JP4160108B1 - Method for producing amorphous cellulose - Google Patents

Abstract

An object of the present invention is to provide a production method excellent in productivity, capable of efficiently obtaining non-crystalline cellulose having a reduced cellulose I-type crystallinity from a cellulose-containing raw material.
SOLUTION: A method for producing amorphous cellulose from a cellulose-containing raw material having a cellulose I-type crystallinity of more than 33% represented by the following calculation formula (1), wherein the remaining amount obtained by removing water from the raw material Using a raw material having a cellulose content of 20% by mass or more in the component, and treating the cellulose-containing raw material with a vibration mill filled with a rod, the cellulose I-type crystallinity is reduced to 33% or less. A method for producing amorphous cellulose.
Cellulose type I crystallinity (%) = [(I _22.6 -I _18.5 ) / I _22.6 ] × 100 (1)
[I _22.6 is the diffraction intensity of the lattice plane (002 plane) (diffraction angle 2θ = 22.6 °) in X-ray diffraction, and I _18.5 is the diffraction intensity of the amorphous portion (diffraction angle 2θ = 18.5 °). Show
[Selection figure] None

Description

  The present invention relates to a method for producing amorphized cellulose.

Cellulose obtained by pulverizing cellulose-containing raw materials such as pulp is used as industrial raw materials such as cellulose ether raw materials, cosmetics, foods, and biomass materials. As these industrial raw materials, cellulose having an amorphous cellulose crystal structure is particularly useful.
For example, a method is known in which sheet-like pulp is mechanically processed by a pulverizer to produce powdered pulp (see, for example, Patent Documents 1 and 2). However, these patent documents do not describe the crystallinity of cellulose.
Moreover, the method of processing a pulp mechanically with a grinder and reducing the crystallinity degree of a cellulose is known (for example, refer patent documents 3-6).
In Examples 1 and 4 of Patent Document 3, a method of treating sheet pulp with a vibrating ball mill or a twin screw extruder is disclosed.
In Examples 1 to 3 of Patent Document 4, a method of treating pulp with a ball mill is disclosed.
Examples 1 and 2 of Patent Document 5 disclose a method in which cellulose powder obtained by subjecting pulp to chemical treatment such as hydrolysis is treated with a ball mill or an airflow pulverizer.
Patent Document 6 discloses a method of treating pulp with a medium mill such as a vibration ball mill in a state where the pulp is dispersed in water.
However, these methods are not satisfactory in efficiency and productivity in reducing the crystallinity of cellulose.

JP-A-5-168969 JP 2001-354701 A JP 62-236801 A JP 2003-64184 A JP 2004-331918 A JP 2005-68140 A

  An object of this invention is to provide the manufacturing method excellent in productivity which can obtain the non-crystalline cellulose which reduced the cellulose I type crystallinity from the cellulose containing raw material efficiently.

The present inventors have found that the above-mentioned problem can be solved by performing treatment with a vibration mill filled with a rod using a specific cellulose-containing raw material as a starting raw material.
That is, the present invention is a method for producing non-crystalline cellulose from a cellulose-containing raw material having a cellulose I-type crystallinity of more than 33% represented by the following formula (1), and is obtained by removing water from the raw material. The cellulose I content is 20% by mass or more, and the cellulose-containing material is treated with a vibration mill filled with a rod to reduce the cellulose I-type crystallinity to 33% or less. The method for producing amorphous cellulose.
Cellulose type I crystallinity (%) = [(I _22.6 -I _18.5 ) / I _22.6 ] × 100 (1)
[I _22.6 is the diffraction intensity of the grating plane (002 plane) (diffraction angle 2θ = 22.6 °) in X-ray diffraction, and I _18.5 is the diffraction intensity of the amorphous portion (diffraction angle 2θ = 18.5 °). ]

  The method for producing amorphous cellulose of the present invention is excellent in productivity, and can efficiently obtain amorphous cellulose having a reduced cellulose I-type crystallinity.

The present invention is a method for producing non-crystalline cellulose from a cellulose-containing raw material having a cellulose I-type crystallinity of more than 33% represented by the following calculation formula (1), and is obtained by removing residual water from the raw material. Using a raw material having a cellulose content of 20% by mass or more in the component, and treating the cellulose-containing raw material with a vibration mill filled with a rod, the cellulose I-type crystallinity is reduced to 33% or less. A method for producing amorphous cellulose.
Hereinafter, the present invention will be described in detail. In the present specification, cellulose I type crystallinity may be simply referred to as “crystallinity”.

[Cellulose-containing raw material]
The cellulose-containing raw material used in the present invention has a cellulose content in the remaining components excluding water from the raw material of 20% by mass or more, preferably 40% by mass or more, more preferably 60% by mass or more.
The cellulose content used in the present invention means the total amount of cellulose and hemicellulose.
There is no restriction | limiting in particular in the said cellulose containing raw material, Various wood chips; Pulp, such as wood pulp manufactured from wood, the cotton linter pulp obtained from the fiber around cotton seeds; Newspaper, corrugated cardboard, magazine, fine paper, etc. Paper stalks; plant stalks and leaves such as rice straw and corn stalks; plant husks such as rice husks, palm husks and coconut husks. Of these, pulp is preferred.
In the case of commercially available pulp, the cellulose content in the remaining components excluding water is generally 75 to 99% by mass, and lignin and the like are included as other components.
The cellulose I type crystallinity of commercially available pulp is usually 60% or more.
The water content in the cellulose-containing raw material is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less. If the water content in the cellulose-containing raw material is 20% by mass or less, it can be easily pulverized, and the crystallinity can be easily reduced by the pulverization treatment described later.

[Cellulose type I crystallinity]
The non-crystalline cellulose produced by the present invention has a cellulose I type crystallinity reduced to 33% or less. Cellulose type I crystallinity is calculated by the Segal method from the diffraction intensity value by the X-ray diffraction method, and is defined by the following calculation formula (1).
Cellulose type I crystallinity (%) = [(I _22.6 -I _18.5 ) / I _22.6 ] × 100 (1)
[I _22.6 is the diffraction intensity of the grating plane (002 plane) (diffraction angle 2θ = 22.6 °) in X-ray diffraction, and I _18.5 is the diffraction intensity of the amorphous portion (diffraction angle 2θ = 18.5 °). ]
If the degree of crystallinity is 33% or less, the chemical reactivity of cellulose is improved. For example, in the production of cellulose ether, alkali celluloseization easily proceeds when an alkali is added, resulting in cellulose etherification reaction. The reaction conversion rate can be improved. From this viewpoint, the degree of crystallinity is preferably 20% or less, more preferably 10% or less, and particularly preferably 0% in which cellulose I-type crystals are not detected by analysis. The cellulose I type crystallinity defined by the calculation formula (1) may be a negative value in calculation, but in the case of a negative value, the cellulose I type crystallinity is 0%.
Here, the cellulose I type crystallinity is the ratio of the amount of crystal region of cellulose to the total amount. Cellulose type I is a crystalline form of natural cellulose. Cellulose type I crystallinity is also related to the physical and chemical properties of cellulose, and the higher the value, the higher the crystallinity of cellulose and the less non-crystalline parts. Flexibility, solubility in water and solvents, and chemical reactivity are reduced.

[Vibration mill]
In the present invention, the cellulose-containing raw material is pulverized by a vibration mill filled with a rod. By pulverizing with a vibration mill filled with a rod, the cellulose in the raw material can be efficiently amorphized.
As a vibration mill used in the present invention, a vibration mill manufactured by Chuo Kako Co., Ltd., a vibro mill manufactured by Eurus Techno Co., Ltd., a small vibration rod mill 1045 manufactured by Yoshida Manufacturing Co., Ltd., and a vibration cup mill P- manufactured by Fritsch Corporation of Germany. 9 type, a small vibration mill NB-O type manufactured by Nippon Ceramics Co., Ltd. can be used. The treatment method may be either batch type or continuous type.

〔rod〕
The rod filled in the vibration mill is a rod-shaped medium, and a rod having a cross section of a polygon such as a square or a hexagon, a circle or an ellipse can be used.
There is no restriction | limiting in particular as a material of a rod, For example, iron, stainless steel, an alumina, a zirconia, silicon carbide, silicon nitride, glass etc. are mentioned.
The outer diameter of the rod is preferably in the range of 0.5 to 200 mm, more preferably 1 to 100 mm, and still more preferably 5 to 50 mm. The length of the rod is not particularly limited as long as it is shorter than the length of the crusher container. If the size of the rod is in the above range, the desired crushing force can be obtained, and the cellulose can be efficiently amorphized without contamination of the cellulose-containing raw material by mixing fragments of the rod and the like. .
The filling range of the rod is preferably in a range of 10 to 97%, more preferably 15 to 95%, although a suitable range varies depending on the type of vibration mill. When the filling rate is within this range, the contact frequency between the cellulose and the rod is improved, and the grinding efficiency can be improved without hindering the movement of the medium. Here, the filling rate refers to the apparent volume of the rod relative to the volume of the vibration mill.
The treatment time of the vibration mill cannot be determined unconditionally depending on the type of vibration mill, the type of rod, the size, the filling rate, etc., but from the viewpoint of reducing the crystallinity, it is preferably 0.01 to 50 hr, more preferably 0.05-20 hr, more preferably 0.1-10 hr. Although processing temperature does not have a restriction | limiting in particular, From a viewpoint of preventing deterioration by a heat | fever, Preferably it is 5-250 degreeC, More preferably, it is 10-200 degreeC.

By the above-mentioned treatment method, amorphous cellulose having a cellulose I-type crystallinity of 33% or less can be efficiently obtained from the cellulose-containing raw material, and the pulverized product is fixed inside the mill during the vibration mill treatment. Without being dry.
The average particle size of the obtained amorphous cellulose is preferably 25 to 150 μm, more preferably 30 to 100 μm, from the viewpoint of chemical reactivity and handleability when the amorphous cellulose is used as an industrial raw material. In particular, when the average particle size is 25 μm or more, it is possible to suppress the occurrence of “maco” when the non-crystalline cellulose is brought into contact with a liquid such as water.

In addition, in the vibration mill treatment in the present invention, it is preferable to use a cellulose-containing raw material having a bulk density of 100 kg / m ³ or more from the viewpoint of more efficiently performing pulverization and amorphousization in a vibration mill filled with rods. 120 kg / m ³ or more is more preferable, and 150 kg / m ³ or more is more preferable. If this bulk density is 100 kg / m ³ or more, the cellulose-containing raw material has an appropriate volume, so that handleability is improved. Moreover, since the amount of raw materials charged into the vibration mill can be increased, the processing capacity is improved. On the other hand, the upper limit of the bulk density is preferably 500 kg / m ³ or less, more preferably 400 kg / m ³ or less, and still more preferably 350 kg / m ³ or less from the viewpoint of handleability and productivity. From these viewpoints, the bulk density is preferably 100 to 500 kg / m ³ , more preferably 120 to 400 kg / m ³ , and still more preferably 150 to 350 kg / m ³ .

  The cellulose-containing raw material supplied to the vibration mill preferably has an average particle size in the range of 0.01 to 1 mm from the viewpoint of efficiently dispersing the pulverized raw material in the vibration mill. If this average particle size is 1 mm or less, when supplying into the vibration mill, the pulverized raw material can be efficiently dispersed in the vibration mill and reach a predetermined particle size without requiring a long time. Can do. On the other hand, the lower limit of the average particle diameter is preferably 0.01 mm or more from the viewpoint of productivity. From these viewpoints, the average particle diameter is more preferably 0.01 to 0.7 mm, and even more preferably 0.05 to 0.5 mm. In addition, said average particle diameter and bulk density can be measured by the method as described in an Example.

[Pretreatment of vibration mill grinding]
In this invention, it is preferable to pre-process the cellulose containing raw material supplied to a vibration mill. For example, by processing the cellulose-containing raw material with an extruder, the bulk density and the average particle diameter of the cellulose-containing raw material can be set to the above-described preferable ranges.
It is preferable to coarsely pulverize the cellulose-containing raw material before feeding it into the extruder. The size of the coarsely pulverized product is preferably 1 to 50 mm, more preferably 1 to 30 mm. By roughly pulverizing to 1 to 50 mm, the extruder treatment can be performed efficiently and easily, and the load required for pulverization can be reduced.

  Examples of the method for coarsely pulverizing the cellulose-containing raw material include a method using a shredder or a rotary cutter. When a rotary cutter is used, the size of the coarsely pulverized product obtained can be controlled by changing the opening of the screen. The opening of the screen is preferably 1 to 50 mm, more preferably 1 to 30 mm. If the opening of the screen is 1 mm or more, a coarsely pulverized product having an appropriate bulkiness is obtained, and the handleability is improved. If the opening of the screen is 50 mm or less, it has an appropriate size as a pulverized raw material in the subsequent pulverization process, so that the load can be reduced.

By treating the cellulose-containing raw material, preferably the coarsely pulverized cellulose-containing raw material, with an extruder, a compressive shear force can be applied to break the crystal structure of the cellulose, whereby the cellulose-containing raw material can be powdered.
As a method of mechanically pulverizing by applying a compressive shear force, conventionally used impact type pulverizers such as a cutter mill, a hammer mill, a pin mill, etc., make the pulverized material fluffy and bulky. And the mass-based throughput is reduced. On the other hand, by using an extruder, a pulverized raw material having a desired average particle diameter and bulk density can be obtained, and handleability can be improved.

The extruder may be either a single-screw type or a twin-screw type, but a twin-screw extruder is preferable from the viewpoint of increasing the conveyance capability.
The twin screw extruder is an extruder in which two screws are rotatably inserted into a cylinder, and conventionally known ones can be used. The rotation directions of the two screws may be the same or opposite directions, but the rotation in the same direction is preferable from the viewpoint of increasing the conveyance capability.
The screw engagement conditions may be any of full-engagement, partial meshing, and non-meshing extruders. However, from the viewpoint of improving the processing capability, the complete meshing type and the partial meshing type are preferable.

As an extruder, it is preferable to provide what is called a kneading disk part in any part of a screw from a viewpoint of applying a strong compressive shear force.
The kneading disc part is composed of a plurality of kneading discs, which are combined continuously and shifted in a constant phase, for example by 90 °, with a narrow gap as the screw rotates. An extremely strong shearing force can be imparted by forcibly passing the cellulose-containing raw material. As a configuration of the screw, it is preferable that the kneading disk portion and the plurality of screw segments are alternately arranged. In the case of a twin screw extruder, it is preferable that the two screws have the same configuration.

As a processing method, the cellulose-containing raw material, preferably the coarsely pulverized cellulose-containing raw material, is charged into an extruder and continuously processed. The shear rate is preferably 10 sec ^-1 or more, more preferably 20~30000sec ^-1, 50~3000sec ^-1 is particularly preferred. If the shear rate is 10 sec ⁻¹ or more, pulverization proceeds effectively. Other treatment conditions are not particularly limited, and preferably a treatment temperature of 5 to 200 ° C.
Also, as the number of passes by the extruder, a sufficient effect can be obtained even with one pass, but from the viewpoint of reducing the crystallinity and the degree of polymerization of cellulose, if one pass is insufficient, perform two or more passes. Is preferred. Further, from the viewpoint of productivity, 1 to 10 passes is preferable. By repeating the pass, coarse particles are pulverized and a powdery cellulose-containing raw material with little variation in particle size can be obtained. When performing two or more passes, in consideration of production capacity, a plurality of extruders may be arranged in series for processing.

The measurement of (1) average particle diameter, (2) bulk density, (3) X-ray diffraction intensity, (4) moisture content, and (5) cellulose content of amorphous cellulose or cellulose-containing raw materials are described below. By the method.
(1) Measurement of average particle diameter The average particle diameter was measured using a laser diffraction / scattering particle size distribution measuring apparatus “LA-920” (manufactured by Horiba, Ltd.). The measurement conditions were ultrasonic treatment for 1 minute before particle size measurement, water was used as a dispersion medium during measurement, and the volume-based median diameter was measured at a temperature of 25 ° C.
(2) Measurement of bulk density The bulk density was measured using "Powder Tester" manufactured by Hosokawa Micron Corporation. The measurement was performed by vibrating the sieve, dropping the sample through a chute, receiving it in a specified container (capacity 100 mL), and measuring the mass of amorphous cellulose in the container.
(3) Measurement of X-ray diffraction intensity X-ray diffraction intensity was measured using the “Rigaku RINT 2500VC X-RAY diffractometer” manufactured by Rigaku Corporation under the following conditions, and based on the above formula (1), cellulose I The type crystallinity was calculated.
The measurement conditions were X-ray source: Cu / Kα-radiation, tube voltage: 40 kv, tube current: 120 mA, measurement range: 2θ = 5-45 °. The measurement sample was prepared by compressing a pellet having an area of 320 mm ² × thickness of 1 mm. The X-ray scan speed was measured at 10 ° / min.
(4) Measurement of moisture content The moisture content was measured at 150 ° C using an infrared moisture meter ("FD-610", manufactured by Kett Scientific Laboratory).
(5) Measurement of cellulose content The cellulose content is described in pages 1081 to 1082 of the Japan Analytical Chemistry Society, Analytical Chemistry Handbook (4th revised edition, published on November 30, 1991, Maruzen Co., Ltd.). This was measured by the holocellulose quantitative method.

Example 1
[Shredder treatment]
As a cellulose-containing raw material, sheet-like wood pulp [“Boreregard's“ Blue Bear Ultra Ether ”, 800 mm × 600 mm × 1.5 mm, crystallinity 81%, cellulose content (in the remaining components excluding water from the cellulose-containing raw material] 96 mass% and the water content of 7 mass%] was applied to a shredder (“MSX2000-IVP440F” manufactured by Meiko Shokai Co., Ltd.) to obtain a chip-like pulp of about 10 mm × 5 mm × 1.5 mm.
[Vibration mill treatment]
100 g of the obtained chip-like pulp was put into a vibration mill (manufactured by Chuo Kako Co., Ltd., “MB-1”, container total capacity 3.5 L), and as a rod, diameter 25 mm, length 218 mm, material stainless steel, cross section Sixteen rods having a circular shape were filled in a vibration mill (filling rate 49%), and the treatment was performed for 3 hours under the conditions of an amplitude of 8 mm and a circular rotation of 1200 cpm. The average particle size of the amorphous cellulose obtained after the vibration mill treatment was 80 μm. Moreover, the temperature at the time of completion | finish of the vibration mill process of the obtained amorphous cellulose was 85 degreeC by the heat_generation | fever accompanying a process.
After completion of the treatment, no pulp sticking matter was found on the wall or bottom of the vibration mill. The obtained amorphous cellulose was taken out from the vibration mill, the average particle size of the obtained amorphous cellulose was measured, and the crystallinity was calculated from the X-ray diffraction intensity. The results are shown in Table 1.

Example 2
(Extruder processing)
Chip-like pulp obtained by subjecting the same pulverized raw material as in Example 1 to the same shredder process as in Example 1 was charged into a twin-screw extruder (“EA-20” manufactured by Suehiro EPM Co., Ltd.) at 2 kg / hr, and sheared. One-pass processing was performed while flowing cooling water from the outside at a speed of 660 sec ⁻¹ , a screw rotation speed of 300 rpm. The twin-screw extruder is a fully meshing type co-rotating twin-screw extruder, and the screws arranged in two rows are combined with a screw portion having a screw diameter of 40 mm and 12 blocks alternately (90 °). The two screws have the same configuration. The temperature of the twin screw extruder was 30 to 70 ° C. due to heat generated by the treatment.
The pulp obtained after the extruder treatment had an average particle size of 121 μm and a bulk density of 254 kg / m ³ .
[Vibration mill treatment]
Next, using the pulp obtained after the extruder treatment, the vibration mill pulverization was performed in the same manner as in Example 1 except that the treatment time of the vibration mill was changed to 2 hr, to obtain amorphous cellulose. After completion of the pulverization, no fixed pulp was found on the wall or bottom of the vibration mill. The results are shown in Table 1.

Example 3
As a rod filled in the vibration mill, 13 rods with a diameter of 30 mm, a length of 218 mm, stainless steel, and a circular cross section were filled in the vibration mill (filling rate 57%), and the processing time of the vibration mill was changed to 1 hr. Amorphous cellulose was obtained by the same method and conditions as in Example 2 except for the above. The results are shown in Table 1.

Example 4
Amorphized cellulose was obtained by the same method and conditions as in Example 2 except that the number of rods filled in the vibration mill was changed to 14 and the vibration mill was filled (filling ratio: 62%). The results are shown in Table 1.

Example 5
Implemented except that the vibration mill was filled with a rod of 36 mm in diameter, 218 mm in length and made of stainless steel (filling rate 51%) and the processing time of the vibration mill was changed to 1 hr. Amorphized cellulose was obtained by the same method and conditions as in Example 2. The results are shown in Table 1.

Example 17
Implemented except that the vibration mill was filled into a vibration mill using 11 rods of diameter 30 mm, length 218 mm and material stainless steel (filling rate 48%), and the processing time of the vibration mill was changed to 3 hours. Amorphized cellulose was obtained by the same method and conditions as in Example 2. The water content of the pulp obtained after the extruder treatment when charged into the vibration mill was 4.1% by mass. The results are shown in Table 1.

Comparative Example 1
A shredder treatment was performed in the same manner as in Example 1 to obtain chip-like pulp. Next, 100 g of this chip-like pulp is put into a rolling mill (manufactured by Nippon Ceramic Science Co., Ltd., “Pot Mill ANZ-51S”, container volume 1.0 L, 10 mmφ zirconia balls are filled 1.8 kg, filling rate 53%). Then, the treatment was performed for 48 hours under the condition of a rotation speed of 100 rpm. The obtained pulp did not pulverize and remained almost chip-like. By the above method, the crystallinity was calculated from the X-ray diffraction intensity of the obtained pulp. The results are shown in Table 2.

Comparative Example 2
A shredder process was performed in the same manner as in Example 1 to obtain chip-like pulp. Next, 500 g of this chip-shaped pulp was put into a cutter mill (manufactured by Dalton Co., Ltd., “Power Mill P-02S type”), and subjected to a treatment for 0.5 hr under the condition of a rotational speed of 3000 rpm. The obtained pulverized product became cottony and could not obtain amorphous cellulose. The results are shown in Table 2.

Comparative Example 3
A shredder process was performed in the same manner as in Example 1 to obtain chip-like pulp. Next, 500 g of this chip-like pulp was put into a hammer mill ("SAMPLE-MILL" manufactured by Dalton Co., Ltd.) and treated for 0.5 hr under the condition of a rotational speed of 13500 rpm. The obtained pulverized product became cottony and could not obtain amorphous cellulose. The results are shown in Table 2.

Comparative Example 4
A shredder process was performed in the same manner as in Example 1 to obtain chip-like pulp. Next, 500 g of this chip-like pulp was put into a pin mill (Hosokawa Micron Co., Ltd., “Coloplex”), and treated for 0.25 hr under the condition of a rotational speed of 13000 rpm. The obtained pulverized product became cottony and could not obtain amorphous cellulose. The results are shown in Table 2.

Example 6
As a cellulose-containing raw material, cardboard [cellulose content: 84 mass%, moisture content: 7.2 mass%] was shredded in the same manner as in Example 1 to obtain chips of about 10 mm × 5 mm × 1.5 mm. .
Next, using the obtained chip-like cellulose-containing raw material (crystallinity 84%, bulk density 111 kg / m ³ ) 78 g as a rod filled in a vibration mill, a diameter of 30 mm, a length of 218 mm, a stainless steel material, a cross-sectional shape Is filled with 10 circular rods in a vibration mill (filling ratio 44%), and the vibration mill pulverization is performed in the same manner as in Example 1 except that the treatment time of the vibration mill is changed to 2 hr. Obtained. The results are shown in Table 3.

Example 7
Using a newspaper (cellulose content 83 mass%, moisture content 7.7 mass%) as the cellulose-containing raw material, the paper was shredded in the same manner as in Example 1 and roughly pulverized to about 10 mm × 5 mm.
Next, vibration mill pulverization was performed under the same conditions as in Example 6 using 71 g of coarsely pulverized cellulose-containing raw material (bulk density 45 kg / cm ² ) to obtain amorphous cellulose. The results are shown in Table 3.

Example 8
Example using 78 g of rice straw (bulk density 29 kg / m ³ , about 5 mm × 30 mm × 1 mm, crystallinity 54%, cellulose content 55 mass%, water content 8.0 mass%) as cellulose-containing raw material 6 was subjected to vibration mill pulverization under the same conditions as in Example 6 to obtain amorphous cellulose. The results are shown in Table 3.

Example 9
Using cellulose fiber (bulk density 30 kg / m ³ , about 5 cm × 5 cm × 5 mm, crystallinity 38%, cellulose content 63 mass%, water content 7.4 mass%) 40 g as a cellulose-containing raw material Vibration milling was performed in the same manner as in Example 6 to obtain amorphous cellulose, and the results are shown in Table 3.

Example 10
Using a rice husk (cellulose content 60 mass%, moisture content 13.6 mass%) as a cellulose-containing raw material, a biaxial extruder treatment was performed in the same manner as in Example 2 to obtain a powder. The crystallinity of the cellulose-containing raw material obtained after the twin-screw extruder treatment was 47%.
Next, Example 6 was used except that 100 g of the obtained powdery cellulose-containing raw material was used and the number of rods filled in the vibration mill was changed to 11 and the vibration mill was filled (filling rate 48%). Similarly, vibration milling was performed to obtain amorphous cellulose. The results are shown in Table 3.

Example 11
As the cellulose-containing raw material, the newspaper used in Example 7 was similarly shredded to form a chip. Next, using the obtained chip-shaped cellulose-containing raw material, a biaxial extruder treatment was performed in the same manner as in Example 2 to obtain a powder. The crystallinity of the cellulose-containing raw material obtained after the twin-screw extruder treatment was 56%.
Next, vibration mill pulverization was performed under the same conditions as in Example 10 to obtain amorphous cellulose. The results are shown in Table 3.

Example 12
In Example 11, a magazine (VoCE (Kodansha), With (Kodansha), MORE (Shueisha) mixture, cellulose content 60 mass% or more, moisture content 4.5 mass%) was used as the cellulose-containing raw material. In the same manner as in Example 11, a shredder process and a twin screw extruder process were performed to form a powder. The crystallinity of the cellulose-containing raw material obtained after the twin-screw extruder treatment was 67%. Next, vibration mill pulverization was performed under the same conditions as in Example 10 to obtain amorphous cellulose. The results are shown in Table 3.

Example 13
In Example 11, a shredder process and a twin screw extruder process were performed in the same manner as in Example 11 except that high-quality paper (cellulose content: 70% by mass or more, moisture content: 5.7% by mass) was used as the cellulose-containing raw material. To make a powder. The crystallinity of the cellulose-containing raw material obtained after the twin-screw extruder treatment was 67%. Next, vibration mill pulverization was performed under the same conditions as in Example 10 to obtain amorphous cellulose. The results are shown in Table 3.

Example 14
As a cellulose-containing raw material, 500 g of rice husk used in Example 10 was put into a hammer mill ("SAMPLE-MILL" manufactured by Dalton Co., Ltd.) and subjected to a treatment for 0.5 hr under the condition of a rotational speed of 13500 rpm. The obtained cellulose-containing raw material had a bulk density of 380 kg / m ³ and an average particle size of 148 μm. Next, vibration mill pulverization was performed under the same conditions as in Example 10 to obtain amorphous cellulose. The water content when the cellulose-containing raw material obtained after the hammer mill treatment was charged into a vibration mill was 8.6% by mass. The results are shown in Table 3.

Example 15
As a cellulose-containing raw material, 500 g of rice straw used in Example 8 was put into a hammer mill ("SAMPLE-MILL" manufactured by Dalton Co., Ltd.) and subjected to a treatment for 0.5 hr under the condition of a rotational speed of 13500 rpm. The obtained cellulose-containing raw material had a bulk density of 176 kg / m ³ and an average particle size of 148 μm. Next, vibration mill pulverization was performed under the same conditions as in Example 10 to obtain amorphous cellulose. The water content of the cellulose-containing raw material obtained after the hammer mill treatment when charged into the vibration mill was 6.5% by mass. The results are shown in Table 3.

Example 16
As a cellulose-containing raw material, a biaxial extruder treatment was carried out in the same manner as in Example 2 using 500 g of the palm fiber (cellulose content 63 mass%, moisture content 7.4 mass%) used in Example 9, and powdered I made it. The crystallinity of the cellulose-containing raw material obtained after the twin-screw extruder treatment was 42%.
Next, using the obtained powdery cellulose-containing raw material 40 g, vibration mill pulverization was performed in the same manner as in Example 6 except that the vibration mill was filled (filling ratio 44%) to obtain amorphous cellulose. . The results are shown in Table 3.

Comparative Example 5
Using the newspaper used in Example 7 as the cellulose-containing raw material, shredding treatment was similarly performed to obtain a chip-like cellulose-containing raw material. Next, 500 g of the obtained chip-like cellulose-containing raw material was put into a cutter mill ("Power Mill P-02S type" manufactured by Dalton Co., Ltd.), and subjected to a treatment for 1.5 hours under the condition of a rotational speed of 3000 rpm. The obtained pulverized product became cottony and could not obtain amorphous cellulose. The results are shown in Table 4.

Comparative Example 6
Using the cardboard used in Example 6 as the cellulose-containing material, shredding treatment was performed in the same manner as in Example 6 to obtain a chip-shaped cellulose-containing material. Next, a cutter mill treatment was performed under the same conditions as in Comparative Example 5. The obtained pulverized product became cottony and could not obtain amorphous cellulose. The results are shown in Table 4.

Comparative Examples 7 and 8
Comparative Example, except that the processing time was set at 0.5 hr using the rice straw used in Example 8 (Comparative Example 7) and the rice husk used in Example 10 (Comparative Example 8) as the cellulose-containing raw material. Cutter mill treatment was performed under the same conditions as in No. 5. In the obtained pulverized product, coarse particles were contained, and amorphous cellulose could not be obtained. The results are shown in Table 4.

Comparative Examples 9-11
As the cellulose-containing raw material, the newspaper used in Example 7 (Comparative Example 9), the corrugated cardboard used in Example 6 (Comparative Example 10) and the fine paper used in Example 13 (Comparative Example 10) were used in the same manner. A shredder treatment was performed and coarsely pulverized. Next, 500 g of this coarsely pulverized cellulose-containing raw material was put into a hammer mill ("SAMPLE-MILL" manufactured by Dalton Co., Ltd.) and treated for 0.5 hr under the condition of a rotational speed of 13500 rpm. The obtained pulverized product became cottony and could not obtain amorphous cellulose. The results are shown in Table 4.

  From Tables 1-4, the manufacturing method of the amorphous cellulose of Examples 1-17 can obtain the amorphous cellulose which reduced the crystallinity degree of the cellulose efficiently compared with Comparative Examples 1-11. It can be seen that it is excellent in productivity. In addition, when Example 1 and Comparative Example 1 are compared, the present invention using a rod as the medium of the vibration mill can efficiently obtain non-crystalline cellulose having a cellulose crystallinity reduced to 0%. I understand that I can do it. Furthermore, it turns out that the amorphized cellulose obtained in Examples 1-17 has a moderate average particle diameter compared with Comparative Examples 1-11, and is useful as raw materials, such as a cellulose ether.

  The method for producing amorphous cellulose of the present invention is excellent in productivity, and can efficiently obtain amorphous cellulose having a cellulose I-type crystallinity reduced to 33% or less. The obtained amorphized cellulose is particularly useful for cellulose ether raw materials, industrial raw materials such as cosmetics, foods, and biomass materials.

Claims (5)

A method for producing amorphous cellulose from a cellulose-containing raw material having a cellulose I-type crystallinity of more than 33% represented by the following formula (1), wherein the cellulose in the remaining components excluding water from the raw material A vibration mill in which a raw material having a content of 20% by mass or more is used, a bulk density of the cellulose-containing raw material is 100 to 500 kg / m ³ , and the cellulose-containing raw material is filled with a rod having an outer diameter of 5 to 50 mm. For 10 to 10 hours to reduce the cellulose I-type crystallinity to 33% or less.
Cellulose type I crystallinity (%) = [(I _22.6 -I _18.5 ) / I _22.6 ] × 100 (1)
[I _22.6 is the diffraction intensity of the lattice plane (002 plane) (diffraction angle 2θ = 22.6 °) in X-ray diffraction, and I _18.5 is the diffraction intensity of the amorphous portion (diffraction angle 2θ = 18.5 °). Show The average particle size of the cellulose-containing raw material is a 0.01 to 1 mm, the manufacturing method of amorphization cellulose according to claim 1. The method for producing amorphous cellulose according to claim 1 or 2, wherein the cellulose-containing raw material is pretreated with an extruder. The method for producing amorphous cellulose according to claim 3 , wherein the extruder is a twin screw extruder. The method for producing amorphous cellulose according to any one of claims 1 to 4 , wherein the cellulose-containing raw material is pulp.