US3905949A — Stilbene azo lithium salt dyes

Claim 1

Independent Claim 103 words

STILBENE AZO DYE, AS LITHIUM SALT OR MIXED LITHIUM AND SODIUM SALTS WHEREIN THE RATIO OF LITHIUM TO SODIUM IS AT LEAST 1:2 PREPARED BY CONDENSING A MEMBER OF THE GROUP CONSISTING OF THE LITHIUM SALTS OF 5-NITRO-O-TOLUENSULFONIC ACID AND THE DILITHIUM, MONOLITHIUM MONOSODIUM, AND DISODIUM SALTS OF 4,4''-DINITO-2,2''-STILBENEDISULFONIC ACID, IN AN AQUEOUS ALKALINE REACTION MEDIUM, AT A TEMPERATURE OF FROM ABOUT 20*C. TO THE BOILING TEMPERATURE OF THE REACTION MEDIUM, IN THE PRESENCE OF SULFICIENT IONIC LITHIUM TO PROVIDE A RATIO OF LITHIUM TO SODIUM IN THE DYE OF AT LEAST 1:2, UNTIL FORMATION OF SAID STILBENE AZO DYE IS SUBSTANTIALLY COMPLETE.

Claim 2

Dependent Claim 103 words

STILBENE AZO DYE, AS LITHIUM SALT OR MIXED LITHIUM AND SODIUM SALTS WHEREIN THE RATIO OF LITHIUM TO SODIUM IS AT LEAST 1:2 PREPARED BY CONDENSING A MEMBER OF THE GROUP CONSISTING OF THE LITHIUM SALTS OF 5-NITRO-O-TOLUENSULFONIC ACID AND THE DILITHIUM, MONOLITHIUM MONOSODIUM, AND DISODIUM SALTS OF 4,4''-DINITO-2,2''-STILBENEDISULFONIC ACID, IN AN AQUEOUS ALKALINE REACTION MEDIUM, AT A TEMPERATURE OF FROM ABOUT 20*C. TO THE BOILING TEMPERATURE OF THE REACTION MEDIUM, IN THE PRESENCE OF SULFICIENT IONIC LITHIUM TO PROVIDE A RATIO OF LITHIUM TO SODIUM IN THE DYE OF AT LEAST 1:2, UNTIL FORMATION OF SAID STILBENE AZO DYE IS SUBSTANTIALLY COMPLETE.

Claim 3

Dependent Claim 91 words

Stilbene azo dye of claim 1, prepared by condensing the lithium salt of 5-nitro-o-toluenesulfonic acid, in an aqueous reaction medium, in the presence of at least about 0.2 mole, per mole of lithium salt, of a base selected from lithium hydroxide and sodium hydroxide, at a temperature of from about 20*C. to the boiling temperature of the reaction medium, in the presence of sufficient ionic lithium to provide a ratio of lithium to sodium in the dye of at least 1:2, until formation of said stilbene azo dye is substantially complete.

Claim 4

Dependent Claim 121 words

Stilbene azo dye of claim 1, prepared by condensing, in admixture at a weight ratio of 70:30 to 90:10, the lithium salt of 5-nitro-o-toluenesulfonic acid and a member of the group consisting of the dilithium, monolithium monosodium, and disodium salts of 4,4''-dinitro-2,2''-stilbenedisulfonic acid, in an aqueous reaction medium, in the presence of at least about 0.2 mole, per mole of salts in the mixture, of a base selected from lithium hydroxide and sodium hydroxide, at a temperature of from about 20*C. to the boiling temperature of the reaction medium, in the presence of sufficient ionic lithium to provide a ratio of lithium to sodium in the dye of at least 1:2, until formation of said stilbene azo dye is substantially complete.

Claim 5

Dependent Claim 101 words

Stilbene azo dye of claim 1, prepared by condensing a member of the group consisting of the dilithium and monolithium monosodium salts of 4,4''-dinitro-2,2''-stilbenedisulfonic acid, in an aqueous reaction medium, in the presence of at least about 0.2 mole, per mole of stilbene salt, of a base selected from lithium hydroxide and sodium hydroxide, at a temperature of from about 20*C. to the boiling temperature of the reaction medium, in the presence of sufficient ionic lithium to provide a ratio of lithium to sodium in the dye of at least 1:2, until formation of said stilbene azo dye is substantially complete.

Claim 6

Dependent Claim 103 words

Stilbene azo dye, as lithium salt or mixed lithium and sodium salts wherein the ratio of lithium to sodium is at least 1:2, prepared by condensing a member of the group consisting of the lithium salt of 5-nitro-o-toluenesulfonic acid and the dilithium, monolithium monosodium, and disodium salts of 4,4''-dinitro-2,2''-stilbenedisulfonic acid, in an aqueous alkaline reaction medium, at a temperature of from about 20*C. to the boiling temperature of the reaction medium, in the presence of sufficient ionic lithium to provide a ratio of lithium to sodium in the dye of at least 1:2, and thereafter reacting the condensation product with a reducing agent.

Claim 7

Dependent Claim 103 words

Stilbene azo dye, as lithium salt or mixed lithium and sodium salts wherein the ratio of lithium to sodium is at least 1:2, prepared by condensing a member of the group consisting of the lithium salt of 5-nitro-o-toluenesulfonic acid and the dilithium, monolithium monosodium, and disodium salts of 4,4''-dinitro-2,2''-stilbenedisulfonic acid, in an aqueous alkaline reaction medium, at a temperature of from about 20*C. to the boiling temperature of the reaction medium, in the presence of sufficient ionic lithium to provide a ratio of lithium to sodium in the dye of at least 1:2, and thereafter reacting the condensation product with a reducing agent.

Claim 8

Dependent Claim 90 words

Stilbene azo dye of claim 5, prepared by condensing the lithium salt of 5-nitro-o-toluenesulfonic acid, in an aqueous reaction medium, in the presence of at least 0.2 mole, per mole of lithium salt, of a base selected from lithium hydroxide and sodium hydroxide, at a temperature of from about 20*C. to the boiling temperature of the reaction medium, in the presence of sufficient ionic lithium to provide a ratio of lithium to sodium in the dye of at least 1:2, and thereafter reacting the condensation product with a reducing agent.

Claim 9

Dependent Claim 122 words

Stilbene azo dye of claim 5, prepared by condensing, in admixture at a weight ratio of 70:30 to 90:10, the lithium salt of 5-nitro-o-toluenesulfonic acid and a member of the group consisting of the dilithium, monolithium monosodium and disodium salts of 4,4''-dinitro-2,2''-stilbenedisulfonic acid, in an aqueous reaction medium, in the presence of at least about 0.2 mole, per mole of salts in the mixture, of a base selected from lithium hydroxide and sodium hydroxide, at a temperature of from about 20*C. to the boiling temperature of the reaction medium, in the presence of sufficient ionic lithium to provide a ratio of lithium to sodium in the dye of at least 1:2, and thereafter reacting the condensation product with a reducing agent selected.

Claim 10

Dependent Claim 106 words

In a process for preparing stilbene azo dye by means of an alkaline condensation of a salt of 5-nitro-o-toluenesulfonic acid or of 4,4''-dinitro-2,2''Stilbenedisulfonic acid, the improvement which comprises condensing a member of the group consisting of the lithium salt of 5-nitro-o-toluenesulfonic acid and the dilithium, monolithium monosodium, and disodium salts of 4,4''-dinitro-2,2''-stilbenedisulfonic acid, in an aqueous alkaline reaction medium, at a temperature of from about 20*C. to the boiling temperature of the reaction medium, in the presence of sufficient ionic lithium to provide a ratio of lithium tO sodium in the dye of at least 1:2, until formation of said stilbene azo dye is substantially complete.

Claim 11

Dependent Claim 106 words

In a process for preparing stilbene azo dye by means of an alkaline condensation of a salt of 5-nitro-o-toluenesulfonic acid or of 4,4''-dinitro-2,2''Stilbenedisulfonic acid, the improvement which comprises condensing a member of the group consisting of the lithium salt of 5-nitro-o-toluenesulfonic acid and the dilithium, monolithium monosodium, and disodium salts of 4,4''-dinitro-2,2''-stilbenedisulfonic acid, in an aqueous alkaline reaction medium, at a temperature of from about 20*C. to the boiling temperature of the reaction medium, in the presence of sufficient ionic lithium to provide a ratio of lithium tO sodium in the dye of at least 1:2, until formation of said stilbene azo dye is substantially complete.

Claim 12

Dependent Claim 18 words

The process of claim 8 wherein the product of the condensation reaction is reacted with a reducing agent.

Claim 13

Dependent Claim 32 words

The process of claim 8 wherein the alkaline medium is produced by means of 0.2 mole, per mole of salt being condensed, of a base selected from lithium hydroxide and sodium hydroxide.

Claim 14

Dependent Claim 45 words

The process for the preparation of a solubilized stilbene dye which comprises heating 2-methyl-5-nitrobenzenesulfonic acid in aqueous medium at a temperature of about 40* to about 100*C. and in the presence of at least a stoichiometric amount of lithium hydroxide; said 2-methyl-5-nitrobenzene-sulfonic acid being pure.

Claim 15

Dependent Claim 45 words

The process for the preparation of a solubilized stilbene dye which comprises heating 2-methyl-5-nitrobenzenesulfonic acid in aqueous medium at a temperature of about 40* to about 100*C. and in the presence of at least a stoichiometric amount of lithium hydroxide; said 2-methyl-5-nitrobenzene-sulfonic acid being pure.

Claim 16

Dependent Claim 14 words

A process according to claim 11 in which the lithium hydroxide is added incrementally.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-09-15	1979-03-17	1979-09-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-09-15	1983-03-17	1983-09-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-09-15	1987-03-17	1987-09-16	$7700.00	Window Closed / Lapsed

Stilbene azo lithium salt dyes

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