JP2005336119A - Method for producing oily particles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for more simply producing oily particles in a spherical form and can be used themselves as a cosmetic or the like. <P>SOLUTION: A liquid oil component that is kept at a temperature higher than the melting point thereof is added to an aqueous solvent that is kept at a temperature of 55 to 75°C under stirring. At this time, the specific gravity of the oil component to the aqueous solvent is adjusted to 0.90 to 2.3, the aqueous solvent is cooled down to a temperature lower than the melting point of the oil component under stirring to form the oil particles in the aqueous solvent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing oily particles that can be used as an external preparation such as cosmetics.

Regarding granular skin preparations, a method in which fats and oils are dissolved by heating and the fats and oils set at a temperature lower by 40 to 80 ° C. are dropped into a hard-to-dissolve solvent and solidified (JP-A-3-146595: Patent Document 1). ) Has been reported. In addition, several techniques for oil-based particles obtained by solidifying oils and fats in a granular or capsule form have been disclosed (Japanese Patent Laid-Open No. 7-258071: Patent Document 2, Japanese Patent Laid-Open No. 2003-73230: Patent Document 3). .
Japanese Patent Laid-Open No. 3-146595 Japanese Patent Laid-Open No. 7-258071 JP 2003-73230 A

  In the technique for producing oily particles described in Patent Document 1, in order to form spherical particles so that the particles do not become bowl-like or flat, the diameter, dropping distance or surface tension of the nozzle for dropping oil and fat is strictly limited. Therefore, a simpler method for producing spherical particles has been desired.

  The present inventor has made studies in order to solve the above-mentioned problems, and by simply setting the specific gravity of the oil component, which is a material for forming oily particles in the aqueous solvent, to a certain range, the oil content can be easily obtained. It has been found that it is possible to produce the desired oily particles, and the present invention has been completed.

That is, the present invention adds an oil component which is kept in a liquid state at a temperature equal to or higher than the melting point to an aqueous solvent which is stirred at a temperature of 55 to 75 ° C. The specific gravity of the oil is 0.90 to 2.3;
Next, the aqueous solvent is cooled to a temperature below the melting point of the oil while maintaining the stirring state, and the oily particles of the oil are granulated in the aqueous solvent (hereinafter referred to as the present production). (It is also referred to as a method).

  The specific gravity in the present invention is a specific gravity at 25 ° C. unless otherwise specified.

Oil and aqueous solvent The oil that becomes the material of the oil-based particles produced by this production method (hereinafter, unless otherwise specified, “oil” is used in this sense) is an oil that has at least a melting point higher than room temperature. It is necessary for the oily particles not to melt at the temperature in their normal use environment. “Room temperature” is a temperature at which a person normally lives and is not strictly specified, but a general concept thereof is about 15 to 30 ° C. Considering the summer temperature, it is preferable that the melting point of “oil” is 30 ° C. or higher. Since the oily particles produced by this production method need not be melted at such room temperature, all or part of the “oil” needs to be a solid oil. Specifically, the solid oil to be used as the material for the oily particles produced by this production method is preferably a solid oil having a melting point of 55 ° C. or higher, and particularly preferably 60 ° C. or higher. . When the melting point is less than 55 ° C., the particle surface tends to soften at room temperature, and the particles are not preferable in practical use. Further, the upper limit of the melting point of the solid oil component is less than 100 ° C., which is the boiling point of water, but practically less than 70 ° C. is preferable. Examples of solid oils satisfying the above melting point include hydrogenated jojoba oil (melting point 68 ° C.), eicosane diglyceryl behenate (melting point 66 ° C.), behenyl alcohol (melting point 68 ° C.), stearyl alcohol (melting point 58 ° C.). In particular, behenyl alcohol is preferred.

  As described above, the “oil” is required to be all or part of a solid oil, but when all of the “oil” is a solid oil, the resulting oily particles become hard and oily produced by this production method. It is not suitable for use as a “cosmetic for smearing on the skin”, which is a typical product form of particles. Therefore, it is often preferable that a part of the “oil” is a liquid oil. As the liquid oil, a liquid oil used in an external composition such as cosmetics can be used. Specifically, chain polysiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, trimethylpentaphenyltrisiloxane, decamethylpolysiloxane, dodecamethylpolysiloxane, tetramethyltetrahydrogenpolysiloxane, etc. Liquid silicone oils such as cyclic polysiloxanes, Avocado oil, Camellia oil, Turtle oil, Macadamia nut oil, Corn oil, Mink oil, Olive oil, Rapeseed oil, Egg yolk oil, Sesame oil, Persic oil, Wheat germ oil, Southern oil , Castor oil, linseed oil, safflower oil, cottonseed oil, eno oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, cinnagar oil, Japanese kiri oil, jojoba oil, germ oil, triglycerin, trioctanoic acid Glycerin, triisopal It can be mentioned liquid oil glycerin Chin acid. Among these, liquid silicone oil is preferable, and methylphenylpolysiloxane is particularly preferable. That is, methylphenylpolysiloxane has moderate compatibility with other oils, has low solubility of higher alcohols used as solid oils such as behenyl alcohol, and can produce stable oily particles. Is relatively heavy and can easily satisfy the conditions of the present invention.

  The weight ratio of the solid oil to the liquid oil in the “oil” can be appropriately selected within the range of specific gravity permitted in the “oil” depending on the specific product form and purpose of the oily particles to be produced. Usually, it is preferable that solid oil component: liquid oil component is about 1: 1 to 1:10 (mass ratio).

  As described above, an aqueous solvent for “oil” (water or water-soluble, such as sodium chloride, potassium chloride, sodium N-stearoyl-L-glutamate, ethyl alcohol, isopropyl alcohol, etc., if necessary for adjusting specific gravity, etc.) The specific gravity relative to the component in which the components are dissolved is 0.90 to 2.3, preferably 0.95 to 2.0. When the specific gravity of the “oil” is less than 0.90, the “oil” floats on the surface of the aqueous solvent and accumulates in the vicinity of the propeller shaft, making it difficult to form spherical particles. In addition, when the specific gravity is larger than 2.3, it sinks near the bottom of the aqueous solvent, and the oily particles tend to be flat particles. When the stirring speed is increased to prevent sedimentation, the particle size is 0.5 mm or less. It becomes fine particles. By setting the specific gravity of the “oil” within the above range, the floating state of the “oil” in the stirred aqueous solvent becomes moderate, and the oily particles that are nearly spherical have a uniform particle size, the stirring speed, and the “oil” It can be easily produced by adjusting the temperature of the aqueous solvent at the time of introduction.

  In particular, when the specific gravity of the “oil” is 1.0 or more, a powder having a high specific gravity, for example, a titanium oxide powder, a zinc oxide powder, an iron oxide powder, a barium sulfate powder, or the like is included in the “oil”. Thus, it is possible to easily achieve a desired specific gravity, and the functions of these powders such as ultraviolet ray protection ability can be exhibited on the skin. In order to stably disperse these powders in the “oil”, it is preferable to use them as powders subjected to appropriate surface treatment, for example, hydrophobic treatment.

  In addition, the oil component contains oil-soluble medicinal ingredients such as oil-soluble vitamins such as retinol palmitate, retinol acetate, tocopherol acetate, ascorbyl tetra-2-hexyldecanoate, etc. These active ingredients can be encapsulated to exert whitening, dullness prevention, rough skin prevention, moisturizing action and the like. Oily particles can be applied without waste as a dermatological agent in places where skin troubles such as rough skin, dullness and spots are observed. In addition, since it contains almost no water, it is possible to stabilize drugs such as vitamins that are unstable in the presence of water.

Manufacturing process The manufacturing method is preferably carried out as follows. First, the “oil” is adjusted to a temperature exceeding its melting point (usually a temperature exceeding the melting point of the solid oil) to form a liquid, which is 55 to 75 ° C. (60 to 70 ° C. is particularly suitable). After being introduced into the conditioned aqueous solvent under stirring, the mixture of this aqueous solvent and “oil” is further cooled under stirring (this cooling is preferably cooled to room temperature) and into the aqueous solvent. This can be done by forming oily particles. The particle size of the oil-based particles formed in the aqueous solvent is preferably about 0.5 to 4 mm, and particularly preferably about 1 to 3 mm.

  As described above, the main determinants of the size of the oily particles are the stirring speed of the aqueous solvent and the temperature of the aqueous solvent when the “oil” is introduced. The stirring speed of the aqueous solvent is relatively low, specifically 10 to 1500 rpm, preferably 20 to 300 rpm, and can be carried out using a propeller, paddle mixer or the like. The particle diameter of the oily particles decreases as the rotational speed increases, and the particle diameter of the oily particles tends to increase as the rotational speed decreases. Further, as described above, the temperature of the aqueous solvent at the time of adding the “oil” is preferably 55 to 75 ° C., particularly preferably about 60 to 70 ° C. That is, when an “oil” is added to an aqueous solvent having a temperature lower than 55 ° C., the oil is solidified before becoming spherical particles, so that large distorted particles tend to be generated. In addition, when the temperature of the aqueous solvent is higher than 75 ° C., the viscosity of the “oil” decreases, and the particles are finely cut by the force of stirring, so that the particles tend to be smaller than the target particles. .

  The introduction of the “oil” into the aqueous solvent can be performed, for example, by injecting directly from the liquid feeding means such as a liquid feeding pump through the nozzle or the like, or directly into the aqueous solvent. it can. The diameter of the nozzle outlet in this case also affects the oily particle diameter. That is, if the stirring speed and temperature of the aqueous solvent are the same, smaller particles tend to be formed when the diameter of the discharge port of the nozzle is smaller, and larger particles are formed when the nozzle is larger. The nozzle diameter is generally selected in the range of about 3 to 30 mm.

  Next, the mixture of the aqueous solvent and the “oil” is cooled to room temperature with stirring, so that the solid oil in the “oil” having a temperature not higher than the melting point is precipitated on the particle surface. . Thereby, oily particles can be formed in an aqueous solvent.

  In general, after producing oily particles in an aqueous solvent, the particles are separated from the aqueous solvent and dried. The separation / drying means is not particularly limited. For example, a method of filtering oily particles dispersed in an aqueous solvent through a mesh smaller than the oily particle diameter and drying it can be mentioned. The dried oily particles can be used as a granular skin preparation as it is, but in order to prevent welding of the particles, fine powder particles are attached to the oily particle surfaces, or dispersed in an aqueous gel, It can also be used as a skin preparation. In addition, by using a powder of a water-soluble medicinal ingredient as the fine powder particles, the function of the water-soluble medicinal ingredient (whitening action, dullness preventing action, rough skin preventing action, moisturizing action, etc.) is added to the oily particles. You can also

  According to the present invention, a simple method for producing oily particles useful as a cosmetic is provided.

  Examples of the present invention will be described here, but the present invention is not limited thereto. Moreover, unless otherwise indicated, the compounding quantity in description of an Example is the mass% with respect to the whole compounding object.

[Examples 1-7]
Test articles (Comparative Example 1 and Examples 1 to 7) were prepared according to the formulation described in Table 1 and the following production method, and the specific gravity of “oil” was examined.

<Manufacturing method>
The aqueous solvent in which the surface components 1 and 2 are dissolved and stirred is brought to a temperature of 65 ° C., placed in a cylindrical water tank, and this is stirred at 100 rpm, through a nozzle having a discharge port diameter of 10 mm. The oil phase obtained by stirring and mixing 11 at 80 ° C. was directly poured into an aqueous solvent. Thereafter, the water bath was cooled to 25 ° C. to produce oily particles, and then the oily particles were taken out of the aqueous solvent, washed with water, and dried to obtain a granular skin preparation.

  In the table, the specific gravity of the oil phase component was measured using a solid density / specific gravity measurement kit manufactured by METTLER TOLEDO.

  In addition, in the evaluation of the shape of the oil-based particles, a case where there is almost no distorted particle was evaluated as ◯, a case where there was a little distorted particle, and a case where there was a lot of distorted particle.

From this result, it was found that the specific gravity of the “oil” with respect to the aqueous solvent is preferably 0.90 to 2.3, and particularly preferably 0.95 to 2.0.
[Examples 8 to 11]
About the influence which the temperature of the aqueous solvent at the time of "oil" addition has on oily particles by preparing test products (Comparative Examples 2-3 and Examples 8-11) according to the formulation described in Table 2 and the following production method Was examined.

<Manufacturing method>
The aqueous solvent in which the surface components 1 and 2 are dissolved and stirred is brought to a temperature of 65 ° C., placed in a cylindrical water tank, and this is stirred at 100 rpm, through a nozzle having a discharge port diameter of 10 mm. The oil phase obtained by stirring and mixing 8 at 80 ° C. was directly poured into an aqueous solvent. Thereafter, the water bath was cooled to 25 ° C. to produce oily particles, and then the oily particles were taken out of the aqueous solvent, washed with water, and dried to obtain a granular skin preparation.

  In the table, the evaluation of the shape of the oil-based particles was evaluated as “◯” when there were almost no distorted particles, “Δ” when there were many distorted particles, and “X” when there were many distorted particles. The particle size was measured by randomly collecting 20 oily particles, taking an image of the oily particles together with a scale with a digital camera, and measuring the particle diameter (diameter) of each oily particle according to the scale.

  From these results, it became clear that the temperature of the aqueous solvent at the time of adding “oil” is preferably 55 to 75 ° C., and particularly preferably 60 to 70 ° C.

Claims (8)

An oil component that is liquid at a temperature equal to or higher than the melting point is added to an aqueous solvent that is stirred at a temperature of 55 to 75 ° C., and the specific gravity of the oil with respect to the aqueous solvent is 0.00. 90-2.3;
Subsequently, the aqueous solvent is cooled to a temperature lower than the melting point of the oil while maintaining the stirring state, and the oily particles of the oil are granulated in the aqueous solvent. The method for producing oil-based particles according to claim 1, wherein the oil component is an oil component containing a solid oil component having a melting point of 55 ° C or higher. The method for producing oily particles according to claim 1 or 2, wherein the oil component is a mixed oil component of a solid oil component having a melting point of 55 ° C or higher and an oil component that is liquid at normal temperature. The method for producing oily particles according to claim 2 or 3, wherein the solid oil is at least one solid oil selected from the group consisting of hydrogenated jojoba oil, eicosane diglyceryl behenate, behenyl alcohol, and stearyl alcohol. The method for producing oil-based particles according to claim 3 or 4, wherein the oil that is liquid at normal temperature is an oil containing methylphenylpolysiloxane. The manufacturing method of the oil-based particle in any one of Claims 1-5 whose temperature of the aqueous solvent before cooling is 60-70 degreeC. The manufacturing method of the oil-based particle in any one of Claims 1-6 whose temperature of the aqueous solvent after cooling is room temperature. The manufacturing method of the oil-based particle in any one of Claims 1-7 whose particle size of an oil-based particle is 1-3 mm.