KR102290158B1 - Adhesive sheet and optical member - Google Patents

Abstract

A pressure-sensitive adhesive sheet capable of preventing the rise in adhesive strength over time at high temperature (adhesive strength increase prevention property, adhesive strength stability), suppressing low adhesive strength during high-speed peeling, excellent re-peelability and workability, and excellent shear strength. . The pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition on one or both sides of a support film, and the peeling rate after adhering the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer to the TAC surface at 23° C. for 30 minutes is 30 m The adhesive force ratio (B/A) of the adhesive force (A) at /min, and the adhesive force (B) at a peeling rate of 30 m/min after adhering the adhesive surface of the pressure-sensitive adhesive layer to the TAC surface at 70° C. for 1 week is less than 2 characterized in that

Description

An adhesive sheet and an optical member {ADHESIVE SHEET AND OPTICAL MEMBER}

The present invention relates to an adhesive sheet and an optical member protected by the adhesive sheet.

The pressure-sensitive adhesive sheet of the present invention is useful as a surface protection film used for the purpose of protecting the surface of an optical member such as a polarizing plate, a wave plate, a retardation plate, an optical compensation film, a reflective sheet, and a brightness improving film used in a liquid crystal display or the like.

In recent years, at the time of transportation of an optical component and an electronic component, or the case of mounting on a printed circuit board, conveying is performed in the state which packaged the individual component with the predetermined|prescribed sheet|seat, or the state which adhere|attached the adhesive tape. Among them, the surface protection film is particularly widely used in the field of optical and electronic components.

The surface protection film is generally bonded to an adherend (to-be-protected) via an adhesive applied to the support film side, and is used for the purpose of preventing damage and contamination occurring during processing and conveying of the adherend (Patent Document 1). ). For example, the panel of a liquid crystal display is formed by bonding optical members, such as a polarizing plate and a wave plate, to a liquid crystal cell via an adhesive. As for these optical members, a surface protection film is bonded through an adhesive, and the damage and contamination which arise at the time of processing and conveyance of a to-be-adhered body are prevented.

In addition, when processing a to-be-adhered body in the state in which the surface protection film was bonded, high temperature treatment may be performed, but in this case, the adhesive force of an adhesive layer may rise greatly, and after that, this surface protection film is unnecessary. When peeling and removing at a disintegrating stage, damage to a polarizing plate or liquid crystal cell as an adherend is likely to occur in the peeling process due to enlargement or thinning of a liquid crystal display panel as an adherend, etc. that is being demanded

In the surface protection film, when adhered to an adherend (polarizing plate, etc.), in the adherend to which the surface protection film is adhered (polarizing plate, etc.) Curl adjustment is required to prevent occurrence of a phenomenon in which a thing is entirely turned to one side or a phenomenon in which a flat plate is turned like a wave as a whole). When unnecessary curls or unintentional curls occur, handling properties are poor, for example, when an adherend such as a polarizing plate is adhered to a liquid crystal cell, problems such as generation of bubbles may occur.

In addition, when curling occurs in a flat-type adherend, a force accompanying the curl in the shearing direction acts on the pressure-sensitive adhesive layer of the surface protection film bonded to the adherend, and by this force, between the adherend and the pressure-sensitive adhesive layer, gradually slip or Since distortion etc. arise, the improvement of the shearing force at the time of low-speed peeling is calculated|required.

Japanese Patent Laid-Open No. 9-165460

Accordingly, an object of the present invention is to prevent an increase in adhesive strength over a high temperature over time (adhesive strength increase prevention property, adhesive strength stability) so as to solve the problems in the conventional adhesive sheet, and a low adhesive strength during high-speed peeling It is suppressed, and it is excellent in re-peelability and workability|operativity, and is providing the adhesive sheet excellent in shearing force.

That is, the pressure-sensitive adhesive sheet of the present invention, in the pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition on one or both sides of a support film, the pressure-sensitive adhesive side of the pressure-sensitive adhesive layer to the TAC surface at 23 ° C. The adhesive force (A) at 30 m/min, and the adhesive force ratio (B/A) of the adhesive force (B) at a peeling rate of 30 m/min after bonding the adhesive surface of the pressure-sensitive adhesive layer to the TAC surface at 70° C. for 1 week It is characterized in that it is less than 2.

As for the adhesive sheet of this invention, it is preferable that the said adhesive composition contains the (meth)acrylic-type polymer which has a hydroxyl group and a carboxyl group.

As for the adhesive sheet of this invention, it is preferable that the said adhesive composition contains a crosslinking agent, and it is preferable that the said crosslinking agent contains an aromatic isocyanate type compound and an aliphatic isocyanate type compound.

It is preferable that the adhesive sheet of this invention contains 5.1 mass % or more of a hydroxyl-group containing (meth)acrylic-type monomer with respect to the monomer component whole quantity which comprises the said (meth)acrylic-type polymer.

It is preferable that the adhesive sheet of this invention contains 0.01 mass % or more and less than 0.5 mass % of a carboxyl group-containing (meth)acrylic-type monomer with respect to the monomer component whole quantity which comprises the said (meth)acrylic-type polymer.

The pressure-sensitive adhesive sheet of the present invention has an antistatic layer on one side of the support film opposite to the pressure-sensitive adhesive layer, and the antistatic layer comprises polyanilinesulfonic acid as a conductive polymer component, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent. It is preferable to form from the antistatic agent composition containing.

As for the adhesive sheet of this invention, it is preferable that the said antistatic agent composition further contains fatty acid amide as a lubricating agent.

It is preferable that the optical member of this invention was protected by the said adhesive sheet.

The pressure-sensitive adhesive sheet of the present invention can prevent an increase in adhesive strength over time at high temperature (adhesive strength increase prevention property, adhesive strength stability), and low adhesive strength during high-speed peeling, excellent re-peelability and workability, and Since it is excellent in shearing force, when it joins to a to-be-adhered body, in to-be-adhered body, unnecessary curl and unintentional curl can be suppressed, and it is useful.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

<The overall structure of the adhesive sheet (surface protection film)>

The pressure-sensitive adhesive sheet (surface protection film) of the present invention is of a type generally referred to as an pressure-sensitive adhesive sheet, an adhesive tape, an adhesive label, an adhesive film, and the like, and in particular, an optical component (eg, a polarizing plate, a wave plate, etc., constitutes a liquid crystal display panel) It is suitable as a surface protection film which protects the surface of an optical component at the time of processing or conveyance of the optical component used as an element). The pressure-sensitive adhesive layer in the pressure-sensitive adhesive sheet is typically formed continuously, but is not limited to such a form, and may be a pressure-sensitive adhesive layer formed in a regular or random pattern such as dots or stripes, for example. In addition, a roll type may be sufficient as the adhesive sheet disclosed here, and a sheet-fed type may be sufficient as it.

Typical structural examples of the pressure-sensitive adhesive sheet (surface protection film) disclosed herein include those having a pressure-sensitive adhesive layer on one or both sides of the support film (substrate), an antistatic layer formed on one side of the support film, and an antistatic layer of the support film, What is provided with the adhesive layer formed in the surface of the opposite side is mentioned. The pressure-sensitive adhesive sheet is used by bonding this pressure-sensitive adhesive layer to an adherend (to be protected, for example, the surface of an optical component such as a polarizing plate). The pressure-sensitive adhesive sheet before use (i.e., before adhesion to the adherend) may be in a form in which the surface of the pressure-sensitive adhesive layer (adhesive surface to the adherend) is protected by a release liner at least on the pressure-sensitive adhesive layer side as the release surface. Alternatively, when the pressure-sensitive adhesive sheet is wound in roll shape, the pressure-sensitive adhesive layer may be in contact with the back surface (surface of the antistatic layer) of the support film, and the surface may be protected.

<Support film>

The pressure-sensitive adhesive sheet of the present invention is characterized in that it has a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition on one side or both sides of a support film. The resin material constituting the support film can be used without particular limitation, but it is preferable to use a resin material having excellent properties such as transparency, mechanical strength, thermal stability, moisture shielding property, isotropy, flexibility, and dimensional stability. In particular, when a support film has flexibility, an adhesive composition can be apply|coated by a roll coater etc., it can wind up in roll shape, and is useful.

Examples of the support film (substrate) include polyester-based polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate; Cellulose polymers, such as a diacetyl cellulose and a triacetyl cellulose; polycarbonate-based polymers; A plastic film composed of a resin material containing an acrylic polymer such as polymethyl methacrylate as a main resin component (a main component in the resin component, typically a component accounting for 50 mass% or more) can be preferably used as the support film. . Other examples of the resin material include styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymer; olefinic polymers such as polyethylene, polypropylene, polyolefin having a cyclic or norbornene structure, and an ethylene-propylene copolymer; vinyl chloride-based polymers; Examples of the resin material include those made of an amide-based polymer such as nylon 6, nylon 6,6 or aromatic polyamide. As another example of the resin material, an imide-based polymer, a sulfone-based polymer, a polyethersulfone-based polymer, a polyetheretherketone-based polymer, a polyphenylenesulfide-based polymer, a vinyl alcohol-based polymer, a vinylidene chloride-based polymer, a vinyl buty A ral-type polymer, an arylate-type polymer, a polyoxymethylene-type polymer, an epoxy-type polymer, etc. are mentioned. It may be a support film composed of a blend of two or more of the aforementioned polymers.

As said support film, the plastic film which consists of a transparent thermoplastic resin material is employable preferably. Among the said plastic films, it is a more preferable aspect to use a polyester film. Here, the polyester film is a polymer material (polyester resin) having a main skeleton based on an ester bond, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate as a main resin component. say to do While such a polyester film has characteristics suitable as a support film of an adhesive sheet, such as being excellent in an optical characteristic and dimensional stability, it has the property of being easy to charge as it is.

Various additives, such as antioxidant, a ultraviolet absorber, a plasticizer, and a coloring agent (pigment, dye, etc.), may be mix|blended with the resin material which comprises the said support film as needed. A known or customary surface treatment such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, application of a primer, etc. is applied to the first surface of the support film (the surface on which the antistatic layer is formed). It may be implemented. Such surface treatment may be, for example, a treatment for increasing the adhesion between the support film and the antistatic layer. A surface treatment in which a polar group such as a hydroxyl group (-OH group) is introduced into the surface of the support film can be preferably employed. Moreover, the surface treatment similar to the above may be given to the 2nd surface (surface at the side in which an adhesive layer is formed) of a support film. Such surface treatment may be a treatment for enhancing the adhesion between the film and the pressure-sensitive adhesive layer (the anchoring property of the pressure-sensitive adhesive layer).

Moreover, although it is also possible that the adhesive sheet of this invention has an antistatic layer on a support film, when it has an antistatic function, it is also possible to use the plastic film formed by antistatic treatment as the said support film. By using the said support film, since charging of the adhesive sheet itself at the time of peeling is suppressed, it is preferable. Moreover, the support film is a plastic film, and by giving the antistatic treatment to the said plastic film, the charging of the adhesive sheet itself can be reduced, and the thing excellent in the antistatic ability with respect to a to-be-adhered body can be obtained. In addition, there is no restriction|limiting in particular as a method of providing an antistatic function, A conventionally well-known method can be used, For example, the antistatic resin which consists of an antistatic agent and a resin component, a conductive polymer, or a conductive resin containing a conductive material is used. The method of coating, the method of vapor-depositing or plating a conductive substance, the method of kneading an antistatic agent, etc. are mentioned.

As thickness of the said support film, it is 5-200 micrometers normally, Preferably it is about 10-100 micrometers. When the thickness of the said support film exists in the said range, since it is excellent in the bonding workability|operativity with respect to a to-be-adhered body, and peeling workability from a to-be-adhered body, it is preferable.

<Adhesive composition>

The pressure-sensitive adhesive sheet (surface protection film) of the present invention has the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition. A urethane-based pressure-sensitive adhesive, a synthetic rubber-based pressure-sensitive adhesive, a natural rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, etc. may be used, and among them, more preferably at least one selected from the group consisting of an acrylic pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, and a silicone pressure-sensitive adhesive, particularly preferably ( Meth) an acrylic pressure-sensitive adhesive using an acryl-based polymer is used.

It is preferable that the said adhesive composition used by this invention contains the (meth)acrylic-type polymer which has a hydroxyl group and a carboxyl group. By using the (meth)acrylic polymer having the hydroxyl group and the carboxyl group, the hydroxyl group can easily control crosslinking, and the carboxyl group can improve shear force or prevent an increase in adhesive strength over time Since it can be done, it becomes a preferable aspect. In particular, since the shear force of the pressure-sensitive adhesive (layer) is improved, curling based on the adherend can be suppressed by bonding the pressure-sensitive adhesive to the adherend, and the occurrence of slip or distortion between the pressure-sensitive adhesive and the adherend (interface) is suppressed. It is preferable to be able to In addition, the (meth)acrylic-type polymer in this invention means an acryl-type polymer and/or a methacrylic-type polymer, and (meth)acrylate means an acrylate and/or a methacrylate.

In addition, when the (meth)acrylic polymer uses the hydroxyl group-containing (meth)acrylic monomer as a monomer component, it becomes easier to control crosslinking of the pressure-sensitive adhesive composition, etc. It becomes easy to control the balance with the reduction of the adhesive force at the time of the cohesive force of (layer) and peeling (light peelability), and a shear force. In addition, when an antistatic agent is added to the pressure-sensitive adhesive, unlike a carboxyl group or a sulfonate group that can generally act as a crosslinking site, the hydroxyl group has an appropriate interaction with an ionic compound that is an antistatic agent. It can be used suitably also also in cotton.

The pressure-sensitive adhesive sheet of the present invention preferably contains 5.1 mass% or more of a hydroxyl group-containing (meth)acrylic monomer with respect to the total amount of the monomer components constituting the (meth)acrylic polymer, more preferably 5.3 to 15 mass% %, more preferably 7 to 12 mass%. When it exists in the said range, since it becomes easy to control the balance of the wettability of an adhesive composition, and the cohesive force and shearing force of an adhesive (layer), it is preferable.

Examples of the hydroxyl group-containing (meth)acrylic 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-hydroxy Methylcyclohexyl)methyl acrylate, N-methylol (meth)acrylamide, etc. are mentioned.

The pressure-sensitive adhesive sheet of the present invention preferably contains 0.01 mass% or more and less than 0.5 mass% of a carboxyl group-containing (meth)acrylic monomer with respect to the total amount of monomer components constituting the (meth)acrylic polymer, more preferably 0.01 It is mass % or more and less than 0.4 mass %, More preferably, it is 0.01 mass % or more and less than 0.3 mass %, Most preferably, it is 0.01 mass % or more and less than 0.2 mass %. When it exists in the said range, an increase in adhesive force over time can be suppressed, and it is excellent in re-peelability, adhesive force increase prevention property, and workability. Moreover, it is excellent also in shearing force with the cohesive force of an adhesive layer, and it is preferable. In addition, when a large number of acid functional groups such as carboxyl groups having a large polar action exist, when an ionic compound is blended as an antistatic agent, the ionic compound interacts with an acid functional group such as a carboxyl group, and ion conduction is disturbed. , the conductive efficiency is lowered, and there is a fear that sufficient antistatic properties cannot be obtained, which is not preferable.

Examples of the carboxyl group-containing (meth)acrylic monomer include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloyloxyethylhexahydrophthalic acid , 2- (meth) acryloyloxypropyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl male Acid, carboxypolycaprolactone mono(meth)acrylate, 2-(meth)acryloyloxyethyl tetrahydrophthalic acid, etc. are mentioned.

The pressure-sensitive adhesive composition used in the present invention is not particularly limited as long as it contains the (meth)acrylic polymer and has adhesiveness, as long as it is a (meth)acrylic polymer having an alkyl group having 1 to 14 carbon atoms as a main component of the monomer component ( It is preferable to use a meth)acrylic-type monomer, More preferably, it is a (meth)acrylic-type monomer which has a C4-C14 alkyl group. As said (meth)acrylic-type monomer, 1 type(s) or 2 or more types can be used as a main component. In addition, a "main component" means the thing with the highest compounding ratio.

Specific examples of the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, iso Octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate , n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, and the like.

Especially, when using the adhesive sheet of this invention as a surface protection film, 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 which has a C6-C14 alkyl group, such as meth)acrylate and n-tetradecyl (meth)acrylate, is mentioned as a suitable thing. By using the (meth)acrylate which has a C6-C14 alkyl group, it becomes easy to control low adhesive force to a to-be-adhered body, and it becomes the thing excellent in re-peelability.

The pressure-sensitive adhesive sheet of the present invention preferably contains 50 to 94.99 mass% of the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms, with respect to the total amount of the monomer components constituting the (meth)acrylic polymer, more preferably Preferably it is 60-94.9 mass %, More preferably, it is 70-94.8 mass %, Most preferably, it is 80-94.7 mass %. By being in the said range, an adhesive composition has moderate wettability, and it is excellent also in the cohesive force of an adhesive (layer), and it is preferable.

In addition, as another polymerizable monomer component, for the reason that it is easy to balance the adhesive performance, the Tg is set to 0°C or less (usually -100°C or more), so that the glass transition temperature and peelability of the (meth)acrylic polymer are A polymerizable monomer for adjustment, etc. can be used in the range which does not impair the effect of this invention.

Other polymerizable properties other than the hydroxyl group-containing (meth)acrylic monomer used in the (meth)acrylic polymer, the carboxyl group-containing (meth)acrylic monomer, and the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms As a monomer, if it exists in the range which does not impair the characteristic of this invention, it can use without limitation in particular. For example, components for improving cohesion and heat resistance such as cyano group-containing monomers, vinyl ester monomers and aromatic vinyl monomers, amide group-containing monomers, imide group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, N-acryloylmorpholine , a component having a functional group acting as a starting point for improving adhesion (adhesion) or crosslinking, such as a vinyl ether monomer, can be appropriately used. These polymerizable monomers may be used independently, and 2 or more types may be mixed and used for them.

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

As said vinyl ester monomer, vinyl acetate, a vinyl propionate, vinyl laurate, etc. are mentioned, for example.

As said aromatic vinyl monomer, styrene, chlorostyrene, chloromethylstyrene, (alpha)-methylstyrene, other substituted styrene etc. are mentioned, for example.

Examples of the amide group-containing monomer include acrylamide, methacrylamide, diethylacrylamide, N-vinylpyrrolidone, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N, N-diethylacrylamide, N,N-diethylmethacrylamide, N,N'-methylenebisacrylamide, N,N-dimethylaminopropylacrylamide, N,N-dimethylaminopropylmethacrylamide, diacetone Acrylamide etc. are mentioned.

Examples of the imide group-containing monomer include cyclohexyl maleimide, isopropyl maleimide, N-cyclohexyl maleimide, and itaconimide.

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

As said epoxy group containing monomer, glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, allyl glycidyl ether, etc. are mentioned, for example.

As said vinyl ether monomer, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, etc. are mentioned, for example.

In the present invention, other polymerizable monomers other than the carboxyl group-containing (meth)acrylic monomer, the hydroxyl group-containing (meth)acrylic monomer, and the (meth)acrylic monomer having an alkyl group having 1 to 14 carbon atoms include ( It is preferable that it is 0-40 mass %, and it is more preferable that it is 0-30 mass % in the monomer component whole quantity (total monomer component) which comprises a meth)acrylic-type polymer. By using the said other polymerizable monomer within the said range, good interaction with the ionic compound which can be used as an antistatic agent, and good re-peelability can be adjusted suitably.

The said (meth)acrylic-type polymer has a weight average molecular weight of 100,000-5 million, Preferably it is 200,000-4 million, More preferably, it is 300,000-3 million. When a weight average molecular weight is smaller than 100,000, there exists a tendency for an adhesive residue to arise because the cohesive force of the adhesive (layer) obtained becomes small. On the other hand, when the weight average molecular weight exceeds 5 million, the fluidity of the polymer is lowered, and the wetting to the adherend (eg, a polarizing plate as an optical member, etc.) becomes insufficient, which occurs between the adherend and the pressure-sensitive adhesive composition layer of the adhesive sheet It tends to cause blisters. In addition, a weight average molecular weight means what was obtained by measuring by GPC (gel permeation chromatography).

In addition, the glass transition temperature (Tg) of the (meth)acrylic polymer is preferably 0°C or less, more preferably -10°C or less, and still more preferably -20°C or less (usually -100°C or more). When the glass transition temperature is higher than 0°C, the polymer is difficult to flow, for example, the wetting to the adherend (eg, a polarizing plate as an optical member, etc.) becomes insufficient, and blisters generated between the adherend and the pressure-sensitive adhesive composition layer of the pressure-sensitive adhesive sheet. tends to cause In particular, by setting the glass transition temperature to -61°C or lower, it becomes easy to obtain an adhesive composition excellent in wettability to an adherend and light peelability. Moreover, the glass transition temperature of a (meth)acrylic-type polymer can be adjusted within the said range by changing suitably the monomer component and composition ratio used.

The polymerization method of the (meth)acrylic polymer used in the present invention is not particularly limited, and polymerization can be performed by known methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. Solution polymerization is a more preferable aspect in terms of properties such as low contamination properties. In addition, any of a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer, etc. may be sufficient as the polymer obtained.

In the pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive composition may contain an antistatic agent (antistatic component), and may contain an ionic compound as the antistatic agent. Examples of the ionic compound include alkali metal salts and/or ionic compounds having a low melting point (melting point 150°C or lower). By containing these ionic compounds, the outstanding antistatic property can be provided.

Moreover, as for content of the said ionic compound with respect to 100 mass parts of said (meth)acrylic-type polymers, 1 mass part or less is preferable, 0.001-0.9 mass parts is more preferable, More preferably, it is 0.005-0.8 mass part. When it exists in the said range, since it is easy to make antistatic property and low contamination property compatible, it is preferable.

In the pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive composition may contain organopolysiloxane having a polyoxyalkylene chain. By using the said organopolysiloxane, the surface free energy of the surface of an adhesive falls and it is estimated that light-peel-ization at the time of high-speed peeling is implement|achieved.

As said organopolysiloxane, the organopolysiloxane which has a well-known polyoxyalkylene chain can be used suitably, For example, as a commercial item, brand name X-22-4952, X-22-4272, X-22-6266. , KF-6004, KF-889, 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 (above, manufactured by Shin-Etsu Chemical), BY16-201, SF8427 , SF8428, 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 (above, manufactured by Toray Dow Corning), IM22 (above, manufactured by Asahi Kasei Wacker), TSF-4440, TSF-4441, TSF-4445, TSF-4450, TSF-4446, TSF-4452, TSF- 4460 (above, the Momentive Performance Materials company make), BYK-333, BYK-307, BYK-377, BYK-UV3500, BYK-UV3570 (above, the Big Chemie Japan company make) etc. are mentioned. These may be used independently and may mix and use 2 or more types.

As said organopolysiloxane used by this invention, 1-16 are preferable as for HLB(Hydrophile-Lipophile Balance) value, More preferably, it is 3-14. When the HLB value is out of the above range, the contamination to the adherend deteriorates, which is undesirable.

In addition, the content of the organopolysiloxane is preferably 0.01 to 5 parts by mass, more preferably 0.03 to 3 parts by mass, and still more preferably 0.05 to 1 part by mass relative to 100 parts by mass of the (meth)acrylic polymer. . When it exists in the said range, since it is easy to make it compatible with antistatic property and light-peelability (re-peelability), it is preferable.

In the pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive composition preferably contains a crosslinking agent, and the crosslinking agent is an aromatic isocyanate-based compound and an aliphatic isocyanate-based compound (both isocyanate-based compounds are combined to be an isocyanate-based compound or an isocyanate-based crosslinking agent) ) is preferred. In addition, the crosslinking agent can be crosslinked by appropriately adjusting the selection and addition ratio of the crosslinking agent according to the structural unit or composition ratio of the (meth)acrylic polymer, thereby obtaining an adhesive sheet (adhesive layer) having more excellent heat resistance. . In particular, since the crosslinking agent contains an aromatic isocyanate-based compound and an aliphatic isocyanate-based compound, it is possible to prevent an increase in adhesive strength over time (adhesive strength increase prevention property) and is useful.

Further, as the crosslinking agent used in the present invention, in addition to the aromatic isocyanate compound and the aliphatic isocyanate compound, an epoxy compound, a melamine resin, an aziridine derivative, a metal chelate compound, and the like can be suitably used. In addition, these crosslinking agents may be used individually by 1 type, and may mix and use 2 or more types.

Examples of the aliphatic isocyanate-based compound include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), dimer acid diisocyanate, cyclopentylene diisocyanate, cyclohexylene diisocyanate, Alicyclic isocyanates, such as isophorone diisocyanate (IPDI), etc. are mentioned. Examples of the aromatic isocyanate compound include aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate (XDI). In addition, the isocyanate-based compound (isocyanate-based crosslinking agent) is combined with an allophanate bond, a biuret bond, an isocyanurate bond, a uretdione bond, a urea bond, a carbodiimide bond, a uretonimine bond, an oxadiazinetrione bond, etc. polyisocyanate-modified products modified by

For example, as a commercial item of the said isocyanate type compound (isocyanate type crosslinking agent), brand name Takenate 300S, Takenate 500, Takenate D110N, Takenate D140N, Takenate D165N, Takenate D178N (above, Mitsui Chemicals Co., Ltd. make), Sumi Joule T80, Sumijul L, Desmodule N3400 (above, manufactured by Sumika Bayer Urethane), Myrionate MR, Myrionate MT, Colonate L, Colonate HL, Colonate HX (above, manufactured by Nippon Polyurethane Co., Ltd.) and the like. These isocyanate compounds may be used in mixture of 2 or more types, and it is also possible to use them in combination with a bifunctional isocyanate compound and a trifunctional or more than trifunctional isocyanate compound. By using together and using a crosslinking agent, the rise of adhesive force with time can be prevented, or the adhesive sheet excellent in shearing force can be obtained.

Examples of the epoxy compound include N,N,N',N'-tetraglycidyl-m-xylenediamine (trade name: TETRAD-X, manufactured by Mitsubishi Gas Chemicals) and 1,3-bis(N,N) -diglycidylaminomethyl)cyclohexane (trade name: TETRAD-C, manufactured by Mitsubishi Gas Chemicals) etc. are mentioned.

Examples of the melamine-based resin include hexamethylolmelamine. As an aziridine derivative, the brand name HDU, TAZM, TAZO (above, the Sogoyak Corporation make) etc. as a commercial item are mentioned, for example.

As said metal chelate compound, aluminum, iron, tin, titanium, nickel, etc. as a metal component, acetylene, methyl acetoacetate, ethyl lactate, etc. are mentioned as a chelate component.

The content (total) of the crosslinking agent used in the present invention is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 8 parts by mass, with respect to 100 parts by mass of the (meth)acrylic polymer, It is more preferable to contain 0.5-5 mass parts, and it is most preferable to contain 1.0-4 mass parts. When the content is less than 0.01 parts by mass, crosslinking formation by the crosslinking agent becomes insufficient, the cohesive force of the pressure-sensitive adhesive composition becomes small, and sufficient heat resistance cannot be obtained in some cases, and also tends to cause pressure-sensitive adhesive residue. On the other hand, when the content exceeds 10 parts by mass, the cohesive force of the polymer is large, the fluidity is lowered, the wettability to the adherend (eg, a polarizing plate as an optical member, etc.) becomes insufficient, and the blister generated between the adherend and the pressure-sensitive adhesive composition layer. tends to be the cause. Moreover, when there is a large amount of crosslinking agent, there exists a tendency for peeling electrification characteristic to fall. In addition, these crosslinking agents may be used independently and may mix and use 2 or more types.

In addition, the mixing ratio of the aromatic isocyanate-based compound and the aliphatic isocyanate-based compound is not particularly limited, and for example, (aromatic isocyanate-based compound/aliphatic isocyanate-based compound) (mass ratio) is 3/1 to 1/50 This is preferable, 2/1 to 1/40 are more preferable, and 1/1 to 1/30 are still more preferable. If it is the said compounding ratio, it is useful because it can prevent the rise of adhesive force with time.

The pressure-sensitive adhesive composition may further contain a crosslinking catalyst in order to more effectively advance any of the crosslinking reactions described above. Examples of the crosslinking catalyst include tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate, tris(acetylacetonato)iron, tris(hexane-2,4-diionato)iron, and tris(heptane-2). ,4-diionato)iron, tris(heptane-3,5-diionato)iron, tris(5-methylhexane-2,4-diionato)iron, tris(octane-2,4-diionato)iron, Tris(6-methylheptane-2,4-diionato)iron, tris(2,6-dimethylheptane-3,5-diionato)iron, tris(nonane-2,4-diionato)iron, tris(nonane) -4,6-diionato)iron, tris(2,2,6,6-tetramethylheptane-3,5-diionato)iron, tris(tridecane-6,8-diionato)iron, tris(1) -Phenylbutane-1,3-diionato)iron, tris(hexafluoroacetylacetonato)iron, tris(ethyl acetoacetate)iron, tris(acetoacetate-n-propyl)iron, tris(acetoacetate isopropyl) )Iron, tris(acetoacetate-n-butyl)iron, tris(acetoacetate-sec-butyl)iron, tris(acetoacetate-tert-butyl)iron, tris(propionylmethylacetate)iron, tris(propionylacetic acid) ethyl)iron, tris(propionylacetate-n-propyl)iron, tris(propionylisopropylacetate)iron, tris(propionylacetate-n-butyl)iron, tris(propionylacetate-sec-butyl)iron, Tris(propionylacetate-tert-butyl)iron, tris(benzylacetate)iron, tris(dimethyl malonate)iron, tris(diethylmalonate)iron, trimethoxyiron, triethoxyiron, triisopropoxy An iron-based catalyst such as iron or ferric chloride can be used. One type may be sufficient as these crosslinking catalysts, and 2 or more types may be used together.

Although content (usage amount) in particular of the said crosslinking catalyst is not restrict|limited, For example, with respect to 100 mass parts of (meth)acrylic-type polymer, about 0.0001-1 mass part is preferable, and 0.001-0.5 mass part is more preferable. When it exists in the said range, when an adhesive layer is formed, the speed|rate of a crosslinking reaction is quick, and the pot life of an adhesive composition also becomes long, and it becomes a preferable aspect.

You may contain the polyoxyalkylene chain containing compound which does not contain an organopolysiloxane in the adhesive composition of this invention. By containing the said compound in an adhesive composition, the adhesive composition excellent in the wettability with respect to a to-be-adhered body can also be obtained.

Specific examples of the organopolysiloxane-free polyoxyalkylene chain-containing compound include, for example, polyoxyalkylene alkylamine, polyoxyalkylenediamine, polyoxyalkylene fatty acid ester, and polyoxyalkylene sorbitan. Nonionic surfactants, such as fatty acid ester, polyoxyalkylene alkylphenyl ether, polyoxyalkylene alkyl ether, polyoxyalkylene alkyl allyl ether, and polyoxyalkylene alkylphenyl allyl ether; anionic surfactants such as polyoxyalkylene alkyl ether sulfate salts, polyoxyalkylene alkyl ether phosphoric acid ester salts, polyoxyalkylene alkyl phenyl ether sulfate salts, and polyoxyalkylene alkyl phenyl ether phosphoric acid ester salts; In addition, cationic surfactants and amphoteric ionic surfactants having polyoxyalkylene chains (polyalkylene oxide chains), polyether compounds having polyoxyalkylene chains (and derivatives thereof are included), polyoxyalkyl and a polyester compound having a lene chain (and a derivative thereof), an acrylic compound having a polyoxyalkylene chain (including a derivative thereof), and the like. Moreover, you may mix|blend a polyoxyalkylene chain containing monomer with an acrylic polymer as a polyoxyalkylene chain containing compound. These polyoxyalkylene chain containing compounds may be used independently and may be used in combination of 2 or more type.

Specific examples of the polyether compound having a polyoxyalkylene chain include a block copolymer of polypropylene glycol (PPG)-polyethylene glycol (PEG), a block copolymer of PPG-PEG-PPG, and a block of PEG-PPG-PEG. A copolymer etc. are mentioned. As the derivative of the polyether compound having a polyoxyalkylene chain, a terminal etherified oxypropylene group-containing compound (PPG monoalkyl ether, PEG-PPG monoalkyl ether, etc.), a terminal acetylated oxypropylene group-containing compound (Terminal acetylated PPG etc.) etc. are mentioned.

Moreover, as a specific example of the acrylic compound which has the said polyoxyalkylene chain, the (meth)acrylate polymer which has an oxyalkylene group is mentioned. As said oxyalkylene group, 1-50 are preferable from a viewpoint in which the added mole number of an oxyalkylene unit coordinates an ionic compound, 2-30 are more preferable, 2-20 are still more preferable. In addition, the terminal of the said oxyalkylene group may be substituted with a hydroxyl group as it is, or an alkyl group, a phenyl group, etc.

The (meth)acrylate polymer having an oxyalkylene group is preferably a polymer containing (meth)acrylic acid alkylene oxide as a monomer unit (component), and specific examples of the (meth)acrylic acid alkylene oxide include , ethylene glycol group-containing (meth)acrylate, for example, methoxy-polyethylene glycol (eg, methoxy-diethylene glycol (meth) acrylate, methoxy-triethylene glycol (meth) acrylate) Ethoxy-polyethylene glycol (meth)acrylate type, such as meth)acrylate type, ethoxy-diethylene glycol (meth)acrylate, ethoxy-triethylene glycol (meth)acrylate, butoxy-diethylene glycol ( Butoxy-polyethylene glycol (meth) acrylate types such as meth) acrylate, butoxy-triethylene glycol (meth) acrylate, phenoxy-diethylene glycol (meth) acrylate, phenoxy-triethylene glycol (meth) ) Phenoxy-polyethylene glycol (meth) acrylate type such as acrylate, 2-ethylhexyl-polyethylene glycol (meth) acrylate, nonylphenol-polyethylene glycol (meth) acrylate type, methoxy-dipropylene glycol (meth) ) Methoxy-polypropylene glycol (meth)acrylate types, such as an acrylate, etc. are mentioned.

Moreover, as said monomeric unit (component), other monomeric units (component) other than the said (meth)acrylic-acid alkylene oxide can be used. Specific examples of other monomer units include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-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, n-tetradecyl The acrylate and/or methacrylate which have a C1-C14 alkyl group, such as (meth)acrylate, are mentioned.

In addition, as other monomer units (components) other than the said (meth)acrylic acid alkylene oxide, carboxyl group containing (meth)acrylate, phosphoric acid group containing (meth)acrylate, cyano group containing (meth)acrylate, vinyl esters, Aromatic vinyl compound, acid anhydride group-containing (meth)acrylate, hydroxyl group-containing (meth)acrylate, amide group-containing (meth)acrylate, amino group-containing (meth)acrylate, epoxy group-containing (meth)acrylate, N - It is also possible to appropriately use acryloylmorpholine, vinyl ethers, and the like.

In a preferable aspect, the polyoxyalkylene chain containing compound which does not contain the said organopolysiloxane is a compound which has a (poly) ethylene oxide chain in at least one part. By mix|blending the compound which has the said (poly) ethylene oxide chain|strand, the compatibility of a base polymer and an antistatic component is improved, bleed|bleed to a to-be-adhered body is suppressed suitably, and a low-staining adhesive composition can be obtained. Especially, when the block copolymer of PPG-PEG-PPG is used especially, the adhesive composition excellent in low contamination property can be obtained. As said polyethylene oxide chain containing compound, it is preferable that the mass of the (poly) ethylene oxide chain|strand occupied in the whole said compound is 5-90 mass %, More preferably, it is 5-85 mass %, More preferably, 5-80 mass %. % by mass, most preferably 5 to 75% by mass.

As molecular weight of the polyoxyalkylene chain containing compound which does not contain the said organopolysiloxane, it is preferable that a number average molecular weight (Mn) is 50,000 or less, 200-30,000 are more preferable, 200-10,000 are still more preferable, 200- 5,000 is particularly preferably used. When Mn is too large than 50,000, compatibility with an acrylic polymer falls and there exists a tendency for an adhesive layer to whiten. When Mn is too small than 200, it may become easy to produce contamination by the said polyoxyalkylene compound. In addition, Mn means the value of polystyrene conversion obtained by GPC (gel permeation chromatography) here.

In addition, the specific example as a commercial item of the polyoxyalkylene chain containing compound which does not contain the said organopolysiloxane is, for example, Adecapluronic 17R-4, Adecapluronic 25R-2 (above, all are ADEKA Corporation). manufacture), Emalgen 120 (made by Kao Corporation), etc. are mentioned.

The blending amount of the polyoxyalkylene chain-containing compound not containing the organopolysiloxane may be, for example, 0.005 to 20 parts by mass, preferably 0.01 to 10 parts by mass, based on 100 parts by mass of the (meth)acrylic polymer; More preferably, it is 0.05-5 mass parts, Most preferably, it is 0.1-1 mass part. When there is too little compounding quantity, the effect of preventing the bleed of an antistatic component may decrease, and when too large, it may become easy to produce contamination by the said polyoxyalkylene compound.

Moreover, you may contain an acryl oligomer in the said adhesive composition. As for the acrylic oligomer, 1,000 or more and less than 30,000 are preferable, their weight average molecular weights are more preferable, 1,500 or more and less than 20,000 are more preferable, and their 2,000 or more and less than 10,000 are still more preferable. When using for the acrylic adhesive composition for re-peelability of this embodiment, it functions as tackifying resin, improves adhesiveness (adhesiveness), and it is effective in lifting suppression of an adhesive sheet.

A (meth)acrylic acid ester monomer can be used for the said acrylic oligomer, For example, (meth)acrylic acid methyl, (meth)acrylate ethyl, (meth)acrylic acid propyl, (meth)acrylate isopropyl, (meth)acrylate butyl , (meth) acrylate isobutyl, (meth) acrylate s-butyl, (meth) acrylate t-butyl, (meth) acrylate pentyl, (meth) acrylate isopentyl, (meth) acrylate hexyl, (meth) acrylic acid-2- Ethylhexyl, (meth) acrylate heptyl, (meth) acrylate octyl, (meth) acrylate isooctyl, (meth) acrylate nonyl, (meth) acrylate isononyl, (meth) acrylate decyl, (meth) acrylate isodecyl, ( (meth)acrylic acid alkyl esters such as undecyl acrylate and dodecyl (meth)acrylate;

(meth)acrylic acid aryl esters such as (meth)acrylic acid phenyl and (meth)acrylic acid benzyl;

(meth)acrylic acid ester obtained from terpene compound derivative alcohol, etc. are mentioned.

In addition, as the acrylic oligomer, a (meth)acrylic monomer having an alicyclic structure can be used, for example, dicyclopentanyl methacrylate, dicyclopentanyl acrylate, dicyclopentanyloxyethyl methacrylate, dicyclo Fentanyloxyethyl acrylate, tricyclofentanyl methacrylate, tricyclofentanyl acrylate, 1-adamantyl methacrylate, 1-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate, 2 (meth)acrylic acid esters, such as -methyl-2- adamantyl acrylate, 2-ethyl-2- adamantyl methacrylate, and 2-ethyl-2- adamantyl acrylate, etc. are mentioned. These (meth)acrylic monomers can be used individually or in combination of 2 or more types.

In addition, the acrylic oligomer may be obtained by copolymerizing another monomer component (copolymerizable monomer) copolymerizable with the (meth)acrylic monomer in addition to the (meth)acrylic monomer component unit.

The weight average molecular weight of the acrylic oligomer is 1,000 or more and less than 30,000, preferably 1,500 or more and less than 20,000, and more preferably 2,000 or more and less than 10,000. When the weight average molecular weight is 30,000 or more, adhesiveness (adhesiveness) decreases. Moreover, since it becomes a low molecular weight that a weight average molecular weight is less than 1,000, the fall of the adhesive force of an adhesive sheet is caused.

Further, the pressure-sensitive adhesive composition may contain a compound having keto-enol tautomerism as a crosslinking retardant. For example, in a pressure-sensitive adhesive composition containing a crosslinking agent or a pressure-sensitive adhesive composition that can be used by mixing a crosslinking agent, an embodiment including a compound having keto-enol tautomerism may be preferably employed. Thereby, the effect of suppressing an excessive viscosity rise and gelation of the adhesive composition after crosslinking agent mix|blending, and extending the pot life of an adhesive composition can be implement|achieved. In the case of using at least an isocyanate compound as the crosslinking agent, it is particularly significant to contain a compound that exhibits keto-enol tautomerism. This technique can be preferably applied, for example, when the pressure-sensitive adhesive composition is in the form of an organic solvent solution or no solvent.

As the compound in which the keto-enol tautomerism occurs, various β-dicarbonyl compounds can be used. Specific examples include acetylacetone, 2,4-hexanedione, 3,5-heptanedione, 2-methylhexane-3,5-dione, 6-methylheptane-2,4-dione, 2,6-dimethylheptane β-diketones such as -3,5-dione; acetoacetic acid esters such as methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, and tert-butyl acetoacetate; propionyl acetate esters such as ethyl propionyl acetate, ethyl propionyl acetate, isopropyl propionyl acetate, and tert-butyl propionyl acetate; isobutyryl acetate esters such as ethyl isobutyryl acetate, ethyl isobutyryl acetate, isopropyl isobutyryl acetate, and tert-butyl isobutyryl acetate; Malonic acid esters, such as methyl malonate and ethyl malonate, etc. are mentioned. Among them, acetylacetone and acetoacetic acid esters are mentioned as suitable compounds. The compounds in which such keto-enol tautomerism occurs may be used alone or in combination of two or more.

The content of the keto-enol tautomer compound can be, for example, 0.1 to 20 parts by mass, and usually 0.5 to 15 parts by mass (eg, 1 to 10 parts by mass) with respect to 100 parts by mass of the (meth)acrylic polymer. It is appropriate to do When there is too little quantity of the said compound, it may become difficult to exhibit sufficient use effect. On the other hand, when the compound is used more than necessary, it may remain in the pressure-sensitive adhesive layer to reduce the cohesive force.

In addition, the adhesive composition used for the adhesive sheet of this invention may contain other well-known additives, For example, powders, such as a coloring agent, a pigment, surfactant, a plasticizer, a tackifier, a low molecular weight polymer, the surface Lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, ultraviolet absorbers, polymerization inhibitors, silane coupling agents, inorganic or organic fillers, metal powders, particulates, foils, etc. can be appropriately added depending on the intended use.

The pressure-sensitive adhesive sheet of the present invention is characterized in that it has a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (formed by crosslinking the pressure-sensitive adhesive composition) on one side or both sides of the support film, but in that case, the crosslinking of the pressure-sensitive adhesive composition is Although carrying out after application|coating is common, it is also possible to transcribe|transfer the adhesive layer which consists of the adhesive composition after bridge|crosslinking, a support film etc. In addition, the method of forming the pressure-sensitive adhesive layer on the support film is not particularly limited. For example, the pressure-sensitive adhesive composition is applied to the support film, the polymerization solvent is dried and removed to form the pressure-sensitive adhesive layer on the support film. do. Then, you may cure for the purpose of adjustment of the component migration of an adhesive layer, adjustment of a crosslinking reaction, etc. Moreover, when apply|coating an adhesive composition on a support film and producing an adhesive sheet, you may newly add 1 or more types of solvents other than a polymerization solvent in the said adhesive composition so that it may apply|coat uniformly on a support film.

In addition, as a formation method of the adhesive layer at the time of manufacturing the adhesive sheet of this invention, the well-known method used for manufacture of adhesive sheets is used. Specific examples thereof include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, and extrusion coating using a die coater.

Usually, it is preferable that the thickness of the said adhesive layer is 3-100 micrometers, and, as for the adhesive sheet of this invention, it produces so that it may become about 5-50 micrometers more preferably. When the thickness of an adhesive layer exists in the said range, since it is easy to obtain the balance of moderate re-peelability and adhesiveness (adhesiveness), it is preferable.

<Separator>

To the adhesive sheet (surface protection film) of this invention, it is possible to bond a separator to the adhesive layer surface for the purpose of protecting an adhesive surface as needed.

Although there exist paper and a plastic film as a material which comprises the said separator, a plastic film is used suitably at the point which is excellent in surface smoothness. The film is not particularly limited as long as it is a film capable of protecting the pressure-sensitive adhesive layer, and for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, chloride A vinyl copolymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, an ethylene-vinyl acetate copolymer film, etc. are mentioned.

The thickness of the separator is usually 5 to 200 µm, preferably about 10 to 100 µm. When it exists in the said range, since it is excellent in the bonding workability|operativity with respect to an adhesive layer, and peeling workability|operativity from an adhesive layer, it is preferable. If necessary, the separator may be treated with a silicone-based, fluorine-based, long-chain alkyl or fatty acid amide-based mold release agent, silica powder, etc. .

The pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition on one or both sides of a support film, and the peeling rate after adhering the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer to the TAC surface at 23° C. for 30 minutes is 30 m The adhesive force ratio (B/A) of the adhesive force (A) at /min and the adhesive force (B) at a peeling rate of 30 m/min after adhering the adhesive surface of the pressure-sensitive adhesive layer to the TAC surface at 70 ° C. for 1 week is less than 2 , Preferably it is 0.5-1.9, More preferably, it is 0.7-1.8. By being in the said range, also at the time of high-speed peeling after high temperature aging, it is excellent in adhesive force rise prevention property (adhesive force stability), and it is excellent in re-peelability and workability, and it becomes a preferable aspect.

Further, the adhesive force (A) at a peeling rate of 30 m/min after adhering the adhesive surface of the pressure-sensitive adhesive layer to the TAC surface at 23° C. for 30 minutes is preferably 2.0 N/25 mm or less, more preferably 0.1 to It is 1.9 N/25 mm, More preferably, it is 0.1-1.8 N/25 mm. When the adhesive force (A) exceeds 2.0 N/25 mm, it becomes difficult to peel the adhesive sheet (surface protection film) from the adherend, and the peeling workability when the adhesive sheet is no longer required is poor, and further, the peeling process can prevent It is unpreferable in order to give damage etc. to a complex.

The adhesive force (B) at a peeling rate of 30 m/min after bonding the adhesive surface of the pressure-sensitive adhesive layer to the TAC surface at 70° C. for 1 week is preferably less than 4.0 N/25 mm, more preferably 0.1 to 3.5 N /25 mm, more preferably 0.1 to 3.0 N/25 mm. When the adhesive force (B) is 4.0 N/25 mm or more, the pressure-sensitive adhesive sheet (surface protection film) is difficult to peel from the adherend, and the peeling workability when the pressure-sensitive adhesive sheet is no longer required is poor, and further, the peeling process can prevent It is unpreferable in order to give damage etc. to a complex.

In addition, in the adhesive sheet of the present invention, the adhesive strength (A) at a peeling rate of 30 m/min after adhering the adhesive surface of the pressure-sensitive adhesive layer to the TAC surface at 23° C. for 30 minutes and the adhesive surface of the pressure-sensitive adhesive layer to the TAC surface of 70 The adhesive force ratio (B/A) of the adhesive force (B) at the peeling rate of 30 m/min after adhesion|attaching at °C for 1 week is less than 2, Preferably it is 0.5-1.9, More preferably, it is 0.7-1.8. By being in the said range, it is excellent in re-peelability and workability|operativity, and becomes a preferable aspect.

In addition, the pressure-sensitive adhesive sheet of the present invention is a shear force when 1 cm 2 of the adhesive area of the pressure-sensitive adhesive layer is bonded to a TAC polarizing plate and peeled in the shear direction at a peeling rate of 0.06 mm/min after adhesion at 23° C. for 30 minutes, 10 N /cm2 or more is preferable, More preferably, it is 10-50 N/cm<2>, More preferably, it is 10-40 N/cm<2>. If the shear force is within the above range, it is preferable because it can withstand the force in the shear direction that occurs when the adherend tends to curl, so that slip or distortion of the adhesive sheet does not occur, and curl of the adherend can be suppressed. .

<Antistatic layer (top coat layer)>

The pressure-sensitive adhesive sheet of the present invention has an antistatic layer on one side of the support film opposite to the pressure-sensitive adhesive layer, and the antistatic layer comprises polyanilinesulfonic acid as a conductive polymer component, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent. It is preferable to form from the antistatic agent composition containing. When the said adhesive sheet has an antistatic layer (topcoat layer), the antistatic property of an adhesive sheet improves, and it becomes a preferable aspect.

<Conductive Polymer>

It is preferable that the said antistatic layer contains polyanilinesulfonic acid as a conductive polymer component. By using the said conductive polymer, the antistatic property based on an antistatic layer can be satisfied. Moreover, although the said polyanilinesulfonic acid is "water-soluble", by using the isocyanate type crosslinking agent mentioned later, it can be fixed in the antistatic layer, and water resistance can be improved. By using the said water-soluble conductive polymer containing aqueous solution, the antistatic layer excellent in the surface resistance value over time can be obtained, and it becomes a preferable aspect. On the other hand, when the conductive polymer used when forming the antistatic layer is "water-dispersible", when the antistatic layer is formed using the water-dispersible conductive polymer-containing solution, aggregates are likely to occur and uniform coating cannot be achieved, and It is not preferable because the surface resistance value tends to drop remarkably with the passage of time.

The amount of the conductive polymer used is preferably 10 to 200 parts by mass, more preferably 25 to 150 parts by mass, and still more preferably 40 to 120 parts by mass based on 100 parts by mass of the binder contained in the antistatic layer (topcoat layer). is wealth When the amount of the conductive polymer used is too small, the antistatic effect may become small. When the amount of the conductive polymer used is too large, the adhesion of the antistatic layer to the support film may decrease or transparency may decrease, which is not preferable.

The polyanilinesulfonic acid used as the conductive polymer component preferably has a weight average molecular weight (Mw) in terms of polystyrene of 5×10 ⁵ or less, more preferably 3×10 ^{5 or less.} Moreover, it is preferable that the weight average molecular weight of these conductive polymers is usually 1x10 ³ or more, More preferably, it is 5x10 ³ or more.

As a method of forming the antistatic layer, a method of applying and drying (or curing) a coating material for forming an antistatic layer (antistatic agent composition) to the first surface of the support film can be adopted, and a conductive polymer used for preparing the coating material The component preferably contains polyanilinesulfonic acid, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent, preferably a form in which the above essential components are dissolved in water (referred to as an aqueous solution of a conductive polymer or simply an aqueous solution). Can be used. Such an aqueous conductive polymer solution can be prepared, for example, by dissolving a conductive polymer having a hydrophilic functional group (which can be synthesized by a method such as copolymerizing a monomer having a hydrophilic functional group in a molecule) in water. Examples of the hydrophilic functional group include a sulfo group, an amino group, an amide group, an imino group, a hydroxyl group, a mercapto group, a hydrazino group, a carboxyl group, a quaternary ammonium group, a sulfuric acid ester group (-O—SO ₃ H), and a phosphoric acid ester group. (For example, -O-PO(OH) ₂ ) etc. are illustrated. Such a hydrophilic functional group may form a salt.

Moreover, as a commercial item of the said polyaniline sulfonic acid aqueous solution, the Mitsubishi Rayon company brand name "aquaPASS" etc. are illustrated.

The antistatic layer disclosed herein contains polyanilinesulfonic acid (polyaniline type) as an essential component as a conductive polymer component, but for example, one or two or more other antistatic components (organic conductive substances other than conductive polymers, inorganic conductive materials) substances, antistatic agents, etc.) may be included. Moreover, as a preferable aspect, the aspect which the said antistatic layer does not contain antistatic components other than the said conductive polymer substantially, ie, the aspect which the antistatic component contained in the said antistatic layer consists substantially only of a conductive polymer is more preferable. can be carried out.

Examples of the organic conductive material include a cationic antistatic agent having a cationic functional group such as a quaternary ammonium salt, a pyridinium salt, a first amino group, a second amino group, and a tertiary amino group; anionic antistatic agents having anionic functional groups such as sulfonic acid salts, sulfate salts, phosphonate salts and phosphoric acid ester salts; zwitterionic antistatic agents such as alkylbetaine and derivatives thereof, imidazoline and derivatives thereof, alanine and derivatives thereof; Nonionic antistatic agents, such as amino alcohol and its derivative(s), glycerol and its derivative(s), polyethyleneglycol, and its derivative(s); an ion conductive polymer obtained by polymerizing or copolymerizing a monomer having an ion conductive group (eg, a quaternary ammonium base) of the cation type, anionic type, or amphoteric ion type; and conductive polymers such as polythiophene, polyaniline, polypyrrole, polyethyleneimine, and allylamine polymers. These antistatic agents may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the inorganic conductive material include tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, cobalt, iodide. Copper, ITO (indium oxide/tin oxide), ATO (antimony oxide/tin oxide), etc. are mentioned. These inorganic conductive substances may be used individually by 1 type, and may be used in combination of 2 or more type.

As the antistatic agent, a cationic antistatic agent, an anionic antistatic agent, an amphoteric ionic antistatic agent, a nonionic antistatic agent, a monomer having an ionic conductive group of the cationic, anionic, or amphoteric ionic groups is polymerized or copolymerized. The obtained ion conductive polymer etc. are mentioned.

<Binder>

It is preferable that the said antistatic layer contains a polyester resin as a binder. It is preferable that the polyester resin is a resin material containing polyester as a main component (typically a component that accounts for more than 50 mass%, preferably 75 mass% or more, such as 90 mass% or more). The polyester is typically one selected from polyhydric carboxylic acids having two or more carboxyl groups in one molecule (typically dicarboxylic acids) and derivatives thereof (anhydrides, esters, halides, etc. of polyhydric carboxylic acids) or two or more compounds (polyhydric carboxylic acid component) and one or more compounds (polyhydric alcohol component) selected from polyhydric alcohols (typically diols) having two or more hydroxyl groups in one molecule are condensed It is preferable to have one structure.

Examples of the compound that can be employed as the polyvalent carboxylic acid component include oxalic acid, malonic acid, difluoromalonic acid, alkylmalonic acid, succinic acid, tetrafluorosuccinic acid, alkylsuccinic acid, (±)-malic acid, meso-tartaric acid, it Conic acid, maleic acid, methyl maleic acid, fumaric acid, methyl fumaric acid, acetylenedicarboxylic acid, glutaric acid, hexafluoroglutaric acid, methyl glutaric acid, glutaconic acid, adipic acid, dithioadipic acid, methyl adipic acid Acid, dimethyladipic acid, tetramethyladipic acid, methyleneadipic acid, muconic acid, galactaric acid, pimelinic acid, suberic acid, perfluorosuberic acid, 3,3,6,6-tetramethyl aliphatic dicarboxylic acids such as suberic acid, azelaic acid, sebacic acid, perfluorosebacic acid, brassylic acid, dodecyldicarboxylic acid, tridecyldicarboxylic acid, and tetradecyldicarboxylic acid; Cycloalkyldicarboxylic acid (eg, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid), 1,4-(2-norbornene)dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid alicyclic dicarboxylic acids such as (hymic acid), adamantane dicarboxylic acid, and spiroheptane dicarboxylic acid; Phthalic acid, isophthalic acid, dithioisophthalic acid, methylisophthalic acid, dimethylisophthalic acid, chloroisophthalic acid, dichloroisophthalic acid, terephthalic acid, methylterephthalic acid, dimethylterephthalic acid, chloroterephthalic acid, bromoterephthalic acid, naphthalenedicarboxylic acid, octofluorenedicarboxylic acid Anthracene dicarboxylic acid, biphenyl dicarboxylic acid, biphenylenedicarboxylic acid, dimethylbiphenylenedicarboxylic acid, 4,4''-p-terephenylenedicarboxylic acid, 4,4''-p-quwarelphenyldicarboxylic acid, bibenzyl Dicarboxylic acid, azobenzenedicarboxylic acid, homophthalic acid, phenylenediacetic acid, phenylenedipropionic acid, naphthalenedicarboxylic acid, naphthalenedipropionic acid, biphenyldiacetic acid, biphenyldipropionic acid, 3,3'-[4,4'-(methylene) Aromatic di-p-phenylene dipropionic acid, such as 4,4'-bibenzyl diacetic acid, 3,3' (4,4'-bibenzyl) dipropionic acid, and oxydi-p-phenylene diacetic acid carboxylic acids; acid anhydride of any of the above-mentioned polyhydric carboxylic acids; esters of any of the foregoing polyhydric carboxylic acids (eg, alkyl esters, may be monoesters, diesters, etc.); and acid halides corresponding to any of the above polyvalent carboxylic acids (eg, dicarboxylic acid chloride).

Preferable examples of the compound that can be employed as the polyvalent carboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid and acid anhydrides thereof; aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, succinic acid, fumaric acid, maleic acid, hymic acid, and 1,4-cyclohexanedicarboxylic acid and acid anhydrides thereof; and lower alkyl esters of the aforementioned dicarboxylic acids (eg, esters with monoalcohols having 1 to 3 carbon atoms).

Meanwhile, examples of the compound that can be employed as the polyhydric alcohol component include ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and neopentyl. Glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 2-methyl- 1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, xylylene glycol, hydrogenated bisphenol A, bisphenol A, etc. Diols are mentioned. As another example, alkylene oxide adducts (eg, ethylene oxide adduct, propylene oxide adduct, etc.) of these compounds are mentioned.

^{The molecular weight of the polyester resin is, for example, about 5×10 3 to} 1.5×10 ⁵ (preferably 1×10) as a weight average molecular weight (Mw) in terms of standard polystyrene measured by gel permeation chromatography (GPC). ⁴ to 6×10 ⁴ ). In addition, the glass transition temperature (Tg) of the polyester resin may be, for example, 0 to 120 ℃ (preferably 10 to 80 ℃).

As said polyester resin, the commercially available Toyobo company brand name "Villonal MD-1480" etc. can be used.

The antistatic layer (topcoat layer) is a resin other than a polyester resin as a binder to the extent that the performance (eg, performance, such as antistatic property) of the pressure-sensitive adhesive sheet (surface protection film) disclosed herein is not significantly impaired. (For example, one or more resins selected from acrylic resins, acrylic-urethane resins, acrylic-styrene resins, acrylic-silicone resins, silicone resins, polysilazane resins, polyurethane resins, fluororesins, polyolefin resins, etc.) may contain more. In a preferred embodiment of the technology disclosed herein, the binder of the antistatic layer is substantially composed of only a polyester resin. For example, the antistatic layer in which the ratio of the polyester resin to a binder is 98-100 mass % is preferable. The proportion of the binder in the entire antistatic layer can be, for example, 50 to 95 mass%, and usually 60 to 90 mass% is suitable.

<Lubrication>

The antistatic layer (topcoat layer) preferably uses a fatty acid amide as a lubricant. By using a fatty acid amide as a lubricant, the surface of the antistatic layer is not subjected to a peeling treatment (for example, a treatment in which a known release treatment agent such as a silicone-based release agent or a long-chain alkyl-based release agent is applied and dried) is not further applied. Since it is possible to obtain an antistatic layer (topcoat layer) with both adhesiveness compatible, it can be a preferable aspect. The aspect in which the peeling process is not further given to the surface of the antistatic layer in this way is preferable from the viewpoint of being able to prevent in advance the whitening resulting from the peeling agent (for example, whitening by storing under heating and humidification conditions). Moreover, it is advantageous also from the point of solvent resistance.

Specific examples of the fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, oleic acid amide, erucic acid amide, N-oleyl palmitic acid amide, N -Stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, methylol stearic acid amide, methylenebis stearic acid amide, ethylene biscapric acid amide, ethylene Bislauric acid amide, ethylene bis stearic acid amide, ethylene bis hydroxy stearic acid amide, ethylene bis behenic acid amide, hexamethylene bis stearic acid amide, hexamethylene bis behenic acid amide, hexamethylene hydroxy stearic acid amide, N, N'-distearyl adipic acid amide, N,N'-distearyl sebacin amide, ethylenebisoleic acid amide, ethylenebiserucic acid amide, hexamethylenebisoleic acid amide, N,N'-dioleyl adipic acid amide, N,N'-dioleyl sebacinamide, m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, N,N'-stearylisophthalic acid amide, etc. are mentioned. . These lubricants may be used individually by 1 type, and may be used in combination of 2 or more type.

The proportion of the lubricant in the entire antistatic layer can be 1 to 50 mass%, and usually 5 to 40 mass% is suitable. When there is too little content rate of a lubricant, there exists a tendency for slip property to fall easily. When there is too much content rate of a lubricant, printing adhesiveness may fall.

The technology disclosed herein may be implemented in such a way that the antistatic layer (topcoat layer) contains another lubricant in addition to the fatty acid amide, as long as the application effect is not significantly impaired. Examples of such other lubricants include various waxes such as petroleum waxes (paraffin wax, etc.), mineral waxes (montan wax, etc.), higher fatty acids (serotinic acid, etc.), and neutral fats (palmitic acid triglyceride, etc.). Alternatively, in addition to the wax, a general silicone-based lubricant, a fluorine-based lubricant, or the like may be supplemented. The technology disclosed herein may be preferably implemented in an embodiment that does not substantially contain such silicone-based lubricants, fluorine-based lubricants, and the like. However, to the extent that the application effect of the technology disclosed herein is not significantly impaired, excluding the silicone-based compound used for a purpose separate from the lubricant (for example, as an antifoaming agent of a coating material for forming an antistatic layer to be described later) is excluded. no.

<crosslinking agent>

It is preferable that the said antistatic layer contains an isocyanate type crosslinking agent as a crosslinking agent. By using the isocyanate-based crosslinking agent, water-soluble polyanilinesulfonic acid, which is an essential component, can be immobilized in a binder when forming the antistatic layer, so that it is excellent in water resistance, and effects such as improvement of print adhesion can be realized.

As said isocyanate-type crosslinking agent, it is a preferable aspect to use the blocked isocyanate type crosslinking agent stable in aqueous solution. Specific examples of the blocked isocyanate-based crosslinking agent include an isocyanate-based crosslinking agent that can be used in the preparation of a general pressure-sensitive adhesive layer or antistatic layer (topcoat layer) (e.g., an isocyanate compound used in the above-described pressure-sensitive adhesive layer (isocyanate-based crosslinking agent)) Alcohols, phenols, thiophenols, amines, imides, oximes, lactams, active methylene compounds, mercaptans, imines, ureas, diaryl compounds and sodium bisulfite can be used. have.

The antistatic layer in the technology disclosed herein is, if necessary, an antistatic component, an antioxidant, a colorant (pigment, dye, etc.), a fluidity modifier (thixotropic agent, thickener, etc.), a film forming aid, a surfactant (antifoaming agent, etc.) , and may contain additives such as preservatives.

<Formation of antistatic layer>

The antistatic layer (topcoat layer) is provided with a liquid composition (coating material for forming an antistatic layer) in which essential components such as the conductive polymer component and optionally used additives are dissolved in a suitable solvent (water, etc.) to the support film. It can be suitably formed by a method including For example, the method of applying the said coating material to the 1st surface of a support film, drying, and performing hardening treatment (heat treatment, ultraviolet treatment, etc.) as needed can be employ|adopted preferably. The NV (non-volatile content) of the coating material can be, for example, 5 mass % or less (typically 0.05 to 5 mass %), and is usually 1 mass % or less (typically 0.10 to 1 mass %). do. In the case of forming an antistatic layer having a small thickness, it is preferable that the NV of the coating material be, for example, 0.05 to 0.50 mass% (eg 0.10 to 0.40 mass%). As such, by using the low NV coating material, a more uniform antistatic layer can be formed.

As the solvent constituting the coating material for forming the antistatic layer, it is preferable that the component forming the antistatic layer can be stably dissolved. Such a solvent may be an organic solvent, water, or a mixed solvent thereof. Examples of the organic solvent include esters such as ethyl acetate; ketones such as methyl ethyl ketone, acetone, and cyclohexanone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol and cyclohexanol; One or two or more selected from glycol ethers such as alkylene glycol monoalkyl ether (eg, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether) and dialkylene glycol monoalkyl ether can be used. In a preferred embodiment, the solvent of the coating material is water or a mixed solvent containing water as a main component (eg, a mixed solvent of water and ethanol).

<Properties of the antistatic layer>

The thickness of the antistatic layer is typically 3 to 500 nm, preferably 3 to 100 nm, more preferably 3 to 60 nm. When the thickness of the antistatic layer is too small, it becomes difficult to form the antistatic layer uniformly (for example, in the thickness of the antistatic layer, the variation in thickness depending on location becomes large), and for this reason, the appearance of the pressure-sensitive adhesive sheet (surface protection film) There may be cases where it is easy to cause non-uniformity. On the other hand, when too thick, the characteristic (optical characteristic, dimensional stability, etc.) of a support film may be affected.

In one preferred aspect of the pressure-sensitive adhesive sheet (surface protection film) disclosed herein, the surface resistance value (Ω/□) measured on the surface of the antistatic layer is preferably ^{less than 1.0×10 11} , more preferably It is less than 5.0×10 ¹⁰ , and more preferably less than ^{2.0×10 10 .} The pressure-sensitive adhesive sheet exhibiting a surface resistance value within the above range can be suitably used as a pressure-sensitive adhesive sheet used in, for example, a process or conveyance process of an article that does not like static electricity, such as a liquid crystal cell or a semiconductor device. In addition, the said surface resistance value is computable from the surface resistance value measured in 23 degreeC and 50 %RH atmosphere using a commercially available insulation resistance measuring apparatus.

The pressure-sensitive adhesive sheet (surface protection film) disclosed herein has a property that the back side (surface of the antistatic layer) can be printed easily with water-based ink or oil-based ink (eg, using an oil-based marking pen). desirable. Such an adhesive sheet is suitable for describing and displaying the identification number of an adherend to be protected, etc. on the adhesive sheet in a process such as processing or conveying of an adherend (eg, optical component) performed in a state in which the adhesive sheet is adhered. do. Therefore, it is preferable that it is an adhesive sheet excellent in printing properties. For example, it is preferable that the solvent is alcohol-based and has high printability with respect to an oil-based ink of a type containing a pigment. Further, it is preferable that the printed ink is less likely to come off due to friction or electrodeposition (that is, excellent print adhesion). The pressure-sensitive adhesive sheet disclosed herein preferably also has solvent resistance to such an extent that, when printing is corrected or erased, no noticeable change in appearance occurs even if the printing is wiped off with alcohol (eg, ethyl alcohol).

The pressure-sensitive adhesive sheet (surface protection film) disclosed herein may also be implemented in an embodiment including another layer in addition to the support film (base material), the pressure-sensitive adhesive layer and the antistatic layer. As arrangement of such "another layer", between the 1st surface (back side) of a support film and an antistatic layer, between the 2nd surface (front surface) of a support film, and an adhesive layer, etc. are illustrated. The layer disposed between the front surface of the support film and the pressure-sensitive adhesive layer may be, for example, an undercoat layer (anchor layer), an antistatic layer, or the like, which enhances anchoring properties of the pressure-sensitive adhesive layer to the second surface. An antistatic layer is arrange|positioned on the entire surface of a support film, an anchor layer is arrange|positioned on the antistatic layer, and the adhesive sheet of the structure by which the adhesive layer was arrange|positioned may be sufficient.

It is preferable that the optical member of this invention is what was protected by the said adhesive sheet. The pressure-sensitive adhesive sheet can prevent an increase in adhesive strength over time (at high temperature), has low adhesive strength during high-speed peeling, and is excellent in re-peelability and workability, so Since it can be used for a surface protection application, it becomes useful in order to protect the surface of the said optical member (polarizing plate etc.). Moreover, since the said adhesive sheet is excellent in shearing force, it can suppress the curl of the to-be-adhered body (optical member) to which the said adhesive sheet was joined, and since it is excellent in handleability, it becomes useful.

Example

Hereinafter, examples and the like specifically showing the configuration and effects of the present invention will be described, but the present invention is not limited thereto. In addition, about the compounding content and characteristic evaluation in an Example etc., it measured as follows. In addition, in Table 1, the physical property value of the (meth)acrylic polymer used for the pressure-sensitive adhesive composition and the mixing ratio of the pressure-sensitive adhesive composition are shown, and in Table 2, the content of the antistatic layer is shown, and in Table 3, the evaluation of properties showed results.

<Evaluation>

A specific measurement and evaluation method is described below.

<Measurement of weight average molecular weight (Mw)>

The weight average molecular weight (Mw) was measured using the Tosoh Corporation GPC apparatus (HLC-8220GPC). Measurement conditions are as follows.

Sample concentration: 0.2% by mass (THF solution)

Sample injection volume: 10 μl

Eluent: THF

Flow rate: 0.6 ml/min

Measuring temperature: 40℃

column:

sample column; TSKguardcolumn SuperHZ-H (1 pc.) + TSKgel SuperHZM-H (2 pc.)

reference column; TSKgel SuperH-RC (1 pc.)

Detector: Differential Refractometer (RI)

In addition, the weight average molecular weight was calculated|required by polystyrene conversion value.

<Theoretical value of glass transition temperature>

The glass transition temperature Tg (°C) was obtained by the following formula using the following literature value as the glass transition temperature Tgn (°C) of the homopolymer of each monomer.

Equation: 1/(Tg+273)=Σ[Wn/(Tgn+273)]

[Wherein, Tg (℃) is the glass transition temperature of the copolymer, Wn (-) is the mass fraction of each monomer, Tgn (℃) is the glass transition temperature of the homopolymer by each monomer, n is the type of each monomer indicates. ]

Literature value:

2-ethylhexyl acrylate (2EHA): -70°C

n-Butylacrylate (BA): -55°C

Acrylic acid (AA): 106°C

Carboxylethylacrylate (β-CEA): 37°C

2-Hydroxyethyl acrylate (HEA): -15°C

4-Hydroxybutylacrylate (HBA): -32°C

Hydroxyethyl methacrylate (HEMA): 55°C

N,N-diethylacrylamide (DEAA): 81°C

In addition, as literature values, "synthesis, design, and credibility development of acrylic resins" (published by the Central Management Development Center Publishing Department) and "Polymer Handbook" (John Wiley & Sons) were referred to.

<Measurement of initial adhesive force (A)>

TAC polarizing plate (manufactured by Nitto Electric Corporation, SEG1423DU polarizing plate, width: 70 mm, length: 100 mm) was left under an environment of 23°C×50%RH for 24 hours, and then the adhesive sheet cut to 25 mm in width and 100 mm in length was removed. An evaluation sample was prepared by laminating the adherend at a pressure of 0.25 MPa and a speed of 0.3 m/min.

After the lamination, the initial adhesive force (A) (N /25 mm). The measurement was performed in the environment of 23 degreeC x 50%RH.

Moreover, as for the said adhesive force (A), 2.0 N/25 mm or less is preferable, More preferably, it is 0.1-1.9 N/25 mm, More preferably, it is 0.1-1.8 N/25 mm. When the adhesive force (A) exceeds 2.0 N/25 mm, the pressure-sensitive adhesive sheet (surface protection film) is difficult to peel from the adherend, and the peeling workability when the pressure-sensitive adhesive sheet becomes unnecessary is poor, and further, the peeling process It is undesirable in order to give damage etc. to a to-be-adhered body.

<Measurement of adhesive strength (B) over high temperature>

TAC polarizing plate (manufactured by Nitto Electric Corporation, SEG1423DU polarizing plate, width: 70 mm, length: 100 mm) was left under an environment of 23°C×50%RH for 24 hours, and then the adhesive sheet cut to 25 mm in width and 100 mm in length was removed. An evaluation sample was prepared by laminating the adherend at a pressure of 0.25 MPa and a speed of 0.3 m/min.

After the lamination, the adhesive strength over time (B) (N) when the laminate was left for 1 week (7 days) in an environment of 70 ° C. /25 mm). The measurement was performed in the environment of 23 degreeC x 50%RH.

Moreover, as for the said adhesive force (B), less than 4.0 N/25 mm is preferable, More preferably, it is 0.1-3.5 N/25 mm, More preferably, it is 0.1-3.0 N/25 mm. When the adhesive force (B) is 4.0 N/25 mm or more, the pressure-sensitive adhesive sheet (surface protection film) is difficult to peel from the adherend, and the peeling workability when the pressure-sensitive adhesive sheet is no longer required is poor, and further, the peeling process can prevent It is unpreferable in order to give damage etc. to a complex.

<Evaluation of adhesive force ratio (B/A)>

The adhesive force ratio (B/A) of the said adhesive force (A) and the said adhesive force (B) is less than 2, Preferably it is 0.5-1.9, More preferably, it is 0.7-1.8. By being in the said range, it is excellent in re-peelability and workability|operativity, and becomes a preferable aspect. In addition, the said adhesive force ratio is evaluated as an index|index of the raise prevention property of the adhesive force in high temperature aging.

<Measurement of shear force>

After the pressure-sensitive adhesive sheet was cut to a size of 10 mm in width and 100 mm in length and the separator was peeled off, a TAC polarizing plate (manufactured by Nitto Electric Corporation, SEG1423DU polarizing plate, Width: 25 mm, length: 100 mm), after standing for 30 minutes at room temperature (23°C x 50%RH), pulled in the shear direction at a peeling rate of 0.06 mm/min, and the maximum load at that time (N/ cm2) was used as the shear force.

Moreover, as for the said shearing force (N/cm<2>), 10 or more are preferable, More preferably, it is 10-50, More preferably, it is 10-40. If the shear force is within the above range, it is preferable because it can withstand the force in the shear direction that occurs when the adherend tends to curl, so that slip or distortion of the adhesive sheet does not occur, and curl of the adherend can be suppressed. .

<Measurement of surface resistance value>

It measured according to JIS-K-6911 using the resistivity meter (The Mitsubishi Chemical Analytech make, Hirestar UP MCP-HT450 type|mold) in the atmosphere of temperature 23 degreeC, and humidity 50%RH.

In the present invention, the surface resistance value (Ω/□) of the surface of the antistatic layer is preferably 1.0 × 10 in both the initial stage and at room temperature (23° C. × 50% RH) × 1 week (7 days) when left still. ^{It is} less than 11, More preferably, it is ^{less than 5.0 x 10 10} , More preferably, it is less than ^{2.0 x 10 10.} The pressure-sensitive adhesive sheet (surface protection film) exhibiting a surface resistance value within the above range can be suitably used as a pressure-sensitive adhesive sheet used in, for example, a process or conveyance process of an article that does not like static electricity, such as a liquid crystal cell or a semiconductor device.

<Measurement of slip property (dynamic friction)>

The adhesive sheet (surface protection film) was cut to a size of 70 mm in width and 100 mm in length, and an acrylic plate (manufactured by Mitsubishi Rayon, trade name "Acrylite", thickness: 1 mm, width: 70 mm, length: 100 mm) was joined to prepare a test piece. The back surface (antistatic layer surface) of this test piece was turned down, it was set on the smooth PET film hold|maintained horizontally, and 1.5 kg of load was mounted on the test piece. The test piece loaded with the load is attached to a tensile tester using a non-stretchable thread, and the test piece is horizontally pulled under the conditions of a tensile speed of 300 mm/min and a tensile distance of 300 mm at a measurement temperature of 25°C, and applied to the test piece. The average value (n=3) of the dynamic friction force (N) was obtained.

Moreover, as slipperiness (dynamic friction force) (N) in this invention, Preferably it is 5 or less, More preferably, it is 4.5 or less, More preferably, it is 4 or less. If it exists in the said range, when handling the to-be-adhered body which adhere|attached the adhesive sheet, if the slip property of the back surface of a support film (antistatic layer surface) is favorable, it will become advantageous at the point of workability|operativity.

<Evaluation of printing properties (printing adhesion)>

After printing on the surface of the antistatic layer using an X stamper manufactured by Shachihata under a measurement environment of 23°C x 50%RH, Cellotape (registered trademark) manufactured by Nichiban Corporation was adhered from the top of the printing, followed by peeling It peels under the conditions of a speed of 30 m/min and a peeling angle of 180 degrees. After that, the surface after peeling was observed with the naked eye, and the case where 50% or more of the printing area was peeled off was designated as x (printing quality), and the case where 50% or more of the printing area remained without peeling was designated as ○ (printing property good). evaluated.

<Preparation method>

Below, the preparation methods, such as a specific (meth)acrylic-type polymer and an adhesive composition, are described.

<Preparation of (meth)acrylic polymer>

94.5 parts by mass of 2-ethylhexyl acrylate (2EHA), 5.32 parts by mass of 4-hydroxyethyl acrylate (HEA), 0.18 parts by mass of acrylic acid (AA) in a 4-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler Parts by mass, 0.2 parts by mass of 2,2'-azobisisobutyronitrile and 150 parts by mass of ethyl acetate as a polymerization initiator, nitrogen gas was introduced while slowly stirring, and the liquid temperature in the flask was maintained at around 65° C. and polymerization for 6 hours The reaction was performed to prepare a (meth)acrylic polymer solution (40% by mass). The weight average molecular weight of the said acrylic polymer was 520,000, and the glass transition temperature (Tg) was -67 degreeC (refer the column of the adhesive composition 1 in Table 1).

<Preparation of adhesive composition 1>

The (meth)acrylic polymer solution (40 mass%) is diluted to 20 mass% with ethyl acetate, and trimethylolpropane/tolylenedi, which is an aromatic isocyanate compound as a crosslinking agent, is added to 500 mass parts (solid content 100 mass parts) of this solution. Isocyanate (manufactured by Nippon Polyurethane Industries, Ltd., trade name: Colonate L) 1 part by mass (solid content 1 part by mass), and an isocyanurate body of hexamethylene diisocyanate which is an aliphatic isocyanate-based compound (Japan Polyurethane Industries, Ltd., Colonate HX) ) 1 mass part (solid content 1 mass part), as a crosslinking catalyst, 3 mass parts (0.03 mass parts solid content) of dibutyltin dilaurate (1 mass % ethyl acetate solution) was added, mixed and stirred, and adhesive composition 1 (solution) was obtained prepared

<Preparation of aqueous solution for antistatic layer (back side treatment agent A)>

Polyester resin Vilonal MD-1480 (25% aqueous solution, manufactured by Toyobo) as a binder, polyaniline sulfonic acid (aquaPASS, weight average molecular weight 40,000, manufactured by Mitsubishi Rayon) as a conductive polymer, and diisopropylamine as a crosslinking agent As an isocyanurate form of hexamethylene diisocyanate, as a lubricant, oleic acid amide in a mixed solvent of water/ethanol (1/3), a binder in a solid content of 100 parts by mass, a conductive polymer in a solid content of 75 parts by mass, a crosslinking agent 10 parts by mass as a solid content and 30 parts by mass of a lubricant as a solid content were added, followed by stirring for about 20 minutes to sufficiently mix. In this way, an aqueous solution for an antistatic layer having an NV of about 0.4% was prepared.

<Preparation of aqueous solution for antistatic layer (back side treatment agent B)>

Polyester resin Vilonal MD-1480 (25% aqueous solution, manufactured by Toyobo) as a binder, polyaniline sulfonic acid (aquaPASS, weight average molecular weight 40,000, manufactured by Mitsubishi Rayon) as a conductive polymer, and diisopropylamine as a crosslinking agent An isocyanurate form of hexamethylene diisocyanate in a mixed solvent of water/ethanol (1/3), a binder in a solid content of 100 parts by mass, a conductive polymer in a solid content of 75 parts by mass, and a crosslinking agent in a solid content of 10 parts by mass. parts were added and stirred for about 20 minutes to sufficiently mix. In this way, an aqueous solution for an antistatic layer having an NV of about 0.4% was prepared.

<Preparation of aqueous solution for antistatic layer (back side treatment agent C)>

Polyester resin Vylonal MD-1480 (25% aqueous solution, manufactured by Toyobo Corporation) as a binder, poly(3,4-ethylenedioxythiophene) (PEDOT) 0.5% and polystyrene sulfonate (weight average molecular weight 150,000) as a conductive polymer ) (PSS) 0.8% aqueous solution (Bytron P, manufactured by HCStark), isocyanurate of hexamethylene diisocyanate blocked with diisopropylamine as a crosslinking agent, mixed with water/ethanol (1/1) To the solvent, 100 parts by mass of a binder, 50 parts by mass of a conductive polymer, and 10 parts by mass of a crosslinking agent in terms of solid content were added to the solvent, followed by stirring for about 20 minutes to sufficiently mix. In this way, an aqueous solution for an antistatic layer having an NV of about 0.4% was prepared.

<Preparation of aqueous solution for antistatic layer (back side treatment agent D)>

Polyester resin Vilonal MD-1480 (25% aqueous solution, Toyobo Co., Ltd.) as a binder and polyaniline sulfonic acid (aquaPASS, weight average molecular weight 40,000, Mitsubishi Rayon Co., Ltd.) as a conductive polymer were mixed with water/ethanol (1/3) as a binder. To the mixed solvent, 100 parts by mass of the binder and 75 parts by mass of the conductive polymer were added in terms of solid content, followed by stirring for about 20 minutes to sufficiently mix. In this way, an aqueous solution for an antistatic layer having an NV of about 0.4% was prepared.

<Preparation of a support film with an antistatic layer>

To a transparent polyethylene terephthalate (PET) film (polyester film) having a thickness of 38 µm, a width of 30 cm, and a length of 40 cm, corona-treated on one side (the first side), the antistatic layer (backside treatment agents A to D) Any aqueous solution of was applied so that the thickness after drying might be set to 30 nm. By heating and drying this coating material at 130 degreeC for 1 minute, the support film with an antistatic layer which has an antistatic layer in the 1st surface of PET film was produced.

<Example 1>

<Production of adhesive sheet>

The said adhesive composition 1 (solution) was apply|coated to the surface opposite to the antistatic layer of the said support film with an antistatic layer, it heated at 130 degreeC for 1 minute, and formed the 15-micrometer-thick adhesive layer. Next, the silicone-treated surface of a polyethylene terephthalate film (thickness of 25 µm), which is a separator that has been silicone-treated on one side, was bonded to the surface of the pressure-sensitive adhesive layer to prepare a pressure-sensitive adhesive sheet (surface protection film).

<Examples 2-17 and Comparative Examples 1-4>

Based on the compounding ratio of Table 1 and Table 2, it carried out similarly to Example 1, and produced the adhesive sheet. In addition, the compounding quantity in Table 1 showed solid content.

Measurement of initial adhesive force A in high-speed peeling of the prepared pressure-sensitive adhesive sheet according to the above evaluation method and adhesive force B over high temperature, adhesive force ratio (B/A), shear force, surface resistance value at initial stage and over time, slip property and printing adhesion were evaluated. The obtained results are shown in Table 3.

The abbreviation in Table 1 and Table 2 is demonstrated below.

2EHA: 2-ethylhexyl acrylate

BA: n-butyl acrylate

AA: acrylic acid (carboxyl group-containing (meth)acrylic monomer)

β-CEA: carboxylethyl acrylate (carboxyl group-containing (meth)acrylic monomer)

HEA: 2-hydroxyethyl acrylate (hydroxyl group-containing (meth)acrylic monomer)

HBA: 4-hydroxybutyl acrylate (hydroxyl group-containing (meth)acrylic monomer)

HEMA: hydroxyethyl methacrylate ((meth)acrylic monomer containing a hydroxyl group)

DEAA: N,N-diethylacrylamide

CL: Aromatic isocyanate-based compound, trimethylolpropane/tolylene diisocyanate (manufactured by Nippon Polyurethane Industries, trade name: Colonate L)

HX: an aliphatic isocyanate-based compound, an isocyanurate form of hexamethylene diisocyanate (manufactured by Japan Polyurethane, trade name: Colonate HX)

HL: aliphatic isocyanate compound, trimethylolpropane/hexamethylene diisocyanate adduct (manufactured by Nippon Polyurethane Industries, trade name: Colonate HL)

D110N: Aromatic isocyanate compound, trimethylolpropane/xylylene diisocyanate adduct (manufactured by Mitsui Chemicals, trade name: Takenate D-110N)

D140N: aliphatic isocyanate-based compound, takenate D-140N, trimethylolpropane/isophorone diisocyanate adduct (manufactured by Mitsui Chemicals, trade name: Takenate D-140N)

PEDOT: conductive polymer, poly(3,4-ethylenedioxythiophene)

PSS: conductive polymer, polystyrenesulfonate

Note) ">1E+13" in Table 3 indicates that the upper limit that can be measured with a resistivity meter is exceeded.

From the results of Table 3 above, in all Examples, the adhesive force ratio (B/A) was included in the desired range, and the adhesive force increased with the passage of time at high temperature with respect to the initial adhesive force at the time of high-speed peeling. This was suppressed and it was confirmed that the shear force was excellent.

On the other hand, in all the comparative examples, the adhesive force ratio (B/A) is out of the desired range, the initial adhesive force at the time of high-speed peeling is high, and the increase of the adhesive force with time at high temperature becomes large, and the adhesive force It was confirmed that it was inferior to the Example also in anti-rise property (adhesive force stability), re-peelability, workability, and shear force.

In addition, from the results of Table 3, as an antistatic layer, a desired raw material (conductive polymer component: polyanilinesulfonic acid, binder: polyester resin, and crosslinking agent: isocyanate-based crosslinking agent) was blended (antistatic agent composition) using a back treatment agent A prepared In the adhesive sheets of Examples 1, 5, 9-11, and 13-17 which have an antistatic layer, all evaluation items of the surface resistance resulting from an antistatic layer, slip property, and printing|printing adhesiveness were satisfied. On the other hand, with respect to the antistatic layer using the backing treatment agents B to D produced without mixing a part of the desired raw material, it was confirmed that none of the evaluation items of surface resistance, slip property and print adhesion attributed to the antistatic layer were satisfied. .

Claims (8)

In the pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition on one side of the support film, and an antistatic layer on one side of the support film on the opposite side to the pressure-sensitive adhesive layer,
The pressure-sensitive adhesive composition contains a (meth)acrylic polymer having a hydroxyl group and a carboxyl group, and a crosslinking agent,
The crosslinking agent contains an aromatic isocyanate-based compound and an aliphatic isocyanate-based compound,
With respect to the total amount of the monomer components constituting the (meth)acrylic polymer, 5.1 mass% or more of a hydroxyl group-containing (meth)acrylic monomer, and 0.01 mass% or more and less than 0.5 mass% of a carboxyl group-containing (meth)acrylic monomer, ,
The antistatic layer is formed of an antistatic agent composition containing polyanilinesulfonic acid as a conductive polymer component, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent,
The adhesive strength (A) at a peeling rate of 30 m/min after adhering the adhesive side of the pressure-sensitive adhesive layer to the TAC side at 23°C for 30 minutes, and the peeling rate after bonding the adhesive side of the pressure-sensitive adhesive layer to the TAC side at 70°C for 1 week An adhesive sheet, characterized in that the adhesive force ratio (B/A) of the adhesive force (B) at 30 m/min is less than 2. delete delete delete delete delete The adhesive sheet according to claim 1, wherein the antistatic agent composition further contains a fatty acid amide as a lubricant. It is protected by the adhesive sheet of Claim 1 or 7, The optical member characterized by the above-mentioned.