TWI708824B - Adhesive sheet, and optical component - Google Patents

Abstract

The present invention provides a method that can prevent the increase of adhesive force (adhesive force increase prevention property, adhesive force stability) over time at high temperature, can suppress the adhesive force during high-speed peeling to a low level, has excellent repeelability and workability, and cut Adhesive sheet with excellent cutting power.

The adhesive sheet of the present invention has an adhesive layer formed of an adhesive composition on one or both sides of the supporting film, and is characterized in that the adhesive surface of the adhesive layer is attached to the TAC surface at 23°C for 30 minutes Then the adhesive force (A) at the peeling speed of 30m/min, and the adhesive force (B) at the peeling speed of 30m/min after the adhesive surface of the above-mentioned adhesive layer is attached to the TAC surface at 70°C for 1 week The force ratio (B/A) is less than 2.

Description

Adhesive sheet, and optical component

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

The adhesive sheet of the present invention is useful as a surface protection film for protecting the surface of optical components such as polarizing plates, wave plates, retardation plates, optical compensation films, reflective sheets, and brightness enhancement films used in liquid crystal displays.

In recent years, when transporting optical components and electronic components or mounting them on a printed circuit board, the components are transported in a state in which each component is packaged with a specific sheet, or in a state where an adhesive tape is attached. Among them, surface protection films are particularly widely used in the fields of optics and electronic parts.

The surface protection film is usually attached to the adherend (protected body) through an adhesive applied on the supporting film side to prevent damage or dirt from processing and conveying the adherend (Patent Document 1) . For example, the panel of the liquid crystal display is formed by bonding an optical member such as a polarizing plate or a wave plate to a liquid crystal cell through an adhesive. These optical components are pasted with a surface protection film through an adhesive to prevent damage or dirt from being processed and transported.

In addition, when processing the adherend with the surface protective film attached, there are cases where high temperature treatment is performed. In this case, the adhesive force of the adhesive layer may increase significantly. Furthermore, when the surface protective film is peeled and removed at a stage where the surface protective film is not needed, the liquid crystal display panel, etc. whose work is an adherend, becomes larger or thinner, and it becomes easy to be in the peeling step. The polarizing plate or the liquid crystal cell as the adherend is damaged. Therefore, when peeling at high speed after high temperature treatment, light peeling is required.

For the surface protection film, in order to stick to the adherend (polarizing plate, etc.), The adhered body (polarizing plate, etc.) with the surface protective film does not produce unwanted curling or unintentional curling (the so-called curling refers to the phenomenon of warping, for example, the flat plate shape is warped integrally on either side The phenomenon that the flat shape warps in an overall undulating manner, etc.), and requires curl adjustment. If unnecessary curling or unintentional curling occurs, the operability will be poor. For example, there are cases where, when a polarizing plate or the like is attached to the liquid crystal cell, an abnormality such as mixing of bubbles may occur.

In addition, when the flat plate-shaped adherend is curled, The adhesive layer of the surface protection film of the adherend is accompanied by the force of the curl acting in the shear direction. Due to this force, the adherend and the adhesive layer will gradually slip or shift, etc., so low-speed peeling is required Increase in shear force.

[Patent Document 1] Japanese Patent Laid-Open No. 9-165460

Therefore, the purpose of the present invention is to eliminate the problems in the previous adhesive sheet, and provide a method that can prevent the increase of the adhesive force (adhesive force increase prevention property, adhesive force stability) over time at high temperature, and can prevent the adhesion during high-speed peeling. An adhesive sheet with low force suppression, excellent re-peelability and workability, and excellent shearing force.

That is, the adhesive sheet of the present invention has an adhesive layer formed of an adhesive composition on one or both sides of the support film, and is characterized in that the adhesive surface of the adhesive layer is attached to the TAC surface at 23°C Adhesive force (A) at a peeling speed of 30m/min after 30 minutes, and adhesive force (B) at a peeling speed of 30m/min after attaching the adhesive surface of the above adhesive layer to the TAC surface at 70°C for 1 week The adhesion ratio (B/A) is less than 2.

In the adhesive sheet of the present invention, it is preferable that the adhesive composition contains a (meth)acrylic polymer having a hydroxyl group and a carboxyl group.

In the adhesive sheet of the present invention, it is preferable that the adhesive composition contains a crosslinking agent, and the crosslinking agent contains an aromatic isocyanate compound and an aliphatic isocyanate compound.

The pressure-sensitive adhesive sheet of the present invention preferably contains a (meth)acrylic monomer containing a hydroxyl group at 5.1% by mass or more with respect to the total amount of monomer components constituting the (meth)acrylic polymer.

The adhesive sheet of the present invention preferably contains a carboxyl group-containing (meth)acrylic monomer of 0.01% by mass or more and less than 0.5% by mass relative to the total amount of monomer components constituting the (meth)acrylic polymer .

The adhesive sheet of the present invention preferably has an antistatic layer on one side of the support film on the side opposite to the adhesive layer, and the antistatic layer is made of polyaniline sulfonic acid as a conductive polymer component as an adhesive The polyester resin and the isocyanate crosslinking agent as the crosslinking agent are formed by the antistatic agent composition.

In the adhesive sheet of the present invention, it is preferable that the antistatic agent composition described above further contains a fatty amide as a lubricant.

The optical member of the present invention is preferably protected by the above-mentioned adhesive sheet.

The adhesive sheet of the present invention can prevent the increase in adhesive force over time at high temperature (adhesive force increase prevention property, adhesive force stability), can suppress the adhesive force during high-speed peeling to a low level, and has excellent repeelability and workability, Furthermore, the shearing force is excellent, and therefore, it is useful because it can suppress unwanted curling or unintentional curling of the adherend when it is attached to the adherend.

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

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

The adhesive sheet (surface protective film) of the present invention is generally called an adhesive sheet, an adhesive tape, an adhesive mark, an adhesive film, etc., especially for optical parts (for example, it can be used as a polarizing plate, a wave plate and other liquid crystal displays When processing or transporting (optical parts of the panel component), it is preferable as a surface protective film to protect the surface of the optical parts. The adhesive layer in the adhesive sheet is typically formed continuously, but it is not limited to the above-mentioned form. For example, the adhesive layer may be formed in a regular or irregular pattern such as dots and stripes. Moreover, the adhesive sheet disclosed here may be in a roll shape or a single sheet shape.

As a typical configuration example of the adhesive sheet (surface protection film) disclosed here, there can be mentioned: one having an adhesive layer on one or both sides of the support film (base material), or an antistatic device provided on one side of the support film The layer, and the adhesive layer provided on the surface of the supporting film opposite to the antistatic layer. The adhesive sheet attaches its adhesive layer to the adherend (protected object, such as partial It is used on the surface of optical parts such as light plates. The adhesive sheet before use (that is, before attaching to the adherend) can also be in the form of a release liner where the surface of the adhesive layer (attachment surface to the adherend) at least the side of the adhesive layer becomes the release surface protection. Or it can also be in the form of winding the adhesive sheet into a roll, whereby the adhesive layer abuts the back surface of the support film (the surface of the antistatic layer) and the surface of the adhesive layer is protected.

<Support film>

The adhesive sheet of the present invention is characterized by having an adhesive layer formed of an adhesive composition on one or both sides of the supporting film. The resin material constituting the above-mentioned support film can be used without particular limitation, but for example, it is preferable to use one having excellent properties such as transparency, mechanical strength, thermal stability, water resistance, isotropy, flexibility, and dimensional stability. In particular, since the support film has flexibility, the adhesive composition can be applied by a roll coater or the like, and it can be wound up in a roll shape, so it is useful.

As the above-mentioned supporting film (substrate), for example, polyterephthalene Polyester polymers such as ethylene formate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate; cellulose polymers such as diethyl cellulose and triacetyl cellulose Material; polycarbonate polymer; acrylic polymer such as polymethyl methacrylate as the main resin component (the main component of the resin component, typically, the component accounting for more than 50% by mass) resin material The formed plastic film serves as the above-mentioned supporting film. As other examples of the above-mentioned resin material, styrenic polymers such as polystyrene and acrylonitrile-styrene copolymer; polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, and ethylene- Olefin-based polymers such as propylene copolymers; vinyl chloride-based polymers; nylon 6, nylon 6,6, and amide-based polymers such as aromatic polyamides are used as resin materials. As still other examples of the above-mentioned resin materials, include: imine-based polymers, turbidity-based polymers, polyether turbidity-based polymers, polyether ether ketone-based polymers, polyphenylene sulfide-based polymers, ethylene Alcohol-based polymers, vinylidene chloride-based polymers, vinyl butyral-based polymers, aryl ester-based polymers, polyoxymethylene-based polymers, epoxy-based polymers, etc. It may also be a support film composed of a blend of two or more of the above-mentioned polymers.

As the above-mentioned supporting film, a transparent thermoplastic resin material can be preferably used. The composition of the plastic film. Among the above-mentioned plastic films, a polyester film is a more preferable aspect. Here, the so-called polyester film refers to polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, etc. having ester bonds as the basic The polymer material (polyester resin) of the main skeleton is set as the main resin component. The polyester film has optical characteristics and excellent dimensional stability, etc., which are preferable as a supporting film of an adhesive sheet. On the other hand, it has the property that static electricity is easily generated if it is kept as it is.

In the resin material constituting the above-mentioned supporting film, anti-oxidation can also be blended as needed Various additives such as agents, ultraviolet absorbers, plasticizers, colorants (pigments, dyes, etc.). For the first surface of the support film (the surface on the side where the antistatic layer is provided), for example, corona discharge treatment, plasma treatment, ultraviolet radiation treatment, acid treatment, alkali treatment, coating of primer, etc. Well-known or customary surface treatment. Such surface treatment may be, for example, a treatment for improving the adhesion between the support film and the antistatic layer. Surface treatments such as the introduction of polar groups such as hydroxyl groups (-OH groups) to the surface of the supporting film can be preferably used. In addition, the second surface of the support film (the surface on the side where the adhesive layer is formed) may be subjected to the same surface treatment as described above. The surface treatment can be a treatment for improving the adhesion between the film and the adhesive layer (fixing of the adhesive layer).

In addition, the adhesive sheet of the present invention may also have an antistatic layer on the supporting film, In the case of antistatic function, a plastic film made by antistatic treatment can also be used as the support film. By using the above supporting film, the static electricity of the adhesive sheet itself during peeling can be suppressed, Therefore it is better. In addition, by the support film being a plastic film and the antistatic treatment is applied to the plastic film, it is possible to reduce the static electricity of the adhesive sheet itself and to impart excellent antistatic ability to the adherend. Furthermore, there are no particular limitations on the method of imparting antistatic function, and previously known methods can be used. Examples include: coating an antistatic resin composed of an antistatic agent and a resin component or containing a conductive polymer, The method of conductive resin of conductive material, or the method of vapor deposition or plating of conductive material, the method of kneading antistatic agent, etc.

As the thickness of the support film, it is usually 5~200μm, preferably 10~ About 100μm. If the thickness of the support film is within the above range, the workability for attaching to the adherend and the workability for peeling from the adherend are excellent, which is preferable.

<Adhesive composition>

The adhesive sheet (surface protective film) of the present invention has the above-mentioned adhesive layer, and the above-mentioned adhesive layer is formed of an adhesive composition. As the above-mentioned adhesive composition, there is no particular limitation as long as it is adhesive. For use, for example, acrylic adhesives, urethane adhesives, synthetic rubber adhesives, natural rubber adhesives, silicone adhesives, etc. can also be used. Among them, more preferred is at least one selected from the group consisting of acrylic adhesives, urethane adhesives, and silicone adhesives. Particularly preferred is the use of acrylic adhesives. The acrylic adhesives Use (meth)acrylic polymer.

The adhesive composition used in the present invention preferably contains a (meth)acrylic polymer having a hydroxyl group and a carboxyl group. By using the (meth)acrylic polymer having a hydroxyl group and a carboxyl group, the hydroxyl group can easily control the crosslinking, and the carboxyl group can increase the shearing force or prevent the adhesion force from aging over time. Ascend, so it becomes a better state. In particular, the shear force of the adhesive (layer) is increased, and the adhesive can be attached to the The adhesive body suppresses the curling of the adhesive body, and prevents slippage or deviation between the adhesive and the adherend (interface), which is preferable. Furthermore, the term “(meth)acrylic polymer” in the present invention refers to acrylic polymer and/or methacrylic polymer, and “(meth)acrylate” refers to acrylate and/or Methacrylate.

In addition, the above-mentioned (meth)acrylic polymer uses the above-mentioned hydroxyl-containing (meth) Acrylic monomer as a monomer component makes it easy to control the crosslinking of the adhesive composition, and then it becomes easy to control the improvement of wettability by flow, the cohesion with the adhesive (layer), or the peeling The reduction of adhesion (light peeling) and the balance of shearing force. Furthermore, when an antistatic agent is added to the adhesive, unlike the carboxyl group or sulfonate group that usually functions as a crosslinking site, the hydroxyl group has a moderate interaction with the ionic compound as an antistatic agent, so In terms of antistatic properties, it can also be preferably used.

The adhesive sheet of the present invention preferably contains the (meth)acrylic acid The total amount of monomer components of the polymer is 5.1% by mass or more of the hydroxyl-containing (meth)acrylic monomer, more preferably 5.3-15% by mass, and still more preferably 7-12% by mass. If the content of the hydroxyl-containing (meth)acrylic monomer is within the above range, it becomes easier to control the balance between the wettability of the adhesive composition and the cohesive force or shear force of the adhesive (layer). Better.

As the above-mentioned hydroxyl-containing (meth)acrylic monomers, for example: (A Base) 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxy (meth)acrylate Octyl ester, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl acrylate, N-methylol (meth)acrylamide Wait.

The adhesive sheet of the present invention preferably contains the (meth)acrylic acid The total amount of monomer components of the polymer is 0.01% by mass or more and less than 0.5% by mass of the carboxyl group-containing (meth)acrylic monomer, more preferably 0.01 or more and less than 0.4% by mass, and more preferably 0.01 Above and less than 0.3% by mass, most preferably more than 0.01 and less than 0.2% by mass. If the content of the carboxyl group-containing (meth)acrylic monomer is within the above range, the increase in adhesive force over time can be suppressed, and re-peelability, prevention of increase in adhesive force, and workability are excellent. In addition, the adhesive layer has excellent cohesive force and shear force, which is preferable. Furthermore, if there are a large number of acid functional groups of the carboxyl group with greater polarity, there is a concern that when an ionic compound is blended as an antistatic agent, the acid functional group such as the carboxyl group interacts with the ionic compound Therefore, the ion conduction is hindered, and the conduction efficiency is reduced, and it becomes impossible to obtain sufficient antistatic property, so it is not good.

Examples of the above-mentioned 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)acryloxyethyl phthalic acid, 2-(meth)acryloxyethyl succinic acid, 2-(meth)acryloxy Ethyl maleic acid, carboxypolycaprolactone mono(meth)acrylate, 2-(meth)acryloyloxyethyltetrahydrophthalic acid, etc.

The adhesive composition used in the present invention contains the (meth)acrylic The acid-based polymer is not particularly limited as long as it is an adhesive (meth)acrylic polymer. It is preferable to use a (meth)acrylic monomer having a C1-C14 alkyl group as the monomer The main component of the ingredients is more preferably a (meth)acrylic monomer having an alkyl group with 4 to 14 carbon atoms. As the above-mentioned (meth)acrylic monomer, one type or two or more types can be used as a main component. Furthermore, the so-called "principal component" means the highest blending ratio.

As the above-mentioned (meth)acrylic monomer having a C1-C14 alkyl group Examples of methods include: methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, second butyl (meth)acrylate, and third butyl (meth)acrylate , Isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, (meth)acrylate Base) n-nonyl acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, (meth) N-tridecyl acrylate, n-tetradecyl (meth)acrylate, etc.

Among them, when using the adhesive sheet of the present invention as a surface protective film, Listed: 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, (Meth)acrylates having an alkyl group having 6 to 14 carbon atoms such as n-tetradecyl (meth)acrylate are preferable. By using a (meth)acrylate having an alkyl group with 6 to 14 carbon atoms, it becomes easy to control the adhesion to the adherend to be low, and it becomes a one with excellent removability.

The adhesive sheet of the present invention preferably contains the (meth)acrylic acid The total amount of monomer components of the polymer is 50 to 94.99% by mass of the above-mentioned (meth)acrylic monomer having a carbon number of 1 to 14 alkyl group, more preferably 60 to 94.9% by mass, and more preferably 70 ~94.8% by mass, most preferably 80-94.7% by mass. Since the content of the (meth)acrylic monomer having a carbon number of 1-14 is within the above range, the adhesive composition has moderate wettability and the cohesive force of the adhesive (layer) is also Excellent, therefore better.

In addition, as other polymerizable monomer components, it is easy to achieve a balance of adhesive performance For the reason, it can be used to make the Tg become 0°C or less within the range that does not impair the effect of the present invention. Adjust the glass transition temperature of the (meth)acrylic polymer, releasable polymerizable monomers, etc. in the following manner (usually above -100°C).

As the above-mentioned hydroxyl-containing compound used in the above-mentioned (meth)acrylic polymer Polymerizable monomers other than (meth)acrylic monomers, carboxyl group-containing (meth)acrylic monomers, and (meth)acrylic monomers having an alkyl group with 1 to 14 carbon atoms, as long as they are It can be used without any particular limitation within a range that does not impair the characteristics of the present invention. For example, the cohesive force and heat resistance improving components such as cyano group-containing monomers, vinyl ester monomers, aromatic vinyl monomers, etc.; or monomers containing amide groups, monomers containing imidine groups, and Amine group monomers, epoxy group-containing monomers, N-acrylomorpholine, vinyl ether monomers, and other components that improve adhesion (adhesion) or have functional groups that function as crosslinking points. These polymerizable monomers may be used alone or in combination of two or more kinds.

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

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

Examples of the aromatic vinyl monomers include styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene, and other substituted styrenes.

As the above-mentioned amine group-containing monomer, for example, acrylamide, methacrylamide, diethylacrylamide, N-vinylpyrrolidone, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylmethacrylamide, N,N-diethylmethacrylamide, N,N'-methylenebisacrylamide, N,N-dimethylaminopropyl acrylamide, N,N-dimethylaminopropylmethacrylamide, diacetone acrylamide, etc.

As the above-mentioned monomer containing an imine group, for example, cyclohexyl maleic acid Amine, isopropylmaleimide, N-cyclohexylmaleimide, itaconimine, etc.

As the above-mentioned amine group-containing monomer, for example, (meth)acrylic acid amino group ethyl Ester, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, etc.

As the above-mentioned epoxy group-containing monomer, for example, (meth)acrylic epoxy Propyl ester, methylglycidyl (meth)acrylate, allylglycidyl ether, etc.

Examples of the vinyl ether monomers include methyl vinyl ether and ethyl ethylene Ether, isobutyl vinyl ether, etc.

In the present invention, the above-mentioned (meth)acrylic monomers containing carboxyl groups and (meth)acrylic monomers containing hydroxyl groups (Base) acrylic monomers and other polymerizable monomers other than the (meth)acrylic monomers having an alkyl group with 1 to 14 carbon atoms in the total amount of monomer components constituting the (meth)acrylic polymer (Total monomer components) Preferably it is 0-40 mass %, More preferably, it is 0-30 mass %. By using the above-mentioned other polymerizable monomers in the above-mentioned range, it is possible to appropriately adjust the good interaction with the ionic compound that can be used as an antistatic agent and the good re-peelability.

The weight average molecular weight of the above (meth)acrylic polymer is 100,000 to 500 Million, preferably 200,000 to 4 million, and more preferably 300,000 to 3 million. When the weight average molecular weight is less than 100,000, there is a tendency for the paste to remain due to the reduced cohesive force of the obtained adhesive (layer). On the other hand, when the weight average molecular weight exceeds 5 million, there is a tendency that the fluidity of the polymer decreases and the wetting of the adherend (for example, a polarizing plate as an optical member) becomes insufficient. It becomes the cause of bulging between the adherend and the adhesive composition layer of the adhesive sheet. In addition, the weight average molecular weight means what is measured by GPC (gel permeation chromatography).

In addition, the glass transition temperature (Tg) of the (meth)acrylic polymer is preferably 0°C or lower, more preferably -10°C or lower, and still more preferably -20°C or lower (usually -100°C or higher). When the glass transition temperature is higher than 0°C, there is a tendency that the polymer is difficult to flow. For example, the wetting of the adherend (for example, the polarizing plate as an optical member) becomes insufficient and becomes adhered. The cause of the bulging between the body and the adhesive composition layer of the adhesive sheet. In particular, by setting the glass transition temperature to -61°C or lower, it becomes easy to obtain an adhesive composition with excellent wettability and light peelability to the adherend. Furthermore, the glass transition temperature of the (meth)acrylic polymer can be adjusted within the above-mentioned range by appropriately changing the monomer components or composition ratio used.

The polymerization method of the (meth)acrylic polymer used in the present invention is not particularly limited. The polymerization can be carried out by known methods such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, etc., especially in terms of workability. In terms of the viewpoint, or the characteristics of low pollution of the adherend, solution polymerization is a better aspect. In addition, the obtained polymer may be any of random copolymers, block copolymers, alternating copolymers, graft copolymers and the like.

Regarding the adhesive sheet of the present invention, the 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 with a low melting point (melting point 150°C or less). By containing this plasmonic compound, excellent antistatic properties can be imparted.

Moreover, the content of the ionic compound is preferably 1 part by mass or less with respect to 100 parts by mass of the (meth)acrylic polymer, more preferably 0.001 to 0.9 parts by mass, and still more preferably 0.005 to 0.8 parts by mass. If the content of the above-mentioned ionic compound is within the above-mentioned range, it is easy to achieve both antistatic properties and low pollution properties, which is preferable.

Regarding the adhesive sheet of the present invention, the adhesive composition may contain polyoxyethylene Organopolysiloxane of alkyl chain. It is estimated that by using the above-mentioned organopolysiloxane, the surface free energy on the surface of the adhesive is reduced, thereby achieving light peeling during high-speed peeling.

The above-mentioned organopolysiloxane can be appropriately used with well-known polyoxyalkylene chains. Organopolysiloxanes, for example, commercially available products include: trade names 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 Co., Ltd.); 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 Dow Corning Toray); IM22 (above) , Manufactured by Asahi Kasei Wacker Co., Ltd.); TSF-4440, TSF-4441, TSF-4445, TSF-4450, TSF-4446, TSF-4452, TSF-4460 (above, Momentive Advanced Materials); BYK-333, BYK -307, BYK-377, BYK-UV3500, BYK-UV3570 (above, manufactured by BYK Japan), etc. These can be used alone or in combination of two or more kinds.

As the aforementioned organopolysiloxane used in the present invention, HLB The value of (Hydrophile-Lipophile Balance) is preferably 1-16, more preferably 3-14. If the HLB value is out of the above range, the pollution to the adherend will become worse, so it is not good.

In addition, with respect to 100 parts by mass of the (meth)acrylic polymer, the above has 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 parts by mass. If the content of the aforementioned organopolysiloxane is within the aforementioned range, it is easy to achieve both antistatic properties and light releasability (removability), which is preferable.

In the adhesive sheet of the present invention, it is preferable that the adhesive composition contains a crosslinking agent. The crosslinking agent preferably contains an aromatic isocyanate-based compound and an aliphatic isocyanate-based compound (in some cases, it is called an isocyanate-based compound or an isocyanate-based crosslinking agent by combining two isocyanate-based compounds). Furthermore, the above-mentioned cross-linking agent is cross-linked by appropriately adjusting the selection and addition ratio of the cross-linking agent according to the structural unit or composition ratio of the above-mentioned (meth)acrylic polymer, etc., thereby achieving better heat resistance. The adhesive sheet (adhesive layer). In particular, when the crosslinking agent contains an aromatic isocyanate compound and an aliphatic isocyanate compound, it is possible to prevent the increase of the adhesive force over time (adhesive force increase prevention property), which is useful.

In addition, as the crosslinking agent used in the present invention, in addition to containing the above-mentioned aromatic isocyanic acid In addition to ester-based compounds and aliphatic isocyanate-based compounds, epoxy compounds, melamine-based resins, aziridine derivatives, metal chelate compounds, and the like can also be suitably used. Moreover, these crosslinking agents may be used individually by 1 type, and may mix and use 2 or more types.

二

三酮鍵等而改質上述異氰酸酯系化合物(異氰酸酯系交聯劑)而成之聚異氰酸酯改質體。 Examples of the aliphatic isocyanate compound include: aliphatic polyisocyanates such as trimethylene diisocyanate, butene diisocyanate, hexamethylene diisocyanate (HDI), and dimer acid diisocyanate; cyclopentylene diisocyanate; Alicyclic isocyanates such as isocyanate, cyclohexyl diisocyanate, isophorone diisocyanate (IPDI), etc. Moreover, as said aromatic isocyanate type compound, aromatic isocyanates, such as 2, 4- toluene diisocyanate, 4,4'- diphenylmethane diisocyanate, xylylene diisocyanate (XDI), etc. are mentioned. Furthermore, examples include: allophanate bonds, biuret bonds, isocyanurate bonds, uretdione bonds, urea bonds, carbodiimide bonds, uretonimine bonds,

two

A modified polyisocyanate obtained by modifying the above-mentioned isocyanate compound (isocyanate crosslinking agent) with a triketone bond or the like.

For example, as the above isocyanate compound (isocyanate crosslinking agent) Commercially available products include: Trade names Takenate 300S, Takenate 500, Takenate D110N, Takenate D140N, Takenate D165N, Takenate D178N (above, manufactured by Mitsui Chemicals Co., Ltd.), Sumidur T80, Sumidur L, Desmodur N3400 (above, manufactured by Sumika Bayer Urethane Co., Ltd.), MILLIONATE MR, MILLIONATE MT, Coronate L, Coronate HL, Coronate HX (above , Japan Nippon Polyurethane Industry Co., Ltd.) and so on. These isocyanate compounds may be used in combination of two or more types, or a bifunctional isocyanate compound and a trifunctional or more isocyanate compound may be used in combination. By using a cross-linking agent in combination, an adhesive sheet that prevents the increase in adhesive force over time or has excellent shear force can be obtained.

As the above-mentioned epoxy compound, for example, N,N,N',N'-tetraepoxypropyl Metaxylylenediamine (commodity TETRAD-X, manufactured by Mitsubishi Gas Chemical Company) or 1,3-bis(N,N-diglycidylaminomethyl) cyclohexane (trade name TETRAD-C, Mitsubishi Gas Chemical Company) Chemical company manufacturing) etc.

As said melamine resin, hexamethylol melamine etc. are mentioned. As an aziridine derivative, the brand name HDU, TAZM, TAZO (above, manufactured by Huto Pharmaceutical Co., Ltd.) etc. which are a commercial item are mentioned, for example.

Examples of the above-mentioned metal chelate compound include: aluminum, iron, Tin, titanium, nickel, etc., acetylene, methyl acetyl acetate, ethyl lactate, etc. as chelate components.

Regarding the content of the crosslinking agent used in the present invention, for example, relative to the above (methyl) 100 parts by mass of the acrylic polymer, preferably 0.01-10 parts by mass, more preferably 0.1-8 parts by mass, still more preferably 0.5-5 parts by mass, most preferably 1.0-4 parts by mass. In the case where the above content is less than 0.01 parts by mass, the cross-linking formation by the cross-linking agent may become insufficient, and the cohesive force of the adhesive composition may decrease, and sufficient heat resistance may not be obtained. The tendency to become the cause of paste residue. On the other hand, when the content exceeds 10 parts by mass, There is a tendency that the cohesive force of the polymer is large, the fluidity is reduced, and the wetting of the adherend (for example, the polarizing plate) becomes insufficient, and the adherend and the adhesive layer (adhesive composition) The cause of the bulging between layers). Furthermore, if the amount of crosslinking is large, the peeling electrostatic characteristics tend to decrease. In addition, these crosslinking agents may be used alone or in combination of two or more kinds.

Also, as the above-mentioned aromatic isocyanate compound and aliphatic isocyanate The blending ratio of the compound is not particularly limited, for example (aromatic isocyanate compound/aliphatic isocyanate compound) (mass ratio) is preferably 3/1~1/50, more preferably 2/1~1/ 40, more preferably 1/1 to 1/30. If it is the above blending ratio, it can prevent the increase of the adhesive force with time, so it is useful.

The above-mentioned adhesive composition may further contain a cross-linking catalyst in order to advance any of the above-mentioned cross-linking reactions more effectively. As the crosslinking catalyst, for example, tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate, tris(acetone) iron, and tris(hexane-2,4-dioic acid) iron can be used. , Tris(heptane-2,4-dioic acid) iron, tris(heptane-3,5-dioic acid) iron, tris(5-methylhexane-2,4-dioic acid) iron, tris(octane Alkane-2,4-dioic acid) iron, tris(6-methylheptane-2,4-dioic acid) iron, tris(2,6-dimethylheptane-3,5-dioic acid) iron, Tris(nonane-2,4-dioic acid) iron, tris(nonane-4,6-dioic acid) iron, tris(2,2,6,6-tetramethylheptane-3,5-dioic acid) ) Iron, tris(tridecane-6,8-dioic acid) iron, tris(1-phenylbutane-1,3-dioic acid) iron, tris(hexafluoroacetone) iron, tris(acetone) Ethyl acetate) iron, tris(acetate-n-propyl) iron, tris(acetate isopropyl) iron, tris(acetate-n-butyl) iron, tris(acetate-n-butyl) iron Base) iron, tris(acetate-tertiary butyl) iron, tris(acrylic acid methyl) iron, tris(acrylic acid ethyl) iron, tris(acrylic acid-n-propyl) iron, three (Acrylic acid isopropyl) iron, tris(acrylic acid-n-butyl) iron, tris(acrylic acid-second butyl) iron, tris(acrylic acid-tertiary butyl) iron, tris( (Benzyl acetylacetate) iron, tris(dimethyl malonate) iron, tris(diethyl malonate) iron, trimethoxy iron, triethoxy iron, triisopropoxy iron, trichloro Iron-based catalysts such as FeCl ₃ . One type of these crosslinking catalysts may be used, or two or more types may be used in combination.

The content (usage amount) of the above-mentioned crosslinking catalyst is not particularly limited, for example, relative to 100 parts by mass of the (meth)acrylic polymer is preferably about 0.0001 to 1 part by mass, more preferably 0.001 to 0.5 part by mass. If the content of the above-mentioned cross-linking catalyst is within the above-mentioned range, the speed of the cross-linking reaction is faster when the adhesive layer is formed, and the pot life of the adhesive composition becomes longer, which becomes a preferable aspect.

In the adhesive composition of the present invention, it may also contain no organopolysiloxane The compound containing polyoxyalkylene chain. By containing the above-mentioned compound in the adhesive composition, an adhesive composition with more excellent wettability to the adherend can be obtained.

As one of the above-mentioned polyoxyalkylene chain compounds not containing organopolysiloxane Specific examples include, for example, polyoxyalkylene alkylamine, polyoxyalkylene diamine, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene Nonionic surfactants such as alkyl phenyl ether, polyoxyalkylene alkyl ether, polyoxyalkylene alkyl allyl ether, polyoxyalkylene alkyl phenyl allyl ether; polyoxyalkylene alkyl Anionic interfacial activity such as alkyl ether sulfate, polyoxyalkylene alkyl ether phosphate, polyoxyalkylene alkyl phenyl ether sulfate, polyoxyalkylene alkyl phenyl ether phosphate salt, etc. In addition to the above, cationic surfactants or zwitterionic surfactants with polyoxyalkylene chains (polyalkylene oxide chains), polyether compounds with polyoxyalkylene chains (and their derivatives Compounds), polyester compounds with polyoxyalkylene chains (and their derivatives), acrylic compounds with polyoxyalkylene chains (and their derivatives), etc. In addition, the polyoxyalkylene chain-containing monomer may be blended into the acrylic polymer as a polyoxyalkylene chain-containing compound. The polyoxyalkylene chain-containing compound may be used alone or in combination of two or more kinds.

As specific examples of the above polyketone compound having a polyoxyalkylene chain, there can be listed Examples include: polypropylene glycol (PPG)-polyethylene glycol (PEG) block copolymer, PPG-PEG-PPG block copolymer, PEG-PPG-PEG block copolymer, etc. Examples of derivatives of the above-mentioned polyether compound having a polyoxyalkylene chain include: oxypropylene-containing compounds (PPG monoalkyl ether, PEG-PPG monoalkyl ether, etc.) whose ends are etherified, and terminal Acetylated oxypropylene-containing compounds (terminally acetylated PPG, etc.), etc.

In addition, as a specific example of the acrylic compound having a polyoxyalkylene chain Examples include (meth)acrylate polymers having oxyalkylene groups. As the above-mentioned oxyalkylene group, from the viewpoint of coordination of an ionic compound, the number of added moles of the oxyalkylene group unit is preferably 1-50, more preferably 2-30, and still more preferably 2~ 20. In addition, the terminal of the above-mentioned oxyalkylene group may be directly a hydroxyl group, or may be substituted with an alkyl group, a phenyl group, or the like.

The above-mentioned (meth)acrylate polymer having an oxyalkylene group preferably contains (formaldehyde (Meth)acrylic acid alkylene oxide as a polymer of the monomer unit (component), as a specific example of the above-mentioned (meth)acrylic acid alkylene oxide, ethylene glycol group-containing (meth)acrylate can be cited, for example: Methoxy-polyethylene glycol (meth)acrylate type such as methoxy-diethylene glycol (meth)acrylate, methoxy-triethylene glycol (meth)acrylate, ethoxy- Diethylene glycol (meth)acrylate, ethoxy-triethylene glycol (meth)acrylate and other ethoxy-polyethylene glycol (meth)acrylate type, butoxy-diethylene glycol (Meth)acrylate, butoxy-triethylene glycol (meth)acrylate, butoxy-polyethylene glycol (meth)acrylate type, phenoxy-diethylene glycol (meth) Phenoxy-polyethylene glycol (meth)acrylate type such as acrylate, phenoxy-triethylene glycol (meth)acrylate, 2-ethylhexyl-polyethylene glycol (meth)acrylate , Nonylphenol-polyethylene glycol (meth)acrylate type, methoxy-polypropylene glycol (meth)acrylate type such as methoxy-dipropylene glycol (meth)acrylate, etc.

In addition, monomer units other than the above (meth)acrylate alkylene oxide can be used (Component) as the above-mentioned monomer unit (component). Specific examples of other monomer units include: methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, second butyl (meth)acrylate, (meth) ) Tert-butyl acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, (meth)acrylic acid Isooctyl ester, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate Acrylate and/or methacrylate having an alkyl group with 1 to 14 carbon atoms, such as ester, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, etc.

啉、乙烯醚類等。 Furthermore, as monomer units (components) other than the above-mentioned (meth)acrylic acid alkylene oxide, carboxyl group-containing (meth)acrylate, phosphoric acid group-containing (meth)acrylate, and cyano group-containing (Meth)acrylates, vinyl esters, aromatic vinyl compounds, (meth)acrylates containing acid anhydride groups, (meth)acrylates containing hydroxyl groups, (meth)acrylates containing amide groups , Amino-containing (meth)acrylate, epoxy-containing (meth)acrylate, N-acrylic acid

Morpholine, vinyl ethers, etc.

As a preferred aspect, the above-mentioned polyoxyethylene-containing polyoxyethylene that does not contain organopolysiloxane The base chain compound is a compound having at least a part of (poly)ethylene oxide chain. By blending the above-mentioned compound with (poly)ethylene oxide chain, the compatibility between the base polymer and the antistatic component is improved, and the exudation to the adherend is preferably suppressed, and a low-polluting adhesive composition is obtained Things. Among them, especially when a block copolymer of PPG-PEG-PPG is used, an adhesive composition with excellent low pollution properties can be obtained. As the above-mentioned polyethylene oxide chain-containing compound, the mass of the (poly)ethylene oxide chain in the entire compound is preferably 5 to 90% by mass, more preferably 5 to 85% by mass, and still more preferably 5 to 80% by mass, preferably 5 to 75% by mass.

As one of the above-mentioned polyoxyalkylene chain compounds not containing organopolysiloxane The molecular weight is preferably those having a number average molecular weight (Mn) of 50,000 or less, more preferably 200 to 30,000, further preferably 200 to 10,000, and particularly preferably 200 to 5,000. If the Mn is too larger than 50,000, the compatibility with the acrylic polymer decreases and the adhesive layer tends to become white. If Mn is too less than 200, contamination by the above-mentioned polyoxyalkylene compound is likely to occur. In addition, Mn here means the value obtained by GPC (gel permeation chromatography) in terms of polystyrene.

Also, regarding the above-mentioned polyoxyalkylene-containing chain without containing organopolysiloxane Specific examples of commercially available products of the compound include, for example, Adeka Pluronic 17R-4, Adeka Pluronic 25R-2 (all the above are manufactured by ADEKA), Emulgen 120 (manufactured by Kao), and the like.

As one of the above-mentioned polyoxyalkylene chain compounds not containing organopolysiloxane The blending amount, relative to 100 parts by mass of the above-mentioned (meth)acrylic polymer, can be, for example, 0.005 to 20 parts by mass, preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and most preferably 0.1~1 parts by mass. If the blending amount is too small, the effect of preventing the antistatic component from oozing out is reduced, and if the blending amount is too large, the pollution caused by the above-mentioned polyoxyalkylene compound may easily occur.

Furthermore, an acrylate oligomer may be contained in the said adhesive composition. The acrylate oligomer preferably has a weight average molecular weight of 1,000 or more and less than 30,000, more preferably 1,500 or more and less than 20,000, and still more preferably 2,000 or more and less than 10,000. When used in the acrylic adhesive composition for re-peeling of this embodiment, it functions as an adhesive imparting resin to improve the adhesion (adhesion) and is effective in suppressing the swelling of the adhesive sheet

(Meth)acrylate monomers can be used for the above-mentioned acrylate oligomer, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and (meth)acrylic acid can be used. Isopropyl ester, butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, Tertiary butyl (meth)acrylate, pentyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylate Base) heptyl acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, (meth)acrylate Base) isodecyl acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate and other alkyl (meth)acrylates; phenyl (meth)acrylate, (meth)acrylate (Meth)acrylate such as benzyl acrylate; (meth)acrylate obtained from terpene compound derivative alcohol.

In addition, the above-mentioned acrylate oligomer can use (meth)acrylic monomers having an alicyclic structure, for example, dicyclopentyl methacrylate, dicyclopentyl acrylate, and dicyclopentyloxyethyl methacrylate. , Dicyclopentyloxyethyl acrylate, tricyclopentyl methacrylate, tricyclopentyl acrylate, 1-adamantyl methacrylate, 1-adamantyl acrylate, 2-methyl-2 methacrylate -Adamantyl ester, 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl acrylate, etc. (methyl ) Acrylic etc. Such (meth)acrylic monomers can be used alone or in combination of two or more kinds.

In addition, the above-mentioned acrylate oligomer has a single component of the (meth)acrylic monomer It can also be obtained by copolymerizing other monomer components (copolymerizable monomers) copolymerizable with the above-mentioned (meth)acrylic monomer.

The weight average molecular weight of the above-mentioned acrylate oligomer is above 1000 and does not reach 30,000, preferably 1,500 or more and less than 20,000, more preferably 2,000 or more and less than 10,000. If the weight average molecular weight is 30,000 or more, the adhesiveness (adhesion) decreases. In addition, if the weight average molecular weight is less than 1,000, it becomes a low molecular weight, which causes a decrease in the adhesive force of the adhesive sheet.

Furthermore, in the above-mentioned adhesive composition, it may contain a keto-enol intermutation Structural compounds act as crosslinking retarders. For example, the following aspect can be preferably adopted: the adhesive composition containing the crosslinking agent or the adhesive composition obtained by blending the crosslinking agent contains the above-mentioned compound that produces keto-enol tautomerism. Thereby, the excessive viscosity increase or gelation of the adhesive composition after blending the crosslinking agent can be suppressed, and the effect of extending the pot life of the adhesive composition can be achieved. In the case where at least an isocyanate compound is used as the above-mentioned crosslinking agent, it is particularly meaningful to contain a compound that produces keto-enol tautomerism. This technique can be preferably applied to the case where the above-mentioned adhesive composition is in an organic solvent solution or solvent-free form, for example.

As the above-mentioned compound that produces keto-enol tautomerism, various β- Dicarbonyl compounds. Specific examples include: acetone, 2,4-hexanedione, 3,5-heptanedione, 2-methylhexane-3,5-dione, 6-methylheptane- 2,4-Diketone, 2,6-Dimethylheptane-3,5-dione and other β-diketones; methyl acetyl acetate, ethyl acetyl acetate, isopropyl acetyl acetate, ethyl acetate Acetyl acetates such as tertiary butyl acetate; Acetyl acetates such as ethyl acrylate, ethyl acrylate, isopropyl propyl acetate, tert-butyl propyl acetate, etc.; isobutyl acetic acid Isobutyl acetates such as ethyl ester, ethyl isobutyl acetate, isopropyl isobutyl acetate, tertiary butyl isobutyl acetate; malonic esters such as methyl malonate and ethyl malonate Class; etc. Among them, preferred compounds include acetone and acetone acetate. The keto-enol tautomerism-producing compound may be used alone or in combination of two or more kinds.

Regarding the content of the compound that produces keto-enol tautomerism, relative to 100 parts by mass of the (meth)acrylic polymer can be set to, for example, 0.1 to 20 parts by mass, and usually 0.5 to 15 parts by mass (for example, 1 to 10 parts by mass) is appropriately set. If the amount of the above-mentioned compound is too small, it may become difficult to exert a sufficient use effect. On the other hand, if the above-mentioned compound is used in a large amount more than necessary, it may remain in the adhesive layer and the cohesive force may decrease.

Furthermore, the adhesive composition used in the adhesive sheet of the present invention may also contain There are other well-known additives, such as powders such as colorants, pigments, surfactants, plasticizers, adhesion-imparting agents, low-molecular-weight polymers, surface lubricants, leveling agents, and antioxidants, depending on the application. , Preservatives, light stabilizers, ultraviolet absorbers, polymerization inhibitors, silane coupling agents, inorganic or organic fillers, metal powders, particles, foils, etc.

The adhesive sheet of the present invention is characterized by: on one side or both sides of the supporting film There is an adhesive layer formed of the above-mentioned adhesive composition (formed by cross-linking the adhesive composition), but in this case, the cross-linking of the adhesive composition is usually carried out after the application of the adhesive composition, but it can also Transfer the adhesive layer composed of the cross-linked adhesive composition to the support film, etc. In addition, the method of forming the adhesive layer on the support film is not particularly limited. For example, the adhesive layer is formed on the support film by coating the adhesive composition on the support film, and drying and removing the polymerization solvent. Manufactured from above. After that, it may be matured for the purpose of adjusting the component transfer of the adhesive layer or adjusting the crosslinking reaction. In addition, when the adhesive composition is applied to the support film to produce an adhesive sheet, in order to be uniformly coated on the support film, one or more solvents other than the polymerization solvent may be newly added to the adhesive composition .

Also, as a method of forming the adhesive layer when manufacturing the adhesive sheet of the present invention, Use the well-known method used in the manufacture of adhesive sheets. Specifically, for example, roll coating, gravure coating, reverse coating, roll brush coating, spray coating, air knife coating method, extrusion coating method using die nozzle coater, etc. are mentioned.

The adhesive sheet of the present invention is usually preferably that the thickness of the adhesive layer is 3-100 μm, more preferably, it is produced so that the thickness becomes about 5-50 μm. If the thickness of the adhesive layer is within the above range, it is easy to achieve a proper balance between re-peelability and adhesion (adhesion). Therefore it is better.

<divider>

For the adhesive sheet (surface protection film) of the present invention, a separator for protecting the adhesive surface can be attached to the surface of the adhesive layer as needed.

There are paper or plastic film as the material of the above-mentioned separator, but the surface is smooth In terms of excellent performance, a plastic film can be preferably used. The film is not particularly limited as long as it can protect the above-mentioned adhesive layer, and examples include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, Polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, etc.

The thickness of the above partition is usually 5~200μm, preferably 10~100μm about. If the thickness is within the above range, the workability for attaching the adhesive layer and the peeling workability for the self-adhesive layer are excellent, which is preferable. For the above-mentioned separators, mold release treatment and antifouling treatment using silicone, fluorine, long-chain alkyl, or fatty amide based mold release agents, silica powder, etc. can also be performed as needed , Or coating type, kneading type, vapor deposition type and other antistatic treatment.

The adhesive sheet of the present invention is provided on one side or both sides of the supporting film with an adhesive group The adhesive layer formed by the finished product, and the adhesive surface of the above-mentioned adhesive layer is attached to the TAC surface at 23°C for 30 minutes, and the adhesive force (A) at a peeling speed of 30m/min, and the above-mentioned adhesive layer at 70°C The adhesive force ratio (B/A) of the adhesive force (B) at a peeling speed of 30m/min after being attached to the TAC surface for 1 week after the adhesive layer of the adhesive layer is less than 2, preferably 0.5~1.9, more preferably 0.7~1.8. With the above-mentioned adhesive force ratio (B/A) in the above-mentioned range, even when the It has excellent resistance to force rise (adhesive strength stability), and excellent re-peelability and workability, making it a preferred aspect.

In addition, as the adhesive surface of the above-mentioned adhesive layer at 23°C, stick it on the TAC surface 30 The adhesive force (A) at a peeling speed of 30m/min after minutes is preferably 2.0N/25mm or less, more preferably 0.1~1.9N/25mm, and even more preferably 0.1~1.8N/25mm. If the above-mentioned adhesive force (A) exceeds 2.0N/25mm, it will be difficult to peel the adhesive sheet (surface protective film) from the adherend, and the peeling workability when the adhesive sheet is not required is poor, and the adherend may be damaged due to the peeling step Wait, so it is not good.

As the adhesive surface of the above-mentioned adhesive layer attached to the TAC surface at 70°C for 1 week The adhesion force (B) at a peeling speed of 30m/min is preferably less than 4.0N/25mm, more preferably 0.1~3.5N/25mm, and still more preferably 0.1~3.0N/25mm. If the above-mentioned adhesive force (B) is 4.0N/25mm or more, it will be difficult to peel off the adhesive sheet (surface protective film) from the adherend, and the peeling workability when the adhesive sheet is not required is poor, and the peeling step will cause the adherend Damage and so on, so it is not good.

In addition, the adhesive sheet of the present invention is to apply the adhesive surface of the adhesive layer at 23°C Adhesion (A) at a peeling speed of 30m/min after being attached to the TAC surface for 30 minutes, and at 70℃ for 1 week at a peeling speed of 30m/min after attaching the adhesive layer of the above adhesive layer to the TAC surface The adhesion ratio (B/A) of the force (B) is less than 2, preferably 0.5 to 1.9, and more preferably 0.7 to 1.8. Since the above-mentioned adhesive force ratio (B/A) is in the above-mentioned range, the re-peelability and workability are excellent, which is a preferable aspect.

Furthermore, regarding the adhesive sheet of the present invention, when the adhesive area of the adhesive layer is 1cm ² attached to a TAC polarizing plate, and after attaching it at 23°C for 30 minutes, it is peeled in the shearing direction at a peeling speed of 0.06mm/min. The shear force is preferably 10 N/cm ² or more, more preferably 10 to 50 N/cm ² , and still more preferably 10 to 40 N/cm ² . If the above-mentioned shearing force is within the above-mentioned range, the force in the shearing direction generated when the adherend is curled can be withstood without slippage or deviation of the adhesive sheet, and the curling of the adherend can be suppressed. Better.

<Antistatic layer (surface coating)>

The adhesive sheet of the present invention preferably has an antistatic layer on one side of the support film on the side opposite to the adhesive layer, and the antistatic layer is made of polyaniline sulfonic acid as a conductive polymer component as an adhesive The polyester resin and the isocyanate crosslinking agent as the crosslinking agent are formed by the antistatic agent composition. Since the above-mentioned adhesive sheet has an antistatic layer (top coat), the antistatic property of the adhesive sheet is improved, which becomes a preferred aspect.

<Conductive polymer>

The antistatic layer preferably contains polyaniline sulfonic acid as a conductive polymer component. By using the above conductive polymer, the antistatic property based on the antistatic layer can be satisfied. In addition, the above-mentioned polyaniline sulfonic acid is "water-soluble", but by using the following isocyanate-based crosslinking agent, it can be fixed in the antistatic layer and the water resistance can be improved. By using the above-mentioned water-soluble conductive polymer-containing aqueous solution, an antistatic layer with excellent surface resistance over time can be obtained, which becomes a preferred aspect. On the other hand, when the conductive polymer used to form the antistatic layer is "water-dispersible", if the water-dispersible conductive polymer-containing solution is used to form the antistatic layer, it may become It is easy to produce agglomerates and cannot be applied uniformly, so the surface resistance value tends to deteriorate significantly over time, so it is not good.

Regarding the usage of the above conductive polymer, relative to the antistatic layer (top coat) 100 parts by mass of the binder contained, preferably 10 to 200 parts by mass, more preferably 25 to 150 parts by mass Parts, more preferably 40 to 120 parts by mass. If the amount of the conductive polymer used is too small, the antistatic effect may be reduced. If the amount of the conductive polymer used is too large, the adhesion of the antistatic layer to the support film may decrease, or the transparency may decrease , So it is not good.

The polyaniline sulfonic 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, and more preferably 3×10 ⁵ or less. In addition, the weight average molecular weight of these conductive polymers is generally preferably 1×10 ³ or more, more preferably 5×10 ³ or more.

As a method of forming the above-mentioned antistatic layer, a coating material (antistatic agent composition) for forming the antistatic layer can be applied to the first surface of the support film, and dried (or hardened) as the coating The conductive polymer component used in the preparation of the material preferably contains polyaniline sulfonic acid, a polyester resin as a binder, and an isocyanate-based crosslinking agent as a crosslinking agent, and the above-mentioned essential components can be preferably used Those dissolved in water (referred to as conductive polymer aqueous solution, or simply as aqueous solution). The above-mentioned conductive polymer aqueous solution can be carried out, for example, by dissolving a conductive polymer having a hydrophilic functional group (which can be synthesized by a method such as copolymerization of a monomer having a hydrophilic functional group in the molecule) in water. preparation. Examples of the above hydrophilic functional groups include sulfo groups, amino groups, amide groups, imino groups, hydroxyl groups, sulfhydryl groups, hydrazine groups, carboxyl groups, quaternary ammonium groups, sulfate groups (-O-SO ₃ H), phosphoric acid Ester group (for example -O-PO(OH) ₂ ) and the like. The above-mentioned hydrophilic functional group may also form a salt.

In addition, as a commercial product of the above-mentioned polyaniline sulfonic acid aqueous solution, Mitsubishi Rayon The company’s product name "aquaPASS", etc.

As the conductive polymer component of the antistatic layer disclosed here, it contains polystyrene Aminosulfonic acid (polyaniline type) is an essential component, but for example, it can also contain one or two other types at the same time The above antistatic components (organic conductive materials other than conductive polymers, inorganic conductive materials, antistatic agents, etc.). Furthermore, as a preferred aspect, the antistatic layer does not substantially contain antistatic components other than the conductive polymer, that is, the antistatic component contained in the antistatic layer can be more preferably implemented. It is made of conductive polymer.

Examples of the above-mentioned organic conductive materials include: quaternary ammonium salts, onium salts, Cationic antistatic agents with cationic functional groups such as primary amino groups, secondary amino groups, and tertiary amino groups; anionic antistatic agents with anionic functional groups such as sulfonate or sulfate ester salt, phosphonate, and phosphate ester salt Electrostatic agent; Alkyl betaine and its derivatives, imidazoline and its derivatives, alanine and its derivatives and other zwitterionic antistatic agents; amino alcohol and its derivatives, glycerin and its derivatives, polyethylene Non-ionic antistatic agents such as alcohols and their derivatives; obtained by polymerizing or copolymerizing monomers with the above-mentioned cationic, anionic, and zwitterionic ion conductive groups (for example, quaternary ammonium salt groups) Ion conductive polymers; conductive polymers such as polythiophene, polyaniline, polypyrrole, polyethyleneimine, and allylamine-based polymers. Such antistatic agents may be used individually by 1 type, and may be used in combination of 2 or more types.

Examples of the above-mentioned inorganic conductive materials 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, copper iodide, ITO (indium oxide/tin oxide), ATO (antimony oxide/tin oxide), etc. Such an inorganic conductive substance may be used individually by 1 type, and may be used in combination of 2 or more types.

Examples of the antistatic agent include: cationic antistatic agents, anionic antistatic agents, zwitterionic antistatic agents, nonionic antistatic agents, and ionic conductivity of the above-mentioned cationic, anionic, and zwitterionic types. Ion conductive polymer etc. obtained by polymerizing and copolymerizing monomers of a reactive group.

<Adhesive>

The antistatic layer preferably contains a polyester resin as a binder. The above-mentioned polyester resin is preferably a resin material containing polyester as a main component (typically, more than 50% by mass, preferably more than 75% by mass, for example, a component that accounts for more than 90% by mass). Regarding the above-mentioned polyester, it is typically preferable to have a polycarboxylic acid selected from the group having two or more carboxyl groups in one molecule (typically, a dicarboxylic acid) and derivatives thereof (anhydrous of the polycarboxylic acid, One or two or more compounds (polycarboxylic acid components) among ester compounds, halides, etc.), and polyols (typically, glycols) having two or more hydroxyl groups in one molecule A structure formed by condensation of one or more compounds (polyol components).

Examples of compounds that can be used as the above-mentioned polycarboxylic acid components include: Oxalic acid, malonic acid, difluoromalonic acid, alkylmalonic acid, succinic acid, tetrafluorosuccinic acid, alkylsuccinic acid, (±)-malic acid, meso-tartaric acid, itaconic acid, maleic acid, Methyl maleic acid, fumaric acid, methyl fumaric acid, acetylene dicarboxylic acid, glutaric acid, hexafluoroglutaric acid, methyl glutaric acid, glutaconic acid, adipic acid, dithiohexanedi Acid, methyl adipic acid, dimethyl adipic acid, tetramethyl adipic acid, methylene adipic acid, muconic acid, galactonic acid, pimelic acid, suberic acid, perfluoroocteric acid Acid, 3,3,6,6-tetramethyl suberic acid, azelaic acid, sebacic acid, perfluorosebacic acid, tridecanedioic acid, dodecyl dicarboxylic acid, tridecane dicarboxylic acid Aliphatic dicarboxylic acids such as carboxylic acid and tetradecyl dicarboxylic acid; cycloalkyl dicarboxylic acid (for example, 1,4-cyclohexane dicarboxylic acid, 1,2-cyclohexane dicarboxylic acid), 1 , 4-(2-Norbornene) dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid (bicycloheptene dicarboxylic acid, himic acid), adamantane dicarboxylic acid, spiroheptane dicarboxylic acid Alicyclic dicarboxylic acids; phthalic acid, isophthalic acid, disulfide isophthalic acid, methyl isophthalic acid, dimethyl isophthalic acid, chloro isophthalic acid, dichloro isophthalic acid Dicarboxylic acid, terephthalic acid, methyl terephthalic acid, dimethyl terephthalic acid, chloroterephthalic acid, bromine Phthalic acid, naphthalenedicarboxylic acid, pendant oxadicarboxylic acid, anthracene dicarboxylic acid, biphenyl dicarboxylic acid, biphenyl dicarboxylic acid, dimethyl biphenyl dicarboxylic acid, 4,4" -P-tetraphenyl dicarboxylic acid (4,4"-p-terephenylenel dicarboxylic acid), 4,4"-p-quaterphenyl dicarboxylic acid (4,4"-p-quaterphenyl dicarboxylic acid), Benzyl dicarboxylic acid, azobenzene dicarboxylic acid, subphthalic acid, phenylene diacetic acid, phenylene dipropionic acid, naphthalene dicarboxylic acid, naphthalenedipropionic acid, biphenyl diacetic acid, biphenyl dipropionic acid , 3,3'-[4,4'-(methylenebis-p-biphenyl)]dipropionic acid, 4,4'-bibenzyldiacetic acid, 3,3'(4,4'- Aromatic dicarboxylic acids such as bibenzyl)dipropionic acid and oxydi-p-phenylene diacetic acid; anhydrides of any of the above polycarboxylic acids; esters of any of the above polycarboxylic acids (for example, alkyl esters) , Monoester, diester, etc.); corresponding to any of the above-mentioned polycarboxylic acid halides (for example, dicarboxylic acid chloride (dicarboxylic acid chloride)); etc.

Regarding preferred examples of compounds that can be used as the above-mentioned polycarboxylic acid components, Examples: terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid and other aromatic dicarboxylic acids and their anhydrides; adipic acid, sebacic acid, azelaic acid, succinic acid, fumaric acid, maleic acid, bicyclic Aliphatic dicarboxylic acids such as heptene dicarboxylic acid and 1,4-cyclohexane dicarboxylic acid and their anhydrides; and lower alkyl esters of the above-mentioned dicarboxylic acids (for example, esters with monoalcohols with 1 to 3 carbon atoms) )Wait.

On the other hand, regarding examples of compounds that can be used as the aforementioned polyol component, Examples include ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 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 and other glycols. As another example, an alkylene oxide adduct of these compounds (for example, an ethylene oxide adduct, a propylene oxide adduct, etc.) can be mentioned.

Regarding the molecular weight of the above-mentioned polyester resin, in terms of the weight average molecular weight (Mw) converted from standard polystyrene measured by gel permeation chromatography (GPC), it can be, for example, 5×10 ³ to 1.5×10 ⁵ About (preferably about 1×10 ⁴ to 6×10 ⁴ ). In addition, the glass transition temperature (Tg) of the polyester resin can be, for example, 0 to 120°C (preferably 10 to 80°C).

As the above polyester resin, commercially available products manufactured by Toyobo Corporation can be used Name "VYLONAL MD-1480" and so on.

The above antistatic layer (top coat) will not greatly damage the adhesion disclosed here The sheet (surface protective film) can also contain resins other than polyester resins (for example, selected from acrylic resins, acrylic-urethane resins, acrylic-styrene resins) within the range of performance (for example, antistatic properties) , Acrylic-polysiloxane resin, polysiloxane resin, polysilazane resin, polyurethane resin, fluororesin, polyolefin resin, etc. (one or two or more resins) as adhesives. As a preferred aspect of the technology disclosed here, the adhesive of the antistatic layer is substantially composed of only polyester resin. For example, an antistatic layer with a polyester resin accounting for 98 to 100% by mass of the adhesive is preferable. The ratio of the binder in the entire antistatic layer can be set to, for example, 50 to 95% by mass, and usually is appropriately set to 60 to 90% by mass.

<Lubricant>

The aforementioned antistatic layer (top coat) preferably uses fatty amide as a lubricant. By using aliphatic amide as a lubricant, even if the surface of the antistatic layer is not further peeled off (for example, coating a known peeling agent such as a polysiloxane-based peeling agent, a long-chain alkyl-based peeling agent, etc.) In the state of drying treatment), an antistatic layer (top coat) that has both sufficient sliding properties and printing adhesion can also be obtained, so it can be a better state. Regarding the state without further peeling treatment on the surface of the antistatic layer as described above, it is possible to prevent the whitening caused by the peeling treatment agent (for example, the whitening caused by storage under heating and humidifying conditions) before it occurs. In other words, better. In addition, it is also advantageous in terms of solvent resistance.

As specific examples of the above fatty amide, lauryl amide, palmitamide, Stearylamine, behenylamine, hydroxystearylamine, oleamide, erucamide, N-oleyl hexadecylamine, N-stearyl stearylamine, N-hard Fatty oleamide, N-oleyl stearyl amine, N-stearyl mustard amide, hydroxymethyl stearyl amide, methylene bis-stearyl amide, ethylene bisdecyl amide, Ethylene bis-lauric amide, ethylene bis-stearyl amide, ethylene bis-hydroxystearyl amide, ethylene bis-behenamide, hexamethylene bis-stearyl amide, hexamethylene Dibehenamide, hexamethylene hydroxystearyl amide, N,N'-distearyl hexadiamide, N,N'-distearyl sebacamide, ethylene bis-oleamide Amine, ethylenebiseramide, hexamethylenebisoleylamide, N,N'-dioleyl hexamethylenediamide, N,N'-dioleyl sebacamide, m-phenylene Methyl bis-stearyl amide, meta-xylylene dimethyl bis-hydroxystearyl amide, N,N'-stearyl meta-xylylene dimethyl amide, etc. These lubricants may be used alone or in combination of two or more kinds.

The proportion of the lubricant in the whole antistatic layer can be set to 1-50% by mass. It is often appropriately set to 5-40% by mass. If the content ratio of the lubricant is too small, the sliding properties tend to be easily reduced. If the lubricant content is too high, the printing adhesion may decrease.

The technology disclosed here can be The antistatic layer (top coat) is implemented in the form of not only containing the above fatty amide, but also other lubricants. Examples of the above-mentioned other lubricants include: petroleum waxes (paraffin wax, etc.), mineral waxes (montan wax, etc.), higher fatty acids (cerotic acid, etc.), neutral fats (palmitic acid triglyceride) Etc.) various waxes. Alternatively, in addition to the above waxes, usual silicone lubricants, fluorine lubricants, etc. may be additionally contained. The technology disclosed here can preferably be implemented in a state that does not substantially contain the aforementioned silicone-based lubricant, fluorine-based lubricant, etc. Among them, Yu will not be larger To the extent that the application effect of the technology disclosed here is impaired, it is not excluded to contain polysiloxanes used for different purposes from lubricants (for example, as a defoaming agent for the coating material for forming the antistatic layer described below) Compound.

<Crosslinking agent>

The antistatic layer preferably contains an isocyanate-based crosslinking agent as a crosslinking agent. By using the above-mentioned isocyanate-based crosslinking agent, the water-soluble polyaniline sulfonic acid, which is an essential component when forming the antistatic layer, is fixed in the adhesive, thereby achieving excellent water resistance and improving printing adhesion.

Blocked isocyanate-based crosslinking agent that is also stable in aqueous solution The case of the isocyanate-based crosslinking agent is a preferred aspect. As specific examples of the above-mentioned blocked isocyanate-based crosslinking agent, use can be made of alcohols, phenols, thiophenols, amines, imines, oximes, endoamines, and active methylene compounds. Types, mercaptans, imines, ureas, diaryl compounds, and sodium bisulfite, etc. will usually be used in the preparation of the adhesive layer or antistatic layer (top coat) isocyanate-based crosslinking agent (such as , The isocyanate compound (isocyanate-based crosslinking agent) used in the adhesive layer is blocked.

The antistatic layer in the technology disclosed here may contain antistatic materials as needed. Points, antioxidants, colorants (pigments, dyes, etc.), fluidity regulators (thixotropic agents, tackifiers, etc.), film-forming aids, surfactants (defoamers, etc.), preservatives and other additives.

<Formation of Antistatic Layer>

The above-mentioned antistatic layer (top coat layer) can be preferably formed by the following method, which includes: dissolving the above-mentioned conductive polymer components and other essential components and optional additives in a suitable solvent (water, etc.) To form a liquid composition (coating material for forming an antistatic layer), and support The film imparts the liquid composition. For example, the following method can be preferably used: the above-mentioned coating material is coated on the first surface of the support film and dried, and if necessary, a hardening treatment (heat treatment, ultraviolet treatment, etc.) is performed. The NV (non-volatile content) of the coating material can be set to, for example, 5 mass% or less (typically, 0.05 to 5 mass%), and usually appropriately set to 1 mass% or less (typically, 0.10 to 1 mass %). In the case of forming an antistatic layer with a small thickness, it is preferable to set the NV of the coating material to, for example, 0.05 to 0.50 mass% (for example, 0.10 to 0.40 mass%). By using a low NV coating material as described above, a more uniform antistatic layer can be formed.

烷等環狀醚類；正己烷、環己烷等脂肪族或脂環族烴類；甲苯、二甲苯等芳香族烴類；甲醇、乙醇、正丙醇、異丙醇、環己醇等脂肪族或脂環族醇類；伸烷基二醇單烷基醚(例如，乙二醇單甲醚、乙二醇單乙醚)、二伸烷基二醇單烷基醚等二醇醚類等中之1種或2種以上。於較佳之一態樣中，上述塗佈材之溶劑為水或以水為主成分之混合溶劑(例如，水與乙醇之混合溶劑)。 The solvent constituting the coating material for forming the antistatic layer is preferably one that stabilizes and dissolves the forming components of the antistatic layer. The solvent can be an organic solvent, water, or a mixed solvent thereof. As the above-mentioned organic solvent, for example, esters selected from ethyl acetate; ketones such as methyl ethyl ketone, acetone, and cyclohexanone; tetrahydrofuran (THF), two

Cyclic ethers such as alkanes; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; aliphatic such as methanol, ethanol, n-propanol, isopropanol, and cyclohexanol Dialkylene glycol monoalkyl ether (for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether), dialkylene glycol monoalkyl ether and other glycol ethers, etc. One or more of them. In a preferred aspect, the solvent of the coating material is water or a mixed solvent mainly composed of water (for example, a mixed solvent of water and ethanol).

<Properties of Antistatic Layer>

Regarding the thickness of the aforementioned antistatic layer, typically, it is 3 to 500 nm, preferably 3 to 100 nm, and more preferably 3 to 60 nm. If 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 unevenness of the thickness depending on the location becomes large), and therefore, it may become easy to be applied to the adhesive sheet ( Surface protection film) has uneven appearance. On the other hand, if the thickness is too thick, it may affect the characteristics of the support film (optical characteristics, dimensional stability, etc.) shape.

In a preferred aspect of the adhesive sheet (surface protective film) disclosed here, the surface resistance value (Ω/□) measured on the surface of the antistatic layer is preferably less than 1.0×10 ¹¹ , It is more preferably less than 5.0×10 ¹⁰ , and still more preferably less than 2.0×10 ¹⁰ . The adhesive sheet showing the surface resistance value within the above-mentioned range can be preferably used as an adhesive sheet used in the processing or conveying process of articles that avoid static electricity such as liquid crystal cells or semiconductor devices, for example. Furthermore, the above-mentioned surface resistance value can be calculated from the surface resistance value measured under an environment of 23°C and 50%RH using a commercially available insulation resistance measuring device.

The adhesive sheet (surface protective film) disclosed here preferably has the following properties: That is, the back side (the surface of the antistatic layer) can be easily printed with water-based ink or oil-based ink (for example, using an oil-based marker). The adhesive sheet is suitable for processing or conveying the adherend (for example, optical parts) in the state where the adhesive sheet is attached, and the identification number of the adherend as the object of protection is recorded in the above adhesive sheet And display it. Therefore, it is preferably an adhesive sheet with excellent printability. For example, it is preferable that the solvent is an alcohol-based oil-based ink containing a pigment type, and has a higher printability. In addition, it is preferable that it is difficult to remove the ink of the printed characters by wiping or transferring (that is, the printing adhesiveness is excellent). Regarding the adhesive sheet disclosed here, it is also preferable to have solvent resistance to the extent that when the printing is corrected or erased, even if the printing is wiped with alcohol (for example, ethanol), the appearance will not change significantly.

The adhesive sheet (surface protective film) disclosed here can also contain a support film (base In addition to the material), the adhesive layer, and the antistatic layer, it also contains other layers. Examples of the arrangement of the above-mentioned "other layers" include arrangement between the first surface (back surface) of the support film and the antistatic layer, and arrangement between the second surface (front surface) of the support film and the adhesive layer. Configured to support The layer between the front surface of the film and the adhesive layer may be, for example, an undercoat layer (anchoring layer), an antistatic layer, etc., which improves the adhesion of the adhesive layer to the second surface. It can also be an adhesive sheet composed of an antistatic layer arranged on the front surface of the support film, an anchor layer arranged on the antistatic layer, and an adhesive layer arranged on the antistatic layer.

The optical member of the present invention is preferably protected by the above-mentioned adhesive sheet. Above adhesive sheet It can prevent the adhesive force from increasing over time (under high temperature), and the adhesive force during high-speed peeling is low, and the re-peelability and workability are excellent. Therefore, it can be used for surface protection purposes such as processing, transportation, and shipping. To protect the surface of the above-mentioned optical components (polarizing plates, etc.). In addition, the above-mentioned adhesive sheet has excellent shearing force, and therefore, curling of the adherend (optical member) to which the above-mentioned adhesive sheet is bonded can be suppressed, and the workability is excellent, so it is useful.

[Example]

Hereinafter, examples and the like concretely showing the structure and effects of the present invention will be described, but the present invention is not limited to these. In addition, the content of blending and the evaluation of characteristics in the examples and the like were measured in the following manner. In addition, Table 1 shows the physical properties of the (meth)acrylic polymer used in the adhesive composition, or the blending ratio of the adhesive composition, and Table 2 shows the blending content of the antistatic layer. Table 3 shows the evaluation results of the characteristics.

<evaluation>

The specific measurement and evaluation methods are described below.

<Measurement of weight average molecular weight (Mw)>

The weight average molecular weight (Mw) was measured using a GPC device (HLC-8220GPC) manufactured by Tosoh Co., Ltd. The measurement conditions are as follows.

Sample concentration: 0.2% by mass (THF solution)

Sample injection volume: 10μl

Eluent: THF

Flow rate: 0.6ml/min

Measuring temperature: 40℃

Column: sample column; TSKguardcolumn Super HZ-H (1) + TSKgel SuperHZM-H (2)

Reference column; TSKgel SuperH-RC (1 piece)

Detector: Differential Refractometer (RI)

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

<Theoretical value of glass transition temperature>

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

Formula: 1/(Tg+273)=Σ[Wn/(Tgn+273)]

[In the formula, Tg(℃) represents the glass transition temperature of the copolymer, Wn(-) represents the mass fraction of each monomer, Tgn(℃) represents the glass transition temperature of the homopolymer of each monomer, and n represents each monomer Types of Body].

Literature value: 2-ethylhexyl acrylate (2EHA): -70°C

Butyl acrylate (BA): -55℃

Acrylic acid (AA): 106°C

Carboxyethyl acrylate (β-CEA): 37℃

2-Hydroxyethyl acrylate (HEA): -15℃

4-hydroxybutyl acrylate (HBA): -32℃

Hydroxyethyl methacrylate (HEMA): 55℃

N,N-Diethylacrylamide (DEAA): 81℃

In addition, as literature values, refer to "Synthesis of Acrylic Resin. Design and New Application Development" (published by the Central Management Development Center Publishing Department) and "Polymer Handbook" (John Wiley & Sons).

<Measurement of initial adhesion (A)>

After placing the TAC polarizing plate (manufactured by Nitto Denko, SEG1423DU polarizing plate, width: 70mm, length: 100mm) at 23℃×50%RH for 24 hours, cut into an adhesive sheet with a width of 25mm and a length of 100mm to 0.25 The pressure of MPa and the speed of 0.3 m/min were laminated on the above-mentioned adherend to prepare an evaluation sample.

After the above lamination, put it in an environment of 23℃×50%RH for 30 minutes. Use a universal tensile tester to measure the initial adhesion (A) (N/25mm) when peeling at a peeling speed of 30m/min (high-speed peeling) and a peeling angle of 180°. The measurement is performed under an environment of 23°C×50%RH.

Furthermore, the above-mentioned adhesive force (A) is preferably 2.0N/25mm or less, more preferably 0.1~1.9N/25mm, more preferably 0.1~1.8N/25mm. If the above-mentioned adhesive force (A) exceeds 2.0N/25mm, it becomes difficult to peel the adhesive sheet (surface protective film) from the adherend, and the peeling workability is poor when the adhesive sheet is not required, and the peeling step causes the adhesion to the adherend The body causes damage, etc., so it is not good.

<Measurement of Adhesion (B) with Time at High Temperature>

After placing the TAC polarizing plate (manufactured by Nitto Denko, SEG1423DU polarizing plate, width: 70mm, length: 100mm) at 23℃×50%RH for 24 hours, cut into an adhesive sheet with a width of 25mm and a length of 100mm to 0.25 The pressure of MPa and the speed of 0.3 m/min were laminated on the above-mentioned adherend to prepare an evaluation sample.

After the above-mentioned lamination, leave it at 70℃ for 1 week (7 days), The universal tensile tester measures the time-dependent adhesion (B) (N/25mm) when peeling off at a peeling speed of 30m/min (high-speed peeling) and a peeling angle of 180°. The measurement is performed under an environment of 23°C×50%RH.

Furthermore, the above-mentioned adhesive force (B) is preferably less than 4.0N/25mm, more preferably 0.1~3.5N/25mm, more preferably 0.1~3.0N/25mm. If the above-mentioned adhesive force (B) is 4.0N/25mm or more, it becomes difficult to peel off the adhesive sheet (surface protective film) from the adherend, and the peeling workability is poor when the adhesive sheet is not required, and the peeling step causes the peeling Adhesives cause damage, etc., so it is not good.

<Evaluation of Adhesion Ratio (B/A)>

The adhesive force (A) and the adhesive force ratio (B/A) of the adhesive force (B) are less than 2, preferably 0.5 to 1.9, and more preferably 0.7 to 1.8. Since the above-mentioned adhesive force ratio (B/A) is in the above-mentioned range, the re-peelability and workability are excellent, which is a preferable aspect. Furthermore, the above-mentioned adhesive force ratio is evaluated as an index of the prevention of the increase in adhesive force over time at high temperature.

<Measurement of Shear Force>

The adhesive sheet was cut into a size of 10mm in width and 100mm in length, and after the separator was peeled off, it was pasted on a TAC polarizer (manufactured by Nitto Denko Co., Ltd.) so that the area of the adhesive layer of the above-mentioned adhesive sheet becomes 1cm ² . SEG1423DU polarizing plate, width: 25mm, length: 100 mm), after standing for 30 minutes at room temperature (23℃×50%RH), it is stretched along the shearing direction at a peeling speed of 0.06mm/min. The maximum load (N/cm ² ) is the shear force.

Furthermore, the above-mentioned shear force (N/cm ² ) is preferably 10 or more, more preferably 10-50, and still more preferably 10-40. If the above-mentioned shearing force is within the above-mentioned range, the force in the shearing direction generated when the adherend is curled can be withstood without slippage or deviation of the adhesive sheet, and the curling of the adherend can be suppressed. Better.

<Measurement of surface resistance>

In an environment with a temperature of 23° C. and a humidity of 50% RH, a resistivity meter (Mitsubishi Chemical ANALYTECH, Hiresta UP MCP-HT450) was used to measure in accordance with JIS-K-6911.

Furthermore, as the surface resistance value (Ω/□) of the surface of the antistatic layer in the present invention, the initial and static room temperature (23℃×50%RH)×1 week (7 days) conditions are more It is preferably less than 1.0×10 ¹¹ , more preferably less than 5.0×10 ¹⁰ , and still more preferably less than 2.0×10 ¹⁰ . An adhesive sheet (surface protective film) showing a surface resistance value within the above range can be preferably used as an adhesive sheet used in the processing or transportation of items that are not static, such as liquid crystal cells or semiconductor devices.

<Measurement of Sliding (Dynamic Friction)>

The adhesive sheet (surface protection film) is cut into a size of 70mm in width and 100mm in length, and is prepared by attaching it to an acrylic plate (manufactured by Mitsubishi Rayon, trade name "ACRYLITE", thickness: 1mm, width: 70mm, length: 100mm) Audition. Place the back of the test piece (antistatic layer surface) facing down and place it on a smooth PET film that is kept horizontal, and place a load of 1.5 kg on the test piece. Use a non-stretchable wire, install the test piece with the above load on the tensile testing machine, Set the temperature at 25°C, stretch the test piece horizontally under the conditions of a stretching speed of 300mm/min and a stretching distance of 300mm, and obtain the average value of the dynamic friction force (N) applied to the test piece (n=3).

Furthermore, as the sliding property (dynamic frictional force) (N) in the present invention, it is preferably 5 or less, more preferably 4.5 or less, and still more preferably 4 or less. If the dynamic friction force is within the above range, when the adherend to which the adhesive sheet is attached is handled, the back surface of the support film (antistatic layer surface) has good sliding properties, which is advantageous in terms of workability.

<Evaluation of printability (printing adhesion)>

Under the measuring environment of 23℃×50%RH, use X stamper manufactured by Shachihata Company to print on the surface of the antistatic layer, and paste Sellotape (registered trademark) manufactured by Miqibang Company from the top of the printing. Then, Peel off under the conditions of peeling speed of 30m/min and peeling angle of 180°. After that, the peeled surface was visually observed, and the case where more than 50% of the printed area was peeled off was evaluated as × (bad printability), and the case where more than 50% of the printed area was not peeled off and remained was evaluated as ○ (printability good).

<Preparation method>

Specific preparation methods of (meth)acrylic polymer or adhesive composition are described below.

<Preparation of (meth)acrylic polymer>

Add 94.5 parts by mass of 2-ethylhexyl acrylate (2EHA), 5.32 parts by mass of 4-hydroxyethyl acrylate (HEA), and acrylic acid (AA) to a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube, and a cooler. 0.18 parts by mass, 0.2 parts by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 150 parts by mass of ethyl acetate. While stirring slowly, nitrogen is introduced to maintain the liquid temperature in the flask at Around 65°C, the polymerization reaction is carried out for 6 hours to prepare (meth)acrylic Polymer solution (40% by mass). The weight average molecular weight of the acrylic polymer is 520,000, and the glass transition temperature (Tg) is -67°C (refer to the column of adhesive composition 1 in Table 1).

<Preparation of Adhesive Composition 1>

The above-mentioned (meth)acrylic polymer solution (40% by mass) was diluted to 20% by mass with ethyl acetate, and 500 parts by mass of the solution (100 parts by mass of solid content) was added as a crosslinking agent of aromatic isocyanate The compound, namely trimethylolpropane/toluene diisocyanate (manufactured by Nippon Polyurethane Industry, trade name: Coronaate L) 1 part by mass (solid content 1 part by mass), and hexamethylene diisocyanate as an aliphatic isocyanate compound Isocyanurate body of isocyanate (manufactured by Nippon Polyurethane Industry, Coronaate HX) 1 part by mass (solid content 1 part by mass), dibutyltin dilaurate (1% by mass ethyl acetate solution) as a crosslinking catalyst 3 parts by mass (0.03 parts by mass of the solid content) were mixed and stirred to prepare an adhesive composition 1 (solution).

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

The polyester resin VYLONAL MD-1480 (25% aqueous solution, manufactured by Toyobo) as a binder, polyaniline sulfonic acid (aquaPASS, a weight average of 40,000, manufactured by Mitsubishi Rayon) as a conductive polymer, Diisopropylamine-terminated isocyanurate body of hexamethylene diisocyanate as a crosslinking agent, a mixed solvent of oleamide and water/ethanol (1/3) as a lubricant for bonding The agent is 100 parts by mass based on the solid content, the conductive polymer is 75 parts by mass based on the solid content, the crosslinking agent is 10 parts by mass based on the solid content, and the lubricant is based on the solid content. It is carried out in 30 parts by mass, stirring for about 20 minutes to fully mix. In the above manner, an aqueous solution for the antistatic layer with an NV of about 0.4% was prepared.

<Preparation of Aqueous Solution for Antistatic Layer (Back Surface Treatment Agent B)>

The polyester resin VYLONAL 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, are used as the adhesive The mixed solvent of the isocyanurate body of hexamethylene diisocyanate blocked by diisopropylamine and water/ethanol (1/3) of the coupling agent, and the solid content of the binder is 100 mass The conductive polymer is added so that the solid content is 75 parts by mass, and the crosslinking agent is 10 parts by mass in terms of the solid content, and it is stirred for about 20 minutes to fully mix. In the above manner, an aqueous solution for the antistatic layer with an NV of about 0.4% was prepared.

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

The polyester resin VYLONAL MD-1480 (25% aqueous solution, manufactured by Toyobo) as a binder, a conductive polymer containing 0.5% of poly(3,4-ethylenedioxythiophene) (PEDOT) and polystyrene Ethylene sulfonate (weight average molecular weight 150,000) (PSS) 0.8% aqueous solution (Bytron P, manufactured by HCStark), diisopropylamine-terminated hexamethylene diisocyanate as a crosslinking agent Mixed solvent of cyanurate body and water/ethanol (1/1), 100 parts by mass based on the solid content of the binder, 50 parts by mass based on the solid content of the conductive polymer, crosslinking agent It is added so that the solid content is 10 parts by mass, and it is stirred for about 20 minutes to fully mix. In the above manner, an aqueous solution for the antistatic layer with an NV of about 0.4% was prepared.

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

Combine polyester resin VYLONAL 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 water/ The mixed solvent of ethanol (1/3) is added so that the binder is 100 parts by mass based on the solid content and the conductive polymer is 75 parts by mass based on the solid content. Stir for about 20 minutes to fully mix . In the above way, about 0.4% of NV is prepared Aqueous solution for antistatic layer.

<Production of supporting film with antistatic layer>

Coat any one of the above-mentioned antistatic layers (back treatment agents A to D) with an aqueous solution such that the thickness after drying becomes 30nm on one side (the first surface) with a thickness of 38μm, a width of 30cm, and a length of 40cm. On the transparent polyethylene terephthalate (PET) film (polyester film). The coating was heated at 130° C. for 1 minute and dried to produce a support film with an antistatic layer having an antistatic layer on the first surface of the PET film.

<Example 1> <Making of Adhesive Sheet>

The adhesive composition 1 (solution) was coated on the opposite side of the antistatic layer of the support film with the antistatic layer, and heated at 130°C for 1 minute to form an adhesive layer with a thickness of 15 μm. Then, on the surface of the above-mentioned adhesive layer, a separator that has been treated with silicone on one side, that is, the silicone treated surface of a polyethylene terephthalate film (thickness 25μm), is attached to make an adhesive sheet ( Surface protection film).

<Examples 2 to 17, and Comparative Examples 1 to 4>

Based on the blending ratios in Table 1, and Table 2, an adhesive sheet was produced in the same manner as in Example 1. In addition, the blending amount in Table 1 indicates the solid content.

According to the above-mentioned evaluation method, the initial adhesion force A and the high-temperature adhesion strength B of the produced adhesive sheet during high-speed peeling, the adhesion force ratio (B/A), the shearing force, the initial stage and the elapsed time were measured Evaluation of surface resistance, sliding properties, and printing adhesion. The results obtained are shown in Table 3.

In the following, the abbreviations in Table 1 and Table 2 are described.

2EHA: 2-ethylhexyl acrylate

BA: n-butyl acrylate

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

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

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

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

HEMA: Hydroxyethyl methacrylate ((meth)acrylic monomer containing hydroxyl)

DEAA: N,N-diethyl acrylamide

CL: Aromatic isocyanate compound, trimethylolpropane/toluene diisocyanate (manufactured by Nippon Polyurethane Industry, trade name: Coronate L)

HX: Aliphatic isocyanate compound, isocyanurate body of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry, trade name: Coronaate HX)

HL: Aliphatic isocyanate compound, trimethylolpropane/hexamethylene diisocyanate adduct (manufactured by Nippon Polyurethane Industry, trade name: Coronate HL)

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

D140N: Aliphatic isocyanate 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, polystyrene sulfonate

From the results in Table 3 above, it can be confirmed in all the examples that the adhesive force ratio (B/A) is included in the required range, and the adhesive force at the initial stage of high-speed peeling can be suppressed. The adhesive force is increased, and the shear force is excellent.

In contrast, it was confirmed that in all the comparative examples, the adhesive force ratio (B/A) deviated from the required range, and the initial adhesive force during high-speed peeling was higher, and the increase in the adhesive force over time under high temperature changed It is large, and the adhesion strength increase prevention property (adhesive strength stability), re-peelability, workability, and shear strength are also inferior to the Examples.

In addition, from the results in Table 3 above, it was confirmed that there are raw materials required for the use of blending (conductive polymer component: polyaniline sulfonic acid, binder: polyester resin, and crosslinking agent: isocyanate-based crosslinking agent) (resistant The adhesive sheet of Examples 1, 5, 9~11 and 13~17 in which the antistatic layer of the back surface treatment agent A manufactured as the antistatic layer meets: the surface resistance and sliding properties of the antistatic layer And all evaluation items for the adhesion of printing. On the other hand, it was confirmed that the antistatic layer of the back surface treatment agents B~D manufactured without blending a part of the required raw materials did not satisfy all the evaluation items of the surface resistance, sliding property and printing adhesion due to the antistatic layer .

Claims (4)

An adhesive sheet having an adhesive layer formed by an adhesive composition on one side of a supporting film, and an antistatic layer on one side of the supporting film on the opposite side of the adhesive layer, and its characteristics It consists of: sticking the adhesive surface of the adhesive layer to the TAC surface at 23°C for 30 minutes, and the adhesive force (A) at a peeling speed of 30m/min, and sticking the adhesive surface of the adhesive layer to the TAC surface at 70°C The adhesive force ratio (B/A) of the adhesive force (B) at the peeling speed of 30m/min after one week from the TAC surface is less than 2. The adhesive composition contains (meth)acrylic polymer and crosslinking agent , Containing 5.1% by mass or more of hydroxyl-containing (meth)acrylic monomers, and 0.01% by mass or more and less than 0.5% by mass relative to the total amount of monomer components constituting the (meth)acrylic polymer A (meth)acrylic monomer containing a carboxyl group, and the crosslinking agent contains an aromatic isocyanate compound and an aliphatic isocyanate compound, and the antistatic layer is composed of polyaniline sulfonic acid as a conductive polymer component. It is formed by the polyester resin of the adhesive and the antistatic agent composition of the isocyanate crosslinking agent as the crosslinking agent. For example, the adhesive sheet of item 1 in the scope of patent application, wherein the antistatic agent composition further contains fatty amide as a lubricant. For example, the adhesive sheet of item 1 or 2 of the scope of patent application, relative to the total amount of monomer components constituting the (meth)acrylic polymer, further contains a monomer containing an amide group. An optical component, which is protected by the adhesive sheet of any one of items 1 to 3 in the scope of patent application.