Optical glass for precise compression molding

Abstract

The invention provides optical glass for precision compression moulding forming, wherein the nd is between 1.63 and 1.75, and the vd is between 27 and 37. The optical glass does not contain compositions with high price such as Nb2O5 and Ta2O5, and the Tg is less than 520 DEG C. The optical glass for precision compression moulding forming comprises the following compositions by molar percentage: 40 to 60 percent of SiO2, 15 to 30 percent of TiO2, 10.5 to 30 percent of Li2O+Na2O+K2O+Cs2O, 0 to 8 percent of MgO+CaO+SrO+BaO, 0 to 2 percent of Ta2O5+ WO3+Nb3O5, 0 to 1 percent of Al2O3, 0 to 1 percent of ZrO2, 0 to 5 percnet of B2O3, 0 to 2 percent of La2O3, and 0 to 0.1 percent of clarifying agent. The optical glass is suitable for precise compression molding forming, has superior devitrification resistance, good fusing performance, forming performance and processability, and crystallization stability for realizing continuous fusing. An optical element made of the optical glass is suitable for the technical fields such as imaging system, medical technology, digital projection, photoetching technique and wafer / chip.

Description

technical field [0001] The present invention relates to a kind of optical glass, relate in particular to a kind of refractive index (n d ) is 1.63-1.75, Abbe number (v d ) is 27-37, and the glass transition temperature (Tg) is lower than 520 ℃ optical glass for precision molding. Background technique [0002] In recent years, with the development of the optoelectronic industry, the requirements for miniaturization, light weight, and high performance have been put forward for optical equipment. In order to reduce the number of lenses that constitute the optical system in optical equipment, more and more aspheric surfaces are used in optical design. lens. The processing methods of aspheric lenses are divided into traditional methods and precision molding methods. The so-called traditional method is to first cut the glass material into blocks of a certain size and shape, heat and press the blocks into shapes of certain shapes, and then Grinding and polishing the molded mater...

AI Technical Summary

Problems solved by technology

[0004] The optical glass used for precision molding requires various optical constants and Abbe numbers. For optical glass with a refractive index of 1.63-1.75 and an Abbe number of 27-37, adding lead oxide to the glass can significantly reduce the glass Transition temperature, such as JP-A-62-3103 describes the optical glass containing PbO, but the environmental load of PbO is very large, in order to protect the environment, in the field of optical glass, lead-containing glass has gradually been replaced by environmentally friendly optical glass without PbO components In addition, during precision molding, PbO undergoes a reduction reaction in the molding die, which is easy to damage the mold material

[0005] CN1396132A describes SiO with a refractive index of 1.65-1.80 and an Abbe number of 21-33 2 -Al 2 o 3 -TiO 2 -RO (RO represents alkaline earth metal oxides such as MgO, CaO, BaO) optical glass, the transition temperature of the glass is relatively high, and the glass contains 5-17% (wt%) of Nb 2 o 5 , Nb 2 o 5 The raw material is expensive, and as an essential component, it greatly increases the cost of glass; CN1448355A describes SiO with a refractive index of 1.55-1.67 and an Abbe number of 30-45 2 -B 2 o 3 -TiO 2 -BaO-K 2 O-ZnO optical glass, in order to improve the chemical stability of glass, this optical glass contains 0-5% (wt%) ZnO, ZnO component forms residue due to the grinding and polishing of glass, and dissolves in the form of zinc ion In water, if water containing zinc ions is discharged without proper treatment, it will cause water pollution and is not conducive to environmental protection

[0006] JP-10-130033, JP-10-265238, US6255240 and US6703333 describe SiO 2 -B 2 o 3 -ZrO 2 -Nb 2 o 5 It is an optical glass, which contains more Nb 2 o 5 and ZrO 2 , the glass cost is high due to the Nb 2 o 5 and ZrO 2 If the content is too high, the glass is easy to devitrify, and the production of the glass is difficult. The Tg of the optical glass described in US6703333 can be as low as 400°C, but the content of alkali metal oxide in the glass is high, and the chemical stability of the glass is poor

[0007] Ta 2 o 5 Replace part of Nb 2 o 5 , with Nb 2 o 5 Compared with the price of raw materials, Ta 2 o 5 The price of raw materials is higher, so the production cost of glass is high

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