Glass composition, high-refraction glass and preparation method and application of high-refraction glass

Abstract

The invention relates to a glass composition, high-refraction glass as well as a preparation method and application of the high-refraction glass. The glass composition comprises SiO2, TiO2, Nb2O5, Na2O, K2O, CaO and BaO. The glass composition is prepared from the following components in percentage by weight: 18.5 to 23 percent of SiO2, 25.5 to 30 percent of TiO2, 27.5 to 32 percent of Nb2O5, 5 to 10 percent of Na2O, 1 to 6 percent of K2O, 1 to 8 percent of CaO and 2.5 to 10 percent of BaO, wherein the total mass of the glass composition is 100 percent by weight, and the glass composition is prepared from the following components in percentage by weight: 18.5 to 23 percent of SiO2, 25.5 to 30 percent of TiO2, 27.5 to 32 percent of Nb2O5, 5 to 10 percent of Na2O, 1 to 6 percent of K2O, 1 to 8 percent of CaO and 2.5 to 10 percent of BaO. The glass composition provided by the invention and the content are cooperated, so that the glass composition can have high refractive index while ensuring low density and reducing cost, and the goals of high refractive index and low density are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical glass and optical elements, in particular to a glass composition, a high-refractive glass and a preparation method and use thereof. BACKGROUND

[0002] With the development of AR (Augmented Reality) technology, the application of optical glass will be more used in the fields of automobile automatic driving, optical information science, augmented reality and mixed reality (AR, MR) and the like. The optical waveguide scheme has advantages in terms of clarity, viewing angle, volume and the like, and thus becomes the best optical display scheme in the current augmented reality glasses, and is expected to become the mainstream optical display solution for AR glasses.

[0003] The refractive index of optical glass is an important parameter affecting the field of view (FOV) of an optical system, and a high refractive index of optical glass is conducive to improving the optical clarity of electronic products and electronic components, and the user's field of view is wider and the experience is better. The weight of the optical glass will affect the design parameters such as thickness, curvature and radius of the lens, and the lighter the weight, the more diversified the virtual reality and augmented reality device design can be.

[0004] The existing high-refractive glass mainly adds a high content of lanthanum oxide, so that the glass has a high refractive index. However, the introduction of excessive rare earth element lanthanum oxide will increase the density of the glass, which is not conducive to user experience and will also increase the manufacturing cost.

[0005] Therefore, how to provide a glass composition and optical glass with high transmittance, high refractive index and low density has become a problem to be solved at present. SUMMARY

[0006] To solve the above technical problems, the present application aims to provide a glass composition, a high-refractive glass and a preparation method and use thereof, and the glass composition has the advantages of high transmittance, high refractive index and low density.

[0007] To achieve this purpose, the present application adopts the following technical solutions:

[0008] In a first aspect, the present application provides a glass composition, which comprises SiO2, TiO2, Nb2O5, Na2O, K2O, CaO and BaO.

[0009] The content of SiO2 is 18.5wt%-23wt%, for example, it can be 18.5wt%, 20wt%, 20.5wt%, 21wt%, 21.5wt%, 22wt%, 22.5wt% or 23wt%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0010] The glass composition in the present application introduces SiO2, which can be the main body of the glass network structure. If the content of SiO2 is low, it is not easy to form glass, the expansion coefficient is large, and the mechanical properties and chemical stability are poor. Increasing the content of SiO2 can improve the mechanical strength and stability of the glass. The content of SiO2 in the present application is 18.5%-23wt%, and the content of SiO2 is too high, which reduces the refractive index of the glass, so the content needs to be controlled within a suitable range.

[0011] The content of TiO2 is 25.5wt%-30wt% based on the total mass of the glass composition, for example, it can be 25.5wt%, 26wt%, 26.5wt%, 27wt%, 27.5wt%, 28wt%, 28.5wt%, 29wt%, 29.5wt% or 30wt%, but not limited to the listed values, other values not listed in the value range are also applicable.

[0012] The glass composition in the present application introduces TiO2, which is very beneficial to high refractive index and high dispersion. In addition, it is helpful for low specific gravity in high refractive index components. The content of TiO2 in the present application is 25.5wt%-30wt%. If the mass percentage of the TiO2 component is low, it is difficult to ensure a high refractive index of the glass. If the mass percentage of the TiO2 component is too high, the glass color will be intensified, and the light transmittance of the optical glass will be poor.

[0013] The content of Nb2O5 is 27.5wt%-32wt% based on the total mass of the glass composition, for example, it can be 27.5wt%, 28wt%, 28.5wt%, 29wt%, 29.5wt%, 30wt%, 30.5wt%, 31wt%, 31.5wt% or 32wt%, but not limited to the listed values, other values not listed in the value range are also applicable.

[0014] The glass composition in the present application introduces the Nb2O5 component, which helps to improve the glass forming properties, thermal stability and refractive index of the optical glass. The content of Nb2O5 in the present application is 27.5wt%-32wt%. If the content of Nb2O5 is low, the refractive index of the glass is not obviously improved. When the content of Nb2O5 becomes too much, the melting temperature rises, the thermal stability of the glass decreases, the optical uniformity of the glass becomes poor, the density of the glass is large, and the glass has a tendency to color.

[0015] The content of Na2O is 5wt%-10wt%, for example, it can be 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt% or 10wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0016] The introduction of Na2O in the glass composition of the present application reduces the liquidus temperature of the glass and improves the devitrification resistance of the glass; the content of Na2O is 5wt%-10wt%, and a lower content of Na2O makes it difficult to ensure the glass-forming property of the glass; however, a higher content of Na2O makes it difficult to maintain the refractive index and Abbe number.

[0017] The content of K2O is 1wt%-6wt% based on the total mass of the glass composition, for example, it can be 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt% or 6wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0018] The introduction of K2O in the glass composition of the present application is necessary for improving the glass-forming property and whiteness of the glass, and the content of K2O is 1wt%-6wt%; if the content of K2O component is low, it is difficult to ensure the glass-forming property and whiteness of the glass; and if the content of K2O component is high, it will result in a decrease in the refractive index of the glass.

[0019] The content of CaO is 1wt%-8wt% based on the total mass of the glass composition, for example, it can be 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt% or 8wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0020] The introduction of CaO in the glass composition of the present application is beneficial to reducing the high-temperature melting temperature of the glass, adjusting the formability of the glass, and reducing the high-temperature crystallization tendency; CaO provides the highest refractive index of the glass and lower density. In addition, CaO can help increase the solubility of Nb2O5 and TiO2 in the glass; the content of CaO is 1wt%-8wt%, and a too high amount of CaO in the glass may result in difficult-to-melt substances such as calcium titanate (CaTiO3, CaTi2O5), calcium niobate (CaNb2O6), calcium metasilicate (CaSiO3) and the like, which may reduce the viscosity at the liquidus temperature.

[0021] The content of BaO is 2.5wt%-10wt%, for example, can be 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt% or 10wt%, but not limited to the listed values, other values not listed in the range are also applicable.

[0022] The glass composition in the application introduces BaO, which can help maintain the glass melting property and improve the glass stability; not only makes the prepared optical glass have good glass forming property, but also helps to improve the refractive index of the optical glass; the content of BaO in the application is 2.5wt%-10wt%, if the addition amount of BaO is too much, the density of the glass increases, and the weather resistance of the glass will quickly decrease; it may lead to the crystallization of difficult-to-melt substances such as barium titanate (BaTiO3), barium niobate (BaNb2O6) and other substances, which may reduce the viscosity at the liquidus temperature.

[0023] The glass composition provided by the application realizes the beneficial effects of high refractive index and low density through the synergistic cooperation between the raw material components and the content without introducing rare earth elements.

[0024] The following is a preferred technical solution of the application, but not as a limitation on the technical solutions provided by the application, through the following preferred technical solution, the technical purpose and beneficial effect of the application can be better achieved and realized.

[0025] Preferably, the content of SiO2 is 20wt%-22.5wt%, the content of TiO2 is 26wt%-28.5wt%, the content of Nb2O5 is 28wt%-30.5wt%, the content of Na2O is 5.5wt%-8wt%, the content of K2O is 1.5wt%-4wt%, the content of CaO is 4.5wt%-7wt%, and the content of BaO is 4.5wt%-9.5wt%, based on the total mass of the glass composition being 100wt%.

[0026] Preferably, the glass composition does not contain lanthanum elements.

[0027] Traditional high refractive index glass often relies on a large amount of heavy metal oxides (such as rare earth oxides), which will significantly increase the density of the glass and may cause coloring problems (such as making the glass appear yellow-brown) and high cost, the glass composition provided by the application does not introduce rare earth lanthanum elements, ensures low density and reduces cost, and at the same time can have high refractive index, realizes the goal of high refractive index and low density.

[0028] Preferably, the mass fraction of each component in the glass composition satisfies the following formula (1):

[0029] 0.04≤A=(SiO2-Na2O-K2O) / (TiO2+Nb2O5)≤0.32 (1).

[0030] The present application further controls 0.04≤A=(SiO2-Na2O-K2O) / (TiO2+Nb2O5)≤0.32, SiO2 forms the basic skeleton structure of the glass in the form of silicon-oxygen tetrahedron [SiO4], which has the advantages of improving the high-temperature viscosity of the glass, maintaining the viscosity suitable for glass forming, keeping the appropriate expansion coefficient and the high refractive index; if the component content exceeds the range, the refractive index will be reduced.

[0031] Preferably, the mass fraction of each component in the glass composition satisfies the following formula (2):

[0032] 0.33≤B=(Na2O+K2O) / (CaO+BaO)≤4.57 (2).

[0033] The present application further controls 0.33≤B=(Na2O+K2O) / (CaO+BaO)≤4.57, which utilizes the double-alkali effect of alkali metal and alkaline earth metal, and at the same time, gives the glass suitable high-temperature melting performance and forming performance, and maintains the chemical stability of the glass such as water resistance and acid resistance; if the component content exceeds the range, the water resistance and acid resistance of the high-refractive glass will be poor.

[0034] Preferably, the mass fraction of each component in the glass composition satisfies the following formula (3):

[0035] 2.21≤C=(TiO2+Nb2O5) / (Na2O+K2O+CaO+BaO)≤3.18 (3).

[0036] The present application further controls 2.21≤C=(TiO2+Nb2O5) / (Na2O+K2O+CaO+BaO)≤3.18, the presence of alkali metal and alkaline earth metal can help to increase the solubility of Nb2O5 and TiO2 in the glass, and further ensure the high refractive index and the low density; if the component content exceeds the range, the density of the high-refractive glass will be increased.

[0037] In the second aspect, the present application provides a high-refractive glass prepared from the glass composition of the first aspect.

[0038] The refractive index nd of the high-refractive glass satisfies nd≥(ρ-3.5)+1.769, wherein ρ represents the density.

[0039] The high-refractive glass provided by the application has low density and high refractive index and light transmittance, and the glass is thinner and lighter and has high refractive index, which is more convenient for subsequent use.

[0040] Preferably, the density of the high-refractive glass is ≤3.6533 g / cm 3 , T550nm≥81.6, water resistance 1st level, acid resistance 1st level, expansion coefficient ≤9.73×10 -6 / ℃, refractive index nd≥1.9033, Abbe number Vd≥21.7.

[0041] In a third aspect, the application provides a preparation method of the high-refractive glass according to the second aspect, and the preparation method comprises the following steps:

[0042] The glass composition according to the first aspect and a fining agent are mixed, heated and melted at 1250-1350℃ for 2-8h, and then formed and annealed to obtain the high-refractive glass.

[0043] Preferably, the fining agent is sodium chloride and / or mirabilite, and the mass of the fining agent is 0.1wt%-0.3wt% of the mass of the raw materials for the glass, for example, it can be 0.1wt%, 0.15wt%, 0.2wt%, 0.25wt% or 0.3wt%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0044] For example, the more specific preparation method of the application comprises the following steps: according to the designed glass composition, the required glass raw materials are calculated, the fining agent is NaNO3, and the addition amount is 0.2wt% of the total amount of the batch, the glass raw materials are mixed uniformly, the mixed material is poured into a platinum-rhodium crucible, then heated at 1250-1350℃ for 4h and mixed uniformly, then the crucible is taken out, the melted glass liquid is poured into a preheated mold to pour into a block, after forming, it is placed in a muffle furnace at 610℃ for 2h for precision annealing treatment, and then taken out when the muffle furnace is cooled to room temperature to obtain the high-refractive glass.

[0045] Other glass preparation processes can also be used in the application, and when the glass composition content meets the range according to the first aspect, the high-refractive glass with excellent performance can be obtained.

[0046] In a fourth aspect, the application provides a use of the high-refractive glass according to the second aspect, and the high-refractive glass is used in virtual reality and augmented reality devices, optical assemblies or optical lenses.

[0047] Preferably, the glass composition is used in VR glasses, AR glasses or MR glasses.

[0048] The high-refractive glass provided by the application can reduce the density of the glass, significantly reduce the overall weight of the optical assembly or device, improve the wearing comfort, and allow the lens to be thinner under the premise of ensuring the same optical performance. The high-performance glass material can effectively reduce optical aberration and improve light transmittance, thereby bringing the user a clearer, more realistic and immersive visual experience, and promoting the development and use of consumer-grade AR devices.

[0049] The numerical range described in the application includes not only the point values listed above, but also any point values between the above numerical ranges that are not listed. Due to the limited space and for the sake of simplicity, the application does not exhaustively list the specific point values included in the range.

[0050] Compared with the prior art, the application has at least the following beneficial effects:

[0051] (1) The glass composition provided by the application can realize high refractive index and low density without introducing rare earth elements, and can have high refractive index while ensuring low density and reducing cost.

[0052] (2) The high-refractive glass provided by the application can reduce the density of the glass, significantly reduce the overall weight of the optical assembly or device, improve the wearing comfort, and allow the lens to be thinner under the premise of ensuring the same optical performance. The high-performance glass material can effectively reduce optical aberration and improve light transmittance, thereby bringing the user a clearer, more realistic and immersive visual experience, and promoting the development and use of consumer-grade AR devices. DETAILED DESCRIPTION

[0053] The technical solutions of the application will be further described through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the application and should not be regarded as specific limitations on the application.

[0054] In the application, the terms "first", "second", "third", "fourth" and the like are only used for description purposes and should not be understood as indicating or implying relative importance or quantity, nor should they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth" and the like only serve the purpose of non-exhaustive enumeration and description, and should be understood as not constituting a closed limitation on the quantity.

[0055] In the following examples and comparative examples, all reagents and consumables were purchased from conventional reagent manufacturers in the art unless otherwise specified. Unless otherwise specified, the experimental methods and technical means used were conventional methods and means in the art.

[0056] Example 1

[0057] The embodiment provides a glass composition, the glass composition comprising SiO2, TiO2, Nb2O5, Na2O, K2O, CaO and BaO, specific mass percentage contents and values of A=(SiO2-Na2O-K2O) / (TiO2+Nb2O5), B=(Na2O+K2O) / (CaO+BaO) and C=(TiO2+Nb2O5) / (Na2O+K2O+CaO+BaO) are shown in Table 1.

[0058] The embodiment provides a preparation method of the high-refraction glass, which comprises the following steps:

[0059] According to the designed glass composition, required glass raw materials are calculated, the clarifying agent is NaNO3, and the addition amount is 0.2 wt% of the total amount of the batch. The glass raw materials are uniformly mixed. The mixture is poured into a platinum-rhodium crucible, and then heated at 1300 DEG C. for 4 h and uniformly mixed. Then, the crucible is taken out, the melted glass liquid is poured into a preheated mold to pour into a block, after forming, it is placed in a muffle furnace at 610 DEG C. for 2 h, and then subjected to precision annealing treatment, and then taken out when the muffle furnace is cooled to room temperature, to obtain the high-refraction glass.

[0060] Embodiment 2-Embodiment 10

[0061] Embodiment 2-Embodiment 10 respectively provide a glass composition, the content of the respective glass composition is shown in Table 1, and the preparation method of the high-refraction glass is the same as that in Embodiment 1.

[0062] Comparative Embodiment 1-Comparative Embodiment 3

[0063] Comparative Embodiment 1-Comparative Embodiment 3 respectively provide a glass composition, the content of the respective glass composition is shown in Table 1, and the preparation method of the high-refraction glass is the same as that in Embodiment 1.

[0064] Test method:

[0065] (1) Glass density: determined according to ASTM C-693, unit: g / cm 3 .

[0066] (2) Glass thermal expansion coefficient: determined according to ASTM E-228 using a horizontal dilatometer to determine the glass thermal expansion coefficient at 50 DEG C.-350 DEG C., unit: 10 -6 / ℃.

[0067] (3) Transmittance: determined using a UV-2600 ultraviolet visible spectrophotometer to determine the transmittance corresponding to a wavelength of 550 nm.

[0068] (4) Chemical stability test: The method of JBT10576-2006 Chemical Stability Test of Colorless Optical Glass was used.

[0069] (5) Refractive index: The refractive index of the glass sample was measured using a Metricon 2010 prism coupler refractometer, and the Abbe number (νd) was calculated according to νd = (nd-1) / (nF-nC). The refractive index of the glass sample was measured at two or more wavelengths of about 447 nm, 519 nm, 637 nm using Metricon. The correlation measured characterizes the dispersion, which is then fitted using Cauchy's law equation or Sellmeier equation, where nd is the calculated refractive index at 587.6 nm (d line segment), nF is the calculated refractive index at 486.1 nm, and nC is the calculated refractive index at 656.3 nm.

[0070] The physicochemical properties of the high-refractive glass prepared in the examples and comparative examples were tested using the above method, and the test results are shown in Table 2.

[0071] Table 1

[0072]

[0073] Table 2

[0074]

[0075] From the test results, it can be seen that:

[0076] (1) From Examples 1-10 in Table 1 and Table 2, it can be seen that by adjusting the mass percentage of the glass composition, the high-refractive glass prepared has a density ≤3.6533 g / cm 3 , T550nm≥81.6, water resistance 1st level, acid resistance 1st level, expansion coefficient ≤9.73×10 -6 / ℃, refractive index nd≥1.9033, Abbe number Vd≥21.7, and nd≥(ρ-3.5)+1.769.

[0077] (2) From the comparison of Example 1 and Comparative Example 1 in Table 1 and Table 2, it can be seen that by further controlling 2.21≤C=(TiO2+Nb2O5) / (Na2O+K2O+CaO+BaO)≤3.18, if the component content exceeds this range, it will cause the density of the high-refractive glass to increase.

[0078] (3) By comparing example 1 and comparative example 2 in table 1 and table 2, it can be seen that the present application further controls 0.04≤A=(SiO2-Na2O-K2O) / (TiO2+Nb2O5)≤0.32, if the component content exceeds the range, it will result in the decrease of refractive index.

[0079] (4) By comparing example 1 and comparative example 3 in table 1 and table 2, it can be seen that the present application further controls 0.33≤B=(Na2O+K2O) / (CaO+BaO)≤4.57, if the component content exceeds the range, the high-refractive glass has poor water resistance and acid resistance.

[0080] In summary, the present application controls the mass percentage content of the glass composition, so that the high-refractive glass prepared has the density≤3.6533g / cm3, T550nm≥81.6, water resistance 1st level, acid resistance 1st level, expansion coefficient≤9.73×10-6 / ℃, refractive index nd≥1.9033, Abbe number Vd≥21.7, and nd≥(ρ-3.5)+1.769. 3 -6 In summary, the present application controls the mass percentage content of the glass composition, so that the high-refractive glass prepared has the density≤3.6533g / cm3, T550nm≥81.6, water resistance 1st level, acid resistance 1st level, expansion coefficient≤9.73×10-6 / ℃, refractive index nd≥1.9033, Abbe number Vd≥21.7, and nd≥(ρ-3.5)+1.769.

[0081] The applicant declares that the above description is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily thought of by those skilled in the art, and all fall within the protection scope and disclosure scope of the present application.​

Claims

1. A glass composition, characterized in that, The glass composition includes SiO2, TiO2, Nb2O5, Na2O, K2O, CaO, and BaO; Based on a total mass of 100wt% of the glass composition, the content of SiO2 is 18.5wt%-23wt%, the content of TiO2 is 25.5wt%-30wt%, the content of Nb2O5 is 27.5wt%-32wt%, the content of Na2O is 5wt%-10wt%, the content of K2O is 1wt%-6wt%, the content of CaO is 1wt%-8wt%, and the content of BaO is 2.5wt%-10wt%.

2. The glass composition according to claim 1, characterized in that, Based on a total mass of 100wt% of the glass composition, the content of SiO2 is 20wt%-22.5wt%, the content of TiO2 is 26wt%-28.5wt%, the content of Nb2O5 is 28wt%-30.5wt%, the content of Na2O is 5.5wt%-8wt%, the content of K2O is 1.5wt%-4wt%, the content of CaO is 4.5wt%-7wt%, and the content of BaO is 4.5wt%-9.5wt%.

3. The glass composition according to claim 1 or 2, characterized in that, The mass fractions of each component in the glass composition satisfy equation (1): 0.04≤A=(SiO2-Na2O-K2O) / (TiO2+Nb2O5)≤0.

32.

4. The glass composition according to any one of claims 1-3, characterized in that, The mass fractions of each component in the glass composition satisfy equation (2): 0.33≤B=(Na2O+K2O) / (CaO+BaO)≤4.

57.

5. The glass composition according to any one of claims 1-4, characterized in that, The mass fractions of each component in the glass composition satisfy equation (3): 2.21≤C=(TiO2+Nb2O5) / (Na2O+K2O+CaO+BaO)≤3.

18.

6. A high-refractive-index glass, characterized in that, The high-refractive-index glass is prepared using the glass composition according to any one of claims 1-5; The refractive index nd of the high-refractive glass satisfies nd≥(ρ-3.5)+1.769, where ρ represents density.

7. The high-refractive glass according to claim 6, characterized in that, The density of the high-refractive glass is ≤3.6533 g / cm³. 3 T550nm≥81.6, water resistance Grade 1, acid resistance Grade 1, expansion coefficient ≤9.73×10 -6 / ℃, refractive index nd≥1.9033, Abbe number Vd≥21.

7.

8. A method for preparing high-refractive-index glass as described in claim 6 or 7, characterized in that, The preparation method includes the following steps: The high-refractive-index glass is obtained by mixing the glass composition according to any one of claims 1-5 and the clarifier, heating and melting at 1250℃-1350℃ for 2h-8h, and then forming and annealing.

9. The preparation method according to claim 8, characterized in that, The clarifying agent includes NaNO3 and / or NaCl; Preferably, the clarifying agent accounts for 0.1wt%-0.3wt% of the total mass of the glass composition and the clarifying agent.

10. Use of the high-refractive glass as described in claim 6 or 7, characterized in that, The high-refractive-index glass is used in virtual reality and augmented reality devices, optical components, or optical lenses.

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