An environmentally friendly, high-transparency H-ZK type glass and its preparation method

Abstract

This invention provides an optical glass with improved transmittance and superior formability, with a refractive index of 1.58-1.60 and an Abbe number of 60-62, providing options for miniaturization and weight reduction of optical lenses. Furthermore, this optical glass does not contain PbO, As2O3, or other environmentally unfriendly elements, and is composed of the following components by weight percentage: SiO2 37-42%, B2O3 13-16%, BaO 35-40%, Al2O3 1-2%, Na2O 2-3%, K2O 3-4%, CaO 0-1%, and Sb2O3 0-1%.

Description

Technical Field

[0001] This invention relates to an environmentally friendly, high-transparency H-ZK type glass and its preparation method, belonging to the field of glass preparation, specifically an optical glass and its preparation method. Background Technology

[0002] In recent years, with the development of the optoelectronic industry, the requirements for the light transmittance of optical lenses in digital cameras, telescopes, and mobile phones, both domestically and internationally, have become increasingly stringent. These lenses are becoming smaller while requiring wider fields of view, necessitating optical glass with excellent transmittance and a trend towards miniaturization, lightweighting, and high performance. Currently, traditional H-ZK type glass has a tinting degree of 350 / 300 at λ80 / λ5, resulting in relatively low transmittance. This invention provides an optical glass with a tinting degree of 335 / 280 at λ80 / λ5, and improved transmittance, based on this glass grade. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an optical glass with improved transmittance and superior forming performance, with a refractive index of 1.58-1.60 and an Abbe number of 60-62, which provides options for miniaturization and weight reduction of optical lenses. At the same time, the optical glass does not contain other environmentally unfriendly elements such as PbO and As2O3.

[0004] This invention provides an environmentally friendly, high-transparency optical glass, composed of the following components by weight percentage:

[0005]

[0006]

[0007] SiO2 is a glass-forming oxide that forms an irregular, continuous network of silicon-oxygen tetrahedral structural components, constituting the framework of the glass. By adjusting the viscosity, refractive index, and Abbe number of the glass, the SiO2 content in this invention is controlled at 37–42%.

[0008] B2O3 is also a glass-forming oxide that can improve melting performance, reduce glass viscosity, and also has the function of adjusting glass refractive index and Abbe number. In this invention, B2O3 is introduced in the form of H3BO3, with the content controlled at 13-16%.

[0009] In this invention, BaO is an effective component that can improve the devitrification of glass and adjust the high-temperature viscosity and chemical stability of glass. In this invention, BaO is introduced in the form of barium carbonate and barium nitrate, and the content should be controlled at 35-40%.

[0010] Al2O3 can form the skeleton of glass, effectively improving the mechanical properties of glass and reducing the coefficient of thermal expansion of glass. However, when the content is high, the glass transition temperature and liquidus temperature increase, making glass melting more difficult and increasing the forming temperature. In this invention, the content is controlled at 1-2%.

[0011] Alkali metal oxides Na₂O and K₂O are both glass components and improve glass melting properties. In this formulation, the sodium oxide content is 2-3%, but the total content of Na₂O and K₂O should not be excessive, as these components reduce glass viscosity and worsen its chemical stability and devitrification resistance. Therefore, the total content of Na₂O and K₂O is limited to 5-7%.

[0012] Alkaline earth metal CaO can be used to adjust the refractive index and Abbe number of glass, and its content is limited to 0-1%.

[0013] To promote clarification during glass melting, 0-1% Sb2O3 can be added as a clarifying agent.

[0014] This invention also provides a method for preparing the above-mentioned optical glass, the specific steps of which are as follows:

[0015] (1) Weigh each raw material according to the ratio, and use a V-shaped mixer to stir each component raw material for 10-15 minutes to mix them evenly.

[0016] (2) The chemical raw materials that are mixed evenly in step (1) are put into the furnace, heated by combustion in the all-oxygen system, and melted into liquid glass by means of heating by electric current through the bottom electrode. The heating temperature of the top of the melting pool is set to 1280~1310℃, and the melting time is 28~35h.

[0017] (3) The molten glass in the furnace is drawn into the heating pool through the drain pipe between the furnace and the heating pool to heat the glass and prepare it for clarification. The temperature of the heating pool area is set to 1460~1490℃.

[0018] (4) The heated glass continues to flow into the clarification tank to clarify and remove bubbles in the glass to meet the glass quality target requirements. The temperature of the clarification tank area is set to 1450~1480℃.

[0019] (5) After the bubbles are removed, the glass continues to flow into the cooling area to absorb some of the difficult-to-clarify and some invisible bubbles, and at the same time, the temperature of the glass reaches a suitable stirring temperature to prepare the glass to enter the working area for stirring; the temperature of the cooling area is set to 1000~1100℃.

[0020] (6) The cooled glass flows into the homogenization and stirring tank, also called the working tank, where the internal striations of the glass are eliminated to meet the glass quality target requirements; the temperature of the homogenization tank is 1050~1100℃.

[0021] (7) The glass after the above (6) treatment is solidified by traction through a platinum tube and then enters a coarse annealing mesh belt annealing furnace. The forming temperature is 1050-1130℃, the forming time is 5-10 min, and the annealing time is 5-16 h, thus obtaining the optical glass.

[0022] The beneficial effects of this invention are: the optical glass of this invention has a simple composition, a refractive index of 1.58-1.60, an Abbe number of 60-62, and does not contain environmentally unfriendly or expensive elements such as PbO and As2O3. It has excellent optical transmittance and good melt forming performance. Moreover, the composition does not contain lithium carbonate or rare earth elements, and the formulation and production cost are relatively low. Detailed Implementation

[0023] The preferred embodiments of the present invention are described below. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0024] Examples 1-8

[0025] Optical glass was prepared according to the composition in Table 1, and the refractive index of the glass was measured according to the test method of GB / T7962.11.

[0026] Table 1

[0027] Components Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 <![CDATA[SiO2]]> 39.85 38.84 40.80 39.75 38.78 39.19 40.20 39.79 B2O3 15.11 15.00 15.09 15.18 15.09 15.23 15.23 15.09 BaO 37.78 38.74 36.77 37.74 38.79 38.18 37.14 37.78 <![CDATA[Sb2O3]]> 0.05 0.05 0.08 0.08 0.08 0.05 0.08 0.08 Al2O3 1.21 1.26 1.22 1.22 1.22 1.24 1.24 1.22 CaO 0.25 0.25 0.27 0.27 0.27 0.28 0.28 0.27 <![CDATA[Na2O]]> 2.47 2.58 2.48 2.47 2.48 2.50 2.50 2.48 <![CDATA[K2O]]> 3.28 3.28 3.29 3.29 3.29 3.33 3.33 3.29 λ80 337 336 338 337 336 337 335 335 λ5 285 285 285 286 283 286 283 281 nd 1.58925 1.5892 1.58635 1.58863 1.59211 1.58763 1.59063 1.58913 nf-nc 0.009625 0.009618 0.0096 0.009588 0.009625 0.009605 0.009648 0.009618 vd 61.22 61.26 61.08 61.39 61.52 61.18 61.22 61.25

[0028] As can be seen from the above embodiments, the optical glass of the present invention has a refractive index nd of 1.58-1.60 and an Abbe number of 60-62. At the same time, the tinting strength and transmittance at λ80 / λ5 are greatly improved, and it also has good melt forming performance, achieving production stability of continuous melting. Moreover, the composition does not contain expensive elements such as lithium carbonate and rare earth elements, and the formula and production cost are relatively low. In addition, the glass composition does not contain PbO and AsO, which are environmentally friendly optical glass.

[0029] Principles and steps not explicitly described in this invention are all obtainable by those skilled in the art through conventional technical means, and therefore will not be elaborated upon. Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing environmentally friendly high-transmittance optical glass, characterized in that, Includes the following steps: (1) Weigh each raw material according to the proportion, and use a V-shaped mixer to mix each component raw material evenly for 10-15 minutes; (2) The chemical raw materials that are mixed evenly in step (1) are put into the furnace, heated by combustion in the all-oxygen system, and melted into liquid glass by means of heating by electric current through the bottom electrode. The heating temperature of the top of the melting pool is set to 1280~1310℃, and the melting time is 28~35h. (3) The molten glass in the furnace is drawn into the heating pool through the drain pipe between the furnace and the heating pool to heat the glass and prepare it for clarification. The temperature of the heating pool area is set to 1460~1490℃. (4) The heated glass continues to flow into the clarification tank to clarify and remove bubbles in the glass, so as to meet the glass quality target requirements. The temperature of the clarification tank area is set to 1450~1480℃. (5) After the bubbles are removed, the glass continues to flow into the cooling section area to absorb some of the difficult-to-clarify and some invisible bubbles, and at the same time, the temperature of the glass reaches a suitable stirring temperature to prepare the glass to enter the working area for stirring; the temperature of the cooling section is set to 1000~1100℃. (6) After cooling, the glass flows into the homogenization mixing tank, also called the working tank, where the internal striations of the glass are eliminated to meet the glass quality target requirements; the temperature of the homogenization tank is 1050~1100℃. (7) The glass after being processed by the above step (6) is solidified by traction through a platinum tube and then enters a coarse annealing mesh belt annealing furnace. The forming temperature is 1050-1130℃, the forming time is 5-10 min, and the annealing time is 5-16 h, thus obtaining the optical glass. The optical glass is composed of the following components by weight percentage: SiO2 37~42% B2O3 13~16% BaO 35~40% Al2O3 1.21~1.26% Na₂O 2.47~2.58% K₂O 3.28~3.33% CaO 0.25~0.28% Sb₂O₃ 0.05~0.08%; The optical glass has a refractive index nd of 1.58-1.60 and an Abbe number of 61.08-61.

52.

2. The method according to claim 1, characterized in that, The optical glass is composed of the following components by weight percentage: SiO2 39.85% B2O3 15.11% BaO 37.78% Sb₂O₃ 0.05% Al2O3 1.21% CaO 0.25% Na2O 2.47% K2O 3.28%.

3. The method according to claim 1, characterized in that, The optical glass is composed of the following components by weight percentage: SiO2 38.84% B2O3 15% BaO 38.74% Sb₂O₃ 0.05% Al2O3 1.26% CaO 0.25% Na2O 2.58% K2O 3.28%.

4. The method according to claim 1, characterized in that, The optical glass is composed of the following components by weight percentage: SiO2 40.8% B2O3 15.09% BaO 36.77% Sb₂O₃ 0.08% Al2O3 1.22% CaO 0.27% Na2O 2.48% K2O 3.29%.

5. The method according to claim 1, characterized in that, The optical glass is composed of the following components by weight percentage: SiO2 39.75% B2O3 15.18% BaO 37.74% Sb₂O₃ 0.08% Al2O3 1.22% CaO 0.27% Na2O 2.47% K2O 3.29%.

6. A method according to claim 1, characterized in that, The optical glass is composed of the following components by weight percentage: SiO2 38.78% B2O3 15.09% BaO 38.79% Sb₂O₃ 0.08% Al2O3 1.22% CaO 0.27% Na2O 2.48% K2O 3.29%.

7. The method according to claim 1, characterized in that, The optical glass is composed of the following components by weight percentage: SiO2 39.19% B2O3 15.23% BaO3 8.18% Sb₂O₃ 0.05% Al2O3 1.24% CaO 0.28% Na2O 2.5% K2O 3.33%.

8. The method according to claim 1, characterized in that, The optical glass is composed of the following components by weight percentage: SiO2 40.2% B2O3 15.23% BaO 37.14% Sb₂O₃ 0.08% Al2O3 1.24% CaO 0.28% Na2O 2.5% K2O 3.33%.

9. A method according to claim 1, characterized in that, The optical glass is composed of the following components by weight percentage: SiO2 39.79% B2O3 15.09% BaO 37.78% Sb₂O₃ 0.08% Al2O3 1.22% CaO 0.27% Na2O 2.48% K2O 3.29%.

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