Optical glass, glass preform, optical element, and optical apparatus

Abstract

To provide an optical glass having a low transition temperature.SOLUTION: The present invention provides an optical glass, comprising the following components by weight percentage: SiO2:1 to 10%, B2O3:18 to 31%, La2O3:20 to 35%, ZnO: 19 to 32%, Gd2O3 + Y2O3:1 to 14%, and Nb2O5 + WO3:0.5 to 12%. Through reasonable composition design, the optical glass of the present invention has the expected refractive index and Abbe number, and has a relatively low transition temperature.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to optical glasses, and more particularly to optical glasses having a relatively low transition temperature, and glass preforms, optical elements and optical instruments made therefrom. [Background technology]

[0002] In recent years, advances in science and technology have led to the constant upgrading of optoelectronic information products, gradually increasing the demand for optical glass, and the requirements for its performance are also on the rise. For the same radius of curvature, the higher the refractive index of the glass, the larger the imaging field that can be obtained. As optical devices become increasingly miniaturized, the demand for high-refractive-index glass is on the rise. Optical glass with a refractive index of 1.71 to 1.79 and an Abbe number of 42 to 49 has a relatively high refractive index, making it easy to achieve miniaturization, ultra-thinness, and wide-angle lenses, and its application scenarios are widespread.

[0003] The most common method for manufacturing optical elements today is precision press molding (including direct pressing and secondary pressing). Lenses manufactured using precision press molding do not require grinding and polishing, reducing raw material consumption, labor and material costs, and environmental pollution. This technology can be used to mass-produce aspherical elements at low cost. Precision press molding involves pressing a glass preform into a high-precision mold with a predetermined product shape at a certain temperature and pressure to obtain a glass product with the finished shape and optical function. Precision press molding can be used to manufacture a variety of optical glass products, including spherical lenses, aspherical lenses, prisms, and diffraction gratings.

[0004] Precision press molding requires press molding a glass preform at high temperatures (typically above the glass transition temperature of 20 to 60°C) to transfer the highly precise mold surface to the glass product. In this process, the molding die is subjected to high temperatures and pressure, and even with the presence of a protective gas, the surface of the die is susceptible to oxidation and erosion. To extend the die's life and prevent damage to the die due to high temperatures, it is necessary to lower the press temperature. Therefore, the glass material used in press molding must have as low a transition temperature as possible. Patent Document 1 (China Patent Application Publication No. 101857358) discloses a high-refractive-index optical glass with a refractive index of 1.69 to 1.82 and an Abbe number of 33 to 46. However, its high transition temperature is disadvantageous for extending the die's service life. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Chinese Patent Application Publication No. 101857358 Summary of the Invention [Problem to be solved by the invention]

[0006] The technical problem to be solved by the present invention is to provide an optical glass having a low transition temperature. [Means for solving the problem]

[0007] The technical solutions adopted by the present invention to solve the technical problems are as follows.

[0008] (1) An optical glass containing the following components in weight percent: SiO2: 1~10%, B2O3: 18~31%, La2O3: 20~35%, ZnO: 19~32%, Gd2O3+Y2O3: 1~14%, and Nb2O5+WO3: 0.5~12%.

[0009] (2) The optical glass according to (1), further comprising, in weight percent, one or more components selected from the following group: A group consisting of ZrO2: 0-10%, Li2O: 0-8%, Na2O: 0-6%, K2O: 0-6%, RO: 0-4%, TiO2: 0-4%, Ta2O5: 0-4%, Al2O3: 0-4%, Yb2O3: 0-10%, F: 0-3%, and fining agent: 0-1%. The RO is one or more selected from the group consisting of MgO, CaO, SrO, and BaO, and the fining agent is one or more selected from the group consisting of Sb2O3, SnO, SnO2, and CeO2.

[0010] (3) Optical glass containing the following components in weight percent: SiO2: 1-10%, B2O3: 18-31%, La2O3: 20-35%, ZrO2: 0-10%, ZnO: 19-32%, Gd2O3 + Y2O3: 1-14%, Nb2O5 + WO3: 0.5-12%, Li2O: 0-8%, Na2O: 0-6%, K2O: 0-6%, RO: 0-4%, TiO2: 0-4%, Ta2O5: 0-4%, Al2O3: 0-4%, Yb2O3: 0-10%, F: 0-3%, and fining agent: 0-1%. The RO is one or more selected from the group consisting of MgO, CaO, SrO, and BaO, and the fining agent is one or more selected from the group consisting of Sb2O3, SnO, SnO2, and CeO2.

[0011] (4) An optical glass according to any one of (1) to (3), which satisfies one or more of the following ten conditions: 1) ZnO / La2O3 (weight ratio) is 0.6~1.5; 2) (Gd2O3+Y2O3) / ZnO (weight ratio) is 0.05~0.6; 3) (Nb2O5+WO3) / SiO2 (weight ratio) is 0.1~5.0; 4) SiO2 / ZnO (weight ratio) is 0.05~0.45; 5) Nb2O5 / Y2O3 (weight ratio) is 0.1~5.0; 6) (WO3+Gd2O3+Ta2O5) / ZnO (weight ratio) is 1.0 or less; 7) Gd2O3 / WO3 (weight ratio) is 6.5 or less; 8) (Nb2O5+WO3) / ZnO (weight ratio) is 0.05~0.5; 9) (SiO2+WO3+La2O3) / (ZnO+Gd2O3) (weight ratio) is 0.6~2.0; 10) (B2O3+WO3) / SiO2 (weight ratio) is 2.5 to 15.0.

[0012] (5) An optical glass according to any one of (1) to (3), which satisfies one or more of the following ten conditions: 1) ZnO / La2O3 (weight ratio) is 0.8~1.3; 2) (Gd2O3+Y2O3) / ZnO (weight ratio) is 0.15~0.45; 3) (Nb2O5+WO3) / SiO2 (weight ratio) is 0.5~2.5; 4) SiO2 / ZnO (weight ratio) is 0.1-0.4; 5) Nb2O5 / Y2O3 (weight ratio) is 0.3~2.5; 6) (WO3 + Gd2O3 + Ta2O5) / ZnO (weight ratio) is 0.05~0.6; 7) Gd2O3 / WO3 (weight ratio) is 0.5~4.0; 8) (Nb2O5+WO3) / ZnO (weight ratio) is 0.08~0.4; 9) (SiO2+WO3+La2O3) / (ZnO+Gd2O3) (weight ratio) is 0.8~1.5; 10) (B2O3+WO3) / SiO2 (weight ratio) is 3.5~8.0.

[0013] (6) An optical glass according to any one of (1) to (3), which satisfies one or more of the following ten conditions: 1) ZnO / La2O3 (weight ratio) is 0.8~1.2; 2) (Gd2O3+Y2O3) / ZnO (weight ratio) is 0.2~0.4; 3) (Nb2O5+WO3) / SiO2 (weight ratio) is 0.7~1.5; 4) SiO2 / ZnO (weight ratio) is 0.15~0.35; 5) Nb2O5 / Y2O3 (weight ratio) is 0.5-1.5; 6) (WO3+Gd2O3+Ta2O5) / ZnO (weight ratio) is 0.1~0.45; 7) Gd2O3 / WO3 (weight ratio) is 1.0~3.5; 8) (Nb2O5+WO3) / ZnO (weight ratio) is 0.1~0.3; 9) (SiO2+WO3+La2O3) / (ZnO+Gd2O3) (weight ratio) is 0.8~1.3; 10) (B2O3+WO3) / SiO2 (weight ratio) is 4.0~6.0.

[0014] (7) The optical glass according to any one of (1) to (6), which contains, in weight percent, one or more components selected from the following group: The group consists of SiO2: 2-8%, B2O3: 20-29%, La2O3: 22-33%, ZrO2: 1-8%, ZnO: 20-28%, Gd2O3 + Y2O3: 2-12%, Nb2O5 + WO3: 1-10%, Li2O: 0.5-7%, Na2O: 0-3%, K2O: 0-3%, RO: 0-1%, TiO2: 0-2%, Ta2O5: 0-1%, Al2O3: 0-1%, Yb2O3: 0-2%, F: 0-1%, and fining agent: 0-0.5%. The RO is one or more selected from the group consisting of MgO, CaO, SrO, and BaO, and the fining agent is one or more selected from the group consisting of Sb2O3, SnO, SnO2, and CeO2.

[0015] (8) Contains, by weight, one or more components selected from the group consisting of SiO2: 3-7%, B2O3: 22-27%, La2O3: 24-31%, ZrO2: 1.5-5.5%, ZnO: 22-27%, Gd2O3 + Y2O3: 2.5-10%, Nb2O5 + WO3: 2-8%, Li2O: 1-5%, and fining agent: 0-0.2%. and / or The optical glass according to any one of (1) to (6), which does not contain one or more components selected from the group consisting of Na2O, K2O, RO, TiO2, Ta2O5, Al2O3, Yb2O3, and F. The RO is one or more selected from the group consisting of MgO, CaO, SrO, and BaO, and the fining agent is one or more selected from the group consisting of Sb2O3, SnO, SnO2, and CeO2.

[0016] (9) The optical glass according to any one of (1) to (8), which contains, in weight percent, one or more components selected from the following group: A group consisting of Gd2O3: 0-10%, Y2O3: 0-10%, Nb2O5: 0-10%, and WO3: 0-8%.

[0017] (10) The optical glass according to any one of (1) to (8), which contains, in weight percent, one or more components selected from the following group: A group consisting of Gd2O3: 2-7%, Y2O3: 1-5%, Nb2O5: 1-6%, and WO3: 1-3.8%.

[0018] (11) An optical glass according to any one of (1) to (10), which satisfies one or more of the following 12 conditions: 1) Refractive index n d is 1.71 to 1.79, 2) Abbe number v d 42 to 49, 3) λ 80 is 400nm or less, 4) λ5 is 350 nm or less, 5) Water resistance stability D W Class 2 or higher, 6) The upper limit of crystal precipitation temperature is 1080°C or less, 7) Young's modulus E is 10000 x 10 7 / Pa or more, 8) Thermal expansion coefficient α -30 / 70℃ is 80 x 10 -7 / K or less, 9) Density ρ is 4.50 g / cm 3 below, 10) Wear level F A is 90 to 130, 11) Transition temperature T g is 560℃ or less, 12) Knoop hardness H K is 600 x 10 7More than Pa.

[0019] (12) An optical glass according to any one of (1) to (10), which satisfies one or more of the following 12 conditions: 1) Refractive index n d is 1.73 to 1.77, 2) Abbe number v d 44~47, 3) λ 80 is 380nm or less, 4) λ5 is 330 nm or less, 5) Water resistance stability D W is Class 1, 6) The upper limit of crystal precipitation temperature is 980°C or less, 7) Young's modulus E is 11000 x 10 7 / Pa~12000×10 7 / Pa, 8) Thermal expansion coefficient α -30 / 70℃ is 65 x 10 -7 / K or less, 9) Density ρ is 4.20 g / cm 3 below, 10) Wear level F A is 100-120, 11) Transition temperature T g is 540℃ or less, 12) Knoop hardness H K is 620 x 10 7 More than Pa.

[0020] (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]

[0021] The beneficial effects of the present invention are as follows: Due to a rational component design, the optical glass of the present invention has the expected refractive index and Abbe number, and also has a low transition temperature. DETAILED DESCRIPTION OF THE INVENTION

[0022] 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 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. Hereinafter, the optical glass of the present invention may also be referred to simply as glass.

[0023] [Optical glass] The components of the optical glass of the present invention are described below. In this specification, unless otherwise specified, the content, total content, and total content of each component are expressed in weight percent (wt%), i.e., the content, total content, and total content of each component are expressed as weight percent of the total amount of glass material, converted into oxides. The term "value converted into oxide composition" used here refers to a conversion value where the total weight of oxide materials, such as oxides, complex salts, and hydroxides used as raw materials for the optical glass composition of the present invention, is taken as 100% when they are decomposed and converted into oxides during melting.

[0024] 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.

[0025] <Required and optional ingredients> B2O3 is a glass network-forming component that can maintain glass stability and improve the melting properties of glass. However, if the B2O3 content is too high, the chemical stability of the glass deteriorates, the viscosity of the glass decreases, and molding of the glass becomes difficult. If the B2O3 content is relatively low, the melting properties and crystallization resistance of the glass deteriorate, resulting in reduced productivity. Therefore, the B2O3 content is 18 to 31%, preferably 20 to 29%, and more preferably 22 to 27%.

[0026] SiO2 can increase the viscosity of the molten glass liquid, reduce the coloring of the glass, improve the thermal stability of the glass, and increase the devitrification resistance of the glass, but if the SiO2 content is too high, it becomes difficult to melt the glass and the transition temperature rises. Therefore, the SiO2 content is 1 to 10%, preferably 2 to 8%, and more preferably 3 to 7%.

[0027] La2O3 is an effective component for increasing the refractive index of glass and has a significant effect of improving the chemical stability and devitrification resistance of glass, but if its content is less than 20%, it is difficult to achieve the desired optical constants, and if its content exceeds 35%, the tendency of the glass to devitrify increases and thermal stability deteriorates. Therefore, the La2O3 content is 20 to 35%, preferably 22 to 33%, and more preferably 24 to 31%.

[0028] Gd2O3 is a highly refractive, low-dispersion component that can be added to glass to partially reduce the dispersion of the glass and improve its chemical stability. However, if its content is too high, the glass's resistance to devitrification deteriorates and its transition temperature rises. Therefore, in the present invention, the Gd2O3 content is 0 to 10%, preferably 0 to 8%, and more preferably 2 to 7%.

[0029] Although Y2O3 increases the refractive index and devitrification resistance of glass and can adjust the Young's modulus of glass, if its content exceeds 10%, the chemical stability and weather resistance of the glass deteriorate. Therefore, in the present invention, the Y2O3 content is 0 to 10%, preferably 0.5 to 7%, and more preferably 1 to 5%.

[0030] In some embodiments, by controlling the total content of Gd2O3 and Y2O3 (Gd2O3+Y2O3) within the range of 1 to 14%, the expected refractive index and Abbe number of the optical glass can be easily obtained, the chemical stability of the glass can be improved, and a decrease in crystallization resistance can be prevented. Therefore, Gd2O3+Y2O3 is preferably 1 to 14%, more preferably 2 to 12%, and even more preferably 2.5 to 10%.

[0031] Yb2O3 is a component that imparts high refractive index and low dispersion to the glass, and if its content exceeds 10%, the crystallization resistance of the glass decreases. Therefore, the Yb2O3 content is 0 to 10%, preferably 0 to 5%, and more preferably 0 to 2%. In some embodiments, it is even more preferable that Yb2O3 is not included.

[0032] ZrO2 increases the refractive index and devitrification resistance of glass and improves its chemical stability and mechanical performance, but if its content is too high, it becomes difficult to melt the glass, inclusions are likely to form inside the glass, and light transmittance decreases. Therefore, the ZrO2 content is 0 to 10%, preferably 1 to 8%, and more preferably 1.5 to 5.5%.

[0033] Nb2O5 is a highly refractive and highly dispersive component that can improve the devitrification resistance of glass and reduce the thermal expansion coefficient of glass, but if the Nb2O5 content exceeds 10%, the weather resistance and light transmittance of the glass will decrease and the glass transition temperature will increase. Therefore, in the present invention, the Nb2O5 content is 0 to 10%, preferably 0.5 to 8%, and more preferably 1 to 6%.

[0034] In some embodiments, the crystallization resistance and hardness of the glass can be improved by controlling the ratio of the Nb2O5 content to the Y2O3 content, Nb2O5 / Y2O3 (weight ratio), within the range of 0.1 to 5.0. Therefore, the Nb2O5 / Y2O3 (weight ratio) is preferably 0.1 to 5.0, and more preferably 0.2 to 3.0. Furthermore, by controlling the Nb2O5 / Y2O3 ratio within the range of 0.3 to 2.5, the thermal expansion coefficient of the glass can be further reduced and the abrasion resistance of the glass can be optimized. Therefore, the Nb2O5 / Y2O3 (weight ratio) is more preferably 0.3 to 2.5, and even more preferably 0.5 to 1.5.

[0035] Although WO3 can increase the refractive index and dispersion of glass, if its content is too high, the light transmittance of the glass decreases and the crystallization resistance during secondary press molding deteriorates. Therefore, in the present invention, the WO3 content is 0 to 8%, preferably 0.5 to 6%, and more preferably 1 to 3.8%.

[0036] In some embodiments, by controlling the total content of Nb2O5 and WO3 (Nb2O5+WO3) within the range of 0.5 to 12%, the optical glass can easily achieve the desired refractive index and Abbe number, optimize the abrasion resistance of the optical glass, and prevent an increase in coloration. Therefore, Nb2O5+WO3 is preferably 0.5 to 12%, more preferably 1 to 10%, and even more preferably 2 to 8%.

[0037] In some embodiments, the ratio (Nb2O5+WO3) / SiO2 (weight ratio) of the total content of Nb2O5 and WO3 (Nb2O5+WO3) to the content of SiO2 can be controlled within the range of 0.1 to 5.0 to enhance the hardness and chemical stability of the glass and prevent an increase in the glass transition temperature. Therefore, (Nb2O5+WO3) / SiO2 is preferably 0.1 to 5.0, more preferably 0.3 to 3.0, even more preferably 0.5 to 2.5, and even more preferably 0.7 to 1.5.

[0038] In some embodiments, the ratio of the Gd2O3 content to the WO3 content (Gd2O3 / WO3 weight ratio) can be controlled to 6.5 or less to lower the glass transition temperature and simultaneously optimize the abrasion resistance of the glass. Therefore, the Gd2O3 / WO3 weight ratio is preferably 6.5 or less, more preferably 0.1 to 5.0, even more preferably 0.5 to 4.0, and even more preferably 1.0 to 3.5.

[0039] In some embodiments, the ratio (B2O3+WO3) / SiO2 (weight ratio) of the total content of B2O3 and WO3 to the content of SiO2 can be controlled within the range of 2.5 to 15.0 to enhance the hardness and chemical stability of the glass and optimize its abrasion resistance. Therefore, the (B2O3+WO3) / SiO2 (weight ratio) is preferably 2.5 to 15.0, more preferably 3.0 to 10.0, even more preferably 3.5 to 8.0, and even more preferably 4.0 to 6.0.

[0040] ZnO increases the chemical stability of glass and can lower the high-temperature viscosity and transition temperature of glass. In the present invention, these effects are achieved by adding 19% or more of ZnO. However, if the ZnO content is too high, the crystallization resistance of the glass decreases, the high-temperature viscosity decreases, and molding becomes difficult. Therefore, the ZnO content is 19 to 32%, preferably 20 to 28%, and more preferably 22 to 27%.

[0041] In some embodiments, the thermal expansion coefficient of the glass can be reduced and the abrasion resistance of the glass can be optimized by controlling the ratio of the ZnO content to the La2O3 content (ZnO / La2O3 weight ratio) within the range of 0.6 to 1.5. Therefore, the ZnO / La2O3 weight ratio is preferably 0.6 to 1.5, more preferably 0.7 to 1.4, even more preferably 0.8 to 1.3, and even more preferably 0.8 to 1.2.

[0042] In some embodiments, the Young's modulus of the glass can be increased and the coloring degree and density of the glass can be reduced by controlling the ratio (Gd2O3+Y2O3) / ZnO (weight ratio) of the total content of Gd2O3 and Y2O3 (Gd2O3+Y2O3) to the content of ZnO within the range of 0.05 to 0.6. Therefore, the (Gd2O3+Y2O3) / ZnO (weight ratio) is preferably 0.05 to 0.6, more preferably 0.1 to 0.5, even more preferably 0.15 to 0.45, and even more preferably 0.2 to 0.4.

[0043] In some embodiments, the Young's modulus and crystallization resistance of the glass can be improved and the thermal expansion coefficient of the glass can be reduced by controlling the ratio of the SiO2 content to the ZnO content (SiO2 / ZnO weight ratio) within the range of 0.05 to 0.45. Therefore, the SiO2 / ZnO weight ratio is preferably 0.05 to 0.45, more preferably 0.1 to 0.4, and even more preferably 0.15 to 0.35.

[0044] In some embodiments, the crystallization resistance and Young's modulus of the glass can be improved and the chemical stability of the glass can be optimized by controlling the ratio (Nb2O5+WO3) / ZnO (weight ratio) of the total content of Nb2O5 and WO3 (Nb2O5+WO3) to the content of ZnO within the range of 0.05 to 0.5. Therefore, the (Nb2O5+WO3) / ZnO (weight ratio) is preferably 0.05 to 0.5, more preferably 0.08 to 0.4, and even more preferably 0.1 to 0.3.

[0045] In some embodiments, the ratio (SiO2+WO3+La2O3) / (ZnO+Gd2O3) (weight ratio) of the total content of SiO2, WO3, and La2O3 (SiO2+WO3+La2O3) to the total content of ZnO and Gd2O3 (ZnO+Gd2O3) is controlled within the range of 0.6 to 2.0, thereby enhancing the hardness and chemical stability of the glass and optimizing its abrasion resistance. Therefore, the (SiO2+WO3+La2O3) / (ZnO+Gd2O3) (weight ratio) is preferably 0.6 to 2.0, more preferably 0.7 to 1.8, even more preferably 0.8 to 1.5, and even more preferably 0.8 to 1.3.

[0046] Although Li2O can lower the glass transition temperature and improve the meltability of glass, a high Li2O content is detrimental to the chemical stability, crystallization resistance, and thermal expansion coefficient of the glass. Therefore, in the present invention, the Li2O content is 0 to 8%, preferably 0.5 to 7%, and more preferably 1 to 5%.

[0047] Na2O can improve the chemical stability of glass and enhance the crystallization resistance of the glass during secondary press molding. However, if the Na2O content is too high, it becomes difficult for the refractive index of the glass to meet the design requirements. Therefore, the Na2O content is 0 to 6%, preferably 0 to 5%, and more preferably 0 to 3%. In some embodiments, it is even more preferable that Na2O is not included.

[0048] Although K2O can improve the thermal stability and meltability of glass, if its content exceeds 6%, the devitrification resistance and chemical stability of the glass deteriorate. Therefore, in the present invention, the K2O content is 0 to 6%, preferably 0 to 5%, and more preferably 0 to 3%. In some embodiments, it is even more preferable that the glass does not contain K2O.

[0049] RO (RO is one or more selected from the group consisting of MgO, CaO, SrO, and BaO) can improve the meltability of glass and adjust the optical constants of glass, but if the content of RO exceeds 4%, the devitrification resistance of the glass decreases. Therefore, in the present invention, the content of RO is 0 to 4%, preferably 0 to 3%, and more preferably 0 to 1%. In some embodiments, it is more preferable that the glass does not contain MgO, and / or does not contain CaO, and / or does not contain SrO, and / or does not contain BaO.

[0050] Although TiO2 can increase the refractive index and dispersion of glass and improve devitrification resistance, if its content exceeds 4%, the glass's tendency to crystallize and become discolored increases, and the transition temperature rises. Therefore, in the present invention, the TiO2 content is 4% or less, preferably 3% or less, and more preferably 2% or less. In some embodiments, it is even more preferable that the glass does not contain TiO2.

[0051] Although Ta2O5 can increase the refractive index of glass and improve devitrification resistance, if its content is too high, the thermal stability of the glass decreases and the density increases, which is disadvantageous in terms of cost management of glass raw materials. Therefore, in the present invention, the Ta2O5 content is 0 to 4%, preferably 0 to 3%, and more preferably 0 to 1%. In some embodiments, it is even more preferable that Ta2O5 is not included.

[0052] In some embodiments, by controlling the ratio (WO3 + Gd2O3 + Ta2O5) / ZnO (weight ratio) of the total content of WO3, Gd2O3, and Ta2O5 (WO3 + Gd2O3 + Ta2O5) to the content of ZnO to 1.0 or less, the color intensity of the glass can be reduced while preventing a decrease in Young's modulus. Therefore, the (WO3 + Gd2O3 + Ta2O5) / ZnO (weight ratio) is preferably 1.0 or less, more preferably 0.8 or less. Furthermore, by controlling the (WO3 + Gd2O3 + Ta2O5) / ZnO (weight ratio) within the range of 0.05 to 0.6, the hardness of the glass can be further increased. Therefore, the (WO3 + Gd2O3 + Ta2O5) / ZnO (weight ratio) is more preferably 0.05 to 0.6, even more preferably 0.1 to 0.45.

[0053] Al2O3 can reduce the thermal expansion coefficient of glass and improve the thermal stability of glass. However, if the Al2O3 content is too high, the glass transition temperature increases, the high-temperature viscosity of the glass increases, and bubbles become difficult to eliminate. Therefore, the Al2O3 content is 0 to 4%, preferably 0 to 3%, and more preferably 0 to 1%. In some embodiments, it is even more preferable that the glass does not contain Al2O3.

[0054] In the present invention, the fining effect of the glass can be enhanced and the degree of bubblyness of the glass can be improved by adding 0 to 1% of one or more fining agents selected from the group consisting of Sb2O3, SnO2, SnO, and CeO2, and the content of the fining agent is preferably 0 to 0.5%, more preferably 0 to 0.2%. Because the types and contents of the components of the optical glass of the present invention are rationally designed and the degree of bubblyness is excellent, in some embodiments, it is even more preferable to not include a fining agent.

[0055] F can be used to adjust the refractive index of glass and reduce the refractive index and temperature coefficient. However, during the production process of optical glass, volatilization of F increases the environmental impact. It volatilizes from the glass surface within the temperature range of the molding process, forming inhomogeneous areas and reducing the consistency of the glass's quality and optical constants. Therefore, the F content is 0 to 3%, preferably 0 to 2%, and more preferably 0 to 1%. In some embodiments, it is even more preferable to have no F.

[0056] <Ingredients that should not be included> In the glass of the present invention, even when oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo are contained alone or in combination, even in small amounts, the glass is colored and specific wavelengths in the visible light region are absorbed, weakening the visible light transmission effect of the present invention. Therefore, in optical glasses that require wavelength transmittance in the visible light region in particular, it is preferable that they are substantially free of these metals.

[0057] In recent years, there has been a trend toward restricting the use of oxides of Th, Cd, Tl, Os, Be, and Se as hazardous 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 elements 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. Furthermore, to be environmentally friendly, it is preferable that the optical glass of the present invention does not contain As2O3 or PbO.

[0058] The terms "not added," "not containing," and "0%" used herein mean that the 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 the glass may exist in small or trace amounts in the final glass, and these are also within the scope of the present invention.

[0059] The performance 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 (n d ) is 1.79, preferably 1.78, more preferably 1.77, and even more preferably 1.765. In some embodiments, the refractive index (n d The lower limit of ) is 1.71, preferably 1.72, more preferably 1.73, and even more preferably 1.74. In some embodiments, the Abbe number (ν d ) is 49, preferably 48, more preferably 47, and even more preferably 46.5. In some embodiments, the Abbe number (ν d The lower limit of ) is 42, preferably 43, more preferably 44, and even more preferably 44.5.

[0060] <Coloring degree> The short-wave transmission spectrum characteristics of the optical glass of the present invention are determined by the coloring degree (λ 80 and λ5). 80 λ refers to the wavelength at which the glass transmittance reaches 80%. 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 having 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 is incident on the glass and passes through it with an intensity of I out When light of λ is emitted from a single plane, it is expressed as Iout / Iin, and it also includes the transmittance of the surface reflection loss at the surface of the glass. The higher the refractive index of the glass, the greater the surface reflection loss. Therefore, λ 80A small value of λ5 means that the glass itself is very little colored and has high light transmittance. The same applies to λ5. In some embodiments, the λ 80 is 400 nm or less, preferably 390 nm or less, more preferably 380 nm or less. In some embodiments, the λ5 of the optical glass of the present invention is 350 nm or less, preferably 340 nm or less, and more preferably 330 nm or less.

[0061] <Water resistance stability> Water resistance stability of optical glass (D W ) (powder method) is tested according to the method specified in "GB / T 17129". In some embodiments, the water resistance stability (D W ) is class 2 or more, preferably class 1.

[0062] <Crystal upper limit temperature> The crystallization resistance of optical glass is measured using the temperature gradient furnace method. A 180 x 10 x 10 mm sample is prepared from the glass, the sides are polished, and the sample is kept at 1200°C in a furnace with a temperature gradient (10°C / cm) at its highest temperature for 4 hours. The sample is then removed and allowed to cool naturally to room temperature, and the crystallization state of the glass is observed under a microscope. The highest temperature at which crystallization is confirmed is the upper crystallization temperature limit of the glass. In some embodiments, the upper limit of crystal precipitation temperature of the optical glass of the present invention is 1080°C or lower, preferably 1050°C or lower, more preferably 1000°C or lower, and even more preferably 980°C or lower.

[0063] <Young's modulus> The Young's modulus (E) of optical glass is calculated by measuring the longitudinal wave velocity and shear wave velocity using ultrasound and using the following formula:

[0064]

number

[0065] In some embodiments, the Young's modulus (E) of the optical glass of the present invention is 10,000×10 7 / Pa or more, preferably 10500 × 10 7 / Pa~13000×10 7 / Pa, more preferably 11000×10 7 / Pa~12000×10 7 / Pa.

[0066] <Thermal expansion coefficient> The thermal expansion coefficient of optical glass (α -30 / 70℃ ) is data measured at -30 to 70°C according to the method described in "GB / T 7962.16-2010." In some embodiments, the thermal expansion coefficient (α -30 / 70℃ ) is 80 x 10 -7 / K or less, preferably 75 × 10 -7 / K or less, more preferably 70×10 -7 / K or less, more preferably 65×10 -7 / K or less.

[0067] <density> The density (ρ) of optical glass is tested according to the method specified in "GB / T 7962.20-2010". In some embodiments, the density (ρ) of the optical glass of the present invention is 4.50 g / cm 3 or less, preferably 4.40 g / cm 3 or less, more preferably 4.30 g / cm 3 or less, more preferably 4.20 g / cm 3 The following is the result.

[0068] <Wear Level> Optical glass wear rate (F A ) is the value obtained by multiplying the ratio of the wear volume of the sample to the wear volume (volume) of a standard sample (H-K9 glass) under the exact same conditions by 100, and the calculation formula is as follows: F A =V / V0×100=(W / ρ) / (W0 / ρ0)×100 where: V is the volumetric wear volume of the sample being measured; V0 is the volumetric wear volume of the standard sample; W is the mass wear amount of the sample to be measured; W0 is the quality wear volume of the standard sample; ρ is the density of the sample being measured; ρ0 is the density of the standard sample.

[0069] In some embodiments, the abrasion rate (F A The upper limit of ) is 130, preferably 125, and more preferably 120. In some embodiments, the abrasion rate (F A The lower limit of ) is 90, preferably 95, and more preferably 100.

[0070] <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 560°C or less, preferably 550°C or less, more preferably 545°C or less, and even more preferably 540°C or less.

[0071] <Knoop hardness> Knoop hardness of optical glass (H K ) is tested in accordance with the test method specified in "GB / T 7962.18-2010." In the present invention, Knoop hardness may be abbreviated to hardness. In some embodiments, the Knoop hardness (H K ) is 600 x 10 7Pa or more, preferably 610 × 10 7 Pa or more, preferably 620×10 7 Pa or more.

[0072] [Manufacturing method] The method for producing 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, oxides, hydroxides, fluorides, and various salts (carbonates, nitrates, sulfates). Furnace materials prepared by conventional blending are placed in a melting furnace (e.g., a platinum, gold, or platinum alloy crucible) at 900 to 1400°C and melted. The resulting mixture is then clarified and homogenized to obtain a homogeneous molten glass free of bubbles and unmelted material. This molten glass is then cast into a mold and annealed. Those skilled in the art will be able to select the raw materials, manufacturing methods, and process parameters as appropriate for specific needs.

[0073] [Glass preforms and optical elements] Glass preforms can be manufactured from the prepared optical glass using press molding methods such as direct drop molding, polishing, or hot press molding. That is, molten optical glass can be manufactured into a precision glass preform by direct precision drop molding, or a glass preform can be manufactured by mechanical processing such as grinding or polishing, or a preform blank for press molding can be prepared using optical glass, and this preform blank can be hot pressed and polished to produce a glass preform. Note that the means for manufacturing optical preforms are not limited to the above means.

[0074] 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.

[0075] The optical preform and optical element of the present invention are both formed from the optical glass of the present invention. The optical preform of the present invention has the excellent properties of optical glass, and the optical element of the present invention has the excellent properties of optical glass, making it possible to provide optical elements such as various lenses and prisms with high optical value. Examples of lenses include various lenses 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, each having a spherical or aspherical lens surface.

[0076] [Optical equipment] Optical elements formed from the optical glass of the present invention can be used to manufacture optical equipment such as photographic devices, imaging devices, projection devices, display devices, in-vehicle devices, and monitoring devices. [Example]

[0077] <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 1 to 3. The properties of each glass were measured using the test methods described in the present invention, and the results are shown in Tables 1 to 3.

[0078] [Table 1]

[0079] [Table 2]

[0080] [Table 3]

[0081] <Example of glass preform> Using the glasses obtained in Examples 1 to 24 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 such as prisms, were manufactured by polishing or press molding such as reheat press molding and precision press molding.

[0082] <Optical element examples> The preforms obtained in the above optical preform examples were tempered, and the refractive index was finely adjusted while reducing strain inside the glass so that the optical properties such as the refractive index reached 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.

[0083] <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, or imaging equipment and devices in the automotive field by using one or more optical elements according to optical design to form optical parts or components.

Claims

1. An optical glass comprising the following components in weight percent: SiO 2 : 1 - 10%, B 2 O 3 : 18 - 31%, La 2 O 3 : 20 - 35%, ZnO: 19 - 32%, Gd 2 O 3 +Y 2 O 3 : 1 - 14%, and Nb 2 O 5 +WO 3 : 0.5 - 12%.

2. 2. The optical glass according to claim 1, further comprising one or more components selected from the following group in weight percent: ZrO 2 : 0-10%, Li 2 O: 0-8%, Na 2 O: 0-6%, K 2 O: 0-6%, RO: 0-4%, TiO 2 : 0 to 4%, Ta 2 O 5 : 0-4%, Al 2 O 3 : 0-4%, Yb 2 O 3 : 0-10%, F: 0-3%, and clarifier: 0-1%. The RO is one or more selected from the group consisting of MgO, CaO, SrO, and BaO, and the fining agent is Sb 2 O 3 , SnO, SnO 2 , and CeO 2 The compound is one or more selected from the group consisting of:

3. An optical glass containing the following components by weight: SiO 2 : 1 to 10%, B 2 O 3 : 18 to 31%, La 2 O 3 : 20 to 35%, ZrO 2 : 0 to 10%, ZnO: 19 to 32%, Gd 2 O 3 +Y 2 O 3 : 1 to 14%, Nb 2 O 5 +WO 3 : 0.5 to 12%, Li 2 O: 0 to 8%, Na 2 O: 0 to 6%, K 2 O: 0 to 6%, RO: 0 to 4%, TiO 2 : 0 to 4%, Ta 2 O 5 : 0 to 4%, Al 2 O 3 : 0 to 4%, Yb 2 O 3 : 0 to 10%, F: 0 to 3%, and fining agent: 0 to 1%. The RO is one or more selected from the group consisting of MgO, CaO, SrO, and BaO, and the fining agent is Sb 2 O 3 , SnO, SnO 2 , and CeO 2 The compound is one or more selected from the group consisting of:

4. 4. The optical glass according to claim 1, which satisfies one or more of the following ten conditions: 1) ZnO / La 2 O 3 (weight ratio) is 0.6 to 1.5; 2) (Gd 2 O 3 +Y 2 O 3 ) / ZnO (weight ratio) is 0.05 to 0.6; 3) (Nb 2 O 5 +WO 3 ) / SiO 2 (weight ratio) is 0.1 to 5.0; 4) SiO 2 / ZnO (weight ratio) is 0.05 to 0.45; 5) Nb 2 O 5 / Y 2 O 3 (weight ratio) is 0.1 to 5.0; 6) (WO 3 +Gd 2 O 3 +Ta 2 O 5 ) / ZnO (weight ratio) is 1.0 or less; 7) Gd 2 O 3 / WO 3 (weight ratio) is 6.5 or less; 8) (Nb 2 O 5 +WO 3 ) / ZnO (weight ratio) is 0.05 to 0.5; 9) (SiO 2 +WO 3 +La 2 O 3 ) / (ZnO+Gd 2 O 3 ) (weight ratio) is 0.6 to 2.0; 10) (B 2 O 3 +WO 3 ) / SiO 2 (weight ratio) is 2.5 to 15.

0.

5. 4. The optical glass according to claim 1, which satisfies one or more of the following ten conditions: 1) ZnO / La 2 O 3 (weight ratio) is 0.8 to 1.3; 2) (Gd 2 O 3 +Y 2 O 3 ) / ZnO (weight ratio) is 0.15 to 0.45; 3) (Nb 2 O 5 +WO 3 ) / SiO 2 (weight ratio) is 0.5 to 2.5; 4) SiO 2 / ZnO (weight ratio) is 0.1 to 0.4; 5) Nb 2 O 5 / Y 2 O 3 (weight ratio) is 0.3 to 2.5; 6) (WO 3 +Gd 2 O 3 +Ta 2 O 5 ) / ZnO (weight ratio) is 0.05 to 0.6; 7) Gd 2 O 3 / WO 3 (weight ratio) is 0.5 to 4.0; 8) (Nb 2 O 5 +WO 3 ) / ZnO (weight ratio) is 0.08 to 0.4; 9) (SiO 2 +WO 3 +La 2 O 3 ) / (ZnO+Gd 2 O 3 ) (weight ratio) is 0.8 to 1.5; 10) (B 2 O 3 +WO 3 ) / SiO 2 (weight ratio) is 3.5 to 8.

0.

6. 4. The optical glass according to claim 1, which satisfies one or more of the following ten conditions: 1) ZnO / La 2 O 3 (weight ratio) is 0.8 to 1.2; 2) (Gd 2 O 3 +Y 2 O 3 ) / ZnO (weight ratio) is 0.2 to 0.4; 3) (Nb 2 O 5 +WO 3 ) / SiO 2 (weight ratio) is 0.7 to 1.5; 4) SiO 2 / ZnO (weight ratio) is 0.15 to 0.35; 5) Nb 2 O 5 / Y 2 O 3 (weight ratio) is 0.5 to 1.5; 6) (WO 3 +Gd 2 O 3 +Ta 2 O 5 ) / ZnO (weight ratio) is 0.1 to 0.45; 7) Gd 2 O 3 / WO 3 (weight ratio) is 1.0 to 3.5; 8) (Nb 2 O 5 +WO 3 ) / ZnO (weight ratio) is 0.1 to 0.3; 9) (SiO 2 +WO 3 +La 2 O 3 ) / (ZnO+Gd 2 O 3 ) (weight ratio) is 0.8 to 1.3; 10) (B 2 O 3 +WO 3 ) / SiO 2 (weight ratio) is 4.0 to 6.

0.

7. 4. The optical glass according to claim 1, comprising one or more components selected from the following group in weight percent: SiO 2 : 2-8%, B 2 O 3 : 20-29%, La 2 O 3 : 22-33%, ZrO 2 : 1~8%, ZnO: 20~28%, Gd 2 O 3 +Y 2 O 3 : 2-12%, Nb 2 O 5 +WO 3 : 1-10%, Li 2 O: 0.5-7%, Na 2 O: 0-3%, K 2 O: 0-3%, RO: 0-1%, TiO 2 : 0 to 2%, Ta 2 O 5 : 0-1%, Al 2 O 3 : 0 to 1%, Yb 2 O 3 : 0-2%, F: 0-1%, and clarifier: 0-0.5%. The RO is one or more selected from the group consisting of MgO, CaO, SrO, and BaO, and the fining agent is Sb 2 O 3 , SnO, SnO 2 , and CeO 2 The compound is one or more selected from the group consisting of:

8. SiO % by weight 2 : 3-7%, B 2 O 3 : 22-27%, La 2 O 3 : 24-31%, ZrO 2 : 1.5~5.5%, ZnO: 22~27%, Gd 2 O 3 +Y 2 O 3 : 2.5-10%, Nb 2 O 5 +WO 3 : 2-8%, Li 2 O: 1 to 5%, and clarifier: 0 to 0.2%, and / or Na 2 OK 2 O, RO, TiO 2 , Ta 2 O 5 , Al 2 O 3 , Yb 2 O 3 4. The optical glass according to claim 1, which does not contain one or more components selected from the group consisting of: The RO is one or more selected from the group consisting of MgO, CaO, SrO, and BaO, and the fining agent is Sb 2 O 3 , SnO, SnO 2 , and CeO 2 The compound is one or more selected from the group consisting of:

9. 4. The optical glass according to claim 1, comprising one or more components selected from the following group in weight percent: Gd 2 O 3 : 0-10%, Y 2 O 3 : 0-10%, Nb 2 O 5 : 0-10%, and WO 3 : A group consisting of 0-8%.

10. 4. The optical glass according to claim 1, comprising one or more components selected from the following group in weight percent: Gd 2 O 3 : 2-7%, Y 2 O 3 : 1-5%, Nb 2 O 5 : 1-6%, and WO 3 : A group consisting of 1-3.8%.

11. 4. The optical glass according to claim 1, which satisfies one or more of the following 12 conditions: 1) Refractive index n d is 1.71 to 1.79, 2) Abbe number v d 42 to 49, 3) λ 80 is 400nm or less, 4) λ 5 is 350 nm or less, 5) Water resistance stability D W Class 2 or higher, 6) The upper limit of crystal precipitation temperature is 1080°C or less. 7) Young's modulus E is 10000 x 10 7 / Pa or more, 8) Coefficient of thermal expansion α -30 / 70℃ が80×10 -7 / K or below 9) Density ρが4.50g / cm 3 the following, 10) Wear level F A is 90 to 130, 11) Transition temperature T g is 560℃ or less, 12) Knoop hardness H K is 600 x 10 7 More than Pa.

12. 4. The optical glass according to claim 1, which satisfies one or more of the following 12 conditions: 1) Refractive index n d is 1.73 to 1.77, 2) Abbe number v d 44 to 47, 3) λ 80 is 380nm or less, 4) λ 5 is 330 nm or less, 5) Water resistance stability D W is Class 1, 6) The upper limit of crystal precipitation temperature is 980°C or less. 7) Young's modulus E is 11000 x 10 7 / Pa~12000×10 7 / Pa, 8) Coefficient of thermal expansion α -30 / 70℃ が65×10 -7 / K or below 9) Density ρが4.20g / cm 3 the following, 10) Wear level F A is 100 to 120, 11) Transition temperature T g is 540℃ or less, 12) Knoop hardness H K is 620 x 10 7 More than Pa.

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.

Images