KR20170054293A - Optical film - Google Patents

Abstract

The objective of the present invention is to provide an optical film which, when used on a protective film of a polarizing plate, reduces the generation of cracks or particles in the process of punching the polarizing plate. The optical film of the present invention is an optical film containing a cycloolefin-based resin, wherein the cycloolefin-based resin is a cycloolefin-based resin containing at least one hydrogen-bonded water-soluble group; the film contains an alcohol-based solvent and a hindered phenol-based compound; and the film contains, with respect to the total mass of the film, 0.1-2.5 mass% of silica particles whose hydrophobicity measured by a methanol wettability method is 20% or less when using a first solution having a volume ratio of methanol to pure water of 3:7, and is 80% or more when using a second solution having a volume ratio of methanol to pure water of 6:4.

Description

Optical film {OPTICAL FILM}

The present invention relates to an optical film. More specifically, the present invention relates to an optical film and the like that reduce the occurrence of cracks and cutting powder during punching of a polarizing plate when the optical film is used for a protective film of a polarizing plate.

Conventionally, when a polarizing plate is cut for a liquid crystal display device, the shape is rectangular. However, from the viewpoint of improvement of designability and the like, in recent years, a display with a polygon or a curved line has appeared in a vehicle-mounted display such as a car navigation system, It is necessary to cut the polarizing plate corresponding to various shapes.

In addition, since a display mounted on a vehicle is exposed to a harsh environment such as high temperature and high humidity, an optical film using a resin having excellent heat resistance and moisture resistance, such as a cycloolefin resin film, is preferably used.

When the above-mentioned polarizing plate is cut into a shape other than a rectangular shape, it is necessary to perform punching with a preform. However, since curved portions and the like are not uniform in orientation direction of the polarizer or the protective film, Cracks are generated in the surface of the polarizing plate, and cutting powder is easily generated by cutting. This problem becomes more serious as the polarizing plate becomes thinner.

In general, matting agents (fine particles) such as silica particles are suitably used for improving handling properties in a film production process or a processing step. However, among the cycloolefin resins, silica particles tend to aggregate, The punching of the cracks is likely to become a starting point of the cracks.

Patent Document 1 discloses an example in which a matte particle is contained in a cycloolefin based resin film. It is obvious that the present invention can improve handling properties, but cracks during punching into the preform, It was insufficient to reduce occurrence.

Japanese Patent Application Laid-Open No. 2007-98643

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an optical film in which occurrence of cracks and cutting powder during punching of a polarizing plate is reduced when an optical film is used for a protective film of a polarizing plate will be.

In order to solve the above-mentioned problems, the inventors of the present invention have found that, in a process of examining the cause of the above problems, the present inventors have found that a cycloolefin-based resin having at least one hydrogen-bonding water-soluble group, an alcohol-based solvent, a hindered phenol- When the optical film is used for a protective film of a polarizing plate by an optical film containing a specific amount of silica particles satisfying a specific range as measured by the Wettability method, Can be obtained.

That is, the above object of the present invention is solved by the following means.

1. An optical film containing a cycloolefin-based resin,

Wherein the cycloolefin resin is a cycloolefin resin having at least one hydrogen-bond-soluble group,

Wherein the film contains an alcoholic solvent and a hindered phenolic compound,

Wherein the degree of hydrophobicity measured by the methanol wetting method is 20% or less when the first solution having methanol and pure water at a volume ratio of 3: 7 is used and the second solution having methanol and pure water at a volume ratio of 6: 4 Is contained in an amount of from 0.1 to 2.5% by mass based on the total mass of the film, the silica particles having a degree of hydrophobicity of 80% or more.

2. The optical film according to claim 1, wherein the silica particles have a secondary average particle diameter in the range of 100 to 400 nm.

3. The optical film according to claim 1 or 2, wherein the alcoholic solvent is contained in the range of 10 to 1000 ppm and the hindered phenol compound is contained in the range of 0.1 to 0.5 mass% .

4. The optical film according to any one of claims 1 to 3, further comprising water in a range of 50 to 500 ppm.

5. The film thickness d of the optical film is 5 占 퐉? D? 40 占 퐉 and the in-plane retardation Ro and the thickness direction retardation Rt at the measurement wavelength of 590 nm are Ro? 5 nm and -15 nm? 5. The optical film according to any one of claims 1 to 4,

According to the means of the present invention, it is possible to provide an optical film with reduced occurrence of cracks and cutting powder at the time of punching the polarizing plate when the optical film is used for the protective film of the polarizing plate.

Although the mechanism and mechanism for manifesting the effects of the present invention are not clarified, they are estimated as follows.

The technique of containing the matte particles disclosed in the above Patent Document 1 can improve the handling property but is insufficient to reduce the occurrence of cracks and cutting powder during punching into the preform.

Thus, the present inventors have found that an optical film having excellent handling in the manufacturing process and containing a specific compound in an optical film containing a cycloolefin-based resin can reduce the occurrence of cracks and cutting powder at the time of polarizing plate punching .

The optical film of the present invention is characterized in that the hydrophobicity measured by the cycloolefin resin having at least one hydrogen-bond-soluble group, the alcohol-based solvent, the hindered phenol-based compound and the methanol wettability method is Is an optical film comprising The optical film having such a structure can maintain the interaction between the resin and the matting agent when used in the protective film of the polarizing plate, so that the strength of the film is increased and the occurrence of cracks and cutting dust during punching of the polarizing plate can be reduced .

Generally, the cycloolefin-based resin is a hydrophobic resin, and when it is made into a film, it is easily separated when water is present, which is not preferable from the viewpoint of transparency, but the cycloolefin-based resin used in the present invention contains at least one hydrogen- In view of being capable of hydrogen bonding with a hydroxyl group of an alcohol or a hindered phenol compound with a hydrogen bond, transparency can be maintained even in a state containing a little water, and conversely, the film strength is improved by hydrogen bonding .

This is because the resin interacts with the hydroxyl group of the hindered phenol compound and the polar component of the surface of the silica particles in the film, thereby facilitating the interaction through water molecules in the air which is further introduced from the outside of the film system. It is presumed that the strength of the film is increased.

By adding a hindered phenol-based compound, the compound acts as an aggregation inhibitor, suppressing aggregation of silica particles in the cycloolefin-based resin film, and controlling the secondary particle diameter of the silica particles in the film to an appropriate range I could find out.

As the index of the interaction, the degree of hydrophobicity of the silica particles can be used as a measure. By containing a specific amount of the silica particles satisfying the specific range of the degree of hydrophobicity, the resin and the matting agent, the matting agent and the alcohol, Hindered phenol-based compounds, thereby further improving the film strength.

That is, when the degree of hydrophobicity of the silica particles is determined using a first solution of methanol and pure water at a volume ratio of 3: 7, if the degree of hydrophobicity is 20% or less, compatibility of the matting agent and the cycloolefin- In addition, in the presence of the hindered phenol-based compound, since the particles are hardly aggregated, the source of cracks is reduced. Similarly, when the degree of hydrophobicity of the silica particles is determined using a second solution having a volume ratio of methanol and pure water of 6: 4, if the degree of hydrophobicity is 80% or more, the interaction between the matting agent and the alcohol, It is presumed that the occurrence of cracks and cutting powder is reduced by reducing the generation source of cracks because the particles are less likely to agglomerate. Therefore, the polarizing plate using the film can suppress the occurrence of problems such as cracking at the punching of the polarizing plate and generation of cutting powder.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing an example of a dope preparing step, a fusing step, a drying step and a winding step of a solution casting film-forming method preferable in the present invention.

The optical film of the present invention is an optical film containing a cycloolefin-based resin, wherein the cycloolefin-based resin is a cycloolefin-based resin having at least one hydrogen-bond-soluble group, and the film contains an alcohol-based solvent and a hindered phenol- And the degree of hydrophobicity measured by the methanol wetting method is not more than 20% when the first solution having a volume ratio of methanol to pure water of 3: 7 is used, and methanol and pure water have a volume ratio of 6 : 4 is contained in an amount of 0.1 to 2.5% by mass based on the total mass of the film, the silica particles having a degree of hydrophobicity of 80% or more when the second solution is used. It is possible to provide an optical film with reduced occurrence of cracks and cutting powder at the time of punching of the polarizing plate when used in a film.

This feature is a technical feature that is common to the invention according to any one of Claims 1 to 5.

As an embodiment of the present invention, from the viewpoint of manifesting the effect of the present invention, the secondary average particle diameter of the silica particles in the film is preferably in the range of 100 to 400 nm, and the handling property at the time of production or processing is improved, Is preferable in terms of reducing the generation of cracks and cutting powder at the time of punching.

It is preferable that the film contains the above alcoholic solvent in the range of 10 to 1000 ppm and contains the hindered phenol compound in the range of 0.1 to 0.5 mass% From the viewpoint of exhibiting the effect of the present invention to improve the film strength, it is a preferable content.

As the residual solvent component contained in the resin composition, it is preferable that water is further contained in addition to the alcohol-based solvent, and the content thereof is preferably 50 to 500 ppm. If it is 50 ppm or more, the mechanical strength and the brittleness of the obtained film are improved, but it is preferably 500 ppm or less from the viewpoint of transparency of the film. Here, water may be tap water, deionized water, ultrapure water, distilled water, and the like, but it is preferably distilled water from the viewpoint of productivity such as impurities and cost.

The film thickness d of the optical film is 5 占 퐉? D? 40 占 퐉, the in-plane retardation Ro and the thickness direction retardation Rt at the measurement wavelength of 590 nm are Ro? 5 nm and -15 nm? Nm is preferable from the viewpoint of being able to provide a polarizing plate which is lightweight and thin when used as a polarizing plate protective film and that can provide an optimum retardation as a polarizing plate for an IPS mode liquid crystal display.

Further, the optical film of the present invention is a film obtained by solution casting film-forming method, and further comprises a cycloolefin resin having at least one hydrogen-bond-soluble group, silica particles satisfying the degree of hydrophobicity, a hindered phenol- And an organic solvent including an alcohol-based solvent at a dissolution temperature in the range of 15 to 50 占 폚.

If the melting temperature is 15 캜 or higher, the resin and the additive can be sufficiently dissolved, so that a film with few foreign matters can be obtained. Further, if it is 50 DEG C or less, it is preferable from the viewpoint that the dope due to the reaction of alcohol and hindered phenol compound and the coloring of the obtained film can be suppressed, and the effect of suppressing the coloring even by adding silica particles having good affinity with alcohol .

Further, from the viewpoint of improvement of productivity, it is more preferable to use a combination of an alcoholic solvent having a hydroxy group and water.

Since water has a plurality of hydrogen-bonding co-excitons in one molecule, it can be preferably used for increasing the strength of the film. Water is preferably contained in an amount of 0.1 to 1% by mass based on the total amount of the solvent.

When the amount is more than 0.1% by mass, it is preferable because it easily interacts with the cycloolefin-based resin or silica particles containing another alcohol-based solvent or a hydrogen-bonding water-soluble group, but if it exceeds 1% by mass, the cycloolefin- It is easy to get rid of foreign matter.

Hereinafter, the present invention, its constituent elements, and modes and modes for carrying out the present invention will be described in detail. In the present application, " to " is used to mean that the numerical values described before and after the lower limit and the upper limit are included.

≪ Overview of optical film of the present invention &

The optical film of the present invention is an optical film containing a cycloolefin-based resin, wherein the cycloolefin-based resin is a cycloolefin-based resin having at least one hydrogen-bond-soluble group, and the film contains an alcohol-based solvent and a hindered phenol- And the degree of hydrophobicity measured by the methanol wetting method is not more than 20% when the first solution having a volume ratio of methanol to pure water of 3: 7 is used, and methanol and pure water have a volume ratio of 6 : 4 is used, the silica particles having a degree of hydrophobicity of 80% or more are contained in an amount of 0.1 to 2.5% by mass based on the total mass of the film.

<Methanol wetting method>

The degree of hydrophobicity of the silica particles according to the present invention can be quantified by using a solvent containing alcohol or pure water. As a method for quantifying the degree of hydrophobicity, a methanol wetting method (hereinafter referred to as &quot; MW method &quot;) is preferred. In the present invention, the degree of hydrophobicity is represented by the methanol wettability value (hereinafter referred to as &quot; MW value &quot;) required in the present method.

In the MW method, in order to quantify the hydrophobicity of the fine particles, the first solution and the second solution in which methanol and pure water are mixed are used, respectively. At this time, the mixing ratio of methanol to pure water is 3: 7 in the first solution, and is 6: 4 in the second solution. Then, the same amount of the above-mentioned fine particles is added to each solution, followed by stirring and mixing. Each of the mixed solutions is centrifuged to determine the volume of the sediment of the fine particles, and the volume of the sediment of the fine particles in the first solution is defined as tmL And the volume of sediment of the fine particles in the second solution is denoted by smL, the MW value in the first solution = (t / A) 100 (%) and the MW value in the second solution MW value = (s / A) x 100 [%]. Here, A is the volume (AmL) of silica particles added at the beginning.

[MW method]

(1) A first solution A is prepared by mixing methanol solution C and pure water D at a volume ratio of 3: 7 (for example, 60 mL of pure water D with respect to 40 mL of methanol solution C)

(2) Then, 0.2 g of the silica particle powder E and 7 ml of the first solution A are put into a 10-ml sedimentation pipe F. Then,

(3) Cover the capillary tube F and shake the fine powder E in the first solution A using a turbomixer. At this time, the condition of the turbula mixer is 30 seconds at 90 rpm.

(4) To precipitate the silica particle powder E, use a centrifuge. The condition of the centrifugal separator is 3500 rpm for 10 minutes.

(5) The sedimentation amount of the sedimented particulate powder E that can be read by the scale of the sedimentation pipe is read as volume, and the value is referred to as tmL.

(6) A second solution B is prepared by mixing the methanol solution C and the pure water D in a volume ratio of 6: 4 (for example, 40 mL of pure D for 60 mL of the methanol solution C).

(7) A precipitate of the silica particle powder E was prepared by the procedures (8) to (11) as described in (2) to (5) above using the second solution B, The sedimentation amount of the precipitated silica particle powder E is read as a volume, and the value is referred to as smL.

(12) The MW value (%) is obtained by the following formula.

MW value in the first solution = (t / A) x 100 [%]

MW value in the second solution = (s / A) x 100 [%]

Here, A is the volume (AmL) of silica particles added at the beginning.

For example, if the volume of the sediment of the fine particles obtained when the first solution A is used is 1 mL and the volume (AmL) of the silica particles added first is 5 mL,

The MW value in the first solution is = (1/5) x 100 [%], and the hydrophobicity MW value is 20%.

&Lt; Structure of the optical film of the present invention >

[1] Cycloolefin-based resin

As an embodiment of the present invention, from the viewpoint of improvement of productivity, it is preferable to include water as a solvent component, and as a completed film, it is preferable to include water.

The cycloolefin-based resin used in the present invention is a cycloolefin-based resin, which is generally a cycloolefin-based resin, since it is a resin that is a cycloolefin-based resin and is hydrophobic. It is possible to hydrogen bond with the hydroxyl group of the alcohol or with the hydroxyl group of the hindered phenol compound to maintain the transparency even if the water contains a little moisture and conversely the film strength Is improved. "Hydrogen bond accepting group" refers to a functional group that accepts a hydrogen atom when forming a hydrogen bond.

The cycloolefin resin according to the present invention is characterized by being formed of a resin composition containing at least one hydrogen-bond-soluble group.

Examples of the hydrogen-bonding accepting group include an alkoxy group having 1 to 10 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 2 to 10 carbon atoms, an allyloxycarbonyl group, a cyano group, an amide group, An imido ring-containing group, a triorganosiloxy group, a triorganosilyl group, an acyl group, an alkoxysilyl group having 1 to 10 carbon atoms, a sulfonyl-containing group, and a carboxy group. To more specifically describe these polar groups, examples of the alkoxy group include a methoxy group and an ethoxy group; Examples of the acyloxy group include arylcarbonyloxy groups such as alkylcarbonyloxy groups such as acetoxy group and propionyloxy group and benzoyloxy group; Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group and the like; Examples of the allyloxycarbonyl group include a phenoxycarbonyl group, a naphthyloxycarbonyl group, a fluorenyloxycarbonyl group, a biphenylyloxycarbonyl group and the like; Examples of the triorganosiloxy group include trimethylsiloxy group, triethylsiloxy group and the like; Examples of the triorganosilyl group include a trimethylsilyl group and a triethylsilyl group; Examples of the alkoxysilyl group include a trimethoxysilyl group and a triethoxysilyl group.

The amount of the cycloolefin-based resin containing the hydrogen-bond-soluble group contained in the resin component is not particularly limited, but the content is preferably 10 to 100% by mass. When the amount is 10% by mass or more, the resulting ring-opened copolymer is preferable because it easily exhibits solubility in a solvent such as toluene or dichloromethane. In view of solubility, strength and transparency of the film, More preferable.

Examples of the cycloolefin-based resin according to the present invention include the following (co) polymers.

Wherein p is 0 or 1, and m is 0 or an integer of 1 or more. R ¹ to R ⁴ each independently represent a hydrogen atom, a hydrocarbon group, a halogen atom, or a hydrogen-bonding water-soluble group. In addition, two or more of R ¹ to R ⁴ may combine with each other to form an unsaturated bond, a monocyclic ring or a polycyclic ring, and the monocyclic or polycyclic ring may have a double bond or may form an aromatic ring.

In the present invention, the preferred ratio of the hydrogen-bond-accepting group of the cycloolefin-based resin is preferably one to two of R ¹ to R ⁴ in the formula (I) has a hydrogen-bond-accepting group.

The retention ratio of the hydrogen-bond-accepting group of the cycloolefin-based resin can be determined using, for example, the carbon-13 nuclear magnetic resonance ( ^13C NMR) spectrum method.

In the formula (I), R ¹ and R ³ are each a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 2 carbon atoms. At least one of R ² and R ⁴ is P and m are preferably m = 1 and p = 0 from the viewpoint of high glass transition temperature and excellent mechanical strength.

Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom. Examples of the hydrocarbon group having 1 to 30 carbon atoms include alkyl groups such as methyl group, ethyl group and propyl group; A cycloalkyl group such as a cyclopentyl group and a cyclohexyl group; Alkenyl groups such as vinyl group, allyl group and propenyl group; An aromatic group such as a phenyl group, a biphenyl group, a naphthyl group, and an anthracenyl group. These hydrocarbon groups may be substituted, and examples of the substituent include halogen atoms such as a fluorine atom, a chlorine atom and a bromine atom, and a phenylsulfonyl group.

The cycloolefin resin according to the present invention preferably has a molecular weight of 0.2 to 5 cm 3 / g, more preferably 0.3 to 3 cm 3 / g, and particularly preferably 0.4 to 1.5 cm 3 / g in terms of intrinsic viscosity [η] inh, The number average molecular weight (Mn) in terms of polystyrene measured by gel permeation chromatography (GPC) is 8000 to 100000, more preferably 10000 to 80000, particularly preferably 12000 to 50000, and the weight average molecular weight (Mw) 300000, more preferably from 30000 to 250000, and particularly preferably from 40,000 to 200,000.

When the intrinsic viscosity [eta] inh, the number average molecular weight and the weight average molecular weight are in the above ranges, the cycloolefin resin has good heat resistance, water resistance, chemical resistance, mechanical properties and moldability as a cycloolefin resin film according to the present invention It becomes.

The glass transition temperature (Tg) of the cycloolefin resin according to the present invention is generally 110 占 폚 or higher, preferably 110 to 350 占 폚, more preferably 120 to 250 占 폚, particularly preferably 120 to 220 占 폚. When the Tg is 110 캜 or higher, it is preferable to use under a high temperature condition or to prevent deformation due to secondary processing such as coating and printing. When the Tg is 350 DEG C or less, deterioration of the resin due to heat during molding or molding is suppressed, which is preferable.

Commercially available products can be preferably used as the cycloolefin resins described above. Commercially available products are commercially available from JSR under the trade names of Arton G, Atton F, Atton R, and Aton RX, and they can be used .

[2] Silica particles

The optical film of the present invention prevents scratches or deterioration of conveyability when the produced film is handled and also prevents cracks and cuts during punching of the polarizing plate when the optical film is used for the protective film of the polarizing plate And contains silica particles having a specific degree of hydrophobicity in order to obtain an optical film with reduced occurrence of powder.

The silica particles according to the present invention are characterized in that the degree of hydrophobicity as measured by the methanol wetting method is not more than 20% when the first solution having a volume ratio of methanol to pure water of 3: 7 is used and the volume ratio of methanol and pure water And the hydrophobic degree when the second solution is 6: 4 is 80% or more. The degree of hydrophobicity is measured by the above-described MW method.

The silica particles are particles mainly composed of silicon dioxide. The term &quot; main component &quot; refers to a component containing at least 50% of the constituents of the particles, preferably at least 70%, more preferably at least 80%, particularly preferably at least 90%.

In addition, it is preferable to add fine particles of silicon dioxide-based particles that have been subjected to a hydrophobic treatment on the surface by an alkylation treatment, because they are good in dispersibility with respect to a solvent and can inhibit the generation of foreign matter.

The hydrophobic treatment for the silica particles is preferably an alkylation treatment. The surface of the alkylated fine particles has an alkyl group, and the number of carbon atoms of the alkyl group is preferably in the range of 1 to 20, more preferably in the range of 1 to 12, and particularly preferably in the range of 1 to 8.

The silica particles having an alkyl group in the range of 1 to 20 carbon atoms on the surface can be obtained, for example, by treating the above silicon dioxide particles with octylsilane. In addition, it has an octyl group on its surface, but it is preferably used because it is commercially available under the trade name Aerosil R805 (manufactured by Nippon Aerosil Co., Ltd.) as an example.

The average particle diameter of the primary particles of the silica particles is preferably in the range of 5 to 400 nm, more preferably in the range of 10 to 300 nm.

The average particle diameter of the secondary particles of the silica particles is preferably in the range of 100 to 400 nm, and if the average particle diameter of the primary particles is in the range of 100 to 400 nm, it is also preferable that they are contained as primary particles without aggregation Do.

&Lt; Measurement method of average particle diameter of silica particles >

The particle diameter of the silica particles in the optical film was measured by photographing a cross section of a single cut with a microtome at a suitable magnification with a scanning electron microscope (SEM) The particle diameter is measured, and an average value is obtained to obtain an average particle diameter. The particle diameter is defined as the diameter when the cross section of the particle is a circular shape, and the area when the particle other than the circular shape is converted into a circular shape.

SEM: JSM-6060LA (JEOL: Nihon Denshikushi Co., Ltd.)

Microtome: Leica EM UC6

The content of the silica particles in the film is required to be in the range of 0.1 to 2.5 mass%, preferably in the range of 0.5 to 2.0 mass%, more preferably in the range of 1.0 to 2.0 mass% And the like.

The silica particles can be preferably a commercially available product. The silica particles can be used preferably in addition to the above Aerosil R805, for example, Aerosil R972, R972V, R974, R976S, R812, R812S, RY300, 300, R202, OX50, TT600 Ltd.) and can be used.

Of these, Aerosil R805, R812, and R976S satisfy the hydrophobicity according to the present invention, so that it is preferable to improve the handling property during handling and to keep the haze of the optical film low.

In the optical film of the present invention, it is preferable that silica particles are contained, and the coefficient of dynamic friction of at least one surface is within a range of 0.2 to 1.0. The dynamic friction coefficient can be measured in accordance with &quot; JIS K7125 Plastic-Film and Sheet Friction Coefficient Test Method &quot;.

The method of adding silica particles according to the present invention may be any one of the following first to third methods, but any method may be used.

[First Addition Method]

After the solvent and the particles are mixed with stirring, dispersion is carried out using a dispersing machine, which is added to the dope and stirred to obtain a soft dope.

[Second Method of Addition]

After the solvent and the particles are mixed with stirring, dispersion is carried out using a dispersing machine to prepare a particle dispersion. Subsequently, a small amount of resin is added to the solvent, and the above-mentioned particle dispersion is added to the stirred and dissolved solution. After stirring, the mixture is added to the raw material dope solution and sufficiently mixed to obtain soft dope.

[Third Method of Addition]

A small amount of resin is added to the solvent, and after stirring and dissolution, the particles are added and dispersed using a dispersing machine. This is added to the dope and thoroughly mixed.

The silica particles contained in the completed soft dope may be contained in the regenerated film when a regenerated film is used for preparation of the dope. However, the soft dope when the film to be a raw material of the regenerated film chip is produced is not limited to the present invention .

[3] Hindered phenol compounds

Phenolic compounds are known compounds and are described, for example, in columns 12 to 14 of U.S. Patent No. 4,839,405, and include 2,6-dialkylphenol derivative compounds. As a preferable compound among these compounds, a compound represented by the following formula (A) is preferable.

In the formulas, R ₅₁ to R ₅₆ represent a hydrogen atom or a substituent. Examples of the substituent include a halogen atom (e.g., fluorine atom, chlorine atom, etc.), an alkyl group (e.g., a methyl group, an ethyl group, an isopropyl group, a hydroxyethyl group, a methoxymethyl group, a trifluoromethyl group, An aryl group (e.g., a phenyl group, a naphthyl group, a p-toluenesulfonyl group, etc.), a cycloalkyl group (e.g., a cyclopentyl group, a cyclohexyl group, An alkoxy group (e.g., methoxy group, ethoxy group, isopropoxy group or butoxy group), an aryloxy group (e.g., phenoxy group), cyano group, acyl An alkylthio group (e.g., methylthio group, ethylthio group, butylthio group, etc.), an arylthio group (e.g., phenylthio group and the like), an amino group (e.g., acetylamino group, propionylamino group, , A sulfonylamino group (e.g., methanesulfonylamino group, benzenesulfonylamino group, etc.), a ureido group (e.g., (For example, a methylcarbamoyl group, an ethylcarbamoyl group, an ethylcarbamoyl group, an ethylcarbamoyl group, an ethylcarbamoyl group, an imidazolyl group, An alkoxycarbonyl group (e.g., methoxycarbonyl group, ethoxycarbonyl group and the like), aryloxycarbonyl group (e.g., methoxycarbonyl group, ethoxycarbonyl group and the like), sulfamoyl group (e.g., ethylsulfamoyl group and dimethylsulfamoyl group) (For example, an acetyl group, a propanoyl group, a butyroyl group, etc.), a sulfonyl group (e.g., a methanesulfonyl group, a butanesulfonyl group and a phenylsulfonyl group) An amino group (e.g., methylamino group, ethylamino group or dimethylamino group), cyano group, hydroxyl group, nitro group, nitroso group, amine oxide group (e.g. pyridine- oxide group) Imide groups, etc.), disulfide groups (for example, benzene di Disulfide group, etc.), a carboxyl group, a sulfo group, a heterocyclic group (e.g., a pyrrolyl group, a pyrrolidyl group, a pyrazolyl group, an imidazolyl group, a pyridyl group, A benzothiazolyl group, a benzoxazolyl group, etc.), and the like. These substituents may be further substituted.

Also, it is preferable that R ₅₁ is a hydrogen atom, and R ₅₂ and R ₅₆ are t-butyl groups.

The hindered phenol compound according to the present invention is not particularly limited, but the following specific examples can be given.

Specific examples of the compound include n-octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate, n-octadecyl 3- 4-hydroxyphenyl) -acetate, n-octadecyl 3,5-di-t-butyl-4-hydroxybenzoate, n-hexyl 3,5- Dodecyl 3,5-di-t-butyl-4-hydroxyphenylbenzoate, neododecyl 3- (3,5-di-t- butyl- 4-hydroxyphenyl) propionate (3-hydroxy-3,5-di-t-butylphenyl) isobutyrate, octadecyl (4-hydroxy-3,5-di-t-butyl-4-hydroxyphenyl) propionate, octadecyl? - (N-octylthio) ethyl 3,5-di-t-butyl-4-hydroxy-benzoate, 2- Hydroxy-phenylacetate, 2- (n-octadecylthio) ethyl 3,5-di-t-butyl- Di-t-butyl-4-hydroxy-benzoate, 2- (n-octadecylthio) ethyl 3,5- (3,5-di-t-butyl-4-hydroxy-phenyl) propionate, 2- (n-octadecylthio) ethyl 3- Di-t-butyl-4-hydroxyphenyl) propionate, stearamide N, N-bis- [ethylene 3- (3,5- ], n-butylimino N, N-bis- [ethylene 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2- (2-stearoyloxyethylthio Ethyl-3,5-di-t-butyl-4-hydroxybenzoate, 2- (2-stearoyloxyethylthio) ethyl 7- Propylene glycol bis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], ethylene glycol bis- [3- Di-t-butyl-4-hydroxyphenyl) propionate], neopentyl glycol bis- [3- (3,5- Butyl-4-hydroxyphenyl) propionate], ethylene glycol bis- (3,5-di-t-butyl-4-hydroxyphenylacetate), glycerin-ln-octadecanoate- - (3,5-di-t-butyl-4-hydroxyphenyl acetate), pentaerythritol-tetrakis- [3- (3 ', 5'- Propionate], 1,1,1-trimethylol ethane-tris- [3- (3,5-di-t- butyl-4-hydroxyphenyl) propionate], sorbitol hexa- [3- , 5-di-t-butyl-4-hydroxyphenyl) propionate], 2-hydroxyethyl 7- Butyl [(3 ', 5'-di-t-butyl (4-methyl-5-tert- butylphenyl) heptanoate, 4-hydroxyphenyl) propionate], pentaerythritol-tetrakis (3,5-di-t-butyl-4-hydroxyhydrocinnamate) and the like.

As specific examples of the hindered phenol-based antioxidant useful therefor, the following exemplified compounds are shown, but the present invention is not limited thereto.

Further, phenolic compounds of this type are commercially available from, for example, BASF Japan, under the trade names "Irganox 1035", "Irganox 1076" and "Irganox 1010".

The amount of the phenolic compound to be added to 100 parts by mass of the cycloolefin resin can be suitably designed, but is preferably in the range of 0.1 to 1.0 part by mass, and more preferably in the range of 0.3 to 0.5 part by mass.

[4] additives, other

[4.1] Plasticizers

Examples of the plasticizer include a polyester compound, a polyhydric alcohol ester compound, a polycarboxylic acid ester compound (including a phthalic acid ester compound), a glycolate compound, and an ester compound (including a fatty acid ester compound and a phosphoric acid ester compound) . These may be used alone or in combination of two or more.

A preferred plasticizer for the optical film of the present invention is a polyester compound containing a repeating unit obtained by reacting a dicarboxylic acid with a diol.

The dicarboxylic acid constituting the polyester compound is an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid or an alicyclic dicarboxylic acid, preferably an aromatic dicarboxylic acid. The dicarboxylic acid may be one kind or a mixture of two or more kinds.

The diol constituting the polyester compound is an aromatic diol, an aliphatic diol or an alicyclic diol, preferably an aliphatic diol, more preferably a diol having 1 to 4 carbon atoms. The diol may be a single type or a mixture of two or more types.

Among them, the polyester compound preferably contains a repeating unit obtained by reacting a dicarboxylic acid containing at least an aromatic dicarboxylic acid with a diol having 1 to 4 carbon atoms. The aromatic dicarboxylic acid and the aliphatic dicarboxylic acid It is more preferable to contain a repeating unit obtained by reacting a dicarboxylic acid containing an acid with a diol having 1 to 4 carbon atoms.

Both ends of the polyester compound molecule may be sealed or not sealed, but sealed from the viewpoint of reducing the moisture permeability of the film.

The polyhydric alcohol ester compound is an aliphatic polyhydric alcohol having two or more valences and an ester compound (alcohol ester) of a monocarboxylic acid, and is preferably an aliphatic polyhydric alcohol ester having a valency of 2 to 20. The polyhydric alcohol ester compound preferably has an aromatic ring or a cycloalkyl ring in the molecule.

Preferable examples of the aliphatic polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, trimethylolpropane, Pentaerythritol, trimethylol ethane, xylitol, and the like. Among them, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylol propane, xylitol and the like are preferable.

The monocarboxylic acid is not particularly limited and may be an aliphatic monocarboxylic acid, an alicyclic monocarboxylic acid, or an aromatic monocarboxylic acid. In order to increase the moisture permeability of the film and make it difficult to volatilize, an alicyclic monocarboxylic acid or an aromatic monocarboxylic acid is preferable. The monocarboxylic acid may be one kind or a mixture of two or more kinds. Further, all of the OH groups included in the aliphatic polyhydric alcohol may be esterified, or a part thereof may be left as it is in the OH group.

The aliphatic monocarboxylic acid is preferably a linear or branched chain fatty acid having 1 to 32 carbon atoms. The carbon number of the aliphatic monocarboxylic acid is more preferably 1 to 20, and still more preferably 1 to 10. Examples of aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2- ethylhexanoic acid, But are not limited to, tridecanoic acid, tridecanoic acid, tridecanoic acid, tridecanoic acid, tridecanoic acid, tridecanoic acid, tridecanoic acid, tridecanoic acid, tridecanoic acid, tridecanoic acid, myristic acid, pentadecylic acid, palmitic acid, Saturated fatty acids such as succinic acid and lactic acid; Unsaturated fatty acids such as undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, and the like. Among them, acetic acid or a mixture of acetic acid and other monocarboxylic acids is preferable in order to improve compatibility with cellulose acetate.

Examples of the alicyclic monocarboxylic acid include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid and the like.

Examples of aromatic monocarboxylic acids include benzoic acid; 1 to 3 alkyl groups or alkoxy groups (for example, methoxy group or ethoxy group) introduced into the benzene ring of benzoic acid (for example, toluic acid and the like); Aromatic monocarboxylic acids having two or more benzene rings (for example, biphenylcarboxylic acid, naphthalenecarboxylic acid, tetralinecarboxylic acid, etc.), and preferably benzoic acid.

Specific examples of the polyhydric alcohol ester compound include the compounds described in paragraphs [0058] to [0061] of JP-A No. 2006-113239.

The polycarboxylic acid ester compound is an ester compound of a polyvalent carboxylic acid having 2 or more valences, preferably 2 to 20 valences, with an alcohol compound. The polycarboxylic acid is preferably an aliphatic polycarboxylic acid having 2 to 20 carbon atoms, an aromatic polycarboxylic acid having 3 to 20 carbon atoms, or an alicyclic polycarboxylic acid having 3 to 20 carbon atoms.

Examples of the polycarboxylic acid ester compound include triethyl citrate, tributyl citrate, acetyl triethyl citrate (ATEC), acetyl tributyl citrate (ATBC), benzoyl tributyl citrate, acetyltriphenyl citrate, Acetyl tribenzyl citrate, dibutyl tartrate, diacetyl dibutyl tartrate, tributyl trimellitate, tetrabutyl pyromellitate and the like.

Examples of glycolate compounds include alkyl phthalyl alkyl glycolates. Examples of alkyl phthalyl alkyl glycolates include methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octylphthalyl octyl glycolate, methyl phthalyl ethyl Butyl phthalyl ethyl glycolate, butyl phthalyl ethyl glycolate, ethyl phthalyl propyl glycolate, ethyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl phthalyl ethyl glycolate, Butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate, octylphthalyl methyl glycolate, octylphthalyl ethyl glycolate and the like, preferably ethyl phthalyl ethyl glycolate to be.

Examples of the ester compound include a fatty acid ester compound, a citric acid ester compound, and a phosphoric acid ester compound.

Examples of the fatty acid ester compound include butyl oleate, methyl acetyl ricinoleate, dibutyl sebacate, and the like. Examples of the citrate ester compound include acetyltrimethyl citrate, acetyltriethyl citrate, acetyl tributyl citrate, and the like. Examples of the phosphoric acid ester compound include triphenyl phosphate, tricresyl phosphate, cresyldiphenyl phosphate, octyldiphenyl phosphate, biphenyl diphenyl phosphate, trioctyl phosphate, tributyl phosphate and the like, Phosphate.

Among them, a polyester compound, a glycolate compound and a phosphoric acid ester compound are preferable, and a polyester compound is particularly preferable.

The content of the plasticizer is preferably in the range of 1 to 20 mass%, and more preferably in the range of 1.5 to 15 mass%, based on 100 mass parts of the cycloolefin-based resin. When the content of the plasticizer is within the above range, the plasticity-imparting effect can be exhibited and the plasticizer resistance to permeation of the plasticizer from the optical film is also excellent.

[4.2] Phase difference enhancer

The optical film of the present invention may contain a retardation increasing agent to adjust the retardation.

As used herein, the retardation increasing agent means a retardation value Rt (measured at a light wavelength of 590 nm) in the thickness direction of an optical film containing 3 parts by mass of the compound relative to 100 parts by mass of a cycloolefin resin, Quot; refers to a compound having a function of exhibiting a value of at least two times.

The phase difference increasing agent to be used in the present invention is not particularly limited and includes, for example, a conventionally known discotic compound (1) having an aromatic ring described in paragraphs [0143] to [0179] of JP 2006-113239 A , 3,5-triazine-based compounds, etc.), Japanese Patent Application Laid-Open No. 2006-113239, Barrier compounds described in paragraphs [0106] to [0112], Japanese Patent Application Laid-Open No. 2012-214682, paragraphs [0118] to [0188] And the like can be used.

[4.3] Ultraviolet absorber

The optical film of the present invention preferably contains an ultraviolet absorber for shielding unnecessary ultraviolet rays irradiated to a polarizing plate or a liquid crystal display device.

Examples of the ultraviolet absorber include oxybenzophenone compounds, benzotriazole compounds, salicylic ester compounds, benzophenone compounds, cyanoacrylate compounds, and nickel complex salt compounds. Among them, benzotriazole Based compound is preferable. The ultraviolet absorber described in JP-A-10-182621, JP-A-8-337574, and JP-A-6-148430 are preferably used.

When the optical film of the present invention is used as a protective film of a polarizing plate in addition to an optical compensation film, ultraviolet absorbers are preferably used because they have excellent ultraviolet ray absorbing ability at a wavelength of 370 nm or less, From the viewpoint of the property, it is preferable that it has a characteristic that absorption of visible light having a wavelength of 400 nm or more is small.

The addition amount of the ultraviolet absorber is preferably in the range of 0.1 to 5.0 mass%, more preferably in the range of 0.5 to 5.0 mass% with respect to the polymer composition.

Examples of the benzotriazole ultraviolet absorber useful in the present invention include 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'- -Butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) benzotriazole, 2- butylphenyl) -5-chlorobenzotriazole, 2- [2'-hydroxy-3 '- (3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) Benzotriazol-2-yl) phenol], 2- (2'-hydroxyphenyl) Methylphenyl) -5-chlorobenzotriazole, 2- (2H-benzotriazol-2-yl) -6- (linear and branched dodecyl) -4-methylphenol 3- [3-t-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl- Butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate, No.

TINUVIN 109, TINUVIN 171, TINUVIN 326, TINUVIN 328 (trade names, manufactured by BASF Japan) as commercial products, Can be preferably used.

[5] Manufacturing method of optical film

The method of producing an optical film of the present invention may employ a solution casting film forming method or a melt casting film forming method, but it is preferable to produce by the solution casting film forming method.

The optical film of the present invention is a film formed by a solution casting film forming method and further comprises a cycloolefin resin having at least one hydrogen-bond-soluble group, silica particles satisfying the degree of hydrophobicity, the hindered phenol compound, It is preferable to prepare a dope containing an organic solvent containing a solvent in a range of a melting temperature of 15 to 50 캜.

If the melting temperature is 15 캜 or higher, the resin and the additive can be sufficiently dissolved, so that a film with few foreign matters can be obtained. Further, if it is 50 DEG C or less, it is preferable from the viewpoint that the dope due to the reaction of alcohol and hindered phenol compound and the coloring of the obtained film can be suppressed, and the effect of suppressing the coloring even by adding silica particles having good affinity with alcohol .

The optical film of the present invention comprises a step of preparing a dope containing at least an organic solvent containing at least a cycloolefin resin, silica particles, a hindered phenol compound and an alcohol solvent, and a step (dope preparation step) (A flexible process) forming a web (also referred to as a flexible film) by being flexible on the support, a process of evaporating the solvent from the web on the support (solvent evaporation process), a process of peeling the web from the support (stripping process) (Preliminary drying step), a step of stretching the film (drawing step), a step of further drying the film after the drawing (drying step), and a step of winding the obtained optical film (winding step).

The above process will be described with reference to the drawings.

Fig. 1 is a diagram schematically showing an example of a dope preparing step, a fusing step, a drying step and a winding step of a solution casting film forming method preferable for the present invention.

The fine particle dispersion in which the solvent and the silica particles according to the present invention are dispersed by the disperser is passed from the feed kiln 41 through the filter 44 to the stock kiln 42. On the other hand, the cycloolefin resin as the main dopant is dissolved in the melting furnace 1 together with the solvent, and the fine particle dispersion liquid appropriately stored in the stock kiln 42 is added and mixed to form the main dope. The obtained main dope is filtered by the filter 6 from the filter 3 and the stock kiln 4 and the additive is added by the confluent tube 20 and mixed in the mixer 21 to be supplied to the pressure die 30 It is sent.

On the other hand, the additive (hindered phenol compound, ultraviolet absorber, phase difference enhancer, etc. according to the present invention) dissolves in the solvent and passes through the filter 12 from the additive introducing furnace 10 to the stock kiln 13 Stock. Thereafter, it is mixed with the main dope by the merging tube 20 and the mixer 21 via the filter 15 and the conduit 16.

The main dope transferred to the pressure die 30 is softened on the support 31 in the form of a metal belt to form a web 32 and is peeled off at a predetermined post-drying peeling position 33 to obtain a film. The peeled web 32 is dried until it reaches a predetermined amount of residual solvent while being passed through a plurality of conveying rollers, and then is stretched in the longitudinal direction or the width direction by the stretching device 34. After stretching, the film is dried while being passed through a conveying roller 36 until it reaches a predetermined residual solvent amount by a drying device 35, and is wound in a roll form by a winding device 37.

Hereinafter, each process will be described.

(1) Dope preparation process

The cycloolefin resin and the hindered phenol compound, and optionally the phase difference increasing agent, silica particles or other compounds are dissolved in an organic solvent mainly containing a good solvent for the cycloolefin resin in the melting furnace while stirring, Or a step of mixing the hindered phenolic compound, and optionally a phase difference increasing agent, silica particles or other compound solution, into the cycloolefin resin solution to prepare a dope as a main dissolution liquid.

When the optical film of the present invention is produced by the solution casting method, the organic solvent useful for forming the dope preferably simultaneously dissolves the cycloolefin resin, the hindered phenol compound, the retardation increasing agent and other compounds .

As the organic solvent to be used, the following solvents are preferably used.

Examples of the solvent used in the solution casting method include chlorinated solvents such as chloroform and dichloromethane; Aromatic solvents such as toluene, xylene, benzene, and mixed solvents thereof; Alcohol solvents such as methanol, ethanol, isopropanol, n-butanol and 2-butanol; Methyl cellosolve, ethyl cellosolve, butyl cellosolve, dimethyl formamide, dimethyl sulfoxide, dioxane, cyclohexanone, tetrahydrofuran, acetone, methyl ethyl ketone (MEK), ethyl acetate, diethyl ether; And the like. These solvents may be used alone or in combination of two or more.

When the solvent according to the present invention is used for the mixing of a good solvent and a poor solvent, examples of the two solvents include dichloromethane as the chlorine-based solvent and methyl acetate, ethyl acetate, amyl acetate, acetone, methyl Ethyl ketone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-hexafluoro Propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1,1,1,3,3 N-propanol, iso-propanol, n-butanol, sec-butyl alcohol, isopropanol, n-butanol, Butanol, tert-butanol, etc. Among them, dichloromethane is preferable.

The poor solvent is an alcohol solvent according to the present invention, and it is necessary for the effect of the present invention to exhibit the effect of the present invention that 10 to 1000 ppm is contained in the optical film.

The content of the alcohol-based solvent contained in the optical film of the present invention is the so-called residual solvent amount and refers to the content contained in the film after production of the film. The amount of the solvent can be quantified by headspace gas chromatography described below, and the measurement refers to a value measured after the production of the film and before the film processing. Normally, the film is stored in a quasi-sealed state after being wrapped in a protective sheet or the like after being produced and wound, and the state of the film is maintained until it is processed, so the fluctuation of the amount of the residual solvent is small. Therefore, the measurement of the amount of the residual solvent can be judged whether or not the composition of the present invention is the value obtained when the film is measured after the film production to the film processing.

The amount of the residual solvent can be controlled by the composition ratio of the solvent, the drying temperature during the film formation, the drying conditions such as the drying time, the film thickness, and the like.

The content of the alcoholic solvent contained in the optical film of the present invention is preferably in the range of 10 to 500 ppm, more preferably in the range of 20 to 200 ppm. The effect of the present invention is exhibited at 10 ppm or more, and the peelability from the metal support in the solution casting film formation is also improved. If it is 1000 ppm or less, it is preferable from the viewpoints of haze and environmental safety.

The alcohol-based solvent according to the present invention is preferably selected from methanol, ethanol and butanol from the viewpoint of improving the peelability and enabling high-speed flexibility, in addition to the effect of the present invention. Among them, ethanol is preferable in view of the above.

In the present invention, in the case of a mixed solvent, the amount of the good solvent is preferably 55 mass% or more, more preferably 70 mass% or more, and further preferably 80 mass% or more, based on the total amount of the solvent.

In the optical film of the present invention, it is more preferable to use an alcohol-based solvent having a hydroxyl group in combination with water from the viewpoint of improvement in productivity. Water is added to the dope, and water is added in an amount of 50 to 500 ppm Is preferably contained in the film within the above range.

Since water has a plurality of hydrogen-bonding co-excitons in one molecule, it can be preferably used for increasing the strength of the film. Water is preferably contained in an amount of 0.1 to 1% by mass based on the total amount of the solvent.

When the amount is 0.1% by mass or more, it is preferable because it is easy to interact with the cycloolefin-based resin or silica particles containing other alcohol solvents or hydrogen-bonding water-soluble groups. When the amount is 1% by mass or less, gelation of the cycloolefin- So that generation of foreign matter can be suppressed.

<Amount of Residual Solvent>

The residual amount of the alcohol and water used as a solvent component is measured by the following method.

The optical film cut into a predetermined shape was placed in a 20 mL sealed glass container and treated at 120 DEG C for 20 minutes and then subjected to gas chromatography (apparatus: HP 5890 SERIES II, column: DB-WAX (inner diameter 0.32 mm, length 30 m) , Detection: FID), and the temperature was raised to 100 DEG C at 80 DEG C / min after holding the GC temperature elevation condition at 40 DEG C for 5 minutes.

The method of dissolving the cycloolefin resin and the hindered phenol compound, and optionally the phase difference increasing agent and other compounds, may be carried out at normal pressure, a method performed at the boiling point of the main solvent or a method of performing pressurization at a boiling point or more of the main solvent , Japanese Unexamined Patent Publication No. 9-95544, Japanese Unexamined Patent Application, First Publication No. 9-95557 or Japanese Unexamined Patent Application, First Publication No. Hei 9-95538, Japanese Unexamined Patent Publication No. 11-21379 At a high pressure as described in JP-A-11-178696. However, it is preferable to conduct the reaction in the range of 0.8 to 4 MPa from the viewpoint of solubility.

The concentration of the cycloolefin resin in the dope is preferably in the range of 10 to 40 mass%. A compound is added to the dope during or after dissolution, dissolved and dispersed, filtered with a filter medium, defoamed, and sent to the next step by a liquid delivery pump.

For dope filtration, it is preferable to filter the dope with, for example, a filter medium having a 90% collected particle diameter of 10 to 100 times the average particle diameter of the fine particles, with a main filter 3 having a leaf disc filter desirable.

In the present invention, it is preferable that the filtration material used for filtration has a small absolute filtration accuracy. However, if the absolute filtration precision is too small, the filtration material tends to be clogged and the exchange of the filter material must be frequently performed, .

Therefore, in the present invention, the filter material used in the cycloolefin resin-containing dope preferably has an absolute filtration accuracy of 0.008 mm or less, more preferably 0.001 to 0.008 mm, and more preferably 0.003 to 0.006 mm More preferable.

The material of the filter medium is not particularly limited and a normal filter medium can be used. However, a filter material made of plastic fibers such as polypropylene or Teflon (registered trademark) or a metal filter material made of stainless steel fiber is preferable.

In the present invention, it is preferable that the flow rate of the dope at the time of filtration is 10 to 80 kg / (h · m 2), preferably 20 to 60 kg / (h · m 2). If the flow rate of the dope at the time of filtration is 10 kg / (h · m 2) or more, efficient productivity is obtained. If the flow rate of the dope at the time of filtration is 80 kg / (h · m 2) or less, , So that the filter medium is not damaged.

The filtration pressure is preferably 3500 kPa or less, more preferably 3000 kPa or less, and still more preferably 2500 kPa or less. The filtration pressure can be controlled by appropriately selecting the filtration flow rate and the filtration area.

In many cases, the main dope may contain about 10 to 50 mass% of recovered scrap.

The recovered scrap is, for example, an optical film obtained by finely grinding an optical film. The recovered scrap is obtained by cutting off both side portions of the film, which is generated when the optical film is formed, or by using an optical film fabric exceeding a predetermined value do.

As the raw material for the resin used in the dope preparation, pellets of a cycloolefin resin and other compounds may be preferably used.

(2) Flexible process

(2.1) Flexibility of dope

An endless metal supporting body 31 for feeding the dope to the pressure die 30 through a feed pump (for example, a pressurized metering gear pump) and infinitely feeding it, for example, a stainless steel belt or a rotating metal drum In a flexible position on a metal support of a press die slit.

The metal support in the casting step is preferably mirror-finished on the surface, and as the metal support, a stainless steel belt or a drum finished by plating the cast iron surface is preferably used. The width of the cast may be in the range of 1 to 4 m, preferably in the range of 1.3 to 3 m, more preferably in the range of 1.5 to 2.8 m. The surface temperature of the metal support of the flexible process is set to a range of -50 ° C to a temperature at which the solvent does not boil up to foam, more preferably -30 to 0 ° C. The higher temperature is preferable because it can speed up the drying speed of the web (the dope formed by softly dope the dope on the flexible metal support). However, when the temperature is too high, the web may be foamed or the planarity may deteriorate. A suitable support temperature is appropriately determined at 0 to 100 캜, more preferably in the range of 5 to 30 캜. Alternatively, it is preferable that the web be gelled by cooling to peel off the drum in a state containing a large amount of residual solvent.

A method of controlling the temperature of the metal support is not particularly limited, but there is a method of blowing hot air or cold air, or a method of bringing hot water to the side of the metal support. The use of hot water is preferable because the heat transfer is performed efficiently and the time until the temperature of the metal support becomes constant is short. In the case of using hot wind, warm winds above the boiling point of the solvent are used in consideration of the temperature drop of the web due to the latent heat of evaporation of the solvent, and winds at a temperature higher than the target temperature may be used while preventing foaming. Particularly, it is preferable to change the temperature of the support body and the temperature of the drying wind during the period from the time of pouring to the time of peeling, so as to efficiently perform drying.

The die is preferably a press die which can adjust the shape of the slit of the die-clamping portion of the die and makes the film thickness uniform. The pressure die includes a coated hanger die and a T die, all of which are preferably used. The surface of the metal support is mirror-finished. Two or more pressure dies may be provided on the metal support to increase the film forming speed and the doping amount may be divided and laminated.

(2.2) Solvent evaporation process

Heating the web on a flexible metal support to evaporate the solvent, and controlling the amount of the residual solvent at the time of peeling, which will be described later.

In order to evaporate the solvent, there are a method of blowing air from the web side, a method of heating by the liquid from the back side of the support, and a method of transferring heat from the front and back by radiant heat. . Also, a method of combining them is also preferably used. It is preferable to dry the web on the supporter after the softening on the supporter in an atmosphere of 30 to 100 캜. In order to maintain the atmosphere at 30 to 100 占 폚, it is preferable to warm the warm air at this temperature to the upper surface of the web or to heat it by means of infrared rays or the like.

From the standpoint of surface quality, moisture permeability and releasability, it is preferable to peel the web from the support within 30 to 180 seconds.

(2.3) Peeling process

And peeling the web from which the solvent has evaporated on the metal support at the peeling position. The peeled web is sent to the next process as a film.

The temperature at the peeling position on the metal support is preferably in the range of 10 to 40 占 폚, and more preferably in the range of 11 to 30 占 폚.

In the present invention, the solvent in the web is evaporated in the solvent evaporation step, and the amount of the residual solvent of the web on the metal support at the time of peeling is preferably within a range of 15 to 100 mass%. The control of the residual solvent amount is preferably carried out by the drying temperature and drying time in the solvent evaporation step.

When the amount of the residual solvent is 15 mass% or more, silica particles are preferably dispersed uniformly in the film without having a distribution in the thickness direction in the drying process on the support.

When the amount of the residual solvent is 100% by mass or less, the film has self-supporting property, the peeling failure of the film can be avoided, the mechanical strength of the web can be maintained, It is possible to suppress the occurrence of sweeping and vertical streaks due to the presence of the liquid.

The residual solvent amount of the web or film is defined by the following formula (Z).

The formula (Z)

(%) = (Mass of the web or film before the heat treatment - mass after heat treatment of the web or film) / (mass after heat treatment of the web or film) 占 100

The heat treatment at the time of measuring the residual solvent amount means that the heat treatment is performed at 115 캜 for one hour.

When the web is peeled off from the metal support to form a film, the peeling tension is usually in the range of 196 to 245 N / m, but in the case where wrinkles tend to occur at peeling, peeling is preferably carried out with a tension of 190 N / m or less.

In the present invention, the temperature at the peeling position on the metal support is preferably within the range of -50 to 40 占 폚, more preferably in the range of 10 to 40 占 폚, and most preferably within the range of 15 to 30 占 폚 desirable.

(3) Drying and drawing process

The drying step may be divided into a preliminary drying step and a main drying step.

(3.1) Pre-drying process

The film obtained by peeling the web from the metal support is pre-dried. The film may be preliminarily dried by conveying the film by a plurality of rollers disposed above and below, or may be dried while being conveyed while fixing both ends of the film with a clip such as a tenter dryer.

The means for drying the web is not particularly limited and generally can be performed by hot air, infrared rays, heating rollers, microwaves or the like.

The drying temperature in the preliminary drying step of the web is preferably at most -5 deg. C, and preferably at least 30 deg. C for 1 minute to 30 minutes. The drying is carried out within the range of 40 to 150 ° C, more preferably within the range of 50 to 100 ° C.

(3.2) Drawing process

The optical film of the present invention can be obtained by uniformly dispersing the silica particles in the resin in the film, improving the planarity of the film, or orienting the molecules in the film by performing stretching treatment with the stretching device 34 in the residual solvent amount The desired phase difference values Ro and Rt can be obtained.

In the process for producing an optical film of the present invention, it is preferable that the amount of the residual solvent at the start of the stretching is 1% by mass or more and less than 15% by mass in the step of stretching the film. More preferably in the range of 2 to 10% by mass, and if the amount of the residual solvent is in the range, uneven stress can be prevented from being applied to the film at the time of stretching.

The optical film of the present invention is preferably stretched in the longitudinal direction (also referred to as the MD direction or the flexible direction) and / or the width direction (also referred to as the TD direction) and / or the oblique direction, And the like.

The stretching operation may be divided into multiple steps. In the case of biaxial stretching, simultaneous biaxial stretching may be performed, or may be performed stepwise. In this case, the stepwise means that, for example, the stretching in which the stretching directions are different can be sequentially performed, the stretching in the same direction can be divided into multiple steps, and the stretching in different directions can be added to any stage.

That is, for example, the following stretching steps are possible:

Stretching in the longitudinal direction Stretching in the width direction Stretching in the longitudinal direction Stretching in the longitudinal direction

Stretching in the width direction Stretching in the width direction Stretching in the longitudinal direction Stretching in the longitudinal direction

Stretching in the width direction Stretching in the oblique direction

The simultaneous biaxial stretching may include stretching in one direction and shrinking the other by relaxing the tension.

The optical film of the present invention preferably has a glass transition temperature (Tg + 5) to a glass transition temperature (Tg) in a longitudinal direction and / or a width direction, preferably a width direction, Tg + 50) 占 폚. If the stretching is carried out in the above-mentioned temperature range, the retardation can be easily adjusted and the stretching stress can be lowered, and the haze is lowered. In addition, the occurrence of breakage is suppressed, and an optical film excellent in planarity and colorability of the film itself can be obtained. The stretching temperature is preferably in the range of (Tg + 10) to (Tg + 40) deg.

Here, the glass transition temperature Tg is the midpoint glass transition temperature (Tmg) measured according to JIS K7121 (1987), which is measured using a commercially available differential scanning calorimeter at a heating rate of 20 캜 / min. The specific glass transition temperature Tg of the optical film is measured by using a differential scanning calorimeter DSC220 manufactured by Seiko Instruments Inc. according to JIS K7121 (1987).

In the optical film of the present invention, it is preferable that the film is stretched at least in the width direction at an elongation in the range of 5 to 40% with respect to the original width, and in the longitudinal direction and the width direction of the film, It is more preferable to stretch at an elongation in the range. In particular, it is more preferable that the stretching ratio is within a range of 10 to 30% with respect to the original width. Within the above range, in particular, when a retardation increasing agent is included, not only a desired retardation value is obtained but also the film can be made thinner. The term "elongation" in the present invention refers to the ratio (%) of the length of the film before stretching or the length of the film in the width direction after stretching to the length of the width.

The method of stretching in the longitudinal direction is not particularly limited. For example, there are a method in which a peripheral speed difference is generated in a plurality of rolls and a longitudinal direction is elongated using a roll speed difference therebetween, a method in which both ends of the web are fixed with clips or pins, A method of stretching in the machine direction in the longitudinal direction and a method of stretching in the machine direction in both the longitudinal and lateral directions. Of course, these methods and the like may be used in combination.

In order to stretch in the width direction, for example, the entire drying step or a part of the steps as disclosed in Japanese Patent Application Laid-Open No. 62-46625 may be carried out by using a clip or pin in the width direction Method (called a tenter method), a tenter method using a clip among them, and a pin tenter method using a pin are preferably used.

When stretching in the width direction, stretching at a stretching speed of 250 to 500% / min in the film width direction is preferable from the viewpoint of improving the planarity of the film.

When the stretching speed is 250% / min or more, the planarity is improved and the film can be processed at a high speed. Therefore, it is preferable from the viewpoint of production suitability. If the stretching speed is 500% / min or less, .

The preferred stretching speed is in the range of 300 to 400% / min, and is effective at the time of stretching at a low magnification. The stretching speed is defined by the following equation (1).

(% / Min) = [(d ₁ / d ₂ ) -1] × 100 (%) / t

(D ₁ is the width dimension of the optical film of the present invention after stretching in the stretching direction, d ₂ is the width dimension in the stretching direction of the optical film before stretching, and t is the time required for stretching min)

The optical film of the present invention can impart a desired retardation value by stretching.

The film thickness of the optical film of the present invention is 5 占 퐉? D? 40 占 퐉 and the in-plane retardation Ro and the thickness direction retardation Rt at the measurement wavelength of 590 nm are Ro? 5 nm, -15 nm? Is used as a polarizing plate protective film, it is possible to provide a light polarizing plate which is thin and thin, and it is also preferable from the viewpoint that an optimal retardation can be given as a polarizing plate for an IPS mode liquid crystal display.

The in-plane retardation value Ro and the retardation value Rt in the thickness direction were measured at a wavelength of 590 nm under an environment of 23 占 폚 and 55% RH using an automatic birefringence index liquid scan (Axo Scan Mueller Matrix Polarimeter, , The three-dimensional refractive index can be measured, and the refractive indices n _x , n _y , and n _z can be calculated.

Formula (i): Ro = (n x -n y) × d (㎚)

Formula (ii): Rt = {( n x + n y) / 2-n z} × d (㎚)

[In the formulas (i) and (ii), n _x represents the refractive index in the direction x at which the refractive index becomes maximum in the in-plane direction of the film. n _y represents the refractive index in the direction y perpendicular to the direction x in the in-plane direction of the film. n _z represents the refractive index in the thickness direction z of the film. d represents the thickness (nm) of the film]

In the stretching step, usually, after stretching, the retention and relaxation are performed. That is, in this step, it is preferable to perform the stretching step for stretching the film, the holding step for holding the film in the stretched state, and the relaxation step for relaxing the film in the stretching direction in this order. In the holding step, the stretching at the elongation rate achieved in the stretching step is maintained at the stretching temperature in the stretching step. In the relaxation step, the stretching in the stretching step is maintained in the holding step, and then the tension for stretching is released to relax the stretching. The relaxation step may be performed at a temperature not higher than the stretching temperature in the stretching step.

(3.3) Drying process

In the drying step, the film after stretching is heated by the drying device 35 and dried.

In order to adjust the amount of the organic solvent contained in the optical film, it is preferable to adjust the conditions of the drying step appropriately.

When the film is heated by hot air or the like, a nozzle capable of exhausting used hot air (air containing solvent or moisture containing air) is provided, and means for preventing the mixing of hot air that has been used is also preferably used. The hot air temperature is more preferably in the range of 40 to 350 占 폚. The drying time is preferably about 5 seconds to 60 minutes, more preferably 10 seconds to 30 minutes.

The heating and drying means is not limited to hot air. For example, infrared ray, heating roller, microwave, or the like can be used. From the viewpoint of simplicity, it is preferable that drying is carried out with hot air while conveying the film with the conveying roller 36 arranged in a zigzag form. The drying temperature is more preferably in the range of 40 to 350 占 폚 in consideration of the amount of the residual solvent, the expansion / contraction ratio in the transportation, and the like.

In the drying step, it is preferable to dry the film until the amount of the residual solvent is generally 0.5% by mass or less.

(4) Coiling process

(4.1) Knurling process

After a predetermined heat treatment or cooling treatment, it is preferable to provide a slitter before winding to cut the end portion to obtain a good winding shape. It is preferable to perform knurling on both ends of the width.

The knurling can be formed by pressing a heated embossing roller against the film width end portion. The embossing rollers are formed with recesses and protrusions, and by pressing the recesses and protrusions, irregularities can be formed on the film and the edges can be inflated.

The knurling height at both ends of the width of the optical film of the present invention is preferably in the range of 4 to 20 탆 and in the range of 5 to 20 mm in width.

(4.2)

As another means for obtaining a good wrapping shape, a masking film (also referred to as a protect film) may be rolled up and wound at the same time for the purpose of preventing blocking between the films before winding, and at least one of the stretching films, Tape or the like may be wound while being stuck together. The masking film is not particularly limited as long as it can protect the film, and examples thereof include a polyethylene terephthalate film, a polyethylene film and a polypropylene film.

Further, in the present invention, it is preferable that the knurling is provided before drying and after winding in the film-forming step of the film.

(4.3) Winding process

The amount of the residual solvent in the film is 2% by mass or less, and then the film is wound as a film. By setting the residual solvent amount to 1% by mass or less, a film having good dimensional stability can be obtained.

As the winding method, a generally used one may be used, such as a static torque method, a constant tension method, a taper tension method, and a program tension control method with a constant internal stress, and they may be used separately.

[6] Properties of optical film

<Hayes>

The optical film of the present invention preferably has a haze of less than 1%, more preferably less than 0.5%. When the haze is less than 1%, the transparency of the film becomes higher and it is advantageous to be more easily used as a film for optical use. Since the silica particles having a uniform particle diameter are dispersed in the optical film of the present invention, the degree of light scattering by the particles is low and the transparency is excellent.

The haze value was measured at 10 points at equal intervals in the film width direction by a haze meter (NDH2000, manufactured by Nippon Denshoku Kogyo Co., Ltd.) under the environment of 23 占 폚 and 50% RH, .

<Equilibrium moisture content>

The optical film of the present invention preferably has an equilibrium moisture content of 4% or less at 25 캜 and a relative humidity of 60%, and more preferably 3% or less. By setting the equilibrium moisture content to 4% or less, it is preferable because it is easy to cope with humidity change and optical properties and dimensions are hardly changed.

The equilibrium moisture content was determined by allowing the sample film to stand in a room humidity-conditioned at 23 占 폚 and 20% RH for 4 hours or more, then left in a room humidity-conditioned at 23 占 폚 and 80% RH for 24 hours, (CA-20 type, manufactured by Mitsubishi Chemical Corporation) is used to dry and vaporize water at a temperature of 150 占 폚, and then quantified by the Karl Fischer method.

&Lt; Film length, width, film thickness >

The optical film of the present invention is preferably long, and specifically, it is preferably a length of about 100 to 10000 m, and is wound in a roll form. The width of the optical film of the present invention is preferably 1 m or more, more preferably 1.3 m or more, and particularly preferably 1.3 to 4 m.

The film thickness of the stretched film is preferably in the range of 5 to 40 mu m from the viewpoints of the thickness reduction of the display device and the productivity. When the film thickness is 5 占 퐉 or more, a film strength or phase difference of a certain level or more can be exhibited. When the film thickness is 40 占 퐉 or less, a desired retardation is provided and the present invention can be applied to the thinning of polarizing plates and display devices. Preferably, the film thickness of the film is in the range of 10 to 30 mu m.

[7] Application of optical film

The optical film of the present invention is preferably a functional film used for various display devices such as a liquid crystal display device and an organic EL display device or a touch panel. Specifically, the optical film of the present invention can be used as a polarizing plate protective film, a retardation film, an antireflection film, a luminance enhancement film, a hard coating film, an antiglare film, an antistatic film, Optical compensation film, and the like. Typically, the optical film of the present invention is a polarizer protective film. The optical film of the present invention may be used as a polarizing plate protective film also serving as the retardation film.

[7.1] Polarizer

[7.1.1] Polarizer

The polarizer is an element that allows only light of a polarization plane in a certain direction to pass, and examples thereof include a polyvinyl alcohol polarizing film.

The polyvinyl alcohol polarizing film includes a polyvinyl alcohol film stained with iodine and a dichroic dye stained.

The polarizer can be obtained by uniaxially stretching a polyvinyl alcohol film and then dyeing it, or by uniaxially stretching a polyvinyl alcohol film after dyeing it, preferably by further performing a durability treatment with a boron compound.

The film thickness of the polarizer is preferably in the range of 5 to 30 mu m, more preferably in the range of 5 to 15 mu m.

Examples of the polyvinyl alcohol film include those having an ethylene unit content of 1 to 4% by mole, a degree of polymerization of 2000 to 4000, and a degree of saponification of 99.0 to 99.99% by mole as described in JP-A-2003-248123 and JP-A-2003-342322 Ethylene-modified polyvinyl alcohol is preferably used. In addition, it is preferable to manufacture a polarizer by bonding it to the optical of the present invention by the method described in Japanese Patent Laid-Open Nos. H11-100161, Japanese Patent No. 4691205, and Japanese Patent 4804589.

[7.1.2] Adhesive

[Waterhouse]

In the polarizing plate used in the present invention, it is preferable that the optical film of the present invention is bonded to the polarizer using a fully saponified polyvinyl alcohol aqueous solution (water-soluble). Another polarizing plate protective film can be bonded to the other side. When the optical film of the present invention is formed into a liquid crystal display device, it is preferably formed on the side of the liquid crystal cell of the polarizer, and the film outside the polarizer can use either the optical film of the present invention or the conventional polarizer protective film .

For example, as a conventional polarizing plate protective film, commercially available cellulose ester films (for example, Konica Minolta Tact KC8UX, KC5UX, KC8UCR3, KC8UCR4, KC8UCR5, KC8UY, KC6UY, KC6UA, KC4UY, KC4UE, KC8UY, KC8UXW-RHA-NC, KC8UXW-RHA-C, KC8UXW-RHA-NC, KC8UXW-RHA-NC) are preferably used.

[Active Energy ray curable adhesive]

In the polarizing plate used in the present invention, it is preferable that the optical film of the present invention and the polarizer are bonded by an active energy ray curable adhesive.

As the active energy ray curable adhesive, it is preferable to use the following ultraviolet curing type adhesive.

In the present invention, by applying an ultraviolet curable adhesive to the bonding of the optical film and the polarizer, a polarizing plate having high strength and excellent planarity can be obtained even if it is a thin film.

&Lt; Composition of ultraviolet curable adhesive >

As the ultraviolet curable adhesive composition for a polarizing plate, there are known a photo-radical polymerizable composition using photo-radical polymerization, a photo-cationic polymerizable composition using photo-cation polymerization, and a hybrid-type composition using both photo radical polymerization and photo cationic polymerization.

Examples of the photo-radical polymerization type composition include compositions containing a radical polymerizing compound containing a polar group such as a hydroxyl group or a carboxyl group and a radical polymerizing compound not containing a polar group in a specific ratio as described in JP-A-2008-009329 It is known. In particular, the radical polymerizing compound is preferably a compound having a radically polymerizable ethylenic unsaturated bond. Preferable examples of the compound having a radically polymerizable ethylenically unsaturated bond include a compound having a (meth) acryloyl group. Examples of the compound having a (meth) acryloyl group include N-substituted (meth) acrylamide-based compounds, (meth) acrylate-based compounds and the like. (Meth) acrylamide means acrylamide or methacrylamide.

As the photo cationic polymerization type composition, there may be mentioned (a) a cationic polymerizable compound, (?) A photo cationic polymerization initiator, (?) A A photosensitizer exhibiting maximum absorption in light, and an ultraviolet curable adhesive composition containing each component of (?) Naphthalene-based photo-sensitization assistant. However, an ultraviolet curable adhesive other than these may be used.

(1) Pretreatment process

The pretreatment step is a step of performing an adhesion facilitating treatment on the adhesion surface of the optical film to the polarizer. Examples of the adhesion facilitating treatment include corona treatment and plasma treatment.

(Application step of ultraviolet curing type adhesive)

In the application step of the ultraviolet curable adhesive, the ultraviolet curable adhesive is applied to at least one of the bonding surfaces of the polarizer and the optical film. When the ultraviolet curable adhesive is directly applied to the surface of the polarizer or the optical film, the application method is not particularly limited. For example, various wet coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used. It is also possible to use a method in which an ultraviolet curable adhesive is poured between the polarizer and the optical film, and then the film is uniformly spread by pressing with a roller or the like.

(2) Bonding process

After the ultraviolet curing type adhesive is applied by the above method, it is treated in the bonding step. In this bonding step, for example, when an ultraviolet curable adhesive is applied to the surface of the polarizer in the preceding coating step, the optical film is superimposed thereon. In the case of a method of first applying an ultraviolet curable adhesive to the surface of an optical film, a polarizer is superposed thereon. When an ultraviolet curable adhesive is poured between the polarizer and the optical film, the polarizer and the optical film are superimposed in this state. Normally, in this state, the optical film side of both sides is pressed and pressed by a pressure roller or the like. As the material of the pressure roller, metal or rubber can be used. The pressure rollers disposed on both sides may be the same material or different materials.

(3) Curing process

In the curing step, ultraviolet rays are irradiated to an uncured ultraviolet curable adhesive to form a cationic polymerizable compound (for example, an epoxy compound or an oxetane compound) or a radical polymerizable compound (for example, an acrylate compound or an acrylamide compound Compound, etc.) is cured, and the polarizer and the optical film are superimposed on each other with the ultraviolet curing adhesive interposed therebetween. When the optical film is bonded to one surface of the polarizer, the active energy ray may be irradiated from either the polarizer side or the optical film side. When the optical films are bonded to both surfaces of the polarizer, it is advantageous to simultaneously cure the ultraviolet curable adhesives on both sides by irradiating ultraviolet rays in a state in which the optical films are superposed on both surfaces of the polarizer with the ultraviolet curable adhesive interposed therebetween.

The irradiation condition of the ultraviolet ray may be any suitable condition as long as it is a condition capable of curing the ultraviolet curable adhesive applied in the present invention. The irradiation amount of the ultraviolet ray is preferably in the range of 50 to 1500 mJ / cm2, more preferably in the range of 100 to 500 mJ / cm2 in terms of accumulated light quantity.

When the production process of the polarizing plate is performed in a continuous line, the line speed varies depending on the curing time of the adhesive, but is preferably in the range of 1 to 500 m / min, more preferably in the range of 5 to 300 m / min, 10 to 100 m / min. When the line speed is 1 m / min or more, productivity can be ensured, or the damage to the optical film can be suppressed, and a polarizer excellent in durability can be manufactured. When the line speed is 500 m / min or less, curing of the ultraviolet curing type adhesive becomes sufficient, and the ultraviolet curing type adhesive layer having the desired hardness and having excellent adhesiveness can be formed.

[7.1.3] Protective Film

The film disposed on the opposite side to the optical film of the present invention is preferably a film that functions as a protective film of the polarizer.

As the protective film, the optical film of the present invention may be used. For example, a commercially available cellulose ester film (for example, Konica Minolta Tact KC8UX, KC5UX, KC4UX, KC8UCR3, KC4SR, KC4BR, KC4CR, KC4DR, KC4FR, KC4KR KC8UY, KC6UY, KC4UY, KC4UE, KC8UE, KC8UY-HA, KC2UA, KC4UA, KC6UAKC, 2UAH, KC4UAH, KC6UAH and above Fuji Tach T40UZ, Fuji Tach T60UZ, Fuji Tach T80UZ, Fuji Tach TD80UL , Fuji Tack TD60UL, Fuji Tack TD40UL, Fuji Tack R02, Fuji Tack R06, manufactured by Fuji Film Co., Ltd.) can be preferably used.

Also, it is also possible to use resin films such as polyethylene terephthalate, polyethylene naphthalate and polycarbonate, alicyclic polyolefins (for example, Zeonoa (registered trademark) manufactured by Nippon Zeon Co., Ltd., polyarylate, , Polysulfone, cycloolefin copolymer, polyimide (for example, Mitsubishi Kagaku Kabushiki Kaisha Neoprim TM), fluorene ring-modified polycarbonate, alicyclic modified polycarbonate, acryl (In the brackets indicate the glass transition temperature Tg). Among these resin bases, polyethylene terephthalate (abbreviated as &quot; PET &quot;), polybutylene terephthalate , Polyethylene naphthalate (abbreviated as PEN) and polycarbonate (abbreviated as PC) are preferably used as a protective film.

The thickness of the protective film is not particularly limited but may be about 10 to 200 mu m, preferably 10 to 100 mu m, and more preferably 10 to 70 mu m.

[7.2] Liquid crystal display

By using the polarizing plate to which the optical film of the present invention is bonded to the liquid crystal display device, a liquid crystal display device having excellent visibility can be manufactured.

Further, the optical film of the present invention is preferably used for a polarizing plate for use in a display having a polygonal or curved line, and when the punching is performed with a preform, cracks such as cracks or cracks are generated on the end faces, Can be solved easily.

The polarizing plate used in the present invention can be used in liquid crystal display devices of various driving methods such as STN, TN, OCB, HAN, VA (MVA, PVA), IPS and OCB. Preferably a VA (MVA, PVA) type liquid crystal display device and an IPS type liquid crystal display device.

Two polarizing plates, that is, a polarizing plate on the viewer's side and a backlight side, are usually used for the liquid crystal display, but it is also preferable to use the polarizing plate used in the present invention as both polarizing plates. In particular, it is preferable that the polarizing plate used in the present invention is used as a polarizing plate on the side of the viewer who directly contacts the external environment. When the optical film of the present invention is a protective film, , It is preferable to be disposed on the liquid crystal cell side. When it is used as an optical compensation film of an IPS liquid crystal display device, it is preferably disposed on both sides of the liquid crystal cell.

In this case, both sides of the polarizer can be coated with a commercially available cellulose ester film (for example, Konica Minolta Tact KC8UX, KC5UX, KC4UX, KC8UCR3, KC4SR , KC4BR, KC4CR, KC4DR, KC4FR, KC4KR, KC8UY, KC6UY, KC4UY, KC4UE, KC8UE, KC8UY-HA, KC2UA, KC4UA, KC6UA, KC2UAH, KC4UAH, KC6UAH and above. Fujikata T40UZ, Fuji Fuji Tack TD60UL, Fuji Tack TD40UL, Fuji Tag R02, Fuji Tag R06, manufactured by Fuji Photo Film Co., Ltd.) are preferably used as the polarizing plate.

As the polarizing plate on the backlight side, the optical film of the present invention may be used on the liquid crystal cell side of the polarizer, and the protective film, retardation film, polyester film, acrylic film, polycarbonate film, A polarizing plate to which an olefin film is bonded may also be preferably used.

By using the polarizing plate used in the present invention, it is possible to obtain a liquid crystal display device having excellent visibility such as display unevenness, frontal contrast, and the like, even if it is a liquid crystal display of a large screen having a screen of 30 inches or more.

[7.3] Organic Electroluminescence Display Device

The optical film using the cycloolefin-based resin of the present invention is suitable for an organic electroluminescence display device having high curvature and high curvature, for example, a curved surface.

As an outline of the organic EL element applicable to the organic electroluminescence display device used in the present invention, for example, Japanese Patent Laid-Open Publication No. 2013-157634, Japanese Laid-Open Patent Application No. 2013-168552, Japanese Patent Laid- 2013-177361, 2013-187211, 2013-191644, 2013-191804, 2013-225678, and Japanese Patent Application Laid-Open 2013-235994, 2013-243234, 2013-243236, 2013-242366, 2013-243371, and Japanese Patent Application Laid-Open 2013-245179, 2014-003249, 2014-003299, 2014-013910, 2014-017493, and Japanese Patent Application Laid-Open Publication No. 2014-017494 On can be given a configuration that is described.

[Example]

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto. In the examples, "part" or "%" is used, and unless otherwise stated, "part by mass" or "% by mass" is used.

&Lt; Production of optical film 101 >

(Synthesis of cycloolefin-based resin P)

75% by mass of 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.12,5.17,10] -3-dodecene (DNM), 24% by mass of dicyclopentadiene (DCP), 2-norbornene 1 , 9 parts of 1-hexene as a molecular weight modifier, and 200 parts of toluene were placed in a nitrogen-purged reaction vessel and heated to 110 ° C. 0.005 part of triethylaluminum and 0.005 part of methanol-denatured WCl6 (methanol anhydride: PhPOCl 2: WCl 6 = 103: 630: 427 mass ratio) were added and reacted for 1 hour to obtain a polymer. A solution of the obtained polymer was placed in an autoclave, and 200 parts of toluene was further added. Subsequently, 0.006 part of RuHCl (CO) [P (C ₆ H ₅ )] ₃ as a hydrogenation catalyst was added and heated to 90 ° C., and then hydrogen gas was introduced into the reactor to make the pressure 10 MPa. Thereafter, the reaction was carried out at 165 DEG C for 3 hours while maintaining the pressure at 10 MPa. After completion of the reaction, the reaction product was precipitated in a large amount of a methanol solution, and the precipitate was reprecipitated using toluene and methanol to obtain a copolymer P.

The copolymer P had a weight average molecular weight (Mw) of 7.2 x 10 ⁴ , a molecular weight distribution (Mw / Mn) of 3.3, an intrinsic viscosity (eta inh) of 0.59 as measured by gel permeation chromatography (GPC) ) = 143 [deg.] C. Further, the methoxycarbonyl group addition ratio of the copolymer P was determined by ^{13 C} NMR measurement, and it was confirmed that 75 mass% of a monomer having a methoxycarbonyl group was added. The copolymer P thus obtained is a cycloolefin resin P having 75% by mass of a monomer having a methoxycarbonyl group as a hydrogen-bond-accepting group.

(Preparation of fine particle dispersion)

11 mass% of silica fine particles (Aerosil R812 manufactured by Nippon Aerosil Co., Ltd.)

89% by mass of dichloromethane

The resulting mixture was stirred in a dissolver for 50 minutes, and then dispersed using a Mannitol dispersing machine to prepare a fine particle dispersion.

(Preparation of fine particle addition liquid 1)

Dichloromethane was added to the dissolution tank, and the prepared fine particle dispersion was slowly added thereto while sufficiently stirring the dichloromethane. Further, the particles were dispersed in the attritor so that the particle diameter of the secondary particles became a predetermined value. This was filtered with Finetmet NF (manufactured by Nippon Seisen Co., Ltd.) to prepare a fine particle addition liquid 1.

(Preparation of Dope A)

The synthesized cycloolefin resin P was added to a pressurized dissolution tank containing ethanol while stirring. Subsequently, the particulate additive solution was added to the additive amount shown in Table 1, and the mixture was heated at the dissolution temperature shown in Table 1 for 3 hours and completely dissolved with stirring. Thereafter, the mixture was filtered using Azumushi No.244 (manufactured by Azumi Co., Ltd.) to prepare Dope A. The composition of Dope A is shown below.

Cycloolefin resin P 100.0 mass%

Dichloromethane 290.0 mass%

Fine particle addition liquid 27.3 mass%

Hindered phenol compound (coagulation inhibitor A) 0.1 mass%

Using the band softening device, the prepared Dope A was plied with a flexible support made of stainless steel (supporting temperature: 22 캜). The amount of the residual solvent in Dope A was peeled off in a state of approximately 20 mass%, and both ends in the width direction of the film were held by a tenter to obtain a film having a residual solvent amount of 10 mass% %). Thereafter, the rolls of the heat treatment apparatus at 90 占 폚 were transported for 30 minutes, and further dried to produce an optical film 101. [ The thickness was 15 μm and the width was 1492 mm.

As the hindered phenol compound (coagulation inhibitor A), IRGANOX1076 (manufactured by BASF Japan Ltd.) was used.

&Lt; Fabrication of optical film 102 >

(Preparation of fine particle dispersion)

11 mass% of silica fine particles (Aerosil R812: trimethylsilane treated product, manufactured by Nippon Aerosil Co., Ltd.)

Ethanol 89 mass%

The resulting mixture was stirred with a dissolver for 50 minutes, and then dispersed using a 10,000 ton dispersing machine to prepare a fine particle dispersion.

(Preparation of fine particle addition liquid 1)

Dichloromethane was added to the dissolution tank, and the prepared fine particle dispersion was slowly added thereto while sufficiently stirring the dichloromethane. Further, the particles were dispersed in the attritor so that the particle diameter of the secondary particles became a predetermined value. This was filtered with Finetmet NF (manufactured by Nippon Seisen Co., Ltd.) to prepare a fine particle addition liquid 1.

(Preparation of Dope B)

The synthesized cycloolefin resin P was added to a pressurized dissolution tank containing ethanol while stirring. Subsequently, the particulate additive solution was added to the additive amount shown in Table 1, and the mixture was heated at the dissolution temperature shown in Table 1 for 3 hours and completely dissolved with stirring. Thereafter, the mixture was filtered using Azumirosi No.244 (manufactured by Azumi Co., Ltd.) to prepare Dope B. The composition of dope B is shown below.

Cycloolefin resin P 100.0 mass%

Dichloromethane 290.0 mass%

Ethanol 10.0 mass%

Distilled water 1.0 mass%

Fine particle addition liquid 27.3 mass%

Using the band softening device, the prepared Dope B was plied to a flexible support made of stainless steel (supporting temperature: 22 캜). The amount of the residual solvent in the dope B was peeled off in a state of about 20 mass% and both ends in the width direction of the film were held with a tenter to obtain a film having a residual solvent amount of 1.01 times (1 %). Thereafter, the space between the rolls of the heat treatment apparatus at 90 占 폚 was transported for 30 minutes, and further dried to produce the optical film 101. The thickness was 15 μm and the width was 1492 mm.

&Lt; Fabrication of optical film 103 >

In the production of the optical film 102, an optical film 103 was produced in the same manner as the optical film 103 except that the following Doping C was used.

(Preparation of Dope C)

The synthesized cycloolefin resin P was introduced into a pressurized dissolution tank containing ethanol while stirring and then heated at the dissolution temperature shown in Table 1 for 3 hours and completely dissolved with stirring. Thereafter, the mixture was filtered using Azumushi No.244 (manufactured by Azumi Co., Ltd.) to prepare Dope C. The composition of dope C is shown below.

Cycloolefin resin P 100.0 mass%

Dichloromethane 290.0 mass%

Ethanol 10.0 mass%

Distilled water 1.0 mass%

Hindered phenol compound (coagulation inhibitor A) 0.3 mass%

<Fabrication of Optical Film 104>

An optical film 104 was produced in the same manner as the optical film 102 except that the following Doping D was used.

(Doped D)

Cycloolefin resin P 100.0 mass%

Dichloromethane 290.0 mass%

Ethanol 10.0 mass%

Distilled water 1.0 mass%

Fine particle addition liquid 0.91 mass%

Hindered phenol compound (coagulation inhibitor A) 0.3 mass%

<Fabrication of Optical Films 105 to 108>

Optical films 105 to 108 were produced in the same manner as in the production of optical film 104 except that the amount of silica particles added was changed as shown in Table 1. [

&Lt; Fabrication of optical films 109 to 113 >

Optical films 109 to 113 were produced in the same manner as in the production of optical film 104 except that the kinds of silica particles were changed as shown in Table 1. [

In the table, R805, R976S, RY300, 200V and R812S are products of Aerosil series manufactured by Nippon Aerosil Co., Ltd.

R805: Octylsilane treated product

R976S: Products treated with dimethylsilane

RY300: Products treated with dimethylpolysiloxane

200V: untreated product

R812S: Trimethylsilane-treated product

<Fabrication of Optical Films 114 to 118>

Optical films 114 to 118 were produced in the same manner as in the production of optical film 104 except that the amount of hindered phenol compound (coagulation inhibitor A) added was changed as shown in Table 1. [

As the optical film 118, a hindered phenol compound (coagulation inhibitor B) IRGANOX1010 (BASF Japan Co., Ltd.) was used in place of the hindered phenol compound (cohesion preventing agent A).

<Fabrication of Optical Films 119 to 122>

Optical films 119 to 122 were produced in the same manner as in the production of optical film 104 except that the amount of ethanol was changed so that the amount of ethanol in the film was changed to the amount shown in Table 2, and the drying temperature and drying time were changed.

Specifically, they were produced under the following conditions.

The optical film 119 transported 5 parts by mass of ethanol in the dope composition and the temperature of the drying heat treatment apparatus after stretching at 110 DEG C for 50 minutes.

The optical film 120 transported 5 parts by mass of ethanol in the dope composition and the temperature of the drying heat treatment apparatus after stretching at 90 DEG C for 30 minutes.

The optical film 121 transported 20 parts by mass of ethanol in the dope composition and the temperature of the drying heat treatment apparatus after stretching at 90 DEG C for 30 minutes.

The optical film 122 transported 22 parts by mass of ethanol in the dope composition and the temperature of the drying heat treatment apparatus after stretching at 90 DEG C for 30 minutes.

<Fabrication of Optical Films 123 and 124>

In the production of the optical film 106, optical films 123 and 124 were produced in the same manner except that the dissolution temperature of the dope was changed to 55 占 폚 and 10 占 폚, respectively.

<Fabrication of optical film 125>

(Preparation of Cycloolefin Resin Q Synthesis Liquid)

10-undecenoic acid, a phenol-based stabilizer, a phosphorus-based stabilizer, and a hindered amine-based light stabilizer are added to the mixture of the following norbornene monomers, followed by dissolution or dispersion, and further adding triphenylphosphine, ruthenium The catalyst was added and mixed with a line mixer to prepare a cycloolefin-based resin Q-synthesized liquid having no hydrogen-bond-soluble group. The composition of the cycloolefin resin Q synthesis solution is shown below.

(Composition of Cycloolefin Resin Q Synthesis Liquid)

Norbornene-based monomer mixture solution (dicyclopentadiene 90 parts, tricyclopentadiene 10 parts) 100.0 mass%

1.6 mass% of silica fine particles (Aerosil R812 manufactured by Nippon Aerosil Co., Ltd.)

10-undecanoic acid 0.3 mass%

Hindered phenol compound (coagulation inhibitor A) 0.1 mass%

1.0% by mass of a phosphorus stabilizer

Triphenylphosphine 1.0 mass%

Ruthenium catalyst 1.6 mass%

The cycloolefin resin Q synthesized liquid prepared above was applied to a carrier film made of polyethylene terephthalate having a thickness of 0.075 mm at 25 占 폚 to form a cast film and subsequently the same carrier film prepared separately from above the coating layer was prepared Lt; / RTI &gt; Thereafter, the film was heated at 200 占 폚 for 3 minutes and then cooled to 20 占 폚. The upper and lower carrier films were respectively peeled off to obtain an optical film 125 (thickness: 15 mu m, width: 1492 mm).

<Fabrication of Optical Film 126>

The optical film 106 was produced in the same manner as the optical film 106 except that the following Dope E was used.

(Dope E)

Cycloolefin resin P 100.0 mass%

Dichloromethane 290.0 mass%

Ethanol 10.0 mass%

Fine particle addition liquid 27.3 mass%

Hindered phenol compound (coagulation inhibitor A) 0.3 mass%

<Fabrication of Optical Film 127>

An optical film 127 was produced in the same manner as in the production of the optical film 106 except that the following Dope F was used.

(Dope F)

Cycloolefin resin P 100.0 mass%

Dichloromethane 290.0 mass%

Methanol 8.0 mass%

Distilled water 1.0 mass%

Fine particle addition liquid 27.3 mass%

Hindered phenol compound (coagulation inhibitor A) 0.3 mass%

<Fabrication of optical film 128>

An optical film 128 was produced in the same manner as in the production of the optical film 106 except that the following Dope G was used. As the cycloolefin resin R used here, Aton G7810 manufactured by JSR Corporation containing 0.25% by mass with respect to 100 parts by mass of a hindered phenol-based compound (coagulation inhibitor A) was used.

(Dope G)

Cycloolefin resin R (JSR ARTON G7810) 100.0 mass%

Dichloromethane 290.0 mass%

Ethanol 10.0 mass%

Distilled water 1.0 mass%

Fine particle addition liquid 27.3 mass%

&Lt; Fabrication of optical films 129 and 130 >

In the production of the optical film 106, the dope was applied to a carrier film made of polyethylene terephthalate having a thickness of 0.075 mm at 25 캜 to form a cast film, and then the same carrier film prepared separately from above the coating layer was laminated Respectively. Thereafter, the film was heated at 200 占 폚 for 3 minutes and then cooled to 20 占 폚. The upper and lower carrier films were peeled off to obtain an optical film 129 (thickness: 3 占 퐉, width: 1492 mm) Thickness: 5 mu m, width: 1492 mm).

«Evaluation»

The following evaluations were carried out using the optical films 101 to 130 produced above.

[1] Measurement of hydrophobicity of silica particles

The degree of hydrophobicity of the silica particles was expressed by a methanol wettability value (hereinafter, referred to as MW value) obtained by the present method using the methanol wetting method (hereinafter referred to as MW method).

In the MW method, in order to quantify the degree of hydrophobicity of the fine particles, the first solution and the second solution in which methanol and pure water were mixed were used, respectively. At this time, the mixing ratio of methanol to pure water is 3: 7 in the first solution, and is 6: 4 in the second solution. Then, the same amount of the above-mentioned fine particles is added to each solution, followed by stirring and mixing. Each of the mixed solutions is centrifuged to determine the volume of the sediment of the fine particles, and the volume of the sediment of the fine particles in the first solution is defined as tmL And the volume of sediment of the fine particles in the second solution is denoted by smL, the MW value in the first solution = (t / A) 100 (%) and the MW value in the second solution MW value = (s / A) x 100 [%]. Here, A is the volume (AmL) of silica particles added at the beginning.

[MW method]

(1) A first solution A is prepared by mixing methanol solution C and pure water D at a volume ratio of 3: 7 (for example, 60 mL of pure water D with respect to 40 mL of methanol solution C)

(2) Then, 0.2 g of the silica particle powder E and 7 ml of the first solution A are put into a 10-ml sedimentation pipe F. Then,

(3) The capillary tube F is covered, and the fine particle powder E is shaken and mixed in the first solution A using a Turbula mixer. At this time, the condition of the turbula mixer is 90 rpm for 30 seconds.

(4) Use a centrifuge to sediment the silica particle powder E. The condition of the centrifugal separator is 3500 rpm for 10 minutes.

(5) The sedimentation amount of the sedimented particulate powder E that can be read by the scale of the sedimentation pipe is read as volume, and the value is referred to as tmL.

(6) A second solution B is prepared by mixing the methanol solution C and the pure water D in a volume ratio of 6: 4 (for example, 40 mL of pure D for 60 mL of the methanol solution C).

(7) A precipitate of the silica particle powder E was prepared by the procedures (8) to (11) as described in (2) to (5) above using the second solution B, The sedimented amount of the precipitated silica particle powder E is read as a volume, and the value is referred to as smL.

(12) The MW value (%) is obtained by the following formula.

MW value in the first solution = (t / A) x 100 [%]

MW value in the second solution = (s / A) x 100 [%]

Here, A is the volume (AmL) of silica particles added at the beginning.

[2] Average particle diameter of silica particles

The average particle diameter of the silica particles was measured by the following method.

The particle diameter of the silica particles in the optical film was measured by taking a cross-section of the film cut with a microtome at a suitable magnification with a scanning electron microscope (SEM) and measuring the particle diameter of 100 particles The particle diameter is measured, and an average value is obtained to obtain an average particle diameter. The particle diameter was defined as the diameter when the cross section of the particles was a circular shape and the area when the particle shape other than the circular shape was calculated and converted to a circular shape.

SEM: JSM-6060LA (JEOL: Nihon Denshikushi Co., Ltd.)

Microtome: Leica EM UC6

[3] The amount of ethanol, methanol and distilled water in the film

The amount of ethanol and the amount of methanol in the film were measured by the following methods.

The remaining amount of the alcohol and distilled water used as the solvent component was measured by the following method.

The optical film cut into a predetermined shape was placed in a 20 mL sealed glass container and treated at 120 DEG C for 20 minutes and then subjected to gas chromatography (apparatus: HP 5890 SERIES II, column: DB-WAX (inner diameter 0.32 mm, length 30 m) , Detection: FID), and the temperature was raised to 100 DEG C at 80 DEG C / min after holding the GC temperature elevation condition at 40 DEG C for 5 minutes.

[4] wrinkles, vertical

A specimen of 90 cm in width and 100 cm in length was cut out from the optical film and placed on a table. Five FLR40S-EX-D / M "fluorescent lamps (FLR40S-EX-D / M manufactured by Panasonic) were arranged and fixed at a height of 1.5 m from the object so that light was irradiated from the angle of 45 ° to the object sample. The fluorescent lamp was turned on to illuminate the sample, and the surface of the sample was visually observed and evaluated according to the following criteria.

○: All five fluorescent lamps are visible.

△: Fluorescent light is bent a little, and there is a part that is visible.

X: Fluorescent light is seen as a whole bent

[5] polarizing plate punching crack

A polarizing plate was produced using the optical films 101 to 130 prepared above.

The roll type polyvinyl alcohol film having a thickness of 30 占 퐉 was successively stretched 5 times in the aqueous iodine solution and dried to obtain a polarizer having a thickness of 7 占 퐉.

Then, the prepared polarizer was sandwiched between the above-prepared optical films 101 to 130 from both sides, and adhered via the following ultraviolet curable adhesive liquid to prepare a polarizing plate.

At that time, the absorption axis of the polarizer and the slow axis of the optical film of the present invention were bonded so as to be perpendicular to each other.

[Preparation of ultraviolet curable adhesive liquid 1]

The following components were mixed and defoamed to prepare an ultraviolet curable adhesive liquid 1. Further, triarylsulfonium hexafluorophosphate was compounded in a 50% propylene carbonate solution, and the solid content of triarylsulfonium hexafluorophosphate was shown below.

3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate

                                                    45 parts by mass

Polyd GT-301 (alicyclic epoxy resin manufactured by Daicel Chemical Industries, Ltd.)

                                                    40 parts by mass

15 parts by mass of 1,4-butanediol diglycidyl ether

Triarylsulfonium hexafluorophosphate 2.3 parts by mass

9,10-dibutoxyanthracene 0.1 part by weight

2.0 parts by mass of 1,4-diethoxynaphthalene

The polarizing plate was produced by subjecting the surface of the film to a corona discharge treatment at a corona output power of 2.0 kW and a line speed of 18 m / min, applying the prepared ultraviolet curing type adhesive liquid 1 to a corona discharge treated surface, 3 탆 by a bar coater to form an ultraviolet curable adhesive layer.

The polarizing plate was irradiated with ultraviolet rays from the side of one optical film using an ultraviolet irradiation device equipped with a belt conveyor (lamp: D bulb manufactured by Fusion UV Systems Co., Ltd.) so that the accumulated light quantity became 750 mJ / The ultraviolet curable adhesive layer was cured.

The obtained polarizing plate was punched into a rectangular shape with a size of 20 cm in the absorption axis direction of the polarizer and 10 cm in the direction perpendicular to the absorption axis, and the glass plate was joined to the glass plate through the adhesive layer to obtain a sample. The sample was allowed to stand in an atmosphere of -40 ° C for 30 minutes, then left in an atmosphere of 90 ° C for 30 minutes, and this operation was made into one cycle. The cycle was repeated on the basis of the following criteria, and then the polarizing plate was observed. When a crack occurred, its length was measured. At the same time, the degree of polarization of the polarizing plate was also measured, and evaluation was performed based on the following criteria.

<Crack evaluation>

&Amp; cir &amp;: no cracks occur even after 500 cycles or less than 1 cm

DELTA: No crack occurred up to 250 to 500 cycles or less than 1 cm

C: no cracks occurred up to 250 cycles, or less than 1 cm

[6] punching cutting powder evaluation

The occurrence of cutting powder when the polarizing plate was cut was observed with an optical microscope to see whether or not cut cutting powder of 5 占 퐉 or more of a portion of 1 cm from the cut portion occurred.

○: No cutting powder occurred

×: Cutting powder occurred

[7] Transparency (Hayes)

The haze (%) of the optical film was measured in accordance with JIS K-7136 using a commercially available haze meter (manufactured by Nippon Denshoku Co., Ltd., product name "NDH 2000" If the haze is less than 0.5%, the transparent optical film can be used for various devices.

○: less than 0.5%

×: 0.5% or more

[8] Phase difference

The in-plane retardation value Ro and the retardation value Rt in the thickness direction were measured at a wavelength of 590 nm under an environment of 23 占 폚 and 55% RH using an automatic birefringence index liquid scan (Axo Scan Mueller Matrix Polarimeter, , The three-dimensional refractive index is measured, and the refractive indices n _x , n _y , and n _z are calculated using the following equations.

Formula (i): Ro = (n x -n y) × d (㎚)

Formula (ii): Rt = {( n x + n y) / 2-n z} × d (㎚)

[In the formulas (i) and (ii), n _x represents the refractive index in the direction x at which the refractive index becomes maximum in the in-plane direction of the film. n _y represents the refractive index in the direction y perpendicular to the direction x in the in-plane direction of the film. n _z represents the refractive index in the thickness direction z of the film. d represents the thickness (nm) of the film]

[9] Visibility: Evaluation of characteristics as a liquid crystal display

Quot; XPERIA Z4 Tablet &quot; manufactured by Sony Mobile Communications, Inc., which is an IPS type tablet type liquid crystal display device, was peeled off and the liquid crystal cell was sandwiched therebetween. The polarizing plate of the polarizing plate A simple IPS type color liquid crystal display was produced by attaching a black tape from the display side so that light was not leaked at portions not sandwiched between the polarizing plates so as to evaluate the characteristics of the optical film as a polarizing plate As a result, the liquid crystal display device using the polarizing plate of the present invention exhibited excellent contrast performance without any unevenness of color, and excellent display performance even when compared with the liquid crystal TV before the polarizing plate was peeled off.

○: No problem in both contrast and color unevenness

X: Clear deterioration of both contrast and color unevenness was observed

[10] Coloration

The obtained sheet was placed on a white paper, and then the sheet was placed, and the degree of coloring was visually evaluated.

○: No coloring observed

Δ: Slight yellowish coloration

× yellow stain clearly visible

[11] Light spot

The spots on the film were measured by the following measuring method.

Two polarizing plates are arranged in an orthogonal state (Cross Nicol) to block the transmitted light, and a sample produced between two polarizing plates is placed. As the polarizing plate, a glass protective plate was used. Light was irradiated from one side and the number of luminescent spots with a diameter of 0.01 mm or more per 100 cm 2 was counted from the opposite side with an optical microscope (50 times). The smaller the number of spots, the better the characteristics.

?: 0 to 2

?: 3 to 12

X: 13 or more

○, △ can be provided for practical use.

The composition of the optical film and the above evaluation results are summarized in Tables 1 and 2.

From Table 1 and Table 2, it can be seen that the optical film of the present invention contains a cycloolefin resin having a hydrogen-bond-soluble group, an alcohol solvent, a hindered phenol compound, water and silica particles having a specific degree of hydrophobicity, It was possible to obtain an optical film using a cycloolefin-based resin which is remarkably reduced in occurrence of punching cutting powder as well as excellent in overall appearance, transparency, phase difference, IPS mode liquid crystal display device visibility, coloring and foreign matter Able to know.

INDUSTRIAL APPLICABILITY The optical film of the present invention is suitably used for a polarizing plate or a liquid crystal display device because it can reduce the occurrence of cracks and cutting powder during punching of a polarizing plate when the optical film is used for a protective film of a polarizing plate.

1: melting pot
3, 6, 12, 15: filter
4, 13: stock kiln
2, 5, 11, 14: Pump pump
8, 16: conduit
10: Additive feeding kiln
20: junction pipe
21: Mixer
30: pressure die
31: metal support
32: Web
33: Peeling position
34: Stretching device
35: Drying apparatus
36: conveying roller
37: retractor
41: Feeding kiln
42: stock kiln
43: pump

Claims (5)

1. An optical film comprising a cycloolefin-based resin,
Wherein the cycloolefin resin is a cycloolefin resin having at least one hydrogen-bond-soluble group,
Wherein the film contains an alcoholic solvent and a hindered phenolic compound,
Wherein the degree of hydrophobicity measured by the methanol wetting method is 20% or less when the first solution having methanol and pure water at a volume ratio of 3: 7 is used and the second solution having methanol and pure water at a volume ratio of 6: 4 Is contained in an amount of from 0.1 to 2.5% by mass based on the total mass of the film, the silica particles having a degree of hydrophobicity of 80% or more. The method according to claim 1,
Wherein the silica particles have a secondary average particle diameter in the range of 100 to 400 nm. 3. The method according to any one of claims 1 to 2,
Wherein the alcoholic solvent is contained in a range of 10 to 1000 ppm and the hindered phenolic compound is contained in an amount of 0.1 to 0.5% by mass. 4. The method according to any one of claims 1 to 3,
And further contains water in a range of 50 to 500 ppm. 5. The method according to any one of claims 1 to 4,
Plane retardation Ro at a measurement wavelength of 590 nm and a phase difference Rt in the thickness direction at the measurement wavelength of 590 nm are Ro? 5 nm and -15 nm? Rt? 15 nm, respectively, &Lt; / RTI &gt;

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