JPH048382B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a heat-resistant ultraviolet-transmitting heat-absorbing glass made of borosilicate glass that transmits ultraviolet rays with a wavelength of 254 nm and absorbs visible and infrared rays. [Technical background of the invention and its problems] Conventionally, a mercury lamp is used to cure ultraviolet curable resins, etc. by irradiating ultraviolet rays, but the temperature of the object to be irradiated increases due to the infrared rays and radiant heat from the light source. Rise. For this reason, when curing a resin film or the like that is not heat resistant, a jacket tube made of mercury or the like is formed with a double tube body, and cold water is introduced into the space to remove the radiant heat. However, this water-cooling method requires large and complicated equipment, so recently there has been an increase in
A convenient method is to install a glass filter that transmits 254 nm ultraviolet rays well and absorbs heat rays to block infrared rays and radiant heat. However, applied to this glass filter
Phosphate glass is used as a glass that transmits 254 nm ultraviolet rays and absorbs visible and infrared rays, but it has poor weather resistance and has the disadvantage that the surface deteriorates and the ultraviolet transmittance decreases dramatically after long-term use. be. In addition, a glass filter made of silicate glass that transmits 254 nm ultraviolet rays has low heat resistance, so if the device is miniaturized using a high-pressure mercury lamp, it will be damaged by heat. [Object of the invention] The present invention has been made in consideration of the above circumstances, and
The purpose of the present invention is to provide an ultraviolet-transmitting and heat-absorbing glass that transmits 254 nm ultraviolet rays, absorbs visible and infrared rays, and has excellent heat resistance. [Summary of the Invention] The present invention provides SiO ₂ 60-75% by weight percentage;
_{B2O3 16-25} %, _{Al2O3 1-5} %, _Na2O1-10 %,
_K2O0 ~5%, _Li2O0 ~2%, _Na2O + _K2O +
_Li2O2 ~10%, CaO0~5%, MgO0~2%,
ZnO0~5%, CaO+MgO+ZnO0.1~8%,
Contains 0.1-2% NiO and 0.5-4% CoO,
The average coefficient of thermal expansion at 0 to 300℃ is 70×10 ^-7 /
It is an ultraviolet transmitting and heat absorbing glass that is below ℃. Next, the reason for limiting the values of each component of the glass will be described. SiO ₂ is the main component forming glass, but 75
If it exceeds 60%, the meltability will deteriorate, and if it is less than 60%, the heat resistance will decrease. When B ₂ O ₃ exceeds 25%, weather resistance decreases and phase separation tends to occur, and when it is less than 16%, meltability and moldability deteriorate, and transmittance at 254 nm decreases. When Al ₂ O ₃ exceeds 5%, unmelted substances tend to occur, and when it is less than 1%, there is no effect of improving weather resistance. Na ₂ O, K ₂ O, and Li ₂ O can improve meltability without deteriorating weather resistance within the desired range of thermal expansion coefficient, but if their total amount exceeds 10%, the thermal expansion coefficient will decrease. If it is less than 2%, the viscosity increases and the meltability deteriorates. CaO, MgO, and ZnO are effective in improving meltability, but if their total amount exceeds 8%, meltability deteriorates. NiO and CoO are used together to absorb heat rays, but if the upper limit of each is exceeded, the transmittance of ultraviolet rays at 254 nm decreases, and if it is less than the lower limit, there is no effect of absorbing heat rays. In addition, in order to obtain the desired heat resistance, this glass
The average coefficient of thermal expansion at 0 to 300℃ is 70×10 ^-7 /
Limited to below ℃. [Examples of the Invention] Examples of glass filters made of the glass of the invention are shown in the following table. In the table, the glass composition is shown in weight percentage, and No. 3 shows a comparative example of silicate glass and No. 4 shows a comparative example of phosphate glass. Furthermore, heat resistance is indicated by the breakage rate when the temperature of the glass is rapidly raised from room temperature to 400°C5 in 2 minutes, and the transmittance at 254 nm indicates the transmittance in a glass filter with a wall thickness of 2.5 mm.

【table】

〔Effect of the invention〕

As described above, the present invention is a borosilicate glass that transmits 254 nm ultraviolet rays and absorbs visible and infrared rays, and has superior heat resistance compared to conventional phosphate glasses and silicate glasses. It has the effect of being able to downsize the device by applying it to a glass filter, etc. of the device.

Claims (1)

[Claims] 1 SiO ₂ 60-75%, B ₂ O ₃ 16-25% by weight percentage,
Al ₂ O ₃ 1-5%, Na ₂ O 1-10%, K ₂ O 0-5%,
Li ₂ O 0 ~ 2%, Na ₂ O + K ₂ O + Li ₂ O 2 ~ 10%,
CaO0~5%, MgO0~2%, ZnO0~5%, CaO
+MgO+ZnO0.1~8%, NiO0.1~2%, CoO0.5
An ultraviolet transmitting and heat ray absorbing glass containing a component of ~4% and having an average coefficient of thermal expansion of 70×10 ^-7 /°C or less at 0 to 300°C.