US2201042A - Reducing composition useful for textile printing, dyeing, and other purposes - Google Patents

Description

Patented Mhy 14, i940 REDUCING COMPOSITION USEFUL FOB TEXTILE PRINTING, DYEING, AND OTHER 7 PURPOSES Jacob Katz, Providence, a: 1., assignor to Warwick-hemioal Company, West Warwick, R. I., acorporation of Rhode Island Noni-swing. Application August 29, 1939, Serial Nr 292.411

14 Claims.

The present invention relates to reducing compositions and particularly relates to reducing compositions which may be utilized in connection with textile printing and dyeing procedures and for other purposes where a predetermined oxidation-reduction potential is to be maintained.

. In certain types of printing known to those skilled in the arts as discharge printing, it is the custom to dye the cloth or fabric with certain types of dyestuffs which may be reduced to a colorless, soluble form and to imprint or place paste or viscous liquid containing a soluble reducing agent in a suitable design or pattern upon the dyed fabric and subsequently to dry, age and wash, whereby a white figure or design may be produced on the colored cloth. Or if it is desired, a colored figure or design may be produced instead of the white figure or design by addition of suitable colors, not affected by the reducing go agent, to the printing paste or liquid. For instance, a dark navy blue shade may be dyed on a fabric and then discharged to a clear white design or merely to a light blue by using less reducing agent. Qr in the event that itmay be 25 desirable to imprint" a black figure on a navy blue ground, the black color or pigment may be mixed with the printing composition containing the reducing agent. i

"It is also, custoinary in many cases to print 30 with a composition containing a normally insoluble dyestufl" which has been reduced to a soluble or leuco condition by inclusion in the printing paste of a reducing agent. After printing the dye and reducing agent are oxidized with result- 35 ant deposition of the insoluble dyestufi.

Hydrosulphites and sulphoxylates are widely used as such reducing agents in textile printing procedures, particularly to cause development of color or discharge of color in connection with 40 indigoid, anthraquinone, carbazol, sulphur and vat coloring matters in general. These hydrosulphites or sulphoxylates also are used in other processes and industries because of their reducing characteristics.

45 However, hydrosulphites and sulphoxylates and their derivatives have many disadvantageous characteristics. They are not most stable compounds and tend to decompose or change in strength standing in air and/or at elevated tem- 50 peratures, Moreover, they must be taken up in solution or employed in vcombinations withquantities of hygroscopic materials or agents which will maintain a moist condition when utilized in various textile printing-or discharge 55 procedures. Hygroscopic agents, such as glycerol, glycol and sugars increase the cost of processing the textile material. I g

It is, therefore, among the objects of the present invention-to provide improved reducing compositions'of the character above described'which 5 may be more conveniently used in connection withdyeing and printing of textiles or for many other purposes where the inclusion of a reducing agent has been found desirable or necessary.

Still further objects and advantages will appear 10 from the more detailed description set forth. below, it being understood, however, that this more detailed description is given by way of illustration since various changes therein may be made by those skilled in the art without depart- 15 ing from the scope and spirit of the invention.

It has been found that most satisfactory reducing compositions, particularly for use in processes where dyes are to be reduced in textile printing, dyeing and stripping, may'be produced by'heating together various carbo-hydrates and particularly water soluble carbo-hydrates or sugars with reducing sulphur. compounds and particularly with compounds of sulphurous acid.

It has been found that when various sugars, preferably sucrose or crudemixtures containing the same, and less preferablydextrine, glucose, fructose, black strap molasses, and so forth, are heated with sulphites and particularly with alkali metal or alkali earth metal sulphites under pressure and under acid conditions a most effective material is produced. i I

This reaction is preferably carried out in an autoclave or closed pressure vessel at pressures varying from to 15 atmospheres, preferably substantially above atmospheric, and at temperatures ranging from 50-to 150 C preferably about 110 C. i

Preferably, suflicient acid or acid materials such for example as sulphuric acid, phosphoric 40 acid, boric acid, sulfuryl chloride, phosphorous oxychloride, and so forth, are added to give a pHvarying from 1 to 4, and desirably around 2 or 3.

There apparently results a complex mixture containing various types of carbo-hydrate derivatives formed by the direct sulfonation of the hydroxy groups of the carbo-hydrate by the reducing sulfur compounds. The resulting prod-, uct consists of a very small quantity of unreacted carbo-hydrate, and larger quantities of the following compounds as such or their sulfur derivatives-polyhydroxy alcohols, .ketoand aldo compounds, polymerization products, aldols, acetals, etc., all of which appear to act most efiectively'tojgether as a reducing agent, particu la'rly 'when'the complex mixture has been neutralized.

The reaction mixture produced may be di- I phites and/or sulphoxylates to form textile printing, dyeing-and stripping compositionsr: r.

The solution which is prepared is most effective when it contains a substantial amount of water and it is found most. satisfactory to have the solid content range from about 40 to .60% concentration with an optimum oi about.50% con centration, which will not take up water from the air nor evaporate andwhich solution may be stored for long periods of time and utilized when convenient without special storage apparatus.

The composition may be used in printing pastes and in dye baths where dyes are to be reduced to soluble or leuco'form and it may be very conveniently combined with vat colors selected from the group consisting of indigoid colors, sulphur, anthraquinone colors and carbazol colors and with thickening agents such as British gum, gum

shiraz, gum tragacanth, dextrin, gum arabic,

starch, pectin, methyl cellulose without any un- 'desirable efl'ect upon the properties of such agents. a 1

- Although the composition when mixed with 'hydrosulphite or sulphoxylate has a relatively higher reducing action and much higher in many respects than hydro-sulphite or sulphoxylate itself, nevertheless, it is not oxidized by air and does not substantially lose its reducing power as do the latter compounds, although it be exposed to air over long periods of'time. This is particularly advantageous because in the printing operations it is at times necessary for the goods I to lay over between the printing and ageing operations. Where sulphoxylates and hydrosulphites are used alone as the reducing medium this laying over causes a variation in the shade because they may oxidize prematurely.

The reducing composition is specially advantageous since it has a much greater potential reducing power than hydrosulphites and sulphoxylates alone and at the same time will reduce at a slower rate.

The reducing composition may also be utilized at a wide variety of pI-Is and alkaline materials such, as sodium or potassium carbonate, potassium and sodium hydroxides, or mixtures of each and potash and soda ash may be included in the printing composition without any untoward eil'ect.

It is also readily possible to include moistening agents, such as glycerin, glycols, sugars and so forth, in the printing-composition without affecting the reducing agent.

Among the suitable base compositions which may be utilized for carrying the unreduced or pre-reduced color and/or the reducing composition is one containing about four pounds of British gum, two pounds of cornstarch, one eighth gallon of glycerol and two and one quarter pounds of potassium carbonate which is made up to three gallons with water.

The amount of water may be readily controlled to determine the final viscosity or pasty character of the mixture.

For example, to such a composition there may be added from 5 to 20% of a 50% solution of reducing composition and a suitable amount of vat one half color to obtain the d fiired shadeontintor depth or color.

The printing paste may be kept for along time with assurance that the reducing composition will not cause any undesirable disintegration or deterioration therein.

As an example of one method of producing a reducing mixture to which the invention is -by no 'mans restricted, 678 pounds of water may be introduced into a glass lined 500 gallon tank and 588 parts of sucrose may be dissolved therein.

Thenthe mixture may be heated for about an hour with stirring to dissolve the sugar.

Then, 234 pounds of sodium acid sulphite is added and the pressure is increased from 5 to 10 pounds per square inch, and this pressure is maintained for about one half hour.

The temperature is then permitted to drop to atmospheric with or without water cooling and the pressure is permitted to drop to about four pounds over the course of several hours.

The mixture is finally neutralized with caustic sodium or potash or triethanolamine.

The reducing mixture may then be immediately utilized with other materials in textile procedures.

As another example, a reaction mixture of 86 /2 pounds of water, 76 pounds of sucrose and 30 pounds of sodium acid sulphite may be provided and placed in a closed vessel.

The temperature is then elevated to 240 F.

vwith a pressure of ten pounds per square inch which pressure and temperature are maintained for one to two hours.

Then, the mixture is cooled until the pressure drops to five pounds and when it is cold about 67 pounds of acetone is added.

The pressure then may be brought up to pounds per square inch for about four hours with heating and the, mixture maybe permitted to cool for thirty six hours until it gets down to room temperature.

The product is neutralized, then withdrawn from the vessel and may be utilized as a, reducing agent.

The reducing composition may also be utilized in connection with bleaching compositions, washing compounds, foodstuffs, coating compositions. leather treating compositions, paper impregnating compositions and in many other connections where it is desirable to have a reducing agent present during a course of treatment.

Although the reducing agent may be "utilized by itself in textile processing it is preferably used to replace part of the hydro-sulphite or sulphoxylate and it may be used in combination with hydrosulphites, sulphoxylates, their formaldehyde derivatives or zinc, calcium or magnesium salts of such derivatives in substantially equal parts by weight' By the expressions vat dye or vat coloring matters as used in the present specification, are included indigoid, anthraquinone carbazol, sulphur, and other d-yes which are reduced or rendered soluble with a reducing composition before or after application to the fabric or textile material.

It is to be understood that many changes in the proportions, ingredients and treating conditions may be made without departing from the scope of the invention and it is intended to include all such alternative modifications and variations as come within the scope of the appended claims.

mospheres.

2. A textile coloring composition comprising a vat dye and a reducing composition formed by the reaction of a water soluble carbohydrate and a reducing sulphurous acid salt at a temperature varying between about 50 and 150 C., and at a pressurevarying about between V; and 15 atmospheres. V

3. A textile coloring composition comprising a vat dye and a reducing composition formed by the reaction of a water soluble carbo-hydrate and an alkali metal sulphite at a temperature varying between about 50 and-L 150 C.,-and a pressure varying about between and 15 atmospheres.

4. A method of making a-textile treating composition for use in dyeing and in processes wherein dyes are reduced to soluble, leuco, or colorless compounds which comprises reacting together a water soluble carbo-hydrate and a reducing sulphur acid salt under heat and pressure at a temperature varying between about 50 and 150 0., and a pressure varying about between and 15 atmospheres. 1 ,5. A method of ma 'ng a textile treating composition for use in dyeing and in processes wherein dyes are reduced to soluble, leuco, or colorless compounds which comprises reacting together a water soluble carbo-hydrate and a salt of sul-' phurous acid under heat and pressure at a tem- I 6.,

perature varying between about 50 and150 and a pressure varying about between V, and 15 atmospheres. q

6. A textile treating composition for use in dyeing and in processes wherein dyes are reduced to soluble, leuco, or colorless compounds comprising the heat and pressure reaction products of a water/soluble carbo-hydrate and a reducing sulphur acid compound at a temperature varying betweenabout and I varying about between V; and 15 atmospheres.

'7. Asa textile printing composition comprising a thickening agent and a reducing composition formed by the reaction of sugar and a bisulphite under heat and pressure, said heat Y varying from about 50 C4 and a pressure varying from about 50 to 150 0., and said pressure varying from about A to 15 atmospheres.

8. A textile printing composition comprising British gum and a reducing composition formed by the reaction of sugar and a bisulphite under heat and pressure, said heat varying from about 50 to 150 0., and said pressure varying from about A to 15 atmospheres.

9. A printing composition comprising a vat color, British gum, a reducing composition formed by the reaction of sugar and a bisulphite under heat and pressure, cornstarch, glycerol, and potassium carbonate, said heat varying from about 50 to 150 0., and said pressure varying from about /z to 15 atmospheres.

10. A process of printing textiles which comprises treating such textiles with a printing composition containing a reducing composition formed by the reaction of sugar and a bisulphite under heat and pressure, said heat varying from about 50 to 150 C., and said pressure varying from about A to 15 atmospheres.

11, A process of printing textiles which comprises treating such textiles with a printing composition containing a reducing *composition iormed by the reaction of sugar and a bisulphite under heat and pressure, said heat varying from about 50 to 150 C., and said pressure varying from about /2 to 15 atmospheres.

13. A process or printing textiles which comprises treating such textiles with a printing composition containing a reducing composition formed by the reaction of sugar and a bisulphite under heat and pressure, a 'vat color, a thicken ing agent and potassium carbonate, said heat to 150 0., and said pressure varying from about /2 to 15 atmospheres.

13. A vat dyeing composition comprising a vat dye and a reducing composition formed by the reactibn of sugar and a bisulphite under heat and pressure, said heat varying from about 50 to 150 0., and saidpressure varying from about 5 2 to 15 atmospheres. v a

, 14. A process of producing vat dyes which comprisess reacting said vat dyes in .aqueous media with 'a reducing composition including the