JP6845685B2 - Method for producing disintegrating particles - Google Patents

Description

The present invention relates to a method for producing disintegrating particles in which particles disintegrate as the concentration of water-soluble salts decreases during washing or rinsing.

A skin cleanser containing particles has a feature of being able to remove excess keratin (dirt), skin grooves, sebum that has entered pores, dirt, etc., which are difficult to remove with a normal skin cleanser in physical cleansing. In addition, a comfortable massage feeling can be obtained by an appropriate physical stimulation of the particles.

As the particles used in the skin cleansing agent, particles that become fine particles or disintegrate particles during washing or rinsing are used from the viewpoint of skin irritation and usability. For example, a water-insoluble inorganic substance powder and / or a water-insoluble organic polymer substance powder is mixed with one or more types of cured oil powder having a melting point of 50 ° C. or higher, and this is mixed with a water-soluble binder. After granulating by the stirring granulation method, the dried particles are heat-treated so that the cured oil powder contained in the particles is melted, and cooled to obtain an external preparation for skin. Scrub granules for compounding (Patent Document 1), primary particles in which at least a part is water-insoluble, are charged into a stirring and rolling granulator equipped with a jacket in advance, and the jacket temperature is controlled to 15 to 25 ° C. for preliminary stirring. Disintegrant particles (Patent Document 2) and the like which have been mixed and then stirred, rolled and granulated using a salt-sensitive binder solution having a viscosity of 0.5 to 8.0 Pa · s have been reported.

Japanese Unexamined Patent Publication No. 6-271417 Japanese Unexamined Patent Publication No. 2001-293354

In Patent Document 2, an aqueous polyvinyl alcohol solution is used as one of the salt-sensitive binder solutions. According to the research of the present inventor, polyvinyl alcohol is excellent in that it enhances the storage stability of disintegrating particles in a cleaning agent product, while facilitating disintegration during cleaning and rinsing.
However, in the method for producing disintegrating particles by a stirring rolling granulator using a conventional polyvinyl alcohol aqueous solution, particles other than disintegrating particles having a desired particle size distribution, particularly particles having a small particle size, are simultaneously produced. It turned out that many were manufactured. Granules with a small particle size tend to impair physical cleanability and massage feeling.
Therefore, an object of the present invention is to provide a method capable of efficiently producing disintegrating particles having a desired particle size distribution.

As a result of diligent studies in view of the above problems, the present inventor agitated, rolled and granulated the primary particles using a polyvinyl alcohol aqueous solution when producing disintegrating particles from primary particles that were at least partially water-insoluble. Next, it was found that by drying with a fluidized layer dryer at a predetermined air velocity, it is possible to suppress the formation of particles having a small particle size and efficiently obtain disintegrating particles having a desired particle size distribution.

That is, the present invention was obtained in (A) a step of stirring, rolling and granulating using an aqueous solution of polyvinyl alcohol or a derivative thereof, and (B) step (A). The present invention provides a method for producing disintegrating particles, which comprises a step of drying a fluidized bed at a wind speed of 0.4 to 1.2 m / s.

According to the present invention, it is possible to suppress the formation of particles having a small particle size and efficiently obtain disintegrating particles having a desired particle size distribution. These disintegrating particles are excellent in physical cleansing property and massage feeling, and easily disintegrate during washing and rinsing, so that they are useful as raw materials for skin cleansers and the like.

The method for producing disintegrating particles of the present invention includes (A) a step of stirring, rolling and granulating primary particles, which are at least partially water-insoluble, using an aqueous solution of polyvinyl alcohol or a derivative thereof, and (B) a step (B). This is a method including a step of drying a fluidized bed at a wind speed of 0.4 to 1.2 m / s for the granulated product obtained in A).

[Step (A)]
This step is a step of stirring, rolling and granulating primary particles, which are at least partially water-insoluble, using an aqueous solution of polyvinyl alcohol or a derivative thereof.
In the present specification, "polyvinyl alcohol or a derivative thereof" may be referred to as "polyvinyl alcohol (derivative)".

(Primary particles that are at least partially water-insoluble)
The primary particles used in the present invention, which are at least partially water-insoluble, include water-insoluble primary particles and combinations of water-insoluble primary particles and water-soluble primary particles. Here, "water-insoluble" means that when 1 part by mass of the target particle is dissolved in 99 parts by mass of water at 25 ° C., less than 50% by mass thereof is dissolved, and "water-soluble" means that 50 under the same conditions. It means that% by mass or more is dissolved, and the aqueous solution is filtered through a filter paper (No. 2) and determined from the amount of solid content in the filtrate. The water-soluble primary particles preferably have a solubility of 90% by mass or more.
The water-insoluble primary particles and the water-soluble primary particles may be one type each or two or more types.
The primary particles that are at least partially water-insoluble are preferably at least two types of water-insoluble primary particles, or at least two types of water-insoluble primary particles and water-soluble primary particles, from the viewpoint of disintegration due to a decrease in the concentration of water-soluble salts. It is a combination with, more preferably, at least three kinds of water-insoluble primary particles, or a combination of at least three kinds of water-insoluble primary particles and water-soluble primary particles.

The primary particles may be organic particles or inorganic particles.
Examples of the water-insoluble organic primary particles include polyethylene, polypropylene, polyamide, polyethylene terephthalate, polystyrene and polyurethane or crosslinked products thereof, sodium poly (meth) acrylate, poly (meth) acrylic acid ester or crosslinked products thereof, and the like. Synthetic polymers such as polyethylene rubber, propylene rubber, styrene-butadiene rubber, butadiene rubber, silicone rubber and other rubbers or crosslinked products thereof; natural heights such as cellulose or its derivatives, chitosan or its derivatives, starch, fruit shells, etc. Examples thereof include molecules or derivatives thereof. Here, "poly (meth) acrylic acid" means both "polyacrylic acid" and "polymethacrylic acid". Among them, polyethylene, polyamide, polystyrene, sodium poly (meth) acrylate, poly (meth) acrylic acid ester, cellulose or a derivative thereof, and starch are preferable, and cellulose or a derivative thereof and starch are more preferable.

Examples of the water-insoluble inorganic primary particles include bentonite, talc, mica, kaolin, sepiolite, silica, calcium carbonate, titanium oxide, silicic acid anhydride, hydroxy calcium apatite, and pearls. Among them, bentonite, talc, mica, kaolin and silica are preferable, and mica is more preferable.
The water-insoluble primary particles are preferably a combination of water-insoluble organic primary particles and water-insoluble inorganic primary particles, and more preferably a combination of at least two types of water-insoluble organic primary particles and water-insoluble inorganic primary particles.
The mass ratio of the water-insoluble organic primary particles to the water-insoluble inorganic primary particles is determined from the viewpoint of long-term stability of the produced disintegrant particles in the cleaning agent product and disintegration due to a decrease in the concentration of water-soluble salts (water-insoluble organic primary particles). Particles) / (water-insoluble inorganic primary particles) = 50/50 to 100/0, more preferably 70/30 to 99/1, further 80/20 to 95/5, and further 85/15 to 92/8. preferable.

Examples of the water-soluble organic primary particles include polyvinyl alcohol or a derivative thereof, poly (meth) acrylic acid alkali salt, (meth) acrylic acid / (meth) acrylic acid ester copolymer alkali salt, and acrylic acid / maleic acid copolymer. Alkaline salts, synthetic polymers such as polyvinylpyrrolidone; methylcellulose, ethylcellulose, sodium carboxymethylcellulose, hydroxyalkylcellulose, modified starch (hydroxyalkyl-modified starch, phosphate ester-modified starch, etc.), sucrose, saccharides such as lactose; seaweeds , Natural polymers such as protein.

Examples of the water-soluble inorganic primary particles include chlorides such as sodium chloride, potassium chloride and magnesium chloride; sulfates such as sodium sulfate, potassium sulfate, magnesium sulfate and aluminum sulfate; and carbonates such as sodium carbonate and sodium hydrogencarbonate. .. In the case of sodium chloride, commercially available salt, high-purity purified salt, natural salt and the like are used.
The water-soluble primary particles are preferably water-soluble inorganic primary particles, and more preferably sodium chloride, potassium chloride, magnesium chloride, and sodium carbonate.

The shape of the primary particles may be a true sphere, a substantially sphere, or a deformed shape due to pulverization or the like. Further, hollow and porous particles can also be used. When two or more types of primary particles are used, the shapes may be the same or different.

The average particle size of the primary particles is preferably 100 μm or less, more preferably 70 μm or less, and preferably 0.1 μm or more, more preferably 1 μm or more.
In the present specification, the average particle size of the primary particles was measured using a laser diffraction / scattering type particle size distribution measuring device LA-920 (manufactured by HORIBA, Ltd.), and the median diameter was taken as the average particle size.

The mass ratio of the water-insoluble primary particles to the water-soluble primary particles is preferably in the range of (water-insoluble primary particles) / (water-soluble primary particles) = 1/99 to 100/0, and is in the range of 50/50 to 100/0. Is more preferable.

The disintegrating particles can further contain dyes, dyes, pigments, moisturizers, astringents, bactericides, ultraviolet absorbers, whitening agents, anti-inflammatory agents and the like, if necessary. These agents are contained in water-insoluble primary particles and water-soluble primary particles.

(Polyvinyl alcohol (derivative) aqueous solution)
The polyvinyl alcohol used in the present invention is a polymer obtained by saponifying polyvinyl acetate.
Derivatives of polyvinyl alcohol are chemically modified polyvinyl alcohols, and examples thereof include modified polyvinyl alcohols having functional groups other than hydroxyl groups and acetic acid groups such as anion-modified polyvinyl alcohol and cationic-modified polyvinyl alcohol.
Among them, an anions into which an anion group such as a sulfonic acid group or a carboxyl group has been introduced is preferable from the viewpoint of storage (granule) stability of disintegrating particles in a cleaning agent product and disintegration due to a decrease in the concentration of water-soluble salts. It is a modified polyvinyl alcohol, more preferably a carboxylic acid-modified polyvinyl alcohol having a carboxyl group introduced therein.

The carboxylic acid-modified polyvinyl alcohol is obtained by graft polymerization or block polymerization of polyvinyl alcohol and a vinyl carboxylic acid compound, or obtained by copolymerizing a vinyl ester compound and a vinyl carboxylic acid compound and then saponifying the compound. , And those obtained by reacting polyvinyl alcohol with a carboxylating agent and the like.
Examples of the vinylcarboxylic acid compound include carboxyl groups such as acrylic acid, methacrylic acid, (maleic anhydride) maleic acid, (anhydrous) phthalic acid, (anhydrous) itaconic acid, and (anhydrous) trimellitic acid, or an anhydride-containing compound thereof. ..
Examples of the vinyl ester compound include vinyl acetate, vinyl formate, vinyl propionate, vinyl versaticate, vinyl vivalate and the like.
Examples of the carboxylating agent include succinic anhydride, maleic anhydride, acetic anhydride, trimellitic anhydride, phthalic anhydride, pyromellitic anhydride, glutaric anhydride, hydrogenated phthalic anhydride, naphthalindicarboxylic acid anhydride and the like. Acid anhydrides can be mentioned.
These can be used individually by 1 type or in combination of 2 or more types.
The modification rate of the carboxylic acid-modified polyvinyl alcohol is not particularly limited, but is preferably 0.1 to 8 mol%, more preferably 1 to 5 mol%, still more preferably 1.5 to 3 mol%, still more preferably 1.7 to 2. It is 5.5 mol%.

The degree of salinity of polyvinyl alcohol (derivative) is 85 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, from the viewpoint of storage (granule) stability of disintegrating particles in the cleaning agent product. From the viewpoint of improving disintegration due to a decrease in the concentration of water-soluble salts, it is preferably 99.5 mol% or less, more preferably 99 mol% or less.
The degree of saponification of polyvinyl alcohol (derivative) is preferably 85 to 99.5 mol%, more preferably 90 to 99 mol%, and further preferably 95 to 99 mol%.
The molecular weight of polyvinyl alcohol (derivative) is preferably 5,000 or more, more preferably 30,000 or more, still more preferably 50,000 or more, from the viewpoint of storage (granule) stability of disintegrating particles in the cleaning agent product. From the viewpoint of ease of handling, it is preferably 200,000 or less, more preferably 150,000 or less, and further preferably 100,000 or less.
The molecular weight of polyvinyl alcohol (derivative) is preferably 5,000 to 200,000, more preferably 30,000 to 150,000, and even more preferably 50,000 to 100,000.
The molecular weight of polyvinyl alcohol can be calculated from the degree of polymerization.
The degree of polymerization can be calculated from the relative viscosity of a completely saponified polyvinyl alcohol aqueous solution and water (see JIS K6726: 1994).
Here, the degree of saponification can be measured according to JIS K 6726.

The viscosity of the aqueous polyvinyl alcohol (derivative) solution at the addition temperature is preferably 0.1 Pa · s or more, more preferably 0.5 Pa · s or more, and is not easy to handle, from the viewpoint of granulation control and uniform dispersion. From the viewpoint of ease, it is preferably 10 Pa · s or less, more preferably 8 Pa · s or less, still more preferably 6 Pa · s, still more preferably 5 Pa · s.
The viscosity of the aqueous polyvinyl alcohol (derivative) solution at the addition temperature is preferably 0.1 to 10 Pa · s, more preferably 0.5 to 8 Pa · s, still more preferably 0.5 to 6 Pa · s, still more preferably 0. .5 to 5 Pa · s.
The viscosity of the polyvinyl alcohol (derivative) aqueous solution is adjusted by the concentration and / or temperature of the existing aqueous solution.

The amount of the polyvinyl alcohol (derivative) aqueous solution added is at least partially water-insoluble from the viewpoint of achieving both long-term stability of the produced disintegrant particles in the cleaning agent product and disintegration due to a decrease in the concentration of water-soluble salts. It is preferable to select so as to be preferably 40 to 80 parts by mass, more preferably 45 to 70 parts by mass, and more preferably 50 to 60 parts by mass with respect to 100 parts by mass of the primary particles.
The amount of polyvinyl alcohol (derivative) added is preferably 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, and more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the primary particles in which at least a part is water-insoluble. It is preferably selected to be 3 to 15 parts by mass, more preferably 7 to 10 parts by mass.

(Stirring rolling granulation)
The stirring rolling granulator has a main stirring shaft equipped with a stirring blade in the center of the inside, and an auxiliary stirring shaft for assisting mixing and suppressing the generation of coarse particles is generally used as the main stirring shaft. It is a granulator having a structure in which it protrudes from the wall surface in a right-angled direction. Examples of the stirring and rolling granulator include a Henschel mixer, a super mixer, a high speed mixer, a vertical granulator, a ladyge mixer, a Spartan luzer, and a granule.

In the agitated rolling granulation, appropriate voids are generated in the disintegrating particles, consolidation is reduced, and at the same time, sufficient agglutination and sizing of the particles are possible to obtain disintegrating particles having initial performance. The peripheral speed at the tip of the stirring blade of the stirring rolling granulator is preferably adjusted to 5 to 40 m / s, more preferably 10 to 30 m / s.

Stirring rolling granulation is not particularly limited, but disintegrating particles are efficiently produced by adding and mixing an aqueous solution of polyvinyl alcohol (derivative) to primary particles that are at least partially water-insoluble. It is preferable because it can be done.
From the viewpoint of the composition of the primary particles, the uniformity of temperature, the granulation property, and the productivity, only the primary particles, which are at least partially water-insoluble, are charged into the stirring rolling granulator prior to the stirring rolling granulation. , Preliminary stirring may be mixed. The mixing time is preferably 3 to 30 minutes, more preferably 5 to 20 minutes. The jacket temperature in the stirring and rolling granulator equipped with a jacket is preferably 5 to 50 ° C, more preferably 8 to 35 ° C, and even more preferably 10 to 25 ° C.

The temperature at the time of stirring, rolling and granulating is preferably 5 to 80 ° C, more preferably 10 to 60 ° C, and even more preferably 15 to 50 ° C.
A water-soluble binder other than polyvinyl alcohol (derivative) may be used for stirring rolling granulation.

[Step (B)]
This step is a step of drying the fluidized bed at a wind speed of 0.4 to 1.2 m / s for the granulated product obtained by stirring, rolling and granulating in the step (A).

(Drying fluidized bed)
Fluidized bed drying is a direct heating method in which raw materials are fluidized and dried by hot air.
The wind speed of hot air is 0.4 to 1.2 m / s. By drying the fluidized bed at a wind speed of 0.4 to 1.2 m / s, it is possible to suppress the reduction in particle size of the granulated product, and it is possible to efficiently obtain disintegrating particles having a desired particle size distribution.
The wind speed of the hot air is preferably 1.0 m / s or less, more preferably 0.8 m / s or less from the viewpoint of suppressing the particle size of the granulated product, and is preferable from the viewpoint of improving productivity. Is 0.5 m / s or more, more preferably 0.6 m / s or more.
The wind speed of the hot air is preferably 0.5 to 1.0 m / s, more preferably 0.6 to 0.8 m / s.
Further, the inlet temperature of the hot air is preferably 200 ° C. or lower, more preferably 150 ° C. or lower, still more preferably 130 ° C. or lower, from the viewpoint of the quality of the granulated product, particularly the prevention of deterioration of solubility due to the crystallization of the binder. From the viewpoint of improving productivity, the temperature is preferably 90 ° C. or higher, more preferably 100 ° C. or higher, and even more preferably 110 ° C. or higher.

The drying end temperature by fluidized bed drying is preferably set to 50 ° C. or higher, further 60 ° C. or higher, and further 70 ° C. or higher from the viewpoint of reducing the water content after completion as the temperature of the disintegrating particles. From the viewpoint of the quality of the granulated product, particularly from the viewpoint of preventing deterioration of solubility due to crystallization of the binder, it is preferable to set the temperature to 100 ° C. or lower, more preferably 90 ° C. or lower, and further 85 ° C. or lower.
The drying temperature due to the drying of the fluidized bed can be measured with a thermometer installed in the fluidized section where the disintegrating particles flow.
The water content of the disintegrating particles after drying the fluidized bed is preferably 10% by mass or less, more preferably 8% by mass or less, still more preferably 6% by mass or less, still more preferably 4% by mass, from the viewpoint of improving the handling of the particles. Hereinafter, it is even more preferably 3% by mass or less.

The average particle size of the disintegrating particles after drying the fluidized bed is preferably 190 μm or more, more preferably 200 μm or more, still more preferably 250 μm or more, and preferably 250 μm or more, from the viewpoint of excellent physical detergency and massage feeling. It is 800 μm or less, more preferably 600 μm or less, still more preferably 500 μm or less.
The average particle size of the disintegrating particles after drying the fluidized bed is preferably 190 to 800 μm, more preferably 200 to 600 μm, and even more preferably 250 to 500 μm.
In the present specification, the average particle size of the disintegrating particles can be measured according to the method described in Examples below.

From the viewpoint of quality, the proportion of particles having a size of 125 μm or less contained in the disintegrating particles after drying the fluidized bed is preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 15% by mass or less, still more preferably. Is 10% by mass or less.

(Classification)
After drying the fluidized bed, a step of classifying the disintegrating particles may be performed. For classification, the vibrating sieve type is preferable because the sieving efficiency is good and the number of auxiliary equipment is small, so that capital investment can be suppressed. Further, the one that moves horizontally (vibrates) is suitable because the sieve is less likely to be clogged even if it is operated for a long time.
As the vibrating sieve type classifier, a continuous type is preferable, and examples thereof include a gyro type, a rotary type, a gravity type, a centrifugal force type, and a circular vibrating sieve.

In the classification, the temperature of the disintegrating particles is preferably 30 ° C. or higher. The classification is usually carried out by cooling in consideration of suppressing fusion and aggregation due to heat, but by classifying at a temperature of 30 ° C. or higher for the disintegrating particles, fine particles having a small particle size are desired. It is possible to suppress mixing with disintegrating particles having a particle size distribution of.
The temperature of the disintegrating particles at the time of classification is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, still more preferably 50 ° C. or higher, still more preferably 60 ° C. or higher, from the viewpoint of suppressing the mixing of particles having a small particle size. Also, from the viewpoint of quality, it is preferably 100 ° C. or lower, more preferably 95 ° C. or lower, still more preferably 90 ° C. or lower, still more preferably 85 ° C. or lower.
The temperature of the disintegrating particles at the time of classification is preferably 30 to 100 ° C, more preferably 40 to 95 ° C, still more preferably 50 to 90 ° C, still more preferably 60 to 85 ° C.
From the viewpoint of sieving efficiency, the amount of disintegrating particles supplied during classification is preferably 10 to 1000 kg / hr, more preferably 50 to 800 kg / hr, still more preferably 100 to 600 kg / hr, still more preferably 150 to 500 kg / hr. hr.

From the viewpoint of quality, the proportion of granules of 125 μm or less contained in the disintegrating particles having a desired particle size distribution after classification is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass. Hereinafter, it is more preferably 20% by mass or less, and even more preferably 15% by mass or less. Further, the proportion of particles of 125 μm or less contained in the disintegrating particles having a desired particle size distribution after classification is preferably 0% by mass, but from the viewpoint of productivity, 1% by mass or more, further 3% by mass or more, and further. 5% by mass or more is preferable.

The bulk density of the disintegrating particles after classification is excellent in storage (granule) stability of the disintegrating particles in the cleaning agent product, physical detergency and massage feeling, and disintegration due to a decrease in the concentration of water-soluble salts. From this point of view, it is preferably 0.3 to 1.0 g / mL, more preferably 0.4 to 0.9 g / mL, and even more preferably 0.5 to 0.8 g / mL.

(Crushing)
After the classification, a step of crushing the coarse granules may be performed. The crushing method is not particularly limited, but can be carried out by, for example, a method using a crusher of a roller mill, a high-speed rotary crusher (pin mill, hammer mill, etc.), or a container-driven mill (rotary mill, vibration mill, etc.). Among them, it is preferable to use a pin mill from the viewpoint that disintegrating particles having a desired particle size distribution can be produced in good yield. The crushing conditions such as the crushing time, the temperature at the time of crushing, and the rotation speed of the crusher may be appropriately set in order to form desired particles.
The temperature at the time of pulverization is preferably less than the melting point or softening point of the polyvinyl alcohol (derivative) aqueous solution.
The step of classifying and the step of pulverizing may be repeated a plurality of times until the desired particle size range is reached.

Disintegrating particles with the desired particle size distribution from the disintegrating particles after drying the fluidized layer (disintegrating particles that pass through a 311 μm wire mesh and do not pass through a 132 μm wire mesh; From the viewpoint of production efficiency, the yield (recovered from) is preferably 20% by mass or more, more preferably 40% by mass or more, and further preferably 60% by mass or more.

When the disintegrating particles thus produced are blended with a cleaning agent or the like, the disintegrating particles are stably dispersed without disintegrating because the concentration of water-soluble salts is high in the cleaning agent product. On the other hand, in the cleaning process and the rinsing process, the particles disintegrate when the concentration of water-soluble salts in the cleaning agent product decreases. Considering the formulation in such a cleaning agent, the disintegration property of the disintegrating particles of the present invention is at least partially in an aqueous solution having a water-soluble salt concentration of less than 1% by mass, more preferably less than 1.5% by mass. It is preferable to selectively design the binder so that the particles disintegrate, and from the viewpoint of washability with rinsing water, in an aqueous solution having a water-soluble salt concentration of less than 1% by mass, more preferably less than 1.5% by mass, before washing. It is more preferable that it is designed so that 70% by mass or more of the disintegrating particles (that is, before disintegration) disintegrate.

The disintegrating particles produced by the method of the present invention include water-soluble salts, surfactants, oils, thickeners, solvents, moisturizers, colorants, preservatives, feel improvers, fragrances, anti-inflammatory agents, disinfectants, and ultraviolet rays. In combination with absorbents, moisturizers, etc., for example, washing pigments, whole body cleaning agents, skin cleaning agents such as bar soap, hair cleaning agents such as shampoo, dish cleaning agents, contact lens cleaning agents, toothpastes, massage creams. It can be widely used as a massage agent and the like. Above all, it is useful as a raw material for skin cleansers.

Aspects and preferred embodiments of the present invention are shown below.

<1> (A) A step of stirring, rolling and granulating primary particles, which are at least partially insoluble in water, using an aqueous solution of polyvinyl alcohol or a derivative thereof, and (B) a granulated product obtained in step (A). A method for producing disintegrating particles, which comprises a step of drying the fluidized bed at a wind speed of 0.4 to 1.2 m / s.

<2> The primary particles that are at least partially water-insoluble are preferably water-insoluble primary particles, or a combination of water-insoluble primary particles and water-soluble primary particles, and more preferably at least two types of water-insoluble primary particles. Alternatively, a combination of at least two types of water-insoluble primary particles and water-soluble primary particles, more preferably at least three types of water-insoluble primary particles, or a combination of at least three types of water-insoluble primary particles and water-soluble primary particles. Yes, more preferably a combination of water-insoluble organic primary particles and water-insoluble inorganic primary particles, and even more preferably a combination of at least two types of water-insoluble organic primary particles and water-insoluble inorganic primary particles, <1>. The method for producing disintegrating particles according to the above.
<3> The mass ratio of the water-insoluble primary particles to the water-soluble primary particles is preferably in the range of (water-insoluble primary particles) / (water-soluble primary particles) = 1/99 to 100/0, and more preferably 50. The method for producing disintegrating particles according to <2>, which is in the range of / 50 to 100/0.
<4> The mass ratio of the water-insoluble organic primary particles to the water-insoluble inorganic primary particles is preferably in the range of (water-insoluble organic primary particles) / (water-insoluble inorganic primary particles) = 50/50 to 100/0. The disintegration according to <2>, preferably in the range of 70/30 to 99/1, more preferably in the range of 80/20 to 95/5, and even more preferably in the range of 85/15 to 92/8. Method for producing sex particles.
<5> The water-insoluble organic primary particles are preferably polyethylene, polypropylene, polyamide, polyethylene terephthalate, polystyrene, polyurethane or crosslinked products thereof, sodium poly (meth) acrylate, poly (meth) acrylic acid ester or crosslinked products thereof. , Polyethylene rubber, propylene rubber, styrene-butadiene rubber, butadiene rubber, silicone rubber or crosslinked products thereof, cellulose or derivatives thereof, chitosan or derivatives thereof, starch, natural polymers of fruit shells or derivatives thereof, more preferably Is polyethylene, polyamide, polystyrene, sodium poly (meth) acrylate, poly (meth) acrylic acid ester, cellulose or a derivative thereof, or a starch, and more preferably cellulose or a derivative thereof or a starch <2> to <4>. The method for producing disintegrating particles according to any one of.
<6> The water-insoluble inorganic primary particles are preferably bentonite, talc, mica, kaolin, sepiolite, silica, calcium carbonate, titanium oxide, silicic anhydride, hydroxy calcium apatite, and pearl, and more preferably bentonite and talc. , Mica, kaolin, silica, and more preferably mica. The method for producing disintegrating particles according to any one of <2> to <5>.
<7> The water-soluble organic primary particles are preferably polyvinyl alcohol or a derivative thereof, poly (meth) acrylic acid alkali salt, (meth) acrylic acid / (meth) acrylic acid ester copolymer alkali salt, acrylic acid / maleine. Alkaline salts of acid copolymers, polyvinylpyrrolidone, methylcellulose, ethylcellulose, sodium carboxymethylcellulose, hydroxyalkylcellulose, modified starch (hydroxyalkyl-modified starch, phosphate ester-modified starch, etc.), sucrose, lactose, seaweed or protein natural The method for producing disintegrant particles according to any one of <2> to <6>, which is a polymer.
<8> The water-soluble inorganic primary particles are preferably sodium chloride, potassium chloride, magnesium chloride, sodium sulfate, potassium sulfate, magnesium sulfate, aluminum sulfate, sodium carbonate, sodium hydrogen carbonate, and more preferably sodium chloride and potassium chloride. The method for producing disintegrating particles according to any one of <2> to <7>, which is magnesium chloride or sodium carbonate.
<9> The average particle size of the primary particles, which are at least partially water-insoluble, is preferably 100 μm or less, more preferably 70 μm or less, and preferably 0.1 μm or more, more preferably 1 μm or more <1. > To the method for producing disintegrating particles according to any one of <8>.
<10> The derivative of polyvinyl alcohol is preferably a modified polyvinyl alcohol having a functional group other than a hydroxyl group and an acetic acid group, more preferably an anion-modified polyvinyl alcohol, and further preferably a carboxylic acid-modified polyvinyl having a carboxyl group introduced therein. The method for producing disintegrating particles according to any one of <1> to <9>, which is an alcohol.
<11> The modification rate of the carboxylic acid-modified polyvinyl alcohol is preferably 0.1 to 8 mol%, more preferably 1 to 5 mol%, still more preferably 1.5 to 3 mol%, still more preferably 1.7 to 2.5 mol. The method for producing disintegrating particles according to <10>, which is%.
<12> The degree of saponification of polyvinyl alcohol or a derivative thereof is preferably 85 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more, and preferably 99.5 mol% or less, more preferably 99 mol. % Or less, preferably 85 to 99.5 mol%, more preferably 90 to 99 mol%, still more preferably 95 to 99 mol%, according to any one of <1> to <11>. Manufacturing method.
<13> The molecular weight of polyvinyl alcohol or a derivative thereof is preferably 5,000 or more, more preferably 30,000 or more, still more preferably 50,000 or more, and preferably 200,000 or less, more preferably 150,000 or less, still more preferably. The collapse according to any one of <1> to <12>, which is 100,000 or less, preferably 5,000 to 200,000, more preferably 30,000 to 150,000, and further preferably 50,000 to 100,000. Method for producing sex particles.
<14> The viscosity of polyvinyl alcohol or an aqueous solution thereof at the addition temperature is preferably 0.1 Pa · s or more, more preferably 0.5 Pa · s or more, and preferably 10 Pa · s or less, more preferably. It is 8 Pa · s or less, more preferably 6 Pa · s, further preferably 5 Pa · s, and preferably 0.1 to 10 Pa · s, more preferably 0.5 to 8 Pa · s, still more preferably 0.5. The method for producing disintegrating particles according to any one of <1> to <13>, which is ~ 6 Pa · s, more preferably 0.5 to 5 Pa · s.
<15> The amount of polyvinyl alcohol or an aqueous solution thereof added is preferably 40 to 80 parts by mass, more preferably 45 to 70 parts by mass, more preferably with respect to 100 parts by mass of the primary particles in which at least a part is water-insoluble. The method for producing disintegrating particles according to any one of <1> to <14>, wherein is 50 to 60 parts by mass.
<16> The amount of polyvinyl alcohol or a derivative thereof added is preferably 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, and further, with respect to 100 parts by mass of the primary particles in which at least a part is water-insoluble. The method for producing disintegrating particles according to any one of <1> to <15>, which is preferably 3 to 15 parts by mass, more preferably 7 to 10 parts by mass.
<17> Any of <1> to <16> in which the peripheral speed at the tip of the stirring blade of the stirring rolling granulator is adjusted to preferably 5 to 40 m / s, more preferably 10 to 30 m / s. The method for producing disintegrating particles according to 1.
<18> Prior to the stirring rolling granulation, a step of charging only the primary particles, which are at least partially water-insoluble, into the stirring rolling granulator and pre-stirring and mixing is included, and the mixing time is preferably 3 to 30. Minutes, more preferably 5 to 20 minutes, and the jacket temperature in a stirring rolling granulator equipped with a jacket is preferably 5 to 50 ° C, more preferably 8 to 35 ° C, still more preferably 10 to 10. The method for producing disintegrating particles according to any one of <1> to <17> at 25 ° C.
<19> The temperature at the time of stirring, rolling and granulating is preferably 5 to 80 ° C., more preferably 10 to 60 ° C., still more preferably 15 to 50 ° C., according to any one of <1> to <18>. Method for producing disintegrating particles.
<20> The wind speed of hot air in fluidized bed drying is preferably 1.0 m / s or less, more preferably 0.8 m / s or less, and preferably 0.5 m / s or more, more preferably 0.6 m. The disintegration property according to any one of <1> to <19>, which is more than / s, preferably 0.5 to 1.0 m / s, and more preferably 0.6 to 0.8 m / s. How to make particles.
<21> The inlet temperature of hot air in fluidized bed drying is preferably 200 ° C. or lower, more preferably 150 ° C. or lower, still more preferably 130 ° C. or lower, and preferably 90 ° C. or higher, more preferably 100 ° C. or higher. The method for producing disintegrating particles according to any one of <1> to <20>, which is more preferably 110 ° C. or higher.
<22> The drying end temperature in the fluidized bed drying is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, further preferably 70 ° C. or higher, and preferably 100 ° C. or lower, more preferably 90 ° C. or lower, still more preferably. The method for producing disintegrating particles according to any one of <1> to <21>, which is set to be 85 ° C. or lower.
<23> The water content of the disintegrating particles after drying the fluidized bed is preferably 10% by mass or less, more preferably 8% by mass or less, still more preferably 6% by mass or less, still more preferably 4% by mass or less, still more preferably. The method for producing disintegrating particles according to any one of <1> to <22>, wherein is 3% by mass or less.
<24> The average particle size of the disintegrating particles after drying the fluidized bed is preferably 190 μm or more, more preferably 200 μm or more, still more preferably 250 μm or more, and preferably 800 μm or less, more preferably 600 μm or less, and further. The method for producing disintegrating particles according to any one of <1> to <23>, which is preferably 500 μm or less, preferably 190 to 800 μm, more preferably 200 to 600 μm, and even more preferably 250 to 500 μm. ..
<25> The proportion of particles of 125 μm or less contained in the disintegrating particles after drying the fluidized bed is preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 15% by mass or less, still more preferably 10. The method for producing disintegrating particles according to any one of <1> to <24>, which has a mass% or less.
<26> The method for producing disintegrating particles according to any one of <1> to <25>, further comprising a step of classifying the disintegrating particles at a temperature of 30 ° C. or higher after drying the fluidized bed.
<27> The method for producing disintegrating particles according to <26>, preferably using a vibrating sieve type classifier.
<28> The temperature of the disintegrating particles at the time of classification is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, further preferably 50 ° C. or higher, further preferably 60 ° C. or higher, and preferably 120 ° C. or lower. It is more preferably 110 ° C. or lower, still more preferably 100 ° C. or lower, still more preferably 90 ° C. or lower, still preferably 30 to 120 ° C., more preferably 40 to 110 ° C., still more preferably 50 to 100 ° C., still more preferably. The method for producing disintegrating particles according to <26> or <27>, wherein is 60 to 90 ° C.
<29> The supply amount of disintegrating particles at the time of classification is preferably 10 to 1000 kg / hr, more preferably 50 to 800 kg / hr, still more preferably 100 to 600 kg / hr, still more preferably 150 to 500 kg / hr. The method for producing disintegrating particles according to any one of <26> to <28>.
<30> The proportion of particles of 125 μm or less contained in the disintegrating particles having a desired particle size distribution after classification is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less. It is more preferably 20% by mass or less, still more preferably 15% by mass or less, preferably 0% by mass or more, preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass. The method for producing disintegrating particles according to any one of <26> to <29>, which has a mass% or more.
<31> The bulk density of the disintegrating particles after classification is preferably 0.3 to 1.0 g / mL, more preferably 0.4 to 0.9 g / mL, and even more preferably 0.5 to 0.8 g. The method for producing disintegrating particles according to any one of <26> to <30>, which is / mL.
<32> The method for producing disintegrating particles according to any one of <26> to <31>, further comprising a step of pulverizing the coarse particles obtained after classification.
<33> The method for producing disintegrating particles according to <32>, wherein a roller mill, a high-speed rotary crusher, or a container-driven mill is preferably used, and a pin mill is more preferably used.
<34> The method for producing disintegrating particles according to <32> or <33>, wherein the temperature at the time of pulverization is less than the melting point or softening point of the aqueous solution of polyvinyl alcohol or a derivative thereof.
<35> The method for producing disintegrating particles according to any one of <26> to <34>, wherein the step of classifying and the step of pulverizing are repeated a plurality of times.
<36> The yield of disintegrating particles from the disintegrating particles after drying the fluidized bed, which passes through the 311 μm wire mesh and does not pass through the 132 μm wire mesh, is preferably 20% by mass or more, more preferably 40% by mass or more, and further. The method for producing disintegrating particles according to any one of <26> to <35>, which is preferably 60% by mass or more.
<37> 70% by mass or more of the disintegrating particles are disintegrated with respect to the disintegrating particles before disintegration in an aqueous solution having a water-soluble salt concentration of preferably less than 1% by mass, more preferably less than 1.5% by mass. 1> The method for producing disintegrating particles according to any one of <36>.

In the following examples, "%" means "mass%".

[Analysis method]
(I) Measurement of average particle size JIS Z 8801-1 (established on May 20, 2000, final revision on November 20, 2006) stipulated in 2000, 1400, 1000, 710, 500, 355, 250, 180, 125 , 90, 63, 45 μm 12-stage sieve and saucer, stack in order from the sieve with the smallest opening on the saucer, add 100 g of particles from the top 2000 μm sieve, cover and low tap Attached to a mold sieve (manufactured by HEIKO Seisakusho, tapping 156 times / minute, rolling: 290 times / minute), and vibrated for 5 minutes, the mass of the particles remaining on each sieve and saucer was measured. The mass ratio (%) of the particles on each sieve was calculated. The mass ratios of the particles on a sieve having a small opening were integrated in order from the saucer, and the particle size having a total of 50% was defined as the average particle size.

(Ii) Measurement of Viscosity of Polyvinyl Alcohol (Derivative) Aqueous Solution The viscosity at the aqueous solution addition temperature was measured with a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) according to JIS Z 8803.

(Iii) Measurement of Moisture Content Disintegrating particles having a desired particle size distribution (disintegrating particles classified by a sieve of 132 to 311 μm and recovered from a 132 μm net) are placed in a flat-bottomed dish and weighed at 105 ° C./. Dry for 2 hours. After drying, allow to cool to room temperature for about 30 minutes in a desiccator and weigh. [Moisture content [%]] = [Weight of sample before drying (g) -Weight of sample after drying (g)] / [Sampling amount (g)] × 100.

(Iv) Method for measuring bulk density Place the "apparent density measuring device" described in JIS K3362 horizontally, and classify the disintegrating particles (132 to 311 μm sieve) having the desired particle size distribution from the funnel into the weighed cylindrical container. (Collapsed particles recovered from a 132 μm net) are naturally dropped. Scrape the raised sample from the container and weigh the container. [Bulk density (g / mL)] = [Weight of sample in container (g)] / [Volume of container (mL)].

(V) Temperature measuring method of disintegrating particles (classification step)
The temperature of the sample of disintegrating particles before classification was measured using a general digital thermometer.

Example 1
Cellulose (trade name: KC Flock W-400G, manufactured by Nippon Paper Co., Ltd.) 10.0 kg, corn starch (trade name: Nippon Pharmaceutical Co., Ltd. corn starch, Matsutani Chemical Industry Co., Ltd.) so as to have the blending ratio shown in Table 1. 10.0 kg, mica (trade name: Micromica MK-100, manufactured by Katakura Corp Agri Co., Ltd.) 2.22 kg, black iron oxide (trade name: TAROX BL-100, manufactured by Miyoshi Kasei Co., Ltd.) 0. 45 kg of powder was charged into a stirring and rolling granulator (super mixer, capacity 200 L), and the stirring blades (upper blade: S type, lower blade: D type) were rotated at 550 r / min (tip peripheral speed of the stirring blade: 18). It was mixed for 20 minutes under the condition of .6 m / s). Here, 15 parts by mass of carboxylic acid-modified polyvinyl alcohol (PVA, trade name: KM-118, manufactured by Kuraray Co., Ltd., molecular weight 80,000, degree of polymerization 1800, degree of saponification 95.5-98.5%) is purified water. 12.47 kg of an aqueous solution (viscosity: 4 Pa · s) at a temperature of 40 ° C. dissolved in 85 parts by mass was added in 10 minutes and stirred for 3.5 minutes to obtain a granulated product.
The obtained granules were charged in a fluidized bed dryer (manufactured by Glatt, WSG-60 type), and hot air at 120 ° C. was dried at a wind speed of 0.5 m / s in the fluidized bed dryer for 50 minutes, and the disintegration property was 80 ° C. Particles (moisture content 2%) were obtained.
As a result of measuring the average particle size of the disintegrating particles, it was 300 μm.
Further, the ratio of particles having a size of 125 μm or less (125 μm ratio) contained in the dried product was determined by the particle size distribution and found to be 6%.

Example 2
Disintegrant particles were obtained in the same manner as in Example 1 except that the hot air in the fluidized bed dryer was set to a wind speed of 0.7 m / s and dried for 35 minutes.
The average particle size of the disintegrating particles was 290 μm. In addition, the proportion of granules of 125 μm or less contained in the dried product was 8%.

Example 3
Cellulose (trade name: KC Flock W-400G, manufactured by Nippon Paper Co., Ltd.) 60.0 kg, cornstarch (trade name: Nippon Pharmacy Ho, Corn Starch, Matsutani Chemical Industry Co., Ltd.) so as to have the blending ratio shown in Table 1. 60.0 kg of powder and 13.3 kg of mica (trade name: Micromica MK-100, manufactured by Katakura Corp. Agri Co., Ltd.) were charged into a stirring and rolling granulator (Henshell mixer, capacity 1000L), and the stirring blades were used. (Upper blade: Y1 type, lower blade: B0 type) were mixed for 20 minutes under the condition of a rotation speed of 320 r / min (agitating blade tip peripheral speed: 18 m / s). Here, 15 parts by mass of carboxylic acid-modified polyvinyl alcohol (PVA, trade name: KM-118, manufactured by Kuraray Co., Ltd., molecular weight 80,000, degree of polymerization 1800, degree of saponification 95.5-98.5%) is purified water. 74.5 kg of an aqueous solution (viscosity: 2 Pa · s) at a temperature of 65 ° C. dissolved in 85 parts by mass was added in 10 minutes and stirred for 16 minutes to obtain a granulated product.
Example 1 except that the obtained granules were charged in a fluidized bed dryer (manufactured by Okawara Seisakusho, FBSC-15 type), the wind speed of hot air in the fluidized bed dryer was 1.0 m / s, and the particles were dried for 40 minutes. The disintegrating particles were obtained in the same manner as in.
As a result of measuring the average particle size of the disintegrating particles, it was 400 μm. In addition, the proportion of granules of 125 μm or less contained in the dried product was 10%.

Comparative Example 1
Disintegrant particles were obtained in the same manner as in Example 1 except that the hot air in the fluidized bed dryer was set to a wind speed of 1.3 m / s and dried for 10 minutes.
The average particle size of the disintegrating particles was 180 μm. The proportion of granules of 125 μm or less contained in the dried product was 28%.

Comparative Example 2
When the wind speed of the hot air in the fluidized bed dryer was set to 0.3 m / s, the granulated product did not fluidize and no disintegrating particles were obtained.

Comparative Example 3
Cellulose (trade name: KC Flock W-400G, manufactured by Nippon Paper Co., Ltd.) 1.25 kg, cornstarch (trade name: Nippon Pharmacy Ho, Corn Starch, Matsutani Chemical Industry Co., Ltd.) 1.25 kg of powder (trade name: Micromica MK-100, manufactured by Katakura Corp. Agri Co., Ltd.) 0.30 kg of powder was charged into a stirring and rolling granulator (Henshell mixer, capacity 20L), and the stirring blades were used. (Upper blade: Y1 type, lower blade: B0 type) were mixed for 5 minutes under the condition of a rotation speed of 1260 r / min (agitating blade tip peripheral speed: 18 m / s). Here, 15 parts by mass of carboxymethyl cellulose-sodium salt (CMC-Na, trade name: Sunrose F01MC, manufactured by Nippon Paper Industries, Ltd., etherification degree 0.65 to 0.75) was dissolved in 85 parts by mass of purified water. 1.6 kg of an aqueous solution (viscosity: 5 Pa · s) at a temperature of 40 ° C. was added in 10 minutes, and the mixture was stirred for 6 minutes to obtain granulated products.
Next, the obtained granulated product was dried in a fluidized bed dryer in the same manner as in Example 3 to obtain disintegrating particles.
The average particle size of the disintegrating particles was 130 μm. The proportion of granules of 125 μm or less contained in the dried product was 49%.
Table 1 shows the results of Examples 1 to 3 and Comparative Examples 1 to 3.

As is clear from Table 1, the primary particles are stirred, rolled and granulated using an aqueous solution of polyvinyl alcohol (derivative), and then dried at a predetermined wind speed with a fluidized bed dryer to reduce the particle size of the granulated particles. It was possible to efficiently obtain disintegrating particles having a desired particle size.

Example 4
Cellulose (trade name: KC Flock W-400G, manufactured by Nippon Paper Co., Ltd.) 22.5 kg, cornstarch (trade name: Nippon Pharmacy Ho, Corn Starch, Matsutani Chemical Industry Co., Ltd.) so as to have the blending ratio shown in Table 2. 22.5 kg of powder (trade name: Micromica MK-100, manufactured by Katakura Corp. Agri Co., Ltd.) 5.0 kg of powder was charged into a stirring and rolling granulator (super mixer, capacity 500 L), and the stirring blades were used. (Upper blade: S type, lower blade: D type) were mixed for 20 minutes under the condition of a rotation speed of 370 r / min (agitating blade tip peripheral speed: 13 m / s). Here, 15 parts by mass of carboxylic acid-modified polyvinyl alcohol (trade name: KM-118, manufactured by Kuraray Co., Ltd., molecular weight 80,000, degree of polymerization 1800, degree of saponification 95.5-98.5%) was added to 85 parts by mass of purified water. 27.5 kg of an aqueous solution (viscosity: 1.5 Pa · s) dissolved in the portion at a temperature of 65 ° C. was added in 10 minutes, and the mixture was stirred for 6 minutes to obtain a granulated product.
The obtained granules were charged into a fluidized bed dryer (manufactured by Glatt, WSG-60 type), and hot air at 120 ° C. was dried at a wind speed of 0.7 m / s in the fluidized bed dryer for 35 minutes, and collapsed at 80 ° C. Sex particles (moisture content 2%) were obtained.
Next, the disintegrating particles at 60 ° C. after drying were classified by a gyro type classifier using a sieve having an opening diameter of 311 μm and 132 μm as a classifying wire mesh.
The proportion of particles of 125 μm or less (125 μm proportion) contained in the disintegrating particles that passed through the 311 μm wire mesh and did not pass through the 132 μm wire mesh was determined by the particle size distribution and found to be 11%. The bulk density of the disintegrating particles was 0.7 g / mL.

Example 5
Cellulose (trade name: KC Flock W-400G, manufactured by Nippon Paper Co., Ltd.) 60 kg, cornstarch (trade name: Nippon Pharmacy Ho, corn starch, manufactured by Matsutani Chemical Industry Co., Ltd.) so as to have the blending ratio shown in Table 2. 60 kg of mica (trade name: Micromica MK-100, manufactured by Katakura Corp. Agri Co., Ltd.) 13.3 kg of powder was charged into a stirring rolling granulator (Henshell mixer, capacity 1000L), and the stirring blades (upper blades: upper blades: Y1 type, lower blade: B0 type) was mixed for 20 minutes under the condition of a rotation speed of 320 r / min (agitating blade tip peripheral speed: 18 m / s). Here, 15 parts by mass of carboxylic acid-modified polyvinyl alcohol (trade name: KM-118, manufactured by Kuraray Co., Ltd., molecular weight 80,000, degree of polymerization 1800, degree of saponification 95.5-98.5%) was added to 85 parts by mass of purified water. 74.5 kg of an aqueous solution (viscosity: 1.5 Pa · s) at a temperature of 65 ° C. dissolved in the portion was added in 10 minutes and stirred for 16 minutes to obtain a granulated product.
Example 4 except that the obtained granules were charged in a fluidized bed dryer (manufactured by Okawara Seisakusho, FBSC-15 type), the wind speed of hot air in the fluidized bed dryer was 1.0 m / s, and the particles were dried for 40 minutes. The disintegrating particles were obtained in the same manner as in.
Then, the disintegrating particles at 80 ° C. after drying were classified by a gyro type classifier using a sieve having an opening diameter of 311 μm and 132 μm as a classifying wire mesh.
The proportion of particles of 125 μm or less contained in the disintegrating particles that passed through the 311 μm wire mesh and did not pass through the 132 μm wire mesh was 10%. The bulk density of the disintegrating particles was 0.7 g / mL.

Example 6
Disintegrating particles were obtained in the same manner as in Example 4 except that the disintegrating particles at 25 ° C. were classified by a gyro type classifier after drying.
The proportion of particles of 125 μm or less contained in the disintegrating particles that passed through the 311 μm wire mesh and did not pass through the 132 μm wire mesh was 42%.
Table 2 shows the results of Examples 4 to 6.

As is clear from Table 2, when the temperature of the disintegrating particles at the time of classification was high, it was advantageous to suppress the mixture of small particles in the disintegrating particles having a desired particle size.

Example 7
Cellulose (trade name: KC Flock W-400G, manufactured by Nippon Paper Co., Ltd.) 60 kg, cornstarch (trade name: Nippon Pharmacy Ho, corn starch, manufactured by Matsutani Chemical Industry Co., Ltd.) so as to have the blending ratio shown in Table 3. 60 kg of mica (trade name: Micromica MK-100, manufactured by Katakura Corp. Agri Co., Ltd.) 13.3 kg of powder was charged into a stirring rolling granulator (Henshell mixer, capacity 1000L), and the stirring blades (upper blades: upper blades: Y1 type, lower blade: B0 type) was mixed for 20 minutes under the condition of a rotation speed of 320 r / min (agitating blade tip peripheral speed: 18 m / s). Here, 15 parts by mass of carboxylic acid-modified polyvinyl alcohol (trade name: KM-118, manufactured by Kuraray Co., Ltd., molecular weight 80,000, degree of polymerization 1800, degree of saponification 95.5-98.5%) was added to 85 parts by mass of purified water. 74.5 kg of an aqueous solution (viscosity: 1.5 Pa · s) at a temperature of 65 ° C. dissolved in the portion was added in 10 minutes and stirred for 16 minutes to obtain a granulated product.
The obtained granules were charged in a fluidized bed dryer (FBSC-15 type manufactured by Okawara Seisakusho), and hot air at 120 ° C. was dried at a wind speed of 1 m / s in the fluidized bed dryer for 40 minutes, and the disintegration property was 80 ° C. Particles (moisture content 2%) were obtained.
Next, the disintegrating particles at 80 ° C. after drying were classified using a gyro type classifier and a sieve having an opening diameter of 311 μm and 132 μm as the classifying wire mesh.
With respect to the disintegrating particles after drying, 27% of the disintegrating particles (disintegrating particles that passed through the 311 μm wire mesh and did not pass through the 132 μm wire mesh) were recovered.

Example 8
The collapsing particles obtained in Example 7 having an opening diameter of 311 μm and not passing through the classified wire mesh were subjected to a rotation speed of 11300 r / min (blade tip peripheral speed: 80 m / s) using a pin type crusher (Coloplex 250Z). Grinded below. The crushed disintegrating particles were classified by a gyro type classifier, and crushed and classified repeatedly until they passed through a 311 μm wire mesh.
With respect to the disintegrating particles after drying, 64% of the disintegrating particles (disintegrating particles that passed through the 311 μm wire mesh and did not pass through the 132 μm wire mesh) were recovered.

Table 3 shows the results of Examples 7 and 8.

As shown in Table 3, after the fluidized bed was dried, further classification and pulverization were performed to obtain disintegrating particles in a desired particle size range in a high yield.

Claims (6)

(A) A step of stirring, rolling and granulating a water-insoluble primary particle or a combination of a water-insoluble primary particle and a water-soluble primary particle using an aqueous solution of polyvinyl alcohol or a derivative thereof, and a step (B). The step of drying the fluidized bed at a wind velocity of 0.4 to 1.2 m / s and (C) after drying the fluidized bed, the disintegrating particles obtained in step (B) are set as the temperature of the disintegrating particles by 50. A method for producing disintegrating particles, which comprises a step of classifying at ° C or higher. The method for producing disintegrating particles according to claim 1, wherein the aqueous solution of polyvinyl alcohol or a derivative thereof is a carboxylic acid-modified polyvinyl alcohol aqueous solution. The method for producing disintegrating particles according to claim 1 or 2 , further comprising a step of pulverizing the coarse particles obtained after classification. The method for producing disintegrating particles according to any one of claims 1 to 3 , wherein the average particle size of the disintegrating particles is 190 to 800 μm. The method for producing disintegrating particles according to any one of claims 1 to 4 , wherein the water-insoluble primary particles are a combination of water-insoluble organic primary particles and water-insoluble inorganic primary particles. The disintegration property according to any one of claims 1 to 5 , wherein the yield of the disintegrating particles from the disintegrating particles after drying the fluidized bed is 20% by mass or more of the disintegrating particles that pass through the 311 μm wire mesh and do not pass through the 132 μm wire mesh. How to make particles.