Optical glass, optical element, and optical apparatus

Abstract

To provide an optical glass having a refractive index of 1.46 to 1.52, an Abbe number of 81 to 89, excellent large-diameter moldability, and excellent thermal stability usable for large-diameter press working.SOLUTION: The cation components comprise 7-27% of P5 +, 10-45% of Al3 +, 5-25% of Ba2 +, 5-25% of Sr2 + and 5-30% of Ca2 +, and the anion components comprise 50-90% of F - and 10-50% of O2 -. Through reasonable component design, the optical glass of the present invention has excellent large-diameter forming performance and excellent thermal stability for large-diameter pressing while ensuring excellent optical properties.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an optical glass, and more particularly to an optical glass having a refractive index of 1.46 to 1.52 and an Abbe number of 81 to 89. [Background technology]

[0002] Fluorophosphate optical glass is a relatively widely used new type of glass material, with the characteristics of low dispersion and low refractive index, which can eliminate the special dispersion of secondary spectrum in optical systems, increase the resolution, and significantly improve the imaging quality of optical systems.In the prior art, fluorophosphate optical glass with a refractive index of 1.46-1.52 and an Abbe number in the range of 81-89 is mainly used in small diameter optical systems, so scientific researchers often pay attention to the molding and precision stamping performance of small diameter fluorophosphate glass.

[0003] In recent years, with the rapid development of large-aperture precision optical devices, there has been an increasing demand for large-aperture, high-optical uniformity fluorophosphate glass. Conventional fluorophosphate glass with a refractive index of 1.46-1.52 and an Abbe number in the range of 81-89 is prone to stripes forming inside the glass during the molding process for large-aperture (thickness > 20 mm), resulting in poor imaging quality for the manufactured optical elements. Furthermore, this type of glass has poor thermal stability, making it difficult to achieve large-aperture precision press processing. These issues limit its use in large-aperture precision optical devices. Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, the technical problem to be solved by the present invention is to provide an optical glass having a refractive index of 1.46 to 1.52, an Abbe number of 81 to 89, excellent large-diameter formability, and excellent thermal stability that allows it to be used in large-diameter press processing. [Means for solving the problem]

[0005] The technical solutions adopted by the present invention to solve the technical problems are as follows.

[0006] (1) The amount of components is expressed in mole percent. The cation component is P. 5+ : 7~27%, Al 3+ : 10~45%, Ba 2+ : 5-25%, Sr 2+ : 5 to 25%, and Ca 2+ : Contains 5-30% and the anion component is F - : 50-90% and O 2- : Optical glass containing 10-50%.

[0007] (2) The component amounts are expressed in mole percent, and the cation components are further divided into Mg 2+ :0~15%, Y 3+ : 0-10%, La 3+ : 0-10%, Gd 3+ :0~10%, R + : 0 to 10%, and Sb 3+ : Contains one or more components selected from the group consisting of 0 to 1% of the R + Li + , Na + , and K + The anion component is one or more selected from the group consisting of: - The optical glass according to (1), containing 0 to 1% of:

[0008] (3) The amount of components is expressed in mole percent. The cation component is P. 5+ : 7~27%, Al 3+ : 10~45%, Ba 2+ : 5-25%, Sr 2+ : 5-25%, Ca 2+ : 5-30%, Mg 2+ :0~15%, Y 3+ : 0-10%, La 3+ : 0-10%, Gd 3+ :0~10%, R + : 0 to 10%, and Sb 3+ : 0 to 1%, and the R + Li + , Na + , and K +The anion component is one or more selected from the group consisting of F - : 50-90%, O 2- : 10 to 50%, and Cl - : Optical glass consisting of 0 to 1%.

[0009] (4) An optical glass according to any one of (1) to (3), wherein the component amounts are expressed in mole percent and the glass satisfies one or more of the following six conditions: 1) (Ba 2+ +Sr 2+ +Ca 2+ ) / Ba 2+ is 2.0~4.6; 2) (45%-Al 3+ ) / (15%-Mg 2+ ) is 0.3~5.0; 3) (Al 3+ +Mg 2+ ) / Ba 2+ is 1.5~3.5; 4) (45%-Al 3+ ) / (Gd 3+ +Y 3+ +La 3+ +Li + ) is 2.0~80.0; 5) Mg 2+ / Al 3+ is 0~0.5; 6) (Al 3+ -Mg 2+ -Li + ) / P 5+ is 0.5 to 2.5.

[0010] (5) An optical glass according to any one of (1) to (3), wherein the amounts of the components are expressed in mole percent and the glass satisfies one or more of the following six conditions: 1) (Ba 2+ +Sr 2+ +Ca 2+ ) / Ba 2+ is 2.5-4.1; 2) (45%-Al 3+ ) / (15%-Mg 2+ ) is 0.5~3.0; 3) (Al 3+ +Mg 2+ ) / Ba 2+is 2.0~3.0; 4) (45%-Al 3+ ) / (Gd 3+ +Y 3+ +La 3+ +Li + ) is 6.0~50.0; 5) Mg 2+ / Al 3+ is 0~0.3; 6) (Al 3+ -Mg 2+ -Li + ) / P 5+ is 1.0~2.3.

[0011] (6) An optical glass according to any one of (1) to (3), wherein the component amounts are expressed in mole percent and the glass satisfies one or more of the following six conditions: 1) (Ba 2+ +Sr 2+ +Ca 2+ ) / Ba 2+ is 3.0-3.9; 2) (45%-Al 3+ ) / (15%-Mg 2+ ) is 0.6~2.0; 3) (Al 3+ +Mg 2+ ) / Ba 2+ is 2.3-2.7; 4) (45%-Al 3+ ) / (Gd 3+ +Y 3+ +La 3+ +Li + ) is 8.0~35.0; 5) Mg 2+ / Al 3+ is 0~0.1; 6) (Al 3+ -Mg 2+ -Li + ) / P 5+ is 1.3~2.1.

[0012] (7) The component amount is expressed in mole percent, and P 5+ : 11~24%, Al 3+ : 18~40%, Ba 2+ : 9~21%, Sr 2+ : 8-21%, Ca 2+: 10-25%, Mg 2+ :0~10%, Y 3+ : 0~5%, La 3+ : 0-5%, Gd 3+ :0~5%, R + : 0 to 6%, and Sb 3+ : Contains one or more components selected from the group consisting of 0 to 0.5%, and + Li + , Na + , and K + The optical glass according to any one of (1) to (6), which is one or more selected from the group consisting of:

[0013] (8) The component amount is expressed in mole percent, and P 5+ : 15-20%, Al 3+ :24~35%, Ba 2+ : 12-19%, Sr 2+ : 11-17%, Ca 2+ : 15-20%, Mg 2+ :0~5%, Y 3+ :0~3%, La 3+ :0-2%, Gd 3+ :0~3%, R + : 0 to 3%, and Sb 3+ : Contains one or more components selected from the group consisting of 0 to 0.3%, and + Li + , Na + , and K + The optical glass according to any one of (1) to (6), which is one or more selected from the group consisting of:

[0014] (9) The component amount is expressed in mole percent, F - :60-80%, O 2- : 20-40%, and Cl - The optical glass according to any one of (1) to (8), which contains 0 to 0.5% of one or more components selected from the group consisting of:

[0015] (10) The component amount is expressed in mole percent, and F - :67-75%, O 2- : 25-33%, and Cl -The optical glass according to any one of (1) to (8), which contains 0 to 0.3% of one or more components selected from the group consisting of:

[0016] (11) An optical glass according to any one of (1) to (10), which satisfies one or more of the following ten conditions: 1) Refractive index n d is 1.46~1.52, 2) Abbe number ν d 81 to 89, 3) λ 80 is 340 nm or less, 4) λ5 is 265 nm or less, 5) Density ρ is 3.90 g / cm 3 below, 6)Transition temperature T g is below 500℃, 7) Acid resistance RA is 3 or higher, 8) Moisture resistance stability RC is Class 2 or higher, 9) Stripes are C grade or higher, 10) Crystallization resistance is class D or higher.

[0017] (12) An optical glass according to any one of (1) to (10), which satisfies one or more of the following ten conditions: 1) Refractive index n d is 1.48~1.50, 2) Abbe number ν d 84~87, 3) λ 80 is 320 nm or less, 4) λ5 is 245 nm or less, 5) Density ρ is 3.74g / cm 3 below, 6)Transition temperature T g is 480℃ or less, 7) Acid resistance RA is Class 2 or higher, 8) Moisture resistance stability RC is Class 1, 9) Stripes are grade A, 10) Crystallization resistance is Class A.

[0018] (13) A glass preform comprising the optical glass according to any one of (1) to (12). (14) An optical element comprising the optical glass according to any one of (1) to (12) or the glass preform according to (13). (15) An optical instrument comprising the optical glass according to any one of (1) to (12) and / or the optical element according to (14). [Effects of the Invention]

[0019] The beneficial effects of the present invention are as follows: By rationally designing the components, the optical glass of the present invention is ensured to have excellent optical performance, and at the same time, it has excellent large-diameter molding performance and excellent thermal stability that allows it to be used in large-diameter press processing. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the optical glass according to the present invention will be described in detail, but the present invention is not limited to the embodiments described below, and can be practiced by making appropriate modifications within the scope of the object of the present invention. Furthermore, although some omissions may be made, the gist of the present invention is not limited by repetition of the description, and hereinafter the optical glass of the present invention may also be referred to simply as glass.

[0021] [Optical glass] The components constituting the optical glass of the present invention are described below. In this specification, unless otherwise specified, the content of a cation component is expressed as the molar percentage (mol%) of the cation relative to the total cation components, the content of an anion component is expressed as the molar percentage (mol%) of the anion relative to the total anion components, and the content ratio of cation components is the ratio of the molar percentage contents of each cation component.

[0022] Specifically, the numerical ranges set forth herein include upper and lower limits, and the terms "greater than or equal to" and "less than or equal to" include the endpoints, and all integers and fractions subsumed within the range, but are not limited to the specific values ​​set forth when the range is limited. References herein to "and / or" are inclusive, e.g., "A and / or B" means A only, B only, or both A and B.

[0023] The ionic valence of each component explained below is a representative value used for convenience, and is not distinguished from other ionic valences. The ionic valence of each component of optical glass may be other than the representative value. For example, P is usually present in glass in a +5 ionic valence state, so in this specification it is referred to as "P 5+ " is a representative value, but other ionic valence states may exist, which are also within the scope of the present invention.

[0024] <Cationic components> P 5+ is a component forming the optical glass of the present invention, and can suppress devitrification of the glass and an increase in density. If its content is less than 7%, the devitrification resistance of the glass decreases and the density increases, while if its content exceeds 27%, the Abbe number of the glass decreases and the cost increases. Therefore, in the present invention, P 5+ The content is 7 to 27%, preferably 11 to 24%, and more preferably 15 to 20%.

[0025] Al 3+ Al can increase the stability of glass, effectively improving the processability and chemical stability of glass, while also increasing the viscosity during the glass forming process. 3+ If the Al content is less than 10%, it is not possible to form a stable glass skeleton and obtain the above-mentioned effects. 3+ If the Al content exceeds 45%, the glass transition temperature and liquidus temperature rise, making melting difficult, and the temperature during molding rises, causing intense glass volatilization and worsening stripes in the glass, which is unfavorable for large-diameter molding. On the other hand, an excessively high transition temperature makes press working difficult. Therefore, in the present invention, the Al content is 3+The content is 10 to 45%, preferably 18 to 40%, and more preferably 24 to 35%.

[0026] Ba 2+ can increase the refractive index, thermal stability and weather resistance of glass, but Ba 2+ If the amount of Ba is too large, the density of the glass increases, the abrasion resistance increases, the viscosity decreases, and stripes become worse during molding, making it difficult to obtain a large-diameter, high-quality optical glass. 2+ The content is 5 to 25%, preferably 9 to 21%, and more preferably 12 to 19%.

[0027] Sr 2+ Sr can reduce the thermal expansion coefficient of the glass, effectively adjust the refractive index and density of the glass, and increase the viscosity of the glass to improve stripes during molding. However, if its content is too high, the devitrification resistance and chemical stability of the glass will be reduced. Therefore, in the present invention, Sr 2+ The content is 5 to 25%, preferably 8 to 21%, and more preferably 11 to 17%.

[0028] Ca 2+ Ca can increase the viscosity of the glass, improve the forming stripe, increase the chemical stability of the glass, and improve the polishing performance of the glass. However, if the content is too high, the refractive index of the glass will not reach the design requirement, and devitrification resistance may be deteriorated. Therefore, in the present invention, Ca is used. 2+ The content is 5 to 30%, preferably 10 to 25%, and more preferably 15 to 20%.

[0029] The inventors have conducted extensive research and have shown that in some embodiments, 2+ +Sr 2+ +Ca 2+ ) / Ba 2+ By controlling the ratio to 2.0 or more, the viscosity of the glass liquid in the molding stage can be well controlled, the stability of the glass can be improved, and a large-diameter optical glass with a good stripe state can be obtained. 2+ +Sr 2+ +Ca 2+ ) / Ba 2+It has been found that if (Ba) exceeds 4.6, the devitrification resistance of the glass drops sharply, making it difficult to form. 2+ +Sr 2+ +Ca 2+ ) / Ba 2+ is preferably 2.0 to 4.6, more preferably 2.5 to 4.1, and even more preferably 3.0 to 3.9.

[0030] Mg 2+ Although Mg can improve the abrasion resistance of glass, increase the viscosity of glass, and improve the stripe forming, if its content exceeds 15%, the thermal stability of glass will be significantly reduced. Therefore, in the present invention, Mg 2+ The content is 0 to 15%, preferably 0 to 10%, and more preferably 0 to 5%.

[0031] In some embodiments, Mg 2+ and Al content 3+ The ratio of Mg content to 2+ / Al 3+ By controlling the ratio to 0.5 or less, the crystallization resistance of the glass can be improved and excellent productivity of the glass can be achieved. 2+ / Al 3+ is preferably 0 to 0.5, more preferably 0 to 0.3, and even more preferably 0 to 0.1.

[0032] The inventors have conducted extensive research and have shown that, in some embodiments, Al 3 Maximum content of 45% and Al 3 The difference between the actual content and Al is 45% 3+ and Mg 2+ Maximum content of 15% and Mg 2+ The actual content differs by 15% - Mg 2+ Ratio to (45%-Al 3+ ) / (15%-Mg 2+ It was found that by controlling the content of 45%-Al, the thermal stability (crystallization resistance) during reheating of the glass can be effectively controlled. 3+ ) / (15%-Mg 2+) is 5.0 or less, the thermal stability of the glass can be significantly optimized and stable pressing of large diameters can be achieved. 3+ ) / (15%-Mg 2+ If the (45%-Al) is less than 0.3, the crystallization resistance of the glass deteriorates, the liquidus temperature rises, and the glass becomes difficult to produce. 3+ ) / (15%-Mg 2+ ) is preferably 0.3 to 5.0, more preferably 0.4 to 4.0, even more preferably 0.5 to 3.0, and even more preferably 0.6 to 2.0.

[0033] Al 3+ , Mg 2+ Ba can form a network in fluorophosphate glass and increase the viscosity of the glass liquid, but it can also increase the glass liquidus temperature. 2+ Al can improve the devitrification resistance of the glass liquid while adjusting the viscosity of the glass. 3+ +Mg 2+ and Ba 2+ Ratio to (Al 3+ +Mg 2+ ) / Ba 2+ When the value is 3.5 or less, a fluorophosphate glass having an appropriate viscosity and excellent resistance to devitrification can be obtained. 3+ +Mg 2+ ) / Ba 2+ If the value is less than 1.5, the viscosity of the glass liquid is too low, resulting in a narrow forming zone and poor stripes, which is unfavorable for large diameter forming. 3+ +Mg 2+ ) / Ba 2+ is preferably 1.5 to 3.5, more preferably 2.0 to 3.0, and even more preferably 2.3 to 2.7.

[0034] Y 3+ Y can increase the refractive index of the glass and reduce the thermal expansion coefficient, but if its content exceeds 10%, the liquidus temperature of the glass rises, the devitrification resistance decreases, the viscosity changes with temperature change become rapid, and it becomes difficult to control large-diameter molding. 3+The content is 0 to 10%, preferably 0 to 5%, and more preferably 0 to 3%.

[0035] La 3+ can increase the refractive index of glass and improve its acid resistance, but La 3+ If the content of La is too high, the thermal stability and devitrification resistance of the glass decrease, and the glass becomes more susceptible to devitrification during production. 3+ The content is 0 to 10%, preferably 0 to 5%, and more preferably 0 to 2%.

[0036] Gd 3+ improves the stability of the glass, appropriately increases the refractive index while maintaining low dispersion, appropriately increases the mechanical strength, and reduces the thermal expansion coefficient. However, if its content exceeds 10%, the devitrification resistance of the glass decreases. Therefore, Gd 3+ The content is 0 to 10%, preferably 0 to 5%, and more preferably 0 to 3%.

[0037] R + (R + Li + , Na + , and K + (one or more selected from the group consisting of) can effectively lower the glass transition temperature, + If the content of R exceeds 10%, the liquidus temperature of the glass rises and the viscosity decreases, making molding difficult. + The content of R is 0 to 10%, preferably 0 to 6%, and more preferably 0 to 3%. + Does not include.

[0038] Through extensive experimental work, the inventors have shown that, in some embodiments, Al 3+ Maximum content of 45% and Al 3+ The difference between the actual content and Al is 45% 3+ and Gd, a component that easily crystallizes 3+ , Y 3+ , La 3+ , Li + The total content of Gd 3+ +Y 3++La 3+ +Li + Ratio to (45%-Al 3+ ) / (Gd 3+ +Y 3+ +La 3+ +Li + When (45%-Al) is more than 2.0, the crystallization tendency is low and it is easy to obtain a glass with a good stripe state. 3+ ) / (Gd 3+ +Y 3+ +La 3+ +Li + ) exceeds 80.0, the coloring degree of the glass becomes high, the stripe state becomes poor, and forming becomes difficult. 3+ ) / (Gd 3+ +Y 3+ +La 3+ +Li + ) is preferably 2.0 to 80.0, more preferably 6.0 to 50.0, and even more preferably 8.0 to 35.0.

[0039] In some embodiments, Al 3+ and Mg content 2+ , Li + The difference between the content of Al 3+ -Mg 2+ -Li + and P 5+ The ratio of the content of Al 3+ -Mg 2+ -Li + ) / P 5+ By controlling the (Al) in the range of 0.5 to 2.5, the crystallization resistance of the glass can be improved and at the same time, the expected optical performance can be easily achieved. 3+ -Mg 2+ -Li + ) / P 5+ is preferably 0.5 to 2.5, more preferably 1.0 to 2.3, and even more preferably 1.3 to 2.1.

[0040] The optical glass of the present invention contains 1% or less of Sb as a fining agent. 3+ The addition of Sb can enhance the fining effect of glass. 3+The content is preferably 0 to 0.5%, more preferably 0 to 0.3%.

[0041] Ta may be added as needed without impairing the excellent properties of the glass of the present invention. 5+ , W 6+ , Ge 4+ , Bi 3+ , Te 4+ Other components such as the above may be added to the optical glass of the present invention.

[0042] <Anion component> F - F plays a major role in lowering the refractive index, refractive index temperature coefficient and transition temperature of glass, and is an important component in increasing the Abbe number and anomalous dispersion. - If the content is too high, the stability of the glass will decrease, the coefficient of thermal expansion and the degree of abrasion will increase, especially during melting. - The evaporation of F not only pollutes the environment, but can also cause the optical constants of the glass to exceed their designed range. - If the content is less than 50%, it is difficult to obtain the designed Abbe number and anomalous dispersion. - If the content of F exceeds 90%, the Abbe number of the glass becomes excessively large, and volatilization during melting and precision press processing increases rapidly. - The content is 50 to 90%, preferably 60 to 80%, and more preferably 67 to 75%.

[0043] The optical glass of the present invention 2- , especially 10% or more O 2- When O is added, excellent optical performance and low wear rate can be achieved. 2- If the content of O exceeds 50%, the liquidus temperature of the glass rises rapidly. 2- The content is 10 to 50%, preferably 20 to 40%, and more preferably 25 to 33%.

[0044] The optical glass of the present invention contains 1% or less of Cl as a fining agent. - By adding Cl, the fining effect of the glass can be improved. -The content is preferably 0 to 0.5%, more preferably 0 to 0.3%.

[0045] <Ingredients that should not be included> Components other than those mentioned above can be added as needed without impairing the excellent properties of the glass of the present invention. However, transition metal components such as Ce, V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo, even when contained alone or in combination, tend to color the glass and cause absorption at specific wavelengths in the visible light region, thereby reducing the visible light transmittance improving effect of the present invention. Therefore, for optical glasses that require transmittance at wavelengths in the visible light region in particular, it is preferable that the above components are not actually contained.

[0046] In recent years, there has been a trend toward restricting the use of Pb, Th, Cd, Tl, Os, Be, and Se cations as harmful chemicals, necessitating environmental protection efforts not only in the glass manufacturing process but also in the processing and disposal of finished products. Therefore, when environmental impact is a major concern, it is preferable to avoid these cations except for unavoidable contamination. This ensures that the optical glass does not contain substances that actually pollute the environment. Therefore, the optical glass of the present invention can be manufactured, processed, and disposed of without requiring special environmental measures.

[0047] The terms "free" and "0%" used herein mean that the corresponding component was not intentionally added as a raw material for the glass of the present invention. However, impurities or components that are not intentionally added as raw materials and / or equipment for producing optical glass may exist in small or trace amounts in the final glass, and these are also within the scope of the present invention.

[0048] The properties of the optical glass of the present invention will be described below. <Refractive index and Abbe number> The refractive index of optical glass (n d ) and Abbe number (ν d ) has been tested in accordance with the method specified in "GB / T 7962.1-2010". In some embodiments, the refractive index (nd ) is 1.46 to 1.52, preferably 1.47 to 1.51, and more preferably 1.48 to 1.50. In some embodiments, the Abbe number (ν d ) is 81 to 89, preferably 83 to 88, and more preferably 84 to 87.

[0049] <Coloring degree> The short-wave transmission spectrum characteristics of the optical glass of the present invention are determined by the coloring degree (λ 80 / λ5). 80 λ is the wavelength corresponding to the glass transmittance reaching 80%, and λ5 is the wavelength corresponding to the glass transmittance reaching 5%. 80 indicates the wavelength at which the transmittance is 80% when the spectral transmittance is measured in the wavelength range from 280 nm to 700 nm using a glass with a thickness of 10±0.1 mm and two optically polished flat surfaces that are parallel to each other. The spectral transmittance or transmittance is the wavelength at which the transmittance is 80% when the intensity I is measured perpendicular to the surface of the glass. in The light with intensity I is incident on the glass and passes through it to the other plane. out When emitting light of I out / I in and includes the transmittance of the surface reflection loss on the surface of the glass. 80 The smaller the value, the less coloring there is in the glass itself. λ5 can be understood in the same way.

[0050] In some embodiments, the λ 80 is 340 nm or less, preferably 335 nm or less, more preferably 330 nm or less, even more preferably 325 nm or less, and even more preferably 320 nm or less. In some embodiments, the λ5 of the optical glass of the present invention is 265 nm or less, preferably 260 nm or less, more preferably 255 nm or less, even more preferably 250 nm or less, and even more preferably 245 nm or less.

[0051] <density> The density (ρ) of optical glass is measured in accordance with the method specified in GB / T 7962.20-2010 and is expressed as the mass per volume at 20°C in g / cm. 3 It is expressed as: In some embodiments, the density (ρ) of the optical glass of the present invention is 3.90 g / cm 3 or less, preferably 3.82 g / cm 3 or less, more preferably 3.78 g / cm 3 or less, more preferably 3.74 g / cm 3 The following is the result.

[0052] <Transition temperature> Optical glass transition temperature (T g ) is measured according to the method specified in "GB / T 7962.16-2010". In some embodiments, the transition temperature (T g ) is 500°C or less, preferably 490°C or less, and more preferably 480°C or less.

[0053] <Acid resistance stability> The acid resistance (RA) (surface method) of optical glass is tested according to the method specified in "GB / T 7962.14-2010". In some embodiments, the acid stability (RA) of the optical glass of the present invention is Class 3 or higher, preferably Class 2 or higher.

[0054] <Moisture resistance stability> The humidity stability (RC) (surface method) of optical glass is tested according to the method specified in "GB / T 7962.15-2010". In some embodiments, the optical glass of the present invention has a humidity stability (RC) of Class 2 or higher, preferably Class 1.

[0055] <Stripe> The glass is formed into a width of 200 mm and a thickness of 30 mm, which is then cut into a single piece every 360 mm to obtain a glass blank. The blank size is width x thickness x length = 200 mm x 30 mm x 360 mm. The glass blank is then processed into a specimen measuring width x thickness x length = 200 mm x 30 mm x 80 mm, and both end faces in the longitudinal direction are polished to obtain a specimen for the stripe test. Glass stripes are checked by comparing a standard sample with a stripe meter consisting of a point light source and a lens from the direction where the stripes are most visible. The grades are divided into four levels. See Table 1 below for details.

[0056] [Table 1]

[0057] In some embodiments, when the glass molding thickness is greater than 20 mm, the stripe of the optical glass of the present invention is Class C or higher, preferably Class B or higher, more preferably Class A, and has excellent large-diameter molding performance.

[0058] <Crystallization resistance> The crystallization resistance of the optical glass of the present invention was tested as follows. A glass sample of 10 mm x 20 mm x 20 mm was placed in a semicircular ceramic container with a radius of 15 mm and a depth of 15 mm. The glass sample and the ceramic container were then placed in a T g The first heating is done in a test furnace at + (140-160°C), and the heating time is 15 minutes. Then it is taken out and cooled to 200°C in a tunnel annealing furnace, and then the temperature is kept at T gThe second heating is carried out in a test furnace set to +(140-160°C), for 15 minutes. It is then removed and placed in a tunnel annealing furnace, where the temperature is again lowered to 200°C. After the second heating, the glass sample and ceramic container are placed in a tunnel annealing furnace, where the temperature is lowered to 200°C. The glass sample is then removed and allowed to cool naturally to room temperature in an atmospheric environment. After polishing the glass sample, the softening and devitrification of the entire glass are observed with the naked eye, and the interior of the glass is observed under a microscope to check for the presence of crystal particles. The crystallization resistance of the glass is judged based on Table 2 below. Grade A is the best, and Grade E is the worst.

[0059] [Table 2]

[0060] In some embodiments, the optical glass of the present invention has a crystallization resistance of Class D or higher, preferably Class C or higher, more preferably Class B, and even more preferably Class A, and has excellent thermal stability that allows it to be used in large-diameter press working.

[0061] [Optical glass manufacturing method] The method for producing the optical glass of the present invention is as follows. The optical glass of the present invention is manufactured using conventional raw materials, such as carbonates, nitrates, sulfates, phosphates, oxides, fluorides, and metaphosphates, and conventional processes. Furnace materials prepared by blending ingredients in a conventional manner are placed in a melting furnace at 900 to 1000°C and melted. The resulting mixture is then clarified and homogenized, and poured at a temperature of 800°C or less for molding or injection molding to obtain the optical glass of the present invention. Those skilled in the art will be able to select the raw materials, manufacturing methods, and process parameters as appropriate for specific needs.

[0062] [Glass preforms and optical elements] A glass preform can be produced from the produced optical glass using press molding means such as polishing, hot press molding, precision press molding, etc. That is, an optical preform can be produced from the optical glass by mechanical processing such as grinding or polishing, or a blank for press molding can be produced from the optical glass, and this blank can be hot press molded and then polished to produce an optical preform, or the polished blank can be precision press molded to produce an optical preform. Note that the means for producing the optical preform are not limited to the above means.

[0063] As described above, the optical glass of the present invention is useful for various optical elements and optical designs, and it is particularly preferable to form a blank from the optical glass of the present invention and use this blank to carry out hot press molding, precision press molding, or the like to produce optical elements such as lenses and prisms.

[0064] The optical preform and optical element of the present invention are both formed from the optical glass of the present invention. The glass preform of the present invention has excellent properties as an optical glass, and the optical element of the present invention has excellent properties as an optical glass. Examples of lenses include various lenses with spherical or aspherical lens surfaces, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses.

[0065] [Optical equipment] Optical devices such as photographic devices, imaging devices, display devices and monitoring devices can be manufactured using optical elements formed from the optical glass of the present invention. [Example]

[0066] <Optical Glass Examples> To further clearly illustrate the technical solutions of the present invention, the following non-limiting examples are provided. In the present examples, the optical glass manufacturing method described above was used to obtain optical glasses having the compositions shown in Tables 3 to 5. The properties of each glass were measured using the test methods described in the present invention, and the results are shown in Tables 3 to 5.

[0067] [Table 3]

[0068] [Table 4]

[0069] [Table 5]

[0070] <Example of glass preform> Using the glasses obtained in Examples 1 to 22 of the optical glass, various lenses, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses, as well as preforms for prisms, were manufactured by polishing or by press molding, such as reheat press molding and precision press molding. The products obtained by press molding were free of crystal particles, and the press processing efficiency and product yield were greatly improved.

[0071] <Optical element examples> The preforms obtained in the above glass preform examples were annealed to fine-tune the refractive index while reducing the stress inside the glass so that the optical properties such as the refractive index reached the desired values. Next, each preform was ground and polished to produce various lenses and prisms, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses.Anti-reflection coatings can also be applied to the surfaces of the obtained optical elements.

[0072] The optical glasses obtained in Examples 1 to 22 were cut to the specified size, and the blanks were subjected to optical cold processing such as grinding and polishing to obtain large-diameter, high-quality optical elements. An anti-reflection coating can also be applied to the surface of the obtained optical elements.

[0073] <Optical equipment example> The optical elements manufactured according to the above optical element embodiments can be used in imaging devices, sensors, microscopes, medical technology, digital projection, communications, optical communication technology / information transmission, optics / illumination in the automotive field, photolithography technology, excimer lasers, wafers, computer chips and integrated circuits and electronic devices containing such circuits and chips, by using one or more optical elements according to optical design to form optical parts or components.

Claims

1. The component amounts are expressed in mole percent. The cation component is P 5+ : 7-27%, Al 3+ : 10-45%, Ba 2+ : 5-25%, Sr 2+ : 5 to 25%, and Ca 2+ : Contains 5 to 30% The anion component is F - : 50-90% and O 2- : Optical glass containing 10-50%.

2. The component amounts are expressed in mole percent. The cationic component is further Mg 2+ : 0-15%, Y 3+ : 0-10%, La 3+ : 0-10%, Gd 3+ : 0-10%, R + : 0 to 10%, and Sb 3+ : Contains one or more components selected from the group consisting of 0 to 1% R + Li + , Na + , and K + One or more selected from the group consisting of The anion component is further Cl - : The optical glass according to claim 1, containing 0 to 1%.

3. The component amounts are expressed in mole percent. The cation component is P 5+ : 7-27%, Al 3+ : 10-45%, Ba 2+ : 5-25%, Sr 2+ : 5-25%, Ca 2+ : 5-30%, Mg 2+ : 0-15%, Y 3+ : 0-10%, La 3+ : 0-10%, Gd 3+ : 0-10%, R + : 0 to 10%, and Sb 3+ : Consists of 0 to 1% R + Li + , Na + , and K + One or more selected from the group consisting of The anion component is F - : 50-90%, O 2- : 10-50%, and Cl - : Optical glass consisting of 0 to 1%.

4. 4. The optical glass according to claim 1, wherein the component amounts are expressed in mole percent and the optical glass satisfies one or more of the following six conditions: 1) (Is it) 2+ +Sr 2+ +Ca 2+ ) / Ba 2+ は2.0~4.6; 2) (45%-Al 3+ ) / (15%-Mg 2+ ) is 0.3 to 5.0; 3) (Al 3+ +Mg 2+ ) / Ba 2+ is 1.5-3.5; 4) (45%-Al 3+ ) / (Gd 3+ +And 3+ +The 3+ +Li + )は2.0~80.0; 5) Mg 2+ / Al 3+ is 0 to 0.5; 6) (Al 3+ -Mg 2+ -Li + ) / P 5+ は0.5~2.5。

5. 4. The optical glass according to claim 1, wherein the component amounts are expressed in mole percent and the optical glass satisfies one or more of the following six conditions: 1) (Is it) 2+ +Sr 2+ +Ca 2+ ) / Ba 2+ は2.5~4.1; 2) (45%-Al 3+ ) / (15%-Mg 2+ ) is 0.5 to 3.0; 3) (Al 3+ +Mg 2+ ) / Ba 2+ is 2.0-3.0; 4) (45%-Al 3+ ) / (Gd 3+ +And 3+ +The 3+ +Li + )は6.0~50.0; 5) Mg 2+ / Al 3+ is 0 to 0.3; 6) (Al 3+ -Mg 2+ -Li + ) / P 5+ は1.0~2.3。

6. 4. The optical glass according to claim 1, wherein the component amounts are expressed in mole percent and the optical glass satisfies one or more of the following six conditions: 1) (Is it) 2+ +Sr 2+ +Ca 2+ ) / Ba 2+ は3.0~3.9; 2) (45%-Al 3+ ) / (15%-Mg 2+ ) is 0.6 to 2.0; 3) (Al 3+ +Mg 2+ ) / Ba 2+ is 2.3-2.7; 4) (45%-Al 3+ ) / (Gd 3+ +And 3+ +The 3+ +Li + )は8.0~35.0; 5) Mg 2+ / Al 3+ is 0 to 0.1; 6) (Al 3+ -Mg 2+ -Li + ) / P 5+ は1.3~2.1。

7. The component amounts are expressed in mole percent. P 5+ : 11-24%, Al 3+ : 18-40%, Ba 2+ : 9-21%, Sr 2+ : 8-21%, Ca 2+ : 10-25%, Mg 2+ : 0-10%, Y 3+ : 0-5%, La 3+ : 0-5%, Gd 3+ : 0-5%, R + : 0 to 6%, and Sb 3+ : Contains one or more components selected from the group consisting of 0 to 0.5% R + Li + , Na + , and K + One or more selected from the group consisting of:

4. The optical glass according to claim 1.

8. The component amounts are expressed in mole percent. P 5+ : 15-20%, Al 3+ : 24-35%, Ba 2+ : 12-19%, Sr 2+ : 11-17%, Ca 2+ : 15-20%, Mg 2+ : 0-5%, Y 3+ : 0-3%, La 3+ : 0-2%, Gd 3+ : 0-3%, R + : 0 to 3%, and Sb 3+ : Contains one or more components selected from the group consisting of 0 to 0.3% R + Li + , Na + , and K + 4. The optical glass according to claim 1, wherein the optical glass is one or more selected from the group consisting of:

9. The component amounts are expressed in mole percent. F - : 60-80%, O 2- : 20-40%, and Cl - 4. The optical glass according to claim 1, further comprising 0 to 0.5% of one or more components selected from the group consisting of:

10. The component amount is expressed in mole percent, and F - : 67-75%, O 2- : 25-33%, and Cl - 4. The optical glass according to claim 1, further comprising 0 to 0.3% of one or more components selected from the group consisting of:

11. 4. The optical glass according to claim 1, which satisfies one or more of the following ten conditions: 1) Refractive index n d is 1.46 to 1.52, 2) Abbe number ν d 81 to 89, 3) λ 80 is 340 nm or less, 4) λ 5 が265nm or less, 5) Density ρ is 3.90 g / cm 3 below, 6) Transition temperature T g is below 500℃, 7) Acid resistance RA is 3 or higher, 8) Moisture resistance stability RC is Class 2 or higher, 9) Stripes are C grade or higher; 10) Crystallization resistance is class D or higher.

12. 4. The optical glass according to claim 1, which satisfies one or more of the following ten conditions: 1) Refractive index n d is 1.48 to 1.50, 2) Abbe number ν d 84 to 87, 3) λ 80 is 320 nm or less, 4) λ 5 is 245 nm or less, 5) Density ρ = 3.74 g / cm³ 3 the following, 6) Transition temperature T g is 480℃ or less, 7) Acid resistance RA is 2 or higher, 8) Moisture resistance stability RC is Class 1, 9) Stripes are grade A, 10) Crystallization resistance is Class A.

13. An optical element comprising the optical glass according to claim 1 or 3.

14. An optical instrument comprising the optical glass according to claim 1 or 3.

15. An optical instrument comprising the optical element according to claim 13.