JP2022501303A - Optical glass, preforms, optical elements and their optical equipment - Google Patents

Abstract

Optical glass has 0 to 10% SiO2, 5 to 25% B2O3, 0 to 15% ZrO2, 10 to 25% ZnO, 2 to 30% TiO2 + Nb2O5 + WO3, and 30 to 30% by weight. It contains 55% Ln2O3, said Ln2O3 is the total content of La2O3, Gd2O3, Y2O3, and Yb2O3, B2O3 / Ln2O3 is 0.3-0.8, and Y2O3 / B2O3 is 0.15. ~ 2. Optical glass has a refractive index (nd) of 1.84 to 1.87 and an Abbe number (vd) of 38 to 41, while having excellent devitrification resistance and degree of foaming, and being chemically stable. Highly sex.

Description

The present invention belongs to the field of optical glass, and particularly relates to optical glass, preforms, optical elements and optical instruments thereof.

Optical glass can be used in the manufacture of lenses, prisms, and reflectors for optical instruments, and all components made from optical glass are important elements of optical equipment. Optical glasses with a refractive index (nd) of 1.84 to 1.87 and an Abbe number (vd) of 38 to 41 have excellent transmissivity and high refractive index, which makes them suitable for cameras, telescopes, microscopes, and other precision optics. Widely applied in the manufacture of equipment lenses. In recent years, there has been a tendency to realize small and lightweight optical devices, and aspherical lenses have been used to reduce the number of optical elements. On the other hand, market demand is also increasing.

However, aspherical lenses are expensive and complicated to operate according to conventional methods of hot press molding, then polishing, grinding, and remanufacturing of molten glass. Accurate molding is a method of manufacturing an optical element made of optical glass, which is easy to operate and low in cost. However, aspheric lenses manufactured by this method have high requirements for the properties of the glass material, i.e., to easily achieve accurate molding, high devitrification resistance, low melting point, and excellent foam degree. Is required. When the optics are used in digital cameras, vidicons, and other outdoor photographic equipment, the optical glass material is further water or acid in the outdoor environment to ensure the service quality and longevity of the lens. It is necessary to have excellent chemical stability to withstand corrosion such as. Also, for optical instruments operated at special temperatures, the glass material needs to have a better coefficient of thermal expansion in order to reduce the degree of expansion and contraction of the glass when the temperature changes.

Patents CN104803600A, CN104098627A, and CN105891682A provide optical glasses having the same or similar refractive index (nd) and Abbe number (vd) as the present invention, respectively, but cannot meet other requirements.

From the viewpoint of lack of prior art, it is an object of the present invention to provide an optical glass having a refractive index (nd) of 1.84 to 1.87 and an Abbe number (vd) of 38 to 41. Optical glass is easy to press-mold with precision, has high devitrification resistance, has a high degree of foaming, has high chemical stability, and is low in cost.

The present invention further provides preforms, optical elements, and optical instruments made from the optical glass.

The technical solutions applied to achieve that goal are:

Optical glass, in weight percent, 0 to 10% SiO _2, 5 to 25% _B 2 _{O 3,} 0 to 15 percent of ZrO _2, 10 to 25 percent of ZnO, 2 to 30% of the TiO _It contains 2 + Nb ₂ O ₅ + WO ₃ and 30-55% Ln ₂ O ₃ , where Ln ₂ O ₃ is La ₂ O ₃ , Gd ₂ O ₃ , Y ₂ O ₃ and Yb ₂ O _3. a total content _{of, B 2 O 3 / Ln 2} O 3 is _{0.3~0.8, Y 2 O 3 / B} 2 O 3 is 0.15 to 2.

Further, the optical glass contains 0 to 10% RO, 0 to 10% Rn ₂ O, and 0 to 1% clearing agent by weight percentage, and RO is MgO, CaO, SrO. , Or one or more of BaO, Rn ₂ O is _{one or more of Li 2} O, Na ₂ O, and K ₂ O, and the clarifying agent is one or more of Sb ₂ O ₃ , SnO _{2, and} CeO _2. Is.

Optical glass, in weight percent, 0 to 10% SiO _2, 5 to 25% _B 2 _{O 3,} 0 to 15 percent of ZrO _2, and 10% to 25% of ZnO, of 2-30% Contains TiO ₂ + Nb ₂ O ₅ + WO ₃ , 30-55% Ln ₂ O ₃ , 0-10% RO, 0-10% Rn ₂ O, and 0-1% clarifier. Ln ₂ O ₃ is _{the total content of La 2} O ₃ , Gd ₂ O ₃ , Y ₂ O ₃ , and Yb ₂ O ₃ , and RO is one or more of MgO, CaO, SrO, or BaO. Yes, Rn ₂ O is _{one or more of Li 2} O, Na ₂ O, K ₂ O, the clarifying agent is one or more of Sb ₂ O ₃ , SnO _{2, and} CeO ₂ , and B ₂ O ₃ / Ln. ₂ O ₃ is 0.3 to 0.8, and Y ₂ O ₃ / B ₂ O _{3 is 0.15 to 2.}

Further, according to the optical glass, the content of all the components satisfies one or more of the following four conditions.

1) SiO ₂ / (SiO ₂ + B ₂ O ₃ ) is 0 to 0.25.

2) Y ₂ O ₃ / Ln ₂ O ₃ is 0.08 to 0.45.

3) Y ₂ O ₃ / Gd ₂ O ₃ is 0.3 to 3.

4) Y ₂ O ₃ / (SiO ₂ + B ₂ O ₃ ) is 0.16 to 0.8.

Further, according to the optical glass, SiO ₂ is 1 to 8%, and / or B ₂ O ₃ is 10 to 23%, and / or gZrO ₂ is 1 to 10%, and / or ZnO is 10 to 20%. And / or TiO ₂ + Nb ₂ O ₅ + WO ₃ 4-22%, and / or Ln ₂ O ₃ 35-52%, and / or RO 0-5%, and / or R ₂ O 0-5. % And / or the clarifying agent is 0 to 0.5%.

Further, according to the optical glass, the content of all the components satisfies one or more of the following six conditions.

1) SiO ₂ / (SiO ₂ + B ₂ O ₃ ) is 0.05 to 0.23.

2) Y ₂ O ₃ / Ln ₂ O ₃ is 0.1 to 0.4.

3) Y ₂ O ₃ / Gd ₂ O ₃ is 0.5 to 2.5.

4) Y ₂ O ₃ / (SiO ₂ + B ₂ O ₃ ) is 0.2 to 0.7.

5) B ₂ O ₃ / Ln ₂ O ₃ 0.3 to 0.6.

6) Y ₂ O ₃ / B ₂ O ₃ is 0.2 to 1.5.

Further, according to the optical glass, 1 to 4% SiO ₂ and / or B ₂ O ₃ is 15 to 20%, and / or ZrO ₂ is 2 to 6%, and / or ZnO is 13 to 17%. And / or TiO ₂ + Nb ₂ O ₅ + WO ₃ is 10 to 18%, and / or Ln ₂ O ₃ is 40 to 50%.

Further, according to the optical glass, the content of all the components satisfies one or more of the following six conditions.

1) SiO ₂ / (SiO ₂ + B ₂ O ₃ ) is 0.08 to 0.2.

2) Y ₂ O ₃ / Ln ₂ O ₃ is 0.1 to 0.3.

3) Y ₂ O ₃ / Gd ₂ O ₃ is greater than 1 and less than or equal to 2.

4) Y ₂ O ₃ / (SiO ₂ + B ₂ O ₃ ) is 0.3 to 0.6.

5) B ₂ O ₃ / Ln ₂ O ₃ is 0.3 to 0.5.

6) Y ₂ O ₃ / B ₂ O ₃ is 0.3 to 1.

Further, according to the optical glass, Nb ₂ O ₅ is 1 to 15%, and / or WO ₃ is 1 to 15%, and / or TIO ₂ is 0 to 10%, and / or La ₂ O ₃ is 20. ~ 45% and / or Gd ₂ O ₃ is 0 to 15%, and / or Y ₂ O ₃ is 1 to 15%, and / or Yb ₂ O ₃ is 0 to 5%.

Further, according to the optical glass, Nb ₂ O ₅ is 2 to 10%, and / or WO ₃ is 2 to 12%, and / or TIO ₂ is 0 to 5%, and / or La ₂ O ₃ is 25. ~ 40% and / or Gd ₂ O ₃ is 1-10%, and / or Y ₂ O ₃ is 3-15%.

Further, according to the optical glass, Nb ₂ O ₅ is 4 to 8%, and / or WO ₃ is 6 to 10%, and / or La ₂ O ₃ is 30 to 35%, and / or Gd ₂ O _3. Is 3-7% and / or Y ₂ O ₃ is 6-10% and / or TiO ₂ is not included.

Further, according to the optical glass, the refractive index (nd) is 1.84 to 1.87, preferably 1.85 to 1.86, and the Abbe number (vd) is 38.0 to 41.0. It is preferably 38.5 to 40.0.

Further, according to the optical glass, the durability ( _DW ) of water by the powder method of the optical glass is grade 2 or higher, preferably grade 1. Acid resistance by a powder method (D _A) is grade 3 or more, preferably grade 2. The degree of foam is grade A or higher, preferably grade _A0 or higher.

Further, according to the optical glass, the coefficient of thermal expansion (α _{-30 ° C to 70 ° C} ) is 75 × 10 ^-7 / K or less, preferably 70 × 10 ^-7 / _{K for α -30 ° C to 70 ° C.} It is K or less. The conversion temperature (Tg) is 640 ° C. or lower, preferably 630 ° C. or lower, and more preferably 625 ° C. or lower. The upper limit of the crystallization temperature of the optical glass is 1,250 ° C. or lower, preferably 1,200 ° C. or lower, and more preferably 1,180 ° C. or lower.

The glass preform is made of the optical glass.

The optical element is made of the optical glass or the glass preform.

The optical device is manufactured from the optical element.

The high refraction and low dispersion glass material provided by the present invention has excellent devitrification resistance, is easy to perform precision press molding, suppresses the content of expensive raw materials such as rare earth oxides, and is cost effective. Lower. Therefore, it is suitable for promotion and application in the precision press forming process. On the other hand, in order to improve the production of the product, the chemical stability of the glass and the degree of foaming are improved by the ratio of reasonable components in the present invention. Some preferred technical solutions are to further optimize the proportions of components, reduce the coefficient of thermal expansion, optimize crystallization resistance and enhance the chemical stability of the glass. In order to manufacture an optical element and an optical instrument having better manufacturing quality and a longer service life, a glass material having high cost performance is provided.

Optical glass

The following paragraphs detail the composition of the optical glass provided by the present invention. Unless otherwise specified, the content and total content of all glass compositions means weight content expressed in% by weight. % By Weight is the weight of a particular component or percentage of the total weight of some compositions that make up the total weight of the optical glass. The ratio of all glass compositions or the ratio of the sum of some compositions is the ratio of the corresponding weight content or the sum of the weight content thereof.

The optical glass provided by the present invention has the optical properties required for a lens material for manufacturing precision instruments, has a refractive index (nd) of 1.84 to 1.87, and has an Abbe number (vd). 38-41. It is easy to precision press and has excellent chemical stability and foaming degree. Optical glass, in weight percent, 0 to 10% SiO _2, 5 to 25% _B 2 _{O 3,} 0 to 15 percent of ZrO _2, and 10% to 25% of ZnO, of 2-30% It _{contains TiO 2} + Nb ₂ O ₅ + WO ₃ and 30-55% Ln ₂ O ₃ , where Ln ₂ O ₃ is La ₂ O ₃ , Gd ₂ O _3, Y ₂ O _3, and Yb ₂ O. a total content of _{3, B 2 O 3 / Ln} 2 O 3 is _{0.3~0.8, Y 2 O 3 / B} 2 O 3 is 0.15 to 2.

B ₂ O ₃ is a component of the glass network shape capable of improving the meltability and devitrification resistance of the glass. In order to achieve the above effects, 5% or more of B ₂ O ₃ , preferably 10% or more of B ₂ O ₃ , and more preferably 15% or more of B ₂ O ₃ are introduced. If the amount introduced is higher than 25%, the stability of glass molding is lowered and the refractive index is also lowered. Therefore, _{the upper limit of the content of B 2} O ₃ is set to 25%, preferably 23%, and more preferably 20%.

SiO ₂ is an arbitrary component of the present invention and is a component of the glass molding agent. SiO ₂ forms a three-dimensional network of very compact and solid silica tetrahedrons in the glass. This network is added to the glass to strengthen and increase the density of the loose boron oxide triangular network, thereby increasing the high temperature viscosity of the glass. Further, the _{higher the content of SiO 2,} the lower the coefficient of thermal expansion of the glass. _{The lower limit of the SiO 2} content in the optical glass provided by the present invention is 0%, preferably 1%. If the SiO ₂ content is too high, the conversion temperature of the glass rises, the meltability of the glass decreases, and the difficulty of processing increases. Therefore, the upper limit of the content is 10%, preferably 8%, and more preferably 4%.

SiO ₂ and B ₂ O ₃ are both components of the glass network shape. Through the research results, the present inventor has discovered that SiO ₂ / (SiO ₂ + B ₂ O ₃ ) affects the crystallization resistance performance and the coefficient of thermal expansion of glass under the formulation of the present invention. The _{higher the SiO 2} / (SiO ₂ + B ₂ O ₃ ) value, the lower the coefficient of thermal expansion of the glass, further contributing to the decrease in the sensitivity of the glass to temperature. However, on the other hand, the crystallization resistance performance of the glass deteriorates. Through research, in the formulations of the present invention, when the SiO ₂ / (SiO ₂ + B ₂ O ₃ ) value is in the range of 0 to 0.25, the coefficient of thermal expansion of the glass is made lower than ^{75 × 10 -7 / K.} Furthermore, it was discovered that the crystallization resistance was excellent. Further, the ratio is preferably in the range of 0.05 to 0.23, more preferably 0.08 to 0.2.

_{ZrO 2} as an optional component of the present invention is an oxide having high reflection and low dispersion, and may be added to the glass to improve the refractive index and adjust the dispersion of the glass. On the other hand, an approximate amount of ZrO ₂ may be added to the glass in order to improve crystallization resistance and chemical stability. However, when the content of the optical glass of the present invention is higher than 15%, it becomes difficult to melt, the melting temperature rises, foreign substances are easily mixed in the glass, and the transmittance decreases. Therefore, the content is set to 0 to 15%, preferably 1 to 10%, more preferably 2 to 6%.

ZnO can adjust the refractive index and dispersion of the glass, improve the crystallization resistance of the glass, lower the conversion temperature of the glass, and improve the chemical stability of the glass. In addition, ZnO can reduce the high temperature viscosity of the glass, and as a result, the glass can be melted at a lower temperature and the transmittance of the glass can be increased. However, when excess ZnO is added, the crystallization resistance of the glass deteriorates, and the relatively low high temperature viscosity causes difficulty in molding. Therefore, in the glass system provided by the present invention, the lower limit of the ZnO content is set to 10%, preferably 13%. The upper limit of the ZnO content is set to 25%, preferably 20%, more preferably 17%.

In order to enhance the stability of preventing crystallization of the glass, as an optional component, TiO ₂ capable of improving the refractive index of the glass may be added to the glass provided by the present invention. Further, Nb ₂ O ₅ and WO ₃ may be used instead to some extent. However, its excessive content causes a decrease in the transmittance of the glass. In the optical glass provided by the present invention, the TiO ₂ content is 0 to 10%, preferably 0 to 5%, and more preferably 0%.

Nb ₂ O ₅ is a component capable of improving the chemical stability and refractive index of glass. If the Nb ₂ O ₅ content is less than 1%, the optical constants do not reach the design requirements. When the content is higher than 15%, the devitrification resistance of the glass decreases. Therefore, the Nb ₂ O ₅ content is defined as 1-15%, preferably 2-10%, more preferably 4-8%.

WO ₃ is mainly used to maintain the optical constants of glass and improve the crystallization properties of glass, but if its content is too high, the transmittance of the glass will decrease and the degree of dyeing will increase. Crystallization properties deteriorate. Therefore, the WO ₃ content is preferably 1 to 15%, more preferably 2 to 12%, and even more preferably 6 to 10%.

TiO ₂ , Nb ₂ O ₅ , and WO ₃ are effective in improving the index of refraction and dispersion. Therefore, the optical glass provided by the present invention is required to have high reflection, low dispersion, and high transmittance, and _{the upper limit of TiO 2} + Nb ₂ O ₅ + WO ₃ is 30%, preferably 30%. It is set to 22%, more preferably 18%. However, if TiO ₂ + Nb ₂ O ₅ + WO ₃ is too low, the thermal stability and moldability of the glass deteriorate. Therefore, the lower limit is set to 2%, preferably 4%, and even more preferably 10%.

Rare earth oxides Ln ₂ O ₃ (La ₂ O _3, Gd ₂ O ₃ , Y ₂ O ₃ and Yb ₂ O ₃ ) are added because they are beneficial in improving the refractive index of glass. If the total content is less than 30%, the expected optical constants will not be obtained. However, when the total content is higher than 55%, the chemical stability and devitrification resistance of the glass are lowered, and the raw material cost of the glass is also increased. Therefore, _{Ln 2} O _3, which is the total content of _{La 2} O _3, Gd ₂ O ₃ , Y ₂ O _3, and Yb ₂ O ₃ , is 30 to 55%, preferably 35 to 52%, and more preferably 40 to. Set to 50%.

The rare earth oxide Ln ₂ O ₃ is dispersed in the glass network and is mainly used to improve the refractive index. However, the inventors of the present application, in the study, the ratio of B ₂ O ₃ and Ln ₂ O ₃ is a component of the glass network, and found a significant effect on the chemical stability of the glass. If B ₂ O ₃ / Ln ₂ O ₃ is less than 0.3, chemical stability, especially acid resistance, cannot meet the requirements. If B ₂ O ₃ / Ln ₂ O ₃ is higher than 0.8, the index of refraction decreases. According to the present invention, the range is set to 0.3 to 0.8, preferably 0.3 to 0.6, and more preferably 0.3 to 0.5.

_{La 2} O ₃ in the rare earth oxide is a component capable of improving the optical properties of the glass, but when the content thereof is higher than 45%, the devitrification resistance and meltability of the glass may deteriorate. _{Therefore, the La 2} O ₃ content provided by the present invention is preferably 20 to 45%, more preferably 25 to 40%, and even more preferably 30 to 35%.

_{Gd 2} O ₃ as an optional component may increase the index of refraction of the glass, but does not significantly improve the dispersion of the glass. According to the present invention, the Gd ₂ O ₃ provided by the present invention improves the stability of the glass, significantly enhances the chemical stability of the glass, maintains the refractive index, and causes an excessive increase in dispersion. Can be introduced to control. However, when the content is higher than 15%, the devitrification resistance of the glass decreases, but the glass density increases. _{Therefore, the Gd 2} O ₃ content provided by the present invention is 0 to 15%, preferably 1 to 10%, more preferably 3 to 7%.

Y ₂ O ₃ can maintain a high refractive index and Abbe number, suppress an increase in the cost of the glass material, improve the meltability and devitrification resistance of the glass, and upper the crystallization temperature and specific gravity of the glass. It is a component that can reduce. However, in the formulation of the present invention, when the content is higher than 15%, the chemical stability and devitrification resistance of the glass are lowered. _Thus, Y 2 _{O 3} content of from 1% to 15%, more preferably 15% to 3%, more preferably in the range of 6% to 10%.

Y ₂ O ₃ and other rare earth oxides can improve the refractive index of the glass. Also, its cost is _{lower than Gd 2} O ₃ , and its components are beneficial for weight reduction. Therefore, its components are introduced into the prior art. However, in the formulation system of the present invention, Y ₂ O ₃ content, not only affects the glass independently adjusting the plurality of characteristics of synergistically glass with a plurality of other components including the following.

When the optical glass provided by the present invention _{contains both Y 2} O ₃ and La ₂ O ₃ , the devitrification resistance of the glass can be effectively improved, and a glass element is made from a glass material. In some cases, precision press forming becomes easier, which can reduce the difficulty in manufacturing the glass element.

If Y ₂ O ₃ / B ₂ O ₃ is too low, it becomes difficult for gas to be released during the melting process, and the degree of foaming in the glass is deteriorated. Therefore, _{the lower limit of Y 2} O ₃ / B ₂ O ₃ is 0.15, preferably 0.2, and more preferably 0.3. However, if Y ₂ O ₃ / B ₂ O ₃ is too high, the chemical stability of the glass tends to decrease. Therefore, _{the upper limit of Y 2} O ₃ / B ₂ O ₃ is 2, preferably 1.8, more preferably 1.5, more preferably 1.3, and even more preferably 1.

Gd ₂ O ₃ and Y ₂ O ₃ can be replaced to some extent in terms of refractive index. Higher Y ₂ O ₃ / Gd ₂ O ₃ values are beneficial in reducing raw material costs. Furthermore, the present inventor has found that when Y ₂ O ₃ / Gd ₂ O ₃ is lower than 0.3 or higher than 3, the crystallization resistance performance of the glass is lowered. Therefore, Y ₂ O ₃ / Gd ₂ O ₃ is set to 0.3 to 3, preferably 0.5 to 2.5, more preferably higher than 1 but 2 or less.

The proportion of Y ₂ O _{3 in} the total rare earth oxide Y ₂ O ₃ / Ln ₂ O ₃ has a clear effect of adjusting the crystallization resistance. When _{the value of Y 2} O ₃ / Ln ₂ O ₃ is 0.08 to 0.45, the crystallization resistance performance is excellent. The value is more preferably 0.1 to 0.4, still more preferably 0.1 to 0.3.

In addition, Y ₂ O ₃ / (SiO ₂ + B ₂ O ₃ ) affects the chemical stability of the glass. When the value is 0.16 to 0.8, the chemical stability of the glass is excellent, the corrosion resistance is strong, and the useful life of the optical device can be effectively extended. The Y ₂ O ₃ / (SiO ₂ + B ₂ O ₃ ) value is more preferably 0.2 to 0.7, more preferably 0.3 to 0.6.

Yb ₂ O ₃ is a component having a high refractive index and low dispersion. When the content is higher than 5%, the stability and devitrification resistance of the glass are reduced. Therefore, _{the range of Yb 2} O ₃ content is defined as 0-5%. On the other hand, when Gd ₂ O ₃ and Y ₂ O ₃ are compared, _{it is preferable that Yb 2} O ₃ is not introduced because it is expensive and has almost no effect on the improvement of the meltability of the glass.

RO belonging to an alkaline earth metal oxide is one or more of CaO, MgO, SrO, and BaO, and is an optional component of the present invention. Approximate amounts of alkaline earth metal oxides have been added to the glass to improve the Young's modulus of the glass, reduce the high temperature viscosity of the glass, while balancing the glass composition and improving the meltability of the glass. You may. However, when the total content of RO is higher than 10%, the excess alkaline earth metal oxide deteriorates the crystallization resistance performance. Therefore, according to the present invention, the RO value is set to 0 to 10%, preferably 0 to 5%.

_{Rn 2} O belonging to the alkali metal oxide is _{one or more of Li 2} O, Na ₂ O, and K ₂ O, and is an optional component of the present invention. In the glass system provided by the present invention, an approximate amount of alkali metal oxide may be added to obtain the expected high temperature viscosity. On the other hand, if the alkali metal oxides approximate amount coexists with B ₂ O _3, and compactness of the B ₂ O ₃ network is improved, it is possible to obtain better light transmission. If the amount of alkali metal oxide is too small, the viscosity of the glass cannot be adjusted to an appropriate range, but if the amount of alkali metal oxide is too large, the crystallization resistance performance of the glass is significantly impaired. In the present invention, the Rn ₂ O value is 0 to 0. It is set to 10%, preferably 0 to 5%.

Further, 0 to 1%, preferably 0 to 0.5% of a clearing agent can be introduced into the glass provided by the present invention. The clarifying agent can be selected from _{Sb 2} O ₃ , or / and CeO _2, or / and SnO _2.

Includes _{P 2} O ₅ , Bi ₂ O ₃ , TeO ₂ , Ga ₂ O ₃ , GeO ₂ , Ta ₂ O ₅ , and Lu ₂ O _3, as appropriate, to the extent that the glass properties of the present invention are not impaired. Small amounts of other ingredients not listed above can be added. However, the constituents of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo, even when contained in the form of simple substances or compounds, are colored in glass and are visible in visible light. May absorb certain wavelengths. Since the property of the present invention for improving the visible light transmittance is weakened, it is preferable that the optical glass is not actually contained, especially in the optical glass that requires the wavelength transmittance in the visible region.

Pb, Th, Cd, Tl, Os, Be, and Se compounds have been controlled and used as harmful chemical substances in recent years, but they are used not only in the glass manufacturing process but also in processing procedures for environmental protection measures. It is also necessary for disposal after production. Therefore, when the impact on the environment is important, it is preferable that they are not actually contained except for the inevitable incorporation. As a result, 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 taking special environmental measures.

Characteristics of optical glass

Optical characteristics

The index of refraction (nd) is analyzed according to the method of GB / T7962.1-2010.

The variance coefficient (ie, Abbe number, vd) is analyzed according to the method of GB / T7962.1-2010.

[Thermal characteristics]

The coefficient of thermal expansion (α- _{30 ° C to 70 ° C} ) is analyzed in units of ^10-7 / K according to the method of GB / T7962.16-2010.

The conversion temperature (T _g ) is analyzed in units of ° C according to the method specified in GB / T7962.16-2010.

The method of analyzing the upper limit of the crystallization temperature is to analyze the crystallization characteristics of the glass using the process of a temperature gradient furnace, prepare the glass in a 180 × 10 × 10 mm sample, polish it laterally, and temperature. Put it in a furnace with a gradient (5 ° C / cm), heat it to 1,400 ° C, keep it warm for 4 hours, take it out, cool it naturally to room temperature, observe the crystallization of the glass with a microscope, and correspond to the crystal. Includes the step of obtaining an upper limit on the crystallization temperature of the glass when the maximum temperature of the glass to be used is discovered. The lower the upper limit of the crystallization temperature of the glass, the stronger the stability of the glass at high temperature and the better the performance of the manufacturing method.

[Chemical stability]

Water resistance ( _DW ) is analyzed according to the method of GB / T17129.

Acid resistance _{(D A)} are analyzed according to the method of GB / T17129.

[Degree of foam]

The degree of foam is analyzed according to the method of GB / T7962.8-2010.

After analysis, the glass provided by the present invention has the following properties. The refractive index (nd) is 1.84 to 1.87, preferably 1.85 to 1.86. The Abbe number (vd) is 38 to 41, preferably 38.5 to 40. The coefficient of thermal expansion (α _{-30 ° C to 70 ° C} ) is 75 × 10 ^-7 / K or less, preferably 70 × 10 ^-7 / K or less. The water resistance (D _W ) is grade 2 or higher, preferably grade 1. The acid resistance is preferably grade 3 or higher and grade 2 or higher. The upper limit of the crystallization temperature is 1,250 ° C. or lower, more preferably 1,200 ° C. or lower, and more preferably 1,180 ° C. or lower. The degree of foam is grade A or higher, preferably grade A ₀ or higher, and more preferably grade A ₀₀ . The conversion temperature (Tg) of the glass is 640 ° C. or lower, preferably 630 ° C. or lower, and more preferably less than 625 ° C.

Embodiment of optical glass

The following non-limiting embodiments are provided for the purpose of more clearly explaining and illustrating the technical solution of the present invention.

Weighed according to the corresponding content of all embodiments or comparative examples, the usual raw materials for optical glass (including oxides, hydroxides, carbonates, and nitrates) are mixed and the mixed raw materials are placed in a platinum crucible. Charged, melted at 1,200-1,500 ° C. for 2-6 hours, clarified, stirred, and homogenized to obtain homogeneous molten glass, after which the molten glass in the mold is cast. And annealing gives the optical glasses of Examples 1 to 48 of Tables 1 to 6 and Comparative Examples 1 to 5 of Table 7.

The optical glass according to the embodiment of the present invention is easy to perform precise press molding and has excellent devitrification resistance. The Ln ₂ O ₃ content is less than 55% and the cost is low. With good chemical stability, the water resistance ( _DW ) is grade 2 or higher, and the preferred technical solution is grade 1. Acid resistance is grade 3 or higher, and the preferred technical solution is grade 2 or higher. The degree of foam is grade A or higher, grade A ₀ or higher in the preferred technical solution, and grade A ₀₀ or higher in the more preferred technical solution. Thus, the degree of foam is excellent. The coefficient of thermal expansion (α- _{30 ° C to 70 ° C} ) is 75 × ^10-7 / K or less, and more preferably α- _{30 ° C} to 70 ° C is 70 × ^10-7 / K or less. The degree of expansion or contraction affected by temperature is small. On the other hand, optical glass has even better crystallization resistance.

Embodiment of Glass Preform The optical glass obtained in Embodiments 1 to 48 is cut into a predetermined size, and a mold release agent is uniformly applied to the surface. After that, the mold is heated and softened and press-molded in order to manufacture various lenses and prisms such as a concave meniscus lens, a convex meniscus lens, a biconvex lens, a biconcave lens, a plano-convex lens, and a plano-concave lens. Alternatively, the optical glass obtained in embodiments 1 to 48 is used to form a premolded product for precision press molding, which is then precision press molded into a lens and prism shape by precision press molding and processing to produce a preform. do.

Embodiment of Optical Element The preform obtained in the embodiment of the glass preform is annealed for fine adjustment while reducing the deformation inside the glass, and as a result, the optical characteristics such as the refractive index are set to the desired values. Become.

Next, each preform is ground and polished to form various lenses and prisms such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses. An antireflection film may be coated on the surface of the obtained optical element.

Embodiments of Optical Instruments An optical component or member is formed by an optical element obtained in an embodiment of an optical element, either through an optical design or via one or more optical elements. Optical components or components include imaging devices, sensors, microscopes, medical technology, digital projection, communication, optical communication technology / information transmission, optics / lighting in the automotive field, photolithography, excimer lasers, wafers, computer chips, integrated circuits, And can be used in electronic devices including such circuits and chips, especially camera optics and devices in the vehicle field.

Claims (19)

By weight percentage, 0 to 10% SiO ₂ , 5 to 25% B _{2 O 3} , 0 to 15% ZrO ₂ , 10 to 25% Zn O, _{and 2 to 30% TiO 2} + Nb _2. and O ₅ + WO _3, and it contains a _Ln 2 _{O 3} 30 to 55%, and the total of the _Ln 2 _{O 3} is _{La 2 O 3, Gd 2 O} 3, Y 2 O 3, and _Yb 2 _{O 3} a _{content, B 2 O 3 / Ln 2} O 3 is 0.3 to _0.8, optical glass _{Y 2 O 3 / B 2 O} 3 is characterized in that it is a 0.15 to 2. Further containing 0 to 10% RO, 0 to 10% Rn ₂ O, and 0 to 1% clarifying agent, wherein the RO is one or more of MgO, CaO, SrO, or BaO. Claim 1 characterized in that Rn ₂ O is _{one or more of Li 2} O, Na ₂ O, and K ₂ O, and the clarifying agent is one or more of Sb ₂ O ₃ , SnO _{2, and} CeO _2. The optical glass described in. By weight percentage, 0 to 10% SiO _{2 ,} 5 to 25% B _{2 O 3} , 0 to 15% ZrO ₂ , 10 to 25% Zn O, _{and 2 to 30% TiO 2} + Nb _2. It _{contains O 5} + WO ₃ , 30 to 55% Ln ₂ O ₃ , 0 to 10% RO, 0 to 10% Rn ₂ O, and 0 to 1% clarifying agent. Ln ₂ O ₃ is _{the total content of La 2} O ₃ , Gd ₂ O ₃ , Y ₂ O ₃ , and Yb ₂ O ₃ , and the RO is one or more of MgO, CaO, SrO, or BaO. The Rn ₂ O is _{one or more of Li 2} O, Na ₂ O, and K ₂ O, and the clarifying agent is one or more of Sb ₂ O ₃ , SnO _{2, and} CeO ₂ , and B ₂ O ₃ / Ln. ₂ O ₃ is 0.3 to _0.8, optical glass Y ₂ O _{3 /} B 2 _{O 3} is characterized in that it is a 0.15 to 2. The optical glass according to any one of claims 1 to 3, wherein the content of all the components satisfies one or more of the following four conditions.
1) SiO ₂ / (SiO ₂ + B ₂ O ₃ ) is 0 to 0.25.
2) Y ₂ O ₃ / Ln ₂ O ₃ is 0.08 to 0.45.
3) Y ₂ O ₃ / Gd ₂ O ₃ is 0.3 to 3,
4) Y ₂ O ₃ / (SiO ₂ + B ₂ O ₃ ) is 0.16 to 0.8. SiO ₂ is 1 to 8%, and / or B ₂ O ₃ is 10 to 23%, and / or ZrO ₂ is 1 to 10%, and / or ZnO is 10 to 20%, and / or TIO ₂ + Nb ₂ O. ₅ + WO ₃ is 4 to 22%, and / or Ln ₂ O ₃ is 35 to 52%, and / or RO is 0 to 5%, and / or R ₂ O is 0 to 5%, and / or a clarifying agent. The optical glass according to any one of claims 1 to 3, wherein the amount is 0 to 0.5%. The optical glass according to any one of claims 1 to 3, wherein the content of all the components satisfies one or more of the following six conditions.
1) SiO ₂ / (SiO ₂ + B ₂ O ₃ ) is 0.05 to 0.23.
2) Y ₂ O ₃ / Ln ₂ O ₃ is 0.1 to 0.4,
3) Y ₂ O ₃ / Gd ₂ O ₃ is 0.5 to 2.5,
4) Y ₂ O ₃ / (SiO ₂ + B ₂ O ₃ ) is 0.2 to 0.7.
5) B ₂ O ₃ / Ln ₂ O ₃ is 0.3 to 0.6,
6) Y ₂ O ₃ / B ₂ O ₃ is 0.2 to 1.5. SiO ₂ is 1 to 4%, and / or B ₂ O ₃ is 15 to 20%, and / or ZrO ₂ is 2 to 6%, and / or ZnO is 13 to 17%, and / or TIO ₂ + Nb ₂ O. The optical glass according to any one of claims 1 to 3 _{, wherein 5} + WO ₃ is 10 to 18% and / or Ln ₂ O _{3 is 40 to 50%.} The optical glass according to any one of claims 1 to 3, wherein the content of all the components satisfies one or more of the following six conditions.
1) SiO ₂ / (SiO ₂ + B ₂ O ₃ ) is 0.08 to 0.2.
2) Y ₂ O ₃ / Ln ₂ O ₃ is 0.1 to 0.3,
3) Y ₂ O ₃ / Gd ₂ O ₃ is greater than 1 and less than or equal to 2.
4) Y ₂ O ₃ / (SiO ₂ + B ₂ O ₃ ) is 0.3 to 0.6.
5) B ₂ O ₃ / Ln ₂ O ₃ is 0.3 to 0.5,
6) Y ₂ O ₃ / B ₂ O ₃ is 0.3 to 1. Nb ₂ O ₅ is 1 to 15%, and / or WO ₃ is 1 to 15%, and / or TiO ₂ is 0 to 10%, and / or La ₂ O ₃ is 20 to 45%, and / or Gd _2. O ₃ 0 to 15% and / or _Y 2 _{O 3} from 1 to 15% and / or _Yb 2 _{O 3} is any one of the preceding claims, characterized in that the 0 to 5% The optical glass described in. Nb ₂ O ₅ is 2-10%, and / or WO ₃ is 2-12%, and / or TiO ₂ is 0-5%, and / or La ₂ O ₃ is 25-40%, and The optical glass according to any one of claims 1 to 3, wherein / or Gd ₂ O ₃ is 1 to 10% and / or Y ₂ O _{3 is 3 to 15%.} Nb ₂ O ₅ is 4-8%, and / or WO ₃ is 6-10%, and / or La ₂ O ₃ is 30-35%, and / or Gd ₂ O ₃ is 3-7%, and / or. The optical glass according to any one of claims 1 to 3, wherein Y ₂ O ₃ is 6 to 10% and / or TiO _{2 is not contained.} The refractive index (nd) of the optical glass is 1.84 to 1.87, preferably 1.85 to 1.86, and the Abbe number (vd) is 38.0 to 41.0, preferably 38.5 to. The optical glass according to any one of claims 1 to 3, which is 40.0. _{The water resistance (D W} ) of the powder method of the optical glass is grade 2 or higher, preferably grade 1, and the acid resistance (D _W ) of the powder method is grade 3 or higher, preferably grade 2. The optical glass according to any one of claims 1 to 3. Claims 1 to 3 characterized in that the coefficient of thermal expansion (α- _{30 ° C to 70 ° C} ) of the optical glass is 75 × 10 ^-7 / K or less, preferably 70 × 10 ^{-7 / K or less.} The optical glass according to any one of the above items. The optical glass according to any one of claims 1 to 3, wherein the degree of bubbles of the optical glass is grade A or higher, preferably grade _{A0 or higher.} The conversion temperature (Tg) of the optical glass is 640 ° C. or lower, preferably 630 ° C. or lower, more preferably 625 ° C. or lower, and the upper limit of the crystallization temperature of the optical glass is 1,250 ° C. or lower, preferably 1,200 ° C. The optical glass according to any one of claims 1 to 3, wherein the temperature is ℃ or less, more preferably 1,180 ℃ or less. A glass preform made from the optical glass according to any one of claims 1 to 16. An optical element manufactured from the optical glass according to any one of claims 1 to 16 or the glass preform according to claim 17. An optical device manufactured from the optical element according to claim 18.