JP2003149407A - Antireflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antireflection film having a laminated body and characterized by excellent optical characteristics because of high humidity/heat resistance of respective thin layers constituting the laminated body and stable refractive indexes of respective thin films, a high formation speed and high adhesiveness of respective thin layers. SOLUTION: In the antireflection film having a base material, a bar code layer arranged on the surface of the base material and the laminated body consisting of laminated thin layers formed on the surface of the bar code layer, the laminated body is formed by laminating a thin layer formed by a plasma CVD method and a thin layer formed by a sputtering method or a deposition method.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an antireflection film.

[0002]

2. Description of the Related Art Computers such as liquid crystal displays, plasma displays, CRTs, word processors, televisions,
Transparent substrates such as glass and plastic are used for various displays used for display boards and the like, display bodies such as measuring instruments, rearview mirrors, goggles, window glasses and the like. Since characters, figures, and other information are read through these transparent substrates, there is a drawback that it becomes difficult to read such information when light is reflected on the surface of the transparent substrate.

At present, in order to solve the above-mentioned drawbacks, an antireflection film comprising a substrate, a hard coat layer, and a laminate formed by laminating a plurality of thin layers having different refractive indexes from each other. It is used to prevent the reflection of light by sticking the antireflection film on the surface of the transparent substrate.

As a method of forming a laminate in such an antireflection film, a method of forming by a sputtering method or a vapor deposition method has been conventionally known.

However, when the laminated body is formed by the sputtering method, although the layer forming accuracy is good, there is a problem that productivity is poor because the forming speed is very slow. Further, in the case of forming a laminated body by the vapor deposition method, although there is no problem in the layer forming speed, the forming accuracy is poor, and therefore the yield is poor, which causes a problem of increasing the cost of the antireflection film. .

In order to solve the above problems, at present, a method of forming a laminated body by a plasma CVD method has been developed. By forming the stacked body by the plasma CVD method, the formation speed can be dramatically increased as compared with the formation by the sputtering method or the like.

[0007]

However, when the laminated body is formed by the plasma CVD method, the following problems newly arise.

First, the first problem is that the adhesion between the thin layers forming the laminated body becomes worse than in the case where the thin layers are formed by sputtering or vapor deposition.

A second problem is that, of the thin layers forming the laminate, when the titanium oxide layer functioning as a high refractive index layer is formed by the plasma CVD method, the titanium oxide layer is Moisture and heat resistance is poor, and the refractive index may not be stable.

The present invention has been made in view of the above problems, and in an antireflection film having a laminated body, each thin layer constituting the laminated body has good wet heat resistance, and therefore the refractive index of each thin layer is stable. Therefore, the main object is to provide an antireflection film having excellent optical properties, a high formation rate, and excellent adhesion of each thin layer.

[0011]

According to a first aspect of the present invention, a substrate, a hard coat layer located on the substrate, and a plurality of thin layers laminated on the hard coat layer are laminated. In the antireflection film having a laminated body, the laminated body is formed by laminating a thin layer formed by a plasma CVD method and a thin layer formed by a sputtering method or a vapor deposition method. It has characteristics.

According to the antireflection film of the present invention, the laminate constituting the antireflection film of the present invention has a plasma C
Since the thin layer formed by the VD method and the thin layer formed by the sputtering method or the vapor deposition method are laminated, all the thin layers forming the laminated body are formed by the sputtering method or the vapor deposition method. Compared to forming
The productivity can be improved, while the wet heat resistance of each thin layer can be improved and the adhesion between each thin layer can be improved compared to forming all thin layers by the plasma CVD method. It can be done.

Further, in the invention described in claim 2, among the thin layers forming the laminate, the thin layer formed by the plasma CVD method is a low refractive index layer or a medium refractive index layer, and the sputtering method or It is characterized in that the thin layer formed by the vapor deposition method is a high refractive index layer.

According to the antireflection film of the present invention, among the thin layers forming the laminate, the thin layer formed by the plasma CVD method is the low refractive index layer or the medium refractive index layer, and the sputtering method or the vapor deposition method. Since the thin layer formed by the method is a high refractive index layer, there is no particular problem even when formed by the plasma CVD method (that is, there is no problem in moist heat resistance), low refractive index layer or medium refractive index layer. Can be formed at a high speed by the plasma CVD method. On the other hand, when formed by the plasma CVD method,
The refractive index of the high-refractive-index layer can be stabilized by forming only the high-refractive-index layer, which may not be stable due to poor wet heat resistance, by a sputtering method or a vapor deposition method.

Further, in the invention described in claim 3, in the invention described in claim 2, the low refractive index layer formed by the plasma CVD method has a refractive index of 1.40 to 1.46.
(Λ = 550 nm), and 2800 to 3000
infrared absorption by C-H stretching vibration at cm ^-1 , and 12
Infrared absorption by Si-CH ₃ stretching vibration at 00～1400Cm ^-1 is characterized in that each 0.1 cm ^-1 or less of the silica layer.

According to the present invention, the silica layer used as the low refractive index layer of the laminate has a refractive index of 1.40 to 1.46 (λ
= 550 nm), the silica layer has excellent adhesion and a high formation rate. In addition, the silica layer has excellent optical properties and can efficiently prevent reflection of light, and can be used as a low refractive index layer in a laminate of antireflection films. Furthermore, 2800-300
Infrared absorption by C-H stretching vibration at 0 cm ^-1 , and 1
200~1400cm infrared absorption by Si-CH ₃ stretching vibration of ^-1 or less 0.1 cm ^-1, respectively, that is because it is below the detection sensitivity is clear that the organic component in the silica layer is hardly contained And as a result,
Although it is a silica layer formed by the plasma CVD method, it is considered to have excellent chemical resistance. The low refractive index layer is
Since it is often used as the outermost surface layer of the laminate, when alkali treatment or the like is performed after the antireflection film is produced,
In some cases, it was dissolved in an alkaline solution, but according to the present invention, the silica layer as the above-mentioned hand-in-one establishment layer has excellent chemical resistance, and therefore it is not dissolved.

Further, in the invention described in claim 4, in the invention described in claim 2 or 3, the layer structure of the laminated body is formed by plasma CVD from the hard coat layer side. It is characterized by being a high refractive index layer, a high refractive index layer formed by a sputtering method or a vapor deposition method, and a low refractive index layer formed by a plasma CVD method.

According to the antireflection film of the present invention, the layer structure of the laminate is such that the plasma C is applied from the hard coat layer side.
Medium refractive index layer formed by VD method, high refractive index layer formed by sputtering method or vapor deposition method, plasma C
Since it is a low-refractive index layer formed by the VD method, reflection can be efficiently prevented by the layer structure, and a low-refractive index layer and a medium-refractive index layer are formed by a plasma CVD method to obtain a high refractive index. Since the layer is formed by the sputtering method or the vapor deposition method, the same effects as the inventions described in the first and second aspects can be obtained.

The invention described in claim 5 is the same as claim 2
Alternatively, in the invention according to claim 3, the layer structure of the laminate is a high refractive index layer formed by a sputtering method or a vapor deposition method, a low refractive index layer formed by a plasma CVD method, from the hard coat layer side, It is characterized by being a high refractive index layer formed by a sputtering method or a vapor deposition method and a low refractive index layer formed by a plasma CVD method.

According to the antireflection film of the present invention, the layer structure of the laminate comprises a high refractive index layer formed by a sputtering method or a vapor deposition method and a low refractive index formed by a plasma CVD method from the hard coat layer side. Since the refractive index layer, the high refractive index layer formed by the sputtering method or the vapor deposition method, and the low refractive index layer formed by the plasma CVD method,
With the layer structure, reflection can be efficiently prevented, and the low refractive index layer is formed by the plasma CVD method, and the high refractive index layer is formed by the sputtering method or the vapor deposition method. The same effect as the invention described in claim 2 can be obtained.

According to a sixth aspect of the invention, in the invention according to any one of the second to sixth aspects, the low refractive index layer or the medium refractive index layer formed by the plasma CVD method is It is a silicon oxide layer, and is characterized in that the high refractive index layer formed by a sputtering method or a vapor deposition method is a titanium oxide layer or an ITO layer exhibiting high resistance.

According to the antireflection film of the present invention, first, since the low refractive index layer or the medium refractive index layer formed by the plasma CVD method is a silicon oxide layer, the low refractive index layer or the medium refractive index layer is formed. It is possible to form a thin layer with a suitable refractive index. Further, the high refractive index layer formed by the sputtering method or the vapor deposition method is a titanium oxide layer,
Or, since it is an ITO layer exhibiting high resistance, it is possible to form a thin layer having a refractive index layer suitable for a high refractive index layer, and also when the ITO layer is used as a high refractive index layer, Since the ITO layer has high resistance,
It is possible to form a low refractive index layer on the layer by a plasma CVD method.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The antireflection film of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic sectional view of the antireflection film of the present invention.

As shown in FIG. 1, an antireflection film 1 of the present invention comprises a base material 2, a hard coat layer 3 located on the base material 2, a hard coat layer 3 and a plurality of thin layers. (5
To 7) are laminated. The laminate 4 is characterized in that it is composed of thin layers (5, 7) formed by plasma CVD and thin layers (6) formed by sputtering or vapor deposition. There is.

As described above, not all of the thin layers forming the laminated body 4 are formed by the plasma CVD method only, or the sputtering method or the vapor deposition method, but the plasma CVD method, the sputtering method, or the like depending on the thin layer to be formed. Of plasma CVD method (high thin layer formation speed) and sputtering method or vapor deposition method (adhesion between thin layers is good and high refractive index layer is formed) Even in such a case, the layer can have both wet heat resistance and stable refractive index), and an antireflection film having an excellent antireflection function can be obtained.

Below, each of the thin layers (low refractive index layer 7, medium refractive index layer 5, high refractive index) constituting the base material 2, the hard coat layer 3, and the laminate 4 constituting the antireflection film 1 of the present invention. The structures of the rate layer 6) and the laminated body 4 will be described respectively. [1] Base Material First, the base material 2 will be described. In the antireflection film 1 of the present invention, the base material 2 is a portion that is a base of the antireflection film 1. The substrate 2 is not particularly limited as long as it is a polymer film transparent in the visible light range. Examples of the polymer film include triacetyl cellulose film, diacetyl cellulose film, acetate butyrate cellulose film, polyether sulfone film, polyacrylic film, polyurethane film, polyester film, polycarbonate film, polysulfone film, polyether. Examples thereof include a film, a trimethylpentene film, a polyetherketone film, an acrylonitrile film, a methacrylonitrile film and the like. Furthermore, a colorless film can be used more preferably. Among them, a uniaxially or biaxially stretched polyester film is preferably used because it has excellent transparency and heat resistance, and a polyethylene terephthalate (PET) film is particularly preferable. Triacetyl cellulose is also preferably used because it has no optical anisotropy. The thickness of the polymer film is usually 6 μm to 188 μm
The thing of a grade is used suitably. [2] Hard Coat Layer Next, the hard coat layer 3 will be described. In the antireflection film 1 of the present invention, the hard coat layer 3 is a layer formed for the purpose of imparting strength to the antireflection film 1.

As the material for forming the hard coat layer 3 in the antireflection film 1 in the present invention,
Like the base material 2, it is necessary that the material is transparent in the visible light range and capable of imparting strength to the antireflection film 1. The strength is JISK5.
It is preferable that the pencil altitude test shown by 400 shows an altitude of H or higher.

Specifically, it is preferable to use a thermosetting resin and / or an ionizing radiation type resin (these may be collectively referred to as a reaction curable resin in the present invention),
More specifically, those having an acrylate functional group, for example, relatively low molecular weight polyester, polyether, acrylic resin, epoxy resin, polyurethane,
(Meth) acrylates of polyfunctional compounds such as alkyd resins, spiroacetal resins, polybutadiene, polythiol polyene resins, and polyhydric alcohols (hereinafter, acrylate and methacrylate are referred to as (meth) acrylate). Oligomers or prepolymers and reactive diluents ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene,
Monofunctional monomers such as vinyltoluene and N-vinylpyrrolidone, and polyfunctional monomers such as trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) ) Acrylate, pentaerythritol tri (meth)
Acrylate, dipentaerythritol hexa (meth)
Those containing a relatively large amount of acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, etc. are used.

Further, when the above-mentioned ionizing radiation curable resin is used as an ultraviolet curable resin, a photopolymerization initiator such as acetophenones, benzophenones, Michler benzoyl benzoate, α-amyloxime can be used as a photopolymerization initiator. It is preferable to use a mixture of esters, thioxanthones, and n-butylamine, triethylamine, tri-n-butylphosphine, etc. as photosensitizers.

The above ionizing radiation curable resin contains a reactive organosilicon compound represented by the general formula RmSi (OR ') n (wherein R and R'represent an alkyl group having 1 to 10 carbon atoms, m + n = 4, and m and n are each integers.). Examples of such a silicon compound include tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-silane. Butoxysilane, tetrapentaethoxysilane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-
Butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane,
Examples thereof include dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane, dimethylbutoxysilane, methyldimethoxysilane, methyldiethoxysilane, and hexyltrimethoxysilane.

The layer thickness of such a hard coat layer 3 is usually in the range of 1 to 30 μm, and the production method thereof may be an ordinary coating method, and is not particularly limited. [3] Laminate The laminate 4 in the antireflection film 1 of the present invention is formed by laminating thin layers having different optical characteristics, and the optical characteristics (especially refractive index) of each thin layer and the layer constitution. Thus, the laminated body 4 as a whole is configured to effectively prevent reflection.

Usually, the thin layers constituting the laminate 4 are roughly classified into a low refractive index layer, a medium refractive index layer and a high refractive index layer according to the refractive index thereof. Here, in the present invention, a low refractive index layer,
The medium-refractive index layer and the high-refractive index layer are names for distinguishing the respective thin layers when the thin layers constituting the laminate 4 are relatively compared by their respective refractive indexes. A layer having a relatively high refractive index is a high refractive index layer, a layer having a relatively low refractive index is a low refractive index layer, and a layer having a refractive index intermediate between the high refractive index layer and the low refractive index layer is a medium refractive index. It is a stratum. Generally, a refractive index of 1.80 or more is a high refractive index layer, a refractive index of 1.55 or more and less than 1.80 is a medium refractive index layer, and a refractive index of 1.55.
In many cases, the refractive index of less than 1.80 is a low refractive index layer.
Above, less than 1.80 is a medium refractive index layer, and less than 1.55 is a low refractive index layer.

Each thin layer will be specifically described below.

(3-1) Low Refractive Index Layer In the antireflection film 1 of the present invention, the low refractive index layer (7) is one of the thin layers forming the laminate 3, and its refractive index is Is a thin layer of less than 1.55 (λ = 550 nm). In this way, by using a layer having a relatively low refractive index as a thin layer in the laminated body 4, it is possible to efficiently prevent reflection in the laminated body 4 as a whole. In the antireflection film 1 of the present invention, the position of the low refractive index layer (7) in the laminate 4 is not particularly limited, but the low refractive index layer (7) is usually shown in FIG. Thus, it is preferable to use it for the outermost layer of the laminate 4 (on the side opposite to the hard coat layer 3).

In the present invention, the thin layer that can be used as the low refractive index layer (7) may be a thin layer having transparency and a refractive index of less than 1.55 (λ = 550 nm). Although not particularly limited, a thin layer that can be formed by the plasma CVD method is particularly preferable in the present invention.

Specific examples of the low refractive index layer (7) include a silicon oxide layer, a magnesium fluoride layer, a silicon oxyfluoride layer, and the like. Among these, the silicon oxide layer is particularly preferable. It is preferably used as a low refractive index layer.

The silicon oxide layer has a refractive index of 1.55.
Less than (λ = 550 nm) is relatively easy, and even when formed by the plasma CVD method, a thin layer having excellent wet heat resistance and a stable refractive index can be obtained. Is because the thin layer formation rate is high. The composition of the silicon oxide layer is simply Si.
It need not be Ox, but may be a silicon oxide layer (SiOxCy) containing carbon. In this way, by containing carbon in the silicon oxide layer, the refractive index of the silicon oxide layer can be more easily set to a desired refractive index.

The layer thickness of such a low refractive index layer is not particularly limited, but is preferably 10 to 1000 nm, and particularly preferably 50 to 150 nm. When the layer thickness is smaller than the above range, the antireflection effect may not be exerted, and when the layer thickness is larger than the above range, the entire layer may become brittle and may lack formability. .

Here, the plasma CVD method used when forming the low refractive index layer (7) in the antireflection film 1 of the present invention will be specifically described.

In the present invention, the plasma CVD method means that atomic or molecular radical species are generated by the plasma generation in a reaction chamber into which a predetermined gas is introduced and are attached to the solid surface. This is a layering method that utilizes the phenomenon that volatile molecules are released and taken into the solid surface. By forming the antireflection film of the present invention using the plasma CVD method, it is possible to efficiently form a plurality of layers collectively. Further, there are two types of the plasma CVD method, a capacitively coupled plasma CVD method and an inductively coupled plasma CVD method, depending on the difference in the method of applying electric power used to generate plasma.
In the present invention, either plasma CVD method can be used.

Here, in the present invention, among the above-mentioned plasma CVD methods, plasma C as shown in FIG. 2 is used.
It is particularly preferable to use a VD device. The plasma C
This is because the antireflection film of the present invention can be continuously produced by the VD device, and the temperature of the polymer film as the base material can be accurately controlled.

The plasma CVD apparatus 20 shown in FIG. 2 is a capacitively coupled plasma CVD apparatus, in which a web-shaped polymer film 21 is unwound from a base material unwinding section 22 and a reaction chamber in a vacuum container 23 is provided. It is introduced in (a, b, c). Then, a predetermined layer is formed on the stratification drum 24 in the reaction chamber and is wound by the base material winding unit 26.

The plasma CVD apparatus 20 has a plurality of (3
It is characterized in that it has one reaction chamber, and each reaction chamber (a, b, c) is formed by being isolated by an isolation wall 25. Here, for convenience of the following description, the three reaction chambers are referred to as a reaction chamber a, a reaction chamber b, and a reaction chamber c from the right side. Then, in each reaction chamber, electrode plates a1, b1, c are respectively provided.
1 and raw material gas introduction ports a2, b2, and c2 are installed. Each reaction chamber (a, b, c) is installed along the outer periphery of the stratification drum 24. This is because the polymer film on which the antireflection laminate is formed is inserted into the reaction chamber in synchronization with the layering drum 24 and forms the antireflection layer on the layering drum. This is because the layers can be continuously laminated by arranging in this manner.

According to the plasma CVD apparatus as described above, it is possible to form layers independently in each reaction chamber by changing the source gas introduced into each reaction chamber.

In the present invention, the plasma C as described above is used.
Low refractive index layer (7) using a VD device (for example, reaction chamber a)
In the case of forming the silicon oxide layer as described above, it is preferable to use organic silicone as a source gas, and specifically, hexamethyldisiloxane (HMDSO), tetramethyldisiloxane (TMDSO), methyltrimethoxysilane (MTMOS). , Methylsilane, dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, tetramethoxysilane, octamethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, tetraethoxysilane and the like can be used.

Further, in the present invention, among the low refractive index layers formed by the plasma CVD method as described above, the refractive index is 1.40 to 1.46 (λ = 550 nm) and 2800, in particular. infrared absorption by C-H stretching vibration in ~3000cm ^-1, and 1200～1400Cm ^-1
Infrared absorption by Si—CH ₃ stretching vibration at 0.1 cm ⁻¹ or less for each silica layer is preferably used as the low refractive index layer.

This is because in the antireflection film, the lower the refractive index of the low refractive index layer in the laminate, the better. The refractive index within the above range is suitable for the low refractive index layer.

The silica layer is 2800-300.
Infrared absorption by C-H stretching vibration at 0 cm ^-1 , and 1
Infrared absorption by Si-CH ₃ stretching vibration at 200～1400Cm ^-1 is 0.1 cm ^-1 or less, it is characterized in that less that is the detection sensitivity.

The infrared absorption by C-H stretching vibration at 2800 to 3000 cm ^-1, and 1200～1400Cm ^-1
Infrared absorption by Si-CH ₃ stretching vibration at 0.1c
The fact that it is m ⁻¹ or less means that there is almost no C—H bond or Si—CH 3 bond in the silica layer. That is, it is considered that the silica layer of the present invention does not contain a carbon compound (organic substance), and is therefore considered to have excellent chemical resistance.

The infrared absorption is measured by a known IR spectrum transmission method, and the value of ∫ (α / f) df in infrared absorption of each stretching vibration is calculated (α: Absorption coefficient, f: frequency).

(3-2) Medium refractive index layer Next, the medium refractive index layer will be described.

In the antireflection film 1 of the present invention, the medium refractive index layer (5) is one of the thin layers forming the laminate 3.
It is a thin layer having a refractive index of 1.55 or more and less than 1.80. The medium refractive index layer (5) having such a refractive index is a thin layer used to enhance the antireflection function, and is not necessarily a thin layer required in the laminate 4. The position where the medium refractive index layer is provided is not particularly limited, and it may be provided at any position as long as the antireflection function is improved in the laminate 4 as a whole. However, since the low refractive index layer (7) and the high refractive index layer (6) are in contact with each other, light reflection can be efficiently prevented (see FIG. 1). (5) is a portion other than between the low refractive index layer and the high refractive index layer,
For example, it is preferably provided below the high refractive index layer as shown in FIG.

In the present invention, the thin layer that can be used as the medium refractive index layer (5) has transparency in the visible light region and has a refractive index of 1.55 or more and less than 1.80 (λ = 5
It is not particularly limited as long as it is a thin layer having a thickness of 50 nm, but in the present invention, like the low refractive index layer described above, a thin layer that can be formed by the plasma CVD method is particularly preferable. .

Examples of such a medium refractive index layer (5) include a carbon-containing silicon oxide layer, Al ₂ O ₃ , SiN,
A material in which fine particles of SiON, ZrO ₂ , SiO ₂ , or ZnO ₂ are dispersed in a silicon oxide layer is preferably used. By mixing the above-mentioned fine particles into the silicon oxide layer, the refractive index thereof is 1.55 or more and less than 1.80 (λ = 550n
m) is relatively easy, and even if the silicon oxide layer is formed by the plasma CVD method, a thin layer having excellent wet heat resistance and a stable refractive index can be obtained. Since the plasma CVD method has a high thin layer forming rate, it is possible to improve the production yield of the antireflection film.

The layer thickness of such a medium refractive index layer is not particularly limited, but is preferably 5 to 300 nm, and 10
˜150 nm is particularly preferred. This is because if the layer thickness is less than 5 nm, the antireflection effect can hardly be expected, and conversely, if the layer thickness is greater than 300 nm, base material deformation or layer peeling due to layer stress may occur. Because.

Here, the plasma CVD method used when forming the medium refractive index layer (5) in the antireflection film 1 of the present invention is the same as the case of the low refractive index layer (7), and therefore it will be described. Is omitted. In the case of using the plasma CVD apparatus shown in FIG. 2, by using, for example, the reaction chamber b to form the medium refractive index layer (5), the optical characteristics of one plasma CVD apparatus can be improved. Thin layers of different (different refractive index) can be formed.

(3-3) High refractive index layer Next, the high refractive index layer will be described.

In the antireflection film 1 of the present invention, the high refractive index layer (6) means one of the thin layers forming the laminate 3.
And its refractive index is 1.80 or more (λ = 550n
m) is a thin layer. By providing a thin layer having a refractive index of 1.80 or more (λ = 550 nm) in the laminate 4 together with the low refractive index layer described above, light reflection can be efficiently prevented due to the difference in each refractive index. be able to. In the antireflection film 1 of the present invention, the high refractive index layer (6)
The position occupied by in the laminate 4 is not particularly limited, but as described above, it is more efficient that the low refractive index layer (7) and the high refractive index layer (6) are in contact with each other. Since it can prevent reflection, it is preferably provided below the low refractive index layer.

In the present invention, the thin layer that can be used as the high refractive index layer (6) has transparency in the visible light region and has a refractive index of 1.80 or more (λ = 550 nm). The thin layer is not particularly limited as long as it is a thin layer, but in the present invention, a thin layer formed by a sputtering method or a vapor deposition method is particularly preferable. As described above, by forming the high refractive index layer (6) by the sputtering method or the vapor deposition method, the forming speed is inferior to that in the case of forming by the plasma CVD method, but the wet heat resistance is excellent and therefore the refractive index is stable. This is because a high refractive index layer having excellent adhesion to other thin layers can be obtained.

Specific examples of such a high refractive index layer (7) include a titanium oxide layer, an ITO (indium / tin oxide) layer, a Y ₂ O ₃ layer, an In ₂ O ₃ layer, and a Si ₃ N layer. ₄ layers, SnO
₂ layers, ZrO ₂ layer, HfO ₂ layer, Sb ₂ O ₃ layer, Ta ₂ O
₅ layers, ZnO layer, WO ₃ layer, and the like can be exemplified, it is preferable to use an ITO layer exhibiting particularly titanium oxide layer or a high-resistance among this as a high refractive index layer.

Conventionally, the titanium oxide layer has been used as the high refractive index layer of the laminate in the antireflection film, but the titanium oxide layer is formed by the plasma CVD method like the low refractive index layer and the medium refractive index layer described above. When formed by, since the formed titanium oxide layer has poor wet heat resistance, there was a problem that the refractive index changes due to moisture in the air, etc., but according to the present invention, high refractive index Since the titanium oxide layer as the refractive index layer is formed by the sputtering method or the vapor deposition method, such a problem does not occur. In addition, by forming by a sputtering method or a vapor deposition method, the adhesion with other thin layers (low refractive index layer or medium refractive index layer) or hard coat layer can be improved.

Further, since the ITO layer usually has conductivity, it is difficult to form a thin layer by the plasma CVD method on the ITO layer formed by the sputtering method or the vapor deposition method. Since the ITO layer used as the high refractive index layer in (1) is an ITO layer exhibiting a high resistance, it is possible to form a thin layer thereon by the plasma CVD method.
Thus, the IT used as the high refractive index layer in the present invention
The reason why the O layer exhibits high resistance is that when the ITO layer is formed by a sputtering method or a vapor deposition method, it is formed under an oxygen excess condition to increase the oxygen filling rate of the ITO layer. Here, in the present invention, "high resistance" means
Refers to the sheet resistance is ^{1 × 10 4 ~1 × 10 1} 4 Ω / sq.

The layer thickness of such a high refractive index layer is not particularly limited, but is preferably 5 to 300 nm, particularly preferably 10 to 150 nm. This is because if the layer thickness is less than 5 nm, the antireflection effect can hardly be expected, and conversely if the layer thickness is greater than 300 nm,
This is because the base material may be deformed or the layer may peel due to the stress of the layer.

Here, the sputtering method and the vapor deposition method used for forming the high refractive index layer (6) in the antireflection film 1 of the present invention will be specifically described.

In the present invention, the sputtering method is a method in which high-energy particles are hit against a solid which is a base material of a thin layer called a target, and the constituent atoms of the base material are released from the surface of the solid to release the released atoms. Is deposited on a substrate to form a thin layer. Usually, cations formed by glow discharge of an inert gas such as argon are accelerated by the cathode fall voltage and collide with a target that is negatively biased, thereby repelling atoms from the surface and depositing a thin layer. It is common.

As the sputtering method used for forming the high refractive index layer (6) in the antireflection film 1 of the present invention, all of the conventionally used sputtering methods can be used. The ion beam sputtering method, the high frequency sputtering method, the direct current sputtering method, the ECR sputtering method, the magnetron sputtering method, the reactive sputtering method, and the like can be used, and the method is not particularly limited.

FIG. 3 is a schematic view of a DC sputtering apparatus for performing the DC sputtering method among the various sputtering methods. In the present invention, it is possible to form a high refractive index layer using such a device.

In the DC sputtering apparatus 30 shown in FIG. 3, the web-shaped polymer film 3 as a base material is used.
1 is unwound from the substrate unwinding section 32, and the reaction chamber 33
Will be introduced to. Then, a predetermined layer is formed on the stratification drum 34 in the reaction chamber 33, and is wound by the base material winding unit 36.

A target 35 is installed in the reaction chamber 33 of the DC sputtering apparatus 30 so as to face the layering drum 34. The layering drum 34 is an anode,
The target 35 is a cathode. And reaction chamber 3
The inside of 3 is made into a vacuum state (about 10 ⁻³ Pa), and then an inert gas such as argon or an oxygen gas is put in at 1 to 10 Pa.
By applying a direct current high voltage between the layering drum 34 and the target 35, the positive ions are converted into the cathode (target 3).
5), which causes the target to be repelled and deposited on the polymer resin on the layering drum 34.

In the present invention, when the titanium oxide layer as the high refractive index layer (6) is formed by the sputtering method, the targets thereof are Ti, Ti ₂ O ₃ and TiO _2.
2 , it is preferable to use TiO. When forming the ITO layer as the high refractive index layer (6), it is preferable to use ITO or an indium / tin alloy as the target.

In the present invention, the vapor deposition method mainly means
It is a method of forming a thin layer by evaporating a solid in a vacuum of 10 ⁻⁶ to 10 ⁻¹¹ Torr by superheat and cooling and condensing the vapor on a substrate kept at a constant temperature. In the present invention, all conventionally used vapor deposition methods can be used and are not particularly limited. In the vapor deposition method, when a titanium oxide layer as the high refractive index layer (6) is formed, the raw materials thereof are Ti and Ti.
_It is preferable to use ₂ O ₃ , TiO ₂ , or TiO. Also,
When forming the ITO layer as the high refractive index layer (6), it is preferable to use ITO or an indium / tin alloy as the raw material.

As described above, the antireflection film 1 of the present invention
In the above, the plasma CV is applied to each thin layer constituting the laminated body 4.
Instead of forming only by the D method or the sputtering method, according to each thin layer, specifically, in the low refractive index layer and the medium refractive index layer, a plasma CVD method in which the thin layer is formed at a high speed is used. In the high refractive index layer, by using a sputtering method or a vapor deposition method capable of forming a thin layer having excellent wet heat resistance and a stable refractive index, in the production of the antireflection film, its yield is also good, and reflection It is possible to provide an antireflection film having an excellent prevention function.

(3-4) Layer Structure Next, the layer structure of the laminate 4 in the antireflection film 1 of the present invention will be specifically described with reference to the drawings.

In the antireflection film 1 of the present invention,
The layer structure of the laminated body 4 is not particularly limited, and includes a thin layer formed by the plasma CVD method and a thin layer formed by the sputtering method or the vapor deposition method in the layer structure. It suffices that the entire body can have an antireflection function.

However, as the laminate 4, as shown in FIG. 1, plasma CVD is performed from the hard coat layer 3 side.
Medium refractive index layer 5 formed by a sputtering method, high refractive index layer 6 formed by a sputtering method or a vapor deposition method, and plasma C
It is preferable that the low refractive index layers 7 formed by the VD method are laminated in this order. By stacking in this way,
It is possible to effectively prevent the reflection of light from the difference in the refractive index of each thin layer, and since the high refractive index layer 6 is formed by the sputtering method or the vapor deposition method, it has excellent wet heat resistance and This is because the adhesion to the middle refractive index layer 5 which is the lower layer of the high refractive index layer 6 and the low refractive index layer 7 which is the upper layer is also good.

A laminated body 4'as shown in FIG. 4 is also preferable as the antireflection film of the present invention. As shown in FIG. 4, from the hard coat layer 3 side, the high refractive index layer 6 ′ formed by the sputtering method or the vapor deposition method and the plasma C are formed.
This is because the antireflection effect can be improved by alternately stacking the low refractive index layers 7 ′ formed by the VD method twice.

The present invention is not limited to the antireflection film and the manufacturing method thereof described above. The above-mentioned embodiment is an exemplification, and has substantially the same configuration as the technical scope described in the claims of the present invention,
Whatever has the same effect is included in the technical scope of the present invention.

[0079]

EXAMPLES The present invention will be described in more detail by way of examples. (Example 1) Using the sputtering apparatus shown in FIG.
ITO on a 75 μm thick polyethylene terephthalate (PET) film, which is the base plastic film
Layers were formed. The feeding speed of the polymer film of the base material at the time of continuous layering in this example was 0.1 m / min.
Other conditions are as follows. <Layering conditions> Applied power 1.0 kW Oxygen gas flow rate 27 sccm Layering drum surface temperature (layering temperature) 30 ° C. The gas flow rate unit sccm is a standard cubic cm per minute.

The measurement results of the ITO layer formed on the polyethylene terephthalate film under the above conditions are shown below.

<Results of ITO Layer Measurement> Layer Thickness 55 nm Layering Speed 5.5 nm · m / min Refractive Index (λ = 550 nm) 2.0 Sheet Resistance 10 ¹¹ Ω / sq <Device Used for ITO Layer Measurement> Layer Thickness Measurement : Ellipsometer (model number: UVISELTM, manufacturer: JOBIN YVON) Sheet resistance measurement: MCP-HT450 (maker: Mitsubishi Chemical Co., Ltd.) Refractive index measurement: Ellipsometer (model number: UVISELTM, manufacturer: JOBIN YVON) ITO shown above As the result of layer formation, stratification temperature 3
At 0 ° C., a uniform and highly insulating titanium oxide layer having a refractive index of 2.0 could be formed on the polyethylene terephthalate film at a layering rate of 5.5 nm · m / min. The ITO layer was a thin layer having high extinction coefficient of 0.003 at λ = 550 nm, as measured by an ellipsometer. In addition, after forming the ITO layer,
The polyethylene terephthalate film was in a good state without slight elongation or deformation. (Example 2) FIG.
An ITO layer was formed on a polyethylene terephthalate (PET) film having a thickness of 75 μm, which is a plastic film as a base material, by using the sputtering apparatus shown in FIG. The feeding speed of the polymer film of the base material at the time of continuous layering in this example was 0.1 m / min. Other conditions are as follows. <Layering Conditions> Applied power 1.0 kW Oxygen gas flow rate 90 sccm Layering drum surface temperature (layering temperature) 30 ° C. The measurement results of the ITO layer formed on the polyethylene terephthalate film are shown below.

<Results of ITO layer measurement> Layer thickness 14 nm Layering speed 1.4 nm · m / min Refractive index (λ = 550 nm) 2.0 Sheet resistance 10 ¹¹ Ω / sq or more <Device used for ITO layer measurement> Layer thickness Measurement: Ellipsometer (model number: UVISELTM, manufacturer: JOBIN YVON) Sheet resistance measurement: MCP-HT450 (maker: Mitsubishi Chemical Co., Ltd.) Refractive index measurement: Ellipsometer (model number: UVISELTM, manufacturer: JOBIN YVON) The formation temperature of ITO layer is 3
At 0 ° C., a uniform and highly insulating titanium oxide layer having a refractive index of 2.0 could be formed on the polyethylene terephthalate film at a layering rate of 1.4 nm · m / min. The ITO layer was a thin layer having high extinction coefficient of 0.003 at λ = 550 nm, as measured by an ellipsometer. In addition, after forming the ITO layer,
The polyethylene terephthalate film was in a good state without slight elongation or deformation.

From the above Examples 1 and 2, it was revealed that it is possible to form a thin layer (ITO layer) suitable for a laminate in the antireflection film on the substrate by using the sputtering method. . (Example 3) As shown in FIG. 1, a hard coat layer 3 on a polymer film 2 as a substrate, a medium refractive index layer 5 formed by a plasma CVD method, a high refractive index layer 6 formed by a sputtering method, A laminate 4 composed of the low refractive index layer 7 formed by the plasma CVD method was formed to prepare an antireflection film. The conditions for forming each layer are described below. <Polymer film (2)> Triacetyl cellulose thickness 80 μm <Hard coat layer (3)> UV curable resin PET-D31 (Dainichi Seika Kogyo Co., Ltd.)
Formed by coating UV curing conditions 480 mJ Thickness 6 μm <Medium refractive index layer (5)> A carbon-containing silicon oxide layer was formed by the plasma CVD apparatus shown in FIG. <High Refractive Index Layer (6)> The same ITO layer as in Example 1 was formed under the same conditions. <Low Refractive Index Layer (7)> A silicon oxide layer was formed by the plasma CVD apparatus shown in FIG.

The antireflection film formed under the above conditions is
The polymer film was in a good condition without any slight elongation or deformation. FIG. 5 shows the reflection spectral characteristics of the antireflection film produced under the above conditions. As shown in FIG. 5, the reflectance was low near 550 nm, which is easily sensed by humans, and the antireflection effect was good. At this time, the luminous reflectance was 0.3%, which was a good value.

The spectral reflectance was measured by the following device. Spectral reflectance measurement: Spectrophotometer (Model number: UV-3100P
C, manufacturer: Shimadzu Corporation) The film thickness of the laminated film formed in the above embodiment is
It was set so that the luminous reflectance was minimized in consideration of the optical characteristics of each layer. For example, in the medium refractive index layer, the high refractive index layer and the low refractive index layer shown in Example 2, the desired film thickness can be adjusted by adjusting the film feed speed when forming each thin layer using each device for forming the same. The film thickness is obtained.

[0086]

According to the antireflection film of the present invention, the laminate constituting the antireflection film of the present invention has a thin layer formed by the plasma CVD method and a thin layer formed by the sputtering method or the vapor deposition method. Since it is formed by stacking and, compared to forming all of the thin layers forming the laminated body by the sputtering method or the vapor deposition method, the formation speed can be increased, while the plasma CVD method Adhesion between the thin layers can be improved as compared with the case where all thin layers are formed.

Further, among the thin layers forming the laminate, the thin layer formed by the plasma CVD method is the low refractive index layer or the medium refractive index layer, and the thin layer formed by the sputtering method or the vapor deposition method is the high refractive index layer. When the low refractive index layer or the medium refractive index layer is formed by the plasma CVD method, the low refractive index layer or the medium refractive index layer does not cause any particular problem even if formed by the plasma CVD method (there is no problem in moist heat resistance). The formation speed can be increased, and when formed by the plasma CVD method, the refractive index may not be stable due to poor wet heat resistance. Only the high refractive index layer can be formed by the sputtering method or the vapor deposition method. The refractive index of the high refractive index layer can be stabilized.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of an antireflection film of the present invention.

FIG. 2 is a schematic diagram of a plasma CVD apparatus.

FIG. 3 is a schematic view of a sputtering apparatus.

FIG. 4 is a schematic cross-sectional view showing an example of the antireflection film of the present invention.

5 is a diagram showing reflection spectral characteristics of the antireflection film of Example 3. FIG.

[Explanation of symbols]

1, 1 '... Antireflection film 2, 2 '... Base material 3, 3 '... hard coat layer 4, 4 '... laminated body 5 ... Medium refractive index layer 6, 6 '... High refractive index layer 7, 7 '... low refractive index layer 20 ... Plasma CVD apparatus 30 ... DC sputtering device

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2K009 AA02 AA15 BB11 CC03 CC24                       DD04                 4F100 AA20C AA21D AA33D AT00A                       BA04 BA07 BA10A BA10D                       CC00B EH66D EJ61C GB07                       GB41 JK06 JK12B JL00                       JM02C JM02D JN06 JN18C                       JN18D YY00C

Claims (6)

[Claims] 1. An antireflection film comprising: a base material; a hard coat layer located on the base material; and a laminate formed on the hard coat layer and having a plurality of laminated thin layers, wherein: The body is formed by laminating a thin layer formed by a plasma CVD method and a thin layer formed by a sputtering method or a vapor deposition method, and an antireflection film. 2. Among the thin layers forming the laminate, the thin layer formed by plasma CVD is a low refractive index layer or medium refractive index layer, and the thin layer formed by sputtering or vapor deposition is It is a high refractive index layer, The antireflection film of Claim 1 characterized by the above-mentioned. 3. The low refractive index layer formed by the plasma CVD method has a refractive index of 1.40 to 1.46 (λ = 55).
0 nm), and infrared absorption due to C—H stretching vibration at 2800 to 3000 cm ⁻¹ , and 1200 to 14
The antireflection film according to claim 2 infrared absorption by Si-CH ₃ stretching vibration at 00cm ^-1, characterized in 0.1 cm ^-1 or less of the silica layer, respectively. 4. The layer structure of the laminate is formed from the hard coat layer side by a medium refractive index layer formed by a plasma CVD method, a high refractive index layer formed by a sputtering method or a vapor deposition method, and a plasma CVD method. The low-refractive-index layer as defined below, wherein the antireflection film according to claim 2 or 3. 5. The layer structure of the laminate is, from the hard coat layer side, a high refractive index layer formed by a sputtering method or a vapor deposition method, a low refractive index layer formed by a plasma CVD method, a sputtering method or a vapor deposition method. The high-refractive-index layer formed by the above method, the low-refractive-index layer formed by the plasma CVD method, and the antireflection film according to claim 2 or 3. 6. The low refractive index layer or the medium refractive index layer formed by the plasma CVD method is a silicon oxide layer,
The high refractive index layer formed by a sputtering method or a vapor deposition method is a titanium oxide layer or an ITO layer exhibiting a high resistance, and the reflection according to any one of claims 2 to 5. Prevention film.