JPS6050882B2 - Method for producing viscose rayon filament yarn - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention produces viscose rayon filament yarn with high uniformity and aging resistance obtained from viscose dope through a series of rapid and extremely simple processing operations. Regarding the method.

More specifically, since the free sulfur in the yarn is much lower than that of viscose rayon filament yarn produced by the conventional continuous spinning method, viscose rayon filament yarn has excellent weather resistance, light resistance, and other changes over time. Regarding the manufacturing method. Conventionally, many viscose rayon filament yarn manufacturers have produced yarn using a splitting process, and after spinning, the yarn is rolled up into a container, etc., and then the package is scoured and dried in a separate area. It is clear that this has two undesirable implications. The first is that the spun yarn package must be removed from the spinning area, transported to the scouring area, and then redeployed there; This means that the finishing process can be completed. For this reason, the industry requires many workers, and differences in the history of spinning or drying along the yarn length within the package remain as quality differences until the end, resulting in filament yarns that are uneven in the yarn length direction. I've been plagued by inadequacies.

Therefore, viscose rayon filament manufacturers have been pursuing continuous spinning methods for many years in order to obtain yarns with high uniformity and labor productivity, and as a result of these efforts, filament yarns continuously spun from viscose and Methods and apparatus for making the same have been provided. In these known methods, viscose dope is passed through a spinning nozzle and formed into a filament, and then continuously fed in the filament form to the next process, where it is impregnated, chemically treated, heat treated, and dried. , Apply finishing agent and heat as necessary. As a matter of course, the filament immediately after spinning contains a large amount of harmful substances, and therefore, a certain amount of time is required for the scouring treatment to remove these substances.

Therefore, there has been a desire for a means that can accumulate long filament parts and move them forward despite being small in size. It is also known to accumulate the data on a mobile network and perform the above-mentioned processing during movement. In the conventional splitting method, a large amount of filament is processed in a tightly aggregated form (cake or spool), which can take a long time for processing, whereas in the continuous spinning method, the scouring processing time is Even in terms of equipment costs, only a few minutes at most can be tolerated.

Great attention has thus been paid to the effective removal of harmful substances within the filament which are subjected to this extremely short processing time. One of the prior art techniques in the field is known as Nelson continuous spinning. Rayon Textile Monthly [RayOnTextiIeMO
nth28, Dec, 59 (1947)]. Here, the thread is wound around both rolls as the rolls rotate due to the inclination of the two rolls. However, during this time, acid treatment is performed to complete coagulation and regeneration, followed by water washing and drying, simplifying the scouring process without the desulfurization and bleaching required in the split method. This method reduces equipment costs and operating costs, so even small deniers! Although it is suitable for obtaining small filament yarn, the produced yarn contains a large amount of metals, sulfur, and their compounds, and especially contains a large amount of free sulfur, so its properties change over time. In other words, it has a defect in which its strength, elongation, or whiteness decreases over time when exposed to light or heat, and for actual use, desulfurization and bleaching are required separately, and it is called "unrefined yarn." These shortcomings have made the textile manufacturing industry extremely reluctant to use the yarn in some applications, leading yarn manufacturers to incur high equipment costs and divide the yarn in order to supply products acceptable to the industry. Another method of applying the method's refinement mode has been provided. Some practical methods provided to achieve this objective are known from the following publications.

In the method described in Japanese Patent No. 133871 by Mr. Walter Fredo Knebutsiyu, scouring treatments using chemicals such as water washing, neutralization, desulfurization, and bleaching are carried out using a reel with arms that alternately protrude for each chemical process. This is done while moving the thread forward using the . This technology is an industrial
It is widely known as a rayon continuous spinning method. Another method, described in Textile World Vol. 97, No. 15 (December 1947 issue), involves combining multiple rolls at a slight inclination to form a single reel, which is washed with water between each roll's rotation to feed the yarn. , carry out chemical scouring processes such as neutralization, desulfurization, and bleaching. This technique is known as Kruziyan continuous spinning method. British Patent No. 32903 (Patent No. 196) by Sidney Warren Parker
In the method described in , a chemical treatment roll is divided into a number of areas in contact with the yarn, and each chemical treatment is carried out by a machine arranged in an arc around the circumference of the treatment roll and in contact with the spiral of yarn. . Needless to say, these continuous spinning methods reproduce the scouring process of split-type viscose rayon filament yarn, so the installation area is large and handling is unavoidably complicated. Moreover, as the yarn moves from one chemical treatment area to another, the various treatment liquids mix, reducing the efficiency of the treatment process, and consideration has been given to preventing this. Furthermore, other known methods attempt to remedy these disadvantages by providing barriers, such as flanges or grooves, on the roll surface to prevent the tendency of different chemicals to mix. Although the yarn obtained in this way has reduced the content of metal components such as zinc, lead, and iron, and has high whiteness, the mechanical properties, dyeing properties, whiteness, etc. still deteriorate over time. I could never be freed from my tendency to go.

Yarns obtained by these known processes, ie, the Nelson method, the Industrial Rayon method, the Frugian method, and others, have been accepted in certain fields because of their thickness in the yarn direction and uniformity of dyeing.

However, the efforts that have been made to reach the present invention have focused only on adapting the splitting method to a continuous method or simplifying it from a cost perspective, and the continuous spinning and refining process can be completed within a few minutes at most. No consideration has been given to the chemical and physical changes that free sulfur undergoes inside the filament, and to date no filament yarn has been obtained that overcomes the above drawbacks. However, in the present invention, it has become clear that a scouring technique using only water can yield a novel yarn product having unique properties not seen by conventional methods. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for producing viscose rayon filament yarn that has the same aging resistance as filament yarn produced by the splitting method, using extremely simple means.

Another object of the present invention is to provide a method for producing a filament yarn which has the above-mentioned properties similar to those of the yarn obtained by the splitting method, but which has extremely high uniformity in the yarn length direction.
It is also an object of the present invention to obtain a yarn that has properties that are particularly useful for outer garment applications and the like outside of the fields in which viscose rayon filament yarn has been conventionally used. Another object of the present invention is to provide a method for obtaining filament yarns with a high yield and an economical content in which harmful contents are suppressed to below permissible limits under extremely orderly operation. Other objectives will become apparent from the description below. That is, the present invention provides a method for producing viscose rayon filament yarn using a continuous spinning method in which viscose is discharged from a spinning nozzle, coagulated and regenerated, and then scoured and dried.
A method for producing viscose rayon filament yarn by a continuous spinning method, which is characterized in that after coagulation and regeneration using the following viscose (based on cellulose weight), washing and drying is carried out after allowing a standing time as shown by the following formula: .

7.5DM+15≦T,≦10DM+25 (In the above formula, DM is the denier of the monofilament constituting the rayon filament yarn to be spun, and T9 is the standing time of the coagulated and regenerated viscose in seconds).

As is well known, the series of processes for producing viscose and forming it into filaments starts by reacting cellulose with an alkali to produce alkali cellulose.

After the cellulose is mercerized, it is subjected to an immersion-pressing process to dissolve and remove low-molecular substances (hemicellulose) and remove excess alkaline content. vν■VlV●Yi=Otsuv- Next, the alkali cellulose is reacted with carbon disulfide through a sulfurizing machine, a dissolving machine, or a sulfurizing machine to form water-soluble cellulose xanthate, which is then dissolved in dilute alkali to form viscose. Generate.

The viscose that has undergone sulfurization and dissolution is left at a constant temperature for a certain period of time before being fed to a spinning machine in order to further improve dispersion and ensure proper distribution of xantogen groups. During this time, the viscose composition used for mixing, filtration, and defoaming is a known composition, such as 7.8 to 8.0% cellulose and 5.0% caustic soda.
An aqueous solution of 0 to 6.5% (based on the weight of viscose) can be used. The viscose, which has thus had sufficient properties to be fed to the spinning section by aging, is regenerated through the spinning nozzle into a sulfuric acid solution to obtain cellulose filaments. A known composition can be used for the spinning bath composition.
If only the main reaction of cellulose is carried out completely, the problem of inclusions will not occur at all, and the sulfur introduced into viscose in the form of CS2 will eventually become gaseous CS2, metal sulfides, and metals. Becomes sulfate.

However, other small amounts of sulfur become free sulfur and are also released as hydrogen sulfide. Thus, in the known splitting system, after being wound up during the spinning process, the raw silk is fed to another area for scouring and finishing treatment to remove free sulfur, metal sulfides, and metal sulfates contained in the spun raw silk. was normal.

Here, first, the deposits and water-soluble substances of the produced filament are removed by washing with water, and then, in order to remove the fine sulfur particles contained inside the yarn, the yarn is treated with a sodium sulfide solution to be eluted as polysulfides. Furthermore, it is washed with water and treated with sodium hypochlorite (NaOC) to remove metal sulfides and metal sulfates, which are then washed with water, followed by pickling, neutralization, and washing with water.At this time, they remain in the yarn. Free sulfur is 0.02
It is known that the obtained yarn has excellent resistance to change over time. In the course of these series of treatment operations, cellulose and sulfur undergo several side reactions in addition to the above-mentioned main reaction.

Several other minor products are generated and remain in the yarn by these reactions. Even if metal sulfides or metal sulfates are contained in the yarn during the production process, they can be removed relatively easily and are stable substances, so they will eventually be contained in a certain amount in the yarn. can be recognized. on the other hand,
It is well known that the sulfur content in filament yarn makes processing difficult during subsequent use of the yarn, but in the method of the present invention, free sulfur content and its content are particularly reduced among sulfur-containing substances. Focus on.

This free sulfur content remaining in the produced filament is an extremely unstable substance that deteriorates the microstructure of the fiber as it changes over time during storage and use of the yarn, and as it transforms into other compounds. let Therefore, together with the sulfuric acid content and caustic soda content described below, it becomes a harmful component that deteriorates the properties of the yarn. Free sulfur, which is a particularly unstable substance,
Even if you try to remove it by continuous spinning, it is almost difficult to remove, and all known continuous spinning filament yarns have a content of 0.1%.
It contained a high degree of free sulfur content.

These matters are described, for example, in publications by PNSH of the Soviet Union (PNSH), the name of a continuous spinning machine in the Soviet Union. For this reason, it was believed that it was practically impossible to attempt to effectively remove free sulfur in continuous spinning processes. However, in the present invention, by using viscose in which sulfur oxides are limited within a certain range, and by providing a certain limited amount of storage for the filament during the regeneration process after forming it into a filament, it is possible to completely A practical method has been found to accomplish highly valuable chemical transformations of harmful contents in filaments that would otherwise have been impossible.

An explanation of changes in sulfur during the viscose production process, aging process, and ripening process will be helpful in understanding the present invention.

In addition to the bulb, caustic soda and carbon disulfide are added to produce viscose, but these are added in somewhat excess to the bulb. This excess carbon disulfide, caustic soda and oxygen serve as starting materials for the sulfur side reaction.
Excess carbon disulfide and caustic soda produce trithiocarbonate. The generated trithiocarbonate reacts with oxygen during the sulfurization process to generate various sulfur oxides such as sodium sulfite, thiosulfate, sodium sulfate, and sodium sulfide.

. o The thiosulfate S2O3 produced is the first substance that later generates free sulfur.

On the other hand, cellulose xanthate reacts with oxygen during the ripening process to produce cellulose xanthate dimers. The produced dimer reacts with the sodium sulfide produced in the reaction of formula (5) to produce polyphide.

This becomes the second material from which free sulfur is produced. In addition, some of the polysulfide reacts with excess carbon disulfide to form perthiocarbonate.

In this way, during the period from sulfurization to ripening, carbon disulfide, caustic soda, and oxygen react with each other to form sulfur oxides S in viscose.
. Increase x. Therefore, in order to suppress this, it is necessary to remove excess sulfur disulfide and to ensure vacuum conditions in the sulfurization zone in the latter stage of the sulfurization reaction, which is necessary to prevent oxygen from entering. In order to achieve the present invention, the content of sulfur oxide (SOx) in the viscose supplied for spinning should be 0.55% by weight or less, preferably 0.55% by weight or less based on the weight of cellulose.
It is necessary to keep the saliva amount below 5%.

Sulfur oxides (polysulfide Sx, thiosulfate S2O3) in viscose can be accurately determined by the method described below. In sampling immediately after sulfurization and dissolution, the amounts of S2O3 and SX vary greatly depending on the sulfurization and dissolution conditions, particularly the vacuum conditions and the amount of oxygen mixed in, and are approximately 0.7% by weight (based on the weight of cellulose) depending on the vacuum conditions.

However, the xanthate diurization reaction and trithiocarbonate oxidation reaction proceed during the aging process, which lasts from several hours to more than ten hours before being supplied to the spinning process, so the sulfur oxide content SOx of the viscose supplied to the spinning machine progresses. is 0.7~0.
% of heel weight (based on cellulose weight) or even more. However, in the present invention, the amount of sulfur oxide must be 0.55% by weight or less (based on the weight of cellulose), so it is necessary to appropriately select conditions in which the amount immediately after sulfurization and dissolution is less than this. Thus, sulfur oxides and their derivatives, perthiocarbonates, react with sulfur during the spinning process, ultimately converting into gaseous sulfur dioxide, hydrogen sulfide, and water-soluble sodium sulfate, as well as converting elemental sulfur. generate.

Further, gaseous sulfur compounds and water-soluble sulfides combine with metal ions that have entered the filament from the spinning bath acid to newly generate metal sulfides and metal sulfates. However, in the polysulfide general formula, the generated sulfur becomes free sulfur and is dispersed and contained in the filament in the form of a colloid.

In the present invention, the removal of free sulfur is the mass transfer of this colloidal sulfur out of the filament. Physical removal by deswelling of the filament is much faster than removal by any chemical change or dissolution, when this must be accomplished by a process of no more than a few minutes. Therefore, the manner in which free sulfur is reduced varies considerably depending on the deswelling of the produced filament, and this can be understood by examining changes in the fine structure of the yarn during the production process. In other words, by tracking changes in the degree of swelling of the filament, it is possible to understand the process by which free sulfur moves in the filament, condenses, and is eliminated. The degree of swelling of filament yarns is given by the following method.

250 mL of buffer solution (PH=6.5) in a 500 mL beaker
) and add 1-2 pieces of ice.

While stirring the liquid using a glass rod, sample 1 q of thread using an air sucker type sampling device. After immersing for 8 minutes, pick up the thread with a glass rod, place it in another 500 ml beaker, add 200 ml of cooling water, and leave to immerse for 5 minutes.

Transfer the thread to another 500mL beaker and make 250ml of 19/e
Add 1 sodium dodecylbenzenesulfonic acid solution and soak for 5 minutes. The thread is transferred to a centiur tube and dehydrated by centrifugation. Weigh the dehydration system (WC), 10
After drying at 5°C for 2 hours, weigh again (Wb). The degree of swelling (D.S.) of the yarn is given by the ratio of Wc and Wb.
The swelling degree of the yarn measured in this way shows a value of 5 to 8 immediately after spinning.

Then, while the thread is left with the attached acid for a certain period of time, the degree of swelling rapidly decreases, and the diameter of the filament also decreases.
In order to achieve the present invention, it is necessary to proceed with the de-swelling process until the degree of swelling becomes 3.5 to 3.3 (causing some errors in measurement). The decrease in the degree of swelling (DS) of the filament yarn produced is related to the composition of viscose, but if it is within the normal composition range, it is related to the single filament denier (DM) of the filament yarn.

As is well known, the coagulation, regeneration, and scouring processes involve chemical changes and mass transfer. Therefore, it is thought that the problem of moving speed and final quantity is related to the denier of the single yarn and the processing time, and as the single yarn denier decreases, the moving speed increases and the amount of residue in the yarn tends to decrease. have. However, as a result of many experiments, it has been found that after coagulation and regeneration of viscose, the standing time Ts (seconds) required to allow deswelling to proceed until deswelling is inhibited by water must be determined. , the quantity is preferable.

The upper limit of the standing time is determined by the fact that, for example, when the filament yarn to be processed has a small denier, crystals of sodium sulfate may form on the filament yarn or on the roll or reel where the yarn runs, hindering the progress of the yarn. Although it is necessary to deal with such problems, it means the time value at which it no longer contributes to the effect of removing contained substances.

One of the meanings of the upper limit of the standing time is that the acid penetrates into the filament. The resulting change of sulfur oxides into free sulfur and the removal action by deswelling, a series of effects, are saturated at the upper limit time. Moreover, leaving it for longer than necessary increases residual acid in the final yarn. By setting the standing time within this range, the amount of free sulfur in the dehydration process can be reduced to an acceptable level that will not cause problems in subsequent use. Therefore, it seems that the effect of standing time is not a problem of water solubilization of the sulfur compound, but is due to the physical process of deswelling. In the present invention, it is important to "leave" the yarn for the limited period of time mentioned above.

This is because known physical desulfurization methods emphasize actively supplying regeneration liquid to the yarn in order to simultaneously regenerate and desulfurize the filament immediately after spinning. This is because it has been proposed to dissolve it in a bath (Mr. E.M. Moilevsky, All-Soviet Institute of Chemical Fibers), or to supply the Itokawa regenerating liquid through a spray or nozzle. The free sulfur in the yarn produced will be verified by the method described below.

The free sulfur content of the yarn obtained according to the present invention is usually 0.
．． 02-0.04%.

This value is extremely small compared to yarns produced by conventional continuous spinning methods. According to the method of the present invention, it is possible to achieve a value close to 0.02%, as can be seen from the measured values in Examples described later. If the standing time is not achieved, free sulfur clearly remains above 0.04%. Many of the prior art techniques that apply continuous scouring methods that take a long treatment time using soda sulfide and bleaching, which were adopted in the split method, have not produced any effects due to the extremely short treatment time, but rather have no effect on desulfurization or bleaching. Due to the reduction in processing time replaced by the space devoted to bleaching, the deswelling of the yarn is rather inhibited and the cleaning action of the inclusions is reduced. After the viscose thus coagulated and regenerated has been allowed to stand for a time Ts seconds, the filament is reduced in free sulfur content to less than 0.04% and subjected to washing with water.

The water washing treatment time Tw is preferably 0.5 TS seconds or more. However, at this time, it is difficult to remove free sulfur, and only a small amount of free sulfur adhering to the surface is removed by water, and the actual reduction has stopped, so other sulfur compounds or water-soluble salts only are removed here.

Of course, the large amount of washing water and the long washing time do not have any unfavorable effects on the yarn, if cost is not considered. However, in the practical industrial means provided by the present invention, there is no such need, and surprisingly, by setting the standing time to the above-mentioned Ts, the time can be as short as 0.5 TS seconds. Most of the contained substances can be removed even during the water washing period. This means that substances that can be removed by washing with water can be removed with extremely short washing times, but other substances, such as free sulfur and metal sulfides or metal sulfur salts that are sparingly soluble in water, can be removed with long washing times. This shows that it cannot even be removed. In this way, the residual alkaline content or residual acid content of the yarn obtained by the present invention is only 0.04% or less, which is about the same level as the effect of the finishing oil added to the yarn at the finishing stage, so it is no longer suitable for actual use. can be reduced to a level that does not cause problems. As a guideline for knowing the degree of regeneration of threads that have been washed with water, and because it is necessary to know the degree of washing, it is necessary to know the residual alkali content or residual acid content of the threads.

This analysis can be determined by simple neutralization titration described below. It may also be necessary to understand changes in other ingredients, especially metal ingredients.

Lead and zinc are naturally not present in viscose as metal components, and they first enter the viscose during the filament production process from the coagulation bath during the filament forming process. Sulfur and its active compounds forming in the filament can easily react with metal ions. These ions will therefore immediately convert to sulfide or sulfate. Some ions of zinc react with hydrogen sulfide to form zinc sulfide, but it gradually returns to the form of zinc sulfate again within the time it is left in contact with the acid. Therefore, it is easily removed by washing with water. Since there is a positive correlation between the total sulfur content in the yarn measured by the sodium zincate method and the zinc content, zinc combines with the majority of the total sulfur content and is somehow involved as zinc sulfide. it is conceivable that. Thus, some of the zinc remaining in the filament in the form of ZnS is not removed by washing with water, but this substance is non-toxic, non-colored, and is a stable compound that does not contribute to the aging of the yarn. It takes shape. A small amount of lead is probably dissolved in the coagulation bath as lead sulfate, which is converted to lead sulfide by the hydrogen sulfide and remains in the yarn. However, this amount is small and can be eliminated by using a coagulation solution that does not contain lead. This substance is the sole cause of coloration of the yarn, but is an extremely stable compound and does not contribute to changes in the molecular structure of the yarn. In any case, if the standing time and washing time after coagulation and regeneration shown in the present invention are achieved, these metal-containing substances will be removed to the minimum and will not affect the weather resistance of the yarn. While most of the prior art uses hot water for washing, in the present invention, a sufficiently high washing effect can be achieved with water at room temperature. This is thought to be related to the above-mentioned standing treatment, but in the method of the present invention, almost no change in the residue is observed even when the temperature is increased. Therefore, not only is it very advantageous in terms of energy, but also very high quality stability can be ensured without the need to use water at a controlled temperature. The above point is one of the important progressive points of the present invention, and this was confirmed by Mr. G.G. Finger of the All-Soviet Institute of Chemical Fibers and E.M.
This will become clear if we refer to what Mr. Moleifsky said.

Previously known prior art mentions the importance of sulfur sublimation when treating filaments with aqueous solutions at high temperatures, since free sulfur diffuses from the depths of the filament to the surface in the form of particles; has a temperature of 75
This is because it was necessary to use hot water at ~85°C. It should be noted that in the method of the present invention, the desulfurization of free sulfur is not carried out using hot water, but rather during the "standing time" before the water comes into contact with the thread. The content of calcium and magnesium carbonates in the washing water, so-called hardness, is not particularly limited, but it is preferable to use 1 to 20 ppm.Water with particularly high hardness should be used after ion exchange.Also, silica It is appropriate to use a pH of several Ppm to several tens of Ppm.Of course, it is better for pH to be close to 7, but it is fine as long as it is within the range of 6.5 to 7.5.Thus, the water washing is completed. Afterwards, the filament is dried and subjected to a final dewatering process, leaving only a small amount of residue in the yarn.

All known means for continuous production of viscose rayon filament yarn can be used to carry out the present invention.

One embodiment is shown in FIG. In the example shown in FIG. 1, 1 is a viscose strainer and a viscose guide pipe;
2 is a spinning nozzle, 3 is a coagulation bath, and 4 is a guide. The generated threads are first accumulated while moving forward for a standing time Ts seconds on the main roll 5 and separation roll 6, which are arranged to advance in a spiral manner at regular intervals, and then on the washing water supply means 8, 8.
After that, the yarn is dried by the drying section 9 on the roll, and when the drying is completed, it leaves the roll, passes through the guide 10, and is sent to the winding machine 11 as a yarn package. If necessary, a finishing oil is applied before winding, and the yarn is twisted through heating means.There may be more than one separating roll; If the rolls are mounted at different distances from the main roll, it is necessary to limit the number of yarns processed so that the difference in length of the yarns processed does not make the quality of the product uneven. .
The means for carrying out the invention is not limited to the method of FIG. 1, but other known thread advancement means for guiding the thread in a straight line may be used. The value of the yarn obtained according to the invention will become clearer by testing it by the method described below to determine the whiteness of the yarn and its resistance to changes over time.

The whiteness of the filament yarn produced is defined as the ratio of the whiteness of the sample to the whiteness of a certain standard white board (magnesium oxide).

The thread is wound around a plate, and the reflectance of the sample is determined by setting the reflection of the standard white plate of the spectrophotometer as 100%, and the reflectance is expressed as whiteness. In this method, the whiteness of the yarn obtained in the present invention is 65 or more, whereas the whiteness of the yarn obtained in the prior art is 40-55. On the other hand, the contents of the present invention, especially the free sulfur content, are much lower than that of the yarn obtained by the conventional continuous spinning method, and are slightly higher than that of the yarn obtained by the splitting method. Yarn products have unique properties in terms of weather resistance. The deterioration of the properties of the yarn due to long-term standing is revealed by examining changes in mechanical properties and coloring (yellowing degree) after processing with a fade meter or weather meter for a certain period of time. For example, if the degree of yellowing after processing for 6 (b) with a fade meter is judged based on the gray scale, the yarn according to the prior art is 3
In contrast, the yarn obtained by the present invention exhibits discoloration of grade 6, which is equivalent to that of the yarn obtained by the splitting method, and shows remarkable resistance to changes due to light. It turns out that it has. Furthermore, when irradiated with a fade meter for 18 hours, the strength of conventional continuously spun filament yarn is 20~
Whereas a reduction of 30% or more is observed, the yarn of the present invention shows a reduction of less than 10%, usually less than 5%. Method for measuring sulfur oxides (polysulfide Sx, thiosulfate S2O3) in viscose
Add about 35y of boric acid to 00ml of water and dissolve, boil for 5 minutes to remove dissolved air, leave the solution hot and add 5TnL of 10% KCN.

While stirring this solution with a magnetic stirrer,
5y of viscose was added, and a first empty Erlenmeyer flask and 10% NaOCl aqueous solution were added. Connect the second Erlenmeyer flask and hydrogen sulfide gas will no longer be generated ↑ 30 ~
4. Boil the powder and stir. For analysis of polysulfide Sx, the solution after the preliminary reaction is acidified with 5 ml of concentrated hydrochloric acid, bromine water is added with stirring until the yellow color remains forever, and this is left in a dark place.

Add 3-5 ml of 3% phenol to this. Leave to stand for 1 minute to remove excess bromine, add about 10g of potassium iodide, leave to stand for 1 minute, use starch as an indicator and use 0.01
Titrate with N sodium thiosulfate.

For analysis of thiosulfate S2O3, add 25ml of buffer to the solution after the above preliminary reaction. pH=4.6 with acetic acid
Add an excess of 0.01N iodine solution, and back titrate with 0.01N sodium thiosulfate using starch as an indicator. Here a...0.01NNa2
s203 Titration amount (ml) f...0.01N
〃Factor g...Amount of viscose collected (g
) Here b...0.01NI? Addition amount (ml)
F, 2... Factor c...
0.01NNa2s203 addition amount (Mt) FNa2
S2O3...〃Factor g...Amount of viscose collected (g) Analysis method for free sulfur in yarn 500
Put 200ml of water, 20g of boric acid, and 10y of thread into a ml gas generator, boil for 1 hour while passing nitrogen gas, and after cooling, use phenolphthalein as an indicator. Neutralize with a solution of caustic soda.

Next, add 20ml of 200y/e sodium sulfite and 1f
Add 5 ml of /e stearic acid soap, boil for 3 hours while passing nitrogen gas, and after cooling, transfer the liquid to another 500 mt beaker. Wash the thread with 100 ml of water and add 10 ml of 40% formalin and 20 ml of acetic acid, sodium acetate buffer.

Next, add concentrated acetic acid until pH=4.6, add a certain amount of 0.1N iodine water, and back titrate the starch with 0.1N sodium thiosulfate as an indicator. The above process is performed in the same way without inserting yarn as a blank. A...0
．． 1N-Na2S2O3 titration (Tfll) blank B
... Sample y...
...Amount of thread collected (absolutely dry) y How to analyze residual alkaline content and residual acid content of thread Collect sample 5y in a 200ml beaker, add hot water, cover with a watch glass, and place on a water bath.

After heating about 6 powders, cool. Add promthymol blue reagent to this and titrate with N/100 caustic soda or N/100 sulfuric acid (Acc). Carry out a dry test by operating in the same manner (Bcc) The examples described below are for convenience of explanation and are not intended to limit the present invention.

In the examples below, ordinary viscose filament yarns are described, but these can also be replaced by flat or other irregularly shaped filaments. Similarly, the denier, temperature, spinning speed, and other conditions may vary widely without departing from the spirit of the invention. Example 1 The viscose composition immediately before spinning was a cellulose concentration (relative to viscose) of 8.25% and a polysulfide content of 0.14.
% (based on cellulose), thiosulfate content 0.33% (
Using viscose (vs. cellulose), 0.88 m1φ
No. 40: Fl. A 120 denier yarn consisting of 40 filaments was spun at a spinning speed of 104 m/min using the apparatus shown in FIG.

The swelling degree of a sample of the first portion of the yarn that was hung on the roll after spinning was measured and found to be 71.

The length of time the yarn was left on the roll was changed, and the washing time after being left was set to 27 seconds.The yarn was washed with water with a hardness of 10 and pH=6.5 at a rate of 300 cc/min, and then dried. The resulting yarn was sampled and the substances contained in the resulting yarn were analyzed. The results are shown in Table 1. The degree of swelling was measured by sampling after the end of the standing time under each condition and before washing with water. Furthermore, among the yarns thus obtained, those whose standing time was 4 to 2 or less had a whiteness of 55 to 60, while those whose standing time was 4 to 2 or less had a whiteness of 65 to 66.

Example 2 Using the same viscose composition as used in Example 1, a 120 denier yarn consisting of 26 filaments was spun by the apparatus shown in FIG. 1 through a spinning nozzle with a 2eyfL of 0.08 Tf$tφ. Speed 128m/
Spun in minutes.

After spinning, the first yarn put on the roll was sampled and the degree of swelling was measured, and the result was 5.4.

The length of time the thread was left on the roll was changed, and the washing time after being left was set to three times.The thread was washed with water of hardness 10 and pH=6.5 at a rate of 300 cc/min. The dried yarn was sampled and the content of the resulting yarn was analyzed. The results are shown in Table 2. The degree of swelling was analyzed by sampling after the end of the standing time under each condition and before washing with water. As can be seen from Examples 1 and 2, as the filament denier constituting the filament yarn to be treated increases, the deswelling effect that occurs during the standing time changes and the amount of sulfur is increased to remove free sulfur. It turns out that it takes a lot of time.

It can be seen that the lower limit of the processing time when the single yarn denier is 3 denier is 37 to 39 seconds, and when the single yarn denier is 4.6 denier, it is about 50 to 51 seconds. On the other hand, it has been found that the effect of removing inclusions when left for a very long time is saturated and becomes constant, and it is understood that such conditions only increase the bulk of the device and do not contribute to removal of inclusions.

Therefore, when considering the effect of removing the contained substances and the cost involved, the effectiveness of the standing time shown in the present invention becomes clear. Furthermore, 50 consisting of 20 filaments
denier yarn and a 75 denier yarn consisting of 19 filaments were similarly tried, but with a free sulfur content of 0.04
% or less, the lower limit critical time of the standing time and the removal effect saturation time were as shown in Table 3.

Example 3 Using the methods of Examples 1 and 2, yarns were obtained in which the standing time was set to 5 times 2 and 5 times 2 times, respectively, and the washing time was varied.

Table 4 shows the analysis results of substances contained in the yarn. The washing water used was the same as in the above example, and the amount used was 300c under each condition.
It was adjusted so that it was c/min. As can be seen from the results of the above experiments, water-soluble substances can be sufficiently removed if the washing time is at least half of the standing time, and any longer time will not contribute to the removal of contained substances. Example 4 This is viscose obtained by mixing some air during sulfurization and dissolution, and the composition immediately before spinning has a cellulose concentration (relative to viscose) of 7.85% and a polysulfide content of 0.

19% (based on cellulose), 0 thiosulfate content.

0.0 using 45% (based on cellulose) composition (A)
A 120 denier yarn consisting of 26 filaments was spun at a spinning speed of 118 m/min using the apparatus shown in FIG. 1 through a spinning nozzle having 26 holes of 95 Tr$Lφ.

After spinning, the first yarn put on the roll was sampled and the degree of swelling was measured, and the result was 7.4. On the other hand, the cellulose concentration obtained by completely cutting off the inclusion of air during sulfurization and dissolution was 7.8.
Composition (B) containing 6% polysulfide, 0.14% polysulfide, and 0.30% thiosulfate was spun under the same conditions.

The degree of swelling of the yarn immediately after spinning was 7.4.

Spinning from the above two viscose compositions, leaving time,
The washing time was varied, and the threads were washed at a washing rate of 300 cc/min with water having a hardness of 5 and a pH of 6.5, and then the dried threads were sampled and the substances contained in the obtained threads were analyzed.

The results are shown in Table 5. From the above results and a test to determine the permissible critical value of the sulfur oxide content in viscose, if the sulfur oxide content (SX+S2O3) in viscose is 0.55% or more, it will remain free even if left standing for a long time during the spinning process. Sulfur was found to be difficult to remove. Example 5 Using the viscose composition (B) in Example 4, 4C)11. A 120 denier 40 filament yarn was spun at a spinning speed of 130,111/min using a spinning nozzle and subjected to scouring and drying treatment.

The chemicals used to treat the yarn and the treatment time were as follows. Leaving treatment: 3 [shares] Washing treatment: 1 bottle 600cc/min Bleaching treatment: 1 bottle 2 PH91.

28y/'30°C 1500cc/min Water washing treatment: 1 minute 260cc/min Neutralization treatment: 15 seconds NaHCO3l. Oy/E2O'Cl
OOOcc/min Water washing treatment: 3 [Co., Ltd.] 1000 cc/min The content of the yarn obtained was as follows.

*Based on the sodium zincate method. ※※ Indicates residual acid.

In addition, in this method, 128y/'
When a solution of 260 y/e of sulfuric acid, 260 y/e of sodium sulfate, and 15 y/e of zinc sulfate (50°C) was treated at a flow rate of 2000 cc/min to accelerate regeneration, free sulfur was 0.

0.41%, but the effect is not as great as in the case of the long standing time in Example 1, and considering the cost required, it can be seen that this is not an advantageous method.

Example 6 Using the threads obtained in Examples 1 to 6 (Nos. 1 to 7) and the threads obtained under other conditions (Nos. 8 to 10), fading was performed to examine their light fastness. Discoloration after exposure for (1) hour was determined on a gray scale using a meter.

The results are shown in Table 6. As can be seen from these results, the light fastness is largely controlled by the amount of free sulfur contained in the yarn, and it can be seen that if the amount of free sulfur is 0.04% or more, only poor results can be obtained.

Although the mechanism of action is not clear, it is clear that free sulfur is extremely unstable and is the substance that causes the yarn to change over time. This confirms that the process of the invention, which is highly effective in removing free sulfur, is a means of obtaining valuable yarn. Example 77 Using yarn whose light fastness was classified as 2nd to 6th grade according to Example 6, the color fastness was 18 with a fade meter.
Changes in the tensile properties of filament yarns were investigated by irradiation.

The results are shown in Table 7. The thread numbers are the same as those in Example 6, and all threads are 120 denier 2.
It can be seen that for all tensile properties, the retention rate decreases as the light fastness decreases, and those of grade 4 or lower cannot withstand actual use.

In addition to the results shown in the examples above, the yarn obtained by the present invention exhibits excellent retention of mechanical properties even when exposed to high temperature conditions, and also has extremely high retention of whiteness. .

The yarn produced by the present invention has high resistance to changes over time under any of these environments, so it is extremely easy to handle as there is no substantial change during transportation or storage until the yarn is used as a woven or knitted fabric. It is easy to use, and does not change due to environmental conditions such as sunlight, moisture, or oxygen even after being made into a woven or knitted fabric, so it can be used not only in fields where conventional viscose rayon filament yarn is used. , making it possible to use outer clothing in areas where its use was previously restricted.

Therefore, the continuous filament yarn from viscose provided by the present invention is suitable for outer garment fabrics such as chifuon, huaiko, ottoman, palis, dechine, georgette, satin, moroken, bengalin etc. Patske. The high uniformity of the yarn over the entire yarn length within the web also makes it possible to apply it to textile fields, such as flat knitting, warp knitting, and circular knitting. The viscose rayon filament yarn according to the present invention can be mixed with filament yarn made of synthetic fiber! It is also possible to provide a blended material with characteristics as an outer garment, especially when mixed with continuous filament yarns of polyethylene terephthalate, which have a high degree of uniformity.

This is because in these combinations, the defects of each constituent material are interpolated (not only do they achieve the effect, but they also provide a cool feeling, a brilliant luster, and a smooth and smooth feel that cannot be obtained with the spun spinning method due to the fact that they are filament yarns). This is because yarns made using the conventional split method are too small for these applications, and their use has been rejected because of the quality difference between the inside and outside of a single package.
This is because the denier differs by at least 2 to 3 deniers, and the dye difference is 2 to 3 N. B. S(NatiOnal
This is because they exceeded the standards (BeurOfStandard), and if they were not used for these purposes, a significant portion of the product would have been ruined. On the other hand, known continuous filament yarns made from viscose, although these non-uniformities have been resolved, are susceptible to fading and cannot withstand use in these applications.

In the present invention, these drawbacks have been completely eliminated, so that the original characteristics of viscose can be maximized, and color development, drapability, and appropriate hygroscopicity can be utilized. The method of the invention can also provide a very inexpensive production facility for producing continuously spun viscose filament yarns.

Similarly, operating costs are lower than those of known production methods, making it possible to reduce operating costs by about 30% compared to continuous spinning using chemical solutions. Also, by simplifying the mechanism, operational and maintenance problems are eased, and the reliability of the equipment is improved. Of course, the production means of the present invention has significantly higher labor productivity than the division method, and can reduce labor productivity by about 50 to 60%.

[Brief explanation of the drawing]

FIG. 1 illustrates one embodiment of a method of carrying out the invention. FIG. 2 is a diagram showing the relationship between the denier of the monofilament constituting the filament yarn treated by the method of the present invention and the standing treatment time. 1...Viscose strainer and guide tube, 2...Spinning nozzle, 3...
... Coagulation bath, 4 ... Guide, 5 ... Main roll, 6 ... Separation roll, 7 ... Treated filament yarn, 8,8''. ...Washing water supply means, 9...Drying section on the roll, 10...
・Guidance, 11... Winding machine.

Claims (1)

[Claims] 1. A method for producing viscose rayon filament yarn using a continuous spinning method in which viscose is discharged from a spinning nozzle, coagulated and regenerated, and then scoured and dried, wherein the sulfur oxide content is 0.
．． Production of viscose rayon filament yarn by a continuous spinning method characterized in that after coagulation and regeneration using viscose of 55% by weight or less (based on cellulose weight), washing and drying is performed after allowing a standing time as shown by the following formula. Method. 7.5D_M+15≦T_s≦10D_M+25 (in the above formula, D_M is the length of the monofilament constituting the rayon filament yarn to be spun, and T_s is the standing time of the coagulated and regenerated viscose in seconds). 2 After the viscose that has been solidified and regenerated is left for a time of T_s seconds, when washing it with water, the washing time is 0.5T_s.
2. The method for producing a viscose rayon filament yarn according to claim 1, wherein the manufacturing time is at least seconds.