Patent Description:
Printing techniques like screen printing or inkjet printing have been used in the textile industry for some time mainly to impose a design on fabrics.

While cellulose fibres like cotton (CO) and linen are usually printed with reactive dyes, printing of synthetic fibre materials like polyester (PES) is typically performed by application of disperse dyes.

Many attempts have been made to develop efficient processes for printing PES/CO blends. Usually reactive dyes are combined with disperse dyes.

However, the use of such colorant mixtures is associated with several drawbacks and it is hardly possible to obtain the same shade and colour depth on the two fibres by this method. Alternatively, PES/CO blends and even CO can be printed with pigments and binders. However, poor handle and rubbing fastness are strong drawbacks of this technology. Accordingly, there is a need in particular for new dyes and colorant mixtures for a printing method for CO and PES/CO blends providing navy blue and black shades which works without a combination of reactive and disperse dyes and provides printings exhibiting good wash fastness, lightfastness, rubbing fastness, colour strength and brilliance as well as soft handle.

The compatibility of two or more dyestuffs in dyemixtures requires that said dyestuffs exhibit a similar uptake behaviour and build-up properties. If this condition is not fulfilled, the dyeings suffer from blotchiness and generally insufficient evenness.

<CIT> discloses a process for printing or dyeing of water swellable cellulosic fibers or cellulose-polyester fiber blends with benzisothiazole-pyridine azo dyes. <CIT> describes benzisothiazole-pyridine azo dyes for the dyeing of cellulose containing fibers. <CIT> discloses pyridine azo dyes for the trichomatic dyeing of hydrophobic fibers.

Surprisingly, we found that azo dyes based on benzisothiazoles as diazo components and specific <NUM>,<NUM>-aminosubstituted <NUM>-cyano-<NUM>-methylpyridines as coupling components can be combined with yellow, orange or red disperse dye and solvent dye and thus provide even dyeings showing good washing fastness and excellent light fastness results on cotton and polyester, as well as on PES/CO blends.

The present invention relates to colorant mixtures comprising.

Azo dyes based on benzisothiazoles as diazotizing components and <NUM>,<NUM>-aminosubstituted <NUM>-cyano-<NUM>-methylpyridines as coupling components are known, for example, from <CIT>.

Any radical denoting halogen may be fluorine, chlorine or bromine, in particular chlorine or bromine.

Preference is given to mixtures containing azo dyes of formula (<NUM>), wherein R<NUM> denotes hydrogen.

The dyes of formulae (<NUM>) and (<NUM>) are particularly preferred.

The dyes of formula (<NUM>) can be prepared according to known methods, for instance by conventional coupling reaction of the relevant diazonium salt with the respective coupling component, as described for example in <CIT>.

The coupling components for the preparation of the dyestuffs of formula (<NUM>) are usually prepared according to <CIT> by reacting <NUM>,<NUM>-dichloro-<NUM>-cyano-<NUM>-methylpyridine first with the compound R<NUM>-NH<NUM> and then with R<NUM>-NH<NUM>, wherein R<NUM> and R<NUM> are as defined above. In case R<NUM> and R<NUM> are not identical, normally a mixture of two different isomers arises. From the resulting coupling component mixture, the individual coupling components can be obtained by subsequent chromatographic separation.

However, with regard to the use-oriented properties of the resulting dyestuffs it is not necessary to separate the isomeric coupling components, but they can be reacted as a mixture with the diazonium salt thus providing a mixture of dyestuffs which has no detrimental effect in comparison with the single components.

Accordingly, the isomeric coupling components resulting from the reaction of <NUM>,<NUM>-dichloro-<NUM>-cyano-<NUM>-methylpyridine with R<NUM>-NH<NUM> and R<NUM>-NH<NUM>, as well as the dye mixtures resulting therefrom are usually not separated.

Disperse dyes and solvent dyes, which can be applied as component (B) are likewise known in the art.

Suitable examples are the following compounds:
C. Disperse Yellow <NUM>, C. Disperse Yellow <NUM>, C. Disperse Yellow <NUM>, C. Disperse Yellow <NUM>, C. Disperse Orange <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>:<NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Yellow <NUM>, C. Solvent Orange <NUM>, C. Solvent Orange <NUM>, C. Solvent Orange <NUM>, C. Solvent Orange <NUM>, C. Solvent Orange <NUM>, C. Solvent Orange <NUM>, C. Solvent Orange <NUM>, C. Solvent Orange <NUM>, <NUM>,<NUM>-diphenoxy-<NUM>,<NUM>-anthracenedione and <NUM>,<NUM>-diphenoxy-<NUM>,<NUM>-anthracenedione.

Particularly preferred are colorant mixtures comprising as component (B) a dye of formula (<NUM>)
<CHM>
or a dye of formula (<NUM>)
<CHM>.

The colorant mixture according to the invention can be prepared, for example, by mixing the individual dyes together. The mixing procedure is effected, for example, in suitable mills, e.g. ball mills or pin mills, as well as in kneaders or mixers. The colorant mixtures according to the invention can also be prepared, for example, by dispersing the colorants directly in the dyebath or the printing medium, if necessary in the presence of suitable dispersing agents.

The amount of the individual disperse dyes is governed by the shade to be obtained. The colorant mixtures according to the invention purposively contain, based on the total weight of components (A) + (B), <NUM> - <NUM> % by weight of component (A) and <NUM> - <NUM> % by weight of component (B), preferably <NUM> - <NUM> % by weight of component (A) and <NUM> - <NUM> % by weight of component (B), more preferably <NUM> - <NUM> % by weight of component (A) and <NUM> - <NUM> % by weight of component (B) and in particular <NUM> - <NUM> % by weight of component (A) and <NUM> - <NUM> % by weight of component (B).

The colorant mixtures according to the invention may be used for dyeing or printing cellulose (CEL) or PES or PES/CEL blend fibre material, especially textile material.

Accordingly, the invention further relates to a process for dyeing or printing cellulose or cellulose blend fibre material, wherein a colorant mixture containing components (A) and (B) as defined above is applied to the said material or incorporated into it.

The colorant mixtures according to the invention are suitable for dyeing in accordance with the thermosol process, in the exhaust process and for printing processes.

The application of the colorant mixtures according to the invention to the fibre materials can be effected in accordance with known dyeing methods. For example, cotton or cotton/PES blend fibre materials can be dyed in the exhaust process from an aqueous dispersion in the presence of customary anionic or non-ionic dispersants and, optionally, customary swelling agents (carriers) at temperatures of from <NUM> to <NUM>.

The colorant mixtures according to the invention can advantageously be applied in the process described in <CIT> as well as in the process described in <CIT>.

Accordingly, the invention further relates to a process for dyeing or printing cellulose or cellulose blend fibre material, characterised in that the fibre material is treated in any sequence with water, a water-soluble organic solvent having a boiling point ><NUM> and a colorant mixture as defined above.

In a preferred embodiment of this process the fibre material is in a first step treated with a water-soluble organic solvent having a boiling point ><NUM> and is subsequently printed with an aqueous ink comprising a colorant mixture as defined above.

In such processes, the said fibre materials can be in a variety of processing forms, e.g. in the form of fibres, yarns or nonwoven, woven or knitted fabrics.

It is advantageous to convert the colorant according to the invention into a colorant preparation prior to use. For this purpose, the colorant is ground so that its particle size is on average from <NUM> to <NUM> microns. Grinding can be carried out in the presence of beads and dispersants. For example, the dried colorant or the wet presscake is ground together with a dispersant or kneaded into a paste form together with a dispersant and then optionally dried in vacuo or by atomisation. After adding water to the dried powder or using the liquid dispersion, the resulting preparations can be used to prepare printing pastes and dyebaths.

For printing, the customary thickeners will be used, e.g. modified or unmodified natural products, for example alginates, British gum, gum arabic, crystal gum, locust bean flour, tragacanth, carboxymethyl cellulose, hydroxyethyl cellulose, starch or synthetic products, for example polyacrylamides, polyacrylic acid or copolymers thereof, or polyvinyl alcohols.

The dyes of formula (<NUM>) according to the invention are also suitable as colorants for use in recording systems. Such recording systems are, for example, commercially available ink-jet printers for paper or textile printing, or writing instruments, such as fountain pens or ballpoint pens, and especially ink-jet printers. For that purpose, the dyes according to the invention are first brought into a form suitable for use in recording systems. A suitable form is, for example, an aqueous ink, which comprises the dyes according to the invention as colorants. The inks can be prepared in customary manner by grinding the dyes to the appropriate particle size in the nanometer range and mixing together the individual components, if necessary in combination with suitable dispersing agents, in the desired amount of water and, optionally, co-solvents.

The colorants according to the invention impart to the said materials, especially to CO, PES and CO/PES blend materials, level colour shades having good in-use fastness properties such as fastness to light, fastness to heat setting, fastness to pleating, fastness to chlorine and wet fastness, e.g. fastness to water, to rubbing, to perspiration and to washing; the finished dyeings are further characterised by good fastness to rubbing. Special emphasis should be given to the good fastness to washing, fastness to rubbing and excellent light fastness of the dyeings, as well as a very soft handle.

The present invention further relates to the above-mentioned use of the dyes according to the invention as well as to a process for the dyeing or printing of cellulose or cellulose blend fibre materials, especially textile materials, in which process a dye according to the invention is applied to the said materials or incorporated into them. The said fibre materials are preferably textile CO, PES or CO/PES materials. Further substrates that can be treated by the process according to the invention and preferred process conditions can be found hereinbefore in the more detailed description of the use of the dyes according to the invention.

Preferably, the dye of formula (<NUM>) is applied to CO, PES or CO/PES blend fibre material by screen-printing or by inkjet-printing.

In the case of the ink-jet printing method, individual droplets of ink are sprayed onto a substrate from a nozzle in a controlled manner. It is mainly the continuous ink-jet method and the drop-on-demand method that are used for that purpose. In the case of the continuous ink-jet method, the droplets are produced continuously, droplets not required for the printing operation being discharged into a receptacle and recycled. In the case of the drop-on-demand method, on the other hand, droplets are generated as desired and used for printing; that is to say, droplets are generated only when required for the printing operation. The production of the droplets can be effected, for example, by means of a piezo ink-jet head or by thermal energy (bubble jet). Preference is given to printing by means of a piezo ink-jet head and to printing according to the continuous ink-jet method.

The present invention accordingly relates also to aqueous inks that comprise the dyes of formula (<NUM>) according to the invention and to the use of such inks in an ink-jet printing method for printing a variety of substrates, especially textile fibre materials, the definitions and preferences indicated above applying to the dyes, the inks and the substrates.

The invention relates also to CO, PES or CO/PES blend fibre materials, preferably CO, PES or CO/PES textile materials, dyed or printed by the said process.

The dyes according to the invention are, in addition, suitable for modern reproduction processes, e.g. thermotransfer printing.

The Examples that follow serve to illustrate the invention. Parts therein are parts by weight and percentages are percentages by weight, unless otherwise indicated. Temperatures are given in degrees Celsius. The relationship between parts by weight and parts by volume is the same as between grams and cubic centimetres.

To <NUM> parts of sulfuric acid (<NUM>%) maintained at <NUM>-<NUM> are added <NUM> parts of water over a period of <NUM> minutes. Over a period of <NUM> minutes at <NUM>-<NUM>, <NUM> parts of <NUM>-amino-<NUM>-nitro-<NUM>,<NUM>-benzoisothiazole are then added to the reaction mixture. After stirring for <NUM> hours at <NUM>-<NUM>, the reaction mixture is cooled down to <NUM>-<NUM> and <NUM> parts of nitrosylsulfuric acid (<NUM>%) are added over <NUM> minutes. This reaction mixture (A) is stirred for <NUM> hours at <NUM>-<NUM>. In the meantime, to <NUM> parts of acetic acid (<NUM>%) are added <NUM> parts of <NUM>,<NUM>-bis-(<NUM>-methoxypropylamino)-<NUM>-cyano-<NUM>-methylpyridine at room temperature over a period of <NUM> minutes, after which <NUM> parts of sulfuric acid are added, followed by <NUM> parts of ice/water mixture and the mixture is stirred for <NUM> minutes. After cooling down to <NUM>-<NUM>, <NUM> parts of the previous reaction mixture (A) are added over a period of <NUM> minutes. At the same time, <NUM> parts of acetic acid and <NUM> parts of water are added and the temperature is kept at <NUM>-<NUM>. The reaction mixture so obtained is cooled down to <NUM>-<NUM> and <NUM> parts of sodium hydroxide solution (4N) are added over <NUM> hours whilst maintaining the reaction temperature at <NUM>-<NUM>. The reaction mixture is stirred for an additional <NUM> hours at <NUM>-<NUM>, then the temperature is allowed to rise slowly to <NUM> with stirring, after which <NUM> parts of sodium hydroxide solution (4N) are added at <NUM>-<NUM> over a period of <NUM> hours. Filtration of the reaction mixture and washing with water affords <NUM> parts of the crude filter cake.

To <NUM> parts of sulfuric acid (<NUM>%) maintained at <NUM>-<NUM> are added <NUM> parts of water over a period of <NUM> minutes. Over a period of <NUM> minutes at <NUM>-<NUM>, <NUM> parts of <NUM>-amino-<NUM>-nitro-<NUM>,<NUM>-benzoisothiazole are then added to the reaction mixture. After stirring for <NUM> hours at <NUM>-<NUM>, the reaction mixture is cooled down to <NUM>-<NUM> and <NUM> parts of nitrosylsulfuric acid (<NUM>%) are added over <NUM> minutes. This reaction mixture (A) is stirred for <NUM> hours at <NUM>-<NUM>. In the meantime, to <NUM> parts of acetic acid (<NUM>%) are added <NUM> parts of <NUM>,<NUM>-bis-(p-tolylamino)-<NUM>-cyano-<NUM>-methylpyridine at room temperature over a period of <NUM> minutes, after which <NUM> parts of sulfuric acid are added, followed by <NUM> parts of ice/water mixture and the mixture is stirred for <NUM> minutes. After cooling down to <NUM>-<NUM>, <NUM> parts of the previous reaction mixture (A) are added over a period of <NUM> minutes. At the same time, <NUM> parts of acetic acid and <NUM> parts of water are added and the temperature is kept at <NUM>-<NUM>. The reaction mixture so obtained is cooled down to <NUM>-<NUM> and <NUM> parts of sodium hydroxide solution (4N) are added over <NUM> hours whilst maintaining the reaction temperature at <NUM>-<NUM>. The reaction mixture is stirred for an additional <NUM> hours at <NUM>-<NUM>, then the temperature is allowed to rise slowly to <NUM> with stirring, after which <NUM> parts of sodium hydroxide solution (4N) are added at <NUM>-<NUM> over a period of <NUM> hours. Filtration of the reaction mixture and washing with water affords <NUM> parts of the crude filter cake.

Differential Scanning Calorimetry: decomposition > <NUM> <MAT>.

<NUM>H-NMR (CDCl<NUM>, <NUM>): δ=<NUM> (s, <NUM>), <NUM> (d, <NUM>), <NUM> (d, <NUM>), <NUM>-<NUM> (m, <NUM>), <NUM> (s, <NUM>), <NUM> (s, <NUM>), <NUM> (s, <NUM>).

<NUM> is repeated by using a mixture of <NUM>-phenylamino-<NUM>-(<NUM>-phenylethylamino)-<NUM>-cyano-<NUM>-methylpyridine and <NUM>-(<NUM>-phenylethylamino)-<NUM>-phenylamino-<NUM>-cyano-<NUM>-methylpyridine as coupling component instead of <NUM>,<NUM>-bis-(<NUM>-methoxypropylamino)-<NUM>-cyano-<NUM>-methylpyridine.

As described in Example I. <NUM>, the following dyestuffs can be prepared in an analogous manner:.

The following dyes are used in the Application Examples:
<CHM>
<CHM>
<CHM>
<CHM>.

The procedure described in <CIT> is carried out using the disperse dyes according to the invention and the thus obtained printed fabrics exhibit very good light fastness, wash fastness and rubbing fastness. The dispersion formulation is variable according to the dyes' properties and can be modified accordingly by the skilled artisan.

A cotton/polyester fabric (Reference Nr. <NUM>-<NUM>, CO/PES <NUM>/<NUM>, fixed, bleached, mercerized, <NUM>/m<NUM>, <NUM>/<NUM> tex) is padded at room temperature with an aqueous formulation containing <NUM>/l of MACROGOL <NUM> EF (PEG, average molecular weight Mw = <NUM>, supplied by Brenntag), <NUM>/l PREPAJET UNI (inkjet auxiliary, polyacrylic acid derivative, supplied by Huntsman) and <NUM>/l ALBATEX AR (levelling agent, supplied by Huntsman) with a pick-up rate of <NUM>-<NUM> %. After drying at <NUM>-<NUM> for <NUM>, the thus prepared fabric is printed by ink-jet with an aqueous ink containing.

After drying at <NUM> - <NUM> for <NUM>, the printed fabric is fixed at <NUM> for <NUM>. After cooling down, the printed fabric is rinsed with cold soft water and finally washed with a solution of <NUM>/l commercial tenside, rinsed and dried.

Deep black prints of high color strength having good all-round fastness properties, especially wash fastness, rubbing fastness and light fastness, are obtained.

Similar results and properties are obtained if the dried print is fixed at lower temperature with longer fixation time or if it is fixed with superheated steam at <NUM> for <NUM>.

The same procedure as described in Example II. <NUM> is applied to a cotton fabric (Reference Nr. <NUM>-<NUM>, CO-crettone bleached, <NUM>/m<NUM>, <NUM>/<NUM> tex) instead of a cotton/polyester fabric. Similarly to cotton/polyester, very deep black prints of very high color strength having good all-round fastness properties, especially wash fastness, rubbing fastness and light fastness, are obtained on cotton/polyester fabric.

Similar results and properties are obtained if the dried print is fixed at lower temperature with longer fixation time or is fixed with superheated steam at <NUM> for <NUM>.

A polyester fabric (Reference Nr. <NUM>-<NUM>, fixed, <NUM>/m<NUM>) is padded in a standard procedure for subsequent inkjet printing, with an aqueous formulation based on PREPAJET UNI (inkjet auxiliary, polyacrylic acid derivative, supplied by Huntsman). The thus prepared fabric is printed by ink-jet with the same inkjet ink as used in Example II. <NUM> and Example II.

The same procedure as described in Example II. <NUM> is applied using an aqueous ink containing.

The procedure described in Example II. <NUM> is applied to a cotton fabric (Reference Nr. <NUM>-<NUM>, CO-cretonne bleached, <NUM>/m<NUM>, <NUM>/<NUM> tex) instead of a cotton/polyester fabric.

Similarly to cotton/polyester, very deep black prints of high color strength having good all-round fastness properties, especially wash fastness, rubbing fastness and light fastness, are obtained on cotton/polyester fabric.

Standard screen printing paste (flat bed or rotary) is applied according to a method similar to that described in <CIT>. Fixing and washing conditions are similar to those mentioned in Examples II. Viscosity is adapted to the relevant flat bed and rotary screen printing method.

A cotton/polyester fabric (Reference Nr. <NUM>-<NUM>, CO/PES <NUM>/<NUM>, fixed, bleached, mercerized, <NUM>/m<NUM>, <NUM>/<NUM> tex) is screen printed at room temperature with a printing paste containing.

The same procedure as described in Example II. <NUM> is applied to a cotton fabric (Reference Nr. <NUM>-<NUM>, CO-crettone bleached, <NUM>/m<NUM>, <NUM>/<NUM> tex) instead of a cotton/polyester fabric.

Similarly to cotton/polyester, very deep black prints of very high color strength having good all-round fastness properties, especially wash fastness, rubbing fastness and light fastness, are obtained on cotton/polyester fabric.

The same procedure as described in Example II. <NUM> or Example II. <NUM> is applied to a PES fabric (Reference Nr. <NUM>-<NUM>, fixed, <NUM>/m<NUM>) instead of a cotton/polyester fabric, and using a standard stock paste for PES printing which does not contain any Macrogol <NUM> EF.

Similarly to cotton/polyester and cotton, very deep black prints of very high color strength having good all-round fastness properties, especially wash fastness, rubbing fastness and light fastness, are obtained on cotton/polyester fabric.

The same procedure as described in Example II. <NUM> is applied using a printing paste containing.

The same procedure as described in Example II. <NUM> is applied using a different quality cotton/polyester fabric (Reference No <NUM>-<NUM>, CO/PES <NUM>/<NUM>) and using a printing paste containing disperse dye of formula (<NUM>), disperse dye of formula (<NUM>) and disperse dye of formula (<NUM>).

The same procedure as described in Example II. <NUM> is applied using a different quality cotton/polyester fabric (Reference No <NUM>-<NUM>, CO/PES <NUM>/<NUM>) and using an aqueous ink containing.

The same procedure as described in Example II. <NUM> is applied using the aqueous ink described in Example II.

Claim 1:
A colorant mixture comprising
(A) at least one blue- or black-dyeing disperse dye of formula
<CHM>
wherein R<NUM> denotes hydrogen or halogen,
R<NUM> and R<NUM> are each independently of the other <NUM>-methoxypropyl, phenyl, tolyl or <NUM>-phenylethyl; and
(B) at least one dye of formula (<NUM>) or (<NUM>)
<CHM>
<CHM>
wherein X denotes -O-, -S- or -NHCO-,
R<NUM> and R<NUM> are as defined above, and
R<NUM> is -CF<NUM> or -CN.