JPH07102074A - Method for converting cellulose material into minute particle - Google Patents

Abstract

PURPOSE:To efficiently convert a cellulose material into minute particles. CONSTITUTION:A cellulose material is converted into an aq. dispersion having a solid content of 1-20wt.% at a predispersion step and then subjected to a face-to-face collision in a minute orifice under a pressure of 600kg/cm<2> or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for making cellulosic material fine. That is, the present invention, foods, pharmaceuticals, cosmetics, paints, ceramics, resins, catalysts, in a wide range of other industrial products, suspension stabilizers, emulsion stabilizers, thickening stabilizers, etc. stabilizers, texture imparting agents, The present invention relates to a method for refining a cellulosic material that can be used as a cloudy agent, an abrasive, dietary fiber, an oil and fat substitute, and the like.

[0002]

2. Description of the Related Art Conventionally, various methods have been tried for making cellulose fine. For example, Japanese Examined Japanese Patent Publication Sho 62-3
Japanese Unexamined Patent Publication No. 0220 discloses a method of homogenizing a microcrystalline cellulose suspension with a homogenizer for high pressure, but it is necessary to repeat the treatment many times in order to sufficiently miniaturize the suspension, which is a practical method. It can not be said. In addition, JP-A-3-16
No. 3135 discloses that the particle size with an integrated volume of 50% is 0.3-
There is a disclosure of a method of atomizing 6 μm micronized cellulose and a cellulosic material by a media mill.

However, according to this method, the cellulosic material is atomized by forcibly stirring beads having a small particle diameter of 6 mm or less, usually 3 mm or less, such as metal or ceramic, and the cellulose concentration is increased. Alternatively, there is a problem that the movement of the beads is restricted due to an increase in viscosity with the progress of atomization, and the productivity is reduced. Further, there is a problem that abrasion occurs over time due to collision between the media and between the media and the stirring blades. Further, the obtained micronized cellulose has a large ratio of major axis to minor axis of individual particles, that is, an aspect ratio, and therefore lacks smoothness.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves these problems of the prior art and is a high-level stabilizer for suspension, dispersion, emulsification, etc., which can be used in a wide range of fields such as foods, pharmaceuticals, cosmetics, and industrial products. , A highly shape-retaining agent, a texture imparting agent, a cloudy agent, a fat-and-oil substitute, and the like.

[0005]

The inventor of the present invention has arrived at the present invention as a result of extensive research to solve these problems of the prior art. That is, according to the present invention, a cellulosic material is made into an aqueous dispersion having a solid content of 1 to 20% by weight in a preliminary dispersion step, and then a pressure of 600 kg is applied in a fine orifice.
The present invention relates to a method for micronizing a cellulosic material, which is characterized by causing face-to-face collision under a condition of not less than / cm ² .

As a cellulosic material to be subjected to micronization, cellulosic materials such as wood pulp and refined linter are depolymerized by acid hydrolysis, alkaline oxidative decomposition, enzymatic decomposition, steam explosion decomposition, etc., and then refined. Wet cellulose having an average degree of polymerization of 30 to 375 and cellulose obtained by drying this can be used. Further, a complex of this cellulose with water-soluble gums and / or starch decomposition products can be used. Further, pulp or the like is lightly hydrolyzed with a mineral acid or the like, and then crushed cellulose can be used.

Examples of commercially available cellulosic materials include cellulose powder, crystalline cellulose, and a complex of crystalline cellulose and water-soluble gums. To make the cellulosic material finer, it is necessary to disperse it homogeneously or to grind it as much as possible by preliminary dispersion. It has an average particle size of 25 μm or less, prevents clogging in the fine orifice, and is finer in the next step. In order to achieve this, the thickness is preferably 15 μm or less.

Various dispersing, emulsifying and grinding machines can be used as the preliminary dispersing machine. For example, propeller type dispersers, high speed mixers, homomixers, various mixers such as cutters, ball mills, mills such as colloid mills, dispersions represented by high pressure homogenizers, emulsifiers, kneaders, planetary mixers, extruders, etc. The kneading and grinding machines used can be used.

As a device for refining in the fine orifice following the preliminary dispersion step, for example, an ultrahigh pressure homogenizer is preferably used. The ultra-high pressure homogenizer is a device that grinds by shearing force due to accelerated high flow velocity, rapid pressure drop (cavitation), and impact force caused by face-to-face collision of particles with high flow velocity in a fine orifice. The pressure for miniaturization is about 600 Kg / cm
A pressure of ² or more is required, and a pressure of less than this is not practical because the miniaturization is insufficient. The commercially available devices are Nanomizer (manufactured by Nanomizer Co., Ltd.) and Microfluidizer (manufactured by Microfluidics).
Etc. can be used.

It is effective to use hot water for the preliminary dispersion and the dispersion by the finer. The concentration of the aqueous dispersion of the cellulosic material in micronization is 1 to 20% by weight in terms of solid content. If it is less than 1% by weight, it cannot be said to be practical, and if it exceeds 20% by weight, stable operability and miniaturization efficiency in the operation of the miniaturization apparatus are deteriorated.

The micronization method of the present invention is a method for practically and efficiently micronizing a cellulosic material without inclusion of impurities. The resulting microcellular material has a high proportion of particles of 1 μm or less and has a roundness. It is characterized in that particles having a small aspect ratio and having a smooth structure and a high viscosity can be obtained. Therefore, suspension stabilizers in a wide range of fields such as foods, pharmaceuticals, cosmetics, paints, ceramics, resins, catalysts and other industrial products.
It can be used as a stabilizer such as an emulsion stabilizer and a thickening stabilizer, a texture imparting agent, a cloudy agent, an abrasive, a dietary fiber, a fat and oil substitute, and the like. In addition, the measurement of particle size
A laser diffraction particle size distribution analyzer (LA-500 type,
HORIBA, Ltd.) and the average particle size is 5
The particle size is 0%. .

[0012]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

[0013]

Example 1 Commercially available DP pulp was shredded, hydrolyzed in 10% hydrochloric acid at 105 ° C. for 20 minutes to obtain an acid-insoluble residue, which was filtered, washed and purified, and then spray-dried to give a water content of 4.7%.
Of crystalline cellulose was obtained. The solid content of this crystalline cellulose was adjusted to 10% by weight, and preliminary dispersion was performed at 25 ° C. for 1 minute at 15,000 rpm with an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.). Average particle size of the pre-dispersion is 14.3 μm
Met. Then, the pre-dispersion liquid is mixed with a high-pressure crushing device (M
Microfluidizer M-110Y) manufactured by icrofluidics Co., Ltd. was passed 3 times under the condition of 1200 Kg / cm ² to obtain micronized crystalline cellulose. Table 1 shows the average particle size of this micronized crystalline cellulose.

[0014]

Example 2 A crystalline cellulose composite "Avicel"<registeredtrademark> RC-N81 (manufactured by Asahi Kasei Kogyo Co., Ltd.) was used as a solid content of 10% by weight, and the mixture was mixed with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) at 25 ° C. Preliminary dispersion was performed at 5000 rpm for 30 minutes. Average particle size of pre-dispersion is 12.5μ
It was m. Subsequently, this pre-dispersion liquid was applied to a high pressure crusher (Microfluidizer M-610 type manufactured by Microfluidics Co., Ltd.) under the condition of 1200 Kg / cm ² for 3 times.
It was passed once to obtain a micronized crystalline cellulose composite. The average particle size of this product is shown in Table 1.

[0015]

Example 3 A crystalline cellulose composite “Avicel” <registered trademark> RC-N30 (manufactured by Asahi Kasei Kogyo Co., Ltd.) was used as a solid content of 10% by weight, and the solid content was 60 ° C. with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). Preliminary dispersion was performed at 5000 rpm for 10 minutes. Average particle size of pre-dispersion is 10.0μ
It was m. Subsequently, this preliminary dispersion liquid was subjected to a high-pressure crushing device (Nanomizer LA-31 type manufactured by Nanomizer Co., Ltd.).
At 1200 Kg / cm ² for 3 times to obtain a micronized crystalline cellulose composite. Table 1 shows the average particle size of this product.
Shown in.

[0016]

Comparative Example 1 Crystalline cellulose "Avicel"<registeredtrademark> F according to the method of JP-B-62-30220, Example 1.
D-101 was homogenized. At this time FD-101
To a solid content of 2% by weight and 5,000 rpm at 25 ° C. with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.)
Preliminary dispersion for 1 minute was performed. The average particle size of the predispersion is 2
It was 6.1 μm. Then, using a homogenizer for high pressure (Gorlin homogenizer: 15M-8TA), the liquid temperature was adjusted to 25.
The mixture was charged at 0 ° C. and homogenized by three passes under the condition of 560 Kg / cm ² . The average particle size of the obtained homogenized crystalline cellulose is shown in Table 1.

[0017]

[Test Example 1] As a result of observing the shape of particles with a microscope, the samples of Examples 1 to 3 show a rounded shape.
On the other hand, the sample of Comparative Example 1 is slightly rounded but has coarse particles. As a result of a sensory test with the mouth and fingers of these samples, the micronized cellulose obtained by the method of the present invention was smooth without roughness. On the other hand, the sample of Comparative Example 1 has a rough texture,
Roughness was felt, which was consistent with the observation result of the particle shape.

[0018]

[Table 1]

[0019]

EFFECTS OF THE INVENTION By using the micronization method of the present invention, the cellulosic material can be miniaturized practically and efficiently without inclusion of impurities. Further, the micronized cellulosic material obtained by the method of the present invention has a feature that it has a smooth texture without roughness and a high viscosity can be obtained. Therefore, food, pharmaceuticals, cosmetics, paints,
Stabilizers such as suspension stabilizers, emulsion stabilizers, thickening stabilizers, texture imparting agents, cloudy agents, abrasives, dietary fibers, oil substitutes in a wide range of fields such as ceramics, resins, catalysts and other industrial products. It is possible to expand the range of use as well as exhibiting the effect.

Claims (1)

[Claims] 1. A cellulose material characterized in that an aqueous dispersion liquid having a solid content of 1 to 20% by weight is prepared in a preliminary dispersion step, and then face-to-face collision is carried out in a fine orifice under a pressure of 600 kg / cm ² or more. A method of refining system materials.