JP2011075938A - Antireflection film, polarizing plate, and image display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection film which has low reflectance, and superior antireflection function of reducing the coloring of reflected light and an antistatic function, and further is superior in scratch resistance, adhesion and productivity. <P>SOLUTION: The antireflection film has at least a layer (A) and a layer (B) in this order on the surface of a transparent support. The layer (A) is a layer formed from a composition containing: (a1) a fluorine-containing polymerizable compound expressed by general formula (1) wherein the content of fluorine is ≥35 mass% and the calculated value of all of inter-bridge molecular weights is lower than 500; and (a2) a conductive material. The layer (B) is a low refractive index layer having a refractive index lower than that of the layer (A), and the surface resistivity of the antireflection film is ≤1×10<SP>12</SP>Ω/SQUARE. The general formula (1): Rfä-(L)<SB>m</SB>-Y}<SB>n</SB>; wherein, Rf denotes an n-valent group including a carbon atom and a fluorine atom; n denotes the integer of ≥3; L denotes a bivalent linking group; m denotes 0 or 1; and Y denotes a polymerizable group. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an antireflection film, a polarizing plate using the antireflection film, and an image display device using the antireflection film or the polarizing plate on the outermost surface of a display.

  In general, an antireflection film is used in an image display device such as a cathode ray tube display (CRT), a plasma display (PDP), an electroluminescence display (ELD), and a liquid crystal display (LCD). In order to prevent reflection of light, it is arranged on the outermost surface of the display so as to reduce the reflectance by using the principle of optical interference.

  Such an antireflection film is produced by forming a low refractive index layer having an appropriate thickness on the outermost surface, and optionally a high refractive index layer, a middle refractive index layer, a hard coat layer, etc. between the support and the support. it can. In order to realize a low reflectance, a material having a refractive index as low as possible is desired for the low refractive index layer. Further, since the antireflection film is used on the outermost surface, it is expected to have a function as a protective film of the image display device (for example, dirt and dust are hardly attached and scratch resistance is strong). In order to realize high scratch resistance in a thin film having a thickness of around 100 nm, the strength of the coating itself and the adhesion to the lower layer are required.

When a conventional antireflection film is used on the display surface, there is a problem that dust in the environment tends to adhere, and an improved technique has been demanded.
As a technique for imparting dust resistance, it has been conventionally proposed to add a cationic or anionic material. However, when such materials are used, there are problems such as separation in the coating solution for film formation, unevenness during coating of the coating solution, and deterioration of the scratch resistance of the film. Was.

  Patent Document 1 describes providing a so-called antistatic layer containing conductive particles. This method has a problem that it is necessary to newly provide a layer in addition to the refractive index adjustment layer (high refractive index layer, low refractive index layer, etc.), and the load of equipment and time during production is large. . In addition, the conductive particles for antistatic that are generally used in the past have many particles having a refractive index of about 1.6 to 2.2, and the refractive index of the antistatic layer containing these particles is increased. End up. If the refractive index of the antistatic layer is high, there are problems such as unintentional interference unevenness due to the difference in refractive index between adjacent layers and an increase in the color of the reflected color, and improvements have been desired.

  Patent Document 2 discloses, as a method for reducing the coloring of the reflected color, bringing the refractive indexes of the antistatic layer and the hard coat layer serving as a base thereof close to each other. However, in the technique described in this document, an antistatic layer made of a thermosetting resin is laminated on a hard coat layer made of a photocurable acrylate resin, and in order to provide adhesion between layers, Prior to forming the antistatic layer, the surface of the hard coat layer had to be subjected to an alkali treatment. Applying an alkali treatment between the formation of the hard coat layer and the antistatic layer increases the number of manufacturing processes and further facilitates the entry of foreign substances, resulting in a decrease in productivity and a decrease in yield due to the occurrence of defects. There was a problem of inviting.

  As a method for forming a low refractive index layer containing conductive particles, Patent Document 3 and Patent Document 4 disclose that particles having a silica particle surface coated with a conductive metal oxide are used for the low refractive index layer. However, the particles have a problem that the production process is complicated and expensive.

JP 2005-196122 A JP 2008-3122 A JP 2005-119909 A JP 2007-114772 A

  The present invention provides an antireflection film that has an excellent antireflection function and antistatic function with low reflectivity and reduced coloration of reflected light, and also has excellent scratch resistance, adhesion, and productivity. The purpose is to do.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the following configuration can solve the problems and achieve the object, and the present invention has been completed.

1.
An antireflection film having at least a layer (A) and a layer (B) in this order on a transparent support,
The layer (A) is (a1) represented by the following general formula (1), contains 35% by mass or more of fluorine, and all fluorine-containing polymerizable compounds having a calculated value of molecular weight between crosslinks smaller than 500; a2) a conductive material and a layer formed from a composition containing
The layer (B) is a low refractive index layer having a lower refractive index than the layer (A),
An antireflection film having a surface resistivity of 1 × 10 ¹² Ω / □ or less.
General formula (1): Rf {-(L) _m- Y} _n
(In the formula, Rf represents an n-valent group containing a carbon atom and a fluorine atom. N represents an integer of 3 or more. L represents a divalent linking group, m represents 0 or 1. Y represents polymerization. Represents a sex group.)
2.
2. The antireflection film as described in 1 above, further comprising a hard coat layer in contact with the layer (A) between the transparent support and the layer (A).
3.
Refractive index (n _A) and the refractive index of the hard coat layer of the layer (A) (n _HC) is, antireflection film as described in 2, wherein satisfies the following equation (1).
Formula (1): 0 ≦ | (n _A −n _HC ) / n _HC | ≦ 0.05
4).
4. The antireflection film as described in any one of 1 to 3 above, wherein the refractive index of the layer (B) is 1.33 to 1.40 at a wavelength of 550 nm.
5).
5. The antireflection film as described in any one of 1 to 4 above, wherein the optical thickness (nd) of the layer (B) is 100 nm to 200 nm.
6).
The conductive material is tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), phosphorus-doped tin oxide (PTO), zinc antimonate, indium-doped zinc oxide (IZO), 6. The antireflection according to any one of 1 to 5, which is at least one metal oxide selected from the group consisting of zinc oxide, ruthenium oxide, rhenium oxide, silver oxide, nickel oxide and copper oxide. the film.
7).
The antireflection film as described in any one of 1 to 6 above, wherein the (a1) fluorine-containing polymerizable compound contains 40% by mass or more of fluorine.
8).
8. The antireflection film as described in any one of 1 to 7 above, wherein the calculated value of all cross-linking molecular weights of the (a1) fluorine-containing polymerizable compound is larger than 50 and smaller than 300.
9.
The layer (A) contains the conductive material (a2) in an amount of 40% by mass to 80% by mass with respect to the total solid content of the layer (A). Antireflection film.
10.
10. The antireflection film as described in any one of 1 to 9 above, wherein the refractive index of the layer (A) is 1.50 to 1.60 at a wavelength of 550 nm.
11.
11. The antireflection film as described in any one of 1 to 10 above, wherein the optical thickness (nd) of the layer (A) is 200 nm to 300 nm at a wavelength of 550 nm.
12
A polarizing plate having a polarizing film and two protective films for protecting both surfaces of the polarizing film, wherein at least one of the protective films is the antireflection film according to any one of 1 to 11 above. A polarizing plate.
13.
13. An image display device comprising the antireflection film according to any one of 1 to 11 or the polarizing plate according to 12 above on an outermost surface of a display.

  According to the present invention, an antireflection film having an excellent antireflection function and antistatic function with low reflectance and reduced coloration of reflected light, and further excellent in scratch resistance, adhesion, and productivity. Can be provided.

  Hereinafter, the present invention will be described in detail. However, the present invention is not limited by the following description. In the present specification, when a numerical value represents a physical property value, a characteristic value, etc., the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more and (numerical value 2) or less” . In the present specification, the description “(meth) acrylate” means “at least one of acrylate and methacrylate”. The same applies to “(meth) acrylic acid” and the like.

The antireflection film of the present invention is an antireflection film having at least a layer (A) and a layer (B) in this order on a transparent support,
The layer (A) is (a1) represented by the following general formula (1), contains 35% by mass or more of fluorine, and all fluorine-containing polymerizable compounds having a calculated value of molecular weight between crosslinks smaller than 500; a2) a conductive material and a layer formed from a composition containing
The layer (B) is a low refractive index layer having a lower refractive index than the layer (A),
The surface resistivity of the antireflection film is 1 × 10 ¹² Ω / □ or less.
General formula (1): Rf {-(L) _m- Y} _n
(In the formula, Rf represents an n-valent group containing a carbon atom and a fluorine atom. N represents an integer of 3 or more. L represents a divalent linking group, m represents 0 or 1. Y represents polymerization. Represents a sex group.)

  Hereinafter, the antireflection film of the present invention will be described.

[Layer (A)]
The layer (A) in the antireflection film of the present invention is disposed between the transparent support and the layer (B). The layer (A) is (a1) represented by the following general formula (1), contains 35% by mass or more of fluorine, and has a calculated value of all cross-linking molecular weights less than 500, and (a2 ) A conductive material and a layer formed from a composition containing the conductive material.
General formula (1): Rf {-(L) _m- Y} _n
(In the formula, Rf represents an n-valent group containing a carbon atom and a fluorine atom. N represents an integer of 3 or more. L represents a divalent linking group, m represents 0 or 1. Y represents polymerization. Represents a sex group.)

(Fluorine-containing polymerizable compound)
(A1) contained in the composition for forming the layer (A), represented by the general formula (1), containing 35% by mass or more of fluorine, and the calculated values of all cross-linking molecular weights are smaller than 500 The fluorine-containing polymerizable compound (hereinafter also referred to as (a1) fluorine-containing polymerizable compound) will be described.

In the general formula (1), Rf represents a “fluorine-containing core part”, which contains at least a carbon atom and a fluorine atom, and may contain an oxygen atom and / or a hydrogen atom. Represents a hydrocarbon group.
The number of hydrogen atoms / number of fluorine atoms in Rf is preferably 1/4 or less, and more preferably 1/9 or less, in order to reduce the refractive index. When the number of hydrogen atoms / number of fluorine atoms in Rf is ¼ or less, the antifouling property is good, which is preferable. On the other hand, when the number of hydrogen atoms / number of fluorine atoms in Rf exceeds ¼, the refractive index of the polymer increases, and the average reflectance when formed into a coating film increases, which is not preferable.
n represents an integer of 3 or more. In order to obtain sufficient film strength, n is preferably 4 or more. Rf is preferably a group having a molecular weight between crosslinks of 300 or less when all polymerizable groups are polymerized (or crosslinked). The molecular weight between crosslinks will be described later.

  Specific examples of the “fluorine-containing core portion” represented by Rf include the following specific examples.

In the general formula (1), Y represents a polymerizable group, and is preferably a radical, a cation, or a condensation polymerizable group, and is a (meth) acryloyl group, an allyl group, an alkoxysilyl group, an α-fluoroacryloyl group, An epoxy group and a group selected from —C (O) OCH═CH ₂ are more preferable. Among these, from the viewpoint of polymerizability, a group selected from a (meth) acryloyl group, an allyl group, an α-fluoroacryloyl group, an epoxy group, and —C (O) OCH═CH ₂ having radical or cationic polymerizability. A group selected from a (meth) acryloyl group, an allyl group, an α-fluoroacryloyl group, and —C (O) OCH═CH ₂ having radical polymerizability is particularly preferable. The composition for forming the layer (A) is preferably a photocurable composition in order to obtain scratch resistance and wet heat resistance of the film.

  L represents a divalent linking group, preferably an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, -O-, -S-, -N (R)-, 1 to carbon atoms. A group obtained by combining 10 alkylene group and —O—, —S— or N (R) —, a combination of an arylene group having 6 to 10 carbon atoms and —O—, —S— or N (R) —. Represents the resulting group. R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. When L represents an alkylene group or an arylene group, the alkylene group and the arylene group represented by L are preferably substituted with a halogen atom, and preferably substituted with a fluorine atom.

  (A1) More preferable as the fluorine-containing polymerizable compound is a monomer containing 35% by mass or more of fluorine from the viewpoint of refractive index and polymerizability, and having a calculated value of all cross-linking molecular weights smaller than 500, And it is represented by the following general formula (2) or (3).

Formula _{^{(2): Rf 2 - {}} CH 2 -OC (O) CH = CH 2} n
Formula ^{(3): Rf 2 - {} C (O) OCH = CH 2} n

In general formulas (2) and (3), Rf ² represents an n-valent group containing at least a carbon atom and a fluorine atom, and n represents an integer of 3 or more. Rf ² is a chain (straight or branched) or cyclic.
Rf is preferably substantially composed of a carbon atom and a fluorine atom, or only a carbon atom, a fluorine atom, and an oxygen atom for the purpose of developing a lower refractive index. The term “substantially composed of carbon atoms and fluorine atoms, or only carbon atoms, fluorine atoms and oxygen atoms” means that other atoms (eg, hydrogen The number of atoms is 10% or less.

  Further, (a1) a fluorine-containing polymerizable compound containing 35% by mass or more of fluorine, a monomer having all calculated molecular weights between crosslinks smaller than 500, and the following general formula (4) or (5) What is represented by these is also preferable.

Formula _{^{(4): Rf 21 - {}} Rf 22 -CH 2 -OC (O) CH = CH 2} n
Formula ^{(5): Rf 21 - {} Rf 22 -C (O) OCH = CH 2} n

(In the general formulas (4) and (5), Rf ²¹ represents an n-valent group containing at least a carbon atom and a fluorine atom, and Rf ²² represents a divalent group containing at least a carbon atom and a fluorine atom. 3 represents an integer greater than or equal. However, ^{Rf 21} in the end do not contain _-CH 2 OH.)
Rf ²¹ and Rf ²² may contain at least one of an oxygen atom and a hydrogen atom. Rf ²¹ and Rf ²² are linear (straight or branched) or cyclic.

  Here, the calculated value of the molecular weight between crosslinks is (a1) a polymer in which all of the polymerizable unsaturated groups of the fluorine-containing polymerizable compound are polymerized, and at least one of carbon atom, silicon atom, and oxygen atom is combined. (A) and (a) and (a) and (a) a silicon atom substituted with at least one of carbon atoms and oxygen atoms (b). ), (B) and (b), or the total atomic weight of atomic groups sandwiched between (a) and (b). For example, X-22 will be described as an example among the fluorine-containing polyfunctional monomers described later. Assuming that all the polymerizable groups of X-22 are polymerized, the following X-22-1 is expressed.

In this case, the partial structure that is the target of calculation of the molecular weight between crosslinks defined above is a portion surrounded by a broken line, and the calculated values of the molecular weight between crosslinks are C ₂ F ₄ O = 16.0, and C ₅ H, respectively. ₂ F ₆ O ₃ = 224.1, both of which are less than 500.

  Moreover, the calculated value of the molecular weight between bridge | crosslinking can also be represented as follows. That is, the calculated value of the molecular weight between crosslinks is bonded to each of the three or more polymerizable unsaturated groups via a divalent or higher valent linking group containing a carbon atom, a silicon atom, or an oxygen atom, and the linking group. (A) a carbon atom directly bonded to a carbon atom, a silicon atom, or an oxygen atom therein, and (b) a silicon atom in which at least one of the carbon atom and the oxygen atom is substituted (b) Of the two carbon atoms forming the unsaturated bond of the saturated group, when the carbon atom closer to the carbon atom of (a) is (c), (a) and (a), (b) and ( b), (c) and (c), (a) and (b), (a) and (c), or (b) and the total atomic weight of the atomic group sandwiched between (c). For example, X-22 will be described as an example among the fluorine-containing polyfunctional monomers described later. Regarding X-22, the carbon atom corresponding to (a) or (c) in the above definition is represented as follows.

In this case, the partial structure that is the target of calculation of the molecular weight between crosslinks defined above is a portion surrounded by a broken line, and the calculated values of the molecular weight between crosslinks are C ₂ F ₄ O = 16.0, and C ₅ H, respectively. ₂ F ₆ O ₃ = 224.1, both of which are less than 500.

  The calculated value of the molecular weight between crosslinks is preferably larger than 50 and smaller than 500, more preferably larger than 50 and smaller than 400, most preferably larger than 50 and smaller than 300. When the molecular weight between crosslinks is 500 or more, the hardness of the coating film may decrease. On the other hand, if it is smaller than 50, the refractive index increases due to the decrease in the fluorine content.

  In order to obtain a lower refractive index, fluorine is preferably contained in an amount of 35% by mass or more, more preferably 40% by mass or more in one molecule.

Specific examples of the (a1) fluorine-containing polymerizable compound are shown below, but are not limited thereto.
In addition to X-21 to 25 and X-27 to 31 described in paragraphs [0026] to [0027] of JP-A-2006-28409, the following compound X-33 can also be preferably used. Cf represents the fluorine content (mass%).

  Further, the following M-1 to M-16 described in paragraph numbers [0062] to [0065] of JP-A-2006-284761 can also be preferably used.

  Moreover, the compounds MA1-MA20 shown below can also be used preferably.

  In addition, the following compounds X-34, X-35, and MX1 can also be used.

  Further, (a1) the fluorine-containing polymerizable compound contains 35% by mass or more of fluorine, and is a monomer having a calculated value of all cross-linking molecular weights smaller than 500, and is represented by the following general formula (6). Those are also preferred.

In the formula, Rf ³ represents a (p + q) -valent group containing at least a carbon atom and a fluorine atom, p is an integer of 2 to 10, q is an integer of 1 to 8, and (p + q) is an integer of 3 to 11. Represents. Rf ³ may be linear or branched, and may have a ring structure or an ether bond. Rf ³ is more preferably a (p + q) -valent group consisting of only carbon and fluorine atoms, or a (p + q) -valent group consisting of only carbon, fluorine and oxygen atoms. Rf ³ preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms. While indicating preferred examples of Rf ³ below, the present invention is not limited thereto.

p is preferably an integer of 3 to 6, and at this time, q is preferably an integer of 1 to 3, and (p + q) is an integer of 3 to 6.
r represents the number of repeating units (OCF ₂ CF ₂ ) in the general formula (6), and can be selected in a range where the calculated value of the molecular weight between crosslinks is smaller than 500, preferably 1 or 2, more preferably 1. The polyfunctional fluorine-containing acrylate represented by the general formula (6) has p linking groups represented by — (OCF ₂ CF ₂ ) _r —OCF ₂ CH ₂ O— in one molecule. Each r in one molecule may be the same or different. When r is 2 or less, the density of the crosslinking group is increased, and this is preferable from the viewpoint of enhancing the strength of the coating film. In particular, the surface layer of the coating film can be effectively effected and has excellent antifouling durability.
R represents a hydrogen atom, a methyl group, a fluorine atom or a trifluoromethyl group, preferably a hydrogen atom.

  The polyfunctional fluorine-containing acrylate represented by the general formula (6) may be used alone or in combination of two or more. Specific examples of the polyfunctional fluorine-containing acrylate represented by the general formula (6) are shown below. Here, a case where r = 1 is shown as a representative example, but the present invention is not limited to these.

  The polyfunctional fluorine-containing acrylate represented by the general formula (6) can be easily synthesized using the liquid phase fluorination reaction described in International Publication No. 90/03353 and International Publication No. 00/56694. .

  The fluorine content of the above exemplary compounds and the molecular weight between crosslinks (the larger one when there are two or more) are as follows.

  In addition to the above exemplary compounds, X-26, X-32, and the like described in paragraphs [0026] to [0027] of JP-A-2006-28409 having an epoxy group or an alkoxysilyl group as a polymerizable group. M-15 described in paragraph No. [0065] of Kaikai 2006-284761, the following compounds (MA-6, 16) and the like can also be preferably used.

  Among these, it is particularly preferable to use M-1 from the viewpoint of obtaining a coating film having high scratch resistance, low refractive index, and antifouling durability.

  Since the (a1) fluorine-containing polymerizable compound in the present invention has a high fluorine content in the molecule, the refractive index is low. Therefore, the refractive index of the layer can be lowered with a smaller amount of addition than when a conventional polymerizable compound is used. Therefore, even if conductive particles having a high refractive index are densely dispersed in the layer, the refractive index of the layer can be lowered, and a low refractive index can be achieved without impairing conductivity.

  The (a1) fluorine-containing polymerizable compound in the present invention can be preferably used not only as the layer (A) but also as a constituent component of the layer (B).

  As a method for producing these (a1) fluorine-containing polymerizable compounds, a compound having an ester bond, a dialkoxy group, and / or a halogen atom is subjected to liquid phase fluorination, whereby 80 mol% or more, preferably 90 mol% or more. A method of introducing three or more polymerizable groups after substituting the hydrogen atom with a fluorine atom is preferred. Liquid phase fluorination is described, for example, in US Pat. No. 5,093,432.

  The compound subjected to liquid phase fluorination is required to be dissolved in a fluorine-based solvent used for liquid phase fluorination or to be liquid, but there is no particular limitation other than that. From the viewpoint of such solubility and reactivity, a compound containing fluorine in advance may be used. A compound having an ester bond, a dialkoxy group, and / or a halogen atom is preferable because it can serve as a reaction point when a polymerizable group is introduced after liquid phase fluorination. By introducing fluorine atoms by liquid phase fluorination, it is possible to extremely increase the fluorine content of the portion other than the polymerizable group to be introduced later, and to obtain a polymerizable compound having an extremely low refractive index. it can.

  (A1) The molecular weight of the fluorine-containing polymerizable compound is preferably smaller than 5,000. If the molecular weight is less than 5,000, compatibility with other materials contained in the composition does not decrease, and the viscosity of the composition is unlikely to increase, so that surface failure is unlikely to occur. Moreover, when the molecular weight is larger than 200, the compound is less likely to be volatilized before polymerization, which is preferable.

  The content of the (a1) fluorine-containing polymerizable compound with respect to the solid content in the composition is preferably 10 to 80% by mass. If the content of the (a1) fluorine-containing polymerizable compound is 10% by mass or more, it is preferable because the refractive index does not increase and the film strength does not decrease. If it is 80 mass% or less, since sufficient antistatic property can be obtained, it is preferable. In order to obtain a sufficiently low refractive index, film strength, and antistatic properties, the content is more preferably 20 to 70% by mass.

(Conductive material)
The material that can be used as the conductive material (a2) contained in the layer (A) will be described. The layer (A) has a function as an antistatic layer by containing a conductive material.
Examples of the conductive material include a conductive inorganic material and a conductive organic material. Examples of the conductive inorganic material include conductive inorganic compounds, and metals, metal oxides, metal nitrides, and the like are preferable. The conductive organic material is a transparent and conductive substance made of a polymer, and includes a single material or a composite of a plurality of materials. A cationic or anionic polymer exhibiting ionic conductivity, or a complex of a π-conjugated conductive polymer exhibiting electronic conductivity and an accompanying dopant is preferably used. In particular, a complex of a π-conjugated conductive polymer and an accompanying dopant is preferable. Specific examples of the conductive organic material include compounds described in paragraph numbers [0165] to [0188] of JP-A-2008-262187.

  Examples of the method for forming a layer containing a conductive material include a method of applying a conductive coating solution containing conductive fine particles and (a1) a fluorine-containing polymerizable compound, and a transparent conductive material made of a transparent and conductive polymer. A conventionally known method such as a method of applying a material can be exemplified. The layer containing a conductive material can be formed on the transparent support directly or via a primer layer that strengthens adhesion to the transparent support. The coating method is not particularly limited, and an optimal method may be selected from known methods such as roll coating, gravure coating, bar coating, extrusion coating, etc., depending on the characteristics of the coating solution and the coating amount. .

  It is preferable that the layer (A) containing a conductive material is substantially transparent. Specifically, the haze is preferably 10% or less, more preferably 5% or less, still more preferably 3% or less, and most preferably 1% or less. The transmittance of light having a wavelength of 550 nm is preferably 50% or more, more preferably 60% or more, still more preferably 65% or more, and most preferably 70% or more.

  The layer (A) is preferably formed using a coating composition obtained by mixing conductive inorganic fine particles and (a1) a fluorine-containing polymerizable compound with a solvent. In this case, the conductive inorganic fine particles are preferably formed from a metal oxide or nitride. Examples of metal oxides or nitrides include tin oxide, indium oxide, zinc oxide, titanium nitride, ruthenium oxide, rhenium oxide, silver oxide, nickel oxide and copper oxide. Tin oxide and indium oxide are particularly preferred. The conductive inorganic fine particles are mainly composed of these metal oxides or nitrides, and may further contain other elements. The main component means a component having the largest content (mass%) among the components constituting the particles. Examples of other elements include Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P, S, B, Nb, In, V and halogen atoms are included. In order to increase the conductivity of tin oxide and indium oxide, it is preferable to add at least one selected from Sb, P, B, Nb, In, V, and a halogen atom. More specifically, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), phosphorus-doped tin oxide (PTO), zinc antimonate, indium-doped zinc oxide (IZO), oxidation Examples thereof include a combination of one or more metal oxides selected from the group consisting of zinc, ruthenium oxide, rhenium oxide, silver oxide, nickel oxide, and copper oxide. Tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), and phosphorus-doped tin oxide (PTO) are particularly preferred. The ratio of Sb in ATO is preferably 3 to 20% by mass. The ratio of tin in ITO is preferably 5 to 20% by mass.

  The average primary particle diameter of the conductive inorganic fine particles used in the layer (A) is preferably 1 to 150 nm, more preferably 5 to 100 nm, and most preferably 5 to 70 nm. The average particle diameter of the conductive inorganic fine particles in the antistatic layer to be formed is 1 to 200 nm, preferably 5 to 150 nm, more preferably 10 to 100 nm, and more preferably 10 to 80 nm. Most preferred. The average particle diameter of the conductive inorganic fine particles is an average diameter weighted by the mass of the particles, and can be measured by a light scattering method or an electron micrograph.

The conductive inorganic fine particles may be surface-treated. The surface treatment is performed using an inorganic compound or an organic compound. Examples of inorganic compounds used for the surface treatment include alumina and silica. Silica treatment is particularly preferred. Examples of organic compounds used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Silane coupling agents are most preferred. Specifically, the method described in {Surface treatment method of inorganic fine particles} in the layer (B) described later is preferably used. In addition, the methods described in paragraph numbers [0101] to [0122] of JP-A-2008-31327 can also be preferably used. Two or more kinds of surface treatments may be performed in combination.
The shape of the conductive inorganic fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape or an indefinite shape.
Two or more kinds of conductive inorganic fine particles may be used in combination in the antistatic layer.

  The ratio of the conductive material such as conductive inorganic fine particles in the layer (A) is preferably 20 to 90% by mass, more preferably 25 to 85% by mass, and more preferably 30 to 80% by mass in the total solid content. % Is more preferable, and 40 to 80% by mass is most preferable. If it is smaller than this range of the inorganic fine particles, sufficient antistatic ability cannot be expressed, and if it is larger than this range, sufficient film strength cannot be obtained.

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

  The conductive inorganic compound particles are preferably reacted with an alkoxysilane compound in an organic solvent. By using a reaction liquid in which conductive inorganic compound particles and an alkoxysilane compound are reacted in advance, an effect of excellent storage stability and curability can be obtained.

  As a commercial item as powder of the above-mentioned conductive inorganic oxide particles, for example, Mitsubishi Materials Corporation trade name: T-1 (ITO), EP SP2 (PTO), Mitsui Kinzoku Corporation trade name: Pastoran (ITO, ATO), Ishihara Sangyo Co., Ltd. trade name: SN-100P (ATO), CI Kasei Co., Ltd. trade name: Nanotech ITO, Nissan Chemical Industries Ltd. trade name: ATO, FTO, catalyst Product name: ELCOM TL-30S (PTO) etc. can be mentioned by Kasei Kogyo Co., Ltd.

  Conductive inorganic oxide particles having silicon oxide supported on the surface thereof are preferable because they react particularly effectively with alkoxysilane compounds. As a method for carrying such silicon oxide, for example, it is disclosed in Japanese Patent No. 2858271. After forming a coprecipitate of a hydrate of tin oxide and antimony oxide, a silicon compound is deposited. It can be manufactured by the steps of fractionation and firing.

  As a commercial item of the electroconductive inorganic oxide particle which carry | supports a silicon oxide on the surface, for example, Ishihara Sangyo Co., Ltd. brand name: SN-100P (ATO), SNS-10M, FSS-10M etc. Can be mentioned.

  The inorganic oxide particles can be used in a state of being dispersed in a powder or a solvent. However, since the uniform dispersibility is easily obtained, the inorganic oxide particles are preferably used in a state of being dispersed in a solvent. In the case of a powder, a dispersant may be used for uniform dispersion in a solvent. Examples of the powdery particle dispersant include TR701, TR702, TR704 and the like, which are surfactants manufactured by Asahi Denka Kogyo Co., Ltd.

  Commercially available products in which conductive inorganic oxide particles are dispersed in an organic solvent include, for example, trade names: SNS-10M (MEK-dispersed antimony-doped tin oxide), FSS-10M (isopropyl alcohol-dispersed antimony) manufactured by Ishihara Sangyo Co., Ltd. Dope tin oxide), manufactured by Nissan Chemical Industries, Ltd. Trade name: Celnax CX-Z401M (methanol-dispersed zinc antimonate), Celnax CX-Z200IP (isopropyl alcohol-dispersed zinc antimonate), Catalyst Chemical Industries, Ltd. Product name: ELCOM JX-1001PTV (phosphorus-containing tin oxide dispersed in propylene glycol monomethyl ether) and the like.

(Other ingredients)
The components that may be included in the composition for forming the layer (A) in addition to the (a1) fluorine-containing polymerizable compound and (a2) the conductive material will be described.
The composition for forming the layer (A) may contain a polymerizable compound (monomer or oligomer) or polymer having a polymerizable unsaturated group in the molecule as a binder.
The polymerizable compound is preferably a polyfunctional monomer, and examples thereof include compounds having a polymerizable functional group such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a compound having a (meth) acryloyl group Is preferred. Particularly preferred are compounds containing two or more (meth) acryloyl groups in one molecule.

  As a polymerizable compound having a fluorine atom and a polymerizable unsaturated group in the molecule, compounds described in paragraph numbers [0054] to [0079] of JP-A-2008-134585, paragraph number [0008] of Japanese Patent No. 3890022 To [0017] and the compounds described in JP-A No. 11-80312, paragraphs [0011] to [0013].

Specific examples of the compound having a polymerizable unsaturated bond that does not contain a fluorine atom include alkylene glycol (meta) such as neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate, propylene glycol di (meth) acrylate, and the like. ) Acrylic acid diesters;
(Meth) acrylic acid diesters of polyoxyalkylene glycols such as triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate;
(Meth) acrylic acid diesters of polyhydric alcohols such as pentaerythritol di (meth) acrylate;
(Meth) acrylic acid diesters of ethylene oxide or propylene oxide adducts such as 2,2-bis {4- (acryloxy · diethoxy) phenyl} propane and 2-bis {4- (acryloxy · polypropoxy) phenyl} propane ;
Etc.

  Furthermore, epoxy (meth) acrylates, urethane (meth) acrylates, and polyester (meth) acrylates are also preferably used as the photopolymerizable polyfunctional monomer.

  Among these, esters of polyhydric alcohol and (meth) acrylic acid are preferable. More preferably, a polyfunctional monomer having 3 or more (meth) acryloyl groups in one molecule is preferable. For example, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO Modified tri (meth) acrylate phosphate, trimethylolethane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa ( (Meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-chlorohexane tetramethacrylate, polyurethane polyacrylate Over DOO, polyester polyacrylate and caprolactone-modified tris (acryloyloxyethyl) isocyanurate.

  Specific compounds of polyfunctional acrylate compounds having a (meth) acryloyl group are described in paragraph [0119] of JP-A-2009-98658, and the same applies to the present invention.

  Furthermore, resins having three or more (meth) acryloyl groups, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins. And oligomers or prepolymers such as polyfunctional compounds such as polyhydric alcohols.

  As the monomer binder, for example, dendrimers described in JP-A-2005-76005 and JP-A-2005-36105, and norbornene ring-containing monomers as described in JP-A-2005-60425 can be used.

  Two or more polyfunctional monomers may be used in combination. Polymerization of the monomer having an ethylenically unsaturated group can be carried out by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.

(Polymer binder)
As the binder, not only a polyfunctional monomer or polyfunctional oligomer but also a crosslinked polymer obtained by reacting a reactive curable resin can be used as the binder. The polymer binder is described in paragraph numbers [0194] to [0200] of JP-A-2008-262187, and the same applies to the present invention.

(Organic solvent)
The organic solvent used in the composition for forming the layer (A) is used as a dispersion medium for dispersing a conductive material such as conductive inorganic oxide particles.
The content of the organic solvent is preferably 20 to 4,000 parts by mass, and more preferably 100 to 1,000 parts by mass with respect to 100 parts by mass of the conductive material. When the amount of the solvent is less than 20 parts by mass, a uniform reaction may be difficult due to the high viscosity, and when it exceeds 4,000 parts by mass, the coatability may be deteriorated.

  As an organic solvent, the solvent whose boiling point in a normal pressure is 200 degrees C or less can be mentioned, for example. Specifically, alcohols, ketones, ethers, esters, hydrocarbons, and amides are used, and these can be used alone or in combination of two or more. Of these, alcohols, ketones, ethers and esters are preferred.

  Here, examples of alcohols include methanol, ethanol, isopropyl alcohol, isobutanol, n-butanol, tert-butanol, ethoxyethanol, butoxyethanol, diethylene glycol monoethyl ether, benzyl alcohol, phenethyl alcohol, and the like. . Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of ethers include dibutyl ether and propylene glycol monoethyl ether acetate. Examples of the esters include ethyl acetate, butyl acetate, and ethyl lactate. Examples of hydrocarbons include toluene and xylene. Examples of amides include formamide, dimethylacetamide, N-methylpyrrolidone and the like. Of these, isopropyl alcohol, ethoxyethanol, butoxyethanol, diethylene glycol monoethyl ether, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, propylene glycol monoethyl ether acetate, butyl acetate, and ethyl lactate are preferable.

  The layer (A) may contain other additives.

In order to make the reflected hue neutral, the optical film thickness (nd) of the layer (A) is preferably 200 nm to 300 nm, and more preferably 225 to 275 nm.
The refractive index of the layer (A) is preferably 1.50 to 1.60, and more preferably 1.52 to 1.58.

[Layer (B)]
The layer (B) is a low refractive index layer having a lower refractive index than the layer (A), and is disposed on the layer (A). In the antireflection film of the present invention, the layer (B) is preferably the outermost layer.
The layer (B) (also referred to as a low refractive index layer) preferably used in the present invention is obtained by a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method, particularly a vacuum vapor deposition method or a sputtering method which is a kind of physical vapor deposition method. Although it can also be formed by a transparent thin film of an inorganic oxide, it is preferably formed by all wet coating using a coating composition for low refractive index layer shape described later. The low refractive index layer preferably contains inorganic fine particles. At least one of the inorganic fine particles is preferably a hollow particle, and hollow particles containing silica as a main component (also referred to as hollow silica particles) are used. Particularly preferred.

The haze of the low refractive index layer is preferably 3% or less, more preferably 2% or less, and most preferably 1% or less.
The strength of the antireflection film formed up to the low refractive index layer is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test under a 500 g load.
In order to improve the antifouling performance of the antireflection film, it is preferable that the contact angle of the surface with respect to water is 90 ° or more. More preferably, it is 95 ° or more, and particularly preferably 100 ° or more.

  One of the preferred embodiments of the antireflection film of the present invention is that the fluorine-containing antifouling agent is applied to the outermost layer (B) for the purpose of imparting antifouling properties, water resistance, chemical resistance, slipping properties and the like. It is an aspect to contain. The fluorine-containing antifouling agent is characterized by having a polymerizable unsaturated group, thereby suppressing the back surface transfer of the fluorine compound during storage in a roll state of the coating and improving the scratch resistance of the coating film, The durability against repeated wiping of dirt can be improved.

(Coating composition for low refractive index layer type)
The coating composition for forming the low refractive index layer is optionally a fluorine-containing antifouling agent having a polymerizable unsaturated group, a fluorine-containing copolymer having a polymerizable unsaturated group, inorganic fine particles, a photopolymerization initiator, polymerization Containing a polyfunctional monomer having a polymerizable unsaturated group. The content of the fluorine-containing antifouling agent having a polymerizable unsaturated group in the solid content in the coating composition is preferably 1 to 15% by mass, more preferably 1 to 10% by mass, and most preferably 2 to 7% by mass. . The content of the fluorine-containing copolymer having a polymerizable unsaturated group is preferably 5 to 70% by mass, more preferably 5 to 50% by mass, and most preferably 5 to 30% by mass. The content of the inorganic fine particles is preferably 10 to 70% by mass, more preferably 20 to 60% by mass, and most preferably 35 to 55% by mass. The content of the photopolymerization initiator is preferably 1 to 5% by mass. The content of the polyfunctional monomer having a polymerizable unsaturated group is preferably 0 to 60% by mass, more preferably 5 to 60% by mass, particularly preferably 10 to 50% by mass, and 20 to 40% by mass. % Is most preferred. If the content of the fluorine-containing antifouling agent having a polymerizable unsaturated group is 1% by mass or more, an antifouling property improving effect is obtained, and if it is 15% by mass or less, surface deterioration due to crying does not occur. If the inorganic fine particles are 10% by mass or more, an effect of improving scratch resistance is obtained, and if the inorganic fine particles are 70% by mass or less, the surface shape such as whitening of the coating film is good. When the polyfunctional monomer having a polymerizable unsaturated group is 5 to 60% by mass, the scratch resistance, antifouling durability, coating property and refractive index are improved.

(Formation of a low refractive index layer)
The low refractive index layer is a crosslinking reaction or a polymerization reaction by applying ionizing radiation (for example, light irradiation, electron beam irradiation, etc.) or heating at the same time as coating the coating composition or after coating and drying. It is preferable to form by curing.
In particular, when the low refractive index layer is formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound, the crosslinking reaction or the polymerization reaction is preferably performed in an atmosphere having an oxygen concentration of 10% by volume or less. . By forming in an atmosphere having an oxygen concentration of 1% by volume or less, an outermost layer excellent in physical strength and chemical resistance can be obtained.
The oxygen concentration is preferably 0.5% by volume or less, more preferably the oxygen concentration is 0.1% by volume or less, particularly preferably the oxygen concentration is 0.05% by volume or less, and most preferably 0.02% by volume or less. is there.
As a method for reducing the oxygen concentration to 1% by volume or less, it is preferable to replace the atmosphere (nitrogen concentration of about 79% by volume, oxygen concentration of about 21% by volume) with another gas, particularly preferably replacement with nitrogen (nitrogen purge). It is to be.

(Fluorine-containing antifouling agent)
The low refractive index layer in the antireflection film of the present invention preferably contains the fluorine-containing antifouling agent for the purpose of imparting properties such as antifouling property, water resistance, chemical resistance and slipperiness. Further, the fluorine-containing antifouling agent is characterized by having a polymerizable unsaturated group, thereby suppressing the backside transfer of the fluorine compound during storage in a roll state of the coated product and improving the scratch resistance of the coating film. Further, durability against repeated wiping of dirt can be improved. Conventionally, it has been known to use a silicone compound having a dimethylsiloxane structure in order to develop antifouling properties, but there are cases where even better antifouling properties can be achieved by using a fluorine-containing antifouling agent. The fluorine-containing antifouling agent having a polymerizable unsaturated group is an antifouling agent containing a fluorine compound, and the polymerizable unsaturated group is not particularly limited, but a functional group having an unsaturated double bond is preferred, and most preferred Is a methacryloyloxy group or an acryloyloxy group.

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

  The fluorine-based compound preferably further has a substituent that contributes to bond formation or compatibility with the low refractive index layer film. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like. The fluorine-based compound may be a polymer or an oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferred fluorine-based compounds include Daikin Chemical Industries, Ltd., R-2020, M-2020, R-3833, M-3833, Optool DAC (trade name), Dainippon Ink Co., Ltd. Examples include, but are not limited to, F-171, F-172, F-179A, defender MCF-300, MCF-323 (and above, trade names).

  Moreover, the preferable aspect (general formula (F)) of the fluorine-containing compound which has a polymerizable unsaturated group in this invention is described in detail. The polymerizable compound may be a monomer, oligomer, or polymer.

  As a preferred first embodiment, a compound represented by the following general formula (F) can be exemplified.

Formula (F):
(Rf)-[(W)-(R _A ) _n ] _m
(In the formula, Rf represents a (per) fluoroalkyl group or a (per) fluoropolyether group, W represents a linking group, and _RA represents a functional group having an unsaturated double bond. N represents 1 to 3, and m represents 1) Represents an integer of ~ 3.

  In the compound represented by the general formula (F), W represents, for example, alkylene, arylene, heteroalkylene, or a linking group in combination thereof. Those linking groups may further contain a functional group such as carbonyl, carbonyloxy, carbonylimino, sulfonamide, or the like or a combination thereof.

  In the general formula (F), when n and m are 1 at the same time, specific examples of the following preferred embodiments include (F-1) to (F-3).

Formula (F-1):
_{Rf (CF 2 CF 2) n} CH 2 CH 2 R 2 OCOCR 1 = CH 2

(In the formula, Rf represents any of a fluoroalkyl group having 1 to 10 carbon atoms, R ¹ represents a hydrogen atom or a methyl group, R ² represents a single bond or an alkylene group, and n represents a degree of polymerization. The degree of polymerization n is k or more (k is any integer of 3 or more).)

Examples of the telomer acrylate containing a fluorine atom in the general formula (F-1) include a (meth) acrylic acid moiety or a fully fluorinated alkyl ester derivative.
The fluorine-containing antifouling agent is described in paragraph numbers [0129] to [0152] of JP-A No. 2007-114772, and the same applies to the present invention.

(Fluorine-containing copolymer having a polymerizable unsaturated group)
As the binder contained in the low refractive index layer, a fluorine-containing copolymer compound can be preferably used. The fluorine-containing copolymer having a polymerizable unsaturated group is described in paragraph numbers [0098] to [0112] of JP-A-2006-28409, and the same applies to the present invention.

  The preferred molecular weight of the polymer that can be preferably used in the present invention is a mass average molecular weight of 5,000 or more, preferably 10,000 to 500,000, most preferably 15,000 to 200,000. By using polymers having different average molecular weights in combination, it is possible to improve the surface state of the coating film and the scratch resistance.

  The binder contained in the low refractive index layer (B) preferably has a polymerizable group that can be covalently bonded to the binder contained in the layer (A) in order to ensure interlayer adhesion. The low refractive index layer (B) and the layer (A) preferably contain a (meth) acrylate compound as a binder, and more preferably contain a polyfunctional (meth) acrylate compound having a plurality of polymerizable groups in the molecule. .

[Inorganic fine particles]
It is preferable to use inorganic fine particles in the low refractive index layer from the viewpoint of lowering the refractive index and improving scratch resistance. The inorganic particles are not particularly limited as long as the average particle size is 5 to 120 nm, but inorganic low refractive index particles are preferable from the viewpoint of lowering the refractive index.

  Examples of the inorganic particles include magnesium fluoride and silica fine particles because of their low refractive index. In particular, silica fine particles are preferable in terms of refractive index, dispersion stability, and cost. The size (primary particle size) of these inorganic particles is preferably 5 to 120 nm, more preferably 10 to 100 nm, 20 to 100 nm, and most preferably 40 to 90 nm.

  If the particle size of the inorganic fine particles is too small, the effect of improving the scratch resistance is reduced. If the particle size is too large, fine irregularities are formed on the surface of the low refractive index layer, and the appearance such as black tightening and the integrated reflectance are deteriorated. The inorganic fine particles may be either crystalline or amorphous, and may be monodispersed particles or aggregated particles as long as a predetermined particle size is satisfied. The shape is most preferably a spherical diameter, but may be indefinite.

The coating amount of the inorganic fine particles is ^{preferably 1mg / m 2 ~100mg / m 2} , more preferably ^{5mg / m 2 ~80mg / m 2} , more preferably from ^{10mg / m 2 ~60mg / m 2} . When the amount is too small, the effect of improving the scratch resistance is reduced. When the amount is too large, fine irregularities are formed on the surface of the low refractive index layer, and the appearance such as black tightening and the integrated reflectance are deteriorated.

(Porous or hollow fine particles)
In order to reduce the refractive index, it is preferable to use fine particles having a porous or hollow structure. It is particularly preferable to use hollow structure silica particles. The porosity of these particles is preferably 10 to 80%, more preferably 20 to 60%, and most preferably 30 to 60%. It is preferable that the void ratio of the hollow fine particles be in the above range from the viewpoint of lowering the refractive index and maintaining the durability of the particles.

  When the porous or hollow particles are silica, the refractive index of the fine particles is preferably 1.10 to 1.40, more preferably 1.15 to 1.35, and most preferably 1.15 to 1.30. is there. The refractive index here represents the refractive index of the entire particle, and does not represent the refractive index of only the outer shell silica forming the silica particles.

The coating amount of the porous or hollow silica is ^preferably from ^{1mg / m 2 ~100mg / m 2} , more preferably ^{5mg / m 2 ~80mg / m 2} , more preferably is 10mg ^{/ m 2} ~60mg ^/ m 2 . If the amount is too small, the effect of lowering the refractive index and the effect of improving the scratch resistance will be reduced.

  If the particle size of the silica particles is too small, the proportion of cavities will decrease and a decrease in refractive index cannot be expected.If it is too large, fine irregularities will be formed on the surface of the low refractive index layer, and the appearance such as black tightening and integrated reflectance will be reduced. Getting worse. The silica fine particles may be either crystalline or amorphous, and monodisperse particles are preferred. The shape is most preferably a spherical diameter but may be indefinite.

  Further, two or more kinds of hollow silica having different particle average particle sizes can be used in combination. Here, the average particle diameter of the hollow silica can be determined from an electron micrograph.

The specific surface area of the hollow silica in the present invention is preferably from 20 to 300 m ² / g, more preferably 30~120m ² / g, most preferably 40~90m ² / g. The surface area can be determined by the BET method using nitrogen.

  In the present invention, silica particles having no voids can be used in combination with hollow silica. The preferred particle size of silica without voids is 30 nm to 150 nm, more preferably 35 nm to 100 nm, and most preferably 40 nm to 80 nm.

[Preparation method of porous or hollow fine particles]
A preferred method for producing hollow fine particles is described below. The first step is the formation of core particles that can be removed by post-treatment, the second step is the formation of a shell layer, the third step is the dissolution of core particles, and the fourth step is the formation of an additional shell phase if necessary. Specifically, the hollow particles can be produced according to the method for producing hollow silica fine particles described in, for example, JP-A-2001-233611.

  A preferred method for producing porous particles is to produce porous core particles by controlling the degree of hydrolysis and condensation of alkoxide and the type and amount of coexisting substances as the first step, and a shell layer on the surface as the second step. It is a method of forming. Specifically, the production of porous particles can be performed by the methods described in JP-A Nos. 2003-327424, 2003-335515, 2003-226516, 2003-238140, and the like. it can.

(Coated particles)
Increasing the shell thickness is preferable because the adsorption sites on the particle surface can be reduced and the amount of adsorbed water can be reduced. Furthermore, it is preferable to form a shell with a conductive component since conductivity can be imparted. Particularly preferred is a combination in which silica-based porous or hollow particles are used as the core particles, and ZnO ₂ , Y ₂ O ₃ , Sb ₂ O ₅ , ATO, ITO, SnO ₂ are used as the shell. The coated particles are described in paragraph numbers [0033] to [0040] of JP-A-2008-242314, and can be suitably used in the present invention.

[Inorganic fine particle surface treatment method]
The method for treating the surface of inorganic fine particles is described in paragraphs [0046] to [0076] of JP-A-2008-242314. The organosilane compound, the siloxane compound, the solvent for the surface treatment, the surface described in the document Treatment catalysts, metal chelate compounds, and the like can be suitably used in the present invention.

[Photopolymerization initiator]
The layer constituting the antireflection film of the present invention preferably contains a photopolymerization initiator. As photopolymerization initiators, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, Examples include fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, and coumarins. The photopolymerization initiator is also described in paragraphs [0141] to [0159] of JP-A-2008-134585, and can be suitably used in the present invention as well.

  “Latest UV Curing Technology” {Technical Information Association, Inc.} (1991), p. 159, and “UV Curing System” written by Kiyomi Kato (published by the General Technology Center in 1989), p. Various examples are also described in 65-148 and are useful in the present invention.

  Commercially available photocleavable photoradical polymerization initiators include “Irgacure 651”, “Irgacure 184”, “Irgacure 819”, “Irgacure 907”, “Irgacure 1870” (CGI) manufactured by Ciba Specialty Chemicals Co., Ltd. -403 / Irg184 = 7/3 mixing initiator), "Irgacure 500", "Irgacure 369", "Irgacure 1173", "Irgacure 2959", "Irgacure 4265", "Irgacure 4263", "Irgacure 127", "OXE01 “Kaya Cure DETX-S”, “Kaya Cure BP-100”, “Kaya Cure BDK”, “Kaya Cure CTX”, “Kaya Cure BMS”, “Kaya Cure 2-EAQ”, “Kaya Cure ABQ” manufactured by Nippon Kayaku Co., Ltd. ”,“ Kayaki Ar CPTX, Kaya Cure EPD, Kaya Cure ITX, Kaya Cure QTX, Kaya Cure BTC, Kaya Cure MCA, etc .; “Esacure (KIP100F, KB1, EB3, BP, X33, KTO46, KT37) manufactured by Sartomer , KIP150, TZT) ", etc., and combinations thereof are preferred examples.

  It is preferable to use a photoinitiator in the range of 0.1-15 mass parts with respect to 100 mass parts of binders, More preferably, it is the range of 1-10 mass parts.

  In addition to the photopolymerization initiator, a photosensitizer may be used. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone and thioxanthone. Further, one or more auxiliary agents such as an azide compound, a thiourea compound, and a mercapto compound may be used in combination.

  Examples of commercially available photosensitizers include “Kaya Cure (DMBI, EPA)” manufactured by Nippon Kayaku Co., Ltd.

(solvent)
Although it does not specifically limit as a solvent used for the coating composition which forms all the said layers, An alcohol solvent and a ketone solvent are used preferably. Specifically, acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexane, 2-heptanone, 4-heptanone, methyl isopropyl ketone, ethyl isopropyl ketone, diisopropyl ketone, methyl isobutyl ketone, methyl-t-butyl ketone, Examples thereof include diacetyl, acetylacetone, acetonylacetone, diacetone alcohol, mesityl oxide, chloroacetone, cyclopentanone, cyclohexanone, acetophenone, and the like. Among these, methyl ethyl ketone and methyl isobutyl ketone are preferable. These solvents may be used alone or in a mixture at an arbitrary mixing ratio.

  As the auxiliary solvent, an ester solvent such as propylene glycol monomethyl ether acetate or a fluorinated solvent (such as a fluorinated alcohol) can be appropriately used. These solvents may be used alone or in a mixture at an arbitrary mixing ratio.

  The refractive index of the low refractive index layer (B) is preferably 1.33 to 1.40 at a wavelength of 550 nm. By making the refractive index within this range, the reflectance can be lowered. Furthermore, in order to neutralize the reflected hue, the optical film thickness (nd) of the low refractive index layer (B) is preferably 100 to 200 nm. The refractive index is 1.33-1.38, and the optical film thickness is more preferably 100-150 nm.

  Further, the low refractive index layer may contain other additives. For example, a surfactant and the like can be mentioned.

(Application method)
The antireflection film of the present invention can be formed by the following method, but is not limited to this method. First, a coating composition containing components for forming each layer is prepared. Next, the coating composition is applied on a transparent support by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating or die coating, and heated and dried. A micro gravure coating method, a wire bar coating method, and a die coating method (see US Pat. No. 2,681,294 and JP-A-2006-122889) are more preferable, and a die coating method is particularly preferable.
After coating, the layer formed from the coating composition is cured by light irradiation or heating.

[Transparent support]
The transparent support in the antireflection film of the present invention will be described in detail.
The transparent support of the antireflection film of the present invention is not particularly limited, such as a transparent resin film, a transparent resin plate, a transparent resin sheet, and transparent glass. Transparent resin films include cellulose acylate films (for example, cellulose triacetate film (refractive index 1.48), cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film), polyethylene terephthalate film, polyethersulfone. Film, polyacrylic resin film, polyurethane resin film, polyester film, polycarbonate film, polysulfone film, polyether film, polymethylpentene film, polyetherketone film, (meth) acrylonitrile film polyolefin, alicyclic structure Polymer (Norbornene resin (Arton: trade name, manufactured by JSR Corporation, amorphous polyolefin (ZEONEX: Name, Nippon Zeon Co., Ltd.)), and the like. Among these, triacetyl cellulose, polyethylene terephthalate, is preferably a polymer having an alicyclic structure, particularly triacetyl cellulose.
Although the thickness of a transparent support body can use the thing of about 25 micrometers-1000 micrometers normally, Preferably it is 25 micrometers-250 micrometers, and it is more preferable that it is 30 micrometers-90 micrometers.
Although the arbitrary width | variety of a transparent support body can be used, the thing of 100-5000 mm is normally used from the point of handling, a yield, and productivity, and it is preferable that it is 800-3000 mm, 1000-2000 mm More preferably it is. The transparent support can be handled in the form of a roll, and is usually 100 m to 5000 m, preferably 500 m to 3000 m.
The surface of the transparent support is preferably smooth, and the average roughness Ra is preferably 1 μm or less, preferably 0.0001 to 0.5 μm, and 0.001 to 0.1 μm. More preferably.

(Cellulose acylate film)
Among them, a cellulose acylate film having high transparency, optically low birefringence, easy production, and generally used as a protective film for a polarizing plate is preferable, and a cellulose triacetate film is particularly preferable. The thickness of the transparent support is usually about 25 μm to 1000 μm.

  In the present invention, it is preferable to use cellulose acetate having an acetylation degree of 59.0 to 61.5% for the cellulose acylate film. The degree of acetylation means the amount of bound acetic acid per unit mass of cellulose. The degree of acetylation follows the measurement and calculation of the degree of acetylation in ASTM: D-817-91 (test method for cellulose acetate and the like). The viscosity average degree of polymerization (DP) of cellulose acylate is preferably 250 or more, and more preferably 290 or more.

  The cellulose acylate used in the present invention has a Mw / Mn (Mw is a mass average molecular weight, Mn is a number average molecular weight) value by gel permeation chromatography close to 1.0, in other words, a molecular weight distribution. Narrow is preferred. The specific value of Mw / Mn is preferably 1.0 to 1.7, more preferably 1.3 to 1.65, and most preferably 1.4 to 1.6. preferable.

In general, the hydroxyl groups at 2, 3, and 6 positions of cellulose acylate are not evenly distributed by 1/3 of the total substitution degree, and the substitution degree of the 6-position hydroxyl group tends to be small. In the present invention, it is preferable that the substitution degree of the 6-position hydroxyl group of cellulose acylate is larger than that of the 2- and 3-positions.
The hydroxyl group at the 6-position with respect to the total substitution degree is preferably substituted with 32% or more of an acyl group, more preferably 33% or more, and particularly preferably 34% or more. Furthermore, the substitution degree of the 6-position acyl group of cellulose acylate is preferably 0.88 or more. The 6-position hydroxyl group may be substituted with a propionyl group, butyroyl group, valeroyl group, benzoyl group, acryloyl group or the like, which is an acyl group having 3 or more carbon atoms, in addition to the acetyl group. The degree of substitution at each position can be determined by NMR.

  In the present invention, cellulose acylate is described in paragraph Nos. 0043 to 0044, Examples, Synthesis Example 1, Paragraph Nos. 0048 to 0049, Synthesis Examples 2, Paragraph Nos. 0051 to 0052, and Synthesis Example 3 of JP-A No. 11-5851. The cellulose acetate obtained by the method can be used.

(Polyethylene terephthalate film)
In the present invention, the polyethylene terephthalate film is also excellent in transparency, mechanical strength, planarity, chemical resistance and moisture resistance, and is preferably used because it is inexpensive.
In order to further improve the adhesion strength between the transparent plastic film and the hard coat layer provided thereon, the transparent plastic film is more preferably subjected to an easy adhesion treatment. Examples of commercially available PET films with an easily adhesive layer for optics include Cosmo Shine A4100 and A4300 manufactured by Toyobo Co., Ltd.

(Hard coat layer)
The antireflection film of the present invention preferably has a hard coat layer in order to impart the physical strength of the film. The hard coat layer is preferably provided between the transparent support and the layer (A). More preferably, the hard coat layer is provided in contact with the layer (A).

  The refractive index of the hard coat layer is preferably in the range of 1.48 to 2.00, more preferably 1.48 to 1.70, from the optical design for obtaining an antireflection film. is there. In the present invention, since there is at least one low refractive index layer on the hard coat layer, if the refractive index is too small, the antireflection property is lowered, and if it is too large, the color of the reflected light tends to be strong. is there.

From the viewpoint of imparting sufficient durability and impact resistance to the film, the thickness of the hard coat layer is usually about 0.5 μm to 50 μm, preferably 1 μm to 20 μm, and more preferably 5 μm to 20 μm.
The strength of the hard coat layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in the pencil hardness test. Furthermore, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound. For example, it may be formed by applying a coating composition containing an ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer on a transparent support and subjecting the polyfunctional monomer or polyfunctional oligomer to a crosslinking reaction or a polymerization reaction. it can.
The functional group possessed by the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer is preferably a light, electron beam or radiation polymerizable group, and among them, a photopolymerizable functional group is preferred.
Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group is preferable. Specifically, the same compounds as the polyfunctional monomer having a polymerizable unsaturated group described in the layer (B) can be preferably used.

  The binder contained in the hard coat layer preferably has a polymerizable group capable of covalently bonding with the binder contained in the layer (A) in order to ensure adhesion between the layers. The hard coat layer and the layer (A) preferably contain a (meth) acrylate compound as a binder, and more preferably contain a polyfunctional (meth) acrylate compound having a plurality of polymerizable groups in the molecule.

  The hard coat layer contains matte particles having an average particle diameter of 1.0 to 10.0 μm, preferably 1.5 to 7.0 μm, such as inorganic compound particles or resin particles, for the purpose of imparting internal scattering properties. May be.

  For the purpose of controlling the refractive index of the hard coat layer, a high refractive index monomer, inorganic particles, or both can be added to the binder of the hard coat layer. In addition to the effect of controlling the refractive index, the inorganic particles also have the effect of suppressing cure shrinkage due to the crosslinking reaction. In the present invention, a polymer formed by polymerizing the polyfunctional monomer and / or the high refractive index monomer after the formation of the hard coat layer, and the inorganic particles dispersed therein are referred to as a binder.

In the present invention, the refractive index (n _A ) of the layer (A) and the refractive index (n _HC ) of the hard coat layer preferably satisfy the following mathematical formula (1).
Formula (1): 0 ≦ | (n _A −n _HC ) / n _HC | ≦ 0.05
By reducing the difference in refractive index between the layer (A) and the hard coat layer, the hue of the reflected light can be neutralized. The refractive index difference between the layer (A) and the hard coat layer is more preferably 0 ≦ | (n _A −n _HC ) / n _HC | ≦ 0.03, and 0 ≦ | (n _A −n _HC ) / More preferably, n _HC | ≦ 0.02. As long as Expression (1) is satisfied, any of n _A > n _HC and n _A <n _HC may be used.

(Anti-glare layer)
The antireflection film of the present invention may have an antiglare layer. The antiglare layer is formed for the purpose of contributing to the film an antiglare property due to surface scattering and preferably a hard coat property for improving the hardness and scratch resistance of the film.

  As a method of forming the antiglare property, a method of laminating and forming a mat-shaped shaping film having fine irregularities on the surface as described in JP-A-6-16851, JP-A-2000-206317 The method of forming by curing shrinkage of ionizing radiation curable resin due to the difference in ionizing radiation dose as described in the above, the mass ratio of the good solvent to the translucent resin by drying as described in JP-A-2000-338310 A method of forming concavo-convex on the surface of the coating film by solidifying the translucent fine particles and the translucent resin by gelling by reducing the surface, and surface undulation by external pressure as described in JP-A-2000-275404 There are known methods for imparting, and these known methods can be used.

The antiglare layer that can be used in the present invention preferably contains a binder capable of imparting hard coat properties, translucent particles for imparting antiglare properties, and a solvent as components, and the translucent particles themselves It is preferable that surface irregularities are formed by the protrusions or protrusions formed by an aggregate of a plurality of particles.
The antiglare layer formed by dispersing the matte particles is composed of a binder and translucent particles dispersed in the binder. The antiglare layer having antiglare properties preferably has both antiglare properties and hard coat properties.

(Layer structure of antireflection film)
The antireflection film of the present invention comprises a transparent support, a layer (A), and a layer (B). Further, a hard coat layer, an antiglare layer, a high refractive index layer having a higher refractive index than the layer (A), a medium refractive index layer having a lower refractive index than the layer (A) and a higher refractive index than the layer (B). Etc. may be included.
Examples of the layer structure of the antireflection film of the present invention are shown below. The antistatic layer represents the layer (A), and the low refractive index layer represents the layer (B).
Transparent support / antistatic layer / low refractive index layerTransparent support / hard coat layer / antistatic layer / low refractive index layerTransparent support / antiglare layer / antistatic layer / low refractive index layer / transparent support Body / hard coat layer / antiglare layer / antistatic layer / low refractive index layer / transparent support / antiglare layer / hard coat layer / antistatic layer / low refractive index layer / transparent support / hard coat layer / high refraction Index layer / Antistatic layer / Low refractive index layer / Base film / Hard coat layer / Medium refractive index layer / Antistatic layer / Low refractive index layer In the present invention, from the viewpoint of adhesion between layers and productivity,
Transparent support / antistatic layer (layer (A)) / low refractive index layer (layer (B))
-Transparent support / hard coat layer / antistatic layer / low refractive index layer is more preferred.

(Characteristics of antireflection film)
The antireflection film of the present invention has a surface resistivity of 1 × 10 ¹² Ω / □ or less. By setting the surface resistivity of the antireflection film to 1 × 10 ¹² Ω / □ or less, adhesion of dust due to static electricity can be suppressed. Preferably the surface resistivity of 1 × ¹⁰ 5 ~1 × is ^{10 12 Ω} / □, and further preferably ^{1 × 10 5 ~1 × 10 11} Ω / □ is. Such a surface resistivity can be achieved by using the conductive material. Furthermore, the total thickness of the layers formed on the layer using the conductive layer is preferably 1 μm or less in order not to impair the antistatic property.

The specular reflectance and color of the antireflection film are measured by attaching an adapter “ARV-474” to a spectrophotometer “V-550” (manufactured by JASCO Corporation), and in the wavelength region of 380 to 780 nm. The antireflection property can be evaluated by measuring the specular reflectance of the outgoing angle −θ at the incident angle θ (θ = 5 to 45 °, 5 ° interval), and calculating the average reflectance of 450 to 650 nm. Furthermore, from the measured reflectance spectra, ^{L *} value of the CIE1976L ^* a ^* b ^* color space representing the color of specular reflection light with respect to incident light of each angle of incidence of the CIE standard illuminant D65, ^{a *} value, and ^{b *} value It is possible to calculate and evaluate the color of the reflected light.
The reflectance is preferably 3% or less, and more preferably 2% or less. In the L ^* a ^* b ^* color space, it is preferable that 0 ≦ a ^* ≦ 3 and −3 ≦ b ^* ≦ 3.

The refractive index of each layer can be measured with a multi-wavelength Abbe refractometer DR-M2 (manufactured by Atago Co., Ltd.) by applying the coating solution of each layer to a glass plate so as to have a thickness of 3 to 5 μm. . In this specification, a refractive index measured using a filter of “DR-M2, M4 interference filter 546 (e) nm, part number: RE-3523” is adopted as a refractive index at a wavelength of 550 nm.
The film thickness of each layer can be measured by cross-sectional observation using a reflection spectral film thickness meter “FE-3000” (manufactured by Otsuka Electronics Co., Ltd.) utilizing light interference or a TEM (transmission electron microscope). Although the reflection spectral film thickness meter can also measure the refractive index simultaneously with the film thickness, it is desirable to use the refractive index of each layer measured by another means in order to increase the measurement accuracy of the film thickness. When the refractive index of each layer cannot be measured, the film thickness measurement by TEM is desirable. In that case, it is desirable to measure 10 or more locations and use an average value.

  It is preferable that the antireflection film of the present invention has a form in which the film is rolled up in the form during production. In that case, in order to obtain the neutrality of the color of the reflected color, the average value d (average value), minimum value d (minimum value), and maximum value d (maximum value) of the layer thickness in an arbitrary 1000 m long range The value of the layer thickness distribution calculated by the following formula (6) using the value) as a parameter is preferably 5% or less for each layer, more preferably 4% or less, still more preferably 3% or less, more More preferably, it is particularly preferably 2.5% or less and 2% or less.

  Formula (6): (maximum value d−minimum value d) × 100 / average value d

[Protective film for polarizing plate]
When the antireflection film is used as a surface protective film for a polarizing film (protective film for polarizing plate), the surface of the transparent support opposite to the side having the layer, that is, the surface to be bonded to the polarizing film is made hydrophilic. Thus, it is possible to improve adhesion with a polarizing film containing polyvinyl alcohol as a main component.
Of the two protective films of the polarizer, the film other than the antireflection film is preferably an optical compensation film having an optical compensation layer comprising an optically anisotropic layer. The optical compensation film (retardation film) can improve the viewing angle characteristics of the liquid crystal display screen.
A known film can be used as the optical compensation film, but the optical compensation film described in JP-A-2001-100042 is preferable in terms of widening the viewing angle.

  When the antireflection film is used as a surface protective film for a polarizing film (protective film for polarizing plate), it is particularly preferable to use a triacetyl cellulose film as the transparent support.

  As a method for producing a protective film for a polarizing plate in the present invention, (1) each layer constituting the above antireflection film on one surface of a transparent support previously saponified (eg, high refractive index layer, low refractive index) A layer, preferably a hard coat layer, that is, a layer of the antireflection film excluding the transparent support (hereinafter also referred to as “antireflection layer”), (2) one of the transparent supports A method of saponifying the side or both sides to be bonded to the polarizing film after coating an antireflection layer on the surface; (3) a polarizing film after coating a part of the antireflection layer on one surface of the transparent support; The method of applying the remaining layer after saponifying the side or both sides to be bonded to each other is mentioned. (1) is hydrophilicized to the surface on which the antireflection layer is to be applied, Since it becomes difficult to ensure adhesion with the antireflection layer, (2) The law is particularly preferred.

[Polarizer]
Next, the polarizing plate of the present invention will be described. The polarizing plate of the present invention has a polarizing film and two protective films for protecting both surfaces of the polarizing film, and at least one of the protective films is the antireflection film of the present invention.

  An example of preferable embodiment of the polarizing plate of this invention is shown. The polarizing plate of a preferable aspect has the antireflection film of this invention in at least one of the protective film (polarizing plate protective film) of a polarizing film. That is, the transparent support of the antireflection film is adhered to the polarizing film through an adhesive layer made of polyvinyl alcohol, if necessary, and has a protective film on the other side of the polarizing film. The surface of the other protective film opposite to the polarizing film may have an adhesive layer.

  By using the antireflection film of the present invention as a protective film for a polarizing plate, a polarizing plate having an antireflection function excellent in physical strength and light resistance can be produced, and the cost can be greatly reduced and the display device can be thinned. .

  Moreover, the polarizing plate of the present invention can also have an optical compensation function. In that case, only one surface side of the surface and the back surface of the two surface protective films is formed using the antireflection film, and the side having the antireflection film of the polarizing plate is the surface on the other surface side. It is preferable that the protective film is an optical compensation film.

  By producing a polarizing plate using the antireflection film of the present invention as one of the protective films for polarizing plates and the optical compensation film having optical anisotropy as the other protective film of the polarizing film, a liquid crystal display device is further produced. The contrast in the bright room and the viewing angle of the top, bottom, left and right can be improved.

[Image display device]
The image display device of the present invention has the antireflection film or polarizing plate of the present invention on the outermost surface of the display.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention should not be construed as being limited thereto.

<Example 1>
[Preparation of antireflection film]
(Formation of hard coat layer)
The following composition was put into a mixing tank and stirred to obtain a hard coat layer coating solution.
To 900 parts by mass of methyl ethyl ketone (MEK), 100 parts by mass of cyclohexanone, 750 parts by mass of partially caprolactone-modified polyfunctional acrylate (DPCA-20, Nippon Kayaku Co., Ltd.), silica sol (MIBK-ST, Nissan Chemical Industries ( 200 parts by mass) and 50 parts by mass of a photopolymerization initiator (Irgacure 184, Ciba Specialty Chemicals) were added and stirred. The solution was filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution for a hard coat layer.
On a triacetyl cellulose film (thickness 80 μm, TD80UF, manufactured by Fuji Film Co., Ltd., refractive index 1.48) as a transparent support, a hard coat layer coating solution having the above composition was applied using a gravure coater. After drying at 100 ° C., an irradiance of 400 mW / cm using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 160 W / cm while purging with nitrogen so that the oxygen concentration becomes 1.0 vol% or less. ^2. Irradiation with an irradiation amount of 150 mJ / cm ² was applied to cure the coating layer to form a hard coat layer having a refractive index of 1.52 and a thickness of 12 μm.

(Preparation of coating solution for layer (A) (antistatic layer))
Antimony-containing tin oxide (ATO) particles (manufactured by Ishihara Sangyo Co., Ltd., SN-100P, primary particle size 10-30 nm), dispersant (manufactured by Asahi Denka Kogyo Co., Ltd., Adeka Pluronic TR-701), and methanol, They were mixed in a blending amount of 29.1 / 0.9 / 70 (mass ratio) (total solid content 30 mass%, total inorganic content 29.1 mass%). ATO particles were dispersed using a media disperser (using zirconia beads having a diameter of 0.1 mm) to prepare an ATO dispersion.
In a container shielded from ultraviolet rays, 21 parts by mass of the ATO particle dispersion, 4 parts by mass of the following fluorine-containing polymerizable compound (fluorine content 44%, molecular weight between cross-links 58), photopolymerization initiator (Ciba Specialty Chemicals) Co., Ltd. Irgacure 184) 0.1 parts by mass, 10 parts by mass of methanol and 64.9 parts by mass of methyl isobutyl ketone were stirred at room temperature for 2 hours to obtain an antistatic layer coating solution (A-1).

(Formation of antistatic layer)
On the said hard-coat layer, the coating liquid (A-1) for antistatic layers was apply | coated using the gravure coater. After drying at 90 ° C. for 30 seconds, it was cured by ultraviolet irradiation. The ultraviolet curing conditions were as follows: nitrogen purge so that the atmosphere had an oxygen concentration of 1.0% by volume or less, and an irradiance of 300 mW / cm ² , using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 180 W / cm, The irradiation amount was 240 mJ / cm ² .

(Preparation of coating solution for layer (B) (low refractive index layer))
(Synthesis of perfluoroolefin copolymer (1))

Into an autoclave with a stirrer made of stainless steel having an internal volume of 100 ml, 40 ml of ethyl acetate, 14.7 g of hydroxyethyl vinyl ether and 0.55 g of dilauroyl peroxide were charged, and the inside of the system was deaerated and replaced with nitrogen gas. Further, 25 g of hexafluoropropylene (HFP) was introduced into the autoclave and the temperature was raised to 65 ° C. The pressure when the temperature in the autoclave reached 65 ° C. was 0.53 MPa (5.4 kg / cm ² ). The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 0.31 MPa (3.2 kg / cm ² ), the heating was stopped and the mixture was allowed to cool. When the internal temperature dropped to room temperature, unreacted monomers were driven out, the autoclave was opened, and the reaction solution was taken out. The obtained reaction solution was poured into a large excess of hexane, and the polymer was precipitated by removing the solvent by decantation. Further, this polymer was dissolved in a small amount of ethyl acetate and reprecipitated twice from hexane to completely remove the residual monomer. After drying, 28 g of polymer was obtained. Next, 20 g of the polymer was dissolved in 100 ml of N, N-dimethylacetamide, and 11.4 g of acrylic acid chloride was added dropwise under ice cooling, followed by stirring at room temperature for 10 hours. Ethyl acetate was added to the reaction solution, washed with water, the organic layer was extracted and concentrated, and the resulting polymer was reprecipitated with hexane to obtain 19 g of perfluoroolefin copolymer (1). The resulting polymer had a refractive index of 1.422.

(Preparation of hollow silica particle dispersion)
Hollow silica particle fine particle sol (isopropyl alcohol silica sol, CS60-IPA manufactured by Catalyst Chemical Industry Co., Ltd., average particle diameter 60 nm, shell thickness 10 nm, silica concentration 20% by mass, silica particle refractive index 1.31) in 500 parts by mass, After adding 30 parts by mass of acryloyloxypropyltrimethoxysilane and 1.51 parts by mass of diisopropoxyaluminum ethyl acetate, 9 parts by mass of ion-exchanged water was added. After making it react at 60 degreeC for 8 hours, it cooled to room temperature and added 1.8 mass parts of acetylacetone, and obtained the dispersion liquid. Then, while adding cyclohexanone so that the silica content was almost constant, solvent substitution was performed by distillation under reduced pressure at a pressure of 30 Torr, and finally a dispersion S having a solid content concentration of 18.2% by mass was obtained by adjusting the concentration. . When the amount of IPA remaining in the obtained dispersion was analyzed by gas chromatography, it was 0.5% or less.

Each component was mixed as described below and dissolved in MEK to prepare a low refractive index layer coating solution (B-1) having a solid content of 5% by mass.
Composition of low refractive index layer coating liquid (B-1) Perfluoroolefin copolymer (1) 15 parts by mass DPHA (mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.) 7 Mass part Defender MCF-323 (fluorine-based surfactant, manufactured by Dainippon Ink & Chemicals, Inc.)
5 parts by mass Fluorine-containing polymerizable compound M-1 20 parts by mass Hollow silica particle dispersion S (solid content concentration 18.2% by mass) 50 parts by mass Irgacure 127 (photopolymerization initiator, manufactured by Ciba Specialty Chemicals Co., Ltd.) )
3 parts by mass

(Formation of a low refractive index layer)
On the antistatic layer (A-1), a low refractive index layer coating solution (B-1) was applied using a gravure coater. After drying at 90 ° C. for 30 seconds, it was cured by ultraviolet irradiation. The ultraviolet curing conditions were such that the nitrogen concentration was purged so that the oxygen concentration was 0.1 vol% or less, and an illuminance of 600 mW / cm ² using a 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) The irradiation amount was 600 mJ / cm ² .

As described above, an antireflection film (F-1) in which a hard coat layer, an antistatic layer, and a low refractive index layer were laminated in this order on a transparent support was produced. The refractive index of each layer was measured by applying a coating solution for each layer on a glass plate so as to have a thickness of about 4 μm, and measuring with a multiwavelength Abbe refractometer DR-M2 (manufactured by Atago Co., Ltd.). The refractive index measured using the “DR-M2, M4 interference filter 546 (e) nm part number: RE-3523” filter was employed as the refractive index at a wavelength of 550 nm.
The film thickness of each layer was calculated using a reflection spectral film thickness meter “FE-3000” (manufactured by Otsuka Electronics Co., Ltd.) after each layer was laminated. The value derived from the Abbe refractometer was used as the refractive index of each layer in the calculation.
Table 2 shows the refractive index and optical film thickness of each layer thus obtained.

<Example 2>
(Preparation of coating solution for antistatic layer)
Phosphorus-containing tin oxide particles (Catalyst Kasei Kogyo Co., Ltd., ELCOM TL-30S, primary particle size 10-30 nm), Dispersant (Asahi Denka Kogyo Co., Ltd., Adeka Pluronic TR-702), and propylene glycol monomethyl ether (PGME) was mixed in a blending amount of 28.5 / 1.5 / 70.0 (mass ratio) (total solid content 30% by mass, total inorganic content 28.5%). Using a media disperser (using zirconia beads having a diameter of 0.1 mm), phosphorus-containing tin oxide (PTO) particles were dispersed to prepare a PTO dispersion.
In a container shielded from ultraviolet rays, 25 parts by mass of the PTO particle dispersion, 4 parts by mass of a fluorine-containing polymerizable compound (compound M-1, fluorine content 45%, molecular weight 224 between crosslinks), photopolymerization initiator (Ciba -Antistatic layer coating solution (A-2) by stirring 0.150 parts by mass of Specialty Chemicals Co., Ltd., Irgacure 184) and 70.9 parts by mass of propylene glycol monomethyl ether (PGME) at 50 ° C for 2 hours Got.

(Preparation of antireflection film)
A hard coat layer, an antistatic layer, and a low refractive index layer are laminated in this order on the transparent support in the same manner as in Example 1 except that (A-2) is used as the coating solution for the antistatic layer. An antireflection film (F-2) was prepared. Table 2 shows the refractive index and optical film thickness of each layer.

<Example 3>
In a container shielded from ultraviolet rays, 25.5 parts by mass of the PTO particle dispersion of Example 2 above, fluorine-containing polymerizable compound (compound X-35, fluorine content 53%, cross-linking molecular weight 406) 3.5 masses Parts, a photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd., Irgacure 184) 0.1 parts by mass and PGME 70.9 parts by mass at 50 ° C. for 2 hours to stir the antistatic layer coating solution (A-3 )
A hard coat layer, an antistatic layer, and a low refractive index layer are laminated in this order on the transparent support in the same manner as in Example 1 except that (A-3) is used as the antistatic layer coating solution. An antireflection film (F-3) was prepared. Table 2 shows the refractive index and optical film thickness of each layer.

<Example 4>
Using the above (A-2) as the coating solution for the antistatic layer, the hard coat layer, the antistatic layer, and the low refractive index were formed on the transparent support in the same manner as in Example 2 except that the film thickness was changed. An antireflection film (F-4) in which the layers were laminated in this order was produced. Table 2 shows the refractive index and optical film thickness of each layer.

<Comparative Example 1>
In a container shielded from ultraviolet rays, 25 parts by mass of the PTO particle dispersion liquid of Example 2 above, 4 parts by mass of DPHA (fluorine content 0%), photopolymerization initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., Irgacure 184) ) 0.1 parts by mass and 70.9 parts by mass of PGME were stirred at 50 ° C. for 2 hours to obtain an antistatic layer coating solution (AH-1).
A hard coat layer, an antistatic layer, and a low refractive index layer were laminated in this order on the transparent support in the same manner as in Example 1 except that the above (AH-1) was used as the antistatic layer coating solution. An antireflection film (FH-1) was prepared. Table 2 shows the refractive index and optical film thickness of each layer.

<Comparative Example 2>
In a container shielded from ultraviolet rays, 20 parts by mass of the PTO particle dispersion of Example 2 above, 12 parts by mass of DPHA (fluorine content 0%), a photopolymerization initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., Irgacure 184) ) 0.3 parts by mass and 67.7 parts by mass of PGME were stirred at 50 ° C. for 2 hours to obtain an antistatic layer coating solution (AH-2).
A hard coat layer, an antistatic layer, and a low refractive index layer are laminated in this order on the transparent support in the same manner as in Example 1 except that (AH-2) is used as the coating solution for the antistatic layer. An antireflection film (FH-2) was prepared. Table 2 shows the refractive index and optical film thickness of each layer.

<Comparative Example 3>
Zirconium oxide (ZrO ₂ ) fine particle-containing hard coating agent (Desolite Z7404 [refractive index 1.72, solid content concentration: 60 mass%, zirconium oxide fine particle content: 70 mass% (based on solid content), average particle diameter of zirconium oxide fine particles : About 20 nm, solvent composition: MIBK / MEK = 9/1, manufactured by JSR Corporation]) 4 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA), start of photopolymerization 0.1 parts by weight of the agent (Irgacure 907, manufactured by Ciba Specialty Chemicals Co., Ltd.), 66.0 parts by weight of MEK, 5.9 parts by weight of MIBK, and 20.0 parts by weight of cyclohexanone were added and stirred, and the coating solution (AH -3) was prepared.
A hard coat layer, a ZrO ₂ -containing layer, and a low refractive index layer were formed in this order on the transparent support in the same manner as in Example 1 except that (AH-3) was used as the coating solution for the antistatic layer. A laminated antireflection film (FH-3) was produced. Table 2 shows the refractive index and optical film thickness of each layer.

<Comparative example 4>
(Preparation of antistatic layer coating solution)
An organosilicon compound polymer comprising an oligomer obtained by hydrolyzing an organosilicon compound comprising tetraethoxysilane was obtained. 5 parts by mass of this organosilicon compound polymer and 5 parts by mass of ATO particles having a primary particle system of 8 nm were mixed to prepare a coating solution (AH-4).
(Preparation of coating solution for low refractive index layer)
An organosilicon compound obtained by hydrolyzing an organosilicon compound composed of tetraethoxysilane and an organosilicon compound having a fluoroalkyl group (1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane) 5 parts by mass of this polymer and 5 parts by mass of low refractive index silica fine particles were mixed to prepare a coating solution (BH-1) for a low refractive index layer.
(Preparation of antireflection film)
On the hard coat layer produced in the same manner as in Example 1, an antistatic layer coating solution (AH-4) was applied and dried by heating to form an antistatic layer. Then, the low refractive index layer was formed by apply | coating the coating liquid (BH-1) for low refractive index layers on an antistatic layer, and making it heat-dry. Table 2 shows the refractive index and optical film thickness of each layer.

<Comparative Example 5>
In a container shielded from ultraviolet rays, 25 parts by mass of the PTO particle dispersion of Example 2 above, 4 parts by mass of the following fluorinated polymerizable compound (fluorine content 48%, molecular weight between crosslinks 580), photopolymerization initiator (Ciba -Specialty Chemicals Co., Ltd. product, Irgacure 184) 0.1 mass part and PGME70.9 mass part were stirred at 50 degreeC for 2 hours, and the antistatic layer coating liquid (AH-5) was obtained.

  A hard coat layer, an antistatic layer, and a low refractive index layer are laminated in this order on the transparent support in the same manner as in Example 1 except that (AH-5) is used as the coating solution for the antistatic layer. An antireflection film (FH-5) was prepared. Table 2 shows the refractive index and optical film thickness of each layer.

(Evaluation of antireflection film)
Various characteristics of the antireflection film were evaluated by the following methods. The results are shown in Table 2.

(1) Specular reflectance and tint A spectrophotometer V-550 (manufactured by JASCO Corporation) is equipped with an adapter ARV-474, and in the wavelength region of 380 to 780 nm, the emission angle is 5 degrees at an incident angle of 5 degrees. The specular reflectance was measured, the average reflectance of 450 to 650 nm was calculated, and the antireflection property was evaluated. Further, the CIE 1976 L ^* a ^* b ^* color space a ^* value and b ^* value representing the color of the specularly reflected light with respect to the 5-degree incident light of the CIE standard light source D65 are calculated from the measured reflection spectrum, and the reflected light The color was evaluated.
Further, by visually observing the reflected light of the fluorescent lamp, a case where remarkable coloring was recognized was rated as x, a case where coloring was perceived to an acceptable level was marked as ◯, and a coloring where almost no coloring was felt was marked as ◎.

(2) Measurement of surface resistance value After placing the sample under the conditions of 25 ° C. and 60% RH for 2 hours, the surface resistance value was measured by the circular electrode method under the same conditions.

(3) Adherence to dust The transparent support side of the antireflection film is attached to the CRT surface, and used for 24 hours in a room having 1 to ² million pieces of dust and tissue paper waste of 0.5 μm or more per 1 ft ³ (legislation foot). did. The number of adhering dust and tissue paper waste per 100 cm ^{2 of the} antireflection film is measured, and the average value of each result is less than 50, the case of 50 to 199 is ○, the case of 200 to 500 Was evaluated as x, and more than that as xx.

(4) Adhesion evaluation On the surface of the antireflective film having the low refractive index layer, a vertical and eleven horizontal cuts were made with a cutter knife in a grid pattern, and a total of 100 square squares were carved. A polyester adhesive tape “NO.31B” manufactured by Nitto Denko Corporation was pressed and the adhesion test was repeated three times at the same place. The presence or absence of peeling was visually observed. When the number of peeled ridges was zero, ◯, five or less were △, and more than five were marked with ×.

(5) Evaluation of scratch resistance By using a rubbing tester and performing a steel wool rubbing test under the following conditions, it can be used as an index of scratch resistance.
Evaluation environmental conditions: 25 ° C., 60% RH
Rub: Steel wool (manufactured by Nippon Steel Wool Co., Ltd., gelled No. 0000)
The band is fixed by winding it around the rubbing tip (1 cm × 1 cm) of the tester that comes into contact with the sample.
Travel distance (one way): 13cm
Rubbing speed: 13 cm / second,
Load: 500 g / cm ²
Tip contact area: 1 cm × 1 cm,
Number of rubbing: 10 round trips.

An oil-based black ink was applied to the back side of the rubbed sample and visually observed with reflected light, and scratches on the rubbed portion were evaluated according to the following criteria.
◎: Even when viewed very carefully, no scratches are visible. ○: When viewed very carefully, slightly weak scratches are visible.
×: Scratches can be seen without looking carefully.

In Table 2, the “refractive index difference from the hard coat layer” refers to the refractive index (n _A ) of the antistatic layer ( _A ) and the refractive index (n _HC ) of the hard coat layer {(n _A −n _HC ) / N _HC } × 100.
As shown in Table 2, it can be seen that the antireflection film of the present invention has a low reflectance, a reflection hue close to colorless, and is further excellent in dust adhesion and adhesion.

(Preparation of polarizing plate)
80 μm-thick triacetylcellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.), which was saponified by immersing in an aqueous solution of NaOH at 1.5 mol / L and 55 ° C. for 2 minutes, neutralizing and washing with water. A polarizing plate was prepared by adhering and protecting both sides of a polarizer prepared by adsorbing iodine to polyvinyl alcohol with the antireflection films of Examples and Comparative Examples that were saponified in the same manner.

(Production of liquid crystal display device)
Polarized light in which the polarizing plate and the retardation film provided in the VA liquid crystal display device (LC-37GS10, manufactured by Sharp Corporation) were peeled off, and the polarizing plate produced above was attached to the product instead. It stuck so that it might correspond with a board, and the liquid crystal display device which has the antireflection film of an Example and a comparative example was produced. In addition, it affixed so that an antireflection film might become a visual recognition side.

  The polarizing plate with an antireflection film and the image display device of Examples prepared as described above are excellent in antireflection properties, dust resistance, and anti-resistance properties as compared with Comparative Examples, as in the case of the antireflection film attached thereto. Abrasion and adhesion were shown.

Claims (13)

An antireflection film having at least a layer (A) and a layer (B) in this order on a transparent support,
The layer (A) is (a1) represented by the following general formula (1), contains 35% by mass or more of fluorine, and all fluorine-containing polymerizable compounds having a calculated value of molecular weight between crosslinks smaller than 500; a2) a conductive material and a layer formed from a composition containing
The layer (B) is a low refractive index layer having a lower refractive index than the layer (A),
An antireflection film having a surface resistivity of 1 × 10 ¹² Ω / □ or less.
General formula (1): Rf {-(L) _m- Y} _n
(In the formula, Rf represents an n-valent group containing a carbon atom and a fluorine atom. N represents an integer of 3 or more. L represents a divalent linking group, m represents 0 or 1. Y represents polymerization. Represents a sex group.)   The antireflection film according to claim 1, further comprising a hard coat layer in contact with the layer (A) between the transparent support and the layer (A). The antireflection film according to claim 2 refractive index (n _A) and the refractive index of the hard coat layer (n _HC) is characterized by satisfying the following formula (1) of the layer (A).
Formula (1): 0 ≦ | (n _A −n _HC ) / n _HC | ≦ 0.05   The refractive index of the said layer (B) is 1.33-1.40 in wavelength 550nm, The antireflection film in any one of Claims 1-3 characterized by the above-mentioned.   The optical film thickness (nd) of the said layer (B) is 100 nm-200 nm, The antireflection film in any one of Claims 1-4 characterized by the above-mentioned.   The conductive material is tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), phosphorus-doped tin oxide (PTO), zinc antimonate, indium-doped zinc oxide (IZO), The reflection according to any one of claims 1 to 5, which is at least one metal oxide selected from the group consisting of zinc oxide, ruthenium oxide, rhenium oxide, silver oxide, nickel oxide and copper oxide. Prevention film.   The antireflection film according to claim 1, wherein the (a1) fluorine-containing polymerizable compound contains 40% by mass or more of fluorine.   The antireflection film according to any one of claims 1 to 7, wherein the calculated value of all cross-linking molecular weights of the (a1) fluorine-containing polymerizable compound is larger than 50 and smaller than 300.   The layer (A) contains the conductive material (a2) in an amount of 40% by mass to 80% by mass with respect to the total solid content of the layer (A). The antireflection film as described.   The refractive index of the said layer (A) is 1.50-1.60 in wavelength 550nm, The antireflection film in any one of Claims 1-9 characterized by the above-mentioned.   11. The antireflection film according to claim 1, wherein the optical thickness (nd) of the layer (A) is 200 nm to 300 nm at a wavelength of 550 nm.   It is a polarizing plate which has two protective films which protect both surfaces of a polarizing film and this polarizing film, Comprising: At least 1 piece of this protective film is an antireflection film in any one of Claims 1-11 A characteristic polarizing plate.   An image display device comprising the antireflection film according to claim 1 or the polarizing plate according to claim 12 on an outermost surface of the display.