JP5117165B2 - Method for producing oil-in-water emulsion composition - Google Patents

Description

  The present invention relates to a method for efficiently producing a stable oil-in-water emulsion composition in which a large amount of an oil component is uniformly dispersed and has a monodispersed particle size distribution.

  Oil-in-water emulsion compositions are widely used in cosmetics, and their feeling of use is a very important issue. The oil component used in cosmetics is a component necessary for skin care effects such as moisturizing. Conventionally, in order to prepare an oil-in-water emulsion composition in which such an oily component is stably blended, the emulsion particles have been refined. However, when preparing such fine emulsified particles, the type of emulsifier is limited, the content of the emulsifier needs to be increased, a sticky feeling may occur, and some people may feel irritation on the skin. It was.

  An emulsion containing a relatively large amount of an oil component is generally produced industrially using a high-pressure emulsifier for the purpose of efficient crushing, dispersion and emulsification. In Patent Document 1, when an emulsion (emulsion) is produced with a high-pressure emulsifier, a back pressure of 0.2% or more and less than 5% is applied to the pressure applied to the high-pressure emulsification action point of the high-pressure emulsification processing unit. Describes a method for producing an emulsion composition composed of ultrafine emulsion grains. However, although the emulsion composition obtained by this method has fine emulsion particles, the particle diameter is not uniform, and sufficient stability cannot be obtained.

On the other hand, emulsification stability is improved by preparing a monodispersed emulsion composition having a narrow emulsion particle size distribution. As a technique for producing an emulsified dispersion or fine particles having high monodispersibility, a microchannel emulsification technique described in Patent Document 2 is known. This technology gives a uniform structure to the membrane that separates the dispersed phase and the continuous phase, and the standard deviation of the diameter of the fine particles / the average diameter of the fine particles is 0.03 or less. It is to be able to obtain. However, although a uniform emulsified particle diameter can be obtained by this method, the emulsified particle diameter is as large as about 1 μm. Therefore, a method for producing an emulsion composition having a fine emulsion particle diameter and high monodispersibility has been eagerly desired.
International Publication No. 95/35157 Pamphlet JP 2000-273188 A

  An object of the present invention is to provide a method for producing an oil-in-water emulsion composition having finely dispersed particles in which a large amount of oily components are stably emulsified and having a monodispersed particle size distribution.

  The inventors of the present invention have introduced a composition containing (A) a surfactant, (B) an oily component that is liquid at 25 ° C. and (C) water, with a simple structure, while introducing a raw material liquid more than before. It contains a large amount of oily components by emulsification using a atomizer equipped with nozzle means that can secure sufficient impact force while suppressing pressure loss and speed loss and does not cause cracks due to tensile stress inside the member. It was also found that a highly monodispersed and stable oil-in-water emulsion composition can be obtained efficiently even in the system.

That is, the present invention provides (A) a surfactant, (B) a composition containing an oily component that is liquid at 25 ° C. and (C) water as a high-pressure fluid, and nozzle means for causing the high-pressure fluid to collide with each other. And a method for producing an oil-in-water emulsified composition emulsified by a pulverizing apparatus comprising an introduction flow path for introducing the high-pressure fluid into the nozzle means,
The nozzle means has a nozzle body made of a highly rigid material, and a high-pressure fluid collision channel comprising a plurality of through holes formed in the nozzle body from the outer peripheral surface of the nozzle body toward the axis, and these A high-pressure fluid led to the introduction flow path is formed in the axial direction of the nozzle main body. It is introduced from the outer periphery to each outer peripheral side end opening of the collision flow path,
The collision channel includes a large-diameter channel on the downstream side communicating with the outlet channel, and a high-pressure fluid provided on the upstream side of the large-diameter channel and introduced from the outer peripheral end opening. With a small-diameter injection channel that injects into the inside,
The length L ₁ from the outer peripheral side end opening of the injection flow path to the large diameter flow path is 0.15 mm or more and 0.6 mm or less, and the length L ₂ of the large diameter flow path is 1.5 mm or more and 4 mm. Hereinafter, the ratio of the cross-sectional area A _{1 of the} single injection flow path to the cross-sectional area A ₂ of the single large-diameter flow path is 2 ≦ A ₂ / A ₁ ≦ 7, and the cross-sectional area of the injection flow path Method for producing an oil-in-water emulsified composition in which emulsification is performed using a pulverizing apparatus in which the ratio of the total nA _{1 for the} number of flow paths to the cross-sectional area A ₃ of the outlet flow paths satisfies 2 ≦ A ₃ / nA ₁ ≦ 80 Is to provide.
Moreover, this invention provides the oil-in-water emulsion composition obtained by the said manufacturing method.

  According to the present invention, even in a system containing a large amount of an oil component, it is possible to efficiently obtain a very stable oil-in-water emulsion composition in which fine particles are uniformly dispersed and a monodispersed particle size distribution. it can.

The oil-in-water emulsion composition produced in the present invention is not particularly limited, and a stable emulsion composition can be obtained even when a large amount of an oil component is contained.
The oil-in-water emulsion composition obtained by the present invention contains (A) a surfactant, (B) an oily component that is liquid at 25 ° C., and (C) water.

  (A) The surfactant is preferably a hydrophilic surfactant, and is generally used in cosmetics. For example, any of an anionic surfactant, a cationic surfactant, and a nonionic surfactant may be used. Anionic surfactants are preferred. Specifically, higher fatty acid salts such as sodium laurate and potassium palmitate; alkyl sulfate salts such as sodium lauryl sulfate and potassium lauryl sulfate; alkyl ether sulfate salts such as polyoxyethylene lauryl sulfate triethanolamine; lauroyl sarcosine N-acyl sarcosine salts such as sodium; higher fatty acid amide sulfonates such as N-myristoyl-N-methyltaurine sodium; alkyl phosphates such as sodium monostearyl phosphate; polyoxyethylene oleyl ether sodium phosphate, polyoxy Polyoxyethylene alkyl ether phosphates such as sodium ethylene stearyl ether phosphate; Long chain sulfosuccinates such as sodium di-2-ethylhexyl sulfosuccinate; Linear dodecylbenzene Alkylbenzenesulfonates such as sodium sulfonate, linear dodecylbenzenesulfonate triethanolamine; monosodium N-lauroyl glutamate, monosodium N-stearoyl-L-glutamate, disodium N-stearoylglutamate, N-myristoyl-L-glutamic acid Long chain N-acyl glutamates such as monosodium; natural surfactants such as lecithin and hydrogenated lecithin.

  Among these, long-chain N-acyl taurine salts such as N-myristoyl-N-methyltaurine sodium; alkyl phosphates such as sodium monostearyl phosphate, polyoxyethylene oleyl ether sodium phosphate, polyoxyethylene stearyl ether phosphorus Polyoxyethylene alkyl ether phosphates such as sodium acid; long-chain N-acyl glutamates such as monosodium N-lauroyl glutamate, disodium N-myristoyl glutamate, and monosodium N-stearoyl-L-glutamate are preferred. In particular, long-chain N-acyl taurine salts and long-chain N-acyl glutamates having an alkyl chain length of 16 or more are preferred.

  (A) 1 or more types can be used for surfactant, It is preferable to contain 0.01-5 mass% in whole composition, especially 0.1-2.5 mass%.

(B) The oily component is usually used in cosmetics, and is a synthetic and naturally-derived oily component that is liquid at 25 ° C., for example, hydrocarbon oil, ester oil, ether oil, silicone oil, fluorine oil, etc. included.
More specifically, vegetable oils such as jojoba oil; animal oils such as liquid lanolin; hydrocarbon oils such as liquid paraffin and squalane; ester oils such as fatty acid esters, polyhydric alcohol fatty acid esters, glycerin derivatives, and amino acid derivatives; dimethylpolysiloxane , Dimethylcyclopolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, higher alcohol-modified organopolysiloxane and other silicone oils; fluoropolyether, perfluoroalkylether silicone and other fluorine oils; 2-methoxyhexyl paramethoxycinnamate And ultraviolet absorbers.

  (B) 1 or more types of oily components can be used, and it is preferable that it is 0.11-60 mass% in the whole composition from the point of moisture retention and a usability | use_condition, especially 1.1-30 mass%. .

  In the present invention, a small amount of (A) surfactant can be used to emulsify a large amount of (B) oil component, and the mass ratio of component (B) to component (A) should be 11 mass times or more. Preferably, it is 11-38 mass times, More preferably, it is 12-24 mass times, Especially preferably, it can be 15-20 mass times.

In the present invention, the content of (C) water is preferably 10 to 99% by mass, particularly 10 to 95% by mass in the total composition.
Moreover, other aqueous bases, for example, C1-C4 lower alcohols, such as ethanol and propanol, can also be contained.

The oil-in-water emulsion composition of the present invention can further contain (D) an amphiphilic lipid (solid at 25 ° C.), and an emulsion having a fine particle diameter can be obtained with a small number of treatments.
Examples of such amphiphilic lipids include higher fatty acids such as myristic acid and stearic acid; higher alcohols such as cetanol, stearyl alcohol, and behenyl alcohol; sphingosines such as sphingosine; and ceramides. Examples of ceramides include type I described in Robson KJ et al., J. Lipid Res., 35, 2060 (1994), Wertz PW et al., J. Lipid Res., 24, 759 (1983), and the like. -VII ceramides and ceramide analogues described in JP-A-62-228048, etc., and the former commercially available products include ceramide III, ceramide IIIB, ceramide IIIA, ceramide IV, phytoceramide I (and above, degusa). Co., Ltd.), Ceramide II (Cedama Corporation), Ceramide TIC-001 (Takasago Fragrance Co., Ltd.) and the like.

  One or more kinds of amphiphilic lipids can be used, and the total composition preferably contains 0.01 to 20% by mass, particularly 0.1 to 10% by mass.

The oil-in-water emulsion composition of the present invention can further contain (E) a polyhydric alcohol, and an emulsion having a fine particle diameter can be obtained with a small number of treatments.
Examples of the polyhydric alcohol include glycerin, 1,3-butylene glycol, propylene glycol, dipropylene glycol, diglycerin, isoprene glycol, 1,2-pentanediol, xylit, sorbit, polyethylene glycol, and the like.

One or more kinds of polyhydric alcohols can be used, and it is preferable to contain 0.5 to 50% by mass, particularly 0.5 to 30% by mass in the total composition. Moreover, it is preferable that a polyhydric alcohol is 0.8-2 mass times with respect to an oil-based component.
Moreover, (D) amphiphilic lipid and (E) polyhydric alcohol can also be used in combination.

The oil-in-water emulsified composition of the present invention is, for example, a mixture of all components to obtain a crude emulsion, nozzle means for causing this to collide with high-pressure fluid, and for introducing the high-pressure fluid into the nozzle means An atomization device having an introduction channel,
The nozzle means has a nozzle body made of a highly rigid material, and a high-pressure fluid collision channel comprising a plurality of through holes formed in the nozzle body from the outer peripheral surface of the nozzle body toward the axis, and these A high-pressure fluid led to the introduction flow path is formed in the axial direction of the nozzle main body. It is introduced from the outer periphery to each outer peripheral side end opening of the collision flow path,
The collision channel includes a large-diameter channel on the downstream side communicating with the outlet channel, and a high-pressure fluid provided on the upstream side of the large-diameter channel and introduced from the outer peripheral end opening. With a small-diameter injection channel that injects into the inside,
The length L ₁ from the outer peripheral side end opening of the injection flow path to the large diameter flow path is 0.15 mm or more and 0.6 mm or less, and the length L ₂ of the large diameter flow path is 1.5 mm or more and 4 mm. Hereinafter, the ratio of the cross-sectional area A _{1 of the} single injection flow path to the cross-sectional area A ₂ of the single large-diameter flow path is 2 ≦ A ₂ / A ₁ ≦ 7, and the cross-sectional area of the injection flow path It can be manufactured by emulsifying using a pulverizing apparatus in which the ratio of the total nA _{1 corresponding} to the number of channels and the cross-sectional area A ₃ of the outlet channels satisfies 2 ≦ A ₃ / nA ₁ ≦ 80.

  The coarse emulsion means components (A), (B) and (C) and, if necessary, components (D), (E), and other components, and is added above the temperature at which each of them can be dissolved. An oily component and an aqueous component are apparently almost uniformly mixed by heating and propeller stirring or a homogenizer.

  The coarse emulsion is filled in a storage tank in the apparatus, transferred to a connecting pressure-increasing cylinder, and a high pressure is applied. The coarse emulsion is introduced into the atomizer.

  The atomization apparatus used in the present invention is a high-pressure nozzle composed of a plurality of through-holes formed in a nozzle body made of a hard material as nozzle means for causing high-pressure fluids to collide with each other from the outer peripheral surface of the body toward the axis. There are provided a fluid collision flow channel and a discharge flow channel for deriving the fluid after the collision formed along the axial direction from the confluence of the collision flow channels. The atomizing device is provided with a high-pressure fluid that is introduced from the outer periphery of the nozzle body to each outer peripheral end opening of the collision flow channel, and the collision flow channel is downstream of the discharge flow channel. A large-diameter channel on the side, and a small-diameter injection channel provided on the upstream side of the large-diameter channel and for ejecting high-pressure fluid introduced from the outer end opening into the large-diameter channel It is.

  That is, in the nozzle means, an injection flow path and a large-diameter flow path that follows this are provided to form a collision flow path, and the collision flow path is at an angle on a plane perpendicular to the nozzle body axis or more. Therefore, the high-pressure fluid introduced from each outer peripheral end opening of each collision flow channel is on the nozzle body axis via the large-diameter flow channel from each injection flow channel. It progresses toward the confluence, collides at the confluence, and after the collision, it is led out of the nozzle body from the outlet passage formed along the axial direction from the confluence.

  The injection flow path is a flow path having the narrowest cross-sectional area in which high-pressure fluid flows in the nozzle means, and is a flow path in which pressure energy is converted into velocity energy when the high-pressure fluid flows here. In the large-diameter channel communicating with this, the high-pressure fluid ejected from the ejection channel forms a high-speed jet by the ejection force, and this high-speed jet generates a shearing force between the surrounding fluid and a strong liquid-liquid. The atomization is promoted by the shear force between the liquid and the liquid and the jet after passing through the large-diameter channel colliding in the collision space.

  Therefore, in the nozzle means, since the high-pressure fluid can be introduced into the injection flow path without proceeding through the flow path formed by bending in the member, the flow rate can be increased well with almost no pressure loss. A high-speed jet is ejected from the flow channel toward the large-diameter channel, and a good liquid-liquid shearing force can be generated in the large-diameter channel. In the maintained state, a jet sprayed from another large-diameter channel in the same manner collides with the inside of the outlet channel, so that excellent atomization performance can be realized.

  In addition, by defining the design dimensions such as the length and diameter of the injection channel, large-diameter channel, and outlet channel within the specified condition range for the nozzle body, it is more durable while keeping the amount of high-rigid material used low. High performance, high efficiency, and high pressure atomization with a large flow rate can be obtained.

The flow rate is roughly determined by the number n of injection channels and the diameter d ₁ . For example, when the cross-sectional shape of the injection flow path is a perfect circle and n = 2, at a pressure of 245 MPa, a flow rate of 0.5 L / min at d ₁ = 0.1 mm, a flow rate of 4 L / min at d ₁ = 0.25 mm, and d ₁ = The flow rate is 7.5 L / min at 0.35 mm, and the flow rate is 12 L / min at d ₁ = 0.5 mm.

On the other hand, in order to maximize the speed of the high-speed jet, it is desirable to reduce the speed loss due to friction between the inner wall surface of the flow path and the fluid as much as possible by shortening the length L ₁ of the injection flow path. However, if the length is too short, the strength of the nozzle body is not sufficient and causes damage, so a minimum length is necessary. Specifically, it is preferable that the length L ₁ of the injection flow path be in the range of 0.15 mm to 0.6 mm, more preferably 0.25 mm to 0.4 mm.

The high-speed jet from the injection channel is injected into the large-diameter channel, the liquid-liquid shearing with the surrounding fluid in the large-diameter channel, and the jet after passing through the large-diameter channel collide in the collision space. Achieving atomization of raw material liquid. That is, the ratio of the injection passage one cross-sectional area A ₁ and the large-diameter passage one cross-sectional area _{A 2, 2 ≦ A 2 /} A 1 ≦ 7, more preferably 2.5 ≦ A ₂ / A ₁ ≦ By setting it to 6, the shearing force between the liquid and the liquid and the collision energy can be maximized. In addition, it is preferable to provide the injection channel and the large-diameter channel coaxially.

Further, the shear force between the liquid and the liquid and the energy due to the collision can be further increased by setting the length L ₂ of the large-diameter channel to a suitable range. That is, the length L ₂ of 1.5mm or more 4mm large-diameter flow path or less, more preferably by a range of 2mm or 3mm or less, sufficient liquid - to give a shear force between the liquid and the energy The jet can be collided in the outlet channel while maintaining a high level.

Furthermore, the fluid after the collision is discharged from the nozzle body through the outlet channel, but if the outlet channel diameter is too small, the pressure loss in the outlet channel becomes dominant, and the high-speed jet at the outlet of the injection channel Therefore, the outlet flow path diameter may be set to an appropriate size. That is, the ratio of the total nA ₁ of the cross-sectional area of the ejection flow path to the number of flow paths and the cross-sectional area A ₃ of the outlet flow path is 2 ≦ A ₃ / nA ₁ ≦ 80, more preferably 2.5 ≦ A _3. By setting / nA ₁ ≦ 65, the collision speed between jets can be increased, the collision energy can be increased, and the atomization performance can be further improved.

  In addition, as the hard material of the nozzle body, a metal material such as cemented carbide or SUS440C with improved wear resistance, ceramics such as silicon nitride, zirconia, or alumina, diamond, sapphire, ruby, etc. Can be mentioned. It is desirable to use diamond that is particularly excellent in wear resistance as a highly hard material for the injection flow path. In the case of using diamond, in addition to natural diamond with the highest hardness, there are artificial single crystal diamond, artificial polycrystalline diamond, and sintered diamond, and any of them can be used. It is most desirable to use artificial single crystal diamond because it is obtained and easily available.

  Moreover, since the collision flow path of the nozzle body is mainly composed of a downstream large-diameter flow path and an upstream injection flow path, these flow paths are formed in separate members, It is possible to configure in combination so as to communicate with each other. In this case, only the injection flow path that requires high durability can be formed of a highly rigid material such as diamond, and the other flow paths can be formed of another highly rigid material that is inexpensive and excellent in workability.

  That is, the outlet channel and all large-diameter channels communicating with the first channel are formed as the first member, and each injection channel is formed as the second member corresponding to the number of the collision channels, If the nozzle body is configured such that each injection flow path communicates with the corresponding large diameter flow path in a state where the second member is fitted in the recess formed at the end of the large flow diameter flow path, the overall dimensions of the nozzle main body can be reduced. Since the first member is determined and each second member is much smaller, only the second member is made of expensive diamond, and the first member has sufficient strength for the large-diameter channel and the outlet channel. If it is made of an inexpensive, high-hard material, it is possible to easily increase the size of the nozzle body for increasing the flow rate of the atomization process at a low cost.

  If the angle formed between the ejection direction of the outlet flow path provided along the axial direction and the collision flow path, that is, the large diameter flow path is defined as the opening angle, the large diameter flow path has an angle of 90 degrees with respect to the axial center. When communicating with the outlet channel, the collision channel and the outlet channel form a T shape in a side view. If the opening angle exceeds 90 degrees with respect to the axis, the collision flow channel and the discharge flow channel form a substantially Y shape in a side view.

  The jet that has flowed out of the large-diameter channel collides in the outlet channel, but if the outlet direction of the outlet channel and the opening angle of the large-diameter channel are 90 degrees and the large-diameter channel is opposed to the jet, Therefore, high-precision centering is required for reliable collision, and even when jets reliably collide at the start of use, the shaft may change due to long-term use and damage each other There is. However, if the opening angle exceeds 90 degrees, the jets merge at a line, so if the jets face each other on a plane orthogonal to the axis, the jets will collide even if the opening angle changes due to processing or usage. To do. That is, by setting the opening angle to 95 degrees or more and 150 degrees or less, the collision probability of the jet flow can be improved and the atomization performance can be improved.

  In the nozzle means, since the pressure of the high-pressure fluid is applied to the entire outer periphery of the nozzle body, the internal pressure can be canceled out, so that the diameter increases from the outer peripheral side end in the direction of each collision flow channel toward the outside. The tapered opening can provide a smoother introduction of the high-pressure fluid, and the jet flow path, which is a substantially small aperture area, can be shortened, resulting in a speed due to wall resistance. Loss can be further reduced.

When forming such a tapered opening portion, the length L ₁ of the substantial injection passage, as shown in FIG. 3 (a), the region from the open end exposed to the nozzle body surface reaches the large diameter flow channel Of these, it is the length excluding the taper-shaped part. That is, by forming the taper-shaped part at the outer peripheral side opening in the direction of the injection flow path, the fluid resistance is further reduced, and the inside of the large-diameter flow path at a higher speed. And a strong liquid-liquid shear around the high-speed jet in the large-diameter channel and high-speed fluid collision in the outlet channel can be realized. As described above, when the injection flow path is formed in the second member different from the first member in which the large-diameter flow path is formed, this tapered opening portion is also continuously the same as the injection flow path. What is necessary is just to form in a 2nd member.

  In addition, the cross-sectional shapes of the injection flow channel, large-diameter flow channel, and outlet flow channel are preferably circular from the viewpoint of reducing friction loss between the fluid and the inner wall surface of the flow channel, ease of processing, and mechanical strength. Since the cross section of the high-speed jet injected from the injection flow path is also a circle, it is difficult to collide with high accuracy. However, if the cross section is rectangular and the collision flow path is provided in the direction parallel to the plane perpendicular to the axis, the collision probability of the jet in the collision space is improved and the surface area of the high-speed jet is increased. Therefore, the shear force between the liquid and the liquid can also be improved. That is, if the cross section of the injection channel and the large-diameter channel is rectangular, durability and atomization performance can be further improved.

Furthermore, the outlet channel may have a tapered shape that expands toward the downstream outlet side opening. In this case, the outlet channel cross-sectional area A ₃ can be represented by the cross-sectional area of the collision space 14X having no taper portion.

  In the nozzle means, the collided fluid led out from the lead-out channel of the nozzle body is sent to the outside of the device via the lead-out channel provided in the housing member of the atomization device in which the nozzle body is installed. For derivation without leakage, it is necessary that the derivation flow path on the nozzle body side and the derivation flow path on the apparatus housing member side communicate with each other in a good sealed state.

  Therefore, it is only necessary to provide sealing means for pressing the nozzle body against the housing member in a state where the outlet channel of the nozzle body is positioned coaxially with respect to the outlet channel on the housing member side. As the sealing means, since the nozzle body can use the pressure generated when the high-pressure fluid is introduced, there is no need for a fastening means such as a screw that is difficult to adjust, and a simple means using the biasing force of the spring is sufficient. is there.

  In addition, when cavitation is generated in the injection flow channel, large-diameter flow channel, and outlet flow channel, in the nozzle means in which the conventional plates are firmly fixed to each other with screws, vibrations due to pressure fluctuations due to cavitation are generated in the screw hole portions. There was a risk of damage to the screw hole due to loosening of the affected screw or vibration of the screw itself, but in the present invention, not only the nozzle body itself consisting of one member but also sealing means using a spring Since there is no need to provide a screw hole or the like between the pressed device housing member side, there is no possibility of being adversely affected by vibration. Rather, even in a press-fixed state using only a spring, an effect of preventing the axial displacement of the nozzle means with the lead-out flow path on the housing side can be expected due to the vibration absorbing and mitigating action of the spring.

  As described above, the nozzle means described in detail can be used for atomization without particularly specifying the processing raw material, but in a large-diameter channel connecting high-speed fluid while suppressing loss due to friction between the fluid and the solid wall as much as possible. By jetting, a strong liquid-liquid shearing force can be generated around the high-speed jet, and then the jets can collide more efficiently. For this reason, the performance which was especially excellent in atomization of the dispersion system which is a liquid in a continuous phase and a dispersed phase, ie, an emulsion, is exhibited.

  In the present invention, the fluid pressure before passing through the collision flow path is preferably 70,000 to 245,000 kPa, particularly 120000 to 210000 kPa, whereby emulsified particles having a fine and highly monodisperse particle size distribution can be obtained.

Further, in the present invention, applying a back pressure of 5 to 20%, particularly 5 to 10%, with respect to the pressure applied to the fluid collision part can obtain a fine emulsion more efficiently and with a small number of treatments. It is preferable because fine emulsified particles can be obtained. The back pressure refers to the pressure immediately after passing through the nozzle of the atomizer.
The device for applying the back pressure can be handled by a valve that adjusts the outflow amount of the composition, and can be directly attached to the outlet side of the fluid collision part or connected to the outlet side pipe by a pressure-resistant joint or the like. it can.

  Conventionally, when a large amount of an oil component is finely emulsified, a high processing pressure has to be applied in order to generate strong shear energy, which has been a factor in shortening the life of a high-pressure emulsifier. In the present invention, by selecting the structure of the high-pressure emulsification processing section, the processing pressure required for making the emulsified particles finer can be lowered than before. This is very effective not only in terms of structural energy saving but also in that the load on the durability of the fluid collision device can be greatly reduced. The resulting emulsified particles have a small particle size, are monodispersed, have high transparency, and provide an oil-in-water emulsion composition with excellent stability. In addition, since the pressure energy is efficiently converted as the energy for refining oil droplets, the amount of generated heat can be suppressed, and the attached cooling device can be simplified.

  Furthermore, it is preferable to set the average liquid temperature during the fluid collision treatment or immediately after the treatment to 80 ° C. or lower because fine particles are more uniformly dispersed and a highly transparent and stable emulsion composition can be obtained. Specifically, it is preferable to cool the emulsified liquid immediately after passing through the fluid collision treatment unit, and it is preferable to arrange the cooling device within 25 cm, particularly within 15 cm from the fluid collision treatment unit opening. Although there are cases where a cooling device is arranged in a commercially available high-pressure emulsifier, the position of the cooling device is usually a position far from the opening of the high-pressure emulsification treatment part (separated from 25 cm), and the cooling effect is not sufficient Absent.

  According to the present invention, the average particle diameter of the oil droplets emulsified in fine particles is preferably 0.01 to 0.5 μm, particularly preferably 0.025 to 0.2 μm, more preferably 0.025 to 0.1 μm. An emulsified composition can be obtained. Furthermore, the particle size distribution of the finely emulsified particles is monodispersed, and the CV value representing the monodispersity of the particle size distribution is preferably 3 to 50%, particularly preferably 5 to 25%, and more preferably 7 to 10%. An emulsified composition can be obtained.

The CV value is calculated as a ratio of the standard deviation with respect to the average particle diameter. The average particle size and standard deviation are measured by a particle size measuring device based on the dynamic light scattering method. For example, LB-500 manufactured by HORIBA, Ltd., DLS-7000 manufactured by Otsuka Electronics, etc. can be used. When the sample concentration is high, internal light scattering (multiple scattering) occurs, so it is necessary to use a sufficiently diluted sample. For example, in LB-500 manufactured by HORIBA, the sample concentration is diluted so as to be in the range of 0.5 V to 16.0 V, which is indicated by voltage. Further, at the time of measurement, the dispersion medium viscosity at the measurement temperature must be input. Usually, it is often diluted with water, and a numerical value obtained by correcting the temperature of the viscosity of water is used. Scattered light hitting the particles is detected by a detector as a light fluctuation signal according to the particle diameter, and the average particle diameter and particle size distribution are calculated by the analysis. In this case, various calculation methods are employed. In this measurement, the volume-based particle size distribution and the median average particle size were used.
By being finely emulsified with high monodispersibility in this way, the emulsion composition has high transparency and stability, and a stable oil-in-water emulsion can be obtained even if a large amount of oily components are contained. Can do.

The oil-in-water emulsion composition obtained according to the present invention can be suitably used as it is as a cosmetic, particularly as a highly transparent cosmetic.
In addition, the oil-in-water emulsion composition obtained by high-pressure emulsification is diluted with an aqueous component such as water, or those obtained by adding a water-soluble active ingredient or additive thereto, for example, a lotion or a cosmetic liquid. It can be used as a cosmetic. The oil-in-water emulsion composition obtained by the present invention maintains the emulsified state obtained by high-pressure emulsification even when an aqueous component such as water is further added by dilution, and the average particle size of oil droplets is 0.01. A cosmetic material having a transmittance of 45 to 90% can be obtained.

  Examples of such active ingredients and additives include water-soluble vitamins such as ascorbic acid, nicotinic acid amide, and nicotinic acid; , Hamamelis extract, placenta extract, seaweed extract, maroonnier extract, yuzu extract, eucalyptus extract, asunalo extract, etc., animal and plant extracts; potassium hydroxide, sodium hydroxide, triethanolamine, sodium carbonate, citrate, tartaric acid PH adjusters such as salt, lactate, phosphate, succinate, adipate; carboxyvinyl polymer, sodium alginate, carrageenan, carboxymethylcellulose, hydroxyethylcellulose, guar gum, xanthan gum, carboxymethyl Chitosan, and the like thickeners such as sodium hyaluronate.

Reference example 1
As the atomization apparatus 1 used in the present invention, two collision flow paths are configured by a nozzle means for colliding high-pressure fluids of raw material liquids, and an injection flow path and a large-diameter flow path arranged coaxially. The downstream large-diameter channel and the axial center are provided on the same plane at an angle with respect to the axial center, and the large-diameter channel and the outlet channel along the axial direction are provided in a substantially Y shape in a side view. FIG. 1 shows an apparatus having a nozzle body. FIG. 1A is a side sectional view showing a schematic configuration of the atomization apparatus 1, and FIG. 1B is an enlarged view of a nozzle body portion. The atomizing device 1 is urged by a spring 5 from a holding member 7 on the plug member 6 side and a housing 2 side in a chamber 9 formed inside by fitting a plug member 6 to a substantially cup-shaped housing 2. The nozzle body 10 is held between the nozzle holder 3 and the nozzle holder 3.

  The nozzle body 10 includes a large-diameter channel 13 formed in the first member 11 made of a highly hard material such as a cemented carbide, for example, at an angle with respect to the axial center so as to face each other in the axial direction, and the large-diameter channel 13. A lead-out flow path 14 for leading the fluid after the collision formed along the axial direction from the merging point between each other is provided in a substantially Y shape, and is provided at each large-diameter flow path opening end of the first member 11. The second member 16 made of a highly hard material such as single crystal diamond in which the injection flow path 12Y is formed is fitted to the formed recess 11x, respectively. The first member 11 and the second member 16 are joined and fixed by brazing, for example, silver brazing.

  Each second member 16 is formed with an injection flow path 12Y having a tapered opening portion 12X that expands toward the outside, and each injection flow path 12Y is fitted in the recess 11x. The injection channel is configured to communicate coaxially with the large-diameter channel 13. An introduction flow path 15 for introducing a high-pressure fluid into the nozzle body 10 is formed in the outer space of the nozzle body 10 between the nozzle holder 3 and the holding member 7 on the plug side.

  Therefore, the high-pressure fluid that is the material to be subjected to the collision treatment is sent from the end of the housing 2 to the introduction passage 15 through the supply passage 4 formed in the chamber 9 and the nozzle retainer 3, and from the introduction passage 15 to the nozzle body. 10 is supplied in a state where pressure is applied to the entire outer peripheral surface of the nozzle 10, and is guided to the injection flow passage 12Y from the tapered opening 12X of each second member 16 that opens to the outer peripheral surface of the nozzle body, and is supplied to each large-diameter flow passage 13 as a high-speed jet. After being jetted, each jet is sent to the collision space 14X and collides at a confluence on the axis.

  Therefore, in the atomization apparatus 1 including the nozzle body 10 having the above-described configuration, the high-pressure fluid does not travel through the collision flow path that is bent in the nozzle body 10, so that the collision occurs with little pressure loss. It is introduced into the space 14X.

  Further, in the atomization apparatus 1, the nozzle body 10 is composed of two kinds of members, the injection flow path 12Y uses a high-hard material such as diamond, and the other large-diameter flow path 13, the discharge flow path 14 and the like are inexpensive and high. A hard material was used. Thereby, an inexpensive and free flow path design can be performed.

  In addition, the introduction and acceleration of the high-pressure fluid become smoother by providing the tapered opening portion 12X whose diameter increases from the outer peripheral side end of each ejection flow path 12Y toward the outside. In the tapered opening portion 12X, a tensile stress is generated when the high-pressure fluid is introduced, but there is no problem because the high-pressure fluid pressure is applied to the entire outer peripheral surface of the nozzle body 10 as described above.

  When such a tapered opening portion 12X is provided, it is possible to eliminate resistance when the high-pressure fluid is introduced into the ejection flow path due to contraction of the high-pressure fluid, and a good jet can be formed.

  In addition, when a collision flow path composed of an injection flow path and a large-diameter flow path is provided at an angle with respect to the axis rather than on a plane orthogonal to the axial direction, the jet collides more reliably in the collision space 14X. High impact energy can be obtained, and the possibility of damaging the large-diameter channel facing the jet can be reduced. Furthermore, the jet flow channel and the large-diameter channel are rectangular slits, and the shape of the high-speed jet is flattened, so that the shear force between the liquid and the liquid in the large-diameter channel 13 is increased, and the jets in the collision space 14X are accurately It can collide and can improve atomization performance.

  Furthermore, in the atomization apparatus 1, the nozzle body 10 is pressed and fixed to the apparatus housing side, here, the pressing member 7, and the contact surface is well sealed to lead out the discharge passage 14 of the nozzle body 10 and the housing side. As a sealing means for preventing fluid leakage with the flow path 8, a nozzle presser 3 by a spring 5 is provided.

  The nozzle body 10 in the atomization apparatus 1 is composed of two types of members, a first member 11 and a second member 16, and is injected into an inexpensive high-rigid material provided with a large-diameter channel 13 and a lead-out channel 14. The second member 16 using a high-hardness material such as diamond in which the passage 12Y is formed is incorporated, and the high-pressure fluid is filled in the introduction flow path 15 so that the entire outer periphery of the nozzle body 10 has a high pressure. Since the fluid pressure is applied, there is no need for a tightening means that is difficult to adjust and adjust, and there is a risk of member damage such as screwing, as in the case where it is configured by overlapping two conventional plates. A simple seal utilizing the biasing force of the spring 5 can provide a good seal between the nozzle body 10 and the housing, and fluid leakage can be sufficiently prevented.

In addition, in the atomization apparatus 1, although the case where the derivation | leading-out flow path 14 was a cross-sectional circle and the exit side was diameter-expanded was shown, the shape of an derivation | leading-out flow path is not limited to this, The actual atomization process As long as a collision space is formed in which good collision conditions can be obtained and the fluid after the collision can be led out more smoothly according to the raw material liquid and each condition. The outlet flow passage cross-sectional area A ₃ is defined by the cross-sectional area of the collision space 14X having no taper portion.

For example, FIG. 2 ((a) is a sectional side view of the nozzle body, (b) is a sectional view taken along the line AA in (a),
(C) is the same as the nozzle body 20 shown in (a) BB cross-sectional view), and the first member 21 has a substantially rectangular cross section and is formed with the same cross sectional area from the collision space to the outlet side. An outlet channel 24 is exemplified. By setting the lead-out flow path 24 to have a substantially rectangular cross section, the area in the lateral direction is expanded, and the raw material liquid after the collision flows smoothly without changing the collision distance.

  As a more specific embodiment, there can be mentioned an atomization apparatus constructed as shown in FIG. 1 by incorporating each type of nozzle body (30, 40) shown in FIGS.

  As shown in the side sectional view of FIG. 3A, the nozzle body 30 of the type in FIG. 3 is formed with a tapered opening portion 32 </ b> X that extends outward from the outer peripheral side end of the injection flow path 32 </ b> Y. The cross-sectional shape of the radial channel 33 is circular. 3B is a cross-sectional view taken along the line AA in FIG. 3A, and FIG. 3C is a cross-sectional view taken along the line BB in FIG.

  Further, as shown in the side sectional view of FIG. 4A, the nozzle body 40 of the type in FIG. 4 is formed with a tapered opening portion 42 </ b> X that extends outward from the outer peripheral side end of the injection flow path 42 </ b> Y, The cross-sectional shape of the large-diameter channel 43 is rectangular. 4B is a cross-sectional view taken along the line AA in FIG. 4A, and FIG. 4C is a cross-sectional view taken along the line BB in FIG.

  In any type of nozzle body (30, 40), the injection flow path (32Y, 42Y) is formed in the second member (36, 46) made of diamond, and the first member (31, 41) such as cemented carbide. When the second member (36, 46) is fitted in the concave portion at the end of the large-diameter channel (33, 43) formed in the nozzle, the injection channel and the large-diameter channel are connected coaxially for collision. A flow path is constituted. In all cases, the number of collision channels n = 2.

  In the above description, the case where the nozzle body has a collision channel formed of two through holes facing the shaft center from the outer peripheral surface at an angle with respect to the shaft center and having a substantially Y shape with the lead-out channel is shown. However, the present invention is not limited to this. For example, a collision flow path (an injection flow path 52Y and a large-diameter flow path 53) including three or more through holes formed radially at equal angular intervals as shown in FIG. The number and arrangement of the collision flow paths may be appropriately selected according to the actual raw material liquid and the treatment conditions, as long as the collision treatment efficiency is desired.

Examples 1-3
An oil-in-water emulsified composition of the type shown in FIG. 3 was manufactured using the atomizing apparatus constructed as shown in FIG. 1 by incorporating the nozzle body 30 having the nozzle shape shown in Table 1.
That is, 250 g of liquid paraffin, 15 g of sodium N-stearoyl-L-glutamate, 30 g of stearic acid, 200 g of glycerin and 505 g of purified water were mixed, heated and mixed at 80 ° C., and stirred with a homogenizer to obtain a crude emulsion. From the raw material tank containing the coarse emulsion, the treated liquid discharged from the outlet flow path of the atomizer is sent to the atomizer via the high-pressure pump at an operating pressure of 175 MPa. 15 MPa) to the cooler (cooling water inlet temperature 15 ° C.), and after cooling, it is recovered again in the raw material tank, and the next collision treatment process is repeated.

  The collision treatment was repeated 5 times, and the recovered liquid was cooled to room temperature to obtain an oil-in-water emulsion composition. The obtained composition was diluted 100 times with water, and using a light scattering particle size distribution analyzer (LB-500, manufactured by Horiba, Ltd.), the median average particle diameter and standard deviation were measured, and the CV value was calculated. did. The results are also shown in Table 1.

Comparative Examples 1 and 2
The crude emulsion prepared under the same procedure and conditions as in Examples 1 to 3 was processed with an existing high-pressure atomizer to obtain an oil-in-water emulsion composition. The obtained emulsified composition was diluted 100 times with water, and the median average particle size and standard deviation were measured using a light scattering particle size distribution analyzer (LB-500, manufactured by HORIBA, Ltd.). Was calculated. The results are shown below.

(Comparative Example 1)
High-pressure atomizer: Microfluidizer M-140K (manufactured by microfluidics),
Equipped with standard Y-type chamber.
Average particle size 0.070μm, CV value 63%
(Comparative Example 2)
High pressure atomizer: Optimizer HJP-25005 (manufactured by Tau Technology),
Equipped with standard liquid-liquid collision chamber.
Average particle size 0.120 μm, CV value 71%

Examples 4-9, Comparative Examples 3-6
The storage stability was evaluated for the emulsion compositions obtained in Examples 1 to 3 and Comparative Examples 1 and 2 and the emulsion compositions obtained by diluting these emulsion compositions 10 times with purified water. The appearance at the start of storage was transparent, and the appearance after storage was evaluated by visual observation. When transparent, it was indicated as ◯, when it was translucent: Δ, and when it was cloudy: ×. The results are shown in Table 2.

Example 10
An oil-in-water emulsified composition of the type shown in FIG. 4 was manufactured using a micronizer configured as shown in FIG. 1 by incorporating a nozzle body 40 having the nozzle shape shown in Table 3.
That is, 25 g of sodium N-myristoyl-N-methyltaurine, 100 g of squalane, 200 g of dimethylpolysiloxane (6cs), 20 g of ceramide III, and 450 g of glycerin were added with 205 mL of purified water and stirred with a homogenizer to obtain a crude emulsion. This crude emulsion was repeatedly processed 5 times with a refining device at a processing pressure of 180000 kPa and a back pressure of 10500 kPa to obtain an oil-in-water emulsion composition.
The obtained composition was diluted 100 times with water, and using a light scattering particle size distribution analyzer (LB-500, manufactured by Horiba, Ltd.), the median average particle diameter and standard deviation were measured, and the CV value was calculated. did. The results are also shown in Table 3.
250 mL of this composition was mixed with 750 mL of 4% magnesium ascorbate aqueous solution to obtain a cosmetic liquid having a transparent appearance. As a result of storing this cosmetic liquid in an environment of 5 ° C., 20 ° C., and 30 ° C. for 6 months, no change was observed in its appearance.

Example 11
To 30 g of polyoxyethylene oleyl ether sodium phosphate, 330 g of dimethylpolysiloxane (6 cs), 10 g of ceramide III, and 200 g of glycerin, 430 mL of purified water was added and stirred with a homogenizer to obtain a crude emulsion. This coarse emulsion is of the type shown in FIG. 3 and incorporated with a nozzle body 30 having the nozzle shape of Example 2 shown in Table 1 and processed at a processing pressure of 125,000 kPa in a micronizer configured as shown in FIG. Then, it was repeatedly treated 7 times at a back pressure of 12,000 kPa to obtain an oil-in-water emulsion composition.
The obtained oil-in-water emulsion composition had an average particle size of 0.041 μm and a CV value of 9%. As a result of storing this emulsion for 6 months in an environment of 5 ° C., 20 ° C., and 40 ° C., no change was observed in its appearance.

Comparative Example 7
The crude emulsion having the same composition as that of Example 11 was treated 10 times with the refining apparatus used in Comparative Example 1 at a treatment pressure treatment pressure of 125,000 kPa and a back pressure of 12,000 kPa, to obtain an oil-in-water emulsion composition. It was.
The resulting oil-in-water emulsion composition had an average particle size of 0.043 μm and a CV value of 63%. As a result of storing this emulsion for 6 months in an environment of 5 ° C, 20 ° C, and 40 ° C, no change was observed in the appearance at 20 ° C, but creaming was observed at 5 ° C and 40 ° C.

It is a schematic block diagram of an example of the atomization apparatus used by this invention. (A) is a sectional side view showing a schematic configuration of the atomization apparatus, and (b) is an enlarged view of a nozzle body portion. It is a schematic block diagram which shows another example of the nozzle main body in the atomization apparatus used by this invention. (A) is a sectional side view, (b) is an AA sectional arrow view of (a), and (c) is an BB sectional arrow view of (a). In the atomization apparatus used by this invention, it is a schematic block diagram of the nozzle means in case an injection flow path and a large diameter flow path are cylinders. (A) is a nozzle body in which a tapered opening portion is formed outward from the outer peripheral side end of the injection flow path, and both the injection flow path and the large-diameter flow path have a circular cross-sectional shape, and (b) is an A in (a). -A sectional view (enlarged view), (c) is a BB sectional view (enlarged view) of (b). In the atomization apparatus used by this invention, it is a schematic block diagram of a nozzle means in case an injection flow path and a large diameter flow path are rectangles. (A) is a nozzle body having a tapered opening portion formed outwardly from the outer peripheral side end of the injection flow path, and both the injection flow path and the large diameter flow path have a rectangular cross-sectional shape, and (b) is an A in (a). -A sectional view (enlarged view), (c) is a BB sectional view (enlarged view) of (b). It is a sectional side view which shows the structure of the other nozzle main body in the atomization apparatus used by this invention.

Explanation of symbols

1: Atomization device 2: Housing 3: Nozzle holder 4: High-pressure fluid supply channel 5: Spring 6: Plug member 7: Holding member 8: Outlet channel 9: Chamber 10, 20, 30, 40, 50: Nozzle body Means 11, 21, 31, 41, 51: first member 11X: recesses 12X, 22X, 32X, 42X, 52X: tapered opening portions 12Y, 22Y, 32Y, 42Y, 52Y: injection passages 13, 23, 33, 43, 53: Large-diameter channels 14, 24, 34, 44, 54: Derived channels 14X (of the nozzle body): Collision space 14Y: Tapered outlet 14L: Collision distance 15: Introduction channels 16, 26, 36, 46 , 56: second member

Claims (6)

(A) a surfactant, (B) a composition containing an oily component that is liquid at 25 ° C. and (C) water as a high-pressure fluid, and nozzle means for causing the high-pressure fluid to collide with each other, to the nozzle means A method for producing an oil-in-water emulsified composition emulsified by a atomizer equipped with an introduction flow path for introducing the high-pressure fluid,
The nozzle means has a nozzle body made of a highly rigid material, and a high-pressure fluid collision channel comprising a plurality of through holes formed in the nozzle body from the outer peripheral surface of the nozzle body toward the axis, and these A high-pressure fluid led to the introduction flow path is formed in the axial direction of the nozzle main body. It is introduced from the outer periphery to each outer peripheral side end opening of the collision flow path,
The collision channel includes a large-diameter channel on the downstream side communicating with the outlet channel, and a high-pressure fluid provided on the upstream side of the large-diameter channel and introduced from the outer peripheral end opening. With a small-diameter injection channel that injects into
The large-diameter channel and the outlet channel form a substantially Y shape in side view,
The length L ₁ from the outer peripheral side end opening of the injection flow path to the large diameter flow path is 0.15 mm or more and 0.6 mm or less, and the length L ₂ of the large diameter flow path is 1.5 mm or more and 4 mm. Hereinafter, the ratio of the cross-sectional area A _{1 of the} single injection flow path to the cross-sectional area A ₂ of the single large-diameter flow path is 2 ≦ A ₂ / A ₁ ≦ 7, and the cross-sectional area of the injection flow path Method for producing an oil-in-water emulsified composition in which emulsification is performed using a pulverizing apparatus in which the ratio of the total nA _{1 for the} number of flow paths to the cross-sectional area A ₃ of the outlet flow paths satisfies 2 ≦ A ₃ / nA ₁ ≦ 80 .   The production method according to claim 1, wherein the oil-in-water emulsion composition has an oil droplet average particle size of 0.01 to 0.5 µm and a CV value of 3 to 50%.   The production method according to claim 1 or 2, wherein the oil-in-water emulsion composition has a mass ratio of (B) component / (A) component of 11 times or more.   The production method according to any one of claims 1 to 3, wherein the oil-in-water emulsion composition further comprises (D) an amphiphilic lipid.   The production method according to any one of claims 1 to 4, wherein the oil-in-water emulsion composition further comprises (E) a polyhydric alcohol.   The oil-in-water type emulsion composition obtained by the manufacturing method of any one of Claims 1-5.

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