JPH09258004A - Antireflection multilayered film and its film formation, as well as its film forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antireflection film having a water repellent layer which does not easily peel and has excellent durability and water repellent property, and a method for forming the antireflection film, as well as a device capable of easily and inexpensively producing the antireflection film. SOLUTION: The multilayered antireflection film 2 formed by forming >=2 layers of optical thin films 3 for antireflection consisting of >=2 kinds of materials varying in refractive index on a substrate 1, and forming the water repellent layer of a high-polymer material composed of C, F, H, N, S, O, Si, etc., on the optical thin films, is provided with an intermediate layer composed of any of Al, Ti, Si, Nb, Cr, Cu, Mg, Ta, or Zr at <=10Å between the optical thin films and the water repellent layer. Plural evaporating sources or sputtering devices for forming the optical thin films, an evaporating source or sputtering device consisting of high polymer materials for an the water repellent layer and the evaporating source or sputtering device for an intermediate layer consisting of a material which reactivity bonds with the materials of the thin film of the uppermost layer of the optical thin films and the water repellent layer are prepd in one vacuum vessel to form the films.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antireflection multilayer film applied to optical equipment such as spectacle lenses and various parts, a film forming method thereof, and a film forming apparatus thereof.

[0002]

2. Description of the Related Art Conventionally, dielectric materials having a low refractive index and a high refractive index are alternately formed on both surfaces or one surface of a spectacle lens so as to prevent a decrease in visibility due to reflection inside the lens and to prevent light from being outside the lens. To prevent the reflection of. Further, recently, in order to prevent reflection of external light in VDT work, a display having a direct antireflection film formed on the surface thereof, PET (polyethylene terephthalate), or PMM.
An antireflection film is formed on a film-like polymer substrate such as A (polymethylmethacrylate), and the film is attached to the display or placed on the front surface, which is commercially available.

Due to their functional properties, these antireflection films are always used in the external living environment, such as rainwater in eyeglass lenses.
Sweat, saliva, and display are exposed to splashes of coffee, tea, liquor, etc., infants' fingerprints and drools, etc., and the antireflection performance as an optical film deteriorates. In the case of ordinary contamination, it is generally relatively rough to wash with a cloth or rag containing water or detergent.

However, since the dielectric film that constitutes the optical film has a large surface energy, once the so-called mineral components such as oil contained in body fluids and Ca, Mg, Na contained in beverages, etc., once adhered, they can be washed with detergent or the like. Even if it is wiped, a residual of 100 Å or more remains. In addition, uneven wiping may occur, the optical characteristics may be significantly deteriorated, and the antireflection performance may be lost. Therefore, the antireflection film is required to have water repellency, that is, water repellency.

Therefore, in the conventional antireflection film, C, F, H, N, S, O and Si are formed on the dielectric layer forming the optical film.
20 to 3 is a polymer material composed of, for example, a so-called surfactant.
It is formed with a thickness of 0 °.

The antireflection film is usually composed of a multilayer film, and the uppermost dielectric film, SiO _x , AlO _x , MgF _x.
The contact angle with water is usually about 10 ° for SiO _x , AlO _x ,
The water repellency of MgF _x is about 60 ° and the water repellency is insufficient. However, the one formed with the above-mentioned surfactant shows a water contact angle of 110 °, and the water repellency in practice is sufficiently satisfied. . FIG. 1A shows the structure of a conventional antireflection film having a TiO _X and SiO _X film, and FIG. 1B shows the structure of a conventional antireflection film having an ITO and SiO _X film.

Since the antireflection film is an optical filter which transmits visible light, transparent PET, PMMA, glass or the like having a light transmitting property is usually used for the substrate. The schematic diagram (a) of FIG. 1 shows a structure in which four layers of a high-refractive-index dielectric film TiO _x and a low-refractive-index SiO _x film are alternately laminated with a film thickness corresponding to a design value. In FIG. 2B, the first and third layers on the substrate are made of conductive ITO films, and the antireflection film has an electromagnetic shield function by having conductivity. . In any case, the uppermost layer is SiO _x , which has a low refractive index, in order to develop the antireflection property.
AlO _x , MgF _x , or mixtures thereof such as A
material such as l-Si-O _X is selected. A water-repellent layer of a surfactant having a film thickness of 30 Å or less is formed on the uppermost film of these conventional antireflection films so as not to impair the antireflection property.

FIG. 2 is an explanatory view of an example of a conventional film forming apparatus for an antireflection film, which is a vacuum tank a for forming an optical film forming the antireflection film and a vacuum for forming a water repellent layer. A tank b is provided separately from the tank b. First, a roll-shaped polymer film substrate c, such as PET, attached to a feeding roll d in a vacuum tank a is circulated through a film-forming drum e to a winding roll f. The sputtering target of the device g is sputtered by alternately supplying power from an RF power source to the four sputtering devices g arranged around the drum e, and the thin films of TiO ₂ and SiO ₂ are alternately circulated and moved. A film is formed on the substrate c and wound up. The film thickness is adjusted by the input amount of RF power. Then, the wound substrate c is attached to a pay-out roll h in a vacuum chamber b kept in a vacuum of about 10 ⁻⁵ Torr, from which a film-forming drum i is circulated so that the take-up roll j is wound up with DC. An antireflection multilayer film is formed by forming a water repellent layer by vapor-depositing a surfactant such as behenic acid having a film thickness of about 30Å, which is melted and evaporated from an evaporation source k of a tungsten boat connected to a power source, to form a water repellent layer. The thickness of the water repellent layer can be adjusted to a desired value by adjusting the power of the DC power supply. l and m are vacuum exhaust holes connected to a vacuum pump, n is an argon gas inlet,
The inside of the vacuum chamber a is adjusted to about 10 ⁻² to 10 ⁻⁴ Torr by the gas introduction amount and the exhaust amount. Incidentally, it is also practiced to use a vapor deposition method for forming an optical film and form a water repellent layer by CVD, screen printing, dipping or the like.

[0009]

In the conventional antireflection film typically shown in FIG. 1, a surfactant which is a water repellent layer is directly formed on a laminated dielectric film which is an optical film. There is. Usually, the film thickness of the water-repellent layer that does not impair the optical properties of the optical film, that is, the antireflection property is 30 Å or less, so that the film thickness is limited to about a monolayer of the surfactant. Therefore, as the surfactant, a material that weakly electrically bonds to the dielectric material that is the optical film by electrical polarization of a carboxyl group or the like is selected. However, since it is a bond that does not involve a chemical reaction, there is a drawback that film peeling occurs due to mechanical friction.

The antireflection film prepared by the apparatus of FIG. 2 was obtained by impregnating absorbent cotton with 100% ethanol and ramming 10 times at a load of 250 g / cm ² and a speed of 2 cm / sec. 110 ° is reduced to 80 °, which is not satisfactory for practical use. Moreover, since the apparatus for film formation of the optical film and the film formation of the water-repellent layer are separated separately, the cost is high from the viewpoint of productivity, and the substrate is used after forming the optical film in the vacuum chamber. From this, the film is once taken out into the atmosphere and stored in a vacuum tank for film formation of the water repellent layer, so that H ₂ O, O ₂ , N _{2 and the} like in the atmosphere adhere to it, and the durability of the water repellent layer is improved. Does not improve. Specifically, in the vacuum chamber a of the apparatus shown in FIG.
The optical film prepared according to the specifications of 1. is left in an atmosphere of 50 ° C. and a humidity of 55%, and the standing time is changed, and the film is placed in a vacuum chamber b.
After the water-repellent layer was formed according to the above specifications, the result of measuring the water contact angle at 0.5 cc is as shown in FIG. The water contact angle shown by a black circle is a measured value after 100% ethanol is contained in absorbent cotton, and it is run 10 times at a load of 250 g / cm ² and a speed of 2 cm / sec. Water contact angle. The water contact angle after labyrinth decreases as the time left in the atmosphere becomes longer.

[0011]

[Table 1]

[0012]

[Table 2]

The present invention provides an antireflection film provided with a water-repellent layer having excellent durability and water-repellent property, which does not easily peel off,
It is also an object of the present invention to provide a method for forming this antireflection film and an apparatus capable of inexpensively producing this antireflection film.

[0014]

According to the present invention, on a substrate,
An antireflection optical thin film having two or more layers is formed of two or more materials having different refractive indexes, and C, F, H, and
In an antireflection multilayer film formed by forming a thin film of a polymer material composed of N, S, O, Si, etc. as a water repellent layer, an Al film having a film thickness of 10 Å or less is provided between the optical thin film and the water repellent layer. , Ti, S
By providing an intermediate layer composed of any one of i, Nb, Cr, Cu, Mg, Ta, and Zr, the above object is achieved. The intermediate layer is made of a material which is bonded to the uppermost thin film of the optical thin film and the water repellent layer by a chemical reaction, and the intermediate layer is formed on the optical thin film by vapor deposition or sputtering, and the water repellent layer is formed thereon. Is preferably formed by vapor deposition or sputtering. The method according to claims 4 and 5 makes it possible to inexpensively produce an antireflection multilayer film which does not easily peel off and has good water repellency. It can be implemented accurately depending on the device configuration.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the schematic view of an antireflection multilayer film shown in FIG. 4, in which reference numeral 1 indicates colored or colorless transparent materials such as glass and plastics. A substrate 2 having an arbitrary thickness formed of a ceramics substrate or a polymer film substrate, 2 denotes an antireflection multilayer film provided on the substrate 1, and the film 2 has a different refractive index formed on the substrate 1. Further, it has an antireflection optical thin film 3 made of two or more kinds of materials and formed in two or more layers, and a water repellent layer 4 made of behenic acid for protecting the optical thin film 3. The water-repellent layer 4 is
Usually, it is about 30Å or less.

Although such a film structure is also provided conventionally, in the present invention, Al, Ti, Si, Nb, Cr, C having a film thickness of 10 Å or less between the optical thin film 3 and the water repellent layer 4.
The intermediate layer 5 made of any one of u, Mg, Ta, and Zr and chemically reacting with the material of the uppermost thin film of the optical thin film and the water repellent layer 4 is provided, and the conventional water repellent layer is easily peeled off and water repellent. I tried to eliminate the drawback that is easily lost. Glass, PET, and PMMA are often used for the substrate 1. As the optical thin film 3, TiO _x , SiO _x , AlO _x , MgF _x , TaO _x ,
Known materials such as MgO, ZrO _x and ITO are used,
Two or more layers, for example, four layers 3a, 3b, 3c and 3d are formed by sputtering or vapor deposition to have a film thickness according to the film design value. The intermediate layer 5 is also formed to be extremely thin by sputtering or vapor deposition so as not to impair the antireflection function, firmly adheres to the optical thin film 3 by a chemical reaction, and also chemically reacts with the water repellent layer 4 to be bonded thereto. 4 does not easily peel from the optical thin film 3.

An example of a manufacturing apparatus for forming the antireflection multilayer film 2 on the polymer film substrate 1 is as shown in FIG. 5, and two film forming drums 7 and 8 are rotated in one vacuum chamber 6. The space around the film forming drums 7 and 8 is divided into three parts by partition walls 9, 10 and 11, and a part of the peripheral surface of both film forming drums 7 and 8 is divided into the space 12 of one of them. At the same time as exposing the substrate 1, a pay-out roll 13 and a take-up roll 14 for the substrate 1 are arranged, and two or more sputtering devices 16 for forming the antireflection optical thin film 3 in two or more layers in the remaining space 15.
a, 16b, 16c, 16d are provided, and the evaporation source 18 for forming the water-repellent layer 4 is provided in the other space 17 remaining, and the film formation of the optical thin film 3 is completed in the space 12 of the one. Sputtering device 19 for forming the intermediate layer 5 on the substrate 1.
Is provided. Each of the spaces 15, 17 for forming the optical thin film 3 and the water-repellent layer 4 is provided with an exhaust port 20, 21 connected to a vacuum pump, respectively, and each space 15, 17 is provided with a vacuum pressure suitable for sputtering or vapor deposition. Exhaust to. Reference numeral 22 is a gas inlet for introducing a sputtering gas such as argon.

The roll-shaped polymer film substrate 1 is set on the feeding roll 13, and the spaces 12, 15, and 17 are exhausted from the exhaust ports 20 and 21 so as to have a vacuum pressure suitable for film formation. Then, the feeding roll 13 and the winding roll 14 are driven to drive the respective sputtering devices 16a to 16d, 1
When RF power is applied to 9 and DC power is applied to the evaporation source 18, four layers of the optical thin film 3 are formed on the surface of the moving substrate 1, then the intermediate layer 5 is formed, and further, for example, 2 layers are formed thereon.
The 0 Å water repellent layer 4 is formed and the antireflection multilayer film 2 is manufactured. By adjusting the speed of the substrate 1 and the electric power of the sputtering device 19, a thin intermediate layer 5 of 10 Å or less, which does not impair the antireflection function of the optical thin film 3, can be formed, and
Since the spaces 12, 15, 17 are partitioned by the partition walls 9, 10, 11 so that the conductance is small, the spaces 15, 17 can be maintained at a gas pressure suitable for the process.

The targets of the sputtering devices 16a and 16c in the space 15 are TiO _x , and the remaining sputtering devices 16b and 1c.
The target of 6d is SiO _x , the target of the sputter device 19 in the space 12 is Ti, the evaporation material of behenic acid is in the evaporation source 18, and the space 15 is, for example, 10 ^{-2 to} 10 ^-4.
If Torr and space 17 are 10 ^-5 Torr, TiO _x and Si
The antireflection multilayer film 2 having the film structure shown in FIG. 4 having the Ti intermediate layer 5 between the optical thin film 3 in which four layers of O _X are alternately laminated and the water repellent layer 4 of behenic acid are obtained.

The antireflection multilayer film 2 thus manufactured is
Since the films are sequentially formed in a vacuum atmosphere, impurities such as H ₂ O, O ₂ , and N ₂ that deteriorate water repellency do not enter the film, and the Ti intermediate layer 5 is the uppermost optical thin film 3d. And T
Water-repellent layer 4 at the same time as chemical bonding of i-Si and Ti-O
In order to form a fatty acid salt by chemically bonding with the above, a normal tape peeling test, that is, peeling can be performed by scouring with a cotton wool impregnated with 100% ethanol at a load of 250 g / cm ² for 10 times at a speed of 2 cm / sec. As shown in FIG. 6, the water contact angle of the conventional one is 11
The water repellency is larger than 0 °, the water repellency is large, and the water repellency is not significantly deteriorated even when it is run, and the productivity is improved and the manufacturing cost can be reduced.

The water contact angle of the water-repellent layer 4 after the rubbing is
As shown in FIG. 6, it increases as the film pressure of the intermediate layer 5 increases, but becomes constant when the thickness is 10 Å or more,
Unlike the conventional one, it can maintain 110 ° even near 0Å.

[0022] For example the top layer of the optical thin film 3d is other than SiO _X TiO _X, even AlO _X, the intermediate layer 5 other than Ti Al, Si, Nb, Cr , Cu, Mg, Ta, Zr or their Even if the alloy composition is used, it is possible to obtain an antireflection multilayer film which is more resistant to peeling and has better water repellency than before. Also,
Even if the optical thin film 3 is formed by vapor deposition, the same effect as in the case where the optical thin film 3 is formed by sputtering is obtained. Similar effects were obtained when a film of polytetrafluoroethylene (trade name Teflon) was formed on the water-repellent layer 4 by sputtering or ion beam sputtering. The glass substrate 1 for building materials may be used instead of the polymer film substrate.

[0023]

[Example] Thickness 250 microns, width 1 m, length 500 m
1. An antireflection film having a water-repellent layer 4 of behenic acid on a substrate 1 of a PET film wound in a roll shape, using a device shown in FIG. The multilayer film 2 was formed. The optical thin film 3 has four alternating layers of TiO _x and SiO _x , and the optical thin film 3 and the intermediate layer 5 have 5 RF layers.
The water repellent layer 4 is formed by a magnetron sputtering device
It was vapor-deposited by a vapor deposition device of C resistance heating. The intermediate layer 5 was formed with five kinds of film thicknesses of 0, 5, 10, 15, 20 Å by changing the cathode power, and the water repellent layer 4 was 10 Å. The winding speed of the film substrate is 0.3 m / min, and other specifications are shown in Table 3.

[0024]

[Table 3]

The schematic structure of the antireflection multilayer film 2 thus obtained is similar to that shown in FIG. 4, and the relationship between the thickness of the intermediate layer of each film and the water contact angle is as shown by the white and black circles in FIG. It was
White circles are initial contact angles before labyrinth, and black circles are contact angles after labyrinth. The white triangles and the black triangles in the figure are the water contact angles before and after the labyrinth of the antireflection multilayer film having the film structure of FIG. 1A produced by the conventional apparatus of FIG. As is clear from this, the water contact angle of the antireflection multilayer film 2 produced by the method of the present invention is as large as 125 °, and even after the labyrinth has a sufficient water contact angle of 110 ° or more, and has good durability. You can see that it is water-based. Also,
This labyrinth was 1% at a speed of 250 g / cm ² and 2 cm / sec with absorbent cotton containing 100% ethanol.
It was carried out 0 times, but the water-repellent layer 4 was not peeled off. In the present invention, since the substrate 1 is not exposed to the atmosphere until the antireflection multilayer film 2 is completed, the production time is shorter than in the past.

[0026]

As described above, according to the present invention, an antireflection optical thin film composed of two or more layers made of two or more materials having different refractive indexes formed on a substrate such as a polymer film substrate and C , F, H, N, S, O, Si and other water repellent layers with a film thickness of 10 Å or less between Al, Ti, Si, N
Since the intermediate layer made of any one of b, Cr, Cu, Mg, Ta, and Zr is provided, the water-repellent layer is less likely to be peeled off, and the water-repellent property is improved. By manufacturing the antireflection multilayer film of, there is an effect that the antireflection multilayer film in which the water-repellent layer is difficult to peel off can be efficiently produced.
With the device configuration according to the fifth aspect, there is an effect that the method of the present invention can be accurately performed.

[Brief description of drawings]

FIG. 1 is a schematic structural diagram of a conventional antireflection multilayer film.

FIG. 2 is an explanatory view of a conventional manufacturing apparatus for an antireflection multilayer film.

FIG. 3 is a diagram showing the relationship between the time when an optical thin film of a conventional antireflection multilayer film is left in the air and the water contact angle.

FIG. 4 is a schematic structural diagram of an antireflection multilayer film of the present invention.

FIG. 5 is an explanatory view of an apparatus for producing an antireflection multilayer film of the present invention.

FIG. 6 is a diagram showing the relationship between the thickness of the intermediate layer and the water contact angle of the antireflection multilayer film of the present invention.

[Explanation of reference numerals] 1 substrate, 2 antireflection multilayer film, 3, 3a, 3b, 3
c, 3d optical thin film, 4 water repellent layer, 5 intermediate layer, 6 vacuum tank, 7, 8 film forming drum, 9, 10, 11 partition wall, 1
2, 15, 17 space, 16a, 16b, 16c, 16
d, 19 sputtering device, 18 evaporation source,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kafumi Ota 523 Yokota, Yamatake-cho, Sanmu-gun, Chiba Japan Vacuum Technology Co., Ltd. Chiba Institute for Supermaterials (72) Inventor Hisami Nakamura 523 Yokota, Yamatake-cho, Yamatake-gun, Chiba Prefecture Japan Vacuum Technology Co., Ltd. Chiba Institute for Super Materials

Claims (6)

[Claims] 1. An antireflection optical thin film of two or more layers is formed on a substrate by using two or more kinds of materials having different refractive indexes, and C, F, H, N, S, and A thin film of a polymer material composed of O, Si, or the like is formed as a water repellent layer in an antireflection multilayer film, and Al, Ti, Si having a film thickness of 10 Å or less is provided between the optical thin film and the water repellent layer. , Nb, Cr, Cu, Mg, T
An antireflection multilayer film provided with an intermediate layer composed of either a or Zr. 2. The intermediate layer is made of a material that is bonded to the uppermost thin film of the optical thin film and the water repellent layer by a chemical reaction, and the intermediate layer is formed on the optical thin film by sputtering or vapor deposition. The antireflection multilayer film according to claim 1, wherein a water-repellent layer is formed thereon by sputtering or vapor deposition. 3. The substrate, the optical thin film, the water repellent layer, and the intermediate layer are transparent, and the substrate is any one of glass, polyethylene terephthalate, and polymethylmethacrylate. Anti-reflection multilayer film. 4. An antireflection optical thin film made of two or more kinds of materials having different refractive indexes, and C, F, H, on a substrate.
A method for forming an antireflection multilayer film, which comprises sequentially forming a water-repellent layer of a polymer thin film composed of N, S, O, Si, etc. by sputtering or vapor deposition in a vacuum atmosphere. 5. An antireflection optical thin film made of two or more materials having different refractive indexes, Al, Ti, Si, N on a substrate.
In a vacuum atmosphere, an intermediate layer made of any one of b, Cr, Cu, Mg, Ta, and Zr, and a water-repellent layer of a polymer thin film made of C, F, H, N, S, O, Si, etc., in a vacuum atmosphere. A method for forming an antireflection multilayer film, which comprises sequentially forming films by sputtering or vapor deposition. 6. Two film-forming drums are rotatably provided in one vacuum chamber, the space around the film-forming drums is divided into three, and the space is surrounded by the peripheral surfaces of both film-forming drums. A part of the polymer film substrate is exposed and a roll and take-up roll of the polymer film substrate are arranged, and the remaining space is formed with two or more layers of optical thin films for antireflection with two or more materials having different refractive indexes. And a space provided with a plurality of evaporation sources or sputtering devices for forming a water repellent layer, and a space provided with an evaporation source or a sputtering device for forming a water-repellent layer. Al, Ti, Si, Nb, C on the molecular film substrate
An apparatus for producing an antireflection multilayer film, comprising an evaporation source or a sputtering device for forming an intermediate layer made of any one of r, Cu, Mg, Ta, and Zr.