JP2003297262A - Thin film, method of forming thin film, and reflection reducing film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film, in which coexistence of a low refractive index and abrasion-proof property is possible, method of forming the thin film, and a reflection reducing film. <P>SOLUTION: The thin film formed on a base material has detailed unevenness on the outermost surface layer. The average interval of the unevenness, which is specified by JIS B 0601, is 10 nm or more and 400 nm or less, and the arithmetic mean roughness is 10 nm or more and 100 nm or less. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thin film formed on a substrate, a thin film forming method for forming the thin film, and an antireflection film.

[0002]

2. Description of the Related Art Cathode tube display (CRT), plasma display panel (PDP), liquid crystal display (LCD)
In such an image display device, an antireflection film that reduces the reflectance by using the principle of optical interference is arranged on the outermost surface of the display in order to prevent the deterioration of contrast and the reflection of an image due to the reflection of external light. There is. Examples of this antireflection film include a single-layer film in which one film having a low refractive index is formed on the surface of the base material, and a multilayer film in which films having different refractive indexes are laminated. In each of these single-layer films and multilayer films, it is effective to suppress reflection on the outermost surface by forming a film having a low refractive index on the outermost surface layer. Also known is a graded film formed so that the refractive index gradually changes from the interface with air in the film thickness direction, but in this case as well, the refractive index gradually decreases from the inside toward the outermost surface. Composed of materials.

By the way, as a material having a low refractive index, a material having a refractive index of 1.3 or more in the visible light range, such as a fluorine compound or silicon oxide, or a resin having a refractive index of about 1.5 is used as a material. It is known that the material dispersed in, and the low refractive index material used for the antireflection film is
It is said that it is desirable to be close to the refractive index (1.0) of air. As a method of forming such an ultra-low refractive index film, for example, JP-A-6-3501 and JP-A-9-28
As described in Japanese Patent No. 8201, it is known to form a film having an intermediate refractive index between air and solid by providing holes in the film.

[0004]

However, as described above, the antireflection film having pores in the film has pores although the refractive index decreases as the proportion of pores in the film increases. The more it has, the more it leads to deterioration of the hardness of the film itself, and the scratch resistance required for the outermost surface layer becomes poor.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a thin film, a thin film forming method, and an antireflection film that can achieve both low refractive index and scratch resistance.

[0006]

In order to solve the above-mentioned problems, the invention of claim 1 is a thin film formed on a substrate, wherein the outermost surface layer has fine irregularities, and JIS B 060
The average interval of the unevenness defined by 1 is 10 nm or more and 400 n
m or less and the arithmetic mean roughness is 10 nm or more and 10
It is characterized by being 0 nm or less.

According to a second aspect of the invention, in the thin film according to the first aspect, an antifouling layer is formed on the surface of the outermost surface layer.

The invention of claim 3 is a method for forming a thin film according to claim 1 or 2 on a substrate, which is formed by applying a coating solution on the substrate and drying. It is characterized in that it is formed by any one of a coating method, a PVD method and a CVD method.

According to a fourth aspect of the present invention, in the thin film forming method according to the third aspect, the CVD method is a plasma CVD method or an atmospheric pressure plasma CVD method.

According to a fifth aspect of the present invention, in the thin film forming method according to the fourth aspect, in the case of the atmospheric pressure plasma CVD method, an inert gas containing any one of helium, argon and nitrogen gas, and a reactive gas are included. A mixed gas containing a is supplied to both electrodes facing each other under atmospheric pressure or a pressure in the vicinity of atmospheric pressure, and is discharged at a high frequency voltage of 1 kHz or more to be in a plasma state, and the base material is in the plasma state. It is characterized by being exposed to a mixed gas.

The invention according to claim 6 is characterized in that the thin film according to claim 1 or 2 constitutes a part or the whole.

The present invention will be described in detail below. The present inventor generally uses PVD (physical vapor deposition) and CVD.
It has been found that a thin film formed by the method (chemical vapor deposition), particularly a film having fine irregularities in which nuclei are formed on the surface due to impurities or crystal lattice mismatch, can be used for optical properties. The thin film of the present invention formed on such a substrate and having fine irregularities on the outermost surface layer is useful as an antireflection film having an ideal low refractive index. The antireflection film may be a multilayer film in which a high-refractive index layer, a medium-refractive index layer, and a low-refractive index layer are laminated, or may be a single-layer film having only a low-refractive index layer. In the case of a multilayer film, the outermost surface layer is a low refractive index layer.

JIS B 06 having unevenness on the outermost surface layer
The average interval defined by 01 is 10 nm or more and 400 nm
And the arithmetic mean roughness is 10 nm or more and 10 or less.
It is 0 nm or less. Here, the average interval of the unevenness is 10 nm
More than 400 nm and less than 10 nm
The reason why the average spacing of the unevenness is 40 is set to 100 nm or less.
If it is larger than 0 nm and the arithmetic mean roughness is larger than 100 nm, the unevenness is too large and the unevenness becomes large near the wavelength of the light required for antireflection, so that the incident light is scattered and This is because the linear transmittance of is decreased. On the other hand, when the average spacing of the irregularities is smaller than 10 nm and the arithmetic mean roughness is smaller than 10 nm,
This is because the unevenness is too small and the refractive index is not sufficiently lowered. From the viewpoint that the effect of the present invention can be preferably obtained, in particular, the average spacing Sm of the irregularities is 20 nm or more and 100 nm or less, and the arithmetic average roughness Ra is 50 nm or more and 90 n or more.
It is preferably m or less.

The substrate that can be used in the present invention is not particularly limited as long as it can form a thin film on its surface, such as a film-shaped one and a three-dimensional one such as a lens-shaped one. Further, the material thereof is not limited at all, and metal, glass, resin, etc. can be used.

The material constituting the base material is not particularly limited, either.
The thin film of the present invention, which will be described later, is particularly preferably formed by atmospheric pressure plasma treatment, so that it is under atmospheric pressure or a pressure near atmospheric pressure, and since it is low temperature glow discharge, other than glass, resin Can be preferably used. Preferably, cellulose ester such as film-like cellulose triacetate, polyester, polycarbonate, polystyrene, further gelatin on these,
A material coated with polyvinyl alcohol (PVA), an acrylic resin, a polyester resin, a cellulosic resin, or the like can be used.

As the base material, an antiglare layer or a clear hard coat layer coated on a support, or a back coat layer or an antistatic layer coated on the support can be used. In this case, a preferred constitutional example of the substrate having the antireflection film is as shown below. i) Backcoat layer / support / antiglare layer / high refractive index layer / low refractive index layer ii) Backcoat layer / support / antiglare layer / medium refractive index layer / high refractive index layer / low refractive index layer iii ) Backcoat layer / support / antiglare layer / high refractive index layer /
Low refractive index layer / high refractive index layer / low refractive index layer iv) back coat layer / support / antistatic layer / antiglare layer / medium refractive index layer / high refractive index layer / low refractive index layer v) antistatic layer / Support layer / Anti-glare layer / Medium refractive index layer / High refractive index layer / Low refractive index layer

The above-mentioned support (also used as a base material)
Specifically, polyethylene terephthalate,
Polyester film such as polyethylene naphthalate,
Polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film, cellulose acetate phthalate film, cellulose triacetate, a film made of cellulose ester such as cellulose nitrate or a derivative thereof, Polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film, norbornene resin film, polymethylpentene film, polyetherketone film, polyimide film, polyethersulfone film, polysulfone film , Polyetherketone imimi Films, polyamide films,
Examples thereof include a fluororesin film, a nylon film, a polymethylmethacrylate film, an acrylic film and a polyarylate film.

These materials may be used alone or in an appropriate mixture. Above all, Zeonex (manufactured by Nippon Zeon Co., Ltd.), ARTON (Nippon Synthetic Rubber Co., Ltd.)
Commercially available products such as manufactured products) can be preferably used. Furthermore, even for materials with a large intrinsic birefringence such as polycarbonate, polyarylate, polysulfone, and polyethersulfone, conditions such as solution casting and melt extrusion, as well as stretching conditions in the longitudinal and transverse directions, etc. are set appropriately. Can be obtained. Further, the support according to the present invention is not limited to the above description. The film thickness is 10 μm
A film of ˜1000 μm is preferably used.

The thin film of the present invention is not a known method of scratching the surface into a mesh using a laser or the like, but a known coating method, PVD such as vacuum deposition or sputtering.
Method, a thermal CVD method, a photo CVD method, a CVD method such as a plasma CVD method or an atmospheric pressure plasma CVD method, or the like, and a flat surface can be easily formed. PVD method and C
In the VD method, in order to form the thin film of the present invention, a temperature between an appropriate temperature for producing an amorphous film and an appropriate temperature for producing a crystalline film, or a temperature for producing a crystalline film Also, it is preferable to manufacture at a high temperature. The temperature referred to here may be either the atmosphere or the substrate temperature. Further, as conditions applicable only to the sputtering method and the plasma CVD method, the amount of electric power supplied from the high frequency power source or the direct current power source is set to an appropriate value for the production conditions of the amorphous film and an appropriate value for producing the crystal film. It is preferable to manufacture it by using an electric power amount in between.

From the viewpoint of obtaining the effects described in the present invention, it is particularly preferable to form by the atmospheric pressure plasma CVD method. The atmospheric pressure plasma CVD method is also preferable in that it does not require an evacuation process for production, the discharge conditions can be changed, and the surface state of the film can be arbitrarily controlled. In the atmospheric pressure plasma CVD method, the reaction gas is brought into a plasma state by discharging between opposing electrodes under atmospheric pressure or a pressure near the atmospheric pressure, and the base material is exposed to the reaction gas in the plasma state. The thin film of the present invention is formed thereon. In the atmospheric pressure plasma CVD method, in order to obtain a high plasma density and increase the film formation rate, it is preferable to supply a certain amount of electric power with a high frequency voltage, and with a high frequency voltage exceeding 1 kHz between opposing electrodes,
It is preferable to excite a mixed gas containing an inert gas containing any one of helium, argon and nitrogen gas and a reactive gas to generate plasma. By applying such a high-power electric field, a dense thin film can be obtained with high production efficiency.

Next, the atmospheric pressure plasma CVD method will be described in detail. FIG. 1 is a conceptual diagram showing an example of a plasma discharge processing container 20 used in the plasma discharge processing device 10. In the present embodiment, the plasma discharge processing container 20 shown in FIG. 2 is used.

In FIG. 1, a long film-shaped substrate F is a roll electrode 21 which rotates in the conveying direction (clockwise in the figure).
It is transported while being wound around. The fixed electrode 22
Is composed of a plurality of cylinders and is installed so as to face the roll electrode 21. The base material F wound around the roll electrode 21 is
It is pressed by the nip rollers 23a and 23b, is regulated by the guide roller 24, is conveyed to the discharge treatment space secured by the plasma discharge treatment container 20, is subjected to discharge plasma treatment, and is then conveyed to the next step via the guide roller 25. . Further, the partition plate 26 is arranged close to the nip roller 23b, and suppresses the air entrained in the base material F from entering the plasma discharge processing container 20.

The entrained air is preferably kept to 1% by volume or less, more preferably 0.1% by volume or less with respect to the total volume of the gas in the plasma discharge treatment container 20. This can be achieved by the nip roller 23b.

The mixed gas used in the discharge plasma treatment (an inert gas and an organic gas containing a reactive gas such as an organic fluorine compound, a titanium compound or a silicon compound) is treated by the plasma discharge treatment from the air supply port 27. The gas introduced into the container 20 and processed is exhausted from the exhaust port 28.

FIG. 2 is a schematic diagram showing another example of the plasma discharge processing container 20 as described above, whereas the plasma discharge processing container 20 of FIG. 1 uses the cylindrical fixed electrode 22. The prismatic fixed electrode 29 is used in the plasma discharge processing container 20 shown in FIG.

Compared with the cylindrical electrode 22 shown in FIG.
The prismatic electrode 29 shown in FIG. 2 is preferably used in the thin film forming method of the present invention.

3 (a) and 3 (b) are schematic views showing an example of the cylindrical roll electrode 21 described above, and FIGS. 4 (a) and 4 (b).
5 is a schematic view showing an example of a cylindrical fixed electrode 22, FIG.
(A), (b) is the schematic which shows an example of the prismatic fixed electrode 29.

In FIG. 3 (a), a roll electrode 21 which is an earth electrode is a ceramic-coated dielectric material 21b obtained by thermal-spraying ceramics onto a conductive base material 21a such as a metal and then sealing it with an inorganic material. It is composed of a covered combination. Ceramic coated dielectric 2
1b is coated with 1mm for 1mm and roll diameter is 200φ.
It is manufactured so that it is grounded to earth.

Further, as shown in FIG. 3B, the roll electrode 21 may be constituted by a combination in which a conductive base material 21A such as metal is covered with a lining-treated dielectric 21B provided with an inorganic material by lining. . As the lining material, silicate glass, borate glass, phosphate glass, germanate glass, tellurite glass,
Aluminate glass, vanadate glass and the like are preferably used, but among these, borate glass is more preferably used because it is easy to process. Examples of the conductive base materials 21a and 21A such as metals include metals such as titanium, silver, platinum, stainless steel, aluminum and iron, and stainless steel or titanium is preferable from the viewpoint of processing. Also, as the ceramic material used for thermal spraying, alumina.
Silicon nitride or the like is preferably used, and among these, alumina is more preferably used because alumina is easy to process. In this embodiment, the base materials 21a, 21 of the roll electrode are
A uses a stainless steel jacket roll base material having a cooling means by cooling water (not shown).

FIGS. 4 (a) and 4 (b) and FIG. 5 (a),
(B) is a fixed electrode 22 and an electrode 29, which are application electrodes, and is configured in the same combination as the roll electrode 21 described above.

As a power source for applying a voltage to the applying electrode,
High frequency power supply (200k
Hz), a high frequency power source manufactured by Pearl Industry (800 kHz), a high frequency power source manufactured by JEOL Ltd. (13.56 MHz), a high frequency power source manufactured by Pearl Industry (150 MHz), a high frequency power source manufactured by Pearl Industry, and the like can be used.

FIG. 6 is a conceptual diagram showing an example of the plasma discharge processing apparatus 10 used in the present invention. 6, the plasma discharge processing container 20 is the same as that shown in FIG. 2, but a gas generator 40, a power supply 50, an electrode cooling unit 70, and the like are further arranged as a device configuration.
As a cooling agent for the electrode cooling unit 70, an insulating material such as distilled water or oil is used.

The electrodes 21 and 29 shown in FIG. 6 are the same as those shown in FIGS. 3 and 5, and the gap between the opposing electrodes is set to, for example, about 1 mm. The distance between the electrodes is determined in consideration of the thickness of the solid dielectric material provided on the base material of the electrodes, the magnitude of the applied voltage, the purpose of utilizing plasma, and the like. The shortest distance between the solid dielectric and the electrode when the solid dielectric is installed on one of the electrodes, and the shortest distance between the solid dielectrics when the solid dielectric is installed on both of the electrodes are uniform in both cases. 0.5m from the point of view of stable discharge
m to 20 mm, particularly preferably 1 mm ± 0.
It is 5 mm.

The roll electrode 21 and the fixed electrode 29 are arranged at predetermined positions in the plasma discharge treatment container 20, the flow rate of the mixed gas generated by the gas generator 40 is controlled, and the gas supply means 41 is used to supply the gas. It is put into the plasma discharge processing container 20 from 27, and the inside of the plasma discharge processing container 20 is filled with the mixed gas used for the plasma processing and exhausted from the exhaust port 28. Next, a voltage is applied to the electrodes 21 and 29 by the power source 50, the roll electrode 21 is grounded to ground, and discharge plasma is generated. Here, the base material F is supplied from the roll-shaped original winding base material 60, and the electrodes in the plasma discharge processing container 20 are in one-side contact (contact with the roll electrode 21) via the guide roller 24. Be transported. Then, the surface of the base material F is formed by discharge plasma during transportation, and after a thin film containing an inorganic substance derived from the reactive gas in the mixed gas is formed on the surface, it is passed through the guide roller 25 to the next step. Be transported. Here, the base material F is film-formed only on the surface which is not in contact with the roll electrode 21.

The value of the voltage applied from the power source 50 to the fixed electrode 29 is appropriately determined. For example, the voltage is 0.5 to 1
At 0kV, the power supply frequency exceeds 1kHz and 150M
It is adjusted to below Hz. Here, as a method of applying a power source, either a continuous sine wave continuous oscillation mode called a continuous mode or an intermittent oscillation mode called ON / OFF which is intermittently called a pulse mode may be adopted.

The plasma discharge processing container 20 is preferably made of an insulating material such as a processing container made of Pyrex (R) glass, but may be made of metal as long as it can be insulated from the electrodes. For example, a polyimide resin or the like may be attached to the inner surface of an aluminum or stainless steel frame, and the metal frame may be sprayed with ceramics to have an insulating property.

Further, in order to suppress the influence on the substrate during the discharge plasma treatment to a minimum, the temperature of the substrate during the discharge plasma treatment is adjusted to a temperature between room temperature (15 ° C. to 25 ° C.) and less than 200 ° C. It is preferable that the temperature is from room temperature to 11
It is to adjust to 0 ° C. In order to adjust to the above temperature range, the electrode and the base material are subjected to discharge plasma treatment while being cooled by a cooling means, if necessary.

In the present embodiment, the above plasma treatment is performed at or near atmospheric pressure, but the plasma treatment may be performed under vacuum or high pressure as described above. In addition, near atmospheric pressure is 20 kPa-110 kPa.
In order to obtain the effect described in the present invention, 93 kPa to 104 kPa is preferable.

In the discharge electrode used for the atmospheric pressure plasma treatment, at least the base film F of the electrode is used.
It is preferable that the surface on the side in contact with is adjusted so that the maximum height (Rmax) of the surface roughness defined by JIS B 0601 is 10 μm or less, and the maximum value of the surface roughness is 8 μm or less. Preferably.

The plasma discharge processing apparatus 10 shown in FIGS. 1 and 2 described above is an apparatus used when the base material F is a film. For example, a base material having a thickness larger than that of the film, For example, in the case of a lens or the like, the plasma discharge processing apparatus 100 as shown in FIG. 7 is used. Figure 7
FIG. 6 is a schematic view showing another example of the plasma discharge processing apparatus. This plasma discharge processing apparatus 100 includes a high frequency power supply 1
For the electrode connected to 01, the flat plate type electrode 103
A substrate (for example, lens L) is placed on the electrode 103 by using. On the other hand, as an electrode connected to the low-frequency power source 102, a rectangular rod-shaped electrode 104b is provided on the electrode 103 so as to face it. The rectangular rod-shaped electrode 104a is grounded. In this case, the mixed gas is supplied to the electrode 104a,
It is supplied from above 104b, and is brought into a plasma state in a range between the electrodes 104a and 104b and the electrode 103.

The gas used in the present invention varies depending on the kind of thin film to be provided on the substrate, but is basically a mixed gas of an inert gas and a reactive gas for forming the thin film. The reactive gas is 0.01 to 1 with respect to the mixed gas.
It is preferable to contain 0% by volume. As the film thickness of the thin film, a thin film in the range of 0.1 nm to 1000 nm can be obtained.

As the above-mentioned inert gas, the 18th of the periodic table is used.
Group elements, specifically, helium, neon, argon, krypton, xenon, radon, and nitrogen gas, but in order to obtain the effect described in the present invention, helium,
Argon and nitrogen gas are preferably used.

For example, as a reactive gas, zinc acetylacetonate, triethylindium, trimethylindium, diethylzinc, dimethylzinc, etraethyltin, etramethyltin, di-n-butyltin diacetate, tetrabutyltin, tetraoctyltin, indium acetyl. To form a metal oxide layer useful as a medium refractive index layer of a conductive film, an antistatic film, or an antireflection film by using a reactive gas containing at least one organometallic compound selected from acetonate and the like. You can

Further, by using the fluorine-containing compound gas, it is possible to form a fluorine-containing group on the surface of the substrate to reduce the surface energy and obtain a water-repellent film having a water-repellent surface. Examples of the elemental fluorine-containing compound include fluorinated carbon compounds such as propylene hexafluoride (CF3CFCF2) and octafluorocyclobutane (C4F8). From the viewpoint of safety, propylene hexafluoride and cyclobutane octafluoride that do not generate hydrogen fluoride, which is a harmful gas, are used.

A hydrophilic polymer film can be deposited by performing the treatment in an atmosphere of a monomer having a hydrophilic group and a polymerizable unsaturated bond in the molecule. Examples of the hydrophilic group include a hydroxyl group, a sulfonic acid group, a sulfonate group, a primary or secondary or tertiary amino group, an amide group, 4
Examples thereof include hydrophilic groups such as a primary ammonium group, a carboxylic acid group, and a carboxylic acid group. Also, a hydrophilic polymer film can be similarly deposited by using a monomer having a polyethylene glycol chain.

As the above-mentioned monomer, acrylic acid, methacrylic acid, acrylamide, methacrylamide, N, N
-Dimethylacrylamide, sodium acrylate, sodium methacrylate, potassium acrylate, potassium methacrylate, sodium styrenesulfonate, allyl alcohol, allylamine, polyethylene glycol dimethacrylic acid ester, polyethylene glycol diacrylic acid ester, and the like. At least 1
Seeds can be used.

By using a reactive gas containing an organic fluorine compound, a silicon compound or a titanium compound, the low refractive index layer or the high refractive index layer of the antireflection film can be provided.

As the organic fluorine compound, fluorocarbon gas, fluorohydrocarbon gas and the like are preferably used. Examples of the carbon fluoride gas include carbon tetrafluoride and carbon hexafluoride, specifically, tetrafluoromethane, tetrafluoroethylene, hexafluoropropylene, octafluorocyclobutane, and the like.
As the above-mentioned fluorohydrocarbon gas, difluoromethane,
Examples include tetrafluoroethane, propylene tetrafluoride, propylene trifluoride, and the like.

Furthermore, halides of fluorohydrocarbon compounds such as trifluoromethane trichloride, monochlorodifluoromethane, dichlorotetrafluorocyclobutane and the like and fluorine substitution products of organic compounds such as alcohols, acids and ketones are used. It can be used, but is not limited thereto. Further, these compounds may have an ethylenically unsaturated group in the molecule. The above compounds may be used alone or in combination.

When the above-mentioned organic fluorine compound is used in the mixed gas, the content of the organic fluorine compound in the mixed gas is preferably 0.1 to 10% by volume, more preferably 0.1. ~ 5% by volume.

Further, when the organic fluorine compound is a gas at room temperature and pressure, it can be used most easily because it can be used as it is as a constituent component of a mixed gas. However, when the organic fluorine compound is a liquid or a solid at room temperature and atmospheric pressure, it may be used after being vaporized by a method such as heating or depressurization, or may be dissolved in a suitable solvent before use. .

When the titanium compound described above is used in the mixed gas, the content of the titanium compound in the mixed gas is 0.
It is preferably 1 to 10% by volume, and more preferably 0.1 to 5% by volume.

The hardness of the thin film can be remarkably improved by adding 0.1 to 10% by volume of hydrogen gas in the mixed gas described above. Further, by containing 0.01 to 5 volume% of a component selected from oxygen, ozone, hydrogen peroxide, carbon dioxide, carbon monoxide, hydrogen, and nitrogen in the mixed gas, the reaction is promoted and the density is high. A high quality thin film can be formed.

As the above-mentioned silicon compound and titanium compound, a metal hydrogen compound and a metal alkoxide are preferable from the viewpoint of handling, and they are not corrosive or generate a harmful gas.
A metal alkoxide is preferably used because it is less likely to be contaminated during the process. In addition, the silicon compound described above,
To introduce a titanium compound between the electrodes, which is the discharge space,
Both may be in a gas, liquid or solid state at room temperature and atmospheric pressure. In the case of gas, it can be introduced into the discharge space as it is, but in the case of liquid or solid, it is used after being vaporized by means such as heating, decompression, ultrasonic irradiation or the like. When a silicon compound or a titanium compound is used after being vaporized by heating, a metal alkoxide that is liquid at room temperature and has a boiling point of 200 ° C. or lower, such as tetraethoxysilane and tetraisopropoxytitanium, is preferably used for forming the antireflection film. The metal alkoxide may be used after diluting it with a solvent, and as the solvent, an organic solvent such as methanol, ethanol, n-hexane, or a mixed solvent thereof can be used.
Since these diluting solvents are decomposed into molecules and atoms during the plasma discharge treatment, the influence on the formation of a thin film on the substrate, the composition of the thin film, etc. can be almost ignored.

Examples of the silicon compound described above include:
Organometallic compounds such as dimethylsilane and tetramethylsilane, metal hydrogen compounds such as monosilane and disilane, metal halogen compounds such as silane dichloride and silane trichloride,
It is preferable to use alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and dimethyldiethoxysilane, and organosilanes, but not limited to these. Moreover, these can be used in appropriate combination.

When the silicon compound described above is used in the mixed gas, the content of the silicon compound in the mixed gas is 0.1 to 0.1%.
It is preferably 10% by volume, more preferably
It is 0.1 to 5% by volume.

Examples of the titanium compound described above include organometallic compounds such as tetradimethylaminotitanium, metal hydrogen compounds such as monotitanium and dititanium, metal halogen compounds such as titanium dichloride, titanium trichloride and titanium tetrachloride,
Tetraethoxy titanium, tetraisopropoxy titanium,
It is preferable to use a metal alkoxide such as tetrabutoxytitanium, but not limited thereto.

When an organometallic compound is added to the reactive gas, for example, Li, Be, B, N can be used as the organometallic compound.
a, Mg, Al, Si, K, Ca, Sc, Ti, V, C
r, Mn, Fe, Co, Ni, Cu, Zn, Ga, G
e, Rb, Sr, Y, Zr, Nb, Mo, Cd, In,
Ir, Sn, Sb, Cs, Ba, La, Hf, Ta,
W, Tl, Pb, Bi, Ce, Pr, Nd, Pm, E
u, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu
Can include a metal selected from More preferably, these organometallic compounds are selected from metal alkoxides, alkylated metals, and metal complexes.

As described above, a thin film (antireflection film) having fine irregularities is formed on the outermost surface layer of the present invention by subjecting the surface of the substrate to the atmospheric pressure plasma treatment by the plasma discharge treatment apparatus.

Further, it is preferable to form an antifouling layer on the surface of the thin film after forming the thin film having fine irregularities on the outermost surface layer. The antifouling layer is formed, for example, by adding isopropyl alcohol to a heat-crosslinkable fluorine-containing polymer to prepare a 0.2% by mass crude dispersion liquid and applying it to the surface of the outermost surface layer with a bar coater.

In addition to the above-mentioned coating method,
For example, the plasma discharge treatment apparatus 10 shown in FIG. 6 may be used to form a film by atmospheric pressure plasma treatment under the following treatment conditions. (Power supply frequency and manufacturer) 13.56MHz (Made by Pearl Industry) (Discharge output density) 4W / cm ² (Gas condition) Gas 1: Argon ... 99.5% by volume Gas 2: Di-n-butyltin diacetate (Dibutyltin) Bubbling of argon to (diacetate) by heating vaporization of indium acetylacetonate (solid) A mixture of vapor of di-n-butyltin diacetate and indium acetylacetonate contained by bubbling or heating vaporization. 0.5% by volume

[0062]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples. In addition, Comparative Example 1 and Inventive Examples 1 to 3 described below.
Is a film formed by the atmospheric pressure plasma treatment described above,
In Comparative Example 2 and Inventive Examples 4 and 5, film formation was performed by known coating.

Using the plasma as the base material and using the plasma discharge treatment apparatus 100 shown in FIG. 7 on the glass, a film containing SiO ₂ as a main component was formed under the following plasma treatment conditions. Examples 1-3 were obtained.

[0064] The plasma processing conditions (plasma power source frequency and manufacturers) 13.56MHz (Pearl Kogyo Co., Ltd.) (discharge output ^{conditions) 2.2W / cm 2, 3.3W /} cm 2, 4W / cm 2,
6.6 W / cm ² Here, the unit W / cm ² is the applied output (unit W) divided by the discharge area (cm ² ). (Gas condition) Gas 1: Argon ... 99.5% Gas 2: Oxygen ... 0.5 vol% with respect to the whole mixed gas Gas 3: Tetraethoxysilane vapor ... 0.25 vol% with respect to the whole mixed gas 1 to 3 were mixed uniformly just before the discharge space to form a reaction gas. Gas 3 can supply tetraethoxysilane vapor by bubbling tetraethoxysilane (liquid) heated to 60 ° C. using a part of gas 1.

On the other hand, the base material is a 80 μm triacetyl cell.
As a loin film (Konikatak KC8UX),
Triacetyl cellulose film has the following anti-glare properties
Barco coating liquid for hard coat layer and coating liquid for low refractive index layer
To obtain Comparative Example 2 and Inventive Examples 4 and 5
It was (Preparation of coating liquid for antiglare hard coat layer) Dipentaery
Thritol pentaacrylate and dipentaerythritol
250 g of a mixture of ruhexaacrylate and methyl ethyl
Ketone / cyclohexanone = 50/50% mixed solvent 4
It was dissolved in 39 g, and the resulting solution was added with a photopolymerization initiator 7.5.
g and 5.0 g of photosensitizer, 49 g of methyl ethyl keto
Solution and added the solution. This solution has an average particle size of 3 μm
Add 10 g of irregular shaped silica particles and use at high speed dispa
After stirring and dispersing at 5000 rpm for 1 hour, pore size is 30μ
m polypropylene filter to filter glare
A coating solution for a coat layer was prepared. (Preparation of coating liquid for low refractive index layer) Fluorine containing 1.41
50 g of photocurable sol-gel compound containing elementary polymer and silica
2.8 g of particulate methyl isobutyl ketone dispersion and methyl
After adding 147 g of luisobutyl ketone and stirring,
Low refractive index layer by filtering with a mixed ester filter
To prepare a coating solution. Where cellulose mixed ester
The pore size of the filter made is 0.5 μm, 0.025 μm,
Those having a thickness of 1 μm were used. (Coating liquid for anti-glare hard coat layer and coating for low refractive index layer
Application of cloth liquid) and 80 μm triacetyl cellulose
For the prepared anti-glare hard coat layer on the surface of the film
Apply the coating solution using a bar coater and dry at 120 ° C.
After that, using a 160W / cm air-cooled metal halide lamp
Illuminance 400 mW / cm², Irradiation dose 300 mJ / cm²
The coating layer is cured by irradiating the
A coating layer was formed. On the antiglare hard coat layer,
Apply the prepared low-refractive-index layer coating solution using a bar coater
And dried at 60 ° C, then illuminance 400 mW / cm ², Irradiation
Amount 300mJ / cm²The coating layer is cured by irradiating ultraviolet rays of
Then, heat at 120 ° C for 8 minutes to remove the thin film.
A base material was obtained.

Next, a substrate having a thin film formed thereon (Comparative Example 1,
2, the present invention examples 1 to 5), the average spacing Sm of the unevenness,
The arithmetic average roughness Ra, the refractive index, the adhesiveness, and the scratch resistance were evaluated, and the results are shown in Table 1. (Calculation of average interval Sm of irregularities and average roughness Ra) AFM
10c for the surface observed at (standard length 10 μm)
observing 100 points of mx 10 cm at 1 cm pitch, JIS
Calculated according to B 0601. (Refractive index) Otsuka Electronics Co., Ltd. reflectance spectrometer Fe300
0 from 400 to 400 with a 5 degree tilt from the regular reflection state.
The reflectance was measured for a wavelength (λ) in the 700 nm range. The film thickness was calculated optically from the value of λ / 4, and the refractive index was calculated based on this. Here, the value at a wavelength of 550 nm was adopted as the refractive index. (Adhesiveness) A test was performed by the base tape method according to JIS K5400. Specifically, 1m on the coated surface
Make 11 cuts vertically and horizontally at m intervals to form 100 1mm square bases. Stick cellophane tape on the bases and quickly peel off at 90 °. evaluated. Evaluation criteria: A 100 B 90 to 99 C 80 to 89 D 50 to 79 E 49 or less (scratch resistance) A test was performed according to JIS K 5400. Specifically, using # 0000 steel wool with a weight of 100 g per 1 cm ² , use 1
The scratches generated by rubbing 0 times were visually counted and evaluated. Evaluation criteria: A less than 5 B less than 5 to 10 C less than 10 to 20 D 20 or more

[0067]

[Table 1] Although glass was used as the substrate in Comparative Example 1 and Inventive Examples 1 to 3, the same as in Table 1 was obtained when using a 80 μm triacetyl cellulose film (Konicat KC8UX) or a polyethylene terephthalate film as the substrate. I was able to obtain the result. In this case, for example, it is preferable to form the thin film using the plasma discharge treatment apparatus 10 shown in FIG. Further, although the triacetyl cellulose film was used as the base material in Comparative Example 2 and Inventive Examples 4 and 5, the same results as in Table 1 could be obtained when the polyethylene terephthalate film was used as the base material.

The thin film having fine irregularities on the outermost surface layer of the present invention has an average spacing Sm of irregularities of 10 nm or more to 40 nm.
0 nm or less and the arithmetic mean roughness Ra is 10 nm
It was confirmed that when the thickness is 100 nm or less, an ideal low refractive index can be obtained, and the abrasion resistance and the adhesiveness are excellent.

[0069]

According to the present invention, the outermost surface layer has fine irregularities, the irregularities defined by JIS B 0601 have an average interval of 10 nm or more and 400 nm or less, and an arithmetic mean roughness of 10 nm or more. When the thickness is 100 nm or less, both low refractive index and scratch resistance can be achieved. Further, the fine irregularities formed on the outermost surface layer improve the adhesiveness, and the adhesiveness with the antifouling layer that is further formed on the surface of the outermost surface layer increases. Further, by providing the antifouling layer, it becomes easy to wipe off stains and fingerprints.
The thin film of the present invention is not a method of scratching the surface into a mesh shape using a known method such as laser, but coating, PV
D method, CVD method (plasma CVD method, atmospheric pressure plasma C
Since it is formed by the VD method or the like), it can be easily formed without going through complicated steps such as patterning.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a plasma discharge treatment container used for forming a thin film of the present invention.

FIG. 2 is a schematic view showing another example of the plasma discharge processing container.

FIG. 3 is perspective views (a) and (b) showing an example of a cylindrical roll electrode.

FIG. 4 is perspective views (a) and (b) showing an example of a fixed cylindrical electrode.

FIG. 5 is perspective views (a) and (b) showing an example of a fixed prismatic electrode.

FIG. 6 is a schematic view showing an example of a plasma discharge processing apparatus.

FIG. 7 is a schematic view showing another example of the plasma discharge processing apparatus.

[Explanation of symbols]

F film (base material) L lens (base material) 10, 100 Plasma discharge treatment device 21 and 22 electrodes (roll electrodes) 29 electrodes (fixed electrode) 103, 104a, 104b electrodes 50 power 101 power supply (high frequency power supply) 102 power supply (low frequency power supply)

Claims (6)

[Claims] 1. A thin film formed on a base material, wherein the outermost surface layer has fine irregularities, and the average interval of the irregularities defined by JIS B 0601 is 1.
A thin film having a thickness of 0 nm to 400 nm and an arithmetic average roughness of 10 nm to 100 nm. 2. The thin film according to claim 1, wherein an antifouling layer is formed on the surface of the outermost surface layer. 3. A thin film forming method for forming the thin film according to claim 1 or 2 on a base material, which is a coating method or PVD method in which a coating solution is applied on the base material and dried. A thin film forming method, characterized in that the thin film is formed by any one of a CVD method and a CVD method. 4. The thin film forming method according to claim 3, wherein the CVD method is a plasma CVD method or an atmospheric pressure plasma CVD method. 5. The thin film forming method according to claim 4, wherein when the atmospheric pressure plasma CVD method is used, a mixed gas containing an inert gas containing any one of helium, argon and nitrogen gas and a reactive gas. Is supplied to both opposing electrodes under atmospheric pressure or pressure near atmospheric pressure for 1 k.
Discharge with a high frequency voltage of Hz or more to make a plasma state,
A method for forming a thin film, which comprises exposing the base material to the mixed gas in the plasma state. 6. An antireflection film, wherein the thin film according to claim 1 or 2 constitutes a part or the whole.