US2046425A - Process of producing azo dyestuffs on the fiber - Google Patents

Description

Patented July 7, 1936 UNITED STATES PATENT OFFICE 2,046,425 rnoonss 0F PRODUCING AZO nrns'rurrs ON THE FIBER.

tion of Delaware No Drawing.

Application September 15, 1932,

Serial No. 633,376. In Great Britain September 25, 1931 3 Claims.

The present invention relates to a process of producing azo-dyestuffs on. the fiber, more particularly it relates to improvements in threing fibers, yarns and fabrics with azo-dyestufis.

In the usual method'of producing azo-dyestufis on the fiber, the material is impregnated with a solution ofthe substantive coupling component or passive component", such as an arylide of 2.3-hydroxynaphthoic acid, acetoacetic acid, 2-

hydroxyanthracene-3-carboxylic. acid, ortho-hyweight, takes place rather slowly and incomplete-. When using inly under the usual conditions. the usual method a diazo-compound which couples slowly it can be observed that, due to the incomplete coupling, in the after-treatment of the dyeings, particularly in the soap bath, part of the diazo-compound which has noteoupled is dissolved from the material.

Most diazonium salts are somewhat unstable except at very low temperatures. Some of the passive components also, such as the alkali metal salts of 2.3hydroxynaphthoic acid arylamides, commonly known under the name naphtholates, are not wholly stable under the conditions of coupling. Therefore, if the time of coupling is unduly prolonged, decomposition may take place with the production of undesired by-products.

The disadvantage is particularly annoying in the production of resist articles: The-unchanged diazo-compound which comes oil in the soap bath, often reacts with the coupling component present on those parts of the material where the resists (white or. colored resists) were applied, thus staining or coloring. the reserved parts.

We have now found that the rate of coupling is greatly accelerated by increase in temperature and that notwithstanding the higher degree'of instability exhibited by the reagents, such as the diazonium salt, at these higher temperatures, improved results, such as much more completely coupled and darker dyeings, may be obtained by performing the coupling at elevated temperatures. It is necessary, of course, that the diazonium salt and the passive components shall be in intimate contact in the correct proportions for reaction when the temperature is raised to accelerate the coupling. The process according to the present invention, therefore, consists in impregnating the goods with a passive component and with a solution of a diazonium salt in the correctproportions for coupling and then raising the temperature rapidly to a value substantially above atmospheric temperature. The acceleration of the coupling is progressive with rise of temperature but, generally speaking, temperatures above 50 C. and preferably round about to C. are desirable. Preferably, the impregnation is performed at a sufiiciently low temperature to retard decomposition of the reagents.

The goods are most suitably impregnated with the passive component, such as an arylide of 2.3- hydroxynaphthoic acid or other suitable substantive coupling component, passed through a diazonium solution and then subjected to a heating operation. Thus they may, immediately after the impregnation, be dried by passing them over drying tins. Such method of drying involves heating very rapidly to temperatures round about 100 C. and under these circumstances the coupling takes place in time of the order of a few seconds.

Or the material after impregnation with the coupling component and treatment with the diazo solution is immediately passed through a heated space, for instance, through a steamer or through the space between heated plates.

The dyeings obtained by operating in accordance with the present invention are usually darker, in some cases they are 30 to 40 per cent stronger, than those obtained by the known processes, probably owing to the smaller amount of decomposition of thecomponents. There is less risk of injury to the goods from soiling by decomposition products. 4

An important advantage of the present inven tion is that mixtures of different diazonium salts and salts which are ordinarily too slow in coupling to be dyed continuously or are not. sumciently soluble, may be utilized" satisfactorily, by operating according to the method of the present invention.

The process of the present invention also is of advantage in the production of resist efiects, since a considerable amount of organic acid may be employed in the diazonium solution without injuriously affecting the coupling processes.

For performing the coupling at elevated temperatures there may be used the usual drying tins or other suitably heated cylinders.

If instead drying over tins it is preferred to use a steaming apparatus, there may be used the usual construction, for instance, an apparatus provided with perforated steam-pipes and with guide rollers for the material. Another modification of carrying out the coupling at elevated temperatures is the use of heated plates, for instance, of flat hollow plates of iron or other metal, electrically heated plates or other suitably shaped heating devices. The-heating plates are arranged in pairs facing each other at a suitable distance apart, so that there is a heated space between them through which the material is conducted.

Such use of heating plates is of advantage, for instance, in the production of resist articles. It is easily possible to arrange the heating plates and the guide rollers for thematerial in such a manner that the material, on its way from the diazo bath to the washing machine, is in contact with rollers only on its reverse (unprinted) side. This avoids removal of the printed resists from the material, as is possible, for example, if the printed side of the material is in contact with the rollers.

' The new process may advantageously be ap- 'plied to the production of dyeings on the fiber in the case of all slowly coupling diazo-compounds. Slowly coupling diazo-compounds are, for instance, those of bases of the general formula:

wherein R1 means a substituted or unsubstituted aromatic radical and R2 a substituted or unsubstituted iso-cycli'c radical.

= An exhaustive description of all possible slow- .iy coupling diazo-compounds is not necessary,

subjected .to a heating operation. The inven-' tion is not limited to a particular heating device. Instead of drying tins, steaming apparatus or heated plates or any other suitable construction may be used. I

The following examples serve to illustrate the invention, but they are not intended to limit it thereto:

-' (1) A fabric of cotton impregnated with 1% of 2".3-hydroxy-naphthoyl-aniline in the usual manner is padded in a diazo-solution containmg:

3% of diazonium chloride of 4;amino-4'-methoxy-diphenylam'ine,

5% of Epsom salt (magnesium sulfate),

- 1% of formic acid, dried over tins and soaped. a

(2) A fabric prepared in 2%% 2'.3'-hydroxynaphthoyl-2.5-dimethoxy-l-aminobenzene in the usual manner is passed through a suspension of 7% of zinc chloride double salt of the diazo compound of a-amino-anthraquin'one,

/z% of tragacanth, 1

1% of acetic acid, dried over heated cylinders and soaped.

- (3) Upon a fabric prepared in 2% 2'.3'-hydroxynaphthoyl-4-chloroaniline in the usual manner, is printed a resist consisting of 20 parts by wei ht of sodium sulfoxvlate,

parts by weight of British gum thickening. The fabric is then padded through a diazo-solution prepared in the usual manner, containing:

2% of 4.4-diaminodiphenylamine,

1% of formic-acid, dried at elevated temperature and washed. A white resist is obtained upon a navy ground.

(4) A fabric prepared in 2% of 2'3'-hydroxynaphthoy1-2.5 dimethoxy l aminobenzene is padded through the nip in a diazo-solution con- 10 taining:

1% of 2.5-dichloroaniline,

0.75% of 4.4'-'diamlnodiphenylamine, and dried at elevated temperature. The goods are soaped in the presence of one-quarter per 15' cent of caustic'soda at the boil, when a brown shade is obtained.-

ner by passing the fabric over, drying tins which are steam heated. Preferably the temperature of the tins, or at least of those over which the fabric first passes, is just below that which would cause the liquid upon the fabric to dry. The numberof 25 tins and their preferred temperature is dependent upon the nature and weight of the fabric and the weight of liquor therein. With a fabric weighing 30 lbs. for 120 yards and" taking out 28 lbs. of liquor per piece, 24 tins each of 18 inches diame- 30 ter are suitable. All are steam heated, the last 20 at about 2 or 3 lbsxexcess pressure.

(5) (a) Grounding liquor 12 grams of 2'3-hydroxynaphthoyl-aniline are p made into a paste with 1 15, cc. of Turkey red oil and 15 cc. of caustic soda solution of 38 136., the

whole is dissolved with boiling water and made. up with water to w 40 1 liter Temperature of the grounding bath: 35 C. The material is grounded on a foulard and dried in the hotflue.

(1;) Developing bath 27 grams of diazonium chloride of -amino- 4' methoxy diphenylamine are made up with of cold water to 1 liter Temperature of the developing, bath: 15 C. to :55 20 C. The grounded and dried material is developed on a two-roller-foulard and immediately-without exposureto air-passed through a steamer. The steaming temperature is about C. to C. and the time of steaming about 60 30-seconds. Thereupon, the material is passed through a bath at 40 C. containing 5 cc. of hydrochloric acid of 20 per liter, rinsed and soaped-at boiiingteniperature.

(6) The material which has been grounded and 35- dried as indicated in Example 5 is printed with the following white resist:

250 grams of aluminium sulfate 1:1 500 grams of starch tragacanth thickening, 100 grams of kaolin powder,

grams of water.

Instead of using a steamer, the material may be passed through the space between heated plates arranged in pairs facing each other at a suitable distance apart, for instance, fiat hollow iron plates heated by means of steam. Thereupon, the goods are passed through a bath at 80 0., containing 30 cc. of hydrochloric acid of 20 B. per liter, rinsed in cold water, passed through a bisulfite bath of 80 C. containing 15 cc. of sodium bisulfite solution of 38 B. per liter, rinsed and soaped. A white resist is obtained upon a blue ground.

(7) Grounding liquor: as indicated in Example 5.

Yellow resist 80 grams '70 grams 205 grams 400 grams grams 10 grams 120 grams paste 50 grams 1000 grams Development and further treatment as indicated in Example 6. A yellow resist is obtained upon a blue ground.

(8) Grounding liquor: as indicated in Example 5.

Green resist grams of the sulfuric acid ester salt of the leuco compound of dimethoxydibenzanthrone,

Development and further treatment as indicated in Example 6. A green resist is obtained upon a blue ground.

We claim:

1. In the process of producing azo-dyestufis on the fiber by impregnating the material with a s0- vlution of a substantive azo-component and subsequent developing in a solution of a slowly coupling diazo-compound, the step which comprises subjecting the material, immediately after the treatment with the diazo bath, to a dry-heating operation at a temperature of about C. to about C.

2. In the process of producing azo-dyestufis on r the fiber by impregnating the material with a solution of a substantive azo-component and subsequent developing in a solution of a slowly coupling diazo-compond, the step which comprises subjecting the material, immediately after the treatment with the diazo bath, to a steaming operation.

3. In the process of producing azo-dyestufi's on the fiber by impregnating the material with a solution of a 2.3-hydroxy-naphthoic acid arylide and subsequent padding in a solution of a diazonium salt of a base of the general formula:

wherein R1 means a substituted or unsubstituted aromatic radical and R2 a substituted or unsubstituted isocyclic radical, in the correct proportions for coupling, the step which comprises subjecting the material, immediately after the treat ment with the diazo bath, to a rapid heating operation in the neighborhood of 100 C. to 110 C.

CHARLES SCHWABE PARKER. CHARLES LEONARD WALL. FRANKLIN FARRINGTON.

Developing bath 80 grams of a mixture of ethyleneglycol, di- 27 grams oi! diazonium chloride of 4-aminohydmxy ethylene glycol and 4' methoxy diphenylamine are monomethylether' 1'75 grams of water made up with 973 cc of c 01 d water to 400 grams of starch-tragacanth thickening, 80 grams of sodium bisulfite of 38 B.,

1 liter 15 grams of ammonium thiocyanate, v 120 grams of chrome yellow, 60% paste (neu- The material is developed on a two-roller-foutral lead chromate). lard and immediately passed through a steamer. 50 grams of kaolin paste 1:1, The steaming temperature is about 110 C. to C. and the time of steaming about 30 seconds. 1000 grams