JPH0672739A - Infrared ray absorbing glass - Google Patents

Abstract

PURPOSE:To provide IR absorbing glass having high IR absorbing ability, transmitting only visible light and capable of absorbing UV as well as IR by specifying the compsn. of IR absorbing glass. CONSTITUTION:Glass having a compsn. consisting of, by weight, 35-65% P2O5, 3.0-21.0% CuO, 0-0.1% CoO, 0-8.0% Al2O3, 15-45% RO (CaO+ZnO+BaO) and 5-15% Sb2O3+As2O3 is prepd. and part of the Cu is deposited as metal colloid by regulating the oxidized-reduced state of the glass. This metal colloid CU deg. absorbs UV and Cu<2+> absorbs IR.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is 1000 to 3000 ° C.
The present invention relates to an infrared absorbing glass used for absorbing heat rays emitted from a high temperature light source of the above.

[0002]

2. Description of the Related Art Many types of infrared absorbing glass have been known as infrared absorbing glass for infrared filters, etc., but most of them are those to which absorption by Fe ²⁺ or Cu ²⁺ is applied. Because the absorption capacity is not enough,
It was necessary to exert the necessary infrared absorbing ability by increasing the thickness of the glass. In addition, many conventional infrared absorbing glasses transmit light having a wide wavelength range of 300 to 700 nm, and none of them have the property of transmitting only light near 500 nm.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and provides a novel infrared absorbing glass having a large infrared absorbing ability and a property of transmitting only light having a wavelength near 500 nm. It was made to provide.

[0004]

The infrared absorbing glass of the present invention completed in order to solve the above-mentioned problems has a P ₂ O ₅ : 35-65% by weight% and a CuO: 3.0-21.0% by weight. %,
_{CoO: 0~0.1%, Al 2 O} 3: 0~8.0%, RO
(CaO + ZnO + BaO): 15~45%, Sb 2 O 3
+ As ₂ O _3: has 5 to 15% of the composition, a part of Cu is deposited as a metal colloid by adjusting the redox state of the glass, the light transmittance of the thickness of 2 mm,
10% or less at a wavelength of 380 nm, 0.5% or less at 360 nm, 35 to 60% at 510 nm, 6
It is characterized by being 5% or less at 00 nm and 0.1% or less at 620 to 1300 nm.

The basic idea of the present invention is to greatly enhance the infrared absorption capacity by incorporating Cu ²⁺ having an absorption peak at about 800 nm into the glass, and to partly store Cu in the ultraviolet region. Metal colloid with absorption peak (C
By depositing as u ⁰ ), ultraviolet rays are also absorbed at the same time, and only light in the vicinity of 500 nm is transmitted.

The reason for limiting the numerical value of the glass composition in the present invention will be described below. First P ₂ O ₅ to 35% to 65%
The reason is that if the content is lower than this, the devitrification tendency during melting becomes large and vitrification becomes difficult, and conversely, if the content is higher than this, the water resistance of the glass decreases significantly, This is because it lacks intellectual value. CuO 3.0
The content of ˜21.0% means that if the content is lower than this, not only the infrared absorption capacity is lowered and the desired characteristics are not obtained, but also the amount of Cu ⁰ is reduced, so the ultraviolet absorption capacity is reduced. Also, the absorption capacity around 600 nm cannot be obtained. On the contrary, if the content is higher than this, the water resistance decreases, and Cu ions are metallized during melting to separate and settle, which may cause damage to the refractory in the furnace.
Although CoO is not an essential component, the content of CuO can be reduced by containing 0.1% or less.

The reason why Al ₂ O ₃ is set to 0 to 8.0% is that the melting property of the glass is significantly lowered when the content is higher than this. RO (CaO + ZnO + BaO)
The content of 15 to 45% is because if it is less than this, the water resistance is reduced, and if it is more than this, the meltability is significantly reduced. Addition of Al ₂ O ₃ contributes to the improvement of water resistance,
Even if it is 0, the water resistance can be secured by RO. Sb ₂ O ₃ + As ₂ O _{3 is set} to 5 to 15% because if the content is less than this, Cu ²⁺ in the glass becomes unstable and the value of Cu ²⁺ / Total Cu decreases and infrared This is because not only the absorption capacity is lowered, but also the fining property of the glass is lowered, and conversely, if the content ratio is increased more than this, there is no difference in the effect, which is disadvantageous in terms of economical efficiency and safety.

In the present invention, a part of Cu is deposited as a metal colloid (Cu ⁰ ) by adjusting the redox state of the glass having the above composition, and the light having a wavelength in the ultraviolet range is absorbed. The following can be considered as control means, and the influence of each means on the amount of metal colloids deposited is as follows. It should be noted that only can be controlled independently, but since ~ are related to each other, any one of them will affect other means.

Increasing the amount of oxidant in the raw material results in C
The value of u ²⁺ / Total Cu increases and the value of Cu ⁰ / Cu ²⁺ decreases. If the O ₂ concentration in the atmosphere of the melting furnace is increased, Cu ²⁺ / T
The value of total Cu increases, and at the same time, the value of Cu ⁰ / Cu ²⁺ also decreases. When the melting temperature is raised, the value of Cu ⁰ / Total Cu increases and the value of Cu ⁰ / Cu ²⁺ increases. When the melting time is lengthened, the value of Cu ⁰ / Total Cu increases and the value of Cu ⁰ / Cu ²⁺ increases. When Sb ₂ O ₃ + As ₂ O ₃ is increased, Cu ²⁺ / Tot
The value of al Cu increases and the value of Cu ⁰ / Cu ²⁺ decreases.

In the present invention, by combining the above-mentioned means for controlling the oxidation-reduction state, C in glass can be obtained.
By controlling the amounts of u ²⁺ and Cu ⁰ , the light transmittance at a thickness of 2 mm is 10% or less at a wavelength of 380 nm, 360 n
0.5% or less at m and 35 to 6 at 510 nm
0%, 5% or less at 600 nm, 620 to 1300
nm is 0.1% or less. As described above, the infrared absorbing glass of the present invention can absorb 99.5% or more of the infrared ray having a wavelength of 620 nm or more when the thickness is 2 mm, and 99.90% or more of the ultraviolet ray having a wavelength of 360 nm or less. It can absorb 5% or more.
Examples of the present invention will be shown below.

[0011]

EXAMPLE Glass raw materials were prepared so as to have the glass compositions shown in Table 1, put in a clay crucible and melted under a condition of O ₂ concentration of 21%. This melting condition is also shown in Table 1.

[0012]

[Table 1]

2 mm of the glass obtained as described above
As a result of polishing to the thickness of and measuring the light transmittance,
It became as shown in FIG. As can be seen from these transmittance curves, the glasses of Examples 1 to 6 of the present invention have a transmittance of 10% or less at a wavelength of 380 nm, 0.5% or less at 360 nm, 35 to 60% at 510 nm, 60.
The conditions of 5% or less at 0 nm and 0.1% or less at 620 to 1300 nm are satisfied, but since the glass of Comparative Example has a high melting temperature, the amount of Cu ⁰ deposited as a metal colloid becomes excessive, and The transmittance curves will be different.

[0014]

As described above in detail, the infrared absorbing glass of the present invention has a large infrared absorbing ability and can sufficiently absorb infrared rays without increasing the thickness as in the conventional case. Further, the infrared absorbing glass of the present invention is 500 n
Has the property of transmitting only visible light with a wavelength near m,
There is an advantage that it can absorb not only infrared rays but also ultraviolet rays.

[Brief description of drawings]

FIG. 1 is a graph showing a transmittance curve of glass of Example 1.

FIG. 2 is a graph showing a transmittance curve of the glass of Example 2.

FIG. 3 is a graph showing a transmittance curve of the glass of Example 3.

FIG. 4 is a graph showing a transmittance curve of the glass of Example 4.

5 is a graph showing a transmittance curve of glass of Example 5. FIG.

FIG. 6 is a graph showing a transmittance curve of the glass of Example 6.

FIG. 7 is a graph showing a transmittance curve of glass of a comparative example.

Claims (1)

[Claims] 1. P ₂ O ₅ : 35-65% by weight, Cu
O: 3.0-21.0%, CoO: 0-0.1%, Al _{2
O 3: 0~8.0%, RO (} CaO + ZnO + Ba
_{O): 15~45%, Sb 2} O 3 + As 2 O 3: 5~15%
And a portion of Cu is deposited as a metal colloid by adjusting the redox state of the glass, and the light transmittance at a thickness of 2 mm is 10% or less at a wavelength of 380 nm and 0.5% or less at a wavelength of 360 nm. 510
The infrared absorption glass is characterized in that it is 35 to 60% in nm, 5% or less in 600 nm, and 0.1% or less in 620 to 1300 nm.