JP5182521B2 - Composition for antireflection layer, antireflection film, polarizing plate, and image display device - Google Patents

Description

  The present invention relates to an antireflection composition, an antireflection film, a polarizing plate, and an image display device.

  In general, an antireflection film is used for an image display device such as a cathode ray tube display device (CRT), a plasma display (PDP), an electroluminescence display (ELD), or a liquid crystal display device (LCD). In order to prevent reflection of light, it has a function of reducing the reflectance by the light interference of the multilayer thin film, and is disposed on the outermost surface of the display.

  As a technique for reducing the reflectance, there is a method of reducing the refractive index of the low refractive index layer on the outermost surface, and a low refractive index material or a method of reducing the refractive index by increasing the number of voids has been proposed. However, in any technique, film strength and scratch resistance are weak points.

  A method is known in which a plurality of hollow silica particles having a porous or hollow interior are used, and a binder for a low refractive index layer is formed by a so-called sol-gel method while maintaining a low refractive index due to voids (Patent Document 1). ).

  This method has a problem that practical film strength cannot be secured with a low refractive index layer containing 20 mass% or more of hollow silica particles in order to lower the refractive index.

  Then, the technique which uses the hardened | cured material by an active energy ray as a binder instead of formation of the binder by a sol gel method is proposed (patent document 2).

  Although this method improves the scratch resistance, the refractive index of the cured product that can be selected as a binder is not so low and the performance as a low refractive index layer is insufficient, and the adhesion to the lower hard coat layer is also low. Was also a problem.

JP 2007-182511 A JP 2008-26493 A

  The present invention is a composition for antireflection for achieving a low refractive index layer having a sufficiently low refractive index but excellent in scratch resistance and adhesion and exhibiting high pencil hardness, and curing the composition. An object of the present invention is to provide an antireflection film, a polarizing plate and an image display device having an additional layer.

The object of the present invention has been achieved by the following.
1. An antireflection layer containing (A) at least two types of silica particles having different average particle diameters, (B) a cationically polymerizable compound represented by the following general formula (1), and (C) a photocationic polymerization initiator a use composition, (a) of the at least two kinds of silica particles having an average particle diameter is different, at least one hollow silica particles, at least one is Ri Ah with colloidal silica particles, the average of the colloidal silica particles the ratio of the the R1 '/ R2', the composition for an antireflection layer, characterized in der Rukoto 0.15 to 0.60 'average particle diameter R2 of the hollow silica particles' diameter R1.

Here, R ¹ represents a group capable of cationic polymerization having 1 to 10 carbon atoms. R ² represents a group selected from a methyl group, an ethyl group, and a propyl group. n represents 0, 1, or 2.
2. 2. The antireflection layer composition as described in 1 above, wherein R ^{1 of the} compound represented by the general formula (1) is a group having an epoxy structure or an oxetane structure.
3. An antireflection film having a layer obtained by curing the composition according to 1 or 2 above.
4). 4. A polarizing plate using the antireflection film as described in 3 above.
5. 5. An image display device using the polarizing plate described in 4 above.

  According to the present invention, an antireflective composition for achieving a low refractive index layer having a sufficiently low refractive index but having excellent scratch resistance and adhesion and exhibiting high pencil hardness is provided. An antireflection film, a polarizing plate, and an image display device having a cured layer can be provided.

Hereinafter, the best mode for carrying out the present invention will be described in detail.
<Antireflection composition>
The antireflective composition of the present invention is a composition capable of producing an antireflective layer, particularly a low refractive index layer, by applying the composition to, for example, a film as a substrate and then curing the composition.

And the basic composition contains (A) at least two types of silica particles having different average particle diameters, (B) a cationically polymerizable compound represented by the following general formula (1), and (C) a photocationic polymerization initiator. It is characterized by doing.
<(A) Silica particles>
The present invention is characterized by containing at least two types of silica particles having different average particle diameters. At least one of them is preferably hollow silica particles. The hollow silica particles are preferably hollow silica particles having an outer shell layer and porous or hollow inside.

  As the silica particles, in addition to hollow silica particles having an outer shell layer and porous or hollow inside, at least one kind is preferably used as colloidal silica or nanoporous silica.

  In the present invention, it is particularly preferable that (A) at least two types of silica particles having different average particle diameters are a combination of hollow silica particles and colloidal silica particles in terms of obtaining high pencil hardness.

(Hollow silica particles)
As a specific example of the hollow silica particles having an outer shell layer and the inside is porous or hollow,
(1) Composite particles comprising porous particles and a coating layer provided on the surface of the porous particles,
(2) Cavity particles having a cavity inside and filled with a solvent, a gas or a porous substance,
It is.

  Note that the cavity particles are particles having a cavity inside, and the cavity is surrounded by a particle wall. The cavity is filled with contents such as a solvent, a gas, or a porous material used at the time of preparation. The average particle size of such hollow silica particles is 5 to 200 nm, preferably 10 to 70 nm. The particle diameter of the hollow silica particles is preferably monodispersed with a coefficient of variation of 1 to 40%.

  In this invention, the average particle diameter of the hollow silica particle used can be measured from the electron micrograph by a scanning electron microscope (SEM) etc. You may measure by the particle size distribution meter etc. which utilize a dynamic light scattering method, a static light scattering method, etc.

  The ratio R1 / R2 between the average particle diameter R1 of the smallest average particle diameter and the average particle diameter R2 of the largest average particle diameter in at least two types of hollow silica particles having different average particle diameters of the present invention. Is preferably set to 0.30 or more and less than 1.00. More preferably, it is 0.45 or more and 0.96 or less.

  The average particle diameter of the hollow silica particles used in the present invention is appropriately selected according to the thickness of the transparent film of the low refractive index layer to be formed, and is preferably less than 100% of the film thickness of the low refractive index layer. .

  These hollow silica particles are preferably used in a state of being dispersed in a suitable medium in order to form a low refractive index layer.

  As the dispersion medium, water, alcohol (for example, methanol, ethanol, isopropyl alcohol), ketone (for example, methyl ethyl ketone, methyl isobutyl ketone), ketone alcohol (for example, diacetone alcohol), propylene monomethyl ether, propylene glycol monomethyl ether acetate and the like are preferable. .

  The thickness of the coating layer of the composite particles or the thickness of the particle walls of the hollow particles is 1 to 40 nm, preferably 1 to 20 nm, more preferably 2 to 15 nm. In the case of composite particles, if the thickness of the coating layer is less than 1 nm, the particles may not be completely covered, and the coating liquid component can easily enter the composite particles to reduce the internal porosity. However, the effect of lowering the refractive index may not be obtained sufficiently.

  In addition, when the thickness of the coating layer exceeds 20 nm, the coating liquid component does not enter the inside, but the porosity (pore volume) of the composite particles is lowered and the effect of lowering the refractive index cannot be sufficiently obtained. Sometimes. In the case of hollow particles, when the particle wall thickness is less than 1 nm, the particle shape may not be maintained, and even when the thickness exceeds 20 nm, the effect of lowering the refractive index may not be sufficiently exhibited. is there.

The coating layer of the composite particles or the particle wall of the hollow particles is preferably composed mainly of silica. Moreover, components other than silica may be contained, specifically, Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , P ₂ O ₃ , Sb ₂ O ₃ , _{sb 2 O 5, SbO 2,} MoO 3, ZnO 2, WO 3 and the like.

Examples of the porous particles constituting the composite particles include those made of silica, those made of silica and an inorganic compound other than silica, and those made of CaF ₂ , NaF, NaAlF ₆ , MgF, and the like. Among these, porous particles made of a composite oxide of silica and an inorganic compound other than silica are particularly preferable.

As inorganic compounds other than silica, Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , P ₂ O ₃ , Sb ₂ O ₃ , Sb ₂ O ₅ , SbO ₂ , MoO ₃ , ZnO ₂ , or WO ₃ and two or more. In such porous particles, the molar ratio: MO _X / SiO ₂ is 0.0001 to 1.0 when silica is represented by SiO ₂ and inorganic compounds other than silica are represented by oxide conversion (MO _X ). Preferably, it is desirable to be in the range of 0.001 to 0.3.

Porous particles having a molar ratio of MO _X / SiO ₂ of less than 0.0001 are difficult to obtain, and even if obtained, the pore volume is small and particles having a low refractive index cannot be obtained. Further, when the molar ratio of the porous particles: MO _X / SiO ₂ exceeds 1.0, the ratio of silica decreases, so that the pore volume increases and it may be difficult to obtain a low refractive index. .

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

  In addition, the pore volume of such porous particles can be determined by a mercury intrusion method. Examples of the contents of the hollow particles include a solvent, a gas, and a porous substance used at the time of preparing the particles. The solvent may contain an unreacted particle precursor used when preparing the hollow particles, the catalyst used, and the like.

  Moreover, what consists of the compound illustrated by the porous particle as a porous substance is mentioned. These contents may be composed of a single component or may be a mixture of a plurality of components.

(Method for producing hollow silica particles)
As a method for producing such hollow silica particles, for example, the method for preparing composite oxide colloidal particles disclosed in paragraphs [0010] to [0033] of JP-A-7-133105 is suitably employed. Specifically, when the composite particles are composed of silica and an inorganic compound other than silica, hollow silica particles can be produced by carrying out the following first to third steps.

(First step: Preparation of porous particle precursor)
In the first step, an alkali aqueous solution of a silica raw material and an inorganic compound raw material other than silica is separately prepared in advance, or a mixed aqueous solution of a silica raw material and an inorganic compound raw material other than silica is prepared in advance. According to the composite ratio of the target composite oxide, a porous particle precursor is prepared by gradually adding it to an alkaline aqueous solution having a pH of 10 or more while stirring.

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

  In addition, alkali-soluble inorganic compounds are used as raw materials for inorganic compounds other than silica. Specifically, an oxo acid of an element selected from Al, B, Ti, Zr, Sn, Ce, P, Sb, Mo, Zn, W, etc., an alkali metal salt or alkaline earth metal salt of the oxo acid, ammonium And salts and quaternary ammonium salts. More specifically, sodium aluminate, sodium tetraborate, zirconyl ammonium carbonate, potassium antimonate, potassium stannate, sodium aluminosilicate, sodium molybdate, cerium ammonium nitrate, and sodium phosphate are suitable.

  Although the pH value of the mixed aqueous solution changes simultaneously with the addition of these aqueous solutions, an operation for controlling the pH value within a predetermined range is not particularly required. The aqueous solution finally has a pH value determined by the type of inorganic oxide and the mixing ratio thereof. There is no restriction | limiting in particular in the addition rate of the aqueous solution at this time. Further, in the production of composite oxide particles, a dispersion of seed particles can be used as a starting material.

The seed particles are not particularly limited, but inorganic oxides such as SiO ₂ , Al ₂ O ₃ , TiO ₂ , or ZrO ₂ or fine particles of these composite oxides are used, and usually these sols are used. be able to. Furthermore, the porous particle precursor dispersion obtained by the above production method may be used as a seed particle dispersion.

  When the seed particle dispersion is used, the pH of the seed particle dispersion is adjusted to 10 or more, and then an aqueous solution of the above compound is added to the alkaline aqueous solution while stirring. Also in this case, it is not always necessary to control the pH of the dispersion. When seed particles are used in this way, it is easy to control the particle size of the porous particles to be prepared, and particles with uniform particle sizes can be obtained.

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

The composite ratio of silica and an inorganic compound other than silica in the first step is that the inorganic compound relative to silica is converted to an oxide (MO _X ), and the molar ratio of MO _X / SiO ₂ is 0.05 to 2.0, Preferably it is in the range of 0.2-2.0. Within this range, the pore volume of the porous particles increases as the proportion of silica decreases. However, even when the molar ratio exceeds 2.0, the pore volume of the porous particles hardly increases. On the other hand, when the molar ratio is less than 0.05, the pore volume becomes small.

When preparing the hollow particles, the molar ratio of MO _X / SiO ₂ is preferably in the range of 0.25 to 2.0.

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

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

  In addition, prior to removing inorganic compounds other than silica from the porous particle precursor, fluorine-substituted, obtained by dealkalizing an alkali metal salt of silica into the porous particle precursor dispersion obtained in the first step. It is preferable to add a silicic acid solution containing an alkyl group-containing silane compound or a hydrolyzable organosilicon compound to form a silica protective film. The thickness of the silica protective film may be 0.5 to 40 nm, preferably 0.5 to 15 nm. Even if a silica protective film is formed, the protective film in this step is porous and thin, so that it is possible to remove inorganic compounds other than silica from the porous particle precursor. is there.

  By forming such a silica protective film, inorganic compounds other than silica described above can be removed from the porous particle precursor while maintaining the particle shape. Further, when forming the silica coating layer described later, the pores of the porous particles are not blocked by the coating layer, and therefore the silica coating layer described later is formed without reducing the pore volume. be able to.

  Note that when the amount of the inorganic compound to be removed is small, the particles are not broken, and thus it is not always necessary to form a protective film.

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

  The amount of the silica source added for forming the silica protective film is preferably small as long as the particle shape can be maintained. If the amount of the silica source is too large, the silica protective film becomes too thick, and it may be difficult to remove inorganic compounds other than silica from the porous particle precursor.

  As the hydrolyzable organosilicon compound used for forming the silica protective film, an alkoxysilane represented by the following general formula (1) can be used. In particular, tetraalkoxysilanes such as fluorine-substituted tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane are preferably used.

R _n Si (OR ′) _4-n (1)
In the formula, R and R ′ represent a hydrocarbon group such as an alkyl group, an aryl group, a vinyl group, and an acrylic group, and n represents 0, 1, 2, or 3.

  As a method of addition, a solution obtained by adding a small amount of alkali or acid as a catalyst to a mixed solution of these alkoxysilane, pure water, and alcohol is added to the dispersion of porous particles, and then alkoxysilane, pure water, and alcohol are added. A solution obtained by adding a small amount of alkali or acid as a catalyst to a mixed solution of the above is added to a dispersion of porous particles, and a silicic acid polymer produced by hydrolyzing alkoxysilane is deposited on the surface of inorganic oxide particles. .

  At this time, alkoxysilane, alcohol, and catalyst may be simultaneously added to the dispersion. As the alkali catalyst, ammonia, an alkali metal hydroxide, or an amine can be used. As the acid catalyst, various inorganic acids and organic acids can be used.

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

(3rd process: Formation of a silica coating layer)
In the third step, a hydrolyzable organosilicon compound or silica containing a fluorine-substituted alkyl group-containing silane compound is added to the porous particle dispersion (in the case of hollow particles, a hollow particle precursor dispersion) prepared in the second step. By adding an acid solution or the like, the surface of the particles is coated with a hydrolyzable organosilicon compound or a polymer such as a silicic acid solution to form a silica coating layer.

  The silicic acid solution is an aqueous solution of a low silicic acid polymer obtained by dealkalizing an aqueous solution of an alkali metal silicate such as water glass by ion exchange treatment.

  The addition amount of the organosilicon compound or silicic acid solution used for forming the coating layer only needs to be sufficient to cover the surface of the colloidal particles, and the finally obtained silica coating layer has a thickness of 1 to 40 nm, It is preferably added in an amount of 1 to 20 nm in the dispersion of porous particles (in the case of hollow particles, hollow particle precursor). When the silica protective film is formed, the organosilicon compound or the silicate solution is added in such an amount that the total thickness of the silica protective film and the silica coating layer is in the range of 1 to 40 nm, preferably 1 to 20 nm. The

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

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

  The refractive index of the hollow silica particles thus obtained is as low as less than 1.42. Such hollow silica particles are presumed to have a low refractive index because the porosity inside the porous particles is maintained or the inside is hollow.

  From the viewpoint of stability when added to the coating composition, the hollow silica particles are preferably hollow silica particles in which a polymer having a hydrocarbon main chain is covalently bonded to the surface.

  Next, hollow silica particles in which a polymer having a hydrocarbon main chain is covalently bonded will be described. The polymer having a hydrocarbon main chain is a direct covalent bond, or a binder is interposed between the silica on the surface of the hollow silica particles and the polymer having the hydrocarbon main chain, and the silica and the binder are covalently bonded. It also refers to a covalent bond between a binder and a polymer. As the binder, a coupling agent is preferably used.

  Hollow silica particles with a covalently bonded polymer having a hydrocarbon main chain can (1) form a covalent bond with the hollow silica particle surface in a state where the hollow silica particle surface is untreated or treated with a coupling agent. A method in which a polymer having a functional group is reacted and the polymer is grafted on the surface of the hollow silica particle, or (2) the surface of the hollow silica particle is untreated or treated with a coupling agent or the like. The polymer can be produced by polymerizing a polymer to grow a polymer chain and surface grafting. As a specific manufacturing method, the method described in JP-A-2006-257308 can be used.

  In the above production method, from the viewpoint of improving the surface modification rate, a method in which a monomer is polymerized from the surface of the hollow silica particles to grow a polymer chain and surface grafting is preferable. More preferred is a method in which hollow silica particles are surface-treated with a coupling agent containing a functional group having a polymerization initiating ability or a chain transfer ability, monomers are polymerized therefrom, polymer chains are grown, and surface grafting is performed. As a surface treatment agent (coupling agent) for introducing a functional group having polymerization initiating ability or chain transfer ability into hollow silica particles, an alkoxy metal compound (for example, titanium coupling agent, alkoxysilane compound (silane coupling agent) )) Is preferably used.

  The hollow silica particles may contain two or more types of hollow silica particles having different average particle diameters.

(Other hollow silica particles)
In the present invention, it is preferable to use hollow silica particles having a conductive metal oxide coating layer for the low refractive index layer because the conductivity can be increased.

  The metal oxide for forming the conductive metal oxide coating layer is not particularly limited. For example, tin oxide, antimony tin oxide, indium tin oxide, antimony oxide, aluminum zinc oxide, gallium zinc oxide, and these The thing chosen from the mixture of these is mentioned. Among these, hollow silica particles coated with antimony oxide are particularly preferable.

  The average thickness of the conductive metal oxide coating layer is in the range of 1 to 40 nm, more preferably 1 to 20 nm, and the hollow silica particles can be sufficiently coated. The thickness of the coating layer is preferably 1 nm or more from the viewpoint of sufficient conductivity.

  The thickness of the coating layer is preferably 40 nm or less in that the effect of improving conductivity is sufficient and the refractive index is sufficient even when the average particle size of the conductive metal oxide-coated hollow silica particles is small.

  In the present invention, hollow silica particles having a particularly preferable antimony oxide coating layer will be described.

The antimony oxide may be any of Sb ₂ O ₃ , Sb ₂ O ₅ , SbO _2, etc., and the antimony oxide coating layer may contain tin oxide or the like. The total content of these antimony oxides in the antimony oxide coating layer is preferably 10% or more. The antimony oxide coating layer may be further coated with silica or the like.

  The volume resistance value of the antimony oxide-coated hollow silica particles is preferably 10 to 5000 Ω / cm, and more preferably 10 to 2000 Ω / cm.

  By setting the volume resistance value within this range, the surface resistance of the low refractive index coating film can be lowered while keeping the refractive index of the particles low. The volume resistance value can be controlled by adjusting the particle size of the core particles, the film thickness of the surface-coated metal oxide layer, and the composition.

  The volume resistance value was measured by the following method.

Using a ceramic cell with a cylindrical hollow (cross-sectional area 0.5 cm ² ) inside, place the cell on the gantry electrode, fill it with 0.6 g of sample powder, insert the projections pressurizes the upper and lower electrodes by a hydraulic motor, by the resistance of 100 kg / cm ² pressurized (Omega) and measured sample height (cm), to multiply the height resistance Asked.

  A method for producing antimony oxide-coated hollow silica particles will be described.

  First, a dispersion of porous silica particles or silica particles having cavities therein is prepared by the method described above. The solid content concentration of the dispersion is preferably in the range of 0.1 to 40% by mass, more preferably 0.5 to 20% by mass. When the solid content concentration is less than 0.1% by mass, the production efficiency is low, and when the solid content concentration exceeds 40% by mass, the obtained antimony oxide-coated hollow silica particles may be aggregated, and the transparency of the coating is low. It may decrease or haze may deteriorate.

  Also, an antimonic acid dispersion (aqueous solution) is prepared. The method for preparing antimonic acid is not particularly limited as long as a coating layer of antimony oxide can be formed on the particle surface without filling the pores and cavities of the porous silica particles or the silica particles having cavities inside, The following method is preferable because a uniform and thin antimony oxide coating layer can be formed.

  Specifically, an alkali antimonate aqueous solution is treated with a cation exchange resin to prepare an antimonic acid (gel) dispersion, and then treated with an anion exchange resin. As the alkali antimonate aqueous solution, for example, an alkali antimonate aqueous solution used in a method for producing an antimony oxide sol described in JP-A-2-180717 is suitable.

The alkali antimonate aqueous solution is preferably obtained by reacting antimony trioxide (Sb ₂ O ₃ ), an alkali substance and hydrogen peroxide, and the molar ratio of antimony oxide, alkali substance and hydrogen peroxide is 1: 2.0 to 2.5: 0.8 to 1.5, preferably 1: 2.1 to 2.3: 0.9 to 1.2, and the system containing antimony trioxide and an alkaline substance is peroxidized. It is obtained by adding hydrogen at a rate of 0.2 mol / hr or less per mol of antimony trioxide.

The antimony trioxide used at this time is preferably a powder, particularly a fine powder having an average particle size of 10 μm or less, and examples of the alkaline substance include LiOH, KOH, NaOH, Mg (OH) ₂ , and Ca (OH). _2, etc. Among them, alkali metal hydroxides such as KOH and NaOH are preferable. These alkaline substances have the effect of stabilizing the resulting antimonic acid solution.

First, a predetermined amount of an alkaline substance and antimony trioxide are added to water to prepare an antimony trioxide suspension. The antimony trioxide concentration of the antimony trioxide suspension is desirably in the range of ₃ to 15% by mass as Sb ₂ O ₃ . Next, this suspension was heated to 50 ° C. or higher, preferably 80 ° C. or higher, and hydrogen peroxide having a concentration of 5 to 35% by mass was added to 0.2 mol / hr or less of antimony trioxide. Add at a rate.

  When the hydrogen peroxide solution is added at a rate higher than 0.2 mol / hr, the particle size of the obtained antimony oxide particles is increased, and the particle size distribution is widened, which is not preferable. Moreover, since productivity is bad when the addition rate of hydrogen peroxide water is very slow, a preferable addition rate range is 0.04 to 0.2 mol / hr.

The alkali antimonate aqueous solution (when MHSbO ₃ : M is an alkali metal) obtained by the above reaction is separated from an undissolved residue as necessary, and further diluted as necessary, and treated with a cation exchange resin. Then, an antimonic acid gel (HSbO ₃ ⁻ ) _n dispersion is prepared by removing alkali ions.

  Further, the alkali antimonate aqueous solution may contain an aqueous solution containing a doping agent such as an alkali stannate aqueous solution and a sodium phosphate aqueous solution. When such a doping agent is contained, antimony oxide-coated hollow silica particles having higher conductivity can be obtained.

Here, antimonic acid can be represented by (HSbO ₃ ⁻ ) _n (a polymer having n = 2 or more), and is composed of a polymer of antimonic acid (HSbO ₃ ⁻ ) having a particle diameter of about 1 to 5 nm. Are aggregated to form a gel state.

The concentration of the alkali antimonate aqueous solution when treating with a cation exchange resin is preferably in the range of 0.01 to 5% by mass, more preferably 0.1 to 3% by mass as the solid content Sb ₂ O ₅ . When the solid content is less than 0.01% by mass, the production efficiency is low, and when it exceeds 5% by mass, a large aggregate of antimonic acid may be formed, and it is difficult to coat the hollow silica particles with antimonic acid. May be non-uniform.

  The amount of cation exchange resin used is preferably such that the pH of the resulting antimonic acid dispersion is in the range of 1 to 4, and more preferably in the range of 1.5 to 3.5. When the pH is less than 1, there is a tendency that aggregated particles are generated instead of chain particles, and when the pH exceeds 4, monodispersed particles tend to be generated. In addition, when the pH is less than 1, it is difficult to coat a predetermined amount of antimony oxide because the solubility of antimony oxide is high. When the pH exceeds 4, the obtained antimony oxide-coated hollow silica particles may become an aggregate. The dispersibility in the film may be lowered, and the antistatic effect may be insufficient.

  Next, the antimonic acid dispersion and porous silica particles or a dispersion of silica particles having cavities inside are mixed and aged at a temperature of 50 to 250 ° C., preferably 70 to 120 ° C., usually for 1 to 24 hours. Thus, an antimony oxide-coated hollow silica particle dispersion can be obtained.

The mixing ratio of the antimonic acid dispersion and the silica particle dispersion is 100 parts by mass with silica particles as a solid content, and 1 to 200 parts by mass, preferably ₅ to 100 parts by mass with Sb ₂ O ₅ as antimonic acid. Add to.

  When the mixing ratio of antimonic acid is less than 1 part by mass, the coating is uneven or the thickness of the coating layer becomes insufficient, and the effect of coating with antimony oxide, that is, the effect of imparting and improving conductivity is sufficient. May not be obtained.

  Even when the mixing ratio of antimonic acid exceeds 200 parts by mass, the antimony oxide not contributing to the coating does not increase, and the conductivity of the obtained antimony oxide-coated hollow silica particles is not further improved, and the refractive index is 1.60. May be higher than

  It is preferable that the density | concentration of the mixed dispersion exists in the range of 1-40 mass% as solid content, and also 2-30 mass%. When the concentration of the mixed dispersion is less than 1% by mass, the coating efficiency of antimony oxide is insufficient or the production efficiency is lowered.

  On the other hand, when it exceeds 40 mass%, when the amount of antimonic acid used is large, the resulting antimony oxide-coated hollow silica particles may aggregate.

  The amount of the hollow silica particles added to the low refractive index layer is preferably 10% by mass to 60% by mass, and more preferably 20% by mass to 60% by mass with respect to the entire solid content of the low refractive index layer.

  Since the refractive index of the low refractive index layer can be lowered as the amount of hollow silica particles added increases, the reflectance of the antireflection film can be lowered. However, if it exceeds 60% by mass, the strength of the low refractive index layer is increased. Decreases and the scratch resistance is remarkably deteriorated. When the amount is less than 5% by mass, the effect of lowering the refractive index by adding hollow silica particles is reduced.

(Colloidal silica particles)
The colloidal silica particles preferably used in the present invention are those in which silicon dioxide is colloidally dispersed in water or an organic solvent, and are not particularly limited, but are spherical, acicular or beaded.

  The particle diameter of the colloidal silica particles is preferably monodispersed with a coefficient of variation of 1 to 40%, and the average particle diameter is less than 100% of the film thickness of the low refractive index layer.

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

  Colloidal silica particles are commercially available, and examples thereof include the Snowtex series manufactured by Nissan Chemical Industries, the Cataloid-S series manufactured by Catalytic Chemical Industries, and the Rebacil series manufactured by Bayer.

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

  There are beaded colloidal silica particles such as SNOWTEX-AK series, SNOWTEX-PS series, SNOWTEX-UP series of NISSAN CHEMICAL INDUSTRY CO., LTD. Specifically, IPS-ST-L (isopropanol dispersion, particle size 40-50 nm). , Solid content 30%), MEK-ST-MS (methyl ethyl ketone dispersion, particle diameter 17-23 nm, solid content 35) and the like.

  In the present invention, (A) at least two types of silica particles having different average particle sizes are a combination of at least one kind of hollow silica particles and at least one type of colloidal silica particles, particularly in that high pencil hardness can be obtained. preferable.

At this time, the ratio R1 ′ / R2 ′ between the average particle diameter R1 ′ of the colloidal silica particles and the average particle diameter R2 ′ of the hollow silica particles is preferably set to 0.10 or more and less than 2.50. More preferably, it is 0.10 or more and 1.20 or less, and particularly preferably 0.15 or more and 0.60 or less.
<(B) Cationic polymerizable compound represented by general formula (1)>
The low refractive index layer of the present invention is characterized by containing a cationically polymerizable compound of the general formula (1).

Here, R ¹ represents a group capable of cationic polymerization having 1 to 10 carbon atoms. R ² represents a group selected from a methyl group, an ethyl group, and a propyl group. n represents 0, 1, or 2.

The cationically polymerizable group of R ¹ is preferably a group having a vinyl ether structure, a group having an epoxy structure, or a group having an oxetane structure, and more preferably any one of the following Ra, Rb, and Rc. More preferably, it is any of the following Ra and Rc.

  In order to improve adhesion, it is effective that both an alkoxy group and a group capable of cationic polymerization are bonded to the Si atom as represented by the general formula (1), and n is preferably 0 or 1.

  Preferred specific examples of the cationically polymerizable compound represented by the general formula (1) are shown below.

The compound represented by the general formula (1) is commercially available from Shin-Etsu Chemical Co., Ltd. as KBM-403, KBE-402, KBE-403, for example.
<Cationically polymerizable compounds other than the cationically polymerizable compound of general formula (1)>
In this invention, you may use together cationically polymerizable compounds other than the cationically polymerizable compound of General formula (1). Examples of the cationically polymerizable compound other than the general formula (1) include known compounds such as epoxy compounds, oxetane compounds, phenol compounds, aldehyde compounds, vinyl ether compounds, styrene compounds, cyclic ether compounds, lactone compounds, episulfide compounds, and silicones. It is done.

From the viewpoint of stability of the low refractive index layer composition, the above cationic polymerizable compound is preferably 15% by mass or more and less than 70% by mass in the solid content of the low refractive index layer composition.
<(C) Photocationic polymerization initiator>
Known compounds and photoacid generators can be used as the compound that functions as the photocationic polymerization initiator of the present invention. Examples of the photoacid generator include a cationic polymerization photoinitiator, a dye photodecoloring agent, a photochromic agent, a known compound used in a microresist, and a mixture thereof.

  Specific examples include onium compounds, organic halogen compounds, and disulfone compounds, and onium compounds are preferable.

<Onium compound>
As the onium compound, diazonium salts, sulfonium salts, iodonium salts and the like represented by the following formulas are preferably used, and sulfonium salts are particularly preferable.

ArN ₂ ⁺ Z ⁻ ,
(R) ₃ S ⁺ Z ⁻ ,
(R) ₂ I ⁺ Z ⁻
In the formula, Ar represents an aryl group, R represents an aryl group or an alkyl group having 1 to 20 carbon atoms, and when R appears multiple times in one molecule, they may be the same or different, and Z ⁻ Represents a non-basic and non-nucleophilic anion.

  In each of the above formulas, the aryl group represented by Ar or R is also typically phenyl or naphthyl, and these may be substituted with an appropriate group.

Specific examples of the anion represented by Z ⁻ include tetrafluoroborate ion (BF ₄ ⁻ ), tetrakis (pentafluorophenyl) borate ion (B (C ₆ F ₅ ) ₄ ⁻ ), and hexafluorophosphate ion. (PF ₆ ⁻ ), hexafluoroarsenate ion (AsF ₆ ⁻ ), hexafluoroantimonate ion (SbF ₆ ⁻ ), hexachloroantimonate ion (SbCl ₆ ⁻ ), hydrogen sulfate ion (HSO ₄ ⁻ ), perchloric acid Ion (ClO ₄ ⁻ ) and the like.

  Examples of other onium compounds include ammonium salts, iminium salts, phosphonium salts, arsonium salts, selenonium salts, boron salts, and the like. For example, compounds described in paragraph numbers [0058] to [0059] of JP-A-2002-29162 Etc.

  Of these, diazonium salts, iodonium salts, sulfonium salts, and iminium salts are preferable from the viewpoint of the material stability of the compound.

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

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

  Since many of these compounds are commercially available, such commercially available products can be used. Commercially available initiators include, for example, “Syracure UVI-6990” (trade name) sold by Dow Chemical Japan Co., Ltd., and “Adekaoptomer SP-150” (available from ADEKA Corporation) Product name), Adeka optomer SP-300 (product name), “RHODORSIL PHOTOINITIAOR 2074” (product name) sold by Rhodia Japan Co., Ltd., and the like.

  In the present invention, it is particularly preferable to contain a sulfonium salt in terms of curability, and examples of a preferable sulfonium salt include a sulfonium salt of the general formula (2), (3), (4) or (5). preferable.

[Wherein, R _{1 to} R ₁₇ each represent a hydrogen atom or a substituent, R _{1 to} R ₃ do not simultaneously represent a hydrogen atom, and R _{4 to} R ₇ do not simultaneously represent a hydrogen atom, R _{8 to} R ₁₁ do not represent hydrogen atoms at the same time, and R _{12 to} R ₁₇ do not represent hydrogen atoms at the same time. X- represents a non-nucleophilic anionic residue. ]
Specific examples of the general formulas (2) to (5) are shown below.

In either case, X ⁻ = PF ₆ ⁻ .

  The above compounds can be obtained from THE CHEMICAL SOCIETY OF JAPAN Vol. 71 no. It can be easily synthesized by a known method as in the case of the photoinitiator described in 11, 1998, Organic Electronics Materials Research Group, “Organic Materials for Imaging”, Bunshin Publishing (1993).

(acid)
Known acids that function as a cationic photopolymerization initiator in the present invention include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, or acetic acid, formic acid, methanesulfonic acid, trifluoromethanesulfonic acid, paratoluenesulfonic acid, and the like Examples include Bronsted acids such as organic acids, Lewis acids such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctate, triisopropoxyaluminum, tetrabutoxyzirconium, and tetrabutoxytitanate.

  Aromatic polycarboxylic acids such as pyromellitic acid, pyromellitic anhydride, trimellitic acid, trimellitic anhydride, phthalic acid, phthalic anhydride, or anhydrides thereof, maleic acid, maleic anhydride, succinic acid, succinic anhydride Aliphatic polyvalent carboxylic acid or anhydride thereof such as

  As an acid, only 1 type may be used and 2 or more types may be used together.

These acids and photoacid generators are preferably added in a proportion of 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, with respect to 100 parts by mass of the cationic polymerizable compound. is there. When the addition amount is in the above range, it is preferable from the viewpoint of stability of the curable composition, polymerization reactivity and the like.
<Antireflection layer composition other than (A), (B), (C)>
In addition to (A), (B), and (C), it is preferable to add the following compounds to the composition for an antireflection layer of the present invention.

(catalyst)
In the present invention, the antireflection layer composition preferably contains a catalyst. Examples of the catalyst include inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia, organic bases such as triethylamine and pyridine, metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium, and metal chelate compounds described later. Of these, metal chelate compounds are preferably used.

  As the metal chelate compound, a chelate compound having a metal selected from Zr, Ti, and Al as a central metal can be suitably used without particular limitation.

  Specific examples include tri-n-butoxyethyl acetoacetate zirconium, di-n-butoxybis (ethyl acetoacetate) zirconium, n-butoxy tris (ethyl acetoacetate) zirconium, tetrakis (n-propyl acetoacetate) zirconium, tetrakis ( Zirconium chelate compounds such as acetylacetoacetate) zirconium and tetrakis (ethylacetoacetate) zirconium, diisopropoxybis (ethylacetoacetate) titanium, diisopropoxybis (acetylacetate) titanium, diisopropoxybis (acetylacetone) titanium and the like Titanium chelate compound, diisopropoxyethyl acetoacetate aluminum, diisopropoxyacetylacetonate aluminum , Isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonate) aluminum, monoacetylacetonatobis (ethylacetoacetate) aluminum, etc. Examples of the aluminum chelate compound.

  Of these metal chelate compounds, tri-n-butoxyethyl acetoacetate zirconium, diisopropoxyethyl acetoacetate aluminum, and tris (ethyl acetoacetate) aluminum are particularly preferably used. These metal chelate compounds can be used either alone or in combination.

(binder)
In the present invention, the antireflective composition may contain an organosilicon compound represented by the following general formula (6), a hydrolyzate thereof, or a polycondensate thereof.

General formula (6)
R ⁰ _m SiX _4-m
In the formula, R ⁰ is a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, X is a hydroxyl group or a hydrolyzable substituent, and m is an integer of 0 to 3.

  Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, s-butyl group, hexyl group, decyl group, hexadecyl group and the like. Examples of the aryl group include a phenyl group and a naphthyl group.

  Examples of the hydrolyzable substituent for X include an alkoxy group, a halogen group, and a carboxyl group.

  Specific examples include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane. , Hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, isobutyltrimethoxysilane, trifluoropropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltri Methoxyethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-acryloxypropi Trimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3 -Aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropylmethyldimethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, N-2-aminoethyl-3-aminopropyltriethoxy Silane, 3-triethoxysilyl-N-1,3-dimethylbutylidenepropylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyl Silane, 3-isocyanate propyl triethoxysilane, p- styryl trimethoxysilane, diethyl silane, and the like, used in alone or as a mixture of more than two kinds.

  In addition, an actinic radiation curable resin can be contained as a binder. As the actinic radiation curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and the actinic radiation curable resin layer is formed by curing by irradiating actinic radiation such as ultraviolet rays or electron beams. The Typical examples of the actinic radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, and an ultraviolet curable resin is particularly preferable.

  As the ultraviolet curable resin, for example, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy resin is preferable. Used. Of these, ultraviolet curable acrylate resins are preferred.

  As the ultraviolet curable acrylate resin, a polyfunctional acrylate is preferable. The polyfunctional acrylate is preferably selected from the group consisting of pentaerythritol polyfunctional acrylate, dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate, and dipentaerythritol polyfunctional methacrylate. Here, the polyfunctional acrylate is a compound having two or more acryloyloxy groups and / or methacryloyloxy groups in the molecule.

  Examples of the polyfunctional acrylate monomer include ethylene glycol diacrylate, diethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, and tetramethylolmethane triacrylate. , Tetramethylolmethane tetraacrylate, pentaglycerol triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, glycerol triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol Lithol hexaacrylate, tris (acryloyloxyethyl) isocyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, Tetramethylol methane trimethacrylate, tetramethylol methane tetramethacrylate, pentaglycerol trimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, glycerol trimethacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetramethacrylate Acrylate, dipentaerythritol penta methacrylate, dipentaerythritol hexa methacrylate, isobornyl acrylate and the like preferably. These compounds are used alone or in admixture of two or more. Moreover, oligomers, such as a dimer and a trimer of the said monomer, may be sufficient.

  The ultraviolet curable resin preferably contains a photopolymerization initiator. Specific examples of the amount of photopolymerization initiator include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof, but are not particularly limited thereto. .

(solvent)
The composition for an antireflection layer of the present invention preferably contains an organic solvent.

  Specific examples of organic solvents include alcohols (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), esters (eg, methyl acetate, ethyl acetate). , Propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene chloride, chloroform, carbon tetrachloride), aromatic Group hydrocarbon (eg, benzene, toluene, xylene), amide (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ether (eg, diethyl ether, dioxane, tetrahydrofuran), ether alcohol (eg, 1-methoxy-2-propanol), propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate. Of these, toluene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethanol, isopropanol, and propylene glycol monomethyl ether are particularly preferable.

  The solid content concentration of the composition for an antireflection layer is preferably 1 to 4% by mass. By setting the solid content concentration to 4% by mass or less, coating unevenness is less likely to occur, and 1% by mass or more. As a result, the drying load is reduced.

(Surfactant)
The coating composition for forming the low refractive index layer preferably contains a fluorine-based or silicone-based surfactant. Inclusion of the surfactant is effective for reducing coating unevenness and improving the antifouling property of the film surface.

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

  Commercially available fluorine-based surfactants can also be used, for example, Surflon S-381, S-382, SC-101, SC-102, SC-103, SC-104 (Asahi Glass Co., Ltd.) Fluorard FC-430, FC-431, FC-173 (Fluorochemical-Sumitomo 3M), EFtop EF352, EF301, EF303 (Shin-Akita Kasei Co., Ltd.), Schwegoe Fluer 8035, 8036 (Manufactured by Schwegman), BM1000, BM1100 (manufactured by BM Himmy), MegaFuck F-171, F-470 (all manufactured by DIC Corporation), and the like.

  The fluorine content of the fluorosurfactant is 0.05 to 2% by mass, preferably 0.1 to 1% by mass. One or two or more of the above fluorosurfactants can be used in combination.

  Next, the silicone surfactant will be described.

  Silicone surfactants can be broadly classified into straight silicone oils and modified silicone oils depending on the type of organic group bonded to the silicon atom.

  Here, the straight silicone oil refers to one in which a methyl group, a phenyl group, or a hydrogen atom is bonded as a substituent. A modified silicone oil is one having a component that is secondarily derived from a straight silicone oil. On the other hand, it can be classified from the reactivity of silicone oil. These are summarized as follows.

(Silicone oil)
1. Straight silicone oil 1-1. Non-reactive silicone oil: dimethyl, methylphenyl substitution, etc.

1-2. Reactive silicone oil: methyl hydrogen substitution and the like.
2. Modified silicone oil Modified silicone oil is born by introducing various organic groups into dimethyl silicone oil.

  2-1. Non-reactive modified silicone oil: alkyl, alkyl / aralkyl, alkyl / polyether, polyether, higher fatty acid ester substitution, etc.

  The alkyl / aralkyl-modified silicone oil is a silicone oil in which a part of the methyl group of dimethyl silicone oil is substituted with a long-chain alkyl group or a phenylalkyl group.

  The polyether-modified silicone oil is a surfactant in which hydrophobic dimethyl silicone is introduced into hydrophilic polyoxyalkylene.

  The higher fatty acid-modified silicone oil is a silicone oil in which a part of the methyl group of dimethyl silicone oil is replaced with a higher fatty acid ester.

  The amino-modified silicone oil is a silicone oil having a structure in which a part of the methyl group of the silicone oil is substituted with an aminoalkyl group.

  The epoxy-modified silicone oil is a silicone oil having a structure in which a part of the methyl group of the silicone oil is substituted with an epoxy group-containing alkyl group.

  The carboxyl-modified or alcohol-modified silicone oil is a silicone oil having a structure in which a part of the methyl group of the silicone oil is substituted with a carboxyl group or a hydroxyl group-containing alkyl group.

  Of these, polyether-modified silicone oil is preferably added. The number average molecular weight of the polyether-modified silicone oil is, for example, 1,000 to 100,000, preferably 2000 to 50,000. If the number average molecular weight is less than 1,000, the drying property of the coating film is lowered, and conversely, the number average molecular weight is When it exceeds 100,000, it becomes difficult to bleed out to the coating film surface.

  Specific products include L-45, L-9300, FZ-3704, FZ-3703, FZ-3720, FZ-3786, FZ-3501, FZ-3504, FZ-3508, FZ- from Toray Dow Corning. 3705, FZ-3707, FZ-3710, FZ-3750, FZ-3760, FZ-3785, FZ-3785, Y-7499, Shin-Etsu Chemical KF96L, KF96, KF96H, KF99, KF54, KF965, KF968, KF56, KF995, KF351, KF351A, KF352, KF353, KF354, KF355, KF615, KF618, KF945, KF6004, FL100, BYK series surfactants BYK series, BYK-300 / 302, BYK-306, BYK-307, BY -310, BYK-315, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330, BYK-331, BYK-333, BYK-337, BYK-340, BYK-344, BYK-370 BYK-375, BYK-377, BYK-352, BYK-354, BYK-355 / 356, BYK-358N / 361N, BYK-357, BYK-390, BYK-392, BYK-UV3500, BYK-UV3510, BYK -UV3570, BYK-Silklean 3700, dimethyl silicone series manufactured by GE Toshiba Silicone, XC96-723, YF3800, XF3905, YF3057, YF3807, YF3802, YF3897 and the like.

  The silicone surfactant is a surfactant obtained by substituting a part of the methyl group of the silicone oil with a hydrophilic group. The position of substitution includes a side chain of silicone oil, both ends, one end, both end side chains, and the like. Examples of the hydrophilic group include polyether, polyglycerin, pyrrolidone, betaine, sulfate, phosphate, and quaternary salt.

  As the silicone surfactant, a nonionic surfactant having a hydrophobic group composed of dimethylpolysiloxane and a hydrophilic group composed of polyoxyalkylene is preferable.

  A nonionic surfactant is a generic term for surfactants that do not have a group capable of dissociating into ions in an aqueous solution. In addition to a hydrophobic group, a hydrophilic group includes a hydroxyl group of a polyhydric alcohol, a polyoxyalkylene chain (poly Oxyethylene) or the like as a hydrophilic group. The hydrophilicity becomes stronger as the number of alcoholic hydroxyl groups increases and as the polyoxyalkylene chain (polyoxyethylene chain) becomes longer. When a nonionic surfactant composed of dimethylpolysiloxane with a hydrophobic group and polyoxyalkylene with a hydrophilic group is used, unevenness of the low refractive index layer and antifouling property of the film surface are improved. It is thought that the hydrophobic group made of polymethylsiloxane is oriented on the surface and forms a film surface that is not easily soiled.

  Specific examples of the nonionic surfactant include silicone surfactants SILWET L-77, L-720, L-7001, L-7002, L-7604, Y-7006, FZ-2101 from Toray Dow Corning, FZ-2104, FZ-2105, FZ-2110, FZ-2118, FZ-2120, FZ-2122, FZ-2123, FZ-2130, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ- 2164, FZ-2166, FZ-2191, SUPERSILWET SS-2801, SS-2802, SS-2803, SS-2804, SS-2805, and the like.

  Preferred structures of these nonionic surfactants comprising a hydrophobic group of dimethylpolysiloxane and a hydrophilic group of polyoxyalkylene include linear structures in which dimethylpolysiloxane structural portions and polyoxyalkylene chains are alternately and repeatedly bonded. A block copolymer is preferred. It is preferable from unevenness suppression and leveling properties when a coating composition for forming a low refractive index layer is applied. Specific examples thereof include silicone surfactants ABN SILWET FZ-2203, FZ-2207, FZ-2208, and FZ-2222 manufactured by Toray Dow Corning.

  The coating composition for forming the low refractive index layer has a reactive modified silicone resin (also referred to as a reactive modified silicone oil) described below from the viewpoint of easily exhibiting desirable performance after a durability test under more severe conditions. It is preferable to contain.

  2-2. Reactive modified silicone oil: amino, epoxy, carboxyl, alcohol substitution, etc.

  The reactive modified silicone resin is a reactive type modified silicone resin in which the side chain, one end or both ends of polysiloxane is substituted with amino, epoxy, carboxyl, hydroxyl group, methacryl, mercapto, phenol or the like. Specific examples of the amino-modified silicone resin include KF-860, KF-861, X-22-161A, X-22-161B (manufactured by Shin-Etsu Chemical Co., Ltd.), FM-3311, FM-3325 (and above, Chisso Corporation), epoxy-modified silicone resins such as KF-105, X-22-163A, X-22-163B, KF-101, KF-1001 (above, Shin-Etsu Chemical Co., Ltd.), polyether-modified X-22-4272, X-22-4952 as silicone resins, X-22-3701E, X-22-3710 (above, manufactured by Shin-Etsu Chemical Co., Ltd.) as carboxyl-modified silicone resins, and carbinol-modified silicone resins KF-6001, KF-6003 (Shin-Etsu Chemical Co., Ltd.), methacryl-modified silicone X-22-164C (made by Shin-Etsu Chemical Co., Ltd.) as the resin, KF-2001 (made by Shin-Etsu Chemical Co., Ltd.) as the mercapto-modified silicone resin, and X-22-1821 as the phenol-modified silicone resin (The above is manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of the hydroxyl group-modified silicone resin include FM-4411, FM-4421, FM-DA21, FM-DA26 (manufactured by Chisso Corporation). In addition, X-22-170DX, X-22-2426, X-22-176F (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like are also included.

  The above-mentioned surfactants may be used in combination with other surfactants. For example, anionic surfactants such as sulfonate-based, sulfate-based, phosphate-based, etc. You may use together with nonionic surfactants, such as an ether type | mold and ether ester type | mold etc. which have an oxyethylene chain hydrophilic group. The addition amount of the surfactant described above is 0.05 to 3.0% by mass in the low refractive index layer coating composition, not only to improve the water repellency, oil repellency and antifouling property of the coating film. From the viewpoint of exerting an effect also on the scratch resistance of the surface.

The surfactant described above can also be contained in the antistatic layer for the purpose of reducing coating unevenness.
<Antireflection film>
The antireflection film of the present invention is an antireflection film obtained by laminating a low refractive index layer having a refractive index lower than that of the base film directly or via another layer on the base film. The refractive index layer contains (A) at least two types of silica particles having different average particle diameters, (B) a cationically polymerizable compound of the general formula (1), and (C) a photocationic polymerization initiator. It is a layer produced by hardening | curing the composition for layers.

  By including the cationically polymerizable compound of the general formula (1) in the low refractive index layer, the adhesion is extremely excellent, and the reflection can withstand the light resistance test assuming use under severe conditions for a long period of time. It becomes possible to provide a prevention film.

  Further, (A) among at least two types of silica particles having different average particle diameters, at least one kind is a hollow silica particle, and at least one kind is a colloidal silica particle, while having a sufficiently low refractive index, It is possible to provide an antireflection film that is excellent in scratch resistance and adhesion and that exhibits high pencil hardness.

  In addition, the base film contains a cellulose ester resin, or a cellulose ester resin and an acrylic resin, and further includes a cellulose ester resin, an acrylic resin, and acrylic particles, thereby providing a base material having further excellent adhesion. It becomes possible.

<Layer structure of antireflection film>
The example of the preferable layer structure of the antireflection film of this invention is shown below. Here, “/” indicates that they are stacked. However, the present invention is not limited to the following layer structure.

Film substrate / low refractive index layer Film substrate / hard coat layer / low refractive index layer Back coat layer / film substrate / hard coat layer / low refractive index layer Back coat layer / film substrate / antistatic layer / hard coat Layer / low refractive index layer back coat layer / film substrate / hard coat layer / antistatic layer / low refractive index layer back coat layer / film substrate / antiglare layer / antistatic layer / low refractive index layer <substrate film >
It is preferable that the base film is easy to manufacture, easily adheres to the ionizing radiation curable resin layer, etc., and optically isotropic.

  Any of these may be used, for example, cellulose ester films such as triacetyl cellulose film, cellulose acetate propionate ionate film, cellulose diacetate film, cellulose acetate butyrate film, polyethylene terephthalate, polyethylene naphthalate, etc. Polyester film such as phthalate, polycarbonate film, polyarylate film, polysulfone (including polyethersulfone) film, polyethylene film, polypropylene film, cellophane, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, Shinji Otectic polystyrene film, norbornene resin film, polymethylpentene Examples include, but are not limited to, film, polyether ketone film, polyether ketone imide film, polyamide film, fluororesin film, nylon film, cycloolefin polymer film, polymethyl methacrylate film or acrylic film. Absent.

  Among these, cellulose ester films (for example, Konica Minoltac KC8UX, KC4UX, KC5UX, KC8UCR3, KC8UCR4, KC8UCR5, KC8UY, KC4UE, KC4UE, and KC12UR (above, manufactured by Konica Minolta Opto, Polycarbonate Film) An olefin polymer film and a polyester film are preferable, and in the present invention, a cellulose ester film is particularly preferable in terms of production, cost, isotropy, adhesiveness, and the object effects of the present invention.

  The base film of the present invention has a refractive index of 1.30 to 1.70, preferably 1.40 to 1.65.

  The refractive index can be measured by the method of JISK7142 using an Atpe refractometer 2T.

<Cellulose ester film>
Next, a cellulose ester film (hereinafter, also referred to as a cellulose ester film) that is preferable as a base film will be described.

  The cellulose ester resin (hereinafter also referred to as cellulose ester) is preferably a lower fatty acid ester of cellulose. The lower fatty acid in the lower fatty acid ester of cellulose means a fatty acid having 6 or less carbon atoms. For example, cellulose acetate, cellulose propionate, cellulose butyrate and the like, and JP-A Nos. 10-45804 and 08-231761 , Mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate as described in US Pat. No. 2,319,052 can be used.

  Among the above descriptions, the lower fatty acid esters of cellulose particularly preferably used are cellulose triacetate and cellulose acetate propionate. These cellulose esters can be used alone or in combination.

  In the case of cellulose triacetate, those having an average degree of acetylation (bound acetic acid amount) of 54.0 to 62.5% are preferably used, and more preferably an average degree of acetylation of 58.0 to 62.5%. Cellulose triacetate. When the average degree of acetylation is small, the dimensional change is large, and the polarization degree of the polarizing plate is lowered. When the average degree of acetylation is large, the solubility in a solvent is lowered and the productivity is lowered.

  Preferred cellulose esters other than cellulose triacetate have an acyl group having 2 to 4 carbon atoms as a substituent, and when the substitution degree of acetyl group is X and the substitution degree of propionyl group or butyryl group is Y, the following formula ( It is a cellulose ester containing the cellulose ester which satisfy | fills I) and (II) simultaneously.

Formula (I) 2.6 ≦ X + Y ≦ 3.0
Formula (II) 0 ≦ X ≦ 2.5
Of these, cellulose acetate propionate is preferably used, and it is particularly preferable that 1.9 ≦ X ≦ 2.5 and 0.1 ≦ Y ≦ 0.9. The portion that is not substituted with an acyl group usually exists as a hydroxyl group. These can be synthesized by known methods. The measuring method of the substitution degree of an acyl group can be measured according to ASTM-D817-96.

  The molecular weight of the cellulose ester is preferably a number average molecular weight (Mn) of 60,000 to 300,000, more preferably 70,000 to 200,000, particularly preferably 100,000 to 200,000. The cellulose ester used in the present invention preferably has a weight average molecular weight (Mw) / number average molecular weight (Mn) ratio of 4.0 or less, more preferably 1.4 to 2.3.

  Since the average molecular weight and molecular weight distribution of the cellulose ester can be measured using high performance liquid chromatography, the number average molecular weight (Mn) and the weight average molecular weight (Mw) can be calculated using this, and the ratio can be calculated.

  The measurement conditions are as follows.

Solvent: Methylene chloride Column: Shodex K806, K805, K803G (Used by connecting three Showa Denko Co., Ltd.)
Column temperature: 25 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (GL Science Co., Ltd.)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0 ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corporation)
A calibration curve with 13 samples from Mw = 100000 to 500 was used. The 13 samples are preferably used at approximately equal intervals.

  As the cellulose ester, a cellulose ester synthesized using cotton linter, wood pulp, kenaf or the like as a raw material can be used alone or in combination. In particular, it is preferable to use a cellulose ester synthesized from cotton linter (hereinafter sometimes simply referred to as linter) alone or in combination.

  Moreover, it is preferable that a cellulose-ester film contains an acrylic resin and an acrylic particle from the point by which the objective effect of this invention is exhibited better.

(Acrylic resin, acrylic particles)
Acrylic resin also includes methacrylic resin. Although it does not restrict | limit especially as resin, What consists of 50-99 mass% of methyl methacrylate units and 1-50 mass% of other monomer units copolymerizable with this is preferable.

  Other monomers that can be copolymerized include alkyl methacrylates having 2 to 18 carbon atoms, alkyl acrylates having 1 to 18 carbon atoms, acrylic acid, methacrylic acid, and the like. Saturated acids, maleic acids, fumaric acids, unsaturated divalent carboxylic acids such as itaconic acid, aromatic vinyl compounds such as styrene, α-methylstyrene, and nucleus-substituted styrene, α, β- such as acrylonitrile, methacrylonitrile, etc. Examples thereof include unsaturated nitrile, maleic anhydride, maleimide, N-substituted maleimide, glutaric anhydride, and the like. These can be used alone or in combination of two or more.

  Among these, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, s-butyl acrylate, 2-ethylhexyl acrylate, and the like are preferable from the viewpoint of thermal decomposition resistance and fluidity of the copolymer. n-Butyl acrylate is particularly preferably used.

  The acrylic resin preferably has a weight average molecular weight (Mw) of 80000 to 1000000 from the viewpoint of mechanical strength as a film and fluidity when producing the film. A weight average molecular weight (Mw) can be measured using said high performance liquid chromatography.

  There is no restriction | limiting in particular as a manufacturing method of an acrylic resin (A), You may use any well-known methods, such as suspension polymerization, emulsion polymerization, block polymerization, or solution polymerization. Here, as a polymerization initiator, a normal peroxide type and an azo type can be used, and a redox type can also be used.

  Regarding the polymerization temperature, suspension or emulsion polymerization may be performed at 30 to 100 ° C, and bulk or solution polymerization may be performed at 80 to 160 ° C. Further, in order to control the reduced viscosity of the produced copolymer, polymerization can be carried out using alkyl mercaptan or the like as a chain transfer agent.

  With this molecular weight, both heat resistance and brittleness can be achieved. A commercially available thing can also be used as an acrylic resin. For example, Delpet 60N, 80N (Asahi Kasei Chemicals Co., Ltd.), Dialal BR52, BR80, BR83, BR85, BR88 (Mitsubishi Rayon Co., Ltd.), KT75 (Electric Chemical Co., Ltd.), etc. are mentioned. .

  Next, since the cellulose ester film exhibits the objective effect of the present invention well and is excellent in pencil hardness, it is preferable to contain an acrylic resin and further acrylic particles.

  The acrylic particles will be described. Acrylic particles, for example, a PTFE membrane having a pore diameter less than the average particle diameter of acrylic particles when a predetermined amount of the prepared acrylic resin-containing film is collected, dissolved in a solvent, stirred, and sufficiently dissolved and dispersed. It is preferable that the weight of the insoluble matter filtered and collected using a filter is 90% by mass or more of the acrylic particles added to the acrylic resin-containing film.

  The acrylic particles are not particularly limited, but are preferably acrylic particles having a layer structure of two or more layers, and particularly preferably the following multilayer structure acrylic granular composite.

  The multilayer structure acrylic granular composite is formed by laminating the innermost hard layer polymer, the cross-linked soft layer polymer exhibiting rubber elasticity, and the outermost hard layer polymer from the central portion toward the outer peripheral portion. This refers to a particulate acrylic polymer having a structure.

  Preferred embodiments of the multilayer structure acrylic granular composite used in the acrylic resin composition include the following. (A) Monomer comprising 80 to 98.9% by mass of methyl methacrylate, 1 to 20% by mass of alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, and 0.01 to 0.3% by mass of polyfunctional grafting agent An innermost hard layer polymer obtained by polymerizing the body mixture, (b) in the presence of the innermost hard layer polymer, 75 to 98.5% by mass of an alkyl acrylate having an alkyl group with 4 to 8 carbon atoms, A crosslinked soft layer polymer obtained by polymerizing a monomer mixture composed of 0.01 to 5% by mass of a multifunctional crosslinking agent and 0.5 to 5% by mass of a multifunctional grafting agent, (c) the innermost hard In the presence of a polymer comprising a layer and a crosslinked soft layer, a monomer mixture composed of 80 to 99% by mass of methyl methacrylate and 1 to 20% by mass of alkyl acrylate having 1 to 8 carbon atoms in the alkyl group is polymerized. Outermost hard layer polymer obtained by And the obtained three-layer structure polymer is the innermost hard layer polymer (a) 5 to 40% by mass, the soft layer polymer (b) 30 to 60% by mass, and the outermost layer polymer. A hard layer polymer (c) comprising 20 to 50% by mass, having an insoluble part when fractionated with acetone, and an acrylic granular composite having a methyl ethyl ketone swelling degree of 1.5 to 4.0 in the insoluble part, Can be mentioned.

  As disclosed in Japanese Patent Publication No. 60-17406 or Japanese Patent Publication No. 3-39095, not only the composition and particle size of each layer of the multilayer structure acrylic granular composite are defined, but also the multilayer structure acrylic granular composite. By setting the tensile modulus of the body and the degree of swelling of methyl ethyl ketone in the acetone-insoluble part within a specific range, it is possible to realize a further sufficient balance between impact resistance and stress whitening resistance.

  Here, the innermost hard layer polymer (a) constituting the multi-layer structure acrylic granular composite is 80 to 98.9% by mass of methyl methacrylate and 1 to 20% of alkyl acrylate having 1 to 8 carbon atoms in the alkyl group. % And a polyfunctional grafting agent obtained by polymerizing a monomer mixture consisting of 0.01 to 0.3% by mass.

  Here, examples of the alkyl acrylate having 1 to 8 carbon atoms in the alkyl group include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, s-butyl acrylate, 2-ethylhexyl acrylate, and the like. And n-butyl acrylate are preferably used.

  The proportion of the alkyl acrylate unit in the innermost hard layer polymer (a) is 1 to 20% by mass. When the unit is less than 1% by mass, the thermal decomposability of the polymer is increased, while the unit is 20% by mass. If it exceeds 50%, the glass transition temperature of the innermost hard layer polymer (c) is lowered, and the impact resistance imparting effect of the three-layer structure acrylic granular composite is lowered.

  Examples of the polyfunctional grafting agent include polyfunctional monomers having different polymerizable functional groups, such as allyl esters of acrylic acid, methacrylic acid, maleic acid, and fumaric acid, and allyl methacrylate is preferably used. . The polyfunctional grafting agent is used to chemically bond the innermost hard layer polymer and the soft layer polymer, and the ratio used during the innermost hard layer polymerization is 0.01 to 0.3% by mass. .

  The crosslinked soft layer polymer (b) constituting the acrylic granular composite is an alkyl acrylate 75-98.5 having 1 to 8 carbon atoms in the presence of the innermost hard layer polymer (a). What is obtained by polymerizing a monomer mixture consisting of mass%, polyfunctional crosslinking agent 0.01 to 5 mass% and polyfunctional grafting agent 0.5 to 5 mass% is preferable.

  Here, as the alkyl acrylate having 4 to 8 carbon atoms in the alkyl group, n-butyl acrylate or 2-ethylhexyl acrylate is preferably used.

  In addition to these polymerizable monomers, it is possible to copolymerize 25% by mass or less of other monofunctional monomers capable of copolymerization.

  Examples of other monofunctional monomers that can be copolymerized include styrene and substituted styrene derivatives. As the ratio of the alkyl acrylate having 4 to 8 carbon atoms in the alkyl group and styrene increases, the glass transition temperature of the produced polymer (b) decreases as the former increases, that is, it can be softened.

  On the other hand, from the viewpoint of the transparency of the resin assembly, the refractive index of the soft layer polymer (b) at room temperature is set to the innermost hard layer polymer (a), the outermost hard layer polymer (c), and the hard heat. It is more advantageous to make it closer to the plastic acrylic resin, and the ratio between them is selected in consideration of these.

  For example, in applications where the coating layer thickness is small, it is not always necessary to copolymerize styrene.

  As the polyfunctional grafting agent, those mentioned in the item of the innermost layer hard polymer (a) can be used.

  The polyfunctional grafting agent used here is used to chemically bond the soft layer polymer (b) and the outermost hard layer polymer (c), and the proportion used during the innermost hard layer polymerization is impact resistance. 0.5-5 mass% is preferable from a viewpoint of the property provision effect.

  As the polyfunctional crosslinking agent, generally known crosslinking agents such as divinyl compounds, diallyl compounds, diacrylic compounds, and dimethacrylic compounds can be used, and polyethylene glycol diacrylate (molecular weight 200 to 600) is preferably used.

  The polyfunctional cross-linking agent used here is used to generate a cross-linked structure at the time of polymerization of the soft layer (b) and develop an effect of imparting impact resistance.

  However, if the above-mentioned polyfunctional grafting agent is used during the polymerization of the soft layer, the polyfunctional crosslinking agent is not an essential component because the crosslinked structure of the soft layer (b) is generated to some extent. Is preferably 0.01 to 5% by mass from the viewpoint of imparting impact resistance.

  In the presence of the innermost hard layer polymer (a) and the soft layer polymer (b), the outermost hard layer polymer (c) constituting the multilayer structure acrylic granular composite is 80 to 99 mass% of methyl methacrylate. % And a monomer mixture comprising 1 to 20% by mass of an alkyl acrylate having 1 to 8 carbon atoms in the alkyl group is preferred.

  Here, as the acrylic alkylate, those described above are used, and methyl acrylate and ethyl acrylate are preferably used. The ratio of the alkyl acrylate unit in the outermost hard layer (c) is preferably 1 to 20% by mass.

  Further, for the purpose of improving the compatibility with the acrylic resin during the polymerization of the outermost hard layer (c), an alkyl mercaptan or the like can be used as a chain transfer agent to adjust the molecular weight.

  In particular, it is preferable to provide the outermost hard layer with a gradient such that the molecular weight gradually decreases from the inside toward the outside in order to improve the balance between elongation and impact resistance.

  As a specific method, the monomer mixture for forming the outermost hard layer is divided into two or more, and the molecular weight is increased from the inside by a method of sequentially increasing the amount of chain transfer agent added each time. It is possible to make it smaller toward the outside.

  The molecular weight formed at this time can also be examined by polymerizing the monomer mixture used each time under the same conditions and measuring the molecular weight of the obtained polymer. The particle diameter of the acrylic granular composite that is a multilayer structure polymer is not particularly limited, but is preferably 10 nm or more and 1000 nm or less, and more preferably 20 nm or more and 500 nm or less. In particular, the thickness is most preferably from 50 nm to 400 nm.

  In the acrylic granular composite which is a multilayer structure polymer, the mass ratio of the core and the shell is not particularly limited, but when the total multilayer structure polymer is 100 parts by mass, the core layer is 50 parts by mass. The content is preferably 90 parts by mass or less, and more preferably 60 parts by mass or more and 80 parts by mass or less.

  Examples of such commercially available multilayered acrylic granular composites include, for example, “Metablene” manufactured by Mitsubishi Rayon Co., “Kane Ace” manufactured by Kaneka Chemical Co., Ltd., “Paralloid” manufactured by Kureha Chemical Co., Ltd., Rohm and Haas “Acryloid” manufactured by KK, “Staffyroid” manufactured by Ganz Kasei Kogyo Co., Ltd., “Parapet SA” manufactured by Kuraray Co., Ltd., and the like can be used.

  Specific examples of acrylic particles (c-1) which are graft copolymers suitably used as acrylic particles include unsaturated carboxylic acid ester monomers and unsaturated carboxylic acids in the presence of a rubbery polymer. Examples thereof include a graft copolymer obtained by copolymerizing a monomer mixture comprising a monomer, an aromatic vinyl monomer, and, if necessary, other vinyl monomers copolymerizable therewith.

  There is no particular limitation on the rubbery polymer used for the acrylic particles as the graft copolymer, but diene rubber, acrylic rubber, ethylene rubber, and the like can be used. Specific examples include polybutadiene, styrene-butadiene copolymer, block copolymer of styrene-butadiene, acrylonitrile-butadiene copolymer, butyl acrylate-butadiene copolymer, polyisoprene, butadiene-methyl methacrylate copolymer. , Butyl acrylate-methyl methacrylate copolymer, butadiene-ethyl acrylate copolymer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-isoprene copolymer, and ethylene-acrylic acid Examples thereof include a methyl copolymer. These rubbery polymers can be used alone or in a mixture of two or more.

  Moreover, since the transparency of a base film can be obtained when each refractive index of an acrylic resin and an acrylic particle is approximated, it is preferable. Specifically, the refractive index difference between the acrylic particles and the acrylic resin is preferably 0.05 or less, more preferably 0.02 or less, and particularly preferably 0.01 or less.

  In order to satisfy such a refractive index condition, a method for adjusting the composition ratio of each monomer unit of the acrylic resin, a method for adjusting the composition ratio of the rubbery polymer or monomer used in the acrylic particles, etc. Thus, the difference in refractive index can be reduced, and an acrylic resin-containing film excellent in transparency can be obtained.

  The difference in refractive index referred to here is a solvent-soluble portion obtained by sufficiently dissolving an acrylic resin-containing film under a suitable condition in a solvent in which the acrylic resin is soluble to form a cloudy solution. And the soluble part (acrylic resin) and the insoluble part (acrylic particles) are purified respectively, and the difference in the measured refractive index (23 ° C., measurement wavelength: 550 nm) is shown.

  There is no restriction | limiting in particular in the method of mix | blending an acrylic particle with an acrylic resin, After blending an acrylic resin and another arbitrary component previously, it is a single screw or a twin screw extruder, adding an acrylic particle normally at 200-350 degreeC. A method of uniformly melting and kneading is preferably used.

  A commercially available thing can also be used as an acrylic particle. For example, metabrene W-341 (C2) (manufactured by Mitsubishi Rayon Co., Ltd.), Chemisnow MR-2G (C3), MS-300X (C4) (manufactured by Soken Chemical Co., Ltd.) and the like can be mentioned.

  The acrylic particles preferably contain 0.5 to 45% by mass of acrylic particles with respect to the total mass of the cellulose ester resin and the acrylic resin.

  Moreover, the film which consists of a cellulose-ester resin and an acrylic resin (henceforth a cellulose-ester resin and an acrylic resin film) has a tension softening point of 105-145 degreeC, and a film with which ductile fracture does not occur is preferable. Ductile fracture is caused by the application of a greater stress than the strength of a certain material, and is defined as a fracture that involves significant elongation or drawing of the material before final fracture.

  As a specific measurement method of the tension softening point temperature, for example, using a Tensilon tester (ORIENTEC Co., RTC-1225A), the acrylic resin-containing film is cut out at 120 mm (length) × 10 mm (width), and 10N The temperature can be raised at a rate of 30 ° C./min while pulling with tension, and the temperature at 9 N is measured three times, and the average value can be obtained.

  Moreover, it is preferable that the film consisting of a cellulose ester resin and an acrylic resin has a glass transition temperature (Tg) of 110 ° C. or higher. More preferably, it is 120 ° C. or higher. Especially preferably, it is 150 degreeC or more.

  The glass transition temperature is determined by using a differential scanning calorimeter (DSC-7, manufactured by Perkin Elmer) at a heating rate of 20 ° C./min, and determined in accordance with JIS K7121 (1987). Tmg).

  A film composed of a cellulose ester resin and an acrylic resin preferably has a breaking elongation in at least one direction of 10% or more, more preferably 20% or more, in the measurement based on JIS-K7127-1999.

  The upper limit of the elongation at break is not particularly limited, but is practically about 250%. In order to increase the elongation at break, it is effective to suppress defects in the film caused by foreign matter and foaming. The thickness of the film made of cellulose ester resin and acrylic resin is preferably 20 μm or more.

  More preferably, it is 30 μm or more. The upper limit of the thickness is not particularly limited, but in the case of forming a film by a solution casting method, the upper limit is about 250 μm from the viewpoint of applicability, foaming, solvent drying, and the like. The thickness of the film can be appropriately selected depending on the application.

  The film comprising a cellulose ester resin and an acrylic resin preferably contains an acrylic resin and a cellulose ester resin in a mass ratio of 95: 5 to 30:70 from the viewpoint of both workability and heat resistance. The total substitution degree (T) of the acyl group is 2.00 to 3.00, the acetyl group substitution degree (ac) is 0 to 1.89, the number of carbons of the acyl group other than the acetyl group is 3 to 7, and the weight The average molecular weight (Mw) is preferably 75,000 to 280000. Moreover, the total mass of an acrylic resin and a cellulose-ester resin is 55-100 mass% of an acrylic resin containing film, Preferably it is 60-99 mass%.

  A film made of a cellulose ester resin and an acrylic resin may contain other acrylic resins.

  A cellulose ester film or a film made of a cellulose ester resin and an acrylic resin may be produced by a solution casting method or a melt casting method, but preferably at least stretched in the width direction. In particular, when the amount of residual peeling is 3 to 40% by mass in the solution casting step, it is preferably stretched 1.01 to 1.5 times in the width direction.

  More preferably, it is biaxially stretched in the width direction and the lengthwise direction, and when the amount of residual dissolution is 3 to 40% by mass, it is stretched by 1.01 to 1.5 times in the width direction and the lengthwise direction, respectively. It is desirable that The draw ratio at this time is particularly preferably 1.03 to 1.45.

  The length of the base film is preferably 100 m to 5000 m, and the width is preferably 1.2 m or more, more preferably 1.4 to 4 m. By making the length and width of the base film within the above ranges, the handleability and productivity are excellent.

  The cellulose ester film is preferably a transparent support having a light transmittance of 90% or more, more preferably 93% or more.

(Plasticizer)
The cellulose ester film or cellulose ester resin / acrylic resin film preferably contains the following plasticizer. Examples of plasticizers include phosphate ester plasticizers, phthalate ester plasticizers, trimellitic acid ester plasticizers, pyromellitic acid plasticizers, glycolate plasticizers, citrate ester plasticizers, and polyesters. A plasticizer, a polyhydric alcohol ester plasticizer, and the like can be preferably used.

  For phosphate plasticizers, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenylbiphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc. For phthalate ester plasticizers, diethyl phthalate, dimethoxy Ethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate, diphenyl phthalate, dicyclohexyl phthalate, etc. For pyromellitic acid ester plasticizers such as trimellitate, tetrabutylpyromellitate, In the case of glycolate plasticizers such as lupyromelitate and tetraethylpyromellitate, triacetin, tributyrin, ethylphthalylethyl glycolate, methylphthalylethylglycolate, butylphthalylbutylglycolate, etc. Citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tri-n-butyl citrate, acetyl tri-n- (2-ethylhexyl) citrate and the like can be preferably used.

  Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters.

  As the polyester plasticizer, a copolymer of a dibasic acid and a glycol such as an aliphatic dibasic acid, an alicyclic dibasic acid, or an aromatic dibasic acid can be used. The aliphatic dibasic acid is not particularly limited, and adipic acid, sebacic acid, phthalic acid, terephthalic acid, 1,4-cyclohexyl dicarboxylic acid, and the like can be used.

  As glycol, ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol and the like can be used.

  These dibasic acids and glycols may be used alone or in combination of two or more.

  The polyhydric alcohol ester plasticizer comprises an ester of a divalent or higher aliphatic polyhydric alcohol and a monocarboxylic acid. Examples of preferred polyhydric alcohols include the following, but the present invention is not limited to these.

  Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, 2-n-butyl-2-ethyl-1,3- Propanediol, galactitol, mannitol, 3-methylpentane-1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, xylitol, and the like can be raised.

  In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable. There is no restriction | limiting in particular as monocarboxylic acid used for polyhydric alcohol ester, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. can be used.

  Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention. Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto.

  As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. It is more preferable that it is C1-C20, and it is especially preferable that it is C1-C10.

  When acetic acid is contained, the compatibility with the cellulose ester is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.

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

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

  Examples of preferred aromatic monocarboxylic acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and two or more benzene rings such as biphenyl carboxylic acid, naphthalene carboxylic acid, and tetralin carboxylic acid. Aromatic monocarboxylic acids or derivatives thereof can be raised.

  Particularly preferred is benzoic acid. The molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably in the range of 300 to 1500, and more preferably in the range of 350 to 750.

  The larger one is preferable in terms of improvement in retention, and the smaller one is preferable in terms of moisture permeability and compatibility with cellulose ester.

  The carboxylic acid used for the polyhydric alcohol ester may be one kind or a mixture of two or more kinds.

  Moreover, all the OH groups in the polyhydric alcohol may be esterified with carboxylic acid, or a part of the OH groups may be left as they are. These plasticizers are preferably used alone or in combination. The amount of these plasticizers used is preferably from 1 to 20% by mass, particularly preferably from 3 to 13% by mass, based on the cellulose ester, in terms of film performance, processability and the like.

(UV absorber)
The base film may contain an ultraviolet absorber. Next, the ultraviolet absorber will be described.

  As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties.

  Specific examples include, but are not limited to, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex compounds, and the like.

  Although the following specific examples are given as a benzotriazole type ultraviolet absorber, this invention is not limited to these.

UV-1: 2- (2'-hydroxy-5'-methylphenyl) benzotriazole UV-2: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole UV-3 : 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole UV-4: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl)- 5-Chlorobenzotriazole UV-5: 2- (2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl) benzotriazole UV-6: 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol)
UV-7: 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole UV-8: 2- (2H-benzotriazol-2-yl) -6 (Linear and side chain dodecyl) -4-methylphenol (TINUVIN171, manufactured by Ciba Japan)
UV-9: Octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl- Mixture of 4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate (TINUVIN109, manufactured by Ciba Japan)
Moreover, although the following specific examples are shown as a benzophenone series ultraviolet absorber, this invention is not limited to these.

UV-10: 2,4-dihydroxybenzophenone UV-11: 2,2'-dihydroxy-4-methoxybenzophenone UV-12: 2-hydroxy-4-methoxy-5-sulfobenzophenone UV-13: Bis (2-methoxy -4-hydroxy-5-benzoylphenylmethane)
As the UV absorber, a benzotriazole UV absorber and a benzophenone UV absorber, which are highly transparent and excellent in preventing the deterioration of polarizing plates and liquid crystals, are preferable, and benzotriazole UV absorption with less unnecessary coloring is preferable. An agent is particularly preferably used.

  In addition, an ultraviolet absorber having a distribution coefficient of 9.2 or more described in Japanese Patent Application No. 11-295209 can be used, and in particular, an ultraviolet absorber having a distribution coefficient of 10.1 or more is the surface quality of the base film. Is preferable from the standpoint that it can be maintained well.

  Moreover, the polymer ultraviolet absorber (or the general formula (1) or the general formula (2) of JP-A-6-148430 and the general formulas (3), (6) and (7) described in Japanese Patent Application No. 2000-156039 (or A UV-absorbing polymer) is also preferably used. As a polymer ultraviolet absorber, PUVA-30M (manufactured by Otsuka Chemical Co., Ltd.) and the like are commercially available.

  Moreover, you may give an internal haze to a base film.

(particle)
Internal haze, for example, by adding particles with a refractive index different from that of the base film to the base film and controlling the addition amount, particle size, etc., generating haze due to internal scattering, and adjusting this Can be achieved.

  The particles are classified into inorganic particles and organic particles. The inorganic particles are not particularly limited, and examples thereof include silicon oxide, titanium oxide, aluminum oxide, zinc oxide, tin oxide, calcium carbonate, barium sulfate, talc, kaolin, and calcium sulfate.

  The organic particles are not particularly limited. For example, fluorinated acrylic resin powder, polystyrene resin powder, polymethacrylic acid methyl acrylate resin powder, silicone resin powder, polycarbonate resin powder, acrylic styrene resin powder, benzoguanamine resin Examples thereof include powder, melamine resin powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, and polyfluoroethylene resin powder.

  These inorganic particles and organic particles may be used in combination of two or more different types and average particle diameters, and those obtained by surface-treating the surface of the particles with an organic substance are also preferably used.

  Particularly preferred inorganic particles are silicon dioxide. Specific examples of silicon dioxide include Aerosil 200V, Aerosil R972V, Aerosil R972, R974, R812, 200, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.), Seahoster KE-P10, Seahoster KE-P30, Commercial products having trade names such as Seahoster KE-P50 (above, manufactured by Nippon Shokubai Co., Ltd.), Silo Hovic 100 (manufactured by Fuji Silysia), Nip seal E220A (manufactured by Nippon Silica Industry), Admafine SO (manufactured by Admatechs), etc. Can be preferably used.

  The shape of the particles can be used without any particular limitation, such as indefinite shape, needle shape, flat shape, and spherical shape. However, the use of spherical particles is particularly preferable because it is easy to adjust the haze.

  As the organic particles, fluorine-containing acrylic resin particles are particularly suitable.

  The fluorine-containing acrylic resin particles are, for example, particles formed from a fluorine-containing acrylic ester or methacrylic ester monomer or polymer. Specific examples of the fluorine-containing acrylic ester or methacrylic ester include 1H, 1H, 3H-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, 1H, 1H, 7H- Dodecafluoroheptyl (meth) acrylate, 1H, 1H, 9H-hexadecafluorononyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (Meth) acrylate, 2- (perfluorobutyl) ethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2-perfluorodecylethyl (Meth) acrylate, 3-perf Orobutyl-2-hydroxypropyl (meth) acrylate, 3-perfluorohexyl-2-hydroxypropyl (meth) acrylate, 3-perfluorooctyl-2-hydroxypropyl (meth) acrylate, 2- (perfluoro-3-methylbutyl ) Ethyl (meth) acrylate, 2- (perfluoro-5-methylhexyl) ethyl (meth) acrylate, 2- (perfluoro-7-methyloctyl) ethyl (meth) acrylate, 3- (perfluoro-3-methylbutyl) 2-hydroxypropyl (meth) acrylate, 3- (perfluoro-5-methylhexyl) -2-hydroxypropyl (meth) acrylate, 3- (perfluoro-7-methyloctyl) -2-hydroxypropyl (meth) Acrylate, 1H-1- ( (Rifluoromethyl) trifluoroethyl (meth) acrylate, 1H, 1H, 3H-hexafluorobutyl (meth) acrylate, trifluoroethyl methacrylate, tetrafluoropropyl methacrylate, perfluorooctylethyl acrylate, 2- (perfluorobutyl) ethyl In addition, among the fluorine-containing acrylic resin particles, particles made of 2- (perfluorobutyl) ethyl-α-fluoroacrylate, fluorine-containing polymethyl methacrylate particles, and fluorine-containing methacrylic acid are cross-linked. Particles copolymerized with a vinyl monomer in the presence of an agent are preferred, and fluorine-containing polymethyl methacrylate particles are more preferred.

  The vinyl monomer copolymerizable with fluorine-containing (meth) acrylic acid is not particularly limited as long as it has a vinyl group. Specifically, alkyl methacrylates such as methyl methacrylate and butyl methacrylate, and methyl acrylate. , Alkyl acrylates such as ethyl acrylate, and styrenes such as styrene and α-methylstyrene. These may be used alone or in combination.

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

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

  As a commercial item, commercial items, such as Negami Industries make: MF-0043, are mentioned. These fluorine-containing acrylic resin particles may be used alone or in combination of two or more. Moreover, the state of these fluorine-containing acrylic resin particles may be added in any state such as powder or emulsion.

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

  Examples of polystyrene particles include commercially available products such as those manufactured by Soken Chemicals; SX-130H, SX-200H, SX-350H), Sekisui Plastics, SBX series (SBX-6, SBX-8).

  Examples of the melamine-based particles include a product made by Nippon Shokubai: benzoguanamine / melamine / formaldehyde condensate (trade name: eposter, grade; M30, product name: eposter GP, grade; H40 to H110), and made by Nippon Shokubai: melamine / formaldehyde condensation. Commercial products such as products (trade name: eposter, grade; S12, S6, S, SC4) can be mentioned. Moreover, the core-shell type spherical composite cured melamine resin particles in which the core is made of a melamine resin and the shell is filled with silica are also exemplified. Specifically, it can be prepared by the method described in JP-A-2006-171033, and commercially available products such as melamine resin / silica composite particles (trade name: Opto Beads) manufactured by Nissan Chemical Industries, Ltd. can be mentioned.

  Examples of the poly ((meth) acrylate) particles and the crosslinked poly ((meth) acrylate) particles include, for example, Soken Chemicals; MX150, MX300, Nippon Shokubai; Eposta MA, Grades; MA1002, MA1004, MA1006, MA1010, Epostor MX (Emulsion), grade: MX020W, MX030W, MX050W, MX100W, manufactured by Sekisui Plastics: MBX series (MBX-8, MBX12), and other commercial products.

  Specific examples of the crosslinked poly (acryl-styrene) particles include commercial products such as FS-201 and MG-351 manufactured by Nippon Paint. Examples of the benzoguanamine-based particles include a product manufactured by Nippon Shokubai Co., Ltd .: benzoguanamine / formaldehyde condensate (trade name: eposter, grade; L15, M05, MS, SC25).

  The average particle size of the particles added to the base film is preferably 0.3 to 1 μm, more preferably 0.4 to 0.7 μm.

  The average particle size can be determined by visual observation from an image photograph of secondary electron emission obtained by scanning electron microscope (SEM) or the like of 500 particles or by image processing, or by dynamic light scattering, static It can be measured by a particle size distribution meter using an automatic light scattering method or the like.

  The average particle diameter here refers to the number average particle diameter. In addition, an average particle diameter means the average particle diameter of an aggregate, when particle | grains are the aggregates of a primary particle. Moreover, when a particle is not spherical, it means the diameter of a circle corresponding to the projected area.

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

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

  In addition, the refractive index difference between the resin used for the base film and the particles is preferably 0.02 or more and 0.20 or less in order to increase the internal haze using the light scattering effect. A more preferable range of the refractive index difference is 0.05 or more and 0.15 or less.

  The content of the inorganic or organic particles is preferably 1 part by mass to 30 parts by mass with respect to 100 parts by mass of the resin for producing the base film, and more preferably 5 parts by mass to 25 parts by mass for obtaining internal haze. Part.

  The particles may be dispersed together with cellulose ester, other additives and an organic solvent when preparing the composition (dope) for producing the base film, or may be dispersed alone in the solution. .

  As a method for dispersing the particles, it is preferable that the particles are preliminarily dispersed in an organic solvent and then finely dispersed by a disperser (high pressure disperser) having a high shearing force.

  As a dope preparation method, it is preferable to disperse particles in a large amount of an organic solvent, merge with a cellulose ester solution, and mix with an in-line mixer to form a dope. In this case, an ultraviolet absorbent may be added to the particle dispersion to form an ultraviolet absorbent liquid.

  In addition, in the preparation of a solution composed of cellulose ester or cellulose ester resin and an acrylic resin, the above-mentioned deterioration inhibitor and ultraviolet absorber may be added together with a solvent, cellulose ester, cellulose ester resin and acrylic resin, It may be added during or after solution preparation.

(Organic solvent)
The dope preferably contains an organic solvent from the viewpoint of film forming properties and productivity. Any organic solvent can be used without limitation as long as it dissolves cellulose ester and other additives simultaneously. For example, methylene chloride, methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3 , 3-hexafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1,1,1,3 , 3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol, nitroethane and the like. Among these organic solvents, methylene chloride, methyl acetate, ethyl acetate, and acetone are preferably used.

  The dope preferably contains 1 to 40% by mass of an alcohol having 1 to 4 carbon atoms in addition to the organic solvent. When the proportion of alcohol in the dope increases, the web gels, facilitating peeling from the metal support, and when the proportion of alcohol is small, the role of promoting dissolution of cellulose esters in non-chlorine organic solvent systems There is also. Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol. Ethanol is preferred because of the stability, boiling point of these inner dopes, relatively good drying, and no toxicity.

  The concentration of the cellulose ester in the dope is preferably adjusted to 15 to 40% by mass, and the dope viscosity is preferably adjusted to a range of 10 to 50 Pa · s in order to obtain good film surface quality.

(Solution casting method)
Cellulose ester film, and cellulose ester resin / acrylic resin film are produced by a solution casting method. A step of preparing a dope by dissolving cellulose ester or cellulose ester resin / acrylic resin and an additive in a solvent, and belting the dope A step of casting on a metal support in the form of a drum or a drum, a step of drying the cast dope as a web, a step of peeling from the metal support, a step of stretching or maintaining the width, a step of further drying, and a finished film It is performed by a winding process.

  The concentration of cellulose ester in the dope, and the concentration of cellulose ester resin / acrylic resin is preferably higher because the drying load after casting on a metal support can be reduced. The load increases, and the filtration accuracy deteriorates. As a density | concentration which makes these compatible, 10-35 mass% is preferable, More preferably, it is 15-25 mass%.

  The metal support in the casting (casting) step preferably has a mirror-finished surface, and a stainless steel belt or a drum whose surface is plated with a casting is preferably used as the metal support.

  The cast width can be 1 to 4 m. The surface temperature of the metal support in the casting step is set to −50 ° C. to a temperature at which the solvent boils and does not foam. A higher temperature is preferred because the web can be dried faster, but if it is too high, the web may foam or the flatness may deteriorate.

  The preferable support temperature is appropriately determined at 0 to 100 ° C, and more preferably 5 to 30 ° C. Alternatively, it is also a preferable method that the web is gelled by cooling and peeled from the drum in a state containing a large amount of residual solvent.

  The method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing hot air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short.

  When using warm air, considering the temperature drop of the web due to the latent heat of vaporization of the solvent, while using warm air above the boiling point of the solvent, there may be cases where wind at a temperature higher than the target temperature is used while preventing foaming. .

  In particular, it is preferable to perform drying efficiently by changing the temperature of the support and the temperature of the drying air during the period from casting to peeling.

  In order for the cellulose ester film to exhibit good flatness, the residual solvent amount when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass or 60 to 130% by mass. Especially preferably, it is 20-30 mass% or 70-120 mass%.

  The amount of residual solvent is defined by the following formula.

Residual solvent amount (% by mass) = {(MN) / N} × 100
Note that M is the mass of a sample collected during or after the production of the web or film, and N is the mass after heating M at 115 ° C. for 1 hour.

  Further, in the drying step of the cellulose ester film or the film made of cellulose ester resin / acrylic resin, it is preferable that the web is peeled off from the metal support and further dried to make the residual solvent amount 1% by mass or less. Is 0.1% by mass or less, particularly preferably 0 to 0.01% by mass.

  In the film drying process, generally, a roll drying method (a method in which a plurality of rolls arranged on the upper and lower sides are alternately passed through and dried) or a method of drying while transporting the web by a tenter method is adopted.

(Melting method)
The cellulose ester film and the cellulose ester resin / acrylic resin film are also preferably formed by a melt film forming method. In the melt film-forming method, a composition containing a cellulose ester, a cellulose ester resin / acrylic resin, and an additive such as a plasticizer is heated and melted to a temperature showing fluidity, and then a melt containing a fluid cellulose ester. It means to cast.

  More specifically, the heat melting molding method can be classified into a melt extrusion molding method, a press molding method, an inflation method, an injection molding method, a blow molding method, a stretch molding method, and the like.

  Among these, in order to obtain a cellulose ester film excellent in mechanical strength and surface accuracy, and a cellulose ester resin / acrylic resin film, the melt extrusion method is excellent.

  It is preferable that a plurality of raw materials used for melt extrusion are usually kneaded in advance and pelletized.

  Pelletization may be performed by a known method. For example, dry cellulose ester, plasticizer, and other additives are fed to an extruder with a feeder and kneaded using a single-screw or twin-screw extruder, and formed into a strand from a die. It can be done by extrusion, water cooling or air cooling and cutting.

  The additives may be mixed before being supplied to the extruder, or may be supplied by individual feeders.

  A small amount of additives such as particles and antioxidants are preferably mixed in advance in order to mix uniformly.

  The extruder is preferably processed at as low a temperature as possible so as to be able to be pelletized so that the shear force is suppressed and the resin does not deteriorate (decrease in molecular weight, coloring, gel formation, etc.). For example, in the case of a twin screw extruder, it is preferable to rotate in the same direction using a deep groove type screw. From the uniformity of kneading, the meshing type is preferable.

  A film is formed using the pellets obtained as described above. Of course, the raw material powder can be directly fed to the extruder by a feeder without being pelletized to form a film as it is.

  Using a single or twin screw extruder, the pellets are melted at a temperature of about 200 to 300 ° C., filtered through a leaf disk filter, etc. to remove foreign matter, and then formed into a film from a T die. And solidified on a cooling roll.

  When introducing from the supply hopper to the extruder, it is preferable to prevent oxidative decomposition or the like under vacuum, reduced pressure, or inert gas atmosphere.

  The extrusion flow rate is preferably performed stably by introducing a gear pump or the like. Further, a stainless fiber sintered filter is preferably used as a filter used for removing foreign substances.

  The stainless steel fiber sintered filter is a united stainless steel fiber body that is intricately intertwined and compressed, and the contact points are sintered and integrated. The density of the fiber is changed depending on the thickness of the fiber and the amount of compression, and the filtration accuracy is improved. Can be adjusted.

  Additives such as plasticizers and particles may be mixed with the resin in advance, or may be kneaded in the middle of the extruder. In order to add uniformly, it is preferable to use a mixing apparatus such as a static mixer.

  The film temperature on the touch roll side when the film is nipped between the cooling roll and the elastic touch roll is preferably Tg or more and Tg + 110 ° C. or less of the film. A well-known roll can be used for the roll which has the elastic body surface used for such a purpose.

  The elastic touch roll is also called a pinching rotator. As the elastic touch roll, a touch roll disclosed in registered patent 3194904, registered patent 3422798, Japanese Patent Laid-Open No. 2002-36332, Japanese Patent Laid-Open No. 2002-36333, or the like can be preferably used. These can also use what is marketed.

  When peeling the film from the cooling roll, it is preferable to control the tension to prevent deformation of the film.

  Moreover, it is preferable that the film obtained as described above is stretched by the stretching operation after passing through the step of contacting the cooling roll.

  As a method of stretching, a known roll stretching machine or tenter can be preferably used. The stretching temperature is usually preferably performed in the temperature range of Tg to Tg + 60 ° C. of the resin constituting the film.

Prior to winding, the ends may be slit and cut to the width of the product, and knurling (embossing) may be applied to both ends to prevent sticking or scratching during winding. The knurling method can process a metal ring having an uneven pattern on its side surface by heating or pressing. In addition, since the film has deform | transformed and cannot use as a product normally, the holding | grip part of the clip of both ends of a film is cut out and reused.
<Layers other than base film and low refractive index layer>
The hard coat layer, antistatic layer, and back coat layer that can be provided in the antireflection film of the present invention will be described.

<Hard coat layer>
In the antireflection film according to the present invention, it is possible to provide a layer containing an actinic radiation curable resin as a hard coat layer between the base film and the low refractive index layer. This is preferable because the film is less likely to be scratched in the step of forming the polarizing plate described later.

  The actinic radiation curable resin layer according to the present invention refers to a layer mainly composed of a resin that cures through a crosslinking reaction upon irradiation with actinic rays (also referred to as actinic energy rays) such as ultraviolet rays and electron beams. As the actinic radiation curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and an actinic radiation curable resin layer is formed by curing by irradiation with actinic radiation such as ultraviolet rays or electron beams. The

  Typical examples of the actinic radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, but the resin that is cured by ultraviolet irradiation is excellent in mechanical film strength (abrasion resistance, pencil hardness). preferable.

  As the ultraviolet curable resin, for example, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy resin is preferable. Used. Of these, ultraviolet curable acrylate resins are preferred.

  As the ultraviolet curable acrylate resin, a polyfunctional acrylate is preferable. The polyfunctional acrylate is preferably selected from the group consisting of pentaerythritol polyfunctional acrylate, dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate, and dipentaerythritol polyfunctional methacrylate. Here, the polyfunctional acrylate is a compound having two or more acryloyloxy groups and / or methacryloyloxy groups in the molecule.

  Examples of the polyfunctional acrylate monomer include ethylene glycol diacrylate, diethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, and tetramethylolmethane triacrylate. , Tetramethylolmethane tetraacrylate, pentaglycerol triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, glycerol triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol Lithol hexaacrylate, tris (acryloyloxyethyl) isocyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, Tetramethylol methane trimethacrylate, tetramethylol methane tetramethacrylate, pentaglycerol trimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, glycerol trimethacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetramethacrylate Acrylate, dipentaerythritol penta methacrylate, dipentaerythritol hexa methacrylate, isobornyl acrylate and the like preferably. These compounds are used alone or in admixture of two or more. Moreover, oligomers, such as a dimer and a trimer of the said monomer, may be sufficient.

  The hard coat layer preferably contains a photopolymerization initiator to accelerate the curing of the actinic radiation curable resin. The amount of the photopolymerization initiator is preferably contained in a mass ratio of photopolymerization initiator: active ray curable resin = 20: 100 to 0.01: 100.

  Specific examples of the photopolymerization initiator include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof, but are not particularly limited thereto.

  The cured resin layer thus obtained may contain fine particles of an inorganic compound or an organic compound in order to adjust the scratch resistance, slipperiness and refractive index.

  As inorganic fine particles, silicon oxide, titanium oxide, aluminum oxide, tin oxide, indium oxide, ITO, zinc oxide, zirconium oxide, magnesium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated silicic acid Mention may be made of calcium, aluminum silicate, magnesium silicate and calcium phosphate. In particular, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, magnesium oxide and the like are preferably used.

  Organic particles include polymethacrylic acid methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, and melamine resin. Powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, polyfluoroethylene resin powder, or the like can be added.

  Preferred fine particles include crosslinked polystyrene particles (for example, SX-130H, SX-200H, SX-350H manufactured by Soken Chemical), polymethyl methacrylate-based particles (for example, MX150, MX300 manufactured by Soken Chemical), and fluorine-containing acrylic resin fine particles. . Examples of the fluorine-containing acrylic resin fine particles include commercial products such as FS-701 manufactured by Nippon Paint. Examples of the acrylic particles include Nippon Paint: S-4000, and examples of the acrylic-styrene particles include Nippon Paint: S-1200, MG-251.

  The average particle diameter of these fine particle powders is not particularly limited, but is preferably 0.01 to 5 μm, more preferably 0.1 to 5.0 μm, and particularly preferably 0.1 to 4.0 μm. It is also preferable to contain two or more kinds of fine particles having different particle diameters. The proportion of the ultraviolet curable resin composition and the fine particles is desirably blended so as to be 0.1 to 30 parts by mass with respect to 100 parts by mass of the resin composition.

  The average particle diameter of the fine particles can be measured by, for example, a laser diffraction particle size distribution measuring device.

  These hard coat layers are coated using a known method such as a gravure coater, dip coater, reverse coater, wire bar coater, die coater, ink jet method, and the like. And can be formed by UV curing.

  The coating amount is suitably 0.1 to 40 μm, preferably 0.5 to 30 μm, as the wet film thickness. The dry film thickness is from 0.1 to 30 μm, preferably from 1 to 20 μm, particularly preferably from 6 to 15 μm.

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

Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually 5 to 500 mJ / cm ² , preferably 5 to 200 mJ / cm ² .

  Moreover, when irradiating actinic radiation, it is preferable to carry out while applying tension | tensile_strength in the conveyance direction of a film, More preferably, it is performing applying tension | tensile_strength also in the width direction. The tension to be applied is preferably 30 to 300 N / m. The method for applying tension is not particularly limited, and tension may be applied in the transport direction on the back roll, or tension may be applied in the width direction or biaxial direction by a tenter. Thereby, a film having further excellent flatness can be obtained.

  Furthermore, the hard coat layer of the present invention may contain a conductive agent in order to impart antistatic properties, and preferred conductive agents include metal oxide particles or π-conjugated conductive polymers. Moreover, the ionic liquid mentioned later is also preferably used as a conductive compound.

  First, the metal oxide particles will be described.

  The type of metal oxide particles is not particularly limited, and Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P, and S A metal oxide having at least one element selected from can be used. Further, these metal oxide particles may be doped with a trace amount of atoms such as Al, In, Sn, Sb, Nb, a halogen element, and Ta.

  A mixture of these may also be used. In the present invention, at least one metal oxide selected from antimony oxide, tin oxide, zinc oxide, tin-containing indium oxide (ITO), antimony-containing tin oxide (ATO), phosphorus-containing tin oxide (PTO), and zinc antimonate. It is preferable to use physical particles as the main component.

  In particular, it is preferable to contain either phosphorus-containing tin oxide (PTO) or zinc antimonate particles.

  The average particle diameter of the primary particles of these metal oxide particles is in the range of 10 nm to 200 nm, more preferably 20 to 150 nm, and particularly preferably 30 to 100 nm.

  The average particle diameter of the metal oxide particles can be measured from an electron micrograph using a scanning electron microscope (SEM) or the like. Further, it may be measured by a particle size distribution meter using a dynamic light scattering method or a static light scattering method.

  If the particle size is too small, aggregation tends to occur and the dispersibility deteriorates. If the particle size is too large, the haze is remarkably increased. The shape of the metal oxide particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape, a needle shape, or an indefinite shape.

  The metal oxide particles may be surface treated with an organic compound. By modifying the surface of the metal oxide particles with an organic compound, the dispersion stability in an organic solvent is improved, the dispersion particle size can be easily controlled, and aggregation and sedimentation over time can be suppressed. .

  For this reason, the surface modification amount with a preferable organic compound is 0.1-5 mass% with respect to metal oxide particle, More preferably, it is 0.5-3 mass%.

  Examples of the organic compound used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Among these, the silane coupling agent mentioned later is preferable. Two or more surface treatments may be combined.

  The metal oxide particles are supplied to a coating solution for forming a hard coat layer in a dispersion state dispersed in a medium. As a dispersion medium for metal oxide particles, it is preferable to use a liquid having a boiling point of 60 to 170 ° C.

  Specific examples of the dispersion solvent include water, alcohol (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ketone alcohol (eg, diacetone alcohol). , Esters (eg, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene) Chloride, chloroform, carbon tetrachloride), aromatic hydrocarbons (eg, benzene, toluene, xylene), amides (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ethers (eg, diethyl ether, dioxane, Tiger hydrofuran), ether alcohols (e.g., 1-methoxy-2-propanol), propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate. Of these, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol and isopropanol are particularly preferable.

  The metal oxide particles can be dispersed in the medium using a disperser. Examples of the disperser include a sand grinder mill (eg, a bead mill with pins), a high-speed impeller mill, a pebble mill, a roller mill, an attritor, and a colloid mill. A sand grinder mill and a high-speed impeller mill are particularly preferred.

  Further, preliminary dispersion processing may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder. It is also preferable to contain a dispersant.

  Further, metal oxide particles having a core / shell structure may be included. One layer of the shell may be formed around the core, or a plurality of layers may be formed in order to further improve the light resistance. The core is preferably completely covered by the shell.

  Next, the π-conjugated conductive polymer will be described.

  The π-conjugated conductive polymer used in the present invention can be used as long as the organic polymer has a main chain composed of a π-conjugated system. Examples thereof include polythiophenes, polypyrroles, polyanilines, polyphenylenes, polyacetylenes, polyphenylene vinylenes, polyacenes, polythiophene vinylenes, and copolymers thereof. From the viewpoint of ease of polymerization and stability, polythiophenes, polypyrroles, and polyanilines are preferred.

  The π-conjugated conductive polymer can provide sufficient conductivity and solubility in a binder resin even if it is not substituted, but in order to further improve conductivity and solubility, an alkyl group, a carboxy group, a sulfo group, an alkoxy group. A functional group such as a group, a hydroxy group, or a cyano group may be introduced.

  Specific examples of such π-conjugated conductive polymers include polythiophene, poly (3-methylthiophene), poly (3-ethylthiophene), poly (3-propylthiophene), poly (3-butylthiophene), poly (3-hexylthiophene), poly (3-octylthiophene), poly (3-decylthiophene), poly (3-dodecylthiophene), poly (3-bromothiophene), poly (3-chlorothiophene), poly (3 -Cyanothiophene), poly (3-phenylthiophene), poly (3,4-dimethylthiophene), poly (3,4-dibutylthiophene), poly (3-hydroxythiophene), poly (3-methoxythiophene), poly (3-ethoxythiophene), poly (3-butoxythiophene), poly (3-hexyloxythio) ), Poly (3-octyloxythiophene), poly (3-decyloxythiophene), poly (3-dodecyloxythiophene), poly (3,4-dihydroxythiophene), poly (3,4-dimethoxythiophene) , Poly (3,4-diethoxythiophene), poly (3,4-dipropoxythiophene), poly (3,4-dibutoxythiophene), poly (3,4-dihexyloxythiophene), poly (3,4 -Dioctyloxythiophene), poly (3,4-didecyloxythiophene), poly (3,4-didodecyloxythiophene), poly (3,4-ethylenedioxythiophene), poly (3,4-propylenedi) Oxythiophene), poly (3,4-butenedioxythiophene), poly (3-methyl-4-methoxythiophene), poly Li (3-methyl-4-ethoxythiophene), poly (3-carboxythiophene), poly (3-methyl-4-carboxythiophene), poly (3-methyl-4-carboxyethylthiophene), poly (3-methyl -4-carboxybutylthiophene), polypyrrole, poly (N-methylpyrrole), poly (3-methylpyrrole), poly (3-ethylpyrrole), poly (3-N-propylpyrrole), poly (3-butylpyrrole) ), Poly (3-octylpyrrole), poly (3-decylpyrrole), poly (3-dodecylpyrrole), poly (3,4-dimethylpyrrole), poly (3,4-dibutylpyrrole), poly (3- Carboxypyrrole), poly (3-methyl-4-carboxypyrrole), poly (3-methyl-4-carboxyethylpyrrole) Poly (3-methyl-4-carboxybutylpyrrole), poly (3-hydroxypyrrole), poly (3-methoxypyrrole), poly (3-ethoxypyrrole), poly (3-butoxypyrrole), poly (3-hexyl) Oxypyrrole), poly (3-methyl-4-hexyloxypyrrole), polyaniline, poly (2-methylaniline), poly (3-isobutylaniline), poly (2-anilinesulfonic acid), poly (3-anilinesulfone) Acid) and the like. Each of these may be used alone or two types of copolymers can be suitably used.

  A dopant component may be added to these π-conjugated conductive polymers. Examples of the dopant component include low molecular weight dopants such as halogens, Lewis acids, proton acids, transition metal halides, and polymers such as polyanions.

  A polyanion is a polymer having an anionic group that functions as a dopant for a π-conjugated conductive polymer, and is a substituted or unsubstituted polyalkylene, a substituted or unsubstituted polyalkenylene, a substituted or unsubstituted polyimide, a substituted or unsubstituted Substituted polyamides, substituted or unsubstituted polyesters, and copolymers thereof, comprising a structural unit having an anionic group and a structural unit having no anionic group.

  Polyalkylene is a polymer whose main chain is composed of repeating methylene, and examples thereof include polyethylene, polypropylene, polybutene, polypentene, polyhexene, polyvinyl alcohol, polyvinylphenol, polyacrylonitrile, polyacrylate, polystyrene, and the like.

  Polyalkenylene is a polymer composed of structural units containing one or more unsaturated bonds in the main chain. For example, propenylene, 1-methylpropenylene, 1-butylpropenylene, 1-decylpropenylene, 1-cyanopropene. Nylene, 1-phenylpropenylene, 1-hydroxypropenylene, 1-butenylene, 1-methyl-1-butenylene, 1-ethyl-1-butenylene, 1-octyl-1-butenylene, 2-methyl-1-butenylene, 2-ethyl-1-butenylene, 2-butyl-1-butenylene, 2-hexyl-1-butenylene, 2-octyl-1-butenylene, 2-decyl-1-butenylene, 2-phenyl-1-butenylene, 2- Butenylene, 1-methyl-2-butenylene, 1-ethyl-2-butenylene, 1-octyl-2-butenylene, 2 Methyl-2-butenylene, 2-ethyl-2-butenylene, 2-butyl-2-butenylene, 2-hexyl-2-butenylene, 2-octyl-2-butenylene, 2-decyl-2-butenylene, 2-phenyl- 2-butenylene, 2-propylenephenyl-2-butenylene, 2-pentenylene, 4-ethyl-2-pentenylene, 4-propyl-2-pentenylene, 4-butyl-2-pentenylene, 4-hexyl-2-pentenylene, 4 Examples include polymers containing one or more structural units selected from -cyano-2-pentenylene, 3-methyl-2-pentenylene, 3-phenyl-2-pentenylene, 4-hydroxy-2-pentenylene, hexenylene, and the like.

  As polyimide, pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, 2,2 ', 3,3'-tetracarboxydiphenyl ether dianhydride, 2,2'-[4 , 4'-di (dicarboxyphenyloxy) phenyl] propane dianhydride and the like, and a polyimide composed of a diamine such as oxydiamine, paraphenylenediamine, metaphenylenediamine, and benzophenonediamine.

  Examples of the polyamide include polyamide 6, polyamide 6,6, polyamide 6,10 and the like.

  Examples of the polyester include polyethylene terephthalate and polybutylene terephthalate.

  The anion group of the polyanion may be a functional group that can undergo chemical oxidation doping to the π-conjugated conductive polymer, but from the viewpoint of ease of production and stability, a monosubstituted sulfate group and a monosubstituted phosphate ester Group, phosphoric acid group, carboxy group, sulfo group and the like are preferable. Furthermore, from the viewpoint of the doping effect of the functional group on the π-conjugated conductive polymer, a sulfo group, a monosubstituted sulfate group, and a carboxy group are more preferable.

  Specific examples of polyanions include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polyacrylic acid ethyl sulfonic acid, polyacrylic acid butyl sulfonic acid, poly (2-acrylamido-2-methylpropane sulfonic acid), polyisoprene. Sulfonic acid, polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacryl carboxylic acid, polymethacryl carboxylic acid, poly (2-acrylamido-2-methylpropane carboxylic acid), polyisoprene carboxylic acid, polyacrylic acid, etc. Can be mentioned. These homopolymers may be used, or two or more types of copolymers may be used. Among these, polystyrene sulfonic acid, polyisoprene sulfonic acid, polyacrylic acid ethyl sulfonic acid, and polyacrylic acid butyl sulfonic acid are preferable. These polyanions have high compatibility with the binder resin, and can further increase the conductivity of the obtained conductive layer.

  In the present invention, in addition to the polyanion, the following donor or acceptor dopant can be used as long as the π-conjugated conductive polymer can be oxidized and reduced.

  Donor dopants include alkali metals such as sodium and potassium, alkaline earth metals such as calcium and magnesium, quaternary compounds such as tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, methyltriethylammonium and dimethyldiethylammonium. An amine compound etc. are mentioned.

Examples of the acceptor dopant include halogen compounds such as Cl ₂ , Br ₂ , I ₂ , ICl, IBr, and IF, Lewis acids such as PF ₅ , AsF ₅ , SbF ₅ , BF ₅ , BCl ₅ , BBr ₅ , and SO ₃ , Tetracyanoethylene, tetracyanoethylene oxide, tetracyanobenzene, dichlorodicyanobenzoquinone, tetracyanoquinodimethane, tetracyanoazanaphthalene and other organic cyano compounds, protonic acids, organometallic compounds, fullerenes, hydrogenated fullerenes, fullerene hydroxides, Carboxy oxide fullerene, sulfonated fullerene and the like can be used.

  Examples of the protonic acid include inorganic acids and organic acids. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, perchloric acid and the like. Moreover, organic carboxylic acid, organic sulfonic acid, etc. are mentioned as an organic acid.

  As organic carboxylic acid, what contains 1 or 2 or more of carboxy groups in aliphatic, aromatic, cycloaliphatic, etc. can be used. For example, formic acid, acetic acid, oxalic acid, benzoic acid, phthalic acid, maleic acid, fumaric acid, malonic acid, tartaric acid, citric acid, lactic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, nitroacetic acid, And triphenylacetic acid.

  As the organic sulfonic acid, aliphatic, aromatic, cycloaliphatic or the like containing one or more sulfo groups or a polymer containing sulfo groups can be used.

  Examples of those containing one sulfo group include methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 1-butanesulfonic acid, 1-hexanesulfonic acid, 1-heptanesulfonic acid, 1-octanesulfonic acid, 1-nonanesulfonic acid, 1-decanesulfonic acid, 1-pentadecanesulfonic acid, 2-bromoethanesulfonic acid, 3-chloro-2-hydroxypropanesulfonic acid, trifluoromethanesulfonic acid, trifluoroethanesulfonic acid, colistin methanesulfone Acid, 2-acrylamido-2-methylpropanesulfonic acid, aminomethanesulfonic acid, 1-amino-2-naphthol-4-sulfonic acid, 2-amino-5-naphthol-7-sulfonic acid, 3-aminopropanesulfonic acid N-cyclohexyl-3-aminopropanesulfone Benzenesulfonic acid, alkylbenzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, ethylbenzenesulfonic acid, propylbenzenesulfonic acid, butylbenzenesulfonic acid, pentylbenzenesulfonic acid, hexylbenzenesulfonic acid, heptylbenzenesulfonic acid, octylbenzene Sulfonic acid, nonylbenzenesulfonic acid, decylbenzenesulfonic acid, hexadecylbenzenesulfonic acid, 2,4-dimethylbenzenesulfonic acid, dipropylbenzenesulfonic acid, 4-aminobenzenesulfonic acid, o-aminobenzenesulfonic acid, m- Aminobenzenesulfonic acid, 4-amino-2-chlorotoluene-5-sulfonic acid, 4-amino-3-methylbenzene-1-sulfonic acid, 4-amino-5-methoxy-2-methylbenze Sulfonic acid, 2-amino-5-methylbenzene-1-sulfonic acid, 4-amino-2-methylbenzene-1-sulfonic acid, 5-amino-2-methylbenzene-1-sulfonic acid, 4-amino-3 -Methylbenzene-1-sulfonic acid, 4-acetamido-3-chlorobenzenesulfonic acid, 4-chloro-3-nitrobenzenesulfonic acid, p-chlorobenzenesulfonic acid, naphthalenesulfonic acid, methylnaphthalenesulfonic acid, propylnaphthalenesulfonic acid, butyl Naphthalenesulfonic acid, pentylnaphthalenesulfonic acid, 4-amino-1-naphthalenesulfonic acid, 8-chloronaphthalene-1-sulfonic acid, naphthalenesulfonic acid formalin polycondensate, melaminesulfonic acid formalin polycondensate, anthraquinonesulfonic acid, pyrene Examples include sulfonic acid It is done. These metal salts can also be used.

  Examples of those containing two or more sulfo groups include ethanedisulfonic acid, butanedisulfonic acid, pentanedisulfonic acid, decanedisulfonic acid, o-benzenedisulfonic acid, m-benzenedisulfonic acid, p-benzenedisulfonic acid, and toluenedisulfonic acid. , Xylene disulfonic acid, chlorobenzene disulfonic acid, fluorobenzene disulfonic acid, dimethylbenzene disulfonic acid, diethylbenzene disulfonic acid, aniline-2,4-disulfonic acid, aniline-2,5-disulfonic acid, 3,4-dihydroxy-1,3 Benzene disulfonic acid, naphthalene disulfonic acid, methyl naphthalene disulfonic acid, ethyl naphthalene disulfonic acid, pentadecyl naphthalene disulfonic acid, 3-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 1- Cetamide-8-hydroxy-3,6-naphthalenedisulfonic acid, 2-amino-1,4-benzenedisulfonic acid, 1-amino-3,8-naphthalenedisulfonic acid, 3-amino-1,5-naphthalenedisulfonic acid, 8-amino-1-naphthol-3,6-disulfonic acid, 4-amino-5-naphthol-2,7-disulfonic acid, 4-acetamido-4'-isothiocyanotostilbene-2,2'-disulfonic acid, Examples include 4-acetamido-4'-maleimidyl stilbene-2,2'-disulfonic acid, naphthalene trisulfonic acid, dinaphthylmethane disulfonic acid, anthraquinone disulfonic acid, and anthracene sulfonic acid. These metal salts can also be used.

  Moreover, you may contain an ionic liquid as a electrically conductive agent.

  The ionic liquid used in the present invention is a compound composed of an organic cation and an anion, and a compound having a melting point of 25 ° C. or lower is preferable. For example, examples of the organic cation include imidazolium, pyridinium, piperidinium, quaternary ammonium, and phosphonium.

  The conductive agent is preferably 0.01 part by weight to 300 parts by weight, and more preferably 0.1 part by weight to 100 parts by weight with respect to 100 parts by weight of the ionizing radiation curable resin used as the binder.

  The coating composition for forming the hard coat layer may contain a solvent. Examples of the organic solvent contained in the coating composition include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), These may be appropriately selected from esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents, or may be used by mixing them.

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

  The hard coat layer has a center line average roughness (Ra) defined by JIS B 0601 of 0.001 to 0.1 μm, or a fine hard coat layer and Ra is adjusted to 0.1 to 1 μm. An antiglare hard coat layer may also be used. The center line average roughness (Ra) is preferably measured by an optical interference type surface roughness measuring instrument, and can be measured, for example, using a non-contact surface fine shape measuring device WYKO NT-2000 manufactured by WYKO.

  Further, in the antiglare hard coat layer, an uneven shape may be formed on the hard coat surface by embossing with a roll or a master.

  Further, the hard coat layer preferably contains the following silicone surfactant or polyoxyether compound described in the low refractive index layer. These enhance the applicability. Moreover, it is preferable to add these components in 0.01-3 mass% with respect to the solid content component in a coating liquid.

  Examples of the polyoxyether compound include polyoxyethylene alkyl ether, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ether compounds such as polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene Polyoxyalkyl phenyl ether compounds such as ethylene octyl phenyl ether, polyoxyalkylene alkyl ether, polyoxyethylene higher alcohol ether, polyoxyethylene octyldodecyl ether and the like can be mentioned. Commercial products of polyoxyethylene alkyl ether include Emulgen 1108, Emulgen 1118S-70 (above, manufactured by Kao Corporation), and commercially available products of polyoxyethylene lauryl ether include Emulgen 103, Emulgen 104P, Emulgen 105, Emulgen 106, Emulgen 108, Emulgen 109P, Emulgen 120, Emulgen 123P, Emulgen 147, Emulgen 150, Emulgen 130K (above, manufactured by Kao Corporation), and polyoxyethylene cetyl ether are commercially available products of Emulgen 210P, Emulgen 220 (above, manufactured by Kao Corporation) As commercially available products of polyoxyethylene stearyl ether, Emulgen 220, Emulgen 306P (above, manufactured by Kao Corporation), and commercially available products of polyoxyalkylene alkyl ether include Examples of commercially available products of Rugen LS-106, Emulgen LS-110, Emulgen LS-114, Emulgen MS-110 (manufactured by Kao Corporation) polyoxyethylene higher alcohol ether include Emulgen 705, Emulgen 707, and Emulgen 709. .

  Among these nonionic polyoxyether compounds, polyoxyethylene oleyl ether compounds are preferable, and are compounds represented by the following general formula (3).

_{C 18 H 35 -O (C 2} H 4 O) n H ··· (3)
In the formula, n represents 2 to 40.

  The average addition number (n) of ethylene oxide with respect to the oleyl part is 2 to 40, preferably 2 to 10. Moreover, the compound of the said General formula (3) is obtained by making ethylene oxide and oleyl alcohol react.

  Specific products include Emulgen 404 [polyoxyethylene (4) oleyl ether], Emulgen 408 [polyoxyethylene (8) oleyl ether], Emulgen 409P [polyoxyethylene (9) oleyl ether], Emulgen 420 [polyoxy Ethylene (13) oleyl ether], Emulgen 430 [polyoxyethylene (30) oleyl ether] (above, manufactured by Kao Corporation), NOFBLEEAO-9905 (polyoxyethylene (5) oleyl ether) manufactured by NOF Corporation. Note that () represents the number n.

  The polyoxyether compounds may be used alone or in combination of two or more.

  The preferable content of the polyoxyether compound and the silicone surfactant in the hard coat layer is preferably 0.1 to 8.0% by mass, more preferably 0.2 to 4.0% by mass in terms of the total content of both. %, It is stably present in the hard coat layer by adding in this range.

  Further, a fluorine surfactant, an acrylic copolymer, an acetylene glycol compound or a nonionic surfactant, a radical polymerizable nonionic surfactant, and the like may be used in combination.

  Nonionic surfactants include polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyalkyl ester compounds such as polyoxyethylene monooleate, sorbitan monolaurate, sorbitan monostearate, sorbitan monooleate, etc. Sorbitan ester compounds, and the like.

  Examples of the acetylene glycol compounds include Surfinol 104E, Surfinol 104PA, Surfinol 420, Surfinol 440, and Dynal 604 (manufactured by Nissin Chemical Industry Co., Ltd.).

  Examples of the radical polymerizable nonionic surfactant include polyoxyalkylene alkylphenyl ether (meth) acrylates such as RMA-564, RMA-568, and RMA-1114 (above, trade name, manufactured by Nippon Emulsifier Co., Ltd.). Examples thereof include system polymerizable surfactants.

  Further, the hard coat layer may contain a polyfunctional thiol compound as a curing aid, for example, 1,4-bis (3-mercaptobutyryloxy) butane, pentaerythritol tetrakis (3-mercaptobutyrate), 1 3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione and the like. Moreover, as a commercial item, Showa Denko Co., Ltd. brand name Karenz MT series etc. are mentioned. The polyfunctional thiol compound is preferably added in the range of 0.01 to 50 parts by mass, more preferably 0.05 to 30 parts by mass with respect to 100 parts by mass of the ultraviolet curable resin. By adding in this range, it acts suitably as a curing aid, and also exists stably in the hard coat layer.

  The hard coat layer may have a multilayer structure of two or more layers. One of the layers may be, for example, a so-called clear hard coat layer that does not contain metal oxide particles, and a color tone adjusting agent (dye or pigment, etc.) having a color tone adjusting function as a color correction filter for various display elements. ), Or may contain an electromagnetic wave blocking agent or an infrared absorber so as to have each function.

<Back coat layer>
In the antireflection film of the present invention, a back coat layer may be provided on the surface of the base film opposite to the side on which the hard coat layer and the low refractive index layer are provided. The back coat layer is provided in order to correct curling caused by providing a hard coat layer or a low refractive index layer. That is, the degree of curling can be balanced by imparting the property of being rounded with the surface on which the backcoat layer is provided facing inward. The backcoat layer is preferably applied also as an antiblocking layer, and in this case, particles of an inorganic compound or an organic compound are added to the backcoat layer coating composition in order to provide an antiblocking function. Is preferred.

  As particles added to the back coat layer, examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, tin oxide, and oxidation. Mention may be made of indium, zinc oxide, ITO, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate.

  These particles include, for example, Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.), Seahoster KE-P10, KE-P30, KE- P50, KE-P100, KE-P150, and KE-P250 (above, manufactured by Nippon Shokubai Co., Ltd.) are commercially available and can be used.

  Examples of organic compounds include silicone resins, fluororesins, and acrylic resins. Silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 145, 3120 and 240 (manufactured by GE Toshiba Silicone Co., Ltd.) It is marketed by name and can be used.

  Among these, Aerosil 200V, Aerosil R972V, Seahoster KE-P30, KE-P50, and KE-P100 are particularly preferably used because they have a large anti-blocking effect while keeping haze low.

  The particles contained in the backcoat layer are 0.1 to 50% by mass, preferably 0.1 to 10% by mass, based on the binder. When the back coat layer is provided, the increase in haze is preferably 1.5% or less, more preferably 0.5% or less, and particularly preferably 0.1% or less.

  The coating composition used for coating the back coat layer preferably contains a solvent. Examples of the solvent include dioxane, acetone, methyl ethyl ketone, methyl isobutyl ketone, N, N-dimethylformamide, methyl acetate, ethyl acetate, trichloroethylene, methylene chloride, ethylene chloride, tetrachloroethane, trichloroethane, chloroform, water, methanol, ethanol, Examples include n-propyl alcohol, i-propyl alcohol, n-butanol, cyclohexanone, cyclohexanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, or hydrocarbons (toluene, xylene) and the like. .

  Examples of the resin used as the binder of the backcoat layer include vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, vinyl acetate resin, vinyl acetate-vinyl alcohol copolymer, partially hydrolyzed vinyl chloride-vinyl acetate copolymer. Polymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, etc. Vinyl polymer or copolymer, nitrocellulose, cellulose acetate propionate (preferably acetyl group substitution degree 1.8-2.3, propionyl group substitution degree 0.1-1.0), diacetyl cellulose, cellulose Cellulose derivatives such as acetate butyrate resin, maleic acid and / or Or acrylic acid copolymer, acrylic ester copolymer, acrylonitrile-styrene copolymer, chlorinated polyethylene, acrylonitrile-chlorinated polyethylene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, acrylic resin , Polyvinyl alcohol resin, polyvinyl acetal resin, polyvinyl butyral resin, urethane resin, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polyurethane resin, polyester resin, polyether resin, polyamide resin, amino resin, styrene-butadiene resin, butadiene-acrylonitrile Examples thereof include, but are not limited to, rubber resins such as resins, silicone resins, fluorine resins, and the like.

  For example, as an acrylic resin, Acrypet MD, VH, MF, V (manufactured by Mitsubishi Rayon Co., Ltd.), Hyperl M-4003, M-4005, M-4006, M-4202, M-5000, M-5001, M -4501 (manufactured by Negami Kogyo Co., Ltd.), Dialnal BR-50, BR-52, BR-53, BR-60, BR-64, BR-73, BR-75, BR-77, BR-79, BR- 80, BR-82, BR-83, BR-85, BR-87, BR-88, BR-90, BR-93, BR-95, BR-100, BR-101, BR-102, BR-105, BR-106, BR-107, BR-108, BR-112, BR-113, BR-115, BR-116, BR-117, BR-118, etc. (Mitsubishi Rayon Co., Ltd.) acrylic Fine methacrylic monomer various homopolymers and copolymers, etc. was prepared as a raw material are commercially available, may be selected as appropriate preferred from among these.

  For example, as a resin used as a binder, it is preferable to use a blend of cellulose ester such as cellulose diacetate and cellulose acetate prothionate and an acrylic resin, and the refractive index of the particles and the binder using particles made of an acrylic resin. By setting the difference to be less than 0 to 0.02, a highly transparent back coat layer can be obtained.

  The dynamic coefficient of friction of the backcoat layer is preferably 0.9 or less, particularly preferably 0.1 to 0.9.

  As a method for forming the backcoat layer, the above-described coating composition for forming the backcoat layer is formed using a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, or spray coating, inkjet coating, or the like. Although it is preferable to apply | coat to the surface of a transparent resin film with a wet film thickness of 1-100 micrometers, it is especially preferable that it is 5-30 micrometers.

  Moreover, a backcoat layer is formed by heat-drying after application | coating and carrying out the hardening process as needed. The content described in the low refractive index layer can be used for the curing treatment.

  The backcoat layer can be applied in two or more steps. Further, the backcoat layer may also serve as an easy adhesion layer for improving the adhesion with the polarizer.

<Antistatic layer>
Next, the antistatic layer will be described. The antistatic layer is provided between the film base and the hard coat layer, or between the hard coat layer and the low refractive index layer, thereby imparting antistatic properties to the antireflection film.

Specifically, the antistatic layer is a layer containing a conductive compound, and is preferably a layer having a surface specific resistance adjusted to 10 ¹³ Ω / cm ² (25 ° C., 55% RH) or less, More preferably, it is 10 ¹⁰ Ω / cm ² (25 ° C., 55% RH) or less, and particularly preferably 10 ⁹ Ω / cm ² (25 ° C., 55% RH) or less.

  Here, the measurement of the surface specific resistance is a value measured using a resistivity meter after conditioning the sample for 24 hours under the conditions of 25 ° C. and 55% RH. Moreover, as a resistivity meter device, for example, Hiresta UP MCP-HT450 manufactured by Mitsubishi Chemical Corporation can be used.

  In addition, when the overcoat layer is provided on the antistatic layer, the measurement of the surface specific resistance value is substantially the same as the surface specific resistance value of the outermost surface layer on the side where the antistatic layer is provided. It is defined as the surface specific resistance value.

  As the conductive compound, the aforementioned metal oxide fine particles, π-conjugated conductive polymer, ionic liquid, and the like are preferable compounds.

  The conductive compound is preferably 0.01 part by weight to 300 parts by weight, and more preferably 0.1 part by weight to 100 parts by weight with respect to 100 parts by weight of the ionizing radiation curable resin used as the binder.

  Next, the resin will be described. As the resin binder of the antistatic layer, a curable resin is preferable. Among them, an actinic radiation curable resin is preferable from the viewpoint of excellent film-forming properties and physical characteristics of the coating film and adhesion to the laminated film. As the actinic radiation curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and the actinic radiation curable resin layer is formed by curing by irradiating actinic radiation such as ultraviolet rays or electron beams. The Typical examples of the actinic radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, and an ultraviolet curable resin is particularly preferable.

  The curable resin also includes a thermosetting resin. Examples of the thermosetting resin include unsaturated polyester resins, epoxy resins, vinyl ester resins, phenol resins, thermosetting polyimide resins, thermosetting polyamide imides, and the like.

As unsaturated polyester resin, for example, orthophthalic acid resin, isophthalic acid resin, terephthalic acid resin, bisphenol resin, propylene glycol-maleic acid resin, dicyclopentadiene or derivatives thereof are introduced into the unsaturated polyester composition. Low-shrinkage resin with low styrene volatile resin and thermoplastic resin (polyvinyl acetate resin, styrene / butadiene copolymer, polystyrene, saturated polyester, etc.) with low molecular weight or film-forming wax compound added Reactive types such as bromating unsaturated polyester directly with Br ₂ or copolymerizing heptic acid or dibromoneopentyl glycol, halides such as chlorinated paraffin, tetrabromobisphenol, antimony trioxide, phosphorus compounds Combination Additive-type flame retardant resin that uses sesame or aluminum hydroxide as an additive, toughness resin that is hybridized with polyurethane or silicone, or toughened with IPN (high strength, high elastic modulus, high elongation), etc. is there.

  Examples of the epoxy resin include glycidyl ether type epoxy resins including bisphenol A type, novolak phenol type, bisphenol F type, brominated bisphenol A type, glycidyl amine type, glycidyl ester type, cyclic aliphatic type, and heterocyclic epoxy type. The special epoxy resin containing can be mentioned.

  Examples of vinyl ester resins include those obtained by dissolving an oligomer obtained by a ring-opening addition reaction between an ordinary epoxy resin and an unsaturated monobasic acid such as methacrylic acid in a monomer such as styrene. There are also special types such as vinyl monomers having vinyl groups at the molecular ends and side chains.

  Examples of vinyl ester resins of glycidyl ether type epoxy resins include bisphenol type, novolak type, brominated bisphenol type, etc., and special vinyl ester resins include vinyl ester urethane type, isocyanuric acid vinyl type, side chain vinyl ester type, etc. There is. The phenol resin is obtained by polycondensation using phenols and formaldehydes as raw materials, and there are a resol type and a novolac type.

  Examples of thermosetting polyimide resins include maleic acid-based polyimides such as polymaleimide amine, polyamino bismaleimide, bismaleimide, diallyl bisphenol-A resin, bismaleimide / triazine resin, nadic acid-modified polyimide, and acetylene-terminated polyimide. There is.

  The antistatic layer may contain the inorganic particles or organic particles. The average particle diameter of these particles is preferably 0.01 to 5 μm, more preferably 0.1 to 5.0 μm, and particularly preferably 0.1 to 4.0 μm. Moreover, you may contain 2 or more types of particle | grains from which a particle size differs. The particles are desirably blended so as to be 0.1 to 30 parts by mass with respect to 100 parts by mass of the curable resin.

  The antistatic layer has a vinyl group and a carboxyl group in the side chain of the polyurethane resin as a curing aid, has a weight average molecular weight of 10,000 to 30,000, and a double bond equivalent of 500 to 2,000. An acrylic polymer having a vinyl group in a polymer or a side chain of the polymer, having a weight average molecular weight (Mw) of 10,000 or more and 100,000 or less, a double bond equivalent of 1,000 or less, and a polymer Tg of −50 ° C. or more and 120 ° C. or less, Other functional thiol compounds may be included. Examples of other functional thiol compounds include 1,4-bis (3-mercaptobutyryloxy) butane, pentaerythritol tetrakis (3-mercaptobutyrate), 1,3,5-tris (3-mercaptobutyloxyethyl)- 1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione and the like. Commercially available products include Showa Denko Co., Ltd., trade name Karenz MT series, and the like.

  Moreover, you may contain a fluorine-acrylic copolymer resin. The fluorine-acrylic copolymer resin is a copolymer resin composed of a fluorine monomer and an acrylic monomer, and a block copolymer composed of a fluorine monomer segment and an acrylic monomer segment is particularly preferable. The molecular weight of the fluorine-acrylic copolymer resin is 5,000 to 1,000,000 in terms of number average molecular weight, preferably 10,000 to 300,000, and more preferably 10,000 to 100,000. In the production of the fluorine-acrylic copolymer resin, polymeric peroxide was used as a polymerization initiator. It can be produced by a known production process (for example, Japanese Patent Publication No. 5-41668 and Japanese Patent Publication No. 5-59942).

  Polymeric peroxide is a compound having two or more peroxy bonds in one molecule. As the polymer peroxide, one or more of various polymer peroxides described in JP-B-5-59942 can be used.

  As a commercial item of fluorine-acrylic copolymer resin, the brand name of Nippon Oil & Fat Co., Ltd. Modiper F-200, Modiper F-600, Modiper F-2020, etc. are mentioned.

  Further, the antistatic layer may contain the silicone surfactant described in the low refractive index layer, the fluorine compound, and the polyoxyether compound, or the nonionic surfactant described in the hard coat layer. It is preferable in that the productivity can be improved by giving high-speed coating suitability while improving the surface uniformity.

  The antistatic layer may contain a color tone adjusting agent (dye or pigment) having a color tone adjusting function as a color correction filter for various display elements, an electromagnetic wave blocking agent, an infrared absorber, or the like.

  The antistatic layer preferably contains a cellulose ester resin or an acrylic resin in order to maintain easy adhesion with the overcoat layer.

  Examples of the cellulose ester resin include cellulose derivatives such as cellulose diacetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose nitrate.

  Examples of the acrylic resin include Acrypet MD, VH, MF, V (Mitsubishi Rayon Co., Ltd.), Hyperl M4003, M-4005, M-4006, M-4202, M-5000, M -5001, M-4501 (manufactured by Negami Kogyo Co., Ltd.), Dialnal BR-50, BR-52, BR-53, BR-60, BR-64, BR-73, BR-75, BR-77, BR- 79, BR-80, BR-82, BR-83, BR-85, BR-87, BR-88, BR-90, BR-93, BR-95, BR-100, BR-101, BR-102, BR-105, BR-106, BR-107, BR-108, BR-112, BR-113, BR-115, BR-116, BR-117, BR-118, etc. (Mitsubishi Rayon Co., Ltd.) Various homopolymers and copolymers to produce Le and methacrylic monomer as a raw material is preferably used.

  The following solvents are preferably used in the coating composition for coating the antistatic layer. As the solvent, hydrocarbons, alcohols, ketones, esters, glycol ethers, and other solvents (methylene chloride) can be appropriately mixed and used, but are not particularly limited thereto.

  Examples of the hydrocarbons include benzene, toluene, xylene, hexane, cyclohexane and the like, and examples of alcohols include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, 2-butanol, tert- Examples include butanol, pentanol, 2-methyl-2-butanol, and cyclohexanol. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of esters include methyl formate, ethyl formate, Examples thereof include methyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, ethyl lactate, and methyl lactate. Examples of glycol ethers (C1 to C4) include methyl cellosolve, ethyl cellosolve, propylene glycol monomethyl ester. As terrestrial (PGME), propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether, or propylene glycol mono (C1-C4) alkyl ether esters, propylene glycol monomethyl Examples of ether acetate, propylene glycol monoethyl ether acetate, and other solvents include methylene chloride and N-methylpyrrolidone. Although not particularly limited to these, a solvent in which these are appropriately mixed is also preferably used.

As a coating method for the antistatic layer coating composition, a wet film thickness of 0 is applied to one surface of the base film using a gravure coater, dip coater, reverse coater, wire bar coater, die coater, spray coating, ink jet coating or the like. .1 to 100 μm, preferably 0.5 to 30 μm, and the dry film thickness is 0.1 to 30 μm, preferably 1 to 20 μm. After coating, it is dried by heating and cured as necessary. Formed. The curing process is performed by heat treatment or UV curing treatment. As a light source for UV curing treatment, any light source that generates ultraviolet rays can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually 5 to 500 mJ / cm ² , preferably 5 to 200 mJ / cm ² . Moreover, when irradiating actinic radiation, it is preferable to carry out while applying tension | tensile_strength in the conveyance direction of a film, More preferably, it is performing applying tension | tensile_strength also in the width direction. The tension to be applied is preferably 30 to 500 N / m. The method for applying tension is not particularly limited, and tension may be applied in the transport direction on the back roll, or tension may be applied in the width direction or biaxial direction by a tenter. Thereby, a film having further excellent flatness can be obtained. The antistatic layer may be a single layer or a multilayer structure of two or more layers.
<Coating and curing method of composition for antireflection layer>
The low refractive index layer, which is the antireflection layer of the present invention, is a composition that forms a low refractive index layer using a known method such as a gravure coater, dip coater, reverse coater, wire bar coater, die coater, and ink jet method. Is applied on each layer so as to have the above-described layer structure, and after coating, it is dried by heating and cured.

  Before applying the antireflection layer composition of the present invention, it is also preferable to subject each layer to a surface treatment such as corona discharge or plasma discharge.

  The coating amount is suitably 0.05 to 100 μm, preferably 0.1 to 50 μm, as the wet film thickness. Moreover, the solid content concentration of the composition is adjusted so that the dry film thickness becomes the above-mentioned film thickness.

As the curing method, the case of curing by light irradiation, exposure of the irradiation light is preferably from ^{10mJ / cm 2 ~10J / cm 2} , 100mJ / cm 2 ~500mJ / cm 2 is more preferable.

  Here, the wavelength range of the irradiated light is not particularly limited, but light having a wavelength in the ultraviolet region is preferably used. Specifically, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used.

  It is also possible to use a method of thermosetting by heating, and the heating temperature is preferably 50 to 300 ° C, preferably 60 to 250 ° C, more preferably 80 to 150 ° C.

  Moreover, after forming a low refractive index layer, you may include the process of heat-processing at the temperature of 50-160 degreeC. The period of the heat treatment may be appropriately determined depending on the set temperature. For example, if it is 50 ° C., it is preferably a period of 3 days or more and less than 30 days, and if it is 160 ° C., a range of 10 minutes or more and 1 day or less is preferable. .

  When each layer is formed by coating as described above, the substrate film is unwound in a roll shape with a width of 1.4 to 4 m, applied, dried and cured, and then rolled. It is preferable to be wound around.

  In addition, the antireflection film is manufactured by a manufacturing method in which a heat treatment is performed at a temperature of 50 to 160 ° C. in a state where the antireflection layer is laminated and then wound into a roll shape, and the antireflection film is applied in a long length. This is preferable from the viewpoint of efficiency and stability.

  The heat treatment period may be appropriately determined depending on the set temperature. For example, if the temperature is 50 ° C., it is preferably 3 days or more, less than 30 days, if the temperature is 160 ° C., 10 minutes or more, 1 day The following ranges are preferred.

  Usually, it is preferable to set it at a relatively low temperature so that the heat treatment effect at the outside of the winding, the center of the winding, and the core is not biased, and it is preferable to carry out at a temperature of about 50 to 60 ° C. for about 7 days.

  In order to stably perform the heat treatment, it is necessary to perform in a place where the temperature and humidity can be adjusted, and it is preferable to perform in a heat treatment chamber such as a clean room without dust.

  The winding core for winding the hard coat film and the antireflection film into a roll shape is not particularly limited as long as it is a cylindrical core, but is preferably a hollow plastic core, and the plastic material can withstand the heat treatment temperature. A heat resistant plastic is preferable, and examples thereof include resins such as phenol resin, xylene resin, melamine resin, polyester resin, and epoxy resin.

A thermosetting resin reinforced with a filler such as glass fiber is preferable. The number of windings on these winding cores is preferably 100 windings or more, more preferably 500 windings or more, and the winding thickness is preferably 5 cm or more.
<Low refractive index layer which is an antireflection layer>
The refractive index of the low refractive index layer of the present invention is lower than that of the substrate film as the support, and is preferably in the range of 1.20 to 1.49 at 23 ° C. and a wavelength of 550 nm, and is in the range of 1.25 to 1.44. More preferably, the range of 1.30 to 1.38 is particularly preferable.

The film thickness of the low refractive index layer is preferably 5 nm to 0.5 μm, more preferably 10 nm to 0.3 μm, and still more preferably 30 nm to 0.2 μm, from the characteristics as an optical interference layer.
<Polarizing plate protective film>
When the antireflection film of the present invention is used as a polarizing plate protective film, the thickness of the protective film is preferably 10 to 500 μm. In particular, 20 μm or more, more preferably 35 μm or more is preferable. Moreover, 150 micrometers or less, Furthermore 120 micrometers or less are preferable. Most preferably, it is 25 or more and 90 micrometers.
<Polarizing plate>
A polarizing plate using the antireflection film of the present invention will be described. The polarizing plate can be produced by a general method. The back surface side of the antireflective film of the present invention is subjected to alkali saponification treatment, and a completely saponified polyvinyl alcohol aqueous solution is used on at least one surface of a polarizer produced by immersing and stretching the treated antireflective film in an iodine solution. It is preferable to bond them together.

  The antireflection film may be used on the other surface, or another polarizing plate protective film may be used. With respect to the antireflection film of the present invention, the polarizing plate protective film used on the other surface has an in-plane retardation Ro of 590 nm, an optical compensation film having a phase difference of 20 to 70 nm and Rt of 70 to 400 nm. It is preferable to use a retardation film.

  These can be produced, for example, by the method of JP-A-2002-71957. Alternatively, it is preferable to use a polarizing plate protective film that also serves as an optical compensation film having an optically anisotropic layer formed by aligning a liquid crystal compound such as a discotic liquid crystal.

  For example, the optically anisotropic layer can be formed by the method described in JP-A-2003-98348. Alternatively, a non-oriented film having a retardation Ro of 590 nm of 0 to 5 nm and an Rt of -20 to +20 nm described in JP-A No. 2003-12859 is also preferably used.

  By using in combination with the antireflection film of the present invention, a polarizing plate having excellent flatness and a stable viewing angle expansion effect can be obtained.

  As a polarizing plate protective film used on the back side, as a commercially available cellulose ester film, KC8UX2MW, KC4UX, KC5UX, KC4UY, KC8UY, KC12UR, KC4UEW, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC4FR-1, KC4F-1, -2, KC8UE, KC4UE (manufactured by Konica Minolta Opto Co., Ltd.) and the like are preferably used.

A polarizer, which is a main component of a polarizing plate, is an element that allows only light of a plane of polarization in a certain direction to pass. A typical polarizer currently known is a polyvinyl alcohol-based polarizing film, which is polyvinyl alcohol. There are ones in which iodine is dyed on a system film and ones in which a dichroic dye is dyed, but it is not limited to this. For the polarizer, a polyvinyl alcohol aqueous solution is formed into a film and dyed by uniaxial stretching or dyed or uniaxially stretched and then preferably subjected to a durability treatment with a boron compound. A polarizer having a thickness of 5 to 30 μm, preferably 8 to 15 μm, is preferably used. On the surface of the polarizer, one surface of the antireflection film of the present invention is bonded to form a polarizing plate. It is preferably bonded with an aqueous adhesive mainly composed of completely saponified polyvinyl alcohol or the like.
<Image display device>
By incorporating a polarizing plate produced using the antireflection film of the present invention into a display device, various image display devices having excellent visibility can be produced.

  The antireflection film of the present invention is incorporated in the polarizing plate, and is a reflection type, transmission type, transflective liquid crystal display device or TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS. It is preferably used in liquid crystal display devices of various drive systems such as a type and an OCB type.

  The antireflection film of the present invention is also preferably used for various image display devices such as a plasma display, a field emission display, an organic EL display, an inorganic EL display, and electronic paper.

Example 1
<Preparation of antireflection films 1-10>
The base film 1 is produced as described below, and then the hard coat layer composition and the low refractive index layer composition are provided on the base film 1 as shown in the following and Table 1 to provide an antireflection layer. 10 and comparative antireflection films 1 and 2 were prepared.

<Base film 1; Production of cellulose ester film 1>
[Dope composition 1]
The following materials were sequentially put into a sealed container, the temperature in the container was raised from 20 ° C. to 80 ° C., and the mixture was stirred for 3 hours while maintaining the temperature at 80 ° C. to completely dissolve the cellulose ester. . The silicon oxide fine particles were added dispersed in a solution of a solvent to be added in advance and a small amount of cellulose ester.

  This dope was filtered using filter paper (Azumi filter paper No. 244, manufactured by Azumi Filter Paper Co., Ltd.) to obtain a dope composition 1.

Cellulose triacetate (acetyl group substitution degree 2.95) 100 parts by weight Trimethylolpropane tribenzoate 5 parts by weight Ethylphthalylethyl glycolate 5 parts by weight Fine particles of silicon oxide 0.2 parts by weight (Aerosil R972V, manufactured by Nippon Aerosil Co., Ltd.)
Tinuvin 109 (manufactured by Ciba Japan Co., Ltd.) 1 part by mass Tinuvin 171 (manufactured by Ciba Japan Co., Ltd.) 1 part by mass Methylene chloride 300 parts by mass Ethanol 40 parts by mass Butanol 5 parts by mass Next, the obtained dope composition 1 was obtained. The web was formed by casting on a support having a temperature of 35 ° C. made of a stainless steel endless belt through a casting die kept at a temperature of 35 ° C. Next, the web was dried on the support, and the web was peeled from the support with a peeling roll when the residual solvent amount of the web reached 80% by mass.

  The web after peeling is transported while being dried with 90 ° C drying air in a transport drying process using a plurality of rolls arranged on the top and bottom, and then grips both ends of the web with a tenter and then stretches in the width direction at a temperature of 130 ° C. The film was stretched to 1.1 times the previous size. After stretching with a tenter, the web was dried with a drying air at a temperature of 135 ° C. in a transport drying process using a plurality of rolls arranged vertically.

  After heat-treating for 15 minutes in an atmosphere with an atmosphere substitution rate of 15 (times / hour) in the drying process, the film was cooled to room temperature and wound up, with a width of 1.5 m, a thickness of 80 μm, a length of 4000 m, and a refractive index of 1.49 A long cellulose ester film 1 was produced. Further, the film was wound by applying a knurling process with a width of 1 cm and an average height of 10 μm at both ends.

  The draw ratio in the web conveyance direction immediately after peeling calculated from the rotational speed of the stainless steel band support and the operating speed of the tenter was 1.1 times.

The atmosphere substitution rate in the drying process is a unit time determined by the following formula when the atmosphere capacity of the drying process (heat treatment chamber) is V (m ³ ) and the fresh air flow rate is FA (m ³ / hr). This is the number of times the atmosphere in the heat treatment chamber is replaced with Fresh-air.

  “Fresh-air” means not a wind that is circulated and reused among the air blown into the heat treatment chamber, but means a fresh air that does not contain a volatilized solvent or plasticizer or has been removed.

Atmosphere replacement rate = FA / V (times / hour)
<Preparation of hard coat layer 1>
The following hard coat layer composition 1 filtered through a polypropylene filter having a pore size of 0.4 μm is applied to the surface of the cellulose ester film 1 using a micro gravure coater, dried at a temperature of 80 ° C., and then subjected to an ultraviolet lamp. The illuminance of the used irradiation part was 100 mW / cm ² , the irradiation amount was 0.2 J / cm ² , the coating layer was cured, and a hard coat layer having a dry film thickness of 10 μm was formed.

  Next, the following back coat layer composition 1 was applied to the surface of the cellulose ester film 1 opposite to the surface on which the hard coat layer 1 was applied with an extrusion coater so as to have a wet film thickness of 14 μm. After drying, a back coat layer 1 was provided.

[Hard Coat Layer Composition 1]
90 parts by mass of dipentaerythritol hexaacrylate (NK ester A-DPH, manufactured by Shin-Nakamura Chemical Co., Ltd.)
Pentaerythritol triacrylate 20 parts by mass Pentaerythritol tetraacrylate 60 parts by mass Urethane acrylate (trade name U-4HA manufactured by Shin-Nakamura Chemical Co., Ltd.) 10 parts by mass Irgacure 184 (manufactured by Ciba Japan Co., Ltd.) 10 parts by mass Silicone surfactant (Product name: KF-351A manufactured by Shin-Etsu Chemical Co., Ltd.) 3 parts by mass Propylene glycol monomethyl ether 10 parts by mass Methyl acetate 80 parts by mass Methyl ethyl ketone 100 parts by mass [Backcoat layer composition 1]
Acetone 54 parts by weight Methyl ethyl ketone 24 parts by weight Methanol 22 parts by weight Cellulose acetate propionate 0.6 parts by weight (acetyl group substitution degree 1.9, propionyl group substitution degree 0.8)
0.2 parts by mass of ultrafine silica 2% acetone dispersion (Aerosil 200V manufactured by Nippon Aerosil Co., Ltd.)
[Anti-glare hard coat layer composition AG1]
After mixing 10 parts by mass of fluorine-containing acrylic resin particles having an average particle size of 3.5 μm with 40 parts by mass of cyclohexanone and 60 parts by mass of methyl ethyl ketone, the mixture was stirred with an air disper for 20 minutes to obtain a particle dispersion. The following materials were mixed and stirred in this particle dispersion to prepare an antiglare hard coat layer composition 1.

90 parts by mass of dipentaerythritol hexaacrylate (NK ester A-DPH, manufactured by Shin-Nakamura Chemical Co., Ltd.)
Irgacure 184 (manufactured by Ciba Japan Co., Ltd.) 10 parts by mass Silicone surfactant (trade name: KF-351A, manufactured by Shin-Etsu Chemical Co., Ltd.) 3 parts by mass (production of a low refractive index layer)
The low refractive index layer coating composition 1 is applied to the surface of the hard coat layer prepared above with a microgravure coater so that the film thickness after drying is 92 nm, dried at a temperature of 80 ° C. for 1 minute, and then an ultraviolet lamp is used. The antireflective film 1 was produced by forming a low refractive index layer by curing under the conditions that the illuminance of the used irradiation part was 200 mW / cm ² and the irradiation amount was 0.35 J / cm ² .

<Preparation of hollow silica particle dispersion D-1>
A mixture of 100 g of silica sol having an average particle diameter of 5 nm and a SiO ₂ concentration of 20% by mass and 1900 g of pure water was heated to 80 ° C. The pH of this reaction mother liquor is 10.5. In the mother liquor, 9000 g of 0.98 mass% sodium silicate aqueous solution as SiO ₂ and 9000 g of 1.02 mass% sodium aluminate aqueous solution as Al ₂ O ₃ were simultaneously added. Added.

  Meanwhile, the temperature of the reaction solution was kept at 80 ° C. The pH of the reaction solution rose to 12.5 immediately after the addition and hardly changed thereafter.

After completion of the addition, the reaction solution was cooled to room temperature and washed with an ultrafiltration membrane to prepare a SiO ₂ · Al ₂ O ₃ core particle dispersion with a solid content concentration of 20% by mass (step a).

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

  Next, 1125 g of pure water is added to 500 g of the core particle dispersion liquid on which the first silica coating layer having a solid content concentration of 13 mass% is formed by washing with an ultrafiltration membrane, and concentrated hydrochloric acid (35.5%) is further added dropwise. The pH was adjusted to 1.0 and dealumination was performed.

Next, while adding 10 L of hydrochloric acid aqueous solution of pH 3 and 5 L of pure water, the aluminum salt dissolved in the ultrafiltration membrane was separated, and SiO _2. A dispersion of Al ₂ O ₃ porous particles was prepared (step c).

A mixture of 1500 g of the above porous particle dispersion, 500 g of pure water, 1750 g of ethanol, and 626 g of 28% ammonia water was heated to 35 ° C., and then 104 g of ethyl silicate (SiO ₂ 28 mass%) was added. The surface of the porous particles on which the silica coating layer was formed was coated with a hydrolyzed polycondensate of ethyl silicate to form a second silica coating layer.

  Next, a hollow silica particle dispersion D-1 having a solid content concentration of 20% by mass was prepared by replacing the solvent with ethanol using an ultrafiltration membrane.

The thickness of the first silica coating layer of the hollow silica particles was 3 nm, the average particle diameter was 45 nm, MO _X / SiO ₂ (molar ratio) was 0.0017, and the refractive index was 1.28. Here, the average particle diameter was measured by a dynamic light scattering method.

(Preparation of hollow silica particle dispersion D-2)
A mixture of 100 g of silica alumina sol having an average particle diameter of 25 nm and a SiO ₂ · Al ₂ O ₃ concentration of 20% by mass and 3900 g of pure water was heated to 98 ° C. While maintaining this temperature, 1750 g of a 1.5 mass% sodium silicate aqueous solution as SiO ₂ and 1750 g of a 0.5 mass% sodium aluminate aqueous solution as Al ₂ O ₃ were added, and SiO ₂ · Al ₂ O ₃ primary A particle dispersion was obtained. The pH of the reaction solution was 12.0 (step d).

Next, 3300 g of sodium sulfate having a concentration of 1.5% by mass was added, and 6300 g of 1.5% by mass of sodium silicate aqueous solution as SiO ₂ and 2100 g of 0.5% by mass of sodium aluminate aqueous solution as Al ₂ O ₃ were added. Thus, a composite oxide fine particle dispersion was obtained. The pH of the reaction solution was 12.0 (step e).

  Subsequently, 1125 g of pure water and 100 g of sodium sulfate having a concentration of 0.5% by mass were added to 500 g of the composite oxide fine particle dispersion having a solid concentration of 13% by washing with an ultrafiltration membrane, and concentrated hydrochloric acid (concentration 35). .5% by mass) was dropped to pH 1.0, and dealumination was performed.

  Subsequently, while adding 10 L of hydrochloric acid aqueous solution of pH 3 and 5 L of pure water, the aluminum salt dissolved in the ultrafiltration membrane was separated to obtain an aqueous dispersion of silica particles having a solid content concentration of 20% by mass (step f).

After heating a mixed liquid of 150 g of the above silica particle aqueous dispersion, 500 g of pure water, 1750 g of ethanol, and 626 g of 28% ammonia water to 35 ° C., 140 g of ethyl silicate (SiO ₂ 28 mass%) was added, A silica coating layer was formed and washed with an ultrafiltration membrane while adding 5 L of pure water to obtain an aqueous dispersion of silica particles having a silica coating layer with a solid content concentration of 20% by mass (step g).

  Next, ammonia water is added to the silica particle dispersion liquid on which the silica coating layer is formed to adjust the pH to 10.5, aged at 150 ° C. for 11 hours, cooled to room temperature, and ion exchange with a cation exchange resin. Then, ion exchange with an anion exchange resin was repeated, and then a hollow silica particle dispersion D-2 having a solid content concentration of 20% by mass was prepared by replacing the solvent with ethanol using an ultrafiltration membrane.

The thickness of the outer shell layer of the hollow silica particles was 10 nm, the average particle diameter was 55 nm, MO _X / SiO ₂ (molar ratio) was 0.0019, and the refractive index was 1.24. Here, the average particle diameter was measured by a dynamic light scattering method.

  The hollow silica particle dispersions D-3 and 4 used were prepared according to the method for preparing the hollow silica particle dispersion D-2.

Comparative Example 1
In the production of the antireflection film 1, the low refractive index layer composition was changed to “low refractive index layer coating material” described in Example 1 of JP-A No. 2007-182511 (prior art document 1), and a corona was formed on the hard coat layer surface. After discharging, it was applied and cured according to the curing method described in JP-A No. 2007-182511 to produce a comparative antireflection film 1.

Comparative Example 2
The coating liquid for (B) layer (hard coat layer) and (C) layer (low refractive index layer) described in Example 1 of JP-A-2008-26493 (prior art document 2) is prepared, and the cellulose ester film 1 is formed. After the corona discharge, it was applied and subjected to the curing treatment described in Example 1 of Japanese Patent Application Laid-Open No. 2008-26493, thereby producing a comparative antireflection film 2.

[Low refractive index layer composition 1]
(Cationically polymerizable compound)
Illustrative compound 1-A 6.3 parts by mass (photocation polymerization initiator)
Initiator 1: 0.9 part by weight of S-8 (silica particles)
Hollow silica particle dispersion D-3 28 parts by mass Colloidal silica particle dispersion 3 (Colo 3) 1.5 parts by mass (MEK-ST, average particle size 15 nm, manufactured by Nissan Chemical Industries, Ltd.)
(Additive)
10% propylene glycol monomethyl ether solution of silicone compound (FZ-2207, manufactured by Toray Dow Corning Co., Ltd.) 1.1 parts by mass (solvent)
Methyl isobutyl ketone 450 parts by weight Methyl ethyl ketone 200 parts by weight [Low refractive index layer composition 2]
(Cationically polymerizable compound)
Illustrative compound 1-A 6.3 parts by mass (photocation polymerization initiator)
Initiator 1: 0.9 part by weight of S-8 (silica particles)
Hollow silica particle dispersion D-2 28 parts by mass Colloidal silica particle dispersion 3 (Colo 3) 1.5 parts by mass (MEK-ST, average particle size 15 nm, manufactured by Nissan Chemical Industries, Ltd.)
(Additive)
10% propylene glycol monomethyl ether solution of silicone compound (FZ-2207, manufactured by Toray Dow Corning Co., Ltd.) 1.1 parts by mass (solvent)
Methyl isobutyl ketone 450 parts by weight Methyl ethyl ketone 200 parts by weight [Low refractive index layer composition 3]
(Cationically polymerizable compound)
Illustrative compound 1-A 6.3 parts by mass (photocation polymerization initiator)
Initiator 1: 0.9 part by weight of S-8 (silica particles)
Hollow silica particle dispersion D-1 28 parts by mass Colloidal silica particle dispersion 3 (Colo 3) 1.5 parts by mass (MEK-ST, average particle size 15 nm, manufactured by Nissan Chemical Industries, Ltd.)
(Additive)
10% propylene glycol monomethyl ether solution of silicone compound (FZ-2207, manufactured by Toray Dow Corning Co., Ltd.) 1.1 parts by mass (solvent)
Methyl isobutyl ketone 450 parts by weight Methyl ethyl ketone 200 parts by weight [Low refractive index layer composition 4]
(Cationically polymerizable compound)
Illustrative compound 1-A 6.3 parts by mass (photocation polymerization initiator)
Initiator 1: 0.9 part by weight of S-8 (silica particles)
Hollow silica particle dispersion D-3 28 parts by mass Colloidal silica particle dispersion 1 (Colo 1) 1.5 parts by mass (MEK-ST-L, average particle size 50 nm, manufactured by Nissan Chemical Industries, Ltd.)
(Additive)
10% propylene glycol monomethyl ether solution of silicone compound (FZ-2207, manufactured by Toray Dow Corning Co., Ltd.) 1.1 parts by mass (solvent)
Methyl isobutyl ketone 450 parts by weight Methyl ethyl ketone 200 parts by weight [Low refractive index layer composition 5]
(Cationically polymerizable compound)
Illustrative compound 1-A 6.3 parts by mass (photocation polymerization initiator)
Initiator 1: 0.9 part by weight of S-8 (silica particles)
Hollow silica particle dispersion D-2 28 parts by mass Colloidal silica particle dispersion 1 (Colo 1) 1.5 parts by mass (MEK-ST-L, average particle size 50 nm, manufactured by Nissan Chemical Industries, Ltd.)
(Additive)
10% propylene glycol monomethyl ether solution of silicone compound (FZ-2207, manufactured by Toray Dow Corning Co., Ltd.) 1.1 parts by mass (solvent)
Methyl isobutyl ketone 450 parts by weight Methyl ethyl ketone 200 parts by weight [Low refractive index layer composition 6]
(Cationically polymerizable compound)
Illustrative compound 1-A 6.3 parts by mass (photocation polymerization initiator)
Initiator 1: 0.9 part by weight of S-8 (silica particles)
Hollow silica particle dispersion D-1 28 parts by mass Colloidal silica particle dispersion 1 (Colo 1) 1.5 parts by mass (MEK-ST-L, average particle size 50 nm, manufactured by Nissan Chemical Industries, Ltd.)
(Additive)
10% propylene glycol monomethyl ether solution of silicone compound (FZ-2207, manufactured by Toray Dow Corning Co., Ltd.) 1.1 parts by mass (solvent)
Methyl isobutyl ketone 450 parts by weight Methyl ethyl ketone 200 parts by weight [Low refractive index layer composition 7]
(Cationically polymerizable compound)
Illustrative compound 1-A 6.3 parts by mass (photocation polymerization initiator)
Initiator 1: 0.9 part by weight of S-8 (silica particles)
Hollow silica particle dispersion D-4 28 parts by mass Colloidal silica particle dispersion 2 (Colo 2) 1.5 parts by mass (IPA-ST-ZL, average particle size 100 nm, manufactured by Nissan Chemical Industries, Ltd.)
(Additive)
10% propylene glycol monomethyl ether solution of silicone compound (FZ-2207, manufactured by Toray Dow Corning Co., Ltd.) 1.1 parts by mass (solvent)
Methyl isobutyl ketone 450 parts by weight Methyl ethyl ketone 200 parts by weight [Low refractive index layer composition 8]
(Cationically polymerizable compound)
Illustrative compound 1-A 6.3 parts by mass (photocation polymerization initiator)
Initiator 1: 0.9 part by weight of S-8 (silica particles)
Hollow silica particle dispersion D-2 28 parts by mass Colloidal silica particle dispersion 2 (Colo 2) 1.5 parts by mass (IPA-ST-ZL, average particle size 100 nm, manufactured by Nissan Chemical Industries, Ltd.)
(Additive)
10% propylene glycol monomethyl ether solution of silicone compound (FZ-2207, manufactured by Toray Dow Corning Co., Ltd.) 1.1 parts by mass (solvent)
Methyl isobutyl ketone 450 parts by weight Methyl ethyl ketone 200 parts by weight [Low refractive index layer composition 9]
(Cationically polymerizable compound)
Illustrative compound 1-A 6.3 parts by mass (photocation polymerization initiator)
Initiator 1: 0.9 part by weight of S-8 (silica particles)
Hollow silica particle dispersion D-1 28 parts by mass Colloidal silica particle dispersion 2 (Colo 2) 1.5 parts by mass (IPA-ST-ZL, average particle size 100 nm, manufactured by Nissan Chemical Industries, Ltd.)
(Additive)
10% propylene glycol monomethyl ether solution of silicone compound (FZ-2207, manufactured by Toray Dow Corning Co., Ltd.) 1.1 parts by mass (solvent)
Methyl isobutyl ketone 450 parts by weight Methyl ethyl ketone 200 parts by weight << Evaluation >>
The prepared antireflection films 1 to 10 and comparative antireflection films 1 and 2 were evaluated by the following methods. The obtained results are shown in Table 1.

(Refractive index)
The refractive index of the low refractive index layer was determined from the measurement result of the spectral reflectance of the spectrophotometer for the sample in which the low refractive index layer was coated on the hard coat film prepared above.

  The spectrophotometer uses U-4000 type (manufactured by Hitachi, Ltd.), and after roughening the back side of the measurement side of the sample, light absorption treatment is performed with black spray to prevent reflection of light on the back side. In the atmosphere of 23 ° C. and 55% RH, the reflectance in the visible light region (400 to 700 nm) was measured under the condition of regular reflection at 5 degrees.

(Reflectance measurement)
Using a spectrophotometer V-550 (manufactured by JASCO), the specular reflectance% in the wavelength range of 380 to 780 nm was measured at an incident angle of 5 °. In the evaluation of the reflectance, the minimum reflectance in the wavelength region of 450 to 650 nm was used. In addition, after roughening the back surface of the measurement surface of the sample, light absorption treatment was performed with black spray to prevent reflection of light on the back surface, and reflectance measurement was performed.

(Abrasion resistance)
In an atmosphere of 23 ° C. and 55% RH, a steel wool having a product number # 0000 made by Nippon Steel Wool Co., Ltd. with a load of 1000 g / cm ² is placed on the surface of the low refractive index layer of the antireflection film, and 20 reciprocations are performed. The number of scratches generated per 1 cm width was measured.

  The number of scratches is preferably 5 / cm width or less, more preferably 1 / cm width or less. As the apparatus for reciprocating the steel wool, a Shinto Kagaku Co., Ltd. friction and wear tester (Tribo Station TYPE: 32, moving speed 4000 mm / min.) Was used.

(Light resistance (including adhesion) test)
On the surface of the antireflection film, using a super xenon weather meter (SX120, manufactured by Suga Test Instruments Co., Ltd.), the light amount is 100 W / m ² ; 300 to 400 nm, the black panel temperature is 50 ° C., the humidity is 65%, and the test time is 2000 hours. The UV irradiation test was conducted under the conditions of

  Thereafter, the scratch resistance was evaluated by the above method, and a cross-cut tape peeling test was performed in an atmosphere of 23 ° C. and 55% RH in accordance with the following JIS K 5600-5-6 to evaluate the adhesion.

  Using a cutter, put 11 scratches of 1 mm in length and width on the surface of the sample to make 100 squares of 1 mm square (cross cut), and press the tape using cello tape (registered trademark) manufactured by Nichiban Co., Ltd. Then, peeling was repeated three times at the same place. Then, the sample surface after tape peeling was observed visually, and the following references | standards evaluated.

Evaluation criteria for adhesion ○: Affected part is 5% or less △: Affected part is over 5% but 30% or less ×: Affected part is over 30% (pencil hardness)
The antireflection film was conditioned for 2 hours in an environment of 25 ° C. and 60% RH, and then a scratch test was performed according to JIS K5600-5-4.

  Using a 1 kg weight, scratching with a pencil of each hardness was performed five times while changing the location, and the hardness until one scratch was found was measured. In addition, the term “scratches” here refers to tearing of the coating film, scratches and dents. Higher values indicate higher hardness, preferably 3H or higher. Furthermore, the state of the scratched mark was evaluated according to the following criteria. If practically Δ or more, there is no problem and ○ or more is preferable.

Pencil Hardness Evaluation Criteria ◎: Scratch marks are not recognized at all ○: Slight discoloration is observed in one of 5 scratches △: Slight discoloration is observed in 2 or more after 5 scratches ×: Scratch marks are clear appear

  As is clear from the results in Table 1, the low refractive index layer contains two or more types of silica particles having different average particle sizes, at least one of which is a colloidal silica particle having an average particle size R1 ′, and at least one of the average particles In the case of a combination of hollow silica particles having a diameter of R2 ′, it has excellent reflectance and scratch resistance, and excellent scratch resistance and adhesion even after a light resistance test assuming use under severe conditions for a long period of time. It can be seen that it has a high pencil hardness and is not easily scratched.

  Particularly, the antireflection film in which the ratio R1 ′ / R2 ′ of the average particle diameter R1 ′ of the colloidal silica particles and the average particle diameter R2 ′ of the hollow silica particles is set to 0.10 or more and less than 1.20 is R1 ′. / R2 ′ is less likely to be scratched than an antireflection film set outside the range of 0.10 or more and less than 1.20, and the antireflection film set to 0.15 or more and less than 0.60 has no scratch mark. It can be seen that it shows no particularly good pencil hardness.

Example 2
In the same manner as in Example 1, the base film, the hard coat layer composition, and the low refractive index layer composition were changed as shown below and Table 2 to prepare antireflection films 11 and 12.

<Production of Base Film 2 = Production of Cellulose Ester Resin / Acrylic Resin Film 1>
(Dope solution composition 2)
Acrylic resin Dianal BR80 (Mitsubishi Rayon Co., Ltd.) 70 parts by mass (MW95000)
CAP482-20 (acyl group total substitution degree 2.75, acetyl group substitution degree 0.19, propionyl group substitution degree 2.56, Mw = 200000 manufactured by Eastman Chemical Co., Ltd.)
30 parts by weight Tinuvin 109 (manufactured by Ciba Japan) 1 part by weight Tinuvin 171 (manufactured by Ciba Japan) 1 part by weight Methylene chloride 300 parts by weight Ethanol 40 parts by weight Butanol 5 parts by weight While heating the above composition, It fully melt | dissolved and the dope liquid was produced. In addition, CAP is a cellulose acetate propionate resin.

(Film formation of cellulose ester resin / acrylic resin film 1)
The produced dope solution was uniformly cast on a stainless steel band support at a temperature of 22 ° C. and a width of 2 m using a belt casting apparatus. With the stainless steel band support, the solvent was evaporated until the amount of residual solvent reached 100%, and peeling was performed from the stainless steel band support with a peeling tension of 162 N / m.

  The peeled acrylic resin web was evaporated at 35 ° C., slit to 1.6 m width, and then dried at a drying temperature of 135 ° C. while being stretched 1.1 times in the width direction by a tenter. At this time, the residual solvent amount when starting stretching with a tenter was 10%.

  After stretching with a tenter and relaxing at 130 ° C for 5 minutes, drying was completed while transporting the drying zone at 120 ° C and 130 ° C with a number of rolls, slitting to a width of 1.5 m, and 10 mm wide at both ends of the film. A knurling process having a thickness of 10 μm was applied to wind up, and a cellulose ester resin / acrylic resin film 1 having a film thickness of 80 μm, a length of 4000 m, and a refractive index of 1.50 was obtained.

  The draw ratio in the MD direction calculated from the rotational speed of the stainless steel band support and the operating speed of the tenter was 1.1 times.

<Preparation of base film 3>
A base film 3 (acrylic particle-containing cellulose ester resin / acrylic resin film 1) was prepared in the same manner except that the base film 2 was changed to the following dope composition 2 in the preparation of the base film 2.

(Preparation of acrylic particles)
A reactor with a reflux condenser with an internal volume of 60 liters was charged with 38.2 liters of ion-exchanged water and 111.6 g of sodium dioctylsulfosuccinate, and the temperature was raised to 75 ° C. in a nitrogen atmosphere while stirring at 250 rpm. The effect of oxygen was virtually eliminated. 0.36 g of APS was added, and after stirring for 5 minutes, a monomer mixture consisting of MMA 1657 g, BA 21.6 g, and ALMA 1.68 g was added all at once, and after the exothermic peak was detected, the mixture was held for another 20 minutes to polymerize the innermost hard layer. Completed. Next, 3.48 g of APS was added, and after stirring for 5 minutes, a monomer mixture consisting of BA 8105 g, PEGDA (200) 31.9 g, and ALMA 264.0 g was continuously added over 120 minutes. Hold for a minute to complete the polymerization of the soft layer.

  Next, 1.32 g of APS was added, and after stirring for 5 minutes, a monomer mixture composed of 2106 g of MMA and 201.6 g of BA was continuously added over 20 minutes. The polymerization of was completed.

  Next, 1.32 g of APS was added, and after 5 minutes, a monomer mixture consisting of 3148 g of MMA, 201.6 g of BA, and 10.1 g of n-OM was continuously added over 20 minutes, and the mixture was held for another 20 minutes after the addition was completed. Next, the temperature was raised to 95 ° C. and held for 60 minutes to complete the polymerization of the outermost hard layer 2.

  A small amount of the polymer latex thus obtained was collected, and the flat particle size was determined by the absorbance method, which was 0.10 μm. The remaining latex was poured into a 3% by mass sodium sulfate warm aqueous solution, salted out and coagulated, and then dried after repeated dehydration and washing to obtain acrylic particles having a three-layer structure.

  The above abbreviations are the following materials.

MMA; methyl methacrylate MA; methyl acrylate BA; n-butyl acrylate ALMA; allyl methacrylate PEGDA; polyethylene glycol diacrylate (molecular weight 200)
n-OM; n-octyl mercaptan APS; ammonium persulfate (production of acrylic particle-containing cellulose ester resin / acrylic resin film 1)
(Dope solution composition 3)
Dianar BR80 (manufactured by Mitsubishi Rayon Co., Ltd.) 70 parts by mass CAP482-20 30 parts by mass The prepared acrylic particles 20 parts by mass Tinuvin 109 (manufactured by Ciba Japan Co., Ltd.) 1 part by mass Tinuvin 171 (manufactured by Ciba Japan Co., Ltd.) ) 1 part by mass Methylene chloride 300 parts by mass Ethanol 40 parts by mass Butanol 5 parts by mass The above composition was sufficiently dissolved while heating to prepare a dope solution.

[Antistatic hard coat layer composition ANS1]
90 parts by mass of dipentaerythritol hexaacrylate (NK ester A-DPH, manufactured by Shin-Nakamura Chemical Co., Ltd.)
Pentaerythritol triacrylate 20 parts by mass Pentaerythritol tetraacrylate 60 parts by mass Urethane acrylate 10 parts by mass (trade name U-4HA manufactured by Shin-Nakamura Chemical Co., Ltd.)
90 parts by mass of methanol-dispersed phosphorus-doped tin oxide sol (solid content 50%, manufactured by Nissan Chemical Industries, Ltd., trade name Celnax CX-S501M)
Irgacure 184 (Ciba Japan Co., Ltd.) 10 parts by mass Silicone surfactant 3 parts by mass (Shin-Etsu Chemical Co., Ltd., trade name: KF-351A)
Propylene glycol monomethyl ether 50 parts by weight Methanol 20 parts by weight Methyl ethyl ketone 100 parts by weight << Evaluation >>
The antireflection film 2 produced in Example 1 and the produced antireflection films 11 and 12 were evaluated by the method described in Example 1. Furthermore, each was cut into A4 size, the low refractive index layer was used as the surface, and it was stored for 700 hours in a high-temperature and high-humidity thermo at a temperature of 80 ° C. and a humidity of 90% RH to prepare a wet heat treatment sample.

  Subsequently, the antireflection film subjected to the wet heat treatment was conditioned for 24 hours under the conditions of a temperature of 23 ° C. and a relative humidity of 55%, and the pencil hardness was evaluated by the method described in Example 1.

  The results obtained from the above are shown in Table 3. In addition, the base film shown in Table 2 was shown with the following abbreviations.

Base film 1: cellulose ester film 1
Base film 2: Cellulose ester resin / acrylic resin film 1
Base film 3: Cellulose ester resin / acrylic resin film 1 containing acrylic particles

  As is clear from the results in Table 3 above, even when the base film is a cellulose ester resin / acrylic resin film or an acrylic particle-containing cellulose ester resin / acrylic resin film, it is excellent as in the case of the cellulose ester film. It shows low reflection and scratch resistance, and also has good light resistance.

  Further, in evaluation after severe wet heat treatment, the base film is a film made of cellulose ester resin / acrylic resin rather than cellulose ester film, or a film composed of cellulose ester resin / acrylic resin and containing acrylic particles. It can be seen that the method is particularly excellent in pencil hardness.

Example 3
In the production of the antireflection film 1 of Example 1, an antireflection film 13 was produced in the same manner except that the cellulose ester film 1 as a base film was changed to the cellulose ester film 2 described below. About the produced anti-reflective film 13, as a result of performing processing and evaluation similarly to Example 1, the performance comparable as the anti-reflective film 1 of Example 1 was obtained.

<Base film 4; Production of cellulose ester film 2>
(Synthesis of cellulose ester C1)
With reference to Example B of JP-T-6-501040, the amount of propionic acid and acetic acid was adjusted to synthesize cellulose ester C1 with the acetyl group substitution degree and propionyl group substitution degree adjusted as follows. .

C1: acetyl group substitution degree 1.9, propionyl group substitution degree 0.7, total acyl group substitution degree 2.60
The substitution degree of the obtained cellulose ester was calculated based on ASTM-D817-96. The weight average molecular weight of the cellulose ester C1 was 130,000 as a result of measurement using the high performance liquid chromatography.

(Preparation of cellulose ester film 2)
A cellulose ester film 2 was produced by melt casting with the following composition.

<Cellulose ester film 2 composition>
Cellulose ester: C1 94 parts by mass Plasticizer: Glycerin tribenzoate 5 parts by mass Irganox 1010 (manufactured by Ciba Japan) 0.5 part by mass Irgafos P-EPG (manufactured by Ciba Japan) 0.3 part by mass HP- 136 (manufactured by Ciba Japan Co., Ltd.) 0.2 parts by mass The above cellulose ester was dried under reduced pressure at 70 ° C. for 3 hours and cooled to room temperature, and then each additive was mixed.

  The above mixture was formed into a film by a manufacturing apparatus using an elastic touch roll. In a nitrogen atmosphere, it was melted at 240 ° C., extruded from the casting die onto the first cooling roll, and molded by pressing the film between the first cooling roll and the touch roll. Further, silica particles (manufactured by Nippon Aerosil Co., Ltd.) were added as a slip agent from the hopper opening in the middle of the extruder so as to be 0.1 part by mass.

  The heat bolt was adjusted so that the gap width of the casting die was 0.5 mm within 30 mm from the end in the width direction of the film and 1 mm at other locations. As a touch roll, 80 degreeC water was poured as cooling water in the inside.

  The circumference of the first cooling roller from the position P1 where the resin extruded from the casting die contacts the first cooling roll to the position P2 at the upstream end in the first cooling roll rotation direction of the nip between the first cooling roll and the touch roll. The length L along the surface was set to 20 mm.

  Thereafter, the touch roll was separated from the first cooling roll, and the temperature T of the melted part immediately before being sandwiched in the nip between the first cooling roll and the touch roll was measured. The temperature T of the melted part immediately before being squeezed by the nip between the first cooling roll and the touch roll is a thermometer (HA-200E manufactured by Anritsu Keiki Co., Ltd.) at a position 1 mm upstream from the nip upstream end P2. It was measured by. As a result of the measurement, the temperature T was 141 ° C. The linear pressure of the touch roll against the first cooling roll was 14.7 N / cm.

  Furthermore, after being introduced into a tenter and stretched 1.3 times at 160 ° C in the width direction, it was cooled to 30 ° C while relaxing 3% in the width direction, then released from the clip, the clip gripping part was cut off, and both ends of the film Was subjected to a knurling process having a width of 20 mm and a height of 25 μm, and wound on a winding core with a winding tension of 220 N / m and a taper of 40%.

  The winding core had an inner diameter of 152 mm, an outer diameter of 165 to 180 mm, and a length of 1550 mm. A prepreg resin obtained by impregnating glass fibers and carbon fibers with an epoxy resin was used as the core material for the core. The surface of the core was coated with an epoxy conductive resin, the surface was polished, and the surface roughness Ra was finished to 0.3 μm. In addition, the film thickness was 40 micrometers, the winding length was 3500 m, and the cellulose-ester film 2 of refractive index 1.49 was produced.

Example 4
Using the antireflection films 1 to 12 and the comparative films 1 and 2 prepared in Examples 1 and 2, polarizing plates were prepared as follows, and these polarizing plates were incorporated into a liquid crystal display panel (image display device). The visibility was evaluated.

  According to the following method, Konica Minolta Tack KC8UCR5 (manufactured by Konica Minolta Opto Co., Ltd.), which is a cellulose ester optical compensation film, is used for polarizing plate protection for each of the antireflection films 1 to 12 and the comparative films 1 and 2 of Example 1 Polarizing plates 101 to 112 and comparisons 101 and 102 were produced as films.

(A) Production of Polarizer A material obtained by impregnating 10 parts by mass of glycerol and 170 parts by mass of water into 100 parts by mass of polyvinyl alcohol (hereinafter abbreviated as PVA) having a saponification degree of 99.95 mol% and a polymerization degree of 2400. After melt-kneading and defoaming, it was melt-extruded from a T-die onto a metal roll to form a film. Then, it dried and heat-processed and obtained the PVA film. The obtained PVA film had an average thickness of 40 μm, a moisture content of 4.4%, and a film width of 3 m.

  Next, the obtained PVA film was continuously processed in the order of preliminary swelling, dyeing, uniaxial stretching by a wet method, fixing treatment, drying, and heat treatment to produce a polarizer. That is, the PVA film was pre-swelled by immersing in water at a temperature of 30 ° C. for 30 seconds, and immersed in an aqueous solution having an iodine concentration of 0.4 g / liter and a potassium iodide concentration of 40 g / liter at a temperature of 35 ° C. for 3 minutes. Subsequently, the film was uniaxially stretched 6 times in a 50% aqueous solution with a boric acid concentration of 4% under the condition that the tension applied to the film was 700 N / m, and the potassium iodide concentration was 40 g / liter and the boric acid concentration was 40 g / liter. Then, it was immersed in an aqueous solution having a zinc chloride concentration of 10 g / liter and a temperature of 30 ° C. for 5 minutes for fixing. Thereafter, the PVA film was taken out, dried with hot air at a temperature of 40 ° C., and further heat-treated at a temperature of 100 ° C. for 5 minutes. The obtained polarizer had an average thickness of 13 μm, a polarization performance of 43.0% transmittance, a polarization degree of 99.5%, and a dichroic ratio of 40.1.

(B) Production of Polarizing Plate Next, in accordance with the following steps 1 to 5, a polarizer and a protective film for polarizing plate are bonded to each other and polarized light corresponding to the antireflection films 1 to 12 of Example 1 and Comparative Examples 1 and 2. Plates 101 to 112 and comparative examples 101 and 102 were produced.

  Step 1: The optical compensation film and the antireflection film were immersed in a 2 mol / L sodium hydroxide solution at a temperature of 60 ° C. for 90 seconds, then washed with water and dried. A surface of each antireflection film provided with a low refractive index layer was previously protected with a peelable protective film (PET).

  Similarly, the above-described optical compensation film was immersed in a 2 mol / L sodium hydroxide solution at a temperature of 60 ° C. for 90 seconds, then washed with water and dried.

  Process 2: The above-mentioned polarizer was immersed in a storage tank of a polyvinyl alcohol adhesive solution having a solid content of 2% by mass for 1 to 2 seconds.

  Step 3: Excess adhesive adhered to the polarizer in Step 2 was lightly removed, and this polarizer was sandwiched between the optical compensation film subjected to alkali treatment in Step 1 and an antireflection film, and laminated.

Process 4: The laminate was bonded at a speed of about 2 m / min at a pressure of ^{20 to} 30 N / cm ² with two rotating rollers. At this time, it was carried out with care to prevent bubbles from entering.

  Step 5: The sample prepared in Step 4 was dried in a dryer at a temperature of 80 ° C. for 2 minutes to prepare polarizing plates 101 to 112 and comparative polarizing plates 101 and 102.

  Next, the polarizing plate on the outermost surface of a commercially available liquid crystal display panel (VA type) was carefully peeled off, and the previously prepared polarizing plate with the polarization direction matched was attached thereto.

  The liquid crystal panel thus obtained was placed on a desk 80 cm high from the floor, and a daylight direct fluorescent lamp (FLR40S • D / MX Matsushita Electric Industrial Co., Ltd.) was placed on the ceiling 3 m high from the floor. (Manufactured) One set of 40W × 2 was placed in 10 sets at 1.5 m intervals.

  In this case, when the evaluator is in front of the display surface of the liquid crystal display panel, the fluorescent lamp is arranged so that the fluorescent lamp comes to the ceiling portion from the evaluator's overhead to the rear. Each liquid crystal panel was tilted by 25 ° from the vertical direction with respect to the desk, and the visibility of the screen (visibility) was evaluated by dividing it into the following ranks so that a fluorescent lamp was reflected.

  The results are shown in Table 7.

A: I don't care about the reflection of the nearest fluorescent lamp, and I can clearly read characters with a font size of 8 or less. B: The reflection of a nearby fluorescent lamp is a little anxious, but I don't care about the distance. Can manage to read characters with a font size of 8 or less C: It is difficult to read characters with a font size of 8 or less. I'm curious, the part of the reflection can not read characters with a font size of 8 or less

  As is clear from the results in Table 4, all the liquid crystal panels using the polarizing plate of the present invention were the evaluation results of A, and the visibility was better.

Claims (5)

An antireflection layer containing (A) at least two types of silica particles having different average particle diameters, (B) a cationically polymerizable compound represented by the following general formula (1), and (C) a photocationic polymerization initiator a use composition, (a) of the at least two kinds of silica particles having an average particle diameter is different, at least one hollow silica particles, at least one is Ri Ah with colloidal silica particles, the average of the colloidal silica particles the ratio of the the R1 '/ R2', the composition for an antireflection layer, characterized in der Rukoto 0.15 to 0.60 'average particle diameter R2 of the hollow silica particles' diameter R1.

Here, R ¹ represents a group capable of cationic polymerization having 1 to 10 carbon atoms. R ² represents a group selected from a methyl group, an ethyl group, and a propyl group. n represents 0, 1, or 2. 2. The composition for an antireflection layer according to claim 1, wherein R ^{1 of the} compound represented by the general formula (1) is a group having an epoxy structure or an oxetane structure.   An antireflection film comprising a layer obtained by curing the composition according to claim 1. A polarizing plate characterized by using the antireflection film of claim 3. An image display device comprising the use of a polarizing plate according to claim 4.