Pigments and their preparation
AssigneeBASF SE
InventorsHelmut Flohr, Joachim Jesse, Bernhard Albert, Peter Neumann
Life of this patent
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Abstract
Pigments of the general formula F.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.
Claims11
A pigment of the formula:
- F Het, wherein F is a cation of the structure (I) or (II):
- ##STR65## wherein Pc is a (p+s+v) valent radical of a metal-free phthalocyanine or of a metal phthalocyanine which contains VO, TiO, Pb, Sn, Cu, Ni or Mn as the central metal atom and in which the methylene group is bonded to a carbon atom of the imidazole ring, p is 1 to 4, s is 0 or 1, v is 0, 1, 2, 3 or 4, Pc' is a w valent radical of a metal-free phthalocyanine or of a metal phthalocyanine which contains VO, TiO, Pb, Sn, Cu, Ni or Mn as the central metal, Hal is bromine, chlorine or fluorine, R.sup.7 is C.sub.1 -C.sub.4 -alkyl, C.sub.2 -C.sub.4 -hydroxyalkyl or C.sub.2 -C.sub.4 -aminoalkyl and w is 1, 2, 3 or 4, said cation having 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 thereof with phosphorus, silicon, cobalt, aluminum, manganese, chromium, nickel or a mixture thereof or a copper(I)-hexacyano ferrate(II) anion [Cu.sub.3 Fe(CN).sub.6 ].sup..crclbar., the pigment being obtained by laking the phthalocyanine based cation with the heteropolyacid.
Dependencies are inferred from the claim text.