JP2000290412A - Molded product having hydrophilic thin film layer and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject molded product capable of recovering once deteriorated antifogging performances and exhibiting excellent antifogging performances for a long period by forming a hydrophilic thin film layer having the antifogging performances on a substrate and then irradiating the resultant layer with ultraviolet rays at a short wavelength. SOLUTION: A hydrophilic thin film layer having antifogging performances is formed on a substrate and the resultant layer is then irradiated with ultraviolet rays at a short wavelength of <=300 nm to thereby produce a molded product having the antifogging performances. The antifogging performances of the hydrophilic thin film layer irradiated with the ultraviolet rays are preferably deteriorated. The hydrophilic thin film layer is preferably formed by using a sputtering method comprising a step for sticking metal atoms onto the substrate and a step for oxidizing the metal sticking thereto, forming an oxide and forming the hydrophilic thin film layer. Furthermore, an ultraviolet absorbing layer is preferably provided between the hydrophilic thin film layer and the substrate in order to avoid the discoloration, etc., of the substrate with the ultraviolet rays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article provided with a hydrophilic thin film having anti-fog performance and a method for producing the same. Particularly, the present invention is characterized in that the anti-fog performance is improved or restored by irradiating the hydrophilic thin film layer with ultraviolet rays having a specific wavelength.

[0002]

2. Description of the Related Art Fogging of optical equipment and spectacle lenses using optical components such as mirrors, lenses and prisms, windows of buildings, windows and mirrors of automobiles, mirrors installed in bathrooms and wash basins is a daily occurrence. This phenomenon is frequently seen. Fogging occurs when the surface temperature of the substrate falls below the dew point, moisture in the atmosphere becomes fine water droplets and adheres to the surface, and the water droplets scatter light. And since fogging is a phenomenon that occurs everywhere, many attempts have been made to prevent this.

[0003] Attempts to prevent such fogging include: 1) a method of preventing the adhesion of water by making the surface of the substrate water repellent, and 2) making the surface of the substrate hydrophilic so that the entire surface of the substrate is easily wetted with water droplets. The method can be roughly classified into two methods for suppressing the occurrence of the image. However, in the method of making the surface of the base material water-repellent in the above 1), an excellent technique for completely preventing the adhesion of water has not been realized, and generally spherical fine water droplets are formed on the water-repellent surface. It often adhered and fogged rather easily.

Until now, the method of making the surface of a substrate hydrophilic is described in 2) above, although the antifogging effect has been recognized incompletely. Among them, the simplest method is to apply a surfactant to the surface of a base material to impart hydrophilicity, and this method has already been put into practical use as an anti-fog spray. Also,
In addition to these methods, there is a method of removing fogging by heating, and this method has been put to practical use in a rear window of an automobile or the like.

As a technique for maintaining the antifogging effect, a method of forming a film of a hydrophilic polymer on the surface of a substrate has also been used. Further, as an antifogging thin film having excellent scratch resistance, an antifogging thin film made of an inorganic oxide such as silicon oxide is known.

[0006]

However, in the method of 2) above, in which the surface of the base material having an antifogging effect is observed, it is difficult to uniformly apply the surfactant to the surface of the base material. There has been a problem of deteriorating the optical characteristics of the material surface.
Furthermore, the applied surfactant is easy to remove, and there is an inconvenience that the effect is not maintained unless it is repeatedly applied each time. Further, in this method, there is also a problem that the surface hardness of the formed film is insufficient and the scratch resistance is low.

Furthermore, the above-mentioned method of removing fogging by heating requires a power supply for heating, and has a problem that the applicable range is limited. Furthermore, since this method requires a heating wire, there is a problem that it is difficult to apply the method to a windshield or an eyeglass lens of an automobile which requires complete transparency. What has been a problem in any conventional hydrophilic thin film layer having antifogging property is the persistence of the antifogging effect. There are already many anti-fogging articles that show excellent anti-fogging properties at the beginning, but the effect is that the effects are surely maintained over a long period of time, and unfortunately there are almost no products that can be used for a long time. It is.

[0008]

The present inventors have conducted intensive studies on the persistence of the anti-fog effect, which is a problem common to the conventional hydrophilic thin film layers, and as a result, the ultraviolet light having a wavelength of 300 nm or less has been obtained. It was found that irradiation affected the anti-fog performance. Then, it has been found that the once-reduced anti-fogging performance is recovered by irradiation with ultraviolet rays having the above-mentioned wavelength.

[0009] However, the irradiation of ultraviolet rays sometimes causes deterioration of the base material. In particular, when the substrate is plastic, there is a case where the substrate is yellowed by irradiation with ultraviolet rays having a wavelength of 300 nm or less. The present inventors have further studied means for restoring antifogging performance while preventing discoloration of the substrate due to irradiation with ultraviolet rays. As a result, they found that it is effective to provide an ultraviolet absorbing layer between the hydrophilic thin film layer and the substrate.

As described above, according to the present invention, even if the anti-fogging property is once reduced, the original anti-fogging property can be restored again by a simple treatment, and the excellent anti-fogging performance can be obtained over a long period of time. It is an object of the present invention to provide an anti-fogging thin film that can obtain the following. Accordingly, the present invention firstly provides a method for forming a hydrophilic thin film layer having antifogging performance on a substrate, and irradiating the hydrophilic thin film layer with ultraviolet light having a short wavelength of 300 nm or less. A method for producing a molded article having fogging performance (Claim 1) "is provided.
Secondly, in the method for producing a molded article having anti-fogging performance according to claim 1, wherein the ultraviolet ray is applied to the hydrophilic thin film layer whose anti-fogging performance has deteriorated. Thirdly, there is provided a method for producing a molded article according to claim 1 or 2, wherein the hydrophilic thin film layer is formed by a sputtering method. provide. Fourth, "the sputtering method is:
The method according to claim 3, further comprising: attaching a metal atom on a base material; and oxidizing the metal atom to form an oxide to form a hydrophilic thin film layer. )"I will provide a. Fifth, a “substrate and three on the substrate”
A molded article (Claim 5) having a hydrophilic thin film layer having anti-fog performance irradiated with ultraviolet light having a wavelength of 00 nm or less is provided. Sixthly, there is provided "a molded article according to claim 5, wherein the article has an ultraviolet absorbing layer between the base material and the hydrophilic thin film layer."

[0011]

In the present invention, the antifogging performance can be maintained or restored by irradiating ultraviolet rays having a wavelength of 300 nm or less from above the hydrophilic thin film layer. Especially 2
Irradiation with ultraviolet light having a wavelength of 00 nm or less remarkably recovers and improves the antifogging performance. In the present invention, it is effective to irradiate ultraviolet rays containing light of the above-mentioned wavelength, but ultraviolet rays containing light other than the above-mentioned wavelength may be used.

A light source for generating ultraviolet rays having a wavelength according to the present invention is not particularly limited, but a low-pressure mercury lamp is preferable. In addition, a xenon lamp, a metal halide lamp, or the like can be used as a light source for irradiating light of 300 nm or less, and an excimer laser, an excimer lamp, or the like can be used if the irradiation conditions are controlled. The effect of maintaining and recovering the anti-fog performance depends on the wavelength of the ultraviolet light to be irradiated, but does not depend so strongly on the irradiation time. However, when practical use is considered, it is natural that the shorter the ultraviolet irradiation time as the means for maintaining and recovering the anti-fog performance, the higher the productivity and the more advantageous. Therefore, it is preferable to keep the irradiation time of the ultraviolet light within several seconds to 10 minutes.

When the hydrophilic thin film layer of the present invention is irradiated with ultraviolet rays, the contact angle of water on the surface of the hydrophilic thin film layer decreases. Normal,
In order to obtain an excellent anti-fog effect, the contact angle of water is desirably 10 degrees or less. Generally, the contact angle immediately after the formation of the hydrophilic thin film layer is 10 degrees or less, and the anti-fogging property of the thin film which initially had excellent anti-fog performance gradually decreases over a long period of use. However, the hydrophilic thin film layer of the present invention can maintain and recover the antifogging performance by irradiating an ultraviolet ray having a specific wavelength without any decrease in other characteristics. When applied to a surface with reduced anti-fogging performance, the contact angle of water shows a value of 20 degrees or more, but the contact angle is again reduced to 10 degrees or less by ultraviolet irradiation, and the anti-fogging performance is restored.

Irradiation with ultraviolet light having a specific wavelength is sufficient when the anti-fogging effect of the hydrophilic thin film layer is reduced. (Immediately before use)), and in this case, a molded article having more antifogging performance may be produced.
The details of the mechanism by which the contact angle of water is reduced by UV irradiation and the anti-fog performance is restored are unknown, but the organic matter in which ozone generated by UV irradiation of a specific wavelength adheres to the surface of the hydrophilic thin film layer is unknown. It is presumed that this is to disassemble and remove. According to the elemental analysis of the surface of the hydrophilic thin film layer by ESCA, C element is present on the surface where the anti-fogging performance is deteriorated, and the C element is present on the surface of the hydrophilic thin film layer where the anti-fogging performance is restored by the irradiation of ultraviolet rays. Was not confirmed. Therefore, the carbon element hardly exists on the surface of the hydrophilic thin film layer irradiated with ultraviolet rays according to the present invention.

There is no particular limitation on the material constituting the hydrophilic thin film layer according to the present invention.
It was revealed that the effect of maintaining and recovering the anti-fogging property by ultraviolet irradiation was particularly remarkable. As the silicon oxide, a silicon oxide represented by the general formula SiO _2-x (where 0 ≦ x <2) can be used, and among them, silicon dioxide is preferably used.

As a method for forming the hydrophilic thin film layer using silicon oxide, a generally known method such as a sputtering method, a vacuum evaporation method, a sol-gel method, and the like can be used. Among the sputtering methods, a method in which a metal atom is first attached to a base material, and then the metal atom is oxidized to form an oxide is preferable. The hydrophilic thin film layer obtained by such a method often shows hydrophilicity only by being formed, but for the purpose of imparting more excellent hydrophilicity, immersion in an alkaline aqueous solution or plasma treatment is performed. Is also good.

It has also been found that, when the hydrophilic thin film layer formed by the sputtering method is irradiated with ultraviolet rays, a more excellent anti-fogging property can be maintained and a recovery effect can be obtained.
Although the reason for this has not been clarified, the film formed by sputtering is likely to have a columnar structure, and is presumed to have some relationship with this structure. As described above, the hydrophilic thin film layer of the present invention is characterized by maintaining and recovering its anti-fog performance by irradiation with ultraviolet rays having a wavelength of 300 nm or less, and maintaining excellent performance over a long period of time. The effect becomes more remarkable when the ultraviolet rays are irradiated.

However, it is also important that other properties, such as transparency of the base material, are not lost by irradiation with ultraviolet rays. Therefore, it is more preferable to provide an ultraviolet absorbing layer between the hydrophilic thin film layer and the substrate. A more preferred structure of the molded article having the hydrophilic thin film layer of the present invention is one in which an ultraviolet absorbing layer is formed on a substrate on which the hydrophilic thin film layer is formed, and further provided with the hydrophilic thin film layer thereon. . Ultraviolet rays irradiated for maintaining and recovering the antifogging performance are partially absorbed by the hydrophilic thin film layer, and the remainder is transmitted to reach the substrate. However, according to the above configuration, the transmitted ultraviolet light is absorbed by the ultraviolet absorbing layer formed between the base material and the hydrophilic thin film layer, so that the ultraviolet light does not reach the base material. The ultraviolet absorbing layer needs to absorb substantially all of the ultraviolet light that causes discoloration of the substrate.

Therefore, with the above structure, it is possible to repeatedly recover the anti-fogging performance while avoiding discoloration of the base material due to the irradiation of ultraviolet rays. A hydrophilic thin film layer in which discoloration of the material does not occur can be obtained. There is no particular limitation on the substances constituting the ultraviolet absorbing layer, and a group of substances generally known as ultraviolet absorbing agents can be widely used.

Examples of these UV absorbers include 2, 4
-Dihydroxybenzophenone, 2-hydroxy-4-
Methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone Benzophenones such as 2-hydroxy-4-allyloxybenzophenone;
(2'-hydroxy-5'-methylphenyl) -benzotriazole, 2- (2'-hydroxy-3'-5'-
Benzotriazoles such as di-t-amylphenyl) -benzotriazole, ethyl-2-cyano-3,3′-
Examples thereof include diphenyl acrylates such as diphenyl acrylate and 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate; inorganic oxides such as zinc oxide, titanium oxide and cerium oxide; and mixtures thereof.

Since it is difficult to form a transparent thin film using these ultraviolet absorbers alone, it is preferable to use them in a state of being dissolved or dispersed in a matrix component. As the matrix component, any substance can be used as long as it is optically transparent and dissolves or disperses the ultraviolet absorber well. For example, polyvinyl acetal, polyvinyl alcohol, urethane (meth)
Inorganic oxide layer formed by so-called sol-gel method by condensation reaction of acrylate, epoxy (meth) acrylate, polyvinylpyrrolidone, polyaddition product of polyene compound and polyfunctional thiol compound, or hydrolysis product of metal alkoxide And the like. Furthermore, it is also possible to use an organic silicon compound such as epoxysilane, and in this case, it is also possible to improve the scratch resistance.

The method for forming the ultraviolet absorbing layer of the present invention is not particularly limited, and a dry method such as a sputtering method or a vacuum evaporation method, or a wet method such as spin coating or dip coating can be used. Generally, a method is used in which an ultraviolet absorbent is dissolved or dispersed in a matrix component, applied to a substrate by a wet method, and then dried. The substrate on which the hydrophilic thin film layer of the present invention can be formed is not particularly limited, and can be applied to substrates made of any material such as glass and transparent plastic as long as anti-fogging properties are required.

The thickness of the hydrophilic thin film layer is 0.001 to 10
0 μm is preferable, and the thickness of the ultraviolet absorbing layer is 0.01 to
10 μm is preferred. The hydrophilic thin film layer can be applied to a spectacle lens. When used for spectacle lenses, a hard coat film can be formed on a substrate.

The hard coat film is preferably an organosilicon compound represented by the following general formula (I) or a hydrolyzate thereof. General formula (I): R ¹ _a R ² _b Si (OR ³ ) _{4- (a + b)} (wherein, R ¹ is an organic group having a functional group or an organic group having an unsaturated double bond) R ² is a hydrocarbon group or a halogenated hydrocarbon group, R ³ is an alkyl group, an alkoxyalkyl group or an acyl group, a and b are each 0 or 1, and a + b is 1 Or 2. Also, R ¹ has 1 to 14 carbon atoms, and R ² has 1 to 1 carbon atoms.
6, R ³ preferably has 1 to 4 carbon atoms).

Among the compounds of the general formula (I), those in which R ¹ has an epoxy group as a functional group are also called epoxysilanes. Specific examples of epoxysilane include, for example, γ-glycidoxypropyltrimethoxysilane, γ
-Glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxyethoxysilane, γ-glycidoxypropyltriacetoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane , Β- (3,4-
Epoxycyclohexyl) ethyltriethoxysilane and the like.

Further, among the compounds of the general formula (I), R ¹
Examples of compounds other than those having an epoxy group as a functional group (including those having a = 0) include, for example, the following. Methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, γ-methacryloxypropyltrimethoxysilane, aminomethyltrimethoxysilane, 3
-Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, 3,3,3-trifluoropropyl Various trialkoxysilanes such as trimethoxysilane, trisiloxysilane or trialkoxyalkoxysilane compounds.

When these compositions are used, the hardness is improved,
It is also possible to add inorganic fine particles for preventing interference fringes and imparting an antistatic effect. Examples of the inorganic fine particles include zinc oxide, silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, beryllium oxide, antimony oxide, tungsten oxide, cerium oxide, iron oxide, and composite fine particles of tin oxide and tungsten oxide. Fine particles of inorganic fine particles can be used.

These fine particles can be used not only singly, but also, if necessary, in the form of a mixture of two or more kinds, a solid solution or a complex, or a state in which these are present together. As the mixture in the present invention,
A solid solution refers to a state in which a plurality of different substances exist while maintaining the structure of each substance, and a solid solution is a substance in which different substances form a new chemical bond with each other. Is called.

In particular, titanium oxide, antimony oxide,
Tungsten oxide, cerium oxide, zirconium oxide,
When tin oxide is used, the refractive index of the composition can be increased, and when a substrate having a high refractive index is used, generation of interference fringes can be suppressed. Fine particles having a particle diameter of 1 to 200 nm are used.
The one with 0 nm is preferred. If it is smaller than this, it is difficult to produce, the stability of the fine particles themselves is poor, and the effect of addition is small. If it is larger than this, the stability of the coating composition, the transparency and the smoothness of the coating film, etc. will be reduced.

If an antireflection film made of an inorganic oxide formed by a vacuum evaporation method is formed on the above-mentioned hard coat film or substrate, a lens having excellent antireflection effect and excellent appearance can be produced. it can. Materials used for the antireflection film include silicon oxide, titanium oxide, zirconium oxide, and aluminum oxide. Furthermore, if a primer layer is formed between the lens substrate and the hard coat film to improve the adhesion and the impact resistance, a plastic lens having more excellent impact resistance can be manufactured. As a material of the primer layer, a polyurethane resin, an epoxy resin, a polyacetal resin, or the like is preferable. It is also possible to form a primer layer made of crosslinked polyvinyl acetal.

The thickness of the primer layer is 0.1 to 5 μm, preferably 0.2 to 3 μm after the thermosetting. If the thickness of the primer layer is less than 0.1 μm, the impact resistance is not sufficiently improved, and if it is more than 5 μm, there is no problem in terms of the impact resistance, but the heat resistance and surface accuracy are reduced. Further, the primer solution may contain inorganic fine particles as added to the hard coat film. As these inorganic fine particles, commercially available fine particles dispersed in water or an organic solvent can be used as they are.

The average particle diameter of the inorganic fine particles or the composite of these inorganic oxides is 1 to 300 nm, preferably 1 to 300 nm.
５０50 nm is preferred. If the average particle diameter exceeds 300 nm, fogging of the lens occurs due to light scattering. An ultraviolet absorber may be added to such a hard coat film, a primer layer, and an antireflection film, and this may be used also as the ultraviolet absorption layer.

[0033]

[Embodiment 1] 1. First Embodiment Formation of UV Absorbing Layer Coating Solution After dissolving 630 parts by weight of n-butanol in 700 parts by weight of polyvinyl butyral (manufactured by Wako Pure Chemical Industries, Ltd.), 400 parts by weight of methanol, 100 parts by weight of water, and tetramethoxysilane as a crosslinking agent 4.2 parts by weight were added and stirred until uniform. After adding 1.2 parts by weight of p-toluenesulfonic acid as a curing catalyst, a cerium oxide-based ultraviolet absorber (Neidral W-100, manufactured by Taki Chemical Co., Ltd.) 7
After adding 0 parts by weight and stirring for 1 hour, the mixture was filtered with a 3 μm membrane filter. 2. Formation of Ultraviolet Absorbing Layer The coating liquid prepared in 1 above was applied to an acrylic substrate by a dipping method, and then heated and cured at 100 ° C. for 20 minutes to form an ultraviolet absorbing layer. The thickness of the ultraviolet absorbing layer was 2 μm. 3. Formation of hydrophilic thin film layer A thin film made of silicon oxide was formed as a hydrophilic thin film layer by RF sputtering on the ultraviolet absorbing layer formed in 2). That is, silicon dioxide was used as the target, RF power was 800 W, and Ar gas flow rate was 100 scc.
m, a set pressure of 0.5 Pa, and a deposition time of 10 minutes, a silicon oxide layer having a thickness of 1000 ° was formed. 4. Evaluation of hydrophilicity and anti-fogging performance The contact angle of water of the hydrophilic thin film layer formed in the above 3 was measured on the next day of film formation, and was about 5 degrees, indicating that this film has excellent hydrophilicity. It was revealed.

The antifogging performance was evaluated as follows. That is, after the glass substrate on which the hydrophilic thin film layer was formed in the steps up to 3 was stored in a 5 ° C. atmosphere (in a refrigerator) for 1 hour,
The state of instantaneous transfer to an atmosphere of 85 ° C. and 85% RH was visually observed. As a result, it was revealed that the glass substrate provided with the hydrophilic thin film layer of this example had excellent anti-fog performance without any fogging.

As described above, the acrylic substrate of this example evaluated for hydrophilicity and anti-fog performance the day after film formation was stored indoors for one year. Then, in order to know the hydrophilicity one year later, the contact angle of water was measured by the same method as described above, and it was about 22 degrees. In addition, the antifogging performance after one year was evaluated by the same method as described above. As a result, it was found that fogging occurred immediately after transferring to 25 ° C. and 85% RH, and the antifogging performance was deteriorated.
5. Recovery of hydrophilicity and antifogging performance In order to restore the antifogging performance of the acrylic substrate of this example, in which deterioration of the antifogging performance after one year was recognized in 4 above, ultraviolet irradiation was performed as follows. That is, a low-pressure mercury lamp of 200 W is used, and the wavelength of irradiation light is mainly 185 nm and 254 nm. Irradiation was performed at a distance of 40 cm from the substrate for 5 minutes.

When the contact angle of water was measured immediately after the above treatment, it was about 3 degrees, which revealed that the hydrophilicity had been restored (see Table 1). When the antifogging property was evaluated by the same method as described above, no fogging was observed, and it became clear that the initial antifogging performance was restored. For comparison with Example 1, recovery of antifogging performance was attempted by the following method.

An example in which a high-pressure mercury lamp was used for the hydrophilic thin film layer to recover the anti-fog performance and ultraviolet rays having a wavelength of 300 nm or more (Table 1) was used. An example in which ultraviolet light having a wavelength of 200 nm or more was irradiated (2 in Table 1),
Example 1 irradiated with ultraviolet light including ultraviolet light of 0 nm or less
With respect to (3) in Table 1, the change over time in the contact angle is shown in Table 1.

[0038]

[Table 1]

As can be seen, in the example using the high-pressure mercury lamp, the anti-fogging performance is recovered, but the effect of recovering the contact angle is small when comparing before and immediately after the irradiation of ultraviolet rays. This is because a high-pressure mercury lamp was used.
The effect was small due to irradiation with light containing ultraviolet rays having a wavelength exceeding 0 nm as a main component. In the case of irradiation with UV light from a low-pressure mercury lamp through a filter, the contact angle immediately after irradiation is from 22 degrees to 15 degrees, indicating that the anti-fog performance is more improved than in the case of irradiation with UV light from a high-pressure mercury lamp. I understand. This is because UV light having a wavelength of 300 nm or less is mainly irradiated because a low-pressure mercury lamp is used, but the effect is better than when a high-pressure mercury lamp is used because UV light having a wavelength of less than 200 nm is filtered and not irradiated. However, the results were inferior to those of item 3 in Table 1 (not filtered using a low-pressure mercury lamp).

In the case of the first embodiment, the contact angle of 6 degrees is maintained even 14 days after the irradiation with the ultraviolet rays.
It can be seen that there is an excellent recovery and maintenance effect of the anti-fog performance. Example 2 In this example, a hydrophilic thin film layer was formed using the sputtering apparatus shown in FIGS. FIG.
FIG. 2 is a schematic top view of an apparatus according to the present embodiment, and FIG.
1 is a schematic front view of an apparatus according to the present embodiment.

In this sputtering apparatus, first, a single metal material as a raw material of a thin film is deposited on a base material, and then the deposited metal material reacts with a reaction gas. To form a thin film. In this embodiment, since a thin film made of a single silicon oxide-based material is formed, only the film forming chamber 12 shown in FIG. 1 is used as the film forming chamber. If you want to increase the deposition rate,
It is also possible to set the target 19 in the film forming chamber 20 of FIG. It is also possible to use the region 22 in FIG. 1 as a reaction chamber. Reference numeral 18 denotes a partition that partitions each room.

In this embodiment, a glass substrate was used. Polycrystalline Si was used for the metal targets 13 and 19, and a hydrophilic thin film layer mainly composed of a silicon oxide-based material was formed directly on a glass substrate. The pressure in the vacuum chamber is 3.
It was set at 2 × 10 ⁻³ Torr, argon gas was used as a sputtering gas, and the flow rate was set at 390 sccm. The introduced argon gas is ionized by glow discharge, and the polycrystalline S
The light was incident on the i target 13. The sputtering power was set at 3.75 kW.

The Si atoms sputtered by the incidence of argon ions are transferred to the substrate holder 14 rotating at high speed.
Is deposited on the surface of the glass substrate 15 held at a thickness of about several atomic layers. In this example, the thickness of the layer on which the Si atoms were deposited when the film passed through the film forming chamber 12 once was 10 ° or less. The temperature of the substrate at this time is about room temperature.
The rotation speed of the substrate holder 14 was set at 100 rpm.

The substrate 15 on which Si atoms are deposited with a thickness of about several atoms in the film forming chamber 12 by the above-described process is moved to the reaction chamber 17 together with the substrate holder 14 rotating at a high speed. Oxygen, which is a reaction gas, is introduced into the reaction chamber 17 from the inlet 16, and the reaction gas is turned into a plasma state by high frequency discharge. The plasma power at this time was 1.2 kW. Si
The substrate with the atoms deposited is exposed to oxygen plasma as it passes through the reaction chamber 17. Here, the oxygen plasma reacts with the Si atoms deposited on the surface of the substrate 15 to form a silicon oxide-based thin film. The thickness of the silicon oxide-based thin film was substantially the same as the film formed by the Si atoms previously deposited on the substrate.

The substrate 15 on which the silicon oxide-based thin film is formed as described above exits from the reaction chamber 17 together with the substrate holder 14 rotating at a high speed, and moves to the film formation chamber 12 again. By moving the substrate from the film formation chamber to the reaction chamber as described above, a film of about several atoms can be formed, and by repeating this plural times, a hydrophilic thin film having a desired film thickness can be formed. It is possible.

The static contact angle with water of the silicon oxide-based hydrophilic thin film obtained in this example was measured. For the measurement, a contact angle measuring device manufactured by Kyowa Interface Science Co., Ltd. was used. as a result,
The static contact angle of water was 3 degrees, which proved that it had good hydrophilicity. In order to evaluate the anti-fog performance of the hydrophilic thin film layer, the sample was placed in a refrigerator set at 5 ° C.
I kept it for a while and breathed immediately after taking it out.
No fogging was observed, and excellent antifogging performance was confirmed.

Further, the present inventors measured the static contact angle one year after forming the hydrophilic thin film on the substrate by the same measuring method as described above. As a result, the measurement result one year after the film formation was 2
At two degrees, the hydrophilicity was shown to be degraded. When the antifogging performance was tested in the same manner as immediately after the film formation, it was confirmed that fogging occurred and the antifogging performance was deteriorated. The thin film was irradiated with ultraviolet rays to try to restore hydrophilicity. That is, light from a 200 W low-pressure mercury lamp was applied at a distance of 40 cm for 5 minutes. Since the low-pressure mercury lamp is used in this embodiment as described above, the wavelength of the irradiation light is 185 nm and 254 nm.
nm light (without cutting light of wavelength below 200 nm)
Is a main component. When the static contact angle of water of the sample immediately after the irradiation was measured, it was 3 degrees, and the hydrophilicity was restored. Two weeks after the irradiation, the contact angle was measured in the same manner. As a result, the excellent hydrophilicity was maintained at 6 degrees.

In addition, the antifogging performance was examined in the same manner. As a result, no fogging was observed immediately after the irradiation and 14 days after the irradiation, indicating that the antifogging performance was restored by the irradiation of the ultraviolet rays, and it was maintained for a long time. . Example 3 In this example, as in Example 1, a hydrophilic thin film layer was formed using the sputtering apparatus shown in FIG. The same substrate as in Example 2 was used. In this embodiment, a hydrophilic thin film layer in which a low refractive index layer and a high refractive index layer are laminated is formed. Therefore, metal target 1
3 is provided with polycrystalline Ta, and 19 is provided with polycrystalline Si, and a hydrophilic thin film layer comprising a silicon oxide-based thin film and a tantalum oxide thin film is formed directly on a plastic lens substrate.

(1) Formation of Tantalum Oxide Thin Film The pressure in the vacuum chamber was set to 3.0 × 10 ⁻³ Torr,
Argon gas was used as the sputtering gas, and the flow rate was set to 350 sccm.
2 was introduced. The introduced argon gas was ionized by glow discharge and made incident on the polycrystalline Ta target 13. The sputtering power was set to 3.00 kW. The rotation speed of the substrate holder 14 was set to 100 rpm.

The Ta atoms sputtered by the incidence of argon ions are transferred to the substrate holder 14 rotating at high speed.
Is deposited on the surface of the glass substrate 15 held at a thickness of about several atomic layers. The temperature of the substrate at this time is about room temperature. The substrate 15 on which Ta atoms are deposited with a film thickness of about several atoms in the film forming chamber 12 by the above-described process moves to the reaction chamber 17 together with the rotating substrate holder 14. Reaction chamber 17
, Oxygen as a reaction gas is introduced from the reaction gas inlet 16, and the reaction gas is turned into a plasma state by high-frequency discharge. At this time, the flow rate of the oxygen gas was 70 sccm, and the plasma power was 2.0 kW.

The substrate on which the Ta atoms are deposited is placed in the reaction chamber 17.
When exposed to oxygen plasma. Here, the oxygen plasma reacts with the Ta atoms deposited on the surface of the base material 15 to form a tantalum oxide thin film. The thickness of the tantalum oxide thin film was substantially the same as the thickness of the Ta atom previously deposited on the substrate. Also in this embodiment, a tantalum oxide thin film having a desired thickness can be formed by repeating the step of depositing from the Ta target 13 and the step of forming the tantalum oxide thin film in the reaction chamber 17.

(2) Formation of Silicon Oxide Thin Film Substrate 1 on which tantalum oxide thin film was formed by the above-described process
5 is a reaction chamber 1 together with a substrate holder 14 rotating at a high speed.
7 and moves to the film forming chamber 20. A polycrystalline Si target 19 is installed in the film forming chamber 20. The pressure in the vacuum chamber is 3.0 × 10 ⁻³ Torr. Argon gas was used as the sputtering gas, and the flow rate was 250 s.
It was set to ccm and introduced into the film forming chamber 20 from the inlet 21. The introduced argon gas was ionized by glow discharge and made incident on the polycrystalline Si target 19. The sputtering power was set to 3.00 kW. Substrate holder 1
The rotation speed of No. 4 was set to 100 rpm.

The Si atoms sputtered by the incidence of argon ions are transferred to the substrate holder 14 rotating at high speed.
Is deposited on the surface of the glass substrate 15 held at a thickness of about several atomic layers. The temperature of the substrate at this time is about room temperature. The substrate 15 on which Si atoms are deposited with a film thickness of about several atoms in the film forming chamber 20 by the above-described process is moved again to the reaction chamber 17 together with the rotating substrate holder 14. Oxygen, which is a reaction gas, is introduced into the reaction chamber 17 from the inlet 16,
The reaction gas is turned into a plasma state by the high frequency discharge. At this time, the flow rate of the oxygen gas was 80 sccm, and the plasma power was 2.0 kW.

The substrate having Si atoms deposited on the tantalum oxide thin film is exposed to oxygen plasma when passing through the reaction chamber 17. Here, oxygen plasma reacted with Si atoms deposited on the tantalum oxide thin film, and a silicon oxide-based thin film was formed. The thickness of the silicon oxide-based thin film was substantially the same as the thickness of the film formed by the Si atoms previously deposited on the tantalum oxide thin film. Also in this case, a layer made of a silicon oxide-based material having a desired film thickness can be formed by repeating the step of deposition from the Si target 19 and the step of forming a layer made of the silicon oxide-based material in the reaction chamber 17.

In this embodiment, a silicon oxide-based thin film is formed after the tantalum oxide thin film is formed as described above, and the argon gas ionized in the film forming chamber 12 is again formed on the silicon oxide-based thin film on the substrate 15. Tantalum atoms are deposited by sputtering. This is moved to the reaction chamber 17 to form a tantalum oxide layer. Further, a silicon oxide-based thin film was formed on the tantalum oxide layer under the same conditions as when the silicon oxide-based thin film was formed.
Therefore, the anti-fogging thin film in this embodiment is composed of a tantalum oxide layer, a silicon oxide layer, a tantalum oxide layer, and a silicon oxide layer from the substrate side. The thickness of each layer is 0.
06λ, 0.05λ, 0.5λ, 0.25λ (λ = 52
0 nm).

The static contact angle with water of the silicon oxide-based hydrophilic thin film obtained in this example was measured. For the measurement, a contact angle measuring device manufactured by Kyowa Interface Science Co., Ltd. was used. as a result,
The static contact angle of water was 3 degrees, which proved that it had good hydrophilicity. In addition, in order to evaluate the anti-fogging performance of the hydrophilic thin film layer, the sample was stored in a refrigerator set at 5 ° C. for 1 hour, and immediately after being taken out, breathing was performed. Antifogging performance was confirmed.

Further, one year after forming the hydrophilic thin film layer on the substrate, the present inventors measured the static contact angle by the same measuring method as described above. As a result, the measurement result one year after the film formation was 22 degrees, indicating that the hydrophilicity was deteriorated. When the antifogging performance was tested in the same manner as immediately after the film formation, it was confirmed that fogging occurred and the antifogging performance was deteriorated. The thin film was irradiated with ultraviolet rays to try to restore hydrophilicity. The irradiation conditions of the ultraviolet rays were the same as in Examples 1 and 2. That is, 20
Light from a 0 W low-pressure mercury lamp was applied at a distance of 40 cm for 5 minutes.

When the static contact angle of water of the sample immediately after irradiation was measured, it was 3 degrees, and the hydrophilicity was restored. Two weeks after the irradiation, the contact angle was measured in the same manner. As a result, good hydrophilicity was maintained at 6 degrees. As a result of similarly examining the anti-fogging performance, no fogging was observed at all immediately after the irradiation and 14 days after the irradiation, indicating that the anti-fogging performance was restored by the irradiation of the ultraviolet rays, and it was maintained for a long time.

Example 4 A hydrophilic thin film layer was formed using the sputtering apparatus shown in FIG. 1 in the same manner as in Examples 2 and 3, and the same substrate was used. In this embodiment, two kinds of substances used for the target are prepared as in the embodiment 3, and each of them is alternately laminated. The laminate obtained in this embodiment has both anti-fogging property and anti-reflection property. To have properties. Therefore, in this embodiment, this laminate is referred to as a hydrophilic antireflection film.

In this embodiment, the uppermost layer in the laminate is formed of a silicon oxide-based thin film. The target 13 is made of polycrystalline Si as a low refractive index metal target, and the target 19 is made of polycrystalline Zr as a high refractive index metal target.
It was used. Argon gas used as a sputtering gas is introduced from introduction ports 11 and 21 into film formation chambers 12 and 20, respectively, and ionized. At this time, the flow rate of the argon gas was set to 390 sccm.

In this embodiment, first, a thin film made of zirconium oxide is formed on the substrate 15. First, ionized argon gas is generated in the film forming chamber 20 by glow discharge. The argon ions are made incident on the polycrystalline Zr target 19. The Zr atoms sputtered by the incidence of the argon ions are deposited on the glass substrate 15 held by the substrate holder 14. In this embodiment, the thickness of the film formed by the deposition is set to about several atoms. The temperature of the substrate at the time of deposition was about room temperature. The sputtering power of the Zr target 19 was 2.60 kW. In order to deposit only a few atomic layers of Zr atoms, a substrate holder 1 is used.
4 was rotated at 100 rpm. This rotation makes it possible to move the substrate 15 from the film forming chamber 20 to the reaction chamber 17, and the rotation speed is high, so that the thickness of the deposited film can be made extremely thin. .

Oxygen, which is a reaction gas, is introduced into the reaction chamber 17 through the inlet 16 and then turned into a plasma by high-frequency discharge. The plasma power at this time was 1.2 kW, the flow rate of oxygen gas was 120 sccm, and the pressure in the vacuum chamber was 3.2.
× 10 ⁻³ Torr. The substrate 15 on which Zr atoms are deposited with a thickness of about several atoms rotates together with the substrate holder 14 rotating at 100 rpm, exits the film forming chamber 20 and
7 and pass through the reaction chamber 17 at high speed. At this time, the zirconium oxide thin film is formed by exposure to oxygen plasma existing in the reaction chamber 17 and reaction of oxygen plasma with Zr atoms. The thickness of the zirconium oxide thin film was substantially the same as the thickness of the metal Zr before oxidation in a deposited state.

In this embodiment, a zirconium oxide thin film having a predetermined thickness can be formed on a glass substrate by repeating the formation of the zirconium oxide thin film.
Needless to say, if the number of formations of zirconium oxide is increased, a thick film can be obtained. Next, a thin film made of a silicon oxide-based thin film is formed on the zirconium oxide thin film formed on the substrate 15 by the above steps. First, the argon gas introduced into the film forming chamber 12 is turned into an argon gas ionized by glow discharge. Then, argon ions enter the polycrystalline Si target 13. Si atoms sputtered by the incidence of argon ions are deposited on a zirconium oxide thin film formed on the substrate 15.

The sputtering power of the Si target 13 at this time is 3.75 kW. Also, the substrate holder is rotating at 100 rpm to deposit only a few atomic layers. Oxygen as a reaction gas is supplied from the inlet 16 to the reaction chamber 17.
After being led to a plasma state by high-frequency discharge. At this time, the plasma power was 1.2 kW, the flow rate of oxygen gas was 120 sccm, and the pressure in the vacuum chamber was 3.2 ×
10 ⁻³ Torr. Substrate 15 with Si atoms deposited
Is passed through the reaction chamber 17, the Si atoms deposited on the substrate 15 are exposed to oxygen plasma,
The atoms and oxygen plasma react to form a silicon oxide-based thin film.

By such a process, a zirconium oxide thin film and a silicon oxide-based thin film could be alternately laminated on the substrate 15. The film configuration and film thickness of the hydrophilic anti-reflection film thus obtained are as follows: from the glass substrate side, the zirconium oxide thin film is about 130 °, the silicon oxide based thin film is about 180 °, the zirconium oxide thin film is about 1280 °, and the silicon oxide based thin film is The thin film was about 870 °.

The static contact angle with water of the silicon oxide-based hydrophilic thin film obtained in this example was measured. For the measurement, a contact angle measuring device manufactured by Kyowa Interface Science Co., Ltd. was used. as a result,
The static contact angle of water was 3 degrees, which proved that it had good hydrophilicity. Further, in order to evaluate the anti-fog performance of the hydrophilic thin film, the sample was stored in a refrigerator set at 5 ° C. for 1 hour, and immediately after being taken out, breathing was performed. Fogging performance was confirmed. Further, the present inventors, after forming a hydrophilic thin film layer on a substrate,
Years later, the static contact angle was measured by the same measuring method as described above.
As a result, the measurement result one year after the film formation was 22 degrees, indicating that the hydrophilicity was deteriorated. When the antifogging performance was tested in the same manner as immediately after the film formation, it was confirmed that fogging occurred and the antifogging performance was deteriorated. The thin film was irradiated with ultraviolet rays to try to restore hydrophilicity. Also in this embodiment, the first embodiment,
The irradiation was performed under the same ultraviolet irradiation conditions as those in the steps 2 and 3. That is, 20
Light from a 0 W low-pressure mercury lamp was applied at a distance of 40 cm for 5 minutes.

When the static contact angle of water of the sample immediately after the irradiation was measured, it was 3 degrees, and the hydrophilicity was restored. Two weeks after the irradiation, the contact angle was measured in the same manner. As a result, good hydrophilicity was maintained at 6 degrees. As a result of similarly examining the anti-fogging performance, no fogging was observed at all immediately after the irradiation and 14 days after the irradiation, indicating that the anti-fogging performance was restored by the irradiation of the ultraviolet rays, and it was maintained for a long time.

In this embodiment, the expression "silicon oxide-based substance" is used, but this is a general term for silicon monoxide and silicon dioxide. Therefore, the components of the silicon oxide-based thin film are in a state where silicon monoxide or silicon dioxide is present alone or in a mixture of both.

[0069]

As described above, according to the present invention, even if the anti-fogging performance is deteriorated by long-term use, the anti-fogging performance can be restored by irradiation of ultraviolet rays of a specific wavelength, and the anti-fogging can be used for a long time A hydrophilic thin film layer having performance can be provided. Further, if the ultraviolet ray is irradiated before the anti-fogging performance is deteriorated, the deterioration of the anti-fogging performance can be delayed, and a molded article having a hydrophilic thin film layer that can be used for a longer period can be obtained.

The hydrophilic thin film layer having anti-fogging performance of the present invention can be restored to anti-fogging performance any number of times because it is not deteriorated by irradiation with ultraviolet rays of a specific wavelength. Further, by providing an ultraviolet absorbing layer between the base material and the hydrophilic thin film layer, it is possible to prevent problems such as deterioration of the base material due to ultraviolet light irradiated for recovery of antifogging performance, and further excellent performance. A molded article having a hydrophilic thin film layer having anti-fog performance is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic top view of a sputtering apparatus according to the present embodiment.

FIG. 2 is a schematic front view of a sputtering apparatus according to the present embodiment.

[Explanation of symbols]

 11, 21 ... Sputtering gas introduction port 12, 20 ... Deposition chamber 13, 19 ... Target 14 ... Substrate holder 15 ... Substrate 16 ... Reactant gas inlet 17: Reaction chamber 18: Partition wall 22: Area that can be used as a reaction chamber

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // C09K 3/18 G02B 1/10 Z F term (Reference) 2K009 BB02 BB14 CC03 CC24 CC26 DD02 DD04 DD17 EE00 EE02 4F006 AA22 AB20 AB76 BA03 BA10 CA05 DA01 4F073 AA14 BA00 BB01 CA45 4G059 AA11 AC07 AC21 EA01 EA04 EA05 EB04 FA07 FA13 FA15 FA17 FA21 FA29 FB01 FB03 4H020 AA01 AB02

Claims (6)

[Claims] An antifogging property characterized by forming a hydrophilic thin film layer having antifogging performance on a substrate and irradiating the hydrophilic thin film layer with ultraviolet light having a short wavelength of 300 nm or less. A method for producing a molded article. 2. The method for producing a molded article having anti-fogging performance according to claim 1, wherein in the method for producing a molded article, the ultraviolet light is applied to a hydrophilic thin film layer having deteriorated anti-fog performance. Method. 3. The method according to claim 1, wherein the hydrophilic thin film layer is formed by a sputtering method. 4. The method according to claim 1, wherein the sputtering method includes a step of depositing a metal atom on a base material, and a step of oxidizing the metal atom to form an oxide to form a hydrophilic thin film layer. 3. The production method according to 3. 5. A molded article comprising: a substrate; and a hydrophilic thin film layer having antifogging performance irradiated with ultraviolet rays having a wavelength of 300 nm or less on the substrate. 6. The molded article according to claim 5, further comprising an ultraviolet absorbing layer between said base material and said hydrophilic thin film layer.