KR102047658B1 - Adhesive composition and surface-protective film - Google Patents

Abstract

The present invention provides a pressure-sensitive adhesive composition and a surface protective film having excellent balance of adhesive force in a low peeling speed and a high peeling speed, excellent adhesion performance having stain resistance, and excellent antistatic performance without deterioration with time. The acid value which copolymerized the (meth) acrylic acid ester monomer whose carbon number of (A) alkyl group is C1-C18, the copolymerizable monomer containing (B) hydroxyl group, and the copolymerizable monomer containing (C) carboxyl group is 0.1-1.0. It contains the acryl-type polymer of a copolymer, and contains 2-ethylhexyl acrylate in the ratio of 70 weight part or more in 100 weight part of (meth) acrylic acid ester monomers of C1-C18 carbon number of (A) alkyl group, The crosslinking agent is a (D) trifunctional or higher isocyanate compound, and the antistatic agent is an ionic compound having a melting point of 25 to 50 ° C. having an anion having a number of fluorine atoms of F7 or more.

Description

Adhesive composition and surface protection film {ADHESIVE COMPOSITION AND SURFACE-PROTECTIVE FILM}

This invention relates to the adhesive composition and surface protection film containing an antistatic agent. In more detail, by sticking to the polarizing plate which comprises a liquid crystal display, the adhesive composition which has the outstanding adhesive performance for surface protection films used for protecting the surface of a polarizing plate, and does not deteriorate with time, and excellent antistatic performance and surface protection using the same It is a film.

Conventionally, in the manufacturing process of optical members, such as a polarizing plate which is a member which comprises a liquid crystal display, the surface protection film for temporarily protecting the surface of an optical member is stuck. This surface protection film is used only for the process of manufacturing an optical member, and it peels and removes from an optical member at the time of attaching an optical member to a liquid crystal display. Since the surface protection film for protecting the surface of such an optical member is used only in a manufacturing process, it may be generally called a process film.

Thus, in the surface protection film used in the process of manufacturing an optical member, the adhesive layer is formed in one side of the polyethylene terephthalate (PET) resin film which has optical transparency. The release film which carried out the release process for protecting the adhesive layer until it bonds to an optical member is bonded on an adhesive layer.

In addition, optical members, such as a polarizing plate, have the product test | inspection accompanying optical evaluation, such as the display capability of a liquid crystal display plate, a hue, contrast, and a foreign material mixing, in the state which bonded the surface protection film. For this reason, as a required performance with respect to a surface protection film, it is calculated | required that a bubble, a foreign material, and the low molecular weight component of an adhesive composition do not adhere to an adhesive layer, ie, having pollution resistance.

Moreover, when peeling a surface protection film from optical members, such as a polarizing plate, it is concerned that peeling charge which arises with the static electricity which arises when peeling an adhesive layer from an adherend affects the failure of the electrical control circuit of a liquid crystal display. . For this reason, it is calculated | required that an adhesive layer has the outstanding antistatic performance.

In recent years, as a polarizer protective layer (sometimes called a protective film) of a polarizing plate, acrylic resins, such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), etc. other than conventional triacetyl cellulose (TAC) The adoption of the material which is easy to produce peeling charge when peeling the surface protection film of a polarizing plate, such as polyester resin, a cyclic olefin type polymer, and polycarbonate, is expanding. For this reason, it is required that the antistatic performance calculated | required by the adhesive layer for surface protection films of a polarizing plate is excellent compared with the past.

Moreover, when finally peeling a surface protection film from optical members, such as a polarizing plate, it is calculated | required that it can peel quickly. The so-called adhesive force is required to change little by the peeling speed so that it can peel quickly also by high speed peeling.

As such, in recent years, as a required performance for the pressure-sensitive adhesive layer constituting the surface protective film, (1) balancing the adhesive force at a low peeling speed and a high peeling speed, (2) having pollution resistance, (3) Excellent antistatic performance is demanded in terms of ease of use in using a surface protective film.

However, although each of these (1)-(3) which is a required performance with respect to the adhesive layer which comprises a surface protection film can satisfy individual required performance, (1)-required for the adhesive layer of a surface protection film, It was a very difficult problem to satisfy all the required performances of (3) at the same time.

In order to solve such a problem, for example, (1) balancing the adhesive force at a low peeling speed and a high peeling speed, (2) having pollution resistance, and (3) excellent antistatic performance Proposals such as are known.

(1) In order to balance the adhesive force in the low speed peeling speed and the high speed peeling speed, the copolymer of the (meth) acrylic-acid alkylester which has an alkyl group of 7 or less carbon atoms, and a carboxyl group-containing copolymerizable compound is made into a main component, and this is a crosslinking agent. In the acrylic pressure-sensitive adhesive layer formed by cross-linking treatment, there is a problem that the pressure-sensitive adhesive adheres to the adherend side in the case of adhesion for a long period of time, and that the adhesiveness to the adherend over time is large. In order to avoid this, it is known to use the copolymer of the (meth) acrylic-acid alkylester which has a C8-C10 alkyl group, and the copolymerizable compound which has an alcoholic hydroxyl group, and formed the adhesive layer which carried out the crosslinking process with the crosslinking agent ( Patent document 1).

Moreover, what mix | blended a small amount of the copolymer of a (meth) acrylic-acid alkylester and a carboxyl group-containing copolymerizable compound with the same copolymer as above, and formed the adhesive layer which carried out the crosslinking process with the crosslinking agent, etc. is proposed. However, when they are used for surface protection of a plastic sheet or the like having a low surface tension and having a smooth surface, they may cause a peeling phenomenon such as lifting due to heating during processing or storage, or re-peeling during peeling at a high speed which is a manual work area. There was also a problem that the castle is falling.

In order to solve these problems, a) 1 to 15 weights of a) carboxyl group-containing copolymerizable compounds are contained in 100 parts by weight of a (meth) acrylic acid alkyl ester having a (meth) acrylic acid alkyl ester having an alkyl group having 8 to 10 carbon atoms as a main component. To a copolymer of a monomer mixture comprising c) 3 to 100 parts by weight of a vinyl ester of an aliphatic carboxylic acid having 1 to 5 carbon atoms, and a pressure-sensitive adhesive composition comprising a cross-linking agent or more equivalent to a carboxyl group of the component b). It is proposed (patent document 2).

In the pressure-sensitive adhesive composition described in Patent Literature 2, no peeling phenomenon such as lifting occurs during processing or storage, and the seizure property of the adhesive force is small over time, and excellent in re-peelability, and long-term storage, especially in a high temperature atmosphere Even if it saves, it can be re-peeled with a small force, it does not generate | occur | produce adhesive residue on a to-be-adhered body at that time, and it is said that it can be re-peeled with a small force even when high-speed peeling is performed.

In addition, about (2) what has pollution resistance, it is a carboxyl group-containing monomer of 0 mass parts or more and less than 0.5 mass parts, 0.6-9 mass parts of hydroxy group containing (meth) acrylic-type monomer, and 99.4-90.5 mass parts of (meth) acrylic acid ester monomer. 100 parts by mass of a (meth) acrylic copolymer having a weight average molecular weight of 100,000 to less than 1 million; And the adhesive composition containing 0.1-5 mass parts of carbodiimide type crosslinking agents is disclosed (patent document 3).

In the adhesive composition of patent document 3, the carbodiimide type crosslinking agent is used as a crosslinking agent of the (meth) acrylic-type copolymer of a specific composition. For this reason, the adhesive layer can be provided with the crosslinked structure which can follow the shrinkage by the pressure and temperature at the time of an autoclave process. For this reason, the pressure-sensitive adhesive layer formed by using the pressure-sensitive adhesive composition can suppress and prevent foaming even under high temperature and high pressure conditions (at the time of autoclave treatment), and is excellent in adherend contamination resistance and also excellent in transparency.

Moreover, about (3) the outstanding antistatic performance, the method etc. which mix an antistatic agent in a base film as a method for providing antistatic property to a surface protection film are disclosed. Examples of the antistatic agent include (a) various cationic antistatic agents having cationic groups such as quaternary ammonium salts, pyridinium salts and primary to tertiary amino groups, (b) sulfonate groups, sulfate ester base groups and phosphoric acid. Anionic antistatic agents having anionic groups such as ester bases and phosphonate groups, (c) amphoteric antistatic agents such as amino acid and amino sulfate esters, and (d) amino alcohol, glycerin and polyethylene glycol A ionic antistatic agent and (e) the polymer type antistatic agent which made high molecular weight of the above antistatic agent etc. are disclosed (patent document 4).

In recent years, it has been proposed to include such an antistatic agent in the base film or directly in the pressure-sensitive adhesive layer without coating the surface of the base film.

In addition, an antistatic pressure-sensitive adhesive composition wherein a salt having an anion having a fluoro group and a sulfonyl group is dispersed, wherein the salt having an anion having a fluoro group and a sulfonyl group is a polyether ester containing a polyether group in a main chain thereof. The antistatic adhesive composition characterized by being dispersed in the state melt | dissolved in the type plasticizer is disclosed (patent document 5).

In the adhesive composition of patent document 5, the ester formed from the mono or dicarboxylic acid which has a saturated or unsaturated acyclic hydrocarbon group as a plasticizer, and the alcohol which has a C1-C20 acyclic hydrocarbon group, or the said unsaturated acyclic type It is disclosed to use a plasticizer comprising an ester in which an unsaturated group in a hydrocarbon group is epoxidized. The mono or dicarboxylic acid having such a saturated or unsaturated acyclic hydrocarbon group has a carbon number close to the carbon number of the acrylic monomer constituting the acrylic copolymer used in the pressure-sensitive adhesive layer, thereby improving compatibility with the antistatic adhesive composition, It is said that bleeding out is suppressed because it is preferably maintained in the plasticizer acrylic antistatic adhesive composition.

Japanese Laid-Open Patent Publication No. 63-225677 Japanese Patent Application Laid-Open No. 11-256111 Japanese Unexamined Patent Publication No. 2011-122054 Japanese Patent Laid-Open No. 11-00729 Japanese Unexamined Patent Publication No. 2014-118469

As described above, in the prior art, as the required performance for the pressure-sensitive adhesive layer constituting the surface protection film, it is required to balance the adhesive force at the low peeling speed and the high peeling speed, to have stain resistance, and to excellent antistatic performance. Has been. However, even if it is possible to satisfy each individual required performance, it was not able to satisfy all the required performances required for the pressure-sensitive adhesive layer of the surface protective film at the same time.

This invention is made | formed in view of the said situation, The adhesive composition which is excellent in the balance of adhesive force in a low peeling speed and a high peeling speed, and also has the outstanding adhesive performance which has a stain resistance, and does not deteriorate with time, and has the outstanding antistatic performance, and It is a subject to provide a surface protection film.

In the pressure-sensitive adhesive composition having an antistatic performance and a surface protection film using the same, the relationship between the antistatic performance and the stain resistance to the adherend is a trade-off relationship, and it is extremely important to improve the stain resistance while maintaining the antistatic performance. It was difficult.

By the way, the inventors of the present invention have a copolymer obtained by copolymerizing a copolymerizable monomer containing a carboxyl group, a polyether-containing silicone compound, and an anion (eg, nonafluorobutanesulfonate anion) in which the number of fluorine atoms is F7 or more. It was found that an adhesive composition containing an antistatic agent composed of an ionic compound having a melting point of 25 ° C. or higher can solve this problem.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, this invention is an adhesive composition containing an antistatic agent and a crosslinking agent, Comprising: The said adhesive composition contains the (meth) acrylic acid ester monomer of C1-C18 carbon number of (A) alkyl group, and (B) hydroxyl group. An acrylic polymer of a copolymer having a copolymerizable monomer capable of copolymerizing a copolymerizable monomer containing a (C) carboxyl group with an acid value of 0.1 to 1.0, wherein the acrylic polymer has C1 to C18 carbon atoms of the (A) alkyl group. 2-ethylhexyl acrylate is contained in the ratio of 70 weight part or more in 100 weight part of (meth) acrylic acid ester monomers, The glass transition temperature of the said acrylic polymer is 0 degrees C or less, and the said crosslinking agent is (D) 3. Is an isocyanate compound of functional or higher, and the antistatic agent is composed of a cation and an anion having an anion having a number of fluorine atoms of F7 or more It is an ionic compound of 25-50 degreeC of melting | fusing point, Comprising: The said adhesive composition further contains (E) crosslinking retarder and (F) crosslinking catalyst other than a tin compound as a crosslinking catalyst, The adhesive composition characterized by the above-mentioned. do.

The adhesive composition of this invention is an adhesive composition for surface protection films bonded to the polarizer protective layer of a polarizing plate, The polarizer protective layer of the said polarizing plate is 1 type chosen from the group which consists of a TAC type film, a PMMA type film, and a PET type film, Moreover, it is preferable that the surface treatment performed on the surface of the polarizer protective layer of the said polarizing plate is 1 type chosen from the group which consists of untreated, AG process, LR process, AR process, AG-LR process, and AG-AR process.

The anion of the ionic compound is C ₆ F ₅ (CF ₂ ) _n COO ^— , C ₆ F ₅ (CF ₂ ) _n SO ₃ ^— , C ₆ F ₅ (CF ₂ ) _n O ^— , C ₆ F ₅ O ( CF ₂ ) _n SO ₃ ^— , (C ₆ F ₅ CO) ₂ N ^— , (C ₆ F ₅ CO) ₃ C ^— , (C ₆ F ₅ SO ₂ ) ₂ N ^— , (C ₆ F ₅ SO ₂ ) ₃ C ^— , (C ₆ F ₅ OSO ₂ ) ₂ N ^— , (C ₆ F ₅ OSO ₂ ) ₃ C ^— , (C ₆ F ₅ ) ₄ B ^— , CF ₃ (CF ₂ ) ₃ SO ₃ ^— It is preferable to contain at least 1 sort (s) selected from the group as an anion, and to contain the said ionic compound as an essential component in the ratio of 0.01-10 weight part with respect to 100 weight part of the said acrylic polymer.

The cation of the ionic compound is pyridinium, imidazolium, phosphonium, sulfonium, pyrrolidinium, guanidinium, ammonium, isuroronium, thiuronium, piperidinium, pyrazolium, methyllium, lithium, It is 1 type chosen from the group which consists of morpholinium, and it is preferable to contain the said ionic compound as an essential component in the ratio of 0.01-10 weight part with respect to 100 weight part of said acryl-type polymers.

Peeling of the said adhesive layer with respect to the low refractive index layer formed using the composition for low refractive index layer formation whose surface resistivity of the adhesive layer which crosslinked the said adhesive composition is 1.0x10 ^{+ 12} ohms / square or less, and contains a fluorine compound. A large voltage is in the range of -0.3 to +0.3 kPa, and the adhesive force at a low peel rate of 0.3 m / min to a polarizing plate of the pressure-sensitive adhesive layer formed by crosslinking the pressure-sensitive adhesive composition is 0.04 to 0.2 N / 25 mm, It is preferable that the adhesive force in peeling speed 30m / min is 2.0N / 25mm or less.

The copolymerizable monomer containing the said (B) hydroxyl group is 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl At least one or more selected from the group consisting of (meth) acrylates, N-hydroxy (meth) acrylamides, N-hydroxymethyl (meth) acrylamides, and N-hydroxyethyl (meth) acrylamides;

It is made by containing the copolymerizable monomer containing the said (B) hydroxyl group in the ratio of 0.1-10 weight part with respect to 100 weight part of C1-C18 (meth) acrylic acid ester monomers of the said (A) alkyl group,

The copolymerizable monomer containing the (C) carboxyl group is (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, 2- (meth) acryloyloxyethylhexahexaphthalic acid, 2- ( Meta) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl maleic acid, carboxypoly At least one selected from the group consisting of caprolactone mono (meth) acrylate and 2- (meth) acryloyloxyethyltetrahydrophthalic acid,

It is preferable to contain the copolymerizable monomer containing the said (C) carboxyl group in the ratio of 0.01-0.5 weight part with respect to 100 weight part of C1-C18 (meth) acrylic acid ester monomers of the said (A) alkyl group. .

The crosslinking retarder (E) is a ketoenol tautomer compound, the crosslinking retardant (E) is contained in an amount of 0.1 to 300 parts by weight based on 100 parts by weight of the acrylic polymer, and the crosslinking of (F) The catalyst is at least one metal chelate compound selected from the group consisting of an aluminum chelate compound, a titanium chelate compound and an iron chelate compound, and the ratio (F) of the crosslinking catalyst is 0.001 to 0.5 parts by weight based on 100 parts by weight of the acrylic polymer. It is contained, and it is preferable that the weight part ratio of said (E) / said (F) is 80-1000.

It is preferable that the said adhesive composition contains the polyether modified siloxane compound whose HLB value is 6-12 and the weight average molecular weight is 10,000 or less with respect to 100 weight part of the said acrylic polymer in the ratio of 0.01-0.5 weight part.

The weight average molecular weight which the said adhesive composition copolymerized the (meth) acrylic acid ester monomer of C1-C18 of an alkyl group with a polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer with respect to 100 weight part of said acrylic polymers is 10 It is preferable to contain the copolymer which is more than 10,000 and 300,000 or less in the ratio of 0.1-5.0 weight part.

The average repetition number of the alkylene oxide which the said polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer comprises a polyalkylene glycol chain is 3-14, and in the said polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer The diester content is 0.2% or less, and as said polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer, polyalkylene glycol mono (meth) acrylate, methoxy polyalkylene glycol (meth) acrylate, and ethoxy poly Containing at least one or more selected from the group consisting of alkylene glycol (meth) acrylates in a proportion of 1 to 50 parts by weight in 100 parts by weight of the copolymer having a weight average molecular weight greater than 100,000 and 300,000 or less. desirable.

Moreover, this invention provides the adhesive film characterized by the adhesive layer which bridge | crosslinked the said adhesive composition laminated | stacked on one side of a resin film.

In addition, the present invention provides a surface protection film using the adhesive film.

Moreover, this invention provides the surface protection film for polarizing plates in which the said adhesive film was used.

Moreover, this invention provides the optical film with an adhesive layer in which the adhesive layer which consists of the said adhesive composition is laminated | stacked on at least one surface of an optical film.

Moreover, this invention provides the said adhesive film in which antistatic treatment and antifouling treatment were given to the surface opposite to the side in which the said adhesive layer on one side of the said resin film was formed.

The pressure-sensitive adhesive composition according to the present invention has excellent adhesion performance and no deterioration with time and excellent peeling antistatic performance, as compared with a pressure-sensitive adhesive composition for a conventional surface protection film.

In particular, the surface protective film according to the present invention comprises a low refractive index layer formed by using an antifouling layer containing a fluorine compound, or a composition for forming a low refractive index layer containing a fluorine compound, in which an adherend is laminated on the surface of an optical film. In the case of a to-be-adhered body, compared with the surface protection film by a prior art, it is excellent in adhesive performance and does not deteriorate with time, and has the outstanding peeling antistatic performance. That is, the surface protection film which concerns on this invention has remarkable effect on both antistatic performance and pollution resistance.

That is, the pressure-sensitive adhesive composition and the surface protective film using the same according to the present invention have excellent adhesion performance and no deterioration with time, and have excellent peeling antistatic performance, and thus, the industrial useful value is extremely large.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated based on preferable embodiment.

The adhesive composition of this embodiment is an adhesive composition containing an antistatic agent and a crosslinking agent, and the said adhesive composition is copolymerizable which contains the (meth) acrylic acid ester monomer whose C1-C18 carbon number of (A) alkyl group and (B) hydroxyl group are contained. (Meth) whose acrylic polymer contains C1-C18 carbon number of the said (A) alkyl group, and contains the acryl-type polymer of the copolymer whose monomer and the acid value which copolymerized the copolymerizable monomer containing (C) carboxyl group are 0.1-1.0. 2-ethylhexyl acrylate is contained in the ratio of 70 weight part or more in 100 weight part of acrylate esters, The glass transition temperature of the said acrylic polymer is 0 degrees C or less, and the said crosslinking agent is (D) trifunctional or more isocyanate. Compound, wherein the antistatic agent comprises a cation and an anion having an anion having a number of fluorine atoms of F7 or more It is an ionic compound of 25-50 degreeC, The said adhesive composition is further characterized by containing (E) crosslinking retardant and (F) crosslinking catalysts other than a tin compound as a crosslinking catalyst.

The acrylic polymer used for the adhesive composition of this embodiment is a main polymer of an adhesive composition, and a glass transition temperature is 0 degrees C or less. Moreover, the copolymer whose acrylic polymer has a (meth) acrylic acid ester monomer whose C1-C18 carbon number of the (A) alkyl group is a main component is preferable.

(A) As a (meth) acrylic acid ester monomer whose C1-C18 carbon number of an alkyl group is methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (Meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acryl Laten, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (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, cyclopentyl (meth) acrylate, cyclohexyl (meth) Acrylate It can be given. The alkyl group of the alkyl (meth) acrylate monomer may be linear, branched or cyclic.

The acrylic polymer used for the adhesive composition of this embodiment contains 2-ethylhexyl acrylate in the ratio of 70 weight part or more in 100 weight part of (A) alkyl groups of the (meth) acrylic acid ester monomer whose C1-C18 carbon number is C1-C18, It is preferable to make.

The acrylic polymer used for the adhesive composition of this embodiment contains the monomer which can be copolymerized containing (B) hydroxyl group. (B) As a copolymerizable monomer containing a hydroxyl group, 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy At least one selected from the group consisting of ethyl (meth) acrylate, N-hydroxy (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, and the like. desirable.

It is preferable to contain the copolymerizable monomer containing the (B) hydroxyl group in the ratio of 0.1-10 weight part with respect to 100 weight part of C1-C18 (meth) acrylic acid ester monomers of the said (A) alkyl group, and it is 1.6 It is more preferable to contain in the ratio of -8.5 weight part, and it is especially preferable to contain in the ratio of 2.1-7.5 weight part.

The acrylic polymer used for the adhesive composition of this embodiment contains the copolymerizable monomer containing the (C) carboxyl group. As a monomer which can be copolymerized (C) containing a carboxyl group, (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (Meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl maleic acid, carboxy It is preferable that it is at least 1 sort (s) or more selected from the group of compounds which consist of polycaprolactone mono (meth) acrylate, 2- (meth) acryloyloxyethyl tetrahydrophthalic acid, etc.

It is preferable to contain the copolymerizable monomer containing the (C) carboxyl group in the ratio of 0.01-0.5 weight part with respect to 100 weight part of C1-C18 (meth) acrylic acid ester monomers of the said (A) alkyl group, and it is 0.01 It is more preferable to be contained in the ratio of -0.45 weight part, and it is especially preferable to contain in the ratio of 0.01-0.4 weight part.

The manufacturing method of the acrylic polymer contained in the adhesive composition which concerns on this embodiment is not specifically limited, A well-known polymerization method, such as a solution polymerization method and an emulsion polymerization method, can be used suitably. As for the weight average molecular weight of the copolymer of an acryl-type polymer, 50-300 million are mentioned, for example. It is preferable that the acid value of an acryl-type polymer is 0.1-1.0. For this reason, pollution resistance can be improved. Here, "acid value" is one of the indicators which show content of an acid, and is represented by the mg number of potassium hydroxide required in order to neutralize 1 g of polymers containing a carboxyl group.

The adhesive composition which concerns on this embodiment contains the (G) antistatic agent. (G) Antistatic agent of this embodiment is an ionic compound which consists of a cation and an anion which has an anion whose number of fluorine atoms is F7 or more. Melting | fusing point of this ionic compound is 25-50 degreeC, and it is preferable that it is solid at normal temperature (for example, 25 degreeC). It is preferable to contain the said ionic compound as an essential component in the ratio of 0.01-10 weight part with respect to 100 weight part of the said acrylic polymer.

Moreover, when it is necessary to raise the antistatic performance of an adhesive layer and to reduce the lower limit of surface resistivity to 1.0x10 ⁺ 10 ohms / square or less, the said ionic compound is 0.01-15 with respect to 100 weight part of the said acrylic polymer. It is more preferable to contain in ratio by weight.

As an anion of the ionic compound, C ₆ F ₅ (CF ₂ ) _n COO ^— , C ₆ F ₅ (CF ₂ ) _n SO ₃ ^— , C ₆ F ₅ (CF ₂ ) _n O ^— , C ₆ F ₅ O (CF ₂ ) _n SO ₃ ^— , (C ₆ F ₅ CO) ₂ N ^— , (C ₆ F ₅ CO) ₃ C ^— , (C ₆ F ₅ SO ₂ ) ₂ N ^— , (C ₆ F ₅ SO ₂ ) ₃ C ^— , (C ₆ F ₅ OSO ₂ ) ₂ N ^— , (C ₆ F ₅ OSO ₂ ) ₃ C ^— , (C ₆ F ₅ ) ₄ B ^— , CF ₃ (CF ₂ ) ₃ SO ₃ ^— At least 1 type or more selected from the group which consists of these is mentioned. N is an integer of 1 or more.

Examples of the cation of the ionic compound include pyridinium, imidazolium, phosphonium, sulfonium, pyrrolidinium, guanidinium, ammonium, isouronium, thiuronium, piperidinium, pyrazolium, methyllium, At least 1 sort (s) selected from the group which consists of lithium and morpholinium is mentioned.

As a specific example of the (G) antistatic agent, For example, methyltrioctyl ammonium tris (pentafluorobenzenesulfonyl) meted salt, 3-methyl-1- octylpyridinium nonafluorobutanesulfonate salt, 1 -Ethyl-3-methylimidazolium tetrakis (pentafluorophenyl) borate salt, 1-butyl-1-methylpiperidinium bis (pentafluorobenzenesulfonyl) imide salt, and the like.

The adhesive composition which concerns on this embodiment contains (D) trifunctional or more isocyanate compound as a crosslinking agent. (D) As a trifunctional or more than isocyanate compound, the biuret modified body and isosi of diisocyanates, such as hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, and xylylene diisocyanate, for example And adducts with trivalent or higher polyols such as an anurate modified product, trimethylolpropane, and glycerin. As a ratio of the (D) trifunctional or more isocyanate compound, the ratio of 0.01-5 weight part with respect to 100 weight part of acrylic polymers is mentioned, for example.

The adhesive composition which concerns on this embodiment may contain (E) crosslinking retarder. (E) As crosslinking retardants, β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, octyl acetate, acetoacetate, acetoacetate, lauryl acetoacetate, stearyl acetoacetate, acetylacetone, and 2,4-hexane (Beta) -diketone, such as dione and benzoyl acetone, is mentioned. These are ketoenol tautomer compounds, and in the pressure-sensitive adhesive composition having a polyisocyanate compound as a crosslinking agent, by blocking the isocyanate group of the crosslinking agent, excessive viscosity rise or gelation of the pressure-sensitive adhesive composition after the crosslinking agent is suppressed, The port life can be extended. The crosslinking retardant (E) is preferably a ketoenol tautomer compound, particularly preferably at least one or more selected from the group of compounds consisting of acetylacetone and ethyl acetoacetate. It is preferable to contain (E) crosslinking retarder in the ratio of 0.1-300 weight part with respect to 100 weight part of said acrylic polymer.

The adhesive composition which concerns on this embodiment may contain crosslinking catalysts other than a tin compound as (F) crosslinking catalyst. (F) A crosslinking catalyst should just be a substance which functions as a catalyst with respect to reaction (crosslinking reaction) of the said copolymer and a crosslinking agent, when using a polyisocyanate compound as a crosslinking agent. Examples of the crosslinking catalyst other than the tin compound include organic metal compounds such as amine compounds such as tertiary amines, metal chelate compounds, organic lead compounds, and organic zinc compounds.

(F) The metal chelate compound of the crosslinking catalyst 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 single-site ligands X bonded to the metal atom M. Specific examples of the metal chelate compound include tris (2,4-pentanedionate) iron (III), iron trisacetylacetonate, titanium trisacetylacetonate, ruthenium trisacetylacetonate, zinc bisacetylacetonate, aluminum tris Acetylacetonate, zirconium tetrakisacetylacetonate, tris (2,4-hexanedionate) iron (III), bis (2,4-hexanedionate) zinc, tris (2,4-hexanedionate) titanium, Tris (2, 4- hexane dionate) aluminum, tetrakis (2, 4- hexane dionate) zirconium, etc. are mentioned.

The (F) crosslinking catalyst is preferably at least one metal chelate compound selected from the group consisting of an aluminum chelate compound, a titanium chelate compound and an iron chelate compound. It is preferable to contain (F) crosslinking catalyst in the ratio of 0.001-0.5 weight part with respect to 100 weight part of the said acrylic polymer.

Since the (E) crosslinking retarder has an effect of suppressing crosslinking as opposed to (F) crosslinking catalyst, it is preferable to appropriately set the ratio of (E) crosslinking retardant and (F) crosslinking catalyst. In order to lengthen the pot life of an adhesive composition and to improve storage stability, it is preferable that the weight part ratio of (E) / (F) is 80-1000. Here, the weight part ratio of (E) / (F) is the value of the share obtained by dividing the weight part of (E) by the weight part of (F).

The adhesive composition which concerns on this embodiment may contain (H) polyether modified siloxane compound as an arbitrary component. (H) The polyether modified siloxane compound is a siloxane compound having a polyether group, and in addition to the usual siloxane unit [-SiR ¹ ₂ -O-], a siloxane unit having a polyether group [-SiR ¹ (R ² O (R ³ O) ) _n R ⁴ ) -O-]. Wherein R ¹ is one or two or more alkyl groups or aryl groups, R ² and R ³ are one or two or more alkylene groups, and R ⁴ is one or two or more alkyl groups or acyl groups (terminal groups) Indicates. Polyether group is polyoxyethylene may be mentioned an ethylene group [(C ₂ H ₄ O) _n] and a polyoxypropylene group [(C ₃ H ₆ O) _n], such as a polyoxyalkylene group of the. In the siloxane unit which has a polyether group, OH group (R < ⁴ > H in the said Formula) may be sufficient as the terminal of a polyether group.

(H) It is preferable that a polyether modified siloxane compound is a polyether modified siloxane compound whose HLB value is 6-12. Moreover, it is preferable that 0.01-0.5 weight part of (H) polyether modified siloxane compounds are contained with respect to 100 weight part of the said acrylic polymer, It is more preferable that 0.02-0.35 weight part is included, It contains 0.02-0.25 weight part It is especially preferable. An HLB value is hydrophilic lipophilic balance (hydrophilic lipophilic ratio) prescribed | regulated, for example by JISK3211 (surfactant term).

A polyether modified siloxane compound can be obtained by grafting the organic compound which has an unsaturated bond and a polyoxyalkylene group with the hydrosilylation reaction, for example with respect to the polyorganosiloxane main chain which has a silicon hydride group. Specifically, a dimethylsiloxane methyl (polyoxyethylene) siloxane copolymer, a dimethylsiloxane methyl (polyoxyethylene) siloxane, methyl (polyoxypropylene) siloxane copolymer, a dimethylsiloxane methyl (polyoxypropylene) siloxane polymer, etc. Can be mentioned.

By mix | blending a (H) polyether modified siloxane compound with an adhesive composition, the adhesive force and rework performance of an adhesive layer can be improved. (H) It is preferable that the weight average molecular weight of a polyether modified siloxane compound is 10000 or less. From the viewpoint of compatibility with the acrylic polymer, the lower the HLB value and the lower the molecular weight, the better the compatibility. However, if the polyether-modified siloxane compound has the low molecular weight, the HLB value is relatively high and the antistatic property is excellent even though the compatibility with the polymer is slightly low. Is obtained.

The adhesive composition which concerns on this embodiment is an arbitrary component, The weight average molecular weight which copolymerized the (meth) acrylic acid ester monomer whose carbon number of an alkyl group is C1-C18, and the (I) polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer. You may contain this 100,000 or more and 300,000 or less copolymer (henceforth "copolymer B") as an antistatic adjuvant. It is preferable that copolymer B is contained in the ratio of 0.1-5.0 weight part with respect to 100 weight part of the said acrylic polymer, It is more preferable to contain in the ratio of 0.1-3.5 weight part, It is contained in the ratio of 0.1-2.5 weight part Is particularly preferred.

(I) As a polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer, what is necessary is just the compound in which one hydroxyl group was esterified as (meth) acrylic acid ester among the several hydroxyl groups which polyalkylene glycol has. Since a (meth) acrylic acid ester group becomes a polymeric group, it can copolymerize to the said acrylic polymer. The polyalkylene glycol mono (meth) acrylate in which the other hydroxyl group is OH may be sufficient, and the alkoxy polyalkylene glycol mono (meth) acrylate etc. which the other hydroxyl group was converted into the alkyl ether may be sufficient.

As polyalkylene glycol which comprises a polyalkylene glycol chain, what is necessary is just a glycol compound which has 1 type, or 2 or more types of alkylene groups, For example, polyethyleneglycol, polypropylene glycol, polybutylene glycol, polyethyleneglycol poly Propylene glycol, polyethylene glycol polybutylene glycol, polypropylene glycol polybutylene glycol, polyethylene glycol polypropylene glycol polybutylene glycol, etc. are mentioned.

(I) It is preferable that the average repeating number of the alkylene oxide which the polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer comprises a polyalkylene glycol chain is 3-14. The "average repeat number of alkylene oxide" is an alkylene oxide unit in the part of the "polyalkylene glycol chain" contained in the molecular structure of the (I) polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer. The number of averages repeated. Moreover, it is preferable that the diester content in (I) polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer is 0.2% or less. A "diester powder in a monomer" is content rate (weight%) of the polyalkylene glycol di (meth) acrylic acid ester contained in the (I) polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer.

(I) As a polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer, Polyalkylene glycol mono (meth) acrylate, methoxy polyalkylene glycol (meth) acrylate, and ethoxy polyalkylene glycol (meth) It is preferable that it is at least 1 sort (s) or more selected from the group which consists of a) acrylate. As for the ratio of the (I) polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer in the said copolymer B, the ratio of 1-50 weight part is preferable in 100 weight part of said copolymer B, and 2-35 weight The ratio of parts is more preferable, and the ratio of 2-25 weight part is especially preferable.

As monomers other than the (I) polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer copolymerized to copolymer B, the monomer which can be copolymerized containing the C1-C18 (meth) acrylic acid ester monomer and hydroxyl group At least 1 type, such as these, is mentioned. As a specific example of these monomers, the (meth) acrylic-type monomer illustrated to the said (A), (B) etc., respectively are mentioned. The monomer copolymerized with copolymer B may differ from the monomer copolymerized with the said acrylic polymer. Copolymer B does not need to copolymerize the copolymerizable monomer containing a carboxyl group.

The adhesive composition of this embodiment is not limited to the additive mentioned above, Well-known additives, such as surfactant, a hardening accelerator, a plasticizer, a filler, a hardening retardant, a processing aid, an antioxidant, antioxidant, may be mix | blended suitably. These can be used individually or in combination of 2 or more types.

The adhesive composition of this embodiment is suitable as an adhesive composition for surface protection films bonded to the polarizer protective layer of a polarizing plate. Here, 1 type chosen from the group which the polarizer protective layer of a polarizing plate consists of a TAC type film, a PMMA type film, and a PET type film is mentioned. Here, TAC is triacetyl cellulose, PMMA is polymethyl methacrylate, and PET is abbreviation of polyethylene terephthalate.

The surface treatment applied to the surface of the polarizer protective layer of the polarizing plate may be one selected from the group consisting of untreated, AG treated, LR treated, AR treated, AG-LR treated, and AG-AR treated. Here, AG is anti glare, LR is low reflection, and AR is anti reflection.

As for the adhesive layer which crosslinked the adhesive composition of this embodiment, it is preferable that the surface resistivity of an adhesive layer is 1.0x10 ^{+ 12} ohms / square or less, It is more preferable that it is 5.0x10 ^{+ 11} ohms / square or less, It is more preferable that it is 1.0x10 ^{+ 11} It is especially preferable that it is ohm / square or less. If the surface resistivity is large, the performance of releasing the static electricity generated when the adhesive layer is peeled off from the adherend is poor. For this reason, by making surface resistivity small enough, the peeling electrification voltage which arises with the static electricity which arises when peeling an adhesive layer from a to-be-adhered body can be reduced, and it can suppress that affecting a to-be-adhered body.

In the pressure-sensitive adhesive layer crosslinked with the pressure-sensitive adhesive composition of the present embodiment, the peeling electrification voltage of the pressure-sensitive adhesive layer with respect to the low refractive index layer formed by using the composition for low refractive index layer formation containing a fluorine compound is in the range of -0.3 to +0.3 kPa. It is preferable to be inside. Examples of the fluorine compound used in the composition for forming the low refractive index layer include a fluorine-containing copolymer and a fluorinated alkyl group-containing silane which are one or two or more polymers such as fluorinated olefins, fluorinated vinyl ethers, and fluorinated alkyl (meth) acrylates. Condensates, such as a compound, are mentioned. The fluorine-containing copolymer may be copolymerized with a fluorinated monomer, as well as non-fluorinated monomers such as olefins, vinyl ethers and (meth) acrylates. The low refractive index layer may be combined with a high refractive index layer or the like to form an antireflection layer.

The adhesive force in the low speed peeling speed 0.3m / min is 0.04-0.2N / 25mm, and the adhesive force in the high speed peeling speed 30m / min is 2.0N / with respect to the polarizing plate of the adhesive layer which crosslinks the adhesive composition of this embodiment. It is preferable that it is 25 mm or less, and it is more preferable that the adhesive force in a high speed peeling speed of 30 m / min is 0.2-1.6 N / 25 mm. For this reason, the performance with little change of adhesive force is obtained also by peeling speed, and it becomes possible to peel quickly also by high speed peeling. Moreover, even when peeling a surface protection film once for re-adhesion, it does not require an excessive force and it is easy to peel from an adherend.

It is preferable that it is 95 to 100%, and, as for the gel fraction of the adhesive layer which crosslinks the adhesive composition of this embodiment, it is more preferable that it is 97 to 100%. As such, the gel fraction is high, so that the adhesive force does not become excessive at a low peeling speed, the elution of the unpolymerized monomer or oligomer from the copolymer is reduced, the rework property and the durability at high temperature and high humidity are improved, and the adherend is improved. Contamination can be suppressed.

The adhesive film of this embodiment forms the adhesive layer formed by bridge | crosslinking the adhesive composition of this embodiment in one side or both surfaces of a resin film. Moreover, the surface protection film of this embodiment is a surface protection film formed by forming the adhesive layer formed by bridge | crosslinking the adhesive composition of this embodiment to one side of a resin film. The adhesive composition of this embodiment is equipped with the outstanding antistatic performance, is excellent in the balance of adhesive force in the low speed peeling speed and the high speed peeling speed, and has pollution resistance. For this reason, it can use preferably as a use of the surface protection film of a polarizing plate.

Resin films, such as a polyester film, etc. can be used as a base film of an adhesive layer, and a release film (separator) which protects an adhesive surface.

Antistatic treatment and antifouling treatment may be performed on the surface opposite to the side on which the pressure-sensitive adhesive layer on one side of the resin film is formed. Examples of the antistatic treatment include coating and mixing of antistatic agents. Examples of the antifouling treatment include treatment with a silicone-based or fluorine-based release agent, a coating agent, silica fine particles, or the like. The release film may be subjected to a release treatment with a silicone-based, fluorine-based, long-chain alkyl-based release agent or the like on the side of the adhesive layer of the pressure-sensitive adhesive layer.

Moreover, the optical film in which the adhesive layer was formed can be obtained by laminating | stacking the adhesive layer which bridge | crosslinked the adhesive composition of this embodiment on at least one surface of an optical film. As an optical film, a polarizing film, retardation film, an antireflection film, an antiglare (anti glare) film, an ultraviolet absorbing film, an infrared absorption film, an optical compensation film, a brightness improving film, etc. are mentioned. As an apparatus to which an optical member is applied, a liquid crystal panel, an organic EL panel, a touch panel, etc. are mentioned.

In the case of optical surface protection films, such as a surface protection film for polarizing plates, and an adhesive film, it is preferable that a base film and an adhesive layer have sufficient transparency.

Example

Hereinafter, an Example is given and this invention is demonstrated concretely.

<Production of Acrylic Polymer Solution>

Example 1

Nitrogen gas was introduce | transduced into the reaction apparatus provided with the stirrer, the thermometer, the reflux cooler, and the nitrogen inlet tube, and the air in the apparatus was replaced with nitrogen gas. Thereafter, a solvent (ethyl acetate) was added to the reaction apparatus together with 90 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of methyl acrylate, 5.5 parts by weight of 8-hydroxyoctyl acrylate, and 0.2 parts by weight of acrylic acid. Then, 0.1 weight part of azobisisobutyronitrile was dripped over 2 hours as a polymerization initiator, it was made to react at 65 degreeC for 6 hours, and the acrylic polymer solution used in Example 1 was obtained.

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

Except having made the composition of a monomer the description of Table 1 (A)-(C), respectively, it carried out similarly to the acryl-type polymer solution used for the said Example 1, and is used for Examples 2-6 and Comparative Examples 1-3. An acrylic polymer solution was obtained.

<Production of Adhesive Composition and Surface Protective Film>

Example 1

With respect to the acrylic polymer solution of Example 1 prepared as above, 2.0 parts by weight of a crosslinking agent (coronate HX), 9 parts by weight of a crosslinking retardant (acetylacetone), 0.1 part by weight of a crosslinking catalyst (titanium trisacetylacetonate), and charging 0.9 weight part of inhibitors (methyl trioctyl ammonium tris (pentafluorobenzenesulfonyl) meted salt), 0.05 weight part of polyether modified siloxane compounds (HLB = 7), 0.2 weight part of copolymers B-1 (molecular weight 150,000) It added and stirred and mixed to obtain the adhesive composition of Example 1. After apply | coating this adhesive composition on a release film (silicone resin-coated PET film), the solvent was removed by drying at 90 degreeC, and the adhesive layer which is 20 micrometers in thickness was obtained. Then, the adhesive layer in which the release film was formed in the surface opposite to the antistatic and antifouling surface of the base film (PET film antistatic and antifouling on one surface) is transferred, and the "base film / adhesive layer / Release film "of the surface protection film of Example 1 which has a laminated structure.

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

The surface of Examples 2-6 and Comparative Examples 1-3 was made similarly to the surface protection film of Example 1 except having made the composition of an additive like the description of Table 1 (D)-(H) and copolymer B, respectively. A protective film was obtained.

In Table 1, the weight part of each component was calculated | required the sum total of the (meth) acrylic acid ester monomer whose C1-C18 carbon number of (A) alkyl group was 100 weight part.

Here, in Table 1, in each column of (D), (E), (F), (G), (H), and (copolymer B), 100 parts by weight of the acrylic polymer is used, and the content ratio of each component (weight Part) is shown in numerical values in parentheses.

In addition, the compound name of the symbol of each component used in Table 1 is shown to Tables 2-3. In Table 2, the compound name of the symbol of monomers other than the (I) polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer among the component monomers of the copolymer B shown in Table 3 is also included. On the other hand, Coronate (registered trademark) HX, HL, and L are brand names of Tosoh Corporation, and Takenate (registered trademark) D-140N is a brand name of Mitsui Chemicals Corporation.

Among the antistatic agents (G), G-1 to G-4 each have an anion having a number of fluorine atoms of F7 or more, and are ionic compounds having a melting point of 25 ° C or more and a solid. G-5 is an ionic compound which has an anion whose number of fluorine atoms is F5, and whose melting point is solid at 25 degreeC or more.

(H) In a polyether modified siloxane compound, all H-1 to H-6 have a weight average molecular weight of 10000 or less.

(I) In the polyalkylene glycol chain-containing mono (meth) acrylic acid ester monomer, the diester content in a monomer is 0.2% or less in I-1-I-3, and the diester content in a monomer is 0.8% in I-4. In addition, n in the column of the (I) group of Table 3 is a numerical value which shows the average repeating number of alkylene oxide.

<Test method and evaluation>

After the surface protection films in Examples 1-6 and Comparative Examples 1-3 were aged for 7 days in 23 degreeC and 50% RH atmosphere, respectively, it evaluated by the following test methods.

<Test method of adhesion>

After peeling a release film and exposing the adhesive layer on the surface of a polarizing plate through an adhesive layer, it was left to stand for 1 day, and then autoclaved at 50 degreeC, 5 atmospheres for 20 minutes, and further 12 at room temperature. What was left to stand for time was used as the measurement sample of adhesive force. The peeling strength measured by peeling the obtained measurement sample in 180 degree direction using a tensile tester at low speed (0.3 m / min) or high speed (30 m / min) was made into adhesive force.

Here, the polarizer protective layer of the polarizing plate is one kind selected from the group consisting of triacetyl cellulose (TAC), polymethyl methacrylate (PMMA), and polyethylene terephthalate (PET).

In addition, the LR polarizing plate and AG-LR polarizing plate are subjected to low reflection surface treatment with a composition in which the surface of the polarizer protective layer of the polarizing plate contains a fluorine compound.

<Test Method of Surface Resistivity>

After aging a surface protection film, before bonding to a polarizing plate, a release film is peeled off and an adhesive layer is exposed and the surface resistivity of an adhesive layer is measured using the resistivity meter Hirestar UP-HT450 (made by Mitsubishi Chemical Analyzer). It was.

<Test method of peeling large voltage>

The surface protection film which peeled the release film and showed the adhesive layer was bonded together to the polarizing plate which has the low refractive index layer formed using the composition for low refractive index layer formation containing a fluorine compound on a to-be-adhered surface. When the surface protection film was peeled 180 ° at a tensile speed of 30 m / min, the voltage (large voltage) generated by the charge of the adherend was measured using the high-precision electrostatic sensors SK-035 and SK-200 (manufactured by Keyence Co., Ltd.). And the maximum value of the measured value were made into peeling electrification voltage.

<Test method of pollution resistance>

The polarizing plate which gave the said low reflection (LR) surface treatment on one surface of the glass plate was bonded together using an adhesive machine through the adhesive layer (double-sided adhesive tape). Then, the surface protection film was bonded to the surface of the said polarizing plate using a bonding machine. After storage over a period of 3 days and 30 days in an environment of 23 ° C. and 50% RH, the surface protective film was peeled off and the contamination state on the surface of the polarizing plate was visually observed. As for the criterion for the stain resistance, the surface of the polarizing plate evaluated "○" for no contamination, "△" for slightly staining, and "x" for contamination.

In Table 4, the evaluation result about the surface protection film in Examples 1-6 and Comparative Examples 1-3 is shown. "Surface resistivity" was described by the method of making "m * 10 ^{+ n} " into "mE + n" (m is arbitrary real value and n is a positive integer). The column of "polarizer protective layer of polarizing plate" shows the material and surface treatment of the polarizer protective layer of the polarizing plate used by the adhesion test. Plain of "surface treatment" means unprocessed.

The surface protection films of Examples 1-6 are 0.04-0.2 N / 25 mm of adhesive force at the low speed peeling rate 0.3 m / min with respect to the polarizing plate which is a to-be-adhered body, and 2.0 N / 25 mm of the adhesive force at high speed peeling rate 30 m / min. Below, it was excellent in adhesive performance.

The surface protective films of Examples 1 to 6 have a surface resistivity of 1.0 × 10 ⁺¹² Ω / □ or less, and a low refractive index layer formed using a composition for forming a low refractive index layer containing a fluorine compound, The peeling electrification voltage of the adhesive layer was in the range of -0.3 to +0.3 kPa, and was excellent in antistatic performance.

Moreover, even after the surface protective film of Examples 1-6 was stored over the period of 3 days and 30 days, there was no contamination with the polarizing plate which is a to-be-adhered body, and also it was excellent in contamination resistance.

That is, it demonstrates that the subject of this invention was able to be solved by the evaluation result shown in Table 4 about the surface protection films of Examples 1-6.

In the surface protection film of the comparative example 1, the ratio of 2EHA was less than 50 weight part among 100 weight part of carbon number of the (meth) acrylic acid ester monomer of C1-C18 of the (A) alkyl group in the acrylic polymer contained in an adhesive composition. Moreover, the copolymerizable monomer containing the (C) carboxyl group is not copolymerized. Moreover, in the adhesive composition which concerns on the surface protection film of the comparative example 1, the antistatic agent contains the anion of F5 whose number of fluorine atoms is less than F7. For this reason, the surface protection film of the comparative example 1 had large adhesive force of the adhesive layer, high peeling electrification voltage, and was also bad in stain resistance.

Moreover, the acid value of the acrylic polymer contained in the adhesive composition of the surface protection film of the comparative example 2 exceeded 1.0, and the stain resistance was bad.

In addition, the surface protection film of the comparative example 3 contained the anion of F5 in which the antistatic agent contained in the adhesive composition contained the number of fluorine atoms less than F7, and was bad in fouling resistance.

Thus, the subject of this invention was not able to be solved in the surface protection films of Comparative Examples 1-3.

Claims (15)

As an adhesive composition containing an antistatic agent and a crosslinking agent,
The pressure-sensitive adhesive composition
(A) (meth) acrylic acid ester monomer which has C1-C18 carbon number of an alkyl group,
(B) a copolymerizable monomer containing a hydroxyl group,
(C) It contains the acrylic polymer of the copolymer whose acid value which copolymerized the copolymerizable monomer containing a carboxyl group is 0.1-1.0,
The acryl-based polymer comprises 2-ethylhexyl acrylate in a proportion of 70 parts by weight or more in 100 parts by weight of the (meth) acrylic acid ester monomer having 1 to 18 carbon atoms of the alkyl group (A),
The glass transition temperature of the said acrylic polymer is 0 degrees C or less,
The crosslinking agent is a (D) trifunctional or higher isocyanate compound,
The antistatic agent is an ionic compound having a melting point of 25 to 50 ° C. comprising a cation and an anion having an anion having a number of fluorine atoms of F7 or more,
The anion of the ionic compound is C ₆ F ₅ (CF ₂ ) _n COO ^— , C ₆ F ₅ (CF ₂ ) _n SO ₃ ^— , C ₆ F ₅ (CF ₂ ) _n O ^— , C ₆ F ₅ O ( CF ₂ ) _n SO ₃ ^— , (C ₆ F ₅ CO) ₂ N ^— , (C ₆ F ₅ CO) ₃ C ^— , (C ₆ F ₅ SO ₂ ) ₂ N ^— , (C ₆ F ₅ SO ₂ ) ₃ C ^— , (C ₆ F ₅ OSO ₂ ) ₂ N ^— , (C ₆ F ₅ OSO ₂ ) ₃ C ^— , (C ₆ F ₅ ) ₄ B ^— and CF ₃ (CF ₂ ) ₃ SO ₃ ^— (where , n is an integer of 1 or more);
The pressure-sensitive adhesive composition further comprises (E) a crosslinking retardant and a crosslinking catalyst other than a tin compound as (F) a crosslinking catalyst. The method of claim 1,
As an adhesive composition for surface protection films bonded to the polarizer protective layer of a polarizing plate,
The polarizer protective layer of the said polarizing plate is 1 type chosen from the group which consists of a TAC type film, a PMMA type film, and a PET type film, and the surface treatment performed on the surface of the polarizer protective layer of the said polarizing plate is unprocessed, AG process, LR Pressure-sensitive adhesive composition, characterized in that one kind selected from the group consisting of treatment, AR treatment, AG-LR treatment, AG-AR treatment. The method according to claim 1 or 2,
A pressure-sensitive adhesive composition comprising the ionic compound as an essential component in a ratio of 0.01 to 10 parts by weight based on 100 parts by weight of the acrylic polymer. The method according to claim 1 or 2,
The cation of the ionic compound is pyridinium, imidazolium, phosphonium, sulfonium, pyrrolidinium, guanidinium, ammonium, isuroronium, thiuronium, piperidinium, pyrazolium, methyllium, lithium, 1 type selected from the group consisting of morpholinium,
A pressure-sensitive adhesive composition comprising the ionic compound as an essential component in a ratio of 0.01 to 10 parts by weight based on 100 parts by weight of the acrylic polymer. The method according to claim 1 or 2,
The surface resistivity of the adhesive layer which bridge | crosslinked the said adhesive composition is 1.0 * 10 ^{+ 12} ohms / square or less,
The peeling electrification voltage of the said adhesive layer with respect to the low refractive index layer formed using the composition for low refractive index layer containing a fluorine compound exists in the range of -0.3-+0.3 kPa,
The adhesive force in the low speed peeling speed 0.3m / min is 0.04-0.2N / 25mm, and the adhesive force in the high speed peeling speed 30m / min is 2.0N / 25mm or less with respect to the polarizing plate of the adhesive layer which crosslinks the said adhesive composition. Pressure-sensitive adhesive composition, characterized in that. The method according to claim 1 or 2,
The copolymerizable monomer containing the said (B) hydroxyl group is 8-hydroxyoctyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl At least one or more selected from the group consisting of (meth) acrylates, N-hydroxy (meth) acrylamides, N-hydroxymethyl (meth) acrylamides, and N-hydroxyethyl (meth) acrylamides;
It is made by containing the copolymerizable monomer containing the said (B) hydroxyl group in the ratio of 0.1-10 weight part with respect to 100 weight part of C1-C18 (meth) acrylic acid ester monomers of the said (A) alkyl group,
The copolymerizable monomer containing the (C) carboxyl group is (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, 2- (meth) acryloyloxyethylhexahexaphthalic acid, 2- ( Meta) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl maleic acid, carboxypoly At least one selected from the group consisting of caprolactone mono (meth) acrylate and 2- (meth) acryloyloxyethyltetrahydrophthalic acid,
It is characterized by containing the copolymerizable monomer containing the said (C) carboxyl group in the ratio of 0.01-0.5 weight part with respect to 100 weight part of C1-C18 (meth) acrylic acid ester monomers of the said (A) alkyl group. Pressure-sensitive adhesive composition. The method according to claim 1 or 2,
The crosslinking retarder (E) is a ketoenol tautomer compound,
It is made by containing the said (E) crosslinking retardant in the ratio of 0.1-300 weight part with respect to 100 weight part of the said acrylic polymer,
The crosslinking catalyst (F) is at least one metal chelate compound selected from the group consisting of an aluminum chelate compound, a titanium chelate compound and an iron chelate compound,
It is made by containing the said (F) crosslinking catalyst in the ratio of 0.001-0.5 weight part with respect to 100 weight part of the said acrylic polymer,
The weight part ratio of said (E) / said (F) is 80-1000, The adhesive composition characterized by the above-mentioned. The method according to claim 1 or 2,
The pressure-sensitive adhesive composition, wherein the pressure-sensitive adhesive composition contains a polyether-modified siloxane compound having an HLB value of 6 to 12 and a weight average molecular weight of 10,000 or less, based on 100 parts by weight of the acrylic polymer, in a proportion of 0.01 to 0.5 parts by weight. The method according to claim 1 or 2,
The weight average molecular weight which the said adhesive composition copolymerized the (meth) acrylic acid ester monomer of C1-C18 of an alkyl group with a polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer with respect to 100 weight part of said acrylic polymers is 10 The pressure-sensitive adhesive composition containing more than 10,000 and not more than 300,000 copolymer at a ratio of 0.1 to 5.0 parts by weight. The method of claim 9,
The average repeating number of the alkylene oxide which the said polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer comprises a polyalkylene glycol chain is 3-14,
The diester content in the said polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer is 0.2% or less,
As said polyalkylene glycol chain containing mono (meth) acrylic acid ester monomer, polyalkylene glycol mono (meth) acrylate, methoxy polyalkylene glycol (meth) acrylate, and ethoxy polyalkylene glycol (meth) acrylate The pressure-sensitive adhesive composition comprising at least one selected from the group consisting of 1 to 50 parts by weight in 100 parts by weight of the copolymer having a weight average molecular weight of greater than 100,000 and 300,000 or less. The adhesive layer which bridge | crosslinked the adhesive composition of Claim 1 or 2 is laminated | stacked on one side of a resin film, The adhesive film characterized by the above-mentioned. The surface protection film in which the adhesive film of Claim 11 was used. The surface protection film for polarizing plates in which the adhesive film of Claim 11 was used. The optical film with an adhesive layer in which the adhesive layer which consists of an adhesive composition of Claim 1 or 2 is laminated | stacked on at least one surface of an optical film. The method of claim 11,
The adhesive film in which the antistatic process and the antifouling process are given to the surface opposite to the side in which the said adhesive layer of one side of the said resin film was formed.