DE2735376A1 - Stabilised form of azo dispersion dye - made by heating to give 1-ethyl:hexyl 3-cyano 4-methyl 5-nitrophenyl:azo 6-hydroxy pyridone crystal form with improved rub fastness - Google Patents

Abstract

New crystal form of the azo dispersion dye 1-(2'-ethylhexyl) 3-cyano 4-methyl 5-(o-nitrophenylazo)6-hydroxy pyrid-2-one with structure characterised by an X-ray diffraction diagram with a strong line at 8.9 a, medium line at 20.3A and medium-to-weak lines at 19.0, 14.3, 10.2, 9.6, 6.4 and 3.76A. They are made b heating the coupling prod. in water and/or organic fluid. Dyeing of aromatic polyester fibres in greenish-yellow shades. Excellent fastness to light, wet treatments and dry heat. Stability of aq dispersions during the dyeing process is increased by the crystal modification, giving improved resistance to rubbing on the fibres.

Description

Stabilized disperse azo dye

The invention relates to a stabilized form of 1- (2'-ethylhexyl) -3-cyano-4-methyl-5- (o-nitrophenylazo) -6-hydroxypyrid-2-one in a new crystal phase and to a method for producing the same.

GB-PS 1,398,741 discloses certain water-insoluble monoazo dyes described, which differ from 3-cyano-4-methyl-6-hydroxypyrid-2-ones, which in the 1-position have an alkyl radical having 5 to 12 carbon atoms, derive.

Example 1 of this UK patent describes the preparation of the monoazo dye 1- (2'-Ethylhexyl) -3-cyano-4-methyl-5- (o-nitrophenylazo) -6-hydroxypyrid-2-one, by Coupling of diazotized o-nitroaniline with 1- (2'-ethylhexyl) -3-cyano-4-methyl-6-hydroxypyrid-2-one in an aqueous medium at a temperature between 0 and 50C. In this example is also the use of this dye as a dispersion in an aqueous medium for Dyeing of textile materials from aromatic polyesters described.

However, when the dye is used on textile materials made of aromatic polyesters is applied in a batch process (i.e. from an aqueous dye bath), then the dyeings obtained suffer from the disadvantage that they are bad Have rubbing fastness due to the presence of loose dye the surface of the fibers. The formation of such loose dye has been high Security is due to a change in the physical form of the dye, which occurs during the long dyeing process.

It has now been found that this disadvantage can be eliminated, if you add the dye to a Heat treatment which undergoes it in a new crystal structure with a certain X-ray spectrum converts. This new form of the dye remains after conversion into an aqueous one Dispersion stable during the dyeing process, so little or no slack Dye is obtained on the surface of the fibers, which is why the dyed material has a satisfactory fastness to rubbing. The present invention relates to hence the new crystal structure of the dye and a method of preparation of such a dye.

According to the invention, 1- (2'-ethylhexyl) -3-cyano-4-methyl-5- (o-nitrophenylazo) -6-hydroxypyrid-2-one is used proposed with a crystal structure indicated by an X-ray diffraction diagram is marked, the one strong line at a level distance of 8.9 A, one middle o line at 20.3 A and six lines of medium to weak intensity at 19.0 Å, 14.3 Å, 10.2 Å, 9.6 Å, 6.4 Å and o 3.76 Å.

According to the invention, a method for producing the 1- (2'-ethylhexyl) -3-cyano-4-methyl-5- (o-nitrophenylazo) -6-hydroxypyrid-2-ones according to the invention proposed with the given X-ray diffraction diagram, which thereby is carried out that the by coupling of diazotized o-nitroaniline with 1- (2'-ethylhexyl) -3 cyano-4-methyl-6-hydroxypyrid-2-one obtained dye in water or in a organic liquid or in a mixture of water and an organic liquid heated.

The method according to the invention can expediently be carried out in this way be that this azo compound in water and / or an organic liquid at one temperature between 350C and the boiling point of the medium, preferably at a temperature between 60 and 1000C. The transformation of the Requires azo compound in the form with the given X-ray diffraction diagram usually that the heating is carried out for a period of between 1/2 hour.

and 3 hours. The new form of the azo compound can then can be isolated in the usual way. For example, it can when in the liquid Medium is insoluble at the reaction temperature, can be filtered off directly.

However, when an organic liquid is used, in which it is soluble, then it is preferred to filter the reaction mixture off to cool the solid to room temperature.

It is further preferred that the pH of the liquid medium in which the mentioned heat treatment is carried out is greater than 7 and preferably ranges from 9 to 12. Such a pH can be obtained by an alkaline agent such as sodium carbonate or sodium hydroxide is added to the liquid Medium admits.

Optionally, the liquid medium can be cationic, anionic and contain nonionic dispersant.

Examples of the organic liquids mentioned are alcohols, such as methanol, ethanol, n-propanol and n-butanol, ketones such as acetone, and Hydrocarbons such as toluene.

However, it is preferred to use the method according to the invention directly to be carried out after the formation of the azo compound.

For this purpose, after coupling the diazotized o-nitroaniline with the 1- (2-Ethylhexyl) -3-cyano-4-methyl-6-hydroxypyride -2-on which one is carried out in an aqueous medium at a temperature below 250C, the Temperature raised, preferably to a value between 60 and 1000C, whereby it is held at this value for a sufficient time (usually 1st up to 3 hours) until the entire azo compound is in the new form with the specified X-ray diffraction diagram has been transferred. The dye is then filtered off.

In the accompanying drawing is the characteristic X-ray diffraction diagram the mentioned azo compound and the new parfum form. The horizontal The axis of the graph shows the plane distances of the crystal and the vertical axis approximates the relative intensities. The new form of the dye is represented by the solid lines, which show that there is a strong line at a plane spacing of 8.9 Å, a middle line at 20.3 Å, and six lines medium to 0 0 0 weak intensity at 19.0 A, 14.3 A, 10.2 A, 9.6 A, o o 6.4 A and 3.76 A are available. The X-ray diffraction diagram for the azo compound (from which the new mold is made) is indicated by dashed lines in the drawing Lines shown.

The X-ray diffraction diagram shown in the specification is based on conventional powder technology, using Cu-K-alpha radiation and where the diffraction intensity is plotted as a curve on a scintillation counter where the horizontal axis is the diffraction angle and the vertical axis is the Show intensity of diffraction. For the purposes of illustration, the angle of diffraction by using standard tables with level spacing in Angstrom units (A) which are independent of changes in the instrument. The specified values are accurate to within 2%, and in most cases this will be Deviation if less than 1 *. When interpreting the present description and the claims, these deviations must be taken into account.

When the 1- (2'-ethylhexyl) -3-cyano-4-methyl-5- (o-nitrophenylazo) -6-hydroxypyrid-2-one with the given X-ray diffraction pattern by milling in an aqueous Medium containing one or more dispersants into an aqueous dispersion is transferred, then this dye is suitable for dyeing textile materials from aromatic polyesters by a dyeing, padding or printing process, whereby the textile materials made of aromatic polyesters in greenish-yellow shades with excellent fastness to light, NaS treatments and dry heat treatment be convicted.

In particular, the aqueous dispersions mentioned last for a long time Storage stable times. In this regard, they are aqueous dispersions of those mentioned Azo compound that does not undergo heat treatment according to the present invention has been subjected to, substantially superior.

The invention is further illustrated by the following example, wherein the parts and percentages are expressed by weight.

Example A solution of 145 parts of 2-nitroaniline in 1000 parts of a own aqueous sulfuric acid is in a mixture of 1300 parts of ice and 1300 parts Poured water, whereupon 518 parts of a 14% aqueous sodium nitrite solution admitted The temperature of the mixture is kept at 0 to 50C by external cooling will. The mixture is stirred for 15 min. And filtered, and the filtrate, which the Containing diazonium compound becomes a solution of 284 parts of the sodium salt of 1- <2'-ethylhexyl) -3-cyano-4-methyl-6-hydroxypyrid-2-one in 2000 parts of water added, the pH of the resulting mixture being adjusted by the simultaneous addition of Sodium acetate to 6 to 7 and the temperature of the mixture by external cooling 0 to 50C. The mixture is stirred for 1 hour at this temperature, the pH of the mixture is raised to 10 by adding sodium hydroxide and that The mixture is then stirred at 80 ° to 850 ° C. for 2 hours. The precipitated dye will finally filtered off and washed in water.

The resulting wet paste contains 16.4% dye.

X-ray examination of the dye on a Philips diffractometer, equipped with a copper target and a nickel filter shows that it has an X-ray diffraction diagram showing a strong line o at a Level spacing of 8.9 A, a middle line o at 20.3 A and six lines middle to low intensity at 19.0 A, 14.3 A, 10.2 A. 9.6 A, 6.4 A and 3.76 A.

In contrast to this, a dye which was produced according to the above procedure but isolated without heating to 80 to 850C, an X-ray diffraction pattern 0 with a strong line at 11.9 A and six medium to weak lines at 7.0 Å, 6.8 Å, 6.4 Å, 6.0 Å, 4.66 Å and 3.38 A.

A mixture of 1070 parts of the prepared according to the above procedure Dye paste, 700 parts of a 25% strength aqueous sodium lignosulfonate solution (commercially available as Reax 85A available) and 225 parts of a 39% strength aqueous solution of the disodium salt of di- (2-sulfonaphth-1-yl) methane was subjected to mechanical grinding in a ball mill subjected until the particle size of the dye is reduced to less than 3n was. To 1049 parts of the resulting mixture was 354 parts of a 39% aqueous Solution of the disodium salt of di- (2-sulfonaphth-1-yl) methane and 7.35 parts of sodium isopropylnaphthalene sulfonate added, whereupon the pH was then adjusted to 7.8 by adding acetic acid. The resulting mixture was finally spray dried to form a solid dye composition containing: 24.45% dye, 24.45% sodium lignosulfonate, 49.10% disodium salt of di (2-sulfonaphth-1-yl) methane and 2.00% sodium isopropylnaphthalene sulfonate.

The obtained dye composition was then subjected to a laboratory package dyeing machine using 1.4 parts of the aforementioned dye composition for each 100 parts of yarn applied to a textured polyester yarn, with the dyeing using a coloring liquid with a pH of 5.5 for 45 to 130 Min. Has been executed. The dyed yarn was then rinsed in cold water and dried. The yarn was dyed a bright yellow shade. On the surface of the yarn little or no dye was present, giving the yarn excellent resistance to rubbing exhibited.

The dye prepared according to the above procedure, however, at insulation has not been heated to 80 to 850C was would similarly converted into a solid dye composition, which is then converted into similarly applied to textured polyester yarn. It was true The hue of the yarn was satisfactory, but there was a significant amount of loose dye present on the surface of the yarn, which makes the yarn poor in rubbing fastness exhibited.

Low intensity Distance between planes in Å

Claims (9)

PATENT CLAIM G 1- (2'-Ethylhexyl) -3-cyano-4-methyl-5- (o-nitrophenylazo) -6-hydroxypyrid-2-one with a crystal structure, which is characterized by an X-ray diffraction diagram which is a strong line at an o o level spacing of 8.9 A, a medium one Line at 20.3 A and six lines of medium to low intensity at 19.0 Å, 14.3 Å, 10.2 Å, 9.6 Å, 6.4 Å and 3.76 Å. 2. Process for the preparation of 1- (2'-ethylhexyl) -3-cyano-4-methyl-5- (o-nitrophenylazo) -6-hydroxypyrid-2-one with the crystal structure defined in claim 1, characterized in that that by coupling diazotized o-nitroaniline with l- (2'-ethylhexyl) -3-cyano-4-methyl-6-hydroxypyrid-2-one obtained azo compound in water or in an organic liquid or a Mixture of water and an organic liquid is heated. 3. The method according to claim 2, characterized in that the heating is carried out at a temperature between 60 and 1000C. 4. The method according to claim 2, characterized in that diazotized o-Nitroaniline in an aqueous medium at a temperature below 250C with 1- (2'-Ethylhexyl ) -3-cyano-4-methyl-6-hydroxypyrid-2-one is coupled and that the reaction mixture then for a period of 1 to 3 hours to a temperature between 60 and 1000C is heated. 5. The method according to any one of claims 2 to 4, characterized in that that the heat treatment is carried out at a pH higher than 7. 6. The method according to claim 5, characterized in that the heat treatment is carried out at a pH of 9 to 12. 7. The method according to any one of claims 2 to 6, characterized in that that the liquid medium is also cationic, anionic or non-ionic Contains dispersant. 8. Use of the dye having the crystal structure of claim 1 together with a dispersant to produce an aqueous dispersion. 9. Use of the dye having the crystal structure of claim 1 for dyeing textile materials.