JP2003266510A - Method for manufacturing cellulose molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for manufacturing a cellulose molded body with a stable quality and being industrially usable even when cellulose resources except chemical celluloses are reused. <P>SOLUTION: A method for manufacturing the cellulose molded body is characterized by dissolving a chemical pulp and a cotton, extruding a cellulose tertiary amine oxide solution with a content of the chemical pulp of at least 1 mass% to control a shape, and performing coagulation and solvent extraction. In addition, the method for manufacturing the cellulose molded body is characterized by using the cotton discharged as an industrial waste in a spinning process as the above described cotton, dissolving individually the chemical pulp and the cotton in tertiary amine oxide, and performing the complex extrusion of the cellulose solutions from an extrusion spinneret. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a cellulose molded body. More specifically, the present invention relates to a technique for forming a raw material for cellulose into a solution of a tertiary amine oxide or the like and forming it into a fiber, rod, sheet, film or the like.

[0002]

2. Description of the Related Art In recent years, a method for producing regenerated cellulose fibers has replaced the old viscose method with N-methylmorpholine-N-oxide (NMMO) hydrate, which has a low impact on the global environment, as a solvent. The method for producing regenerated cellulose fibers has attracted attention and has come to be used industrially, and as a representative thereof, Lyocell is well known. NMMO is a kind of tertiary amine oxide type organic solvent, and it is possible to use this solvent to fiberize old cloth, annual herbs, waste paper, etc. International Publication WO96 /
It is disclosed in Japanese Patent Publication No. 07778. However, it has been difficult to produce a cellulose molded product of stable quality as compared with the high-purity chemically refined pulp. In particular, there was a problem that unevenness in mechanical properties due to instability of the polymerization degree and instability in flow properties of a cellulose solution (hereinafter referred to as a dope for molding) were unstable, so that a breakage trouble during manufacturing was likely to occur. In addition, international publication WO98 / 2264
Japanese Unexamined Patent Publication (Kokai) No. 2 describes a technique of forming hemicellulose and cellulose having a high content of lignin into fibers. However, when lignin is contained in pulp, spinnability is decreased due to undissolved matter, There was a problem that the mechanical properties were not sufficiently high compared with the obtained fiber. In recent years, cotton wool discharged in the spinning process has become a problem as industrial waste in spinning factories, and its effective use is desired.

[0003]

DISCLOSURE OF THE INVENTION The present invention is intended to provide a technique for producing a high-quality cellulose molded product which is stable in quality even when reusing a cellulose resource other than chemical cellulose and is industrially high in quality. is there.

[0004]

That is, the present invention employs the following configurations. 1. The chemical pulp and cotton are dissolved, and a tertiary amine oxide solution of cellulose having a chemical pulp content of 1 mass% or more is discharged to control the morphology, and then coagulation and solvent extraction are performed. 1. A method for producing a cellulose molded body, 2. The method for producing a cellulose molded body according to the first aspect, wherein the cotton is cotton discharged as industrial waste in the spinning process. 3. The method for producing a cellulosic molded article according to the first aspect, wherein the chemical pulp and cotton are individually dissolved in a tertiary amine oxide solution and the solutions are mixed in a molding step. 4. The method for producing a cellulose molded body according to the third aspect, wherein each of the cellulose solutions is compositely discharged from an extrusion die.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. In the present invention, chemical pulp and cotton are essential, and two or more types of cellulose raw materials are used. The chemical pulp in the present invention is a pulp subjected to delignification treatment generally called chemical pulp, for example, sulfite pulp,
Examples include sulfuric acid pulp and soda pulp.

The cotton may be the cotton used in the spinning process, but it is preferable to use the fallen cotton discharged in the spinning process. Since cotton contains about 0.6% by mass of oil and fat, it is desirable to remove the oil and fat components in advance when using cotton. In the state of containing fats and oils, a high-quality molding dope cannot be obtained, and it often breaks in a molding method that has a process of stretching thinly such as fibers and films, and it is impossible to stably produce. is there. The oil and fat component can be extracted by treating with an organic solvent, and the organic solvent is preferably chloroform, hexane, or petroleum ether, but is not limited thereto.

The mixing ratio of the chemical pulp and cotton in the present invention is such that the ratio of the chemical pulp is 1% by mass or more. If the amount of the quality-controlled chemical pulp is less than 1%, the effect of improving the moldability of the dope in the case of cotton alone is small.

The degree of polymerization of the chemical pulp used is preferably selected appropriately according to the quality of the cotton to be combined. Since the degree of polymerization of cotton is relatively high, a combination that lowers the degree of polymerization of chemical pulp is preferable. When the quality of cotton is unstable, it is preferable to increase the mixing ratio of the chemical pulp.

The solvent for dissolving the cellulose raw material in the present invention is a tertiary amine oxide capable of dissolving cellulose at a concentration of 10% by mass or more, and the N-mitylmorpholine-N-oxide hydrate is typical. Is. This tertiary amine oxide solution may contain an antioxidant, a pH adjuster, and a third component for adjusting the fluid characteristics of the solvent.

In the present invention, when the cellulose is dissolved in the tertiary amine oxide solution, the dissolution rate varies depending on the cellulose raw material, and therefore it is necessary to adjust the pulverization conditions and dissolution time of the raw material according to the respective dissolution characteristics. In addition, it is necessary to change the conditions for filtering the foreign matter in the raw material according to the amount and size of the foreign matter contained. Therefore, it is preferable to separately add the chemical cellulose and the cotton to the dissolution equipment.

This method is advantageous when the dissolved cellulose dope is mixed with a liquid or individually extruded to form a composite. That is, it is difficult to uniformly disperse and mix a plurality of types of cellulose in the pulverized cellulose state, but in a liquid state, uniform mixing can be performed by appropriately using a mixing device. As a means for uniformly mixing, it is possible to use a kneader, a twin-screw extruder, a single-screw extruder having a mixing mechanism, or a horizontal or vertical stirring can in an undissolved or semi-dissolved slurry state or a completely dissolved state. it can. When mixing in a short time, an apparatus capable of mixing at a high shear rate with a small clearance of a stirring bar is preferable. On the other hand, when a plurality of types of cellulose are individually extruded, individual dissolution is essential.

In the present invention, in order to obtain a molded product, it is necessary to discharge the cellulose solution so as to form a prototype of the molded product. When a fiber is produced, a spinneret is produced, when a film is produced, a tertiary die amine oxide solution of cellulose is discharged from a slit die or other mold gate, and the shape is uniaxially stretched, blow stretched, or foamed. Control. The present invention is not limited to the above examples regarding a solution morphology control method. A molding method suitable for a desired molded product can be selected.

The solution whose shape is controlled by being discharged is brought into contact with a non-solvent to coagulate and fix the shape. As the non-solvent used here, water, ketones such as lower alcohol and acetone can be used, but water is preferable when industrially used in large amounts. During the coagulation and the subsequent steps, the solvent in the molded body is extracted. Although non-solvent water or the like can be used for extraction, a supercritical fluid or the like may be used.

The molded body may be used as a porous body containing a non-solvent, but when it is used as a fiber or a film, a drying step for removing the non-solvent in the molded body is necessary. Drying can be performed by any method such as heating with hot air, air drying at room temperature, and freeze drying. It is also possible to crimp the fibers after drying or before drying, or to cut and use the fibers, or to cut the film into a tape and use it as a flat yarn. It is also possible to perform dyeing, rubbing, surface treatment or modification treatment before or after processing the molded product into a knitted fabric or a woven fabric.

Further, by carrying out composite molding such as multi-layer discharge of each molding dope obtained from each different type of cellulose, it is possible to manufacture a cellulose molded body of stable quality. As a method of composite-molding different types of cellulose, a known sea-island or side-by-side composite spinneret, a multi-layer slit die, or the like, which is mixed in a pipe with a static mixer, can be selected. A method of discharging independently from the die and joining before solidification may be used.

As described above, the molded product according to the present invention can be used as a material for clothing, a packaging material, and an industrial material.

[0017]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to these. The measuring method used in the present invention is as follows. <Measurement of Degree of Polymerization of Cellulose> The degree of polymerization of cellulose was measured by the Cucumber-ethylenediamine method (Polymer Material Society, edited “Polymer Material Test Method 2”, page 267, Kyoritsu Publishing (19
65)). A sample was weighed 0.0075 to 0.0085 g and put into a cucumber-ethylenediamine solution.
After stirring at room temperature for about 30 minutes to completely dissolve the sample, the temperature was kept constant at 20 ° C. and the viscosity was measured using an Ubbelohde viscometer to determine the degree of polymerization.

<Measurement of Moisture Content in Dope> Moisture content in the dope is measured by a trace moisture measuring device (manufactured by Hiranuma Sangyo Co., Ltd., model A).
It was measured by Q-7). About 1 g of the test piece was weighed, about 10 ml of absolute ethanol (99.5%) was added, and the mixture was allowed to stand overnight at room temperature and then measured.

<Example 1> Chemical cellulose (pulp) 5
5600 g of NMMO solvent containing 65 g and 50% by weight of water
And were heated to 110 ° C. with stirring, and the pressure was reduced to adjust a dope having a cellulose concentration of 15%. The water content in the dope was 10.3%. Furthermore, the powdered cotton that was discharged from the Shogawa Plant of Toyobo Co., Ltd. in the spinning process as industrial waste was washed with hexane to remove fats and oils, and then cut and pulverized to obtain powder 55.
0 g to 5000 g of NMMO solvent containing 50% by weight of water
And were heated to 110 ° C. with stirring, and the pressure was reduced to adjust a dope having a cellulose concentration of 16%. The water content in this dope was 11.2%. Both of these two types of dope were amber-colored viscous products. The degree of polymerization of each cellulose obtained by coagulating and precipitating chemical cellulose and cotton single dope with water, washing and drying is 620 and 2160, respectively.
Met.

These dopes were filled in two plunger type supply tanks each equipped with a piston. The dope supplied from these is metered through individual gear pumps such that the mass ratio of the chemical cellulose dope is 25 with respect to the cotton dope 75, and the diameter is 3.2 m.
The mixture was mixed using a Kenix type static mixer consisting of m and 18 elements and discharged from the spinneret.

A spinneret having an exit diameter of 200 μm with 10 holes was used, and the total dope discharge amount was 6.7 g.
/ Min. The temperature of the spinneret was 108 ° C, and the yarn immediately below was cooled with air adjusted to 15 ° C with a wind speed of 1.2 m / sec. Depth 50 provided 300 mm below the nozzle
After being brought into contact with water with a mm coagulation funnel, it was run on a Nelson type roller on which water was dripped and wound up. The Nelson roller speed is 450 m / min and the fineness after air drying is 2
It was 3.3 dtex. Table 1 shows the physical properties of the obtained regenerated cellulose fiber. It has similar mechanical properties as fibers obtained from chemical cellulose.

Comparative Example 1 Only the single dope obtained from the chemical cellulose of Example 1 was filled in two plunger type supply tanks equipped with pistons. The supplied dope was metered into the spinneret through a gear pump. The spinneret used had a 10-hole outlet diameter of 200 μm, and the total dope discharge rate was 6.7 g / min. The temperature of the spinneret is 105 ° C, and the wind speed is 1.2m just below it.
The yarn was cooled with air adjusted to 15 ° C./sec. A coagulation funnel having a depth of 50 mm provided 300 mm below the nozzle was brought into contact with water, and then run on a Nelson roller on which water was dripped and wound up. The speed of the Nelson roller was 450 m / min, and the fineness after air drying was 23.1 dtex. Table 1 shows the physical properties of the obtained regenerated cellulose fiber.

Comparative Example 2 Only the single dope obtained from the cotton of Example 1 was filled in two plunger type supply tanks equipped with pistons. The supplied dope was metered into the spinneret through a gear pump. 1 spinneret
A material having a 0-hole outlet diameter of 200 μm was used, and the total dope discharge amount was 5.2 g / min. The temperature of the spinneret was 105 ° C, and the temperature immediately below was 15 ° C with a wind speed of 1.2 m / sec.
The yarn was cooled with air adjusted to. 300 from the nozzle
After being brought into contact with water using a coagulation funnel having a depth of 50 mm, which was provided below the plate, the film was run on a Nelson type roller on which water was dripped and wound up. Nelson roller speed is 350
The fineness after air-drying at m / min was 23.0 dtex. Table 1 shows the physical properties of the obtained regenerated cellulose fiber.

<Example 2> Chemical cellulose (pulp) 6
5600 g of NMMO solvent containing 04 g and 50% by weight of water
And were heated to 110 ° C. with stirring, and the pressure was reduced to adjust a dope having a cellulose concentration of 16%. The water content in the dope was 9.7%. The same fallen cotton as in Example 1 was washed with hexane to remove fats and oils, and then cut and crushed to obtain powders 529 g and 50
The NMMO solvent containing 5000% by mass of water was heated to 110 ° C. with stirring and the pressure was reduced to a cellulose concentration of 1
A 4% dope was prepared. Moisture content in this dope is 1
It was 1.7%. Both of these two types of dope were amber-colored viscous products. The degrees of polymerization of the respective celluloses obtained by coagulating and precipitating each of the chemical cellulose and the cotton single dope with water, washing and drying were 640 and 2010, respectively.

These dopes were filled in two plunger type supply tanks each equipped with a piston. The dope supplied from these was supplied to a sheath core type spinneret through individual gear pumps so that chemical cellulose came to the sheath and cotton to the core. The mass ratio of the discharge amount was such that the cotton dope was 65 and the chemical cellulose dope as the sheath component was 35. A 10-hole sheath core type spinneret having an outlet diameter of 200 μm was used, and the total dope discharge rate was 6.7 g / min. The temperature of the spinneret is 108
The temperature was set to 0 ° C, and the yarn immediately below was cooled with air adjusted to 15 ° C at a wind speed of 1.2 m / sec. A coagulation funnel having a depth of 50 mm provided 300 mm below the nozzle was brought into contact with water, and then run on a Nelson roller on which water was dripped and wound up. The Nelson roller speed was 450 m / min, and the fineness after air drying was 23.3 dtex. As in this example, it is possible to confine the cotton-derived cellulose component inside the molded body. Table 1 shows the physical properties of the obtained regenerated cellulose fiber. It has similar mechanical properties as fibers obtained from chemical cellulose.

[0026]

[Table 1]

As is clear from Table 1, those satisfying the requirements of the present invention can obtain mechanical properties comparable to regenerated cellulose fibers obtained from chemical cellulose alone.

[0028]

EFFECTS OF THE INVENTION According to the present invention, the cotton discharged as industrial waste in the spinning process which is non-wood as a raw material and the high-quality wood pulp are used in combination or by composite molding, It is possible to produce a cellulosic molded product that is kind to the global environment and has stable quality.

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) C08L 1:00 C08L 1:00

Claims (4)

[Claims] 1. A method in which a chemical pulp and cotton are dissolved and a tertiary amine oxide solution of cellulose having a chemical pulp content of 1% by mass or more is discharged to control the morphology,
A method for producing a cellulose molded body, which comprises coagulating and solvent-extracting. 2. The method for producing a cellulose molded body according to claim 1, wherein the cotton is a cotton discharged as industrial waste in the spinning process. 3. The method for producing a cellulosic molded article according to claim 1, wherein the chemical pulp and cotton are individually dissolved in a tertiary amine oxide solution and the solutions are mixed in a molding step. 4. The method for producing a cellulose molded body according to claim 3, wherein each of the cellulose solutions is compositely discharged from an extrusion die.