JP6508203B2 - Pressure-sensitive adhesive composition for polarizer and pressure-sensitive adhesive sheet for polarizer - Google Patents

Description

  The present invention relates to a pressure-sensitive adhesive composition for a polarizer and a pressure-sensitive adhesive sheet for a polarizer. Specifically, the present invention is a pressure-sensitive adhesive composition for polarizer to be directly attached to a polarizer and a pressure-sensitive adhesive sheet for polarizer, and the pressure-sensitive adhesive composition for polarizer and pressure-sensitive adhesive for bonding a polarizer and an optical member It relates to a sheet.

  In the liquid crystal cell of a liquid crystal display (LCD), it is necessary to dispose polarizing plates on both sides of a display substrate from an image forming system, and one side of this polarizing plate is attached to another optical component such as a liquid crystal cell. A pressure-sensitive adhesive layer is formed.

  In general, in the polarizing plate, transparent protective films are provided on both sides of a polarizer made of a polyvinyl alcohol film and a dichroic dye such as iodine. Since the polarizer has problems such as weak physical strength and tearing in the processing direction, the above-mentioned transparent protective film is bonded on at least one side, usually both sides, via an adhesive layer. The polarizing plate used in the conventional liquid crystal cell has a three-layer structure in which a polarizer is sandwiched between two triacetyl cellulose (TAC) protective films, or a TAC protective film and a cycloolefin polymer ( There is a three-layered structure in which a polarizer is sandwiched between a COP and a protective film.

  When sticking a polarizing plate to a liquid crystal cell etc., a pressure sensitive adhesive is usually used. The pressure-sensitive adhesive is provided in advance as a pressure-sensitive adhesive layer on one side of the polarizing plate because of convenience such as being able to fix the polarizing plate instantaneously and not requiring a drying step to fix the polarizing plate.

  When bonding a polarizing plate to a liquid crystal cell, static electricity may occur. Since such static electricity causes a foreign matter to be trapped by foreign matter adsorption due to a failure or charging of the liquid crystal cell, the adhesive layer is required to have an antistatic performance. For example, in patent documents 1-3, in order to give antistatic property to an adhesive layer, generally it contains an ionic compound.

  Further, in recent years, with the thinning of touch panels such as smartphones, the thinning of optical components of liquid crystal cells is also in progress. A polarizing plate is no exception, and a polarizing plate in which a protective film is formed on at least one side of a polarizer instead of a transparent protective film has been proposed (Patent Document 4). Moreover, the polarizing plate in which the protective film which improved durability in severe environment was formed is proposed (patent document 5). Furthermore, in order to thin the polarizing plate, the transparent protective film on the side on which the pressure-sensitive adhesive layer of the polarizing plate is provided is eliminated, and a polarizing plate having a configuration in which the pressure-sensitive adhesive layer is directly provided on the polarizer is studied.

JP, 2013-100386, A JP, 2013-108031, A JP, 2014-62264, A Unexamined-Japanese-Patent No. 2003-185842 Unexamined-Japanese-Patent No. 2010-9027

  However, when the transparent protective film of the polarizer is eliminated and the pressure-sensitive adhesive layer is directly provided on the polarizer, polyvinyl alcohol (PVA) which is a component of the polarizer is obtained using the pressure-sensitive adhesive layer having the conventional antistatic performance. The inventors of the present invention have clarified that the color loss (deterioration of the polarizer) of the dichroic dye such as iodine, which is adsorbed and oriented, occurs.

  Therefore, the present inventors are a pressure-sensitive adhesive composition having an antistatic performance, and a pressure-sensitive adhesive composition for polarizers and a pressure-sensitive adhesive which does not cause loss of color or deterioration of the polarizer even when directly attached to the polarizer. The study was advanced for the purpose of providing a sheet.

The present inventors investigated the cause to solve the above problems, and found out that the cause of color loss of the polarizer is the antistatic agent for imparting the antistatic performance contained in the pressure-sensitive adhesive layer. . Therefore, as a result of intensive investigations by the present inventors, it has been found that the use of an antistatic agent having a specific composition in the pressure-sensitive adhesive composition can suppress color loss of the polarizer without impairing the antistatic performance. The Specifically, the present inventors have developed an antistatic composition in which a salt having a fluoro group and an anion having a sulfonyl group is dissolved in a plasticizer containing a polyether group in the main chain to an acrylic adhesive. It has been found that the decoloring of the polarizer can be suppressed without impairing the antistatic performance by dispersing it stably and uniformly and using it for bonding the polarizer and the optical member. Furthermore, the present inventors have found that the polarizing plate can be thinned by using such a pressure-sensitive adhesive composition for a polarizer, and the present invention has been completed.
Specifically, the present invention has the following configuration.

[1] A composition containing an antistatic composition, wherein the antistatic composition has a composition in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved in a plasticizer containing a polyether group in the main chain A pressure-sensitive adhesive composition for a polarizer characterized in that
[2] The antistatic composition is a composition in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved in a polyether ester plasticizer containing a polyether group in the main chain [1 The pressure-sensitive adhesive composition for a polarizer according to above.
[3] An adhesive composition for a polarizer according to [2], wherein the polyether ester plasticizer comprises at least one polyether ester plasticizer represented by the following formula (1) or (2);
In formulas (1) and (2), m and n are each an integer, and R represents an alkyl group.
The antistatic composition is a composition in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved in a polyether plasticizer containing a polyether group in its main chain [1] The pressure-sensitive adhesive composition for a polarizer according to 4.
[5] The pressure-sensitive adhesive composition for a polarizer according to [4], wherein the polyether-based plasticizer contains a polyether-based plasticizer having the following formula (11);
R ¹ (OCH ₂ CH ₂ ) _n OR ² (11)
In the formula, ^{R 1} represents an alkyl group having 1 to 12 carbon atoms, ^{R 2} represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. n represents an integer of 3 to 6;
[6] An antistatic composition comprises a polyether ester-based plasticizer containing a polyether group in its main chain, a composition in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved, and a polyether [1] The pressure-sensitive adhesive composition for a polarizer according to [1], which comprises a composition in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved in a polyether plasticizer containing a group in the main chain.
[7] The pressure-sensitive adhesive composition for polarizer according to any one of [1] to [6], which is a pressure-sensitive adhesive composition having a carboxyl group as a main component.
[8] The pressure-sensitive adhesive composition for polarizer according to any one of [1] to [7], wherein the pressure-sensitive adhesive composition for a polarizer is an acrylic pressure-sensitive adhesive composition as a main component.
[9] The acrylic pressure-sensitive adhesive composition contains a (meth) acrylic copolymer (A) and a crosslinking agent (B), and the (meth) acrylic copolymer (A) has (i) 1 to 18 carbon atoms Monomer (meth) acrylic acid ester monomer having an alkyl group of 60 to 99.99% by mass and (ii) a monomer having a radically polymerizable unsaturated group and having at least one reactive functional group: 0.01 to 20 The pressure-sensitive adhesive composition for a polarizer according to [8] obtained by polymerizing at least% by mass.
[10] The pressure-sensitive adhesive composition for a polarizer according to [9], wherein the monomer having a reactive functional group is a carboxy group-containing monomer.
[11] The proportion of the carboxy group-containing monomer used for the polymerization of the (meth) acrylic copolymer (A) is 0.05 with respect to the total mass of the monomers used for the polymerization of the (meth) acrylic copolymer (A) The adhesive composition for polarizers as described in [10] which is -10 mass%.
[12] The crosslinking agent (B) is at least one selected from an isocyanate crosslinking agent, an epoxy crosslinking agent, and a metal chelate crosslinking agent, for the polarizer according to any one of [9] to [11] Adhesive composition.
[13] The content of the antistatic composition is 0.01 to 30 parts by mass with respect to 100 parts by mass of the (meth) acrylic copolymer (A) according to any one of [9] to [12] Polarizer pressure-sensitive adhesive composition.
[14] An anion having a fluoro group and a sulfonyl group is an anion selected from the group consisting of bis (fluoroalkylsulfonyl) imide ion, tris (fluoroalkylsulfonyl) methide ion and fluoroalkylsulfonic acid ion [1] The pressure-sensitive adhesive composition for a polarizer according to any one of [13].
[15] A salt provided with an anion having a fluoro group and a sulfonyl group is at least one cation selected from an alkali metal, a group 2 element, a transition metal and an amphoteric metal, and an anion having a fluoro group and a sulfonyl group The adhesive composition for light polarizers in any one of [1]-[14] which is a salt which consists of these.
[16] An alkali metal salt of bis (fluoroalkylsulfonyl) imide, an alkali metal salt of tris (fluoroalkylsulfonyl) methide and an alkali metal of trifluoroalkylsulfonic acid, with a salt having an anion having a fluoro group and a sulfonyl group The pressure-sensitive adhesive composition for a polarizer according to any one of [1] to [15], which is a salt selected from the group consisting of salts.
[17] The pressure-sensitive adhesive composition for polarizer according to any one of [1] to [16], which is for bonding a polarizer and an optical member.
[18] The pressure-sensitive adhesive composition for a polarizer according to [17], wherein the optical member is a liquid crystal cell or a touch panel.
The adhesive sheet for polarizers containing the adhesive composition for polarizers in any one of [19] [1]-[17].
[20] An image display device provided with at least one pressure-sensitive adhesive sheet according to [18].

  According to the present invention, even when the pressure-sensitive adhesive composition is attached or laminated directly to at least one surface of the polarizer, the polarization does not impair the antistatic performance and does not cause decolorization or deterioration of the polarizer. A child pressure-sensitive adhesive composition and a polarizer pressure-sensitive adhesive sheet can be provided. The pressure-sensitive adhesive composition for light-polarizer and the pressure-sensitive adhesive sheet are directly stuck to the light-polarizer, and the light-polarizer and the optical member are bonded via the pressure-sensitive adhesive composition for light-polarizer or the pressure-sensitive adhesive sheet for light-polarizer. For this reason, thickness reduction of a polarizing plate is also attained.

FIG. 1 is a view for explaining the function and effect of the antistatic composition used in the present invention. FIG. 2 is a view for explaining the structure of a polarizing plate containing the pressure-sensitive adhesive composition for a polarizer of the present invention and the structure of a conventional polarizing plate. FIG. 3 shows the results of HPLC (high-performance liquid chromatography) of the antistatic composition used in the examples, the extract of the antistatic composition-containing pressure-sensitive adhesive sheet, and the extract of the pressure-sensitive adhesive sheet not containing the antistatic composition. It is a chromatogram.

  Hereinafter, the present invention will be described in detail. The description of the configuration requirements described below may be made based on typical embodiments and specific examples, but the present invention is not limited to such embodiments. In addition, the numerical range represented using "-" in this specification means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.

(Pressure-sensitive adhesive composition for polarizer)
The pressure-sensitive adhesive composition for a polarizer of the present invention is a pressure-sensitive adhesive composition directly attached to at least one surface of a polarizer, and is a pressure-sensitive adhesive composition used to bond a polarizer and an optical member. is there. The pressure-sensitive adhesive composition for a polarizer of the present invention contains an antistatic composition. Here, the antistatic composition is a composition in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved in a plasticizer containing a polyether group in the main chain. Since the pressure-sensitive adhesive composition for a polarizer of the present invention is configured as described above, the polarizer and the pressure-sensitive adhesive layer are in close contact with each other flexibly. Moreover, since the pressure-sensitive adhesive composition for a polarizer of the present invention can be directly attached or laminated to a polarizer, a thin protective plate without a transparent protective film or a protective layer can be produced. As described above, even a polarizing plate with no protective film, etc., is excellent in heat resistance in a high temperature or high temperature / high humidity environment or in an environment where heating and cooling are repeated, and the temperature history and pressure sensitive adhesive component Decoloring (deterioration) of the polarizer caused by the migration of the preventive component) can be suppressed.

(Antistatic composition)
The antistatic composition for use in the pressure-sensitive adhesive composition for a polarizer of the present invention comprises a plasticizer containing a polyether group in its main chain and a salt having an anion having a fluoro group and a sulfonyl group dissolved in the plasticizer. It is a composition. That is, in the antistatic composition, a salt having an anion having a fluoro group and a sulfonyl group is dispersed in a state of being dissolved in a plasticizer containing a polyether group in the main chain.

  The antistatic composition used in the pressure-sensitive adhesive composition for a polarizer of the present invention is selected from alkali metals, group 2 elements, transition metals and amphoteric metals in a plasticizer containing a polyether group in its main chain. It is also a composition in which a salt with at least one cation is dissolved. The cation is preferably any cation selected from alkali metals and Group 2 elements, and more preferably an alkali metal cation. Among them, the cation is preferably lithium ion.

Here, in the pressure-sensitive adhesive composition for a polarizer of the present invention, a cation which is a counter ion of an anion is coordinated to an oxygen atom of ether in a plasticizer to form a complex. That is, a cation which is a counter ion of an anion having a fluoro group and a sulfonyl group forms a Lewis acid / base complex ion with a plasticizer containing a polyether group in its main chain. In the antistatic composition used in the present invention, a cation which is a counter ion of an anion having a fluoro group and a sulfonyl group is coordinated to an oxygen atom of an ether in a plasticizer containing a polyether group in the main chain. It is characterized in that it contains the complex.
The cation forming a complex ion with the plasticizer is preferably at least one cation selected from an alkali metal, a group 2 element, a transition metal and an amphoteric metal, and more preferably a lithium ion. That is, the complex to be formed is preferably a lithium polyether complex.

The antistatic composition used in the pressure-sensitive adhesive composition for a polarizer of the present invention detects a complex-derived peak when it is analyzed by HPLC (high performance liquid chromatography). This peak is not detected only by the antistatic composition containing only a salt or the plasticizer containing a polyether group in the main chain, and is a peak derived from a complex.
The HPLC conditions are as follows.
Column; X Bridge C18, column diameter 4.6 x 250 mm (manufactured by Waters)
Column temperature; 30 ° C
Mobile phase; acetonitrile / water flow rate; 0.8 mL / min.
Detection: 225 nm

  In the present invention, by using such an antistatic composition, it is possible to prevent color loss of the polarizer even when the pressure-sensitive adhesive composition is directly attached to the polarizer. In the present specification, “dispersion” refers to a state in which a salt having an anion having a fluoro group and a sulfonyl group is dispersed or dissolved in a plasticizer. As such an antistatic composition, for example, Sanconol AD2326 (manufactured by Sanko Chemical Co., Ltd.), Sanconol AD 2600 (manufactured by Sanko Chemical Co., Ltd.), Sanconol TGR (manufactured by Sanko Chemical Co., Ltd.), etc. may be mentioned.

When a pressure-sensitive adhesive composition for a polarizer containing a conventional ionic compound is directly applied to a polarizer, cations bleed out and bloom due to the poor fluidity of the ionic compound and the compatibility with the acrylic pressure-sensitive adhesive composition. As a result, a pseudo bond is formed with the iodine ion (I ³⁻ , I ⁵⁻ ) of the polarizer, which causes the color loss of the polarizer. On the other hand, since the antistatic composition used in the present invention is dispersed in the state of being dissolved in a plasticizer having high affinity to the acrylic pressure-sensitive adhesive composition, bleed out and blooming do not occur. Furthermore, since the cation of the antistatic composition forms a complex ion of the Lewis acid / base type with the plasticizer, it does not form a chemical bond with the iodine ion of the polarizer.

  The content of the antistatic composition is preferably 0.01 to 30 parts by mass with respect to 100 parts by mass of the (meth) acrylic copolymer contained in the pressure-sensitive adhesive composition for a polarizer, More preferably, it is 10 parts by mass. By setting the content of the antistatic composition within the above range, sufficient antistatic performance can be exhibited, and problems such as precipitation of the antistatic composition in a low temperature environment can be suppressed. it can.

(Polyether ester plasticizer)
The antistatic composition is preferably a composition in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved in a polyether ester plasticizer containing a polyether group in the main chain. The polyether ester plasticizer contains a polyether group and an ester bond, and prevents the resin from being regularly oriented by entering into the resin gap. Further, the polyether ester plasticizer refers to one that maintains an amorphous state even at the glass transition point or lower. Among them, the polyether ester plasticizer is preferably a polyether ester compound represented by the following formula (1) or (2).

  In formulas (1) and (2), m and n are each an integer, and R represents an alkyl group.

  Polyether ester plasticizers have low viscosity and good workability, have low temperature flexibility, have a balance of heat aging resistance, flexibility and durability, non-volatility, non-migration, oil resistance, Excellent in safety (PL compliance).

  R is preferably an alkyl group having 1 to 14 carbon atoms. For example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, n-pentyl group, n-nonyl group, isononyl group, n-decyl group, n-lauryl group and the like are preferable.

  In formulas (1) and (2), m is preferably an integer of 1 to 40, and n is preferably an integer of 1 to 20. More preferably, m and n are integers of 2 or more. In particular, m is preferably an integer of 2 or more.

  The polyether ester plasticizer having a polyether group in the main chain preferably has a molecular weight of 250 to 2,000, and more preferably 500 to 1,500. It is preferable that (25 degreeC) of the viscosity of a polyether-ester type plasticizer is 30-600 mPa * s.

(Polyether plasticizer)
The antistatic composition may be a composition in which a salt provided with an anion having a fluoro group and a sulfonyl group is dissolved in a polyether plasticizer containing a polyether group in the main chain. In addition, the antistatic composition comprises a polyether ester plasticizer containing a polyether group in its main chain, a composition in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved, and a polyether group. And a composition in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved in a polyether plasticizer containing in the main chain thereof. Here, the polyether plasticizer is preferably a polyalkylene glycol (di or mono) alkyl ether compound represented by the following general formula (11).

In formula (11), R ¹ represents a C 1-12 alkyl group, and R ² represents a hydrogen atom or a C 1-12 alkyl group. n represents an integer of 3 to 6;

  The polyether plasticizer is particularly preferably a polyalkylene glycol alkyl ether compound.

(Other plasticizers)
Further, the antistatic composition may further contain a plasticizer besides the polyether ester-based or polyether-based plasticizer described above. As such a plasticizer, an ester formed from a mono- or dicarboxylic acid having a saturated or unsaturated non-cyclic hydrocarbon group and an alcohol having a non-cyclic hydrocarbon group having 1 to 20 carbon atoms, or Mention may be made of plasticizers in which the unsaturated group in the unsaturated acyclic hydrocarbon group is an epoxidized ester. By using such an ester, the wettability of the pressure-sensitive adhesive layer to the adherend can be improved, and it is possible to prevent the occurrence of air bubbles during adhesion, and the plasticizer bleeds out of the pressure-sensitive adhesive layer. It is hard to produce and it can reduce to-be-adhered body contamination suitably.

  Examples of the saturated or unsaturated acyclic hydrocarbon group in the mono- or dicarboxylic acid component constituting the ester include an alkyl group and an alkylene group, and among them, an alkyl group or an alkylene group having 1 to 20 carbon atoms is preferable. It is more preferable that it is a C4-C18 alkyl group, and a C4-C14 alkyl group is especially preferable. 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 pressure-sensitive adhesive composition used for the pressure-sensitive adhesive composition for a polarizer By having the number, the compatibility with the pressure-sensitive adhesive composition for polarizers becomes good, and since it is suitably held in the pressure-sensitive adhesive composition for polarizers, the bleed out is suppressed.

  Examples of monocarboxylic acids and dicarboxylic acids having a saturated or unsaturated acyclic hydrocarbon group include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid. Mono- or polyesters of linear aliphatic dicarboxylic acids such as dodecanedioic acid, acetic acid, propionic acid, butyric acid, chitosan acid, capconic acid, enanthate, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid , Myristic acid, pentadecyl acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, saturated fatty acid such as arachic acid, crotonic acid, angelica acid, lindelic acid, myristoleic acid, palmitoleic acid, oleic acid, vacenic acid, gadoleic acid , Eicosenoic acid, erucic acid, nervonic acid, linoleic acid, Ikosajien acid, docosadienoic acid, linolenic acid, pinolenic acid, eleostearic acid, mead acid, stearidonic acid, arachidonic acid, eicosatetraenoic acid, adrenic acid, elaidic acid, and unsaturated fatty acids such as docosahexaenoic acid.

  As a C1-C20 non-cyclic hydrocarbon group in alcohol which comprises ester, a C1-C20 alkyl group and an alkylene group, especially an alkyl group can be used suitably, Especially, C4-C4 is preferable An alkyl group of 18 is preferable, and an alkyl group having 4 to 14 carbon atoms is particularly preferable. The alcohol having such a saturated or unsaturated acyclic hydrocarbon group has a carbon number close to that of the acrylic monomer constituting the acrylic pressure-sensitive adhesive composition contained in the pressure-sensitive adhesive composition for polarizers By this, the compatibility with the pressure-sensitive adhesive composition for polarizers becomes good, and since it is suitably held in the pressure-sensitive adhesive composition for polarizers, the bleed out is suppressed. The carbon number of the hydrocarbon group possessed by the alcohol component is lower than the carbon number of the acrylic monomer constituting the acrylic pressure-sensitive adhesive composition used in the pressure-sensitive adhesive composition for a polarizer, as compared to the carboxylic acid component constituting the ester In particular, by setting the number of carbon atoms close to that of the above, it is easy to suppress the contamination of the adherend.

  Examples of alcohols having such non-cyclic hydrocarbon groups include methyl alcohol, ethyl alcohol, propanol, butanol, pentanol, hexanol, heptanol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, dodecyl alcohol Examples thereof include linear and branched alcohols of tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, octadecyl alcohol, nonadecyl alcohol and arachyl alcohol. Among them, butanol, pentanol, hexanol, heptanol, octyl alcohol, nonyl alcohol and decyl alcohol can be particularly preferably used.

  In the present invention, in addition to the above-mentioned polyether ester plasticizer and / or polyether plasticizer, an ester formed from the above mono- or dicarboxylic acid and alcohol may be used as a plasticizer. The ester may have a skeleton composed of a saturated or unsaturated hydrocarbon group, but is preferably an ester not having a skeleton composed of an unsaturated hydrocarbon group. In addition, an epoxidized ester in which an unsaturated bond of an ester having a skeleton composed of the unsaturated hydrocarbon group is epoxidized can also be preferably used. Among the esters, adipic acid monoester, sebacic acid monoester and epoxidized fatty acid monoester can be particularly preferably used.

  The ester used as a plasticizer may be either a monoester or a polyester, but it is easy to control the solubility parameter (SP value) within a suitable range, and the compatibility with the pressure-sensitive adhesive composition for a polarizer is improved. It is preferable that the weight average molecular weight in PS conversion is 1000 or less, and it is especially preferable that it is an ester of 300 to 800, because it is easy to cause.

  As a plasticizer, it is preferable to use a plasticizer having a solubility parameter (SP value) of 8.5 or less. Among them, 7.0 to 8.4 is preferable. Since it is excellent in compatibility with an acrylic pressure-sensitive adhesive composition that the SP value of the plasticizer is 8.5 or less, the pressure-sensitive adhesive composition for a polarizer is attached to a polarizer in a high temperature and high humidity environment for a long time. Even when left for a long time, when peeling from the surface of the polarizer, it becomes difficult to generate haze on the surface of the polarizer. Plasticizers having a SP value of greater than 7.0 are generally used. In addition, said SP value is J.I. Small expression proposed by Small [P. A. J. Small: J. Appl. Chem. , 3, 71 (1953)].

  It is preferable to add 0.5-30 mass parts with respect to 100 mass parts of (meth) acrylic copolymers which comprise an acrylic adhesive composition, and, as for the said plasticizer, adding 1-20 mass parts It is more preferable to add 1 to 10 parts by mass. When the additive amount of the plasticizer is more than 0.5 parts by mass, air bubbles are easily released when pasting. If the amount is less than 30 parts by mass, fogging is unlikely to occur on the display surface even in a high temperature and high humidity environment.

(Salt with anion having a fluoro group and a sulfonyl group)
The salt provided with the anion having a fluoro group and a sulfonyl group is easily soluble in the polyether ester plasticizer and the polyether plasticizer, and the salt concentration in the plasticizer can be increased. By dispersing this solution in the pressure-sensitive adhesive composition for polarizers, it is possible to incorporate a salt having a fluoro group and an anion having a sulfonyl group into the pressure-sensitive adhesive composition for polarizers in a large amount and uniformly. . In the polarizer pressure-sensitive adhesive composition, a cation, which is a counter ion of an anion, is coordinated to an oxygen atom of ether in a plasticizer to form a complex.
A solution of a plasticizer in which a salt provided with an anion having a fluoro group and a sulfonyl group is dissolved in a pressure-sensitive adhesive composition for a polarizer, while developing an antistatic property in combination with the plasticity of the plasticizer. Add plasticity. In addition, a plasticizer containing a polyether group in the main chain can be close to the solubility parameter (SP value) of the pressure-sensitive adhesive composition for a polarizer, so it has excellent affinity and does not bleed. As a result, it is possible to obtain a pressure-sensitive adhesive composition for a polarizer, which is excellent in quick-acting property and sustained in excellent antistatic property, without occurrence of migration contamination and without depending on humidity. The above effects are the same as in the polyether ester plasticizer and the polyether plasticizer.

  A solution of a plasticizer in which a salt provided with an anion having a fluoro group and a sulfonyl group is dissolved exhibits antistatic properties while maintaining adhesive physical properties in the pressure-sensitive adhesive composition for a polarizer. Furthermore, since the solution of the plasticizer in which the salt having the anion having a fluoro group and a sulfonyl group is dissolved is excellent in compatibility with the molecules constituting the pressure-sensitive adhesive composition for a polarizer, bleeding, blooming and migration contamination are It is possible to obtain a pressure-sensitive adhesive composition for a polarizer which is excellent in quick-acting property and sustained in excellent antistatic property without depending on humidity and not depending on humidity.

  The anion having a fluoro group and a sulfonyl group is preferably an anion selected from the group consisting of a bis (fluoroalkylsulfonyl) imide ion, a tris (fluoroalkylsulfonyl) methide ion and a fluoroalkylsulfonic acid ion.

  The salt provided with the anion having a fluoro group and a sulfonyl group is composed of at least one cation selected from an alkali metal, a group 2 element, a transition metal and an amphoteric metal, and an anion having the above fluoro group and a sulfonyl group. It is preferable that it is a salt of Further, salts provided with anions having a fluoro group and a sulfonyl group are, in particular, alkali metal salts of bis (fluoroalkylsulfonyl) imide ions, alkali metal salts of tris (fluoroalkylsulfonyl) methide ions and alkali metal salts of fluoroalkylsulfonic acid ions Is preferred. Lithium salts are particularly preferred.

There are many salts composed of the above anions and cations, but among them, bis (fluoroalkylsulfonyl) imide ion, tris (fluoroalkylsulfonyl) methide ion, and fluoroalkylsulfonate ion are preferable, and bis (fluoroalkylsulfonyl) ion is preferable. It is preferable that it is a salt selected from the group consisting of an alkali metal salt of alkylsulfonyl) imide, an alkali metal salt of tris (fluoroalkylsulfonyl) methide and an alkali metal salt of trifluoroalkylsulfonic acid. Specifically, bis (trifluoromethanesulfonyl) imide lithium Li (CF ₃ SO ₂ ) ₂ N, bis (trifluoromethanesulfonyl) imidolipotassium K (CF ₃ SO ₂ ) ₂ N, bis (trifluoromethanesulfonyl) imide sodium _{Na (CF 3 SO 2) 2} N, tris (trifluoromethanesulfonyl) Mechidorichiumu _{Li (CF 3 SO 2) 3} C, tris (trifluoromethanesulfonyl) Mechidokariumu _{K (CF 3 SO 2) 3} C, tris (trifluoromethanesulfonyl) methide sodium _{Na (CF 3 SO 2) 3} C, lithium trifluoromethanesulfonate _Li (CF 3 _SO 3), potassium trifluoromethanesulfonate _K (CF 3 _SO 3), sodium trifluoromethanesulfonate Na (C ₃ SO ₃₎ are preferred. Among these, lithium bis (trifluoromethanesulfonyl) imide, tris (trifluoromethanesulfonyl) methide lithium, and lithium trifluoromethanesulfonate are mentioned. In particular, lithium bis (trifluoromethanesulfonyl) imide and lithium trifluoromethanesulfonate are preferable, and the above effect is further exhibited by adding a small amount of them.

  As shown in FIG. 1, lithium bis (trifluoromethanesulfonyl) imide lithium as a salt is dissolved in a polyether ester plasticizer consisting of diethylene glycol and adipic acid as lithium ion at the ether oxygen atom in polyethylene glycol. Is in a coordinated state. When a pressure-sensitive adhesive layer is formed using a pressure-sensitive adhesive composition for a polarizer, a pressure-sensitive adhesive layer in which lithium ions are uniformly dispersed is formed in a state where lithium ions are coordinated to ether oxygen atoms. And, in the adhesive layer, lithium ions are in a state of being easily moved by molecular motion of ether oxygen. When an external electric field is applied thereto, lithium ions move (ion transport) toward the corresponding poles in the adhesive layer to exhibit ion conductivity.

The state dissolved in tetraethylene glycol dimethyl ether using bis (fluoroalkylsulfonyl) imide lithium Li (CF ₃ SO ₂ ) ₂ N means that an ether group which is a polar group is coordinated to a Li ⁺ ion. It is dispersed in the composition in this state. That is, the composition contains a lithium polyether complex. The Li ⁺ ion is surrounded by ether oxygen, is separated from the (CF ₃ SO ₂ ) ₂ N ⁻ ion, is in a naked state, and greatly contributes to the antistatic property. In particular, a mixture of a plasticizer containing a lithium salt and a polyether group in the main chain forms a complex ion of Lewis acid / base type, and this complex behaves as a kind of ionic liquid, particularly contributing greatly to the antistatic property. Do. Further, since the lithium salt forms a Lewis acid / base complex ion with a plasticizer containing a polyether group in the main chain, it can not form a chemical bond with the iodine ion of the polarizer. Therefore, it does not cause color loss of the polarizer.

  The salt provided with the anion having a fluoro group and a sulfonyl group is preferably contained in an amount of 0.1 to 200 parts by mass, relative to 100 parts by mass of the plasticizer containing the above-mentioned polyether group in the main chain, It is more preferable to be contained by mass, and it is further preferable to be contained by 5 to 150 parts by mass.

  It is preferable that the solution of the plasticizer which melt | dissolved the salt provided with the anion which has a fluoro group and a sulfonyl group is 0.01-30 mass parts with respect to 100 mass parts of (meth) acrylic copolymers. By setting the content of the plasticizer solution in which the salt provided with the anion having a fluoro group and a sulfonyl group is in the above range, sufficient antistatic performance can be exhibited.

(Polymer type antistatic agent)
The antistatic composition may further contain a polymeric antistatic agent. Polymeric antistatic agents can stabilize salts with anions. Also, since the salt with anions is dispersed in the state of being dissolved in the plasticizer containing polyether group in the main chain, this salt has an affinity to the plasticizer containing polyether group in the main chain It is believed that the polymer-type antistatic agent gathers where it exists and is stabilized by the affinity between the two. As such a polymer type antistatic agent, a polyether block polyolefin copolymer, a polyoxyalkylene copolymer, or an ethylene oxide-propylene oxide-allyl glycidyl copolymer may be mentioned.

  The polymer type antistatic agent is preferably contained in an amount of 0.1 to 65 parts by mass with respect to 100 parts by mass of the (meth) acrylic copolymer.

(Method for producing antistatic composition)
In the method for producing an antistatic composition used in the present invention, a cation which is a counter ion of an anion having a fluoro group and a sulfonyl group is distributed to the ether oxygen atom of a plasticizer containing a polyether group in its main chain. And the step of preparing the salt solution in a fixed state. In the step of preparing a salt solution, a plasticizer containing a polyether group in its main chain rapidly dissolves a salt having an anion having a fluoro group and a sulfonyl group while generating heat. In the present invention, the plasticizer containing a polyether group in the main chain is preferably a polyether ester plasticizer and / or a polyether plasticizer, and the salt solution contains fluoro group and the like. It is obtained by adding a salt provided with an anion having a sulfonyl group, stirring and the like.

(Adhesive composition)
The polarizer pressure-sensitive adhesive composition is preferably a pressure-sensitive adhesive composition whose main component has a carboxyl group. Here, when the acid value of the monomer used for the polymerization of the pressure-sensitive adhesive composition is measured according to JIS K 0070 (1992), the acid value is preferably 0.1 mg KOH / g or more, and 5 mg KOH / g It is more preferable that it is more than.

When measuring an acid value based on JIS K 0070 (1992), it measures, for example as follows.
About 2 g of a sample is precisely weighed in a 100-ml conical flask with a precision balance, and 10 ml of a mixed solvent of ethanol / diethyl ether = 1/1 (weight ratio) is added thereto for dissolution. Further, 1 to 3 drops of a phenolphthalein ethanol solution as an indicator are added to the container, and the mixture is sufficiently stirred until the sample becomes uniform. This is titrated with a 0.1 N potassium hydroxide-ethanol solution, and the end point of neutralization is taken as the end of the light pink color of the indicator for 30 seconds. The value obtained using the following formula (1) from the result is taken as the acid value of the sample.
Acid value (mg KOH / g) = [B x f x 5.611] / S (1)
In the formula (1), B is the used amount (ml) of 0.1 N potassium hydroxide-ethanol solution, f is a factor of 0.1 N potassium hydroxide-ethanol solution, and S is a value of the sample It is a collection amount (g).

(Acryl-based pressure-sensitive adhesive composition)
In the pressure-sensitive adhesive composition for a polarizer, the main component is preferably an acrylic pressure-sensitive adhesive composition. An acrylic adhesive composition contains what the (meth) acrylic copolymer was bridge | crosslinked by the crosslinking agent. Moreover, "main component" means that 50 mass% or more is contained with respect to the whole adhesive.

  The acrylic pressure-sensitive adhesive composition contains a (meth) acrylic copolymer (A) and a crosslinking agent (B). The "acrylic pressure-sensitive adhesive composition" is a compound having a (meth) acryloyl group. "(Meth) acryloyl group" indicates that it is an acryloyl group or a methacryloyl group.

  (Meth) acrylic copolymer (A) is (i) 60 to 99.99 mass% of (meth) acrylic acid ester monomer having an alkyl group having 1 to 18 carbon atoms, and (ii) radically polymerizable unsaturated group It is preferable that it is obtained by at least polymerizing 0.01 to 20% by mass of a monomer having at least one reactive functional group.

  (I) As a (meth) acrylic acid ester monomer (hereinafter referred to as non-crosslinkable acrylic monomer) having an alkyl group having 1 to 18 carbon atoms, for example, carbonization of a hydrogen atom of a carboxy group of (meth) acrylic acid The (meth) acrylic acid ester substituted by the hydrogen group is mentioned. 1-18 are preferable and, as for carbon number of this hydrocarbon group, 1-8 are more preferable. The hydrocarbon group may have a substituent. The substituent is not particularly limited as long as it does not contain a crosslinkable group, and examples thereof include an alkoxy group such as a methoxy group and an ethoxy group. Specific examples of the (meth) acrylic ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, Isobutyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n- (meth) acrylate Octyl, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-undecyl (meth) acrylate, (Meth) acrylic acid n-dodecyl, stearyl, methoxyethyl (meth) acrylate, (meth) acrylic acid Kishiechiru, cyclohexyl (meth) acrylate include benzyl (meth) acrylate. One of these may be used alone, or two or more may be used in combination. In the present invention, "(meth) acrylic acid" means that both "acrylic acid" and "methacrylic acid" are included. Among these, n-butyl acrylate, 2-ethylhexyl acrylate, and methyl acrylate are preferable in terms of adhesiveness.

  The amount of the non-crosslinkable acrylic monomer used for the polymerization of the (meth) acrylic copolymer (A) is preferably 60 to 99.99% by mass, and more preferably 65 to 99.9% by mass. If the amount of the non-crosslinkable acrylic monomer used for polymerization is more than the above lower limit value, sufficient adhesion can be developed, and if less than the above upper limit value, sufficient crosslinking can be achieved.

(Ii) A monomer having a radically polymerizable unsaturated group and having at least one reactive functional group (hereinafter referred to as a crosslinkable monomer) is acrylic if it is polymerizable with a non-crosslinkable acrylic monomer. It may be a monomer or non-acrylic monomer, and is preferably an acrylic monomer. As a reactive functional group, a carboxy group, a hydroxy group, an amino group, an epoxy group, a glycidyl group etc. are mentioned.
Examples of the carboxy group-containing monomer include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, grataconic acid, and anhydrides thereof. .
Examples of the hydroxy group-containing monomer include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, And (meth) acrylic acid [(mono, di or poly) alkylene glycol] such as acrylic acid mono (diethylene glycol) and (meth) acrylic acid lactone such as (meth) acrylic acid monocaprolactone.
Examples of the amino group-containing monomer include (meth) acrylamide, allylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide and the like.
As a glycidyl group containing monomer, glycidyl (meth) acrylate etc. are mentioned, for example.

Among these, from the viewpoint of improving heat resistance, carboxy group-containing monomers are preferable, and acrylic acid is particularly preferable. The amount of the carboxy group-containing monomer used for the polymerization of the (meth) acrylic copolymer (A) is 0.01 to 20 based on the total mass of the monomers used for the polymerization of the (meth) acrylic copolymer (A) % By mass is preferable, 0.05 to 10% by mass is more preferable, 0.1 to 10% by mass is more preferable, and 0.5 to 10% by mass is particularly preferable.
When the amount of the carboxy group-containing monomer used for the polymerization is 0.05% by mass or more, the heat resistance in a high temperature or high temperature high humidity environment or an environment in which heating and cooling are repeated is further improved. If the amount of the carboxy group-containing monomer is less than or equal to the above upper limit value, it is easy to control the adhesive strength, and the reworkability to re-peel and reuse glass is also good.

  In addition, it is also preferable to use a hydroxy group-containing monomer or an amino group-containing monomer for polymerization, from the viewpoint of good tackiness, crosslinkability, polymerizability and durability, and reworkability capable of re-removing and reusing glass. . The hydroxy group-containing monomer is more preferably hydroxyalkyl (meth) acrylate, particularly preferably 2-hydroxyethyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate. As the amino group-containing monomer, (meth) acrylamide, N, N-dimethyl (meth) acrylamide and N-butyl (meth) acrylamide are preferable.

  When there are a plurality of crosslinkable monomers used for the polymerization of the (meth) acrylic copolymer (A), the total amount thereof is preferably 0.01 to 20% by mass, and 0.03 to 10% by mass or more. Is more preferable, and 0.05 to 10% by mass is more preferable. If the amount of the crosslinkable monomer used for the polymerization is at least the above lower limit, crosslinking can be sufficiently achieved, and if it is at the above upper limit, adhesion is easy to control and reworkability to re-peel and reuse glass is also good.

The (meth) acrylic copolymer (A) may have a non-crosslinkable acrylic monomer and another monomer other than the crosslinkable monomer. Other monomers include (meth) acrylonitrile, vinyl acetate, styrene, vinyl chloride, vinyl pyrrolidone, vinyl pyridine and the like.
The amount of the other monomer used for polymerizing the (meth) acrylic copolymer (A) is preferably 0.1 to 20% by mass, and more preferably 0.5 to 10% by mass. If the amount of the other monomer used for polymerization is more than the above lower limit, the physical properties can be easily adjusted, and if less than the above upper limit, yellowing due to deterioration with time and the like can be prevented.

(Weight-average molecular weight of (meth) acrylic copolymer)
The weight average molecular weight of the (meth) acrylic copolymer (A) is preferably 400,000 to 2,500,000, more preferably 500,000 to 2,000,000, and still more preferably 1,000,000 to 2,000,000, It is particularly preferable that it is 1.5 million to 2 million. By making a weight average molecular weight into the said range, sufficient cohesion force can be exhibited and durability can be improved. Furthermore, the viscosity rise of the coating liquid containing the adhesive composition for polarizers can be suppressed, and it becomes easy to form an adhesive layer by coating. In addition, a weight average molecular weight can be measured using gel permeation chromatography (GPC), and is a weight average molecular weight converted into standard polystyrene (PS).

(Cross-linking agent used for acrylic pressure-sensitive adhesive composition)
As a crosslinking agent (B) used for an acrylic adhesive composition, it is preferable to use the crosslinking agent which can react with the crosslinkable monomer which is a monomer which has a reactive functional group. For example, an isocyanate type crosslinking agent, an epoxy type crosslinking agent, an oxazoline type crosslinking agent, an aziridine type crosslinking agent, a metal chelate type crosslinking agent, a butylated melamine type crosslinking agent and the like can be mentioned. Among these crosslinking agents, an isocyanate crosslinking agent, an epoxy crosslinking agent, and a metal chelate crosslinking agent are preferable since the (meth) acrylic copolymer (A) can be easily crosslinked. In particular, when the (meth) acrylic copolymer (A) contains only a hydroxy group-containing monomer as the crosslinkable monomer, it is preferable to use an isocyanate-based crosslinking agent in view of the reactivity of the hydroxy group.

  As an isocyanate type crosslinking agent, tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate etc. are mentioned, for example. As an epoxy type crosslinking agent, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexane Diol diglycidyl ether, tetraglycidyl xylene diamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexanone, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether Etc. The content of the crosslinking agent is preferably selected appropriately in accordance with the desired adhesive physical properties. Moreover, these crosslinking agents can be used individually or in 2 or more types.

  0.001-10 mass parts are preferable with respect to 100 mass parts of (meth) acrylic copolymers (A), and, as for content of the crosslinking agent (B) used for an acrylic adhesive composition, 0.01-5 are preferable. The parts by mass are more preferred. Foaming can be suppressed if it is more than the said lower limit, and sufficient stress relaxation performance can be given if it is less than the said upper limit.

(Additive)
The pressure-sensitive adhesive composition for a polarizer of the present invention may contain components other than the acrylic pressure-sensitive adhesive composition and the antistatic composition. For example, in addition to the acrylic pressure-sensitive adhesive composition, a polyester resin, an amino resin, an epoxy resin, or a polyurethane resin may be used in combination.

In the pressure-sensitive adhesive composition for a polarizer of the present invention, if necessary, a light stabilizer such as an antioxidant, a metal corrosion inhibitor, a tackifier, a silane coupling agent, an ultraviolet light absorber, a hindered amine compound, Additives such as fillers may be included. Examples of the antioxidant include phenol based antioxidants, amine based antioxidants, lactone based antioxidants, phosphorus based antioxidants, sulfur based antioxidants and the like. One of these antioxidants may be used alone, or two or more thereof may be used in combination. As the metal corrosion inhibitor, benzotriazole-based resins are preferable in terms of the compatibility and the effect of the pressure-sensitive adhesive. Examples of tackifiers include rosin resins, terpene resins, terpene phenol resins, coumarone indene resins, styrene resins, xylene resins, phenol resins, petroleum resins and the like. As a silane coupling agent, a mercapto alkoxysilane compound (for example, a mercapto group substituted alkoxy oligomer etc.) etc. are mentioned, for example. As a ultraviolet absorber, a benzotriazole type compound, a benzophenone series compound, a triazine type compound etc. are mentioned, for example.
The content of these additives is usually preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, with respect to 100 parts by mass of the solid content of the pressure-sensitive adhesive composition for a polarizer. 1 to 3 parts by mass is particularly preferred.

(Method of producing pressure-sensitive adhesive composition for polarizer)
The pressure-sensitive adhesive composition for a polarizer is produced by dispersing a salt having an anion having a fluoro group and a sulfonyl group in a composition containing a tackifying resin such as an acrylic pressure-sensitive adhesive composition. The production method comprises the steps of preparing a salt solution obtained by dissolving a salt having a fluoro group and an anion having a sulfonyl group in a plasticizer containing a polyether group in the main chain, and a salt solution (first component And the adhesive resin (second component) to form a composition, and the step of kneading or blending the composition with the adhesive resin (second component). By kneading the first component and the second component, the salt solution is dispersed or dissolved in the form of fine droplets in the composition. Then, the salt is further kneaded or blended with the adhesive resin (second component) in a state in which the salt is dissolved in the composition, so that the salt is dispersed in a more homogeneous affinity to the adhesive resin (second component) Be done.

(Adhesive sheet for polarizers)
The pressure-sensitive adhesive composition for a polarizer of the present invention can be formed into a sheet to obtain a pressure-sensitive adhesive sheet for a polarizer. The pressure-sensitive adhesive sheet for a polarizer can be produced, for example, by dissolving a pressure-sensitive adhesive in a solvent and removing the solvent after coating. The coating method can be appropriately selected from a knife coater, a micro bar coater, an air knife coater, a reverse roll coater, a reverse gravure coater, a Vario gravure coater, a die coater, a curtain coater and the like. When the pressure-sensitive adhesive sheet of the present invention is used, the step of applying and drying the pressure-sensitive adhesive in the bonding step is not necessary, and the pressure-sensitive adhesive sheet for polarizers is laminated between the optical film and the object to be adhered It is simple because it can

(Thickness of adhesive sheet for polarizers)
The thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet for a polarizer of the present invention is preferably 100 μm or less, and more preferably 5 to 50 μm. If it is below the said upper limit, the stress relaxation performance of an adhesive layer can fully be expressed.

(Pressure-sensitive adhesive sheet with polarizer release sheet)
The pressure-sensitive adhesive sheet with a release sheet for a polarizer preferably has a structure in which a release film in which a release agent is provided on a substrate is provided on one side or both sides of the pressure-sensitive adhesive sheet. For example, in a double-sided pressure-sensitive adhesive sheet with a release sheet in which a release film is provided on both sides of the pressure-sensitive adhesive layer, the pressure-sensitive adhesive coating liquid is applied to the release layer surface of the first release film having a release agent layer After that, the first release film can be obtained by bonding and pressure-bonding the release layer surface of the second release film composed of release agent layers having different release forces to the pressure-sensitive adhesive layer. When the peeling force of the first peeling film and the second peeling film are close to each other, when peeling off the peeling film on the light peeling force side, there is a tear-off phenomenon in which the adhesive is lifted from the peeling film on the heavy peeling force side. Occur. Therefore, the peel force of the peel film on the heavy peel force side is preferably 0.05 N to 0.15 N, and the peel force of the peel film on the light peel force side is preferably 0.01 to 0.04 N.
At this time, if the difference between the peel strengths of the two peelable films can be maintained, the first peelable film may be bonded and pressure-bonded after the adhesive coating liquid is applied to the second peelable film first. . The shape of the pressure-sensitive adhesive sheet may be a sheet or may be rolled up in a roll.

(Polarizer)
The pressure-sensitive adhesive composition for a polarizer and the pressure-sensitive adhesive sheet for a polarizer of the present invention can be directly stuck (laminated) on a polarizer. The polarizing plate at the time of using the adhesive composition for polarizers of this invention, and an adhesive sheet is shown to Fig.2 (a). As shown in FIG. 2A, the pressure-sensitive adhesive sheet (pressure-sensitive adhesive composition layer for polarizer) 20 is directly attached to the polarizer 10. The pressure-sensitive adhesive sheet (pressure-sensitive adhesive composition layer for polarizer) 20 may be attached to both sides of the polarizer 10.
FIG. 2 (b) shows the configuration of a conventional polarizing plate. In the conventional polarizing plate, a polarizer is pinched | interposed with a protective film, and the adhesive sheet (adhesive layer) was stuck on the protective film. Although the pressure-sensitive adhesive composition for a polarizer and the pressure-sensitive adhesive sheet of the present invention can be applied to such a configuration, the effect of the present invention is exerted when directly applied to a polarizer as shown in FIG. can do.

  The pressure-sensitive adhesive composition for a polarizer and the pressure-sensitive adhesive sheet for a polarizer of the present invention are for bonding a polarizer and a member having a thickness of 100 μm, preferably 1 mm or more. Moreover, the pressure-sensitive adhesive composition for a polarizer and the pressure-sensitive adhesive sheet for a polarizer of the present invention are for bonding a polarizer and an optical member. A liquid crystal cell or a touch panel etc. can be mentioned as an optical member, The image display apparatus provided with the adhesive sheet of this invention can be produced.

  As a polarizer used for a polarizing plate, for example, a polyvinyl alcohol-based resin film or a polyvinyl alcohol-based resin described in JP-A-2012-159778, in which a dichroic dye is adsorbed and oriented, is used. The polyvinyl alcohol-type resin which comprises a polarizer is obtained by saponifying polyvinyl acetate type resin. Examples of polyvinyl acetate resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of other monomers copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group. The degree of saponification of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. This polyvinyl alcohol-based resin may be further modified, and, for example, polyvinyl formal modified with aldehydes, polyvinyl acetal or the like may also be used. The degree of polymerization of the polyvinyl alcohol resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

  What formed this polyvinyl alcohol-type resin into a film is used as a raw film of a polarizer. The method of forming the polyvinyl alcohol resin into a film is not particularly limited, and the film can be formed by a known method. Although the film thickness of the raw film made of polyvinyl alcohol resin is not particularly limited, it is, for example, about 1 to 150 μm. The film thickness is preferably 3 μm or more, in consideration of the ease of stretching and the like.

  In addition, the polarizer is a process of uniaxially stretching the polyvinyl alcohol resin film as described above or the polyvinyl alcohol resin described in JP 2012-159778, the polyvinyl alcohol resin or the film is dyed with a dichroic dye Through the step of adsorbing the dichroic dye, the step of treating the polyvinyl alcohol resin or film to which the dichroic dye is adsorbed with a boric acid aqueous solution, and the step of washing with water after the treatment with the boric acid aqueous solution, and finally It is manufactured by drying.

  The polarizing plate has a structure in which a transparent protective film is laminated on at least one of the polarizers manufactured as described above. As this transparent protective film, those formed of an appropriate transparent resin can be used. Specifically, it is preferable to use one made of a polymer which is excellent in transparency, uniform optical properties, mechanical strength, thermal stability and the like. As such a transparent resin film, for example, cellulose based films such as triacetyl cellulose and diacetyl cellulose, polyester based films such as polyethylene terephthalate, polyethylene isophthalate and polybutylene terephthalate, polymethyl (meth) acrylate and polyethyl (meth) acrylate Although acrylic resin films, polycarbonate films, polyethersulfone films, polysulfone films, polysulfone films, polyimide films, polyolefin films, polynorbornene films, and the like, can be used, but the present invention is not limited thereto.

  The features of the present invention will be more specifically described below with reference to examples and comparative examples. The materials, amounts used, proportions, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as limited by the specific examples shown below. In addition, unless otherwise indicated, "part" and "%" in an example are a "mass part" and "mass%", respectively.

(Production Example 1)
<Preparation of (meth) acrylic copolymer (A-1)>
80 parts of ethyl acetate is added to a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a stirrer and a thermometer, 71 parts of butyl acrylate as a monomer, 24 parts of methyl acrylate, 4 parts of 2-hydroxyethyl acrylate, acrylic One part of acid was charged, and the internal temperature was raised to 55 ° C. while containing nitrogen gas and oxygen-free. Thereafter, a total solution of 0.06 parts of azobisisobutyronitrile (polymerization initiator) dissolved in 10 parts of ethyl acetate was added. Then, it stirred, maintaining temperature, and after stirring for 12 hours, it cooled and the polymerization reaction was stopped. The obtained (meth) acrylic copolymer (A-1) had a polystyrene-reduced weight average molecular weight Mw of 1.51 million as measured by GPC.

(Measurement of weight average molecular weight of (meth) acrylic copolymer)
The weight average molecular weight Mw of the (meth) acrylic copolymer was measured by GPC (gel permeation chromatography) for a sample in which THF (tetrahydrafuran) was dissolved.

(Production Example 2)
<Preparation of (meth) acrylic copolymer (A-2)>
80 parts of ethyl acetate is added to a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a stirrer and a thermometer, 71 parts of butyl acrylate as a monomer, 24 parts of methyl acrylate, 4.93 parts of 2-hydroxyethyl acrylate Then, 0.07 parts of acrylic acid was charged, and the internal temperature was raised to 55 ° C. while containing nitrogen gas and oxygen-free. Thereafter, a total solution of 0.06 parts of azobisisobutyronitrile (polymerization initiator) dissolved in 10 parts of ethyl acetate was added. Then, it stirred, maintaining temperature, and after stirring for 12 hours, it cooled and the polymerization reaction was stopped. The obtained (meth) acrylic copolymer (A-2) had a polystyrene-reduced weight average molecular weight Mw by GPC of 1,500,000.

(Production Example 3)
<Preparation of (meth) acrylic copolymer (A-3)>
80 parts of ethyl acetate is added to a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a stirrer and a thermometer, 71 parts of butyl acrylate as a monomer, 24 parts of methyl acrylate, 4.85 parts of 2-hydroxyethyl acrylate The internal temperature was raised to 55 ° C. while charging 0.15 parts of acrylic acid and sealing in nitrogen gas to make it oxygen-free. Thereafter, a total solution of 0.06 parts of azobisisobutyronitrile (polymerization initiator) dissolved in 10 parts of ethyl acetate was added. Then, it stirred, maintaining temperature, and after stirring for 12 hours, it cooled and the polymerization reaction was stopped. The obtained (meth) acrylic copolymer (A-3) had a polystyrene-reduced weight average molecular weight Mw by GPC of 1,500,000.

(Measurement of weight average molecular weight of (meth) acrylic copolymer)
The weight average molecular weight Mw of the (meth) acrylic copolymer was measured by GPC (gel permeation chromatography) for a sample in which THF (tetrahydrafuran) was dissolved.

(Production Example 4)
<Preparation of (meth) acrylic copolymer (A-4)>
80 parts of ethyl acetate is added to a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a stirrer and a thermometer, 71 parts of butyl acrylate as a monomer, 24 parts of methyl acrylate, 4.93 parts of 2-hydroxyethyl acrylate Then, 0.07 parts of acrylic acid was charged, and the internal temperature was raised to 45 ° C. while containing nitrogen gas and oxygen-free. Thereafter, a total solution of 0.04 parts of azobisisobutyronitrile (polymerization initiator) dissolved in 10 parts of ethyl acetate was added. Then, it stirred, maintaining temperature, and after stirring for 16 hours, it cooled and the polymerization reaction was stopped. The obtained (meth) acrylic copolymer (A-4) had a polystyrene-reduced weight average molecular weight Mw by GPC of 1,800,000.

(Production Example 5)
<Production of Polarizing Plate>
A 75 μm thick polyvinyl alcohol film (average polymerization degree about 2,400, saponification degree 99.9 mol% or more) is uniaxially stretched about 5 times by dry stretching, and further kept at a tension of 60 ° C. After immersing in pure water for 1 minute, it was immersed in an aqueous solution of iodine / potassium iodide / water at a weight ratio of 0.05 / 5/100 at 28 ° C. for 60 seconds. Thereafter, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100 at 72 ° C. for 300 seconds. Subsequently, the film was washed with pure water at 26 ° C. for 20 seconds, and then dried at 65 ° C. to obtain a 28 μm-thick polarizer in which iodine is adsorbed and oriented to a polyvinyl alcohol film. Next, 3 parts of carboxyl group-modified polyvinyl alcohol [trade name "KL-318" obtained from Kuraray Co., Ltd.] was dissolved in 100 parts of water on one side of this polarizer, and water-soluble epoxy resin was dissolved in the aqueous solution. Coated with an epoxy-based adhesive containing 1.5 parts of a polyamide epoxy-based additive (trade name “Sumirez resin 650 (30)” obtained from Taoka Chemical Industry Co., Ltd., an aqueous solution with a solid content concentration of 30%). A 40 .mu.m thick triacetyl cellulose film (TAC) (trade name "KC4UY" manufactured by Konica Minolta Co., Ltd.) was laminated as a transparent protective film to prepare a polarizing plate.

Example 1
<Preparation of Acrylic Adhesive Solution>
0.1 part of xylylene diisocyanate (made by Mitsui Chemicals, Inc .: Takenate 500) as a crosslinking agent and 100 parts of the solid content of the (meth) acrylic copolymer (A-1) obtained in Production Example 1 0.1 part of glycidoxypropyl methoxysilane (Shin-Etsu Chemical Co., Ltd .: KBM-403) was added, and 50 parts of a polyetherester compound as an antistatic composition (Monocizer (registered trademark) W-262 and Polysizer) A mixture of 50 parts of bis (trifluoromethanesulfonyl) imide lithium dissolved in a 1: 1 mixture with (registered trademark) W-230-H) and 2.5 parts of a solution having a solid concentration of 15% with ethyl acetate It diluted so that it might become, and the acrylic adhesive solution was prepared.

<Production of adhesive sheet>
A 38 μm-thick polyethylene terephthalate film (separator film) (a release film manufactured by Oji F-TEX, Inc .: 38RL-07 (2)) provided with a release agent layer treated with a silicone-based release agent, the adhesive solution prepared as described above Apply uniformly on the surface with an applicator so that the coated amount after drying is 20 μm / m ² , dry for 3 minutes in an air circulating constant temperature oven at 100 ° C., and apply the pressure-sensitive adhesive layer on the surface of the separator film. It formed. Then, a 38 μm-thick separator film (manufactured by Oji F-TEX Co., Ltd .: 38RL-07 (L)) is attached to the surface of the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is a pair of separator films having a peeling force difference. The adhesive sheet provided with the structure of the interposed separator film / adhesive layer / separator film was obtained. The pressure-sensitive adhesive sheet was aged at 23 ° C. and 50% relative humidity for 7 days.

<Production of polarizing plate with pressure-sensitive adhesive layer>
The separator film provided with a release agent layer having a light release force of the pressure-sensitive adhesive sheet was peeled off, and the pressure-sensitive adhesive layer was directly transferred (adhered) to the polarizing layer side of the polarizer of the polarizing plate obtained in Production Example 5 A layered polarizing plate was produced.

(Example 2)
<Preparation of Acrylic Adhesive Solution>
An acrylic adhesive in the same manner as in Example 1 except that the (meth) acrylic copolymer (A-2) is used instead of the (meth) acrylic copolymer (A-1) used in Example 1. A solution was obtained.
<Production of adhesive sheet>
In the same manner as in Example 1, a pressure-sensitive adhesive sheet was produced.
<Production of polarizing plate with pressure-sensitive adhesive layer>
In the same manner as in Example 1, a polarizing plate with a pressure-sensitive adhesive layer was produced.

(Example 3)
<Preparation of Acrylic Adhesive Solution>
0.1 parts of xylylene diisocyanate (made by Mitsui Chemicals, Inc .: Takenate 500) as a crosslinking agent and 100 parts of solid content of the (meth) acrylic copolymer (A-4) obtained in Production Example 4 0.1 part of glycidoxypropyl methoxysilane (Shin-Etsu Chemical Co., Ltd .: KBM-403) was added, and 50 parts of a polyetherester compound as an antistatic composition (Monocizer (registered trademark) W-262 and Polysizer ( 1.8 parts of a composition in which 50 parts of bis (trifluoromethanesulfonyl) imide lithium is dissolved in a 1: 1 mixture with (registered trademark) W-230-H), and ethyl acetate is added to a solution with a solid concentration of 15%. The resulting solution was diluted to prepare an acrylic pressure-sensitive adhesive solution.
<Production of adhesive sheet>
In the same manner as in Example 1, a pressure-sensitive adhesive sheet was produced.
<Production of polarizing plate with pressure-sensitive adhesive layer>
In the same manner as in Example 1, a polarizing plate with a pressure-sensitive adhesive layer was produced.

(Example 11)
<Preparation of Acrylic Adhesive Solution>
0.1 part of xylylene diisocyanate (made by Mitsui Chemicals, Inc .: Takenate 500) as a crosslinking agent and 100 parts of the solid content of the (meth) acrylic copolymer (A-1) obtained in Production Example 1 0.1 part of glycidoxypropyl methoxysilane (Shin-Etsu Chemical Co., Ltd .: KBM-403) was added, and bis (trifluoromethanesulfonyl) was added to 50 parts of a polyalkylene glycol (di / mono) alkyl ether compound as an antistatic composition. 2. 2.5 parts of a composition in which 50 parts of imide lithium was dissolved was diluted with ethyl acetate so as to be a solution having a solid concentration of 15% to prepare an acrylic pressure-sensitive adhesive solution.

<Production of adhesive sheet>
A 38 μm-thick polyethylene terephthalate film (separator film) (a release film manufactured by Oji F-TEX, Inc .: 38RL-07 (2)) provided with a release agent layer treated with a silicone-based release agent, the adhesive solution prepared as described above Apply uniformly on the surface with an applicator so that the coated amount after drying is 20 μm / m ² , dry for 3 minutes in an air circulating constant temperature oven at 100 ° C., and apply the pressure-sensitive adhesive layer on the surface of the separator film. It formed. Then, a 38 μm-thick separator film (manufactured by Oji F-TEX Co., Ltd .: 38RL-07 (L)) is attached to the surface of the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is a pair of separator films having a peeling force difference. The adhesive sheet provided with the structure of the interposed separator film / adhesive layer / separator film was obtained. The pressure-sensitive adhesive sheet was aged at 23 ° C. and 50% relative humidity for 7 days.

<Production of polarizing plate with pressure-sensitive adhesive layer>
The separator film provided with a release agent layer having a light release force of the pressure-sensitive adhesive sheet was peeled off, and the pressure-sensitive adhesive layer was directly transferred (adhered) to the polarizing layer side of the polarizer of the polarizing plate obtained in Production Example 5 A layered polarizing plate was produced.

(Example 12)
<Preparation of Acrylic Adhesive Solution>
An acrylic adhesive in the same manner as in Example 11 except that the (meth) acrylic copolymer (A-2) was used instead of the (meth) acrylic copolymer (A-1) used in Example 11. A solution was obtained.
<Production of adhesive sheet>
In the same manner as in Example 11, a pressure-sensitive adhesive sheet was produced.
<Production of polarizing plate with pressure-sensitive adhesive layer>
In the same manner as in Example 11, a polarizing plate with a pressure-sensitive adhesive layer was produced.

(Example 13)
<Preparation of Acrylic Adhesive Solution>
0.1 parts of xylylene diisocyanate (made by Mitsui Chemicals, Inc .: Takenate 500) as a crosslinking agent and 100 parts of solid content of the (meth) acrylic copolymer (A-4) obtained in Production Example 4 0.1 part of glycidoxypropyl methoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM-403) was added, and bisbis (trifluoromethanesulfonyl) was added to 50 parts of a polyalkylene glycol (di / mono) alkyl ether compound as an antistatic composition. An acrylic pressure-sensitive adhesive solution was prepared by adding 1.8 parts of a composition in which 50 parts of imidolithium were dissolved, and diluting with ethyl acetate to a solution with a solid concentration of 15%.
<Production of adhesive sheet>
In the same manner as in Example 11, a pressure-sensitive adhesive sheet was produced.
<Production of polarizing plate with pressure-sensitive adhesive layer>
In the same manner as in Example 11, a polarizing plate with a pressure-sensitive adhesive layer was produced.

(Comparative example 1)
<Preparation of Acrylic Adhesive Solution>
Bis (trifluoromethanesulfonyl) imide lithium in 50 parts of the polyether ester compound used in Example 2 (1: 1 mixture of Monosizer (R) W-262 and Polysizer (R) W-230-H) An acrylic pressure-sensitive adhesive solution is prepared in the same manner as in Example 1 except that 1-decyl-3-methylimidazolium hexafluorophosphate (solid at 25 ° C.) is used as an ionic solid instead of the composition in which 50 parts is dissolved. I got
<Production of adhesive sheet>
In the same manner as in Example 1, a pressure-sensitive adhesive sheet was produced.
<Production of polarizing plate with pressure-sensitive adhesive layer>
In the same manner as in Example 1, a polarizing plate with a pressure-sensitive adhesive layer was produced.

(Reference Example 1)
<Preparation of Acrylic Adhesive Solution>
(Meth) acrylic copolymer (A-3) was used in place of the (meth) acrylic copolymer (A-1) used in Example 1, the polyetherester compound 50 used in Example 1 No composition in which 50 parts of bis (trifluoromethanesulfonyl) imide lithium was dissolved was added in 1 part (1: 1 mixture of Monosizer (R) W-262 and Polysizer (R) W-230-H) An acrylic pressure-sensitive adhesive solution was obtained in the same manner as in Example 1 except for the above.
<Production of adhesive sheet>
In the same manner as in Example 1, a pressure-sensitive adhesive sheet was produced.
<Production of polarizing plate with pressure-sensitive adhesive layer>
In the same manner as in Example 1, a polarizing plate with a pressure-sensitive adhesive layer was produced.

(Evaluation)
<Measurement of surface resistance>
After peeling off the separator film of the pressure-sensitive adhesive layer-attached polarizing plate cut into 100 mm × 100 mm, the surface resistance value (Ω / □) of the pressure-sensitive adhesive surface is measured with a resistance value measuring instrument (manufactured by Mitsubishi Chemical Corporation: Hiresta-UP, MCP-HT450) ) Was used.

<Evaluation of polarizing plate durability>
After peeling off the separator of the polarizing plate with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive surface was attached to one side of a non-alkali glass (manufactured by Corning: EAGLE XG) with a thickness of 0.7 mm to produce an optical laminate. Subsequently, the autoclave process of 50 degreeC and 0.5 MPa and 20 minutes was performed, the polarizing plate with an adhesive layer was completely stuck to glass, and the optical laminated body was produced. The optical laminate prepared above was treated in a constant temperature and humidity chamber at 85 ° C. (heat resistance test) for 500 hours, and the optical laminate after the test was visually observed.
(Evaluation criteria)
○: No change in appearance such as floating, peeling, or foaming was observed at all.
Fair: appearance changes such as floating, peeling, and firing slightly noticeable.
X: Remarkable change in appearance such as floating, peeling, or firing is observed.

<Evaluation of optical durability (transmission hue)>
After peeling off the separator of the polarizing plate with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive surface was attached to one side of a non-alkali glass (manufactured by Corning: EAGLE XG) with a thickness of 0.7 mm to produce an optical laminate. Subsequently, the autoclave process of 50 degreeC and 0.5 MPa and 20 minutes was performed, the polarizing plate with an adhesive layer was completely stuck to glass, and the optical laminated body was produced. The optical laminate prepared above is treated in a constant temperature and humidity chamber at 60 ° C., relative humidity 90% (moisture resistance test) initially, for 100 hours, for 240 hours and for 500 hours, and the transmission hues in each treatment time The b value was measured. For measurement, a spectral color difference meter (manufactured by Nippon Denshoku Co., Ltd .: SE6000) was used. Using this measured value, the change amount Δb value of the transmission hue before and after the test was calculated.
Δ b = measured value after test-initial value before test

<Evaluation of optical durability (780 nm transmittance)>
After peeling off the separator of the polarizing plate with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive surface was attached to one side of a non-alkali glass (manufactured by Corning: EAGLE XG) with a thickness of 0.7 mm to produce an optical laminate. Subsequently, the autoclave process of 50 degreeC and 0.5 MPa and 20 minutes was performed, the polarizing plate with an adhesive layer was completely stuck to glass, and the optical laminated body was produced. The optical laminate prepared above is treated in a constant temperature and humidity chamber at 60 ° C., relative humidity 90% (moisture resistance test) initially, for 100 hours, 240 hours and 500 hours, and 780 nm transmission for each treatment time The rate T⊥ was measured. A spectrophotometer (manufactured by Shimadzu Corporation: Solidspec-3700) was used for the measurement. Using this measured value, the amount of change ΔT⊥ of the 780 nm transmittance before and after the test was calculated.
ΔT ⊥ = (measured value after processing)-(initial value)

<Measurement of degree of polarization>
After peeling off the separator of the polarizing plate with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive surface was attached to one side of a non-alkali glass (manufactured by Corning: EAGLE XG) with a thickness of 0.7 mm to produce an optical laminate. Subsequently, the autoclave process of 50 degreeC and 0.5 MPa and 20 minutes was performed, the polarizing plate with an adhesive layer was completely stuck to glass, and the optical laminated body was produced. The optical laminate prepared above is treated at 60 ° C., relative humidity 90% (moisture heat resistance test) initially for 100 hours, and the polarization degree of the polarizing plate before and 100 hours after treatment is measured by a spectrophotometer (JASCO Manufacture: V-7100) was used to measure, and change amount ΔPy was calculated.
ΔPy = (measured value after processing)-(initial value)

<Confirmation of color change by visual observation>
After peeling off the separator of the polarizing plate with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive surface was attached to one side of a non-alkali glass (manufactured by Corning: EAGLE XG) with a thickness of 0.7 mm to produce an optical laminate. Subsequently, the autoclave process of 50 degreeC and 0.5 MPa and 20 minutes was performed, the polarizing plate with an adhesive layer was completely stuck to glass, and the optical laminated body was produced. The optical laminate prepared above was treated in a constant temperature and humidity chamber at 60 ° C. and a relative humidity of 90% (moisture resistance test) for 500 hours, and the presence or absence of a color change was visually confirmed.

<Analysis of antistatic composition in adhesive sheet (complex-derived peak detection)>
15 ml of acetonitrile was added to 0.2 g of the pressure-sensitive adhesive sheet prepared in Examples etc., and after ultrasonication for 30 minutes, it was allowed to stand for 1 day (pretreatment). The solution was concentrated to dryness, dissolved in 1 ml of acetonitrile, and filtered with a 0.45 μm filter to be used as a measurement sample, and HPLC (high performance liquid chromatography) analysis was performed. Waters system: Separations Module 2696 was used for HPLC (high performance liquid chromatography) analysis, and PhotodiodeArrayDetector 996 was used as a detector. In addition, the detailed conditions of HPLC analysis are as follows.
Column; X Bridge C18, column diameter 4.6 x 250 mm (manufactured by Waters)
Column temperature; 30 ° C
Mobile phase; acetonitrile / water flow rate; 0.8 mL / min.
Detection: 225 nm

  The above evaluation results are shown in Table 1.

As can be seen from Table 1, in the examples, it is understood that the optical durability is also excellent in addition to the polarizing plate durability. That is, in the example, even when the film is left in a high temperature and high humidity environment for a long time, the coloration is small and the light transmittance is high.
On the other hand, in the comparative example, the optical durability was inferior and the function as a polarizing plate was inferior.

  Further, FIG. 3 shows, from the top, the complex-containing antistatic composition, the extract of the antistatic composition-containing adhesive sheet obtained in the example, and the extract of the adhesive sheet not containing the antistatic composition (Reference Example It is a result of the HPLC (high performance liquid chromatography) analysis of 1). As shown in the chromatogram of the extract of the antistatic composition-containing pressure-sensitive adhesive sheet in the middle, a complex peak was detected at a retention time of 15.0 minutes from the extract of the adhesive composition-containing pressure-sensitive adhesive sheet.

1 Polarizing plate 10 Polarizer 12 Protective film 20 Pressure-sensitive adhesive sheet (pressure-sensitive adhesive composition layer for polarizer)

Claims (12)

A pressure-sensitive adhesive composition for a polarizer comprising the antistatic composition and the (meth) acrylic copolymer (A),
The antistatic composition comprises a polyether ester plasticizer containing a polyether group in its main chain, a composition in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved, and a polyether group. A composition in which a salt provided with an anion having a fluoro group and a sulfonyl group is dissolved in a polyether plasticizer contained in the main chain,
The polyether plasticizer includes a polyether plasticizer represented by the following formula (11):
The content of the antistatic composition is 0.1 to 2.5 parts by mass with respect to 100 parts by mass of the (meth) acrylic copolymer (A),
The (meth) acrylic copolymer (A) is a pressure-sensitive adhesive composition for a polarizer having a carboxy group ;
R ¹ (OCH ₂ CH ₂ ) _n OR ² (11)
In the formula, R ¹ represents an alkyl group having 1 to 12 carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. n represents an integer of 3 to 6; The pressure-sensitive adhesive composition for a polarizer according to claim 1 , wherein the polyether ester plasticizer comprises at least one polyether ester plasticizer represented by the following formula (1) or (2);
In formulas (1) and (2), m and n are each an integer, and R represents an alkyl group. The (meth) acrylic copolymer (A) is (i) 60 to 99.99 mass% of (meth) acrylic acid ester monomer having an alkyl group having 1 to 18 carbon atoms, and (ii) a radically polymerizable unsaturated group Obtained by at least polymerizing 0.01 to 20% by mass of a monomer having at least one reactive functional group, and
The pressure-sensitive adhesive composition for a polarizer according to claim 1 or 2 , wherein the monomer having a reactive functional group is a carboxy group-containing monomer. The proportion of the carboxy group-containing monomer used for the polymerization of the (meth) acrylic copolymer (A) is 0.05 with respect to the total mass of the monomers used for the polymerization of the (meth) acrylic copolymer (A) The pressure-sensitive adhesive composition for a polarizer according to claim 3 , which is 10% by mass. The polarizer pressure-sensitive adhesive composition further comprises a crosslinking agent (B),
The pressure-sensitive adhesive according to any one of claims 1 to 4 , wherein the crosslinking agent (B) is at least one selected from an isocyanate crosslinking agent, an epoxy crosslinking agent, and a metal chelate crosslinking agent. Composition. Anions having the fluoro group and the sulfonyl group, bis (fluoroalkyl sulfonyl) imide ion, tris claims 1-5 is (fluoroalkyl sulfonyl) Mechidoion and fluoroalkyl sulfonate anions selected from the group consisting of ions The pressure-sensitive adhesive composition for a polarizer according to any one of the items. The salt provided with the anion having a fluoro group and a sulfonyl group is at least one cation selected from an alkali metal, a group 2 element, a transition metal and an amphoteric metal, an anion having the fluoro group and a sulfonyl group, and The pressure-sensitive adhesive composition for a polarizer according to any one of claims 1 to 6 , which is a salt consisting of The salt provided with the anion having a fluoro group and a sulfonyl group is an alkali metal salt of bis (fluoroalkylsulfonyl) imide, an alkali metal salt of tris (fluoroalkylsulfonyl) methide and an alkali metal salt of trifluoroalkylsulfonic acid The pressure-sensitive adhesive composition for a polarizer according to any one of claims 1 to 7 , which is a salt selected from the group consisting of The pressure-sensitive adhesive composition for a polarizer according to any one of claims 1 to 8 , wherein the pressure-sensitive adhesive composition for a polarizer is for bonding a polarizer and an optical member. The pressure-sensitive adhesive composition for a polarizer according to claim 9 , wherein the optical member is a liquid crystal cell or a touch panel. A pressure-sensitive adhesive sheet for a polarizer, comprising the pressure-sensitive adhesive composition for a polarizer according to any one of claims 1 to 10 . An image display apparatus comprising at least one pressure-sensitive adhesive sheet according to claim 11 .