JP2007152252A - Aqueous dispersion of coating oil particles and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an aqueous dispersion containing coating oil particles capable of stably enfolding an oil constituent even under such a severe condition as about 50°C. <P>SOLUTION: The aqueous dispersion of coating oil particles having a pH of 6.0-8.0 composed of coated oil particles having an average particle size not greater than 5 μm which is constituted by attaching the hardly water-soluble fine particles of an inorganic calcium salt on the surface of the oil particles is obtained by preparing an oil particle dispersion so as to disperse the oil constituent into water, preparing an inorganic particle dispersion by dispersing a fine particle coagulated body of a hardly water-soluble inorganic calcium salt into water, thereafter pulverizing the fine particle coagulated body into a fine particle having an average particle size not greater than 1 μm and further adjusting the pH of the dispersion into a range of 6.0-8.0, and mixing the oil dispersion with the inorganic fine particle dispersion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a coating oil particle aqueous dispersion and a method for producing the same, and more specifically, a coating oil in which inorganic fine particles are adhered to the surface of oil particles, and coating oil particles stably containing oil are dispersed in water. The present invention relates to an aqueous particle dispersion and a method for producing the same.

  As is well known, many medicinal ingredients, cosmetic ingredients, bactericidal ingredients, insecticidal ingredients, perfume ingredients, etc. contain oil. However, many of the oils contained in the above components are easily affected by light, oxygen, heat, pressure, etc., and are not stable over time. In addition, many oils have bitter tastes and unique odors. Poor oil stability over time, bitterness, and a unique odor caused problems such as reducing the effect of the intended application during storage and reducing the commercial value.

  On the other hand, conventionally, it has been proposed to coat an oil component. Patent Document 1 discloses a mixed liquid obtained by dispersing an oil-soluble substance and a calcium component in an aqueous solution in the presence of a surfactant. A technique for obtaining an oil-soluble substance-containing powder by drying is disclosed.

JP 2005-263948 A

  In the method of Patent Document 1, an oil-soluble substance is emulsified using a homomixer, but with this level of shearing force, the atomization of the oil-soluble substance remains at a level of several tens of μm. The clearance between the stators is wide, and there is no force to grind calcium particles to less than 1 μm. Therefore, the particle diameter of the particles containing the oil-soluble substance is inevitably as large as several tens of μm. Furthermore, in the present technology, in addition, since it is pulverized, it becomes several tens of μm or more from the viewpoint that powdering does not occur as ease of handling as powder. Such large particles have a drawback that they cannot exhibit permeability to microscopic parts (eg, skin, pores, periodontal pockets, tooth pits and fissures in the living body) and retention due to entering the gaps. .

  In the technique disclosed in Patent Document 1, the oil component can be coated with a calcium component regardless of the presence or absence of a surfactant, and the oil component can be coated without a drying step. Not coated with ingredients. In addition, as described above, since the calcium component has a large particle size, there is a drawback that the oil component easily leaks.

  On the other hand, prior to the present invention, the present inventors have proposed coated oil particles in which oil particles are coated with particles of poorly water-soluble inorganic calcium salt and a method for producing the same (Japanese Patent Application No. 2005-187210 and Japanese Patent Application No. 2005-187210). (Japanese Patent Application No. 2005-325312).

  In these previous applications, a method of obtaining coated oil particles having an average particle size of 5 μm or less by attaching finely water-insoluble inorganic calcium salt particles having an average particle size of 1 μm or less to the surface of the oil particles was proposed.

  According to the previous application of the present inventors, fine coated oil particles having an average particle diameter of 5 μm or less formed by coating oil particles with fine particles of poorly water-soluble inorganic calcium salt can be formed without using a fixing agent or the like. it can. However, if the coated oil particles are to be used in actual application sites, it must also be considered that the coated oil particles are used under more severe conditions. It is desirable that the coated oil particles have high stability even under more severe conditions. The severe conditions are assumed to be used at a high temperature of room temperature or higher, for example. In the case of using an oil component containing a phenolic compound as the oil particles, the fact that the oil component does not elute even under more severe conditions of about 50 ° C. leads to a further improvement in performance. Such further performance improvement has not been studied in the earlier application of the present inventors.

  The present invention is intended to solve the above-described problems, and contains coated oil particles that can stably contain oil even under a temperature higher than room temperature, for example, a severer temperature condition of about 50 ° C. It is an object to provide an aqueous dispersion.

The inventors of the present invention have intensively studied to solve the above problems, and confirm the following actions and effects by adjusting the pH of the aqueous dispersion in which the coating oil particles are dispersed to 6-8. It came to.
(1) Aggregation between inorganic calcium salt fine particles is increased, and oil can be stably coated even without a fixing agent.
(2) A stable film can be formed even if the coating thickness of the inorganic calcium salt fine particles is thin.
(3) Oil particles containing an oil component containing a phenolic compound can be stably encapsulated.
(4) The coated oil particles in the obtained aqueous dispersion have good stability under more severe conditions of about 50 ° C.
The present invention has been made based on such knowledge.

  That is, the coated oil particle aqueous dispersion of the present invention is a coated oil particle aqueous dispersion in which coated oil particles in which fine particles of poorly water-soluble inorganic calcium salt are adhered to the surface of oil particles are dispersed in water, The poorly water-soluble inorganic calcium salt fine particles have an average particle size of 1 μm or less, the coated oil particles have an average particle size of 5 μm or less, and a pH of 6.0 to 8.0.

  Also, the method for producing a coated oil particle aqueous dispersion according to the present invention comprises an emulsification step in which an oil component is dispersed in moisture to obtain an oil particle dispersion, and a water-soluble inorganic calcium salt fine particle aggregate is dispersed in water. Thereafter, the fine particle aggregate is pulverized into fine particles having an average particle diameter of 1 μm or less, and the pH of the dispersion is adjusted to a range of 6.0 to 8.0 to obtain an inorganic fine particle water dispersion. By mixing the dispersion liquid preparation step and the oil particle dispersion liquid and the inorganic fine particle aqueous dispersion liquid, coated oil particles in which fine particles of poorly water-soluble inorganic calcium salt are adhered to the surface of the oil particles are dispersed in water. And a coated oil particle aqueous dispersion preparation step for obtaining a coated oil particle aqueous dispersion having a pH of 6.0 to 8.0.

According to the present invention, the following effects can be obtained.
(1) The oil containing a phenolic compound is stably encapsulated without being eluted from the coated oil particles, and the stability over time under more severe conditions of about 50 ° C. is also good.
(2) The oil component can be contained stably, and the influence of the oil component from light, oxygen, heat, pressure, etc. can be weakened.
(3) A large amount of oil (medicinal components, etc.) can be included.
(4) It is hard to break because it is coated with water-insoluble calcium-containing inorganic fine particles, and is stable even if the coating thickness is thin.
(5) It can mask the taste and smell of oil.
(6) Since the coating is formed by agglomerating on the surface of the oil particles, the membrane has micropores, and the oil contained therein can be gradually released.
(7) Since fine particles of poorly water-soluble inorganic calcium salt are used, safety is high even when used in a living body.
(8) The coating thickness of the coated oil particles of the present invention can be controlled by appropriately adjusting the amount of oil and the amount of fine particles of poorly water-soluble inorganic calcium salt.
(9) By controlling the particle size of the oil particles, it is possible to control the average particle size of the coated oil particles to, for example, 5 μm or less.

Hereinafter, embodiments of the present invention will be described.
The oil particles in the present invention are composed of one or more oil components. The oil is not particularly limited as long as it is an oil that does not react with the poorly water-soluble inorganic calcium salt or the surfactant described later.

  Examples of such oils include hydrocarbons such as n-hexane, n-octane, cyclohexane, liquid paraffin, benzene, toluene, xylene, cumene and styrene, halogenated hydrocarbons such as trichloroethane and trichloroethylene, and Esters such as methyl palmitate, methyl stearate, methyl oleate, isopropyl myristate, isopropyl palmitate, and higher alcohols such as lauryl alcohol, stearyl alcohol, oleyl alcohol, salad oil, olive oil, sesame oil, castor oil Natural and synthetic oils such as soybean oil, rapeseed oil, linseed oil, corn oil, palm oil, whale wax, cholesterol, silicone oil, mineral oil, lard, beeswax, cottonseed oil, lanolin and petrolatum, , High molecular weight polymers such as polystyrene and polyethylene, fragrances such as menthol, limonene, terpinene, geraniol, muscone, lemon fragrance, cosmetic ingredients such as squalane, ceramide, collagen, panthenol, pantothenic acid, medicinal and effective Ingredients, other agricultural chemicals, insecticidal ingredients, antibacterial, antifungal ingredients and the like.

  In addition, these components that are not soluble in the oil, or other components that are not the oil itself, and that do not react with the poorly water-soluble inorganic calcium salt or the surfactant described later, whether the component is soluble or insoluble in the oil. If so, it can be included by dissolving or dispersing in the oil. Examples of substances that can be used in this way include amino acids, and high-molecular substances such as proteins, enzymes, DNA, and sugars.

  The phenolic compound is a compound having a phenol structure in the molecule. For example, triclosan, isopropylmethylphenol (IPMP), thymol, o-cresol, m-cresol, p-cresol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-nitrophenol, m-nitrophenol, Examples thereof include p-nitrophenol, phenol, phenoxyethanol, hinokitiol, salicylic acid, methyl salicylate, salicylaldehyde, tyrosine, 2-methoxyphenol, 3-methoxyphenol, 4-methoxyphenol, and thiophenol. These may be used alone as an oil, or may be used by dissolving them in the above oil. It is the oil which mentioned above n-hexane, n-octane, etc. as an example.

  The poorly water-soluble inorganic calcium salt used in the present invention is not particularly limited as long as it is a poorly water-soluble inorganic calcium salt that does not react with the oil used in the present invention. For example, calcium carbonate, calcium phosphate, calcium sulfate, calcium fluoride, calcium silicate, dicalcium phosphate, hydroxyapatite, fluoride apatite and the like can be mentioned.

  Since the average particle size of the fine water-insoluble inorganic calcium salt particles is 1 μm or less, high surface activity can be imparted. Therefore, the present invention finally obtained by appropriately controlling the particle size of the oil particles It is possible to easily control the particle size of the coated oil particles.

  The coating oil particle aqueous dispersion of the present invention has a pH set in the range of 6.0 to 8.0. If the pH is less than 6.0, the poorly water-soluble inorganic calcium salt is dissolved, and there is a risk that the oil will leak from the coated oil particles. On the other hand, if the pH exceeds 8.0, the phenolic compound in the oil may be eluted from the coated oil particles. By controlling the pH of the aqueous dispersion in the range of 6.0 to 8.0, even oil components containing phenolic compounds can be included more stably. Moreover, oil can be stably encapsulated even under more severe conditions of about 50 ° C.

  In the present invention, when the pH is out of the range of 6.0 to 8.0 in the manufacturing process of the coating oil particle aqueous dispersion described later, the pH is adjusted to the range of 6.0 to 8.0. I need. At this time, it adjusts so that pH may be in the range of 6.0-8.0 using an acid and an alkali.

  As the acid for adjusting the pH, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, lactic acid, citric acid and the like can be used. Of these, sulfuric acid, phosphoric acid, and citric acid are preferred.

  As an alkali for pH adjustment, sodium hydroxide, potassium hydroxide, etc. can be used.

  The coated oil particles in the coated oil particle aqueous dispersion of the present invention are formed by coating the oil particles by attaching fine particles of a poorly water-soluble inorganic calcium salt having an average particle size of 1 μm or less to the surface of the oil particles. The average particle diameter is controlled to a dimension of 5 μm or less. Here, FIG. 1 is a conceptual diagram of coated oil particles in which oil particles are coated with fine particles of a poorly water-soluble inorganic calcium salt. As shown in FIG. 1, the oil particles 2 a are coated with fine particles 1 a of a poorly water-soluble inorganic calcium salt to form coated oil particles 3.

  FIG. 2 illustrates a mechanism in which fine particles of a poorly water-soluble inorganic calcium salt adhere to oil particles. As shown in FIG. 2, the slightly water-soluble inorganic calcium salt fine particles 1a having a particle size of 1 μm or less have a large surface energy, so that they are attracted and adhered to the surface of the oil particles, and the oil particles 2a can be stably attached without using a sticking agent. Cover. Furthermore, a stable coating can be formed even if the coating thickness is thin. Therefore, the weight ratio of the oil to the poorly water-soluble inorganic calcium salt can be increased. Moreover, since this coating film has pores, it is excellent in the sustained release property of the coated oil. Furthermore, when it is desired to release the oil, it is possible to dissolve the coating layer made of a poorly water-soluble inorganic calcium salt by dissolving it with an acid or an alkali. For example, in the case of calcium carbonate, if an acid is allowed to act, the coating layer dissolves, so that oil can be released freely.

  The average particle diameter of the coated oil particles of the present invention is 5 μm or less. This particle size can be controlled by controlling the particle size of the oil particles themselves and adjusting the coating thickness of the poorly water-soluble inorganic calcium salt fine particles.

  The average coating thickness represents the average value of the coating thickness of the slightly water-soluble inorganic calcium salt fine particles constituting the coated oil particles of the present invention. It can be controlled by appropriately adjusting the weight ratio between the finely particulate water-insoluble inorganic calcium salt adhering to the surface and the oil particles.

Next, the manufacturing method of the coating oil particle aqueous dispersion of this invention is demonstrated using figures.
(I) The emulsification process which disperses | distributes oil in a water | moisture content and obtains an oil particle dispersion liquid The oil particle which consists of the said oil component may make the said oil component into an oil particle by what kind of method. As a specific example of the method for obtaining oil particles, emulsification treatment may be mentioned. When oil particles are formed by emulsification, the particle size of the oil particles can be adjusted by adjusting the stirring time, stirring speed, temperature, etc. using a homogenizer, a pulverizer, an emulsifier or the like.

  First, the oil 2 to be coated is mixed with water 4 and stirred with an emulsifying device or the like, and the oil particles 2a are dispersed in moisture to obtain an oil particle dispersion, that is, an emulsion (O / W emulsion) 5 ( Emulsification step). At this time, when an oily substance that is solid is included in the oil, it is preferable to prepare the emulsion (O / W emulsion) 5 at a temperature higher than the melting point (emulsification step). Examples of emulsifiers include high-speed shearing emulsifiers such as homogenizers, homomixers, disper mixers, ultramixers, homomic line mills, milders, and CLEARMIX, high-pressure emulsifiers such as microfluidizers, gorin, optimizers, and nanomizers, Examples thereof include an ultrasonic emulsifier such as an ultrasonic disperser and an ultrasonic homogenizer. In general, when there is no surfactant, it is difficult to obtain an emulsion (O / W emulsion) 5 with only oil 2 and water 4, but by using the above-mentioned emulsifying apparatus etc., the emulsion is obtained in the apparatus. (O / W emulsion) 5 can be obtained. In this case, in order to make it easier to coat the oil particles 2a with fine particles whose pH is adjusted with a poorly water-soluble inorganic calcium salt, a surfactant is further added to the oil 2 and water 4 and mixed, stirred, and an emulsion (O / W emulsion) 5 is desirable.

(Ii) Step of preparing an inorganic fine particle aqueous dispersion The hardly water-soluble inorganic calcium salt is atomized to an average particle diameter of 1 μm or less as long as it can be atomized to an average particle diameter of 1 μm or less. For example, it can be prepared by pulverization using a conventional atomizer. Specific examples of such atomizers include bead mills, ball mills, various medialess mills, ultrasonic dispersers, and the like. As the atomization apparatus that can be used in the present invention, for example, Ultra Apex Mill (manufactured by Kotobuki Industries Co., Ltd.), Star Mill (Ashizawa Finetech Co., Ltd.), Philmix (manufactured by Primics Co., Ltd.), Discoplex (Manufactured by Hosokawa Alpine Co., Ltd.), ACM-A Pulverizer (manufactured by Hosokawa Micron Corporation), Nanocut (manufactured by Matsubo Co., Ltd.), CLEAR SS-5, Claremix (manufactured by M Technique Co., Ltd.), ultrasonic disperser UH -600SR (manufactured by SMT Co., Ltd.), ultrasonic homogenizer (manufactured by Dr. Hielscher) and the like.

  The pH of the aqueous dispersion of the water-insoluble inorganic calcium salt fine particles finely atomized to an average particle diameter of 1 μm or less thus obtained is adjusted to the range of 6.0 to 8.0. This is done by adding acid or alkali. At this time, it is preferable that acid or alkali is added to the apparatus in which the inorganic fine particle aqueous dispersion is prepared, and the pH is adjusted with the same apparatus. By mixing with the same apparatus, the water-insoluble inorganic calcium salt can be atomized and the pH can be adjusted simultaneously, and the process can be simplified.

  After the slightly water-soluble inorganic calcium salt fine particle aggregate 1 is dispersed in water 4, the fine water aggregate of the poorly water-soluble inorganic calcium salt 1 is pulverized by the above-mentioned pulverizer and the average particle diameter of the slightly water-soluble inorganic calcium salt having an average particle size of 1 μm or less. 1a to obtain an inorganic fine particle aqueous dispersion 6 (inorganic fine particle aqueous dispersion preparation step). However, the present invention is not limited thereto, and it may be prepared by preparing a slightly water-insoluble inorganic calcium salt with an average particle diameter of 1 μm or less to form fine particles 1a of a poorly water-soluble inorganic calcium salt and then dispersing in water 4.

  Next, the pH of the inorganic fine particle aqueous dispersion 6 is adjusted to 6.0 to 8.0. After the step of atomizing the poorly water-soluble inorganic calcium salt, acid or alkali is added to the atomizer as it is until the pH falls within the range of 6.0 to 8.0.

(Iii) Coating oil particle aqueous dispersion preparation step in which coating oil particles are dispersed In this step, the oil particles are mixed with the inorganic fine particle aqueous dispersion to thereby make the oil particles less water-soluble inorganic calcium salt. Coated oil particles coated with the above fine particles are obtained in an aqueous dispersion.

  By mixing the emulsion (O / W emulsion) 5 obtained in the emulsification step and the inorganic fine particle aqueous dispersion 6 obtained by adjusting the pH of the inorganic fine particle aqueous dispersion, the oil particles 2a in the emulsion are mixed. The coated oil particles 3 are obtained in an aqueous dispersion by coating with fine particles 1a of a poorly water-soluble inorganic calcium salt (mixed coating step). This mixing can be performed by using a mixing apparatus capable of uniformly stirring the emulsion 5 and the inorganic fine particle aqueous dispersion 6 obtained by adjusting the pH of the inorganic fine particle aqueous dispersion.

  Examples of the mixing apparatus that can be used in the present invention include stirring apparatuses such as a paddle mixer and a propeller mixer in addition to the above-described emulsification apparatus and atomization apparatus, and can be performed by stirring with a stirrer chip. Alternatively, the emulsion 5 may be added to the dispersion of the inorganic fine particle aqueous dispersion whose pH is adjusted using the same apparatus as that for preparing the dispersion of the inorganic fine particle aqueous dispersion whose pH is adjusted. At this time, it is preferable to add the emulsion 5 to the apparatus in which the pH-adjusted dispersion of the inorganic fine particle aqueous dispersion is prepared, and perform mixing in the same apparatus. By mixing with the same apparatus, the oil particles 2a and the slightly water-soluble inorganic calcium salt fine particles 1a can be atomized, and the emulsion 5 and the inorganic fine particle aqueous dispersion 6 can be mixed simultaneously, thereby simplifying the process. It becomes.

  In addition, by mixing the emulsion 5 and the pH-adjusted dispersion of the inorganic fine particle aqueous dispersion 6, an aqueous dispersion 7 of the coated oil particles is obtained, in which a large number of the coated oil particles 3 are dispersed. Will be. In this case, the aqueous dispersion 7 of the coated oil particles 3 is the coated oil particle aqueous dispersion of the present invention.

  In order to confirm that the coated oil particles are properly prepared, a simple method of sandwiching the obtained coated oil particles with a glass plate and applying pressure is possible. According to this method, since the particles are crushed and the oil component comes out, it can be confirmed that the oil particles are encapsulated by the coating layer.

  More precisely, it can also be confirmed by slicing the coated oil particles of the present invention and observing the cross section with a transmission electron microscope (TEM).

  In addition, when a poorly water-soluble inorganic calcium salt that dissolves in acid or alkali is used as the poorly water-soluble inorganic calcium salt, if the poorly water-soluble inorganic calcium salt is dissolved in acid or alkali, the oil will emerge. It can also be confirmed by observing it.

  The feature of the aqueous dispersion of coated oil particles of the present invention is that its pH is adjusted within the range of 6.0 to 8.0. This pH value can be obtained by a simple method of measuring the coating oil particle aqueous dispersion obtained as described above with a pH meter (for example, PH82 type, manufactured by Yokogawa Electric Corporation). it can.

  The average particle size of the oil particles prepared in the emulsification step is preferably 10 nm to 5 μm, more preferably 50 nm to 1 μm. If the average particle size of the oil particles is less than 10 nm, the amount of oil contained in the coated oil particles is undesirably reduced to an amount outside the practical range. On the other hand, if the average particle diameter of the oil particles exceeds 5 μm, the stability of the coated oil particles decreases, which is not preferable.

  In the present invention, the average particle size of the poorly water-soluble inorganic calcium salt fine particles forming the coating layer of oil particles is preferably 1 nm to 1 μm, more preferably 5 nm to 500 nm when the oil component contains a surfactant. Particularly preferably, the thickness is 10 nm to 200 nm. When the oil does not contain a surfactant, the average particle diameter of the poorly water-soluble inorganic calcium salt fine particles is preferably 1 nm to 100 nm, more preferably 5 nm to 80 nm, and particularly preferably 10 nm to 50 nm. is there. When the average particle diameter of the slightly water-soluble inorganic calcium salt fine particles is less than the lower limit, the amount of the slightly water-soluble inorganic calcium salt fine particles dissolved is increased, which is not preferable. On the contrary, if the upper limit is exceeded, the coating efficiency of the oil particles is lowered, and the stability of the coated oil particles is lowered.

  The pH of the coated oil particle aqueous dispersion of the present invention is preferably 6.0 to 8.0, and more preferably 6.5 to 7.5. When the pH of the coating oil particle aqueous dispersion is less than 6.0, the fine particles of the poorly water-soluble inorganic calcium salt are easily dissolved, and the stability of the coating oil particles is lowered. Conversely, when the pH of the slightly water-soluble inorganic calcium salt fine particles exceeds 8.0, the phenolic compound in the oil is easily eluted from the coated oil particles, and the stability of the coated oil particles decreases.

  The average particle diameter of the coated oil particles in the coated oil particle aqueous dispersion of the present invention is preferably 10 nm to 5 μm, more preferably 50 nm to 1 μm. If the average particle diameter of the coating oil particles is less than 10 nm, the coating oil particles are likely to leak because the coating thickness of the coating oil particles is too small. On the other hand, when the average particle diameter of the coated oil particles exceeds 5 μm, the coated oil particles are easily broken by external pressure, and further, the permeability to a minute part such as a living body and the retention in the administration part are lowered.

  The average coating thickness of the coating oil particles (the thickness of the coating layer made of the poorly water-soluble inorganic calcium salt fine particles) is not particularly limited as long as it is a thickness capable of retaining the encapsulated oil content, but is preferably 10 nm to 2 μm, and more preferably 20 nm. ˜1 μm, particularly preferably 50 nm to 500 nm. When the average coating thickness is less than 10 nm, the coated oil particles are easily broken, and when the average coating thickness exceeds 2 μm, the amount of oil contained inevitably decreases.

  The weight ratio of the slightly water-soluble inorganic calcium salt fine particles to the oil in the coated oil particles in the coated oil particle aqueous dispersion of the present invention is preferably 10/10 to 100/10, more preferably 30/10 to 90. / 10, and particularly preferably 50/10 to 80/10. When this weight ratio is less than 10/10, the coating thickness becomes small, and the coated oil particles are easily broken. On the other hand, if this weight ratio exceeds 100/10, some of the resulting coated oil particles may not contain the oil particles, which may result in lack of coating uniformity. There is also a risk that the coated oil particles aggregate to form coarse particles.

  The weight ratio of oil to water in the coated oil particle aqueous dispersion of the present invention is preferably 1/1000 to 7/10, more preferably 1/200 to 1/2, and particularly preferably 1/100. ~ 3/10. When this weight ratio is less than 1/1000, when the poorly water-soluble inorganic calcium salt fine particles are mixed with a pH-adjusted dispersion, the rate at which the coated oil particles are formed becomes slow, and the poorly water-soluble inorganic calcium salt fine particles are aggregated alone. As a result, the abundance of coated oil particles covering the oil component decreases. On the contrary, when the weight ratio exceeds 7/10, the viscosity is remarkably increased in the production process, and it becomes difficult to uniformly coat with inorganic fine particles when the water-insoluble inorganic calcium salt fine particles described later are mixed with a pH adjusted dispersion. Or coagulation solidification occurs.

  The mass% of the poorly water-soluble inorganic calcium salt fine particles in the aqueous dispersion of the poorly water-soluble inorganic calcium salt fine particles is preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, especially. Preferably it is 1-10 mass%. When the mass% of the hardly water-soluble inorganic calcium salt fine particles with respect to the total amount of the aqueous dispersion is less than 0.1 mass%, the concentration of the poorly water-soluble inorganic calcium salt fine particles is small, so that the coating efficiency of the oil particles decreases. On the other hand, if the mass% of the hardly water-soluble inorganic calcium salt fine particles with respect to the total amount of the aqueous dispersion exceeds 50 mass%, the viscosity of the inorganic fine particle aqueous dispersion may increase, and aggregation and solidification may occur. Leading to a decline.

  The coated oil particle aqueous dispersion of the present invention may contain a surfactant in order to disperse the oil. That is, the oil content of the coated oil particles in the coated oil particle aqueous dispersion of the present invention preferably contains a surfactant. In this case, the surfactant is preferably present on the surface of the oil particles. The surfactant to be used is preferably an anionic surfactant or a nonionic surfactant having high calcium particle dispersibility.

  By including a surfactant in the oil as described above, the adsorptivity and adhesion of finely water-insoluble inorganic calcium salt particles to the oil particle surface are increased, and more than in the case where no surfactant is contained. Coated oil particles that stably encapsulate the oil component can be obtained.

  Examples of the anionic surfactant include higher alcohol sulfates and alkane sulfonates. Specific examples of the higher alcohol sulfate include sodium lauryl sulfate, potassium lauryl sulfate, sodium myristyl sulfate, potassium myristyl sulfate, sodium palmityl sulfate, potassium palmityl sulfate, sodium stearyl sulfate, potassium stearyl sulfate, sodium oleyl sulfate, and oleyl. Such as potassium sulfate. Examples of alkane sulfonates include sodium dodecane sulfonate, potassium dodecane sulfonate, sodium tetradecane sulfonate, potassium tetradecane sulfonate, sodium hexadecane sulfonate, potassium hexadecane sulfonate, sodium octadecane sulfonate, potassium octadecane sulfonate, etc. Can do.

  As the nonionic surfactant having high calcium particle dispersibility, a nonionic surfactant having high calcium particle dispersibility described in Japanese Patent Application No. 2005-325312 can be used. Specifically, sucrose stearate (for example, Ryoto Sugar Ester S-1570, S-1670 manufactured by Mitsubishi Chemical Foods), sucrose palmitate (for example, Ryoto Sugar Ester P-1570 manufactured by Mitsubishi Chemical Foods, P-1670), sucrose myristic acid ester (for example, Ryoto Sugar Ester M-1695 manufactured by Mitsubishi Chemical Foods), sucrose oleic acid ester (for example, Ryoto Sugar Ester O-1570 manufactured by Mitsubishi Chemical Foods), sucrose laurin Acid ester (for example, Ryoto Sugar Ester L-1695 manufactured by Mitsubishi Chemical Foods), decaglyceryl monomyristate (for example, Decaglyn 1-M manufactured by Nikko Chemicals), decaglyceryl monostearate (for example, Decaglyn 1- manufactured by Nikko Chemicals) S), decaglyceryl monoisostearate (for example, Decaglyn 1-IS manufactured by Nikko Chemicals), polyoxyethylene (15) lauryl ether (for example, EMALEX 715 manufactured by Nihon Emulsion), and the like.

  As other surfactants, even a polymer compound can be used as long as it does not react with the poorly water-soluble inorganic calcium salt or the oil.

  The mass% of the surfactant based on the oil content is preferably 100% by mass or less, more preferably 1 to 70% by mass, and particularly preferably 5 to 50% by mass. The lower limit of the amount of the surfactant added to the oil is a value that excludes a range where the addition effect cannot be obtained, but a slight difference occurs depending on the physical properties of the oil particles themselves. When the mass% of the surfactant with respect to the oil content exceeds 100 mass%, the surfactant partially forms micelles, and there is a high possibility that the water-insoluble inorganic calcium salt fine particles are coated around the micelles. The abundance of the coated oil particles encapsulating is reduced.

  Hereinafter, the present invention will be described in more detail based on examples. The examples described below are merely examples for suitably explaining the present invention, and do not limit the present invention.

Example 1
In a 200 mL beaker, 1.4 g of sodium lauryl sulfate (manufactured by Junsei Chemical Co., Ltd.) as an anionic surfactant was dissolved in 67.2 g of pure water, and triclosan (Ciba Specialty), which is a phenolic compound, was used as an oil here.・ A mixture of 0.4 g of Chemicals Co., Ltd. dissolved in 1.0 g of soybean oil (trade name: Soybean Oil YM / Nisshin Oillio Group Co., Ltd.) was added, and a homogenizer (ULTRA manufactured by TKA-WERKE) was added. O / W emulsion was prepared by stirring (10000 rpm, 5 minutes) using TURRAX T25BASIC.

On the other hand, 7 g of calcium carbonate (Porecal-N manufactured by Shiraishi Calcium Co., Ltd.) was dispersed in 343 g of pure water. This was charged into a stock solution tank of a bead mill (Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)), supplied to the mill while being dispersed (flow rate 10 kg / hr), and ZrO ₂ φ0.1 mm beads were used. Then, pulverization was performed at 23 to 25 ° C. for 30 minutes (mill rotational speed: 4350 rpm). During this time, at 10 minutes of pulverization, 2.0 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank to adjust the pH to 7.0. Furthermore, 0.9 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank at the time of pulverization 25 minutes, and the pH was adjusted to 7.0.

  In the mill raw material tank where the obtained calcium carbonate fine particle dispersion is present, the above O / W emulsion is mixed and further pulverized in a bead mill for 30 minutes to coat the mixture of triclosan and soybean oil with calcium carbonate fine particles. An aqueous dispersion of coated oil particles was obtained. The pH of this aqueous dispersion was 7.5. Table 1 shows the physical properties of the coated oil particles in this aqueous dispersion.

(Example 2)
In a 200 mL beaker, 1.4 g of sodium lauryl sulfate (manufactured by Junsei Chemical Co., Ltd.) as an anionic surfactant was dissolved in 67.2 g of pure water, and triclosan (Ciba Specialty), which is a phenolic compound, was used as an oil here. -1.4g of Chemicals Co., Ltd. was dispersed and heated to 65 ° C, and then stirred with a stirrer (2 cm length) at 300 rpm for 30 minutes to prepare an O / W emulsion.

On the other hand, 7 g of calcium carbonate (Porecal-N manufactured by Shiraishi Calcium Co., Ltd.) was dispersed in 343 g of pure water. This was charged into a stock solution tank of a bead mill (Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)), supplied to the mill while being dispersed (flow rate 10 kg / hr), and ZrO ₂ φ0.1 mm beads were used. Then, pulverization was performed at 60 to 65 ° C. for 30 minutes (mill rotational speed: 4350 rpm). During this time, at 10 minutes of pulverization, 2.0 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank to adjust the pH to 7.0. Furthermore, 0.9 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank at the time of pulverization 25 minutes, and the pH was adjusted to 6.9.

  In the mill raw material tank in which the obtained calcium carbonate fine particle dispersion is present, the above O / W emulsion is mixed, and further pulverized in a bead mill for 30 minutes, and water of coated oil particles coated with triclosan with fine particles of calcium carbonate. A dispersion was obtained. The pH of this aqueous dispersion was 7.9. Table 1 shows the physical properties of the coated oil particles in this aqueous dispersion.

(Example 3)
In a 200 mL beaker, 1 g of sodium lauryl sulfate (manufactured by Junsei Chemical Co., Ltd.) as an anionic surfactant is dissolved in 48 g of pure water, and a phenolic compound, triclosan (Ciba Specialty Chemicals Co., Ltd.), is used as an oil here. 1) 1 g was dispersed and heated to 65 ° C., and then stirred with a stirrer (2 cm long) at 300 rpm for 30 minutes to prepare an O / W emulsion.

On the other hand, 7 g of calcium carbonate (Porecal-N manufactured by Shiraishi Calcium Co., Ltd.) was dispersed in 343 g of pure water. This was charged into a stock solution tank of a bead mill (Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)), supplied to the mill while being dispersed (flow rate 10 kg / hr), and ZrO ₂ φ0.1 mm beads were used. Then, pulverization was performed at 60 to 65 ° C. for 30 minutes (mill rotational speed: 4350 rpm). During this time, at 10 minutes of pulverization, 2.0 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank to adjust the pH to 7.0. Furthermore, 0.9 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank at the time of pulverization 25 minutes, and the pH was adjusted to 6.9.

  In the mill raw material tank in which the obtained calcium carbonate fine particle dispersion is present, the above O / W emulsion is mixed, and further pulverized in a bead mill for 30 minutes, and water of coated oil particles coated with triclosan with fine particles of calcium carbonate. A dispersion was obtained. The pH of this aqueous dispersion was 7.6. Table 1 shows the physical properties of the coated oil particles.

Example 4
In a 200 mL beaker, 1.4 g of sodium lauryl sulfate (manufactured by Junsei Chemical Co., Ltd.) as an anionic surfactant is dissolved in 67.2 g of pure water, and isopropylmethylphenol (IPMP), which is a phenolic compound, is used as an oil here. ) (Osaka Kasei Co., Ltd.) 0.4 g of soybean oil (trade name: Soybean Oil YM / Nisshin Oillio Group Co., Ltd.) 1.0 g was added and a homogenizer (manufactured by TKA-WERKE) was added. The mixture was stirred (10000 rpm, 5 minutes) using ULTRA-TURRAX T25BASIC to prepare an O / W emulsion.

On the other hand, 7 g of calcium carbonate (Porecal-N manufactured by Shiraishi Calcium Co., Ltd.) was dispersed in 343 g of pure water. This was charged into a stock solution tank of a bead mill (Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)), supplied to the mill while being dispersed (flow rate 10 kg / hr), and ZrO ₂ φ0.1 mm beads were used. Then, pulverization was performed at 23 to 25 ° C. for 30 minutes (mill rotational speed: 4350 rpm). During this time, at 10 minutes of pulverization, 2.0 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank to adjust the pH to 7.0. Furthermore, 0.9 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank at the time of pulverization 25 minutes, and the pH was adjusted to 6.8.

  In the mill raw material tank where the obtained calcium carbonate fine particle dispersion is present, the above O / W emulsion is mixed and further pulverized in a bead mill for 30 minutes to coat the mixture of IPMP and soybean oil with calcium carbonate fine particles. An aqueous dispersion of coated oil particles was obtained. The pH of this aqueous dispersion was 7.4. Table 1 shows the physical properties of the coated oil particles.

(Example 5)
In a 200 mL beaker, 1.4 g of sodium lauryl sulfate (manufactured by Junsei Chemical Co., Ltd.) as an anionic surfactant is dissolved in 67.2 g of pure water, and thymol (Tokyo Chemical Industry Co., Ltd.), which is a phenolic compound, is used as an oil here. Co., Ltd.) 0.4 g of soybean oil (trade name: soybean oil YM / Nisshin Oillio Group Co., Ltd.) 1.0 g was added to the mixture and a homogenizer (ULTRA-TURRAX T25BASIC manufactured by TKA-WERKE) was added. ) Was used (10000 rpm, 5 minutes) to prepare an O / W emulsion.

On the other hand, 7 g of calcium carbonate (Porecal-N manufactured by Shiraishi Calcium Co., Ltd.) was dispersed in 343 g of pure water. This was charged into a stock solution tank of a bead mill (Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)), supplied to the mill while being dispersed (flow rate 10 kg / hr), and ZrO ₂ φ0.1 mm beads were used. Then, pulverization was performed at 23 to 25 ° C. for 30 minutes (mill rotational speed: 4350 rpm). During this time, at 10 minutes of pulverization, 2.0 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank to adjust the pH to 7.0. Furthermore, 0.9 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank at the time of pulverization 25 minutes, and the pH was adjusted to 7.0.

  In the mill raw material tank where the obtained calcium carbonate fine particle dispersion is present, the above O / W emulsion is mixed and further pulverized in a bead mill for 30 minutes to coat the mixture of thymol and soybean oil with calcium carbonate fine particles. An aqueous dispersion of coated oil particles was obtained. The pH of this aqueous dispersion was 7.5. Table 1 shows the physical properties of the coated oil particles.

(Example 6)
In a 200 mL beaker, 1.4 g of sodium lauryl sulfate (manufactured by Junsei Chemical Co., Ltd.) as an anionic surfactant is dissolved in 67.2 g of pure water, and thymol (Tokyo Chemical Industry Co., Ltd.), which is a phenolic compound, is used as an oil here. 1.4 g was dispersed and heated to 65 ° C., and then stirred with a stirrer (2 cm length) at 300 rpm for 30 minutes to prepare an O / W emulsion.

On the other hand, 7 g of calcium carbonate (Porecal-N manufactured by Shiraishi Calcium Co., Ltd.) was dispersed in 343 g of pure water. This was charged into a stock solution tank of a bead mill (Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)), supplied to the mill while being dispersed (flow rate 10 kg / hr), and ZrO ₂ φ0.1 mm beads were used. Then, pulverization was performed at 60 to 65 ° C. for 30 minutes (mill rotational speed: 4350 rpm). During this time, at 10 minutes of pulverization, 2.0 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank to adjust the pH to 7.0. Furthermore, 0.9 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank at the time of pulverization 25 minutes, and the pH was adjusted to 6.9.

  In the mill raw material tank in which the obtained calcium carbonate fine particle dispersion is present, the above O / W emulsion is mixed and further pulverized in a bead mill for 30 minutes, and the water of the coated oil particles in which thymol is coated with the fine particles of calcium carbonate. A dispersion was obtained. The pH of this aqueous dispersion was 7.5. Table 1 shows the physical properties of the coated oil particles in this aqueous dispersion.

(Example 7)
The pH adjustment step in Example 1 was as follows. Specifically, 1.9 g of 2N sulfuric acid (manufactured by Junsei Chemical Co., Ltd.) was added to the stock solution tank at 10 minutes of pulverization, the pH was adjusted to 7.0, and 2N sulfuric acid was similarly placed into the stock solution tank at 25 minutes of pulverization. 0.9 g (manufactured by Pure Chemical Co., Ltd.) was added to adjust the pH to 6.9. Otherwise, the same operation as in Example 1 was performed to obtain an aqueous dispersion of coated oil particles obtained by coating a mixture of triclosan and soybean oil with fine particles of calcium carbonate. The pH of this aqueous dispersion was 7.3. Table 2 shows the physical properties of the coated oil particles in this aqueous dispersion.

(Example 8)
The pH adjustment step in Example 1 was as follows. That is, 1.6 g of phosphoric acid (manufactured by Junsei Chemical Co., Ltd.) was added to the stock solution tank at the time of pulverization 10 minutes, the pH was adjusted to 7.0, and phosphoric acid was similarly placed in the stock solution tank at the time of pulverization 25 minutes. 0.8 g of (manufactured by Pure Chemical Co., Ltd.) was added, and the pH was adjusted to 7.0. Otherwise, the same operation as in Example 1 was performed to obtain an aqueous dispersion of coated oil particles obtained by coating a mixture of triclosan and soybean oil with fine particles of calcium carbonate. The pH of this aqueous dispersion was 7.3. Table 2 shows the physical properties of the coated oil particles in this aqueous dispersion.

Example 9
The pH adjustment step in Example 1 was as follows. That is, 3.1 g of a 40% by mass aqueous solution of citric acid monohydrate (manufactured by Kanto Chemical Co., Ltd.) was added to the stock solution tank at the time of pulverization 10 minutes, pH was adjusted to 7.0, and pulverization was at 25 minutes. In the same manner, 1.4 g of a 40% by mass aqueous solution of citric acid monohydrate (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank to adjust the pH to 7.1. Otherwise, the same operation as in Example 1 was performed to obtain an aqueous dispersion of coated oil particles obtained by coating a mixture of triclosan and soybean oil with fine particles of calcium carbonate. The pH of this aqueous dispersion was 7.4. Table 2 shows the physical properties of the coated oil particles in this aqueous dispersion.

(Example 10)
In a 200 mL beaker, 1.4 g of Ryoto Sugar Ester S-1670 (manufactured by Mitsubishi Chemical Foods) is dissolved in 67.2 g of pure water as a nonionic surfactant having a high ability to disperse calcium particles. A mixture prepared by dissolving 0.4 g of the compound triclosan (manufactured by Ciba Specialty Chemicals Co., Ltd.) in 1.0 g of soybean oil (trade name: soybean oil YM / Nisshin Oilio Group Co., Ltd.) was added. The mixture was stirred (10000 rpm, 5 minutes) using a homogenizer (ULTRA-TURRAX T25BASIC manufactured by TKA-WERKE) to prepare an O / W emulsion.

On the other hand, 7 g of calcium carbonate (Porecal-N manufactured by Shiraishi Calcium Co., Ltd.) was dispersed in 343 g of pure water. This was charged into a stock solution tank of a bead mill (Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)), supplied to the mill while being dispersed (flow rate 10 kg / hr), and ZrO ₂ φ0.1 mm beads were used. Then, pulverization was performed at 23 to 25 ° C. for 30 minutes (mill rotational speed: 4350 rpm). During this time, at 10 minutes of pulverization, 2.0 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank to adjust the pH to 7.0. Furthermore, 0.9 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank at the time of pulverization 25 minutes, and the pH was adjusted to 7.0.

  In the mill raw material tank where the obtained calcium carbonate fine particle dispersion is present, the above O / W emulsion is mixed and further pulverized in a bead mill for 30 minutes to coat the mixture of triclosan and soybean oil with calcium carbonate fine particles. An aqueous dispersion of coated oil particles was obtained. The pH of this aqueous dispersion was 7.3. Table 2 shows the physical properties of the coated oil particles.

(Comparative Example 1)
In a 200 mL beaker, 0.4 g of sodium oleate (manufactured by Junsei Kagaku Co., Ltd.) as an anionic surfactant is dissolved in 54 g of pure water, and triclosan (Ciba Specialty Chemicals), which is a phenolic compound, is used as an oil here. Co., Ltd.) 0.8 g of soybean oil (trade name: Soybean oil YM / Nisshin Oillio Group Co., Ltd.) 2.0 g was added and a homogenizer (manufactured by TKA-WERKE ULTRA-TURRAX T25BASIC) ) Was used (10000 rpm, 5 minutes) to prepare an O / W emulsion.

On the other hand, 14 g of calcium carbonate (Porecal-N manufactured by Shiraishi Calcium Co., Ltd.) was dispersed in 686 g of pure water. This was charged into a stock solution tank of a bead mill (Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)), supplied to the mill while being dispersed (flow rate 10 kg / hr), and ZrO ₂ φ0.1 mm beads were used. Then, pulverization was performed at 23 to 25 ° C. for 30 minutes (mill rotational speed: 4350 rpm).

  In the mill raw material tank where the obtained calcium carbonate fine particle dispersion is present, the above O / W emulsion is mixed and further pulverized in a bead mill for 30 minutes to coat the mixture of triclosan and soybean oil with calcium carbonate fine particles. An aqueous dispersion of coated oil particles was obtained. The pH of this aqueous dispersion was 9.9. Table 2 shows the physical properties of the coated oil particles in this aqueous dispersion.

(Comparative Example 2)
On the other hand, 7 g of calcium carbonate (Porecal-N manufactured by Shiraishi Calcium Co., Ltd.) was dispersed in 343 g of pure water. This was charged into a stock solution tank of a bead mill (Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)), supplied to the mill while being dispersed (flow rate 10 kg / hr), and ZrO ₂ φ0.1 mm beads were used. Then, pulverization was performed at 60 to 65 ° C. for 30 minutes (mill rotational speed: 4350 rpm).

  The mill raw material tank in which the obtained calcium carbonate fine particle dispersion is present is mixed with the O / W emulsion shown in Example 2 and further pulverized in a bead mill for 30 minutes to coat triclosan with calcium carbonate fine particles. An aqueous dispersion of oil particles was obtained. The pH of this aqueous dispersion was 9.8. Table 2 shows the physical properties of the coated oil particles in this aqueous dispersion.

(Comparative Example 3)
7 g of calcium carbonate (Porecal-N manufactured by Shiraishi Calcium Co., Ltd.) was dispersed in 343 g of pure water. This was charged into a stock solution tank of a bead mill (Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)), supplied to the mill while being dispersed (flow rate 10 kg / hr), and ZrO ₂ φ0.1 mm beads were used. Then, pulverization was performed at 23 to 25 ° C. for 30 minutes (mill rotational speed: 4350 rpm). During this time, at 10 minutes of pulverization, 2.0 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank to adjust the pH to 7.0. Furthermore, at the time of pulverization 25 minutes, 12.5 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank to adjust the pH to 5.0.

  In the mill raw material tank where the obtained calcium carbonate fine particle dispersion is present, the O / W emulsion shown in Example 1 is mixed and further pulverized in a bead mill for 30 minutes, and the mixture of triclosan and soybean oil is mixed with calcium carbonate. An aqueous dispersion of coated oil particles coated with fine particles was obtained. The pH of this aqueous dispersion was 5.7. Table 2 shows the physical properties of the coated oil particles in this aqueous dispersion.

(Comparative Example 4)
7 g of calcium carbonate (Porecal-N manufactured by Shiraishi Calcium Co., Ltd.) was dispersed in 343 g of pure water. This was charged into a stock solution tank of a bead mill (Ultra Apex Mill UAM-015 (manufactured by Kotobuki Industries Co., Ltd.)), supplied to the mill while being dispersed (flow rate 10 kg / hr), and ZrO ₂ φ0.1 mm beads were used. Then, pulverization was performed at 23 to 25 ° C. for 30 minutes (mill rotational speed: 4350 rpm). During this time, at 25 minutes after pulverization, 0.73 g of 2N hydrochloric acid (manufactured by Kanto Chemical Co., Inc.) was added to the stock solution tank to adjust the pH to 8.6.

  In the mill raw material tank where the obtained calcium carbonate fine particle dispersion is present, the O / W emulsion shown in Example 1 is mixed and further pulverized in a bead mill for 30 minutes, and the mixture of triclosan and soybean oil is mixed with calcium carbonate. An aqueous dispersion of coated oil particles coated with fine particles was obtained. The pH of this aqueous dispersion was 8.3. Table 2 shows the physical properties of the coated oil particles in this aqueous dispersion.

  The physical properties of the aqueous dispersion of coated oil particles obtained by the above operations were evaluated by the methods shown below.

(Evaluation methods)
(A) Average particle size of inorganic particles The average particle size of the hardly water-soluble inorganic calcium salt fine particles is trisodium citrate as a dispersant together with the hardly water-soluble inorganic calcium salt (pure chemical ( Co., Ltd.) was added in an amount of 3 times the weight of the poorly water-soluble inorganic calcium salt and pulverized, and the resulting aqueous dispersion of the poorly water-soluble inorganic calcium salt fine particles was obtained as a dynamic light scattering microtrack UPA-150. The average particle size of inorganic particles was determined by measurement with Nikkiso Co., Ltd.

(B) Average coating thickness The average coating thickness of the coating oil particles with the slightly water-insoluble inorganic calcium salt fine particles is obtained by adding 2% osmium tetroxide aqueous solution to the coating oil particle aqueous dispersion, and then adding water to ethanol, propylene oxide / epoxy resin. Then, the sample was sliced using an ultramicrotome, the cross-section was observed with a transmission electron microscope (TEM), and eight coating layers of each of the ten coated oil particles were measured and calculated by arithmetic mean.

(C) Coated oil particle average particle diameter The coated oil particle average particle diameter was determined by observing the coated oil particles (emulsion) with a transmission electron microscope (TEM) in the same manner as in (b) above. The particle size was measured and calculated by arithmetic mean.

(D) Formation status of coated oil particles The formation status of the coated oil particles was evaluated by observing the obtained sample with a transmission electron microscope or observing that the oil component was not floated and separated in the dispersion. .

(E) Stability of emulsified particles The obtained samples were allowed to stand at harsh conditions of 50 ° C for 1 month, and the stability of the emulsified particles was evaluated by observing the separation of oil. The meanings of the evaluations “◯”, “Δ”, “X” in the table are as follows.
○: Oil separation does not occur even after one month.
Δ: Separation of oil did not occur after 1 week, but separation of oil was observed after 1 month.
X: Separation of oil occurred within one week.

(F) Oil content elution rate (quantification of Comparative Example 2)
Quantified using ¹ H-NMR. About 80 g (weighed) of the obtained aqueous dispersion of coated oil particles is centrifuged at 3000 rpm for 10 minutes using a centrifugal separator 05PR-22 (manufactured by Hitachi, Ltd.), and the sediment and supernatant are decanted. Divided into. The sediment was freeze-dried overnight to obtain a white powder (weighed). The amount obtained by subtracting the amount of the white powder from the amount of the aqueous dispersion of the coated oil particles used for the centrifugation was used as the amount of the supernatant.

  About 20 mg (weighed) of this powder and about 4 mg (weighed) of internal standard 1,1,2,2-tetrachloroethane (weighed) were placed in an NMR tube, and about 0.4 mL of deuterated methanol was added as a solvent. Further, 3 drops of 35% by mass deuterated hydrochloric acid was added to completely dissolve the calcium carbonate film, and the oil was extracted. The peak at 6.5 ppm was 1,1,2,2-tetrachloroethane. This integrated value was set to 2, and the peak area of 7.5 ppm of triclosan was determined. From this value, the content of triclosan in the powder was calculated. The amounts of IPMP, thymol, and soybean oil were measured using heavy chloroform as the solvent in the NMR measurement. The peak at 6.0 ppm is 1,1,2,2-tetrachloroethane. Similarly, the peak areas of IPMP (2.3 ppm), thymol (2.3 ppm), and soybean oil (4.1 to 4.3 ppm) are obtained. The content in the powder was determined (in Comparative Example 2, the powder was 18.1 mg and the internal standard was 4.3 mg, and the triclosan area was 0.1972 → 8.1 mass% with respect to the powder).

  On the other hand, about 250 mg of the supernatant (weighed) and about 4 mg of the internal standard 1,1,2,2-tetrachloroethane (weighed) were placed in an NMR tube, and about 0.4 mL of heavy methanol was added as a solvent. Further, 3 drops of 35% by mass deuterated hydrochloric acid was added. The peak at 6.5 ppm was 1,1,2,2-tetrachloroethane. This integrated value was set to 2, and the peak area of 7.5 ppm of triclosan was determined. From this value, the content of triclosan in the supernatant was calculated. The amounts of IPMP, thymol, and soybean oil were measured using heavy chloroform as the solvent in the NMR measurement. The peak at 6.0 ppm is 1,1,2,2-tetrachloroethane. Similarly, the peak areas of IPMP (2.3 ppm), thymol (2.3 ppm), and soybean oil (4.1 to 4.3 ppm) are obtained. The content in the supernatant was calculated (in Comparative Example 2, the supernatant was 256.9 mg and the internal standard was 4.6 mg, and the triclosan area was 0.0417 → 0.129% by mass with respect to the supernatant). Comparative Example 1 and Comparative Example 4 were also measured by the same method.

  From the above, the weight of each powder and supernatant and the concentration of oil contained in each powder and supernatant were calculated. From these, the amount and ratio of oil contained in each powder and supernatant were calculated. The ratio of the oil contained in the oil was taken as the oil elution rate.

(G) Oil content elution prevention property The oil content elution prevention property was evaluated from said (f) oil content elution rate. The meanings of the evaluations “◯”, “Δ”, “X” in the table are as follows.
◯: The oil elution rate of all the components contained in the oil is 0%, and the oil is stably held in the coated oil particles.
Δ: The oil elution rate of any component contained in the oil component is 0 to 20%, and any component contained in the oil component is partially eluted into the water from the coated oil particles.
×: The oil elution rate of any component contained in the oil component exceeds 20%, and any component contained in the oil component is partially eluted into the water from the coated oil particles.

  From the results of Tables 1 and 2, for Examples 1 to 10, stable coated oil particles obtained by coating oil particles containing an oil component containing a phenolic compound with fine particles of calcium carbonate were obtained, and all contained in the oil component It was confirmed that the oil elution rate of this component was 0%, and the oil content was stably held in the coated oil particles even under the severer condition of 50 ° C.

  On the other hand, from the results of Table 2, in Comparative Examples 1 and 2, pH adjustment was not performed, and the pH of the obtained aqueous dispersion of coated oil particles was 9.8 to 9.9. Since it was higher than the range of 0-8.0, it turned out that only the triclosan which is a phenolic compound is eluting (a soybean oil does not leak).

  Moreover, about Comparative Example 3, although pH adjustment is performed, since the addition amount of hydrochloric acid is large and is lower than the range of 6.0 to 8.0 shown in the present invention, the dissolution amount of calcium carbonate in water is small. It was found that the amount of fine particles of calcium carbonate forming the coated oil particles in the aqueous dispersion of the present invention was decreased, the stability of the coated oil particles was lowered, and the oil content was separated.

  Moreover, about Comparative Example 4, although pH adjustment is performed, the addition amount of hydrochloric acid is small, and the pH of the obtained aqueous dispersion of coated oil particles is 8.3, which is 6.0 to 8 shown in the present invention. Since it was higher than the range of 0.0, it was found that only triclosan, which is a phenolic compound, was eluted.

  As described above, the coated oil particles in the aqueous dispersion of coated oil particles of the present invention are obtained by coating an oil containing a phenolic compound composed of one or more components with fine particles of a poorly water-soluble inorganic calcium salt having an average particle size of 1 μm or less. It was found to be stable coated oil particles having an average particle size of 5 μm or less and a pH in the range of 6.0 to 8.0.

  As described above, the coated oil particles in the coated oil particle aqueous dispersion according to the present invention are composed of medicinal components, cosmetic components, bactericidal components, edible oils, fragrances, pigments, other agricultural chemicals, insecticide components, antibacterial components, antifungal components as oil components Since it is a coated oil particle in which ingredients and the like are stably coated with fine particles of a poorly water-soluble inorganic calcium salt, it is suitable for use in pharmaceuticals, foods, cosmetics, oral products such as toothpastes and mouthwashes.

  Further, the coated oil particles in the aqueous dispersion of the present invention may be used as a personal care product or drug delivery system as a material having a function of releasing the encapsulated oil by dissolution of the coated particles under a specific condition, or a sustained-release preparation. Can be applied to drug carriers.

It is a schematic diagram of the covering oil particle which coat | covered the oil particle with the fine particle of the water poorly soluble inorganic calcium salt. It is the figure which represented typically the state of each component in the manufacturing process of the coating oil particle aqueous dispersion of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fine particle aggregate of poorly water-soluble inorganic calcium salt 1a Fine particle of poorly water-soluble inorganic calcium salt 2 Oil 2a Oil particle 3 Coated oil particle 4 Water 5 Emulsion 6 Inorganic fine particle aqueous dispersion 7 Coated oil particle aqueous dispersion

Claims (3)

A coated oil particle aqueous dispersion in which coated oil particles in which fine particles of a poorly water-soluble inorganic calcium salt are adhered to the surface of oil particles are dispersed in water,
Coated oil particles wherein the poorly water-soluble inorganic calcium salt fine particles have an average particle size of 1 μm or less, the coated oil particles have an average particle size of 5 μm or less, and a pH of 6.0 to 8.0. Water dispersion.   The coated oil particle aqueous dispersion according to claim 1, wherein the oil particles contain a phenolic compound or an oil containing a phenolic compound. An emulsification step of dispersing oil in water to obtain an oil particle dispersion;
The fine particle aggregate of the poorly water-soluble inorganic calcium salt is dispersed in water, and then the fine particle aggregate is pulverized into fine particles having an average particle size of 1 μm or less, and the pH of the dispersion is set in the range of 6.0 to 8.0. An inorganic fine particle aqueous dispersion preparation step to obtain an inorganic fine particle aqueous dispersion by adjusting;
By mixing the oil particle dispersion and the inorganic fine particle aqueous dispersion, the pH of the coated oil particles in which fine particles of poorly water-soluble inorganic calcium salt are adhered to the surface of the oil particles is dispersed in water. A coating oil particle aqueous dispersion preparation step for obtaining a coating oil particle aqueous dispersion of 0 to 8.0,
A method for producing an aqueous dispersion of coated oil particles, comprising:

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