Optical Glass Composition for Precision Molding
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Solution Overview
Problem
Current high-refraction low-dispersion optical glasses with refractive index of 1.76-1.80 and Abbe number of 47-51 face challenges in achieving low glass transition temperature (Tg) while maintaining excellent transmittance, often requiring expensive Ta2O5 and SnO2, which increase material costs and affect processing quality.
Innovation Solution
A glass composition comprising specific weight percentages of SiO2, B2O3, La2O3, Gd2O3, ZrO2, ZnO, Ta2O5, Nb2O5, Li2O, Y2O3, and additional oxides, optimized to reduce Ta2O5 content, achieve low Tg, and enhance transmittance without using SnO2, thereby improving cost-effectiveness and precision molding capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Ta2O5 and SnO2 are used to achieve high refractive index and low dispersion, then optical performance is improved, but material cost increases and transmittance decreases
Solution Approach 1:
The patent changes the chemical composition parameters by replacing expensive Ta2O5 and SnO2 with a combination of La2O3, Gd2O3, ZrO2, and Nb2O5. This substitution maintains the refractive index (1.76-1.80) and Abbe number (47-51) while reducing material cost and improving transmittance by eliminating the pigmentation caused by SnO2
Solution Approach 2:
The patent uses more economically viable oxide materials (La2O3, Gd2O3, ZrO2, Nb2O5) instead of expensive Ta2O5 and problematic SnO2. These alternative materials achieve the same optical performance at lower cost without the transmittance degradation associated with SnO2
2Quantity of substance
If Ta2O5 content is reduced to lower material cost, then product economy is improved, but achieving low Tg and excellent transmittance becomes difficult
Solution Approach 1:
The patent creates a composite glass system combining multiple oxide components (La2O3, Gd2O3, ZrO2, Nb2O5, B2O3, SiO2) that work synergistically. This composite approach achieves low Tg (<625°C) and excellent transmittance without relying on Ta2O5, by distributing the functional requirements across different materials in the composition
3Reliability
If SnO2 is added to achieve high refractive index, then optical constants are improved, but processing performance deteriorates due to impurity formation and pigmentation
Solution Approach 1:
The patent extracts SnO2 from the glass composition entirely, removing the source of processing problems (impurity formation and pigmentation). The optical constants are maintained through alternative materials (La2O3, Gd2O3, ZrO2, Nb2O5) that do not exhibit the same processing difficulties as SnO2
Data Source
AI summary
The invention provides a high-refraction low-dispersion optical glass with refractive index of 1.76-1.80 and Abbe number of 47-51. The optical glass, comprising the following components by weight percentage: 0-3% of SiO2; 25-40% of B2O3; 20-40% of La2O3; 12-25% of Gd2O3; 6.5-15% of ZrO2; greater than 10% but less than or equal to 20% of ZnO; 0-5% of Ta2O5; 0-5% of Nb2O5; 0-10% of Li2O; less than 0.45 of (Ta2O5+Nb2O5)/(ZnO+Li2O); 0-10% of Y2O3; and below 625° C. of glass transition temperature Tg. With reasonable component ratio, the high-refraction low-dispersion optical glass favorable to precision molding with excellent transmittance can be easily enabled while realizing the required optical constant of the glass of the present invention.