US3657410A - Process for producing a high wet modulus viscose rayon - Google Patents

Abstract

PRODUCING HIGH WET MODULUS VISCOSE RAYON BY SPINNING A VISCOSE WHICH IS XANTHATED BY 29-35% BY WEIGHT (CELLULOSE BASIS) OF CARBON DISULFIDE. THE SPINNING SOLUTION CONTAINS ONE OR MORE FATTY OR CYCLIC MONOAMINES HAVING 1-6 CARBON ATOMS, OR ALKYLENE OXIDE DERIVATIVES OF SUCH AMINES, IN COMBINATION WITH ONE OR MORE ZINC COMPOUNDS WHICH ARE SOLUBLE IN SODIUM HYDROXIDE OF WATER IN AN AMOUNT GREATER THAN 0.05% BY WEIGHT. EACH OF THE ABOVE GROUPS OF MATERIALS MUST BE ADDED IN AN AMOUNT GREATER THAN 0.1, BY WEIGHT (CELLULOSE BASIS). SPINNING OCCURS INTO A SULFURIC ACID-SULFATE TYPE SPINNING SOLUTION CONTAINING MORE THAN 1% BY WEIGHT ZINC SULFATE. IN A PREFERRED EMBODIMENT, POLYETHYLENE GLYCOL IS ALSO ADDED.

Description

April is, 1972 TADAO SASAKURA ET AL PROCESS FOR PRODUCING A HIGH WET MODULUS VISCOSE RAYON Filed May 23, 1969 40 5'0 6'0 ACID CONCENTRATION OF FIRST BATH 5% Ed IQwQmIQEWEB 2%; @EEE 352 a ma FIG. 2

FIG. 3

FIG. 5

2 K-vALuE 0F PARTIALLY REGENERATED YARN 29 30 3| 32 33 34 35 3e CARBON DISULFIDE (BASED ON CELLULOSE) United States Patent US. Cl. 264-194 13 Claims ABSTRACT OF THE DISCLOSURE Producing high wet modulus viscose rayon by spinning a viscose which is xanthated by 29-35 by weight (cellulose basis) of carbon disulfide. The spinning solution contains one or more fatty or cyclic monoamines having 1-6 carbon atoms, or alkylene oxide derivatives of such amines, in combination with one or more zinc compounds which are soluble in sodium hydroxide or water in an amount greater than 0.05% by weight. Each of the above groups of materials must be added in an amount greater than 0.1% by weight (cellulose basis). Spinning occurs into a sulfuric acid-sulfate type spinning solution containing more than 1% by weight zinc sulfate.

d(gnda preferred embodiment, polyethylene glycol is also a e BACKGROUND OF THE INVENTION Field of the invention This invention relates to a process for producing a viscose rayon having excellent properties which comprises adding a zinc compound and an amine, or derivatives Hitherto several faults have been encountered with the use of viscose rayon, i.e., water resistance and alkali resistance. Accordingly, the dimensional stability of fabric formed thereof was not very good because of these properties. Many methods were suggested in order to improve these faults. These can roughly be divided into three groups, described below.

The first method of production involves the use of no modifier. Though the water resisting property and the alkali resistance are improved by this method, the spinning property is harmed. Accordingly, the production capacity of this method is poor, and fibrils are easily formed in the resulting fibers.

The second production method involves using formaldehyde as the modifier. This method has merits and faults similar to the first method, and has some difficulties in operation due to the use of formaldehyde.

The third production method involves the use of amines and derivatives thereof, etc. as the modifier. By the use of this method, the faults of the first and the second methods, that is, the problems with the spinning property and fibril formation were improved. However, though there are some improvements in the water resisting property and the alkali resistance, they were not satisfactory, as shown by contraction (during washing) of fabrics formed from materials thus produced. However, this problem could not be cleared up without losing other advantages, though further improvements in the water resisting property and the alkali resistance may be desired.

It is accurate to say that in methods using modifiers and combinations thereof as described above, it is not possible ice to produce high tenacity rayon (with respect to water res1st1ng property and alkali resistance), even when consideration is given to the fact that such methods are simllar to standard methods for producing high tenacity rayons.

SUMMARY OF THE INVENTION The present invention provides a process for producing a high wet modulus viscose rayon illustrating excellent physical properties, and which has a good crimping capacity. The process basically comprises spinning a viscose of a salt point lower than 7 and a 'y-Value lower than 57 which has been xanthated by 29-35% by weight (cellulose basis) of carbon disulfide, and which contains one or more fatty or cyclic monoamines having 1-6 carbon atoms, or alkylene oxide derivatives of said fatty or cyclic monoamines in combination with one or more zinc cornpounds which are soluble in sodium hydroxide or water in an amount greater than 0.05% by weight. The amine compounds and the zinc compounds must each be added in an amount greater than 0.1% by weight (cellulose basis), respectively. Spinning occurs into a sulfuric acidsulfate spinning solution which must contain greater than 1% by weight zinc sulfate.

When the specific viscose described is spun in combination with the amines and zinc compounds described, a synergistic effect is realized.

In certain preferred embodiments of the present invention polyethylene glycol is added to the viscose in an amount greater than 0.1% by weight (cellulose basis). The polyethylene glycol preferably has a molecular weight of 800-1700.

It is thus an object of the present invention to provide a novel method for producing a high Wet modulus viscose rayon.

It is a further object of the present invention to produce a high wet modulus viscose rayon illustrating an excellent crimping capacity.

It is still yet another object of the present invention to provide a novel high modulus viscose rayon.

Yet another object of the present invention is to provide a process for producing a high modulus viscose rayon which illustrates an improved water resisting and alkali resisting property.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional photographic plan of fibers produced by the process of the present invention.

FIG. 2. is a sectional photographic plan of fibers produced utilizing the prior art modifiers.

FIG. 3 is a plot illustrating the relationship between the -value of a partially regenerated yarn and the acid concentration.

FIG. 4 is a plot illustrating the relationship between the gel swelling value and the v-value of a partially regenerated yarn.

FIG. 5 is a plot illustrating the relationship between the amount of added carbon disulfide at xanthation and the dry strength of a resulting fiber.

FIG. 6 is a plot showing the relationship between the amount of added carbon disulfide at xanthation and the wet modulus at 5% elongation of the resultant fiber.

DESCRIPTION OF THE PREFERRED EMBODIMENT As the result of studies in the production of fibers which have a good spinning property, water resisting property and alkali resistance, which do not make fibrils and which yield a good hand with respect to fabrics produced therefrom, it has been discovered that fibers having a good spinning property, fibril formation, water resisting property, alkali resistance and other properties, as well as crimping ability (which could not be obtained until the present invention) can be obtained using a combination of modifiers containing a zinc compound in combination with a certain set of conditions with said combination of modifiers.

Unless otherwise indicated, all percents are by weight.

The first characteristic of this invention is in the com.- bination of modifiers, that is, the combination of a zinc compound and an amine, or derivative thereof, and polyethylene glycol; or in the combination of a zinc compound and an amine or derivative thereof (no polyethylene glycol).

In these combinations, though the former exhibits a more preferred effect, the objects are also attained by the latter.

The second characteristic of this invention is using a viscose having a low ripening degree produced by adding a lowered amount of carbon disulfide at xanthation, and a spinning solution containing a large amount of zinc. Where a viscose having a high ripening degree and a spinning solution containing a small amount (or free from) Zinc is used, it is impossible to expect improvements of each characteristic, especially improvements in the spinning property.

With reference to the effect of the combined modifiers used in this invention, the mechanism thereof is very complicated and is unclear. With reference to the effects of regeneration, coagulation and dehydration, the process of this invention, in comparison with other methods, has a tendency to delay regeneration and to lower the gel swelling value (at the same point) in the remaining 'y-value of the partially regenerated yarn.

The effect due to the combined modifiers in the process of this invention can be determined by the characteristics of the resulting fibers, the fibers which exhibit excellent characteristics (produced by this invention) have a non-objective sectional form, wherein substantially the whole fibers have a circular small pro ection. Crimping results from this asymmetric sect1on. On the other hand, in using modifiers outside this invention, such a specific cross-section is not obtained, and conse quently crimping does not occur. The relationship between the shape of the section and characteristics of the fibers is not clear. However, to obtain such a specific section does prove singularity of coagulation, dehydration and regeneration at spinning in the present invention.

FIG. 1 and FIG. 2 show enlarged sectional photographic plans of fibers produced by skin staining.

FIG. 1 is a sectional photographic plan of fibers produced by the process of this invention.

FIG. 2 is a sectional photographic plan of fibers produced using a modifier other than of the process of this invention.

FIG. 3 shows the relationship between the 'y-value of partially regenerated yarns and the acid concentration, wherein A represents the 'y-value of a partially regenerated yarn produced by the process of this invention and B represents the 'y-value of a partially regenerated yarn produced using a modifier other than of the process of this invention.

FIG. 4 shows the relationship between the gel swelling value of the -value of a partially regenerated yarn wherein A represents the gel swelling value of a partially regenerated yarn produced by the process of this inven tion and B represents the gel swelling value of a partially regenerated yarn produced using a modifier other than of the process of this invention.

FIG. 5 and FIG. 6 show the relationships between the amount of added carbon disulfide at Xanthation and the dry strength of the resulting fiber, and the wet modulus at 5% elongation, respectively.

The fine structure of the fibers produced by the process of this invention is not too different (in crystal length and degree of crystallization) from that of fibers produced using modifiers outside this invention. However, the orientation degree of the whole fibers (obtained by birefringence measurement) and the degree of orientation of the crystal portions (obtained by X-ray measurement) are large. Moreover, the degree of orientation of the amorphous portion of the fibers calculated from the above values is especially large.

The characteristics of the fibers depends on the characteristics of the amorphous portions thereof. Accordingly, it is believed that the improvements in the characteristics of the amorphous portions are closely connected with the improvement of characteristics of the fibers as a whole. Accordingly, when the degree of orientation of the amorphous portions is large, the improvement of the characteristics of the amorphous portions thereof (which largely contributes to wet modulus at 5% stretching, which is a criterion of water resisting property, alkali resistance and fiber strength, etc.) is marked.

As described above, the viscose rayon in the process of this invention has a good spinning property. Consequently the degree of homogenization of the resulting fibers is very high, and the resulting fibers do not include abnormal fibers and other impurities. Further, the fibers have a high stretch strength and good anti-fibril property, as well as a good water resisting property and alkali resistance. Consequently, the dimensional stability of the resulting fabric formed therefrom is excellent. Furthermore, since the fibers of the present invention have crimping ability, productivity at spinning and weaving is good, and the fabric has good hand. Accordingly, the industrial value of the present invention is great.

The invention will be explained in more detail by the following.

This invention relates to a process for producing a high wet modulus viscose rayon having a good crimping ability, the rayon process being characterized by spinning a viscose xanthated with 29-35% by weight (based on the cellulose) of carbon disulfide at a ripening degree of less than 7 of the salt point, and less than 57 of the value; which contains more than 0.1% by weight (based on the cellulose) of one or more fatty or cyclic monoamines having 1-6 carbon atoms; or alkylene oxide derivatives of said fatty or cyclic monoamines; and 0.1% by weight (amount of Zinc based on the cellulose) of one or more zinc compounds which dissolve in a sodium hydroxide solution or in water in an amount of more than 0.05% by weight; either together with, or without, more than 0.1% by weight (based on the cellulose) of polyethylene glycol; into a sulfuric acid-sulfate type spinning solution, with a high zinc sulfate concentration, and stretching using a second bath.

As the modifiers added in the viscose, any Zinc compound is preferred if it is soluble in a sodium hydroxide solution or water in an amount of more than 0.05%. Examples are sodium zincate, zinc acetate, zinc sulfate, zinc oxalate and zinc phosphate. Two or more compounds may be used, though one compound is sufficient. However, the effect is not as improved if two or more compounds are used.

Though there is not any restriction upon the point of adding the zinc compound(s), it is preferable to add the zinc compound(s) just before spinning.

The amount of zinc compound(s) must be over 0.1% calculated as zinc (based on the cellulose). When two or more compounds are used, the total amount must be over 0.1%. If it is less than 0.1% the synergistic effect thereof with the amine compounds or the polyethylene glycol becomes poor. Further, if it is over 10% the synergistic effect is no longer improved and is economically wasteful. It is preferably l-S%. The main portion of the added zinc compounds dissolve in the spinning solution at spinning. Accordingly, since they are used as zinc in the spinning solution, the economic load is small.

The amine compounds used are aliphatic or cyclic monoamines having 1-6 carbon atoms, or alkylene oxide derivatives thereof. If amines having 7 or more carbon atoms are used, the synergistic effect thereof with the zinc compounds and the polyethylene glycol unexpectedly greatly lowers. Further, the synergistic effect of the amines with the zinc compounds and polyethylene glycol is superior to that of the alkylene oxide derivatives thereof. Examples of said amine compounds include monomethylamine, dimethylamine, diethylamine, propylamine, cyclohexylamine and butylamine and derivatives thereof having added 3 moles of, for example, ethylene oxide. Any alkylene oxide can be used, and the mole ratio can vary. Though only one of these modifiers is preferably used, two or more thereof may be used. However, the effect thereof is not as improved if two or more are used.

Though there is not any restriction upon the time of addition of these modifiers, it is preferred to add them just before spinning.

The amount of amine compounds described above must be greater than 0.1% (based on the cellulose). When two or more compounds are used, the amount of both must be over 0.1% (combined). If less than 0.1% is used, the synergistic effect thereof with the zinc compound and polyethylene glycol bocomes poor, and if it is over 10%, the synergistic effect is no longer improved. It is preferably 0.5-4%.

For the polyethylene glycol, a suitable molecular weight is 8001700. There is no restriction o nthe point of adition, but it is most preferably added just before spinning. The amount thereof must be over 0.1% (based on the cellulose). If it is less than 0.1%, the synergistic effect thereof with the zinc compounds and the amine compounds is poor, and if it is over 10%, the synergistic effect is no longer improved. Preferably, it is .33%.

The modifiers described above should not be used alone, but one or more of each compound should be used, or else one or more zinc compounds and one or more amine compounds should be used. The etfects described above are not obtained by any other use. In essence, the polyethylene glycol use forms a preferred embodiment, but polyethylene glycol is not essential.

The amount of carbon disulfide at xanthating must be over 29% but less than 35% (based on the cellulose), preferably 30-34%. If it is less than 29%, the characteristics of the viscose deteriorate, and if it is over 35%, the characteristics of the resulting fibers deterioriate.

The viscosity of the viscose is most preferably 50-400 seconds. When the viscosity thereof is lower, it can still be used by making the conditions highly acid or with a high sodium sulfate content. However, it is preferred to avoid ranges outside said range in view of the spinning property and the uneconomical point of requiring acid or the sulfate.

The ripening degree is less than 7 of the salt point and less than 57 of the -value, and can correspond to lower ing of the acid content and the sodium sulfate content in the spinning solution as a lowering of the salt point and the -value. When the salt point and the 'y-tvalue are each higher than 7 and 57, the spinning property lowers as well and the orientation effect by stretching is not suitable. Further, the wet modulus at stretching (which is the criterion of the water resisting property and the alkali resistance of the resulting fibers) has a tendency to be lowered.

The spinning speed is preferably less than 60 m./min. When the spinning speed is too high, abnormal fibers are easily formed, and this is to be avoided.

The length of the first bath is preferably more than cm. If it is too short, it is necessary to provide means for controlling coagulation, dehydration and regeneration until stretching takes place. Consequently, the process is not as easy to use if these complicated steps must be added.

The acid concentration in the first bath is preferably less than 7%. The most suitable concentration will be determined depending upon the ripening degree of the viscose, the viscosity, the percentage of cellulose and the percentage of alkali in the viscose. When the percentage of alkali in the viscose is large, the most suitable condition is most often more than a 7% acid concentration. For instance, when in Example 1 the alkali percentage in the viscose was altered to 8%, the most suitable sulfuric acid and sodium sulfate concentration were 8% and 17%, respectively. However, this should be avoided since the 5% wet modulus has a tendency to decrease, and economic disadvantages occur in this case. The concentration of the sodium sulfate is preferably less than 12%, and is dependent upon the acid concentration. When the alkali concentration in the viscose is very high, the most suitable sulfate condition is generally OIVBI 12%. However, this should be avoided for the same reasons as in the case of the acid concentration.

The concentration of zinc sulfate in the first bath must be over 1%, and is generally less than 12%. If it is less than 1%, abnormal fibers are formed, nozzles are stopped up and spinning property lowers. Further, the orientation of the fibers by stretching is not effective, and the characteristics of the fibers deteriorate. If it is higher, loss by scattering increases. Accordingly, the concentration of zinc sulfate is most preferably 3-5%.

The temperature of the first bath is most preferably 20- 50 0, depending upon the thermal economy desired.

As the second bath, a regeneration bath having a low acid concentration, about 0.1-5% sulfuric acid, 0-l0% sodium sulfate and 05% zinc sulfate and a high temperature is used, by which means drafting is carried out. The temperature is generally 60-100 C.

The following examples are offered to explain the present invention in greater detail.

EXAMPLE 1 After a wood pulp having approximately a degree of polymerization of 800 was steeped in a 17.5% solution of sodium hydroxide at 20 C. for minutes, the pulp was pressed to 2.7 times, based on a dry pulp, and shredded at 20-50 C. for 60 minutes. To the resulting alkali cellulose, 33% carbon disulfide (based on said alkali cellulose) was added. After xanthating at 2028 C. for minutes, 5% zinc acetate, 3% of dimethylamine, 2% of polyethylene glycol, dissolving alkali and water were added thereto to produce a viscose containing 7% cellulose and 6% alkali by dissolving at 13 C. for 3 hours. The viscosity of the resulting viscose was 280 seconds.

After filtration and ripening till the viscose had a 5.9 salt point and a 51 -y-value, the viscose was spun at 30 m./min. using a first bath containing 5% sulfuric acid, 7% sodium sulfate and 4% of zinc sulfate at 40 C. The spun viscose was then stretched using the second bath. A fiber A was produced, after refining and drying, by known methods. A fiber B- was produced with the same conditions but using an equal amount of dimethylamine and polyethylene glycol. A fiber C was produced with the same conditions but using only the same amount of zinc acetate. A fiber D was produced with the same conditions except using the same amount of zinc acetate and polyethylene glycol. The characteristics of these fibers are set out in the following description. A 5% W.M. in the table and examples means the wet modulus at 5% stretch ing. The crimping number means the number of crimps developed when a yarn bundle cut in a 10-cm. piece after stretching is thrown into water at normal temperature. Further, data of a typical high web modulus marketed fiber is shown.

Enlarged sectional planes of fiber A of this invention and fiber B of the prior art are shown in FIG. 1 and FIG. 2, respectively. Fiber B has a circular section, while fiber A of this invention has an asymmetric circular section with a small projection.

Further, in FIG. 3 and FIG. 4, the remaining -value and the gel swelling value of the partially regenerated yarn produced by varying the acid concentration of the first. bath during preparation of fibers A and B are shown, respectively. The partially regenerated yarn of fiber A of this invention gives a high remaining 'y-value at every acid concentration, and a low gel swelling value at the same 'y-value (when compared with the partially regenerated yarn of fiber B). This shows that the fiber of this invention has a good stretching property and a good orientation property.

8 EXAMPLE 4 To an alkali cellulose produced by the same procedure as in Example 1, 35% carbon disulfide was added and xanthating was carried out at 20-28 C. for 120 minutes. Then 3% dimethylamine, 5% zinc sulfate, 2% polyethylene glycol, dissolving alkali and water were added to produce a viscose containing 7% cellulose and 6% alkali. After filtration and deaeration, ripening was carried out Orientation Dry Wet degree of Dry clon- Wet clon- Knot 5% amorphous Crimping strength gation strength. gation. strength W.P. part, number/ Fiber Denier g./d. percent g./ percent g./d. g./d percent 10 cm.

A 1. 5.6 10 4 0 11 2. 6 1.5 40 12 B 1.5 4.4 2.9 18 2.3 0.6 34 0 C 1.5 2.6 11 1.6 13 1.6 0.6 25 0 1. 6 3.0 10 2.1 11 1. 6 0.8 27 3 C) 1. 5 4. 6 15 3. 2 16 2. 2 0.7

Marketed fiber.

EXAMPLE 2 till the viscose had a 6.0 salt point and a 52 v-value. The

To an alkali cellulose produced by the same procedure as in Example 1, 34% carbon disulfide was added, and

xanthating was carried out at 20-30 C. for 120 minutes.

cose had a 6.5 salt point and a 53 'y-value. The viscosity of this viscose was 180 seconds. This viscose was spun at 30 m./min., using a first bath containing 6% sulfuric acid, 10% sodium sulfate and 4% zinc sulfate at C. Stretchviscosity of this viscose was 350 seconds. This viscose was spun at 30 m./min. using a first bath containing 4% sulfuric acid, 8% sodium sulfate and 4% zinc sulfate at 35 C. Stretching was carried out to 170% in the second bath. The fiber was refined and dried to produce Fiber A. Fiber B was produced under the same conditions but using the same amount of dimethylamine and polyethylene glycol. The characteristics of the yarns were as follows.

D ing was to 150% of 1ts original length 1n the second bath. Dry 2: 5% Crimping Then the fiber was refined and dried to produce fiber A. 30 Fiber Denier ax} z g yg, fi n l Fiber B was produced under the same conditions but using p only the same amount of cyclohexylamine. The character- A 11 24 -4 13 B 1.5 4.3 13 2.0 0.8 0 istics of these fibers were as follows.

Dry Wet Dry e1on- Dry elon- Knot 5% Crimping strength, gation, strength, gation, strength, W.M., number/ Fiber Denier g./d. percent g./d. percent g./d. g./d. 10 cm.

A 1. 5 4.8 12 3. 4 15 2. a 1. 0 25 B 1.5 4.0 15 2.7 18 2.1 0.6 0

EXAMPLE 3 FIGS. 5 and 6 show a plot of the dry strength and wet To an alkali cellulose produced by the same procedure as in Example 1, 32% carbon disulfide was added and Xanthating was carried out at 20-38 C. for 120 minutes. Then 3% of a compound produced by adding 3 moles of ethylene oxide to butylamine, 4% zinc acetate, 4% polyethylene glycol, dissolving alkali and water were added 5 thereto to produce a viscose containing 7% cellulose and 6% alkali. After filtration and deaeration, ripening was carried out till the viscose had a 5.5 salt point and a 48 'y-value. The viscosity of this viscose was 220 seconds.

The resulting viscose was spun at 35 m./min. using a first modulus at 5% stretching of the fibers produced by spinning and stretching under the same conditions but with varying the amount of carbon disulfide used for xanthating the alkali cellulose. In this case, very high strength and wet modulus were provided when the amount of carbon disulfide was in the range 29-35%, and the spinning property was also excellent in this range.

To further aid in an understanding of the present invention, the conditions of the second baths utilized throughout the exmples are set out below:

SECOND BATH CONDITIONS Sodium Zine Tempersulfate, sulfate, ature, percent percent C Dry Wet Dry elon- W elon- Knot 5% Crimping strength, gatlon, strength, gation, strength, W.M number] Fiber Denier g./d. percent g./d. percent g./d. g./ 10 cm Sulfuric Sodium Viscosity, acid, sulfate, seconds percent percent Further, when, in Example 4, the cellulose and the alkali concentration was altered to 6% and 5.3%, respectively, the viscosity of the viscose lowered to 180 seconds. Under this condition, the most suitable sulfuric acid and sodium sulfate concentration was 4.5% and 11%, respectively.

What is claimed is: 1. A method for producing a high wet modulus viscose rayon comprising:

preparing a viscose solution having a salt point lower than 7, a gamma-value lower than 57 and which is xanthated by about 29 to 35% by weight of carbon disulfide, said solution consisting essentially of from 0.1 to by weight of at least one amino compound selected from the group consisting of (a) fatty monoamines having from 1 to 6 carbon atoms, (b) cyclic monoamines having from 1 to 6 carbon atoms and (c) said fatty and cyclic monoamines having ethylene oxide added thereto, in combination with from 0.1 to 10% by weight of at least one zinc compound selected from the group consisting of sodium zincate, zinc acetate, zinc sulfate, zinc oxalate, and zinc phosphate, the weight percentages of the contents of said viscose solution being based upon the weight of cellulose in said viscose solution; spinning said viscose solution by means of a spin bath composition consisting essentially of zinc sulfate in a concentration of from 1 to 12%, sodium sulfate in a concentration of less than 12% and sulfuric acid in a concentration of less than 7%; and

stretching the resulting spun viscose solution to a length of from about 150 to 190% of the original length of the spun viscose in a stretching bath consisting essentially of sulfuric acid in a concentration of from 0.1 to 5%, sodium sulfate in a concentration of less than 10% and zinc sulfate in a concentration of less than 5% at a temperature of from 60 to 100 C.

2. The process of claim 1 wherein said viscose solution further contains polyethylene glycol in an amount of from 0.1 to 10% by weight, based upon the weight of cellose in said viscose solution.

3. The process of claim 2, wherein said polyethylene glycol has a molecular weight within the range of from about 800 to about 1700.

4. The process of claim 1 wherein the temperature of said spin 'bath composition is maintained within the range of from about 20 to about 50 C.

5. The method of claim 1 wherein said viscose solution is xanthated by about 30 to 34% by weight of carbon disulfide, based upon the weight of cellulose in said viscose solution.

6. The method of claim 1 wherein the concentration of zinc sulfate in said spin bath composition varies from 3 to 5%.

7. The method of claim 1 wherein said viscose solution contains from 1 to 5% by Weight of said zinc compound, based upon the weight of cellulose in said viscose solution.

8. The method of claim 1 wherein said viscose solution contains from 0.5 to 4% by weight of said amino compound, based upon the weight of cellulose in said viscose solution.

9. The method of claim 2 wherein said viscose solution contains from 0.3 to 3% by weight of polyethylene glycol, based upon the weight of cellulose in said viscose solution.

10. The method of claim 1 wherein said amino compound is selected from the group consisting of monomethylamine, dimethylamine, diethylamine, propylamine, cyclohexylamine, butylamine and said amino compounds having added thereto ethylene oxide.

11. The method of claim 1 wherein the viscosity of said viscose solution varies from 50 to 400 seconds.

12. The method of claim 1 wherein the speed of spinning is less than meters per minute.

13. The method of claim 1 wherein said amino compound is selected from the group consisting of monomethylamine, dimethylamine, diethylamine, propylamine, cyclohexylamine, butylamine and said amino compounds having added thereto about 3 moles of ethylene oxide.

References Cited UNITED STATES PATENTS 2,860,480 ll/1958 Cox 264-188 2,983,572 5/1961 Elling 264-194 3,340,340 9/1967 Mytum 264-188 3,364,290 l/l968 Antema et al. 264-191 3,494,996 2/1970 Stevens et a1. 264-197 2,953,425 9/1960 Heuer et al 264-194 3,539,679 11/19'70 Kimura et a1. 264-197 JAY H. WOO, Primary Examiner US. Cl. X.R.

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