US1782122A - Vat assistant for use in dyeing - Google Patents

Description

Patented Nov. 18, 1930 UNITED STATES PATENTOEFlCE JEAN GEORGES AND CHARLES J. SALA, OF WILMINGTON, DELAWARE, ASSIGNOBS TO E. I. DU PONT DE NEMOURS & COMPANY, 01'' WILMINGTON, DELAWARE, A COR- PORATION OF DELAWARE VAT ASSISTANT FOR USE IN DYEING No Drawing. Application filed August 4, 1927. Serial No. 210,715.

It is essential that: all during the dyeing- This invention relates to the art of dyeing operation the dye be kept in its most highly and more particularly to the preparation and application to cellulose or artificial silk fabrics of a dyeing 'bath containing a material adapted to facilitate the dyeing operation. The invention also relates to the dyeing liquor and to the fabric dyed therewith as articles of manufacture.

As is well understood in the art, by the term vat dye is meant a coloring matter insoluble in water but which can be converted on'reduction into a so-called leuco-compound which is soluble to a certain extent'in solutions of alkali. Such vat dyes are characterized by their excellent fastness but the diificulty of dyeing them satisfactorily with fair yield has been a drawback to their use in this connection. One of the objects of the present invention is to overcome this difficulty in the manner described in detail below.

In dyeing with vat colors ascarried out at present several processes are followed:

1. On iece goods.

(1. igger dyeing method.

b. Padding method in reduced bath.

0. Padding method in unreduced bath with subsequent development of the dye in jigger. This rocess is the most usually adopted.

2. Dyeing of raw-stock, unspun cotton, in

machine. I

3. Dyeing of yarn on beams or packages in machines.

In general this invention relates in all or some of its improvements to the operation of d eing cotton or artificial silk. fibres in any 0 these ways. I w

Most of these processes require the use of a reduced bath. To undergo this operation the vat dyestufl is generally passed through a fine screen (200 mesh/inch) diluted some-.

what with water and added to the dyebath containing a corresponding amount of alkali and a reducing agent such as sodium hydrosulfite, which is the most commercially used.

The tem era-ture is raised for this purpose to a suita le point according to the particular vat dyestuff used and when complete reduc tion is reached the dyeing operation is started.

dispersed state.

Therefore, it is first of all important that the dyestufl paste be of special fineness but even with the finest pastes at present in commerce a great deal of color is lost because of its failure to dye the fibre. This wasted dyestulf is, in many cases not taken up by the fibre, and washes off during the soaping operation which follows the dyeing. Also, in most cases the great affinity of the reduced dyestufi itself for the fibre is a handicap to producing even dyeings.

,Now we have found, however, that certain organic compounds, when mixed either with; the dyestufi paste or when dissolved in the dyebath, produce Various improved results. These organic compounds are not in themselves new but it is believed that the use of them for this'purpose is entirely new. The compounds we employ are substituted aliphatic amines containing hydroxyl groups in the aliphatic radicals. They are very strong-' R R representin either an a 1 cup C H(2 +1) hydrogem or a hydroxy a l k yl goup It makes lpo difference. whether R is hydrogen while is an alkyl group or R is hydro en and R an alkyl group. Also any one 0 these substituents alread described may be' replaced by a compoun containing the group GQH (OH) In carrying our invention into effect we can proceed in two wa s.

1. We may mix the ingredient adopted to facilitate the dyeing operation into the vat color paste, dilute somewhat with water, and pass this suspension through a screen as described above. This suspension which is ve highly dispersed is then added to the dyebat containing the alkali'and the reducing agent;

The temperature is then brought to about the appropriate dyeing temperature at the start. A complete reductlon followed by a complete solubilization of the leuco is the result. The chemical process is not essentially different from one method to the other, except when pad-method is used. In this case the unreduced dyestufi is mixed with the assistant as outlined above then diluted to a certain concentration with water, gum and oil, the material padded therewith and dried and later developed on a jigger in a solution as described above and composed of alkali and a reducing agent. Additional dyestufi' may or may not be added in this case.

After the dyeing operation which takes about 45 minutes the material is rinsed and treated with an oxidizing agent such as bichromate of soda, or preferably perborate of soda, rinsed and thoroughly soaped, then again rinsed, allowed to dry and finished.

The presence of the new assistant very effectively aids the transfer of the dye to the cotton and a number of advantages are obtained.

2. We may also use the vat color pastes prepared in the manner described in our copending application, Serial No. 167,066,

- which pastes already contain the new assistant, the dyeing process being hence not different from the ordinary vat color dyeing processes, with the exception that the results are obtained as according to the present invention.

In order fully to disclose our process the following examples of typical dyebaths and methods are furnished. 4

It is to be understood, however, that these examples are only illustrative and that the conditions, proportions and reagents specified therein may be varied within wide limits, that is EXAMPLE I An 8 shade of Ponsol blue GD (Schultz #842) on 150 lbs. of mercerized cotton piece goods is obtained as follows: 12.75 lbs. of Ponsol blue GD (Schultz #842) are mixed with 8.16 lbs. of the new dye assistant 1 gal. of cold water added and the suspension passed through a fine screen. A perfect speckless paste is so obtained which is added to the jigger dyebath, composed of the following: lbs. caustic soda lbs. hydrosulfite conc. 10 lbs. added immediately, 5 lbs. after 1 passage. 100 gals. water.

The temperature raised to 110 F., and after complete reduction the dyeing started at this temperature. The temperature is then allowed to rise during 30 minutes to 125 F., and further dyed at this temperature for 10 to 15 minutes. Then give I wash, 4 passages in sodium perborate, 2 lbs. per 100 gals. at 120 F., 2 cold washes, 5 passes in boiling soap solution 3 lbs. soap to 100 gallons, then rinse and wash in the open, dry and calender.

When using the dyestuif pastes according to our co-pending application, Serial No. 167,066, where the assistant is already in the color paste, the foregoing example is simplified to the extent indicated by the following process.

EXAMPLE II An 8 shade of Ponsol blue GD pre- I 10 lbs. caustic soda (dry) 15 lbs. sodium hydrosulfite to 100 gallons bulk and the dyeing process carried out as described above.

EXAMPLE III Paddingdigger dyeing method The padding liquor is composed of:

5 lbs. Ponsol blue GD prepared according to said co-pending case and containing 64% of the new assi-stant.

11 gals. water 8 ozs. gum tragacanth 5 lbs. bleaching oil 12% gallons bulk The squeeze of the pad roller is about 60%.

The padded material is then dried and developed in a jigger according to the process of Example II above, by adding an additional quantity of the dyestufl paste so as to have an 8 dyeing.

The developing bath contains the same ingredients in the same quantities as under Example II, the dyeing being carried on underthe same conditions. This process oiiers the advantage of better penetration and 1s usually adopted in the mills. p

This process may be changed also as follows:

EXAMPLE IV The pad liquor is composed of: 5 lbs. Ponsol blue GD (Schultz #842) EXAMPLE V Package process:

% shade of Ponsol dark blue BR (Schultz #763) or violet RRD (Schultz #7 66) The boiled ofl' yarn is dyed in the package machine with 5% of vat color paste 3% sodium hydrosu 3% assistant water y The conditions of dyeing are the same as usual After d eing rinsr and oxidize with 2% sodium perh 2 caustic soda (drlyh) If the vat color pastes prepared according to our co-pending case above are used, the

above formula is modified as follows: 5% dyestuff prepared according to said copending application. 2%% caustic soda 3% sodium hydrosulfite ater' The shades come out bright and very even.

It is obvious that the preparing of the dye liquors from all the ingredients used may be varied by the dyer.

Advantages and results from the use of these assistants, either by direct addition to the dyebath or by preliminary addition to the vat dyestufi' pastes:

1. The exhaust of these dyebaths are much better than those used at present, which accounts for an i creased yield in depth of 2. The effect of the assistant as an excellent solvent is shown in slowing down the rate at which the dye goes on, which results in equalizing the depth of dyeing giving, in

this way, extremely even results. 7 This is of very great advantage for dyes having great afiinity such as blue GD, violet'RR blue 3 BCS, dark blue BR, etc.

3. The fixation of the dyestufl' is improved over the results of the usual methods, therefore, on s'oaping in .a boiling soap solutionthe dyestufi' loses less which accounts for an increased yield in shade (depth).

4..Due to brilliancy of the dyeing is enhanced.

5. It. is well known that most of the dyes,

. when being treated with a soap solution change considerably in shade. This is the case, for example, with the indanthrene blues (Schultz #842) but when dyed according to this method, additional soaping does not change the shade to any noticeable extent.

6. The addition of the assistant to the dyestuff paste puts the latter in a perfectly dispersed condition permitting a much quicker screening (several hours economy in time) I and permitting the padding of speck free paste which is of enormous value is specky dyeings orate, rinse, soap, rinse andmg with the vat color perfect dyeing conditions the an absolutelytion causes the dyer considerable trouble which is avoided by this invention.

8. The addition or presence in the vat paste 6 of such assistant is particularly of great assistance when dyeing with vat dyestufl's of the very insoluble type such as the highly chlorinated indanthrene blues, etc. It always insures a perfect solution, regulatesthe exhaust'and results in a very level (1 eing.

As many apparently widely di erent embodiments of this invention may be made without departing from the spirit thereof, it is to be understood that we do not intend to limit ourselves to the specific embodiments thereof except as indicated in the appended claims.

We claim: 1. The processof improving a vat color paste, the step which comprises incorporating with the vat color paste a compound having the structural formula:

group O IL h drogen, or the hydroxy alkyl group C H gH.

he process of improving a vat color paste, the step which comprises incorporating with the vat color paste a compound of the type described in claim 1, in which compound C H OH represents the radical C H OH.

3. The process of improving a vat color paste, the step which comprises inco rating the structural formula: 1

.Ha- N- l R- wherein' C.H,,,OH represents an aliphatic: 'radical, substituted or not, and R and R,

represents either hydro en or an aliphatic radical or a hydroxy-ahphatic radical.

4. The. process of improving a vat color paste, the step which comprises incorporatmg with the vat color paste a compound of the type described in claim 3, wherein R represents a hydro -aliphatic radical.

5. The process 0 improving a vat color paste, the step which comprises incorporatmg with the vat color paste a compound'of the type described in claim 3, wherein IL wherein R R, represents" either the alkyl pastea compoun havalkyl group canon represents a hydroxy-aliphatic radical and R represents hydrogen.

6. The process of improving a vat color paste, the stepwhich comprises incorporating with the vat color paste a compound of the type described'in claim 3, wherein R re resents hydrogen.

The process of improving a vat color paste, the step which comprises incorporating with the vat color paste a compound of the type described in claim 3, in which -compound both C H OH and R represent the radical (LI-LOH.

8. In the process of dyeing with vat colors, the step which comprises incorporating in the vat a compound having the structural formula onnhon wherein R R represents group C H hydrogen,

either the alkyl or the hydroxy 9. In the process of dyeing with vat colors, the step which comprises incor orating in the vat a compound of the type escribed in claim 1, in which compound C 0 represents the radical 0 11 011.

10. In the process of dyeing with vat colors, thestep which formula O HInOH -R1 \R|- 1 wherein C H OI-I represents an aliphatic radical, substituted or not, and R and R represents either hydrogen or an aliphatic radical or a hydroxy-ali hatic radical.

11. In the process of yeing with vat colors, the step which comprises incorporating in the vat a compound of the type described in claim 3, wherein R represents a hydroxyaliphatic o radical.

12. In the process of dyeing with vat colors, the step which comprises incorporating in the vat a compound of the type described in claim 3, wherein R represents a hydroxyaliphatic radical and R represents hydrogen.

13; In the process of dyeing with vat colors, the step which comprises incorporating in the vat a compound of the type described in claim 3, wherein R represents hydrogen.

14. In the process of dyeing with vat colors, the step which comprises incorporating in the vat a compound of the type described in claim 3, in which compound both C H OH and R represent the radical C I-LOH.

In testimony whereof we aflix our signalures.

J EAN GEORGES KERN. CHARLES J. SALA.

comprises incorporating in the vat a compound having the structural Certificate Cerrect ion Granted November 18, 1930, to

Patent No. 1,782,122. I

JEAN GEORGES KERN ET AL.

' It is hereby, certified that error appears in the printed specification 0f the above numbered patentqeqniri-ng correction as follows: Page 1, line 90, strike out the formula and insert instead C H (OH) 5 page 3, lines 115 150117, strike out the formula and insert instead -NR and that the said Letters Patent should be read I 2 4 v with these corrections-therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 23d day of December, A. D. 1930.

[SEAL 7 I 1 a s M. J.'MOOR-E,

Acting Commissioner of Patents. I