JP2001323095A - Porous cellulose particles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide particles that have proper stimulation to skin and can readily support a variety of functional substances. SOLUTION: The objective porous particles have particle sizes of 0.1-1.0 mm, a plurality of surface pores on a part or the whole part of the outside surface with the maximum open diameter of 1/10-1/3 particle size where the surface open pores are separated from the adjacent pores with partitions of <=20 μm thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to porous cellulose particles.

[0002]

2. Description of the Related Art In recent years, cosmetics containing scrubbing agents have been known as skin cleansing agents and massage agents. Such cosmetics, due to the physical detergency of the scrub,
Waste and sebum generated on the skin surface, dust and oil stains adhering to the skin surface can be efficiently removed.

[0003] Scrub agents which have hitherto been known include the following. (1) Synthetic polymers such as polyethylene and polystyrene, and plants such as walnut hulls and corn cobs, etc. These have a particle size of 50 μm to 1 mm
And its size does not change during use. (2) Several μm to 20 μm depending on a binder such as a water-soluble binder.
m powder into granules of about 200 μm to 2 mm. This gradually decreases during use and eventually disappears. (3) A powder obtained by granulating with a wax or a water-insoluble binder. This gradually diminishes during use, but does not go away.

[0004] The scrub agent of the above-mentioned type (1) has a characteristic that it has a feeling of contact of the particles with the skin, and has a high cleaning effect and a high massage effect, because the particles are present forever during use. However, it has the disadvantage that the stimulation tends to be too intense.

[0005] The scrubbing agent of the above type (2) disappears when used, and is characterized in that it is less irritating to the skin. However, it has a disadvantage that both the cleaning effect and the massage effect tend to be weak.

Further, the above-mentioned type (3) of the scrubbing agent has an appropriate contact feeling to the skin, and has a cleaning effect and a massage effect. Further, since the particles gradually become smaller, the skin is less irritating than the case (1). However, in the production of these granules, there is a disadvantage that the adjustment of hardness is difficult. For example, when granulating powder using wax, a considerable amount of wax must be heated and melted to produce granules,
Furthermore, the hardness of the granules obtained is very high.

[0007] Among the scrubbing agents of the above-mentioned types (1) to (3), biodegradable after use except for those of plant type represented by ground products such as walnut shells and corn cobs. However, there is a problem that it remains in the wastewater forever. Further, as described above, the plant-based scrub agent has a high hardness, and may cause skin damage when used for a long period of time.

On the other hand, as a material having biodegradability and being decomposed in a natural environment after use, a scrub agent of a cellulose material is known.

For example, spherical porous cellulose particles disclosed in JP-A-63-238008 are known. It is characterized by being porous and elastic.

In addition, the substantially columnar particles disclosed in Japanese Patent Application Laid-Open No. 3-106809 have a feature that the ratio of the length to the circular equivalent diameter is 1.1 to 3 and that dirt on the skin is easily removed. .

Further, an inclusion compound of a water-insoluble cyclodextrin polymer and an oily component disclosed in Japanese Patent Application Laid-Open No. 5-105519 is known. This has a stabilizing effect and a sustained release effect on cosmetic ingredients using this clathrate compound.

[0012]

However, the scrub disclosed in JP-A-63-238008 described above retains its original shape when used, and gradually becomes smaller or disappears completely. However, it is not intended to cause skin irritation. In addition, although porous, due to the manufacturing method, the internal pore diameter tends to be small, so when a functional substance is loaded later, those with poor wettability are less likely to enter the pores, and the loading capacity becomes insufficient. .

Further, the scrub agent disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 3-106809 is not intended to be in a form in which it retains its original shape when used, and gradually becomes smaller or disappears completely. Have a strong tendency to irritate the skin. In addition, although it has a certain level of liquid absorption, it is not sufficient, and the ability to carry a functional substance is insufficient.

Further, the scrub agent disclosed in Japanese Patent Application Laid-Open No. 5-105519 retains its original shape when used and does not gradually decrease or disappear completely, so that the skin is strongly irritated. Have a tendency. In addition, since the release rate of the oily component is determined by the combination of the component and cyclodextrin, there is a limitation on the formulation of cosmetics.

Accordingly, an object of the present invention is to provide particles having appropriate skin irritation and capable of easily carrying various functional substances.

[0016]

According to the present invention, there is provided a method for producing a powder having a particle size of 0.1.
1 to 1.0 mm, a plurality of surface openings are provided in part or the whole of the outer surface, and the maximum opening diameter is 1/10 of the above particle size.
The above-mentioned problem was solved by using porous cellulose particles separated by a partition having a thickness of 20 μm or less from the surface opening adjacent to the surface opening.

Since the thickness of the partition wall is equal to or less than a predetermined thickness, the particles are easily deformed when swollen, and can moderately irritate the skin. In addition, since it has surface openings, it is possible to easily carry a functional substance.

[0018]

Embodiments of the present invention will be described below.

The porous cellulose particles according to the present invention are particles having a plurality of surface openings on a part or the whole of the outer surface.

The shape of the porous cellulose particles is not particularly limited, but is preferably spherical. In this case, the spherical shape includes not only a true spherical shape but also a slightly deformed shape such as an elliptical spherical shape.

The particle size of the porous cellulose particles is 0.1.
1 to 1.0 mm is preferable, and 0.15 to 0.8 mm is preferable. If it is less than 0.1 mm, the oil absorbency will be insufficient, and when used in scrubbing agents, the feeling of use will be poor and the cleaning effect will be weak. On the other hand, if it is larger than 1 mm, the oil absorbing property is sufficient, but a rough feeling occurs when used as a scrub agent.

The above-mentioned surface opening refers to an opening having an opening on the outer surface of the porous cellulose particle, and a plurality of the surface openings are provided on a part or the whole of the outer surface of the porous cellulose particle. .

The surface opening and the adjacent surface opening are separated by a partition. The thickness of this partition is preferably 20 μm or less, and more preferably 2 to 10 μm. Partition wall thickness is 20
If it is larger than μm, the number of holes will decrease as a whole,
The oil absorbency is not sufficient, and the porous cellulose particles are less likely to be deformed, resulting in a rough feeling when used as a scrub.

The partition walls may be formed arbitrarily. However, when the partition walls are formed radially along a straight line connecting the central portion and the outer surface of the porous cellulose particles, the formed surface holes become uniform. It is easy to improve oil absorption.

In addition, independent internal pores are formed at the center of the porous cellulose particles. This internal hole may be a single hole formed from the center of the particle to the surface, or may be shielded to be an independent hole. The internal holes can have any shape. Among them, partition walls are formed from the central portion to the outer surface along a straight line connecting the central portion and the outer surface of the porous cellulose particles,
At any position of this partition wall, a transverse partition wall for connecting to an adjacent partition wall may be formed. In this case, a surface opening is formed by each partition on the outer surface side and the transverse partition. With such particles, even if the partition walls become very thin,
The presence of the transverse partition walls is preferable because the strength of the whole particles is maintained.

The maximum opening diameter of the surface openings is preferably 1/10 to 1/3, more preferably 1/8 to 1/4 of the above particle diameter.
When the maximum opening diameter is smaller than 1/10 of the particle diameter, when a functional substance is supported, those having poor wettability are difficult to support. When it is larger than 1/3, the particle shape may not be spherical.

The size of the above-mentioned particle size or opening diameter indicates the largest particle size or opening diameter formed by the particle or opening when they are not a sphere or a circle.

The oil absorption of the porous cellulose particles is determined by the opening diameter of the surface openings and the thickness of the partition walls.

FIGS. 1 and 2 show electron micrographs of such porous cellulose particles. As is clear from FIGS. 1 and 2, the partition walls constituting the surface openings are formed radially from the center of the porous cellulose particles toward the surface.

As shown in FIGS. 1 and 2, the outer surface of the porous cellulose particles may be constituted only by the surface openings and the partition walls. As shown in FIG. A part may be covered with a cellulose dense layer. This dense cellulose layer is a dense layer formed on the particle surface in the production method described later, and cannot be completely removed. The ratio of the area occupied by the remaining dense cellulose layer to the surface area of the particles (hereinafter, referred to as “apparent surface area”) in the case where the above surface openings are not present is preferably 80% or less. If it exceeds 80%, the oil absorbency will be insufficient, and the porous cellulose particles will not be easily deformed, resulting in a rough feeling when used as a scrub.

Further, as long as it has sufficient oil absorbency and does not give a rough feeling when used as a scrub agent, as shown in FIG.
It may be broken.

Next, a method for producing the porous cellulose particles according to the present invention will be described.

First, a porous agent such as carbonate is uniformly mixed and dispersed in an alkali-type cellulose solution such as viscose, and droplets of the mixed dispersion are brought into contact with an acidic solution such as hydrochloric acid to coagulate and regenerate cellulose. And carbonate foaming are performed simultaneously. At this time, if it is desired to obtain fine particles as porous cellulose particles, any method can be used. For example, as disclosed in Japanese Patent Application Laid-Open No. 10-182842, a cylindrical rotating container provided with small holes on the outer peripheral surface is rotated at a high speed, and droplets of the mixed dispersion liquid are scattered from the small holes. There is a method in which the droplet is captured by an acidic solution provided in the surroundings.

The temperature of the acidic solution is not particularly limited, but is preferably 45 to 60 ° C. because foaming is more severe.

The particle size of the porous cellulose particles can be controlled by the size of the small holes of the cylindrical rotating container.
The opening diameter of the surface opening, the thickness and shape of the dense cellulose layer on the outer surface, and the thickness of the partition wall can be controlled by the amount of carbonate added, the concentration of the acidic solution, the bath temperature, and the like. For example, using calcium carbonate as a porogen,
When hydrochloric acid is used as the acidic solution, the amount of calcium carbonate used is 0.3 to 5 parts by weight with respect to 1 part by weight of cellulose, the concentration of hydrochloric acid is 1.3 to 3.2 mol / L, and the liquid temperature of hydrochloric acid is 45 to 60 ° C., and the diameter of the small hole is set to 0.
By setting the thickness to 1 to 1 mm, the dense layer having a predetermined particle size and covering the outer surface of the obtained particles can be made as thin as possible, and the pores serving as surface openings can be adjusted to a predetermined size.

Since the obtained particles have an outer surface covered with a dense layer, an operation of removing the dense layer at the time of the above-mentioned coagulation regeneration or at a subsequent step such as desulfurization, bleaching, or washing with water. At the same time. That is, the particle concentration is 1 /
Vigorous stirring is performed in such a system as to be 3 to 9/10 so that the particles collide with each other. Thereby, part or all of the dense layer on the outer surface can be removed, and the porous cellulose particles according to the present invention can be prepared. In addition,
This dense layer removal step may be performed separately from each of the coagulation regeneration step, desulfurization, bleaching, and water washing.

The obtained porous cellulose particles are rich in water absorption because the material is made of cellulose. In addition, since it has a surface opening having a predetermined size and the partition walls have a predetermined thickness or less, the oil-absorbing property is high. Therefore, porous cellulose particles alone or functional particles carrying a functional substance can be used as various additives such as cosmetics and resins.

Examples of the above-mentioned functional substance include a fragrance, a deodorant, a bactericide, an antibacterial, a humectant, and an adsorbent.
These are not limited to hydrophilic ones, and may be lipophilic ones. In addition to carrying these one type,
Two or more types may be supported.

Further, by coating the surface of the porous cellulose particles with wax or the like, the release rate of the functional substance can be controlled.

The above additives can be used for cosmetics. Examples of the cosmetics include cleansing cosmetics, hair cosmetics, basic cosmetics, makeup cosmetics, aromatic cosmetics, tanning / sunscreen cosmetics, nail cosmetics, eyeliner cosmetics, lip cosmetics, oral cosmetics, bath cosmetics, and the like. Among these, in particular, cosmetic soaps, facial cleansers, hair cleansers, whole body cleansers, cleansing cosmetics such as hand cleansers, and cleansing creams, massage creams,
It is preferably used as a scrub agent to be incorporated in cosmetics such as a keratinizing agent.

The amount of the additive to be added to cosmetics is not particularly limited, but is preferably 1 to 20% by weight. When this scrub agent is blended, uniform mixing and dispersion can be achieved by using a stirrer or a homogenizer.

When the porous cellulose particles are used as a scrub, the particles gradually deform due to friction with the skin during washing or massage. For this reason,
It can reduce skin irritation. In addition, although the shape eventually breaks down, it does not disappear. For this reason, it is possible to provide an appropriate contact feeling to the skin throughout use, and to enhance the cleaning effect and the massage effect.

Further, since the surface has openings, it is excellent in liquid absorbency, and has a smooth touch when rubbed with the skin, and is extremely comfortable. Furthermore, the above-mentioned functional substance can be carried, and the effect of the functional substance can be exhibited in addition to the effect of the scrub agent.

[0044]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to embodiments.

Example 1 Viscose (cellulose concentration 9.5%, ammonium chloride value 7, alkali concentration 5.8)
%) 100 parts by weight, water 12 parts by weight, calcium carbonate 1
4.3 parts by weight were mixed and sufficiently mixed and dispersed at room temperature using a homogenizer to obtain a uniform mixed dispersion.

The resulting mixed dispersion was placed on the side with a diameter of 0.4 m.
m is supplied to the inside of a cylindrical rotating container having a small hole, and the container is rotated to form a droplet from the small hole by centrifugal force, and is discharged into a hydrochloric acid solution having a concentration of 2 mol / L and a liquid temperature of 50 ° C.
Coagulation and regeneration of cellulose and foaming and decomposition of calcium carbonate were performed simultaneously. Further, post-processes of desulfurization, bleaching, and water washing were performed. During coagulation regeneration and post-process,
The particle concentration was set to a volume ratio of 1/2, and the particles were agitated so as to collide with each other vigorously to remove a dense layer of cellulose on the surface and dried with hot air.

As a result, porous cellulose particles as shown in FIG. 1 were obtained. It has a particle size of 0.3-0.5m
m, there is no large part of the dense layer of cellulose on the surface, and the maximum opening diameter of the surface opening is 90 μm (9/50 to 3 /
10), and the thickness of the cellulose partition partitioning the surface opening was 20 μm or less. The internal pores were formed radially from the inside of the particle toward the surface, and were independent of each other. The bulk specific gravity was 0.10 g / ml.

Comparative Example 1 4.8 parts by weight of calcium carbonate was added, and a hydrochloric acid solution having a concentration of 1 mol / L and a liquid temperature of 40 ° C. was used. 1/5, except that stirring was performed slowly.
Porous cellulose particles were produced in the same manner as in Example 1.

As a result, porous cellulose particles as shown in FIG. 5 were obtained. The particle size was 0.3 to 0.5 mm, and as a result of observing the cross section with an electron microscope, the thickness of the partition wall between the pores was 30 μm or more, and a dense cellulose layer was formed on the entire surface. Its bulk specific gravity is 0.20 g /
ml.

(Comparative Example 2) 4.8 parts by weight of calcium carbonate was added, and the obtained mixed dispersion was formed into droplets from a nozzle having a diameter of 1.5 mm, at a concentration of 1 mol / L and a liquid temperature of 50 ° C.
Except that the solution was added dropwise to a hydrochloric acid solution of Example 1, porous cellulose particles were produced in the same manner as in Example 1.

As a result, porous cellulose particles as shown in FIG. 6 were obtained. This particle size is 2.6 to 3.2 mm, and there is no large part of the dense layer of cellulose on the surface, and the maximum opening diameter of the surface opening is 200 μm (1/13 to 1 of the particle size).
/ 16), and the thickness of the partition walls of cellulose partitioning the surface openings was 20 μm or less. The internal pores were formed radially from the inside of the particle toward the surface, and were independent of each other. The bulk specific gravity was 0.10 g / ml.

(Evaluation) (Oil Absorption Test) The particles obtained in Example 1, Comparative Examples 1 and 2, and a granulated product of commercially available crystalline cellulose (particle size: about 0.3
mm, bulk specific gravity 0.93 g / ml, hereinafter referred to as “commercial item”. ) In each 1 g of excess squalane (C ₃₀ H)
₆₂ ) was impregnated for 10 or 60 minutes. Then 7
Centrifugal dewatering was performed at 34 G for 5 minutes. The oil absorption was calculated from the weight increase at that time. Table 1 shows the results.

[0053]

[Table 1]

As a result, the particles of Example 1 were superior in oil absorbency to those of Comparative Example 1, Comparative Example 2 or commercially available products. This is because the particles of Example 1 did not have most of the dense layer of cellulose on the surface, and the size of the maximum opening diameter was 9/50 to 3/10 of the particle size.
And the maximum thickness of the partition wall that separates the surface openings is 20 μm
This is because it is considered that the oil absorption capacity is high because of the following.
In addition, since the amount of the carrier is larger than that of the others, it is considered to be very useful as an adsorption carrier.

On the other hand, in Comparative Example 1, since there is no surface opening, the oil does not easily penetrate into the inside. In Comparative Example 2, the particle size is large and the maximum opening of the surface opening is large. Since the diameter is 1/13 to 1/16 of the particle diameter, which is smaller than that of Example 1, it is considered that the oil hardly penetrates into the inside of the particles.

(Cosmetic Addition Test) (1) Particles Used The particles of Example 1 were used as a scrub agent (hereinafter referred to as “scrub agent”).
"Scrub agent 1"). A fragrance (D-limonene) was supported on the particles of Example 1 at a weight ratio of 1: 1. The particles were used as a scrub agent (hereinafter, referred to as "scrub agent 2"). -The particles of Comparative Example 1 were used as a scrub agent (hereinafter, referred to as a scrub agent)
"Comparative scrub agent 1").・ Also, walnut shell grains (irregular shaped, particle size 0.3 to 0.
5 mm) was used as a scrub agent (hereinafter, referred to as a scrub agent).
"Comparative scrub agent 2").

(2) Production of liquid detergent Potassium laurate, potassium myristate, glycerin, propylene glycol, hydroxypropylcellulose and coconut oil fatty acid diethanolamide were added to ion-exchanged water at the ratio shown in Table 2, and the mixture was heated at 60 ° C. Heated and dissolved.
Then, add ethylene glycol distearate,
Further, each of the above scrubbing agents was uniformly mixed. This is 3
The mixture was cooled to 0 ° C. to obtain a white and opaque liquid detergent containing a scrubbing agent. Further, a liquid cleaning agent not containing the scrubbing agent was prepared.

[0058]

[Table 2]

(3) Intensity of skin irritation A small amount of the above liquid detergent was applied to the palms and backs of the five panelists, and rubbing was performed with fingers. At this time,
The evaluation was performed according to the following three-level criteria, and the evaluation that was the most frequent among the five persons was taken as the test result. The results are shown in Table 3. ：: Soft touch and moderate stimulus at the same time and comfortable ：: Tendency of strong stimulus, slightly uncomfortable ：: Stimulus too strong and painful.

(4) Cleaning Effect The following model sebum colored with carbon black was applied to the palms of five panelists (2 mg / cm ² ).
After drying, the above-mentioned liquid cleaning agent was applied, friction cleaning with a finger was performed, followed by washing with water and drying, and the degree of model sebum remaining on the palm was observed with a stereoscopic microscope. At this time,
Evaluation was performed according to the following criteria, and the evaluation that was the most frequent among the five persons was taken as the test result. The results are shown in Table 3. ：: Dirt on skin details was almost removed. ×: Dirt removal on skin details was insufficient.

As model sebum, squalene 8% by weight, myristyl myristate 14% by weight, cottonseed oil 7.
2% by weight, cholesterol 12.0% by weight, cholesterol palmitate 4% by weight, lauric acid 0.8% by weight,
A mixture of 6.4% by weight of myristic acid, 24.8% by weight of palmitic acid, 4.8% by weight of stearic acid and 18.0% by weight of oleic acid was used.

[0062]

[Table 3]

Results Although Comparative Scrub Agent 1 and Comparative Scrub Agent 2 were excellent in detergency, the feeling on the skin tended to be strong or too strong. When no scrub was used, the cleaning power was insufficient.

On the other hand, the scrubbing agent 1 and scrubbing agent 2 have a sufficient ability to remove dirt, and have a soft and moderate irritating feeling to the skin throughout use. In addition, in the case where the scrub agent 2 was used, in addition to the above characteristics, the scrub agent itself supported the fragrance at a high concentration, and a fresh aroma was felt during use.

[0065]

According to the present invention, when porous cellulose particles are used as a scrub, the particles gradually deform due to friction with the skin during washing or massage. Therefore, irritation to the skin can be reduced. In addition, although the shape eventually breaks down, it does not disappear. Therefore, it is possible to provide an appropriate feeling of contact with the skin throughout use, and to enhance the cleaning effect and the massage effect.

Further, since the surface has openings, it has excellent liquid absorbency, has a smooth feel when rubbing against the skin, and is extremely comfortable.

Further, since the surface has openings, the above-mentioned functional substance can be carried, and the effect of the functional substance can be exhibited.

[Brief description of the drawings]

FIG. 1 is an electron micrograph (magnification: 180 times) showing an example of a porous cellulose particle according to the present invention.

FIG. 2 is an electron micrograph of a part of FIG. 1 (magnification: 400 times).

FIG. 3 is an electron micrograph (magnification: 180 times) showing an example of another porous cellulose particle.

FIG. 4 is an electron micrograph (magnification: 200 times) showing an example of another porous cellulose particle.

FIG. 5 is an electron micrograph (magnification: 180 times) showing the porous cellulose particles obtained in Comparative Example 1.

FIG. 6 is an electron micrograph (magnification: 25 times) showing the porous cellulose particles obtained in Comparative Example 2.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08B 1/00 C08B 1/00 C11B 9/00 C11B 9/00 Z // C08L 1:00 C08L 1:00 (72) Inventor Yasuo Morimoto 1-8-10 Jiyugaoka, Kanazu-cho, Sakai-gun, Fukui Prefecture Rengo Co., Ltd. Fukui Research Laboratory (72) Inventor Saito Hidenao 1-8-10, Jinugaoka, Kanazu-cho Sakai-gun, Fukui Prefecture Fukui Research Laboratory F Terms (reference) 4C083 AC122 AC242 AC392 AC642 AD261 AD262 AD282 BB21 CC23 DD23 DD31 FF01 4C090 AA01 AA09 BA24 BB12 BB52 BB92 BD25 DA05 DA26 4F074 AA02 BA02 BA07 DA53 DA59 4H011 AA02 BA01 BC18 BC19 DA13 DH10 4DA

Claims (6)

[Claims] 1. A particle having a diameter of 0.1 to 1.0 mm, a plurality of surface openings provided on a part or the entire outer surface, and a maximum opening diameter of which is 1/10 to 1/3 of the particle diameter. Wherein the surface openings adjacent to the surface openings are porous cellulose particles separated by partition walls having a thickness of 20 μm or less. 2. The porous cellulose particles according to claim 1, wherein the partition walls are radially formed along a straight line connecting a central portion and an outer surface. 3. The porous cellulose particles according to claim 1, wherein independent internal pores are formed in a central portion. 4. A functional particle in which a functional substance is supported on the porous cellulose particle according to claim 1. 5. The functional particles according to claim 4, wherein the functional substance is one or more selected from fragrances, deodorants, bactericides, antibacterial agents, humectants, and adsorbents. 6. A cosmetic comprising the porous cellulose particles according to claim 1 or the functional particles according to claim 4 or 5.