Adhesive composition, adhesive sheet, and optical member

Abstract

The invention relates to an adhesive composition, an adhesive sheet and an optical member. The invention provides an adhesive composition, an adhesive sheet formed by the adhesive composition, and an optical member to which the adhesive sheet is adhered. The adhesive composition is not liable to slide (shift), tilt or peel off from an optical member such as a polarizing plate, is excellent in curl adjustability, and is capable of suppressing a peeling voltage to be low. The invention also provides an optical member to which the adhesive sheet is adhered. This adhesive composition is characterized by containing an adhesive polymer, a fluorine-containing oligomer having a weight-average molecular weight of 3500 or more, and an ionic compound.

Description

[0001] The present application is a divisional application of a Chinese patent application filed on December 28, 2017, with application number 201711458968.9 and the invention title being Adhesive Composition, Adhesive Sheet, and Optical Component. Technical Field

[0002] The present invention relates to an adhesive composition, an adhesive sheet, and an optical component. In particular, the adhesive sheet obtained from the adhesive composition is suitable for being attached to plastic products that easily generate static electricity (such as liquid crystal display panels, plasma display panels (PDPs), organic electroluminescent (EL) displays, etc.), and is particularly useful as a surface protective film used for the purpose of protecting the surface of optical components (such as polarizing plates, wave plates, phase difference plates, optical compensation films, reflective sheets, brightness enhancement films used in liquid crystal displays, etc.). Background Art

[0003] Surface protection film (also referred to as surface protection sheet) generally has a structure in which an adhesive layer is provided on a film-like base film (support). The protective film is attached to an adherend (protected body) via the above-mentioned adhesive layer, thereby protecting the adherend from damage or stains during processing, transportation, etc. For example, the panel of a liquid crystal display is formed by attaching optical components such as a polarizing plate and a wave plate to a liquid crystal cell via an adhesive layer. In the manufacture of the liquid crystal display panel, the polarizing plate attached to the liquid crystal cell is first manufactured into a roll form, then unwound from the roll, and cut into the desired size corresponding to the shape of the liquid crystal cell for use. Here, in order to prevent the polarizing plate from being damaged by friction with a conveying roller or the like in an intermediate process, a countermeasure of attaching a surface protective film to one or both sides (typically one side) of the polarizing plate is taken. The surface protective film will be peeled off and removed at the stage where the surface protective film is no longer needed.

[0004] Typically, since the surface protection film and the optical component are made of plastic materials, the electrical insulation is high, and static electricity is generated due to friction and peeling. Therefore, when the surface protection film is peeled off from an optical component such as a polarizing plate, static electricity is also easily generated. When a voltage is applied to the liquid crystal directly in a state where the static electricity remains, there is a concern that the orientation of the liquid crystal molecules is lost or a defect in the panel is generated. In addition, the presence of static electricity may also become a factor that attracts dust or reduces workability. Based on the above situation, an operation of applying an antistatic treatment to the surface protection film is performed, for example, by forming an antistatic layer or applying an antistatic coating as a surface layer (topcoat layer, back layer) of the surface protection film, thereby imparting an antistatic function (see patent documents 1 and 2).

[0005] In order to impart antistatic properties to the adhesive layer itself constituting the surface protective film, an ionic compound such as an alkali metal salt or an ionic liquid that functions as an antistatic agent has been incorporated into the adhesive (see Patent Document 3).

[0006] Furthermore, the surface protective film is required to have curl control properties so that when it is attached to an adherend (polarizing plate, etc.), unwanted or unintended curling (curling refers to the phenomenon of warping, such as the phenomenon of overall warping on any one side of a flat plate-like object, or the phenomenon of the entire flat plate-like object warping in an undulating manner, etc.) is prevented. If unwanted or unintended curling occurs, workability is poor, and for example, air bubbles may be trapped when attaching an adherend such as a polarizing plate to a liquid crystal cell.

[0007] When curling occurs in a flat adherend, a force accompanying the curling acts in the shear direction in the adhesive layer of the surface protective film attached to the adherend, and this force gradually causes sliding (deviating) between the adherend and the adhesive layer. Therefore, it is required to increase the shear force during low-speed peeling.

[0008] Furthermore, in order to prevent the surface protective film from lifting or peeling during processing and transportation of the adherend (protected object), it is required to have appropriate adhesive strength and easy peelability (repeelability) when peeled at a low speed.

[0009] Therefore, various methods have been implemented for adhesive compositions used in surface protective films to achieve easy peeling. For example, there are reports of adding components with high glass transition temperatures (Tg) or reactive surfactants to the polymers used in adhesive compositions, and of highly crosslinking the adhesive compositions (e.g., see Patent Document 4).

[0010] However, even when easy peeling is achieved in the above method, the presence of additives such as ionic compounds and surfactants may cause the additives to seep out at the interface between the adhesive layer and the adherend, resulting in contamination and the possibility of slippage (drift).

[0011] Prior art literature

[0012] Patent Literature

[0013] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-223923

[0014] Patent Document 2: Japanese Patent Application Laid-Open No. 2008-255332

[0015] Patent Document 3: Japanese Patent Application Laid-Open No. 9-165460

[0016] Patent Document 4: Japanese Patent Application Laid-Open No. 2002-221906 Summary of the Invention

[0017] Problems to be solved by the invention

[0018] Therefore, in the present invention, in-depth research was conducted in view of the above situation, and the purpose of the present invention is to provide an adhesive composition that can obtain an adhesive layer or adhesive sheet that is not prone to sliding (deviating), warping, peeling, and has excellent curling adjustability on optical components such as polarizing plates, and can suppress the peeling voltage to a low level, an adhesive sheet formed from the above adhesive composition, and an optical component to which the above adhesive sheet is attached.

[0019] Means for solving problems

[0020] That is, the adhesive composition of the present invention is characterized by containing an adhesive polymer, a fluorinated oligomer having a weight average molecular weight of 3500 or more, and an ionic compound.

[0021] The adhesive composition of the present invention preferably contains an oxyalkylene group-containing compound.

[0022] In the adhesive composition of the present invention, it is preferred that the adhesive polymer be at least one selected from the group consisting of (meth)acrylic polymers, polyurethane polymers, and polysiloxane polymers.

[0023] The pressure-sensitive adhesive sheet of the present invention preferably comprises a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition on at least one surface of a substrate film, and the fluorinated oligomer is present within and / or on the surface of the pressure-sensitive adhesive layer.

[0024] The pressure-sensitive adhesive sheet of the present invention preferably has a separator attached to the surface of the pressure-sensitive adhesive layer opposite to the surface in contact with the base film.

[0025] In the pressure-sensitive adhesive sheet of the present invention, the fluorinated oligomer is preferably present on the surface of the separator in contact with the pressure-sensitive adhesive layer.

[0026] The optical member of the present invention is preferably a member having the pressure-sensitive adhesive sheet adhered thereto, or a pressure-sensitive adhesive sheet obtained by peeling the separator from the pressure-sensitive adhesive sheet.

[0027] Effects of the Invention

[0028] The present invention uses an adhesive composition containing a specific fluorine-containing oligomer and an ionic compound. After an adhesive sheet having an adhesive layer formed from the above-mentioned adhesive composition is adhered to an optical component such as a polarizing plate, the occurrence of slippage (offset), warping, and peeling can be suppressed. Therefore, the curling adjustability is excellent and the peeling voltage can be suppressed to a low level, which is useful. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic cross-sectional view showing one structural example of the pressure-sensitive adhesive sheet (surface protection film) of the present invention.

[0030] Figure 2 This is an explanatory diagram showing a method for measuring the peeling voltage.

[0031] Reference numerals

[0032] 1: Adhesive sheet

[0033] 10: Glass pane

[0034] 11: Spacer

[0035] 12: Fluorine-containing oligomer coating

[0036] 13: Adhesive layer

[0037] 14: Base film

[0038] 20: Polarizing plate

[0039] 30: Sample fixing table

[0040] 40: Potentiometer DETAILED DESCRIPTION

[0041] Hereinafter, embodiments of the present invention will be described in detail.

[0042] <Overall structure of adhesive sheet (surface protection film)>

[0043] The adhesive sheet disclosed herein is an object in the form of an adhesive tape, adhesive label, adhesive film, etc., and is particularly suitable as a surface protective film for protecting the surface of an optical component (e.g., an optical component used as a component of a liquid crystal display panel such as a polarizing plate or wave plate) during processing or transportation. The adhesive layer in the surface protective film is typically formed continuously, but is not limited to this form. For example, the adhesive layer can be formed into a regular or random pattern such as dots or stripes. In addition, the surface protective film disclosed herein can be in a roll form or a sheet form (leaf form).

[0044] <Base film>

[0045] The adhesive sheet (surface protection film) of the present invention is characterized in that it has a substrate film. In the technology disclosed herein, the resin material constituting the substrate film can be used without particular restriction, preferably using a resin material having excellent properties such as transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, flexibility, dimensional stability. In particular, by making the substrate film have flexibility, it is possible to utilize a coating adhesive composition such as a roll coater, and it is possible to be wound into a roll shape, which is useful.

[0046] As the substrate film (substrate, support), a plastic film composed of a resin material having as its main resin component (the main component of the resin component, typically a component accounting for 50% or more by mass) polyester polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate; cellulose polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate polymers; acrylic polymers such as polymethyl methacrylate; etc. can be preferably used as the substrate film. Other examples of the resin material include styrene polymers such as polystyrene and acrylonitrile-styrene copolymer; olefin polymers such as polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, and ethylene-propylene copolymer; vinyl chloride polymers; amide polymers such as nylon 6, nylon 6,6, and aromatic polyamide; etc. Other examples of the resin material include imide polymers, sulfone polymers, polyethersulfone polymers, polyetheretherketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, and epoxy polymers. The base film may also be a blend of two or more of the above polymers.

[0047] As the substrate film, a plastic film made of a transparent thermoplastic resin material can be preferably used. Among the above plastic films, the use of a polyester film is a more preferred embodiment. Here, a polyester film refers to a film whose main resin component is a polyester polymer material (polyester resin) having a main skeleton based on ester bonds, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate. Such polyester films have excellent optical properties and dimensional stability, making them suitable as substrate films for surface protection films. On the other hand, reduced forms are susceptible to electrical charges.

[0048] The resin material constituting the substrate film may be mixed with various additives such as antioxidants, ultraviolet absorbers, plasticizers, and colorants (pigments, dyes, etc.) as needed. For example, the substrate film may be subjected to known or customary surface treatments such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, and application of a primer. Such surface treatments may be, for example, treatments to improve the adhesion between the substrate film and the adhesive layer (ie, the anchoring properties of the adhesive layer).

[0049] The adhesive sheet (surface protection film) of the present invention can also use a plastic film that has been subjected to an antistatic treatment as the above-mentioned base film. By using the above-mentioned base film, the electrification of the adhesive sheet itself during peeling can be suppressed, so it is preferred. In addition, the base film is a plastic film, and by applying an antistatic treatment to the above-mentioned plastic film, the electrification of the adhesive sheet itself can be reduced and a base film having excellent antistatic ability to the adherend can be obtained. It should be noted that, as a method for imparting an antistatic function, there is no particular limitation, and existing well-known methods can be used, for example: a method of applying an antistatic resin comprising an antistatic agent and a resin component or a conductive resin containing a conductive polymer or a conductive substance; a method of evaporating or plating a conductive substance; and a method of kneading an antistatic agent, etc.

[0050] The thickness of the substrate film is generally about 5 μm to about 200 μm, preferably about 10 μm to about 100 μm. A thickness within the above range is preferred because it is easy to attach to and remove from an adherend.

[0051] The PSA sheet disclosed herein may also be implemented in an embodiment including other layers in addition to the base film and the PSA layer. Examples of such other layers include a primer layer (anchor layer) that improves the anchoring properties of the antistatic layer or the PSA layer.

[0052] <Adhesive composition>

[0053] The adhesive composition of the present invention can be used without particular limitation as long as it is an adhesive composition containing an adhesive polymer having adhesive properties, and an adhesive layer can be formed from the above-mentioned adhesive composition. As the above-mentioned adhesive composition, for example, acrylic adhesives, polyurethane adhesives, synthetic rubber adhesives, natural rubber adhesives, polysiloxane adhesives, etc. can also be used. Among them, it is more preferred that the above-mentioned adhesive polymer is at least one selected from the group consisting of (meth) acrylic polymers, polyurethane polymers and polysiloxane polymers. It is further preferred to use (contain) at least one selected from the group consisting of acrylic adhesives containing (meth) acrylic polymers, polyurethane adhesives containing polyurethane polymers and polysiloxane polymers. It is particularly preferred to use an acrylic adhesive using a (meth) acrylic polymer as the above-mentioned adhesive polymer.

[0054] In the case of using an acrylic adhesive in the adhesive layer, as for the (meth)acrylic polymer that is the adhesive polymer constituting the acrylic adhesive, as the raw material monomer constituting the (meth)acrylic monomer, a (meth)acrylic monomer having an alkyl group with 1 to 14 carbon atoms can be used as the main monomer. As the (meth)acrylic monomer, one or more than two can be used. By using the (meth)acrylic monomer having an alkyl group with 1 to 14 carbon atoms, it is easy to control the peeling force (adhesive force) to the adherend (protected body) to be low, and an adhesive sheet (surface protective film) with excellent light peeling and re-peeling properties can be obtained. It should be noted that the (meth)acrylic polymer in the present invention refers to an acrylic polymer and / or a methacrylic polymer, and the (meth)acrylate refers to an acrylate and / or a methacrylate.

[0055] Specific examples of the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, and n-tetradecyl (meth)acrylate.

[0056] When the adhesive sheet of the present invention is used as a surface protective film, suitable raw material monomers include (meth)acrylic acid monomers having an alkyl group having 4 to 14 carbon atoms, such as n-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, and n-tetradecyl (meth)acrylate. In particular, by using a (meth)acrylic acid monomer having an alkyl group having 4 to 14 carbon atoms, it is easy to control the peel force (adhesive force) to the adherend to be low, resulting in an adhesive sheet with excellent removability.

[0057] In particular, the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms is preferably present in an amount of 50% by mass or more, more preferably 80% by mass or more, further preferably 85% to 99.9% by mass, and most preferably 90% to 99% by mass, relative to 100% by mass of the total monomer components constituting the (meth)acrylic polymer. A content of less than 50% by mass is undesirable because it impairs the proper wettability of the adhesive composition or the cohesive strength of the adhesive layer.

[0058] In the adhesive composition of the present invention, the (meth)acrylic polymer preferably contains a hydroxyl group-containing (meth)acrylic monomer as a raw material monomer. One or more hydroxyl group-containing (meth)acrylic monomers may be used. The use of hydroxyl group-containing (meth)acrylic monomers facilitates control of crosslinking and other properties of the adhesive composition, thereby facilitating balance between improved wettability due to flow and reduced peel strength (adhesive strength) during peeling.

[0059] Examples of the hydroxyl group-containing (meth)acrylic acid monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl acrylate, and N-hydroxymethyl (meth)acrylamide. In particular, the use of a hydroxyl group-containing (meth)acrylic acid monomer having an alkyl group with 4 or more carbon atoms facilitates easy peeling during high-speed peeling, which is preferred.

[0060] The hydroxyl group-containing (meth)acrylic monomer is preferably contained in an amount of 25% by mass or less, more preferably 20% by mass or less, further preferably 0.1% to 15% by mass, and most preferably 1% to 10% by mass, relative to 100% by mass of the total amount of monomer components constituting the (meth)acrylic polymer. The above-mentioned range is preferred because it facilitates the balance between the wettability of the adhesive composition and the cohesive force of the resulting adhesive layer.

[0061] Furthermore, as other polymerizable monomer components, from the perspective of easily achieving a balance in adhesive properties, polymerizable monomers for adjusting the glass transition temperature and releasability of the (meth)acrylic polymer may be used within a range that does not impair the effects of the present invention so as to achieve a Tg of 0°C or lower (generally -100°C or higher).

[0062] As other polymerizable monomers used in the (meth)acrylic polymer, in addition to the (meth)acrylic monomer having an alkyl group with 1 to 14 carbon atoms and the hydroxyl group-containing (meth)acrylic monomer, a carboxyl group-containing (meth)acrylic monomer can be used. The use of such a carboxyl group-containing (meth)acrylic monomer can suppress the increase in adhesive strength of the adhesive layer (adhesive sheet) over time, resulting in excellent removability, resistance to increase in adhesive strength, and workability. Furthermore, the adhesive layer exhibits excellent cohesive strength and shear strength, making it preferable.

[0063] Examples of the carboxyl group-containing (meth)acrylic monomer include (meth)acrylic acid, carboxyethyl (meth)acrylate, and carboxypentyl (meth)acrylate.

[0064] The amount of the carboxyl group-containing (meth)acrylic monomer is preferably 0 to 5 mass%, more preferably 0 to 3 mass%, even more preferably 0 to 2 mass%, and most preferably 0 to 1 mass%, relative to 100 mass% of the total amount of monomer components constituting the (meth)acrylic polymer. Within this range, the balance between the wettability of the adhesive composition and the cohesive force of the resulting adhesive layer can be easily controlled, which is preferred.

[0065] When the hydroxyl group-containing (meth)acrylic monomer and the carboxyl group-containing (meth)acrylic monomer are used in combination, the carboxyl group-containing (meth)acrylic monomer is preferably contained in an amount of 0.005% to 0.1% by mass relative to 100% by mass of the total monomer components constituting the (meth)acrylic polymer. Adjusting the amount within this range effectively yields a PSA layer (PSA sheet) with improved removability and resistance to increased adhesive strength.

[0066] In addition, as for other polymerizable monomers other than the (meth) acrylic monomers having an alkyl group with 1 to 14 carbon atoms, hydroxyl group-containing (meth) acrylic monomers and carboxyl group-containing (meth) acrylic monomers used in the above-mentioned (meth) acrylic polymers, as long as they are within the range that does not damage the characteristics of the present invention, they can be used without particular limitation. For example, components that improve cohesion and heat resistance such as cyano group-containing monomers, vinyl ester monomers, aromatic vinyl monomers, etc.; components that improve peeling force (adhesion force) or have functional groups that act as crosslinking bases such as amide group-containing monomers, imide group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, N-acryloylmorpholine, vinyl ether monomers, etc. can be appropriately used. Among them, nitrogen-containing monomers such as cyano group-containing monomers, amide group-containing monomers, imide group-containing monomers, amino group-containing monomers and N-acryloylmorpholine are preferably used. By using nitrogen-containing monomers, it is possible to ensure appropriate peeling force (adhesion force) without warping or peeling, and further, an adhesive sheet (surface protective film) with excellent shear force can be obtained, so it is useful. These polymerizable monomers can be used alone or in combination.

[0067] Examples of the cyano group-containing monomer include acrylonitrile and methacrylonitrile.

[0068] Examples of the amide group-containing monomer include acrylamide, methacrylamide, diethylacrylamide, N-vinyl pyrrolidone, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N,N'-methylenebisacrylamide, N,N-dimethylaminopropylacrylamide, N,N-dimethylaminopropylmethacrylamide, and diacetoneacrylamide.

[0069] Examples of the imide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, and itaconimide.

[0070] Examples of the amino group-containing monomer include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and N,N-dimethylaminopropyl (meth)acrylate.

[0071] Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, and vinyl laurate.

[0072] Examples of the aromatic vinyl monomer include styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene, and other substituted styrenes.

[0073] Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, and allyl glycidyl ether.

[0074] Examples of the vinyl ether monomer include methyl vinyl ether, ethyl vinyl ether, and isobutyl vinyl ether.

[0075] In the present invention, the amount of other polymerizable monomers other than the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, the hydroxyl group-containing (meth)acrylic monomer, and the carboxyl group-containing (meth)acrylic monomer is preferably 0 to 50% by mass, more preferably 0 to 20% by mass, relative to 100% by mass of the total amount of monomer components constituting the (meth)acrylic polymer. The amount of other polymerizable monomers may be appropriately adjusted to obtain desired properties.

[0076] The (meth)acrylic polymer may further contain an alkylene oxide group-containing reactive monomer as a monomer component.

[0077] In addition, the average addition mole number of the oxyalkylene unit as the reactive monomer containing the alkylene oxide group is preferably 1 to 40, more preferably 3 to 40, further preferably 4 to 35, and particularly preferably 5 to 30 from the viewpoint of compatibility with the compound containing the oxyalkylene. When the average addition mole number is 1 or more, there is a tendency to efficiently obtain the effect of reducing the contamination of the adherend (protected body). In addition, when the average addition mole number is greater than 40, the interaction with the compound containing the oxyalkylene is large, and there is a tendency that the viscosity of the adhesive composition increases and becomes difficult to apply, and therefore it is not preferred. It should be noted that the end of the oxyalkylene chain may be a hydroxyl group itself, or may be substituted by other functional groups.

[0078] The alkylene oxide group-containing reactive monomer may be used alone or in combination of two or more. The total content of the alkylene oxide group-containing reactive monomer is preferably 0 to 20% by mass, more preferably 0 to 10% by mass, based on the total amount of monomer components in the (meth)acrylic polymer. An alkylene oxide group-containing reactive monomer content exceeding 20% by mass is not preferred because it deteriorates the staining properties of the adherend.

[0079] Examples of the oxyalkylene units of the reactive monomer containing an alkylene oxide group include units having an alkylene group having 1 to 6 carbon atoms, such as oxymethylene, oxyethylene, oxypropylene, and oxybutylene. The hydrocarbon group of the oxyalkylene chain may be linear or branched.

[0080] Furthermore, the reactive monomer containing an alkylene oxide group is more preferably a reactive monomer containing an ethylene oxide group. By using a (meth)acrylic polymer containing a reactive monomer containing an ethylene oxide group as the base polymer, the compatibility of the base polymer with fluorinated oligomers, ionic compounds, and oxyalkylene-containing compounds is improved, and bleeding into the adherend is preferably suppressed, resulting in a low-staining adhesive composition.

[0081] Examples of the alkylene oxide group-containing reactive monomer include (meth)acrylic acid alkylene oxide adducts and reactive surfactants having a reactive substituent such as an acryloyl group, a methacryloyl group, or an allyl group in the molecule.

[0082] Specific examples of the (meth)acrylic acid alkylene oxide adducts include 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, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, butoxypolyethylene glycol (meth)acrylate, octyloxypolyethylene glycol (meth)acrylate, laurylpolyethylene glycol (meth)acrylate, stearylpolyethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and octyloxypolyethylene glycol-polypropylene glycol (meth)acrylate.

[0083] Specific examples of the reactive surfactant include anionic reactive surfactants, nonionic reactive surfactants, and cationic reactive surfactants having a (meth)acryloyl group or an allyl group.

[0084] For the above-mentioned (meth) acrylic polymer, the preferred weight average molecular weight (Mw) is 100,000 to 5,000,000, more preferably 200,000 to 4,000,000, further preferably 300,000 to 3,000,000, and most preferably 300,000 to 950,000. When the weight average molecular weight is less than 100,000, there is a tendency for the adhesive to remain due to the decrease in the cohesive force of the adhesive layer. On the other hand, when the weight average molecular weight exceeds 5,000,000, the fluidity of the polymer decreases, and there is a tendency for the wettability to the adherend (such as a polarizing plate) to become insufficient, and to become the cause of the ridges generated between the adherend and the adhesive layer of the adhesive sheet (surface protective film). It should be noted that the weight average molecular weight refers to the weight average molecular weight measured using GPC (gel permeation chromatography).

[0085] In addition, the glass transition temperature (Tg) of the above-mentioned (meth) acrylic polymer is preferably 0°C or less, more preferably -10°C or less (usually -100°C or more). When the glass transition temperature is higher than 0°C, the polymer is not easy to flow, and for example, there is a tendency that the wetting of the polarizing plate as an optical component is insufficient, which becomes the cause of bulges between the polarizing plate and the adhesive layer of the adhesive sheet (surface protective film). In particular, by adjusting the glass transition temperature to -61°C or less, it is easy to obtain an adhesive layer with excellent wettability and easy peelability to the polarizing plate. It should be noted that the glass transition temperature of the (meth) acrylic polymer can be adjusted to the above range by appropriately changing the monomer components and composition ratios used.

[0086] The polymerization method for the (meth)acrylic polymer is not particularly limited and can be carried out by known methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. However, solution polymerization is particularly preferred from the perspectives of workability and low contamination to the adherend (protected object). The resulting polymer may be any of a random copolymer, a block copolymer, an alternating copolymer, and a graft copolymer.

[0087] When a polyurethane adhesive is used in the adhesive layer, any suitable polyurethane adhesive can be used. As such a polyurethane adhesive, preferably, a polyurethane adhesive comprising an adhesive polymer obtained by reacting a polyol with a polyisocyanate compound, i.e., a polyurethane polymer, can be cited. As polyols, for example, polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, etc. can be cited. As polyisocyanate compounds, for example, diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, etc. can be cited.

[0088] When a polysiloxane adhesive is used in the adhesive layer, any suitable polysiloxane adhesive may be used. As such a polysiloxane adhesive, a polysiloxane adhesive obtained by blending or aggregating a polysiloxane polymer as an adhesive polymer may be preferably used.

[0089] In addition, examples of the polysiloxane adhesive include addition reaction curing type polysiloxane adhesives and peroxide curing type polysiloxane adhesives. Among these polysiloxane adhesives, addition reaction curing type polysiloxane adhesives are preferred because they do not use peroxides (such as benzoyl peroxide) and do not produce decomposition products.

[0090] As a curing reaction of the addition reaction curing type polysiloxane adhesive, for example, in the case of obtaining a polyalkylpolysiloxane adhesive, a method of curing a polyalkylhydrogensiloxane composition using a platinum catalyst is generally exemplified.

[0091] <Fluorinated oligomers>

[0092] The adhesive composition of the present invention is characterized in that it contains an adhesive polymer, a fluorinated oligomer with a weight-average molecular weight of 3500 or more, and an ionic compound. By including a fluorinated oligomer with a weight-average molecular weight of 3500 or more in the adhesive composition, when the resulting adhesive layer (adhesive sheet) is attached to an optical component such as a polarizing plate, the low surface free energy of the fluorinated moieties in the fluorinated oligomer can provide an easy peeling effect. In addition, the fluorinated oligomer acts as a tackifying resin, improving adhesion and suppressing slippage (drift), lifting, peeling, etc. of the surface protective film. In other words, it is possible to achieve both easy peelability (repeelability) and adhesiveness, which is a preferred embodiment. In addition, for the adhesive sheet of the present invention, it is preferred that: an adhesive layer formed from the adhesive composition according to any one of claims 1 to 3 is provided on at least one side of the substrate film, and the fluorinated oligomer is present inside and / or on the surface of the adhesive layer. It should be noted that "inside" the adhesive layer means, for example, when the adhesive layer is formed using the adhesive composition incorporating the fluorinated oligomer, that the adhesive layer is contained in the adhesive layer. In addition, the "surface" of the above-mentioned adhesive layer refers to, for example, a case where the fluorinated oligomer contained in the adhesive layer formulated with the above-mentioned fluorinated oligomer is present (exposed) on the surface of the adhesive layer, or a case where the above-mentioned fluorinated oligomer is pre-coated (laminated) on the surface of a spacer pasted to protect the surface of the above-mentioned adhesive layer and the above-mentioned spacer is pasted to the above-mentioned adhesive layer, and the above-mentioned fluorinated oligomer is transferred (transferred) from the surface of the above-mentioned spacer to the surface of the above-mentioned adhesive layer.

[0093] The weight average molecular weight (Mw) of above-mentioned fluorine-containing type oligomer is more than 3500, preferably more than 5000, more preferably more than 10000, further preferably more than 20000.When the weight average molecular weight of above-mentioned fluorine-containing type oligomer is more than 3500, further play the function as tackifying resin, adhesiveness improves, and can suppress the sliding (deviation), warping, peeling etc. of surface protection film.Further, when the weight average molecular weight is more than 20000, can suppress the foaming when adhesive (composition) cooperates, the appearance after adhesive coating is excellent, therefore preferably.In addition, as the upper limit of the weight average molecular weight (Mw) of above-mentioned fluorine-containing type oligomer, preferably less than 200,000, more preferably less than 100,000.By being less than 200,000, fluorine-containing type oligomer is easily segregated on the surface, more easily plays light peeling effect, therefore preferably.

[0094] Specific examples of the fluorinated oligomers include commercially available products under the trade names of Megafac F-251, F-253, F-281, F-410, F-430, F-444, F-477, F-510, F-511, F-551, F-552, F-553, F-554, F-555, F-556, F-557, F-558, F-559, F-560, F-561, F-562, F-563, F-565, F-568, F-569, F-570, F-571, and F-572 (all manufactured by DIC Corporation), Surflon S-611, S-651, and S-386 (all manufactured by AGCSEI EMICHEMICAL), and Ftergent 610FM, 710FL, 710FM, 710FS, 730FL, 730LM (all manufactured by NEOS), etc. These compounds may be used alone or in combination of two or more.

[0095] The content of the above-mentioned fluorine-containing oligomer is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of the adhesive polymer (which is a base polymer, such as a (meth) acrylic polymer, a polyurethane polymer, a polysiloxane polymer, etc.) constituting the above-mentioned adhesive composition, more preferably 0.02 to 7.5 parts by mass, further preferably 0.03 to 5.5 parts by mass, and most preferably 0.04 to 4.8 parts by mass. When it is within the above-mentioned range, after the adhesive sheet of the present invention is attached to an optical component, etc., it can suppress sliding (offset), warping, peeling, etc., and it is excellent in light peelability, so it is preferred. In addition, in order to meet the contamination resistance, the content of the above-mentioned fluorine-containing oligomer is preferably 0.01 to 5.5 parts by mass relative to 100 parts by mass of the above-mentioned adhesive polymer.

[0096] <Ionic compounds>

[0097] The adhesive composition contains an ionic compound, and as the ionic compound, at least one of an alkali metal salt, an ionic liquid, and a polysiloxane containing an ionic group is preferably used. By containing at least one of these ionic compounds, excellent antistatic properties and peeling electrical properties can be imparted.

[0098] As for the above-mentioned alkali metal salt, since ion dissociation is high, it is preferable from the viewpoint that even a small amount of addition can show excellent antistatic ability. As the above-mentioned alkali metal salt, for example, a compound containing Li + 、Na + , K + cations and Cl - Br - , I- 、AlCl4 - 、Al2Cl7 - 、BF4 - 、PF6 - 、SCN - 、ClO4 - 、NO3 - 、CH3COO - 、C9H 19 COO - 、CF3COO - 、C3F7COO - 、CH3SO3 - 、CF3SO3 - 、C4F9SO3 - 、C2H5OSO3 - 、C6H 13 OSO3 - 、C8H 17 OSO3 - 、(CF3SO2)2N - 、(C2F5SO2)2N - 、(C3F7SO2)2N - 、(C4F9SO2)2N - 、(CF3SO2)3C - 、AsF6 - 、SbF6 - 、NbF6 - 、TaF6 - 、F(HF) n - 、(CN)2N - 、(CF3SO2)(CF3CO)N - 、(CH3)2PO4 - 、(C2H5)2PO4 - 、CH3(OC2H4)2OSO3 - 、C6H(CH3)SO3 - 、(C2F5)3PF3 - 、CH3CH(OH)COO - and (FSO2)2N -More preferably, lithium salts such as LiBr, LiI, LiBF4, LiPF6, LiSCN, LiClO4, LiCF3SO3, Li(CF3SO2)2N, Li(C2F5SO2)2N, Li(FSO2)2N, and Li(CF3SO2)3C are used, and even more preferably, LiCF3SO3, Li(CF3SO2)2N, Li(C2F5SO2)2N, Li(C3F7SO2)2N, Li(C4F9SO2)2N, Li(FSO2)2N, and Li(CF3SO2)3C are used. These alkali metal salts may be used alone or in combination of two or more.

[0099] Among the above-mentioned ionic liquids, those containing organic cation components and anion components represented by the following formulas (A) to (E) are preferably used. Among these ionic liquids containing cations, by using an ionic liquid having a melting point of 100°C or less, an ionic liquid with better antistatic properties can be obtained.

[0100]

[0101] R in the above formula (A) a represents a hydrocarbon group having 4 to 20 carbon atoms, or a functional group in which a portion of the hydrocarbon group is substituted with a heteroatom, R b and R c The same or different, represents hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and may be a functional group in which a portion of the above hydrocarbon group is substituted by a heteroatom. However, when the nitrogen atom contains a double bond, there is no R c .

[0102] R in the above formula (B) d represents a hydrocarbon group having 2 to 20 carbon atoms, or a functional group in which a portion of the hydrocarbon group is substituted with a heteroatom, R e 、R f and R g The same or different functional groups may represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and may be functional groups in which a portion of the hydrocarbon group is substituted with a heteroatom.

[0103] R in the above formula (C) h represents a hydrocarbon group having 2 to 20 carbon atoms, or a functional group in which a portion of the hydrocarbon group is substituted with a heteroatom, R i 、R j and R k The same or different functional groups may represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, and may be functional groups in which a portion of the hydrocarbon group is substituted with a heteroatom.

[0104] In the above formula (D), Z represents a nitrogen, sulfur or phosphorus atom, and R l 、Rm 、R n and R o The same or different, represents a hydrocarbon group having 1 to 20 carbon atoms, and may also be a functional group in which a portion of the above hydrocarbon group is substituted by a heteroatom. However, when Z is a sulfur atom, there is no R o .

[0105] R in the above formula (E) P The hydrocarbon group having 1 to 18 carbon atoms may be a functional group in which a part of the hydrocarbon group is substituted with a heteroatom.

[0106] Examples of the cation represented by formula (A) include pyridinium Cation, piperidine Cation, pyrrolidine Cation, cation with pyrroline skeleton, cation with pyrrole skeleton, morpholine Cations, etc.

[0107] As a specific example, 1-ethylpyridine can be mentioned. Cation, 1-butylpyridine Cation, 1-hexylpyridine Cation, 1-butyl-3-methylpyridine Cation, 1-butyl-4-methylpyridine Cation, 1-hexyl-3-methylpyridine Cation, 1-butyl-3,4-dimethylpyridine Cation, 1,1-dimethylpyrrolidine Cation, 1-ethyl-1-methylpyrrolidine Cation, 1-methyl-1-propylpyrrolidine Cation, 1-methyl-1-butylpyrrolidine Cation, 1-methyl-1-pentylpyrrolidine Cation, 1-methyl-1-hexylpyrrolidine Cation, 1-methyl-1-heptylpyrrolidine Cation, 1-ethyl-1-propylpyrrolidine Cation, 1-ethyl-1-butylpyrrolidine Cation, 1-ethyl-1-pentylpyrrolidine Cation, 1-ethyl-1-hexylpyrrolidine Cation, 1-ethyl-1-heptylpyrrolidine Cation, 1,1-dipropylpyrrolidine Cation, 1-propyl-1-butylpyrrolidine Cation, 1,1-dibutylpyrrolidine Cation, pyrrolidine -2-Ketocation, 1-propylpiperidine Cation, 1-pentylpiperidine Cation, 1,1-dimethylpiperidine Cation, 1-methyl-1-ethylpiperidine Cation, 1-methyl-1-propylpiperidine Cation, 1-methyl-1-butylpiperidine Cation, 1-methyl-1-pentylpiperidine Cation, 1-methyl-1-hexylpiperidine Cation, 1-methyl-1-heptylpiperidine Cation, 1-ethyl-1-propylpiperidinium Cation, 1-ethyl-1-butylpiperidinium Cation, 1-ethyl-1-pentylpiperidine Cation, 1-ethyl-1-hexylpiperidine Cation, 1-ethyl-1-heptylpiperidine Cation, 1,1-dipropylpiperidine Cation, 1-propyl-1-butylpiperidine Cation, 1,1-dibutylpiperidine cation, 2-methyl-1-pyrrolinium cation, 1-ethyl-2-phenylindole cation, 1,2-dimethylindole cation, 1-ethylcarbazole cation, N-ethyl-N-methylmorpholine Cations, etc.

[0108] Examples of the cation represented by formula (B) include imidazoles Cations, tetrahydropyrimidines Cations, dihydropyrimidines Cations, etc.

[0109] As a specific example, 1,3-dimethylimidazole can be mentioned. Cation, 1,3-diethylimidazole Cation, 1-ethyl-3-methylimidazole Cation, 1-butyl-3-methylimidazole Cation, 1-hexyl-3-methylimidazole Cation, 1-octyl-3-methylimidazole Cation, 1-decyl-3-methylimidazole Cation, 1-dodecyl-3-methylimidazole Cation, 1-tetradecyl-3-methylimidazole Cation, 1,2-dimethyl-3-propylimidazole Cation, 1-ethyl-2,3-dimethylimidazole Cation, 1-butyl-2,3-dimethylimidazole Cation, 1-hexyl-2,3-dimethylimidazole Cation, 1-(2-methoxyethyl)-3-methylimidazole Cation, 1,3-dimethyl-1,4,5,6-tetrahydropyrimidine Cation, 1,2,3-trimethyl-1,4,5,6-tetrahydropyrimidine Cation, 1,2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidine Cation, 1,2,3,5-tetramethyl-1,4,5,6-tetrahydropyrimidine Cation, 1,3-dimethyl-1,4-dihydropyrimidine Cation, 1,3-dimethyl-1,6-dihydropyrimidine Cation, 1,2,3-trimethyl-1,4-dihydropyrimidine Cation, 1,2,3-trimethyl-1,6-dihydropyrimidine Cation, 1,2,3,4-tetramethyl-1,4-dihydropyrimidine Cation, 1,2,3,4-tetramethyl-1,6-dihydropyrimidine Cations, etc.

[0110] Examples of the cation represented by formula (C) include pyrazoles and Cation, dihydropyrazole Cations, etc.

[0111] As a specific example, 1-methylpyrazole can be mentioned. Cation, 3-methylpyrazole Cation, 1-ethyl-2-methylpyrazole Cation, 1-ethyl-2,3,5-trimethylpyrazole Cation, 1-propyl-2,3,5-trimethylpyrazole Cation, 1-butyl-2,3,5-trimethylpyrazole Cation, 1-ethyl-2,3,5-trimethyldihydropyrazole Cation, 1-propyl-2,3,5-trimethyldihydropyrazole Cation, 1-butyl-2,3,5-trimethylpyrazole Cations, etc.

[0112] Examples of the cation represented by formula (D) include tetraalkylammonium cations, trialkylsulfonium cations, tetraalkyl Cations, cations in which a part of the above-mentioned alkyl groups is replaced with alkenyl groups, alkoxy groups or epoxy groups, and the like.

[0113] Specific examples include 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, trihexylammonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylammonium cation, tetramethyl Cation, tetraethyl Cationic, tetrabutyl Cation, tetrahexyl Cationic, tetraoctyl Cation, triethylmethyl Cation, tributyl ethyl Cation, trimethyldecyl cation, diallyldimethylammonium cation, tributyl-(2-methoxyethyl) Among them, triethylmethylammonium cation, tributylethylammonium cation, trimethyldecylammonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation, triethylmethyl Cation, tributyl ethyl Cation, trimethyldecyl Cations such as asymmetric tetraalkylammonium cations, trialkylsulfonium cations, tetraalkyl cation or N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium cation, N,N-dimethyl-N-ethyl-N-propylammonium 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-dimethyl-N-butyl-N-hexylammonium cation, N,N-diethyl-N-butyl-N-heptyl ammonium cation, N,N-dimethyl-N-pentyl-N-hexyl ammonium cation, N,N-dimethyl-N,N-dihexyl ammonium cation, trimethylheptyl ammonium cation, N,N-diethyl-N-methyl-N-propyl ammonium cation, N,N-diethyl-N-methyl-N-pentyl ammonium cation, N,N-diethyl-N-methyl-N-heptyl ammonium cation, N,N-diethyl-N-propyl-N-pentyl ammonium cation, triethylpropyl ammonium cation, triethylpentyl ammonium cation, triethylheptyl ammonium 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.

[0114] Examples of the cation represented by formula (E) include sulfonium cations. P Specific examples of include methyl, ethyl, propyl, butyl, hexyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, and octadecyl.

[0115] On the other hand, as for the anion component, there is no particular limitation as long as it satisfies the requirement of forming an ionic liquid, and for example, Cl - Br - , I - 、AlCl4 - 、Al2Cl7 - 、BF4 - PF6 -、SCN - 、ClO4 - 、NO3 - 、CH3COO - CF3COO - 、CH3SO3 - CF3SO3 - 、C4F9SO3 - 、(CF3SO2)2N - 、(C2F5SO2)2N - 、(C3F7SO2)2N - 、(C4F9SO2)2N - 、(CF3SO2)3C - 、AsF6 - 、SbF6 - 、NbF6 - 、TaF6 - 、F(HF) n - 、(CN)2N - 、C4F9SO3 - 、(C2F5SO2)2N - 、C3F7COO - 、(CF3SO2)(CF3CO)N - 、C9H 19 COO - 、(CH3)2PO4 - 、(C2H5)2PO4 - 、CH3OSO3 - 、C2H5OSO3 - 、C4H9OSO3 - 、C6H 13 OSO3 - 、C8H 17 OSO3 - 、CH3(OC2H4)2OSO3 - 、C6H4(CH3)SO3 - 、(C2F5)3PF3 - 、CH3CH(OH)COO - 、(FSO2)2N - 、B(CN)4 - 、C(CN)3 - 、N(CN)2 - , p-toluenesulfonate anion, 2-(2-methoxyethyl)ethyl sulfate anion, etc.

[0116] These ionic liquids may be used alone or in combination of two or more.

[0117] Furthermore, as the above-mentioned ionic group-containing polysiloxane, a polysiloxane represented by the following formula (1) is preferred.

[0118]

[0119] It should be noted that R1 to R4 in the above formula (1) may be the same or different and include any of an alkyl group having 1 to 10 carbon atoms, an alkoxy group, an aryl group, an alicyclic group, a fluorinated alkyl group, and an ionic group, and at least one of R1 to R4 includes an ionic group. n is an integer from 0 to 100.

[0120] Furthermore, as the ionic group contained in one or more of R1 to R4, an ammonium cation group or Ionic groups of cationic groups. Among them, one or more of R1 to R4 preferably contain a cationic structure and an anionic component represented by the following formula (a) or (b), or preferably a zwitterionic structure represented by (c) or (d).

[0121]

[0122] In the above formula (a), R5 to R7 may be the same or different and represent any of an alkyl group, an aryl group, and a fluorine-substituted alkyl group having 1 to 10 carbon atoms. m is an integer of 1 to 10.

[0123]

[0124] In the above formula (b), R8 to R 10 They may be the same or different and represent any one of an alkyl group, an aryl group, and a fluorine-substituted alkyl group having 1 to 10 carbon atoms. m is an integer of 1 to 10.

[0125] On the other hand, as the anion component, there is no particular limitation, and for example, Cl - Br - , I - 、AlCl4 - 、Al2Cl7 - 、BF4 - PF6 - 、ClO4 - 、NO3 - 、CH3COO - CF3COO - 、CH3SO3 - CF3SO3 - 、C4F9SO3 - 、(CF3SO2)2N - 、(C2F5SO2)2N -、(C3F7SO2)2N - 、(C4F9SO2)2N - 、(CF3SO2)3C - 、AsF6 - 、SbF6 - 、NbF6 - 、TaF6 - 、F(HF) n - 、(CN)2N - 、C4F9SO3 - 、(C2F5SO2)2N - 、C3F7COO - 、(CF3SO2)(CF3CO)N - 、C9H 19 COO - 、(CH3)2PO4 - 、(C2H5)2PO4 - 、C2H5OSO3 - 、C6H 13 OSO3 - 、C8H 17 OSO3 - 、CH3(OC2H4)2OSO3 - 、C6H4(CH3)SO3 - 、(C2F5)3PF3 - 、CH3CH(OH)COO - and (FSO2)2N - wait.

[0126]

[0127] R in the above formula (c) 11 、R 12 may be the same or different, and represent any one of an alkyl group, an aryl group, or a fluorine-substituted alkyl group having 1 to 10 carbon atoms, and R 11 、R 12 It may form a ring, in which case it represents an alkylene group. m is an integer of 1 to 10, and p is an integer of 1 to 6.

[0128]

[0129] R in the above formula (d) 13 、R 14 may be the same or different, and represent any one of an alkyl group, an aryl group, or a fluorine-substituted alkyl group having 1 to 10 carbon atoms, and R 13 、R 14It may form a ring, in which case it represents an alkylene group. m is an integer of 1 to 10, and p is an integer of 1 to 6.

[0130] For such polysiloxanes containing ionic groups, since they contain polysiloxane chains, due to the low surface free energy of the polysiloxane chains, even when the adhesive layer is adhered to the surface of an adherend (such as a polarizing plate) and stored in a high-temperature environment, the polysiloxane containing ionic groups will not penetrate into the adherend (from the surface of the adherend to the interior of the adherend) but will remain on the surface of the adhesive layer. Therefore, the peeling charge characteristics are stable over time, the antistatic performance can be maintained for a long time, and it can be suitably used as an antistatic agent.

[0131] Specific examples of the ionic group-containing polysiloxane include commercially available products under the trade names X-40-2450 and X-40-2750 (both manufactured by Shin-Etsu Chemical Co., Ltd.) These compounds may be used alone or in combination of two or more.

[0132] The content of the ionic compound is preferably 0.01 to 10 parts by mass, more preferably 0.02 to 7.5 parts by mass, further preferably 0.03 to 5.5 parts by mass, and most preferably 0.04 to 4.8 parts by mass, relative to 100 parts by mass of the adhesive polymer (base polymer, such as a methacrylic polymer, a polyurethane polymer, or a polysiloxane polymer) constituting the adhesive composition. When the content falls within the above range, it is easier for the adhesive sheet of the present invention to achieve both antistatic properties and slip (drift) suppression, and therefore is preferred.

[0133] <Oxyalkylene-containing compounds>

[0134] The adhesive composition of the present invention preferably contains an oxyalkylene-containing compound, more preferably an organopolysiloxane having an oxyalkylene chain, and even more preferably an organopolysiloxane having an oxyalkylene backbone. It is speculated that the use of such an organopolysiloxane reduces the surface free energy of the adhesive surface, thereby facilitating release.

[0135] As the organopolysiloxane, a known organopolysiloxane having a polyoxyalkylene main chain can be suitably used, and an organopolysiloxane represented by the following formula (2) is preferred.

[0136]

[0137] It should be noted that in the above formula (2), R1 and / or R2 have an oxyalkylene chain having 1 to 6 carbon atoms. The alkylene group in the oxyalkylene chain may be linear or branched, and the terminal of the oxyalkylene chain may be an alkoxy group or a hydroxyl group. In addition, either R1 or R2 may be a hydroxyl group, an alkyl group, an alkoxy group, or a functional group in which a portion of the above alkyl group or alkoxy group is substituted with a heteroatom. n is an integer from 1 to 300.

[0138] The organopolysiloxane used herein has a siloxane-containing moiety (siloxane moiety) as its main chain, with an oxyalkylene chain bonded to the terminal end of the main chain. It is speculated that the use of such an organosiloxane having an oxyalkylene chain achieves a balanced compatibility with (meth)acrylic polymers, fluorinated oligomers, and ionic compounds, thereby achieving easy peelability.

[0139] Furthermore, the organopolysiloxane described herein may have a structure such as the one shown below. Specifically, R1 and / or R2 in the formula have an oxyalkylene chain containing a hydrocarbon group having 1 to 6 carbon atoms. Examples of such oxyalkylene chains include oxymethylene, oxyethylene, oxypropylene, and oxybutylene, with oxyethylene and oxypropylene being preferred. It should be noted that when both R1 and R2 have oxyalkylene chains, they may be the same or different.

[0140] Furthermore, the hydrocarbon group of the oxyalkylene chain may be a linear chain or a branched chain.

[0141] Furthermore, the terminal of the oxyalkylene chain may be an alkoxy group or a hydroxyl group, with an alkoxy group being more preferred. When a spacer is attached to the surface of the adhesive layer for the purpose of protecting the adhesive surface, the organopolysiloxane having a hydroxyl group at the terminal may interact with the spacer, and the adhesive (peel) strength may increase when the spacer is peeled from the adhesive layer surface.

[0142] Furthermore, n is an integer of 1 to 300, preferably 10 to 200, and more preferably 20 to 150. When n is within this range, a balance of compatibility with the base polymer is achieved, which is a preferred embodiment. Furthermore, the molecule may contain reactive substituents such as (meth)acryloyl, allyl, or hydroxyl groups. These organopolysiloxanes may be used alone or as a mixture of two or more.

[0143] Specific examples of the organopolysiloxane having an oxyalkylene chain in the main chain include commercially available products under the trade names X-22-4952, X-22-4272, X-22-6266, KF-6004, and KF-889 (all manufactured by Shin-Etsu Chemical Co., Ltd.), BY16-201, SF8427 (all manufactured by Toray-Dow Corning Co., Ltd.), and IM22 (manufactured by Asahi Kasei Wacker Co., Ltd.). These compounds may be used alone or in combination of two or more.

[0144] In addition to the organosiloxanes having (bonded to) an oxyalkylene chain in the main chain, organosiloxanes having (bonded to) an oxyalkylene chain in the side chain may also be used. The use of organosiloxanes having (bonded to) an oxyalkylene chain in the side chain is a more preferred embodiment than organosiloxanes having an oxyalkylene chain in the main chain. The organopolysiloxanes described above may be suitably known organopolysiloxanes having polyoxyalkylene side chains, preferably an organopolysiloxane represented by the following formula (3).

[0145]

[0146] In the above formula (2), R1 is a monovalent organic group, R2, R3, and R4 are alkylene groups, R5 is hydrogen or an organic group, and m and n are integers from 0 to 1000. However, m and n cannot be 0 at the same time. a and b are integers from 0 to 100. However, a and b cannot be 0 at the same time.

[0147] In addition, as the above-mentioned organopolysiloxane in the present invention, for example, the following composition can be used. Specifically, R1 in the formula is a monovalent organic group exemplified by an alkyl group such as methyl, ethyl, or propyl, an aryl group such as phenyl, tolyl, or an aralkyl group such as benzyl or phenethyl, each of which may have a substituent such as a hydroxyl group. R2, R3, and R4 may be an alkylene group having 1 to 8 carbon atoms such as a methylene group, an ethylene group, or a propylene group. Here, R3 and R4 are different alkylene groups, and R2 may be the same as or different from R3 or R4. R5 may be a monovalent organic group exemplified by an alkyl group such as methyl, ethyl, or propyl, or an acyl group such as an acetyl group or a propionyl group, each of which may have a substituent such as a hydroxyl group. These compounds may be used alone or in combination of two or more. In addition, the molecule may have a reactive substituent such as a (meth)acryloyl group, an allyl group, or a hydroxyl group. Among the above-mentioned organosiloxanes having a polyoxyalkylene side chain, organosiloxanes having a polyoxyalkylene side chain with a hydroxyl terminal are considered to be preferable because they can easily achieve a good balance in compatibility.

[0148] Specific examples of the organosiloxane having an oxyalkylene chain in the side chain include commercially available products under the trade names KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6022, X-22-6191, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017, X-22-2516 (all manufactured by Shin-Etsu Chemical Co., Ltd.), SF842 8. FZ-2162, SH3749, FZ-77, L-7001, FZ-2104, FZ-2110, L-7002, FZ-2122, FZ-2164, FZ-2203, FZ-7001, SH8400, SH8700, SF8410, SF8422 (all manufactured by Toray-Dow Corning), TSF-4440, TSF-4441, TSF-4445, TSF-4450, TSF-4446, TSF-4452, TSF-4460 (Momentive Advanced Materials BYK-UV3500, BYK-UV3570 (manufactured by BYK-CHEMIE JAPAN), etc. These compounds may be used alone or in combination of two or more.

[0149] The organosiloxane used in the present invention preferably has an HLB (Hydrophile-Lipophile Balance) value of 1 to 16, more preferably 3 to 14. An HLB value outside the above range is not preferred because the staining property to the adherend deteriorates.

[0150] The adhesive composition may contain an oxyalkylene group-containing compound other than organopolysiloxane. By containing the compound in the adhesive, an adhesive having better wettability to an adherend can be obtained.

[0151] Specific examples of the above-mentioned oxyalkylene-containing compounds that do not include organopolysiloxanes include: nonionic surfactants such as polyoxyalkylene alkylamines, polyoxyalkylene diamines, polyoxyalkylene fatty acid esters, polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene alkyl ethers, polyoxyalkylene alkyl allyl ethers, and polyoxyalkylene alkylphenyl allyl ethers; anionic surfactants such as polyoxyalkylene alkyl ether sulfates, polyoxyalkylene alkyl ether phosphates, polyoxyalkylene alkylphenyl ether sulfates, and polyoxyalkylene alkylphenyl ether phosphates; and cationic surfactants or amphoteric surfactants having a polyoxyalkylene chain (polyalkylene oxide chain), polyether compounds having a polyoxyalkylene chain (and derivatives thereof), and acrylic compounds having a polyoxyalkylene chain (and derivatives thereof). In addition, a polyoxyalkylene chain-containing monomer can be added as the polyoxyalkylene chain-containing compound. The polyoxyalkylene chain-containing compound can be used alone or in combination of two or more.

[0152] Specific examples of the polyether compounds (polyether components) having a polyoxyalkylene chain include block copolymers of polypropylene glycol (PPG) and polyethylene glycol (PEG), block copolymers of PPG-PEG-PPG, and block copolymers of PEG-PPG-PEG. Derivatives of the polyether compounds having a polyoxyalkylene chain include terminally etherified compounds containing oxypropylene groups (such as PPG monoalkyl ether and PEG-PPG monoalkyl ether) and terminally acetylated compounds containing oxypropylene groups (such as terminally acetylated PPG).

[0153] Specific examples of acrylic compounds having polyoxyalkylene chains include (meth)acrylate polymers having oxyalkylene groups. The number of added moles of the oxyalkylene units is preferably 1 to 50, more preferably 2 to 30, and even more preferably 2 to 20. The termini of the oxyalkylene chains may be hydroxyl groups alone or substituted with alkyl groups, phenyl groups, or the like.

[0154] The (meth)acrylate polymer having an oxyalkylene group is preferably a polymer containing a (meth)acrylate alkylene oxide as a monomer unit (component). Specific examples of the (meth)acrylate alkylene oxide include methoxypolyethylene glycol (meth)acrylate type such as methoxydiethylene glycol (meth)acrylate and methoxytriethylene glycol (meth)acrylate; ethoxydiethylene glycol (meth)acrylate and ethoxytriethylene glycol (meth)acrylate; and ethylene glycol (meth)acrylate type such as ethoxydiethylene glycol (meth)acrylate and ethoxytriethylene glycol (meth)acrylate. Oxyethylene glycol (meth)acrylate type; butoxy polyethylene glycol (meth)acrylate type such as butoxydiethylene glycol (meth)acrylate and butoxytriethylene glycol (meth)acrylate; phenoxy polyethylene glycol (meth)acrylate type such as phenoxydiethylene glycol (meth)acrylate and phenoxytriethylene glycol (meth)acrylate; 2-ethylhexyl polyethylene glycol (meth)acrylate and nonylphenol polyethylene glycol (meth)acrylate type; methoxy polypropylene glycol (meth)acrylate type such as methoxydipropylene glycol (meth)acrylate, etc.

[0155] In addition, as the above-mentioned monomer units (components), other monomer units (components) other than the above-mentioned (meth)acrylic acid alkylene oxides may also be used. Specific examples of other monomer components include acrylates and / or methacrylates having an alkyl group having 1 to 14 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, and n-tetradecyl (meth)acrylate.

[0156] Furthermore, as other monomer units (components) other than the above-mentioned (meth)acrylic acid alkylene oxides, carboxyl group-containing (meth)acrylates, phosphoric acid group-containing (meth)acrylates, cyano group-containing (meth)acrylates, vinyl esters, aromatic vinyl compounds, anhydride group-containing (meth)acrylates, hydroxyl group-containing (meth)acrylates, amide group-containing (meth)acrylates, amino group-containing (meth)acrylates, epoxy group-containing (meth)acrylates, N-acryloylmorpholine, vinyl ethers, and the like can also be suitably used.

[0157] As a more preferred embodiment, the compound containing a polyoxyalkylene chain that does not include an organopolysiloxane is a compound having a (poly)ethylene oxide chain in at least a portion. By combining the compound containing a (poly)ethylene oxide chain, the compatibility of the base polymer with a fluorine-containing oligomer or an ionic compound is improved, and the oozing out in the adherend is suitably suppressed to obtain a low-pollution adhesive composition. Among them, in particular, when a block copolymer of PPG-PEG-PPG is used, an adhesive with excellent low pollution is obtained. As the compound containing a polyoxyalkylene chain, the weight of the (poly)ethylene oxide chain in the overall compound containing a polyoxyalkylene chain that does not include an organopolysiloxane is preferably 5% by mass to 90% by mass, more preferably 5% by mass to 85% by mass, further preferably 5% by mass to 80% by mass, and most preferably 5% by mass to 75% by mass.

[0158] As for the molecular weight of the above-mentioned polyoxyalkylene chain-containing compound excluding organopolysiloxane, a compound having a number average molecular weight (Mn) of 50,000 or less is more suitable, preferably 200 to 30,000, and more preferably 200 to 10,000. Generally, a compound having a number average molecular weight of 200 to 5,000 is preferably used. When Mn is too large than 50,000, the compatibility with the acrylic polymer is reduced, and there is a tendency for the adhesive layer to whiten. When Mn is too small than 200, it is possible that contamination caused by the above-mentioned polyoxyalkylene compound becomes more likely to occur. It should be noted that, herein, Mn refers to the value converted to polystyrene obtained by GPC (gel permeation chromatography).

[0159] Specific examples of commercially available products of the above-mentioned polyoxyalkylene chain-containing compounds that do not include organopolysiloxane include: Adeka Pluronic 17R-4, Adeka Pluronic 25R-2 (all manufactured by ADEKA Corporation); Latemul PD-420, Latemul PD-420, Latemul PD-450, Emulgen 120 (manufactured by Kao Corporation); Aqualon HS-10, KH-10, Noigen EA-87, EA-137, EA-157, EA-167, EA-177 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), etc.

[0160] The content of the oxyalkylene group-containing compound is preferably 0.01 to 5.0 parts by mass, more preferably 0.02 to 2 parts by mass, further preferably 0.03 to 1.6 parts by mass, and most preferably 0.1 to 0.8 parts by mass, relative to 100 parts by mass of the adhesive polymer (a base polymer, such as a (meth)acrylic polymer, a polyurethane polymer, or a polysiloxane polymer) constituting the adhesive composition. A content within this range is preferred because it facilitates achieving both slippage (deflection) and easy peelability (repeelability) of the adhesive sheet of the present invention.

[0161] Cross-linking agent

[0162] In the adhesive sheet (surface protection film) of the present invention, the adhesive composition preferably contains a crosslinking agent. In addition, in the present invention, the adhesive composition can be used to form an adhesive layer. For example, when the adhesive composition is an acrylic adhesive containing the (meth) acrylic polymer, by appropriately adjusting the constituent units, constituent ratio, selection and addition ratio of the crosslinking agent of the (meth) acrylic polymer and performing crosslinking, an adhesive sheet (adhesive layer) with better heat resistance can be obtained.

[0163] As the cross-linking agent used in the present invention, isocyanate compounds, epoxy compounds, melamine resins, aziridine derivatives and metal chelate compounds can be used, and in particular, the use of isocyanate compounds is a preferred embodiment. In addition, these compounds can be used alone or in combination of two or more.

[0164] As the above-mentioned isocyanate compound, for example, aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), dimer acid diisocyanate, etc.; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate (IPDI), 1,3-bis(isocyanatomethyl)cyclohexane, etc.; aromatic isocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate (XDI), etc.; aromatic isocyanates such as allophanate bond, biuret bond, isocyanurate bond, uretdione bond, urea bond, carbodiimide bond, uretonimide bond, The polyisocyanate modified body after the above-mentioned isocyanate compound is modified by diazinetrione bond etc. For example, the trade names Takenate 300S, Takenate 500, Takenate 600, Takenate D165N, Takenate D178N (above, Takeda Pharmaceutical Co., Ltd. manufactures), Sumidule T80, Sumidule L, Desmodur N3400 (above, Sumika Bayer Urethane Co., Ltd. manufactures), Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (above, Japan Polyurethane Industry Co., Ltd. manufactures) etc. as commercial products can be cited. These isocyanate compounds can be used alone or in combination of two or more, or a difunctional isocyanate compound and a trifunctional or higher isocyanate compound can be used in combination. By using a cross-linking agent in combination, it is possible to take into account both adhesiveness and resilience resistance (adhesion to curved surfaces), and it is possible to obtain an adhesive sheet with more excellent adhesion reliability.

[0165] In addition, when a bifunctional isocyanate compound and a trifunctional or higher isocyanate compound are used as the above-mentioned isocyanate compound, as the mixing ratio (mass ratio) of the two compounds, it is preferably mixed with [bifunctional isocyanate compound] / [trifunctional or higher isocyanate compound] (mass ratio) of 0.1 / 99.9 to 50 / 50, more preferably 0.1 / 99.9 to 20 / 80, further preferably 0.1 / 99.9 to 10 / 90, more preferably 0.1 / 99.9 to 5 / 95, and most preferably 0.1 / 99.9 to 1 / 99. By adjusting the mixing ratio within the above range, a pressure-sensitive adhesive layer having excellent adhesiveness and repulsion resistance is obtained, which is a preferred embodiment.

[0166] Examples of the epoxy compound include N,N,N',N'-tetraglycidyl-m-xylylenediamine (trade name TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (trade name TETRAD-C, manufactured by Mitsubishi Gas Chemical Co., Ltd.).

[0167] Examples of the melamine-based resin include hexamethylolmelamine, etc. Examples of the aziridine derivative include commercially available products under the trade names HDU, TAZM, and TAZO (all manufactured by Souhyo Pharmaceutical Co., Ltd.).

[0168] Examples of the metal chelate compound include aluminum, iron, tin, titanium, nickel, and the like as the metal component, and acetylene, methyl acetoacetate, ethyl lactate, and the like as the chelate component.

[0169] For the content of the cross-linking agent used in the present invention, for example, relative to 100 parts by mass of the above-mentioned (meth) acrylic polymer, it is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, further preferably 0.5 to 10 parts by mass, and most preferably 1 to 6 parts by mass. When the above-mentioned content is less than 0.01 parts by mass, the cross-linking formation using the cross-linking agent becomes insufficient, and there is a tendency that the cohesive force of the obtained adhesive layer becomes smaller, and sometimes sufficient heat resistance cannot be obtained, and it becomes the cause of the adhesive residue. On the other hand, when the content exceeds 20 parts by mass, the cohesive force of the polymer is large, and the fluidity is reduced, and there is a tendency that the wetting of the adherend (such as polarizing plate) is insufficient, and it becomes the cause of the bulge between the adherend and the adhesive layer (adhesive composition layer). In addition, these cross-linking agents can be used alone or in combination of two or more.

[0170] The pressure-sensitive adhesive composition may further contain a cross-linking catalyst for more efficiently carrying out the optional cross-linking reaction. Examples of the crosslinking catalyst include tin catalysts such as dibutyltin dilaurate and dioctyltin dilaurate; tris(acetylacetonate)iron (acetylacetonate iron (III)), tris(hexane-2,4-dione)iron, tris(heptane-2,4-dione)iron, tris(heptane-3,5-dione)iron, tris(5-methylhexane-2,4-dione)iron, tris(octane-2,4-dione)iron, tris(6-methylheptane-2,4-dione)iron, tris(2,6-dimethylheptane-3,5-dione)iron, tris(nonane-2,4-dione)iron, tris(nonane-4,6-dione)iron, tris(2,2,6,6-tetramethylheptane-3,5-dione)iron, tris(tridecane-6,8-dione)iron, and tris(tridecane-6,8-dione). Iron catalysts such as tris(1-phenylbutane-1,3-dionato)iron, tris(hexafluoroacetylacetonato)iron, tris(ethyl acetoacetate)iron, tris(n-propyl acetoacetate)iron, tris(isopropyl acetoacetate)iron, tris(n-butyl acetoacetate)iron, tris(sec-butyl acetoacetate)iron, tris(tert-butyl acetoacetate)iron, tris(methyl propionylacetate)iron, tris(ethyl propionylacetate)iron, tris(n-propyl propionylacetate)iron, tris(isopropyl propionylacetate)iron, tris(n-butyl propionylacetate)iron, tris(sec-butyl propionylacetate)iron, tris(tert-butyl propionylacetate)iron, tris(benzyl acetoacetate)iron, tris(dimethyl malonate)iron, tris(diethyl malonate)iron, trimethoxyferric, triethoxyferric, triisopropoxyferric, and ferric chloride may be used. These crosslinking catalysts may be used alone or in combination of two or more.

[0171] The content of the crosslinking catalyst is not particularly limited. For example, it is preferably about 0.0001 to 1 part by mass, and more preferably 0.001 to 0.5 parts by mass, relative to 100 parts by mass of the (meth)acrylic polymer. Within this range, the crosslinking reaction rate during formation of the adhesive layer is accelerated, and the pot life of the adhesive composition is also prolonged, which is a preferred embodiment.

[0172] In addition, the above-mentioned adhesive composition may contain a compound that produces keto-enol tautomerism. For example, in an adhesive composition containing a cross-linking agent or an adhesive composition that can be used in conjunction with a cross-linking agent, it is preferred to use a method containing the above-mentioned compound that produces keto-enol tautomerism. Thus, it is possible to suppress excessive viscosity increase and gelation of the adhesive composition after the cross-linking agent is used, thereby achieving the effect of extending the pot life of the adhesive composition. When at least an isocyanate compound is used as the above-mentioned cross-linking agent, it is particularly meaningful to contain a compound that produces keto-enol tautomerism. For example, this technology can be preferably applied when the above-mentioned adhesive composition is in the form of an organic solvent solution or a solvent-free form.

[0173] As the compounds that produce keto-enol tautomerism, various β-dicarbonyl compounds can be used. Specific examples include: β-diketones such as acetylacetone, 2,4-hexanedione, 3,5-heptanedione, 2-methylhexane-3,5-dione, 6-methylheptane-2,4-dione, and 2,6-dimethylheptane-3,5-dione; acetoacetic acid esters such as methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, and tert-butyl acetoacetate; propionylacetic acid esters such as ethyl propionylacetate, ethyl propionylacetate, isopropyl propionylacetate, and tert-butyl propionylacetate; isobutyrylacetic acid esters such as ethyl isobutyrylacetate, ethyl isobutyrylacetate, isopropyl isobutyrylacetate, and tert-butyl isobutyrylacetate; and malonic acid esters such as methyl malonate and ethyl malonate. Preferred compounds include acetylacetone and acetoacetic acid esters. The compounds that produce keto-enol tautomerism can be used alone or in combination of two or more.

[0174] The content of the compound that produces keto-enol tautomerism can be set to, for example, 0.1 to 20 parts by mass, and is typically appropriately set to 0.5 to 15 parts by mass (e.g., 1 to 10 parts by mass), relative to 100 parts by mass of the (meth)acrylic polymer. If the amount of the compound is too small, it may be difficult to achieve a sufficient effect. On the other hand, if the compound is used in an excessively large amount, it may remain in the adhesive layer, reducing cohesive strength.

[0175] In addition, the above-mentioned adhesive composition may contain other well-known additives, for example, lubricants, colorants, pigment powders, plasticizers, tackifiers, low molecular weight polymers, surface lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, ultraviolet absorbers, polymerization inhibitors, silane coupling agents, inorganic or organic fillers, metal powders, particles, foils, etc. may be appropriately added according to the intended use.

[0176] <Adhesive layer and adhesive sheet (surface protective film)>

[0177] The adhesive sheet of the present invention is an adhesive sheet obtained by forming the above-mentioned adhesive layer on at least one side of a substrate film. In this case, crosslinking of the adhesive composition is usually performed after coating the adhesive composition, but the adhesive layer containing the crosslinked adhesive composition can also be transferred to a substrate film, etc.

[0178] In addition, the method for forming an adhesive layer on a substrate film is not particularly limited, and for example, it can be prepared in the following manner: the above-mentioned adhesive composition (solution) is applied to a substrate film, and the polymerization solvent is dried and removed, thereby forming an adhesive layer on the substrate film. Afterwards, it is also possible to perform maintenance for the purpose of adjusting the composition transfer of the adhesive layer or adjusting the cross-linking reaction. In addition, when the adhesive composition is applied to a substrate film to make an adhesive sheet, one or more solvents other than the polymerization solvent can be newly added to the above-mentioned adhesive composition so that it can be evenly coated on the substrate film.

[0179] In addition, as a method for forming the adhesive layer when manufacturing the adhesive sheet of the present invention, a known method used in the manufacture of adhesive tapes can be used. Specifically, for example, roll coating, gravure coating, reverse coating, roller brushing, spray coating, air knife coating, extrusion coating using a die coater, etc. can be mentioned.

[0180] The adhesive sheet of the present invention is generally prepared so that the thickness of the adhesive layer is about 3 μm to about 100 μm, preferably about 5 μm to about 50 μm. When the thickness of the adhesive layer is within this range, it is easier to achieve an appropriate balance between removability and adhesiveness, which is preferred.

[0181] The adhesive sheet of the present invention preferably has a total thickness of 8 μm to 300 μm, more preferably 10 μm to 200 μm, and most preferably 20 μm to 100 μm. Within this range, adhesive properties (removability, tackiness, etc.), workability, and appearance are excellent, making this a preferred embodiment. It should be noted that the total thickness described above refers to the total thickness of all layers, including the base film, adhesive layer, and other layers.

[0182] <Spacer>

[0183] In the adhesive sheet of the present invention, a separator is preferably attached to the surface of the adhesive layer opposite to the surface in contact with the substrate film. The separator may be attached to the surface of the adhesive layer as needed for the purpose of protecting the adhesive surface.

[0184] The separator may be made of paper or plastic film, but plastic film is preferred due to its excellent surface smoothness. The film is not particularly limited as long as it can protect the adhesive layer. Examples thereof include polyethylene film, polypropylene film, polybutylene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene-vinyl acetate copolymer film.

[0185] The separator typically has a thickness of about 5 μm to about 200 μm, preferably about 10 μm to about 100 μm. This range is preferred because it provides excellent adhesion and peeling properties to and from the adhesive layer. The separator may also be subjected to mold release and antifouling treatments, such as those using silicone, fluorine-containing, long-chain alkyl, or fatty acid amide release agents, or silica powder, as needed, or antistatic treatments such as coating, kneading, or vapor deposition.

[0186] In the adhesive sheet of the present invention, it is preferred that the fluorinated oligomer (see Figure 1 ). By having the fluorinated oligomer on the surface of the separator in contact with the adhesive layer, when the separator is attached to the adhesive layer, the fluorinated oligomer is transferred from the surface of the separator to the surface of the adhesive layer. After the adhesive layer is attached to an adherend (e.g., a polarizing plate), etc., an easy peeling effect due to the low surface free energy of the fluorinated portion can be achieved, and the fluorinated oligomer acts as a tackifying resin to improve the adhesiveness, thereby suppressing the sliding (deviation), warping, and peeling of the surface protective film (taking into account both re-peelability and adhesiveness), which is a more preferred embodiment.

[0187] <Optical components>

[0188] The optical component of the present invention is preferably attached (protected) by the adhesive sheet described above, or, if the separator is attached, preferably by the adhesive sheet with the separator removed. Due to its excellent curl control and easy peelability, the adhesive sheet can be used for surface protection (surface protection film) during processing, transportation, and shipment, making it a useful adhesive sheet for protecting the surface of the optical component (polarizing plate, etc.).

[0189] Example

[0190] Hereinafter, several embodiments related to the present invention will be described, but it is not intended that the present invention be limited to the scope shown in the specific examples. It should be noted that the "parts" and "%" in the following description are based on mass unless otherwise specified. In addition, the blending amount (addition amount) in the table is shown.

[0191] In addition, each characteristic in the following description was measured or evaluated by the following method.

[0192] <Measurement of weight average molecular weight (Mw)>

[0193] The weight average molecular weight (Mw) of the polymers and the like used was measured using a GPC apparatus (HLC-8220GPC) manufactured by Tosoh Corporation. The measurement conditions are as follows.

[0194] Sample concentration: 0.2 mass% (tetrahydrofuran (THF) solution)

[0195] Injection volume: 10 μl

[0196] Eluent: THF

[0197] Flow rate: 0.6 ml / min

[0198] Measurement temperature: 40°C

[0199] Chromatographic column:

[0200] Sample column: TSKguardcolumn SuperHZ-H (1 column) + TSKgel SuperHZM-H (2 columns)

[0201] Reference column: TSKgel SuperH-RC (1 column)

[0202] Detector: Differential Refractometer (RI)

[0203] The weight average molecular weight was calculated as a polystyrene equivalent value. The number average molecular weight (Mn) was also measured in the same manner as the weight average molecular weight (Mw).

[0204] <Foaming of Adhesive Composition (Solution)>

[0205] The adhesive compositions (solutions) of each example were mixed and stirred, and then the adhesive compositions (solutions) were visually observed for bubbling. The evaluation was performed by marking "○" if no bubbling was observed, "△" if slight bubbling was observed, and "×" if obvious bubbling was observed.

[0206] <Shear force>

[0207] The surface protective film was cut into a size of 10 mm in width and 100 mm in length, and the separator was peeled off. Then, the adhesive layer of the adhesive sheet was cut into a size of 1 cm 2 The film was bonded to a TAC polarizing plate (SEG1423DU polarizing plate manufactured by Nitto Denko Corporation, width: 25 mm, length: 100 mm) and stretched at 23°C at a stretching speed of 0.06 mm / min in the shear direction. The maximum load (N / cm 2 ) as shear force.

[0208] The surface protection film of the present invention preferably has a shear force of 5 N / cm2 at 23°C x 50% RH on the polarizing plate of the adhesive layer used in the surface protection film. 2 More than 5N / cm 2 ~50N / cm 2 , more preferably 7N / cm 2 ~40N / cm 2 By adjusting the shear force to 5N / cm 2 The above-mentioned method can suppress slipping (deviating), lifting, peeling, etc. after being attached to an adherend, and has excellent curl control properties, which is a preferred embodiment.

[0209] <Measurement of peeling charge voltage>

[0210] The adhesive sheet 1 of each example was cut into a size of 70 mm in width and 130 mm in length, the release liner (separator) was peeled off, and then a manual roller was used to press-bond the adhesive sheet 1 to the surface of the polarizing plate 20 (manufactured by Nitto Denko Corporation, SEG1423DU polarizing plate, width: 70 mm, length: 100 mm) attached to the glass plate 10 in such a manner that one end of the adhesive sheet 1 protruded 30 mm from the end of the polarizing plate 20.

[0211] The sample was placed in an environment of 23°C × 50% RH for 1 day and then Figure 2 As shown, the sample fixing table 30 with a height of 20 mm is set at a predetermined position. The end of the adhesive sheet (surface protection film) 1 protruding 30 mm from the polarizing plate 20 is fixed to an automatic winder (not shown) so that the peeling angle is 150 ° The peeling was performed at a peeling speed of 30 m / min. The potential on the surface of the adherend (polarizing plate 20) generated at this time was measured using a potential meter 40 (manufactured by Shishido Electrostatics Co., Ltd., model "Statiron DZ-4") fixed at a height of 30 mm from the center of the polarizing plate 20 to determine the "peeling charge voltage." The measurement was performed in an environment of 23°C and 50% RH.

[0212] It should be noted that the stripping charge voltage (kV) (absolute value) in the present invention is preferably 1.0 or less, more preferably 0.5 or less, and even more preferably 0.3 or less. When within the above range, antistatic properties and stripping electrical properties are excellent, and workability is excellent, which is a preferred embodiment.

[0213] <Presence of contamination (pollution resistance)>

[0214] Evaluation samples were prepared by cutting the adhesive sheet from each example into a size of 50 mm wide and 80 mm long. The separator was peeled off and then pressed onto a TAC polarizing plate (SEG1423DU polarizing plate manufactured by Nitto Denko Corporation, width: 70 mm, length: 100 mm) using a hand roller while allowing air bubbles to enter. These evaluation samples were left at 70°C for 120 hours, then the adhesive sheet was manually peeled from the adherend, and the surface of the adherend was visually observed for any air bubble traces. The evaluation was performed with a value of "○" if no air bubble traces were observed, and a value of "×" if air bubble traces were observed.

[0215] <Measurement of low-speed peel force>

[0216] The surface protective film cut into 25 mm in width and 100 mm in length after being placed in an environment of 23°C and 50% RH for 24 hours was laminated to a TAC polarizing plate (manufactured by Nitto Denko Corporation, SEG1423DU polarizing plate, width: 70 mm, length: 100 mm) under a pressure of 0.25 MPa and a speed of 0.3 m / min to produce an evaluation sample. After lamination, the film was placed in an environment of 23°C and 50% RH for 30 minutes, and then the peeling speed was measured using a universal tensile tester at a peeling speed of 0.3 m / min (slow peeling) and a peeling angle of 180°. ° Low-speed peel force (N / 25 mm) during peeling. The measurement was performed under an environment of 23°C and 50% RH.

[0217] In the surface protection film of the present invention, it is preferred that the adhesive layer used in the surface protection film has a high thermal conductivity and a low heat release rate. ° The peel strength (tensile speed 0.3 m / min: low-speed peel strength) is 0.15 N / 25 mm or less, more preferably 0.01 N / 25 mm to 0.15 N / 25 mm, and even more preferably 0.02 N / 25 mm to 0.14 N / 25 mm. By adjusting the peel strength (tensile speed 0.3 m / min) to 0.15 N / 25 mm or less, peeling becomes easier (repeelability) when a surface protective film is not required, and damage to the adherend can also be prevented, which is a preferred embodiment.

[0218] <Preparation of acrylic polymer (1)>

[0219] In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser, 96 parts by mass of 2-ethylhexyl acrylate (2EHA), 4 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.2 parts by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 150 parts by mass of ethyl acetate were placed. While slowly stirring, nitrogen was introduced, and the liquid temperature in the flask was maintained at approximately 65°C. A polymerization reaction was carried out for 6 hours to prepare an acrylic polymer (1) solution (40% by mass). The weight average molecular weight (Mw) of the acrylic polymer (1) was 540,000.

[0220] <Preparation of acrylic polymer (2)>

[0221] In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser, 91 parts by mass of 2-ethylhexyl acrylate (2EHA), 9 parts by mass of 4-hydroxybutyl acrylate (4HBA), 0.02 parts by mass of acrylic acid (AA), 0.2 parts by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 150 parts by mass of ethyl acetate were placed. While slowly stirring, nitrogen was introduced, and the liquid temperature in the flask was maintained at approximately 65°C. A polymerization reaction was carried out for 6 hours to prepare an acrylic polymer (2) solution (40% by mass). The weight average molecular weight (Mw) of the acrylic polymer (2) was 540,000.

[0222] <Preparation of acrylic polymer (3)>

[0223] In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser, 98.5 parts by mass of 2-ethylhexyl acrylate (2EHA), 1.5 parts by mass of 4-hydroxybutyl acrylate (4HBA), 0.2 parts by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 150 parts by mass of ethyl acetate were placed. While slowly stirring, nitrogen was introduced, and the liquid temperature in the flask was maintained at approximately 65°C. A polymerization reaction was carried out for 6 hours to prepare an acrylic polymer (3) solution (40% by mass). The weight average molecular weight (Mw) of the acrylic polymer (3) was 550,000.

[0224] <Example 1>

[0225] [Preparation of acrylic adhesive solution]

[0226] The acrylic polymer (1) solution (40% by mass) was diluted to 20% by mass with ethyl acetate. To 500 parts by mass of this solution (100 parts by mass of solid content), 0.5 parts by mass of a solution of a fluorinated oligomer (Megafac F-562, manufactured by DIC Corporation) diluted to 10% with ethyl acetate (0.05 parts by mass of solid content), 5 parts by mass of a solution of LiTFSI as an ionic compound diluted to 10% with ethyl acetate (0.5 parts by mass of solid content), 3 parts by mass of the isocyanurate form of hexamethylene diisocyanate (Coronate HX, manufactured by Tosoh Corporation) as a trifunctional isocyanate compound as a crosslinking agent (3 parts by mass of solid content), and 3 parts by mass of dibutyltin dilaurate (1% by mass ethyl acetate solution) as a crosslinking catalyst (0.03 parts by mass of solid content) were added and mixed and stirred to prepare an acrylic adhesive solution.

[0227] [Production of antistatic treatment film]

[0228] An antistatic agent solution was prepared by diluting 10 parts by mass of an antistatic agent (MICROSOLVER RMd-142 manufactured by SOLVEX, mainly composed of tin oxide and polyester resin) with a mixed solvent containing 30 parts by mass of water and 70 parts by mass of methanol.

[0229] The obtained antistatic agent solution was applied onto a polyethylene terephthalate (PET) film (thickness: 38 μm) using a Mayer bar, and the solvent was removed by drying at 130° C. for 1 minute to form an antistatic layer (thickness: 0.2 μm), thereby producing an antistatic treated film.

[0230] [Production of Adhesive Sheet (Surface Protective Film)]

[0231] The acrylic adhesive solution was applied to the surface of the antistatic film opposite the antistatic treatment surface and heated at 130°C for 2 minutes to form a 15 μm thick adhesive layer. Next, the silicone-treated surface of a polyethylene terephthalate film (25 μm thick) with silicone treatment applied to one side was laminated to the adhesive layer to produce a PSA sheet.

[0232] <Examples 2 to 12>

[0233] According to the raw materials and compounding amounts described in Table 1, a pressure-sensitive adhesive sheet was produced by the same method as in Example 1.

[0234] <Example 13>

[0235] [Preparation of polyurethane adhesive solution]

[0236] 85 parts by mass of PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000) as a polyol having three hydroxyl groups, 13 parts by mass of SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000) as a polyol having three hydroxyl groups, 2 parts by mass of SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000) as a polyol having three hydroxyl groups, 18 parts by mass of an isocyanate compound (Coronate HX: C / HX, manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.04 parts by mass of iron (III) acetylacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst, 0.2 parts by mass of fluorinated oligomer Megafac F-562 (manufactured by DIC Corporation) and 1-ethyl-3-methylimidazole as an ionic compound were prepared. A polyurethane adhesive solution was prepared by mixing 1 part by mass of tris(fluoromethanesulfonyl)imide salt (EMITFSI, manufactured by Tokyo Chemical Industry Co., Ltd.) and 210 parts by mass of ethyl acetate as a diluent. Subsequently, a PSA sheet was prepared by adjusting the heating conditions and the thickness of the resulting PSA layer in the same manner as in Example 1.

[0237] <Example 14>

[0238] [Preparation of polysiloxane adhesive solution]

[0239] 100 parts by mass of "X-40-3229" (solid content 60%, manufactured by Shin-Etsu Chemical Co., Ltd.) as a polysiloxane adhesive, 0.5 parts by mass of "CAT-PL-50T" (manufactured by Shin-Etsu Chemical Co., Ltd.) as a platinum catalyst, 0.2 parts by mass of fluorinated oligomer Megafac F-562 (manufactured by DIC Corporation), 1-ethyl-3-methylimidazole as an ionic compound, A polysiloxane adhesive solution was prepared by mixing 1 part by mass of tris(fluoromethanesulfonyl)imide salt (EMITFSI, manufactured by Tokyo Chemical Industry Co., Ltd.) and 100 parts by mass of toluene as a solvent. Subsequently, an adhesive sheet was prepared by adjusting the heating conditions and the thickness of the resulting adhesive layer in the same manner as in Example 1.

[0240] Comparative Examples 1 to 3

[0241] According to the raw materials and compounding amounts described in Table 1, a pressure-sensitive adhesive sheet was produced by the same method as in Example 1.

[0242] The above-mentioned formulations, various measurements, and evaluation results of the PSA sheets of Examples and Comparative Examples are shown in Tables 1 and 2. The formulation amounts in Table 1 represent the active ingredients. The abbreviations in Table 1 are explained below.

[0243] [Fluorinated oligomers]

[0244] F-562: Fluorinated oligomer, weight-average molecular weight 27,900, manufactured by DIC Corporation, trade name: Megafac F-562

[0245] F-558: Fluorinated oligomer, weight-average molecular weight 11,900, manufactured by DIC Corporation, trade name: Megafac F-558

[0246] F-569: Fluorinated oligomer, weight-average molecular weight 6920, manufactured by DIC Corporation, trade name: Megafac F-569

[0247] 222F: Fluorinated oligomer, weight-average molecular weight 2940, manufactured by NEOS, trade name: Fergent 222F

[0248] [Oxyalkylene-containing compounds]

[0249] PD-420: An oxyalkylene-containing compound excluding organopolysiloxane (HLB value: 12.6), manufactured by Kao Corporation, trade name: Latemul PD-420

[0250] KF-353: Organopolysiloxane containing an oxyalkylene chain, manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-353

[0251] [Ionic compounds]

[0252] LiTFSI: Lithium bis(trifluoromethanesulfonyl)imide, manufactured by Tokyo Chemical Industry Co., Ltd.

[0253] Bu3MePTFSI: tributylmethyl Bis(trifluoromethanesulfonyl)imide salt, manufactured by Tokyo Chemical Industry Co., Ltd.

[0254] X-40-2450: Polysiloxane containing ionic groups, manufactured by Shin-Etsu Chemical Co., Ltd.

[0255] BMPTFSI: 1-Butyl-3-methylpyridine Bis(trifluoromethanesulfonyl)imide salt, manufactured by Wako Pure Chemical Industries, Ltd.

[0256] MTOATFSI: Methyltrioctylammonium bis(trifluoromethanesulfonyl)imide, manufactured by Tokyo Chemical Industry Co., Ltd.

[0257] EMITFSI: 1-ethyl-3-methylimidazole Tris(fluoromethanesulfonyl)imide salt, manufactured by Tokyo Chemical Industry Co., Ltd.

[0258]

[0259]

[0260] Table 2 confirms that all examples exhibited excellent shear force and peel charge voltage. Furthermore, when the fluorinated oligomer was adjusted to a content of 5.5 parts by mass or less per 100 parts by mass of the polymer used, which exhibits excellent stain resistance, excellent stain resistance (low staining properties) was also observed. Furthermore, in examples using fluorinated oligomers with a weight-average molecular weight of 20,000 or greater, it was confirmed that foaming of the adhesive composition (solution) was suppressed.

[0261] On the other hand, Table 2 confirms that in Comparative Example 1, the peeling charge voltage was poor due to the lack of an ionic compound, and in Comparative Example 2, the shear force was poor due to the lack of a fluorinated oligomer. Furthermore, in Comparative Example 3, the shear force was poor due to the use of a fluorinated oligomer with a weight-average molecular weight of less than 3,500. Furthermore, in Comparative Example 3, the use of the fluorinated oligomer 222F with a weight-average molecular weight of less than 20,000 resulted in foaming of the adhesive composition (solution).

[0262] Industrial Applicability

[0263] The pressure-sensitive adhesive sheet disclosed herein is suitable as a surface protective film for protecting optical components used as components of liquid crystal display panels, plasma display panels (PDPs), organic electroluminescent (EL) displays, etc., during manufacture and transportation of the optical components. In particular, it is useful as a surface protective film (optical surface protective film) for optical components such as polarizing plates (polarizing films), wave plates, retardation plates, optical compensation films, brightness enhancement films, light diffusers, and reflective sheets used in liquid crystal display panels.

Claims

1. An adhesive composition, characterized in that The adhesive composition contains an adhesive polymer, a fluorine-containing oligomer having a weight-average molecular weight of 3500 or more, and an ionic compound.

2. The adhesive composition according to claim 1, wherein It contains an oxyalkylene group-containing compound.

3. The adhesive composition according to claim 1 or 2, wherein The adhesive polymer is at least one selected from the group consisting of (meth)acrylic polymers, polyurethane polymers, and polysiloxane polymers.

4. An adhesive sheet, characterized in that The substrate film has an adhesive layer formed from the adhesive composition according to any one of claims 1 to 3 on at least one side thereof, and The fluorine-containing oligomer exists inside and / or on the surface of the adhesive layer.

5. The adhesive sheet according to claim 4, wherein A separator is attached to the surface of the pressure-sensitive adhesive layer opposite to the surface in contact with the base film.

6. The adhesive sheet according to claim 5, wherein The fluorinated oligomer is present on the surface of the separator that is in contact with the adhesive layer.

7. An optical component, characterized in that: The adhesive sheet is affixed with the adhesive sheet according to claim 4 or the adhesive sheet according to claim 5 or claim 6 from which the separator is peeled.

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