US2195585A - Colored textile materials and method of producing same - Google Patents

Description

Patented Apr. 2, 1940 I UNITED STATES COLORED TEXTILE MATERIALS AND METHOD OF PRODUCING SAME George W. Seymour and Victor Sluyty Salvin,

Cumberland, Md., assi poration of America, ware No Drawing. Applicati gnors to Celanese Cora corporation of Delaon February 11, 1938,

Serial No. 190,041

10 Claims.

This invention relates to the production of dark colored textile materials that are made of or contain organic derivatives of cellulose and, more particularly, to the method of producing a dark color in or on such textile materials.

An object of this invention is the economic and expeditious production of black-dyed fabrics and other textile materials made of or containing organic derivatives of cellulose, the coloration being effected by applying a diazotizable dyestuff base to the material, diazotizing and coupling with a naphthoic or similar acid. Another object of this invention is the production of black fabrics or other textile materials, made of or containing organic derivatives of cellulose, that do not crock or bleed and that are more fast to acid and light fading than fabrics dyed by methods employed prior to this invention. Other objects ofour invention will appear from the following detailed description.

By employing this invention, there is effected an improvement both in reducing crocking and/ or bleeding and a more uniform standard shade is obtained. In accordance with this invention, there are produced black fabrics containing. organic derivative of cellulose yarns that do not bleed pink when rubbed with a similar but undyed fabric wet with perspiration nor :crock black when rubbed with a dry white fabric. Forthe purpose of describing this invention the term crocking will be used as including bleeding or other forms of dyeing defects that allow the black fabric to color white fabric. attached thereto when the two fabrics are washed, dry cleaned, subjected to perspiration, acid fumes or rubbing.

By employing this invention, there is also produced a black fabric containing organic derivative of cellulose yarns that is more fast to acid fading and light fading than similar black fabrics produced prior to this invention. The sta-' bility of the dyed fabric is extremely good making it exceptionally well suited as a lining fabric for coats or other wearing apparel.

It is known thatthere are three major forms of crocking of; fabric containing organic derivatives of cellulose that are dyed black with diazotized dyestufis. First, and least desirable, is a pink-to-red crocking which appears to vary in intensity with different batches of dyed fabric. The tendency of this type of pink-to-red crocking is to bleed off from a coat lining fabric when wet with perspiration. Crocking in another form is evidenced as a black coloration which also appears to vary in intensity with different batches,

with different qualities of fabric and with the same quality of fabric which has been processed in two batches by apparently identical means. The third form of crocking appears as an oily black substance which is ready removable by thorough scouring, which scouring, however, is sometimes required to be more severe than fabrics containing organic derivatives of cellulosecan withstand. We have found that by employing this invention, these types of crocking can be eliminated or substantially eliminated without the addition of costly reagents or additional processing steps. At the same time a more stable fabric is produced that has a faster color.

In accordance with this invention, we apply a diazotizable black dye base to a fabric containing an organic derivative of cellulose and diazotize the base in the presence of an excess of mineral acid (preferably HzSO4, HCl or mixtures of these) for each amino group to be diazotized. The excess of mineral acid is preferably about mol excess of mineral acid per amino group to be diazotized. Since the mineral acid must be removed prior to coupling, preferably by washing, we have found that not more than a few ends in a jig at 25 C. or its equivalent in a wench should be used instead of the customary large number of ends. In order to remove all of the mineral acidfrom the fabric the bath should contain sodium acetate, sodium bicarbonate or other soluble neutralizing salts. Where sodium acetate is employed in the bath, better shades are obtained and pink-to-red crocking is substantially eliminated. The washing should be carried out by a process which avoids exposure of the diazotized fabric to light, air, heat, etc. and which removes the excess acid rapidly. After washing to remove excess acid the diazotized fabric is coupled with a suitable coupling compound, preferably ,B-oxy-naphthoic acid. In order to decrease the decomposition products caused by side reaction in the coupling process, the diazotized fabric must be coupled soon after diazotization has been completed. The temperature and pH value of the coupling bath must be closely controlled while the accessibility of the coupling compound to the fabric and the thorough adsorption of the coupling compound into the fabric must be observed. The coupling operation should be performed by runmng the fabric two or three ends at 20 C. in'a jig or its equivalent on a wench to promote efficient adsorption and then 1 to 3 ends at 38 C. to 42 C. to promote coupling with a final end at about C. to C. to accelerate coupling and to decompose any remaining azo group. The coupling compound is dispersed in the treating bath with the aid of dispersing agents with sufllcient buffer salts (preferably sodium acetate or sodium bicarbonate) to maintain the pH value of the bathat between 5 to 7. The coupling compound couples best at about a pH value of 7 or higher, but then it is present as a metallic salt which is not readiLv adsorbed by the fabric. Therefore, the pH value should be "I or slightly below, .preferably between 5 and 7. g

This invention is applicable to yarns, fibers, ribbons, straws, etc., but more especially to fabrics made of or containing organic derivatives of cellulose such as the organic esters of cellulose, mixed esters of cellulose and the cellulose ethers. Examples of the organic esters of cellulose are cellulose acetate, cellulose formate, cellulose propionate and cellulose butyrate, while examples of the cellulose ethers are ethyl cellulose, methyl cellulose and benzyl cellulose.

The fabric to be treated may be made wholly of organic derivative of cellulose material or it 1 terial may be aniline-4-azo-4-a-naphthylamine or analogues of the same which when coupled with a suitable coupling agent produces a dark color. Suitable analogues and the color they produce when coupled with p-oxy-naphthoic acid are phenol-4-azo-4-a-naphthylamine (bl u is h .black) benzene-i-azo-i a-naphthylamine (reddish black), para-methoxy-benzene-azo-a-naph- 40'.

.thylamine (bluish black of very good depth), ortho methoxzybenzene azo a naphthylamine (purplish' black) and naphthalene-azo-a-naphthylamine (slightlyreddish black).

The coupling compound is preferably p-oxynaphthoic acid or its analogues which produces a black or substantially black color on the fabric. However, the invention is also applicable where coupling compounds that produce a blue color or a red color or combinations of these colors are employed. Examples of such coupling compounds are a-naphthoh, p-naphthol, phenol,- salicylic acid and their derivatives or substitution products.

It has been customary in the past when applying the dye base and forming the diazonium compound to employ a mixture of formic-hydroformed in the presence of an organic acid decomposes markedly at 30 to 40 0. whereas thediazonium salts produced in the presence of hydrochloric, sulphuric or other mineral acid is relatively stable up to 50 to 60 0. Thus, where inorganic acids alone are employed, there is not only produced a more uniform shade on the fabric but there is also permitted a greater range of temperature in future processing steps. The

use of mineral acids only promotes the possi-- bility of more complete diazotization. When sufficient mineral acid is used diazotization is between and complete, provided, how- 1 ever, that there is an excess of the mineral acid employed. For instance, when diasotizing aniline-4-azo-4-a-naphthylamine l1 mols of the dye base are employed, and 42 mols of sodium nitrite and 44 mols of hydrochloric acid or its equivalent are the absolute minimum necessary for complete diazotization. For improved results to be derived in accordance with this invention the presence of an excess of mineral acid is required. This excess should be about mol of acid per amino group. Where excess acid less than this quantity is-employed, it has been found that there is a tendency towards sluggish reaction and incomplete diazotization. The excess acid, however, may be from about mol to 1 mol excess of acid per amino group to be diazotized. Due to the excess acid present during the diaaotiliation step it is preferable to maintain the temperature-at' between 5 to 10 C. with ice or artiiicial cooling means to prevent injury to the dyestufl', fabric or machine and to the operator due to the evolution of acid fumes. The temperature may be allowed to raise to about-50 C. When sulphuric acid is employed since the diazonium, sulphate is stable up to about60 C.

With other mineral acids other maximum temperatures would apply., The 42 mols of nitrite is; of course, not the theoretical quantity necessaryto react with llmols of dye base, as 22 mols would be. suiiicient. This excess quantity is based on the empirical evidence that this quantity gives the best results for complete diazotization.

The large excess is in part necessitated in order to maintain the equilibrium for nitrous acid formation under the conditions present.

After diazotization it is necessary to subject the fabric toa washing process in order to remove the excess inorganic acid. This is neces-.

sary for two major reasons, one to prevent the precipitation of the coupling compound as a nonreactive. material and, second, to enable the coupling to proceed thoroughly and uniformly. The diazonium salts of the inorganic acid must be hydrolyzed to the diazohydrate in order for it to couple at a reasonable rate. The diasotized fabric n ust be washed thoroughly. and quickly without exposure to air, light or heat. Exposure 7 of the fabric produces an irreversible decomposition of the diazonium compound which, after it occurs, greatly increases the tendency oi -the dyed fabric to crock. The amount of dye'base applied to the fabric may be any suitable amount, say from 0.1 to 6% by weight of the fabric.

After the dye base has been applied to the fabric and the fabric washed free of excess mineral acid, the fabric issubjected to an operation including the application thereto of a coupling compound undersuch conditions that the coupling compound reacts with the diam-compound.

formed from the dye base. The- 'coupling reaction must always be looked upon as a race between azo compound formation and decomposition of the diazo compound. Some diazonium compounds are so sensitive. to this factor that rigid control of the pH value of the treating bath is necessary 'to obtain consistent results sorbed on the fibers it must be present as an 7 In this respect the acid. Obviously, therefore, the pH value of the aqueousdispersion of the coupling compound must be below '7, preferably between 5 and '7, as below this'point an adsorption readily takes place but coupling is sluggish and acid reaction compounds are formed.

In the coupling operation the temperature of the treating bath must also be controlled in order to produce an improved dyeing and a uniform shade from batch to batch. In order to decrease the decomposition products from side reactions to the coupling process the diazotized fabric must be subjected to the coupling reagent immediately after diazotization has been completed. The temperature of the bath at the time the fabric is subjected thereto is preferably around 20 C. for at this temperature the adsorption of the coupling compound by the fabric is greatly facilitated. The temperature should then be raised to about 40 C. to promote coupling and retard decomposition, blackening of the fabric, due to coupling, does not occur until this temperature has been reached. The temperature should then be rapidiy raised to above 60 C.. preferably between 60 and 75 0., to accelerate coupling and to decompose the remaining azo groups. For instance, when dyeing the fabric on a jig the fabric is run two ends at 20 C. to permit thorough incorporation of the p-oxynaphthoic acid in the fiber, two ends at 40 C. for at this temperature coupling starts, then two ends at 70 C. in order to complete the coupling of the sluggish reaction. The. high temperature should be avoided initially since decomposition of the diazonium compound of the dye base is accelerated at those temperatures.

The bath from which the coupling compound is appliedto the fabric is preferably formed by dispersing the coupling compound in a dispersing agent approaching neutrality and well buffered with such salts as sodiumacetate or sodium bicarbonate for changes in pH value. It is known that if the particle size of the coupling compound is controlled by the use of a dispersing agent a great reduction in the amount of crocking of the dyed fabric is obtained. The use of the dispersing agent is imperative also in that it controls the particle size and disperses the coupling materials which form the coupling bath, thus making a more uniform and thorough penetration of the coupling compound into the fabric. This dispersion also prevents the superficial formation of the dye on the outside of the fabric and also to the deposition of nondispersible compo-ands adhering to the fabric from the coupling process. Obviously the dispersing agent should have no reaction with the coupling compound. Suitable dispersing mediums which may be employed with the coupling compounds listed above are a mixture of Turkey red oil and xylol, the sodium salt of sulphated lauryl alcohol or other higher fatty alcohol, sulphonated vegetable oils, dextrin, sulphated naphthene and similar dispersing mediums or mixtures of the same.

In order to further illustrate our invention, but without being limited thereto, the following example is given:

EXAMPLE This example is for jig dyeing. A typical charge is 150,000 grams of fabric. By one end" is meant one pass through the dye solution without regardto difierential in speed and time due to the change in diameter of the fabric on the beam. At normal speeds one end would take from 20 to 30 minutes. A typical Black dyeing on the jig would use the following quantities:

, Rinse 2 ends cold; 2 ends at 90 C.-to set the fabric to the 118.

Basing Fabric grams 150,000 Water liters 500 Black dyebase grams Sulphonated naphthalene ricinoleic acid ..do Gardinol do 2,600 Soda ash do 800 Temperature, 90 C.; time, 50 ends= 1000 min.

scouring Gardinol grams 3,000 Soda ash do Water liters.. 500

Temperature, 90 C.; time, 10 ends=200 min.

Diazotization Water -1 liters Sodium nitrite grams H2804 ccs 2,000

Temperature, iii-22 C.; time, 4 ends= min.

Wash

Cold water liters 500 (Sodium acetate optional) grams 500' (Residual HNO2 or HCl negligible.)

Temperature, 18-20 C.; time, 2-3 ends= 40-60 min.

This bath should have a pH of 6-6.5 and should not change materially during processing.

Wash

Washing may be carried out with either hot or cold water in order to free the fabric from the ingredients of the coupling bath.

With regard to the amount of water retained in the fabric before, between and after each processing step, the fabric is at all times thoroughly wetted out after the initial step of setting to the jig. The amount'of water retained by the fabric will probably be between two and five times the weight of the fabric, depending upon the type of fabric, weave, twist, and whether or not it was mixed with cotton, viscose, silk, etc.

. The fabric after drying is found to be colored a good black and to be exceptionally fast to light and acid-alkali or perspiration fading. The chemical stabilityjof the organic derivative of cellulose in the fabric is found to be substantially as good as the stability of the undyed material. It is to be understood that the foregoing detailed description is merely given by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

. 1. Process .for the production of 'dark colored textile materials containing organic derivatives.

of cellulose by a process employing diazotizable 15 dyestufl's, which comprises applying a diazotizable dyestufi' base to said textile materials, diazotizing said dyestufi base, washing the treated textile materials with water until the diazonium salt formed is hydrolyzed to the diazohydrate, and couplind with a coupling component producing a dark color on said textile materials.

2. Process for the production of dark colored textile materials containing cellulose-acetate by a process employing diazotizable dyestufls, which comprises applying a diazotizable dyestuff baseto said textile materials, diazotizing said dyestufi base, washing the treated textile materials with water until the diazonium salt formed is hydrolyzedto the diazohydrate, and coupling with a coupling component producing a dark color on said textile materials.

3. Process for the production of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestuffs, which comprises applying a diazotizabledyestuflf base to said textile materials, diazotizing said dyestuif base in the presence of an excess of mineral acid, washing the treated textile materials with water until the diazonium salt formed is hydrountil the diazonium salt formed is hydrolyzed to the diazohydrate, and coupling with a coupling component producing a dark color on said textile materials.

5. Process for the production of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestuifs, which comprises applying a diazotizable dyestufi base to saidtextile materials, diazotizing said dyestuil base in the presence of an excess of mineral acid, washing the treated textile materials with water for 40 to 60 minutes to hydrolyze the diazonium salt formed to the diazohydrate, and coupling with a coupling component producing a dark color on said textile materials.

6. Process for the production of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestufis, which comprises applying a diazotizable dyestufi base to said textile materials, diazotizingsaid dyestufi base in the presence of an excess of mineral acid, washing the treated textile materialswith water for 40 to 60 minutes inthe presence of sodium acetate to .hydrolyze the diazonium salt formed to the diazohydrate, and coupling with a coupling compat ent-producing a dark color on said textile materials.

7. Process for the production of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestufis, which comprises applying ,a diazotizable dyestufl base to said textile materials, diazotizing said dyestufl base in the presence of an excess of mineral acid, washing the treated textile materials with water for 40 to 60 minutes in the presence of sodium acetate to hydrolyze the diazonium salt formed pH value is maintained at between 5 and 7.

8. Process for the production dark colored textile materials containing organic derivatives of cellulose by a process employing diazotizable dyestufis, which comprises applying a diazotizable dyestufi base "to said textile materials, diazotizing said dyestufl base inthe presence of an excess of mineral acid, washing the treated textile materials with water for 40 to 60 minutes in the presence of sodium acetate to hydrolyze the diazonium salt formed to the diazohydrate, and coupling with ,s-oxy-naphthoic acid in a coupling bath in which the pH value is maintained at be-. tween and 7.

9.- Process for the production of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestufls, which comprises applying a diazotizable dyestufi base to said textile materials, diazotizing said dyestufl! base in the presence of an excess of mineral acid,

washing the treated textile materials withwater' for 40 to 60 minutes in the presence oi. sodium acetate to hydrolyze the diazonium salt formed to the diazohydrate, and coupling with p-oxynaphthoic acid in a coupling bath in which the pH value is maintained at between 5 and 7.

10. Process for the production of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestufis, which comprises applying a diazotizable dyestufi base to said textile materials, diazotizing said dyestufl base in the presence of an excess of mineral acid, washing the treated textile materials with water for 40 to 60 minutes in the presence of sodium acetate to hydrolyze the diazonium salt formed to the diazohydrate, and coupling with p-oxynaphthoic acid dispersed with the aid of a dispersing agent in an aqueous bath in which the pH value is maintained between 5 and 7.

GEORGE W. SEYMOUR. VICTOR SLUY'I'Y SALVIN.

.tile materials in a coupling bath in which the CERTIFICATE OF coR EcTio'N.

P a-tent No. 2,195,585. April 2, 19M).

v GEORGE W'. SEYMOUR, AL} It' is hereby Certified that error appears in the printed specification of the above numbered patent requiring correction he follows: Page 5, secend column,1:Lne 15, in the table, ffor Gardinol- --db---2, 600" read --.Ga.rd1nol--- io---,OOO-- page 1;, first column; line 6; claim 1, for couplind read :oupl1ng--;

and that the s eid Letters Patent should. :be read with this-correction therein that the Same may cenferm to the record of the case in the Patent Office.

Signed andeealed thielhth day of May, A. D. 19, 0.

, Henry Vggm Arsdaie, (Seal) Acting Commissioner of Patents.