JP6921351B1 - Powdered cellulose, its use and manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide powdered cellulose which is hard to disintegrate when molded. SOLUTION: The powdered cellulose has an average particle size of 5 to 100 μm and a water dispersibility (BS) of more than 15.0% and 20.0% or less. [Selection diagram] None

Description

The present invention relates to powdered cellulose, its use and production method.

Powdered cellulose has characteristics such as viscosity thickening, emulsion stability, water retention, oil absorption, and shape retention. Therefore, powdered cellulose can be used as food additives, tablet excipients, dispersants, shape-retaining agents, water-retaining agents, filtration aids, fillers, additives for paints / adhesives, etc. in foods, pharmaceuticals, cosmetics, etc. , Building materials, ceramics, rubber, plastics, etc. are used in a wide range of fields. Among them, because of its high safety, it is widely used in applications such as food additives and tablet excipients.

There are roughly two methods for producing powdered cellulose, one is a production method using a chemical treatment and the other is a production method using a mechanical treatment. The production method using a chemical treatment is a production method in which a cellulose raw material is hydrolyzed with a mineral acid such as sulfuric acid or hydrochloric acid, and pulverized as necessary. Specifically, a method of obtaining powdered cellulose by acid hydrolysis with dilute acid for 20 to 45 minutes at a high temperature of 120 to 160 ° C. (Patent Document 1), 2.5 (hereinafter, the specification is abbreviated as N). There are a method of obtaining powdered cellulose by acid hydrolysis with hydrochloric acid for about 15 minutes (Patent Document 2) and a method of obtaining powdered cellulose by high-temperature treatment with hydrochloric acid aqueous solutions of various concentrations (Patent Document 3).

One of the properties required when powdered cellulose is used as a food additive or tablet excipient is that the molded product has good disintegration property. For example, Patent Document 4 describes the fluidity of powdered cellulose.

U.S. Pat. No. 3,954,727 U.S. Pat. No. 3,141,875 Japanese Unexamined Patent Publication No. 53-127553 Japanese Patent No. 5982874

However, each document does not particularly describe the physical characteristics of powdered cellulose and the disintegration property of the obtained molded product.

An object of the present invention is to provide powdered cellulose having good disintegration property when formed into a molded product.

The present invention provides the following [1] to [8].
[1] Powdered cellulose having an average particle size of 5 to 150 μm and a water dispersibility (BS) of more than 15.0% and 20.0% or less.
[2] The powdered cellulose according to [1], wherein the major axis / minor axis ratio is 3.5 to 8.0.
[3] Excipient containing powdered cellulose according to [1] or [2].
[4] A molded product containing the powdered cellulose according to [1] or [2].
[5] A food additive containing the powdered cellulose according to [1] or [2].
[6] A cosmetic additive containing the powdered cellulose according to [1] or [2].
[7] An industrial additive containing the powdered cellulose according to [1] or [2].
[8] The powder according to [1] or [2], which comprises at least an acid hydrolysis treatment of a cellulose raw material, a pretreatment for a pulverization treatment, and a pulverization treatment, and the pretreatment includes at least a drying treatment using an air flow dryer. Method for producing cellulose.

According to the present invention, it is possible to provide powdered cellulose having good disintegration property when it is formed into a molded product such as a tablet.

Hereinafter, the present invention will be described in detail according to the preferred embodiment thereof. In this specification, the notation of "AA to BB" shall indicate AA or more and BB or less.

[Powdered cellulose]
The powdered cellulose of the present invention preferably has the following physical properties, and usually has at least a predetermined average particle size and water dispersibility (BS) among the following physical properties.

<Dispersibility in water (BS)>
The dispersibility (BS) of powdered cellulose in water is usually 14.5% or more, or 15.0% or more, preferably 15.3% or more, and more preferably 15.5% or more. The upper limit is usually 20.0% or less, preferably 19.0% or less, and more preferably 18.5% or less. Therefore, the dispersibility in water (BS) is usually 14.5 or more and 20.0% or less, preferably 15.3 to 19.0%, and more preferably 15.5 to 18.5%. When the dispersibility in water is within the above range, good dispersibility such as uniform dispersion when a molded product prepared from powdered cellulose is administered into the body can be exhibited, and improvement in absorption efficiency can be expected.

The dispersibility in water is presumed to affect the shape of powdered cellulose, and comprehensively represents the physical characteristics of powdered cellulose (for example, particle shape (for example, spherical shape, rod shape, bent rod shape), degree of fibrillation). It can be said to be an index. When the dispersibility in water is within the above range, the molded product obtained from the powdered cellulose has an appropriate sedimentation property and also has a fiber bond due to fluffing (fibrillation) on the surface of the cellulose, so that it has good disintegration property. Can be shown.

The dispersibility in water can be measured under the following conditions. 15 mL of 0.5 wt% aqueous dispersion of powdered cellulose was stirred at 500 rpm for 30 seconds, the stirrer was quickly removed and then poured into a tubular glass cell with a diameter of 25 mm, and the height from the bottom of the measurement sample in the cell. The 16 mm position is irradiated with incident light having a wavelength of 880 nm. The backscattered light from the measurement sample is detected at a position of 135 ° with respect to the incident light, and the backscattered light intensity (%) 30 minutes after the start of measurement is measured. The measurement starts within 1 minute from the preparation of the measurement sample.

<Particle size distribution, average particle size, span of particle size distribution>
The particle size distribution of powdered cellulose is the particle size distribution (10% diameter, 50% diameter, 90% diameter, D.10, respectively) when the integrated value of the volume accumulation distribution is 10%, 50%, 90%, respectively. It can be expressed as D.50, D.90). In the present specification, the particle size distribution is a value obtained by wet measurement using a laser scattering method as a measurement principle.

The span of the particle size distribution is a numerical value indicating the breadth of the particle size distribution. It is presumed that it affects the shape of powdered cellulose, and in the present invention, it can be said to be an index that comprehensively represents the particle shape of powdered cellulose (spherical, rod-shaped, bent rod-shaped, etc.) and the state of fiber aggregation. Powdered cellulose having an appropriate range of particle size distribution span has an appropriate fiber length and fiber width, and is unlikely to disintegrate because the fibers are bonded to each other during molding.

The span of the particle size distribution can be determined by the D.I. 10, D. 50, D. Calculate by substituting 90 into the following equation (1).
Equation (1): Span of particle size distribution = ((D.90)-(D.10)) / (D.50)

-Wet measurement conditions-
In the present specification, the wet condition means a condition for measuring the particle size of a sample as it is. Wet conditions D. 10, D. 50, D. 90, the preferred range of span is as follows.
D. 10 is usually 5 μm or more, 10.0 μm or more, or 14.0 μm or more, preferably 15.0 μm or more, and more preferably 15.5 μm or more. The upper limit is usually 40.0 μm or less or 25.0 μm or less, preferably 24.0 μm or less, and more preferably 23.0 μm or less.
D. 50 (average particle size) is usually 5.0 μm or more, 10.0 μm or more, 20.0 μm or more, 30.0 or more, 40.0 μm or more or 45.0 μm or more, preferably 46.0 μm or more or 47.0 μm. As mentioned above, it is more preferably 48.0 μm or more (however, it is a value larger than D.10). As a result, it is possible to suppress an increase in the cohesiveness of the powdered cellulose and a decrease in the powder fluidity caused by the increase, and it is possible to suppress a deterioration in workability. The upper limit is usually 150.0 μm or less, 140.0 μm or less, 130.0 μm or less, 120 μm or less or 110.0 μm or less, preferably 100 μm or less, 95.0 μm or less or 90.0 μm or less, more preferably 85.0 μm or less. More preferably, it is 83.0 μm or less. As a result, a molded product having good disintegration property can be obtained.
D. 90 is usually 100.0 μm or more, 110.0 μm or more or 115.0 μm or more, preferably 120.0 μm or more, 125.0 μm or more or 130.0 μm or more, more preferably 135 μm or more, still more preferably 140.0 μm or more. (However, it is a value larger than D.50). The upper limit is 250.0 or less, 240.0 μm or less, or 230 μm or less, preferably 220 μm or less or 210 μm or less, more preferably 200 μm or less, still more preferably 195 μm or less.
The span of the particle size distribution is usually 1.5 or more, preferably 1.7 or more, more preferably 1.9 or more, and further preferably 2.0 or more. The upper limit is usually 4.0 or less, preferably 3.5 or less, and more preferably 3.1 or less.

-Wet measurement (with ultrasonic irradiation)-
In the present specification, the wet condition (with ultrasonic irradiation) refers to a condition in which the particle size is measured after the sample is subjected to ultrasonic irradiation after water addition. D. in the case of wet type (with ultrasonic waves). 10, D. 50, D. 90, the preferred range of span is as follows.
D. 10 is usually 1.0 μm or more, 3.0 μm or more or 5.0 μm or more, preferably 7.0 μm or more or 8.0 μm or more, more preferably 9.0 μm or more, still more preferably 10.0 μm or more. The upper limit is usually 20.0 μm or less or 18.0 μm or less, preferably 15.0 or less, and more preferably 13.0 μm or less.
D. 50 is usually 5 or more, 10.0 μm or more or 15.0 μm or more, preferably 17 μm or more, 18.0 μm or more or 20.0 μm or more, more preferably 23.0 μm or more or 25.0 μm or more, still more preferably 26. It is 0 μm or more (however, it is a value larger than D.10.). The upper limit is usually 70.0 μm or less, 60.0 μm or less or 50.0 μm or less, preferably 45.0 μm or less or 40.0 μm or less, more preferably 35.0 μm or less, still more preferably 31.0 μm or less.
D. 90 is usually 50.0 μm or more, 55.0 μm or more, or 60.0 μm or more, preferably 63 μm or more. It is 0 m or more, more preferably 65.0 μm or more, still more preferably 68 μm or more (however, it is a value larger than D.50). The upper limit is 180.0 μm or less or 160.0 μm or less, preferably 140.0 μm or less or 120.0 μm or less, more preferably 100.0 μm or less, still more preferably 90.0 μm or less.
The span of the particle size distribution is usually 1.5 or more, preferably 1.7 or more, more preferably 1.9 or more, and further preferably 2.0 or more. The upper limit is usually 3.0 or less, preferably 2.8 or less, and more preferably 2.6 or less.

-Dry measurement-
In the present specification, the dry measurement refers to a condition in which the particle size is measured as it is without adding water to the sample. D. in the case of dry measurement. 10, D. 50, D. 90, the preferred range of span is as follows.
D. 10 is usually 1.0 μm or more, 3.0 μm or more or 5.0 μm or more, preferably 7.0 μm or more or 9.0 μm or more, more preferably 12.0 μm or more, still more preferably 14.0 μm or more. The upper limit is usually 40.0 μm or less or 35.0 μm or less, preferably 30 μm or less, more preferably 25.0 μm or less, still more preferably 23.0 μm or less.
D. 50 is usually 5.0 μm or more, 10.0 μm or more or 15.0 μm or more, preferably 20.0 μm or more, 25.0 μm or more or 30.0 μm or more, more preferably 35.0 μm or more or 40.0 μm or more, and further. It is preferably 43.0 μm or more (however, it is a value larger than D.10.). The upper limit is usually 100.0 μm or less, 95.0 μm or less, or 93.0 μm or less, preferably 90.0 μm or less, and more preferably 85.0 μm or less.
D. 90 is usually 70.0 μm or more, 90.0 μm or more, or 100 μm. It is 0 m or more, preferably 110.0 μm or more, more preferably 120.0 μm or more, still more preferably 130.0 μm or more (however, it is a value larger than D.50). The upper limit is 260.0 μm or less or 250.0 μm or less, preferably 240.0 μm or less or 230.0 μm or less, and more preferably 220.0 μm or less.
The span of the particle size distribution is usually 1.5 or more, preferably 1.7 or more, more preferably 1.9 or more, and further preferably 2.0 or more. The upper limit is usually 9.0 or less, preferably 8.5 or less, and more preferably 8.0 or less.

By satisfying the above range, the specific surface area of contact between the tablet and water when tableted can be adjusted to an appropriate range, the tablet hardness can be maintained to some extent, and powdered cellulose having good disintegration property can be obtained. can.

<Major axis / minor axis ratio (L / D)>
The major axis / minor axis ratio (L / D) of the powdered cellulose is usually 3.5 to 7.0, preferably 3.5 to 6.5, and more preferably 4.0 to 6.0. be.

L / D is presumed to affect the shape of powdered cellulose, and can be said to be an index that comprehensively represents the state of powdered cellulose particles (spherical, rod-shaped, bent rod-shaped, etc.), fiber aggregation, and the like. When the L / D is in the above-mentioned preferable range, it has an appropriate fiber length and fiber width, and the fibers are bonded to each other during molding, so that the fibers are less likely to collapse.

L / D is a value calculated under the following conditions. Using an optical microscope, the powdered cellulose is observed at a magnification of 100 times, the L and D of 140 randomly selected powdered celluloses are measured, and the L / D of each is calculated. Of the calculated L / D, it is calculated as the average value of a total of 100 powdered celluloses excluding the values of 20 for each of the upper and lower parts. The major axis (L) means the maximum fiber width of the powdered cellulose observed with an optical microscope. The minor axis (D) means the minimum value orthogonal to the major axis of the fiber width of the powdered cellulose observed with an optical microscope. When the powdered cellulose has a bent structure, L is the maximum length of the fiber width in the bent state. L is usually 35 or more, preferably 40 or more, and more preferably 41 or more. The upper limit is usually 60 or less, preferably 55 or less, and more preferably 53 or less. D is usually 6 or more, preferably 7 or more, and more preferably 8 or more. The upper limit may be 15 or less, and is not particularly limited. It is preferable that L is within the above range together with L / D because the disintegration property is further improved. The L / D is measured by measuring the powder moisture content of the powdered cellulose with an infrared moisture meter (FD-720 type, 1 g, 105 ° C., manufactured by Kett Scientific Research Institute) of 3.0 to 4.0%. After confirming.

[Manufacturing method of powdered cellulose]
The method for producing powdered cellulose is not particularly limited as long as it is a method for obtaining powdered cellulose from a cellulose raw material, but for example, a method including at least a pulverization treatment can be mentioned, and powdered cellulose having few impurities can be easily obtained. , A method of further performing acid hydrolysis treatment is preferable.

<Cellulose raw material>
The cellulose raw material is usually naturally-derived cellulose, preferably pulp, and more preferably wood-derived pulp. Examples of wood-derived pulp include hardwood-derived pulp and softwood-derived pulp. Examples of the method for preparing wood-derived pulp include a method including treatment by a pulping method (melting method). Lignin, which is a coloring substance, is dissolved and removed by a treatment by a pulping method (melting method), and a pulp having a high whiteness can be obtained. Examples of the pulping method (melting method) include a sulfite cooking method, a kraft cooking method, a soda / quinone cooking method, and an organosolv cooking method, and kraft pulp is preferable from the environmental point of view.

In the pulp preparation method, it is preferable to further perform a bleaching treatment in addition to the pulping method (melting method). This gives pulp with a higher degree of whiteness. Examples of the bleaching treatment method include chlorine treatment (C), chlorine dioxide bleaching (D), alkali extraction (E), hypochlorite bleaching (H), and the like. Hydrogen peroxide bleaching (P), alkaline hydrogen peroxide treatment stage (Ep), alkaline hydrogen peroxide / oxygen treatment stage (Eop), ozone treatment (Z), chelate treatment (Q), and two or more of these treatments. A method of applying a combination can be mentioned. Examples of the combination (sequence) of two or more processes include D-E / P-D, C / D-E-HD, Z-E-D-PZ / D-Ep-D, and Z / D-. Ep-D-P, D-Ep-D, D-Ep-D-P, D-Ep-P-D, Z-Eop-DD, Z / D-Eop-D, Z / D-Eop- D-ED (“/” in the sequence means that the treatment before and after “/” is continuously performed without cleaning). The bleaching treatment is not limited to the above example, and may be a commonly used method. The bleached pulp is usually in a fluid state (fluid pulp). The whiteness of the pulp is preferably 80% or more based on ISO 2470.

<Acid hydrolysis treatment>
Examples of the acid used for the acid hydrolysis treatment include mineral acids such as hydrochloric acid, sulfuric acid and nitric acid. The acid concentration is not particularly limited, but is preferably lower than the acid concentration in the acid hydrolysis treatment of the conventional powdered cellulose production from the viewpoint of maintaining the degree of polymerization and whiteness, and is preferably 0.4 to 2.0 N. More preferably, 0.5 to 1.5 N is more preferable. When the acid concentration is less than 0.4 N, the depolymerization of cellulose by the acid is suppressed and the decrease in the degree of polymerization of cellulose can be reduced, but miniaturization may be difficult. On the other hand, if it exceeds 2.0 N, the depolymerization of cellulose proceeds and the miniaturization becomes easy, so that the powder fluidity is improved, but the tablet hardness is lowered as the degree of polymerization is lowered (disintegrated when molded). It may be easier to do). The reaction conditions for the acid hydrolysis treatment are not particularly limited, but the reaction temperature is usually 80 to 100 ° C., and the reaction time is usually 30 minutes to 3 hours.

Prior to the acid hydrolysis treatment, the cellulose raw material may be pretreated. For example, slurrying of the cellulose raw material (preparation of the dispersion liquid) and adjustment of the concentration of the cellulose raw material can be mentioned. The concentration of the cellulose raw material is usually 3 to 10% by weight (in terms of solid content) with respect to the dispersion liquid. When the cellulose raw material is bleached liquid pulp, it is usually treated to increase the pulp concentration before hydrolysis. A dehydrator such as a screw press or a belt filter may be used for adjusting (concentrating) the concentration of the cellulose raw material. The acid hydrolysis treatment may be performed on a slurry of a cellulose raw material, or may be performed on a sheet-shaped cellulose raw material. When the cellulose raw material is a dry sheet of pulp, the pulp is usually loosened and then acid hydrolyzed. When loosening the pulp, a crusher such as a roll crusher may be used.

<Neutralization / cleaning / desiccation / drying treatment>
After the hydrolysis treatment, the obtained treated product undergoes appropriate pretreatment before the pulverization treatment. Examples of the pretreatment include neutralization, washing, deliquescent, and drying treatment, and it is preferable to perform neutralization, washing, deliquessing, and drying treatment in this order. The neutralization treatment may be carried out by adding an alkaline agent. The deliquescent treatment is usually a solid-liquid separation treatment, and waste acid can be separated from the hydrolyzed product. Further, the hydrolyzate may undergo a drying (dehydration) treatment. Thereby, the solid content concentration can be adjusted, and the physical property value of the powdered cellulose can be easily controlled. The solid content concentration is usually adjusted to 15% or more, preferably 20% or more. For drying, it is preferable to use an air flow dryer. As a result, regardless of the mode of the processed product after hydrolysis, such as cake-like solid, slurry, and solution, high-speed hot air can be applied while dispersing these in the air flow, and the decompression effect inside the dryer is utilized. It can be dried instantly. In addition, since the time of contact with hot air is extremely short, the product temperature can be kept low, which is ideal for drying heat-sensitive products and products with a low melting point. The conditions for drying with an airflow dryer are not particularly limited and can be set as appropriate. An example is as follows. The outlet drying temperature is usually 80 to 180 ° C, preferably 90 ° C to 160 ° C. The amount of air supply is usually 150 to 350 m ³ / h, preferably 160 to 320 m ³ / h.
On the other hand, when a spray dryer is used, it is sprayed and instantly dried with hot air to produce granules. Therefore, it is often not suitable for drying solid or semi-solid objects with a small amount of water, and the particles are more likely to be exposed to high heat momentarily than drying with an airflow dryer, which may affect the product. Will be done.

<Crushing process>
The pulverization process is a process of mechanically pulverizing a processed product that has undergone a previous step. The rating treatment may be performed at the same time as the pulverization or after the pulverization.

Examples of the crusher include the following.
Cutting type mill: Mesh mill (manufactured by Horai Co., Ltd.), Atoms (manufactured by Yamamoto Hyakuma Seisakusho Co., Ltd.), Knife mill (manufactured by Palman Co., Ltd.), Cutter mill (manufactured by Tokyo Atomizer Manufacturing Co., Ltd.), CS Cutter (manufactured by Mitsui Mine Co., Ltd.) ), Rotary cutter mill (manufactured by Nara Kikai Seisakusho Co., Ltd.), turbo cutter (manufactured by Freund Sangyo Co., Ltd.), pulp crusher (manufactured by Mizuko Co., Ltd.), shredder (manufactured by Shinko Pantech Co., Ltd.), etc.
Hammer type mill: Joe crusher (manufactured by Makino Co., Ltd.), hammer crusher (manufactured by Makino Sangyo Co., Ltd.), and microparperizer (manufactured by Hosokawa Micron Co., Ltd.).
Impact type mill: Pulverizer (manufactured by Hosokawa Micron Co., Ltd.), Fine Impact Mill (manufactured by Hosokawa Micron Co., Ltd.), Supermicron Mill (manufactured by Hosokawa Micron Co., Ltd.), Inomizer (manufactured by Hosokawa Micron Co., Ltd.), Fine Mill (manufactured by Nippon Pneumatic Industries Co., Ltd.) ), CUM type centrifugal mill (manufactured by Mitsui Mine Co., Ltd.), Exceed Mill (manufactured by Makino Sangyo Co., Ltd.), Ultraplex (manufactured by Makino Sangyo Co., Ltd.), Contraplex (manufactured by Makino Sangyo Co., Ltd.), Coroplex (manufactured by Makino Sangyo Co., Ltd.) Company), Sample Mill (Seishin Co., Ltd.), Bantam Mill (Seishin Co., Ltd.), Atomizer (Seishin Co., Ltd.), Tornado Mill (Nikkiso Co., Ltd.), Neamill (Dalton Co., Ltd.), HT type fine grinding Machine (manufactured by Horai Co., Ltd.), Free crusher (manufactured by Nara Kikai Seisakusho Co., Ltd.), New Cosmomizer (manufactured by Nara Kikai Seisakusho Co., Ltd.), Turbo Mill (manufactured by Freund Sangyo Co., Ltd.), Gather Mill (manufactured by Nishimura Kikai Seisakusho Co., Ltd.) ), Spar powder mill (manufactured by Nishimura Kikai Seisakusho Co., Ltd.), blade mill (manufactured by Nisshin Engineering Co., Ltd.), super rotor (manufactured by Nisshin Engineering Co., Ltd.), Npa crusher (manufactured by Sansho Industry Co., Ltd.), Willey crusher (Manufactured by Sanki Seisakusho Co., Ltd.), Pulp crusher (manufactured by Mizuko Co., Ltd.), Jacobson pulverizer (manufactured by Shinko Pantech Co., Ltd.), and Universal Mill (manufactured by Tokuju Kosakusho Co., Ltd.).
Airflow type mill: CGS type jet mill (manufactured by Mitsui Mine Co., Ltd.), micron jet (manufactured by Hosokawa Micron Co., Ltd.), counter jet mill (manufactured by Hosokawa Micron Co., Ltd.), cross jet mill (manufactured by Kurimoto Iron Works Co., Ltd.), supersonic speed Jet mill (manufactured by Nippon Pneumatic Industries Co., Ltd.), current jet (manufactured by Nisshin Engineering Co., Ltd.), jet mill (manufactured by Sansho Industry Co., Ltd.), Ebara Jet Micronizer (manufactured by Ebara Corporation), Ebara Triad Jet (manufactured by Ebara Corporation), selenium mirror (manufactured by Masuko Sangyo Co., Ltd.), New Microsictomat (manufactured by Masuno Seisakusho Co., Ltd.), and Cryptron (manufactured by Kawasaki Heavy Industries, Ltd.).
Vertical roller mill: Vertical roller mill (manufactured by Shinion Co., Ltd.), Vertical roller mill (manufactured by Chefler Japan Co., Ltd.), Roller mill (manufactured by Kotobuki Engineering & Research Co., Ltd.), VX mill (manufactured by Kurimoto Iron Works Co., Ltd.), KVM type vertical mill (EarthTechnica Co., Ltd.) and IS mill (IHI Plant Engineering Co., Ltd.).
Among these, Jaw Crusher (manufactured by Makino Co., Ltd.), Pulverizer (manufactured by Hosokawa Micron Co., Ltd.), Supermicron Mill (manufactured by Hosokawa Micron Co., Ltd.), Tornado Mill (manufactured by Nikkiso Co., Ltd.), Freedom Crusher (manufactured by Nara Kikai Seisakusho Co., Ltd.), turbo mill (manufactured by Freund Sangyo Co., Ltd.), spar powder mill (manufactured by Nishimura Kikai Seisakusho Co., Ltd.), blade mill (manufactured by Nisshin Engineering Co., Ltd.), supersonic jet mill (Nippon New) Matic Industry Co., Ltd.) or Current Jet (Nisshin Engineering Co., Ltd.) is preferable.

The conditions of the pulverization treatment or the classification treatment performed as necessary can be appropriately set so as to obtain the desired powdered cellulose. For example, the treatment conditions can be adjusted with reference to a calibration curve prepared from the pulverization conditions (for example, treatment time, input amount) and the desired physical properties of the powdered cellulose.

At the time of the pulverization treatment, at least one other component (for example, an organic component or an inorganic component) may be subjected to the pulverization treatment together with the acid hydrolyzed product, if necessary. Thereby, the functionality can be imparted or improved to the powdered cellulose. As for the blending amount of other components, an appropriate amount may be appropriately selected.

In the production of powdered cellulose, chemical treatment may be carried out if necessary. As the chemical treatment, a treatment that does not significantly impair the degree of polymerization of the cellulose raw material can be appropriately selected. The timing of the chemical treatment includes, for example, before the acid hydrolysis treatment, at the same time as the pulverization treatment, and the like, but is not particularly limited.

[Use of powdered cellulose]
Powdered cellulose can be used as an excipient for molded articles. As a result, the molded product can exhibit good disintegration property, and the molded product containing powdered cellulose together with the active ingredient can exhibit good sustained release property. Examples of the dosage form of the molded product include tablets.

Powdered cellulose can be used as a food additive. Thereby, the physical characteristics of the food can be improved or the quality can be improved. Foods include, for example, shredded cheese, fried products, bread crumbs, ham and sausage casings and their pickle liquids, chicken salads, powdered seasonings, paste products, artificial rice, gummy products, soups, hamburgers, dumplings, baked goods, Examples include processed foods such as soft cream, fried chicken, bread crumbs, donuts, and whipped cream.

Other uses of powdered cellulose include, for example, sanitary products / cosmetic additives (eg, for facial cleansers, dentifrices, foundations), industrial additives (eg, for resins such as polypropylene, phenolic resins, melamine resins). , Filter aids (eg, rare metals, for foods), paint / adhesive additives (eg, for urethane paints), feeds (eg, pet foods, fishing baits).

Hereinafter, the present invention will be specifically shown with reference to examples, but the present application is, of course, not limited to such examples. The test method in the examples of the present application is shown below. Unless otherwise specified, the method for measuring the physical property value or the like is the measurement method described above.

<Tablet hardness>
Tablets made of 100% powdered cellulose were prepared as follows. 0.3 g of a sample was placed in a mortar (manufactured by Ichihashi Seiki Co., Ltd., diameter 8 mm) and compressed with a pestle (manufactured by Ichihashi Seiki Co., Ltd.) having a diameter of 8 mm. 100% powdered cellulose was compressed at 40 MPa, and the stress was maintained for 10 seconds to prepare tablets. As the compressor, HANDTAB-100 manufactured by Enapak Co., Ltd. was used.

The load when the prepared tablet was broken was measured using a palm gel hardness tester (manufactured by Freund Sangyo Co., Ltd., MT50 type). The load was applied in the diametrical direction of the tablet. It was calculated by the average value of 5 samples.

<Tablet disintegration>
Tablets made of 100% powdered cellulose were prepared as follows. 0.3 g of a sample was placed in a mortar (manufactured by Ichihashi Seiki Co., Ltd., diameter 8 mm) and compressed with a pestle (manufactured by Ichihashi Seiki Co., Ltd.) having a diameter of 8 mm. 100% powdered cellulose was compressed at 5 MPa, and the stress was maintained for 10 seconds to prepare tablets (the compressor used was HANDTAB-100 manufactured by Enapac).

The prepared tablet was placed in a test tube, and 20 ml of pure water was added. After vibrating with a vibrator (manufactured by Advantech Toyo Co., Ltd., shaker TBK type) for 3 hours, the residue was collected by passing through 75 μm (JIS standard Z8801 wire). The residue was dried at 105 ° C., the weight was determined, and the ratio to the weight of the prepared tablet was determined. The measurement was performed three times, and the average value was calculated. It can be judged that the tablet disintegration property is good when it is 40% or less, slightly good when it is more than 40% and 65% or less, and bad when it is more than 65%.

<Dispersibility in water (BS)>
The powdered cellulose was adjusted to a concentration of 0.5% by weight with pure water, and the mixture was stirred under the condition of 500 rpm for 30 seconds to prepare a measurement sample. After quickly removing the stir bar, 15 mL of the prepared measurement sample is poured into a tubular glass cell having a diameter of 25 mm, and incident light having a wavelength of 880 nm is emitted at a position 16 mm in height from the bottom of the measurement sample in the cell. Irradiated. The backscattered light intensity (%) was measured by detecting the backscattered light from the measurement sample at a position of 135 ° with respect to the incident light. The measurement was started within 1 minute from the preparation of the measurement sample. As a device for measuring the backscattered light intensity of the measurement sample, "Tabiscan Lab" manufactured by Eiko Seiki Co., Ltd. was used.

<Particle size distribution, average particle size, span of particle size distribution>
A laser diffraction type particle size distribution measuring device (Master Sizar 3000, Malvern PANalytical Division, Spectris) was used. The particle size distribution was measured by dry measurement, wet measurement (with ultrasonic irradiation), and wet measurement (without ultrasonic irradiation) using the laser scattering method as the measurement principle. When the particle size distribution is expressed as a volume accumulation distribution, the integrated values of the volume accumulation distribution are 10%, 50%, and 90%, respectively. 10, D. 50, D. It was set to 90. Wet (without ultrasonic irradiation) D. 50 was defined as the average particle size. Further, the span of the particle size distribution was calculated by the above formula (1).

The dry measurement was carried out under the following conditions by adding a sample into the supply port so that the scattering intensity was less than 1%.
・ Distributed unit: Aero5
・ Air pressure: 2 bar
・ Feed rate: 25

The wet measurement was carried out by adding a sample to the measuring part in water stirred at 3500 rpm so that the scattering intensity was about 10%. When irradiating ultrasonic waves, wet measurement was performed after applying ultrasonic waves to a sample in water based on the following conditions.
・ Mode: Continuous ・ Strength: 100%
・ Time: 600 seconds

The particle size distribution was analyzed under the following conditions under all measurement conditions.
・ Analysis: General purpose ・ Analysis sensitivity: Emphasis ・ Light scattering model: Mie theory

<Major axis (L), minor axis (D), major axis minor axis ratio (L / D)>
1 g of powdered cellulose was classified with a JIS test sieve (manufactured by Tokyo Screen Co., Ltd .: 75 μm), and an observation sample was prepared. Using an optical microscope, the observation sample was observed at a magnification of 100 times, and the major axis (L) and minor axis (D) of 140 randomly selected powdered celluloses were measured, and the major axis / minor axis of each was measured. The ratio (L / D) was calculated. L represents the maximum diameter and D2 represents the minimum diameter. Of the calculated major axis / minor axis ratio (L / D), it was calculated as the average value of a total of 100 powdered celluloses excluding the upper and lower 20 values.

<Preparation of powdered cellulose>
<Example 1>
Chlorine-free bleached pulp was hydrolyzed at 95 ° C. for 2 hours at a pulp concentration of 5.5% and a hydrochloric acid concentration of 1.2 N. After the hydrolysis reaction was completed, the mixture was neutralized with sodium hydroxide, washed with industrial water, and then drained. This is dehydrated so that the solid content becomes 25% or more, and ^{dried by blowing air with an air flow dryer at an outlet drying temperature of 100 ° C. and an air supply amount of 270 m 3} / h for 1 hour to obtain acid-hydrogenated pulp. rice field. The obtained acid-hydrolyzed pulp is mechanically appropriately pulverized and classified using a hammer mill (Micropalperizer AP-S type manufactured by Hosokawa Micron) to obtain powdered cellulose having an average particle size of 50.2 μm. Obtained.

<Example 2>
The same operation as in Example 1 was carried out except that the air supply amount of the air flow dryer was set to 180 m ³ / h to obtain powdered cellulose having an average particle size of 61.3 μm.

<Example 3>
The same operation as in Example 1 was carried out except that the outlet drying temperature of the airflow dryer was 150 ° C. and the air supply amount was 180 m ³ / h to obtain powdered cellulose having an average particle size of 80.3 μm.

<Example 4>
The same operation as in Example 1 was carried out except that the outlet drying temperature of the air flow dryer was 80 ° C. and the air supply amount was 270 m ³ / h to obtain powdered cellulose having an average particle size of 49.8 μm.

<Example 5>
The same operation as in Example 1 was carried out except that the outlet drying temperature of the airflow dryer was 100 ° C. and the air supply amount was 310 m ³ / h to obtain powdered cellulose having an average particle size of 82.2 μm.

<Example 6>
The same operation as in Example 1 was carried out except that the outlet drying temperature of the air flow dryer was 150 ° C. and the air supply amount was 270 m ³ / h to obtain powdered cellulose having an average particle size of 63.2 μm.

<Comparative example 1>
Chlorine-free bleached pulp was hydrolyzed at 95 ° C. for 2 hours at a pulp concentration of 5.5% and a hydrochloric acid concentration of 0.15 N. After the hydrolysis reaction was completed, the mixture was neutralized with sodium hydroxide, washed with industrial water, and then drained. This was dehydrated so that the solid content was 25% or more. The dehydrated product was kneaded with a planetar mixer (manufactured by Inoue Seisakusho) and air-dried with an explosion-proof air blower for about 1 day under a temperature condition of 60 ° C. to obtain acid-hydrolyzed pulp. The obtained acid-hydrolyzed pulp is mechanically appropriately pulverized and classified using a hammer mill (AP-S type manufactured by Hosokawa Micron Co., Ltd.), and powdered cellulose having an average particle size of 42.3 μm (Comparative Example 1). Got

<Comparative example 2>
Chlorine-free bleached pulp was hydrolyzed at 95 ° C. for 2 hours at a pulp concentration of 5.5% and a hydrochloric acid concentration of 0.30 N. After the hydrolysis reaction was completed, the mixture was neutralized with sodium hydroxide, washed with industrial water, and then drained. This was dehydrated so that the solid content was 50% or more. The dehydrated product was kneaded with a planetar mixer (manufactured by Inoue Seisakusho) and air-dried with an explosion-proof air blower for about 1 day under a temperature condition of 60 ° C. to obtain acid-hydrolyzed pulp. The obtained acid-hydrolyzed pulp is mechanically appropriately pulverized and classified using a hammer mill (AP-S type manufactured by Hosokawa Micron Co., Ltd.), and powdered cellulose having an average particle size of 31.1 μm (Comparative Example 2). Got

Table 1 shows the physical characteristics and measured values of each sample.

As is clear from Table 1, the powdered celluloses of Comparative Examples 1 and 2 had a dispersibility in water of 15% or less and were inferior in tablet disintegration property, whereas the powdered celluloses of Examples 1 to 6 had a dispersibility in water. In each case, the dispersibility in water was relatively high, more than 15% and 20% or less, and the tablet disintegration property was good. As a result, the powdered cellulose of the present invention has good disintegration property when it is formed into a molded product such as a tablet, and when it is administered into the body, it can exhibit good dispersibility such as being evenly dispersed, and the absorption efficiency is high. It shows that improvement can be expected.

Claims (7)

When the average particle size is 5 to 150 μm, the dispersibility in water (BS) is more than 15.0% and 20.0% or less , and the integrated value of the volume accumulation distribution is 90% in the wet measurement. Powdered cellulose having a particle size distribution of 100 μm or more. The powdered cellulose according to claim 1, wherein the major axis / minor axis ratio is 3.5 to 8.0. An excipient containing powdered cellulose according to claim 1 or 2. A molded product containing the powdered cellulose according to claim 1 or 2. A food additive comprising the powdered cellulose according to claim 1 or 2. A cosmetic additive comprising the powdered cellulose according to claim 1 or 2. An industrial additive comprising the powdered cellulose according to claim 1 or 2.