Optical glass, glass preform, optical element and optical instrument

Abstract

The invention provides optical glass which comprises the following components in percentage by weight: 4-11% of SiO2; 8 to 15 percent of B2O3; la2O3: greater than 45% but less than or equal to 55%; 2 to 9.5 percent of Gd2O3; 4 to 10 percent of Y2O3; zrO2: 3 to 10 percent; 5 to 12 percent of Nb2O5; 0.1 to 5 percent of TiO2; al2O3: greater than 0 but less than or equal to 4%. Through reasonable component design, the optical glass with expected refractive index and Abbe number can be obtained with lower raw material cost.

Description

TECHNICAL FIELD

[0001] The present application relates to an optical glass, in particular to an optical glass with a refractive index of 1.86-1.91 and an Abbe number of 37-41, and a glass preform, an optical element and an optical instrument made of the same. BACKGROUND

[0002] In the design of optical systems, high refractive index optical glass is usually used to achieve miniaturization, ultra-thin and wide-angle, which is easier to correct chromatic aberration while achieving light weight and high performance of optical systems, therefore, the market demand for optical glass with a refractive index of 1.86-1.91 and an Abbe number of 37-41 continues to increase. In the prior art, the components of optical glass with a refractive index of 1.86-1.91 and an Abbe number of 37-41 generally contain a large amount of Ta2O5 to achieve a higher refractive index. For example, Chinese patent application CN101792257A discloses an optical glass with a refractive index greater than 1.85 and an Abbe number of 36 or more, which contains more than 10wt% of Ta2O5. Chinese patent application CN101549954A discloses a high refractive index low dispersion optical glass with a refractive index of 1.85-1.91 and an Abbe number of 38-42, which contains 10-25wt% of Ta2O5. Ta2O5 is a scarce and expensive component, and the use of high content of Ta2O5 is extremely detrimental to the control of the cost of optical glass products, therefore, reducing or not using Ta2O5 in optical glass is the goal of optical glass research and development. SUMMARY

[0003] The technical problem to be solved by the present application is to provide an optical glass with a lower raw material cost, a refractive index of 1.86-1.91 and an Abbe number of 37-41.

[0004] The technical solution adopted by the present application to solve the technical problem is:

[0005] The optical glass contains, in terms of weight percentage, SiO2: 4-11%; B2O3: 8-15%; La2O3: more than 45% but less than or equal to 55%; Gd2O3: 2-9.5%; Y2O3: 4-10%; ZrO2: 3-10%; Nb2O5: 5-12%; TiO2: 0.1-5%; Al2O3: more than 0 but less than or equal to 4%.

[0006] Further, the optical glass, the components of which are represented by weight percentage, further comprises: ZnO: 0-4%; and / or RO: 0-5%; and / or Rn2O: 0-5%; and / or WO3: 0-5%; and / or Ta2O5: 0-5%; and / or Yb2O3: 0-5%; and / or GeO2: 0-4%; and / or fining agent: 0-1%, the RO is one or more of MgO, CaO, SrO, BaO, the Rn2O is one or more of Li2O, Na2O, K2O, and the fining agent is one or more of Sb2O3, SnO2, CeO2.

[0007] The optical glass, the components of which are represented by weight percentage, is composed of SiO2: 4-11%; B2O3: 8-15%; La2O3: more than 45% but less than or equal to 55%; Gd2O3: 2-9.5%; Y2O3: 4-10%; ZrO2: 3-10%; Nb2O5: 5-12%; TiO2: 0.1-5%; Al2O3: more than 0 but less than or equal to 4%; ZnO: 0-4%; RO: 0-5%; Rn2O: 0-5%; WO3: 0-5%; Ta2O5: 0-5%; Yb2O3: 0-5%; GeO2: 0-4%; fining agent: 0-1%, the RO is one or more of MgO, CaO, SrO, BaO, the Rn2O is one or more of Li2O, Na2O, K2O, and the fining agent is one or more of Sb2O3, SnO2, CeO2.

[0008] Further, the optical glass, the components of which are represented by weight percentage, wherein: Gd2O3 / Y2O3 is 0.25-1.1, preferably Gd2O3 / Y2O3 is 0.3-1.0, more preferably Gd2O3 / Y2O3 is 0.4-0.9, and further preferably Gd2O3 / Y2O3 is 0.5-0.9.

[0009] Further, the optical glass, the components of which are represented by weight percentage, wherein: Gd2O3 / SiO2 is 0.2-1.0, preferably Gd2O3 / SiO2 is 0.3-0.95, more preferably Gd2O3 / SiO2 is 0.4-0.9, and further preferably Gd2O3 / SiO2 is 0.5-0.9.

[0010] Further, the optical glass, the components of which are represented by weight percentage, wherein: Al2O3 / TiO2 is 0.05-3.0, preferably Al2O3 / TiO2 is 0.1-2.0, more preferably Al2O3 / TiO2 is 0.1-1.5, and further preferably Al2O3 / TiO2 is 0.2-1.0.

[0011] Further, the optical glass, the components of which are represented by weight percentage, wherein: Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is 0.9-4.0, preferably Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is 1.0-3.5, more preferably Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is 1.0-3.0, further preferably Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is 1.2-2.0.

[0012] Further, the optical glass, the components of which are represented by weight percentage, wherein: (La2O3+Y2O3) / (Nb2O5+ZrO2) is 2.5-6.5, preferably (La2O3+Y2O3) / (Nb2O5+ZrO2) is 2.8-6.0, more preferably (La2O3+Y2O3) / (Nb2O5+ZrO2) is 3.0-5.5, further preferably (La2O3+Y2O3) / (Nb2O5+ZrO2) is 3.5-5.0.

[0013] Further, the optical glass, the components of which are represented by weight percentage, wherein: (TiO2+ZnO+Ta2O5+WO3) / Nb2O5 is 0.01-1.0, preferably (TiO2+ZnO+Ta2O5+WO3) / Nb2O5 is 0.05-0.8, more preferably (TiO2+ZnO+Ta2O5+WO3) / Nb2O5 is 0.1-0.5, further preferably (TiO2+ZnO+Ta2O5+WO3) / Nb2O5 is 0.1-0.3.

[0014] Further, the optical glass, the components of which are represented by weight percentage, wherein: Al2O3 / Gd2O3 is 0.02-0.8, preferably Al2O3 / Gd2O3 is 0.05-0.6, more preferably Al2O3 / Gd2O3 is 0.1-0.5, further preferably Al2O3 / Gd2O3 is 0.1-0.4.

[0015] Further, the optical glass, the components of which are represented by weight percentage, wherein: (La2O3+Nb2O5) / Gd2O3 is 6.0-23.0, preferably (La2O3+Nb2O5) / Gd2O3 is 8.0-20.0, more preferably (La2O3+Nb2O5) / Gd2O3 is 9.0-15.0, further preferably (La2O3+Nb2O5) / Gd2O3 is 10.0-13.0.

[0016] Further, the optical glass, wherein the components are represented by weight percentage, wherein: Nb2O5 / Y2O3 is 0.6 to 2.0, preferably Nb2O5 / Y2O3 is 0.7 to 1.7, more preferably Nb2O5 / Y2O3 is 0.8 to 1.5, further preferably Nb2O5 / Y2O3 is 0.9 to 1.2.

[0017] Further, the optical glass, wherein the components are represented by weight percentage, wherein: (Ta2O5+ZnO+RO) / TiO2 is 2.5 or less, preferably (Ta2O5+ZnO+RO) / TiO2 is 1.5 or less, more preferably (Ta2O5+ZnO+RO) / TiO2 is 1.0 or less, further preferably (Ta2O5+ZnO+RO) / TiO2 is 0.5 or less, and the RO is one or more of MgO, CaO, SrO, BaO.

[0018] Further, the optical glass, wherein the components are represented by weight percentage, wherein: Al2O3 / SiO2 is 0.01 to 0.8, preferably Al2O3 / SiO2 is 0.05 to 0.6, more preferably Al2O3 / SiO2 is 0.08 to 0.5, further preferably Al2O3 / SiO2 is 0.1 to 0.3.

[0019] Further, the optical glass, wherein the components are represented by weight percentage, wherein: SiO2: 5-10%, preferably SiO2: 5.5-9%; and / or B2O3: 10-14%, preferably B2O3: 11-13.5%; and / or La2O3: 46-53%, preferably La2O3: 48-52%; and / or Gd2O3: 3-8%, preferably Gd2O3: 4-7%; and / or Y2O3: 5-9.5%, preferably Y2O3: 5.5-8.5%; and / or ZrO2: 4-9%, preferably ZrO2: 5-8%; and / or Nb2O5: 5.5-11%, preferably Nb2O5: 6-10%; and / or TiO2: 0.5-4%, preferably TiO2: 1-3%; and / or Al2O3: 0.1-3%, preferably Al2O3: 0.5-2%; and / or ZnO: 0-2%, preferably ZnO: 0-1%; and / or RO: 0-3%, preferably RO: 0-1%; and / or Rn2O: 0-3%, preferably Rn2O: 0-1%; and / or WO3: 0-3%, preferably WO3: 0-1%; and / or Ta2O5: 0-3%, preferably Ta2O5: 0-1%; and / or Yb2O3: 0-3%, preferably Yb2O3: 0-1%; and / or GeO2: 0-2%, preferably GeO2: 0-1%; and / or fining agent: 0-0.5%, preferably fining agent: 0-0.1%, the RO is one or more of MgO, CaO, SrO, BaO, Rn2O is one or more of Li2O, Na2O, K2O, and the fining agent is one or more of Sb2O3, SnO2, CeO2.

[0020] Further, the optical glass, wherein the components do not contain ZnO; and / or do not contain MgO; and / or do not contain CaO; and / or do not contain SrO; and / or do not contain BaO; and / or do not contain Li2O; and / or do not contain Na2O; and / or do not contain K2O; and / or do not contain WO3; and / or do not contain Ta2O5; and / or do not contain Yb2O3; and / or do not contain GeO2; and / or do not contain Sb2O3; and / or do not contain SnO2; and / or do not contain CeO2.

[0021] Further, the optical glass has a refractive index n d of 1.86-1.91, preferably 1.87-1.90, more preferably 1.875-1.89, and an Abbe number v d of 37-41, preferably 38-40.5, more preferably 38.5-40.

[0022] Further, the optical glass has a thermal expansion coefficient a -30 / 70℃ of 85x10 -7 / K or less, preferably 80x10-7 75 x 10 -7 < 1.5 x 10 W 2 or more, preferably 1; and / or acid resistance stability D A 2 or more, preferably 1; and / or hardness H K 680 x 10 7 690 x 10 7 700 x 10 7 720 x 10 g,F 0.7000 or less, preferably 0.6500 or less, more preferably 0.6000 or less; and / or relative partial dispersion deviation ΔP g,F -0.0020 or less, preferably -0.0040 or less, more preferably -0.0050 or less, further preferably -0.0058 or less; and / or bubble degree is A class or more, preferably A0 class or more, more preferably A 00 C class or more, preferably B class or more; and / or density ρ is 5.10 g / cm 3 5.00 g / cm 3 4.95 g / cm 3 4.90 g / cm; and / or anti-crystallization property is C class or more, preferably B class or more, more preferably A class.

[0023] A glass preform is made of the optical glass described above.

[0024] An optical element is made of the optical glass described above, or made of the glass preform described above.

[0025] An optical instrument contains the optical glass described above, and / or contains the optical element described above.

[0026] The present application has the following advantageous effects: by rational component design, the present application can obtain an optical glass having desired refractive index and Abbe number at a lower raw material cost. DETAILED DESCRIPTION

[0027] Hereinafter, the embodiments of the optical glass of the present application will be described in detail, but the present application is not limited to the following embodiments, and can be implemented by appropriately changing within the scope of the object of the present application. Furthermore, regarding the repeatedly described parts, although there are appropriately omitted descriptions, the gist of the present application is not limited thereto, and in the following content, the optical glass of the present application is sometimes referred to as glass.

[0028] [Optical Glass]

[0029] The ranges of the components of the optical glass of the present application are described below. In the present application, the content of each component, the total content is expressed in terms of weight percent (wt%) unless otherwise specified, i.e., the content of each component, the total content is expressed in terms of weight percent with respect to the total amount of glass material converted into an oxide composition. Here, the "converted into an oxide composition" refers to the case where the oxide, the complex salt, and the hydroxide, etc. used as raw materials for the optical glass composition of the present application are decomposed and converted into an oxide when melted.

[0030] Unless otherwise indicated in a specific case, the numerical ranges set forth in the present application include the upper and lower limits, "above" and "below" include the end point values, and all integers and fractions within the range, and are not limited to the specific values listed in the defined range. As used herein, "and / or" is inclusive, e.g., "A and / or B" means only A, or only B, or both A and B.

[0031] <Necessary components and optional components>

[0032] SiO2can increase the viscosity of the molten glass, reduce the coloring of the glass, improve the thermal stability of the glass, and improve the resistance to devitrification, but if the content is too high, the melting of the glass becomes difficult, the transition temperature increases, and the refractive index is difficult to meet the design requirements. Therefore, the content of SiO2in the present application is 4-11%, preferably 5-10%, and more preferably 5.5-9%. In some embodiments, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11% of SiO2may be included.

[0033] B2O3is a glass network forming component, which can improve the melting property and resistance to devitrification of the glass, and is also an effective component for imparting low dispersion to the glass. If the content of B2O3is less than 8%, the stability of the glass decreases. If the content of B2O3is too high, the chemical stability of the glass decreases, and the refractive index of the glass is difficult to meet the design requirements. Therefore, the content of B2O3in the present application is 8-15%, preferably 10-14%, and more preferably 11-13.5%. In some embodiments, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15% of B2O3may be included.

[0034] La2O3 is a high-refractive low-dispersive component, which can increase the refractive index and adjust the dispersion of the glass, and reduce the high-temperature viscosity of the glass. If the content of La2O3 is too high, the resistance to devitrification of the glass is reduced, and the refractive index temperature coefficient and Abbe number are difficult to meet the design requirements. Therefore, the content of La2O3 in the present application is greater than 45% but less than or equal to 55%, preferably 46-53%, more preferably 48-52%. In some embodiments, it can contain more than 45%, 45.1%, 45.5%, 46%, 46.5%, 47%, 47.5%, 48%, 48.5%, 49%, 49.5%, 50%, 50.5%, 51%, 51.5%, 52%, 52.5%, 53%, 53.5%, 54%, 54.5%, 55% of La2O3.

[0035] Gd2O3 is a high-refractive low-dispersive component, which can reduce the relative partial dispersion of the glass and improve the chemical stability in the glass. If the content of Gd2O3 is too high, the resistance to devitrification of the glass is poor, and the transition temperature is increased. Therefore, the content of Gd2O3 in the present application is 2-9.5%, preferably 3-8%, more preferably 4-7%. In some embodiments, it can contain 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5% of Gd2O3.

[0036] In some embodiments, the ratio between the content of Gd2O3 and the content of SiO2, Gd2O3 / SiO2, is controlled in the range of 0.2-1.0, which can make the optical glass have excellent chemical stability while improving the hardness and bubble degree of the glass, and prevent the thermal expansion coefficient from increasing. Therefore, Gd2O3 / SiO2 is preferably 0.2-1.0, more preferably Gd2O3 / SiO2 is 0.3-0.95, further preferably Gd2O3 / SiO2 is 0.4-0.9, and more further preferably Gd2O3 / SiO2 is 0.5-0.9. In some embodiments, the value of Gd2O3 / SiO2 can be 0.2, 0.23, 0.25, 0.27, 0.3, 0.33, 0.35, 0.37, 0.4, 0.43, 0.45, 0.47, 0.5, 0.53, 0.55, 0.57, 0.6, 0.63, 0.65, 0.67, 0.7, 0.73, 0.75, 0.77, 0.8, 0.83, 0.85, 0.87, 0.9, 0.93, 0.95, 0.97, 1.0.

[0037] In the present application, by containing 4% or more Y2O3, by containing Y2O3 and Gd2O3 together, the melting property and the anti-crystallization property of the glass are improved while maintaining high refractive index and low dispersion. If the content of Y2O3 is too high, the stability and the resistance to devitrification of the glass decrease, and the transition temperature increases. Therefore, the content of Y2O3 is 4% to 10%, preferably 5% to 9.5%, more preferably 5.5% to 8.5%. In some embodiments, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10% of Y2O3 can be included.

[0038] In some embodiments, the ratio between the content of Gd2O3 and the content of Y2O3, Gd2O3 / Y2O3, is controlled in the range of 0.25 to 1.1, which can reduce the thermal expansion coefficient of the glass and improve the chemical stability of the glass. Therefore, Gd2O3 / Y2O3 is preferably 0.25 to 1.1, more preferably Gd2O3 / Y2O3 is 0.3 to 1.0. Further, controlling Gd2O3 / Y2O3 in the range of 0.4 to 0.9 can further improve the anti-crystallization property of the glass. Therefore, Gd2O3 / Y2O3 is further preferably 0.4 to 0.9, more further preferably Gd2O3 / Y2O3 is 0.5 to 0.9. In some embodiments, the value of Gd2O3 / Y2O3 can be 0.25, 0.27, 0.3, 0.33, 0.35, 0.37, 0.4, 0.43, 0.45, 0.47, 0.5, 0.53, 0.55, 0.57, 0.6, 0.63, 0.65, 0.67, 0.7, 0.73, 0.75, 0.77, 0.8, 0.83, 0.85, 0.87, 0.9, 0.93, 0.95, 0.97, 1.0, 1.03, 1.05, 1.07, 1.1.

[0039] Yb2O3 is a high-refractive low-dispersion component, and if its content exceeds 5%, the anti-crystallization property of the glass decreases. Therefore, the content of Yb2O3 is 0 to 5%, preferably 0 to 3%, more preferably 0 to 1%, further preferably Yb2O3 is not contained. In some embodiments, 0%, more than 0%, 0.01%, 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of Yb2O3 can be included.

[0040] ZrO2 can improve the refractive index and the resistance to devitrification of the glass, and reduce the ΔP of the glass g,FThe content of ZrO2 is 3-10%, preferably 4-9%, and more preferably 5-8%. In some embodiments, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10% of ZrO2 can be included.

[0041] Nb2O5 has the effects of increasing the refractive index, improving the chemical stability and resistance to devitrification, and can reduce the thermal expansion coefficient of the glass without significantly increasing the P g,F value and ΔP g,F value, and if the content of Nb2O5 is less than 5%, the above effects are not obvious. If the content of Nb2O5 exceeds 12%, the weather resistance and light transmittance of the glass decrease, and the transition temperature of the glass increases. Therefore, the content of Nb2O5 is 5-12%, preferably 5.5-11%, and more preferably 6-10%. In some embodiments, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, or 12% of Nb2O5 can be included.

[0042] In some embodiments, the ratio between the total content of La2O3 and Y2O3 (La2O3+Y2O3) and the total content of Nb2O5 and ZrO2 (Nb2O5+ZrO2) (La2O3+Y2O3) / (Nb2O5+ZrO2) is controlled in the range of 2.5-6.5, so that the optical glass can more easily obtain the desired refractive index and Abbe number, and the P g,F value and ΔP g,Fvalues. Thus, it is preferred that (La2O3+ Y2O3) / (Nb2O5+ ZrO2) be in the range of 2.5 to 6.5, more preferably (La2O3+ Y2O3) / (Nb2O5+ ZrO2) be in the range of 2.8 to 6.0. Further, controlling (La2O3+ Y2O3) / (Nb2O5+ ZrO2) in the range of 3.0 to 5.5 can further improve the hardness of the glass. Thus, it is further preferred that (La2O3+ Y2O3) / (Nb2O5+ ZrO2) be in the range of 3.0 to 5.5, and more further preferred that (La2O3+ Y2O3) / (Nb2O5+ ZrO2) be in the range of 3.5 to 5.0. In some embodiments, (La2O3+ Y2O3) / (Nb2O5+ ZrO2) can have a value of 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5.

[0043] In some embodiments, controlling the ratio (La2O3+ Nb2O5) / Gd2O3 between the combined content of La2O3and Nb2O5and the content of Gd2O3in the range of 6.0 to 23.0 can reduce the density, the P g,F values and ΔP g,F values, and improve the chemical durability and the bubble level of the glass. Thus, it is preferred that (La2O3+ Nb2O5) / Gd2O3 be in the range of 6.0 to 23.0, more preferably (La2O3+ Nb2O5) / Gd2O3 be in the range of 8.0 to 20.0, further preferably (La2O3+ Nb2O5) / Gd2O3 be in the range of 9.0 to 15.0, and more further preferably (La2O3+ Nb2O5) / Gd2O3 be in the range of 10.0 to 13.0. In some embodiments, (La2O3+ Nb2O5) / Gd2O3 can have a value of 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0, 18.5, 19.0, 19.5, 20.0, 20.5, 21.0, 21.5, 22.0, 22.5, 23.0.

[0044] In some embodiments, the ratio of the content of Nb2O5to the content of Y2O3, Nb2O5 / Y2O3, is controlled in the range of 0.6 to 2.0, which can increase the bubble degree of the optical glass while having the desired refractive index and Abbe number, and prevent the decrease of weather resistance and resistance to devitrification. Therefore, it is preferable that Nb2O5 / Y2O3be 0.6 to 2.0, more preferable that Nb2O5 / Y2O3be 0.7 to 1.7, further preferable that Nb2O5 / Y2O3be 0.8 to 1.5, and more further preferable that Nb2O5 / Y2O3be 0.9 to 1.2. In some embodiments, the value of Nb2O5 / Y2O3may be 0.6, 0.63, 0.65, 0.67, 0.7, 0.73, 0.75, 0.77, 0.8, 0.83, 0.85, 0.87, 0.9, 0.93, 0.95, 0.97, 1.0, 1.03, 1.05, 1.07, 1.1, 1.13, 1.15, 1.17, 1.2, 1.23, 1.25, 1.27, 1.3, 1.33, 1.35, 1.37, 1.4, 1.43, 1.45, 1.47, 1.5, 1.53, 1.55, 1.57, 1.6, 1.63, 1.65, 1.67, 1.7, 1.73, 1.75, 1.77, 1.8, 1.83, 1.85, 1.87, 1.9, 1.93, 1.95, 1.97, 2.0.

[0045] Al2O3may decrease the thermal expansion coefficient of the glass, and increase the crystallization resistance and thermal stability of the glass. However, if the content of Al2O3is too high, the glass transition temperature will increase, and the melting property of the glass will deteriorate. Therefore, the content of Al2O3in the present application is greater than 0 but less than or equal to 4%, preferably 0.1 to 3%, and more preferably 0.5 to 2%. In some embodiments, Al2O3may be included in an amount greater than 0%, 0.01%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%.

[0046] In some embodiments, the ratio of the content of Al2O3 to the content of SiO2, Al2O3 / SiO2, is controlled in the range of 0.01 to 0.8, which can improve the anti-crystallization performance and striation degree of the glass and optimize the polishing degree of the glass. Therefore, it is preferred that Al2O3 / SiO2 is 0.01 to 0.8, more preferably Al2O3 / SiO2 is 0.05 to 0.6, further preferably Al2O3 / SiO2 is 0.08 to 0.5, and more further preferably Al2O3 / SiO2 is 0.1 to 0.3. In some embodiments, the value of Al2O3 / SiO2 can be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.13, 0.15, 0.17, 0.2, 0.23, 0.25, 0.27, 0.3, 0.33, 0.35, 0.37, 0.4, 0.43, 0.45, 0.47, 0.5, 0.53, 0.55, 0.57, 0.6, 0.63, 0.65, 0.67, 0.7, 0.73, 0.75, 0.77, 0.8.

[0047] In some embodiments, the ratio of the content of Al2O3 to the content of Gd2O3, Al2O3 / Gd2O3, is controlled in the range of 0.02 to 0.8, which can improve the striation degree and hardness of the glass and optimize the anti-crystallization performance of the glass. Therefore, it is preferred that Al2O3 / Gd2O3 is 0.02 to 0.8, more preferably Al2O3 / Gd2O3 is 0.05 to 0.6, further preferably Al2O3 / Gd2O3 is 0.1 to 0.5, and more further preferably Al2O3 / Gd2O3 is 0.1 to 0.4. In some embodiments, the value of Al2O3 / Gd2O3 can be 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.13, 0.15, 0.17, 0.2, 0.23, 0.25, 0.27, 0.3, 0.33, 0.35, 0.37, 0.4, 0.43, 0.45, 0.47, 0.5, 0.53, 0.55, 0.57, 0.6, 0.63, 0.65, 0.67, 0.7, 0.73, 0.75, 0.77, 0.8.

[0048] TiO2 has the effect of increasing the refractive index and dispersion of the glass, and an appropriate amount of TiO2 in the present application can increase the stability of the glass and improve the anti-crystallization performance of the glass, but if its content exceeds 5%, the P g,F value and ΔP g,FThe value of TiO2is increased, and the glass is easy to crystallize during the process of pressing. Therefore, the content of TiO2in the present application is 0.1-5%, preferably 0.5-4%, more preferably 1-3%. In some embodiments, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of TiO2may be contained.

[0049] In some embodiments, the ratio of the content of Al2O3to the content of TiO2, Al2O3 / TiO2, is controlled to be in the range of 0.05-3.0, which can improve the anti-crystallization performance and hardness of the glass, and optimize the striation degree of the glass. Therefore, the Al2O3 / TiO2is preferably 0.05-3.0, more preferably 0.1-2.0, further preferably 0.1-1.5, and more further preferably 0.2-1.0. In some embodiments, the value of Al2O3 / TiO2may be 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0.

[0050] ZnO is an optional component in the present application, which can improve the chemical stability of the glass, enhance the weather resistance of the glass, and reduce the transition temperature of the glass. However, when the content of ZnO is too high, it will increase the erosion of platinum gold wares during the melting process, reduce the service life of the furnace, and is not conducive to the anti-crystallization of the glass. Therefore, the content of ZnO in the present application is 0-4%, preferably 0-2%, more preferably 0-1%, and further preferably no ZnO is contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4% of ZnO may be contained.

[0051] WO3 can improve the refractive index and mechanical strength of the glass. If the content of WO3 exceeds 5%, the thermal stability of the glass decreases and the resistance to devitrification decreases. Therefore, the content of WO3 in the present application is 0-5%, preferably 0-3%, and more preferably 0-1%. In some embodiments, it is further preferred that no WO3 is contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of WO3 can be contained.

[0052] Ta2O5 has the effect of improving the refractive index and improving the resistance to devitrification of the glass. However, if the content of Ta2O5 is too high, the thermal stability of the glass decreases, the density increases, and the cost control of the raw materials of the glass is not favorable. Therefore, the content of Ta2O5 in the present application is 0-5%, preferably 0-3%, and more preferably 0-1%. In some embodiments, it is further preferred that no Ta2O5 is contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of Ta2O5 can be contained.

[0053] In some embodiments, the ratio between the total content of TiO2, ZnO, Ta2O5, and WO3 and the content of Nb2O5, (TiO2+ZnO+Ta2O5+WO3) / Nb2O5, is controlled to be in the range of 0.01-1.0, which can reduce the coefficient of thermal expansion of the glass, improve the bubble degree of the glass, prevent the P g,F the value of ΔP g,FThe value of (TiO2+ZnO+Ta2O5+WO3) / Nb2O5is preferably 0.01 to 1.0, more preferably 0.05 to 0.8, further preferably 0.1 to 0.5, and still further preferably 0.1 to 0.3. In some embodiments, the value of (TiO2+ZnO+Ta2O5+WO3) / Nb2O5may be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.13, 0.15, 0.17, 0.2, 0.23, 0.25, 0.27, 0.3, 0.33, 0.35, 0.37, 0.4, 0.43, 0.45, 0.47, 0.5, 0.53, 0.55, 0.57, 0.6, 0.63, 0.65, 0.67, 0.7, 0.73, 0.75, 0.77, 0.8, 0.83, 0.85, 0.87, 0.9, 0.93, 0.95, 0.97, 1.0.

[0054] GeO2increases the refractive index and resistance to devitrification of the glass, but if its content is too high, the chemical stability of the glass decreases; on the other hand, GeO2is very expensive compared to other components, and from the point of view of the cost of the raw materials for the glass, its use should be minimized. Therefore, the content of GeO2in the present application is limited to 0 to 4%, preferably 0 to 2%, more preferably 0 to 1%, and still further preferably the glass does not contain GeO2. In some embodiments, the glass can contain 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4% of GeO2.

[0055] In some embodiments, controlling the ratio between the content of Y2O3 and the total content of Gd2O3, Ta2O5, ZnO, WO3, GeO2, Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is in the range of 0.9-4.0, the bubble degree and the striation degree of the glass can be increased, and the density of the glass can be decreased. Therefore, it is preferred that Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is in the range of 0.9-4.0, more preferably Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is in the range of 1.0-3.5, further preferably Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is in the range of 1.0-3.0, and more further preferably Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is in the range of 1.2-2.0. In some embodiments, the value of Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) can be 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2.0, 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35, 2.4, 2.45, 2.5, 2.55, 2.6, 2.65, 2.7, 2.75, 2.8, 2.85, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0.

[0056] RO (RO is one or more of MgO, CaO, SrO and BaO) can improve the melting property of the glass, adjust the optical constant of the glass, and if its content exceeds 5%, the glass resistance to devitrification decreases. Therefore, the content of RO in the present application is 0-5%, preferably 0-3%, more preferably 0-1%. In some embodiments, it is further preferred to not contain MgO, and / or not contain CaO, and / or not contain SrO, and / or not contain BaO. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of RO can be contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of MgO can be contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of CaO can be contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of SrO can be contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of BaO can be contained.

[0057] In some embodiments, the ratio between the total content of Ta2O5, ZnO, RO, Ta2O5+ZnO+RO, and the content of TiO2, (Ta2O5+ZnO+RO) / TiO2, is controlled to be below 2.5, which can optimize the striation of the glass while reducing the coefficient of thermal expansion and the density of the glass. Thus, it is preferred that (Ta2O5+ZnO+RO) / TiO2be below 2.5, more preferred that (Ta2O5+ZnO+RO) / TiO2be below 1.5, further preferred that (Ta2O5+ZnO+RO) / TiO2be below 1.0, still further preferred that (Ta2O5+ZnO+RO) / TiO2be below 0.5. In some embodiments, the value of (Ta2O5+ZnO+RO) / TiO2may be 0, greater than 0, 0.01, 0.03, 0.05, 0.07, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2.0, 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35, 2.4, 2.45, 2.5.

[0058] Rn20 (Rn20 is one or more of Li20, Na20, K20) can reduce the transition temperature of the glass, adjust the optical constants and high temperature viscosity of the glass, and improve the melting property of the glass, but if its content is too high, the devitrification resistance and chemical stability of the glass will decrease. Therefore, the content of Rn20 in the present application is 0-5%, preferably 0-3%, more preferably 0-1%. In some embodiments, it is further preferred to not contain Li20, and / or not contain Na20, and / or not contain K20. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of Rn20 can be contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of Li20 can be contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of Na20 can be contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of K20 can be contained.

[0059] In the present application, by containing 0-1% of one or more components of Sb2O3, SnO2, CeO2 as fining agent, the fining effect of the glass can be improved, and the bubble degree of the glass is improved. Preferably, the content of the fining agent is 0-0.5%, more preferably the content of the fining agent is 0-0.1%. Since the component types and content of the optical glass of the present application are designed reasonably, the bubble degree is excellent, and therefore in some embodiments, it is further preferred to not contain the fining agent. When the content of Sb2O3 exceeds 1%, the glass has a tendency to reduce the fining performance, and at the same time, due to its strong oxidation effect, it promotes the corrosion of platinum or platinum alloy vessels for melting the glass and the deterioration of the forming mold, and therefore the content of Sb2O3 in the present application is preferably 0-1%, more preferably 0-0.5%, further preferably 0-0.1%, and more preferably does not contain Sb2O3. SnO2 can also be used as a fining agent, but when its content exceeds 1%, the glass has a tendency to increase coloration, or when the glass is heated, softened and molded or reformed, Sn becomes the starting point for the generation of crystal nuclei, and has a tendency to devitrify. Therefore, the content of SnO2 in the present application is preferably 0-1%, more preferably 0-0.5%, further preferably 0-0.1%, and more preferably does not contain SnO2. The role and content of CeO2 are the same as those of SnO2, and the content is preferably 0-1%, more preferably 0-0.5%, further preferably 0-0.1%, and more preferably does not contain CeO2. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1% of the fining agent can be contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1% of Sb2O3 can be contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1% of SnO2 can be contained. In some embodiments, 0%, more than 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1% of CeO2 can be contained.

[0060] <Components not to be contained>

[0061] In the glass of the present application, even if the oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo are contained in a small amount, alone or in combination, the glass will be colored, and absorption will occur at specific wavelengths in the visible region, thereby reducing the property of the present application to improve the visible light transmittance, and thus, for optical glasses for which the transmittance at the wavelengths in the visible region is required, it is preferable that they are not actually contained.

[0062] The oxides of Th, Cd, Tl, Os, Be, and Se have a tendency to be controlled in use as harmful chemical substances in recent years, and measures for environmental protection are necessary not only in the manufacturing process of the glass, but also in the processing process and disposal after productization. Thus, in the case where the influence on the environment is valued, it is preferable that they are not actually contained except for inevitable mixing. Thus, the optical glass becomes practically free from substances that pollute the environment. Therefore, even if no special measures for environmental countermeasures are taken, the optical glass of the present application can be manufactured, processed, and discarded.

[0063] In order to achieve environmental friendliness, the optical glass of the present application preferably does not contain As2O3and PbO.

[0064] The "not to contain" and "0%" described herein mean that the compound, molecule, or element, etc. is not intentionally added as a raw material to the optical glass of the present application; however, as a raw material and / or equipment for producing the optical glass, some impurities or components that are not intentionally added can be contained in a small amount or trace amount in the final optical glass, and such a case is also within the scope of protection of the present application.

[0065] Next, the properties of the optical glass of the present application will be described.

[0066] <Refractive index and Abbe number>

[0067] The refractive index (n d ) and Abbe number (v d ) of the optical glass were measured according to the method prescribed in GB / T 7962.1-2010.

[0068] In some embodiments, the lower limit of the refractive index (n d ) of the optical glass of the present application is 1.86, preferably 1.87, and more preferably 1.875.

[0069] In some embodiments, the upper limit of the refractive index (n d ) of the optical glass of the present application is 1.91, preferably 1.90, and more preferably 1.89.

[0070] In some embodiments, the Abbe number (ν) of the optical glass of the present invention d The lower limit is 37, the preferred lower limit is 38, and the more preferred lower limit is 38.5.

[0071] In some embodiments, the Abbe number (ν) of the optical glass of the present invention d The upper limit of ) is 41, the preferred upper limit is 40.5, and the more preferred upper limit is 40.

[0072] <Coefficient of thermal expansion>

[0073] The coefficient of thermal expansion of optical glass (α) -30 / 70℃ Data for -30℃ to 70℃ were tested according to the method specified in GB / T7962.16-2010.

[0074] In some embodiments, the coefficient of thermal expansion (α) of the optical glass of the present invention is... -30 / 70℃ ) is 85×10 -7 / K or less, preferably 80×10 -7 / K or less, preferably 75×10 -7 / K or below.

[0075] <Stability under water resistance>

[0076] Water resistance stability of optical glass (D) W (Powder method) Tested according to the method specified in GB / T 17129.

[0077] In some embodiments, the water resistance stability (D) of the optical glass of the present invention is... W There are two or more categories, with category 1 being preferred.

[0078] <Stability under acid conditions>

[0079] Acid resistance stability of optical glass (D) A (Powder method) Tested according to the method specified in GB / T 17129.

[0080] In some embodiments, the acid resistance stability (D) of the optical glass of the present invention is... A There are two or more categories, with category 1 being preferred.

[0081] Knoop Hardness

[0082] Knoop hardness (H) of optical glass K The test shall be conducted according to the test method specified in GB / T7962.18-2010. In this invention, Knoop hardness is sometimes simply referred to as hardness.

[0083] In some embodiments, the Knoop hardness (H) of the optical glass of the present invention is... K) is 680 x 10 7 Pa or more, preferably 690 x 10 7 Pa or more, more preferably 700 x 10 7 Pa or more.

[0084] <Relative partial dispersion and relative partial dispersion deviation>

[0085] The relative partial dispersion (P g,F ) and the relative partial dispersion deviation (ΔP g,F ) are explained by the following equations.

[0086] The relative partial dispersion for wavelengths x and y is expressed by the following equation (1):

[0087] P x,y = (n x - n y ) / (n F - n C ) (1)

[0088] According to the Abbe number formula, for most so-called "normal glasses" (H-K6 and F4 are selected below as "normal glasses"), the following equation (2) is valid

[0089] P x,y = m x,y • v d + b x,y (2)

[0090] This linear relationship is expressed with P x,y as the ordinate and v d as the abscissa, where m x,y is the slope and b x,y is the intercept.

[0091] It is well known that correction of the second spectrum, i.e., achromatism for two or more wavelengths, requires at least one glass which does not conform to the above equation (2) (i.e., its P x,y value deviates from the Abbe empirical formula), and the deviation is expressed by ΔP x,y , then each P x,y - v d point is shifted by ΔP x,y with respect to the "normal line" which conforms to the above equation (2), and thus the ΔP x,y value of each glass can be calculated by the following equation (3):

[0092] P x,y = m x,y • v d + b x,y + ΔP x,y (3)

[0093] Therefore ΔP x,y The deviation of the special dispersion from the "normal glass" is quantitatively expressed.

[0094] Therefore, from the above, the calculation formulae of the relative partial dispersion (P g,F ) and the relative partial dispersion deviation value (ΔP g,F ) are as follows (4) and (5):

[0095] P g,F = (n g -n F ) / (n F -n C ) (4)

[0096] ΔP g,F = P g,F -0.6457+0.001703v d (5)

[0097] In some embodiments, the relative partial dispersion (P g,F ) of the optical glass of the present application is 0.7000 or less, preferably 0.6500 or less, and more preferably 0.6000 or less.

[0098] In some embodiments, the relative partial dispersion deviation value (ΔP g,F ) of the optical glass of the present application is -0.0020 or less, preferably -0.0040 or less, more preferably -0.0050 or less, and further preferably -0.0058 or less.

[0099] <Bubble degree>

[0100] The bubble degree of the optical glass is tested according to the method specified in GB / T 7962.8-2010.

[0101] In some embodiments, the bubble degree of the optical glass of the present application is A class or more, preferably A0 class or more, and more preferably A 00 class.

[0102] <Streak degree>

[0103] The streak degree of the optical glass is inspected from the direction in which the streaks are most easily seen, using a streak tester composed of a point light source and a lens, and compared with a standard sample, and classified into 4 grades, as shown in Table 1 below.

[0104] Table 1. Streak degree classification table

[0105] level degree of streak A no visible streak under the prescribed test conditions B fine and scattered streak under the prescribed test conditions C slight parallel streak under the prescribed test conditions D coarse parallel streak under the prescribed test conditions

[0106] In some embodiments, the streak degree of the optical glass of the present application is C class or more, and preferably B class or more.

[0107] <density>

[0108] The density (p) of the optical glass is tested according to the method specified in GB / T 7962.20-2010.

[0109] In some embodiments, the density (p) of the optical glass of the present application is 5.10 g / cm 3 In some embodiments, the density (p) of the optical glass of the present application is 5.00 g / cm 3 In some embodiments, the density (p) of the optical glass of the present application is 4.95 g / cm 3 In some embodiments, the density (p) of the optical glass of the present application is 4.90 g / cm

[0110] <Anti-crystallization property>

[0111] The anti-crystallization property of the optical glass of the present application is tested as follows: a glass sample with a size of 10 mm x 20 mm x 20 mm is placed in a semi-circular porcelain box with a radius of 15 mm and a depth of 15 mm, the glass sample and the porcelain box are placed in a test furnace set to a holding temperature of T g + 230°C for the first heating, and the heating time is 12 minutes, then taken out and lowered to 200°C in a tunnel annealing furnace; then placed in a test furnace set to a holding temperature of T g + 230°C for the second heating, and the heating time is 12 minutes, then taken out and lowered again to 200°C in a tunnel annealing furnace; then placed again in a test furnace set to a holding temperature of T g + 230°C for the third heating, and the heating time is 12 minutes. After the third heating, the glass sample and the porcelain box are placed in a tunnel annealing furnace and lowered to 200°C, and the glass sample is taken out and naturally cooled to room temperature in an atmospheric environment. After the glass sample is ground and polished, the softening degree and devitrification of the whole glass are observed by naked eye, and the internal glass is observed by microscope to confirm the existence of crystallization particles, and the anti-crystallization property of the glass is judged according to the following Table 2, with A being the best and E being the worst.

[0112] Table 2. Classification and judgment criteria of anti-crystallization property

[0113]

[0114] In some embodiments, the anti-crystallization property of the optical glass of the present application is C level or above, preferably B level or above, and more preferably A level.

[0115] [Manufacturing method of optical glass]

[0116] The optical glass of the present application is produced by a conventional method using conventional raw materials, including but not limited to oxides, hydroxides, complex salts (e.g., carbonates, nitrates, sulfates, etc.), boric acid, etc. The raw materials are mixed in a conventional manner, and the mixture is then melted in a 1200-1500°C melting furnace (e.g., a platinum or platinum alloy crucible). The molten glass is then clarified and homogenized to remove bubbles and undissolved substances, and the resulting homogeneous 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.

[0117] [Glass preform and optical element]

[0118] A glass preform can be produced from the optical glass produced by, for example, direct drop molding, or a molding method such as press molding, or hot press molding. That is, a glass preform can be produced by directly precision drop molding a molten optical glass into a glass precision preform, or by mechanical processing such as grinding and polishing, or by reheating and press molding a preform blank for press molding from an optical glass, and then polishing the preform blank. Note that the method of producing a glass preform is not limited to the above methods.

[0119] As described above, the optical glass of the present application is useful for various optical elements and optical designs, and it is particularly preferable to form a preform blank from the optical glass of the present application, and to use the preform blank to perform re-press molding, precision press molding, etc., to produce optical elements such as lenses and prisms.

[0120] The glass preform and the optical element of the present application are each formed from the above-described optical glass of the present application. The glass preform of the present application has the excellent properties of the optical glass; the optical element of the present application has the excellent properties of the optical glass, and can provide various optical elements such as lenses and prisms that have high optical value.

[0121] As examples of lenses, there are various lenses such as concave meniscus lenses, convex meniscus lenses, lenticular lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses, in which the lens surface is a spherical surface or an aspherical surface.

[0122] [Optical instrument]

[0123] The optical element formed from the optical glass of the present application can be used to produce optical instruments such as photographic equipment, video recording equipment, projection equipment, display equipment, vehicle-mounted equipment, and monitoring equipment.

[0124] Examples

[0125] [Optical glass examples]

[0126] In order to further clarify and illustrate the technical solutions of the present application, the following non-limiting examples are provided.

[0127] The optical glasses having the compositions shown in Tables 3 to 5 were obtained by the above-described method for producing optical glass. In addition, the properties of each glass were measured by the test methods described in the present application, and the measurement results are shown in Tables 3 to 5.

[0128] Table 3.

[0129]

[0130]

[0131] Table 4.

[0132]

[0133]

[0134] Table 5.

[0135]

[0136]

[0137] <Example of Glass Preform>

[0138] The glasses obtained in Examples 1 to 21 of optical glass were used to produce preforms of various lenses such as concave meniscus lenses, convex meniscus lenses, double convex lenses, double concave lenses, plano-convex lenses, plano-concave lenses, prisms, and the like, by means such as grinding processing, or molding processing such as reheat press molding, precision press molding, and the like.

[0139] <Example of Optical Element>

[0140] The preforms obtained in the above-described example of glass preform were annealed to reduce the internal stress of the glass while finely adjusting the refractive index, so that the optical properties such as the refractive index reached the desired values.

[0141] Next, each preform was ground and polished to produce various lenses such as concave meniscus lenses, convex meniscus lenses, double convex lenses, double concave lenses, plano-convex lenses, plano-concave lenses, prisms, and the like. The surface of the obtained optical element can also be coated with an anti-reflection film.

[0142] <Example of Optical Instrument>

[0143] The optical elements produced according to the above embodiments of the optical elements can be used, for example, in imaging devices, sensors, microscopes, medical technology, digital projection, communication, optical communication technology / information transmission, optics / illumination in the automotive sector, lithography technology, excimer lasers, wafers, computer chips, and integrated circuits and electronic devices comprising such circuits and chips, by optical design, by using one or more optical elements to form an optical component or optical assembly.

Claims

1. Optical glass, characterized in that, Its composition, expressed as a weight percentage, contains: SiO2: 4–11%; B2O3: 8–15%; La2O3: greater than 45% but less than or equal to 55%; Gd2O3: 2–9.5%; Y2O3: 4–10%; ZrO2: 3–10%; Nb2O5: 5–12%; TiO2: 0.1–5%; Al2O3: greater than 0 but less than or equal to 4%.

2. The optical glass according to claim 1, characterized in that, Its components, expressed as a weight percentage, also contain: ZnO: 0–4%; and / or RO: 0–5%; and / or Rn2O: 0–5%; and / or WO3: 0–5%; and / or Ta2O5: 0–5%; and / or Yb2O3: 0–5%; and / or GeO2: 0–4%; and / or clarifying agent: 0–1%, wherein the RO is one or more of MgO, CaO, SrO, and BaO, the Rn2O is one or more of Li2O, Na2O, and K2O, and the clarifying agent is one or more of Sb2O3, SnO2, and CeO2.

3. Optical glass, characterized in that, Its composition is expressed as a weight percentage: SiO2: 4–11%; B2O3: 8–15%; La2O3: greater than 45% but less than or equal to 55%; Gd2O3: 2–9.5%; Y2O3: 4–10%; ZrO2: 3–10%; Nb2O5: 5–12%; TiO2: 0.1–5%; Al2O3: greater than 0 but less than or equal to 4%. ZnO: 0-4%; RO: 0~5%; Rn2O: 0~5%; WO3: 0~5%; Ta2O5: 0~5%; Yb2O3: 0~5%; GeO2: 0~4%; Clarifying agent: 0-1% composition, wherein RO is one or more of MgO, CaO, SrO, and BaO, Rn2O is one or more of Li2O, Na2O, and K2O, and the clarifying agent is one or more of Sb2O3, SnO2, and CeO2.

4. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: Gd2O3 / Y2O3 is 0.25 to 1.1, preferably 0.3 to 1.0, more preferably 0.4 to 0.9, and even more preferably 0.5 to 0.

9.

5. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: Gd2O3 / SiO2 is 0.2 to 1.0, preferably 0.3 to 0.95, more preferably 0.4 to 0.9, and even more preferably 0.5 to 0.

9.

6. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: Al2O3 / TiO2 is 0.05 to 3.0, preferably Al2O3 / TiO2 is 0.1 to 2.0, more preferably Al2O3 / TiO2 is 0.1 to 1.5, and even more preferably Al2O3 / TiO2 is 0.2 to 1.

0.

7. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is 0.9 to 4.0, preferably Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is 1.0 to 3.5, more preferably Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is 1.0 to 3.0, and even more preferably Y2O3 / (Gd2O3+Ta2O5+ZnO+WO3+GeO2) is 1.2 to 2.

0.

8. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: (La2O3+Y2O3) / (Nb2O5+ZrO2) is 2.5 to 6.5, preferably (La2O3+Y2O3) / (Nb2O5+ZrO2) is 2.8 to 6.0, more preferably (La2O3+Y2O3) / (Nb2O5+ZrO2) is 3.0 to 5.5, and even more preferably (La2O3+Y2O3) / (Nb2O5+ZrO2) is 3.5 to 5.

0.

9. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: (TiO2+ZnO+Ta2O5+WO3) / Nb2O5 is 0.01 to 1.0, preferably (TiO2+ZnO+Ta2O5+WO3) / Nb2O5 is 0.05 to 0.8, more preferably (TiO2+ZnO+Ta2O5+WO3) / Nb2O5 is 0.1 to 0.5, and even more preferably (TiO2+ZnO+Ta2O5+WO3) / Nb2O5 is 0.1 to 0.

3.

10. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: Al2O3 / Gd2O3 is 0.02 to 0.8, preferably Al2O3 / Gd2O3 is 0.05 to 0.6, more preferably Al2O3 / Gd2O3 is 0.1 to 0.5, and even more preferably Al2O3 / Gd2O3 is 0.1 to 0.

4.

11. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: (La2O3+Nb2O5) / Gd2O3 is 6.0 to 23.0, preferably (La2O3+Nb2O5) / Gd2O3 is 8.0 to 20.0, more preferably (La2O3+Nb2O5) / Gd2O3 is 9.0 to 15.0, and even more preferably (La2O3+Nb2O5) / Gd2O3 is 10.0 to 13.

0.

12. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: Nb2O5 / Y2O3 is 0.6 to 2.0, preferably 0.7 to 1.7, more preferably 0.8 to 1.5, and even more preferably 0.9 to 1.

2.

13. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: (Ta2O5+ZnO+RO) / TiO2 is 2.5 or less, preferably (Ta2O5+ZnO+RO) / TiO2 is 1.5 or less, more preferably (Ta2O5+ZnO+RO) / TiO2 is 1.0 or less, and even more preferably (Ta2O5+ZnO+RO) / TiO2 is 0.5 or less, wherein RO is one or more of MgO, CaO, SrO, and BaO.

14. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: Al2O3 / SiO2 is 0.01 to 0.8, preferably Al2O3 / SiO2 is 0.05 to 0.6, more preferably Al2O3 / SiO2 is 0.08 to 0.5, and even more preferably Al2O3 / SiO2 is 0.1 to 0.

3.

15. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: SiO2: 5-10%, preferably SiO2: 5.5-9%; and / or B2O3: 10-14%, preferably B2O3: 11-13.5%; and / or La2O3: 46-53%, preferably La2O3: 48-52%; and / or Gd2O3: 3-8%, preferably Gd2O3: 4-7%; and / or Y2O3: 5-9.5%, preferably Y2O3: 5.5-8.5%; and / or ZrO2: 4-9%, preferably ZrO2: 5-8%; and / or Nb2O5: 5.5-11%, preferably Nb2O5: 6-10%; and / or TiO2: 0.5-4%, preferably TiO2: 1-3%; and / or Al2O3: 0.1-3%, preferably Al2O3: 0.5-2%; and / or Or ZnO: 0-2%, preferably ZnO: 0-1%; and / or RO: 0-3%, preferably RO: 0-1%; and / or Rn2O: 0-3%, preferably Rn2O: 0-1%; and / or WO3: 0-3%, preferably WO3: 0-1%; and / or Ta2O5: 0-3%, preferably Ta2O5: 0-1%; and / or Yb2O3: 0-3%, preferably Yb2O3: 0-1%; and / or GeO2: 0-2%, preferably GeO2: 0-1%; and / or clarifying agent: 0-0.5%, preferably clarifying agent: 0-0.1%, wherein the RO is one or more of MgO, CaO, SrO, and BaO, the Rn2O is one or more of Li2O, Na2O, and K2O, and the clarifying agent is one or more of Sb2O3, SnO2, and CeO2.

16. The optical glass according to any one of claims 1 to 3, characterized in that, Its components do not contain ZnO; and / or MgO; and / or CaO; and / or SrO; and / or BaO; and / or Li2O; and / or Na2O; and / or K2O; and / or WO3; and / or Ta2O5; and / or Yb2O3; and / or GeO2; and / or Sb2O3; and / or SnO2; and / or CeO2.

17. The optical glass according to any one of claims 1 to 3, characterized in that, The refractive index n of the optical glass d The Abbe number is 1.86–1.91, preferably 1.87–1.90, and more preferably 1.875–1.89; d The value is 37 to 41, preferably 38 to 40.5, and more preferably 38.5 to 40.

18. The optical glass according to any one of claims 1 to 3, characterized in that, The coefficient of thermal expansion of the optical glass is α -30 / 70℃ 85×10 -7 / K or less, preferably 80×10 -7 / K or less, preferably 75× 10 -7 / K or below; and / or water resistance stability D W It is classified as Class 2 or above, preferably Class 1; and / or acid resistance stability D A It is classified as Class 2 or above, preferably Class 1; and / or Knoop hardness H K 680×10 7 Pa or higher, preferably 690 × 10⁻⁶ 7 Pa or higher, more preferably 700 × 10 Pa 7 Pa or above; and / or relative partial dispersion P g,F The value is 0.7000 or less, preferably 0.6500 or less, more preferably 0.6000 or less; and / or the relative partial dispersion deviation value ΔP g,F The bubble density is -0.0020 or less, preferably -0.0040 or less, more preferably -0.0050 or less, and even more preferably -0.0058 or less; and / or the bubble density is A grade or higher, preferably A0 grade or higher, and more preferably A. 00 Grade; and / or striation grade C or above, preferably grade B or above; and / or density ρ of 5.10 g / cm³. 3 The preferred value is 5.00 g / cm³. 3 The preferred value is 4.95 g / cm³. 3 The following are acceptable: and / or the anti-crystallization performance is grade C or above, preferably grade B or above, and more preferably grade A.

19. A glass preform, characterized in that, It is made of the optical glass described in any one of claims 1 to 18.

20. An optical element, characterized in that, It is made of optical glass as described in any one of claims 1 to 18, or of glass preform as described in claim 19.

21. An optical instrument, characterized in that, It contains the optical glass according to any one of claims 1 to 18, and / or contains the optical element according to claim 20.

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