US2383900A - Treatment of cellulosic textile materials - Google Patents

Description

Patented Aug. 28, 1945 TREATMENT OF CELLULOSIC TEXTILE MATERIALS George P. Vincent, Briarclitf, N. Y., Archie Louis Dubeau; Rumi'ord, R. I., and John Francis Synan, Fall River, Mass., assignors to The Mathieson Alkali Works, Inc., New York, N. Y., a corporation of Virginia No Drawing. Application January 23, 1942, Serial No. 427,950

' 8 Claims.

This invention relates to the treatment of cellulosic textile materials, such as cotton piece goods, synthetic cellulosic fibers, mixtures of cotton and rayon in woven form and yarns of both natural and synthetic cellulosic material.

Hypochloritcs have heretofore been used extensively in the bleaching of cotton fibers and synthetic cellulose fibers. The use of hypochlorites, such as sodium or calcium hypochlorites in bleaching such fibrous material is accompanied by the tendency to form oxycellulose. This degradation product is objectionable in yarns or cloth 'as it causes tendering of the fiber, the development of yellow color on storage and uneven dyeing. Fairly good result may be obtained. however, and the amount of oxycellulose formed may be kept to a minimum by careful chemical control of the process. It is, however, generally impossible to complete y prevent the formation of oxycellulose.

It has recently been found that vastly improved results can be obtained and all danger of formation of oxycellulose can be avoided by bleaching the goods with sodium chlorite in an acid solution. The hypochlorites used in bleaching are in an alkaline solution. Sodium chlorite destroys the coloring matter in the material being bleached but is not powerful enough toattack the fibers themselves. Careful control is therefore not necessary and better and more permanent whites are obtained without loss of tensile strength even when a high brightness is desired. Where the-facilities are available for the use of acid solutions, bleached good of a high quality can thus be produced at a low cost by the use of sodium chlorite but the process requires radical changes in bleaching methods in plants that have heretofore employed sodiiun or calcium hypochlorite bleaching processes using alkaline solutions.

In'the copending application Serial No. 405,989 filed August 8, 1941,'one of us has disclosed a process of bleaching cellulose textile materials by using a mixture of sodium chlorite and a hypochlorite in an alkaline solution. In the process disclosed in that application the mate rials to be bleached are scoured prior to the bleaching operation. The present application is directed to a modification of the process disclosed in that copending application which is applicable to treatment, for instance in a package machine, of material that has had no previous scouring.

In theconventional package machine process the operation consists of both a bleaching and scouring action carried on simultaneously at a uniformly high -temperature. In accordance with the present'invention the material is packed in the package machine and a bleach liquor, comprising an alkaline aqueous solution of a chlorite anda hypochlorite and to vfiiich a suitable detergent has been added, is circulated through it under pressure at a moderate temperatur such as indicated in the above-noted application. After the bleaching operation has been completed the temperature is raised to approximately 00 F. at which temperature a scouring action takes place due to the synthetic detergent. At the end of the scouring operation the chloritehypochlorite detergent solution is run of! and the material washed with hot water.

In conducting the bleaching and scouring of cellulosic textile materials in a package machine using a mixture of sodium chlorite and a hypochlorite in an alkaline solution, in conjunction with a suitable detergent in accordance with the present invention, we have found that superior results may be obtained over those which have heretofore been" obtained by employing a hypo chlorite alone as the bleaching agent. The prac-- tice results in good color, decrease of oxycellulose and may be carried out with a smaller amount of available chlorine than when a hypochlorite is employed as the only bleaching agent.

As stated, the process is carried out in an alkaline solution, and while the pH of the solution may vary within wide limits we find that the best results are obtained if the pH is maintained between 8.0 and 11.0. The grams per liter of available chlorine present in the solution may also vary within wide limits, but we have found that the best results are obtained when the grams per liter of available chlorine are between 1.0 and 10.0. Any of the well known detergents may be employed for the scouring operation. We preferably employ one of a number of well known synthetic detergents including a large number of sulfated or sulfonated organic compounds. Among the detergents which we may use are:

Sodium sulfoethyl methyl oleyl amide (sold under the trade name of Igepon T) Sodium borosult'ate of octadecenyl alcohol '(sold under the trade name of Mapromine) Sodium lauryl sulfate (sold under the trade name of Gardinol) Sodium sulfate of octadecenyl alcohol (sold under the trade name of Modinol) Sodium sulfonate of alkylated phenol (sold under the trade name of Nacconal) Sodium sulfonate of alkylated benzene (sold under the trade. name of Santomerse) Sodium diamyl to sodium dioctyl, sulfosuccinate (sold under the trade name of Aerosol) IAS stated, the process is conducted by placing cellulosic textile materials which have had no previous scourin in a package machine and then circulating the bleach liquor under pressure. We preferably prepare a solution containing the selected detergent, sodium chlorite and a relatively weak alkali, such as tetra sodium pyrophosphate. This liquid is circulated through the machine for a period of about 5 minutes at a temperature from 85 to 95 F. to wet the cellulosic material being treated. The desired amount of a hypochlorite, such assodium hypochlorite, is then added in solution and circulated for a period of approximately 45 minutes. During this time the temperature is raised to a temperature of 110 to 120 F. Steam is then turned on and the solution circulated for approximately 45 minutes. During this last step the temperature is raised to approximately 200 F. in the first or minutes and held at that temperature until the end of the run. Y

As specific examples of the process the following are cited:

Example I A solution containing approximately 2 parts of Igepon T, 6 parts of sodium chlorite and 24 parts of tetra sodium pyrophosphate was circulated through a machine containing yam to be treated solution circulated for about 45 minutes. During this period of time the temperature was increased to 122 F. The available chlorine present during this portion of the process was suflicient to carry out the necessary bleaching operation At that time the temperature was raised by turning on steam and in 15 to 20 minutes was brought up to 200 F. The temperature of 200 F. was maintained for a period of approximately minutes during which time there was no available chlorine present and the securin operation was performed by the detergent. The results of this test were the production of good color and removal of motes. Theresulting absorbency was good, and the strength tested by the cupro-ammonium viscosity test was excellent,

Example II In this instance a very coarse and cheap yarn was scoured and bleached by placing the yarn in the package machine and then treating it with a solution containing 1% parts of Igepon T, 4 parts-of sodiumvchlorite and 19 parts of tetra sodium pyrophosphate for a period of approximately 5 minutes at a temperature of approximately 95 F. to wet out the yarn. 9 parts of available chlorine as sodium hypochlorite were then added and the composite solution circulated for 45 minutes. At this point. thesteam was turned on and the temperature increased to 200 F. after about 20 to 25 minutes and held there to the end of the run. The circulation was continued for about 45 minutes after the steam was turned on. The treated material was then washed with water at 120 F. and again at 150 F. The solution was tested for available chlorine which was found to be present in desired quantities until the temperature reached 120 F, after which the available chlorine decreased until there was none available when a temperature of 180 F. was reached. The results of this procedure were ,the production of good color, fairly good mote removal, excellent strength and excellent dyein quality. The strength was measured by the cupro-ammonium viscosity method.

Example III In this instance the material treated was yarn and substantially the same procedure was followed. The original solution consisted of 2 parts of Igepon T, 4 /2 parts of sodium chlorite and 24 parts of tetra sodium pyrophosphate. After the initial wetting, 92 parts of a 10% solution of hypochlorite were added and after circulating the composite solution for a period of substantially 45 minutes the temperature was raised to 200 F. and the process continued for an additional 45 minutes. The results obtained were substantially the same as those set forth in the preceding tests.

\ Example IV In this instance the same procedure was followed, the initial solution comprising Mapromine ,1 part, sodium chlorite 4.15 parts, and tetra sodium pyrophosphate 6 parts. After the material was wet with this solution, a solution of sodium hypochlorite containing 8 parts of available chlorine was added and the process continued as heretofore described.

In the examples given, the ratio of hypochlorite to sodium chlorite is substantially l /zzl on the basis of available chlorine but the ratio may be varied within certain limits. As stated, the process results in the production of material equal to or better than that obtained by treatment with a hypochlorite alone with the use of less avail able chlorine in the bleaching solution.

While the examples given disclose. the use of sodium hypochlorite, other hypochlorites used in bleaching, such as calcium hypochlorite, may be employed. Likewise chlorites of the other alkali metals may be used in place of sodium chlorite. The temperatures employed during the bleaching operation of the process and the higher temperature employed during the scouring portion of the process are not, critical. It is preferable to have the solution slightly heated during the initial portion of the process as setforth in the examples, but the temperature may be 'lower than 85 F. or higher than 95 F. It is necessary that an elevated temperature be employed during the scouring portion of the process and any temperature slightly below the boiling point of water may be used.

We claim:

1. The process of bleaching and scouring cellulosic textile material which comprises treating the material with an alkaline solution of a hypochlorite, an alkali metal chlorite and a detergent at a moderate temperature not substantially exceeding about 120 F., for a period of time sufilcient to bleach the textile and substantially to exhaust the hypochlorite present in the solution, then raising the temperature of the solution to substantially 200 F. and continuing the treatment for a period of time sufiicient for scouring the textile.

2. The process of bleaching and scouring cellulosic textile material which comprises treating the material with an alkaline solution of a hypochlorite, an alkali metal chlorite and a detergent at a temperature of about F. to F. for a period of time sufficient to bleach the textile and substantially to exhaust hypochlorite present in the solution, then raising the temperature of the solution to substantially 200 F. and continuing the treatment for a period of time sufficient for scouring the textile.

3. The process of bleaching and scouring cellulosic textile material which comprises treating the material with an alkaline solution of a hypochlorite, sodium chlorite and a" detergent at a moderate temperature not substantially exceeding about 120 F;, for a period of time sufiicient to bleach the textile and substantially to exhaust the hypochlorite present in the solution, then raising the temperature to substantially 200 F. and continuing the treatment for a period of time suflicient for scouring the textile.

4. The process of bleaching and scouring cellulosic textile material which comprises treating the material with an alkaline solution of a hypochlorite and sodium chlorite in a ratio of substantially one and one-half to one based on the available chlorine, and a detergent at a moderate temperature not substantially exceeding about 120 F. for a period of time sufllcient to bleach the textile and substantially to exhaust the hypochlorite present in the solution, then raising the temperature-t the solution to substantially 200 F. and continuing the treatment for a period of time suflicient for scouring the textile.

5. The process of bleaching and scouring cellulosic textile material which comprises treating the material with a solution of a hypochlorite, an alkali metal chlorite and a'detergent having a pH of from 8 to 11 at a moderate temperature not substantially exceeding about 120 F. for a period of time suificient to bleach the textile and substantially to exhaust the hypochlorite present in the solution, then raising the temperature of the solution to substantially 200 F. and continuing the treatment for a period of time sufiicient for scouring the textile.

6. The process of bleaching and scouring cellulosic textile material which comprises treating the material with an alkaline solution of a hypofor scouring the textile.

chlorite, sodium chlorite and sodium sulfoethyl methyl oleyl amide at a moderate temperature not substantially exceeding about F., for a. period of time suilicient to bleach the textile and substantially to exhaust the hypochlorite, present in the solution, then raising the temperature of the solution to substantially 200 F. and continuing the treatment for a period of time suificient for scouring the textile.

7. The process of bleaching and securing cellulosic textile material which comprises treating the material with an alkaline solution of a hypochlorite, sodium chlorite and sodium borosulfate of octadecenyl alcohol at a moderate temperature not substantially exceeding (about 120 F. for a period of time suilicient to bleach the textile and' substantially to exhaust the hypochlorite present in the solution, then raising the temperature of the solution to substantially 200 F. and continuing the treatment for a period of time sufficient 8. The process of bleaching and scouring ce1-. lulosic textile material which comprises treating the material with an alkaline solution of a hypochlorite, sodium chlorite and a detergent at a moderate temperature not substantially exceeding 120 F., for a period of time sufficient to bleach the textile and substantially to exhaust the hypochlorite present in the solution, the solution having a pH 01' from 8 to 11 and containing from 1 to 10 grams per liter of available chloriney the ratio of hypochlorite to chlorite in the solution being substantially one and one-half to one on the basis of available chlorine, then raising the temperature of the solution to substantially 200 F., and continuing the treatment for a period 01' time suificient for scouring the textile.

GEORGE P. VINCENT. ARCHIE LOUIS DUBEAU. JOHN FRANCIS SYNAN.