JP7535181B2 - Optical glass, optical preforms, optical elements and optical instruments - Google Patents

Description

The present invention relates to optical glass, and in particular to optical glass, and optical preforms, optical elements, and optical instruments made of the optical glass.

Fluorophosphate optical glass is an optical glass with low refractive index and low light dispersion. It has a special relative partial dispersion and a negative refractive index temperature coefficient, which can effectively eliminate the secondary spectrum and improve the imaging quality of optical lenses. At the same time, the softening temperature of such glass is relatively low, and aspherical lenses can be molded by primary or secondary pressing. It is an excellent optical material used in the manufacture of high-end digital optical terminal products and high-end equipment. With the development of miniaturization and high performance of imaging optical system products, the demand for optical design of fluorophosphate optical glass is increasing. The weather resistance stability of fluorophosphate glass products in the conventional technology is relatively low, and the surface of the glass subjected to atmospheric erosion will produce altered layers such as "white spots" and "cloudiness". In addition, the refractive index of glass will cause temperature differences as the temperature changes greatly, and the change in refractive index especially when used in a high temperature environment will greatly reduce the imaging quality. For this reason, in fields such as photoelectric materials, the performance requirements for fluorophosphate optical glass, such as weather resistance and refractive index temperature coefficient, are increasing, and the demand is becoming more and more urgent.

The technical problem to be solved by the present invention is to provide an optical glass having a refractive index temperature coefficient (60-80° C.) of −5.0×10 ⁻⁶ /° C. or less and excellent weather resistance stability.

The technical solutions adopted in the present invention to solve the technical problems are as follows:
(1) An optical glass having the following cationic components, expressed in weight percent:
P5 ⁺ : 5.0-20.0%, Ba2 ⁺ : 56.0-73.0%, Al3 ⁺ : 7.0-18.0%, Sr2 ⁺ : 0.5-12.0%, Ca2 ⁺ : 0-5.0%, and the total content of Ca2 ⁺ + ^Ba2+ +Al3 ⁺ is 69.0-85.0%.
The anionic components are expressed in weight percentage and include the following: ^F- : 35.0-60.0%, ^O2- : 40.0-65.0%.
(2) The optical glass according to (1), wherein the cationic component further comprises, expressed in weight percent:
Mg ²⁺ : 0-3.0%, and/or Zn ²⁺ : 0-3.0%, and/or Ln ³⁺ : 0.1-8.0%, and/or Rn ⁺ : 0-5.0%, and/or Nb ⁵⁺ : 0-3.0%, and/or W ⁶⁺ : 0-3.0%, and/or Ti ⁴⁺ : 0-3.0%, and/or Zr ⁴⁺ : 0-3.0%, and/or Si ⁴⁺ : 0-3.0%, and/or B ³⁺ : 0-3.0%, where Rn ⁺ is one or more of Li ⁺ , Na ⁺ and K ⁺ , and Ln ³⁺ is one or more of La ³⁺ , Gd ³⁺ , Y ³⁺ and Yb ³⁺ .
(3) An optical glass having a cationic content, expressed in weight percent, of:
P ⁵⁺ : 5.0-20.0%, Ba ²⁺ : 56.0-73.0%, Al ³⁺ : 7.0-18.0%, Sr ²⁺ : 0.5-12.0%, Mg ²⁺ : 0-3.0%, Ca ²⁺ : 0-5.0%, Zn ²⁺ : 0-3.0%, Si ⁴⁺ : 0-3.0%, B ³⁺ : 0-3.0%, W ⁶⁺ : 0-3.0%, Zr ⁴⁺ : 0-3.0%, Ti ⁴⁺ : 0-3.0%, Ln ³⁺ : 0.1-8.0%, Rn ⁺ : 0-5.0%, Nb ⁵⁺ : 0-3.0%. The total content of Ca ²⁺ +Ba ²⁺ +Al ³⁺ is 69.0-85.0%, and Rn ⁺ is one or more of Li ⁺ , Na ⁺ , and K ⁺ ; Ln ³⁺ is one or more of La ³⁺ , Gd ³⁺ , Y ³⁺ , and Yb ³⁺ ;
The anion components are expressed in weight percentage and consist of the following: ^F- : 35.0-60.0%, ^O2- : 40.0-65.0%.
(4) An optical glass according to any one of (1) to (3):
P ⁵⁺ : 8.0-20.0%, preferably 8.0-18.0%, and/or Ba ²⁺ : 58.0-72.0%, preferably 59.6-71.0%, and/or Al ³⁺ : 8.5-16.0%, preferably 9-16.0%, and/or Sr ²⁺ : 1.0-12.0%, preferably 2.0-11.0%, and/or Mg ²⁺ : 0-2.0%, preferably 0-1.2%, and/or Ca ²⁺ : 0-3.0%, and/or Zn ²⁺ : 0-1.0%, preferably not contained, and/or Ln ³⁺ : 0.1-5.0%, preferably 0.1-3.0%, and/or Rn ⁺ : 0-3.0%, preferably 0-1.0%, more preferably not containing Rn ⁺ , and/or Nb ⁵⁺ : 0-1.0%, preferably none, and/or Si ⁴⁺ : 0-1.0%, preferably none, and/or B ³⁺ : 0-1.0%, preferably none, and/or W ⁶⁺ : 0-1.0%, preferably none, and/or Zr ⁴⁺ : 0-1.0%, preferably none, and/or Ti ⁴⁺ : 0-1.0%, preferably none.
(5) An optical glass according to any one of (1) to (3):
( ^Ca2 + +Ba2 ⁺ )/( ^Sr2 + +Mg2 ⁺ ) is 4.5 to 20.0, preferably ( ^Ca2 + +Ba2 ⁺ )/( ^Sr2 + +Mg2 ⁺ ) is 5.0 to 15.0, and more preferably ( ^Ca2 + +Ba2 ⁺ )/( ^Sr2+ +Mg2 ⁺ ) is 6.0 to 12.0.
(6) An optical glass according to any one of (1) to (3):
The ratio Al ³⁺ /Sr ²⁺ is 1.0 to 5.0, preferably the ratio Al ³⁺ /Sr ²⁺ is 1.1 to 4.0, more preferably the ratio Al ³⁺ /Sr ²⁺ is 1.1 to 2.5, and even more preferably the ratio Al ³⁺ /Sr ²⁺ is 1.1 to 2.0.
(7) An optical glass according to any one of (1) to (3):
( ^Ca2 + + ^Ba2 + +Al3 ⁺ )/Sr2 ⁺ is 5.6-20.0, preferably 7.0-18.0, more preferably ( ^Ca2 + + ^Ba2 + +Al3 ⁺ )/Sr2 ⁺ is 9.0-15.0.
(8) An optical glass according to any one of (1) to (3):
The total content of Ca ²⁺ +Ba ²⁺ +Al ³⁺ is 70.0 to 81.0%, and more preferably the total content of Ca ²⁺ +Ba ²⁺ +Al ³⁺ is 70.0 to 80.0%.
(9) An optical glass according to any one of (1) to (3):
Ln ³⁺ is Gd ³⁺ and/or Y ³⁺ , preferably Gd ³⁺ and/or Gd ³⁺ : 0.1 to 5.0%, preferably 0.1 to 2.0%, more preferably 0.1 to 1.0%, and/or Y ³⁺ : 0 to 5.0%, preferably 0.5 to 4.5%.
(10) An optical glass according to any one of (1) to (3):
^F- : 45.0-55.0%, and/or ^O2- : 45.0-55.0%.
(11) The optical glass according to (1) or (2), further comprising the following components in weight percent:
0-1% fining agent, the fining agent being one or more of Sb ³⁺ , Sn ⁴⁺ , Ce ⁴⁺ , Cl ^- , Br ^- and I ^- , preferably the fining agent is Sb ³⁺ and/or Cl ^- , the content of the fining agent is preferably 0-0.5%.
(12) An optical glass according to any one of (1) to (3):
The optical glass has a refractive index of 1.50 to 1.58, preferably 1.53 to 1.57, and an Abbe number of 70 to 80, preferably 72 to 78.
(13) An optical glass according to any one of (1) to (3):
The optical glass has a refractive index temperature coefficient dn/dt of 5.0×10 ^-6 /°C or less, preferably -5.5×10 ^-6 /°C or less, and/or a weather resistance CR of Class 2 or higher, preferably Class 1, and/or an abrasion degree of 450 or less, preferably 410 or less, and/or a Knoop hardness _HK of 300×10 ⁷ Pa or more, preferably 320×10 ⁷ Pa or more, more preferably 350×10 ⁷ Pa or more, and/or a porosity degree of Class B or higher, preferably Class A or higher, more preferably Class _A0 or higher.
(14) A glass preform produced from the optical glass according to any one of (1) to (13).
(15) An optical element produced from the optical glass according to any one of (1) to (13) or the glass preform according to (14).
(16) An optical instrument manufactured using the optical glass according to any one of (1) to (13) or the optical element according to (15).

The beneficial effects of the present invention are as follows: Through rational component design, the refractive index temperature coefficient (60-80°C) of the fluorophosphate optical glass of the present invention is less than -5.0 x ^10-6 /°C, has excellent weather resistance stability, and meets the latest application needs in the photoelectric field.

Below, we will explain in detail the embodiments of the fluorophosphate optical glass according to the present invention, but the present invention is not limited to the embodiments described below, and can be practiced with appropriate modifications within the scope of the object of the present invention. Furthermore, although some parts are omitted, the gist of the present invention is not limited by repeating the description, and hereinafter, the fluorophosphate optical glass of the present invention may be referred to simply as optical glass or glass.

[Optical glass]
The scope of each component of the fluorophosphate optical glass of the present invention will be explained below.
In this specification, each component is expressed in ionic form, and the content thereof is expressed as the weight percentage (wt%) of the cation composition relative to the total weight of all cationic compositions, and the content of the anion composition is expressed as the weight percentage (wt%) of the anion relative to the total weight of all anionic compositions, unless otherwise specified.
Specifically, the numerical ranges described herein include upper and lower limits, and the terms "greater than or equal to" and "less than or equal to" include the endpoints, and all integers and fractions subsumed within the range, but are not limited to the specific values set forth when the range is limited. As used herein, "and/or" is inclusive, e.g., "A and/or B" means A only, B only, or both A and B.
The ionic valence of each component described below is a representative value used for convenience, and is the same as other ionic valences. The ionic valence of each component of optical glass may be other than the representative value. For example, P usually exists in glass with an ionic valence of +5. Therefore, in the present invention, "P ⁵⁺ " is used as the representative value, but it may exist in other ionic valence states, which are also within the scope of protection of the present invention.

<Required and optional ingredients>
P5 ⁺ is the main component of the optical glass of the present invention, and plays the role of suppressing devitrification of the glass, increasing the viscosity of the glass, suppressing the decrease in Abbe number, and improving the weather resistance stability of the glass. If the content is less than 5.0%, the stability of the glass decreases and the devitrification resistance decreases. On the other hand, if the content exceeds 20.0%, the thermal expansion performance of the glass deteriorates and the refractive index decreases, making it impossible to meet the optical design requirements of the present invention. Therefore, the P5 ⁺ content in the present invention is 5.0-20.0%, preferably 8.0-20.0%, and more preferably 8.0-18.0%.

Al ³⁺ can be used in the structure of the glass network, improve the thermal stability and moisture resistance of the glass, and can prevent phase separation of the glass by adding it appropriately. If the content is less than 7.0%, a stable glass skeleton cannot be formed, and the above effects cannot be obtained. If the content is more than 18.0%, it becomes difficult to melt the glass, the surface tension of the glass increases, the viscosity increases, and the bubbles are difficult to eliminate. Therefore, in the present invention, the content of Al ³⁺ is 7.0-18.0%, preferably 8.5-16.0%, more preferably 9-16.0%, and the bubble degree of the glass is _A0 grade or higher.

Ba2 ⁺ can increase the refractive index and devitrification resistance of glass and adjust the thermal expansion coefficient of glass. In particular, in the present invention, by adding 56.0% or more of Ba2 ⁺ , the refractive index of glass can be significantly improved and the refractive index of glass can be prevented from being affected by temperature changes during use. Therefore, the lower limit of the Ba2 ⁺ content is 56.0%, preferably 58.0%, and more preferably 59.6%. When the ^Ba2+ content is 73.0% or more, the chemical stability and thermal stability of glass are obviously reduced and the specific gravity of glass increases. Therefore, the upper limit of the Ba2 ⁺ content is 73.0%, preferably 72.0%, and more preferably 71.0%.

Adding an appropriate amount of Sr2 ⁺ can assist in adjusting the optical constants of the glass, increase the crystallization resistance of the glass, and reduce material loss during glass processing, but if the content exceeds 12.0%, the devitrification resistance of the glass decreases and the thermal expansion properties become poor. Therefore, in the present invention, the Sr2 ⁺ content is 0.5 to 12.0%, preferably 1.0 to 12.0%, and more preferably 2.0 to 11.0%.

Adding an appropriate amount of Ca2 ⁺ can improve the thermal stability of glass, increase the mechanical strength of glass, and improve the workability of glass, but when the ^Ca2+ content is more than 5.0%, the high-temperature viscosity of glass increases obviously and the tendency to crystallize is significant. Therefore, in the present invention, the ^Ca2+ content is 0-5.0%, preferably 0-3.0%.

Adding Mg ²⁺ is advantageous for decreasing the density of the glass and improving the devitrification resistance, but is disadvantageous for obtaining a high refractive index glass. Therefore, in the present invention, the Mg ²⁺ content is added at not more than 3.0%, and by controlling the Mg ²⁺ content to 3.0% or less, the glass structure can be more stabilized and mechanical stress is less likely to occur during use of the glass. Therefore, in the present invention, the Mg ²⁺ content is 0-3.0%, preferably the Mg ²⁺ content is 0-2.0%, and more preferably the Mg ²⁺ content is 0-1.2%.

In some embodiments of the present invention, the (Ca ²⁺ +Ba ²⁺ )/(Sr ²⁺ +Mg ²⁺ ) range is controlled to be 4.5-20.0, which can make the optical glass network more stable, improve the chemical stability and thermal stability, and obtain an ideal refractive index temperature coefficient, and the refractive index temperature coefficient at 60-80°C can reach -5.0×10 ^-6 /°C or less. It is more preferable that the (Ca ²⁺ +Ba ²⁺ )/(Sr ²⁺ +Mg ²⁺ ) range is 5.0-15.0, more preferably 6.0-12.0, which can further ensure that the refractive index is increased and the imaging field is widened while obtaining a more negative refractive index temperature coefficient.

In some embodiments of the present invention, by controlling Al ³⁺ /Sr ²⁺ to 1.0-5.0, it is possible to reduce the corrosion of the molten glass liquid to the crucible, inhibit the volatilization of F to a certain extent, and improve the stripes of the glass, but if Al ³⁺ /Sr ²⁺ is less than 5.0, the thermal expansion coefficient of the glass increases and the stability of the glass decreases. The preferred range of Al ³⁺ /Sr ²⁺ is 1.1-4.0, more preferably 1.1-2.5, and even more preferably 1.1-2.0, which provides better glass stability and more ideal wear resistance.

In some embodiments, the total content of Ca2 ⁺ , ^Ba2+ , and Al3 ⁺ (Ca2 ⁺ + ^Ba2 + +Al3 ⁺ ) is controlled to 69.0-85.0%, which optimizes the synergistic effect and significantly improves the chemical stability and weather resistance of the glass, but if it exceeds 85.0%, it becomes obviously difficult to melt the glass, the weather resistance is reduced, the specific gravity of the glass increases, and the processability is poor. Therefore, the total content of ^Ca2 + + ^Ba2+ +Al3 ⁺ is preferably 70.0-81.0%, more preferably 70.0-80.0%.

In some embodiments, the devitrification resistance of the glass can be increased by controlling ( ^Ca2+ + ^Ba2 + +Al3 ⁺ )/Sr2 ⁺ within the range of 5.6 to 20.0, and more preferably ( ^Ca2 + + ^Ba2 + + ^Al3+ )/Sr2 ⁺ within the range of 7.0 to 18.0, and even more preferably within the range of 9.0 to 15.0, which appropriately increases the hardness of the glass and improves the polishing processability of the glass, helping to improve the yield of optical glass polishing.

In the present invention, the alkali metal ion represented by Rn ⁺ is one or more selected from Li ⁺ , Na ⁺ , and K ⁺ . In the present invention, Rn ⁺ plays the role of lowering the transition temperature and adjusting the process performance, but when its content exceeds 5.0%, the thermal expansion coefficient of the glass increases obviously, the chemical stability and processability of the glass decrease, and the volatility of the glass liquid increases, which is unfavorable for removing stripes. Therefore, the content of Rn ⁺ is preferably 3.0% or less, more preferably 1.0% or less. In some embodiments, even if a small amount of Rn ⁺ is contained, the chemical stability of the glass decreases sharply and the thermal expansion is significantly worse. Therefore, it is preferable that Rn ⁺ is not contained, because even if the glass of the present invention does not contain Li ⁺ , it can guarantee a good softening temperature and reduce the cost of glass raw materials.

Ln ³⁺ is a component that increases the refractive index of glass and improves the chemical stability of glass, and Ln ³⁺ is one or more selected from La ³⁺ , Gd ³⁺ , Y ³⁺ and Yb ^{3+ .} The inclusion of a small amount of Ln ³⁺ is advantageous in achieving the ideal inventive effect of the present invention in synergy with the control of (Ca ²⁺ +Ba ²⁺ )/(Sr ²⁺ +Mg ²⁺ ). Therefore, the lower limit of Ln ³⁺ is designed to be 0.1%. On the other hand, by controlling the content of Ln ³⁺ to 8.0% or less, the devitrification resistance of glass can be improved, the optical performance can be prevented from not reaching the design requirements, and the density of glass can be reduced. Therefore, in the optical glass of the present invention, the upper limit of the Ln ³⁺ content range is 8.0%, preferably 5.0%, and more preferably 3.0%. Gd ³⁺ and/or Y ³⁺ show excellent synergistic effects in some embodiments, and adding an appropriate amount is advantageous in increasing the refractive index and improving the chemical stability of glass. Therefore, Ln ³⁺ is preferably Gd ³⁺ and/or Y ³⁺ , and the content is controlled to 0.1-5.0%, preferably 0.1-4.5%, more preferably 0.5-4.0%.

Although Si ⁴⁺ can improve the stability of the glass and enhance the processability of the glass, if its content exceeds 3%, the melting performance of the glass decreases. Therefore, in the optical glass of the present invention, the Si ⁴⁺ content is 0-3.0%, preferably 0-1.0%, and more preferably no Si ⁴⁺ is contained.

Although B3 ⁺ can improve the optical constants of glass, if its content exceeds 3%, the stability of the glass deteriorates. Therefore, the B3 ⁺ content is limited to 3.0% or less, preferably 1.0% or less, and more preferably, no B3 ⁺ is contained.

Although the refractive index of glass can be increased by adding an appropriate amount of W6 ⁺ , if the content is too high, the light transmittance of the glass decreases. Therefore, in the present invention, the upper limit of the W6 ⁺ content is 3.0%, preferably 1.0% or less, and more preferably no W6 ⁺ is contained.

By adding an appropriate amount of Zr4 ⁺ , it is possible to suppress the formation of stripes in the glass due to volatilization, but if the content exceeds 3.0%, the optical glass becomes difficult to melt and it becomes difficult to control the optical constants. Therefore, the content should be 3.0% or less, preferably 1.0% or less, and more preferably no Zr4 ⁺ is contained.

In the present invention, Zn ²⁺ can lower the glass transition temperature and improve the press workability of the glass, but if the Zn ²⁺ content exceeds 3.0%, the anomalous dispersion performance of the glass deteriorates and the viscosity is too low, making the glass prone to devitrification. Therefore, in the optical glass of the present invention, the Zn ²⁺ content is 0-3.0%, preferably 0-1.0%. In addition, Zn ²⁺ makes the glass smaller and increases the degree of wear, and even if the ratio of Al ³⁺ /Sr ²⁺ is adjusted to a preferred range, Zn ²⁺ has a negative effect on wear resistance, so it is more preferable that the glass does not contain Zn ²⁺ .

Although Ti4 ⁺ can increase the refractive index of glass, it has a negative effect on the low dispersion and transmittance of glass, so the Ti4 ⁺ content is limited to 0-3.0%, more preferably 0-1.0%, and even more preferably no Ti4 ⁺ .

Although the addition of Nb5 ⁺ to glass can adjust the optical constants of the glass and increase the stability and crystallization resistance of the glass, if the content is too high, it becomes difficult for the optical constants of the glass to meet the design requirements, the optical transmittance of the glass decreases, and crystallization is likely to occur during secondary press processing of the glass. Therefore, in the present invention, the content of Nb5 ⁺ is 0-3.0%, preferably 0-1.0%, and more preferably does not contain Nb5 ⁺ .

^F- is a necessary component of the optical glass of the present invention, and can increase the Abbe number and devitrification resistance of the glass. Therefore, in the present invention, the lower limit of ^F- is 40.0%, preferably 45.0%. If the content of ^F- exceeds 60.0%, the refractive index of the glass decreases, high-temperature volatilization increases, quality stability decreases, and abrasion degree decreases. Therefore, in the present invention, the upper limit of its content is 60.0%, preferably 55.0%.

^O2- can significantly improve the glass forming stability and devitrification resistance, and the lower limit of the ^O2- content is preferably 40.0%, more preferably 45.0%. However, if the ^O2- content exceeds 60.0%, the refractive index temperature coefficient of the glass increases, and the chemical stability and crystallinity resistance tend to decrease. Therefore, the upper limit of the ^O2- content is 60.0%, preferably 55.0%.

In the present invention, 0-1% of a fining agent may be added to promote the expulsion of bubbles in the glass. The fining agent is one or more of Sb ³⁺ , Sn ⁴⁺ , Ce ⁴⁺ , Cl ^- , Br ^- and I ^- , and the content of the fining agent is 0-1.0%, preferably 0-0.5%. The fining agent is preferably Sb ³⁺ and/or Cl ^- , the content of Sb ³⁺ is 0-0.5%, preferably 0-0.1%, and the content of Cl ^- is 0-1.0%, preferably 0-0.5%.

As long as the glass properties of the present invention are not impaired, small amounts of other components not described above, such as Ge ⁴⁺ , Te ⁴⁺ , Lu ³⁺ , Bi ³⁺ , Ta ⁵⁺ and Ga ³⁺ , may be added as necessary.

<Ingredients that should not be included>
In the glass of the present invention, even when small amounts of transition metal ions such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo are contained alone or in combination, the glass is colored and specific wavelengths in the visible light region are absorbed, weakening the visible light transmission effect of the present invention. Therefore, it is preferable that optical glasses which require wavelength transmittance in the visible light region in particular not actually contain these ions.

In recent years, there has been a trend to restrict the use of Th, Cd, Tl, Os, Be, and Se cations as harmful chemicals, and environmental protection efforts are required not only in the glass manufacturing process, but also in the processing process and disposal of the finished product. Therefore, when environmental impact is a major concern, it is preferable not to contain them except in unavoidable cases. This means that the optical glass does not actually contain substances that pollute the environment. Therefore, the optical glass of the present invention can be manufactured, processed, and disposed of without the need for special environmental measures.

In consideration of the environment, it is preferable that the optical glass of the present invention does not contain As ³⁺ and Pb ²⁺ . Although As ³⁺ has the effect of removing air bubbles and preventing coloring of the glass,

The terms "not added," "not included," and "0%" used in this specification mean that the component was not intentionally added as a raw material for the glass of the present invention. However, impurities or components that were not intentionally added as raw materials and/or equipment for manufacturing the glass may be present in small or trace amounts in the final glass, and these are also covered by the patent of this invention.

The characteristics of the optical glass of the present invention will be described below.
<Refractive index and Abbe number>
The refractive index (nd) and Abbe number ( _vd ) of the glass materials are tested according to the method specified in GB/T 7962.1-2010.
The refractive index (nd) of the glass material of the present invention is 1.50-1.58, preferably 1.53-1.57, and the Abbe number (vd) is 70-80, preferably 72-78.

<Bubble level>
The bubble content of optical glass is tested according to the method specified in GB/T7962.8-2010.
The bubble content of the optical glass of the present invention is class B or higher, preferably class A or higher, and more preferably class _A0 or higher.

<Weather stability (weather resistance) CR>
The sample is placed in a test box with a saturated water vapor environment of 90% relative humidity, and the temperature is alternately circulated between 40℃ and 50℃ every hour for 15 cycles. The weather resistance classification is based on the amount of change in turbidity before and after leaving the sample. Turbidity refers to the altered layer such as "white spots" or "cloudiness" that appears on the surface of colorless optical glass after it is eroded by the atmosphere. The degree of erosion of the glass surface is measured before and after the sample erosion. The turbidity is determined by measuring the difference in turbidity between the water and the water surface. An integrating sphere turbidimeter with a relative error of the turbidity reading within ±5% is used for the turbidity measurement. The weather resistance classification is shown in Table 1.

本発明の光学ガラスの耐候性(CR)は2類以上、好ましくは1類である。

The weather resistance (CR) of the optical glass of the present invention is Class 2 or higher, and preferably Class 1.

<Refractive index temperature coefficient>
The refractive index temperature coefficient (dn/dt) is tested according to the method specified in GB/T 7962.4-2010 to measure the relative refractive index temperature coefficient at 60 to 80 °C d line.
The refractive index temperature coefficient (dn/dt) of the present invention is -5.0×10 ^-6 /°C or less, preferably -5.5×10 ^-6 /°C or less.

<Wear Degree ( _FA )>
The degree of wear is calculated by multiplying the ratio of the wear volume of the sample to the wear volume (volume) of a standard sample (K9 optical glass) under the exact same conditions, and expressing it as the formula:
F _A =V/V ₀ × 100=(W/ρ)÷(W ₀ /ρ ₀ ) × 100, where V and V ₀ are the volumetric wear amounts of the specimen and standard sample, W and W ₀ are the mass wear amounts of the specimen and standard sample, and ρ and ρ ₀ are the densities of the specimen and standard sample, respectively.
The abrasion degree of the glass of the present invention is 450 or less, and preferably 410 or less.

<Knoop hardness Hk>
Knoop hardness is measured according to the method specified in GB/T 7962.18-2010.
The Knoop hardness Hk of the present invention is 300×10 ⁷ Pa or more, preferably 320×10 ⁷ Pa or more, and more preferably 350×10 ^{7 Pa} or more.

[Production method]
The method for producing the optical glass of the present invention is as follows: the glass of the present invention is produced by using conventional raw materials and conventional processes, using dry raw materials such as phosphate, metaphosphate, oxide, fluoride, carbonate, nitrate, etc., and blending them according to the usual method, and then the prepared furnace material is put into a melting furnace at 850-1100 ° C to melt. Then, it is clarified, sufficiently homogenized, and poured or droplet-molded at a temperature below 1000 ° C (preferably molded under _N2 protective atmosphere) to obtain the optical glass of the present invention. Those skilled in the art can appropriately select the raw materials, manufacturing methods and process parameters according to the actual needs.

[Optical preforms and optical elements]
An optical preform can be manufactured from the manufactured optical glass by using press molding means such as polishing, hot press molding, precision press molding, etc. That is, an optical preform can be manufactured from the optical glass by mechanical processing such as grinding and polishing, or a blank for press molding is manufactured from the optical glass, and this blank is hot press molded and then polished to manufacture an optical preform, or the blank manufactured by polishing is precision press molded to manufacture an optical preform.

The means for manufacturing the optical preform is not limited to the above means. As described above, the optical glass of the present invention is useful for various optical elements and optical designs, and it is particularly preferable to form a blank from the optical glass of the present invention and use this blank to carry out hot press molding, precision press molding, etc. to produce optical elements such as lenses and prisms.

The optical preform and optical element of the present invention are both formed from the optical glass of the present invention. The optical preform of the present invention has the excellent properties of optical glass, and the optical element of the present invention has the excellent properties of optical glass, making it possible to provide optical elements such as various lenses and prisms with high optical value.

Examples of lenses include various lenses with spherical or aspherical lens surfaces, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses.

[Optical equipment]
Optical elements formed from the optical glass of the present invention can be used to fabricate optical instruments such as photographic devices, imaging devices, display devices, and monitoring devices.

<Optical Glass Examples>
In order to further clearly illustrate the technical solutions of the present invention, the following non-limiting examples are provided.
In the present examples, the optical glass manufacturing method described above was used to obtain optical glasses having the compositions shown in Tables 2 to 4. The properties of each glass were measured by the test methods described in the present invention, and the results are shown in Tables 2 to 4.

Optical Preform Examples
The glasses obtained in Examples 1 to 27 of the optical glass are subjected to polishing, hot press molding, precision press molding, or other press molding means to produce glass preforms such as various lenses, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses, as well as prisms.

Optical Element Examples
The preform obtained in the above optical preform example is tempered to fine-tune the refractive index while reducing stresses within the glass so that the optical properties, such as the refractive index, reach the desired values.
Each preform is then ground and polished to produce various lenses and prisms, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses. An anti-reflective coating can also be applied to the surfaces of the obtained optical elements.

Optical Instrument Examples
The optical elements manufactured according to the above optical element embodiments can be used in imaging devices, sensors, microscopes, medical technology, digital projection, communications, optical communication technology/information transmission, optics/illumination in automotive fields, photolithography technology, excimer lasers, wafers, computer chips and integrated circuits and electronic devices containing such circuits and chips by using one or more optical elements to form optical parts or components according to optical design.

Claims (17)

The cationic components are in the following weight percents:
P5 ⁺ : 5.0-20.0%, ^Ba2+ : 56.0-73.0%, Al3 ⁺ : 7.0-18.0%, Sr2 ⁺ : 0.5-12.0%, Ca2 ⁺ : 0-5.0%, Gd3 +: 0.1-5.0%, Y3 ^{+ :} 0.1-5.0%, the total content of ^Ca2 + + ^Ba2 + +Al3 ⁺ is 69.0-85.0% , (Ca2 ⁺ +Ba2 ⁺ )/(Sr2 ⁺ +Mg2 ⁺ ) is 4.5-20.0 ,
The anionic components include the following weight percents:
An optical glass having ^F- : 35.0 to 60.0%, ^O2- : 40.0 to 65.0%. 10. The optical glass of claim 1, wherein the cationic component further comprises, in weight percent:
Mg2 ⁺ : 0-3.0%, and/or Zn2 ⁺ : 0-3.0%, and/or Ln3 ⁺ : 0.2-8.0 %, and/or Rn ⁺ : 0-5.0%, and/or Nb5 ⁺ : 0-3.0%, and/or ^W6+ : 0-3.0%, and/or Ti4 ⁺ : 0-3.0%, and/or Zr4 ⁺ : 0-3.0%, and/or Si4 ⁺ : 0-3.0%, and/or B3 ⁺ : 0-3.0%,
Rn ⁺ is one or more selected from Li ⁺ , Na ⁺ , and K ⁺ , and Ln3+ is two or more types, essential for Ln3+ are Gd3+ and Y3+, ^{and may} include ^Ln2 + and ^Yb3 + ^. The cationic component comprises the following weight percentages:
P ⁵⁺ : 5.0-20.0%, Ba ²⁺ : 56.0-73.0%, Al ³⁺ : 7.0-18.0%, Sr ²⁺ : 0.5-12.0%, Mg ²⁺ : 0-3.0%, Ca 2+ : 0-5.0%, Zn ²⁺ : 0-3.0%, Si ⁴⁺ : 0-3.0%, B ^{3 +} : 0 to 3.0%, W ⁶⁺ : 0 to 3.0%, Zr ⁴⁺ : 0 to 3.0%, Ti ⁴⁺ : 0 to 3.0%, Gd ³⁺ : 0.1 to 5.0%, Y ³⁺ : 0.1 to 5.0%, Ln ³⁺ : 0. 2 to 8.0%, Rn ⁺ : 0 to 5.0%, Nb ⁵⁺ : 0 to 3.0%,
the total content of ^Ca2 + + ^Ba2 + +Al3 ⁺ is 69.0-85.0% , (Ca2 ⁺ +Ba2 ⁺ )/(Sr2 ⁺ +Mg2 ⁺ ) is 4.5-20.0 , Rn ⁺ is one or more selected from Li ⁺ , Na ⁺ and K ⁺ , ^Ln3+ is two or more essential elements including Gd3 ⁺ and Y3 ⁺ and may include La2 ⁺ and Yb3 ⁺ ,
The anionic component comprises the following weight percentages:
^F- : 35.0-60.0%, ^O2- : 40.0-65.0%,
Optical glass. The optical glass according to any one of claims 1 to 3:
P5 ⁺ : 8.0-20.0%, and/or Ba2 ⁺ : 58.0-72.0%, and/or Al3 ⁺ : 8.5-16.0%, and/or Sr2 ⁺ : 1.0-12.0%, and/or Mg2 ⁺ : 0-2.0%, and/or Ca2 ⁺ : 0-3.0%, and/or Zn2 ⁺ : 0-1.0%, and/or Ln3 ⁺ : 0.2-5.0 %, and/or Rn ⁺ : 0-3.0%, and/or Nb5 ⁺ : 0-1.0%, and/or Si4 ⁺ : 0-1.0%, and/or B3 ⁺ : 0-1.0%, and/or W6 ⁺ : 0-1.0%, and/or Zr4 ⁺ : 0-1.0%, and/or Ti ⁴⁺ : 0 to 1.0% , and Ln ³⁺ is two or more types , essential for Ln 3+ are Gd ³⁺ and Y ³⁺ , and may contain La ²⁺ and Yb ³⁺ . The optical glass according to any one of claims 1 to 3:
P5 ⁺ : 8.0-18.0%, and/or Ba2 ⁺ : 59.6-71.0%, and/or Al3 ⁺ : 9-16.0%, and/or Sr2 ⁺ : 2.0-11.0%, and/or Mg2 ⁺ : 0-1.2%, and/or no ^Zn2+ , and/or Ln3 ⁺ : 0.2-3.0 %, and/or no Rn ⁺ , and/or no ^Nb5+ , and/or no ^Si4+ , and/or no ^B3+ , and/or no ^W6+ , and/or no ^Zr4+ , and/or no ^Ti4+ , and Ln3 ⁺ essentially contains Gd3 ⁺ and Y3 ⁺ and may contain La2+ and Yb3+, or may contain two or ^more types ^. The optical glass according to any one of claims 1 to 3 :
Al ³⁺ /Sr ²⁺ is 1.0-5.0, and/or (Ca ²⁺ +Ba ²⁺ +Al ³⁺ )/Sr ²⁺ is 5.6-20.0, and/or the total content of Ca ²⁺ +Ba ²⁺ +Al ³⁺ is 70.0-81.0%. The optical glass according to any one of claims 1 to 3:
( ^Ca2 + +Ba2 ⁺ )/( ^Sr2 + +Mg2 ⁺ ) is 5.0-15.0, and/or ^Al3+ /Sr2 ⁺ is 1.1-4.0, and/or ( ^Ca2 + + ^Ba2 + +Al3 ⁺ )/Sr2 ⁺ is 7.0-18.0, and/or the total content of ^Ca2 + + ^Ba2 + +Al3 ⁺ is 70.0-80.0%. The optical glass according to any one of claims 1 to 3:
( ^Ca2 + +Ba2 ⁺ )/( ^Sr2 + +Mg2 ⁺ ) is 6.0-12.0, and/or ^Al3+ /Sr2 ⁺ is 1.1-2.0, and/or ( ^Ca2 + + ^Ba2 + +Al3 ⁺ )/Sr2 ⁺ is 9.0-15.0. The optical glass according to any one of claims 1 to 3 :
Gd3 ⁺ : 0.1 to 4.5 %, and/or Y3 ⁺ : 0.1 to 4.5 %. The optical glass according to any one of claims 1 to 3 :
Gd3 ⁺ : 0.1-2.0%, and/or Y3 ⁺ : 0.5-4.5%. The optical glass according to any one of claims 1 to 3:
^F- : 45.0-55.0%, and/or ^O2- : 45.0-55.0%. The optical glass according to claim 1 or 2:
It further comprises 0-1% by weight of a fining agent, said fining agent being one or more selected from Sb ³⁺ , Sn ⁴⁺ , Ce ⁴⁺ , Cl ⁻ , Br ⁻ and I ⁻ . The optical glass according to any one of claims 1 to 3:
The optical glass has a refractive index of 1.50 to 1.58, and/or an Abbe number of 70 to 80, and/or a refractive index temperature coefficient dn/dt of 5.0×10 ^-6 /℃ or less, and/or a weather resistance CR of Class 2 or higher, and/or an abrasion degree of 450 or less, and/or a Knoop hardness H _K of 300×10 ⁷ Pa or more, and/or a bubble degree of Class B or higher. The optical glass according to any one of claims 1 to 3:
The optical glass has a refractive index of 1.53 to 1.57, and/or an Abbe number of 72 to 78, and/or a refractive index temperature coefficient dn/dt of -5.5×10 ^-6 /℃ or less, and/or a weather resistance CR of Class 1, and/or an abrasion degree of 410 or less, and/or a Knoop hardness H _K of 350×10 ⁷ Pa or more, and/or a bubble degree of A ₀ class or more. A glass preform manufactured from the optical glass according to any one of claims 1 to 14. An optical element manufactured from the optical glass according to any one of claims 1 to 14 or the glass preform according to claim 15. An optical device manufactured using the optical glass according to any one of claims 1 to 14 or the optical element according to claim 16.