2results about How to "Low Abbe number" patented technology

This invention provides a polycarbonate resin with high refractive index, low Abbe number, and high resistance to damp heat. In one embodiment of this invention, a polycarbonate resin containing structural units represented by the following general formula (1) is provided. In formula (1), R1 and R2 independently represent hydrogen, fluorine, chlorine, bromine, iodine, alkyl with 1 to 6 carbon atoms, aryl with 6 to 36 carbon atoms in monocyclic or polycyclic form, heteroaryl with 5 to 36 ring atoms in monocyclic or polycyclic form, alkenyl with 2 to 6 carbon atoms, alkoxy with 1 to 6 carbon atoms, or aralkyl with 7 to 17 carbon atoms. Among the heteroaryl groups, one, two, three, or four ring atoms are selected from nitrogen, sulfur, and oxygen, and the other ring atoms are carbon. The aryl groups and heteroaryl groups in monocyclic or polycyclic forms have no substituents, or may have one or two R atoms selected from CN, CH3, OCH3, O-phenyl, O-naphthyl, S-phenyl, S-naphthyl, and halogens. a The group consists of a group of atoms, wherein R1 and R2 are not all hydrogen atoms; X is an alkylene group with 1 to 8 carbon atoms, a cycloalkylene group with 5 to 12 carbon atoms, or an arylene group with 6 to 20 carbon atoms; wherein the alkylene group and the cycloalkylene group can be substituted to have a benzene ring; a and b are integers from 1 to 10. #imgabs0#

This invention provides an optical glass with a refractive index of 1.76–1.83, an Abbe number of 21–27, and a high partial dispersion ratio. The optical glass, with its composition expressed as molar percentage, contains: P₂O₅: 20–40%; TiO₂: 10–30%; Nb₂O₅: 3–20%; WO₃: 4–20%; Na₂O: 5–26%; K₂O: 5–26%. Through reasonable composition design, the optical glass obtained by this invention has a high refractive index, a low Abbe number, and a high partial dispersion ratio, meeting the requirements for use in high-image-quality optical instruments.