JP2005283872A - Polarizer plate with anti-reflection capability, its manufacturing method, and image display using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizer plate which uses a thin polarizing film but can avoid leakage of visible light in short and long wavelengths at crossed Nichol and has an even neutral surface color and is excellent in durability and not reflecting outer light, and to provide its manufacturing method and an image display of high durability and high quality using such a polarizer. <P>SOLUTION: This is a polarizer plate which has transparent protective films on both sides of its polarizing film, and one of these films is sequentially coated with at least one high refractive index layer and at least one low refractive index layer to make it a multilayered anti-reflection film. Further, this low refractive index layer of this polarizer plate contains at least one kind of inorganic hollow particles of a specific size having a specific refractive index. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polarizing plate, a method for producing the same, and an image display device using the same, and more specifically, a polarizing plate having excellent antireflection properties for display images, good image clarity and excellent visibility, and production thereof. The present invention relates to a method and an image display device.

  One of various displays is a liquid crystal display device, and its use is expanding year by year as a space-saving image display device with low power consumption. In the liquid crystal display device, the use of a polarizing plate is indispensable for the principle of image display, and the demand for the polarizing plate is expanding. In general, a polarizing plate has a protective film bonded to both surfaces or one surface of a polarizing film having polarizing ability via an adhesive layer. In an image display device such as a liquid crystal display device, an antireflection film that reduces the reflectivity by using the principle of optical interference in order to prevent a decrease in contrast and reflection of an image due to reflection of external light on a polarizing plate surface. It has become common to arrange (antireflection film) on the outermost surface of the display.

  Polyvinyl alcohol (hereinafter referred to as PVA) is mainly used as the material of the polarizing film. The PVA film is uniaxially stretched and then dyed with iodine or a dichroic dye, or dyed and then stretched, and further cured. A polarizing film is formed by crosslinking with a functional compound. Since the polarizing film is usually produced by stretching (longitudinal stretching) along the running direction (longitudinal direction) of the continuous film, the absorption axis of the polarizing film is substantially parallel to the longitudinal direction.

  The protective film is a transparent film that is optically transparent and has a small birefringence, and cellulose triacetate is mainly used. Conventionally, it is bonded to the polarizing film so that the slow axis of the protective film and the transmission axis of the polarizing film are perpendicular (that is, the slow axis of the protective film and the absorption axis of the polarizing film are parallel). .

  The antireflection treatment is performed by a design that can reduce reflection in the visible light region as much as possible by using an antireflection film manufactured as a multilayer laminate of a plurality of thin films made of materials having different refractive indexes. However, in the antireflection film having such a structure, since the film thickness of each layer constituting the multilayer laminate is constant in each layer, in principle, complete antireflection over the entire visible light region is not possible. Can not.

  For this reason, design is made so that reflection is generally emphasized in the vicinity of 550 nm, where the visibility is strong, and the reflection can be prevented in the widest possible wavelength range. For this reason for design, the antireflection effect outside the specific wavelength region is not sufficient at present, and the reflectance of a part of the short wavelength region and a part of the long wavelength region of visible light is different from that of the visible light region. It is larger than the reflectance in the wavelength region. As a result, there is a problem that the reflected light exhibits a specific hue and the display quality is deteriorated.

  On the other hand, as a laminated body in which a polarizing plate and an antireflection film are integrated, studies have been made to improve the display image quality. Specifically, a polarizing plate provided with an antireflection film has a reflectance of 3.5% or less in the range of 380 to 700 nm (Patent Document 1).

  In a reflective or transflective liquid crystal display device, a backlight generally used for a liquid crystal display device has emission line peaks at three wavelengths of 440 nm, 550 nm, and 610 nm. The same is an important point for improving color reproducibility, and a polarizing plate with an antireflection film that defines parallel transmittance and orthogonal transmittance at wavelengths of 440 nm, 550 nm and 610 nm has been proposed (Patent Document 2). And Patent Document 3).

Furthermore, since the antireflection film is used on the outermost surface of the display device, high scratch resistance is required. The low refractive index layer which is the outermost surface is a thin film having a thickness of around 100 nm, and in order to realize high scratch resistance, the strength of the film itself and the adhesion to the lower layer are desired. This method is still not enough.
JP 2003-270441 A JP 2002-22952 A JP 2003-344656 A

  Recently, LCDs have been widely used as flat panel displays essential in the age of advanced information / communication, taking advantage of their thinness, light weight, and low power consumption. Especially, the size of monitors and TVs that can display high-definition color images has increased. Or the growth of mobile is remarkable. For high-definition color image display, further neutralization of the color of the display image is required. In addition, larger display images are desired to have even greater uniformity across the screen. In particular, in liquid crystal monitors with a size of 15 inches or more, a light leakage failure (picture frame) from the periphery of the monitor that occurs because the polarizing film shrinks due to changes over time. It is desired to eliminate the failure.

  On the other hand, there has been a high demand for reducing the thickness of the polarizing film from the viewpoint of reducing the weight of the polarizing plate member or reducing the cost. However, it has become clear that as the polarizing film is made thinner, light leakage at the time of crossed Nicols on the short wave and long wave sides of visible light increases and the hue shifts from neutral gray.

  Accordingly, an object of the present invention is to provide a polarizing plate having a uniform in-plane color, good neutrality, and excellent durability and no reflection of external light.

  Another object of the present invention is to prevent the leakage of visible light on the short wave and long wave sides during crossed nicols even when the polarizing film is thin, and to provide good color and excellent durability of external light. The object is to provide a polarizing plate without reflection.

  Still another object of the present invention is to provide a high-performance and inexpensive polarizing plate having a polarizing film, which is obtained by an oblique stretching method, and has an obliquely stretched polymer film that can improve the yield in the polarizing plate punching process. There is to do.

  Still another object of the present invention is to provide an image display device having a display with good durability and comprising a polarizing plate in which an antireflection film is coated on one side of the polarizing film.

  According to the present invention, an antireflection film-coated polarizing plate having the following constitution, a method for producing the polarizing plate, and an image display device using the polarizing plate are provided, and the object of the present invention is achieved.

(1) A transparent protective film is provided on both sides of the polarizing film, and at least one high refractive index layer having a higher refractive index than the transparent protective film is provided on one side of the transparent protective film, and the refractive index of the transparent protective film In the polarizing plate formed with an antireflection film having a multilayer structure in which at least one low refractive index layer having a lower refractive index is sequentially coated, the low refractive index layer has a refractive index of 1.17 to 1.37. A polarizing plate comprising at least one kind of inorganic fine particles having a hollow structure and having an average particle diameter of 30% to 100% of the thickness of the low refractive index layer.

(2) The polarizing plate according to (1), wherein a transmittance at 700 nm in a crossed Nicol range is 0.001% to 0.3% and a transmittance at 410 nm is 0.001% to 0.3%. .

(3) of the CIE standard illuminant D _65, with respect to the incident angle of 5 ° incident light at 780nm region from the wavelength 380 nm, the CIE1976L ^* a ^* b ^* color space of the specular reflection light a ^*, b ^* values, 0 ≦ a ^* ≦ 7, −10 ≦ b ^* ≦ 0, and specularly reflected light with respect to incident light from any angle within an incident angle range of 5 to 45 ° is, in the color space, a ^* ≧ 0, The polarizing plate according to (1) or (2), wherein b ^* ≦ 0.

(4) of the CIE standard illuminant D _65, with respect to the incident angle of 5 ° incident light at 780nm region from the wavelength 380 nm, the light regularly reflected CIE1976L ^* a ^* b ^* color ^{space, L *, a *, b} * The polarizing plate according to any one of (1) to (3), wherein an in-plane change rate of each value is 20% or less.

(5) The high refractive index layer is composed of at least two high refractive index layers having different refractive indexes, and the antireflection film is composed of at least three layers, and the three layers satisfy the following formulas (2) to (4). The polarizing plate according to any one of (1) to (4), wherein the polarizing plate is sufficiently satisfied.
Formula (2): (m ₁ λ / 4) × 0.60 <n ₁ d ₁ <(m ₁ λ / 4) × 0.80
Formula (3): (m ₂ λ / 4) × 1.00 <n ₂ d ₂ <(m ₂ λ / 4) × 1.50
Formula (4): (m ₃ λ / 4) × 0.85 <n ₃ d ₃ <(m ₃ λ / 4) × 1.05
[Where m ₁ is 1, n ₁ is the refractive index of the lower refractive index layer (medium refractive index layer) of the two high refractive index layers, and d ₁ is the middle refractive index layer. M ₂ is 2, n ₂ is the refractive index of the higher refractive index layer (high refractive index layer) of the _two high refractive index layers, and d ₂ Is the layer thickness (nm) of the high refractive index layer; m ₃ is 1, n ₃ is the refractive index of the low refractive index layer, and d ₃ is the layer thickness (nm) of the low refractive index layer. is there. λ is the measurement wavelength. ]

(6) The high refractive index layer is a light scattering layer in which at least one kind of translucent particles having an average particle diameter of 0.5 to 5 μm is dispersed in a translucent resin, and the translucent particles and the translucent particles The polarizing plate according to any one of the above (1) to (4), wherein a difference in refractive index from the light-sensitive resin is 0.02 to 0.5.

(7) The above (1) to (6), wherein the transparent protective film is a cellulose acylate film having a moisture permeability in the range of 400 g / m ² · 24 hr to 2000 g / m ² · 24 hr at 60 ° C. and 95% RH. The polarizing plate in any one of.

(8) When the polarizing plate is left in an atmosphere of 60 ° C. and 90% RH for 500 hours, the light transmittance and the rate of change of the polarization degree before and after the polarizing plate are 3% or less based on absolute values. The polarizing plate according to any one of (1) to (7).

(9) When the polarizing plate is placed under heating at 70 ° C. for 120 hours, the dimensional change rate in the absorption axis direction and the dimensional change rate in the polarization axis direction before and after that are both ± 0.6%. The polarizing plate according to any one of (1) to (8), wherein

(10) The polarizing plate according to any one of (1) to (9), wherein an angle between the stretching axis of the transparent protective film and the stretching axis of the polarizing film is 10 ° or more and less than 90 °.

(11) The polarizing plate according to the above (1), wherein an optical compensation film having an optically anisotropic layer is provided on the transparent protective film on the other side.

(12) The polarizing film is produced by holding both ends of the polymer film for polarizing film continuously supplied by holding means, and stretching the holding means while applying the tension in the longitudinal direction of the film. In the method for producing a polarizing plate according to (1), the locus L1 of the holding means from the substantial holding start point to the substantial holding release point at one end of the polymer film for polarizing film, and the polymer film for polarizing film The trajectory L2 of the holding means from the substantial holding start point of the other end to the holding release point and the distance W between the substantial holding release points of both holding means satisfy the following formula (1) and the lengths of both holding means: A method for producing a polarizing plate, wherein the polarizing plate is produced by a stretching method in which a difference in conveying speed in a direction is less than 1%.
Formula (1): | L2-L1 |> 0.4W

(13) Upon stretching the polymer film for polarizing film, the polymer film for polarizing film is stretched while maintaining its volatile content at 5% by volume or more, and then the volatile content is decreased while shrinking. 12) The manufacturing method of the polarizing plate of description.

(14) The production of the polarizing plate according to the above (12) or (13), wherein an antireflection film is provided by continuously bonding a transparent protective film coated with an antireflection film on one side of the polarizing film. Method.

(15) An image display device, wherein the polarizing plate according to any one of (1) to (11) is disposed on an image display surface.

(16) The image display device according to (15), which is a transmissive, reflective, or transflective liquid crystal display device in any of TN, STN, IPS, VA, and OCB modes.

  According to the present invention, it is possible to provide a polarizing plate having a uniform in-plane color and good neutrality and excellent durability and no reflection of external light. In addition, according to the present invention, even when the polarizing film is thin, light leakage on the short-wave and long-wave sides of visible light at the time of crossed Nicol can be prevented, giving a good color and improving durability. It is possible to provide a polarizing plate that is excellent and has no external light reflection. Furthermore, according to the method of the present invention, the polarizing film has a polymer film that is obliquely stretched so that the yield in the polarizing plate punching step can be improved, and a high-performance and inexpensive polarizing plate can be provided. Furthermore, by disposing the polarizing plate of the present invention on the image display surface, it is possible to provide an image display device with good durability and high display quality.

  The polarizing plate of the present invention is formed by coating an antireflection film on one side of a transparent protective film of a polarizing film. Furthermore, it is preferable to provide an optical compensation film (or retardation film) on the transparent protective film opposite to the transparent protective film on which the antireflection film of the polarizing plate is coated.

<Antireflection film>
First, the antireflection film will be described.

[Layer structure of antireflection film]
The antireflection film according to the present invention is formed of a multilayer type antireflection film in which at least two layers having light transmittance and different refractive indexes (light transmission layers) are laminated. The antireflection film composed of two layers has a layer structure in the order of a transparent protective film, a high refractive index layer, and a low refractive index layer (outermost layer). The transparent protective film, the high refractive index layer and the low refractive index layer have a refractive index satisfying the following relationship.
Refractive index of high refractive index layer> Refractive index of transparent protective film> Refractive index of low refractive index layer

  A hard coat layer may be provided between the transparent protective film and the high refractive index layer. Furthermore, it may consist of a high refractive index hard coat layer or an antiglare high refractive index layer and a low refractive index layer.

The antireflection film composed of at least three layers is a transparent protective film, a layer having a lower refractive index (medium refractive index layer) of two high refractive index layers, and a layer having a higher refractive index among two high refractive index layers. Layers (high refractive index layer) and low refractive index layer (outermost layer) in this order. The transparent protective film, the middle refractive index layer, the high refractive index layer, and the low refractive index layer have a refractive index that satisfies the following relationship.
Refractive index of the high refractive index layer> Refractive index of the middle refractive index layer> Refractive index of the transparent protective film> Refractive index of the low refractive index layer

  A hard coat layer may be provided between the transparent protective film and the middle refractive index layer. Furthermore, it may consist of a medium refractive index hard coat layer, a high refractive index layer and a low refractive index layer.

  Each layer in such a multi-layer structure has a medium refractive index layer represented by the following mathematical formula (2), a high refractive index layer represented by the following mathematical formula (3), and a low refractive index layer represented by a lower wavelength. Satisfying the formula (4) is preferable in that an antireflection film having more excellent antireflection performance can be produced.

Formula (2): (m ₁ λ / 4) × 0.60 <n ₁ d ₁ <(m ₁ λ / 4) × 0.80
Formula (3): (m ₂ λ / 4) × 1.00 <n ₂ d ₂ <(m ₂ λ / 4) × 1.50
Formula (4): (m ₃ λ / 4) × 0.85 <n ₃ d ₃ <(m ₃ λ / 4) × 1.05
[Where m ₁ is 1, n ₁ is the refractive index of the lower refractive index layer (medium refractive index layer) of the two high refractive index layers, and d ₁ is the middle refractive index layer. M ₂ is 2, n ₂ is the refractive index of the higher refractive index layer (high refractive index layer) of the _two high refractive index layers, and d ₂ Is the layer thickness (nm) of the high refractive index layer; m ₃ is 1, n ₃ is the refractive index of the low refractive index layer, and d ₃ is the layer thickness (nm) of the low refractive index layer. is there]

  By adopting the above layer structure, the antireflection film can achieve both low reflection and a reduction in the color of reflected light, and a reduction in the color change due to the incident angle. When the polarizing plate integrated with the transparent protective film on which the protective film is laminated is applied to, for example, the outermost surface of the liquid crystal display device, a display device having unprecedented visibility can be obtained. The average value of the specular reflectance of incident light at an incident angle of 5 ° in the wavelength region from 450 nm to 650 nm is 0.5% or less, so that visibility is reduced due to reflection of external light on the display device surface. Further, when the content is 0.4% or less, reflection of external light can be sufficiently prevented.

The CIE standard illuminant D _65, with respect to the incident angle of 5 ° incident light at 780nm region from the wavelength 380 nm, the CIE1976L ^* a ^* b ^* color space of the specular reflection light a ^*, b ^* values, 0 ≦ a ^* ≦ 7, −10 ≦ b ^* ≦ 0, and specularly reflected light with respect to incident light from all angles within an incident angle range of 5 to 45 ° is a ^* ≧ 0, b ^* ≦ By satisfying 0, the color of the reflected light at a low incident angle can be reduced, and the change in the color associated with the incident angle of the reflected light can be reduced.

Further, specularly reflected light with respect to incident light from all angles within an incident angle range of 5 to 45 ° is within the range of C ^* = [(a ^* ) ² + (b ^* ) ² ] ^1/2 ≦ 12 in the color space. By reducing the coloration of the reflected light from red purple to blue purple, which has been a problem with conventional polarizing plates with an antireflection film, the color change due to the incident angle of the reflected light is further reduced. be able to.

Furthermore, by making it within the range of C ^* = [(a ^* ) ² + (b ^* ) ² ] ^1/2 ≦ 10, it is possible to sufficiently reduce the change in the color of the reflected light and its incident angle. . When this polarizing plate with an antireflection film is applied to a liquid crystal display device, the color tone when a bright external light is slightly reflected, such as an indoor fluorescent lamp, is neutral and does not matter over a wide incident angle. .

Specifically, it is preferable that a ^* ≧ 0 does not give cyan, and b ^* ≦ 0 does not give yellow. If a ^* ≧ 0, b ^* ≦ 0, and C ^* = [(a ^* ) ² + (b ^* ) ² ] ^1/2 <12, the magenta taste is not too strong, which is preferable. .

The specular reflectance and color are measured by attaching an adapter “ARV-474” to a spectrophotometer “V-550” (manufactured by JASCO Corporation), and in the wavelength region of 380 to 780 nm, the incident angle θ ( Antireflection properties can be evaluated by measuring the specular reflectivity at an output angle −θ at θ = 5 to 45 ° and 5 ° intervals, and calculating an average reflectivity of 450 to 650 nm. Furthermore, from the measured reflectance spectra, L ^* value of the CIE1976L ^* a ^* b ^* color space representing the color of specular reflection light with respect to incident light of each angle of incidence of the CIE standard illuminant D _65, a ^* value, b ^* value And the color of the reflected light can be evaluated.

  Further, since the color of the reflected light is greatly reduced as described above, the color unevenness of the reflected light due to the film thickness unevenness of the antireflection film is also greatly reduced. That is. The allowable range of film thickness unevenness is widened, the manufacturing yield is increased, and the cost can be further reduced.

Quantitatively, the CIE standard light source in the wavelength region of 380 nm to 780 nm in any two places 10 cm away in the TD direction (direction perpendicular to the longitudinal direction of the transparent protective film) or MD direction (longitudinal direction of the transparent protective film) It can be expressed by the color unevenness of specularly reflected light with respect to incident light with an incident angle of 5 ° of D ₆₅ , and the ΔEa ^* b ^* value of the CIE 1976 L ^* a ^* b ^* color space is preferably less than 2, 1.5 If it is less than this, it is more preferable because unevenness cannot be completely detected by human eyes.

In the present invention, “a ^* b ^* value or C ^* value at all incident angles of 5 to 45 ° is within the above range” means regular reflection with respect to incident light at intervals of 5 ° of 5 to 45 °. This means that the a ^* , b ^* value or C ^* calculated from the optical spectrum is within the above range.

  Hereinafter, the high refractive index layer and then the low refractive index layer will be described in detail.

(High refractive index layer)
The high refractive index layer is a cured product having a refractive index of 1.55 to 2.50, which is formed by coating a curable composition containing inorganic compound fine particles (hereinafter sometimes referred to as inorganic fine particles) having a high refractive index and a matrix binder. It is preferable to consist of a film. The refractive index is preferably 1.65 to 2.40, more preferably 1.70 to 2.20.

  Further, the surface of the high refractive index layer forms a fine surface irregularity with a size that does not optically affect, and the arithmetic average roughness of the surface irregularity of the high refractive index layer based on JIS B-0601-1994 ( Ra) is 0.001 to 0.03 [mu] m, further 0.001 to 0.015 [mu] m, especially 0.001 to 0.010 [mu] m; ten-point average roughness (Rz) is 0.001 to 0.06 [mu] m, Further, it is in the range of 0.002 to 0.05 μm, particularly 0.002 to 0.025 μm, and the maximum height (Ry) is 0.09 μm or less, further 0.05 μm or less, particularly 0.04 μm or less. It is preferable that Further, in the above-described fine surface irregularity having a size that does not affect optically, the ratio (Ra / Rz) of arithmetic average roughness (Ra) to ten-point average roughness (Rz) is 0.15 or more. And it is preferable that the average space | interval (Sm) of the surface unevenness | corrugation of this high refractive index layer based on JISB-0601-1994 is 0.01-1 micrometer. Here, the relationship between Ra and Rz indicates the uniformity of surface irregularities. More preferably, the (Ra / Rz) ratio is 0.17 or more, and the average interval (Sm) is 0.01 to 0.8 μm. Within these ranges, the coated surface of the layer coated on the high refractive index layer is excellent in that there is no unevenness or streaks, and the adhesion between both layers can be improved. It becomes. The concave and convex shapes on the surface of the layer can be evaluated by an atomic force microscope (AFM).

  In order to make a high refractive index layer a high refractive index cured film having a refractive index of 1.55 to 2.50 in which inorganic fine particles having a high refractive index are dispersed in a matrix binder, the refractive index of the matrix binder is usually 1 From 4 to 1.5, the proportion of the fine particles used is determined by the refractive index of the fine particles used, but is preferably 40 to 80% by mass of the total mass of the cured film, more preferably It is 45-75 mass%.

  Thus, in order to increase the film strength of the high refractive index layer designed by increasing the ratio of the inorganic fine particles and to strengthen the adhesion with the upper layer after providing the upper layer, as described later. In addition, the inorganic fine particles having the same ultrafine particle size and the same particle size should be used, and this should be uniformly dispersed in the high refractive index layer, and the surface of the layer should form the uneven state as described above. Is preferred. By setting the shape and distribution of the surface irregularities on the entire surface of the high refractive index layer to a specific range, even when an upper layer is provided continuously on a long film, the entire surface of the layer is uniformly and sufficiently anchored. It is preferable because the adhesion is maintained. Further, the adhesiveness is maintained without change even after a long period of storage, which is preferable.

  The adhesion between the cured film of the high refractive index layer in the present invention and the upper layer (low refractive index layer) coated on the high refractive index layer is 50 mg in the amount of abrasion in the Taber abrasion test based on JIS K-6902. In the following, it is further preferable to be 40 mg or less. The Taber abrasion test is specifically the amount of abrasion after 500 revolutions at a load of 1 kg. Within this range, scratch resistance as an antireflection film is sufficiently maintained, which is preferable.

  Further, in the antireflection film including the high refractive index layer formed with the surface shape, the number of luminance defects having a diameter of 50 μm or more that is easily noticeable as a foreign object is 20 or less per square meter. It is preferable to become.

[Composition for forming a high refractive index layer]
(Inorganic fine particles with high refractive index)
The high refractive index inorganic fine particles contained in the high refractive index layer in the present invention have a refractive index of 1.80 to 2.80, more preferably 1.90 to 2.80; an average primary particle size of 3 to 150 nm, Furthermore, it is preferable that it is 3-100 nm, especially 5-80 nm. If the refractive index of the inorganic fine particles is 1.80 or more, the refractive index of the layer can be effectively increased, and if the refractive index is 2.80 or less, there is no inconvenience such as coloring of the particles, which is preferable. Further, if the average particle size of the primary particles of the inorganic fine particles is 150 nm or less, the haze value of the high refractive index layer to be formed is high, and there is no inconvenience such as impairing the transparency of the layer. It is preferable because a high refractive index is maintained.

  Specific examples of preferable high refractive index inorganic fine particles include oxides or composite oxides such as Ti, Zr, Ta, In, Nd, Sn, Sb, Zn, La, W, Ce, Nb, V, Sm, and Y, and sulfide. The particle | grains which have an object as a main component are mentioned. Here, the main component refers to a component having the largest content (% by mass) among the components constituting the particles. More preferable inorganic fine particles in the present invention are particles mainly composed of an oxide or composite oxide containing at least one metal element selected from Ti, Zr, Ta, In, and Sn.

  The inorganic fine particles may contain various elements in the particles (hereinafter, such elements may be referred to as containing elements). Examples of the contained element include Li, Si, Al, B, Ba, Co, Fe, Hg, Ag, Pt, Au, Cr, Bi, P, and S. In the case of tin oxide and indium oxide, it is preferable to contain an element such as Sb, Nb, P, B, In, V, or halogen in order to increase the conductivity of the particles, and in particular, about 5 to 20 mass of antimony oxide. % Is most preferable.

  Particularly preferred inorganic fine particles in the present invention are inorganic fine particles mainly composed of titanium dioxide containing at least one element selected from Co, Zr, and Al as contained elements (hereinafter sometimes referred to as “specific oxide”). ). A particularly preferable element is Co. The total content of Co, Al and Zr is preferably 0.05 to 30% by mass with respect to Ti, more preferably 0.1 to 10% by mass, still more preferably 0.2 to 7% by mass, particularly Preferably it is 0.3-5 mass%, Most preferably, it is 0.5-3 mass%. The contained elements Co, Al, and Zr are present inside or on the surface of the inorganic fine particles mainly composed of titanium dioxide. It is more preferable that it exists inside the inorganic fine particles mainly composed of titanium dioxide, and most preferable that it exists both inside and on the surface. Among these contained elements, the metal element may exist as an oxide.

  As another preferable inorganic fine particle, a composite oxide of titanium element and at least one metal element (hereinafter also abbreviated as “Met”) selected from metal elements having an oxide having a refractive index of 1.95 or more. In addition, the composite oxide includes inorganic fine particles doped with at least one metal ion selected from Co ions, Zr ions, and Al ions (sometimes referred to as “specific multi-oxide”). It is done. Here, Ta, Zr, In, Nd, Sb, Sn, and Bi are preferable as the metal element whose refractive index of the oxide is 1.95 or more. In particular, Ta, Zr, Sn, and Bi are preferable. The content of the metal ions doped in the composite oxide is preferably within a range not exceeding 25 mass% with respect to the total amount of metal [Ti + Met] constituting the composite oxide from the viewpoint of maintaining the refractive index. More preferably, it is 0.05-10 mass%, More preferably, it is 0.1-5 mass%, Most preferably, it is 0.3-3 mass%.

  The doped metal ion may exist as a metal ion or in any form of metal atom, and may appropriately exist from the surface to the inside of the composite oxide. It is preferably present both on the surface and inside.

  The inorganic fine particles preferably have a crystal structure. The crystal structure is preferably composed mainly of rutile, a mixed crystal of rutile / anatase, and anatase, and particularly preferably a rutile structure. Accordingly, the inorganic fine particles of the specific oxide or the specific double oxide have a refractive index of 1.90 to 2.80, which is preferable. The refractive index is more preferably 2.10 to 2.80, and still more preferably 2.20 to 2.80. In addition, this can suppress the photocatalytic activity of titanium dioxide, and can significantly improve the weather resistance of the high refractive index layer itself and the upper / lower layers in contact with the high refractive index layer in the present invention. ,preferable.

  A conventionally known method can be used as a method for doping the specific metal element or metal ion. For example, methods described in JP-A-5-330825, 11-263620, JP-A-11-512336, European Patent No. 0335773, etc .; ion implantation method [for example, Shunichi Gonda, Jun Ishikawa 3. Eiji Kamijo, “Ion Beam Application Technology” CMC Co., Ltd., published in 1989, Yasushi Aoki, “Surface Science” 18 (5), 262, 1998, Shoichi Anbo, “Surface Science” 20 (2), p. 60, 1999, etc.].

The inorganic fine particles may be surface treated. The surface treatment is a modification of the particle surface using an inorganic compound and / or an organic compound, whereby the wettability of the surface of the inorganic fine particles is adjusted to form fine particles in an organic solvent, and a high refractive index layer. Dispersibility and dispersion stability in the forming composition are improved. Examples of inorganic compounds that are physicochemically adsorbed on the particle surface include inorganic compounds containing silicon (such as SiO ₂ ), inorganic compounds containing aluminum [such as Al ₂ O ₃ and Al (OH) ₃ ], and cobalt. Inorganic compounds containing (CoO ₂ , Co ₂ O ₃ , Co ₃ O ₄ etc.), inorganic compounds containing zirconium [ZrO ₂ , Zr (OH) ₄ etc.], inorganic compounds containing iron (Fe ₂ O ₃ etc.) ) And the like.

  As examples of organic compounds used for the surface treatment, conventionally known surface modifiers of inorganic fillers such as metal oxides and inorganic pigments can be used. For example, it is described in “Pigment Dispersion Stabilization and Surface Treatment Technology / Evaluation”, Chapter 1 (Technical Information Association, published in 2001).

  Specifically, an organic compound having a polar group having an affinity for the surface of the inorganic fine particles and a coupling compound can be mentioned. Examples of the polar group having affinity with the surface of the inorganic fine particles include a carboxy group, a phosphono group, a hydroxy group, a mercapto group, a cyclic acid anhydride group, an amino group, and the like, and a compound containing at least one kind in the molecule is preferable. . For example, long-chain aliphatic carboxylic acids (eg, stearic acid, lauric acid, oleic acid, linoleic acid, linolenic acid, etc.), polyol compounds (eg, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, ECH (epichlorohydrin) modified glycerol triacrylate Etc.), phosphono group-containing compounds (for example, EO (ethylene oxide) -modified phosphoric triacrylate, etc.), alkanolamines (ethylenediamine EO adducts (5 mol), etc.).

As a coupling compound, a conventionally well-known organometallic compound is mentioned, A silane coupling agent, a titanate coupling agent, an aluminate coupling agent etc. are contained. Silane coupling agents are most preferred. Specific examples include compounds described in paragraph numbers “0011” to “0015” in JP-A-2002-9908 and 2001-310423.
Two or more kinds of compounds used for these surface treatments can be used in combination.

  The inorganic fine particles are also preferably fine particles having a core / shell structure in which a shell made of another inorganic compound is formed using the inorganic fine particles as a core. The shell is preferably an oxide composed of at least one element selected from Al, Si, and Zr. Specifically, for example, the contents described in JP-A-2001-166104 can be mentioned.

  The shape of the inorganic fine particles is not particularly limited, but is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape, or an indefinite shape. The inorganic fine particles may be used singly or in combination of two or more.

(Dispersant)
In order to use the inorganic fine particles as stable predetermined ultrafine particles, it is preferable to use a dispersant in combination. The dispersant is preferably a low molecular compound or a high molecular compound having a polar group having an affinity for the surface of the inorganic fine particles.

Examples of the polar group include a hydroxy group, a mercapto group, a carboxyl group, a sulfo group, a phosphono group, an oxyphosphono group, a —P (═O) (R ₁ ) (OH) group, and —O—P (═O) (R ₁ ) (OH) group, amide group (—CONHR ₂ , —SO ₂ NHR ₂ ), cyclic acid anhydride-containing group, amino group, quaternary ammonium group and the like.

Here, R ₁ represents a hydrocarbon group having 1 to 18 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, dodecyl group, octadecyl group, chloroethyl group, methoxy group) Ethyl group, cyanoethyl group, benzyl group, methylbenzyl group, phenethyl group, cyclohexyl group, etc.). R ₂ represents a hydrogen atom or the same content as R ₁ .

In the polar group, the group having a dissociable proton may be a salt thereof. The amino group and quaternary ammonium group may be any of primary amino group, secondary amino group or tertiary amino group, and more preferably tertiary amino group or quaternary ammonium group. The group bonded to the nitrogen atom of the secondary amino group, tertiary amino group or quaternary ammonium group is an aliphatic group having 1 to 12 carbon atoms (having the same contents as the above R ₁ or R ₂ group, etc. ) Is preferable. The tertiary amino group may be a ring-forming amino group containing a nitrogen atom (for example, a piperidine ring, a morpholine ring, a piperazine ring, a pyridine ring, etc.), and the quaternary ammonium group is a cyclic amino group. Or a quaternary ammonium group. In particular, an alkyl group having 1 to 6 carbon atoms is more preferable.

The counter ions of the quaternary ammonium group are halide ions, PF ₆ ions, SbF ₆ ions, BF ₄ ions, B (R ₃ ) 4 ions (R ₃ represents a hydrocarbon group, for example, butyl group, phenyl group, tolyl Group, naphthyl group, butylphenyl group, etc.), sulfonate ions and the like are preferable.

  The polar group of the dispersant is preferably an anionic group having a pKa of 7 or less or a salt of these dissociating groups. In particular, carboxyl groups, sulfo groups, phosphono groups, oxyphosphono groups, or salts of these dissociating groups are preferred.

The dispersant preferably further contains a crosslinkable or polymerizable functional group. As the crosslinkable or polymerizable functional group, an ethylenically unsaturated group capable of addition reaction / polymerization reaction by radical species [for example, (meth) acryloyl group, allyl group, styryl group, vinyloxy group carbonyl group, vinyloxy group, etc.], And cationically polymerizable groups (epoxy groups, thioepoxy groups, oxetanyl groups, vinyloxy groups, spiroorthoester groups, etc.), polycondensation reactive groups (hydrolyzable silyl groups, etc., N-methylol groups) and the like, preferably ethylene. An unsaturated group, an epoxy group, or a hydrolyzable silyl group.
Specific examples include the compounds described in paragraph numbers [0013] to [0015] in JP-A No. 2001-310423.

The dispersant used in the present invention is preferably a polymer dispersant. In particular, a polymer dispersant containing an anionic group and a crosslinkable or polymerizable functional group is preferable. The mass average molecular weight (Mw) of the polymer dispersant is not particularly limited, but is preferably 1 × 10 ³ or more as a polystyrene equivalent value measured by GPC method. More preferable Mw is 2 × 10 ³ to 1 × 10 ⁶ , further preferably 5 × 10 ³ to 1 × 10 ⁵ , and particularly preferably 8 × 10 ³ to 8 × 10 ⁴ . Those in this range are preferred because inorganic fine particles are easily dispersed and stable dispersions free from aggregates and precipitates can be obtained. Specific examples include the contents described in paragraph numbers [0024] to [0041] in JP-A-11-153703.

(Dispersion medium)
The dispersion medium used for wet dispersion of the inorganic fine particles can be appropriately selected from water and organic solvents, and is preferably a liquid having a boiling point of 50 ° C. or higher, and an organic solvent having a boiling point in the range of 60 ° C. to 180 ° C. More preferably, it is a solvent.

  The dispersion medium is preferably used in such a ratio that the total components for forming a high refractive index layer containing inorganic fine particles and a dispersant are 5 to 50% by mass. Furthermore, 10-30 mass% is preferable. In this range, the dispersion easily proceeds, and the resulting dispersion is preferable because it has a viscosity range with good workability.

  Examples of the dispersion medium include alcohols, ketones, esters, amides, ethers, ether esters, hydrocarbons, halogenated hydrocarbons, and the like. Specifically, alcohol (for example, methanol, ethanol, propanol, butanol, benzyl alcohol, ethylene glycol, propylene glycol, ethylene glycol monoacetate, etc.), ketone (for example, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methylcyclohexanone, etc.), ester ( For example, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl formate, propyl formate, butyl formate, ethyl lactate, etc.), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methyl chloroform), aromatic Group hydrocarbons (eg, benzene, toluene, xylene, etc.), amides (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone, etc.), ethers (eg, dioxane) Emissions, tetrahydrofuran, ethylene glycol dimethyl ether, propylene glycol dimethyl ether, etc.), ether alcohols (such as 1-methoxy-2-propanol, ethyl cellosolve, methyl carbinol and the like). Two or more of them may be mixed and used. Preferred dispersion media include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol. In addition, a coating solvent system mainly comprising a ketone solvent (for example, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.) is also preferably used, and the content of the ketone solvent is 10% of the total solvent contained in the composition for forming a high refractive index layer. % Or more is preferable. More preferably, it is 30 mass% or more, More preferably, it is 60 mass% or more.

(Inorganic fine particles)
When the curable composition for forming a high refractive index layer used in the present invention is an ultrafine particle dispersion of an inorganic compound having an average particle size of 100 nm or less, the stability of the liquid of the composition is improved. The high refractive index layer, which is a cured film formed from a conductive composition, is a transparent high refractive index layer in which inorganic fine particles are uniformly dispersed in an ultrafine particle state in the matrix of the cured film, and the optical properties are uniform and transparent Is formed. The size of the ultrafine particles present in the matrix of the cured film is preferably in the range of an average particle size of 3 to 100 nm, more preferably 5 to 100 nm. In particular, 10 to 80 nm is most preferable. Furthermore, it is preferable that large particles having an average particle diameter of 500 nm or more are not included, and it is particularly preferable that large particles having an average particle diameter of 300 nm or more are not included. Thereby, the cured film surface can form the above-mentioned specific uneven | corrugated shape, and is preferable.

  In order to disperse the high refractive index inorganic fine particles in the size of ultrafine particles not containing coarse particles in the above range, a wet dispersion method using a medium having an average particle diameter of less than 0.8 mm together with the dispersant is used. Can be achieved in a distributed manner.

  Examples of the wet disperser include conventionally known ones such as a sand grinder mill (eg, a bead mill with pins), a dyno mill, a high-speed impeller mill, a pebble mill, a roller mill, an attritor, and a colloid mill. In particular, a sand grinder mill, a dyno mill, and a high-speed impeller mill are preferable for dispersing the inorganic fine particles used in the present invention in ultrafine particles.

  As the media used together with the disperser, the average particle size is preferably less than 0.8 mm, and when the media has an average particle size within this range, the inorganic fine particle diameter is 100 nm or less, and the particle diameter is Uniform ultrafine particles can be obtained. The average particle size of the media is more preferably 0.5 mm or less, and even more preferably 0.05 to 0.3 mm. Moreover, as a medium used for wet dispersion, beads are preferable. Specific examples include zirconia beads, glass beads, ceramic beads, steel beads, etc., and 0.05 to 0.2 mm from the viewpoint of durability and ultrafine particle formation such that the beads are not easily broken during dispersion. Zirconia beads are particularly preferred.

  The dispersion temperature in the dispersion step is preferably 20 to 60 ° C, more preferably 25 to 45 ° C. This is preferable because dispersion in the ultrafine particles at a temperature in this range does not cause re-aggregation or precipitation of the dispersed particles. This is presumably because adsorption of the dispersant to the inorganic compound particles is appropriately performed and dispersion stability is not deteriorated due to desorption of the dispersant from the particles at room temperature. By carrying out the dispersion step in such a range, it is possible to form a high refractive index film excellent in refractive index uniformity, film strength, adhesion to an adjacent layer, etc. without impairing transparency.

  Moreover, you may implement a preliminary dispersion process before the said wet dispersion | distribution process. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder.

  Furthermore, in order that the dispersed particles in the dispersion satisfy the above-mentioned range of the average particle diameter and the monodispersibility of the particle diameter, separation treatment with beads is performed in order to remove coarse aggregates in the dispersion. It is also preferable to arrange the filter medium so that it is microfiltered in The filter medium for fine filtration preferably has a filtration particle size of 25 μm or less. The type of filter medium for microfiltration is not particularly limited as long as it has the above performance, and examples thereof include a filament type, a felt type, and a mesh type. The material of the filter medium for microfiltration of the dispersion is not particularly limited as long as it has the above-described performance and does not adversely affect the resulting composition for forming a high refractive index layer. For example, stainless steel, polyethylene, polypropylene , Nylon and the like.

(Matrix of high refractive index layer)
The high refractive index layer preferably contains high refractive index inorganic fine particles and a matrix.

According to a preferred embodiment of the present invention, the matrix of the high refractive index layer is:
(A) an organic binder, or (B) an organometallic compound containing a hydrolyzable functional group and a partial condensate of this organometallic compound,
After the application of the composition for forming a high refractive index layer containing at least one of the above, it is formed by curing.

(A) Organic binder As an organic binder,
(A) a conventionally known thermoplastic resin;
(B) a combination of a conventionally known reactive curable resin and a curing agent, or (c) a combination of a binder precursor (such as a curable polyfunctional monomer or polyfunctional oligomer described below) and a polymerization initiator,
The binder formed from is mentioned.

  It is preferable that a composition for forming a high refractive index layer is prepared from a dispersion containing the organic binder (a), (b) or (c) above, a high refractive index inorganic fine particle and a dispersant. This composition is applied onto a transparent protective film to form a coating film, and then cured by a method according to the component for forming a binder to form a high refractive index layer. The curing method is appropriately selected depending on the type of the binder component. For example, a crosslinking reaction or a polymerization reaction of a curable compound (for example, a polyfunctional monomer or a polyfunctional oligomer) is performed by at least one of heating and light irradiation. The method to make it occur is mentioned. Especially, the method of forming the binder which hardened | cured the crosslinking reaction or the polymerization reaction of the curable compound by irradiating light using the combination of said (c) is preferable.

  Furthermore, it is preferable to carry out a crosslinking reaction or a polymerization reaction with the dispersant contained in the dispersion liquid of high refractive index inorganic fine particles simultaneously with or after the application of the composition for forming a high refractive index layer.

  The binder in the cured film thus prepared is, for example, a crosslinking or polymerization reaction between the above-described dispersant and a curable polyfunctional monomer or polyfunctional oligomer that is a precursor of the binder, and the binder contains a dispersant. An anionic group is incorporated. Furthermore, the binder in the cured film has a function in which the anionic group maintains the dispersion state of the inorganic fine particles, so that the crosslinked or polymerized structure imparts a film forming ability to the binder and contains the high refractive index inorganic fine particles. The physical strength, chemical resistance, and weather resistance in the film can be improved.

  Examples of the thermoplastic resin (a) include polystyrene resin, polyester resin, cellulose resin, polyether resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl copolymer resin, polyacrylic resin, and polymethacrylic resin. Examples thereof include resins, polyolefin resins, urethane resins, silicone resins, imide resins, and the like.

  Moreover, it is preferable to use a thermosetting resin and / or an ionizing radiation curable resin as the reaction curable resin (b). Thermosetting resins include phenolic resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation resin, silicon resin, polysiloxane Examples thereof include resins. Examples of ionizing radiation curable resins include radical polymerizable unsaturated groups [(meth) acryloyloxy group, vinyloxy group, styryl group, vinyl group, etc.] and / or cationic polymerizable groups (epoxy group, thioepoxy group, vinyloxy group). , Oxetanyl group, etc.), for example, relatively low molecular weight polyester resin, polyether resin, (meth) acrylic resin, epoxy resin, urethane resin, alkyd resin, spiroacetal resin, polybutadiene resin, polythiol Examples include polyene resins.

  As needed for these reaction curable resins, crosslinking agents (epoxy compounds, polyisocyanate compounds, polyol compounds, polyamine compounds, melamine compounds, etc.), polymerization initiators (azobis compounds, organic peroxide compounds, organic halogen compounds, oniums) Conventionally known compounds such as curing agents such as UV photoinitiators such as salt compounds and ketone compounds) and polymerization accelerators (organic metal compounds, acid compounds, basic compounds, etc.) are used. Specific examples include compounds described by Fuzo Yamashita and Tosuke Kaneko “Crosslinking Agent Handbook” (published by Taiseisha, 1981).

  Hereinafter, a method for forming a cured binder by crosslinking or polymerizing a curable compound by light irradiation using the combination of (c), which is a preferable method for forming a cured binder, will be mainly described.

  The functional group of the photocurable polyfunctional monomer or polyfunctional oligomer may be either radically polymerizable or cationically polymerizable.

  Examples of the radical polymerizable functional group include an ethylenically unsaturated group such as a (meth) acryloyl group, a vinyloxy group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group is preferable. It is preferable to contain a polyfunctional monomer containing two or more radically polymerizable groups in the molecule.

  The radical polymerizable polyfunctional monomer is preferably selected from compounds having at least two terminal ethylenically unsaturated bonds. Preferably, it is a compound having 2 to 6 terminal ethylenically unsaturated bonds in the molecule. Such a compound group is widely known in the polymer material field, and these can be used without particular limitation in the present invention. These can have chemical forms such as, for example, monomers, prepolymers (ie, dimers, trimers and oligomers) or mixtures thereof, and copolymers thereof.

  Examples of radically polymerizable monomers include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof, preferably Examples include esters of unsaturated carboxylic acids and aliphatic polyhydric alcohol compounds, and amides of unsaturated carboxylic acids and aliphatic polyvalent amine compounds.

  Also, addition reaction products of unsaturated carboxylic acid esters and amides having a nucleophilic substituent such as hydroxyl group, amino group and mercapto group with monofunctional or polyfunctional isocyanates and epoxies, polyfunctional carboxylic acids. A dehydration condensation reaction product with an acid or the like is also preferably used. A reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol is also suitable. As yet another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene or the like instead of the unsaturated carboxylic acid.

  Examples of the aliphatic polyhydric alcohol compound include alkanediol, alkanetriol, cyclohexanediol, cyclohexanetriol, inositol, cyclohexanedimethanol, pentaerythritol, sorbitol, dipentaerythritol, tripentaerythritol, glycerin, diglycerin and the like. Polymerizable ester compounds (monoesters or polyesters) of these aliphatic polyhydric alcohol compounds and unsaturated carboxylic acids, for example, as described in paragraph numbers [0026] to [0027] of JP-A-2001-139663, for example. The compound of this is mentioned.

  Examples of other polymerizable esters include, for example, vinyl methacrylate, allyl methacrylate, allyl acrylate, aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, and JP-A-57-196231. Those having an aromatic skeleton as described in JP-A-2-226149 and those having an amino group as described in JP-A-1-165613 are also preferably used.

  Furthermore, specific examples of the polymerizable amide formed from an aliphatic polyvalent amine compound and an unsaturated carboxylic acid include methylene bis- (meth) acrylamide, 1,6-hexamethylene bis (meth) acrylamide, and diethylenetriamine tris (meth). Examples include acrylamide, xylylene bis (meth) acrylamide, and those having a cyclohexylene structure described in JP-B No. 54-21726.

Furthermore, a vinylurethane compound containing two or more polymerizable vinyl groups in one molecule (Japanese Patent Publication No. 48-41708), urethane acrylates (Japanese Patent Publication No. 2-16765), an ethylene oxide skeleton Urethane compounds (Japanese Examined Patent Publication No. 62-39418, etc.), polyester acrylates (Japanese Examined Patent Publication No. 52-30490, etc.)), and the Journal of Japan Adhesion Association vol. 20, No. 7, pages 300-308 (1984) The described photocurable monomers and oligomers can also be used.
Two or more kinds of these radically polymerizable polyfunctional monomers may be used in combination.

  Next, a cationically polymerizable group-containing compound (hereinafter, also referred to as “cationic polymerizable compound” or “cationic polymerizable organic compound”) that can be used for forming the binder of the high refractive index layer will be described.

  As the cationically polymerizable compound used in the present invention, any compound that undergoes a polymerization reaction and / or a crosslinking reaction when irradiated with an active energy ray in the presence of an active energy ray-sensitive cationic polymerization initiator can be used. Examples thereof include an epoxy compound, a cyclic thioether compound, a cyclic ether compound, a spiro orthoester compound, a vinyl hydrocarbon compound, and a vinyl ether compound. In the present invention, one or more of the above cationic polymerizable organic compounds may be used.

  As the cationically polymerizable group-containing compound, the number of cationically polymerizable groups in one molecule is preferably 2 to 10, particularly preferably 2 to 5. The molecular weight of the compound is 3000 or less, preferably in the range of 200 to 2000, particularly preferably in the range of 400 to 1500. If the molecular weight is equal to or higher than the lower limit, there is no inconvenience such as a problem of volatilization during the film formation process. If the molecular weight is equal to or lower than the upper limit, compatibility with the composition for forming a high refractive index layer is not caused. Is preferable because it does not cause problems such as deterioration.

  Examples of the epoxy compound include aliphatic epoxy compounds and aromatic epoxy compounds.

  Examples of the aliphatic epoxy compound include polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof, polyglycidyl esters of aliphatic long-chain polybasic acids, homopolymers and copolymers of glycidyl acrylate and glycidyl methacrylate, and the like. Can do. In addition to the above epoxy compounds, for example, monoglycidyl ethers of higher aliphatic alcohols, glycidyl esters of higher fatty acids, epoxidized soybean oil, butyl epoxide stearate, octyl epoxide stearate, epoxidized linseed oil, epoxidized polybutadiene, etc. Can be mentioned. Examples of the alicyclic epoxy compound include polyglycidyl ethers of polyhydric alcohols having at least one alicyclic ring, or unsaturated alicyclic rings (for example, cyclohexene, cyclopentene, dicyclooctene, tricyclodecene, etc. ) Cyclohexene oxide or cyclopentene oxide-containing compound obtained by epoxidizing the containing compound with a suitable oxidizing agent such as hydrogen peroxide or peracid.

  Examples of the aromatic epoxy compound include mono- or polyglycidyl ethers of mono- or polyhydric phenols having at least one aromatic nucleus or their alkylene oxide adducts. As these epoxy compounds, for example, compounds described in paragraphs [0084] to [0086] of JP-A No. 11-242101, paragraph numbers [0044] to [0046] of JP-A No. 10-158385, and the like. And the compounds described.

  Among these epoxy compounds, aromatic epoxides and alicyclic epoxides are preferable, and alicyclic epoxides are particularly preferable in consideration of fast curability. In the present invention, one of the above epoxy compounds may be used alone, but two or more may be used in appropriate combination.

Examples of the cyclic thioether compound include compounds in which the epoxy ring is a thioepoxy ring.
Specific examples of the compound containing an oxetanyl group as a cyclic ether include compounds described in paragraph numbers [0024] to [0025] in JP-A No. 2000-239309. These compounds are preferably used in combination with an epoxy group-containing compound.

  Examples of the spiro orthoester compound include compounds described in JP 2000-506908 A.

Examples of vinyl hydrocarbon compounds include styrene compounds, vinyl group-substituted alicyclic hydrocarbon compounds (vinyl cyclohexane, vinyl bicycloheptene, etc.), compounds described in the above radical polymerizable monomers, propenyl compounds (Journal of Polymer Science: Part A: Polymer). Chemistry, Vol. 32, 2895 (1994) and the like), alkoxy allene compounds (Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 33, 2493 (1995), etc.), vinyl compounds (Journal of PolSolPolPolSolPt A: Polymer Chemistry, Vol. 34, 1015 (1996), JP 2002-29162 A. Etc. described), isopropenyl compound (Journal ofPolymer Science: Part A: Polymer Chemistry, Vol.34,2051 (1996) can be mentioned, wherein, etc.) and the like.
Two or more kinds may be used in appropriate combination.

  The polyfunctional compound is preferably a compound that contains at least one of each selected from the radical polymerizable group and the cationic polymerizable group in the molecule. Examples include compounds described in paragraphs [0031] to [0052] in JP-A-8-277320, compounds described in paragraph [0015] in JP-A-2000-191737, and the like. The compounds used in the present invention are not limited to these.

  The radical polymerizable compound and the cationic polymerizable compound described above are preferably contained in a mass ratio of radical polymerizable compound: cation polymerizable compound in a ratio of 90:10 to 20:80, and 80:20 It is more preferable to contain in the ratio of -30: 70.

  Next, the polymerization initiator used in combination with the binder precursor in the combination (c) will be described in detail.

Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator.
The polymerization initiator is preferably a compound that generates radicals or acids upon irradiation with light and / or heat. The photopolymerization initiator preferably has a maximum absorption wavelength of 400 nm or less. Thus, the handling can be performed under a white light by setting the absorption wavelength to the ultraviolet region. A compound having a maximum absorption wavelength in the near infrared region can also be used.

First, compounds that generate radicals will be described in detail.
The compound that generates radicals preferably used in the present invention refers to a compound that generates radicals by light and / or heat irradiation and initiates and accelerates the polymerization of a compound having a polymerizable unsaturated group. A known polymerization initiator or a compound having a bond with a small bond dissociation energy can be appropriately selected and used. Moreover, the compound which generate | occur | produces a radical can be used individually or in combination of 2 or more types.

  Examples of the compound that generates radicals include conventionally known organic peroxide compounds, thermal radical polymerization initiators such as azo polymerization initiators, organic peroxide compounds (Japanese Patent Laid-Open No. 2001-139663, etc.), amine compounds (Japanese Patent Publication No. Sho) 44-20189), metallocene compounds (described in JP-A-5-83588, JP-A-1-304453, etc.), hexaarylbiimidazole compounds (described in US Pat. No. 3,479,185, etc.), disulfone Examples thereof include photo radical polymerization initiators such as compounds (JP-A-5-239015, JP-A-61-166544, etc.), organic halogenated compounds, carbonyl compounds, and organic boric acid compounds.

  Specific examples of the organic halogenated compounds include Wakabayashi et al., “Bull Chem. Soc Japan” 42, 2924 (1969), US Pat. No. 3,905,815, JP-A-5-27830, M. . P. Examples include compounds described in Hutt “Journal of Heterocyclic Chemistry” 1 (No 3), (1970) ”, and in particular, oxazole compounds substituted with a trihalomethyl group: s-triazine compounds. More preferred are s-triazine derivatives in which at least one mono-, di- or trihalogen-substituted methyl group is bonded to the s-triazine ring.

  Examples of the carbonyl compound include, for example, “Latest UV Curing Technology”, pages 60 to 62 [published by Technical Information Association, 1991], paragraph numbers [0015] to [0016] of JP-A-8-134404, The compounds described in paragraphs [0029] to [0031] of the specification of JP-A-11-217518, and benzoin compounds such as acetophenone, hydroxyacetophenone, benzophenone, thioxan, benzoin ethyl ether, and benzoin isobutyl ether Benzoic acid ester derivatives such as ethyl p-dimethylaminobenzoate and ethyl p-diethylaminobenzoate, benzyldimethyl ketal, and acylphosphine oxide.

  Examples of the organic borate compound include, for example, Japanese Patent Nos. 2764769 and 2002-116539, and Kunz, Martin “Rad Tech'98. Proceeding April 19-22, 1998, Chicago”. Examples of the organic borate described are the compounds described. For example, the compounds described in JP-A-2002-116539, paragraph numbers [0022] to [0027] can be mentioned. Examples of other organic boron compounds include JP-A-6-348011, JP-A-7-128785, JP-A-7-140589, JP-A-7-306527, and JP-A-7-292014. Specific examples include organoboron transition metal coordination complexes.

  These radical generating compounds may be added alone or in combination of two or more. As addition amount, it is 0.1-30 mass% with respect to the whole quantity of a radically polymerizable monomer, Preferably it is 0.5-25 mass%, Most preferably, it can add at 1-20 mass%. Within this range, the temporal stability of the composition for a high refractive index layer is highly polymerizable without problems.

Next, a photoacid generator that can be used as a photopolymerization initiator will be described in detail.
Examples of the acid generator include a photoinitiator for photocationic polymerization, a photodecolorant for dyes, a photochromic agent, a known acid generator used in a microresist, and the like, a known compound, and a mixture thereof. Is mentioned. Examples of the acid generator include organic halogenated compounds, disulfone compounds, onium compounds, etc. Among these, specific examples of organic halogen compounds and disulfone compounds are the same as those described for the compound that generates radicals. Things.

  Examples of the onium compound include diazonium salts, ammonium salts, iminium salts, phosphonium salts, iodonium salts, sulfonium salts, arsonium salts, selenonium salts, and the like, for example, paragraph numbers [0058] to [0058] of [JP-A-2002-29162]. [0059] and the like.

  As the acid generator, an onium salt is particularly preferably used, and among them, a diazonium salt, an iodonium salt, a sulfonium salt, and an iminium salt are preferable from the viewpoint of photosensitivity at the start of photopolymerization, material stability of the compound, and the like.

  Specific examples of onium salts that can be suitably used in the present invention include, for example, an amylated sulfonium salt described in paragraph No. [0035] of JP-A-9-268205 and JP-A-2000-71366. Diaryl iodonium salt or triaryl sulfonium salt described in paragraph numbers [0010] to [0011] of the book, sulfonium salt of thiobenzoic acid S-phenyl ester described in paragraph number [0017] of JP-A-2001-288205, Examples include onium salts described in paragraph numbers [0030] to [0033] of JP-A-2001-133696.

  Other examples of the acid generator include organometallic / organic halides described in JP-A-2002-29162, paragraphs [0059] to [0062], and a photoacid generator having an o-nitrobenzyl type protecting group. And compounds such as compounds that generate photosulfonic acid to generate sulfonic acid (iminosulfonate, etc.).

  These acid generators may be used alone or in combination of two or more. These acid generators are added in an amount of 0.1 to 20% by mass, preferably 0.5 to 15% by mass, particularly preferably 1 to 10% by mass, based on 100 parts by mass of the total mass of the cationically polymerizable monomer. can do. When the addition amount is in the above range, it is preferable from the viewpoint of stability of the composition for high refractive index, polymerization reactivity and the like.

  The composition for forming a high refractive index layer in the present invention is 0.5 to 10% by mass of the radical polymerization initiator or 1 to 10 of the cationic polymerization initiator based on the total mass of the radical polymerizable compound or the cationic polymerizable compound. It is preferable to contain in the ratio of the mass%. More preferably, it contains 1 to 5% by mass of a radical polymerization initiator or 2 to 6% by mass of a cationic polymerization initiator.

  In the composition for forming a high refractive index layer used in the present invention, when a polymerization reaction is carried out by ultraviolet irradiation, a conventionally known ultraviolet spectral sensitizer and chemical sensitizer may be used in combination. Examples of these sensitizers include Michler's ketone, amino acids (such as glycine), and organic amines (such as butylamine and dibutylamine).

  Moreover, when performing a polymerization reaction by near infrared irradiation, it is preferable to use a near infrared spectral sensitizer together. The near-infrared spectral sensitizer used in combination may be a light-absorbing substance having an absorption band in at least a part of the wavelength range of 700 nm or more, and a compound having a molecular extinction coefficient of 10,000 or more is preferable. Furthermore, a value having absorption in the region of 750 to 1400 nm and a molecular extinction coefficient of 20000 or more is preferable. Moreover, it is more preferable that there is a trough of absorption in the visible light wavelength region of 420 nm to 700 nm, and it is optically transparent.

  As the near-infrared spectral sensitizer, various pigments and dyes known as near-infrared absorbing pigments and near-infrared absorbing dyes can be used. Among these, it is preferable to use a conventionally known near-infrared absorber. Commercially available dyes and literature [for example, “Chemical Industry”, May 1986, pages 45-51, “Near Infrared Absorbing Dye”, “Development and Market Trends of Functional Dyes in the 90s”, Chapter 2.3. (1990) CMC, “Special Function Dye” [edited by Ikemori and Pilatani, 1986, issued by CMC Co., Ltd.], J. Am. FABIAN, Chem. Rev. , 92, 1197-1226 (1992)], a catalog published in 1995 by Nippon Sensitive Dye Research Institute, Exciton Inc. Can be used as well as known dyes described in laser dye catalogs and patents issued in 1989.

(B) Organometallic compound containing hydrolyzable functional group and partial condensate of this organometallic compound As a matrix of the high refractive index layer used in the present invention, an organometallic compound containing a hydrolyzable functional group is used. It is also preferable to form a cured film after forming the coating film by a sol-gel reaction.

  Examples of the organometallic compound include compounds composed of Si, Ti, Zr, Al and the like. Examples of the hydrolyzable functional group include an alkoxy group, an alkoxycarbonyl group, a halogen atom, and a hydroxyl group, and an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group is particularly preferable. A preferred organometallic compound is an organosilicon compound represented by the following general formula (1) and a partial hydrolyzate (partial condensate) thereof. In addition, it is a well-known fact that the organosilicon compound represented by the general formula (1) is easily hydrolyzed and subsequently undergoes a dehydration condensation reaction.

Formula (1): (R ^a ) _α -Si (X ₁ ) _4-α
In the general formula (1), R ^a represents a substituted or unsubstituted aliphatic group having 1 to 30 carbon atoms or an aryl group having 6 to 14 carbon atoms. X ₁ represents a halogen atom (a chlorine atom, a bromine atom or the like), an OH group, an OR ^b group, or an OCOR ^b group. Here, R ^b represents a substituted or unsubstituted alkyl group. α represents an integer of 0 to 3, preferably 0, 1 or 2, particularly preferably 1. However, when α is 0, X represents an OR ^b group or an OCOR ^b group.

In the general formula (1), the aliphatic group represented by ^Ra preferably has 1 to 18 carbon atoms (for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, hexadecyl, octadecyl, benzyl group, Phenethyl group, cyclohexyl group, cyclohexylmethyl, hexenyl group, decenyl group, dodecenyl group, etc.). More preferably, it has 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms. ^Examples of the aryl group for R ^a include phenyl, naphthyl, anthranyl and the like, and a phenyl group is preferable.

  Although there is no restriction | limiting in particular as a substituent, Halogen (fluorine, chlorine, bromine, etc.), a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group (methyl, ethyl, i-propyl, propyl, t-butyl etc.), Aryl groups (phenyl, naphthyl, etc.), aromatic heterocyclic groups (furyl, pyrazolyl, pyridyl, etc.), alkoxy groups (methoxy, ethoxy, i-propoxy, hexyloxy, etc.), aryloxy (phenoxy, etc.), alkylthio groups (methylthio) , Ethylthio etc.), arylthio group (phenylthio etc.), alkenyl group (vinyl, 1-propenyl etc.), alkoxysilyl group (trimethoxysilyl, triethoxysilyl etc.), acyloxy group (acetoxy, (meth) acryloyl etc.), alkoxy Carbonyl group (methoxycarbonyl, ethoxycarbonyl) Bonyl etc.), aryloxycarbonyl group (phenoxycarbonyl etc.), carbamoyl group (carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl etc.), acylamino group (acetylamino, benzoylamino) , Acrylicamino, methacrylamino and the like).

  Of these substituents, more preferred are a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, an alkoxysilyl group, an acyloxy group, and an acylamino group, and particularly preferred are an epoxy group and a polymerizable acyloxy group (( (Meth) acryloyl), a polymerizable acylamino group (acrylamino, methacrylamino). These substituents may be further substituted.

As described above, R ^b represents substituted or unsubstituted alkyl, and the description of the substituent in the alkyl group is the same as R ^a .

  As for content of the compound of General formula (1), 10-80 mass% of the total solid of a high refractive index layer is preferable, More preferably, it is 20-70 mass%, Most preferably, it is 30-50 mass%.

  Specific examples of the compound of the general formula (1) include compounds described in paragraph numbers [0054] to [0056] of JP-A No. 2001-166104.

  In the high refractive index layer, the organic binder preferably has a silanol group. It is preferable that the binder has a silanol group because the physical strength, chemical resistance, and weather resistance of the high refractive index layer are further improved. A silanol group is, for example, a binder precursor (such as a curable polyfunctional monomer or polyfunctional oligomer), a polymerization initiator, a high refractive index inorganic fine particle as a binder forming component constituting a coating composition for forming a high refractive index layer. The organosilicon compound represented by the general formula (1) having a crosslinkable or polymerizable functional group is blended in the coating composition together with the dispersant contained in the dispersion liquid, and the coating composition is formed on the transparent protective film. It can be applied to the binder by coating and causing the above-mentioned dispersant, polyfunctional monomer or polyfunctional oligomer, and the organosilicon compound represented by the general formula (1) to undergo a crosslinking reaction or a polymerization reaction.

  The hydrolysis / condensation reaction for curing the organometallic compound is preferably performed in the presence of a catalyst. Catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid, organic acids such as oxalic acid, acetic acid, formic acid, trifluoroacetic acid, methanesulfonic acid and toluenesulfonic acid, inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia , Organic bases such as triethylamine and pyridine, metal alkoxides such as triisopropoxyaluminum, tetrabutoxyzirconium and tetrabutoxytitanate, metal chelate compounds such as β-diketones or β-ketoesters, and the like. Specifically, for example, compounds described in paragraph numbers [0071] to [0083] in JP-A No. 2000-275403 are exemplified.

  The ratio of these catalyst compounds in the composition is 0.01 to 50% by mass, preferably 0.1 to 50% by mass, and more preferably 0.5 to 10% by mass with respect to the organometallic compound. The reaction conditions are preferably adjusted as appropriate depending on the reactivity of the organometallic compound.

  In the high refractive index layer, the matrix preferably has a specific polar group. Specific polar groups include anionic groups, amino groups, and quaternary ammonium groups. Specific examples of the anionic group, amino group and quaternary ammonium group are the same as those described for the dispersant.

  The matrix of the high refractive index layer having a specific polar group, for example, by blending a coating composition for forming a high refractive index layer with a dispersion containing high refractive index inorganic fine particles and a dispersant, as a cured film forming component, A combination of a binder precursor having a specific polar group (such as a curable polyfunctional monomer or polyfunctional oligomer having a specific polar group) and a polymerization initiator, a specific polar group, and a crosslinking or polymerizable functional group Incorporating at least one of the organosilicon compounds represented by the general formula (1) having a group, and further blending a monofunctional monomer having a specific polar group and a crosslinkable or polymerizable functional group as desired, The coating composition is applied onto a transparent protective film, and the above-described dispersant, monofunctional monomer, polyfunctional monomer, polyfunctional oligomer, and / or organosilicon compound represented by the general formula (1) Obtained by crosslinking or polymerization reaction things.

  A monofunctional monomer having a specific polar group is preferable because it can function as a dispersion aid for inorganic fine particles in the coating composition. Furthermore, after coating, a uniform dispersion of inorganic fine particles in the high refractive index layer is maintained by using a binder, a crosslinking reaction or a polymerization reaction with a dispersant, a polyfunctional monomer or polyfunctional oligomer, and a physical reaction. A high refractive index layer excellent in strength, chemical resistance and weather resistance can be produced.

  The amount of the monofunctional monomer having an amino group or a quaternary ammonium group used with respect to the dispersant is preferably 0.5 to 50% by mass, more preferably 1 to 30% by mass. If the binder is formed by crosslinking or polymerization reaction simultaneously with or after the application of the high refractive index layer, the monofunctional monomer can function effectively before the application of the high refractive index layer.

The matrix of the high refractive index layer in the present invention corresponds to (b) of the organic binder described above, and includes those cured and formed from a conventionally known organic polymer containing a crosslinked or polymerizable functional group. . The polymer after the formation of the high refractive index layer preferably has a structure that is further crosslinked or polymerized. Examples of the polymer include polyolefin (made of saturated hydrocarbon), polyether, polyurea, polyurethane, polyester, polyamine, polyamide and melamine resin. Among these, polyolefin, polyether and polyurea are preferable, and polyolefin and polyether are more preferable. The mass average molecular weight of the organic polymer before curing is preferably 1 × 10 ³ to 1 × 10 ⁶ , more preferably 3 × 10 ³ to 1 × 10 ⁵ .

  The organic polymer before curing is preferably a copolymer having a repeating unit having a specific polar group and a repeating unit having a crosslinked or polymerized structure, as described above. The ratio of the repeating unit having an anionic group in the polymer is preferably 0.5 to 99% by mass, more preferably 3 to 95% by mass, and more preferably 6 to 90% by mass in all repeating units. Most preferred. The repeating unit may have two or more anionic groups which may be the same or different.

  When the repeating unit having a silanol group is included, the proportion thereof is preferably 2 to 98 mol%, more preferably 4 to 96 mol%, and most preferably 6 to 94 mol%. When the repeating unit having an amino group or a quaternary ammonium group is included, the proportion is preferably 0.1 to 50% by mass, and more preferably 0.5 to 30% by mass.

  In addition, even if the silanol group, amino group, and quaternary ammonium group are contained in a repeating unit having an anionic group or a repeating unit having a crosslinked or polymerized structure, the same effect can be obtained.

  The proportion of the repeating unit having a crosslinked or polymerized structure in the polymer is preferably 1 to 90% by mass, more preferably 5 to 80% by mass, and most preferably 8 to 60% by mass.

  The matrix formed by crosslinking or polymerizing the binder is preferably formed by applying a composition for forming a high refractive index layer on a transparent protective film and performing crosslinking or polymerization reaction simultaneously with or after application.

(Other composition of high refractive index layer)
In the high refractive index layer of the present invention, other compounds can be appropriately added depending on the application and purpose. For example, when the low refractive index layer is provided on the high refractive index layer, the refractive index of the high refractive index layer is preferably higher than the refractive index of the transparent protective film, and the high refractive index layer includes an aromatic ring and a halogen other than fluorine. When an atom such as a chemical element (for example, Br, I, Cl, etc.), S, N, P, or the like is contained, the refractive index of the organic compound is increased. Therefore, it is obtained by a crosslinking or polymerization reaction of a curable compound containing these. The binder to be used can also be preferably used.

  In addition to the above-mentioned components (inorganic fine particles, polymerization initiators, sensitizers, etc.), the high refractive index layer includes resins, surfactants, antistatic agents, coupling agents, thickeners, anti-coloring agents, and coloring agents. (Pigments, dyes), antifoaming agents, leveling agents, flame retardants, ultraviolet absorbers, infrared absorbers, adhesion promoters, polymerization inhibitors, antioxidants, surface modifiers, conductive metal fine particles, etc. are added. You can also

[Formation of high refractive index layer]
The high refractive index layer is preferably constructed by applying a coating solution of the above-described composition for forming a high refractive index layer directly or via another layer on a transparent protective film described later. The coating solution for the high refractive index layer used in the present invention is prepared by mixing and diluting the inorganic fine particle dispersion, the matrix binder solution, and the additives used as necessary in the coating dispersion medium to a predetermined concentration. .

The coating solution used for coating is preferably filtered before coating. As a filter for filtration, it is preferable to use a filter having a pore diameter as small as possible within a range in which components in the coating solution are not removed. For filtration, a filter having an absolute filtration accuracy of 0.1 to 100 μm, more preferably 0.1 to 25 μm is preferably used. The thickness of the filter is preferably 0.1 to 10 mm, and more preferably 0.2 to 2 mm. In that case, it is preferable to filter at a filtration pressure of 15 kgf / cm ² or less, further 10 kgf / cm ² or less, and particularly 2 kgf / cm ² or less. The filtration filter member is not particularly limited as long as it does not affect the coating solution. Specifically, the same thing as the filtration member of the wet dispersion of an inorganic compound mentioned above is mentioned. It is also preferable to ultrasonically disperse the filtered coating solution immediately before coating to assist defoaming and dispersion holding of the dispersion.

  In the present invention, the high refractive index layer is a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method on the transparent protective film to be described later. It can be prepared by coating by a known thin film forming method such as a gravure coating method, a micro gravure coating method or an extrusion coating method, followed by drying, light and / or heat irradiation. Preferably, curing by light irradiation is advantageous from rapid curing. Furthermore, it is also preferable to perform heat treatment in the latter half of the photocuring treatment.

  The light source of the light irradiation may be any one in the ultraviolet light range or near infrared light. Ultraviolet, high pressure, medium pressure and low pressure mercury lamps, chemical lamps, carbon arc lamps, metal halide lamps may be used as the ultraviolet light source. Xenon lamps, sunlight, etc. Various available laser light sources having a wavelength of 350 to 420 nm may be irradiated as a multi-beam. Further, examples of the near-infrared light source include a halogen lamp, a xenon lamp, and a high-pressure sodium lamp. Various available laser light sources having a wavelength of 750 to 1400 nm may be irradiated in a multi-beam form. When a near infrared light source is used, it may be used in combination with an ultraviolet light source, or light may be irradiated from the transparent protective film surface side opposite to the high refractive index layer coating side. Film curing in the depth direction in the coating layer proceeds without delay with the vicinity of the surface, and a cured film in a uniform cured state is obtained.

In the case of radical photopolymerization by light irradiation, it can be carried out in air or an inert gas, but as much as possible in order to shorten the induction period of polymerization of the radical polymerizable monomer or to sufficiently increase the polymerization rate. It is preferable that the atmosphere has a reduced oxygen concentration. The irradiation intensity of the irradiated ultraviolet rays is preferably about 0.1 to 100 mW / cm ² , and the light irradiation amount on the coating film surface is preferably 100 to 1000 mJ / cm ² . Further, the temperature distribution of the coating film in the light irradiation step is preferably as uniform as possible, preferably within ± 3 ° C., and more preferably controlled within ± 1.5 ° C. In this range, the polymerization reaction in the in-plane and in-layer depth directions of the coating film proceeds uniformly, which is preferable.

The hardness of the high refractive index layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K-5400. Further, the scratch resistance of the high refractive index layer is preferably as the wear amount of the test piece coated with the high refractive index layer before and after the test is smaller in the Taber test according to JIS K-5400. The haze of the high refractive index layer is preferably as low as possible. It is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less.
The film thickness of the high refractive index layer is preferably 30 to 500 nm, and more preferably in the range of 50 to 300 nm. When the high refractive index layer also serves as the hard coat layer, 0.5 to 10 μm is preferable, more preferably 1 to 7 μm, and particularly preferably 2 to 5 μm.

(Medium refractive index layer)
As described above, the antireflection film having at least a three-layer structure preferably has a laminated structure in which the high refractive index layer is composed of two layers having different refractive indexes. That is, the transparent protective film, the lower refractive index layer (medium refractive index layer) of the two high refractive index layers, the higher refractive index layer (high refractive index layer) of the two high refractive index layers, It is preferable to have a layer configuration in the order of a low refractive index layer (outermost layer). The middle refractive index layer has a refractive index intermediate between the refractive index of the transparent protective film and the refractive index of the high refractive index layer. Thus, the refractive index of each refractive index layer is relative. The medium refractive index layer is formed by coating the medium refractive index layer forming composition in the same manner as the high refractive index layer.

  The material constituting the middle refractive index layer in the present invention may be any conventionally known material, but it is preferable to use the same material as the high refractive index layer. The refractive index is easily adjusted by the type and amount of inorganic fine particles, and a thin layer having a thickness of 30 to 500 nm is formed in the same manner as described in the high refractive index layer. More preferably, the film thickness is 50 to 300 nm.

[Hard coat layer]
The hard coat layer can be provided on the surface of the transparent protective film in order to impart physical strength to the antireflection film. In particular, it is preferably provided between the transparent protective film and the high refractive index layer.

  The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of a light and / or heat curable compound. For example, a coating composition containing a polyester (meth) acrylate, a polyurethane (meth) acrylate, a polyfunctional monomer, a polyfunctional oligomer, or a hydrolyzable functional group-containing organometallic compound is coated on a transparent protective film, and a curable compound is applied. It can be formed by a crosslinking reaction or a polymerization reaction.

  The curable functional group is preferably a photopolymerizable functional group, and the hydrolyzable functional group-containing organometallic compound is preferably an organic alkoxysilyl compound. Specifically, those having the same contents as the matrix binder of the high refractive index layer can be mentioned.

  The hard coat layer preferably contains inorganic fine particles having an average primary particle size of 300 nm or less. More preferably, it is 10-150 nm, More preferably, it is 20-100 nm. The average particle diameter here is a mass average diameter. By setting the average particle size of the primary particles to 200 nm or less, a hard coat layer that does not impair the transparency can be formed. The inorganic fine particles have functions of increasing the hardness of the hard coat layer and suppressing curing shrinkage of the coating layer. It is also added for the purpose of controlling the refractive index of the hard coat layer. Specific examples of the composition of the hard coat layer include those described in JP-A Nos. 2002-144913, 2000-9908, and WO 0/46617. The content of the inorganic fine particles in the hard coat layer is preferably 10 to 90% by mass and more preferably 15 to 80% by mass with respect to the total mass of the hard coat layer.

  As described above, the high refractive index layer can also serve as the hard coat layer. When the high refractive index layer also serves as the hard coat layer, it is preferably formed by finely dispersing inorganic fine particles and using the technique described in the high refractive index layer to be contained in the hard coat layer. The film thickness of the hard coat layer can be appropriately designed depending on the application. The film thickness of the hard coat layer is preferably 0.2 to 10 μm, more preferably 0.5 to 7 μm, and particularly preferably 0.7 to 5 μm.

  The hardness of the hard coat layer is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test according to JIS K-5400. Further, the scratch resistance of the hard coat layer is preferably as the wear amount of the test piece before and after the test is smaller in the Taber test according to JIS K-5400.

(Low refractive index layer)
The refractive index of the low refractive index layer in the present invention is preferably in the range of 1.31 to 1.48 for the purpose of imparting antireflection properties.

  The low refractive index layer in the present invention is preferably constructed as an outermost layer having scratch resistance and antifouling properties. The low refractive index layer has a refractive index of 1.17 to 1.37, and contains at least one kind of hollow structure inorganic fine particles having an average particle diameter of 30% to 100% of the thickness of the low refractive index layer. It is characterized by becoming. By using such inorganic fine particles in the low refractive index layer, while suppressing an increase in the refractive index of the layer itself, and without being subjected to restrictions such as saponification treatment for providing a long-time thermosetting or polarizing film, Both low refractive index and high film strength can be achieved.

[Material for forming cured film of low refractive index layer]
Furthermore, the above-mentioned low refractive index layer is a conventionally known silicone and / or fluorine-containing compound as means for realizing a low refractive index, effectively imparting slipperiness to the surface, and greatly improving the scratch resistance. It is preferable to appropriately apply the material for forming a cured film into which is introduced. More preferably, it contains a fluorine-containing compound. In particular, the low refractive index layer in the present invention is composed mainly of a thermosetting and / or light or radiation (for example, ionizing radiation) curable crosslinkable fluorine-containing compound and is composed of a cured fluorine-containing polymer. Is preferred.

  Therefore, in the present invention, the low refractive index layer is produced in the presence of the inorganic fine particles and acid catalyst, and is a hydrolyzate of organosilane represented by the following general formula (2) and / or a partial condensate thereof, And a cured film formed by applying and curing a curable low refractive index layer-forming composition containing at least one fluorine-containing polymer having a curable reactive group.

Formula (2): (R ^c ) _β- Si (X ₂ ) _4-β
(In the formula, R ^c represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. X ₂ represents a hydroxyl group or a hydrolyzable group. Β represents an integer of 1 to 3)

  The composition for forming a low refractive index layer further contains a polyfunctional polymerizable compound containing at least two polymerizable groups selected from radical polymerizable groups and / or cationic polymerizable groups and a polymerization initiator. Is preferred. Hereinafter, the curable composition for forming a low refractive index layer will be described.

[Composition for forming a low refractive index layer]
(Inorganic fine particles with hollow structure)
The low refractive index layer is characterized by using hollow inorganic fine particles (hereinafter sometimes referred to as hollow particles) in order to further reduce the increase in the refractive index. The hollow particles have a refractive index of 1.17 to 1.37, preferably 1.17 to 1.35. The refractive index here represents the refractive index of the entire particle, and does not represent the refractive index of only the outer shell forming the hollow particle. In order to make the hollow particles have a lower refractive index, if an attempt is made to increase the porosity, the thickness of the outer shell becomes thinner and the strength of the particles becomes weaker, so that the refractive index of the hollow particles is 1. It is necessary to make it 17 or more.
The refractive index of these hollow particles can be measured with an Abbe refractometer [manufactured by Atago Co., Ltd.].

When the radius of the cavity in the inorganic fine particle is r _i and the radius of the particle outer shell is r _o , the void ratio w (%) of the hollow particle is calculated according to the following formula (5).
Equation (5): w = (4πr i 3/3) / (4πr o 3/3) × 100
The void ratio of the hollow particles is preferably 10 to 60%, more preferably 20 to 60%, and most preferably 30 to 60%.

  The average particle diameter of the hollow inorganic fine particles is 30% or more and 100% or less of the thickness of the low refractive index layer. Preferably they are 35% or more and 80% or less, More preferably, they are 40% or more and 60% or less. That is, if the thickness of the low refractive index layer is 100 nm, the particle diameter of the hollow particles is 30 nm to 100 nm, preferably 35 nm to 80 nm, more preferably 40 nm to 60 nm. When the average particle size is in the above range, the strength of the film is sufficiently expressed, which is preferable.

As the inorganic fine particles used in the low refractive index layer, particles such as silicon dioxide (silica) and fluorine-containing particles (magnesium fluoride, calcium fluoride, barium fluoride) are preferable. Particularly preferred are silicon dioxide (silica) particles.
The shape of the inorganic fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape, a short fiber shape, a ring shape, or an indefinite shape.

(Inorganic fine particles of small size)
In addition, at least one kind of inorganic fine particles having an average particle size of less than 25% of the thickness of the low refractive index layer (hereinafter referred to as “inorganic fine particles having a small size particle size”) is used as an inorganic particle having a particle size larger than the above. It is preferable to use in combination with fine particles (hereinafter, the essential inorganic fine particles of the present invention may be referred to as “large-sized particle size inorganic fine particles”). The inorganic fine particles having a small particle size may not have a hollow structure.

  Since the inorganic fine particles having a small particle size can exist in the gaps between the inorganic fine particles having a large particle size, they can contribute as a retaining agent for the inorganic fine particles having a large particle size, which is preferable. Moreover, it is preferable also in terms of raw material costs.

  When the low refractive index layer is 100 nm, the average particle size of the small-sized inorganic fine particles is preferably 1 nm to 20 nm, more preferably 5 nm to 15 nm, and particularly preferably 10 nm to 15 nm.

  The amount of the inorganic fine particles having a small size is preferably 5 to 100 parts by mass, more preferably 10 to 80 parts by mass with respect to 100 parts by mass of the inorganic fine particles (hollow particles) having a large size.

  Specific examples of the compound are the same as those exemplified for the hollow particles. Particularly preferred is an oxide of silicon.

(Dispersion of inorganic fine particles)
Any of the above-mentioned hollow particles and small-sized inorganic fine particles may be dispersed or stabilized in the dispersion or in the curable composition for forming a low refractive index layer, or a binder component. In order to enhance the affinity and binding properties, physical surface treatment such as plasma discharge treatment and corona discharge treatment, and chemical surface treatment with a surfactant or a coupling agent may be performed. The use of a coupling agent is particularly preferred. As the coupling agent, an alkoxy metal compound (eg, titanium coupling agent, silane coupling agent) is preferably used. Of these, treatment with a silane coupling agent is particularly preferred.

The above-mentioned coupling agent is used as a surface treatment agent for the inorganic fine particles of the low refractive index layer in advance for surface treatment prior to the preparation of the curable composition solution. It is preferable to make it contain in this layer.
The inorganic fine particles are preferably dispersed in the medium in advance before the surface treatment in order to reduce the load of the surface treatment.

  The blending ratio of the inorganic fine particles is preferably 5 to 90 parts by mass with respect to 100 parts by mass of the total composition of the low refractive index layer, from the viewpoint of the transparency of the film, the strength of the film, and the like. More preferably. Moreover, when mix | blending a hollow particle and another particle, 5-95 mass parts is preferable, and, as for the hollow particle in all the particles, More preferably, it is 10-90 mass parts, Most preferably, it is 30-80 mass parts.

(Fluoropolymer)
As described above, the low refractive index layer in the present invention is composed of a fluorine-containing polymer formed and cured mainly of a thermosetting and / or light or radiation (for example, ionizing radiation) curable fluorine-containing compound. It is preferable.

  In the present invention, “mainly containing a fluorine-containing compound” means that the fluorine-containing compound contained in the low refractive index layer is 50% by mass or more based on the total mass of the low refractive index layer. More preferably, it is contained in an amount of at least mass%.

  The refractive index of the fluorine-containing compound is preferably 1.35 to 1.50. More preferably, it is 1.36-1.47. Moreover, it is preferable that a fluorine-containing compound contains a fluorine atom in 35-80 mass%.

  Examples of the fluorine-containing compound include a fluorine-containing polymer, a fluorine-containing surfactant, a fluorine-containing ether, and a fluorine-containing silane compound. Specifically, for example, Japanese Patent Application Laid-Open No. 9-222503, paragraph numbers [0018] to [0026], Japanese Patent Application Laid-Open No. 11-38202, paragraph numbers [0019] to [0030], Japanese Patent Application Laid-Open No. 2001-40284, paragraph number [0027]. To [0028] and the like.

The fluorine-containing polymer used for the low-refractive index layer includes a repeating structural unit containing a fluorine atom, a repeating structural unit containing a crosslinkable or polymerizable functional group, and a co-polymer consisting of a repeating structural unit composed of other substituents. Coalescence is preferred. That is, a copolymer of a fluorinated monomer and a monomer for imparting a crosslinkable group, that is, a fluorinated polymer having a curable reactive group that is a crosslinkable or polymerizable functional group is preferred, and other monomers are also co-polymerized. A polymerized fluorine-containing polymer may be used.
The crosslinkable or polymerizable functional group may be any conventionally known functional group.

  Examples of the crosslinkable functional group include isocyanate group, epoxy group, aziridine group, oxazoline group, aldehyde group, carbonyl group, hydrazine group, carboxyl group, methylol group and active methylene group. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane, and metal alkoxide such as tetramethoxysilane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. That is, in the present invention, the crosslinkable functional group may not react immediately but may exhibit reactivity as a result of decomposition. These compounds having a crosslinkable functional group can form a crosslinked structure by heating after coating.

  Examples of the polymerizable functional group include a radical polymerizable group and a cationic polymerizable group. Preferably, radically polymerizable groups (for example, (meth) acryloyl group, styryl group, vinyloxy group, etc.) and cationic polymerizable groups (for example, epoxy group, thioepoxy group, oxetanyl group, etc.) are mentioned.

  The other repeating structural unit is preferably a repeating structural unit formed by a hydrocarbon-based copolymer component for solubilization of a solvent, and a fluorine-based polymer in which such a structural unit is introduced in an amount of about 50% by mass in the whole polymer. Is preferred. In this case, it is preferable to combine with a silicone compound.

  The silicone compound is a compound having a polysiloxane structure, preferably containing a curable functional group or a polymerizable functional group in the polymer chain and having a crosslinked structure in the film. Examples thereof include reactive silicones such as “Silaplane” [manufactured by Chisso Corporation], and compounds containing silanol groups at both ends of the polysiloxane structure described in JP-A-11-258403.

  The crosslinking or polymerization reaction of the fluorine-containing polymer having a crosslinking or polymerizable group is preferably carried out by irradiating or heating the curable composition for forming the outermost layer simultaneously with or after coating.

  In this case, examples of the polymerization initiator that can be used include the same as those described for the high refractive index layer.

  When the polymerization reaction is performed by ultraviolet irradiation, a conventionally known ultraviolet spectral sensitizer or chemical sensitizer may be used in combination. Examples include Michler's ketone, amino acids (such as glycine), and organic amines (such as butylamine and dibutylamine).

  Other monomers that may be copolymerized are not particularly limited. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate) , 2-ethylhexyl acrylate), methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyltoluene, α-methylstyrene, etc.), Vinyl ethers (such as methyl vinyl ether), vinyl esters (such as vinyl acetate, vinyl propionate, vinyl cinnamate), acrylamides (such as Nt-butylacrylamide, N-cyclohexylacrylamide), methacrylamido Kind, and acrylonitrile derivatives.

  As described in JP-A-10-25388 and JP-A-10-147739, a curing agent may be appropriately used in combination with the above polymer.

  The low refractive index layer is a sol-gel cured film formed by curing an organometallic compound such as a silane coupling agent and a specific fluorine-containing hydrocarbon group-containing silane coupling agent in the presence of a catalyst in a condensation reaction. Are also preferably used.

  For example, polyfluoroalkyl group-containing silane compounds or partially hydrolyzed condensates thereof (compounds described in JP-A-58-142958, JP-A-58-147483, JP-A-58-147484, etc.), JP-A-9-157582 Perfluoroalkyl group-containing silane coupling agents described in Japanese Patent Publication No. JP-A-2000-117902, and silyl compounds containing a poly "perfluoroalkyl ether" group which is a fluorine-containing long chain group (JP 2000-117902 A, JP 2001-48590 A, And the like described in JP-A-2002-53804).

  Examples of the catalyst to be used in combination include conventionally known compounds, and those described in the above documents are preferably exemplified.

  As the fluorine-containing polymer having a curable reactive group particularly useful in the present invention, a copolymer of a perfluoro compound selected from perfluoroolefin, perfluorocycloolefin, and non-conjugated perfluorodiene and vinyl ethers or vinyl esters. Is mentioned. In particular, it preferably has a group capable of undergoing crosslinking reaction alone [a radical reactive group such as a (meth) acryloyl group, a ring-opening polymerizable group such as an epoxy group or an oxetanyl group]. These cross-linking reactive group-containing polymer units preferably occupy 5 to 70 mol%, particularly preferably 30 to 60 mol% of the total polymerized units of the polymer.

  A preferred embodiment of the copolymer used in the present invention is a compound represented by the following general formula (3).

  In formula (3), component [F] represents the following component (pf1), component (pf2), or component (pf3).

In the component (pf1), R _f represents an F atom or a perfluoroalkyl group having 1 to 3 carbon atoms.

In the component (pf2), R ₃ and R ₄ may be the same or different and each represents a fluorine atom or a —C _j F _{2j + 1} group, j is an integer of 1 to 4 (preferably j is 1 or 2). ). a represents 0 or 1, and b represents an integer of 2 to 5. c represents 0 or 1; When a and / or c is 0, each represents a single bond.

In the component (pf3), R ₅ and R ₆ each represent a fluorine atom or a —CF ₃ group. a represents 0 or 1 like the said component (pf2). d represents 0 or 1, e represents 0 or an integer of 1 to 4, f represents 0 or 1, and g represents an integer of 0 or 1 to 5. When d, e, f and / or g is 0, each represents a single bond. (E + f + g) is an integer in the range of 1-6.

In the general formula (3), B represents a linking group having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 2 to 4 carbon atoms, and has a branched structure even if it is a straight chain. It may also have a ring structure. Further, it may have a heteroatom selected from O, N and S. Preferred examples of the linking group B include * — (CH ₂ ) ₂ —O — **, * — (CH ₂ ) ₂ —NH — **, * — (CH ₂ ) ₄ —O — **, * — (CH ₂ ) ₆ —O — **, * — (CH ₂ ) ₂ —O— (CH ₂ ) ₂ —O — **, * —CONH— (CH ₂ ) ₃ —O — **, * —CH ₂ CH (OH) CH ₂ —O — **, * —CH ₂ CH ₂ OCONH (CH ₂ ) ₃ —O — ** (where * represents a connecting site on the polymer main chain side, and ** represents ( Represents a connecting site on the side of (meth) acryloyl group). u represents 0 or 1;

In the general formula (3), X ₃ represents a hydrogen atom or a methyl group. From the viewpoint of curing reactivity, a hydrogen atom is more preferable.

  Further, in the general formula (3), A represents a repeating unit derived from an arbitrary vinyl monomer, and is not particularly limited as long as it is a constituent component of a monomer copolymerizable with the monomer corresponding to the component [F]. Can be selected as appropriate from various viewpoints such as adhesion to the surface, Tg of the polymer (contributing to film hardness), solubility in solvents, transparency, slipperiness, dustproof / antifouling properties, etc. You may be comprised by the 1 or several vinyl monomer.

  Preferred examples of A include methyl vinyl ether, ethyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, isopropyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, glycidyl vinyl ether, vinyl ethers such as allyl vinyl ether, vinyl acetate, and vinyl propionate. , Vinyl esters such as vinyl butyrate, methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycidyl methacrylate, allyl (meth) acrylate, (meth) acryloyloxypropyltrimethoxysilane ( (Meth) acrylates, styrene, styrene derivatives such as p-hydroxymethylstyrene, crotonic acid, maleic acid, itaco Can be mentioned unsaturated carboxylic acids and derivatives thereof such as acid, more preferably a vinyl ether derivative, vinyl ester derivatives, particularly preferably a vinyl ether derivative.

  x, y, and z represent mol% of each constituent component, and represent values satisfying 30 ≦ x ≦ 60, 5 ≦ y ≦ 70, and 0 ≦ z ≦ 65. Preferably, 35 ≦ x ≦ 55, 30 ≦ y ≦ 60, and 0 ≦ z ≦ 20, and particularly preferably 40 ≦ x ≦ 55, 40 ≦ y ≦ 55, and 0 ≦ z ≦ 10. However, x + y + z = 100.

  Particularly preferably, in the general formula (3), the component [F] is the component (pf1), and specifically described in paragraph numbers “0043” to “0047” of JP-A-2004-45462. Compounds and the like.

(Organosilane compound)
Next, the hydrolyzate of organosilane represented by the general formula (2) and / or the partial condensate thereof will be described.
Formula (2): (R ^c ) _β- Si (X ₂ ) _4-β

In the general formula (2), R ^c represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 6 carbon atoms, and examples thereof include methyl, ethyl, propyl, isopropyl, hexyl, decyl, hexadecyl and the like. . Examples of the aryl group include phenyl and naphthyl, and a phenyl group is preferable.

X ₂ represents a hydroxyl group or a hydrolyzable group, for example, an alkoxy group (preferably an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group or an ethoxy group), a halogen atom (for example, Cl, Br, I Etc.), and R ^d COO (R ^d is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, such as CH ₃ COO, C ₂ H ₅ COO, etc.). Is an alkoxy group, particularly preferably a methoxy group or an ethoxy group.
β represents an integer of 1 to 3, preferably 1 or 2, and particularly preferably 1.

When R ^c or X ₂ there are a plurality, the plurality of R ^c or X ₂ may be different even in the same, respectively.

The substituent contained in R ^c is not particularly limited, but is a halogen atom (fluorine, chlorine, bromine, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl, ethyl, i-propyl, propyl, t-butyl etc.), aryl groups (phenyl, naphthyl etc.), aromatic heterocyclic groups (furyl, pyrazolyl, pyridyl etc.), alkoxy groups (methoxy, ethoxy, i-propoxy, hexyloxy etc.), aryloxy (phenoxy etc.) ), Alkylthio groups (methylthio, ethylthio, etc.), arylthio groups (phenylthio, etc.), alkenyl groups (vinyl, 1-propenyl, etc.), acyloxy groups (acetoxy, acryloyloxy, methacryloyloxy, etc.), alkoxycarbonyl groups (methoxycarbonyl, ethoxy) Carbonyl, etc.), aryloxy Carbonyl groups (phenoxycarbonyl, etc.), carbamoyl groups (carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl, etc.), acylamino groups (acetylamino, benzoylamino, acrylicamino, methacrylamino) Etc.), and these substituents may be further substituted.

When there are a plurality of R ^{c s} , at least one is preferably a substituted alkyl group or a substituted aryl group.

  Among the organosilane compounds represented by the general formula (2), an organosilane compound having a vinyl polymerizable substituent represented by the following general formula (2-1) is preferable.

In the general formula (2-1), R ₇ represents a hydrogen atom, a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom, or a chlorine atom. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group. A hydrogen atom, a methyl group, a methoxy group, a methoxycarbonyl group, a cyano group, a fluorine atom and a chlorine atom are preferred, a hydrogen atom, a methyl group, a methoxycarbonyl group, a fluorine atom and a chlorine atom are more preferred, and a hydrogen atom and a methyl group Is particularly preferred.

Y represents a single bond or * -COO-**, * -CONH-** or * -O-**, preferably a single bond, * -COO-** or * -CONH-**, * -COO-** is more preferable, and * -COO-** is particularly preferable. Here, * represents a position bonded to = C (R ₇ )-, and ** represents a position bonded to D.

  D represents a divalent linking chain. Specifically, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group having a linking group (for example, ether, ester, amide, etc.) inside, and a linking group inside. A substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, an alkylene group having a linking group therein is preferred, an unsubstituted alkylene group, an unsubstituted arylene group Further, an alkylene group having an ether or ester linking group inside is more preferred, an unsubstituted alkylene group, and an alkylene group having an ether or ester linking group inside is particularly preferred. Examples of the substituent include a halogen, a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, and an aryl group, and these substituents may be further substituted.

γ represents 0 or 1. When X ₄ there are a plurality, it may be different even multiple X ₄ are the same, respectively. γ is preferably 0. R ^c has the same meaning as in formula (2), preferably a substituted or unsubstituted alkyl group or an unsubstituted aryl group, and more preferably an unsubstituted alkyl group or an unsubstituted aryl group. X ₄ represents the same as X _{2 in} formula (2), preferably a halogen atom, a hydroxyl group, or an unsubstituted alkoxy group, more preferably a chlorine atom, a hydroxyl group, or an unsubstituted alkoxy group having 1 to 6 carbon atoms, A hydroxyl group and an alkoxy group having 1 to 3 carbon atoms are more preferable, and a methoxy group is particularly preferable.

  Two or more compounds of the general formula (2) and the general formula (2-1) may be used in combination. Although the specific example of a compound represented by General formula (2) and General formula (2-1) below is shown, it is not limited to these.

  The hydrolyzate and / or partial condensate of an organosilane compound is generally produced by treating the organosilane compound in the presence of a catalyst. Catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as oxalic acid, acetic acid, formic acid, methanesulfonic acid and toluenesulfonic acid; inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine, Examples thereof include organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium; metal chelate compounds having a metal such as Zr, Ti or Al as a central metal. In the present invention, it is preferable to use acid catalysts of inorganic acids and organic acids. Of these, hydrochloric acid and sulfuric acid are preferable for inorganic acids, and organic acids preferably have an acid dissociation constant [pKa value (25 ° C.)] of 4.5 or less in water. Furthermore, hydrochloric acid, sulfuric acid, and acids in water are preferable. An organic acid having a dissociation constant of 3.0 or less is preferable, particularly an organic acid having an acid dissociation constant of 2.5 or less in hydrochloric acid, sulfuric acid or water, and an organic acid having an acid dissociation constant of 2.5 or less in water. More specifically, methanesulfonic acid, oxalic acid, phthalic acid, and malonic acid are more preferable, and oxalic acid is particularly preferable.

  5-100 mass% is preferable, the usage-amount of the sol component of the organosilane with respect to a fluorine-containing polymer in a low refractive index layer has more preferable 5-40 mass%, 8-35 mass% is still more preferable, 10-30 mass % Is particularly preferred. If the amount used is too small, it is difficult to obtain the effects of the present invention. However, if the amount used is less than the upper limit, problems such as excessive increase in the refractive index and deterioration of the film shape / surface shape do not occur. Since the excellent effect of the present invention can be exhibited, it is preferable to use an appropriate amount within this range.

(Polyfunctional polymerizable compound)
As described above, a polyfunctional polymerizable compound can be further added to the curable composition for forming the low refractive index layer.

  As the polyfunctional polymerizable compound, any of radical polymerizable functional group and / or cationic polymerizable functional group may contain two or more polymerizable groups. Examples of the radical polymerizable functional group include an ethylenically unsaturated group such as a (meth) acryloyl group, a vinyloxy group, a styryl group, and an allyl group, and among them, a (meth) acryloyl group is preferable. It is preferable to contain a polyfunctional monomer containing two or more radically polymerizable groups in the molecule.

  The radical polymerizable polyfunctional monomer having a radical polymerizable group is preferably selected from compounds having at least two terminal ethylenically unsaturated bonds. Preferred is a compound having 2 to 6 terminal ethylenically unsaturated bonds in the molecule. Such a compound group is widely known in the polymer material field, and these can be used without particular limitation in the present invention. These can have chemical forms such as monomers, prepolymers, ie dimers, trimers and oligomers, or mixtures thereof and copolymers thereof.

  As the cationically polymerizable compound used in the present invention, any compound that undergoes a polymerization reaction and / or a crosslinking reaction when irradiated with an active energy ray in the presence of an active energy ray-sensitive cationic polymerization initiator can be used. Examples thereof include an epoxy compound, a cyclic thioether compound, a cyclic ether compound, a spiro orthoester compound, a vinyl hydrocarbon compound, and a vinyl ether compound. In the present invention, one or more of the above cationic polymerizable organic compounds may be used. As the cationically polymerizable group-containing compound, the number of cationically polymerizable groups in one molecule is preferably 2 to 10, particularly preferably 2 to 5. Specific contents of these radical polymerizable compounds and cationic polymerizable compounds include those similar to the polyfunctional monomers and oligomers described in the high refractive index layer.

  The radical polymerizable compound and the cationic polymerizable compound described above are preferably contained in a mass ratio of radical polymerizable compound: cation polymerizable compound in a ratio of 90:10 to 20:80, and 80:20 to More preferably, it is contained at a ratio of 30:70. Moreover, it is preferable that the compounding quantity of the said polyfunctional polymerizable compound containing a radically polymerizable compound and a cationically polymerizable compound shall be 0.1-20 mass parts with respect to 100 mass parts of said fluoropolymers.

(Other additives)
In addition to the components described above, the low refractive index layer in the present invention is provided with an anti-fouling property of a known silicone compound or fluorine compound for the purpose of imparting antifouling properties, water resistance, chemical resistance, slipping properties and the like. It is preferable that a soiling agent, a slipping agent and the like are appropriately added. When these additives are added, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the curable composition for forming the low refractive index layer, more preferably 0.05 to 10%. It is a case where it is added in the range of mass%, particularly preferably 0.1 to 5 mass%.

  Preferable examples of the silicone compound include those having a substituent at the end of the compound chain and / or the side chain, containing a plurality of dimethylsilyloxy units as repeating units. The compound chain containing dimethylsilyloxy as a repeating unit may contain a structural unit other than dimethylsilyloxy. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, fluoroalkyl group, polyoxyalkylene group, carboxyl group, amino group, etc. Groups.

  Although there is no restriction | limiting in particular in the molecular weight of a silicone type compound, It is preferable that it is 100,000 or less, It is especially preferable that it is 50,000 or less, It is most preferable that it is 3000-30000. Although there is no restriction | limiting in particular also in silicone atom content of a silicone type compound, It is preferable that it is 18.0 mass% or more, It is especially preferable that it is 25.0-37.8 mass%, 30.0-37. Most preferably, it is 0.0 mass%.

  Examples of preferred silicone compounds include “X-22-174DX”, “X-22-2426”, “X-22-164b”, “X22-164C”, “X-22-170DX”, “X- 22-176D "," X-22-1821 "[trade name: manufactured by Shin-Etsu Chemical Co., Ltd.];" FM-0725 "," FM-7725 "," DMS-U22 "," RMS-033 ", “RMS-083”, “UMS-182” [trade name: manufactured by Chisso Corporation] and the like are exemplified, but not limited thereto.

As the fluorine compound, a compound having a fluoroalkyl group is preferable. The fluoroalkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and a straight chain [eg, —CF ₂ CF ₃ , —CH ₂ (CF ₂ ) ₄ H, —CH ₂ (CF ₂ ) ₈ CF ₃ , —CH ₂ CH ₂ (CF ₂ ) ₄ H, etc.], even branched structures [eg, —CH (CF ₃ ) ₂ , —CH ₂ CF (CF ₃ ) ₂ , —CH (CH ₃ ) CF ₂ CF ₃ , —CH (CH ₃ ) (CF ₂ ) ₅ CF ₂ H, etc.], an alicyclic structure (preferably a 5- or 6-membered ring such as a perfluorocyclohexyl group). , A perfluorocyclopentyl group or an alkyl group substituted with these, and may have an ether bond (for example, —CH ₂ OCH ₂ CF ₂ CF ₃ , —CH ₂ CH ₂ OCH ₂ C). ₄ F ₈ H, —CH ₂ CH ₂ OCH ₂ CH ₂ C ₈ F ₁₇ , —CH ₂ C H ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ H, etc.). A plurality of the fluoroalkyl groups may be contained in the same molecule.

  The fluorine-based compound preferably further has a substituent that contributes to bond formation or compatibility with the film of the low refractive index layer. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like.

  The fluorine-based compound may be a polymer or an oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited and is used. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferable fluorine-based compounds include “R-2020”, “M-2020”, “R-3833”, “M-3833” [trade name: manufactured by Daikin Chemical Industries, Ltd.]; "F-171", "Megafuck F-172", "Megafuck F-179A", "Defenser MCF-300" [trade name: manufactured by Dainippon Ink, Ltd.] It is not something.

  For the purpose of imparting properties such as dust resistance and antistatic properties, a dustproof agent, an antistatic agent, and the like such as known cationic surfactants or polyoxyalkylene compounds can be added as appropriate. These dustproofing agent and antistatic agent may contain the structural unit as a part of the function in the above-mentioned silicone compound or fluorine compound. When these are added as additives, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the curable composition, more preferably in the range of 0.05 to 10% by mass. Particularly preferred is 0.1 to 5% by mass. Examples of preferable compounds include “Megafac F-150” [trade name: manufactured by Dainippon Ink Co., Ltd.], “SH-3748” [trade name: manufactured by Toray Dow Corning Co., Ltd.], and the like. It is not limited to these.

  The low refractive index layer may also contain microvoids. Specific examples include the contents described in JP-A-9-222502, JP-A-9-288201, JP-A-11-6902, and the like.

  Furthermore, in the present invention, organic fine particles can also be used. Examples of the organic fine particles include compounds described in paragraphs [0020] to [0038] of JP-A No. 11-3820, and the shape thereof is The same as the above-mentioned inorganic fine particles.

  The thickness of the low refractive index layer is preferably 0.03 to 0.2 μm, more preferably 0.05 to 0.15 μm.

[Properties of low refractive index layer]
The low refractive index layer in the present invention preferably has a surface energy of 26 mN / m or less, more preferably 15 to 25.8 mN / m. It is preferable from the viewpoint of antifouling property to make the surface energy within this range.

  In addition, the low refractive index layer exhibits an antifouling effect as long as it is a cured film made of a fluoropolymer containing a thermosetting or light or radiation (for example, ionizing radiation) curable crosslinkable fluorine-containing compound. Therefore, it is preferable. In particular, it is preferable that the fluorine-containing compound contained in the low refractive index layer as the outermost layer is 50% by mass or more with respect to the total mass of the outermost layer because the entire film surface exhibits stable and uniform characteristics.

  The surface energy of a solid can be determined by a contact angle method, a wet heat method, and an adsorption method as described in “Basics and Applications of Wetting” (issued by Realize 1989.12.10). In the case of the film of the present invention, it is preferable to use a contact angle method. Specifically, two types of solutions having known surface energies are dropped on the transparent protective film surface of the polarizing plate, and the tangent line drawn on the droplet and the film surface at the intersection of the surface of the droplet and the film surface. The surface angle of the film is defined as the contact angle, and the surface energy of the film can be calculated by calculation. The contact angle of the outermost layer surface with water is preferably 90 ° or more, more preferably 95 ° or more, and particularly preferably 100 ° or more.

  The dynamic friction coefficient on the surface of the low refractive index layer is preferably 0.25 or less, more preferably 0.05 to 0.25, and particularly preferably 0.03 to 0.15. The dynamic friction coefficient described here refers to a dynamic friction coefficient between a surface and a stainless steel hard sphere having a diameter of 5 mm when a load of 0.98 N is applied to a stainless steel hard sphere having a diameter of 5 mm and the surface is moved at a speed of 60 cm / min. .

  The hardness of the low refractive index layer is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test according to JIS K-5400. The scratch resistance of the low refractive index layer is preferably as the wear amount in the Taber test according to JIS K-6902 is smaller.

[Formation of each layer of antireflection film]
Each layer of the antireflection film is formed by a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating, a micro gravure method, an extrusion coating method (US Pat. No. 2,681,294). It can be formed by coating using a method. The microgravure method and the gravure method are preferable from the viewpoint that drying unevenness can be reduced by minimizing the wet coating amount, and the gravure method is particularly preferable from the viewpoint of film thickness uniformity in the width direction. When applying, two or more layers may be applied simultaneously. Examples of the simultaneous application method include those described in US Pat. Nos. 2,761,791, 2,941,898, 3,508,947, and 3,526,528 and Yuji Harasaki, Coating Engineering, page 253, Asakura Shoten (1973). .

[Anti-glare function (anti-glare)]
The antireflection film may have an antiglare function that scatters external light. The antiglare function is obtained by forming irregularities on the surface of the antireflection film. When the antireflection film has an antiglare function, the haze of the antireflection film is preferably 3 to 50%, more preferably 5 to 40%, and most preferably 7 to 20%.

The antiglare property correlates with the average surface roughness (Ra) of the surface. It is preferable that the surface roughness is 1 mm ² randomly taken out from an area of 100 cm ² , and the average surface roughness (Ra) is 0.01 to 0.4 μm per 1 mm ² area of the extracted surface. More preferably, it is 0.03-0.3 micrometer, More preferably, it is 0.05-0.25 micrometer, Most preferably, it is 0.07-0.2 micrometer.
The average surface roughness (Ra) is measured according to JIS B-0601-1994.

  The concave and convex shapes on the surface of the antireflection film used in the present invention can be evaluated by an atomic force microscope (AFM).

  As a method for forming irregularities on the surface of the antireflection film, any method can be applied as long as these surface shapes can be sufficiently maintained. For example, fine particles are used in the low refractive index layer, thereby forming irregularities on the film surface (for example, JP 2000-271878 A), lower layers of the low refractive index layer (high refractive index layer, medium refractive index) The surface irregularity film is formed by adding a small amount (0.1 to 50% by mass) of relatively large particles (particle size 0.05 to 5 μm) to the rate layer or hard coat layer), and these shapes are maintained thereon. Then, a method of providing a low refractive index layer (for example, JP 2000-281410 A, JP 2000-95893 A, etc.), a method of physically transferring a concavo-convex shape to the surface after coating a low refractive index layer [ For example, an embossing method (for example, JP-A-63-278839, JP-A-11-183710, JP-A-2000-275401, etc.), release paper transfer method (for example, JP No. 3332534), Particles Leh transfer method (e.g., JP-A 6-87632 Patent Publication), and the like.

  When the anti-glare layer is formed by adding particles to any layer of the antireflection film, the particles for the anti-glare layer used for the anti-glare layer include particles having an average particle size in the range of 0.2 to 10 μm. preferable. The average particle diameter here is the mass average diameter of secondary particles (or primary particles when the particles are not aggregated). Examples of the antiglare layer particles include inorganic fine particles and organic particles. Specific examples of the inorganic fine particles include particles such as silicon dioxide, titanium dioxide, zirconium oxide, aluminum oxide, tin oxide, ITO, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin and calcium sulfate. Silicon dioxide and aluminum oxide are preferred.

  The organic particles are preferably resin particles. Specific examples of the resin particles include particles made from silicone resin, melamine resin, benzoguanamine resin, polymethyl methacrylate resin, polystyrene resin, and polyvinylidene fluoride resin. Preferred are particles made from melamine resin, benzoguanamine resin, polymethyl methacrylate resin, polystyrene resin, and particularly preferred are particles made from polymethyl methacrylate resin, benzoguanamine resin, polystyrene resin.

  The particles for the antiglare layer used for the antiglare layer in order to form irregularities are preferably resin particles. The average particle diameter of the particles is preferably 0.5 to 7.0 μm, more preferably 1.0 to 5.0 μm, and particularly preferably 1.5 to 4.0 μm. The refractive index of the particles is preferably 1.35 to 1.80, more preferably 1.40 to 1.75, and still more preferably 1.45 to 1.75. The narrower the particle size distribution, the better. The S value indicating the particle size distribution of the particles is represented by the following mathematical formula (6), preferably 2 or less, more preferably 1.0 or less, and particularly preferably 0.7 or less.

Equation (6): S = (D 0.9 -D 0.1) / D 0.5
D _0.1 : Particle diameter equivalent to 10% of the integrated value of the volume converted particle diameter D _0.5 : Particle diameter equivalent to 50% of the integrated value of the volume converted particle diameter D _0.9 : Particle diameter equivalent to 90% of the integrated value of the volume converted particle diameter

  Further, as the particles for the antiglare layer, it is preferable to use translucent particles, and the refractive index is not particularly limited, but is almost the same as the refractive index of the antiglare layer (the difference in refractive index is 0.00. 005) or 0.02 or more. By making the refractive index of the particles and the refractive index of the antiglare layer substantially the same, the contrast when the antireflection film is mounted on the image display surface is improved. In addition, by adding a difference in refractive index between the refractive index of the particles and the refractive index of the antiglare layer, the visibility (glare failure, viewing angle characteristics, etc.) when the antireflection film is mounted on the liquid crystal display surface is improved. The

  In the case of adding a difference in refractive index between the refractive index of the particles and the refractive index of the antiglare layer, it is preferably 0.02 to 0.5, more preferably 0.03 to 0.4, and particularly preferably 0. 0.05 to 0.3.

  As the translucent particles, two or more different translucent particles may be used in combination. When two or more kinds of translucent particles are used, the translucent particles having the highest refractive index and the translucent particles having the lowest refractive index are used to effectively exert the refractive index control by mixing a plurality of types of particles. The difference in refractive index with the active particles is preferably 0.02 or more and 0.10 or less, and particularly preferably 0.03 or more and 0.07 or less. Further, it is possible to impart an antiglare property with a light-transmitting particle having a larger particle diameter and to impart another optical characteristic with a light-transmitting particle having a smaller particle diameter. For example, when a transparent protective film coated with an antireflection film is attached to a high-definition display of 133 ppi or more, it is required that there is no optical performance defect called glare. Glare is derived from the fact that the unevenness of the film surface (which contributes to antiglare properties) causes the pixels to be enlarged or reduced and loses brightness uniformity, but is smaller than the light-transmitting particles that impart antiglare properties. The diameter can be greatly improved by using translucent particles different from the refractive index of the translucent resin as the matrix binder.

  The amount of the antiglare layer particles used is preferably 3 to 75% by mass in the solid content of the antiglare layer.

  The particles imparting antiglare properties can be contained in any layer constructed in the antireflection film, preferably a hard coat layer, a low refractive index layer, or a high refractive index layer, particularly preferably a hard coat layer. A high refractive index layer. It may be added to a plurality of layers.

(Light diffusion layer)
The antireflection film of the present invention has a higher refractive index than the transparent protective film on the transparent protective film, a light diffusion layer corresponding to the high refractive index layer in the present invention, and a lower refractive index than the transparent protective film. The low-refractive-index layer may be composed of at least an antireflection layer that is sequentially laminated.

  The light diffusion layer is formed by dispersing at least one kind of translucent particles having an average particle diameter of 0.5 to 5 μm in a translucent resin, and the translucent particles and the translucent resin High refraction with no surface irregularities formed of a layer in which the difference in refractive index is 0.02 to 0.2 and the translucent particles are contained in 3 to 30% by mass in the total solid content of the light diffusion layer It is a rate layer. That is, the light-transmitting particles dispersed in the high refractive index layer do not have a size exceeding the thickness of the high refractive index layer, and are internally scattered in the layer to reduce reflection.

  The thickness of the light diffusion layer is usually about 0.5 μm to 50 μm, preferably 1 μm to 20 μm, and more preferably 2 μm to 10 μm. The refractive index of the translucent resin is preferably 1.51 to 2.00, more preferably 1.51 to 1.90, still more preferably 1.51 to 1.85, and particularly preferably. 1.51-1.80. In addition, the refractive index of translucent resin is the value measured without including translucent particle | grains.

  The difference in refractive index between the translucent particles and the translucent resin is usually about 0.02 to 0.20, and particularly preferably 0.04 to 0.10. If the difference is 0.20 or less, problems such as clouding of the film do not occur, and if it is 0.02 or more, an excellent light diffusion effect can be exhibited, which is preferable. The amount of translucent particles added to the translucent resin is as important as the refractive index. To maintain the transparency of the film and obtain an excellent light diffusion effect, the content of the translucent particles is light. It is preferable that it is 3-30 mass% in diffusion layer total solid content, and also 5-20 mass%.

  When the above-described light-transmitting particles are added, the light-transmitting particles easily settle in the light-transmitting resin, and therefore an inorganic filler such as silica may be added to prevent sedimentation. As the amount of the inorganic filler added increases, it is more effective in preventing the translucent particles from settling, but adversely affects the transparency of the light diffusion layer. Therefore, it is preferable that an inorganic filler having a particle size of 0.5 μm or less is contained in an amount of less than 0.1% by mass so as not to impair the transparency of the light diffusion layer with respect to the translucent resin.

  Further, the antireflection film having the light scattering layer of the present invention preferably has an average reflectance of 2.5% or less at a wavelength of 380 nm to 680 nm and a haze of 10 to 40%. More preferably, the average reflectance is 1.8% or less and the haze is 10 to 35%.

  By specifying the optical characteristics of the anti-reflection film within such a range, image sharpness without causing the screen to appear whitish or causing blurring of image display, contrast reduction and hue change due to changes in viewing angle, etc. The image display quality can be improved with sufficiently suppressed, no reflection of external light or glare on the screen, excellent antireflection properties, and the like.

  Specific examples of the light-transmitting particles, matrix, and other additives used in the light scattering layer of the present invention are the same as those described in the high refractive index layer and the antiglare layer. It is done.

[Other layers]
[Transparent antistatic layer]
In the present invention, a transparent antistatic layer containing a conductive material can be provided between the transparent protective film and the light diffusion layer. This is preferable because an antistatic effect on the surface of the antireflection film can be exhibited. Note that it is preferable to provide a conductive layer as a transparent antistatic layer in order to protect the polarizing plate on the viewing side provided in the display device in which the liquid crystal mode is the IPS mode or the VA mode from the outer surface energy.

  The method of forming the transparent antistatic layer is, for example, a method of applying a conductive antistatic layer coating solution containing conductive fine particles and a reactive curable resin, a method of forming a conductive polymer cured film, or a transparent A conventionally known method such as a method of forming a conductive thin film by vapor deposition or sputtering of a metal or metal oxide that forms a film can be exemplified. The transparent antistatic layer can be formed directly on the transparent protective film or via a primer layer that strengthens adhesion to the transparent protective film.

  A transparent antistatic layer can also be used as part of the antireflection film. In this case, when used in a layer close to the outermost layer, sufficient antistatic properties can be obtained even if the film is thin. The coating method is not particularly limited, and an optimum method is selected from known methods such as roll coating, gravure coating, bar coating, extrusion coating, etc., depending on the characteristics and coating amount of the coating solution for the antistatic layer. Just do it.

  As the transparent antistatic layer, a conventionally known antistatic layer can be appropriately adjusted and used. As the transparent antistatic layer, for example, edited by Toray Research Center Co., Ltd. “Current Status and Prospects of Transparent Conductive Films” [Toray Research Center Co., Ltd., published in 1997], Yutaka Toyoda “New Development of Transparent Conductive Films” "[CMC Co., Ltd., published in 1999]" and the like.

  The thickness of the transparent antistatic layer is preferably 0.01 to 10 μm, and more preferably 0.05 to 5 μm.

The surface resistance of the transparent antistatic layer is preferably 2 × 10 ¹² Ω / □ or less, more preferably 10 ⁵ to 10 ¹² Ω / □, and still more preferably 10 ⁵ to 10 ⁸ Ω / □. □. The surface resistance of the transparent antistatic layer can be measured by a four probe method.

  The transparent antistatic layer is preferably substantially transparent. Specifically, the haze of the transparent antistatic layer is preferably 10% or less, more preferably 3% or less, and most preferably 1% or less. The transmittance of light having a wavelength of 550 nm is preferably 50% or more, more preferably 60% or more, further preferably 65% or more, and most preferably 70% or more.

  Further, the transparent antistatic layer preferably has excellent surface strength, and the specific surface strength of the transparent antistatic layer is 2H or more with a pencil hardness of 1 kg (as defined in JIS-K-5400). Is preferable, and 3H or more is more preferable.

  The transparent antistatic layer is preferably a cured resin layer containing conductive inorganic fine particles.

(Conductive inorganic fine particles of transparent antistatic layer)
The specific surface area of the conductive inorganic fine particles is preferably from 10 to 400 m ² / g, more preferably from 30 to 150 m ² / g.

  Examples of conductive inorganic fine particles include “Current Status and Prospects of Transparent Conductive Films”, Chapters 3 to 4, edited by Technical Information Association “Development and Application of Conductive Fillers” (Technical Information Association, published in 1997), etc. And the inorganic compounds described. Specifically, for example, it is preferably formed from a metal oxide or nitride. Examples of metal oxides or nitrides include tin oxide, indium oxide, zinc oxide and titanium nitride. Tin oxide and indium oxide are particularly preferred.

  The conductive inorganic fine particles are mainly composed of oxides or nitrides of these metals, and can further contain other elements. The main component means a component having the largest content (mass%) among the components constituting the particles. Examples of other elements include Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P, S, B, Nb, In, V and a halogen atom are mentioned. In order to increase the conductivity of tin oxide and indium oxide, it is preferable to add Sb, P, B, Nb, In, V and a halogen atom. Particularly preferred are tin oxide containing Sb (ATO) and indium oxide containing Sn (ITO). The ratio of Sb in ATO is preferably 3 to 20% by mass. The ratio of Sn in ITO is preferably 5 to 20% by mass.

  The average primary particle diameter of the conductive inorganic fine particles used in the transparent antistatic layer is preferably 1 to 150 nm, more preferably 3 to 100 nm. The average particle diameter of the conductive inorganic fine particles in the formed transparent antistatic layer is 1 to 200 nm, and more preferably 10 to 80 nm. The average particle diameter of the conductive inorganic fine particles is an average diameter weighted by the mass of the particles and can be measured by a light scattering method or an electron micrograph.

  The conductive inorganic fine particles may be subjected to a surface treatment. The surface treatment is performed using an inorganic compound or an organic compound. Examples of inorganic compounds used for the surface treatment include alumina and silica. Silica treatment is particularly preferred. Examples of the organic compound used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Silane coupling agents are most preferred. Two or more types of surface treatments may be combined.

  The shape of the conductive inorganic fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape or an indefinite shape. Two or more kinds of conductive inorganic fine particles may be used in combination in the antistatic layer.

  The proportion of the conductive inorganic fine particles in the transparent antistatic layer is preferably 20 to 90% by mass, preferably 25 to 85% by mass, and more preferably 30 to 80% by mass.

(Binder for transparent antistatic layer)
In the transparent antistatic layer, a crosslinked polymer, that is, a cured resin can be used as a binder. The crosslinked polymer preferably has an anionic group. In the polymer having a crosslinked anionic group, the main chain of the polymer having an anionic group preferably has a crosslinked structure. The anionic group has a function of maintaining the dispersion state of the conductive inorganic fine particles. The crosslinked structure has a function of strengthening the transparent antistatic layer by imparting a film forming ability to the polymer.

  Examples of the polymer main chain include polyolefin (saturated hydrocarbon), polyether, polyurea, polyurethane, polyester, polyamine, polyamide and melamine resin. A polyolefin main chain, a polyether main chain and a polyurea main chain are preferable, a polyolefin main chain and a polyether main chain are more preferable, and a polyolefin main chain is most preferable.

  The polyolefin main chain is composed of a saturated hydrocarbon, and is obtained, for example, by an addition polymerization reaction of an unsaturated polymerizable group. The polyether main chain has repeating units bonded by an ether bond (—O—), and is obtained, for example, by a ring-opening polymerization reaction of an epoxy group. The polyurea main chain has repeating units bonded by a urea bond (—NH—CO—NH—), and is obtained, for example, by a polycondensation reaction between an isocyanate group and an amino group. The polyurethane main chain has repeating units bonded by urethane bonds (—NH—CO—O—), and is obtained, for example, by a polycondensation reaction between an isocyanate group and a hydroxyl group (including an N-methylol group). The polyester main chain has repeating units bonded by an ester bond (—CO—O—). For example, a polycondensation reaction between a carboxyl group (including an acid halide group) and a hydroxyl group (including an N-methylol group). Is obtained. The polyamine main chain has repeating units bonded by imino bonds (—NH—), and is obtained, for example, by a ring-opening polymerization reaction of an ethyleneimine group. The polyamide main chain has repeating units bonded by an amide bond (—NH—CO—), and is obtained, for example, by a reaction between an isocyanate group and a carboxyl group (including an acid halide group). The melamine resin has a crosslinked structure in the main chain itself, and is obtained, for example, by a polycondensation reaction between a triazine group (eg, melamine) and an aldehyde (eg, formaldehyde).

  The anionic group may be directly bonded to the main chain of the polymer or may be bonded to the main chain via a linking group. The anionic group is preferably bonded to the main chain as a side chain via a linking group.

  Examples of the anionic group include a carboxylic acid group (carboxyl group), a sulfonic acid group (sulfo group), a phosphoric acid group (phosphono group), and the like, and a sulfonic acid group and a phosphoric acid group are preferable.

  The anionic group may be in a salt state. The cation that forms a salt with the anionic group is preferably an alkali metal ion. Moreover, the proton of the anionic group may be dissociated.

  The linking group that binds the anionic group and the polymer main chain is preferably a divalent group selected from —CO—, —O—, an alkylene group, an arylene group, and combinations thereof.

  The crosslinked structure is a structure in which two or more main chains are chemically bonded (preferably a covalent bond), and among them, it is preferable to covalently bond three or more main chains. The crosslinked structure is preferably composed of a divalent or higher valent group selected from —CO—, —O—, —S—, a nitrogen atom, a phosphorus atom, an aliphatic residue, an aromatic residue, and combinations thereof.

  The crosslinked polymer having an anionic group is preferably a copolymer having a repeating unit having an anionic group and a repeating unit having a crosslinked structure. The proportion of the repeating unit having an anionic group in the copolymer is preferably 2 to 96% by mass, more preferably 4 to 94% by mass, and most preferably 6 to 92% by mass. The repeating unit may have two or more types of anionic groups. The proportion of the repeating unit having a crosslinked structure in the copolymer is preferably 4 to 98% by mass, more preferably 6 to 96% by mass, and most preferably 8 to 94% by mass.

  The repeating unit of the crosslinked polymer having an anionic group may have both an anionic group and a crosslinked structure. Further, other repeating units (repeating units having neither an anionic group nor a crosslinked structure) may be contained.

  Other repeating units are preferably a repeating unit having an amino group or a quaternary ammonium group and a repeating unit having a benzene ring. An amino group or a quaternary ammonium group is preferable because it has a function of maintaining the dispersed state of inorganic fine particles, like an anionic group. The amino group, the quaternary ammonium group, and the benzene ring can obtain the same effect even if they are contained in the repeating unit having an anionic group or the repeating unit having a crosslinked structure.

  The repeating unit having an amino group or a quaternary ammonium group can be obtained by bonding an amino group or a quaternary ammonium group directly to the main chain of the polymer or by connecting to the main chain via a linking group. The amino group or quaternary ammonium group is preferably bonded to the main chain as a side chain via a linking group. The amino group or quaternary ammonium group is preferably a secondary amino group, a tertiary amino group or a quaternary ammonium group, more preferably a tertiary amino group or a quaternary ammonium group. The group bonded to the nitrogen atom of the secondary amino group, tertiary amino group or quaternary ammonium group is preferably an alkyl group, and preferably an alkyl group having 1 to 12 carbon atoms. The counter ion of the quaternary ammonium group is preferably a halide ion. The linking group that connects the amino group or quaternary ammonium group to the polymer main chain is a divalent group selected from -CO-, -NH-, -O-, an alkylene group, an arylene group, and combinations thereof. Preferably there is. When the crosslinked polymer having an anionic group contains a repeating unit having an amino group or a quaternary ammonium group, the ratio is preferably 0.06 to 32% by mass, and 0.08 to 30% by mass. More preferably, it is most preferable that it is 0.1-28 mass%.

  For these binders, for example, reactive organic silicon compounds (1) to (3) described in JP-A No. 2003-39586 can be used in combination. The reactive organosilicon compound is used in the range of 10 to 100% by mass based on the total amount of the binder and the reactive organosilicon compound.

  The laminated antireflection film may further be provided with a moisture proof layer, an antistatic layer (conductive layer), a primer layer, an undercoat layer, a protective layer, a shield layer, and a sliding layer. The shield layer is provided to shield electromagnetic waves and infrared rays.

<Transparent protective film>
As described above, the antireflection film is coated on the transparent protective film in the polarizing plate of the present invention. Examples of transparent protective film materials include cellulose esters (eg, triacetylcellulose, diacetylcellulose, propionylcellulose, butyrylcellulose, acetylpropionylcellulose, nitrocellulose), polyamides, polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene naphthalate, Poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4,4′-dicarboxylate, polybutylene terephthalate), polystyrene (eg, syndiotactic polystyrene), polyolefin (eg, polypropylene, polyethylene) , Polymethylpentene, polycycloalkane), polysulfone, polyethersulfone, polyarylate, polyether Terimide, polymethyl methacrylate, polyether ketone and the like are included. Triacetyl cellulose, polycarbonate, polyethylene terephthalate and polyethylene naphthalate are preferred.

  The light transmittance of the transparent protective film is preferably 80% or more, and more preferably 86% or more. The haze of the transparent protective film is preferably 2.0% or less, and more preferably 1.0% or less. The refractive index of the transparent protective film is preferably 1.4 to 1.7.

  The polarizing plate with an antireflection film of the present invention is prepared by coating the antireflection film described above on the transparent protective film, and applying a polarizing film to be described later on the opposite surface of the transparent protective film with an adhesive. A mode of using and laminating is preferable. As a result, the thickness of the entire polarizing plate can be reduced, and the weight of the image display device provided with the polarizing plate can be reduced.

  As a preferred transparent protective film for use in such a polarizing plate, the hydrophobic / hydrophilic balance of the film, the bonding property of the polarizing film with the vinyl alcohol film, and the uniformity of the optical properties throughout the film plane are important. Especially preferred is a cellulose acylate film. In particular, a cellulose fatty acid ester (cellulose acylate) film is preferable, and a film containing cellulose acylate, a plasticizer, and fine particles is more preferable.

[Cellulose acylate film]
Cellulose as a raw material for cellulose acylate film used as a transparent protective film includes cotton linter, kenaf, wood pulp (hardwood pulp, softwood pulp), etc., and any cellulose ester obtained from any raw material cellulose can be used. You may mix and use.

  In the present invention, cellulose acylate is produced by esterification from cellulose. However, particularly preferred cellulose as described above cannot be used as it is, and linter, kenaf and pulp are purified and used.

  In the present invention, cellulose acylate is a carboxylic acid ester having 2 to 22 carbon atoms in total.

  The acyl group having 2 to 22 carbon atoms of the cellulose acylate used in the present invention may be an aliphatic acyl group or an aromatic acyl group, and is not particularly limited. They are, for example, alkyl carbonyl esters, alkenyl carbonyl esters, cycloalkyl carbonyl esters, aromatic carbonyl esters, aromatic alkyl carbonyl esters, and the like of cellulose, each of which may further have a substituted group. Examples of these preferred acyl groups include acetyl, propionyl, butanoyl, heptanoyl, hexanoyl, octanoyl, cyclohexanecarbonyl, adamantanecarbonyl, phenylacetyl, benzoyl, naphthylcarbonyl, and cinnamoyl groups. Among these, more preferred acyl groups are propionyl, butanoyl, pentanoyl, hexanoyl, cyclohexanecarbonyl, phenylacetyl, benzoyl, naphthylcarbonyl, and the like.

  The method for synthesizing cellulose acylate is described in detail on page 9 of the Japan Society for Invention and Innovation, published technical bulletin No. 2001-1745 (Invention Association on March 15, 2001).

The cellulose acylate preferably used in the present invention preferably has a degree of substitution with a hydroxyl group of cellulose satisfying the following mathematical formulas (7) and (8).
Formula (7): 2.3 ≦ SA ′ + SB ′ ≦ 3.0
Formula (8): 0 ≦ SA ′ ≦ 3.0

  Here, SA ′ is the substitution degree of the acetyl group substituting the hydrogen atom of the hydroxyl group of cellulose, and SB ′ is the substitution degree of the acyl group having 3 to 22 carbon atoms substituting the hydrogen atom of the hydroxyl group of cellulose. Represents. SA represents an acetyl group substituting a hydrogen atom of a hydroxyl group of cellulose, and SB represents an acyl group having 3 to 22 carbon atoms substituting a hydrogen atom of a hydroxyl group of cellulose.

  Glucose units having β-1,4 bonds constituting cellulose have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer obtained by esterifying some or all of these hydroxyl groups with acyl groups. The degree of acyl substitution means the proportion of cellulose esterified at each of the 2-position, 3-position and 6-position (100% esterification at each position is substitution degree 1). In the present invention, the total sum of substitution degrees of SA and SB (SA ′ + SB ′) is more preferably 2.6 to 3.0, and particularly preferably 2.80 to 3.00. Further, the substitution degree (SA ′) of SA is more preferably 1.4 to 3.0, and particularly 2.3 to 2.9.

Furthermore, it is preferable that the following numerical formula (9) is satisfied at the same time.
Formula (9): 0 ≦ SB ”≦ 1.2
Here, SB ″ represents an acyl group having 3 or 4 carbon atoms replacing a hydrogen atom of a hydroxyl group of cellulose.

  Further, SB ″ is preferably 28% or more of the substituent at the 6-position hydroxyl group, more preferably 30% or more is the substituent at the 6-position hydroxyl group, more preferably 31% or more, and particularly preferably 32% or more. It is also preferred that the substituent is a hydroxyl group at the 6-position. Furthermore, the sum of the substitution degrees of SA ′ and SB ″ at the 6-position of the cellulose acylate is 0.8 or more, more preferably 0.85 or more, A cellulose acylate film having a value of 0.90 or more can also be mentioned as a preferable example. These cellulose acylate films can produce a solution having a preferable solubility, and in particular, a non-chlorine organic solvent can produce a good solution.

The degree of substitution can be obtained by calculating the degree of binding of the fatty acid bound to the hydroxyl group in cellulose. As a measuring method, it can measure based on ASTM-D817-91 and ASTM-D817-96. The state of substitution of the acyl group with the hydroxyl group is measured by ¹³ C NMR method.

  The cellulose acylate film is preferably made of a cellulose acylate in which the polymer component constituting the film substantially satisfies the above mathematical formulas (7) and (8). “Substantially” means 55% by mass or more (preferably 70% by mass or more, more preferably 80% by mass or more) of the total polymer components. The cellulose acylate may be used alone or in combination of two or more.

  The degree of polymerization of the cellulose acylate preferably used in the present invention is a viscosity average degree of polymerization of 200 to 700, preferably 230 to 550, more preferably 230 to 350, and particularly preferably a viscosity average degree of polymerization of 240 to 320. The average degree of polymerization can be measured by Uda et al.'S intrinsic viscosity method (Kazuo Uda, Hideo Saito, Journal of Textile Society, Vol. 18, No. 1, pages 105-120, 1962). Further details are described in JP-A-9-95538.

The number average molecular weight Mn of the cellulose acylate is preferably in the range of 7 to 25 × 10 ⁴ , more preferably in the range of 8 to 15 × 10 ⁴ . The ratio of the cellulose acylate to the mass average molecular weight Mw, Mw / Mn, is preferably 1.0 to 5.0, more preferably 1.0 to 3.0. In addition, the average molecular weight and molecular weight distribution of a cellulose ester can be measured using high performance liquid chromatography, Mn and Mw can be calculated using this, and Mw / Mn can be calculated.

The cellulose acylate film used in the present invention has a cellulose acylate and a plasticizer in a range satisfying the above mathematical formulas (7) and (8) [particularly preferably an octanol / water partition coefficient (log P value) described later]. 0 to 10 plasticizers] and a film containing at least one kind of fine particles (particularly preferably, fine particles having an average primary particle size of 3 to 100 nm described later) are preferably used.
Next, the plasticizer and fine particles will be described.

[Plasticizer]
The plasticizer that can be suitably used in the present invention is a component added to impart flexibility to the cellulose acylate film, improve dimensional stability, and improve moisture resistance. The preferred plasticizer is preferably a solid having a boiling point of 200 ° C. or higher and a liquid at 25 ° C. or a melting point of 25 to 250 ° C. More preferred are plasticizers having a boiling point of 250 ° C. or higher and a liquid at 25 ° C. or a solid having a melting point of 25 to 200 ° C. When the plasticizer is a liquid, the purification is usually carried out by distillation under reduced pressure, and a higher vacuum is preferable. In the present invention, it is particularly preferable to use a plasticizer having a vapor pressure at 200 ° C. of 1333 Pa or less, more preferably steam. A compound having a pressure of 667 Pa or less, more preferably 133 to 1 Pa is preferred.

  As these plasticizers that are preferably added, phosphate esters, carboxylic acid esters, polyol esters and the like within the above-mentioned physical properties are used. Examples of phosphate esters include triphenyl phosphate (TPP) and tricresyl phosphate (TCP), cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, and the like.

  Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of the phthalic acid ester include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP), and diethylhexyl phthalate (DEHP). Examples of citrate esters include O-acetyl triethyl citrate (OACTE) and O-acetyl tributyl citrate (OACTB), acetyl triethyl citrate, acetyl tributyl citrate and the like. These preferred plasticizers are liquid except for TPP (melting point: about 50 ° C.) at 25 ° C., and the boiling point is 250 ° C. or higher.

  Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Examples of glycolic acid esters include triacetin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, methyl phthalyl methyl glycolate, propyl phthalyl Examples include propyl glycolate, butyl phthalyl butyl glycolate, and octyl phthalyl octyl glycolate.

  JP-A-5-194788, JP-A-60-250053, JP-A-4-227941, JP-A-6-16869, JP-A-5-271471, JP-A-7-286068, JP-A-5-5047. No. 11, JP-A-11-80381, JP-A-7-20317, JP-A-8-57879, JP-A-10-152568, JP-A-10-120824, etc. are also preferably used. It is done. According to these publications, there are many preferable descriptions not only on the plasticizer but also on its utilization method or its characteristics, and it is preferably used in the present invention.

  Examples of other plasticizers include (di) pentaerythritol esters described in JP-A-11-124445, glycerol esters described in JP-A-11-246704, diglycerol esters described in JP-A-2000-63560, Citric acid esters described in JP-A No. 11-92574, substituted phenyl phosphate esters described in JP-A No. 11-90946, ester compounds containing an aromatic ring and a cyclohexane ring described in JP-A No. 2003-165868 are preferably used. .

  Furthermore, in the present invention, a plasticizer having an octanol / water partition coefficient (log P value) of 0 to 10 is particularly preferably used. If the log P value of the compound is 10 or less, the compatibility with the cellulose acylate is good, there is no problem such as cloudiness or powder blowing of the film, and if the log P value is greater than 0, the hydrophilicity is high. Since it does not become too high, adverse effects such as deterioration of the water resistance of the cellulose acylate film are unlikely to occur. As the logP value, a more preferable range is 1 to 8, and a particularly preferable range is 2 to 7.

  The octanol / water partition coefficient (log P value) can be measured by a flask immersion method described in JIS Japanese Industrial Standard Z7260-107 (2000). Further, the octanol / water partition coefficient (log P value) can be estimated by a computational chemical method or an empirical method instead of the actual measurement. As a calculation method, Crippen's fragmentation method [J. Chem. Inf. Comput. Sci. 27, 21 (1987)], Viswanadhan's fragmentation method [J. Chem. Inf. Comput. Sci. , 29, 163 (1989)], Broto's fragmentation method [Eur. J. et al. Med. Chem. -Chim. Theor. 19 (71) (1984)] is preferably used, and the Crippen's fragmentation method is more preferable. When the log P value of a certain compound varies depending on the measurement method or calculation method, it is preferable to determine whether or not the compound is within the scope of the present invention by the Crippen's fragmentation method.

  A polymer plasticizer having a resin component having a molecular weight of 1,000 to 100,000 is also preferably used. For example, polyesters and / or polyethers described in JP-A No. 2002-22956, polyester ethers, polyester urethanes or polyesters described in JP-A No. 5-97073, copolyester ethers described in JP-A No. 2-292342, Examples thereof include an epoxy resin or a novolac resin described in JP-A No. 2002-146044.

  These plasticizers may be used alone or in combination of two or more. The addition amount of the plasticizer is preferably 2 to 30 parts by mass, particularly 5 to 20 parts by mass with respect to 100 parts by mass of the cellulose acylate.

[Fine particles]
The fine particles preferably used in the cellulose acylate film for forming the transparent protective film are added to improve the mechanical strength and dimensional stability of the film and improve the moisture resistance, and are hydrophobic. preferable.

  The primary average particle size of the fine particles is preferably 1 to 100 nm, more preferably 3 to 100 nm, still more preferably 3 to 80 nm, and particularly preferably 5 to 100 nm, from the viewpoint of keeping haze low. 60 nm, most preferably 5-50 nm. The primary average particle diameter of the fine particles can be measured by measuring the particles with a transmission electron microscope and determining the average particle diameter.

  The apparent specific gravity of the fine particles is preferably 70 g / liter or more, more preferably 90 to 200 g / liter, and particularly preferably 100 to 200 g / liter.

  The addition amount of the fine particles is preferably 0.005 to 2 parts by mass, particularly 0.01 to 1.0 part by mass with respect to 100 parts by mass of the cellulose acylate.

  Preferred specific examples of the fine particles include inorganic compounds such as silicon-containing compounds, silicon dioxide, titanium oxide, zinc oxide, aluminum oxide, barium oxide, zirconium oxide, strontium oxide, antimony oxide, tin oxide, tin oxide / antimony carbonate, Calcium, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate are preferred, more preferably silicon-containing inorganic compounds and zirconium oxide, cellulose acylate Since the haze increase of the film can be suppressed, silicon dioxide is particularly preferably used.

  The fine particles suitably used for the cellulose acylate film in the present invention are surface-treated for the reason that aggregation in the film after dope and after film formation is suppressed and the fine particles are stably dispersed as fine particles. Is preferred. The surface treatment is performed by treating the surface of fine particles with an organic compound. Examples of organic compounds that can be used in this case include surface modification of conventionally known inorganic fillers such as metal oxides and inorganic pigments. Examples are described in, for example, “Pigment Dispersion Stabilization and Surface Treatment Technology / Evaluation”, Chapter 1 (Technical Information Association, 2001). Specifically, an organic compound having a polar group having an affinity for the fine particle surface and a coupling compound can be mentioned.

  Examples of the polar group having an affinity for the fine particle surface include a carboxy group, a phosphono group, a hydroxy group, a mercapto group, a cyclic acid anhydride group, an amino group, and the like, and a compound containing at least one kind in the molecule is preferable. For example, long-chain aliphatic carboxylic acids (eg stearic acid, lauric acid, oleic acid, linoleic acid, linolenic acid, etc.), polyol compounds (eg pentaerythritol triacrylate, dipentaerythritol pentaacrylate, ECH-modified glycerol, etc.), phosphono groups Examples thereof include compounds [for example, EO (ethylene oxide) -modified phosphoric acid, etc.], alkanolamines [ethylene diamine adduct (5 mol), etc.].

As a coupling compound, a conventionally well-known organometallic compound is mentioned, A silane coupling agent, a titanate coupling agent, an aluminate coupling agent etc. are contained. Silane coupling agents are most preferred. Specific examples include coupling compounds described by Fuzo Yamashita and Tosuke Kaneko “Crosslinking Agent Handbook” (Taiseisha, published in 1981).
In the surface treatment, two or more kinds of the above-mentioned compounds can be used in combination.

  As the organic compound, for example, polymers such as a silicone resin, a fluorine resin, and an acrylic resin are preferable, and among these, a silicone resin is preferably used. Of the silicone resins, those having a three-dimensional network structure are particularly preferable. A commercial product having a trade name can be used.

  The shape of the fine particles used in the present invention is not particularly limited, but is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape, or an indefinite shape. The fine particles may be used alone or in combination of two or more.

  The fine particles preferably used in the present invention are preferably uniformly dispersed in the film after film formation. Therefore, the fine particles are preferably introduced into the dope solution after preparing a fine particle dispersion in the following manner or the like.

(1) After stirring and mixing the solvent and the fine particles, a fine particle dispersion is prepared with a disperser, and added to the dope solution and stirred.
(2) After stirring and mixing the solvent and the fine particles, the dispersion is made into a fine particle dispersion, and a small amount of cellulose acylate is added to the solvent and dissolved by stirring. The fine particle dispersion obtained by adding the fine particle dispersion to this and stirring is sufficiently mixed with the dope solution using an in-line mixer.
(3) A small amount of cellulose acylate is added to a solvent and dissolved by stirring. Fine particles are added to the solvent and dispersed with a disperser to obtain a fine particle addition solution. The fine particle additive solution is sufficiently mixed with the dope solution using an in-line mixer.

  The mass average diameter of the primary particles of the fine particles in the dispersion is preferably 3 to 200 nm, more preferably 3 to 150 nm, still more preferably 3 to 100 nm, and particularly preferably 5 to 80 nm. In particular, it is preferable that the dispersed fine particles in the wet dispersion in the present invention substantially maintain the fine particles to have a primary particle size or larger so as not to excessively increase the specific surface area of the fine particles during dispersion. Furthermore, the dispersed fine particles in the wet dispersion preferably do not contain large particles having an average particle diameter of 500 nm or more, and particularly preferably do not contain large particles having an average particle diameter of 300 nm or more. Furthermore, it is preferable that large particles having an average particle diameter of 500 nm or more are not included, and it is particularly preferable that large particles having an average particle diameter of 300 nm or more are not included. By this, it is a film with no transparency and a good transparency with a small haze value, and a specific uneven shape whose surface is described later can be formed.

[Ultraviolet light prevention agent]
In order to improve the light resistance of the film itself or to prevent deterioration of image display members such as a polarizing plate and a liquid crystal compound of a liquid crystal display device, it is preferable to add an ultraviolet ray inhibitor to the cellulose acylate film.

  As the ultraviolet absorber, one having an excellent ability to absorb ultraviolet rays having a wavelength of 370 nm or less from the viewpoint of preventing deterioration of the liquid crystal and having as little absorption of visible light having a wavelength of 400 nm or more as possible from the viewpoint of good image display properties is used. It is preferable. In particular, the transmittance at a wavelength of 370 nm is desirably 20% or less, preferably 10% or less, and more preferably 5% or less. Examples of such ultraviolet absorbers include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and ultraviolet absorbing groups as described above. Examples thereof include, but are not limited to, polymer ultraviolet absorbing compounds. Two or more kinds of ultraviolet absorbers may be used.

  As a method of adding the ultraviolet absorber to the dope, it may be added after being dissolved in an organic solvent such as alcohol, methylene chloride, dioxolane, or may be added directly into the dope composition. For an inorganic powder that does not dissolve in an organic solvent, a dissolver or a sand mill is used in the organic solvent and cellulose ester to disperse and then added to the dope.

  In this invention, the usage-amount of a ultraviolet absorber is 0.1-5.0 mass parts with respect to 100 mass parts of cellulose acylates, Preferably it is 0.5-2.0 mass parts, More preferably, it is 0.8-2. 0 parts by mass.

[Other additives]
Furthermore, in the cellulose acylate composition of the present invention, other various additives (for example, deterioration inhibitors (for example, antioxidants, peroxide decomposition agents, radical inhibitors, Metal deactivators, acid scavengers, amines, etc.), optical anisotropy control agents, release agents, antistatic agents, infrared absorbers, etc.) may be added, and these may be solid or oily. That is, the melting point and boiling point are not particularly limited. Furthermore, as an infrared absorber, the thing as described in Unexamined-Japanese-Patent No. 2001-194522 can be used, for example.

  These additives may be added at any time in the dope preparation step, but may be added in the final preparation step of the dope preparation step by adding a preparation step. Furthermore, the amount of each material added is not particularly limited as long as the function is manifested. Moreover, when a cellulose acylate film is formed from a multilayer, the kind and addition amount of the additive of each layer may differ. For example, it is described in Japanese Patent Application Laid-Open No. 2001-151902 and the like, but these are conventionally known techniques. Details of these, including the above-mentioned ultraviolet absorbers, are disclosed in JIII Journal of Technical Disclosure No. 2001-1745 (issued March 15, 2001, Invention Association) p. The materials described in detail in 16-22 are preferably used.

  The amount of these additives used is preferably used in the range of 0.001 to 20% by mass in the entire cellulose acylate composition.

(solvent)
Next, the organic solvent that dissolves the cellulose acylate of the present invention will be described. Examples of the organic solvent to be used include conventionally known organic solvents. For example, those having a solubility parameter in the range of 17 to 22 are preferable. Lower aliphatic hydrocarbon chloride, lower aliphatic alcohol, ketone having 3 to 12 carbon atoms, ester having 3 to 12 carbon atoms, ether having 3 to 12 carbon atoms, fat having 5 to 8 carbon atoms Group hydrocarbons, aromatic hydrocarbons having 6 to 12 carbon atoms, fluoroalcohols (for example, described in paragraph No. [0020] of JP-A-8-143709, paragraph No. [0037] of JP-A-11-60807) Compound) and the like.

  The cellulose acylate of the present invention is preferably a solution in which 10 to 30% by mass is dissolved in an organic solvent, more preferably 13 to 27% by mass, and particularly 15 to 25% by mass. A cellulose acylate solution is preferred. The method for preparing cellulose acylate at these concentrations may be prepared so as to be a predetermined concentration at the stage of dissolution, or it is prepared in advance as a low concentration solution (for example, 9 to 14% by mass) and then concentrated later. You may adjust to a predetermined high concentration solution by a process. Furthermore, a cellulose acylate solution having a high concentration may be added to the cellulose acylate solution at a predetermined low concentration by adding various additives, and the cellulose acylate solution concentration of the present invention is obtained by any method. If implemented, there is no particular problem.

[Preparation of dope]
Regarding the preparation of the cellulose acylate solution (dope) of the present invention, the dissolution method is not particularly limited as described above, and it is carried out by a room temperature dissolution method, a cooling dissolution method or a high temperature dissolution method. Implemented in combination. With respect to these, for example, JP-A-5-163301, JP-A-61-106628, JP-A-58-127737, JP-A-9-95544, JP-A-10-95854, JP-A-10-45950, JP 2000-53784, JP 11-322946, JP 11-322947, JP 2-276830, JP 2000-273239, JP 11-71463, JP 04-259511, JP JP-A Nos. 2000-273184, 11-323017 and 11-302388 describe methods for preparing a cellulose acylate solution. These techniques for dissolving cellulose acylate in an organic solvent can be applied as appropriate within the scope of the present invention. About these details, especially a non-chlorine type | system | group solvent system, it implements by the method described in detail on the 22-25th pages of the above-mentioned technical numbers 2001-1745. Further, the cellulose acylate dope solution of the present invention is usually subjected to solution concentration and filtration, and is also described in detail on page 25 of the above-mentioned official technical number 2001-1745. In addition, when it melt | dissolves at high temperature, it is the case where it is more than the boiling point of the organic solvent to be used, and in that case, it uses in a pressurized state.

The cellulose acylate solution of the present invention preferably has a viscosity and a dynamic storage elastic modulus within a specific range. 1 mL of the sample solution was used in a rheometer (CLS 500) with a Steel Cone (both manufactured by TA Instruments) with a diameter of 4 cm / 2 °, and the measurement conditions were Oscillation Step / Temperature Ramp in the range of 40 ° C. to −10 ° C. at 2 ° C. / Measured by varying the minute, the static non-Newtonian viscosity n ^* (Pa · sec) at 40 ° C. and the storage elastic modulus G ′ (Pa) at 5 ° C. are determined. The sample solution is kept warm until the liquid temperature becomes constant at the measurement start temperature, and then the measurement is started. In the present invention, the viscosity at 40 ° C. is preferably 1 to 300 Pa · sec, and the dynamic storage elastic modulus at −5 ° C. is preferably 10,000 to 1,000,000 Pa. More preferably, the viscosity at 40 ° C. is 1 to 200 Pa · sec, and the dynamic storage elastic modulus at −5 ° C. is 30,000 to 500,000 Pa.

[Method for producing cellulose acylate film]
Next, a method for producing a cellulose acylate film as a transparent protective film using the cellulose acylate solution will be described. As the method and equipment for producing the cellulose acylate film, a conventionally known solution casting film forming method and solution casting film forming apparatus called a drum method or a band method used for producing a cellulose triacetate film are used.

  The metal support used in the casting step preferably has a surface having an arithmetic average roughness (Ra) of 0.015 μm or less and a ten-point average roughness (Rz) of 0.05 μm or less. More preferably, the arithmetic average roughness (Ra) is 0.001 to 0.01 μm, and the ten-point average roughness (Rz) is 0.001 to 0.02 μm. More preferably, the (Ra) / (Rz) ratio is 0.15 or more. Thus, the surface shape of the film after film formation can be controlled within a preferable range described later by setting the surface roughness of the metal support within a predetermined range.

Hereinafter, the film forming process will be described by taking the band method as an example.
The dope (cellulose acylate solution) prepared from the dissolving machine (kettle) is temporarily stored in a storage kettle, and the foam contained in the dope is defoamed for final preparation. The dope is sent from the dope discharge port to the pressure die through a pressure metering gear pump capable of delivering a constant amount of liquid with high accuracy, for example, by the number of rotations, and the dope is run endlessly from the die (slit) of the pressure die. The dry-dried dope film (also referred to as web) is peeled off from the metal support at a peeling point that is uniformly cast on the metal support and substantially rounds the metal support. Both ends of the obtained web are sandwiched between clips, transported by a tenter while keeping the width, dried, then transported by a roll group of a drying device, dried, and wound up to a predetermined length by a winder. The combination of the tenter and the roll group dryer varies depending on the purpose. Each of these manufacturing processes is described in detail in the above-mentioned official technical numbers 2001-1745, pages 25-30, and is classified into casting (including co-casting), metal support, drying, peeling, stretching, etc. The

  In the casting step, one type of cellulose acylate solution may be cast as a single layer, or two or more types of cellulose acylate solutions may be cast simultaneously and / or sequentially.

[Characteristics of cellulose acylate film]
The cellulose acylate film which is a transparent protective film for a polarizing film provided for the present invention and is suitably used as a transparent protective film as a support for an antireflection film has the following characteristics.

(Film surface properties)
The cellulose acylate film used as the transparent protective film preferably has a specific surface shape. Hereinafter, the surface shape of the cellulose acylate film will be described.

  The surface of the cellulose acylate film on which the antireflection film is provided has an arithmetic average roughness (Ra) of the surface irregularity of the film based on JIS B-0601-1994 of 0.0001 to 0.1 μm, a ten-point average roughness. (Rz) is preferably 0.0001 to 0.3 [mu] m and maximum height (Ry) is preferably 0.5 [mu] m or less, arithmetic average roughness (Ra) is 0.0001 to 0.08 [mu] m, ten-point average roughness More preferably, the thickness (Rz) is 0.0001 to 0.1 μm, and the maximum height (Ry) is 0.5 μm or less, and the arithmetic average roughness (Ra) is 0.0002 to 0.015 μm, ten points. More preferably, the average roughness (Rz) is 0.002 to 0.05 μm and the maximum height (Ry) is 0.05 μm or less, and the arithmetic average roughness (Ra) is 0.001 to 0.010 μm, Ten-point average roughness (Rz ) Is 0.002 to 0.025 μm, and the maximum height (Ry) is particularly preferably 0.04 μm or less. Within these ranges, there is a uniform coating surface with no coating unevenness, an antireflection film with good adhesion between the transparent protective film and the coating film is provided, and the polarizing film is bonded to the polarizing film as a transparent protective film In this case, the adhesion becomes good.

  The concave and convex shapes on the surface can be evaluated by a transmission electron microscope (TEM), an atomic force microscope (AFM), or the like.

In addition, the number of optical defects having a visual size of 100 μm or more in the cellulose acylate film is preferably 1 or less per 1 m ² , from the viewpoint that a uniform and clear film can be obtained with high yield. . This optical defect can be observed using a polarizing microscope with the slow axis of the film parallel to the absorption axis of the polarizing film under crossed Nicols. The defects that appear as bright spots are approximated in a circular area, and those having a diameter of 100 μm or more are counted. Bright spots of 100 μm or more can be easily observed with the naked eye.

That is, the surface of the cellulose acylate film has an arithmetic average roughness (Ra) of surface irregularities based on JIS B-0601-1994 of 0.0001 to 0.1 μm, and a ten-point average roughness (Rz) of 0. It is preferable that the number of optical defects having a size of 0.0001 to 0.3 μm and a visual size of 100 μm or more is 1 or less per 1 m ² . By using the film having the above-described surface shape, non-uniformity of the display image such as optical defects and unevenness in brightness is remarkably reduced.

(Mechanical properties of film)
(Mechanical properties of film)
The curl value in the width direction of the transparent protective film used in the present invention is preferably -7 / m to + 7 / m. When performing on a long and wide transparent protective film (specifically, a long product having a length of 100 to 5000 m and a width of 0.7 to 150 m), the curl value in the width direction of the transparent protective film is within the aforementioned range. If it is inside, there will be no hindrance to handling of the film or cutting of the film. Also, at the edge or the center of the film, the film will come into strong contact with the transport roll, or dust may be generated on the film. It is preferable that the foreign matter adheres less and the frequency of point defects and coating stripes of the polarizing plate of the present invention does not exceed an allowable value. Further, it is preferable because bubbles can be prevented from entering when the polarizing film is bonded.

  The curl value can be measured according to a measurement method (ANSI / ASCPH1.29-1985) defined by the American National Standards Institute.

  The residual solvent amount of the transparent protective film used in the present invention is preferably 1.5% by mass or less because curling can be suppressed. Furthermore, it is more preferable that it is 0.01-1.0 mass% or less. This is presumably because free deposition is reduced by reducing the amount of residual solvent during film formation by the above-described solution casting film forming method.

  The tear strength of the cellulose acylate film is 2 g or more based on the tear test method (Elmendorf tear method) of JIS K-7128-2: 1998. It is preferable at the point which can fully hold | maintain. More preferably, it is 5-25g, More preferably, it is 6-25g. Further, in terms of 60 μm, 8 g or more is preferable, and more preferably 8 to 15 g. Specifically, it can be measured using a light load tear strength tester after conditioning a sample piece of 50 mm × 64 mm under the conditions of 25 ° C. and 65% RH for 2 hours.

  The scratch strength is preferably 2 g or more, more preferably 5 g or more, and particularly preferably 10 g or more. By setting it as this range, the scratch resistance and handling property of the film surface can be maintained without any problem. The scratch strength can be evaluated with a load (g) by which the surface of the transparent protective film is scratched using a sapphire needle having a cone apex angle of 90 ° and a tip radius of 0.25 m, and the scratch mark can be visually confirmed.

(Hygroscopic expansion coefficient of film)
It is preferable that the hygroscopic expansion coefficient of the cellulose acylate film is 30 × 10 ⁻⁵ /% RH or less. The hygroscopic expansion coefficient is more preferably 15 × 10 ⁻⁵ /% RH or less, and further preferably 10 × 10 ⁻⁵ /% RH or less. Further, the hygroscopic expansion coefficient is preferably small, but usually a value of 1.0 × 10 ⁻⁵ /% RH or more. The hygroscopic expansion coefficient indicates the amount of change in the length of the sample when the relative humidity is changed at a constant temperature. By adjusting the hygroscopic expansion coefficient, the durability of the polarizing plate transparent protective film is improved, or in the case of a polarizing plate laminated with an optical compensation film, the frame-shaped transmittance increases while maintaining the optical compensation function, that is, Light leakage due to distortion can be prevented.

The method for measuring the hygroscopic expansion coefficient is shown below. A sample having a width of 5 mm and a length of 20 mm is cut out from the produced cellulose acylate film, and one end is fixed and hung in an atmosphere of 25 ° C. and 20% RH (R0). A weight of 0.5 g was hung from the other end and left for 10 minutes to measure the length (H0). Next, the temperature is kept at 25 ° C., the humidity is set to 80% RH (R1), the sample is left for 24 hours, and the length (H1) is measured. The hygroscopic expansion coefficient is calculated by the following mathematical formula (10). The measurement is carried out 10 times for the same sample, and the average value is adopted.
Formula (10): Hygroscopic expansion coefficient (/% RH) = {(H1-H0) / H0} / (R1-R0)

  In order to reduce the dimensional change due to moisture absorption of the produced cellulose acylate film, it is possible to add the plasticizer or fine particles used in the present invention. A plasticizer having a polycyclic alicyclic structure having a bulky and hydrophobic property in the molecule seems to work effectively. Another effective means is to reduce the amount of residual solvent in the cellulose acylate film to reduce the free volume. Specifically, it is preferable that the residual solvent amount with respect to the cellulose acylate film is dried under the condition of 0.00.01 to 1.5% by mass. More preferably, it is 0.01-1.0 mass%.

(Equilibrium moisture content of film)
The equilibrium moisture content of the cellulose acylate film of the present invention is 25 ° C. regardless of the film thickness so as not to impair the adhesiveness with a water-soluble polymer such as polyvinyl alcohol when used as a transparent protective film of a polarizing plate. The equilibrium water content at 80% RH is preferably 0 to 4% by mass. The content is more preferably 0.1 to 3.5% by mass, and particularly preferably 1 to 3% by mass. If the equilibrium moisture content is less than or equal to the upper limit, it is preferable that the dependence of retardation on humidity change does not become too large when the cellulose acylate film is used as a transparent protective film of a polarizing plate.

  The moisture content was measured by curling the cellulose acylate film sample 7 mm × 35 mm of the present invention using a moisture measuring device “CA-03” and a sample drying device “VA-05” [both manufactured by Mitsubishi Chemical Corporation]. It was measured by the Fisher method. The moisture content is calculated by dividing the moisture content (g) by the sample mass (g).

(Water permeability of film)
The moisture permeability of the cellulose acylate film is measured under the conditions of a temperature of 60 ° C. and a humidity of 95% RH based on JIS standard JIS Z-0208, and the obtained value is converted to a film thickness of 80 μm. Translucent humidity 400~2000g / m ² · 24h, and it is more preferable 500~1800g / m ² · 24h, in particular in the range of 600~1600g / m ² · 24h. If the moisture permeability is equal to or less than the upper limit, it is preferable because the absolute value of the humidity dependency of the retardation value of the film rarely exceeds 0.5 nm /% RH. Even when an optically anisotropic layer is laminated on the cellulose acylate film of the present invention to form an optical compensation film, the absolute value of the humidity dependence of the Re value and Rth value rarely exceeds 0.5 nm /% RH. Therefore, it is preferable. In addition, when such a polarizing plate with an optical compensation sheet is incorporated in a liquid crystal display device, it is preferable because problems such as a change in color and a decrease in viewing angle are hardly caused. On the other hand, if the moisture permeability is equal to or greater than the lower limit, when a polarizing plate is produced by attaching to a polarizing film, the cellulose acylate film hinders drying of the adhesive and causes problems such as poor adhesion. It is preferable because it is difficult.

  If the film thickness of the cellulose acylate film is thick, the moisture permeability becomes small, and if the film thickness is thin, the moisture permeability becomes large. Therefore, it is necessary to convert the sample of any film thickness to a standard of 80 μm. Conversion of the film thickness is obtained as (water vapor permeability in terms of 80 μm = measured moisture permeability × measured film thickness μm / 80 μm).

The measurement method of moisture permeability is "Polymer Physical Properties II" (Polymer Experiment Course 4, Kyoritsu Shuppan), pages 285-294: Measurement of vapor permeation (mass method, thermometer method, vapor pressure method, adsorption amount method) The cellulose acylate film sample 70 mmφ of the present invention was conditioned at 25 ° C., 90% RH, 60 ° C., and 95% RH for 24 hours, respectively, and a moisture permeability test apparatus [“KK- 709007 “Toyo Seiki Co., Ltd.” calculates the amount of water per unit area (g / m ² ) according to JIS Z-0208, and obtains moisture permeability = mass after moisture conditioning−mass before moisture conditioning.

[surface treatment]
The cellulose acylate film is preferably surface-treated to improve the adhesion between the cellulose acylate film and the polarizing film. For example, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be used.

The glow discharge treatment here may be low-temperature plasma that occurs under a low pressure gas of 10 ^{−3 to} 20 Torr, and plasma treatment under atmospheric pressure is also preferred. Plasma-excitable gas refers to gas that is plasma-excited under the above conditions, such as argon, helium, neon, krypton, xenon, nitrogen, carbon dioxide, chlorofluorocarbons such as tetrafluoromethane, and mixtures thereof. can give. Details of these are described in detail on pages 30 to 32 in the Japan Society for Invention and Innovation Technical Report (Public Technical Number 2001-1745, published on March 15, 2001, Japan Institute of Invention), and are preferably used in the present invention. be able to.

(Saponification treatment)
Among these, an alkali saponification treatment is particularly preferable, and it is extremely effective as a surface treatment of a cellulose acylate film.

(1) Immersion method This is a technique in which a film is immersed in an alkaline solution under appropriate conditions to saponify all surfaces having reactivity with alkali on the entire surface of the film, and no special equipment is required. It is preferable from the viewpoint of cost. Examples of the alkali saponification solution include potassium hydroxide solution and sodium hydroxide solution, and the prescribed concentration of hydroxide ions is preferably in the range of 0.1 to 3.0 mol / L. Furthermore, as an alkali treatment liquid, a solvent (for example, isopropyl alcohol, n-butanol, methanol, ethanol, etc.) having good wettability to the film, a surfactant, a wetting agent (for example, diols, glycerin, etc.) is contained. Thus, the wettability of the saponification solution to the transparent protective film, the aging stability of the saponification solution, etc. are improved. The liquid temperature of a preferable alkali liquid is 25-70 degreeC, Most preferably, it is 30-60 degreeC.

  After being immersed in the alkaline solution, it is preferable that the film is sufficiently washed with water so that the alkali component does not remain in the film, or is immersed in a dilute acid to neutralize the alkali component.

  The transparent protective film used for the polarizing film is usually made by adhering the surface of the hydrophilic protective film having a contact angle to water of 20 ° to 50 °, more preferably 30 ° to 50 ° with the polarizing film. It is good to use. The hydrophilized surface is effective for improving the adhesion with a polarizing film containing polyvinyl alcohol as a main component.

(2) Alkaline solution coating method An alkali solution coating method in which an alkali solution is applied to only one side of the film under appropriate conditions, heated, washed and dried is preferably used. Examples of the alkaline solution and treatment include those described in JP-A No. 2002-82226, WO 02/46809 pamphlet and the like. It is extremely effective as a method for treating a film provided with a functional layer attached to the other surface of the film.

  The contact angle of the transparent protective film after the surface treatment with water is preferably in the range of 20 to 55 °. More preferably, it is 25 to 45 °.

  The surface energy of the transparent protective film is preferably 55 mN / m or more, and more preferably 55 to 75 mN / m. The surface energy can be determined by the contact angle method, the wet heat method, and the adsorption method as described in “Basics and Applications of Wetting” (Realize, 1989.12.10). The contact angle method is preferably used. Specifically, two types of solutions having known surface energies are dropped on the transparent protective film, and the tangent line drawn on the droplet and the surface of the transparent protective film are formed at the intersection of the surface of the liquid droplet and the surface of the transparent protective film. The angle that includes the droplet is defined as the contact angle, and the surface energy of the transparent protective film is calculated by calculation.

<Polarizing plate>
[Transparent protective film]
The polarizing plate of the present invention has a transparent protective film on both sides of the polarizing film. The kind of transparent protective film is not particularly limited, and cellulose esters such as cellulose acetate, cellulose acetate butyrate, and cellulose propionate, polycarbonate, polyolefin, polystyrene, polyester, and the like can be used. Commercially available products include “Fujitack” manufactured by Fuji Photo Film Co., Ltd., triacetyl cellulose film manufactured by Konica Corporation, “Zeonor” manufactured by Nippon Zeon Co., Ltd., “Arton” manufactured by Nippon Synthetic Rubber Co., Ltd. It is done. Other examples include non-birefringent optical resin materials as described in JP-A-8-110402 or JP-A-11-293116.

  The transparent protective film of the polarizing plate is required to have physical properties such as transparency, appropriate moisture permeability, low birefringence, and appropriate rigidity, and the film thickness is preferably 5 to 500 μm from the viewpoint of handleability and durability. 200 μm is more preferable, and 20 to 100 μm is particularly preferable. As the transparent protective film of the present invention, an embodiment using the above-mentioned “cellulose acylate film” is most preferable.

[Polarizing film]
The polarizing film of the present invention is preferably composed of polyvinyl alcohol (PVA) and dichroic molecules. However, as described in JP-A-11-248937, PVA and polyvinyl chloride are dehydrated and dechlorinated. A polyvinylene polarizing film in which a polyene structure is produced and oriented can also be used.

  PVA is a polymer material obtained by saponifying polyvinyl acetate, but may contain components copolymerizable with vinyl acetate such as unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, and vinyl ethers. . In addition, modified PVA containing an acetoacetyl group, a sulfonic acid group, a carboxyl group, an oxyalkylene group, or the like can also be used.

  The degree of saponification of PVA is not particularly limited, but is preferably 80 to 100 mol%, particularly preferably 90 to 100 mol% from the viewpoint of solubility and the like. The degree of polymerization of PVA is not particularly limited, but is preferably 1000 to 10,000, and particularly preferably 1500 to 5000.

  The syndiotacticity of PVA is preferably 55% or more for improving durability as described in Japanese Patent No. 2978219, but 45 to 52.5% described in Japanese Patent No. 3317494 is also preferably used. it can.

  PVA is preferably formed into a film and then a dichroic molecule is introduced to form a polarizing film. As a method for producing a PVA film, a method of forming a film by casting a stock solution obtained by dissolving a PVA resin in water or an organic solvent is generally preferably used. The concentration of the polyvinyl alcohol-based resin in the stock solution is usually 5 to 20% by mass, and a PVA film having a thickness of 10 to 200 μm can be produced by forming this stock solution by casting. The PVA film can be produced with reference to Japanese Patent No. 3342516, Japanese Patent Application Laid-Open No. 09-328593, Japanese Patent Application Laid-Open No. 13-302817, and Japanese Patent Application Laid-Open No. 14-144401.

  The crystallinity of the PVA film is not particularly limited. However, in order to reduce the average crystallinity (Xc) of 50 to 75% by mass and the in-plane hue variation described in Japanese Patent No. 3251073, Japanese Patent Application Laid-Open No. Hei 14- A PVA film having a crystallinity of 38% or less described in No. 236214 can be used.

The birefringence (Δn) of the PVA film is preferably small, and a PVA film having a birefringence of 1.0 × 10 ⁻³ or less described in Japanese Patent No. 3342516 can be preferably used. However, as described in JP-A-14-228835, in order to obtain a high degree of polarization while avoiding cutting during stretching of the PVA film, the birefringence of the PVA film may be set to 0.02 or more and 0.01 or less. Alternatively, as described in JP-A-14-060505, the value of (nx + ny) / 2-nz may be set to 0.0003 or more and 0.01 or less. Here, nx is the refractive index in the film longitudinal direction, ny is the refractive index in the film width direction, and nz is the refractive index in the film thickness direction.

  The retardation Re (in-plane) of the PVA film is preferably from 0 nm to 100 nm, and more preferably from 0 nm to 50 nm. Moreover, 0 nm or more and 500 nm or less are preferable, and, as for Rth (film thickness direction) of a PVA film, 0 nm or more and 300 nm or less are more preferable.

In addition, the polarizing plate of the present invention includes a PVA film having a 1,2-glycol bond amount of 1.5 mol% or less described in Japanese Patent No. 3021494, and 5 μm or more described in JP-A No. 13-316492. A PVA film having 500 or less optical foreign matter per 100 cm ² , a PVA film having a hot water cutting temperature spot in the TD direction of 1.5 ° C. or less of the film described in JP-A-14-030163, and glycerin A PVA film formed from a solution in which 1 to 100 parts by mass of a 3-6 valent polyhydric alcohol such as the above or a plasticizer described in JP-A-06-289225 is mixed in an amount of 15% by mass or more is preferably used. be able to.

  Although the film thickness before extending | stretching of a PVA film is not specifically limited, 1 micrometer-1 mm are preferable and 20-200 micrometers is especially preferable from a viewpoint of stability of film holding | maintenance and the uniformity of extending | stretching. As described in JP-A No. 14-236212, a thin PVA film may be used in which the stress generated when stretching 4 to 6 times in water is 10 N or less.

Dichroic molecule I ₃ ^- or I ₅ ^- can be preferably used iodine ion or a dichroic dye higher such. In the present invention, higher-order iodine ions are particularly preferably used. Higher-order iodine ions can be obtained by converting iodine into potassium iodide as described in “Application of Polarizing Plate” by Nagata Ryohen (CMC Publishing) and “Industrial Materials” Vol. 28, No. 7, pages 39-45. PVA can be immersed in a solution dissolved in an aqueous solution and / or an aqueous boric acid solution, and can be produced in a state of being adsorbed and oriented in PVA.

  When a dichroic dye is used as the dichroic molecule, an azo dye is preferable, and a bisazo dye and a trisazo dye are particularly preferable. The dichroic dye is preferably a water-soluble dye. For this reason, a hydrophilic substituent such as a sulfonic acid group, an amino group, or a hydroxyl group is introduced into the dichroic molecule, and a free acid or an alkali metal salt, an ammonium salt, an amine is introduced. It is preferably used as a salt.

  Specific examples of such dichroic dyes include C.I. I. Direct Red 37, Congo Red (C.I. Direct Red 28), C.I. I. Direct Violet 12, C.I. I. Direct Blue 90, C.I. I. Direct Blue 22, C.I. I. Direct Blue 1, C.I. I. Direct Blue 151, C.I. I. Benzidines such as Direct Green 1; C.I. I. Direct Yellow 44, C.I. I. Direct Red 23, C.I. I. Diphenylurea series such as Direct Red 79; I. Stilbene series such as Direct Yellow 12; I. Dinaphthylamine type such as Direct Red 31; I. Direct Red 81, C.I. I. Direct Violet 9, C.I. I. Mention may be made of J acid systems such as Direct Blue 78.

  In addition, C.I. I. Direct Yellow 8, C.I. I. Direct Yellow 28, C.I. I. Direct Yellow 86, C.I. I. Direct Yellow 87, C.I. I. Direct Yellow 142, C.I. I. Direct Orange 26, C.I. I. Direct Orange 39, C.I. I. Direct Orange 72, C.I. I. Direct Orange 106, C.I. I. Direct Orange 107, C.I. I. Direct Red 2, C.I. I. Direct Red 39, C.I. I. Direct Red 83, C.I. I. Direct Red 89, C.I. I. Direct Red 240, C.I. I. Direct Red 242, C.I. I. Direct Red 247, C.I. I. Direct Violet 48, C.I. I. Direct Violet 51, C.I. I. Direct Violet 98, C.I. I. Direct Blue 15, C.I. I. Direct Blue 67, C.I. I. Direct Blue 71, C.I. I. Direct Blue 98, C.I. I. Direct Blue 168, C.I. I. Direct Blue 202, C.I. I. Direct Blue 236, C.I. I. Direct Blue 249, C.I. I. Direct Blue 270, C.I. I. Direct Green 59, C.I. I. Direct Green 85, C.I. I. Direct Brown 44, C.I. I. Direct Brown 106, C.I. I. Direct Brown 195, C.I. I. Direct Brown 210, C.I. I. Direct Brown 223, C.I. I. Direct Brown 224, C.I. I. Direct Black 1, C.I. I. Direct Black 17, C.I. I. Direct Black 19, C.I. I. Direct Black 54 and the like, and further, JP-A-62-270802, JP-A-1-161202, JP-A-1-172906, JP-A-1-172907, JP-A-1-183602, JP-A-1-248105. The dichroic dyes described in JP-A-1-265205 and JP-A-7-261024 can also be preferably used. In order to produce dichroic molecules having various hues, two or more of these dichroic dyes may be blended. When a dichroic dye is used, the adsorption thickness may be 4 μm or more as described in JP-A No. 14-082222.

  If the content of the dichroic molecule in the film is too small, the degree of polarization is low, and if it is too large, the single-plate transmittance is lowered. Therefore, the polyvinyl alcohol polymer constituting the film matrix is usually used. On the other hand, it is adjusted in the range of 0.01% by mass to 5% by mass.

  A preferable film thickness of the polarizing film is in the range of 5 to 40 μm, further 10 to 30 μm, particularly 10 to 22 μm. Even when the thickness of the polarizing film is reduced to 5 to 22 μm, the transmittance at 700 nm when the polarizing film is crossed Nicol is 0.001% or more and 0.3% or less, and the transmittance at 410 nm is 0. The aspect which makes it 0.001% or more and 0.3% or less is preferable. The upper limit of the 700 nm transmittance during crossed Nicols is preferably 0.3% or less, and preferably 0.2%. The upper limit of the transmittance at 410 nm is preferably 0.3% or less, more preferably 0.08% or less, and further preferably 0.05% or less. This improves the light leakage failure (picture frame failure) from the periphery of the image display device caused by the contraction of the polarizing film due to changes over time, shows a neutral gray color with less bluishness, and provides good display image quality. Can be achieved.

  When the thickness of the polarizing film is reduced to 5 to 22 μm, as a means for reducing the transmittance at 700 nm and the transmittance at 410 nm at the time of crossed Nicols, in addition to the dichroic substance such as iodine, the polarizing film can be used. It is effective to add the above-mentioned dichroic dye having absorption in the wavelength range to be used as a hue adjusting agent, and to add a hardening agent such as boric acid when adding a dichroic substance such as iodine. I found out. It is also effective to combine these.

  Two or more kinds of the hue adjusting agents may be blended. The dye to be added achieves the object of the present invention if it has an absorption at 410 nm or 700 nm, but it preferably has a main absorption at 380 nm to 500 nm or 600 nm to 720 nm. Further, the amount of the dye to be added can be arbitrarily determined depending on the absorbance, dichroic ratio, etc. of the dye to be used. In any case, there is no particular limitation as long as the transmittance at 700 nm during crossed Nicol is 0.3% or less and the transmittance at 410 nm is 0.3% or less.

  Moreover, as a method for adding the hue adjusting agent to the polarizing film, any method such as dipping, coating, spraying and the like can be used. Among them, dipping is preferable. The step of adding may be before stretching or after stretching, but is preferably before stretching from the viewpoint of improving the polarization performance. The addition step may be provided alone, or may be performed in either or both of the dyeing step and the hardener addition step described later.

  As described in JP-A No. 14-174727, the ratio of the thickness of the polarizing film to the thickness of the transparent protective film described later is 0.01 ≦ A (film thickness of the polarizing film) / B (transparent protective film). It is also preferable that the thickness is in the range of ≦ 0.16.

  It is preferable that the transparent protective film is usually supplied in a roll form, and is continuously bonded to a long polarizing film so that the longitudinal directions thereof coincide. Here, the orientation axis (slow axis) of the protective film may be any direction, and the orientation axis of the protective film is preferably parallel to the longitudinal direction from the viewpoint of simplicity in operation.

  Further, the angle between the slow axis (orientation axis) of the protective film and the absorption axis (stretching axis) of the polarizing film is not particularly limited, and can be appropriately set according to the purpose of the obtained polarizing plate. Since the long polarizing plate in the present invention has an absorption axis that is not parallel to the longitudinal direction, when a protective film whose orientation axis is parallel to the longitudinal direction is continuously bonded to the long polarizing plate, A polarizing plate in which the absorption axis and the orientation axis of the protective film are not parallel can be obtained. A polarizing plate bonded with an angle at which the absorption axis of the polarizing film and the orientation axis of the protective film are not parallel has an effect of excellent dimensional stability. This performance is preferably exhibited particularly when used in a liquid crystal display device. In particular, when the inclination angle between the slow axis of the protective film and the absorption axis of the polarizing film is 10 ° or more and less than 90 °, the dimensional stability effect is effectively exhibited, preferably 20 ° or more and 70 ° or less.

[Swelling adjustment of polymer film for polarizing plate / Addition method of dichroic substance and hardener]
Moreover, the polarizing plate of the present invention can be produced by a swelling process, a dyeing process, a hardening process, a stretching process, a drying process, a transparent protective film bonding process, and a drying process after bonding. It is also possible to change the order of the above-mentioned dyeing process, hardening process, and stretching process arbitrarily, or to perform several processes in combination at the same time. In particular, the polarizing plate of the present invention can be suitably produced by performing the swelling step, the dyeing step, and the drying step as follows.

(B) In the swelling step, when the polymer film for polarizing plate is a PVA film, it is immersed in water or the like in advance in order to promote dyeing of iodine, which is a dichroic substance. 50 ° C. or lower, preferably 35 ° C. or higher and 45 ° C. or lower.
(B) Iodine, which is a dichroic substance, is dyed on the polarizing plate polymer film in the dyeing step. At this time, boric acid, which is a hardening agent, is added in a mass ratio of 1 to 30 times with respect to iodine.
(C) The polarizing film stretched in the drying step is dried, and the temperature at this time is 80 ° C. or lower, preferably 70 ° C. or lower.
The description of each step will be described later.

(Method of reducing the thickness of the polarizing film)
The method of reducing the thickness of the polarizing film can be achieved by a method of increasing the draw ratio or using a thin PVA film in the conventional drawing method. The film thickness of the PVA film that is usually used is 75 μm [for example, “VF-P”, “VF-PS”, etc., manufactured by Kuraray Co., Ltd.], but in this case, it is 8 in the longitudinal uniaxial stretching method in the longitudinal direction. When the film is stretched about twice or more, the thickness of the polarizing film becomes 20 μm or less. If the horizontal uniaxial stretching method is stretched 4 times or more by a tenter method or the like, the thickness of the polarizing film becomes 20 μm or less. Moreover, the film thickness of a polarizing film will be 20 micrometers or less by making the film thickness of a PVA film into 50 micrometers or less and extending | stretching about 6 times or more by uniaxial stretching.

  In the present invention, in addition to these uniaxial stretching methods, a stretching method in which the polarizing film polymer film is produced by uniaxial stretching in the transport direction or after uniaxial stretching and then stretching in the transverse direction can also be used. This method is a method generally called biaxial stretching. As a general method, a simultaneous biaxial stretching method using a tenter method, a simultaneous biaxial stretching method using a tubular method, and the like are known. In this method, when a 75 μm thick PVA film is stretched about 4 times or more in the vertical direction and about 1.5 times or more in the horizontal direction, the thickness of the polarizing film becomes 20 μm or less.

  A preferred stretching method in the present invention is an oblique stretching method described in JP-A No. 2002-86554. In this stretching method, by stretching a PVA film having a PVA film thickness of 125 μm or less four times or more, the polarizing film has a thickness of 20 μm or less.

  In the present invention, from the viewpoint of failure that causes light leakage (frame failure) and weight reduction of the polarizing plate member, the polarizing film is preferably thin. However, if it is too thin, the film may be cut or dyed during stretching. Problems such as having an adverse effect on handling when immersed in a liquid or a dura mater or causing cracks during drying after stretching occur. Therefore, in the present invention, the thickness of the polarizing film is preferably 5 μm or more and 22 μm or less, more preferably 8 μm or more and 20 μm or less.

[Description of each process]
Hereinafter, each process in producing the polarizing plate of this invention is demonstrated.

(Swelling process)
The swelling step is preferably performed only with water, but as described in JP-A-10-153709, in order to stabilize optical performance and avoid wrinkling of the polarizing film substrate in the production line, It is also possible to manage the degree of swelling of the polarizing film substrate by swelling the polarizing film substrate with an aqueous boric acid solution.
Further, the temperature and time of the swelling step can be arbitrarily determined, but preferably 10 ° C. to 50 ° C., 5 seconds or more. When no dichroic dye is used, 30 ° C. or more and 50 ° C. or less as described above, The temperature is preferably 35 ° C. or higher and 45 ° C. or lower for 5 seconds or longer and 600 seconds or shorter, preferably 15 seconds or longer and 300 seconds or shorter.

(Dyeing process)
For the dyeing step, the method described in JP-A-2002-86554 can be used. Moreover, as a dyeing method, not only immersion but any means such as application or spraying of iodine or a dye solution is possible. Although the dichroic material used for dyeing is not particularly limited, it is preferable to use iodine in order to obtain a high-contrast polarizing plate. The dyeing process is preferably performed in a liquid phase.

  In the case of using iodine, the PVA film is immersed in an iodine-potassium iodide aqueous solution. Iodine is preferably 0.05 to 20 g / L, potassium iodide is preferably 3 to 200 g / L, and the mass ratio of iodine and potassium iodide is preferably 1 to 2000. The dyeing time is preferably 10 to 1200 seconds, and the liquid temperature is preferably 10 to 60 ° C. More preferably, the iodine is 0.5 to 2 g / L, the potassium iodide is 30 to 120 g / L, the mass ratio of iodine to potassium iodide is 30 to 120, the dyeing time is 30 to 600 seconds, and the liquid temperature is 20 ˜50 ° C.

  As described above, it is also effective to add a boron-based compound such as boric acid or borax as a hardening agent and simultaneously perform the dyeing step and the hardening step described later. When using boric acid, it is preferable to add 1 to 30 times by mass with respect to iodine. It is also effective to add a dichroic dye in this step, and the amount is preferably 0.001 to 1 g / L. In addition, it is important to keep the additive amount in the aqueous solution constant for maintaining the polarization performance. Therefore, when manufacturing continuously, iodine, potassium iodide, boric acid, dichroic dye, etc. It is preferable to manufacture while replenishing. Replenishment may be in a solution or solid state. When adding by a solution, you may make it high concentration and may add little by little as needed.

(Duramination process)
In the hardening step, it is preferable to immerse in the crosslinking agent solution or apply the solution to contain the crosslinking agent. Further, as described in JP-A-11-52130, the hardening process can be performed in several steps.

  As the cross-linking agent, the one described in US Reissue Patent No. 232897 can be used, and as described in Japanese Patent No. 3357109, a polyvalent aldehyde is used as the cross-linking agent in order to improve dimensional stability. However, boric acids are most preferably used.

  When boric acid is used as the crosslinking agent used in the hardening step, metal ions may be added to the boric acid-potassium iodide aqueous solution. Zinc chloride is preferable as the metal ion. However, as described in JP-A No. 2000-35512, zinc halide such as zinc iodide, zinc sulfate such as zinc acetate is used instead of zinc chloride. It can also be used.

  Preferably, a boric acid-potassium iodide aqueous solution to which zinc chloride is added is prepared, and the PVA film is dipped to perform hardening. Boric acid is preferably 1-100 g / L, potassium iodide is 1-120 g / L, zinc chloride is 0.01-10 g / L, hardening time is preferably 10-1200 seconds, and liquid temperature is preferably 10-60 ° C. . More preferably, boric acid is 10 to 80 g / L, potassium iodide is 5 to 100 g / L, zinc chloride is 0.02 to 8 g / L, hardening time is 30 to 600 seconds, and liquid temperature is 20 to 50 ° C. It is. As described above, it is also effective to add a dichroic dye in this step and simultaneously perform the dyeing step, the details of which have already been described.

(Stretching process)
As described above, the stretching can be performed by using a uniaxial stretching method as described in US Pat. No. 2,454,515 after adjusting the film to be a polarizing film of 22 μm or less after stretching. . In this invention, it is also preferable to carry out by the diagonal stretch method by a tenter system as described in Unexamined-Japanese-Patent No. 2002-86554.

Hereinafter, the oblique stretching method used in the present invention will be described.
FIG. 1 is a schematic plan view showing a typical example of a method of obliquely stretching a polymer film. The oblique stretching method used in the present invention includes a step of introducing the original film shown in (a) in the direction of arrow (A), a widthwise drawing step shown in (b), and a stretched film shown in (c). The next process, that is, the process of sending in the (B) direction is included. Hereinafter, when referred to as “stretching step”, it refers to the entire step for performing the oblique stretching method used in the present invention, including these steps (a) to (c).

  The film is continuously introduced from the direction of (A) and is held for the first time at the B1 point by the holding means on the left side as viewed from the upstream side. At this point, one film end is not yet held, and no tension is generated in the width direction. That is, the point B1 does not correspond to a substantial holding start point (hereinafter referred to as “substantial holding start point”). In the method used in the present invention, the substantial holding start point is defined as the point at which both ends of the film are held for the first time. The substantial holding start point is indicated by two points: a holding start point A1 on the further downstream side, and a point C1 where a straight line drawn substantially perpendicularly to the introduction film 21 from A1 intersects the locus 23 of the holding means on the opposite side. . Starting from this point, if the holding means at both ends are conveyed at substantially constant speed, A1 moves as A2, A3... An every unit time, and C1 is similarly C2, C3. Move to. That is, the straight line connecting the points An and Cn through which the holding means serving as a reference passes at the same point is the extending direction at that time.

In the oblique stretching method, An is gradually delayed with respect to Cn as shown in FIG. 1, so that the stretching direction is gradually inclined from the vertical in the transport direction. The substantial holding release point (hereinafter referred to as “substantial holding release point”) is a straight line drawn substantially perpendicularly to the center line 22 of the film sent from the Cx to the next process, and the Cx point separating from the holding means upstream. Is defined by two points Ay that intersect the trajectory 24 of the holding means on the opposite side. The final film stretching direction angle is determined by the difference between the left and right holding means strokes Ay-Ax (ie, | L1-L2 |) at the end point (substantially holding release point) of the substantive drawing step, and the substantial holding releasing point. It is determined by the ratio of the distance W (the distance between Cx and Ay). Therefore, the inclination angle θ formed by the stretching direction with respect to the transport direction to the next process is an angle that satisfies the following formula (11).
Formula (11): tan θ = W / | L1-L2 |
The upper film end in FIG. 1 is maintained up to 28 after the Ay point, but the other end is not held, so no new width direction stretching occurs, and 28 is not a substantial holding release point.

  As described above, in the oblique stretching method, the substantial holding start points at both ends of the film are not simple biting points into the left and right holding means. The two real holding start points can be described more precisely as defined above. A straight line connecting one of the left and right holding points and the other holding point is introduced into the process of holding the film. And these two holding points are defined as those located most upstream. Similarly, in the present invention, the two substantially holding release points are such that the straight line connecting either the left or right holding point and the other holding point is substantially perpendicular to the center line of the film sent to the next process. And these two retention points are defined as being most downstream. Here, “substantially orthogonal” means that the straight line connecting the center line of the film and the right and left substantial holding start points or substantial holding release points is 90 ± 0.5 °.

When using a tenter-type stretching machine to create a left / right stroke difference, due to mechanical restrictions such as rail length, a large deviation often occurs between the biting point to the holding means and the actual holding start point, or the holding means. There is a case where a large deviation occurs between the separation point and the substantial retention release point, but the process between the substantial retention start point and the substantial retention release point defined above satisfies the relationship of the following formula (1), And if the difference of the conveyance speed of the longitudinal direction of both holding means is less than 1%, the objective of this invention will be achieved. The difference in transport speed is more preferably less than 0.5%, and most preferably less than 0.05%. The speed described here is the length of the trajectory traveled by the left and right holding means per minute. In general tenter drawing machines, etc., there are speed irregularities that occur in the order of seconds or less depending on the period of the sprocket teeth that drive the chain, the frequency of the drive motor, etc. This does not correspond to the speed difference described in the invention.
Formula (1): | L2-L1 |> 0.4W

  Further, when stretching the polymer film for polarizing film, it is preferable that the polymer film for polarizing film is stretched while the volatile content is maintained at 5% by volume or more, and then the volatile content is decreased while shrinking. . Thereby, generation | occurrence | production of the wrinkle and twist of a film can be prevented. In addition, the volatile content rate in this invention represents the volume of the volatile component contained per unit volume of a film, and is the value which divided the volatile component volume by the film volume.

As a method of containing volatile matter,
(1) Cast the film to contain solvent and water.
(2) Immerse / apply / spray in solvent / water before stretching,
(3) Apply solvent / water during stretching.
Can be raised. Since hydrophilic polymer films such as polyvinyl alcohol contain water in a high-temperature and high-humidity atmosphere, they can contain volatile components by stretching after conditioning in a high-humidity atmosphere or by stretching under high-humidity conditions. . Other than these methods, any means may be used as long as the volatile content of the polymer film can be increased to 5% by volume or more.

  The preferred volatile content varies depending on the type of polymer film. The maximum volatile content is possible as long as the support of the polymer film is maintained. In the case of polyvinyl alcohol, 10 to 100% by volume is preferable as the volatile fraction. In cellulose acylate, 10 to 200 volume% is preferable.

(Drying process)
The drying conditions follow the method described in JP-A-2002-86554, but as described above, the temperature is preferably 80 ° C. or lower, preferably 70 ° C. or lower. A preferred drying time is 30 seconds to 60 minutes.

(Transparent protective film bonding process)
The polarizing film produced in the present invention is provided as a polarizing plate by attaching a transparent protective film on both sides. The two transparent protective films may be the same or different. The polarizing film and the transparent protective film are preferably bonded together with a pair of rolls so that the adhesive liquid is supplied immediately before the bonding and the polarizing film and the transparent protective film are overlapped. The thickness of the adhesive layer after drying is preferably 0.001 to 5 μm, and more preferably 0.005 to 3 μm.

  Further, as described in JP-A-2001-296426 and JP-A-2002-86554, a polarizing film at the time of bonding is used to suppress the groove-like unevenness of the record due to stretching of the polarizing film. The moisture content is preferably adjusted, and in the present invention, it is preferably 0.1 to 30% by mass.

  The adhesive between the polarizing film and the transparent protective film is not particularly limited, but PVA-based resins (including modified PVA into which an acetoacetyl group, a sulfonic acid group, a carboxyl group, an oxyalkylene group, etc. are introduced), an aqueous boron compound solution, etc. Among them, PVA resin is preferable.

(Drying process after bonding)
The drying conditions after bonding are in accordance with the method described in JP-A-2002-86554, but the preferred temperature range is 30 ° C. to 100 ° C., and the preferred drying time is 30 seconds to 60 minutes.

As for the polarizing plate produced by the above process, the element content in a polarizing film is iodine 0.1-3.0 g / m < ² >, boron 0.1-5.0 g / m < ² >, potassium 0.1-2. .0g / m ^2, it is preferred that zinc 0.001~2.0g / m ^2. In particular, the single plate transmittance is preferably 42.5% or more. For this purpose, it is preferable to lower the iodine content, and the preferable iodine content is 0.1 to 1.0 g / m ^2. It is.

  Further, as described in Japanese Patent No. 3323255, in order to increase the dimensional stability of the polarizing plate, an organic titanium compound and / or an organic zirconium compound is added in any of the dyeing process, the stretching process, and the hardening process. In addition, it can also contain at least one compound selected from organic titanium compounds and organic zirconium compounds.

[Characteristics of polarizing plate]
(Transmittance and degree of polarization)
The preferable single plate transmittance of the polarizing plate of the present invention is 42.5% or more and 49.5% or less, more preferably 42.8% or more and 49.0% or less. Moreover, the preferable range of parallel transmittance is 36% or more and 42% or less, and the preferable range of orthogonal transmittance is 0.001% or more and 0.05% or less. These transmittances are defined by the following formula (12) based on JIS Z-8701.

  Here, K, S (λ), y (λ), and τ (λ) are as follows.

S (λ): spectral distribution of standard light used for color display y (λ): color matching function in XYZ system τ (λ): spectral transmittance λ: measurement wavelength [nm]

  Moreover, the preferable range of the polarization degree in the polarizing plate of this invention is 99.900% or more and 99.999% or less based on the definition by following formula (13), More preferably, it is 99.940% or more and 99.99. 995% or less.

  Furthermore, the preferable range of the dichroic ratio (Rd) defined by the following formula (14) is 48 or more and 1215 or less, and more preferably 53 or more and 525 or less.

In the parallel transmittance of the polarizing plate of the present invention in the wavelength range of 440 to 670 nm, the difference ΔT between the maximum value T _max and the minimum value T _min of the parallel transmittance T is 6% or less, preferably 4% or less, More preferably it is 2% or less. Further, the transmittance ratio R _T1 (parallel transmittance at wavelength 490 nm / parallel transmittance at wavelength 550 nm) and transmittance ratio R _T2 (parallel transmittance at wavelength 610 nm / parallel transmittance at wavelength 550 nm) in the light transmission characteristics are both It is within the range of 1.00 ± 0.02, preferably within the range of ± 0.01. This is a preferred embodiment in a reflective or transflective liquid crystal display device.

The optical characteristics when the polarizing plates are arranged in crossed Nicols are those having a ratio of the absorption peak Ap _{1 in} the wavelength range of 550 to 650 nm / absorption peak Ap ₂ in the wavelength range of 450 to 520 nm in the absorbance characteristic of 1.5 or less. Is preferred. More preferred is 1.4 or less, particularly preferred is 1.2 or less. This is preferable from the viewpoint of enhancement of blackness by reducing leakage light when arranged in crossed Nicols, that is, neutral hue.

Further, the parallel transmittance Tp ₄₄₀ and the orthogonal transmittance Tc _{440 at} the wavelength ₄₄₀ nm, the parallel transmittance Tp ₅₅₀ and the orthogonal transmittance Tc _{550 at} the wavelength ₅₅₀ nm, and the parallel transmittance Tp ₆₁₀ and the orthogonal transmittance Tc _{610 at the} wavelength 610 nm, It is preferable that the following mathematical expressions (15) to (18) are satisfied simultaneously.
Formula (15): 0.85 ≦ Tp ₄₄₀ / Tp ₅₅₀ ≦ 1.10
Equation _{(16): 0.90 ≦ Tp 610} / Tp 550 ≦ 1.10
Equation _{(17): 1.0 ≦ Tc 440} / Tc 550 ≦ 8.0
Formula (18): 0.08 ≦ Tc ₆₁₀ / Tc ₅₅₀ ≦ 1.10

  Within these ranges, in a reflective or transflective liquid crystal display device, there are few variations and variations in orthogonal transmittance at three wavelengths having bright line peaks (wavelengths of 440 nm, 550 nm and 610 nm) of the backlight. As a result, a good display image having no problem in vivid color reproducibility can be obtained.

  Also, the standard deviation of parallel transmittance every 10 nm when the light wavelength is between 420 and 700 nm is 3 or less, and every 10 nm when the light wavelength is between 420 and 700 nm (parallel transmittance / orthogonal transmission). The minimum value of the rate is preferably 300 or more. As a result, a contrasted display image is obtained on the liquid crystal display device, and the display color when the white screen is displayed is effective for neutralization.

(Hue)
The hue of the polarizing plate of the present invention is preferably evaluated using the lightness index L ^* and the chromaticness indices a ^* and b ^* in the L ^* a ^* b ^* color system recommended as the CIE uniform perception space. L ^* , a ^* , and b ^* are defined by Equation (19) using the above X, Y, and Z.

Here, X ₀ , Y ₀ , Z ₀ represent tristimulus values of the illumination light source. In the case of the standard light C, X ₀ = 98.072, Y ₀ = 100, Z ₀ = 118.225, and the standard light D _In the case of ₆₅ , X ₀ = 95.045, Y ₀ = 100, and Z ₀ = 108.892.

The preferable range of a ^* for a single polarizing plate is −2.5 to 0.2, and more preferably −2.0 to 0. A preferable range of b ^* of the single polarizing plate is 1.5 or more and 5 or less, and more preferably 2 or more and 4.5 or less. The preferable range of a ^* of the parallel transmitted light of the two polarizing plates is −4.0 to 0, and more preferably −3.5 to −0.5. A preferable range of b ^* of parallel transmitted light of the two polarizing plates is 2.0 or more and 8 or less, and more preferably 2.5 or more and 7 or less. The preferred range of a ^* of the orthogonally transmitted light of the two polarizing plates is −0.5 or more and 2 or less, and more preferably 0 or more and 1.0 or less. The preferable range of b ^* of the orthogonally transmitted light of the two polarizing plates is −2.0 or more and 2 or less, and more preferably −1.5 or more and 0.5 or less.

The hue may be evaluated by the chromaticity coordinates (x, y) calculated from the aforementioned X, Y, and Z. For example, the chromaticity (x _p , y _p ) of the parallel transmitted light of the two polarizing plates. And the chromaticity (x _c , y _c ) of the orthogonal transmitted light are in the ranges described in JP-A-14-214436, JP-A-13-166136 and JP-A-14-169024, or the relationship between hue and absorbance. It can also be preferably performed within the range described in JP-A No. 13-311827.

(Viewing angle characteristics)
When the polarizing plate is placed in crossed Nicol and light with a wavelength of 550 nm is incident, when normal light is incident, it is incident at an angle of 40 ° with respect to the normal from the direction of 45 ° with respect to the polarization axis. In this case, the transmittance ratio and the xy chromaticity difference are preferably in the ranges described in JP-A Nos. 13-166135 and 13-166137. Further, as described in JP-A-10-068817, the light transmittance (T ₀ ) in the vertical direction of the polarizing plate laminate having the crossed Nicols arrangement and the light transmission in the direction inclined by 60 ° from the normal line of the laminate. The ratio (T ₆₀ / T ₀ ) with respect to the rate (T ₆₀ ) is set to 10,000 or less, or as described in JP-A No. 14-139625, the polarizing plate has an arbitrary angle from the normal to an elevation angle of 80 °. When natural light is incident, the transmittance difference of transmitted light within a wavelength range of 20 nm within the wavelength range of 520 to 640 nm of the transmission spectrum is set to 6% or less, or a film described in JP-A-08-248201 It is also preferable that the brightness difference of the transmitted light at an arbitrary place 1 cm above is within 30%.

(Degree of orientation)
The higher the degree of orientation of PVA, the better the polarization performance. However, the order parameter value calculated by means such as polarized Raman scattering or polarized FT-IR is preferably 0.2 to 1.0. Also, as described in JP-A-59-133509, the difference between the orientation coefficient of the polymer segment in the entire amorphous region of the polarizing film and the orientation coefficient of the occupied molecule (0.75 or more) is at least 0.3. 15, as described in JP-A-04-204907, the orientation coefficient of the amorphous region of the polarizing film is 0.65 to 0.85, or the orientation of higher order iodine ions of I ₃ and I ₅ It is also preferable to set the degree to 0.8 to 1.0 as an order parameter value.

<Polarizing plate with antireflection ability>
The polarizing plate of the present invention is a polarizing plate with antireflection ability formed by coating the above-described antireflection film on a polarizing plate comprising the above polarizing film and its transparent protective film on one transparent protective film.

The polarizing plate provided with the antireflection film is produced by the following methods (1) to (3).
(1) Adhering the surface opposite to the antireflection film of the transparent protective film on which the antireflection film is laminated and the surface on the polarizing film side of the polarizing plate formed by bonding the transparent protective film to the polarizing film Paste together using an agent.
(2) The surface opposite to the antireflection film of the transparent protective film on which the antireflection film is laminated is subjected to surface hydrophilization treatment by saponification treatment or the like, and the polarizing film is bonded to the film surface using an adhesive.
(3) An antireflection film is coated on the transparent protective film of the polarizing plate formed by bonding the transparent protective film to the polarizing film.

  Since the polarizing plate can be thinned, the methods (2) to (3) are preferable embodiments. Furthermore, it is preferable that the transparent protective film provided with the antireflection film is continuously bonded by the method (2).

[Characteristics of anti-reflection polarizing plate]
[Optical characteristics and weather resistance]
(Reflectance)
In the polarizing plate with antireflection ability of the present invention, the average value of the specular reflectance at 5 ° incidence in the wavelength region from 450 nm to 650 nm (that is, the average reflectance) is preferably 2.5% or less, more preferably. Is 1.8% or less, more preferably 1.4% or less.

  The specular reflectance at 5 ° incidence is a ratio of the intensity of light reflected at −5 ° to the normal direction from the normal direction + 5 ° of the sample, and is a measure of reflection due to specular reflection of the background. Become. When applied as an antireflection film having an antiglare function, the intensity of the light reflected in the normal direction of −5 ° is weak by the amount of scattered light caused by surface irregularities provided for providing the antiglare property. Become. Therefore, specular reflectance can be said to be a measurement method that reflects the contribution of both antiglare and antireflection properties.

  If the average value of the specular reflectivity of the polarizing plate with antireflection at 5 ° incidence in the wavelength region from 450 nm to 650 nm is 2.5% or less, the reflection of the background is not anxious and display This is preferable because problems such as a decrease in visibility when applied to the surface film of the apparatus do not occur.

  Further, when the antireflection film of the present invention has a multilayer antireflection film, the average value of the specular reflectance at 5 ° incidence in the wavelength region from 450 nm to 650 nm (that is, the average reflectance) is 0. It is 5% or less, preferably 0.4% or less, more preferably 0.3% or less, and it is possible to prevent a decrease in visibility due to reflection of external light on the display device surface to a sufficient level.

  Furthermore, the change in average reflectance at a wavelength of 380 to 680 nm of the polarizing plate of the present invention before and after the light resistance test is preferably 0.4% or less, and more preferably 0.2% or less. In this range, there is no practical problem.

(Color and its in-plane change rate)
Antireflection performance with polarizing plate, the CIE standard illuminant D _65, for the 5 ° incident light at 780nm region from the wavelength 380 nm, of the specular reflection light in color, i.e. CIE1976L ^* a ^* b ^* color space L ^*, The a ^* and b ^* values are preferably in the ranges of 3 ≦ L ^* ≦ 20, 0 ≦ a ^* ≦ 7, and −10 ≦ b ^* ≦ 0, respectively. By setting it within this range, the color of reflected light from red purple to blue purple, which has been a problem with conventional polarizing plates, is reduced, and 3 ≦ L ^* ≦ 10, 0 ≦ a ^* ≦ 5, and − 7 ≦ b ^* ≦ 0 is greatly reduced, and when applied to a liquid crystal display device, when applied to a liquid crystal display device, such as indoor fluorescent light, the color tone when a little bright external light is reflected. Neutral, don't mind. Specifically, if a ^* ≦ 7, the reddishness will not be too strong, and if a ^* ≧ 0, the cyanishness will not be too strong. If b ^* ≧ −10, the bluish color does not become too strong, and if b ^* ≦ 0, the yellowish color does not become too strong.

In the present invention, it is preferable that the values of L ^* , a ^* , and b ^* are constant over the entire surface of the display image, and it is particularly preferable that the rate of change of each value in the plane is 20% or less. More preferably, it is 8% or less. In this range, a display image with good visibility without color unevenness is obtained.

The specular reflectance and color are measured by attaching an adapter “ARV-474” to a spectrophotometer V-550 [manufactured by JASCO Corporation] and emitting at an incident angle of 5 ° in the wavelength region of 380 to 780 nm. The antireflection property can be evaluated by measuring the specular reflectance at an angle of -5 ° and calculating the average reflectance of 450 to 650 nm. Furthermore, calculated from the measured reflection spectrum, L ^* value of the CIE1976L ^* a ^* b ^* color space representing the color of specular reflection light with respect to 5 ° incident light CIE standard light source D _65, a ^* value, and b ^* value Thus, the color of the reflected light can be evaluated.

  These are that the color of the transparent protective film itself and the fluctuation range thereof are suppressed within the above-mentioned range, and the unevenness of the uneven surface of the antireflection film coating surface is reduced in film thickness unevenness. By appropriately adjusting each component constituting the polarizing plate of the present invention, such as the formation of an antireflection film and the improvement of the neutrality of the color of the polarizing film, the color of the reflected light Unevenness is greatly reduced.

Furthermore, the color uniformity of the reflected light can be determined from the reflection spectrum of the reflected light from 380 nm to 680 nm, and each average value of a ^* b ^* is determined on the L ^* a ^* b ^* chromaticity diagram. * The difference (ΔA) between the maximum value and the minimum value is divided by the average value and multiplied by 100 to obtain the color change rate. The change rate is preferably 30% or less, more preferably 20% or less, and most preferably 8% or less.

  Further, in the polarizing plate with antireflection ability of the present invention, ΔE, which is a change in color before and after the weather resistance test, is preferably 15 or less, more preferably 10 or less, and most preferably 5 or less. preferable.

  In this range, it is possible to achieve both low reflection and reduction of the color of the reflected light. For example, when applied to the outermost surface of an image display device, there is a slight amount of high-brightness external light such as an indoor fluorescent lamp. The color tone when reflected is neutral, and the quality of the displayed image is good, which is preferable.

  The polarizing plate with antireflection ability of the present invention changes in a range in which these optical properties and mechanical properties of the antireflection film (tear strength, scratch strength, adhesion, etc.) are not substantially problematic even after the weather resistance test. It is characterized by being suppressed. In particular, the characteristic change is suppressed after the weather resistance test.

  The weather resistance test of the present invention is a weather resistance test based on JIS K-5600-7-7: 1999, a sunshine weather meter ["S-80" manufactured by Suga Test Instruments Co., Ltd.], 50% RH, treatment It means a weather resistance test according to 150 hours).

(Durability of light transmittance and polarization degree, temperature and / or humidity)
In the polarizing plate with antireflection ability of the present invention, the light transmittance and the rate of change of the degree of polarization before and after standing in an atmosphere of 60 ° C. and 90% RH for 500 hours are 3% or less based on absolute values. Is preferred. In particular, the change rate of the light transmittance is preferably 2% or less, and the change rate of the polarization degree is preferably 1.0% or less, more preferably 0.1% or less based on the absolute value. This can be achieved by a polarizing film made of a stretched film of a hydrophilic polymer containing 0.6% by mass or more of a dichroic substance, a cellulose acylate film preferable for the present invention having good moisture resistance, and the like. Further, as described in JP-A-07-0777608, it is also preferred that the degree of polarization after standing at 80 ° C. and 90% RH for 500 hours is 95% or more and the single transmittance is 38% or more.

  Furthermore, it is preferable that the light transmittance and the rate of change of the degree of polarization before and after leaving for 500 hours in a dry atmosphere at 80 ° C. are also 3% or less based on absolute values. In particular, the change rate of the light transmittance is preferably 2% or less, and the change rate of the polarization degree is preferably 1.0% or less, more preferably 0.1% or less based on the absolute value.

[Dimensional change rate]
When the polarizing plate with antireflection ability of the present invention is placed under heating conditions of 70 ° C. for 120 hours, the dimensional change rate in the absorption axis direction and the dimensional change rate in the polarization axis direction of the polarizing plate are both ± 0. It is preferably within 6%.

In the dimensional behavior during heating of the polarizing plate, there is little anisotropy between the change in the absorption axis direction and the change in the polarization axis direction of the polarizing plate. Warping of odd-shaped panels, which is a problem in assembling display devices, is eliminated. Therefore, it is more preferable that the dimensional change rate D _{A in} the absorption axis direction of the polarizing plate and the dimensional change rate D _{B in the} polarization axis direction satisfy the following relationship.
−0.05 <(Dimensional change rate D _A −Dimensional change rate D _B ) <+ 0.05

  These are the adjustment of the stretching in the polarizing film stretching process, the moisture content of the polarizing film when the transparent protective film is bonded (the water mass ratio in the polarizing film to the total mass of the polarizing film, the thickness of the polarizing film However, it is generally less than 20% by mass and preferably in the range of 13 to 17% by mass).

[Other durability]
Further, as described in JP-A-06-167611, the shrinkage after standing at 80 ° C. for 2 hours is 0.5% or less, or left at 80 ° C. and 90% RH for 200 hours. the change in spectral intensity ratio of the 105 cm ^-1 and 157cm ^-1 by Raman spectroscopy after treatment, it is also preferable to fall within the range as described in JP-a-08-094834 and JP-a-09-197127.

<Other functional layers>
The polarizing plate with antireflection ability of the present invention has a functional layer such as a λ / 4 plate for application to an LCD viewing angle widening film or a reflective LCD, as opposed to a transparent protective film having a polarizing film antireflection film. It is preferably used as a composite polarizing plate on the transparent protective film side.

[Optical compensation film]
The viewing side polarizing plate of the present invention is preferably formed by providing an optical compensation film on the opposite side of the polarizing plate provided with the antireflection film. This enables a wide viewing angle of the display image of the liquid crystal display device. The optical compensation function may be imparted by laminating an optical compensation film on the transparent protective film on the opposite side of the polarizing plate provided with the antireflection film, or by providing the optical compensation film function on the transparent protective film itself. Alternatively, a layer having an optical compensation function may be coated on the transparent protective film.

  Examples of the optical compensation film include a birefringent film obtained by uniaxially or biaxially stretching a polymer film, and a liquid crystal alignment film having an optically anisotropic layer made of a liquid crystalline material exhibiting birefringence on a transparent film. Etc. The thickness of the optical compensation film is not particularly limited, but is generally about 5 to 100 μm. Among these optical compensation films, a liquid crystal alignment film having an optically anisotropic layer on a transparent protective film is preferable.

  Examples of the polymer film material to be the birefringent film include polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, and polyethylene terephthalate. , Polyethylene naphthalate, polyethersulfone, polyphenylene sulfide, polyphenylene oxide, polyallylsulfone, polymethyl methacrylate, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulosic polymer, norbornene resin or binary of these, three Examples thereof include various copolymers, graft copolymers, and blends. These polymer materials become oriented products (stretched films) by stretching or the like.

[Liquid crystal alignment film]
The optically anisotropic layer is preferably designed so as to compensate for the liquid crystal compound molecules in the liquid crystal cell in the black display of the liquid crystal display device. The alignment state of the liquid crystal compound molecules in the liquid crystal cell in black display varies depending on the mode of the liquid crystal display device. The alignment state of the liquid crystal compound molecules in this liquid crystal cell is described in IDW'00, FMC 7-2, pages 411 to 414.

(Liquid crystal compound)
The liquid crystal compound used for the optically anisotropic layer may be a rod-like liquid crystal or a discotic liquid crystal, and these are high molecular liquid crystals or low molecular liquid crystals, and those in which low molecular liquid crystals are crosslinked and no longer exhibit liquid crystallinity. Including. Most preferred is a discotic liquid crystal.

  Preferable examples of the rod-like liquid crystal include those described in JP 2000-304932A.

  Examples of discotic liquid crystals include C.I. Destrade et al., Mol. Cryst. 71, 111 (1981), benzene derivatives described in C.I. Destrade et al., Mol. Cryst. 122, 141 (1985), Physics lett, A, 78, 82 (1990); Kohne et al., Angew. Chem. 96, page 70 (1984) and the cyclohexane derivatives described in J. Am. M.M. Lehn et al. Chem. Commun. , 1794 (1985), J. Am. Zhang et al., J. Am. Chem. Soc. 116, page 2655 (1994), and azacrown-based and phenylacetylene-based macrocycles.

  The discotic liquid crystal generally has a structure in which these are used as a mother nucleus at the center of a molecule, and a linear alkyl group, an alkoxy group, a substituted benzoyloxy group, etc. are radially substituted as the linear chain, and the liquid crystallinity is improved. Show. However, the molecule itself is not limited to the above description as long as the molecule itself has negative uniaxiality and can give a certain orientation. Further, in the present invention, the term “formed from a discotic compound” does not require that the final substance is the above-mentioned compound, for example, a low molecular discotic liquid crystal has a group that reacts with heat, light, or the like. As a result, it may be polymerized or cross-linked by reaction with heat, light, etc., resulting in high molecular weight and loss of liquid crystalline properties. Preferred examples of the discotic liquid crystal include those described in JP-A-8-50206.

  The optically anisotropic layer is generally formed by applying a solution obtained by dissolving a discotic compound and other compounds (for example, a plasticizer, a surfactant, a polymer, etc.) in a solvent onto the alignment film, drying, and then discotic nematic. It is obtained by heating to the phase formation temperature and then cooling while maintaining the orientation state (discotic nematic phase). Alternatively, the optically anisotropic layer is formed by applying a solution obtained by dissolving a discotic compound and another compound (for example, a polymerizable monomer, a photopolymerization initiator) in a solvent onto the alignment film, drying, and then discotic It is obtained by heating to the nematic phase formation temperature, polymerizing (by irradiation with UV light or the like), and further cooling.

  The thickness of the optically anisotropic layer is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm, and most preferably 0.7 to 5 μm. However, depending on the mode of the liquid crystal cell, it may be thick (3 to 10 μm) in order to obtain high optical anisotropy.

(Alignment film)
The alignment film is usually used because it has a function of defining the alignment direction of the liquid crystal compound molecules. However, if the alignment state is fixed after the liquid crystal compound is aligned, the alignment film plays its role. It is not necessarily essential as a component of the invention. For example, it is possible to produce the polarizing plate of the present invention by transferring only the optically anisotropic layer on the alignment film in which the alignment state is fixed onto the transparent protective film of the polarizing film.

  The alignment film is an organic compound (eg, ω-tricosanoic acid) by rubbing treatment of an organic compound (preferably polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodgett method (LB film). , Dioctadecylmethylammonium chloride, methyl stearylate). Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known.

  The alignment film is preferably formed by polymer rubbing treatment. In principle, the polymer used for the alignment film has a molecular structure having a function of aligning liquid crystal molecules.

  In the present invention, in addition to the function of aligning liquid crystal molecules, a crosslinkable functional group having a function of binding a side chain having a crosslinkable functional group (eg, a double bond) to the main chain or aligning liquid crystal molecules. Is preferably introduced into the side chain.

  As the polymer used in the alignment film, either a polymer that can be crosslinked by itself or a polymer that is crosslinked by a crosslinking agent can be used, and a plurality of combinations thereof can be used.

  Examples of the polymer used for the alignment film include, for example, a methacrylate copolymer, a styrene copolymer, a polyolefin, polyvinyl alcohol, and modified polyvinyl alcohol described in paragraph No. [0022] of JP-A-8-338913. , Poly (N-methylolacrylamide), polyester, polyimide, vinyl acetate copolymer, carboxymethylcellulose, polycarbonate and the like. Most preferred are polyvinyl alcohol and modified polyvinyl alcohol. Specific examples of the alignment film forming composition such as the modified polyvinyl alcohol compound and the crosslinking agent include those described in JP-A Nos. 2000-155216 and 2002-62426.

  The alignment film can basically be formed by applying the above polymer, which is an alignment film forming material, on a support, followed by heat drying (crosslinking) and rubbing treatment. As described above, the crosslinking reaction may be performed at an arbitrary time after coating on the support.

  The alignment film is preferably applied by spin coating, dip coating, curtain coating, extrusion coating, rod coating, or roll coating. A rod coating method is particularly preferable.

  Examples of the alignment film include a method of directly providing on the transparent protective film as a support, or a method of providing an alignment film after providing an undercoat layer on the transparent protective film. When providing directly on a support body, the said surface hydrophilization process is mentioned. As the support, it is preferable to use a transparent protective film of a polarizing plate.

  In addition, as the undercoat layer, for example, a single layer method in which a single undercoat layer described in JP-A-7-333433 or a resin layer such as gelatin containing both a hydrophobic group and a hydrophilic group is applied. A layer that adheres well to the polymer film (hereinafter abbreviated as the first undercoat layer) is provided as one layer, and a hydrophilic resin layer such as gelatin (hereinafter referred to as the undercoat first layer) that adheres well to the alignment film as the second layer thereon. The contents of a so-called multi-layer method (for example, described in JP-A No. 11-248940) in which two layers are applied) are mentioned.

The alignment film can be obtained by rubbing the surface after crosslinking the polymer layer as described above. Next, the alignment film functions to align the liquid crystal molecules of the optically anisotropic layer provided on the alignment film. Thereafter, if necessary, the alignment film polymer is reacted with the polyfunctional monomer contained in the optically anisotropic layer, or the alignment film polymer is crosslinked using a crosslinking agent.
The thickness of the alignment film is preferably in the range of 0.1 to 10 μm.

[Support for coating optically anisotropic layer made of liquid crystal compound]
The support for coating the optically anisotropic layer is not particularly limited as long as it is a plastic film having a high transmittance, but it is preferable to use cellulose acylate which is a transparent protective film of a polarizing plate. That is, it is preferable that an alignment film (not necessarily essential as described above) and an optically anisotropic layer are formed directly on the transparent protective film of the polarizing plate.

  Since the support on which the optically anisotropic layer is coated itself plays an optically important role, the Re retardation value of the support is adjusted to 0 to 200 nm, and the Rth retardation value is adjusted to 0 to 400 nm. It is preferred that

  The cellulose acylate film of the support preferably contains, as a retardation adjusting agent, a compound that absorbs ultraviolet rays having a wavelength (λmax) shorter than 400 nm that gives the absorption maximum of the ultraviolet absorption spectrum of the solution. Examples of such compounds include ultraviolet absorbing compounds such as phenyl salicylic acids, 2-hydroxybenzophenones, benzotriazoles, triphenyl phosphate and the like. In addition, an aromatic compound having at least two aromatic rings (for example, JP-A No. 2000-1111914), a triphenylene compound (for example, JP-A No. 2000-275434), and a rod-like compound (for example, JP-A No. 2002-363343). No. 2003-35821), discotic compounds (1,3,5-triazine skeleton, compounds containing a porphyrin skeleton in the molecule, etc .: for example, JP-A No. 2001-166144) and the like are preferable. These compounds preferably have substantially no absorption in the visible light region.

  The birefringence (Δn: nx−ny) of the support film is preferably 0 to 0.002. Further, the birefringence {(nx + ny) / 2−nz} in the thickness direction of the film is preferably 0.04 to 0.04.

The retardation value (Re) is calculated according to the following mathematical formula (20).
Formula (20): Retardation value (Re) = (nx−ny) × d
In the equation, nx is a refractive index in the slow axis direction in the plane of the retardation plate (maximum refractive index in the plane); ny is a refraction in a direction perpendicular to the slow axis in the plane of the retardation plate. Rate.

Formula (21): Retardation value (Rth) = {(nx + ny) / 2−nz} × d
In the formula, nx is the refractive index in the slow axis direction (the direction in which the refractive index is maximum) in the film plane. ny is the refractive index in the fast axis direction (direction in which the refractive index is minimized) in the film plane. nz is the refractive index in the thickness direction of the film. d is the thickness of the film whose unit is nm.

  The thickness of the cellulose acylate film used for the optical compensation film is preferably 20 to 200 μm, and more preferably 30 to 120 μm.

  When an optical compensation film is used as a protective film for a polarizing film, that is, when an optically anisotropic layer is formed on a transparent protective film and then bonded to the polarizing film, the surface to be bonded to the polarizing film is saponified. It is preferable to carry out according to the saponification treatment described above.

  The configuration of the viewing side polarizing plate is a laminated film of “antireflection film / transparent protective film / polarizing film / transparent protective film”, and further “antireflection film / transparent protective film / polarizing film / optical compensation film (transparent protective film / (Alignment film) / optically anisotropic layer) ", and further thinning, weight reduction and cost reduction are achieved. The upper transparent protective film of the polarizing plate serves as the antireflection film, and the lower transparent protective film serves as the support on which the optically anisotropic layer is coated, so that it has excellent physical strength and weather resistance and has an antireflection function. In addition, a thin and light polarizing plate having excellent visibility can be obtained.

  Here, the polarizing plate and the optical compensation film have the same contents as described in the viewing side polarizing plate (upper polarizing plate).

<Image display device>
The image display device of the present invention is characterized in that the above-mentioned polarizing plate with antireflection ability of the present invention is disposed on the image display surface. Thus, the polarizing plate with antireflection ability of the present invention can be applied to an image display device such as a liquid crystal display device (LCD) or an organic EL display. The image display device of the present invention is preferably applied to a transmissive, reflective, or transflective liquid crystal display device in any of TN, STN, IPS, VA, and OCB modes. This will be further described below.

  Any conventionally known liquid crystal display device can be used. For example, supervised by Tatsuo Uchida, “Reflective Color LCD Comprehensive Technology” [CMC, 1999], “New Development of Flat Panel Display” [Toray Research Center, Inc., Research Division, 1996], “Liquid Crystal Related Markets” And the future prospects (first volume), (second volume) "[Fuji Chimera Research Institute, Inc., published in 2003], and the like.

  Specifically, for example, a transmissive type or a reflective type such as twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), or optically compensated bend cell (OCB). It can be preferably used for a liquid crystal display device of a type or a transflective type.

  In addition, the polarizing plate of the present invention has a good contrast and a wide viewing angle even when the size of the attached display image of the liquid crystal display device is 17 inches or more, and prevents hue change and transfer of external light. Realizable and preferred.

[TN mode liquid crystal display]
The TN mode liquid crystal cell is most frequently used as a color TFT liquid crystal display device, and many literatures are cited. The alignment state in the liquid crystal cell in the TN mode black display is an alignment state in which the rod-like liquid crystal molecules rise at the center of the cell and the rod-like liquid crystal molecules lie near the cell substrate.

[OCB mode liquid crystal display]
The OCB mode liquid crystal cell is a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in a substantially opposite direction (symmetrically) between the upper part and the lower part of the liquid crystal cell. Since the liquid crystal display device using the bend alignment mode liquid crystal cell is aligned symmetrically between the upper part and the lower part of the liquid crystal cell, the devices disclosed in the specifications of US Pat. Nos. 4,583,825 and 5,410,422 are provided. The bend alignment mode liquid crystal cell has a self-optical compensation function. For this reason, this liquid crystal mode is also called an OCB (Optically Compensatory Bend) liquid crystal mode.

  Similarly to the TN mode, the liquid crystal cell in the OCB mode is in a black display, and the alignment state in the liquid crystal cell is such that the rod-like liquid crystal molecules rise in the center of the cell and the rod-like liquid crystal molecules lie in the vicinity of the cell substrate. .

[VA mode liquid crystal display]
In a VA mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially vertically when no voltage is applied.

  The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). (2) In addition to the liquid crystal cell [SID97, Digest of Tech. Papers 28 (1997) 845], (3) Liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied. (Preliminary collections 58-59 (1998) of the Japanese Liquid Crystal Discussion Group) and (4) SURVAVAL mode liquid crystal cells (presented at LCD International 98).

[IPS mode liquid crystal display]
In the IPS mode liquid crystal cell, the liquid crystal molecules are always rotated in a horizontal plane with respect to the substrate, and are aligned so as to have a slight angle with respect to the longitudinal direction of the electrode when no electric field is applied. When an electric field is applied, the liquid crystal molecules change direction in the direction of the electric field. The light transmittance can be changed by arranging the polarizing plates sandwiching the liquid crystal cell at a predetermined angle. As the liquid crystal molecules, nematic liquid crystal having a positive dielectric anisotropy Δε is used. The thickness (gap) of the liquid crystal layer is more than 2.8 μm and less than 4.5 μm. This is because when the retardation Δn · d is more than 0.25 μm and less than 0.32 μm, a transmittance characteristic having almost no wavelength dependency within the visible light range can be obtained. By combining the polarizing plates, the maximum transmittance can be obtained when the liquid crystal molecules are rotated 45 ° from the rubbing direction to the electric field direction. The thickness (gap) of the liquid crystal layer is controlled by polymer beads. Of course, the same gap can be obtained with glass bead fiber or resin columnar spacers. The liquid crystal molecules are not particularly limited as long as they are nematic liquid crystals. The larger the value of the dielectric anisotropy Δε, the lower the driving voltage, and the smaller the refractive index anisotropy Δn, the thicker the liquid crystal layer (gap), the shorter the liquid crystal sealing time, and the gap. Variation can be reduced.

[Other LCD mode]
For the ECB mode and STN mode liquid crystal display devices, the polarizing plate of the present invention can be provided in the same manner as described above.

  Further, by combining with a λ / 4 plate, it can be used to reduce reflected light from the surface and the inside as a polarizing plate for reflective liquid crystal or a surface protective plate for organic EL display.

  The present invention will be illustrated below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 and Comparative Examples 1-2
<Preparation of antireflection film (AF)>
[Preparation of coating solution for hard coat layer]
750.0 parts by mass of trimethylolpropane triacrylate [“TMPTA” manufactured by Nippon Kayaku Co., Ltd.], 270.0 parts by mass of poly (glycidyl methacrylate) having a mass average molecular weight of 3000, 730.0 parts by mass of methyl ethyl ketone, 500. 0 parts by mass and 50.0 parts by mass of a photopolymerization initiator “Irgacure 184” (manufactured by Ciba Geigy Japan, Inc.) were added and stirred. The solution was filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution for a hard coat layer.

[Preparation of titanium dioxide fine particle dispersion A]
As the titanium dioxide fine particles, titanium dioxide fine particles ["MPT-129" manufactured by Ishihara Sangyo Co., Ltd.] containing cobalt and surface-treated with aluminum hydroxide and zirconium hydroxide were used.
The following dispersant (38.6 parts by mass) and cyclohexanone (704.3 parts by mass) were added to 257.1 parts by mass of the particles and dispersed by dynomill to prepare a titanium dioxide dispersion A having a mass average diameter of 70 nm.

[Preparation of coating solution for medium refractive index layer]
To 88.9 parts by mass of the above titanium dioxide dispersion, 58.4 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA), 3.1 parts by mass of a photopolymerization initiator “Irgacure 907”, light Sensitizer “Kayacure DETX” [manufactured by Nippon Kayaku Co., Ltd.] 1.1 parts by mass, 482.4 parts by mass of methyl ethyl ketone, and 1869.8 parts by mass of cyclohexanone were added and stirred. After sufficiently stirring, the solution was filtered through a polypropylene filter having a pore diameter of 0.4 μm to prepare a coating solution for a medium refractive index layer.

[Preparation of coating solution for high refractive index layer]
Titanium dioxide dispersion A: 586.8 parts by mass, DPHA 47.9 parts by mass, Irgacure 907: 4.0 parts by mass, “Kayacure DETX” 1.3 parts by mass, methyl ethyl ketone 455.8 parts by mass, and cyclohexanone 1427.8 parts by mass were added and stirred. The solution was filtered through a polypropylene filter having a pore diameter of 0.4 μm to prepare a coating solution for a high refractive index layer.

[Preparation of coating solution for low refractive index layer]
DPHA, 1.4 parts by mass, 5.6 parts by mass of fluororesin (PF-1) having the following structure, hollow silica as hollow particles (average particle size 40 nm, shell layer thickness 7 nm, refractive index 1.31, isopropanol 18 masses) %) 20.0 parts by mass, reactive silicone “RMS-033” (manufactured by Gelest) 0.7 part by mass, 6.2 parts by mass of sol liquid a having the following contents, and 0.2 part by mass of Irgacure 907 The mixture was added to 9 parts by mass and stirred. The solution was filtered through a polypropylene filter having a pore diameter of 1 μm to prepare a coating solution for a low refractive index layer.

[Preparation of Sol Solution a]
A stirrer, a reactor equipped with a reflux condenser, 120 parts of methyl ethyl ketone, 100 parts of acryloyloxypropyltrimethoxysilane ["KBM5103" manufactured by Shin-Etsu Chemical Co., Ltd.], 3 parts of diisopropoxyaluminum ethyl acetoacetate are added and mixed. Further, 30 parts of ion-exchanged water was added and reacted at 60 ° C. for 4 hours, and then cooled to room temperature to obtain a sol solution a. The mass average molecular weight was 1600, and among the components higher than the oligomer component, the component having a molecular weight of 1000 to 20000 was 100%. From the gas chromatography analysis, no acryloyloxypropyltrimethoxysilane as a raw material remained.

[Preparation of antireflection film (AF-1)]
A hard coat layer coating solution was coated on a cellulose triacetate [“TAC-TD80U” manufactured by Fuji Photo Film Co., Ltd .: refractive index 1.48] having a thickness of 80 μm using a gravure coater. After drying at 100 ° C. and using a 160 W / cm air-cooled metal halide lamp [manufactured by Eye Graphics Co., Ltd.] while purging with nitrogen so that the atmosphere has an oxygen concentration of 1.0% by volume or less, an illuminance of 400 mW / The coating layer was cured by irradiating with ultraviolet rays of cm ² and an irradiation amount of 300 mJ / cm ² to form a hard coat layer having a thickness of 8 μm. On the obtained hard coat layer, a medium refractive index layer coating solution and a high refractive index layer coating solution were successively applied using a gravure coater having three coating stations.

The medium refractive index layer was dried at 100 ° C. for 2 minutes, and the ultraviolet curing condition was an air-cooled metal halide lamp [I Graphics, which was purged with nitrogen so that the atmosphere had an oxygen concentration of 1.0% by volume or less. Made by Co., Ltd.], and the irradiation amount was 400 mW / cm ² and the irradiation amount was 400 mJ / cm ² . The medium refractive index layer after curing had a refractive index of 1.630 and a film thickness of 67 nm.

The drying conditions for the high refractive index layer were 90 ° C., 1 minute, 100 ° C., 1 minute, and the ultraviolet curing conditions were carried out with nitrogen purge so that the atmosphere had an oxygen concentration of 1.0% by volume or less. Using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 240 W / cm, the irradiation dose was 600 mW / cm ² and the irradiation dose was 600 mJ / cm ² . The cured high refractive index layer had a refractive index of 1.905 and a film thickness of 107 nm.

Using the microgravure roll with a diameter of 50 mm and a doctor blade having a gravure pattern with a line number of 180 lines / inch and a depth of 40 μm on the high refractive index layer, the coating liquid for the low refractive index layer is rotated. After applying at 30 rpm and a transfer speed of 15 m / min, drying at 120 ° C. for 150 seconds, and further drying at 140 ° C. for 8 minutes, an air-cooled metal halide lamp of 240 W / cm under a nitrogen purge [I Graphics, Inc. )] Is used to irradiate ultraviolet rays having an illuminance of 400 mW / cm ² and an irradiation amount of 900 mJ / cm ² to form a low refractive index layer (AL-1) having a thickness of 100 nm, and an antireflection film (AF-1) It was created.

[Preparation of comparative antireflection film (AFR)]
In the antireflection film (AF-1) of Example 1, the low refractive index layers (ALR-1) to (ALR-3) were formed by changing the hollow particles of the low refractive index layer as shown in Table 1 below. Were produced in the same manner as in Example 1, and antireflection films (AFR-1) to (AFR-3) of Comparative Examples 1-1 to 1-3 were produced.

[Evaluation of antireflection film]
The obtained antireflection film was evaluated for the following contents, and the results are shown in Table 2.

(Haze)
Haze was measured using a haze meter [1001DP type, manufactured by Nippon Denshoku Industries Co., Ltd.]. Five points were measured per film sample, and the average value was adopted.

(Average reflectance)
The spectrophotometer “V-550” (manufactured by JASCO Corporation) is equipped with an adapter “ARV-474” and has a specular reflectance of an output angle of −5 ° at an incident angle of 5 ° in the wavelength region of 380 to 780 nm. Was measured, an average reflectance of 450 to 650 nm was calculated, and antireflection properties were evaluated.

(Surface energy)
As an index of surface contamination resistance (fingerprint adhesion), the optical material was conditioned at a temperature of 25 ° C. and 60% RH for 2 hours, and then measured by the method described above.

(Dynamic friction coefficient)
The dynamic friction coefficient was evaluated as an index of surface slipperiness. The coefficient of dynamic friction is 5 mmφ stainless steel ball, load 100 g, speed 60 cm with a “HEIDON-14” dynamic friction measuring machine (manufactured by Shinto Kagaku Co., Ltd.) after conditioning the sample for 2 hours at 25 ° C. and 60% RH. The value measured at / min was used.

(Clarity)
The sample was sandwiched between two polarizing plates arranged in crossed Nichols, and the unevenness of transmitted light was visually observed for sensory evaluation.
○: Not generated at all (level that 10 people evaluate and one cannot recognize)
Δ: Weak occurrence (level evaluated by 10 people and recognized by 1 to 5 people)
X: Strongly generated (level evaluated by 10 people and recognized by 6 or more people)

(Uniformity of color)
The spectrophotometer “V-550” (manufactured by JASCO Corporation) is equipped with an adapter “ARV-474” and has a specular reflectance of an output angle of −5 ° at an incident angle of 5 ° in the wavelength region of 380 to 780 nm. was measured, from the measured reflectance spectrum of 450 to 650 nm, L ^* value of the CIE1976L ^* a ^* b ^* color space representing the color of specular reflection light with respect to 5 ° incident light CIE standard light source D _65, a ^* value , B ^* values were calculated and the color of the reflected light was evaluated.

The film was 1 m in the length direction, and the measurement points were the length in the roll form, the center in the width direction, and three points at each end. The film sample used the front-end | tip part of the coating roll, the center part, and the terminal part. Each value was the median value of the above measurement points, and the fluctuation range was expressed as a percentage calculated by dividing the difference between the maximum value and the minimum value by the median value. The following four grades were evaluated.
○: Change rate is 10% or less △: Change rate exceeds 10% to less than 20% ×: Change rate is 21% or more

  The antireflection film (AF-1) corresponding to Example 1 of the present invention had a low reflectivity, a small surface energy on the film surface, and excellent water repellency. In addition, the sharpness and color of the displayed image were close to neutral, and the uniformity was also good. The antireflection film (AFR-1) for comparison deteriorated the sharpness of the image. The anti-reflection film (AFR-2) for comparison deteriorated the sharpness and color of the image. The comparative antireflection film (AFR-3) was insufficient in both image clarity and color.

[Surface treatment of antireflection film (AF)]
A dielectric heating roll at a temperature of 60 ° C. is passed over the cellulose triacetate film surface on the opposite side of the antireflection film of the antireflection films (AF-1) and (AFR-1) to (AFR-3), After the film surface temperature was raised to 40 ° C., an alkaline solution (S-1) having the composition shown below was applied at a coating amount of 12 cc / m ² using a rod coater and heated to 110 ° C. Noritake Co., Ltd. After being allowed to stay for 15 seconds under a steam far-infrared heater manufactured by Limited, pure water was applied at 3 cc / m ² using a rod coater. The film temperature at this time was 40 degreeC. Next, washing with a fountain coater and draining with an air knife were repeated three times, and then the film was retained in a drying zone at 70 ° C. for 5 seconds and dried.

-Alkaline solution (S-1) composition Potassium hydroxide 8.55 mass%
23.235% by weight of water
Isopropanol 54.20% by mass
Surfactant 1.0% by mass
_{K-1: C 14 H 29} O (CH 2 CH 2 O) 20 H
Propylene glycol 13.0% by mass
Defoamer 0.015% by mass
“Surfinol DF110D”: manufactured by Nissin Chemical Industry Co., Ltd.

  The contact angle with water of the saponified surface of each obtained film was 34 to 35 °, and the surface energy was 62 to 63 mN / m.

<Preparation of polarizing plate with antireflection film>
[Polarizing film (H-1) and polarizing plate (P-1) of the present invention]
A PVA film having an average degree of polymerization of 2400 and a film thickness of 105 μm was pre-swelled with ion exchange water at 40 ° C. for 60 seconds, and after scraping the surface moisture with a stainless steel blade, 0.7 g / L of iodine, iodine It was immersed for 55 seconds at 40 ° C. in an aqueous solution of potassium halide 60.0 g / L and boric acid 5.0 g / L while correcting the concentration to be constant. Further, boric acid 42.5 g / L, iodine After immersing in an aqueous solution of potassium halide 30 g / L for 90 seconds at 40 ° C. while correcting the concentration, the excess water was scraped off with a stainless steel blade on both sides of the film. Was introduced into a tenter drawing machine. After feeding 100m at a conveyance speed of 4m / min and stretching up to 5 times in an atmosphere of 60 ° C and 95% RH, the tenter is bent in the stretching direction as shown in Fig. 1, and then the width is kept constant and contracted. However, after drying in an atmosphere at 70 ° C., the film was detached from the tenter to produce a polarizing film (H-1). At this time, the polarizing film (H-1) had a thickness of 19 μm and a water content of 2.5% by mass.

  The fluctuations in temperature and humidity during stretching during the preparation of the polarizing film were such that the temperature was 55 ± 0.2 ° C. and the humidity was 95% ± 1% RH. The moisture content of the PVA film before starting stretching was 32% by volume, and the moisture content after drying was 2.5% by mass.

  The difference in transport speed between the left and right tenter clips (holding means) of the PVA film is less than 0.05%, and the angle between the center line of the introduced film and the center line of the film sent to the next process is 46 °. there were. Here, | L1-L2 | is 0.7 m, W is 0.7 m, and | L1-L2 | = W. The substantial stretching direction Ax-Cx at the tenter outlet was inclined by 45 ° with respect to the center line 22 of the film sent to the next process. Wrinkles, film deformation, and stretching unevenness at the tenter exit were not observed.

Then, 3 cm from the width direction, the ear was cut with a cutter, and then the reflection was applied to one surface of the polarizing film using a 3% by mass aqueous solution of PVA [“PVA-124H” manufactured by Kuraray Co., Ltd.] as an adhesive. The cellulose acylate film surface of the cellulose acylate film coated with the anti-reflective coating (AF-1) is bonded to the surface of the cellulose acylate film that has not been coated with the anti-reflective coating, and the anti-reflective coating is applied to the other surface of the polarizing film. One side of the same cellulose triacetate film used for film formation is bonded to the same saponified film side as above, and further heated at 70 ° C. for 10 minutes, with an antireflection film in the form of a roll having an effective width of 650 mm and a length of 100 m A polarizing plate (P-1) was produced.
The absorption axis direction of the obtained polarizing plate was inclined 45 ° with respect to the longitudinal direction.

[Comparative Polarizing Film (HR-1) and Comparative Polarizing Plate (PR-1)]
A PVA film having an average degree of polymerization of 2400 and a film thickness of 132 μm was pre-swelled with ion exchange water at 15 ° C. for 48 seconds, and after scraping the surface moisture with a stainless steel blade, 0.9 g / L iodine, It was immersed in an aqueous solution of potassium iodide 60.0 g / L for 55 seconds at 40 ° C. while correcting the concentration so that the concentration was constant, and further, boric acid 42.5 g / L and potassium iodide 30 g / L in an aqueous solution. After immersing for 90 seconds at 40 ° C. while correcting the concentration so that the concentration was constant, excess water was scraped off on both surfaces of the film with a stainless steel blade and introduced into a tenter stretching machine in the form of FIG. After feeding 100m at a conveyance speed of 4m / min and stretching up to 4.12 times at 60 ° C in a 95% atmosphere, the tenter is bent in the stretching direction as shown in Fig. 1, and then the width is kept constant and contracted. Then, after drying in an atmosphere at 75 ° C., the film was separated from the tenter to produce a comparative polarizing film (HR-1). At this time, the polarizing film had a thickness of 29 μm and a moisture content of 2.5% by mass. The stretching process was performed under the same conditions as in Example 1.

  Then, after cutting the edge with a cutter 3 cm from the width direction, Fuji Photo Film (saponified as described above) using a 3% by weight aqueous solution of PVA [“PVA-124H” manufactured by Kuraray Co., Ltd.] as an adhesive ( Bonded with “Fujitac” (cellulose triacetate, in-plane retardation value 3.0 nm, film thickness 80 μm) manufactured by Co., Ltd., and further heated at 70 ° C. for 10 minutes to compare rolls having an effective width of 650 mm and a length of 100 m A polarizing plate PR-1 was produced.

  About this polarizing film (H), the single plate transmittance | permeability and the polarization degree were measured with Shimadzu self-recording spectrophotometer "UV3100".

The degree of polarization is defined as follows. The transmittance when two polarizing plates are overlapped with the absorption axes being coincident is H0 (%), and the transmittance when the absorption axes are overlapped is orthogonal is H1 (%). It calculated | required by Numerical formula (22).
Formula (22): Polarization degree P = [(H0−H1) / (H0 + H1)] ^1/2 × 100
The single plate transmittance and polarization degree were corrected for visibility, and the results are shown in Table 3.

Comparative Examples 2-1 to 2-3
[Other polarizing plate with antireflection film for comparison]
In the polarizing plate with antireflection film (P-1) of Example 1, any one of the antireflection films for comparison (AFR-1) to (AFR-3) is used instead of the antireflection film (AF-1). In the same manner as in Example 1, polarizing plates (PR-1) to (PR-3) with an antireflection film for comparison were produced. The combinations are shown in Table 4.

[Performance of polarizing plate with antireflection film]
About each obtained polarizing plate, the performance evaluation of the following content was performed and the result was described in Table 5.

(Pencil hardness evaluation)
The pencil hardness evaluation described in JIS K-5400 was performed as an index of scratch resistance. After conditioning the polarizing plate with an antireflection film at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, using a 3H test pencil specified in JIS S-6006, the antireflection film side was applied with a load of 1 kg. The surface was tested at five locations and visually evaluated according to the following criteria.
○: No scratches are observed at all points.
Δ: One or two scratches.
X: Three or more scratches.

(Adhesion)
The cellulose acylate film coated with the antireflection film was conditioned for 2 hours under the conditions of a temperature of 25 ° C. and a humidity of 60% RH. On the surface of the anti-reflection film of each anti-reflection film coated cellulose acylate film, a cutter knife is used to cut 11 squares and 11 horizontal cuts in a grid pattern to make a total of 100 square squares. The adhesion test on the polyester adhesive tape “NO.31B” manufactured by the same company was repeated three times at the same place. The presence or absence of peeling was visually observed, and the following four-stage evaluation was performed.
A: No peeling was observed at 100 mm.
○: No peeling was observed within 100 mm at 100 mm.
(Triangle | delta): The thing by which peeling was recognized in 100 tons is a thing of 10 to 3 tons.
X: The thing in which peeling was recognized in 100 tons exceeded 10 tons.

(Still wool wear resistance)
In the antireflection film before and after the exposure, a load of 500 g / cm ² was applied to # 0000 still wool, and the state of scratches when reciprocating 60 times was observed and evaluated in the following three stages.
A: There is no scratch.
B: Slightly scratched but difficult to see.
C: Scratches are remarkable.

(Specular reflectance and color uniformity)
The spectrophotometer “V-550” (manufactured by JASCO Corporation) is equipped with an adapter “ARV-474” and has a specular reflectance of an output angle of −5 ° at an incident angle of 5 ° in the wavelength region of 380 to 780 nm. was measured, from the measured reflectance spectrum of 450 to 650 nm, L ^* value of the CIE1976L ^* a ^* b ^* color space representing the color of specular reflection light with respect to 5 ° incident light CIE standard light source D _65, a ^* value B ^* value was calculated, and the color of reflected light was evaluated using the a ^* value and b ^* value.

  The measurement points of the film are 3 points from the length direction of the roll form (the front end portion, the central portion and the end portion of the roll after coating), and a total of 9 points in the width direction (center and both ends) at each point. Measurements were made.

The average value of each of the a ^* value and b ^* value of each film was determined and used as the median value. The difference between the maximum value and the minimum value of each of the a ^* value and the b ^* value was determined, and the difference was divided by the median value and multiplied by 100 to obtain the color change rate. The rate of change was evaluated in four stages within the following range. The larger result of the change rates of the a ^* value and the b ^* value was used.
A: 0 to 8%
○: 8-20%
Δ: 20-30%
×: 30% or more

(Evaluation of weather resistance)
Using a sunshine weather meter [“S-80” manufactured by Suga Test Instruments Co., Ltd.], each level of weather resistance test was performed at a humidity of 50% RH and an exposure time of 200 hours.
For the sample after the weather resistance test, the specular reflectance and the reflection spectrum were measured in the same manner as described above, and the color of the reflected light of the CIE chromaticity diagram in the wavelength region of 380 nm to 780 nm was calculated. The change in the specular reflectance and the color change before and after the weather resistance test were determined by comparing the specular reflectance and the color of the sample. Regarding the change in color, the distance ΔE from the center point to the color point of each sample was measured on the chromaticity diagram, the difference in ΔE before and after the weather resistance test was determined, and the following four-level evaluation was performed.
(Reflective color change ΔE)
A: ΔE is 5 or less
○: ΔE is 5 to 10,
Δ: ΔE is 10 to 15,
×: ΔE is 15 or more

(Change rate of light transmittance and polarization degree)
The antireflection film-attached polarizing plate was aged in an atmosphere of 60 ° C. and 90% RH (for 500 hours), and changes in light transmittance and polarization degree were examined in comparison with a sample before the aging.
Rate of change (%) = [(Numerical value before aging−Numerical value after aging) / Numerical value before aging] × 100
The degree of change was determined according to the following criteria.
Light change rate Polarization degree change rate ◎: Less than 2% Less than 1% ○: 2% or more and less than 3% 1% or more and less than 3% ×: 3% or more 3% or more

(Dimensional change rate)
The polarizing plate with an antireflection film was cut into a size of 50 mm × 50 mm and heated at a temperature of 70 ° C. for 120 hours. The dimension (Lb) before the heating test of the test piece and the dimension (La) after the heating test were measured in the absorption axis (MD) direction and the polarization axis (TD) direction, and the dimensional change rate (%) from the following equation: Asked.
Dimensional change rate = [(La−Lb) / Lb] × 100

  The polarizing plate with the antireflection film of Example 1 showed good performance in all of the mechanical characteristics, optical characteristics, and durability of the film. In the samples of Comparative Examples 2-1 to 2-3, the mechanical properties and antireflection performance of the film were deteriorated.

Example 11
<Liquid crystal display device>
[Viewing side polarizing plate]
Optical compensation in which the disc surface of the discotic structural unit is inclined with respect to the support surface, and the angle formed by the disc surface of the discotic structural unit and the support surface changes in the depth direction of the optical anisotropic layer In the optical compensation film having a layer [Wide View Film A 12B, manufactured by Fuji Photo Film Co., Ltd.], the surface opposite to the side having the optical compensation layer was saponified under the same conditions as the alkali saponification treatment.

  The surface of the cellulose triacetate film opposite to the antireflection film of the polarizing plate with the antireflection film was subjected to alkali saponification treatment in the same manner. Using a polyvinyl alcohol-based adhesive as an adhesive, the saponified cellulose triacetate film surfaces of the optical compensation film and the polarizing plate with the antireflection film were bonded together. In this way, a viewing side polarizing plate (SHB-1) was produced.

[Lower polarizing plate]
A cellulose triacetate film “Fujitac TAC-TD80U” was used as a protective film on both sides of the polarizing film (H-1), and one side thereof was subjected to alkali saponification treatment in the same manner as described above. A laminated polarizing plate was prepared using a polyvinyl adhesive in 1). Next, the surface of the cellulose triacetate film on one side of the polarizing plate and the surface opposite to the side having the optical compensation layer of the optical compensation film “Wide View Film A 12B” were similarly subjected to alkali saponification treatment. Each saponified surface was bonded together using a polyvinyl alcohol-based adhesive as an adhesive. In this manner, a lower polarizing plate (BHB-1) was produced.

[TN mode liquid crystal display]
TN mode 20-inch liquid crystal display: TH-20TA3 type [manufactured by Matsushita Electric Co., Ltd.] Instead of the viewing-side polarizing plate, the optical of the viewing-side polarizing plate (SHB-1) of the present invention One sheet was affixed to the observer side via an acrylic pressure-sensitive adhesive so that the anisotropic layer was on the liquid crystal cell side. The lower polarizing plate (BHB-1) was attached to the backlight side via an adhesive so that the optically anisotropic layer side was the liquid crystal cell side. The transmission axis of the polarizing plate on the observer side and the transmission axis of the polarizing plate on the backlight side were arranged so as to be in the O mode.

Comparative Examples 11-1 to 11-3
In Example 11, instead of using the viewing side polarizing plate (SHB-1) of the polarizing plate with antireflection film (P-1) of the present invention as the viewing side polarizing plate, a polarizing plate with antireflection film for comparison (PR) -1) to (PR-3) A TN mode liquid crystal display device is manufactured in the same manner as in Example 11 except that any one of the viewing side polarizing plates (SHB-R1) to (SHB-R3) is used. Produced.

[Drawing performance of liquid crystal display]
About each said liquid crystal display device, the image drawing property of the following contents was evaluated. The results are shown in Table 6.

(Evaluation of unevenness in drawn images)
Using a measuring device (“EZ-Contrast 160D” manufactured by ELDIM), the drawing unevenness during black display (L1) was visually observed.
○: Not generated at all (level that 10 people evaluate and one cannot recognize)
Δ: Weak occurrence (level evaluated by 10 people and recognized by 1 to 5 people)
X: Strongly generated (level evaluated by 10 people and recognized by 6 or more people)

(External light reflection evaluation)
The reflection of external light was evaluated using a fluorescent lamp, and the following four-level evaluation was performed visually.
◎: Reflection change, but not interested at all ○: Reflection change, but almost no concern △: Reflection change is acceptable, but acceptable ×: Reflection change is anxious

(Evaluation of black display color)
About a liquid crystal display device, the color change at the time of black display (L1) was visually observed using the measuring machine ("EZ-Contrast 160D" ELDIM company make).
◎: Not recognized at all (level that 10 people evaluate and no one can recognize)
○: Slightly recognized (level evaluated by 10 people and recognized by 1 to 2 people)
Δ: Weakly recognized (level evaluated by 10 people and recognized by 3-5 people)
X: Strongly generated (level evaluated by 10 people and recognized by 6 or more people)

(Contrast and viewing angle)
A white display voltage of 2 V and a black display voltage of 6 V are applied to the liquid crystal cell of the liquid crystal display device, and using a measuring instrument (“EZ-Contrast 160D” manufactured by ELDIM), the contrast ratio and the horizontal direction (perpendicular to the rubbing direction of the cell) Direction) viewing angle (the width of the angle range in which the contrast ratio is 10 or more).
◎: I don't care at all ○: There is a change, but I'm almost not interested

(Color change)
Using a device similar to the method for evaluating (contrast, viewing angle), the degree of change in color tone was visually observed when the viewing angle was in the range of 60 ° from the front, and evaluated according to the following criteria.
◎: I don't care at all ○: There is a change, but I'm almost not interested

  For each of the display devices of Example 11 and Comparative Examples 11-1 to 11-3, the image quality of the drawn image was evaluated according to the above method. The results are shown in Table 6.

In Example 11 of the present invention, the entire display image was good with no unevenness in drawing performance, and a bright image with good neutrality with small color tone and color tone change was displayed. In Comparative Example 11-1, external light reflection was reduced and the contrast was insufficient. In Comparative Example 11-2 and Comparative Example 11-3, image unevenness, external light reflection, contrast, color change, and the like were reduced. In addition, uneven brightness occurred and the uniformity of the drawn image was insufficient.
As described above, only the present invention is excellent in drawing a bright and clear display image.

Examples 12-13
In Example 1 and Example 11, instead of the low refractive index layer (AL-1) of the antireflection film of the polarizing plate with antireflection film (P-1), a low refractive index layer having the following contents was used. In the same manner as in Example 1, polarizing plates (P-2) to (P-3) with an antireflection film were produced. Next, each of these polarizing plates (P) was used as a viewing side polarizing plate in the same manner as in Example 11 and attached to the liquid crystal display device. Table 7 shows the correspondence table.

[Low refractive index layer]
(Low refractive index layer AL-2)
Thermally crosslinkable fluorine-containing polymer having a refractive index of 1.42 [“JTA113”, solid content concentration 6%, manufactured by JSR Corporation] 130 parts by mass, silica sol [silica: “MEK-ST”, average particle size 15 nm, solid content Concentration 30%, manufactured by Nissan Chemical Co., Ltd.] 5 parts by mass, hollow silica [“CS60-IPA”, average particle size 60 nm, shell layer thickness 10 nm, refractive index 1.31, isopropanol 20% by mass dispersion, catalyst conversion ( Co., Ltd.] 15 parts by mass, 6 parts by mass of the above sol a, 50 parts by mass of methyl ethyl ketone, and 60 parts by mass of cyclohexanone were added, stirred, and then filtered through a polypropylene filter having a pore size of 1 μm. A coating solution for AL-2) was prepared. Using this coating solution, a low refractive index cured film having a thickness of 100 nm was formed in the same manner as in the coating conditions of Example 1, and a polarizing plate (P-2) with an antireflection film was further produced.
The surface of the antireflection film of the obtained antireflection polarizing plate had a surface energy of 21 mN / m and a dynamic friction coefficient of 0.12.

(Low refractive index layer AL-3)
Thermally crosslinkable fluorine-containing polymer having a refractive index of 1.42 [“JN-7228”, solid content concentration 6%, manufactured by JSR Corporation] 150 parts by mass, DHPMA 3.5 parts by mass, silica sol “MEK-ST” 5 parts by mass Part, hollow silica “CS60-IPA” 15 parts by mass, sol liquid a 6 parts by mass, reactive silicone “X22-164C” 3 parts by mass, methyl ethyl ketone 50 parts by mass, and cyclohexanone 60 parts by mass The solution was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a low refractive index layer (AL-3). Using this coating solution, a low refractive index cured film having a thickness of 100 nm was formed in the same manner as in the coating conditions of Example 1, and a polarizing plate (P-3) with an antireflection film was further produced.
The surface of the antireflection film of the obtained polarizing plate with the antireflection film had a surface energy of 20 mN / m and a dynamic friction coefficient of 0.11.

[Viewing side polarizing plate]
In the viewing-side polarizing plate (SHB-1) of Example 11, each of the above polarizing plates with antireflection film (P-2) or (P-3) instead of the polarizing plate with antireflection film (P-1) The viewing side polarizing plate (SHB-2) and (SHB-3) were produced like Example 11 except having used.

[OCB mode liquid crystal display]
A polyimide film was provided as an alignment film on a glass substrate with an ITO electrode, and the alignment film was rubbed. The obtained two glass substrates were faced to each other so that the rubbing directions were parallel to each other, and the cell gap was set to 6 μm. A liquid crystal compound having a Δn of 0.1396 (“ZLI1132” manufactured by Merck) was injected into the cell gap to produce a bend-aligned liquid crystal cell. A polarizing plate (SHB-2) or (SHB-3) was pasted on the viewing side of the cell via an adhesive so that the optical compensation sheet was on the liquid crystal cell side so as to sandwich the produced bend alignment cell. . Further, a backlight side polarizing plate (BHB-1) was attached to the backlight side through an adhesive so that the optically anisotropic layer side was the liquid crystal cell side. The transmission axis of the polarizing plate on the viewing side and the transmission axis of the polarizing plate on the backlight side were arranged to be in the O mode.

  Regarding Examples 12 and 13, each performance was examined in the same manner as Example 11. Both showed good performance equivalent to Example 11.

Example 14
[Preparation of transparent protective film]
(Preparation of fine particle dispersion (RL-1))
A mixture having the following composition and zirconia beads having a bead diameter of 0.2 mm were charged by a dynomill disperser and wet-dispersed to achieve a volume average particle diameter of 55 nm. Beads were separated from the obtained dispersion with a 200-mesh nylon cloth to prepare a fine particle dispersion (RL-1). When the particle size distribution of the obtained fine particle dispersion was measured, the number of particles having a particle size of 300 nm or more was 0%.
Here, the volume average particle diameter was measured with “particle size distribution measuring apparatus LA920 (manufactured by Horiba Seisakusho)”.

-Composition of fine particle dispersion (RL-1) Hydrophobic silica 2.00 parts by mass Product name “AEROSIL R812”
Modified methyl group, primary particle size 7 nm: Nippon Aerosil Co., Ltd.
Cellulose triacetate 2.00 parts by weight Substitution degree 2.85 (6-position substitution degree 0.90)
Dispersant (DP-1) 0.25 parts by mass Methylene chloride 78.70 parts by mass Methanol 14.20 parts by mass 1-butanol 2.86 parts by mass

(Preparation of cellulose acylate solution (A-1))
A mixture having the following composition was dissolved by stirring to prepare a cellulose acylate solution (A-1).

Cellulose acylate solution (A-1) composition Cellulose acetate propionate 100 parts by mass Substitution degree 2.70 (acetate / propionate ratio 1 / 0.4)
Plasticizer A (logP4.18) having the following structure 7.1 parts by mass Plasticizer B having the following structure (logP1.88) 3.6 parts by mass Plasticizer C having the following structure (logP3.73) 3.6 parts by mass UV agent: UV-1 0.5 part by mass The following UV agent: UV-2 0.7 part by mass Methylene chloride 300 parts by mass Methanol 54 parts by mass 1-butanol 11 parts by mass

(Preparation of dope)
15.3 parts by mass of the fine particle dispersion (RL-1) was added to 474 parts by mass of the cellulose acylate solution (A-1) while stirring. The resulting heterogeneous gel-like solution was cooled at -70 ° C for 6 hours and then heated to 50 ° C and stirred to obtain a completely dissolved dope.
Next, the obtained dope was filtered with a filter paper having an absolute filtration accuracy of 0.01 mm (manufactured by Toyo Filter Paper Co., Ltd., # 63) at 50 ° C., and further a filter paper having an absolute filtration accuracy of 0.0025 mm (FH025, manufactured by Pole Corporation). The dope was prepared by performing filtration and defoaming in (1).

(Solution casting method)
The step of preparing the cellulose acylate solution was performed as described above, and the obtained dope was cast using a band casting machine to form a cellulose acylate film from the cellulose acylate solution. .

A metal support (casting band) made of stainless steel and having a width of 2 m and a length of 56 m (area 112 m ² ) was used. The arithmetic average roughness (Ra) of the metal support was 0.006 μm, the maximum height (Ry) was 0.06 μm, and the ten-point average roughness (Rz) was 0.009 μm. The arithmetic average roughness (Ra), maximum height (Ry), and ten-point average roughness (Rz) were measured according to JIS B 0601.

The cast dope was dried at a wind speed of 0.5 m / s or less for 1 second immediately after casting, and thereafter dried at a wind speed of 15 m / s. The temperature of the drying air was 50 ° C.
When the film was peeled off from the casting band, the residual solvent amount of the film was 230% by mass, and the film temperature was −6 ° C. The average drying speed from casting to peeling was 745% by mass / min. Further, the gelation temperature of the dope at the time of stripping was about 10 ° C.

After the film surface temperature on the metal support reached 40 ° C., the film was dried for 1 minute and stripped, and then the temperature of the drying air was set to 120 ° C. At this time, the temperature distribution in the width direction of the film is 5 ° C. or less, the average wind speed of drying is 5 m / s, the average value of the heat transfer coefficient is 25 kcal / m ² · Hr · ° C., and the distribution in the width direction of the film is All were within 5%. Also, the pin tenter supporting portion in the drying zone was prevented from being directly exposed to the hot dry air by a wind shield.

  Next, the process of extending | stretching a cellulose acylate film was performed. That is, in the state of a film having a residual solvent amount of 15% by mass, the film was stretched transversely at a stretching ratio of 25% using a tenter under the condition of 130 ° C., and held at 50 ° C. for 30 seconds with the stretched width maintained. Was removed and wound up. The solvent evaporated between stripping and winding was 97% by mass of the initial amount of solvent. In the drying process, the dried film is further dried while being conveyed by a roller. After drying with a drying air of 145 ° C., the humidity and temperature are adjusted, and the residual solvent amount at the time of winding is 0.32% by mass, the moisture amount The product was wound up at 0.6% by mass to produce a cellulose acylate film (CA-1) (length 3500 m, width 1300 mm, thickness 80 μm, refractive index 1.48) as a transparent protective film. The fluctuation range of the film thickness was ± 2.4%. The curl value in the width direction was -0.2 / m.

[Uneven shape on the film surface]
The surface shape of the band side surface of the obtained cellulose acylate film was measured. The results are shown in Table 1. Table 8 also shows the results of evaluating the following optical characteristics and mechanical characteristics.

[Optical properties of film]
(Haze)
Haze was measured using a haze meter [1001DP type, manufactured by Nippon Denshoku Industries Co., Ltd.]. Five points were measured per film sample, and the average value was adopted.

[Method for evaluating mechanical properties]
(curl)
The curl value was measured according to a measurement method (ANSI / ASCPH1.29-1985, Method-A) defined by the American National Standards Institute. The polymer film was cut into a size of 35 mm in the width direction and 2 mm in the longitudinal direction, and then placed on a curl plate. The curl value was read after humidity conditioning for 1 hour in an environment of temperature 25 ° C. and humidity 65% RH. Similarly, the polymer film was cut into a size of 2 mm in the width direction and 35 mm in the longitudinal direction, and then placed on a curl plate. The curl value was read after humidity conditioning for 1 hour in an environment of temperature 25 ° C. and humidity 65% RH. Measurement was made in two directions, the width direction and the longitudinal direction, and the larger value of both values was taken as the curl value. The curl value is represented by the reciprocal of the radius of curvature (m).

(Tear strength)
The film was cut into a width of 65 mm and a length of 50 mm to prepare a sample. This sample was conditioned for 2 hours or more in a room at a temperature of 30 ° C. and a humidity of 85% RH, and in accordance with the standard of ISO 6383 / 2-1983, using a light load tear strength tester manufactured by Toyo Seiki Seisakusho, the load required for tearing ( g) was determined.

[Film properties]
(Optical defect)
The film was cut into a width of 1300 mm and a length of 5 m to prepare a sample. Two polarizing plates were placed in crossed Nicols, and this sample was placed between them to evaluate luminance defects by visual observation. The number of bright spots having a size of 100 μm or more was measured and expressed as a converted value per meter.

(Moisture permeability)
Based on JIS standard JIS Z-0208, measurement was performed under conditions of a temperature of 60 ° C. and a humidity of 95% RH, and the film thickness was converted to 80 μm.

[Preparation of antireflection film (AF-4)]
On the above cellulose acylate film (CA-1), “Pernox C-4456-S7” [hard coat agent in which ATO is dispersed (solid content: 45 mass%): manufactured by Nippon Pernox Co., Ltd.] is applied and dried. Then, it hardened | cured by irradiating an ultraviolet-ray and formed the 1-micrometer-thick electroconductive layer. The film had a surface resistance of the order of 10 ⁸ Ω / □.
The surface resistivity was measured using a resistivity meter “MCP-HT260” manufactured by Mitsubishi Chemical Corporation under the same condition after leaving the sample to stand under the condition of (25 ° C./65% RH) for 1 hour. .
On this, an antireflection film (AF-4) was produced as follows.

(Anti-glare hard coat layer coating solution)
Pentaerythritol triacrylate / pentaerythritol tetraacrylate mixture “PETA” [manufactured by Nippon Explosives Co., Ltd.] 50 parts by mass, curing initiator (Ciba Geigy, “Irgacure 184”) 2 parts by mass, first translucent particles As acryl-styrene beads [manufactured by Soken Chemical Co., Ltd., particle size 3.5 μm, refractive index 1.55] 5 parts by mass, as the second translucent fine particles, styrene beads [manufactured by Soken Chemical Co., Ltd., grains Diameter 3.5 μm, refractive index 1.60] 5.2 parts by mass, silane coupling agent “KBM-5103” [manufactured by Shin-Etsu Chemical Co., Ltd.] 10 parts by mass and the following fluoropolymer (PF-2) 0 0.03 parts by mass with 50 parts by mass of toluene to prepare a coating solution, and unwind the cellulose acylate film with a conductive layer in the form of a roll. The coating solution was applied so as to have a dry film thickness of 6.0 μm, and after solvent drying, an irradiance of 400 mW / cm ² and an irradiation amount of 300 mJ were used using a 160 W / cm air-cooled metal halide lamp [manufactured by Eye Graphics Co., Ltd.]. The coating layer was cured by irradiating with / cm ² of ultraviolet rays to prepare an antiglare hard coat layer (layer refractive index: 1.62).

(Preparation of antireflection film (AF-4))
On the antiglare layer, the coating liquid for the low refractive index layer (AL-1) was applied using a micro gravure coater. After drying at 80 ° C. and using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) while purging with nitrogen so that the oxygen concentration becomes 1.0 vol% or less, the illuminance is 550 mW / A low refractive index layer (refractive index: 1.43, film thickness: 86 nm) was formed by irradiating ultraviolet rays with a cm ² and an irradiation amount of 600 mJ / cm ² . Thus, the antireflection film (AF-4) of the present invention was produced. The obtained antireflection film had an average reflectance of 2.1% and a haze of 43%.
The performance described in Example 1 relating to mechanical properties and durability was evaluated in the same manner as in Example 1. The sharpness and the uniformity of the color of the reflected light were as good as those of the antireflection film of Example 1.

(surface treatment)
A 2.0 mol / L sodium hydroxide aqueous solution was heated to a temperature of 55 ° C., and the antireflection film (AF-4) was immersed in this bath for 2 minutes. The cellulose acylate film surface on the opposite side of the protective film was subjected to a hydrophilic treatment.

[Optical compensation sheet]
On one side of the cellulose acylate film (CA-1), a 1.0 mol / L potassium hydroxide aqueous solution was applied with a # 3 bar, treated at a film surface temperature of 60 ° C. for 10 seconds, washed with water, Dried. The contact angle of the film surface with water was 35 ° and the surface energy was 66 mN / m.

[Formation of alignment film]
On this surface-treated film, an alignment film coating solution having the following composition was coated with a rod coater at a coating amount of 28 mL / m ² . Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 90 ° C. for 150 seconds.

Alignment film coating solution 20% by mass of the following modified polyvinyl alcohol
Citric acid 0.05% by mass
Glutaraldehyde 0.5% by mass
360% by mass of water
Methanol 120% by mass

(Rubbing treatment of alignment film surface)
Next, under the environmental conditions (25 ° C./45% RH), a rubbing treatment was performed in parallel to the transport direction with a rubbing roll in which a commercially available rubbing cloth was attached to the alignment film surface in the longitudinal direction of the film. .

(Formation of optically anisotropic layer)
On the alignment film, 41.01 parts by mass of a discotic liquid crystalline compound (DA) having the following structure, ethylene oxide-modified trimethylolpropane triacrylate [“V # 360”, manufactured by Osaka Organic Chemical Co., Ltd.] 4.06 parts by mass , 0.90 parts by mass of cellulose acetate butyrate (“CAB551-0.2”, Eastman Chemical Co.), 0.23 parts by mass of cellulose acetate butyrate (“CAB531-1”, Eastman Chemical Co.), light 1.35 parts by weight of a polymerization initiator (“Irgacure 907”, manufactured by Ciba Geigy), 0.45 parts by weight of a sensitizer [“Kayacure DETX”, manufactured by Nippon Kayaku Co., Ltd.], a fluorosurfactant having the following structure (PF-3) 0.40 part by mass was used as a solution and coating solution dissolved in 102 parts by mass of methyl ethyl ketone. It was coated with ya ba. This was heated in a constant temperature zone of 130 ° C. for 2 minutes to align the discotic liquid crystalline compound. Next, UV irradiation was performed for 1 minute using a 120 W / cm high-pressure mercury lamp in an atmosphere of 60 ° C. to polymerize the discotic liquid crystalline compound. Then, it stood to cool to room temperature. In this way, an optically anisotropic layer having a thickness of 2.0 μm was formed to produce an optical compensation sheet (WV-1).

(surface treatment)
The film surface opposite to the optically anisotropic layer of the obtained optical compensation sheet was saponified in the same manner as the one-side saponification treatment of the antireflection film.

[Polarizing film (H-2) and viewing side polarizing plate (SHB-4)]
A PVA film having an average degree of polymerization of 2400 and a film thickness of 75 μm is pre-swelled with ion exchange water at 40 ° C. for 60 seconds, and after scraping the surface moisture with a stainless steel blade, iodine 0.7 g / L, iodinated The PVA film was immersed in an aqueous solution of 60.0 g / L of potassium and 1 g / L of boric acid so that the concentration was kept constant, while being immersed for 55 seconds at 40 ° C., and further 42.5 g / L of boric acid and iodide Potassium 30 g / L, C.I. I. Direct Yellow 44 (λmax 410 nm) 0.1 g / L, C.I. I. Direct Blue 1 (λmax 650 nm) After immersing the PVA film for 90 seconds at 40 ° C. while correcting the concentration so that the concentration is constant in an aqueous solution of 0.1 g / L, excess water is removed on both sides of the film with a stainless steel blade. Scraping and transverse uniaxial stretching was performed using a tenter stretching machine. After conveying 100m at a conveyance speed of 4m / min, stretching to 4.12 times in an atmosphere of 60 ° C and 95% RH, and then drying in a 65 ° C atmosphere while keeping the width constant and shrinking, from the tenter The film was detached and a polarizing film (H-2) was obtained. The polarizing film had a thickness of 17.5 μm and a water content of 3% by mass.

  Then, after trimming with a cutter 3 cm from the width direction, 3% by weight aqueous solution of PVA (manufactured by Kuraray Co., Ltd., PVA-124H) as an adhesive, the above saponified antireflection film (AF-4) The saponification-treated surface and the saponification-treated surface of the above-mentioned saponified optical compensation sheet were bonded to each other, and further heated at 70 ° C. for 10 minutes, and the viewing-side polarizing plate (SHB) in a roll shape having an effective width of 650 mm and a length of 100 m -4) was produced.

[Liquid Crystal Display]
An optical anisotropic layer of the polarizing plate (SHB-4) of the present invention is used instead of the optical film provided in the IPS mode 20-inch liquid crystal display device: W20-lc3000 type [manufactured by Hitachi, Ltd.] One sheet was affixed to the viewing side through an acrylic pressure-sensitive adhesive so as to be on the liquid crystal cell side. On the lower side, the polarizing plate (BHB-1) was attached to the lower side through an acrylic adhesive so that the transparent protective film of the polarizing film was on the liquid crystal cell side.

[Drawing performance of liquid crystal display]
For the display device of Example 14, the image quality of the drawn image was evaluated in the same manner as in Example 11. The result was an image with good uniformity without glare, and showed good performance in all of the color tone, contrast, viewing angle, and color neutrality in black display.

Example 15
[Polarizing film (H-3) and viewing side polarizing plate (SHB-5)]
The viewing side polarizing plate (SHB) of Example 11 except that the following polarizing film (H-3) was used instead of the polarizing film (H-1) in the viewing side polarizing plate (SHB-1) in Example 11. The viewing-side polarizing plate (SHB-5) was produced in the same manner as in -1).

(Polarizing film (H-3))
A PVA film having an average degree of polymerization of 2400 and a film thickness of 75 μm is pre-swelled with ion exchange water at 40 ° C. for 60 seconds, and after scraping the surface moisture with a stainless steel blade, iodine 0.7 g / L, iodinated It was immersed in an aqueous solution of potassium 60.0 g / L and boric acid 1 g / L for 55 seconds at 40 ° C. while correcting the concentration to be constant, and further boric acid 42.5 g / L and potassium iodide 30 g. After immersing the PVA film for 90 seconds at 40 ° C. while correcting the concentration so that the concentration is constant in a / L aqueous solution, scrape excess water on both sides of the film with a stainless steel blade, and the tenter stretching in the form of FIG. Introduced into the machine. After feeding 100 m at a conveyance speed of 4 m / min and stretching up to 4.5 times in an atmosphere of 60 ° C. and 95% RH, the tenter is bent in the stretching direction as shown in FIG. After shrinking and drying in an atmosphere of 65 ° C., the film was detached from the tenter to obtain a polarizing film (H-3). At this time, the polarizing film had a thickness of 16 μm and a moisture content of 3% by mass.

  The variation of temperature and humidity during stretching during the preparation of the polarizing film was such that the temperature was 60 ± 0.1 ° C. and the humidity was 95% ± 0.5% RH. The moisture content of the PVA film before starting stretching was 33% by volume, and the moisture content after drying was 3% by mass.

The difference in transport speed between the left and right tenter clips was less than 0.05%, and the angle between the center line of the introduced film and the center line of the film sent to the next process was 47 °. Here, | L1-L2 | is 0.7 m, W is 0.7 m, and | L1-L2 | = W. The substantial stretching direction Ax-Cx at the tenter outlet was inclined by 45 ° with respect to the center line 22 of the film sent to the next process. Wrinkles, film deformation, and stretching unevenness at the tenter exit were not observed.
The absorption axis direction of the obtained polarizing plate was inclined 45 ° with respect to the longitudinal direction.

[Liquid Crystal Display]
Optical anisotropy of the polarizing plate (SHB-5) of the present invention instead of the polarizing plate on the viewing side provided in the 22-inch liquid crystal display device: TH22-LH10 type (manufactured by Matsushita Electric Co., Ltd.) in the VA mode One sheet was affixed to the viewer side via an acrylic pressure-sensitive adhesive so that the layer was on the liquid crystal cell side.

  Each performance of the obtained polarizing plate and display device was evaluated in the same manner as in Example 1. The results were as good as in Example 1.

Example 16
A λ / 4 plate is laminated on the transparent protective film on the side of the polarizing plate (P-1) with a single-side antireflection film prepared in Example 1 on which the antireflection film is not coated, and the surface of the organic EL display device When affixed to a glass plate, the surface reflection and the reflection from the inside of the surface glass were cut, and a display with extremely high visibility and good neutrality was obtained.

It is a schematic plan view which shows an example of the method of extending | stretching a polymer film diagonally.

Explanation of symbols

(A) Film introduction direction (b) Film transport direction to the next step (a) Step of introducing the film (b) Step of stretching the film (c) Step of sending the stretched film to the next step

A1 Position of biting into film holding means and starting point of film stretching (substantially holding start point: right)
B1 Biting position of film holding means (left)
C1 Film stretch starting position (substantially holding start point: left)
Cx film release position and film stretching end point reference position (actual holding release point: left)
Ay Film drawing end point reference position (substantially holding release point: right)
| L1-L2 | Stroke difference W between left and right film holding means W Substantially width θ at the end of the film stretching process Angle formed by the stretching direction and the film traveling direction

21 Center line 22 of introduction side film Center line 23 of film sent to the next process Track of film holding means (left)
24 Trajectory of film holding means (right)
25 Introducing film 26 Films 27 and 27 'sent to the next process Left and right film holding start (biting) points 28 and 28' Release points from the left and right film holding means

Claims (12)

  A transparent protective film is provided on both sides of the polarizing film, and at least one high refractive index layer having a refractive index higher than that of the transparent protective film is provided on one side of the transparent protective film, and the refractive index is higher than the refractive index of the transparent protective film. A polarizing plate in which an antireflection film having a multilayer structure in which at least one low refractive index layer having a low refractive index is sequentially coated is formed, and the low refractive index layer has a hollow structure having a refractive index of 1.17 to 1.37 A polarizing plate comprising at least one kind of inorganic fine particles having an average particle diameter of 30% to 100% of the thickness of the low refractive index layer.   The polarizing plate according to claim 1, wherein a transmittance at 700 nm in a crossed Nicol range is 0.001% to 0.3% and a transmittance at 410 nm is 0.001% to 0.3%. With respect to incident light having an incident angle of 5 ° in the wavelength range of 380 nm to 780 nm of the CIE standard light source D ₆₅ , each of the L ^* , a ^* , and b ^* values of the CIE1976L ^* a ^* b ^* color space of the specular reflection light The polarizing plate according to claim 1, wherein the in-plane change rate of the value is 20% or less.   The rate of change of light transmittance and degree of polarization of the polarizing plate before and after leaving the polarizing plate in an atmosphere of 60 ° C. and 90% RH for 500 hours is 3% or less based on absolute values. 4. The polarizing plate according to any one of items 1 to 3.   When the polarizing plate is placed under heating at 70 ° C. for 120 hours, the dimensional change rate in the absorption axis direction and the dimensional change rate in the polarization axis direction before and after the polarizing plate are both within ± 0.6%. The polarizing plate of any one of Claims 1 thru | or 4.   The polarizing plate according to claim 1, wherein an angle between the stretching axis of the transparent protective film and the stretching axis of the polarizing film is 10 ° or more and less than 90 °.   The polarizing plate according to claim 1, wherein an optical compensation film having an optically anisotropic layer is provided on the transparent protective film on the other side. The polarizing film is manufactured by holding both ends of the polymer film for polarizing film that is continuously supplied by holding means, and stretching the holding means while applying the tension in the longitudinal direction of the film. In the manufacturing method of the polarizing plate, the locus L1 of the holding means from the substantial holding start point of one end of the polymer film for polarizing film to the substantial holding release point, and the substance of the other end of the polymer film for polarizing film The path L2 of the holding means from the general holding start point to the holding release point and the distance W between the substantial holding release points of both holding means satisfy the following formula (1), and the conveying speed in the longitudinal direction of both holding means The manufacturing method of the polarizing plate characterized by being manufactured by the extending | stretching method whose difference of is less than 1%.
Formula (1): | L2-L1 |> 0.4W   9. The polymer film for polarizing film is stretched while the volatile content is maintained at 5% by volume or more and then the volatile content is decreased while being contracted when the polymer film for polarizing film is stretched. Manufacturing method of this polarizing plate.   The manufacturing method of the polarizing plate of Claim 8 or 9 which provides an antireflection film by sticking together the transparent protective film with which the antireflection film was coated on one side of a polarizing film.   8. An image display device, wherein the polarizing plate according to claim 1 is disposed on an image display surface.   12. The image display device according to claim 11, wherein the image display device is a transmissive, reflective, or transflective liquid crystal display device in any one mode of TN, STN, IPS, VA, and OCB.

Images