Disperse Or Monosulfonated Acid Dye Printed Nylon Resisted With Hydroxy Diaryl Sulfone-formaldehyde Condensate

Abstract

A process for printing synthetic nitrogenous fibers with dyestuff that are soluble or dispersible in water is disclosed. The fibers to be printed are pretreated with an aqueous preparation consisting substantially of at least one fiber, substantive water-soluble, anionic resist for synthetic polyamide fibers selected from the group consisting of polycondensates of diarylsulfones containing at least one phenolic hydroxy group with formaldehyde. The fibers so pretreated are then dried and then printed with the printing paste containing the dyestuff.

Description

The present invention provides a process for printing nitorgenous fibers with dyestuffs that are soluble or only dispersible in water. According to the present process the fibrous material is pre-treated with an aqueous preparation containing at least one fiber-substantine resist for synthetic polyamide fibers. The impregnated material is then dried and printed in the usual manner.

Nitrogenous fibers suitable for printing by the present process are above all those of synthetic origin. Particularly good results are obtained on synthetic polyamides, such as condensation products from adipic acid and hexamethylenediamine, polycondensates of .epsilon.-caprolactam or of .omega.-aminoundecanoic acid. The fibers may be in any desired stage of their processing, that is to say they may in the form of filaments, staple fibers, textured fibers, combings, fabrics or hosiery.

The dyestuffs must be soluble or at least dispersible in water. Particularly valuable are the water-soluble dyestuffs, for example substantive dyestuffs, l:1-metal complex dyestuffs, and especially metal-free acid wool dyes and 1:2-metal complex dyestuffs. As dyestuffs that are only dispersible in water there are suitable, above all, the so-called disperse dyestuffs, for example those of the type of the 1:2-metal complex dyestuffs. The term disperse dyestuffs refers to those organic, coloured compounds of which at most traces are soluble in water so that they must be applied in the form of fine dispersions.

The printing pastes used for the application of the dyestuffs defined above contain the conventional additives, such, for example, as thickeners, hydrotropic agents, solution promoters and the like. As a rule, the dyestuffs are fixed by steaming.

Fiber-affinic resists for synthetic polyamide fibers are compounds that prevent the fibers being stained by the dyestuff, either during dyeing or during washing. Such compounds are as a rule water-soluble, anionic and as such known. They should have no color of their own, or at least they should not change the color of the fibrous material under treatment. Thus, for example, a list of such compounds will be found in "Vorbehandlung und Farben von synthetischen Fasern" by H.U. Schmidlin, 1958, but this list of course does not claim to be complete, and the present invention is not limited to the use of the compounds listed.

Of special value are water-soluble anionic polycondensates of formaldehyde with diarylsulphones that contain at least one phenolic hydroxyl group. As aromatic components there are suitable dicyclic and especially monocyclic compounds containing at least one phenolic hydroxyl group. However, in addition to the hydroxyl group other substitutents may be present, such as sulphonic acid groups, halogen atoms or alkyl radicals, especially alkyls containing one to four carbon atoms. Particularly suitable are compounds of the type of the phenol, of the mono-alkylphenols or dialkylphenols, for example of the cresols or xylenols, of the mono- or di-halogenophenols, for example of the chlorophenols or dichlorophenols, or resorcinol or of pyrocatechol.

The sulphones are prepared from the phenolic compounds referred to above by known methods, for example by reaction with sulphuric acid at an elevated temperature. In this connection it is also possible to use mixtures of the aromatic components defined above.

These sulphones are subjected to polycondensation with formaldehyde in known manner, for example in an acidic or alkaline medium at an elevated temperature. However, it is not necessary to perform the condensation exclusively with sulphones and it may be performed also with mixtures of sulphones and sulphonic acids of the phenolic compounds described above. If this is the case, the polycondensate should contain at least 30, preferably at least 40, mol percent of sulphone. When, on the other hand, exclusively sulphones are subjected to the polycondensation, the sulphones are sulphonated either before the condensation or after it in the form of the polycondensates. In this reaction it is possible to introduce sulphonic acid groups either before or after the condensation with formaldehyde. The polycondensates of sulphones, whose aromatic hydroxy compounds are phenol, cresols or xylenols, are specially preferred because of their accessibility and their potency.

These resists are applied during the pretreatment according to the padding or preferably the exhaustion method, using temperatures from 10.degree. to 130.degree. C., preferably from 80.degree. to 100.degree. C. The fibrous material thus treated is then dried. The pH values of the aqueous preparations may be in the acid, neutral or alkaline region, but preferably they are acid, in fact in the pH region from 3 to 5, or neutral. The acid pH value is produced by adding inorganic, or preferably organic, acids of low molecular weight.

The amount of resist to be used varies within wide limits and is in the padding process 0.1 to 10 percent referred to the padding liquor, or 0.1 to 10 percent, preferably 0.5 to 3 percent, referred to the fibrous material when working by the exhaustion method.

Apart from the resist the preparation may also contain optical brighteners, bleaches, for example reducing agents, or other usual additives.

The advantage of the present process is that owing to the pretreatment a smaller quantity of resist is needed than when the resist is added to the washing liquor. As a result of this addition the white ground of the fibers is not stained by unfixed dyestuff during the washing operation.

Parts in the following Examples are by weight.

EXAMPLE 1

Textured hosiery from an adipic acid/hexamethylenediamine condensate is treated. The treatment takes 30 minutes. The liquor has a goods-to-liquor ratio of 1 : 40, a temperature of 80.degree. C., a pH value of 3.5 (adjusted with acetic acid) and contains 2 percent, referred to the weight of the fibers, of the polycondensate, described below, of a phenol/sulphuric acid reaction product with formaldehyde. The material is then rinsed for a short time and dried.

The goods thus pretreated are then printed with a printing paste consisting of

30 parts of the dyestuff c.I. Acid Orange 47 of the formula ##SPC1##

50 parts of thiourea

50 parts of thiodiethyleneglycol

510 parts of water

300 parts of a 12 percent aqueous solution of a commercial, modified locust bean gum

60 parts of ammonium tartrate solution of 15.degree. Be.

The printed material is dried and steamed for 20 minutes in a conventional ager at 102.degree. C., then rinsed in cold water, washed in a bath heated at 50.degree. C., containing in 1,000 parts of water 2 parts of any desired synthetic detergent, and once more rinsed for a short time in cold water. A brilliant orange print is obtained. The unprinted areas remain white, whereas when a print that has not been pretreated is washed, the white areas display a distinct, undesirable coloration.

PREPARATION OF THE RESIST

50 Grams of concentrated sulphuric acid are stirred dropwise at room temperature into a suspension of 100 g. of 4,4'-dihydroxydiphenylsulphone in 50 g. of acetic anhydride. The temperature is then raised to about 100.degree. C., and after 6 hours 300 ml. of water are added portionwise, while at the same time 311 ml. of liquid are distilled off under reduced pressure. The residual reaction mixture is mixed with a reaction mixture obtained in the manufacture of ortho-cresol-4-sulphonic acid from 64.9 g. of ortho-cresol in 75 g. of acetic anhydride with 75 g. of concentrated sulphuric acid. Then 80 g. of 30 percent aqueous formaldehyde solution are added to the mixture of these two reaction mixtures. The whole is heated for 5 hours at 100.degree. to 105.degree. C. and then allowed to cool. The thickly liquid condensation product, 40 mol percent of which consist of 4,4'-dihydroxydiphenylsulphone-3-sulphonic acid and 60 mol percent of ortho-cresol-4-sulphonic acid, is then treated with 30 percent sodium hydroxide solution until a pH value of 7 has been reached. The resulting product can be diluted with water in any desired proportion.

A product having similar, good properties is obtained with a suspension of 200 g. of 4,4'-dihydroxydiphenylsulphone in 100 g. of acetic anhydride is sulphonated with 100 g. of concentrated sulphuric acid, 300 ml. of water are added and 283 ml. of liquid are distilled off. When this reaction mixture is mixed with the reaction mixture obtained in the manufacture of ortho-cresol-4-sulphonic acid from 21.6 g. of ortho-cresol in 25 g. of acetic anhydride with 25 g. of concentrated sulphuric acid, and the two components are condensed with 80 g. of 30 percent aqueous formaldehyde solution, a product is obtained of which 80 mol percent consist of sulphone.

EXAMPLE 2

Textured hosiery from polyamide 6.6 is impregnated on a padder to a weight increase after squeezing of about 90 percent with a preparation containing in 1,000 parts of water 20 parts of the resist described below, and the material is then dried at 80.degree. C.

The material thus pretreated and dried is then printed with a printing paste consisting of

30 parts of the 1:2-chromium complex of the dyestuff, prepared according to U. S. Pat. No. 2,565,895, and of the formula ##SPC2##

50 parts of thiourea

50 parts of thiodiethyleneglycol

510 parts of water

300 parts of a 12 percent aqueous solution of a commercial, modified locust bean gum

60 parts of ammonium tartrate solution of 15.degree. Be.

The printed hosiery is dried and steamed for 20 minutes at 102.degree. C. in a conventional ager, then rinsed cold, washed at 60.degree. C. in a bath containing in 1,000 parts of water 2 parts of any desired synthetic detergent, and once more rinsed in cold water. A scarlet print is obtained and the unprinted areas remain white, whereas a print that has not been pretreated displays distinctly coloured white areas after washing.

MANUFACTURE OF THE RESIST

Thirty-five grams of concentrated sulphuric acid are stirred at room temperature dropwise into a suspension of 70 g. of 4.4'-dihydroxydiphenylsulphone in 35 g. of acetic anhydride. The temperature is then raised to 98.degree. to 100.degree. C. and maintained at this value for 6 hours. 75 ml of water are then added portion wise under a pressure of 30 to 50 mm. Hg, and at the same time 88 ml. of liquid are distilled out of the reaction mixture. The residual reaction mixture is diluted with another 20 ml. of water, mixed with 20 g. of 30 percent aqueous formaldehyde solution and the whole is heated for 5 hours at 100.degree. to 105.degree. C., then allowed to cool, and 30 percent sodium hydroxide solution is added to the thickly liquid condensation product until a pH value of 7 has been reached. The resulting product can be diluted with water in any desired proportion.

A product having similar properties is obtained when the reaction mixture is adjusted to a pH value from 8 to 8.5 by means of 30 percent sodium hydroxide solution before the formaldehyde is added.

EXAMPLE 3

Warp hosiery from polyamide 6 is pretreated as described in Example 1.

Similar, advantageous results are obtained by printing with a printing paste prepared as described in Example 1 but containing instead of the dyestuff mentioned there:

30 parts of the 1:1-chromium complex of the dyestuff of the formula ##SPC3##

30 parts of the 1:2-chromium complex of the dyestuff of the formula ##SPC4##

Claims

We claim:

1. A process for printing synthetic nitrogenous fibers with dyestuffs with no more than one sulfonate group, which dyestuffs are soluble or dispersible in water which comprises pretreating the fibers to be printed with an aqueous preparation consisting substantially of at least one fiber-substantive, water-soluble, anionic resist for synthetic polyamide fibers selected from the group consisting of polycondensates of diarysulfones containing at least one phenolic hydroxy group with formaldehyde, whereupon the fibers so treated are dried and then printed under textile printing conditions with the printing paste containing the dyestuff.

2. A process according to claim 1, wherein synthetic polyamide fibers are printed.

3. A process according to claim 1, wherein the fibers are pretreated by the exhaustion method in an acid bath having a temperature of 80.degree. to 100.degree. C.

4. A process according to claim 3, wherein the pH-value is from 3 to 5.

5. Process according to claim 1, wherein the diarylsulfone is made from monocyclic hydroxyaryl compounds.

6. Process according to claim 5, wherein the diarylsulfone is a dihydroxydiphenylsulfone.

7. Process according to claim 1, wherein the polycondensates consist of dihydroxydiphenylsulfones and hydroxybenzene sulfonic acid the content of sulfone being at least 30 mol percent.

8. Process according to claim 1, wherein the polycondensates consist of sulfonic acids of dihydroxydiphenylsulfones.

9. Process according to claim 1, wherein the dyestuffs are acid, metal-free wool dyes.

10. Process according to claim 1, wherein the dyestuffs are water-soluble 1:2-metal complex dyestuffs.