Azo dyes and a method of making a hydrocarbon using an azo dye
AssigneeBASF SE
InventorsGeorg Zeidler, Gerhard Scholz, Claudia Krah, Karin Heidrun Beck, Udo Mayer
Life of this patent
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Abstract
Azo dyes of the formula ##STR1## where the ring A may be benzofused, n is 0 or 1, and R.sup.1 -R.sup.8 are as defined, as pH-dependent markers for hydrocarbons, hydrocarbons containing the above-mentioned azo dyes, and a method for detecting these azo dyes in hydrocarbons.
Claims2
A method of marking a hydrocarbon, comprising adding to a hydrocarbon an azo dye of the formula Ib ##STR25## where R.sup.1 is hydrogen or C.sub.1 -C.sub.15 -alkyl,
- R.sup.2 is C.sub.1 -C.sub.15 -alkyl and
- X.sup.3 is hydrogen, C.sub.1 -C.sub.15 -alkyl which is uninterrupted or interrupted by from 1 to 4 ether oxygen atoms or is a radical of the formula LNX.sup.1 X.sup.2, where L is C.sub.2 -C.sub.8 -alkylene and X.sup.1 and X.sup.2 independently of one another are each C.sub.1 -C.sub.6 -alkyl or, together with the nitrogen atom linking them, form a 5-membered or 6-membered saturated heterocyclic radical which does or does not furthermore contain an oxygen atom in the ring.
A hydrocarbon containing one or more azo dyes, as pH-dependent markers, of the formula Ib ##STR26## where R.sup.1 is hydrogen or C.sub.1 -C.sub.15 -alkyl,
- R.sup.2 is C.sub.1 -C.sub.15 -alkyl and
- X.sup.3 is hydrogen, C.sub.1 -C.sub.15 -alkyl which is uninterrupted or interrupted by from 1 to 4 ether oxygen atoms or is a radical of the formula LNX.sup.1 X.sup.2, where L is C.sub.2 -C.sup.8 -alkylene and X.sup.1 and X.sup.2 independently of one another are each C.sub.1 -C.sub.6 -alkyl or, together with the nitrogen atoms linking them, form a 5-membered or 6-membered saturated heterocyclic radical which does or does not furthermore contain an oxygen atom in the ring.
Dependencies are inferred from the claim text.