JP2010134323A - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the contrast of a blue-phase mode liquid crystal display and visibility in a dark place. <P>SOLUTION: The liquid crystal display includes polarizing plates on both the sides of a liquid crystal cell. A liquid crystal medium, which shows optical isotropy when no electric field is applied, and when an electric field is applied, generates optical anisotropy, is sealed into the liquid crystal cell. The polarizing plate includes a structure of holding a polarizer between two polarizing plate protection films, and at least one of the polarizing plate protection films is an anti-glare hard coat film having a transparent film base material and a hard coat layer, wherein the inner haze of the transparent film base material is 10 to 60% and the surface haze of the hard coat layer is 1.0 to 15%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device. More specifically, the present invention relates to a liquid crystal display device that exhibits optical isotropy when no electric field is applied and exhibits optical anisotropy according to the magnitude of the applied electric field. In particular, the present invention relates to a liquid crystal display device in which contrast and visibility in a bright place are remarkably improved.

  In recent years, liquid crystal display devices have been widely used, but other types of displays having excellent performance have been proposed. Specifically, the rise of organic EL displays can be mentioned. Organic EL displays have excellent video characteristics due to their high response speed, maintain high contrast even when viewed from an oblique direction, and color in a wide range of brightness from dark to bright. It has a differentiating factor from the liquid crystal display device in terms of performance, such as almost no change in reproduction area. Under these circumstances, further development of performance that is not inferior to other types of displays is required for the development of liquid crystal display devices in the future.

  In response to such demands for cost and performance, recent developments in the development of innovative liquid crystal display elements have become active. The blue phase liquid crystal mode disclosed in Patent Document 1 and Patent Document 2 is a typical example. The actual panel of this new mode liquid crystal is disclosed by Samsung Electronics Co., Ltd. as SID2008. The features of this mode are that it does not require an alignment film for aligning liquid crystals, is optically isotropic in the absence of an electric field, and has an optical anisotropy depending on its magnitude when an electric field is applied. Because it is a manifestation method, it does not require a retardation film that compensates for anisotropy, and furthermore, a high-speed response in the order of microseconds is possible. It is a liquid crystal display device having excellent performance such as the possibility of eliminating the need for a color filter when combined with a field sequential method of flashing at high speed. (See Non-Patent Document 1 and Non-Patent Document 2.)

However, this mode has a problem of improving contrast, particularly visibility in a bright place. For example, a liquid crystal display device called a digital signage provided in a public facility such as a station premises is said to have an increasing need in the future, but is required to have sufficient visibility even in the daytime outdoors.
JP 2005-234541 A JP 2006-99038 A Hiroki Kikuchi, "New world of liquid crystals with high molecular and chiral effects-Anomalous Kerr effect of isotropic liquid crystals", Liquid Crystal, Vol. 9, No. 2, p82-95, 2005 Eric Grelet, and three others “Structural Investigations on Spectrum Blue Phases”, PHYSICAL REVIEW LETTERS, The American Physical Society, 23 APRIL 2001, VOLUE 2001, 86N 3791-3794

  Accordingly, an object of the present invention is to improve the contrast and visibility in a bright place of a blue phase liquid crystal display device.

  The above object of the present invention is achieved by the following configurations.

  1. In a liquid crystal display device having polarizing plates on both sides of a liquid crystal cell, the liquid crystal cell exhibits optical isotropy when an electric field is not applied, and exhibits optical anisotropy according to the magnitude of the applied electric field. A liquid crystal medium to be expressed is enclosed, and the polarizing plate has a structure in which a polarizer is sandwiched between two polarizing plate protective films, and at least one of the polarizing plate protective films includes a transparent film substrate and a hard film. The antiglare hard coat film has a coat layer, the internal haze of the transparent film substrate is 10 to 60%, and the surface haze of the hard coat layer is 1.0 to 15%. A liquid crystal display device.

  2. 2. The liquid crystal display device as described in 1 above, wherein a low refractive index layer is provided directly or via another layer on the antiglare hard coat film.

  According to the present invention, the contrast of a blue phase liquid crystal display device and the visibility in a bright place can be improved.

  The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto.

  In the present invention, a liquid crystal cell in which a liquid crystal medium that exhibits optical isotropy when an electric field is not applied and exhibits an optical anisotropy according to the magnitude of the applied electric field is encapsulated is a blue phase. This is synonymous with a liquid crystal cell.

  By using the antiglare hard coat film according to the present invention, the contrast and the visibility in a bright place, which is a problem of the liquid crystal display device having the blue phase type liquid crystal cell, can be remarkably improved. The antiglare hard coat film of the present invention is characterized by having a high internal haze as a transparent film substrate. The reason why the effect of the present invention can be obtained is that the surface scattering function and the internal scattering function are separated from each other rather than providing the antiglare property with only the conventional hard coat layer, and the internal scattering function is mainly provided in the transparent film substrate. It is presumed that the reduction of the contrast due to light scattering caused by the blue phase type liquid crystal cell and the reduction of the visibility in a bright place are remarkably suppressed, and the visibility is improved.

<Liquid crystal cell>
The liquid crystal cell of the present invention is a liquid crystal display element in which a liquid crystal medium which exhibits optical isotropy when no electric field is applied and which exhibits optical anisotropy according to the magnitude of the applied electric field is enclosed. is there.

  Here, the medium refers to liquid crystal molecules sealed in the liquid crystal cell.

  In conventional liquid crystal display elements represented by the TN mode, VA mode, and IPS mode, liquid crystal molecules as a medium are aligned in some direction even when no electric field is applied, and the alignment direction is changed by applying a voltage. Display (transmittance modulation).

  That is, in the conventional method, the shape of the refractive index ellipsoid, which is a medium enclosed in the liquid crystal cell, does not change, but the main axis direction of the refractive index ellipsoid is rotated (changed) by applying an electric field. Display is in progress. Further, the shape of the refractive index ellipsoid is almost the same between when no electric field is applied and when an electric field is applied.

  That is, in the conventional liquid crystal display element, the degree of alignment order of liquid crystal molecules above visible light is constant, and display (modulation of transmittance) is performed by changing the alignment direction.

  On the other hand, in the liquid crystal display device of the present invention, the shape of the refractive index ellipsoid as a medium is deformed by applying an electric field, and the degree of deformation is changed by the strength of the electric field.

  Therefore, unlike the conventional liquid crystal display device, there is no problem that the inherent viscosity of the liquid crystal greatly affects the response speed, and a high-speed response can be realized.

  Further, since the display is performed using the change in the degree of optical anisotropy in the medium, a wider viewing angle characteristic can be realized.

  The medium of the present invention only needs to change the optical anisotropy depending on the level of the electric field to be applied, and preferably has a spherical shape when no electric field is applied or when an electric field is applied. It becomes spherical when no electric field is applied and is optically isotropic.

  That is, when no electric field is applied, optically isotropic (nx = ny = nz, degree of orientational order in visible light or higher = 0 (the degree of orientational order is greater than the visible wavelength range and light having a wavelength greater than the visible wavelength range). The optical anisotropy (nx> ny, the degree of orientational order above visible light> 0 (the degree of orientational order is in the visible light wavelength region and visible range). A size that affects light having a wavelength larger than the light wavelength range)) is developed, and the refractive index ellipsoid becomes elliptic (shows optical anisotropy).

  Here, isotropic means ideally nx = ny = nz, and can be determined to be isotropic if each is within a range of ± 10%.

  Note that nx, ny, and nz are the main refractive index in the direction parallel to the substrate surface (in-plane direction of the substrate) and the opposing direction of the electrodes provided on the substrate surface, and the direction perpendicular to the substrate surface (substrate method) (Line direction) and the main refractive index in the direction parallel to the substrate surface (in-plane direction of the substrate) and perpendicular to the opposing direction of the electrodes.

  The major axis direction of the refractive index ellipsoid when the electric field is applied is parallel to the electric field direction (in the case of a medium having a positive dielectric anisotropy) or perpendicular (a medium having a negative dielectric anisotropy is used). Case).

  As described above, the display element according to the present embodiment performs display by modulating the degree of orientation order above visible light, for example, while the direction of optical anisotropy is constant (the electric field application direction does not change).

  That is, in the display element according to the present embodiment, the degree of optical anisotropy (or the degree of orientation order above visible light) of the medium itself changes, and the display principle is greatly different from that of a conventional liquid crystal display element. Is.

  This technique is described in detail in Patent Documents 1 and 2. Also, a prototype panel that is said to use the blue phase liquid crystal system, which is a typical example of this technology, is disclosed by Samsung Electronics Co., Ltd. at SID2008.

<Anti-glare hard coat film>
The antiglare hard coat film used in the present invention is characterized in that the internal haze of the transparent film substrate is 10 to 60%, and the surface haze of the hard coat layer is 1.0 to 15%.

  With such a configuration, it is possible to maintain the antiglare property, improve the sharpness of the image without causing glare due to internal scattering, and improve visibility.

  In order to make the internal haze of the transparent film substrate 10 to 60%, it is not particularly limited. For example, the average particle size is 0.2 μm or more and less than 2.0 μm, and the refraction with the transparent film substrate is This can be achieved by containing particles having a rate difference of 0.02 or more and 0.3 or less in the transparent film substrate. Furthermore, it is preferable that the internal haze of a transparent film base material is 25 to 40%.

  Moreover, in order to set the surface haze of the antiglare hard coat film to 1.0 to 15%, similarly, for example, a hard film is applied to a transparent film substrate in which a mold is pressed against the surface in advance to produce irregularities on the surface. There are a method of coating a layer, a method of coating a hard coat layer on a transparent film substrate that contains particles having an average particle size of 2.0 μm or more and less than 10.0 μm and has been stretched.

  Thus, in order to set the surface haze of the antiglare hard coat film to 1.0 to 15%, it is also effective for improving the contrast to adjust the surface structure of the transparent film substrate as the base. Further, the surface haze of the antiglare hard coat film is preferably 2.0 to 15%.

  The hard coat layer preferably contains fluorine-containing acrylic resin particles having an average particle size of 0.5 to 6 μm.

  The anti-glare property as used in the present invention is to reduce the visibility of the reflected image by blurring the outline of the image reflected on the surface of the film substrate, and the reflection of the reflected image is a concern when using an image display device or the like. It is to prevent it from becoming.

<Transparent film substrate>
The haze of the transparent film substrate of the present invention can be measured by the following procedure.
(1) The total haze value (H) of the transparent film substrate is measured with a haze meter (T-2600DA, manufactured by Tokyo Denshoku) according to JIS-K7136.
(2) A polyethylene terephthalate film with pressure-sensitive adhesive with an acrylic pressure-sensitive adhesive applied to one surface is pasted on the surface of the transparent film substrate of the present invention, and the total haze value H0 is measured for the whole pasted material. Separately, the total haze value Ht of only the polyethylene terephthalate film with adhesive to which the acrylic adhesive was applied was measured, and the value obtained by subtracting Ht from the previously measured H0 was defined as the internal haze value Hi. (Hi = H0-Ht)
(3) A value obtained by subtracting the internal haze (Hi) calculated in (2) from the total haze (H) measured in (1) above is calculated as the surface haze (Hs) of the film. (Hs = H-Hi)
One or more layers may be sufficient as the transparent film base material of this invention. For example, two or more layers may be co-cast, or may be bonded later.

  The refractive index of a transparent film base material can be measured by A method (method using an Abbe refractometer) of JISK-7142-1996.

(Resin that forms a transparent film substrate)
The resin forming the transparent film substrate of the present invention is easy to manufacture, has good adhesion to the antiglare hard coat layer, is optically isotropic, and is optically transparent. There are some preferable requirements.

  Although it will not specifically limit if it has said property, For example, cellulose ester-type films, such as a cellulose diacetate film, a cellulose triacetate film, a cellulose acetate propionate film, a cellulose acetate butyrate film, a polyester-type film, a polycarbonate Film, polyarylate film, polysulfone (including polyethersulfone) film, polyester film such as polyethylene terephthalate and polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol Film, syndiotactic polystyrene film, cycloolefin polymer fill (Arton (manufactured by JSR)), ZEONEX, ZEONOR (manufactured by Nippon Zeon), polyvinyl acetal, polymethylpentene film, polyetherketone film, polyetherketoneimide film, polyamide film, fluororesin film, nylon film, A polymethyl methacrylate film, an acrylic film, a glass plate, etc. can be mentioned.

  Among these, a cellulose ester film, a polycarbonate film, a polysulfone (including polyether sulfone) film, and a cycloolefin polymer film are preferable, and a cellulose ester film is particularly preferable.

  These films may be films produced by melt casting film formation or films produced by solution casting film formation.

  Among them, it is preferable to use a cellulose ester film in which X and Y are in the following ranges, where X is the substitution degree of the acetyl group and Y is the substitution degree of the propionyl group or butyryl group.

2.3 ≦ X + Y ≦ 3.0 0.1 ≦ Y ≦ 2.0
In particular, it is preferable that 2.5 ≦ X + Y ≦ 2.9 0.3 ≦ Y ≦ 1.2.

  The measuring method of the substitution degree of an acyl group can be measured according to the rule of ASTM-D817-96.

  Hereinafter, the cellulose ester film which is a preferable transparent film base material is demonstrated in detail.

  The number average molecular weight of the cellulose ester is preferably from 50,000 to 250,000 because the mechanical strength when molded is high and an appropriate dope viscosity is obtained, and more preferably from 80,000 to 150,000.

  Cellulose ester film is a solution in which a cellulose ester solution (dope), commonly referred to as a solution casting film forming method, is pressed onto a casting support of an endless metal belt or rotating metal drum, for example. It is manufactured by casting a dope from a die and forming a film.

  Among the above good solvents, methylene chloride or methyl acetate having excellent solubility is preferably used.

  In addition to the organic solvent, it is preferable to contain 0.1 to 40% by mass of an alcohol having 1 to 4 carbon atoms. It is particularly preferable that the alcohol is contained at 5 to 30% by mass.

  After casting the above dope onto the casting support, the solvent starts to evaporate and the alcohol ratio increases and the web (dope film) gels, making the web strong and peeling from the casting support. It is also used as a gelling solvent for facilitating, and when these ratios are small, it also has a role of promoting dissolution of a cellulose ester of a non-chlorine organic solvent.

  Methyl acetate can be used in place of methylene chloride. At this time, the dope may be prepared by a cooling dissolution method.

  The cellulose ester film preferably contains the following plasticizer. Examples of plasticizers include phosphate ester plasticizers, polyhydric alcohol ester plasticizers, phthalate ester plasticizers, trimellitic ester plasticizers, pyromellitic acid plasticizers, glycolate plasticizers, Citric acid ester plasticizer, polyester plasticizer, fatty acid ester plasticizer, polyvalent carboxylic acid ester plasticizer, 1 or more and 12 or less of at least one of pyranose structure or furanose structure An ester compound or the like obtained by esterifying all or part thereof can be preferably used.

  In addition, it is preferable to contain an acrylic polymer (this expression includes an acrylic oligomer) having a weight average molecular weight of 500 or more and 30000 or less that exhibits negative orientation birefringence with respect to the stretching direction.

  By controlling the composition of the polymer so that the weight average molecular weight of the polymer is 500 or more and 30000 or less, the compatibility between the cellulose ester and the polymer can be improved.

  The total content of the plasticizer in the cellulose ester film is preferably 5 to 20% by mass, more preferably 6 to 16% by mass, and particularly preferably 8 to 13% by mass with respect to the total solid content.

  The contents of the two kinds of plasticizers are each at least 1% by mass, preferably 2% by mass or more.

  The polyhydric alcohol ester plasticizer is preferably contained in an amount of 1 to 15% by mass, particularly preferably 3 to 11% by mass.

(Particles used to impart haze)
In order to adjust the internal haze of the transparent film substrate, particles having an average particle size of 0.2 μm or more and less than 2.0 μm and a difference in refractive index from the transparent film substrate of 0.02 or more and 0.3 or less are used. It is preferable. In order to obtain the effects of the present invention, a difference in refractive index of 0.02 or more should suffice, but it is preferably 0.3 or less in consideration of materials that can be substantially supplied.

  For example, when the transparent film base resin is triacetyl cellulose (refractive index 1.48), the material of the particles that can be used in the present invention is organic resin particles, polymethyl methacrylate particles (refractive index 1.49). ), Methyl methacrylate-styrene copolymer particles (refractive index 1.55), melamine resin particles (refractive index 1.57), polycarbonate particles (refractive index 1.58), polystyrene particles (refractive index 1.59), poly Vinyl chloride particles (refractive index 1.60), fluorine-containing acrylic resin particles (refractive index 1.42), benzoguanamine / formaldehyde condensate (refractive index 1.66), melamine / formaldehyde condensate (refractive index 1.66), etc. Examples of the inorganic particles include amorphous silica particles.

  These particles include Eposter S12 (1.5 μm, 1.66), Eposter S6 (0.40 μm, 1.66), Eposter S (0.2 μm, 1.66), Seahoster KE-P10 (0.11 μm, 1.43), Seahoster KE-P30 (0.31 μm, 1.43), Seahoster KE-P50 (0.59 μm, 1.43), Seahoster KE-P100 (1.15 μm, 1.43), Seahoster KE- P150 (1.58 μm, 1.43) (manufactured by Nippon Shokubai Co., Ltd.), Chemisnow MP (0.5 μm, 1.49) (manufactured by Soken Chemical Co., Ltd.) and the like are commercially available. In addition, the inside of () represents (average particle diameter, the refractive index in 590 nm).

  These particles can be contained in the range of 0.1 to 30% by mass with respect to the transparent film base resin, and the internal haze and refractive index of the transparent film base material can be selected by appropriately selecting the amount and type thereof. The difference can be adjusted.

  The average particle diameter of the particles can be measured from an electron micrograph taken with a scanning electron microscope (SEM) or the like.

  Specifically, a micrograph (1000 times transmission mode) of the sample containing the particles was taken, and the diameter of the particles in the photograph was measured with an image processing device LUZEX-III (manufactured by Nireco), and the average The value was calculated as the average particle size. Hereinafter, this measuring method was used for the average particle diameter of the particles of the present invention.

  The refractive index of the particles can be measured by B method (immersion method using a microscope: Becke line method) of JISK-7142-1996.

  In order to adjust the surface haze of the antiglare hard coat film, it is preferable to use particles having an average particle size of 2.0 μm or more and less than 10.0 μm.

  As particles having an average particle size of 2.0 μm or more and less than 10.0 μm, either organic resin particles or inorganic particles can be used.

  Organic resin particles include polymethyl methacrylate particles, methyl methacrylate-styrene copolymer particles, melamine resin particles, polycarbonate particles, polystyrene particles, polyvinyl chloride particles, fluorine-containing acrylic resin particles, benzoguanamine / formaldehyde condensates, melamine / formaldehyde A condensate etc. are mentioned, As an inorganic particle, an amorphous silica particle etc. are mentioned.

  These particles are shown in Eposter M05 (5 μm), Eposter M30 (3.3 μm), Eposter SC4 (3.5 μm), Eposter M1002 (2.5 μm), Eposter M1004 (4.5 μm), Eposter M1006 (6 μm), Eposter. M1010 (10 μm), Eposter GPH70 (7 μm), Eposter YS60 (6 μm), Seahoster KE-P250 (2.5 μm) (above, Nippon Shokubai Co., Ltd.), Chemisnow MX (3 μm) Chemisnow MR (10 μm) (above, Sokenken Chemical Co., Ltd.), Techpolymer MBX5 (5 μm), Techpolymer SBX6 (6 μm) (Sekisui Chemicals Co., Ltd.) are commercially available.

<Other additives>
Commonly used additives such as ultraviolet absorbers, antioxidants, thermal deterioration inhibitors and the like can be added to the transparent film substrate of the present invention.

(Method to create irregularities on the surface by pressing the mold in advance on the surface)
Examples of a method for producing irregularities on the surface by pressing a mold on the surface in advance, which can be preferably used in the present invention, include the method described in JP-A-2005-156615.

  FIG. 1 is a schematic view of an uneven surface forming apparatus using a mold roll. A pre-prepared thermoplastic resin solution is cast from a die 1 onto a casting belt 2 to form a web (a film containing a residual solvent after casting a dope on a metal support is called a web). Then, an uneven surface is formed on the web by the mold roll 3 for forming the uneven surface after peeling and the back roll 4 facing it.

  Thereafter, the web is stretched by the tenter 5, dried by the next film drying device 6, and taken up by the take-up roll 7.

  The mold roll 3 for forming an uneven surface and the back roll 4 (which may not be used) opposed to the mold roll 3 can be placed in the film drying apparatus and at the film drying apparatus outlet after the tenter.

  It is also preferable to arrange the uneven surface forming mold roll 3 and the back roll 4 opposed thereto at a plurality of locations. Further, two or more mold rolls 3 or two or more mold rolls 3 can be used as one set.

  Further, in the present invention, it is preferable that the uneven processing by the mold is performed in the film forming process. Compared to the case where the film once wound up in the film forming process is processed with a mold in another line, it is not only preferable because the risk of dust and foreign matter adhering to the mold before and after the uneven processing by the mold is low, and failure is reduced. Unevenness is easy to form.

  When a plurality of mold rolls are used, the unevenness can be formed more uniformly and randomly, and a complicated uneven shape can be formed.

  When forming irregularities using two or more mold rolls, it is preferable to provide irregularities with the temperature of the mold roll surface being different by 1 ° C. or more.

  By changing the temperature, the shape of the unevenness can be controlled. For example, unevenness with a larger Ra can be formed by raising the temperature.

  As the mold roll used for forming the concavo-convex surface of the present invention, it can be appropriately selected and applied to those with fine irregularities, rough ones, patterns, mats, lenticular lenses, concave or convex parts consisting of a part of a spherical surface, A mold in which the molds for forming the prismatic irregularities are regularly or randomly arranged can be used.

  For example, a concave portion or a convex portion formed of a part of a sphere having a diameter of the convex portion or the concave portion of 5 to 100 μm and a height of 0.1 to 2 μm may be mentioned. .

  It is also possible to arrange a small plurality of back rolls around a large uneven surface forming mold roll, and conversely to arrange a small uneven surface forming mold roll with respect to a large back roll.

  The material of the mold roll and back roll can be metal, stainless steel, carbon steel, aluminum alloy, titanium alloy, ceramic, hard rubber, reinforced plastic, or a combination of these materials. From this point, the mold roll is preferably a metal.

  In particular, ease of cleaning and durability are also important, and it is preferable to use a stainless steel mold roll. Further, the surface may be subjected to water repellency or water repellency treatment.

  As a method for forming a desired concavo-convex surface on a mold roll, it can be formed using an etching method, a sandblasting method, a mechanical processing method, a mold, or the like. As the back roll, hard rubber or metal is preferably used.

  The eccentricity of the mold roll and the back roll is preferably 50 μm or less, more preferably 20 μm or less, and further preferably 0 to 5 μm.

  The diameter of the mold roll is preferably 5 to 200 cm, more preferably 10 to 100 cm, and particularly preferably 10 to 50 cm.

  In the present invention, the surface temperature T1 of the mold roll is preferably T2 + 10 ° C. to T2 + 55 ° C., preferably T2 + 30 ° C. to T2 + 50 ° C., with respect to the thermal deformation temperature T2 of the thermoplastic resin used. The heat distortion temperature T2 is a value measured according to ASTM D-648.

  If the surface temperature T1 of the mold roll is lower than the thermal deformation temperature T2, it becomes difficult to form a fine uneven shape. When the surface temperature T1 exceeds 55 ° C. than the thermal deformation temperature T2, the flatness of the obtained film tends to deteriorate.

  The surface temperature T1 of the mold roll can be controlled by setting the temperature of the mold roll itself, the ambient temperature, the film temperature for forming the unevenness, the residual solvent amount of the film, and the unevenness forming speed.

  The temperature of the mold roll itself can be controlled by circulating a temperature-controlled gas or liquid medium in the mold. For example, it is selected according to the type of resin and the uneven shape to be formed in the range of 40 to 300 ° C., preferably 50 to 250 ° C.

  At that time, it is preferable to prevent the residual solvent in the film from foaming, and even if the surface of the mold roll is at a temperature equal to or higher than the boiling point of the residual solvent, foaming can be prevented if the unevenness is formed at a high speed. For example, irregularities can be formed at a speed of 10 m / min or more.

  The temperature of the back roll is preferably controlled in the same manner, and is preferably set to a temperature equal to or lower than that of the mold roll.

  The roll pressure at the time of forming the unevenness is appropriately determined from a linear pressure of 5 to 500 N / cm, more preferably from 30 to 500 N / cm in consideration of the type of the thermoplastic resin, the shape of the unevenness to be formed, the temperature, and the like. .

  Furthermore, the preferable aspect of the manufacturing method of uneven | corrugated surface formation is shown below.

  In the present invention, the transparent film substrate heated in the process is not brought back to room temperature, but the mold is pressed against the film surface to form irregularities on the surface, and the mold is pressed against the film surface in the film forming process. Before or after forming irregularities on the surface, stretched with a tenter, stretched in the longitudinal direction and then pressed against the film surface to form irregularities on the surface, the film forming process is a solution casting method, The film base is dissolved in an organic solvent, and then the dope is cast on a support having a smooth surface. After the organic solvent is volatilized on the support until it becomes peelable, the film having the smooth surface is dried. In one of the processes, the mold is pressed against the film substrate surface to form irregularities on the surface, and in the solution casting film forming process, the mold is pressed against the film substrate containing residual solvent to cause irregularities on the surface. Form the A manufacturing method for forming irregularities with a mold when the poor solvent ratio in the residual solvent is 10% by mass or more, and a step of pressing the mold against the film surface to form irregularities on the surface and then heat treating at 100 ° C. or higher. , A manufacturing method in which a mold is pressed against a film substrate having two or more layers by co-casting or sequential casting or coating to form irregularities on the surface, and a static eliminator is provided before or after the irregularity imparting portion by the mold A manufacturing method is a preferable mode for forming an uneven surface with good stable reproduction.

  Moreover, as for the conveyance speed of the film at the time of forming an unevenness | corrugation, 10 m / min-100 m / min are preferable.

  Further, the transparent film substrate of the present invention contains particles having an average particle size of 2.0 μm or more and less than 10.0 μm, and is subjected to a stretching treatment, thereby providing an antiglare hard coat layer thereon, and an antiglare hard coat. It is also preferable that the surface haze of the film be 1.0 to 15%.

  Stretching treatment is normal 1.0-3.0 times longitudinal stretching (also called stretching in the transport direction, MD stretching), 1.01-5.0 times lateral stretching processing (stretching in a direction perpendicular to the transport direction) TD stretching) can be used, and it is preferable to perform a transverse stretching treatment.

<Anti-glare hard coat layer>
The antiglare hard coat film of the present invention has an antiglare hard coat layer on at least one surface of a transparent film substrate, and the surface haze of the antiglare hard coat layer is 1.0 to 15%. It is characterized by being.

  The surface haze is measured according to the following procedure.

The haze is measured using a haze meter (NDH2000 type, manufactured by Nippon Denshoku Industries Co., Ltd.) according to JIS K-7136 for each sample that was conditioned for 24 hours in an air-conditioned room at 23 ° C. and 55% RH.
(1) The total haze value (H) of the film is measured according to JIS-K7136.
(2) A few drops of silicone oil are added to the front and back surfaces of the antiglare hard coat layer side of the film, and sandwiched from the front and back using two 1 mm thick glass plates (micro slide glass product number S9111, manufactured by MATSANAMI) Then, the two glass plates and the film were optically closely adhered, the haze was measured with the surface haze removed, and the haze was measured by sandwiching only the silicone oil between two separately measured glass plates. Is calculated as the internal haze (Hi) of the film.
(3) A value obtained by subtracting the internal haze (Hi) calculated in (2) from the total haze (H) measured in (1) above is calculated as the surface haze (Hs) of the film.

  This antiglare hard coat layer basically has a structure containing fluorine-containing acrylic resin particles having an average particle size of 0.5 to 6 μm in a binder layer mainly composed of a transparent resin, for example, an active energy ray curable resin. It is preferable to have.

  The fluorine-containing acrylic resin particles of the present invention are, for example, particles formed from a fluorine-containing acrylic ester or methacrylic ester polymer.

  Specific examples of the fluorine-containing acrylic ester or methacrylic ester include 1H, 1H, 3H-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, 1H, 1H, 7H- Dodecafluoroheptyl (meth) acrylate, 1H, 1H, 9H-hexadecafluorononyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (Meth) acrylate, 2- (perfluorobutyl) ethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2-perfluorodecylethyl (Meth) acrylate, 3-par Fluorobutyl-2-hydroxypropyl (meth) acrylate, 3-perfluorohexyl-2-hydroxypropyl (meth) acrylate, 3-perfluorooctyl-2-hydroxypropyl (meth) acrylate, 2- (perfluoro-3-methylbutyl) ) Ethyl (meth) acrylate, 2- (perfluoro-5-methylhexyl) ethyl (meth) acrylate, 2- (perfluoro-7-methyloctyl) ethyl (meth) acrylate, 3- (perfluoro-3-methylbutyl) ) -2-hydroxypropyl (meth) acrylate, 3- (perfluoro-5-methylhexyl) -2-hydroxypropyl (meth) acrylate, 3- (perfluoro-7-methyloctyl) -2-hydroxypropyl (meth) ) Acrylate, 1H-1 (Trifluoromethyl) trifluoroethyl (meth) acrylate, 1H, 1H, 3H-hexafluorobutyl (meth) acrylate, trifluoroethyl methacrylate, tetrafluoropropyl methacrylate, perfluorooctylethyl acrylate, 2- (perfluorobutyl) Examples include ethyl-α-fluoroacrylate.

  Among the fluorine-containing acrylic resin particles, particles made of 2- (perfluorobutyl) ethyl-α-fluoroacrylate, fluorine-containing polymethyl methacrylate particles, and fluorine-containing methacrylic acid in the presence of a crosslinking agent are vinyl monomers. Particles copolymerized with are preferred, and fluorine-containing polymethyl methacrylate particles are more preferred.

  A vinyl monomer copolymerizable with a fluorine-containing (meth) acrylic acid ester may be copolymerized.

  These may be those having a vinyl group, specifically, methacrylic acid alkyl esters such as methyl methacrylate and butyl methacrylate, alkyl acrylates such as methyl acrylate and ethyl acrylate, styrene, α -Styrenes, such as methylstyrene, etc. are mentioned, These can be used individually or in mixture.

  The crosslinking agent used in the polymerization reaction is not particularly limited, but those having two or more unsaturated groups are preferably used. For example, bifunctional dimethacrylates such as ethylene glycol dimethacrylate and polyethylene glycol dimethacrylate are used. And trimethylolpropane trimethacrylate, divinylbenzene and the like.

  The polymerization reaction for producing the fluorine-containing polymethyl methacrylate particles may be either random copolymerization or block copolymerization. Specifically, for example, the method described in JP-A No. 2000-169658 can also be mentioned.

  As a commercial item, Nippon Paint Co., Ltd. product: F-191, Negami Kogyo Co., Ltd. product: MF-0043, etc. are mentioned. These fluorine-containing acrylic resin particles may be used alone or in combination of two or more.

  Moreover, the state of these fluorine-containing acrylic resin particles may be added in any state such as powder or emulsion.

  Moreover, you may use the fluorine-containing crosslinked particle as described in Paragraphs 0028-0055 of Unexamined-Japanese-Patent No. 2004-83707.

  The refractive index of the fluorine-containing acrylic resin particles is preferably 1.38 to 1.46.

  As content of the fluorine-containing acrylic resin particle of this invention, 0.01-500 mass parts is preferable with respect to 100 mass parts of transparent resin which comprises an anti-glare hard-coat layer, More preferably, it is 0.1-100. Part by mass, particularly preferably 1 to 60 parts by mass.

  The average particle diameter of the fluorine-containing acrylic resin particles is 0.5 to 6 μm, and preferably 0.55 to 4.0 μm.

  The average particle diameter is 100 particles obtained by taking a scanning electron micrograph of the particles (1000 particles or more), and using the image processing apparatus LUZEX-III (manufactured by Nireco) as the diameter of the particles in the photograph. The average value was measured and the average value was calculated.

  In the present invention, it is also preferable to contain particles having an average particle diameter of 0.01 to 1 μm, and examples of the particles include acrylic particles and inorganic particles mainly composed of silica.

  Examples of the silica particles include product names such as Nippon Aerosil Co., Ltd., Aerosil 200, 200V, 300, Degussa, Aerosil OX50, TT600, Nippon Shokubai Co., Ltd., KEP-10, KEP-50, KEP-100 and the like.

  Colloidal silica may also be used. Colloidal silica is obtained by dispersing silicon dioxide in water or an organic solvent in a colloidal form, and is not particularly limited, and is spherical, acicular or beaded.

  Such colloidal silica is commercially available, and examples thereof include the Snowtex series of Nissan Chemical Industries, the Cataloid-S series of Catalytic Chemical Industries, and the Rebacil series of Bayer.

  Also, beaded colloidal silica in which primary particles of cation-modified with alumina sol or aluminum hydroxide are bonded in a bead shape by bonding the particles with divalent or higher metal ions.

  Examples of the bead-like colloidal silica include SNOWTEX-AK series, SNOWTEX-PS series, SNOWTEX-UP series, etc. manufactured by Nissan Chemical Industries, Ltd. Specifically, IPS-ST-L (isopropanol silica sol, particle size 40-50 nm). , Silica concentration 30%), MEK-ST-MS (methyl ethyl ketone silica sol, particle diameter 17-23 nm, silica concentration 35%), etc. MEK-ST (methyl ethyl ketone silica sol, particle diameter 10-15 nm, silica concentration 30%), MEK- ST-L (methyl ethyl ketone silica sol, particle diameter 40-50 nm, silica concentration 30%), MEK-ST-UP (methyl ethyl ketone silica sol, particle diameter 9-15 nm (chain structure), silica concentration 20%) and the like can be mentioned.

  Examples of the acrylic particles include fluorine-containing acrylic resin particles. For example, Nippon Paint: S-4000, FS-701, and acrylic-styrene particles include, for example, Nippon Paint: S-1200, MG-251. .

  Among these particles having an average particle diameter of 0.01 to 1 μm, fluorine-containing acrylic resin particles are preferable.

  Particles having an average particle size of 0.01 to 1 μm constitute the antiglare hard coat layer as the content from the stability of the coating liquid forming the antiglare hard coat layer and the dispersibility of the dispersion. 0.01-500 mass parts is preferable with respect to 100 mass parts of transparent resin, More preferably, it is 0.1-100 mass parts.

  The content ratio with respect to particles having an average particle diameter of 0.01 to 1 μm can be appropriately selected within a range of 0 to 500 mass% with respect to particles having an average particle diameter of 1.5 to 6 μm.

The particles may be added in any state such as powder or emulsion. Moreover, the density of the translucent particles is preferably 10 to 1000 mg / m ² , more preferably 100 to 700 mg / m ² .

(Transparent resin)
As the refractive index of the transparent resin constituting the antiglare hard coat layer of the present invention, a resin of about 1.4 to 1.7 is used, but it is particularly preferably 1.50 or more, more preferably 1. .50 to 1.70.

  In order to make the refractive index within this range, the type and amount ratio of the transparent resin may be appropriately selected. If the refractive index is less than 1.50, it is difficult to obtain a resin with high hardness. If the refractive index is greater than 1.70, unevenness of the film tends to be noticeable.

  The refractive index of the transparent resin can be quantitatively evaluated by directly measuring it with an Abbe refractometer or by measuring a spectral reflection spectrum or a spectral ellipsometry.

  The transparent resin is preferably a binder polymer having a saturated hydrocarbon chain or a polyether chain as a main chain, and more preferably a binder polymer having a saturated hydrocarbon chain as a main chain.

  Particularly preferred is a resin that cures through a crosslinking reaction or the like by irradiation with active rays such as ultraviolet rays or electron beams.

  Examples of the curable resin include UV curable urethane acrylate resins, UV curable polyester acrylate resins, UV curable epoxy acrylate resins, UV curable polyol acrylate resins, and UV curable epoxy resins. A type acrylate resin is preferably used.

  The UV curable urethane acrylate resin generally includes a product obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer, and further includes 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter, acrylate includes methacrylate). It can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate.

  For example, those described in JP 59-151110 A can be used. For example, a mixture of 100 parts Unidic 17-806 (Dainippon Ink Co., Ltd.) and 1 part Coronate L (Nihon Polyurethane Co., Ltd.) is preferably used.

  Examples of UV curable polyester acrylate resins include those which are easily formed when 2-hydroxyethyl acrylate and 2-hydroxy acrylate monomers are generally reacted with polyester polyols. JP-A-59-151112 Those described in the publication can be used.

  Specific examples of the ultraviolet curable epoxy acrylate resin include an epoxy acrylate as an oligomer, a reactive diluent and a photopolymerization initiator added thereto, and reacted to form an oligomer. Those described in Japanese Patent No. 105738 can be used.

  Specific examples of UV curable polyol acrylate resins include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, etc. Can be mentioned.

  Specific examples of photopolymerization initiators for these curable resins include benzoin and derivatives thereof, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. You may use with a photosensitizer.

  In addition, when using an epoxy acrylate photopolymerization initiator, a sensitizer such as n-butylamine, triethylamine, tri-n-butylphosphine can be used.

  The photopolymerization initiator or photosensitizer used in the curable resin composition is 0.1 to 25 parts by mass, preferably 1 to 15 parts by mass with respect to 100 parts by mass of the composition.

  As acrylate resins, methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, cyclohexyl acrylate, ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyl dimethyl adiacrylate , Trimethylolpropane triacrylate, pentaerythritol tetraacrylic ester and the like.

  As these commercial products, Adekaoptomer KR / BY series: KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (manufactured by Asahi Denka Co., Ltd.); -101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102, NS-101, FT-102Q8, MAG -1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Co., Ltd.); Seika Beam PHC2210 (S), PHC X-9 (K-3), PHC2213, DP-10, DP-20, DP -30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (manufactured by Dainichi Seika Kogyo Co., Ltd.); KRM7033, KRM703 , KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (manufactured by Daicel UCB); RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC-5120, RC-5122 RC-5152, RC-5171, RC-5180, RC-5181 (Dainippon Ink Chemical Co., Ltd.); 340 clear (manufactured by China Paint Co., Ltd.); Sunrad H-601, RC-750, RC-700, RC-600, RC-500, RC-611, RC-612 (manufactured by Sanyo Chemical Industries); SP -1509, SP-1507 (manufactured by Showa Polymer Co., Ltd.); RCC-15C (manufactured by Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.), NK hard B-420, NK ester A-DOG, NK ester A-IBD-2E (manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like can be appropriately selected and used.

  Other examples include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dioxane glycol acrylate, ethoxylated acrylate, alkyl-modified dipentaerythritol pentaacrylate, etc. Can be mentioned.

  The antiglare hard coat layer may contain a fluorine-acrylic copolymer resin. The fluorine-acrylic copolymer resin is a copolymer resin composed of a fluorine monomer and an acrylic monomer, and a block copolymer composed of a fluorine monomer segment and an acrylic monomer segment is particularly preferable.

(Other substances contained in the antiglare hard coat layer)
For the antiglare hard coat layer, other organic particles include silicone resin powder, polystyrene resin powder, polycarbonate resin powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, or poly An ultraviolet curable resin composition such as an ethylene fluoride resin powder can also be added.

  Moreover, you may further contain the particle | grains of Unexamined-Japanese-Patent No. 2000-241807 as needed.

  Further, the refractive index of the other particles is preferably 1.45 to 1.70, more preferably 1.45 to 1.65.

  Note that the refractive index of the particles is measured by measuring the turbidity by dispersing the same amount of particles in a solvent in which the refractive index is changed by changing the mixing ratio of two types of solvents having different refractive indexes. The refractive index of the solvent can be measured by measuring with an Abbe refractometer.

  Further, the antiglare hard coat layer preferably contains the following silicone surfactant, fluorine compound, polyoxyether compound or the like as the surfactant.

  These components increase productivity by imparting high-speed coating suitability while improving surface uniformity.

  Preferable examples of the fluorine-based compound include fluoroaliphatic group-containing copolymers, and specifically, the compounds and description methods described in paragraphs 0053 to 0082 of JP-A-2007-45142 can be used.

  In addition, the compounds and description methods described in paragraphs 0008 to 0031 of JP-A No. 2000-119354 can also be used.

  Since these components are added in the range of 0.01 to 5% by mass with respect to the solid content component in the coating solution, the effect of improving surface defects such as coating unevenness, drying unevenness, and point defects appears. preferable.

  In addition, as the fluorine-based compound, a copolymer polymer obtained by grafting siloxane (including polysiloxane) and / or organosiloxane (including organopolysiloxane) to a fluororesin can also be preferably used.

  Specific examples include ZX-022H, ZX-007C, ZX-049, and ZX-047-D manufactured by Fuji Chemical Industry Co., Ltd. These compounds may be used as a mixture.

  Commercially available products of polyoxyethylene alkyl ether include Emulgen 1108, Emulgen 1118S-70 (manufactured by Kao Corporation), and commercially available products of polyoxyethylene lauryl ether include Emulgen 103, Emulgen 104P, Emulgen 105, and Emulgen 106. , Emulgen 108P, Emulgen 120P, Emulgen 120P, Emulgen 123P, Emulgen 147, Emulgen 150, Emulgen 130K (above, manufactured by Kao Corporation), and polyoxyethylene cetyl ether as commercially available products include Emulgen 210P, Emulgen 220 (above, Kao Corporation), polyoxyethylene stearyl ether commercially available products such as Emulgen 220, Emulgen 306P (above, Kao Corporation), polyoxyalkylene alkyl ether market As the products, Emulgen LS-106, Emulgen LS-110, Emulgen LS-114, Emulgen MS-110 (manufactured by Kao Corporation), polyoxyethylene higher alcohol ether, commercially available products such as Emulgen 705, Emulgen 707, Emulgen 709 and the like.

  The polyoxyether compounds may be used alone or in combination of two or more. Moreover, you may use together an acetylene glycol type compound, a nonionic surfactant, a radically polymerizable nonionic surfactant, etc.

  The antiglare hard coat layer may contain a color tone adjusting agent (dye or pigment, etc.) having a color tone adjusting function as a color correction filter for various display elements.

  Moreover, you may make it contain an electromagnetic wave shielding agent or an infrared absorber, etc. and to have each function.

  The antiglare hard coat layer may contain other functional thiol compounds as curing aids, such as 1,4-bis (3-mercaptobutyryloxy) butane, pentaerythritol tetrakis (3-mercaptobutyrate). 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione and the like.

  Moreover, as a commercial item, Showa Denko Co., Ltd. make, brand name Karenz MT series, etc. are mentioned. The other functional thiol compound is preferably added in the range of 0.01 to 50 parts by mass, more preferably 0.05 to 30 parts by mass with respect to 100 parts by mass of the active energy ray-curable resin.

  By adding in the above range, it suitably acts as a curing aid and also exists stably in the antiglare hard coat layer.

  The antiglare hard coat layer is selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony in addition to the organic particles in order to improve hardness, prevent static charge, and adjust the refractive index of the layer. Inorganic particles having at least one metal oxide as a main component and having an average particle size of 10 μm or less, for example 2 μm or less, preferably 0.2 μm or less, particularly preferably 0.1 μm or less, more preferably 0.06 μm or less. It may contain.

  Of the oxides of at least one metal selected from titanium, zirconium, indium, zinc, tin, and antimony, titanium and zirconium are preferable.

  The surface of the inorganic particles used in the antiglare hard coat layer is preferably subjected to silane coupling treatment or titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.

  The surface treatment agent may be used by mixing in the coating composition without coupling treatment in advance.

  When these inorganic particles are used, the addition amount is preferably 10 to 90%, more preferably 20 to 80%, particularly preferably 30 to 75% of the total mass of the antiglare hard coat layer. It is.

  Such inorganic particles have a particle size that is sufficiently smaller than the wavelength of light, so that scattering does not occur, and a dispersion in which the filler is dispersed in a binder polymer behaves as an optically uniform substance.

(Method for producing antiglare hard coat layer)
The antiglare hard coat layer is coated by applying a coating composition for forming an antiglare hard coat layer using a known method such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, or an ink jet method. Then, it is preferable to heat-dry and to perform UV curing treatment.

  The coating amount is suitably 0.1 to 40 μm, preferably 0.5 to 30 μm, as the wet film thickness.

  Moreover, as a dry film thickness, it is an average film thickness of 0.1-30 micrometers, Preferably it is 1-20 micrometers. Within this range, lack of hardness, deterioration of curling and brittleness, and deterioration of workability are prevented.

  As the light source for the UV curing treatment, any light source that generates ultraviolet rays can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used.

Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually 5 to 500 mJ / cm ² , preferably 5 to 150 mJ / cm ² .

  Moreover, when irradiating actinic radiation, it is preferable to carry out while applying tension | tensile_strength in the conveyance direction of a film, More preferably, it is performing applying tension | tensile_strength also in the width direction. The tension to be applied is preferably 30 to 300 N / m.

  The method for applying tension is not particularly limited, and tension may be applied in the transport direction on the back roll, or tension may be applied in the width direction or biaxial direction by a tenter. This makes it possible to obtain a film having further excellent flatness.

  The coating composition that forms the antiglare hard coat layer may contain a solvent. Examples of the organic solvent contained in the coating composition include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone). , Esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents may be appropriately selected or mixed for use.

  As the organic solvent, propylene glycol monoalkyl ether (1 to 4 carbon atoms of the alkyl group) or propylene glycol monoalkyl ether acetate (1 to 4 carbon atoms of the alkyl group) is preferable. Moreover, as content of an organic solvent, 5-80 mass% is preferable in a coating composition.

<Low refractive index layer>
In the present invention, an antireflection layer may be further coated on the antiglare hard coat layer, and in particular, a low refractive index layer is provided directly on the antiglare hard coat layer or via another layer. Is preferable in order to further reduce the reflected image and improve the visibility.

  The refractive index of the low refractive index layer is lower than the refractive index of the transparent film substrate as a support, and is preferably in the range of 1.30 to 1.45 at 23 ° C. and a wavelength of 550 nm.

  The film thickness of the low refractive index layer is preferably 5 nm to 0.5 μm, more preferably 10 nm to 0.3 μm, and even more preferably 30 nm to 0.2 μm.

  The low refractive index layer used in the present invention has hollow silica particles, silicone, and a binder as basic components.

  Furthermore, it is preferable to contain at least two types of silica particles including hollow silica particles, and the other one type of silica fine particles is colloidal silica, and the average particle size of the colloidal silica is 1 of the average particle size of the hollow silica particles. .1 to less than 20 times.

(Hollow silica particles)
The hollow silica particles whose inside is porous or hollow (hereinafter also simply referred to as hollow particles) will be described.

  The hollow particle is (I) a composite particle comprising a porous particle and a coating layer provided on the surface of the porous particle, or (II) having a cavity inside, and the content is a solvent, a gas or a porous substance It is a hollow particle filled with.

  The hollow particles are particles having cavities inside, and the cavities are surrounded by particle walls. The cavity is filled with contents such as a solvent, a gas, or a porous material used at the time of preparation.

  The average particle size of such hollow particles is 5 to 200 nm, preferably 10 to 70 nm. The particle size of the hollow particles is preferably monodispersed with a coefficient of variation of 1 to 40%.

  The average particle diameter can be measured from an electron micrograph taken with a scanning electron microscope (SEM) or the like. You may measure by the particle size distribution meter etc. which utilize a dynamic light scattering method, a static light scattering method, etc.

  The average particle diameter of the hollow particles to be used is appropriately selected according to the thickness of the transparent film of the low refractive index layer to be formed, and is preferably 2/3 to 1/10 of the film thickness of the transparent film.

  When the hollow particles are composite particles, the thickness of the coating layer of the composite particles or the thickness of the particle walls of the hollow particles is 1 to 20 nm, preferably 2 to 15 nm.

  In the case of composite particles, if the thickness of the coating layer is less than 1 nm, the particles may not be completely covered, and the coating liquid component can easily enter the composite particles to reduce the internal porosity. However, the effect of lowering the refractive index may not be obtained sufficiently.

  In addition, when the thickness of the coating layer exceeds 20 nm, the coating liquid component does not enter the inside, but the porosity (pore volume) of the composite particles is lowered and the effect of lowering the refractive index is sufficiently obtained. It may disappear.

  In the case of hollow particles, when the particle wall thickness is less than 1 nm, the particle shape may not be maintained, and even when the thickness exceeds 20 nm, the effect of lowering the refractive index may not be sufficiently exhibited. is there.

The coating layer of the composite particles or the particle wall of the hollow particles is preferably composed mainly of silica. Moreover, components other than silica may be contained, and specifically, Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , P ₂ O ₃ , Sb ₂ O _3. , MoO ₃ , ZnO ₂ , WO _{3 and the} like.

Examples of the porous particles constituting the composite particles include those made of silica, those made of silica and an inorganic compound other than silica, and those made of CaF ₂ , NaF, NaAlF ₆ , MgF, and the like.

Among these, porous particles made of a composite oxide of silica and an inorganic compound other than silica are particularly preferable. Examples of inorganic compounds other than silica include Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , P ₂ O ₃ , Sb ₂ O ₃ , MoO ₃ , ZnO ₂ and WO _3. 1 type or 2 types or more can be mentioned.

In such porous particles, the molar ratio MO _X / SiO ₂ when the silica is expressed by SiO ₂ and the inorganic compound other than silica is expressed in terms of oxide (MO _X ) is 0.0001 to 1.0, Preferably it is in the range of 0.001 to 0.3.

It is difficult to obtain a porous particle having a molar ratio MO _X / SiO ₂ of less than 0.0001. Even if it is obtained, a pore volume is small and particles having a low refractive index cannot be obtained.

In addition, when the molar ratio MO _X / SiO _{2 of} the porous particles exceeds 1.0, the ratio of silica decreases, so that the pore volume increases and it is difficult to obtain a low refractive index. is there.

  The pore volume of such porous particles is desirably in the range of 0.1 to 1.5 ml / g, preferably 0.2 to 1.5 ml / g. If the pore volume is less than 0.1 ml / g, particles having a sufficiently reduced refractive index cannot be obtained. If the pore volume exceeds 1.5 ml / g, the strength of the fine particles is lowered, and the strength of the resulting coating may be lowered. is there.

  In addition, the pore volume of such porous particles can be determined by a mercury intrusion method. Examples of the contents of the hollow particles include a solvent, a gas, and a porous substance used at the time of preparing the particles.

  The solvent may contain an unreacted particle precursor used when preparing the hollow particles, the catalyst used, and the like. Moreover, what consists of the compound illustrated by the said porous particle as a porous substance is mentioned.

  These contents may be composed of a single component or may be a mixture of a plurality of components.

  As a method for producing such hollow particles, for example, the method for preparing composite oxide colloidal particles disclosed in paragraphs [0010] to [0033] of JP-A-7-133105 is preferably employed.

  The content of the hollow particles of the present invention in the solid content in the low refractive index layer is preferably 10 to 40% by mass. Most preferably, it is 20-40 mass%. Solid content means what was left after drying and removing all the solvents used for application | coating.

  In the present invention, commercially available hollow particles can be used. Specific examples of commercially available particles include ELCOM V-8209 manufactured by Catalyst Kasei Kogyo Co., Ltd.

<Colloidal silica>
The colloidal silica preferably used in the present invention is obtained by dispersing silicon dioxide in water or an organic solvent in a colloidal form, and is spherical, acicular or beaded.

  The average particle size of the colloidal silica is 1.1 to less than 20 times the average particle size of the hollow particles, preferably 1.5 to 5.0 times. Therefore, the average particle diameter of colloidal silica is preferably in the range of 50 to 300 nm.

  The particle size of colloidal silica is preferably monodispersed with a coefficient of variation of 1 to 40%. The average particle diameter can be measured from an electron micrograph taken with a scanning electron microscope (SEM) or the like.

  Specifically, a micrograph (1000 times transmission mode) of the sample containing the particles was taken, and the diameter of the particles in the photograph was measured with an image processing device LUZEX-III (manufactured by Nireco), and the average The value was calculated as the average particle size.

  You may measure by the particle size distribution meter etc. which utilize a dynamic light scattering method, a static light scattering method, etc. However, when the ratio between the average particle size of colloidal silica and the average particle size of hollow particles is obtained, the same measurement method must be used.

  Such colloidal silica used in the present invention is commercially available, and examples thereof include the Snowtex series of Nissan Chemical Industries, the Cataloid-S series of Catalytic Chemical Industry, and the Rebacil series of Bayer.

  Also, beaded colloidal silica in which primary particles of cation-modified with alumina sol or aluminum hydroxide are bonded in a bead shape by bonding the particles with divalent or higher metal ions.

  There are beaded colloidal silicas such as SNOWTEX-AK series, SNOWTEX-PS series, SNOWTEX-UP series of Nissan Chemical Industries.

  The content of the colloidal silica in the low refractive index layer is preferably 30 to 60% by mass with respect to the solid content in the low refractive index layer.

  In order to obtain the effect of lowering the refractive index, it is preferably 30% by mass or more, and when it exceeds 40% by mass, the binder component is decreased and the film strength becomes insufficient.

  The content ratio of the hollow particles and the colloidal silica in the low refractive index layer is selected from the viewpoint of the reflectance reduction effect and the surface hardness, but is preferably 1: 0.1 to 10, more preferably 1: 0.8 to 5. preferable.

(binder)
It is preferable that a low refractive index layer contains 5-80 mass% binder in the whole low refractive index layer. The binder has a function of binding hollow particles, colloidal silica, and silicone to form a structure of a low refractive index layer including voids.

  The usage-amount of a binder is adjusted so that the intensity | strength of a low refractive index layer can be maintained, without filling a space | gap. The binder itself is a compound having a low refractive index, and is an organosilane represented by the following general formula (1), a hydrolyzate thereof, or a condensate thereof.

General formula (1) Si (X1) ₄
In the formula, X1 is a hydroxyl group or a hydrolyzable group, specifically an alkoxy group, preferably an alkoxy group having 1 to 4 carbon atoms. As specific compound compounds, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane and the like are preferably used.

  The low refractive index layer may also contain an organosilane represented by the following general formula (2) or a condensate thereof as a binder.

Formula (2) (R) mSi (X2) 4-m
R represents a group other than a hydroxyl group or a hydrolyzable group. X2 represents a hydroxyl group or a hydrolyzable group. m represents an integer of 1 to 4.

  Examples of the organosilane represented by the general formula (2) include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxy Silane, γ-chloropropyltriacetoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidylo Xylpropyltriethoxysilane, γ- (β-glycidyloxyethoxy) propyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane Γ-acryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane and β-cyanoethyltriethoxysilane.

  Also, dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, γ-glycidyloxypropylmethyldiethoxysilane, γ-glycidyloxypropylmethyldimethoxysilane, γ-glycidyloxypropylphenyldiethoxysilane Γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-acryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyldiethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-methacryloyloxypropylmethyldi Ethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-aminop Examples include propylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, methylvinyldimethoxysilane, and methylvinyldiethoxysilane.

  Among these, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, γ-acryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyltrimethoxysilane having a double bond in the molecule Γ-acryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyldiethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-methacryloyloxypropylmethyldiethoxysilane, methylvinyldimethoxysilane and methylvinyldiethoxysilane Preferably, γ-acryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyl Propyl methyl dimethoxy silane, .gamma. acryloyloxypropyl diethoxysilane, .gamma.-methacryloyloxy propyl methyl dimethoxy silane and .gamma.-methacryloyloxy propyl methyl diethoxy silane is particularly preferred.

  Two or more types may be used in combination. In addition to the organosilanes shown above, other organosilanes may be used. Other organosilanes include alkyl esters of orthosilicates (eg, methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, i-propyl orthosilicate, n-butyl orthosilicate, sec-butyl orthosilicate, orthosilicate t. -Butyl) and hydrolysates thereof.

  Examples of other binders for the low refractive index layer include polyvinyl alcohol, polyoxyethylene, polymethyl methacrylate, polymethyl acrylate, diacetyl cellulose, triacetyl cellulose, nitrocellulose, polyester, and alkyd resin.

  In the present invention, the organosilane of the general formula (2) is preferably used in the range of 1 to 50% by mass, and in the range of 5 to 40% by mass with respect to the organosilane of the general formula (1). Is particularly preferred.

(Other additives)
<Fluorosurfactant>
The low refractive index layer preferably contains a fluorinated surfactant. It is effective in reducing coating unevenness and improving the antifouling property of the film surface.

  Fluorosurfactants include perfluoroalkyl group-containing monomers, oligomers, and polymers as the core, and include derivatives such as polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, and polyoxyethylene. It is done.

  Commercially available products may be used as the fluorosurfactant, for example, Surflon “S-381”, “S-382”, “SC-101”, “SC-102”, “SC-103”, “SC-104”. (All manufactured by Asahi Glass Co., Ltd.), Florard “FC-430”, “FC-431”, “FC-173” (all manufactured by Fluorochemical-Sumitomo 3M), Ftop “EF352”, “EF301”, “EF303” (both manufactured by Shin-Akita Kasei Co., Ltd.), Schwego Fluer “8035”, “8036” (both manufactured by Schwegman), “BM1000”, “BM1100” (all manufactured by BM Himmy) , MegaFuck “F-171”, “F-470” (both manufactured by Dainippon Ink & Chemicals, Inc.), and the like.

  The fluorine content of the fluorosurfactant in the present invention is 0.05 to 2% by mass, preferably 0.1 to 1% by mass. The above-mentioned fluorosurfactants can be used alone or in combination of two or more, and can be used in combination with other surfactants.

(Formation of a low refractive index layer)
For formation of the low refractive index layer of the present invention, generally known methods can be used as they are, and a coating solution containing an organosilane hydrolyzate is applied and dried.

  Specifically, water or a hydrophilic organic solvent such as methanol, ethanol, or acetonitrile is dissolved in the organosilane so that water or an organometallic compound and water can be easily mixed. A decomposition catalyst is added to hydrolyze and condense the organosilane.

  When GPC measurement has progressed to a certain degree of hydrolysis, the hollow particles are mixed to obtain a low refractive index layer coating solution, and then the GPC is measured by condensation through a process of continuing hydrolysis. After the increase in molecular weight and the degree of crosslinking are observed, this is applied on the antiglare hard coat layer and dried to form a low refractive index layer.

  In the present invention, the hollow particles are coated by coating the organosilane represented by the general formula (1) such as tetraethoxysilane by hydrolysis and subsequent condensation to produce a low-condensate having a predetermined molecular weight. It has the process of mixing with a liquid and continuing hydrolysis and condensation further.

  A predetermined molecular weight means that the weight average molecular weight of styrene conversion by GPC measured on the following conditions is 500-1000. In the process of continuing further hydrolysis and condensation, the weight average molecular weight is adjusted to be more than 1000 and 10,000 or less.

<GPC measurement conditions>
In the weight average molecular weight measurement method by GPC, the sample is diluted with THF so that the sample solid content concentration becomes 0.8% by mass, and the measurement is performed at a column temperature of 25 ° C. under the following conditions.
Column: Tosoh Corporation TSKgelG5000HXL-TSKgelG2000HXL
Eluent: THF
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0 ml / min
Detection: RI Model 504 (manufactured by GL Sciences)
Sample concentration: 0.8%
Standard sample / calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corp.) Mw = 100000 to 500 samples are used.

  When the hollow particles are mixed into the coating solution immediately after the start of hydrolysis, or when the organosiloxane is reactive as represented by the general formula (2), the silicone on the surface of the hollow particles as in the present invention There is almost no action that suppresses adsorption.

  On the other hand, the organosilane represented by the general formula (2) is mixed with a low condensate such that the weight average molecular weight of the organosilane represented by the general formula (1) is 500 to 1000, so that Contributes to film strength.

<Other layers>
(Antistatic layer)
An antistatic layer can also be provided on the antiglare hard coat film of the present invention. The position at which the antistatic layer is provided is not particularly limited, but is preferably provided between the transparent film substrate and the antiglare hard coat layer.

  The antistatic layer cures zinc antimonate sol, tin phosphate sol, tin oxide sol, etc. via a crosslinking reaction or the like by irradiation with active rays such as ultraviolet rays or electron beams according to the method for producing an antiglare hard coat layer. It is preferable to contain in resin.

(Back coat layer)
In the antiglare hard coat film of the present invention, a back coat layer may be provided on the surface opposite to the side provided with the antiglare hard coat layer.

  The back coat layer is provided in order to correct curl caused by providing the antiglare hard coat layer. That is, the degree of curling can be balanced by imparting the property of being rounded with the surface on which the backcoat layer is provided facing inward.

  The backcoat layer is preferably applied also as an antiblocking layer, and in this case, particles of an inorganic compound or an organic compound are added to the backcoat layer coating composition in order to provide an antiblocking function. Is preferred.

  You may surface-treat before apply | coating each above-mentioned layer. Examples of the surface treatment method include a cleaning method, an alkali treatment method, a flame plasma treatment method, a high frequency discharge plasma method, an electron beam method, an ion beam method, a sputtering method, an acid treatment, a corona treatment method, and an atmospheric pressure glow discharge plasma method. It is done.

<Polarizing plate>
A polarizing plate using the antiglare hard coat film of the present invention will be described.

  The polarizing plate can be produced by a general method. At least a polarizing film produced by subjecting the antiglare hard coat film of the present invention to an alkali saponification treatment on the back side of the antiglare antireflection film and immersing and stretching the treated antiglare hard coat film in an iodine solution. It is preferable to attach to one surface using a completely saponified polyvinyl alcohol aqueous solution.

  With respect to the antiglare hard coat film of the present invention, the in-plane retardation (Ro) and the thickness direction retardation (Rt) of the polarizing plate protective film used on the other surface can be appropriately selected.

  The retardation values Ro and Rt can be measured using an automatic birefringence meter. For example, using KOBRA-21ADH (manufactured by Oji Scientific Instruments Co., Ltd.), the wavelength can be obtained at 590 nm in an environment of a temperature of 23 ° C. and a humidity of 55% RH.

  As a polarizing plate protective film used on the back side, as a commercially available cellulose ester film, KC8UX2MW, KC4UX, KC5UX, KC4UY, KC8UY, KC12UR, KC4UEW, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC4FR-1, KC4F-1, -2, KC4HR, KC4KR (manufactured by Konica Minolta Opto Co., Ltd.) and the like are preferably used.

  The polarizing film, which is the main component of the polarizing plate, is an element that transmits only light having a polarization plane in a certain direction. A typical polarizing film known at present is a polyvinyl alcohol polarizing film, which is a polyvinyl alcohol film. There are ones in which iodine is dyed on a system film and ones in which a dichroic dye is dyed, but it is not limited to this.

  As the polarizing film, a polyvinyl alcohol aqueous solution is formed and dyed by uniaxially stretching or dyed, or uniaxially stretched after dyeing, and then preferably subjected to a durability treatment with a boron compound.

  A polarizing film having a thickness of 5 to 30 μm, preferably 8 to 15 μm, is preferably used. On the surface of the polarizing film, one side of the antireflection film of the present invention is bonded to form a polarizing plate.

  It is preferably bonded with an aqueous adhesive mainly composed of completely saponified polyvinyl alcohol or the like.

<Liquid crystal display device>
The configuration of the liquid crystal display device of the present invention is a liquid crystal display device having a polarizing plate having a structure in which a polarizer is sandwiched between two polarizing plate protective films on both sides of a liquid crystal cell in which a blue phase liquid crystal medium is sealed. By incorporating the antiglare hard coat film or the antiglare antireflection film surface of the present invention on the viewing surface side of the display device, the display device of the present invention having excellent visibility can be produced. The polarizing plate attached to the backlight side of the liquid crystal cell and the polarizing plate protective film are not particularly limited, but use a polarizing plate in which the commercially available cellulose ester film is bonded to both sides of the polarizer. It is preferable to do.

  The blue phase liquid crystal display device using the antiglare hard coat film of the present invention greatly improves contrast, particularly in bright places. Other than that, it is a liquid crystal display device capable of high-speed display with excellent visibility because the uneven color of reflected light of the antiglare hard coat layer is remarkably small, and the reflectance is low and the flatness is excellent. .

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
<Preparation of transparent film substrate>
(Particle dispersion)
Particles X having an average particle size of 0.2 μm or more and less than 2.0 μm and having a refractive index difference of 0.02 or more and 0.3 or less with respect to the transparent film substrate Table 1 and Table 2 After stirring and mixing for a minute, dispersion was performed to prepare a particle dispersion.

Particle X (average particle size, refractive index)
X1: Chemisnow MP (0.5 μm, 1.49)
X2: Seahoster KE-P10 (0.12 μm, 1.43)
X3: Seahoster KE-P150 (1.58 μm, 1.43)
X4: Fluorine-containing polymethyl methacrylate (0.55 μm, 1.42)
(F-191, manufactured by Nippon Paint Co., Ltd.)
X5: Eposter S12 (1.5 μm, 1.66)
X6: Seahoster KE-P250 (2.50 μm, 1.43)
(Preparation of inline additive solution 1)
Tinuvin 109 (manufactured by Ciba Japan Co., Ltd.) 11 parts by mass Tinuvin 171 (manufactured by Ciba Japan Co., Ltd.) 5 parts by mass Methylene chloride 100 parts by mass Dissolved and filtered. Furthermore, after adding 6 parts by mass of cellulose acetate propionate (acetyl group substitution degree 1.9, propionyl group substitution degree 0.8) with stirring and further stirring for 60 minutes, a polypropylene wind cartridge of Advantech Toyo Co., Ltd. Filtration was performed using a filter TCW-PPS-1N to prepare an in-line additive solution 1.

(Preparation of dope solution 1)
Cellulose triacetate 100 parts by mass (Mn = 95000, Mw = 323000, Mw / Mn = 3.4, acetyl group substitution degree 2.9, refractive index 1.48)
Trimethylolpropane tribenzoate (aliphatic polyhydric alcohol ester)
5.0 parts by weight Ethylphthalyl ethyl glycolate 5.5 parts by weight Methylene chloride 440 parts by weight Ethanol 40 parts by weight The above was put into a sealed container, heated and stirred, and dissolved completely. Azumi filter paper No. No. 24 was used to sufficiently remove foreign matters and the like by filtration in advance. Here, 50 parts by mass of the particle dispersion was added and mixed to prepare a dope solution 1. Add 2 parts by mass of the filtered inline additive 1 to 100 parts by mass of the dope solution 1 and mix thoroughly with an inline mixer (Toray static type in-pipe mixer Hi-Mixer, SWJ). After removing the foreign matter, the belt was cast evenly on a stainless steel band support at a temperature of 35 ° C. and a width of 1800 mm using a belt casting apparatus.

  With the stainless steel band support, the solvent was evaporated until the residual solvent amount became 120%, and then peeled off from the stainless steel band support. The peeled cellulose ester web was evaporated at 40 ° C. and slit to 1650 mm width.

  In Samples 1 to 8, irregularities were given by the following mold.

  A B surface of the film (on the stainless steel band support) with a film containing a solvent sandwiched between a roll provided with a casting mold (centerline average surface roughness Ra = 1 μm, unevenness interval Sm = 20 μm) and an unevenness forming part composed of a back roll. The side that was in contact is the B side, and the opposite side is the A side.) A hot roll with a mold is pressed on the side, a back roll is placed on the A side, and the two rolls are passed through Unevenness was formed on the B surface side.

  In the vicinity of the concavo-convex portion, a static elimination wire was installed to suppress film charging.

  After forming the irregularities, drying is completed while transporting the heating zone at 110 ° C. and 120 ° C. with a number of rolls, slitting to a width of 1400 mm, winding at both ends of the film with a width of 15 mm and an average height of 10 μm, A cellulose ester film was obtained.

  In Samples 9 to 17, particles Y having an average particle size of 2.0 μm or more and less than 10.0 μm were added to the dope, and the stretching treatment described below or in Tables 1 and 2 was performed.

  In Sample 16, two types of dope solutions were co-cast on a stainless steel belt so as to have a total film thickness of 80 μm so as to have a two-layer structure as shown in Tables 1 and 2. At that time, the stainless steel belt side was adjusted to 60 μm. The particles Y were contained on the side opposite to the stainless steel belt side.

  It extended | stretched 1.10 time at 120 degreeC in TD direction (direction orthogonal to the conveyance direction of a film) with the tenter. The residual solvent amount when starting stretching with a tenter was 30% (poor solvent ratio was 10% by mass or more).

  The draw ratio in the MD direction (the same direction as the film transport direction) immediately after peeling calculated from the rotational speed of the stainless steel band support and the operating speed of the tenter was 1.00 times. The residual solvent amount of the wound cellulose ester film was 0.1%, the average film thickness was 80 μm, and the winding number was 3000 m.

Particle Y
Y1: Eposter MA1002 (2.5 μm)
Y2: Eposta MA1004 (4.5 μm)
Y3: Eposta MA1006 (6μm)
Y4: Epostor GPH100 (10 μm)
Y5: Eposta MA1015 (13 μm)
<Preparation of antiglare hard coat layer>
In the following manner, the following antiglare hard coat layer and back coat layer were provided on the transparent film substrate to prepare Example Samples and Comparative Example Samples.

The transparent film substrate is die-coated with the coating composition 1 for an antiglare hard coat layer, dried at 80 ° C., and then irradiated with 0.30 J / cm ² of ultraviolet light with a high-pressure mercury lamp. An antiglare hard coat layer was applied so as to have a thickness of 5 μm. The refractive index of only the transparent resin was 1.49.

  On the surface opposite to the antiglare hard coat layer, the following coating solution 1 for back coat layer is die-coated so as to have a wet film thickness of 6 μm, and a back coat layer is provided to prevent the cellulose ester film from being coated. An antiglare hard coat film example sample 1 provided with a dazzling hard coat layer and a back coat layer was prepared.

  The contents changed depending on the sample are shown in Tables 1 and 2.

(Coating composition 1 for antiglare hard coat layer)
Acetone 35 parts by mass Ethyl acetate 35 parts by mass Cyclohexanone 15 parts by mass Toluene 15 parts by mass Pentaerythritol triacrylate 30 parts by mass Pentaerythritol tetraacrylate 45 parts by mass Urethane acrylate 25 parts by mass (trade name U-4HA manufactured by Shin-Nakamura Chemical Co., Ltd.)
1-hydroxycyclohexyl-phenyl-ketone 8 parts by mass (Irgacure 184, manufactured by Ciba Japan Co., Ltd.)
2-Methyl-1- [4- (methylthio) phenyl] -2-monophorinopropan-1-one (Irgacure 907, manufactured by Ciba Japan Co., Ltd.) 8 parts by mass The above antiglare hard coat layer coating composition In addition, as shown in Table 1, the product 1 is based on 100 parts by mass of the resin.
Particle 1: When adding particle A 5 parts by mass Particle 2: When adding particle B 2 parts by mass were added.

  The other particles used in Examples and Comparative Examples are as follows.

Particle A: Fluorine-containing polymethyl methacrylate particles (F-191 average particle size 0.55 μm, refractive index 1.42 manufactured by Nippon Paint Co., Ltd.)
Particle B: Silica particle (Seahoster KE-P100, average particle diameter 1.10 μm, refractive index 1.43, manufactured by Nippon Shokubai Co., Ltd.)
(Coating composition 1 for back coat layer)
Acetone 30 parts by weight Ethyl acetate 45 parts by weight Isopropyl alcohol 10 parts by weight Diacetylcellulose 0.6 part by weight Silica particles having an average particle diameter of 16 nm 2% acetone dispersion 0.2 part by weight <Characteristic evaluation as liquid crystal display device>
Using the antiglare hard coat film prepared above, a polarizing plate was prepared according to the following procedure, and then a liquid crystal display device using the polarizing plate was prepared.

<Preparation of polarizing plate>
A polarizing plate using each antiglare hard coat film as a polarizing plate protective film was prepared as follows.

  A 120 μm-thick long roll polyvinyl alcohol film was immersed in 100 parts by mass of an aqueous solution containing 1 part by mass of iodine and 4 parts by mass of boric acid, and stretched 5 times in the transport direction at 50 ° C. to prepare a polarizer.

  Next, using the adhesive on one side of the polarizer, the antiglare hard coat film sample 1 produced above was subjected to saponification treatment and then bonded.

  Further, Konica Minolta Tack KC4UE (Ro = 0 nm, Rt = 0 nm) manufactured by Konica Minolta Opto Co., Ltd., which is a polarizing plate protective film subjected to saponification treatment, is bonded to the other surface of the polarizer and dried to produce a polarizing plate P1. did. In the same manner, polarizing plates P2 to P17 were produced using antiglare hard coat film samples 2 to 17.

  Moreover, the backlight side polarizing plate which uses Konica Minolta Opto Co., Ltd. product Konica Minolta Tack KC4UE as the polarizing plate protective films on both sides was similarly prepared.

(Production of liquid crystal display device)
(Preparation of liquid crystal display element D-1)
JC1041 (mixed liquid crystal, manufactured by Chisso Corporation) was 48.2 mol%, 5CB (4-cyano-4'-pentyl biphenyl, nematic liquid crystal, manufactured by Merck & Co., Inc.) was 47.4 mol%, ZLI-4572 (chiral dopant, Merck). A substance a mixed with 4.4 mol% of a product of the company) is prepared.

continue,
Substance a 95.8 mass%
UCL001 (manufactured by DIC) 3.0% by mass
RM257 (Merck diacrylate monomer) 1.0 mass%
DMPAP (manufactured by Aldrich, 2,2-dimethoxy-2-pentylacetophenone)
0.2% by mass
The mixture was mixed in the above ratio and poured between two transparent glasses. However, of the two sheets of glass, the first and second electrodes for each pixel were formed in accordance with Embodiment 1 of JP-A-2005-208609 and provided in advance.

  The liquid crystal medium sandwiched between the glass substrates was held at 58 ° C., and irradiated with ultraviolet rays in that state, and the blue phase was stabilized with a photopolymerized polymer, to obtain a liquid crystal display element D-1. As a result of measuring the reflection spectrum of D-1, R400 / R550 = 12.5.

  Each of the prepared polarizing plates is bonded to a liquid crystal cell so that the antiglare hard coat film of the present invention is on the viewing side, and the backlight side polarizing plate is bonded to the opposite side of the liquid crystal cell. The display characteristics of the invention were evaluated.

  In addition, both polarizing plates were arrange | positioned so that the absorption axis of a polarizer might be in the state of crossed Nicols where it orthogonally crossed.

<Evaluation>
(Haze of transparent film substrate)
About each of the produced transparent film base materials, one sample, which was conditioned for 24 hours in an air-conditioned room at 23 ° C. and 55% RH, in accordance with JIS K-7136, a haze meter (NDH2000 type, Nippon Denshoku Industries Co., Ltd.) ).

The internal haze and surface haze of the transparent film substrate were measured by the following procedure.
(1) A polyethylene terephthalate film with an adhesive having an acrylic adhesive applied on one side is attached to the surface of a transparent film substrate, and the total haze value H0 is measured for the whole attached film.
(2) Separately, the total haze value Ht of only the polyethylene terephthalate film with an adhesive to which an acrylic adhesive was applied was measured, and the value obtained by subtracting Ht from the previously measured H0 was defined as the internal haze value Hi. (Hi = H0-Ht)
(3) A value obtained by subtracting the internal haze (Hi) calculated in (3) from the total haze (H) measured in (1) above was calculated as the surface haze (Hs) of the film. (Hs = H-Hi)
(Surface haze of antiglare hard coat layer)
The surface haze was measured according to the following procedure.

The surface haze is measured by using a haze meter (NDH2000 type, manufactured by Nippon Denshoku Industries Co., Ltd.) according to JIS K-7136 for each sample conditioned for 24 hours in an air-conditioned room at 23 ° C. and 55% RH. .
(1) The total haze value (H) of the film is measured according to JIS-K7136.
(2) A few drops of silicone oil are added to the front and back surfaces of the antiglare hard coat layer side of the film, and sandwiched from the front and back using two 1 mm thick glass plates (micro slide glass product number S9111, manufactured by MATSANAMI) Then, the two glass plates and the film were optically closely adhered, the haze was measured with the surface haze removed, and the haze was measured by sandwiching only the silicone oil between two separately measured glass plates. Is calculated as the internal haze (Hi) of the film.
(3) A value obtained by subtracting the internal haze (Hi) calculated in (2) from the total haze (H) measured in (1) above is calculated as the surface haze (Hs) of the film.

(contrast)
The contrast of the liquid crystal display device was measured by EZ-contrast manufactured by ELDIM. Contrast was calculated for white display and black display of the liquid crystal cell.

Evaluation rank of contrast ○: 850 or more Δ: 700 or more, less than 850 ×: less than 700 (Visibility in a bright place)
A liquid crystal display device was installed in the station premises during the daytime to evaluate the visibility of the screen.

○: Black appears to be crisp and clear △: There is no blackness and the sharpness is slightly low ×: There is no blackness and the sharpness is low The composition of the antiglare hard coat film and the result of evaluation Shown in Tables 1 and 2.

  As described in Tables 1 and 2, the liquid crystal display device using the antiglare hard coat film of the present invention exhibited excellent characteristics in contrast and visibility in a bright place.

Example 2
<Preparation of antiglare antireflection film>
The following low refractive index layer coating solution 1 is die coated on the antiglare hard coat layers of the antiglare hard coat films 1 to 17 produced in Example 1, and dried at 50 ° C. for 60 seconds. under .1% atmosphere, irradiation with ultraviolet rays of 300 mJ / cm ² by a high pressure mercury lamp, a low refractive index layer is provided so as to further film thickness for 60 seconds heat treatment at 130 ° C. is 100 nm, antiglare and antireflection Films 1 to 17 were produced.

  The antiglare antireflection film 17 was subjected to a surface treatment at 45 ° C. for 2 minutes with a 1N aqueous sodium hydroxide solution before application of the low refractive index layer.

(Low refractive index layer coating solution 1)
Propylene glycol monomethyl ether 437 parts by mass Isopropyl alcohol 347 parts by mass Acetic acid 3.00 parts by mass Hydrolyzate B (converted to 8.6% solid content) 165 parts by mass γ-methacryloxypropyltrimethoxysilane (KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.) )
1.25 parts by mass α-butyl-ω- [3- (2,2-bis (hydroxymethyl) butoxy) propyl] polydimethylsiloxane (FM-DA21 manufactured by Chisso Corporation) 1.05 parts by mass Aluminum ethyl acetoacetate Diisopropylate (ALCH manufactured by Kawaken Fine Chemical Co., Ltd.), diluted with isopropyl alcohol (solid content 10%) 2.25 parts by mass FZ-2207 (10% propylene glycol monomethyl ether solution, manufactured by Toray Dow Corning Co.) 2.40 masses Part <Preparation of hydrolyzate B>
Ethanol and an acetic acid aqueous solution were added to 147 g of tetraethoxysilane (trade name: KBE04, manufactured by Shin-Etsu Chemical Co., Ltd.) to give 500 g, and the mixture was stirred at room temperature (25 ° C.) for 15 hours to prepare a hydrolyzate. The weight average molecular weight Mw of the condensate of silane was 800.

  At this point, 588 g of ELCOM KO-1025SIV (Catalyst Chemical Industries, Ltd., isopropyl alcohol-dispersed hollow silica particles, solid content 20%) was mixed and stirred for another 2 hours. Finally, the solvent was distilled off to adjust the concentration. A hydrolyzate B was prepared by adjusting.

  Simultaneously with mixing the hollow silica particles of the hydrolyzate B, α-butyl-ω- [3- (2,2-bis (hydroxymethyl) butoxy) propyl] polydimethylsiloxane (FM-DA21 manufactured by Chisso Corporation) 1.05 mass parts was also mixed.

  A polarizing plate and a liquid crystal display device were produced using the antiglare antireflection films 1 to 17 in the same manner as in Example 1, and the same evaluation as the contrast in Example 1 and the visibility in a bright place was performed. It has been found that the liquid crystal display device using the antiglare antireflection film of the invention further improves the contrast and visibility in a bright place. Further, the antiglare antireflection film 17 that had been saponified before the low refractive index layer was applied was not easily scratched during polarizing plate processing.

It is the schematic of the uneven | corrugated surface forming apparatus using the mold roll used for this invention.

Explanation of symbols

F film 1 Dice 2 Casting belt 3 Uneven surface forming mold roll 4 Back roll 5 Tenter 6 Film drying device 7 Winding roll 10 Static electricity removing device

Claims (2)

In a liquid crystal display device having polarizing plates on both sides of a liquid crystal cell, the liquid crystal cell exhibits optical isotropy when an electric field is not applied, and exhibits optical anisotropy according to the magnitude of the applied electric field. A liquid crystal medium to be expressed is enclosed, and the polarizing plate has a structure in which a polarizer is sandwiched between two polarizing plate protective films, and at least one of the polarizing plate protective films includes a transparent film substrate and a hard film. The antiglare hard coat film has a coat layer, the internal haze of the transparent film substrate is 10 to 60%, and the surface haze of the hard coat layer is 1.0 to 15%. A liquid crystal display device. The liquid crystal display device according to claim 1, wherein a low refractive index layer is provided directly or via another layer on the antiglare hard coat film.

Images