JPH07102073A - Fine cellulose particle and its production - Google Patents

Abstract

PURPOSE:To improve the capability of fine celulose particles as a stabilizer for a suspension or emulsion and obtain the particles which give a smooth texture by grinding a cellulose material using both an ultra-high-pressure homogenizer and a medium mill. CONSTITUTION:A cellulose material such as wood pulp or purified linter is depolymerized by acid hydrolysis, etc., and purified to give a water-wetted cellulose having a degree of polymn. of 30-375. The resulting cellulose, as it is or after dried, is ground using both an ultra-high-pressure homogenizer and a medium mill to produce fine cellulose particles. High-viscosity fine cellulose particles are obtd. by using the mill first and then the homogenizer; lowviscosity particles, the homogenizer first and then the mill. Thus, the desired particles are obtd. which have particle sizes of 50% integrated volume of 8mum or lower and a viscosity of a 2-wt.% aq. dispersion at 20 deg.C of 50cP or higher.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention can stabilize suspension stabilizers, emulsion stabilizers, thickening stabilizers, etc. in a wide range of fields such as foods, pharmaceuticals, cosmetics, paints, ceramics, resins, catalysts and other industrial products. The present invention relates to a smooth and highly viscous fine cellulose which can be used as an agent, a texture-imparting agent, a cloudy agent, an abrasive, a dietary fiber, a fat and oil substitute, and a method for producing the same.

[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, it is difficult to obtain fine cellulose having a high viscosity by this method. Further, in this method, a metal made of 6 mm or less, usually 3 mm or less,
The cellulosic material is atomized by forcibly stirring small-diameter beads such as ceramics, but the bead movement is restricted due to the increase in cellulose concentration and the increase in viscosity as the atomization progresses. There is a problem that Further, the obtained finely divided cellulose has a large ratio of major axis to minor axis of individual particles, that is, an aspect ratio, and therefore lacks smoothness.

[0004]

[Problems to be Solved by the Invention] In recent years, as stabilizers for suspensions, dispersions, emulsifications and the like, ever-higher performance has been demanded,
In addition, as for the shape-retaining agent, dietary fiber material, oil and fat substitute, etc., a smooth material having a body feeling and not being rough is required. However, conventional techniques have not yielded fine cellulose that sufficiently satisfies these requirements.

The present invention solves these problems and can be used in a wide range of fields such as foods, pharmaceuticals, cosmetics, and industrial products, and has a high degree of stability such as suspension, dispersion and emulsification, a high degree of shape retention agent, It is an object of the present invention to provide a fine cellulose that can be used as a texture-imparting agent, a cloudy agent, an oil and fat substitute, and the like, and to provide a method for producing a fine cellulose that can be practically and efficiently produced.

[0006]

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, the particle size with an integrated volume of 50% is 8 μm or less, and the water dispersion of 2% by weight at 20 ° C.
It relates to fine cellulose having a viscosity of 50 cps or more. Further, the present invention relates to a method for producing the above-mentioned fine cellulose, characterized in that the cellulosic material is ground by using an ultrahigh pressure homogenizer and a medium mill in combination.

The fine cellulose of the present invention has an integrated volume of 50.
%, That is, the average particle diameter is required to be 8 μm or less. If the average particle size exceeds 8 μm, the ratio of coarse particles increases, and the graininess is felt. Further, if the average particle size exceeds 8 μm, it is not possible to obtain the highly viscous fine cellulose that is the object of the present invention. The lower limit of the average particle size is not particularly limited, but practical productivity can be achieved only up to about 0.3 μm in the average particle size.

In order to further enhance the effects of the present invention, it is preferable that the particle size with an integrated volume of 50% be 6 μm or less.
Further, the fine cellulose of the present invention needs to be 50 cps or more when the viscosity of a 2% by weight aqueous dispersion at 20 ° C. is used as an index. When the viscosity is less than 50 cps, the viscosity is insufficient, and when it is used as a thickening stabilizer, a texture-imparting agent, an oil and fat substitute, etc., a high addition amount is required to impart sufficient viscosity and a body feeling.

If the viscosity of the fine cellulose is too high, the grinding concentration cannot be increased during production, making it difficult to handle even during use, and depending on the application,
There are inconveniences such as the limited amount of addition. Therefore,
The preferred viscosity range of fine cellulose is 50 to 500 c
ps. In addition, the fine cellulose of the present invention has a rounded particle shape in which the ratio of the major axis to the minor axis of the particles constituting the fine cellulose, that is, the aspect ratio is small and has a rounded shape, and the proportion of particles having a particle size of 1 μm or less increases. are doing. Aspect ratio is preferably 3 or less, 1μ
The proportion of particles of m or less increases with the progress of miniaturization,
For example, when the average particle diameter is 4 μm or less, it is 15% or more.

Further, the fine cellulose of the present invention is appropriately mixed with water-soluble gums such as xanthan gum, karaya gum, carrageenan, pectin and sodium fibrin glycolate, and hydrophilic substances such as starch hydrolysates and dextrins. It doesn't matter. Also, two or more of these may be added and blended. This improves performance such as smoothness and stability.

On the other hand, in the prior art as described in Japanese Patent Publication No. 62-30220, microcrystalline cellulose is repeatedly treated by a homogenizer for high pressure,
A high-viscosity microcrystalline cellulose suspension is obtained. For example, the suspension obtained in Example 1 of the publication is 580c.
It shows a viscosity as high as ps (2 wt% solid content concentration). In this case, although there is no description regarding the particle size, microcrystalline cellulose “Avicel” <registered trademark> F
As a result of a confirmation test using D-101 (manufactured by Asahi Kasei Co., Ltd.), it was difficult to reduce the size to 8 μm or less. Further, JP-A-3-163135 discloses finely divided cellulose having a cumulative volume of 50% and a particle diameter of 0.3 to 6 μm.
It is not possible to obtain a finely divided cellulose having a viscosity of cps or more. In addition, most of the micronized cellulose particles have an aspect ratio of 5 to 10, and therefore have a unique stimulus.

As described above, the fine cellulose of the present invention is
It is characterized by achieving fineness and high viscosity, which cannot be obtained by conventional techniques, and having a small aspect ratio in the particle shape and its distribution and increasing the proportion of particles of 1 μm or less. Therefore, in applications such as thickening stabilizers, texture imparting agents, dietary fiber, fats and oils substitutes, improving the texture,
It gives a smooth texture with a good appearance and is effective as a body-imparting agent that gives a soft gel feeling with a small amount of addition. Further, since the proportion of fine particles of 1 μm or less is increased and the colloidal characteristics are improved, a suspension stabilizer,
In applications such as emulsion stabilizers and cloudy agents, it is possible to improve performance such as long-term stability.

The fine cellulose of the present invention is obtained by grinding a cellulosic material using an ultrahigh pressure homogenizer and a medium mill in combination. As the cellulosic material to be refined, an average degree of polymerization obtained by depolymerizing the cellulosic material such as wood pulp and refined linter by acid hydrolysis, alkaline oxidative decomposition, enzymatic decomposition, steam explosion decomposition, etc. Water-wet cellulose of 30 to 375 and cellulose obtained by drying this can be used. In addition, it is possible to use cellulose that is obtained by lightly hydrolyzing pulp or the like with a mineral acid or the like and then pulverizing the pulp.

Further, water-soluble gums such as xanthan gum, karaya gum, carrageenan, pectin, sodium fibrin glycolate, etc., hydrophilic substances such as starch hydrolysates, dextrins, etc. can be appropriately added to the cellulosic material. . These water-soluble gums and hydrophilic substances may be added to and blended with the finely divided cellulose after grinding. An 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 is preferably about 600 kg / cm ² or more. The commercially available devices are Nanomizer (manufactured by Nanomizer Co., Ltd.) and Microfluidizer (Microfluid).
ics company) or the like can be used.

The medium mill is a wet vibration mill, a wet planetary vibration mill, a wet ball mill, a wet roll mill, a wet coball mill, a wet bead mill, a wet paint shaker or the like. Among these, for example, a wet bead mill is made of metal,
Although a device such as a ceramic medium is contained in a container and wet-milled by forcibly stirring the medium, examples of commercially available devices include an apex mill (manufactured by Kotobuki Giken Kogyo Co., Ltd.) and a pearl mill (Ashizawa). For example, a product manufactured by Co., Ltd., a Dyno mill (manufactured by Shinmaru Enterprises Co., Ltd.) or the like can be used.

In the production method of the present invention, an ultrahigh pressure homogenizer and a medium mill are used in combination to miniaturize a cellulosic material. When the medium mill is used alone, it is effective in reducing the average particle size, but only a low viscosity can be obtained, and the practical milling concentration is about 13% in terms of solid content. On the other hand, the ultra-high pressure homogenizer has a slightly lower effect of reducing the particle size with an integrated volume of 50%, that is, the average particle size, as compared with the media mill, but the ratio of particles of 1 μm or less is high in the characteristics of the obtained fine cellulose. The feature is that a rounded particle shape with a small aspect ratio can be obtained and a high viscosity can be obtained. Further, the practical grinding concentration can be up to about 20% in terms of solid content. The fine cellulose of the present invention is obtained by using an ultrahigh pressure homogenizer and a medium mill together, and the features of each device can be utilized.

In particular, it has been found that a cellulosic material which has been subjected to a grinding treatment with a medium mill in advance has a significantly improved grindability in an ultrahigh pressure homogenizer and has a combined effect. This method is preferred for practically and efficiently producing fine cellulose having high viscosity and smaller average particle diameter. Also,
It was found that the viscosity of fine cellulose can be adjusted by the solid content concentration during grinding. That is, fine cellulose having a higher viscosity can be obtained by lowering the solid content concentration during grinding.

Further, by effectively using a medium mill and an ultrahigh pressure homogenizer together, it is possible to adjust the viscosity of fine cellulose within the scope of the present invention. In order to obtain fine cellulose having a high viscosity, for example, it is preferable to use a medium mill for the first pass crushing and use an ultrahigh pressure homogenizer after the second pass. Further, in order to obtain fine cellulose having a low viscosity, for example, it is preferable to use an ultrahigh pressure homogenizer in the first pass and a medium mill in the second and subsequent passes. In either case, a smooth fine cellulose having a small aspect ratio and a high proportion of particles of 1 μm or less can be obtained.

In the combined system, the selection of the front and rear devices and the number of passes to be set are determined from the viewpoints of the solid content concentration at the time of grinding, the particle size of the target fine cellulose, the viscosity and the economical efficiency. It can be arbitrarily determined. It is also effective to use hot water in grinding.
In the present invention, the concentration of solid content dispersed in water at the time of grinding is 2 to
It is 20%, preferably 5 to 15%. The obtained fine cellulose as it is, or appropriately diluted with an aqueous medium,
It can be dispersed and used.

The above-mentioned fine cellulose of the present invention is characterized in that the particle size in an integrated volume of 50% is 8 μm or less, and the viscosity of a 2% by weight aqueous dispersion at 20 ° C. is 50 cps or more. Thereby, in the fields of food, pharmaceuticals, cosmetics, industrial products, etc., suspension stabilizers, emulsion stabilizers, stabilizers such as thickening stabilizers, texture imparting agents, cloudy agents, abrasives,
It can be used as a substitute for dietary fiber, fats and oils, etc., and it becomes possible to obtain a product having improved texture, appearance, texture and stability.

Further, according to the manufacturing method of the present invention in which the ultra-high pressure homogenizer and the medium mill are used in combination, it becomes possible to miniaturize the cellulosic material with a practically small number of passes.
The particle size was measured using a HORIBA laser diffraction particle size distribution analyzer (LA-500, manufactured by Horiba, Ltd.), and the viscosity was measured using a B-type viscometer. The viscosity of a 2 wt% aqueous dispersion at 60 rpm was measured. Was measured.

[0022]

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

[0023]

Example 1 A 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 a cellulose dispersion having a solid content of 10%. Was prepared. This cellulose dispersion was subjected to a medium agitation wet pulverization device (Apex Mill, AM-1 type manufactured by Kotobuki Giken Kogyo Co., Ltd.) using zirconia beads having a diameter of 1 mmφ as a medium, a stirring blade rotation speed of 1800 rpm, and a supply amount of the cellulose dispersion. Crushing treatment was carried out by passing once under the condition of 0.4 l / min to obtain paste-like cellulose (first pass). This paste-like cellulose was passed twice through a high-pressure crushing device (Microfluidizer M-110Y manufactured by Microfluidics) under the condition of 1200 Kg / cm ² to obtain fine cellulose (2nd to 3rd passes). Table 1 shows the particle size and viscosity of this fine cellulose in an integrated volume of 50%.

[0024]

Example 2 Solid content 10 obtained in Example 1 as a raw material
% Cellulose Dispersion High Pressure Crusher (Microfl
uidics Microfluidizer M-610)
Then, it was passed once under the condition of 1200 Kg / cm ² to obtain fine cellulose (first pass). This fine cellulose dispersion was used as a medium with a medium agitation wet pulverizer (Apex mill, AM-1 type, manufactured by Kotobuki Giken Co., Ltd.) to have a diameter of 1 m.
Rotating speed of stirring blade 180 using mφ zirconia beads
0 rpm, supply amount of cellulose dispersion 0.4 l / min
Crushing treatment was carried out by passing it twice under the conditions described above to obtain fine cellulose (2nd to 3rd passes). Integrated volume of this fine cellulose 5
The particle size and viscosity of 0% are shown in Table 1.

[0025]

Example 3 A commercially available DP pulp was hydrolyzed to give a solid content of 6
% Cellulose was obtained in the same manner as in Example 1 except that the dispersion liquid was made of cellulose. Table 1 shows the particle size and viscosity of this fine cellulose in an integrated volume of 50%.

[0026]

Comparative Example 1 Solid content of 10 obtained in Example 1 as a raw material
% Cellulose Dispersion Medium Agitation Wet Grinding Device (Apex Mill, AM-1 Type, Kotobuki Giken Kogyo Co., Ltd.)
Then, using zirconia beads having a diameter of 1 mmφ as a medium, the mixture was crushed three times under the conditions of a stirring blade rotation speed of 1800 rpm and a cellulose dispersion supply rate of 0.4 l / min to obtain paste-like cellulose. Table 1 shows the particle size and viscosity of this cellulose in an integrated volume of 50%.

[0027]

Comparative Example 2 Solid content 10 obtained in Example 1 as a raw material
% Cellulose Dispersion Liquid for High Pressure Homogenizer (Gorinho
560 Kg / using a modifier (15M-8TA)
cm ²Under the conditions of 3 times, homogenize and paste
Of cellulose was obtained. 50% cumulative volume of this cellulose
Table 1 shows the particle size and viscosity of the.

[0028]

[Test Example 1] Example 1 and Comparative Example 1 showing almost the same particle size
For the sample of the second pass, the ratio of particles of 1 μm or less was obtained using a HORIBA laser diffraction particle size distribution analyzer (LA-700 type, manufactured by Horiba Ltd.). As a result, the 2-pass product of Example 1 was 29%, and Comparative Example 1
2 pass product is 15%, and it is understood that the fine cellulose of the present invention has a remarkably increased proportion of particles of 1 μm or less.

[0029]

[Test Example 2] 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 exhibits an elongated shape.
In addition, the sample of Comparative Example 2 has coarse particles but is coarse particles. As a result of a sensory test with the mouth and fingers of these samples, the fine cellulose of the present invention was smooth without roughness. On the other hand, the samples of Comparative Examples 1 and 2 had a rough texture and rough texture, which was in agreement with the observation result of the particle shape.

[0030]

[Table 1]

[0031]

EFFECTS OF THE INVENTION The fine cellulose of the present invention has a high viscosity, the proportion of particles of 1 μm or less is remarkably increased, and the particle shape is round and has a small aspect ratio. Therefore, the performance as a stabilizer such as suspension stability and emulsifying property is remarkably improved, and a smooth structure free from roughness is provided. Therefore, the fine cellulose of the present invention, food, pharmaceuticals, cosmetics, paints, ceramics, resins, suspension stabilizers in the industrial products, emulsion stabilizers,
It is effective in fields requiring uniform dispersibility and long-term stability such as thickening stabilizers and cloudy agents.
Furthermore, it is possible to exert an effect in a field where a smooth texture without roughness is required while imparting a body feeling such as a shape-retaining agent, a dietary fiber material, an oil and fat substitute, and expanding the range of use thereof.

For example, in the field of food,
Cocoa beverages, juice beverages, matcha beverages, powdered beverages and other favorite beverages, milk cocoa, milk coffee, lactic acid bacteria beverages, soy milk and other milky beverages, ice cream, soft ice cream, sherbet and other frozen desserts, puddings, jellies, Gel-like foods such as jams and water-sheeps, milkshakes, coffee whiteners, whipped cream, mayonnaise, dressings, spreads, sauces, soups, kneading,
Flower paste, cooked cans, spreads, liquid tube meal, kneading, filling and topping for bread and cakes, bean paste products, honzanto, fish paste products, bread and cakes, Japanese sweets, noodles, pasta, frozen dough, etc. Powdered fats and oils,
For powder flavors, powder soups, powder spices, cream powders, etc., suspension stabilizers, emulsion stabilizers, thickening stabilizers,
It can be used as a foam stabilizer, a cloudy agent, a texture-imparting agent, a fluidity improver, a shape-retaining agent, a water release inhibitor, a dough modifier, a powdering base, and a dietary fiber base in the above foods in general,
There are uses such as a low-calorie base for substituting fats and oils.

Claims (2)

[Claims] 1. A 50% cumulative volume particle size is 8 μm or less, and a 2% by weight aqueous dispersion has a viscosity of 50 c at 20 ° C.
Fine cellulose characterized by being ps or more. 2. The method for producing fine cellulose according to claim 1, wherein the cellulosic material is ground by using an ultrahigh pressure homogenizer and a medium mill in combination.