JPH0781978A - Water-repellent antireflection film in glass optical parts - Google Patents

Abstract

PURPOSE:To form a water-repellent antireflection film by applying a dil. soln. of transparent fluororesin on the uppermost layer of the metal fluoride antireflection film consisting of >=1 layer on the surface of a glass optical product, heating and curing the resin. CONSTITUTION:A transparent fluororesin diluted with a fluoric solvent, etc., is applied by dip coating, etc., on an antireflection film formed on a glass substrate to form a water-repellent film having a desired optical thickness of <=10nm, and the film is heated at >=80 deg.C and cured. Consequently, the monomers are combined to form a rigid amorphous polymer, the fluorine in the uppermost layer of the antireflection film is cross-linked to the amorphous polymer, adhesion is chemically improved, and durability is enhanced. The antireflection film consists of metal oxide, metal fluoride and metal nitride, and the uppermost layer of the film is formed with a metal fluoride such as MgF2, AIF3, BaF2, LiF, CaF2, Na3AlF6 and Na5Al3F14. The antireflection film is formed by vacuum deposition, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antireflection film having water repellency.

[0002]

2. Description of the Related Art Conventionally, there has been known a method of forming an antireflection film composed of a thin film of a metal oxide, a metal fluoride, a metal nitride or the like on a glass surface. This method is used for optical parts such as optical lenses, spectacle lenses and filters. In general, the antireflection film is formed by a vacuum vapor deposition method. In the case of inorganic glass, the inorganic glass can be heated for vapor deposition, so that the adhesion between the inorganic glass and the vapor deposition film is good and a strong film is formed. Can be formed.

However, when an optical component is used under high humidity, there are problems that cloudy water is generated on the surface of the optical component and that oil that adheres due to contact with a human body is difficult to remove.

In order to solve such a problem, for example, as a similar technique, as shown in Japanese Patent Laid-Open No. 64-86101, organosilicon is provided on the outermost layer SiO ₂ of the antireflection film provided on the surface of the substrate because of its low refractive index. Techniques have been proposed for forming compounds containing substituents. The above-mentioned film structure is characterized by having water repellency and oil repellency and not impairing antireflection property.

[0005]

However, the structure of the antireflection film having the water repellent film described in JP-A-64-86101 cannot be expected to have sufficient optical characteristics to be applied on the glass substrate. The outermost layer SiO ₂ of the antireflection film has a high refractive index of 1.46, and the compound containing an organic silicon substituent formed as a water repellent layer also has a refractive index of about 1.4.
It is as high as 5.

With this, it is not possible to obtain sufficient optical characteristics for application to optical parts. Further, when a compound containing an organosilicon substituent is formed on a metal fluoride to form an antireflection film having water repellency, the adhesion between the metal fluoride and the water repellent film is poor regardless of the film thickness. Due to poor scratch resistance, water repellency deteriorates.

Therefore, the present invention was developed in view of the above-mentioned drawbacks in the prior art, and is excellent in that the surface of a glass optical component is provided with a water-repellent film having excellent water repellency and scratch resistance. An object is to provide an antireflection film having optical properties.

[0008]

The present invention provides a desired film having an optical thickness of 10 nm or less obtained by diluting a transparent fluororesin with a fluorine-based solvent or the like on an antireflection film formed on the surface of a glass substrate. Form with a thick thickness. Materials constituting the antireflection film are metal oxides, metal fluorides, metal nitrides, etc.,
The low refractive index material of the uppermost layer of the antireflection film is MgF ₂ , AlF
It is composed of metal fluorides such as ₃ , BaF ₂ , LiF, CaF ₂ , Na ₃ AlF ₆ and Na ₅ Al ₃ F ₁₄ .

The method for forming these antireflection films is as follows.
The method is not limited to the vacuum vapor deposition method, the ion plating method and the sputtering method. The fluororesin used as the water-repellent film has a transparent thermosetting property and is a transparent fluorine diluted with a fluorine-based solvent or the like so as to form a desired film thickness of 10 nm or less on the antireflection film. After the resin is formed by the dipping method (immersion) or the spinner method, it is cured by heating at 80 ° C. or higher to form a desired film thickness.

[0010]

In the antireflection film having water repellency in the glass optical component having such a structure, the first layer from the air side is made of transparent fluororesin. The water-repellent layer having an optical film thickness of 10 nm or less exists on the antireflection film in a monomer state before heating, but by heating at 80 ° C. or more, the individually existing monomers are bonded. To form a strong amorphous polymer. At the same time, a cross-linking reaction occurs between the fluorine and the amorphous polymer in the outermost layer of the antireflection film, and the adhesion between the antireflection film and the water repellent film is chemically improved, so that the durability is improved.

Further, by using a metal fluoride having a low refractive index as the outermost layer of the antireflection film, excellent optical characteristics can be obtained. The transparent fluororesin used for the antireflection film having water repellency can be controlled to a desired film thickness and can be controlled with an ultrathin film because of its property of being easily diluted with a fluorine-based solvent or the like.

Therefore, by forming the transparent fluororesin with an optical film thickness of 10 nm or less, it is possible to form a film that does not impair the water repellency and the scratch resistance of the film and does not affect optically. If the thickness exceeds this thickness, the scratch resistance of the water-repellent film deteriorates, and the water-repellent film is scraped off due to scratches, and therefore exhibits optical characteristics different from the initial level at a problematic level.

[0013]

EXAMPLES Hereinafter, the antireflection film having water repellency in the glass optical component of the present invention will be described in detail with reference to Examples and evaluated according to the test described later.

[0014]

Example 1 In this example, a glass substrate having a diameter of 30 mm (BK7 manufactured by SCHOTT) was used as a chamber having a diameter of 560 mm.
After setting in the vacuum deposition equipment of
Evacuate to a high vacuum of ^10-5 Torr or less. For the exhaust system, use a diffusion pump with a cold trap or a cryopump. Substrate heating at 300 ° C
At an evaporation rate of 0.5 ~ by the electron beam heating method.
First from the substrate in Table 1 under the condition of 1.0 nm / sec.
An antireflection coating consisting of layers was deposited.

As the water-repellent layer, a transparent fluororesin (CYTOP, Asahi Glass Co., Ltd.) having an optical film thickness of 9.5 nm was formed on the second layer using a spinner. After the vapor deposition, the thoroughly washed substrate was set on the spinner rotating part, and the solvent diluted to 0.005% by weight was added to the spinner rotating center for 0.5 m.
1 drop, the primary rotation speed is 3000 RPM for 1 sec,
The secondary rotation speed was 5000 rpm for 4 seconds.
The obtained substrate was placed in a heating furnace and cured at 180 ° C. for 1 hour. Thus, an antireflection film having water repellency in the glass optical component of Example 1 having the spectral characteristics shown in FIG. 1 was manufactured.

[0016]

[Table 1]

The results of evaluation of water repellency and scratch resistance of the antireflection film of this example are shown in Table 6, and the spectral characteristics after the scratch resistance test are shown in FIG. The antireflection film having water repellency in the glass optical component of this example exhibited high water repellency and excellent scratch resistance, and the spectral characteristics were not deteriorated.

[0018]

[Embodiment 2] In this embodiment, an antireflection film consisting of two layers having the film thickness shown in Table 2 is formed by using the same method as in Embodiment 1, and then, as a water repellent layer, the third layer is formed. , A transparent fluororesin (Cytop, Asahi Glass Co., Ltd.) diluted to 0.006 wt% was formed to an optical film thickness of 10 nm using a spinner, and the results are shown in Table 2 and the spectral characteristics of Example 2 of FIG. An antireflection film having water repellency in a glass optical component was manufactured.

[0019]

[Table 2]

The results of evaluating the water repellency and scratch resistance of the antireflection film of this example are shown in Table 6, and the spectral characteristics after the scratch resistance test are shown in FIG. Similar to Example 1, the water-repellent antireflection film in the glass optical component of this example also showed high water repellency and excellent scratch resistance, and no change was observed in the spectral characteristics.

[0021]

Example 3 In this example, a glass substrate having a diameter of 30 mm (BK11 manufactured by SCHOTT) was vapor-deposited with the first to third antireflection films from the substrate shown in Table 3 under the same conditions as in Example 1. As the water-repellent layer, a transparent fluororesin (Cytop Co., Ltd., Asahi Glass Co., Ltd.) having an optical film thickness of 7 nm was formed on the fourth layer by dipping. After vapor deposition, a sufficiently washed substrate is set in a holder, dipped in a solvent diluted to 0.1% by weight, and pulled up at 6 cm / min parallel to the film forming surface. The obtained substrate was put in a heating furnace and cured at 180 ° C. for 1 hour. Thus, an antireflection film having water repellency in the glass optical component of Example 3 having the spectral characteristics shown in FIG. 5 was manufactured.

[0022]

[Table 3]

Table 6 shows the results of evaluating the water repellency and scratch resistance of the antireflection film of this example, and FIG. 6 shows the spectral characteristics after the scratch resistance test. As in the case of Example 1, the water-repellent antireflection film of the glass optical component of this example also exhibited high water repellency and excellent scratch resistance, and no change was observed in the spectral characteristics.

[0024]

COMPARATIVE EXAMPLE 1 In Example 1, an antireflection film having a film thickness shown in Table 4 and a spectral characteristic shown in FIG. The results of evaluation of water repellency and scratch resistance of the antireflection film of Comparative Example 1 are shown in Table 6, and the spectral characteristics after the scratch resistance test are shown in FIG. The antireflection film of Comparative Example 1 had good scratch resistance, but did not show water repellency.

[0025]

[Table 4]

[0026]

Comparative Example 2 An antireflection film having the film thickness shown in Table 5 was formed in the same manner as in Example 1, and then, as a water repellent layer, transparent fluorine diluted to 0.007% by weight was used as the third layer. By forming a resin (Asahi Glass Co., Ltd. Cytop) with a spinner to an optical film thickness of 10.5 nm, the spectral characteristics of FIG. 9 are obtained, and the glass optical component of Comparative Example 2 has water-repellent antireflection. A membrane was produced.

[0027]

[Table 5]

The results of evaluating the water repellency and scratch resistance of the antireflection film of Comparative Example 2 are shown in Table 6, and the spectral characteristics after the scratch resistance test are shown in FIG. In the antireflection film of Comparative Example 2, since the water-repellent film is too thick, peeling of the film occurs in the scratch resistance test, and the peak shifts to the short wavelength side as the reflectance on the long wavelength side increases in the spectral characteristics. There was a problematic change in level.

The performance of the obtained glass optical component was tested according to the following method. (1) Static Contact Angle to Water Using a contact angle meter, a water drop having a diameter of 1.7 mm was made at the tip of the needle at room temperature, and this was brought into contact with a glass substrate to make a water drop. The angle between this water drop and the surface was measured quickly. (2) Scratch resistance Steel wool (# 000) is approximately 150 gf / cm
After rubbing 50 times at a pressure of ² , the presence or absence of scratches and changes in spectral characteristics were evaluated.

The water-repellent antireflection film of the glass optical component of the present invention exhibited higher water repellency and excellent scratch resistance as compared with Comparative Examples 1 and 2. Similar effects were obtained even when the outermost layer of the antireflection film was a metal fluoride other than those in the above-mentioned examples. Further, in the antireflection film, other materials except the uppermost layer are SiO ₂ , SiO, ZrO ₂ , Al ₂
O ₃ , TiO, TiO ₂ , Ti ₂ O ₃ , Y ₂ O ₃ , Yb
Oxides such as ₂ O ₃ , MgO, Ta ₂ O ₅ , CeO ₂ , and HfO ₂ , MgF ₂ , AlF ₃ , BaF ₃ , LiF, Ca
Similar effects were obtained by using a fluoride such as F ₂ , Na ₃ AlF ₆ , Na ₅ Al ₃ F ₁₄ , a nitride such as Si ₃ N ₄ , or a mixture of two or more thereof.

[0031]

[Table 6]

[0032]

As described above, according to the antireflection film having water repellency in the glass optical component according to the present invention, the glass is formed by the ultrathin water repellent film which does not impair the effect of the antireflection film. Water repellency with high performance and excellent scratch resistance was imparted to the surface of optical parts. Dust and the like attached due to the decrease in surface energy are very easily removed, and organic substances such as sweat and oil secreted by the human body attached to the surface can be easily wiped off. No strong wiping is required to remove stains on the glass optical component, and the antireflection film is not damaged. It has the above excellent features.

[Brief description of drawings]

FIG. 1 is a graph showing Example 1.

2 is a graph showing Example 1. FIG.

FIG. 3 is a graph showing Example 2.

FIG. 4 is a graph showing Example 2.

FIG. 5 is a graph showing Example 3.

FIG. 6 is a graph showing Example 3.

FIG. 7 is a graph showing Comparative Example 1.

FIG. 8 is a graph showing Comparative Example 1.

9 is a graph showing Comparative Example 2. FIG.

FIG. 10 is a graph showing Comparative Example 2.

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[Procedure amendment]

[Submission date] December 22, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

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[Figure 8]

[Figure 9]

[Figure 10]

Claims (1)

[Claims] 1. An antireflection film formed on the surface of a glass optical component, wherein at least one layer is formed, and the uppermost layer is a metal fluoride antireflection film and a diluting solution of a transparent fluororesin is dipped on the antireflection film. Water-repellent antireflection film having a water-repellent layer of a transparent fluororesin having an optical film thickness of 10 nm or less formed by applying by a coating method or a spinner method and heating and curing. .