发明授权
US4785088A Pigments and their preparation 失效
颜料及其制备

Pigments and their preparation
摘要:
Pigments of the general formulaF.multidot.Het (I).where F is the cation of a cationic dye which has an absorption maximum at >700 nm and may or may not contain anionic groups and Het is an anion of a heteropolyacid based on tungsten, molybdenum, vanadium or a mixture of these with phosphorus, silicon, cobalt, aluminum, manganese, chromium, nickel or a mixture of these or a copper(I)-hexacyanoferrate(II) anion, are superior to the known IR dyes in terms of thermal stability and photostability, and give optical recording media having superior properties, such as a high signal/noise ratio.
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