US3756777A - Pad cure process for the preparation of deae cotton - Google Patents

Abstract

THIS IS AN IMPROVED PROCESS FOR PREPARING DIETHYLAMINOETHYL COTTON. 2-CHLOROETHYLDIETHYLAMINE (DEAE) HYDROCHLORIDE IS FIRST REACTED WITH ALKALINE HYDROXIDE TO PRODUCE A WATER-INSOLUBLE LIQUID WHICH IS THEN THOROUGHLY MXED WITH A QUANTITY OF WATER AND IN A MATTER OF MINUTES IS CONVERTED TO A WATER-SOLUBLE DIETHYLAZIRIDINIUM CHLORIDE (DAC). THE PREPARATION OF DIETHYLAMINOETHYL COTTON CAN BE CARRIED OUT IN A ONE-STEP OPERATION WITH REAGENT CONCENTRATION OF UP TO A SATURATED SOLUTION, ABOUT 2 MOLAR, AND CAN BE ACCELERATED WITH BASE IN THE PAD BATH. THE PROCESS IS AMENDABLE TO CONTINUOUS OPERATION.

Description

United States Patent 3,756,777 PAD-CURE PROCESS FOR THE PREPARATION OF DEAR-COTTON Earl J. Roberts, Clinton P. Wade, and Stanley P. Rowland, New Orleans, La., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Filed July 30, 1971, Ser. No. 167,814

Int. Cl. D06m 13/38, 13/34 US. Cl. 8-188 6 Claims mxed with a quantity of water and in a matter of minutes is converted to a water-soluble diethylaziridinium chloride (DAC). The preparation of diethylaminoethyl cotton can be carried out in a one-step operation with reagent concentration of up to a saturated solution, about 2 molar, and can be accelerated with base in the pad bath.

The process is amendable to continuous operation.

A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to an improved process for the preparation of diethylaminoethyl cotton. More specifically, this invention relates to the preparation of waterinsoluble 2-chloroethyldiethylamine by reacting an alkali hydroxide with 2-chloroethyldiethylamine hydrochloride to produce a water-insoluble liquid. This liquid is converted to a water-soluble diethylaziridinium chloride upon 7 mixing thoroughly with water. Any concentration of the diethylaziridinium chloride, up to a saturated solution, about 2 M (about 27%), can be employed to react with cotton, and the reaction can be accelerated by adding a quantity of base up to or greater than the concentration of the diethylaziridinium chloride (DAC).

Hartman, Guthrie, Bullock, and many others have reported the formation of diethylaminoethyl cellulose mainly in wet-process reactions of cellulose with 2-chloroethyldiethylamine. It has also been reported that 2-chloroethyldiethylamine dissolves in water to form the diethylaziridinium chloride. The present invention does not purport these ideas as new. With respect to cotton fabrics, what this invention discloses is a method of preparing the diethylaminoethyl cotton in a new one-step, dry-cure process, among other things.

PRIOR ART Roberts and Rowland report in the,Canadian J. of Chem. 45, page 261 (1967) this related work. Cotton fabric was padded to a 100% wet pickup in a 20% aqueous solution of 2-chloroethyldiethylamine hydrochloride.

The wet impregnated fabric was placed on a pin frame and immersed for 3 minutes in an excess of 20% sodium hydroxde solution which was saturated with sodium sulfate. This impregnated fabric was placed inside a polyethylene bag and left there for 19 hours. It was then 3,756,777 Patented Sept. 4, 1973 rinsed with 1 N acetic solution and water. The nitrogen content of this cotton fabric after treatment was 0.39%.

Soignet et al. report in Textile Research J. 39, page 780 (1969) this related work. Cotton fabric was padded to a 100% wet-pickup n a 20% aqueous solution of 2- chloroethyldiethylamine hydrochloride and reacted with 8% sodium hydroxide at C. for about 10 minutes. The excess sodium hydroxide was removed by washing the fabric in dilute acetic acid, then with water. A single treatment by this process yelded a finished fabric with a nitrogen content of 0.4%. A higher nitrogen content was obtained by repeated treatments.

Berni et al. report in Textile Res. J. 40, page 99 (1970), the preparation of sodacellulose fabrics which are then inserted into cylinders which contain various concentrations of 2-chloroethyldiethylamne in tertiary butanol, at room temperature. For this series reaction times were also varied. The reacted fabrics were then removed, rinsed, and neutralized in dilute acetic acid and rinsed in water.

The main object of this inventon is to provide a drycure process for the preparation of diethylaminoethyl derivatives of cotton, generally referred to as DEAE- cotton.

A second object of this invention is to provide a drycure method of preparing diethylaminoethyl derivatives of other polysaccharide-containing materials.

A third object of this invention is to provide a drycure method of preparing variations of the objects, such as the preparation of DEAE derivatives of starch, wood pulp, and regenerated cellulose.

Diethylaminoethyl (DEAE) cellulose has found considerable utility as an ion-exchange material, especially in chromatographic separation of amino acids, polypeptides, and proteins. DEAE-cotton has been prepared by a variety of procedures but we find these disadvantageous in that they have all been wet processes requiring multistep bath operations.

We further find disadvantageous the processes of the prior art in that a sequence of steps is required in the preparation of the DEAE-cotton. One route of preparation generally known is that of. dissolving the 2-chloroethyldiethylamine hydrochloride in water, padding the cotton fabric, immersing the wet-impregnated cotton in sodium hydroxide, and keeping the cotton immersed until it reacts. This we find inefficient, mainly because it is a wet cure, multiple step process. Another process involves elevating the temperature ofthe sodium hydroxide. The Berni et al. process (see above) presents the idea of preparing soda-cellulose, and while Wet with a nonaqueous solvent, solvent exchanging in order to employ the solvent that the 2-chloroethyldiethylamine is compatible with and again submer-ging the soda-cellulose impregnated (still wet) in the 2-chloroethyldiethylamine solution in a nonaqueous solvent and retain it immersed until reaction occurs.

Now we have found the manipulations of the prior art to be unnecessary, and We have produced the DEAE derivatives of cotton and other cellulosic material and starch in amore efficient manner. Firstly, 2-chloroethyldiethylamine hydrochloride is mixed with aqueous sodium hydroxide, or potassium hydroxide in a molar ratio of about from 1021 to 1:1, thereby producing the insoluble 2-chloroethyldiethylamine which is a liquid at room temperature. Once this product is prepared it is separated from the aqueous layer and mixed with water, shaken vigorously for about from 5 to 20 minutes at room temperature and 3 the entire quantity is converted to the water-soluble diethylaziridinium chloride. Alternately, the DEAE hydrochloride may be mixed with base solution of the desired concentration and the mixture sha'ken until solution is homogeneous.

APPLICABLE EQUATIONS a Et H01 NaOH N-CHgCHzCl Et (insoluble) Shake in water to produce Cell-OH+ DAC Cell-O-CHzCHz-N NaOH Et cen-o-ornom-N (DEAE-Cellulose) Et The water-soluble DAC is most useful in padding onto polysaccharide materials at concentrations up to a saturated solution (about 2 M, or approx. 27%). This reaction can be further accelerated by adding base to the padding solution. Once the polysaccharide is impregnated, reaction can be carried out at the preferred 80 to 140 C. range. The time required is usually about 5 minutes. The reaction can also be carried out at room temperature; 16 hours is a convenient time to achieve the same reaction. The impregnating and reacting steps can be repeated as required to obtain the desired degree of substitution. The reacted polysaccharide can be water-washed to remove unreacted materials.

Diethylaminoethyl cellulose prepared by this process retains 75 to 100% of the original breaking strength. The wrinkle recovery properties of cellulosic fabric treated according to the process of this invention were essentially the same as those of the untreated fabric.

The following examples are provided to illustrate what can be done with the process of the invention, and they should not be construed as limiting the invention in any manner whatever.

EXAMPLE 1 A sample of cotton printcloth weighing 7.7 grams was utilized. It was thoroughly impregnaed with an aqueous solution containing 1 mole of diethylaziridinium chloride, and one equivalent of sodium carbonate in 1000 ml. of solution. The wet-impregnated fabric was passed through squeeze rolls to obtain a wet-pickup of 120%. The wet sample was placed in an oven and heated for 5 minutes at 140. The fabric was then removed from the oven and washed with flowing tap water for 30 minutes, and dried in air at room temperature. The nitrogen content of this sample was 0.2%. Similar results are obtained with raw stock or yarn.

EXAMPLE 2 Using the solution of Example 1 the once-treated, washed and dried fabric of Example 1 was processed a second time exactly as before. Analysis of the twicetreated sample indicated a nitrogen content of 0.36%.

EXAMPLE 3 Using the solution of Example 1 the twice-treated washed and dried fabric of Example 2 was processed a third time exactly as before. Analysis of the thrice-treated sample indicated a nitrogen content of 0.48%.

EXAMPLE 4 Using the technique of Example 1 but varying the reagent solution so that it would contain 1 mole of DAC and 1 mole of NaOH in 1000 ml. of solution, a cotton printcloth sample was processed as before. Analysis of this sample indicated a nitrogen content of 0.48%.

EXAMPLE 5 Using the solution of Example 4 the once-treated, washed and dried fabric of Example 4 was processed a second time exactly as before. Analysis of the twicetreated sample indicated a nitrogen content of 0.65%.

EXAMPLE 6 Using the technique of Example 1 but varying the reagent solution so that it would contain 1 mole of DAC in 1000 ml. of solution and no base, three samples of cotton printcloth were processed as before. One sample was washed and analysis indicated a nitrogen content of 0.2%.

EXAMPLE 7 Using the solution of Example 6 the two remaining samples of printcloth from Example 6 were given a second treatment without being washed between treatments. One piece was washed and was found to contain 0.38% nitrogen.

EXAMPLE 8 Using the solution of Example 6 the remaining sample of printcloth from Example 7 was given a third treatment without being washed between treatments. It was washed and was found to contaon 0.57% nitrogen.

EXAMPLE 9 The solution and technique of Example 5 were applied to a cotton printcloth; however, the fabric was dried in air for 16 hours and then heated for 5 minutes at 140 C. Analysis of this sample indicated a nitrogen content of 0.15%.

EXAMPLE 10 The solutions and technique of Example 5 were applied to cotton printcloth; however, the fabric was dried in an oven for 5 minutes at C. Analysis of this sample indicated a nitrogen content of 0.15%. There was no significant difference between the finished sample of Example 10 and the sample of Example 11.

EXAMPLE 11 A solution containing 2 M diethylaziridinium chloride was prepared as previously described and cooled to 10 C. or lower but not to the freezing point. To this solution was added an equal volume of 2 N sodium hydroxide solution cooled to the same temperature. The low temperature slows the rate of hydrolysis of diethylaziridinium chloride to the corresponding alcohol. The solution were well mixed and a sample of cotton printcloth was impregnated with the solution which was maintained at 10 C. or below. The remainder of the operation was exactly as described in Example 1. The washed and dried sample of treated fabric contained 0.90% nitrogen.

EXAMPLE 12 A swatch of rayon fabric was treated using the technique of Example 1 with the solution of Example 4. The nitrogen content of the reacted and washed sample was 0.73%.

EXAMPLE 13 Woodpulp from slash pine, 10 g., was impregnated with the solution of Example 1 by soaking the pulp in the solution for about 30 minutes. The pulp was separated by vacuum filtration and pressed until the wet pickup was about The pulp was then spread in a thin layer on a crystallizing dish and placed in an oven at 140 C. for minutes, then washed and air-dried at room temperature. The nitrogen content of this sample was 0.39%.

EXAMPLE 14 Chemically pure corn starch, 10 g., was soaked in the solution of Example 6 for 30 minutes. The reacted starch was separated from the solution by filtration and treated as described in Example 13. The nitrogen content of this sample was 0.83%.

EXAM'PLE 15 A quantity of 17.2 g. (0.10 mole) of 2-chloroethyldiethylamine hydrochloride was added to 100 ml. of 2 normal aqueous sodium hydroxide, and the mixture was shaken 15 minutes. A swatch of cotton fabric was treated with this solution by the process of Example 1. The analysis of this cotton sample showed a nitrogen content of 0.37%.

EXAMPLE 16 Using the technique of Example 4 but varying the solution so that it would contain 1 mole of DAC and 1 mole of potassium hydroxide in 1000 ml. of solution, a cotton printcloth was processed as before. Analysis of this sample indicated a nitrogen content of 0.42%.

We claim:

1. A process for the preparation of diethylaminoethyl derivatives of polysaccharides, comprising:

(a) mixing aqueous Z-chloroethyldiethylamine hydrochloride with aqueous alkali hydroxide to produce a water-insoluble liquid product, 2-chlorodiethylamine,

(b) separating the water-insoluble product from the contaminants,

(c) mixing the water-insoluble product with about five times its weight in water and shaking thoroughly for about 15 minutes thereby forming an aqueous solution of diethylaziridinium chloride,

(d) impregnating at room temperature of a polysaccharide material selected from the group consisting of cotton cellulose, wood cellulose, starch, and regenerated cellulose with the aqueous solution of watersoluble diethylaziridinium chloride from step (c) in the ratio of approximately 1 to 5, respectively, and

(e) dry curing the impregnated fabric.

rial.

2. The process of claim 1 wherein the polysaccharide is cotton cellulose.

3. The process of claim 1 wherein he polysaccharide is wood cellulose.

4. The process of claim 1 wherein the polysaccharide is regenerated cellulose.

5. The process of claim 1 wherein the polysaccharide is starch.

6. A process for the preparation of diethylaminoethyl cotton fabrics, comprising:

(a) mixing aqueous 2-chloroethyldiethylamine hydrochloride with aqueous alkali hydroxide to produce a water-insoluble liquid product, 2-chlorodiethylamine,

(b) separating the water-insoluble product from the contaminants,

(c) mixing the water-insoluble product with about five times its weight in water and shaking thoroughly for about 15 minutes thereby forming an aqueous solution of diethylaziridinium chloride,

(d) impregnating cotton fabric with the aqueous solution of step (c) and (e) dry curing the impregnated fabric.

OTHER REFERENCES Roberts et al., Textile Research Journal, vol. 40, No. 3, March 1970, pp. 237-243.

GEORGE -F. LESMES, Primary Examiner J. CANNON, Assistant Examiner U.S. Cl. X.R.

8120; 260231 R, 231 A, Dig. 6, 2.1 R, 2.2 R, 2333 R