JP6536106B2 - Optical film, polarizing plate provided with the same, liquid crystal panel, image display device - Google Patents

Description

  The present invention relates to an optical film, a polarizing plate provided with the same, a liquid crystal panel, and an image display device.

  The image display surface of an image display device such as a liquid crystal display (LCD), a cathode ray tube display (CRT), a plasma display (PDP), an electroluminescence display (ELD), a field emission display (FED), electronic paper, a tablet PC An antistatic hard coat film may be provided to prevent adhesion of dust due to scratching of the image display surface and charging. As such an antistatic hard coat film, for example, one in which a resin composition containing a quaternary ammonium salt is coated on a transparent substrate film to form an antistatic hard coat layer has been proposed. (Patent Document 1).

  In the liquid crystal display, a polarizing plate is usually provided for the liquid crystal cell. The polarizing plate usually has a structure in which protective films are laminated on both sides of a polarizer made of a polyvinyl alcohol film in which iodine is adsorbed and oriented. In addition, a triacetylcellulose film is usually used as a protective film in terms of transparency, optical non-orientation, etc., and after the surface is saponified with an aqueous alkaline solution to enhance adhesion with a polarizer, it is polarized. It is stacked with a child.

JP, 2009-86660, A

  By the way, in the image display device, thinning is an important factor in performance, and in the case of an optical film incorporated in the image display device, it is desired to cope with thinning. For this reason, if an antistatic hard coat film is used as a protective film of a polarizing plate instead of additionally providing an antistatic hard coat film in addition to the polarizing plate, the thickness can be reduced accordingly. Here, the protective film to be laminated on the polarizer is required to be saponified with an aqueous alkaline solution as the adhesion improving treatment from the viewpoint of adhesion to the polarizer.

  However, when the antistatic hard coat film is subjected to a saponification treatment, the antistatic agent present on the surface of the antistatic hard coat layer may fall off, and as a result, the antistatic property and scratch resistance may be reduced. is there.

  In order to impart saponification resistance to the antistatic hard coat film, a protective film for saponification treatment is temporarily affixed on the antistatic hard coat layer, but there is a problem of cost increase. .

  The present invention has been made to solve the above problems. That is, it is an object of the present invention to provide an optical film which can maintain excellent antistatic property and scratch resistance in the antistatic hard coat layer even when saponification treatment is performed. Another object of the present invention is to provide a polarizing plate, a liquid crystal panel and an image display device using such an optical film.

According to one aspect of the present invention, there is provided an optical film comprising a light transmitting substrate and an antistatic hard coat layer provided on the light transmitting substrate, wherein the antistatic hard coat layer is provided. Has a thickness of 4 μm to 10 μm, and the antistatic hard coat layer contains an antistatic agent having a quaternary ammonium base and a weight average molecular weight of 1,000 to 30,000 and a binder resin, The antistatic agent is not present on the surface of the antistatic hard coat layer, and the depth from the surface of the antistatic hard coat layer in the antistatic hard coat layer is 0.2 μm or more. An optical film is provided, which is present in an area of less than 0 μm and is characterized in that the surface resistance value of the optical film is 1 × 10 ¹¹ Ω / □ or less.

  The antistatic hard coat layer comprises the antistatic agent, a photopolymerizable urethane oligomer having a weight average molecular weight of 1,000 or more and 70,000 or less, and an alkylene oxide group having four or more photopolymerizable functional groups. And a first acrylate monomer having a weight average molecular weight of 400 to 900 having four or more acryloyl groups, and a weight average molecular weight of 150 to less than 400 having an alkylene oxide group and two or more acryloyl groups. It is a cured product of a composition for antistatic hard coat layer containing a second acrylate monomer and a penetrating solvent, and the light transmitting substrate is near the interface with the antistatic hard coat layer. A light transmitting substrate, and the first acrylate monomer permeating the light transmitting substrate from the composition for the antistatic hard coat layer The cured product of the pre-permeate comprising said second acrylate monomer and may have a mixed region comprising a.

  The composition for antistatic hard coat layer may further contain a methacrylate monomer having a weight average molecular weight of 300 or more and 900 or less having two or more methacryloyl groups.

  The above-mentioned binder resin is composed of a first binder resin and a second binder resin, and the antistatic hard coat layer contains an antistatic agent-containing hard coat containing the above-mentioned antistatic agent and the above-mentioned first binder resin. Layer, hard coating layer containing the antistatic agent, which is in close contact with the hard coating layer containing the antistatic agent, does not contain the antistatic agent, and does not contain the antistatic agent containing hard the second binder resin A coat layer may be provided, and an interface between the antistatic agent-containing hard coat layer and the antistatic agent-free hard coat layer may be present in the region.

  The antistatic agent-containing hard coat layer comprises the antistatic agent, a first acrylate monomer having no alkylene oxide group, and having a weight average molecular weight of 400 or more and 900 or less and four or more acryloyl groups, and an alkylene It is a cured product of a composition for an antistatic agent-containing hard coat layer containing at least a second acrylate monomer having a weight average molecular weight of 150 or more and less than 400 having an oxide group and 2 or more acryloyl groups. Antistatic agent-free hardcoat layer containing at least a cured product of a photopolymerizable urethane oligomer having a weight average molecular weight of 1,000 to 70,000 and having a photopolymerizable functional group having a content of 4 or more It is a cured product of the composition, and the light transmitting substrate is near the interface with the antistatic agent-containing hard coat layer. Cured product of permeated product containing the first acrylate monomer and the second acrylate monomer, which penetrates the light transmitting substrate from the light transmitting substrate and the composition for the antistatic agent-containing hard coat layer And a mixed region including

  The antistatic hard coat layer may further include a low refractive index layer adjacent to the antistatic hard coat layer and having a refractive index lower than that of the antistatic hard coat layer.

  According to another aspect of the present invention, the optical film is formed on the side opposite to the side on which the antistatic hard coat layer is formed on the light transmitting substrate of the optical film. There is provided a polarizing plate comprising: a polarizer.

  According to another aspect of the present invention, there is provided a liquid crystal display panel comprising the above optical film or the above polarizing plate.

  According to another aspect of the present invention, there is provided an image display comprising the above optical film or the above polarizing plate.

According to one aspect of the present invention, the antistatic agent is mainly in the region of 0.2 μm or more and less than 2.0 μm in depth from the surface of the antistatic hard coat layer in the antistatic hard coat layer. Since it exists, the surface resistance value of the optical film can be 1 × 10 ¹¹ Ω / □ or less. In addition, since the antistatic agent is not present on the surface of the antistatic hard coat layer, even when the optical film is saponified, the antistatic agent is unlikely to come off. Therefore, even when an optical film having a surface resistance value of 1 × 10 ¹¹ Ω / □ or less is subjected to a saponification treatment, a reduction in the surface resistance value can be suppressed, and excellent antistatic properties can be maintained. In addition, even when the optical film is subjected to a saponification treatment, the antistatic agent is unlikely to come off, so that excellent scratch resistance can be maintained. As a result, it is possible to provide an optical film capable of maintaining excellent antistatic properties and scratch resistance even when saponification treatment is performed. Moreover, according to the other aspect of this invention, the polarizing plate provided with such an optical film, a liquid crystal panel, and an image display apparatus can be provided.

Further, the antistatic hard coat layer comprises the above antistatic agent, a photopolymerizable urethane oligomer having a weight average molecular weight of 1,000 to 70,000, and an alkylene oxide having four or more photopolymerizable functional groups. Group having a weight average molecular weight of 400 or more and 900 or less having a weight average molecular weight of 400 or more and 900 or less and a weight average molecular weight of 150 or more and 400 or more having an alkylene oxide group and 2 or more of acryloyl groups. A cured product of the composition for antistatic hard coat layer containing less than the second acrylate monomer and the permeable solvent, and the light transmitting substrate is light near the interface with the antistatic hard coat layer A transparent substrate, and a first acrylate monomer and a second acrylate, which are permeated from the composition for antistatic hard coat layer to the light transparent substrate In addition to the above effects, in the case of having a mixed region containing a cured product of a permeated substance containing a monomer, it is possible to suppress the generation of interference fringes and to prevent an antistatic hard coat having a thickness of 4 μm to 10 μm. Also in the layer, excellent hardness can be obtained. In addition, an optical film having a surface resistance value of 1 × 10 ¹¹ Ω / □ or less before the saponification treatment can be stably provided.

It is a schematic block diagram of the optical film which concerns on 1st Embodiment. It is an enlarged view of upper region vicinity of the optical film which concerns on 1st Embodiment. It is the figure which showed typically the manufacturing process of the optical film which concerns on 1st Embodiment. It is the figure which showed typically the manufacturing process of the optical film which concerns on 1st Embodiment. It is a schematic block diagram of the polarizing plate which concerns on 1st Embodiment. It is a schematic block diagram of the liquid crystal panel concerning 1st Embodiment. It is a schematic block diagram of the liquid crystal display which is an example of the image display apparatus which concerns on 1st Embodiment. It is a schematic block diagram of the optical film which concerns on 2nd Embodiment. It is an enlarged view of upper region vicinity of the optical film which concerns on 2nd Embodiment. It is the figure which showed typically the manufacturing process of the optical film which concerns on 2nd Embodiment. It is the figure which showed typically the manufacturing process of the optical film which concerns on 2nd Embodiment.

First Embodiment
Hereinafter, an optical film according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration view of an optical film according to the present embodiment, FIG. 2 is an enlarged view around the upper region of the optical film according to the present embodiment, and FIGS. 3 and 4 are optical films according to the present embodiment It is the figure which showed typically the manufacturing process of. In the present specification, terms such as "film", "sheet", "plate" and the like are not distinguished from one another based only on the difference in designation. Thus, for example, "film" is a concept that also includes members that may be called sheets or plates. In the present specification, when the fine particles are in the state of aggregated particles (secondary particles), the “average particle diameter” of the particles is calculated by calculating the particle diameter of the individual particles from the average of the major diameter and the minor diameter of the aggregated particles. , It can be calculated by averaging. Specifically, any two aggregated particles from the surface image or cross-sectional image of the optical film by an atomic force microscope (AFM) or the surface image or cross-sectional image of the optical film by a scanning transmission electron microscope (TEM, STEM) (In the case of the surface image, it is possible to select two at random, but in the case of the cross section, select two particles as large as possible because it is unclear where the particles are cut.) Measure the major diameter and minor diameter of each particle to calculate the aggregation diameter of each aggregate particle, and perform the same operation nine times in imaging another image of the same sample, and the number average particle diameter of 20 particles in total The value obtained from the above was taken as the average particle size of the fine particles. Note that “long diameter” is the longest diameter on the screen of aggregated particles, “short diameter” draws a line segment orthogonal to the middle point of the line segment that constitutes the long diameter, and this line segment intersects with the aggregated particles 2 Let us say the distance between points. In the present specification, when the fine particles are not in the state of aggregated particles, ie, in the state of primary particles, the average particle diameter of the primary particles of the fine particles can be calculated by the following operations (1) to (3) . In addition, the average particle diameter of the microparticles | fine-particles which have the space | gap contained in the low-refractive-index layer mentioned later can be calculated by the same method. (1) The fine particles themselves or a dispersion of the fine particles is coated on a light transmitting substrate and dried, and a surface image of a TEM or STEM is taken. (2) Arbitrary 10 fine particles are extracted from the surface image, the long diameter and the short diameter of each fine particle are measured, and the particle diameter of each fine particle is calculated from the average of the long diameter and the short diameter. (3) The same operation was carried out five times in the imaging of another image of the same sample, and the value obtained from the number average of 50 particles in total was taken as the average particle diameter.

<<< Optical film >>>
As shown in FIG. 1, the optical film 10 comprises at least a light transmitting substrate 11 and an antistatic hard coat layer 12 provided on the light transmitting substrate 11. The optical film 10 shown in FIG. 1 is provided on the antistatic hard coat layer 12 in addition to the light transmitting substrate 11 and the antistatic hard coat layer 12, and is adjacent to the antistatic hard coat layer 12. Although the low refractive index layer 13 is provided, the optical film 10 may not have the low refractive index layer 13. In the vicinity of the interface of the antistatic hard coat layer 12 in the light transmitting base 11, light is transmitted from the light transmitting base 11 and the composition for antistatic hard coat layer described later as shown in FIG. It is preferable that a mixed region 11A in which the cured product of the permeated material containing the first acrylate monomer and the second acrylate monomer, which has permeated the permeable substrate 11, is formed.

<< light transmitting base material >>
The light transmitting substrate 11 is not particularly limited as long as it has light transmitting properties, and examples thereof include a cellulose acylate substrate, a cycloolefin polymer substrate, a polycarbonate substrate, an acrylate-based polymer substrate, and a polyester substrate. Be

  Examples of the cellulose acylate base include cellulose triacetate base and cellulose diacetate base. As a cycloolefin polymer base material, the base material which consists of polymers, such as a norbornene-type monomer and a single ring cycloolefin monomer, is mentioned, for example.

  Examples of polycarbonate substrates include aromatic polycarbonate substrates based on bisphenols (such as bisphenol A), and aliphatic polycarbonate substrates such as diethylene glycol bis allyl carbonate.

  As the acrylate-based polymer substrate, for example, a methyl poly (meth) acrylate substrate, a poly (ethyl) acrylate substrate, a methyl (meth) acrylate-butyl (meth) acrylate copolymer substrate, etc. It can be mentioned.

  As a polyester base material, the base material etc. which have at least 1 sort (s) of a polyethylene terephthalate, a polypropylene terephthalate, a polybutylene terephthalate, and a polyethylene naphthalate as a component are mentioned, for example.

  Among these, a cellulose acylate substrate is preferable because it is excellent in light transmittance, and among cellulose acylate substrates, a triacetyl cellulose substrate (TAC substrate) is more preferable. The triacetyl cellulose base is a light transmitting base that can have an average light transmittance of 50% or more in the visible light range of 380 to 780 nm. The average light transmittance of the triacetyl cellulose base is preferably 70% or more, and more preferably 85% or more.

  In addition to the pure triacetylcellulose, the triacetylcellulose base may be a combination of cellulose acetate propionate, cellulose acetate butyrate and other components other than acetic acid as fatty acids forming an ester with cellulose. Good. In addition, other additives such as cellulose lower fatty acid ester such as diacetyl cellulose, or plasticizers, ultraviolet absorbers, and lubricants may be added to these triacetyl celluloses, as necessary.

  The thickness of the light transmitting substrate 11 is not particularly limited, but is usually about 20 μm to 1000 μm, and more preferably 25 μm to 80 μm in consideration of durability, handling property, and the like.

  The light transmitting substrate 11 is, as required, subjected to surface treatment for strengthening adhesion such as glow discharge treatment, corona discharge treatment, ultraviolet light (UV) treatment, flame treatment, primer layer formation, etc. It may be.

<< Mixed area >>
The mixed area 11A is for suppressing the occurrence of interference fringes. That is, light reflected at the interface between the light transmitting substrate and the antistatic hard coat layer due to the difference in refractive index between the light transmitting substrate and the antistatic hard coat layer, and the antistatic hard coat Interference with the light reflected by the surface of the layer may cause an iridescent unevenness pattern called interference fringes to occur. On the other hand, in the case where the mixed area 11A is formed as shown in FIG. 1, the mixed area 11A contains the first composition which penetrates the light transmitting substrate 11 from the composition for antistatic hard coat layer described later. Since the cured product of the permeate containing the acrylate monomer and the second acrylate monomer is included, the generation of interference fringes can be suppressed for the reason described later. Further, the adhesion between the light transmitting substrate 11 and the antistatic hard coat layer 12 can be further improved by forming the mixed region 11A.

  The thickness of the mixed area 11A is preferably 1 μm or more and 6 μm or less. In addition, since the thickness of the mixed area formed of the conventional antireflection film is often about 7 μm to 20 μm, it is assumed that the thickness of the mixed area 11A is thinner than that of the mixed area formed of the conventional antireflection film. I can say that. The reason why the thickness of the mixed region 11A can be reduced is presumed to be because the first acrylate monomer and the second acrylate monomer described later are used in combination. In addition, when a mixed region of a sufficient thickness is formed, the mixed region is relatively soft, and thus there is a possibility that an excellent hardness can not be obtained in the optical film. On the other hand, since the mixed region 11A can be thinned in the present embodiment, excellent hardness can be obtained in the optical film 10.

<< Antistatic Hard Coat Layer >>
The antistatic hard coat layer 12 contains an antistatic agent 14 having a quaternary ammonium base and having a weight average molecular weight of 1,000 to 50,000 and a binder resin 15, and JIS K5600-5-4. It shows a hardness of "H" or more in a pencil hardness test (4.9 N load) defined in (1999).

  The antistatic hard coat layer 12 has a thickness of 4 μm to 10 μm. By setting the film thickness of the antistatic hard coat layer 12 to 4 μm or more, excellent hardness can be obtained. Further, by setting the film thickness of the antistatic hard coat layer 12 to 10 μm or less, the optical film 10 can be thinned. The upper limit of the film thickness of the antistatic hard coat layer 12 is preferably 8 μm or less. The film thickness of the antistatic hard coat layer can be determined by observing the cross section of the antistatic hard coat layer with a scanning electron microscope (SEM). Specifically, the film thickness of three antistatic hard coat layers in one image is measured using an image of a scanning electron microscope, this is performed for five images, and the average value of the measured film thickness is calculated calculate.

  The refractive index layer of the antistatic hard coat layer 12 may be 1.50 or more and 1.60 or less. The lower limit of the refractive index of the antistatic hard coat layer 12 may be 1.52, and the upper limit of the refractive index of the antistatic hard coat layer 12 may be 1.56 or less. The difference in refractive index between the light transmitting substrate 11 and the antistatic hard coat layer 12 is preferably 0.10 or less, more preferably 0.06 or less, from the viewpoint of suppressing the occurrence of interference fringes. preferable.

  The refractive index of the antistatic hard coat layer 12 is constant at a refractive index of 380 nm to 780 nm, and the reflection spectrum measured by a spectrophotometer and the spectrum calculated from the optical model of the thin film using the Fresnel equation It can be determined by fitting. In addition, the refractive index of the antistatic hard coat layer 12 may be obtained by measurement with an Abbe refractometer (NAR-4T manufactured by Atago Co.) or an ellipsometer after forming a single layer. In addition, as a method of measuring the refractive index after forming the optical film 10, the antistatic hard coat layer 12 is scraped off with a cutter or the like to prepare a powder sample, and JIS K7142 (2008) B method (powder or Using a Becke method (for a transparent material in the form of particles) (using a Cargill reagent of known refractive index), place the powdered sample on a slide glass or the like, drip the reagent onto the sample, and immerse the sample with the reagent. The situation is observed by microscopic observation, and the refractive index of the reagent is used as the refractive index of the sample, because the bright line (Becke line) generated on the sample contour can not be visually observed due to the difference in the refractive index of the sample and the reagent. be able to.

  The antistatic agent 14 is not present on the surface 12 A of the antistatic hard coat layer 12. The “surface of the antistatic hard coat layer” means the surface of the antistatic hard coat layer opposite to the surface (rear surface) on the light transmitting substrate side. The fact that "the antistatic agent is not present on the surface of the antistatic hard coat layer" can be confirmed by examining the change in the scratch resistance of the optical film before and after the saponification treatment. That is, when the antistatic agent is present on the surface of the antistatic hard coat layer, when the optical film is subjected to the saponification treatment, the antistatic agent is dropped, so that the scratch resistance is higher than before the saponification treatment. If the antistatic agent is not present on the surface of the antistatic hard coat layer, the antistatic agent does not fall off even when the optical film is saponified. Before and after the saponification treatment, the scratch resistance is evaluated almost the same. Therefore, if the scratch resistance of the optical film before and after the saponification treatment is not reduced, it can be said that the antistatic agent is not present on the surface of the antistatic hard coat layer.

  As shown in FIG. 2, the antistatic agent 14 is a region R having a depth of 0.2 μm or more and less than 2.0 μm from the surface 12A of the antistatic hard coat layer 12 (hereinafter referred to as “upper region”). In the United States). Whether or not an antistatic agent is present in the upper region can be evaluated as follows. First, a composition containing the same antistatic agent and methyl ethyl ketone as the antistatic agent contained in the antistatic hard coat layer of the optical film to be evaluated is coated on one surface of a plurality of triacetyl cellulose films and dried. An antistatic layer having a thickness of 0.5 μm is formed on each triacetyl cellulose film. Next, a composition containing no antistatic agent and containing dipentaerythritol hexaacrylate (DPHA), toluene, and a polymerization initiator is applied onto each antistatic layer, and the hard coat layer is irradiated with ultraviolet light. To make a plurality of samples. However, the hard coat layer of each sample is formed so that the film thickness is different every 0.1 μm for each sample. After preparing a plurality of such samples, the surface resistance value of the optical film before saponification treatment related to the evaluation target and the surface resistance value of the hard coat layer of each sample are measured, and the surface resistance of the optical film related to the evaluation target Find a sample that exhibits a surface resistance value approximately the same as the value. Here, in the optical film according to the evaluation object, since the surface resistance value substantially the same as that of the sample found is found, it can be considered that the antistatic agent is present at substantially the same position as this sample. Therefore, at least the antistatic agent is located at a distance from the surface of the antistatic hard coat layer in the depth direction of the antistatic hard coat layer, which corresponds to the thickness of the hard coat layer of the found sample. It can be considered to exist. Then, if the film thickness of the hard coat layer of the found sample is within the range of 0.2 μm or more and less than 2.0 μm, it can be said that the antistatic agent is present in the upper region, If the film thickness of the hard coat layer is 2.0 μm or more, it can be said that the antistatic agent is not present in the upper region. As described above, it is possible to evaluate whether the antistatic agent is present in the upper region by evaluating the antistatic property using the sample.

If the depth of the upper region from the surface of the antistatic hard coat layer is 0.2 μm or more and less than 2.0 μm, dropping of the antistatic agent due to the saponification treatment is suppressed, and it is excellent before and after the saponification treatment and if you try to maintain the scratch resistance, the depth from the surface of the antistatic agent antistatic hard coat layer is required to be present in the 0.2μm or more locations, also 1 × 10 ¹¹ or less of the charge In order to obtain the prevention property, it is necessary for the antistatic agent to be present at a depth of less than 2.0 μm from the surface of the antistatic hard coat layer.

  From the viewpoint of further suppressing the dropout of the antistatic agent due to the saponification treatment and maintaining the excellent scratch resistance before and after the saponification treatment, the antistatic agent 14 is one of the antistatic hard coat layer 12 in the upper region R. It is preferable that the depth from the surface 12A be in a region of 0.3 μm or more.

From the viewpoint of obtaining a surface resistance value of 9 × 10 ¹⁰ Ω / □ or less, the antistatic agent 14 is a region of 1.5 μm or less in depth from the surface 12 A of the antistatic hard coat layer 12 in the upper region R. Are preferably present. Further, from the viewpoint of obtaining a surface resistance value of 9 × 10 ⁹ Ω / sq or less, the antistatic agent 14 has a depth of 1.0 μm or less from the surface 12A of the antistatic hard coat layer 12 in the upper region R. It is preferably present in the region of

  The antistatic agent 14 is preferably localized in the upper region R. "The antistatic agent is localized in the upper region" means that the antistatic agent is concentrated in the upper region and the proportion of the antistatic agent is extremely low in the region outside the upper region. It means that. Thus, the highest peak of concentration of antistatic agent is present in the upper region. By localizing the antistatic agent 14 in the upper region R, the excellent antistatic property can be reliably maintained. Preferably, the antistatic agent 14 is localized in the upper region R in a proportion of 75% by mass or more based on the total amount of the antistatic agent present in the antistatic hard coat layer 12.

<Antistatic agent>
As described above, the antistatic agent 14 has a weight average molecular weight of 1,000 to 30,000. When the weight average molecular weight of the antistatic agent is 1,000 or more, the antistatic agent hardly bleeds out on the surface of the antistatic hard coat layer, and when the weight average molecular weight is 30,000 or less, the antistatic property The decrease in coating suitability can be suppressed without the viscosity of the composition for hard coat layer becoming too high.

  The lower limit of the weight average molecular weight of the antistatic agent 14 is preferably 1,500 or more, and more preferably 2,000 or more. The upper limit of the weight average molecular weight of the antistatic agent 14 is preferably 25,000 or less, and more preferably 20,000 or less.

  The "weight-average molecular weight" in the present specification is a value obtained by dissolving in a solvent such as THF and the like, and converting it to polystyrene by a gel permeation chromatography (GPC) method known to date.

  As the antistatic agent 14, for example, a copolymer of a monomer having a quaternary ammonium base and a monomer having no quaternary ammonium base can be used.

  As the above-mentioned copolymer, for example, after quaternizing an N, N-dialkylamino group-containing monomer, it is polymerized with a monomer having no quaternary ammonium base, or N, N-dialkylamino group-containing After copolymerizing a monomer and the monomer which does not have a quaternary ammonium base, it can obtain by quaternizing the N, N- dialkyl amino group which the obtained copolymer has.

  As the N, N-dialkylamino group-containing monomer, for example, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N , N-diethylaminopropyl (meth) acrylate, N, N-dimethylaminobutyl (meth) acrylate, N, N-diethylaminobutyl (meth) acrylate, N, N-dihydroxyethylaminoethyl (meth) acrylate, N, N- Dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, etc. are mentioned, Among them, N, N-dimethylaminoethyl (meth) acrylate is a kind of a preferable compound in that excellent saponification resistance can be obtained. It is.

  As a monomer which does not have a quaternary ammonium base which constitutes the above-mentioned copolymer, for example, (meth) acrylic acid or methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl Alkyl (meth) acrylates such as (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, dodecyl (meth) acrylate or 2-hydroxyethyl Hydroxyalkyl (meth) acrylates such as (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate or benzyl (meth) acrylate or cyclohexyl (meth) acrylate Alkyl (meth) acrylate having a cyclic structure such as isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyl oxyethyl (meth) acrylate, glycidyl (meth) acrylate, or ethoxyethyl (meth) acrylate And alkoxyalkyl (meth) acrylates such as butoxyethyl (meth) acrylate, or various (meth) acrylates such as ethyl carbitol (meth) acrylate and cyanoethyl (meth) acrylate, or methyl (meth) acrylamide, ethyl (meth) acrylate ) Acrylamide, propyl (meth) acrylamide, butyl (meth) acrylamide, 2-ethylhexyl (meth) acrylamide, stearyl (meth) acrylamide, lauryl (meth) a Alkyl (meth) acrylamides such as llylamide, tridecyl (meth) acrylamide, dodecyl (meth) acrylamide, or hydroxyethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylamide, hydroxypropyl (meth) acrylamide, 2-hydroxypropyl Hydroxyalkyl (meth) acrylamides such as (meth) acrylamides, hydroxybutyl (meth) acrylamides, or benzyl (meth) acrylamides, cyclohexyl (meth) acrylamides, isobornyl (meth) acrylamides, dicyclopentenyl (meth) acrylamides, dicyclo Alkyl (meth) acryl acid having a cyclic structure such as pentenyloxyethyl (meth) acrylamide, glycidyl (meth) acrylamide, etc. Or alkoxyalkyl (meth) acrylamides such as ethoxyethyl (meth) acrylamide and butoxyethyl (meth) acrylamide, or various (meth) acrylamides such as ethyl carbitol (meth) acrylamide and cyanoethyl (meth) acrylamide, or , Styrene, methyl styrene and the like. In particular, dodecyl (meth) acrylate and tridecyl (meth) acrylate are preferably used in terms of high solubility of the resulting copolymer in an organic solvent and hydrophobic strength.

  In addition, as a monomer not having a quaternary ammonium base, an organopolysiloxane based monomer, for example, polydimethylsiloxane having a (meth) acryloyl group may be used.

  As a preferable copolymer from the viewpoint of saponification resistance, for example, a monomer having a quaternary ammonium base is N, N-dimethylaminoethyl (meth) acrylate and a monomer having no quaternary ammonium base is It is a copolymer obtained by copolymerizing one or two or more selected from the group of dodecyl (meth) acrylate and tridecyl (meth) acrylate.

  The quaternary ammonium base can be obtained by modification with a cationizing agent and quaternization treatment. The quaternary ammonium base is preferably one obtained by modifying the N, N-dialkylamino group with a cationizing agent and subjecting it to quaternization treatment. As a cationizing agent, for example, alkyl halides such as methyl halide, ethyl halide, normal propyl halide, isopropyl halide, normal butyl halide, isopropyl halide, normal hexyl halide, 2-ethylhexyl halide, octyl halide, lauryl halide, stearyl halide, or Monochloroacetic acid salts such as sodium monochloroacetate and potassium monochloroacetate; monochloroacetic acid esters such as methyl monochloroacetate and ethyl monochloroacetate; and 3-chloro-2-hydroxypropyltrimethylammonium chloride. One of these cationizing agents may be used alone, or two or more thereof may be used in combination.

  Among these, the quaternary ammonium base is an N, N-dialkylamino group as an alkyl halide, monochloroacetic acid salt, monochloroacetic ester, and 3-chloro-2-hydroxypropyl from the viewpoint of high reactivity, antistatic property, etc. Those obtained by modification with a cationizing agent selected from trimethyl ammonium chloride are preferred, more preferably alkyl chloride, still more preferably alkyl chloride having 1 to 2 carbon atoms, particularly preferably obtained by modification with methyl chloride It is a thing.

  In addition, the antistatic agent 14 may have a photopolymerizable functional group. In the present specification, the "photopolymerizable functional group" is a functional group that can be crosslinked by light irradiation. Moreover, in this specification, the number of photopolymerizable functional groups may be expressed as "functional number". As a photopolymerizable functional group, the group which has ethylenic double bonds, such as a (meth) acryloyl group, a vinyl group, an allyl group, is mentioned, for example. The “(meth) acryloyl group” is a concept including both “acryloyl group” and “methacryloyl group”. By using an antistatic agent having a photopolymerizable functional group, the antistatic agent and the first acrylate monomer can be crosslinked at the time of curing of the composition for antistatic hard coat layer. As a result, it is possible to effectively prevent the bleeding out of the antistatic agent over time onto the surface of the antistatic hard coat layer. When the antistatic agent has a photopolymerizable functional group, the antistatic agent crosslinks with the monomer and the like, so the antistatic agent falls off even when the antistatic agent is present on the surface of the antistatic hard coat layer. It can be considered that the abrasion resistance does not decrease because it is difficult to do so, but in fact, when the antistatic agent is present on the surface of the antistatic hard coat layer, the abrasion resistance test is carried out. The antistatic agent falls off and the scratch resistance is reduced.

  Examples of commercial products of the antistatic agent 14 include 1SX3000 manufactured by Taisei Fine Chemical Co., Ltd. and Corcoat NR121X manufactured by Corcoat Co., Ltd.

  When the quaternary ammonium base contains chlorine, the content of the quaternary ammonium salt in the antistatic hard coat layer 12 is specified by measuring the chlorine concentration in the antistatic hard coat layer 12 be able to. Specifically, from the viewpoint of antistatic property, the chlorine concentration in the antistatic hard coat layer 12 is preferably 100 ppm to 700 ppm, and more preferably 150 ppm to 550 ppm. When it exceeds 700 ppm, the antistatic property is improved before the saponification treatment, but the antistatic property is deteriorated after the saponification treatment, and the saponification resistance is inferior. The chlorine concentration in the antistatic hard coat layer 12 can be measured, for example, by combustion-ion chromatography.

<Binder resin>
The binder resin 15 of the present embodiment is a cured product of a mixture containing a photopolymerizable urethane oligomer described later, a first acrylate monomer, a second acrylate monomer, and a methacrylate monomer. The mixture may contain the photopolymerizable urethane oligomer, the first acrylate monomer, and the second acrylate monomer, and may not contain the methacrylate monomer.

  The antistatic hard coat layer may have not only a single layer structure but also a laminated structure in which two or more layers are laminated. The antistatic hard coat layer 12 shown in FIG. 1 has a single layer structure, and the antistatic hard coat layer 52 shown in FIG. 8 has a laminated structure.

  The antistatic hard coat layer 12 is a layer formed of a cured product of the composition for antistatic hard coat layer. The composition for antistatic hard coat layer includes, for example, the above-mentioned antistatic agent, a photopolymerizable urethane oligomer having a weight average molecular weight of 1,000 to 70,000 or less, and an alkylene oxide having 4 or more photopolymerizable functional groups. The first acrylate monomer having no group and having a weight average molecular weight of 400 to 900 having four or more acryloyl groups, the weight average molecular weight having an alkylene oxide group and two or more acryloyl groups is 150 to less than 400 A second acrylate monomer, a methacrylate monomer having a weight average molecular weight of 300 or more and 1,000 or less having two or more methacryloyl groups, a permeable solvent, and a polymerization initiator are included. The composition for antistatic hard coat layer may contain the above antistatic agent, the above photopolymerizable urethane oligomer, the above first acrylate monomer, the above second acrylate monomer, and the above permeable solvent. The methacrylate monomer and the polymerization initiator may not be contained.

  In the composition for antistatic hard coat layer, charging is performed from the viewpoint of ensuring that the antistatic agent 14 is present in the upper region R, the viewpoint of surely suppressing the occurrence of interference fringes, and the viewpoint of surely obtaining excellent hardness. The antistatic agent 14 is 0.01% by mass or more and 6% by mass or less, and the photopolymerizable urethane oligomer is 5% by mass or more and 62% by mass or less based on the total mass of the total solid content of the composition for hard coat layer prevention Preferably, the first acrylate monomer is contained in an amount of 5% by mass to 52% by mass, and the second acrylate monomer is contained in a proportion of 5% by mass to 50% by mass.

  When the content of the antistatic agent 14 exceeds 6% by mass with respect to the total mass of the total solid content of the composition for antistatic hard coat layer, the antistatic property is improved, but charging after the saponification treatment The prevention performance is deteriorated and the saponification resistance is inferior. From the viewpoint of obtaining more excellent antistatic properties, the lower limit of the content of the antistatic agent 14 is 0.1% by mass or more based on the total mass of the total solid content of the composition for antistatic hard coat layer Is preferably 0.3% by mass or more. Moreover, from the viewpoint of obtaining more excellent scratch resistance, the upper limit of the content of the antistatic agent 14 is preferably 5% by mass or less, and more preferably 3% by mass or less.

  Excellent hardness can be obtained when the content of the photopolymerizable urethane oligomer is 15% by mass or more based on the total mass of the total solid content of the composition for antistatic hard coat layer, and low The adhesion to the refractive index layer can be improved. Moreover, since the ratio of a 1st acrylate monomer and a 2nd acrylate monomer can be increased as content of the said photopolymerizable urethane oligomer is 62 mass% or less, the mixed area | region of desired thickness is formed. And the generation of interference fringes can be further suppressed. From the viewpoint of suppressing the curling of the optical film, the lower limit of the content of the photopolymerizable urethane oligomer is 60% by mass or less based on the total mass of the total solid content of the composition for antistatic hard coat layer preferable.

  The curling of the optical film is suppressed when the content of the first acrylate monomer is 5% by mass or more and 52% by mass or less based on the total mass of the total solid content of the composition for antistatic hard coat layer At the same time, an antistatic hard coat layer excellent in hardness can be obtained. From the viewpoint of suppressing the curl of the optical film, the upper limit of the content of the first acrylate monomer is 50% by mass or less based on the total mass of the total solid content of the composition for antistatic hard coat layer preferable.

  When the content of the second acrylate monomer is 5% by mass or more and 50% by mass or less with respect to the total mass of the total solid content of the composition for antistatic hard coat layer, generation of interference fringes and curling It can be suppressed. From the viewpoint of further improving the abrasion resistance, the upper limit of the content of the second acrylate monomer is 45% by mass or less based on the total mass of the total solid content of the composition for antistatic hard coat layer preferable.

  The content of the methacrylate monomer is preferably 5% by mass or more and 30% by mass or less based on the total mass of the total solid content of the antistatic hard coat layer composition. If the content of the methacrylate monomer is less than 5% by mass, adhesion may not be improved, and if it exceeds 30% by mass, the hardness is lowered. There is a risk of

<Photopolymerizable urethane oligomer>
The photopolymerizable urethane oligomer is a component of the binder resin 15 after curing of the composition for antistatic hard coat layer. As described above, the photopolymerizable urethane oligomer is an oligomer having a weight average molecular weight of 1,000 or more and 70,000 or less having four or more photopolymerizable functional groups.

  The photopolymerizable urethane oligomer has 4 or more photopolymerizable functional groups, but when the photopolymerizable functional group is 4 or more, excellent hardness can be obtained. Further, when the low refractive index layer is provided on the antistatic hard coat layer, the adhesion to the low refractive index layer can be improved, so that the peeling of the low refractive index layer in the saponification treatment can be suppressed. it can. The photopolymerizable urethane oligomer preferably has 6 or more photopolymerizable functional groups.

  The photopolymerizable urethane oligomer has a weight average molecular weight of 1,000 or more and 70,000 or less, and when the weight average molecular weight of the photopolymerizable urethane oligomer is in the above range, excellent hardness can be obtained. The photopolymerizable urethane oligomer preferably has a weight average molecular weight of 1,000 or more and 50,000 or less.

（式［１］中、Ａｃは（メタ）アクリロイル基であり、Ｒ−（Ａｃ）_５はジペンタエリスリトールが有する６個のヒドロキシル基のうち５個のヒドロキシル基の水素原子が（メタ）アクリロイル基Ａｃで置き換わった５官能（メタ）アクリレート基である。） As a photopolymerizable urethane oligomer, urethane (meth) acrylate is mentioned, for example. Examples of the urethane (meth) acrylate include urethane (meth) acrylate having a 15-functional (meth) acryloyl group having an isocyanuric acid skeleton represented by the following formula [1].

(In the formula [1], Ac is a (meth) acryloyl group, and R- (Ac) ₅ is a (meth) acryloyl group in which the hydrogen atoms of five hydroxyl groups among six hydroxyl groups possessed by dipentaerythritol are It is a pentafunctional (meth) acrylate group replaced by Ac.)

  A commercial item may be used for a photopolymerizable urethane oligomer, and as a commercial item, for example, UV 1700 B manufactured by Nippon Synthetic Chemical Industry Co., Ltd., U-15 HA manufactured by Shin-Nakamura Chemical Co., Ltd., and the like can be mentioned.

<First Acrylate Monomer>
The first acrylate monomer is a component of the binder resin 15 after curing of the antistatic hard coat layer composition. As described above, the first acrylate monomer is a monomer having no alkylene oxide group and having a weight average molecular weight of 400 or more and 900 or less having four or more acryloyl groups. If the first acrylate monomer has an alkylene oxide group, the hardness will be inferior, and if the molecular weight is large, the proportion of acryloyl groups will be small, so the adhesion to the low refractive index layer will be poor.

  The first acrylate monomer has four or more acryloyl groups, but when the number of acryloyl groups is four or more, excellent hardness can be obtained, and it is low on the antistatic hard coat layer. When the refractive index layer or the like is formed, the adhesion of the low refractive index layer or the like can be improved.

  Specifically, examples of the first acrylate monomer include dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, tripentaerythritol octaacrylate, tetrapentaerythritol decaacrylate, diglycerin tetraacrylate, and ditrimethylolpropane tetraacrylate. .

  Among these, dipentaerythritol hexaacrylate (DPHA) and the like are preferable from the viewpoint of obtaining an antistatic hard coat layer having high hardness.

<Second acrylate monomer>
The second acrylate monomer is to be a component of the binder resin 15 after curing of the composition for antistatic hard coat layer. As described above, the second acrylate monomer is a monomer having an alkylene oxide group and two or more photopolymerizable functional groups and having a weight average molecular weight of 150 or more and less than 400. The lower limit of the weight average molecular weight of the second acrylate monomer is preferably 500 or less. The above "alkylene oxide group" means that an epoxy ring is opened.

As an alkylene oxide group of the second acrylate monomer, for example, ethylene oxide group (-CH ₂ -CH ₂ -O-) _m , propylene oxide group ((-CH ₂ -CH ₂ -CH ₂ -O-) _n , (- _{CH 2 -CH (CH 3) -O-} ) p, or _{(-CH (CH 3) -CH 2} -O-) q) are mentioned. The m represents an integer of 1 to 6, n and p represent an integer of 1 to 2, and q represents an integer of 1 to 4. In the second acrylate monomer, the number of alkylene oxide groups does not matter as long as the combined molecular weight of the alkylene oxide group and the portion other than the alkylene oxide group is less than 400. When the second acrylate monomer has an alkylene oxide group, an antistatic agent can be stably present in the composition for antistatic hard coat layer.

  The second acrylate monomer is one having two or more acryloyl groups. The reason why the number of acryloyl groups in the second acrylate monomer is 2 or more is that the hardness is inferior when the number of acryloyl groups is one (one function) and there is a risk of scattering in the drying / ultraviolet irradiation step. It is. In addition, skin irritation may be strong, and safety may be lost. Further, the number of acryloyl groups of the second acrylate monomer is preferably 4 or less.

  Specifically, as the second acrylate monomer, propylene oxide-modified diacrylate, ethylene oxide (EO) isocyanurate-modified di- and triacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane Triacrylate etc. are mentioned. The propylene oxide in the propylene oxide-modified diacrylate and the ethylene oxide in the ethylene oxide (EO) -modified di and triacrylates of isocyanuric acid are present in the molecule in the state where the epoxy ring is opened.

  As a commercial item of the 2nd acrylate monomer, M-240 by Toagosei Co., Ltd. is mentioned, for example.

[Methacrylate monomer]
The methacrylate monomer is to be a component of the binder resin 15 after curing of the antistatic hard coat layer composition. The methacrylate monomer is a monomer having a weight average molecular weight of 300 or more and 1,000 or less having two or more methacryloyl groups as described above.

  The methacrylate monomer has a methacryloyl group, but the presence of the methacryloyl group can improve the adhesion between the antistatic hard coat layer 12 and the low refractive index layer 13 as described later.

  The methacrylate monomer has two or more methacryloyl groups, but the reason why the number of methacryloyl groups in the methacrylate monomer is two or more is inferior in hardness when the number of methacryloyl groups is one (one function). Also, it is likely to be scattered in the drying / ultraviolet irradiation step. In addition, skin irritation may be strong, and safety may be lost.

  The methacrylate monomer has a weight average molecular weight of 300 or more and 1,000 or less. When the weight average molecular weight is within the above range, the hardness of the antistatic hard coat layer can be improved. The methacrylate monomer preferably has a weight average molecular weight of 300 or more and 900 or less.

  Specifically, as methacrylate monomers, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol pentamethacrylate, tripentaerythritol octamethacrylate, tetrapentaerythritol decamethacrylate, diglycerin tetramethacrylate, Ditrimethylolpropane tetramethacrylate and the like can be mentioned.

  Among these, trimethylolpropane trimethacrylate and the like are preferable from the viewpoint of improving the hardness and from the viewpoint that the antistatic agent can be present in the upper region due to the incompatibility with the antistatic agent.

<Permeable solvent>
The permeable solvent is a solvent that has high permeability to the light transmitting substrate 11 and dissolves or swells the light transmitting substrate 11. By using a permeable solvent, not only the permeable solvent but also the first acrylate monomer and the second acrylate monomer can be permeated into the light transmitting substrate 11.

  Examples of the osmotic solvent include ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl isobutyl ketone, diacetone alcohol, cycloheptanone and diethyl ketone; methyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate , Esters having a boiling point of less than 85 ° C. such as ethyl lactate; nitrogen-containing compounds such as nitromethane, acetonitrile, N-methylpyrrolidone, N, N-dimethylformamide; glycols such as methyl glycol and methyl glycol acetate; Ethers having a boiling point of less than 100 ° C. such as 4-dioxane, dioxolane and diisopropyl ether; halogenated hydrocarbons such as methylene chloride, chloroform and tetrachloroethane; methyl cellosolve, ethyl cellosolve, Cellosolve, glycol ethers such as cellosolve acetate and the like; dimethyl sulfoxide, propylene carbonate. Moreover, these mixtures may be sufficient. Among these, at least one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, butyl acetate and methyl ethyl ketone is preferable.

  The addition amount of the permeable solvent is preferably 50 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the total solid content of the composition for antistatic hard coat layer. When the amount of the permeable solvent added is 50 parts by mass or more, the permeable solvent sufficiently penetrates the light transmitting substrate to further suppress the generation of interference fringes, and when the amount is 500 parts by mass or less There is no possibility that the organic solvent dissolves or swells the light transmitting substrate more than necessary, and an excellent hardness as an optical film can be obtained.

<Polymerization initiator>
The polymerization initiator is a component that is decomposed by light irradiation to generate radicals to initiate or promote crosslinking of the first acrylate monomer or the like.

  The polymerization initiator is not particularly limited as long as it can release a substance that initiates radical polymerization by light irradiation. Examples of the polymerization initiator include acetophenones, benzophenones, ketals, anthraquinones, disulfide compounds, thiuram compounds, fluoroamine compounds and the like. More specifically, 1-hydroxy-cyclohexyl-phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, benzyl dimethyl ketone, 1- (4-do Tesylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methyl Propan-1-one, benzophenone and the like can be exemplified. Among these, 1-hydroxy-cyclohexyl-phenyl ketone and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one initiate polymerization reaction by light irradiation even in small amounts or It is preferable because it can be promoted. As the polymerization initiator, any one of the above-described ones can be used alone or in combination.

  As a commercial item of the polymerization initiator, for example, Irgacure (registered trademark) 184 (1-hydroxy-cyclohexyl-phenyl-ketone) manufactured by BASF Japan Ltd., Irgacure (registered trademark) 907 (2-methyl-1- (4-) Methylthiophenyl) -2-morpholinopropan-1-one), Irgacure® 127 (2-hydroxy-1 [4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl]- 2-methyl-propan-1-one), Lucillin (registered trademark) TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), and the like.

  The composition for antistatic hard coat layer may further contain a permeation suppressing solvent, a lubricant, a dispersant, and the like, if necessary.

<Permeation control solvent>
The permeation suppression solvent is a component for appropriately suppressing the permeation of the permeation solvent into the light transmitting substrate 11. That is, depending on the type of the light-transmissive substrate, the use of the permeable solvent may cause the light-transmissive substrate to be excessively roughened by the permeable solvent and cause whitening. By using the permeation suppressing solvent, it is possible to suppress the light transmissive substrate from being excessively roughened. Examples of the permeation suppressing solvent include esters having a boiling point of 85 ° C. or more and 125 ° C. or less, and ethers having a boiling point of 100 ° C. or more and 150 ° C. or less.

  As ester having a boiling point of 85 ° C. or more and 125 ° C. or less, one having a boiling point of 85 ° C. or more and 110 ° C. or less is preferable. Further, among such esters, those having a weight average molecular weight of 80 or more and 110 or less are preferable, and those having 90 or more and 105 or less are more preferable. The esters are not particularly limited as long as they have a boiling point of 80 ° C. or more and 125 ° C. or less. Examples of such esters include isopropyl acetate (boiling point: 88.6 ° C., weight average molecular weight: 102. 13), dimethyl carbonate (boiling point: 90 ° C., weight average molecular weight: 90.08), ethyl methyl carbonate (boiling point: 107 ° C., weight average molecular weight: 104.1).

  As ethers having a boiling point of 100 ° C. or more and 150 ° C. or less, those having a weight average molecular weight of 100 or more and 150 or less are preferable, and those with 120 or more and 140 or less are more preferable. Examples of such ethers include propylene glycol monomethyl ether acetate (boiling point: 146 ° C., weight average molecular weight: 132.16) and the like.

<Easy lubricant>
A lubricant (anti-blocking agent) is a component that prevents sticking when the antistatic hard coat layer 12 and the light transmitting substrate 11 are superimposed, for example, in a roll state. As the lubricant, conventionally known lubricants can be used. For example, fine particles of inorganic compounds such as silica described in JP-A No. 2004-284126 having an average primary particle diameter of 100 nm or more and 1000 nm or less and high density polyethylene Fine particles of organic compounds such as polystyrene and polystyrene acryl can be used. The content of the lubricant is preferably 0.1% by mass or more and 5% by mass or less based on the total mass of the total solid content of the composition for a hard coat layer.

<< Low refractive index layer >>
The low refractive index layer 13 is for reducing the reflectance when light from the outside (for example, a fluorescent lamp, natural light, etc.) is reflected on the surface of the optical film 10. The low refractive index layer 13 has a lower refractive index than the antistatic hard coat layer 12. Specifically, for example, the low refractive index preferably has a refractive index of 1.45 or less, more preferably 1.42 or less. The refractive index of the low refractive index layer 13 can be measured by the same method as the refractive index of the antistatic hard coat layer 12 described above.

Although the thickness of the low refractive index layer 13 is not limited, in general, it may be suitably set from the range of 30 nm or more and 1 μm or less. The thickness d (nm) of the low refractive index layer 13 preferably satisfies the following formula (1).
d = mλ / (4n) (1)
In the above formula, n represents the refractive index of the low refractive index layer, m represents a positive odd number, preferably is 1, and λ is the wavelength, preferably a value in the range of 480 nm to 580 nm.

The low refractive index layer 13 preferably has the following formula (2) from the viewpoint of lowering the reflectance.
120 <nd <145 (2)

  The film thickness of the low refractive index layer can be determined by observing the cross section of the low refractive index layer with a transmission electron microscope (TEM, STEM) (the magnification is preferably 10,000 times or more). Specifically, using the image of a transmission electron microscope, the film thickness of three low refractive index layers in one image is measured, this is performed for five images, and the average value of the measured film thicknesses is calculated. .

  Although the low refractive index layer is effective in a single layer, it is also possible to appropriately provide two or more low refractive index layers for the purpose of adjusting a lower minimum reflectance or a higher minimum reflectance. When providing two or more low refractive index layers, it is preferable to provide a difference in the refractive index and thickness of each low refractive index layer.

  As the low refractive index layer 13, a layer formed of a cured product of the photocurable low refractive index layer composition can be used. The composition for a photocurable low refractive index layer is a composition which is cured by light irradiation to form a low refractive index layer, and, for example, (1) fine particles having voids and at least one of metal fluoride and non-fluorinated light A composition containing a polymerizable compound, (2) a composition containing a fluorine-containing photopolymerizable compound, or (3) a fine particle having a void and a composition containing at least one of a metal fluoride and a fluorine-containing photopolymerizable compound Can be mentioned. Here, in the present specification, the “photopolymerizable compound” means at least one of a photopolymerizable monomer, a photopolymerizable oligomer, and a photopolymerizable prepolymer.

(1) Composition containing fine particles having voids and at least one of metal fluorides and fluorine-free photopolymerizable compounds <fine particles having voids>
The fine particles having voids are a component for reducing the refractive index. The fine particles having voids have fine voids inside and outside, and since the voids, for example, are filled with a gas such as air having a refractive index of 1.0, the refractive index can be reduced. As fine particles having such voids, inorganic or organic porous fine particles, hollow fine particles and the like can be mentioned. Specifically, porous polymer fine particles and hollow polymer fine particles formed using porous silica fine particles, hollow silica fine particles, acrylic resin and the like can be mentioned.

  The "porous silica fine particles" are silica fine particles having a porous structure, and the "hollow silica fine particles" are silica fine particles of a structure filled with a gas inside. The refractive index of the porous silica fine particles and the hollow silica fine particles is lower than the refractive index of the general silica fine particles because the refractive index is low in inverse proportion to the occupancy of the gas. Specifically, while the refractive index of general silica fine particles is about 1.45, the refractive index of porous silica fine particles and hollow silica fine particles is about 1.20 to 1.44. For this reason, porous silica fine particles and hollow silica fine particles are preferable from the viewpoint of lowering the refractive index.

  The hollow silica fine particles are not particularly limited, but hollow silica fine particles formed using the technique disclosed in, for example, JP-A-2001-233611 are preferable. The hollow silica fine particles are easy to manufacture and have high hardness of their own, and therefore, when they are mixed with a binder resin to form a low refractive index layer, the strength of the low refractive index layer can be improved.

  Further, as the fine particles, fine particles capable of forming a nanoporous structure in at least a part of the inside and / or the surface are also preferable depending on the form, structure, aggregation state, and dispersion state inside the film.

  Such fine particles are manufactured for the purpose of increasing the specific surface area, fine particles of the above-mentioned silica, release materials that allow various chemical substances to be absorbed in the packing column and the porous part of the surface, and for fixing the catalyst Examples thereof include porous fine particles to be used, and dispersions and aggregates of hollow fine particles intended to be used for heat insulating materials and low dielectric materials. Specific examples thereof include Nipsil and Nipgel manufactured by Nippon Silica Kogyo Co., Ltd., and colloidal silica UP series manufactured by Nissan Chemical Industries, Ltd., and the like.

  5 nm or more and 200 nm or less are preferable, as for the average particle diameter of the primary particle of the microparticles | fine-particles which has a space | gap, 5 nm or more and 100 nm or less are more preferable, and 10 nm or more and 80 nm or less are more preferable. If the average particle diameter of the fine particles having voids is within the above range, good transparency of the fine particles can be obtained without impairing the transparency of the low refractive index layer. Further, in the present invention, if the average particle diameter is in the above range, the fine particles may be chained.

  The fine particles having voids are preferably surface-treated. As surface treatment, surface treatment using a silane coupling agent is mentioned. Among surface treatments using a silane coupling agent, surface treatments using a silane coupling agent having a (meth) acryloyl group are preferable. By subjecting the particles to a surface treatment, the affinity with the fluorine-free photopolymerizable compound is improved, and the dispersion of the particles can be made uniform. This makes it difficult to cause aggregation of the fine particles having voids, so that the transparency of the low refractive index layer is reduced due to the increase in particle diameter, the coatability of the photocurable low refractive index layer composition, and the photocurable property is low. It is possible to suppress the decrease in the coating film strength of the composition for the refractive index layer.

  When the silane coupling agent has a (meth) acryloyl group, the silane coupling agent is photopolymerizable and thus easily crosslinks with a fluorine-free photopolymerizable compound. Thereby, the fine particles having voids are fixed in the binder resin. As a result, it is possible to impart an excellent surface hardness to the antifouling agent-containing layer while leaving the flexibility originally possessed by the binder resin. Therefore, since the low refractive index layer is denatured by utilizing the flexibility of the low refractive index layer, it is excellent in the absorbing ability against external impact and the restoring force. As a result, the occurrence of scratches can be further suppressed, and thus an optical film having more excellent scratch resistance can be provided.

  As a silane coupling agent, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxy Propylmethyldiethoxysilane, 2- (meth) acryloxypropyltrimethoxysilane, 2- (meth) acryloxypropylethoxysilane and the like can be mentioned. As a silane coupling agent, the ultraviolet curing type silane coupling agent is preferable.

  It is also preferable to use in combination with fine particles having voids and fine particles having no voids (solid fine particles). It is because the refractive index can be reduced by the fine particles having voids, and the surface hardness can be improved by the fine particles having no voids. In this case, the compounding ratio (mass ratio) of the fine particles having voids to the fine particles having no voids is preferably 1 to 15: 1, more preferably 1 to 11: 1, and still more preferably 1 to 9: 1, 1-8: 1 are particularly preferred.

  The content of the fine particles having voids is preferably 0.8 parts by mass or more and 2.5 parts by mass or less, and more preferably 0.9 parts by mass or more and 2.4 parts by mass with respect to 100 parts by mass of the fluorine-free photopolymerizable compound. Preferably, 1.0 or more and 2.3 or less are more preferable. If the content of the fine particles having voids is 0.8 parts by mass or more with respect to 100 parts by mass of the fluorine-free photopolymerizable compound, the increase in reflectance can be suppressed, and 2 with respect to 100 parts by mass of the photopolymerizable compound If it is 5 parts by mass or less, the decrease in scratch resistance can be suppressed.

<Metal fluoride>
Metal fluoride is a component for reducing the refractive index. As a metal fluoride, magnesium fluoride and sodium fluoride are mentioned, for example.

<Fluorine-free photopolymerizable compound>
The fluorine-free photopolymerizable compound is a component for improving the scratch resistance of the low refractive index layer 13. The non-fluorine-containing photopolymerizable compound does not contain a fluorine atom and has a photopolymerizable functional group. The fluorine-free photopolymerizable compound is not particularly limited, but in view of surface hardness and adhesion between the low refractive index layer and the antistatic hard coat layer, the photopolymerizable compound has two or more photopolymerizable functional groups. Compounds are preferred, and more preferred are polymerizable compounds having 3 to 9 photopolymerizable functional groups.

  Among these, when a compound having no hydroxyl group in the molecule is used as the fluorine-free photopolymerizable compound, since it is possible to further improve the saponification resistance, the molecule does not have the hydroxyl group in the molecule. Non-fluorinated photopolymerizable compounds are preferred.

  Examples of fluorine-free photopolymerizable monomers having no hydroxyl group in the molecule include hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (Meth) acrylate, difunctional (meth) acrylate such as neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trifunctional (meth) acrylate such as isocyanuric acid modified tri (meth) acrylate, pentaerythritol Examples thereof include tetrafunctional (meth) acrylates such as tetra (meth) acrylate, and hexafunctional (meth) acrylates such as dipentaerythritol hexa (meth) acrylate.

  As non-fluorine-containing photopolymerizable oligomers and prepolymers having no hydroxyl group in the molecule, polyester (meth) acrylates, urethane (meth) acrylates, polyester-urethane (meth) acrylates, polyether (meth) acrylates, polyols Examples include (meth) acrylate, melamine (meth) acrylate, isocyanurate (meth) acrylate, epoxy (meth) acrylate and the like.

  As the non-fluorine-containing photopolymerizable compound, it is most preferable from the viewpoint of saponification resistance that the non-fluorine-containing photopolymerizable compound does not have a hydroxyl group in the molecule. However, within the range that does not impair the saponification resistance, it is possible to use a non-fluorine-containing photopolymerizable compound having a hydroxyl group in the molecule for adjusting physical properties such as scratch resistance and coating suitability. . In this case, as a non-fluorine-containing photopolymerizable compound having a hydroxyl group in the molecule from the viewpoint of scratch resistance, a non-fluorine-containing photopolymerizable compound having two or more photopolymerizable functional groups (polyfunctional fluorine-free Photopolymerizable compounds) are preferred.

  As a polyfunctional fluorine-free photopolymerizable monomer having one hydroxyl group in the molecule, trimethylolpropane di (meth) acrylate (TMPDA), pentaerythritol tri (meth) acrylate (PETA), dipentaerythritol penta ( Meta) acrylate (DPPA) etc. are mentioned. Further, as a polyfunctional fluorine-free photopolymerizable monomer having two hydroxyl groups in the molecule, dipentaerythritol tetra (meth) acrylate (DPTA) can be mentioned.

  Thus, in the case of a polyfunctional fluorine-free photopolymerizable compound having a hydroxyl group in the molecule, one having a large proportion of the hydroxyl group in the molecule is not preferable in view of saponification resistance. Therefore, it is preferable that the proportion of the hydroxyl group in the total amount of the photocurable low refractive index layer composition be as small as possible, because the saponification resistance can be improved more surely.

  Therefore, in the present embodiment, in the case of a polyfunctional fluorine-free photopolymerizable compound having a hydroxyl group in the molecule, the hydroxyl group contained in one molecule as an index of the ratio of the hydroxyl group (OH group) in the molecule The value obtained by dividing the number of H by the molecular weight by 100 times is defined as "hydroxyl group content".

  Here, to give a specific example of the hydroxyl group content, the above-mentioned pentaerythritol tri (meth) acrylate (PETA) has an OH group number of 1, a molecular weight of 298 and 0.33, and dipentaerythritol pentaacrylate (DPPA) has an OH group number And a molecular weight of about 550 and 0.18.

  The hydroxyl group content is preferably 0.2 or less. By using a compound having a hydroxyl group content of 0.2 or less as the number of hydroxyl groups contained in one molecule as the polyfunctional fluorine-free photopolymerizable compound, preferable saponification resistance can be obtained. The hydroxyl group content is an index for one molecule, but when the composition for the photocurable low refractive index layer is a mixture of a plurality of polyfunctional fluorine-free photopolymerizable compounds, the plurality of polyfunctional fluorine-free compounds are included. As a whole of the photopolymerizable compound, it is preferable to set the hydroxyl group content to 0.2 or less. When the molecular weight of the polyfunctional fluorine-free photopolymerizable compound is not single but has a distribution, a weight average molecular weight is used as the molecular weight in the above formula.

  The molecular weight of the polyfunctional fluorine-free photopolymerizable compound contained in the photocurable low refractive index layer composition is preferably 300 to 1,000 from the viewpoint of scratch resistance. If the molecular weight is too small or too large, the scratch resistance is reduced.

  In addition, in the composition for a photocurable low refractive index layer, for the purpose of adjusting physical properties and the like, in addition to the polyfunctional fluorine-free photopolymerizable compound, one photopolymerizable having no hydroxyl group in the molecule You may use together the fluorine non-containing photopolymerizable compound (monofunctional fluorine non-containing photopolymerizable compound) which has a functional group. Examples of monofunctional polymerizable monomers having no hydroxyl group in the molecule include methyl (meth) acrylate, ethyl (meth) acrylate, methylhexyl (meth) acrylate, ethylhexyl (meth) acrylate and the like.

(2) Composition Containing Fluorine-Containing Photopolymerizable Compound <Fluorine-Containing Photopolymerizable Compound>
The fluorine-containing photopolymerizable compound is a component for reducing the refractive index. The fluorine-containing photopolymerizable compound contains a fluorine atom and has a photopolymerizable functional group. Examples of fluorine-containing photopolymerizable compounds include fluoroolefins (eg fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluorobutadiene, perfluoro-2,2-dimethyl-1,3-dioxole, etc. Can be mentioned. As those having a (meth) acryloyloxy group, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- (perfluorobutyl) ) Ethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2- (perfluorodecyl) ethyl (meth) acrylate, α-trifluoro (Meth) acrylate compounds having a fluorine atom in the molecule, such as methyl methacrylate and α-trifluoroethyl methacrylate, or a fluoroalkyl group having 1 to 14 carbon atoms, having at least 3 fluorine atoms in the molecule, A fluorocycloalkyl group or a fluoroalkylene group, and at least two There are also fluorine-containing polyfunctional (meth) acrylic acid ester compounds having a (meth) acryloyloxy group and the like.

  The compositions (1) to (3) may contain a thermosetting resin that can be cured by heat, and a thermoplastic resin that is not cured by light or heat. The thermosetting resin may, for example, be a urethane resin, a melamine resin, a phenol resin or a silicone resin. The thermoplastic resin may, for example, be an acrylic resin, a thermoplastic urethane resin, a polyamide resin or a styrene resin. Cellulose resin, polycarbonate resin, vinyl resin, silicone resin etc. are mentioned. Examples of the cellulose-based resin include nitrocellulose, acetyl cellulose, cellulose acetate propionate, and ethyl hydroxyethyl cellulose.

  Furthermore, the composition of said (1)-(3) may be made to contain a polymerization initiator and a solvent. As the polymerization initiator and the solvent, the compounds described in the section of the composition for antistatic hard coat layer can be used. In addition, various known additives may be added to adjust physical properties such as coating suitability and dispersion stability of the low refractive index forming agent. As such an additive, a leveling agent, a dispersion stabilizer, an antistatic agent, an ultraviolet absorber, an antioxidant, a refractive index regulator etc. are mentioned, for example.

<< Physical Properties of Optical Film >>
The surface resistance value of the optical film 10 before the saponification treatment is 1 × 10 ¹¹ Ω / sq or less, and more preferably 1 × 10 ¹⁰ Ω / sq or less from the viewpoint of obtaining more excellent antistatic properties. The ratio of the surface resistance of the optical film after saponification to the surface resistance of the optical film before saponification (the surface resistance after saponification / the surface resistance before saponification) is 500 or less preferable. The saponification treatment is carried out by immersing the optical film in a 40 ° C. to 70 ° C. NaOH or KOH aqueous solution adjusted to 1.5 to 4.5 N for 15 seconds to 5 minutes. As an apparatus which can be used for the measurement of surface resistance value, Hiresta UP-HT450 made from Mitsubishi Chemical Analytech Co., Ltd. etc. is mentioned.

  The total light transmittance of the optical film 10 before the saponification treatment is preferably 90% or more, more preferably 92% or more, from the viewpoint of obtaining excellent light transmittance. In addition, even after the saponification treatment, the total light transmittance of the optical film 10 is preferably 90% or more, and more preferably 92% or more. The total light transmittance is measured in accordance with JIS K7361. As an apparatus which can be used for measurement of total light transmittance, HM-150 made by Murakami Color Research Laboratory, etc. may be mentioned.

  The haze value of the optical film 10 before the saponification treatment is preferably 1.0% or less, more preferably 0.7% or less, from the viewpoint of obtaining excellent transparency. In addition, even after the saponification treatment, the haze value of the optical film 10 is preferably 1.0% or less, and more preferably 0.7% or less. The haze value is measured in accordance with JIS K7136. As an apparatus which can be used for measurement of a total light transmittance and a haze value, HM-150 etc. made from Murakami Color Research Laboratory are mentioned.

The steel wool abrasion resistance of the optical film 10 before saponification treatment is determined by using the surface of the low refractive index layer when the low refractive index layer is provided and the antistatic hard coat layer when the low refractive index layer is not provided. It is preferable that the surface is scratched when rubbed back and forth 10 times at a speed of 100 mm / sec while applying load using steel wool # 0000 (product name: Bonstar, manufactured by Nippon Steel Wool Co., Ltd.). In this case, it is preferable that no damage occurs at a load of 300 g / cm ² , and more preferably no damage occurs at a load of 500 g / cm ² or more. In addition, even after the saponification treatment, the optical film preferably has the same steel wool abrasion resistance as that before the saponification treatment.

  Such an optical film 10 can be obtained, for example, by the following method. First, the coating 16 of the composition for antistatic hard coat layer is formed on the light transmitting substrate 11 (FIG. 3A). The coating film 16 of the composition for antistatic hard coat layer can be formed by applying the composition for antistatic hard coat layer on the light transmitting substrate 11. Examples of the method for applying the composition for hard coat layer include known coating methods such as spin coating, dipping, spraying, slide coating, bar coating, roll coating, gravure coating, and die coating.

  When the coating film 16 of the composition for antistatic hard coat layer is formed on the light transmitting substrate 11, a part of the permeable solvent and a part of the first acrylate monomer are formed on the upper part of the light transmitting substrate 1. The second acrylate monomer penetrates, and as shown in FIG. 3A, the permeation region 11B which becomes the mixed region 11A after curing is formed on the light transmissive substrate 11. The antistatic agent 14 and the photopolymerizable urethane oligomer do not penetrate into the light transmitting substrate 11 because the weight average molecular weight is large.

Next, for example, the coating film 16 is dried at 30 ° C. or more and 100 ° C. or less for 15 seconds or more. This removes the permeable solvent. After the coating film 16 is dried, for example, light is irradiated to the coating film 16 so that the integrated light quantity is 10 mJ / cm ² or more and 100 mJ / cm ² or less to semi-cure (half cure) the coating film (FIG. 3B) ). Here, as the "light" irradiated to the coating film when curing the "coating film" in the present specification, visible light, and ultraviolet light, X-ray, electron beam, alpha ray, beta ray, and gamma ray Such ionizing radiation is mentioned. In addition, “semi-curing” refers to curing when the coating of the composition for antistatic hard coat layer is further heated and / or the coating of the composition for antistatic hard coat layer is further irradiated with light. Means substantially progressing state.

  When ultraviolet light is used as light for semi-curing the coating film 16, ultraviolet light emitted from an ultrahigh pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc, xenon arc, metal halide lamp, etc. can be used. As a wavelength of an ultraviolet-ray, the wavelength range of 190 to 380 nm can be used. Among these, a high pressure mercury lamp is preferable, and the thickness of the mixed region can be adjusted to a desired thickness by the range of the above-mentioned wavelength range.

  When the coating film 16 is semi-cured, mainly, the photopolymerizable urethane oligomer, the first acrylate monomer, and the second acrylate monomer are crosslinked, but the methacrylate monomer is inferior in reactivity, so it is not crosslinked. In the coating film 16 as a methacrylate monomer.

  Next, a coating 17 of the composition for a photocurable low refractive index layer is formed on the semi-cured coating 16 (FIG. 4A). The coating film 17 of the photocurable low refractive index layer composition can be formed by the same method as the coating film 16 of the antistatic hard coat layer composition.

Thereafter, light is irradiated to the coating films 16 and 17 so that, for example, the integrated light amount is 100 mJ / cm ² or more and 500 mJ / cm ² or less, and the coating films 16 and 17 are completely cured (full cure) (FIG. 4B). In the present specification, "completely cured" means that the coating of the composition for antistatic hard coat layer and the coating of the composition for photocurable low refractive index layer are further heated and / or further applied to these coatings. Even when irradiated with light, it means that curing does not substantially proceed, and as a result of curing, it has a desired hardness. As a result, the mixed region 11A, the antistatic hard coat layer 12 and the low refractive index layer 13 are formed, and the optical film 10 shown in FIG. 1 can be obtained.

  In the above method, after the coating film 16 is semi-cured, the coating film 17 for the photocurable low refractive index layer composition is formed on the semi-cured coating film 16 and then the coatings 16, 17 Is fully cured, which is a desirable form, and is fully cured of the coating 16 to form the antistatic hardcoat layer 12 and then photocurable low refractive index on the antistatic hardcoat layer 12 A coating 17 of the layer composition may be formed, and the coating 17 may be completely cured.

  Although the above method describes the method for producing the optical film 10 provided with the low refractive index layer 13, when an optical film not provided with the low refractive index layer is to be obtained, the composition for the antistatic hard coat layer After forming a coating of the article, the coating is completely cured.

In the optical film 10 of the present embodiment, the antistatic agent 14 is present in the upper region R having a depth of 0.2 μm or more and less than 2.0 μm from the surface 12A of the antistatic hard coat layer 12. The surface resistance value of the optical film 10 can be 1 × 10 ¹¹ Ω / □ or less. In addition, since the antistatic agent 14 is not present on the surface 12 A of the antistatic hard coat layer 12, even when the optical film 10 is subjected to the saponification treatment, the antistatic agent 14 is unlikely to come off. Therefore, even when the optical film 10 having a surface resistance value of 1 × 10 ¹¹ Ω / □ or less is subjected to a saponification treatment, the reduction of the surface resistance value can be suppressed and the excellent antistatic property can be maintained. In addition, even when the optical film 10 is subjected to a saponification treatment, the antistatic agent 14 is unlikely to come off, so excellent scratch resistance can be maintained. Thus, it is possible to provide the optical film 10 capable of maintaining excellent antistatic property and scratch resistance even when saponification treatment is performed.

In the present embodiment, the antistatic hard coat layer 12 includes the antistatic agent 14, the photopolymerizable urethane oligomer, the first acrylate monomer, the second acrylate monomer, and the permeable solvent. And the surface resistance value of the optical film 10 can be made 1 × 10 ¹¹ Ω / □ or less, and the antistatic agent 14 is formed in the upper region. It can be present in R. This is considered to be due to the following reasons. That is, since the second acrylate monomer has a structure having a smaller weight average molecular weight and more linear portions as compared to the first acrylate monomer, the antistatic hard coat is formed on the light transmitting substrate 11 When the coating 16 of the layer composition is formed, the second acrylate monomer penetrates the light transmitting substrate 11 before the first acrylate monomer. On the other hand, the first acrylate monomer moves to the light transmitting substrate 11 by the action of the permeable solvent, but the first acrylate monomer has a slightly larger molecular weight and is molecularly structurally higher than the second acrylate monomer. Because it is also bulky, it does not penetrate the light transmitting substrate 11 more easily than the second acrylate monomer. For this reason, part of the first acrylate monomer penetrates the light transmitting substrate 11, but most of the first acrylate monomer does not penetrate and exists in the lower part in the coating film 16, resulting in antistatic The agent 14 will be present on top of the coating 16. Thus, since the antistatic agent 14 comes to exist in the upper part of the coating film 16, the surface resistance value of the optical film 10 can be 1 * 10 < ¹¹ > ohms / square or less. On the other hand, a composition containing an antistatic agent, a photopolymerizable urethane oligomer, a first acrylate monomer, and a second acrylate monomer, and an antistatic agent, a first acrylate monomer, which does not contain a photopolymerizable urethane oligomer, and When an experiment was conducted to form an antistatic hard coat layer using a composition containing each of the acrylate monomers of No. 2, the antistatic hard coat layer formed using a composition containing a photopolymerizable urethane oligomer The surface resistance value and the scratch resistance after saponification treatment were superior to those of a hard coat layer formed using a composition containing no photopolymerizable urethane oligomer. The reason for this is not clear, but due to the difference in molecular structure between the photopolymerizable urethane oligomer and the antistatic agent, the photopolymerizable urethane oligomer is easier to be positioned on the surface side of the antistatic hard coat layer than the antistatic agent. It is guessed that it is from. And from this experimental result, it can be inferred that the antistatic agent is not present on the surface of the antistatic hard coat layer. Therefore, by using the composition for antistatic hard coat layer containing at least the photopolymerizable urethane oligomer, the first acrylate monomer, the second acrylate monomer, and the permeable solvent, the antistatic can be prevented. The agent 14 can be present in the upper region R.

  An antistatic hard coat layer 12 comprising an antistatic agent 14, the photopolymerizable urethane oligomer, the first acrylate monomer, the second acrylate monomer, and the permeable solvent. Since the coating layer composition is used, the generation of interference fringes can be suppressed, and excellent hardness can be obtained. That is, it has been conventionally recognized that the use of a (meth) acrylate monomer having a weight average molecular weight of less than 1000 as the (meth) acrylate monomer for forming the binder resin can suppress the occurrence of interference fringes. That is, the first acrylate monomer and the second acrylate monomer are considered to be equivalent from the viewpoint of suppressing the occurrence of interference fringes. However, in fact, even when a (meth) acrylate monomer having a weight average molecular weight of less than 1000 was used, the occurrence of interference fringes could not be suppressed. For example, when only the first acrylate monomer is used as a (meth) acrylate monomer having a weight average molecular weight of less than 1000, the first acrylate monomer penetrates the light transmitting substrate, but the first transparent monomer penetrates. The acrylate monomer causes a new interface to be generated, and the generation of interference fringes could not be prevented. On the other hand, when the second acrylate monomer is contained as a (meth) acrylate monomer having a weight average molecular weight of less than 1000, interference fringes can be prevented, but on the other hand, the mixed region becomes soft and hardness Cause a drop in Here, with regard to the problem of hardness, the use of the first acrylate monomer gives a crosslinker harder than the use of the second acrylate monomer, but the use of only the first acrylate monomer results in light transmission. When the material penetrates into the base material too much, the thickness of the mixed region becomes thick, and as a result, the region other than the mixed region in the light transmitting substrate becomes thin, so that the strength of the light transmitting substrate is lowered. On the other hand, when the first acrylate monomer and the second acrylate monomer are used in combination as in the present embodiment, the generation of interference fringes can be suppressed by the action of the second acrylate monomer. Furthermore, since the second acrylate monomer penetrates the light transmitting substrate 11 earlier than the first acrylate monomer, excessive penetration of the first acrylate monomer can be suppressed. As a result, the thickness of the mixed area 11A can be reduced, and therefore the hardness can be improved. Further, as described above, since the crosslinked product of the photopolymerizable urethane oligomer can be present on the surface 12A of the antistatic hard coat layer 12, the hardness on the surface 12A can be improved. As a result, even when the antistatic hard coat layer 12 having a very thin film thickness of 4 μm to 10 μm is formed, excellent hardness can be obtained.

Moreover, conventionally, it has been difficult to stably provide an optical film having a surface resistance value of 1 × 10 ¹¹ Ω / □ or less before the saponification treatment. On the other hand, in the present embodiment, the antistatic property including the antistatic agent 14, the photopolymerizable urethane oligomer, the first acrylate monomer, the second acrylate monomer, and the permeable solvent. Since the antistatic hard coat layer 12 is formed using the composition for hard coat layer, the antistatic agent 14 can be present in the upper region R as described above. Thereby, an optical film having a surface resistance value of 1 × 10 ¹¹ Ω / □ or less before the saponification treatment can be stably provided.

  In the present embodiment, the antistatic hard coat layer 12 includes two or more of the antistatic agent 14, the photopolymerizable urethane oligomer, the first acrylate monomer, the second acrylate monomer, and the like. Since the composition for antistatic hard coat layer containing a methacrylate monomer having a weight average molecular weight of 300 or more and 1,000 or less having a methacryloyl group and a penetrating solvent, the above effect is not inhibited Furthermore, the adhesion between the antistatic hard coat layer 12 and the low refractive index layer 13 can be further improved. That is, when the methacrylate monomer is contained in addition to the first acrylate monomer etc., the methacrylate monomer is inferior in reactivity, so the coating 16 of the composition for antistatic hard coat layer is semi-cured If it is allowed to crosslink, it does not crosslink and remains as it is. Then, after forming the coating film 17 of the photocurable low refractive index layer composition, when the coating films 16 and 17 are completely cured, the methacrylate monomer remaining in the semi-cured coating film 16 is Since it crosslinks with the fluorine-free photopolymerizable compound and the fluorine-containing photopolymerizable compound contained in the coating film 17, the adhesion between the antistatic hard coat layer 12 and the low refractive index layer 13 can be further improved. . Further, the photopolymerizable urethane oligomer is also a component capable of improving the adhesion between the antistatic hard coat layer 12 and the low refractive index layer 13, but in the present embodiment, the photopolymerizable urethane oligomer is used as the surface. Since it can be made to exist, the adhesion between the antistatic hard coat layer 12 and the low refractive index layer 13 can be further improved in addition to the above effect of the methacrylate monomer.

<<< polarizing plate >>>
The optical film 10 can be used, for example, by being incorporated into a polarizing plate. FIG. 5 is a schematic configuration view of a polarizing plate incorporating the optical film according to the present embodiment. As shown in FIG. 5, the polarizing plate 20 includes an optical film 10, a polarizer 21, and a protective film 22. The optical film 10 is subjected to a saponification treatment to improve the adhesion to the polarizer 21.

  The polarizer 21 is formed on the surface of the light transmitting substrate 11 opposite to the surface on which the antistatic hard coat layer 12 is formed. The protective film 22 is provided on the surface of the polarizer 21 opposite to the surface on which the optical film 10 is provided. The protective film 22 may be a retardation film.

  Examples of the polarizer 21 include, for example, a polyvinyl alcohol film, a polyvinyl formal film, a polyvinyl acetal film, and an ethylene-vinyl acetate copolymer-based saponified film which is dyed with iodine or the like and stretched.

<<< Method of manufacturing polarizing plate >>>
Such a polarizing plate 20 can be obtained, for example, by the following method. First, the optical film 10 is saponified with an aqueous alkaline solution. Specifically, the saponification treatment is performed by immersing the optical film 10 in a 40 ° C. to 70 ° C. NaOH or KOH aqueous solution adjusted to 1.5 to 4.5 N for 15 seconds to 5 minutes.

  Thereafter, the polarizer 21 is formed on the surface of the light transmitting substrate 11 of the optical film 10 subjected to the saponification treatment, which is opposite to the surface on which the antistatic hard coat layer 12 is formed. Moreover, the protective film 22 in which the saponification process was performed is provided in the surface on the opposite side to the surface in which the optical film 10 of the polarizer 21 is provided. Thereby, the polarizing plate 20 can be obtained.

  According to the present embodiment, since the optical film 10 is saponified, the antistatic property and scratch resistance of the antistatic hard coat layer can be maintained even after the saponification. Thereby, the polarizing plate excellent in antistatic property and abrasion resistance can be provided.

<<< Liquid crystal panel >>>
The optical film 10 and the polarizing plate 20 can be incorporated into a liquid crystal panel and used. FIG. 6 is a schematic configuration view of a liquid crystal panel incorporating the optical film according to the present embodiment.

  The liquid crystal panel 30 shown in FIG. 6 is a protective film 31 such as a triacetyl cellulose film (TAC film), a polarizer 32, a retardation film 33, and adhesion from the light source side (backlight unit side) to the viewer side. An agent layer 34, a liquid crystal cell 35, an adhesive layer 36, a retardation film 37, a polarizer 21 and an optical film 10 are laminated in this order. The liquid crystal cell 35 has a liquid crystal layer, an alignment film, an electrode layer, a color filter and the like disposed between two glass substrates.

  Examples of the retardation films 33 and 37 include triacetyl cellulose films and cycloolefin polymer films. The retardation film 37 may be identical to the protective film 22. Adhesives that make up the adhesive layers 34, 36 include pressure sensitive adhesives (PSAs).

<<< image display device >>>
The optical film 10, the polarizing plate 20, and the liquid crystal panel 30 can be incorporated into an image display device and used. Examples of the image display device include a liquid crystal display (LCD), a cathode ray tube display (CRT), a plasma display (PDP), an electroluminescence display (ELD), a field emission display (FED), a touch panel, a tablet PC, electronic paper and the like. It can be mentioned. FIG. 7 is a schematic configuration view of a liquid crystal display as an example of the image display device incorporating the optical film according to the present embodiment.

  The image display device 40 shown in FIG. 7 is a liquid crystal display. The image display device 40 is configured of a backlight unit 41 and a liquid crystal panel 30 provided with the optical film 10, which is disposed closer to the viewer than the backlight unit 41. As the backlight unit 41, a known backlight unit can be used.

Second Embodiment
Hereinafter, an optical film according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a schematic configuration view of an optical film according to the present embodiment, FIG. 9 is an enlarged view around the upper region of the optical film according to the present embodiment, and FIGS. 10 and 11 are optical films according to the present embodiment. It is the figure which showed typically the manufacturing process of.

<<< Optical film >>>
As shown in FIG. 8, the optical film 50 includes the light transmitting substrate 51, the antistatic hard coat layer 52 provided on the light transmitting substrate 51, and the charge as in the first embodiment. A low refractive index layer 53 provided on the preventing hard coat layer 52 and adjacent to the antistatic hard coat layer 52 is provided. Further, as in the first embodiment, a mixed region 51A is formed in the vicinity of the interface of the antistatic hard coat layer 52 in the light transmitting substrate 51, as shown in FIG. The optical film 50 may not have the low refractive index layer 53. The light transmitting substrate 51 and the low refractive index layer 53 are the same as the light transmitting substrate 11 and the low refractive index layer 13 described in the first embodiment, and thus the description thereof is omitted here.

<< Mixed area >>
The mixed region 51A includes a light transmitting base material 51, and a permeation including the first acrylate monomer and the second acrylate monomer which has penetrated the light transmitting base material 51 from the composition for an antistatic agent-containing hard coat layer described later. And cured products. The thickness of the mixed area 51A is the same as the thickness of the mixed area 11A.

<< Antistatic Hard Coat Layer >>
The antistatic hard coat layer 52 has a thickness of 4 μm to 10 μm. The upper limit of the film thickness of the antistatic hard coat layer 52 is preferably 8 μm or less. The film thickness of the antistatic hard coat layer 52 can be measured by the same method as the film thickness of the antistatic hard coat layer 12 described above.

  The antistatic hard coat layer 52 is provided on the antistatic agent-containing hard coat layer 54 including the antistatic agent 54A and the first binder resin 54B, and on the antistatic agent-containing hard coat layer 54, and the antistatic agent-containing hard coat layer The hard coat layer 55 is in close contact with the coat layer 54, contains no antistatic agent, and contains an antistatic agent-free hard coat layer 55 containing the second binder resin 55A.

  The film thickness of the antistatic agent-containing hard coat layer 54 is preferably more than 2.5 μm and not more than 9.8 μm. From the viewpoint of obtaining excellent hardness in the antistatic hard coat layer 54, the thickness of the antistatic agent-containing hard coat layer 54 is more preferably more than 2.5 μm and 7.8 μm or less.

  Antistatic agent 54A is not present on surface 52A of antistatic hardcoat layer 52 (surface of antistatic agent-free hardcoat layer 55), as shown in FIG. The depth from the surface 52A of the upper surface R is within the upper region R of 0.2 μm or more and less than 2.0 μm. Here, the interface IF between the antistatic agent-containing hard coat layer 54 and the antistatic agent-free hard coat layer 55 is present in the upper region R.

  The antistatic agent 54A is preferably localized in the upper region R. Preferably, the antistatic agent 54A is localized in the upper region R at a ratio of 75% by mass or more based on the total amount of the antistatic agent present in the antistatic agent-containing hard coat layer 54.

  The film thickness of the antistatic non-containing hard coat layer 55 is preferably 0.2 μm or more and less than 1.5 μm. Further, the film thickness of the antistatic non-containing hard coat layer 55 is 0.3 μm or more from the viewpoint of further suppressing the dropping of the antistatic agent due to the saponification treatment and maintaining the excellent scratch resistance before and after the saponification treatment. Preferably, it is less than 5 μm.

[Antistatic agent]
Since the antistatic agent 54A is the same as the antistatic agent 14 described in the first embodiment, the description will be omitted here.

<First binder resin>
The first binder resin 54B of the present embodiment is a cured product of a mixture containing at least the first acrylate monomer and the second acrylate monomer described in the first embodiment.

  About the said 1st acrylate monomer and said 2nd acrylate monomer, since it is the same as that of what was demonstrated by 1st Embodiment except the following, description shall be abbreviate | omitted.

<Second binder resin>
The second binder resin 55A of this embodiment is a cured product of the photopolymerizable urethane oligomer described in the first embodiment, or a mixture containing at least the photopolymerizable urethane oligomer and the first acrylate monomer. It is a cured product.

  The antistatic agent-containing hard coat layer 54 is a layer formed of a cured product of the composition for the antistatic agent-containing hard coat layer. The composition for an antistatic agent-containing hard coat layer contains an antistatic agent 54A, the first acrylate monomer, and the second acrylate monomer, the permeable solvent, and the polymerization initiator. The composition for an antistatic agent-containing hard coat layer may contain an antistatic agent, the first acrylate monomer, the second acrylate monomer, and the permeable solvent, and does not contain a polymerization initiator. It is good. In addition, since the permeable solvent and the polymerization initiator are the same as the permeable solvent and the polymerization initiator described in the first embodiment, the description is omitted here. Further, if necessary, the composition for an antistatic agent-containing hard coat layer may contain a permeation suppression solvent, a lubricant, a dispersant, and the like.

  In the composition for an antistatic agent-containing hard coat layer, from the viewpoint of ensuring that the antistatic agent 54A is present in the upper region R, from the viewpoint of reliably suppressing the occurrence of interference fringes, and from the viewpoint of obtaining excellent hardness. The antistatic agent 54A is 0.01% by mass or more and 6% by mass or less, and the first acrylate monomer is 5% by mass or more and 52% by mass with respect to the total mass of the total solid content of the composition for antistatic hard coat layer Hereinafter, the second acrylate monomer is preferably contained in a proportion of 5% by mass or more and 50% by mass or less.

  The antistatic agent non-containing hard coat layer 55 is a layer formed of a cured product of the antistatic agent non-containing hard coat layer composition. The composition for an antistatic agent-free hard coat layer contains the above-mentioned photopolymerizable urethane oligomer, a solvent and a polymerization initiator. The composition for an antistatic agent-free hard coat layer may contain the above-described photopolymerizable urethane oligomer, and may not contain a solvent and a polymerization initiator.

<< Physical Properties of Optical Film >>
The surface resistance value of the optical film 50 before the saponification treatment is 1 × 10 ¹¹ Ω / sq or less, and more preferably 1 × 10 ¹⁰ Ω / sq or less from the viewpoint of obtaining more excellent antistatic properties.

  Such an optical film 50 can be obtained, for example, by the following method. First, the composition for the antistatic agent-containing hard coat layer and the composition for the antistatic agent-free hard coat layer are prepared.

  Next, the light transmitting group is made such that the coating 56 of the composition for the antistatic agent-containing hard coat layer is closer to the light transmitting substrate 51 than the coating 57 of the composition for the non-static agent-containing hard coating layer. The coating film 56 of the composition for an antistatic agent-containing hard coat layer and the coating film 57 of the composition for an antistatic agent-free hard coat layer are formed on the material 51 (FIG. 10A).

  The composition for an antistatic agent-containing hard coat layer is coated on a light transmitting substrate 51 to form a coating film 56 of the composition for an antistatic agent-containing hard coat layer. The coated films 56 and 57 may be formed by applying the hard coat layer composition containing the composition to form the coating film 57 of the composition for a hard coat layer not containing an antistatic agent, but from the viewpoint of productivity It is preferable to form the coating films 56 and 57 by the simultaneous multilayer coating method. That is, the light transmitting group is made such that the coating 56 of the composition for the antistatic agent-containing hard coat layer is closer to the light transmitting substrate 51 than the coating 57 of the composition for the non-static agent-containing hard coating layer. It is preferable to simultaneously apply the composition for an antistatic agent-containing hard coat layer and the composition for an antistatic agent-free hard coat layer on the material 51 to simultaneously form the coating films 56, 57.

  When the coating 56 of the composition for an antistatic agent-containing hard coat layer is formed on the light transmitting substrate 51, a part of the permeable solvent and a part of the first acrylate monomer are formed on the upper part of the light transmitting substrate 51. The second acrylate monomer penetrates, and a penetration region 51B which becomes the mixed region 51A after curing is formed on the upper part of the light transmitting substrate 51.

Then, after the coated films 56 and 57 are dried, light is irradiated to the coated films 56 and 57 so that the integrated light amount is, for example, 10 mJ / cm ² or more and 200 mJ / cm ² or less, and the coated films 56, 57 Is cured (complete curing) (FIG. 10B). Thus, the antistatic agent-containing hard coat layer 54 and the antistatic agent-free hard coat layer 55 are formed, and the antistatic hard coat layer 52 is formed.

  After the antistatic hard coat layer 52 is formed, a coating 58 of a photocurable low refractive index layer composition is formed on the antistatic hard coat layer 52 (FIG. 11A). The photocurable low refractive index layer composition is the same as the photocurable low refractive index layer composition described in the first embodiment, and thus the description thereof is omitted here.

Thereafter, the coating film 58, for example, integrated light quantity to cure the coating film 58 is irradiated with light so that 70 mJ / cm ² or more 200 mJ / cm ² or less (FIG. 11B). Thereby, the low refractive index layer 53 is formed on the antistatic hard coat layer 52, and the optical film 50 shown in FIG. 8 is obtained.

  In the above, after the coatings 56 and 57 are completely cured, the coating 58 of the photocurable low refractive index layer composition is formed, and thereafter the coating 58 is cured. After 57 is semi-cured, a coating 58 of the photocurable low refractive index layer composition may be formed on the semi-cured coating 57, and then the coatings 56 to 58 may be completely cured.

In optical film 50 according to the present embodiment, antistatic agent 54A is present in upper region R having a depth from surface 52A of antistatic hard coat layer 52 of not less than 0.2 μm and less than 2.0 μm. The surface resistance value of the optical film 50 can be 1 × 10 ¹¹ Ω / □ or less. Further, since the antistatic agent 54A is not present on the surface 52A of the antistatic hard coat layer 52, even when the optical film 50 is subjected to a saponification treatment, the antistatic agent 54A is unlikely to come off. Therefore, even when the optical film 50 having a surface resistance value of 1 × 10 ¹¹ Ω / □ or less is subjected to a saponification treatment, the reduction of the surface resistance value can be suppressed, and the excellent antistatic property can be maintained. In addition, even when the optical film 50 is subjected to a saponification treatment, the antistatic agent 54A is unlikely to come off, so excellent scratch resistance can be maintained. Thus, it is possible to provide the optical film 50 capable of maintaining excellent antistatic property and scratch resistance even when saponification treatment is performed.

In the present embodiment, the antistatic agent-containing hard coat layer 54 is composed of the antistatic agent-containing hard coat layer 54 and the antistatic agent-free hard coat layer 55, but even with such a configuration, The surface resistance value of the optical film 50 can be 1 × 10 ¹¹ Ω / □ or less, and the antistatic agent 54A can be present in the upper region R.

  Since the antistatic agent-containing hard coat layer 54 is formed using the composition for an antistatic agent-containing hard coat layer containing the first acrylate monomer, the second acrylate monomer, and the permeable solvent. For the same reason as in the first embodiment, the generation of interference fringes can be suppressed, and excellent hardness can be obtained.

In addition, an antistatic agent-containing hard coat layer 54 is formed using the composition for an antistatic agent-containing hard coat layer containing the first acrylate monomer, the second acrylate monomer, and the permeable solvent. Accordingly, as in the first embodiment, it is possible to stably provide the optical film 50 having a surface resistance value of 1 × 10 ¹¹ Ω / □ or less before the saponification treatment.

  In the present embodiment, since the antistatic agent non-containing hard coat layer 55 is formed using the antistatic agent non-containing hard coat layer composition containing a photopolymerizable urethane oligomer, the low refractive index layer 53 and The adhesion of the above can be improved.

  EXAMPLES The present invention will be described by way of examples to describe the present invention in detail, but the present invention is not limited to these descriptions.

<Preparation of composition for antistatic hard coat layer>
Each component was blended so as to have the composition shown below to obtain a composition for antistatic hard coat layer.
(Composition 1 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 29 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., 2 Functionality, weight average molecular weight 302): 32 parts by mass · methyl ethyl ketone: 100 parts by mass (penetrating solvent)
Polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition for antistatic hard coat layer 2)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 45 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., 2 Functionality, weight average molecular weight 302): 16 parts by mass · methyl ethyl ketone (penetrable solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition for antistatic hard coat layer 3)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 19 parts by mass tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., 2 Functionality, weight average molecular weight 302): 42 parts by mass · methyl ethyl ketone (penetrable solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition for antistatic hard coat layer 4)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 57 parts by mass Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 19 parts by mass tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., 2 Functionality, weight average molecular weight 302): 22 parts by mass · methyl ethyl ketone (penetrable solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 5 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 0.1 parts by mass (solid) Minute conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37.6 parts by mass-Dipentaerythritol hexaacrylate (No. Acrylate monomer No. 1, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 29.7 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, Toho Synthetic Equity Made in the company, bifunctional, weight average molecular weight 302): 32.6 parts by mass · methyl ethyl ketone (penetrating solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 6 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 0.3 parts by mass (solid) Minute conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37.6 parts by mass-Dipentaerythritol hexaacrylate (No. Acrylate monomer No. 1, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 29.6 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name "M-240", Toho Synthetic Equity Made by company, bifunctional, weight average molecular weight 302): 32.5 parts by mass · methyl ethyl ketone (penetrable solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 7 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000, manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 3 parts by mass (solids equivalent value) )
· Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 36.5 parts by mass · Dipentaerythritol hexaacrylate (No. Acrylate monomer No. 1, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 28.5 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240, Toagosei Co., Ltd. Product, bifunctional, weight average molecular weight 302): 32.0 parts by mass · methyl ethyl ketone (penetrable solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition for antistatic hard coat layer 8)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 6 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight: 4,000): 36.0 parts by mass-Dipentaerythritol hexaacrylate (No. Acrylate monomer No. 1, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 27.0 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name "M-240", Toho Synthetic Equity Made by company, bifunctional, weight average molecular weight 302): 31.0 parts by mass · methyl ethyl ketone (penetrable solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 9 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "Corcoat NR121X", manufactured by Corcoat Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion) value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight: 4,000): 37.0 parts by mass-Pentaerythritol tetraacrylate (first Acrylate monomer, product name “M-450”, manufactured by Toagosei Co., Ltd., tetrafunctional, weight average molecular weight 400): 29.0 parts by mass tetraethylene glycol diacrylate (second acrylate monomer, product name “M- 240 ", manufactured by Toagosei Co., Ltd., bifunctional, weight average molecular weight 302): 32.0 parts by mass · methyl ethyl ketone (penetrating solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts Department

(Composition 10 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 29 parts by mass ・ Esocyanate EO modified di- and triacrylate (second acrylate monomer, product name "M-315", Toagosei Co., Ltd. Product, bifunctional, weight average molecular weight 390): 32 parts by mass · methyl ethyl ketone (penetrating solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 11 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight: 4,000): 37.0 parts by mass-Pentaerythritol tetraacrylate (first Acrylate monomer, product name “M-450”, manufactured by Toagosei Co., Ltd., tetrafunctional, weight average molecular weight 400): 29.0 parts by mass tetraethylene glycol diacrylate (second acrylate monomer, product name “M- 240 ", manufactured by Toagosei Co., Ltd., bifunctional, weight average molecular weight 302): 32.0 parts by mass · methyl ethyl ketone (penetrating solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts Department

(Composition for antistatic hard coat layer 12)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
· Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass · Ditrimethylolpropane tetraacrylate (first Acrylate monomer, product name "M-408", tetrafunctional, weight average molecular weight 500): 29 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name "M-240", manufactured by Toagosei Co., Ltd. Bifunctional, weight average molecular weight 302): 32 parts by mass · methyl ethyl ketone (penetrable solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 13 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name: "Beamset 577", manufactured by Arakawa Chemical Industries, Ltd., weight average molecular weight: 1,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first acrylate monomer, Japan Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 29 parts by mass · Tetraethylene glycol diacrylate (second acrylate monomer, product name "M-240", manufactured by Toagosei Co., Ltd., bifunctional, weight average Molecular weight 302): 32 parts by mass · Methyl ethyl ketone (penetrating solvent): 100 parts by mass · Polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 14 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 52 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., 2 Functionality, weight average molecular weight 302): 9 parts by mass · Methyl ethyl ketone (penetrable solvent): 100 parts by mass · Polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 15 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 11 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., 2 Functionality, weight average molecular weight 302): 50 parts by mass · methyl ethyl ketone (penetrable solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 16 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
· Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 62 parts by mass · Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 4 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., 2 Functionality, weight average molecular weight 302): 32 parts by mass · methyl ethyl ketone (penetrating solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 17 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
· Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 62 parts by mass · Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 26 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., 2 Functionality, weight average molecular weight 302): 4 parts by mass · methyl ethyl ketone (penetrable solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition for antistatic hard coat layer 18)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 34 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., 2 Functional, weight average molecular weight 302): 16 parts by weight · trimethylolpropane trimethacrylate (methacrylate monomer, manufactured by Kyoeisha Chemical Co., Ltd., trifunctional, weight average molecular weight 300): 11 parts by weight · methyl ethyl ketone (permeable solvent): 100 parts by weight Polymerization initiator (IRGACURE 184, BASF Japan Company): 4 parts by mass

(Composition 19 for antistatic hard coat layer (two-liquid composition))
Antistatic agent-containing composition for hard coat layer • quaternary ammonium base-containing antistatic agent (antistatic agent, product name “1SX3000”, manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value) ): 2 parts by mass (solid content conversion value)
-Dipentaerythritol hexaacrylate (first acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 47.5 parts by mass-Tetraethylene glycol diacrylate (second acrylate monomer, product name " M-240 ", manufactured by Toagosei Co., Ltd., bifunctional, weight average molecular weight 302): 50.5 parts by mass. Methyl ethyl ketone (penetrating solvent): 40 parts by mass. Polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass
Antistatic agent-free composition for hard coat layer · Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 100 mass Part · Methyl ethyl ketone: 40 parts by mass (penetrable solvent)
Polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition for antistatic hard coat layer 20)
-Dimethylamino ethyl acrylate methyl chloride quaternary salt (product name "DMAEA-Q", manufactured by Kojin Co., Ltd., weight average molecular weight 194): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 29 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., 2 Functionality, weight average molecular weight 302): 32 parts by mass · methyl ethyl ketone (penetrating solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 21 for antistatic hard coat layer)
-Dimethylaminopropyl acrylamide methyl chloride quaternary salt (product name "DMAPAA-Q", manufactured by Kojin Co., Ltd., weight average molecular weight 207): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 29 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., 2 Functionality, weight average molecular weight 302): 32 parts by mass · methyl ethyl ketone (penetrating solvent): 100 parts by mass · polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 22 for antistatic hard coat layer)
· Quaternary ammonium base-containing antistatic agent (weight average molecular weight 80,000): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA, Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first acrylate) Monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 29 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name “M-240”, manufactured by Toagosei Co., Ltd., bifunctional Weight average molecular weight 302): 32 parts by mass · Methyl ethyl ketone (penetrable solvent): 100 parts by mass · Polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 23 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 29 parts by mass · Polyester-based acrylate oligomer (M-9050, manufactured by Toagosei Co., Ltd., trifunctional, weight average molecular weight 400): 32 parts by mass -Methyl ethyl ketone (permeable solvent): 100 parts by mass-Polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition for antistatic hard coat layer 24)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Dipentaerythritol hexaacrylate (first Acrylate monomer, manufactured by Nippon Kayaku Co., Ltd., 6-functional, weight average molecular weight 500): 29 parts by mass · Pentaerythritol triacrylate (photopolymerizable compound, product name "PET-30", manufactured by Nikka Fine Techno Co., Ltd., trifunctional Weight average molecular weight 300): 32 parts by mass · Methyl ethyl ketone (penetrable solvent): 100 parts by mass · Polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition for antistatic hard coat layer 25)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
Urethane acrylate (Product name “EBECRYL 5129”, manufactured by Daicel-Cytec, 6 functions, weight average molecular weight 800): 37 parts by mass Dipentaerythritol hexaacrylate (first acrylate monomer, manufactured by Nippon Kayaku Co., Ltd. 6 Functional, weight average molecular weight 500): 29 parts by weight · tetraethylene glycol diacrylate (second acrylate monomer, product name "M-240", manufactured by Toagosei Co., Ltd., bifunctional, weight average molecular weight 302): 32 parts by weight -Methyl ethyl ketone (permeable solvent): 100 parts by mass-Polymerization initiator (IRGACURE 184, manufactured by BASF Japan Ltd.): 4 parts by mass

(Composition 26 for antistatic hard coat layer)
-Quaternary ammonium base-containing antistatic agent (antistatic agent, product name "1SX3000", manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 10,000 to 20,000 (estimated value)): 2 parts by mass (solid content conversion value)
-Urethane acrylate (photopolymerizable urethane oligomer, product name "U-15HA", manufactured by Shin-Nakamura Chemical Co., Ltd., 15 functions, weight average molecular weight 4,000): 37 parts by mass-Pentaerythritol triacrylate (product name "PET" -30 ", manufactured by Nikka Fine Techno Co., Ltd., trifunctional, weight average molecular weight 300): 29 parts by mass Tetraethylene glycol diacrylate (second acrylate monomer, product name" M-240 ", manufactured by Toagosei Co., Ltd. Bifunctional, weight average molecular weight 302): 32 parts by mass ・ methyl ethyl ketone (penetrable solvent): 100 parts by mass ・ polymerization initiator (product name “IRGACURE 184”, manufactured by BASF Japan Ltd.): 4 parts by mass

<Preparation of composition for photocurable low refractive index layer>
Each component was mix | blended so that it might become a composition shown below, and the composition for photocurable low-refractive-index layers was obtained.
(Composition for photocurable low refractive index layer)
· Trimethylolpropane triacrylate (product name "Light Acrylate TMP-A", manufactured by Kyoeisha Chemical, trifunctional): 100 parts by mass · Hollow silica fine particle dispersion (fine particles, product name "Surria 4320", manufactured by JGC Co., Ltd. , Average particle diameter 60 nm, solid content 20 mass%): 100 mass parts (solid content value)
Methyl isobutyl ketone: 70 parts by mass Propylene glycol monomethyl ether acetate: 30 parts by mass Polymerization initiator (IRGACURE 127, manufactured by BASF Japan Ltd.): 0.07 parts

Example 1
Prepare a 60 μm thick triacetyl cellulose substrate (TD 60 UL, manufactured by Fuji Film Co., Ltd.) as a light transmitting substrate, and apply the composition 1 for antistatic hard coat layer on one side of the triacetyl cellulose film, A coating was formed. Next, after flowing dry air at 70 ° C. for 15 seconds at a flow rate of 0.2 m / s to the formed coating film, drying is further allowed to flow for 30 seconds at 70 ° C. at a flow rate of 10 m / s for drying The solvent in the coating was evaporated by Thereafter, ultraviolet light was irradiated in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) so that the integrated light amount was 30 mJ / cm ² to semi-cure the coating. After the coating is semi-cured, the composition for a photocurable low refractive index layer is applied onto the semi-cured coating, and the composition is photocured on the coating of the composition 1 for antistatic hard coat layer semi-cured. Film of the composition for the low refractive index layer was formed. Then, after flowing dry air at 70 ° C. for 15 seconds at a flow rate of 0.2 m / s to the formed coating film, dry air at 70 ° C. for 30 seconds at a flow rate of 10 m / s further for drying The solvent in the coating was evaporated by Finally, ultraviolet rays are irradiated under a nitrogen atmosphere (oxygen concentration 200 ppm or less) so that the integrated light quantity is 150 mJ / cm ² to completely cure the coating film, and an antistatic hard coat layer having a thickness of 8 μm and A low refractive index layer having a thickness of 0.1 μm was formed, and an optical film according to Example 1 was produced.

Examples 2 to 18 and Comparative Examples 3 to 9
In Examples 2 to 18 and Comparative Examples 3 to 9, an optical film was produced in the same manner as in Example 1 except that the composition shown in Table 1 was used as the composition for antistatic hard coat layer.

Example 19
A 60 μm thick triacetyl cellulose substrate (TD 60 UL, manufactured by Fuji Film Co., Ltd.) as a light transmitting substrate is prepared, and the antistatic agent in the composition 19 for antistatic hard coat layer is formed on one side of the triacetyl cellulose film. In order that the coating film of the composition for containing hard coat layer is closer to the triacetyl cellulose substrate side than the coating film of the composition for containing no antistatic agent in the composition 19 for antistatic hard coat layer, An antistatic agent-containing hard coat layer composition and an antistatic agent-free hard coat layer composition are simultaneously applied, and the coating of the antistatic agent-containing hard coat layer composition and the antistatic agent-free hard coat layer A coating of the composition was formed. Then, after flowing dry air at 70 ° C. for 15 seconds at a flow rate of 0.2 m / s to these formed coatings, dry air at 70 ° C. for 30 seconds at a flow rate of 10 m / s The solvent in these coatings was evaporated by drying. Then, ultraviolet rays were irradiated in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) so that the integrated light amount was 30 mJ / cm ² to semi-cure these coatings. After these coatings are semi-cured, the photocurable low refractive index layer composition is applied onto the coating of the semi-cured antistatic agent-free hard coat layer composition, and the semi-cured antistatic agent The coating film of the composition for photocurable low refractive index layers was formed on the coating film of the composition for non-containing hard-coat layers. Then, after flowing dry air at 70 ° C. for 15 seconds at a flow rate of 0.2 m / s to the formed coating film, dry air at 70 ° C. for 30 seconds at a flow rate of 10 m / s further for drying The solvent in the coating was evaporated by Finally, ultraviolet rays are irradiated in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) so that the integrated light quantity is 150 mJ / cm ² to completely cure the coating film, and the film thickness is 1.0 μm, containing no antistatic agent. An 8 μm antistatic hard coat layer comprising a hard coat layer and an antistatic agent-containing hard coat layer having a thickness of 7.0 μm and a low refractive index layer having a thickness of 0.1 μm are formed. An optical film was produced.

Comparative Example 1
In Comparative Example 1, an optical film was produced in the same manner as in Example 1 except that the film thickness of the antistatic hard coat layer was 3 μm.

Comparative Example 2
In Comparative Example 2, an optical film was produced in the same manner as in Example 1 except that the film thickness of the antistatic hard coat layer was 12 μm.

<Evaluation of optical film>
The following tests were performed and evaluated about the optical film produced in the said Example and comparative example, respectively. Here, among the tests shown below, the surface resistance measurement and the abrasion resistance test were respectively performed on the optical film before the saponification treatment and the optical film after the saponification treatment. The saponification treatment was performed by immersing the optical film in a 55 ° C. NaOH aqueous solution adjusted to 2N for 15 seconds to 5 minutes.

(Position evaluation of antistatic agent)
About each optical film produced by the said Example and comparative example, the position of the antistatic agent in an antistatic hard-coat layer was evaluated using several samples for every optical film. Specifically, a plurality of samples for evaluating the optical film according to Example 1 were produced as follows. First, a composition containing the same antistatic agent and methyl ethyl ketone as the antistatic agent (quaternary ammonium base-containing antistatic agent) used in Example 1 is applied to one surface of a plurality of triacetyl cellulose films and dried. Then, an antistatic layer with a film thickness of 0.5 μm was formed on each triacetyl cellulose film. Next, a composition containing no antistatic agent and containing dipentaerythritol hexaacrylate (DPHA), toluene, and a polymerization initiator (product name “IRGACURE 184”, manufactured by BASF Japan Ltd.) on each antistatic layer. The product was applied and irradiated with ultraviolet light to form a hard coat layer to prepare a plurality of samples. However, the hard coat layer of each sample was formed so that the film thickness was different every 0.1 μm for each sample. After preparing a plurality of samples, the surface resistance value of the optical film before saponification treatment according to Example 1 and the surface resistance value of the hard coat layer of each sample are measured, and the surface resistance value of the optical film according to Example 1 The sample which shows the surface resistance value almost the same as and was searched out. Here, in the optical film according to Example 1, since the surface resistance value is substantially the same as that of the sample found, it can be evaluated that the antistatic agent is present at substantially the same position as this sample. Therefore, in Example 1, at a position away from the surface of the antistatic hard coat layer in the depth direction of the antistatic hard coat layer, by a distance corresponding to the thickness of the hard coat layer of the found sample. It can be evaluated that an antistatic agent is present. Thus, the position of the antistatic agent calculated | required by the evaluation method was described in Table 1. In addition, the numerical value described in the column of "the position of the antistatic agent" in Table 1 means the depth from the surface of the antistatic hard coat layer, and at least the antistatic agent is present at that position. means. Similarly, in Examples 2 to 19 and Comparative Examples 1 to 9, the position of the antistatic agent in the antistatic hard coat layer was determined by the evaluation method as described above.

(Surface resistance measurement)
The surface resistance value of each of the optical films produced in the above Examples and Comparative Examples was measured using a surface resistance measurement device (Hiresta UP-HT450, manufactured by Mitsubishi Chemical Analytech Co., Ltd.).

(Abrasion resistance evaluation)
In each of the optical films produced in the above Examples and Comparative Examples, steel wool # 0000 (product name: Bonstar, manufactured by Nippon Steel Wool Co., Ltd.) is used, and a load of 300 g / cm ² is applied at a speed of 100 mm / sec. After reciprocal rubbing, a black tape was attached to the surface of the triacetylcellulose substrate opposite to the surface on which the low refractive index layer was formed, and the presence or absence of a scratch was visually evaluated under a three-wavelength fluorescent lamp. The evaluation criteria of the abrasion resistance test were as follows.
◎: no scratch was found.
○: Some scratches were observed but at a level that causes no practical problems.
Fair: more scratches were observed than ○.
X: Many scratches were confirmed.

(Interfering fringe observation evaluation)
The back surface reflection is prevented via a transparent adhesive on the surface of the triacetyl cellulose film of each of the optical films obtained in Examples and Comparative Examples on the opposite side to the surface on which the antistatic hard coat layer is formed. A black acryl plate for the purpose was attached, each optical film was irradiated with light from the side of the antistatic hard coat layer or the low refractive index layer, and was visually observed. As a light source, an interference fringe inspection lamp (sodium lamp) manufactured by Funatech Co., Ltd. was used. The occurrence of interference fringes was evaluated according to the following criteria.
◎: interference fringes were not confirmed.
○: The interference fringes were slightly confirmed, but at a level without any problem.
X: Interference fringes were clearly confirmed.

(Pencil hardness evaluation)
The pencil hardness defined in JIS K 5600-5-4 (1999) using a pencil having a pencil hardness of 2 H at a load of 4.9 N with respect to the surface of each optical film obtained in Examples and Comparative Examples The test was performed 3 times and it was evaluated whether it got damaged. When the optical film has a low refractive index layer, a pencil hardness test is performed on the surface of the low refractive index layer, and when the optical film does not have a low refractive index layer, the antistatic property is The pencil hardness test was performed on the surface of the hard coat layer.
○: No damage was found at all three times.
X: Scratched more than once.

(Anti-curl evaluation)
Each optical film obtained in Examples and Comparative Examples was cut into 10 cm × 10 cm to produce sample pieces. Then, place this sample piece on a horizontal table (plane) with the light transmitting substrate side facing down, measure how many mm the four corners of the sample piece are floating, and curl the average value (mm) evaluated. The evaluation criteria of curling evaluation were as follows.
:: 10 mm or less ○: 10 mm or more 15 mm or less △: 15 mm or more 20 mm or less ×: 20 mm or more

The evaluation results are shown in Table 1.

  In Comparative Example 1, although the surface resistance value is excellent, the antistatic agent is not present in the upper region which is a region having a depth of 0.2 μm or more and less than 2.0 μm from the surface of the antistatic hard coat layer. In addition, the surface resistance value after saponification treatment significantly increased as compared with that before saponification treatment, and the abrasion resistance after saponification treatment also decreased as compared with that before saponification treatment. This is because the film thickness of the antistatic hard coat layer is as thin as 3 μm, the antistatic agent is present at a position too close to the surface of the antistatic hard coat layer, and the antistatic agent is dropped off by the saponification treatment. It is believed that this is because the

In Comparative Example 2, the antistatic agent was not present in the upper region, and a surface resistance value of 1 × 10 ¹¹ Ω / □ or less was not obtained regardless of before or after the saponification treatment. This is because the film thickness of the antistatic hard coat layer is too thick, 12 μm, so the behavior of the antistatic hard coat layer with a film thickness of 8 μm differs from that of the antistatic agent generated in the film during drying or curing, It is considered that the antistatic agent is present at a position too far from the surface of the antistatic hard coat layer.

In Comparative Examples 3 and 4, the antistatic agent was not present in the upper region, and a surface resistance value of 1 × 10 ¹¹ Ω / □ or less was not obtained regardless of before or after the saponification treatment. This is considered to be because the antistatic agent was present at a position too far from the surface of the antistatic hard coat layer because the molecular weight of the antistatic agent was too small.

  In Comparative Example 5, the antistatic agent is not present in the upper region, and the surface resistance value before saponification treatment is very excellent, but the surface resistance value after saponification treatment is significantly increased compared to that before saponification treatment. And scratch resistance was not obtained before or after the saponification treatment. It is considered that this is because the antistatic agent was concentrated on the surface of the antistatic hard coat layer because the molecular weight of the antistatic agent was too large, and the antistatic agent was dropped off by the saponification treatment.

In Comparative Example 6, a monomer having the same molecular weight and functional group number as tetraethylene glycol diacrylate as the second acrylate monomer was added, but no antistatic agent was present in the upper region, and either before or after the saponification treatment The surface resistance value of not more than 1 × 10 ¹¹ Ω / □ was not obtained, and interference fringes were clearly observed. This is because the second acrylate monomer was not added, and because the second acrylate monomer was not added, the antistatic agent was present too far from the surface of the antistatic hard coat layer. It is thought that it is because it

In Comparative Example 7, the antistatic agent was not present in the upper region, and a surface resistance value of 1 × 10 ¹¹ Ω / □ or less was not obtained regardless of before and after the saponification treatment, and interference fringes were clearly observed. . This is because the second acrylate monomer was not added, and because the second acrylate monomer was not added, the antistatic agent was present too far from the surface of the antistatic hard coat layer. It is thought that it is because it

In Comparative Example 8, no antistatic agent is present in the upper region, and a surface resistance value of 1 × 10 ¹¹ Ω / □ or less can not be obtained before and after saponification treatment, and after saponification treatment as compared to before saponification treatment The scratch resistance was also reduced. This is considered to be because the molecular weight of the photopolymerizable urethane oligomer was too small, and the antistatic agent was present at a position too far from the surface of the antistatic hard coat layer.

In Comparative Example 9, the antistatic agent was not present in the upper region, and a surface resistance value of 1 × 10 ¹¹ Ω / □ or less was not obtained regardless of before or after the saponification treatment. This is because the first acrylate monomer has been added, and the first acrylate monomer has not been added, so that the antistatic agent is present too far from the surface of the antistatic hard coat layer. It is thought that it is because it Moreover, in Comparative Example 9, the abrasion resistance after the saponification treatment was lower than that before the saponification treatment. It is considered that this is because the crosslinked product of pentaerythritol triacrylate present on the surface of part of the antistatic hard coat layer was damaged by the saponification treatment. Furthermore, in Comparative Example 9, the pencil hardness was slightly inferior.

On the other hand, in each of Examples 1 to 19, the antistatic agent was present in the upper region. Moreover, before and after the saponification treatment, the surface resistance value and the scratch resistance of 1 × 10 ¹¹ Ω / □ or less were maintained. In Examples 7 and 8, although the surface resistance after saponification was slightly higher than the surface resistance before saponification, the surface resistance before and after the saponification was higher than this level. It can be considered as maintained.

Further, in the optical films after the saponification treatment according to Examples and Comparative Examples, when the load was changed from 300 g / cm ² to 500 g / cm ² and the same abrasion resistance test as described above was performed, the Example 18 was obtained. Only the optical film was not damaged.

  Furthermore, when an optical film was formed in the same manner as in Example 1 using the antistatic hard coat layer composition from which the urethane acrylate was removed from the antistatic hard coat layer composition 1, the optical film The pencil hardness was inferior to that of the optical film according to Example 1. In addition, the same method as in Example 1 using the composition for antistatic hard coat layer in which the urethane acrylate contained in the composition for antistatic hard coat layer 1 is replaced with the urethane acrylate having a weight average molecular weight of 100,000. As a result, an optical film was formed, and this optical film was inferior in pencil hardness to the optical film according to Example 1.

DESCRIPTION OF SYMBOLS 10, 50 ... Optical film 11, 51 ... Light transmissive base material 11A, 51A ... Mixed area | region 12, 52 ... Antistatic property hard-coat layer 13, 53 ... Low-refractive-index layer 14, 54A ... Antistatic agent 15 ... Binder resin 16, 17, 56 to 58: Coating film 20: Polarizing plate 21: Polarizer 30: Liquid crystal panel 40: Image display device 54: Antistatic agent-containing hard coat layer 54B: First binder resin 55: Antistatic agent not contained Hard coat layer 55A ... second binder resin R ... upper region

Claims (10)

An optical film comprising: a light transmitting substrate; and an antistatic hard coat layer provided on the light transmitting substrate,
The antistatic hard coat layer has a thickness of 4 μm to 10 μm,
The antistatic hard coat layer comprises an antistatic agent having a weight average molecular weight of 1,000 to 30,000 and a binder resin having a quaternary ammonium base,
The antistatic agent is not present on the surface of the antistatic hard coat layer, and the depth from the surface of the antistatic hard coat layer in the antistatic hard coat layer is 0.2 μm or more. Exists in the area less than 0 μm,
The surface resistance of the optical film is 1 × 10 ¹¹ Ω / □ Ri der below,
The antistatic hard coat layer comprises the antistatic agent, a photopolymerizable urethane oligomer having a weight average molecular weight of 1,000 or more and 70,000 or less, and an alkylene oxide group having four or more photopolymerizable functional groups. And a first acrylate monomer having a weight average molecular weight of 400 to 900 having four or more acryloyl groups, and a weight average molecular weight of 150 to less than 400 having an alkylene oxide group and two or more acryloyl groups. Composition for antistatic hardcoat layer comprising second acrylate monomer and penetrating solvent (with the exception of composition for antistatic hardcoat layer comprising both dipentaerythritol hexaacrylate and tetraethylene glycol diacrylate) Is a cured product of
The light transmitting substrate penetrates the light transmitting substrate from the light transmitting substrate and the composition for the antistatic hard coat layer in the vicinity of the interface with the antistatic hard coat layer. An optical film characterized by having a mixed region containing a cured product of a permeate containing the first acrylate monomer and the second acrylate monomer . The second acrylate monomer is selected from propylene oxide modified diacrylate, ethylene oxide (EO) isocyanurate modified di and triacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, and trimethylolpropane triacrylate. The optical film as described in 1. The said first acrylate monomer is selected from dipentaerythritol pentaacrylate, tripentaerythritol octaacrylate, tetrapentaerythritol decaacrylate, diglycerin tetraacrylate, ditrimethylolpropane tetraacrylate, and pentaerythritol tetraacrylate. The optical film as described in 1 or 2. The composition for an antistatic hard coat layer according to any one of claims 1 to 3, wherein the composition further comprises a methacrylate monomer having a weight average molecular weight of 300 or more and 1,000 or less having two or more methacryloyl groups. Optical film. The binder resin is composed of a first binder resin and a second binder resin,
The antistatic hard coat layer is provided on an antistatic agent-containing hard coat layer containing the antistatic agent and the first binder resin, and the antistatic agent-containing hard coat layer, and the antistatic agent-containing hard coat layer An antistatic agent-free hard coat layer which is in close contact with the coating layer, does not contain an antistatic agent, and contains the second binder resin, and the antistatic agent-containing hard coat layer and the antistatic agent in the region The optical film according to any one of claims 1 to 4 , wherein an interface with the agent-free hard coat layer is present. The antistatic agent-containing hard coat layer comprises the antistatic agent, a first acrylate monomer having no alkylene oxide group and a weight average molecular weight of 400 to 900, and an alkylene having a acryloyl group of 4 or more. A cured product of an antistatic agent-containing hard coat layer composition comprising at least a second acrylate monomer having a weight average molecular weight of 150 or more and less than 400 having an oxide group and 2 or more acryloyl groups,
The antistatic agent-free hard coat at least containing a photopolymerizable urethane oligomer having a weight average molecular weight of 1,000 to 70,000 having at least four photopolymerizable functional groups. A cured product of the layer composition,
The light transmitting base material penetrates the light transmitting base material from the light transmitting base material and the composition for the antistatic agent containing hard coat layer in the vicinity of the interface with the antistatic agent containing hard coat layer. The optical film according to claim 5 , further comprising: a mixed region including the cured product of the first acrylate monomer and the cured product of the permeate including the second acrylate monomer. The method further comprises a low refractive index layer provided on the antistatic hard coat layer, adjacent to the antistatic hard coat layer, and having a refractive index lower than that of the antistatic hard coat layer. The optical film according to any one of 1 to 6 . An optical film according to any one of claims 1 to 7 ;
A polarizing plate, comprising: a polarizer formed on the surface of the light transmitting substrate of the optical film opposite to the surface on which the antistatic hard coat layer is formed. A liquid crystal display panel comprising the optical film according to any one of claims 1 to 7 or the polarizing plate according to claim 8 . An image display device comprising the optical film according to any one of claims 1 to 7 or the polarizing plate according to claim 8 .

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