阅读说明：本技术 近红外线吸收玻璃 (Near infrared ray absorption glass ) 是由 永野雄太 村田哲哉 高山佳久 于 2018-07-30 设计创作，主要内容包括：本发明提供一种近红外线吸收玻璃,其能够使光学装置薄型化,并且即使在不含氟的情况下,耐候性、耐失透性和光学特性的各特性也优异。该近红外线吸收玻璃的特征在于,以质量％计,含有P<Sub>2</Sub>O<Sub>5</Sub> 20～80％、RO(其中,R为选自Mg、Ca、Sr和Ba中的至少一种)1～50％、MgO 0.1～30％、Na<Sub>2</Sub>O 0～15％、K<Sub>2</Sub>O 0以上且小于14％、和CuO 0.1～30％,上述近红外线吸收玻璃的厚度在0.25mm以下。(The invention provides a near infrared ray absorbing glass which can make an optical device thin and has excellent weather resistance, devitrification resistance and optical characteristics even under the condition of not containing fluorine. The near infrared ray absorption glass is characterized by containing P by mass percent 2 O 5 20-80%, RO (wherein R is at least one selected from Mg, Ca, Sr and Ba) 1-50%, MgO 0.1-30%, Na 2 O 0～15％、K 2 O0 to less than 14%,And CuO 0.1-30%, and the thickness of the near infrared ray absorption glass is less than 0.25 mm.)

1. A near-infrared absorbing glass characterized in that,

contains P in mass%₂O₅ 20～80％、RO 1～50％、MgO 0.1～30％、Na₂O 0～15％、K₂O0 or more and less than 14%, and CuO 0.1 to 30%, wherein R is at least one selected from Mg, Ca, Sr and Ba,

the thickness of the near infrared ray absorbing glass is less than 0.25 mm.

2. The near-infrared ray absorption glass according to claim 1,

further contains Al in mass%₂O₃ 0～19％、ZnO 0～13％。

3. The near-infrared ray absorption glass according to claim 1 or 2,

the near-infrared absorbing glass contains no fluorine component.

Technical Field

The present invention relates to a near-infrared-absorbing glass capable of selectively absorbing near-infrared rays.

Background

In general, near infrared absorbing glass is used in a camera portion of an optical device such as a digital camera or a smartphone to correct visibility of a solid-state image pickup element such as a CCD or a CMOS. For example, patent document 1 discloses a fluorine-containing phosphoric acid-based near-infrared absorbing glass. Since fluorine has a high effect of improving weather resistance, the near-infrared absorbing glass described in patent document 1 has excellent weather resistance.

Disclosure of Invention

Technical problem to be solved by the invention

Since the fluorine component is an environmentally-friendly substance, its use has been limited in recent years. However, when the fluorine component is not contained, it is difficult to improve the weather resistance, and when the weather resistance is improved, defects such as devitrification resistance and deterioration of optical properties are likely to occur. In addition, in recent years, there has been a strong demand for thinning of optical devices, and there is a demand for thinning of near-infrared ray absorbing glass, but higher resistance to devitrification is required in the case of manufacturing thin near-infrared ray absorbing glass.

In view of the above circumstances, an object of the present invention is to provide a near-infrared absorbing glass which can make an optical device thin and is excellent in various properties of weather resistance, devitrification resistance and optical properties even when it does not contain fluorine.

Technical solution for solving technical problem

The near-infrared absorbing glass of the present invention is characterized by containing P in mass%₂O₅20-80% of RO (wherein R is selected from Mg, Ca, Sr)And at least one of Ba) 1 to 50%, MgO 0.1 to 30%, and Na₂O 0～15％、K₂O0 or more and less than 14%, and CuO 0.1 to 30%, and the near-infrared absorbing glass has a thickness of 0.25mm or less.

In the near-infrared absorbing glass of the present invention, RO for improving devitrification resistance is defined to be 1% or more, and Na for reducing devitrification resistance₂O is 15% or less, and K is₂O is specified to be less than 14%, thereby achieving high devitrification resistance. Therefore, the method is also applicable to a forming method which is easily accompanied by devitrification, such as a down-draw method and a multi-stage drawing method, which can efficiently produce infrared absorbing glass having a small thickness.

The near-infrared absorbing glass of the present invention preferably further contains Al in mass%₂O₃ 0～19％、ZnO 0～13％。

The near-infrared absorbing glass of the present invention preferably contains no fluorine component. Here, "containing no fluorine component" means that the inclusion is not intended, and the incorporation of inevitable impurities is not excluded. Specifically, the fluorine content is 1000ppm or less.

Effects of the invention

The present invention provides a near-infrared absorbing glass which can be made thinner in an optical device and is excellent in various properties such as weather resistance, devitrification resistance, and optical properties even when it does not contain fluorine.

Detailed Description

The near-infrared absorbing glass of the present invention comprises: p₂O₅20-80%, RO (wherein R is at least one selected from Mg, Ca, Sr and Ba) 1-50%, MgO 0.1-30%, Na₂O 0～15％、K₂O0 or more and less than 14%, and CuO 0.1 to 30%. The reason why the glass composition is limited as described above will be described below. In the following description of the content of each component, "%" means "% by mass" unless otherwise specified.

P₂O₅Is an indispensable component for forming a glass skeleton. P₂O₅The content of (b) is 20 to 80%, preferably 31 to 73%, and particularly preferably 45 to 67%.At P₂O₅When the content of (b) is too small, the vitrification tends to become unstable. On the other hand, in P₂O₅When the content (b) is too large, the viscosity of the liquid phase becomes low, and the resistance to devitrification and weather resistance are liable to be lowered.

RO (wherein R is at least one selected from the group consisting of Mg, Ca, Sr and Ba) is a component for improving resistance to devitrification and weather resistance. The content of RO is 1 to 50%, preferably 3 to 34%, and particularly preferably 6 to 20% in total. When the RO content is too small, the above-mentioned effects are hardly obtained. On the other hand, if the RO content is too high, devitrification resistance is lowered, and crystals due to the RO component are likely to precipitate.

Among these, preferable ranges of the content of each component of RO are as follows.

MgO is a component for improving resistance to devitrification and weather resistance. The content of MgO is preferably 0.1 to 30%, particularly preferably 0.4 to 13%. When the content of MgO is too small, it is difficult to obtain the above-mentioned effects. On the other hand, when the content of MgO is too large, the vitrification stability is liable to be lowered.

CaO is a component for improving resistance to devitrification and weather resistance, similarly to MgO. The content of CaO is preferably 0 to 15%, and particularly preferably 0.4 to 7%. When the content of CaO is too large, the vitrification stability is liable to be lowered.

Like MgO, SrO is also a component for improving resistance to devitrification and weather resistance. The content of SrO is preferably 0 to 12%, and particularly preferably 0.3 to 6%. When the SrO content is too large, the vitrification stability is liable to be lowered.

BaO is also a component for improving resistance to devitrification and weather resistance, similarly to MgO. The content of BaO is 0 to 30%, preferably 1 to 25%, and particularly preferably 3 to 20%. When the content of BaO is too large, crystals due to BaO are likely to precipitate during molding.

As described above, RO has an effect of improving resistance to devitrification, particularly in P₂O₅In a small number of cases, the effects thereof are easily enjoyed.

Na₂O is a component for lowering the melting temperature. Na (Na)₂The content of O is 0 to 15%, and particularly preferably 0.1 to 10%. In Na₂When the content of O is too large, devitrification resistance is exhibitedThe tendency to decrease sex.

K₂O is also bound to Na₂O is also a component for lowering the melting temperature. K₂The content of O is 0 to less than 14%, and particularly preferably 0.1 to 12%. At K₂When the content of O is too large, K is likely to precipitate during molding₂The crystal formation by O tends to lower the devitrification resistance.

CuO is an essential component for absorbing near infrared rays. The content of CuO is 0.1 to 30%, preferably 0.3 to 20%, preferably 2 to 15%, and particularly preferably 3 to 13%. When the content of CuO is too small, it is difficult to obtain desired near-infrared absorption characteristics. On the other hand, if the CuO content is too large, the light transmittance in the ultraviolet to visible region tends to decrease. There is also a tendency that the devitrification resistance is lowered.

In addition to the above components, various components shown below may be contained.

Al₂O₃Is a component for improving weather resistance, liquid phase viscosity and devitrification resistance. Al (Al)₂O₃The content of (b) is 0 to 19%, preferably 2 to 19%, preferably 3 to 14%, and particularly preferably 3 to 9%. In Al₂O₃When the content of (b) is too large, the meltability tends to be low and the melting temperature tends to be high. Further, once the melting temperature is increased, Cu ions are easily reduced from Cu²⁺Conversion to Cu⁺And thus it is difficult to obtain desired optical characteristics. Specifically, the light transmittance in the near ultraviolet to visible region is likely to decrease, or the near infrared absorption characteristic is likely to decrease.

ZnO is a component for improving resistance to devitrification and weather resistance. The content of ZnO is 0 to 13%, preferably 0.1 to 12%, and particularly preferably 1 to 10%. When the content of ZnO is too large, the meltability decreases and the melting temperature increases, and as a result, it is difficult to obtain desired optical characteristics. In addition, crystals due to ZnO are likely to precipitate during molding, and the devitrification resistance tends to decrease.

Li₂O is a component for lowering the melting temperature. Li₂The content of O is 0 to 15%, and particularly preferably 0.1 to 10%. In Li₂When the content of O is too large, the devitrification resistance tends to be lowered。

In addition, in addition to the above components, B may be contained within a range not impairing the effects of the present invention₂O₃、Nb₂O₅、Y₂O₃、La₂O₃、Ta₂O₅、CeO₂、Sb₂O₃And the like. Specifically, the content of each of these components is preferably 0 to 3%, and particularly preferably 0 to 2%. Further, the fluorine component is preferably not contained because it is an environmentally-friendly substance.

The near-infrared absorbing glass of the present invention is generally used in a plate shape. The thickness is 0.25mm or less, preferably 0.2mm or less, preferably 0.15mm or less, and particularly preferably 0.1mm or less. If the thickness is too large, it becomes difficult to make the optical device thin. The lower limit of the thickness is not particularly limited, but is preferably 0.01mm or more from the viewpoint of mechanical strength.

The near-infrared-absorbing glass of the present invention having the above composition can achieve both high light transmittance in the visible region and excellent light absorption characteristics in the near-infrared region. Specifically, the light transmittance at a wavelength of 500nm is preferably 75% or more, particularly preferably 77% or more. On the other hand, the light transmittance at a wavelength of 700nm is preferably 30% or less, particularly preferably 28% or less, and the light transmittance at a wavelength of 1200nm is preferably 40% or less, particularly preferably 38% or less.

The near-infrared ray-absorbing glass of the present invention preferably has a liquid phase viscosity of 10^1.6dPa · s or more, particularly preferably 10^1.9dPas or more. When the liquid phase viscosity is too low, devitrification is likely to occur during molding.

The near-infrared absorbing glass of the present invention can be produced by melting and molding a raw material powder masterbatch prepared with a desired composition. The melting temperature is preferably 900 to 1200 ℃. When the melting temperature is too low, it is difficult to obtain homogeneous glass. On the other hand, when the melting temperature is too high, Cu ions are easily reduced from Cu²⁺Conversion to Cu⁺And thus it is difficult to obtain desired optical characteristics.

Then, the molten glass is molded into a predetermined shape, and subjected to necessary post-processing for various uses. In addition, in order to efficiently produce a near-infrared-absorbing glass having a small thickness, a forming method such as a down-draw method or a multi-stage drawing method is preferably applied. These molding methods are likely to involve devitrification, and therefore, the near infrared ray absorption glass of the present invention having excellent devitrification resistance is likely to enjoy the effect thereof.