GB2186295A

GB2186295A - Aqueous reactive dye preparations

Info

Publication number: GB2186295A
Application number: GB08702579A
Authority: GB
Inventors: Wolfgang Groebke; Heinz Ochsner; Hermann Gilgen
Original assignee: Sandoz AG
Current assignee: Sandoz AG
Priority date: 1986-02-08
Filing date: 1987-02-05
Publication date: 1987-08-12
Anticipated expiration: 2007-02-05
Also published as: FR2594129A1; CH669204A5; GB2186295B; IT1216789B; IT8747616A0; GB8702579D0; FR2594129B1; JPS62185760A

Abstract

An aqueous preparation comprises: 10-55% of sparingly soluble reactive dye; 4-25% of a dispersing agent; 0-4 of a buffer and/or salt (preferably the salt is NaCl and/or Na2 SO4) and 25-86% of water; Such a preparation is stable to storage over at least 6 months, and may be used to dye nitrogen- and hydroxy-containing, especially cellulosic, substrates.

Description

SPECIFICATION Improvements in or relating to organic compounds The invention relates to aqueous dispersions of reactive dyes that are stable to storage over at least 6 months.

In recent years, with increased automation and cost and energy saving drives, higher standards in dye preparations have become necessary.

To this end, in the field of reactive dyes, easily soluble aqueous concentrates have been developed. The problem with such concentrates is that they have a poor stability or tend to thicken on storage.

To alleviate this problem there is provided aqueous preparation comprising: 10-55% of a sparingly soluble reactive dye; 4-25% of a dispersing agent; 0-4% of a buffer and/or salt (preferably the salt is NaCI and/or Na2SO4) and 25-86% of water; the percentages being based on the total weight of the dispersion.

For the avoidance of doubt, the NaCI and Na2SO4 present in the preparations of the Examples is present in the presscake and is associated with the reactive dye of the Example. It is not added as an additional component. It is preferable to keep the salt content as low as possible. For the avoidance of doubt the 0 to 4% range for buffer and/or salt does not include salt present as a dispersing agent.

Preferably, a preparation according to the invention is homogenised by milling to produce an average particle size of less than 5um.

Preferably sparingly soluble reactive dyes have a solubility between 50 and 250g/l, more preferably between 50 and 150gel in water.

Preferably the reactive dye in a preparation according to the invention is a "cold dyeing reactive dye" and such "cold dyeing reactive dyes" are well known to the man skilled in the art. More preferred reactive dyes used in preparations according to the invention are those containing one or more fluoro-containing triazinl or fluoro-containing pyrimidyl groups together with one or more sulphonic acid groups. The preferred reactive group of a dye used in a preparation according to the invention is the 2, 4-difluoro-5-chloro-pyrirnid-6-yi group.

Preferably the dispersing agent used in a preparation according to the invention is one conventional for aqueous systems. More preferably the dispersing agent used in a preparation according to the invention is a ligninsulphonate, an oxyligninsulphonate; a condensation product of ditolylether sulphonate and formaldehyde (commercially available under the trade name Baykanol SL) or the condensation product of naphthalene sulphonic acid and formaldehyde (commercially available under the trade name Lyocol 0). Most preferably the dispersing agent is a ligninsulphonate and/or the reaction product of naphthalene sulphonic acid and formaldehyde.

A preferred preparation according to the invention comprises: 15 to 30% of a cold dyeing reactive dye containing a fluoro-containing pyrimidyl or triazinyl group and one or more sulphonic acid groups; O to 0.45% of a buffer; O to 3.55% NaCI and/or Na2SO4; 50 to 70% water; and i) 8 to 16% of the sodium salt of dinaphthylmethanedisulphonic acid; and/or ii) 4 to 10% of a ligninsulphonate.

Further according to the invention there is provided an aqueous concentrate of sparingly soluble reactive dyes, which concentrate is stable to storage for 6 months containing: 10 to 55% of one or more cold dyeing reactive dyes; 4 to 25% of one or more dispersing agents; O to 1.0% buffer; and O to 3.5% salt; the percentages being based on the total weight of the dispersion.

Advantageously up to 3% of polyvinylpyrrolidone may be added to a preparation or concentrate according to the invention.

Advantageously up to 15% urea may be added to the preparation or concentration according to the invention containing a dye at the lower end of the range of sparingly soluble dyes.

Preferably the pH of a preparation or concentrate according to the invention is from 5 to 8, more preferably from 6 to 7.

Preferably the buffer is such as to maintain the pH of the preparation in the preferred ranges.

In this Specification, unless indicated to the contrary, where a range is given, the figures defining the range are included in the range.

A preparation or concentrate according to the invention may be used to dye a nitrogencontaining or hydroxy-containing substrate, preferably natural and regenerated cellulosic substrates such as cotton, wool and synthetic polyamide. Dyeing may be by exhaust dyeing, preferably at temperatures from 0 to 60"C (especially room temperature). Continuous dyeing processes such as cold printing and padding processes may be used.

Dyeings using preparations according to the invention have good fastness properties, and the preparations in particular produce level dyeings.

The invention will now be illustrated by the following Examples in which all parts and percentages are by weight.

Example 1 929 Parts of a dyestuff presscake of C.I.

Reactive Blue 209 (containing 41% actives and the rest being water, of which 3.5% of the actives is a mixture of NaCI and Na2SO4) are mixed in a suitable vessel with 200 parts water, 90 parts of a commerciall'y available ligninsulphonate and 180 parts of the sodium salt of dinaphthylmethane disulphonic acid and then homogenised for 30 minutes. The mixture is milled in a glass bead mill and dispersed until the average particle size is under 5,mum. After this, 2 parts of monosodium phosphate and 7.5 parts of disodium phosphate dissolved in 170 parts of water are added and the dispersion is diluted to give a total water content of 67.45%. The resulting dispersion contains: 17.95% C.I.Reactive Blue 209 0.65% NaCl+Na2SO4 9.00% sodium salt of dinaphthylmethane di suiphonic acid 4.50% ligninsulphonate 0.10% monosodium phosphate 0.35% disodium phosphate and 67.45% water.

The viscosity of the dispersion, measured on a Brookfield Viscometer Model RVP, 20 , Spindle 3, 20 rpm) is 400 cP.

The stability of the dispersion is tested after standing for 6 months at 40"C. No significant sedimentation is observed, nor is any thickening of the dispersion detected. The dyeing strength of the dispersion is that of a freshly prepared dispersion.

Example 2 By a method analogous to that of Example 1, but starting with 45.3 % presscake, the following dispersion can be prepared: 21.8% of the compound of formula 2a

2. 1% NaCI 8.8% sodium salt of dinaphthylmethane sulphonic acid 9.6% urea 0.7% polyvinylpyrrolidine and 57.0% water.

The properties of the resulting dispersion are similar to those of the preparation of Example 1.

The viscosity of the dispersion, measured on a Brookfield viscometer model RVP, spindle 3, 20 revs./min is 250 cp.

When higher amounts of salt (above 4%) are present in the presscake, a very noticeable thickening of the preparation occurs on storage.

Example 3 By a method analogous to that of Example 1 but starting with a 44.5 % presscake, the following dispersion can be prepared: 15.80% C.I. Reactive Yellow 111 0.06% NaCI and Na2SO4; 2.30% polyvinylpyrrolidine 4.70% ligninsulphonate and 77.14% water.

The viscosity of the dispersion measured on a Brookfield viscometer, Model RVP, Spindle 3, 20 revs/min is 550 CP.

Example 4 By a method analogous to that of Example 1 but starting with a 60.3% presscake, the following dispersion can be prepared: 24.1% C.I. Reactive Blue 104 3.7% NaCI and Na2SO4; 0.3% mono- and di-sodium phosphate; 10.8% sodium salt of dinaphthylmethane disulphonic acid and 61.1% water.

The viscosity of the dispersion measured on a Brookfield Viscometer, Model RVP, 20 , Spindle 3, 20 revs./min=170cP.

Application Example A dyebath containing 30 g/1 of the dispersion of Example 1, 50 g/1 NaCI and 20 g/l Na2CO3 (water-free) is made up and, at a liquor to goods ratio of 20:1, a wool fabric is dyed for 120 minutes at 400C. A blue dyeing results with good fastness properties. The backwater resulting is practically colourless.

In the above Application Example, an appropriate amount of any of the dispersions of Examples 2 to 4, can be used in place of that of Example 1.

Claims

1. An aqueous preparation comprising: 10-55% of a sparingly soluble reactive dye;

4.25% of a dispersing agent; 0-4% of a buffer and/or salt; and 25-86% of water; the percentages being based on the total weight of dispersion.

2. A preparation according to Claim 1 in which the reactive dye is a cold dyeing reactive dye.

3. A preparation according to Claim 1 or Claim 2 in which the reactive dye has a solubility of 50 to 250 g/l inclusive.

4. A preparation according to Claim 3 in which the reactive dye has a solubility of 5 to 150 g/l.

5. A preparation according to any one of the preceding claims in which the dispersing agent is selected from a ligninsulphonate, an oxyligninsulphonate; a condensation product of ditolylether sulphonate and formaldehyde and a condensation product of naphthalene sulphonic acid and formaldehyde.

6. A preparation according to any one of the preceding Claims comprising 15 to 30% of a cold dyeing reactive dye containing a fluoro-containing pyrimidyl or a fluoro-containing triazinyl group and one or more sulphonic or more suiphonic acid groups; O to 0.45% of a buffer; O to 3.55% NaCI and/or Na2SO4; 50 to 70% water; and i) 8 to 16% of the sodium salt of dinaphthylmethane disulphonic acid; and/or ii) 4 to 10% of a ligninsulphonate.

7. An aqueous concentrate of sparingly soluble reactive dyes, which concentrate is stable to storage for 6 months containing: 10 to 55% of one or more cold dyeing reactive dyes; 4 to 25% of one or more dispersing agents; O to 1.0 buffer; and O to 3.5% salt; the percentages being based on the total weight of the dispersion.

8. A process for dyeing nitrogen-containing or hydroxy-containing substrate comprising applying to the substrate a preparation according to any one of Claims 1 to 6 or a concentrate according to Claim 7.

9. A process according to Claim 8 in which the substrate is natural or regenerated cellulosic substrate.

10. A substrate to which a preparation according to Claims 1 to 6 or a concentrate according to Claim 7 have been applied.

11. A substrate according to Claim 10 which is natural or regenerated cellulose.

12. A preparation according to Claim 1, substantially as herein described with reference to any one of Examples 1 to 4.

13. A substrate substantially as herein described with reference to the Application Example