JP2000094567A - Method of forming antifouling layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent contaminants such as a fingerprint, a dermal lipide, sweat and cosmetics from sticking onto the surface of various kinds of an optical members without the use of a diluent solvent by impregnating a porous molded product with a stainproofing agent containing a specific organic silane compound and heating the molded product in vacuum. SOLUTION: A porous molded product is impregnated with a stainproofing agent containing an organic silane compound represented by the formula and then is heated in a vacuum and further, the stainproofing agent is evaporated to form a coating film on a base material to be treated. If required, the coating film is heated, humidified, irradiated with ultraviolet rays or irradiated with an electron beam or treated by any other means. In the formula, R1 is a 1-16C straight-chain or branched perfluoroalkyl group; n is an integer of 1-50; m is an integer of 0-3; 1 is an integer of 0-3; s is an integer of 0-6, provided, that 6 >=m+1>0; and R is a hydrolytic group. The porous molded product is composed of SiO2, TiO2, MgO, Cu, Fe, Al, stainless steel, carbon and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an antifouling layer, and more particularly to a method for forming an antifouling layer on a surface of a substrate to be treated which requires antifouling performance. is there. In particular, various optical members (optical lenses, spectacle lenses, lenses of cameras and binoculars, or other optical devices, beam splitters, prisms, mirrors, window glasses, antireflection films, optical filters, etc.) as substrates to be processed.
The present invention relates to a method for forming an antifouling layer on the surface of the optical member, which allows the formation of the antifouling layer without impairing the optical performance of these various optical members.

[0002]

2. Description of the Related Art Conventionally, optical lenses, spectacle lenses, and lenses such as cameras and binoculars are usually provided with an antireflection treatment on the surface thereof in order to reduce the reflection of light and increase the transmittance of light. . When these optical members are used by humans, stains such as fingerprints, sebum, sweat, and cosmetics often adhere. Generally, since the surface energy of the antireflection film is as large as about 60 J / m ² , such dirt easily adheres to the surface, and it is not easy to remove it due to the presence of fine irregularities. In addition, there is a problem that high reflection occurs only in a portion where such dirt adheres, and the dirt is conspicuous.

[0003] Therefore, as means for solving the problem of dirt, there has been devised a method of providing an antifouling layer having a property that dirt hardly adheres and that can easily be wiped off even if it adheres. For example, Japanese Patent Application Laid-Open No. 64-86101 discloses an antireflection film mainly composed of silicon dioxide provided on the surface of a base material, and further, the surface thereof is treated with a compound containing an organic silicon substituent to prevent contamination and abrasion. Anti-reflective coating articles have been proposed.
Japanese Patent Application Laid-Open No. 4-338901 proposes a stain-resistant and scratch-resistant CRT filter in which a silanol-organic polysiloxane is coated on the surface of a substrate. Japanese Patent Publication No. 6-29332 discloses a low reflectivity and antifouling property having an antireflection film made of a mono- and disilane compound containing a polyfluoroalkyl group and a silane compound of halogen, alkyl or alkoxy on a plastic surface. Plastic has been proposed. Further, JP-A-7-16940 proposes an optical article in which a copolymer of a perfluoroalkyl (meth) acrylate and a monomer having an alkoxysilane group is formed on an optical thin film mainly composed of silicon dioxide. Have been.

[0004]

However, the above-described conventional antifouling layer forming technique has insufficient antifouling properties, and in particular, it is difficult to wipe off dirt such as fingerprints, sebum, sweat, and cosmetics. However, there is a problem that the antifouling performance is greatly reduced with use. Therefore, an optical member excellent in antifouling property and durability is desired.

An object of the present invention is to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a fingerprint, a fingerprint, or the like on a surface of a substrate to be processed such as various optical members without using a diluting solvent. Prevents the attachment of dirt such as sebum, sweat, and cosmetics, and easily forms the antifouling layer with excellent antifouling properties so that it can be easily wiped off even if it adheres. Is to provide a way to

[0006]

Means for Solving the Problems To solve the above problems, the invention of claim 1 is to impregnate an antifouling agent containing an organic silane compound represented by the following general formula (1) into a porous molded product, In vacuum, it is heated, the antifouling agent is evaporated to form a film on the substrate to be treated, and if necessary, heating, humidification, ultraviolet irradiation, or electron beam irradiation is performed. This is a method for forming an antifouling layer.

[0007]

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(Where R _f is a linear or branched perfluoroalkyl group having 1 to 16 carbon atoms, n is an integer of 1 to 50, m is an integer of 0 to 3, l is an integer of 0 to 3, s is 0-6
Where 6 ≧ m + 1> 0 and R represents a hydrolyzable group. )

According to a second aspect of the present invention, in the method for forming an antifouling layer according to the first aspect, the porous molded product is made of S
iO ₂ , TiO ₂ , ZrO ₂ , MgO, Al ₂ O ₃ , C
aSO ₄ , Cu, Fe, Al, stainless steel, carbon, etc., or a mixture of two or more thereof.

[0010] According to a third aspect of the present invention, in the method for forming an antifouling layer according to the first or second aspect, the heating method for evaporating the antifouling agent in the porous molded product is a resistive method. It is at least one heating method selected from a heating method, an EB heating method, and a light heating method.

According to a fourth aspect of the present invention, in the method for forming an antifouling layer according to any one of the first to third aspects, the substrate to be processed is an optical lens, an eyeglass lens, a camera or binoculars. Or an optical member of another optical device, such as a lens, a beam splitter, a prism, a mirror, a window glass, an antireflection film, an optical filter, or the like.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The antifouling agent of the present invention is characterized by containing the organic silane compound represented by the general formula (1). The general formula (1)
In the formula, R _f is a linear or branched perfluoroalkyl group having 1 to 16 carbon atoms, and in particular, CF ₃ —, C ₂
F ₅ — and C ₃ F ₇ — are preferred. R is a hydrolyzing group, —Cl, —Br, —l, —OR ¹ , —OOCR ¹ ,
^{-OC (R 1) C = C} (R 2) 2, -ON = C (R 1)
^{_{2, -ON = CR 3, -N}} (R 2) 2, -R 2 NOCR
^{1 and the} like are preferable. Here, R ¹ is an aliphatic hydrocarbon group having 1 to 10 carbon atoms such as an alkyl group, or an aromatic hydrocarbon group having 6 to 20 carbon atoms such as a phenyl group, and R ² is a carbon atom such as a hydrogen atom or an alkyl group. An aliphatic hydrocarbon group having 1 to 5 and R ³ are a divalent aliphatic hydrocarbon group having 3 to 6 carbon atoms such as an alkylidene group. In the general formula (1),
The hydrolyzable group R can be used not only as one kind but also as a mixture of two or more kinds. In particular, -OCH ₃ ,
—OC ₂ H ₅ , —OOCCH ₃ , and —NH ₂ are preferable.
N is an integer of 1 to 50; m is an integer of 0 to 3;
And s is an integer of 1 to 6, provided that 6 ≧ m +
l> 0. For example, the organosilane compound represented by the general formula (1) can be produced according to the following reaction formula (1).

[0013]

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Fluorine resin containing a hydroxyl group [R _f- (O
_{C 3 F 6) n-O-} (CF 2) m- (CH 2) l -O
H: provided that R ₁ is a linear or branched perfluoroalkyl group having ₁ to 16 carbon atoms, n is an integer of 1 to 50, and m is 0
An integer from 1 to 3, and l is an integer from 0 to 3. ] In a solvent
aH and a halogen-based silane coupling agent [X- (CH
₂ ) s-Si (R) ₃ : wherein X is a halogen element, s is an integer of 0 to 6, and R is a hydrolyzable group. To obtain an organosilane compound.

The reaction is carried out by reacting 1 m of a fluororesin containing a hydroxyl group.
The reaction proceeds advantageously at room temperature to a temperature at which the solvent is refluxed for 2 to 72 hours using NaH in an excess of 1 to 1.1 and a halogen-based silane coupling agent in an excess of 1 to ol. As a solvent, perfluorohexane,
Perfluoromethylcyclohexane, perfluoro-
Normal carbon number 5 such as 1,3-dimethylcyclohexane
In addition to perfluoroaliphatic hydrocarbons, bis (trifluoromethyl) benzene, etc., fluorinated aromatic hydrocarbons, fluorinated aliphatic hydrocarbons and the like can be used.

In the present invention, in order to form an antifouling layer on the substrate to be treated, the above-mentioned antifouling agent is impregnated into a porous molded product, heated in a vacuum, and evaporated. Then, a film is formed on the substrate to be processed. If necessary, after film formation, heating, humidification, ultraviolet irradiation, electron beam irradiation, etc. are performed.

As a heating method for evaporating the antifouling agent by heating the porous molded product impregnated with the antifouling agent, a resistance heating method, an EB heating method, and a light heating method are effective.

The component of the porous molded product is SiO.
_{2, TiO 2, ZrO 2,} MgO, Al 2 O 3, CaS
O ₄ , Cu, Fe, Al, stainless steel, carbon, etc.
Or a mixture of two or more of these. These materials have, for example, a finely divided shape having a particle size typically in the range of 5 to 20 μm, pelletize it and then sinter these pellets in the usual manner for each material. By doing so, the porous molded article can be adjusted.

The sintering step of the pellet is generally 1 to 1
It is carried out at a temperature of 700-1400 ° C. for 0 hours. Depending on the particle size of the primary particles, enrichment and sintering conditions, the resulting porous molding has a porosity of 30-60%. Since the amount of the pellet holding the antifouling agent depends on the porosity and the size of the pores of the pellet, it is possible to control the amount of the antifouling agent held in the pellet in the pellet manufacturing process.

On the other hand, from the viewpoint of controlling the working environment when forming the antifouling layer and controlling the film thickness of the antifouling layer, it is preferable to use a dry coating method that does not require a diluting solvent, and particularly preferable to use a vacuum deposition method. . According to the dry coating method, the thickness of the antifouling layer, which has conventionally been difficult, can be accurately controlled on the order of angstroms, and an optical member having a desired antifouling layer can be provided. Further, with respect to the optical member having the antireflection film, the antifouling property can be easily imparted without changing the interference color of the antireflection layer for which color setting is difficult.

When the antifouling layer is formed by a dry coating method, its thickness changes depending on the evaporation amount of the antifouling agent. Therefore, in order to control the thickness of the antifouling layer,
It is preferable to control the amount of evaporation of the antifouling agent accurately. The evaporation amount of the antifouling agent is determined by the amount of the antifouling agent impregnated in the porous molded article and the heating conditions during film formation.

The film thickness of the antifouling layer prepared using the antifouling agent is not particularly limited, but is preferably 10 to 10 from the viewpoints of antifouling property, scratch resistance, and optical performance of the optical member. 500
Å is preferred.

As the substrate to be used in the present invention, specifically, for example, an optical lens, an eyeglass lens,
Lenses, beam splitters, prisms, mirrors, windowpanes, anti-reflective layers for cameras and binoculars or other optical devices,
An optical member such as an optical filter can be used.

[0024]

Embodiments of the present invention will be described below in detail, but the present invention is not limited to the embodiments. [(1) Preparation of porous molded product] Al having a particle size of 1 to 10 μm
Pellets of 6 mm in diameter and 4 mm in height were produced from ₂ O ₃ using a hydraulic press. The pellet was then sintered at 1200 ° C. for 14 hours. The sintered and shaped article (pellet) has a porosity of about 40%.

(Example 1) [(2) Preparation of antifouling agent] A sodium hydride / oil suspension was placed in a 100 ml two-necked eggplant type flask equipped with a dropping funnel and a reflux condenser, and the atmosphere was replaced with nitrogen.
After the replacement, washing with n-hexane under nitrogen is performed 4 times.
Repeated times, n-hexane was distilled off under reduced pressure to obtain sodium hydride (0.011 mol).

A hydroxyl group-containing fluororesin (0.01 mol) represented by the following formula (1) is dissolved in 50 g of bis (trifluoromethyl) benzene, and the solution is gently cooled at a rate of 1 drop / sec under ice-cooling. Was dropped. After completion of the dropwise addition, the temperature was changed from an ice bath to room temperature, and the mixture was stirred for about 10 hours. Chloromethyltrimethoxysilane (0.1 mol) represented by the following formula (2) is added to the sodium alkoxide, and the mixture is stirred at room temperature for 2 hours, and then heated and refluxed for 72 hours while controlling the heating temperature at 90 ° C. went. After the completion of the reflux, unreacted sodium hydride and sodium chloride were filtered under reduced pressure, the filtrate was sufficiently washed with water, and bis (trifluoromethyl) benzene and excess chloromethyltrimethoxysilane were distilled off under reduced pressure. An organosilane compound represented by 3) was obtained.

[0027]

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[0028]

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[0029]

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5 g of the organosilane compound represented by the above formula (3) was diluted to 10 wt% with perfluorohexane to prepare an antifouling agent. The above porous molded product (pellet)
And impregnate it so that it is completely saturated. After removal from the solution and evaporation of the solvent, each pellet contains about 2% by weight of an antifouling agent.

[(4) Preparation of antifouling layer] The above-mentioned pellet was put on a molybdenum boat, and formed on a spectacle lens with an antireflection film by a vacuum evaporation method (resistance heating method) to prepare an antifouling layer. . After evacuating the inside of the vacuum deposition machine to 5 × 10 ⁻⁵ Torr or less, the boat was heated to 400 ° C. to evaporate the antifouling agent.

Comparative Example 1 CF ₃ (CF ₂ ) ₇ (CH
₂ ) Using ₂ Si (NH) _3/2 [KP801M: manufactured by Shin-Etsu Chemical Co., Ltd.], an antifouling layer was formed on a spectacle lens with an antireflection film in the same manner as in Example 1.

With respect to the spectacle lens with an antireflection film formed with an antifouling layer prepared in Example 1 and Comparative Example 1, the contact angle, the falling angle, the adhesion and wiping properties of an oil-based pen, the adhesion and wiping of fingerprints, and the like. Table 1 shows the results of evaluation of the properties and the like according to the following evaluation methods. In Table 1, the values in parentheses indicate the characteristics after the wear resistance test.

Evaluation method: (a) Measurement of contact angle: Using a contact angle meter [CA-X: manufactured by Kyowa Interface Science Co., Ltd.] in a dry state (20 ° C.-65% R)
In H), a droplet having a diameter of 1.0 mm was formed at the tip of the needle, and this was brought into contact with the surface of the substrate (solid) to form a droplet. The contact angle is an angle formed by a tangent to the liquid surface at a point where the solid and the liquid come into contact with each other, and is defined as an angle including the liquid. Distilled water and n-hexadecane were used as the liquid.

(B) Fall angle measurement: Fall angle meter [CA-X
(Type: manufactured by Kyowa Interface Science Co., Ltd.)
(C-65% RH), a droplet having a diameter of 1.0 mm was formed at the needle tip, and this was brought into contact with a horizontal substrate (solid) surface to form a droplet. Next, when this solid sample is gradually tilted, the droplet gradually deforms, and when the tilt angle reaches a certain angle,
The droplet slides down. The inclination angle at this time was defined as the falling angle. Distilled water and n-hexadecane were used as the liquid.

(C) Adhesion of oil-based pen: Using an oil-based pen (magic ink: No. 500 for fine writing), draw a 1 cm long straight line on the surface of the base material, and determine the stickiness or conspicuousness. Visual determination was made. The criteria are shown below. ：: The oily pen is repelled into a sphere. ×: The oily pen does not repel and can be written.

(D) Wipeability of oily pen: Cellulose nonwoven fabric [Bencott M]
-3: manufactured by Asahi Kasei Corporation], and the ease of removal was visually determined. The criteria are shown below. ：: The oil pen can be completely wiped off. Δ: Wipe marks of oily pen remain. ×: The oily pen cannot be wiped off.

(E) Fingerprint adhesion: A finger was pressed on the surface of the base material for several seconds to attach a fingerprint, and the degree of stickiness or conspicuousness was visually determined. The criteria are shown below. ：: Fingerprint adhesion is small, and the attached fingerprint is inconspicuous. X: Adhesion of a fingerprint can be recognized.

(F) Wiping ability of fingerprints: Fingerprints adhering to the substrate surface were wiped off with a cellulose nonwoven fabric (Bencott M-3: manufactured by Asahi Kasei Corporation), and the ease of removal was visually determined. The criteria are shown below. ：: The fingerprint can be completely wiped off. Δ: Fingerprint wiping remains. ×: The trace of wiping of the fingerprint spread and could not be wiped off.

(G) Abrasion resistance: The substrate surface is made of a cellulose nonwoven fabric (Bencott M-3: manufactured by Asahi Kasei Corporation) and has a load of 5
After rubbing 100 times with 00 gf, the above various physical properties were evaluated.

[0041]

[Table 1]

From Table 1, it can be seen that the spectacle lens with an antireflection film of Example 1 in which an antifouling layer was formed by the method of the present invention was a comparative example 1.
Compared to the spectacle lens with anti-reflective coating, the fingerprint,
It can be seen that dirt such as an oil pen is prevented from adhering, and that it has excellent antifouling property and durability that can be easily wiped off even if it adheres.

[0043]

According to the method of the present invention, various optical members (optical lenses, spectacle lenses, lenses of cameras and binoculars or other optical devices, beam splitters, prisms, mirrors,
The surface of window glass, anti-reflection coating, optical filter, etc.) is less susceptible to dirt such as fingerprints, sebum, sweat, cosmetics, etc. than those produced by conventional technology without impairing the optical performance of various optical members. Even with this, it is easy to wipe off, and an antifouling layer having excellent durability can be formed.
The method of the present invention does not require a diluting solvent as compared with the conventional wet coating method, and enables accurate control of the film thickness of the antifouling layer.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Jun Mitida 1-5-1, Taito, Taito-ku, Tokyo Letterpress Printing Co., Ltd. (72) Inventor Noritoshi Tomikawa 1-1-1, Taito, Taito-ku, Tokyo Letterpress Inside Printing Co., Ltd. (72) Inventor Jiro Watanabe 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd.

Claims (4)

[Claims] 1. A porous molded product is impregnated with an antifouling agent containing an organic silane compound represented by the following general formula (1) and heated in a vacuum to evaporate the antifouling agent. A film on a substrate to be treated by heating, humidifying, irradiating with ultraviolet rays, or irradiating with an electron beam, if necessary. Embedded image (Where R _f is a linear or branched perfluoroalkyl group having 1 to 16 carbon atoms, n is an integer of 1 to 50, and m is 0 to 0)
Integer of 3, 1 is an integer of 0 to 3, s is an integer of 0 to 6, provided that 6 ≧ m + 1> 0, and R represents a hydrolyzable group. ) 2. The method according to claim 1, wherein the porous molded product is made of SiO ₂ , TiO.
₂ , ZrO ₂ , MgO, Al ₂ O ₃ , CaSO ₄ , C
2. The method for forming an antifouling layer according to claim 1, comprising u, Fe, Al, stainless steel, carbon or the like, or a mixture of two or more thereof. 3. The heating method for evaporating the antifouling agent in the porous molded product is at least one heating method selected from a resistance heating method, an EB heating method, and a light heating method. 3. The method for forming an antifouling layer according to claim 1 or 2. 4. The substrate to be processed is an optical lens, an eyeglass lens, a camera or binoculars, or a lens of another optical device,
The method for forming an antifouling layer according to any one of claims 1 to 3, wherein the method is an optical member such as a beam splitter, a prism, a mirror, a window glass, an antireflection film, and an optical filter.