GB2186585A - Reactive azo dyes - Google Patents

Abstract

Reactive azo dyes have the formula: <IMAGE> where R<1> is C1-C4-alkyl, C1-C4-alkoxy, chlorine or bromine, R<2> is substituted or unsubstituted C2-C4-alkyl and R<3> is hydrogen, C1-C4-alkyl C1-C4-alkoxy, chlorine or bromine. They, and their salts, can be used for dyeing cellulose-containing material. Liquid dye formulations which contain from 5 to 35% by weight of these compounds are resistant to crystallization.

Description

SPECIFICATION Reactive azo dyes The present invention relates to novel reactive monoazo dyes ofthe monochlorotriazine series and to liquid dye formulations which contain the novel dyes.

GB-A-834,304 describes reactive monoazo dyes of the monochlorotriazine series which have an N-methylanilino radical on the triazine radical.

The present invention provides novel reactive azo dyes oftheformula I

where R1 is C1-C4-alkyl, C1-C4-alkoxy, chlorine or bromine, R2 is C2-C4-a I kyl which may be substituted by hydroxyl or C1-C4-alkoxy, and R3 is hydrogen, C-C4-alkyl, C1-C4-alkoxy, chlorine or bromine, and salts of these compounds.

In the formula I, R1 is for example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, chlorine or bromine.

R2 is for example ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or sec-butyl. The C2-C4 alkyl group may also be substituted, for example by hydroxyl or C1-C4 -alkoxy. Examples are: 2-hydroxyethyl, 2-hyd roxypropyl, 3-hydroxypropyl, 2-hydroxybutyl, 2-methoxyethyl, 2-ethoxyethyl, 2-methoxypropyl and 2-ethoxypropyl.

R3isforexample hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, chlorine or bromine.

Examples of salts ofthe reactive azo dyes oftheformula I are alkali metal salts, in particularthelithium, sodium or potassium salts, alkaline earth metal salts, in particularthe magnesium salts, and tetraalkylammonium salts.

Preference is given to reactive azo dyes of the formula II

where R1 is methyl, ethyl, methoxy, ethoxy or chlorine and R2 is C1-C4-alkyl, and their salts.

Particular preference is given to reactive azo dyes of the formula II where R1 is methyl, methoxy, ethoxy or chlorine para to the azo group and R2 is ethyl, and theirsalts.

The dyes according to the invention can be obtained in a conventional manner. For example, substituted anilinesulfonic acids are diazotized and coupled onto condensation products which are obtained by reacting 1 -hydrnxy-8-aminonaphthalene-3,6(or 4,6)-disulfonic acid with cyanuric chloride and the particular aniline derivative.

Suitable substituted anilinesulfonic acids are for example 2-amino-5-methylbenzenesulfonic acid, 3-amino-6-methylbenzenesulfonic acid, 3-amino-4-methyl benzenesulfonic acid, 4-amino-5-methylbenzenesulfonic acid, 2-amino-5-ethylbenzenesulfonic acid, 3-amino-6-ethylbenzenesulfonic acid, 3-amino-4-ethyl benzenesulfonic acid, 4-amino-5-ethylbenzenesulfonic acid, 2-amino-5-methoxybenzenesulfonic acid, 3-amino-4-methoxybenzenesulfonic acid, 3-amino-6-methoxybenzenesulfonic acid, 2-amino-5-ethoxybenzenesu Ifonic acid, 3-amino-6-ethoxybenzenesulfonic acid, 2-amino-5-chlorobenzenesulfonic acid, 4-amino-5-chlorobenzenesulfonic acid, 3-amino-4-chlornbenzenesulfonic acid, 3-amino-6-chlorobenzenesulfonic acid, 2-amino-4-chlorobenzenesulfonic acid, 2-amino-5-bromobenzenesulfonic acid or 4-amino-5-bromobenzenesulfonic acid.

Suitable aniline derivatives for the condensation reaction are for example N-ethylaniline, N-propylaniline, N-isopropylaniline, N-butylaniline, N-isobutylaniline, N-sec-butylaniline, N-ethyl-o-, -m- or-p-toluidine, N-propyl-o-, -m- or -p-toluidine, N-butyl-o-, -m- or -p-toluidine, N-ethyl-o-, -m- or-p-chloroaniline, N-propyl-o-, -m- or-p-chloroaniline, N-butyl-o-, -m- or-p-chloroaniline, N-ethyl-o-, -m-or-p-anisidine, N-ethyl-o-, -m- or-p-phenetidine, N-(2-hydroxyethyl)aniline, N-(2-hydroxypropyl)-aniline, N-(2-hydroxybutyl)anil ine or N-(2-methoxyethyl)-aniline.

The novel dyes are highly suitable for dyeing cellulose-containing materials, in particular cotton. Dyeings in yellowish to bluish red shades are obtained. A particular advantage of the products according to the invention is their excellentwatersolubility in the salt form. They are highly suitable for preparing non-crystallizing liquid dye formulations.

These liquid dye formulations according to the invention contain from 5 to 35% by weight, preferablyfrom 16to 24% by weight, of a reactive azo dye of the formula I. They can also contain conventional assistants such as buffer substances, water-retaining agents and disinfectants or hydrotropic agents.

The following Examples illustrate the invention in more detail. The parts and percentages are byweight.

Example 1 To an aqueous suspension of 55 parts of a secondary condensation product of 1 -amino-8-hydroxynaphthalene-3,6-disulfonic acid, cyanuric chloride and N-ethylanilinewas added at 0 - 5 C the azo suspension, in hydrochloric acid solution, of 18.7 parts of 2-amino-5-methylbenzenesuifonic acid, and the mixturewas broughtto pH 5.5 with sodium carbonate. After 6 hours of stirring at pH 5.5 the coupling was complete. The dye was salted out at room temperature from the neutral solution by adding 200 parts of sodium chloride, filtered off and dried.

The dye of the formula

dyes cotton in bright bluish red shades having generally good fastness properties.

Example2 20.5 parts of 2-amino-5-methoxybenzenesulfonic acid wee diazotized in hydrochloric acid solution, and the diazo suspension was added at O - 5"C to an aqueous suspension of 55 parts ofthe secondary condensation product of 1 -amino-8-hydroxynaphthalene-3,6-disulfonic acid, cyanuric chloride and N-ethylaniline. The mixture was then broughtto pH 5.5 by adding sodium carbonate and maintained atthat pH for6 hours until the coupling had ended. The dye of the formula

was precipitated with 200 parts of sodium chloride, filtered off and dried. On cotton it produces strongly bluish red dyeings having good fastness properties.

The method of Examples 1 and 2 can also be used to obtain the dyes of the formula

listed in Table 1.

TABLE 1

Example Hue on No. D 3H Z cotton S0H 3 c1 -N red C2H5 SO3H bluish 4 C2Hs Fizzbluish C2H5 H0S bluish 5 H3CO--J3- -N- d i bluish C2Hs 6 - red 6 '-' I Cl c211s H0S N- I bluish 7 czHsfl#'' C2H5 red SO3H red bluish 8 H3C'' C4H9(n) red 1 9 bluish 9 sJc C12Hs red TABLE 1 (continued)

Example Hue on No. D Z cotton '03H CH3 - -N bluish 10 I'-' C2H5 red S02H 11 H3C CH3 bluish cziis red S03H H3C bluish 12 C2H5 4 Ni red C3H7(n) S03H H3C bluish 13 C2Hs 4 ~ H 3 red C4Hg(n) S03H H bluish 14 Ha --N red 4 Hginl S03H H3C HJC4C C4Hg(nl red C?'3 16 H03S 4 3 -N- red C2H5 TABLE 1 (continued)

Example Hue on No. D z cotton ICH3 17 HO3S c2Hs red red 18 HO3 Sb NC3 red C2H5 19 C1 red -N H0sS C2H5 red S03H 20 C1-d C4Hs(n) The same method also gives the dyes of the formula

listed in Table 2.

TABLE 2

Example Hue on No. D Z cotton SO3H 21 - I- red C2H5 SO2H 22 3 bluish - c2Hs red I red C2Hg S03H I red C3K(n) CH-r(n) bLuish 24 HCO-- I red C2H5 SO3H 25 C1 b 3H ss4 red C4H9 (n) SO3H cli3 26 -N red C4Hg Example 27 30 parts of a salt-containing, water-moist press-cake of the dye of the following structure

Na-salt having a pure dye content of 25% were dissolved in 70 parts of water (temperature: 20 - 250C). The dye solution was then subjected at 20 - 25"C and pH 8.0 to electrodialysis until the residual chloride contentwas below 0.1%.

The demineralized dye solution had a pure dye content of 8.5% and was standardized to pH 7.5 by adding 2% of Na2HPO4 (based on pure dye).

By contentrating with a rotary evaporatorthe pure dye content of the solution was increased to 24%.

The dye solution obtained has a long shelf life, being free of dye precipitate after standing for 6weeks.

Example 28 40 parts of a salt-containg, water-moist press-cake ofthe dye ofthe following structure

Na-salt having a pure dye content of 34% were dissolved in 60 parts of water (temperature: 40"C). The dye solution was then subjected at 400C and pH 8.0to electrodialysis until the residual chloride content was below 0.1%.

The demineralized dye solution had a pure dye content of 1 6% and a pH of 8.0.

The dye solution obtained has a long shelf life, being free of dye precipitate afterstanding for6weeks.

Example 29 40 parts of a salt-containing, water-moist press-cake of the dye of the following structure

Li-salt having a pure dye content of 40% were dissolved in 60 parts of water (temperature: 45 - 50"C), and the solution was broughtto pH 7.5 with lithium hydroxide. The dye solution has a pure dye content of 16%.

The dye solution obtained had a long shelf life, being free of dye precipitate after standing for 6weeks.

Claims (5)

1. A reactive azo dye ofthe formula I

where R1 is C1-C4-alkyl, C1-C4-alkoxy, chlorine or bromine, R2 is C2-C4-alkyl which may be substituted by hydroxyl orC1-C4-alkoxy and R3 is hydrogen, C1-C4-alkyl, C1-C4-alkoxy, chlorine or bromine or a saltthereof.

2. A reactive azo dye as claimed in claim 1, of the formula II

where R1 is methyl, ethyl, methoxy, ethoxy or chlorine and R2 is C2-C4-alkyl, or a sa It thereof.

3. Acompound as claimed in claim 1 and mentioned in any ofthe foregoing Examples.

4. A liquid dye formulation which contains 5 to 35% by weight of a compound as claimed in any ofclaims 1 to 3.

5. Cellulose containing material which has been dyed with a compound as claimed in any of claims 1 to 3.