Optical glass, optical element and optical instrument

Abstract

The invention provides optical glass with relatively low transition temperature and special dispersion. The optical glass comprises the following components in percentage by weight: 22 to 40 percent of SiO2; 5.5% to 13% of Al2O3; 10.5% to 21% of B2O3; 6 to 25 percent of Nb2O5; zrO2: 2 to 23%; 6%-13% of MgO; r2O is one or more selected from the group consisting of Li2O, Na2O and K2O. The invention also discloses a preparation method of the catalyst. Through reasonable component design, the optical glass obtained by the invention has expected refractive index and Abbe number, and also has lower transformation temperature and lower delta Pg.F, thereby meeting the application of high-end photoelectric products.

Description

Technical Field

[0001] The invention relates to an optical glass, in particular to an optical glass with a lower transition temperature and special dispersion, and an optical element and an optical instrument made of the optical glass. Background Art

[0002] Optical glass is a key material used to manufacture lenses, prisms, reflectors and windows in optical instruments. Its optical properties are crucial to the design of optical systems. Chromatic aberration in optical glass is one of the main issues affecting the performance of high-precision optical systems. Therefore, in the optical design process, special optical materials are needed to construct a lens combination that can eliminate chromatic aberration. Special dispersion optical glass has a negative relative partial dispersion deviation value (ΔP g,F ), can be used to eliminate secondary spectra in optical systems, improve color reproduction and geometric accuracy. By combining glasses with different dispersion characteristics, chromatic aberration at the edge of a large field of view and chromatic aberration in long focal length lenses can be corrected more effectively, thereby improving imaging quality.

[0003] Precision compression molding of optical glass is a high-precision optical component processing technology. It uses the thermorheological properties of glass to make the glass replicate the surface shape of the mold at a temperature suitable for molding, and then forms an optical component after cooling. Precision compression molding of optical glass includes direct compression molding and secondary compression molding, which has high precision and consistency and can be used for mass production of optical components. In addition, precision compression molding simplifies the preparation process and does not require traditional rough grinding, fine grinding, polishing, edge grinding and centering processes. It can save a lot of production equipment, tooling and auxiliary materials, plant area and technical workers. Especially for aspheric lenses, precision compression molding technology has huge advantages. Precision compression molding is mainly divided into four stages: heating, molding, cooling and demolding. The heating process requires the glass preform to be heated to 25℃ to 50℃ above the glass transition temperature, soften the glass, and then pressurize it. If the transition temperature of the glass is too high, the mold coating will be damaged, resulting in a reduction in the service life of the mold material and the molding machine, an increase in the cost of compression molding, and it is also not conducive to subsequent cooling and demolding. Glass with a low transition temperature not only helps to increase the service life of the mold and reduce the requirements for equipment, but also due to its lower transition temperature, it can be molded at a lower temperature, which reduces heating time and energy consumption, thereby improving processing efficiency, while also being more energy-saving and environmentally friendly. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an optical glass with lower transition temperature and special dispersion.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] The optical glass comprises, expressed in weight percentage, 22-40% SiO2, 5.5-13% Al2O3, 10.5-21% B2O3, 6-25% Nb2O5, 2-23% ZrO2, 6-13% MgO and 6-20% R2O, wherein R2O is one or more of Li2O, Na2O and K2O.

[0007] Furthermore, the optical glass, expressed in weight percentage, also contains: P2O5: 0-5%; and / or BaO: 0-2%; and / or SrO: 0-1%; and / or CaO: 0-2.5%.

[0008] The optical glass comprises, expressed in weight percentage, SiO2: 22-40%; Al2O3: 5.5-13%; B2O3: 10.5-21%; Nb2O5: 6-25%; ZrO2: 2-23%; MgO: 6-13%; R2O: 6-20%; P2O5: 0-5%; BaO: 0-2%; SrO: 0-1%; and CaO: 0-2.5%, wherein R2O is one or more of Li2O, Na2O, and K2O.

[0009] Furthermore, the components of the optical glass are expressed in weight percentage, wherein: Al2O3 / (SiO2+B2O3+Al2O3) is 0.12-0.23, preferably Al2O3 / (SiO2+B2O3+Al2O3) is 0.13-0.19.

[0010] Furthermore, the components of the optical glass are expressed in weight percentage, wherein: Nb2O5 / MgO is 0.61 to 3.54, preferably Nb2O5 / MgO is 1.20 to 2.85.

[0011] Furthermore, the components of the optical glass are expressed in weight percentage, wherein: R2O / (Al2O3+B2O3) is 0.29-0.81, preferably R2O / (Al2O3+B2O3) is 0.51-0.75, and the R2O is one or more of Li2O, Na2O, and K2O.

[0012] Furthermore, the components of the optical glass are expressed in weight percentage, wherein: Nb2O5 / Na2O is 1.0-3.86, preferably Nb2O5 / Na2O is 1.5-2.95.

[0013] Furthermore, the components of the optical glass are expressed in weight percentage, wherein: SiO2: 28-38%; and / or Al2O3: 8-12%; and / or B2O3: 15-20%; and / or Nb2O5: 8-16%; and / or ZrO2: 5-17%; and / or MgO: 6-10%; and / or R2O: 11-18%; and / or P2O5: 0-3%, wherein R2O is one or more of Li2O, Na2O, and K2O.

[0014] Furthermore, the optical glass, its components are expressed in weight percentage, wherein: Li2O: 0-5%, preferably Li2O: 0-3%; and / or Na2O: 4-8%, preferably Na2O: 6-8%; and / or K2O: 0-12%, preferably K2O: 5-10%.

[0015] Furthermore, the optical glass does not contain Ta2O5.

[0016] Furthermore, the refractive index n of the optical glass is d 1.51 to 1.60, preferably 1.52 to 1.58; and / or Abbe number v d 50 to 60, preferably 52 to 58; and / or relative partial dispersion P g,F 0.5400 to 0.5500, preferably 0.5420 to 0.5480; and / or relative partial dispersion deviation value ΔP g,F It is -0.005 or less, preferably -0.007 or less.

[0017] Furthermore, the density of the optical glass is 2.80 g / cm 3 Below, preferably 2.75g / cm 3 Below, more preferably 2.70g / cm 3 Below; and / or thermal expansion coefficient α 30 / 300℃ 120×10 -7 / K or less, preferably 115×10 -7 / K or less, more preferably 110×10 -7 / K or less; and / or weather resistance CR is 2 or more, preferably 1; and / or transition temperature T g 520°C or less, preferably 500°C or less, more preferably 480°C or less; and / or softening temperature T S The temperature is 560°C or lower, preferably 540°C or lower, and more preferably 520°C or lower.

[0018] The glass preform is made of the above optical glass.

[0019] The optical element is made of the above optical glass, or made of the above glass preform.

[0020] An optical instrument contains the above optical glass and / or contains the above optical element.

[0021] The beneficial effect of the present invention is that through reasonable component design, the optical glass obtained by the present invention has a desired refractive index and Abbe number, and also has a lower transition temperature and a lower ΔP g.F , to meet the application of high-end optoelectronic products. DETAILED DESCRIPTION

[0022] The following will describe the embodiments of the optical glass of the present invention in detail, but the present invention is not limited to the following embodiments, and can be implemented by appropriate changes within the scope of the purpose of the present invention. In addition, although there are appropriate omissions of descriptions of the repeated descriptions, the gist of the invention will not be limited thereby, and in the following content, the optical glass of the present invention is sometimes referred to as glass.

[0023] [Optical glass]

[0024] The following is an explanation of the range of each component (ingredient) of the optical glass of the present invention. In the present invention, unless otherwise specified, the content, total content, and total content of each component are all expressed in weight percentage (wt%), that is, the content, total content, and total content of each component are expressed in weight percentage relative to the total amount of glass material converted into oxide composition. Here, the "composition converted into oxide" means that when the oxides, complex salts, hydroxides, etc. used as raw materials for the optical glass components of the present invention decompose and transform into oxides during melting, the total amount of the oxide material is taken as 100%.

[0025] Unless otherwise specified in specific circumstances, the numerical ranges listed in the present invention include upper and lower limits, "above" and "below" include endpoint values, and all integers and fractions included in the range, without being limited to the specific values ​​listed when the range is defined. "And / or" referred to herein is inclusive, for example, "A and / or B" means only A, or only B, or both A and B.

[0026] <Essential Components and Optional Components>

[0027] SiO2 is an important component in the glass of the present invention, and as the main network former, it participates in forming the network skeleton of the glass. By adjusting the content of SiO2, the physical and chemical properties of the glass can be greatly adjusted to meet various different usage requirements. At the same time, in special dispersion optical glass, the content of SiO2 will affect the refractive index and dispersion characteristics of the glass. In the present invention, the content of SiO2 is made to be above 22% to achieve the desired physical and chemical properties of the present invention, and the content of SiO2 is preferably above 28%. However, too high a content of SiO2 will lead to an increase in the viscosity of the glass and an increase in the transition temperature of the glass. Therefore, the content of SiO2 in the present invention is below 40%, preferably below 38%.

[0028] Al2O3 is a key component involved in the network structure of the glass of the present invention. In the present invention, Al2O3 can improve the weather resistance of the glass. At the same time, in the special dispersion optical glass, the change in the content of Al2O3 will lead to changes in the content of [BO4] and [BO3] in the glass network. When the glass contains two oxides, Al2O3 and B2O3, and there is free oxygen, Al2O3 preferentially captures the free oxygen and is converted into [AlO4] to enter the glass network structure, followed by [BO3] capturing the free oxygen and being converted into [BO4]. Finally, the excess free oxygen breaks the Si-O bond. The present invention contains a certain amount of Al2O3, which can effectively reduce the relative partial dispersion deviation value (ΔP g,F ). Therefore, the content of Al2O3 in the present invention is 5.5% or more, preferably 8% or more. However, too high a content of Al2O3 will increase the viscosity of the glass and increase the transition temperature. Therefore, the content of Al2O3 in the present invention is 13% or less, preferably 12% or less.

[0029] B2O3 is also an important component in the glass of the present invention and is a key component of the optical glass with negative special dispersion. The main factor affecting the relative partial dispersion deviation value in the glass of the present invention is the content of [BO3] in the glass. [BO3] has a short infrared absorption characteristic. Therefore, increasing the content of [BO3] in the glass

[0030] The content of [BO3] can effectively reduce the relative partial dispersion deviation value (ΔP g,F ), thereby improving the special dispersion performance and better eliminating the secondary spectrum. The content of B2O3 in the present invention is more than 10.5%, preferably more than 15%. However, too high B2O3 will cause the anti-crystallization performance of the glass to deteriorate, which is not conducive to the precision pressing process of optical glass. Therefore, the content of B2O3 in the present invention is less than 21%, preferably less than 20%.

[0031] In the optical glass of the present invention, SiO2, B2O3 and Al2O3 are the main network-forming oxides. The content of Al2O3 has a great influence on the network structure formed by SiO2 and B2O3 in the glass. In some embodiments, if the value of Al2O3 / (SiO2+B2O3+Al2O3) is too low, there is less [BO3] in the glass, the special dispersion performance of the glass is poor, and the proportion of Al2O3 is too small, and the weather resistance of the glass deteriorates. If the value of Al2O3 / (SiO2+B2O3+Al2O3) is too high, the high-temperature viscosity of the glass is large. Therefore, appropriate Al2O3 / (SiO2+B2O3+Al2O3) can not only enable the glass to obtain excellent special dispersion performance and improve the weather resistance of the glass, but also obtain a lower high-temperature viscosity, which is beneficial to the melting and clarification of the glass. Therefore, the preferred Al2O3 / (SiO2+B2O3+Al2O3) is 0.12 to 0.23, and the more preferred Al2O3 / (SiO2+B2O3+Al2O3) is 0.13 to 0.19.

[0032] Nb2O5 can effectively increase the refractive index of glass. At the same time, Nb2O5 can increase the medium-wave partial dispersion, but will not significantly increase the short-wave partial dispersion, thereby increasing the negative special dispersion of the optical glass. In the present invention, more than 6% of Nb2O5 is contained to increase the refractive index and relative partial dispersion deviation value of the glass, and the content of Nb2O5 is preferably more than 8%. However, excessive Nb2O5 will cause the refractive index of the glass to be too high and the Abbe number to be too small, which will lead to the relative partial dispersion deviation value performance of the glass to deteriorate. Therefore, the content of Nb2O5 in the present invention is less than 25%, preferably less than 16%.

[0033] ZrO2 is the network outer oxide of the glass of the present invention, which can improve the physical and chemical properties of the glass and the thermal stability of the glass. 4+ The ion field strength is large, which can attract the free oxygen ions around it, resulting in an increase in oxygen vacancies, promoting the transformation of [BO4] to [BO3], and thus reducing the relative partial dispersion deviation value of the glass (ΔP g,F ), improving the special dispersion performance. In the present invention, the content of ZrO2 is more than 2%, preferably more than 5%. The melting temperature of ZrO2 is relatively high, and excessive ZrO2 will cause the melting and clarification performance of the glass to deteriorate, the viscosity to increase, and the glass transition temperature to increase. In addition, as the ZrO2 content reaches a certain level, the anti-crystallization performance of the glass also deteriorates. Therefore, the content of ZrO2 in the present invention is less than 23%, preferably less than 17%.

[0034] MgO is an alkaline earth metal oxide. A certain amount of MgO can reduce the crystallization tendency and crystallization speed of glass, while increasing the viscosity of glass at high temperature and improving the material properties of glass. However, excessive MgO will lead to poor anti-crystallization performance of glass. Therefore, the content of MgO is 6-13%, preferably 6-10%.

[0035] In some embodiments, the ratio of Nb2O5 to MgO is controlled within the range of 0.61 to 3.54. An appropriate amount of MgO can promote the growth of Nb2O5. 5+ Ions enter the glass network to form Si-O-Nb bonds, which can improve the special dispersion properties of the glass, reduce the thermal expansion coefficient of the glass, and improve the thermal shock resistance of the glass. Therefore, the preferred Nb2O5 / MgO is 0.61 to 3.54, and the more preferred Nb2O5 / MgO is 1.20 to 2.85.

[0036] BaO, SrO, and CaO are network-external oxides of glass, which can improve the chemical stability and mechanical strength of glass. BaO can also improve the density, refractive index, and transmittance of glass. However, the content of BaO, SrO, and CaO should not be too much, as too much content will increase the crystallization tendency of glass, and BaO reacts with oxygen to produce secondary bubbles in the clarification stage. Therefore, the content of BaO in the present invention is 0-2%, the content of SrO is 0-1%, and the content of CaO is 0-2.5%.

[0037] R2O (R2O is one or more of Li2O, Na2O, K2O) can effectively improve the melting performance of glass, but too high a content thereof will lead to poor chemical stability and anti-crystallization performance of glass. Therefore, the content of R2O in the present invention is 6-20%, preferably 11-18%.

[0038] In some embodiments, if the value of R2O / (Al2O3+B2O3) is too large, [BO3] in the glass will capture free oxygen and convert into [BO4], which will deteriorate the special dispersion performance of the glass. At the same time, the degree of glass network connection will decrease, the weather resistance of the glass will decrease, and the thermal expansion coefficient will increase. However, if the value of R2O / (Al2O3+B2O3) is too small, the difficulty of glass chemistry will increase, and the transition temperature and density of the glass will increase. Therefore, preferably R2O / (Al2O3+B2O3) is 0.29 to 0.81, and more preferably R2O / (Al2O3+B2O3) is 0.51 to 0.75.

[0039] Under certain conditions, that is, when the O / Si ratio is small, Li2O can break bonds in the glass of the present invention, reduce the glass viscosity, and reduce the glass transition temperature, but a large amount of Li2O will increase the tendency of glass crystallization. Therefore, the content of Li2O in the present invention is 0-5%, preferably 0-3%. The presence of Na2O in the glass can break bonds and reduce the viscosity of the glass, but excessive Na2O will reduce the thermal stability, chemical stability and mechanical strength of the glass. Therefore, the content of Na2O in the present invention is 4-8%, preferably 6-8%. The role of K2O in the glass of the present invention is similar to that of Na2O, but K + Ion ratio Na + The ion radius of the ion is large, and the glass with a high K2O content has a higher viscosity than the glass with a high Na2O content, and the glass has a low crystallization tendency and a high transmittance. The appropriate inclusion of K2O in the present invention can ensure the low transition temperature, excellent anti-crystallization and desired optical properties of the glass. Therefore, the content of K2O in the present invention is 0 to 12%, preferably 5 to 10%.

[0040] In some embodiments, the ratio of Nb2O5 to Na2O is controlled within the range of 1.0 to 3.86. Na2O can provide an appropriate amount of free oxygen in the glass, thereby increasing the content of Nb2O5. 5+ The ions are in the glass network in the form of [NbO6] hexacoordination, forming Si-O-Nb bonds, which improve the special dispersion properties of the glass, reduce the thermal expansion coefficient of the glass, and improve the thermal shock resistance of the glass. Therefore, the preferred Nb2O5 / Na2O is 1.0 to 3.86, and the more preferred Nb2O5 / Na2O is 1.5 to 2.95.

[0041] P2O5 is a glass network intermediate oxide. In optical glass, it has a great influence on the dispersion of glass. A certain content of P2O5 can effectively reduce the Abbe number of glass and obtain optical glass with low dispersion. However, the content of P2O5 should not be too much. In the present invention, excessive P2O5 will lead to reduced stability of glass and decreased anti-crystallization performance. Therefore, the content of P2O5 in the present invention is 0-5%, preferably 0-3%.

[0042] Ta2O5 can increase the refractive index of glass, but it is not conducive to lowering the transition temperature of glass and the precision pressing process of optical glass; at the same time, Ta2O5 is expensive and is not conducive to reducing the production cost of glass. Therefore, in some embodiments of the present invention, it is preferred not to contain Ta2O5.

[0043] <Components that should not be contained>

[0044] In the glass of the present invention, even if oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag and Mo are contained alone or in combination in small amounts, the glass will be colored and absorption will occur at specific wavelengths in the visible light region, thereby weakening the property of the present invention of improving the visible light transmittance. Therefore, it is preferably substantially free of oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag and Mo, especially for optical glasses that require transmittance at wavelengths in the visible light region.

[0045] The oxides of Th, Cd, Tl, Os, Be and Se have a tendency to be controlled in recent years as harmful chemical substances, and environmental protection measures are necessary not only in the manufacturing process of glass, but also in the processing process and the disposal after productization. Therefore, in the case of paying attention to the impact on the environment, it is preferred that they are not actually contained except for being inevitably mixed in. Thus, the optical glass does not actually contain substances that pollute the environment. Therefore, even if special environmental countermeasures are not taken, the optical glass of the present invention can be manufactured, processed and discarded.

[0046] In order to achieve environmental friendliness, the optical glass of the present invention preferably does not contain As2O3 and PbO.

[0047] The "does not contain" and "0%" recorded in this article mean that the compound, molecule or element is not intentionally added as a raw material to the optical glass of the present invention; however, as raw materials and / or equipment for producing optical glass, there will be certain impurities or components that are not intentionally added, which will be contained in a small amount or trace amount in the final optical glass, and this situation is also within the scope of protection of the patent of this invention.

[0048] Next, the properties of the optical glass of the present invention will be described.

[0049] <Refractive Index and Abbe Number>

[0050] The refractive index of optical glass (n d ) and the Abbe number (ν d ) Tested according to the method specified in GB / T 7962.1-2010.

[0051] In some embodiments, the refractive index (n d The lower limit of the refractive index (n) of the optical glass of the present invention is 1.51, and the preferred lower limit is 1.52. d ) is 1.60, and the preferred upper limit is 1.58.

[0052] In some embodiments, the Abbe number (ν d ) has a lower limit of 50, preferably a lower limit of 52. In some embodiments, the Abbe number (ν d) has an upper limit of 60, and a preferred upper limit of 58.

[0053] <density>

[0054] The density (ρ) of optical glass is tested according to the method specified in GB / T7962.20-2010.

[0055] In some embodiments, the density (ρ) of the optical glass of the present invention is 2.80 g / cm 3 Below, preferably 2.75g / cm 3 Below, more preferably 2.70g / cm 3 the following.

[0056] <Coefficient of Thermal Expansion>

[0057] Thermal expansion coefficient of optical glass (α 30 / 300℃ ) The data at 30-300℃ were tested according to the method specified in GB / T7962.16-2010.

[0058] In some embodiments, the thermal expansion coefficient (α 30 / 300℃ ) is 120×10 -7 / K or less, preferably 115×10 -7 / K or less, more preferably 110×10 -7 / K or less.

[0059] <Weather resistance>

[0060] The test method for weather resistance (CR) of optical glass is as follows: place the sample in a test box with a saturated water vapor environment of 90% relative humidity, alternately cycle every 1 hour at 40-50°C, and cycle for 15 cycles. The weather resistance category is divided according to the change in turbidity before and after the sample is placed. The weather resistance classification is shown in Table 1:

[0061] Table 1.

[0062]

[0063] In some embodiments, the weather resistance (CR) of the optical glass of the present invention is Class 2 or higher, preferably Class 1.

[0064] <Relative partial dispersion and relative partial dispersion deviation value>

[0065] The relative partial dispersion (P g,F ) and relative partial dispersion deviation (ΔP g,F ) origin.

[0066] The relative partial dispersion for wavelengths x and y is expressed by the following equation (1):

[0067] P x,y =(n x -n y ) / (n F -n C ) (1)

[0068] According to the Abbe number formula, for most so-called "normal glasses" (H-K6 and F4 are selected as "normal glasses" below), the following formula (2) is valid:

[0069] P x,y =m x,y ·v d +b x,y (2)

[0070] This linear relationship is based on P x,y is the vertical coordinate, v d It is represented by the horizontal axis, where m x,y is the slope, b x,y is the intercept.

[0071] As is known to all, the correction of the secondary spectrum, i.e. the achromatization of more than two wavelengths, requires at least one glass that does not conform to the above formula (2) (i.e. its P x,y The deviation value deviates from Abbe's empirical formula), and its deviation value is expressed as ΔP x,y If it is expressed, then each P x,y -v d The point is shifted by ΔP relative to the "normal line" that conforms to the above formula (2) x,y Quantity, so that the ΔP of each glass x,y The value can be obtained using the following formula (3):

[0072] P x,y =m x,y ·v d +b x,y +ΔP x,y (3)

[0073] Therefore, ΔP x,y It quantitatively represents the deviation characteristics of special dispersion compared with "normal glass".

[0074] Therefore, the relative partial dispersion (P g,F ) and relative partial dispersion deviation (ΔP g,F ) is calculated as follows (4) and (5):

[0075] P g,F =(n g -n F ) / (n F -n C ) (4)

[0076] ΔP g,F =P g,F -0.6457+0.001703v d (5)

[0077] In some embodiments, the relative partial dispersion (P g,F ) is 0.5400 to 0.5500, preferably 0.5420 to 0.5480.

[0078] In some embodiments, the relative partial dispersion deviation value (ΔP g,F ) is -0.005 or less, preferably -0.007 or less.

[0079] <Transition Temperature>

[0080] Transition temperature of optical glass (T g ) Tested according to the method specified in the national standard "GB / T7962.16-2010".

[0081] In some embodiments, the transition temperature (T g ) is 520°C or lower, preferably 500°C or lower, and more preferably 480°C or lower.

[0082] <Softening temperature>

[0083] Softening temperature of optical glass (T S ) Tested according to the method specified in the national standard "GB / T7962.16-2010".

[0084] In some embodiments, the softening temperature (T S ) is 560°C or lower, preferably 540°C or lower, and more preferably 520°C or lower.

[0085] [Method for producing optical glass]

[0086] The manufacturing method of the optical glass of the present invention is as follows: the glass of the present invention is produced using conventional raw materials and processes, including but not limited to using oxides, hydroxides, complex salts (such as carbonates, nitrates, sulfates, phosphates, metaphosphates, etc.), boric acid, etc. as raw materials, and after mixing according to conventional methods, the prepared furnace materials are put into a melting furnace (such as platinum or platinum alloy crucible) at 1150-1300°C for melting, and after clarification and homogenization, a homogeneous molten glass without bubbles and undissolved substances is obtained, and the molten glass is cast in a mold and annealed. Those skilled in the art can appropriately select raw materials, process methods and process parameters according to actual needs.

[0087] [Glass preforms and optical components]

[0088] The prepared optical glass can be used to make a glass preform by means of direct drop molding, grinding, or compression molding such as hot press molding. That is, the molten optical glass can be directly precision drop molded into a glass precision preform, or the glass preform can be made by mechanical processing such as grinding and grinding, or the preform for compression molding made of the optical glass can be made by hot press molding and then grinding. It should be noted that the means for preparing the glass preform are not limited to the above means.

[0089] As described above, the optical glass of the present invention is useful for various optical elements and optical designs, and it is particularly preferred to form a preform from the optical glass of the present invention and use the preform to perform re-hot pressing, precision stamping, etc. to produce optical elements such as lenses and prisms.

[0090] The glass preform and optical element of the present invention are both formed of the optical glass of the present invention. The glass preform of the present invention has the excellent properties of optical glass; the optical element of the present invention has the excellent properties of optical glass, and can provide various optical elements such as lenses and prisms with high optical value.

[0091] Examples of the lens include various lenses having spherical or aspherical lens surfaces, 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.

[0092] [Optical instruments]

[0093] The optical element formed by the optical glass of the present invention can be used to manufacture optical instruments such as photographic equipment, video equipment, projection equipment, display equipment, vehicle-mounted equipment and monitoring equipment.

[0094] Example

[0095] <Optical Glass Example>

[0096] In order to further clearly illustrate and describe the technical solutions of the present invention, the following non-limiting examples are provided.

[0097] This embodiment adopts the above optical glass manufacturing method to obtain optical glasses having the compositions shown in Tables 2 to 4. In addition, the properties of each glass are measured by the testing method described in the present invention, and the measurement results are shown in Tables 2 to 4.

[0098] Table 2.

[0099]

[0100]

[0101] Table 3.

[0102]

[0103] Table 4.

[0104]

[0105]

[0106] <Glass Preform Example>

[0107] The glass obtained from optical glass examples 1 to 24# is used, for example, by grinding processing, or by molding methods such as hot pressing, precision stamping, etc., to make preforms of various lenses, prisms, etc., such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses.

[0108] <Optical Element Embodiment>

[0109] The preforms obtained in the above-mentioned glass preform embodiments are annealed to reduce the internal stress of the glass and fine-tune the refractive index so that the optical properties such as the refractive index reach the desired values.

[0110] Next, each preform is 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. The surface of the obtained optical element may be coated with an anti-reflection film.

[0111] <Optical Instrument Embodiment>

[0112] The optical element obtained by the above-mentioned optical element embodiment is optically designed to form an optical component or optical assembly by using one or more optical elements, and can be used in, for example, imaging equipment, sensors, microscopes, medical technology, digital projection, communications, optical communication technology / information transmission, optics / lighting in the automotive field, lithography technology, excimer lasers, wafers, computer chips, and integrated circuits and electronic devices including such circuits and chips.

Claims

1. Optical glass, characterized in that: Its components are expressed in weight percentage and contain: SiO2: 22-40%; Al2O3: 5.5-13%; B2O3: 10.5-21%; Nb2O5: 6-25%; ZrO2: 2-23%; MgO: 6-13%; R2O: 6-20%, wherein R2O is one or more of Li2O, Na2O and K2O.

2. The optical glass according to claim 1, characterized in that: Its components are expressed in weight percentage and further contain: P2O5: 0-5%; and / or BaO: 0-2%; and / or SrO: 0-1%; and / or CaO: 0-2.5%.

3. Optical glass, characterized in that: Its components, expressed in weight percentage, are SiO2: 22-40%; Al2O3: 5.5-13%; B2O3: 10.5-21%; Nb2O5: 6-25%; ZrO2: 2-23%; MgO: 6-13%; R2O: 6-20%; P2O5: 0-5%; BaO: 0-2%; SrO: 0-1%; CaO: 0-2.5%, wherein R2O is one or more of Li2O, Na2O, and K2O.

4. The optical glass according to any one of claims 1 to 3, characterized in that: Its components are expressed in weight percentage, wherein: Al2O3 / (SiO2+B2O3+Al2O3) is 0.12-0.23, preferably Al2O3 / (SiO2+B2O3+Al2O3) is 0.13-0.

19.

5. The optical glass according to any one of claims 1 to 3, characterized in that: Its components are expressed in weight percentage, wherein: Nb2O5 / MgO is 0.61 to 3.54, preferably Nb2O5 / MgO is 1.20 to 2.

85.

6. The optical glass according to any one of claims 1 to 3, characterized in that: Its components are expressed in weight percentage, wherein: R2O / (Al2O3+B2O3) is 0.29-0.81, preferably R2O / (Al2O3+B2O3) is 0.51-0.75, and the R2O is one or more of Li2O, Na2O, and K2O.

7. The optical glass according to any one of claims 1 to 3, characterized in that: Its components are expressed in weight percentage, wherein: Nb2O5 / Na2O is 1.0-3.86, preferably Nb2O5 / Na2O is 1.5-2.

95.

8. The optical glass according to any one of claims 1 to 3, characterized in that: Its components are expressed in weight percentage, wherein: SiO2: 28-38%; and / or Al2O3: 8-12%; and / or B2O3: 15-20%; and / or Nb2O5: 8-16%; and / or ZrO2: 5-17%; and / or MgO: 6-10%; and / or R2O: 11-18%; and / or P2O5: 0-3%, wherein R2O is one or more of Li2O, Na2O, and K2O.

9. The optical glass according to any one of claims 1 to 3, characterized in that: Its components are expressed in weight percentage, wherein: Li2O: 0-5%, preferably Li2O: 0-3%; and / or Na2O: 4-8%, preferably Na2O: 6-8%; and / or K2O: 0-12%, preferably K2O: 5-10%.

10. The optical glass according to claim 1 or 2, characterized in that: The optical glass does not contain Ta2O5.

11. The optical glass according to any one of claims 1 to 3, characterized in that: The refractive index n of the optical glass d 1.51 to 1.60, preferably 1.52 to 1.58; and / or Abbe number v d 50 to 60, preferably 52 to 58; and / or relative partial dispersion P g,F 0.5400 to 0.5500, preferably 0.5420 to 0.5480; and / or relative partial dispersion deviation value ΔP g,F It is -0.005 or less, preferably -0.007 or less.

12. The optical glass according to any one of claims 1 to 3, characterized in that: The density of the optical glass is 2.80 g / cm 3 Below, preferably 2.75g / cm 3 Below, more preferably 2.70g / cm 3 Below; and / or thermal expansion coefficient α 30 / 300℃ 120×10 -7 / K or less, preferably 115×10 -7 / K or less, more preferably 110×10 -7 / K or less; and / or weather resistance CR is 2 or more, preferably 1; and / or transition temperature T g 520°C or less, preferably 500°C or less, more preferably 480°C or less; and / or softening temperature T S The temperature is 560°C or lower, preferably 540°C or lower, and more preferably 520°C or lower.

13. A glass preform, characterized in that: Made of the optical glass described in any one of claims 1 to 12.

14. An optical element, characterized in that The optical glass is made of the optical glass described in any one of claims 1 to 12, or the glass preform described in claim 13.

15. An optical instrument, characterized in that Contains the optical glass according to any one of claims 1 to 12, and / or contains the optical element according to claim 14.

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