JPS58151217A - Fiber and film obtained from cellulose dope - Google Patents

Abstract

PURPOSE:To provide fiber and film capable of being obtained in pollution-free and industrial economical condition, by keeping a temperature of the mixtures having a specified concentration of aqueous solution of zinc-chloride and cellulose within a fixed range of temperature and by spinning from dope composed of the dissolution of cellulose by adding a specified amount of water thereto. CONSTITUTION:The mixtures of aqueous solution containing 67wt% zinc-chloride and of cellulose are kept at a temperature of 80-105 deg.C, and the cellulose is dissolved by dropping thereto a quantity of water enough to keep a concentration of aqueous solution of zinc-chloride at not less than 50wt% and by mixing. The dope, with optical anisotropy composed 5-20wt% the obtained cellulose and the aqueous solution of 95-80wt% zinc-chloride is spinned by wet spinning or air-spilting out wet spinning. Thus, the aimed fiber and film may be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to fibers and films for cellulose dope 1. More specifically, the present invention describes a novel method for dissolving cellulose, the resulting dope, and a fiber or film KM produced by spinning the O-dope.

It is well known that fibers and films used in the fields of clothing, medicine, and industrial materials are manufactured from dope obtained by dissolving cellulose. The Ning method is a typical example. However, these methods have problems, such as the chemicals used are extremely harmful to the human body, and special treatment is required to dispose of the waste, which causes pollution. There are great concerns about the future.

On the other hand, cellulose is a naturally occurring abundant resource.
Unlike petrochemical products, which are expected to have difficulty in supplying raw materials in the future, their usefulness is expected to increase in the future.

Therefore, there is a current need for the establishment of a new method for producing cellulose fibers and films that is non-polluting and industrially suitable to replace the viscose method and the cuprammonium chloride method.

When using cellulose to produce fibers and films, it is necessary to dissolve cellulose to create a solution suitable for spinning. In addition to the viscose method and the copper ammonia method currently used industrially, there are seven methods that have long been known as methods for dissolving cellulose, including hot extraction of salts. However, hot solutions of these salts have not been adopted industrially due to reasons such as hydrolysis of cellulose and inability to dissolve cellulose at a high temperature of #1 where good properties are exhibited. It has not been.

The inventors of the present invention realized that these salts could be used in the upper W by taking advantage of their superiority of being non-toxic and inexpensive, and as a result of repeated consideration, they developed the present invention. I was able to complete it.

In other words, this is the gist of the present invention.

■ It is a Dogue composed of cellulose weighing z ~ weight and an aqueous solution of zinc chloride weighing 9140 weight.

and a cell p-stove in which the zinc chloride in the zinc chloride aqueous solution is at least the weight of the trout. 4111 A method for manufacturing a 1-woman roux stove that involves dropping an amount of O* that is necessary to maintain the zinc chloride aqueous solution at 111 degrees above the isS weight. The dope is composed of 30 to 1 weight of cellulose and 1 weight of zinc chloride aqueous solution.

and the zinc chloride in the zinc chloride aqueous solution is at least SO
The purpose of the present invention is to provide a cellulose dope that is suitable for molding and is economically superior to 1%, and its production method and dope. K provides fibers or films made using the above.

Although zinc chloride solutions of cellulose and their dissolution methods are known, cellulose solutions containing cellulose with a relatively high degree of polymerization in an amount of S weight or more are not known. Also, regarding the dissolution method, since an aqueous solution containing a zinc chloride concentration of 60% by weight or more is dissolved while being maintained at 110°C or higher, cellulose depolymerization occurs and the solution becomes brownish. It is not suitable as a molding dope because it is undissolved (lulose remains, etc.).

The amount of cellulose that is normally dissolved is as low as 1 to 5 iit-, and the economic efficiency of forming flats is also quite low. The inventors studied the above-mentioned idea and the drawbacks of the above-mentioned conventional technology, and
There is no undissolved cellulose and only 5 weight of cellulose can be added.
The present invention has been achieved by discovering a method for producing a colorless and transparent dope suitable for molding.

Therefore, the present invention is capable of maintaining the concentration of zinc chloride in an aqueous solution of zinc chloride at a temperature of at least 90% by weight while maintaining the mixture consisting of a zinc chloride aqueous solution and cellulose at a temperature of at least 100°C. Must! It is characterized by dissolving the base by dropping a sufficient amount of water.

Also known as a salt that dissolves cellulose, oicH
lzmct, O et al., LiI, LiCN3,
Cm(CN8)s.

There is Hg (CN8)s KCN8 IIi. Although it is possible to dope cellulose with the method of the present invention by using the method of the present invention, it is also possible to dope the aqueous solution of these salts.
ZmCA is the most suitable O for dissolving cellulose and providing a suitable solution for spinning.
@Aqueous solution. Preferably, the ZN pseudowater solubility used in the first stage of cellulose dissolution is at least 67 kg by weight. If a ZC4 aqueous solution with a lower concentration than this is used, dissolution with cellulose by subsequent addition of water will be insufficient, and a large amount of undissolved matter will remain), and the resulting solution will lack stringiness suitable for molding, and It is extremely difficult to pass through the material O, so spinning 1
Not common. Furthermore, the concentration range suitable for use is 1 to 5 ~
15 weight.

Next, the prepared nine ZnCj, aqueous solution F cell p-su is introduced. As the cellulose, natural cellulose in the form of cotton or pulp is preferably used, but regenerated cellulose or the like may also be used, and is not particularly limited. 6 pieces weight - Zn
(The weight fraction of nocellulose in the solution for spinning, which is finally obtained by adding water to a mixture of IJI aqueous solution and cellulose, is 5 to 20.

If fIMi is lower than this, it can be easily adjusted, but it is unsuitable as a dope for spinning because it lacks the spinnability and coagulation ability necessary for spinning. In addition, at high concentrations, there is a large amount of undissolved cellulose and it is considered unsuitable for spinning. Z
In some cases, centrifugal force is used to uniformly permeate cellulose with nC4 aqueous solution, and in other cases, cellulose is immersed in a large amount of OZi+C4 aqueous solution and squeezed to a suitable concentration. The proportion of cellulose in the solution is determined by the average polymerization gK of the cellulose used, and generally those with a high degree of polymerization are used at a low concentration. When using cellulose having a number average degree of polymerization of 60% or more, flow birefringence appears in a solution containing cellulose of 5% by weight or more. This flow birefringence is measured under crossed nicols of a polarizing microscope, #Ic on the slide glass.
It can be easily detected by placing a solution, placing a cover glass on top of it, and pressing the cover glass lightly to apply shear stress. The fibers obtained from the solution of the present invention are larger in which ζOROR side folds appear in volume 1c.
The fibers are oriented without grinding, and fibers with suitable physical properties can be obtained. It is also a feature of the present invention that flow birefringence occurs at a low concentration such as ζO], and this is because the average polymerization It is expected that in the case of a material with a high degree of power, the anisotropy is also large, and the tn flow birefringence is likely to occur.

The present invention relates to cellulose dissolution.
The OZnC4 aqueous solution and O compound are maintained at a temperature of $0 to 1.5 DEG C., and then water is added dropwise. The holding temperature ta is preferably -・~1O・
'C4Il[range is used. this) low iif
However, it is difficult to dissolve cellulose.

If it is high, cellulose decomposition-deterioration occurs.

1 again. The holding time at this temperature of 1° C. usually ranges from several minutes to a fraction of the time. If the holding time is extended, there is a risk that the decomposition and deterioration of cellulose will be accelerated. While this temperature is maintained, the form of luulose remains in the initially introduced form 111. Partial dissolution may occur if the holding time is increased.

Next, a ZnC4 aqueous solution containing cellulose kept in a range of 1a-14eiC is dripped with water and stirred, thereby rapidly dissolving the cellulose.

The rate of dropping water is not limited to %.

The amount of water to be dropped should be at least 50% by weight, assuming that once the ZnCj solution excluding cellulose and the aqueous solution are dropped, there is no evaporation of water due to heating. If the amount of water is large, cellulose cannot be completely dissolved.The preferred amount of water to be dropped is ZmCj excluding cellulose after dropping water, and the concentration of the water droplet is approximately 7 to 7.
5 weight -. If you drop this water, it will be K.

The cellulose dissolves rapidly, yielding a homogeneous, high IllE suitable solution for spin traps.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 This example shows that a homogeneous solution can be obtained from commercially available cellulose.

Zinc chloride 111111f water 3PK dissolved, zinc chloride water soluble I
[Made by t-1Il. Commercially available leonia pulp 11
(Dr-1100) and heat it with a heater, SS
The temperature was raised to ℃. After 3 minutes, while stirring, i! 4 tons of warm water was added dropwise. Cellulose dissolves rapidly and evenly
It became t. 1! Solution of nits under white light under a polarizing microscope O crossed Nicols! When I looked at it, my field of vision was dark and there was no undissolved material. Next, when the cover glass is pressed with a finger to apply shear force to the solution, the field of view becomes bright and fluid birefringence can be observed.

EXAMPLE This example shows that uniform sii can be obtained at 101 degrees by using centrifugal force.

Zinc chloride 11f was dissolved in water NfK and commercially available Leonia pulp (D?-1200) lj! f was added, and first, the zinc chloride aqueous solution was placed in a centrifuge to uniformly permeate the cellulose, and centrifugal force was applied at a centrifugal effect of 100 G for 10 minutes. Remove fc ZnCL from centrifuge.

The mixture of aqueous solution and cellulose was heated to 90"C.

Hold at this temperature for 5 minutes and add 1L to 25°C while stirring.
4ff of water was added dropwise. A clear, non-brown, homogeneous solution was obtained. This solution also exhibited flow birefringence under crossed Nicols of a polarization III mirror.

Example 3 This example shows that an aqueous solution of Znct can be uniformly infiltrated into cellulose by squeezing, and a uniform solution can be obtained.

Zn cz by dissolving ZnCL chicken 10@f in water totv
, aqueous solution t-prepared well. Commercially available leonia pulp for this!
After opening the fibers and soaking them, the cellulose was left for 1 hour, the cellulose was pulled up, and the excess ZNCT1 aqueous solution was removed by rinsing.
Cellulose was sandwiched between the opening paper and pressed using a tabletop press at 50 cm/ai for 5 minutes.

Take out the cellulose, weigh it, and round and zeta-filter cellulose/Z.
The weight ratio of nC4.1 to 0 was approximately A. This is 1
The mixture was heated to 0°C and kept at this temperature for 3 minutes, and 8f of water was added dropwise with stirring to dissolve the cellulose and obtain a homogeneous solution.

The implementation side number example is commercially available microcrystalline cellulose (DP 麺鵞2・)
This shows that a highly concentrated and homogeneous solution can be obtained.

Dissolve ZnCts1@f in 2tK of water, feo this water f1
4 tons of powdered microcrystalline cellulose was put into 4111, heated to 91'cK, left for 3 minutes, and while stirring, 4 grams of room temperature water was added dropwise to dissolve the cellulose and fico was obtained. The solution was clear and homogeneous.

Example 2 This example demonstrates the production of fibers from a nine solution prepared from commercially available cellulose.

ZnC4ttof was dissolved in 5 otK of water to prepare an aqueous zinc chloride solution. Add this to ** Leonia pulp (Dp
mit...) 101 was opened and introduced. It was then heated and the temperature was maintained at 93°C. After holding this state for 5 minutes, 25°C water SOt was gradually added dropwise while stirring.
Cellulose was dissolved. ! A uniform cellulose solution was obtained with WJA. From the weight measurement at this time, it was found that the water in get t had evaporated during the dissolution process, and the weight fraction of cellulose with respect to the total type tK was 1845% K. When this solution was observed under a polarizing microscope under Ross Nicol, the field of view glowed brightly when shear force was applied, confirming flow birefringence. When there was no shear force, the field of view was dark and there were almost no undissolved materials.

Next, this solution was put into a small test spinning machine equipped with a screw, and spinning was performed. The spinning conditions are winding speed f 10 vn
Aerial discharge wet spinning was performed with an air gap of /m, draft 4., s5+. The coagulation bath used alcohol for -water coagulation and water for secondary coagulation, both at room temperature. Spinneret, spinneret i! The temperature was also room temperature. The resulting good fibers have orientation without a drawing process and have an Australian refractive index Δm=0.003!
! Met. In addition, the tensile strength, S f / 4, and elongation are 18 Is TEL) 7'C0 collection Example K A water-soluble tl@fK containing CN8 in a weight % degree of polymerization of 3...
Mix wood pulp (gelatinization degree 91- or more) iF prepared in 8! ! T? :[Stir for 80 minutes, then add 3.1 liters of water to this.
When f was added and stirred, the zeta cellulose rapidly dissolved. On the other hand, 7 snow weight of K CN8 - 13. Goose fK
1 t of cellulose was mixed and held for 13 CKI minutes, but the mixture had a high Kll#L color, some of which turned brown and became low molecular weight and dissolved, but it was not possible to obtain a uniform dope.

Comparative Example 1 This comparative example shows that a hot solution of salt can suitably dissolve cellulose at a high concentration without decomposing the cellulose.
Show that you are right.

This solution of zinc chloride liF dissolved in 3 tK of water was heated to 1.0°C.
1 ton of commercially available Leonia pulp was added, but no dissolution occurred. Further increase the temperature and add 1 mI CFC.
Then, the cellulose was dissolved with decomposition, resulting in a brown solution. but,#! The viscosity of this material was extremely low, and the cellulose that adhered to it was subject to decomposition and deterioration, so it could not be used as a raw material for spinning. Even when shearing force was applied under the crossed nicols of this smFi polarizing microscope, no flow am-folding was observed.

Comparative Example 2 In this comparative example, the a of ZnCL4 aqueous solution prepared in
If m is low, it indicates that the solution cannot be prepared.

A ZnC4 aqueous solution was prepared using 7mC121t and water atrc Hiroshi ML. One ton of commercially available Leonia pulp was added to this, and the temperature was maintained at es'crc. After 11 minutes, 4 f of water was added dropwise with stirring, but the cellulose #1 was hardly dissolved. A suitable cell solution is obtained,
It is possible to produce fibers and films useful for various purposes, and is extremely useful for the future development of the twill textile industry.

Patent applicant: Asahi Kasei Kogyo Co., Ltd.

Claims (1)

[Scope of Claims] Dawg resin composed of 5 to 80 parts by weight of cellulose and 95 to 80 parts by weight of zinc chloride aqueous solution. and the zinc chloride in the zinc chloride aqueous solution is at least go
cellulose dope i characterized in that the dope exhibits optical anisotropy; cellulose dope i as claimed in claim 1113, characterized in that the dope exhibits optical anisotropy; While maintaining the mixture 1i-80-105°C at 1@r, the zinc chloride aqueous solution lII & at least brocade weight -
A method for producing cellulose doug, characterized by adding water in an amount necessary to retain the amount of water.
A dope consisting of a zinc chloride aqueous bath solution] and a zinc chloride aqueous solution [zinc chloride accounts for at least 50% by weight]
Fibers and films obtained by wet-spinning cellulose dog, which is