US3026169A - Manufacture of viscose rayon - Google Patents

Description

in sh..- r

United States Patent Ofifice 3,026,169 Patented Mar. 20, 1962 3,026,169 MANUFACTURE OF VISCOSE RAYON Brewster B. Eskridge, Candler, N.C., assignor to American Enka Corporation, Enka, N.C., a corporation of Delaware No Drawing. Filed Mar. 23, 1960, Ser. No. 16,938 8 Claims. (Cl. 18-54) This invention relates generally to the production ofshaped articles of regenerated cellulose from viscose and more particularly to the production of high tenacity viscose rayon yarn. In recent years, extensive research has been conducte by all rayon producers in an effort to improve the prod- A most effective modifier is disclosed in copending application Serial No..609,792, filed September 14, 1956, and owned by the common assignee. This modifier is a quaternary derivative of an ethoxylated amine. Compounds of this type have the following general formula:

tonmnonn R-N R/ wcnHznohwherein R is an alkyl, aryl, or alicyclic radical of at least six carbon atoms, and usually not more than twenty; R is an alkyl radical containing one to three carbon atoms; Z represents an anion having substantially no surface activity such as hydroxide, halide, sulfate, acetate, etc.; .1: and y are whole numbers; X plus y is 2 to 50; and n is also a whole number of one to three. These compounds are known in the trade as Ethoquads. For further description and the method of preparation of these compounds, reference should be had to the aboveidentified copending application.

In the use of the Ethoquads and other modifiers, the improved strengths that have been obtained have been at the expense of ease in manufacturing. The modified yarns are tender until completely regenerated; therefore, the spinbath acid concentration must be controlled to insure good spinnability, satisfactory yarn quality, and high strength. In most cases, the range of spinbath acid concentration which achieves these results is very narrow and usually just above the minimum acid concentra tion necessary to maintain satisfactory spinnability. With the constant changing of the acid spinbath, it can be seen that it is very difficult to maintain the spinbath acid within the required narrow range. If the acid is outside of this range, there will be a reduction in satisfactory spinnability and, in some cases, the viscose solution may not evenbe spinnable. In addition, there will be a reduction in quality and strength. Ali o-f these are obviously undesirable, out previously were thought to be characteristic of modified spinning.

It is therefore an object of this invention to provide a viscose spinning solution which may satisfactorily be spun over a wider range of acid concentrations.

It is a further object of this invention to provide a modified viscose spinning solution having incorporated therein an additive which permits improved spinning over a wider range of acid concentrations.

An additional object of this invention is to provide a process for making viscose rayon yarn that is free of the difficulties of the prior art.

A further object of this invention is to provide a process for manufacturing viscose rayon yarn wherein the spinbath acid concentration is not as critical as in the processes of the prior art.

An additional object of this invention is to provide a new and improved additive for the viscose process which enables satisfactory spinning over a wider range of spinbath acid concentrations.

These and other objects will become apparent to one skilled in the art from a reading of the following detaileddescription of this invention The above objects of this invention are accomplished by incorporating into a viscose spinning solution a sodium lignosulfonate and a quaternary derivative of an ether;- ylated amine. The thus improved viscose spinning solution is extruded through a spinneret into a zinc containing acid coagulating bath to form filamentary material therefrom. They are then preferably passed into a second bath containing a hot sulfuric acid where they are stretched. The regeneration of the yarn is thus completed while the filaments are under tension. Thereafter the yarn is collected in package form.

- The above identified quaternary derivative of an ethoxylated amine that is incorporated into the viscose spinning solution is described in application Serial No. 609,792.

These compounds, known in the trade as Ethoquads, are obtained by quaternizing with suitable alkyl compounds alkali-soluble ethyleneoxide adducts of primary fatty amines. These adducts and their method of preparation are described in US. Patent No. 2,852,334, and are known in the trade as Ethomeens.

Examples of these viscose modifiers are obtained by the following reactions:

0 H; C 11 0MB:

Ethomeen 0/12 on, onzonzm n I Ethoquad 0/12 R derived from coconut oil 2 plus y=2 (2) )CHzCHzOhH (CHzCHzOhH R-N 011301 R7N\ o1 CHQC 2OM a (c z zmy Ethomeen 0/20 Ethoquad 0/20 R derived from coconut oil :2: plus y=10 (3i /(CHGH O),H }CH2CH2O)XH RN CHaCl R;N Ol- CHz CHaObH CH; iCH cHzm H Ethomeen (3/25 Ethoquad (3/25 E derived from coeonutrfatty acids I plus y=15 (6) (CH2CH20).:H R-N CHaCl Hz C H2 0 yH Ethomeen T/60 C (CH2CH20) H Ethoquad T/20 R derived from tallow :r plus 11:10

The sodium lignosulfonates are obtained by the sulfonation of alkali lignin. These compounds are known in the trade as Polyfons. It is possible to use these compounds with a variety of degrees of sulfonation. For example, those compounds with one-half, one, two, three, or four moles of sulfonation per lignin unit of 840 grams, may be used in this invention. These compounds are known as Polyfon H, O, T, R, and F, respectively.

In order to accomplish the objects of this invention, these compounds are preferably injected into the viscose spinning solution just prior tospinning. However, they may also be added at any point in the preparation of the spinning solution. The quaternary derivatives of an ethyloxylated amine may be added inv amountsof about 0.5% to 4.0%, based on oven dry, recoverable cellulose: in the viscose spinning solution (hereinafter referred to as (CIV).

The sodium lignosulfonates are preferably incorporated in amounts of about 0.5% to- 3.0% (CIV) into. the viscose spinning solution". Larger or smaller amounts of either compound may be used without materially affecting the physical properties of the resulting yarn.

Beneficial results may be obtained by using a viscose spinning solution containing 4 to 8% cellulose, 4 to 8% total alkali content expressed as NaOH, and 1.210 3.25% total sulfur content. Higher or lower concentrations may be used if desired without materially affecting the results. The viscose spinning solution may have an ammonium chloride number of 10 to 21 and a spinning viscosity of 30 to 100. Higher or lower maturities and viscosities may also be used without appreciably affecting the results of this invention. The above concentrations are based on the weight of the viscose spinning solution.

The freshly extruded filaments are permitted to travel through the acid or coagulating-regenerating bath for a distance of 8 to 200 inches; however, an immersion of 10 to-60 inches is preferred. The acid coagulating bath should preferably contain sulfuric acid, sodium sulfate, and zinc sulfate. Other materials, such as magnesium sulfate, may be added for special purposes, if desired. The sulfuric acid content may vary from about 2.5 to 7.0%, the sodium sulfate from about 5.0 to 20.0%, and; the zinc sulfate from about 3.0 to 15.0%. It should be understood that these are preferred ranges and that higher or lower concentrations, which concentrations are based on the weight of the coagulating bath, may be used without departing from this invention. The temperature of this bath generally Will range from about 30 to 70 C., and the preferred temperature is about 50 C.

The speed at which the filaments may be spun should preferably not be in excess of 90 meters per minute because of possible filament damage. However, the speed should not be so low as to render the process uneconomical. Usually a speed of from 35 to 65 meters per minute will economically produce an excellent yarn. With the higher speeds, it. is usually desirable to use a spinning tube immersed in the acid coagulating bath. Such a tube is described in U.S. Patent No. 2,908,937.

The treatment of the yarn following the second bath is conventional and forms no part of this invention. It normally consists of a. washing step or steps, a desulfurizing step, a finishing step, and a drying step. If the The second or regenerating bath may be water, 1 to Q 6% sulfuric acid, or substantially diluted acid coagulating bath. It may also contain 1 to 6% sulfuric acid, 0.0 to 1.5% zinc sulfate, and 0.0 to 3.0% sodium sulfate. A preferred composition for this bath is about 4.0%, sulfuric acid, 1.2% sodium sulfate, and 0.3% zinc sulfate.

'The temperature of this bath may vary from 50 to 100 C., with the preferred temperature being from 85 to 100. C. Stretch preferably is imparted to the filaments while they are immersed in the second bath. This stretch may vary from 20 to 150% and preferably is from 100 to 110%,

yarn is, to be used for-textile purposes, it may include a bleaching step.

This invention will be, more clearly understood by ref erence to the examples and discussions which follow. These examples are given merely for purposes of illustration and are not to be construed as limiting the scope of this invention.

EXAMPLE I Several viscose spinning solutions containing 7.5% cellulose, 5.5% total alkali expressed as NaOH, 2.3% total sulfur, and 2.5% (CIV) of Ethoquad C/25 were prepared in a conventionaLmanner. The solutions had maturities of 16 to 18 ammonium chloridenumbers and viscosities 'of' 40 to .50 seconds at 20 C. The-viscoses were spun into an 1100 denier-+720 filament yarn, after drawing, by extrusion through. a spinneret. with. 60 microns. diameter holes into several acid coagulating baths. The sulfuric acid concentration of these baths were varied as shown in the following Table 1. Each bath contained 9.0% sodium sulfate and 9.0% zinc sulfate. The bath temperatures were 50 C., and the total yarn travel therein was between 20 and 30 inches. From these baths the yarns were led to first feed wheels, thence to second acid baths at 92 C., and the yarn travel therein was 40 inches. These second acid or regenerating baths contained 4.0% sulfuric acid, 1.2% sodium sulfate, and 0.3% zinc sulfate. The yarns were then led to second feed wheelsrotating at peripheral speeds of 40 meters per minute and thence to bobbins: or spools. The differences in peripheral speeds. of the 'first and second feed wheels were such as to impart to stretch to the yarns in the second baths and to create tension on the yarns immediately before the-second feedwheels. The peripheral speeds of the bobbins or spools. were such as to maintain. the same tension on the yarns as they were collected. "The yarns were aftertreated in the conventional manner. Two strands of each yarn were plied together ina. conventional manner to form: 15 ,x 15 cords. The following table illustrates the oven dry strengths and 'deniers of the samples. for each sulfuric acid concentration of. the acid coagulating bath.

EXAMPLE n Viscose spinning solutions of compositions similar to those described in Example I were prepared, except that 2.5% (CIV) of Polyfon O was injected into the solution. The viscoses were spun and treated as in Example I, except the sulfuric acid concentrations of the acid, coagulating bath were as shown in Table II. This Table II illustrates the strength and denier of '15 x 15 cords formed from the yarns at the various acid concentrations.

EXAMPLE III Viscose spinning solutions of compositions similar to those described in Example I were prepared, except 2.5% (CIV) of Polyfon T was injected into the solution. The viscoses were spun and treated as in Example 1, except the sulfuric acid concentrations of the acid coagulating bath were as shown in Table III. This Table III illustrates the strength and denier of x 15 cords formed from the yarns at the various acid concentrations.

Table III Oven Sulfuric Acid (percent) Dry Denier Strength EXAMPLE IV Viscose spinning solutions of compositions similar to those described in Example I were prepared, except 2.5

(CIV) of Polyfon F was injected into the solution. The viscoses were spun and treated as in Example I, except the sulfuric acid concentrations of the acid coagulating bath were as shown in Table IV. This Table IV illustrates the strength and denier of 15 x 15 cords formed from the yarns at the various acid concentrations.

Table IV Oven Sulfuric Acid (percent) Dry Denier Strength From the foregoing examples, it can be seen that the compounds of this invention, when used in a viscose process, not only produce high strength but render the acid concentration of the acid coagulating bath less critical. This permits greater freedom in spinning and permits greater fluctuation in acid concentrations, thereby simplifying the control of the spinning operation. In addition, it permits spinning at lower acid concentrations, thereby reducing the cost of the operation. It can also be seen from these examples that yarn of desirable properties may be obtained at acid concentrations which are not just above the acid concentrations at which the modified viscose will not spin. This also simplifies the control of the spinning operation.

Many modifications may be made in this invention without departing from its spirit and scope. For instance, formaldehyde may be added to the acid coagulating bath, or it may even be used in an intermediate bath. It should be understood that this invention is to be limited only by the following claims.

What is claimed is:

1. A viscose spinning solution having incorporated therein about 0.5% to 4.0% CIV of a compound of the general formula:

wherein R represents an alkyl, aryl, or alicyclic radical containing at least six carbon atoms, R is an alkyl radical containing one to three carbon atoms, x plus y is two to fifty, x and y are whole numbers, n is a whole numher from one to three, and Z is a surface inactive anion, and a sodium lignosulfonate having about 0.5 to 4.0 moles of sulfonation per mole of lignin.

2. A viscose spinning solution according to claim 1 wherein about 0.5% to 3.0% CIV of the sodium lignosulfonate is incorporated into the viscose spinning solution.

3. A viscose spinning solution according to claim 1 wherein said lignosulfonate has one mole of sulfonation per mole of lignin.

4. A viscose spinning solution according to claim 1 wherein said lignosulfonate has two moles of sulfonation per mole of lignin.

5. A viscose spinning solution according to claim 1 wherein said lignosulfonate has four moles of sulfonation per mole of lignin.

6. A viscose spinning solution according to claim 1 wherein the quaternary derivative of an ethoxylated amine has the following formula:

C a z zmy in which R represents an aliphatic radical containing six to twenty carbon atoms, x and y are whole members, and x plus y is two to fifty.

7. A process of producing viscose yarn which comprises spinning a viscose solution, having incorporated therein about 0.5 to 4.0% CIV of a compound of the general formula:

wherein R represents an alkyl, aryl, or alicyclic radical containing at least six carbon atoms, R is an alkyl radical containing one to three carbon atoms, x plus y is two to fifty, x and y are whole numbers, n is a whole number from one to three, and Z is a surface inactive anion, and a sodium lignosulfonate having about 0.5 to 4.0 moles of sulfonation per mole of lignin, into an aqueous acid coagulating bath containing 2.5% to 7% sulfuric acid, 3 to 15% zinc sulfate, and 5 to 20% sodium sulfate, to form filamentary yarn therefrom, withdrawing said yarn from said bath, passing the same through a second hot bath while stretching, completing the regeneration of said yarn under tension, and collecting the same.

8. A process according to claim 7 wherein said quaternary derivative of an ethoxylated amine has the following formula:

R-N Cl Elod et al.: Reyon Zellwolle und Andere Chemiefasern, volume Jahrg. 1955, No. 33, page 322.

Claims (1)

1. 7. A PROCESS OF PRODUCING VISCOSE YARN WHICH COMPRISES SPINNING A VISCOSE SOLUTION, HAVING INCORPORATED THEREIN ABOUT 0.5 TO 4.0% CIV OF A COMPOUND OF THE GENERAL FORMULA: