JPH0682603A - Antireflective optical article and its surface reforming method - Google Patents

Abstract

PURPOSE:To prevent tarnish due to water, to obviate a decrease in adhesion due to water and to improve the durability of an antireflection coating by allowing an end-silanol org. silane compd. having a hydrophobic group with the surface of the coating. CONSTITUTION:A single or multiple-layered antireflection coating with the surface layer film consisting essentially of SiO2 is provided on the surface of a synthetic resin substrate to constitute an optical article. An end-silanol org. silane compd. is allowed to react with the surface of the coating. Trimethylsilanol, triethylsilanol, diphenylsilanediol, triphenylsilanol, 1,4-bis(hydroxyldimethylsilyl)benzene, etc., are exemplified as the silane compd. The silane compd. is applied on the surface by the dip, spinner or spray method and subjected to a reaction. The gaseous silane compd. is allowed to react with the coating surface in vacuum or in the atmosphere.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical article having an antireflection property and a method for modifying the surface condition thereof.

[0002]

2. Description of the Related Art Vacuum deposition method, ion plating method,
The inorganic coating film obtained by the sputtering method or the like is widely used for lenses, panels of display devices, antireflection films of various optical materials, hard coat films, various functional films, and the like. In particular, the SiO ₂ film is widely used because of its adhesion to the substrate, hardness, and ease of handling.

[0003]

However, when an inorganic coating film such as SiO ₂ is adhered with water droplets containing impurities such as Si, Na, Ca, etc., the impurities are deposited on the surface of the inorganic coating film during the drying process. The rest is firmly bonded to the inorganic coating film,
The so-called burn phenomenon occurs.

In addition, a film formed by vapor deposition generally has a lower density than a bulk film, and it is considered that water molecules, gas molecules and the like can easily move within the film. Therefore, water molecules are adsorbed on the surface of the film, and then reach the interface between the film and the substrate by diffusion,
This adversely affects the adhesiveness of the film, leading to a decrease in durability.

Therefore, the present invention is intended to solve such a problem, and an object thereof is to modify the surface condition of an optical article having an antireflection property to prevent the above-mentioned burn-off phenomenon. There is a function that can be solved on the surface.

[0006]

That is, an optical article having an antireflection property and a method for modifying the surface thereof according to the present invention include a single-layer or multi-layer structure in which a surface layer film provided on a synthetic resin substrate is mainly composed of SiO ₂ . It is characterized in that the surface of the antireflection film is reacted with a terminal silanol organosilane compound having hydrophobicity.

Further, the invention is characterized in that the gaseous silane compound is reacted in vacuum or in the atmosphere.

In order to treat an optical article having an antireflection property, the nature of the coating film already present on the substrate,
It is necessary to perform the treatment without lowering the adhesion and durability. For that purpose, the surface and the temperature of the environment where adhesion and durability are not deteriorated, and when processing anti-reflection coating, etc. It is desirable to carry out the reaction in the vicinity.

In order to impart water repellency to the surface of an optical article, conventionally known methods include thinly applying silicone oil or forming tetrafluoroethylene on the surface to increase the water repellency of the surface. There is. However, in these methods, the treating agent does not react with the surface and is not chemically bound to the surface. Therefore, the treating agent was easily removed from the surface by wiping or solvent. In addition, substances such as organopolysiloxanes having terminal silanols, which are thought to have a good affinity with SiO ₂ , have only a few silanol groups for long molecular chains, and sufficient adhesion can be achieved simply by coating and drying. I can't get sex. It is important to react the SiO ₂ surface with the treatment agent in order to obtain sufficient adhesion.

The silane compound used in the present invention undergoes a dehydration reaction with an inorganic coating film having a hydroxyl group, and is very effective for a reaction on the surface having a hydroxyl group.

For example, the following reaction is considered to occur near the surface of the SiO ₂ film.

[0012]

[Chemical 1]

In the present invention, a hydrophobic substance is used as the substituent other than the group involved in the reaction of the silane compound with the surface of the antireflection film.

The silane compound usable in the present invention includes:
Trimethylsilanol, triethylsilanol, diphenylsilanediol, triphenylsilanol, 1,4
-Bis (hydroxydimethylsilyl) benzene, and the like. In the present invention, it is needless to say that the present invention is not limited to these, and a structure having a bond of -Si-OH can achieve the object of the present invention. Further, in the present invention, the silane compounds used may combine with each other before or after the reaction with the surface of the antireflection film to form a polymer, which may be adjusted so as to obtain the degree of polymerization which is the object of the present invention. No problem whatsoever. Further, one or more kinds of silane compounds may be mixed and used depending on the purpose.

In the present invention, by using a silane compound having a hydrophobic group, it is possible to prevent burns due to water, improve the durability of the film, prevent the adhesion from decreasing due to water, and reduce the friction coefficient to improve the wear resistance. Benefits such as improvement can be obtained.

In order to react the silane compound on the surface of the antireflection film, a method of coating the silane compound on the surface and reacting it by a DiP method, a spinner method, a spray method or the like can be used. A solvent is required to dilute the silane compound. Further, a solvent for cleaning the silane compound that did not contribute to the reaction with the surface is also required. It is difficult to use a water-based or alcohol-based solvent having a hydroxyl group because the solvent and the silane compound react with each other and the solubility and the cleaning property are poor. Therefore, until now, it has been common to use a solvent harmful to the human body and a solvent harmful to the environment (for example, CFCs). CFCs are being abolished worldwide as ozone-depleting substances, and it is desirable to avoid their use in terms of environmental protection.

Further, in the case of the DiP method, the spinner method, and the spray method, it is necessary to take out an optical article having an antireflection property formed in a vacuum from the vacuum chamber to add a new step, and a washing step is additionally provided. It has to be and is not efficient. Therefore, as the reaction method, it is desirable to use a method of reacting the gas of the silane compound with the surface of the antireflection film in a vacuum atmosphere or in the air.

In the case of the DiP method or the like, the reaction rate can be controlled by controlling the atmosphere during coating, for example, the humidity and the temperature, and the desired treatment film can be controlled by adjusting the immersion time, the liquid temperature and the concentration of the silane compound. Can be obtained. Further, it is more effective if the reaction is promoted by performing heating or light irradiation to such an extent that the characteristics of the coat film are not affected after coating. When treating with a gaseous silane compound, the silane compound gas may be introduced and reacted after forming the antireflection film in a vacuum chamber. After forming the antireflection film, it is also possible to introduce a gas of a silane compound into a plasma atmosphere of argon, oxygen or the like, and perform reactive vapor deposition, reactive ion plating or the like.

It is effective to perform cleaning, chemical treatment, or plasma treatment on the surface of the antireflection film as a pretreatment for increasing the reactivity with the silane compound.

The silane compound used in the reaction may be used alone or as a mixture, or may be diluted with a solvent or pretreated with an acid or a base before use.

After the reaction is completed, the silane compound that has reacted with moisture in the atmosphere and the silane compound that could not contribute to the reaction with the surface of the antireflection film are washed away to change the appearance such as the antireflection property before the treatment. No processing can be done.

In the processing described so far, the surface layer film is mainly S.
consisting iO ₂ can be a single or multi-layer anti-reflection film surface. Hereinafter, the present invention will be described in detail based on Examples, but the present invention is not limited thereto.

[0023]

【Example】

(Example 1) A synthetic resin lens made of a resin made of diethylene glycol bis (allyl carbonate) was washed with acetone, and then the resin surface was subjected to an antireflection treatment at a substrate temperature of 50 ° C by a vacuum deposition method. The film structure was such that the SiO ₂ layer was λ / 4 from the lens side, the total film thickness of the ZrO ₂ layer and the SiO ₂ layer was λ / 4, the ZrO ₂ layer was λ / 4, and the uppermost SiO ₂ layer was λ / 4. (Where λ = 520 nm). Next, this lens was washed with isopropyl alcohol, dried sufficiently, and then dipped in a solution of 50 g of trimethylsilanol and 450 g of tetrahydrofuran mixed at a liquid temperature of 10 ° C. for 3 minutes.
After the immersion, it was left for 15 minutes in an atmosphere having a humidity of 75% and a temperature of 50 ° C., and then washed with acetone.

No significant change was observed in the appearance and antireflection characteristics of the lens after washing.

The evaluation method of the obtained coat film was as follows.

Burnability: Tap water was poured on the surface of the coating film, and the coating film was dried, and then the residue was wiped off with a cloth.

A: Completely wiped off B: Partial residue remained C: Almost residue left abrasion resistance: The surface of the coated film was rubbed 1000 times with a cloth (cotton) under a load of 1 kg. The degree of scratches is the following 3
The evaluation was divided into stages.

A: No scratches B: 1 to 10 fine scratches C: Countless fine scratches Adhesion: After dipping in pure water at 37 ° C. for 1 week, the adhesion of the coat film was examined. It was

A cross-cut tape test was conducted according to JIS D-0202. That is, using a knife,
Incisions are made on the surface of the substrate at 1 mm intervals to form 1 cm ² squares. Next, after strongly sticking a cellophane adhesive tape (“Cellotape” manufactured by Nitto Kagaku Co., Ltd.) on it, it was pulled by 90 ° from the surface and peeled off. Was used as an index.

Contact angle: Measured by a droplet method using a contact angle meter (CA-D type manufactured by Kyowa Chemical Co., Ltd.).

Example 2 Using the lens before the treatment with the silane compound in Example 1, the treatment was carried out by the following method.

3 g of a mixture of 100 g of triethylsilanol and 300 g of tetrahydrofuran at a liquid temperature of 20 ° C.
After soaking for 0 second, it was left for 1 minute in diethylamine vapor and washed with water. The evaluation method of the obtained coat film is described in Example 1.
The evaluation was performed according to the evaluation method shown in.

(Embodiment 3) In Embodiment 1, the uppermost layer is SiO ₂
After forming the layer, the SiO ₂ surface was treated with argon plasma for 1 minute, and then trimethylsilanol was added at 5 cc / m 2.
It was introduced into the vacuum chamber at a ratio of in for 2 minutes. The surface temperature at that time was 60 ° C. After that, the lens was taken out into the atmosphere. The appearance was almost unchanged from that before the treatment. The evaluation method of the obtained coat film was performed according to Example 1.

Example 4 An acrylic plate washed with isopropyl alcohol was coated with the coating liquid described below by a dipping method at a liquid temperature of 5 ° C. and a pulling rate of 2
After coating at 0 cm / min, 70 ℃ in a hot air drying oven
And heat-cured for 5 hours, and further, the distance between the germicidal lamp (GL-10 manufactured by Toshiba Corp.) and the acrylic plate was set to 10 cm,
Light irradiation was performed for 30 seconds.

The coating liquid was prepared as follows.

200 g of ethanol and 180 g of ethanol-dispersed colloidal silica in a reaction vessel equipped with a stirring device.
(Catalyst Kasei Co., Ltd. "Oscar 1232"), γ-
45 g of methacrylooxypropyltrimethoxysilane,
γ-glycidoxypropyltrimethoxysilane 30 g,
A flow control agent (0.5 g), aluminum acetylacetonate (3 g) and 0.05N nitric acid (40 g) were added, and the mixture was stirred at room temperature for 2 hours to give a coating solution.

The acrylic plate obtained as described above was subjected to antireflection treatment in the same manner as in Example 1, and then immersed in a solution having a liquid temperature of 10 ° C. mixed with 15 g of diphenylsilanediol and 240 g of methyl cellosolve for 2 minutes. Then, it was left for 10 minutes in an atmosphere having a humidity of 70% and a temperature of 40 ° C.
Then, washing with water and washing with acetone were performed. No particular change was observed in the appearance after washing. The evaluation method of the obtained coat film was performed according to Example 1.

Comparative Example 1 A synthetic resin lens having an antireflection film before the treatment with the silane compound obtained in Example 1 was used as Comparative Example 1.

Comparative Example 2 An acrylic plate with an antireflection film before the treatment with the silane compound obtained in Example 4 was used as Comparative Example 2.

The evaluation results of Examples 1 to 4 and Comparative Examples 1 and 2 are summarized in Table 1.

[0041]

[Table 1]

[0042]

By reacting the surface of the optical article having antireflection property with the hydrophobic silane compound, the physical properties of the surface of the optical article are changed, and the characteristics of the optical article can be remarkably changed. By imparting hydrophobicity to the surface, the bond between water and impurities contained therein and the surface of the optical article is weakened, which leads to prevention of the burn phenomenon.

Further, since it is hydrophobic, the surface acts as a filter against water, and it is possible to prevent deterioration of the durability of the entire antireflection film due to water. Further, the friction coefficient on the surface is reduced, so that the dirt and the like that have adhered are better slipped and the wear resistance is improved. In addition, water drops easily fall off the membrane, which is convenient on rainy days.

When the method of reacting a gaseous silane compound is used, it is not necessary to use a solvent (for example, chlorofluorocarbon), and a treatment friendly to the earth becomes possible.

Since the present invention has such effects,
Synthetic resin eyeglass lens, camera lens, display panel,
It can be applied to optical components having antireflection properties such as watch glass and window glass.

Claims (4)

[Claims] 1. A surface layer film provided on a synthetic resin base material is obtained by reacting a terminal silanol organosilane compound having a hydrophobic group on the surface of a single-layer or multilayer antireflection film mainly composed of SiO _2. An optical article having antireflection property. 2. The optical article having antireflection properties according to claim 1, wherein the optical article having antireflection properties is a synthetic resin lens or a synthetic resin lens having a hard coat layer. 3. The optical article having antireflection properties according to claim 2, wherein the synthetic resin lens is an eyeglass lens. 4. The surface layer film is mainly composed of SiO 2 on the surface of the base material.
The monolayer or multilayer antireflection film consisting of _{2. The} term inorganic is provided, the anti-reflection properties, characterized in that is reacted terminal silanol organic silane compound having a hydrophobic group of gases in vacuum or in the atmosphere on the surface A method for modifying the surface of an optical article having the following.