The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 03, 1998
Filed:
Mar. 16, 1992
Richard R Ollmann, Jr, Woodbury, MN (US);
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Abstract
2-Methyl-4,4a-dihydro-3H-carbazolium salts that are useful as dye precursors and dyes derived from those precursors are disclosed. The salts are described by the formula ##STR1## wherein R.sup.1 represents an alkyl, aryl, sulfoalkyl, carboxyalkyl, sulfatoalkyl, alkoxyalkyl, acyloxyalkyl, dialkylarinoalkylene, cycloaminoalkylene, acyl, or alkenyl group having from 1 to 18 carbon atoms; R.sup.2 represents an alkyl group having up to 18 carbon atoms; R.sup.3 represents hydrogen or an alkyl group having from 1 to 18 carbon atoms; R.sup.4 represents hydrogen or an alkyl group having from 1 to 18 carbon atoms; R.sup.5 represents hydrogen, nitro, carboxyl, sulfo, hydroxy, halogen, phospho, or an alkoxy, thioalkoxy, oxyalkyl, acyl, alkyl, aryl, or amino group having up to 18 carbon atoms; wherein any two groups R.sup.5, or R.sup.4 and a group R.sup.5, or R.sup.1 and R.sup.4 may together form a substituted or unsubstituted aryl, heteroaryl, aliphatic, or heteroaliphatic ring; X represents an anion; and a and b represent positive integers such that a equals b. The salts have a partially saturated ring system that rigidifies the chromophore in the precursor and in dyes derived from it. The rigidified chromophores have narrowed absorption bands relative to corresponding non-rigid chromophores. Dyes prepared from the dye precursors of the invention typically have good solubility in non-polar solvents.