GB1584212A

GB1584212A - Disazo dyestuffs

Info

Publication number: GB1584212A
Application number: GB20167/77A
Authority: GB
Original assignee: ACNA Chimica Organica SpA
Current assignee: ACNA Chimica Organica SpA
Priority date: 1976-05-14
Filing date: 1977-05-13
Publication date: 1981-02-11
Also published as: FR2351157A1; DE2721763A1; SE7705421L; NL7705125A; JPS52139139A; SE422587B; CH621229GA3; BE854616A; IT1063100B; FR2351157B1; CH621229B

Abstract

A process for dyeing or printing cellulosic fibres or their mixtures with synthetic fibres, in particular mixed polyester/cotton fibres, in shades from golden-yellow to orange envisages dyeing or printing the material in the presence of water and a solvent selected from the class of the polyols and their ether derivatives or esters of organic acids, with bisazo dyes of the general formula: <IMAGE> where: X1, X2, X3 and X4 are H, CH3 or OCH3, Y is Cl, Br or CH3 and n is 0, 1 or 2. f

Description

(54) DISAZO DYESTUFFS (71) We, AZIENDE COLORI NAZIONALI AFFINI ACNA S.p.A., of Largo Donegani 1/2, 20121 Milano, Italy, an Italian Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a class of disazo dyestuffs suitable for dyeing and printing cellulosic material swellable with water, and mixtures of such material with synthetic materials, in particular for dyeing and printing polyester-cotton blends.

Processes are already known for dyeing polyester-cotton blended fibre, wherein the blend components are dyed in respective separate steps by different dyestuffs. These processes involve serious drawbacks, such as complexity of execution, possibility of reciprocal stainings, and necessity of using large amounts of dyestuffs. One such process is described, for example, in US patent 3,313,590.

Other processes for dyeing polyester-cellulose blended fibre are known, that utilize the property of the cellulosic material to swell in the presence of water, in which the blend is dyed in one step only with one dyestuff which is insoluble or little soluble in water, dissolved, in its turn, in suitable solvents, such as polyols and their ether-derivatives, or esters of organic acids. One of these processes is described, for instance, in US patent 3,706,525.

The dyestuffs to be employed according to the last-described process need to meet the following requirements: - good affinity towards polyester fibres - good affinity towards cellulose fibres swollen with the water-solvent mixture.

- capability of providing uniform dyeings on both fibres - capability of providing dyeings and prints resistant to sunlight, abrasion and laundering.

It is an object of the invention to provide a class of dyestuffs suitable for dyeing and printing cellulosic material capable of swelling in the presence of water, and mixtures of such material with synthetic materials, in particular blended polyester-cotton and blended polyester-rayon fibres, by the second of the processes described above, and especially by the so-called "Thermosol" process, in which the dyeing is effected the presence of suitable solvents.

The present invention consists in a class of dyestuffs having a good affinity towards both components of a polyester-cellulose blend, and capable of providing substantially uniform and stable dyeings and printings, having the general formula:

where X1, X2, X3 and X4, which may be the same or different, are H, CH3 or OCH3 Y = Cl, Br or CH3 n = 0, 1 or 2 These dyestuffs have in general shades ranging from gold-yellow to orange.

The present invention also consists in a process for preparing disazo dyestuffs of general formula (I), which comprises diazotizing in an acid medium an amine of formula:

to form the disazo compound, coupling the latter with a derivative of the 1-phenyl-5pyrazolone-3-acetic acid having the formula:

to form the disazo compound, and condensing this preferably in the absence of solvent with an amine of the formula:

where, in each of these formulae Xl, X2, X3, X4, Y and n have the meaning previously defined.

The dyestuffs so prepared may be ground in the presence of suitable dispersing agents, for instance sodium lignin-sulphonate and Saltetra SS, to a particle size of about 1 11, and applied to the blended fibres in the form of an aqueous paste mixed with a solvent boiling above 1500C which may be selected from those usually employed for the Thermosol process (e.g. a polyethylene glycol ether). Suitable solvents include polyols, polyol ethers and organic acid esters.

The dyeing and printings may be thermoset at about 200"C for 1 minute and then soaped to remove any surplus dyestuff.

The dyestuffs of the invention are particularly useful for dyeing blends of 65 - 80% of polyethylene terephthalate and 20 - 35% of cotton.

The following examples illustrate how the invention may be carried into effect. The stability tests were conducted according to UNI standards. Ihe setting percentages indicated in the examples measure the ratio between the dyestuff stably retained by the fibre and the total employed. The coverage measures the distribution degree of the dyestuff onto the two fibres. Unless otherwise specified, the term "parts" is to be considered as expressed in weight unit.

In the course of a study on disazo dyestuffs derived from 1-phenyl-5-pyrazolone and free from water-solubilizing groups, it has suprisingly been found that the selection of chemical structures to provide dyestuffs suitable for the dyeing and printing of polyester-cellulose blended fibres according to the above-indicated technique is very critical.

It has been observed. in fact, that, while a series of dyestuffs of the general formula (I) can be used successfully to dye and print polyester-cellulose blends, other dyestuffs having a similar shade and a structure very close to that of the dyestuffs of the present invention give unsatisfactory results in the dyeing and printing of such blends: they exhibit a low affinity, an insufficient coverage of the blend and low stabilities to abrasion and/or to laundering.

This is shown for example in comparative tests 9, 10, 11 and 12.

Example 1 8.0 parts of a dyestuff having the following structure:

were micro-fined with 8 parts of Saltetra SS (a condensate of formaldehyde and Schaffer acid), 12 parts of ethylene glycol and 105 parts of water. From such mixture 1000 parts of a printing paste were prepared by incorporating 100 parts of polyoxyethylene glycol monomethyl-ether (molecular weight about 350), 37 parts of sodium alginate and 730 parts of water. The resulting paste was applied to a yarn of polyester-cotton 65 : 35 blended fibre scoured for printing, and then allowed to air-dry (about 20 minutes).

The setting of the dyestuff onto the two fibres constituting the blend was carried out in a Thermosol apparatus, operated at 200"C, for 60 seconds. The thermoset print was subjected to a three-step cleaning treatment: 1. cold washing 2. soaping (10 minutes, at 90"C, using 1 g/l of Diapon T (Registered Trade Mark) 3. rinsing An orange shade print, with an intensity of about 112 E;C.E. was thus obtained, from which the following data could be determined: - blend coverage: good - setting: more than 90coo - stability to dry/wet rubbing: 4 - 5/4 - stability to sunlight: 5 - stability to washing at 60"C: 4/4 - 5/4 - 5 where the first figure corresponds to the alteration of the blend shade, the second figure to colour loss on polyester and the third to colour loss on cotton.

The dyestuff was synthesised in the following way: 4.2 parts of p-amino azotoluene were heated to boiling with 10 ml of HC1, -d = 1.18, and with 40 ml of water. After cooling to 5 10 C and dilution of the mass, the amine was diazotized by adding gradually 1.4 parts of sodium nitrite in 10 ml of water. After a further 1-hour stirring, the diazo solution was clarified and poured at 5 - 10 C into a solution of 4.8 parts of 1-phenyl-2-pyrazol-5-one-3acetic acid in 30 ml of acetic acid and 50 ml of water. During the coupling reaction the pH was kept at 4 - 5 by addition of sodium acetate crystals. After stirring 1-hour at 5 - 100C the product was filtered, and the precipitate was washed with water and dried. 8.8 parts of the following intermediate dyestuff were obtained:

8.0 parts of such intermediate were treated incrementally (i.e. by addition in successive portions) with 20 parts of aniline at 1800C for 2 hours. At the conclusion, the solution was poured into 200 ml of water and the pH brought to 5 - 6 by addition of HC1 d = 1.18. After stirring for 30 minutes, the product was filtered, and the filter-cake was washed with water and dried. 6.4 parts of dyestuff were recovered.

Example 2 Following the procedure described in example 1, a printing was effected on a material of the same blend using a dyestuff having the following structure:

A yellow-orange shade print was obtained, whose characteristics, at the obtained intensity (about 1/2 E.C.E.), were as follows: - coverage of the blend: excellent - setting: 94% - stability to dry/wet rubbing: 4/3 - 4 - stability to sunlight: 5 - 6 - stability to washing at 60"C: 4/3/3 - 4 The dyestuff synthesised by a process analogous to that of example 1.

Example 3 Operating according to the procedure described in example 1, a printing was effected on a material of the same blend using a dyestuff having the following structure:

A yellow-orange shade print was obtained of intensity 1/2 E.C.E., for which the following characteristics were ascertained: - coverage of the blend: excellent - setting: better than 90% - stability to dry/wet rubbing: 4/3 - 4 - stability to sunlight: 5 - 6 - stability to washing at 600C: 4/3 - 4/4 - 5 The dyestuff was synthesised by a procedure analogous to that of example 1.

Example 4 Operating in accordance with the procedure described in example 1, a printing was effected on a material of the same blend using a dyestuff having the following structure:

An orange shade print was so obtained, whose characteristics, at the intensity obtained (about 1/2 E.C.E.), were as follows: - coverage of the blend: good - setting: 95% - stability of dry/wet rubbing: 4/4 - stability to sunlight: 5 - 6 - stability to washing at 60"C: 4/4 - 5/4 - 5 The dyestuff was synthesised by a procedure analogous to that of example 1.

Example 5 Following the procedure described in example 1, a printing on a material of the same blend was effected with a dyestuff having the following structure:

An orange shade print was obtained, for which the following characteristics were determined (the intensity being 1/2 E.C.E.): - coverage of the blend: good - setting: better than 90% - stability to dry/wet rubbing: 4 - 5/4 - stability to sunlight: 5 - 6 - stability to washing at 600C: 3 - 4/3/4 The dyestuff was synthesised by a procedure analogous to that of example 1.

Example 6 Following the procedure described in example 1, a printing on a material of the same blend was effected with a dyestuff having the following structure:

An orange-brown shade print was obtained, for which the following characteristics were determined (the intensity being 1/2 E.C.E.): - coverage of the blend: good - setting: better than 90% - stability to dry/wet rubbing: 4 - 5/4 - stability to sunlight: 5 - stability to washing at 60"C: 3 - 4/4/4 The dyestuff was synthesised by a procedure analogous to that of example 1.

Example 7 Following the procedure described in example 1, a printing on a material of the same blend was effected with a dyestuff having the following structure:

An orange-yellow shade print was obtained, for which the following characteristics were determined (the intensity being 1/2 E.C.E.): - coverage of the blend: good - setting: better than 90% - stability to dry/wet rubbing: 4/3 - 4 - stability to sunlight: 5 - stability to washing at 600C: 4/4/4 - 5 The dyestuff was synthesised by a procedure analogous to that of example 1.

Example 8 Following the procedure described in example 1, a printing on a material of the same bend was effected with a dyestuff having the following structure:

An orange shade print was obtained, for which the following characterstics were determined (the intensity being 1/2 E.C.E.): - coverage of the blend: good - setting: better than 90% - stability to dry/wet rubbing: 4/4 - stability to sunlight: 5 - 6 - stability to washing at 600C: 4/4/4 - 5 The dyestuff was synthesised by a procedure analogous to that of example 1.

Example 9, 10, 11 & 12 (Comparative Tests) For comparative purposes, the following disazo pyrazolone dyestuffs having a shade ranging from yellow to orange and a structure similar to that of the dyestuffs according to this invention were applied under the conditions specified in the preceding examples. The attained results are grouped in the following order: coverage of the polyester-cotton blend; to of setting; stability to dry/wet rubbing; stability to washing at 600C; stability to sunlight. Blend Af- Stabi- Stabi- Stabicover- fi- lity lity lity age ni- to to to ty rub- washing sunbing at 60 C light

N, = I CON 0 N=NN=NMm CH2CH2 mean 60-65 4-5/4 2-3/4/1-2 4 10) HO o) o o so HO b oo cd d CO NH I o I 9 > e 4mp Z t X t Z?

Claims

WHAT WE CLAIM IS:

1. Disazo dyestuffs conforming to the general formula (I) hereinbefore defined.

2. Disazo dyestuffs according to claim 1, of the formulae set out in examples 1 - 8.

3. A method of making disazo dyestuffs as set out in claim 1, in which an amine of formula (II) hereinbefore defined is diazotized in an acid medium, the resulting disazo compound is coupled with a 1-phenyl-5-pyrazolone-3-acetic acid derivative of the formula (III) hereinbefore defined, and the resulting disazo compound is condensed with an amine of the formula (IV) hereinbefore defined.

4. A process according to claim 3 in which the condensation of the disazo compound with the amine of formula (IV) is effected in the absence of solvent.

5. A printing paste comprising a disazo dyestuff according to claim 1 or 2, or one prepared according to claim 3 or 4, dispersed in finely divided form in a medium comprising water, a solvent boiling above 1500C and a dispersing agent.

6. A paste according to claim 5 wherein the solvent is a polyol, a polyol ether or an organic acid ester.

7. Yarns comprising water-swellable cellulosic fibre dyed or printed with a paste according to claim 5 or 6.

8. Yarn comprising water-swellable cellulosic fibre dyed or printed with a disazo dyestuff according to claim 1 or 2.

9. Yarn according to claim 7 or 8 being a cotton/polyester or a rayon/polyester blend.