JPH02178601A - Optical glass - Google Patents

Abstract

PURPOSE:To obtain optical glass prevented from generation of weathering by covering a whole surface of glass with a covering film having a specified thickness and being constituted of a specified wt.% of SiO2 and specified wt.% of at least one kind selected from a group consisting of Al2O3, TiO2, ZrO2 and CeO2. CONSTITUTION:A covering film having 20-200nm thickness constituted of >=80wt.% SiO2 and 0-20wt.% at least one kind selected from Al2O3, TiO2, ZrO2 and CeO2 is covered on the whole surface of glass. For example, a dipping soln. is prepd. by mixing a monomer or polymer of tetraethoxy silane is a mixed solvent of alcohol or in benzene, etc., and admixing 2wt.%(based on the amt. of the tetraethoxy silane in the liquid mixture) tetraisopropoxy zirconium therewith. An opposed corner 2 of optical glass 1 as a material for a rectangular filter is put between a jig 3 and the glass is dipped in the dipping soln. The glass is then pulled up at 15cm/min velocity, dried, and calcined for 30min at 500 deg.C. Thus, the weather resistance and transmissivity of the glass are improved.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention is suitable for improving the weather resistance of glass.

(Prior art) It is said that there is almost no error in considering the chemical properties of glass as the chemical durability of glass from a practical standpoint. Classified.

If this kind of glass is exposed to the atmosphere for a long time,
So-called weathering on the surface
The transformation that is said to occur occurs. In particular, some optical glasses have poor weather resistance, and some are susceptible to surface deterioration that impairs their original purpose and function during long-term use. For example, in image carrier semiconductor devices applied to color V and TR cameras, a filter that absorbs infrared components is used, and glass based on phosphate components is generally used for this.

This phosphate-based glass has poor chemical durability, tends to cause weathering, and cannot function as a filter satisfactorily.

This weathering, also known as mortar tan, is a weathering phenomenon that occurs due to the reaction between glass components and atmospheric water adhering to the glass surface.

The solution to this weathering is: ←) Cover glass: Attach cover glasses to both sides of the filter to prevent the surface from being exposed to the air.

(b)S! 02 vapor deposition: S on the filter surface! 0
A protective layer is formed by coating the two films by vacuum evaporation. is taken.

The latter SiO2 vapor deposition method also uses a planetarium method based on mass production, in which case optical glass is attached to the surface of a rotating body placed in a vacuum atmosphere.
Evaporated matter is deposited from an evaporation source placed around the rotating body to form a protective layer. Therefore, a part of the optical glass is not deposited due to the locking component, and the same is true when depositing on - pieces of optical glass.

(Problems to be Solved by the Invention) Method A has drawbacks such as a decrease in visible wavelengths due to the use of a sealant and the volatilization of a solvent, which generates stains.

Also, S! The method described above in which Oz is coated by vacuum evaporation has the drawback that even if both the front and back surfaces are coated, weathering occurs from surrounding uncoated areas.

The present invention was made in consideration of such circumstances, and
By coating the glass with a protective layer containing the 5102 film and a special component, the objective is to block contact between the glass and the atmosphere, prevent weathering, and maintain the properties of optical glass stably for a long period of time.

L Configuration of the Invention] (Means for Solving the Problems) The present invention provides S! 0280% by weight or more and M1203
゜T! The present invention is characterized in that the entire surface of the glass is coated with a film having a thickness of 20 to 200 tnn and comprising at least one selected from the group consisting of ZrO2, ZrO2, and CeO2 in an amount of O to 20% by weight.

(for production) Table 1 below is submitted as the basis for numerical limitations.

(Left below) Table 1 M1203. TiO2, ZrO2゜Ce0z
S! When mixed with 02 and coated on optical glass, the transmittance after the above-mentioned high temperature and high humidity test showed a better value than in other cases, and when the content exceeds 20 wt%, the transmittance decreases. When the content exceeds 20 wt%, the transmittance decreases, which is not preferable for optical glass properties.

Therefore, in the present invention, S! 02 at 80wt% or more, 14
11203, TiO2, ZrO2, and Ce0z should be 20wt% or less, and if the thickness is less than 20nllll, a sufficient effect in improving chemical durability cannot be obtained;
If the thickness exceeds 0 nm, cracks will occur in the film, which is undesirable.

From this background, in the present invention, the components and content of the protective film, as well as its thickness, are limited as described above.

(Example) An example according to the present invention will be described with reference to FIGS. 1 to 5. That is, dipping (D
An example of coating optical glass with a protective film using the ippina method will be described. As the dipping liquid, a monomer or polymer of tetraethoxysilane is mixed with a mixed solvent such as alcohol, ethyl acetate, methyl acetate, or benzene.

A dip solution is prepared by mixing 2% by weight of tetra-iso-propoxy-zirconium with respect to the tetraethoxysilane in this mixed solution.

Next, as shown in FIG. 1, the opposing angles 2 of the optical glass 1, which will become a rectangular parallelepiped filter, are held between suitable jigs 3 and immersed in a dip liquid 4 filled in a suitable container (not shown). Next, it was pulled up at a rate of 15 cm/min, dried at 150°C for 10 minutes, and then fired at 500'C for 30 minutes. Incidentally, the Gaden treatment step is performed in the atmosphere.

As a result, S! contains ZrO2 and is transparent and has strong film strength.
The entire surface of the optical glass is coated with a 100 nm thick 02 protective film, improving its weather resistance.

Kokote, applicable M1202, TiO2゜ZrO2
, describes the alcorado of Ce0z.

That is, triethoxyaluminum, triamy propoxyaluminum and tri-n-butoxyaluminum T! for MhoS. For 02, tetraethoxytitanium, tetra-1-proboxytitanium and tetra-n-poxytitanium Z r For 02, tetraethoxyzirconium, tetra-1-propoxyzirconium and tetra-n-
For butoxyzirconium CeO2, there are triethoxycerium, tripropoxycerium, and tri-n-butoxycerium, and the dip liquid formed from each of them may be formed in the same manner as in the above embodiment.

In addition to optical glass used as a filter, such a protective film can also be applied to dosimeter glass, which is a functional glass such as phosphate glass as well as optical glass.

By the way, Figure 2 shows a curve obtained by plotting the film thickness (nm) on the vertical axis and the pulling speed (cm/min) on the horizontal axis, showing the relationship between the pulling speed and film thickness required for forming a protective film. Ta. As is clear from this figure, the amount of adhesion increases as the pulling speed increases, and at the above-mentioned pulling speed of 15 cm/min, a film thickness of about 70 to 80 nm can be obtained.

In addition, the spectral transmittance of glass coated with a protective film is 500n compared to glass without a protective film, that is, a filter glass substrate.
Figure 3 shows that the vertical axis shows the transmittance % and the horizontal axis shows the wavelength (nm).

Furthermore, in Figure 4, the vertical axis shows the maximum transmittance (%) and the horizontal axis shows the wavelength (nm).
This figure shows how the maximum transmittance (%) changes depending on the film thickness after a 500 tlr weather resistance test was conducted under the conditions of %. It has been revealed that the transmittance is almost saturated when the thickness of the protective film is about 50 nm.

Furthermore, FIG. 5 shows the time (horizontal axis) and the maximum transmittance (50 nm) of the results of a weather resistance test with an SiO protective film coated with 1100 nm using the method shown in the example and uncoated glass.
It is clear that the glass coated with the 5fO2 protective film obtained a good value. Of course, similar results can be obtained by coating the dosimeter glass with a protective film in addition to the optical glass described above. Table 2 is shown in relation to this FIG.

Conventional glass for color filters is heated at 60°C and humidity at 90°C.
% atmosphere, white cloudiness occurred after 250 hours. However, as shown in Table-2, 3! (The product with the protective film h has excellent weather resistance with no change over 50011r.

[Effects of the Invention] The present invention has the following effects since the entire surface of the glass is coated with a protective film by the sol-gel method using the dip puffer method. That is,
It has the advantage of improving weather resistance and transmittance, and can coat six glass surfaces in a single coating process, making it an extremely simple process.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram of the dipping process, Figure 2 is a diagram showing the relationship between pulling speed and film thickness, and Figure 3 is a diagram showing the spectral transmittance of uncoated glass and glass coated with SiO2. , FIG. 4 is a diagram showing the relationship between maximum transmittance and film thickness, and FIG. 5 is a diagram showing the relationship between maximum transmittance and test time depending on the presence or absence of a protective film. 1: Optical glass 2: Opposing angle 3: Jig 4: Dip liquid agent Patent attorney Norio Oko , Name of the invention: Optical glass 3, Relationship with the person making the amendment Patent applicant: Toshiba Glass Co., Ltd. Representative: Hironaga Aihara 4, Agent: Tsunoda Building, 4-41-11 Kamata, Ota-ku, Tokyo 144 Japan Within Ogo Patent Office 5, Subject of amendment ■ Claims column of the specification ■ Detailed explanation of the invention column 6 of the specification, Contents of amendment ■ Correct the claims of the specification as shown in the attached sheet ■-1 “Method A” described in page 3, line 13 of the specification is changed to “(
(b) method”. ■-2 “Decrease in visible wavelength J” described in page 3, line 14 of the specification
is corrected to "decreased transmittance of visible wavelengths". ■-3 [r tus j written in line 9 of page 4 of the specification]
Correct to nmj. (2)-4 The description in the first and second lines of page 6 of the specification is deleted. (1)-5 "16th page" written on page 10, line 15 of the specification is corrected to "full surface." Scope of claims

Claims (1)

[Claims] SiO 80% by weight or more, Al_2O_3, TiO_2
, ZrO_2, and CeO_2 at a thickness of 20 μm or more, comprising 0 to 20% by weight of at least one selected from the group consisting of
Optical glass characterized by coating the entire surface of the glass with a 200 μm film.