JP2006154709A - Optical film, polarizing plate, display device and manufacturing method of optical film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film which is capable of reducing defects due to repellence and has satisfactory quality and yield. <P>SOLUTION: The optical film is made by applying coating liquid comprising at least one kind of organic solvent, at least one kind of active radiation curable resin and/or at least one kind of organic silyl compound presented by the following general formula (a) or its hydrolysate and its partial condensate on a film substrate having a thickness of 30 to 200μm, wherein point defects of ≥100μm in a coating film formed on the optical film is ≤2 pieces/film 1 m<SP>2</SP>. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical film, a polarizing plate using the same, and a display device using these. More specifically, in an optical film obtained by coating an optical functional layer on a film substrate, an optical film with few point defects, a method for producing the optical film, a polarizing plate using the optical film, and a display using the same Relates to the device.

  Optical functional films are generally applied to image display devices such as cathode ray tube display devices (CRT), plasma displays (PDP), electroluminescence displays (ELD), and liquid crystal display devices (LCD). . As such an optical film, an antireflection film, an antiglare film, an optical compensation film, a surface protective film, a polarizing plate and the like are known.

  Since these optical films are used in an image display device that is directly observed visually, extremely strict quality is required against point-like defects (point defects) such as foreign matter and repellency. In addition, since a large-area film is used due to an increase in the screen size of the display, an optical film having a large area and no point defects is required. For this reason, when there are many point defects, it will become a big problem in the yield and productivity of an optical film.

Moreover, as an optical function layer in an optical film, it is often provided by the coating of the solution on a base film, especially the coating of the solution containing an organic solvent. In an optical film provided with an optical functional layer by such coating, an antireflection film, an antiglare film, an optical compensation film, etc. have a large change in characteristics due to a change in the film thickness of the coating film, even with a small film thickness difference. As defects, they are often conspicuous, and point defects are easily manifested.
For this reason, a film with few point defects and a manufacturing method thereof are desired, and dust removal of the film before coating, methods for enhancing the cleanliness of the coating process (Patent Documents 1 and 2), and filtration of the coating liquid A method (Patent Document 3) and the like are known.
JP 2001-343505 A JP 2002-40245 A JP 2000-304926 A

Among the above point defects, there are few effective countermeasures for point defects caused by the coating solution, particularly repelling defects, which has been a big problem.
An object of the present invention is to provide an optical film with reduced point defects and good quality and yield.
Another object of the present invention is to provide a method for producing an optical film with reduced point defects.

As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that raw material components used in the coating liquid, particularly actinic radiation curable resins, silane coupling agents, against repellency defects that do not have nuclei due to the coating liquid. It has been found that polydimethylsiloxane or the like may be included as a component (repellent component) that generates a small amount of a repelling defect. In addition, fluorine and silicone surfactants are often added to the coating solution in order to suppress drying unevenness, but it is understood that repellent components may be contained in this surfactant. I came.
Then, the present inventors have found that an optical film in which the repelling component can be easily removed and the number of repelling defects is reduced can be achieved by filtering the coating solution with a polypropylene filter.
That is, the objective of this invention is achieved by the following optical film and the manufacturing method of an optical film.

1. An optical film formed by applying a coating solution containing a solvent and an actinic radiation curable resin on a film substrate to form a coating layer, and the point defect of 100 μm or more in the coating layer is ² per 1 m ^{2 of} film. An optical film characterized by having no more than one piece.
2. An optical film obtained by coating a coating liquid containing an organic silyl compound represented by the following general formula a, a hydrolyzate thereof or a partial condensate thereof on a film substrate to form a coating layer, 2. The optical film as described in 1 above, wherein the number of point defects of 100 μm or more in the coating layer is 2 or less per 1 m ^{2 of} film.
Formula a
(R) mSi (X) n
(R represents a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms or a substituted or unsubstituted aryl group. X represents —OH, a halogen atom, —OR ¹ group, or OCOR ¹ group. R ¹ represents Represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, m + n is 4, and m and n are each an integer of 0 or more.)
3. 3. The optical film as described in 1 or 2 above, wherein the point defect of 100 μm or more is a point defect having no core foreign matter.
4). 4. The optical film as described in any one of 1 to 3 above, wherein the coating solution is filtered with a filter having a polyolefin filter material.
5. 5. The optical film as described in 4 above, wherein the filter is a depth type filter.
6). 6. The optical film as described in any one of 1 or 5 above, which contains at least one of a fluorine-based compound and a silicone-based compound having a surface-active effect on the coating solution.
7). 7. The optical film as described in 6 above, wherein at least one of the fluorine compound and the silicone compound is present in the point defect portion of 100 μm or more at a concentration of 10 times or less as compared with the normal part.
8). 8. The optical film as described in any one of 1 to 7 above, wherein the solvent contains at least one of ketones, alcohols, aromatic hydrocarbons, and esters having a boiling point of 100 ° C. or higher.
9. 9. The optical film as described in any one of 1 to 8 above, wherein the coating liquid contains translucent particles.
10. 10. The optical film as described in 9 above, wherein the coating layer is an antiglare property-imparting layer.
11. 11. The optical film as described in any one of 1 to 10 above, wherein a low refractive index layer having a refractive index of 1.31 to 1.45 is provided on the coating layer.
12 9. The optical film as described in any one of 1 to 8 above, wherein a discotic compound is contained in the coating solution.
13. 13. A polarizing plate, wherein the protective film on at least one side of the polarizing film is the optical film described in any one of 1 to 12 above.
14 13. A display device comprising the optical film according to any one of 1 to 12 or the polarizing plate according to 13 above.
15. A step of filtering a coating solution containing a solvent and an actinic radiation curable resin with a depth type filter having a polyolefin filter material, and applying the filtered coating solution on a film substrate The manufacturing method of the optical film characterized by including the process to form.
16. A step of filtering a coating solution containing an organic silyl compound represented by the following general formula a, a hydrolyzate thereof or a partial condensate thereof with a depth type filter having a polyolefin filter material, and the filtration treatment 16. The method for producing an optical film as described in 15 above, which comprises a step of applying a coating solution on a film substrate to form a coating layer.
Formula a
(R) mSi (X) n
(X represents —OH, a halogen atom, —OR ¹ group, or OCOR ¹ group. R ¹ represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms. R represents a substituted group having 1 to 30 carbon atoms. Or an unsubstituted alkyl group or an aryl group, m + n is 4, and m and n are each an integer of 0 or more.)
17. 16. The method for producing an optical film as described in 15 above, wherein a coating step is performed subsequent to the filtration treatment step.
18. 16. The method for producing an optical film as described in 15 above, further comprising a step of adding an additive component to the filtered coating solution between the filtering step and the coating step.
19. Between the filtration process and the coating process, a step of adding an additive component to the filtered coating liquid, and a coating liquid to which the additive component is added, a depth type having a polyolefin filter medium -The manufacturing method of the optical film of said 15 characterized by including the process of filtering with a filter.
20. A coating solution containing a solvent and an actinic radiation curable resin and / or an organic silyl compound represented by the following general formula a, a hydrolyzate thereof or a partial condensate thereof is applied onto a film substrate to form a coating layer. A method for producing an optical film, comprising the step of removing from the coating solution a component that generates a point defect that does not have a foreign substance that is a core of 100 μm or more in the coating layer. .
Formula a
(R) mSi (X) n
(X represents —OH, a halogen atom, —OR ¹ group, or OCOR ¹ group. R ¹ represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms. R represents a substituted group having 1 to 30 carbon atoms. Or an unsubstituted alkyl group or an aryl group, m + n is 4, and m and n are each an integer of 0 or more.)
21. 15 to 20 above, wherein the concentration of one of the fluorine-based compound and the silicone-based compound having a surfactant activity is 100 ppm or more and the concentration in the other coating solution is 1 ppm or less. The manufacturing method of the optical film in any one.

  According to the present invention, by removing the repellent component in the coating solution, it is possible to provide an optical film with good quality and high yield, in which point defects such as repelling defects are reduced. Moreover, according to this invention, the manufacturing method of the optical film with which point defects, such as a flip defect, were reduced can be provided.

  Hereinafter, embodiments of the optical film according to the present invention will be described. In the present specification, the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more and (numerical value 2) or less”.

  The optical film in the present invention is used for an antireflection film, an antiglare film, an antiglare antireflection film, a light diffusion film, an optical compensation film, a surface protective film, and the like. In such a film, a method is generally known in which a functional layer is provided by coating on a base film, and functions such as antireflection, antiglare property, light scattering property, surface hardness, and optical compensation property are imparted. In these functional layers, point defects are often easily seen visually due to changes in the film thickness and changes in the density of the contained particles due to changes in optical properties. In addition, since these films are used by an image display device, they are directly observed through transmission and reflection, so that extremely strict quality is required against point defects. The effects of the present invention can be seen against the above problems. In particular, the effect of the present invention is great for antireflection films, antiglare films, antiglare antireflection films, light diffusion films, optical compensation films, and the like.

The point defect in the optical film of the present invention means a film having a thickness of 100 μm or more which can be visually observed on the coating layer. Such a point defect is confirmed by visual transmission or reflection observation. As the transmission or reflection observation method, there are observation methods assumed for various image display devices, such as observation under various light sources such as fluorescent lamp, tungsten light, artificial solar lamp, transmission observation with strong light, polarizing plate crossing, etc. It is performed according to the usage of the optical film such as transmission observation under Nicol. The size of 100 μm indicates the size observed visually. Such point defects usually need to be 2 or less per 1 m ^{2 of the} coated film when provided as an optical film. More preferably, it is 1 or less per 1 m ² , more preferably 0.5 or less per 1 m ² , and particularly preferably 0.1 or less per 1 m ² .
Such point defects can be roughly classified into point defects having a foreign substance as a nucleus (foreign substance defect) and point defects having no foreign substance as a nucleus by observation with an eye or an optical microscope. Here, the foreign material as a core is a foreign material such as dust from the process, foreign matter due to scratches on the film to be applied, insoluble matter in the raw material used for the coating liquid, impurities, variability in the coating liquid, A foreign substance or the like in which a component such as a reaction product is solid, and a point defect having a foreign substance serving as a nucleus is a point defect in which a solid substance having a component and composition ratio of a surrounding coating film is observed. Such a foreign substance serving as a nucleus can be confirmed by surface and cross-sectional observation using an optical microscope, a scanning electron microscope, or the like.

  On the other hand, point defects that do not have core foreign matter appear as defects by visual inspection of the film, but when the defect is observed from the surface or cross section with an optical microscope, electron microscope, etc., the core foreign matter is not seen. It is a drawback. Examples of such point defects include repelling defects and missing defects, and particle aggregation defects when particles are included as a component. As a result of our investigation on the causes of these defects, repellency defects are caused by repelling components and fine bubbles in the coating solution, and missing defects are caused by repelling components and bubbles in the coating solution. And those caused by dirt on the base material, aggregation defects include those caused by poorly dispersed particles, and those caused by the formation of particle aggregates in liquid, the main causes of occurrence are It has been found that there are many causes of defects in the coating solution. The present invention shows an improvement effect for the point defect caused by the coating liquid and having no foreign substance as a core. Among them, the effect is particularly great for those caused by repelling components in the liquid, such as repelling defects and missing defects.

The repelling defect has a circular shape, a ring shape, or the like as a visual form, and changes in the shape such as a trailing shape or a linear shape due to the direction of application. In addition, when the cross section of the defective part is observed in detail, the surface shape measurement of the defective part, etc., the circular part, ring part, etc. are seen to be thinner than the normal film thickness. In some cases, a portion that is slightly thicker around the center portion or at the center portion is also observed. When the coating film contains particles, the particles in the repelling part tend to decrease, but in some cases, the particles are concentrated in the central part, and in some cases, the sparse and dense parts of the particles are seen in the ring shape. is there. When observing the defect part with an optical microscope or scanning microscope, the nucleus of the foreign matter is not visible and other abnormal components are often not found. In addition, repellent components such as silicone and fluorine may be observed.
In most cases, the concentration of repellent components such as silicone and fluorine observed at that time exceeds at least 10 times the concentration of the normal part. Therefore, the concentration of the repellent component in the point defect portion is preferably 10 times or less, more preferably 5 times or less, and most preferably 2 times or less that of the normal portion. If it is 10 times or less, the size or contrast as a point defect becomes small, and it becomes difficult to be detected by visual inspection.
In addition, as a defect other than the repelling defect, the missing defect has a characteristic that the coating thickness of the defect portion is extremely thin or there is no coating layer, and the above repelling component may be detected. In addition, in the aggregation defect, characteristics such as a high density of particles in the center and the appearance of an aggregate with a number of particles attached are observed.

As a result of our investigation, active radiation curable resins and / or organic silyl compounds generally contained in optical films may contain substances that cause repellency defects in these commercially available raw materials. I understand. The causative substance may be contained, for example, as contamination from the raw material synthesis process and purification process, contamination from a transport can, or as a by-product during synthesis.
In addition, as a result of analysis, various hydrophobic and oleophobic substances such as silicone compounds, fluorinated alkyl compounds, long-chain alkyl compounds, etc. can be considered as the causative substances of repellency defects. Has been found to contain a trace amount of a silicone compound such as polydimethylsiloxane which is considered to be a contamination in the raw material or a by-product.
Furthermore, due to lack of cleaning at the time of switching from the previous process in liquid preparation or liquid feeding, contamination of the causative substance of the repellency defect is conceivable in each process until just before coating.

According to the study by the present inventors, it has been found that, as a means for reducing point defects that do not have a foreign substance as a core, especially repelling defects, it is effective to perform a filtration treatment of the coating liquid during the production of an optical film. It was.
In the present invention, it is considered that the effect of filtration with a polyolefin filter of the coating solution is due to the removal of the repelling component so as not to cause a point defect of 100 μm or more that does not have a foreign substance as a core. Regarding the removal effect of the repellent component, specifically, it has been confirmed that the repellent silicone may be removed by filtration through a polyolefin filter of the coating solution. Regarding the removal effect of the repellency component by the filter, the mechanism of adsorption of the repellency component by the polyolefin of the filter is estimated. However, in the present invention, it is only necessary to be able to reduce point defects of 100 μm or more that do not have a core foreign matter regardless of the mechanism.

  When the repellency component is contained in the coating solution, repellency often occurs at an amount of 10 ppm or less, although it varies depending on the type of solvent. For this reason, the amount of the repellent component in the coating solution is desirably 10 ppm or less, more desirably 1 ppm or less, still more desirably 500 ppb or less, and particularly desirably 100 ppb or less. Although the content of repellent components is very small and may be difficult to detect depending on the composition of the coating solution, its abundance should be confirmed by various analytical methods such as atomic absorption, NMR, gas chromatography, and liquid chromatography. You can also.

  In the filtration treatment, using a filter using polyolefin as a filter medium is particularly effective for reducing the repelling defect. This is presumably because the filter material of the polyolefin filter has an action of adsorbing hydrophobic and oleophobic components such as silicone as a repellent component. Of these polyolefin filter media, polypropylene filter media are particularly preferred.

  The filter used for the filtration treatment is usually marketed as a cartridge type filter. As the filter material of the filter, it is filtered in the thickness direction with a sheet type filter material of the surface type that filters on the surface and a thick filter material made by knitting fibers and heat-sealing. Although there is a depth type filter medium, in the present invention, it is preferable to use a depth type filter having a large surface area of the filter medium. Of the depth type filters, filters provided as a type capable of high-precision filtration by each filter manufacturer are particularly preferable.

  Specific examples of the filter made of polyolefin as a filter material are those manufactured by Pall, HDCII, Profile, Profile II, Ultipleat Profile, Profile II Plus, Petrosope, etc. , Porous Fine, Superwind Filter, Stem Filter, GF Filter, etc., Loki Techno, SL Filter, Micro Syria Filter, Dia II Type Filter, Micro Pure Filter, Fuji Film, Astropore PPE, etc. It is done. Of these, the profile type II, the BM filter, and the like are preferable as the filters of the depth type and having high accuracy of filtration.

The filter pore diameters of these filters are generally indicated by absolute filtration accuracy when they have nominal filtration accuracy or high filtration accuracy, but those of about 0.5 μm to 200 μm are known. A smaller filtration pore diameter is preferable because the surface area of the filter medium increases. Specifically, the filtration pore diameter is preferably 10 μm or less, more preferably 1 μm or less.
However, in the case of a coating solution containing particles, it is necessary to select an optimum pore size in accordance with the permeability of the particles. In the case of a coating solution containing particles, the filter pore size is approximately 1.5 times to 10 times the filtration accuracy of the largest average particle size of the particle components to be passed in the coating solution. Those having are preferred. Particularly preferably, it is about 2 to 7 times.

Further, in the filtration treatment in the present invention, the range of the liquid treatment amount with respect to the filter area can be set from the viewpoints of trapping ability of the filter repellent component, filter life when used for a long time, and the like. When a normal filter is used, a filter cartridge with a length of 10 inches is often used. Therefore, when the liquid processing amount per 10 inch filter is defined, the processing amount of the coating liquid per 10 inch filter is as follows: A range of about 5 kg to 10,000 kg is preferable. Particularly preferably, it is 10 kg to 6000 kg, more preferably 20 kg to 4000 kg.
The flow rate for the filter during the filtration treatment is preferably 0.3 kg / min to 10 kg / min per 10 inch filter, and particularly preferably 0.5 kg / min to 7 kg / min. With respect to the flow rate per filter, the flow rate can be adjusted by a method of arranging the filters in parallel or making the filter into a cartridge of 20 inches or 30 inches.

In the filtration treatment, it is also preferable to increase the number of times the coating solution passes per filter. A particularly preferred number of passes is in the range of 1 pass to 100 passes. The passing method is preferable because it is possible to carry out circulation type filtration with a pump from a tank and return it to the original tank with a relatively simple structure, and it can also be used as a liquid circulation method during coating. In order to ensure that the coating liquid passes through the filter, it is also preferable to use a method of filtering while transferring the liquid alternately in two tanks. Also preferred is a method of connecting the filters in series to increase the number of times the liquid passes through the filter.
In addition, in the case of filtration treatment, replacing the filter with a new one in the middle of the filtration treatment is also a preferable method from the viewpoint of the amount of repelling component adsorbed on the filter and the filter life.

Further, the coating liquid may be filtered by any method as long as the coating liquid is filtered before coating. FIG. 1 shows an example of a process until a coating liquid is specifically prepared and applied. In the method shown in FIG.
(A) A preparation process in which a solvent and raw materials to be added are put into a tank, and dissolved and dispersed by mixing, stirring, and dispersing operations;
(B) A filtration treatment step for filtering the liquid prepared in (a),
(C) The coating liquid is sent to the coating part (coating coater) and applied in the order of the coating process. As described above, since the treatment conditions of the liquid can be made constant in each step by performing the filtration treatment of the coating liquid in advance, there is an advantage that the liquid from which the repellent component is removed can be supplied under the constant conditions.

In another method shown in FIG.
(A) A preparation process in which a solvent and raw materials to be added are put into a tank, and dissolved and dispersed by mixing, stirring, and dispersing operations;
(C ′) The coating liquid is fed to the coating part in the order of the coating process for feeding and coating while filtering in the coating liquid feeding system.
In the case where the filtration treatment is performed as described above, since the filtration treatment can be performed immediately before the application, there is an advantage that the repelling component mixed in the steps such as liquid preparation and liquid feeding can be removed immediately before the application.

Also,
(A) A preparation process in which a solvent and raw materials to be added are put into a tank, and dissolved and dispersed by mixing, stirring, and dispersing operations;
(B) A filtration treatment step for filtering the liquid prepared in (a),
(C ′) It is further preferable to carry out the coating solution in the order of the coating step of feeding and coating the coating solution to the coating part while filtering in the coating solution feeding system.

Moreover, about the case where the addition component which affects filterability, such as translucent particle | grains, is added to a coating liquid, the filtration process can be performed by the method shown in FIG.
In the method shown in FIG.
(A) a step of adjusting a liquid that does not contain an additive component (particles or the like) that affects filterability, and that particularly includes a component that affects a repelling defect;
(B) A step of filtering the liquid prepared in (a) with a filter having a small pore diameter,
(C) A step of adding an additive component (d) A step of feeding and applying a coating solution to a coating part. At this time, in the step (a), it is also preferable to filter only the components that affect the repellency defect.
As shown in FIG. 2 (B), it is also preferable to further filter with a filter having a large pore size through which particles and the like can pass after the additive component is added. In this case, the filtration treatment after adding the additive component may be performed by providing a step different from the coating step (a → b → c → d ′ → e), or in the coating solution system. While applying the filtration treatment, the coating solution may be sent to the coating portion and applied (a → b → c → d ″). In the case of FIG. 2B, the filtration treatment of (b) is performed. You may abbreviate | omit a process and perform only the filtration process in (d ') or (d ").

Next, each component contained in the optical film according to the present invention will be described.
(Actinic radiation curable resin)
Examples of the at least one actinic radiation curable resin used in the optical film of the present invention include polyfunctional monomers and polyfunctional oligomers having radically polymerizable or cationically polymerizable groups.

Examples of the radical polymerizable functional group include an ethylenically unsaturated group such as a (meth) acryloyl group, a vinyloxy group, a styryl group, and an allyl group, and among them, a (meth) acryloyl group is preferable.
Examples of the cationic polymerizable group include an epoxy group, a cyclic thioether group, a cyclic ether group, a spiro orthoester group, a vinyl hydrocarbon group, and a vinyloxy group, and among them, an epoxy group and a vinyloxy group are preferable.

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

As these actinic radiation curable resins, preferably, resins having an acrylate functional group, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, Oligomers or prepolymers such as (meth) acrylates of polyfunctional compounds such as polybutadiene resins, polythiol polyene resins, and polyhydric alcohols (hereinafter, acrylate and methacrylate are referred to as (meth) acrylates). Can be mentioned.
Specific examples of the polyfunctional monomer include, for example, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, hexanediol (meth) acrylate, and tripropylene glycol. Di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and penta ( Examples thereof include a mixture of (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate and the like.
In addition, it is also preferable to mix a monofunctional monomer such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, vinyltoluene, N-vinylpyrrolidone and the like.

  The active radiation curable resin as described above is, for example, paragraph number of JP-A-2001-139663 as a polymerizable ester compound (monoester or polyester) of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid. [0026] to [0027] described compounds. Further, for example, vinyl methacrylate, allyl methacrylate, allyl acrylate, aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, and JP-A-2-226149. Those having an aromatic skeleton described above, and those having an amino group described in JP-A-1-165613 are also preferably used. In addition, it has a vinylurethane compound containing two or more polymerizable vinyl groups in one molecule (Japanese Patent Publication No. 48-41708), urethane acrylates (Japanese Patent Publication No. 2-16765), and an ethylene oxide skeleton. Urethane compounds (JP-B-62-39418, etc.), polyester acrylates (JP-B-52-30490, etc.)), and the light described in Journal of Japan Adhesion Association, Vol. 20 (7), 300-308 (1984) Curable monomers and oligomers can also be used.

  As these actinic radiation curable resins, those commercially available, for example, by manufacturers such as Nippon Kayaku Co., Ltd., Osaka Organic Chemical Co., Ltd., Dainippon Ink Chemical, Toa Gosei, Mitsubishi Chemical, etc. are used. be able to.

  Two or more of these actinic radiation curable resins may be used in combination. Of these, particularly preferred are pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and penta (meth) acrylate. A mixture, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate and the like.

(Organic silyl compound)
Next, an organic silyl compound represented by the following general formula a (generally known as silane coupling), a hydrolyzate of the organic silyl compound represented by the following general formula a or a partial condensate thereof will be described. To do. In addition, it is well known that the organic silyl compound represented by the general formula a is easily hydrolyzed and subsequently undergoes a dehydration condensation reaction.
Formula a
RmSi (X) n
(R represents a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted aryl group. X represents —OH, a halogen atom, —OR ¹ group, or OCOR ¹ group. R ¹ represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, m + n is 4, and m and n are each an integer of 0 or more, m is preferably 0, 1 or 2, and particularly preferably. 1)

  In the general formula a, R represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. As an alkyl group, it is C1-C30, Preferably it is C1-C16, More preferably, it is 1-6, For example, methyl, ethyl, propyl, isopropyl, hexyl, decyl, hexadecyl etc. are mentioned. As an aryl group, C6-C20 is preferable and 6-10 are more preferable, For example, phenyl, a naphthyl, etc. are mentioned, Preferably it is a phenyl group.

  The substituent for R is not particularly limited, but is a halogen atom (fluorine, chlorine, bromine, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl, ethyl, i-propyl, propyl, t -Butyl etc.), aryl groups (phenyl, naphthyl etc.), aromatic heterocyclic groups (furyl, pyrazolyl, pyridyl etc.), acyloxy groups (acetoxy, acryloyloxy, methacryloyloxy etc.), alkoxycarbonyl groups (methoxycarbonyl, ethoxycarbonyl) Etc.), aryloxycarbonyl group (phenoxycarbonyl etc.), carbamoyl group (carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl etc.), acylamino group (acetylamino, benzoylamino, acrylic Mino, methacrylamino etc.), and the like. These substituents may be further substituted. When there are a plurality of R, at least one is preferably a substituted alkyl group or a substituted aryl group.

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

  When a plurality of R or X are present, the plurality of R or X may be the same or different.

  Among the organic silyl compounds represented by the general formula a, compounds having a vinyl polymerizable substituent such as a methacryloyloxy group and an acryloyloxy group are particularly preferable. Specific examples include those described in paragraph numbers [0026] to [0028] of JP-A-2004-42278.

  The hydrolyzate and partial condensate of the organic silyl compound may be formed with water content in the coating solution, reaction progress, etc., or the organosilane compound is treated in the presence of a catalyst in advance. It may be manufactured. For hydrolysis and condensation, examples of the catalyst include acids, bases, and organometallic compounds.

  The optical film of the present invention contains at least one of the actinic radiation curable resin and the organic silyl compound (or hydrolyzate or partial condensate). Moreover, it is particularly preferable that the optical film of the present invention contains both an actinic radiation resin and an organic silyl compound (or hydrolyzate or partial condensate).

(solvent)
The optical film of the present invention can be produced by applying a coating solution containing an actinic radiation curable resin, an organic silyl compound and an organic solvent on a film substrate. Examples of the organic solvent include alcohols, ketones, esters, amides, ethers, ether esters, aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, and the like. The selection of these solvents is based on the solubility and reactivity of the components contained in the coating solution, the stability of the added particles, etc., the solubility / diffusibility in the coating underlayer, and the drying properties in the drying process. From the viewpoint of viscosity adjustment, etc. The composition of the solvent may be either single or mixed, but it is more preferable to mix appropriately in order to adjust the drying property, viscosity and the like. These solvents may be used as a mixture with a solvent other than an organic solvent such as water.

  Specific examples of the solvent include low-boiling solvents having a boiling point of 100 ° C. or lower, such as hexane (boiling point 68.7 ° C.), heptane (98.4), cyclohexane (80.7), benzene (80.1 ), Hydrocarbons such as dichloromethane (39.8), chloroform (61.2), carbon tetrachloride (76.8), 1,2-dichloroethane (83.5), halogens such as trichloroethylene (87.2) Hydrocarbons, ethers such as diethyl ether (34.6), diisopropyl ether (68.5), dipropyl ether (90.5), tetrahydrofuran (66), ethyl formate (54.2), methyl acetate ( 57.8), esters such as ethyl acetate (77.1), isopropyl acetate (89), acetone (56.1), 2-butanone (= methyl ethyl) Ketones: ketones such as MEK, 79.6), methanol (64.5), ethanol (78.3), 2-propanol (82.4), 1-propanol (97.2), 2-butanol (99) .5), alcohols such as t-butanol (82.5), cyano compounds such as acetonitrile (81.6) and propionitrile (97.4), and carbon disulfide (46.2). .

  Examples of the solvent having a boiling point of 100 ° C. or higher include, for example, octane (125.7 ° C., hereinafter “° C.” is omitted), toluene (110.6), xylene (138), tetrachloroethylene (121.2), and chlorobenzene. (131.7), dioxane (101.3), dibutyl ether (142.4), butyl acetate (126), isobutyl acetate (118), cyclohexanone (155.7), 2-methyl-4-pentanone (= methyl) Isobutyl ketone: MIBK, 115.9), 2-octanone (173), 1-butanol (117.7), iso-butanol (107.9), propylene glycol monomethyl ether (120), diacetone alcohol (168), N, N-dimethylformamide (153), N, N-dimethylacetamide (16 ), Dimethyl sulfoxide (189), and the like. However, the organic solvent of the present invention is not limited to the above.

Of the above solvents, ketones, alcohols, aromatic hydrocarbons, and esters are preferable, and ketones are particularly preferable. In particular, 2-butanone (MEK), 2-methyl-4-pentanone (MIBK), cyclohexanone, and the like are particularly preferable solvents.
Of the above solvents, it is also preferable to use a mixture of several solvents having different characteristics such as boiling point, solubility, and surface tension. In particular, mixing of high boiling point solvents with boiling points of 100 ° C or higher is intended to impart solubility of components, impart dispersion stability, suppress deterioration of drying unevenness due to rapid drying of the coating solution, and suppress increase in moisture content of the coating solution. ,preferable.
When this high-boiling solvent is contained, the repellency defect may be worsened due to the delay in drying. In such a case, the effect of the present invention is particularly great.

(Ingredient with surface activity)
In addition, for the coating liquid of the present invention, in order to improve coating properties, dry uniformization, impart high-speed coating suitability, either a fluorine-based or silicone-based component having a surfactant activity, or both, It is preferable to add to the coating composition. These surface active components may be added for surface wettability, antifouling property, dustproof property, chargeability adjustment, and the like. Since these silicone-based and fluorine-based surfactants often contain repellent components as contaminants and by-products, the coating solution is filtered even when these additives are added. It is effective.

  For example, when 100 ppm or more of a fluorine-based surface active compound is added to the coating solution, the concentration of the silicone-based surface active compound in the coating solution is preferably suppressed to 1 ppm or less. This is because, as described above, the silicone compound often contains a repelling component. When the addition amount of the compound having a silicone-based surface active action is 100 ppm or more, the fluorine-based surface active action is reversed. It is preferable to make the concentration of the compound having the content of 1 ppm or less in the coating solution.

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

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

  Examples of preferable silicone compounds include, but are not limited to, those described in paragraph No. [0068] of JP-A-2004-42278.

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

  The fluorine-based compound may be a polymer or an oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited and is used. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferable fluorine-based compounds include “R-2020”, “M-2020”, “R-3833”, “M-3833” [trade name: manufactured by Daikin Chemical Industries, Ltd.]; -171, F-172, F-179A, F-780-F, defender MCF-300 [trade name: manufactured by Dainippon Ink, Inc.] and the like, but are not limited thereto.

  Of the above additives, it is particularly preferable to contain a fluoroalkyl group-containing copolymer in the coating composition. This fluoroalkyl group-containing copolymer is preferable because an effect of improving surface defects such as coating unevenness, drying unevenness, and point defects of an optical film appears with a smaller addition amount.

  Further, when a coating such as a low refractive index layer is further formed on the coating layer, the additive preferably has a substituent that contributes to bond formation or compatibility. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like.

  Furthermore, by selecting the structure of the following fluoroalkyl group-containing copolymer, the copolymer unevenly distributed on the surface of the functional layer is extracted into the solvent of the upper layer when the upper layer (for example, a low refractive index layer) is applied, and the optical film of the present invention When the (antireflection film) is formed, it is also preferable not to exist on the functional layer surface (functional layer interface). Moreover, adjusting the addition amount of the fluoroaliphatic group-containing copolymer is also effective in improving the above effect.

  Specifically, such a method includes adding a fluoroaliphatic group-containing copolymer containing 10% by mass or more of a polymer unit of a fluoroaliphatic group-containing monomer in the coating solution, and then adding the fluoroaliphatic group-containing copolymer. In order to obtain segregation on the surface (which is an agreement with uneven distribution) and to obtain adhesion with the upper layer, a solvent of a coating solution for forming the upper layer is applied on the functional layer containing the fluoroaliphatic group-containing copolymer. In this method, the surface free energy of the functional layer is changed by 1 mN / m or more by drying, particularly 3 mN / m or more.

Furthermore, the fluoroalkyl group-containing copolymer (sometimes abbreviated as “fluorine polymer”) has a perfluoroalkyl group having 4 or more carbon atoms or a CF ₂ H-group having 4 or more carbon atoms in the side chain. It is preferable to use a copolymer having a fluoroalkyl group.
Among them, an acrylic resin, a methacrylic resin, and a copolymer capable of being copolymerized with a repeating unit (polymerization unit) corresponding to the monomer (i) below and a repeating unit (polymerization unit) corresponding to the monomer (ii) below. Copolymers with vinyl monomers are useful. Examples of such monomers include Polymer Handbook 2nd ed. , J .; Brandrup, Wiley Interscience (1975) Chapter 2 Pages 1-483 can be used.
For example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid, methacrylic acid, acrylic esters, methacrylic esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. I can give you.
Such compounds are the following compounds.
(I) Fluoroaliphatic group-containing monomer represented by the following general formula 2

In the general formula 2, R ¹ represents a hydrogen atom, a halogen atom or a methyl group, preferably a hydrogen atom or a methyl group. X represents an oxygen atom, a sulfur atom or —N (R ¹² ) —, more preferably an oxygen atom or —N (R ¹² ) —, and still more preferably an oxygen atom. R ¹² represents a hydrogen atom or an optionally substituted alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and further preferably a hydrogen atom or a methyl group. R _f represents —CF ₃ or —CF ₂ H.
M in the general formula 2 represents an integer of 1 to 6, more preferably 1 to 3, and still more preferably 1.
N in the general formula 2 represents an integer of 1 to 17, more preferably 4 to 11, and still more preferably 6 to 7. R _f is preferably —CF ₂ H.
In addition, two or more kinds of polymer units derived from the fluoroalkyl group-containing monomer represented by the general formula 2 may be contained as a constituent component in the fluorine-based polymer.
(Ii) Monomer represented by the following general formula 3 copolymerizable with the above (i)

In the above general formula 3, R ¹³ represents a hydrogen atom, a halogen atom or a methyl group, and more preferably a hydrogen atom or a methyl group. Y represents an oxygen atom, a sulfur atom or —N (R ¹⁵ ) —, more preferably an oxygen atom or —N (R ¹⁵ ) —, and still more preferably an oxygen atom. R ¹⁵ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and still more preferably a hydrogen atom or a methyl group.
R ¹⁴ is a linear, branched or cyclic alkyl group having 1 to 60 carbon atoms which may have a substituent, or an aromatic group which may have a substituent (for example, a phenyl group or a naphthyl group). ). The alkyl group may include a poly (alkyleneoxy) group. A linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, an alkyl group containing a poly (alkyleneoxy) group having 5 to 40 carbon atoms, or an aromatic group having 6 to 18 carbon atoms is more preferable. Alkyl groups including 8 linear, branched, or cyclic alkyl groups and poly (alkyleneoxy) groups having 5 to 30 carbon atoms are highly preferred. The poly (alkyleneoxy) group will be described below.

Poly (alkyleneoxy) groups can be represented by (OR) x, R is an alkylene group having 2 to 4 carbon atoms, such as _{-CH 2 CH 2 -, - CH} 2 CH 2 CH 2 -, - CH It is preferably (CH ₃ ) CH ₂ — or —CH (CH ₃ ) CH (CH ₃ ) —. x represents 2-30, 2-20 are preferable and 4-15 are more preferable.
The oxyalkylene units in the poly (oxyalkylene) group may be the same as poly (oxypropylene), or two or more different oxyalkylenes may be randomly distributed. For example, it may be a linear or branched oxypropylene or oxyethylene unit, or may be present as a block of linear or branched oxypropylene units and a block of oxyethylene units.
The poly (oxyalkylene) chain may also include those linked by one or more chain bonds (for example, —CONH—Ph—NHCO—, —S—, etc .: Ph represents a phenylene group). If the chain bond has a valence of 3 or more, this provides a means for obtaining branched oxyalkylene units. When this copolymer is used in the present invention, the molecular weight of the poly (oxyalkylene) group is suitably from 250 to 3,000.
Poly (oxyalkylene) acrylates and methacrylates are commercially available hydroxypoly (oxyalkylene) materials such as “Pluronic” (Asahi Denka Kogyo Co., Ltd.), Adeka Polyether (Asahi Denka Kogyo Co., Ltd.) ) "Carbowax (Glico Products)", "Triton" (Toriton (Rohm and Haas)) and PEG (Daiichi Kogyo Seiyaku Co., Ltd.) It can be produced by a known method by reacting with acrylic acid, methacrylic acid, acrylic chloride, methacryl chloride, acrylic acid anhydride, etc. Separately, poly (oxyalkylene) diacrylate produced by a known method can also be used.

  The amount of the fluoroaliphatic group-containing monomer represented by the general formula 2 used in the fluorine-based polymer is preferably 10% by mass or more based on the total amount of the monomer of the fluorine-based polymer, more preferably 50 It is more than mass%, More preferably, it is 70-100 mass%, Most preferably, it is the range of 80-100 mass%.

The preferred mass average molecular weight of the fluoropolymer used in the present invention is preferably 3000 to 100,000, more preferably 6,000 to 80,000, and still more preferably 8,000 to 60,000.
Here, the mass average molecular weight and the molecular weight are converted into polystyrene by GTH analyzer using a column of TSKgel GMHxL, TSKgel G4000HxL, TSKgel G2000HxL (both trade names manufactured by Tosoh Corporation) and solvent THF and differential refractometer detection. Is the molecular weight. The molecular weight was calculated from the peak area of 300 or more components.

  Furthermore, the preferable addition amount of the fluorine-based polymer is in the range of 0.001 to 5% by mass with respect to the mass of the coating liquid from the viewpoints of manifesting the effect of addition, drying, and suppressing the occurrence of surface failure. The range is preferably 0.005 to 3% by mass, and more preferably 0.01 to 1% by mass.

  Examples of the specific structure of the fluorine-based polymer are shown below, but this is not restrictive. In addition, the number in a formula shows the molar ratio of each monomer component. Mw represents a mass average molecular weight.

  The use ratio of the above-mentioned actinic radiation curable resin, organic silyl compound, component having a surface active action, and a solvent can be appropriately set according to the use of the optical film.

  Next, each coating layer of an optical film is demonstrated according to the use of the optical film of this invention. The coating layer in the optical film of the present invention has properties such as an optical functional layer and a physical functional layer. Examples of the optical functional layer include an antiglare layer, a light diffusion layer, a low refractive index layer, a high refractive index layer, an optical compensation layer, and the like. Examples of the physical functional layer include a hard coat layer. Of course, the optical functional layer may also serve as a physical functional layer, for example, an antiglare hard coat layer.

[Method for producing optical film]
The method for producing an optical film according to the present invention comprises applying a coating liquid containing a solvent, an actinic radiation curable resin and / or an organic silyl compound represented by the following general formula a, a hydrolyzate thereof or a partial condensate thereof to a polyolefin: A step of filtering with a depth type filter having a filter material made of the product, and a step of applying the filtered composition onto a film substrate to form a coating layer.
About the process of filtering, it is as having demonstrated above.
After filtration, it is coated on a transparent support, heated and dried. Thereafter, the monomer for forming the optical functional layer is polymerized and cured by light irradiation or heating to form the optical functional layer. Here, if necessary, the optical functional layer may be formed into a plurality of layers, and the application and curing of the optical functional layer may be repeated and laminated by the same method.

As a coating method, a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method or an extrusion coating method (see US Pat. No. 2,681,294) can be used. It is preferable to use a wire bar coating method, an extrusion coating method, or a micro gravure coating method, and it is particularly preferable to use a micro gravure coating method.
It is also preferable to apply by using a die coating method. Furthermore, it is more preferable to perform coating using a die whose configuration is devised as described in JP-A-2003-211052.
For repelling defects, a large amount of coating solution in the liquid state is disadvantageous because the drying time becomes long and the formation time of repelling becomes long, which is disadvantageous. It becomes. A desirable coating amount in a liquid state is 1 cc to 40 cc per 1 m ² , and particularly preferably ² cc to 25 cc. The coating layer thickness of the optical functional layer is preferably 0.01 μm or more and 20 μm or less, and particularly preferably 0.05 μm or more and 10 μm or less.

  The micro gravure coating method used in the present invention is a gravure roll having a diameter of about 10 to 100 mm, preferably about 20 to 50 mm and engraved with a gravure pattern on the entire circumference, below the support and in the transport direction of the support. The gravure roll is rotated in reverse with respect to the gravure roll, the excess coating liquid is scraped off from the surface of the gravure roll by a doctor blade, and a fixed amount of the coating liquid is removed from the support in a position where the upper surface of the support is in a free state The coating method is characterized in that the coating liquid is transferred onto the lower surface for coating. A roll-shaped transparent support is continuously unwound, and at least one of at least an optical functional layer or a low refractive index layer containing a fluorine-containing polymer is provided on one side of the unwound support. Can be applied by.

  As coating conditions by the micro gravure coating method, the number of gravure patterns engraved on the gravure roll is preferably 50 to 800 / inch, more preferably 100 to 300 / inch, and the depth of the gravure pattern is 1 to 600 μm. Is preferable, 5 to 200 μm is more preferable, the rotation speed of the gravure roll is preferably 3 to 800 rpm, more preferably 5 to 200 rpm, and the conveyance speed of the support is 0.5 to 100 m / min. It is preferably 1 to 50 m / min.

[Antireflection film]
The optical film of the present invention can be used as an antireflection film.
As an embodiment of the optical film of the present invention, a basic configuration of an antireflection film will be described with reference to the drawings.
Fig.3 (a) is sectional drawing which shows an example of an antireflection film typically. As shown to Fig.3 (a), the antireflection film 1 is the order of the transparent support body 2, three types of functional layers (the hard-coat layer 3, the glare-proof hard coat layer 4, and the low-refractive-index layer 5). It has a layer structure. Matte particles 6 are dispersed in the antiglare hard coat layer 4, and the refractive index of the material other than the matte particles 6 of the antiglare hard coat layer 4 is in the range of 1.50 to 2.00. The refractive index of the low refractive index layer 5 is preferably in the range of 1.35 to 1.49. The functional layer in the antireflection film may be a hard coat layer having an antiglare property, a hard coat layer having no antiglare property, a light diffusing layer, a single layer, or a plurality of layers. For example, it may be composed of 2 to 4 layers. The low refractive index layer which is a functional layer is coated on the outermost layer.

Further, the low refractive index layer preferably satisfies the following formula (VII) from the viewpoint of reducing the reflectance.
Formula (VII)
(Mλ / 4) × 0.7 <n ₃ d ₃ <(mλ / 4) × 1.3
In the formula, m is a positive odd number, n ₃ is the refractive index of the low refractive index layer, and d ₃ is the film thickness (nm) of the low refractive index layer. Further, λ is a wavelength, which is a value in the range of 500 to 550 nm.
In addition, satisfy | filling said numerical formula (VII) means that m (positive odd number, usually 1) which satisfy | fills numerical formula (VII) exists in the said wavelength range.

FIG. 3B is a cross-sectional view schematically showing another example of the antireflection film. As shown in FIG. 2 (b), the antireflection film 1 comprises a transparent support 2, each functional layer (hard coat layer 3, medium refractive index layer 7, high refractive index layer 8), low refractive index layer (the highest refractive index layer). The outer layer has a layer structure in the order of 5. The transparent support 2, the medium refractive index layer 7, the high refractive index layer 8, and the low refractive index layer 5 have refractive indexes that satisfy the following relationship.
Refractive index of high refractive index layer> refractive index of medium refractive index layer> refractive index of transparent support> refractive index of low refractive index layer

  In the layer structure as shown in FIG. 3B, as described in JP-A-59-50401, the medium refractive index layer is represented by the following mathematical formula (I), and the high refractive index layer is represented by the following mathematical formula (II). It is preferable that the low refractive index layer satisfies the following formula (III) in that an antireflection film having more excellent antireflection performance can be produced.

Formula (I)
(Hλ / 4) × 0.7 <n ₁ d ₁ <(hλ / 4) × 1.3
In the formula (I), h is a positive integer (generally 1, 2 or 3), n ₁ is the refractive index of the medium refractive index layer, and d ₁ is the layer thickness (nm) of the medium refractive index layer. It is. λ is the wavelength (nm) of visible light, and is a value in the range of 380 to 680 nm.

Formula (II)
(Iλ / 4) × 0.7 <n ₂ d ₂ <(iλ / 4) × 1.3
In formula (II), i is a positive integer (generally 1, 2 or 3), n ₂ is the refractive index of the high refractive index layer, and d ₂ is the layer thickness (nm) of the high refractive index layer. It is. λ is the wavelength (nm) of visible light, and is a value in the range of 380 to 680 nm.

Formula (III)
(Jλ / 4) × 0.7 <n ₃ d ₃ <(jλ / 4) × 1.3
In formula (III), j is a positive odd number (generally 1), n ₃ is the refractive index of the low refractive index layer, and d ₃ is the layer thickness (nm) of the low refractive index layer. λ is the wavelength (nm) of visible light, and is a value in the range of 380 to 680 nm.

In the layer configuration as shown in FIG. 3B, the medium refractive index layer satisfies the following formula (IV), the high refractive index layer satisfies the following formula (V), and the low refractive index layer satisfies the following formula (VI). Is particularly preferred. Here, λ is 500 nm, h is 1, i is 2, and j is 1.
Formula (IV)
(Hλ / 4) × 0.80 <n ₁ d ₁ <(hλ / 4) × 1.00
Formula (V)
(Iλ / 4) × 0.75 <n ₂ d ₂ <(iλ / 4) × 0.95
Formula (VI)
(Jλ / 4) × 0.95 <n ₃ d ₃ <(jλ / 4) × 1.05

  The high refractive index, medium refractive index, and low refractive index described here refer to the relative refractive index between layers. Moreover, in FIG.3 (b), the high refractive index layer is used as a light interference layer, and the antireflection film which has the very outstanding antireflection performance can be produced.

Next, each functional layer in the antireflection film will be described.
(Anti-glare hard coat layer)
The antiglare hard coat layer is usually composed of a binder for imparting hard coat properties, mat particles for imparting antiglare properties, and an inorganic filler for increasing the refractive index, preventing cross-linking shrinkage, and increasing strength. Formed from. Hereinafter, each component contained in the antiglare hard coat layer will be described.

<Binder>
The binder is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as the main chain, and more preferably a polymer having a saturated hydrocarbon chain as the main chain. The binder polymer preferably has a crosslinked structure.
As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer (binder precursor) is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable.
In order to obtain a high refractive index, the monomer structure preferably contains an aromatic ring or at least one atom selected from a halogen atom other than fluorine, a sulfur atom, a phosphorus atom, and a nitrogen atom.

  Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra ( (Meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, cyclohexane-1,2,3 triol trimethacrylate, polyurethane polyacrylate, polyester Terpolyacrylate), vinylbenzene and its derivatives (eg, 1,4-vinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-vinylcyclohexanone), vinylsulfone (eg, divinylsulfone), acrylamide (Eg, methylenebisacrylamide) and methacrylamide. Two or more of these monomers may be used in combination.

  Specific examples of the high refractive index monomer include bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide, 4-methacryloxyphenyl-4′-methoxyphenyl thioether, and the like. Two or more of these monomers may be used in combination.

Polymerization of these monomers having an ethylenically unsaturated group can be carried out by irradiation with actinic radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.
Therefore, a coating liquid containing a monomer having an ethylenically unsaturated group, a photo radical initiator or a thermal radical initiator, mat particles and an inorganic filler is prepared, and the coating liquid is applied on a transparent support, and then actinic radiation or It can be cured by a polymerization reaction by heat to form an antireflection film.

  As radical photopolymerization initiators, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-alkyldione compounds, disulfide compounds And fluoroamine compounds and aromatic sulfoniums. Examples of acetophenones include 2,2-ethoxyacetophenone, p-methylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone and 2- Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone is included. Examples of benzoins include benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether. Examples of benzophenones include benzophenone, 2,4-chlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

Various examples are described in the latest UV curing technology (P.159, issuer; Kazuhiro Takasagi, publisher; Technical Information Association, Inc., published in 1991), which is useful for the present invention.
Preferable examples of commercially available photocleavable photoradical polymerization initiators include Irgacure (651, 184, 907) manufactured by Nippon Ciba-Geigy Co., Ltd.
Further, as described in JP-A-6-41468, it is also preferably used in combination of two photopolymerization initiators.
It is preferable to use a photoinitiator in the range of 0.1-15 mass parts with respect to 100 mass parts of polyfunctional monomers, More preferably, it is the range of 1-10 mass parts.
In addition to the photopolymerization initiator, a photosensitizer may be used. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone and thioxanthone.

As the thermal radical initiator, organic or inorganic peroxides, organic azo, diazo compounds, and the like can be used.
Specifically, benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, butyl hydroperoxide as organic peroxides, hydrogen peroxide, peroxides as inorganic peroxides. Ammonium sulfate, potassium persulfate, etc., 2-azo-bis-isobutyronitrile, 2-azo-bis-propionitrile, 2-azo-bis-cyclohexanedinitrile, etc. as diazo compounds, diazoaminobenzene, p-nitrobenzenediazonium Etc. can be mentioned.

The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with actinic radiation or heating in the presence of a photoacid generator or a thermal acid generator.
Therefore, a coating liquid containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, matte particles and an inorganic filler is prepared, and the coating liquid is applied onto a transparent support, and then a polymerization reaction by actinic radiation or heat. Can be cured to form an antireflection film.

Instead of or in addition to a monomer having two or more ethylenically unsaturated groups, a monomer having a crosslinkable functional group is used to introduce a crosslinkable functional group into the polymer, and by reaction of this crosslinkable functional group, A crosslinked structure may be introduced into the binder polymer.
Examples of the crosslinkable functional group include isocyanate group, epoxy group, aziridine group, oxazoline group, aldehyde group, carbonyl group, hydrazine group, carboxyl group, methylol group and active methylene group. Vinylsulfonic acid, acid anhydrides, cyanoacrylate derivatives, melamine, etherified methylol, esters and urethanes, and metal alkoxides such as tetramethoxysilane can also be used as monomers for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. That is, in the present invention, the crosslinkable functional group may not react immediately but may exhibit reactivity as a result of decomposition.
These binder polymers having a crosslinkable functional group can form a crosslinked structure by heating after coating.

  The binder of the antiglare hard coat layer is added in an amount of 20 to 95% by mass based on the solid content of the coating composition of the layer.

<Translucent particles>
In the optical film of the present invention, in particular, the antiglare film, the light scattering film, and the antireflection film, the translucent particles are used for controlling the refractive index of the constituent layer, surface scattering / internal scattering, and imparting the strength of the constituent layer. Often included. Specific examples of the translucent particles include matte particles used for the antiglare layer, particles used for the light scattering layer, particles used for the refractive index adjusting layer, inorganic filler, and the like.
<Matte particles>
For the purpose of imparting antiglare properties, the antiglare hard coat layer is a matte particle having an average particle size of 1 to 10 μm, preferably 1.5 to 7.0 μm, such as inorganic compound particles or resin, for the purpose of imparting antiglare properties. Contains particles.
As specific examples of the mat particles, inorganic particles such as silica particles and TiO ₂ particles; resin particles such as acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine resin particles, and benzoguanamine resin particles are preferable. Can be mentioned. Of these, crosslinked styrene particles, crosslinked acrylic particles, and silica particles are preferred.
The shape of the mat particles can be either a true sphere or an indefinite shape.

  Two or more kinds of mat particles having different particle diameters may be used in combination. It is possible to impart anti-glare properties with mat particles having a larger particle size and to impart other optical characteristics with mat particles having a smaller particle size. For example, when an antireflection film is attached to a high-definition display of 133 ppi or higher, it is required that there is no problem in optical performance called glare. Glare originates from the fact that the pixels are enlarged or reduced due to unevenness existing on the film surface (contributing to anti-glare properties) and lose uniformity of brightness, but with a particle size smaller than that of mat particles that provide anti-glare properties. It can be greatly improved by using mat particles having a different refractive index from the binder.

  Furthermore, the particle size distribution of the mat particles is most preferably monodisperse, and the particle sizes of the particles are preferably closer to each other. For example, when a particle having a particle size of 20% or more than the average particle size is defined as a coarse particle, the proportion of the coarse particle is preferably 1% or less, more preferably 0.1% of the total number of particles. Or less, more preferably 0.01% or less. Matt particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and a matting agent having a more preferable distribution can be obtained by increasing the number of classifications or increasing the degree of classification.

The mat particles are contained in the anti-glare hard coat layer so that the amount of the mat particles in the formed anti-glare hard coat layer is preferably 10 to 2000 mg / m ² , more preferably 100 to 1400 mg / m ^2. Is done.
The particle size distribution of the mat particles can be measured by a Coulter counter method, and the measured distribution can be converted into a particle number distribution.

<Inorganic filler>
In order to increase the refractive index of the antiglare hard coat layer, in addition to the above mat particles, at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony is used. It is preferable to contain an inorganic filler made of an oxide and having an average particle diameter of 0.2 μm or less, preferably 0.1 μm or less, more preferably 0.06 μm or less.
Conversely, in order to increase the difference in refractive index from the mat particles, an anti-glare hard coat layer using high refractive index mat particles uses silicon oxide to keep the refractive index of the layer low. Is also preferable. The preferred particle size is the same as that of the aforementioned inorganic filler.
Specific examples of the inorganic filler for use in the antiglare hard coat _{layer, TiO 2, ZrO 2, Al} 2 O 3, In 2 O 3, ZnO, SnO 2, Sb 2 O 3, ITO and SiO ₂ or the like can be mentioned It is done. TiO ₂ and ZrO ₂ are particularly preferable in terms of increasing the refractive index. The surface of the inorganic filler is preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.
The amount of these inorganic fillers added is preferably 10 to 90% of the total mass of the antiglare hard coat layer, more preferably 20 to 80%, and particularly preferably 30 to 75%.
In addition, since such a filler has a particle size sufficiently smaller than the wavelength of light, scattering does not occur, and a dispersion in which the filler is dispersed in a binder polymer behaves as an optically uniform substance.

  The bulk refractive index of the mixture of binder and inorganic filler in the antiglare hard coat layer of the present invention is preferably 1.48 to 2.00, more preferably 1.50 to 1.80. In order to make the refractive index within the above range, the kind and amount ratio of the binder and the inorganic filler may be appropriately selected. How to select can be easily known experimentally in advance.

  The film thickness of the antiglare hard coat layer is preferably 1 to 10 μm, and more preferably 1.2 to 8 μm.

<Method for forming antiglare hard coat layer>
The antiglare hard coat layer is prepared by preparing a coating solution containing the above components and then applying the solution onto a support or another layer, and if necessary, a crosslinking reaction or a polymerization reaction of an actinic radiation curable compound. It can be formed by doing. In addition, when a photopolymerizable polyfunctional monomer is included, the photopolymerization reaction is preferably performed by ultraviolet irradiation.
Further, the antiglare imparting layer such as the antiglare layer or the antiglare hard coat layer contains the active radiation curable resin and / or the organic silyl compound represented by the general formula a described above. In many cases, in the case of an antireflection film, a repelling component that causes point defects may be contained, particularly in the antiglare layer and the antiglare hard coat layer. Therefore, it is desirable to remove the repelling component by performing the above-described filtration treatment on these layers. By performing the above filtration treatment on the antiglare layer and the antiglare hard coat layer, the number of point defects of 100 μm or more in these layers can be 2 or less per 1 m ² of film.

When a crosslinking reaction or a polymerization reaction of an actinic radiation curable compound is performed, the crosslinking reaction or the polymerization reaction is preferably performed in an atmosphere having an oxygen concentration of 10% by volume or less. By forming in an atmosphere having an oxygen concentration of 10% by volume or less, a hard coat layer excellent in physical strength and chemical resistance can be formed.
Preferably, it is formed by a crosslinking reaction or a polymerization reaction of an actinic radiation curable compound in an atmosphere having an oxygen concentration of 6% by volume or less, more preferably an oxygen concentration of 4% by volume or less, particularly preferably an oxygen concentration of 2 Volume% or less, most preferably 1 volume% or less.

  As a method of reducing the oxygen concentration to 10% by volume or less, it is preferable to replace the atmosphere (nitrogen concentration of about 79% by volume, oxygen concentration of about 21% by volume) with another gas, particularly preferably replacement with nitrogen (nitrogen purge). It is to be.

(Light diffusion layer)
You may provide a light-diffusion layer in an antireflection film. The light diffusion layer can be provided as a part of the constituent layer on the side where the antireflection layer is formed, or can be disposed on the opposite side of the antireflection layer forming surface. In particular, it is preferably provided on the side where the antireflection layer is formed.
The purpose of the light diffusing layer in the antireflection film is to increase the viewing angle (particularly the downward viewing angle) of the liquid crystal display device, and to reduce contrast, gradation or black-and-white reversal, or hue change even if the viewing angle in the viewing direction changes. It is to deter.
The present inventors have confirmed that the intensity distribution of scattered light measured with a goniophotometer correlates with the viewing angle improvement effect. That is, as the light emitted from the backlight is diffused by the effect of internal scattering of the translucent fine particles contained in the light diffusion film installed on the surface of the polarizing plate on the viewing side, the viewing angle characteristics are improved. However, if it is diffused too much, backscattering will increase and the front luminance will decrease, or the scattering will be too great and the image clarity will deteriorate. Therefore, it is necessary to control the scattered light intensity distribution within a certain range. Therefore, as a result of intensive studies, in order to achieve the desired visual characteristics, the scattered light intensity at 30 °, which correlates particularly with the visual angle improvement effect, is 0.01 with respect to the light intensity at the output angle 0 ° of the scattered light profile. % To 0.2% is preferable, 0.02% to 0.15% is more preferable, and 0.03% to 0.1% is particularly preferable.
The scattered light profile can be measured using the automatic variable angle photometer GP-5 manufactured by Murakami Color Research Laboratory Co., Ltd. for the created light scattering film.

The light diffusing layer of the present invention is formed from a binder, an inorganic filler and translucent fine particles, and the binder and the inorganic filler can be the same as those used in the above-mentioned antiglare hard coat layer. The same as is used.
The binder of the light diffusing layer is preferably added in an amount of 5 to 80% by mass based on the solid content of the coating composition of the layer.

(Hard coat layer)
As the hard coat layer, a so-called smooth hard coat layer that is not anti-glare to impart physical strength to the antireflection film is also preferably used, and is provided on the surface of the transparent support. In particular, the transparent support and the antiglare hard coat layer, the transparent support and the light diffusion layer, and the transparent support and the high refractive index layer are preferably provided.
The hard coat layer includes a binder for imparting hard coat properties and an inorganic filler for increasing the refractive index, preventing crosslinking shrinkage, and increasing the strength.
As the binder for imparting hard coat properties, a functional group of an actinic radiation curable polyfunctional monomer or polyfunctional oligomer can be used. The functional group of the active radiation curable polyfunctional monomer or polyfunctional oligomer is preferably a light, electron beam, or radiation polymerizable group, and among them, a photopolymerizable functional group is preferable. Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group is preferable.
Specific examples of the actinic radiation curable polyfunctional monomer or polyfunctional oligomer may be the same as those described in the above “antiglare hard coat layer”. Specific examples of the photopolymerizable polyfunctional monomer having a photopolymerizable functional group include those exemplified for the high refractive index layer, and polymerization can be performed using a photopolymerization initiator and a photosensitizer.
The binder of the hard coat layer is added in an amount of 30 to 95% by mass based on the solid content of the coating composition of the layer.

The hard coat layer preferably contains inorganic fine particles (inorganic filler) having an average primary particle size of 200 nm or less. The average particle diameter here is a mass average diameter. By setting the average particle size of the primary particles to 200 nm or less, a hard coat layer that does not impair transparency can be formed.
The inorganic fine particles have functions of increasing the hardness of the hard coat layer and suppressing curing shrinkage of the coating layer. It is also added for the purpose of controlling the refractive index of the hard coat layer.
As the inorganic fine particles, in addition to the inorganic fine particles exemplified in the high refractive index layer described later, silicon dioxide, aluminum oxide, calcium carbonate, barium sulfate, talc, kaolin, calcium sulfate, titanium dioxide, zirconium oxide, tin oxide, ITO, oxidation Fine particles such as zinc may be mentioned. Silicon dioxide, titanium dioxide, zirconium oxide, aluminum oxide, tin oxide, ITO, and zinc oxide are preferable.

The preferable average particle diameter of the primary particles of the inorganic fine particles is 5 to 200 nm, more preferably 10 to 150 nm, still more preferably 20 to 100 nm, and particularly preferably 20 to 50 nm.
In the hard coat layer, the inorganic fine particles are preferably dispersed as finely as possible.
The particle size of the inorganic fine particles in the hard coat layer is preferably 5 to 300 nm, more preferably 10 to 200 nm, more preferably 20 to 150 nm, and particularly preferably 20 to 80 nm in terms of average particle diameter.

  The content of the inorganic fine particles in the hard coat layer is preferably 10 to 90% by mass, more preferably 15 to 80% by mass, and particularly preferably 15 to 75% by mass with respect to the total mass of the hard coat layer.

  The film thickness of the hard coat layer can be appropriately designed depending on the application. The film thickness of the hard coat layer is preferably 0.2 to 10 μm, more preferably 0.5 to 7 μm, and particularly preferably 0.7 to 5 μm.

The strength of the hard coat layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400.
Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

<Method for forming hard coat layer>
The hard coat layer is formed by preparing a coating solution containing the above components and then applying the solution on a support or another layer, and performing a crosslinking reaction or a polymerization reaction of the active radiation curable compound as necessary. be able to. The crosslinking reaction or polymerization reaction of the actinic radiation curable compound can be carried out in the same manner as in the antiglare hard coat layer. In addition, about the coating liquid for forming a hard-coat layer, the process mentioned above may be performed or it is not necessary to perform it.

(High refractive index layer)
The refractive index of the high refractive index layer is preferably 1.55 to 2.40, which is a so-called high refractive index layer or a medium refractive index layer. In this specification, this layer is referred to as a high refractive index layer. It will be called generically.
Hereinafter, each component used for the high refractive index layer will be described.
<Inorganic fine particles mainly composed of titanium dioxide>
The high refractive index layer of the antireflection film preferably contains inorganic fine particles mainly composed of titanium dioxide containing at least one element selected from cobalt, aluminum, and zirconium. The main component means a component having the largest content (mass%) among the components constituting the particles. The inorganic fine particles have a function of controlling the refractive index of the high refractive index layer and a function of suppressing curing shrinkage.
The inorganic fine particles mainly composed of titanium dioxide preferably have a refractive index of 1.90 to 2.80, more preferably 2.10 to 2.80, and 2.20 to 2.80. Most preferred.
The mass average diameter of primary particles of inorganic fine particles mainly composed of titanium dioxide is preferably 1 to 200 nm, more preferably 1 to 150 nm, still more preferably 1 to 100 nm, and particularly preferably 1 to 80 nm.

The particle diameter of the inorganic fine particles can be measured by a light scattering method or an electron micrograph. The specific surface area of the inorganic fine particles is preferably 10 to 400 m ² / g, more preferably from 20 to 200 m ² / g, and most preferably from 30 to 150 m ² / g.
The crystal structure of the inorganic fine particles containing titanium dioxide as the main component is preferably a rutile, rutile / anatase mixed crystal, anatase or amorphous structure, particularly preferably a rutile structure. The main component means a component having the largest content (mass%) among the components constituting the particles.

By containing at least one element selected from Co, Al and Zr in the inorganic fine particles mainly composed of titanium dioxide, the photocatalytic activity of titanium dioxide can be suppressed, and the weather resistance of the high refractive index layer is improved. can do.
In particular, the preferred element is Co. It is also preferable to use two or more types in combination.
The content of Co, Al or Zr with respect to Ti is preferably 0.05 to 30% by mass, more preferably 0.1 to 10% by mass, and still more preferably 0.2 to 7% by mass with respect to Ti. %, Particularly preferably 0.3 to 5% by mass, most preferably 0.5 to 3% by mass.
Co, Al, and Zr can be present in at least one of the inside and the surface of the inorganic fine particles mainly composed of titanium dioxide, but are preferably present inside the inorganic fine particles mainly composed of titanium dioxide, Most preferably it is present both inside and on the surface.
There are various methods for causing Co, Al, and Zr to exist (for example, dope) in the inorganic fine particles mainly composed of titanium dioxide. For example, ion implantation (Vol.18, No.5, pp.262-268, 1998; Yasushi Aoki), JP-A-11-263620, JP-A-11-512336, European Patent Application Publication No. 0335773. And the method described in JP-A-5-330825.
Techniques for introducing Co, Al, and Zr in the process of forming inorganic fine particles containing titanium dioxide as a main component (for example, Japanese Patent Application Laid-Open No. 11-512336, European Patent Application Publication No. 0335773, Japanese Patent Application Laid-Open No. Hei 5- No. 330308) is particularly preferable.
Co, Al, and Zr are also preferably present as oxides.
The inorganic fine particles containing titanium dioxide as the main component can further contain other elements depending on the purpose. Other elements may be included as impurities. Examples of other elements include Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Mg, Si, P, and S.

The inorganic fine particles mainly composed of titanium dioxide used in the present invention may be surface-treated. The surface treatment is performed using an inorganic compound or an organic compound. Examples of inorganic compounds used for the surface treatment include inorganic compounds containing cobalt (CoO ₂ , Co ₂ O ₃ , Co ₃ O _4, etc.) and inorganic compounds containing aluminum (Al ₂ O ₃ , Al (OH) ₃ Etc.), inorganic compounds containing zirconium (ZrO ₂ , Zr (OH) ₄ etc.), inorganic compounds containing silicon (SiO ₂ etc.), inorganic compounds containing iron (Fe ₂ O ₃ etc.), etc. .
An inorganic compound containing cobalt, an inorganic compound containing aluminum, and an inorganic compound containing zirconium are particularly preferable, and an inorganic compound containing cobalt, Al (OH) ₃ , and Zr (OH) ₄ are most preferable.
Examples of organic compounds used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Silane coupling agents are most preferred. In particular, the surface treatment is preferably performed with at least one of a silane coupling agent (organosilane compound) represented by the following general formula 5, a partial hydrolyzate thereof, and a condensate thereof. The silane coupling agent represented by the general formula 5 will be described in detail later.

Examples of titanate coupling agents include metal alkoxides such as tetramethoxy titanium, tetraethoxy titanium, and throat tetraisopropoxy titanium, preneact (KR-TTS, KR-46B, KR-55, KR-41B, etc .; Ajinomoto Co., Inc. ))).
Examples of the organic compound used for the surface treatment include polyols, alkanolamines, and other organic compounds having an anionic group, and particularly preferable are organic compounds having a carboxyl group, a sulfonic acid group, or a phosphoric acid group. is there.
Stearic acid, lauric acid, oleic acid, linoleic acid, linolenic acid and the like can be preferably used.
The organic compound used for the surface treatment preferably further has a crosslinked or polymerizable functional group. Crosslinkable or polymerizable functional groups include ethylenically unsaturated groups (for example, (meth) acrylic groups, allyl groups, styryl groups, vinyloxy groups, etc.) that can undergo addition reactions and polymerization reactions with radical species, cationic polymerizable groups (Epoxy groups, oxatanyl groups, vinyloxy groups, etc.), polycondensation reactive groups (hydrolyzable silyl groups, etc., N-methylol groups) and the like can be mentioned, and groups having an ethylenically unsaturated group are preferred.

Two or more kinds of these surface treatments can be used in combination. It is particularly preferable to use an inorganic compound containing aluminum and an inorganic compound containing zirconium in combination.
The inorganic fine particles mainly composed of titanium dioxide of the present invention may have a core / shell structure by surface treatment as described in JP-A No. 2001-166104.

  The shape of the inorganic fine particles mainly composed of titanium dioxide contained in the high refractive index layer is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape or an indefinite shape, and particularly preferably an indefinite shape or a spindle shape. is there.

  The content of the inorganic fine particles in the high refractive index layer is preferably 10 to 90% by mass, more preferably 15 to 80% by mass, and particularly preferably 15 to 75% by mass with respect to the mass of the high refractive index layer. . Two or more inorganic fine particles may be used in combination in the high refractive index layer.

<Dispersant>
A dispersant can be used for dispersing the inorganic fine particles mainly composed of titanium dioxide, and it is particularly preferable to use a dispersant having an anionic group.
As the anionic group, a group having an acidic proton such as a carboxyl group, a sulfonic acid group (and a sulfo group), a phosphoric acid group (and a phosphono group), or a sulfonamide group, or a salt thereof is effective. A sulfonic acid group, a phosphoric acid group and a salt thereof are preferable, and a carboxyl group and a phosphoric acid group are particularly preferable. The number of anionic groups contained in the dispersant per molecule may be one or more.
A plurality of anionic groups may be contained for the purpose of further improving the dispersibility of the inorganic fine particles. The average number is preferably 2 or more, more preferably 5 or more, and particularly preferably 10 or more. Moreover, the anionic group contained in a dispersing agent may contain multiple types in 1 molecule.

The dispersant preferably further contains a crosslinkable or polymerizable functional group. Crosslinkable or polymerizable functional groups include ethylenically unsaturated groups (for example, (meth) acryloyl groups, allyl groups, styryl groups, vinyloxy groups, etc.) that can undergo addition reactions and polymerization reactions with radical species, and cationic polymerizable groups (epoxy Groups, oxatanyl groups, vinyloxy groups, etc.), polycondensation reactive groups (hydrolyzable silyl groups, etc., N-methylol groups) and the like, and functional groups having an ethylenically unsaturated group are preferred.
A preferred dispersant used for dispersion of inorganic fine particles mainly composed of titanium dioxide is a dispersant having an anionic group and a crosslinkable or polymerizable functional group and having the crosslinkable or polymerizable functional group in a side chain. .
The weight average molecular weight (Mw) of the dispersant having an anionic group and a crosslinkable or polymerizable functional group and having the crosslinkable or polymerizable functional group in the side chain is not particularly limited, but is preferably 1000 or more. . The more preferable weight average molecular weight (Mw) of the dispersant is 2,000 to 1,000,000, more preferably 5,000 to 200,000, and particularly preferably 10,000 to 100,000.

  As the anionic group, a group having an acidic proton such as a carboxyl group, a sulfonic acid group (sulfo), a phosphoric acid group (phosphono), a sulfonamide group, or a salt thereof is effective, and in particular, a carboxyl group, a sulfonic acid group, A phosphoric acid group or a salt thereof is preferable, and a carboxyl group and a phosphoric acid group are particularly preferable. The average number of anionic groups contained in the dispersant per molecule is preferably 2 or more, more preferably 5 or more, and particularly preferably 10 or more. Moreover, the anionic group contained in a dispersing agent may contain multiple types in 1 molecule.

The dispersant having an anionic group and a crosslinkable or polymerizable functional group and having the crosslinkable or polymerizable functional group in the side chain has the anionic group in the side chain or terminal. Particularly preferred dispersants are those having an anionic group in the side chain. In the dispersant having an anionic group in the side chain, the composition of the anionic group-containing repeating unit is in the range of 10 ^{−4 to} 100 mol%, preferably 1 to 50 mol%, particularly preferably 5 in the total repeating units. ˜20 mol%.

  Examples of the cross-linkable or polymerizable functional group include ethylenically unsaturated groups (for example, (meth) acryl group, allyl group, styryl group, vinyloxy group, etc.) capable of addition reaction / polymerization reaction with radical species, cationic polymerizable group (epoxy) Groups, oxatanyl groups, vinyloxy groups, etc.), polycondensation reactive groups (hydrolyzable silyl groups, etc., N-methylol groups), and the like. Preferred are groups having an ethylenically unsaturated group.

  The average number of cross-linkable or polymerizable functional groups contained in the dispersant per molecule is preferably 2 or more, more preferably 5 or more, and particularly preferably 10 or more. Moreover, the crosslinking or polymerizable functional group contained in the dispersant may contain a plurality of types in one molecule.

Examples of repeating units having an ethylenically unsaturated group in the side chain, which is a preferred dispersant, include poly-1,2-butadiene and poly-1,2-isoprene structures, or esters or amides of (meth) acrylic acid. A repeating unit having a specific residue (the R group of —COOR or —CONHR) bound thereto can be used. Examples of the specific residue (R group) include-(CH ₂ ) n-CR ₂₁ = CR ₂₂ R ₂₃ ,-(CH ₂ O) n-CH ₂ CR ₂₁ = CR ₂₂ R ₂₃ ,-(CH ₂ CH ₂ O) n-CH ₂ CR ₂₁ = CR ₂₂ R ₂₃ ,-(CH ₂ ) n-NH-CO-O-CH ₂ CR ₂₁ = CR ₂₂ R ₂₃ ,-(CH ₂ ) nO-CO-CR ₂₁ = CR ₂₂ R ₂₃ and — (CH ₂ CH ₂ O) ₂ —X (R _{21 to} R ₂₃ are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, an alkoxy group, An aryloxy group, R ₂₁ and R ₂₂ or R ₂₃ may combine with each other to form a ring, n is an integer of 1 to 10, and X is a dicyclopentadienyl residue) Can be mentioned. Specific examples of R of the ester residue include —CH ₂ CH═CH ₂ (corresponding to an allyl (meth) acrylate polymer described in JP-A No. 64-17047), —CH ₂ CH ₂ O—CH ₂ CH _{= CH 2, -CH 2 CH 2} OCOCH = CH 2, -CH 2 CH 2 OCOC (CH 3) = CH 2, -CH 2 C (CH 3) = CH 2, -CH 2 CH = CH-C 6 H ₅ , -CH ₂ CH ₂ OCOCH = CH-C ₆ H ₅ , -CH ₂ CH ₂ -NHCOO-CH ₂ CH = CH ₂ and -CH ₂ CH ₂ OX (X is dicyclopentadienyl residue) It is. Specific examples of R of the amide residue include —CH ₂ CH═CH ₂ , —CH ₂ CH ₂ —Y (Y is a 1-cyclohexenyl residue) and —CH ₂ CH ₂ —OCO—CH═CH ₂ , -CH ₂ CH ₂ -OCO-C (CH ₃ ) = CH ₂ is included.

  In the dispersant having an ethylenically unsaturated group, a free radical (a polymerization initiation radical or a growth radical of a polymerization process of a polymerizable compound) is added to the unsaturated bond group, and the polymer compound is directly or between molecules. Addition polymerization is carried out through the polymerization chain, and a crosslink is formed between the molecules to cure. Alternatively, atoms in the molecule (for example, hydrogen atoms on carbon atoms adjacent to the unsaturated bond group) are extracted by free radicals to form polymer radicals that are bonded together to form a bridge between the molecules. Harden.

The cross-linkable or polymerizable functional group-containing unit may constitute all repeating units other than the anionic group-containing repeating unit, preferably 5 to 50 mol% of all cross-linked or repeating units, particularly Preferably it is 5-30 mol%.
A preferable dispersant may be a copolymer with an appropriate monomer other than a monomer having a crosslinking or polymerizable functional group or an anionic group. Although it does not specifically limit regarding a copolymerization component, It selects from various viewpoints, such as dispersion stability, compatibility with another monomer component, and the intensity | strength of a formed film. Preferable examples include methyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, styrene and the like.
The form of the preferable dispersant is not particularly limited, but is preferably a block copolymer or a random copolymer, and particularly preferably a random copolymer from the viewpoint of cost and ease of synthesis.

  Specific examples of the dispersant preferably used in the present invention are shown below, but the dispersant is not limited to these in the present invention. Unless otherwise specified, it represents a random copolymer.

  The amount of the dispersant used relative to the inorganic fine particles is preferably in the range of 1 to 50% by mass, more preferably in the range of 5 to 30% by mass, and most preferably 5 to 20% by mass. Two or more dispersants may be used in combination.

<Dispersion medium>
As the dispersion medium, a liquid having a boiling point of 60 to 170 ° C. is preferably used. Examples of dispersion media include water, alcohol (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ester (eg, methyl acetate, ethyl acetate, Propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene chloride, chloroform, carbon tetrachloride), aromatic Hydrocarbon (eg, benzene, toluene, xylene), amide (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ether (eg, diethyl ether, dioxane, tetrahydrofuran), ether alcohol (eg, 1-methyl) Carboxymethyl-2-propanol) are included. Toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol are preferred.
Particularly preferred dispersion media are methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and toluene.

<Binder>
The high refractive index layer is preferably formed in the dispersion liquid in which the inorganic fine particles are dispersed in the dispersion medium as described above, preferably a binder precursor necessary for matrix formation (the binder precursor of the antiglare hard coat layer described above). The same), a photopolymerization initiator or the like to form a coating composition for forming a high refractive index layer, and a coating composition for forming a high refractive index layer on a transparent support, It is preferably formed by curing by a crosslinking reaction or a polymerization reaction (for example, a polyfunctional monomer or polyfunctional oligomer).

Further, it is preferable to cause the binder of the high refractive index layer to undergo a crosslinking reaction or a polymerization reaction with the dispersant simultaneously with or after the application of the layer.
The binder of the high refractive index layer thus prepared is, for example, the above-mentioned preferred dispersant and an ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer cross-linked or polymerized, and the binder is anionic. The base is incorporated. Furthermore, the binder of the high refractive index layer has a function in which the anionic group maintains the dispersed state of the inorganic fine particles, and the cross-linked or polymerized structure imparts a film forming ability to the binder to contain the inorganic fine particles. Improves physical strength, chemical resistance, and weather resistance.

It is preferable to use a photopolymerization initiator for the polymerization reaction of the photopolymerizable polyfunctional monomer. As the photopolymerization initiator, a photoradical polymerization initiator and a photocationic polymerization initiator are preferable, and a photoradical polymerization initiator is particularly preferable.
As the radical photopolymerization initiator, the same antiglare hard coat layer as described above can be used.

In the high refractive index layer, the binder preferably further has a silanol group. When the binder further has a silanol group, the physical strength, chemical resistance, and weather resistance of the high refractive index layer are further improved.
The silanol group is, for example, a silane coupling agent represented by the general formula A having a crosslinkable or polymerizable functional group, a partial hydrolyzate thereof, or a condensate thereof in the above coating composition for forming a high refractive index layer. The coating composition is applied onto a transparent support, and the above dispersant, polyfunctional monomer or polyfunctional oligomer, the silane coupling agent represented by the general formula A, a partial hydrolyzate thereof, or a condensation thereof The product can be introduced into the binder by crosslinking reaction or polymerization reaction.

In the high refractive index layer, the binder preferably has an amino group or a quaternary ammonium group.
For the binder of the high refractive index layer having an amino group or quaternary ammonium group, for example, a monomer having a crosslinkable or polymerizable functional group and an amino group or quaternary ammonium group is added to the coating composition for forming the above high refractive index layer. And it can form by apply | coating a coating composition on a transparent support body, carrying out a crosslinking reaction or a polymerization reaction with said dispersing agent, a polyfunctional monomer, or a polyfunctional oligomer.

  A monomer having an amino group or a quaternary ammonium group functions as a dispersion aid for inorganic fine particles in the coating composition. Furthermore, after coating, a dispersant, a polyfunctional monomer or a polyfunctional oligomer is crosslinked or polymerized to form a binder, thereby maintaining good dispersibility of the inorganic fine particles in the high refractive index layer, physical strength, resistance A high refractive index layer excellent in chemical properties and weather resistance can be produced.

Preferred monomers having an amino group or quaternary ammonium group include N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, hydroxypropyltrimethylammonium chloride (meth) acrylate, dimethyl And allyl ammonium chloride.
It is preferable that the usage-amount with respect to the dispersing agent of the monomer which has an amino group or a quaternary ammonium group is 1-40 mass%, More preferably, it is 3-30 mass%, Most preferably, it is 3-20 mass%. If the binder is formed by crosslinking or polymerization reaction simultaneously with or after the application of the high refractive index layer, these monomers can be effectively functioned before the application of the high refractive index layer.

  The crosslinked or polymerized binder has a structure in which the main chain of the polymer is crosslinked or polymerized. Examples of the polymer main chain include polyolefin (saturated hydrocarbon), polyether, polyurea, polyurethane, polyester, polyamine, polyamide and melamine resin. A polyolefin main chain, a polyether main chain and a polyurea main chain are preferable, a polyolefin main chain and a polyether main chain are more preferable, and a polyolefin main chain is most preferable.

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

The anionic group is preferably bonded to the main chain as a side chain of the binder via a linking group.
The linking group that binds the anionic group and the main chain of the binder is preferably a divalent group selected from —CO—, —O—, an alkylene group, an arylene group, and combinations thereof. The crosslinked or polymerized structure chemically bonds (preferably covalently bonds) two or more main chains. In the crosslinked or polymerized structure, it is preferable to covalently bond three or more main chains. The crosslinked or polymerized structure is preferably composed of a divalent or higher valent group selected from —CO—, —O—, —S—, a nitrogen atom, a phosphorus atom, an aliphatic residue, an aromatic residue, and combinations thereof. .

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

The repeating unit of the binder may have both an anionic group and a crosslinked or polymerized structure. The binder may contain other repeating units (repeating units having neither an anionic group nor a crosslinked or polymerized structure).
Other repeating units are preferably repeating units having a silanol group, an amino group or a quaternary ammonium group.

  In the repeating unit having a silanol group, the silanol group is directly bonded to the main chain of the binder or is bonded to the main chain via a linking group. The silanol group is preferably bonded to the main chain as a side chain via a linking group. The linking group that connects the silanol group and the main chain of the binder is preferably a divalent group selected from —CO—, —O—, an alkylene group, an arylene group, and combinations thereof. When the binder contains a repeating unit having a silanol group, the ratio is preferably 2 to 98 mol%, more preferably 4 to 96 mol%, and most preferably 6 to 94 mol%.

  In the repeating unit having an amino group or a quaternary ammonium group, the amino group or quaternary ammonium group is directly bonded to the main chain of the binder or bonded to the main chain via a linking group. The amino group or quaternary ammonium group is preferably bonded to the main chain as a side chain via a linking group. The amino group or quaternary ammonium group is preferably a secondary amino group, a tertiary amino group or a quaternary ammonium group, more preferably a tertiary amino group or a quaternary ammonium group. The group bonded to the nitrogen atom of the secondary amino group, tertiary amino group or quaternary ammonium group is preferably an alkyl group, preferably an alkyl group having 1 to 12 carbon atoms, Is more preferably an alkyl group of 1 to 6. The counter ion of the quaternary ammonium group is preferably a halide ion. The linking group that connects the amino group or the quaternary ammonium group to the main chain of the binder is a divalent group selected from —CO—, —NH—, —O—, an alkylene group, an arylene group, and combinations thereof. Preferably there is. When the binder includes a repeating unit having an amino group or a quaternary ammonium group, the ratio is preferably 0.1 to 32 mol%, more preferably 0.5 to 30 mol%, and more preferably 1 to 28 mol. % Is most preferred.

In addition, even if the silanol group, amino group, and quaternary ammonium group are contained in a repeating unit having an anionic group or a repeating unit having a crosslinked or polymerized structure, the same effect can be obtained.
The binder that has been crosslinked or polymerized is preferably formed by coating a coating composition for forming a high refractive index layer on a transparent support, and by crosslinking or polymerization reaction simultaneously with or after coating.

  The high refractive index layer contains an ionizing radiation curable compound containing an aromatic ring, an ionizing radiation curable compound containing a halogenated element other than fluorine (for example, Br, I, Cl, etc.), and atoms such as S, N, P, etc. A binder obtained by a crosslinking or polymerization reaction such as an ionizing radiation curable compound can also be preferably used.

  The binder of the high refractive index layer is preferably added in an amount of 5 to 80% by mass based on the solid content of the coating composition of the layer.

<Method for forming high refractive index layer>
The inorganic fine particles mainly composed of titanium dioxide used for the high refractive index layer are used for forming the high refractive index layer in a dispersion state. The inorganic fine particles are dispersed in a dispersion medium in the presence of a dispersant.
The inorganic fine particles can be dispersed using a disperser. Examples of dispersers include sand grinder mills (eg, pinned bead mills), high speed impeller mills, pebble mills, roller mills, attritors and colloid mills. A sand grinder mill and a high-speed impeller mill are particularly preferred. Further, preliminary dispersion processing may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder.

The inorganic fine particles are preferably made as fine as possible in the dispersion medium, and the mass average diameter is 1 to 200 nm. Preferably it is 5-150 nm, More preferably, it is 10-100 nm, Most preferably, it is 10-80 nm.
By refining the inorganic fine particles to 200 nm or less, a high refractive index layer that does not impair the transparency can be formed.

When the low refractive index layer is provided on the high refractive index layer, the refractive index of the high refractive index layer is preferably higher than the refractive index of the transparent support.
In order to construct an antireflection film by constructing a low refractive index layer on a high refractive index layer, the refractive index of the high refractive index layer is preferably 1.55 to 2.40, more preferably It is 1.60 to 2.20, more preferably 1.65 to 2.10, and most preferably 1.80 to 2.00.

In addition to the above components (inorganic fine particles, polymerization initiators, photosensitizers, etc.), the high refractive index layer includes resins, surfactants, antistatic agents, coupling agents, thickeners, anti-coloring agents, and coloring. Agents (pigments, dyes), antifoaming agents, leveling agents, flame retardants, UV absorbers, infrared absorbers, adhesion-imparting agents, polymerization inhibitors, antioxidants, surface modifiers, conductive metal particles, etc. It can also be added.
The film thickness of the high refractive index layer can be appropriately designed depending on the application. When using a high refractive index layer as an optical interference layer described later, the thickness is preferably 30 to 200 nm, more preferably 50 to 170 nm, and particularly preferably 60 to 150 nm.

In the high refractive index layer, the inorganic fine particles are dispersed as described above, and then the dispersion is applied onto a support or the other, and a crosslinking reaction or a polymerization reaction of the active radiation curable compound is performed as necessary. In addition, about the dispersion for forming a high refractive index layer, the filtration process demonstrated above may be performed and it is not necessary to perform it.
The crosslinking reaction or polymerization reaction of the ionizing radiation curable compound is preferably carried out in an atmosphere having an oxygen concentration of 10% by volume or less. This is not limited to the formation of the high refractive index layer, but is common to the antiglare hard coat layer and the light diffusing layer.
By forming the high refractive index layer in an atmosphere having an oxygen concentration of 10% by volume or less, the physical strength, chemical resistance, and weather resistance of the high refractive index layer, and further, the high refractive index layer and the high refractive index layer are adjacent to each other. Adhesion with the layer can be improved.
Preferably, it is formed by a crosslinking reaction or polymerization reaction of an ionizing radiation curable compound in an atmosphere having an oxygen concentration of 6% by volume or less, more preferably an oxygen concentration of 4% by volume or less, particularly preferably an oxygen concentration of 2 Volume% or less, most preferably 1 volume% or less.
As a method of reducing the oxygen concentration to 10% by volume or less, it is preferable to replace the atmosphere (nitrogen concentration of about 79% by volume, oxygen concentration of about 21% by volume) with another gas, particularly preferably replacement with nitrogen (nitrogen purge). It is to be.

The strength of the high refractive index layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400.
Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.
The haze of the high refractive index layer is preferably as low as possible when it does not contain particles that impart an antiglare function. It is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less.
The high refractive index layer is preferably constructed directly on the transparent support or via another layer.

(Low refractive index layer)
The refractive index of the low refractive index layer of the antireflection film is preferably 1.20 to 1.49, more preferably 1.30 to 1.44.
Hereinafter, each component used for the low refractive index layer will be described.
<Fluoropolymer>
The low refractive index layer of the antireflection film preferably contains a fluorine-containing polymer as a low refractive index binder. The fluoropolymer is preferably a fluoropolymer that is crosslinked by heat or ionizing radiation having a coefficient of dynamic friction of 0.03 to 0.15 and a contact angle with water of 90 to 120 °. The above-mentioned inorganic filler for improving the film strength can also be used for the low refractive index layer.

  Examples of the fluorine-containing polymer preferably used for the low refractive index layer include hydrolysis and dehydration condensates of perfluoroalkyl group-containing silane compounds (for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane). In addition, a fluorine-containing copolymer having a fluorine-containing monomer unit and a structural unit for imparting crosslinking reactivity as structural components may be mentioned.

  Specific examples of the fluorine-containing monomer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, perfluorooctylethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole. Etc.), partially (meth) acrylic acid or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemical), M-2020 (manufactured by Daikin), etc.), fully or partially fluorinated vinyl ethers, etc. However, perfluoroolefins are preferred, and hexafluoropropylene is particularly preferred from the viewpoints of refractive index, solubility, transparency, availability, and the like.

  As structural units for imparting crosslinking reactivity, structural units obtained by polymerization of monomers having a self-crosslinkable functional group in advance in the molecule such as glycidyl (meth) acrylate and glycidyl vinyl ether, carboxyl groups, hydroxy groups, amino groups , Obtained by polymerization of a monomer having a sulfo group or the like (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid, etc.) And a structural unit obtained by introducing a crosslinking reactive group such as a (meth) acryloyl group into these structural units by a polymer reaction (for example, it can be introduced by a technique such as allowing acrylic acid chloride to act on a hydroxy group) And the like.

  In addition to the above-mentioned fluorine-containing monomer units and structural units for imparting crosslinking reactivity, monomers not containing fluorine atoms can be copolymerized as appropriate from the viewpoints of solubility in solvents and film transparency. There are no particular limitations on the monomer units that can be used in combination. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid 2) -Ethylhexyl), methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyltoluene, α-methylstyrene, etc.), vinyl ethers (methyl) Vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate etc.), acrylamides (N-tertbutylacrylamide, N-silane) B hexyl acrylamide), methacrylamides, and acrylonitrile derivatives.

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

  A particularly useful fluorine-containing polymer used in the low refractive index layer is a random copolymer of perfluoroolefin and vinyl ethers or vinyl esters. In particular, it preferably has a group capable of undergoing a crosslinking reaction alone (a radical reactive group such as a (meth) acryloyl group, a ring-opening polymerizable group such as an epoxy group or an oxetanyl group). These cross-linking reactive group-containing polymer units preferably occupy 5 to 70 mol%, particularly preferably 30 to 60 mol% of the total polymer units of the polymer.

  As a preferable form of the copolymer used for the low refractive index layer, one having the following general formula 1 can be mentioned.

In General Formula 1, L represents a linking group having 1 to 10 carbon atoms, more preferably a linking group having 1 to 6 carbon atoms, particularly preferably a linking group having 2 to 4 carbon atoms, It may have a branched structure, may have a ring structure, and may have a heteroatom selected from O, N, and S.
Preferred examples include *-(CH ₂ ) ₂ -O-**, *-(CH ₂ ) ₂ -NH-**, *-(CH ₂ ) ₄ -O-**, *-(CH ₂ ) ₆ -O-**, *-(CH ₂ ) ₂ -O- (CH ₂ ) ₂ -O-**, * -CONH- (CH ₂ ) ₃ -O-**, * -CH ₂ CH (OH ) CH ₂ -O-**, * -CH ₂ CH ₂ OCONH (CH ₂ ) ₃ -O-** (* represents the linking site on the polymer main chain side, ** is the linking on the (meth) acryloyl group side) Represents a part). m represents 0 or 1;

  In general formula 1, X represents a hydrogen atom or a methyl group. From the viewpoint of curing reactivity, a hydrogen atom is more preferable.

  In the general formula 1, A represents a repeating unit derived from an arbitrary vinyl monomer, and is not particularly limited as long as it is a constituent component of a monomer copolymerizable with hexafluoropropylene. Tg (contributes to film hardness), solubility in solvents, transparency, slipperiness, dust / antifouling properties, etc., can be selected as appropriate, depending on the purpose, depending on the single or multiple vinyl monomers It may be configured.

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

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

  As a particularly preferred form of the copolymer used for the low refractive index layer, the general formula 4 may be mentioned.

In general formula 4, X, x, and y have the same meaning as in general formula 1, and the preferred ranges are also the same.
n represents an integer of 2 ≦ n ≦ 10, preferably 2 ≦ n ≦ 6, and particularly preferably 2 ≦ n ≦ 4.
B represents a repeating unit derived from an arbitrary vinyl monomer, and may be composed of a single composition or a plurality of compositions. As an example, what was demonstrated as an example of A in the said General formula 1 is applicable.
z1 and z2 represent mol% of each repeating unit, and represent values satisfying 0 ≦ z1 ≦ 65 and 0 ≦ z2 ≦ 65. It is preferable that 0 ≦ z1 ≦ 30 and 0 ≦ z2 ≦ 10 respectively, and it is particularly preferable that 0 ≦ z1 ≦ 10 and 0 ≦ z2 ≦ 5.

  For the copolymer represented by the general formula 1 or 4, for example, a (meth) acryloyl group is introduced into a copolymer comprising a hexafluoropropylene component and a hydroxyalkyl vinyl ether component by any one of the methods described above. Can be synthesized.

  Although the preferable example of the copolymer useful by this invention is shown below, this invention is not limited to these.

  The copolymer used for the low refractive index layer is synthesized by synthesizing precursors such as a hydroxyl group-containing polymer by various polymerization methods such as solution polymerization, precipitation polymerization, suspension polymerization, precipitation polymerization, bulk polymerization, and emulsion polymerization. Then, it can be carried out by introducing a (meth) acryloyl group by the polymer reaction. The polymerization reaction can be performed by a known operation such as a batch system, a semi-continuous system, or a continuous system.

  The polymerization initiation method includes a method using a radical initiator, a method of irradiating light or radiation, and the like. These polymerization methods and polymerization initiation methods are, for example, the revised version of Tsuruta Junji “Polymer Synthesis Method” (published by Nikkan Kogyo Shimbun, 1971), Takatsu Otsu, Masato Kinoshita, “Experimental Methods for Polymer Synthesis” It is described in pp. 47-154 published in 1972.

  Among the above polymerization methods, a solution polymerization method using a radical initiator is particularly preferable. Solvents used in the solution polymerization method include, for example, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, benzene, toluene, acetonitrile, A single organic solvent such as methylene chloride, chloroform, dichloroethane, methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol, or a mixture of two or more thereof may be used, or a mixed solvent with water may be used.

  The polymerization temperature needs to be set in relation to the molecular weight of the polymer to be produced, the type of initiator, etc., and can be from 0 ° C. or lower to 100 ° C. or higher, but it is preferable to carry out the polymerization in the range of 50 to 100 ° C.

The reaction pressure can be selected as appropriate, but it is usually 1-100 kg / cm ² , particularly about 1-30 kg / cm ² . The reaction time is about 5 to 30 hours.

  As the reprecipitation solvent for the obtained polymer, isopropanol, hexane, methanol and the like are preferable.

  The fluorine-containing polymer of the low refractive index layer is preferably added in an amount of 20 to 95% by mass based on the solid content of the coating composition of the layer.

<Inorganic fine particles>
Inorganic fine particles can be added to the low refractive index layer.
The amount of the inorganic fine particles is ^{preferably 1mg / m 2 ~100mg / m 2} , more preferably ^{5mg / m 2 ~80mg / m 2} , more preferably from ^{10mg / m 2 ~60mg / m 2} . When the blending amount is in the above range, the scratch resistance is excellent, the occurrence of fine irregularities on the surface of the low refractive index layer is reduced, and the appearance such as black tightening and the integrated reflectance are improved.
Since the inorganic fine particles are contained in the low refractive index layer, it is desirable that the inorganic fine particles have a low refractive index. Examples thereof include fine particles of magnesium fluoride and silica. In particular, silica fine particles are preferable in terms of refractive index, dispersion stability, and cost.
The average particle diameter of the silica fine particles is preferably 30% to 150% of the thickness of the low refractive index layer, more preferably 35% to 80%, and still more preferably 40% to 60%. That is, when the thickness of the low refractive index layer is 100 nm, the particle diameter of the silica fine particles is preferably 30 nm to 150 nm, more preferably 35 nm to 80 nm, and still more preferably 40 nm to 60 nm.
If the particle size of the silica fine particles is too small, the effect of improving the scratch resistance is reduced. If it is too large, fine irregularities are formed on the surface of the low refractive index layer, and the appearance such as black tightening and the integrated reflectance are deteriorated. The silica fine particles may be either crystalline or amorphous, and may be monodispersed particles or aggregated particles as long as a predetermined particle size is satisfied. The shape is most preferably a spherical diameter, but there is no problem even if the shape is indefinite. Here, the average particle diameter of the inorganic fine particles can be measured by a Coulter counter, a light scattering particle diameter measuring device, observation with an electron microscope, or the like.

In order to further reduce the increase in the refractive index of the low refractive index layer, it is preferable to use hollow silica fine particles, and the hollow silica fine particles have a refractive index of 1.17 to 1.40, more preferably 1.17 to 1. .35, more preferably 1.17 to 1.30. The refractive index here represents the refractive index of the entire particle, and does not represent the refractive index of only the outer shell silica forming the hollow silica particles. At this time, when the radius of the cavity in the particle is a and the radius of the particle outer shell is b, the porosity x calculated from the following formula (VIII) is preferably 10 to 60%, more preferably 20 to 60. %, Most preferably 30-60%.

Formula (VIII): x = (4πa3 / 3) / (4πb3 / 3) × 100

If hollow silica particles are made to have a lower refractive index and a higher porosity, the thickness of the outer shell becomes thinner and the strength of the particles becomes weaker. From the viewpoint of scratch resistance, the low refractive index is less than 1.17. No rate particles are used.
The refractive index of these hollow silica particles can be measured with an Abbe refractometer (manufactured by Atago Co., Ltd.).

Further, at least one kind of silica fine particles having an average particle size of less than 25% of the thickness of the low refractive index layer (referred to as “small size particle size silica particles”) is used as silica fine particles having the above particle size (“large size particles”). It is preferably used in combination with “silica fine particles having a diameter”.
Since the fine silica particles having a small particle size can exist in the gaps between the fine silica particles having a large particle size, they can contribute as a retaining agent for the fine silica particles having a large particle size.
When the low refractive index layer is 100 nm, the average particle size of the silica fine particles having a small size is preferably from 1 nm to 20 nm, more preferably from 5 nm to 15 nm, and particularly preferably from 10 nm to 15 nm. Use of such silica fine particles is preferable in terms of raw material costs and a retaining agent effect.

Silica fine particles are treated with a physical surface treatment such as plasma discharge treatment or corona discharge treatment in order to stabilize dispersion in the dispersion or coating solution, or to increase the affinity and binding to the binder component. Chemical surface treatment with a surfactant, a coupling agent, or the like may be performed. The use of a coupling agent is particularly preferred. As the coupling agent, an alkoxy metal compound (eg, titanium coupling agent, silane coupling agent) is preferably used. Of these, silane coupling treatment is particularly effective.
The above coupling agent is used as a surface treatment agent for the inorganic filler of the low refractive index layer in advance for surface treatment prior to the preparation of the layer coating solution. It is preferable to contain in a layer.
The silica fine particles are preferably dispersed in the medium in advance before the surface treatment in order to reduce the load of the surface treatment.
What has been described above for silica fine particles also applies to other inorganic fine particles.

<Organosilane compound>
At least one of the functional layers constituting the antireflective film includes at least one component of an organosilane compound, a hydrolyzate thereof and a partial condensate thereof, a so-called sol component (hereinafter referred to as “sol component”). It is preferable from the viewpoint of scratch resistance. In particular, the low refractive index layer preferably contains a sol component in order to achieve both antireflection ability and scratch resistance, and the antiglare hard coat layer and the hard coat layer preferably also contain a sol component. This sol component is condensed by a drying and heating process after coating the coating solution to form a cured product, which becomes a binder for the layer. Moreover, when this hardened | cured material has a polymerizable unsaturated bond, the binder which has a three-dimensional structure is formed by irradiation of actinic light.
The organosilane compound is preferably one represented by the following general formula 5.
Formula _{^{5: (R 10) m -Si}} (X) 4-m

In the general formula 5, R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. As an alkyl group, a C1-C30 alkyl group is preferable, More preferably, it is C1-C16, Most preferably, it is a C1-C6 thing. Specific examples of the alkyl group include methyl, ethyl, propyl, isopropyl, hexyl, decyl, hexadecyl and the like. Examples of the aryl group include phenyl and naphthyl, and a phenyl group is preferable.
X represents a hydroxyl group or a hydrolyzable group, for example, an alkoxy group (preferably an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group or an ethoxy group), a halogen atom (for example, Cl, Br, I or the like). ), And R ² COO (R ² is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, such as CH ₃ COO, C ₂ H ₅ COO, etc.), preferably An alkoxy group, particularly preferably a methoxy group or an ethoxy group.
m represents an integer of 1 to 3, preferably 1 or 2, and particularly preferably 1.

When R ¹⁰ or X there are a plurality, a plurality of R ¹⁰ or X groups may be different, even the same, respectively.
The substituent contained in R ¹⁰ is not particularly limited, but a halogen atom (fluorine, chlorine, bromine, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl, ethyl, i-propyl, propyl, t-butyl etc.), aryl groups (phenyl, naphthyl etc.), aromatic heterocyclic groups (furyl, pyrazolyl, pyridyl etc.), alkoxy groups (methoxy, ethoxy, i-propoxy, hexyloxy etc.), aryloxy (phenoxy etc.) ), Alkylthio groups (methylthio, ethylthio, etc.), arylthio groups (phenylthio, etc.), alkenyl groups (vinyl, 1-propenyl, etc.), acyloxy groups (acetoxy, acryloyloxy, methacryloyloxy, etc.), alkoxycarbonyl groups (methoxycarbonyl, ethoxy) Carbonyl), arylo Xyloxycarbonyl group (phenoxycarbonyl, etc.), carbamoyl group (carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl, etc.), acylamino group (acetylamino, benzoylamino, acrylamino, methacryl) Amino) and the like, and these substituents may be further substituted.

When there are a plurality of R ¹⁰ , at least one is preferably a substituted alkyl group or a substituted aryl group, and among them, an organosilane compound having a vinyl polymerizable substituent represented by the following general formula 6 is preferable.

In the general formula 6, R ¹ represents a hydrogen atom, a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom, or a chlorine atom. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group. A hydrogen atom, a methyl group, a methoxy group, a methoxycarbonyl group, a cyano group, a fluorine atom and a chlorine atom are preferred, a hydrogen atom, a methyl group, a methoxycarbonyl group, a fluorine atom and a chlorine atom are more preferred, and a hydrogen atom and a methyl group Is particularly preferred.
Y represents a single bond or * -COO-**, * -CONH-** or * -O-**, a single bond, * -C
OO-** and * -CONH-** are preferred, single bond and * -COO-** are more preferred, *-
COO-** is particularly preferred. * Represents a position bonded to ═C (R ¹ ) —, and ** represents a position bonded to L.

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

n represents 0 or 1. When there are a plurality of Xs, the plurality of Xs may be the same or different. n is preferably 0.
R10 has the same meaning as in formula 5, preferably a substituted or unsubstituted alkyl group or an unsubstituted aryl group, and more preferably an unsubstituted alkyl group or an unsubstituted aryl group.
X has the same meaning as in formula 5, preferably a halogen atom, a hydroxyl group, or an unsubstituted alkoxy group, more preferably a chlorine atom, a hydroxyl group, or an unsubstituted alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, or 1 to 3 carbon atoms. Are more preferable, and a methoxy group is particularly preferable.

  Two or more of the compounds represented by general formulas 5 and 6 may be used in combination. Specific examples of the compounds represented by general formulas 5 and 6 are shown below, but are not limited thereto.

  Of these, (M-1), (M-2), and (M-5) are particularly preferable.

The hydrolyzate and / or partial condensate of the organosilane compound will be described in detail.
The hydrolysis reaction of organosilane and the subsequent condensation reaction are generally carried out in the presence of a catalyst. Catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as oxalic acid, acetic acid, formic acid, methanesulfonic acid and toluenesulfonic acid; inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine, Examples thereof include organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium; metal chelate compounds having a metal such as Zr, Ti or Al as a central metal. Among inorganic acids, hydrochloric acid, sulfuric acid, and organic acids preferably have an acid dissociation constant (pKa value (25 ° C.)) of 4.5 or less in water, and an acid dissociation constant in hydrochloric acid, sulfuric acid, or water of 3.0 or less. More preferred is an organic acid, hydrochloric acid, sulfuric acid, an organic acid having an acid dissociation constant of 2.5 or less in water is more preferred, an organic acid having an acid dissociation constant in water of 2.5 or less is more preferred, and methanesulfonic acid Further, oxalic acid, phthalic acid, and malonic acid are more preferable, and oxalic acid is particularly preferable.

The organosilane hydrolysis / condensation reaction can be carried out in the absence of a solvent or in a solvent, but an organic solvent is preferably used in order to mix the components uniformly. For example, alcohols, aromatic hydrocarbons, ethers, Ketones and esters are preferred.
The solvent preferably dissolves the organosilane and the catalyst. In addition, it is preferable in the process that an organic solvent is used as a coating solution or a part of the coating solution, and those that do not impair the solubility or dispersibility when mixed with other materials such as a fluorine-containing polymer are preferable.

Among these, examples of alcohols include monohydric alcohols and dihydric alcohols, and among these, monohydric alcohols are preferably saturated aliphatic alcohols having 1 to 8 carbon atoms.
Specific examples of these alcohols include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol. Examples thereof include monobutyl ether and ethylene glycol monoethyl ether acetate.

Specific examples of aromatic hydrocarbons include benzene, toluene, xylene and the like. Specific examples of ethers include tetrahydrofuran and dioxane. Specific examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, Specific examples of esters such as diisobutyl ketone include ethyl acetate, propyl acetate, butyl acetate, and propylene carbonate.
These organic solvents can be used alone or in combination of two or more. The concentration of the solid content in the reaction is not particularly limited, but is usually in the range of 1% to 90%, preferably in the range of 20% to 70%.

0.3 to 2 mol, preferably 0.5 to 1 mol of water is added to 1 mol of the hydrolyzable group of the organosilane, in the presence or absence of the above solvent, and in the presence of a catalyst. It is carried out by stirring at 25 to 100 ° C.
In the present invention, the alcohol represented by the general formula R ³ OH (wherein R ³ represents an alkyl group having 1 to 10 carbon atoms) and the general formula R ⁴ COCH ₂ COR ⁵ (wherein R ⁴ represents the number of carbon atoms) 1 to 10 alkyl groups, R ⁵ represents an alkyl group having 1 to 10 carbon atoms or a compound represented by an alkoxy group having 1 to 10 carbon atoms) and selected from Zr, Ti or Al. It is preferable to perform the hydrolysis by stirring at 25 to 100 ° C. in the presence of at least one metal chelate compound having a metal as a central metal.

Metal chelate compounds (wherein, ^{R 3} represents an alkyl group having 1 to 10 carbon atoms) Formula ^R 3 OH alcohol and ^R 4 COCH ₂ COR ⁵ (wherein represented by, ^{R 4} is C 1 -C To 10 alkyl groups, R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms), and is selected from Zr, Ti, and Al. Any metal having a metal as a central metal can be suitably used without particular limitation. Within this category, two or more metal chelate compounds may be used in combination. The metal chelate compound used in the present invention has a general formula of Zr (OR ³ ) _p1 (R ⁴ COCHCOR ⁵ ) _p2 , Ti (OR ³ ) _q1 (R ⁴ COCHCOR ⁵ ) _q2 , and Al (OR ³ ) _r1 (R ⁴ Those selected from the group of compounds represented by COCHCOR ⁵ ) _r2 are preferred, and serve to promote the condensation reaction of the hydrolyzate and / or partial condensate of the organosilane compound.
R ³ and R ⁴ in the metal chelate compound may be the same or different and each is an alkyl group having 1 to 10 carbon atoms, specifically, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, sec -Butyl group, t-butyl group, n-pentyl group, phenyl group and the like. R5 is the same alkyl group having 1 to 10 carbon atoms as described above, or an alkoxy group having 1 to 10 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and an n-butoxy group. , Sec-butoxy group, t-butoxy group and the like. Moreover, p1, p2, q1, q2, r1, and r2 in the metal chelate compound represent integers determined so as to be p1 + p2 = 4, q1 + q2 = 4, and r1 + r2 = 3, respectively.

Specific examples of these metal chelate compounds include tri-n-butoxyethylacetoacetate zirconium, di-n-butoxybis (ethylacetoacetate) zirconium, n-butoxytris (ethylacetoacetate) zirconium, tetrakis (n-propylacetate). Zirconium chelate compounds such as acetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; diisopropoxy bis (ethylacetoacetate) titanium, diisopropoxy bis (acetylacetate) titanium, diiso Titanium chelate compounds such as propoxy bis (acetylacetone) titanium; diisopropoxyethyl acetoacetate aluminum, diisopropyl Poxyacetylacetonate aluminum, isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonate) aluminum, monoacetylacetonate bis (ethyl) An aluminum chelate compound such as acetoacetate) aluminum.
Among these metal chelate compounds, tri-n-butoxyethyl acetoacetate zirconium, diisopropoxybis (acetylacetonate) titanium, diisopropoxyethyl acetoacetate aluminum, and tris (ethyl acetoacetate) aluminum are preferable. These metal chelate compounds can be used individually by 1 type or in mixture of 2 or more types. Moreover, the partial hydrolyzate of these metal chelate compounds can also be used.

  The metal chelate compound is preferably used in a proportion of 0.01 to 50% by mass, more preferably 0.1 to 50% by mass, and still more preferably 0.5 to 10% by mass with respect to the organosilane compound. If it is less than 0.01% by mass, the condensation reaction of the organosilane compound is slow, and the durability of the coating film may be deteriorated. On the other hand, if it exceeds 50% by mass, the hydrolyzate and / or partial condensation of the organosilane compound may occur. The storage stability of the composition containing the product and the metal chelate compound may be deteriorated, which is not preferable.

  It is preferable that a β-diketone compound and / or a β-ketoester compound is added to the coating liquid for the hard coat layer to the low refractive index layer in addition to the composition containing the sol component and the metal chelate compound. This will be further described below.

As the β-diketone compound and / or β-ketoester compound, a compound represented by the general formula R ⁴ COCH ₂ COR ⁵ is preferable, which is used as a stability improver for the coating liquid of the hard coat layer to the low refractive index layer. It works. That is, by coordinating with a metal atom in the metal chelate compound (zirconium, titanium and / or aluminum compound), the condensation reaction of the hydrolyzate and / or partial condensate of the organosilane compound by these metal chelate compounds is performed. It is considered that the promoting action is suppressed and the storage stability of the resulting composition is improved. R ⁴ and R ⁵ constituting the β- diketone compound and / or β- ketoester compound are the same as R ⁴ and R ⁵ constituting the metal chelate compound.

  Specific examples of the β-diketone compound and / or β-ketoester compound include acetylacetone, methyl acetoacetate, ethyl acetoacetate, acetoacetate-n-propyl, acetoacetate-i-propyl, acetoacetate-n-butyl, acetoacetate. Acetic acid-sec-butyl, acetoacetic acid-t-butyl, 2,4-hexane-dione, 2,4-heptane-dione, 3,5-heptane-dione, 2,4-octane-dione, 2,4-nonane -Dione, 5-methyl-hexane-dione and the like can be mentioned. Of these, ethyl acetoacetate and acetylacetone are preferred, and acetylacetone is particularly preferred. These β-diketone compounds and / or β-ketoester compounds may be used alone or in combination of two or more. In the present invention, the β-diketone compound and / or β-ketoester compound is preferably used in an amount of 2 mol or more, more preferably 3 to 20 mol, per 1 mol of the metal chelate compound. If it is less than 2 mol, the storage stability of the resulting composition may be inferior, which is not preferable.

The content of the hydrolyzate and / or partial condensate of the organosilane compound is preferably small for a surface layer that is a relatively thin film and large for a lower layer that is a thick film. In the case of a surface layer such as a low refractive index layer, 0.1 to 50% by mass of the total solid content of the containing layer (addition layer) is preferable, 0.5 to 20% by mass is more preferable, and 1 to 10% by mass is preferable. Most preferred.
The amount added to the layers other than the low refractive index layer is preferably 0.001 to 50 mass%, more preferably 0.01 to 20 mass%, and more preferably 0.05 to 10 mass% of the total solid content of the containing layer (addition layer). More preferably, it is 0.1 to 5% by mass.
In forming the hard coat layer or the low refractive index layer, first, a composition containing the hydrolyzate and / or partial condensate of the organosilane compound and the metal chelate compound is prepared, and a β-diketone compound and It is preferable to coat after adding the liquid to which the β-ketoester compound is added to at least one coating liquid of the hard coat layer or the low refractive index layer.

  In the low refractive index layer, the amount of the organosilane sol component used with respect to the fluorine-containing polymer is preferably from 5 to 100% by mass, and preferably from 5 to 40% by mass considering the effect, refractive index, film shape / surface shape, etc. % Is more preferable, 8-35 mass% is further more preferable, and 10-30 mass% is especially preferable.

<Additives>
In the present invention, for the purpose of suppressing aggregation and sedimentation of the inorganic filler, it is also preferable to use a dispersion stabilizer in combination with the coating solution for forming each layer. As the dispersion stabilizer, polyvinyl alcohol, polyvinyl pyrrolidone, cellulose derivative, polyamide, phosphate ester, polyether, surfactant, silane coupling agent, titanium coupling agent and the like can be used. In particular, the above-mentioned silane coupling agent is preferable because the film after curing is strong.

  The low refractive index layer-forming composition is usually prepared in the form of a liquid, using the copolymer as a preferred constituent, and if necessary, various additives and a radical polymerization initiator dissolved in an appropriate solvent. At this time, the concentration of the solid content is appropriately selected according to the use, but is generally about 0.01 to 60% by mass, preferably 0.5 to 50% by mass, particularly preferably 1% to 20% by mass. %.

  As described above, it is not always advantageous to add an additive such as a curing agent from the viewpoint of film hardness of the low refractive index layer, but from the viewpoint of interfacial adhesion with the high refractive index layer, etc. ) A curing agent such as an acrylate compound, polyfunctional epoxy compound, polyisocyanate compound, aminoplast, polybasic acid or anhydride thereof, or a small amount of inorganic fine particles such as silica can be added. When adding these, it is preferable that it is the range of 0-30 mass% with respect to the total solid of a low refractive index layer membrane | film | coat, It is more preferable that it is the range of 0-20 mass%, 0-10 mass % Range is particularly preferred.

  For the purpose of imparting properties such as antifouling properties, water resistance, chemical resistance, and slipping properties, known silicone-based or fluorine-based antifouling agents, slipping agents, and the like can be appropriately added. When these additives are added, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the low refractive index layer, more preferably in the range of 0.05 to 10% by mass. Particularly preferred is 0.1 to 5% by mass.

  Preferable examples of the silicone compound include those having a substituent at the terminal and / or side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units. The compound chain containing dimethylsilyloxy as a repeating unit may contain a structural unit other than dimethylsilyloxy. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, fluoroalkyl group, polyoxyalkylene group, carboxyl group, amino group and the like. It is done. Although there is no restriction | limiting in particular in molecular weight, It is preferable that it is 100,000 or less, It is especially preferable that it is 50,000 or less, It is most preferable that it is 3000-30000. Although there is no restriction | limiting in particular in silicone atom content of a silicone type compound, it is preferable that it is 18.0 mass% or more, it is especially preferable that it is 25.0-37.8 mass%, and 30.0-37.0. Most preferably, it is mass%. Examples of preferable silicone compounds include X-22-174DX, X-22-2426, X-22-164B, X22-164C, X-22-170DX, X-22-176D, X, manufactured by Shin-Etsu Chemical Co., Ltd. -22-1821 (named above), Chisso Corporation, FM-0725, FM-7725, DMS-U22, RMS-033, RMS-083, UMS-182 (named above), etc. It is not limited to.

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

  It is preferable that the fluorine-based compound further has a substituent that contributes to bond formation or compatibility with the low refractive index layer film. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like. The fluorine-based compound may be a copolymer or a copolymer oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferred fluorine-based compounds include Daikin Chemical Industries, R-2020, M-2020, R-3833, M-3833 (named above), Dainippon Ink, Megafac F-171. , F-172, F-179A, Defender MCF-300 (named above), but not limited thereto.

  For the purpose of imparting properties such as dust resistance and antistatic properties, a known cationic surfactant or a dustproof agent such as a polyoxyalkylene compound, an antistatic agent, or the like can be appropriately added. These dustproofing agent and antistatic agent may contain the structural unit as a part of the function in the above-mentioned silicone compound or fluorine compound. When these are added as additives, it is preferably added in the range of 0.01 to 20% by mass, more preferably in the range of 0.05 to 10% by mass of the total solid content of the low refractive index layer. Particularly preferred is 0.1 to 5% by mass. Examples of preferable compounds include, but are not limited to, Dainippon Ink Co., Ltd., MegaFuck F-150 (trade name), Toray Dow Corning Co., Ltd., SH-3748 (trade name), and the like. Do not mean.

  The low refractive index layer is formed by applying a coating solution containing the above-mentioned fluorine-containing polymer, inorganic fine particles, organosilane compound, etc. on a support or another layer, and crosslinking or polymerizing an actinic radiation curable resin as necessary. It can be produced by carrying out a reaction. In addition, about the coating liquid for low refractive index layers, the filtration process demonstrated above may be performed and it is not necessary to perform it.

(Transparent support)
A plastic film is preferably used as the transparent support for the optical film and the antireflection film. Examples of the polymer that forms the plastic film include cellulose esters (eg, triacetyl cellulose, diacetyl cellulose, typically Fuji Photo FUJITAC TD80U, TDY80U, etc.), polyamides, polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene naphthalate). Phthalate), polystyrene, polyolefin, norbornene-based resin (Arton: trade name, manufactured by JSR), amorphous polyolefin (ZEONEX: trade name, manufactured by Nippon Zeon), and the like. Of these, triacetyl cellulose, polyethylene terephthalate, and polyethylene naphthalate are preferable, and triacetyl cellulose is particularly preferable.
Triacetyl cellulose consists of a single layer or a plurality of layers. A single-layer triacetyl cellulose is produced by drum casting or band casting disclosed in JP-A-7-11055 and the like. It is prepared by the so-called co-casting method disclosed in Japanese Patent Application Laid-Open Nos. 61-94725 and 62-43846. That is, the raw material flakes are solvents such as halogenated hydrocarbons (dichloromethane, alcohols (methanol, ethanol, butanol, etc.), esters (methyl formate, methyl acetate, etc.), ethers (dioxane, dioxolane, diethyl ether, etc.), etc. A solution (called a dope) with various additives such as a plasticizer, an ultraviolet absorber, an anti-degradation agent, a slipping agent, and a peeling accelerator is added to the horizontal endless as necessary. When casting by a dope supply means (called a die) on a support composed of a metal belt or a rotating drum, a single dope is cast in a single layer if it is a single layer, and a high concentration in the case of multiple layers. A low-concentration dope is co-cast on both sides of the cellulose ester dope, and the film is dried to some extent on the support to release the rigid film, and then peeled off from the support. A process comprising passed through a drying section by species of the conveying means to remove the solvent.

A typical solvent for dissolving triacetyl cellulose as described above is dichloromethane. However, from the viewpoint of the global environment and working environment, the solvent preferably does not substantially contain a halogenated hydrocarbon such as dichloromethane. “Substantially free” means that the proportion of halogenated hydrocarbon in the organic solvent is less than 5% by mass (preferably less than 2% by mass).
In preparing a triacetyl cellulose dope using a solvent substantially free of dichloromethane or the like, a special dissolution method as described later is essential.

  The first dissolution method is called a cooling dissolution method and will be described below. First, triacetyl cellulose is gradually added to a solvent at a temperature around room temperature (-10 to 40 ° C.) while stirring. The mixture is then cooled to -100 to -10 ° C (preferably -80 to -10 ° C, more preferably -50 to -20 ° C, most preferably -50 to -30 ° C). The cooling can be performed, for example, in a dry ice / methanol bath (−75 ° C.) or a cooled diethylene glycol solution (−30 to −20 ° C.). When cooled in this manner, the mixture of triacetyl cellulose and solvent solidifies. Furthermore, when this is heated to 0 to 200 ° C. (preferably 0 to 150 ° C., more preferably 0 to 120 ° C., most preferably 0 to 50 ° C.), a solution in which triacetyl cellulose flows in the solvent is obtained. The temperature may be increased by simply leaving it at room temperature or in a warm bath.

  The second method is called a high temperature melting method and will be described below. First, triacetyl cellulose is gradually added to a solvent at a temperature around room temperature (-10 to 40 ° C.) while stirring. The triacetyl cellulose solution of the present invention is preferably swollen beforehand by adding triacetyl cellulose to a mixed solvent containing various solvents. In this method, the dissolution concentration of triacetyl cellulose is preferably 30% by mass or less, but is preferably as high as possible from the viewpoint of drying efficiency during film formation. Next, the organic solvent mixed solution is heated to 70 to 240 ° C. under a pressure of 0.2 MPa to 30 MPa (preferably 80 to 220 ° C., more preferably 100 to 200 ° C., most preferably 100 to 190 ° C.). Next, since these heated solutions cannot be applied as they are, it is necessary to cool them below the lowest boiling point of the solvent used. In that case, it is common to cool to -10-50 degreeC and to return to a normal pressure. For cooling, the high-pressure and high-temperature vessel or line containing the triacetylcellulose solution may be left at room temperature, and more preferably, the apparatus may be cooled using a coolant such as cooling water. A cellulose acetate film substantially free of halogenated hydrocarbons such as dichloromethane and a process for producing the same are disclosed in JIII Journal of Technical Disclosure (Publication No. 2001-1745, published on March 15, 2001, hereinafter Published Technical Report 2001-1745). (Abbreviated as No.).

  When the optical film of the present invention, particularly an antireflection film, is used in a liquid crystal display device, it is disposed on the outermost surface of the display by providing an adhesive layer on one side. When the transparent support is triacetylcellulose, since triacetylcellulose is used as a protective film for protecting the polarizing layer of the polarizing plate, it is costly to use the optical film of the present invention, particularly the antireflection film, as it is for the protective film. Preferred above.

The optical film of the present invention, particularly the antireflection film, is disposed on the outermost surface of the display by providing an adhesive layer on one side, or when used as it is as a protective film for a polarizing plate, for sufficient adhesion It is preferable to carry out a saponification treatment after forming an outermost layer mainly composed of a fluorine-containing polymer on a transparent support. The saponification treatment is performed by a known method, for example, by immersing the film in an alkali solution for an appropriate time. After being immersed in the alkaline solution, it is preferable to sufficiently wash with water or neutralize the alkaline component by dipping in a dilute acid so that the alkaline component does not remain in the film.
By saponification treatment, the surface of the transparent support opposite to the side having the outermost layer is hydrophilized.
The hydrophilized surface is particularly effective for improving the adhesion with a deflection film containing polyvinyl alcohol as a main component. In addition, the hydrophilic surface makes it difficult for dust in the air to adhere to it, so it is difficult for dust to enter between the deflection film and the antireflection film when bonded to the deflection film, thus preventing point defects due to dust. It is valid.
The saponification treatment is preferably carried out so that the contact angle of water on the surface of the transparent support opposite to the side having the outermost layer is 40 ° or less. More preferably, it is 30 ° or less, particularly preferably 20 ° or less.

Specific means for the alkali saponification treatment can be selected from the following two means (1) and (2). (1) is superior in that it can be processed in the same process as a general-purpose triacetylcellulose film, but since the surface of the antireflection film is saponified, the surface is alkali-hydrolyzed and the film deteriorates. The point that it becomes dirty when the liquid remains can be a problem. In that case, although it becomes a special process, (2) is excellent.
(1) After the antireflection layer is formed on the transparent support, the back surface of the film is saponified by immersing it in an alkaline solution at least once.
(2) Before or after the formation of the antireflection layer on the transparent support, the alkaline liquid is applied to the surface of the antireflection film opposite to the surface on which the antireflection film is formed, and is heated, washed and / or washed. By summing, only the back surface of the film is saponified.

The antireflection film preferably has a haze value of 3 to 70%, more preferably in the range of 4 to 60%, and an average reflectance of 450 nm to 650 nm is preferably 3.0% or less, More preferably, it is 2.5% or less.
When the antireflection film has a haze value and an average reflectance within the above ranges, good antiglare properties and antireflection properties can be obtained without causing deterioration of the transmitted image.

[Optical compensation film]
The optical film of the present invention can also be applied to an optical compensation film. As an optical compensation film, for example, a film having an optically anisotropic layer made of a liquid crystal compound is known.
Such an optically anisotropic layer is preferably designed so as to compensate for the liquid crystal compound molecules in the liquid crystal cell in the black display of the liquid crystal display device. The alignment state of the liquid crystal compound molecules in the liquid crystal cell in black display varies depending on the mode of the liquid crystal display device. Regarding the alignment state of the liquid crystal compound molecules in this liquid crystal cell, IDW'00, FMC7-2, p. 411-414.

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

Preferable examples of the rod-like liquid crystal include those described in JP 2000-304932A.
Examples of discotic liquid crystals include C.I. Destrade et al., Mol. Cryst. 71, 111 (1981), benzene derivatives described in C.I. Destrade et al., Mol. Cryst. 122, 141 (1985), Physicslett, A, 78, 82 (1990); Kohne et al., Angew. Chem. 96, page 70 (1984) and the cyclohexane derivatives described in J. Am. M.M. Lehn et al. Chem. Commun. , 1794 (1985), J. Am. Zhang et al., J. Am. Chem. Soc. 116, 2655 (1994), and azacrown and phenylacetylene macrocycles. The discotic liquid crystal generally has a structure in which these are used as a mother nucleus at the center of a molecule, and a linear alkyl group, an alkoxy group, a substituted benzoyloxy group, etc. are radially substituted as the linear chain. Show. However, the molecule itself is not limited to the above description as long as the molecule itself has negative uniaxiality and can give a certain orientation. Further, in the present invention, the term “formed from a discotic compound” does not require that the final substance is the above-mentioned compound. For example, a low molecular discotic liquid crystal has a group that reacts with heat, light, or the like. As a result, it may be polymerized or cross-linked by reaction with heat, light, etc., resulting in high molecular weight and loss of liquid crystallinity. Preferred examples of the discotic liquid crystal include those described in JP-A-8-50206. Moreover, the discotic compound described in JP2001-100042A can also be used.

The optically anisotropic layer is generally formed by applying a solution obtained by dissolving a discotic compound and other compounds (eg, plasticizer, surfactant, polymer, etc.) in a solvent onto the alignment film, drying, and then discotic nematic. It is obtained by heating to the phase formation temperature and then cooling while maintaining the orientation state (discotic nematic phase). Alternatively, the optically anisotropic layer is formed by applying a solution obtained by dissolving a discotic compound and another compound (for example, a polymerizable monomer, a photopolymerization initiator) in a solvent onto the alignment film, drying, and then discotic It is obtained by heating to the nematic phase formation temperature, polymerizing (by irradiation with UV light or the like), and further cooling.
As the polymer used for the optically anisotropic layer, the compounds described for the actinic radiation curable resin described for the optical film can be used. Moreover, about the surfactant used for an optically anisotropic layer, the compound demonstrated with the component which has the surface active action demonstrated with the above-mentioned optical film can be used.

As described above, since the optically anisotropic layer contains an actinic radiation curable resin or the like, the optical compensation film particularly includes a repellant component that causes point defects in the optically anisotropic layer. May be. Therefore, it is desirable to remove the repelling component by performing the above-described filtration treatment on the optically anisotropic layer. By performing the above filtration treatment on the optically anisotropic layer, the number of point defects of 100 μm or more in these layers can be reduced to 2 or less per 1 m ² of film.

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

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

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

The alignment film is preferably formed by polymer rubbing treatment. In principle, the polymer used for the alignment film has a molecular structure having a function of aligning liquid crystal molecules.
In the present invention, in addition to the function of aligning liquid crystal molecules, a crosslinkable function having a function of aligning a side chain having a crosslinkable functional group (eg, a double bond) to the main chain or aligning liquid crystal molecules. It is preferred to introduce the group into the side chain.
As the polymer used for the alignment film, either a polymer that can be crosslinked by itself or a polymer that is crosslinked by a crosslinking agent can be used, and a plurality of combinations thereof can be used.

Examples of the polymer include, for example, a methacrylate copolymer, a styrene copolymer, a polyolefin, a polyvinyl alcohol and a modified polyvinyl alcohol described in JP-A-8-338913, paragraph [0022], and poly (N-methylolacrylamide). , Polyester, polyimide, vinyl acetate copolymer, carboxymethyl cellulose, polycarbonate and the like. Most preferred are polyvinyl alcohol and modified polyvinyl alcohol.
Specific examples of the alignment film forming composition such as the modified polyvinyl alcohol compound and the crosslinking agent include those described in JP-A Nos. 2000-155216 and 2002-62426.
The thickness of the alignment film is preferably in the range of 0.1 to 10 μm.

[Polarizer]
The polarizing plate is mainly composed of two protective films that sandwich the polarizing film from both sides. The optical film of the present invention, particularly the antireflection film, is preferably used for at least one of the two protective films sandwiching the polarizing film from both sides. Since the antireflection film also serves as a protective film, the manufacturing cost of the polarizing plate can be reduced. Further, by using an antireflection film as the outermost layer, reflection of external light and the like can be prevented, and a polarizing plate having excellent scratch resistance, antifouling properties, and the like can be obtained.

As the polarizing film, a known polarizing film or a polarizing film cut out from a long polarizing film whose absorption axis is neither parallel nor perpendicular to the longitudinal direction may be used. A long polarizing film whose absorption axis is neither parallel nor perpendicular to the longitudinal direction is produced by the following method.
That is, a polarizing film stretched by applying tension while holding both ends of a continuously supplied polymer film by a holding means, stretched at least 1.1 to 20.0 times in the film width direction, The progress of the film is such that the difference between the moving speeds in the longitudinal direction of the holding device is within 3%, and the angle formed by the film moving direction at the exit of the step of holding both ends of the film and the substantial stretching direction of the film is inclined by 20 to 70 °. The film can be produced by a stretching method in which the direction is bent while holding both ends of the film. In particular, those inclined by 45 ° are preferably used from the viewpoint of productivity.

The method for stretching the polymer film is described in detail in paragraphs [0020] to [0030] of JP-A-2002-86554.
One of the two protective films of the polarizer is preferably the optical film of the present invention. It is particularly preferable that one side is an antireflection film. Furthermore, the film other than the antireflection film is preferably an optical compensation film having an optical compensation layer comprising an optically anisotropic layer. The optical compensation film (retardation film) can improve the viewing angle characteristics of the liquid crystal display screen.

Of the two protective films of the polarizer, it is preferable that the transparent support of at least one protective film satisfies the following formulas (I) and (II) because the display improvement effect from the oblique direction of the liquid crystal display screen is high. In particular, it is particularly preferable that the transparent support of the present invention satisfies the following formulas (I) and (II).
(I): 0 ≦ Re (630) ≦ 10 and | Rth (630) | ≦ 25
(II): | Re (400) −Re (700) | ≦ 10 and | Rth (400) −Rth (700) | ≦ 35

[Image display device]
The optical film and antireflection film of the present invention can be applied to an image display device such as a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), or a cathode ray tube display device (CRT). it can. Since the antireflection film of the present invention has a transparent support, the transparent support side is adhered to the image display surface of the image display device.

  When the optical film and antireflection film of the present invention are used as one side of a surface protective film of a polarizing film, twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS) ), Transmissive, reflective, or transflective liquid crystal display devices such as an optically compensate bend cell (OCB).

  The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). (2) In addition to (2) Liquid crystal cell (SID97, Digest of tech. Papers (Preliminary Collection) 28 (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for viewing angle expansion ), (3) A liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary collections 58-59 of the Japan Liquid Crystal Society) (1998)) and (4) SURVAVAL mode liquid crystal cells (announced at LCD International 98).

  The OCB mode liquid crystal cell is a liquid crystal display device using a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in a substantially opposite direction (symmetrically) between the upper part and the lower part of the liquid crystal cell. It is disclosed in the specifications of Japanese Patent Nos. 45882525 and 5410422. Since the rod-like liquid crystal molecules are symmetrically aligned at the upper and lower portions of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function. Therefore, this liquid crystal mode is also called an OCB (Optically Compensatory Bend) liquid crystal mode. The bend alignment mode liquid crystal display device has an advantage of high response speed.

Furthermore, as a whole including a liquid crystal cell in a bend alignment mode and a polarizing plate including an optically anisotropic layer, the optical characteristics satisfying the following formula (1 ′) are obtained in any of the wavelength 450 nm, wavelength 550 nm, and wavelength 630 nm measurements. It is preferable to have a display improvement effect from an oblique direction of the liquid crystal display screen, and it is particularly preferable that a polarizing plate using the optical film of the present invention as a protective film satisfies the following formula (1 ′).
Formula (1 ′): 0.05 <(Δn × d) / (Re × Rth) <0.20
[In the formula (1 ′), Δn is the intrinsic birefringence of the rod-like liquid crystalline molecule in the liquid crystal cell; d is the thickness of the liquid crystal layer of the liquid crystal cell in nm; Re is the optically anisotropic layer Rth is the retardation value in the thickness direction of the entire optically anisotropic layer.

  In an ECB mode liquid crystal cell, rod-like liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and is most frequently used as a color TFT liquid crystal display device, and is described in many documents. For example, it is described in “EL, PDP, LCD display” published by Toray Research Center (2001).

  Particularly for TN mode and IPS mode liquid crystal display devices, as described in JP-A-2001-100043, an optical compensation film having an effect of widening the viewing angle is used as a protective film having two polarizing films on both sides. Of these, a polarizing plate having an antireflection effect and a viewing angle widening effect can be obtained with the thickness of one polarizing plate by using it on the surface opposite to the antireflection film of the present invention.

  Hereinafter, the present invention will be specifically described in detail based on examples, but the present invention is not limited thereto.

[Example 1]
(Preparation of solution A)
As a commercially available actinic radiation curable resin, a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) is diluted in a mixed solvent of MEK / cyclohexanone (1/1), A 20% by mass solution was obtained. As a result of analyzing this resin solution by the atomic absorption method, it was found that the solution contained 390 ppb silicone.
This solution was filtered for 2 hours at a flow rate of 1 liter / min with a Paul Profile II 0.5μ filter (one 10 inch cartridge), and a solution not subjected to the filtration treatment. These were prepared as Solution A. When the amount of silicone of the solution A subjected to the filtration treatment was confirmed, the amount of silicone was not more than the detection limit (about 200 ppb).

(Preparation of coating solution B for optical functional layer)
A 625 g MEK solution (solid content concentration 72 mass%, silica content 38 mass%) of JSR hard coat material Desolite Z7503 was dissolved in 375 g of a mixed solvent of methyl ethyl ketone / cyclohexanone = 50/50 mass%. A coating solution B was prepared.

(Preparation of coating liquid C-2 for optical functional layer)
To a mixed solvent of cyclohexanone and methyl ethyl ketone, a hard coat coating solution (Z7401, manufactured by JSR Corporation) containing a zirconium dioxide particle dispersion having an average particle size of 20 nm was added while stirring with an air disperser. To this solution, the filtered solution A or the unfiltered solution A is added, and further 2% by mass of a polymerization initiator (Irgacure 907, Ciba Specialty Chemicals Co., Ltd.) ), And adjusted to have a refractive index of 1.60 to prepare liquid C-1. The solid concentration at this time was 45%. With respect to this liquid C-1, what performed filtration processing and what was not performed were produced. In addition, it showed in Table 1 about the filtration process conditions of what filtered the liquid C-1.
Furthermore, in this liquid C-1, crosslinked polystyrene particles (trade name: SX-200H, refractive index 1.60, manufactured by Soken Chemical Co., Ltd.) having an average particle diameter of 2 μm dispersed for 20 minutes at 10,000 rpm with a Polytron disperser. A 10% by mass dispersion of MEK / cyclohexanone (1/1 mixture) was added at a ratio of 1.3 to the above liquid C-1: 10, and the mixture was stirred at high speed disperser 5000 rpm for 10 minutes. Coating solution C-2 was prepared. Also with respect to this coating liquid C-2, what performed filtration processing and what was not performed were produced. In addition, it showed in Table 1 also about the filtration process conditions of what filtered the coating liquid C-2.
In addition, the filter described in a present Example is Fujifilm Astropore PPE-03 (pore diameter 3micrometer), Pole company profile II (pore diameter 0.5micrometer, 3micrometer, 5micrometer, 10micrometer, 15micrometer), Chisso BM-7 ( Pore diameter 7 μm) and BM-10 (pore diameter 10 μm).
In the column of “Others” in Table 1, “With increased filtration pressure” indicates that the filtration pressure gradually increases when the coating liquid is circulated in the filtration step.

(Production of optical film)
As a support, a triacetyl cellulose film (TD80U, manufactured by Fuji Photo Film Co., Ltd.) is unwound in a roll form, and the coating liquid B for optical functional layer has a gravure pattern with 110 lines / inch and a depth of 65 μm and a diameter of 50 mm. Using a microgravure roll and a doctor blade, the coating was carried out at a conveyance speed of 30 m / min, dried at 90 ° C. for 40 seconds, and then an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 160 W / cm. Then, the coating layer was cured by irradiating ultraviolet rays having an illuminance of 400 mW / cm ² and an irradiation amount of 100 mJ / cm ² , and an optical functional layer was formed and wound. After curing, the thickness of the optical functional layer was about 4.5 μm.
On this layer, the coating solution C-2 for the optical functional layer, which was changed in the filtration treatment as shown in Table 1, was a micrometer having a diameter of 180 lines / inch and a gravure pattern with a depth of 38 μm and a diameter of 50 mm. Using a gravure roll and a doctor blade, it was applied at a transfer speed of 5 m / min, dried at 100 ° C. for 150 seconds, and further air-cooled metal halide lamp of 160 W / cm under nitrogen purge (manufactured by Eye Graphics Co., Ltd.) Was used to cure the coating layer by irradiating with ultraviolet rays having an illuminance of 400 mW / cm ² and an irradiation amount of 250 mJ / cm ² , forming an optical functional layer, and winding it. After curing, the thickness of the optical functional layer was about 1.7 μm.

(Evaluation of coated products)
About the said apply | coated film, about 10 m < ² >, the permeation | transmission test | inspection with a fluorescent lamp and the reflective inspection were performed, and the number of the faults was confirmed. Of these, the number of defects without core foreign matter was evaluated.
In addition, TOF-SIMS measurement was performed on some of the defects of each sample, and the cause of repelling was confirmed.

(result)
Table 1 shows the results of carrying out various filtration methods in Example 1 of the present invention.
From these results, it can be seen that Example Samples 1 to 6 using a polypropylene filter at the time of coating have the effect of reducing defects without foreign material nuclei, particularly repelling defects. In particular, the use of profile II, BM-7, which is a high-precision filtration depth type made of polypropylene, is highly effective.
Moreover, it turns out that the Example samples 7 and 8 which performed the filtration process before the particle | grain addition of a coating liquid also have the improvement effect of a fault. However, since the filtration treatment is not performed immediately after the addition of the crosslinked polystyrene particles, the occurrence of aggregation defects is observed.
Further, as can be seen from the results of Example Samples 9 to 15, in the filtration of the coating liquid C-1, by increasing the number of filtration filters and the filtration time, it is possible to reduce defects without foreign matter nuclei, particularly repelling defects.
Further, the point defects found in Comparative Example Sample 1 were found in Example Samples 1-10 and 12-14, whereas the concentration of the silicone-based compound was observed at 10 times or more the normal part concentration. From the point defects, the concentration concentration of the silicone-based compound in the central part was all 10 times or less.
As described above, the effect of improving the repellency defect according to the present invention is clear.

[Example 2]
(Preparation of coating solution D for light diffusion layer)
285 g of a commercially available zirconia-containing UV curable hard coat liquid (Desolite Z7404, manufactured by JSR Corporation, solid content concentration of about 61% by mass, ZrO ₂ content in the solid content of about 70% by mass, polymerizable monomer, polymerization initiator contained) 85 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) was mixed, and further diluted with 60 g of methyl isobutyl ketone and 17 g of methyl ethyl ketone. Furthermore, 28 g of a silane coupling agent (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed and stirred. This solution is designated as DA solution. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.61. It was confirmed by proton NMR measurement that the silane coupling agent used at this time contained 400 ppm of polydimethylsiloxane.
What performed the filtration process with respect to this DA liquid, and the thing which is not performed were produced. In addition, it showed in Table 2 about the filtration process conditions of what filtered the DA liquid.

Furthermore, a 30% by mass methyl isobutyl ketone dispersion of classified strengthened crosslinked PMMA particles (refractive index 1.49, MXS-300, manufactured by Soken Chemical Co., Ltd.) having an average particle size of 3.0 μm was added to the DA solution with a Polytron disperser. 35 g of a dispersion liquid dispersed at 10,000 rpm for 20 minutes was added, and then a 30 mass% methyl ethyl ketone dispersion liquid of silica particles having an average particle diameter of 1.5 μm (refractive index: 1.46, Seahosta KE-P150, manufactured by Nippon Shokubai Co., Ltd.) 90 g of a dispersion dispersed for 30 minutes at 10,000 rpm in a polytron disperser was added. Let this coating liquid be DB.
Moreover, what changed the timing which adds 0.12 g of fluorine-type polymer (FP-8) in a liquid preparation process with respect to liquid DA or coating liquid DB as shown in Table 2 was produced simultaneously.

(Preparation of coating solution E for antiglare hard coat layer)
50 g of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (PETA, Nippon Kayaku Co., Ltd.) was diluted with 38.5 g of toluene. Furthermore, 2 g of a polymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) was added, mixed and stirred to prepare an EA solution. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.51.
Further, a 30% by mass toluene dispersion of polystyrene particles having an average particle diameter of 3.5 μm (refractive index: 1.60, SX-350, manufactured by Soken Chemical Co., Ltd.) dispersed in this solution for 20 minutes at 10,000 rpm with a Polytron disperser. An EB solution was prepared by adding 13.3 g of a 30% by mass toluene dispersion of 1.7 g and acrylic-styrene particles having an average particle size of 3.5 μm (refractive index: 1.55, manufactured by Soken Chemical Co., Ltd.).
Further, 0.75 g of a fluorine-based polymer (FP-8) and 10 g of a silane coupling agent (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.) are added to the coating liquid EA or EB (addition timing is shown in Table 2). Street).

(Production of optical film)
A triacetyl cellulose film (TD80U, manufactured by Fuji Photo Film Co., Ltd.) is unwound in a roll form as a support, and the coating liquid D is a microgravure roll having a diameter of 135 lines / inch and a gravure pattern with a depth of 60 μm and a diameter of 50 mm. Using a doctor blade and a transfer speed of 20 m / min, drying at 100 ° C. for 40 seconds, and further using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) at an illumination intensity of 400 mW. The coating layer was cured by irradiating with UV light of / cm ² and an irradiation amount of 250 mJ / cm ² , and an optical functional layer was formed and wound. After curing, the thickness of the optical functional layer was about 3.4 μm.
Similarly, using a microgravure roll with a diameter of 110 mm / inch and a gravure pattern with a depth of 65 μm and a doctor blade on the support, a gravure roll rotation speed of 45 rpm and a conveyance speed of 30 m / min. After coating at 60 ° C. for 150 seconds and using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) under a nitrogen purge, an illuminance of 400 mW / cm ² and an irradiation amount of 200 mJ / The coating layer was cured by irradiating cm ² ultraviolet rays to form a functional layer of an antiglare hard coat layer (thickness 6 μm) and wound up.
Table 2 shows Examples 21 to 30 and Comparative Example 21 in which the filtration conditions were changed for the coating liquids D and E described above.

From this result, the improvement of the defect without foreign substance nuclei in the filtration treatment of the present invention, in particular, the effect on the repelling defect can be seen. Further, when the coating solution DA filtration before the addition of particles and the immediately preceding filtration with the coating solution are combined, the improvement effect is great. Further, when the number of filters before application is increased in series, the filter is further improved.
Moreover, when adding a silane coupling agent and a fluoropolymer in this coating liquid, there exists an improvement effect by adding at the timing which can be filtered with a filter with a smaller pore diameter. However, it can also be improved by increasing the number of the previous filtration filters in the coating solution.
In addition, the point defects found in the comparative sample 21 were observed in the example samples 21 to 23 and 25, whereas the concentration of the silicone compound was observed to be 10 times or more of the normal part concentration in the central part. Defects were all concentrated in the concentration of the silicone compound at the center by 10 times or less.
Of the above examples, in Examples 25 to 30 to which the fluoropolymer was added, samples with good surface shape were obtained with little wind unevenness.

Further, a low refractive index layer was applied to Example Samples 24, 27, and 30 in the following procedure.
(Preparation of sol solution a)
To a reactor equipped with a stirrer and a reflux condenser, 120 parts of methyl ethyl ketone, 100 parts of acryloyloxypropyltrimethoxysilane (KBM5103 (trade name); manufactured by Shin-Etsu Chemical Co., Ltd.) and 3 parts of diisopropoxyaluminum ethyl acetoacetate are added and mixed. did. Furthermore, 30 parts of ion-exchanged water was added and reacted at 60 ° C. for 4 hours, and then cooled to room temperature to obtain a sol solution a. The mass average molecular weight was 1800, and among the components higher than the oligomer component, the component having a molecular weight of 1000 to 20000 was 100% by mass. Further, from the gas chromatography analysis, the raw material acryloyloxypropyltrimethoxysilane did not remain at all.

(Preparation of coating solution for low refractive index layer)
The following composition was put into a mixing tank, stirred, and then filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a low refractive index layer.
<Composition of coating liquid F for low refractive index layer>
Opstar JN7228A 100 parts by mass (thermally crosslinkable fluorine-containing polymer composition: manufactured by JSR Corporation)
MEK-ST 4.3 parts by mass (silica dispersion, average particle size 15 nm: manufactured by Nissan Chemical Co., Ltd.)
MEK-ST different particle size 5.1 parts by mass (silica dispersion average particle size 45 nm: manufactured by Nissan Chemical Co., Ltd.)
Sol liquid a 2.2 parts by mass MEK 15.0 parts by mass
3.6 parts by mass of cyclohexanone

  Further, instead of the heat-crosslinkable fluorine-containing polymer JN7228A used in the low refractive index layer coating solution F, a heat-crosslinkable fluorine-containing polymer having a refractive index of 1.44 (JTA-113, solid content concentration 6%, JSR A coating solution G was also prepared in the same manner.

(Coating of low refractive index layer)
The triacetylcellulose film coated with the above functional layers of Example Samples 24, 27, and 30 was unwound again, and the coating solution for low refractive index layer shown in Tables 1 to 3 was 200 lines / inch and the depth was 30 μm. Using a microgravure roll with a diameter of 50 mm and a doctor blade having a gravure pattern, the coating was applied at a gravure roll rotation speed of 30 rpm and a conveyance speed of 15 m / min, dried at 120 ° C. for 150 seconds, and further at 140 ° C. for 8 minutes. Using a 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) under a nitrogen purge, the film was irradiated with ultraviolet light having an illuminance of 400 mW / cm ² and an irradiation amount of 900 mJ / cm ² . An antireflection film was formed by forming a low refractive index layer and wound up.
In this manner, Example Samples 24F, 27F, and 30F applied with the low refractive index layer coating solution F and Example Samples 24G, 27G, and 30G applied with the low refractive index layer coating solution G were prepared.

(Saponification treatment of antireflection film)
The antireflection film was subjected to the following treatment.
A 1.5 mol / l aqueous sodium hydroxide solution was prepared and kept at 55 ° C. A 0.01 mol / l dilute sulfuric acid aqueous solution was prepared and kept at 35 ° C. The prepared antireflection film was immersed in the aqueous sodium hydroxide solution for 2 minutes, and then immersed in water to sufficiently wash away the aqueous sodium hydroxide solution. Subsequently, after being immersed in the above-mentioned dilute sulfuric acid aqueous solution for 1 minute, it was immersed in water to sufficiently wash away the dilute sulfuric acid aqueous solution. Finally, the sample was thoroughly dried at 120 ° C.
In this way, saponified antireflection films (Example Samples 24F, 27F, 30F, 24G, 27G, 30G) were produced.

(Evaluation of antireflection film)
About these obtained antireflection film samples, the following items were evaluated. The results are shown in Table 3.

(1) Average reflectance Using a spectrophotometer (manufactured by JASCO Corporation), the spectral reflectance at an incident angle of 5 ° was measured in a wavelength region of 380 to 780 nm. For the results, an integrating sphere average reflectance of 450 to 650 nm was used.

(2) Steel wool scratch resistance evaluation A rubbing test was performed under the following conditions using a rubbing tester.
Evaluation environmental conditions: 25 ° C., 60% RH
Rubbing material: Steel wool (made by Nippon Steel Wool Co., Ltd., Geled No. 0000) was wound around the rubbing tip (1 cm × 1 cm) of a tester that was in contact with the sample, and the band was fixed so as not to move.
Moving distance (one way): 13 cm, rubbing speed: 13 cm / sec, load: 500 g / cm ² , tip contact area: 1 cm × 1 cm, rubbing frequency: 10 reciprocations.
An oil-based black ink was applied to the back side of the rubbed sample and visually observed with reflected light, and scratches on the rubbed portion were evaluated according to the following criteria.
A: Even when viewed very carefully, no scratches are visible.
○: Slightly weak scratches are visible when viewed very carefully.
○ △: Weak scratches are visible.
Δ: Moderate scratches are visible.
Δ × ˜ ×: There is a scratch that can be seen at first glance.

(3) Evaluation of resistance to rubbing with a cotton swab A cotton swab is fixed to the rubbing tip of a rubbing tester, and the upper and lower sides of the sample are fixed with clips in a smooth dish, and the sample and the swab are immersed in water at 25 ° C at room temperature 25 ° C. A rubbing test was performed by applying a load of 500 g and changing the number of rubbing. The rubbing conditions are as follows.
Rubbing distance (one way): 1 cm, rubbing speed: about 2 reciprocations / second The sample after rubbing was observed, and the rubbing resistance was evaluated as follows according to the number of film peeling.
×: Film peeling after 0-10 round trips × Δ: Film peeling after 10-30 round trips Δ: Film peeling after 30-50 round trips ○ △: Film peeling after 50-100 round trips ○: Film peeling after 100-150 round trips ◎: 150 No film peeling even when reciprocating

  From the above results, it can be seen that an antireflection film having few defects due to point defects and having high scratch resistance can be obtained.

Example 3
An optical compensation film was produced as follows.
(Saponification treatment of cellulose acetate film)
The cellulose acetate film was immersed in an aqueous 1.5N sodium hydroxide solution at 55 ° C. for 2 minutes. It wash | cleaned in the room temperature water-washing tub, and neutralized using 0.1 N sulfuric acid at 30 degreeC. Again, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C. In this way, the surface of the cellulose acetate film was saponified.

(Formation of alignment film)
On one surface of the saponified cellulose acetate film (transparent support), a coating solution having the following composition was applied at 24 ml / m ² with a # 14 wire bar coater. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 90 ° C. for 150 seconds.
Next, the formed alignment film was rubbed.
<Alignment film coating solution composition>
Modified polyvinyl alcohol 20 parts by mass Water 360 parts by mass Methanol 120 parts by mass Glutaraldehyde (crosslinking agent) 1.0 part by mass

(Formation of optically anisotropic layer)
On the alignment film, 91.0 parts by mass of the following discotic liquid crystalline molecules, 9.0 parts by mass of ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.), cellulose acetate butyrate ( CAB531-1, manufactured by Eastman Chemical Co., Ltd.) 1.5 parts by mass, photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy Co.), sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1.0 part by mass, fluorosurfactant MegaFac F-780-F solution 1.25 parts by mass were dissolved in 135 parts by mass of methyl ethyl ketone. Thereafter, methyl ethyl ketone was appropriately added to prepare a coating liquid H having a specific gravity of 0.909. Using 100 kg of this coating liquid, a liquid that was circulated and filtered at a flow rate of 1 kg / L for 200 minutes with one 10 inch cartridge of polypropylene filter profile II 0.5 μm and a liquid that was not used were prepared.

The coating liquid H containing discotic liquid crystalline molecules prepared as described above was applied to the cellulose acetate film provided with the alignment film with a # 3 wire bar coater. After the application, the mixture was heated in a drying zone at 130 ° C. for 2 minutes to align the discotic liquid crystal molecules. Next, using a 120 W / cm high-pressure mercury lamp at 80 ° C., UV irradiation was performed for 1 minute to polymerize the discotic liquid crystalline molecules. Then, it stood to cool to room temperature. Thus, an optically anisotropic layer was formed and an optical compensation film was produced.
The defect without foreign matter nuclei of this sample was that the repulsion defect was 2 pieces / m ² in the case where the circulation filtration was not carried out, whereas the one subjected to the circulation filtration was 0.2 pieces / m ² . It was found that an optical compensation film with few repelling defects can be obtained by the circulation filtration operation.

Example 4
The PVA film was immersed in an aqueous solution of 2.0 g / l of iodine and 4.0 g / l of potassium iodide at 25 ° C. for 240 seconds, and further immersed in an aqueous solution of boric acid 10 g / l at 25 ° C. for 60 seconds. And it introduce | transduces into the tenter extending | stretching machine of the form of FIG. 2 as described in Unexamined-Japanese-Patent No. 2002-86554 (FIG. 2), extends | stretches 5.3 time, and bends a tenter with respect to the extending | stretching direction (above-mentioned) After that, the width was kept constant thereafter. After drying in an atmosphere of 80 ° C., it was detached from the tenter. The difference in transport speed between the left and right tenter clips was less than 0.05%, and the angle between the center line of the introduced film and the center line of the film sent to the next process was 46 °. Here, | L1-L2 | is 0.7 m, W is 0.7 m, and | L1-L2 | = W. The substantial stretching direction Ax-Cx at the tenter outlet was inclined by 45 ° with respect to the center line 22 of the film sent to the next process. Wrinkles and film deformation at the tenter exit were not observed.
Further, it was bonded to Fuji Photo Film Co., Ltd. Fujitac (cellulose triacetate, retardation value 3.0 nm), which was saponified using an aqueous 3 mass% PVA (Kuraray Co., Ltd. PVA-117H) aqueous solution as an adhesive, and further 80 A polarizing plate having an effective width of 650 mm was obtained by drying at ° C. The absorption axis direction of the obtained polarizing plate was inclined 45 ° with respect to the longitudinal direction. The polarizing plate had a transmittance at 550 nm of 43.7% and a polarization degree of 99.97%. Further, when the substrate was cut into a size of 310 × 233 mm, a polarizing plate having a 45 ° absorption axis inclined with respect to the side with an area efficiency of 91.5% was obtained.
Next, each film of Example Samples 27G and 30G (saponified) prepared in Example 2 was bonded to the polarizing plate to prepare a polarizing plate with antiglare and antireflection. Using this polarizing plate, a liquid crystal display device having an antireflection layer disposed on the outermost layer was produced. As a result, there was no reflection of external light, and an excellent contrast was obtained. It had visibility.

Example 5
80 μm-thick triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.), which was immersed in an aqueous 1.5 mol / l, 55 ° C. NaOH solution for 2 minutes, then neutralized and washed, and Examples Polarizers were prepared by adhering iodine to polyvinyl alcohol on the backside saponified triacetyl cellulose films of Samples 27G and 30G and stretching and bonding and protecting both sides of the polarizer. The thus-prepared polarizing plate is a liquid crystal display device of a notebook PC equipped with a transmission type TN liquid crystal display device (Sumitomo 3M Co., Ltd., which is a polarization separation film having a polarization selection layer) so that the antireflection film side is the outermost surface. When the polarizing plate on the viewing side of D-BEF made of D-BEF (having between the backlight and the liquid crystal cell) was replaced, a display device with extremely high display quality was obtained with very little background reflection.

[Example 6]
Using cellulose acylate having an acetyl substitution degree of 2.94, optical anisotropy reducing agent A-19 was 49.3% (vs. cellulose acylate), and chromatic dispersion regulator UV-102 was 7.6% (vs. cellulose). A cellulose acylate sample 201 having a thickness of 80 μm was prepared by the same film forming method as disclosed in JP-A-61-94725 and JP-B-62-43846. The retardation Re of the obtained film was −1.0 nm (negative because of the slow axis in the TD direction), and the retardation Rth in the thickness direction was −2.0 nm, both sufficiently small values. When this cellulose acylate film sample was used as a transparent support for the protective film on the cell side of the two protective films of the polarizer and Example 1 of the present invention was used as the protective film on the viewer side of the polarizer, Japanese Patent Application Laid-Open No. Hei 10 Liquid crystal display device described in Example 1 of Japanese Patent No. -48420, an optically anisotropic layer containing discotic liquid crystal molecules described in Example 1 of Japanese Patent Application Laid-Open No. 9-26572, an alignment film coated with polyvinyl alcohol, Evaluations were made on the VA type liquid crystal display device shown in FIGS. 2 to 9 of Kaikai 2000-154261 and the OCB type liquid crystal display device shown in FIGS. 10 to 15 of Japanese Patent Laid-Open No. 2000-154261. The performance with a good contrast viewing angle was obtained.

(A) and (B) have shown an example of the method of the filtration process. (A) and (B) have shown an example of the method of the filtration process. (A) is a cross-sectional schematic diagram which shows the layer structure of an anti-glare antireflection film. (B) is a cross-sectional schematic diagram which shows the layer structure of the antireflection film excellent in antireflection performance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antireflection film 2 Transparent support 3 Hard coat layer 4 Anti-glare hard coat layer 5 Low refractive index layer 6 Fine particle 7 Middle refractive index layer 8 High refractive index layer

Claims (21)

An optical film formed by applying a coating solution containing a solvent and an actinic radiation curable resin on a film substrate to form a coating layer, and a point defect of 100 μm or more in the coating layer per 1 m ^{2 of} film An optical film having two or less. An optical film obtained by coating a coating liquid containing an organic silyl compound represented by the following general formula a, a hydrolyzate thereof or a partial condensate thereof on a film substrate to form a coating layer, 2. The optical film according to claim 1, wherein the number of point defects of 100 μm or more in the coating layer is 2 or less per 1 m ^{2 of the} film.
Formula a
(R) mSi (X) n
(R represents a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms or a substituted or unsubstituted aryl group. X represents —OH, a halogen atom, —OR ¹ group, or OCOR ¹ group. R ¹ represents Represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, m + n is 4, and m and n are each an integer of 0 or more.)   3. The optical film according to claim 1, wherein the point defect of 100 μm or more is a point defect having no core foreign matter.   The optical film according to any one of claims 1 to 3, wherein the coating liquid is filtered with a filter having a polyolefin filter material.   The optical film according to claim 4, wherein the filter is a depth type filter.   6. The optical film according to claim 1, comprising at least one of a fluorine-based compound and a silicone-based compound having a surface-active effect on the coating solution.   The optical film according to claim 6, wherein at least one of the fluorine compound and the silicone compound is present in the point defect portion of 100 μm or more at a concentration of 10 times or less as compared with a normal part.   The optical film according to any one of claims 1 to 7, wherein the solvent contains at least one of ketones, alcohols, aromatic hydrocarbons, and esters having a boiling point of 100 ° C or higher.   The optical film according to claim 1, wherein the coating liquid contains translucent particles.   The optical film according to claim 9, wherein the coating layer is an antiglare imparting layer.   The optical film according to any one of claims 1 to 10, wherein a low refractive index layer having a refractive index of 1.31 to 1.45 is provided on the coating layer.   The optical film according to claim 1, wherein a discotic compound is contained in the coating solution.   The polarizing plate, wherein the protective film on at least one side of the polarizing film is the optical film according to any one of claims 1 to 12.   A display device comprising the optical film according to claim 1 or the polarizing plate according to claim 13.   A step of filtering a coating solution containing a solvent and an actinic radiation curable resin with a depth type filter having a polyolefin filter material, and applying the filtered coating solution on a film substrate The manufacturing method of the optical film characterized by including the process to form. A step of filtering a coating solution containing an organic silyl compound represented by the following general formula a, a hydrolyzate thereof or a partial condensate thereof with a depth type filter having a polyolefin filter material, and the filtration treatment The method for producing an optical film according to claim 15, comprising a step of forming a coating layer by coating a coating solution on a film substrate.
Formula a
(R) mSi (X) n
(X represents —OH, a halogen atom, —OR ¹ group, or OCOR ¹ group. R ¹ represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms. R represents a substituted group having 1 to 30 carbon atoms. Or an unsubstituted alkyl group or an aryl group, m + n is 4, and m and n are each an integer of 0 or more.)   The method for producing an optical film according to claim 15, wherein a coating process is performed subsequent to the filtration process.   The method for producing an optical film according to claim 15, further comprising a step of adding an additive component to the filtered coating solution between the filtering step and the coating step.   Between the filtration process and the coating process, a step of adding an additive component to the filtered coating liquid, and a coating liquid to which the additive component is added, a depth type having a polyolefin filter medium The method for producing an optical film according to claim 15, comprising a step of filtering with a filter. A coating solution containing a solvent and an actinic radiation curable resin and / or an organic silyl compound represented by the following general formula a, a hydrolyzate thereof or a partial condensate thereof is applied onto a film substrate to form a coating layer. A method for producing an optical film, comprising the step of removing from the coating solution a component that generates a point defect that does not have a foreign substance that is a core of 100 μm or more in the coating layer. .
Formula a
(R) mSi (X) n
(X represents —OH, a halogen atom, —OR ¹ group, or OCOR ¹ group. R ¹ represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms. R represents a substituted group having 1 to 30 carbon atoms. Or an unsubstituted alkyl group or an aryl group, m + n is 4, and m and n are each an integer of 0 or more.)   21. The concentration of one of the fluorine-based compound having a surface activity and the silicone-based compound in a coating solution is 100 ppm or more, and the concentration in the other coating solution is 1 ppm or less. The manufacturing method of the optical film in any one of.

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