JP2003276109A - Manufacturing method for transparent laminated film, transparent laminated film, and antireflection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a transparent laminated film preventing the pulverization of a silicon oxide layer when the silicon oxide layer is formed on a substrate material comprising a plastic film by a plasma CVD method to form a uniform silicone oxide thin film having a stable refractive index, and the transparent laminated film. <P>SOLUTION: When the transparent laminated film 1 is manufactured by forming the transparent oxide thin film 3 on the substrate material 2 comprising the plastic film by the plasma CVD method, inert gas is introduced into a reaction chamber in the plasma CVD method and, if an average free process (λ=kT/πpd<SP>2</SP>√2) of gas molecules of the whole of gas mixed with a raw material gas is set to a condition of 0.7-5 cm, the uniformity of the mixed gas in the reaction of the raw material gas and oxygen gas is enhanced by the inert gas and, as a result, discharge voltage is stabilized and the pulverization of the oxide thin film can be prevented. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicon oxide layer formed on a substrate made of a plastic film by plasma C
The present invention relates to a method for producing a transparent laminated film formed by the VD method and a transparent laminated film obtained by the method, and more particularly to an antireflection film having an antireflection film provided on a substrate.

[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 information such as characters, figures and the like is read through these transparent substrates, there is a drawback that when the light is reflected on the surface of the transparent substrate, it becomes difficult to read such information.

On the other hand, at present, in order to solve the above-mentioned drawbacks, a reflection formed of a base material, a hard coat layer, and a laminated body formed by laminating a plurality of thin layers having different refractive indexes from each other. By using an antireflection film and sticking the antireflection film on the surface of the transparent substrate, light reflection is prevented. A typical constitution of the antireflection film is indium tin oxide (tin-doped In ₂ O ₃
Then, a transparent conductive thin film such as ITO) is laminated,
Further, a low refractive index thin film having a refractive index lower than that of the transparent conductive thin film, for example, a thin film of SiO ₂ is formed on the transparent conductive thin film to prevent reflection.

[0004]

When a silicon oxide layer (silica layer) is formed as a thin film on a plastic film, by forming it by a plasma CVD method, the speed of film formation is significantly higher than that by a sputtering method or the like. Productivity has increased.
However, in the above plasma CVD method, when forming the silicon oxide layer on the base material in the reaction chamber, the source gas (silicon compound) and oxygen are bound to each other, and the silicon oxide thin film becomes fine particles. There is a problem that a uniform thin film cannot be obtained and the refractive index is not stable.

Therefore, according to the present invention, in order to solve the above problems, when a silicon oxide layer is formed by a plasma CVD method on a substrate made of a plastic film,
An object of the present invention is to provide a method for producing a transparent laminated film capable of forming a silicon oxide thin film having a uniform and stable refractive index by preventing the formation of fine particles in the silicon oxide layer and a transparent laminated film obtained thereby. Is.

[0006]

In order to solve the above-mentioned problems, the method for producing a transparent laminated film according to the present invention is characterized in that, in claim 1, a transparent oxide thin film is plasma-coated on a substrate made of a plastic film. In the method for producing a transparent laminated film formed by the CVD method, plasma CV is used.
Inert gas was introduced into the reaction chamber in method D, and the mean free path (λ = k) of the gas molecules of the entire gas mixed with the raw material gas was introduced.
Under the condition that T / πpd ² √2) is 0.7 cm or more and 5 cm or less, an oxide thin film is provided on a substrate, and the refractive index of the oxide thin film is 1.4 to 1.55 (wavelength λ = 550 nm). The surface roughness Ra is set to 3 nm or more and 30 nm or less. Further, as a second aspect, the transparent laminated film of the present invention is characterized in that a transparent oxide thin film is provided on a plastic film substrate by the method for producing a transparent laminated film according to the first aspect.

As a third aspect, the refractive index on the substrate is 1.5.
5 to 1.8 (wavelength λ = 550 nm) and a film thickness of 10 to 2
A silicon oxide layer having a thickness of 00 nm, a high refractive index layer having a refractive index of 1.8 or more (wavelength λ = 550 nm), and the oxide thin film according to claim 2 are laminated in this order. The oxide thin film according to claim 2, wherein the high refractive index layer, the refractive index is 1.4 to 1.55 (wavelength λ = 550 nm), and the film thickness is 10 to 200 nm on the base material. Laminated in this order, or on the substrate, the high refractive index layer,
The oxide thin film, the high refractive index layer, and the oxide thin film are laminated in this order.

As a fifth aspect, a hard coat layer is formed between the base material according to any one of the second to fourth aspects and a layer provided on the base material, that is, an antireflection film. It is characterized by being As claim 6, the claim 1 ~
5. The transparent laminated film described in any one of 5 above, wherein an antifouling layer is formed on the outermost surface of the antireflection film. Further, as a seventh aspect, the substrate according to any one of the first to sixth aspects is a uniaxially or biaxially stretched polyester film or a triacetyl cellulose film.

The transparent laminated film obtained by the above-mentioned manufacturing method is formed on a substrate made of a plastic film,
When forming a transparent oxide thin film by the plasma CVD method, an inert gas is introduced into the reaction chamber in the plasma CVD method, and the mean free path (λ = kT / πpd) of the gas molecules of the whole gas mixed with the source gas is introduced. ^{If 2} √2) is 0.7 cm or more and 5 cm or less, the inert gas improves the uniformity of the mixed gas in the reaction between the raw material gas and the oxygen gas,
As a result, the discharge voltage can be stabilized and the oxide thin film can be prevented from becoming fine particles. As a result, it is possible to form a uniform and stable oxide thin film having a low refractive index on the base material, and to stack the thin oxide film with a high refractive index layer to sufficiently reduce external light reflection and to provide a transparent laminate having an antireflection function. A film, that is, an antireflection film can be manufactured while maintaining stable quality.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. FIG. 1 shows one embodiment of the transparent laminated film 1 of the present invention, in which a substrate 2 made of a plastic film has a refractive index of 1.4 to 1.55 (wavelength λ = 55.
0 nm) and the surface roughness Ra is 3 nm or more and 30 nm or less, and the transparent oxide thin film 3 is provided. This oxide thin film 3 is a low refractive index layer. 2 shows another embodiment which is the transparent laminated film 1 of the present invention, in which the refractive index is 1.55 to 1.55 on the substrate 2 made of a plastic film.
1.8 (wavelength λ = 550 nm) and a film thickness of 10 to 200
nm, a high-refractive index layer 5 having a refractive index of 1.8 or more (wavelength λ = 550 nm), and a refractive index of 1.
4 to 1.55 (wavelength λ = 550 nm) and a surface roughness Ra of 3 nm or more and 30 nm or less are laminated in this order. The silicon oxide layer 4 is a medium refractive index layer. In FIG. 1, the transparent laminated film 6 having only the oxide thin film 3 is formed on the base material 2, but in FIG.
On top, a silicon oxide layer 4, a high refractive index layer 5 and an oxide thin film 3
A transparent laminated film 6 made of is provided.

The low refractive index layer, the medium refractive index layer, and the high refractive index layer are named by distinguishing the refractive indices of the thin films constituting the transparent laminated film from the relative differences. . In the present invention, the low refractive index layer is a layer having a relatively low refractive index and has a refractive index of less than 1.55 nm. The high refractive index layer is a relatively high layer and has a refractive index of 1.8 or more. The medium refractive index layer has a refractive index intermediate between those of the low refractive index layer and the high refractive index layer, and is 1.55 or more and 1.8.
It has a refractive index of less than. However, all the refractive indexes of the present invention are measured with light having a wavelength of 550 nm. FIG. 3 shows another embodiment of the transparent laminated film 1 of the present invention, in which a high refractive index layer 5 and a refractive index of 1.4 to 1.55 (wavelength λ are formed on a substrate 2 made of a plastic film.
= 550 nm) and the oxide thin film 3 having a thickness of 10 to 200 nm are laminated in this order, and a transparent laminated film (antireflection film) including the high refractive index layer 5 and the oxide thin film 3 on the base material 2.
6 is provided.

FIG. 4 shows another embodiment of the transparent laminated film 1 of the present invention, in which a high refractive index layer 5, an oxide thin film 3 and a high refractive index layer 5 are formed on a substrate 2 made of a plastic film. The oxide thin film 3 is laminated, and the high refractive index layer 5 and the oxide thin film 3 are repeatedly formed twice. In this case, a transparent laminated film (antireflection film) 6 composed of four layers of the high refractive index layer 5, the oxide thin film 3, the high refractive index layer 5, and the oxide thin film 3 is provided on the base material 2.

FIG. 5 shows another embodiment of the transparent laminated film 1 of the present invention, in which a hard coat layer 7, a high refractive index layer 5 and an oxide thin film 3 are sequentially formed on a substrate 2 made of a plastic film. In other words, it is the transparent laminated film 1 in which the antireflection film 6 including the high refractive index layer 5 and the oxide thin film 3 is provided on the base material 2 with the hard coat layer 7 interposed therebetween. FIG. 6 shows another embodiment of the transparent laminated film 1 of the present invention, in which a silicon oxide layer 4, a high refractive index layer 5, an oxide thin film 3 and an antifouling layer 8 are provided on a substrate 2 made of a plastic film. It is sequentially formed, and the silicon oxide layer 4, the high refractive index layer 5, and the antireflection film 6 including the oxide thin film 3 and the antifouling layer 8 are sequentially provided on the base material 2.

First, each layer constituting the transparent laminated film of the present invention will be described. (Substrate) As the substrate 2 of the transparent laminated film of the present invention, a plastic film is used and transparency is required.
For example, triacetyl cellulose film, diacetyl cellulose film, acetate butyrate cellulose film, polyether sulfone film, polyacrylic film, polyurethane film, polyester film, polycarbonate film, polysulfone film, polyether film, trimethylpentene film, poly Examples thereof include ether ketone film, acrylonitrile film, methacrylonitrile film and the like. Furthermore, a colorless and transparent film can be more preferably used. Among them, a uniaxially or biaxially stretched polyester film is preferably used because it has excellent transparency and heat resistance, and triacetyl cellulose is also preferably used because it has no optical anisotropy. The thickness of the plastic film is usually 6 μm
Those having a thickness of about 188 μm are preferably used.

(Oxide thin film) In the transparent laminated film of the present invention, a transparent oxide thin film 3 is provided by a plasma CVD method on a substrate made of a plastic film, and the oxide thin film has a refractive index of 1.4 to 1.55 (wavelength λ = 550 nm), surface roughness Ra of 3 nm or more, 30 n
m or less. Therefore, this oxide thin film is a low-refractive index layer, and suppresses the point that the oxide thin film is likely to become fine particles when the raw material gas (silicon compound) and oxygen are combined during the film formation by the plasma CVD method. It was formed. In the present invention, as a raw material gas for forming the silica film, silane, disilane, hexamethyldisiloxane (H
MDSO), tetramethyldisiloxane (TMDS)
O), methyltrimethoxysilane (MTMOS), methylsilane, dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, tetramethoxysilane, octamethylcyclotetrasiloxane,
It is possible to use a Si-based compound such as tetraethoxysilane. Although a method for forming the oxide thin film will be described later, examples of the oxide thin film that can be used include a silicon oxide layer, a magnesium fluoride layer, and a silicon oxyfluoride layer. The oxide thin film does not necessarily have to be a single layer, and a plurality of different layers are laminated to form a layer structure in which the refractive index is 1.4 to 1.55 as a whole, so that the laminated film is oxidized. It is also possible to use a thin film.

The oxide thin film used in the present invention is preferably a silicon oxide layer for the following reasons. It is relatively easy to set the refractive index of the silicon oxide layer to 1.4 to 1.55, and even under the condition of the plasma CVD method, it is excellent in moisture resistance and heat resistance, and a thin film having a stable refractive index can be produced. This is because it can be formed well. The composition of the silicon oxide layer does not have to be simply SiOx, but may be a silicon oxide layer containing carbon (SiOxCy).
By including carbon in the silicon oxide layer as described above, the refractive index can be more easily adjusted to a desired range.

The thickness of the oxide thin film is about 10 to 1000 nm, preferably 10 to 200 nm. If the film thickness is too small, it becomes impossible to exert the antireflection effect by laminating with a layer having a different refractive index, and if the film thickness is too large,
Substrate deformation and layer peeling may occur due to layer pressure, which is not preferable. Usually, when the transparent laminated film of the present invention is used as an antireflection film, it is desirable that the above oxide thin film be the uppermost layer and that a layer different from the refractive index of the oxide thin film be laminated.

(Silicon oxide layer) The transparent laminated film of the present invention comprises a silicon oxide layer 4 as a medium refractive index layer on a substrate.
Can be used in combination with a high refractive index layer or a low refractive index layer to form an antireflection film. However, it is preferable to stack the silicon oxide layer, the high-refractive index layer, and the low-refractive index layer in this order on the base material because light reflection can be efficiently prevented. As this silicon oxide layer, a silicon oxide layer containing few impurities, a carbon-containing silicon oxide layer, or A
l ₂ O ₃ , SiN, SiON, ZrO ₂ , SiO ₂ , Zn
An example is one in which fine particles of O ₂ are dispersed in a silicon oxide layer. The silicon oxide layer does not necessarily have to be a single layer, and a plurality of different layers are laminated to form a layer structure having a refractive index of 1.5 to 1.8 as a whole to oxidize the laminated film. It can also be a silicon layer.

The method for forming the silicon oxide layer is plasma C
The silicon oxide layer can be formed by a VD method, an evaporation method, a sputtering method, or the like, and the thickness of the silicon oxide layer is 10 to 10
It is about 00 nm, preferably in the range of 10 to 200 nm. If the film thickness is too small, almost no antireflection effect can be expected by laminating with a layer having a different refractive index, and if the film thickness is too large, substrate deformation or layer peeling may occur due to layer pressure. Not preferable. The silicon oxide layer of the medium refractive index layer used in the present invention has a refractive index of 1.55 to
1.8 (wavelength λ = 550 nm) and a film thickness of 10 to 200
It is preferably nm.

(High Refractive Index Layer) In the transparent laminated film of the present invention, the high refractive index layer 5 can be used as a constituent element of the transparent laminated film (antireflection film) provided on the substrate, and the low refractive index described above is used. By using it together with the oxide thin film which is the refractive index layer, it is possible to efficiently prevent the reflection of light due to the difference in the respective refractive indexes. The position of the high refractive index layer in the transparent laminated film is not particularly limited, but it is preferable that the low refractive index layer and the high refractive index layer are in contact with each other in order to efficiently prevent light reflection. Therefore, it is preferable to provide it under the low refractive index layer.

The thin film that can be used as the high refractive index layer has transparency in the visible light region and has a refractive index of 1.
There is no particular limitation as long as it is a thin film having a thickness of 80 or more (λ = 550 nm). Specific examples of the high refractive index layer include titanium oxide, ITO (indium / tin oxide) layer, Y ₂ O ₃ layer, In ₂ O ₃ layer, Si ₃ N ₄ layer and SnO _2.
Layer, ZrO ₂ layer, HfO ₂ layer, Sb ₂ O ₃ layer, Ta ₂ O ₅ layer,
Examples thereof include a ZnO layer and a WO ₃ layer. Among them, it is particularly preferable to use titanium oxide or an ITO layer having high resistance. The method for forming the high refractive index layer is a plasma CV.
It can be formed by the D method, the vapor deposition method, the sputtering method, or the like, and the film thickness of the high refractive index layer is about 5 to 300 nm,
The range of 10 to 150 nm is preferable. If the film thickness is too small, almost no antireflection effect can be expected by laminating with a layer having a different refractive index, and if the film thickness is too large, substrate deformation or layer peeling may occur due to layer pressure. Not preferable.

(Hard Coat Layer) The hard coat layer 7 is
It is formed for the purpose of imparting strength to the transparent laminated film of the present invention. The material for forming the hard coat layer is a material that is transparent in the visible light region like the plastic film substrate, and it is necessary that the transparent laminated film can have strength.
It preferably has a hardness of "H" or more in a pencil hardness test according to JIS K5400.

Specifically, it is preferable to use a thermosetting resin and / or an ionizing radiation curable resin, and more specifically, a resin having an acrylate-based functional group, for example,
Relatively low molecular weight polyester, polyether, acrylic resin, epoxy resin, polyurethane, alkyd resin, spiro acetal resin, polybutadiene, polythiol polyene resin, (meth) acrylate of polyfunctional compounds such as polyhydric alcohol (hereinafter, acrylate And methacrylate are referred to as (meth) acrylate) and ethyl (meth) acrylate which is a reactive diluent, ethylhexyl (meth) acrylate, styrene, vinyltoluene, N-vinylpyrrolidone, etc. Monofunctional monomers as well as polyfunctional monomers such as trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di Those containing a relatively large amount of (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, etc. used.

Further, when the above-mentioned ionizing radiation curable resin is used as an ultraviolet curable resin, photopolymerization initiators such as acetophenones, benzophenones, Michler benzoyl benzoate, α-amyloxime can be used as photopolymerization initiators. 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 film thickness of the hard coat layer as described above is usually in the range of 1 to 30 μm, and the forming method thereof may be a usual coating method, and is not particularly limited. If the hard coat layer is too thin, the hardness of each layer formed on it cannot be maintained,
On the other hand, if it is too thick, the flexibility of the entire transparent laminated film is reduced, and it takes time to cure, leading to a reduction in production efficiency.

(Antifouling Layer) In the transparent laminated film of the present invention, an antifouling layer 8 for preventing contamination on the upper surface of the antireflection film may be provided as the uppermost layer. The antifouling layer is formed in order to prevent dust and dirt from adhering to the antireflection film arranged on the front surface of the display panel, or to make it easy to remove even if adhered. Specifically, a surfactant such as a fluorine-based surfactant, a coating material containing a fluorine-based resin, a release agent such as silicone oil, or a wax is applied very thinly within a range that does not deteriorate the antireflection function. Wipe off. The antifouling layer may be formed as a permanent layer, or may be applied and formed whenever necessary.
The thickness of the antifouling layer is preferably about 1 to 10 nm. The forming method can use a usual coating method and is not particularly limited.

(Manufacturing Method of Transparent Laminated Film) The manufacturing method of the transparent laminated film in the present invention comprises forming a transparent oxide thin film on a base material made of a plastic film by a plasma CVD method. An inert gas is introduced into the reaction chamber, and the mean free path (λ = kT / π of the gas molecules of the whole gas mixed with the source gas is
Under the condition that pd ² √2) is 0.7 cm or more and 5 cm or less,
An oxide thin film is provided on a substrate, the oxide thin film has a refractive index of 1.4 to 1.55 (wavelength λ = 550 nm), and a surface roughness R.
a is set to 3 nm or more and 30 nm or less. Mean free path of gas molecule defined above (λ = kT / πpd ² √2)
In the equation, λ is the mean free path, k is the Boltzmann constant, T is the temperature of the gas, p is the pressure of the gas, and d is the molecular diameter (diameter) of the gas.

One embodiment of the method for producing the transparent laminated film will be described with reference to FIG. First,
The web-shaped transfer target (base material) 2 is unwound from the unwinding portion 10 and introduced into the plasma CVD reaction chamber 13 in the vacuum container 12. The entire reaction container 12 is exhausted by the vacuum pump 14. At the same time, the reaction chamber 13
Is a gas that is obtained by gasifying a raw material such as a silicon compound of an oxide thin film at a specified flow rate from the gas inlet 15, an oxygen gas, and a gas that is inert to a raw material gas of an oxide thin film such as helium, neon, or argon. Is supplied to the inside of the reaction chamber 13,
It is always filled with these mixed gases at a constant pressure.

Next, the transfer-receiving member 2 unwound from the substrate unwinding section 10 and introduced into the reaction chamber 13 is wound around the film-forming drum 18 through the reversing roll 16 and is transferred to the film-forming drum 18. It is fed in the direction of the reversing roll 17 in synchronization with the rotation. At this time, the temperature of the film forming drum 18 can be controlled, and at this time, the surface temperature of the transferred body 2 and the surface temperature of the film forming drum 18 are substantially equal. Therefore, the surface temperature of the transferred material 2 on which the oxide thin film is deposited during plasma CVD, that is, the film formation temperature of plasma CVD can be controlled arbitrarily. In this example, the film forming temperature when the oxide thin film 3 is formed on the transferred object 2 by plasma CVD is indicated by the surface temperature of the film forming drum 18 at that time. The surface temperature of the transferred material 2, that is, the film formation temperature of plasma CVD is preferably controlled to a temperature within the range of -10 to 150 ° C.

Between the electrode 19 and the film-forming drum 18,
An RF voltage is applied by the power supply 20. At this time, the frequency of the power supply is not limited to radio waves, and it is possible to use an appropriate frequency from direct current to microwave. And
By applying an RF voltage between the electrode 19 and the film-forming drum 18, plasma 21 is generated around these electrodes. Then, in the plasma 21, the raw material gas such as a silicon compound of the oxide thin film and the oxygen gas react with each other in a mixed state, and the raw material such as a silicon compound is wound around the film-forming drum 18 to be transferred. Deposited on the body 2, an oxide thin film 3 is formed. After that, the transferred body 2 on the surface of which the oxide thin film 3 is formed passes through the reversing roll 17 and is wound up by the base material winding section 11.

Transfer target (plastic film base material)
When the oxide thin film is formed on the above, in the reaction chamber,
Although the raw material gas and oxygen are bound to each other, the silicon oxide thin film is easily atomized, but since the inert gas is introduced into the reaction chamber in the present invention, the inert gas is a mixed gas in the reaction between the raw material gas and the oxygen gas. It is possible to improve the uniformity, stabilize the discharge voltage as a result, and prevent the oxide thin film from becoming fine particles. At that time, the mean free path (λ = kT) of the gas molecules in the entire gas in the reaction chamber is adjusted by adjusting each ratio in the mixed gas of the raw material gas, the oxygen gas, and the inert gas.
/ Πpd ² √2) within the range of 0.7 cm or more and 5 cm or less, the refractive index on the substrate is 1.4 to 1.55.
(Wavelength λ = 550 nm), surface roughness Ra is 3 nm or more,
An oxide thin film having a thickness of 30 nm or less can be easily formed.

As described above, the oxide produced by the chemical reaction of the source gas and the oxygen gas by the plasma 21 in the presence of the inert gas is cooled to an appropriate temperature by the film forming drum 18. Since the oxide thin film is formed by depositing on the transfer body 2, the oxide thin film 3 can be formed without exposing the transferred body 2 to a high temperature and stretching, deforming, or curling. Further, in the above plasma CVD method,
By controlling the flow rate and pressure of the material gas, the discharge conditions, and the feed speed of the transferred body 2, the refractive index, the film thickness, etc. of the oxide thin film 3 to be formed can be controlled in a wide range. A film having the following optical characteristics can be obtained. The plasma CVD apparatus 9 used in the present invention is not particularly limited as long as it can control the temperature of the transferred body, and the power supply frequency and the plasma generation method are also not particularly limited.

The raw material of the oxide thin film is evaporated in the liquid vaporizer and introduced into the reaction chamber in the form of raw material gas. Oxygen gas and inert gas are also introduced into the reaction chamber. This oxygen gas plays a role as a reaction gas for reacting with the source gas to generate an oxide thin film. Further, the inert gas improves the homogeneity of the mixed gas in the reaction between the raw material gas and the oxygen gas, and consequently stabilizes the discharge voltage and prevents the oxide thin film from becoming fine particles. The flow rate ratio of oxygen gas and source gas (oxygen gas / source gas) is preferably 0.5 to 10. If the proportion of oxygen gas is smaller than this range, it becomes difficult to obtain an oxide thin film having a low refractive index.
If the flow rate ratio of oxygen gas is large, fine particles of the oxide thin film are likely to be generated. Examples of the inert gas introduced into the reaction chamber include gases such as helium, neon, and argon, which are inactive with the raw material gas for the oxide thin film.
The flow ratio of the inert gas to the oxygen gas (inert gas / oxygen gas) is preferably about 0.05 to 0.7.
If the ratio of the inert gas is smaller than this range, the function of improving the uniformity of the mixed gas by the inert gas, stabilizing the discharge voltage, and preventing the oxide thin film from becoming fine particles becomes insufficient. Further, when the flow rate ratio of the inert gas is large, the oxygen gas concentration is relatively lowered, the reactivity between the source gas and the oxygen gas is lowered, and it becomes difficult to form the CVD thin film.

The preferred pressure in the reaction chamber is 1 Torr or less. This is because when the pressure is higher than 1 Torr, the mechanical strength of the formed oxide thin film is deteriorated. The partial pressure of the source gas is preferably 10 ^-1 Torr or less. Partial pressure of source gas is 10 ^-1 To
If it is larger than rr, there arises a problem that the raw material of the oxide thin film is liquefied in the reaction chamber. Since the temperature of the film forming drum can be controlled, the surface temperature of the transfer target on which the oxide thin film is deposited during plasma CVD, that is, plasma C
The VD film formation temperature can be controlled arbitrarily. The film forming temperature is preferably -10 to 150 ° C. If this temperature is lower than -10 ° C, the refractive index of the formed oxide thin film is lowered, which is not preferable. Also,
When the film forming temperature is higher than 150 ° C., the temperature is higher than the heat deformation temperature of the plastic film of the base material usable in the present invention, and problems such as elongation, deformation and curling during film formation occur, which is not preferable. In addition, as an anti-reflection film, when high quality is required in which slight waviness, deformation, and elongation are not allowed, or when the plastic film of the base material is
If the thickness is less than 0 μm and it is susceptible to thermal expansion and deformation,
It is particularly desirable to carry out plasma CVD film formation of an oxide thin film at a temperature of from -10 ° C to Tg of the plastic film or lower.

In the example shown in FIG. 7, the transfer target is brought into close contact with the film forming drum, and the temperature of the transfer target is controlled by controlling the temperature of the film forming drum. The method is not limited, and if the method can control the temperature of the transferred material when the film is formed by plasma CVD, for example, the temperature of the transferred material is controlled by controlling the ambient temperature in the reaction chamber. The method and the method of feeding the transfer target to a predetermined temperature in advance and then feeding it into the reaction chamber are not particularly limited. The transparent laminated film of the present invention,
Although the oxide thin film that is the low refractive index layer is formed by the plasma CVD method described above, a hard coat layer can be formed in advance on the base material by coating or the like, and another thin film can be formed on the base material. If necessary, a medium refractive index layer or a high refractive index layer is formed by a plasma CVD method, a vapor deposition method, a sputtering method, or the like. Furthermore, an antifouling layer can be formed on the outermost surface of the transparent laminated film by coating or the like.

[0037]

EXAMPLES The present invention will be described in more detail by way of examples. (Example 1) Using the apparatus of FIG.
75 μm thick polyethylene terephthalate film
Silicon oxide layer on the Talate (PET) film
An oxide thin film was formed. Liquid vaporizer as raw material gas
Using HMDSO vaporized at 150 ° C using
Gas and helium gas are mixed to react from the raw material gas inlet
It was introduced indoors. HMDSO, oxygen gas, helium gas
The flow rate of each gas is as follows.
Mean free path (λ = kT / πpd ²√2)
Was 0.7 cm or more and 5 cm or less. Specifically
Has an average free path of 3 cm for all gas molecules.
It was The plasma CVD apparatus of FIG. 7 used this time is capacitively coupled.
Type, 13.56MHz RF power supply as high frequency power supply
Using. Also, the plastic film of the substrate during continuous film formation
The feed rate of rum is 1 m / min. Other conditions
Is described below.

[0038] <Film forming conditions> Applied power 2kW HMDSO (raw material gas) 1 slm Oxygen gas flow rate 1 slm Helium gas flow rate 0.4 slm Surface temperature of film forming drum (film forming temperature) 30 ° C

The above gas flow rate unit sccm is stan
dard cubic liter per minute
It is e. Various measurement results of the film thickness, refractive index, surface roughness, etc. of the silicon oxide thin film which is an oxide thin film formed on the polyethylene terephthalate film under the above conditions are shown below.

[0040] <Results of oxide thin film measurement> Film thickness 240nm Deposition rate 240nm ・ m / min Refractive index (λ = 550 nm) 1.45 Surface roughness Ra 10nm

<Apparatus used for measuring oxide thin film> Ellipsometer model number UVISEL ^™ manufacturer JOBIN YVON Refractive index measurement Ellipsometer model number UVISEL ^™ manufacturer JOBIN YVON Surface roughness measurement Nanopixmaker Seiko Instruments

As shown in the above measurement results of the oxide thin film by the plasma CVD method, at the film forming temperature of 30 ° C., a uniform film having a refractive index of 1.45 does not become fine particles, and the film forming rate is 240 nm · m / It could be formed on a polyethylene terephthalate film in min. In addition, the polyethylene terephthalate film has no slight elongation or deformation,
It was in good condition.

Example 2 Using the apparatus shown in FIG. 7, a substrate
75 μm thick polyester film
Oxidation on the ethylene film
An oxide thin film that is a con layer was formed. As raw material gas
Is HMDS vaporized at 150 ° C using a liquid vaporizer.
O 2 is used as a raw material gas by mixing oxygen gas and argon gas
It was introduced into the reaction chamber through the inlet. HMDSO, oxygen gas
Flow rate of argon gas and argon gas is as follows.
Mean free path (λ = kT) of all gas molecules in the reaction chamber
/ Πpd ²√2) for conditions of 0.7 cm or more and 5 cm or less
did. Specifically, the mean free path of gas molecules in the entire gas
Was 4 cm. In addition, the plaster of the substrate during continuous film formation
The feed speed of the quick film is 1 m / min. So
Other conditions of are described below.

[0044] <Film forming conditions> Applied power 1.0kW HMDSO (raw material gas) 1 slm Oxygen gas flow rate 1 slm Argon gas flow rate 0.4 slm Surface temperature of film forming drum (film forming temperature) 30 ° C

The above gas flow rate unit sccm is stan
dard cubic liter per minute
It is e. Various measurement results of the film thickness, refractive index, surface roughness, etc. of the silicon oxide thin film which is an oxide thin film formed on the polyethylene terephthalate film under the above conditions are shown below.

[0046] <Results of oxide thin film measurement> Film thickness 220nm Deposition rate 220nm ・ m / min Refractive index (λ = 550 nm) 1.46 Surface roughness Ra 10nm

<Apparatus used for measuring oxide thin film> Film thickness measurement Ellipsometer model number UVISEL ^™ maker JOBIN YVON Refractive index measurement Ellipsometer model number UVISEL ^™ manufacturer JOBIN YVON Surface roughness measurement Nanopixmaker Seiko Instruments Inc.

As shown in the above measurement results of the oxide thin film by the plasma CVD method, at the film forming temperature of 30 ° C., a uniform film having a refractive index of 1.46 does not become fine particles, and the film forming rate is 220 nm · m / m. It could be formed on a polyethylene terephthalate film in min. In addition, the polyethylene terephthalate film has no slight elongation or deformation,
It was in good condition.

(Example 3) A hard coat layer, a medium refractive index layer, a high refractive index layer, and
A low refractive index layer was formed to produce a transparent laminated film, that is, an antireflection film. The conditions for forming each layer are as follows.

<Plastic film> Triacetyl cellulose thickness 80μm

<Hard Coat Layer> Ultraviolet Curing Resin PET-D31 (Dainichi Seika Kogyo Co., Ltd.)
It was formed by coating. UV curing conditions 480 mJ Thickness 6 μm

<Medium Refractive Index Layer> A carbon-containing silicon oxide layer was formed by a plasma CVD method. Refractive index 1.55 to 1.8 (wavelength λ = 550 nm)

<High Refractive Index Layer> The ITO layer was formed by sputtering. Refractive index is 1.85 (wavelength λ = 550 nm)

<Low Refractive Index Layer> A silicon oxide layer was used in Example 1.
Similar to the formation of the oxide thin film in (1), it was formed by the plasma CVD method.

The transparent laminated film formed under the above conditions is
There was no slight stretch or deformation of the plastic film. The reflection spectral characteristics of the transparent laminated film prepared under the above conditions are shown in FIGS. From Figure 8, it is easier for humans to perceive 5
The reflectance was low in the vicinity of 50 nm, and the antireflection effect was good. At this time, the luminous reflectance was 0.3%, which was a sufficient value as an antireflection film. Further, as shown in FIG. 9, the transmittance was high in the vicinity of 550 nm, which is easily perceived by humans, and no cloudiness was visually observed.

The spectral reflectance and the transmittance were measured by the following devices. Spectral reflectance measurement Spectrophotometer Model number UV-3100PC Manufacturer Shimadzu

The film thickness of the laminated film formed in the above embodiment was set so as to minimize the luminous reflectance in consideration of the optical characteristics of each layer. For example, in the high refractive index layer and the low refractive index layer shown in Example 3, the desired film thickness is obtained by adjusting the film feed speed when forming each layer.

[0058]

The transparent laminated film of the present invention is produced by plasma CVD when a transparent oxide thin film is formed on a substrate made of a plastic film by the plasma CVD method.
Inert gas is introduced into the reaction chamber in the method, and the mean free path (λ = kT) of all gas molecules mixed with the raw material gas
/ Πpd ² √2) is 0.7 cm or more and 5 cm or less, the inert gas improves the uniformity of the mixed gas in the reaction between the raw material gas and the oxygen gas, and as a result stabilizes the discharge voltage, It was possible to prevent atomization of the oxide thin film. As a result, it is possible to form a uniform and stable oxide thin film having a low refractive index on the base material, and to stack the thin oxide film with a high refractive index layer to sufficiently reduce external light reflection and to provide a transparent laminate having an antireflection function. A film, that is, an antireflection film can be manufactured while maintaining stable quality.

[Brief description of drawings]

FIG. 1 is a schematic view showing one embodiment of a transparent laminated film of the present invention.

FIG. 2 is a schematic view showing another embodiment of the transparent laminated film of the present invention.

FIG. 3 is a schematic view showing another embodiment of the transparent laminated film of the present invention.

FIG. 4 is a schematic view showing another embodiment of the transparent laminated film of the present invention.

FIG. 5 is a schematic view showing another embodiment of the transparent laminated film of the present invention.

FIG. 6 is a schematic view showing another embodiment of the transparent laminated film of the present invention.

FIG. 7 is a schematic diagram of a plasma CVD apparatus.

FIG. 8: Reflection spectral characteristics of Example 3

FIG. 9: Transmission spectral characteristics of Example 3

[Explanation of symbols]

1 Transparent laminated film 2 Plastic film substrate 3 Transparent oxide thin film 4 Silicon oxide layer 5 High refractive index layer 6 Antireflection film or transparent laminated film 7 Hard coat layer 8 Antifouling layer 9 Plasma CVD equipment 10 Base material unwinding section 11 Base material winding section 12 Vacuum container 13 Reaction chamber 14 Vacuum pump 15 gas inlet 16 reverse roll 17 Reverse Roll 18 Film forming drum 19 electrodes 20 power supplies 21 plasma

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 12, 2003 (2003.3.1)
2)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title: Method for producing transparent laminated film, transparent laminated film and antireflection film

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

Therefore, according to the present invention, in order to solve the above problems, when a silicon oxide layer is formed by a plasma CVD method on a substrate made of a plastic film,
To provide a method for producing a transparent laminated film capable of forming a silicon oxide thin film having a uniform and stable refractive index by preventing the formation of fine particles in a silicon oxide layer, and a transparent laminated film and an antireflection film obtained thereby. It is intended.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

As a fifth aspect, a hard coat layer is formed between the base material according to any one of the second to fourth aspects and a layer provided on the base material, that is, an antireflection film. It is characterized by being As claim 6, the claim 1
5. The transparent laminated film described in any one of 5 above, wherein an antifouling layer is formed on the outermost surface of the antireflection film. Furthermore, as a seventh aspect, the substrate according to any one of the first to sixth aspects is a uniaxially or biaxially stretched polyester film or a triacetyl cellulose film. Antireflection film of the present invention
Is described in any one of claims 1 to 7 as claim 8.
The transparent laminated film to be placed is an antireflection film
Is characterized by.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2K009 AA04 AA05 AA06 AA07 AA15                       BB24 CC03 CC26 CC42 CC47                       DD04 DD09 EE05                 4F100 AA17B AA17D AA20B AJ05A                       AK01A AK41A AK42 AT00A                       BA02 BA05 BA07 BA10A                       BA10B EH66B EJ38A GB41                       JB14 JK14B JL06B JN01B                       JN18B JN18C JN18E JN30                       YY00B                 4K030 BA01 BA10 BA11 BA17 BA20                       BA21 BA22 BA40 BA42 BA44                       BB12 CA07 CA12 FA03

Claims (7)

[Claims] 1. A method for producing a transparent laminated film, which comprises forming a transparent oxide thin film on a substrate made of a plastic film by a plasma CVD method.
Inert gas was introduced into the reaction chamber in method D, and the mean free path (λ = k) of the gas molecules of the entire gas mixed with the raw material gas was introduced.
Under the condition that T / πpd ² √2) is 0.7 cm or more and 5 cm or less, an oxide thin film is provided on a substrate, and the refractive index of the oxide thin film is 1.4 to 1.55 (wavelength λ = 550 nm). The method for producing a transparent laminated film, wherein the surface roughness Ra is 3 nm or more and 30 nm or less. 2. A transparent laminated film comprising a transparent oxide thin film provided on a plastic film substrate by the method for producing a transparent laminated film according to claim 1. 3. A silicon oxide layer having a refractive index of 1.55 to 1.8 (wavelength λ = 550 nm) and a film thickness of 10 to 200 nm on a substrate, a refractive index of 1.8 or more (wavelength λ = 550 nm).
nm) and the oxide thin film according to claim 2 are laminated in this order. 4. A high refractive index layer having a refractive index of 1.4 on a substrate.
~ 1.55 (wavelength λ = 550 nm) and film thickness is 10-2
The oxide thin film having a thickness of 00 nm is laminated in this order, or the high refractive index layer, the oxide thin film, the high refractive index layer and the oxide thin film are laminated in this order on a substrate. A transparent laminated film. 5. The hard coat layer is formed between a base material and a layer provided on the base material, that is, an antireflection film, according to any one of claims 2 to 4. The transparent laminated film described. 6. The antifouling layer is formed on the outermost surface of the antireflection film of the transparent laminated film.
The transparent laminated film described in any one of 1 to 5. 7. The transparent laminated film according to claim 1, wherein the base material is a uniaxially or biaxially stretched polyester film or a triacetyl cellulose film.