JPH03218821A - Heat ray reflective glass - Google Patents

Abstract

PURPOSE:To manufacture heat ray reflective glass of superior durability, high visual beam transmittance and heat ray reflectance by providing high refraction index films or low refraction index films forming an air side outermost layer composed mainly of an oxide containing at least one of Zr, Ti, Hf, Sn, Ta, Bi, Zn and In and at least one of B, Si and P. CONSTITUTION:A heat ray reflective glass is formed by laminating alternately high refractive index films 2, 4 and 6 and low refractive index films 3, 5 and 7 on a transparent base 1. The transparent base 1 is composed of glass, plastic or the like. It is preferable that the high refractive index films 2, 4 and 6 are mainly composed of an oxide containing at least one of Zr, Ti, Hf, Sn, Ta, Bi, Zn and In and at least one of B, Si and P, and in the case that the high refractive index film is not forming an air side outermost layer, the same can be composed of ZrO2, TiO2, HfO2, SnO2, Ta2O5, Bi2O3, ZnO, In2O3 or the like stabilized by ZrO2 and Y2O3. The material for the low refractive index films 3, 5 and 7 is not limited, and particularly an air side outermost layer 7 should be composed of low refractive index films containing at least one of Zr, Ti, Hf, Sn, Ta, Zn, In and Bi and at least one of B, Si and P.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heat ray reflective glass, and particularly to a heat ray reflective glass that is excellent in durability and has high visible light transmittance and high heat ray reflectance. It is.

[Conventional technology] Heat-reflecting glass is widely used in architectural buildings.

Recently, from a design standpoint, multilayer coatings of about 2 to 4 layers have become mainstream, and sputtering methods that allow optical design over large areas have been adopted. Also, with an emphasis on color tone, optical interference is actively utilized. Its composition is a metal film such as Cr, Ti, SOS, etc. or T as a heat reaction film.
Nitride films such as iN and ZrN are mainly used. In order to utilize interference, a transparent oxide film with a high refractive index such as TiO■ or SnO■ is used. By combining these materials, a heat-reflecting glass having desired reflectance, transmittance, and color tone is produced.

[Problems to be Solved by the Invention] Heat-reflecting glass for buildings generally has a high reflectance, a low transmittance, and a vivid color tone of reflection.

Recently, demand for heat-reflecting glass for passenger cars has rapidly increased in order to improve comfort. However, for passenger cars, legal regulations require that the visible light transmittance be 70% or higher, and low reflectance and neutral reflective color tone are desired.

To meet this requirement, we use a heat ray reflective film on the glass.
A two-layer protective coating or a three-layer structure in which a heat ray reflecting film is sandwiched between transparent oxide films are known. In the former case, by thinning the transparent oxide film of the protective coat, the light interference effect can be reduced and a neutral reflective color tone can be obtained. However, since it does not utilize interference, it is disadvantageous in terms of transmittance, and the heat ray reflective film cannot be made thick. Therefore, there was a problem in that the difference in selective transmittance between visible light and heat rays could not be made large, or in other words, the heat ray blocking performance could not be improved that much. The latter three-layer heat-reflecting glass is advantageous in terms of transmittance because it utilizes interference, and therefore the heat-reflecting film can be made thicker. That is, the difference between visible light and heat ray transmittance can be increased, and a glass with excellent function as a heat ray reflective glass can be obtained. However, due to the use of interference, the reflected color tone appears pale pink, and there is a problem in that it is not possible to obtain a completely neutral reflected color.

The interference filter type heat-reflective glass, which has a multilayer structure by alternately laminating high-refractive index and low-refractive-index transparent oxide films, not only provides a neutral reflective color tone, but also maintains high visible light transmittance. Furthermore, it is currently the best heat-reflecting glass for automobiles because it can dramatically increase the reflectance in the near-infrared region.

This interference filter type heat ray reflective glass 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, when the substrate is large, such as automobile glass, this is not possible, so it is necessary to use a plurality of evaporation sources and to install a film thickness correction plate.

Furthermore, it is generally difficult to keep the film formation rate constant, and control using an optical monitor must be used in combination. Further, in order to obtain good film quality, it is usually necessary to heat the substrate to 300° C. or higher.

For this reason, it is extremely difficult to apply it to large glass such as those used in automobiles.

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. are doing. There are two types of sputtering methods, one using high frequency discharge and the other using direct current discharge. The former has the advantage of being able to use an insulator target and allowing a wide selection of materials to be formed into films, 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 interference filter-type heat-reflecting glass, two types of glass are essential: one that is transparent 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 low refractive index. For these reasons, it has not been possible to obtain a material that has a large area, high transmittance, low reflection, neutral reflective color, and excellent heat ray reflection performance.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and provides an interference filter in which multiple layers of high refractive index films and low refractive index films are alternately laminated on a transparent substrate. The high refractive index film or low refractive index film that is the outermost layer on the air side is made of Zr, Ti, Hf, Sn, Ta, Bi,
At least one of Zn, In and B, Si, P
The present invention provides a heat ray reflective glass characterized by being an amorphous film mainly composed of an oxide containing at least one of the above.

FIG. 1 is a sectional view showing an embodiment of the present invention. ■ is a transparent base 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 transmittance. Particularly in the case of automobiles, the solar energy reflectance R, of the interference film itself is much higher than that of the glass itself, but the absolute value of the solar energy transmittance TE is still high, so using these absorbing glasses will reduce the total shielding. This is preferable because thermal performance is improved. Alternatively, in addition to the transparent films 2 to 7, an absorbent film may be formed on the base or between the eyebrows to adjust the overall transmittance. 2, 4.6 are high refractive index films, and Zr. Ti, Hf, Sn, Ta. Bi,
Zn,? It is preferable that the high refractive index film is composed mainly of an oxide containing at least one of n and at least one of B, SL, and P. However, if the high refractive index film is not the outermost layer on the air side, In addition, ZrO*. ZrOa, TiOa, Hf02 stabilized with Y2kg. SnOi, TaJ
s. It may be made of Bi20s, ZnO, InJx, etc., and is not particularly limited. B as a high refractive index film,
When using an oxide containing at least one of Si and P, it is not preferable if the content of B, Si, and P is too large because the refractive index becomes too low. Usually ZrO■. Ti0
2. HfO ■. SnO. Tag's, Biass,
In a film whose main component is an oxide consisting of one or more types such as ZnO and IniOa, ZrOi+Til■, H
fOx, Sno2, Taxes, Bit's, Z
B20. , a total of oxides selected from SiOa in a molar ratio of 0 to 100 parts, preferably 0 to 70 parts,
In particular, it is preferably in the range of 0 to 50 parts. however,
The refractive index of the film is Bass. Since the content of SiO2 decreases as it increases, the content of boron or silicon may be selected based on the optically required refractive index. High refraction? When the membrane is the outermost layer on the air side and is used as a single plate, it is necessary to have at least B, S
The total of one or more of i and P is ZrO■, TiO■
, Hf02, SnO. , TatOs. BiJs. ZnO
, In a film whose main component is an oxide such as InzL,
ZrL. DingiL, HfOz, SnOx. Ta20g,
BizOs. The total molar ratio of oxides selected from B20x and SiO is 5 to 100 parts, preferably 1 to 100 parts in total of oxides selected from ZnO and Inz03.
It is preferably contained in an amount of 0 to 70 parts, particularly 20 to 50 parts.

In addition, as the base oxide film, the above-mentioned ZrO■, TiO
Among a, etc., Zr02 is particularly preferable in terms of film formation rate and scratch resistance, and as additives for amorphization, Si, B,
In particular, Si is good in terms of durability. The refractive index of the high refractive index film is preferably 1.7 or more, particularly 2.0 or more.

3.5.7 in FIG. 1 is a low refractive index film, and the material is not particularly limited, but especially for the outermost layer 7 on the air side, Zr
, Ti, Hf, Sn, Ta, Zn, In,
8i and B, Si. Preferably, the film is made of a low refractive index oxide film containing at least one type of P. . If the content of B, Si, and P is too small, a low refractive index oxide film will not be obtained, and if it is too large, reactive DC sputtering becomes difficult and the chemical durability of the film itself decreases. Undesirable. For this reason, ZrO■. ZrOz. stabilized with Y*Os. TiO
*, HfOz, SnOa. TaJi. BLOs. ZnO
, InaOs, etc., in a film containing one or more oxides such as ZrOz. TiOz. HfOz, SnO. TazO
s. The total molar ratio of the oxides selected from B20i and SiOz to 100 parts in total of the oxides selected from BigOi, ZnO, and InaOx is 100 to 1900 parts, preferably 200 to 1900 parts, particularly 300 parts. 1900 copies is good. With such a composition, B,
Since the film is amorphous due to the sufficient content of glass constituent elements such as Si and P, it has excellent scratch resistance and has sufficient durability as the outermost layer on the air side. For applications where durability is particularly required, ZrO2, TiO. TatOs
A combination of at least one of these and Sift is preferred, and among these, a combination of ZrO■ and SiOa is particularly preferred. The refractive index of the low refractive index film is 1.7 or less, especially 1.
．． 6 or less is preferable.

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 targets with the compositions listed in the table. Crystallinity was observed by thin film X-ray diffraction. Furthermore, the scratch resistance is the result of a rubbing test using a sand eraser, where O indicates that there were almost no scratches, and X indicates that scratches occurred easily.

The abrasion resistance was determined by the Taber test (wearing wheel CS-10F, load 500 g, 1000 rotations), and the results were rated ○ if the haze was within 4%, and × if the haze exceeded 4%. Acid resistance is O.
As a result of immersion in IN I{2SO4 for 240 hours, T
V (visible light transmittance). A case where the change rate of R, (visible light reflectance) with respect to before immersion was within 1% was rated as ◯, a case of 1 to 4% was △, and a case where the film had dissolved and disappeared was rated as ×.

Alkali resistance is O. As a result of immersion in 1N 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 ZrB*Oy 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
BxO, film (atomic ratio X of B to Zr in the film is 0.1
A film with (1<x) has excellent scratch resistance and abrasion resistance. B
Since the 203 film is hygroscopic and absorbs moisture in the air and dissolves, it is preferable that X≦3 for the ZrB*Oy film.

The atomic ratio of O (oxygen) to Zr in the ZrBxOy film is not particularly limited, but if it is too large, the film structure will become chewy and the film will become lumpy. If the amount of ZrO and B203 is too low, the film becomes metallic and the transmittance decreases, and the scratch resistance of the film tends to decrease.
It is preferable that the amount is such that a composite system of . That is, the composite oxide is ZrOz+XBO+. When expressed as *, B
When X is included in the atomic ratio to Zr, 3'=2+1
．． It is preferable that it is about 5x.

Furthermore, from Table 1, it can be seen that as the amount of B in the ZrBxOy 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, lrBx% of 0.10<x≦3.2<y≦6.5
The 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. Is the acid resistance bad when X≧2.3? When x>4, the alkali resistance decreases and deterioration occurs in the boiling test. Therefore, Zr
An amorphous oxide film of BxOy (x<2.3) is preferred.

As described above, by adding boron oxide B203 to the ZrOz film, the film becomes amorphous and the surface becomes smooth, which is thought to contribute to improvement in 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 ZrSizOy film, it is also amorphous, and a film with high scratch resistance and abrasion resistance can be obtained.

For the refractive index, Zr02 (n = 2.15
) and Sin2 (n = 1.46) depending on the composition ratio (see Fig. 2(b)). More specifically, in the ZrSizOy film, it is preferable that 0.05≦Z (atomic ratio of Si to Zr in the film)≦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. Also, y (the atomic ratio of O to Zr in the ZrSi.0 film) is approximately y=2+2z when the atomic ratio of Si to Zr is Z for the same reason as described for the ZrBxOy film. It is preferable that

Also, ZrB. The SiiOy film is also a suitable film for the purposes of the present invention. The atomic ratio of B to Zr in such a film x. The atomic ratio Z of Si and the atomic ratio y of 0 are preferably x+z≧0.05 because the film becomes amorphous and has high scratch resistance and wear resistance.

In addition, if X+Z≦19, the alkali resistance is also good, so in the case of ZrBxSizO, 0. 05≦X
It is preferable that +Z≦19. However, as mentioned above, B203 is hygroscopic and absorbs moisture in the air and dissolves, so ZrB. It is better not to contain too much in the SiOy film. Specifically, in the film, ZrO2
B203 is included so much that SiCh is <25mol% and the rest is 8203? Scientific durability becomes insufficient. That is, Z in the ZrBJxiOy film
When r:B:Si (atomic ratio) is 1:x:z, 1/
(1 +x+z) <0.25kz/(1+x+
z) <0.25, i.e. x+z-3>O and x-
A composition in which 3z+1>O is unfavorable in terms of chemical durability. y
Considering this film as a composite system of ZrOa + 820m + SLO■ for the same reason as stated in the case of ZrBmOy, y is preferably about 2+1.5x+2z. Therefore, it is preferable that approximately 2<y<40. The higher the content of B and SL, the higher the ZrB. Size
O, the refractive index of the film decreases.

An example of a ZrB+SizO 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 Si also becomes amorphous, providing sufficient scratch resistance and wear resistance. A TiSizO film is shown as sample 15 in Table 1 as an example.

Above, ZrBxOy system, ZrSitO, system, ZrBxS
The amount of B or St added may be adjusted in the lxOy-based film or the like so that the film 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 outermost layer on the air side is preferably λo/8 to reduce reflection.

The outermost layer may be either a high refractive index film or a low refractive index film, but
If it is desired to further lower the 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 in the order of low/high/low/high, and finally the low refractive index film. Form a refractive index film.

Design wavelength λ. is preferably in the range of 900 to 1100 nm. If it is shorter than this, the heat ray reflection performance will improve because the rise of the reflection will be in the visible range, but the reflection will be colored and 《. On the other hand, if the length is longer than this, the heat ray reflection performance will deteriorate.

There is no particular limit to the number of epochs of the film, but if it is too small, the reflection in the near-infrared region will be small, the rise will be gradual, the heat ray reflection performance will deteriorate, and the ripple in the reflectance in the visible region will increase. I don't like it because it gets bigger.

Usually 4 or more layers, preferably 6 or more layers. There is no particular limit to the number of calendars, and it can be determined based on the required performance, but if the number is too large, productivity will decrease, and depending on the membrane material used, the durability of the membrane due to stress will also decrease.
Taking these into consideration, 14 layers are sufficient for automobiles and the like.

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 a heat-reflective glass that has high transmission and low reflection for visible light and high reflection for near-infrared rays. The rising wavelength of this reflection can be selected by appropriately selecting the design wavelength λ0. If the number of layers in the film is small, this rise will be gradual, and the reflectance itself in the near-infrared region will also be low, resulting in a decrease in heat ray reflection performance. When the number of layers is increased, the reflectance in the near-infrared region increases, the rise of the reflection becomes steeper, and the ripple in the reflection in the visible region also becomes smaller, which is preferable because it prevents the reflection from being colored depending on the viewing angle.

The outermost layer on the air side is at the design wavelength. /8 has the effect of lowering reflection in the visible range, and is also formed to reduce ripple. For this purpose, it is more effective to place the low refractive index layer as the outermost layer.

[Example] A bronze-colored glass substrate with a thickness of 4 mm was set in a vacuum chamber, and the vacuum chamber was evacuated to l x 10-'Torr. Introducing a mixed gas of argon and oxygen to 2 x 10-3To
After adjusting to rr, a ZrBxOy film (A film, refractive index 2.1) was formed as a high refractive index film by sputtering a zirconium and boron alloy target (atomic ratio Zr 70%, 830%). . Next, an alloy target of zirconium and silicon (Zr 10%, Si
Zr as a low refractive index film by sputtering
1,670 Si films (B film, refractive index 1.5) were formed. Similarly, 1190 people received A film, 1670 people received B film,
Film A was formed by 1190 people and film B was formed by 835 people to produce a 6-layer heat-reflecting glass.

Visible light transmittance TV, solar light transmittance TE, and glass surface visible light reflectance R of the heat-reflecting glass made in this way
VG, coated surface visible light reflectance Rvr, glass surface sunlight reflectance REG, and coated surface visible light reflectance Rtv were as follows.

TV=74.6%, T, =56.9%, Rv. =
10.7%. RVF=11.9%, R. ．． =14.9
%, REF=26.0%.

The reflected color tone is expressed in CIE display as x =
0.298, y = 0.322. On the coated surface, x = 0.293, y = 0.319. Since the T of the base glass is about 69% and the RE is about 6.6%, a product with significantly improved heat ray blocking and reflection performance was obtained. In addition, the reflected color tone, which is a particular problem, was also neutral.

[Effects of the Invention] A heat-reflecting glass using an interference filter type multilayer film can dramatically increase reflection in the near-infrared region without lowering transmittance in the visible region. In addition, by appropriately selecting the number of layers, design wavelength, and thickness of each film, visible reflection can be suppressed and the color tone of reflection can be made neutral.

ZrOa, ZrOz. stabilized with Y20s of the present invention is used as a low refractive index film. By using a composite oxide film consisting of one type of oxide such as TazOs, Sn02, Bfz03, etc. and type I oxide of Si, B, P, etc., it is possible to create heat-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.

By using interference, reflection in the near-ultraviolet region can be increased at the same time, so in applications such as automobiles, it can prevent UV deterioration and discoloration of car interior materials.

Direct current sputtering is suitable for coating large areas of glass, but in this case, especially when Si is coated with 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 heat ray reflective 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
Si. 0, Figure 2 (C) shows the relationship between the SL content in the film and n. A diagram showing the relationship between the Si content in the zgsizOy film and n, and FIG. 2(d) is a diagram showing the relationship between the Si content in the TiSiOy film and n. 1: Transparent substrate 2.4, 6: High refractive index film 3, 5, 7: Low refractive index film 7: Air side outermost layer 1 Figure B203 C mole≠Zγ01+Bx03 during medical administration of Er Figure 2 (a) Figure 2 Cb) 54 horse mackerel = S. xO1c) (-? S: Ox zrchS: (h (71shibu,) Fig. 2 (C) Si O2 TrS: 20ke8 east middle C7ruzu・)ding'+
(h+sr(h Figure 2 (cl)

Claims (2)

[Claims] (1) An interference filter-type heat-reflecting glass made by alternately laminating high refractive index films and low refractive index films on a transparent substrate, with the high refractive index film or low refractive index film serving as the outermost layer on the air side. The rate film is Zr, Ti, Hf, Sn, Ta, Bi, Zn,
A heat ray reflective glass characterized in that it is an amorphous film mainly composed of an oxide containing at least one type of In and at least one type of B, Si, and P. (2) An interference filter-type heat-reflecting glass formed by alternately laminating multiple layers of high refractive index films and low refractive index films on a transparent substrate, in which the outermost layer on the air side is a low refractive index film, and the outermost layer on the air side is a low refractive index film, and ,
A hot wire characterized by being an amorphous film mainly composed of an oxide containing at least one of Ti, Hf, Sn, Ta, Bi, Zn, and In and at least one of B, Si, and P. reflective glass.