JP3518240B2 - Manufacturing method of laminate - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a laminate.

[0002]

2. Description of the Related Art A window glass is stained with various substances.
Dirt reduces the transparency of the window glass and reduces the comfort of the living space. Not only is it extremely labor intensive and costly to remove dirt, but it is also dangerous in the case of window glass of a high-rise building. Organic substances such as carbon are typical substances for window glass stains.Outdoor organic stains are derived from soot from factories and exhaust gases from cars, and indoor organic stains are derived from cigarettes. It is derived from smoke, soot from air conditioning exhausts, oil vapor from the kitchen, and oil on human skin. Further, in the indoor side, drying and condensation are often repeated day and night due to the use of cooling or heating, so that mold may occur on the surface of the window glass.

In recent years, attention has been paid to studies that utilize the photocatalytic properties of metal oxide semiconductors such as titania (TiO ₂ ) to decompose the stains of these organic substances or prevent the formation of mold. For example, JP-A-6-198196,
JP-A-6-278241 describes an example in which TiO ₂ and a noble metal or the like for improving the photocatalytic activity are mixed. Further, Japanese Patent Application Laid-Open No. 8-267646 describes an example in which a photocatalytic active layer is formed on a substrate to make it hydrophilic and impart antifouling property.

According to the conventional studies, TiO ₂ which exhibits photocatalytic activity
As a method of forming a film, a wet method such as fixing fine particles of TiO ₂ with an organic or inorganic binder or forming a titanium organic metal solution by a sol-gel method has been mainly studied. This method can bring out the large photocatalytic activity of TiO ₂ , but it is difficult to obtain a uniform film thickness for coating a large area such as window glass, and the scratch resistance of the film is poor. It was enough. Moreover, it was necessary to be careful to store the coating liquid as a raw material in a certain state.

On the other hand, the DC sputtering method, which has been conventionally used in the production of heat ray reflective glass for buildings and automobiles, can easily coat a large area uniformly and has excellent adhesion of the film to the substrate. In addition, no special care is required for storing the sputtering target. However, TiO ₂ film by usual sputtering film quality is inferior as compared with the film by the wet method, sufficient photocatalytic activity was obtained.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a laminate having an oxide film having improved scratch resistance and having sufficient photocatalytic activity.

[0007]

The present invention SUMMARY OF] is on a substrate, the manufacturing method of the scan <br/> sputtering method is formed by depositing an oxide film mainly containing oxides of Ti by laminate , The Ti
The oxide film to the oxide as the main component, having a predominantly anatase crystal grain, and the work function of the time of measurement in air in the range of 4.5～6.0EV, constant amount 1μW provides a method for producing a laminate which tilt relative to come out ultraviolet energy of electron number when irradiated with ultraviolet light of greater than or equal to energy, characterized in der Rukoto below 8.5 Y / eV.

A technique for forming an oxide film containing Ti as a main component (hereinafter, simply referred to as a Ti oxide film) from a metal target containing Ti as a main component by a reactive DC sputtering method in an oxidizing atmosphere without heating the substrate is used. At present, it is very popular and has already been used for manufacturing heat-reflecting glass and the like.
However, the TiO ₂ film formed by this method is amorphous in terms of X-ray and exhibits almost no photocatalytic activity. In order to obtain photocatalytic activity, first, anatase-type crystal grains having high photocatalytic activity must be grown on the film. Also,
The degree of oxidation of the Ti oxide film is also an important factor. When the Ti oxide film tends to be reduced, a level of metallic Ti or the like is formed in the band, the band gap becomes unclear, and the photocatalytic performance tends to deteriorate.

The degree of oxidation of the Ti oxide film is measured by a surface analyzer (AC-1 manufactured by Riken Keiki) in the atmosphere,
It can be evaluated by 1) the work function and 2 ) the number of electrons that appear when an ultraviolet ray having an energy of a certain value or more is applied. Figure 1 shows the ultraviolet energy (eV) and the amount of light emitted from the film 1
The schematic diagram of the relationship with the number of electrons per μW (Y) is shown. The schematic diagram of the data which measured the inclination (Y / eV) with respect to the unit energy of ultraviolet rays is shown. If the degree of oxidation of the film is high, the number of emitted electrons is small and the inclination becomes small. In the present invention, the work function is in the range of 4.5 to 6.0 eV, and the inclination of the number of electrons that appears when ultraviolet rays having an energy of 1 μW or more and a certain energy or more are applied to the ultraviolet energy is 8.5 Y. It is important to form so as to be less than / eV . The “constant value” is about 5.8 eV, although it depends on the measurement conditions. Further, when converted to the case where the light quantity is 0.35 μW, the inclination is 3.0 Y / eV or less.

The present inventors have studied various methods, and as a result,
It was found that by performing a specific operation, anatase type crystal grains can be grown and the degree of oxidation of the Ti oxide film can be made sufficient.

In the present invention, during the formation of the Ti oxide film, the substrate is preferably heated to a temperature of 100 ° C. or higher and a softening temperature of the substrate or lower, and the oxygen partial pressure is set to 4 mTorr or higher. If the temperature is lower than 100 ° C, the anatase type crystal grains do not grow sufficiently. Further, in practice, it is preferable to use a glass substrate as the base, and therefore, the upper limit of the heating temperature is preferably 650 ° C. 65
If the temperature is higher than 0 ° C, the glass substrate is softened by heat and is distorted. Particularly, 200 to 650 ° C is preferable.

The heating of the substrate is an important operation in terms of growth of anatase type crystal grains, but the photocatalytic activity may not be sufficient depending on the conditions. By setting the oxygen partial pressure to 4 mTorr or more, the degree of oxidation of the Ti oxide film can be made sufficient.

In the present invention, it is also preferable that after the Ti oxide film is formed, the substrate is heated to a temperature of 100 ° C. or higher and a softening temperature of the substrate or lower. The reason why the temperature range is preferable is for the same reason as described above, and particularly 200 to 65
0 ° C is preferred. If the heating is performed during the film formation and further after the film formation, the growth of the anatase type crystal grains becomes more complete.

[0014] In the case of forming a Ti oxide film on a glass substrate in order to prevent diffusion into the Ti oxide film of sodium in the glass, under the alkali barrier between the glass substrate and the Ti oxide film I need a coat. Usually, a film containing an oxide of Si as a main component is used. The film containing Si oxide as a main component may be formed by any method. Figure 2
FIG. 3 shows a cross-sectional view of an example of the laminated body obtained by the present invention. 1 A Rukaribari A film, 2 T i oxide film, 11
A group member.

Geometry of a film whose main component is an oxide of Si
The film thickness is preferably 1 to 100 nm. If it is less than 1 nm, the alkali barrier performance is not sufficient,
Even if it exceeds m, there is no difference in alkali barrier performance and the efficiency is poor. The geometric thickness of the oxide film of Ti is from 3 to 500
It is preferably nm. If it is less than 3 nm, the photocatalytic activity is insufficient, and if it exceeds 500 nm, there is no difference in the photocatalytic activity and the efficiency is poor.

In the present invention, one or more functional films selected from the group consisting of metal oxides, metal nitrides and metal carbides can be formed between the glass and the Ti oxide film. The functional film may be formed by any method. Undercoat alkali barrier when functional film having an alkali barrier property is not required.

[0017]

In the present invention, the anatase type crystal grains grow in the Ti oxide film by heating the substrate during film formation or after heating after film formation. By increasing the oxygen partial pressure during film formation, T
The i-oxide film has a sufficient degree of oxidation. Also, since the sputtering method is used, the adhesion of the film to the substrate is strong,
A film having strong scratch resistance can be obtained.

[0018]

EXAMPLES In the following examples, Examples 1 to 5 are examples of the present invention, and Examples 6 to 11 are comparative examples. The film forming conditions of the films used in Examples and Comparative Examples are as shown in Table 1. The photocatalytic activity of these films was evaluated as follows. The film surface of the sample size 4.5 cm × 5.0 cm × 2 mm face up to the path Irekkusu steel container (3 liter capacity),
Several hundred ppm of acetaldehyde vapor was added. Next, ultraviolet light was applied from the outside of the container to the film surface of the sample with four 6 W black lights. The acetaldehyde concentration in the container was measured at regular intervals with a gas detector tube, and the rate of decrease of the acetaldehyde concentration was measured. Scratch resistance of these films Taber test (abrasion wheel CS-10F, load 500 g) was evaluated Te <br/> seek haze value change ΔH of about Taber 100 rotated by. The case where ΔH was less than 5 was evaluated as ◯, and the case where ΔH was 5 or more was evaluated as x.

The degree of oxidation of the film was evaluated by determining the slope of the work function and the number of electrons with respect to the ultraviolet energy using a surface analyzer (AC-1 manufactured by Riken Keiki). The amount of light when the slope was calculated was 0.35 μW. The results are summarized in Table 2. The "concentration reduction rate" in the table means the acetaldehyde concentration reduction rate (ppm / hour).

[Example 1] A washed float glass plate having a thickness of 2 mm was set in a sputtering apparatus and exhausted to a level of 10 ^-6 Torr.
Next, under the conditions shown in Table 1, a SiO ₂ film (geometric film thickness 50 n
m) / Ti oxide film-1 (200 nm) was formed. This film exhibited sufficient photocatalytic activity and also showed practically sufficient scratch resistance. The numbers in parentheses are the geometrical film thickness,
The same applies to the following. The number in parentheses in Table 2 is the geometric film thickness (nm). In addition, in Tables 1 and 2,
Simply indicated as TiO ₂ -1 the Ti oxide film -1, is also the same or less.

Example 2 In the same manner as in Example 1, a SiO ₂ film (50 nm) / Ti oxide film-1 (20 nm) was formed. This film exhibited sufficient photocatalytic activity and also showed practically sufficient scratch resistance.

Example 3 In the same manner as in Example 1, a SiO ₂ film (50 nm) / Ti oxide film-3 (200 nm) was formed. After the film formation, this film was heat-treated in air at 600 ° C. for 1 hour. This film exhibited sufficient photocatalytic activity and also showed practically sufficient scratch resistance.

Example 4 A TiN _x film (30 nm) / Ti oxide film-1 (200 nm) was formed in the same manner as in Example 1. This film exhibited sufficient photocatalytic activity and also showed practically sufficient scratch resistance.

Example 5 In the same manner as in Example 1, Ti oxide film-3 (50 nm) / T.
iN _x (10 nm) / Ti oxide film-3 (20 nm) /
A Ti oxide film-1 (200 nm) was formed. This film exhibited sufficient photocatalytic activity and also showed practically sufficient scratch resistance.

Example 6 In the same manner as in Example 1, a SiO ₂ film (50 nm) / Ti oxide film-2 (200 nm) was formed. This film showed practically sufficient scratch resistance, but it was confirmed that the photocatalytic activity was inferior to that of Example 1.

Example 7 In the same manner as in Example 1, a SiO ₂ film (50 nm) / Ti oxide film-3 (200 nm) was formed. This film showed practically sufficient scratch resistance, but it was confirmed that the photocatalytic activity was inferior to that of Example 1.

Example 8 In the same manner as in Example 1, a SiO ₂ film (50 nm) / Ti oxide film-4 (200 nm) was formed. This film showed practically sufficient scratch resistance, but it was confirmed that the photocatalytic activity was inferior to that of Example 1.

Example 9 A SiO ₂ film (50 nm) / Ti oxide (200 nm) was formed by the sol-gel method. This film showed sufficient photocatalytic activity, but it was confirmed that the scratch resistance was inferior to that of Example 1.

Example 10 In the same manner as in Example 1, TiN _x (30 nm) was deposited.
This film showed practically sufficient scratch resistance, but it was confirmed that the photocatalytic activity was inferior to that of Example 1.

Example 11 In the same manner as in Example 1, Ti oxide film-3 (50 nm) / T.
iN _x (10 nm) / Ti oxide film-3 (20 nm) was formed. Although this film showed sufficient scratch resistance in practical use,
It was confirmed that the photocatalytic activity was inferior to that of Example 1.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

According to the present invention, it is possible to obtain a laminate having a photocatalytic activity equivalent to that of a titanium oxide film formed by the wet method and having excellent scratch resistance. Therefore, it can be used as it is for a window glass for a building without taking any measures for improving scratch resistance.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the relationship between ultraviolet energy and the number of electrons emitted from a film.

FIG. 2 is a sectional view of an example of a laminate obtained by the present invention.

[Explanation of symbols]

1: alkaline burr A film 2: Ti oxide film 11: substrate

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C23C 14/34 C23C 14/34 M

Claims (5)

(57) [Claims] 1. A substrate is deposited on a substrate by a reactive DC sputtering method in an oxidizing atmosphere from a metal target containing Ti as a main component to form a substrate having a temperature of 100 ° C. or higher and a softening temperature of the substrate or lower.
And the oxygen partial pressure should be 4 mTorr or more.
As a result, in the method for manufacturing a laminated body in which an oxide film containing Ti oxide as a main component is formed, the oxide film containing Ti oxide as a main component mainly contains anatase type crystal grains. And the work function when measured in the atmosphere is 4.5 to
It is in the range of 6.0 eV, and the inclination of the number of electrons emitted when an ultraviolet ray having a light amount of 1 μW and an energy of a certain value or more is applied to the ultraviolet energy is 8.5 Y / eV or less. Production method. 2. The method for producing a laminate according to claim 1, wherein after the oxide film containing an oxide of Ti as a main component is formed, the base is heated to a temperature of 100 ° C. or higher and a softening temperature of the base or lower. 3. The geometric film thickness of the oxide film containing Ti oxide as a main component is 3 to 500 nm.
The method for producing a laminated body according to. 4. The laminated film according to claim 1, wherein a film containing Si oxide as a main component is used between the substrate and the oxide film containing Ti oxide as a main component. Body manufacturing method. 5. The method for producing a laminate according to claim 4, wherein the film containing Si oxide as a main component has a geometric film thickness of 1 to 100 nm.