TWI760326B - Adhesive composition and antistatic surface-protective film - Google Patents

Abstract

The present invention provides an adhesive composition and an antistatic surface-protection film. Which have excellent adhesive, antistatic and low-contamination performance.

The adhesive composition contains an acrylic based polymer, (D) an antistatic agent, (E) a crosslinking accelerator, and (F) a keto-enol tautomer compound. The acrylic based polymer is copolymerized by (a1) a (meth)acrylic acid ester monomer having a C1 to C4 alkyl group, (a2) a (meth)acrylic acid ester monomer having a C5 to C18 alkyl group, (B) a hydroxyl group-containing and /or a carboxyl group-containing copolymerizable vinylmonomer, and (C) a polyalkylene glycol mono(meth)acrylic acid ester monomer. The (D) antistatic agent is composed of a pentafluorophenyl borate anion and a cation, which is an ionic compound having a melting point higher than 25℃ and being solid at 25℃.

Description

Adhesive composition and antistatic surface protection film

The present invention relates to an adhesive composition containing an antistatic agent, and an antistatic surface protection film. In further detail, the present invention relates to an adhesive composition and an antistatic surface protection film using the adhesive composition. The adhesive composition contains a borate anion compound having a pentafluorophenyl group (C ₆ F ₅ group). As an antistatic agent, an adhesive layer having excellent adhesive properties and antistatic properties, and also excellent in low contamination properties can be obtained. In addition, the present invention also provides an adhesive composition and an antistatic surface protective film using the adhesive composition. The adhesive composition can obtain a low-cost fluorine-containing compound for lamination of an adherend on the surface of an optical film. The low-refractive-index layer formed from the composition for forming a refractive-index layer has excellent adhesive properties and antistatic properties, and is an adhesive layer with excellent low contamination properties.

When manufacturing and transporting optical films such as polarizing plates, retardation plates, lens films for displays, anti-reflection films, hard coat films, and transparent conductive films for touch panels, and optical products such as displays using these, A surface protection film is bonded to the surface of this optical film, and it can prevent the contamination or damage of the surface in a subsequent process. Appearance inspection of optical films as optical products, in order to save peeling off the surface protective film and The time for re-bonding may be performed in a state where the surface protection film is directly bonded to the optical film to improve work efficiency.

Conventionally, in order to prevent adhesion of damage and dirt in the manufacturing process of optical products, a surface protection film having an adhesive layer on one surface of a base film is generally used. The surface protection film is attached to the optical film through a micro-adhesive adhesive layer. The reason why the adhesive layer has a slight adhesive force is that it can be easily peeled off when the used surface protective film is peeled off from the surface of the optical film, and the adhesive does not adhere and remain on the optical film that is an adherend product (so-called. To prevent the generation of residual glue).

In recent years, in the production process of display panels, although the number of cases is small, the peeling electrostatic voltage generated when the surface protective film attached to the optical film is peeled off and removed has damaged the control panel of the display panel. A phenomenon in which circuit components such as driver ICs of the display screen are damaged, or a phenomenon in which the alignment of liquid crystal molecules is damaged.

In addition, in order to reduce the power consumption of the display panel, the driving voltage is lowered, and the breakdown voltage of the driving IC is also lowered along with this. Therefore, in order to prevent the inconvenience caused by the high peeling electrostatic voltage when peeling the surface protection film from the optical film which is the adherend, it has been proposed to use an antistatic agent containing a low peeling electrostatic voltage for suppressing the peeling electrostatic voltage. The surface protective film of the adhesive layer.

In addition, in recent years, in order to prevent dirt, fingerprints, etc. from adhering to a display panel or a touch panel, a layer containing a fluorine compound is provided on the surface.

For example, Patent Documents 1 and 2 describe an antireflection film and a polarizing plate in which hollow inorganic particles for imparting low refractive index properties are prepared in a low refractive index layer provided on the outermost surface of the antireflection film, and a Curable fluorocarbon that imparts antifouling properties fat.

In addition, Patent Document 3 describes an antireflection film having a low refractive index layer composed of perfluoroalkyl (meth)acrylate, modified polydimethylsiloxane having an acrylic group, A fluorine-containing compound having a polymerizable double bond and hollow silica particles are formed.

In addition, Patent Document 4 describes a surface protection film having an acrylic adhesive layer, in which a functional layer formed by a treatment with a fluorine-containing compound or a silicon-containing compound is used as an adherend, and is adhered on In the surface protective film of the adherend, polyether-modified polyorganosiloxane, fluorine-based surfactant containing fluorine-containing alkyl group, and acrylic-based polymer containing fluorine or silicon are added as fluorine-containing or silicon-containing compound.

prior art literature Patent Literature

Patent document: Japanese Patent Laid-Open No. 2010-277059

Patent document: Japanese Patent Laid-Open No. 2008-262187

Patent Document: Japanese Patent Laid-Open No. 2015-55659

Patent Document: Japanese Patent Laid-Open No. 2011-63712

In the antistatic surface protection film in which the surface protection film has antistatic properties, it is necessary to add an antistatic agent to the adhesive layer. Therefore, in order to improve the antistatic performance of the adhesive layer, if the content of the antistatic agent contained in the adhesive layer is increased, when the antistatic surface protection film is pasted on the adherend through the adhesive layer, the The amount of antistatic agent on the adherend increases, which becomes the cause of the contamination of the adherend. Therefore, the relationship between antistatic performance and low pollution to the adherend is a trade-off relationship. That is, it is difficult to improve the low contamination property while maintaining the antistatic function. However, in recent years, with the development of higher image quality and higher quality of display panels, the evaluation criteria for low contamination properties have become stricter. The low fouling properties are also excellent antistatic surface protection film.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an adhesive composition capable of obtaining an adhesive layer having excellent adhesion performance and antistatic performance, and excellent in low contamination properties, and an adhesive composition using the same. Antistatic surface protection film.

The inventors of the present application take the following content as the technical idea of the present invention: the number of alkyl carbon atoms of the alkyl (meth)acrylate that constitutes the main component of the acrylic polymer of the adhesive composition is limited within a specific range, An antistatic agent containing a borate anion having a pentafluorophenyl group is used together with a copolymer obtained by copolymerizing two or more alkyl (meth)acrylates in a specific combination. And it is found that the adhesive composition based on this technical idea can obtain an adhesive layer with excellent adhesion performance and antistatic performance, and also excellent in low pollution compared with the conventional adhesive composition for surface protection films, thereby completing the present invention. Apply for an invention.

That is, in the antistatic surface protection film formed using the adhesive composition of the present invention, an antifouling layer containing a fluorine compound or a low refractive index layer containing a fluorine compound is laminated on the surface of the optical film for the adherend The low refractive index layer formed by the composition for forming has excellent adhesion and antistatic properties, and low pollution Since it has excellent properties, it is possible to achieve both antistatic performance and low pollution.

That is, the present invention provides an adhesive composition comprising an acrylic polymer, an antistatic agent, and a crosslinking agent, wherein the acrylic polymer is such that the number of carbon atoms of the (A) alkyl group is C1 to C18 (meth)acrylate monomer, and at least one of (B) a copolymerizable vinyl monomer containing a hydroxyl group and/or a carboxyl group as a copolymerizable monomer group, (C) a polyalkylene glycol mono( A copolymer obtained by copolymerizing at least one or more of the meth)acrylate monomers, based on 100 weight of the total amount of the (meth)acrylate monomers having C1 to C18 carbon atoms in the (A) alkyl group parts, (a1) the carbon number of the alkyl group is that at least one of the (meth)acrylate monomers of C1～C4 is the ratio of 1～50 parts by weight, and the carbon number of the (a2) alkyl group is C5～C18 At least one of the (meth)acrylate monomers is in a ratio of 50 to 99 parts by weight, and in the aforementioned (a2), in a ratio of more than 50 parts by weight, it contains isooctyl (meth)acrylate, (meth)acrylate at least one of the group consisting of isononyl acrylate and 2-ethylhexyl (meth)acrylate, and the aforementioned (D) antistatic agent is a borate having a pentafluorophenyl group (C ₆ F ₅ group). The ionic compound is composed of anions and cations, and is a solid ionic compound with a melting point of 25°C or higher at a temperature of 25°C. The ionic compound is an essential component in a ratio of 0.1 to 10 parts by weight with respect to 100 parts by weight of the acrylic polymer. , the aforementioned adhesive composition further contains (E) a cross-linking accelerator and (F) a keto-enol tautomer compound.

The cation of the aforementioned ionic compound is preferably selected from the group consisting of pyridinium, imidazolium, perium, phosphonium, pyrrolidinium, guanidinium, ammonium, isuronium, thiouronium, piperidinium ), pyrazolium, methylium, One of the cationic groups consisting of lithium.

Preferably, the (B) hydroxyl group-containing copolymerizable monomer is selected from the group consisting of 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, (meth)acrylate group) a compound group consisting of 2-hydroxyethyl acrylate, N-hydroxy(meth)acrylamide, N-hydroxymethyl(meth)acrylamide, and N-hydroxyethyl(meth)acrylamide At least one or more of the aforementioned (B) carboxyl group-containing copolymerizable monomers are selected from (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(methyl) Acryloyloxyethylhexahydrophthalic acid, 2-(meth)acryloyloxypropylhexahydrophthalic acid, 2-(meth)acryloyloxyethylphthalic acid, 2 -(Meth)acryloyloxyethylsuccinic acid, 2-(meth)acryloyloxyethylmaleic acid, carboxypolycaprolactone mono(meth)acrylate, 2-(meth)propene At least one or more of the compound group consisting of oxoethyltetrahydrophthalic acid.

Preferably, the above-mentioned (C) polyalkylene glycol mono(meth)acrylate monomer is contained in a ratio of 1 to 50 parts by weight with respect to 100 parts by weight of the above-mentioned acrylic polymer, and the above-mentioned (C) polyextension The alkyldiol mono(meth)acrylate monomer is selected from the group consisting of polyalkylene glycol chains with an average repeating number of alkylene oxides of 3 to 14 and a diester component in the monomer of 0.2% or less At least one or more of polyalkylene glycol mono(meth)acrylate, methoxypolyalkylene glycol (meth)acrylate, and ethoxypolyalkylene glycol (meth)acrylate .

Preferably, the crosslinking accelerator (E) is at least one selected from the group consisting of aluminum chelate, titanium chelate, and iron chelate, and the amount is 0.001 to 0.5 with respect to 100 parts by weight of the acrylic polymer. The proportion by weight contains the aforementioned (E) cross-linking accelerator, and the aforementioned (F) ketone- For the enol tautomer compound, the weight ratio of the aforementioned (F)/the aforementioned (E) is 70 to 1000.

Moreover, this invention provides the adhesive film characterized by the lamination|stacking of the adhesive layer crosslinked by the said adhesive composition.

Preferably, the surface resistivity of the adhesive layer is 1.0×10 ⁺¹² Ω/□ or less, and the peeling electrostatic voltage for the low refractive index layer formed using the composition for forming a low refractive index layer containing a fluorine compound is ±0.3 kV. the following.

Furthermore, the present invention provides an antistatic surface protection film using the above-mentioned adhesive film.

Furthermore, the present invention provides an antistatic surface protection film for a polarizing plate using the above-mentioned adhesive film.

Further, the present invention provides an optical film with an adhesive in which an adhesive layer formed from the above-mentioned adhesive composition is laminated on at least one surface of the optical film.

In the above-mentioned adhesive film, it is preferable that an antistatic treatment and an antifouling treatment are applied to one surface of the resin film, that is, the opposite surface of the side where the adhesive layer is formed.

According to the present invention, it is possible to provide an adhesive composition capable of obtaining an adhesive layer having excellent adhesive performance and antistatic performance and excellent in low contamination properties, and an antistatic surface protection film using the same.

Hereinafter, the present invention will be described based on suitable embodiments.

The adhesive composition of the present invention is an adhesive composition containing an acrylic polymer, an antistatic agent and a crosslinking agent, wherein the acrylic polymer is characterized in that the number of carbon atoms of the (A) alkyl group is C1~ C18 (meth)acrylate monomer and at least one of (B) hydroxyl and/or carboxyl group-containing copolymerizable vinyl monomers as a copolymerizable monomer group, (C) polyalkylene glycol monomer A copolymer obtained by copolymerizing at least one of the (meth)acrylate monomers with respect to the total amount of the (meth)acrylate monomers having C1 to C18 carbon atoms in the (A) alkyl group, 100 Part by weight, (a1) the carbon number of the alkyl group is that at least one of the (meth)acrylate monomers of C1～C4 is the ratio of 1～50 parts by weight, (a2) the carbon number of the alkyl group is C5～ At least one of the (meth)acrylate monomers of C18 is in a ratio of 50 to 99 parts by weight, and in the aforementioned (a2), in a ratio of 50 parts by weight or more selected from isooctyl (meth)acrylate, ( At least one of the group consisting of isononyl meth)acrylate and 2-ethylhexyl (meth)acrylate, wherein the (D) antistatic agent is made of boric acid having a pentafluorophenyl (C ₆ F ₅ group) The salt anion and the cation are composed of an ionic compound having a melting point of 25°C or higher and a solid at a temperature of 25°C, and the ion is contained as an essential component in a ratio of 0.1 to 10 parts by weight with respect to 100 parts by weight of the acrylic polymer. A compound, the said adhesive composition further contains (E) a crosslinking accelerator, (F) a keto-enol tautomer compound.

(A) Among the (meth)acrylate monomers having C1 to C18 in the alkyl group, at least one of the (meth)acrylate monomers having C1 to C4 as the alkyl group (a1) One, butyl (meth)acrylate, isobutyl (meth)acrylate, methyl (meth)acrylate, (meth)acrylic acid Ethyl ester, propyl (meth)acrylate, isopropyl (meth)acrylate.

In addition, as (a2) the C5-C18 (meth)acrylate monomer of the alkyl group, pentyl (meth)acrylate, hexyl (meth)acrylate, and (meth)acrylic acid are exemplified. Heptyl ester, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, ( Decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, ( tetradecyl meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate Alkyl esters, myristyl (meth)acrylate, isomyristyl (meth)acrylate, cetyl (meth)acrylate, isocetyl (meth)acrylate, stearyl (meth)acrylate , (meth)isostearyl acrylate, etc.

The (meth)acrylate monomer having a carbon number of C1 to C18 in the (A) alkyl group preferably contains the carbon number of the (a1) alkyl group in a ratio of 1 to 50 parts by weight relative to 100 parts by weight of the total amount. Be at least one in the (meth)acrylate monomer of C1～C4, in the ratio of 50～99 parts by weight containing (a2) the carbon number of the alkyl group in the (meth)acrylate monomer of C5～C18 At least one of the above-mentioned (a1) is more preferably contained in a proportion of 3 to 45 parts by weight, and at least one of the above (a2) is contained in a proportion of 55 to 97 parts by weight, particularly preferably in a proportion of 5 to 45 parts by weight. It contains at least one of the aforementioned (a1) in a proportion of 55 to 95 parts by weight, at least one of the aforementioned (a2) in a proportion of 55 to 95 parts by weight, and most preferably contains at least one of the aforementioned (a1) in a proportion of 8 to 40 parts by weight, At least one of the aforementioned (a2) is contained in a ratio of 60 to 92 parts by weight.

In the above-mentioned acrylic polymer, the (meth)acrylate monomer having a carbon number of C1 to C18 in the (A) alkyl group with respect to the total amount of 100 parts by weight, in the above (a2), is preferably 50 parts by weight The above ratio contains at least one selected from the group consisting of isooctyl (meth)acrylate, isononyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, more preferably 50 to 99 parts by weight, more preferably 55 to 97 parts by weight, particularly preferably 55 to 95 parts by weight, and most preferably 60 to 92 parts by weight.

(B) At least one of hydroxyl and/or carboxyl group-containing copolymerizable vinyl monomers may be at least one hydroxyl group-containing copolymerizable vinyl monomer, or carboxyl group-containing copolymerizable vinyl monomers at least one of them. Alternatively, at least one of the hydroxyl group-containing copolymerizable vinyl monomers and at least one of the carboxyl group-containing copolymerizable vinyl monomers may be used simultaneously. In addition, at least one of the copolymerizable vinyl monomers containing a hydroxyl group and a carboxyl group may be used.

(B) As a hydroxyl group-containing copolymerizable monomer, (meth)acrylic acid hydroxyalkyl esters, hydroxyl group-containing (meth)acrylamides, etc. are mentioned. Specific examples of these are preferably selected from the group consisting of 8-hydroxyoctyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 2-(meth)acrylate. -At least one or more of the compound group consisting of hydroxyethyl ester, N-hydroxy(meth)acrylamide, N-hydroxymethyl(meth)acrylamide, and N-hydroxyethyl(meth)acrylamide . These (B) hydroxyl group-containing copolymerizable monomers do not have a polyalkylene glycol chain unlike (C) polyalkylene glycol mono(meth)acrylate monomers described later.

With respect to 100 parts by weight of the aforementioned acrylic polymer, it is preferable to contain (B) to the hydroxyl group-containing copolymerizable monomer in a ratio of 0.1 to 20 parts by weight in total. At least one or more, the ratio of 0.5 to 15 parts by weight is more preferred, the ratio of 2.0 to 14.0 parts by weight is particularly preferred, and the ratio of 2.5 to 12.0 parts by weight is most preferred.

(B) The carboxyl group-containing copolymerizable monomer is preferably selected from (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, and 2-(meth)acryloyloxy Ethylhexahydrophthalic acid, 2-(meth)acryloyloxypropylhexahydrophthalic acid, 2-(meth)acryloyloxyethylphthalic acid, 2-(methyl) ) Acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl maleic acid, carboxypolycaprolactone mono(meth)acrylate, 2-(meth)acryloyloxyethyl At least one or more of the compound group consisting of tetrahydrophthalic acid.

With respect to 100 parts by weight of the aforementioned acrylic polymer, at least one or more of (B) carboxyl group-containing copolymerizable monomers are preferably contained in a total amount of 0.0 to 1.0 parts by weight, more preferably 0.0 to 0.8 parts by weight, The ratio of 0.0 to 0.5 parts by weight is particularly preferred, and the ratio of 0.0 to 0.3 parts by weight is most preferred.

In the aforementioned acrylic polymer, as (B) a copolymerizable vinyl monomer containing a hydroxyl group and/or a carboxyl group, the copolymerizable monomer containing a carboxyl group may not be included (the ratio is 0.0 part by weight), and the copolymerizable monomer containing a carboxyl group may be included In the case of a monomer, the ratio is preferably 0.01 to 1.0 part by weight, more preferably 0.05 to 0.8 part by weight, particularly preferably 0.05 to 0.5 part by weight, and most preferably 0.05 to 0.3 part by weight, relative to 100 parts by weight of the aforementioned acrylic polymer.

As the (C) polyalkylene glycol mono(meth)acrylate monomer, as long as one hydroxyl group among a plurality of hydroxyl groups contained in the polyalkylene glycol is esterified as a (meth)acrylate chemical compound. Since the (meth)acrylate group is a polymerizable group, it can be copolymerized into the aforementioned acrylic polymer. The other hydroxyl groups may remain as OH, and may be alkyl ethers such as methyl ether or diethyl ether, saturated carboxylic acid esters such as acetate, and the like.

As an alkylene group which polyalkylene glycol has, an ethylidene group, a propylidene group, a butylene group, etc. are mentioned, but it is not limited to these. The polyalkylene glycol may be a copolymer of two or more polyalkylene glycols among polyethylene glycol, polypropylene glycol, polybutylene glycol, and the like. Examples of the copolymer of polyalkylene glycol include polyethylene glycol-polypropylene glycol, polyethylene glycol-polybutylene glycol, polypropylene glycol-polybutylene glycol, and polyethylene glycol-polypropylene glycol-polybutylene glycol. Diols, etc., the copolymer may be a block copolymer or a random copolymer.

(C) It is preferable that the average repeating number of the alkylene oxide which comprises a polyalkylene glycol chain of a polyalkylene glycol mono(meth)acrylate monomer is 3-14. The "average number of repetitions of alkylene oxide" means the part of the "polyalkylene glycol chain" contained in the molecular structure of the (C) polyalkylene glycol mono(meth)acrylate monomer , the average number of repeating alkylene oxide units.

In the (C) polyalkylene glycol mono(meth)acrylate monomer, the diester component in the monomer is preferably 0.2% or less. "The diester component in the monomer" means the content rate of the polyalkylene glycol di(meth)acrylate contained in the (C) polyalkylene glycol mono(meth)acrylate monomer ( weight%).

The (C) polyalkylene glycol mono(meth)acrylate monomer is preferably selected from the group consisting of polyalkylene glycol mono(meth)acrylate, methoxypolyalkylene glycol (methyl meth) ) at least one of acrylate and ethoxy polyalkylene glycol (meth)acrylate.

More specifically, polyethylene glycol-mono(meth)acrylate, polypropylene glycol-mono(meth)acrylate, polybutylene glycol-mono(meth)acrylic acid can be mentioned Ester, polyethylene glycol-polypropylene glycol-mono(meth)acrylate, polyethylene glycol-polybutylene glycol-mono(meth)acrylate, polypropylene glycol-polybutylene glycol-mono(meth)acrylic acid Esters, polyethylene glycol-polypropylene glycol-polybutylene glycol-mono(meth)acrylate; methoxypolyethylene glycol-(meth)acrylate, methoxypolypropylene glycol-(meth)acrylate , Methoxy polybutylene glycol-(meth)acrylate, Methoxy-polyethylene glycol-polypropylene glycol-(meth)acrylate, Methoxy-polyethylene glycol-polybutylene glycol-( meth)acrylate, methoxy-polypropylene glycol-polybutylene glycol-(meth)acrylate, methoxy-polyethylene glycol-polypropylene glycol-polybutylene glycol-(meth)acrylate; ethyl acetate Oxypolyethylene glycol-(meth)acrylate, ethoxypolypropylene glycol-(meth)acrylate, ethoxypolybutylene glycol-(meth)acrylate, ethoxy-polyethylene glycol - Polypropylene glycol-(meth)acrylate, ethoxy-polyethylene glycol-polybutylene glycol-(meth)acrylate, ethoxy-polypropylene glycol-polybutylene glycol-(meth)acrylate , ethoxy-polyethylene glycol-polypropylene glycol-polybutylene glycol-(meth)acrylate, etc.

It is preferable to contain (C) at least one or more of the polyalkylene glycol mono(meth)acrylate monomers in a ratio of 1 to 50 parts by weight in total with respect to 100 parts by weight of the aforementioned acrylic polymer, more preferably In order to contain in the ratio of 1-40 weight part, it is especially preferable to contain in the ratio of 1-30 weight part, and it is most preferable to contain in the ratio of 2-25 weight part.

(D) The antistatic agent is composed of a borate anion and a cation having a pentafluorophenyl group (C ₆ F ₅ group), and contains an ion that is a solid at a temperature of 25° C. having a melting point of 25° C. or higher as an essential component compound. Examples of borate anions having a pentafluorophenyl group (C ₆ F ₅ group) include (C ₆ F ₅ ) ₄ B ⁻ , (C ₆ F ₅ ) ₃ (C ₆ H ₅ )B ⁻ , and (C ₆ ). F ₅ ) ₂ (C ₆ H ₅ ) ₂ B ^- , (C ₆ F ₅ )(C ₆ H ₅ ) ₃ B ^- and the like.

Examples of cations of the aforementioned ionic compounds include nitrogen-containing onium cations such as pyridinium, imidazolium, pyrimidinium, pyrazolium, pyrrolidinium, and ammonium; onium cations such as phosphonium cations and peronium cations; Lithium and other alkali metal cations. Among them, it is preferably selected from pyridinium, imidazolium, peronium, phosphonium, pyrrolidinium, guanidinium, ammonium, isourium, thiouronium, pyridinium, pyrazolium, methylium, lithium and the like one of the cationic groups consisting of. When the cation is an organic cation, the organic cation may have one or two or more substituents. As a substituent of an organic cation, aliphatic groups, such as an alkyl group, and aromatic groups, such as a phenyl group, are mentioned.

It is preferable to contain the said ionic compound as (D) an antistatic agent in the ratio of 0.1-10 weight part with respect to 100 weight part of said acrylic polymers.

Specific examples of the ionic compound that can be used as the (D) antistatic agent include triphenylmethyl onium tetrakis(pentafluorophenyl) borate, 1-nonylpyridinium tetrakis(pentafluorophenyl) borate, 1-octylpyridinium tetrakis(pentafluorophenyl)borate, 1-dodecylpyridinium tetrakis(pentafluorophenyl)borate, lithium tetrakis(pentafluorophenyl)borate, 2-methyl base-1-dodecylpyridinium tetrakis (pentafluorophenyl) borate, etc.

When a polyisocyanate compound is used as a crosslinking agent, the (E) crosslinking accelerator may act as a catalyst for the reaction (crosslinking reaction) between the above-mentioned acrylic polymer and the crosslinking agent, and tertiary ones are exemplified. Amine compounds such as amines, metal chelate compounds, organotin compounds, organolead compounds, organometallic compounds such as organozinc compounds, and the like. In the present invention, as the crosslinking accelerator, a metal chelate compound or an organotin compound is preferable.

The metal chelate is a compound in which one or more polydentate ligands L are bonded to the central metal atom M. The metal chelate compound may or may not have one or more monodentate ligands X bound to the metal atom M. For example, when the general formula of the metal chelate compound having one metal atom M is represented by M(L) _m (X) _n , m≧1 and n≧0. When m is 2 or more, m pieces of L may be the same ligand or different ligands. When n is 2 or more, the n X's may be the same ligand or different ligands.

Examples of the metal atom M include Fe, Ni, Mn, Cr, V, Ti, Ru, Zn, Al, Zr, Sn, and the like.

Examples of the polydentate ligand L include methyl acetoacetate, ethyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, β-ketoesters such as stearyl acetoacetate, or β-diketones such as acetoacetone (also known as 2,4-pentanedione), 2,4-hexanedione, and benzoylacetone. These substances are keto-enol tautomeric compounds, and may also be enolates (eg, acetylacetonate) in which the enol is deprotonated in the polydentate ligand L.

Examples of the monodentate ligand X include halogen atoms such as chlorine atoms and bromine atoms, pentamyl, hexyl, 2-ethylhexyl, octyl, nonyl, decanyl, dodecyl aryloxy groups such as stearyl and octadecyloxy groups, alkoxy groups such as methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, and the like.

Specific examples of the metal chelate compound include tris(2,4-pentanedionato)iron(III), iron triacetate, titanium triacetate, ruthenium triacetate, Zinc acetylacetonate, aluminum triacetylacetonate, zirconium tetraacetylacetonate, tris(2,4-hexanedione)iron(III), bis(2,4-hexanedione)zinc, tris(2,4-hexanedione)zinc 4-Hexanedione) titanium, tris (2,4-hexanedione) aluminum, tetrakis (2,4-hexanedione) ketone) zirconium, etc.

As an organotin compound, a dialkyl tin oxide, the fatty acid salt of dialkyl tin, the fatty acid salt of divalent tin, etc. are mentioned. In the past, many dibutyltin compounds have been used, but in recent years, it has been pointed out that the toxicity of organotin compounds, especially tributyltin (TBT) contained in the dibutyltin compounds, is also concerned as an endocrine disruptor. From the viewpoint of safety, long-chain alkyl tin compounds such as dioctyl tin compounds are preferred. As a specific organotin compound, dioctyltin oxide, dioctyltin dilaurate, etc. are mentioned. Although Sn compounds can be used temporarily, in view of the tendency to use safer substances in the future, it is preferable to use metal chelates such as Al, Ti, Fe, etc., which are safer than Sn.

The (E) crosslinking accelerator in the adhesive composition of the present invention is preferably at least one selected from the group consisting of an aluminum chelate compound, a titanium chelate compound, and an iron chelate compound.

It is preferable to contain (E) a crosslinking accelerator in the ratio of 0.001-0.5 weight part with respect to 100 weight part of said acrylic polymers.

(F) As a keto-enol tautomer compound, methyl acetoacetate, ethyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, acetonitrile β-ketoesters such as stearyl acetate, or β-diketones such as acetylacetone, 2,4-hexanedione, and benzalacetone. These compounds can suppress the excessive viscosity of the adhesive composition after adding the cross-linking agent by blocking the isocyanate group of the cross-linking agent in the adhesive composition using the polyisocyanate compound as the cross-linking agent. Rise or gel, extending the pot life of the adhesive composition.

With respect to 100 parts by weight of the aforementioned acrylic polymer, preferably 0.1 to 300 parts by weight The proportion of parts contains (F) the keto-enol tautomer compound.

The (F) keto-enol tautomer compound has an effect of inhibiting crosslinking, contrary to the (E) crosslinking accelerator, so it is preferable to appropriately set the (F) keto-enol tautomer compound relative to ( E) The proportion of crosslinking accelerator. From the viewpoint of prolonging the pot life of the adhesive composition and improving the storage stability, the weight ratio of (F)/(E) is preferably 70-1000, more preferably 70-700, particularly preferably 80-600.

The adhesive composition of the present invention crosslinks the adhesive polymer when forming the adhesive layer. As a method for advancing the crosslinking reaction, it is possible to perform crosslinking by photocrosslinking such as ultraviolet (UV), but it is preferable that the adhesive composition contains a crosslinking agent.

As a crosslinking agent, a bifunctional or trifunctional or higher isocyanate compound, a bifunctional or trifunctional or higher epoxy compound, a bifunctional or trifunctional or higher acrylate compound, a metal chelate compound, etc. are mentioned. Among them, polyisocyanate compounds (difunctional or trifunctional or higher isocyanate compounds) are preferred.

It is preferable to contain a crosslinking agent in the ratio of 0.1-5 weight part with respect to 100 weight part of said acrylic polymers.

The bifunctional or higher isocyanate compound may be at least one or two or more selected from polyisocyanate compounds having at least two or more isocyanate (NCO) groups in one molecule. Polyisocyanate compounds are classified into aliphatic isocyanates, aromatic isocyanates, acyclic isocyanates, alicyclic isocyanates, and the like, but any of them can be used. Specific examples of the polyisocyanate compound include lipids such as hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and trimethylhexamethylene diisocyanate (TMDI). Aliphatic isocyanate compounds; diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate (H6XDI), dimethyl diphenylene diisocyanate (TOID) , Aromatic isocyanate compounds such as toluene diisocyanate (TDI).

Examples of the trifunctional or higher isocyanate compound include biuret-modified products or isocyanurate-modified products of bifunctional isocyanate compounds (compounds having two NCO groups in one molecule), trimethylolpropane ( TMP) or an adduct (modified polyol) of a trivalent or higher polyol (a compound having at least 3 or more OH groups in one molecule) such as glycerin.

As the bifunctional or higher isocyanate compound, only a trifunctional isocyanate compound or only a bifunctional isocyanate compound may be used. In addition, a trifunctional isocyanate compound and a bifunctional isocyanate compound can also be used together.

As the bifunctional isocyanate compound, a diisocyanate compound, which is an acyclic aliphatic isocyanate compound, reacts with a diol compound and can be used. For example, when a diisocyanate compound is represented by the general formula "O=C=N-X-N=C=O" (wherein X is a divalent group), and a diisocyanate compound is represented by the general formula "HO-Y-OH" (wherein Y is a divalent group) When group) represents a diol compound, as a compound which a diisocyanate compound and a diol compound generate|occur|produce by reaction, the compound represented by the following general formula Z is mentioned, for example.

[General formula Z]O=C=NX-(NH-CO-OYO-CO-NH-X) _n -N=C=O

Here, n is an integer of 0 or more. When n is 0, the general formula Z represents "O=C=N-X-N=C=O". As the bifunctional acyclic aliphatic isocyanate compound, a compound in which n in the general formula Z is 0 (a compound not reacted with a diol compound) may be contained. diisocyanate compound), but preferably contains a compound in which n is an integer of 1 or more as an essential component. The bifunctional acyclic aliphatic isocyanate compound may be a mixture of plural compounds of the general formula Z in which n is different.

The diisocyanate compound represented by the general formula "O=C=N-X-N=C=O" is an aliphatic diisocyanate. X is preferably an acyclic aliphatic divalent group. The aforementioned aliphatic diisocyanate is preferably a compound selected from the group consisting of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate One or more of the groups.

The diol compound represented by the general formula "HO-Y-OH" is an aliphatic diol. Y is preferably an acyclic aliphatic divalent group. As the aforementioned diol compound, those selected from the group consisting of 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, and 2-methyl-2-propyl-1,3-propanediol are preferred. , 2-ethyl-2-butyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol monohydroxypivalate, It is composed of one or more than two compounds in the group consisting of polyethylene glycol and polypropylene glycol.

Furthermore, as other components, surfactants, hardening accelerators, plasticizers, fillers, hardening retarders, processing aids, antiaging agents, antioxidants, polyethers can be appropriately added to the adhesive composition of the present invention. Conventional additives such as modified siloxane compounds. These additives may be used alone or in combination of two or more.

The acrylic polymer used in the adhesive composition of the present invention can be synthesized by copolymerizing the following: a1) At least one or more of (meth)acrylate monomers whose alkyl group has C1 to C4 carbon atoms, and (a2) At least one of the (meth)acrylate monomers whose carbon atoms in the alkyl group are C5 to C18; as the copolymerizable monomer group (B) in the copolymerizable vinyl monomer containing a hydroxyl group and/or a carboxyl group. At least one or more and (C) at least one of the polyalkylene glycol mono(meth)acrylate monomers. The polymerization method of the acrylic polymer is not particularly limited, and an appropriate polymerization method such as solution polymerization and emulsion polymerization can be used.

When preparing an acrylic polymer, it is preferable to perform a polymerization reaction under anhydrous conditions, such as solution polymerization using an anhydrous organic solvent, in order to reduce the mixing of water into the adhesive composition. In particular, since the (C) polyalkylene glycol mono(meth)acrylate monomer has high hydrophilicity, it is preferable to use one having a low water content.

In order to avoid an increase in the viscosity of the adhesive composition, it is preferable to reduce the amount of the multifunctional (more than bifunctional) monomer that can function as a crosslinking agent as much as possible for each monomer used for preparing the acrylic polymer. In particular, among the (C) polyalkylene glycol mono(meth)acrylate monomers, the corresponding diester components are di(meth)acrylates of bifunctional monomers, so the diester components are preferably used less.

The adhesive composition of the present invention can be prepared by adding a crosslinking agent, (D) an antistatic agent, (E) a crosslinking accelerator, (F) a keto-enol tautomer compound, Further, arbitrary additives are appropriately added and prepared.

The adhesive force of the adhesive layer obtained by crosslinking the adhesive composition is preferably 0.05 to 0.1 N/25 mm at a low-speed peeling speed of 0.3 m/min, and preferably the adhesive force at a high-speed peeling speed of 30 m/min. 1.0N/25mm or less. Thereby, even if the adhesive force is affected by the peeling speed, it is possible to obtain the performance with little change, and even by high-speed peeling, it is possible to peel off quickly Leave. In addition, even when the antistatic surface protection film is temporarily peeled off for re-sticking, excessive force is not required, and it is easy to peel off the adherend.

The gel fraction of the adhesive layer (adhesive after crosslinking) in which the adhesive composition of the present invention is crosslinked is preferably 95 to 100%. By setting the gel fraction high in this way, the adhesive force will not be too large at a low peeling speed, the elution of unpolymerized monomers or oligomers from the acrylic polymer can be reduced, and the low contamination property or the acrylic polymer can be improved. Durability at high temperature and high humidity, suppresses contamination by adherends.

The adhesive composition of the present invention has excellent antistatic properties due to the addition of the components (A) to (F) in a well-balanced manner, and has an excellent balance of adhesive force at a low-speed peeling speed and a high-speed peeling speed, Furthermore, it is also excellent in low pollution property. Since it can be applied to applications such as antistatic surface protection films for optical films such as polarizing plates, optical films with adhesives, and the like, it has high industrial utility value.

The adhesive film of the present invention is formed by laminating an adhesive layer obtained by crosslinking the adhesive composition of the present invention on at least one surface of a resin film. The antistatic surface protection film of this invention is formed using the adhesive film of this invention, and can be used suitably as an antistatic surface protection film for optical films, such as polarizing plates, for optical members, for example. The optical film with an adhesive of this invention is laminated|stacked with the adhesive layer which consists of the adhesive composition of this invention on at least one surface of an optical film.

Examples of the polarizing plate of the adherend of the pressure-sensitive adhesive layer include a polarizing plate (LR polarizing plate) to which a low-reflection surface treatment to make the reflectance 2% or less is applied, and a low-reflection plate to which a reflectance of 2% or less is applied. A polarizing plate (AG-LR polarizing plate) with surface treatment and anti-glare treatment applied. In addition, optical films such as polarizers, The optical member may have surface layers such as a low-refractive-index layer formed using the composition for forming a low-refractive-index layer containing a fluorine compound and an antifouling layer containing a fluorine-compound on the outermost surface to be bonded to the adhesive layer.

As a composition for forming a low refractive index layer (surface layer) containing a fluorine compound, for example, a fluororesin composition can be mentioned. In order to lower the refractive index of the low refractive index layer, the composition for forming a low refractive index layer may contain hollow particles such as hollow silica particles. As a refractive index of a low refractive index layer, 1.2-1.4 are mentioned, for example. The low-reflection surface treatment may have a high-refractive index layer under the low-refractive index layer having a higher refractive index than the surface low-refractive index layer. As a refractive index of a high refractive index layer, 1.5-1.9 are mentioned, for example. Between the low-refractive-index layer and the high-refractive-index layer, a medium-refractive-index layer may be laminated, and the refractive index thereof is an intermediate degree between the two.

The surface resistivity of the adhesive layer obtained by crosslinking the above-mentioned adhesive composition is preferably 1.0×10 ⁺¹² Ω/□ or less. In addition, the peeling electrostatic voltage at the time of peeling off the said adhesive bond layer after bonding to the low refractive index layer (antifouling layer) formed by using the composition for forming a low refractive index layer containing a fluorine compound via the said adhesive bond layer is preferable "±0.3kV or less". In addition, in the present invention, "±0.3kV or less" means 0 to -0.3kV and 0 to +0.3kV, that is, -0.3 to +0.3kV. When the surface resistivity is large, when the adhesive layer is peeled off from the adherend, the performance of electrostatic escape due to electrification is poor. Therefore, by making the surface resistivity sufficiently small, the peeling electrostatic voltage caused by the static electricity generated when the adhesive layer is peeled off from the adherend can be reduced, and the influence on the electrical control circuit of the adherend and the like can be suppressed.

As the base film of the adhesive layer and the release film (separator) for protecting the adhesive surface, resin films such as polyester films can be used. In the release film, on the surface of the side that is in contact with the adhesive surface of the adhesive layer, a polysiloxane (silicone)-based, fluorine-based mold release agents, etc. are subjected to mold release treatment.

In the resin film used as the base film, an antistatic treatment and an antifouling treatment may be applied to the surface opposite to the side where the adhesive layer is formed. As an antistatic treatment of a resin film, the antistatic treatment by application|coating of an antistatic agent, blending, etc. is mentioned. As the antifouling treatment of the resin film, antifouling treatment by siloxane-based and fluorine-based mold release agents or coating agents, silica fine particles, and the like can be exemplified.

Example

Hereinafter, the present invention will be further described by way of examples.

<Preparation of adhesive composition>

[Example 1]

Nitrogen gas was introduced into a reaction apparatus equipped with a stirrer, a thermometer, a reflux cooler, and a nitrogen gas introduction pipe, and the air in the reaction apparatus was replaced with nitrogen gas. Then, 15 parts by weight of methyl acrylate, 85 parts by weight of 2-ethylhexyl acrylate, 15.0 parts by weight of 8-hydroxyoctyl acrylate, 0.1 part by weight of acrylic acid, 20 parts by weight of polypropylene glycol monoacrylate (n =12), while adding 60 parts by weight of solvent (ethyl acetate). Then, 0.1 part by weight of azobisisobutyronitrile as a polymerization initiator was added dropwise over 2 hours, and the reaction was carried out at 65° C. for 6 hours to obtain an acrylic polymer having a weight average molecular weight of 500,000 and used in Example 1. solution. After adding 9.0 parts by weight of acetylacetone to the acrylic polymer solution and stirring, 2.0 parts by weight of CORONATE HX (isocyanurate of hexamethylene diisocyanate compound), 0.1 part by weight of titanium triacetylacetone, 0.9 parts by weight of triphenylmethyl onium tetrakis (pentafluorophenyl) borate was stirred and mixed to obtain the adhesive composition of Example 1.

[Examples 2 to 6 and Comparative Examples 1 to 3]

The adhesives of Examples 2 to 6 and Comparative Examples 1 to 3 were obtained in the same manner as in Example 1, except that the compositions of the adhesive compositions of Example 1 were as described in Table 1 and Table 2, respectively. agent composition.

In both Table 1 and Table 2, the numerical value of the weight part calculated|required by making the total amount of (a1) group and (a2) group 100 weight part is shown in a parenthesis. In addition, the compound name of the abbreviated symbol of each component used in Table 1 and Table 2 is shown in Table 3 and Table 4. In addition, CORONATE (registered trademark) HX, CORONATE HL, and CORONATE L are trade names of TOSOH CORPORATION, and Takenate (registered trademark) D-140N, D-127N, and D-110N are trade names of Mitsui Chemicals Corporation.

Regarding the (C) polyalkylene glycol mono(meth)acrylate monomer in Table 3, the numerical value of "n" is the average number of repetitions of alkylene oxides constituting the polyalkylene glycol chain. In C-1 to C-5 used in Examples 1 to 6, the average number of repetitions of alkylene oxides constituting the polyalkylene glycol chain is 3 to 14, and the diester component in the monomer is 0.2% or less . The diester content in the monomer of C-6 was 0.8%.

Regarding the (D) antistatic agent in Table 4, D-1 to D-5 used in Examples 1 to 6 are ionic compounds having a melting point of 25°C or higher and a solid at a temperature of 25°C. D-6 is an ionic compound having a melting point of 15°C and a liquid at a temperature of 25°C.

<Synthesis of Bifunctional Isocyanate Compound>

The bifunctional isocyanate compounds of Synthesis Examples 1 and 2 were synthesized by the following method. As shown in Tables 5 and 6, the diisocyanate and the diol compound were mixed in a molar ratio: NCO/OH=16, reacted at 120° C. for 3 hours, and then unreacted was removed under reduced pressure using a thin film evaporator diisocyanate to obtain the target bifunctional isocyanate compound.

<Manufacture of antistatic surface protection film>

[Example 1]

After the adhesive composition of Example 1 prepared as described above was coated on a release film composed of a polysiloxane-coated polyethylene terephthalate (PET) film, it was dried at 90° C. , remove the solvent, and obtain an adhesive sheet with an adhesive layer thickness of 25 μm. After that, the adhesive sheet was transferred on the opposite side of the antistatic and antifouling treated side of the polyethylene terephthalate (PET) film which had undergone antistatic and antifouling treatment on one side to obtain a Antistatic and antifouling treated PET film/adhesive layer/release film (polysiloxane-coated PET film)" of the laminated structure of the antistatic surface protection film of Example 1.

[Examples 2 to 6 and Comparative Examples 1 to 3]

In the same manner as the antistatic surface protection film of Example 1 described above, the antistatic surface protection films of Examples 2 to 6 and Comparative Examples 1 to 3 were obtained.

<Test method and evaluation>

After curing the antistatic surface protection films in Examples 1 to 6 and Comparative Examples 1 to 3 in an atmosphere of 23° C. and 50% RH for 7 days, peel off the release film (PET film coated with polysiloxane resin), and expose The antistatic surface protection film of the adhesive layer was used as a measurement sample of surface resistivity.

Further, the antistatic surface protection film with the exposed adhesive layer was attached to the surface of the polarizing plate through the adhesive layer, and after being placed for 1 day, autoclave treatment was performed at 50° C., 5 atmospheres, and 20 minutes at room temperature. It was left to stand for a further 12 hours, and was used as a measurement sample for adhesive force, peeling electrostatic voltage, and contamination. The polarizing plate of the adherend is an LR polarizing plate or an AG-LR polarizing plate, and a low-reflection surface treatment is applied, and a low-refractive index layer is formed on the surface using a low-refractive-index layer-forming composition containing a fluorine compound.

<Adhesion>

The measurement sample obtained above (a measurement sample obtained by attaching a 25 mm wide antistatic surface protection film to the surface of the polarizing plate of the adherend) was carried out in the 180° direction at a low peeling speed (0.3 m/min) and a high-speed peeling speed (30 m/min), and the measured peel strength was taken as the adhesive force (N/25 mm).

<Surface Resistivity>

After curing, before sticking to the polarizing plate of the above-mentioned adherend, peel off the release film (PET film coated with polysiloxane resin) to expose the adhesive layer, and use a resistivity meter Hiresta UP-HT450 (Mitsubishi Chemical Analytech Co., Ltd. manufacturing) to measure the surface resistivity (Ω/□) of the adhesive layer.

<Peeling Static Voltage>

When the measurement sample obtained above was peeled at 180° at a tensile speed of 30 m/min, high-precision electrostatic sensors SK-035 and SK-200 (manufactured by KEYENCE CORPORATION) were used to measure the charge of the polarizing plate of the above-mentioned adherend. For the generated voltage (electrostatic voltage), the maximum value of the measured values was used as the peeling electrostatic voltage (kV).

<Low pollution>

Using a laminating machine, the polarizing plate of the above-mentioned to-be-adhered body is attached to one surface of the glass plate through an adhesive layer such as a double-sided adhesive tape. Then, on the surface of the polarizing plate of the said to-be-adhered body, the adhesive layer of the antistatic surface protection film was bonded using a bonding machine. After storage for 3 days and 30 days in an environment of 23° C. and 50% RH, the antistatic surface protection film was peeled off, and the contamination state of the surface of the polarizing plate of the adherend was visually observed.

Regarding low contamination, the case where the surface of the polarizing plate of the adherend was free from contamination in both 3-day storage and 30-day storage was evaluated as "○", and there was slight contamination in either 3-day storage or 30-day storage The case with smear was evaluated as "△", and the case with contamination was evaluated as "X".

The evaluation results are shown in Table 7. In addition, the surface resistivity is represented by "m×10 ⁺ⁿ " as "mE+n" (where m is an arbitrary real value, and n is a positive integer). The "surface treatment of polarizing plate" indicates the type of polarizing plate (LR treatment or AG-LR treatment) of the aforementioned adherend.

[Table 7]

The antistatic surface protection films of Examples 1 to 6 are applied with LR treatment or AG-LR treatment and have a low-refractive index layer containing a fluorine compound on the surface of the polarizing plate of the above-mentioned adherend, and the peeling speed at a low speed is 0.3m. The adhesion force per minute is 0.05~0.1N/25mm, the adhesion force of the high-speed peeling speed of 30m/min is less than 1.0N/25mm, the surface resistivity is less than 1.0×10 ⁺¹² Ω/□, and the peeling electrostatic voltage is ±0.3 Below kV, the low contamination properties under 3-day storage and 30-day storage are also excellent.

That is, the antistatic surface protection film of the present invention has excellent adhesion performance and antistatic performance to an adherend, and is also excellent in low contamination properties, so that both antistatic properties and low contamination properties can be achieved.

In addition, regarding the (meth)acrylate monomer having a carbon number of C1 to C4 that does not contain (a1) an alkyl group in the acrylic polymer, and (D) the antistatic agent is a melting point of 15° C. at a temperature of 25° C. The antistatic surface protection film of Comparative Example 1, which is a liquid ionic compound at °C, has a high peeling electrostatic voltage and slightly inferior low contamination properties.

In addition, the acrylic polymer contains (a1) an alkyl group in a ratio of 80 parts by weight with respect to 100 parts by weight of the total amount of (meth)acrylate monomers having C1 to C18 carbon atoms in the (A) alkyl group. The number of carbon atoms is C1～C4 (meth)acrylate monomer, the (meth)acrylate monomer containing more than 20 parts by weight (a2) alkyl carbon number is C5～C18, and (D) ) The antistatic surface protective film of Comparative Example 2 in which the antistatic agent is an ionic compound with a melting point of 15°C and a liquid at a temperature of 25°C has excessive adhesion, high surface resistivity, high peeling electrostatic voltage, and low pollution Bad sex.

In addition, about the antistatic surface of Comparative Example 3 in which the acrylic polymer does not contain (C) polyalkylene glycol mono(meth)acrylate monomer, and the adhesive composition does not contain (D) antistatic agent The protective film has high surface resistivity, high peeling electrostatic voltage, and poor low pollution.

As a result, the antistatic surface protection films of Comparative Examples 1 to 3 could not achieve both excellent low contamination properties to adherends and excellent antistatic performance against peeling.

Claims (10)

An adhesive composition comprising an acrylic polymer, an antistatic agent and a crosslinking agent, wherein the aforementioned acrylic polymer is a (A) alkyl group having a carbon number of C1 to C18 ( The total amount of meth)acrylate monomers is 100 parts by weight, (a1) the carbon number of the alkyl group is that at least one of the (meth)acrylate monomers of C1～C4 is a ratio of 1～50 parts by weight, ( a2) At least one of the (meth)acrylic acid ester monomers whose carbon atoms of the alkyl group are C5 to C18 is in a ratio of 50 to 99 parts by weight, and in the aforementioned (a2), the proportion of 50 parts by weight or more contains optional At least one of the group consisting of isooctyl (meth)acrylate, isononyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and as a copolymerizable monomer group: (B ) A copolymer obtained by copolymerizing at least one of hydroxyl and/or carboxyl group-containing copolymerizable vinyl monomers, and (C) at least one or more of polyalkylene glycol mono(meth)acrylate monomers The acrylic polymer, as the aforementioned (C) polyalkylene glycol mono(meth)acrylate monomer, the average repeating number of alkylene oxides constituting the polyalkylene glycol chain is 3 to 14, and the mono The diester component in the body is 0.2% or less, and the aforementioned (D) antistatic agent is a solid with a melting point of 25°C or more and is solid at a temperature of 25°C and is selected from triphenylmethyl onium tetrakis (pentafluorophenyl) borate , 1-nonyl Pyridinium tetrakis (pentafluorophenyl) borate, 1-octylpyridinium tetrakis (pentafluorophenyl) borate, 1-dodecylpyridinium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) borate One or more ionic compounds selected from the group consisting of phenyl) lithium borate and 2-methyl-1-dodecylpyridinium tetrakis (pentafluorophenyl) borate, relative to 100 parts by weight of the aforementioned acrylic polymer The said ionic compound is contained in the ratio of 0.1-10 weight part as an essential component, and the said adhesive composition further contains (E) a crosslinking accelerator and (F) a keto-enol tautomer compound. The adhesive composition according to claim 1, wherein the (B) hydroxyl group-containing copolymerizable monomer is selected from the group consisting of 8-hydroxyoctyl (meth)acrylate, 6-hydroxy (meth)acrylate Hexyl ester, 4-hydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N -At least one or more of the compound group consisting of hydroxyethyl (meth)acrylamide, and the aforementioned (B) carboxyl group-containing copolymerizable monomer is selected from (meth)acrylic acid and carboxyethyl (meth)acrylate , carboxypentyl (meth)acrylate, 2-(meth)acryloyloxyethylhexahydrophthalic acid, 2-(meth)acryloyloxypropylhexahydrophthalic acid, 2-(meth)acryloyloxypropylhexahydrophthalic acid (Meth)acryloyloxyethylphthalic acid, 2-(meth)acryloyloxyethylsuccinic acid, 2-(meth)acryloyloxyethylmaleic acid, carboxypolycaprolactone At least one or more of the compound group consisting of ester mono(meth)acrylate and 2-(meth)acryloyloxyethyltetrahydrophthalic acid. The adhesive composition according to claim 1 or 2, wherein the (C) polyalkylene glycol mono(meth)acrylate monomer is selected from the group consisting of At least one of alkylene glycol mono(meth)acrylate, methoxypolyalkylene glycol (meth)acrylate, and ethoxypolyalkylene glycol (meth)acrylate, The said (C) polyalkylene glycol mono(meth)acrylate monomer is contained in the ratio of 1-50 weight part with respect to 100 weight part of said acrylic polymers. The adhesive composition according to claim 1 or 2, wherein the (E) crosslinking accelerator is selected from the group consisting of aluminum chelate, titanium chelate, and iron chelate. At least one or more, with respect to 100 parts by weight of the acrylic polymer, the above-mentioned (E) cross-linking accelerator is contained in a ratio of 0.001 to 0.5 parts by weight, and the above-mentioned (F) keto-enol is contained in a ratio of 0.1 to 300 parts by weight The tautomeric compound, the weight ratio of the aforementioned (F)/the aforementioned (E) is 70 to 1000. An adhesive film characterized in that, on one surface of a resin film, an adhesive layer obtained by crosslinking the adhesive composition according to any one of claims 1 to 4 of the patent application scope is laminated. The adhesive film according to claim 5, wherein the adhesive layer has a surface resistivity of 1.0×10 ⁺¹² Ω/□ or less, and is not more than The peeling electrostatic voltage of the formed low refractive index layer was ±0.3 kV or less. An antistatic surface protection film using the adhesive film as described in item 5 of the patent application scope. An antistatic surface protection film for polarizing plates, which uses the adhesive film described in item 5 of the patent application scope. An optical film with an adhesive, wherein, on at least one side of the optical film, An adhesive layer formed of the adhesive composition described in any one of claims 1 to 4 is laminated. The adhesive film according to claim 5, wherein an antistatic treatment and an antifouling treatment are performed on one surface of the resin film and the opposite surface on the side where the adhesive layer is formed.