JP4866811B2 - Antireflection film - Google Patents

Description

  The present invention relates to an antireflection film, and in particular, there is no occurrence of cracks in the hard coat layer after ultraviolet irradiation, excellent coating film adhesion with the base film, minimum reflectance is small, transparency, The present invention relates to an antireflection film which is excellent in steel wool resistance, antistatic property, curling property and alkali resistance and has no interference fringes.

  A display such as a personal computer, a television, a car navigator, or a mobile phone is one in which a person views an image and reads information, and visibility is required as an important function. However, in reality, there are many situations in which the contrast due to the reflection of the background decreases and the screen becomes difficult to see. In order to prevent this, a device for suppressing the surface reflection of the screen, which causes a reduction in visibility, is made, and the display surface is subjected to an antiglare treatment or an antireflection treatment.

The anti-glare process is a process of forming fine irregularities on the surface of the display and scatter the reflected image by scattering light to blur the outline. When the substrate is plastic, inorganic fine particles such as silica and organic fine particles such as polystyrene are coated on the surface, but the resolution of the image is lowered. In the antireflection treatment, a thin film having a thickness of about the wavelength of light is formed on the surface, and the reflectance is reduced by the light interference effect. When the refractive index of the incident medium is n ₁ , the refractive index of the film is n ₂ , and the reflectance is R,
R = [(n ₂ −n ₁ ) / (n ₂ + n ₁ )] ²
Where d is the film thickness and λ is the wavelength of the light.
d = λ / (4n ₂ )
In this case, the light interference effect is maximized.

  As a method for forming a thin film, there are a dry method and a wet method. In the dry method, a high refractive index layer such as titanium dioxide and a low refractive index layer such as magnesium fluoride or silica are formed by vacuum deposition or sputtering. It takes time and is difficult to continue.

As for the wet method, for example, it includes a base material and a hard coat film formed on the base material, and the hard coat film includes a matrix component and antimony pentoxide (Sb ₂ O ₅ ) particles, and the pentoxide A base material with a hard coat film, wherein the average particle diameter of the antimony particles is in the range of 2 to 100 nm, and the content of the antimony pentoxide particles in the hard coat layer is in the range of 5 to 95% by weight; and An antireflection film is further formed on the hard coat film, and a substrate with a hard coat film is disclosed (for example, see Patent Document 1). However, the hard coat layer composed of the components described in Patent Document 1 has a problem that cracks occur in the hard coat film after ultraviolet irradiation. Further, there is a problem that the adhesion between the base film and the hard coat film is not sufficient. Furthermore, the base material with a hard coat film has room for improvement in properties such as curling property, chemical resistance and interference fringes.
JP 2004-50810 A

  An object of the present invention is an antireflection film having a structure in which a hard refractive index layer also has a role of a high refractive index layer and a low refractive index layer provided on the hard coating layer, and the hard coating layer after ultraviolet irradiation is cracked. No anti-reflection film with no interference fringes, no adhesion, excellent adhesion to the base film, low minimum reflectivity, transparency, steel wool resistance, antistatic, curl and alkali resistance It is to provide.

  As a result of intensive studies to solve the above problems, the present inventors have found that a hard coat layer and a low refractive index layer having a specific thickness and material structure are formed on a base film made of biaxially oriented polyethylene terephthalate. It has been found that the above-mentioned problems can be solved by sequentially providing the above, and the present invention has been completed based on this finding.

That is, the present invention is as follows.
(1) An antireflection film having a hard coat layer on a base film made of biaxially stretched polyethylene terephthalate, and further having a low refractive index layer on the hard coat layer,
The hard coat layer has a thickness of 0.5 to 5 μm;
100 mass of ionizing radiation curable resin in which the hard coat layer is composed of 80 to 97 mass% of polyfunctional (meth) acrylate having 2 or more (meth) acryloyl groups in the molecule and 20 to 3 mass% of N-vinylcaprolactam. Antireflective film characterized by being formed by blending 200 to 600 parts by mass of antimony pentoxide in a part and curing it.
(2) The antireflection film as described in (1) above, wherein the polyfunctional (meth) acrylate having two or more (meth) acryloyl groups in the molecule is dipentaerythritol hexaacrylate.
(3) The antireflection film as described in (1) above, wherein the antimony pentoxide has an average particle size of 5 to 100 nm.
(4) A matrix component whose main component is a disilane compound having a divalent organic group containing one or more fluorine atoms or a (partial) hydrolyzate thereof; hollow silica particles; and radical polymerization Formed from a composition for forming a low refractive index layer containing a graft copolymer having a repeating unit formed using a polymerizable monomer as a trunk and a silicone as a branch,
The composition for forming a low refractive index layer is formed by blending 20 to 120 parts by mass of the hollow silica particles and 5 to 40 parts by mass of the graft copolymer with respect to 100 parts by mass of the matrix component. The antireflection film as described in (4) above.
(5) The disilane compound is represented by the following formula (1)
^{_{X m R 1 3-m Si}} -Y-SiR 1 3-m X m (1)
Wherein R ¹ is a monovalent hydrocarbon group having 1 to 6 carbon atoms, Y is a divalent organic group containing one or more fluorine atoms, X is a hydrolyzable group, m is 1, 2 or 3. is there.)
The antireflection film as described in (4) above, wherein
(6) The antireflection film as described in (4) above, wherein the hollow silica particles have an average particle diameter of 5 to 100 nm.
(7) The antireflection film as described in (4) above, wherein the trunk portion composed of repeating units formed using the radical polymerizable monomer is an acrylic polymer.

In an antireflection film that has a structure in which a hard refractive index layer is provided on a hard coat layer and a low refractive index layer is provided thereon, a large amount of antimony pentoxide is used to increase the refractive index of the hard coat layer. There were problems that cracks occurred in the hard coat layer after ultraviolet irradiation, and that the adhesion of the coating film to the base film deteriorated. Therefore, in the present invention, the hard coat layer has a specific thickness, and N-vinylcaprolactam is used as a part of the constituent components of the matrix component (ionizing radiation curable resin) of the hard coat layer. Could be solved. Furthermore, according to the configuration of the present invention, in addition to the above effects, the effect of improving the minimum reflectance, transparency, steel wool resistance, antistatic properties, curling properties, and alkali resistance, and also preventing the occurrence of interference fringes. Is recognized.
That is, according to the present invention, there is no occurrence of cracks in the hard coat layer after ultraviolet irradiation, excellent coating film adhesion with the base film, low minimum reflectance, transparency, steel wool resistance, antistatic properties Further, an antireflection film having excellent curling properties and alkali resistance and having no interference fringes is provided.

Hereinafter, the present invention will be described in more detail.
(Base film)
The base film used in the present invention is made of biaxially stretched polyethylene terephthalate having transparency. A biaxially stretched polyethylene terephthalate film is preferably used because of its good mechanical strength and dimensional stability.
The refractive index of the base film is usually 1.64 to 1.66. In addition, the refractive index as used in the field of this invention is the value measured using the Abbe refractometer according to JISK7142. Moreover, the thickness of a base film is 20-250 micrometers, for example.

(Hard coat layer)
The hard coat layer in the present invention must satisfy the following requirements (1) and (2).
(1) The thickness is 0.5-5 μm.
If thickness is less than 0.5 micrometer, pencil hardness will fall and steel wool resistance will also fall. When the thickness exceeds 5 μm, the interference fringe prevention effect is not exhibited. A preferred thickness is 0.8 to 4.0 μm, and a more preferred thickness is 1.2 to 3.0 μm.

  (2) To 100 parts by mass of ionizing radiation curable resin comprising 80 to 97% by mass of polyfunctional (meth) acrylate having 2 or more (meth) acryloyl groups in the molecule and 20 to 3% by mass of N-vinylcaprolactam, It is formed by blending 200 to 600 parts by mass of antimony pentoxide and curing it.

  As polyfunctional (meth) acrylate having two or more (meth) acryloyl groups in the molecule, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, di Examples include pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol di (meth) acrylate, trimethylolpropane di (meth) acrylate, and epoxy acrylate. Preferable examples include pentaerythritol triacrylate, dipentaerythritol hexa (meth) acrylate, and dipentaerythritol pentaacrylate. Among them, dipentaerythritol hexa (meth) acrylate is particularly preferable. These polyfunctional (meth) acrylates may be used alone or in combination of two or more.

The ionizing radiation curable resin used in the present invention comprises 85 to 95% by mass of polyfunctional (meth) acrylate having two or more (meth) acryloyl groups in the molecule and 15 to 5% by mass of N-vinylcaprolactam. Is more preferable.
In addition, when the ratio of N-vinylcaprolactam is less than 3% by mass, cracks are generated in the hard coat layer after ultraviolet irradiation, and the coating film adhesion to the base film and curl properties are inferior. On the contrary, when the proportion of N-vinylcaprolactam exceeds 20% by mass, the steel wool resistance deteriorates.

Antimony pentoxide preferably has an average particle size of 5 to 100 nm. By having this average particle diameter, transparency is enhanced.
A more preferable average particle size is 10 to 70 nm, and a particularly preferable average particle size is 15 to 50 nm.
Antimony pentoxide preferably has a pyrochlore structure. What has such a pyrochlore structure has the property that the electroconductivity by proton conduction is high. The pyrochlore structure is an octahedron formed of six oxygen atoms and OH groups centered on antimony atoms, as described in Journal of Chemical Society of Japan, No. 4, P. 488, 1983. A skeleton structure formed by sharing the vertices of these octahedrons.

The hard coat layer in the present invention is an ionizing radiation curable resin 100 comprising 80 to 97% by mass of the polyfunctional (meth) acrylate having two or more (meth) acryloyl groups and 20 to 3% by mass of N-vinylcaprolactam. It is formed using the composition which mix | blended 200-600 mass parts of antimony pentoxides with the mass part. When the mixing ratio of antimony pentoxide is less than 200 parts by mass, the effect of reducing interference fringes and the effect of reducing the minimum reflectance are not exhibited. On the contrary, if the blending ratio of antimony pentoxide exceeds 600 parts by mass, cracks occur in the hard coat layer after ultraviolet irradiation, and the effect of reducing interference fringes does not appear.
A more preferable blending ratio is 250 to 500 parts by mass of antimony pentoxide with respect to 100 parts by mass of the ionizing radiation curable resin.

  Further, in the hard coat layer in the present invention, when the inorganic compound fine particles are non-conductive substances such as titanium dioxide and zirconia, in order to impart conductivity to the hard coat layer and prevent adhesion of dust or the like to the surface, Polythiophene or polyaniline can also be added. The addition amount of polythiophene or polyaniline is 5 to 50 parts by mass, preferably 10 to 40 parts by mass with respect to 100 parts by mass of the ionizing radiation curable resin.

  A hard-coat layer can be formed by apply | coating the said composition as a coating material on a base film, drying, and making it harden | cure by ionizing radiation irradiation. There is no particular limitation on the ionizing radiation, and examples thereof include an electron beam, radiation, and ultraviolet rays. Among ionizing radiations, ultraviolet rays are particularly suitable because they are simple in equipment and easy to handle. By irradiating with ionizing radiation and crosslinking, a coating film having a pencil hardness of H or higher as defined in JIS K 5400 can be formed.

  When the ionizing radiation is ultraviolet, a photopolymerization initiator is usually added. There is no restriction | limiting in particular as a photoinitiator, For example, Irgacure 184,907,651,1700,1800,819,369 (made by Ciba Specialty Chemicals), Darocur 1173 (made by Ciba Specialty Chemicals), Ezacure KIP150, TZT (made by Nippon Shibel Hegner), Lucyrin TPO (made by BASF), Kayacure BMS (made by Nippon Kayaku), etc. are mentioned.

  Of course, the composition can be used in combination with various additives as required.

  The obtained hard coat layer preferably has a refractive index that is the same as or very close to that of a base film made of biaxially stretched polyethylene terephthalate. By setting the refractive indexes of the two in this way, the interference fringe prevention effect is further improved as described above.

(Easily adhesive layer)
In the antireflection film of the present invention, an easy-adhesive layer may be provided between the base film and the hard coat layer for the purpose of improving the adhesion between them.
The material of the easy-adhesive layer is not particularly limited as long as it is transparent and improves the adhesion between the base film and the hard coat layer. For example, an acrylic resin, a polyester resin, a urethane resin and their co-polymer Examples include coalescence. Although the thickness of an easily adhesive layer is not specifically limited, 0.03-0.30 micrometer is preferable and 0.05-0.20 micrometer is more preferable. The easy adhesive layer can be provided on the base film by a known coating technique.

(Low refractive index layer)
The low refractive index layer in the present invention is not particularly limited, and a known low refractive index layer can be appropriately employed. For example, a layer formed by coating fine particles, such as polysiloxane, hollow silica, magnesium fluoride, and fluororesin, which are low refractive index materials, in a matrix component that can form a low refractive index layer, to form a paint. However, in the present invention, the following low refractive index layer is particularly preferable from the viewpoints of minimum reflectance, alkali resistance, and coating property.

A preferred low refractive index layer in the present invention is a matrix component mainly composed of a disilane compound having a divalent organic group containing one or more fluorine atoms or a (partial) hydrolyzate thereof; hollow silica particles; and radicals It is formed from a composition for forming a low refractive index layer containing a graft copolymer having a repeating unit formed using a polymerizable monomer as a trunk and a silicone as a branch.
In the present invention, the (partial) hydrolyzate indicates that it may be a partial hydrolyzate or a complete hydrolyzate. The main component in the matrix component means that it is contained in an active ingredient excluding the solvent in a proportion of 50% by mass or more, particularly 70% by mass or more.

The matrix component is mainly composed of a disilane compound having a divalent organic group containing at least one fluorine atom or a (partial) hydrolyzate thereof.
The disilane compound has the following formula (1)
^{_{X m R 1 3-m Si}} -Y-SiR 1 3-m X m (1)
Wherein R ¹ is a monovalent hydrocarbon group having 1 to 6 carbon atoms, Y is a divalent organic group containing one or more fluorine atoms, X is a hydrolyzable group, and m is 1, 2 or 3. .)
Or a (partial) hydrolyzate thereof (hereinafter also referred to as component (i)).

Here, Y represents a divalent organic group containing 1 or more, preferably 4 to 50, particularly preferably 8 to 24, fluorine atoms. Specific examples thereof include the following. However, the present invention is not limited to this.
_{-C 2 H 4 - (CF 2} ) n -C 2 H 4 -
_{-C 2 H 4 -CF (CF 3} ) - (CF 2) n -CF (CF 3) -C 2 H 4 -
_{-C 2 H 4 -CF (C 2} F 5) - (CF 2) n -CF (C 2 F 5) -C 2 H 4 -
_{-C 2 H 4 -CF (CF 3} ) CF 2 -O (CF 2) n O-CF 2 CF (CF 3) -C 2 H 4 -
(However, n is 2-20.)
_{-C 2 H 4 -C 6 F 10} -C 2 H 4 -
_{-C 2 H 4 -C 6 F 4} -C 2 H 4 -

In order to express various functions such as antifouling properties and water repellency in addition to antireflection properties, it is preferable to contain a large amount of fluorine atoms. In addition, since the perfluoroalkylene group is rigid, it is preferable to contain as many fluorine atoms as possible for the purpose of obtaining a film having high hardness and high scratch resistance. If it contains a large amount of fluorine atoms, the alkali resistance is improved. Therefore, Y represents the following structure: —CH ₂ CH ₂ (CF ₂ ) _n CH ₂ CH ₂ —
_{-C 2 H 4 -CF (CF 3} ) - (CF 2) n -CF (CF 3) -C 2 H 4 -
(However, n is 2-20.)
In particular, —CH ₂ CH ₂ (CF ₂ ) _n CH ₂ CH ₂ — (n = 2 to 20)
Is preferred.

  Although it is necessary to satisfy | fill the value of 2-20 as n, More preferably, it is good to satisfy | fill the range of 4-12, Most preferably, 4-10. If it is less than this, various functions such as antireflection, alkali resistance, stain resistance and water repellency may not be obtained sufficiently, and if it is too much, sufficient crosslinking resistance will be obtained because the crosslink density will decrease. There are cases where it is not possible.

R ¹ represents a monovalent hydrocarbon group having 1 to 6 carbon atoms. Specifically, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, and a cyclohexyl group, a phenyl group, and the like can be exemplified. A methyl group is preferred for obtaining good scratch resistance.

  m is 1, 2 or 3, preferably 2 or 3, and in order to obtain a particularly hard film, m = 3 is preferable.

X represents a hydrolyzable group. Specific examples include halogen atoms such as Cl, organooxy groups represented by OR ² (R ² is a monovalent hydrocarbon group having 1 to 6 carbon atoms), particularly methoxy group, ethoxy group, propoxy group, isopropoxy group, Examples include alkoxy groups such as butoxy groups, alkenoxy groups such as isopropenoxy groups, acyloxy groups such as acetoxy groups, ketoxime groups such as methylethyl ketoxime groups, and alkoxyalkoxy groups such as methoxyethoxy groups. Among these, an alkoxy group is preferable, and a silane compound having a methoxy group or an ethoxy group is particularly preferable because it is easy to handle and the reaction during hydrolysis is easily controlled.

Specific examples of the disilane compound satisfying the above include the following.
_{(CH 3 O) 3 Si-} C 2 H 4 - (CF 2) 4 -C 2 H 4 -Si (OCH 3) 3
_{(CH 3 O) 3 Si-} C 2 H 4 - (CF 2) 6 -C 2 H 4 -Si (OCH 3) 3
_{(CH 3 O) 3 Si-} C 2 H 4 - (CF 2) 8 -C 2 H 4 -Si (OCH 3) 3
_{(CH 3 O) 3 Si-} C 2 H 4 - (CF 2) 10 -C 2 H 4 -Si (OCH 3) 3
_{(CH 3 O) 3 Si-} C 2 H 4 - (CF 2) 16 -C 2 H 4 -Si (OCH 3) 3
_{(C 2 H 5 O) 3} Si-C 2 H 4 - (CF 2) 4 -C 2 H 4 -Si (OC 2 H 5) 3
_{(C 2 H 5 O) 3} Si-C 2 H 4 - (CF 2) 6 -C 2 H 4 -Si (OC 2 H 5) 3
_{(CH 3 O) 2 (CH} 3) Si-C 2 H 4 - (CF 2) 4 -C 2 H 4 -Si (CH 3) (OCH 3) 2
_{(CH 3 O) 2 (CH} 3) Si-C 2 H 4 - (CF 2) 6 -C 2 H 4 -Si (CH 3) (OCH 3) 2
_{(CH 3 O) (CH 3} ) 2 Si-C 2 H 4 - (CF 2) 4 -C 2 H 4 -Si (CH 3) 2 (OCH 3)
_{(C 2 H 5 O) (} CH 3) 2 Si-C 2 H 4 - (CF 2) 6 -C 2 H 4 -Si (CH 3) 2 (OC 2 H 5)
_{(CH 3 O) 3 Si-} C 2 H 4 -CF (CF 3) - (CF 2) 4 -CF (CF 3) -C 2 H 4 -Si (OCH 3) 3
_{(CH 3 O) 3 Si-} C 2 H 4 -CF (CF 3) - (CF 2) 8 -CF (CF 3) -C 2 H 4 -Si (OCH 3) 3
_{(CH 3 O) 3 Si-} C 2 H 4 -CF (CF 3) - (CF 2) 12 -CF (CF 3) -C 2 H 4 -Si (OCH 3) 3
Among these, preferably,
_{(CH 3 O) 3 Si-} C 2 H 4 - (CF 2) 4 -C 2 H 4 -Si (OCH 3) 3
_{(CH 3 O) 3 Si-} C 2 H 4 - (CF 2) 6 -C 2 H 4 -Si (OCH 3) 3
_{(CH 3 O) 3 Si-} C 2 H 4 - (CF 2) 8 -C 2 H 4 -Si (OCH 3) 3
_{(C 2 H 5 O) 3} Si-C 2 H 4 - (CF 2) 4 -C 2 H 4 -Si (OC 2 H 5) 3
_{(C 2 H 5 O) 3} Si-C 2 H 4 - (CF 2) 6 -C 2 H 4 -Si (OC 2 H 5) 3
These disilane compounds are preferably used.

The disilane compound of the above formula (1) can be used in combination with an organosilicon compound containing a fluorine atom-substituted organic group represented by the following formula (2) or its (partial) hydrolyzate (component (ii)). .
Rf-SiX ₃ (2)
(In the formula, Rf is a monovalent organic group containing one or more fluorine atoms, and X is a hydrolyzable group.)

Here, Rf represents a monovalent organic group containing one or more fluorine atoms, preferably 3 to 25, particularly preferably 3 to 17, and specific examples thereof include the following.
CF ₃ C ₂ H ₄ −
CF ₃ (CF ₂ ) ₃ C ₂ H ₄ −
CF ₃ (CF ₂ ) ₅ C ₂ H ₄ −
CF ₃ (CF ₂ ) ₇ C ₂ H ₄ −
CF ₃ (CF ₂ ) ₉ C ₂ H ₄ −
CF ₃ (CF ₂ ) ₁₁ C ₂ H ₄ −
CF ₃ (CF ₂ ) ₇ CONHC ₃ H ₆ −
CF ₃ (CF ₂ ) ₇ CONHC ₂ H ₄ NHC ₃ H ₆ −
CF ₃ (CF ₂ ) ₇ C ₂ H ₄ OCOC ₂ H ₄ SC ₃ H ₆ −
CF ₃ (CF ₂ ) ₇ C ₂ H ₄ OCONHC ₃ H ₆ −
CF ₃ (CF ₂ ) ₇ SO ₂ NHC ₃ H ₆ −
_{C 3 F 7 O (CF (} CF 3) CF 2 O) p CF (CF 3) CONHC 3 H 6 -
(However, p is p ≧ 1, especially 1 to 3.)
Among these,
CF ₃ C ₂ H ₄ −
CF ₃ (CF ₂ ) ₃ C ₂ H ₄ −
CF ₃ (CF ₂ ) ₇ C ₂ H ₄ −
Is preferable because it does not contain a polar part. X is as described above.

Specific examples of the organosilicon compound containing a fluorine atom-substituted organic group that satisfies the above are exemplified below.
CF ₃ C ₂ H ₄ —Si (OCH ₃ ) ₃
CF ₃ C ₂ H ₄ —Si (OC ₂ H ₅ ) ₃
CF ₃ (CF ₂ ) ₃ C ₂ H ₄ —Si (OCH ₃ ) ₃
CF ₃ (CF ₂ ) ₃ C ₂ H ₄ —Si (OC ₂ H ₅ ) ₃
CF ₃ (CF ₂ ) ₅ C ₂ H ₄ —Si (OCH ₃ ) ₃
CF ₃ (CF ₂ ) ₇ C ₂ H ₄ —Si (OCH ₃ ) ₃
CF ₃ (CF ₂ ) ₇ C ₂ H ₄ —Si (OC ₂ H ₅ ) ₃
CF ₃ (CF ₂ ) ₉ C ₂ H ₄ —Si (OCH ₃ ) ₃
CF ₃ (CF ₂ ) ₁₁ C ₂ H ₄ —Si (OCH ₃ ) ₃
CF ₃ (CF ₂ ) ₇ CONHC ₃ H ₆ —Si (OCH ₃ ) _{3
CF 3 (CF 2) 7 CONHC} 2 H 4 NHC 3 H 6 -Si (OCH 3) 3
CF ₃ (CF ₂ ) ₇ C ₂ H ₄ OCOC ₂ H ₄ SC ₃ H ₆ —Si (OCH ₃ ) ₃
CF ₃ (CF ₂ ) ₇ C ₂ H ₄ OCONHC ₃ H ₆ —Si (OCH ₃ ) ₃
CF ₃ (CF ₂ ) ₇ SO ₂ NHC ₃ H ₆ —Si (OCH ₃ ) _{3
C 3 F 7 O (CF (} CF 3) CF 2 O) p CF (CF 3) CONHC 3 H 6 -Si (OCH 3) 3
(However, p is p ≧ 1.)
Among these, the following are preferable.
CF ₃ C ₂ H ₄ —Si (OCH ₃ ) ₃
CF ₃ (CF ₂ ) ₃ C ₂ H ₄ —Si (OCH ₃ ) ₃
CF ₃ (CF ₂ ) ₇ C ₂ H ₄ —Si (OCH ₃ ) ₃

In the present invention, the component (i) can be used alone without being used in combination with the component (ii). However, when the component (i) and the component (ii) are mixed and used, the component (i) It is necessary that the content be 60% by mass or more and less than 100% by mass. When the content of the component (i) is less than 60% by mass, the crosslinking density is lowered, and good scratch resistance cannot be obtained, so that the function as a protective film becomes insufficient, which is not preferable. More preferably, the content of component (i) is 95% by mass or more. Moreover, it is preferable that the content rate of (i) component is 99.5 mass% or less from the point of the addition effect of (ii) component.
Moreover, in this invention, you may use what cohydrolyzed the mixture of the said (i) component and (ii) component.

  The composition for forming a low refractive index layer in the present invention is mainly composed of component (i), a mixture of component (i) and component (ii), or a co-hydrolyzate thereof, but has an effect on various properties required. In the range not given, the following organosilicon compounds or (partial) hydrolysates thereof can be used.

  Examples of the organosilicon compounds that can be used in combination with the components (i) and (ii) include silicates such as tetraethoxysilane, alkylsilanes such as methyltrimethoxysilane, hexyltrimethoxysilane, and decyltrimethoxysilane, phenyl Silane coupling agents such as phenylsilanes such as trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane And various compounds. In particular, tetraalkoxysilane is effective when used in combination with the purpose of improving scratch resistance because it has the effect of increasing the crosslink density, but it tends to make the coating hydrophilic, alkali resistance, and stain resistance. In addition, since various functions such as water repellency may be deteriorated, it is better to avoid using a large amount, and it is 5 for the total amount of (i) component or (i), (ii) component being 100 parts by mass. It is preferable that the amount is not more than part by weight, particularly not more than 2 parts by weight, particularly not more than 1 part by weight.

The compounds of the above formulas (1) and (2), or the organosilicon compounds that can be used in combination with the above components (i) and (ii) may be used as they are, or (partially) in a hydrolyzed form, or You may use in the form hydrolyzed in the following solvent. From the viewpoint of increasing the curing rate after coating, it is preferable to use the (partly) hydrolyzed form. The amount of water used for the hydrolysis is preferably such that the molar ratio of (H ₂ O / Si—X) is 0.1 to 10.

  For the hydrolysis, a conventionally known method can be applied. As this hydrolysis catalyst or hydrolysis / condensation curing catalyst, acids such as hydrochloric acid, acetic acid, maleic acid, sodium hydroxide (NaOH), ammonia, triethylamine Amine compounds such as dibutylamine, hexylamine, octylamine and dibutylamine, salts of amine compounds, bases such as quaternary ammonium salts such as benzyltriethylammonium chloride and tetramethylammonium hydroxide, potassium fluoride, fluorine Organic compounds such as fluorides such as sodium fluoride, solid acidic catalysts or solid basic catalysts (eg ion exchange resin catalysts), iron-2-ethylhexoate, titanium naphthate, zinc stearate, dibutyltin diacetate Metal salts of carboxylic acids, tetrabutoxy titanium, Organic titanium esters such as la-i-propoxytitanium, dibutoxy- (bis-2,4-pentanedionate) titanium, di-i-propoxy (bis-2,4-pentanedionate) titanium, tetrabutoxyzirconium, tetra Organic zirconium esters such as i-propoxyzirconium, dibutoxy- (bis-2,4-pentanedionate) zirconium, di-i-propoxy (bis-2,4-pentanedionate) zirconium, aluminum triisopropoxide, etc. Alkoxy aluminum compounds, organometallic compounds such as aluminum chelate compounds such as aluminum acetylacetonate complex, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropyl bird Aminoalkyl-substituted alkoxysilanes such as methoxysilane and N- (β-aminoethyl) -γ-aminopropyltriethoxysilane are exemplified, and these may be used alone or in combination.

  The addition amount of this catalyst is 0.01 to 10 parts by mass, preferably 0.1 to 1 part by mass with respect to 100 parts by mass of the (partial) compound to be hydrolyzed. If this amount is less than 0.01 parts by mass, it may take too long to complete the reaction or the reaction may not proceed. Moreover, when it exceeds 10 mass parts, it is disadvantageous in cost, and the obtained composition or hardened | cured material may color, or a side reaction may increase.

  The hollow silica particles are particles having an outer shell layer mainly composed of silica and having a porous or hollow interior. The average particle diameter of the hollow silica particles is preferably 5 to 100 nm, and more preferably 10 to 80 nm. The average particle diameter was determined by a dynamic light scattering method.

  The graft copolymer having a repeating unit formed from a radically polymerizable monomer as a trunk and a silicone as a branch is preferably a comb-shaped acrylic graft copolymer in which the trunk portion composed of the repeating unit is an acrylic polymer. It is a polymer. Examples of the graft copolymer include products obtained by condensing a silicone represented by the following formula (3) and an acrylsilane compound represented by the following formula (4).

(In the formula, R ⁶ and R ^{7 each} represent a monovalent aliphatic hydrocarbon group, phenyl group or monovalent halogenated hydrocarbon group having 1 to 10 carbon atoms. Q is a positive number of 1 or more.)

(Wherein R ⁸ represents a hydrogen atom or a methyl group. R ⁹ represents a methyl group, an ethyl group or a phenyl group, and two R ^{9 s} may be the same or different from each other. Z represents a chlorine atom or a methoxy group. Or represents an ethoxy group.)

The silicone represented by the formula (3) used here can be obtained as a commercial product, and those suitable for the purpose can be used. R ⁶ and R ⁷ in the formula (3) are monovalent aliphatic hydrocarbon groups, phenyl groups or monovalent halogenated hydrocarbons having 1 to 10 carbon atoms, and monovalent fatty acids having 1 to 10 carbon atoms. Examples of the group hydrocarbon group include a methyl group, an ethyl group, and an acyl group. Examples of the monovalent halogenated hydrocarbon include a 3,3,3-trifluoropropyl group and a 4,4,4-tri group. A fluoro-3,3-difluorobutyl group, a 2-chloroethyl group, etc. are mentioned. Particularly preferred as R ⁸ and R ⁹ is a methyl group.

  In the formula (3), q is a positive number of 1 or more, but generally, when a high molecular weight silicone having a number of q of 100 or more is used, the obtained graft copolymer is often oily. . When a low molecular weight silicone having a q number of 100 or less is used, the resulting graft copolymer can be obtained in various forms such as oil, jelly, and solid depending on the type of monomer.

  Next, as the acrylic silane compound represented by the formula (4), for example, γ-methacryloxypropyldimethylchlorosilane, γ-methacryloxypropyldimethylethoxysilane, γ-methacryloxypropyldiphenylchlorosilane, γ-acryloxypropyldimethylchlorosilane, Examples include γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltrichlorosilane, and the like. These acrylic silane compounds can be easily obtained by reacting a silicon compound and a compound having an aliphatic multiple bond in the presence of chloroplatinic acid according to the method described in JP-B-33-9969.

  For radical copolymerization in the production of the graft copolymer, a conventionally known method can be used, and a radiation irradiation method or a method using a radical polymerization initiator can be used. Furthermore, when copolymerizing by the ultraviolet irradiation method, a known sensitizer is used as a radical polymerization initiator, and when copolymerizing by electron beam irradiation, it is not necessary to use a radical polymerization initiator. The radical copolymer thus obtained is a comb-shaped graft copolymer having a repeating unit formed using a radical polymerizable monomer as a trunk and silicone as a branch. In addition, you may use together the monomer containing a hydroxyl group like 2-hydroxyethyl (meth) acrylate as a radically polymerizable monomer.

  Moreover, the graft copolymer in this invention can also utilize a commercial item, for example, Cymac US-150, US-270, US-350, US-450, Reseda GP-700 (above, Toagosei Co., Ltd.) Manufactured).

  As described above, the composition for forming a low refractive index layer in the present invention contains 20 to 120 parts by mass of the hollow silica particles and 5 to 40 parts by mass of the graft copolymer with respect to 100 parts by mass of the matrix component. Do it. When the blending amount of the graft copolymer is 5 parts by mass or more, the alkali resistance improving effect is improved. Moreover, the coating nonuniformity at the time of coating of a low-refractive-index layer can be prevented because it is 40 mass parts or less. A more preferable blending ratio is 40 to 100 parts by mass of hollow silica particles and 10 to 30 parts by mass of the graft copolymer with respect to 100 parts by mass of the matrix component.

  Furthermore, various additives can be blended in the composition for forming a low refractive index layer in the present invention for the purpose of adjusting physical properties such as hardness, scratch resistance, and conductivity of the film.

  Examples of the organic solvent suitable for use in the coating material for forming the low refractive index layer include alcohols such as methanol, isopropyl alcohol, ethylene glycol, butanol and ethylene glycol monopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, Aromatic hydrocarbons such as toluene and xylene, amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone, esters such as ethyl acetate, butyl acetate and γ-butyrolactone, ethers such as tetrahydrofuran and 1,4-dioxane And β-diketones such as acetylacetone and ethyl acetoacetate, and β-ketoesters.

  Examples of the method for coating the hard coat layer surface with the composition for forming a low refractive index layer in the present invention include a dipping method, a spin coat method, a flow coat method, a roll coat method, a spray coat method, a screen printing method, and the like. Although not particularly limited, since the film thickness can be easily controlled, it is preferable to perform the film thickness to a predetermined thickness by the dipping method, the spray coating method, and the roll coating method. After application, a cured film can be formed by heating or the like.

  The refractive index of the low refractive index layer is preferably 1.28 to 1.50, more preferably 1.30 to 1.45. The thickness of the low refractive index layer is preferably 40 to 300 nm, and more preferably 60 to 150 nm.

The antireflection film of the present invention preferably has a total light transmittance of 90% or more, and more preferably 92% or more. The total light transmittance can be measured according to JIS K 7361-1. When the total light transmittance is less than 90%, the transparency is slightly inferior, and when used as an antireflection film for a display, the image sharpness may be lowered.
The antireflection film of the present invention has a surface resistivity of 1.0 × 10 ¹² Ω / sq. Or less, preferably 1.0 × 10 ¹⁰ Ω / sq. More preferably, it is as follows.

  Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these examples.

Example 1
On a biaxially stretched polyethylene terephthalate film (refractive index of 1.65) having a thickness of 100 μm, a water-dispersible polyester resin was applied as an easy-adhesive layer (refractive index of 1.58). The coating composition for forming a hard coat layer having the following composition was applied to the film so as to have a dry film thickness of 2.5 μm and dried. Subsequently, the paint was cured by irradiating ultraviolet rays with a high-pressure mercury lamp to form a hard coat layer (refractive index 1.63).
Next, a low refractive index layer-forming coating material A having the following composition was applied on the hard coat layer so as to have a dry film thickness of 70 nm (refractive index of the low refractive index layer: 1.39), and dried by heating at 120 ° C. The antireflection film of the present invention was produced.

(Hard coat layer forming paint)
-Ionizing radiation curable resin 100 parts by weight Dipentaerythritol hexaacrylate (DPHA) 90 parts by weight (Nippon Kayaku Co., Ltd. 6-functional acrylic UV curable resin, solid content 100%, refractive index 1.48)
N-vinylcaprolactam 10 parts by mass (BASF Japan, solid content 100%)
・ 1000 parts by mass of antimony pentoxide sol
(Solid content 300 parts by mass)
(Catalytic Chemical Industries, ELCOM RK-1022SBV, solid content 30%, solvent is denatured alcohol, refractive index 1.70)
・ 7 parts by weight of photopolymerization initiator (Irgacure (IR) 184, manufactured by Ciba Specialty Chemicals)
-Photopolymerization initiator 1 part by mass (Irgacure (IR) 907 manufactured by Ciba Specialty Chemicals)
・ Solvent 60 parts by weight (Butyl cellosolve)

(Composition of paint A for forming low refractive index layer)
・ The following matrix component A 3333 parts by mass
(Solid content 100 parts by mass)
・ Hollow silica dispersion sol 250 parts by mass
(Solid content 50 parts by weight)
(Catalytic Chemical Industries, ELCOM RK-1018 SIV, solid content 20%, solvent is methyl isobutyl ketone (MIBK), hollow silica average particle size is 40 nm)
・ Graft copolymer 67 parts by mass
(Solid content 20 parts by mass)
(Toagosei Co., Ltd., Cymac US-270, solid content 30%, comb-shaped graft polymer in which the trunk portion is an acrylic polymer and the branch portion is made of silicone)
・ Solvent 4850 parts by mass (Methyl isobutyl ketone (MIBK))

(Preparation of matrix component A)
A 1 liter flask equipped with a stirrer, a condenser and a thermometer was charged with 29.9 g (0.05 mol) of the following disilane compound (1) and 125 g of t-butanol and stirred at 25 ° C. .10 g of 1N aqueous acetic acid was added dropwise over 10 minutes. The mixture was further stirred at 25 ° C. for 20 hours to complete hydrolysis. To this, 2 g of aluminum acetylacetonate as a condensation catalyst and 1 g of polyether-modified silicone as a leveling agent were added, and the mixture was further stirred for 30 minutes. Paint prepared by diluting and adding 40 g of propylene glycol monomethyl ether and 40 g of diacetone alcohol. (Solid content 3%)
_{(CH 3 O) 3 Si-} C 2 H 4 -C 6 F 12 -C 2 H 4 -Si (OCH 3) 3 (1)

The following evaluation was performed about the obtained antireflection film.
(1) Minimum reflectance Using a spectrophotometer [manufactured by Shimadzu Corporation, Solid Spec 3700], the reflectance at a wavelength of 380 to 780 nm is measured, and the minimum value is recorded. If the waveform is wavy, smoothing processing is performed to obtain the minimum value.
(2) Total light transmittance It was measured using a turbidimeter [Nippon Denshoku Industries Co., Ltd. NDH2000] according to JIS K7136.
(3) Haze The haze was measured using a turbidimeter [Nippon Denshoku Industries Co., Ltd. NDH2000] according to JIS K 7136.
(4) Crack generation (coating)
The obtained antireflection film was allowed to stand in a gear oven at 130 ° C. for 5 minutes and then taken out. Further, the film was wound around a rod having a diameter of 1 cm, and the state of cracks in the coating film was observed.
○: No cracks at all Δ: Slight cracks are observed ×: Many cracks are recognized (5) Pencil hardness Pencil [Mitsubishi Pencil Co., Ltd., Uni] is used according to JIS K 5400 8.4.2. And evaluated by scratches on the coating film.
(6) Steel wool resistance Steel wool [Nippon Steel Wool Co., Ltd., # 0000] is rolled and rubbed 10 times with a load of 200 g, and the condition of the scratch is observed. judge.
○: No scratches at all.
Δ: 1 to 9 scratches are observed.
X: 10 or more scratches are observed.
(7) Coating film adhesion The obtained antireflection film was allowed to stand for 500 hours at 60 ° C. and 90% RH, and then in accordance with JIS K 5400. After attaching cello tape (manufactured by Nichiban, registered trademark), a 90 ° peel test was performed. The coating film adhesion was evaluated by counting the number of remaining films in 100 squares.
○: 100/100
Δ: 99-80 / 100
X: Less than 80/100
(8) Curling property A sample is prepared in a size of 10 cm × 10 cm, and the curl heights at the four corners when the sample is placed on a horizontal surface are measured, and determined according to the following criteria.
○: Curl height is less than 20 mm Δ: Curl height is 20 mm or more and less than 50 mm ×: Curl height is 50 mm or more (9) Surface resistivity Use a resistivity meter [Mitsubishi Chemical Corporation, Hiresta MCP-HT450] Measured.
(10) Alkali resistance A 2% NaOH aqueous solution is dropped on the film surface, wiped off after standing for 20 minutes, and the contamination status is visually determined according to the following criteria.
○: No contamination is seen.
Δ: Slightly contaminated
X: Significantly contaminated.
(11) Interference fringes Place an antireflection film on black paper and observe the interference fringes around the image of the fluorescent lamp by illuminating with a three-wavelength fluorescent lamp [Matsushita Electric Industrial Co., Ltd., Palook, 20W, daylight white]. The interference fringes are determined according to the following criteria.
○: Interference fringes are hardly observed.
Δ: Interference fringes are faintly recognized.
X: Interference fringes are clearly recognized.

  The results are shown in Table 1 below.

Example 2
In Example 1, Example 1 was repeated except that the DPHA content was changed to 96 parts by mass and the N-vinylcaprolactam content was changed to 4 parts by mass. The results are shown in Table 1 below.

Example 3
In Example 1, Example 1 was repeated except that the amount of DPHA was changed to 82 parts by mass and the amount of N-vinylcaprolactam was changed to 18 parts by mass. The results are shown in Table 1 below.

Example 4
In Example 1, Example 1 was repeated except that the blending amount of the antimony pentoxide sol was changed to 733 parts by mass (solid content 220 parts by mass). The results are shown in Table 1 below.

Example 5
In Example 1, Example 1 was repeated except that the blending amount of the antimony pentoxide sol was changed to 1833 parts by mass (solid content 550 parts by mass). The results are shown in Table 1 below.

Example 6
In Example 1, the amount of DPHA used was changed to 45 parts by mass, and petalisitol triacrylate PETA (manufactured by Toagosei Co., Ltd., trifunctional acrylic UV curable resin, solid content 100%, refractive index 1.49). Example 1 was repeated except that 45 parts by weight of The results are shown in Table 2 below.

Example 7
In Example 1, Example 1 was repeated except that the thickness of the hard coat layer was changed to 4.0 μm. The results are shown in Table 2 below.

Example 8
In Example 1, Example 1 was repeated except that the thickness of the hard coat layer was changed to 1.5 μm. The results are shown in Table 2 below.

Examples 9-10
In Example 1, Example 1 was repeated except that the coating material A for forming a low refractive index layer was changed as follows. The results are shown in Table 2 below.

(Low refractive index layer-forming coating material B of Example 9)
· Hollow silica particles (particle size 40-60 nm) are added to ELCOM P-5012, silica matrix, fluorosilicone matrix, manufactured by Catalyst Kasei Kogyo Co., Ltd., solid content 2 mass%, main solvent isopropyl alcohol. The refractive index of the low refractive index layer formed by the paint is 1.40.

(Low Refractive Index Layer Coating Material C of Example 10)
A paint obtained by removing 250 parts by mass (50 parts by mass of solid content) of the hollow silica dispersion sol from the paint A for forming a low refractive index layer. The refractive index of the low refractive index layer formed by the paint is 1.41.

Comparative Example 1
In Example 1, Example 1 was repeated except that the DPHA content was changed to 98 parts by mass and the N-vinylcaprolactam content was changed to 2 parts by mass. The results are shown in Table 3 below.

Comparative Example 2
In Example 1, Example 1 was repeated except that the DPHA content was changed to 77 parts by mass and the N-vinylcaprolactam content was changed to 23 parts by mass. The results are shown in Table 3 below.

Comparative Example 3
In Example 1, Example 1 was repeated except that the DPHA content was changed to 100 parts by mass and the N-vinylcaprolactam content was changed to 0 parts by mass. The results are shown in Table 3 below.

Comparative Example 4
In Example 1, Example 1 was repeated except that the amount of antimony pentoxide sol used was changed to 500 parts by mass (solid content 150 parts by mass). The results are shown in Table 3 below.

Comparative Example 5
In Example 1, Example 1 was repeated except that the amount of antimony pentoxide sol used was changed to 2333 parts by mass (solid content: 700 parts by mass). The results are shown in Table 3 below.

Comparative Example 6
In Example 1, N-vinylcaprolactam is not used, but instead Kayarad R-128H (manufactured by Nippon Kayaku, monofunctional monomer, ECH-modified phenoxy acrylate, refractive index = 1.527, Tg = 17 ° C.) is used. Example 1 was repeated except that it was. The results are shown in Table 4 below.

Comparative Example 7
In Example 1, N-vinylcaprolactam is not used, and instead, Kayarad R-167 (manufactured by Nippon Kayaku, bifunctional monomer, ECH-modified 1,6 hexanediol diacrylate, refractive index = 1.482) is used. Example 1 was repeated except that it was. The results are shown in Table 4 below.

Comparative Example 8
In Example 1, Example 1 was repeated except that the thickness of the hard coat layer was changed to 0.2 μm. The results are shown in Table 4 below.

Comparative Example 9
In Example 1, Example 1 was repeated except that the thickness of the hard coat layer was changed to 6.0 μm. The results are shown in Table 4 below.

The following items are derived from the above table.
In Example 1, the hard coat layer is within a specific thickness range, and N-vinylcaprolactam is used as a part of the constituent components of the matrix component (ionizing radiation curable resin) of the hard coat layer, and pentoxide is used. By setting the blending amount of antimony appropriately, there is no crack in the hard coat layer after UV irradiation, excellent coating adhesion with the base film, low minimum reflectance, transparency, and steel wool resistance An antireflection film having excellent properties, antistatic properties, curling properties, and alkali resistance and having no interference fringes can be provided.
Example 2 was an example in which 4 parts by mass of N-vinylcaprolactam was added, and the occurrence of cracks (coating film), coating film adhesion, and curling properties were evaluated as Δ. Other performance was good.
Example 3 is an example in which 18 parts by mass of N-vinylcaprolactam was added, and the steel wool resistance was evaluated as Δ. Other performance was good.
Example 4 was an example in which 220 parts by mass of antimony pentoxide was added, and the interference fringes were evaluated as Δ. Other performance was good.
Example 5 was an example in which 550 parts by mass of antimony pentoxide was added, and the occurrence of cracks (coating film) was evaluated as Δ. Other performance was good.
-Example 6 was the example which added 45 mass parts of DPHA and 45 mass parts of PETA, and showed the same performance as Example 1.
In Example 7, the thickness of the hard coat layer was 4.0 μm, and the interference fringes were evaluated as Δ. Other performance was good.
Example 8 was an example in which the thickness of the hard coat layer was 1.5 μm, and showed the same performance as Example 1.
-Example 9 is an example using the low-refractive-index paint B, and since the silica matrix was used, alkali resistance was (triangle | delta) evaluation. Other performance was good.
Example 10 is an example in which the low refractive index paint C was used, and since hollow silica particles were not used in the low refractive index layer, the minimum reflectance was slightly deteriorated, but other performances were good.

Comparative Example 1 was an example in which 2 parts by mass of N-vinylcaprolactam was added, and was outside the scope of the present invention, so crack generation (coating film), coating film adhesion, and curling properties were evaluated as x.
Comparative Example 2 is an example in which 23 parts by mass of N-vinylcaprolactam was added, and was outside the scope of the present invention, so the steel wool resistance was evaluated as x.
Since Comparative Example 3 was an example in which N-vinylcaprolactam was not added and was outside the scope of the present invention, crack generation (coating film), coating film adhesion, and curling properties were evaluated as x.
Comparative Example 4 was an example in which 150 parts by mass of antimony pentoxide was added and was outside the scope of the present invention, so the interference fringes were evaluated as x.
Comparative Example 5 is an example in which 700 parts by mass of antimony pentoxide is added and is outside the scope of the present invention. Therefore, occurrence of cracks (coating film), interference fringes are evaluated as x, and coating film adhesion is evaluated as Δ. It was.
Comparative Example 6 is an example in which 10 parts by mass of Kayarad R-128H was added, and N-vinylcaprolactam was not used, so the occurrence of cracks (coating film) and coating film adhesion were evaluated as x.
Comparative Example 7 is an example in which 10 parts by mass of Kayrad R-167 was added, and N-vinylcaprolactam was not used, so the occurrence of cracks (coating film) and coating film adhesion were evaluated as x.
Comparative Example 8 is an example in which the thickness of the hard coat layer is 0.2 μm, and is outside the scope of the present invention. Therefore, the steel wool resistance and interference fringes were evaluated as x.
Comparative Example 9 is an example in which the thickness of the hard coat layer is 6.0 μm, and is outside the scope of the present invention, so the interference fringes were evaluated as x.

  The antireflection film of the present invention is free from cracks in the hard coat layer after UV irradiation, has excellent coating film adhesion to the substrate film, has a low minimum reflectance, transparency, steel wool resistance, and antistatic property It is useful for preventing reflection on the surface of liquid crystal display devices, plasma display panels, personal computers, televisions, touch panels, etc. because it has excellent properties, curling properties, and alkali resistance, and interference fringes are not noticeable.

Claims (7)

An antireflection film having a hard coat layer on a base film made of biaxially stretched polyethylene terephthalate, and further having a low refractive index layer on the hard coat layer,
The hard coat layer has a thickness of 0.5 to 5 μm;
100 mass of ionizing radiation curable resin in which the hard coat layer is composed of 80 to 97 mass% of polyfunctional (meth) acrylate having 2 or more (meth) acryloyl groups in the molecule and 20 to 3 mass% of N-vinylcaprolactam. Antireflective film characterized by being formed by blending 200 to 600 parts by mass of antimony pentoxide in a part and curing it.   2. The antireflection film according to claim 1, wherein the polyfunctional (meth) acrylate having two or more (meth) acryloyl groups in the molecule is dipentaerythritol hexaacrylate.   The antireflection film according to claim 1, wherein the antimony pentoxide has an average particle size of 5 to 100 nm. A matrix component whose main component is a disilane compound having a divalent organic group containing one or more fluorine atoms or a (partial) hydrolyzate thereof; a hollow silica particle; and a radical polymerizable monomer Formed from a composition for forming a low refractive index layer containing a graft copolymer having a repeating unit formed using a body as a trunk and a silicone as a branch,
The composition for forming a low refractive index layer is formed by blending 20 to 120 parts by mass of the hollow silica particles and 5 to 40 parts by mass of the graft copolymer with respect to 100 parts by mass of the matrix component. The antireflection film according to claim 1. The disilane compound is represented by the following formula (1):
^{_{X m R 1 3-m Si}} -Y-SiR 1 3-m X m (1)
Wherein R ¹ is a monovalent hydrocarbon group having 1 to 6 carbon atoms, Y is a divalent organic group containing one or more fluorine atoms, X is a hydrolyzable group, m is 1, 2 or 3. is there.)
The antireflection film according to claim 4, which is represented by:   The average particle diameter of the said hollow silica particle is 5-100 nm, The antireflection film of Claim 4 characterized by the above-mentioned.   The antireflection film according to claim 4, wherein a trunk portion composed of repeating units formed using the radical polymerizable monomer is an acrylic polymer.