JP7478204B2 - Cellulose composite powder - Google Patents

Description

The present invention relates to a cellulose composite powder that has an excellent skin feel.

Cellulose powder is a naturally derived raw material, highly safe, and has a soft feel, and is therefore used as a cosmetic ingredient. However, most cellulose powders are made by mechanically grinding fibrous materials such as wood pulp, and have a fibrous or irregular shape, which makes them less smooth on the skin.
Cellulose particles having a spherical shape have been produced by various methods, such as those described in Patent Document 1, and are in use, but they have not been satisfactory in terms of skin sensation.
Furthermore, for example, Patent Document 2 describes a microcrystalline cellulose powder that is characterized by being surface-treated by adding cellulose to an aqueous solution of metal soap or hydrogenated lecithin. Although the water- and oil-repellency are improved, the skin sensation is not satisfactory.

Japanese Patent Application Laid-Open No. 11-181147 JP 2003-146829 A

The present invention aims to provide a cellulose composite powder that has a good skin feel.

As a result of extensive research into achieving the above-mentioned objective, the inventors of the present application discovered that a cellulose composite powder exhibiting specific physical properties can produce a cellulose powder with a good skin feel, and thus arrived at the present invention.

That is, the cellulose complex powder of the present invention is a cellulose complex powder containing a cellulose-based substance, having an average particle size of 1 to 100 μm, and in a shear test based on JIS-Z8835, the shear adhesion strength _C30 of the powder layer at a vertical pressure of 30 MPa is more than 0 kPa and not more than 5 kPa, and the value ( _C30 / _C10 ) obtained by dividing the shear adhesion strength _C30 of the powder layer at a vertical pressure of 30 MPa by the shear adhesion strength _C10 of the powder layer at a vertical pressure of 10 MPa in the shear test is more than 0 and not more than 4.

The cellulose composite powder of the present invention preferably has a circularity of 0.4 to 1.0.

The cellulose composite powder of the present invention preferably has an oil absorption of 20 to 200 ml/100 g.

The cellulose composite powder of the present invention preferably has a powder compound attached to the surface of the cellulose-based material.

In the cellulose composite powder of the present invention, the powder compound preferably has an alkyl group having 2 to 30 carbon atoms and/or two or more methyl groups.

In the cellulose composite powder of the present invention, it is preferable that the powder compound has at least one functional group selected from a hydroxyl group, a primary to tertiary amino group, a carboxyl group, a carboxyl base, a phosphate group, a phosphate base, a phosphorylcholine group, a sulfonic acid group, and a silyl group.

In the cellulose complex powder of the present invention, the weight ratio of the powder compound to the cellulose complex powder is preferably 0.1 to 20% by weight.

The method for producing a cellulose complex powder of the present invention is a method for producing the above-mentioned cellulose complex powder, and includes a step of dry-blending a powder containing a cellulose-based material and a powder compound, and a step of mechanochemically treating the powder.

It is preferable that the method for producing a cellulose composite powder further includes a step of mechanically grinding the powder compound.

The cellulose composite powder of the present invention has a good skin feel.

1 is an electron microscope photograph of cellulose composite powder 1 obtained in Example 1.

[Cellulose composite powder]
The cellulose complex powder of the present invention is a cellulose complex powder containing a cellulose-based substance, having an average particle size of 1 to 100 μm, and in a shear test based on JIS-Z8835, the shear adhesion C ₃₀ (hereinafter sometimes simply referred to as C ₃₀ ) of the powder layer at a vertical pressure of 30 MPa is more than 0 kPa and not more than ₅ kPa, and the value (C ₃₀ /C 10 ) (hereinafter sometimes simply referred to as C ₃₀ /C ₁₀ ) obtained by dividing the shear adhesion C ₃₀ of the powder layer at a vertical pressure of 30 MPa by the shear adhesion C ₁₀ of the powder layer at a vertical _pressure of 10 MPa is more than 0 and not more than 4.

If the average particle size of the cellulose composite powder is less than 1 μm, the slipperiness and smoothness will be poor. On the other hand, if it exceeds 100 μm, the powder will feel rough and will be less smooth. The average particle size of the cellulose composite powder is preferably 1 to 50 μm, more preferably 1 to 40 μm, even more preferably 1 to 30 μm, and particularly preferably 1 to 20 μm. The method for measuring the average particle size of the cellulose composite powder is the method used in the examples.

The shear adhesion indicates the adhesion between powder particles, and a larger value of the shear adhesion indicates a stronger adhesion. C ₃₀ indicates the adhesion between powder particles when the powder layer is compressed under a pressure of 30 MPa.
If _C30 exceeds 5 kPa, adhesion is strong under pressure and slippage is poor. _C30 is preferably from 0 kPa to 4 kPa, more preferably from 0 kPa to 3 kPa, and even more preferably from 0 kPa to 2 kPa.

_C10 indicates the adhesion between powder particles when the powder layer is compressed under 10 MPa. A large difference from _C30 means that the powder is significantly affected by pressure.
If _C30 / _C10 exceeds 4, the rubber will feel squeaky and the feel will be poor. _C30 / _C10 is preferably more than 0 and not more than 3, more preferably more than 0 and not more than 2.5, even more preferably more than 0 and not more than 2, and particularly preferably more than 0 and not more than 1.5. The methods for measuring _C30 and _C10 are the same as those described in the Examples.
The cellulose composite powder having the above average particle size, _C30 of more than 0 kPa and not more than 5 kPa, and _C30 / _C10 of more than 0 and not more than 4, when applied to the skin, provides a moderate moist feeling, smoothness and softness on the skin, has little squeaking feeling, and is excellent in skin sensation.

The circularity of the cellulose complex powder of the present invention is not particularly limited, but is preferably 0.4 to 1.0. If the circularity is less than 0.4, the shape may be irregular and the degree of flatness may be too high, resulting in poor smoothness on the skin. The circularity of the cellulose complex powder is more preferably 0.5 to 1.0, even more preferably 0.55 to 1.0, and particularly preferably 0.6 to 1.0. The method for measuring the circularity of the cellulose complex powder is the method described in the Examples.
The shape of the cellulose composite powder is not particularly limited, and examples thereof include granular, spherical, elliptical, round, lump, scale-like, plate-like, fibrous, flat, bowl-like, convex or concave lens-like, and among these, spherical, elliptical, round, and convex lens-like shapes are preferred in terms of excellent slip properties.

The oil absorption of the cellulose complex powder of the present invention is not particularly limited, but is preferably 20 to 200 ml/100 g in terms of achieving the effects of the present application. If the oil absorption is outside the above range, the skin sensation may be poor. The lower limit of the oil absorption of the cellulose complex powder is more preferably 30 ml/100 g, even more preferably 40 ml/100 g, particularly preferably 50 ml/100 g, and most preferably 60 ml/100 g. On the other hand, the upper limit of the oil absorption of the cellulose complex powder is more preferably 180 ml/100 g, even more preferably 160 ml/100 g, particularly preferably 140 ml/100 g, and most preferably 120 ml/100 g. The method for measuring the oil absorption of the cellulose complex powder is the method used in the examples.

The cellulose complex powder of the present invention essentially contains a cellulose-based material and exhibits the above-mentioned physical properties.
The cellulosic material is a material essentially containing cellulose, and preferably contains 50 to 100% by weight of cellulose, more preferably 60 to 100% by weight, even more preferably 70 to 100% by weight, particularly preferably 80 to 100% by weight, and most preferably 90 to 100% by weight.
Examples of cellulose include natural cellulose derived from wood, cotton, hemp, bamboo, etc., and regenerated or refined cellulose. These cellulose raw materials can be pulverized into fine powder by crushing or cutting. For crushing, for example, a ball mill, a vibration mill, a cutter mill, a hammer mill, a Wheeler mill, a jet mill, an extruder, a mortar-type grinder, etc. are used. Among the above celluloses, fibrous or powdery cellulose obtained by refining wood pulp derived from wood is preferred.
In addition, cellulose obtained by further pulverizing a water slurry of kraft pulp into fine fibers using a Dyno Mill or the like, or commercially available nanocellulose granulated by spray drying or the like may also be used.
Furthermore, regenerated cellulose obtained by dissolving a cellulose raw material may be used. For example, cellulose particles may be obtained by dropping viscose in a granular form into a coagulation and regeneration bath to coagulate and regenerate the cellulose.
The cellulose may be modified with a carboxyl group, a phosphoric acid group, an amino group, or the like.

The cellulose-based material may contain, in addition to cellulose, at least one selected from a surfactant, an organic substance, and an inorganic substance.

The surfactant is not particularly limited, but examples thereof include anionic surfactants such as fatty acid salts, alkyl sulfate salts, alkyl ether carboxylate salts, alkyl ether sulfate salts, alkyl phosphate salts, polyoxyalkylene alkyl ether acetate salts, alkylbenzene sulfonates, polyoxyalkylene alkyl ether sulfate salts, higher fatty acid amide sulfonates, higher fatty acid alkali metal salts, alkyl phosphate salts, polyoxyalkylene alkyl ether phosphate salts, long-chain sulfosuccinate salts, and N-acylamino acid salts; cationic surfactants such as quaternary ammonium salts and alkylamine salts; polyoxyalkylene oxide-added alkyl ethers, polyoxyalkylene styrenated phenyl ethers, and mixtures of polyhydric alcohols and monohydric fatty acids. Examples of such surfactants include nonionic surfactants such as ester compounds with fatty acids, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene fatty acid esters, polyoxyalkylene sorbitan fatty acid esters, glycerin fatty acid esters, PEG-hydrogenated castor oil, polyoxyalkylene castor oil, polyoxyalkylene hydrogenated castor oil, higher fatty acid PEG glyceryls, higher fatty acid sorbitans, polyoxyalkylene sorbitol fatty acid esters, polyglycerin fatty acid esters, alkyl glycerin ethers, polyoxyalkylene cholesteryl ethers, alkyl polyglucosides, sucrose fatty acid esters, and polysorbates; amphoteric surfactants such as amino acid-based, betaine-type, hydrogenated lecithin, and lecithin; and silicone-based surfactants such as dimethicone. The above surfactants may be used alone or in combination of two or more.

The organic substances are not particularly limited, but examples thereof include waxes such as carnauba wax, candelilla wax, higher alcohols, higher fatty acids, synthetic waxes, and paraffin; oils such as almond oil, olive oil, rice bran oil, squalane, silicone oil, mineral oil, and alkyl benzoate. The above organic substances may be used alone or in combination of two or more kinds.

The inorganic substances are not particularly limited, but examples thereof include wollastonite, sericite, kaolin, mica, clay, talc, bentonite, alumina silicate, pyrophyllite, montmorillonite, calcium silicate, calcium carbonate, magnesium carbonate, dolomite, calcium sulfate, boron nitride, silicon carbide, silica, alumina, mica, titanium dioxide, zinc oxide, magnesium oxide, zinc oxide, and hydrosaltite. The above inorganic substances may be used alone or in combination of two or more.

When the cellulose-based material contains at least one selected from a surfactant, an organic substance, and an inorganic substance, at least one selected from a surfactant, an organic substance, and an inorganic substance can be mixed and contained in the cellulose-based material when the cellulose is pulverized and/or granulated.

The cellulose complex powder of the present invention is preferably one that contains the above-mentioned cellulose-based material and a powdered compound in order to achieve the effects of the present application. Furthermore, it is preferable that the cellulose complex powder has the powdered compound attached to the surface of the cellulose-based material.

In terms of achieving the effects of the present application, the powder compound preferably has an alkyl group having 2 to 30 carbon atoms and/or two or more methyl groups. The alkyl group having 2 to 30 carbon atoms may have a linear structure or a branched structure.
The alkyl group preferably has 2 to 25 carbon atoms, more preferably 2 to 20 carbon atoms, and even more preferably 2 to 15 carbon atoms.

Examples of powder compounds include, but are not limited to, hydrophobic silica such as dimethylsilylated silica, trimethylsilylated silica, octylsilylated silica, and dimethylpolysiloxane silica; fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, and cerotic acid; calcium laurate, zinc laurate, potassium laurate, zinc myristic acid, sodium myristic acid, zinc palmitate, sodium stearate, magnesium stearate, zinc stearate, calcium stearate, aluminum stearate, calcium 12-hydroxystearate, zinc 12-hydroxystearate, magnesium 12-hydroxystearate, aluminum 12-hydroxystearate, calcium behenate, zinc behenate, magnesium behenate, calcium montanate, zinc montanate, magnesium montanate, aluminum montanate, fatty acid metal salts such as glyceride palmitate, myricyl cerotenate, myricyl palmitate, cetyl palmitate and other waxes; sodium N-coconut oil fatty acid acyl-L-glutamate, sodium N-lauroyl-L-glutamate, potassium N-myristoyl-L-glutamate, sodium N-myristoyl-L-glutamate, sodium N-acyl-L-glutamate, sodium N-stearoyl-L-glutamate, sodium N-lauroyl-L- Examples of such substances include amino acid-based substances such as glutamic acid, N-stearoyl-L-glutamic acid, N-lauroyl-L-arginine, N-lauroyl-L-lysine, N-hexanoyl-L-lysine, N-oleyl-L-lysine, N-palmitoyl-L-lysine, N-stearyl-L-lysine, N-hexanoyl-L-lysine, N-myristenoyl-L-lysine, N-capryloyl-L-lysine, and N-decanoyl-L-lysine; and complex lipids such as phospholipids and glycolipids. The above powder compounds may be used alone or in combination of two or more kinds.

The powder compound preferably has at least one functional group selected from a hydroxyl group, a primary to tertiary amino group, a carboxyl group, a carboxylate group, a phosphate group, a phosphorylcholine group, a sulfonate group, and a silyl group, and more preferably has two or more functional groups selected from the above functional groups.

In terms of achieving the effects of the present invention, it is preferable that the powder compound is a powder compound having an alkyl group having 2 to 30 carbon atoms and/or two or more methyl groups and further having the above-mentioned functional group.
Among the above powder compounds, for example, amino acid substances are preferred, N-lauroyl-L-lysine and N-capryloyl-L-lysine are more preferred, and N-lauroyl-L-lysine is particularly preferred.

The content of the powder compound in the cellulose complex powder is not particularly limited, but is preferably 0.1 to 20% by weight. If the content of the powder compound is outside the above range, the effect of the present application may not be fully obtained. The lower limit of the content of the powder compound in the cellulose complex powder is more preferably 1% by weight, even more preferably 3% by weight, and particularly preferably 4% by weight. On the other hand, the upper limit of the content of the powder compound in the cellulose complex powder is more preferably 15% by weight, even more preferably 12% by weight, and particularly preferably 10% by weight.

It is preferable that the cellulose composite powder has water floating property that satisfies the following condition 1, since this can improve the sliding property between the powder particles.

Condition 1: After shaking a 5% aqueous dispersion of cellulose composite powder and leaving it to stand at 25°C for 12 hours, the proportion of floating matter that rises to the water/air interface is 50-100% by weight relative to 100% by weight of the cellulose composite powder contained in the 5% aqueous dispersion.

The amount of the floating matter is more preferably 70 to 100% by mass, and even more preferably 80 to 100% by mass. The percentage of the floating matter is determined by the method described in the examples.

[Method for producing cellulose composite powder]
The method for producing the cellulose composite powder of the present invention may be a conventionally known method as long as it can produce the above-mentioned cellulose composite powder, and examples of such methods include a wet method using a solvent, a dry method in a gas phase, a mechanochemical method involving mechanical mixing and grinding or shearing, etc. Among these, in terms of achieving the effects of the present application, a method for producing by dry blending using a dry method in a gas phase, a mechanochemical method involving mixing and grinding or shearing, etc. is preferred, and it is more preferred to include a step of dry blending a powder containing a cellulose-based material and a powder compound, and a step of mechanochemical treatment.
It is also preferable that the method further comprises the step of mechanically crushing the powder compound.

Examples of devices for producing the cellulose composite powder of the present invention include ball mills, bead mills, vibration mills, cutter mills, hammer mills, Wheeler mills, jet mills, extruders, and mortar-type grinders.

In the method for producing a cellulose composite powder, when the method includes a step of mechanochemically treating a powder containing a cellulose-based material and a powder compound, the average particle size of the cellulose-based material used is preferably 1 to 100 μm, more preferably 1 to 50 μm, even more preferably 1 to 40 μm, and most preferably 1 to 30 μm.
The powder compound used preferably has an average particle size of 1 nm to 500 μm, more preferably 1 nm to 300 μm, even more preferably 1 nm to 200 μm, and most preferably 1 nm to 100 μm. In the process of producing the cellulose composite powder, the powder compound is preferably pulverized to 1 μm or less in order to obtain the effects of the present application.

The cellulose complex powder of the present invention has excellent skin sensation and can be suitably used as a cosmetic. When it is used by blending it in a cosmetic, it can be used in combination with known cosmetic ingredients according to a conventional method. Examples of cosmetic ingredients include oils, surfactants, alcohols, water, moisturizers, gelling agents, thickeners, powders other than the cellulose complex powder of the present invention, ultraviolet absorbers, preservatives, antibacterial agents, antioxidants, functional ingredients, etc.
Cosmetics containing the cellulose complex powder of the present invention may be in the form of powder, solid, cream, gel, liquid, mousse, spray, etc.
The amount of the cellulose complex powder of the present invention to be blended in a cosmetic is not particularly limited, but is preferably 0.1 to 50% by weight, more preferably 0.5 to 30% by weight, and even more preferably 1 to 20% by weight.

Below, examples of the cellulose complex powder of the present invention are specifically described. Note that the present invention is not limited to these examples. In addition, the physical properties of the cellulose complex powders of the examples and comparative examples were evaluated as follows.

[Average particle size]
A laser diffraction particle size distribution analyzer (Mastersizer 3000, manufactured by Malvern) was used as the measuring device, and the measurement was performed by a dry measurement method. The average particle size was measured using the D50 value based on volume standard measurement.

[Shear adhesion evaluation]
Based on JIS-Z8835 (method of measuring critical state line (CSL) and wall yield line (WYL) by single shear test), the measurement was performed by a rotational cell type constant volume method using a shear type powder flowability tester (Volution Powder Tester, manufactured by Mercury Scientific).
The measurement samples (powder) used had a moisture content of 10% or less. The moisture content was measured by an infrared moisture meter method.
The collapse behavior of the powder bed at a vertical pressure of 30 MPa and a vertical pressure of 10 MPa was measured, and the shear adhesive strength C ₃₀ of the powder bed at a vertical pressure of 30 MPa and the shear adhesive strength C ₁₀ of the powder bed at a vertical pressure of 10 MPa were determined.
Further, from the obtained C ₃₀ and C ₁₀ , the value obtained by dividing C ₃₀ by C ₁₀ (C ₃₀ /C ₁₀ ) was calculated.

[Measurement of circularity]
The particle size was measured by image analysis using a particle analysis imaging device (Morphologi G3, manufactured by Malvern).

[Measurement of oil absorption]
The oil absorption was measured according to the method for measuring oil absorption specified in JIS-K5101, using oleic acid as the oil.

[Evaluation of floatability in water]
10 g of cellulose composite powder and 200 g of water were placed in a 500 ml separatory funnel, shaken up and down 20 times, and then left to stand at 25°C for 12 hours. The lower layer (aqueous dispersion) was removed from the bottom, and the floating matter that had risen to the water/air interface was removed from the top. 200 g of water was added to the funnel, and the above process was repeated. The floating matter was dried at 80°C until the moisture content was 10% or less, and the weight after drying was measured. The ratio of the floating matter that had risen to the water/air interface was calculated using the following formula (1).
Percentage of floating matter = (weight of separated upper layer after drying/10 g) x 100 (%) (1)
The moisture content of the cellulose composite powder was measured by an infrared moisture meter method.

[Skin sensation evaluation]
Five panelists evaluated the powdery feel of each powder applied to the skin in four areas: moist feeling, slipperiness, softness, and squeaky feeling, on a scale of 1 to 5. The evaluation criteria for each evaluation item were as follows:
Moist feeling: The higher the value, the more moist the feeling.
Slipperiness: The higher the value, the better the slipperiness is felt.
Softness: The higher the value, the softer it feels.
Squeakiness: The higher the number, the less creaking you feel.
For each item, the average of the evaluation results of each panelist was calculated, and the higher the average value, the better the skin sensation was evaluated. In addition, the average of the results of the four items was calculated, and the higher the average value, the better the balance of the powder in terms of skin sensation was evaluated.

Comparative Example 1
Solubilized starch was added to 250 g of 6% sodium hydroxide while stirring to obtain a 23% starch solution. 80 g of viscose was added to this and stirred at room temperature to prepare a microdispersion of viscose. Sulfuric acid was added to this microdispersion to coagulate and regenerate cellulose. The obtained regenerated cellulose was separated by a glass filter and washed with water to obtain cellulose microparticles A. The average particle size of the obtained cellulose microparticles A was 10.0 μm, C ₃₀ was 3.1 kPa, and C ₃₀ /C ₁₀ was 4.2. In addition, the circularity was 0.95, the oil absorption was 60 ml/100 g, and the amount of floating matter relative to water was 0%. In the skin sensation evaluation, the moist feeling was 2, the slipperiness was 3.6, the softness was 2.4, and the creaky feeling was 2. Although the slipperiness was relatively good, the values were low in other evaluation items, and the skin sensation was poor. The total balance result of each evaluation item was 2.5, and the balance was poor in terms of powdery feeling.

Example 1
20 g of the cellulose microparticles A of Comparative Example 1 and 2 g of N-lauroyl-L-lysine powder (average particle size 19.0 μm) were mixed and placed in a 500 ml sealed container together with 200 g of 3 mm zirconia balls, and crushed and composited in a planetary ball mill at a rotation speed of 200 rpm for 1 hour to obtain cellulose composite powder 1.
A scanning electron microscope photograph of the obtained cellulose complex powder 1 is shown in FIG.
The average particle size of the obtained cellulose composite powder 1 was 10.0 μm, _C30 was 1.3 kPa, and _C30 / _C10 was 1.4. The circularity was 0.95, the oil absorption was 60 ml/100 g, and the amount of floating matter in water was 95%. In the skin sensation evaluation, the moist feeling was 4.8, the slipperiness was 5, the softness was 4.4, and the squeaky feeling was 5. The values were high in all evaluations, and the results were excellent in skin sensation. The total balance result of each evaluation item was 4.8, and the results were excellent in balance in terms of powder feeling.

Comparative Example 2
Using a collision plate type jet mill, cellulose powder derived from refined wood pulp (particle size: 90% or more passing through 100 mesh) was pulverized at a pressure of 0.6 MPa and a supply rate of 2 kg/h to obtain cellulose powder B.
The average particle size of the obtained cellulose powder B was 22.0 μm, C ₃₀ was 12 kPa, and C ₃₀ /C ₁₀ was 3.4. The circularity was 0.70, the oil absorption was 160 ml/100 g, and the amount of floating matter in water was 0%. In the skin sensation evaluation, the moist feeling was 1, the slipperiness was 1, the softness was 2.4, and the squeaky feeling was 1. The values were low in all evaluation items, and the skin sensation was poor. The total balance result of each evaluation item was 1.4, and the powdery feeling was poorly balanced.

Example 2
The same procedure as in Example 1 was carried out except that the cellulose powder B was used instead of the cellulose fine particles A, to obtain a cellulose composite powder 2.
The average particle size of the obtained cellulose composite powder 2 was 18.0 μm, _C30 was 3.5 kPa, and _C30 / _C10 was 1.9. The circularity was 0.63, the oil absorption was 100 ml/100 g, and the amount of floating matter in water was 86%. In the skin sensation evaluation, the moist feeling was 3.8, the slipperiness was 3.6, the softness was 4.4, and the squeaky feeling was 3.8. The values were high in all evaluations, and the results were excellent in skin sensation. The total balance result of each evaluation item was 3.9, and the results were excellent in balance in terms of powder feeling.

Comparative Example 3
The same procedure as in Example 2 was carried out except that the grinding time was changed to 12 hours, and thus cellulose composite powder 3 was obtained.
The obtained cellulose composite powder 3 had an average particle size of 12.0 μm, C ₃₀ of 1.5 kPa, and C ₃₀ /C ₁₀ of 4.3. The circularity was 0.38, the oil absorption was 130 ml/100 g, and the amount of floating matter in water was 100%. In the skin sensation evaluation, the moist feeling was 4.2, the slipperiness was 2.4, the softness was 3.6, and the squeaky feeling was 2. The moist feeling was excellent, but the values for the slipperiness and squeaky feeling were low, resulting in an inferior skin sensation. The total balance result of each evaluation item was 3.1, resulting in a poor balance in terms of powdery feeling.

Example 3
Cellulose powder B (400 g) and dimethylsilylated silica powder (20 g, average primary diameter 16 nm) were placed in a 5 L ball mill together with 2 L of 50 mm alumina balls and milled and composited at 30 rpm for 12 hours to obtain cellulose composite powder 4.
The average particle size of the obtained cellulose composite powder 4 was 20.0 μm, _C30 was 1.6 kPa, and _C30 / _C10 was 2.9. The circularity was 0.68, the oil absorption was 70 ml/100 g, and the amount of floating matter in water was 90%. In the skin sensation evaluation, the moist feeling was 4.6, the slipperiness was 4.4, the softness was 4, and the squeaky feeling was 4.6. The values were high in all evaluations, and the results were excellent in skin sensation. The total balance result of each evaluation item was 4.4, and the results were excellent in balance in terms of powder feeling.

Comparative Example 4
The same procedure as in Example 3 was carried out except that the grinding time was changed to 1 hour, and Cellulose composite powder 5 was obtained.
The average particle size of the obtained cellulose composite powder 5 was 22.0 μm, _C30 was 10 kPa, and _C30 / _C10 was 3.3. The circularity was 0.70, the oil absorption was 140 ml/100 g, and the amount of floating matter in water was 10%. In the skin sensation evaluation, the moist feeling was 1, the slipperiness was 1.2, the softness was 2.2, and the squeaky feeling was 1. The values were low in all evaluation items, and the results were poor in skin sensation. The total balance result of each evaluation item was 1.4, and the results were poor in balance in terms of powdery feeling.

The cellulose complex powder of the present invention has a good skin sensation and can be used in cosmetics such as powder cosmetics, solid cosmetics, liquid cosmetics, cream cosmetics, and spray cosmetics. In addition, because it has low coagulation tendency when compressed, it can be used as a modifier for resins and paints, a design imparting agent, etc.

Claims (7)

A cellulose complex powder comprising a cellulose-based material and a powder compound,
the cellulose-based material contains cellulose, and the content of the cellulose in the cellulose-based material is 50 to 100% by weight;
the powder compound has an alkyl group having 2 to 30 carbon atoms and/or two or more methyl groups, and a functional group, the functional group being at least one selected from a hydroxyl group, a primary to tertiary amino group, a carboxyl group, a carboxylate group, a phosphoric acid group, a phosphorylcholine group, a sulfonate group, and a silyl group;
The cellulose composite powder has an average particle size of 1 to 100 μm,
the circularity of the cellulose composite powder measured by an image analysis method is 0.4 to 1.0;
In a shear test based on JIS-Z8835, the shear adhesive strength C ₃₀ of the powder layer at a normal pressure of 30 MPa is more than 0 kPa and 5 kPa or less;
and the value ( _C30 / _C10 ) obtained by dividing the shear adhesive strength _C30 of the powder bed at a vertical pressure of 30 MPa by the shear adhesive strength _C10 of the powder bed at a vertical pressure of 10 MPa in the shear test is greater than 0 and equal to or less than 4;
The floating property of the cellulose composite powder in water satisfies the following condition 1:
Cellulose composite powder.
Condition 1: After shaking a 5% aqueous dispersion of the cellulose complex powder and leaving it to stand at 25°C for 12 hours, the proportion of the floating matter floating up to the interface between the water and the air is 50 to 100% by weight relative to 100% by weight of the cellulose complex powder contained in the 5% aqueous dispersion. The cellulose composite powder according to claim 1 has an oil absorption of 20 to 200 ml/100 g. The cellulose complex powder according to claim 1 or 2, wherein the powder compound is at least one selected from hydrophobic silica, fatty acids, fatty acid metal salts, amino acid substances, and complex lipids. The cellulose composite powder according to any one of claims 1 to 3, wherein the weight ratio of the powder compound to the cellulose composite powder is 0.1 to 20% by weight. The cellulose composite powder according to any one of claims 1 to 4, in which the powder compound is adhered to the surface of the cellulose-based material. A method for producing the cellulose composite powder according to any one of claims 1 to 5,
The method includes a step of dry-blending a powder containing a cellulose-based material and a powder compound, and a step of mechanochemically treating the powder,
the cellulose-based material contains cellulose, and the content of the cellulose in the cellulose-based material is 50 to 100% by weight;
The method for producing a cellulose composite powder, wherein the powder compound has an alkyl group having 2 to 30 carbon atoms and/or two or more methyl groups, and a functional group, the functional group being at least one selected from a hydroxyl group, a primary to tertiary amino group, a carboxyl group, a carboxylate group, a phosphate group, a phosphorylcholine group, a sulfonate group, and a silyl group. The method for producing a cellulose composite powder according to claim 6, further comprising a step of mechanically pulverizing the powder compound.