Heavy-corona optical glass

Abstract

The invention provides heavy-corona optical glass with high weather resistance and low cost. The refraction rate of the heavy-corona optical glass is 1.56-1.62, and abbe is 57-64. The heavy-corona optical glass comprises, by mole percent, 45-65% of SiO2, 10-25% of B2O3, 3-10% of Al2O3 and 15-30% of BaO. The viscosity at the temperature of 1400 DEG C is lower than 50dPaS. The heavy-corona optical glass has the advantages that through reasonable component proportioning, the glass has high weather resistance and good technological performance besides low cost, and the viscosity at the temperature of 1400 DEG C is lower than 50dPaS; the weather resistance reaches three levels or above, and market demands for low-cost high-performance optical glass can be met sufficiently.

Description

technical field [0001] The invention relates to a double-crown optical glass, in particular to a double-crown optical glass with a refractive index of 1.56-1.62 and an Abbe of 57-64, which has low cost and good weather resistance and process performance. Background technique [0002] Optical glass with a refractive index of 1.56-1.62 and an Abbe number of 57-64 belongs to double crown optical glass, which is widely used in imaging lenses, telescopes, gun sights and other optical systems, and is used in a large amount in the field of optical glass base material. [0003] In recent years, with the increasingly fierce competition in terminal markets such as cameras and telescopes, terminal manufacturers hope to obtain optical glass with lower prices and better performance to meet the needs of market competition. The cost of optical glass is mainly composed of raw material cost, production cost and subsequent processing cost. Therefore, there are three main ways to reduce the ...

AI Technical Summary

Problems solved by technology

[0006] 3) Due to the fact that double crown glass with a refractive index and Abbe number within the above range usually has extremely poor weather resistance, and its weather resistance is usually lower than level 3, it is prone to defects in the cleaning process after polishing, and special protection procedures need to be added and A low-humidity storage environment is required, which increases the process, difficulty and cost

[0007] US3510325A discloses an optically similar glass containing 42-46% of B 2 o 3 , 20-25% CaO, 14-16% La 2 o 3 , but such a high content of B 2 o 3 It will cause poor weather resistance and cost increase, while 14-16% La 2 o 3 It will reduce the acid resistance of glass, increase the cost of raw materials, and increase the consumption of rare earth resources

[0008] The glass disclosed in US005744409A contains 7-12% Li 2 O, too much Li 2 O will cause a rapid decline in the weather resistance and devitrification resistance of the glass

When producing thick-gauge products, especially when the thickness exceeds 40mm, the speed of the inside of the glass becoming solid is much slower than the speed of the glass surface becoming solid, so it is easy to produce streaks in the middle of the glass and be scrapped

In addition, containing more Li 2 O glass is easy to contaminate the mold when used for precision pressing

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