meth) ) Acrylate, polypropylene glycol-polybutylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, ethoxy polyethylene glycol (meth) acrylate, butoxy polyethylene glycol (meth) acrylate, octoxy polyethylene glycol (meth) acrylate, lauroxy polyethylene Glycol (meth) acrylate, stearoxy polyethylene glycol Le (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, methoxy polypropylene glycol (meth) acrylate, octoxypolyethylene glycol - polypropylene glycol (meth) acrylate.

  Specific examples of the reactive surfactant include, for example, an anionic reactive surfactant having a (meth) acryloyl group or an allyl group, a nonionic reactive surfactant, and a cationic reactive surfactant. Is mentioned.

  Examples of the anionic reactive surfactant include those represented by formulas (A1) to (A10).

［式（Ａ１）中のＲ_１は水素またはメチル基を表し、Ｒ_２は炭素数１から３０の炭化水素基またはアシル基を表し、Ｘはアニオン性親水基を表し、Ｒ_３およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］。

[R ₁ in Formula (A1) represents hydrogen or a methyl group, R ₂ represents a hydrocarbon group having 1 to 30 carbon atoms or an acyl group, X represents an anionic hydrophilic group, R ₃ and R ₄ are The alkylene groups having 1 to 6 carbon atoms are the same or different, and the average added mole number m and n are 0 to 40, where (m + n) represents 3 to 40. ].

［式（Ａ２）中のＲ_１は水素またはメチル基を表し、Ｒ_２およびＲ_７は同一または異なって、炭素数１から６のアルキレン基を表し、Ｒ_３およびＲ_５は同一または異なって、水素またはアルキル基を表し、Ｒ_４およびＲ_６は同一または異なって、水素、アルキル基、ベンジル基またはスチレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］。

[R ₁ in Formula (A2) represents hydrogen or a methyl group, R ₂ and R ₇ are the same or different, represent an alkylene group having 1 to 6 carbon atoms, and R ₃ and R ₅ are the same or different, Represents hydrogen or an alkyl group, R ₄ and R ₆ are the same or different and represent hydrogen, an alkyl group, a benzyl group or a styrene group, X represents an anionic hydrophilic group, and the average number of added moles m and n are 0 to 40, where (m + n) represents a number from 3 to 40. ].

［式（Ａ３）中のＲ_１は水素またはメチル基を表し、Ｒ_２は炭素数１から６のアルキレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｎは３〜４０の数を表す。］。

[R ₁ in Formula (A3) represents hydrogen or a methyl group, R ₂ represents an alkylene group having 1 to 6 carbon atoms, X represents an anionic hydrophilic group, and the average number of added moles n is 3 to 40 Represents a number. ].

［式（Ａ４）中のＲ_１は水素またはメチル基を表し、Ｒ_２は炭素数１から３０の炭化水素基またはアシル基を表し、Ｒ_３およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］。

[R ₁ in Formula (A4) represents hydrogen or a methyl group, R ₂ represents a hydrocarbon group or acyl group having 1 to 30 carbon atoms, and R ₃ and R ₄ may be the same or different, and 6 represents an alkylene group, X represents an anionic hydrophilic group, the average added mole number m and n are 0 to 40, and (m + n) represents a number of 3 to 40. ].

［式（Ａ５）中のＲ_１は炭化水素基、アミノ基、カルボン酸残基を表し、Ｒ_２は炭素数１から６のアルキレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｎは３〜４０の整数を表す。］。

[R ₁ in Formula (A5) represents a hydrocarbon group, an amino group, or a carboxylic acid residue, R ₂ represents an alkylene group having 1 to 6 carbon atoms, X represents an anionic hydrophilic group, and average added mole The number n represents an integer of 3 to 40. ].

［式（Ａ６）中のＲ_１は炭素数１から３０の炭化水素基、Ｒ_２は水素または炭素数１から３０の炭化水素基を表し、Ｒ_３は水素またはプロペニル基を表し、Ｒ_４は炭素数１から６のアルキレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｎは３〜４０の数を表す。］。

[In Formula (A6), R ₁ represents a hydrocarbon group having 1 to 30 carbon atoms, R ₂ represents hydrogen or a hydrocarbon group having 1 to 30 carbon atoms, R ₃ represents hydrogen or a propenyl group, and R ₄ represents An alkylene group having 1 to 6 carbon atoms is represented, X represents an anionic hydrophilic group, and the average added mole number n represents a number of 3 to 40. ].

［式（Ａ７）中のＲ_１は水素またはメチル基を表し、Ｒ_２およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、Ｒ_３は炭素数１から３０の炭化水素基を表し、Ｍは水素、アルカリ金属、アンモニウム基、またはアルカノールアンモニウム基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］。

[R ₁ in Formula (A7) represents hydrogen or a methyl group, R ₂ and R ₄ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms, and R ₃ represents a hydrocarbon having 1 to 30 carbon atoms. Represents a group, M represents hydrogen, an alkali metal, an ammonium group, or an alkanol ammonium group, and the average number of added moles m and n is 0 to 40, where (m + n) represents a number of 3 to 40. ].

［式（Ａ８）中のＲ_１およびＲ_５は同一または異なって、水素またはメチル基を表し、Ｒ_２およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、Ｒ_３は炭素数１から３０の炭化水素基を表し、Ｍは水素、アルカリ金属、アンモニウム基、またはアルカノールアンモニウム基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］

[And _{R 1} and _{R 5} in the formula (A8) the same or different, represent a hydrogen or a methyl group, _{R 2} and _{R 4} are the same or different and each represents an alkylene group having a carbon number of 1 to 6, _{R 3} is Represents a hydrocarbon group having 1 to 30 carbon atoms, M represents hydrogen, an alkali metal, an ammonium group, or an alkanol ammonium group, and the average number of added moles m and n is 0 to 40, provided that (m + n) is 3 to 40 Represents a number. ]

［式（Ａ９）中のＲ_１は炭素数１から６のアルキレン基を表し、Ｒ_２は炭素数１から３０の炭化水素基を表し、Ｍは水素、アルカリ金属、アンモニウム基、またはアルカノールアンモニウム基を表し、平均付加モル数ｎは３〜４０の数を表す。］

[R ₁ in Formula (A9) represents an alkylene group having 1 to 6 carbon atoms, R ₂ represents a hydrocarbon group having 1 to 30 carbon atoms, and M represents hydrogen, an alkali metal, an ammonium group, or an alkanol ammonium group. The average added mole number n represents a number of 3 to 40. ]

［式（Ａ１０）中のＲ_１、Ｒ_２、およびＲ_３は同一または異なって、水素またはメチル基を表し、Ｒ_４は炭素数０から３０の炭化水素基（炭素数０の場合はＲ_４がないことを示す）を表し、Ｒ_５およびＲ_６は同一または異なって、炭素数１から６のアルキレン基を表し、Ｘはアニオン性親水基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］。

[R ₁ , R ₂ and R _{3 in} Formula (A10) are the same or different and represent hydrogen or a methyl group, and R ₄ represents a hydrocarbon group having 0 to 30 carbon atoms (in the case of 0 carbon atoms, R ₄ R ₅ and R ₆ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms, X represents an anionic hydrophilic group, and average added mole numbers m and n are 0 to 40, where (m + n) represents a number from 3 to 40. ].

  X in the formulas (A1) to (A6) and (A10) represents an anionic hydrophilic group. Examples of the anionic hydrophilic group include those represented by the following formulas (a1) to (a2).

［式（ａ１）中のＭ_１は水素、アルカリ金属、アンモニウム基、またはアルカノールアンモニウム基を表す。］

[M ₁ in Formula (a1) represents hydrogen, an alkali metal, an ammonium group, or an alkanol ammonium group. ]

［式（ａ２）中のＭ_２およびＭ_３は同一または異なって、水素、アルカリ金属、アンモニウム基、またはアルカノールアンモニウム基を表す。］

[M ₂ and M _{3 in} Formula (a2) are the same or different and represent hydrogen, an alkali metal, an ammonium group, or an alkanol ammonium group. ]

  Examples of the nonionic reactive surfactant include those represented by the formulas (N1) to (N6).

［式（Ｎ１）中のＲ_１は水素またはメチル基を表し、Ｒ_２は炭素数１から３０の炭化水素基またはアシル基を表し、Ｒ_３およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］

[R ₁ in Formula (N1) represents hydrogen or a methyl group, R ₂ represents a hydrocarbon group or an acyl group having 1 to 30 carbon atoms, and R ₃ and R ₄ may be the same or different, and 6 represents an alkylene group, and average addition mole numbers m and n are 0 to 40, where (m + n) represents a number of 3 to 40. ]

［式（Ｎ２）中のＲ_１は水素またはメチル基を表し、Ｒ_２、Ｒ_３およびＲ_４は同一または異なって、炭素数１から６のアルキレン基を表し、平均付加モル数ｎ、ｍ、およびｌは０〜４０であって、（ｎ＋ｍ＋ｌ）が３〜４０となる数を表す。］

[R ₁ in Formula (N2) represents hydrogen or a methyl group, R ₂ , R ₃ and R ₄ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms, and the average number of added moles n, m, And l represents 0 to 40, and (n + m + 1) represents a number from 3 to 40. ]

［式（Ｎ３）中のＲ_１は水素またはメチル基を表し、Ｒ_２およびＲ_３は同一または異なって、炭素数１から６のアルキレン基を表し、Ｒ_４は炭素数１から３０の炭化水素基またはアシル基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］

[R ₁ in Formula (N3) represents hydrogen or a methyl group, R ₂ and R ₃ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms, and R ₄ represents a hydrocarbon having 1 to 30 carbon atoms. A group or an acyl group, the average number of added moles m and n is 0 to 40, where (m + n) represents a number of 3 to 40. ]

［式（Ｎ４）中のＲ_１およびＲ_２は同一または異なって、炭素数１から３０の炭化水素基を表し、Ｒ_３は水素またはプロペニル基を表し、Ｒ_４は炭素数１から６のアルキレン基を表し、平均付加モル数ｎは３〜４０の数を表す。］

[R ₁ and R _{2 in} formula (N4) are the same or different and each represents a hydrocarbon group having 1 to 30 carbon atoms, R ₃ represents hydrogen or a propenyl group, and R ₄ represents an alkylene having 1 to 6 carbon atoms Represents the group, and the average addition mole number n represents a number of 3 to 40. ]

［式（Ｎ５）中のＲ_１およびＲ_３は同一または異なって、炭素数１から６のアルキレン基を表し、Ｒ_２およびＲ_４は同一または異なって、水素、炭素数１から３０の炭化水素基、またはアシル基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］

[In formula (N5), R ₁ and R ₃ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms; R ₂ and R ₄ are the same or different and represent hydrogen or a hydrocarbon having 1 to 30 carbon atoms; A group or an acyl group, and the average addition mole numbers m and n are 0 to 40, where (m + n) represents a number of 3 to 40. ]

［式（Ｎ６）中のＲ_１、Ｒ_２、およびＲ_３は同一または異なって、水素またはメチル基を表し、Ｒ_４は炭素数０から３０の炭化水素基（炭素数０の場合はＲ_４がないことを示す）を表し、Ｒ_５およびＲ_６は同一または異なって、炭素数１から６のアルキレン基を表し、平均付加モル数ｍおよびｎは０〜４０、ただし（ｍ＋ｎ）は３〜４０の数を表す。］

[R ₁ , R ₂ and R _{3 in} Formula (N6) are the same or different and represent hydrogen or a methyl group, and R ₄ represents a hydrocarbon group having 0 to 30 carbon atoms (in the case of 0 carbon atoms, R ₄ R ₅ and R ₆ are the same or different and each represents an alkylene group having 1 to 6 carbon atoms, and the average added mole numbers m and n are 0 to 40, provided that (m + n) is 3 to 3. The number of 40 is represented. ]

  Moreover, as a specific commercial item of the said alkylene oxide group containing reactive monomer, for example, Blemmer PME-400, Blemmer PME-1000, Blemmer 50POEP-800B (all are made by NOF Corporation), Latem PD-420 Latemul PD-430 (all are manufactured by Kao Corporation), Adekaria soap ER-10, Adekaria soap NE-10 (all are manufactured by Asahi Denka Kogyo Co., Ltd.), and the like.

  In addition, the (meth) acrylic polymer (a) may contain a polyfunctional monomer as necessary in order to adjust the cohesive force of the obtained pressure-sensitive adhesive layer.

  Examples of the polyfunctional monomer include (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, penta Erythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,2-ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,12-dodecanediol di (meth) Acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, epoxy acrylate Polyester acrylate, urethane acrylate, butyl di (meth) acrylate, hexyl di (meth) acrylate. Among these, trimethylolpropane tri (meth) acrylate, hexanediol di (meth) acrylate, and dipentaerythritol hexa (meth) acrylate can be preferably used. The said polyfunctional monomer can be used individually or in combination of 2 or more types.

  Although the content of the polyfunctional monomer varies depending on the molecular weight, the number of functional groups, and the like, the content of the polyfunctional monomer is 0.00 with respect to the total amount of monomer components (100% by mass) for preparing the (meth) acrylic polymer (a). The content is preferably from 0.01 to 3% by mass, more preferably from 0.02 to 2% by mass, and still more preferably from 0.03 to 1% by mass. When content of the said polyfunctional monomer exceeds 3 mass%, for example, the cohesion force of the adhesive layer obtained will become high too much, and adhesive force may fall. On the other hand, when the content is less than 0.01% by mass, for example, the cohesive force of the obtained pressure-sensitive adhesive layer is reduced, and when peeled from the adherend (protected body), a part of the pressure-sensitive adhesive layer is adhered. May remain contaminated.

  In the preparation (polymerization) of the (meth) acrylic polymer (a), utilizing a curing reaction by heat or radiation using a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator (photoinitiator), An acrylic polymer can be easily formed. In particular, thermal polymerization can be suitably used because of the advantage that the polymerization time can be shortened. A polymerization initiator can be used individually or in combination of 2 or more types.

  Examples of the thermal polymerization initiator include azo polymerization initiators (for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis). (2-methylpropionic acid) dimethyl, 4,4′-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [ 2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (N, N′-di) Methyleneisobutylamidine) dihydrochloride, etc.); peroxide polymerization initiators (for example, dibenzoyl peroxide, t-butylpermaleate, lauro peroxide) Le etc.); redox polymerization initiators, and the like.

  The content of the thermal polymerization initiator is not particularly limited, but is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the total amount of monomer components for preparing the (meth) acrylic polymer (a). More preferably, it is 0.05-3 mass parts.

  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 Active oxime photopolymerization initiator, benzoin photopolymerization initiator, benzyl photopolymerization initiator, benzophenone photopolymerization initiator, ketal photopolymerization initiator, thioxanthone photopolymerization initiator, acylphosphine oxide photopolymerization initiator An initiator or the like can be used.

  Specifically, 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 [trade name: Irgacure 651, manufactured by BASF Corporation], anisole methyl ether and the like can be mentioned. Examples of the acetophenone photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone [trade name: Irgacure 184, manufactured by BASF Corp.], 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1- [4- ( 2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one [trade name: Irgacure 2959, manufactured by BASF Corp.], 2-hydroxy-2-methyl-1-phenyl-propane- 1-one [trade name: Darocur 1173, manufactured by BASF Corporation], methoxyacetophenone, and the like can be given. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) -phenyl] -2-hydroxy-2-methylpropane-1- ON etc. are mentioned. Examples of the aromatic sulfonyl chloride-based photopolymerization initiator include 2-naphthalene sulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime.

  The benzoin photopolymerization initiator includes, for example, benzoin. Examples of the benzyl photopolymerization initiator include benzyl and the like. Examples of the benzophenone-based 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-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone and the like are included.

  Examples of the acylphosphine oxide photopolymerization initiator include bis (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) (2,4,4-trimethylpentyl) phosphine oxide, bis (2,6-dimethoxybenzoyl) -n-butylphosphine oxide, bis (2,6-dimethoxybenzoyl)-(2-methylpropan-1-yl) phosphine oxide, bis (2,6-dimethoxybenzoyl)-(1 -Methylpropan-1-yl) phosphine oxide, bis (2,6-dimethoxybenzoyl) -t-butylphosphine oxide, bis (2,6-dimethoxybenzoyl) cyclohexylphosphine oxide, bis (2,6-dimethoxybenzoyl) octyl Phosphine oxide, (2-methoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2-methoxybenzoyl) (1-methylpropan-1-yl) phosphine oxide, bis (2,6-diethoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2,6-diethoxybenzoyl) (1-methylpropan-1-yl) phosphine oxide, bis (2,6-dibutoxybenzoyl) (2-methyl Propan-1-yl) phosphine oxide, bis (2,4-dimethoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2,4,6-trimethylbenzoyl) (2,4-dipentoxy Phenyl) phosphine oxide, bis (2,6-dimethoxybenzoyl) benzylphosphine oxy Bis (2,6-dimethoxybenzoyl) -2-phenylpropylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylethylphosphine oxide, bis (2,6-dimethoxybenzoyl) benzylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylpropylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylethylphosphine oxide, 2,6-dimethoxybenzoylbenzylbutylphosphine oxide, 2,6-dimethoxybenzoyl Benzyloctylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,5-diisopropylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2-methylphenylphosphineoxy Bis (2,4,6-trimethylbenzoyl) -4-methylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,5-diethylphenylphosphine oxide, bis (2,4,6-trimethyl) Benzoyl) -2,3,5,6-tetramethylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyl Diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) isobutylphosphine oxide, 2,6-dimethoxyoxybenzoyl-2, 4,6-trimethylbenzoyl-n-butylphosphine oxide, bis 2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,4-dibutoxyphenylphosphine oxide, 1,10-bis [bis (2,4,6-trimethyl) Benzoyl) phosphine oxide] decane, tri (2-methylbenzoyl) phosphine oxide, and the like.

  The content of the photopolymerization initiator is not particularly limited, but is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the total amount of monomer components for preparing the (meth) acrylic polymer (a), More preferably, it is 0.05-3 mass parts. Here, when content of the said photoinitiator is less than 0.01 mass part, a polymerization reaction may become inadequate. When the content of the photopolymerization initiator exceeds 5 parts by mass, the photopolymerization initiator may absorb ultraviolet rays, and the ultraviolet rays may not reach the inside of the pressure-sensitive adhesive layer. In this case, the polymerization rate is lowered, or the molecular weight of the produced polymer is reduced. And thereby, the cohesive force of the pressure-sensitive adhesive layer formed becomes low, and when the pressure-sensitive adhesive layer is peeled off from the adherend, a part of the pressure-sensitive adhesive layer remains on the adherend, and the adherend is reused. May not be possible. In addition, a photoinitiator can be used individually or in combination of 2 or more types.

  In the present embodiment, the (meth) acrylic polymer (a) is a partial polymerization in which the monomer component is partially polymerized by irradiating a mixture of the monomer component and the polymerization initiator with radiation (such as ultraviolet rays). It can also be prepared as a product (acrylic polymer syrup). An acrylic polymer syrup is blended with a (meth) acrylic polymer (B), which will be described later, to prepare a pressure-sensitive adhesive composition. After the pressure-sensitive adhesive composition is applied to a predetermined substrate, radiation (such as ultraviolet rays) ) May be irradiated to complete the polymerization.

  Examples of the radiation include ultraviolet (UV), laser beam, α-ray, β-ray, γ-ray, X-ray, and electron beam. Ultraviolet rays are preferable from the viewpoints of controllability, ease of handling, and cost. Used for. More preferably, ultraviolet rays having a wavelength of 200 to 400 nm are used. Ultraviolet rays can be irradiated using an appropriate light source such as a high-pressure mercury lamp, a microwave excitation lamp, or a chemical lamp.

  Furthermore, it is also possible to use a photopolymerization initiation assistant such as amines together with the photopolymerization initiator. Examples of the photopolymerization initiation assistant include 2-dimethylaminoethylbenzoate, dimethylaminoacetophenone, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ester, and the like. These compounds may be used alone or in combination of two or more. It is preferable to mix 0.05-10 mass parts with respect to 100 mass parts of said polymers (A), and, as for photopolymerization start adjuvant, it is more preferable to mix | blend in the range of 0.1-7 mass parts. Within the above range, it is preferable from the viewpoint of easily controlling the polymerization reaction and obtaining an appropriate molecular weight.

In addition, when the photopolymerization initiator is blended, the pressure-sensitive adhesive composition is directly applied on an adherend (protected body) or after being applied to a predetermined coated body such as a separator. Alternatively, the adhesive layer can be obtained by light irradiation after coating on one side of a support (base material) having antistatic properties. Usually, the pressure-sensitive adhesive layer is obtained by irradiating ultraviolet rays having an illuminance of 1 to 200 mW / cm ² at a wavelength of 300 to 400 nm and photopolymerizing them with a light amount of about 200 to 4000 mJ / cm ² .

  The weight average molecular weight (Mw) of the (meth) acrylic polymer (a) is preferably, for example, 30,000 to 5,000,000, more preferably 100,000 to 2,000,000, still more preferably 200,000 to 1,000,000. If the weight average molecular weight (Mw) is too smaller than the above range, the cohesive force of the pressure-sensitive adhesive (layer) may be insufficient, and the chemical solution may easily enter. On the other hand, when the weight average molecular weight (Mw) is too larger than the above range, the fluidity of the pressure-sensitive adhesive is lowered, the wetness to the adherend is insufficient, and the adhesion may be lowered.

  The glass transition temperature (Tg) of the (meth) acrylic polymer (a) is less than 0 ° C., preferably less than −10 ° C., more preferably less than −40 ° C., and usually −80 ℃ or more. When the glass transition temperature (Tg) of the (meth) acrylic polymer (a) is 0 ° C. or higher, the polymer is difficult to flow, wetness to the adherend becomes insufficient, and adhesion may be reduced. . Further, the glass transition temperature (Tg) of the (meth) acrylic polymer (a) is not too low, so that the chemical solution enters (typically, the chemical solution enters mainly due to the pressure-sensitive adhesive swelling). It can contribute to prevention.

  In the present invention, when the (meth) acrylic polymer (a) is a copolymer, its glass transition temperature (Tg) is a value calculated based on the following formula (2) (Fox formula).

_{1 / Tg = W 1 / Tg} 1 + W 2 / Tg 2 + ··· + Wn / Tg n (2)
[In the formula (2), Tg is the glass transition temperature (unit: K) of the copolymer, and Tg _i (i = 1, 2,... N) is the glass transition when the monomer i forms a homopolymer. Temperature (unit: K), W _i (i = 1, 2,... N) represents a mass fraction of all monomer components of monomer i. ]
Further, the glass transition temperature Tgi of the monomer i is a nominal value described in the literature (eg, polymer handbook, adhesive hand log, etc.).

<(Meth) acrylic polymer (B)>
The pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer for chemical treatment according to the present invention has a weight average molecular weight of 1000 or more and less than 30000, and has an alicyclic structure represented by the following general formula (1) (meta It is preferable to contain a (meth) acrylic polymer (B) containing an acrylic monomer as a monomer component.
CH ₂ = C (R ¹ ) COOR ² (1)
[In Formula (1), R ¹ is a hydrogen atom or a methyl group, and R ² is an alicyclic hydrocarbon group having an alicyclic structure. ]

  The (meth) acrylic polymer (B) can exhibit a function as a tackifier resin. Moreover, when the adhesive composition used when forming the chemical | medical solution processing adhesive layer in this invention is an acrylic adhesive composition, it is compatible with the said (meth) acrylic-type polymer (a), for example. It is easy and particularly suitable.

Examples of the alicyclic hydrocarbon group R ² in the general formula (1) include alicyclic hydrocarbon groups such as a cyclohexyl group, an isobornyl group, and a dicyclopentanyl group. Examples of such (meth) acrylic acid ester having an alicyclic hydrocarbon group include cyclohexyl (meth) acrylate having a cyclohexyl group, isobornyl (meth) acrylate having an isobornyl group, and dicyclopentanyl group. Mention may be made of esters of (meth) acrylic acid with alicyclic alcohols such as (meth) acrylic acid dicyclopentanyl. By including the acrylic monomer having a relatively bulky structure as a monomer component in the (meth) acrylic polymer (B), the adhesive strength (adhesive strength) can be improved.

  Furthermore, the alicyclic hydrocarbon group constituting the (meth) acrylic polymer (B) preferably has a bridged ring structure. The bridged ring structure refers to an alicyclic structure having three or more rings. By giving the (meth) acrylic polymer (B) a bulky structure such as a bridged ring structure, the adhesive strength (adhesive strength) of the adhesive layer for chemical treatment (adhesive sheet, surface protective sheet) is further increased. Can be improved.

Examples of R ² that is an alicyclic hydrocarbon group having a bridged ring structure include a dicyclopentanyl group represented by the following formula (3a) and a dicyclopentenyl group represented by the following formula (3b). And adamantyl group represented by the following formula (3c), tricyclopentanyl group represented by the following formula (3d), tricyclopentenyl group represented by the following formula (3e), and the like. In addition, when UV polymerization is employed in the synthesis of the (meth) acrylic polymer (B) or in the preparation of the pressure-sensitive adhesive composition, it is difficult to cause polymerization inhibition. Among (meth) acrylic monomers having a ring or higher alicyclic structure, in particular, a dicyclopentanyl group represented by the following formula (3a), an adamantyl group represented by the following formula (3c), and the following formula A (meth) acrylic monomer having a saturated structure such as a tricyclopentanyl group represented by (3d) can be suitably used as a monomer constituting the (meth) acrylic polymer (B).

  Examples of (meth) acrylic monomers having a tricyclic or higher alicyclic structure having such a bridged ring structure include dicyclopentanyl methacrylate, dicyclopentanyl acrylate, and dicyclopentanyloxyethyl. Methacrylate, dicyclopentanyloxyethyl acrylate, tricyclopentanyl methacrylate, tricyclopentanyl acrylate, 1-adamantyl methacrylate, 1-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate, 2-methyl-2-adamantyl acrylate, (Meth) acrylic acid esters such as 2-ethyl-2-adamantyl methacrylate and 2-ethyl-2-adamantyl acrylate can be mentioned. These (meth) acrylic monomers can be used alone or in combination of two or more.

  The (meth) acrylic polymer (B) may be a homopolymer of a (meth) acrylic monomer having an alicyclic structure, or a (meth) acrylic monomer having an alicyclic structure and others. (Meth) acrylic acid ester monomers or copolymers with copolymerizable monomers.

Examples of such (meth) acrylic acid ester monomers include
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate , T-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, (meth ) Octyl acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, (meth) (Meth) acrylic acid alkyl esters such as dodecyl acrylate;
(Meth) acrylic acid aryl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate;
And (meth) acrylic acid esters obtained from terpene compound derivative alcohols. Such (meth) acrylic acid esters can be used alone or in combination of two or more.

  The (meth) acrylic polymer (B) contains, in addition to the (meth) acrylic acid ester component unit, other monomer components (copolymerizable monomers) copolymerizable with the (meth) acrylic acid ester. It can also be obtained by polymerization.

As other monomers copolymerizable with the (meth) acrylic acid ester,
Carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid;
Alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate monomer;
(Meth) acrylic acid alkali metal salts and the like;
Di (meth) acrylic acid ester of ethylene glycol, di (meth) acrylic acid ester of diethylene glycol, di (meth) acrylic acid ester of triethylene glycol, di (meth) acrylic acid ester of polyethylene glycol, di (meta) of propylene glycol ) Di (meth) acrylate monomers of (poly) alkylene glycols such as acrylate esters, di (meth) acrylate esters of dipropylene glycol, di (meth) acrylate esters of tripropylene glycol;
Polyvalent (meth) acrylate monomers such as trimethylolpropane tri (meth) acrylate;
Vinyl esters such as vinyl acetate and vinyl propionate;
Vinyl halide compounds such as vinylidene chloride and 2-chloroethyl (meth) acrylate;
An oxazoline group-containing polymerizable compound such as 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline;
Aziridine group-containing polymerizable compounds such as (meth) acryloylaziridine, (meth) acrylic acid-2-aziridinylethyl;
Epoxy group-containing vinyl monomers such as allyl glycidyl ether, glycidyl (meth) acrylate, ethyl glycidyl ether (meth) acrylate;
Hydroxyl group-containing vinyl monomers such as (meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-2-hydroxypropyl, adducts of lactones and (meth) acrylic acid-2-hydroxyethyl;
(Meth) acryloyl group at the end of polyalkylene glycol such as polypropylene glycol, polyethylene glycol, polytetramethylene glycol, polybutylene glycol, copolymer of polyethylene glycol and polypropylene glycol, copolymer of polybutylene glycol and polyethylene glycol, A macromonomer to which an unsaturated group such as a styryl group or a vinyl group is bonded;
Fluorine-containing vinyl monomers such as fluorine-substituted (meth) acrylic acid alkyl esters;
Acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride;
Aromatic vinyl compound monomers such as styrene, α-methylstyrene, vinyltoluene;
Reactive halogen-containing vinyl monomers such as 2-chloroethyl vinyl ether and monochloro vinyl acetate;
(Meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N An amide group-containing vinyl monomer such as ethylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-acryloylmorpholine;
Succinimide monomers such as N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyoctamethylene succinimide;
Maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide;
Itaconimides such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide System monomers;
N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N- Vinyloxazole, N- (meth) acryloyl-2-pyrrolidone, N- (meth) acryloylpiperidine, N- (meth) acryloylpyrrolidine, N-vinylmorpholine, N-vinylpyrazole, N-vinylisoxazole, N-vinylthiazole Nitrogen-containing heterocyclic monomers such as N-vinylisothiazole and N-vinylpyridazine;
N-vinylcarboxylic acid amides;
Lactam monomers such as N-vinylcaprolactam;
Cyano group-containing monomers such as (meth) acrylonitrile;
(Meth) acrylic such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate Acid aminoalkyl monomers;
Imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide;
Isocyanate group-containing monomers such as 2-isocyanatoethyl (meth) acrylate;
Organosilicon-containing vinyl monomers such as vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine, 2-methoxyethoxytrimethoxysilane;
Hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, hydroxydecyl (meth) acrylate, (meta ) Hydroxyl group-containing monomers such as hydroxyalkyl (meth) acrylate such as hydroxylauryl acrylate, (4-hydroxymethylcyclohexyl) methyl methacrylate;
(Meth) acrylic acid tetrahydrofurfuryl, fluorine atom-containing (meth) acrylate, silicone (meth) acrylate and other heterocyclic rings, halogen atoms, silicon atoms and the like, acrylic ester monomers;
Olefin monomers such as isoprene, butadiene, isobutylene;
Vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether;
Olefins or dienes such as ethylene, butadiene, isoprene, isobutylene;
Vinyl ethers such as vinyl alkyl ethers;
Vinyl chloride;
Other examples include macromonomers having a radical polymerizable vinyl group at the terminal of a monomer obtained by polymerizing a vinyl group. These monomers can be copolymerized with the (meth) acrylic acid ester alone or in combination.

  Examples of the (meth) acrylic polymer (B) include a copolymer of cyclohexyl methacrylate (CHMA) and isobutyl methacrylate (IBMA), a copolymer of cyclohexyl methacrylate (CHMA) and isobornyl methacrylate (IBXMA), A copolymer of methyl methacrylate (MMA) and isobornyl methacrylate (IBXMA), a copolymer of cyclohexyl methacrylate (CHMA) and acryloylmorpholine (ACMO), a copolymer of cyclohexyl methacrylate (CHMA) and diethylacrylamide (DEAA), 1-adamantyl acrylate (ADA) and methyl methacrylate (MMA) copolymer, dicyclopentanyl methacrylate (DCPMA) and isobornyl methacrylate (IBXMA) Copolymer, dicyclopentanyl methacrylate (DCPMA) and methyl methacrylate (MMA) copolymer, cyclohexyl methacrylate (CHMA) and methyl methacrylate (MMA) copolymer, dicyclopentanyl methacrylate (DCPMA) and acrylic Copolymer of acid (AA), dicyclopentanyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate (IBXA), dicyclopentanyl acrylate (DCPA), 1 -Adamantyl methacrylate (ADMA), 1-adamantyl acrylate (ADA) homopolymers, and the like.

  Furthermore, in the (meth) acrylic polymer (B), a functional group having reactivity with an epoxy group or an isocyanate group may be introduced. Examples of such functional groups / BR> include hydroxyl groups, carboxyl groups, amino groups, amide groups, and mercapto groups, and these functional groups are used in the production of the (meth) acrylic polymer (B). A monomer having a group may be used (copolymerization).

  When the (meth) acrylic polymer (B) is a copolymer of a (meth) acrylic monomer having an alicyclic structure and another (meth) acrylic acid ester monomer or a copolymerizable monomer, The content ratio of the (meth) acrylic monomer having a cyclic structure is preferably 5% by mass or more, more preferably 10% in the total amount of monomer components (100% by mass) constituting the (meth) acrylic polymer (B). It is at least mass%, more preferably at least 20 mass%, particularly preferably at least 30 mass% (usually less than 100 mass%, preferably at most 90 mass%). Adhesive strength (adhesive strength) can be improved by containing 5% by mass or more of a (meth) acrylic monomer having an alicyclic structure. Moreover, by including the (meth) acrylic monomer having the alicyclic structure, appropriate phase separation between the (meth) acrylic polymer (B) and the compound (D) having a polyoxyalkylene chain can be achieved. The mobility of the ionic compound (C) that occurs and is carried by the polyoxyalkylene chain is improved by the (meth) acrylic polymer (B), and as a result, an improvement in antistatic performance can be achieved. On the other hand, if it is less than 5% by mass, the adhesion may be inferior.

  The (meth) acrylic polymer (B) has a weight average molecular weight (Mw) of preferably 1000 or more and less than 30000, more preferably 1500 or more and less than 20000, and still more preferably 2000 or more and less than 10,000. Adhesive strength (adhesive force) falls that a weight average molecular weight is 30000 or more. Further, if the weight average molecular weight is less than 1000, the adherend may be contaminated due to low molecular weight.

  The weight average molecular weight (Mw) of the polymer (A) ((meth) acrylic polymer (a)) or the (meth) acrylic polymer (B) is measured by a gel permeation chromatography (GPC) method using polystyrene. It can be obtained by conversion. Specifically, it is measured according to the method and conditions described in the examples described later.

  The (meth) acrylic polymer (B) preferably has a glass transition temperature (Tg) of 0 to 300 ° C, more preferably 50 ° C to 280 ° C, still more preferably 90 ° C to 280 ° C, and particularly preferably 110 ° C. ~ 250 ° C. If the glass transition temperature (Tg) of the (meth) acrylic polymer (B) is less than 0 ° C., sufficient adhesive strength (adhesive strength) may not be obtained. If it is 300 ° C. or higher, the cohesive force of the pressure-sensitive adhesive layer becomes too high, so that the wettability to the adherend may be insufficient, which is not preferable. Table 1 below shows glass transition temperatures (Tg) of typical materials that can be used as the (meth) acrylic polymer (B) in the present embodiment. The glass transition temperature (Tg) shown in Table 1 is a nominal value described in literatures, catalogs, or the like, or a value calculated based on the following formula (3) (Fox formula).

_{1 / Tg = W 1 / Tg} 1 + W 2 / Tg 2 + ··· + Wn / Tg n (3)
[In the formula (3), Tg is the glass transition temperature (unit: K) of the (meth) acrylic polymer (B), and Tg _i (i = 1, 2,... N) is the monomer i is a homopolymer. When formed, the glass transition temperature (unit: K), W _i (i = 1, 2,... N) represents the mass fraction of all monomer components of monomer i. ]
The formula (3) is a calculation formula in the case where the (meth) acrylic polymer (B) is composed of n types of monomer components of monomer 1, monomer 2,.

Abbreviations in Table 1 indicate the following compounds.
DCPMA: dicyclopentanyl methacrylate DCPA: dicyclopentanyl acrylate IBXMA: isobornyl methacrylate IBXA: isobornyl acrylate CHMA: cyclohexyl methacrylate CHA: cyclohexyl acrylate IBMA: isobutyl methacrylate MMA: methyl methacrylate ADMA: 1-adamantyl methacrylate ADA: 1-adamantyl acrylate

  Although content in particular of the said (meth) acrylic-type polymer (B) is not restrict | limited, For example, 0.005-2 mass parts is preferable with respect to 100 mass parts of said polymers (A), More preferably, it is 0.00. It is 01-1.5 mass parts, More preferably, it is 0.05-0.5 mass part. When the amount of the (meth) acrylic polymer (B) exceeds 2.0 parts by mass, the antistatic property of the pressure-sensitive adhesive layer may be deteriorated. When the amount is less than 0.005 parts by mass, the adhesive strength (adhesion) Force) may not be obtained, which is not preferable.

  The (meth) acrylic polymer (B) is obtained by subjecting the (meth) acrylic monomer having the above-described structure to solution polymerization, emulsion polymerization, bulk polymerization, as in the case of the (meth) acrylic polymer (a). Various polymerization methods generally used can be applied using suspension polymerization, radiation curing polymerization, or the like as a synthesis method.

  In order to adjust the weight average molecular weight (Mw) of the (meth) acrylic polymer (B), a chain transfer agent can be used during the polymerization. Examples of the chain transfer agent used include compounds having a mercapto group such as octyl mercaptan, lauryl mercaptan, t-dodecyl mercaptan, mercaptoethanol, α-thioglycerol; thioglycolic acid, methyl thioglycolate, ethyl thioglycolate, Propyl thioglycolate, butyl thioglycolate, t-butyl thioglycolate, 2-ethylhexyl thioglycolate, octyl thioglycolate, decyl thioglycolate, dodecyl thioglycolate, thioglycolate of ethylene glycol, neopentyl glycol And thioglycolic acid esters such as pentaerythritol thioglycolic acid ester; α-methylstyrene dimer and the like.

  The content of the chain transfer agent is not particularly limited, but usually the chain transfer agent is used with respect to 100 parts by mass of the total amount of the (meth) acrylic monomer constituting the (meth) acrylic polymer (B). It is preferable to contain 0.1-20 mass parts, More preferably, it is 0.2-15 mass parts, More preferably, it is 0.3-10 mass parts. Thus, the (meth) acrylic-type polymer (B) of a suitable molecular weight can be obtained by adjusting the addition amount of a chain transfer agent. In addition, a chain transfer agent can be used individually or in combination of 2 or more types.

<Ionic compound (C)>
In the pressure-sensitive adhesive layer for chemical treatment according to the present invention, the pressure-sensitive adhesive composition preferably contains an ionic compound (C), and the ionic compound (C) is an alkali metal salt and / or an ionic liquid. It is more preferable. The ionic compound is a compound that exhibits ion dissociation properties at room temperature, and can contain excellent antistatic properties by containing the ionic compound. Among them, the alkali metal salt has a high ion dissociation property even in a very small content (blending amount), and thus can exhibit excellent antistatic ability while suppressing contamination of the adherend. Is useful. Moreover, since the said ionic liquid shows the electroconductivity outstanding by itself, it can provide sufficient antistatic ability only by containing a trace amount in an adhesive layer, and is useful.

<Alkali metal salt>
Examples of the alkali metal salt include a cation composed of Li ⁺ , Na ⁺ , K ⁺ , Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , SCN. _{^{-, ClO 4 -, NO 3}} -, CH 3 COO -, C 9 H 19 COO -, CF 3 COO -, C 3 F 7 COO -, CH 3 SO 3 -, CF 3 SO 3 -, C 4 F 9 SO ₃ ⁻ , C ₂ H ₅ OSO ₃ ⁻ , C ₆ H ₁₃ OSO ₃ ⁻ , C ₈ H ₁₇ OSO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , (C ₃ F ₇ SO ₂ ) ₂ N ⁻ , (C ₄ F ₉ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , NbF ₆ ⁻ , TaF ₆ ⁻ , ^{_{F (HF) n -, (}} CN) _{^{N -, (CF 3 SO 2}} ) (CF 3 CO) N -, (CH 3) 2 PO 4 -, (C 2 H 5) 2 PO 4 -, CH 3 (OC 2 H 4) 2 OSO 3 -, Metal salt composed of an anion consisting of C ₆ H ₄ (CH ₃ ) SO ₃ ⁻ , (C ₂ F ₅ ) ₃ PF ₃ ⁻ , CH ₃ CH (OH) COO ⁻ , and (FSO ₂ ) ₂ N ^−. Are preferably used. More _{preferably, LiBr, LiI, LiBF 4,} LiPF 6, LiSCN, LiClO 4, LiCF 3 SO 3, Li (CF 3 SO 2) 2 N, Li (C 2 F 5 SO 2) 2 N, Li (FSO 2 ) ₂ N, lithium salts such as Li (CF ₃ SO ₂ ) ₃ C, more preferably LiClO ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) _{2 N, Li (C 3 F} 7 SO 2) 2 N, Li (C 4 F 9 SO 2) 2 N, Li (FSO 2) 2 N, Li (CF 3 SO 2) 3 C is used. These alkali metal salts may be used alone or in combination of two or more.

<Ionic liquid>
The ionic liquid refers to a liquid (liquid) in a range of 0 to 150 ° C. and a non-volatile molten salt. Since the ionic liquid is liquid in any of the above ranges, it can be easily added and dispersed or dissolved in the pressure-sensitive adhesive as compared with a solid salt. Furthermore, since the ionic liquid has no vapor pressure (non-volatile), it does not disappear with time, and the antistatic property can be continuously obtained.

  Further, by using the ionic liquid as an antistatic agent, a pressure-sensitive adhesive layer having a high antistatic effect can be obtained without impairing adhesive (adhesive) characteristics. Although details of the reason why excellent antistatic properties can be obtained by using ionic liquids are not clear, ionic liquids have a low melting point (melting point of 150 ° C. or lower) compared to ordinary ionic compounds, so molecular movement is easy. It is considered that excellent antistatic ability can be obtained. In particular, when antistatic is applied to the adherend, it is considered that an excellent peeling antistatic property on the adherend can be achieved by transferring a very small amount of the ionic liquid to the adherend. In particular, since an ionic liquid having a melting point of room temperature (25 ° C.) or less can be transferred to an adherend more efficiently, excellent antistatic properties can be obtained.

  The ionic liquid is preferably a nitrogen-containing onium salt, a sulfur-containing onium salt, or a phosphorus-containing onium salt, and more preferably an organic cation component represented by the following general formulas (C1) to (C5) And those consisting of an anionic component are preferably used. An ionic liquid having these cations provides a further excellent antistatic ability.

R _a in the formula (C1) represents a hydrocarbon group having 4 to 20 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom, and R _b and R _c May be the same or different and each represents hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and a part of the hydrocarbon group may be a functional group substituted with a hetero atom. However, when the nitrogen atom contains a double bond, there is no R _c .

R _d in the formula (C2) represents a hydrocarbon group having 2 to 20 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom, and R _e , R _f And R _g may be the same or different and each represents hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and a part of the hydrocarbon group may be a functional group substituted with a hetero atom.

R _h in the formula (C3) represents a hydrocarbon group having 2 to 20 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom, R _i , R _j , And R _k may be the same or different and each represents hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and a part of the hydrocarbon group may be a functional group substituted with a hetero atom.

Z in the formula (C4) represents a nitrogen, sulfur, or phosphorus atom, and R ₁ , R _m , R _n , and R _o are the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms. In addition, a functional group in which a part of the hydrocarbon group is substituted with a hetero atom may be used. However, when Z is a sulfur atom, there is no _Ro .

R _P of the formula (C5) represents a hydrocarbon group having 1 to 18 carbon atoms, a part of the hydrocarbon group may be substituted by a functional group with a heteroatom.

  Examples of the cation represented by the formula (C1) include a pyridinium cation, a piperidinium cation, a pyrrolidinium cation, a cation having a pyrroline skeleton, a cation having a pyrrole skeleton, and a morpholinium cation.

  Specific examples include, for example, 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-hexyl. -3-methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation, 1,1-dimethylpyrrolidinium cation, 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidi Cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium Cation, 1-ethyl-1-propylpyrrolidini Cation, 1-ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation, 1-ethyl-1-heptylpyrrolidinium Cation, 1,1-dipropylpyrrolidinium cation, 1-propyl-1-butylpyrrolidinium cation, 1,1-dibutylpyrrolidinium cation, pyrrolidinium-2-one cation, 1-propylpiperidinium cation, 1-pentylpiperidinium cation, 1,1-dimethylpiperidinium cation, 1-methyl-1-ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpi Peridinium cation, 1-methyl-1-pentylpiperidinium cation 1-methyl-1-hexylpiperidinium cation, 1-methyl-1-heptylpiperidinium cation, 1-ethyl-1-propylpiperidinium cation, 1-ethyl-1-butylpiperidinium cation, 1 -Ethyl-1-pentylpiperidinium cation, 1-ethyl-1-hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, 1,1-dipropylpiperidinium cation, 1-propyl -1-butylpiperidinium cation, 1,1-dibutylpiperidinium cation, 2-methyl-1-pyrroline cation, 1-ethyl-2-phenylindole cation, 1,2-dimethylindole cation, 1-ethylcarbazole Cations, N-ethyl-N-methylmorpholinium cations, etc. It is done.

  Examples of the cation represented by the formula (C2) include an imidazolium cation, a tetrahydropyrimidinium cation, and a dihydropyrimidinium cation.

  Specific examples include, for example, 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, and 1-helium. Xyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, 1-tetradecyl-3-methylimidazole Cation, 1,2-dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, 1-hexyl-2,3 -Dimethylimidazolium cation, 1- (2-metho (Ciethyl) -3-methylimidazolium cation, 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3-trimethyl-1,4,5,6-tetrahydropyrimidinium Cation, 1,2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,5-tetramethyl-1,4,5,6-tetrahydropyrimidinium Cation, 1,3-dimethyl-1,4-dihydropyrimidinium cation, 1,3-dimethyl-1,6-dihydropyrimidinium cation, 1,2,3-trimethyl-1,4-dihydropyrimidinium Cation, 1,2,3-trimethyl-1,6-dihydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4-dihydropyrimidinium kathi Emissions, such as 1,2,3,4-tetramethyl-1,6-dihydropyrimidinium cation.

  Examples of the cation represented by the formula (C3) include a pyrazolium cation and a pyrazolinium cation.

  Specific examples include, for example, 1-methylpyrazolium cation, 3-methylpyrazolium cation, 1-ethyl-2-methylpyrazolinium cation, 1-ethyl-2,3,5-trimethylpyrazolium cation. 1-propyl-2,3,5-trimethylpyrazolium cation, 1-butyl-2,3,5-trimethylpyrazolium cation, 1-ethyl-2,3,5-trimethylpyrazolinium cation, 1 -Propyl-2,3,5-trimethylpyrazolinium cation, 1-butyl-2,3,5-trimethylpyrazolinium cation and the like.

  Examples of the cation represented by the formula (C4) include a tetraalkylammonium cation, a trialkylsulfonium cation, a tetraalkylphosphonium cation, and a part of the alkyl group is substituted with an alkenyl group, an alkoxyl group, or an epoxy group. And so on.

  Specific examples include, for example, tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, trimethylsulfonium cation, triethylsulfonium cation, tributylsulfonium cation, trihexylsulfonium cation, diethylmethylsulfonium cation, dibutyl Ethylsulfonium Kachi , Dimethyldecylsulfonium cation, tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetrahexylphosphonium cation, tetraoctylphosphonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, trimethyldecylphosphonium cation, diallyldimethylammonium cation And tributyl- (2-methoxyethyl) phosphonium cation. Among them, asymmetric such as triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, trimethyldecylphosphonium cation, etc. Tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylphosphonium cation, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium cation, N, N -Dimethyl-N-ethyl-N-propyla Monium cation, N, N-dimethyl-N-ethyl-N-butylammonium cation, N, N-dimethyl-N-ethyl-N-pentylammonium cation, N, N-dimethyl-N-ethyl-N-hexylammonium cation N, N-dimethyl-N-ethyl-N-heptylammonium cation, N, N-dimethyl-N-ethyl-N-nonylammonium cation, N, N-dimethyl-N, N-dipropylammonium cation, N, N-diethyl-N-propyl-N-butylammonium cation, N, N-dimethyl-N-propyl-N-pentylammonium cation, N, N-dimethyl-N-propyl-N-hexylammonium cation, N, N- Dimethyl-N-propyl-N-heptylammonium cation, N, N-di Tyl-N-butyl-N-hexylammonium cation, N, N-diethyl-N-butyl-N-heptylammonium cation, N, N-dimethyl-N-pentyl-N-hexylammonium cation, N, N-dimethyl- N, N-dihexylammonium cation, trimethylheptylammonium cation, N, N-diethyl-N-methyl-N-propylammonium cation, N, N-diethyl-N-methyl-N-pentylammonium cation, N, N-diethyl -N-methyl-N-heptylammonium cation, N, N-diethyl-N-propyl-N-pentylammonium cation, triethylpropylammonium cation, triethylpentylammonium cation, triethylheptylammonium cation, N, N- Dipropyl-N-methyl-N-ethylammonium cation, N, N-dipropyl-N-methyl-N-pentylammonium cation, N, N-dipropyl-N-butyl-N-hexylammonium cation, N, N-dipropyl- N, N-dihexylammonium cation, N, N-dibutyl-N-methyl-N-pentylammonium cation, N, N-dibutyl-N-methyl-N-hexylammonium cation, trioctylmethylammonium cation, N-methyl- N-ethyl-N-propyl-N-pentylammonium cation is preferably used.

Examples of the cation represented by the formula (C5) include a sulfonium cation. Further, the formula Specific examples of R _P in (E) is a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, An octadecyl group etc. are mentioned.

On the other hand, the anion component is not particularly limited as long as it satisfies that it becomes an ionic liquid. For example, Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF _{^{6 -, SCN -, ClO 4}} -, NO 3 -, CH 3 COO -, CF 3 COO -, CH 3 SO 3 -, CF 3 SO 3 -, C 4 F 9 SO 3 -, (CF 3 SO 2) _{^{2 N -, (C 2 F}} 5 SO 2) 2 N -, (C 3 F 7 SO 2) 2 N -, (C 4 F 9 SO 2) 2 N -, (CF 3 SO 2) 3 C -, AsF ₆ ⁻ , SbF ₆ ⁻ , NbF ₆ ⁻ , TaF ₆ ⁻ , F (HF) _n ⁻ , (CN) ₂ N ⁻ , C ₄ F ₉ SO ₃ ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , _{^{C 3 F 7 COO -, (}} CF 3 SO 2) (CF _{^{3 CO) N -, C 9}} H 19 COO -, (CH 3) 2 PO 4 -, (C 2 H 5) 2 PO 4 -, CH 3 OSO 3 -, C 2 H 5 OSO 3 -, C 4 H ₉ OSO ₃ ⁻ , C ₆ H ₁₃ OSO ₃ ⁻ , C ₈ H ₁₇ OSO ₃ ⁻ , CH ₃ (OC ₂ H ₄ ) ₂ OSO ₃ ⁻ , C ₆ H ₄ (CH ₃ ) SO ₃ ⁻ , (C ₂ F ₅ ) ₃ PF ₃ ⁻ , CH ₃ CH (OH) COO ⁻ , (FSO ₂ ) ₂ N ⁻ , B (CN) ₄ ⁻ , C (CN) ₃ ⁻ , N (CN) ₂ ⁻ , p-toluenesulfonate anion 2- (2-methoxyethyl) ethyl sulfate anion or the like can be used. In particular, an anionic component containing a fluorine atom is an ion that has a low melting point ionic liquid and has excellent compatibility with (meth) acrylic polymer (a) and (meth) acrylic polymer (B). It is preferably used because a liquid is obtained.

  Moreover, as an anion component, the anion etc. which are represented by a following formula (C6) can also be used.

［式（Ｃ６）中のＲ_１〜Ｒ_４は、それぞれ独立に、水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアルケニル基、置換基を有してもよいアルキニル基、置換基を有してもよいアリール基、及び、置換基を有してもよい複素環基を表わす。前記置換基の水素原子は、更に他の置換基（電子吸引性基の置換基等）に置換されていても構わない。]

[R _{1 to} R ₄ in Formula (C6) may each independently have a hydrogen atom, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, or a substituent. A good alkynyl group, an aryl group which may have a substituent, and a heterocyclic group which may have a substituent are represented. The hydrogen atom of the substituent may be further substituted with another substituent (such as a substituent of an electron-withdrawing group). ]

Moreover, as an anion component, the anion etc. which are represented with a following formula (C7) can also be used.

  As the anion component, in particular, an anion component containing a fluorine atom can be used to obtain an ionic liquid having a low melting point, a (meth) acrylic polymer (a), a (meth) acrylic polymer (B), or the like. It is preferably used because an ionic liquid excellent in compatibility can be obtained.

Specific examples of the ionic liquid used in the present invention are appropriately selected from a combination of the cation component and the anion component. For example, 1-butylpyridinium tetrafluoroborate, 1-butylpyridinium hexafluorophosphate, 1-butyl -3-methylpyridinium tetrafluoroborate, 1-butyl-3-methylpyridinium trifluoromethanesulfonate, 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide, 1-butyl-3-methylpyridinium bis (pentafluoroethane Sulfonyl) imide, 1-hexylpyridinium tetrafluoroborate, 1,1-dimethylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-ethylpyrrolidinium bis ( Trifluoromethanesulfonyl) imide, 1-methyl-1-propylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-pentyl Pyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-hexylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-heptylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1 -Ethyl-1-propylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-pentylpyrrolidinium bis (trifluorome Sulfonyl) imide, 1-ethyl-1-hexylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-heptylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1,1-dipropylpyrrole Dinium bis (triple olomethanesulfonyl) imide, 1-propyl-1-butylpyrrolidinium bis (trifluoromethanesulfonyl) imide, 1,1-dibutylpyrrolidinium bis (triple methanesulfonyl) imide, 1-propylpi Peridinium bis (trifluoromethanesulfonyl) imide, 1-pentylbiberidinium bis (trifluoromethanesulfonyl) imide, 1,1-dimethylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-ethylpiperidi Niu Mubis (trifluoromethanesulfonyl) imide, 1-methyl-1-propylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-butylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1- Pentylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-hexylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-methyl-1-heptylpiperidinium bis (trifluoromethanesulfonyl) imide, 1 -Ethyl-1-propylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-butylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-pentylpiperidinium bis (trif Olomethanesulfonyl) imide, 1-ethyl-1-hexylpiperidinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-1-heptylpiperidinium bis (trifluoromethanesulfonyl) imide, 1,1-dipropyl Piperidinium bis (trifluoromethanesulfonyl) imide, 1-propyl-1-butylpiperidiniumpis (trifluoromethanesulfonyl) imide, 1,1-dibutylpiperidinium bis (trifluoromethanesulfonyl) imide, 1,1-dimethyl Pyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-ethylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-propylpyrrolidinium bis (pentafluoroethanesulfonyl) imi 1-methyl-1-butylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-pentylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-hexylpyrrolidinium Bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-heptylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-propylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1- Ethyl-1-butylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-pentylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-hexylpyrrolidinium bis (penta Fluoroethanesulfonyl) imi 1-ethyl-1-heptylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1,1-dipropylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-propyl-1-butylpyrrolidinium Bis (pentafluoroethanesulfonyl) imide, 1,1-dibutylpyrrolidinium bis (pentafluoroethanesulfonyl) imide, 1-propylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-pentylpiperidinium bis (venta) Fluoroethanesulfonyl) imide, 1,1-dimethylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-ethylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-propylpi Peridinium (Pentafluoroethanesulfonyl) imide, 1-methyl-1-butylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-pentylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl -1-hexylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-methyl-1-heptylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-propylpiperidinium bis (penta Fluoroethanesulfonyl) imide, 1-ethyl-1-butylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-pentylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1- Hexyl piperidinium Bis (pentafluoroethanesulfonyl) imide, 1-ethyl-1-heptylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1,1-dipropylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1-propyl -1-butylpiperidinium bis (pentafluoroethanesulfonyl) imide, 1,1-dibutylpiperidinium bis (pentafluoroethanesulfonyl) imide, 2-methyl-1-pyrroline tetrafluoroborate, 1-ethyl-2- Phenylindole tetrafluoroborate, 1,2-dimethylindole tetrafluoroborate, 1-ethylcarbazole tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium Acetate, 1-ethyl-3-methylimidazolium trifluoroacetate, 1-ethyl-3-methylimidazolium heptafluorobutyrate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazole 1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-ethyl-3-methylimidazolium bis (pentafluoroethanesulfonyl), 1-ethyl-3-methylimidazolium dicyanamide Imido, 1-ethyl-3-methylimidazolium tris (trifluoromethanesulfonyl) methide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexa Fluorophosphate, 1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl-3-methylimidazolium heptafluorobutyrate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3- Methylimidazolium perfluorobutanesulfonate, 1-butyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, 1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium chloride, 1- Hexyl-3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate, 1-octyl -3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-2,3-dimethylimidazolium tetrafluoroborate, 1,2-dimethyl-3-propylimidazolium Bis (trifluoromethanesulfonyl) imide, 1-methylpyrazolium tetrafluoroborate, 2-methylpyrazolium tetrafluoroporate, 1-ethyl-2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) imide, 1-propyl-2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) imide, 1-butyl-2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) imide, 1-ethyl-2, 3,5-trimmer Tylpyrazolium bis (pentafluoroethanesulfonyl) imide, 1-propyl-2,3,5-trimethylpyrazolium bis (pentafluoroethanesulfonyl) imide, 1-butyl-2,3,5-trimethylpyrazolium Bis (pentafluoroethanesulfonyl) imide, 1-ethyl-2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) trifluoroacetamide, 1-propyl-2,3,5-trimethylpyrazolium bis (trifluoro) (Romethanesulfonyl) trifluoroacetamide, 1-butyl-2,3,5-trimethylpyrazolium bis (trifluoromethanesulfonyl) trifluoroacetamide, 1-ethyl-2,3,5-trimethylpyrazolinium bis (trifluoromethanesulfonyl ) Imide, -Propyl-2,3,5-trimethylpyrazolinium bis (trifluoromethanesulfonyl) imide, 1-butyl-2,3,5-trimethylpyrazolinium bis (trifluoromethanesulfonyl) imide, 1-ethyl-2,3 , 5-trimethylpyrazolinium bis (pentafluoroethanesulfonyl) imide, 1-propyl-2,3,5-trimethylpyrazolinium bis (pentafluoroethanesulfonyl) imide, 1-butyl-2,3,5-trimethyl Pyrazolinium bis (pentafluoroethanesulfonyl) imide, 1-ethyl-2,3,5-trimethylpyrazolinium bis (trifluoromethanesulfonyl) trifluoroacetamide, 1-propyl-2,3,5-trimethylpyrazolinium Bis (trifluoromethanesulfonyl) Trifluoroacetamide, 1-butyl-2,3,5-trimethylpyrazolinium bis (trifluoromethanesulfonyl) trifluoroacetamide, tetrapentylammonium trifluoromethanesulfonate, tetrapentylammonium bis (trifluoromethanesulfonyl) imide, tetrahexylammonium trifluoro Lomethanesulfonate, tetrahexylammonium bis (trifluoromethanesulfonyl) imide, tetrahebutylammonium trifluoromethanesulfonate, tetraheptylammonium bis (trifluoromethanesulfonyl) imide, diallyldimethylammonium tetrafluoroborate, diallyldimethylammonium trifluoromethanesulfonate, diallyldimethylammonium Screw Trifluoromethanesulfonyl) imide, diallyldimethylammonium bis (pentafluoroethanesulfonyl) imide, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium tetrafluoroborate, N, N-diethyl-N- Methyl-N- (2
-Methoxyethyl) ammonium trifluoromethanesulfonate, N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-Nmethyl-N- (2- Methoxyethyl) ammonium bis (pentafluoroethanesulfonyl) imide, glycidyltrimethylammonium trifluoromethanesulfonate, glycidyltrimethylammonium bis (trifluoromethanesulfonyl) imide, glycidyltrimethylammonium bis (pentafluoroethanesulfonyl) imide, tetraoctylphosphonium trifluoromethanesulfonate, Tetraoctylphosphonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-propyl Propylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-butylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-pentylammonium bis (trifluoro) Romethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-ethyl-N-nonylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N, N-dipropylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N -Propi Ru-N-butylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-hexylammonium Bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-propyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-butyl-N-hexylammonium bis (trifluoromethanesulfonyl) Imide, N, N-dimethyl-N-butyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-pentyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, , N-dimethyl-N, N-dihexylammonium bis (trifluoromethanesulfonyl) imide, trimethylheptylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-propylammonium bis (trifluoromethanesulfonyl) Imido, N, N-diethyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-diethyl-N-methyl-N-heptylammonium bis (trifluoromethanesulfonyl) imide, N, N- Diethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, triethylpropylammonium bis (trifluoromethanesulfonyl) imide, triethylpentylammonium vinyl (Trifluoromethanesulfonyl) imide, triethylheptylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-methyl-N-ethylammonium bis (trifluoromedansulfonyl) imide, N, N-dipropyl-N-methyl -N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N-butyl-N-hexylammonium bis (trifluoromethanesulfonyl) imide, N, N-dipropyl-N, N-dihexylammonium bis ( Trifluoromethanesulfonyl) imide, N, N-dibutyl-N-methyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, N, N-dibutyl-N-methyl-N-hexylammonium bis (t Trifluoromethanesulfonyl) imide, trioctylmethylammonium bis (trifluoromethanesulfonyl) imide, N-methyl-N-ethyl-N-propyl-N-pentylammonium bis (trifluoromethanesulfonyl) imide, 1-butylpyridinium (trifluoromethane) Sulfonyl) trifluoroacetamide, 1-butyl-3-methylpyridinium (trifluoromethanesulfonyl) trifluoroacetamide, 1-ethyl-3-methylimidazolium (trifluoromethanesulfonyl) trifluoroacetamide, N-ethyl-N-methylmorpholine Examples thereof include nium thiocyanate and 4-ethyl-4-methylmorpholinium methyl carbonate.

  A commercially available ionic liquid as described above may be used, but it can also be synthesized as follows. The method of synthesizing the ionic liquid is not particularly limited as long as the target ionic liquid can be obtained. In general, however, it is described in the document “Ionic liquids—the forefront and future of development” [CMC Publishing Co., Ltd.] As described, a halide method, a hydroxide method, an acid ester method, a complex formation method, a neutralization method, and the like are used.

  The synthesis method of the halide method, hydroxide method, acid ester method, complex formation method, and neutralization method will be described below using a nitrogen-containing onium salt as an example. Other sulfur-containing onium salts, phosphorus-containing onium salts, etc. This ionic liquid can also be obtained by the same method.

The halide method is a method carried out by reactions as shown in the following formulas (1) to (3). First, a tertiary amine and an alkyl halide are reacted to obtain a halide. (Reaction formula (1), chlorine, bromine and iodine are used as the halogen) Acid (HA) or salt (MA, M having the anionic structure (A ⁻ ) of the ionic liquid intended for the obtained halide A target ionic liquid (R ₄ NA) is obtained by reacting with a target anion such as ammonium, lithium, sodium, potassium and the like to form a salt.

The hydroxide method is a method performed by reactions as shown in (4) to (8). First, halide (R ₄ NX) is subjected to ion exchange membrane electrolysis (reaction formula (4)), OH type ion exchange resin method (reaction formula (5)) or reaction with silver oxide (Ag ₂ O) (reaction formula ( 6)) to obtain the hydroxide (R ₄ NOH). (Chlorine, bromine and iodine are used as the halogen) The obtained hydroxide is subjected to the reaction of the reaction formulas (7) to (8) in the same manner as the halogenation method, and the target ionic liquid (R ₄ NA ) Is obtained.

The acid ester method is a method performed by reactions as shown in (9) to (11). First, a tertiary amine (R ₃ N) is reacted with an acid ester to obtain an acid ester product. (Reaction formula (9), as the acid ester, an ester of an inorganic acid such as sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid or carbonic acid, or an organic acid such as methanesulfonic acid, methylphosphonic acid or formic acid) The target ionic liquid (R ₄ NA) is obtained from the obtained acid ester using the reactions of the reaction formulas (10) to (11) in the same manner as in the halogenation method. Further, by using methyl trifluoromethanesulfonate, methyl trifluoroacetate or the like as the acid ester, an ionic liquid can be obtained directly.

The complex formation method is a method performed by reactions as shown in (12) to (15). First, a quaternary ammonium halide (R ₄ NX), a quaternary ammonium hydroxide (R ₄ NOH), a quaternary ammonium carbonate ester (R ₄ NOCO ₂ CH ₃ ) or the like is added to hydrogen fluoride (HF) or Reaction with ammonium fluoride (NH ₄ F) gives a quaternary ammonium fluoride salt. (Reaction formulas (12) to (14)) The obtained quaternary ammonium fluoride salt is complexed with a fluoride such as BF ₃ , AlF ₃ , PF ₅ , AsF ₅ , SbF ₅ , NbF ₅ , TaF _5. An ionic liquid can be obtained. (Reaction Formula (15))

The neutralization method is a method performed by a reaction as shown in (16). Tertiary amine and HBF ₄ , HPF ₆ , CH ₃ COOH, CF ₃ COOH, CF ₃ SO ₃ H, (CF ₃ SO ₂ ) ₂ NH, (CF ₃ SO ₂ ) ₃ CH, (C ₂ F ₅ SO ₂ ) ₂ It can be obtained by reacting with an organic acid such as NH.

  R in the formulas (1) to (16) represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, and a part of the hydrocarbon group may be a functional group substituted with a hetero atom. Good.

  In addition, the said ionic liquid may be used independently and may mix and use 2 or more types.

  Further, the content of the ionic compound (C) is not particularly limited, but is preferably 0.005 to 2 parts by mass with respect to 100 parts by mass of the polymer (A), for example, 0.01 to 1.5 mass parts is more preferable, 0.05-1 mass part is still more preferable, Most preferably, it is 0.07-0.8 mass part. Within the above range, the resulting pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet) can exhibit excellent adhesive strength (adhesive strength) and antistatic properties, which is useful.

<Compound (D) having a polyoxyalkylene chain>
The pressure-sensitive adhesive layer for chemical liquid treatment of the present invention is not particularly limited as long as the pressure-sensitive adhesive composition contains the compound (D) having a polyoxyalkylene chain, and is a compound having a polyoxyalkylene chain. For example, examples of the oxyalkylene unit include those having an alkylene group having 1 to 6 carbon atoms, such as an oxymethylene group, an oxyethylene group, an oxypropylene group, and an oxybutylene group. The hydrocarbon group constituting the oxyalkylene chain may be linear or branched. Examples include polyethylene glycol, polypropylene glycol (diol type), polypropylene glycol (triol type), polytetramethylene ether glycol, methoxypolyethylene glycol, ethoxypolyethylene glycol, and derivatives and copolymers of the above polymers. These may be used singly or in combination of two or more. Since the polyoxyalkylene chain interacts with the ionic compound and promotes dissociation of ions and transports ions by the molecular motion of the chain, an effect of increasing ionic conductivity is obtained.

  The molecular weight of the compound having a polyoxyalkylene chain is preferably a number average molecular weight of 100,000 or less, more preferably 200 to 50,000. When the molecular weight exceeds 100,000, the contamination of the adherend increases, which is not preferable.

The compound (D) having a polyoxyalkylene chain is preferably an organopolysiloxane in which the compound (D) having a polyoxyalkylene chain has a polyoxyalkylene chain. More preferably, the polysiloxane is an organopolysiloxane having a polyoxyalkylene chain represented by the following general formulas (D1) to (D3).

In the formula (D1), R ₁ is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is hydrogen or an organic group, and m and n are integers of 0 to 1000. However, m and n are not 0 at the same time. a and b are integers of 0 to 1000. However, a and b are not 0 at the same time.

In the formula (D2), R ₁ is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is hydrogen or an organic group, and m is an integer of 1 to 2000. a and b are integers of 0 to 1000. However, a and b are not 0 at the same time.

In the formula (D3), R ₁ is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is hydrogen or an organic group, and m is an integer of 1 to 2000. a and b are integers of 0 to 1000. However, a and b are not 0 at the same time.

As the organopolysiloxane having a polyoxyalkylene chain, for example, the following constitution can be used. Specifically, R ₁ in the formula is a monovalent group exemplified by an alkyl group such as a methyl group, an ethyl group or a propyl group, an aryl group such as a phenyl group or a tolyl group, or an aralkyl group such as a benzyl group or a phenethyl group. It is an organic group, and each may have a substituent such as a hydroxyl group. R ₂ , R ₃ and R ₄ may be an alkylene group having 1 to 8 carbon atoms such as a methylene group, an ethylene group or a propylene group. Here, R ₃ and R ₄ are different alkylene groups, and R ₂ may be the same as or different from R ₃ or R ₄ . One of R ₃ and R ₄ is preferably an ethylene group or a propylene group in order to increase the concentration of an ionic compound that can be dissolved in the polyoxyalkylene side chain. R ₅ may be an alkyl group such as a methyl group, an ethyl group or a propyl group, or a monovalent organic group exemplified by an acyl group such as an acetyl group or a propionyl group, each having a substituent such as a hydroxyl group. It may be. These compounds may be used alone or in combination of two or more. Moreover, you may have reactive substituents, such as a (meth) acryloyl group, an allyl group, and a hydroxyl group, in a molecule | numerator.

  Commercially available products of the organopolysiloxane having a polyoxyalkylene chain include, for example, trade names KF-351A, KF-353, KF-945, KF-6011, KF-889, KF-6004 (above, Shin-Etsu Chemical Co., Ltd.) FZ-2122, FZ-2164, FZ-7001, SH8400, SH8700, SF8410, SF8422 (above, manufactured by Toray Dow Corning), TSF-4440, TSF-4445, TSF-4442, TSF-4460 (momentive performance) Materials Co., Ltd.), BYK-333, BYK-377, BYK-UV3500, BYK-UV3570 (manufactured by Big Chemie Japan), and the like. These may be used alone or in combination of two or more.

  The content of the compound (D) having a polyoxyalkylene chain is not particularly limited, but from the viewpoint of adhesive strength (adhesive strength) of the pressure-sensitive adhesive layer and antistatic properties, it is based on 100 parts by mass of the polymer (A). 0.005 to 1 part by mass is preferable, more preferably 0.01 to 0.8 part by mass, and still more preferably 0.03 to 0.5 part by mass.

  In addition to the polymer (A), the (meth) acrylic polymer (B), the ionic compound (C), and the compound (D) having a polyoxyalkylene chain, the pressure-sensitive adhesive composition used in the present invention, Various additives common in the field of pressure-sensitive adhesives can be contained as optional components. Such optional components include, in addition to the additives described above, other tackifying resins, crosslinking agents, catalysts, plasticizers, softeners, fillers, colorants (pigments, dyes, etc.), antioxidants, leveling agents, Examples include stabilizers, preservatives, antistatic agents, and the like. Conventionally known additives can be used as such additives.

<Crosslinking agent>
In order to adjust the cohesive strength of the pressure-sensitive adhesive layer of the present invention, the pressure-sensitive adhesive composition may contain a crosslinking agent. As the crosslinking agent, a crosslinking agent generally used in the pressure-sensitive adhesive field can be used. For example, an isocyanate crosslinking agent, an epoxy crosslinking agent, a silicone crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, or a silane compound. Crosslinking agents, melamine crosslinking agents (alkyl etherified melamine crosslinking agents, etc.), metal chelate crosslinking agents and the like can be mentioned. Moreover, it is also possible to use the said polyfunctional monomer which can be used as a monomer component of the said (meth) acrylic-type polymer (a) mentioned above as a crosslinking agent. In particular, an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, and a metal chelate-based crosslinking agent can be preferably used. These compounds may be used alone or in combination of two or more.

  Examples of the isocyanate-based crosslinking agent (isocyanate compound) include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate. , Aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Coronate L, Nippon Polyurethane Manufactured by Kogyo Co., Ltd.), trimethylolpropane / hexamethylene diisocyanate trimer adduct (trade name Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), hexamethylene dii Isocyanate adducts such as isocyanurate of socyanate (trade name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.). Alternatively, a compound having at least one isocyanate group and one or more unsaturated bonds in one molecule, specifically, 2-isocyanatoethyl (meth) acrylate or the like may be used as an isocyanate-based crosslinking agent. Can do. These compounds may be used alone or in combination of two or more.

  Examples of the epoxy crosslinking agent (epoxy compound) include bisphenol A, epichlorohydrin type epoxy resin, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, and 1,6-hexanediol. Glycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diamine glycidyl amine, N, N, N ′, N′-tetraglycidyl-m-xylenediamine (trade name: TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Inc.) and 1 , 3-bis (N, N-diglycidylaminomethyl) cyclohexane (trade name: TETRAD-C, manufactured by Mitsubishi Gas Chemical Company, Inc.). These compounds may be used alone or in combination of two or more.

  Examples of the melamine-based crosslinking agent include hexamethylol melamine. Examples of the aziridine-based cross-linking agent (aziridine derivative) include, for example, a commercial product name HDU (manufactured by Mutual Pharmaceutical Co., Ltd.), a product name TAZM (manufactured by Mutual Pharmaceutical Co., Ltd.), and a trade name TAZO (mutual pharmaceutical Co., Ltd.). Manufactured). These compounds may be used alone or in combination of two or more.

  Examples of the metal chelate-based crosslinking agent (metal chelate compound) include aluminum, iron, tin, titanium and nickel as metal components, and acetylene, methyl acetoacetate and ethyl lactate as chelate components. These compounds may be used alone or in combination of two or more.

  The content of the crosslinking agent used in the present invention is not particularly limited. For example, it is preferably contained in an amount of 0.001 to 0.8 parts by mass with respect to 100 parts by mass of the polymer (A), and 0.01 to 0 It is more preferable to contain 7 parts by mass. When the content of the cross-linking agent is less than 0.001 part by mass, the cohesive force of the pressure-sensitive adhesive (layer) may be reduced and the chemical solution may enter. On the other hand, when the content of the cross-linking agent exceeds 0.8 parts by mass, the cohesive force of the pressure-sensitive adhesive (layer) is large, the fluidity is lowered, the wetness to the adherend becomes insufficient, and the adhesive strength ( Adhesive strength) may be reduced.

  Further, the content of the polyfunctional monomer is appropriately selected depending on the balance with the polymer to be crosslinked, and further depending on the intended use of the pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet, surface protective sheet). In order to obtain sufficient heat resistance by the cohesive force of the pressure-sensitive adhesive (layer), when the polymer (A) (for example, the (meth) acrylic polymer (a)) is used, the polymer (A) It is preferable to mix | blend with 0.001-1.0 mass part with respect to 100 mass parts. Moreover, it is more preferable to mix | blend at 0.5 mass part or less with respect to 100 mass parts of said polymers (A) from the point of a softness | flexibility and adhesiveness.

  In addition, when using the said polyfunctional monomer as a crosslinking agent, in order to advance a crosslinking reaction, radiation irradiation can be performed. Examples of the radiation include ultraviolet rays, laser beams, α rays, β rays, γ rays, X rays, and electron beams, but ultraviolet rays are preferably used from the viewpoint of good controllability and handleability and cost. . More preferably, ultraviolet rays having a wavelength of 200 to 400 nm are used. Ultraviolet rays can be irradiated using an appropriate light source such as a high-pressure mercury lamp, a microwave excitation lamp, or a chemical lamp. When ultraviolet rays are used as radiation, the pressure-sensitive adhesive composition includes a photopolymerization initiator (photoinitiator) that can be used in the preparation (polymerization) of the above-described (meth) acrylic polymer (a), and A photopolymerization initiation assistant can be similarly blended and added. In addition, when the polyfunctional monomer is used as a crosslinking agent, it can be irradiated with radiation, but as the photopolymerization initiator used in this case, depending on the type of the radiation reactive component, the polymerization reaction may be performed. Any substance that generates radicals or cations by irradiating ultraviolet rays having an appropriate wavelength that can be triggered can be used.

  The said photoinitiator is normally mix | blended 0.1-10 mass parts with respect to 100 mass parts of said polymers (A), and it is preferable to mix | blend in 0.2-7 mass parts. Within the above range, it is preferable from the viewpoint of easily controlling the polymerization reaction and obtaining an appropriate molecular weight.

In the case where the photopolymerization initiator is added, the pressure-sensitive adhesive composition is directly applied on an adherend (protected body) or after being applied to a predetermined coated body such as a separator, or Then, after coating on one side of the support (base material), the cross-linking reaction is advanced by light irradiation to obtain a pressure-sensitive adhesive layer. Usually, the pressure-sensitive adhesive layer is obtained by irradiating ultraviolet rays having an illuminance of 1 to 200 mW / cm ² at a wavelength of 300 to 400 nm and photopolymerizing them with a light amount of about 200 to 4000 mJ / cm ² .

  The pressure-sensitive adhesive composition used in the present invention may further contain a crosslinking accelerator. The kind of crosslinking accelerator can be suitably selected according to the kind of crosslinking agent to be used. In the present specification, the crosslinking accelerator refers to a catalyst that increases the speed of the crosslinking reaction by the crosslinking agent. Examples of the crosslinking accelerator include tin (Sn) -containing compounds such as dioctyltin dilaurate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin diacetylacetonate, tetra-n-butyltin, and trimethyltin hydroxide; N, N , N ′, N′-tetramethylhexanediamine, amines such as triethylamine, and nitrogen (N) -containing compounds such as imidazoles. Of these, Sn-containing compounds are preferred. The amount of the crosslinking accelerator contained in the pressure-sensitive adhesive composition is, for example, about 0.0001 to 1.0 part by mass (preferably about 0.001 to 0.5 part by mass) with respect to 100 parts by mass of the polymer (A). ).

  The pressure-sensitive adhesive composition used in the present invention can further contain a compound that causes keto-enol tautomerism. For example, in a pressure-sensitive adhesive composition containing a cross-linking agent or a pressure-sensitive adhesive composition that can be used by blending a cross-linking agent, an embodiment including a compound that produces the keto-enol tautomerism can be preferably employed. Thereby, the excessive viscosity raise and gelation of an adhesive composition after a crosslinking agent mixing | blending can be suppressed, and the effect of extending the pot life of an adhesive composition may be implement | achieved. When at least an isocyanate compound is used as the crosslinking agent, it is particularly meaningful to contain a compound that causes keto-enol tautomerism. This technique can be preferably applied when, for example, the pressure-sensitive adhesive composition is in an organic solvent solution or a solvent-free form.

  Various β-dicarbonyl compounds can be used as the compound that causes keto-enol tautomerism. Specific examples include acetylacetone, 2,4-hexanedione, 3,5-heptanedione, 2-methylhexane-3,5-dione, 6-methylheptane-2,4-dione, 2,6-dimethylheptane- Β-diketones such as 3,5-dione; acetoacetates such as methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, tert-butyl acetoacetate; ethyl propionyl acetate, ethyl propionyl acetate, isopropyl propionyl acetate, propionyl acetate propionyl acetates such as tert-butyl; isobutyryl acetates such as ethyl isobutyryl acetate, ethyl isobutyryl acetate, isopropyl isobutyryl acetate, tert-butyl isobutylyl acetate; malonates such as methyl malonate and ethyl malonate; etc. And the like. Among these, acetylacetone and acetoacetic acid esters are preferable compounds. Such compounds that produce keto-enol tautomerism may be used alone or in combinations of two or more.

  Content of the compound which produces the keto-enol tautomerism can be 0.1-20 mass parts with respect to 100 mass parts of the polymers (A), and usually 0.5-15 mass parts. (For example, 1 to 10 parts by mass) is appropriate. If the amount of the compound is too small, it may be difficult to achieve a sufficient use effect. On the other hand, if the compound is used more than necessary, it may remain in the pressure-sensitive adhesive layer and reduce the cohesive force.

  The said adhesive composition may contain tackifying resin as needed. The above-mentioned (meth) acrylic copolymer (B) has a function as a tackifying resin in the pressure-sensitive adhesive layer of the present invention, and further, other conventionally known tackifying resins are particularly limited. It can be used without. For example, terpene tackifier resin, phenol tackifier resin, rosin tackifier resin, aliphatic petroleum resin, aromatic petroleum resin, copolymer petroleum resin, alicyclic petroleum resin, xylene resin, epoxy tackifier Examples include an imparting resin, a polyamide tackifying resin, a ketone tackifying resin, and an elastomer tackifying resin. These can be used alone or in combination of two or more. In the case of using a tackifier resin, the content of the polymer (A) or (meth) acrylic polymer (B) does not deteriorate the properties of the tackifier resin from the viewpoint of sufficiently obtaining the effect of the tackifier resin. A) It is preferable to set it as 20 mass parts or less (typically 0.01-10 mass parts) with respect to 100 mass parts.

  The pressure-sensitive adhesive composition may be prepared by blending the polymer (A) with another polymer (arbitrary polymer) as necessary. Such an optional polymer can be blended, for example, for the purpose of increasing the cohesive strength of the pressure-sensitive adhesive. An increase in the cohesive strength of the pressure-sensitive adhesive prevents the liquid from entering the liquid from the outer edge of the pressure-sensitive adhesive sheet (surface protective sheet) (typically prevents the liquid from entering the liquid mainly due to the pressure-sensitive adhesive swelling) Performance).

<Adhesive layer for chemical treatment>
The pressure-sensitive adhesive layer of the present invention can be a cured layer of a pressure-sensitive adhesive composition. For example, the pressure-sensitive adhesive layer can be formed by applying a pressure-sensitive adhesive composition to a suitable support (for example, coating / coating) and then appropriately performing a curing treatment. In the case where the support is a plastic substrate subjected to an antistatic treatment, an adhesive layer can be formed on the antistatic layer, or an adhesive layer can be formed on the surface not subjected to the antistatic treatment. When performing 2 or more types of hardening processes (drying, bridge | crosslinking, superposition | polymerization, etc.), these can be performed simultaneously or in multiple steps. In a pressure-sensitive adhesive composition using a partial polymer (acrylic polymer syrup), typically, as the curing treatment, a final copolymerization reaction is performed (the partial polymer is subjected to a further copolymerization reaction). A complete polymer is formed). For example, if it is a photocurable adhesive composition, light irradiation is implemented. If necessary, curing treatment such as cross-linking and drying may be performed. For example, when it is necessary to dry with a photocurable adhesive composition, it is good to perform photocuring after drying. In the pressure-sensitive adhesive composition using a completely polymerized product, typically, as the curing treatment, treatments such as drying (heat drying) and crosslinking are performed as necessary.

  Application and application of the pressure-sensitive adhesive composition (pressure-sensitive adhesive composition solution) are, for example, conventional gravure roll coaters, reverse roll coaters, kiss roll coaters, dip roll coaters, bar coaters, knife coaters, spray coaters and the like. It can be carried out using a coater. The pressure-sensitive adhesive composition may be directly applied to the support (base material) to form a pressure-sensitive adhesive layer, or the pressure-sensitive adhesive layer formed on the release liner may be transferred to the support.

  The thickness of the pressure-sensitive adhesive layer is not particularly limited and can be appropriately adjusted according to the purpose. The thickness of the pressure-sensitive adhesive layer can be, for example, about 1 to 100 μm. Note that, from the viewpoint of adhesion to the adherend surface, the preferred thickness is 2 μm or more, more preferably 3 μm or more (for example, 5 μm or more, typically 7 μm or more). From the viewpoint of peeling workability, the thickness of the pressure-sensitive adhesive layer is preferably 90 μm or less, more preferably 70 μm or less, and typically 50 μm or less. It is preferable that the thickness of the pressure-sensitive adhesive layer is not too large from the viewpoint of suppressing the infiltration of the chemical liquid due to the swelling of the pressure-sensitive adhesive.

The arithmetic average surface roughness of the surface of the pressure-sensitive adhesive layer (adhesive surface, that is, the surface to be adhered to the adherend) is preferably 1 μm or less, and is approximately 0.05 to 0.75 μm (for example, approximately 0.05 to More preferably, it is in the range of 0.5 μm, typically approximately 0.1 to 0.3 μm. When the smoothness of the adhesive surface is increased, the adhesion between the adhesive surface and the adherend surface is improved. As a result, it is possible to better prevent the chemical solution from entering the interface between the adhesive and the adherend. In addition, since the adhesive layer with high smoothness has less stress bias when peeling from the surface of the adherend, a part of the adhesive is cut off due to local stress and remains on the adherend side. Can be avoided well. Therefore, the pressure-sensitive adhesive sheet (surface protective sheet) having such a pressure-sensitive adhesive layer on the support (base material) can be smoothly peeled off from the adherend without causing contamination such as adhesive residue on the surface of the adherend. obtain.
The arithmetic average surface roughness of the adhesive surface is measured using a general surface roughness measuring device (for example, a non-contact three-dimensional surface shape measuring device manufactured by Veeco, model “Wyko NT-3300”). Can do.

  Moreover, the pressure-sensitive adhesive layer of the present invention has a solvent-insoluble component ratio (gel fraction) of 50 to 90% by mass, preferably 55 to 87% by mass, and more preferably 60 to 85% by mass. If the solvent-insoluble component ratio exceeds 90% by mass, the adhesive strength (adhesive strength) decreases, and if it is lower than 50% by mass, the cohesive force of the adhesive (layer) decreases and adhesive residue may occur. is there. In addition, the evaluation method of a solvent insoluble component rate is measured according to the method and conditions described in the Example mentioned later.

The pressure-sensitive adhesive layer has a surface resistivity of 10 ³ to 10 ¹³ Ω / □, preferably 10 ⁴ to 10 ¹³ Ω / □, and more preferably 10 ⁶ to 10 ¹³ Ω / □. is there. Within the above range, it is useful because it is possible to suppress the stripping voltage, that is, to impart antistatic properties. In addition, the evaluation method of the said surface resistivity is measured according to the method and conditions described in the Example mentioned later.

<Support>
The pressure-sensitive adhesive sheet for chemical treatment according to the present invention is preferably formed by forming the pressure-sensitive adhesive layer on at least one surface of a support. The pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer is useful because it has excellent chemical solution intrusion prevention properties and antistatic properties. In addition, as a support body (base material) used for the said adhesive sheet (surface protection sheet), support bodies, such as a well-known film form and a sheet form, can be selected suitably, and can be used. The material of the support is not particularly limited. For example, a support formed from a metal material (aluminum or the like), a support formed from a resin material, a support formed from a composite material thereof (for example, a plastic film having a metal deposited on one side), or the like can be used. .

Preferred examples of the support (base material) in the technology disclosed herein include polyethylene (PE), polypropylene (PP), ethylene propylene rubber (EPR), ethylene-propylene-butene copolymer, ethylene-ethyl acrylate copolymer. Polyolefin resin such as coalescence; Polyester resin such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate; Polyamide resin (PA); Polyimide resin (PI); Polyphenylene sulfide resin (PPS); Polycarbonate resin (PC ); Polyurethane resin (PU); ethylene-vinyl acetate resin (EVA); fluororesin such as polytetrafluoroethylene (PTFE); support (plastic film) made of a resin material such as acrylic resin . It may be a support made of a resin material containing one kind of such resin alone, or a support (plastic film) made of a resin material in which two or more kinds are blended.
Here, the plastic film typically refers to a non-porous plastic film and is a concept distinguished from a woven fabric and a non-woven fabric. As the support for the pressure-sensitive adhesive sheet (surface protective sheet) disclosed herein, any of an unstretched plastic film and a stretched (uniaxially stretched or biaxially stretched) plastic film can be used.

Among these, as a preferable resin material from the viewpoint of having appropriate flexibility, a polyolefin resin (for example, one of polyolefin resins such as PP, PE, EPR, or a mixture of two or more of them is blended). Polyolefin resin) and polyester resin (for example, PET). Since the polyolefin resin and the polyester resin have appropriate flexibility, the pressure-sensitive adhesive sheet (surface protective sheet) having such a support made of a resin material can be used even when there is a surface step of the adherend. It is easy to follow the step (that is, the surface shape followability is high). Therefore, it is difficult to form a chemical solution intrusion path (void) between the pressure-sensitive adhesive (layer) constituting the pressure-sensitive adhesive sheet and the adherend. Therefore, it is suitable as a support for an adhesive sheet (surface protective sheet) for chemical treatment.
The step may be derived from a structure formed on the surface of the adherend. As an adherend having such a structure, for example, a transparent conductive film (for example, ITO (indium tin oxide) is partially formed on the surface, such as used in tablet computers, mobile phones, and organic LEDs (light emitting diodes). ) Film) or a glass substrate provided with a flexible printed circuit board (FPC).

  As the support (base material) of the pressure-sensitive adhesive sheet (surface protective sheet) disclosed herein, a support made of a resin material having high acid resistance can be preferably used. Such a support is an acidic chemical solution (for example, a hydrofluoric acid solution used for glass etching, an acidic solution such as a chromium plating solution, a copper sulfate plating solution, a nickel plating solution, an acidic electroless nickel plating solution, or an acidic tin plating solution). Difficult to swell even when exposed to plating solution. Therefore, it is advantageous to prevent the acidic chemical from swelling the support and entering the pressure-sensitive adhesive sheet (surface protective sheet) and reaching the adherend (non-treatment target portion). Examples of a preferable support from the viewpoint of excellent balance between acid resistance and flexibility include those made of polyolefin resin.

  The support (base material) may be a single layer or a multilayer structure having two or more layers (for example, a three-layer structure). For example, a resin film having a multilayer structure (multilayer film) including the above-described film can be used as the support. In the multilayer film, the resin material constituting each layer may be a resin material containing one kind of resin as described above alone, or may be a resin material in which two or more kinds of resins are blended.

  In a preferred embodiment, the support (base material) is a single-layer or multilayer polyolefin resin film. Here, the polyolefin resin film refers to a plastic film formed from a resin material containing a polyolefin resin (that is, a resin containing polyolefin as a main component). The proportion of the polyolefin resin in the resin component (polymer component) in the polyolefin resin film is preferably more than 50% by mass, preferably 75% by mass or more, and more preferably 90% by mass or more. The resin component may be a film substantially made of a polyolefin resin. Alternatively, a resin component is formed from a resin material containing a resin component (PA, PC, PU, EVA, etc.) other than a polyolefin resin in addition to a polyolefin resin as a main component (for example, a component exceeding 50% by mass in the resin component). It may be a film made.

  As said polyolefin resin, one type of polyolefin can be used individually or in combination of 2 or more types of polyolefin. The polyolefin may be, for example, an α-olefin homopolymer, a copolymer of two or more α-olefins, a copolymer of one or two or more α-olefins and another vinyl monomer, and the like. Specific examples include ethylene-propylene copolymers such as PE, PP, EPR, ethylene-propylene-butene copolymers, ethylene-ethyl acrylate copolymers, and the like. Both low density (LD) polyolefins and high density (HD) polyolefins can be used. Such polyolefin resin films include biaxially oriented polypropylene (OPP) film, low density polyethylene (LDPE) film, linear low density polyethylene (LLDPE) film, medium density polyethylene (MDPE) film, and high density polyethylene (HDPE). ) Film, a polyethylene (PE) film obtained by blending two or more kinds of polyethylene (PE), a PP / PE blend film obtained by blending polypropylene (PP) and polyethylene (PE), and a polyolefin resin film such as various flexible polyolefin films. .

The PP may be various polymers (propylene polymers) containing propylene as a main monomer (main constituent monomer, that is, a component exceeding 50% by mass of the whole monomer). The concept of propylene-based polymer here includes, for example, the following polypropylene.
A homopolymer of propylene (ie homopolypropylene). For example, isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene.
A random copolymer (random polypropylene) of propylene and another α-olefin (typically, one or more selected from ethylene and an α-olefin having 4 to 10 carbon atoms). For example, random polypropylene obtained by random copolymerization of 96 to 99.9 mol% of propylene and 0.1 to 4 mol% of other α-olefin (preferably ethylene and / or butene).
A copolymer (block polypropylene) obtained by block copolymerizing propylene with another α-olefin (typically, one or more selected from ethylene and an α-olefin having 4 to 10 carbon atoms). Such a block polypropylene may further contain a rubber component containing at least one of propylene and the other α-olefin as a by-product. For example, a polymer obtained by block copolymerization of 90 to 99.9 mol% of propylene with 0.1 to 10 mol% of other α-olefin (preferably ethylene and / or butene), and propylene and other α-olefins as by-products A block polypropylene further comprising a rubber component having at least one of them as a component.

  The PP resin may be a resin in which the main component of the resin component is a propylene-based polymer as described above and another polymer is blended as a subcomponent. The other polymer includes an α-olefin other than propylene, for example, an α-olefin having 2 or 4 to 10 carbon atoms as a main monomer (main constituent monomer, that is, a component exceeding 50% by mass of the whole monomer). One or more of the polyolefins to be treated. The PP resin may have a composition containing at least PE as the accessory component. The PE content can be, for example, 3 to 50 parts by mass (typically 5 to 30 parts by mass) per 100 parts by mass of PP. The resin component may be a PP resin substantially composed of PP and PE. Further, it may be a PP resin containing at least PE and EPR as subcomponents (for example, a PP resin whose resin component is substantially composed of PP, PE, and EPR). In this case, the content of EPR can be, for example, 3 to 50 parts by mass (typically 5 to 30 parts by mass) per 100 parts by mass of PP.

  The PE may be a homopolymer of ethylene, or a copolymer of ethylene as a main monomer and another α-olefin (for example, an α-olefin having 3 to 10 carbon atoms). Preferable examples of the α-olefin include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and the like. Any of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE) can be used. For example, LDPE and / or LLDPE can be preferably employed.

  As the support (base material), a polyolefin resin film containing an olefin polymer alloy and a carbonyl unit-containing thermoplastic resin can also be used. Here, the carbonyl unit-containing thermoplastic resin refers to a thermoplastic resin containing a carbonyl (C═O) unit in the molecular skeleton. Such a polyolefin resin film may be substantially free of halogen atoms and have flexibility, heat resistance, and flame retardancy comparable to polyvinyl chloride (PVC).

  The olefin polymer alloy is a component mainly for suppressing thermal deformation of the support (base material), and is preferably a polymer alloy containing an ethylene component and a propylene component. The form of the polymer alloy is not particularly limited. For example, a polymer blend in which two or more kinds of polymers are physically mixed, a block copolymer or a graft copolymer in which two or more kinds of polymers are bonded by a covalent bond, and two kinds Various forms such as an IPN (Interpenetrating Polymer Network) structure in which the above polymers are intertwined without being covalently bonded to each other can be used. Further, it may be a compatible polymer alloy in which two or more kinds of polymers are compatible, or an incompatible polymer alloy in which two or more kinds of polymers are incompatible and form a phase separation structure.

  Examples of such an olefin polymer alloy include a polymer blend of polypropylene (homopolypropylene, random polypropylene) and polyethylene (including a copolymer of ethylene and a small amount of α-olefin), propylene / ethylene copolymer, propylene. A terpolymer of ethylene and other α-olefins other than these (as other α-olefins, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene) 1-octene, and 1-butene is preferred.

  When the olefin polymer alloy is a copolymer, it is preferably a multistage polymerized olefin copolymer (preferably an ethylene / propylene copolymer) polymerized by two or more stages of multistage polymerization. Examples of such a multistage polymerized olefin copolymer include polymer alloys as described in JP-A No. 2001-192629. That is, a first-stage polymerization is performed using a monomer mixture containing propylene as a main component, and then a polypropylene (first stage) / propylene-ethylene copolymer obtained by copolymerizing propylene and ethylene in the second and subsequent stages ( It is a polymer alloy of the second and subsequent stages. The first stage polymerization is preferably carried out in the presence of a titanium compound catalyst and an organoaluminum compound catalyst. The second and subsequent polymerizations are preferably carried out in the presence of a titanium-containing polyolefin formed by the first polymerization and an organoaluminum compound catalyst. As the titanium compound catalyst, for example, titanium trichloride and magnesium chloride were co-ground and treated with n-butyl orthotitanate, 2-ethyl-hexanol, ethyl p-toluate, silicon tetrachloride, diisobutyl phthalate, or the like. Examples thereof include a solid catalyst having a spherical shape and an average particle diameter of 1 to 30 μm. Examples of the organoaluminum compound catalyst include alkylaluminum such as triethylaluminum. In the polymerization layer, a silicon compound such as diphenyldimethoxysilane or an iodine compound such as ethyl iodide may be added as an electron donor.

  From the viewpoint of suppressing thermal deformation, the olefin polymer alloy has a dynamic storage elastic modulus (E ′) at 80 ° C. of 40 MPa or more and less than 180 MPa (for example, 45 MPa to 160 MPa), and dynamic storage at 120 ° C. Those having an elastic modulus (E ′) of 12 MPa or more and less than 70 MPa (for example, 15 MPa to 65 MPa) are preferable. In consideration of surface shape followability and workability near room temperature, the dynamic storage elastic modulus (E ′) at 23 ° C. is preferably 200 MPa or more and less than 400 MPa. The dynamic storage elastic modulus (E ′) is a test piece (thickness 0.2 mm, width 10 mm, length 20 mm) made of a polymer alloy, and the dynamic viscoelastic behavior due to temperature dispersion of the test piece is measured. It is a value measured using DMS200 (manufactured by Seiko Instruments Inc.) as a device under predetermined measurement conditions (for example, measurement method: tension mode, temperature increase rate: 2 ° C./min, frequency: 1 Hz). As an example of such a polymer alloy, trade names “Cataloy KS-353P”, “Cataloy KS-021P”, “Cataloy C200F”, “Cataloy Q-200F” manufactured by Sun Allomer Co., Ltd., and the like can be given.

  The carbonyl unit-containing thermoplastic resin is used to give the support (base material) moderate flexibility and good extensibility, and includes a carbonyl (C═O) unit in the molecular skeleton. Resin. As will be described later, when the polyolefin resin film contains an inorganic flame retardant, it may be a component that activates the flame retardancy imparting action of the inorganic flame retardant. As such a thermoplastic resin, a flexible polyolefin resin containing a carbonyl unit in the molecular skeleton is suitable. For example, an ethylene copolymer (ethylene / vinyl ester copolymer, ethylene / unsaturated carboxylic acid copolymer) synthesized using a vinyl ester and / or an α, β-unsaturated carboxylic acid or a derivative thereof as a monomer or comonomer. And the like, and metal salts thereof. The melting point of the thermoplastic resin is not particularly limited, but is preferably 120 ° C. or lower (typically 40 to 100 ° C.). The melting point can be measured by a general differential scanning calorimeter (DSC).

  Examples of the vinyl ester in the ethylene copolymer or metal salt thereof include carboxylic acid vinyl esters such as vinyl acetate. Examples of the α, β-unsaturated carboxylic acid or derivatives thereof include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, maleic anhydride, and itaconic anhydride or anhydrides thereof; methyl ( (Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, maleic acid Examples thereof include unsaturated carboxylic acid esters such as 1-methyl, 1-ethyl maleate, diethyl maleate, 1-methyl fumarate, and glycidyl (meth) acrylate. These can be used alone or in combination of two or more. Of these, alkyl (meth) acrylate is preferable, and ethyl acrylate is more preferable.

  Preferred examples of the ethylene / vinyl ester copolymer and the ethylene / unsaturated carboxylic acid copolymer include an ethylene / acrylic acid copolymer, an ethylene / methacrylic acid copolymer, an ethylene / ethyl acrylate copolymer, an ethylene / Acrylic acid / ethyl acrylate copolymer, ethylene / vinyl acetate copolymer, ethylene / vinyl acetate / ethyl acrylate copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / glycidyl methacrylate-ethyl acrylate copolymer and their metals Salt. These can be used alone or in combination of two or more.

  The polyolefin resin film containing the olefin polymer alloy and the carbonyl unit-containing thermoplastic resin preferably contains an inorganic flame retardant. Examples of such inorganic flame retardants include metal hydroxides such as aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, calcium hydroxide, and barium hydroxide; basic magnesium carbonate, magnesium carbonate-calcium, calcium carbonate, Metal carbonates such as barium carbonate and dolomite; metal hydrates such as hydrotalcite and borax (hydrates of metal compounds); inorganic metal compounds such as barium metaborate and magnesium oxide. These can be used alone or in combination of two or more. Of these, metal hydroxides such as aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, calcium hydroxide, and barium hydroxide, basic magnesium carbonate, and hydrotalcite are preferable.

  The inorganic flame retardant is preferably subjected to a surface treatment with a silane coupling agent. Thereby, various properties such as flexibility, heat resistance and flame retardancy can be further improved. Specific examples of such silane coupling agents include vinyltriethoxysilane, vinyl-tolyl (2-methoxy-ethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ- Aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxy Examples include silane, N-phenyl-γ-aminopropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane. These can be used alone or in combination of two or more.

  The surface treatment method of the inorganic metal compound with the silane coupling agent is not particularly limited, and conventionally known methods such as a dry treatment method and a wet treatment method can be appropriately employed. The amount of adhesion of the silane coupling agent to the surface of the inorganic metal compound can vary depending on the type of coupling agent, the type of inorganic metal compound, the specific surface area, etc. Usually, it is about 0.1-5.0 mass parts (for example, 0.3-3.0 mass parts).

  The blending ratio of the olefin polymer alloy and the carbonyl unit-containing thermoplastic resin is not particularly limited, but from the viewpoint of achieving both heat resistance and flame retardancy, for example, 90:10 to 20:80 on a mass basis. preferable. Moreover, when mix | blending an inorganic type flame retardant, the compounding quantity is 100 mass parts of polymer components (the sum total of a multistage polymerization olefin copolymer and a carbonyl unit containing thermoplastic resin) from a viewpoint of a flame retardance improvement and a softness | flexibility maintenance. The amount is preferably about 10 to 200 parts by mass (for example, 20 to 100 parts by mass).

  Any resin film described above may contain an appropriate component depending on the application of the pressure-sensitive adhesive sheet (surface protective sheet) as necessary. For example, additives such as light stabilizers such as radical scavengers and ultraviolet absorbers, antioxidants, antistatic agents, colorants (dyes, pigments, etc.), fillers, slip agents, antiblocking agents, etc. may be appropriately blended. it can.

  Examples of the light stabilizer include those containing benzotriazoles, hindered amines, benzoates and the like as active ingredients.

  Examples of the antioxidant include those containing alkylphenols, alkylene bisphenols, thiopropylene acid esters, organic phosphite esters, amines, hydroquinones, hydroxylamines and the like as active ingredients.

  Such additives can be used alone or in combination of two or more. The content of the additive is a normal content of a resin film used as a support (base material) for the surface protection sheet in the application depending on the use of the surface protection sheet (for example, for glass etching or plating masking). The amount can be approximately the same as the amount (blending amount).

  Such a support (base material) (resin film) can be produced by appropriately adopting a conventionally known general film forming method (extrusion molding, inflation molding, etc.). The surface of the support on which the pressure-sensitive adhesive layer is provided (the pressure-sensitive adhesive layer-side surface, the surface to which the pressure-sensitive adhesive is applied) is treated to improve the adhesion with the pressure-sensitive adhesive layer (throwing of the pressure-sensitive adhesive). Surface treatment such as corona discharge treatment, acid treatment, ultraviolet irradiation treatment, plasma treatment, and primer (primer) coating may be performed. As the surface treatment (primer treatment) by primer application, it is preferable to use an undercoat agent in which an isocyanate is blended with an acrylic polymer. A surface (back surface) opposite to the pressure-sensitive adhesive layer-side surface of the support may be subjected to surface treatment such as antistatic treatment or peeling treatment as necessary. As the release treatment, for example, by providing a long-chain alkyl-based or silicone-based release treatment layer on the back surface of the support, the unwinding force of the surface protection sheet wound in a roll shape can be reduced.

  The thickness of the support (base material) can be appropriately selected according to the flexibility (hardness) of the resin film to be used. In general, the thickness of the support is preferably 500 μm or less (preferably 400 μm or less, more preferably 300 μm or less, typically 250 μm or less, for example, 200 μm or less) from the viewpoint of followability and adhesion to a stepped surface. It is. Further, from the viewpoint of peeling workability and other handling properties (handling properties), the thickness of the support is suitably 10 μm or more (preferably 20 μm or more, more preferably 25 μm or more, for example 30 μm or more). Moreover, when the thickness of a support body becomes large, it exists in the tendency which becomes easy to prevent the swelling penetration | invasion of the chemical | medical solution from the surface protection sheet surface.

  The surface on the side of the support on which the pressure-sensitive adhesive layer is provided does not affect the surface state of the pressure-sensitive adhesive layer (surface roughness of the pressure-sensitive adhesive surface) (that is, increases the arithmetic average surface roughness of the pressure-sensitive adhesive surface). It is preferable to have a smoothness that is not a factor. For example, the support preferably has an arithmetic average surface roughness of the pressure-sensitive adhesive layer side surface of 1 μm or less, 0.05 to 0.75 μm (for example, approximately 0.05 to 0.5 μm, typically More preferably, it is approximately 0.1 to 0.3 μm. By setting it as this structure, the smoothness of an adhesive surface also becomes high.

  For the support, if necessary, silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, mold release with silica powder and the like, acid treatment, alkali treatment, primer treatment, Anti-adhesive treatment such as corona treatment, plasma treatment and ultraviolet treatment, coating type, kneading type, vapor deposition type and the like can also be carried out.

  The support (plastic film) used for the pressure-sensitive adhesive sheet (surface protective sheet) of the present invention is more preferably subjected to antistatic treatment. By carrying out the antistatic treatment, the generation of static electricity can be prevented, which is useful in the technical fields related to optical and electronic components where charging becomes a particularly serious problem. The antistatic treatment applied to the plastic film is not particularly limited, and a method of providing an antistatic layer on at least one surface of a generally used film or a method of kneading a kneading type antistatic agent into the plastic film is used. As a method of providing an antistatic layer on at least one surface of the film, an antistatic resin comprising an antistatic agent and a resin component, a conductive polymer, a method of applying a conductive resin containing a conductive material, or a conductive material is deposited. Or the method of plating is mentioned.

  Antistatic agents contained in the antistatic resin include cationic antistatic agents having cationic functional groups such as quaternary ammonium salts, pyridinium salts, primary, secondary and tertiary amino groups, sulfonic acids Anionic antistatic agents having an anionic functional group such as salts, sulfate esters, phosphonates and phosphate esters, alkylbetaines and derivatives thereof, imidazolines and derivatives thereof, and amphoteric antistatic agents such as alanine and derivatives thereof Nonionic antistatic agents such as amino alcohol and derivatives thereof, glycerin and derivatives thereof, polyethylene glycol and derivatives thereof, and monomers having an ion conductive group of the cation type, anion type and zwitterionic type are polymerized Or the ion conductive polymer obtained by copolymerization is mentioned. These compounds may be used alone or in combination of two or more.

  Specifically, examples of the cationic antistatic agent include quaternary ammonium such as alkyltrimethylammonium salt, acyloylamidopropyltrimethylammonium methosulfate, alkylbenzylmethylammonium salt, acylcholine chloride, and polydimethylaminoethyl methacrylate. (Meth) acrylate copolymer having a group, styrene copolymer having a quaternary ammonium group such as polyvinylbenzyltrimethylammonium chloride, diallylamine copolymer having a quaternary ammonium group such as polydiallyldimethylammonium chloride, and the like. . These compounds may be used alone or in combination of two or more.

  Examples of the anionic antistatic agent include alkyl sulfonate, alkyl benzene sulfonate, alkyl sulfate ester salt, alkyl ethoxy sulfate ester salt, alkyl phosphate ester salt, and sulfonic acid group-containing styrene copolymer. These compounds may be used alone or in combination of two or more.

  Examples of the zwitterionic antistatic agent include alkylbetaine, alkylimidazolium betaine, and carbobetaine graft copolymerization. These compounds may be used alone or in combination of two or more.

  Examples of the nonionic antistatic agent include fatty acid alkylolamide, di (2-hydroxyethyl) alkylamine, polyoxyethylene alkylamine, fatty acid glycerin ester, polyoxyethylene glycol fatty acid ester, sorbitan fatty acid ester, and polyoxyethylene. Examples include sorbitan fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyethylene glycol, polyoxyethylene diamine, a copolymer composed of polyether, polyester and polyamide, and methoxypolyethylene glycol (meth) acrylate. These compounds may be used alone or in combination of two or more.

  Examples of the conductive polymer include polyaniline, polypyrrole, and polythiophene.

  Examples of the conductive material include tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, and cobalt. , Copper iodide, and alloys or mixtures thereof.

  As the resin component used for the antistatic resin and the conductive resin, general-purpose resins such as polyester, acrylic, polyvinyl, urethane, melamine, and epoxy are used. In the case of a polymer type antistatic agent, it is not necessary to contain a resin component. Further, the antistatic resin component can contain a methylol- or alkylol-containing melamine-based, urea-based, glyoxal-based, acrylamide-based compound, epoxy compound, or isocyanate-based compound as a crosslinking agent.

  The antistatic layer can be formed by, for example, diluting the antistatic resin, conductive polymer, or conductive resin with a solvent such as an organic solvent or water, and applying and drying the coating liquid on a plastic film. It is formed.

  Examples of the organic solvent used for forming the antistatic layer include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, toluene, xylene, methanol, ethanol, n-propanol, and isopropanol. Can be mentioned. These solvents may be used alone or in combination of two or more.

  As a coating method in forming the antistatic layer, a known coating method is appropriately used. Specifically, for example, roll coating, gravure coating, reverse coating, roll brush, spray coating, air knife coating, impregnation and The curtain coat method is mentioned.

  The thickness of the antistatic resin layer, the conductive polymer, and the conductive resin is usually about 0.01 to 5 μm, preferably about 0.03 to 1 μm.

  Examples of the method for depositing or plating the conductive material include vacuum deposition, sputtering, ion plating, chemical vapor deposition, spray pyrolysis, chemical plating, and electroplating.

  The thickness of the conductive material layer is usually 2 to 1000 nm, preferably 5 to 500 nm.

  Further, as the kneading type antistatic agent, the antistatic agent is appropriately used. The content (blending amount) of the kneading type antistatic agent is 20% by mass or less, preferably 0.05 to 10% by mass with respect to the total mass of the plastic film as the support. The kneading method is not particularly limited as long as the antistatic agent can be uniformly mixed with the resin used for the plastic film. For example, a heating roll, a Banbury mixer, a pressure kneader, a biaxial kneader or the like is used. It is done.

  The pressure-sensitive adhesive sheet (surface protective sheet) of the present invention is a pressure-sensitive adhesive sheet with a release liner (surface protective sheet) in which a release liner is disposed on the surface of the pressure-sensitive adhesive layer before use (before application to an adherend). It can be in the form of When the release liner is placed on the adhesive surface and the surface (release surface) facing the adhesive surface is excellent in smoothness, the adhesive surface (adhesive surface) is smooth until the adhesive sheet (surface protective sheet) is used. Sex can be maintained more stably.

As the release liner (separator), various types of paper (which may be paper having a resin laminated on the surface), a resin film, and the like can be used without particular limitation. When using a resin film as a release liner, preferred examples of the resin component constituting the resin film include polyolefin resins, polyester resins such as PET, polyamide resins, polycarbonate resins, polyurethane resins and the like. A release liner made of a resin material containing one kind of such resin may be used, or a release liner made of a resin material in which two or more kinds of resins (for example, PE and PP) are blended may be used. . Such a resin film for a release liner can be produced by appropriately adopting a general film forming method as in the case of a resin sheet for a support. The structure of the release liner may be a single layer or a multilayer structure of two or more layers.
When the transfer method is employed as a method for providing the pressure-sensitive adhesive layer on the support, the same transfer sheet and release liner may be used. For example, a support is bonded to the pressure-sensitive adhesive layer formed on the release surface of the transfer sheet, the pressure-sensitive adhesive layer is transferred to the support, and this transfer sheet is left as it is on the pressure-sensitive adhesive layer and used as a release liner. can do. Thus, the mode in which the transfer sheet also serves as the release liner is preferable from the viewpoint of productivity improvement, material cost reduction, waste amount reduction, and the like.

  The thickness of the release liner is not particularly limited, and may be approximately 5 to 500 μm (for example, approximately 10 to 200 μm, typically approximately 20 to 200 μm). The release surface of the release liner (the surface disposed in contact with the adhesive surface) is subjected to a release treatment with a conventionally known release agent (for example, general silicone-based, long-chain alkyl-based, fluorine-based, etc.) as necessary. May be. The back surface of the release surface may be subjected to a release treatment, or may be subjected to a surface treatment other than the release treatment.

  Of the release liner, the arithmetic average surface roughness of the surface disposed on the pressure-sensitive adhesive layer is 0.05 to 0.75 μm (for example, approximately 0.05 to 0.5 μm, typically approximately 0. 1 to 0.3 μm) is preferable. Thereby, the smoothness of the pressure-sensitive adhesive surface (adhesive surface) can be kept high until the surface protective sheet is used. High smoothness of the pressure-sensitive adhesive surface is advantageous in preventing chemical solution from entering from the interface between the pressure-sensitive adhesive and the adherend. Moreover, it is preferable also from a viewpoint of adhesive residue prevention. For the same reason, in the surface protective sheet of the form that protects the adhesive surface until the use of the surface protective sheet by bringing the surface (adhesive surface) of the adhesive layer into contact with the back surface of the support, The arithmetic average surface roughness is preferably 0.05 to 0.75 μm (for example, approximately 0.05 to 0.5 μm, typically approximately 0.1 to 0.3 μm).

<Surface protection sheet>
The surface protective sheet of the present invention is preferably composed of the chemical treatment adhesive sheet. The said adhesive sheet can be used as a surface protection sheet for affixing on the desired site | part of a to-be-adhered body, and protecting the site | part. Since the pressure-sensitive adhesive used for the surface protective sheet has high adhesion to the adherend, a chemical solution (especially an aqueous chemical solution, typically acidic) is formed from the interface between the pressure-sensitive adhesive and the adherend at the outer edge of the surface protective sheet. It is excellent in performance to prevent the infiltration of the chemical solution. As a result, it is possible to reliably prevent the chemical solution from entering a region not intended to be exposed to the chemical solution and protect the surface.

  Taking advantage of such features, the surface protective sheet of the present invention is made of, for example, a glass solution for reducing the thickness of glass or removing burrs and microcracks formed on the cut end surface of glass. Etching process that dissolves in (etching liquid), etching process that partially corrodes metal surface with chemical liquid (etching liquid) for decoration and printability, circuit board (printed circuit board, flexible printed circuit board (FPC), etc.) Can be suitably used in a plating process or the like in which the connecting terminal portion or the like is partially plated with a chemical solution (plating solution).

  In addition, for example, when the surface protection sheet is attached to a range including the outer edge of the adherend and the chemical treatment is performed, the chemical liquid is partially discharged from the outer edge of the adherend (the outer edge of the region where the surface protection sheet is attached). If it penetrates, the smoothness of the outer edge (edge) of the adherend may be impaired due to the influence of the chemical solution. When the smoothness of the edge of the adherend is impaired, in particular, a brittle adherend such as a glass substrate may cause inconveniences such as a decrease in the strength of the adherend. Since the surface protection sheet disclosed here is excellent in the performance of preventing the chemical solution from entering from the outer edge of the surface protection sheet, it is possible to effectively prevent an event that the smoothness of the edge of the adherend is lowered.

<Glass substrate>
The glass substrate with a surface protective sheet of the present invention is preferably formed by attaching the surface protective sheet to a glass substrate. By sticking the surface protection sheet to a glass substrate, for example, the glass is treated with a chemical solution (strongly acidic chemical solution such as hydrofluoric acid) for adjusting the thickness of the glass or removing burrs formed on the cut end surface of the glass. The surface protective sheet has a property that prevents the chemical solution from entering the glass surface that does not require treatment with the chemical solution (chemical solution entry prevention property, sealing property), that is, adhesion. The property of closely adhering to the glass surface, which is a body (no floating or peeling, excellent adhesion), adhesive strength (excellent adhesive strength in chemicals), and the surface protection sheet are no longer necessary In that case, it has the property of being easily peeled off (removability), which is useful. In addition, since the surface protective sheet also has excellent antistatic properties, it suppresses static electricity generated on the glass surface as an adherend when the surface protective sheet is peeled off and removed when it is no longer needed. Can be useful. The glass substrate has a transparent conductive film (for example, ITO (indium tin oxide) film) or a flexible printed circuit board (FPC) partially on the surface, such as those used in tablet computers, mobile phones, and organic LEDs (light emitting diodes). It may be a glass substrate provided.

  Several examples relating to the present invention will be described below, but the present invention is not intended to be limited to the specific examples. In the following description, “part” and “%” are based on mass unless otherwise specified.

  The components of the pressure-sensitive adhesive compositions according to Examples 1 to 15 and Comparative Examples 1 and 2 are shown in Table 2, and the evaluation results are shown in Table 3.

The abbreviations in Table 2 indicate the following compounds, and the number of parts indicates parts by mass of solid content.
2EHA: 2-ethylhexyl acrylate HEA: 2-hydroxyethyl acrylate DCPMA: dicyclopentanyl methacrylate MMA: methyl methacrylate CHMA: cyclohexyl methacrylate BMP-TFSI: 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide EMI-FSI: 1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide KF6004: organopolysiloxane having a polyoxyalkylene chain Pluronic 25R-2: polyoxypropylene-polyoxyethylene-polyoxypropylene block copolymer Coronate L: Trimethylolpropane / tolylene diisocyanate trimer adduct Coronate HX: Isocyanine of hexamethylene diisocyanate Over door body

<Preparation of (meth) acrylic polymer (a) (2EHA / HEA = 96/4) as component (A)>
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, a condenser, and a dropping funnel, 96 parts by mass of 2-ethylhexyl acrylate (2EHA), 4 parts by mass of 2-hydroxyethyl acrylate (HEA) As a thermal polymerization initiator, 2,2′-azobisisobutyronitrile (0.2 parts by mass) and ethyl acetate (150 parts by mass) were charged, nitrogen gas was introduced with gentle stirring, and the liquid temperature in the flask was 65 ° C. The polymerization reaction was carried out for 6 hours while maintaining the vicinity to prepare a (meth) acrylic polymer (a) solution (40% by mass). The glass transition temperature (Tg) calculated from the Fox formula of this (meth) acrylic polymer (a) was −68 ° C., and the weight average molecular weight (Mw) was 550,000.

<Preparation of (meth) acrylic polymer 1 (DCPMA / MMA = 60/40) as component (B)>
100 parts by mass of ethyl acetate, 60 parts by mass of dicyclopentanyl methacrylate (DCPMA) (trade name: FA-513M, manufactured by Hitachi Chemical Co., Ltd.), 40 parts by mass of methyl methacrylate (MMA), and α-thioglycerol as a chain transfer agent 3.5 parts by mass were charged into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, a cooler, and a dropping funnel. Then, after stirring for 1 hour at 70 ° C. in a nitrogen atmosphere, 0.2 part by weight of 2,2′-azobisisobutyronitrile was added as a thermal polymerization initiator and reacted at 70 ° C. for 2 hours. And reacted at 80 ° C. for 5 hours. The glass transition temperature (Tg) calculated from the Fox formula of the obtained (meth) acrylic polymer 1 was 144 ° C., and the weight average molecular weight (Mw) was 4200.

<Preparation of (meth) acrylic polymer 2 (CHMA / MMA = 60/40) as component (B)>
100 parts by mass of ethyl acetate, 60 parts by mass of cyclohexyl methacrylate (CHMA), 40 parts by mass of methyl methacrylate (MMA), and 3.5 parts by mass of α-thioglycerol as a chain transfer agent, a stirring blade, a thermometer, a nitrogen gas introduction tube, A four-necked flask equipped with a condenser and a dropping funnel was charged. Then, after stirring for 1 hour at 70 ° C. in a nitrogen atmosphere, 0.2 part by weight of 2,2′-azobisisobutyronitrile was added as a thermal polymerization initiator and reacted at 70 ° C. for 2 hours. And reacted at 80 ° C. for 5 hours. The glass transition temperature (Tg) calculated from the Fox formula of the obtained (meth) acrylic polymer 2 was 81 ° C., and the weight average molecular weight (Mw) was 4100.

Example 1
(Preparation of adhesive composition)
The (meth) acrylic polymer 1 was added to 0.25 parts of the (meth) acrylic polymer (a) solution (40% by weight) diluted with toluene to 20% by weight (100 parts by weight of solid content). 1 part-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide (BMP-TFSI) (trade name: CIL-312, manufactured by Nippon Carlit Co., Ltd., liquid at 25 ° C.) 0.5 mass by mass, ionic compound Part, 0.05 part by mass of an organopolysiloxane having a polyoxyalkylene chain (trade name: KF6004, manufactured by Shin-Etsu Chemical Co., Ltd.) as a compound having a polyoxyalkylene chain, and coronate L (trimethylolpropane / tolylene) as a crosslinking agent Ethyl acetate solution of solid content of isocyanate trimer adduct 75% by mass, manufactured by Nippon Polyurethane Industry Co., Ltd.) Add 33 parts by mass (solid content 0.25 parts by mass), 3 parts by mass of 1% by weight ethyl acetate solution of dioctyltin dilaurate as a crosslinking catalyst, and mix and stir at 25 ° C. for about 5 minutes. Composition (1) was prepared.

(Preparation of adhesive sheet)
The pressure-sensitive adhesive composition (1) was applied to a corona-treated surface of a polyethylene film (trade name: NSO film, manufactured by Okura Kogyo Co., Ltd., thickness 150 μm, “PE # 150” in Table 3) as a support, Heating was performed at 80 ° C. for 1 minute to form an adhesive layer having a thickness of 25 μm. Next, a surface of the pressure-sensitive adhesive layer as a release liner was bonded to the surface opposite to the corona-treated surface of a polyethylene film (trade name: NSO film, manufactured by Okura Kogyo Co., Ltd., thickness: 150 μm) to prepare a pressure-sensitive adhesive sheet.

(Example 2)
(Preparation of adhesive composition)
Instead of using 0.25 part by mass of the (meth) acrylic polymer 1, the same procedure as in Example 1 was performed except that 0.15 part by mass of the (meth) acrylic polymer 1 was used. A pressure-sensitive adhesive composition (2) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (2) was used in place of the pressure-sensitive adhesive composition (1).

(Example 3)
(Preparation of adhesive composition)
It replaced with having used said (meth) acrylic-type polymer 1 0.25 mass part, and it carried out similarly to Example 1 except having used the said (meth) acrylic-type polymer 1 0.08 mass part. A pressure-sensitive adhesive composition (3) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (3) was used in place of the pressure-sensitive adhesive composition (1).

Example 4
(Preparation of adhesive composition)
Instead of using 0.33 parts by mass of Coronate L (trimethylolpropane / tolylene diisocyanate trimer adduct solid content 75% by mass ethyl acetate solution, manufactured by Nippon Polyurethane Industry Co., Ltd.), hexamethylene diisocyanate isocyanate A pressure-sensitive adhesive composition (4) was prepared in the same manner as in Example 1 except that 0.25 part by mass of a nurate body (trade name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.) was used.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (4) was used in place of the pressure-sensitive adhesive composition (1).

(Example 5)
(Preparation of adhesive composition)
Instead of using 0.5 parts by mass of the 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide (BMP-TFSI) (trade name: CIL-312, Nippon Carlit Co., Ltd., liquid at 25 ° C.) Example 4 except that 0.75 parts by mass of 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide (trade name: CIL-312, manufactured by Nippon Carlit Co., Ltd., liquid at 25 ° C.) was used. A pressure-sensitive adhesive composition (5) was prepared in the same manner as described above.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (5) was used in place of the pressure-sensitive adhesive composition (1).

(Example 6)
(Preparation of adhesive composition)
The compound having a polyoxyalkylene chain has a polyoxyalkylene chain instead of using 0.05 part by mass of an organopolysiloxane having a polyoxyalkylene chain (trade name: KF6004, manufactured by Shin-Etsu Chemical Co., Ltd.). A pressure-sensitive adhesive composition (6) in the same manner as in Example 4 except that 0.1 parts by mass of an organopolysiloxane having a polyoxyalkylene chain (trade name: KF6004, manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the compound. Was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (6) was used in place of the pressure-sensitive adhesive composition (1).

(Example 7)
(Preparation of adhesive composition)
Instead of using 0.33 parts by mass of Coronate L (trimethylolpropane / tolylene diisocyanate trimer adduct solid content 75% by mass ethyl acetate solution, manufactured by Nippon Polyurethane Industry Co., Ltd.), Coronate L (trimethylol) A pressure-sensitive adhesive composition (in the same manner as in Example 2 except that 0.67 parts by mass of a solid content 75 mass% ethyl acetate solution of propane / tolylene diisocyanate trimer adduct, manufactured by Nippon Polyurethane Industry Co., Ltd.) was used. 7) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (7) was used in place of the pressure-sensitive adhesive composition (1).

(Example 8)
(Preparation of adhesive composition)
Instead of using 0.33 parts by mass of Coronate L (trimethylolpropane / tolylene diisocyanate trimer adduct solid content 75% by mass ethyl acetate solution, manufactured by Nippon Polyurethane Industry Co., Ltd.), Coronate L (trimethylol) A pressure-sensitive adhesive composition (Example 3) except that 0.67 parts by mass of a solid content 75% by mass ethyl acetate solution of propane / tolylene diisocyanate trimer adduct was manufactured by Nippon Polyurethane Industry Co., Ltd. 8) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (8) was used in place of the pressure-sensitive adhesive composition (1).

Example 9
(Preparation of adhesive composition)
In the same manner as in Example 2, except that 0.15 parts by mass of (meth) acrylic polymer 1 was used instead of 0.15 parts by mass of (meth) acrylic polymer 1, adhesive was used. An agent composition (9) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (9) was used in place of the pressure-sensitive adhesive composition (1).

(Example 10)
(Preparation of adhesive composition)
In the same manner as in Example 3, except that 0.15 part by mass of (meth) acrylic polymer 1 was used and 0.08 part by mass of (meth) acrylic polymer 2 was used. An agent composition (10) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (10) was used in place of the pressure-sensitive adhesive composition (1).

(Example 11)
(Preparation of adhesive composition)
Instead of using 0.05 parts by mass of an organopolysiloxane having a polyoxyalkylene chain (trade name: KF6004, manufactured by Shin-Etsu Chemical Co., Ltd.) as the compound having a polyoxyalkylene chain, polyoxypropylene-polyoxy A pressure-sensitive adhesive composition (11) was prepared in the same manner as in Example 2 except that 0.1 part by mass of an ethylene-polyoxypropylene block copolymer (trade name: Pluronic 25R-2, manufactured by ADEKA) was used. did.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (11) was used in place of the pressure-sensitive adhesive composition (1).

(Example 12)
(Preparation of adhesive composition)
Instead of using 0.5 parts by mass of the 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide (BMP-TFSI) (trade name: CIL-312, Nippon Carlit Co., Ltd., liquid at 25 ° C.) Example 2 except that 0.5 parts by mass of 1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide (EMI-FSI) (Daiichi Kogyo Seiyaku Co., Ltd., IL-110) was used. In the same manner, a pressure-sensitive adhesive composition (12) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (12) was used in place of the pressure-sensitive adhesive composition (1).

(Example 13)
(Preparation of adhesive composition)
A pressure-sensitive adhesive composition (13) was prepared in the same manner as in Example 1 except that 0.25 part by mass of the (meth) acrylic polymer 1 was not used.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (13) was used instead of the pressure-sensitive adhesive composition (1).

(Example 14)
(Preparation of adhesive composition)
In place of using 0.25 part by mass of the (meth) acrylic polymer 1 and using 1.0 part by mass of the (meth) acrylic polymer 1, the adhesive was used in the same manner as in Example 1. An agent composition (14) was prepared.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (14) was used in place of the pressure-sensitive adhesive composition (1).

(Example 15)
(Preparation of adhesive sheet)
In place of the polyethylene film (trade name: NSO film, manufactured by Okura Kogyo Co., Ltd., thickness 150 μm), a polyethylene terephthalate film (trade name: Lumirror S-105, manufactured by Toray Film Processing Co., Ltd., thickness 75 μm, in Table 3) A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 7 except that it was applied to a corona-treated surface of “PET # 75” and heated at 80 ° C. for 1 minute to form a pressure-sensitive adhesive layer having a thickness of 20 μm.

(Comparative Example 1)
(Preparation of adhesive composition)
(Meth) acrylic polymer 1, 1-butyl-3-methylpyridinium bis (trifluoromethanesulfonyl) imide (trade name: CIL-312, Nippon Carlit Co., Ltd., liquid at 25 ° C.), polyoxyalkylene chain A pressure-sensitive adhesive composition (15) was prepared in the same manner as in Example 1 except that organopolysiloxane having a polyoxyalkylene chain (trade name: KF6004, manufactured by Shin-Etsu Chemical Co., Ltd.) was not used as the compound.

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (15) was used in place of the pressure-sensitive adhesive composition (1).

(Comparative Example 2)
(Preparation of adhesive composition)
Instead of using 0.25 parts by mass of the (meth) acrylic polymer 1, 0.15 parts by mass of the (meth) acrylic polymer 1 was used, and Coronate L (trimethylolpropane / trimethyl) as a crosslinking agent. Instead of 0.33 parts by mass of 75 mass% ethyl acetate solution of diisocyanate trimer adduct, manufactured by Nippon Polyurethane Industry Co., Ltd., isocyanurate of hexamethylene diisocyanate (trade name: Coronate HX, Nippon Polyurethane Industry Co., Ltd.) (Product made) Except having used 1.0 mass part, it carried out similarly to Example 1, and prepared the adhesive composition (16).

(Preparation of adhesive sheet)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (16) was used in place of the pressure-sensitive adhesive composition (1).

(Test method)
<Measurement of molecular weight>
The weight average molecular weight (Mw) of the polymer and the (meth) acrylic copolymer was measured using a GPC apparatus (manufactured by Tosoh Corporation, HLC-8220GPC). The measurement conditions were as follows, and the molecular weight was determined by standard polystyrene conversion.
Sample concentration: 0.2% by mass (tetrahydrofuran (THF) solution)
Sample injection volume: 10 μl
・ Eluent: THF
・ Flow rate: 0.6ml / min
・ Measurement temperature: 40 ℃
·column:
Sample column: TSKguardcolumn SuperHZ-H (1) + TSKgel SuperHZM-H (2)
Reference column: TSKgel SuperH-RC (1 piece)
・ Detector: Differential refractometer (RI)

<Measurement of solvent insoluble component ratio>
The solvent-insoluble component ratio (gel fraction) was determined by wrapping a measurement sample having a weight W1 in a porous sheet made of tetrafluoroethylene resin and immersing the sample in ethyl acetate at room temperature for 1 week, and then drying the measurement sample. The weight W2 of the dissolved component is measured, and W1 and W2 are expressed by the following formula:
It is calculated | required by substituting for a solvent insoluble component rate (gel fraction) [mass%] = W2 / W1 * 100 ;.
More specifically, the solvent-insoluble component ratio (gel fraction) can be measured by the following method. That is, about 0.1 g of a measurement sample is wrapped in a purse-like shape with a porous sheet made of tetrafluoroethylene resin having an average pore diameter of 0.2 μm, and the mouth is tied with a kite string. The total mass Wa (mg) of the tetrafluoroethylene resin porous sheet and the kite string is measured in advance. Then, the mass of the package (the total mass of the pressure-sensitive adhesive layer and the package) Wb (mg) is measured. Place this packet in a 50 mL screw tube (use one screw tube per packet) and fill the screw tube with ethyl acetate. This is left to stand at room temperature (typically 23 ° C.) for 7 days, then the packet is taken out and dried at 120 ° C. for 2 hours, and the mass Wc (mg) of the package after drying is measured. The solvent-insoluble component ratio (gel fraction) (% by mass) of the pressure-sensitive adhesive layer is determined by the following formula: Wa, Wb and Wc:
Solvent insoluble component ratio (gel fraction) [mass%] = (Wc−Wa) / (Wb−Wa) × 100;
As the porous sheet made of tetrafluoroethylene resin, a trade name “Nitoflon (registered trademark) NTF1122” manufactured by Nitto Denko Corporation can be used. In addition, the solvent insoluble component rate of the adhesive layer in this invention is 50-90 mass%, Preferably, it is 55-87 mass%, More preferably, it is 60-85 mass%. When the solvent-insoluble component ratio exceeds 90% by mass, the adhesive strength (adhesive strength) is reduced. is there. In addition, the evaluation method of a solvent insoluble component rate is measured according to the method and conditions described in the Example mentioned later.

<Measurement of (glue surface) surface resistivity>
After the pressure-sensitive adhesive sheet according to each example and comparative example was left in an environment of 23 ° C. × 50% RH for 2 hours, the separator was peeled off, and the surface resistivity of the pressure-sensitive adhesive surface (glue surface) was measured using a surface resistivity measuring device ( (Mitsubishi Chemical Corporation, Hiresta UP MCP-HT450 type). The applied voltage was 100 V and the application time was 30 seconds. In addition, the surface resistivity of the adhesive layer in the present invention is 10 ³ to 10 ¹³ Ω / □, preferably 10 ⁴ to 10 ¹³ Ω / □, and more preferably 10 ⁶ to 10 ¹³ Ω / □. It is. Within the above range, it is useful because it is possible to suppress the stripping voltage, that is, to impart antistatic properties.

<Adhesion reliability (constant load peel test)>
The pressure-sensitive adhesive sheet according to each example and comparative example was cut to a size of 10 mm in width and 60 mm in length, and the release liner was peeled off. The sample was pressure-bonded to the surface having a thickness of 100 mm and a thickness of 1.3 mm with a 2 kg hand roller to prepare an evaluation sample.
After the lamination, the laminate was left for 30 minutes in an environment of 23 ° C. × 50% RH, and then a constant load (3 g) was fixed to one end of the pressure-sensitive adhesive sheet 1. The tape sample was started to peel off at a constant load so that the peeling angle was 90 °. A length of 10 mm was used as an extra length, and the time until all the remaining 50 mm length was peeled was measured. The measurement was performed in an environment of 23 ° C. × 50% RH.
In the present invention, the case where the peeling time under a constant load is 2 minutes or more is good, and the case where the peeling time is less than 2 minutes is bad. If the peeling time is 2 minutes or longer, it is useful because it has adhesiveness (adhesiveness) that can prevent the infiltration of the chemical solution.

<Measurement of peeling voltage>
The pressure-sensitive adhesive sheet 1 is cut into a size of 70 mm in width and 120 mm in length, the release liner is peeled off, and then the glass 20 (trade name “MICROSLIDE GLASS, manufactured by Matsunami Glass Co., Ltd., width: 70 mm, long) is previously removed. (A thickness: 100 mm, a thickness: 1.3 mm) was crimped with a hand roller so that one end protruded 20 mm.

  After being left for one day in an environment of 23 ° C. × 50% RH, the sample is set at a predetermined position on the sample fixing base 30 as shown in FIG. One end protruding 20 mm is fixed to an automatic winder and peeled so that the peel angle is 150 ° and the tensile speed is 10 m / min. The potential of the surface of the glass 20 generated at this time was measured with a potential measuring device 40 (KSD-0103, manufactured by Kasuga Denki Co., Ltd.) fixed at a predetermined position, and used as the value of the stripping voltage. The measurement was performed in an environment of 23 ° C. × 50% RH. In addition, as a peeling band voltage, it is preferable that an absolute value is 1.0 kV or less, and it is more preferable that it is 0.9 kV or less. If it is within the above range, dust collection due to static electricity and prevention of static electricity damage can be prevented, which is useful.

注）表３中の「ＯＶＥＲ」とは、検出限界を超えて（１０^１３Ω／□を超えて）、測定不能であることを意味する。

Note) “OVER” in Table 3 means that the measurement limit is exceeded (over 10 ¹³ Ω / □) and measurement is impossible.

  As shown in Table 3, in all examples, the solvent-insoluble component ratio and the surface resistivity of the pressure-sensitive adhesive layer are included in a desired range, and the stripping voltage can be suppressed, that is, the antistatic property is excellent. It was confirmed that the adhesive reliability was excellent, that is, the chemical solution intrusion prevention property was also excellent.

On the other hand, in Comparative Example 1, the surface resistivity exceeds 10 ¹³ Ω / □, the stripping voltage cannot be sufficiently suppressed, and it is confirmed that the antistatic property is inferior. Comparative Example 2 is a solvent-insoluble component of the pressure-sensitive adhesive layer. It was confirmed that the rate exceeded 90% by mass, the adhesion reliability was not sufficient, and the chemical solution penetration prevention property was inferior.

DESCRIPTION OF SYMBOLS 1 Support body 2 Adhesive layer 3 Release liner 4 Antistatic layer 10 Adhesive sheet (surface protection sheet)
20 Glass 30 Sample fixing base 40 Potential measurement

Claims (22)

A pressure-sensitive adhesive layer for chemical treatment formed from a pressure-sensitive adhesive composition containing a polymer (A) having a glass transition temperature of less than 0 ° C,
A pressure-sensitive adhesive layer for chemical treatment, having a solvent-insoluble component ratio of 50 to 90% by mass and a surface resistivity of 10 ³ to 10 ¹³ Ω / □. The pressure-sensitive adhesive composition has a weight average molecular weight of 1000 or more and less than 30000, and includes a (meth) acrylic monomer having a (meth) acrylic monomer having an alicyclic structure represented by the following general formula (1) as a monomer component. The adhesive layer for chemical treatment according to claim 1, comprising a coalescence (B).
CH ₂ = C (R ¹ ) COOR ² (1)
[In Formula (1), R ¹ is a hydrogen atom or a methyl group, and R ² is an alicyclic hydrocarbon group having an alicyclic structure. ]   The said adhesive composition contains an ionic compound (C), The adhesive layer for chemical | medical solution processing of Claim 1 or 2 characterized by the above-mentioned.   The said adhesive composition contains the compound (D) which has a polyoxyalkylene chain, The adhesive layer for chemical | medical solution processing of any one of Claims 1-3 characterized by the above-mentioned.   The pressure-sensitive adhesive composition contains 0.005 to 2 parts by mass of the (meth) acrylic polymer (B) with respect to 100 parts by mass of the polymer (A). The adhesive layer for chemical | medical solution processing of any one of these.   The said adhesive composition contains 0.005-2 mass parts of said ionic compounds (C) with respect to 100 mass parts of said polymers (A), The any one of Claims 3-5 characterized by the above-mentioned. The adhesive layer for chemical | medical solution processing as described in a term.   The said adhesive composition contains 0.005-1 mass part of compounds (D) which have the said polyoxyalkylene chain with respect to 100 mass parts of said polymers (A). The adhesive layer for chemical | medical solution processing of any one of these.   The said polymer (A) is a (meth) acrylic-type polymer (a), The adhesive layer for chemical | medical solution processing of any one of Claims 1-7 characterized by the above-mentioned.   The adhesive for chemical treatment according to any one of claims 2 to 8, wherein the alicyclic hydrocarbon group of the (meth) acrylic monomer having an alicyclic structure has a bridged ring structure. Agent layer.   The pressure-sensitive adhesive layer for chemical treatment according to any one of claims 2 to 9, wherein the glass transition temperature of the (meth) acrylic polymer (B) is 0 to 300 ° C.   The pressure-sensitive adhesive layer for chemical treatment according to any one of claims 3 to 10, wherein the ionic compound (C) is an alkali metal salt and / or an ionic liquid.   The pressure-sensitive adhesive layer for chemical treatment according to claim 11, wherein the alkali metal salt is a lithium salt.   The pressure-sensitive adhesive layer for chemical treatment according to claim 11, wherein the ionic liquid is any one of a nitrogen-containing onium salt, a sulfur-containing onium salt, and a phosphorus-containing onium salt. The said ionic liquid contains the 1 or more types of cation represented by the following general formula (C1)-(C5), The adhesive layer for chemical | medical solution processing of Claim 11 or 13 characterized by the above-mentioned.

[R _a in Formula (C1) represents a hydrocarbon group having 4 to 20 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom, and R _b and R _c May be the same or different and each represents hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and a part of the hydrocarbon group may be a functional group substituted with a hetero atom. However, when the nitrogen atom contains a double bond, there is no R _c . ]
[R _d in Formula (C2) represents a hydrocarbon group having 2 to 20 carbon atoms, and may be a functional group in which a part of the hydrocarbon group is substituted with a hetero atom, and R _e , R _f And R _g may be the same or different and each represents hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and a part of the hydrocarbon group may be a functional group substituted with a hetero atom. ]
[R _h in the formula (C3) represents a hydrocarbon group having from 2 to 20 carbon atoms, a part of the hydrocarbon group may be substituted by a functional group with a hetero atom, R _i, R _j , And R _k may be the same or different and each represents hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and a part of the hydrocarbon group may be a functional group substituted with a hetero atom. ]
[Z in Formula (C4) represents a nitrogen, sulfur, or phosphorus atom, and R ₁ , R _m , R _n , and R _o are the same or different and each represents a hydrocarbon group having 1 to 20 carbon atoms. A functional group in which a part of the hydrocarbon group is substituted with a hetero atom may be used. However, when Z is a sulfur atom, there is no _Ro . ]
[R _P in the formula (C5) represents a hydrocarbon group having 1 to 18 carbon atoms, a part of the hydrocarbon group may be substituted by a functional group with a heteroatom. ]   The pressure-sensitive adhesive layer for chemical treatment according to claim 4, wherein the compound (D) having a polyoxyalkylene chain is an organopolysiloxane having a polyoxyalkylene chain. The pressure-sensitive adhesive layer for chemical treatment according to claim 15, wherein the organopolysiloxane having a polyoxyalkylene chain is an organopolysiloxane represented by the following general formulas (D1) to (D3).

[R ₁ in the formula (D1) is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is hydrogen or an organic group, m and n are integers of 0 to 1000. However, m and n are not 0 at the same time. a and b are integers of 0 to 1000. However, a and b are not 0 at the same time. ]
[R ₁ in the formula (D2) is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is hydrogen or an organic group, and m is an integer of 1 to 2000. a and b are integers of 0 to 1000. However, a and b are not 0 at the same time. ]
[In Formula (D3), R ₁ is a monovalent organic group, R ₂ , R ₃ and R ₄ are alkylene groups, R ₅ is hydrogen or an organic group, and m is an integer of 1 to 2000. a and b are integers of 0 to 1000. However, a and b are not 0 at the same time. ]   The pressure-sensitive adhesive layer for chemical treatment according to any one of claims 8 to 16, comprising a hydroxyl group-containing monomer as a monomer component constituting the (meth) acrylic polymer (a).   5.0% by mass or less of an alkylene oxide group-containing reactive monomer having an average addition mole number of oxyalkylene units of 3 to 40 with respect to the total amount of monomer components constituting the (meth) acrylic polymer (a) The adhesive layer for chemical | medical solution processing of any one of Claims 8-17 characterized by the above-mentioned.   A pressure-sensitive adhesive sheet for chemical treatment, comprising the pressure-sensitive adhesive layer according to any one of claims 1 to 18 formed on at least one side of a support.   The pressure-sensitive adhesive sheet for chemical treatment according to claim 19, wherein the support is a plastic film subjected to antistatic treatment.   21. A surface protective sheet comprising the chemical treatment adhesive sheet according to claim 19 or 20.   A glass substrate with a surface protective sheet, wherein the surface protective sheet according to claim 21 is adhered to a glass substrate.

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