JP4428951B2 - Optical glass - Google Patents

Description

【００６２】
【表２】

【００６３】
【表３】

【００６４】
【表４】

【００６５】
【表５】

【００６６】
【表６】

【００６７】
【表７】

【００６８】
【表８】

【００６９】
【表９】

【００７０】
【表１０】

【００７１】
【表１１】

【００７２】
【表１２】

【００７３】
高屈折率高分散光学ガラスは、可視光線の短波長領域に吸収をもつ成分を多く含有しており、更に、ガラスの屈折率が高くなるほど、ガラス表面における光線反射率が大きくなるため、反射損失を含む光線透過率は悪くなる傾向となる。そのため、ガラスの屈折率が高くなるほどＩＳＯ色特性指数のＧ，Ｒ値も大きくなる傾向がある。従来、製造および／または販売されていたＰｂ成分を多く含有したガラスであるＰＢＨ５３Ｗ、ＰＢＨ６Ｗについても、図１、２中に●印で示したようにｎｄが高くなるにつれて、ＩＳＯ／ＣＣＩの値が大きくなる傾向がある。
【００７４】
表１〜１２および図１、２に示すとおり、本発明にかかる実施例（Ｎｏ．１〜４８）のガラスは、いずれも、比較例（Ｎｏ．Ａ〜Ｆ）のガラスに比べ、いずれも、ＩＳＯ／ＣＣＩのＧ，Ｒ値が小さく、短波長領域で優れた透過率すなわち内部透過率を得ることができる。また、比較例（Ｇ〜Ｉ）は、ＩＳＯ／ＣＣＩのＧ，Ｒ値が低いが、光学的に不均質な部分が顕著に多いために内部品質が悪く、光学機器のレンズ等として用いることは困難である。
また、上記実施例１〜４８のガラスは、いずれも、優れた内部品質を示しており、比較例Ａ〜Ｉのガラスと比べ、優れた内部品質を有しつつ、かつ、低いＩＳＯ／ＣＣＩの値、すなわち短波長領域で優れた光線透過率を得ることができる。
【００７５】
【発明の効果】
以上述べたとおり、本発明の光学ガラスは、特定範囲のＰ₂Ｏ₅−Ｎｂ₂Ｏ₅−ＢａＯ−Ｎａ₂Ｏ系のガラスであり、所定範囲の光学恒数において、短波長領域で優れた透過率および内部透過率を示すため、ＩＳＯ／ＣＣＩの値（Ｇ，Ｒ値）が低く、環境対策にコストを有するＰｂＯおよびＡｓ₂Ｏ₃を含有せず、かつ、内部品質が優れたガラスを得ることができる。
さらに上記組成系にＧｄ₂Ｏ₃を添加することによって、さらに耐失透性が優れ、かつ、さらに優れた内部品質を持つ高屈折率高分散性の光学ガラスを得ることができる。
更に、ガラス転移点（Ｔｇ）も低下させることが可能であるため、プレス成形後の研削または研磨を必要とせずにそのままレンズ等の光学素子として用いることが可能な精密プレス用ガラス、いわゆるモールドプレス用のガラスとしても好適である。
【００７６】
【図面の簡単な説明】
【図１】ＪＯＧＩＳ０２−¹⁹⁷⁵に規定される３５０ｎｍ〜６８０ｎｍのガラスバルク材の光線透過率から算出した、ＪＩＳ７０９７（ＩＳＯ色特性指数（ＩＳＯ／ＣＣＩ）による写真撮影用の色特性の表し方）に規定されるＩＳＯ色特性指数（ＩＳＯ／ＣＣＩ）のＧ値［小数点第２位まで算出］をＸ軸、屈折率（ｎｄ）をＹ軸としてプロットしたＸ−Ｙ直行座標図。
【図２】ＪＯＧＩＳ０２−¹⁹⁷⁵に規定される３５０ｎｍ〜６８０ｎｍのガラスバルク材の光線透過率から算出した、ＪＩＳ７０９７（ＩＳＯ色特性指数（ＩＳＯ／ＣＣＩ）による写真撮影用の色特性の表し方）に規定されるＩＳＯ色特性指数（ＩＳＯ／ＣＣＩ）のＲ値［小数点第２位まで算出］をＸ軸、屈折率（ｎｄ）をＹ軸としてプロットしたＸ−Ｙ直行座標図。[0001]
BACKGROUND OF THE INVENTION
The present invention has optical constants in the range of refractive index (nd) of 1.78 to 1.90, Abbe number (νd) of 18 to 27, excellent light transmittance and resistance to devitrification, and glass. The present invention relates to an optical glass having a high refractive index and high dispersibility with excellent internal quality.
[0002]
[Prior art]
In the production of optical glass, in order to produce highly homogeneous glass with good yield, it is common to use a melting apparatus in which at least a part or all in contact with the molten glass is made of platinum or a platinum alloy material. (For example, it is possible to use a crucible, tank, stirring blade or shaft made of platinum or platinum alloy.) However, in this case, if the melting temperature is increased or the melting time is increased, the molten glass dissolves in the molten glass. Since the platinum amount increases and the platinum ions in the melted glass absorb light, the light transmittance of the glass, particularly the light transmittance in the short wavelength region, tends to decrease.
[0003]
On the other hand, the superiority or inferiority of the internal quality of optical glass is evaluated by the degree of striae, bubbles, and foreign matters (such as microcrystals or microbubbles due to devitrification) in the glass. In the case of glass with poor defoaming and melting properties, the melting temperature is aimed at improving the internal quality of the glass by reducing striae, bubbles and foreign matters (such as microcrystals such as devitrification or microbubbles). When processing such as increasing the melting temperature, increasing the melting time, increasing the defoaming agent, etc., as described above, the amount of platinum dissolved in the glass, impurities, etc. The light transmittance of the glass decreases due to various factors.
[0004]
Lenses made of high-refractive index, high-dispersion glass are used in combination with lenses made of low-refractive index, low-dispersion optical glass for the purpose of correcting optical system chromatic aberration in optical design. Used in optical equipment. Generally, the higher the refractive index and the higher the dispersion, the more the glass needs to contain components that impart high refractive index and high dispersion properties. The light transmittance in the short wavelength region tends to deteriorate. Furthermore, the higher the refractive index of the glass, the higher the light reflectance at the glass surface. As the refractive index becomes higher, the light transmittance due to this decreases.
[0005]
As a high refractive index and high dispersion optical glass excellent in light transmittance in a short wavelength region, a lead silicate glass containing a large amount of lead has been conventionally known. For example, JP-A-57-34042 discloses SiO containing a large amount of PbO with a small amount of platinum dissolved from the platinum crucible and excellent light transmittance₂-PbO-B₂O_ThreeA high refractive index, high dispersion glass of the system is disclosed. However, such a glass containing a large amount of PbO is insufficient in chemical durability and has a large specific gravity. Therefore, when it is used as a lens, it is an obstacle to weight reduction of optical equipment that is rapidly progressing. It becomes. In recent years, there has been a movement to stop using glass containing lead, which is an environmental pollutant, and it does not contain lead and has a light transmittance in the short wavelength region.₂-PbO-B₂O_ThreeThere is a need for optical glasses having high refractive index and high dispersibility that are as excellent as the system.
[0006]
As one of the methods for evaluating the light transmittance of optical glass, JOGIS02-¹⁹⁷⁵In this method, the color balance of transmitted light, which is important in optical design, cannot be sufficiently evaluated.
As a method of expressing the color balance of transmitted light, the ISO color characteristic index (ISO / CCI (ISO / CCI) (ISO / CCI (ISO / CCI)) is calculated by a method defined in JIS B 7097 (How to express color characteristics for photography by ISO color characteristic index (ISO / CCI)). B / G / R)), JOGIS02-¹⁹⁷⁵The method of evaluating the color balance of the glass bulk material itself by calculating this from the light transmittance data of the glass of 350 nm to 680 nm measured by the above method is used.
[0007]
Generally, the ISO color characteristic index of high refractive index and high dispersion glass is JOGIS02-¹⁹⁷⁵The average transmittance of the glass of 530 nm to 680 nm measured by₂-PbO-B₂O_ThreeIn the glass bulk material that is almost equivalent to the system, and the green color sensitive layer of the average color film and the photographic response of the red sensitive layer are almost equivalent, the more excellent the light transmittance in the short wavelength region of visible light, This indicates that the G value and the R value are small when the B value of the ISO color characteristic index is 0.
For example, PbO-SiO, which is a typical high lead content glass sold in the past.₂Glass, PBH53W, PBH6W (Ohara's glass type) has good transmittance and internal transmittance in the short wavelength region, and therefore has a property that G and R values of ISO color characteristic index are small. .
[0008]
As a high-refractive index high-dispersion optical glass containing no PbO, Japanese Patent Application Laid-Open No. 54-1112915 discloses P having a very wide composition range and optical constant range.₂O_Five-R^I ₂O and / or ZnO-Nb₂O_FiveThe optical glass of the system is disclosed, but among the specifically disclosed glasses, the glass having a refractive index (nd) of 1.78 or more has insufficient devitrification resistance, and has poor meltability and is contained in the glass. As a result, foreign substances (microcrystals) are likely to be produced, and thus glass having good internal quality cannot be obtained. Therefore, if the melting temperature is increased or the melting time is increased in order to improve the internal quality, the amount of platinum penetration increases, and the G and R values of the ISO color characteristic index of the glass bulk material increase. -SiO₂There is a disadvantage that the color balance is deteriorated as compared with the glass of the system.
[0009]
Japanese Patent Application Laid-Open No. 52-133201 discloses P having a very wide composition range and optical constant range.₂O_Five-B₂O-Nb₂O_FiveAnd / or R^IIAlthough the optical glass of the system is disclosed, among the glasses disclosed specifically, the glass not containing PbO and having a refractive index (nd) of 1.78 or more has insufficient devitrification resistance, Since the meltability is poor and foreign substances (microcrystals) are likely to be generated in the glass, a glass having good internal quality cannot be obtained. And for the above reason, when trying to improve the internal quality, PbO—SiO₂There is a disadvantage that the color balance is deteriorated as compared with the glass of the system.
[0010]
JP-A-5-270853 discloses SiO having a very wide optical constant range.₂-B₂O_Three-P₂O_Five-Nb₂O_Five-Na₂O and / or K₂Although O-based optical glass is disclosed, glass having a refractive index (nd) of 1.78 or more among the specifically disclosed glasses has a low light transmittance in the short wavelength region, and thus glass bulk. G and R values of ISO color characteristic index of material are large, that is, PbO-SiO₂Compared with the glass of the glass type, the color balance is not good, and the meltability is also poor, and foreign matter and bubbles (microcrystals) are likely to occur in the glass. To do.
[0011]
Japanese Patent Laid-Open No. 9-188540 discloses P₂O_Five-Nb₂O_FiveThe optical glass of the system is disclosed, but among the glass specifically disclosed, the glass having a refractive index (nd) of 1.78 or more has G and R values of ISO color characteristic index of the glass bulk material. Since it is large and has poor meltability, foreign substances and bubbles (microcrystals) are likely to be generated in the glass. When trying to improve this, PbO-SiO₂The color balance is further deteriorated as compared with the glass of the system.
[0012]
JP-A-8-157231 discloses P.₂O_Five-B₂O_Three-Nb₂O_Five-Li₂O-Na₂O-SiO₂System and P₂O_Five-B₂O_Three-Nb₂O_Five-Li₂O-WO_ThreeAlthough the optical glass of the system is disclosed, the foaming is not good, and it is difficult to obtain a homogeneous glass, and furthermore, the absorption in the short wavelength region is large, so the G and R values of the ISO color characteristic index of the glass bulk material are It gets bigger.
[0013]
Japanese Patent Laid-Open No. 2001-58845 discloses P₂O_Five-Na₂O-Nb₂O_Five-Bi₂O_ThreeAlthough the optical glass of the system is disclosed, the glass disclosed specifically is not good in foaming, and it is difficult to obtain a homogeneous glass, and furthermore, the absorption in the short wavelength region is large, so PbO-SiO₂Compared with the glass of the system, the G and R values of the ISO color characteristic index of the glass bulk material are increased.
[0014]
Japanese Patent Laid-Open No. 2002-173336 discloses P₂O_Five-B₂O_3-R ’₂Although an O-based optical glass is disclosed, the specifically disclosed glass does not have a good bubble breakage, and it is difficult to obtain a homogeneous glass, and microcrystals are easily generated in the glass. Furthermore, since the absorption in the short wavelength region is large, PbO—SiO₂Compared with the glass of the system, the G and R values of the ISO color characteristic index of the glass bulk material are increased.
[0015]
Japanese Patent Application Laid-Open No. 2002-201041 discloses P for precision presses having high transmittance.₂O_Five-WO_ThreeAlthough optical glass of the system is disclosed, the absorption in the short wavelength region is large, and the specifically disclosed glass is not good in foaming and it is difficult to obtain a homogeneous glass, thus improving the internal quality Therefore, if the melting temperature is increased or the melting time is lengthened, the amount of platinum penetration increases, and the G and R values of the ISO color characteristic index of the obtained glass bulk material are further increased. .
[0016]
[Problems to be solved by the invention]
The object of the present invention is to comprehensively improve the various disadvantages found in the prior art, with an optical index in the range of refractive index (nd) of less than 1.78 to 1.90 and Abbe number (νd) of 18 to 27. In a high refractive index, high dispersion glass having a constant, SiO₂-Glass having excellent light transmittance in the short wavelength region while maintaining the color balance of the PbO-based optical glass, that is, the G and R values of the ISO color characteristic index are small, and the internal quality and devitrification resistance are high. An object of the present invention is to provide an optical glass having a high refractive index.
[0017]
[Means for Solving the Problems]
As a result of intensive studies to solve the problems found in the conventional glass, the present inventor has found that P that has not been known so far.₂O₅-BaO-Na₂O-Nb₂O₅A high refractive index and high dispersion optical glass with excellent light transmission including color balance, that is, low G and R values of ISO color characteristic index, and excellent internal quality. In addition, Gd₂O₃In addition, the light transmittance in the short wavelength region is further improved, the internal quality is remarkably excellent, the devitrification resistance is extremely excellent, and the high refractive index and high dispersion optical glass having a low glass transition point. It has been found that it can be easily obtained, and the present invention has been made.
That is, the invention according to claim 1 is a mass percentage,
P₂O₅ 15-35%,
Nb₂O₅ 40-60%,
Na₂O 0.5 to less than 15%,
BaO 3 to less than 25%,
TiO ₂ 0-2.6%
And in a mass percentage ratio
(BaO + Nb₂O₅) / {(TiO₂+ WO₃) × 3 + Bi₂O₃+ Nb₂O₅}> 1.0
And yetTeO ₂ and3. An optical glass comprising no lead component and no arsenic component, having a refractive index (nd) of 1.78 to 1.90 and an Abbe number (νd) of 18 to 27, and comprising: The invention is in mass percentage,
Gd₂O₃ 0-5% and / or
K₂O 0-10% and / or
Li₂O 0-10% and / or
Bi₂O₃ 0-5% and / or
MgO 0-10% and / or
CaO 0-10% and / or
SrO 0-10% and / or
ZnO 0-3% and / or
SiO₂ 0-5% and / or
B₂O₃ 0-5% and / or
Al₂O₃ 0-4% and / or
Ta₂O₅ 0-5% and / or
ZrO₂ 0-3% and /Or
WO₃ 0-8% and / or
Sb₂O₃ 0-0.02%
The optical glass according to claim 1, wherein the invention according to claim 3 is the Japan Optical Glass Industry Association Standard JOGIS02-¹⁹⁷⁵An XY orthogonal coordinate diagram with the ISO color characteristic index G value calculated by using the spectral transmittance of the glass material obtained by (Measurement method of coloring degree of optical glass) as the X axis and the refractive index (nd) as the Y axis. In the region where the ISO color characteristic index G value is smaller and the refractive index (nd) is higher than the straight line (SL3-G): Y = 0.0277X + 1.725, and JOGIS02-¹⁹⁷⁵In the XY orthogonal coordinate diagram in which the ISO color characteristic index R value calculated by using the spectral transmittance of the glass bulk obtained by the above is the X axis and the refractive index (nd) is the Y axis, a straight line (SL3-R): Y The optical glass according to claim 1 or 2, wherein the ISO color characteristic index R value is smaller and the refractive index (nd) is higher than 0.0273X + 1.7102. The invention described in Item 4 is the Japan Optical Glass Industry Standard JOGIS12-¹⁹⁹⁴The sum of the cross-sectional areas of the bubbles in the 100 ml glass shown in Table 1 of (Optical Glass Foam Measurement Method) is Class 1 to Class 4, and Japan Optical Glass Industry Association Standard JOGIS13-¹⁹⁹⁴The sum total of the cross-sectional areas of foreign matter in 100 ml of glass shown in Table 1 of "Measurement method of foreign matter in optical glass" is Class 1 to Class 4. And the invention according to claim 5 is the Japan Optical Glass Industry Association Standard JOGIS02-.¹⁹⁷⁵An XY orthogonal coordinate diagram with the ISO color characteristic index G value calculated by using the spectral transmittance of the glass material obtained by (Measurement method of coloring degree of optical glass) as the X axis and the refractive index (nd) as the Y axis. In the region where the ISO color characteristic index G value is smaller and the refractive index (nd) is higher than the straight line (SL5-G): Y = 0.0329X + 1.7174, and JOGIS02-¹⁹⁷⁵In the XY orthogonal coordinate diagram in which the ISO color characteristic index R value calculated by using the spectral transmittance of the glass bulk obtained by the above is the X axis and the refractive index (nd) is the Y axis, a straight line (SL5-R): Y The optical color according to any one of claims 1 to 4, wherein the ISO color characteristic index R value is smaller and the refractive index (nd) is higher than 0.0288X + 1.7130. The invention according to claim 6 is a percentage by mass.
P₂O₅ 15-35%,
Nb₂O₅ 40-60%,
Na₂O 0.5 to less than 15%,
BaO 3 to less than 25%,
Including
Gd₂O₃ 0-4% and / or
K₂O 0-6% and / or
Li₂O 0 to less than 6% and / or
Bi₂O₃ Less than 0-5% and / or
MgO 0 to less than 10% and / or
CaO 0 to less than 10% and / or
SrO 0 to less than 10% and / or
ZnO 0-3% and / or
SiO₂ Less than 0-5% and / or
B₂O₃ Less than 0-5% and / or
Al₂O₃ 0-4% and / or
Ta₂O₅ 0-5% and / or
ZrO₂ 0-3% and / or
Sb₂O₃ 0-0.02% and / orOr
WO₃ 0-8% and / or
Fluoride in which a part or all of the metal oxide is substituted contains 0 to 5% in total amount as F (fluorine),
And in the mass percentage ratio
(BaO + Nb₂O₅) / {(TiO₂+ WO₃) × 3 + Bi₂O₃+ Nb₂O₅}> 1.0
1 to 5 characterized in thatofThe optical glass according to any one of the above, and the invention according to claim 7 is a mass percentage.
P₂O₅ 15-35%,
Nb₂O₅ 40-60%,
Na₂O 0.5 to less than 15%,
BaO 3-25%
Including
Gd₂O₃ 0.1-4% and / or
K₂O 0-6% and / or
Li₂O 0 to less than 6% and / or
Bi₂O₃ 0 to less than 4.5% and / or
MgO 0 to less than 10% and / or
CaO 0 to less than 10% and / or
SrO 0 to less than 10% and / or
ZnO 0-3% and / or
SiO₂ Less than 0-5% and / or
B₂O₃ Less than 0-5% and / or
Al₂O₃ 0-4% and / or
Ta₂O₅ 0-5% and / or
ZrO₂ 0-3% and / or
Sb₂O₃ 0-0.01% and /Or
WO₃ 0-8% and / or
Fluoride in which a part or all of the metal oxide is substituted contains 0 to 5% in total amount as F (fluorine),
And in the mass percentage ratio
(BaO + Nb₂O₅) / {(TiO₂+ WO₃) × 3 + Bi₂O₃+ Nb₂O₅}> 1.0
1 to 6, whereinofAn optical glass according to any one of claims 1 to 8, and the invention according to claim 8 is a standard of the Japan Optical Glass Industry Association JOGIS02-.¹⁹⁷⁵An XY orthogonal coordinate diagram with the ISO color characteristic index G value calculated by using the spectral transmittance of the glass material obtained by (Measurement method of coloring degree of optical glass) as the X axis and the refractive index (nd) as the Y axis. In the region where the ISO color characteristic index G value is smaller and the refractive index (nd) is higher than the straight line (SL8-G): Y = 0.0329X + 1.7245, and JOGIS02-¹⁹⁷⁵In the XY orthogonal coordinate diagram in which the ISO color characteristic index R value calculated by using the spectral transmittance of the glass bulk obtained by the above is the X axis and the refractive index (nd) is the Y axis, a straight line (SL8-R): Y The optical characteristic according to claim 1, wherein the ISO color characteristic index G value is smaller and the refractive index (nd) is higher than 0.0288X + 1.7208. The invention according to claim 9 is a percentage by mass.
P₂O₅ 15-30%
Nb₂O₅ 42-60%,
Na₂O 0.5 to less than 10%,
BaO 5 to less than 25%,
In addition,
Gd₂O₃ 0.1-4% and / or
K₂O 0-6% and / or
Li₂O 0-2% and / or
Bi₂O₃ 0 to less than 4.5% and / or
MgO 0 to less than 10% and / or
CaO 0 to less than 10% and / or
SrO 0 to less than 10% and / or
ZnO 0-3% and / or
SiO₂ Less than 0.1-4% and / or
B₂O₃ Less than 0.2-5% and / or
Al₂O₃ 0-4% and / or
Ta₂O₅ 0-5% and / or
ZrO₂ 0-3% and / or
Sb₂O₃ 0-0.01% and /Or
WO₃ 0-5% and / or
0 to 5% of the total amount of fluoride in which a part or all of the metal oxide is substituted as F (fluorine)
And in a mass percentage ratio
(BaO + Nb₂O₅) / {(TiO₂+ WO₃) × 3 + Bi₂O₃+ Nb₂O₅}> 1.1
9. The method according to claim 1, whereinofThe optical glass according to any one of claims 1 to 10, and the invention according to claim 10 is a mass percentage.
P₂O₅ 15-35%,
Nb₂O₅ 40-60%,
Gd₂O₃ 0.1-4%,
Na₂O 0.5 to less than 10%,
K₂O 0-6%,
However, Na₂O and K₂Total amount of O less than 0.5-10%,
Bi₂O₃ 0-5%,
MgO 0 to less than 10%,
CaO 0 to less than 10%,
SrO 0 to less than 10%,
BaO 0.5 to less than 25%,
ZnO 0-3%,
SiO₂ 0-5%,
B₂O₃ 0.2 to less than 5%,
Al₂O₃ 0-3%,
Ta₂O₅ 0-5%,
ZrO₂ 0-3%,
Sb₂O₃ 0-0.03%
And a fluoride in which a part or all of the metal oxide is substituted in a total amount of F (fluorine) of 0 to 5%, lead,TeO ₂ ,WO₃And TiO₂And a refractive index (nd) in the range of 1.78 to 1.90 and an Abbe number (νd) in the range of 18 to 27.The invention described inIn mass percentage
P₂O₅ 15-30%
Nb₂O₅ 42-60%,
Gd₂O₃ 0.1-4%,
Na₂O 0.5-9.6%,
K₂O 0-6%,
However, Na₂O and K₂The total amount of O 0.5-9.6%,
Bi₂O₃ 0-4.5%,
MgO 0 to less than 10%,
CaO 0 to less than 10%,
SrO 0 to less than 10%,
BaO 0.5 to less than 25%,
ZnO 0-3%,
SiO₂ Less than 0.1-4%,
B₂O₃ 0.2 to less than 5%,
Al₂O₃ 0-3%,
Ta₂O₅ 0-5%,
ZrO₂ 0-3%,
Sb₂O₃ 0-0.03%
And 0 to 5% of the total amount of fluoride in which a part or all of the metal oxide is substituted as F (fluorine), a lead component,TeO ₂ ,WO₃Ingredients and TiO₂13. An optical glass characterized in that it contains no components, and has an optical constant of a refractive index (nd) in the range of 1.78 to 1.90 and an Abbe number (νd) in the range of 18 to 27, The invention is based on JOGIS12-¹⁹⁹⁴The total cross-sectional area of bubbles in 100 ml of glass shown in Table 1 of “Method for measuring bubbles in optical glass” is class 1 to class 3, and JOGIS13-¹⁹⁹⁴The total cross-sectional area of the foreign matter in the 100 ml glass shown in Table 1 of “Measurement method of foreign matter in optical glass” is class 1 to class 3, and JOGIS11-¹⁹⁷⁵The optical glass according to any one of claims 1 to 11, wherein the degree of striae shown in Table 2 of "Measurement method of striae of optical glass" is grades 1 to 3. Yes, the invention of claim 13 is the Japan Optical Glass Industry Association Standard JOGIS11-¹⁹⁷⁵The degree of striae shown in Table 2 of “Measurement method of striae of optical glass” is class 1 or class 2, and JOGIS12-¹⁹⁹⁴The sum of the cross-sectional areas of the bubbles in 100 ml of glass shown in Table 1 of “Method for measuring bubbles in optical glass” is class 1 or class 2, and JOGIS13-¹⁹⁹⁴13. The total sum of the cross-sectional areas of foreign matters in 100 ml of glass shown in Table 1 of “Measurement method of foreign matters in optical glass” is class 1 or class 2. The optical glass described in 1.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, the reason why the composition range of each component is limited as described above in the optical glass of the present invention will be described.
P₂O_FiveIs a component that imparts high dispersibility to the glass and imparts high transmittance. Compared to silicate glass and borate glass, it has excellent meltability and excellent devitrification during pressing. And excellent light transmittance can be obtained. Moreover, there exists an effect which improves the devitrification resistance of glass, and in order to acquire the said effect, it is preferable to make the quantity into 15% or more. On the other hand, if it exceeds 35%, it is difficult to obtain the desired high refractive index, and the devitrification resistance tends to deteriorate. In particular, in order to obtain a high refractive index and highly dispersible glass excellent in devitrification resistance, it is more preferable that the lower limit is 16% and / or the upper limit is 33%. Most preferably, the lower limit is 17% and / or the upper limit is 30%.
[0019]
Nb₂O_FiveIs a component that vitrifies in a wide range, and has the effect of increasing the refractive index and dispersion of the glass and improving the chemical durability of the glass without increasing the degree of coloration of the glass. It is a useful component. And in order to fully acquire these effects, it is preferable to set it as 40% or more. On the other hand, if it exceeds 60%, the devitrification resistance of the glass deteriorates and the light transmittance tends to decrease, so it is preferably 60% or less. More preferably, the lower limit is 41% and / or the upper limit is 58%, and most preferably the lower limit is 42% and / or the upper limit is 56.5%.
[0020]
WO_ThreeIs a component that can provide a high refractive index and a high dispersion characteristic while maintaining a low melting point characteristic, and can be optionally added, but if it exceeds 8%, the light transmittance in the short wavelength region tends to deteriorate. This tends to increase the G / R values of ISO / CCI, so 8% or less is preferable, and 5% or less is more preferable. In particular, when it is desired to obtain a product excellent in internal quality and having a very good light transmittance in the short wavelength region, it is preferably not contained.
[0021]
TiO₂Is a component that has the effect of increasing the refractive index of glass, but is also a component that tends to deteriorate the light transmittance of glass, and further tends to be devitrified easily during melting and pressing, so that it is 5% or less. Preferably, 3% or less is more preferable. In particular, when it is desired to obtain a product excellent in internal quality and having a very good light transmittance in the short wavelength region, it is preferably not contained.
[0022]
BaO has the effect of stabilizing the glass during melting, preventing devitrification and suppressing the ease of breaking the glass, and increasing the light transmittance of the glass in this composition range. However, on the other hand, if the amount is too large, it is difficult to obtain the high refractive index and high dispersibility aimed by the present invention. For this reason, preferably the lower limit is 0.5% and / or the upper limit is less than 25%, more preferably the lower limit is 3% and / or the upper limit is 24.7%, most preferably the lower limit is 5% and / or The upper limit is 24.5%.
[0023]
In order to obtain particularly good ISO / CCI G and R values, BaO, Nb₂O_Five, TiO₂, WO_Three, Bi₂O_ThreeCalculated by the value of weight percent of each component
(BaO + Nb₂O_Five) / {(TiO₂+ WO_Three) × 3 + Bi₂O_Three+ Nb₂O_Five} Is preferably larger than 1.0.
In order to obtain a high refractive index and high dispersion glass without using PbO, Nb₂O_FiveTiO₂, WO_Three, Bi₂O_ThreeIt is preferable to introduce a component imparting high refractive index and high dispersion characteristics such as But Nb₂O_FiveTiO in comparison with₂, WO_Three, Bi₂O_ThreeHas a larger absorption in the short wavelength region, especially increases ISO / CCI (G, R value), and also tends to cause phase separation and bubbles during melting of the glass, so that the internal quality is good. In order to make it difficult to obtain glass, TiO is adjusted so that the ratio value specified above is 1.0 or less.₂, WO_Three, Bi₂O_ThreeIt is not preferable to relatively increase the content of. And Nb to increase the refractive index and dispersion of the glass₂O_FiveCoexisting with BaO is to stabilize the glass at the time of melting as described above while keeping the glass at a high refractive index and high dispersion, and to prevent devitrification in the glass and light in the short wavelength region. There is an effect of improving the transmittance, and adjusting the content of these components so as to have the ratio specified above is a very important point in order to easily obtain the objective glass.
Preferably the value of this formula is greater than 1.1, and most preferably the value of this formula is greater than 1.15.
[0024]
Gd₂O_ThreeThe P of the present invention₂O_Five-Nb₂O_Five-BaO-R₂In the O-based glass, while maintaining the glass at a high refractive index, the effect of improving the light transmittance of the glass, the effect of stabilizing and improving the devitrification resistance of the glass during melting, and the homogeneity of the glass It is a useful component that has the effect of making it possible to easily obtain a glass with excellent internal quality, because it has the effect of improving the properties and the property of hardly causing phase separation. Although it is a component that can be added, if the amount exceeds 5%, the devitrification is worsened. Preferably, the lower limit is 0.1% and / or the upper limit is 4.8%, more preferably the lower limit is 0.3% and / or the upper limit is 4.5%, most preferably the lower limit is 0.5% and / Or the upper limit is 4%.
[0025]
Na₂O is a very effective component for lowering the melting temperature and preventing the coloring of the glass, and can lower the glass transition temperature and the yield point temperature. It is preferable to contain 0.5% or more. However, when the amount is 15% or more, it is difficult to obtain a glass having a high refractive index as intended by the present invention. In order to obtain a glass having a particularly high refractive index and excellent weather resistance, the upper limit is more preferably less than 10%. Furthermore, when it is desired to obtain a glass having a small average linear expansion coefficient, the content is most preferably 9.6% or less. The lower limit is more preferably 1% or more, most preferably 3% or more.
[0026]
K₂O is a component that can lower the glass transition temperature and the yield point temperature, and can be added arbitrarily. However, if it exceeds 10%, it tends to devitrify when the glass melts, resulting in an internal quality. It tends to get worse. In addition, the workability tends to be deteriorated and the glass tends to break, so the preferable upper limit is 6% or less. In the case where the glass transition temperature and yield point temperature can be lowered to desired values using other components, it is most preferable not to contain them.
[0027]
If you want to obtain a material with very good weather resistance or a material with a small average linear expansion coefficient,₂O and K₂The total amount of O is preferably less than 10%. The total amount of these two components is more preferably 9.8% or less, and most preferably 9.6% or less.
[0028]
Li₂O has the effect of lowering the glass transition temperature and the yield point temperature, and is an optional component, but if it exceeds 10%, the chemical durability tends to deteriorate, and the processability is also low. Tends to get worse. More preferably, it is less than 6%. Further, in order to obtain a glass having a small chemical durability and an average coefficient of linear expansion and good workability, it is most preferably 2% or less.
[0029]
SiO₂Has an effect of improving the chemical durability of the glass and can be optionally added. However, if it exceeds 5%, the meltability of the glass tends to deteriorate. In particular, the upper limit should be 5% or less in order to obtain glass with good meltability. In particular, when it is desired to obtain a glass having excellent chemical durability, the lower limit is 0.1% and / or the upper limit is less than 5%, and the more preferable range is 0.2% and / or the upper limit. Is less than 4%, and the most preferable range is that the lower limit is 0.3% and / or the upper limit is 2% or less.
[0030]
B₂O_ThreeIs an optional component that has the effect of improving devitrification resistance. In particular, P₂O_Five-Nb₂O_FiveSiO2 in glass₂Ingredients tend to remain undissolved, but B₂O_ThreeBy coexisting, it is possible to easily obtain a glass having improved melting properties and excellent chemical durability. However, if it exceeds 5%, it is difficult to obtain the high refractive index and high dispersibility aimed by the present invention. In order to sufficiently obtain the above-described good effects without revealing such defects, the lower limit is preferably 0.2% and / or the upper limit is less than 5%, and most preferably the lower limit is 0.00. 3% and / or the upper limit is 3%.
[0031]
Each component of MgO, CaO, and SrO is a component that can be optionally added and has an effect of stabilizing glass during melting and preventing devitrification. If the amount of each of these components exceeds 10%, homogeneous glass tends to be difficult to obtain. More preferably, each is less than 10%, most preferably the upper limit of CaO is 3% and / or MgO free and / or SrO free.
[0032]
Bi₂O_ThreeIs a component that can be optionally added and has the effect of lowering the melting point of the glass and making the glass have a high refractive index and high dispersion. However, if it exceeds 5%, the transmittance in the short wavelength region tends to deteriorate, and as a result, ISO / CCI (G, R value) tends to increase and the color balance tends to deteriorate. Furthermore, since the tendency to devitrification is likely to increase when the glass is melted, the amount should be 5% or less. It is preferably less than 5%, more preferably 4.5% or less, and most preferably less than 4.5%.
[0033]
Al₂O_ThreeIs an optionally added component that improves the chemical durability of the glass and increases the light transmittance, but if it exceeds 4%, the tendency to devitrify the glass tends to increase. A more preferred upper limit is 3%, and a most preferred upper limit is 2%.
[0034]
ZnO and ZrO₂Both are effective components for adjusting the optical constant of the glass and can be optionally added. However, if the amount of each component exceeds 3%, the devitrification resistance of the glass deteriorates. easy. More preferably, the upper limit of ZnO is less than 3% and / or ZrO₂The upper limit of 2.5%, most preferably the upper limit of ZnO is 2.9% and / or ZrO₂Is 2%.
[0035]
Ta₂O_FiveIs an optionally added component that has the effect of increasing the refractive index of the glass. However, when the amount exceeds 5%, striae easily occurs, and as a result, it is difficult to obtain a homogeneous glass. Ta₂O_FiveIs a component that is very expensive in terms of raw material unit price, so that it is preferable to add it only when necessary in order to obtain desired characteristics, and the preferable upper limit is 3%, and it is most preferable not to contain it.
[0036]
Sb₂O_ThreeIs a component that can be optionally added when it contains a small amount, and has the effect of improving foaming (defoaming) when the glass is melted. However, if the amount increases as much as possible, the light transmittance in the short wavelength region tends to deteriorate, and as a result, ISO / CCI (G, R value) is large and the color balance is likely to deteriorate. Therefore, it should be up to 0.03%. A preferable upper limit is 0.02%, a more preferable upper limit is 0.01%, and a most preferable upper limit is 0.001% or less.
[0037]
Further, the optical glass of the present invention may contain a fluoride in which a part or all of the above metal oxide is substituted in a total amount of 5% as F (fluorine). F (fluorine) has an effect of improving bubble transmission (defoaming property) and improving light transmittance on the short wavelength side of visible light. However, if the amount of F (fluorine) exceeds 5%, striae tend to occur. A more preferable upper limit is 3%, and a most preferable upper limit is 1%.
[0038]
Since Pt has a function of reducing the transmittance in the short wavelength region, the Pt content in the glass should be suppressed as much as possible. The content is preferably 1.5 ppm or less, more preferably 1 ppm or less, and most preferably 0.9 ppm or less.
[0039]
In addition to the above components, other components may be added as necessary within the range not impairing the properties of the glass of the present invention, but V, Cr, Mn, Fe, Co, Ni, Cu, excluding Ti, may be added. Each of the transition metal components such as Ag and Mo is colored even when contained in a small amount by combining them individually or in combination, and causes absorption at a specific wavelength in the visible range. In glass, it is preferable not to contain substantially.
[0040]
In addition, since each rare earth component except Lu and Gd is contained alone or in combination, absorption at a specific wavelength in the visible range due to coloring tends to occur or devitrification tends to increase. It is preferably not included.
Lu is a component that can be used arbitrarily when adjusting the optical constants of glass.₂O_ThreeIf it exceeds 3%, the devitrification resistance tends to decrease. Therefore, it is preferably 3% or less, more preferably 2.5% or less, and most preferably not contained if possible.
[0041]
The Th component can be included for the purpose of increasing the refractive index or the stability of the glass, and the Cd and Tl components can be included for the purpose of reducing the glass transition point (Tg). However, on the other hand, Pb, Th, Cd, Tl, and Os components tend to refrain from being used as harmful chemical substances in recent years, leading to not only the glass manufacturing process but also the processing process and disposal after commercialization. Therefore, it is preferable not to include substantially when the environmental impact is important.
[0042]
Since PbO has a large specific gravity, if glass containing it is used as a lens or the like, it is an obstacle to the weight reduction of optical equipment that is currently advancing rapidly. Furthermore, lead produces, processes, and disposes of glass. It is necessary to take measures for environmental measures at the time of carrying out, and the cost for that needs to be taken. Therefore, the glass of the present invention should not contain PbO.
[0043]
As₂O_ThreeIs a component that is used to improve the blowing of bubbles (defoaming properties) when melting glass, but it is necessary to take environmental measures when manufacturing, processing, and disposing of glass. In the glass of the present invention, As₂O_ThreeIt is not preferable to contain.
[0044]
Regarding the bubble evaluation, the larger the grade, the more the bubble generates light scattering, which is not preferable for use as a lens of an optical instrument. For these reasons, it is preferably grade 1 to grade 4, more preferably grade 1 to grade 3, and most preferably grade 1 to class 2.
[0045]
Regarding the evaluation of foreign matter, the larger the grade, the more the foreign matter scatters light, which is not preferable for use as a lens of an optical instrument. For these reasons, it is preferably grade 1 to grade 4, more preferably grade 1 to grade 3, and most preferably grade 1 to class 2.
[0046]
For striae evaluation, the higher the grade, the more difficult it is to obtain a homogeneous glass, so in optical glass where homogeneity is important, this is not preferred, and the glass of striae grade 1 to 4 is It can be used as a lens of an optical instrument. For these reasons, it is preferably grade 1 to grade 4, more preferably grade 1 to grade 3, and most preferably grade 1 to class 2.
[0047]
【Example】
The composition of Examples (No. 1 to No. 48) of the optical glass of the present invention is expressed by B value in the refractive index (nd), Abbe number (νd), ISO color characteristic index (ISO / CCI) of these glasses. The G value and the R value when O is 0 are obtained to the second decimal place, and are shown in Tables 1 to 10 together with the foam evaluation result (class) and the foreign substance evaluation result (class) striae evaluation.
In addition, this invention is not limited only to these Examples.
[0048]
Glasses 1-48 of the examples of the present invention are the ratios of the compositions of the examples shown in Tables 1 to 10 for ordinary optical glass raw materials such as oxides, carbonates, nitrates, phosphates, fluorides, etc. After being weighed and mixed, ordinary optical glass raw materials are put into a quartz crucible, and after rough melting, put into a platinum crucible. Depending on the meltability depending on the glass composition, 1 It was obtained by melting, clarifying and stirring for ˜4 hours, then casting into a mold and slow cooling.
[0049]
For the samples for striae evaluation of the glasses of Examples 1 to 46, the coarsely melted glass lump was dr. Hansbach, editor, Low Thermal Expansion Glass Ceramics (Springer-Verlag Berlin Heidelberg Printed in Germany 1995), platinum alloyed in accordance with the method introduced in FIG. And a part or all in contact with the molten glass is obtained by melting at 850 to 1300 ° C. and slowly cooling in an apparatus formed of platinum or a platinum alloy.
[0050]
In addition, with respect to the samples for striae evaluation of the glasses of Examples 47 and 48, a coarsely melted glass lump in a crucible (for example, quartz) made of a material containing no platinum is disclosed in Japanese Patent Publication No. 43-12885 and Dr. In accordance with the method described in Hans Bach, editor, Low Thermal Expansion Glass Ceramics (Springer-Verlag Berlin Heidelberg Printed in Germany 1995), 132, or a part of platinum in contact with molten glass or platinum in contact with platinum. It was obtained by melting at 850 to 1300 ° C. and slow cooling in an apparatus. In addition, the samples for striae evaluation of the glasses of Examples 47 and 48 were prepared by the same method as the samples for striae evaluation of the glasses of Examples 1 to 46, but the evaluation results of the striae did not change It was.
[0051]
Comparative Examples A to I shown in Tables 11 to 12 are shown in Example 3 described in JP-A-5-270853, Example 4 described in JP-A-5-270853, and JP-A-9-188540. Example 7 described in Example 12, Example 12 described in Japanese Patent Application Laid-Open No. 2001-58845, Example 27 described in Japanese Patent Application Laid-Open No. 52-133201, Example 38 described in Japanese Patent Application Laid-Open No. 2002-173336, Glasses of Example 33 described in Japanese Patent Application Laid-Open No. 2002-173336, Example 4 described in Japanese Patent Application Laid-Open No. 2002-201041, and Example 3 described in Japanese Patent Application Laid-Open No. 54-1212915 are shown as comparative examples. It was. The properties of these glasses were measured in the same manner as in the examples.
[0052]
Also for the glass of these comparative examples, ordinary optical glass raw materials were weighed and mixed so as to have a composition ratio of each comparative example shown in Tables 11 to 12, and then the normal optical glass raw material was put into a quartz crucible. After being melted and roughly melted, it is poured into a platinum crucible, and melted, clarified and stirred at 850 ° C to 1300 ° C for 1 to 4 hours according to the meltability of the glass composition, then cast into a mold and gradually cooled. It is a thing. However, as described above, the composition of the comparative example (No. B) was not vitrified.
[0053]
In the refractive index (nd), Abbe number (νd), and ISO color characteristic index (ISO / CCI) of the comparative glass (No. A to I, except that B was not vitrified), the B value was 0. The G value and R value were calculated to the second decimal place, and were shown together with the bubble evaluation result (class) and the foreign substance evaluation result (class).
[0054]
Foam evaluation is based on the Japan Optical Glass Industry Association Standard JOGIS12-¹⁹⁹⁴Performed according to “Measurement method of bubbles in optical glass” and based on Table 1 of the above standard, the sum of the cross-sectional areas of bubbles in 100 ml glass (mm²). For class 1, the total cross-sectional area of bubbles is 0.03 mm²Less than, grade 2 is 0.03-0.1mm²Less, grade 3 is 0.1 to 0.25 mm²Less than, grade 4 is 0.25-0.5mm²Less than, Class 5 is 0.5mm²That's all.
[0055]
Foreign matter evaluation is based on Japan Optical Glass Industry Association Standard JOGIS13-¹⁹⁹⁴The total cross-sectional area of the foreign matter in 100 ml of glass (mm) based on “Measurement method of foreign matter in optical glass” and based on Table 1 of the above standard²). The foreign substances referred to in the above standards are microcrystals such as devitrification, platinum fistula (platinum microcrystals), microbubbles, and foreign substances equivalent thereto. Class 1 has a total cross-sectional area of foreign matter of 0.03mm²Less than, grade 2 is 0.03-0.1mm²Less, grade 3 is 0.1 to 0.25 mm²Less than, grade 4 is 0.25-0.5mm²Less than, Class 5 is 0.5mm²It is the above glass.
[0056]
Here, the striae evaluation is performed by the Japan Optical Glass Industry Association Standard JOGIS11-¹⁹⁷⁵This is a result obtained by classifying the degree of striae based on Table 2 of the above standard, which is performed by “Measurement method of striae of optical glass”. As the measurement sample, a glass having a size of 50 × 50 × 20 mm and polished on both sides of 50 × 20 mm in parallel is used. Grade 1 has no striae. Class 2 is the thin and dispersed striae that is visible. Class 3 has slight striae parallel to the direction perpendicular to the polished surface. Class 4 has more striae parallel to the direction perpendicular to the polishing surface than class 3 or has deep parallel striae.
[0057]
The ISO color characteristic index (ISO / CCI) was measured as follows. First, the obtained glass bulk material was used as a sample having a thickness of 10 ± 0.1 mm with the opposite surfaces polished in parallel, and immediately after annealing, JOGIS02-¹⁹⁷⁵The light transmittance (spectral transmittance) was measured by the method defined in 1. Then, the light transmittance of the glass bulk material at 350 to 680 nm is replaced with the spectral transmittance of the lens, and is defined in JIS B 7097 (How to represent color characteristics for photography by ISO color characteristic index (ISO / CCI)). The ISO color characteristic index (ISO / CCI) is calculated and the ISO color characteristic index (ISO / CCI) of the glass bulk material is used. The G value (green) and R value (red) when B (blue) is 0 are calculated. I asked to the second decimal place.
[0058]
About the refractive index (nd) and Abbe number ((nu) d) of the glass of an Example and a comparative example, it measured about the glass obtained by making a slow cooling temperature-fall rate into 25 degreeC / Hr.
[0059]
FIG. 1 [a diagram in which ISO / CCI (G value) -nd is plotted] shows the ISO / CCI value (G value) and the coordinates of nd indicated by the glass of the above Examples (Nos. 1 to 48) with ◯ marks. Similarly, the above comparative examples (No. A to F) are indicated by x and the comparative composition examples (No. G to I) are indicated by ■. Further, PBH6W and PBH53W (both OHARA glass type names) are indicated by ●.
[0060]
FIG. 2 [a diagram in which ISO / CCI (R value) -nd is plotted] shows the ISO / CCI value (R value) and the coordinates of nd indicated by the glass of the above-mentioned examples (No. 1 to 48) with ◯ marks. Similarly, the above comparative examples (No. A to F) are indicated by x and the comparative composition examples (No. G to I) are indicated by ■. Further, PBH6W and PBH53W (both OHARA glass type names) are indicated by ●.
[0061]
[Table 1]

[0062]
[Table 2]

[0063]
[Table 3]

[0064]
[Table 4]

[0065]
[Table 5]

[0066]
[Table 6]

[0067]
[Table 7]

[0068]
[Table 8]

[0069]
[Table 9]

[0070]
[Table 10]

[0071]
[Table 11]

[0072]
[Table 12]

[0073]
High refractive index, high dispersion optical glass contains many components that have absorption in the short wavelength region of visible light, and the higher the refractive index of the glass, the higher the light reflectance on the glass surface. There is a tendency that the light transmittance including the above becomes worse. Therefore, the G and R values of the ISO color characteristic index tend to increase as the refractive index of the glass increases. As for PBH53W and PBH6W, which are glasses that contain a large amount of Pb components that have been manufactured and / or sold in the past, the ISO / CCI value increases as nd increases as shown by the ● marks in FIGS. There is a tendency to grow.
[0074]
As shown in Tables 1 to 12 and FIGS. 1 and 2, the glass of Examples (No. 1 to 48) according to the present invention is all compared to the glass of Comparative Examples (No. A to F). ISO / CCI G and R values are small, and excellent transmittance, that is, internal transmittance can be obtained in a short wavelength region. Moreover, although the G / R values of ISO / CCI are low in Comparative Examples (G to I), the number of optically inhomogeneous portions is remarkably large, so the internal quality is poor, and it can be used as a lens or the like for optical equipment. Have difficulty.
Moreover, all the glasses of Examples 1 to 48 show excellent internal quality, and have lower internal ISO quality and lower ISO / CCI than the glasses of Comparative Examples A to I. Excellent light transmittance can be obtained in the value, that is, in the short wavelength region.
[0075]
【The invention's effect】
As described above, the optical glass of the present invention has a specific range of P.₂O_Five-Nb₂O_Five-BaO-Na₂It is an O-based glass and exhibits excellent transmittance and internal transmittance in the short wavelength region in an optical constant within a predetermined range. Therefore, ISO / CCI values (G and R values) are low, and costs are reduced for environmental measures. PbO and As₂O_ThreeIn addition, it is possible to obtain a glass having excellent internal quality.
Furthermore, Gd₂O_ThreeBy adding the above, it is possible to obtain a high refractive index and high dispersibility optical glass having excellent devitrification resistance and further excellent internal quality.
Further, since the glass transition point (Tg) can be lowered, so-called mold press, a glass for precision presses that can be used as an optical element such as a lens as it is without requiring grinding or polishing after press molding. It is also suitable as a glass for use.
[0076]
[Brief description of the drawings]
[Fig. 1] JOGIS02-¹⁹⁷⁵ISO color characteristic index defined by JIS 7097 (how to express color characteristics for photography by ISO color characteristic index (ISO / CCI)) calculated from the light transmittance of a glass bulk material of 350 nm to 680 nm defined in ISO / CCI) XY Cartesian coordinates plotting the G value [calculated to the second decimal place] as the X axis and the refractive index (nd) as the Y axis.
[Figure 2] JOGIS02-¹⁹⁷⁵ISO color characteristic index defined by JIS 7097 (how to express color characteristics for photography by ISO color characteristic index (ISO / CCI)) calculated from the light transmittance of a glass bulk material of 350 nm to 680 nm defined in ISO / CCI) XY orthogonal coordinates plotting the R value [calculated to the second decimal place] as the X axis and the refractive index (nd) as the Y axis.

Claims (14)

In mass percentage,
P ₂ O ₅ 15~35%,
Nb ₂ O ₅ 40-60%,
Na ₂ O 0.5 to less than 15%,
BaO 3 to less than 25%,
TiO ₂ 0-2.6%
And (BaO + Nb ₂ O ₅ ) / {(TiO ₂ + WO ₃ ) × 3 + Bi ₂ O ₃ + Nb ₂ O ₅ }> 1.0 in a mass percentage ratio
, And the addition free of TeO ₂ and lead component and arsenic components, the refractive index (nd) of 1.78 to 1.90, optical glass the Abbe number ([nu] d) is characterized in that it is a 18 to 27. In mass percentage,
Gd ₂ O ₃ 0~5% and / or _K 2 O 0% and / or _Li 2 O 0% and / or _Bi 2 _O 3 _0~5% and / or 0% MgO and / or CaO 0% and / or SrO 0% and / or 0 to 3% ZnO and / or _SiO 2 0 to 5% and / or _B 2 _O 3 0~5% and / or _Al 2 _O 3 0 to 4% and / or _Ta 2 _O 5 0 to 5% and / or _ZrO 2 0 to 3% and / or WO ₃ 0 to 8% and / or _Sb 2 _O 3 _0~0.02%
The optical glass according to claim 1, comprising: Japanese Optical Glass Industrial Standard JOGIS02- ¹⁹⁷⁵ X axis ISO color characteristic exponent G value calculated using the spectral transmittance of a glass material obtained by (Measurement method of coloration degree of the optical glass), refractive index (nd) Y In the XY orthogonal coordinate diagram using the axis, the ISO color characteristic index G value is smaller and the refractive index (nd) is higher than the straight line (SL3-G): Y = 0.0277X + 1.725, and , X axis ISO color characteristic index R value calculated using the spectral transmittance of the glass bulk as determined by Japanese optical glass industrial standard JOGIS02- ^1975, refractive index (nd) of the Y-axis and the X-Y orthogonal coordinate graph , The ISO color characteristic index R value is smaller and the refractive index (nd) is higher than the straight line (SL3-R): Y = 0.0273X + 1.7102. The optical glass according to claim 1 or 2. The sum of the cross-sectional areas of bubbles in the glass in 100ml shown in Table 1 of the Japan Optical Glass Industry Society Standard JOGIS12- ¹⁹⁹⁴ (method of measuring froth optical glass) is of Class 1 Class 4, and Nippon Kogaku claim the sum of the cross sectional area of the foreign matter in the glass in a 100ml shown in Table 1 glass industrial standard JOGIS13- ¹⁹⁹⁴ "method of measuring foreign matter optical glass" is characterized in that it is a grade 1 class 4 Optical glass as described in any one of 1-3. Japanese Optical Glass Industrial Standard JOGIS02- ¹⁹⁷⁵ X axis ISO color characteristic exponent G value calculated using the spectral transmittance of a glass material obtained by (Measurement method of coloration degree of the optical glass), refractive index (nd) Y In the XY orthogonal coordinate diagram as the axis, the ISO color characteristic index G value is smaller and the refractive index (nd) is higher than the straight line (SL5-G): Y = 0.0329X + 1.7174, and , X axis ISO color characteristic index R value calculated using the spectral transmittance of the glass bulk as determined by Japanese optical glass industrial standard JOGIS02- ^1975, refractive index (nd) of the Y-axis and the X-Y orthogonal coordinate graph , The ISO color characteristic index R value is smaller and the refractive index (nd) is higher than the straight line (SL5-R): Y = 0.0288X + 1.713. The optical glass according to any one of claims 1 to 4. In mass percentage,
P ₂ O ₅ 15~35%,
Nb ₂ O ₅ 40-60%,
Na ₂ O 0.5 to less than 15%,
BaO 3 to less than 25%,
Wherein the further _Gd 2 _O 3 _0~4% and / or _K 2 O _0~6% and / or _Li 2 O _0~6% less and / or _Bi 2 _O 3 _0~5% less and / or MgO 0 less 10% less and / or CaO 0% and / or SrO 0% and less than / or 0 to 3% ZnO and / or _SiO 2 0 to less than 5% and / or _B 2 _O 3 0 to 5 % less and / or _Al 2 _O 3 0 to 4% and / or _Ta 2 _O 5 0 to 5% and / or _ZrO 2 0 to 3% and / or _Sb 2 _O 3 0 to 0.02% and / or WO _{30 to} 8% and / or a total of 0 to 5% of the fluoride in which a part or all of the metal oxide is substituted as F (fluorine),
And in the ratio of mass percentage, (BaO + Nb ₂ O ₅ ) / {(TiO ₂ + WO ₃ ) × 3 + Bi ₂ O ₃ + Nb ₂ O ₅ }> 1.0
The optical glass according to claim 1 , wherein the optical glass is an optical glass. _P 2 _O 5 _15~35% in percent by mass,
Nb ₂ O ₅ 40-60%,
Na ₂ O 0.5 to less than 15%,
BaO 3 to less than 25%, further Gd ₂ O ₃ 0.1 to 4% and / or K ₂ O 0 to 6% and / or Li ₂ O 0 to less than 6% and / or Bi ₂ O ₃ 0 to less than 4.5% and / or MgO less than 0-10% and / or CaO 0-10% less than and / or SrO 0-10% less than and / or 0 to 3% ZnO and / or _SiO 2 less than 0-5% And / or B ₂ O ₃ less than 0-5% and / or Al ₂ O ₃ 0-4% and / or Ta ₂ O ₅ 0-5% and / or ZrO ₂ 0-3% and / or Sb ₂ O ₃ 0 to 0.01% and / or WO ₃ 0 to 8% and / or fluoride in which a part or all of the above metal oxide is substituted include 0 to 5% in total amount as F (fluorine),
And in the ratio of mass percentage, (BaO + Nb ₂ O ₅ ) / {(TiO ₂ + WO ₃ ) × 3 + Bi ₂ O ₃ + Nb ₂ O ₅ }> 1.0
The optical glass according to claim 1 , wherein the optical glass is an optical glass. Japanese Optical Glass Industrial Standard JOGIS02- ¹⁹⁷⁵ X axis ISO color characteristic exponent G value calculated using the spectral transmittance of a glass material obtained by (Measurement method of coloration degree of the optical glass), refractive index (nd) Y In the XY orthogonal coordinate diagram using the axis, the ISO color characteristic index G value is smaller and the refractive index (nd) is higher than the straight line (SL8-G): Y = 0.0329X + 1.7245, and the refractive index (nd) is high. , X axis ISO color characteristic index R value calculated using the spectral transmittance of the glass bulk as determined by Japanese optical glass industrial standard JOGIS02- ^1975, refractive index (nd) of the Y-axis and the X-Y orthogonal coordinate graph , The ISO color characteristic index R value is smaller and the refractive index (nd) is higher than the straight line (SL8-R): Y = 0.0288X + 1.7208. Any optical glass according to one of Motomeko 1-7. _P 2 _O 5 _15~30% in percent by mass,
Nb ₂ O ₅ 42-60%,
Na ₂ O less than 0.5-10%,
BaO 5 to less than 25%,
In addition,
Gd ₂ O ₃ 0.1~4% and / or _K 2 O _0~6% and / or _Li 2 O 0 to 2% and / or _Bi 2 _O 3 less than 0 to 4.5% and / or MgO 0 to Less than 10% and / or CaO 0 to less than 10% and / or SrO 0 to less than 10% and / or ZnO 0 to 3% and / or SiO ₂ less than 0.1 to 4% and / or B ₂ O ₃ . less than 2-5% and / or _Al 2 _O 3 _0~4% and / or _Ta 2 _O 5 _0~5% and / or _ZrO 2 0 to 3% and / or _Sb 2 _O 3 _0~0.01% and And / or WO ₃ 0 to 5% and / or 0 to 5% in terms of the total amount of F (fluorine) as a fluoride in which a part or all of the metal oxide is substituted
And in a mass percentage ratio (BaO + Nb ₂ O ₅ ) / {(TiO ₂ + WO ₃ ) × 3 + Bi ₂ O ₃ + Nb ₂ O ₅ }> 1.1
The optical glass according to claim 1 , wherein the optical glass is a glass. _P 2 _O 5 _15~35% in percent by mass,
Nb ₂ O ₅ 40-60%,
Gd ₂ O ₃ 0.1-4%,
Na ₂ O less than 0.5-10%,
K ₂ O 0-6%,
However, the total amount of Na ₂ O and K ₂ O is less than 0.5 to 10%,
Bi ₂ O ₃ 0 to less than 5%,
MgO 0 to less than 10%,
CaO 0 to less than 10%,
SrO 0 to less than 10%,
BaO 0.5 to less than 25%,
ZnO 0-3%,
SiO ₂ 0 to less than 5%,
B ₂ O ₃ 0.2 to less than 5%,
Al ₂ O ₃ 0-3%,
Ta ₂ O ₅ 0-5%,
ZrO ₂ 0-3%,
Sb ₂ O ₃ 0-0.03%
And a fluoride in which a part or all of the above metal oxide is substituted contains 0 to 5% in total as F (fluorine), does not contain lead, TeO ₂ , WO ₃ and TiO ₂ , and has a refractive index (nd ) Has an optical constant in the range of 1.78 to 1.90, and the Abbe number (νd) in the range of 18 to 27. _P 2 _O 5 _15~30% in percent by mass,
Nb ₂ O ₅ 42-60%,
Gd ₂ O ₃ 0.1-4%,
Na ₂ O 0.5~9.6%,
K ₂ O 0-6%,
However, the total amount from 0.5 to 9.6% of Na ₂ O and _{K 2} O,
Bi ₂ O ₃ 0-4.5%,
MgO 0 to less than 10%,
CaO 0 to less than 10%,
SrO 0 to less than 10%,
BaO 0.5 to less than 25%,
ZnO 0-3%,
SiO ₂ 0.1 to less than 4%,
B ₂ O ₃ 0.2 to less than 5%,
Al ₂ O ₃ 0-3%,
Ta ₂ O ₅ 0-5%,
ZrO ₂ 0-3%,
Sb ₂ O ₃ 0-0.03%
And a fluoride in which a part or all of the metal oxide is substituted is contained in an amount of 0 to 5% in terms of F (fluorine), does not contain lead component, TeO ₂ , WO ₃ component and TiO ₂ component, and is refracted An optical glass characterized by an optical constant having a ratio (nd) in the range of 1.78 to 1.90 and an Abbe number (νd) in the range of 18 to 27. The sum of the cross-sectional areas of bubbles in the glass in 100ml shown in Table 1 of the Japan Optical Glass Industry Society Standard JOGIS12- ¹⁹⁹⁴ "method of measuring froth optical glass" is of Class 1 Class 3, and, Nippon Kogaku the sum of the cross-sectional areas of the foreign matter in the glass in a 100ml shown in Table 1 glass industrial standard JOGIS13- ¹⁹⁹⁴ "method of measuring foreign matter optical glass" is of class 1 class 3, and the Japanese optical glass industrial any one of claims 1 to 11, the degree of meeting standards JOGIS11- ¹⁹⁷⁵ striae shown in Table 2 of "method of measuring striae of optical glass" is characterized in that it is a primary to tertiary grade The optical glass described in 1. The extent of striae which are shown in Table 2 of the Japan Optical Glass Industry Association Standard JOGIS11- ¹⁹⁷⁵ "method of measuring striae of optical glass" is a grade 1 or grade 2, Japan Optical Glass Industry Association standard JOGIS12- ¹⁹⁹⁴ the sum of the cross-sectional areas of bubbles in the glass in 100ml shown in Table 1 in "method of measuring froth optical glass" is grade 1 or grade 2, and Japanese optical glass industrial standard JOGIS13- ¹⁹⁹⁴ "optical to any one of claims 1 to 12, characterized in that the sum of the cross-sectional areas of the foreign matter in the glass in 100ml shown in Table 1 of the measurement method "the glass of the foreign matter is grade 1 or grade 2 The optical glass described. Refractive index (nd) is 1.80-1.85, Abbe number ((nu) d) is 23.8-25.7, Optical glass as described in any one of Claims 1-13.

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