JP2001293354A - Method for manufacturing breakable particles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily manufacturing expected breakable particles, which have breaking properties good in scrub feeling when used in a skin detergent, in a good yield. SOLUTION: Breakable particles are manufactured by stirring and tumbling primary particles, which are insoluble in water at least partially, using a salt- sensitive binder solution with a viscosity of 0.1-10.0 Pa.s to granulate them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for efficiently producing disintegrating particles which are not damaged by skin or itch due to the disintegration of particles due to a decrease in the concentration of salts dissolved in water during washing and rinsing. .

[0002]

2. Description of the Related Art Washing-off type facial cleansers, body soaps, solid soaps and other skin cleansing agents, massage creams, etc., which contain particles, are difficult to remove with ordinary skin cleansing agents by physical cleaning. It has the characteristic that dirt and the like that have entered the pores can be washed away. In addition, since a moderate feeling of use (scrub feeling) of washing with particles can be obtained when washing the skin, there is a wide and persistent demand. Examples of conventionally used particles include particles obtained by pulverizing plant seeds and particles of about 50 to 1000 μm made of a hydrocarbon polymer such as polyethylene and polystyrene.

[0003]

However, these particles have high physical and cleaning effects and a high scrubbing feeling, but have a problem of irritation to the skin and rough skin, poor washing properties after use, and particles remaining. was there. In order to solve such a problem, a technique has been proposed in which fine water-insoluble polymer powder is granulated with alkylcellulose and hydroxyalkylcellulose, and the particles are used as a detergent (Japanese Patent Laid-Open No. 5-221826). . The granulated particles are broken down into fine particles during washing, and are said to have good washing and massage effects.

[0004] However, in the production of such granulated particles, it is difficult to adjust the blending amounts of alkyl cellulose and hydroxyalkyl cellulose as binders in order to obtain particles having desired hardness and disintegration properties. In addition, since these binders are water-soluble, when blended in a skin cleanser or the like and stored for a long period of time, they dissolve out of the particles and the feeling of use of the particles is reduced. Further, in the granulation, in addition to the selection of the type of binder, the use form of the binder, namely, the concentration and viscosity of the binder solution added to the powder, the disintegration of the granulated material,
It is considered that this has an effect on hardness (feel) and the like, but these are not mentioned.

An object of the present invention is to stably exist in a cleaning agent, exhibit a high physical cleaning effect and an appropriate scrub feeling in the initial stage of cleaning, and further, disintegrate particles in the cleaning process and the rinsing process. Accordingly, it is an object of the present invention to provide a method for stably producing disintegrable particles which are excellent in washability and suitable for physical washing without causing skin damage and itching.

[0006]

Means for Solving the Problems In producing particles for physical washing from the primary particles, the present inventors have conducted a desired tumbling granulation of the primary particles with a specific binder solution to obtain a desired hardening. Now, they have found that particles having disintegration properties can be easily and stably produced.

That is, the present invention provides a disintegration method in which primary particles at least partially insoluble in water are stirred and tumbled using a salt-sensitive binder solution having a viscosity of 0.1 to 10.0 Pa · s. It is intended to provide a method for producing conductive particles.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The disintegrable particles of the present invention are particles formed by granulating two or more types of primary particles, at least one of which is water-insoluble, and which is water-soluble in a water-soluble salt-containing aqueous solution. The one in which the aggregation of the granulated product collapses due to the decrease in the salt concentration, that is, the one in which the concentration of the water-soluble salt is low is higher than that in the case where the concentration of the water-soluble salt is high, the higher the collapse ratio.

The primary particles constituting the disintegrable particles of the present invention may be at least partially at least one kind of water-insoluble primary particles. For example, water-insoluble primary particles or a combination of water-insoluble primary particles and water-soluble primary particles can be used. Preferred embodiments from the viewpoint of disintegration include a combination of two or more, more preferably three or more, water-insoluble primary particles, or a combination of these combinations with water-soluble primary particles. These primary particles may be organic particles or inorganic particles.
Here, “water-insoluble” means that when 1 part by weight of a target particle is dissolved in 99 parts by weight of water at 25 ° C., 50% by weight
Is less than 5 in the same condition
It means that 0% by weight or more is dissolved, and the aqueous solution is filtered with filter paper (No. 2), and the determination is made based on the solid content in the filtrate. As the water-soluble primary particles, the solubility is 90% by weight.
The above are preferred.

The following are examples of the water-insoluble primary particles. Examples of the organic particles include polyethylene, polypropylene, polyamide, polyethylene terephthalate, polystyrene and polyurethane or a crosslinked product thereof, sodium poly (meth) acrylate or poly (meth) acrylate or a crosslinked product thereof, and ethylene rubber, Synthetic polymers such as rubbers such as propylene rubber, styrene-butadiene rubber, butadiene rubber, and silicone rubber or cross-linked products thereof; natural polymers such as cellulose or derivatives thereof, chitosan or derivatives thereof, starch, fruit shells, and the like. Derivatives. Among them, polyethylene, polyamide, polystyrene, sodium poly (meth) acrylate, poly (meth) acrylate, cellulose or a derivative thereof, starch and the like are preferably used. Here, “poly (meth) acrylic acid” means both “polyacrylic acid” and “polymethacrylic acid”.

The inorganic particles include, for example, bentonite, talc, mica, kaolin, sepiolite, silica, calcium carbonate, titanium oxide, silicic anhydride, hydroxy calcium apatite, and pearls. Among them, bentonite, talc, mica, kaolin, silica and the like are preferably used.

The following are examples of the water-soluble primary particles. Examples of the organic particles include polyvinyl alcohol or a derivative thereof, an alkali salt of poly (meth) acrylate, an alkali salt of a (meth) acrylic acid / (meth) acrylate copolymer, and an alkali salt of an acrylic acid / maleic acid copolymer. , Polyvinylpyrrolidone and other synthetic polymers; methylcellulose, ethylcellulose, sodium carboxymethylcellulose, hydroxyalkylcellulose, modified starch (hydroxyalkyl-modified starch, phosphate-modified starch, etc.), sucrose, lactose, and other sugars; seaweeds, proteins, etc. Is used.

Examples of the inorganic 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 hydrogen carbonate. . In the case of sodium chloride, commonly sold salt, high-purity purified salt, natural salt and the like are used. Of these, inorganic particles such as sodium chloride, potassium chloride, magnesium chloride, and sodium carbonate are preferred.

These water-soluble and insoluble primary particles are:
The shape may be a true sphere, a substantially sphere, or an irregular shape by pulverization or the like, and hollow or porous particles may also be used.
These primary particles may be used alone or in combination of two or more. The weight ratio of the water-insoluble primary particles to the water-soluble primary particles in the disintegratable particles of the present invention is preferably in the range of (water-insoluble primary particles) / (water-soluble primary particles) = 1/99 to 100/0, and 50/50. ~ 100/0 is more preferred. The average particle diameter of these primary particles measured by a laser diffraction / scattering method is 100 μm or less, more preferably 70 μm.
It is desirable that: Average primary particle size is 10
When the particle size is 0 μm or less, irritation to the skin is particularly low when the disintegrating particles are disintegrated in the washing step and the rinsing step of the object to be washed, and it is preferable in terms of washability.

The salt-sensitive binder solution in the present invention is not particularly limited as long as the binder dissolves in a water-soluble salt aqueous solution by decreasing the salt concentration and precipitates by increasing the salt concentration. Is polyvinyl alcohol or a derivative thereof (for example, carboxylic acid-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, etc.), alkali salt of poly (meth) acrylate, alkali salt of (meth) acrylic acid / (meth) acrylate copolymer ,
Synthetic products such as alkali salts of acrylic acid / maleic acid copolymers and polyvinylpyrrolidone; semi-synthetic polymers such as methylcellulose, ethylcellulose, carboxymethylcellulose salts (eg, sodium salt, potassium salt, etc.), hydroxyalkylcellulose, starch derivatives, etc .; starch , Seaweeds,
Natural polymers such as plant mucilage and protein are used.
Among them, carboxylic acid-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, and carboxymethyl cellulose salt are preferable.

As the carboxylic acid-modified polyvinyl alcohol, modified species include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. Of these, methacrylic acid, maleic acid, and itaconic acid are preferably used. The modification rate is preferably from 0.1 to 8 mol% (molar ratio of the monomer having the modified species in the polyvinyl alcohol composition to the total of vinyl acetate and the modified species) from the viewpoint of the disintegration due to the decrease in salt concentration and the feeling of use. The degree of polymerization is 30
0 to 2500 is preferable, and 500 to 20 is more preferable.
00.

The sulfonic acid-modified polyvinyl alcohol is
It means that a sulfonic acid salt-containing polymer monomer (for example, 2-acrylamido-2-methylpropane sulfonic acid salt) is incorporated in a polyvinyl alcohol skeleton. The modification rate is preferably from 0.1 to 8 mol% from the viewpoint of disintegration due to a decrease in salt concentration and feeling of use. 300-degree of polymerization
2500 is preferred, and more preferably 500-2000.
It is.

In the case of a carboxymethylcellulose salt (an alkali metal salt, an ammonium salt or the like is exemplified as a salt), the degree of etherification (a hydroxyl group substituted by a carboxymethyl group among three hydroxyl groups present in anhydroglucose unit of cellulose) Ratio: a value in the range of 0 to 3.0)
Is 0.2 from the viewpoint of disintegration due to a decrease in salt concentration and feeling of use.
The range of -1.2 is preferable, and the range of 0.3-1.1 is more preferable.

As the salt-sensitive binder, a binder other than carboxylic acid-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, and carboxymethyl cellulose salt may be used in combination. In the disintegrating particles of the present invention, the primary particles and the water-soluble binder may use the same kind of material or different materials.

The salt-sensitive binder is used by dissolving it in water. However, a preservative, an antistatic agent, a plasticizer, a surfactant and the like may be added.

According to the present invention, the primary particles and the salt-sensitive binder solution are agitated and mixed by a granulator equipped with a stirring blade to granulate, and the salt-sensitive binder added during the granulation is used. The viscosity of the solution is 0.1 to 10.0 Pa · s, preferably 0.1 Pa · s.
5 to 8.0 Pa · s, particularly preferably 0.5 to 5.0 P
a · s. By agitating and rolling granulation in this viscosity range, granulation control, uniform dispersion of binder,
Handling is easy, and uniform disintegrable particles having properties such as hardness and disintegration are easily and stably produced.

The viscosity of the salt-sensitive binder solution added at the time of granulation is adjusted by the concentration of the existing solution and / or the temperature. In order to achieve both long-term stability of the produced disintegrable particles in a detergent product and disintegration due to a decrease in the concentration of a water-soluble salt, a salt-sensitive binder solution is used in an amount of 40 to 100 parts by weight of primary particles. It is preferred to choose 80 parts by weight, preferably 45-60 parts by weight. The salt-sensitive binder is preferably selected so as to be 0.5 to 30 parts by weight.

Prior to stirring and tumbling granulation of the disintegrating particles of the present invention, only the primary particles are charged in advance to a stirring and tumbling granulator. In a granulator having a jacket, the jacket temperature is reduced. 5 to 50C, more preferably 10 to 35C,
It is most preferable to stir and mix at a temperature controlled at 15 to 25 ° C. By performing this step, the primary particles are more uniformly dispersed and mixed, and the temperature of the primary particles becomes constant, so that disintegrable particles having stable performance can be obtained regardless of the production time and the difference in batch. Mixing is preferably performed for 3 to 30 minutes, particularly for 5 to 20 minutes, from the viewpoint of uniformity of the composition and temperature of the primary particles and productivity.

The stirring and rolling granulation is preferably performed by adjusting the tip speed of the stirring blade of the granulator to 5 to 40 m / s, particularly 10 to 30 m / s. By doing so, appropriate voids are formed in the granulated disintegrable particles to reduce the consolidation, and at the same time, sufficient aggregation and sizing of the particles can be performed to obtain disintegrable particles having the expected performance.

The stirring and rolling granulation according to the present invention is provided with stirring blades, and the raw material is stirred and rolled and granulated by the stirring blades. For example, a high-speed mixer, a vertical granulator, a Loedige mixer, a Spartan Luiser, a Henschel mixer, a super mixer, a gral, and the like are used.

The specific gravity of the produced collapsible particles is determined by the bulk specific gravity / mass ratio in terms of scrubbing feeling, massage feeling and disintegration during washing.
It is preferable to adjust the value of the true specific gravity so as to be in the range of 0.1 to 0.6, particularly 0.2 to 0.6. Here, the average particle size of the collapsible particles is 1 as measured by a laser diffraction / scattering method.
The thickness is preferably from 00 to 800 μm, preferably from 125 to 600 μm, and particularly preferably from 150 to 360 μm, since a scrub feeling without discomfort when using a skin cleanser, a massage cream or the like can be obtained.

In the present invention, the granulated product produced by stirring and tumbling granulation may be used as it is as collapsible particles, but it is preferable to perform drying. This drying step is preferably performed at a temperature of the disintegrable particles of 100 ° C. or lower, more preferably 80 ° C. or lower, from the viewpoint of the quality of the granulated product, particularly, the prevention of deterioration in solubility accompanying crystallization of the binder. Is preferred.
For drying, a dryer of a stationary type, a rotary type, a fluidized bed type, a vacuum drying type or the like can be used. In particular, a hot-air fluidized-bed dryer is advantageously used because of its advantages such as high productivity and small force applied to the granulated particles.

Next, it is preferable to classify the collapsible particles into collapsible particles having an average particle size and a particle size distribution according to the purpose. Classification can be based on wind classification or vibration screening. Vibrating sieves have a high screening efficiency and require a small number of attached equipment, thus reducing capital investment. Also, among the vibrating sieves, those which perform horizontal (vibrating) movement are suitable because the clogging of the sieve is small even when operated for a long time.

According to the present invention, primary particles at least partially insoluble in water are stirred and tumbled using an aqueous solution of a salt-sensitive binder having a viscosity of 0.1 to 10.0 Pa · s, followed by drying if necessary. Next, classification is performed, and the condition of this step is preferably a combination of each component and a preferable condition in the step.

When the thus produced disintegrable particles are blended in a detergent composition, the disintegrable particles are stably dispersed in the detergent composition without disintegration, and the disintegrable particles in the washing process and the rinsing process are water-soluble. The particles disintegrate as the salt concentration decreases. Taking into account the incorporation into such a detergent composition, the disintegration properties of the disintegrable particles of the present invention can be determined in an aqueous solution having a water-soluble salt concentration of less than 1.0% by weight, more preferably less than 1.5% by weight. It is preferable to select and design a binder so that at least a part thereof is disintegrated. From the viewpoint of rinsing water, the water-soluble salt concentration is further less than 1.0% by weight, more preferably less than 1.5% by weight. More preferably, it is designed such that 70% by weight or more of the collapsible particles before washing (that is, before collapsing) is disintegrated in the aqueous solution.

The disintegrable particles produced according to the present invention include surfactants, oils, thickeners, solvents, wetting agents, coloring agents, preservatives,
In combination with a feel enhancer, a fragrance, an anti-inflammatory, a bactericide, an ultraviolet absorber, etc., for example, a facial cleanser, a whole body cleanser, a skin cleanser such as a solid soap, a shampoo, a dishwashing cleaner, a contact lens cleaner. In addition to toothpaste, it can be widely used as a massage agent for massage cream.

[0032]

Example 1 40 g of corn starch and 60 g of cellulose powder, a total of 300 g of powder, were charged into a stirring granulator (2 L high-speed mixer) and the agitator rotation number was 700.
After mixing at 800 rpm for 20 minutes at a chopper rotation speed of 800 rpm, 5 parts by weight of carboxymethylcellulose-magnesium salt was dissolved in 95 parts by weight of purified water, and 78 g of an aqueous solution (viscosity: 1.7 Pa · s) at a temperature of 30 ° C. for 5 minutes. Was added.
After completion of the addition, the mixture is stirred for 3 minutes and discharged, and 293 g of the granulated substance is discharged.
I got These operations were performed continuously, and tap water at 15 ° C. was passed through the jacket while the stirring blade was rotating.
The obtained granules were dried all day and night with an electric shelf dryer at a setting of 60 ° C. to obtain 223 g of the dried granules. 125-
300 μm particles were collected by a standard sieve to obtain 91 g of disintegrable particles.

Example 2 A total of 3 kg of a powder of 45 parts by weight of cellulose powder and 55 parts by weight of corn starch was charged into a stirring granulator (20 L Henschel mixer), and stirring blades (upper blade: Y1 type, lower blade: A0 type). Was mixed at 1,260 rpm for 20 minutes. An aqueous solution (viscosity: 2.2 Pa · s) at a temperature of 60 ° C. in which 15 parts by weight of polyvinyl alcohol is dissolved in 85 parts by weight of purified water
s) 1.54 kg was added in 10 minutes. Thereafter, the mixture was stirred for 6 minutes and discharged to obtain 2.93 kg of granules. The obtained granules were dried with a hot air dryer at 100 ° C. for 30 minutes to obtain 1.64 kg of dried granules. The dried granulated product was classified by a gyro classifier to obtain 0.63 kg of 132 to 311 μm disintegrable particles.

Example 3 A total of 50 kg of a powder consisting of 45 parts by weight of cellulose powder, 45 parts by weight of corn starch, and 10 parts by weight of synthetic mica was charged into a stirring granulator (500 L super mixer), and stirring blades (upper blade: S type, Lower blade: D type) with rotation speed of 370 rpm
For 20 minutes. 28 kg of an aqueous solution (viscosity: 0.1 Pa · s) at a temperature of 65 ° C. obtained by dissolving 10 parts by weight of polyvinyl alcohol in 90 parts by weight of purified water was added in 12 minutes. The mixture was further stirred for 6 minutes, stirred and granulated, and discharged to obtain 76 kg of a granulated product. The obtained granules were charged into a G1lat fluidized granulation dryer and dried with hot air at 120 ° C. for 56 minutes to obtain 50 kg of dried granules. The dried granules were classified with a gyro classifier to obtain 19.8 kg of 132 to 311 μm disintegrable particles.

Example 4 60 g of corn starch, 10 g of cellulose powder, 30 g of sucrose, and a total of 300 g of powder were charged into a stirring granulator (2 L high speed mixer), and the agitator rotation speed was 700 rpm and the chopper rotation speed was 800 rpm. 2
After mixing for 0 minutes, 72 g of a 30 ° C. aqueous solution (viscosity: 1.3 Pa · s) obtained by dissolving 5 parts by weight of carboxymethylcellulose-magnesium salt in 95 parts by weight of purified water was added to 10 parts.
Added over minutes. After completion of the addition, the mixture was stirred for 6 minutes and discharged to obtain 295 g of a granulated product. Set the obtained granules at 60 ° C
Was dried all day and night with an electric shelf drier of to obtain 225 g of dried granules. 125 to 300 of the dried granules
μm was collected by a standard sieve to obtain 73 g of disintegrable particles.

Example 5 3 kg of cellulose powder was charged into a stirring granulator (20 L Henschel mixer), and stirring blades (upper blade: Y1 type,
(Lower blade: A0 type) was mixed at a rotation speed of 1260 rpm for 20 minutes. Carboxymethyl cellulose-magnesium salt 3
2.46 kg of an aqueous solution (viscosity: 0.4 Pa · s) at a temperature of 25 ° C. in which 97 parts by weight of purified water was dissolved in 97 parts by weight of purified water was added in 10 minutes. Thereafter, the mixture is stirred for 6 minutes and discharged, and the granulated material is 2.9.
5 kg were obtained. The obtained granules are subjected to 10
Dried with hot air of 0 ° C. for 30 minutes, and dried granules 1.6
4 kg were obtained. The dried granules were classified with a gyro classifier to obtain 0.96 kg of 132 to 311 μm disintegrable particles.

Comparative Example 1 3 kg of cellulose powder was charged into a 20 L Henschel mixer as a stirring granulator, and the stirring blade rotation speed was 1260 rp.
and mixed for 20 minutes. In addition, as a stirring blade of the granulator, a Y1 type was used for an upper blade and an A0 type was used for a lower blade. Next, as a binding solution, 2.46 kg of purified water at 25 ° C. was added in 10 minutes. Thereafter, the mixture was stirred for 15 minutes and discharged. As a result, 2.96 kg of a granulated product at a temperature of 38 ° C. was obtained. These operations were performed continuously, and the jacket was cooled by passing tap water at 15 ° C. into the jacket while the stirring blade was rotating. The obtained granules were dried with a hot air fluidizing dryer with hot air at 100 ° C. for 30 minutes to obtain 1.66 kg of dried granules. The dried granules were classified with a gyro classifier, and the resulting 132-
1.20 kg of 311 μm particles were regarded as disintegrable particles.

Test Examples The average particle size, bulk density / true density value, and disintegration rate of the disintegrable particles and the particles produced in Examples and Comparative Examples were measured according to the following measurement methods. Table 1 shows the results.

(1) Average particle size Laser diffraction / scattering type particle size distribution analyzer LA-910
(Horiba Seisakusho Co., Ltd.), and the median diameter was defined as the average particle diameter. The primary particles were dispersed in water, and the disintegrable particles were dispersed in isopropyl alcohol.

[0040] (2) Bulk Density / true density of the values bulk density measurement method JIS K3362 wherein "apparent density measuring instrument" horizontally placed, 125-300 the weighed of the cylindrical container from the funnel
The μm decay particles are allowed to fall naturally. Scrape the raised sample from the container and weigh the container. [Bulk density (g /
L)] = [weight of sample in container (g)] / [volume of container (L)]. True density measuring method 125 g of disintegrable particles having a size of 125 to 300 μm was put into a sample cup and weighed.
05 MICROMERITICS INSTRUME
True density (g / cc) using helium gas by NT
Was measured. Bulk density / true density = bulk density (g / L) ÷ true density (g / cc) ÷ 1000 (L / cc)

(3) Disintegration rate 0.3 g of each disintegrable particle was added to 29.7 g of 0.9% saline solution, and stored in a thermostat at 35 ° C. for 15 hours. Next, 6 g of this sample was weighed on artificial leather, and one more
Cover with a piece of artificial leather and apply 5 g / cm ² load before and after
After reciprocating, the mixture is filtered through a 200-mesh (sieve diameter 74 μm) sieve, and the dry weight of the residue is measured. At this time, the ratio by which the disintegrable particles passed through a 200-mesh sieve was expressed as a percentage by weight, and was defined as a 0.9% saline solution disintegration rate A (%). The same operation was performed using 10% saline, and the 10% saline disintegration rate B
(%). In addition, a 0.9% saline solution disintegration rate B is used as an index of disintegration property at the time of use and at the time of washing off.
Was used as an index of stability in the product.

(4) Method of Measuring Viscosity of Binder Aqueous Solution The viscosity at the binder addition temperature was measured by a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) according to JIS Z8803.

[0043]

[Table 1]

From the results shown in Table 1, all of the disintegrated particles produced according to the present invention exhibited excellent disintegration with decreasing salt concentration.

[0045]

According to the production method of the present invention, the desired disintegrable particles can be easily and efficiently produced by setting the viscosity of the aqueous solution of the salt-sensitive binder within a specific range. The particles have a good disintegration of scrub when used in a skin cleanser or the like.

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Claims (1)

[Claims] 1. A method for producing disintegratable particles, wherein at least a part of water-insoluble primary particles is agitated and tumbled using a salt-sensitive binder solution having a viscosity of 0.1 to 10.0 Pa · s. .