JP2576662B2 - Heat blocking glass - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat ray shielding glass.

[Related Art] Conventionally, a heat ray blocking glass has been used to block solar energy flowing into a room of a building through a window glass to suppress a rise in the temperature of the room and reduce a cooling load. As a conventional heat ray blocking glass, a glass in which an oxide thin film such as titanium oxide or tin oxide is formed on glass by a spray method, a CVD method, or an immersion method, for example, is known.

Recently, a thin film of not only an oxide but also a metal or a nitride can be freely formed over a large area by a sputtering method. Therefore, a single-layer film system of a transition metal such as chromium or titanium, a metal / oxide film, or a two-layer film system of a nitride film / oxide film, or an oxide film / nitride film / oxide film,
Alternatively, a heat-shielding glass having a three-layer film system of an oxide film / metal / oxide film or a multilayer film structure of a multilayer film or more has been used.

Unlike a single-layer film, a heat-shielding glass having a multi-layer structure of three or more layers can considerably freely select a reflectance and a reflection color tone by utilizing interference. For this reason, demand is increasing for architectural applications that emphasize designability.

In addition, there is also known a heat ray reflection glass called Low-E glass (low emissivity glass) for reflecting a heat ray from the room to prevent a decrease in the temperature of the room and reduce a heating load. . It has an oxide / Ag / oxide film or a stacked film of the structure of oxide film / Ag / oxide film / Ag / oxide film, and is mainly used in cold regions. However, the durability is inferior because the Ag film is used. For this reason, the laminated film is used in the form of a laminated glass or a multi-layer glass so as not to be exposed to the outside. Since this Low-E glass also has a heat ray blocking effect for sunlight, it is also used for some automotive glasses for this purpose.

[Problems to be Solved by the Invention] A heat ray shielding glass in which an oxide film such as titanium oxide or tin oxide is formed on glass by a conventional spray method, CVD method, immersion method or the like can be manufactured at low cost and with good productivity. On the other hand, compared to single-layer or multi-layer heat-shielding glass of metal or alloy system formed by recent sputtering method, heat-shielding performance is slightly inferior, and tin oxide is weak to acid, and chemical safety is low. There was a problem that it was not enough.

In addition, a single-layer heat-shielding glass made of a transition metal such as chromium or titanium generally has a high visible light reflectance R _V of 10 to 50%, and the reflection color is bronze, blue, green, gray, gold, It has a color such as silver. Also, 10% to 60% and low visible light transmittance T _V.

For this reason, it has been unsuitable for application to window glasses for automobiles and general households that require a natural color, that is, a neutral color, a low reflectance and a visible light transmittance of 70% or more. Further, such a metal single-layer film has insufficient durability such as abrasion resistance and chemical safety, and cannot be used as a single plate in applications where the use environment is severe such as for automobiles.

In addition, the above-mentioned type of Low-E glass has a relatively neutral reflection color and has a visible light transmittance of 70% or more, but since the Ag film is used, the abrasion resistance is insufficient. There is a drawback that it cannot be used as a single plate and must be made into a laminated glass or a multi-layered glass.

Further, among conventional two-layered heat ray shielding glasses such as a metal / oxide film and a nitride film / oxide film, those having a neutral color tone, durability, high transmittance, and low reflectance have been obtained. Did not.

In addition, a three-layered heat ray shielding glass in which a film made of a metal such as titanium, zirconium, chromium, or a nitride of these metals is sandwiched between high-refractive-index oxide films also has sufficiently good heat ray shielding performance. By adjusting the thickness of the oxide film, it is possible to reduce the visible light reflectance by using light interference to increase the visible light transmittance to 70% or more. Because it is excellent in durability, it is suitable as a single-plate heat ray shielding glass, but it takes on colors such as blue, pink, or yellow due to light interference, and it is difficult to obtain a natural and neutral appearance There was a problem.

As described above, it has high durability enough to be used as a single plate, has high visible light transmittance, and is 70% or more, and is neutral in both transmittance and reflection color so that it can be used particularly as a window glass of an automobile. No heat-shield glass was obtained.

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and has at least two layers of a heat ray absorbing film and an oxide film on a transparent substrate.
A heat-shielding glass in which the layers are sequentially laminated, wherein the oxide film is the outermost layer on the air side and has a refractive index of 2.0 or less, a ZrB _x O _y film (1.0 ≦ x <2.3, 2.5 ≦ y <5.45) ) Is provided.

The present invention also provides a heat ray blocking glass in which at least two layers of a heat ray absorbing film and an oxide film are sequentially laminated on a glass substrate, wherein the oxide film is an air side outermost layer and has a refractive index of 2.0 or less. ZrSi _z O _y film (0.28 ≦ z <19, 2.56 ≦
y <40) is provided.

The present invention also provides a heat ray blocking glass in which at least two layers of a heat ray absorbing film and an oxide film are sequentially laminated on a glass substrate, wherein the oxide film is an air side outermost layer and has a refractive index of 2.0 or less. ZrB _x Si _z O _y film (0.28 ≦ x + z <19,
2.5 ≦ y <40, where x + z−3> 0 and x−3z + 1>
(Excluding 0)).

The present invention also provides a heat ray blocking glass in which at least two layers of a heat ray absorbing film and an oxide film are sequentially laminated on a glass substrate, wherein the oxide film is an air side outermost layer and has a refractive index of 2.0 or less. TiSi _z O _y film (z ≧ 0.56, y = 2 + 2
z) A heat-shielding glass is provided, which is characterized in that:

FIG. 1 is a cross-sectional view of one example of the heat ray blocking glass of the present invention, wherein 1 is a glass substrate, 2 is a heat ray absorbing film, and 3 is an oxide film having a refractive index of 2.0 or less.

The most significant feature of the present invention is that an oxide film having a refractive index of 2.0 or less is formed in the outermost layer on the air side. If the refractive index of the oxide film on the air side outermost layer exceeds 2.0, the visible light reflectance increases, and as a result, the visible light transmittance decreases, and it becomes difficult to easily obtain a visible light transmittance of 70% or more. . Therefore, the refractive index of the oxide film 3 is 2.0 or less,
It is preferably 1.8 or less, particularly preferably 1.7 or less.

Table 1 specifically shows properties of various amorphous oxide films.
Films were formed by reactive sputtering using targets having the compositions shown in the table.

 The crystallinity was observed by thin film X-ray diffraction.

The abrasion resistance is the result of the rubbing test using a sand eraser.
Indicates that scars were scarcely formed, and x indicates that scratches occurred easily.

Abrasion resistance was measured using the Taber test (wear wheel CS-10F, weight 500
g, 1000 rotations), those with a haze of 4% or less were evaluated as ○, and those with a haze of more than 4% were evaluated as x.

The acid resistance was evaluated by immersing in a 0.1N aqueous sulfuric acid solution for 240 hours, and the rate of change of T _V (visible light transmittance) and R _V (visible light reflectance) with respect to before immersion was within 1%. 4% was evaluated as Δ, and the film dissolved and disappeared was evaluated as ×.

The alkali resistance was determined by immersing in a 0.1N aqueous sodium hydroxide solution for 240 hours. As a result, the film was dissolved when the rate of change of T _V and R _V from before immersion was within 1%. The one that was lost was marked X.

Boiling test, one atmosphere, was immersed for 2 hours in 100 ° C. water, when T _V, the rate of change for the previous immersion R _V is within 1% ○, and as × when 1 percent.

Oxide containing Zr (dicornium) and B (boric acid) ZrB _x
O _y , an oxide containing Zr and Si (silicon) ZrSi _z O _y , Zr, B and S
Regarding the composition of the film composed of the oxide ZrB _x Si _z O _y containing i, the composition of Zr in the respective films of B, Si and O (oxygen)
Assuming that the atomic ratios to are x, z, and y, respectively, the ranges are as follows.

As is clear from Table 1, ZrB _x O _{y satisfies} 1.0 ≦ x. When x <1.0, the refractive index of the film exceeds 2.0, and it becomes difficult to obtain a heat ray cutoff having a visible light transmittance of 70% or more. On the other hand, as x increases,
Although the refractive index of the film decreases (see FIG. 2A), x ≧ 2.3
, The heat resistance is lowered, and the alkali resistance is lowered and the boiling test is degraded when x ≧ 4. Therefore, in the ZrB _x O _y film as the oxide film 3 of the present invention, 1.0 ≦ x <2.3. .
y is considered to be a composite system of ZrO ₂ and B ₂ O ₃ , and ZrO ₂ + xB
When expressed as O _1.5 , y = about 2 + 1.5x, that is, 2.5 ≦ y <5.4
5

As with the ZrB _x O _y film, the refractive index of the ZrSi _z O _y film decreases as z increases (see FIG. 2 (b)). Is high, so B
Since the refractive index becomes 2.0 or less with a smaller amount, 0.28 ≦ z. Further, when z ≧ 19, the alkali resistance of the film becomes insufficient, and the superiority containing Zr is hardly recognized, so that 0.28 ≦ z <19. Similarly for y, ZrO ₂
And consider the SiO ₂ composite systems y = 2 + 2z about, namely 2.56
≤ y <40.

For the ZrB _x Si _z O _y film, similarly, from the viewpoint of the refractive index, 0.28 ≦
x + z. If x + z <19, the alkali resistance is also good, so that in the ZrB _x Si _z O _y film, 0.28 ≦ x
+ Z <19. However, as described above, since B ₂ O ₃ is hygroscopic and absorbs and dissolves moisture in the air, ZrB _x Si _z O
It is better not to contain too much in the _y film.

Specifically, Zr other than O (oxygen) in the film,
When Zr <25 at% and Si <25 at% with respect to the total of B and Si, and B is contained so that the remainder becomes B ₂ O ₃ , the chemical durability becomes insufficient. That is, Zr: B: Si in the ZrB _x Si _z O _y film
If (atomic ratio) is 1: x: z, 1 / (1 + x + z) <0.2
5, and z / (1 + x + z) <0.25, that is, x + z−3>
A composition of 0 and x−3z + 1> 0 has poor chemical durability. y is considered to be a composite system of ZrO ₂ + B ₂ O ₃ + SiO ₂ for the same reason as described in the case of ZrB _x O _y , and y is about 2 + 1.5 _y + 2z. Therefore, approximately 2.5 ≦ y <40. The higher the content of B or Si, the lower the refractive index of the ZrB _x Si _z O _y film. (See FIG. 2 (c)).

As described above, the oxide film containing at least one of B and Si and Zr as the oxide film 3 of the present invention is ZrB _x
O _y film (1.0 ≦ x <2.3,2.5 ≦ y <5.45), ZrSi z O y film (0.
28 ≦ z <19, 2.56 ≦ y <40), ZrB _x Si _z O _y film (0.28 ≦ x
<19, 2.5 ≦ y <40, where x + z−3> 0 and x−3z
+1> 0) is used.

These films have x> 0.10 for the ZrB _x O _y film and ZrSi _z O _y
Z ≧ 0.05 for the film, x + z for the ZrB _x Si _Z O _y film
If ≧ 0.05, the film becomes amorphous and has excellent wear resistance.

As for the TiSi _z O _y film, as shown in FIG.
, The refractive index becomes 2 or less. As for y, y = 2 + 2z, assuming that it is a composite system of TiO ₂ and SiO ₂ .

At least one of B and Si used in the present invention
Oxide film containing species and Zr can be easily coated over a large area by reactive sputtering using direct current from a sintered target such as a mixture of zirconium, boron, silicon, zirconium boride, or a mixture of these. Therefore, it is suitable for use in automobiles, buildings and the like.

As described above, the oxide film 3 as the outermost layer on the air side of the heat ray blocking glass of the present invention contains other components for the purpose of improving durability, adjusting optical constants, stability during film formation, or improving the film formation speed. There is no problem even if it is included. The oxide film 3 of the present invention does not need to be completely transparent, and may be an oxygen-deficient absorptive film, or may partially contain nitrogen or carbon.

The thickness of the oxide layer 3 is not limited, but if it is too thin, sufficient durability cannot be obtained. Therefore, depending on the use, it is preferably at least 50 °, preferably at least 100 °, and particularly preferably at least 150 °. On the other hand, if the thickness is too large, depending on the refractive index, an interference effect occurs and the reflected color becomes strong, so
Å, preferably 700Å or less, particularly preferably 500Å or less.

The film material of the heat ray absorbing film 2 is not particularly limited, and is selected from a metal, a carbide, an oxide, or a composite film thereof depending on an application or a required specification. Specifically, a film mainly composed of one of titanium, chromium, zirconium, tantalum, hafnium, titanium nitride, chromium nitride, zirconium nitride, tantalum nitride, and hafnium nitride is preferable because of its good heat ray absorbing performance.

When the thickness of the heat ray absorbing film 2 is too large, the visible light transmittance is reduced. Therefore, although it depends on the type of the substrate 1 and the refractive index and the thickness of the oxide film 3, it is 1000 ° or less, preferably 800 mm or less is desired. If it exceeds 800 °, especially in the case of a nitride film, the internal stress increases and the film is liable to peel off. Further, if it is too thin, sufficient heat ray absorption performance cannot be obtained, so depending on the film material and the thickness and type of the substrate glass, it is 20 mm or more, preferably 20 to 100 mm.
It is desirable that

The method for forming the oxide layer 3 and the heat ray absorbing film 2 is not particularly limited, and a vacuum deposition method, an ion plating method, a sputtering method, or the like can be used. Is preferred.

In the present invention, a neutral color tone means one having the following characteristics.

That is, when displayed in the CIE color system, the x-coordinates before and after the formation of a coating such as a heat ray absorbing film and an oxide film on the substrate surface,
The change widths of the y-coordinates are Δx and Δy.

Is the color change due to the formation of the film, and the neutral color, the value of this color change, transmission color, each of the reflection color 0.008, 0.032 or less, more preferably 0.007, 0.07
28 or less. However, regarding the reflection color,
Since the reflection color is different between the surface on which the film is formed and the surface on which the film is not formed, it indicates the larger value.

When the heat ray absorbing film 2 is a nitride film, an oxide film is formed between the glass substrate and the nitride film in order to reduce the internal stress of the nitride film and increase the adhesion to the glass substrate. Good.
Another effective method for increasing the adhesion between the glass substrate and the glass substrate is to first form a base film on the glass substrate, then implant high energy ions, and then form a heat ray absorbing film. is there. For example, when a titanium film is formed as a base film and then a high-energy nitrogen ion is implanted and then a titanium nitride film is formed, a titanium nitride film having a very high adhesive force can be obtained as the heat ray absorbing film 2.

[Function] In the heat ray blocking glass of the present invention, the oxide film 3 as the outermost layer on the air side has an optical function by its refractive index, film thickness and the like. That is, it has the effect of lowering the reflectance of the heat ray blocking glass and contributing to the improvement of the visible light transmittance, and at the same time, lowering the stimulating purity of the reflected color and neutralizing the overall color tone. Further, the oxide film 3 has a role of a protective film for improving abrasion resistance and chemical resistance of the heat ray shielding glass.

The heat ray absorbing film 2 functions to absorb sunlight energy and adjusts the visible light transmittance.

Further, the oxide film 3 is made of at least one of B and Si.
In the case of an oxide film containing Zr, B or Si has an effect of lowering the refractive index and also has an effect of improving the wear resistance which is insufficient in the zirconium oxide film.

This is probably because the addition of B or Si, which is a glass component, makes the film amorphous and increases the smoothness of the surface, so that the frictional resistance is reduced and the wear resistance is improved.
Due to such amorphization, abrasion resistance can be imparted to zirconium oxide, which has strong chemical stability against acids, alkalis, etc., and extremely excellent durability that combines both abrasion resistance and chemical stability Donated to the realization of a film with properties.

Example 1 Example 1 A glass substrate was set in a vacuum chamber of a sputtering apparatus and evacuated to 1 × 10 ⁻⁶ Torr. A 4 mm thick blue plate was used as a glass substrate. The same glass substrate was used in Example 2 and thereafter. Introduce a mixed gas of argon and nitrogen to increase the pressure to 2 ×
After 10 ^-3 Torr, titanium was reactively sputtered to form titanium nitride (first layer) of about 20 °. Next, the pressure was switched to a mixed gas of argon and oxygen, the pressure was set to 2 × 10 ⁻³ Torr, and a ZrB ₂ target reactive sputtering was performed to form an oxide film (second layer) composed of Zr and B at about 200 °.

Visible light transmittance of the heat-shield glass thus obtained
T _V , sunlight transmittance _TE , coated surface visible light reflectance R _VF ,
Glass surface visible light reflectance R _VG , color change of transmitted color, reflected color Were 71, 56, 13, 12 (%), 0.0068, and 0.026, respectively.

Further, the transmission color and the reflection color were also neutral colors that could hardly be distinguished from the bare glass.

To examine the durability of the membrane, immerse in 0.1N hydrochloric acid and sodium hydroxide aqueous solution for 6 hours at room temperature or in boiling water for 2 hours.
After immersion for a time, no change was observed in the optical performance.
Acid, further was evaluated in the same manner continue to immersion in after 240 hours in an alkali, T _V, and T _E is not increased 2-3%, degradation was observed. The rubbing test with a sand eraser showed very good scratch resistance with almost no scratches.

Example 2 As in Example 1, zirconium was reactively sputtered on a glass substrate to form zirconium nitride (first layer).
After the formation of 20 °, the mixture was switched to a mixed gas of argon and oxygen to be 2 × 10 ⁻³ Torr. Next, a ZrB ₂ target is reactively sputtered to form an oxide film (second layer) composed of Zr and B approximately.
200 mm formed.

The optical performance T _V , T _E , R _VF ,
The color tone changes of R _VG , transmission color and reflection color are 71, 55 and 1 respectively.
2, 12, (%), 0.0067, and 0.026.

To examine the durability of the membrane, immerse in 0.1N hydrochloric acid and sodium hydroxide aqueous solution for 6 hours at room temperature or in boiling water for 2 hours.
After immersion for a time, no change was observed in the optical performance.
A durability test similar to that of Example 1 was performed, and similarly, excellent performance was shown.

Example 3 Chromium was reactively sputtered on a glass substrate in the same manner as in Example 1 to form chromium nitride (first layer) of about 10 °.
The mixture was switched to a mixed gas of argon and oxygen to 2 × 10 ⁻³ Torr. Next, a target containing ZrB ₂ and SiC is reactively sputtered to form an oxide film (second layer) containing Zr, B, and Si for about 20 minutes.
0 ° formed.

The optical performance T _V , T _E , R _VF , R _VG ,
The color changes of the transmitted color and the reflected color are 72, 58, 10, 9 respectively.
(%), 0.0074 and 0.029. The transmitted color and the reflected color were almost indistinguishable from the bare plate. Example 1 for durability
It was very good as well.

Example 4 Instead of the titanium nitride of Example 1, chromium, titanium, and zirconium were each formed as a first layer by about 10 °.
Reactive sputtering of ZrB ₂ target on top
An oxide film (second layer) containing B and B was formed at about 200 ° to produce three types of heat-shielding glasses. These T _V , T _E , R _VF , R _VG
No significant difference was observed in chromium, titanium, and zirconium of the first layer, which were 72, 58, 11, and 10 (%), respectively. The color change of the transmitted color and the reflected color is 0.0031 to 0, respectively.
0065, 0.028 to 0.030, which were extremely excellent as in Example 1. The durability was extremely excellent as in Example 1.

Example 5 In the same manner as in Example 1, after forming titanium nitride at 20 °, tin was reactively sputtered to form 200 °. T _V , T _E , R _VF , R _VG of the thus obtained heat shielding glass are 70, respectively.
55, 15, and 13 (%).

The membrane was excellent in durability except that the solution of the membrane was observed after being stored in a 0.1 N hydrochloric acid aqueous solution for a long time. Except that the color tone is slightly higher in reflection, the color change of the transmitted color and the reflected color is 0.00
36, 0.030 and neutral color.

Example 6 In the same manner as in Example 1, titanium nitride was formed at a thickness of 20 [deg.], And silicon oxide was formed at 250 [deg.] By high frequency reactive sputtering. T _V , T _E , R _VF , R
_VG was 73, 56, 8, and 6 (%), respectively.

The durability was excellent except that the film was dissolved in a 0.1 N aqueous sodium hydroxide solution for a long time. The reflectance was low, and the color tone change of the transmitted color and the reflected color was 0.005 and 0.018, which was extremely excellent.

Example 7 In the same manner as in Example 1, after forming titanium nitride by 20 °, a zirconium-boron alloy target (composition: 50Zr-atomic concentration)
50B) was reactively sputtered to form an oxide film (second layer) composed of Zr and B at about 200 °.

The optical performance T _V , T _E , R _VF ,
R _VG , transmissive color and reflected color change in color tone are 72.3 and 58.
5, 10.4, 8.8 (%), 0.0024, and 0.0290. The transmitted color and the reflected color were almost indistinguishable from the bare plate. To examine the durability of the film, the film was immersed in a 0.1 N aqueous solution of hydrochloric acid or sodium hydroxide for 240 hours at room temperature or for 2 hours in boiling water, but no change was observed in the optical performance. From this, it was found that a more durable durability test than Example 1 showed excellent durability. The rubbing test with a sand eraser also showed extremely good scratch resistance.

Example 8 In the same manner as in Example 1, after forming titanium nitride at 20 °, a ZrSi ₂ target was reactively sputtered to form an oxide film (second layer) composed of Zr and Si at about 200 °.

The optical performance T _V , T _E , R _VF ,
The color tone changes of R _VG , transmission color and reflection color are 73.7 and 59.
3, 8.6, 7.1 (%), 0.0010, 0.0175. The durability of the film was evaluated under the same conditions as in Example 7, but also showed excellent performance.

Example 9 A titanium zirconium-silicon alloy target (atomic concentration of 10Zr-
90Si) was reactively sputtered to form an oxide film (second layer) composed of Zr and Si with a thickness of about 200 °.

The optical performance T _V , T _E , R _VF ,
The color tone changes of R _VG , transmission color and reflection color are 74.3 and 59.
It was 6, 8.0, 6.3 (%), 0.0008, 0.0074. The durability of the film was evaluated under the same conditions as in Example 7, but also showed excellent performance.

[Effects of the Invention] The heat ray blocking glass of the present invention has a heat ray absorbing film on a transparent substrate,
Since it has a film configuration of two or more layers in which a specific oxide film having a refractive index of 2.0 or less is laminated, it has a natural, neutral color tone, a high visible light transmittance, and high durability. Therefore, it can be used satisfactorily in applications where the use environment is severe, such as for construction and automobiles.

When an oxide film containing one or more of B or Si and Zr is formed as the oxide film 3, a heat ray shielding glass having particularly excellent wear resistance and chemical resistance can be obtained.

By increasing the content ratio of B or Si or the total amount thereof, the refractive index of the oxide film can be reduced to 1.7 or less, and as a result, visible light low reflection, high transmission, and heat ray blocking having a neutral color tone Glass becomes possible.

Further, when an oxide film containing one or more of B or Si and Zr is used as the air-side outermost layer 3, the film can be formed by a DC sputtering method, and therefore, for an automobile requiring a large area, Ideal for applications such as construction.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of the heat ray shielding glass of the present invention. FIG. 2A shows the content of B in the ZrB _x O _y film and the refractive index n of the film.
FIG. FIG. 2 (b) is a diagram showing the relationship between the content of Si in the ZrSi _z O _y film and n. FIG. 2 (c) is a diagram showing the relationship between the content of Si in the ZrB ₁ Si _z O _y film and n. FIG. 2 (d) is a diagram showing the relationship between the content of Si in the TiSi _z O _y film and n. 1: glass substrate, 2: heat ray absorbing film, 3: oxide film.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location G02B 5/20 G02B 5/20

Claims (6)

(57) [Claims] 1. A heat-shielding glass in which at least two layers of a heat-ray absorbing film and an oxide film are sequentially laminated on a glass substrate, wherein the oxide film is the outermost layer on the air side and has a refractive index of 2.0 or less. ZrB _y O _y film (1.0 ≦ x <2.3, 2.5 ≦ y <5.4
5) A heat ray shielding glass, characterized in that: 2. A heat-shielding glass in which at least two layers of a heat ray absorbing film and an oxide film are sequentially laminated on a glass substrate, wherein the oxide film is the outermost layer on the air side and has a refractive index of 2.0 or less. ZrSi _z O _y film (0.28 ≦ z <19, 2.56 ≦ y <4
0) A heat ray shielding glass, which is characterized in that: 3. A heat-shielding glass in which at least two layers of a heat-absorbing film and an oxide film are sequentially laminated on a glass substrate, wherein the oxide film is the outermost layer on the air side and has a refractive index of 2.0 or less. ZrB _x Si _z O _y film (0.28 ≦ x + z <19, 2.5 ≦
y <40 except for x + z−3> 0 and x−3z + 1> 0). 4. A heat ray blocking glass in which at least two layers of a heat ray absorbing film and an oxide film are sequentially laminated on a glass substrate, wherein the oxide film is the outermost layer on the air side and has a refractive index of 2.0 or less. A heat-shielding glass, characterized in that the film is a TiSi _z O _y film (z ≧ 0.56, y = 2 + 2z) having the following formula: 5. The heat ray blocking glass according to claim 1, wherein the visible light transmittance is 70% or more. 6. A heat ray absorbing film comprising titanium, chromium, zirconium, tantalum, hafnium, titanium nitride, chromium nitride,
The heat ray shielding glass according to any one of claims 1 to 5, wherein one or two or more selected from the group consisting of zirconium nitride, tantalum nitride, and hafnium nitride are used as main components.