KR20130054314A - Curable resin composition for antistatic layer, optical film, polarizing plate, and display panel - Google Patents

Abstract

Provided is a curable resin composition for an antistatic layer capable of forming an antistatic layer having sufficient antistatic properties and good adhesion between adjacent HC layers, and an optical film having the antistatic layer. This invention has two or more photocurable groups in (A) antistatic agent and (B) 1 molecule, has 6 or more (meth) acryloyl groups in the molecular weight 900 or less polyfunctional monomer, and (C) 1 molecule, and It contains urethane acrylate with an average molecular weight of 1000-11000, and the ratio of the said (A) with respect to the total amount of the said (A), (B) and (C) is 1-30 mass%, The said (B) and (C) The ratio of the said (C) with respect to the total amount of) is 1-40 mass%, The curable resin composition for antistatic layers characterized by the above-mentioned. Moreover, this invention is an optical film in which the antistatic layer and hard coat layer of the film thickness of 1-5 micrometers which consist of hardened | cured material of the said curable resin composition for antistatic layers from the TAC base material side are provided in one surface side of a TAC base material.

Description

Curable resin composition for an antistatic layer, an optical film, a polarizing plate, and a display panel {CURABLE RESIN COMPOSITION FOR ANTISTATIC LAYER, OPTICAL FILM, POLARIZING PLATE, AND DISPLAY PANEL}

The present invention provides an optical film having an antistatic layer provided on a front surface of a display (image display device) such as a liquid crystal display (LCD), a cathode ray tube display device (CRT) or a plasma display (PDP), and a composition for an antistatic layer thereof. It relates to a polarizing plate and a display panel using the optical film.

In such a display, the optical film which consists of layers which have various functions, such as anti-reflective property, a hard coat property, an antistatic property, is generally provided in the outermost surface. In addition, in this specification, a hard coat may only be called "HC".

An antistatic layer for providing antistatic property is known as one of the functional layers of such an optical film. The antistatic layer is added to an antistatic agent such as conductive ultrafine particles of a metal oxide such as tin oxide (ATO) doped with antimony or indium oxide (ITO) doped with tin, a polymer conductive composition or a quaternary ammonium salt-based conductive material. It is formed by this (for example, patent document 1). When using these antistatic agents, in order to make desired antistatic property and optical characteristics (low haze and high total light transmittance) compatible, providing a desired function by forming the thin film layer of about 0.1-1 micrometer containing an antistatic agent was performed. .

In addition, in the display as described above, it is required to give hardness to the image display surface of the display so as not to be damaged during handling. On the other hand, in patent document 1, the structure of the optical film which provides an antistatic layer of a thin film on a triacetyl cellulose (hereinafter may only be called "TAC") base material, and provides an HC layer on the antistatic layer Is disclosed.

However, since the antistatic layer is a thin film, pentaerythritol triacrylate (hereinafter sometimes referred to simply as "PETA") and dipentaerythritol hexaacrylate (hereinafter sometimes referred to simply as "DPHA") contained in the layer and The amount of the same binder component and the antistatic agent is limited, and there is a problem that the adhesiveness of the HC layer adjacent to the antistatic layer is likely to be insufficient.

The optical film based on a base material / antistatic layer / HC layer has an interface between an antistatic layer and HC layer, and an interface between an antistatic layer and a base material, and there exists an adhesive problem in each interface.

At the interface between the antistatic layer and the HC layer, the reactive groups of the antistatic layer and the HC layer cross-link and adhere to each other, but at the same time, the antistatic layer is required to exhibit antistatic performance. In the case where the antistatic agent is a metal oxide, in order for the antistatic layer to exhibit antistatic performance, a large amount of antistatic agent is added because the fine particles of the antistatic agent need to be in close contact with each other, but the haze increases or the total light transmittance deteriorates. It may become. However, if the amount of the metal oxide is reduced by focusing on the optical characteristics, the antistatic performance becomes difficult to be exhibited. In addition, if the amount of the antistatic agent is increased, the amount of the binder component may be insufficient at the interface between the antistatic layer and the adjacent layer, resulting in poor adhesion between the antistatic layer and the adjacent layer. However, if the amount of metal oxide is reduced by focusing on adhesion, the antistatic performance becomes difficult to be exhibited.

In the case where the antistatic agent is a quaternary ammonium salt, the quaternary ammonium salt needs to be present in the layer in a larger amount than the binder in order to exhibit the antistatic performance. Or it is necessary to concentrate and exist in the vicinity of the interface adjacent to HC layer of an antistatic layer. However, in such a case, quaternary ammonium salts present in the vicinity of the interface inhibit the adhesion between the antistatic layer and the HC layer, and have a binder component (reactive group which increases the crosslinking density with the HC layer at the interface of the HC layer adjacent to the antistatic layer). The amount of components) may be insufficient, resulting in poor adhesion between the antistatic layer and the adjacent HC layer. However, if the amount of quaternary ammonium salt is reduced by focusing on adhesiveness, the antistatic performance is deteriorated.

In order to achieve both antistatic properties and adhesion, a simple method of increasing the amount of binder components such as PETA (pentaerythritol triacrylate) and DPHA (dipentaerythritol hexaacrylate) can be considered. The larger the thickness of the antistatic layer, the greater the curl (curvature) of the antistatic layer, and the higher the amount of expensive antistatic agent dispersed in the antistatic layer, resulting in increased cost. There is. Moreover, although the method of increasing the component which has a reactive group in a binder can be considered in order to improve adhesiveness, as mentioned above, since there exists the quantity of the antistatic agent required in order to express antistatic performance, there is a limitation in the quantity of a binder, This method is hard to adopt.

In addition, as described above, since the total amount of the binder component and the antistatic agent included in the layer of the antistatic layer, which is a thin film, is limited, the amount of the antistatic agent is reduced, and only the amount of the binder component is increased, thereby increasing the adhesion between the antistatic layer and the HC layer. Attempts have been made to reduce the amount of antistatic agent used, resulting in a decrease in antistatic performance.

On the other hand, in the interface between the antistatic layer and the base material, since the antistatic layer is in close contact with the base material, the binder component of the composition of the antistatic layer penetrates into the base material, and the binder component and the electric charge penetrated into the base material at the interface between the base material and the antistatic layer It is necessary for the binder component which forms a prevention layer to harden | cure bond.

In the case where the antistatic agent is a quaternary ammonium salt, it is conventionally known to use a large molecular weight for the purpose of improving durability and antistatic properties. However, if the molecular weight of the quaternary ammonium salt is large, since the binder component of the composition of the antistatic layer is difficult to penetrate into the substrate, in order to obtain adhesion between the antistatic layer and the substrate, the use of a large amount of a permeable solvent or a small molecular weight that can penetrate the substrate is small. The use of a binder was necessary. However, in that case, there exists a problem that the adhesiveness of the interface of an antistatic layer and HC layer worsens.

Moreover, although the technique which can prevent an interference fringe and improves appearance by using a permeable solvent is known conventionally, when a permeable solvent is used, a new interface may arise in a base material, and interference is added in addition to the above-mentioned deterioration of adhesiveness. There is a problem of deterioration in appearance by generating a pattern.

Japanese Patent Application Publication No. 2009-086660

This invention is made | formed in order to solve the said problem, The curable resin composition for antistatic layers which is excellent in an optical characteristic and an external appearance, and can form an antistatic layer with sufficient antistatic property and adhesiveness with the adjacent HC layer and a TAC base material. To provide a first object.

Moreover, a 2nd object of this invention is to provide the optical film excellent in anti-dust adhesion which has an antistatic layer formed using such a composition.

Moreover, this invention makes it a 3rd objective to provide the polarizing plate which has such an optical film.

Moreover, a 4th object of this invention is to provide the display panel which has such an optical film.

As a result of earnestly examining by the present inventors, it is a binder component contained in the composition of an antistatic layer, and it is a comparatively small molecular weight binder whose molecular weight is 900 or less, such as PETA and DPHA used in order to raise the crosslinking density with the adjacent HC layer, and to obtain adhesiveness. As a result, depending on the degree of penetration of the binder component in the depth direction from the surface that almost penetrates the TAC substrate or the interface with the HC layer of the TAC substrate to the back side without the HC layer, the binder component is the substrate. It will be understood that when localized therein, the binder component contained in the antistatic layer on the substrate is less and the components reacting at the interface between the HC layer and the antistatic layer are insufficient, so that the adhesion between the antistatic layer and the HC layer may not be sufficiently obtained. there was. In addition, if the portion penetrated inside the TAC substrate does not penetrate into the gradation, and all the penetrating materials penetrate into the TAC substrate to the same depth, a binder penetration layer is formed in the TAC substrate and a new interface is generated in the substrate. It turned out that appearance deteriorates, such as a pattern generate | occur | produce.

Therefore, the inventors of the present invention have sufficient effects by using a specific ratio of an antistatic agent included in the composition, a urethane acrylate having a specific molecular weight, which is a binder component that is difficult or does not penetrate into the TAC substrate, and a binder component (polyfunctional monomer) that penetrates into the TAC substrate. The present invention was completed by discovering that an antistatic layer having excellent antistatic property and excellent adhesion with an HC layer and a TAC substrate can be obtained, and an excellent dust adhesion preventing performance can be obtained as a whole of the optical film.

That is, the curable resin composition for antistatic layers which concerns on this invention which solves the said problem,

(A) antistatic agent,

(B) a polyfunctional monomer having two or more photocurable groups in one molecule and a molecular weight of 900 or less;

(C) a urethane acrylate having 6 or more acryloyl groups and / or methacryloyl groups in 1 molecule and having a weight average molecular weight of 1000 to 11000,

The ratio of the said (A) with respect to the total amount of the said (A), (B) and (C) is 1-30 mass%, Moreover

The ratio of the said (C) with respect to the total amount of the said (B) and (C) is 1-40 mass%, It is characterized by the above-mentioned.

By setting the ratio of the antistatic agent (A) to the above range, the antistatic layer having a thickness of 1 to 5 µm formed by using the composition has sufficient antistatic properties, and is sufficient even when the HC layer is laminated thereon to form an optical film. Dust adhesion prevention is ensured.

Conventionally, the film thickness of the antistatic layer has been provided with a thin film of about 0.1 to 1 μm in consideration of optical performance and transparency. However, in order to impart antistatic properties, most of the composition in the layer needs to be an antistatic material in order to provide antistatic properties. Since it existed, it was not possible to add sufficient quantity of the some binder which has a reactive group required in order to produce adhesiveness with a base material and the layer on it. Therefore, in this application, in order to make the film thickness thick to some extent and to make sure the adhesiveness of the layer adjacent to an antistatic layer, the binder component which has reactive groups other than an antistatic material was made to be added enough.

Furthermore, by setting the ratio of the urethane acrylate (C) to the total amount of the polyfunctional monomer (B) and the urethane acrylate (C) in the above range, an antistatic layer and an HC layer are formed on the TAC substrate in order from the TAC substrate side. Since the urethane acrylate (C) does not penetrate into the TAC base material or is more difficult to penetrate than the polyfunctional monomer (B), sufficient adhesion between the antistatic layer and the HC layer can be obtained by the urethane acrylate (C), and the polyfunctional Since monomer (B) permeates a TAC base material, the adhesiveness of an antistatic layer and a TAC base material can also be obtained.

Curable resin composition for antistatic layers which concerns on this invention WHEREIN: Since an antistatic agent (A) is a quaternary ammonium salt with a weight average molecular weight of 1000-50000, it suppresses penetration of an antistatic agent into the TAC base material, and is excellent in coating property. desirable.

In the curable resin composition for antistatic layers which concerns on this invention, what contains the (D) permeable solvent and the (E) non-invasive solvent can improve the action of a polyfunctional monomer (B) and urethane acrylate (C). It is preferable at that point.

In curable resin composition for antistatic layers which concerns on this invention, it is also possible to make the surface resistance value of the hardened | cured material of the film thickness of 1-5 micrometers of the said curable resin composition for antistatic layers into less than 1 * 10 <^{12> (} ohm) / square. When the hardened | cured material of the curable resin composition for antistatic layers, ie, an antistatic layer, makes such antistatic performance, the optical film which laminated | stacked the 5-15 micrometers hard-coat layer on an antistatic layer can exhibit dust prevention property.

Moreover, surface resistance value forms the hardened | cured material (antistatic layer) of the film thickness of 1-5 micrometers of the said curable resin composition for antistatic layers on a TAC base material, and makes the surface of the hardened | cured material high resistivity meter (Mitsubishi Chemical Analytec Co., Ltd.) Product name: Hirester IP MCP-HT260) means the value measured under conditions of humidity control for 24 hours by applied voltage 1000V, temperature 25 degreeC, and humidity 40%.

The optical film which concerns on this invention is an optical film in which the antistatic layer and the hard-coat layer of 1-5 micrometers of film thicknesses are provided adjacent to the triacetyl cellulose base material side on the one surface side of a triacetyl cellulose base material, The said antistatic layer is the said It consists of hardened | cured material of curable resin composition for antistatic layers, The said polyfunctional monomer (B) penetrates and hardens | cures in the area | region near the interface of the antistatic layer side of the said triacetyl cellulose base material, It is characterized by the above-mentioned.

The optical film according to the present invention, in which an antistatic layer having a thickness of 1 to 5 μm and an HC layer are provided on one surface side of the TAC substrate from the TAC substrate side, is sufficient as the antistatic layer is made of a cured product of the curable resin composition for an antistatic layer. Has dust adhesion prevention. Moreover, the adhesiveness of HC layer and antistatic layer becomes excellent. In addition, since the multifunctional monomer (B) is cured by penetrating into the region on the interface side of the antistatic layer side of the TAC substrate, adhesion between the antistatic layer and the TAC substrate can be obtained. Excellent dust adhesion performance can be obtained as a whole of the optical film.

In a preferable aspect of the optical film according to the present invention, the adhesion rate of the lattice adhesion test between the hard coat layer, the antistatic layer and the triacetyl cellulose substrate is 90 to 100%, and the temperature is 30 ° C and the humidity is 40%. It is also possible to make the said adhesion ratio 80-100% after irradiating an ultraviolet-ray for 192 hours by the light quantity of 500W / m <^2> per hour.

In addition, the adhesion rate of the lattice adhesion test is about the optical film after humidifying for 24 hours at the temperature of 25 degreeC, and 40% of humidity, according to the method of the lattice test of JIS K5400 at length and width | variety in a 1 mm space | interval on a hard-coat layer surface. 100 lattice patterns were made by inserting 11 gaps each, and Nitroban Co., Ltd. cello tape (registered trademark) was attached on the lattice pattern, and then it was quickly pulled in the direction of 90 ° and peeled off, based on the following criteria. It means the ratio of the grid pattern remaining without peeling calculated by.

Adhesion rate (%) = (number of unstretched plaids / total number of plaids 100) × 100

In the preferable aspect of the optical film which concerns on this invention, it is also possible to set it as the structure in which the low refractive index layer is further provided in the surface on the opposite side with the antistatic layer of a hard-coat layer.

In the preferable aspect of the optical film which concerns on this invention, it is also possible to make a hard-coat layer into the hardened | cured material of the composition containing an ionizing radiation curable resin.

The polarizing plate which concerns on this invention is provided with the polarizer in the triacetyl cellulose base material side of an optical film.

The display panel which concerns on this invention is characterized by the display arrange | positioned at the triacetyl cellulose base material side of an optical film.

TAC base material side on a TAC base material by hardening a composition containing an antistatic agent (A), a polyfunctional monomer (B), and a urethane acrylate (C) in the said specific ratio, and forming an antistatic layer with a film thickness of 1-5 micrometers. Even if it is a layer structure which has an antistatic layer and HC layer, sufficient dust adhesion prevention property can be obtained, and the optical film with favorable adhesiveness of an antistatic layer, a TAC base material, and HC layer can be obtained. Moreover, the composition containing this antistatic agent (A), a polyfunctional monomer (B), and urethane acrylate (C) in the said specific ratio can be suitably used also in forming the antistatic layer used for the optical film which has such a characteristic. Can be.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows an example of the laminated constitution of the optical film which concerns on this invention.
It is a schematic diagram which shows another example of the laminated constitution of the optical film which concerns on this invention.
It is a schematic diagram which shows an example of the laminated constitution of the polarizing plate which concerns on this invention.

Hereinafter, the curable resin composition for antistatic layers (Hereinafter, it may only be called "the composition for antistatic layers") concerning this invention, an optical film, and the polarizing plate and display panel using this optical film are demonstrated.

In the present invention, (meth) acryloyl represents acryloyl and / or methacryloyl, and (meth) acrylate represents acrylate and / or methacrylate.

The light of the present invention includes not only electromagnetic waves in the wavelengths of visible light, ultraviolet rays, and invisible regions such as X-rays, but also particle beams such as electron beams and radiation or ionizing radiation which collectively refer to electromagnetic waves and particle beams.

In this invention, a "hard coat layer" means what shows hardness more than "H" by the pencil hardness test (4.9 N load) prescribed | regulated to JISK5600-5-4 (1999).

In addition, in the definition of film and sheet in JIS-K6900, the sheet is thin and generally refers to a flat product whose thickness is smaller than the length and width, and the film is extremely small compared to the length and width, and the maximum thickness is arbitrary. A limited thin flat product, generally supplied in the form of a roll. Therefore, although the thickness is particularly thin among the sheets, the boundary between the sheet and the film is unclear and it is difficult to clearly distinguish. Therefore, in the present invention, the film includes both thick and thin. It is defined as ".

In this invention, resin is a concept containing a polymer other than a monomer and an oligomer, and means the component used as a matrix of other functional layers, such as an antistatic layer and HC layer after hardening.

In this invention, when molecular weight has a molecular weight distribution, it means the weight average molecular weight which is polystyrene conversion value measured by the gel permeation chromatography (GPC) in THF solvent, and when it does not have molecular weight distribution, A compound means its molecular weight.

In this invention, the average particle diameter of microparticles | fine-particles means the value measured using the Microtrac particle size analyzer made by Nikki Corporation in the case of microparticles | fine-particles in a composition, In the case of microparticles | fine-particles in a cured film, It means the average value of ten particles observed by the transmission electron microscope (TEM) photograph of a cross section.

In the present invention, penetration refers to dissolving or swelling the TAC substrate.

In this invention, solid content means the component remove | excluding a solvent.

(Curable Resin Composition for Antistatic Layer)

Curable resin composition for antistatic layers which concerns on this invention,

(A) antistatic agent,

(B) a polyfunctional monomer having two or more photocurable groups in one molecule and having a molecular weight of 900 or less;

(C) has 6 or more (meth) acryloyl groups in 1 molecule, and contains urethane acrylate of the weight average molecular weights 1000-11000,

The ratio of the said (A) with respect to the total amount of the said (A), (B) and (C) is 1-30 mass%, Moreover

The ratio of the said (C) with respect to the total amount of the said (B) and (C) is 1-40 mass%, It is characterized by the above-mentioned.

By setting the ratio of the antistatic agent (A) in the above range, the antistatic layer can impart antistatic property, and sufficient dust adhesion prevention property is secured even when the HC layer is formed on the antistatic layer having a film thickness of 1 to 5 탆.

In addition, when the ratio of the urethane acrylate (C) to the total amount of the polyfunctional monomer (B) and the urethane acrylate (C) falls within the above range, an HC layer is formed on the TAC substrate from the TAC substrate side following the antistatic layer. Since urethane acrylate (C) does not penetrate into a TAC base material or is more difficult to penetrate than a polyfunctional monomer (B), urethane acrylate (C) exists also at the interface of an antistatic layer and HC layer, and urethane acrylate Sufficient adhesiveness of an antistatic layer and HC layer can be acquired by hardening | bonding the (meth) acryloyl group and reactive group in HC layer which (C) has.

In addition, the polyfunctional monomer (B) properly penetrates the TAC substrate (not uniformly the same depth, but has a gradation), and the reactive group of the penetrated polyfunctional monomer (B) present in the TAC substrate (photocurable group). ) And the reactive group of the polyfunctional monomer (B) present in the antistatic layer and the reactive group ((meth) acryloyl group) of the urethane acrylate (C) are cured and bonded to each other so that adhesion between the antistatic layer and the TAC substrate can also be obtained.

Hereinafter, the said antistatic agent (A), a polyfunctional monomer (B), and urethane acrylate (C) which are essential components of the composition for antistatic layers which concerns on this invention, and the other component which may be contained suitably as needed are demonstrated. do.

(A: antistatic agent)

The antistatic agent (A) imparts electroconductivity to an antistatic layer or an optical film that is a cured film of the composition for antistatic layer to prevent electric charge, and prevents dust and garbage from adhering or defects in the process due to electrification. It is a component having an action of imparting properties, that is, antistatic property.

As the antistatic agent (A), a conventionally known antistatic agent can be used, and is not particularly limited.

For example, cationic compounds such as quaternary ammonium salts described in Patent Document 1, anionic compounds such as sulfonic acid bases, amphoteric compounds such as amino acids, nonionic compounds such as aminoalcohols, organometallic compounds and metal chelate compounds, and Polymeric conductive compositions such as a compound obtained by polymerizing these compounds, a polymerizable compound, conductive ultrafine particles such as indium tin oxide (ITO) having an average primary particle diameter of 1 to 100 nm, and polyacetylene of an aliphatic conjugated system are mentioned.

In curable resin composition for antistatic layers which concerns on this invention, that antistatic agent (A) is a quaternary ammonium salt of the weight average molecular weights 1000-50000, suppresses penetration of the antistatic agent (A) to the TAC base material, and is coating property It is preferable at this excellent point. When the said upper limit is exceeded, the coating property of a composition will deteriorate, and when below the said minimum, an antistatic agent will bleed out easily at the interface with HC layer of an antistatic layer, and there exists a possibility that the adhesiveness of an antistatic layer and HC layer may deteriorate.

Conventionally, the film thickness of the antistatic layer has been provided with a thin film of about 0.1 to 1 μm in consideration of optical performance and transparency, but in such a thin film layer, it is necessary to make most of the composition in the layer an antistatic material in order to impart antistatic properties. Since it existed, it was very difficult to add a sufficient amount of the resin composition which has a reactive group required in order to give adhesiveness with a base material and the layer coming over it. Therefore, in this invention, in order to make thickness of 1-5 micrometers thicker than before, and to make sure the adhesiveness of the layer adjacent to an antistatic layer, the resin composition which has reactive groups other than an antistatic material is made to be fully added. . Since the film thickness increases, it is preferable to select a material having high transparency as the antistatic agent to be added. In this respect, an organic material having a higher transparency than an inorganic material is preferable, and a quaternary ammonium salt having very little coloring among organic materials is optimal. When a quaternary ammonium salt is used, it is also preferable at the point which can make the total light transmittance of the whole optical film 90% or more when a transparency base material is TAC. In addition, it is possible to set the haze value to 0.5% or less. The total light transmittance is in accordance with JIS # K7361 (1997), and the haze value can be measured by HM150 manufactured by Murakami Color Technology Research Institute according to JIS # K7136 (2000).

Moreover, it is preferable that this quaternary ammonium salt has a photocurable group from the point which can improve the adhesiveness of an antistatic layer and HC layer by crosslinking reaction with the binder component of HC layer. It is preferable that a photocurable group is a polymerizable unsaturated group, More preferably, it is an ionizing radiation curable unsaturated group. As the specific example, group which has ethylenically unsaturated bonds, such as a (meth) acryloyl group, a (meth) acryloyloxy group, a vinyl group, and an allyl group, an epoxy group, etc. are mentioned.

As a commercial item of the quaternary ammonium salt whose weight average molecular weights are 1000-50000, for example, the brand name H6100 by Mitsubishi Chemical Co., Ltd., and the brand name Unilazine AS-10 / M of Shin-Nakamura Chemical Co., Ltd., Unilazine AS -12 / M, Unresin AS-15 / M and Unresin ASH26.

In the composition for antistatic layer, antistatic agent (A) is contained 1-30 mass% with respect to the total amount of an antistatic agent (A), the polyfunctional monomer (B), and urethane acrylate (C) mentioned later.

If the ratio of the antistatic agent (A) is less than 1% by mass based on the total amount (A + B + C), sufficient antistatic performance cannot be obtained. Moreover, when the ratio of an antistatic agent (A) exceeds 30 mass% with respect to the said total amount (A + B + C), the ratio of the polyfunctional monomer (B) and urethane acrylate (C) in the composition for antistatic layers will be It decreases, and sufficient adhesiveness with the TAC base material and HC layer adjacent to the said layer of an antistatic layer is no longer obtained.

Although the ratio of an antistatic agent (A) is 1-30 mass% with respect to the said total amount (A + B + C), Preferably it is 5-20 mass%.

(B: polyfunctional monomer)

Polyfunctional monomer (B) is one of the binder components which harden | cure and become the matrix of an antistatic layer, and is a monomer of 900 or less molecular weight which has 2 or more of photocurable groups in 1 molecule. It is a component which contributes to the improvement of adhesiveness by improving the crosslinking density with the HC layer adjacent to an antistatic layer or an antistatic layer by having a small molecular weight and being polyfunctional. In addition, the polyfunctional monomer contributes to improving the adhesion between the antistatic layer and the TAC substrate by at least partially penetrating into the TAC substrate.

When the molecular weight of the polyfunctional monomer (B) exceeds 900, the permeability to the TAC base material decreases, and there exists a possibility that sufficient adhesiveness of an antistatic layer and a TAC base material may not be obtained.

Although the molecular weight of a polyfunctional monomer (B) should just be 900 or less, it permeates | transmits a polyfunctional monomer (B) to a TAC base material suitably, and highly compatible with the adhesiveness of antistatic layer and HC layer, and antistatic property (surface resistance value). From a viewpoint, it is preferable that it is 230 or more, and, as for the molecular weight of a polyfunctional monomer (B), it is more preferable that it is 290 or more. If the molecular weight is less than 230, the penetration of the polyfunctional monomer (B) into the TAC substrate is not suitable, and all may penetrate at the same depth and a new interface may occur, and the light reflected from the interface and the antistatic layer There is a fear that optical interference occurs between light reflected at the interface between the HC layer and the light reflected from the surface of the HC layer, resulting in an interference fringe and deteriorating appearance.

1 type (s) or 2 or more types can be used as a polyfunctional monomer (B).

Although two or more photocurable groups of a polyfunctional monomer (B) form a crosslinked structure, it is preferable to have three or more, and it is more preferable to have five or more. If it is three or more, sufficient adhesiveness of an antistatic layer, HC layer, and a TAC base material will become easy to be obtained. As a photocurable group, the thing similar to what was mentioned as an antistatic agent is mentioned.

Examples of the polyfunctional monomer (B) include pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane tri (meth) acrylate, and the like. Trimethylolpropane hexa (meth) acrylate and modified substances thereof.

Examples of the modified body include EO (ethylene oxide) modified body, PO (propylene oxide) modified body, CL (caprolactone) modified body, isocyanuric acid modified body, and the like.

In the said polyfunctional monomer, in terms of curing reactivity, the photocurable group is more preferably acryloyl group than methacryloyl group.

Especially as a polyfunctional monomer (B), dipentaerythritol pentaacrylate (DPPA) and dipentaerythritol hexaacrylate (DPHA) are used preferably.

In the composition for an antistatic layer according to the present invention, the polyfunctional monomer (B) satisfies the above-mentioned content ratio of the antistatic agent and is preferably at least 60% by weight based on the total amount of the polyfunctional monomer (B) and the urethane acrylate To 99% by mass. If it is less than 60 mass%, sufficient adhesiveness of an antistatic layer, HC layer, and a TAC base material cannot be obtained. Moreover, when it exceeds 99 mass%, the ratio of urethane acrylate (C) is small and sufficient adhesiveness of an antistatic layer and HC layer cannot be obtained.

(C: urethane acrylate)

Urethane acrylate (C) is one of binder components which harden | cure and become the matrix of an antistatic layer, has 6 or more (meth) acryloyl groups in 1 molecule, and has a weight average molecular weight of 1000-11000, Preferably it is 1000- 10000, more preferably 1000 to 5000.

When the weight average molecular weight is 1000 to 11000, the coating workability is good, it does not penetrate into the TAC base material or is more difficult to penetrate than the polyfunctional monomer (B), it is easy to control penetration, and exists reliably in the whole antistatic layer.

When the antistatic agent (A) is a quaternary ammonium salt, compatibility with the hydrophilic compound is good as a property of this compound. Therefore, if the binder in the antistatic layer is a compound having an OH group (PETA, PETTA® pentaerythritol tetraacrylate, DPPA® dipentaerythritol pentaacrylate, or the like), the antistatic agent may be dispersed in the entire layer so that antistatic property can be obtained. There will be no. Although DPHA does not contain OH group in the structural phase, in general, it is difficult to make 100% 6-functional in synthetic phase, and in fact, it is known that DPHA is actually a mixed compound with a 5- or 4-functional moiety, and a commercially available resin is OH. Since the group remains, the desired antistatic property could not be obtained.

It is urethane acrylate (C) which is hydrophobic resin which can control this dispersibility. The urethane acrylate (C) is present in the entire layer, so that when the antistatic agent (A) is a quaternary ammonium salt system, the antistatic agent is excessively dispersed in the layer or bleed out in the interface direction with HC. can do. It is easy to bleed out in the HC interface direction, as described above, since quaternary ammonium salts have good hydrophilicity, when the antistatic layer is laminated and cured, air is present on the surface and bleed out in response to moisture in the air. Because.

By having six or more (meth) acryloyl groups, the crosslinking density of the reactive group in the antistatic layer or the HC layer adjacent to the antistatic layer is increased to contribute to the improvement of the adhesion between the antistatic layer and the HC layer. Moreover, the reactive group of the polyfunctional monomer (B) of the antistatic layer which penetrated the TAC base material improves the crosslinking density of the reactive group of the (meth) acryloyl group of the urethane acrylate (C) and the polyfunctional monomer which exist in an antistatic layer. The urethane acrylate (C) also contributes to the improvement of adhesion between the antistatic layer and the TAC substrate. In view of the adhesiveness, the urethane acrylate (C) may not be added and the polyfunctional monomer (B) having a large number of reactive groups other than the antistatic agent (A) may be used, but as described above, the antistatic layer of the antistatic agent (A) In order to control the movement inside, urethane acrylate (C) which is hydrophobic and has a large number of reactive groups is essential in order not to be controlled only by the polyfunctional monomer (B) and to prevent the antistatic agent (A) from being dispersed.

Moreover, containing urethane acrylate (C) is effective also in suppressing curl (warpage) generation | occurrence | production.

When the weight average molecular weight of the urethane acrylate (C) is less than 1000, the urethane acrylate (C) easily penetrates into the TAC substrate, excessively penetrates into the TAC substrate, and the acryloyl group at the interface between the antistatic layer and the HC layer There is a fear that it will be difficult to obtain the adhesion between the antistatic layer and the HC layer by decreasing.

When the weight average molecular weight of a urethane acrylate (C) exceeds 11000, application | coating workability may deteriorate.

If urethane acrylate (C) has 6 or more (meth) acryloyl groups, other crosslinking reactive functional groups, such as an ionizing radiation curable unsaturated group, may be contained. The (meth) acryloyl group may have 6 or more of acryloyl group and methacryloyl group, may have only acryloyl group, and may have only methacryloyl group.

The urethane acrylate (C) of the present invention is not particularly limited as long as it has a urethane bond (-NH-CO-O-), has six or more (meth) acryloyl groups, and the weight average molecular weight. As the urethane acrylate (C), a light-transmissive one that transmits light when used as a coating film is preferable, and an ionizing radiation curable urethane acrylate which is a resin cured by ionizing radiation represented by ultraviolet rays or electron beams, and other known urethane acrylates. What is necessary is just to employ | adopt appropriately according to required performance etc.

As a commercial item of the said urethane acrylate, For example, the brand name UV1700B of the Nippon Synthetic Chemical Industry Co., Ltd. product described in patent document 1, the brand name UN3320HS of Negami Industrial Co., Ltd., the brand name BS577 of Arakawa Chemical Co., Ltd., and Shin The brand names U15HA, U15H, U9HA, U9H, U6HA, U6H, etc. by Nakamura Chemical Co., Ltd. are mentioned.

In the antistatic layer composition of the present invention, the urethane acrylate (C) satisfies the content ratio of the antistatic agent described above, and is 1 to 40 based on the total amount of the polyfunctional monomer (B) and the urethane acrylate (C). Mass%. If it is less than 1 mass%, sufficient adhesiveness of an antistatic layer and HC layer cannot be obtained. Moreover, when it exceeds 40 mass%, the ratio of a polyfunctional monomer (B) is small and sufficient adhesiveness of an antistatic layer and a TAC base material cannot be obtained.

Although the ratio of a urethane acrylate (C) is 1-40 mass% with respect to the said total amount (B + C), Preferably it is 5-30 mass%.

As such, when the ratio of the polyfunctional monomer (B) and the urethane acrylate (C) in the binder is appropriate, even if the antistatic agent (A) is excessively dispersed in the antistatic layer, antistatic properties can be exhibited in the layer without bleeding out. It can exist as many levels as possible. This composition enables the surface low efficiency of the antistatic layer to be less than 1 × 10 ¹² Ω / □.

The composition for antistatic layer may contain the solvent and the polymerization initiator suitably as needed other than the said (A), (B) and (C) component. Hereinafter, these other components are demonstrated.

(solvent)

Examples of the solvent include ketone solvents such as acetone described in Patent Document 1, ester solvents such as methyl acetate, nitrogen-containing solvents such as acetonitrile, glycol solvents such as methyl glycol, ether solvents such as THF, methylene chloride and the like. Permeable solvents such as halogenated hydrocarbon solvents and glycol ether solvents such as methyl cellosolve.

The permeable solvent is preferably at least one selected from the group consisting of methyl acetate, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone (MIBK) and cyclohexanone.

Moreover, you may use non-invasive solvents, such as propylene glycol monomethyl ether (PGME), normal propanol, isopropanol, normal butanol, sec-butanol, isobutanol, and tert-butanol.

The said solvent may be used individually by 1 type, and may mix and use 2 or more types.

In the antistatic layer composition of the present invention, the penetration of the polyfunctional monomer (B) into the TAC substrate is promoted by using a permeable solvent, and the permeable solvent is used because it is assumed that the adhesion between the antistatic layer and the TAC substrate is improved. It is desirable to.

Moreover, in the composition for antistatic layers of this invention, penetration of the said urethane acrylate (C) to the TAC base material is suppressed by using a non-invasive solvent, and since it is estimated that the adhesiveness of an antistatic layer and HC layer improves, It is preferable to use a permeable solvent.

Therefore, in the composition for antistatic layer of this invention, when a solvent is 1 type, it is preferable to use a penetration solvent, but when it is two or more types of solvents, it is most preferable to use a combination of a permeable solvent and a non-invasive solvent. . Although it is possible to control penetration by the molecular weight of urethane acrylate (C) even with one type (infiltration solvent only), it is easier to control penetration by using a combination of a permeable solvent and a non-invasive solvent. This is because performance can be obtained.

When a combination of a permeable solvent and a non-invasive solvent is used, the mass ratio is permeable solvent: non-invasive solvent = 100: 0 to preferably 90:10 to 50:50, and 100 parts by mass of the total solid of the antistatic layer composition. It is preferable that it is 30-500 mass parts with respect to.

(Polymerization initiator)

A polymerization initiator is a component which starts or promotes the crosslinking reaction of the said binder component (B), You may use suitably the conventionally well-known radical, cationic polymerization initiator, etc. as needed. As a radical polymerization initiator, the brand name Irgacure 184 (1-hydroxy cyclohexyl phenyl- ketone) by Chiba Japan Co., Ltd. is used preferably, for example. When using a polymerization initiator, it is preferable that the content is 0.4-2.0 mass% with respect to the total mass of the total solid of the composition for antistatic layers. Thus, by making the quantity of the polymerization initiator used for the composition for antistatic layers into the quantity of 1/10-1/2 of the polymerization initiator used by HC layer, many reactive groups of an antistatic layer can be left. As a result, the reaction is less likely to proceed, so that curling is prevented.

(Preparation of curable resin composition for antistatic layer)

The said curable resin composition for antistatic layers can be obtained by mixing-dispersing the said (A), (B) and (C) component in a solvent. In addition, when said (A), (B) or (C) component does not have a solvent and has sufficient fluidity, a solvent may not be present. Known methods such as a paint shaker or a bead mill can be used for the mixed dispersion.

In curable resin composition for antistatic layers which concerns on this invention, by making antistatic agent (A) into the range mentioned above, the surface resistance value of the hardened | cured material of the film thickness of 1-5 micrometers of the said curable resin composition for antistatic layers is 1 * 10 <^{12> (} ohm) It is also possible to make it less than / square. By the antistatic layer having such antistatic performance, even when the HC layer having a relatively thick film thickness is laminated, excellent dust adhesion prevention performance can be exhibited in the entire optical film.

When the film thickness of the antistatic layer is less than 1 μm, it is necessary to increase the amount of the quaternary ammonium salt, which is an antistatic agent, in order to maintain the equivalent surface resistance, but in this case, the reactive group of the antistatic agent decreases, so that the antistatic layer and the HC layer adhere closely. This may deteriorate.

When the film thickness of an antistatic layer exceeds 5 micrometers, surface resistance is easy to develop but there exists a possibility that a curl may generate | occur | produce and cost may rise and handling property may deteriorate.

Moreover, in the composition for antistatic layers, 5-20 mass% of antistatic agents (A) with respect to the total amount of an antistatic agent (A), a polyfunctional monomer (B), and a urethane acrylate (C), and also urethane acrylate (C ) To 5 to 30% by mass based on the total amount of the polyfunctional monomer (B) and the urethane acrylate (C), in addition to sufficient antistatic properties, excellent durability against adhesive ultraviolet (UV) adhesiveness of the optical film can also be obtained.

(Optical film)

The optical film which concerns on this invention is an optical film in which the antistatic layer and the hard-coat layer of 1-5 micrometers of film thicknesses are provided adjacent to the triacetyl cellulose base material side from the said triacetyl cellulose base material side, and the said antistatic layer is the said It consists of hardened | cured material of curable resin composition for antistatic layers, The said polyfunctional monomer (B) penetrates and hardens | cures in the area | region at the interface side of the said antistatic layer side of a triacetyl cellulose base material, It is characterized by the above-mentioned.

Even if the TAC base material is provided with an antistatic layer and an HC layer having a film thickness of 1 to 5 μm from one side of the TAC base material, the antistatic layer is formed of a cured product of the curable resin composition for an antistatic layer, thereby providing sufficient anti-dust adhesion. While having, the adhesiveness between the HC layer and the antistatic layer is excellent. In addition, since the multifunctional monomer (B) is cured by penetrating into the region on the interface side of the antistatic layer side of the TAC substrate, adhesion between the antistatic layer and the TAC substrate can be obtained. Excellent dust adhesion performance can be obtained as a whole of the optical film.

In the preferable aspect of the optical film which concerns on this invention, the antistatic layer is formed from the hardened | cured material of the composition for antistatic layers, and the lattice pattern adhesiveness between the said hard coat layer, the said antistatic layer, and the said triacetyl cellulose base material of an optical film When the adhesion ratio of the test is 90 to 100% and after 192 hours of irradiation with ultraviolet light at a light quantity of 500 W / m ² per hour at a temperature of 30 ° C. and a humidity of 40% (hereinafter, simply referred to as “after UV resistance test”). It is also possible to make the said adhesion ratio of the said) into 80-100%.

This adhesion rate indicates the adhesion between the HC layer, the antistatic layer and the TAC substrate, that is, the adhesion between the antistatic layer and the HC layer and the adhesion between the antistatic layer and the TAC substrate.

Antistatic agent (A), polyfunctional monomer (B), and a conventional binder even if urethane acrylate (C) is not included and a composition mainly containing only polyfunctional monomer (B) or urethane acrylate (C) is contained, and In the optical film which has an antistatic layer which consists of hardened | cured material of the composition in which urethane acrylate (C) is not contained in a specific ratio, adhesiveness between an antistatic layer and a TAC base material was good, but adhesiveness between an antistatic layer and HC layer was inadequate. As described above, when the adhesion between the antistatic layer and the HC layer is not sufficient, peeling does not occur between the antistatic layer and the TAC substrate when the adhesion test is performed, but peeling occurs and peels off between the antistatic layer and the HC layer. When the adhesion between the antistatic layer and the TAC substrate is insufficient, peeling occurs between the antistatic layer and the TAC substrate and peels off. Therefore, in order to obtain the outstanding adhesiveness as an optical film, the adhesiveness between an antistatic layer and HC layer and the adhesion between an antistatic layer and a TAC base material are needed.

By hardening the said antistatic layer composition and forming an antistatic layer, the adhesiveness between the antistatic layer and HC layer of 1-5 micrometers of film thickness is excellent, and the adhesiveness between an antistatic layer and a TAC base material is excellent, and the adhesiveness excellent in the whole optical film is expressed. In particular, this adhesiveness is remarkable after a UV test. The optical film which concerns on this invention expresses the outstanding adhesiveness also after UV test.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows an example of the laminated constitution of the optical film which concerns on this invention. The antistatic layer 20 and the hard-coat layer 30 are provided adjacent in this order on the one surface side of the triacetyl cellulose base material 10. It is a schematic diagram which shows another example of the laminated constitution of the optical film which concerns on this invention. The low refractive index layer 40 is further provided on the hard coat layer of the optical film similar to FIG.

Hereinafter, a triacetyl cellulose base material, an antistatic layer and a hard coat layer which are essential components of the optical film concerning this invention, and can be suitably installed as needed, A high refractive index layer, a medium refractive index layer, a low refractive index layer, an anti-glare layer, and a contamination Other layers, such as a prevention layer, are demonstrated.

(Triacetyl cellulose base)

The triacetyl cellulose base material used in the present invention is a triacetyl cellulose film having high light transmittance, and is not particularly limited as long as it satisfies the physical properties that can be used as the light transmissive base material of the optical film. The TAC base material of can be selected suitably and can be used.

The average light transmittance of the TAC substrate in the visible light region 380 to 780 nm is preferably 80% or more, particularly preferably 90% or more. In addition, the measurement of the light transmittance uses the value measured at room temperature and air | atmosphere using the ultraviolet-visible spectrophotometer (For example, brand name UV-3100PC by the Shimadzu Corporation make).

Surface treatment, such as providing a saponification process and a primer layer, may be given to the TAC base material. Moreover, additives, such as an antistatic agent, may be added.

The thickness of a TAC base material is not specifically limited, Usually, it is 30-200 micrometers, Preferably it is 40-200 micrometers.

(Antistatic layer)

The antistatic layer of this invention consists of hardened | cured material of the said curable resin composition for antistatic layers, and has a film thickness of 1-5 micrometers. If the film thickness is thinner than 1 µm, sufficient antistatic performance cannot be obtained, and a binder essential for securing adhesion with other layers cannot be sufficiently added. If it is thicker than 5 μm, the antistatic agent cannot exhibit performance unless it is present in a layer to some extent, so that the curl of the antistatic layer is increased, resulting in deterioration of workability, and when the film thickness is thick, the amount of the antistatic agent or the like contained is increased. This increases the cost.

As performance of an antistatic layer, it is preferable that surface resistance is less than 1x10 <^12> ohm / square, It is more preferable that it is 1x10 <^11> ohm / square or less, and 1x10 <^10> ohm / square or less. If surface resistance of an antistatic layer is favorable, the dust adhesion prevention property of the optical film which laminated | stacked HC layer will become more favorable.

(Hard coat layer)

A hard coat layer is a layer which shows the hardness more than "H" by the pencil hardness test (4.9N load) prescribed | regulated to JISK5600-5-4 (1999), and provides hardness to the optical film which concerns on this invention.

The HC layer may be made of a cured product of the composition for a hard coat layer, a conventionally known hard coat layer may be used, and may be made of a cured product of the composition for a hard coat layer containing only a binder component. The polymerization initiator etc. which were mentioned by the composition may be contained in the composition. For the purpose of increasing the hardness of the HC layer and the like, reactive silica fine particles having a crosslinking reactivity with a component which gives a known hardness, for example, the binder component described in JP-A-2008-165040, may be included. .

As a specific example, HC layer can be formed by apply | coating the resin composition containing ionizing radiation curable resin as a transparent resin to a transparent base material, and bridge | crosslinking and / or polymerizing the monomer, oligomer, and prepolymer contained in the said resin composition.

As transparent resin, ionizing radiation curable resin is preferable, As a functional group of a monomer, an oligomer, and a prepolymer, an ionizing radiation polymerizable functional group is preferable, and a photopolymerizable functional group is especially preferable. Sufficient adhesiveness of an antistatic layer and HC layer can be acquired by hardening | bonding this functional group with the reactive group of the urethane acrylate (C) in the antistatic layer resin composition.

As a photopolymerizable functional group, unsaturated polymerizable functional groups, such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group, etc. are mentioned.

Moreover, as a prepolymer and an oligomer, acrylates, such as urethane (meth) acrylate, polyester (meth) acrylate, and epoxy (meth) acrylate, unsaturated polyester, an epoxy resin, etc. are mentioned.

As a monomer, Styrene-type monomers, such as styrene and (alpha) -methylstyrene; Methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, pentaerythritol (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) Acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, glycerin propoxytriacrylic Latex, ditrimethylolpropane tetraacrylate, polyethylene glycol di (meth) acrylate, bisphenol F EO modified di (meth) acrylate, bisphenol A EO modified di (meth) acrylate, isocyanuric acid EO modified di (meth Acrylate, isocyanuric acid EO modified tri (meth) acrylate, polypropylene glycol di (meth) acrylate , Acrylic monomers such as trimethylolpropane PO-modified tri (meth) acrylate, trimethylolpropane EO-modified tri (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate; trimethylolpropane trithioglycolate, trimethylol And polyol compounds having two or more thiol groups in molecules such as propane trithiopropyrate and pentaerythritol tetrathioglycol, and urethane (meth) acrylates and polyester (meth) acrylates having two or more unsaturated bonds. .

In particular, it is preferable that it is a polyfunctional acrylate monomer from a viewpoint of raising crosslinking density and obtaining a wound prevention property, and especially a pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and dipentaerythritol hexa (meth) Since acrylate and dipentaerythritol penta (meth) acrylate have good adhesiveness with an antistatic layer, and pencil hardness is also good, it is more preferable. It is also preferable to mix oligomer components such as urethane polyfunctional acrylates with these monomers, because the hardness can be improved, and the polymerization shrinkage can be reduced to improve curling and cracking resistance.

In order to improve hardness, you may contain in such a resin composition inorganic fine particles, such as a silica. In addition, in order to improve compatibility with the resin composition, the organic surface treatment may be performed or may have a reactive group.

Moreover, it is also possible to add and use a polymer to the said resin composition as a binder. As a polymer, polymethyl methacrylate (PMMA), cellulose acetate propionate (CAP), etc. are mentioned, for example. By adding a polymer, the viscosity of the coating liquid can be adjusted, thereby making it easy to apply the coating.

Moreover, an optical radical polymerization initiator can be added to the said resin composition as needed. Preferable addition amount is 0.8-8.0 mass% with respect to the total mass of the total solid of the said resin composition. As the radical photopolymerization initiator, acetophenones, benzoin, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds and the like are used.

Acetophenones include 2,2-dimethoxy acetophenone, 2,2-diethoxy acetophenone, p-dimethyl acetophenone, 1-hydroxy-dimethyl phenyl ketone, 1-hydroxy-dimethyl-p-isopropyl phenyl ketone , 1-hydroxy cyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholino propiophenone, 2-benzyl-2-dimethylamine-1- (4-morpholino phenyl) -butanone And 4-phenoxy dichloro acetophenone, 4-t-butyl-dichloro acetophenone, and the like. Examples of benzoin include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl dimethyl ketal, Benzoin benzene sulfonic acid ester, benzoin toluene sulfonic acid ester, benzoin methyl ether, benzoin ethyl ether and the like.

As the benzophenones, benzophenone, hydroxy benzophenone, 4benzoyl-4'-methyldiphenyl sulfide, 2,4-dichloro benzophenone, 4,4-dichloro benzophenone and p-chloro benzophenone, 4,4 '-Dimethylamine benzophenone (Mikler ketone), 3,3', 4,4'-tetra (t-butylpaoxycarbonyl) benzophenone and the like can be used.

Moreover, a photosensitizer can also be mixed and used, and the n-butylamine, triethylamine, poly-n-butylphosphine etc. are mentioned as the specific example.

What is necessary is just to adjust the film thickness of HC layer suitably, for example, 1-20 micrometers. Preferably it is 5-15 micrometers. When it exceeds 15 micrometers, the outstanding dust adhesion prevention performance will not be acquired, and when it is less than 5 micrometers, hardness will become insufficient and adhesiveness will also become weak.

Usually, when HC layer laminated on an antistatic layer becomes thick, dust adhesion prevention performance will worsen, but if it is the structure and composition of this application, the outstanding dust adhesion prevention performance can be obtained.

In suitable embodiment of the optical film which concerns on this invention, even if a thick HC layer is laminated | stacked on an antistatic layer as antistatic layer is 1-5 micrometers and HC layer is 5-15 micrometers, an optical film has sufficient dust adhesion prevention performance, Sufficient adhesion between the antistatic layer and the HC layer can be obtained.

(Other layers)

In the optical film according to the present invention, a high refractive index for the purpose of improving the antireflection property, anti-glare property and antifouling property of the optical film on the surface on the side opposite to the antistatic layer of the HC layer within a range not departing from the gist of the present invention. You may provide other layers, such as a layer, a medium refractive index layer, a low refractive index layer, an anti-glare layer, and an antifouling layer.

(High refractive index layer and medium refractive index layer)

The high refractive index layer and the medium refractive index layer are layers provided for adjusting the reflectance of the optical film which concerns on this invention. When providing a high refractive index layer, although not shown, it is normally provided adjacent to the TAC base material side of a low refractive index layer. In addition, when providing a medium refractive index layer, although not shown in figure, it is normally provided in order of a medium refractive index layer, a high refractive index layer, and a low refractive index layer from a TAC base material side.

The high refractive index layer and the medium refractive index layer consist of the hardened | cured material of the composition mainly containing a binder component and the particle | grains for refractive index adjustment. As a binder component, the polyfunctional monomer etc. which were illustrated by the composition for antistatic layers can be used. As particle | grains for refractive index adjustment, the particle size whose particle diameter is 100 nm or less is mentioned, for example. Such fine particles include zinc oxide (refractive index: 1.90), titania (refractive index: 2.3 to 2.7), cerium oxide (refractive index: 1.95), tin dope indium oxide (refractive index: 1.95), antimony dope tin oxide (refractive index: 1.80), yttria (Refractive index: 1.87) and one or more types selected from the group consisting of zirconia (refractive index: 2.0).

Specifically, the high refractive index layer is preferably a refractive index of 1.50 to 2.80. The medium refractive index layer has a lower refractive index than the high refractive index layer, and preferably has a refractive index of 1.50 to 2.00.

What is necessary is just to adjust the film thickness of a high refractive index layer and a medium refractive index layer suitably, and it is preferable that it is 50-300 nm.

(Low refractive index layer)

The low refractive index layer is made of a cured product of a composition containing a low refractive index such as silica or magnesium fluoride and a binder component, or a composition for low refractive index layer containing a fluorine-containing resin such as vinylidene fluoride copolymer. The low refractive index layer can be used.

The composition for forming the low refractive index layer may contain hollow particles in order to reduce the refractive index of the low refractive index layer. Hollow particles refer to particles having an outer layer and surrounded by the outer layer with porous tissues or cavities. The porous structure or cavity contains air (refractive index: 1), and the refractive index of the low refractive index layer can be reduced by including hollow particles having a refractive index of 1.20 to 1.45 in the low refractive index layer. It is preferable that the average particle diameter of a hollow particle is 1-100 nm. As a hollow particle, what is used for the conventionally well-known low refractive index layer can be used, For example, the microparticle which has a space | gap as described in Unexamined-Japanese-Patent No. 2008-165040 is mentioned.

When the number average primary particle size of the fatty acid metal salt particles is less than the lower limit, problems such as aggregation of fatty acid metal salt particles or burial of fatty acid metal salt particles to colored resin particles are likely to occur, which adversely affects the printing performance of the toner. There is a case.

On the other hand, when the number average primary particle diameter of the said fatty acid metal salt particle exceeds the said upper limit, fatty acid metal salt particle will become easy to be released (released) from colored resin particle, and the function of a desired external additive (charge stability, fluidity, etc. to a toner) May not be sufficiently provided to the toner particles, which may adversely affect the printing performance of the toner.

(Antiglare layer)

An anti-glare layer consists of hardened | cured material of the composition for anti-glare layers containing a binder component and an anti-glare agent, The binder component can use the polyfunctional monomer etc. which were illustrated by the said antistatic layer composition.

As an anti-glare agent, microparticles | fine-particles are mentioned, For example, styrene beads (refractive index 1.59), melamine beads (refractive index 1.57), acrylic beads (refractive index 1.49), etc. are mentioned. It is preferable that the average particle diameter of the microparticles | fine-particles which provide such anti-glare property is 100-500 nm. It is preferable that content of the microparticles | fine-particles which provide anti-glare property is 2-30 mass% with respect to the total mass of the binder component contained in the composition for anti-glare layers.

(Pollution prevention layer)

According to a preferred embodiment of the present invention, a contamination preventing layer may be provided on the outermost surface of the optical film opposite to the TAC substrate for the purpose of preventing contamination of the outermost surface of the optical film. The antifouling layer makes it possible to achieve new improvement of antifouling and frictional damage to the optical film. The antifouling layer consists of a cured product of the antifouling layer composition containing an antifouling agent and a binder component.

As the binder component of the antifouling layer composition, a conventionally known one may be used, and for example, a polyfunctional monomer exemplified in the antistatic layer composition may be used.

The antifouling agent included in the antifouling layer composition may be appropriately selected from antifouling agents such as known leveling agents and may be used alone or in combination of two or more. It is preferable that content of an antifouling agent is 0.1-5 mass% with respect to the total mass of the binder component contained in the composition for antifouling layers.

(Method for producing optical film)

As a manufacturing method of the optical film of this invention, if it is a method which can obtain the layer structure of the above-mentioned optical film, it will not specifically limit, A conventionally well-known method can be used.

As an example, (i) the process of preparing a triacetyl cellulose base material, (ii) the process of preparing the said composition for antistatic layers and the composition for hard-coat layers, (iv) the said antistatic layer composition to one surface side of the said TAC base material The step of coating to form a coating film (i) the step of irradiating the coating film of the composition for antistatic layer with light and curing to form an antistatic layer and the step of applying the composition for hard coat layer on the antistatic layer to form a coating film. And (iii) irradiating and hardening the coating film of the said composition for HC layers, and forming a HC layer.

In addition, in the above (i) step, the coating film of the antistatic layer composition is semi-cured (half cure) without being completely cured (full cured), and the HC layer composition is applied onto the half cured coating film to form a coating film. The cured coating film and the coating film of the composition for HC layer may be combined and irradiated with light to obtain a full cured optical film. Thus, there exists an advantage that adhesiveness of an antistatic layer and HC layer becomes high by using a half cure method.

The coating method may be a conventionally known method, and is not particularly limited. The gravure coating method, the spin coating method, the dip coating method, the spray method, the slide coating method, the bar coating method, the roll coater method, the meniscus coater method, the platter Various methods, such as a flexographic printing method, the screen printing method, and a feed coat method, can be used.

Ultraviolet light, visible light, an electron beam, or ionizing radiation is mainly used for light irradiation. In the case of ultraviolet curing, ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, ultraviolet rays emitted from light rays such as carbon arcs, xenon arcs, and metal halide lamps are used. The irradiation amount of an energy source is 50-500 mJ / cm <^2> as an integrated exposure amount in an ultraviolet-ray wavelength 365nm. The irradiation amount in the case of half cure is 5-50mJ / cm <^2> . When heating in addition to light irradiation, it processes at the temperature of 40 degreeC-120 degreeC normally.

You may dry after application | coating of the composition for antistatic layers, before performing light irradiation. As a drying method, the method of combining vacuum drying, heat drying, and these drying etc. are mentioned, for example. In addition, when drying at normal pressure, it is preferable to dry at 30-110 degreeC. For example, when methyl ethyl ketone is used as the solvent of the composition for the antistatic layer, 20 seconds to 3 minutes at a temperature within the range of room temperature to 80 ° C, preferably 40 ° C to 70 ° C, preferably 30 seconds to 1 The drying process can be performed in minutes.

Compositions, such as HC layer and a low refractive index layer, may be prepared by the method similar to the said antistatic layer. In addition, when providing a low refractive index layer etc. on HC layer, the coating method and hardening method of the said antistatic layer can be used.

(Polarizer)

The polarizing plate which concerns on this invention is provided with the polarizer in the triacetyl cellulose base material side of the said optical film, It is characterized by the above-mentioned. It is a schematic diagram which shows an example of the laminated constitution of the polarizing plate which concerns on this invention. The polarizing plate 80 shown in FIG. 3 has the polarizer 70 in which the optical film 1, the protective film 50, and the polarizing layer 60 were laminated | stacked, and the triacetyl cellulose base material of the optical film 1 ( The polarizer 70 is provided on the 10) side.

The fact that the polarizer is disposed on the side of the triacetylcellulose substrate of the optical film includes not only the case where the optical film and the polarizer are separately formed but also the case where the member constituting the optical film also serves as a member constituting the polarizer .

Moreover, when using the polarizing plate which concerns on this invention for a display panel, a display panel is normally arrange | positioned at the polarizer side.

In addition, since the optical film mentioned above should be used about an optical film, the description here is abbreviate | omitted. Hereinafter, the other structure in the polarizing plate which concerns on this invention is demonstrated.

(Polarizer)

As a polarizer used for this invention, if it has a predetermined polarization characteristic, it will not specifically limit, Usually, the polarizer used for a liquid crystal display device can be used.

The form of a polarizer will not be specifically limited if it is a form which can hold | maintain predetermined polarization characteristic for a long time, For example, it may be comprised only with a polarizing layer, and the thing which a protective film and a polarizing layer were bonded may be sufficient as it. When the protective film and the polarizing layer are bonded, the protective film may be formed only on one side of the polarizing layer, or the protective film may be formed on both surfaces of the polarizing layer.

As a polarizing layer, the thing which formed the complex of polyvinyl alcohol and iodine is usually used by impregnating iodine in the film which consists of polyvinyl alcohol, and uniaxially stretching this.

Moreover, as a protective film, if the said polarizing layer can be protected and it has desired light transmittance, it will not specifically limit. As a light transmittance of a protective film, it is preferable that the transmittance | permeability in a visible light region is 80% or more, and it is more preferable that it is 90% or more. In addition, the transmittance | permeability of the said protective film can be measured by JISK7361-1 (test method of the total light transmittance of a plastics-transparent material).

As resin which comprises a protective film, a cellulose derivative, cycloolefin resin, polymethylmethacrylate, polyvinyl alcohol, polyimide, polyarylate, polyethylene terephthalate, etc. are mentioned, for example. Especially, it is preferable to use a cellulose derivative or cycloolefin resin.

The protective film may consist of a single layer or may be a laminate of a plurality of layers. In addition, when a protective film is what laminated | stacked several layers, the some layer of the same composition may be laminated | stacked, and the some layer which has a different composition may be laminated | stacked.

The thickness of the protective film is not particularly limited as long as the flexibility of the polarizing plate of the present invention can be within a desired range, and the dimensional change of the polarizer can be within a predetermined range by bonding with the polarizing layer. It is preferable to exist in the range of -200 micrometers, It is preferable to exist in the range of 15-150 micrometers especially, and it is preferable to exist in the range which is 30-100 micrometers further. When the said thickness is thinner than 5 micrometers, there exists a possibility that the dimensional change of the polarizing plate of this invention may become large. Moreover, when the said thickness is thicker than 200 micrometers, when cutting the polarizing plate of this invention, processing debris may increase, or a cutting knife may wear out quickly.

The protective film may have retardation. By using the protective film which has retardation, there exists an advantage that the polarizing plate of this invention can be made to have the viewing angle compensation function of a display panel.

It will not specifically limit, if the protective film is a form which can express desired retardation as a form which has retardation. As such an aspect, the protective film has a structure which consists of a single layer, for example, and contains refractive index anisotropy on the aspect which has retardation by containing the optical characteristic expression agent which expresses retardation, and the protective film which consists of resin mentioned above The form which has retardation is mentioned by having the structure which the retardation layer containing the compound which has is laminated | stacked. In this invention, any of these forms can be used suitably.

(Display panel)

The display panel which concerns on this invention is characterized by the display arrange | positioned at the triacetyl cellulose base material side of the said optical film.

Examples of the display include LCD, PDP, ELD (organic EL, inorganic EL), CRT, touch panel, electronic paper, tablet PC, and the like.

The display panel according to the present invention can also be used for touch panels, electronic paper, tablet PCs, and the like.

An LCD, which is a representative example of the display, is of a transmissive type, and includes a transmissive display and a light source device that irradiates it from the back side. When the said display is LCD, the said polarizing plate provided with the optical film of this invention or the said optical film is arrange | positioned on the surface of this transmissive display body.

The PDP which is another example of the said display is equipped with the surface glass substrate and the back glass substrate in which discharge gas was enclosed and arrange | positioned facing the said surface glass substrate. When the display is a PDP, the optical film may be provided on the surface of the surface glass substrate or its front plate (glass substrate or film substrate).

The display is formed by depositing a light-emitting body such as zinc sulfide or a diamine substance that emits light when a voltage is applied to a glass substrate, and converts an ELD device or an electrical signal that displays the voltage by controlling the voltage applied to the substrate to light, A display such as a CRT that generates a visible image may be used. In this case, the optical film is provided on the outermost surface of the ELD device or the CRT or the front face plate thereof.

(Example)

Hereinafter, the present invention will be described in more detail with reference to Examples. The present invention is not limited by these descriptions.

The composition 1 for antistatic layers and the composition 1 for HC layers which have the following compositions were prepared.

(Composition 1 for Antistatic Layer)

Antistatic agent (A): Brand name UV-ASHC-01 (weight average molecular weight 20000, solid content 70%, quaternary ammonium salt component 15% in solid content) of Nippon Chemical Co., Ltd .: 1 mass part in solid content conversion

Polyfunctional monomer (B): dipentaerythritol hexaacrylate (DPHA) (brand name: KAYARAD DPHA, Nihon Kayaku Co., Ltd. product, 6 functional, molecular weight 578): 64 mass parts

Urethane acrylate (C): Brand name BS577 (6 functional, weight average molecular weight 1000) by Arakawa Chemical Co., Ltd .: 35 parts by mass

Polymerization initiator: Brand name Irgacure 184 (1-hydroxycyclohexyl phenyl ketone) by Chiba Specialty Chemicals Co., Ltd .: 1 part by mass Methyl ethyl ketone: 100 parts by mass

(Composition 1 for HC layer)

Dipentaerythritol hexaacrylate (trade name: KAYARAD DPHA, manufactured by Nihon Kayaku Co., Ltd., 6 functional, molecular weight 578): 98 parts by mass

Polymerization initiator: Brand name Irgacure 184 (1-hydroxycyclohexylphenyl ketone) of Chiba Specialty Chemicals Co., Ltd .: 4 parts by mass Methyl ethyl ketone: 100 parts by mass

(Example 1)

A TAC base material (trade name TF80UL manufactured by Fujifilm Co., Ltd.) having a thickness of 80 μm was prepared, the composition 1 for antistatic layer prepared on one side of the TAC base material was applied, dried in a heat oven at a temperature of 70 ° C. for 60 seconds, and in a coating film The solvent was evaporated, the ultraviolet-ray was irradiated so that accumulated light amount might be 50mJ, and the coating film was hardened | cured, and the antistatic layer of thickness 2.5micrometer at the time of drying was formed.

Subsequently, the composition 1 for hard coat layer prepared on the obtained antistatic layer was applied, dried in the same manner as the antistatic layer, irradiated with ultraviolet rays so that the accumulated light amount was 150 mJ, the coating film was cured, and the hard coat layer having a thickness of 12 μm at the time of drying was applied. It formed and the optical film which has an antistatic layer and a hard-coat layer in order from one side of a TAC base material from a TAC base material side by this was produced.

Moreover, in order to measure the surface resistance value of an antistatic layer, the formation of the antistatic layer was performed on the TAC base material (TF80UL) similarly to the said optical film, and the laminated body which has only an antistatic layer in the one surface side of a TAC base material was also produced.

(Examples 2 to 7)

In Example 1, except having replaced the quantity or kind of the antistatic agent (A), the polyfunctional monomer (B), and the urethane acrylate (C) contained in the composition 1 for antistatic layers, respectively, as shown in Table 1, The optical film and the laminated body were produced similarly to Example 1. In addition, the urethane acrylate (C) used in Example 7 is brand name UV-7610B (made by the Japanese synthesis).

(Comparative Examples 1 and 2)

Example 1 WHEREIN: Except having replaced the quantity of the antistatic agent (A), polyfunctional monomer (B), and urethane acrylate (C) contained in the composition 1 for antistatic layers, as shown in Table 1, respectively, In the same manner as in 1, an optical film and a laminate were produced.

(Comparative Example 3)

In Example 1, the polyfunctional monomer (B) contained in the composition 1 for antistatic layer was used for the antistatic agent (A) using R128H (monofunctional, molecular weight 222) by Nihon Kayaku Co., Ltd. instead of DPHA. The optical film and the laminated body were produced like Example 1 except having replaced the quantity of the functional monomer (B) and urethane acrylate (C) as shown in Table 1, respectively.

(Comparative Example 4)

In Example 1, the polyfunctional monomer (B) contained in the composition 1 for antistatic layers was used antistatic agent (A), using DPCA60 (6-functional, molecular weight 1263) by Nihon Kayaku Co., Ltd. in place of DPHA. The optical film and the laminated body were produced like Example 1 except having replaced the quantity of the functional monomer (B) and urethane acrylate (C) as shown in Table 1, respectively.

(Comparative Example 5)

In Example 1, the urethane acrylate (C) contained in the composition 1 for antistatic layers was used instead of BS577, and was used for the antistatic agent (A) using EBECRYL270 (bifunctional, molecular weight 1500) by Daicel Cytec Co., Ltd., The optical film and the laminated body were produced like Example 1 except having replaced the quantity of the polyfunctional monomer (B) and urethane acrylate (C) as shown in Table 1, respectively.

(Comparative Example 6)

In Example 1, the urethane acrylate (C) contained in the composition 1 for antistatic layers was used instead of BS577, and was used for the antistatic agent (A) using EBECRYL5129 (6-functional, molecular weight 800) by Daicel Cytec Co., Ltd., The optical film and the laminated body were produced like Example 1 except having replaced the quantity of the polyfunctional monomer (B) and urethane acrylate (C) as shown in Table 1, respectively.

(Comparative Example 7)

In Example 1, the urethane acrylate (C) contained in the composition 1 for antistatic layer was used as BS371MLV (50 functional, molecular weight 20000) by Arakawa Chemical Industries, Ltd. instead of BS577, The optical film and the laminated body were produced like Example 1 except having replaced the quantity of the functional monomer (B) and urethane acrylate (C) as shown in Table 1, respectively.

(Comparative Examples 8 to 11)

Example 1 WHEREIN: Except having replaced the quantity of the antistatic agent (A), polyfunctional monomer (B), and urethane acrylate (C) contained in the composition 1 for antistatic layers, as shown in Table 1, respectively, In the same manner as in 1, an optical film and a laminate were produced.

(Reference Example 1)

In Example 6, the optical film and the laminated body were produced like Example 6 except having replaced the solvent contained in the composition 1 for antistatic layers only with the non-penetrating solvent.

(Comparative Example 12)

In Example 3, the urethane acrylate (C) included in the composition 1 for antistatic layer was replaced with caprolactone modified dipentaerythritol hexaacrylate (trade name: KAYARAD DPCA-60; manufactured by Nihon Kayaku Co., Ltd.). Other than the optical film and laminated body were produced similarly to Example 3. This compound tends to be hydrophilic for the same reasons as DPHA.

(Reference Example 2)

In Example 3, Example 3 except having replaced the antistatic agent (A) contained in the composition 1 for antistatic layers with the antistatic agent (B) (metal microparticles | fine-particles: ATO; brand name: ELCOM V3560; Nikki catalyst agent) An optical film and a laminated body were produced similarly.

(Reference Example 3)

In Reference Example 2, an optical film and a laminate were produced in the same manner as in Reference Example 2, except that the amount of the antistatic agent (B) contained in the composition 1 for the antistatic layer was increased as shown in Table 1.

(Evaluation of Surface Resistance of Antistatic Layer)

About the laminated body which laminated | stacked the antistatic layer on the base material of Examples 1-7, Comparative Examples 1-12, and Reference Examples 1-3, a high resistivity meter (trade name High Lester IP MCP- made by Mitsubishi Chemical Analytec Co., Ltd.) HT260), the surface resistance was measured at an applied voltage of 1000V. The results are shown in Table 1. In addition, unit ohm / square of the surface resistance value described in this application means ohm / sq. (Resistance per unit area).

(Evaluation of dust adhesion prevention of optical film)

The HC layer surface of the optical laminated body which consists of the base material / antistatic layer / hard coat layer which were produced by the Example and the comparative example was rubbed 20 round trips with the polyester cloth, and the rubbed surface was made to adjoin to the ash of a cigarette, and the dust adhesion prevention was based on the following reference | standard. Evaluated.

(Circle): There is no adhesion of ash, and there exists a dust adhesion prevention effect, and it is favorable.

X: There are many stickings of ash, and there is no dust sticking prevention effect.

(Evaluation of Adhesiveness of Optical Film)

About the optical films of Examples 1-7, Comparative Examples 1-12, and Reference Examples 1-3, after humidifying for 24 hours at the temperature of 25 degreeC, and 40% of humidity, it applied to the hard-coat layer surface according to the method of the grid pattern test of JISK5400. 100 grids are made by inserting 11 gaps each in length and width at 1mm intervals.Cellopape (registered trademark) manufactured by Nichiban Co., Ltd. is attached on the grid pattern, and then it is quickly pulled in the direction of 90 °. Peeling was carried out and the adhesion rate was computed based on the following criteria.

Adhesion rate (%) = (number of unstretched plaids / total number of plaids 100) × 100

In addition, about the optical films of Examples 1-7, Comparative Examples 1-12, and Reference Examples 1-3, after humidifying for 24 hours at the temperature of 25 degreeC and 40% of humidity, an ultraviolet-ray is emitted per hour at 30 degreeC and 40% of humidity. The adhesion rate after irradiating for 192 hours with the light quantity of 500W / m <^2> was also calculated | required. The measurement result of the adhesion rate of the optical film before and behind an UV test is put together in Table 1, and is shown.

(Summary of the result)

From Table 1, in Examples 1-7, the surface resistance value of the favorable laminated body (antistatic layer) was all obtained, and the adhesiveness of the optical film was also favorable. Moreover, the optical characteristic and the external appearance were also favorable.

However, in Comparative Examples 1 and 2, since the polyfunctional monomer (B) and the urethane acrylate (C) were not contained in the composition for the antistatic layer, the adhesion rate was good before the UV test, but the adhesion rate after the UV test was good. This was bad.

In Comparative Example 3, since the polyfunctional monomer (B) was monofunctional, sufficient adhesion rate could not be obtained.

In Comparative Example 4, the molecular weight of the polyfunctional monomer (B) was over 1000, the adhesion rate was low, and in particular, the adhesion rate after the UV resistance test was low. This is considered to be due to insufficient penetration of the polyfunctional monomer (B) into the TAC substrate and insufficient adhesion between the TAC substrate and the antistatic layer.

In Comparative Example 5, the number of functional groups of the urethane acrylate (C) was 2, the adhesion rate was low, and in particular, the adhesion rate after the UV resistance test was low. This is considered to be because the crosslinking by the urethane acrylate (C) is small and the adhesiveness of an antistatic layer and HC layer was inadequate.

In Comparative Example 6, the molecular weight of the urethane acrylate (C) was less than 1000, and the adhesion rate after the UV resistance test was particularly low. This is considered to be because the adhesion between the antistatic layer and the HC layer was insufficient because the urethane acrylate (C) penetrated the TAC base material excessively.

In the comparative example 7, the molecular weight of the urethane acrylate (C) exceeded 10000, and the adhesion rate was low, especially the adhesion rate after the UV resistance test was low. The surface resistance is also high, which is considered to be because the urethane acrylate (C) does not penetrate the TAC substrate at all and the relative amount of the antistatic agent (A) in the antistatic layer is reduced.

In Comparative Example 8, the content ratio of the antistatic agent (A) was small and the surface resistance value became high.

In Comparative Example 9, although the content ratio of the antistatic agent (A) was large and the antistatic property was good, the amount of the polyfunctional monomer (B) and the urethane acrylate (C) to be a binder decreased, so that the adhesion ratio was before and after the UV test. Low.

In the comparative example 10, since the content rate of the polyfunctional monomer (B) was large and the content rate of the urethane acrylate (C) was small, the adhesion rate was low, especially the adhesion rate after the UV resistance test was low.

In the comparative example 11, since the content rate of urethane acrylate (C) was large and the content rate of polyfunctional monomer (B) was small, the adhesion rate was favorable before the UV test, but the adhesion rate after the UV test was low.

In Reference Example 1, the adhesion rate was low and the surface resistance value was high. Since the solvent in the composition for an antistatic layer was made into only the penetrating solvent, it is considered that the urethane acrylate (C) did not sufficiently penetrate into the TAC base material, so that the relative amount of the antistatic agent (A) in the antistatic layer was reduced.

In the comparative example 12, since the urethane acrylate (C) which is hydrophobic resin was not used, the quaternary ammonium salt disperse | distributed too much and the surface resistance value was high. Therefore, dust adhesion prevention property was not acquired either.

In Reference Example 2, metal fine particles were used as the antistatic agent. Since it was set as the addition amount (quite little) of the level which can acquire the total light transmittance equivalent to the case of quaternary ammonium salt, the surface resistance value was bad.

In Reference Example 3, in order to obtain necessary antistatic properties without considering the total light transmittance, more metal fine particles were blended as Antistatic Agent than Reference Example 2, resulting in poor adhesiveness. Due to the large amount of addition, there was coloration, resulting in lower total light transmittance (88%) and higher haze (0.8%) than in the case of quaternary ammonium salts.

When the dust adhesion prevention property of the optical film of the Example, the comparative example, and the reference example was evaluated, when the surface resistance value of the laminated body was less than 1x10 <^{12> (} ohm) / square, all were favorable, but in other cases, many ashes adhered there was. That is, if it was an antistatic layer which has a preferable surface resistance value, even if HC layer was laminated | stacked on it, the dust adhesion prevention property could be provided to the optical film.

1, 2: optical film
10: triacetyl cellulose substrate
20: antistatic layer
30: hard coat layer
40: low refractive index layer
50: protective film
60: polarizing layer
70: polarizer
80: polarizer

Claims (11)

(A) antistatic agent,
(B) a polyfunctional monomer having two or more photocurable groups in one molecule and a molecular weight of 900 or less;
(C) a urethane acrylate having 6 or more acryloyl groups and / or methacryloyl groups in 1 molecule and having a weight average molecular weight of 1000 to 11000,
The ratio of the said (A) with respect to the total amount of the said (A), (B) and (C) is 1-30 mass%, Moreover
The ratio of the said (C) with respect to the total amount of the said (B) and (C) is 1-40 mass%, The curable resin composition for antistatic layers characterized by the above-mentioned. The method of claim 1,
Said (A) is quaternary ammonium salt of the weight average molecular weights 1000-50000, The curable resin composition for antistatic layers characterized by the above-mentioned. The method according to claim 1 or 2,
(D) The permeable solvent and the (E) non-invasive solvent, The curable resin composition for antistatic layers characterized by the above-mentioned. 4. The method according to any one of claims 1 to 3,
The curable resin composition for antistatic layers, whose surface resistance value of the hardened | cured material of the film thickness of 1-5 micrometers of the said curable resin composition for antistatic layers is less than 1x10 <^{12> (} ohm) / square. It is an optical film in which the antistatic layer and the hard-coat layer of the film thickness of 1-5 micrometers are adjoined from one side of the triacetyl cellulose base material from the said triacetyl cellulose base material side,
The said antistatic layer consists of hardened | cured material of the curable resin composition for antistatic layers of any one of Claims 1-4,
The said polyfunctional monomer (B) penetrates and hardens | cures in the area | region near the interface of the antistatic layer side of the said triacetyl cellulose base material, The optical film characterized by the above-mentioned. The method of claim 5,
Optical film which has dust adhesion prevention property. The method according to claim 5 or 6,
The adhesion rate of the lattice adhesion test between the hard coat layer, the antistatic layer and the triacetyl cellulose substrate was 90 to 100%, and the ultraviolet light was emitted at a light amount of 500 W / m ² per hour at a temperature of 30 ° C. and a humidity of 40%. The said adhesion rate after irradiating for 192 hours is 80 to 100%, The optical film characterized by the above-mentioned. 8. The method according to any one of claims 5 to 7,
The low refractive index layer is further provided in the surface on the opposite side to the antistatic layer of the said hard coat layer, The optical film characterized by the above-mentioned. 9. The method according to any one of claims 5 to 8,
The hard coat layer is a cured product of a composition containing an ionizing radiation curable resin. The polarizer is provided in the triacetyl cellulose base material side of the optical film in any one of Claims 5-9, The polarizing plate characterized by the above-mentioned. The display panel is arrange | positioned at the triacetyl cellulose base material side of the optical film in any one of Claims 5-9. The display panel characterized by the above-mentioned.

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