JPH03218822A - Ultraviolet screening glass - Google Patents

Abstract

PURPOSE:To manufacture an ultraviolet screening glass of superior durability and high visibility beam transmittance and high radiation refractive index by composing high refractive index films or low refractive index films forming an air side outermost layer composed of an oxide containing at least one of Zr, Ti, Hf, Sn, Ta and Bi and at least one of B, Si and P. CONSTITUTION:An ultraviolet screening glass is formed by laminating high refractive index films and low refractive index films alternately on a transparent base. The transparent base 1 is composed of glass, plastic or the like. It is preferable to compose high refractive index films 2, 4, 6, 8, 10 and 12 of an oxide composed mainly of at least one kind of Zr, Ti, Hf, Sn, Ta and bi and at least one kind of B, Si and P, and in the case that an air side outermost layer is not formed with the high refractive index films, the high refractive index films can be composed of ZrO2, TiO2, HfO2, SnO2, Ta2O5, Bi2O3 and the like stabilized by ZrO2 and Y2O3. The material for the low refractive index films 3, 5, 7, 9, 11 and 13 is not limited, and particularly the air side outermost layer 13 should be composed of low refractive index oxidized films containing at least one kind of Zr, Ti, Hf, Sn, Ta and Bi and at least one kind of B, Si and P.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ultraviolet blocking glass, and particularly to an ultraviolet blocking glass having excellent durability, high visible light transmittance, and high heat ray reflectance. It is.

[Prior Art] Ultraviolet blocking glass is used not only as a protective glass for solar cells for spacecraft, but also as laminated glass for automobiles. The former is intended to prevent solar cells from deteriorating due to ultraviolet rays, and the latter to prevent discoloration of interior materials and drivers from sunburn. In other words, UV-blocking glass for spacecraft, which is used to prevent the strong chemical effects of ultraviolet rays, which have higher energy than visible light, is made by adding UV-absorbing components such as cerium oxide to the glass itself. type, or a reflective type that is transparent to ultraviolet rays and has two types of thin films with different refractive indices laminated alternately? . The film materials used for the reflective type are those with a low refractive index such as fluoride such as HgFi or Stow, and those with a high refractive index such as ZrOg are generally used.

In laminated glass, this function is achieved not by the glass itself, but by adding an ultraviolet absorber to the interlayer film.

[Problems to be Solved by the Invention] The ultraviolet absorbing glass contains CeO. , TiO■ and other rare earth elements or transition metal oxides are added to take advantage of their ultraviolet absorption. Since these elements can generally have several valences, it is not possible to make them have only a specific valence in the glass. That is, colored centers tend to occur in the visible range. Furthermore, since the oxidation-reduction atmosphere changes during glass production, it is also difficult to control the ratio to a constant value. Therefore, it is difficult to control optical performance at a constant level. Furthermore, the absorption spectra of these in glass are broad and have poor wavelength selectivity.

For these reasons, the visual field of absorption in the ultraviolet region extends to the visible region, resulting in problems such as a yellowish tinge.

On the other hand, laminated type UV-blocking glass with an interlayer film that has UV-absorbing properties is advantageous in this respect, but it cannot be used in applications where a single plate is desired, and the structure inevitably makes it thicker and thinner. The problem is that it is difficult.

Ultraviolet blocking glass has a multilayer structure in which films with high refractive index and low refractive index that are transparent to ultraviolet rays are laminated alternately on the glass.By appropriately selecting the film structure, the UV blocking area and reflectance can be freely selected to some extent. There are advantages that can be achieved.

Ultraviolet blocking glass that utilizes this interference is usually formed into a film using a vacuum evaporation method. The vacuum evaporation method has the advantage of being able to form a film in a short time due to its fast film formation speed, but since the evaporation source is so small that it can be regarded as a point, it is necessary to rotate the substrate in order to obtain a uniform film distribution. Furthermore, if the substrate is large, this is not possible, so it is necessary to use multiple evaporation sources and install a film thickness correction plate. Furthermore, it is generally difficult to maintain a constant film formation rate, and control using an optical monitor must be used in combination, and in order to obtain good film quality, it is usually necessary to heat the substrate to a temperature of 300° C. or higher. For this reason, it is actually extremely difficult to apply it to large-area glass.

On the other hand, the sputtering method has a wide target corrosion area. Since the particles spattered from the entire surface of this wide area adhere to the substrate, the film thickness is theoretically more uniform than the vacuum evaporation method. In addition, since the energy possessed by each particle is extremely large compared to vacuum evaporation, the film has excellent adhesion to the substrate, and a durable film can be easily obtained without heating the substrate. have. There are two types of sputtering methods: high-frequency discharge and direct current discharge. The former method has the advantage of being able to use an insulating target and allowing a wide selection of materials to be formed, but requires a matching circuit and is not suitable as a coating device for large-area glass such as those used in automobiles or architecture.

The latter does not require a matching circuit and is widely used as a large-area coating device, but it requires a conductive target and there are restrictions on the film materials that can be formed. When making UV-blocking glass using interference, two types of glass are essential: one that is transparent in the ultraviolet region and one that has a high refractive index and one that has a low refractive index.Currently, there is no material that can be stably sputtered with a low refractive index using direct current. For these reasons, a large-area film with excellent ultraviolet blocking performance has not been obtained.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems. The high refractive index film or low refractive index film that is the outermost layer on the air side of the shielding glass is made of Zr, Ti.
, Hf, Sn, Ta, Bi. Among Zn and In, the smaller <<
The present invention provides an ultraviolet blocking glass characterized by being an amorphous film mainly composed of an oxide containing at least one of B, St, and P.

FIG. 1 is a sectional view showing an embodiment of the present invention. 1 is a transparent substrate made of glass, plastic, etc. In addition to ordinary soda lime glass, the substrate may be glass colored blue, bronze, gray, green, etc. to reduce visible light transmittance. Especially when applied to automobiles, energy in the ultraviolet region can be blocked to a large extent by interference films, but visible light transmittance TV and solar energy transmittance T7 are high, so these absorbing glasses can be used to improve heat ray blocking performance. It is preferable to aim for this. Further, it is also preferable to similarly improve the total ultraviolet blocking performance by using ultraviolet absorbing glass. Alternatively, in addition to the transparent films 2 to 7, a film absorbing ultraviolet rays, visible rays, or infrared rays may be formed on the substrate or between the eyebrows to adjust the overall transmittance of ultraviolet rays, visible rays, or solar energy. 2,4
．． 6 is a high refractive index film, Zr, Ti, Hf, S
At least one of n, Ta and B, SL,
Is it made of a high refractive index film whose main component is an oxide containing at least one type of P? Although preferred, if the high refractive index film is not the outermost layer on the air side, ZrO*, ZrO* + TiOz stabilized with YtOs, HfOa,
It may be composed of SnO*, Tasks, BLOs, etc., and is not particularly limited. B as a high refractive index film,
When using an oxide containing at least one of St and P, it is not preferable if the content of B, SL, and P is too high because the refractive index becomes too low. Usually ZrOa,T
iOa. HfO*, Snow, TasOs, Bi*O
Zr (h. TiOa. HfOz. Snow,
For a total of 100 parts of oxides selected from Taxes, Bi20s, Bass, SiO■, and phosphorus oxide (Pu
ps. The total molar ratio of the oxides selected from pto4, PJs) is preferably in the range of O to 100 parts, preferably O to 70 parts, particularly O to 50 parts.

However, the refractive index of the film decreases as the content of Btus, Styx, and phosphorus oxide increases, so the content of boron, silicon, and phosphorus may be selected based on the optically required refractive index.

The high refractive index film is the outermost layer on the air side, and is it a single plate? When used, the total of at least one of B, St, and P should be Zr to improve scratch resistance due to the amorphization of the film.
Oi, TiO*, HfOz, Snow, Tai
In a film whose main component is an oxide such as Os+Bison, ZrO*. Tiot, HfO2, SnO■l
Total 1 of oxides selected from Tails, Bi2'g
Balm, SiO■, phosphorus oxide (P*O
i. The total amount of oxides selected from P2d4, P20s) is contained in a molar ratio of 5 to 100 parts, preferably 1O to 70 parts, particularly 20 to 50 parts. Further, as the base oxide film, among the above-mentioned ZrO■, TiO■, etc., ZrO■ is particularly preferable in terms of film formation speed and scratch resistance, and as additives for making it amorphous, SL, B, especially Si is good in terms of durability.

However, the refractive index of the film is B20. , SiO2 decreases as the content increases, so the content of boron or silicon may be selected based on the optically required refractive index.

The refractive index of the high refractive index film is preferably 2.0 or more.

3.5.7 in Figure 1 is a low refractive index film, and the material is not particularly limited, but especially the outermost layer on the air side? Regarding Zr
, Ti, Hf, Sn, Ta, and Bi and at least one of B, Si, and P. If the content of B, Bi, and P is too small, a low refractive index oxide film will not be obtained, and
On the other hand, if it is too large, reactive DC sputtering becomes difficult and the chemical durability of the film itself decreases, which is not preferable. For this reason, ZrOi. Y! ZrO*, TtO*, HfOz. SnO
In a film containing one or more oxides among a, Taxes, BLOs+, etc., ZrOt+Tilt, HfO
BgOx, Sin for a total of 100 parts of oxides selected from x, Snow, Tag's, Bit's
s, the total amount of oxides selected from phosphorus oxide (PJs. PJ4, P2011) is 100 to 190 parts in molar ratio.
0 parts, preferably 200 to 1900 parts, especially 300 parts
1900 copies is good. With such a composition, B
, SL, and other glass constituent elements, the film is amorphous and has excellent scratch resistance, and has sufficient durability as the outermost layer on the air side. For applications where durability is particularly required, ZrO■, TiO■, ? axe
A combination of at least one of s and SiO2 is preferable, and among these, a combination of ZrOi and SiO2 is particularly preferable. The refractive index of the low refractive index film is preferably 1.7 or less, particularly 1.6 or less.

Table 1 specifically shows the properties of various amorphous oxide films suitable for the high refractive index film and the low refractive index film of the present invention. Films were formed by reactive sputtering using target compositions listed in the table. Crystallinity is
Observation was made by thin film X-ray diffraction. In addition, the scratch resistance is the result of a rubbing test using a sand eraser, where ○ indicates that there were almost no scratches, and × indicates that scratches occurred easily.

Wear resistance was determined by the Taber test (wearing wheel CS-1, weight 5
00g, 1000 rotations), those with haze within 4% were rated O, and those with haze over 4% were rated ×. Acid resistance is 0.1
As a result of immersion in N HSOJ for 240 hours, the TV
(Visible light transmittance), Rv (Visible light reflectance) changes within 1% compared to before immersion are ○, 1 to 4% are △, and the film has dissolved and disappeared. It was set as ×.

Alkali resistance is 0. As a result of immersion in IN NaOH for 240 hours, those whose TV and Rv changed within 1% from before immersion were rated O, and those whose membranes had dissolved were rated ×.

In the boiling test, after 2 hours of immersion in water at 100° C. under 1 atm, the TV and Rv were rated ○ if the rate of change from before immersion was within 1%, and × if it was over 1%.

Regarding the ZrBxOy film, as is clear from Table 1,
It can be seen that when the amount of B in the film is small, a crystalline film tends to be formed, and when the amount of B is large, an amorphous film tends to be formed. It can be seen that the crystalline film has poor scratch resistance and abrasion resistance, whereas the amorphous film has excellent scratch resistance and abrasion resistance. This is an amorphous film.
This is thought to be due to the smooth surface. Therefore, Zr
BxOy film (the atomic ratio X of B to Zr in the film is 0.
10<x) has excellent scratch resistance and abrasion resistance. Since the B203 film is hygroscopic and absorbs moisture in the air and dissolves, it is preferable that X≦3 for the ZrBxOy film.

? The atomic ratio of O (oxygen) to Zr in the rB-Oy film is not particularly limited, but if it is too high, the film structure will become rough and uneven, and if it is too low, the film will become metallic. ZrO■ and B203 tend to reduce transmittance and abrasion resistance of the film.
It is preferable that the amount is such that a composite system of . That is, the composite oxide is ZrL+XBO+. When expressed as s, when B is included in the atomic ratio of X to Zr, y=2+1.5
It is preferable that it is about x.

Furthermore, from Table 1, it can be seen that as the amount of B in the ZrB film increases, the refractive index of the film tends to decrease. The relationship between the composition of the film and the refractive index n is shown in FIG. 2(a). By increasing the amount of B in the film, the refractive index n decreases from about 2.0 to about 1.5.

Therefore, ZrBxO with 0.10<x≦3.2<y≦6.5
The y film is an amorphous oxide film suitable for the purpose of the present invention, which has good scratch resistance and abrasion resistance, and whose refractive index can be freely selected depending on the amount of B.

? Furthermore, as shown in Table 1, as the content of B in the film increases, the acid resistance and alkali resistance tend to deteriorate. When X≧2.3, the acid resistance deteriorates, and when x>4, the alkali resistance decreases and deterioration occurs in the boiling test. Therefore, Zr
B. 0.0, (x<2.3) an amorphous oxide film is preferred.

As described above, by adding boron oxide B203 to the ZrO2 film, the film becomes amorphous and the surface becomes smooth, which is thought to contribute to the improvement of wear resistance and scratch resistance. In addition, the refractive index can be adjusted by adjusting the amount of B, and furthermore,
Compared to the ZrO2 film, the internal stress is smaller, so it is advantageous in terms of adhesion with the adjacent film. This is especially advantageous when forming thick films.

Next, regarding the ZrSziOy film, it is also amorphous, and a film with high scratch resistance and abrasion resistance can be obtained.

For the refractive index, Zr(h (n = 2.15
) and Si02 (n = 1.46) depending on the composition ratio (see Fig. 2(b)). More specifically, in the ZrSiIlOy film, 0.05≦2(
It is preferable that the atomic ratio of SL to Zr in the film is ≦19.

If z<0.05, the film will not become amorphous and sufficient physical durability will not be obtained. Moreover, when z>19, alkali resistance deteriorates. Moreover, y (the atomic ratio of O to Zr in the ZrSizOy film) is the same as that of ZrB. For the same reason as described for the O film, when Si is contained in an atomic ratio of Z to Zr, it is preferable that y=2+2z.

Further, the Z r B KS 1 x O y film is also a film suitable for the purpose of the present invention. The atomic ratio of B to Zr in such a film x. Atomic ratio of Si z. The atomic ratio y of O is x+z≧0
．． 05 is preferable because the film becomes amorphous and has high scratch resistance and wear resistance.

Also, if x+z≦19, the alkali resistance is also good, so in ZrBxSizOy film, 0.05≦x+
It is preferable that z≦19. However, as mentioned above,
B20 is hygroscopic and absorbs moisture from the air and dissolves, so there is no sweetness in the ZrBxSixOy film. It is better not to contain too much. Specifically, in the film, Zr(h<
If B20 is included to the extent that 25 mo1% and Stow < 25 mo1% and the remainder is B20, the chemical durability will be insufficient. That is, Z in the ZrBxSixOy film
When r:B:St (atomic ratio) is 1:x:z, 1/
(1 +x+z)<0.25 and Z/(1+x+z)
<0.25, i.e. x+z-3>0 and x-3z+1>
The composition of O is unfavorable in terms of chemical durability. y is ZrB
For the same reason as mentioned in the case of xOy, this film is
Considering a composite system of rO■+BxOa+SiO■, y is preferably about 2+1.5x+2z. Therefore, it is preferable that approximately 2<y<40. Be
The larger the st content, the lower the refractive index of the ZrBxSiiOy film.

An example of a ZrB+StzOy film is shown in FIG. 2(c).

Metals other than Zr, i.e. Ti, Hf, Sn, Ta
, In, and at least one of B and SL also becomes amorphous, providing sufficient scratch resistance and abrasion resistance. TIS 1! The O y film is shown as sample 15 in Table 1 as an example.

Above, ZrBxOy system, ZrStxOy system, ZrBxS
The amount of B or Si added may be adjusted in a film such as ixO, etc. so that it has a refractive index necessary for the above-mentioned high refractive index film or low refractive index film.

The film thicknesses of the high refractive index and low refractive index films are the optical film thickness and the design wavelength λ. Against. It is preferable to set it to /4. The air-side outermost layer may be modified to adjust reflection for visible light.

The outermost layer may be either a high refractive index film or a low refractive index film, but
If it is desired to lower the visible light reflectance, a low refractive index film is preferable. Therefore, when using a low refractive index film such as soda lime glass for the substrate, a high refractive index film is formed on the substrate side, and the films are laminated on top of it in the order of low/high/low/high.
Finally, a low refractive index film is formed.

Design wavelength λ. may be selected depending on the required ultraviolet blocking performance.

Although there is no particular limitation on the number of calendars of the film, if it is too small, the reflection in the ultraviolet region becomes small and the rise becomes gradual, resulting in a decrease in the ultraviolet reflection performance, which is not preferable. Usually 4 or more layers, preferably 6 or more layers.

For those with a large number of calendars, there are no particular restrictions, and you can decide based on the required performance.

There are no particular limitations on the film forming method. Any of the vapor deposition method, ion blating method, and sputtering method may be used,
For large area applications, DC reactive sputtering using an alloy target of Zr and Si as a low refractive index target is preferred. In the case of vapor deposition or ion blating, a pelletized mixed oxide may be used as the evaporation source.

[Function] By using optical interference between a high refractive index film and a low refractive index film, it is possible to create an ultraviolet blocking glass that has high transmission and low reflection for visible light and high reflection for ultraviolet light. Design wavelength. The rising wavelength of this reflection can be selected by appropriately selecting . If the film number is small, this rise will be gradual, and the reflectance itself in the ultraviolet region will also be small, resulting in a decrease in ultraviolet shielding performance. Increasing the number of calendars is preferable because the reflectance in the ultraviolet region increases, the rise of reflection becomes steeper, and the reflection in the visible region also decreases.

The thickness of the outermost layer on the air side is adjusted to reduce reflection in the visible range. Further, for this purpose, it is more effective to place the low refractive index layer as the outermost layer.

[Example] A glass substrate was set in a vacuum chamber, and I
Exhausted to rr. After introducing a mixed gas of argon and oxygen and adjusting the pressure to 2 x 10-” Torr, a zirconium and boron alloy target (70% Zr in atomic ratio, 8
30%) as a high refractive index film by sputtering ZrB.
xOy film was formed by 410 people (layer A).

Next, an alloy target of zirconium and silicon (Z
ZrSi. 0. Films were formed by 560 people (B layer). Subsequently, layers A, B, A, and B are alternately formed, and finally a ZrSixOy film is formed. 000 people formed a total of 12 layers of UV-blocking glass.

The visible light transmittance Tv of the ultraviolet blocking glass thus produced. The visible light reflectance Rv and the reflectance at 335 nm were 92%, 7%, and 94%, respectively, and an ultraviolet blocking glass with high transmittance in the visible range and excellent ultraviolet reflection performance was obtained.

[Effects of the Invention] The ultraviolet blocking glass using an interference filter type multilayer film can dramatically increase the reflection in the ultraviolet region without lowering the transmittance in the visible region. In addition, visible reflection can be suppressed by appropriately selecting the number of layers, design wavelength, and thickness of each film.

As a low refractive index film, ZrO■, Y. 0. Zr02, TaaOs, SnO. By using a composite oxide film consisting of one type of oxide such as BitOs and one type of oxide such as SL, B, and P, it is possible to create ultraviolet reflective glass that is mechanically and chemically durable.

By using an oxide film containing the same element as the low refractive index film as the high refractive index film, the adhesion between each layer is increased, and by making the film amorphous, a film with excellent scratch resistance can be obtained.

Combining a UV-blocking film and a heat-reflecting film can prevent not only heat, but also sunburn for people and UV deterioration and discoloration of indoor interior materials.

Direct current sputtering is suitable for coating large area glass, but in this case, Zr, Ta, T, etc.
By using an alloy target containing i or the like, sputtering stability and film formation speed can be improved at the same time.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an example of the ultraviolet blocking glass of the present invention. FIG. 2(a) is a diagram showing the relationship between the content of B in the ZrBxOy film and the refractive index n of the film. Figure 2(b) shows Zr
Siyo0, what is the relationship between the Si content in the film and n? , FIG. 2(C) shows Z r B ■S i z O , Si in the film
Contains '1・1
・．． A diagram showing the relationship between abundance and n, Figure 2 (d
) is a relationship diagram between the Si content in the TiSizOy film and n. 1: Transparent substrate 2, 4, 6, 8, 10, 12: High refractive index film 3
, 5, 7, 9, 11, 13: low refractive index film l3
: Air side outermost layer (Figure 1 B203 Er BxOy, FjT'4")
(lrRe7-zZγQ20Bx03 Fig. 2 (a) ?・5゛・O Saitsukanchu ■, .2,5, .2(+-Hy
γ・Fig. 2 Cb) 2r ellS; x 01 pf ノSiOλ 3roL+ S;

Claims (2)

[Claims] (1) Ultraviolet blocking glass formed by alternately laminating multiple layers of high refractive index films and low refractive index films on a transparent substrate, where the high refractive index film or the low refractive index film is the outermost layer on the air side. Ultraviolet blocking glass characterized by being an amorphous film mainly composed of an oxide containing at least one of Zr, Ti, Hf, Sn, Ta, and Bi and at least one of B, Si, and P. . (2) Ultraviolet blocking glass formed by laminating multiple layers of high refractive index films and low refractive index films alternately on a transparent substrate, the outermost layer on the air side being a low refractive index film and containing Zr.
, Ti, Hf, Sn, Ta, and Bi and at least one of B, Si, and P.