US2174005A - Vat color printing paste - Google Patents

Description

Patented Sept. 26, '1939 2,174,095 VAT coLoa PRINTING PASTE Charles Franklin Miller, Wilmington, Del., as-

signor to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application October 29, 1938, Serial No. 237,759

4- Claims.

This invention relates to an improved process for printing textile fibers with vat dyes and to dye compositions especially adapted to this process.

More particularly it relates to the preparation and application to a fabric composed of either natural or synthetic cellulosic fibers of a printing composition containing a vat dye and a material adapted to facilitate the printing operation. The invention also relates to the vat dye color pastes or to vat dye powders and to the fabric imprinted therewith as articles of manufacture.

It is an object of this invention to provide an improved vat color printing paste, which has several distinct advantages over the customary printing pastes of this date, especially in respect to stability and to freedom from speckiness and scumming. Other and further important ob.- jects of this invention will appear as the description proceeds. v

By the term vat dye hereinafter we refer to dyes of the anthraquinone, indigo, and thioindigo series which are generally'applied to the fiberby a reduction process involving the use of alkaline hydjrosulfite or the group of formaldehyde-sulfoxy a es.

The printing of fabric with vat colors isa well known and highly developed art. It generally comprises dispersing the vat dye .in a thickening paste containing reducing agents, applying to the fabric by means of an-engraved roller, then exposing the fabric to the action of steam, which is known as ageing, to effect reduction of the colorand finally treating with a mild oxidizing agent,

and washing and soaping to remove the gum,-un-

fixed color, etc.

Quite-generally, special assistants are added to the dye composition or printing paste to facilitate the dispersion of the die, prevent drying out of' the paste, assist penetration of the'printing paste to the reverse side of the fabric, produce greater brilliance in the prints and produce more level prints on heavily pigmented rayons. But in spite of all the great advances that have been made in the vat color printing art, many problems remain to confront the printer: among them are the following:

(1) Many vat color printing pastes thicken and become too thick to use after standing for several days.

(2) Many vat color printing pastes tend to -liver" or separateinto a gum and a water layer on standing, which layers cannot be redispersed.

(3) Many vat color printing pastes tend to agglomerate and give "specky, weak printsif let stand several days. i

v (4) Many vat color printing pastes, particularly those containing special assistants to facilitate penetration of the printing paste to the reverse side of the fabric -and to improve the brilliance and levelness of the prints on heavily pigmented rayons or spun rayon fabrics, tend to reduce so rapidly either on standing several days or in the ymer of acetaldehyde; it corresponds to the formula CH3.CHOH.CH2.CHO and is described more fully in Beilstein, 4th ed., Vol. I, page 824. For the purpose of this invention, it may be added directly to the printing paste'as the latter is made up, or it may be incorporated first into, an assistant paste containing the vate dye, with or without supplemental reagents such as penetrating or levelling assistants, which assistant paste is then incorporated into the thickening paste in the usual manner, to produce the printing paste.

It is remarkable that acetaldol is unique in the above beneficial effect with-respect to the problems mentioned, inasmuch as. other aldehydes such as butyraldehyde and octyl aldehyde of the aliphatic series, sulfo-benzaldehyde, salicyl aldehyde and benzaldehyde of the aromatic series, and furfural of the heterocyclic series, are either inert in vat color printing pastes or else accelerate the thickening, livering and scumming, which are overcome by the use of acetaldol.

The amount of acetaldol necessary to produce the desired effects will vary according to the type of color used; local types of printing pastes employed'for thickening; and the amount and kind examples are given to illustrate my preferred mode of operation. Parts are by weight.

Pmem'rron or rm: Tmcxamna PASTES Thickening SBG 100 parts of wheat starch 300 parts of-British gum and 600 parts of water lOOOYparts 7 This mixture was-pasted to the boil, for 10 min- I utes and cooled to room temperature. A smooth paste was obtained.

Thickener A 560 parts of Thickening SBG were heated to 170 F. There were then added 170 parts of potassium carbonate. After the potassium carbonate had dissolved, the paste was cooled to 140 F. and the following ingredients added 120 parts of sodium formaldehyde sulfoxylate parts of glycerine 100 parts of water 1000 parts The whole was then stirred to form a smooth paste.

Example 1 20 parts of 5,7,5,7-tetrabrom-indigo (c. I. No.

1184) were mixed with 69 parts Thickener A, and to this were added 10 parts of a stable emulsion consistingol.

6.0 parts of Turkey red oil 3.2 parts of Assistant A, as defined below 0.8 part of benzyl alcohol 10.0 parts and 1 part of acetaldol 100 parts, total (Assistant A consists of a 30% aqueous solution of mixed sodium alkyl sulfates obtained by the sulfonation of a mixture of CB primary and C1 secondary monohydric' alcohols (B. P. 133 to 150 C.). These compounds are fully described in United States Patent No. 2,079,788.)

Piece goods variously prepared from lustrous rayon, titanium-dioxide delustered rayon, and

partially saponified acetate-process rayon, were printed with the printing composition prepared above, dried, and aged for 5 to 10 minutes at 214 F. in a rapid ager of the Mather-Flatt type. The printed material was then treated for '1 minute in an. oxidizing bath at 140 F; containing /g% of sodium bichromate and of acetic acid, rinsed in cold water, soaped for 5 minutes in a soap bath at 160 F. containing /g% of soap,

rinsed and dried.

The above described printing composition does not reduce as rapidly in the color box of the printing machine or in the printing-paste if .let stand several days as when the printing composition does not contain the acetaldol, and permits a materially longer run to be made without scumming. v

Example 2 100 parts of 6,6'-diethoxy-2,2'-bisthionaphthenindigo (C. I. No. 1217) were mixed with 40 parts of Assistant A (as described in Example 1) and 20 parts of Turkey red oil 160 parts, total. There were then evaporated 65 parts of water, producing 95 parts of assistant color paste; to this were added 5 parts of acetaldol, producing 100 parts of assistant color paste which was run through a colloid mill to secure a homogeneous mixture. 20 parts of the resulting paste were mixed with parts of Thickener A, as above described,

producing 100 arts, total, of printing paste.

Lustrous rayon piece goods and titanium-dioxide delustered rayon piece goods were printed with the printing composition described above and finished as described in the previous example to give a bright, highly penetrating, level orange 1 print.

The above printing composition can be kept several weeks without appreciable thickening, livering or agglomeration and does not reduce as rapidly as similar paste prepared without the acetaldol.

-' Ezrample 3 100 parts of the thioindigoid dye employed in 100 parts of assistant color paste.

The above composition was thickened as in Example 2, printed on cotton piece goods and on spun rayon. and finished as in Example 1, giving a bright orange printed design.

The above described printing composition can be kept several weeks without appreciable thickening, "livering, agglomeration or reduction,

whereas a similar composition prepared without the acetaldol agglomerates and gives specky" prints after standing several days.

Example 4 100 parts of the thioindigoid dye mentioned in Example 2 (C. I. No. 1217) were mixed with 20 parts of sodium butyl phthalate (Note A, be-

' low) 120 parts, total. There were then evaporated. 25 parts of water, yielding parts of assistant color paste to which were added 5 parts of acetaldol, producing parts of assistant color paste which was then milled in a. colloid mill to insure a. homogeneous mixture.

20 parts of the last mentioned assistant'color paste were mixed with e 80 parts of Thickener A, producing 100' parts of printing paste.

Lustrous, titanium-dioxide-delustered, and partially'saponified acetate rayons were printed with the above composition and finished as in Example 1, giving bright, highly penetrating, very level orange prints.

The above described printing composition can be kept several weeks without appreciable thickening or agglomeration and does not reduce as rapidly as a. similar paste prepared without the steam distilled to remove the excess alcohol, and

is then evaporated to dryness on the steam bath.

Example 100 parts of the indigoid dye used in Example 1 (C. I. No. 1184) were mixed with 25 parts of sodium-mathyl-pentanol-phthalate (Note A, above) 125 parts, total. There were then evaporated 27 parts oi water, producing 98 parts of color paste, to which were added 2 parts of acetaldol, producing 100 parts of assistant color paste, which was milled in a colloid mill to give a homogeneous mixture.

20 parts 01' the above described assistant color paste were mixed with I 80 partsof Thickener A, producing 100 parts of printing paste.

containing the phthalate but no acetaldol, and

has less tendency to "scum in a printing machine.

In the above examples the dyestuii may be re placed by. other vat dyes of the indigoid, thioindigoid or anthraquinone series as for instance:

' Dimcthoxy-dibenzanthrone C. I. No. 1101 3,3'-dichloro-indanthrone C, I. No. 1113 6,6'-dibrorno-4,4' diniethyl -2,2'-

and numerous others.

I claim:

1. A composition of matter for printing textile fiber comprising a vat dyestufl and acetaldol.

2. A composition of matter for printing textile fiber comprising a vat dyes'tufl, a thickening agent, a reducing agent, an alkaline agent, and acetaldol. 5

3. A process of printing cellulosic textile fabric,

. which comprises applying thereto a printing paste comprising a. vat dyestufl, a reducing agent, an alkaline agent, a thickening agent and'acetaldol.

4. A process of printing cellulosic textile fabric, which comprises applying thereto aprinting paste comprising a vat dyestuit, sodium formaldehyde sulfoxylate, potassium carbonate, starch- British gum thickening, and acetaldol, the quantityof acetaldol being from V to 2% by weight of the entire compositions and then subjecting the fabric to steam ageing, oxidation and soaping'