Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/12—Silica-free oxide glass compositions
  • C03C3/16—Silica-free oxide glass compositions containing phosphorus
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/12—Silica-free oxide glass compositions
  • C03C3/16—Silica-free oxide glass compositions containing phosphorus
  • C03C3/17—Silica-free oxide glass compositions containing phosphorus containing aluminium or beryllium
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C4/00—Compositions for glass with special properties
  • C03C4/08—Compositions for glass with special properties for glass selectively absorbing radiation of specified wave lengths
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/20—Filters
  • G02B5/22—Absorbing filters
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/20—Filters
  • G02B5/22—Absorbing filters
  • G02B5/226—Glass filters

Definitions

• the present invention relates to a near-infrared absorbing glass capable of selectively absorbing near-infrared light.
• near-infrared absorbing glass is used for camera parts in optical devices such as digital cameras and smartphones for the purpose of correcting the visibility of solid-state imaging devices such as CCDs and CMOS.
• Patent Document 1 discloses a phosphate-based near-infrared absorbing glass containing fluorine. Since the fluorine is highly effective in improving the weather resistance, the near-infrared absorbing glass described in Patent Document 1 is excellent in the weather resistance.
• the fluorine component is an environmentally harmful substance, its use has recently been limited. However, when the fluorine component is not contained, it is difficult to improve the weather resistance, and when it is intended to improve the weather resistance, problems such as a decrease in devitrification resistance and optical characteristics tend to occur. In recent years, it has been strongly desired to reduce the thickness of optical devices, and it is necessary to reduce the thickness of near-infrared absorbing glass. However, higher devitrification resistance is required to produce thin near-infrared absorbing glass.
• the present invention provides a near-infrared absorbing glass excellent in various characteristics of weatherability, devitrification resistance and optical properties, even if the optical device can be thinned and fluorine is not contained.
• the purpose is
• the near-infrared absorbing glass of the present invention contains, in mass%, 20 to 80% of P 2 O 5 , RO (wherein R is at least one selected from Mg, Ca, Sr, and Ba) 1 to 50%, MgO 0. It is characterized by containing 1 to 30%, 0 to 15% Na 2 O, 0 to less than 14% K 2 O, and 0.1 to 30% CuO, and having a thickness of 0.25 mm or less.
• the near-infrared absorbing glass of the present invention regulates the RO to improve the devitrification resistance to 1% or more, the Na 2 O to reduce the devitrification resistance to 15% or less, and the K 2 O to less than 14%. High devitrification resistance is achieved. Therefore, it can apply also to the forming method which tends to be accompanied by devitrification, such as the down draw method which can manufacture efficiently infrared absorption glass with small thickness, and a redraw method.
• the near-infrared absorbing glass of the present invention preferably further contains, by mass%, 0 to 19% of Al 2 O 3 and 0 to 13% of ZnO.
• the near-infrared absorption glass of this invention does not contain a fluorine component.
• does not contain a fluorine component means that it is not intentionally contained, and does not exclude the mixing of unavoidable impurities. Specifically, it means that the content of the fluorine component is 1000 ppm or less.
• the present invention it is possible to provide a near-infrared absorbing glass excellent in each of weather resistance, devitrification resistance, and optical characteristics, even if the optical device can be thinned and no fluorine is contained. It becomes possible.
• the near-infrared absorbing glass of the present invention is P 2 O 5 20 to 80%, RO (wherein R is at least one selected from Mg, Ca, Sr and Ba) 1 to 50%, MgO 0.1 to 30% , 0 to 15% Na 2 O, 0 to less than 14% K 2 O, and 0.1 to 30% CuO.
• R is at least one selected from Mg, Ca, Sr and Ba
• MgO 0.1 to 30% 0 to 15% Na 2 O, 0 to less than 14% K 2 O, and 0.1 to 30% CuO.
• P 2 O 5 is an essential component to form a glass skeleton.
• the content of P 2 O 5 is 20 to 80%, preferably 31 to 73%, and more preferably 45 to 67%.
• vitrification tends to be unstable.
• the content of P 2 O 5 is too large, the liquid phase viscosity is lowered, the devitrification resistance is lowered, and the weather resistance is easily lowered.
• RO (wherein R is at least one selected from Mg, Ca, Sr and Ba) is a component that improves the devitrification resistance and the weather resistance.
• the total content of RO is 1 to 50%, preferably 3 to 34%, and more preferably 6 to 20%.
• the content of RO is too small, the above effect is hardly obtained.
• the content of RO is too large, the devitrification resistance is lowered and crystals due to the RO component are easily precipitated.
• the preferable range of content of each component of RO is as follows.
• MgO is a component that improves the devitrification resistance and the weather resistance.
• the content of MgO is preferably 0.1 to 30%, and more preferably 0.4 to 13%. When the content of MgO is too small, the above effect is hardly obtained. On the other hand, when the content of MgO is too large, the stability of vitrification tends to be reduced.
• CaO is a component that improves the devitrification resistance and the weather resistance.
• the content of CaO is preferably 0 to 15%, especially 0.4 to 7%. When the content of CaO is too large, the stability of vitrification tends to be reduced.
• SrO is also a component that improves the devitrification resistance and the weather resistance as well as MgO.
• the content of SrO is preferably 0 to 12%, particularly 0.3 to 6%. When the content of SrO is too large, the stability of vitrification tends to be reduced.
• BaO is also a component that improves the devitrification resistance and the weather resistance.
• the content of BaO is preferably 0 to 30%, 1 to 25%, particularly 3 to 20%. When the content of BaO is too large, crystals derived from BaO are easily precipitated during molding.
• RO has an effect of improving the devitrification resistance, and in particular, when P 2 O 5 is small, it is easy to receive the effect.
• Na 2 O is a component that lowers the melting temperature.
• the content of Na 2 O is 0 to 15%, preferably 0.1 to 10%. When the content of Na 2 O is too large, the devitrification resistance tends to be reduced.
• K 2 O is also a component that lowers the melting temperature, similarly to Na 2 O.
• the content of K 2 O is from 0 to less than 14%, particularly preferably from 0.1 to 12%. If the content of K 2 O is too large, crystals derived from K 2 O tend to be precipitated during molding, and the devitrification resistance tends to decrease.
• CuO is an essential component for absorbing near infrared rays.
• the content of CuO is preferably 0.1 to 30%, 0.3 to 20%, 2 to 15%, particularly 3 to 13%. If the content of CuO is too low, it is difficult to obtain desired near infrared absorption characteristics. On the other hand, when the content of CuO is too large, the light transmittance in the ultraviolet to visible region is likely to decrease. In addition, the devitrification resistance tends to decrease.
• Al 2 O 3 is a component that improves the weather resistance, increases the liquidus viscosity, and improves the devitrification resistance.
• the content of Al 2 O 3 is preferably 0 to 19%, 2 to 19%, 3 to 14%, particularly 3 to 9%. If the content of Al 2 O 3 is too large, the meltability tends to decrease and the melt temperature tends to rise. Note that, when the melting temperature rises, Cu ions are reduced and it is easy to shift from Cu 2+ to Cu + , so it is difficult to obtain desired optical characteristics. Specifically, the light transmittance in the near ultraviolet to visible region is likely to be reduced, and the near infrared absorption characteristics are likely to be degraded.
• ZnO is a component that improves the devitrification resistance and the weather resistance.
• the content of ZnO is preferably 0 to 13%, 0.1 to 12%, and particularly 1 to 10%.
• the meltability is lowered and the melt temperature is increased, as a result, it becomes difficult to obtain desired optical characteristics.
• crystals derived from ZnO tend to be precipitated during molding, and the devitrification resistance tends to decrease.
• Li 2 O is a component that lowers the melting temperature.
• the content of Li 2 O is 0 to 15%, preferably 0.1 to 10%. When the content of Li 2 O is too large, the devitrification resistance tends to decrease.
• B 2 O 3 , Nb 2 O 5 , Y 2 O 3 , La 2 O 3 , Ta 2 O 5 , CeO 2 , Sb 2 O 3 and the like may be used within the scope of the present invention. It may be contained in Specifically, the content of each of these components is preferably 0 to 3%, particularly 0 to 2%. In addition, since it is an environmentally harmful substance, it is preferable not to contain a fluorine component.
• the near-infrared absorbing glass of the present invention is usually used in the form of a plate.
• the thickness is 0.25 mm or less, preferably 0.2 mm or less, 0.15 mm or less, and particularly 0.1 mm or less. If the thickness is too large, thinning of the optical device becomes difficult.
• the lower limit of the thickness is not particularly limited, but is preferably 0.01 mm or more from the viewpoint of mechanical strength.
• the near-infrared absorbing glass of the present invention can achieve both high light transmittance in the visible region and excellent light-absorbing characteristics in the near-infrared region.
• the light transmittance at a wavelength of 500 nm is preferably 75% or more, and particularly preferably 77% or more.
• the light transmittance at a wavelength of 700 nm is preferably 30% or less, particularly preferably 28% or less, and the light transmittance at a wavelength of 1200 nm is preferably 40% or less, particularly preferably 38% or less.
• the liquidus viscosity of the near-infrared absorbing glass of the present invention is preferably 10 1.6 dPa ⁇ s or more, and more preferably 10 1.9 dPa ⁇ s or more. If the liquidus viscosity is too low, devitrification tends to occur during molding.
• the near-infrared absorbing glass of the present invention can be produced by melting and shaping a raw material powder batch prepared to have a desired composition.
• the melting temperature is preferably 900 to 1200 ° C. When the melting temperature is too low, it is difficult to obtain a homogeneous glass. On the other hand, if the melting temperature is too high, Cu ions are reduced and it is easy to shift from Cu 2+ to Cu + , so it is difficult to obtain desired optical characteristics.
• the molten glass can be formed into a predetermined shape, subjected to necessary post-processing, and used for various applications.
• molding methods such as the down draw method and the redraw method. Since these forming methods are likely to be accompanied by devitrification, it is easy to enjoy the effect of the near-infrared absorbing glass of the present invention which is excellent in devitrification resistance.
• Table 1 shows Examples (Sample Nos. 1 to 8) and Comparative Examples (Sample Nos. 9 and 10) of the present invention.
• the light transmission characteristics of each of the samples of the thickness described in Table 1 mirror-polished on both sides were measured with respective transmittances at wavelengths of 500 nm, 700 nm, and 1200 nm using a spectral analyzer (UV3100 manufactured by Shimadzu Corporation). If the transmittances at wavelengths of 500 nm, 700 nm, and 1200 nm are 77% or more, 28% or less, and 38% or less, respectively, it can be determined that the light transmission characteristics are good.
• the weather resistance of the sample mirror-polished on both sides was determined under the conditions of a temperature of 120 ° C. and a relative humidity of 100% for 24 hours, and then judged by the presence or absence of a change in appearance. Specifically, those in which no change in appearance was observed after the test were evaluated as “ ⁇ ”, and those in which changes in appearance such as white discoloration were observed were evaluated as “x”.
• the liquid phase viscosity was determined as follows. The sample crushed to a particle size of 300 to 600 ⁇ m was placed in a platinum container and kept in a temperature gradient furnace for 24 hours. The maximum temperature at which interfacial crystals were deposited on the bottom of the platinum container was taken as the liquidus temperature. The viscosity of the sample was then measured, and the viscosity at the liquidus temperature was taken as the liquidus viscosity.
• No. 1 which is an embodiment of the present invention.
• Samples 1 to 8 had high light transmittance in the visible region and large absorption in the near infrared region.
• the liquid phase viscosity was 10 1.6 dPa ⁇ s or more, and the devitrification resistance was also excellent.
• thickness is 0.23 mm or less, it is easy to make an optical device thin.
• No. 1 which is a comparative example.
• the sample No. 9 was inferior in weather resistance and inferior in devitrification resistance because the liquidus viscosity was 10 1.2 dPa ⁇ s.
• No. Sample No. 10 was inferior in devitrification resistance because the liquidus viscosity was 10 1.3 dPa ⁇ s.

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• Chemical & Material Sciences (AREA)
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• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
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• 2017
  • 2017-08-25 JP JP2017161910A patent/JP7071608B2/ja active Active
• 2018
  • 2018-05-22 TW TW107117336A patent/TWI704117B/zh active
  • 2018-07-30 KR KR1020197031984A patent/KR20200043310A/ko not_active Application Discontinuation
  • 2018-07-30 WO PCT/JP2018/028477 patent/WO2019039202A1/ja active Application Filing
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