JPH07189019A - Production of regenerated cellulose formed product - Google Patents

Abstract

PURPOSE:To easily obtain in an industrially advantageous way a regenerated cellulose formed product excellent in mechanical properties by dry jet-wet spinning or wet spinning method using a cellulose solution prepared by dissolving cellulose in a tertiary amine oxide-water mixed solvent. CONSTITUTION:A spinning is conducted using, as a coagulation bath, an aqueous solution containing at least one kind of substance selected from water-soluble neutral organic compounds, water-soluble inorganic neutral salts, water-soluble caustic alkali compounds and water-soluble salts and prepared by dissolving cellulose in an N-methylmorpholine-N-oxide-water mixed solvent. The coagulated formed product obtained is then heat treated at 100-150 deg.C to obtain a regenerated cellulose formed product good in balance between mechanical strength and elongation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a regenerated cellulose molded product, and more specifically, a regenerated cellulose molded product is obtained by an aqueous coagulation method using a stock solution containing cellulose tertiary amine oxide-aqueous solvent. In this case, the present invention relates to a method for industrially advantageous production of a regenerated cellulose molded article having excellent mechanical properties, which comprises using a novel aqueous coagulating liquid and further heat treatment.

[0002]

2. Description of the Related Art As a conventional method for producing a regenerated cellulose molded article, cellulose or its derivative is dissolved in a solvent,
A method for obtaining a molded article such as a fiber or a film from the obtained solution is known. As such a method, there are a viscose method and a copper-ammonia method, but these methods involve complicated chemical reactions and require not only a long process but also various environmental pollutions.

In recent years, research on a solvent for cellulose has progressed, and some solvents having a strong dissolving power for cellulose have been found. As a result, as in the case of synthetic resin, it became possible to obtain a stock solution by simply dissolving cellulose in a solvent. Among these solvents, tertiary amine oxides, especially N-methylmorpholine-N-oxide, are specific and excellent solvents for cellulose, and there are some methods for producing regenerated cellulose fibers and films using the same. Proposed. Among them, for example, the method disclosed in Japanese Patent Publication No. 60-28848, that is, the cellulose dissolved in a mixed solvent consisting of N-methylmorpholine-N-oxide and water,
The method of producing a regenerated cellulose molded product by the so-called dry jet wet spinning method using water as a coagulant has been most noticeable in practical use. In this method, the solvent system is extremely simple and substantially only N-methylmorpholine-N-oxide can be used, and the recovery process can be simplified. A high-concentration molding stock solution having a cellulose concentration of 10 to 40% by weight can be used. In addition, the conventionally known dry jet wet spinning method can be easily applied, water is used as the coagulating liquid, which is convenient in the molding and recovery steps, and there is virtually no side reaction in the process, and there is no pollution. It has features such as a close manufacturing process, and some have started production on an industrial scale.

However, according to this method, when a simple dry jet wet spinning method is used to perform stretching in an uncoagulated state during the fiber or film forming process, a molded article having mechanical properties that can withstand practical use is obtained. Hard to get. Therefore, in order to improve the mechanical properties of the molded product, it is general to devise the spinning device so as to perform solidification and drawing at the same time. For that purpose,
For example, Japanese Examined Patent Publication No. 60-28848 discloses an improved dry jet in which a water supply roller is provided between the spinneret and the water surface to supply a small amount of water to the surface of the spinning dope to be stretched, and the spinning dope is coagulated for stretching. A wet spinning device, an improved dry jet wet spinning device in which a mist chamber is provided and water is supplied from a conduit in the form of mist droplets to perform stretching while coagulating a spinning dope is disclosed. According to this apparatus, not only the fiber production process is extremely simple, but also high-speed spinning at a spinning speed of 100 m / min yields regenerated cellulose fibers having mechanical properties comparable to those of conventionally known strong rayon. it can. However, the mechanical properties of the regenerated cellulose molded product improve with an increase in the draw ratio, that is, as the spinning and film-forming speed increases. Therefore, in order to obtain a molded product having high mechanical properties, further spinning and Since it is necessary to increase the film speed and the film is solidified simultaneously with stretching at a high speed, there is a drawback that there is a certain limit in terms of equipment or operation.

In order to improve such a defect, a conventionally known ordinary dry jet wet spinning method is used, and as a method for improving the mechanical properties of regenerated cellulose fiber without particularly increasing the spinning speed, a specific additive is added to the spinning dope. H. Chanzy et al.
lymer 1990 31 400). According to the method, a cellulose solution obtained from an N-methylmorpholine-N-oxide-water mixed solvent is mixed with n-propyl gallate and ammonium chloride or calcium chloride to prepare a spinning stock solution, which is conventionally known as a dry solution. By the jet wet spinning method, regenerated cellulose fibers having excellent strength can be easily obtained at a relatively low spinning speed of 20 to 200 m / min. N-propyl gallate is known as an antioxidant for cellulose (for example, Japanese Patent Publication No. 3-29).
No. 819), and therefore, a feature of the method is that regenerated cellulose fibers having excellent mechanical properties are obtained by using a spinning dope containing ammonium chloride or calcium chloride. In particular, it has been shown that the addition of ammonium chloride improves the mechanical properties, especially the strength, by 1.4 to 1.8 times as compared with that without addition. However, the fiber obtained by this method has strength but no elongation. That is, there is a fatal problem that the fiber is hard but brittle, and its practical range is extremely limited.Additional ammonium chloride or calcium chloride also acts as a coagulation accelerator for cellulose, and the spinning stock solution is stable over time. From the viewpoint of sex,
It is not preferable.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a special spinning or film-forming apparatus for obtaining a regenerated cellulose molded article by an aqueous coagulation method using a stock solution for forming a tertiary amine oxide of cellulose and an aqueous solvent. It is an object of the present invention to provide a method for producing a regenerated cellulose molded article having excellent mechanical properties even at a relatively low spinning speed without requiring the above.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the problems, the present inventors have found that a cellulose solution prepared by dissolving a tertiary amine oxide-water mixed solvent is used as a forming stock solution and water is used as a coagulating bath. In the so-called conventionally known dry jet wet spinning method or wet spinning method, a substance capable of changing the coagulation action of the coagulation bath, a water-soluble neutral organic compound, a water-soluble inorganic neutral salt, a water-soluble caustic alkali, a water-soluble acid Coagulation using the coagulation liquid with and added, and then drying and heat treatment under appropriate conditions to remarkably improve not only the strength but also the elongation without the need for excessive stretching. We have found the surprising fact that we can obtain cellulosic molded articles,
By appropriately selecting the type of compound to be added and the drying and heat treatment conditions, it is possible to easily produce a regenerated cellulose molded product having a wide practical range with mechanical properties according to the application and purpose by an extremely advantageous method in practice. The present invention has been completed and the present invention has been completed. That is, the present invention provides an industrially advantageous and simple method for producing a cellulose molded article having excellent mechanical properties by using a conventionally known apparatus without requiring a special spinning or film forming apparatus. It is a thing.

The first essence of the present invention resides in that an aqueous solution containing a substance capable of changing the coagulation action of the coagulation bath (hereinafter also referred to as an additive) is used as the coagulation liquid. When an aqueous solution to which an additive is added is spun as a coagulating liquid, the osmotic pressure of water of the coagulating liquid with respect to the liquid yarn in the coagulating bath (filamentary spinning dope discharged from the spinning nozzle) changes. That is, it is considered that the coagulation due to the diffusion of water into the liquid thread is suppressed, and the thread formation by so-called concentrated coagulation in which the thread formation proceeds by the diffusion of the solvent from the liquid thread into the coagulation bath is promoted. Here, strong alkalis and strong acids may have a hydrating effect on cellulose, but it is presumed that the effect of changing the osmotic pressure of water is the main effect when considering the effects exhibited by other neutral substances. There is no difference in the cross-sectional shape of the yarn regardless of the presence or absence of additives and the type of additives, and by using additives, bonding between molecules or higher-order structures (precipitated particle structure formed during the solidification process) It has been found that the properties and homogeneity are improved and the denseness of the fiber structure is improved.

Examples of the additives that can be used include water-soluble neutral organic compounds, water-soluble inorganic neutral salts, water-soluble caustic alkalis and water-soluble acids. Preferred water-soluble organic compounds are urea, pyrrolidone and ε-. Caprolactam is ammonium nitrate, ammonium chloride, sodium sulfate, sodium chloride, potassium rhodanate, sodium rhodate, magnesium chloride, zinc chloride, calcium chloride, tin chloride as the water-soluble inorganic neutral salt, and water as the water-soluble caustic alkali. Examples of the water-soluble acid include sodium oxide, potassium hydroxide, calcium hydroxide and zinc hydroxide, and sulfuric acid, nitric acid, phosphoric acid, formic acid and monochloroacetic acid. The concentration of various additives added to the coagulation liquid varies depending on the composition of the molding solution, the stretching conditions, the drying / heat treatment conditions or the intended use of the molded product, and cannot be specified in any way, but generally 0.1 to 10% by weight is sufficient. Manifest its effect. Although it depends on heat treatment conditions, etc., in general, when strength is required, a water-soluble inorganic neutral salt such as sodium sulfate, and when elongation is required, a water-soluble caustic alkali such as sodium hydroxide or sulfuric acid is used. It is preferable to use a water-soluble acid such as, or a water-soluble neutral organic compound such as urea when an intermediate thereof is required.

Next, the second gist of the present invention is that the wet molded product after solidification is dried and heat-treated under appropriate conditions.
That is, by drying and heat treating the wet molded article under appropriate conditions, the denseness of the fiber structure is dramatically improved,
That is, the drying / heat treatment temperature plays an extremely important role in the densification of the fiber structure, and the selection of appropriate drying / heat treatment conditions is extremely effective for the densification and homogenization of the fiber structure of the regenerated cellulose molding. I found it. The drying / heat treatment temperature depends on the composition of the coagulation bath used, the purpose of use of the molded product, etc., but is 15 from the glass transition temperature of cellulose (it is said to be -30 ° C to 160 ° C).
If the temperature is in the range of from -20 ° C to a thermal decomposition temperature or less, the purpose will be satisfied, but usually 100 ° C or more and 200 ° C or less, more preferably 100 ° C in which the risk of thermal deterioration of cellulose is low.
Above about 150 ° C is appropriate. However, it is necessary to thoroughly wash with water to remove the solvent and coagulation liquid during the drying / heat treatment, but the drying / heat treatment apparatus and method are not particularly limited, and for example, dry heat treatment in a relaxed state is sufficient. The effect can be expressed in.

In carrying out the present invention, cellulose is dissolved in a mixed solvent consisting of tertiary amine oxide and water, but the cellulose used is not particularly limited, and pulp which is usually used for industrial purposes is sufficient. . The method for dissolving the cellulose is not particularly limited, and the cellulose may be dissolved in a mixed solvent of tertiary amine oxide and water according to a conventionally known method. Examples of these detailed methods include various methods and apparatuses described in JP-B-60-28848, but the present invention is not limited to the dissolution method or the apparatus. As the tertiary amine oxide used in the present invention, any tertiary amine oxide that dissolves cellulose and mixes with water and is stable to water can be used. For example, dimethylethanolamine oxide, triethylamine oxide, certain monocyclic N-methylamine-N-oxides such as N-methylmorpholine-N-oxide, N-methylpiperidine-
N-oxides, N-methylpyrrolidine-N-oxides as well as other cyclic amine oxides in which the amine oxide group is present outside the ring, such as dimethylhexylamine-
Although N-oxide and the like can be mentioned, N-methylmorpholine-N-oxide is preferable from a practical point of view. The composition of the cellulose solution varies depending on the type of cellulose, the type of solvent, the molding apparatus, the molding conditions and the like and is not particularly limited, but generally about 5% to 40% by weight of cellulose and about 90% to 40% by weight of a tertiary amine oxide. %, Water 5 to about 20% by weight is preferred.

In the present invention, it is optional to add various additives for the purpose of preventing deterioration of cellulose at the time of dissolution or after dissolution, for example, significant disintegration or coloring of cellulose chains. Examples of additives added for these purposes include compounds disclosed in JP-B-3-29819, such as L (+) ascorbic acid and hydroquinone.
Examples include isopropyl gallate and the like.

The obtained cellulose solution is generally kept at 70 ° C. or higher and 150 ° C. or lower, preferably 90 ° C. or higher and 130 ° C. or lower, and is first formed into a fiber or film in the air or an aqueous solution containing the above-mentioned additives by spinning or extrusion. It is then stretched with or after coagulation of the cellulose in order to improve the mechanical properties of the molding. Cellulose solution extruded from a molding nozzle or die is generally stretched by being stretched by being stretched at a speed higher than its extrusion speed, but the degree of stretching depends on the spinning (or film-forming) stretch ratio, that is, the linear velocity of the solidified molded product. Determined by the value divided by the linear velocity delivered from the nozzle or die. Tokusho Sho 6
The method described in 0-28848 is based on the fact that the cellulose molecules are oriented in a solution by stretching before coagulation, and the properties of the obtained cellulose will be improved before complete coagulation of the cellulose. Therefore, in order to improve the mechanical properties of regenerated cellulose, high stretching before complete coagulation is essential,
Usually, a high draw ratio of 3 or more, particularly a draw ratio of 20 to 30 is required. In the case of the present invention, the expression mechanism of the mechanical properties of regenerated cellulose is different from the known technique,
It is largely based not only on the stretching but also on the selection of the composition of the coagulating liquid and the improvement of the mechanical properties by drying and heat treatment, and the above-mentioned condition, that is, high stretching before complete coagulation of cellulose is not essential. Therefore, it can be easily understood that the method of the present invention provides a method for producing a regenerated cellulose molded article, which is greatly improved in terms of equipment and operation control. Of course, depending on the purpose, even if the molded article obtained by the conventional technique as described above is completely solidified in the coagulating bath of the present invention, and further subjected to drying and heat treatment, it does not go against the gist of the present invention. That is, it may be stretched while being solidified, or stretched after solidification is not contrary to the gist of the present invention, and the effect of the present invention is compensated by adopting a solidification and stretching process according to the purpose. Doing is optional.

[0014]

EXAMPLES The present invention will be described in more detail with reference to examples below, but it is needless to say that the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In addition,
In the following examples, percentages and parts mean percentages by weight and parts by weight. Example 1 [Example: Sample 1-1 to Sample 4-4; Comparative Examples 1 to 4] 840 parts of N-methylmorpholine-N-oxide (manufactured by Nippon Emulsifier Co., Ltd.) containing 13.3% of water and water. Wood pulp containing approximately 6.0 percent (KS
100 parts of powder: manufactured by Kojin Co., Ltd. was charged into a Werner crusher with a jacket and stirred at 90 ° C. for 2 hours to prepare a solution having a cellulose content of about 10%. This solution was spun by the dry jet wet spinning method to obtain a regenerated cellulose fiber. Air gap is 10mm, spinning temperature is 100 ℃, nozzle is 0.10mmφ
× 20 holes, the coagulation bath temperature was 20 ° C. As the coagulation bath, as an example, Samples 1-1, 2, 3 and 4 were 10% urea aqueous solutions, and Samples 2-1, 2, 3 and 4 were 1%.
A 0% ammonium nitrate aqueous solution was added to sample 3-1,
2, 3 and 4 are 9% sodium sulfate aqueous solution,
Samples 4-1, 2, 3 and 4 were spun using 5% aqueous sodium hydroxide solution in the coagulation bath. In Comparative Examples 1, 2, 3 and 4, water was used in the coagulation bath for spinning.
The spinning draft at the time of spinning (the ratio of the average flow velocity (v ₀ ) of the spinning stock solution passing through the spinning nozzle to the winding speed (v ₁ ) of the coagulated yarn) was 1.01. Here, it is noted that spinning is performed in a region where the spinning draft is low. The obtained yarn (coagulated yarn) was washed with water to remove the solvent, and then dried and heat-treated. The drying and heat treatment temperatures were room temperature (19 ° C to 21 ° C), 100 ° C, 150 ° C and 200 ° C. The drying and heat treatment were performed in a relaxed state and the shrinkage was free. The properties of the regenerated cellulose fibers thus obtained are summarized in Table 1. The effects of the additives added to the coagulation bath are clear from Samples 1-1, 2, 3 and 4 of Table 1 and Comparative Example 1. Samples 2-1, 2,
3 and 4 and Comparative Example 2, Samples 3-1, 2, 3 and 4 and Comparative Example 3, Samples 4-1, 2, 3 and 4 and Comparative Example 4, suitable drying and heat treatment temperatures are fibers. It can be seen that the mechanical properties of are greatly improved. The regenerated cellulose fibers obtained from the conventional water coagulation bath had a lower elongation when the strength was increased, and a lower strength when the elongation was increased. In other words, in all cases, the toughness was only low, but the regenerated cellulose fiber obtained by the method of the present invention generally has high toughness, and has extremely advantageous properties in practical use with balanced strength and elongation. Can be said to be a thing.

Example 2 Wood pulp (K) containing 850 parts of N-methylmorpholine-N-oxide (manufactured by Nippon Emulsifier Co., Ltd.) containing 13.3% of water and about 6.0% of water.
160 parts of S powder: manufactured by Kojin Co., Ltd.) were placed in a Werner crusher with a jacket and stirred at 90 ° C. for 2 hours to prepare a solution having a cellulose content of about 15%. This solution was spun by the dry jet wet spinning method to obtain a regenerated cellulose fiber. Air gap is 35 mm, spinning temperature is 120 ° C, nozzle is 0.085 m
mφ × 17 holes, coagulation bath temperature was 20 ° C. 7% aqueous solution of sodium sulfate, magnesium chloride 5%
An aqueous solution and a 3% aqueous solution of sulfuric acid were prepared, and a water bath was used for comparison. The obtained sample was thoroughly washed with water to remove the solvent, and then dried and heat-treated at 120 ° C. for 10 minutes. The fiber property results of the dry heat treated product are shown below. Coagulation bath Fineness (d) Strength (g / d) Elongation (%) Young's modulus (g / d) Sodium sulfate 9% aqueous solution 3.4 3.5 25 120 Sodium sulfate 9% aqueous solution 1.7 3.5 3.5 25 130 5% aqueous solution of magnesium chloride 3.4 2.7 23.4 100 5% aqueous solution of magnesium chloride 1.7 2.5 24.0 105 5% aqueous solution of sulfuric acid 3.4 2.7 23.4 103 5% aqueous solution of sulfuric acid 1. 7 2.5 21.0 100 Water 3.4 1.1 10.4 95 Water 1.7 1.0 9.0 85 From the above results, compared with the case of using water as a comparative example as a coagulating bath, It is noted that the fiber has excellent mechanical properties when spun by the method. It is especially effective for fine fibers.

Example 3 A spinning solution having a cellulose content of about 15% was prepared in the same manner as in Example 2. This solution was spun by the dry jet wet spinning method to obtain a regenerated cellulose fiber. Air gap is 5 mm, spinning temperature is 10
The temperature was 0 ° C., the nozzle was 0.35 mmφ × 17 holes, and the coagulation bath temperature was 20 ° C. Spin draft from 0.3 to 5.0
Changed in range. 7% aqueous solution of sodium sulfate,
A 10% aqueous solution of sodium rhodate and a 7% aqueous solution of ε-caprolactam were used, and a water bath was used for comparison. The obtained fiber is thoroughly washed with water to remove the solvent, and then 150 ° C,
Dry heat treatment was performed for 5 minutes. The fiber property results of the dry heat treated product are shown below. Coagulation bath: 7% aqueous solution of sodium sulfate Spinning draft Fineness (d) Strength (g / d) Elongation (%) Young's modulus (g / d) 0.3 3.1 4.0 14.0 130 1.0 3. 1 4.1 13.0 145 2.5 3.1 4.3 4.3 10.0 150 4.0 3.1 4.5 9.5 155 5.0 3.1 4.5 4.5 7.5 160 Coagulation bath: Sodium rhodate 10% aqueous solution Spinning draft Fineness (d) Strength (g / d) Elongation (%) Young's modulus (g / d) 0.3 3.1 3.9 14.0 110 110 1.0 3.1 3 1.9 11.0 130 2.5 3.1 4.0 9.0 140 140 4.0 3.1 4.2 7.5 147 5.0 3.1 4.3 6.5 155 Coagulation bath: ε- Caprolactam 7% aqueous solution Spinning draft Fineness (d) Strength (g / d) Elongation (%) Young's modulus (g / d) 0.3 3.1 3.0 13.0 95 95 1.0 3.1 3.1 11.0 100 2.5 3 1 3.4 8.0 120 4.0 4.0 3.1 4.2 6.5 127 127 5.0 3.1 4.3 5.8 135 Coagulation bath: water (comparative example) Spinning draft Fineness (d) Strength ( g / d) Elongation (%) Young's modulus (g / d) 0.3 3.1 1.9 7.0 95 95 1.0 3.1 1.9 6.5 6.5 100 2.5 3.1 2. 0 6.0 103 4.0 3.0 2.1 2.1 4.5 107 5.0 3.1 2.1 3.8 108 The present invention is based on the above results as compared with the case of using water as a coagulating bath as a comparative example. It is noteworthy that the mechanical properties of the fiber are excellent even when the spinning draft is low when the fiber is spun by the method (1). Further, even if the spinning draft becomes high, the reduction rate of the cutting elongation of the fiber is small.

Example 4 A spinning solution having a cellulose content of about 10% was prepared in the same manner as in Example 1. This solution was spun by the dry jet wet spinning method to obtain a regenerated cellulose fiber. Air gap 3mm, spinning temperature 100
C., the nozzle was 0.10 mm.phi..times.20 holes, and the coagulation bath temperature was 20.degree. Sodium sulfate 9% aqueous solution in coagulation bath,
A 10% aqueous solution of urea was used and a water bath was used for comparison.
The obtained fiber was thoroughly washed with water to remove the solvent, and then dried and heat-treated at each temperature for 10 minutes. The fiber property results of the dry heat treated product are shown below. Coagulation bath: sodium sulfate 9% aqueous solution Drying temperature Fineness (d) Strength (g / d) Elongation (%) Young's modulus (g / d) Room temperature 2.5 2.6 33.0 85 100 ° C 2.5 3. 1 30.0 120 150 ° C 2.5 4.2 4.2 12.5 150 200 ° C 2.5 2.0 10.5 70 250 ° C 2.5 0.8 3.5 3.5 20 Coagulation bath: 10% urea aqueous solution Drying temperature Fineness (d) Strength (g / d) Elongation (%) Young's modulus (g / d) Room temperature 2.5 1.7 25.0 50 100 ° C 2.5 2.5 22.1 90 150 ° C 2.5 3.0 12.0 115 200 ° C. 2.5 1.4 5.6 60 60 250 ° C. 2.5 0.5 0.5 1.5 18 Coagulation bath: water (comparative example) Drying temperature Fineness (d) Strength (g / d ) Elongation (%) Young's modulus (g / d) Room temperature 2.5 0.9 18.3 55 100 ° C 2.5 1.2 10.9 80 150 ° C 2.5 2.0 7.0 7.0 95 200 ° C 2.50 .9 3.8 67 250 ° C. 2.5 0.5 1.2 1.2 17

[0018]

As described above, according to the present invention, a special spinning or film forming apparatus is not required, and the mechanical properties which cannot be achieved by the prior art are excellent by using the conventionally known apparatus. It is possible to easily produce a regenerated cellulose molded product, and its practical significance is extremely large.

[Table 1]

Claims (6)

[Claims] 1. When forming a cellulose solution using a tertiary amine oxide-water mixed solvent by a dry jet wet spinning method or a wet spinning method, the coagulating liquid is a water-soluble neutral organic compound or a water-soluble inorganic neutral salt. A method for producing a regenerated cellulose molded article, which is an aqueous solution containing one or more substances selected from water-soluble caustic alkali and water-soluble acid, and heat-treating the obtained coagulated molded article. 2. The method for producing a regenerated cellulose molded article according to claim 1, wherein the tertiary amine oxide is N-methylmorpholine-N-oxide. 3. The water-soluble neutral organic compound is urea, pyrrolidone, ε-caprolactam, and the water-soluble inorganic neutral salt is ammonium nitrate, ammonium chloride, sodium sulfate, sodium chloride, potassium rhodanate, sodium rhodanate, magnesium chloride, chloride. Zinc, calcium chloride, tin chloride,
The regenerated cellulose molded article according to claim 1 or 2, wherein the water-soluble caustic is sodium hydroxide, potassium hydroxide, calcium hydroxide, zinc hydroxide, and the water-soluble acid is sulfuric acid, nitric acid, phosphoric acid, formic acid, or monochloroacetic acid. Manufacturing method. 4. The heat treatment method is performed at a temperature of 100 ° C. or higher and 200.
The method for producing a regenerated cellulose molded article according to claim 1, 2 or 3, which is a dry heat treatment at ℃ or less. 5. The method for producing a regenerated cellulose molded article according to claim 1, wherein the regenerated cellulose molded article is a fiber. 6. The method for producing a regenerated cellulose molded article according to claim 1, wherein the regenerated cellulose molded article is a film.