JP5167812B2 - Optical film processing method, optical film processing apparatus, and optical film manufacturing method - Google Patents

Description

  The present invention relates to a method of processing an optical film and an optical film with improved coating failures such as horizontal unevenness, coating streaks, and tailing that are likely to occur when a functional layer such as an antireflection layer is applied on a long film. In particular, the present invention relates to an optical film processing method, an optical film processing apparatus, and an optical film manufacturing method for improving lateral unevenness.

  In recent years, the development of thin and light notebook PCs and thin and large-screen TVs has progressed, and accordingly, the protective film for polarizing plates used in display devices such as liquid crystal display devices has become increasingly thinner, larger and higher performance. The demand for is getting stronger. In addition, liquid crystal image display devices such as computers and word processors (liquid crystal displays, etc.) having an optical film provided with an anti-reflection layer for improving visibility, or provided with an anti-glare layer with an uneven surface to scatter reflected light Has come to be used a lot.

  Various types of antireflection layers and performance improvements are made depending on the application, and various front plates with these functions are bonded to the polarizers of liquid crystal displays, etc., so that the antireflection layer can be used to improve visibility. A method of imparting a function is used. (For example, refer to Patent Document 1.) These optical films used as the front plate are often provided with an antireflection layer formed by coating, vapor deposition, sputtering, or the like.

  In addition, a thinner film is required for a thin display device, or a wide optical film is required for a large screen. In particular, optical films with excellent flatness are required for large screens, but conventional optical films are not particularly wide and thin films with excellent flatness cannot be obtained, and a large area is sufficient for scratch resistance. I couldn't get anything.

In particular, when a metal oxide layer is applied as an antireflection layer, uneven coating tends to occur, and improvement thereof has been demanded. In particular, when the width of the base film is 1.4 m or more, coating unevenness is extremely likely to occur, and improvement of coating unevenness such as horizontal unevenness, coating stripes, and tailing has been demanded.
JP 2002-182005 A

  An object of the present invention is to provide a method for processing an optical film in which coating failures such as horizontal unevenness, coating stripes, and tailing that are likely to occur when a functional layer such as an antireflection layer is applied on a long film, and An object of the present invention is to provide an optical film processing apparatus.

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

  (Structure 1) In the processing method of the optical film which removes the liquid on the surface of a long film after rubbing the conveyed long film with the elastic body wet with the liquid, the static friction coefficient of the surface of the elastic body is 0. The processing method of the optical film which is 2 or more and 0.9 or less.

  (Configuration 2) The method for processing an optical film according to Configuration 1, wherein the elastic body is a surface-modified rubber.

  (Structure 3) The processing method of the optical film of the structure 1 or the structure 2 which has a means which detects the width | variety edge part position of the said elongate film, and adjusts a conveyance position.

  (Structure 4) The processing method of the optical film of any one of the structures 1 to 3, wherein the temperature of the liquid is 30 ° C. or more and 100 ° C. or less, and the temperature of the elastic body is 30 ° C. or more and 100 ° C. or less.

  (Structure 5) The processing method of the optical film according to any one of structures 1 to 4, wherein the elastic body is rubbed while pressing the back surface of the long film.

  (Structure 6) The optical film processing method according to any one of structures 1 to 5, wherein a surface to be processed of the long film is wetted in advance with a liquid before rubbing with the elastic body wetted with the liquid.

  (Structure 7) The processing method of the optical film of the structure 6 which wets this to-be-processed surface by the means to supply a liquid to the to-be-processed surface of the said elongate film.

  (Structure 8) The processing method of the optical film of the structure 6 or the structure 7 which has a means to supply a liquid between the said elongate film and the said elastic body.

  (Structure 9) The method for processing an optical film according to any one of Structures 1 to 8, wherein a time during which the treated surface of the long film is wet with a liquid is 2 seconds or longer and 60 seconds or shorter.

  (Structure 10) The processing method of the optical film of any one of the structures 1-9 which the film thickness of the said elongate film is 30 micrometers or more and 70 micrometers or less.

  (Structure 11) An optical film comprising an elastic body rubbing means for rubbing a long film being conveyed with an elastic body wetted with a liquid, and a liquid removing means for removing the liquid on the surface of the long film after rubbing. In this processing apparatus, the static friction coefficient of the surface of the elastic body is from 0.2 to 0.9.

  (Structure 12) The processing apparatus of the optical film of the structure 11 which has a means to detect the width | variety edge part position of the said elongate film, and to adjust a conveyance position.

  (Structure 13) Structure 11 having liquid temperature adjusting means for adjusting the liquid temperature to 30 ° C. or higher and 100 ° C. or lower and elastic body temperature adjusting means for adjusting the temperature of the elastic body to 30 ° C. or higher and 100 ° C. or lower. Or the processing apparatus of the optical film of the structure 12.

  (Structure 14) The processing apparatus of the optical film of any one of the structures 11-13 which has a means to pressurize the back surface of the said long film.

  (Structure 15) The optical film processing apparatus according to any one of Structures 11 to 14, further comprising a film wetting unit that wets a surface to be processed of the long film with a liquid in advance before the elastic body rubbing unit. .

  (Structure 16) The optical film processing apparatus according to structure 15, wherein the film wetting means is means for supplying a liquid to the surface to be processed of the long film.

  (Arrangement 17) The optical film processing apparatus according to Arrangement 15 or Arrangement 16, wherein the film wetting means is means for supplying a liquid between the long film and the elastic body.

  (Structure 18) The optical film processing apparatus according to any one of Structures 11 to 17, wherein a processing time from the start of wetting by the film wetting means to the end of removal by the liquid removing means is 2 seconds to 60 seconds. .

  (Arrangement 19) An optical film manufacturing method in which a functional layer is coated on the treated surface of the long film after being processed in the optical film processing method according to any one of Arrangements 1 to 10.

(Structure 20) The method for producing an optical film according to Structure 19, wherein the functional layer is an antireflection layer or an actinic radiation curable resin layer.

(Structure 21) The method for producing an optical film according to Structure 20, wherein the long film is a cellulose ester film and the liquid is water.

It is a schematic diagram which shows the whole apparatus which rubs one surface of the elongate film conveyed with the elastic body wetted with the liquid of this invention. It is a schematic diagram which shows another example of the apparatus which rubs one surface of the elongate film conveyed with the elastic body wetted with the liquid of this invention. It is an example of the method of measuring the static friction coefficient of the elastic body which concerns on this invention. It is an example of the rinse nozzle used for this invention. It is a figure which shows the washing | cleaning method of the elastic body 1 which concerns on this invention. It is a schematic diagram which shows the installation location of the air nozzles 5 and 6 of this invention, and the blowing direction of air.

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

  As a result of diligent research, the present inventor has rubbed the long film being transported with an elastic body wetted with a liquid and then removed the liquid on the surface of the long film. The horizontal unevenness that is likely to occur when a functional layer such as an antireflection layer is applied on the long film by the optical film processing method, wherein the static friction coefficient is 0.2 or more and 0.9 or less. The present inventors have found a surprising effect that application failures such as application stripes are improved, and have come to achieve the present invention. In addition, it is preferable to further perform the atmospheric pressure plasma treatment described in US Pat. No. 6,512,562 before or after the treatment of the optical film of the present invention.

  The inventors rub the long film with an elastic body wetted with a liquid, and then remove the liquid adhering to the surface of the long film, thereby removing wrinkles, strain, distortion, etc. of the long film. It was found that the flatness of the long film can be corrected and the coating failure when applying a functional layer such as an antireflection layer via a hard coat layer can be improved. is there.

  Furthermore, it has means for detecting the width end position of the long film and adjusting the transport position, the liquid is 30 ° C. or more and 100 ° C. or less, and the temperature of the elastic body is 30 ° C. or more and 100 ° C. or less, Add the fact that only the treated surface of the long film is pre-painted with liquid before rubbing with the elastic body while pressing the back of the long film, or before rubbing with the elastic body wet with the liquid It has been found that the effect of the present invention is further enhanced.

  The present invention will be described in detail below.

  The present invention will be described with reference to FIGS. However, the present invention is not limited to these.

  FIG. 1 is a schematic view showing an entire apparatus for rubbing one surface of a long film conveyed by an elastic body wetted with a liquid according to the present invention. The long film F is guided by the guide roller 2 and rubbed by the driven elastic body 1 (elastic body roll). The driven elastic body 1 is always kept wet by the liquid 4 stored in the liquid tank 3. After the long film F is rubbed by an elastic body, it is conveyed by the guide roller 2 ′, and excess liquid and foreign matters are blown off by the air nozzle 6 by blowing air. The blown-off liquid is preferably collected in the liquid receiver 11 and discarded. Further, an air nozzle 5 is disposed on the opposite side of the elastic body 1, and it is preferable to prevent the back of the liquid film from being blown by blowing air. In addition, the air nozzle 5 can control the degree of pressure bonding of the long film to the elastic body by adjusting the air pressure, and the elastic body while adjusting the air pressure and pressurizing the back of the long film as will be described later. It is preferable to rub with. The air nozzle may be used as the means, or a back roll or the like may be used. However, it is preferable to use the air nozzle 5 from the viewpoint of preventing the back of the liquid film as described above. Next, the long film is transported to the dryer 7, both surfaces are dried, and transported to the functional layer coating step which is the next step.

  The guide rollers 2 and 2 ′ guide the running of the long film F. Here, each guide roller 2, 2 'is disposed at a predetermined position, but what is important at this time is that the long film F contacts the elastic body 1 with a wrap angle described later, and The same surface is guided so as to be close to the subsequent air nozzle 6.

  The elastic body 1 is disposed between the guide roller 2 and the guide roller 2 ′, and is rotated by being driven by a motor (not shown). The elastic body 1 is immersed in a liquid 4 having a lower portion disposed in the liquid tank 3. The long film F is continuously rubbed by the rotating elastic body 1 to correct wrinkles, strain and distortion on the surface.

  In addition, it is preferable that the lower part of the elastic body 1 is immersed in the liquid 4, and the surface is always wet with the liquid 4 by rotating. It is considered that this makes it possible to easily correct surface wrinkles, strain and distortion.

  In order to make the surface of the elastic body wet, it is also preferable to provide a liquid supply means to the elastic body surface, and examples of the liquid supply means include a liquid ejecting means.

  In another embodiment, as shown in FIG. 2, the elastic body surface may be wetted by directly injecting the liquid onto the elastic body 1, and as shown in the same figure, the lower part is a liquid storage tank for receiving the injected liquid. Can be provided. At this time, the lower portion of the elastic body can be cleaned by rubbing with a blade, a brush, a non-woven fabric, or the like in order to remove dirt and deposits on the elastic body surface. This method is preferable because dirt on the elastic body 1 and adhesion of foreign matters due to dirt in the liquid tank can be reduced.

  In the present invention, it is preferable that the surface to be treated of the long film is preliminarily coated with liquid before being continuously rubbed with a wet elastic body. The guide roller 2 shown in FIG. 1 can be wetted in advance before it is in contact with the liquid or is immersed in the liquid and the long film is rubbed with an elastic body. Or slip between film and roller. In the present invention, it is preferable that only the surface to be processed is wetted in advance, and the liquid supply means nozzle 8 of FIG. 1 is arranged between the guide roller 2 and the elastic body 1, and the liquid stored in the liquid tank 3 is piped. In order to prevent the occurrence of scratches due to foreign matter, it is preferable to preliminarily wet the surface to be processed of the long film by filtering through the filter 10 connected by the above and spraying from the nozzle 8 through the pressure pump 9. The nozzle 8 may be a single rod-shaped nozzle having a length in the width direction of the film, or a plurality of short nozzles may be used. Although the opening diameter of the nozzle is not particularly limited, it is preferably about 05 mm to 2 mm, and the amount of liquid fed is preferably in the range of 5 L / min to 50 L / min. FIG.5 (d) shows the installation position of the air nozzle 8, and you may install in any position of 8a-8e. Multiple units may be installed.

  The elastic body 1 may be rotated forward or backward with respect to the conveying direction of the long film F, but the absolute value of the difference in linear velocity between the elastic body 1 and the long film F is 5 m / min. It is preferable to set the diameter and the rotation speed so as to maintain the above. The rotation speed is preferably 1 to 100 rpm, more preferably 5 to 60 rpm.

  The conveyance speed of the long film F at the time of performing the treatment of the present invention is usually 5 to 200 m / min, preferably 10 to 100 m / min.

  It is suitable for continuous production that the elastic body 1 takes a roll shape. The elastic body 1 may be made of a single material such as natural rubber or synthetic rubber, or may be made of a composite material such as a metal roll and rubber. For example, metal rolls such as aluminum, iron, copper, and stainless steel, polyamides such as 6-nylon, 66-nylon, and copolymer nylon, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and copolyester, polyethylene, and polypropylene Polyolefins such as polyvinyl chloride, polyvinyl halides such as polyvinyl chloride, polyvinylidene fluoride, Teflon (registered trademark), natural rubber, neoprene rubber, nitrile rubber, nodel, viton rubber, hypalon, polyurethane, rayon (registered trademark), cellulose The surface of the metal roll can be coated with a thickness of 0.5 mm or more, preferably 0.5 to 100 mm, particularly preferably 1.0 to 50 mm. From the viewpoint of selecting the material of these elastic bodies, it is preferable that they are not softened or eluted by the liquid used. Further, the rubber hardness of the elastic body 1 is measured by a durometer A type according to the method defined in JISK-6253, and is preferably 15 to 70, more preferably 20 to 60.

  The present invention is characterized in that the static friction coefficient of the elastic body surface is 0.2 or more and 0.9 or less. More preferably, it is 0.3 or more and 0.8 or less. If it is less than 0.2, the effect of correcting the wrinkle, strain and distortion of the surface is weak, and if it exceeds 0.9, the rubbed long film is damaged.

  The static friction coefficient of the elastic body can be measured by the following method.

<Measurement of static friction coefficient of elastic body>
FIG. 3 shows an example of a method for measuring the static friction coefficient of the elastic body according to the present invention.

  Using a Haydon surface property tester TYPE: HEIDON-14D (manufactured by Shinto Kagaku Co., Ltd.), the friction coefficient of the object to be measured (vulcanized rubber molding) was measured by the ball indenter (SUSφ6) method. FIG. 3 shows the principle diagram of this test.

  In this Haydon surface property testing machine, as shown in FIG. 3, a weight for vertical load is mounted on a SUS ball via a support member, and the vertical load is applied on a test piece obtained by cutting the SUS ball from an elastic body. Press with a weight of 200 g. Then, the frictional force generated when the test piece is moved in the right direction toward the paper surface is measured.

  Other measurement conditions with the testing machine are described below.

Measuring jig; Ball indenter (SUSφ6)
Sample size: The sample size is not particularly limited, but a size that can secure a moving distance of 50 mm or more is preferable.

Test load: 200 g (weight for vertical load)
Test speed: 600 mm / min
Atmosphere: 23 ° C ± 2, 50% ± 10RH (no condensation within the air conditioning range)
The elastic body 1 according to the present invention is preferably a surface-modified rubber. In order to make the elastic body 1 have a static friction coefficient in the above range, fluorine treated with a sodium-naphthalene complex described in JP-A-7-158632. A method using a silicone rubber layer filled with a resin powder, a method using a thin film formed from a melt of ultrahigh molecular weight polyolefin powder described in JP-A-9-85900, and a method described in JP-A-11-166060. A method of forming a polycondensate of a hydrolyzate of alkoxysilane on a vulcanized rubber, a method of reacting a functional group-containing monomer described in JP-A No. 11-196991 with a rubber, and a rubber described in JP-A No. 2000-198864 and silica. A method of reacting, a method of heating and reacting a fluororubber substrate and a functional group-containing monomer described in JP-A No. 2002-371151, JP It is preferable to use a disclosed method such as a method using a chloroprene rubber described in 004-251373. However, in the present invention, a rubber is used for an elastic body as described in JP-A-2000-158842. A method of adjusting the surface by treating with an organic halogen compound is more preferable.

  Rubbers that can be modified by treatment with organic halogen compounds include acrylonitrile / butadiene rubber, chloroprene rubber, styrene / butadiene rubber, synthetic isoprene rubber, polybutadiene rubber, ethylene / propylene / diene terpolymer rubber, natural rubber, and the like. . A preferred elastic body for this purpose is acrylonitrile-butadiene rubber. These rubbers are usually used after being vulcanized, and vulcanization may be carried out by a usual vulcanization method used in the art.

  Examples of the organic halogen compounds used for modifying the rubbers include halogenated succinimides such as N-bromosuccinimide, isocyanuric acid halides such as trichloroisocyanuric acid and dichloroisocyanuric acid, and dichlorodimethylhydantoin. A halogenated hydantoin can be exemplified. Trichloroisocyanuric acid is preferred.

  In order for the organic halogen compound to act on the rubber surface, it is preferable to use it in an appropriate concentration by dissolving it in an organic solvent. Solvents suitable for this purpose must not react with this organic halogen compound. Examples of usable organic solvents include aromatic hydrocarbons such as benzene and xylene, diethyl ether, dioxane, tetrahydrofuran, and the like. Ethers, esters such as ethyl acetate, ketones such as methyl ethyl ketone and cyclohexanone, and chlorinated hydrocarbons such as ethyl chloride and chloroform. The concentration of the organic halogen compound in the organic solvent when the rubber surface is treated is not particularly limited, but is usually 2 to 10% by mass, preferably 4 to 6% by mass. When the concentration is higher than 2% by mass, the efficiency of modifying the rubber is good. On the other hand, when the concentration is lower than 10% by mass, uniform and effective application to the rubber surface is facilitated. There is nothing.

  In order for the solution of the organic halogen compound to act on the rubber, it is only necessary to bring them into contact with each other, and no special method is required. For example, it can be applied to the surface of the rubber with a spray or a brush, Rubber may be dipped and further rubbed.

  Further, the wrap angle of the long film F with respect to the elastic body 1 is determined by the arrangement of the guide rollers 2 and 2 ′ arranged before and after the elastic body 1. Increasing the wrap angle can extend the processing time for the passage of the long film F on the elastic body 1, so that a higher rubbing effect can be obtained, but it can be stably conveyed without causing wrinkles, rubbing scratches and meandering. Is set to less than 180 degrees, preferably 1 degree or more and less than 135 degrees, and more preferably 5 degrees or more and less than 90 degrees. Although the treatment time can be similarly extended by increasing the diameter of the elastic body 1, it is preferably less than 200 cm in diameter, preferably 5 cm or more and less than 100 cm, and more preferably 10 cm or more and less than 50 cm due to the problem of occupied space and cost.

The surface pressure applied to the long film F on the elastic body 1 can be controlled by the air pressure by the air nozzle 5 described above, but is further determined by the tension and roll diameter of the film transport system. Since the roll diameter is also related to the processing time, it is preferable to control the tension of the transport system. In order to obtain the effect of the present invention, it is preferable to keep the surface pressure high. However, if the surface pressure is set too high, the liquid film of the liquid is broken and the elastic body 1 and the long film F are in direct contact with each other, so that scratches are generated. It becomes easy. Usually preferably 9.8 × 10 ² Pa or less, more preferably 5 × 10 Pa or more 9.8 × 10 ² Pa or less, more preferably set to 4.9 × 10 ² Pa or less 5 × 10 Pa or higher.

  Moreover, it is preferable from the viewpoint of preventing the occurrence of watermarks, etc., to control the time during which the long film processing surface is wet with liquid by adjusting the distance of the air nozzle 6 from the elastic body. The time that the surface is wet is preferably 2 seconds or more and 60 seconds or less. In other words, it is preferable that the processing time from the start of wetting by the film wetting means to the end of the removal by the liquid removing means is from 2 seconds to 60 seconds. The starting point of the time when the surface to be processed of the long film is wet is when the liquid supply means (for example, the nozzle 8) that wets the long film surface in advance does not exist, is the start of processing by the elastic body 1, and the liquid supply means ( For example, when there is the nozzle 8), the time when the liquid is sprayed from the liquid supply means and the long film surface to be processed gets wet is the starting point. The end point of the wet time refers to a point in time when 95% or more of the droplets adhering to the treated surface of the long film are scattered or volatilized. The temperature of air sprayed from the air nozzle 6 is preferably room temperature to 80 ° C, more preferably 40 to 70 ° C.

  FIG. 6A to FIG. 6E are schematic views showing the installation location of the air nozzle 5 or 6 and the air blowing direction. FIG. 6A shows a state where air is blown by a counter in the film traveling direction, and FIGS. 6B and 6C show a state where air is blown toward the outside of the film. 6 (d) and 6 (e) are suitable for the air nozzles 5 and 6 installed mainly on the opposite side of the film to be processed, and are highly effective in preventing the back of the liquid.

  In the present invention, it is also preferable that a rinse nozzle 12 capable of injecting a liquid similar to the nozzle 8 is disposed at the position shown in FIGS.

  The rinse nozzle 12 is disposed in the vicinity of the guide roller 2 ′ and sprays liquid onto the surface of the long film F rubbed against the elastic body 1. Here, as the liquid ejected from the rinse nozzle 12, an unused liquid supplied from another liquid storage tank is used, or a liquid obtained by purifying the liquid 4 stored in the liquid tank 3 is preferably used. . 4 (a) and 4 (b), the liquid tank 3 and the rinse nozzle 12 are connected via a pipe, and the liquid 4 stored in the liquid tank 3 is pumped in the middle of the pipe. After being pulled out by the pump 9 and purified by the filtration filter 10, it is supplied to the rinse nozzle 12 and injected. The long film F is rinsed and cleaned on the surface rubbed against the elastic body 1 by the liquid ejected from the rinse nozzle 12, thereby washing away foreign matters and the like that are accompanied by the liquid and reattached to the elastic body 1. The liquid sprayed from the rinse nozzle 12 hits the film surface or the surface of the elastic body 1, falls by its own weight, and is collected in the liquid tank 3. FIG. 4C shows an example in which after the liquid 4 is jetted onto the film surface by the rinse nozzle 12, the film is held by the guide roller 2 ″ and air is jetted by the air nozzle 6 at that location.

  Moreover, although the filtration filter used here can be selected suitably, the filter of the hole diameter of 0.1-10 micrometers is used individually or in combination suitably. In addition, a pleated fold type cartridge filter can be advantageously selected from the viewpoint of filtration life and ease of handling.

  The filtration circulation flow rate must be set so that the number of foreign matters in the liquid tank does not increase with time due to foreign matters brought in from the film surface. The HIAC / ROYCO liquid particulate counter model 4100 manufactured by Nozaki Sangyo Co., Ltd. is used for the quantification of the number of foreign matters floating in the liquid, and the filter fraction size is set so that the size of particles to be removed does not increase with the operating time. And the circulation flow rate can be adjusted.

  Further, the liquid 4 is not particularly limited, but a liquid that does not dissolve / extract components contained in the long film F or an undercoat layer incorporated in the base surface by coating or other methods is selected. Preferably, water or pure water containing an organic solvent such as methanol, ethanol, isopropyl alcohol, acetone, methyl acetate, toluene, xylene, or a fluorinated solvent, acid, alkali, salt, surfactant, antifoaming agent, etc. The most preferred is pure water.

  In the present invention, the temperature of the liquid 4 is usually from 0 to 100 ° C., but preferably from 30 ° C. to 100 ° C., and at the same time, the temperature of the elastic body is also from 30 ° C. to 100 ° C., It is preferable for obtaining the effects of the present invention. The temperature of the liquid 4 is preferably adjusted by hot water circulation using a normal heater method, and the temperature of the elastic body can be adjusted by immersing it in hot water for an appropriate time or by circulating hot water inside the elastic body. preferable.

  FIG. 5 is a diagram showing a method of cleaning the elastic body 1 according to the present invention.

  5A shows a method using an ultrasonic vibrator, FIG. 5B shows a method using a blade, and FIG. 5C shows a method of rubbing with another elastic body such as a rubber roller. FIG. 5D shows the installation position of the air nozzle 8, and it may be installed at any position of 8a to 8e.

  In FIG. 5A, reference numeral 13 denotes an ultrasonic transducer. The ultrasonic vibrator 13 emits ultrasonic waves to the surface of the elastic body 1 to drop the transferred foreign matter. The ultrasonic transducer 13 is disposed so that the liquid 4 is held between the elastic body 1 and the elastic body 1 in order to efficiently propagate the emitted ultrasonic waves to the surface of the elastic body 1. A plurality of vibrators may be provided. In this case, it is necessary to determine the interval between the ultrasonic vibrators so that the ultrasonic waves from adjacent vibrators are uniformly overlapped.

  The frequency of the ultrasonic transducer 13 can be 10 to 100,000 kHz. It is also possible to combine a plurality of vibrators that oscillate at different frequencies or use a vibrator capable of frequency modulation.

Ultrasonic output per transducer unit area can be used ^{0.1W / cm 2 ~2W / cm 2} . The distance from the ultrasonic transducer 13 to the long film F has an optimum point due to the presence of a standing wave, and is desirably a distance that is an integral multiple of the following equation.

λ = C / f
Here, λ is the wavelength, C is the ultrasonic wave propagation velocity in the liquid, and f is the frequency.

  The ultrasonic treatment time is preferably 1-100 sec and 10-100,000 kHz. Most preferably, it is 40-1500kHz.

  As ultrasonic transducers used, WS-600-28N, WS-600-40N, WS600-75N, WS-600-100N, WS-1200-28N, WS-1200-40N, WS- manufactured by Honda Electronics Co., Ltd. 1200-75N, WS-1200-100N, N60R-M, N30R-M, N60R-M, W-100-HFMKIIN, W-200-HFMKIIN, and those manufactured by Nippon Alex Co., Ltd. are used.

  The blade 14 in FIG. 5B uses a material that does not damage the surface of the elastic body, such as rubber, sponge, or brush, and scrapes off foreign matter or the like attached to the surface of the elastic body.

  FIG. 5 (c) shows that the adhered foreign matter is removed by continuously rubbing the surface of the elastic body with a roller 15 such as rubber, sponge, brush, nonwoven fabric or the like using a material whose hardness is lower than that of the elastic body 1. I can do it.

  In the present invention, it is preferable to add a device for preventing meandering of a long film in order to correct wrinkles, strains, distortions, etc. more accurately, and an edge position controller (EPC and EPC) described in JP-A-6-8663. And a meandering correction device such as a center position controller (also referred to as CPC) is preferably used. These devices detect the edge of the film with an air servo sensor or optical sensor, control the transport direction based on that information, and try to keep the edge of the film and the center in the width direction at a fixed location. As an actuator, specifically, one or two guide rolls and a flat expander roll with drive are moved to the left and right (or up and down) with respect to the line direction, and the meandering is corrected. Are installed on the front and back of the film (one on each side of the film, and on both sides of the film). Cross guider method). The principle of the meandering correction of these devices is that when the film is moving, for example, when going to the left, in the former method, the roll is tilted so that the film goes to the right, and in the latter method, one set on the right side is used. This pinch roll is nipped and pulled to the right.

  It is preferable to install these meandering prevention devices within the range of 2 to 30 m upstream or downstream from the position where the elastic body according to the present invention is disposed, and at least one of each is installed upstream and downstream. It is more preferable.

  The optical film according to the present invention is obtained through the above-described production method, and in the present invention, the optical film is preferably an antireflection film.

  A feature of the antireflection film in the present invention is a laminate of an optical interference layer in which a high refractive layer and a low refractive layer are laminated in order from the support side on at least one surface of the support (in some cases, other layers may be added). May be added.) A hard coat layer is preferably provided between the support and the antireflection layer. The hard coat layer is provided using an actinic radiation curable resin described later.

  In the antireflection layer, the optical film thickness of the high refractive layer and the low refractive layer is preferably set to λ / 4 with respect to light of wavelength λ. The optical film thickness is an amount defined by the product of the refraction n and the film thickness d of the layer. The refractive index level is largely determined by the metal or compound contained therein, for example, Ti is high, Si is low, F-containing compounds are even lower, and the refractive index is set by such a combination. The refractive index and the film thickness are calculated and calculated by measuring the spectral reflectance.

  Here, when a film is obtained by applying a solution containing a metal compound to a support, this antireflection optical characteristic is determined only by the physical film thickness as described above.

  In particular, the color of reflected light near 550 nm changes between red purple and blue purple when the film thickness is shifted by only a few nm. This color unevenness is hardly noticeable when the amount of transmitted light from the display is large, but the color unevenness is conspicuous when the light amount is small or the display is turned off, and the visibility is poor. Further, when the film thickness deviation is large, the reflectance at 400 to 700 nm cannot be lowered, and it becomes difficult to obtain desired antireflection characteristics.

[Long film]
Although it does not specifically limit as a elongate film used in this invention, For example, a polyester film, a cellulose-ester film, a polycarbonate film, a polyether sulfone film, a cyclic olefin resin film etc. can be mentioned. Those formed by melt casting or solvent casting are preferably used. Among them, a cellulose ester film is preferable in the present invention, and a cellulose ester film stretched in at least one direction is particularly preferable. As the cellulose ester film, for example, Konica Minoltack KC8UX, KC4UX, KC5UX, KC8UY, KC4UY, KC12UR, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC8UE, KC4UE, KC4FR (Opposite Konica Norta) Etc. are preferably used. The film thickness of the long film is 10 to 500 μm, preferably 10 to 200 μm, and the length is 100 to 10,000 m, preferably 300 to 5000 m. The width is preferably 1 to 4 m.

  The cellulose used as a raw material for the cellulose ester preferably used in the present invention is not particularly limited, and examples thereof include cotton linter, wood pulp, and kenaf. Moreover, although the cellulose ester obtained from them can be used individually or in mixture in arbitrary ratios, it is preferable to use 50 mass% or more of cotton linters.

Cellulose esters use an organic acid such as acetic acid or an organic solvent such as methylene chloride when the acylating agent of the cellulose raw material is an acid anhydride (acetic anhydride, propionic anhydride, or butyric anhydride). The reaction is carried out using a novel protic catalyst. When the acylating agent is acid chloride (CH ₃ COCl, C ₂ H ₅ COCl, C ₃ H ₇ COCl), the reaction is carried out using a basic compound such as an amine as a catalyst. Specifically, it can be synthesized by the method described in JP-A-10-45804. In the cellulose ester, the acyl group reacts with the hydroxyl group of the cellulose molecule. Cellulose molecules are composed of many glucose units linked together, and the glucose unit has three hydroxyl groups. The number of acyl groups derived from these three hydroxyl groups is called the degree of substitution.

  For example, cellulose triacetate has an acetyl group bonded to all three hydroxyl groups of the glucose unit.

  Although there is no limitation in particular in the cellulose ester which can be used for a cellulose-ester film, it is preferable that the substitution degree of a total acyl group is 2.40-2.98, and the substitution degree of an acetyl group is 1. 4 or more is more preferably used.

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

  Cellulose ester has a propionate group or butyrate group in addition to acetyl groups such as cellulose acetate such as cellulose triacetate and cellulose diacetate, cellulose acetate propionate, cellulose acetate butyrate, or cellulose acetate propionate butyrate. A cellulose ester is preferred. Note that butyrate includes iso- in addition to n-. Cellulose acetate propionate having a large substitution degree of propionate group is excellent in water resistance.

  The number average molecular weight Mn of the cellulose ester (measurement method is described below) is preferably in the range of 70,000 to 250,000 because the resulting film has high mechanical strength and an appropriate dope viscosity. Furthermore, 80000-150,000 are preferable. In addition, a cellulose ester having a mass average molecular weight Mw (Mw / Mn) of 1.0 to 5.0 is preferably used, and more preferably 1.5 to 4.5.

<Measurement of number average molecular weight of cellulose ester>
Measured by high performance liquid chromatography under the following conditions.

Solvent: Acetone Column: MPW × 1 (manufactured by Tosoh Corporation)
Sample concentration: 0.2 (mass / volume)%
Flow rate: 1.0 ml / min Sample injection amount: 300 μL
Standard sample: polymethyl methacrylate (mass average molecular weight 188,200)
Temperature: 23 ° C
In addition, it is preferable that the amount of metal in the cellulose ester used in the production of the cellulose ester or mixed in a small amount in the material used is as small as possible, and the total content of metals such as Ca, Mg, Fe, Na is 100 ppm. The following is preferred.

[Organic solvent]
As an organic solvent used for cellulose ester solution or dope formation useful for dissolving cellulose ester, chlorinated organic solvent methylene chloride (methylene chloride) can be exemplified, and is suitable for dissolving cellulose ester, particularly cellulose triacetate. Examples of the non-chlorine organic solvent include methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1, Examples include 1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol, nitroethane, and the like.

  When these organic solvents are used for cellulose triacetate, a dissolution method at room temperature can be used, but an insoluble material can be obtained by using a dissolution method such as a high-temperature dissolution method, a cooling dissolution method, or a high-pressure dissolution method. Can be reduced, which is preferable.

  Although methylene chloride can be used for cellulose esters other than cellulose triacetate, methyl acetate, ethyl acetate, and acetone can be preferably used without using methylene chloride. Particularly preferred is methyl acetate. In the present invention, an organic solvent having good solubility with respect to the cellulose ester is referred to as a good solvent, and has a main effect on dissolution, and an organic solvent used in a large amount among them is a main (organic) solvent or a main ( Organic) solvent.

  The dope preferably contains 1 to 40% by mass of an alcohol having 1 to 4 carbon atoms in addition to the organic solvent. These are used as a gelling solvent that casts the dope on a metal support and then the solvent begins to evaporate and the ratio of alcohol increases and the web gels, making the web strong and easy to peel off from the metal support. When these ratios are small, there is also a role of promoting the dissolution of the cellulose ester of the non-chlorine organic solvent.

  Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol.

  Of these, ethanol is preferred because it has excellent dope stability, has a relatively low boiling point, good drying properties, and no toxicity. These organic solvents are called poor solvents because they are not soluble in cellulose esters by themselves.

[Production of cellulose ester film by solution casting method]
A method for forming a cellulose ester film used as a support will be described. The cellulose ester film is produced by a solution casting film forming method.

  (1) Dissolution step: a step of dissolving the cellulose ester, polymer and additives in an organic solvent mainly containing a good solvent for cellulose ester (flaked) while stirring to form a dope, or cellulose ester In this step, a polymer solution or an additive solution is mixed with the solution to form a dope. For dissolving the cellulose ester, a method carried out at normal pressure, a method carried out below the boiling point of the main solvent, a method carried out under pressure above the boiling point of the main solvent, JP-A-9-95544, 9-95557 or 9- Various dissolution methods such as a method performed by a cooling dissolution method as described in JP-A-95538 and a method performed at high pressure as described in JP-A No. 11-21379 can be used. A method in which pressure is applied at a boiling point or higher is preferred.

  The concentration of the cellulose ester in the dope is preferably 10 to 35% by mass. An additive is added to the dope during or after dissolution to dissolve and disperse, then filtered through a filter medium, defoamed, and sent to the next step with a liquid feed pump.

  (2) Casting step: An endless metal belt, such as a stainless steel belt or a rotating metal drum, which feeds the dope through a liquid feed pump (for example, a pressurized metering gear pump) to a pressure die and transfers it indefinitely. This is a step of casting the dope from the pressure die slit to the casting position on the support. A pressure die that can adjust the slit shape of the die base portion and can easily make the film thickness uniform is preferable. Examples of the pressure die include a coat hanger die and a T die, and any of them is preferably used. The surface of the metal support is a mirror surface. In order to increase the film forming speed, two or more pressure dies may be provided on the metal support, and the dope amount may be divided and stacked.

  (3) Solvent evaporation step: heating the web (referred to as the dope film after casting the dope on the metal support as the web) on the metal support until the web becomes peelable from the metal support This is a step of evaporating the solvent. In order to evaporate the solvent, there are a method of blowing air from the web side and / or a method of transferring heat from the back side of the metal support by a liquid, a method of transferring heat from the front and back by radiant heat, and the like. However, the drying efficiency is preferable. A method of combining them is also preferable. In the case of backside liquid heat transfer, it is preferable to heat at or below the boiling point of the main solvent of the organic solvent used in the dope or the organic solvent having the lowest boiling point.

  (4) Peeling step: This is a step of peeling the web where the solvent has evaporated on the metal support at the peeling position. The peeled web is sent to the next process. If the residual solvent amount of the web at the time of peeling is too large, peeling is difficult, or conversely, if it is peeled off after sufficiently drying on the metal support, a part of the web is peeled off.

  There is a gel casting method (gel casting) as a method for increasing the film forming speed (the film forming speed can be increased because the film is peeled off while the residual solvent amount is as large as possible).

  In the method for drying and manufacturing the optical film according to the present invention, when the cellulose ester film manufactured by the solution casting film forming method is used as the support, the solution casting film forming method itself is not particularly limited. A method commonly used in the art, for example, U.S. Pat. Nos. 2,492,978, 2,739,070, 2,739,069, 2,492,977, No. 2,336,310, No. 2,367,603, No. 2,607,704, British Patent Nos. 64,071, No. 735,892, No. 45-9074 49-4554, 49-5614, 60-27562, 61-39890, 62-4208 and the like can be referred to.

  The solvent used for the preparation of the cellulose ester dope solution used in the solution casting film forming method may be used alone or in combination of two or more. However, a good solvent and a poor solvent of cellulose ester are mixed and used. It is preferable from the viewpoint of production efficiency, and further, a better amount of a good solvent is preferable from the viewpoint of solubility of the cellulose ester. The preferable range of the mixing ratio of the good solvent and the poor solvent is 70 to 98% by mass for the good solvent and 2 to 30% by mass for the poor solvent.

  With a good solvent and a poor solvent, what melt | dissolves the cellulose ester to be used independently is defined as a good solvent, and a solvent that swells or does not dissolve alone is defined as a poor solvent. Therefore, depending on the average degree of acetylation of cellulose ester, the object of good solvent and poor solvent changes. For example, when acetone is used as a solvent, the amount of bound acetic acid 55% of cellulose ester becomes a good solvent, and the amount of bound acetic acid 60 % Is a poor solvent.

  The good solvent used in the present invention is not particularly limited. For example, in the case of cellulose triacetate, organic halogen compounds such as methylene chloride, dioxolanes, methyl acetate, and in the case of cellulose acetate propionate, methylene chloride. , Acetone, methyl acetate and the like.

  Moreover, it is although it does not specifically limit as a poor solvent used for this invention, For example, methanol, ethanol, i-propyl alcohol, n-butanol, cyclohexane, acetone, cyclohexanone etc. are used preferably.

  As a method for dissolving the cellulose ester when preparing the dope solution, a general method can be used, but under pressure, at a temperature not lower than the boiling point at the normal pressure of the solvent and not causing the solvent to boil. A method of heating and stirring while stirring is more preferable because it can prevent the generation of massive undissolved material called gel or mamako.

  Further, a method in which the cellulose ester is mixed with a poor solvent and wetted or swollen and then mixed with a good solvent and dissolved is also preferably used.

  The type of the pressure vessel is not particularly limited, and it is sufficient that it can withstand a predetermined pressure and can be heated and stirred under pressure. In addition to the pressure vessel, other instruments such as a pressure gauge and a thermometer are appropriately disposed. The pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or by increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy.

  The heating temperature with the addition of the solvent is preferably a temperature in the range where the solvent used is at or above the normal pressure and the solvent does not boil from the viewpoint of the solubility of the cellulose ester, but is necessary if the heating temperature is too high. Increased pressure increases productivity. A preferable heating temperature is 45 to 120 ° C, more preferably 60 to 110 ° C, and still more preferably 70 to 105 ° C. The pressure is adjusted at a set temperature so that the solvent does not boil.

  In addition to cellulose ester and solvent, the necessary plasticizer, UV absorber and other additives can be mixed with the solvent in advance, dissolved or dispersed, and then added to the solvent before dissolving the cellulose ester. You may throw into dope.

  After dissolution, take it out from the container while cooling, or take it out from the container with a pump and cool it with a heat exchanger, etc., and use it for film formation, but the cooling temperature at this time may be cooled to room temperature It is more preferable to cool to a temperature 5 to 10 ° C. lower than the boiling point and perform casting at that temperature because the dope viscosity can be reduced.

  The measuring method of the substitution degree of an acyl group can be measured according to the provisions of ASTM-817-96.

  These cellulose esters are produced (film formation) by a method generally referred to as a solution casting film forming method as described later. This method is a metal support for casting (hereinafter simply referred to as a metal support) such as an endless metal belt (for example, a stainless steel belt) that moves indefinitely or a rotating metal drum (for example, a drum whose surface is chrome-plated with cast iron). The dope (cellulose ester solution) is cast (casting) from a pressure die, and the web (dope film) on the metal support is peeled off from the metal support and dried. It is.

  The cellulose ester film preferably contains an ultraviolet absorber described below from the viewpoint of preventing deterioration when placed outdoors as an image display device.

  As the ultraviolet absorber, those having an excellent ability to absorb ultraviolet rays having a wavelength of 370 nm or less and little absorption of visible light having a wavelength of 400 nm or more can be preferably used. Examples include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like, but the present invention is not limited thereto.

  In the present invention, the film thickness of the cellulose ester film used as the long film is preferably 10 to 200 μm, particularly preferably 30 to 70 μm. Conventionally, in such a thin film, coating unevenness was likely to occur, but stable coating properties can be expected even with a thin film of 70 μm or less according to the present invention.

  In the present invention, when the optical thin film is provided on the support surface as described above, the film thickness deviation with respect to the average film thickness can be provided to be ± 8%, and more preferably within ± 5%. In particular, a uniform thin film within ± 1% can be obtained. The production method of the present invention exhibits a remarkable effect particularly when applied to a wide optical film of 1400 mm or more. The upper limit of the optical film width that is preferably applied is not particularly limited from the viewpoint of film thickness accuracy, but is preferably 4000 mm or less from the viewpoint of manufacturing cost.

  The optical film which concerns on this invention can make it easy to convey and wind up by containing a mat agent in a cellulose-ester film.

  The matting agent is preferably as fine as possible. Examples of the fine particles include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, and silica. Inorganic fine particles such as magnesium oxide and calcium phosphate, polymethacrylic acid methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, Melamine-based resin powder, polyolefin-based resin powder, polyester-based resin powder, polyamide-based resin powder, polyimide-based resin powder, polyfluorinated ethylene-based resin powder, etc. Molecular fine particles are preferred. The present invention is not limited to these.

  Among these, silicon dioxide is particularly preferable for adjusting the dynamic friction coefficient, and is preferable because the haze of the film can be reduced. The average particle diameter of the primary particles or secondary particles of the fine particles is in the range of 0.01 to 5.0 μm, and the content is preferably 0.005 to 0.5 mass% with respect to the cellulose ester.

  In many cases, fine particles such as silicon dioxide are surface-treated with an organic material, but such particles are preferable because they can reduce the haze of the film.

  Preferred organic substances for the surface treatment include halosilanes, alkoxysilanes, silazanes, siloxanes and the like. The larger the average particle size of the fine particles, the greater the sliding effect. On the other hand, the smaller the average particle size, the better the transparency. Therefore, the average particle size of the preferred primary particles is preferably 20 nm or less, preferably 5 to 5 nm. 16 nm, particularly preferably 5 to 12 nm.

  In the cellulose ester film, these fine particles preferably form irregularities of 0.01 to 1.0 μm on the surface of the cellulose ester film.

  Examples of the fine particles of silicon dioxide include Aerosil 200, 200V, 300, R972, R972V, R974, R202, R812, OX50, TT600, etc. manufactured by Nippon Aerosil Co., preferably Aerosil 200V, R972, R972V, R974, R202, and R812. Two or more kinds of these fine particles may be used in combination. When using 2 or more types together, it can mix and use in arbitrary ratios. In this case, fine particles having different average particle sizes and materials, for example, Aerosil 200V and R972V can be used in a mass ratio of 0.1: 99.9 to 99.9 to 0.1. Commercially available products such as Aerosil R976 or R811 (manufactured by Nippon Aerosil Co., Ltd.) can be used as zirconium oxide.

  As the organic fine particles, for example, commercially available products such as Tospearl 103, 105, 108, 120, 145, 3120, 240 (manufactured by Toshiba Silicone Co., Ltd.) can be used as the silicone resin.

  The primary average particle diameter of the fine particles preferably used in the present invention is measured by observing particles with a transmission electron microscope (magnification 500,000 to 2,000,000 times), observing 100 particles, and using the average value, 1 The next average particle diameter was used.

  The apparent specific gravity of the fine particles is preferably 70 g / liter or more, more preferably 90 to 200 g / liter, and particularly preferably 100 to 200 g / liter. A larger apparent specific gravity makes it possible to make a high-concentration dispersion, which improves haze and agglomerates, and is preferable when preparing a dope having a high solid content concentration as in the present invention. Are particularly preferably used.

  Silicon dioxide fine particles having an average primary particle diameter of 20 nm or less and an apparent specific gravity of 70 g / L or more are, for example, a mixture of vaporized silicon tetrachloride and hydrogen burned in air at 1000 to 1200 ° C. Can be obtained. In the present invention, the apparent specific gravity described above was calculated by the following equation by measuring a weight of silicon dioxide fine particles in a graduated cylinder and measuring the weight at that time.

Apparent specific gravity (g / L) = silicon dioxide mass (g) / volume of silicon dioxide (L)
As a method for preparing a fine particle dispersion useful for the present invention and a method for adding it to a dope, for example, the following three methods can be mentioned.

<< Preparation Method A >>
After stirring and mixing the organic solvent and the fine particles, dispersion is performed with a disperser. This is a fine particle dispersion. The fine particle dispersion is added to the dope solution and stirred.

<< Preparation Method B >>
After stirring and mixing the organic solvent and the fine particles, dispersion is performed with a disperser. This is a fine particle dispersion. Separately, a fine particle dispersion is added to a solution obtained by adding a small amount of cellulose ester to an organic solvent and stirring and dissolving, and stirring. This is used as a fine particle addition solution and sufficiently mixed with the dope solution using an in-line mixer. Here, an ultraviolet absorber may be added after the addition of the following fine particle additive solution.

<< Preparation Method C >>
Add a small amount of cellulose ester to the organic solvent and dissolve with stirring. Fine particles are added to this and dispersed by a disperser. This is a fine particle addition solution. The fine particle additive solution is sufficiently mixed with the dope solution using an in-line mixer.

  Preparation method A is excellent in dispersibility of silicon dioxide fine particles, and preparation method C is excellent in that silicon dioxide fine particles are difficult to re-aggregate. Among them, the preparation method B described above is a preferable preparation method that is excellent in both dispersibility of the silicon dioxide fine particles and that the silicon dioxide fine particles are less likely to reaggregate.

《Distribution method》
The concentration of silicon dioxide when the silicon dioxide fine particles are mixed and dispersed with an organic solvent or the like is preferably 5 to 30% by mass, more preferably 10 to 25% by mass, and most preferably 15 to 20% by mass.

  The amount of silicon dioxide fine particles added to cellulose ester is preferably 0.01 to 0.5 parts by mass, more preferably 0.05 to 0.2 parts by mass, and more preferably 0.0 to 0.2 parts by mass with respect to 100 parts by mass of cellulose ester. Most preferred is 08 to 0.12 parts by mass. The larger the added amount, the better the dynamic friction coefficient of the cellulose ester film, and the smaller the added amount, the lower the haze and the fewer the aggregates.

  The organic solvent used in the dispersion is preferably a lower alcohol, and examples of the lower alcohol include methanol, ethanol, propyl alcohol, isopropyl alcohol, butanol, and the like. Although it does not specifically limit as organic solvents other than a lower alcohol, The organic solvent used at the time of dope preparation is preferable.

  As the disperser, a normal disperser can be used. Dispersers can be broadly divided into media dispersers and medialess dispersers. The latter is preferable for dispersing silicon dioxide fine particles because the haze is lowered. Examples of the media disperser include a ball mill, a sand mill, and a dyno mill. The medialess disperser includes an ultrasonic type, a centrifugal type, and a high pressure type. In the present invention, a high pressure type is preferable, and a high pressure dispersion device is preferable. The high-pressure dispersion device is a device that creates special conditions such as high shear and high pressure by passing a composition in which fine particles and an organic solvent are mixed at high speed through a narrow tube. When processing with a high-pressure dispersion apparatus, for example, the maximum pressure condition inside the apparatus is preferably 9.8 MPa or more in a thin tube having a tube diameter of 1 to 2000 μm. More preferably, it is 19.6 MPa or more. Further, at that time, those having a maximum reaching speed of 100 m / second or more and those having a heat transfer speed of 420 kJ / hour or more are preferable.

  The high-pressure dispersing apparatus as described above includes an ultra-high pressure homogenizer (trade name: Microfluidizer) manufactured by Microfluidics Corporation or a nanomizer manufactured by Nanomizer, and other manton gorin type high-pressure dispersing apparatuses such as homogenizer manufactured by Izumi Food Machinery, Ltd. There is UHN-01 manufactured by Wakki Co., Ltd.

  In the present invention, when the fine particles are contained, it is preferably uniformly distributed in the thickness direction of the cellulose ester film, but is more preferably distributed so as to exist mainly in the vicinity of the surface. Preferably, two or more kinds of dopes are cast simultaneously from the die by a co-casting method, and the dope containing fine particles is arranged on the surface layer side. By doing so, the haze can be reduced and the dynamic friction coefficient can be lowered. More preferably, it is desirable to use a dope arrangement in which fine particles are contained in one or both layers on the surface layer side using three kinds of dopes.

  In order to adjust the dynamic friction coefficient of the support, a back coat layer containing fine particles can be provided on the back side. The dynamic friction coefficient can be adjusted by the size, amount, material, etc. of the fine particles to be added.

  As the plasticizer preferably used in the present invention, a phosphate ester plasticizer and a non-phosphate ester plasticizer are preferably used.

  Examples of the phosphate ester plasticizer include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate and the like.

  Non-phosphate ester plasticizers include phthalate esters, polyhydric alcohol esters, polycarboxylic acid esters, citric acid esters, glycolic acid esters, fatty acid esters, pyromellitic acid esters, trimellitic acid esters, polyesters, etc. can give.

  Of these, polyhydric alcohol ester plasticizers, phthalate esters, citrate esters, fatty acid esters, glycolate plasticizers, polyester plasticizers, and the like are preferable.

  The polyhydric alcohol ester plasticizer is a plasticizer comprising an ester of a dihydric or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. Preferably it is a 2-20 valent aliphatic polyhydric alcohol ester.

  The polyhydric alcohol used in the present invention is represented by the following general formula (1).

Formula (1) R1- (OH) n
However, R1 represents an n-valent organic group, n represents a positive integer of 2 or more, and the OH group represents an alcoholic and / or phenolic hydroxyl group.

  Examples of preferred polyhydric alcohols include the following, but the present invention is not limited to these. Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane- Examples include 1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, and xylitol. In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable.

  There is no restriction | limiting in particular as monocarboxylic acid used for the polyhydric alcohol ester of this invention, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention.

  Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto.

  As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. The number of carbon atoms is more preferably 1-20, and particularly preferably 1-10. When acetic acid is contained, the compatibility with the cellulose ester is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.

  Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanoic acid, undecylic acid, lauric acid, tridecylic acid, Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, and laccelic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid.

  Examples of preferable alicyclic monocarboxylic acids include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof.

  Examples of preferred aromatic monocarboxylic acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and two or more benzene rings such as biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetralincarboxylic acid. The aromatic monocarboxylic acid which has, or those derivatives can be mentioned. Benzoic acid is particularly preferable.

  The molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably 300 to 1500, and more preferably 350 to 750. A higher molecular weight is preferred because it is less likely to volatilize, and a smaller one is preferred in terms of moisture permeability and compatibility with cellulose ester.

  The carboxylic acid used for the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.

  Below, the specific compound of a polyhydric alcohol ester is illustrated.

  The glycolate plasticizer is not particularly limited, but alkylphthalylalkyl glycolates can be preferably used. Examples of alkyl phthalyl alkyl glycolates include methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, methyl phthalyl ethyl Glycolate, ethyl phthalyl methyl glycolate, ethyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl phthalyl ethyl glycolate, propyl phthalyl butyl glycol Butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate, octyl phthalyl methyl glycolate, octyl phthalate Ethyl glycolate, and the like.

  Examples of the phthalate ester plasticizer include diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, and dicyclohexyl terephthalate.

  Examples of the citrate plasticizer include acetyl trimethyl citrate, acetyl triethyl citrate, and acetyl tributyl citrate.

  Examples of fatty acid ester plasticizers include butyl oleate, methylacetyl ricinoleate, and dibutyl sebacate.

  The polyester plasticizer is not particularly limited, but a polyester plasticizer having an aromatic ring or a cycloalkyl ring in the molecule can be preferably used. Although it does not specifically limit as a preferable polyester plasticizer, For example, the aromatic terminal ester plasticizer represented by following General formula (2) is preferable.

General formula (2) B- (GA) n-GB
(In the formula, B is a benzene monocarboxylic acid residue, G is an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms, A represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more.)
In the general formula (2), a benzene monocarboxylic acid residue represented by B and an alkylene glycol residue, oxyalkylene glycol residue or aryl glycol residue represented by G, an alkylene dicarboxylic acid residue or aryl dicarboxylic group represented by A It is composed of an acid residue and can be obtained by a reaction similar to that of a normal polyester plasticizer.

  Examples of the benzene monocarboxylic acid component of the polyester plasticizer used in the present invention include benzoic acid, para-tert-butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid, and normalpropyl. There exist benzoic acid, aminobenzoic acid, acetoxybenzoic acid, etc., and these can be used as 1 type, or 2 or more types of mixtures, respectively.

  Examples of the alkylene glycol component having 2 to 12 carbon atoms of the polyester plasticizer include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1, 2-propanediol, 2-methyl 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2,2 -Diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3propanediol (3,3-dimethylolheptane), 3-methyl-1, 5-pentanediol 1,6-hexanediol, 2,2,4-trimethyl 1,3-pentanediol, 2-ethyl 1, -Hexanediol, 2-methyl 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, etc., and these glycols are one kind or two kinds or more Used as a mixture. In particular, an alkylene glycol having 2 to 12 carbon atoms is particularly preferable because of excellent compatibility with a cellulose ester.

  Examples of the oxyalkylene glycol component having 4 to 12 carbon atoms of the aromatic terminal ester include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. Or it can be used as a mixture of two or more.

  Examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms of the aromatic terminal ester include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. These are used as one kind or a mixture of two or more kinds. Examples of the arylene dicarboxylic acid component having 6 to 12 carbon atoms include phthalic acid, terephthalic acid, isophthalic acid, 1,5 naphthalene dicarboxylic acid, and 1,4 naphthalene dicarboxylic acid.

  The polyester plasticizer that can be used in the present invention has a number average molecular weight of preferably 300 to 1500, more preferably 400 to 1000. The acid value is preferably 0.5 mgKOH / g or less, the hydroxyl value is 25 mgKOH / g or less, more preferably the acid value is 0.3 mgKOH / g or less, and the hydroxyl value is 15 mgKOH / g or less. Hereinafter, synthesis examples of the aromatic terminal ester plasticizer will be shown.

<Sample No. 1 (Aromatic terminal ester sample)>
A reaction vessel was charged with 410 parts of phthalic acid, 610 parts of benzoic acid, 737 parts of dipropylene glycol, and 0.40 part of tetraisopropyl titanate as a catalyst. While refluxing the monohydric alcohol, heating was continued at 130 to 250 ° C. until the acid value became 2 or less, and water produced was continuously removed. Subsequently, the distillate was removed at 200 to 230 ° C. under a reduced pressure of 100 to finally 4 × 10 ² Pa or less, and then filtered to obtain an aromatic terminal ester plasticizer having the following properties.

Viscosity (25 ° C., mPa · s); 43400
Acid value: 0.2
<Sample No. 2 (Aromatic terminal ester sample)>
Sample No. 1 was used except that 410 parts of phthalic acid, 610 parts of benzoic acid, 341 parts of ethylene glycol, and 0.35 part of tetraisopropyl titanate as a catalyst were used in the reaction vessel. In the same manner as in No. 1, an aromatic terminal ester having the following properties was obtained.

Viscosity (25 ° C., mPa · s); 31000
Acid value: 0.1
<Sample No. 3 (Aromatic terminal ester sample)>
Sample No. 1 was used except that 410 parts of phthalic acid, 610 parts of benzoic acid, 418 parts of 1,2-propanediol, and 0.35 part of tetraisopropyl titanate as the catalyst were used in the reaction vessel. In the same manner as in No. 1, an aromatic terminal ester having the following properties was obtained.

Viscosity (25 ° C., mPa · s); 38000
Acid value: 0.05
<Sample No. 4 (Aromatic terminal ester sample)>
Sample No. 4 was used except that 410 parts of phthalic acid, 610 parts of benzoic acid, 418 parts of 1,3-propanediol, and 0.35 part of tetraisopropyl titanate as a catalyst were used in the reaction vessel. In the same manner as in No. 1, an aromatic terminal ester having the following properties was obtained.

Viscosity (25 ° C., mPa · s); 37000
Acid value: 0.05
Although the specific compound of an aromatic terminal ester plasticizer is shown below, this invention is not limited to this.

  These plasticizers can be used alone or in combination of two or more. If the amount of the plasticizer used is less than 1% by mass relative to the cellulose ester, the effect of reducing the moisture permeability of the film is small, which is not preferable. If the amount exceeds 20% by mass, the plasticizer bleeds out from the film, and the physical properties of the film Since it deteriorates, 1-20 mass% is preferable. 6-16 mass% is still more preferable, Especially preferably, it is 8-13 mass%.

  The ultraviolet absorber preferably used in the present invention will be described.

  Specific examples of the ultraviolet absorber include, for example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. Instead, other ultraviolet absorbers are also used.

  Specific examples include the following compounds.

UV-1: 2- (2'-hydroxy-5'-methylphenyl) benzotriazole UV-2: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole UV-3 : 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole UV-4: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl)- 5-Chlorobenzotriazole UV-5: 2- (2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl) benzotriazole UV-6: 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol)
UV-7: 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole UV-8: 2,4-dihydroxybenzophenone UV-9: 2,2'- Dihydroxy-4-methoxybenzophenone UV-10: 2-hydroxy-4-methoxy-5-sulfobenzophenone UV-11: Bis (2-methoxy-4-hydroxy-5-benzoylphenylmethane)
As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties. As the ultraviolet absorptivity of the optical film according to the present invention, the transmittance is preferably 10% or less, more preferably less than 6%, particularly preferably from 0 to 4 with respect to light having a wavelength of 380 nm. %.

  The content of the ultraviolet absorber used in the optical film is used in an appropriate amount according to the setting of the transmittance of light having a wavelength of 380 nm.

  As the antioxidant, a hindered phenol compound is preferably used. For example, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di- t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1 , 3,5-triazine, 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadec -3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) ) -Isocyanurate and the like. In particular, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] is preferred. Further, for example, hydrazine-based metal deactivators such as N, N′-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine and tris (2,4-di-t A phosphorus-based processing stabilizer such as -butylphenyl) phosphite may be used in combination. The amount of these compounds added is preferably 1 ppm to 1.0%, more preferably 10 to 1000 ppm in terms of mass ratio with respect to the cellulose ester.

  These antioxidants are also referred to as deterioration inhibitors. When a liquid crystal image display device or the like is placed in a high-humidity and high-temperature state, the cellulose ester film may deteriorate. For example, the amount of residual solvent in the cellulose ester film Since the cellulose ester film has a role of delaying or preventing the decomposition by the halogen or phosphoric acid of the phosphoric acid plasticizer, it is preferably contained in the cellulose ester film.

  Even when a multilayer thin film is laminated by the production method of the present invention, a uniform optical film can be obtained without unevenness of each layer.

  Thus, in the present invention, it is possible to provide an optical film on which thin films having various functions are formed.

  In the present invention, as the antistatic layer or the conductive layer, a layer having a film thickness of 0.1 to 2 μm coated with conductive resin fine particles such as metal oxide fine particles or a crosslinked cationic polymer may be provided.

  The optical film obtained by the method for producing an optical thin film of the present invention is particularly useful as a polarizing plate protective film, and a polarizing plate can be produced by a known method using this. Since these optical films have high thin film uniformity, they can be preferably used in various display devices, and excellent display performance can be obtained.

  If necessary, the optical film according to the present invention includes a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, a conductive layer, a light diffusion layer, an antifouling layer, an easy adhesion layer, an alignment layer, a liquid crystal layer, An optically anisotropic layer or the like can be provided alone or in appropriate combination as a functional layer. Specifically, an active ray curable resin layer is preferably used as the hard coat layer, and among them, an antireflection layer and an active ray curable resin layer are preferred as the functional layer.

  In general, a liquid crystal display device is preferably provided with a liquid crystal-containing substrate between two polarizing plates. In particular, the polarizing plate protective film on the outermost display side of the liquid crystal display device has a hard coat layer, an antiglare layer, and a reflective layer. Since a prevention layer etc. are provided, it is particularly preferable to use a polarizing plate for this portion.

(Hard coat layer)
The long film subjected to the treatment according to the present invention is preferably provided with a hard coat layer as a functional layer.

  The optical film of the present invention preferably comprises an antireflection film in which an antireflection layer (high refractive index layer, low refractive index layer, etc.) is provided on the hard coat layer.

  As described above, an actinic radiation curable resin layer is preferably used as the hard coat layer.

  The actinic radiation curable resin layer refers to a layer mainly composed of a resin that cures through a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays or electron beams. As the actinic radiation curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and a hard coat layer is formed by curing by irradiation with actinic radiation such as ultraviolet rays or electron beams. Typical examples of the actinic radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, and a resin curable by ultraviolet irradiation is preferable.

  As the ultraviolet curable resin, for example, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy resin is preferable. Used.

  UV curable acrylic urethane resins generally include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylates) in products obtained by reacting polyester polyols with isocyanate monomers or prepolymers. 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-A-59-151110 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 that are easily formed when 2-hydroxyethyl acrylate and 2-hydroxy acrylate monomers are generally reacted with polyester polyols. JP-A-59-151112 Can be used.

  Specific examples of the ultraviolet curable epoxy acrylate resin include an epoxy acrylate as an oligomer, a reactive diluent and a photoreaction initiator added thereto, and reacted to form an oligomer. The thing as described in 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. I can list them.

  Specific examples of the photoreaction initiator of these ultraviolet curable resins include benzoin and its derivatives, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. You may use with a photosensitizer. The photoinitiator can also be used as a photosensitizer. In addition, when using an epoxy acrylate photoinitiator, a sensitizer such as n-butylamine, triethylamine, or tri-n-butylphosphine can be used. The photoreaction initiator or photosensitizer used in the ultraviolet curable resin composition is 0.1 to 15 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the composition.

  Examples of the resin monomer include general monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, cyclohexyl acrylate, vinyl acetate, and styrene as monomers having one unsaturated double bond. In addition, monomers having two or more unsaturated double bonds include ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyldimethyl adiacrylate, and the above-mentioned trimethylolpropane. Examples thereof include triacrylate and pentaerythritol tetraacryl ester.

  Examples of commercially available ultraviolet curable resins that can be used in the present invention include ADEKA OPTMER KR / BY series: KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (Asahi Denka ( Co., Ltd.); Koeihard A-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, KRM7039, 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 (manufactured by Dainippon Ink & Chemicals, Inc.); 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.), etc. Can be selected as appropriate.

  Specific examples of compounds include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, and the like. .

  These actinic ray curable resin layers can be coated by 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.

As a light source for curing an ultraviolet curable resin by a photocuring reaction to form a cured coating layer, any light source that generates ultraviolet rays can be used without any 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. These light sources are preferably air-cooled or water-cooled. Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is preferably 5 to 500 mJ / cm ² , particularly preferably 20 to 150 mJ / cm ² .

  Further, it is preferable to reduce the oxygen concentration to 0.01% to 2% by nitrogen purge in the irradiated portion.

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

  Examples of the organic solvent for the UV curable resin layer composition coating solution include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl). Ketone), esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, other organic solvents, or a mixture thereof. Propylene glycol monoalkyl ether (1 to 4 carbon atoms of the alkyl group) or propylene glycol monoalkyl ether acetate ester (1 to 4 carbon atoms of the alkyl group) is 5% by mass or more, more preferably 5 to 80%. It is preferable to use the organic solvent containing at least mass%.

  In addition, it is particularly preferable to add a silicon compound to the ultraviolet curable resin layer composition coating solution. For example, polyether-modified silicone oil is preferably added. The number average molecular weight of the polyether-modified silicone oil is, for example, 1000 to 100000, preferably 2000 to 50000. If the number average molecular weight is less than 1000, the drying property of the coating film decreases, and conversely, the number average When the molecular weight exceeds 100,000, it tends to be difficult to bleed out to the coating surface.

  Commercially available silicon compounds include DKQ8-779 (trade name, manufactured by Dow Corning), SF3771, SF8410, SF8411, SF8419, SF8421, SF8428, SH200, SH510, SH1107, SH3749, SH3771, BX16-034, SH3746, SH3749, SH8400, SH3771M, SH3772M, SH3773M, SH3775M, BY-16-837, BY-16-839, BY-16-869, BY-16-870, BY-16-004, BY-16-891, BY-16 872, BY-16-874, BY22-008M, BY22-012M, FS-1265 (above, product names manufactured by Toray Dow Corning Silicone), KF-101, KF-100T, KF351, KF3 2, KF353, KF354, KF355, KF615, KF618, KF945, KF6004, Silicone X-22-945, X22-160AS (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), XF3940, XF3949 (trade name, manufactured by Toshiba Silicone Co., Ltd.) ), Disparon LS-009 (manufactured by Enomoto Kasei Co., Ltd.), Granol 410 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.), TSF4440, TSF4441, TSF4445, TSF4446, TSF4452, TSF4460 (manufactured by GE Toshiba Silicone), BYK-306, BYK- 330, BYK-307, BYK-341, BYK-344, BYK-361 (manufactured by BYK-Japan) L series (for example, L7001, L-7006, L-7604, L-9000) manufactured by Nippon Unicar Co., Ltd. Y Over's, FZ series (FZ-2203, FZ-2206, FZ-2207) and the like, it is preferably used.

  These components enhance the applicability to the substrate and the lower layer. When added to the outermost surface layer of the laminate, it not only improves the water repellency, oil repellency and antifouling properties of the coating film, but also exhibits an effect on the scratch resistance of the surface. These components are preferably added in a range of 0.01 to 3% by mass with respect to the solid component in the coating solution.

  As a coating method of the ultraviolet curable resin composition coating solution, the above-described methods can be used. The coating amount is suitably 0.1 to 30 μm, preferably 0.5 to 15 μm, as the wet film thickness. The dry film thickness is 0.1 to 20 μm, preferably 1 to 10 μm.

The ultraviolet curable resin composition is preferably irradiated with ultraviolet rays during or after coating and drying, and the irradiation time for obtaining the active ray irradiation amount of 5 to 150 mJ / cm ² is from 0.1 seconds to 5 seconds. Minutes are good, and 0.1 to 10 seconds is more preferable from the viewpoint of curing efficiency or work efficiency of the ultraviolet curable resin.

Moreover, it is preferable that the illuminance of these active ray irradiation parts is 50-150 mW / cm < ² >.

  In order to prevent blocking, to improve scratch resistance, to give antiglare property or light diffusibility, and to adjust the refractive index in the cured resin layer thus obtained, fine particles of an inorganic compound or an organic compound Can also be added.

  It is preferable to add fine particles to the hard coat layer used in the present invention, and as the inorganic fine particles used, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, magnesium oxide, calcium carbonate, calcium carbonate, talc, clay, Examples include calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. In particular, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, magnesium oxide and the like are preferably used.

  The organic fine particles include polymethacrylic acid methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, melamine resin powder. Polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, or polyfluoroethylene resin powder can be added to the ultraviolet curable resin composition. Particularly preferred are cross-linked polystyrene particles (for example, SX-130H, SX-200H, SX-350H, manufactured by Soken Chemical) and polymethyl methacrylate-based particles (for example, MX150, MX300, manufactured by Soken Chemical).

  The average particle diameter of these fine particle powders is preferably 0.005 to 5 μm, and particularly preferably 0.01 to 1 μm. As for the ratio of a ultraviolet curable resin composition and fine particle powder, it is desirable to mix | blend so that it may be 0.1-30 mass parts with respect to 100 mass parts of resin compositions.

  The ultraviolet curable resin layer is a clear hard coat layer having a center line average roughness (Ra) defined by JIS B 0601 of 1 to 50 nm or an antiglare layer having an Ra of about 0.1 to 1 μm. Is preferred. The center line average roughness (Ra) is preferably measured with an optical interference type surface roughness measuring instrument, and can be measured using, for example, RST / PLUS manufactured by WYKO.

The hard coat layer used in the present invention preferably contains an antistatic agent. Examples of the antistatic agent include Sn, Ti, In, Al, Zn, Si, Mg, Ba, Mo, W and A conductive material containing at least one element selected from the group consisting of V as a main component and having a volume resistivity of 10 ⁷ Ω · cm or less is preferable.

  Examples of the antistatic agent include metal oxides and composite oxides having the above elements.

Examples of metal oxides include, for example, ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₂ , V ₂ O ₅ , or complex oxides thereof. ZnO, In ₂ O ₃ , TiO ₂ and SnO ₂ are particularly preferable. Examples of containing different atoms include, for example, addition of Al and In to ZnO, addition of Nb and Ta to TiO ₂ , and addition of Sb, Nb and halogen elements to SnO ₂ . Addition is effective. The amount of these different atoms added is preferably in the range of 0.01 to 25 mol%, particularly preferably in the range of 0.1 to 15 mol%. In addition, the volume resistivity of these metal oxide powders having conductivity is 10 ⁷ Ω · cm or less, particularly 10 ⁵ Ω · cm or less.

  It is also preferable to provide an ultraviolet curable resin layer having irregularities by an embossing method using a mold roll (embossing roll) having irregularities formed on the surface, and to make this an antiglare layer.

(Antireflection layer)
The optical film of the present invention preferably further comprises an antireflection layer as a functional layer on the hard coat layer. In particular, a low refractive index layer containing hollow fine particles is preferable.

(Low refractive index layer)
The low refractive index layer used in the present invention preferably contains hollow fine particles, and more preferably contains a silicon alkoxide, a silane coupling agent, a curing agent and the like.

<Hollow particles>
The low refractive index layer preferably contains the following hollow fine particles.

  The hollow fine particles referred to here are (1) composite particles composed of porous particles and a coating layer provided on the surface of the porous particles, or (2) hollow inside, and the content is a solvent, gas or Cavity particles filled with a porous material. In addition, the coating liquid for low refractive index layers should just contain either (1) composite particle | grains or (2) cavity particle | grains, and may contain both.

  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. It is desirable that the average particle size of such inorganic fine particles is in the range of 5 to 300 nm, preferably 10 to 200 nm. The inorganic fine particles used are appropriately selected according to the thickness of the transparent film to be formed, and may be in the range of 2/3 to 1/10 of the film thickness of the formed transparent film such as a low refractive index layer. desirable. These inorganic fine particles are preferably used in a state of being dispersed in an appropriate medium in order to form a low refractive index layer. As the dispersion medium, water, alcohol (for example, methanol, ethanol, isopropyl alcohol), ketone (for example, methyl ethyl ketone, methyl isobutyl ketone), and ketone alcohol (for example, diacetone alcohol) are preferable.

  The thickness of the coating layer of the composite particles or the thickness of the particle walls of the hollow particles is desirably in the range of 1 to 20 nm, preferably 2 to 15 nm. In the case of composite particles, when the thickness of the coating layer is less than 1 nm, the particles may not be completely covered, and the low refractive index effect may not be sufficiently obtained. On the other hand, when the thickness of the coating layer exceeds 20 nm, the porosity (pore volume) of the composite particles may be lowered, and the low refractive index effect may not be sufficiently obtained. In the case of hollow particles, if the particle wall thickness is less than 1 nm, the particle shape may not be maintained, and even if the thickness exceeds 20 nm, the effect of low refractive index may not be sufficiently exhibited. is there.

The coating layer of the composite particles or the particle wall of the hollow particles preferably contains silica as a main component. The coating layer of the composite particle or the particle wall of the hollow particle may contain a component other than silica, specifically, Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO _2. and _{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 , WO _{3 and the} like. 1 type or 2 types or more can be mentioned. In such porous particles, the molar ratio MOX / SiO ₂ when the silica is represented by SiO ₂ and the inorganic compound other than silica is represented by oxide (MOX) is 0.0001 to 1.0, preferably It is desirable to be in the range of 0.001 to 0.3. It is difficult to obtain a porous particle having a molar ratio MOX / SiO ₂ of less than 0.0001, and even if it is obtained, conductivity is not exhibited. On the other hand, if the molar ratio MOX / SiO _{2 of} the porous particles exceeds 1.0, the ratio of silica decreases, so that particles having a small pore volume and a low refractive index may not be obtained.

  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.

  Incidentally, 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 inorganic fine particles, for example, the method for preparing composite oxide colloidal particles disclosed in paragraphs [0010] to [0033] of JP-A-7-133105 is suitably employed. Specifically, when the composite particles are composed of silica and an inorganic compound other than silica, the inorganic compound particles are produced from the following first to third steps.

First Step: Preparation of Porous Particle Precursor In the first step, an alkali aqueous solution of a silica raw material and an inorganic compound raw material other than silica is separately prepared in advance, or a silica raw material and an inorganic compound raw material other than silica are prepared. A mixed aqueous solution is prepared, and this aqueous solution is gradually added to an aqueous alkaline solution having a pH of 10 or more while stirring according to the composite ratio of the target composite oxide to prepare a porous particle precursor.

  As the silica raw material, alkali metal, ammonium or organic base silicate is used. Sodium silicate (water glass) or potassium silicate is used as the alkali metal silicate. Examples of the organic base include quaternary ammonium salts such as tetraethylammonium salt, and amines such as monoethanolamine, diethanolamine, and triethanolamine. The ammonium silicate or the organic base silicate includes an alkaline solution obtained by adding ammonia, a quaternary ammonium hydroxide, an amine compound or the like to a silicic acid solution.

  Moreover, the alkali-soluble conductive compound is used as a raw material for inorganic compounds other than silica.

Although the pH value of the mixed aqueous solution changes simultaneously with the addition of these aqueous solutions, an operation for controlling the pH value within a predetermined range is not particularly required. The aqueous solution finally has a pH value determined by the type of inorganic oxide and the mixing ratio thereof. There is no restriction | limiting in particular in the addition rate of the aqueous solution at this time. Further, in the production of composite oxide particles, a dispersion of seed particles can be used as a starting material. The seed particles are not particularly limited, but inorganic oxides such as SiO ₂ , Al ₂ O ₃ , TiO ₂ or ZrO ₂ or fine particles of these composite oxides are used. Usually, these sols are used. I can do it. Furthermore, the porous particle precursor dispersion obtained by the above production method may be used as a seed particle dispersion. When the seed particle dispersion is used, the pH of the seed particle dispersion is adjusted to 10 or more, and then the aqueous solution of the compound is added to the above-described alkaline aqueous solution while stirring. Also in this case, it is not always necessary to control the pH of the dispersion. In this way, when seed particles are used, it is easy to control the particle size of the porous particles to be prepared, and particles with uniform particle sizes can be obtained.

  The silica raw material and the inorganic compound raw material described above have high solubility on the alkali side. However, when both are mixed in this highly soluble pH region, the solubility of oxo acid ions such as silicate ions and aluminate ions decreases, and these composites precipitate and grow into fine particles, or seed particles. Particle deposition occurs on the top. Therefore, it is not always necessary to perform pH control as in the conventional method for precipitation and growth of fine particles.

The composite ratio of silica and inorganic compound other than silica in the first step is that the inorganic compound relative to silica is converted to oxide (MOx), and the molar ratio of MOx / SiO ₂ is 0.05 to 2.0, preferably It is desirable to be within the range of 0.2 to 2.0. Within this range, the pore volume of the porous particles increases as the proportion of silica decreases. However, even when the molar ratio exceeds 2.0, the pore volume of the porous particles hardly increases. On the other hand, when the molar ratio is less than 0.05, the pore volume becomes small. When preparing hollow particles, the molar ratio of MOx / SiO ₂ is preferably in the range of 0.25 to 2.0.

Second step: Removal of inorganic compound other than silica from porous particles In the second step, inorganic compounds other than silica (elements other than silicon and oxygen) are obtained from the porous particle precursor obtained in the first step. At least a portion is selectively removed. As a specific removal method, the inorganic compound in the porous particle precursor is dissolved and removed using a mineral acid or an organic acid, or is contacted with a cation exchange resin for ion exchange removal.

  The porous particle precursor obtained in the first step is a particle having a network structure in which silicon and an inorganic compound constituent element are bonded via oxygen. By removing the inorganic compound (elements other than silicon and oxygen) from the porous particle precursor in this way, porous particles having a larger porosity and a larger pore volume can be obtained. Further, if the amount of removing the inorganic oxide (elements other than silicon and oxygen) from the porous particle precursor is increased, the hollow particles can be prepared.

  In addition, prior to removing inorganic compounds other than silica from the porous particle precursor, a silicic acid solution obtained by removing the alkali metal salt of silica from the porous particle precursor dispersion obtained in the first step. Alternatively, it is preferable to form a silica protective film by adding a hydrolyzable organosilicon compound. The thickness of the silica protective film may be 0.5 to 15 nm. Even if the silica protective film is formed, the protective film in this step is porous and thin, so that it is possible to remove inorganic compounds other than silica described above from the porous particle precursor.

  By forming such a silica protective film, inorganic compounds other than silica described above can be removed from the porous particle precursor while maintaining the particle shape. Further, when forming the silica coating layer described later, the pores of the porous particles are not blocked by the coating layer, and therefore the silica coating layer described later is formed without reducing the pore volume. I can do it. Note that when the amount of the inorganic compound to be removed is small, the particles are not broken, and thus it is not always necessary to form a protective film.

  When preparing hollow particles, it is desirable to form this silica protective film. When preparing the hollow particles, the inorganic compound is removed to obtain a hollow particle precursor composed of a silica protective film, a solvent in the silica protective film, and an undissolved porous solid content. When a coating layer to be described later is formed on the precursor, the formed coating layer becomes a particle wall to form hollow particles.

The amount of the silica source added for forming the silica protective film is preferably small as long as the particle shape can be maintained. If the amount of the silica source is too large, the silica protective film becomes too thick, and it may be difficult to remove inorganic compounds other than silica from the porous particle precursor. The hydrolyzable organic silicon compound used for the silica protective film formed of the general formula _{R n Si (OR ') 4} -n [R, R': an alkyl group, an aryl group, a vinyl group, such as acrylic group An alkoxysilane represented by a hydrocarbon group, n = 0, 1, 2, or 3] can be used. In particular, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane are preferably used.

  As an addition method, a solution obtained by adding a small amount of alkali or acid as a catalyst to a mixed solution of these alkoxysilane, pure water, and alcohol is added to the dispersion of the porous particles, and the alkoxysilane is hydrolyzed. The produced silicic acid polymer is deposited on the surface of the inorganic oxide particles. At this time, alkoxysilane, alcohol, and catalyst may be simultaneously added to the dispersion. As the alkali catalyst, ammonia, an alkali metal hydroxide, or an amine can be used. As the acid catalyst, various inorganic acids and organic acids can be used.

  When the dispersion medium of the porous particle precursor is water alone or the ratio of water to the organic solvent is high, it is possible to form a silica protective film using a silicic acid solution. When a silicic acid solution is used, a predetermined amount of the silicic acid solution is added to the dispersion, and at the same time an alkali is added to deposit the silicic acid solution on the surface of the porous particles. In addition, you may produce a silica protective film together using a silicic acid liquid and the said alkoxysilane.

Third step: Formation of silica coating layer In the third step, a hydrolyzable organosilicon compound or silicic acid solution is added to the porous particle dispersion prepared in the second step (in the case of hollow particles, a hollow particle precursor dispersion). Is added to coat the surface of the particles with a polymer such as a hydrolyzable organosilicon compound or a silicic acid solution to form a silica coating layer.

The hydrolyzable organic silicon compound used for the silica coating layer formed, the above-mentioned such general formula _{R n Si (OR ') 4} -n [R, R': an alkyl group, an aryl group, a vinyl group, An alkoxysilane represented by a hydrocarbon group such as an acryl group, n = 0, 1, 2, or 3] can be used. In particular, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane are preferably used.

  As an addition method, a solution obtained by adding a small amount of alkali or acid as a catalyst to a mixed solution of these alkoxysilanes, pure water, and alcohol is used as a dispersion of the porous particles (in the case of hollow particles, hollow particle precursor). In addition, the silicic acid polymer produced by hydrolyzing alkoxysilane is deposited on the surface of the porous particles (in the case of hollow particles, hollow particle precursors). At this time, alkoxysilane, alcohol, and catalyst may be simultaneously added to the dispersion. As the alkali catalyst, ammonia, an alkali metal hydroxide, or an amine can be used. As the acid catalyst, various inorganic acids and organic acids can be used.

  When the dispersion medium of the porous particles (cavity particle precursor in the case of hollow particles) is water alone or a mixed solvent with an organic solvent and the mixed solvent has a high ratio of water to the organic solvent, a silicate solution You may form a coating layer using. The silicic acid solution is an aqueous solution of a low silicic acid polymer obtained by dealkalizing an aqueous solution of an alkali metal silicate such as water glass by ion exchange treatment.

  The silicic acid solution is added to the dispersion of porous particles (in the case of hollow particles, hollow particle precursors), and at the same time, alkali is added to make the low-silicic acid polymer into porous particles (in the case of hollow particles, hollow particle precursors). ) Deposit on the surface. A silicic acid solution may be used in combination with the alkoxysilane for forming a coating layer. The addition amount of the organosilicon compound or silicic acid solution used for forming the coating layer only needs to be sufficient to cover the surface of the colloidal particles, and the finally obtained silica coating layer has a thickness of 1 to 20 nm. In such an amount, it is added in a dispersion of porous particles (in the case of hollow particles, hollow particle precursor) in a dispersion. When the silica protective film is formed, the organosilicon compound or the silicate solution is added in such an amount that the total thickness of the silica protective film and the silica coating layer is in the range of 1 to 20 nm.

  Next, the dispersion liquid of the particles on which the coating layer is formed is heat-treated. By the heat treatment, in the case of porous particles, the silica coating layer covering the surface of the porous particles is densified, and a dispersion of composite particles in which the porous particles are coated with the silica coating layer is obtained. In the case of the hollow particle precursor, the formed coating layer is densified to form hollow particle walls, and a dispersion of hollow particles having cavities filled with a solvent, gas, or porous solid content is obtained.

  The heat treatment temperature at this time is not particularly limited as long as it can close the fine pores of the silica coating layer, and is preferably in the range of 80 to 300 ° C. When the heat treatment temperature is less than 80 ° C., the fine pores of the silica coating layer may not be completely closed and densified, and the treatment time may take a long time. Further, when the heat treatment temperature exceeds 300 ° C. for a long time, fine particles may be formed, and the effect of low refractive index may not be obtained.

  The refractive index of the inorganic fine particles thus obtained is as low as less than 1.44. Such inorganic fine particles are presumed to have a low refractive index because the porosity inside the porous particles is maintained or the inside is hollow.

The low refractive index layer used in the present invention preferably contains a hydrolyzate of an alkoxysilicon compound and a condensate formed by a subsequent condensation reaction in addition to the hollow fine particles. In particular, it is preferable to contain a SiO ₂ sol prepared by adjusting an alkoxysilicon compound represented by the following general formula (3) and / or (4) or a hydrolyzate thereof.

Formula (3) R1-Si (OR2) ₃
General formula (4) Si (OR2) ₄
(In the formula, R1 represents a methyl group, an ethyl group, a vinyl group, or an organic group containing an acryloyl group, a methacryloyl group, an amino group or an epoxy group, and R2 represents a methyl group or an ethyl group)
Hydrolysis of the silicon alkoxide and silane coupling agent is performed by dissolving the silicon alkoxide and silane coupling agent in a suitable solvent. Examples of the solvent to be used include ketones such as methyl ethyl ketone, alcohols such as methanol, ethanol and isopropyl alcohol butanol, esters such as ethyl acetate, and mixtures thereof.

  To the solution obtained by dissolving the silicon alkoxide or the silane coupling agent in a solvent, an amount of water slightly larger than that required for hydrolysis is added, and the temperature is 15 to 35 ° C., preferably 20 to 30 ° C. for 1 to 48 hours. The stirring is preferably performed for 3 to 36 hours.

  In the hydrolysis, a catalyst is preferably used. As such a catalyst, an acid such as hydrochloric acid, nitric acid, sulfuric acid or acetic acid is preferably used. These acids are used in an aqueous solution of about 0.001N to 20.0N, preferably about 0.005 to 5.0N. The water in the catalyst aqueous solution can be water for hydrolysis.

  The alkoxy silicon compound is hydrolyzed for a predetermined time, the prepared alkoxy silicon hydrolyzed solution is diluted with a solvent, and other necessary additives are mixed to prepare a coating solution for a low refractive index layer. The low refractive index layer can be formed on the base material by applying and drying on a base material such as a film.

<Alkoxy silicon compound>
In the present invention, the alkoxy silicon compound (hereinafter also referred to as alkoxysilane) used for the preparation of the low refractive index layer coating solution is preferably represented by the following general formula (5).

Formula (5) R (4-n) Si (OR ′) n
In the general formula, R ′ represents an alkyl group, R represents a hydrogen atom or a monovalent substituent, and n represents 3 or 4.

  Examples of the alkyl group represented by R ′ include groups such as a methyl group, an ethyl group, a propyl group, and a butyl group, which may have a substituent, and the substituent exhibits properties as an alkoxysilane. If it is, there is no restriction | limiting in particular, For example, although you may substitute by halogen atoms, such as a fluorine, an alkoxy group, etc., More preferably, it is an unsubstituted alkyl group, and especially a methyl group and an ethyl group are preferable.

  The monovalent substituent represented by R is not particularly limited, and examples thereof include an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an aromatic heterocyclic group, and a silyl group. Of these, an alkyl group, a cycloalkyl group, and an alkenyl group are preferable. These may be further substituted. Examples of the substituent for R include a halogen atom such as a fluorine atom and a chlorine atom, an amino group, an epoxy group, a mercapto group, a hydroxyl group, and an acetoxy group.

Specific preferred examples of the alkoxysilane represented by the general formula include tetramethoxysilane, tetraethoxysilane (TEOS), tetra n-propoxy silane, tetraisopropoxy silane, tetra n-butoxy silane, tetra t- Butoxysilane, tetrakis (methoxyethoxy) silane, tetrakis (methoxypropoxy) silane,
Further, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxysilane, i-butyltrimethoxysilane, n-hexyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3 -Mercaptopropyltrimethoxysilane, acetoxytriethoxysilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trimethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, (3, 3, - trifluoropropyl) trimethoxysilane, pentafluorophenyl phenylpropyl trimethoxysilane, further, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane and the like.

  Alternatively, quantified silicon compounds such as silicate 40, silicate 45, silicate 48, and M silicate 51 manufactured by Tama Chemical, in which these compounds are partially condensed may be used.

  Since the alkoxysilane has a silicon alkoxide group that can be hydrolyzed and polycondensed, these alkoxysilanes are crosslinked by hydrolysis and condensation to form a network structure of the polymer compound. A layer containing uniform silicon oxide is formed on the base material by applying it on the base material and drying it as a refractive index layer coating solution.

  The hydrolysis reaction can be carried out by a known method and dissolved in the presence of a predetermined amount of water and a hydrophilic organic solvent such as methanol, ethanol or acetonitrile so that the hydrophobic alkoxysilane and water can be easily mixed. -After mixing, a hydrolysis catalyst is added to hydrolyze and condense the alkoxysilane. Usually, by carrying out hydrolysis and condensation reaction at 10 ° C. to 100 ° C., a liquid silicate oligomer having two or more hydroxyl groups is generated, and a hydrolyzed solution is formed. The degree of hydrolysis can be appropriately adjusted depending on the amount of water used.

  In the present invention, as a solvent to be added to alkoxysilane together with water, methanol and ethanol are preferable because they are inexpensive and the properties of the resulting film are excellent and the hardness is good. Although isopropanol, n-butanol, isobutanol, octanol, and the like can be used, the hardness of the obtained film tends to be low. The amount of the solvent is 50 to 400 parts by mass, preferably 100 to 250 parts by mass with respect to 100 parts by mass of the tetraalkoxysilane before hydrolysis.

  In this way, a hydrolyzed solution is prepared, diluted with a solvent, and if necessary, an additive is added and mixed with components necessary to form a low refractive index layer coating solution. A coating solution is used.

<Hydrolysis catalyst>
Examples of the hydrolysis catalyst include acids, alkalis, organic metals, metal alkoxides, etc. In the present invention, inorganic acids or organic acids such as sulfuric acid, hydrochloric acid, nitric acid, hypochlorous acid, and boric acid are preferable. In particular, carboxylic acids such as nitric acid and acetic acid, polyacrylic acid, benzenesulfonic acid, paratoluenesulfonic acid, methylsulfonic acid and the like are preferable, and among these, nitric acid, acetic acid, citric acid, tartaric acid and the like are preferably used. In addition to the citric acid and tartaric acid, levulinic acid, formic acid, propionic acid, malic acid, succinic acid, methyl succinic acid, fumaric acid, oxaloacetic acid, pyruvic acid, 2-oxoglutaric acid, glycolic acid, D-glyceric acid, D- Gluconic acid, malonic acid, maleic acid, oxalic acid, isocitric acid, lactic acid and the like are also preferably used.

  Of these, those which volatilize the acid during drying and do not remain in the film are preferred, and those having a low boiling point are preferred. Therefore, acetic acid and nitric acid are particularly preferable.

  The added amount is 0.001 to 10 parts by mass, preferably 0.005 to 5 parts by mass with respect to 100 parts by mass of the alkoxysilicon compound (for example, tetraalkoxysilane) to be used. In addition, the amount of water added may be equal to or greater than the amount that the partial hydrolyzate can theoretically hydrolyze to 100%, and an amount equivalent to 100 to 300%, preferably an amount equivalent to 100 to 200% is added.

  When the alkoxysilane is hydrolyzed, the following inorganic fine particles are preferably mixed.

  The hydrolysis solution is allowed to stand for a predetermined time after the start of hydrolysis, and used after the progress of hydrolysis reaches a predetermined level. The standing time is a time during which the above-described crosslinking by hydrolysis and condensation proceeds sufficiently to obtain desired film characteristics. Specifically, depending on the type of acid catalyst used, for example, acetic acid is preferably 15 hours or more at room temperature, and nitric acid is preferably 2 hours or more. The aging temperature affects the aging time. Generally, the aging proceeds quickly at high temperatures, but when heated to 100 ° C. or higher, gelation occurs, so heating at 20 to 60 ° C. and keeping the temperature are appropriate.

  The above-mentioned hollow fine particles and additives are added to the silicate oligomer solution formed by hydrolysis and condensation in this way, and necessary dilution is performed to prepare a low refractive index layer coating solution, which is applied onto the above-described film. By drying, a layer containing an excellent silicon oxide film as a low refractive index layer can be formed.

  In the present invention, in addition to the above alkoxysilane, for example, a modified product modified with a silane compound (monomer, oligomer, polymer) having a functional group such as an epoxy group, an amino group, an isocyanate group, or a carboxyl group. It may be used alone or in combination.

<Fluorine compound>
The low refractive index layer used in the present invention may be composed of a fluorine compound as a main component, and particularly preferably contains hollow fine particles and a fluorine compound. The binder matrix preferably contains a fluorine-containing resin that is crosslinked by heat or ionizing radiation (hereinafter also referred to as “fluorine-containing resin before crosslinking”). By including the fluorine-containing resin, a good antifouling antireflection film can be provided.

  Preferred examples of the fluorine-containing resin before crosslinking include a fluorine-containing copolymer formed from a fluorine-containing vinyl monomer and a monomer for imparting a crosslinkable group. Specific examples of the fluorine-containing vinyl monomer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3 -Dioxoles, etc.), (meth) acrylic acid partial or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) and M-2020 (manufactured by Daikin)), fully or partially fluorinated vinyl ethers Is mentioned. Monomers for imparting a crosslinkable group include glycidyl methacrylate, vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, vinyl glycidyl ether, and other vinyl monomers having a crosslinkable functional group in advance in the molecule. , Vinyl monomers having a carboxyl group, hydroxyl group, amino group, sulfonic acid group, etc. (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyalkyl vinyl ether, hydroxyalkyl allyl) Ether, etc.). The latter can introduce a crosslinked structure after copolymerization by adding a compound that reacts with a functional group in the polymer and one or more reactive groups. No. 147739. Examples of the crosslinkable group include acryloyl, methacryloyl, isocyanate, epoxy, aziridine, oxazoline, aldehyde, carbonyl, hydrazine, carboxyl, methylol, and active methylene group. When the fluorine-containing copolymer is cross-linked by heating by a cross-linking group that reacts by heating, or a combination of an ethylenically unsaturated group and a thermal radical generator or an epoxy group and a thermal acid generator, the thermosetting type In the case of crosslinking by irradiation with light (preferably ultraviolet rays, electron beams, etc.) by a combination of an ethylenically unsaturated group and a photo radical generator, or an epoxy group and a photo acid generator, etc., it is an ionizing radiation curable type. .

  Further, in addition to the above monomers, a fluorine-containing copolymer formed by using a monomer other than the fluorine-containing vinyl monomer and the monomer for imparting a crosslinkable group may be used as the fluorine-containing resin before crosslinking. The monomer that can be used in combination is not particularly limited. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, 2-acrylic acid 2- Ethyl hexyl), methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyl toluene, α-methylstyrene, etc.), vinyl ethers (methyl vinyl ether) Etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate, etc.), acrylamides (N-tertbutylacrylamide, N-cyclohexylacrylamide, etc.), methacrylamides, Ronitoriru derivatives and the like can be mentioned. In addition, it is also preferable to introduce a polyorganosiloxane skeleton or a perfluoropolyether skeleton into the fluorinated copolymer in order to impart slipperiness and antifouling properties. For example, polyorganosiloxane or perfluoropolyether having an acrylic group, methacrylic group, vinyl ether group, styryl group or the like at the terminal is polymerized with the above monomer, and polyorganosiloxane or perfluoropolyester having a radical generating group at the terminal. It can be obtained by polymerization of the above monomers with ether, reaction of a polyorganosiloxane or perfluoropolyether having a functional group with a fluorine-containing copolymer, or the like.

  The proportion of each of the above monomers used to form the fluorinated copolymer before crosslinking is preferably 20 to 70 mol%, more preferably 40 to 70 mol%, more preferably 40 to 70 mol% of the fluorinated vinyl monomer. The amount of the monomer is preferably 1 to 20 mol%, more preferably 5 to 20 mol%, and the other monomer used in combination is preferably 10 to 70 mol%, more preferably 10 to 50 mol%.

  The fluorine-containing copolymer can be obtained by polymerizing these monomers in the presence of a radical polymerization initiator by means such as solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization.

  The fluorine-containing resin before crosslinking is commercially available and can be used. Examples of commercially available fluorine-containing resins before cross-linking include Cytop (Asahi Glass), Teflon (registered trademark) AF (DuPont), polyvinylidene fluoride, Lumiflon (Asahi Glass), Opstar (JSR), etc. Can be mentioned.

  The low refractive index layer containing a cross-linked fluororesin as a constituent component preferably has a dynamic friction coefficient in the range of 0.03 to 0.15 and a contact angle with water in the range of 90 to 120 degrees.

<Additive>
If necessary, the low refractive index layer coating solution may further contain additives such as a silane coupling agent and a curing agent. Specific examples of the silane coupling agent include vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and 3- (2-aminoethylaminopropyl) trimethoxysilane. Can be mentioned.

  Examples of the curing agent include organic acid metal salts such as sodium acetate and lithium acetate, and sodium acetate is particularly preferable. The amount of addition to the silicon alkoxysilane hydrolysis solution is preferably in the range of about 0.1 to 1 part by mass with respect to 100 parts by mass of the solid content present in the hydrolysis solution.

  Moreover, it is preferable to add low surface tension substances such as various leveling agents, surfactants, and silicone oils to the coating solution for the low refractive index layer used in the present invention.

  Specific examples of the silicone oil include L-45, L-9300, FZ-3704, FZ-3703, FZ-3720, FZ-3786, FZ-3501, and FZ-3504 of Nippon Unicar Co., Ltd. , FZ-3508, FZ-3705, FZ-3707, FZ-3710, FZ-3750, FZ-3760, FZ-3785, FZ-3785, Y-7499, Shin-Etsu Chemical KF96L, KF96, KF96H, KF99, KF54 , KF965, KF968, KF56, KF995, KF351, KF352, KF353, KF354, KF355, KF615, KF618, KF945, KF6004, FL100 and the like.

  These components enhance the applicability to the substrate and the lower layer. When added to the outermost surface layer of the laminate, it not only improves the water repellency, oil repellency and antifouling properties of the coating film, but also exhibits an effect on the scratch resistance of the surface. When these components are added in an excessive amount, they cause repelling during coating. Therefore, it is preferable to add them in a range of 0.01 to 3% by mass with respect to the solid component in the coating solution.

<solvent>
Solvents used in the coating solution for coating the low refractive index layer are alcohols such as methanol, ethanol, 1-propanol, 2-propanol and butanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone; benzene, toluene, Aromatic hydrocarbons such as xylene; glycols such as ethylene glycol, propylene glycol, hexylene glycol; ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, diethyl cellosolve, diethyl carbitol, propylene glycol monomethyl Examples include glycol ethers such as ether; N-methylpyrrolidone, dimethylformamide, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, water, etc., and these may be used alone or in combination of two or more. That.

<Application method>
As a method of applying the low refractive index layer, known methods such as dipping, spin coating, knife coating, bar coating, air doctor coating, blade coating, squeeze coating, reverse roll coating, gravure roll coating, curtain coating, spray coating, die coating, etc. A coating method or a known inkjet method can be used, and a coating method capable of continuous coating or thin film coating is preferably used. The coating amount is suitably 0.1 to 30 μm, preferably 0.5 to 15 μm in terms of wet film thickness. The coating speed is preferably 10 to 80 m / min.

  When the composition of the present invention is applied to a substrate, the thickness of the layer, coating uniformity, and the like can be controlled by adjusting the solid content concentration and the coating amount in the coating solution.

  In the present invention, it is also preferable to further provide the following medium refractive index layer and high refractive index layer to form an antireflection layer having a plurality of layers.

  Although the structural example of the antireflection layer which can be used for this invention is shown below, it is not limited to these.

Long film / hard coat layer / low refractive index layer Long film / hard coat layer / medium refractive index layer / low refractive index layer Long film / hard coat layer / high refractive index layer / low refractive index layer Long film / Hard coat layer / Medium refractive index layer / High refractive index layer / Low refractive index layer Long film / Antistatic layer / Hard coat layer / Medium refractive index layer / High refractive index layer / Low refractive index layer Long film / Hard coat Layer / antistatic layer / medium refractive index layer / high refractive index layer / low refractive index layer antistatic layer / long film / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer long film / Hard coat layer / high refractive index layer / low refractive index layer / high refractive index layer / low refractive index layer (medium refractive index layer, high refractive index layer)
The medium refractive index layer and the high refractive index layer are not particularly limited as long as a predetermined refractive index layer is obtained, but are preferably composed of metal oxide fine particles, a binder and the like having the following high refractive index. In addition, you may contain an additive. The refractive index of the middle refractive index layer is preferably 1.55 to 1.75, and the refractive index of the high refractive index layer is preferably 1.75 to 2.20. The thickness of the high refractive index layer and the medium refractive index layer is preferably 5 nm to 1 μm, more preferably 10 nm to 0.2 μm, and most preferably 30 nm to 0.1 μm. The coating can be performed in the same manner as the coating method for the low refractive index layer.

<Metal oxide fine particles>
Although metal oxide fine particles are not particularly limited, for example, titanium dioxide, aluminum oxide (alumina), zirconium oxide (zirconia), zinc oxide, antimony-doped tin oxide (ATO), antimony pentoxide, indium-tin oxide (ITO), Iron oxide or the like can be used as a main component. A mixture of these may also be used. When titanium dioxide is used, photocatalytic activity can be achieved by using metal oxide particles having a core / shell structure in which titanium dioxide is the core and the shell is coated with alumina, silica, zirconia, ATO, ITO, antimony pentoxide, or the like. It is preferable in terms of suppression.

  The refractive index of the metal oxide fine particles is preferably 1.80 to 2.60, more preferably 1.90 to 2.50. The average particle diameter of the primary particles of the metal oxide fine particles is 5 nm to 200 nm, more preferably 10 to 150 nm. If the particle size is too small, the metal oxide fine particles tend to aggregate and the dispersibility deteriorates. If the particle size is too large, the haze increases, which is not preferable. The shape of the inorganic fine particles is preferably a rice grain shape, a needle shape, a spherical shape, a cubic shape, a spindle shape or an indefinite shape.

  The metal oxide fine particles may be surface-treated with an organic compound. Examples of the organic compound used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Among these, the silane coupling agent described later is most preferable. Two or more kinds of surface treatments may be combined.

  By appropriately selecting the kind and addition ratio of the metal oxide, a high refractive index layer and a medium refractive index layer having a desired refractive index can be obtained.

<Binder>
The binder is added to improve the film formability and physical properties of the coating film. As the binder, for example, the aforementioned ionizing radiation curable resin, acrylamide derivative, polyfunctional acrylate, acrylic resin or methacrylic resin can be used.

(Metal compounds, silane coupling agents)
As other additives, a metal compound, a silane coupling agent, or the like may be added. Metal compounds and silane coupling agents can also be used as binders.

  As the metal compound, a compound represented by the following general formula (6) or a chelate compound thereof can be used.

General formula (6): AnMBx-n
In the formula, M represents a metal atom, A represents a hydrolyzable functional group or a hydrocarbon group having a hydrolyzable functional group, and B represents an atomic group covalently or ionically bonded to the metal atom M. x represents the valence of the metal atom M, and n represents an integer of 2 or more and x or less.

  Examples of the hydrolyzable functional group A include halogens such as alkoxyl groups and chloro atoms, ester groups and amide groups. The metal compound belonging to the above formula (6) includes an alkoxide having two or more alkoxyl groups bonded directly to a metal atom, or a chelate compound thereof. Preferable metal compounds include titanium alkoxides, zirconium alkoxides, silicon alkoxides, and chelate compounds thereof from the viewpoints of the effect of reinforcing the refractive index and coating film strength, ease of handling, material cost, and the like. Titanium alkoxide has a high reaction rate and a high refractive index and is easy to handle. However, since it has a photocatalytic action, its light resistance deteriorates when added in a large amount. Zirconium alkoxide has a high refractive index but tends to become cloudy, so care must be taken in dew point management during coating. Silicon alkoxide has a slow reaction rate and a low refractive index, but is easy to handle and has excellent light resistance. Since the silane coupling agent can react with both the inorganic fine particles and the organic polymer, a tough coating film can be formed. Moreover, since titanium alkoxide has the effect of accelerating the reaction of the ultraviolet curable resin and metal alkoxide, the physical properties of the coating film can be improved by adding a small amount.

  Examples of the titanium alkoxide include tetramethoxy titanium, tetraethoxy titanium, tetra-iso-propoxy titanium, tetra-n-propoxy titanium, tetra-n-butoxy titanium, tetra-sec-butoxy titanium, tetra-tert-butoxy titanium, and the like. Is mentioned.

  Examples of the zirconium alkoxide include tetramethoxy zirconium, tetraethoxy zirconium, tetra-iso-propoxy zirconium, tetra-n-propoxy zirconium, tetra-n-butoxy zirconium, tetra-sec-butoxy zirconium, tetra-tert-butoxy zirconium and the like. Is mentioned.

  The silicon alkoxide and the silane coupling agent are compounds represented by the following general formula (7).

Formula (7): RmSi (OR ′) n
In the formula, R is an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms), or a reaction such as a vinyl group, a (meth) acryloyl group, an epoxy group, an amide group, a sulfonyl group, a hydroxyl group, a carboxyl group, or an alkoxyl group. R ′ represents an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms), and m + n is 4.

  Specifically, tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, tetrapenta Ethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, hexyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane , Γ-glycidoxypropyltrimethoxysilane, 3- (2-aminoethylaminopropyl) trimethoxysilane and the like.

  Preferred chelating agents for forming a chelate compound by coordination with a free metal compound include alkanolamines such as diethanolamine and triethanolamine, glycols such as ethylene glycol, diethylene glycol and propylene glycol, acetylacetone and acetoacetic acid. Examples thereof include ethyl and the like having a molecular weight of 10,000 or less. By using these chelating agents, it is possible to form a chelate compound that is stable against moisture mixing and is excellent in the effect of reinforcing the coating film.

  The addition amount of the metal compound is preferably less than 5% by mass in terms of metal oxide in the medium refractive index composition, and less than 20% by mass in terms of metal oxide in the high refractive index composition. Is preferred.

(Polarizer)
The optical film of the present invention is useful as a polarizing plate protective film, and the polarizing plate can be produced by a general method. The optical film of the present invention is preferably bonded to at least one surface of a polarizing film prepared by subjecting the back side of the optical film to alkali saponification treatment and immersion drawing in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. The optical film may be used on the other surface, or another polarizing plate protective film may be used. Commercially available cellulose ester films (for example, Konica Minoltak KC8UX, KC4UX, KC5UX, KC8UCR3, KC8UCR4, KC8UY, KC4UY, KC12UR, KC8UCR-3, KC8UCR-4, KC8UCR-5, and above, preferably Konica Minolta Co., Ltd.) Used. The polarizing plate protective film used on the other surface of the optical film of the present invention preferably has an in-plane retardation Ro of 590 nm, a phase difference of 30 to 300 nm, and Rt of 70 to 400 nm. . These can be produced, for example, by the methods described in JP-A-2002-71957 and JP-A-2003-170492. For example, it is also preferable to use a polarizing plate protective film having retardation values Ro and Rt produced by the method described in JP-A No. 2003-12859, each satisfying −15 nm ≦ Ro ≦ 15 nm and −15 nm ≦ Rt ≦ 15 nm. Alternatively, it is preferable to use a polarizing plate protective film that also serves as an optical compensation film having an optically anisotropic layer formed by aligning a liquid crystal compound such as a discotic liquid crystal. For example, the optically anisotropic layer can be formed by the method described in JP-A-2003-98348. By using in combination with the optical film of the present invention, a polarizing plate having excellent flatness and a stable viewing angle expansion effect can be obtained.

  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 one in which iodine is dyed on a system film and one in which dichroic dye is dyed. 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. The thickness of the polarizing film is preferably 5 to 30 μm, particularly preferably 10 to 20 μm.

  Further, the ethylene unit content described in JP-A-2003-248123, JP-A-2003-342322, etc. is 1 to 4 mol%, the degree of polymerization is 2000 to 4000, and the degree of saponification is 99.0 to 99.99 mol%. Ethylene-modified polyvinyl alcohol is also preferably used. Among them, an ethylene-modified polyvinyl alcohol film having a hot water cutting temperature of 66 to 73 ° C. is preferably used. The difference in hot water cutting temperature between two points 5 cm away in the TD direction of the film is more preferably 1 ° C. or less in order to reduce color spots, and two points separated 1 cm in the TD direction of the film. In order to reduce color spots, it is more preferable that the difference in the hot water cutting temperature is 0.5 ° C. or less.

  A polarizing film using this ethylene-modified polyvinyl alcohol film is excellent in polarizing performance and durability, and has few color spots, and is particularly preferably used for a large liquid crystal display device.

  The polarizing film obtained as described above is usually used as a polarizing plate with a polarizing plate protective film bonded to both sides or one side. Examples of the adhesive used for pasting include a PVA-based adhesive and a urethane-based adhesive. Among them, a PVA-based adhesive is preferably used.

(Display device)
By incorporating a polarizing plate using the optical film of the present invention into a display device, various display devices with excellent visibility can be manufactured. The optical film of the present invention is preferably a reflective, transmissive, transflective LCD, or TN, STN, OCB, HAN, VA (PVA, MVA), IPS, or other driving LCD. Used. The optical film of the present invention is excellent in flatness and is preferably used for various display devices such as a plasma display, a field emission display, an organic EL display, an inorganic EL display, and electronic paper. In particular, in a large-screen display device having a screen size of 30 or more, especially 30 to 54, there is no white spot in the periphery of the screen, and the effect is maintained for a long time, and a remarkable effect is obtained in the MVA liquid crystal display device. Is recognized. In particular, there was little color unevenness, glare and wavy unevenness, which is the object of the present invention.

  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 cellulose ester films 1-3>
(Silicon dioxide dispersion A)
Aerosil 972V (manufactured by Nippon Aerosil Co., Ltd.) 12 parts by mass (average primary particle diameter 16 nm, apparent specific gravity 90 g / liter)
88 parts by mass of ethanol or more was stirred and mixed with a dissolver for 30 minutes, and then dispersed with Manton Gorin. The liquid turbidity after dispersion was 200 ppm. 88 parts by mass of methylene chloride was added to the silicon dioxide dispersion while stirring, and the mixture was stirred and mixed with a dissolver for 30 minutes to prepare a silicon dioxide dispersion dilution A.

(Preparation of inline additive solution A)
Tinuvin 109 (manufactured by Ciba Specialty Chemicals) 11 parts by weight Tinuvin 171 (manufactured by Ciba Specialty Chemicals) 5 parts by weight 100 parts by weight of methylene chloride Dissolved and filtered.

To this, 36 parts by mass of silicon dioxide dispersion diluent A was added with stirring, and after further stirring for 30 minutes, cellulose acetate propionate (acetyl group substitution degree 1.9, propionyl group substitution degree 0.8) 6 masses. The mixture was added with stirring, and further stirred for 60 minutes, and then filtered through a polypropylene wind cartridge filter TCW-PPS-1N manufactured by Advantech Toyo Co., Ltd. to prepare an in-line additive solution A.
(Preparation of dope solution A)
Cellulose ester (cellulose triacetate synthesized from linter cotton, Mn = 148000,
Mw = 310000, Mw / Mn = 2.1,
Acetyl group substitution degree 2.92) 100 parts by mass Trimethylolpropane tribenzoate 5.0 parts by mass Ethylphthalyl ethyl glycolate 5.5 parts by mass Methylene chloride 440 parts by mass Ethanol 40 parts by mass The solution was completely dissolved with stirring, and Azumi Filter Paper No. 24, and the dope liquid A was prepared.

  The dope solution A was filtered with Finemet NF manufactured by Nippon Seisen Co., Ltd. in the film production line. In-line additive solution line was filtered with Finemet NF manufactured by Nippon Seisen Co., Ltd. 100 parts by weight of the filtered dope liquid A is added in a ratio of 3 parts by weight of the filtered in-line additive liquid A, and mixed well with an in-line mixer (Toray static in-tube mixer Hi-Mixer, SWJ). A belt casting apparatus was used to uniformly cast the stainless steel band support at a temperature of 32 ° C. and a width of 1.8 m. With the stainless steel band support, the solvent was evaporated until the amount of residual solvent reached 100%, and then peeled off from the stainless steel band support. The peeled cellulose ester web was evaporated at 35 ° C., slit to 1.65 m width, and then stretched by 1.05 times in the TD direction (direction perpendicular to the film transport direction) with a tenter. Drying was performed at a drying temperature of ° C. At this time, the residual solvent amount when starting stretching with a tenter was 20%.

  Then, drying was completed while transporting the drying zone at 120 ° C and 110 ° C with a number of rolls, slitting to a width of 1.4m, knurling with a width of 1cm and an average height of 8µm was applied to both ends of the film, and initial winding The cellulose ester film 1 was obtained by winding it around a 6-inch inner diameter core with a tension of 220 N / m and a final tension of 110 N / m. The draw ratio in the MD direction (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 1.07. The average film thickness of the cellulose ester film 1 was 40 μm, and the winding number was 3000 m.

  Next, in the same manner as the cellulose ester film 1, a cellulose ester film 2 having an average film thickness of 60 μm and a cellulose ester film 3 having an average film thickness of 80 μm were prepared.

<Rubbing the film surface with an elastic body wetted with liquid>
Using the produced cellulose ester films 1 to 3, the film surface was rubbed with an elastic body wetted with a liquid according to the following specifications.

  Using the film transport apparatus shown in FIG. 1, one surface of the long film was rubbed with an elastic body 1 wetted with a liquid. The details of the used elastic body are as follows.

Material of elastic body: A 20 cm aluminum roller is coated with acrylonitrile-butadiene rubber with a thickness of 5 mm. Hardness of elastic body: Rubber hardness 30 (measured using durometer A type according to JIS-K-6253 method)
Elastic body size: Roll diameter 20cm
Friction coefficient change of elastic body: After the surface of the elastic body is thoroughly washed with petroleum benzine, a cloth soaked with 5 mass% of trichloroisocyanuric acid solution dissolved in acetic acid ethyl ester is brought into contact with the elastic body while rotating the elastic body. Then, a trichloroisocyanuric acid solution was applied to the elastic body surface. This elastic body was dried at room temperature as it was, and the surface was dried by volatilizing the solvent in about 0.5 hours. The friction coefficient of the elastic body was changed as shown in Table 1 by changing the concentration of the trichloroisocyanuric acid solution. The static friction coefficient was measured by the above method using a “Haydon surface property measuring instrument type 14” manufactured by Shinto Kagaku Co., Ltd.

Elastic drive direction and number of rotations: Rotate in the direction reverse to the film transport direction, rotation speed 10 rpm
Elastic body temperature: 30 ° C
The conveyance speed of the cellulose ester film was 15 m / min.

  The liquid used pure water. Further, the nozzle 8 is a 140 cm long rod-shaped nozzle installed in the film width direction, the tip opening has a clearance of 1 mm, and pure water is fed at the position of the nozzle 8 in FIG. Sprayed onto the film surface. The filter 10 was a commercial product having a hole diameter of 0.2 mm.

When air was supplied to the back surface of the film using the air nozzle 5, the supply air pressure was adjusted so that the film surface pressure to the elastic body was 3.0 × 10 ² Pa.

  The elastic body is cleaned by the method using the ultrasonic vibrator shown in FIG. 5A. Two ultrasonic vibrators (special models made by Nippon Alex Co., Ltd.) are arranged in the film width direction and four in the film transport direction. Installed side by side. The size of one vibrator was 50 cm in the width direction of the film and 30 cm in the transport direction, and 100 KHz ultrasonic waves were output at a power of 1000 W.

  In addition, one edge position controller (EPC) is installed in the film transport path at the position of 10m upstream and 10m downstream of the device to control the position of the long film rubbed on the elastic body 1. did.

  Using the produced cellulose ester films 1 to 3, the friction coefficient of the elastic body 1, whether or not the liquid 4 (pure water) is supplied to the film surface by the nozzle 8, and the length due to the position change from the elastic body 1 to the air nozzle 6 Table 1 shows how long the surface to be processed of the film is wet, whether air nozzle 5 blows air onto the back of the film, the temperature of pure water 4 (temperature adjustment by a cooler or heater), and whether EPC is installed. Treated cellulose ester films C-1 to C-25 were prepared.

(Preparation of optical film with antireflection layer)
Using the treated cellulose ester films C-1 to C-25, optical films with antireflection layers were prepared by the following procedures.

  The refractive index of each layer constituting the antireflection layer was measured by the following method.

(Refractive index)
The refractive index of each refractive index layer was determined from the measurement result of the spectral reflectance of a spectrophotometer for a sample in which each layer was coated on the hard coat film prepared below. The spectrophotometer uses U-4000 type (manufactured by Hitachi, Ltd.), and after roughening the back side of the measurement side of the sample, light absorption treatment is performed with black spray to prevent reflection of light on the back side. The reflectance in the visible light region (400 nm to 700 nm) was measured under the condition of regular reflection at 5 degrees.

(Particle size of metal oxide fine particles)
As for the particle diameter of the metal oxide fine particles used, 100 fine particles were observed with an electron microscope (SEM), the diameter of a circle circumscribing each fine particle was taken as the particle diameter, and the average value was taken as the particle diameter.

<< Formation of hard coat layer >>
On the treated cellulose ester films C-1 to C-25, the following hard coat layer coating solution is filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a hard coat layer coating solution. After coating with a coater and drying at 90 ° C., the coating layer is cured with an ultraviolet lamp using an ultraviolet lamp with an illuminance of 100 mW / cm ² and an irradiation dose of 0.1 J / cm ² . A hard coat layer was formed to produce a hard coat film.

(Hard coat layer coating solution)
The following materials were stirred and mixed to obtain a hard coat layer coating solution.

Acrylic monomer; KAYARAD DPHA
(Dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku) 220 parts by mass Irgacure 184 (manufactured by Ciba Specialty Chemicals) 20 parts by mass Propylene glycol monomethyl ether 110 parts by mass Ethyl acetate 110 parts by mass <Preparation of optical film with antireflection layer >
On the hard coat film prepared above, an antireflection layer was applied in the order of a high refractive index layer and then a low refractive index layer as described below, and optical films 1 to 25 with an antireflection layer were produced.

(Antireflection layer formation: high refractive index layer)
On the hard coat film, the following high refractive index layer coating composition was applied by an extrusion coater, dried at 80 ° C. for 1 minute, then cured by irradiating with ultraviolet rays of 0.1 J / cm ² and further at 100 ° C. for 1 minute. A high refractive index layer was provided so as to have a thickness of 78 nm by thermosetting.

  The refractive index of this high refractive index layer was 1.62.

(High refractive index layer coating composition)
Isopropyl alcohol solution of metal oxide fine particles (solid content 20%, ITO particles, particle size 5 nm) 55 parts by mass Metal compound: Ti (OBu) ₄ (tetra-n-butoxytitanium) 1.3 parts by mass Ionizing radiation curable resin : Dipentaerythritol hexaacrylate 3.2 parts by mass Photopolymerization initiator: Irgacure 184
(Ciba Specialty Chemicals Co., Ltd.) 0.8 parts by mass 10% propylene glycol monomethyl ether solution of linear dimethyl silicone-EO block copolymer (FZ-2207, manufactured by Nippon Unicar Co., Ltd.) 1.5 parts by mass Propylene glycol monomethyl Ether 120 parts by mass Isopropyl alcohol 240 parts by mass Methyl ethyl ketone 40 parts by mass (formation of antireflection layer: low refractive index layer)
The following low refractive index layer coating composition is applied onto the high refractive index layer by an extrusion coater, dried at 100 ° C. for 1 minute, and then cured by irradiating with an ultraviolet lamp at 0.1 J / cm ^2. The film was wound around a heat resistant plastic core at a winding length of 4000 m, and then heat-treated at 80 ° C. for 3 days to produce optical films 1 to 25 with an antireflection layer.

  The low refractive index layer had a thickness of 95 nm and a refractive index of 1.37.

(Preparation of low refractive index layer coating composition)
<Preparation of tetraethoxysilane hydrolyzate A>
Hydrolyzate A was prepared by mixing 289 g of tetraethoxysilane and 553 g of ethanol, adding 157 g of 0.15% aqueous acetic acid solution thereto, and stirring in a water bath at 25 ° C. for 30 hours.

Tetraethoxysilane hydrolyzate A 110 parts by mass Hollow silica-based fine particle (P-2 below) dispersion 30 parts by mass KBM503 (silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.) 4 parts by mass Linear dimethyl silicone-EO block copolymer (FZ-2207, manufactured by Nippon Unicar Co., Ltd.) 10% propylene glycol monomethyl ether solution 3 parts by mass Propylene glycol monomethyl ether 400 parts by mass Isopropyl alcohol 400 parts by mass <Preparation of dispersion of hollow silica-based fine particles (P-2)>
A mixture of 100 g of silica sol having an average particle diameter of 5 nm and a SiO ₂ concentration of 20% by mass and 1900 g of pure water was heated to 80 ° C. The pH of this reaction mother liquor was 10.5, and 9000 g of 0.98 mass% sodium silicate aqueous solution as SiO ₂ and 9000 g of 1.02 mass% sodium aluminate aqueous solution as Al ₂ O ₃ were simultaneously added to the mother liquor. did. Meanwhile, the temperature of the reaction solution was kept at 80 ° C. The pH of the reaction solution rose to 12.5 immediately after the addition, and hardly changed thereafter. After completion of the addition, the reaction solution was cooled to room temperature and washed with an ultrafiltration membrane to prepare a SiO ₂ .Al ₂ O ₃ core particle dispersion with a solid content concentration of 20% by mass (step (a)).

1700 g of pure water is added to 500 g of this core particle dispersion and heated to 98 ° C., and while maintaining this temperature, a silicic acid solution (SiO ₂₎ obtained by dealkalizing a sodium silicate aqueous solution with a cation exchange resin. A dispersion of core particles in which a first silica coating layer was formed by adding 3000 g (concentration: 3.5% by mass) was obtained (step (b)).

Next, 1125 g of pure water is added to 500 g of the core particle dispersion liquid that has been washed with an ultrafiltration membrane to form a first silica coating layer having a solid content concentration of 13% by mass, and concentrated hydrochloric acid (35.5%) is further added dropwise. The pH was adjusted to 1.0 and dealumination was performed. Next, the aluminum salt dissolved in the ultrafiltration membrane was separated while adding 10 L of hydrochloric acid aqueous solution of pH 3 and 5 L of pure water, and SiO ₂ · Al from which some of the constituent components of the core particles forming the first silica coating layer were removed. A dispersion of ₂ O ₃ porous particles was prepared (step (c)).

A mixture of 1500 g of the above porous particle dispersion, 500 g of pure water, 1,750 g of ethanol, and 626 g of 28% ammonia water is heated to 35 ° C., and then 104 g of ethyl silicate (SiO ₂ 28 mass%) is added. The surface of the porous particles on which the first silica coating layer was formed was coated with a hydrolyzed polycondensate of ethyl silicate to form a second silica coating layer. Subsequently, a dispersion of hollow silica-based fine particles (P-2) having a solid content concentration of 20% by mass in which the solvent was replaced with ethanol using an ultrafiltration membrane was prepared.

The thickness of the first silica coating layer of the hollow silica-based fine particles was 3 nm, the average particle size was 47 nm, MOx / SiO ₂ (molar ratio) was 0.0017, and the refractive index was 1.28. Here, the average particle diameter was measured by a dynamic light scattering method.

<Evaluation>
The following evaluation was implemented using the obtained optical films 1-25 with an antireflection layer.

(Vertical stripe evaluation of antireflection layer)
Anti-reflection layer optical film with 3000m respectively ten coated, 1 m ² samples in each winding, blackened the sampled base antireflective layer back surface of the black spray, a fluorescence lamp antireflection layer surface 3 Wavelength Visual evaluation was performed to evaluate the number of vertical stripes.

(10 pieces x 1m ² x 10 places = 100m ² evaluation)
The vertical stripe is a straight stripe generated in the film conveyance direction, and the stripe portion looks different from the other portions in the color of the reflected light.

◎: No vertical streaking ○: 1 / 100m ² Vertical streak △: 2-10 / 100m ² Vertical streaking ×: More than 10 / 100m ² (Horizontal evaluation of antireflection layer)
Anti-reflection layer optical film with 3000m respectively ten coated, 1 m ² samples in each winding, blackened the sampled base antireflective layer back surface of the black spray, a fluorescence lamp antireflection layer surface 3 Wavelength Visual evaluation was performed to evaluate the occurrence of horizontal rows.

(10 pieces x 1m ² x 10 places = 100m ² evaluation)
The horizontal stage occurs in the width direction of the film, and the color of the reflected light varies stepwise. The stepped pitch is about 1-5 mm.

◎: No occurrence ○: in 100m ^2, 1m ² following the widthwise corrugation occurred △: in 100m ^2, widthwise corrugation occurrence × to 10m ² following more than a 1: in 100m ^2, widthwise corrugation occurs 20m ² following more than 10 ( Tail)
Apply 10 optical films 4000m each with anti-reflective layer, sample 1m ^{2 in} each roll, paint the back of sampled anti-reflective layer black with black spray, and apply anti-reflective layer surface with 3 wavelength fluorescent lamp Visual evaluation was performed to evaluate the occurrence of tailing.

(10 pieces x 1m ² x 10 places = 100m ² evaluation)
The tailing is a failure in which the coating solution of the antireflection layer is repelled.

  In many cases, the length of the repelling film transport direction is 10 μm to 100 μm.

A: 0 / 100m ²
○: 1 to 5 pieces / 100 m ²
Δ: 6-20 pieces / 100 m ²
×: More than 20 pieces / 100 m ² (foreign matter failure)
By visual inspection of the coating film, the number of protrusions and / or pit-like failures that appeared to have a diameter of less than 100 to 150 μm or a diameter of 150 μm or more was counted per 1 m ² .

  A foreign matter failure with a diameter of 100 μm means that the rate of change in the thickness of the coating surface with respect to the reference surface of the coating is 2 μm (change in thickness of the coating) / 100 μm (distance on the reference surface) or more and the thickness of the coating is 0.5 μm. This is a failure having a diameter of 100 μm when the range of the protrusion-like failure and / or the depression-like portion changed as described above is viewed as a substantially circular shape, which is a foreign matter failure having a size of 100 μm. Similarly, the failure having the diameter of 150 μm is regarded as a foreign matter failure having a size of 150 μm. In the actual foreign matter failure inspection, a sample of the foreign matter failure having the size of 100 μm and the foreign matter failure having the size of 150 μm is prepared, and a sample of the foreign matter failure having the size of 100 μm and the sample of the foreign matter failure having the size of 150 μm are prepared. Foreign matter failures having an intermediate size were counted as the number of foreign matters having a diameter of 100 to 150 μm. Similarly, for a sample of foreign matter failure having a size of 150 μm, a foreign matter failure having a size larger than 150 μm was counted as a foreign matter having a size of 150 μm or more.

  Further, the state of the cross-section of the protrusion failure or the depression failure due to the foreign matter failure can be observed with an optical interference type surface roughness meter or the like.

  The above counted number of foreign matters was evaluated based on the following.

A: Foreign matter of 100 μm or more is not recognized. ○: Foreign matter of 100 to less than 150 μm is slightly observed. Δ: Foreign matter of less than 100 to 150 μm is observed. ×: Foreign matter of less than 100 to 150 μm is recognized. Foreign matter is also observed (occurrence of wrinkles)
Each of the treated cellulose ester films was visually observed during conveyance and evaluated for the occurrence of wrinkles according to the following criteria.

◎: No wrinkle is generated in all 10 ◯: Less than 1 to 3, wrinkles are slightly observed Δ: Within 1 to 3 wrinkles are clearly observed ×: 4 or more, wrinkles The above evaluation results are shown in Table 1 below.

  From Table 1, optical films 2 to 6 and 8 to 22 with an antireflection layer using the treated cellulose ester films C-2 to C-6 and C-8 to C-22 of the present invention are vertical line failure and horizontal line failure. It can be seen that tailing, foreign object failure, and wrinkle are improved with respect to the comparative example. Moreover, it turned out that the said improvement effect becomes still higher by each setting to the preferable range of the processing method shown by the structures 2-9.

Example 2
A polarizing plate and a liquid crystal display device were prepared using the optical films 1 to 25 with an antireflection layer prepared in Example 1.

<Preparation of polarizing plate>
A polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times). This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. This was washed with water and dried to obtain a polarizing film.

  Next, a polarizing plate was prepared by laminating a cellulose ester film as a polarizing film and the antireflection layer-coated optical films 1 to 25 prepared in Example 1 and the back side polarizing plate protective film according to the following steps 1 to 5. As the polarizing plate protective film on the back side, a cellulose ester film having a phase difference (Konica Minolta Tack KC8UCR-5: manufactured by Konica Minolta Opto Co., Ltd.) was used as a polarizing plate.

  Step 1: It was immersed in a 2 mol / L sodium hydroxide solution at 60 ° C. for 90 seconds, then washed with water and dried to obtain an optical film with an antireflection layer in which the side to be bonded to the polarizer was saponified.

  Step 2: The polarizing film was immersed in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds.

  Step 3: Excess adhesive adhered to the polarizing film in Step 2 was lightly wiped off, and this was placed on the optical film with an antireflection layer treated in Step 1 and laminated.

Step 4: The prepared optical film with an antireflection layer laminated in Step 3, the polarizing film, and the cellulose ester film on the back side were bonded at a pressure of 20 to 30 N / cm ² and a conveyance speed of about 2 m / min.

  Step 5: A sample obtained by bonding the polarizing film prepared in Step 4 to the optical film with the antireflection layer and the back-side cellulose ester film in a dryer at 80 ° C. was dried for 2 minutes to prepare a polarizing plate. Polarizing plates 1 to 25 were prepared using the optical films 1 to 25 with an antireflection layer, respectively.

<Production of liquid crystal display device>
A liquid crystal panel for viewing angle measurement was produced as follows, and the characteristics as a liquid crystal display device were evaluated.

  The polarizing plates on both sides of the 15-inch display VL-150SD manufactured by Fujitsu were previously peeled off, and the above-prepared polarizing plates 1 to 25 were each bonded to the glass surface of the liquid crystal cell.

  At that time, the direction of bonding of the polarizing plates was performed such that the absorption axis was in the same direction as that of the polarizing plates bonded in advance, and the liquid crystal display devices 1 to 25 were produced.

  The following evaluation was performed using the liquid crystal display devices 1 to 25 obtained as described above.

<Evaluation>
<Evaluation of visibility>
About each produced said liquid crystal display device, after leaving for 100 hours on 60 degreeC and 90% RH conditions, it returned to 23 degreeC and 55% RH. As a result, when the surface of the display device was observed, all of the optical films 2 to 6 and 8 to 22 with the antireflection layer of the present invention were evaluated as ◯ to ◎ and excellent in flatness, The comparative display device was evaluated as x to Δ, and fine wavy irregularities were observed, and the eyes were easily tired when viewed for a long time.

A: No wavy unevenness is observed on the surface. O: A slight wavy unevenness is observed on the surface. Δ: A slight wavy unevenness is slightly observed on the surface.

  INDUSTRIAL APPLICABILITY According to the present invention, there is provided an optical film processing method and an optical film in which application failures such as horizontal unevenness, coating stripes, and tailing that are likely to occur when a functional layer such as an antireflection layer is applied on a long film are improved. The present invention is characterized in that it is possible to provide a processing apparatus, and in particular, it is possible to improve lateral unevenness.

  Conventionally, it has been known to remove dust on the film surface in order to improve point defects and streaks caused by foreign matters, such as JP-A-8-89920, JP-A-2001-38306, and JP-A-2003. In US Pat. No. 8,255,136, a wet type dust removal process having a form close to the present invention is known.

  However, these dust removal treatments can improve point defects and streaks due to foreign matter to some extent, but are not sufficient, and the horizontal unevenness cannot be improved. The present invention can improve lateral unevenness at the same time as a coating failure due to a foreign matter.

Claims (21)

In the optical film processing method of removing the liquid on the surface of the long film after rubbing the long film being transported with the elastic body wet with the liquid, the static friction coefficient of the elastic body surface before wetting with the liquid is 0 A method for treating an optical film, wherein the method is 2 or more and 0.9 or less.   The method for treating an optical film according to claim 1, wherein the elastic body is a surface-modified rubber.   The optical film processing method according to claim 1, further comprising means for detecting a width end position of the long film and adjusting a transport position.   The method of processing an optical film according to claim 1, wherein the temperature of the liquid is 30 ° C or higher and 100 ° C or lower, and the temperature of the elastic body is 30 ° C or higher and 100 ° C or lower.   2. The method of processing an optical film according to claim 1, wherein the elastic body is rubbed while pressurizing the back surface of the long film.   2. The method for processing an optical film according to claim 1, wherein the surface to be processed of the long film is preliminarily coated with a liquid before rubbing with an elastic body wetted with the liquid.   The method for processing an optical film according to claim 6, wherein the surface to be processed is wetted by means for supplying a liquid to the surface to be processed of the long film.   The method for processing an optical film according to claim 6, further comprising means for supplying a liquid between the long film and the elastic body.   2. The method for processing an optical film according to claim 1, wherein a time during which the surface to be processed of the long film is wet with a liquid is 2 seconds or more and 60 seconds or less.   The method for processing an optical film according to claim 1, wherein the film thickness of the long film is 30 µm or more and 70 µm or less. In an optical film processing apparatus comprising: an elastic body rubbing means for rubbing a long film being conveyed with an elastic body wetted with a liquid; and a liquid removing means for removing the liquid on the surface of the long film after rubbing. An apparatus for processing an optical film, wherein a coefficient of static friction of the surface of the elastic body before wetting with the liquid is 0.2 or more and 0.9 or less.   12. The apparatus for processing an optical film according to claim 11, further comprising means for detecting a width end position of the long film and adjusting a transport position.   The liquid temperature adjusting means for adjusting the liquid temperature to 30 to 100 ° C. and the elastic body temperature adjusting means for adjusting the temperature of the elastic body to 30 to 100 ° C. The processing apparatus of the optical film of the range 11th term.   12. The apparatus for processing an optical film according to claim 11, further comprising means for pressurizing a back surface of the long film.   12. The optical film processing apparatus according to claim 11, further comprising a film wetting unit that wets a surface to be processed of the long film with a liquid before the elastic body rubbing unit.   16. The optical film processing apparatus according to claim 15, wherein the film wetting means is means for supplying a liquid to a surface to be processed of the long film.   16. The optical film processing apparatus according to claim 15, wherein the film wetting means is means for supplying a liquid between the long film and the elastic body.   12. The apparatus for processing an optical film according to claim 11, wherein the processing time from the start of wetting by the film wetting means to the end of removal by the liquid removing means is 2 seconds or more and 60 seconds or less.   A method for producing an optical film, comprising: applying a functional layer to a surface to be treated of the long film after being treated in the method for treating an optical film according to claim 1.   The method for producing an optical film according to claim 19, wherein the functional layer is an antireflection layer or an actinic radiation curable resin layer.   21. The method for producing an optical film according to claim 20, wherein the long film is a cellulose ester film, and the liquid is water.