JP6626925B2 - Method for producing emulsion - Google Patents

Description

  The present invention relates to a method for producing an emulsion.

  A method for producing an emulsion using a micromixer is known.

  Patent Literature 1 discloses a method for producing an emulsion in which an aqueous component and an oil component are caused to flow through pores of a micromixer and collide with each other.

  Patent Document 2 discloses that an aqueous component is fluidized, an oily component containing a molten ceramide and a nonionic surfactant is fluidized, and a fluid obtained by combining the fluidized components is passed through pores of a micromixer to form an emulsion. A method for producing a ceramide fine particle dispersion in which a ceramide is prepared and then cooled to solidify ceramide is disclosed.

  Patent Document 3 discloses a method for producing an emulsion in which a silicone oil containing sorbitan monooleate as a surfactant is made to flow while water is made to flow, and a fluid obtained by combining these is passed through the pores of a micromixer. A method is disclosed.

JP 2008-142588 A JP 2008-037842 A JP 2006-507921 A

  However, in the technique disclosed in Patent Document 1, since a surfactant is contained in the aqueous component, in order to obtain an emulsion of fine emulsified droplets, a large amount of the aqueous component is required based on the amount of the oil component. It is necessary to contain a surfactant.

  In the technique disclosed in Patent Document 2, since the oily component contains ceramide which is a solid fat, particles obtained after cooling are not emulsified droplets but solid dispersed particles.

  In the technique disclosed in Patent Document 3, it is difficult to obtain an emulsion of fine emulsified droplets because the HLB of the surfactant contained in the silicone oil is low.

  An object of the present invention is to produce an emulsion in which emulsified droplets of an oil component having a small average particle size are dispersed in an aqueous component using a small amount of a surfactant.

The present invention relates to a joining step of joining a liquid aqueous component and a liquid oil component containing an oil agent that is liquid at 20 ° C. and containing 10% by mass or less of a nonionic surfactant having an HLB of 7 or more,
A pore flowing step of flowing the fluid after the water component and the oil component are merged in the pores in the merging step,
A method for producing an emulsion in which the oil component is dispersed in the aqueous component, wherein the average particle diameter of emulsified droplets (hereinafter, also simply referred to as “droplets”) is 1/100 or less of the pore diameter of the pores. It is.

  According to the present invention, a liquid aqueous component is combined with a liquid oil component containing an oil agent that is liquid at 20 ° C. and containing 10% by mass or less of a nonionic surfactant having an HLB of 7 or more, and By allowing the fluid after the confluence to flow through the pores, it is possible to produce an emulsion in which droplets of an oil component having a small average particle diameter are dispersed in an aqueous component using a small amount of a surfactant.

It is a figure showing composition of an emulsion production system. FIG. 2 is a partial longitudinal sectional view of a main part of the micromixer having the first configuration. FIG. 3 is a sectional view taken along the line III-III in FIG. 2. FIG. 5A is a partial vertical cross-sectional view of a main part in a modification of the micromixer having the first configuration, and FIG. 4B is a cross-sectional view taken along line IVB-IVB in FIG. It is a longitudinal section of the micro mixer of the 2nd composition. It is a longitudinal section of a modification of the micro mixer of the 2nd composition. (A) Partial vertical cross-sectional view of a main part of the micromixer of the third configuration, (b) VIIB-VIIB cross-sectional view in FIG. 7 (a), and (c) VIIC-VIIC cross-sectional view in FIG. 6 (a) FIG. It is (a) partial longitudinal cross-sectional view of the principal part in a modification of the micromixer of the third configuration, and (b) is a VIIIB-VIIIB cross-sectional view in FIG. 8 (a). (A) is a longitudinal sectional view showing a dimensional configuration of a micromixer of a second configuration used in Example 4. (B) is a partial longitudinal sectional view showing a dimensional configuration of a micromixer of a third configuration used in Example 5.

  The method for producing an emulsion according to the present embodiment comprises a liquid aqueous component and a liquid oil component containing an oil agent that is liquid at 20 ° C. and containing a nonionic surfactant having an HLB of 7 or more and 10% by mass or less. And one or two of the aqueous component before merging in the merging step, the oily component before merging in the merging step, and the fluid after merging the aqueous component and the oily component in the merging step At least one pore is passed through pores having a pore diameter of 0.1 to 3 mm. In the method for producing an emulsion according to the present embodiment, an emulsion is prepared in which droplets of an oil component having an average particle size of 1/100 or less of the pore diameter are dispersed in the aqueous component.

  Generally, in the field of cosmetics and the like to be applied to the skin and the like, it is desired to emulsify an oil with a small amount of a surfactant. On the other hand, according to the method for producing an emulsion according to the present embodiment, it is possible to produce an emulsion in which droplets of an oil component having a small average particle diameter are dispersed using a small amount of a surfactant.

  This is because, in the method for producing an emulsion according to the present embodiment, the aqueous component before the merging in the merging step, the oily component before the merging in the merging step, and the merging of the aqueous component and the oily component in the merging step One or two or more of the above fluids are allowed to flow through pores having a pore size of 0.1 to 3 mm, so that the oil component and the aqueous component containing a specific nonionic surfactant are combined or after the combination. This is considered to be because the specific nonionic surfactant used for emulsification is efficiently supplied from the oily component to be emulsified to the oil-water interface due to the stirring effect of the turbulent flow. That is, in the method for producing an emulsion according to the present embodiment, the diffusion of the nonionic surfactant from the oily component into the aqueous component can be efficiently suppressed without contributing to the emulsification.

  The details will be described below.

  The method for producing an emulsion according to the present embodiment includes a merging step and a pore distribution step.

  In the merging step, the liquid aqueous component and the liquid oil component are merged.

  The aqueous component is typically water, but may be an aqueous solution in which a solute such as a salt is dissolved in water, or a mixed solution of water and a water-soluble organic solvent. The content of water in the aqueous component is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more, from the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant. It is even more preferably 95% by mass or more, even more preferably 98% by mass or more, and may be substantially 100% by mass. Examples of the water-soluble organic solvent include alcohols having 1 to 3 carbon atoms such as methanol and ethanol.

  The aqueous component may contain a surfactant. Examples of the surfactant include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. The content of the surfactant in the aqueous component is preferably 2% by mass or less, more preferably 1% by mass or less, and still more preferably 0.5% by mass, from the viewpoint of obtaining an emulsion of fine droplets with a small amount of the surfactant. % By mass or less, substantially 0% by mass or 0.1% by mass or more.

  The oil component contains an oil agent that is liquid at 20 ° C. (hereinafter also referred to as “liquid oil”) from the viewpoint of emulsification with a small amount of a surfactant.

  Examples of the liquid oil include liquid hydrocarbon oils, liquid ester oils, liquid dialkyl ethers, liquid fats and oils, liquid higher alcohols or fatty acids, liquid silicones, and liquid functional oils (eg, ceramide, organic UV absorbers, sphingolipids), and liquid fragrances. It is preferable that the liquid oil contains one or more selected from these groups. Liquid oil has one or more functional groups selected from the group consisting of ester groups, hydroxyl groups, ether groups, and carbonyl groups from the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant. It is preferable to include an oil agent.

  Examples of the liquid hydrocarbon oil include paraffin, squalene, and squalane.

  Examples of the liquid ester oil include liquid ethylene glycol difatty acid esters (fatty acids having a preferred carbon number of 8 to 22), fatty acid monoglycerides, fatty acid diglycerides, and fatty acid triglycerides. ) And the like.

  Examples of the liquid dialkyl ether include ethers having a saturated or unsaturated linear or branched alkyl group having 8 to 22 carbon atoms.

  Examples of the liquid fats and oils include vegetable oils such as soybean oil, coconut oil, palm kernel oil, linseed oil, cottonseed oil, rapeseed oil, kiri oil, and castor oil.

  As the liquid higher alcohol or higher fatty acid, a saturated or unsaturated linear or branched liquid alcohol (preferably having 8 to 22 carbon atoms); a saturated or unsaturated linear or branched chain such as oleic acid and caprylic acid (Fatty acids having a preferred carbon number of 8 to 22).

  Examples of liquid silicones include methylpolysiloxane, methylphenylsiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, methylhydrogenpolysiloxane, silicone resin, amino-modified silicone, and alkyl-modified silicone. Examples of the liquid functional oil include organic ultraviolet absorbers such as 2-ethylhexyl paramethoxycinnamate; and liquid sphingolipids such as 1- (2-hydroxyethylamino) -3-isostearyloxy-2-propanol. Is mentioned. Examples of the liquid fragrance include general ones conventionally used.

  It is preferable to use one or more selected from these as the liquid oil. Among these, from the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant, liquid ester oil and liquid higher alcohol are more preferably used, and liquid fatty acid glyceride is more preferable. The liquid oil may be a nonionic surfactant having an HLB of less than 7, preferably HLB of 5 or less. HLB can be determined by a method described later.

  Liquid oils may be either volatile or non-volatile.

  The viscosity of the liquid oil is preferably 0.1 mPa · s or more, more preferably 1 mPa · s or more, at the temperature of the oil component when the oil component and the aqueous component are merged, from the viewpoint of performing good liquid feeding. It is preferably at least 5 mPa · s, and from the viewpoint of reducing the particle size of the droplet, it is preferably at most 1,000 mPa · s, more preferably at most 500 mPa · s, even more preferably at most 300 mPa · s. Here, the viscosity of the liquid oil was measured using a Brookfield-type (B-type) rotational viscometer, using a rotor No. 3 is used as a standard (when the viscosity cannot be measured, the rotor is changed to No. 1, 2, or 4), and the measurement is performed under the conditions of a rotation speed of 30 r / min and a measurement time of 1 minute.

  The molecular weight of the liquid oil is preferably 40 or more, more preferably 100 or more, and still more preferably 150 or more, from the viewpoint of performing the liquid sending favorably. It is 2,000 or less, more preferably 1500 or less, and further preferably 1,000 or less.

  The melting point of the liquid oil is preferably 15 ° C. or lower, more preferably 10 ° C. or lower, still more preferably 5 ° C. or lower, and still more preferably, from the viewpoint of favorably combining the oil component and the aqueous component. Is 0 ° C. or less. In addition, the melting point of the liquid oil can be measured by a differential scanning calorimetry (DSC).

  The amount of the liquid oil dissolved in 100 g of water at 20 ° C. is preferably 10 g or less, more preferably 5 g or less, at the temperature of the oil component when the oil component and the aqueous component are combined from the viewpoint of good dispersion. It is more preferably at most 3 g, particularly preferably at most 1 g.

  The content of the liquid oil in the oil component is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 92% by mass or more, from the viewpoint of obtaining an emulsion of the liquid oil. From the viewpoint of obtaining an emulsion of fine droplets by including a nonionic surfactant in the component, preferably 99.99% by mass or less, more preferably 99.9% by mass or less, and still more preferably 99.5% by mass. Or less, still more preferably 99% by mass or less, particularly preferably 98% by mass or less.

  It is preferable that the oily component contains a nonionic surfactant having an HLB of 7 or more at 10% by mass or less, and that each component is uniformly dissolved. The dissolution of the nonionic surfactant in the oily component can be visually confirmed.

  Examples of the nonionic surfactant having an HLB of 7 or more include oxyethylene of polyhydric alcohol fatty acid esters such as polyoxyethylene hydrogenated castor oil, polyoxyethylene castor oil, polyoxyethylene sorbitan fatty acid ester, and polyoxyethylene sorbitol fatty acid ester. Polyhydric alcohol fatty acid esters such as sorbitan fatty acid esters and sucrose fatty acid esters; oxyalkylene adducts of higher alcohols such as polyoxyethylene alkyl ether and polyoxyethylene polyoxypropylene alkyl ether; polyethylene glycol fatty acid esters; polyglycerin Fatty acid esters; alkyl (poly) glucosides such as alkyl glucosides and alkyl polyglucosides; and fatty acid monoalkylolamides. As the nonionic surfactant having an HLB of 7 or more, it is preferable to use one or more selected from these.

  Of these, from the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant, an oxyethylene adduct of a polyhydric alcohol fatty acid ester, an oxyethylene adduct of a higher alcohol, a fatty acid ester of polyethylene glycol, an alkyl (poly) ) One or more selected from fatty acid esters of glucoside and polyglycerin are preferable, oxyethylene adducts of polyhydric alcohol fatty acid esters are more preferable, and hydrogenated castor oil having a polyoxyethylene group is more preferable.

  The polyhydric alcohol preferably has 3 to 6 carbon atoms, for example, glycerin, sorbitol, glucose and the like. The fatty acid preferably has 8 to 22 carbon atoms, more preferably 8 to 18 carbon atoms. The carbon number of the higher alcohol is preferably 8 to 22, more preferably 8 to 18.

  Examples of the oxyalkylene adduct of a higher alcohol such as polyoxyethylene alkyl ether and polyoxypropylene alkyl ether include those represented by the following formula (I).

R ¹ -O- (R ² O) _p -H (I)
(Wherein, R ¹ represents a linear or branched saturated or unsaturated hydrocarbon group having 8 to 22 carbon atoms, and R ² represents an ethylene group. P represents 1 to 12, preferably 1 to 6) Number means the average number of moles added.)
Examples of the fatty acid monoalkylolamide include those represented by the following (II).

R ³ CO—NH—R ⁴ OH (II)
(In the formula, R ³ represents a linear or branched saturated or unsaturated hydrocarbon group having 7 to 20 carbon atoms, and R ⁴ represents an ethylene group.)
As the nonionic surfactant having an HLB of 7 or more, it is preferable to use one or more selected from these.

  The HLB of the nonionic surfactant is 7 or more, but from the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant, preferably 8 or more, more preferably 9 or more, and still more preferably 10 or more. The above is even more preferably 12 or more, and from the viewpoint of emulsifying the oily component, it is preferably 20 or less, more preferably 18 or less, still more preferably 16 or less, and even more preferably 15 or less.

  The content of the nonionic surfactant having an HLB of 7 or more in the oil component is 10% by mass or less, but from the viewpoint of obtaining an emulsion with a small amount of surfactant, preferably 9% by mass or less, more preferably 8% by mass. % Or less, more preferably 6% by mass or less, and from the viewpoint of finely emulsifying the oily component, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 1% by mass or more. And still more preferably 2% by mass or more, and still more preferably 4% by mass or more.

  The oily component, besides the liquid oil and the nonionic surfactant having an HLB of 7 or more, keeps a liquid state at the time of merging, and a solid fat or the like as long as it does not hinder the production of an emulsion of fine droplets as described below. Can be contained by dissolving in a liquid oil.

  The HLB is determined based on a calculation formula described in “Techniques of emulsification and solubilization”, Kogaku Tosho Co., Ltd. (Showa 59-5-20), pages 8-12. More specifically, in the case of a polyhydric alcohol fatty acid ester, the formula: [HLB] = 20 (1-S / A) (where S represents the saponification value of the ester and A represents the acid value of the fatty acid) Required based on.

  In the case of an oxyethylene adduct of a polyhydric alcohol fatty acid ester, the formula: [HLB] = (E + P) / 5 (where E represents the oxyethylene content (% by mass), and P represents the polyhydric alcohol content (% by mass). ).

  In the case of an oxyethylene adduct of a higher alcohol, it is determined based on the formula: [HLB] = E / 5 (where E is the same as described above). Here, the acid value and the saponification value can be determined according to JIS K0070-1992.

  For other nonionic surfactants, the formula: [HLB] = 7 + 1.71 log (Mw / Mo) (where Mw is the molecular weight of the hydrophilic group of the surfactant, and Mo is the hydrophobicity of the surfactant) The molecular weight of the group, log, indicates the logarithm of the base 10).

When two types of surfactant A, HLB7 or more, and surfactant B, HLB7 or more, are used as nonionic surfactants, if each HLB is HLB _A and HLB _B , the nonionic surfactant HLB surfactants, each of mass fraction of (%) _W a, when a _{W B,} wherein: [HLB] _{= [(W a × HLB a} ) + (W B × HLB B)] ÷ (W obtained on the basis of the _A + _{W B).} When three or more surfactants are used in combination as the nonionic surfactant, the HLB of the nonionic surfactant obtained by mixing them can be determined in the same manner as described above.

  From the viewpoint of finely emulsifying the oily component with a small amount of a surfactant, the oily component preferably has self-emulsifiability with respect to the aqueous component. Here, the presence or absence of the self-emulsifying property can be determined as follows. First, 90 ml of the aqueous component and 10 ml of the oil component are weighed. Next, the oil component is introduced into the aqueous component at a rate of 10 ml / min using an injection needle (outer diameter: 1.58 mm, inner diameter: 0.25 mm). At this time, the tip of the injection needle is immersed in the aqueous component, and stirring is not performed. After the entire amount of the oily component was charged, the volume of the oily component in the aqueous component was measured by a laser scattering / diffraction method using a laser diffraction / scattering type particle size distribution analyzer (for example, device name: LA-910 manufactured by Horiba, Ltd.). The standard average dispersed particle size is measured. When the measured average dispersed particle size is smaller than the inner diameter of the injection needle is 0.25 mm, it is determined that "there is self-emulsifying property", and when it is larger, it is determined that "there is no self-emulsifying property".

  The viscosity of the oily component and the aqueous component is preferably from 0.1 mPa · s or more, more preferably at the temperature of each component when the oily component and the aqueous component are combined from the viewpoint of performing a good liquid sending. 1 mPa · s or more, more preferably 5 mPa · s or more, and from the viewpoint of reducing the size of emulsified droplets, preferably 1000 mPa · s or less, more preferably 500 mPa · s or less, and still more preferably 300 mPa · s. It is as follows. The viscosity of the oil component and the viscosity of the aqueous component may be the same or different. The method for measuring the viscosity of the oil component and the aqueous component is the same as the method for measuring the viscosity of the liquid oil described above.

  In the merging step, the flow rate of the aqueous components before merging is preferably 0.1 L / h or more, from the viewpoint of enhancing the effect of turbulence and obtaining an emulsion of fine droplets with a small amount of surfactant. It is preferably at least 1 L / h, and from the viewpoint of enhancing the mixing property after merging and obtaining an emulsion of fine droplets with a small amount of surfactant, preferably at most 300 L / h, more preferably at least 200 L / h. h or less, more preferably 100 L / h or less, even more preferably 30 L / h or less. The flow rate of the oily components before being combined is preferably 0.01 L / h or more, more preferably 0.1 L / h, from the viewpoint of enhancing the effect of turbulence and obtaining an emulsion of fine droplets with a small amount of surfactant. 1 L / h or more, and from the viewpoint of enhancing the mixing property after merging and obtaining an emulsion of fine droplets with a small amount of surfactant, preferably 150 L / h or less, more preferably 100 L / h or less. And more preferably 50 L / h or less, and still more preferably 2 L / h or less. From the viewpoint of emulsification with a small amount of a surfactant, the flow ratio of the aqueous component to the oil component before the merging (the flow rate of the aqueous component / the flow rate of the oil component) is preferably 1/1 or more, more preferably 2/1 or more. And more preferably 5/1 or more, and from the viewpoint of increasing the amount of oily components in the emulsion, preferably 200/1 or less, more preferably 100/1 or less, and still more preferably 50/1 or less. is there. The mixing mass ratio of the aqueous component and the oil component is preferably 1/1 or more, more preferably 2/1 or more, and still more preferably from the viewpoint of obtaining an O / W emulsion with a small amount of a surfactant. From the viewpoint of increasing the amount of oily components in the emulsion, it is preferably at most 200/1, more preferably at most 100/1, even more preferably at most 50/1.

  In the merging step, the temperature of the aqueous components before merging is preferably 5 ° C. or higher, more preferably 10 ° C. or higher, and preferably 95 ° C. or lower, more preferably 90 ° C. or lower, and still more preferably 50 ° C. or lower. It is. The temperature of the oily components before being combined is preferably 5 ° C. or higher, more preferably 10 ° C. or higher, and is preferably 95 ° C. or lower, more preferably 90 ° C. or lower, and further preferably 50 ° C. or lower. . The temperature of the aqueous component and the temperature of the oil component before being combined may be the same, and can be set arbitrarily.

  In the merging step, the manner of merging the aqueous component and the oily component is not particularly limited.

  As a mode (angle) of the collision when the aqueous component and the oil component are merged, for example, a mode in which both are collided by head-on collision, a mode in which one collides from a direction orthogonal to the other, and a mode in which one is the other A mode in which one collides obliquely from the rear and merges, a mode in which one collides with the other obliquely from the front and merges, and a mode in which one contacts along the other and merges.

  As a mode (number, etc.) of the merging method when the aqueous component and the oily component are merged, for example, a mode in which both collide in a plurality of directions to merge, and a mode in which one collides with the other in a plurality of directions. And a mode in which one collides from the entire circumference of the other to merge. In a mode in which both are collided and merged from a plurality of directions, respectively, it is preferable to collide preferably from two or more directions. Further, there is no particular upper limit, but from the viewpoint of productivity, collisions from four directions or less are performed. Preferably. In a mode in which one collides with the other from a plurality of directions to merge, it is preferable that one collides with the other preferably from two or more directions, and there is no particular upper limit, but from the viewpoint of productivity, one is formed in four directions. It is preferable to cause the other to collide from the following directions.

  Of these, as a mode of collision at the time of merging, a mode in which an oily component collides with an aqueous component from a direction orthogonal to or obliquely rearward is preferable. Are preferred to collide with each other.

  In the pore distribution step, one or two of the aqueous component before the merging in the merging step, the oil component before the merging in the merging step, and the fluid after the aqueous component and the oil component are merged in the merging step The above is circulated through the pores. Here, “before merging” means immediately before merging.

  Therefore, the first embodiment may be such that neither the aqueous component before merging nor the oil component before merging flows through the pores, and only the fluid after merging flows through the pores. The second embodiment may be such that the oil component before merging does not flow through the pores, and the aqueous component before merging and the fluid after merging flow through the pores. A third embodiment may be such that the oil component before the merger and the fluid after the merger respectively flow through the pores without flowing the aqueous component before the merger through the pores.

  A fourth embodiment may be such that the aqueous component before merging and the oil component before merging flow through the pores, respectively, and the fluid after merging does not flow through the pores. A fifth embodiment may be such that only the aqueous component before merging flows through the pores, and neither the oily component before merging nor the fluid after merging flows through the pores. A sixth embodiment may be such that only the oily component before merging flows through the pores, and neither the aqueous component before merging nor the fluid after merging flows through the pores.

  Further, a seventh mode may be adopted in which the aqueous component before merging, the oil component before merging, and the fluid after merging flow through the pores.

  Among these, the first to third and seventh aspects having a process of flowing the fluid after the aqueous component and the oil component have been combined in the combining step through the pores are preferable.

  From the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant, the cross-sectional shape of the pore is preferably circular, but semicircular, elliptical, semielliptical, square, rectangular, trapezoidal, The shape may be a non-circle such as a parallelogram, a star, or an irregular shape. The cross-sectional shape of the pores is preferably the same along the length direction.

  The direction in which the pores extend is preferably the same as the flow direction of the aqueous component and / or the flow direction of the oil component, from the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant.

  The pore diameter of the pores is 0.1 mm or more, preferably 0.2 mm or more, more preferably 0.3 mm or more from the viewpoint of obtaining high productivity. From the viewpoint of obtaining an emulsion of fine droplets by the generation of turbulence, the pore diameter of the fine pore is 3 mm or less, preferably 1.5 mm or less, more preferably 1 mm or less. Here, the pore diameter of the pore is the diameter when the cross section of the pore is circular, but the equivalent hydraulic diameter (4 × flow area / cross section) when the cross section of the pore is non-circular. Long).

  The length of the pores is preferably 0.05 mm or more, more preferably 0.1 mm or more, and still more preferably 0.3 mm or more, from the viewpoint of increasing the pressure loss and increasing the mixing property between the oil component and the aqueous component. From the viewpoint of instantaneously mixing the oily component and the aqueous component after the merging and producing an emulsion of fine droplets, the size is preferably 5 mm or less, more preferably 3 mm or less.

Flow passage area of the pores is preferably from the viewpoint of preventing to bring the fault to equipment caused excessive pressure loss 0.01 mm ² or more, more preferably 0.03 mm ² or more, and increasing the pressure loss from the viewpoint of enhancing the mixing of the oily and aqueous components Te, preferably 7 mm ² or less, more preferably 2 mm ² or less.

  The ratio of the length of the pores to the diameter of the pores (length / pore diameter) is preferably 0.15 or more, more preferably 0.2 or more, from the viewpoint of obtaining an emulsion of fine droplets by generating turbulence. It is preferably at least 0.5, more preferably at least 1, and from the same viewpoint, preferably at most 40, more preferably at most 20, still more preferably at most 10, and even more preferably at most 5.

  In the pore distribution step, as a method of flowing the fluid after the aqueous component and the oil component are merged in the confluence step to the pores, the aqueous component and the oil component are once merged in the liquid reservoir, and they are mixed. The fluid in the state may be allowed to flow through the pores, but from the viewpoint of emulsification with a small amount of surfactant, a junction of the aqueous component and the oil component is provided immediately before the pores, or within the pores. It is preferred to join.

  In the pore flow step, the flow rate when flowing the fluid after the aqueous component and the oil component have been combined in the merge step in the pores is from the viewpoint of increasing the pressure loss and producing an emulsion of fine droplets. It is preferably at least 0.1 L / h, more preferably at least 1.0 L / h, and preferably from 300 L / h or less, from the viewpoint of preventing an excessive pressure loss from causing a failure in the equipment. It is preferably at most 250 L / h, more preferably at most 100 L / h, even more preferably at most 50 L / h, even more preferably at most 20 L / h, even more preferably at most 10 L / h.

In the pore distribution step, it is preferable to distribute the aqueous component and the oil component through the pores under turbulent flow conditions. The Reynolds number at this time is preferably 1,000 or more, more preferably 2,000 or more, from the viewpoint of increasing the stirring efficiency of the oil phase component and the aqueous phase component after flowing through the pores, and from the same viewpoint, preferably It is 150,000 or less, more preferably 100,000 or less. Here, the Reynolds number is a value of the average flow velocity u (m / s) in the pore, the pore diameter d (m), the viscosity μ (Pa · s) of the fluid, and the density ρ (kg / m ³ ) of the fluid. Can be obtained by a general equation for calculating the Reynolds number of a pipe flow (Reynolds number Re = duρ / μ).

  In the pore distribution step, it is preferable that the fluid after the aqueous component and the oil component have been combined in the confluence step be circulated through the pores and flow out to the flow channel enlarging portion. As a result, a turbulent flow is generated by both components, so that the droplet can be miniaturized.

  In particular, when the fluid after the aqueous component and the oil component are combined is allowed to flow through pores having a pore diameter of 0.1 to 3 mm, both components are agitated by turbulent flow in the flow channel expansion region after the pores flow. As a result, the nonionic surfactant is more efficiently supplied from the oil component to the oil-water interface. As a result, an emulsion of fine droplets can be obtained with a smaller amount of the nonionic surfactant.

  From the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant, the cross-sectional shape of the flow channel of the flow channel expansion portion is preferably circular, but semicircular, elliptical, semielliptical, square , A rectangle, a trapezoid, a parallelogram, a star, an irregular shape and the like. The cross-sectional shape of the enlarged channel portion is preferably the same shape along the length direction, but may include different shapes along the length direction.

  From the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant, the flow channel expanding portion is preferably formed so as to expand in a cone shape from the pore to the portion having the maximum flow channel diameter. This cone expansion angle is preferably 90 ° or more, more preferably 100 ° or more, and is preferably 180 ° or less, more preferably 170 ° or less, and even more preferably 150 ° or less.

  From the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant, the maximum flow path diameter of the flow path enlarged portion is preferably 3 times or more, more preferably 5 times or more of the pore diameter of the pores, Preferably it is 50 times or less, more preferably 40 times or less, still more preferably 20 times or less. Here, the maximum flow path diameter of the enlarged flow path section is a diameter when the cross section of the flow path is circular, but is an equivalent hydraulic diameter when the cross section of the flow path is non-circular.

  The emulsion produced by the method of the present embodiment is one in which droplets of an oil component having an average particle size of 1/100 or less of the pore diameter are dispersed in the aqueous component. Here, in the case of the first embodiment, the average particle diameter of the droplet of the oil component is 1/100 or less of the pore size of the pore through which the fluid after the aqueous component and the oil component converge. In the case of the second aspect, the average particle diameter of the oil component droplets is 1/100 or less of the pore size of the pores through which the aqueous component flows, and the fluid after the merge of the aqueous component and the oil component flows. 1/100 or less of the pore diameter of the pores to be formed. In the case of the third aspect, the average particle size of the oil component droplets is 1/100 or less of the pore size of the pores through which the oil component flows, and the fluid after the aqueous component and the oil component converge flows. 1/100 or less of the pore diameter of the pores to be formed.

  In the case of the fourth aspect, the average particle size of the oil component droplet is 1/100 or less of the pore size of the pore through which the aqueous component flows, and 1/100 of the pore size of the pore through which the oil component flows. Also below. In the case of the fifth aspect, the average particle diameter of the oil component droplet is 1/100 or less of the pore diameter of the pore through which the aqueous component flows. In the case of the sixth embodiment, the average particle size of the oil component droplets is 1/100 or less of the pore size of the pores through which the oil component flows.

  In the case of the seventh embodiment, the average particle size of the oil component droplet is 1/100 or less of the pore size of the pore through which the aqueous component flows, and 1/100 of the pore size of the pore through which the oil component flows. Or less than 1/100 of the pore diameter of the pores through which the fluid after the aqueous component and the oil component have joined.

  In any of the first to seventh embodiments, as described above, the average particle size of the droplets of the oily component in the emulsion to be produced is, from the viewpoint of obtaining an emulsion of fine droplets, fine pores. Is 1/100 or less, preferably 1/200 or less, more preferably 1/300 or less, and the lower limit is preferably 1 / 10,000 or more, more preferably 1/3000, from the viewpoint of productivity. Above, more preferably 1/1000 or more.

  Specifically, the average particle diameter of the droplets of the oily component in the produced emulsion is preferably 1.5 μm or less, more preferably 1 μm or less, and still more preferably from the viewpoint of obtaining an emulsion of fine droplets. Is 0.5 μm or less, and the lower limit is preferably 0.05 μm or more, more preferably 0.1 μm or more. Here, the average particle size of the droplets of the oily component in the emulsion is measured by a laser scattering / diffraction method using a laser diffraction / scattering type particle size distribution measuring device (for example, device name: LA-910 manufactured by Horiba, Ltd.). Is the median diameter of the oily component measured by

  The content of the liquid oil in the produced emulsion is preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 4% by mass or more, from the viewpoint of containing the liquid oil in the emulsion. In addition, from the viewpoint of emulsifying with a small amount of surfactant and reducing the average particle diameter of the oily component droplet, it is preferably 50% by mass or less, more preferably 30% by mass or less, and still more preferably 10% by mass or less. It is more preferably at most 8% by mass.

  The content of the nonionic surfactant in the produced emulsion is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, from the viewpoint of reducing the average particle diameter of the oil component droplets. And more preferably 0.1% by mass or more, and from the viewpoint of emulsification with a small amount of surfactant, preferably 2.0% by mass or less, more preferably 1.0% by mass or less, still more preferably Is 0.5% by mass or less, more preferably 0.3% by mass or less. From the viewpoint of reducing the average particle size of the droplets of the oily component, the content of all surfactants in the produced emulsion is preferably 0.01% by mass or more, more preferably 0.05% by mass or more. Yes, more preferably 0.1% by mass or more, and from the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant, preferably 2.0% by mass or less, more preferably 1.0% by mass. %, More preferably 0.5% by mass or less.

  The mass ratio of the content of the nonionic surfactant to the content of the liquid oil in the manufactured emulsion (nonionic surfactant / liquid oil) is determined from the viewpoint of reducing the average particle diameter of the oil component droplets. It is preferably at least 0.01, more preferably at least 0.02, even more preferably at least 0.03, and preferably 0.15 from the viewpoint of obtaining an emulsion of fine droplets with a small amount of surfactant. Or less, more preferably 0.1 or less, still more preferably 0.06 or less.

  The content of water in the produced emulsion is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more, from the viewpoint of containing the liquid oil in the emulsion. In addition, from the viewpoint of including liquid oil in the emulsion, the content is preferably 99% by mass or less, more preferably 97% by mass or less.

  In the emulsification operation of the aqueous component and the oil component in the method for producing an emulsion according to the present embodiment, the segregation index (Segregation index (Xs)) determined by the method described below reduces the average particle diameter of the oil component droplets. From the viewpoint of performing, it is preferable to perform under the condition of 0.1 or less, more preferably under the condition of 0.08 or less, more preferably under the condition of 0.06 or less, and 0.04 or less. It is more preferably performed under the condition of 0.02 or less, more preferably under the condition of 0.01 or less, and more preferably under the condition of 0.008 or less. , 0.005 or less, more preferably 0.004 or less. There is no particular lower limit, but 0.0001 or more is sufficient, and may be 0.001 or more. Here, the segregation index (Xs) indicates the effect of mixing and stirring the oily component and the aqueous component in the method for producing an emulsion according to the present embodiment, and a smaller value indicates a higher mixing property. It is an index generally used for evaluating the mixing performance of mixers for academic purposes, and can be derived from the following equation using Villermaux / Dushman reaction. The details of this reaction system are described in P. Guichardon and L. Falk, Chemical Engineering Science 55 (2000) 4233-4243.

  Specifically, first, 0.171 N sulfuric acid and a borate buffer are prepared as two aqueous solutions that react by mixing. The composition of the borate buffer is 0.045 mol / L of boric acid, 0.045 mol / L of sodium hydroxide, 0.00313 mol / L of potassium iodate, and 0.0156 mol / L of potassium iodide. Then, when the two liquids are mixed, the following neutralization reaction (I) and oxidation-reduction reaction (II) in which iodine is generated proceed simultaneously. The mixing of the two liquids is performed under the condition that the alkali after mixing is excessive.

  According to the above-described method for producing an emulsion according to the present embodiment, a liquid containing a liquid aqueous component and a fat or oil that is a liquid at 20 ° C. and containing a nonionic surfactant having an HLB of 7 or more and 10% by mass or less. By combining one or two or more of the aqueous component before merging, the oily component before merging, and the fluid after merging through predetermined pores, thereby forming a small amount of a surfactant. Using the above, an emulsion in which droplets of an oil component having a small average particle size are dispersed in an aqueous component can be produced.

  FIG. 1 shows an example of an emulsion production system A that can be used in the method for producing an emulsion according to the present embodiment.

  The emulsion production system A includes the micromixer 100 having the first configuration and an auxiliary unit such as a fluid supply system.

  2 and 3 show a micromixer 100 in a first configuration. In the micromixer 100 having the first configuration, the first aspect, that is, neither the aqueous component before the merging nor the oily component before the merging flows through the pores, and only the fluid after the merging passes through the pores. To produce an emulsion.

  The micro-mixer 100 of the first configuration includes a fluid flow channel 110, a fluid merging / contracting portion 120 provided continuously downstream thereof, and a fluid outlet portion 130 continuously provided downstream thereof. And

  The fluid flow path section 110 has a small diameter pipe 111 and a large diameter pipe 112. The large-diameter tube 112 houses the small-diameter tubes 111, which are arranged in a common longitudinal direction and coaxially. Thus, in the fluid flow path section 110, a first flow path 111a is formed inside the small diameter pipe 111, and a second flow path 112a is formed inside the large diameter pipe 112 and outside the small diameter pipe 111. The first flow path 111a in the small-diameter pipe 111 communicates with the aqueous component supply unit 101 provided at one end of the apparatus, and the second flow path 112a in the large-diameter pipe 112 is provided on the side of the apparatus. It communicates with the oily component supply unit 102.

  The outer shape of the small-diameter tube 111 and the cross-sectional shape of the hole are not particularly limited, and are, for example, circular, semi-circular, elliptical, semi-elliptical, square, rectangular, trapezoidal, parallelogram, star, and irregular. And so on. The cross-sectional shape of the hole of the large-diameter tube 112 is also not particularly limited, and may be, for example, circular, semi-circular, elliptical, semi-elliptical, square, rectangular, trapezoidal, parallelogram, The shape may be a star, an irregular shape, or the like. However, it is preferable that both the outer shape and the hole of the small diameter tube 111 and the cross section of the hole of the large diameter tube 12 are circular. It is preferable that the small-diameter pipe 111 and the large-diameter pipe 112 are provided so that the cross-sectional shapes thereof are symmetric and coaxial. Therefore, as shown in FIG. 3, the small-diameter pipe 111 and the large-diameter pipe 112 are configured such that the cross section of the first flow path 111a is circular and the cross section of the second flow path 112a is a donut shape. It is preferable that the configuration is provided.

  Both the outer shape and the cross-sectional shape of the hole of the small-diameter tube 111 are preferably the same along the length direction except for a tube end portion 111b described later. The cross-sectional shape of the hole of the large-diameter tube 112 is preferably the same along the length except for a portion corresponding to the tube end portion 111b of the small-diameter tube 111.

If any of the cross-sectional shape of the outer shape and the hole of the small diameter tube 111 is also circular, the outer diameter _{D 1} is preferably 1.6mm or more, more preferably 3mm or more, preferably 25mm or less, more preferably Is 15 mm or less. The inner diameter D ₂ of the small diameter pipe 111, that is, the flow path diameter of the first flow path 111a is preferably 0.8 mm or more, more preferably 2 mm or more, and is preferably 20 mm or less, more preferably 10 mm or less. If the cross sectional shape of the hole of the large-diameter tube 112 is circular, the inner diameter _{D 3} is preferably 1.8mm or more, more preferably 4mm or more, and preferably less than 50mm, more preferably 20mm or less is there. The gap Δ of the second flow path 112a between the small diameter pipe 111 and the large diameter pipe 112 is preferably 0.1 mm or more, more preferably 0.3 mm or more, and preferably 12.5 mm or less. Preferably it is 6 mm or less.

  As shown in FIG. 2, the pipe end portion 111b on the downstream side of the small-diameter pipe 111 preferably has a tapered outer peripheral portion, and a cross section in the thickness direction is sharp on the inner peripheral side. More preferably, it is formed in a shape.

  The gap δ, which is a part of the second flow path 112a formed between the inner wall of the large diameter pipe 112 and the pipe end portion 111b of the small diameter pipe 111, is preferably uniform in the fluid flow direction. The gap δ is preferably 0.02 mm or more, more preferably 0.05 mm or more, further preferably 0.1 mm or more, particularly preferably 0.3 mm or more, and preferably 12.5 mm or less, more preferably 6 mm or less.

  In the fluid converging / diverging section 120, a fluid converging area 121 is formed in front of the small-diameter pipe 111 at the pipe end, and a pore 122 is perforated continuously from the fluid converging area 121. In the fluid junction area 121, the aqueous component flowing through the first flow path 111a and the oily component flowing through the second flow path 112a merge. The components are distributed.

The fluid junction area 121 is not particularly limited, but is preferably formed in a tapered cone shape converging toward the pore 122 as shown in FIG. The cone angle of convergence theta ₁ is preferably 90 ° or more, more or preferably 100 ° or more, preferably 180 ° or less, more preferably 170 ° or less. Cone convergent angle theta ₁ is preferably the same as the cone larger angle theta ₂ of the flow channel expanding section 131 to be described later. The distance L from the end of the small diameter pipe 111 of the fluid junction area 121, that is, the distance from the end of the fluid flow passage 110 to the pore 122 is preferably 0.02 mm or more, more preferably 0.2 mm or more. It is preferably at most 20 mm, more preferably at most 3 mm, even more preferably at most 1 mm.

  The cross-sectional shape, the extending direction, the hole diameter d, the length 1, the channel area s, and the ratio of the length 1 to the hole diameter d (length 1 / hole diameter d) of the pore 122 are as described above.

  In the fluid outflow portion 130, a flow channel expanding portion 131 is formed in front of the pore 122. The fluid flowing through the fine holes 122 flows out to the flow channel expanding portion 131. In addition, the flow path expanding section 131 communicates with the emulsion collecting section 103 provided at the other end of the apparatus.

The cross-sectional shape and shape of the flow path of the fluid outflow section 130, the cone expansion angle θ ₂ , and the maximum flow path diameter D ₄ of the flow path expansion section 131 are as described above.

  The micromixer 100 may be composed of a plurality of members each formed of metal, ceramics, resin, or the like, and the fluid flow path unit 110, the fluid converging / contracting unit 120, and The fluid outlet 130 may be configured.

  Note that the micromixer 100 of the first configuration has a configuration in which one small-diameter pipe 111 is accommodated in the large-diameter pipe 112, but is not particularly limited thereto. ), A configuration in which a plurality of small-diameter pipes 111 are accommodated in a large-diameter pipe 112 may be employed.

  In this micromixer 100, an aqueous component supply pipe 42a extending from an aqueous component storage tank 41a is connected to an aqueous component supply unit 101 communicating with a first flow path 111a. A first pump 43a for flowing the aqueous component, a first flow meter 44a for detecting the flow rate of the aqueous component, and a first filter 45a for removing impurities of the aqueous component are sequentially provided in the aqueous component supply pipe 42a from the upstream side. A first pressure gauge 46a for detecting the pressure of the aqueous component is attached to a portion between the first flow meter 44a and the first filter 45a. Each of the first pump 43a, the first flow meter 44a, and the first pressure gauge 46a is electrically connected to the flow controller 47.

  An oil component supply pipe 42b extending from the oil component storage tank 41b is connected to the oil component supply unit 102 communicating with the second flow path 112a. A second pump 43b for flowing the oily component, a second flowmeter 44b for detecting the flow rate of the oily component, and a second filter 45b for removing impurities of the oily component are sequentially provided in the oily component supply pipe 42b from the upstream side. The second pressure gauge 46b for detecting the pressure of the oil component is attached to a portion between the second flow meter 44b and the second filter 45b. Each of the second pump 43b, the second flow meter 44b, and the second pressure gauge 46b is electrically connected to the flow controller 47.

  The flow rate controller 47 is configured to be capable of inputting the set flow rate and the set pressure of the aqueous component, and incorporates an arithmetic element, and sets the flow rate information of the aqueous component, the flow rate information detected by the first flow meter 44a, and The operation of the first pump 43a is controlled based on the pressure information detected by the first pressure gauge 46a. Similarly, the flow controller 47 is also configured to be able to input a set flow rate and a set pressure of the oily component, and set flow rate information of the oily component, flow rate information detected by the second flow meter 44b, and the second pressure gauge 46b. The operation of the second pump 43b is controlled based on the pressure information detected in the step (1).

  An emulsion collection pipe 48 extends from the emulsion collection section 103 communicating with the flow path expanding section 131 and is connected to an emulsion collection tank 49.

  Next, the operation of the emulsion production system A will be described.

  When the emulsion production system A operates, the first pump 43a causes the aqueous component to be a continuous phase to pass through the first flow meter 44a and the first filter 45a sequentially from the aqueous component storage tank 41a via the aqueous component supply pipe 42a. The fluid is continuously supplied to the first flow path 111a of the small diameter pipe 111 of the fluid flow path section 110. The first flow meter 44 a sends the detected flow rate information of the aqueous phase to the flow rate controller 47. Further, the first pressure gauge 46a sends the detected pressure information of the first pressure gauge 46a to the flow rate controller 47.

  The second pump 43b causes the oil component to be the dispersed phase to pass through the second flow meter 44b and the second filter 45b from the oil component storage tank 41b via the oil component supply pipe 42b in order, and the large diameter of the fluid flow path 110 It is continuously supplied to the second flow path 112a between the pipe 112 and the small diameter pipe 111. The second flow meter 44b sends the detected oil phase flow rate information to the flow rate controller 47. Further, the second pressure gauge 46 b sends the detected pressure information of the second pressure gauge 46 b to the flow rate controller 47.

  The flow controller 47 sets the flow rate of the aqueous component based on the set flow rate information and the set pressure information of the aqueous component, and the flow rate information detected by the first flow meter 44a and the pressure information detected by the first pressure gauge 46a. The operation of the first pump 43a is controlled such that the set pressure is maintained. At the same time, the flow controller 47 sets the oil component based on the set flow information and the set pressure information of the oil component, the flow information detected by the second flow meter 44b, and the pressure information detected by the second pressure meter 46b. The operation of the second pump 43b is controlled such that the set flow rate and the set pressure are maintained.

  Then, in the micromixer 100, in the fluid flow path portion 110, the aqueous component flows through the first flow path 111a, and the oily component flows through the second flow path 112a. At this time, the pressure of the aqueous component is, for example, 0.01 to 5 MPa. The pressure of the oil component is, for example, 0.01 to 5 MPa. The flow rate of the aqueous component is set to, for example, 0.05 to 2 m / s by the flow rate setting and the pressure setting of the aqueous component, and the flow rate of the oil component is set to, for example, 0.05 to 2 m / s by the flow rate setting and the pressure setting of the oil component. 2 m / s.

  In the fluid converging / diverging section 120, the aqueous component and the oil component flowing out of the fluid channel section 110 merge with the aqueous component in the fluid converging region 121 in such a manner that the oil component collides obliquely from behind and from the entire circumference thereof. I do. At this time, in the fluid converging / diverging section 120, the flow rate of the fluid including the aqueous component and the oil component is, for example, 0.05 to 2 m / s. This flow rate can be controlled by the flow rate setting and pressure setting of the aqueous component and the oil component, respectively.

  The aqueous component and the oil component that have joined in the fluid junction area 121 are mixed in the process of flowing through the pores 122. At this time, the flow conditions of the aqueous component and the oil component that have joined in the fluid junction area 121 can be controlled by setting the flow rate and pressure of the aqueous component and the oil component, respectively.

  In the fluid outflow portion 130, a fluid containing an aqueous component and an oil component flowing through the pores 122 flows out of the flow channel expanding portion 131, and convective mixing between the aqueous component and the oil component causes the droplets of the oil component to drop. An emulsion having an average particle size of 1/10 or less of the pore size of the pores 122 is produced.

  From the emulsion recovery section 103 communicating with the flow path expanding section 131, the manufactured emulsion is recovered in the emulsion recovery tank 49 via the emulsion recovery pipe 48. At this time, the pressure loss before and after the micromixer 100 is preferably 0.01 MPa or more, more preferably 0.1 MPa or more, and is preferably 5 MPa or less, more preferably 3.0 MPa or less. This pressure loss can be controlled by setting the flow rate and pressure of the aqueous component and the oil component, respectively.

  FIG. 5 shows a micromixer 200 having a second configuration. In the micromixer 200 having the second configuration, the emulsion is manufactured in the seventh mode, that is, the mode in which the aqueous component before merging, the oil component before merging, and the fluid after merging flow through the pores, respectively. .

  The micro-mixer 200 of the second configuration includes a straight tube portion 210 having one aqueous tube end as an aqueous component supply portion 201 and the other tube end as an oily component supply portion 202, and a central portion of the straight tube portion 210. It is constituted by a T-shaped tube which is branched and extends in the orthogonal direction, and has a branch pipe portion 220 having a pipe end serving as the emulsion recovery section 203. The micromixer 200 having the second configuration using the T-shaped tube has a simple device configuration, and maintenance by disassembly and cleaning is easy.

  In the straight pipe portion 210, the flow path at the center is narrowed, and the aqueous component supply section 201 side is the first flow path 211a, and the oil component supply section 202 side is the second flow path 212a. Each is configured. Therefore, the aqueous component supply tube 42a is connected to the aqueous component supply unit 201, and the oil component supply tube 42b is connected to the oil component supply unit 202.

  The branch pipe portion 220 has a fine hole 222 extending along the pipe axis and communicating with the inside of the straight pipe portion 210. The center of the straight pipe portion 210, that is, the inside of the branch portion to the branch pipe portion 220 is formed as a fluid junction area 221 that is continuous with the pores 222. Each of the first flow path 211a and the second flow path 212a preferably has a flow path cross-sectional area, that is, a hole area that is the same or similar to that of the pores 222, and also allows a pressure loss to be suppressed to a small value. It is preferable that the length of the flow path, that is, the length of the hole is the same as or similar to that of the fine hole 222. The branch pipe portion 220 is provided with a flow channel expanding portion 231 in which the flow channel cross-sectional area is expanded continuously from the fine holes 222. In addition, the emulsion recovery pipe 48 is connected to the emulsion recovery section 203 of the branch pipe section 220.

  The micromixer 200 of the second configuration causes the first liquid of the aqueous component and the second liquid of the oily component to collide with each other by head-on collision, and each of the first liquid and the second liquid toward the fluid merging area 221 of the first liquid and the second liquid. The flow direction and the direction in which the pores 222 extend are different from each other.

  Note that the micromixer 200 of the second configuration shown in FIG. 5 has a configuration in which the flow path in the central portion of the straight tube portion 210 is narrow, but is not particularly limited to this, and as shown in FIG. In addition, there may be a configuration in which there is no portion where the flow path is narrow, and a uniform flow path is provided from the aqueous component supply unit 201 to the oil component supply unit 202. In the micromixer 200 having the second configuration of the modified example shown in FIG. 6, the first aspect, that is, neither the aqueous component before merging nor the oily component before merging flows through the pores, An emulsion is produced by a mode in which only the subsequent fluid flows through the pores.

  Further, the micromixer 200 of the second configuration shown in FIG. 5 has a configuration in which the fine holes 222 are formed in the branch pipe portion 220, but the present invention is not particularly limited to this, and the micromixer 200 is continuously connected to the branch pipe portion. A configuration in which members having fine holes are separately connected may be used.

  FIGS. 7A to 7C show a micromixer 300 having a third configuration.

  The micromixer 300 of the third configuration is provided continuously with a fluid flow path portion 310 provided on a pipe route and a fluid merging / reducing portion 320 continuously provided on a liquid outflow side thereof and on a liquid outflow side thereof. Fluid outlet 330 provided.

  The fluid passage 310 has a small-diameter pipe 311 and a large-diameter pipe 312. The large-diameter tube 312 houses the small-diameter tubes 311, which have a common length and are coaxially arranged. Thus, in the fluid flow path portion 310, a first flow path 311a is formed inside the small diameter pipe 311, and a second flow path 312a is formed inside the large diameter pipe 312 and outside the small diameter pipe 311. The end of the small-diameter tube 311 is configured as an aqueous component supply unit (not shown), and the end of the large-diameter tube 312 exposed to the outside of the fluid flow path unit 310 is configured as an oil component supply unit (not illustrated). ing. Therefore, the aqueous component supply pipe 42a is connected to the aqueous component supply section, and the oily component supply pipe 42b is connected to the oily component supply section. Such a micromixer 300 having the fluid flow path portion 310 having a double pipe structure has a simple device configuration and easy maintenance by disassembly and cleaning.

  The fluid converging / diverging section 320 forms an internal region continuously with the liquid outflow end of the fluid channel section 310. This internal region is configured as a fluid junction area 321 where the first liquid and the second liquid flowing out of the fluid flow path 310 come into contact. In the fluid converging / diverging section 320, pores 322 provided continuously with the fluid converging area 321 are perforated. The pore 322 is formed so as to extend in the same direction as the direction in which the first flow path 311a and the second flow path 312a extend.

  The fluid outflow portion 330 is constituted by a cylindrical emulsion collection portion 303 provided continuously with the pores 322. The emulsified matter recovery section 303 is provided with a flow path expanding section 331 in which the flow path cross-sectional area is expanded continuously from the pores 322. In addition, the emulsion collection tube 48 is connected to the emulsion collection unit 303.

  In the micromixer 300 of the third configuration, the respective flow directions of the first liquid and the second liquid toward the fluid junction area 221 and the direction in which the pores 322 extend are all the same.

  By the way, the first liquid and the second liquid that have flowed out of the fluid flow path portion 310 and have come into contact with each other in the fluid junction area 321 are finally mixed by the pores 322. At this time, in order to obtain higher-speed mixing performance, it is preferable that the mixed state in the fluid junction region 321 is one in which minute segments of each liquid are formed. Therefore, it is preferable that the number of the first flow passages 311a is larger, and the number of the small diameter pipes 311 is plural as shown in FIGS. In such a case, higher-speed mixing characteristics can be obtained. When the number of the flow paths 311a and 311b is three or more, a third liquid different from the first liquid and the second liquid can be circulated through one of the flow paths 311a and 311b.

  In the micromixer 300 having the third configuration, the first liquid of the oil component may be passed through the first flow path 311a, and the second liquid of the aqueous component may be passed through the second flow path 312a. it can.

  With respect to the above-described embodiment, the following method for producing an emulsion is further disclosed.

<1> Merges a liquid aqueous component with a liquid oil component containing an oil agent that is liquid at 20 ° C. (also referred to as liquid oil) and containing 10% by mass or less of a nonionic surfactant having an HLB of 7 or more. Converging step,
One or two of the aqueous component before merging in the merging step, the oily component before merging in the merging step, and the fluid after merging the aqueous component and the oily component in the merging step One or more pores having a pore diameter of 0.1 to 3 mm, and
A method for producing an emulsion in which the oil component having an average particle size of emulsified droplets of 1/100 or less of the pore size of the pores is dispersed in the aqueous component.

  <2> the emulsified product according to <1>, wherein the pore distribution step includes a step of distributing the fluid after the aqueous component and the oil component are combined at least in the confluence step, through the pores. Production method.

  <3> The nonionic surfactant has an HLB of preferably 8 or more, more preferably 9 or more, more preferably 10 or more, more preferably 12 or more, and preferably 20 or less, more preferably 18 or more. The method for producing an emulsion according to <1> or <2>, wherein the number is further preferably 16 or less, more preferably 15 or less.

  <4> In the oily component of the liquid, the content of the nonionic surfactant is preferably 9% by mass or less, more preferably 8% by mass or less, further more preferably 6% by mass or less, and more preferably Is at least 0.01% by mass, more preferably at least 0.1% by mass, still more preferably at least 1% by mass, still more preferably at least 2% by mass, even more preferably at least 4% by mass. 3> The method for producing an emulsion according to any one of the above.

  <5> The pore diameter of the pores is preferably 0.2 mm or more, more preferably 0.3 mm or more, and preferably 3 mm or less, more preferably 1.5 mm or less, and still more preferably 1 mm or less. The method for producing an emulsion according to any one of <1> to <4>.

  <6> The average particle size of the emulsified droplet is preferably 1/200 or less, more preferably 1/300 or less, and preferably 1/10000 or more, more preferably 1/200 or less of the pore size of the pore. / 3000 or more, still more preferably 1/1000 or more, the method for producing an emulsion according to any one of <1> to <5>.

  <7> The mass ratio of the content of the nonionic surfactant to the content of the liquid oil in the produced emulsion (nonionic surfactant / liquid oil) is preferably 0.01 or more, more preferably 0.02 or more, more preferably 0.03 or more, and preferably 0.15 or less, more preferably 0.1 or less, and still more preferably 0.06 or less. A method for producing an emulsified product as described in

  <8> In the pore flow step, the fluid after the aqueous component and the oil component are combined in the combining step is preferably 0.1 L / h or more, more preferably 1.0 L / h or more. Further, it is preferably 300 L / h or less, more preferably 250 L / h or less, further preferably 100 L / h or less, more preferably 50 L / h or less, still more preferably 20 L / h or less, and still more preferably 10 L / h or less. The method for producing an emulsion according to any one of <1> to <7>, wherein the emulsion is passed through the pores at a flow rate of:

  <9> In the pore flowing step, the fluid after the aqueous component and the oil component are combined in the joining step is passed through the pore, and the maximum flow path diameter is preferably the pore diameter of the pore. Is 3 times or more, more preferably 5 times or more, and more preferably 50 times or less, more preferably 40 times or less, and still more preferably 20 times or less. <8> The method for producing an emulsion according to any one of the above.

  <10> In the merging step, the flow rate ratio of the aqueous component to the oily component before merging (the flow rate of the aqueous component / the flow rate of the oily component) is preferably 1/1 or more, more preferably 2/1 or more, The emulsion according to any one of <1> to <9>, further preferably 5/1 or more, preferably 200/1 or less, more preferably 100/1 or less, and still more preferably 50/1 or less. Manufacturing method.

  <11> The method for producing an emulsion according to any one of <1> to <10>, wherein, in the merging step, the oily component is merged with the aqueous component from all around.

  <12> The average particle size of the emulsified droplets of the oily component in the produced emulsion is preferably 1.5 μm or less, more preferably 1 μm or less, further preferably 0.5 μm or less, and preferably 0.1 μm or less. The method for producing an emulsion according to any one of <1> to <11>, wherein the emulsion has a thickness of 05 µm or more, more preferably 0.1 µm or more.

  <13> The method for producing an emulsion according to any one of <1> to <12>, wherein the oil component has a self-emulsifying property with respect to the aqueous component.

  <14> The emulsification operation of the aqueous component and the oil component is performed by a segregation index (Xs) of preferably 0.1 or less, more preferably 0.08 or less, more preferably 0.06 or less, and more preferably 0 or less. 0.04 or less, more preferably 0.02 or less, more preferably 0.01 or less, more preferably 0.008 or less, more preferably 0.005 or less, more preferably 0.004 or less, and preferably 0.04 or less. The method for producing an emulsion according to any one of <1> to <13>, wherein the method is carried out under a condition of at least 0001, more preferably at least 0.001.

  <15> The method for producing an emulsion according to any one of <1> to <14>, wherein a direction in which the pores extend is the same as a flow direction of the aqueous component and / or a flow direction of the oily component.

  <16> The length of the pores is preferably 0.05 mm or more, more preferably 0.1 mm or more, still more preferably 0.3 mm or more, and preferably 5 mm or less, more preferably 3 mm or less. , <1> to <15>.

<17> the flow passage area of the pores, preferably 0.01 mm ² or more, more preferably 0.03 mm ² or more, preferably 7 mm ² or less, more preferably 2 mm ² or less, <1 > The method for producing an emulsion according to any one of <16>.

  <18> The ratio of the length of the pores to the pore diameter (length / pore diameter) is preferably 0.15 or more, more preferably 0.2 or more, still more preferably 0.5 or more, and still more preferably 1 or more. And the production method of the emulsion according to any one of <1> to <17>, which is preferably 40 or less, more preferably 20 or less, still more preferably 10 or less, and still more preferably 5 or less.

  <19> The method for producing an emulsion according to any one of <1> to <18>, wherein in the pore distribution step, the aqueous component and the oil component are distributed through the pores under turbulent conditions.

  <20> The method for producing an emulsion according to <9>, wherein the flow channel expanding portion is formed so as to expand in a cone shape from the pore to a portion having a maximum flow channel diameter.

  <21> The cone expansion angle of the flow channel expansion portion is preferably 90 ° or more, more preferably 120 ° or more, and preferably 180 ° or less, more preferably 170 ° or less, and still more preferably 150 °. The method for producing an emulsion according to <20> below.

  <22> supplying the aqueous component and the oil component to a micromixer, performing the merging step and the pore distribution step in the micromixer, and collecting an emulsion from the micromixer; The pressure loss before and after the micromixer is preferably 0.01 MPa or more, more preferably 0.1 MPa or more, and preferably 5 MPa or less, more preferably 3.0 MPa or less. <1> to <21> The method for producing an emulsion according to any one of the above.

  <23> The content of the liquid oil in the oil component is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 92% by mass or more, and preferably 99.99% by mass or less. Any of <1> to <22>, preferably 99.9% by mass or less, more preferably 99.5% by mass or less, still more preferably 99% by mass or less, particularly preferably 98% by mass or less. A method for producing an emulsion.

  <24> The liquid oil preferably contains an oil agent having one or more functional groups selected from the group consisting of an ester group, a hydroxyl group, an ether group, and a carbonyl group, and is preferably a liquid hydrocarbon. Oils, liquid ester oils, liquid dialkyl ethers, liquid fats and oils, liquid higher alcohols, liquid higher fatty acids, liquid silicones, liquid functional oils (eg ceramides, organic UV absorbers, sphingolipids), and <1> to <1 including one or more selected from the group consisting of liquid fragrances, more preferably including liquid ester oil and / or liquid higher alcohol, and still more preferably including liquid fatty acid glyceride. 23> The method for producing an emulsion according to any one of the above.

  <25> The nonionic surfactant is preferably an oxyethylene adduct of a polyhydric alcohol fatty acid ester, an oxyethylene adduct of a higher alcohol, a fatty acid ester of polyethylene glycol, an alkyl (poly) glucoside, or a fatty acid ester of polyglycerin. <1> The method for producing an emulsion according to any one of <1> to <24>, comprising one or more selected from the group consisting of: and more preferably an oxyethylene adduct of a polyhydric alcohol fatty acid ester.

  <26> The content of water in the aqueous component is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, and even more preferably 98% by mass or more. % Or more, and substantially 100% by mass, the method for producing an emulsion according to any one of <1> to <25>.

  <27> The content of the liquid oil in the produced emulsion is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 4% by mass or more, and preferably 50% by mass or less. , More preferably 30% by mass or less, still more preferably 10% by mass or less, and still more preferably 8% by mass or less.

  <28> The content of the nonionic surfactant in the produced emulsion is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and further preferably 0.1% by mass or more. And preferably at most 2.0% by mass, more preferably at most 1.0% by mass, still more preferably at most 0.5% by mass, even more preferably at most 0.3% by mass. <1> Or a method for producing the emulsion according to any one of <27> to <27>.

[Test evaluation 1]
(Production of emulsion)
Production experiments of the following emulsions of Examples 1 to 3 and Comparative Examples 1 to 4 were performed. In Examples 1 to 3 and Comparative Examples 2 to 4, the micromixer 100 having the first configuration shown in FIGS. 2 and 3 was used in the emulsion production system A shown in FIG. 1 in the above embodiment. Each content is also shown in Tables 1-3.

  The segregation index (Xs) was calculated as follows.

  A borate buffer solution to replace the aqueous component and 0.171 N sulfuric acid to replace the oily component were prepared. The composition of the borate buffer was 0.045 mol / L of boric acid, 0.045 mol / L of sodium hydroxide, 0.00313 mol / L of potassium iodate, and 0.0156 mol / L of potassium iodide. These two liquids were mixed under the same conditions as in each example or each comparative example, and the absorbance of the solution after one minute with respect to light having a wavelength of 353 nm was measured. The absorbance was measured using a spectrophotometer (device name: UVmini-1240, manufactured by Shimadzu Corporation). Then, the segregation index (Xs) was calculated from the measurement result of the absorbance according to the above formula (IV).

<Example 1>
In Example 1, as a micromixer 100, the outer diameter _D 1 of the small diameter tube 111: 3 mm, an inside diameter _D 2 of the small-diameter pipe 111: 2 mm, inside diameter _D 3 of the large-diameter pipe 112: 4.71mm, diameter pipe 111 and the large-diameter The gap Δ with the pipe 112: 0.855 mm, the gap δ between the small-diameter pipe 111 and the large-diameter pipe 112: 0.25 mm, the distance L from the end of the fluid flow passage 110 to the pore 122: 0.68 mm, The cone convergence angle θ ₁ of the basin 121: 120 °, the hole diameter d of the fine holes 122: 0.22 mm, the length 1 of the fine holes 122: 0.55 mm, the flow area s of the fine holes 122: 0.038 mm ² , The length l of the hole 122 / the hole diameter d of the fine hole 122: 2.5, the cone expansion angle θ _{2 of} the flow path expanding section 131: 120 °, the maximum flow path diameter D _{4 of the} flow path expanding section 131: 2 mm, and the maximum flow. Configuration of road diameter D ₄ / pore diameter d of pore 122: 9.1 Was used.

  Ion exchange water was prepared as an aqueous component and charged in the aqueous component storage tank 41a.

  Fatty acid monoglyceride (trade name: Homotex PT (caprylic acid monoglyceride), HLB = 5.9, saponification value: 274.6 KOHmg / g, acid value: 388.8 KOHmg / g) manufactured by Kao Corporation as an oil component. Polyoxyethylene cured castor which is a nonionic surfactant having 6% by mass, 40.4% by mass of a higher alcohol (trade name: Calcol 200GD (2-octyldodecanol) manufactured by Kao Corporation), and 13.8% HLB. A homogeneous solution containing 8.0% by mass of oil (trade name: Emanon CH-60, manufactured by Kao Corporation, saponification value: 44 KOH mg / g, average number of moles of EO added: 60) was prepared and charged in the oil component storage tank 41b. . This oily component was liquid at normal temperature (20 ° C.), and had self-emulsifying properties with respect to ion exchange water as an aqueous component.

  Then, the emulsion production system A is operated, and at normal temperature (20 ° C.), the flow rate of the aqueous component is set to 1.71 L / h and the oil component is adjusted so that the mixing mass ratio of the aqueous component / oil component becomes 95/5. Was adjusted to 0.09 L / h, and they were mixed with a micromixer 100 to obtain an emulsion. At this time, the flow ratio of the aqueous component to the oil component (the flow rate of the aqueous component / the flow rate of the oil component) was 19. The flow rate of the fluid after joining the aqueous component and the oil component flowing through the pores 122 was 1.80 L / h. The pressure loss before and after the micromixer 100 was 0.3 MPa.

  The resulting emulsion had a fatty acid monoglyceride content of 2.58% by mass, a higher alcohol content of 2.02% by mass, a polyoxyethylene hydrogenated castor oil content of 0.40% by mass, and ion exchange. The water content was 95.00% by mass.

  The average particle diameter of the droplets of the oily component in the obtained emulsion was 0.32 μm. This is 1/688 of the pore diameter d of the pore 122. Here, the average particle size of the droplets of the oily component in the emulsion is measured by a laser scattering / diffraction method using a laser diffraction / scattering type particle size distribution measuring device (LA-910, manufactured by Horiba, Ltd.). It is the median diameter of the oil component (hereinafter, the same applies to Examples 2-3 and Comparative Examples 1-4).

The segregation index (Xs) in the emulsification operation of Example 1 was 3.4 × 10 ⁻³ . Incidentally, _{I 3} after mixing 1 minute ^- ions is a value calculated from the absorbance with respect to light having a wavelength of 353 nm, was 3.94 × ¹⁰ -6 mol / L. [H ⁺ ] ₀ and [I ₂ ] were 0.171 mol / L and 3.13 × 10 ⁻⁷ mol / L, respectively, and V _mixed / V _{sulfuric acid aqueous solution} was 20, so Y was 9. It was 95 * 10 <^-4> . Also, _[IO ³ _{-] 0} and _[H 2 _BO ³ _-] Because ₀ was respectively 0.00313mol / L and 0.045mol / _{L, Y ST} was 0.294. This is the same in the second embodiment.

<Example 2>
In Example 2, an emulsion was obtained in the same manner as in Example 1 except that the composition of the oily component was changed as described below.

  As oil components of Example 2, 53.8% by mass of fatty acid monoglyceride (trade name: Homotex PT, manufactured by Kao Corporation), 42.2% by mass of higher alcohol (trade name: Calcol 200GD, manufactured by Kao Corporation), and HLB were: A homogeneous solution containing 4.0% by mass of polyoxyethylene hydrogenated castor oil (trade name: Emanon CH-60, manufactured by Kao Corporation), which is a nonionic surfactant of 13.8, is prepared and charged in the oil component storage tank 41b. It is. This oily component was liquid at normal temperature (20 ° C.), and had self-emulsifying properties with respect to ion exchange water as an aqueous component.

  Then, the emulsion production system A is operated, and at normal temperature (20 ° C.), the flow rate of the aqueous component is set to 1.71 L / h and the oil component is adjusted so that the mixing mass ratio of the aqueous component / oil component becomes 95/5. Was adjusted to 0.09 L / h, and they were mixed with a micromixer 100 to obtain an emulsion. At this time, the flow ratio of the aqueous component to the oil component (the flow rate of the aqueous component / the flow rate of the oil component) was 19. The flow rate of the fluid after merging the aqueous component and the oil component flowing through the pores 122 was 1.8 L / h. The pressure loss before and after the micromixer 100 was 0.3 MPa.

  The resulting emulsion had a fatty acid monoglyceride content of 2.69% by mass, a higher alcohol content of 2.11% by mass, a polyoxyethylene hydrogenated castor oil content of 0.20% by mass, and ion exchange. The water content was 95.00% by mass.

  The average particle size of the oil component droplets in the obtained emulsion was 0.58 μm. This is 1/379 of the pore diameter d of the pore 122.

<Example 3>
In Example 3, as a micromixer 100, the outer diameter _D 1 of the small diameter tube 111: 8 mm, inner diameter _D 2 of the small-diameter pipe 111: 4 mm, inside diameter _D 3 of the large-diameter pipe 112: 10 mm, clearance delta: 1 mm, the gap [delta]: 0.5 mm, the distance L from the end of the fluid channel portion 110 to the pore 122: 1.29 mm, the cone convergence angle θ ₁ of the fluid junction area 121: 120 °, the pore diameter d of the pore 122: 0.68 mm, The length l of the hole 122 is 1.725 mm, the flow area s of the pore 122 is 0.363 mm ² , the length l of the pore 122 / the diameter d of the pore 122 is 2.5, A configuration having a cone expansion angle θ _{2 of} 120 °, a maximum flow path diameter D _{4 of the} flow path expansion section 131 of 7 mm, and a maximum flow path diameter D ₄ / pore diameter d of the fine holes 122 of 10.3 was used.

  Ion exchange water was prepared as an aqueous component and charged in the aqueous component storage tank 41a.

  51.6% by mass of fatty acid monoglyceride (trade name: Homotex PT manufactured by Kao Corporation) and 40.4% by mass of higher alcohol (trade name: Calcol 200GD (2-octyldodecanol)) as an oil component, And polyoxyethylene hydrogenated castor oil having a HLB of 9.8 (trade name: Emanon CH-25, saponification value: 75 KOHmg / g, average number of moles of added EO: 25, manufactured by Kao Corporation) which is a nonionic surfactant. A homogeneous solution containing 8.0% by mass was prepared and charged in the oil component storage tank 41b. This oily component was liquid at normal temperature (20 ° C.), and had self-emulsifying properties with respect to ion exchange water as an aqueous component.

  Then, the emulsion production system A is operated, and at normal temperature (20 ° C.), the flow rate of the aqueous component is set to 17.1 L / h and the oil component is adjusted so that the mixing mass ratio of the aqueous component / oil component becomes 95/5. Was set to 0.9 L / h, and they were mixed with a micromixer 100 to obtain an emulsion. At this time, the flow ratio of the aqueous component to the oil component (the flow rate of the aqueous component / the flow rate of the oil component) was 19. The flow rate of the fluid after the aqueous component and the oil component flowing through the pores 122 were combined was 18.0 L / h. The pressure loss before and after the micromixer 100 was 0.31 MPa.

  The average particle size of the oil component droplets in the obtained emulsion was 0.87 μm. This is 1/345 of the pore diameter d of the pore 122.

Further, the segregation index (Xs) in the emulsification operation of Example 3 was 5.3 × 10 ⁻³ . Incidentally, _{I 3} after mixing 1 minute ^- ions is a value calculated from the absorbance with respect to light having a wavelength of 353 nm, was 6.19 × ¹⁰ -6 mol / L. [H ⁺ ] ₀ and [I ₂ ] were 0.171 mol / L and 4.92 × 10 ⁻⁷ mol / L, respectively, and _after V _mixing / V _{sulfuric acid aqueous solution} was 20, Y was 1. It was 56 × 10 ⁻³ . Also, _[IO ³ _{-] 0} and _[H 2 _BO ³ _-] Because ₀ was respectively 0.00313mol / L and 0.045mol / _{L, Y ST} was 0.294.

<Comparative Example 1>
The same aqueous component and oil component as in Example 1 were prepared.

  Then, after mixing 760.0 g of the aqueous component and 40.0 g of the oil component in a beaker, the mixture was mixed for 1 minute at a rotation speed of 8000 r / min using a homomixer (trade name: TK homomixer MARKII2.5, manufactured by Primix). Thus, an emulsion was prepared.

  The resulting emulsion had a fatty acid monoglyceride content of 2.58% by mass, a higher alcohol content of 2.02% by mass, a polyoxyethylene hydrogenated castor oil content of 0.40% by mass, and ion exchange. The water content was 95.00% by mass.

  The average particle size of the droplets of the oily component in the obtained emulsion was 3.1 μm.

The segregation index (Xs) in the emulsification operation of Comparative Example 1 was 2.3 × 10 ⁻¹ . Incidentally, _{I 3} after mixing 1 minute ^- ions is a value calculated from the absorbance with respect to light having a wavelength of 353 nm, was 2.68 × ¹⁰ -4 mol / L. [H ⁺ ] ₀ and [I ₂ ] were 0.171 mol / L and 2.13 × 10 ⁻⁵ mol / L, respectively, and the V / V _{sulfuric acid aqueous solution} was 20 _after V _mixing . It was 76 * 10 ^<-2> . Also, _[IO ³ _{-] 0} and _[H 2 _BO ³ _-] Because ₀ was respectively 0.00313mol / L and 0.045mol / _{L, Y ST} was 0.294.

<Comparative Example 2>
In Comparative Example 2, an emulsion was obtained in the same manner as in Example 1 except that the composition of the oily component was changed as described below.

  Polyoxyethylene hydrogenated castor oil which is a nonionic surfactant having a synthetic ceramide (trade name: sphingospid E, manufactured by Kao Corporation) of 88.0% by mass and an HLB of 13.8 as an oil component of Comparative Example 2 A uniform solution containing 12.0% by mass (Kao Corporation product name: Emanon CH-60) and adjusted to 80.0 ° C. was prepared and charged in the oil component storage tank 41b. This oily component was solid at normal temperature (20 ° C.), and had self-emulsifying properties with respect to ion-exchanged water as an aqueous component.

  Then, the emulsion production system A is operated, and at 80 ° C., the flow rate of the aqueous component is set to 1.71 L / h and the flow rate of the oily component is set to 0 so that the mixing mass ratio of the aqueous component / oil component becomes 95/5. 0.09 L / h, and they were mixed with a micromixer 100 to obtain an emulsion. At this time, the flow ratio of the aqueous component to the oil component (the flow rate of the aqueous component / the flow rate of the oil component) was 19. The flow rate of the fluid after merging the aqueous component and the oil component flowing through the pores 122 was 1.8 L / h. The pressure loss before and after the micromixer 100 was 0.3 MPa.

  In the obtained emulsion, the content of synthetic ceramide was 4.40% by mass, the content of polyoxyethylene hydrogenated castor oil was 0.60% by mass, and the content of ion-exchanged water was 95.00% by mass. Was.

  When the obtained emulsion was cooled, crystals on the order of millimeters were precipitated.

<Comparative Example 3>
In Comparative Example 3, an emulsion was obtained in the same manner as in Example 1 except that the compositions of the aqueous component and the oil component were changed as described below.

  As an aqueous component of Comparative Example 3, a 0.42% by mass aqueous solution of polyoxyethylene hydrogenated castor oil (trade name: Emanon CH-60, manufactured by Kao Corporation) as a nonionic surfactant having an HLB of 13.8 was prepared. Into the aqueous component storage tank 41a.

  A homogeneous solution containing 56.1% by mass of fatty acid monoglyceride (trade name: Homotex PT, manufactured by Kao Corporation) and 43.9% by mass of higher alcohol (trade name: Calcol 200GD, manufactured by Kao Corporation) as oil components of Comparative Example 3. Was prepared and charged in the oil component storage tank 41b. This oily component was liquid at ordinary temperature (20 ° C.) and did not have self-emulsifying property with respect to the aqueous polyoxyethylene hydrogenated castor oil solution.

  Then, the emulsion production system A is operated, and at normal temperature (20 ° C.), the flow rate of the aqueous component is set to 1.72 L / so that the mixing mass ratio of the aqueous component / oil component becomes 95.4 / 4.6. h and the flow rate of the oily component were set to 0.08 L / h, and they were mixed with a micromixer 100 to obtain an emulsion. At this time, the flow rate ratio of the aqueous component to the oil component (the flow rate of the aqueous component / the flow rate of the oil component) was 21.5. The flow rate of the fluid after merging the aqueous component and the oil component flowing through the pores 122 was 1.8 L / h. The pressure loss before and after the micromixer 100 was 0.3 MPa.

  The resulting emulsion had a fatty acid monoglyceride content of 2.58% by mass, a higher alcohol content of 2.02% by mass, a polyoxyethylene hydrogenated castor oil content of 0.40% by mass, and ion exchange. The water content was 95.00% by mass.

  The average particle size of the droplets of the oily component in the obtained emulsion was 3.5 μm. This is 1/63 of the pore diameter d of the pore 122.

<Comparative Example 4>
In Comparative Example 4, an emulsion was obtained in the same manner as in Example 1 except that the composition of the oily component was changed as described below.

  As the oily components of Comparative Example 4, 51.6% by mass of fatty acid monoglyceride (trade name: Homotex PT manufactured by Kao Corporation), 40.4% by mass of higher alcohol (trade name: Calcol 200GD, manufactured by Kao Corporation), and HLB Sorbitan fatty acid ester (trade name: Reodol AO-10V, Kao Corporation; saponification value: 147 KOH mg / g, acid value: 201 KOH mg / g, manufactured by Kao Corporation) as a nonionic surfactant having a mass ratio of 5.4% by mass. A homogeneous solution was prepared and charged in the oil component storage tank 41b. This oily component was liquid at normal temperature (20 ° C.) and had no self-emulsifying property with respect to the aqueous component ion-exchanged water.

  Then, the emulsion production system A is operated, and at normal temperature (20 ° C.), the flow rate of the aqueous component is set to 1.71 L / h and the oil component is adjusted so that the mixing mass ratio of the aqueous component / oil component becomes 95/5. Was adjusted to 0.09 L / h, and they were mixed with a micromixer 100 to obtain an emulsion. At this time, the flow ratio of the aqueous component to the oil component (the flow rate of the aqueous component / the flow rate of the oil component) was 19. The flow rate of the fluid after merging the aqueous component and the oil component flowing through the pores 122 was 1.8 L / h. The pressure loss before and after the micromixer 100 was 0.3 MPa.

  In the obtained emulsion, the content of fatty acid monoglyceride was 2.58% by mass, the content of higher alcohol was 2.02% by mass, the content of sorbitan fatty acid ester was 0.40% by mass, and the content of ion-exchanged water was The amount was 95.00% by mass.

  The average particle size of the oil component droplets in the obtained emulsion was 5.3 μm. This is 1/42 of the pore diameter d of the pore 122.

(Consideration of results)
Examples 1 to 5 in which an aqueous component of ion-exchanged water and an oil component containing an oil agent that is liquid at 20 ° C and containing 10% by mass or less of a nonionic surfactant having an HLB of 7 or more were emulsified by a micromixer. In each of the examples, the average particle diameter of the oil component droplets in the obtained emulsion was 1 μm or less.

  On the other hand, Comparative Example 1 emulsified by a homomixer, Comparative Example 2 in which the oily component and the synthetic ceramide contained therein were solid at 20 ° C., Comparative Example 3 in which the aqueous component contained a nonionic surfactant, and the oily component In Comparative Example 4, in which the sorbitan fatty acid ester having an HLB of 5.4 was contained, the average particle diameter of the oil component droplets in the obtained emulsion was 3.0 μm or more.

[Test evaluation 2]
Production experiments of the following emulsions of Examples 4 and 5 were conducted. Example 4 uses the micromixer 200 having the second configuration shown in FIG. 5 in the emulsion production system A shown in FIG. 1 in the above embodiment, and Example 5 uses the micromixer 200 shown in FIGS. 7A to 7C. The micro mixer 300 having the third configuration shown was used. The contents of each are also shown in Tables 4 and 5.

<Example 4>
FIG. 9A illustrates a dimensional configuration of the micromixer 200 having the second configuration used in the fourth embodiment. In the micromixer 200 of the second configuration, the fine holes 222 were cylindrical holes, and the hole diameter was 0.3 mm and the hole length was 0.9 mm.

  Using the micromixer 200 of the second configuration, an emulsion was prepared under the same conditions as in Example 1 except that the flow rate of the aqueous component was set to 3.42 L / h and the flow rate of the oily component was set to 0.18 L / h. . At this time, the flow ratio of the aqueous component to the oil component (the flow rate of the aqueous component / the flow rate of the oil component) was 19. The flow rate of the fluid after joining the aqueous component and the oil component flowing through the pores 222 was 3.6 L / h. The pressure loss before and after the micromixer 200 was 0.27 MPa.

  The resulting emulsion had a fatty acid monoglyceride content of 2.58% by mass, a higher alcohol content of 2.02% by mass, a polyoxyethylene hydrogenated castor oil content of 0.40% by mass, and ion exchange. The water content was 95.00% by mass.

  The average particle size of the oil component droplets in the obtained emulsion was 0.58 μm. This is 1/379 of the pore diameter d of the pore 222.

The segregation index (Xs) in the emulsification operation of Example 4 was 8.1 × 10 ⁻² . Incidentally, _{I 3} after mixing 1 minute ^- ions is a value calculated from the absorbance with respect to light having a wavelength of 353 nm, was 2.4 × ¹⁰ -5 mol / L. In addition, since [H ⁺ ] ₀ and [I ₂ ] were 0.171 mol / L and 1.9 × 10 ⁻⁶ mol / L, respectively, and _after V _mixing / V _{sulfuric acid aqueous solution} was 20, Y was 2. It was 4 * 10 ^<-2> . Also, _[IO ³ _{-] 0} and _[H 2 _BO ³ _-] Because ₀ was respectively 0.00313mol / L and 0.045mol / _{L, Y ST} was 0.294.

<Example 5>
FIG. 9B shows a dimensional configuration of the micromixer 300 having the third configuration used in the fifth embodiment. In the micromixer 300 of the third configuration, the pores 322 were cylindrical holes, the diameter of which was 0.3 mm, and the length of the holes was 0.9 mm.

  Using the micromixer 300 of the third configuration, an emulsion was prepared under the same conditions as in Example 1 except that the flow rate of the aqueous component was 3.42 L / h and the flow rate of the oily component was 0.18 L / h. . At this time, the flow ratio of the aqueous component to the oil component (the flow rate of the aqueous component / the flow rate of the oil component) was 19. The flow rate of the fluid after joining the aqueous component and the oil component flowing through the pores 322 was 3.6 L / h. The pressure loss before and after the micromixer 300 was 0.26 MPa.

  The resulting emulsion had a fatty acid monoglyceride content of 2.58% by mass, a higher alcohol content of 2.02% by mass, a polyoxyethylene hydrogenated castor oil content of 0.40% by mass, and ion exchange. The water content was 95.00% by mass.

  The average particle diameter of the oil component droplets in the obtained emulsion was 0.31 μm. This is 1/710 of the pore diameter d of the pore 322.

The segregation index (Xs) in the emulsification operation of Example 5 was 3.5 × 10 ⁻² . Incidentally, _{I 3} after mixing 1 minute ^- ions is a value calculated from the absorbance with respect to light having a wavelength of 353 nm, was 1.0 × ¹⁰ -5 mol / L. [H ⁺ ] ₀ and [I ₂ ] were 0.171 mol / L and 8.0 × 10 ⁻⁷ mol / L, respectively, and _after V _mixing / V _{sulfuric acid aqueous solution} was 20, Y was 1. It was ^0x10-2 . Also, _[IO ³ _{-] 0} and _[H 2 _BO ³ _-] Because ₀ was respectively 0.00313mol / L and 0.045mol / _{L, Y ST} was 0.294.

  The present invention is useful for a method for producing an emulsion.

A Emulsion production system 100, 200, 300 Micro mixer 101, 201 Aqueous component supply unit 102, 202 Oily component supply unit 103, 203, 303 Emulsion recovery unit 110, 310 Fluid flow path unit 111, 311 Small diameter pipe 111a, 211a , 311a First flow path 111b Tube end portions 112, 312 Large diameter pipes 112a, 212a, 312a Second flow paths 120, 320 Fluid converging / contracting parts 121, 221 and 321 Fluid converging areas 122, 222 and 322 Pores 130 330 Fluid outflow portions 131, 231, 331 Channel expansion portion 210 Straight pipe portion 220 Branch pipe portion 41a Aqueous component storage tank 41b Oily component storage tank 42a Aqueous component supply pipe 42b Oily component supply pipe 43a First pump 43b Second pump 44a First Flow meter 44b Second flow meter 45a First filter 45b Second filter 1st pressure gauge 46b 2nd pressure gauge 47 Flow controller 48 Emulsion collection pipe 49 Emulsion collection tank

Claims (11)

A liquid aqueous component, a liquid oil component containing an oil agent that is liquid at 20 ° C. and having a self-emulsifying property with respect to the aqueous component containing a nonionic surfactant having an HLB of 7 or more and 10% by mass or less, Merging step;
A pore flowing step of flowing the fluid after the water component and the oil component are merged in the pores in the merging step,
Including
In the merging step, the oil component is merged with the aqueous component that has flowed out from the flow channel whose flow channel diameter is larger than the pore diameter of the pores,
The emulsification operation of the aqueous component and the oil component is performed under the condition that the segregation index (Xs) is 0.1 or less. The average particle size of the emulsified droplet in the aqueous component is 1/100 of the pore size of the pore. The following is a method for producing an emulsion in which the oily component is dispersed. A joining step of joining a liquid aqueous component and a liquid oil component containing an oil agent that is liquid at 20 ° C. and containing 10% by mass or less of a nonionic surfactant having an HLB of 7 or more;
A pore circulation step of allowing the fluid after the aqueous component and the oil component to be merged in the merge step to flow through the pores;
Including
In the merging step, the oil component is merged from the entire periphery thereof with the aqueous component flowing out of the flow channel whose flow path diameter is larger than the pore diameter of the pores ,
The emulsifying operation of the aqueous component and the oil component is performed under the condition that the segregation index (Xs) is 0.1 or less. The average particle size of the emulsified droplet in the aqueous component is 1/100 of the pore size of the pore. The following is a method for producing an emulsion in which the oily component is dispersed. A joining step of joining a liquid aqueous component and a liquid oil component containing an oil agent that is liquid at 20 ° C. and containing 10% by mass or less of a nonionic surfactant having an HLB of 7 or more;
A fluid circulation step in which the fluid after the aqueous component and the oil component are merged in the merging step is passed through pores extending in directions different from the flow directions of the aqueous component and the oil component,
Only including,
In the merging step, the oil component is merged with the aqueous component that has flowed out from the flow channel whose flow channel diameter is larger than the pore diameter of the pores,
The emulsifying operation of the aqueous component and the oil component is performed under the condition that the segregation index (Xs) is 0.1 or less. The average particle size of the emulsified droplet in the aqueous component is 1/100 of the pore size of the pore. The following is a method for producing an emulsion in which the oily component is dispersed. The method for producing an emulsion according to claim 3 , wherein in the joining step, the aqueous component and the oil component are caused to collide with each other by head-on collision. Is a direction in which the extending direction of the pores are perpendicular to the flow direction of the aqueous component and the oily component, the manufacturing method of the emulsion according to claim 3 or 4. The method for producing an emulsion according to any one of claims 2 to 5 , wherein the oily component has a self-emulsifying property with respect to the aqueous component. The method for producing an emulsion according to any one of claims 1 to 6 , wherein the average particle diameter of the emulsion droplets of the oil component in the produced emulsion is 0.5 µm or less. The method for producing an emulsion according to any one of claims 1 to 7 , wherein a ratio (length / pore diameter) of the length of the pores to the pore diameter is 5 or less. The method for producing an emulsion according to any one of claims 1 to 8 , wherein the content of the oil agent that is liquid at 20 ° C in the produced emulsion is 8% by mass or less. The method for producing an emulsion according to any one of claims 1 to 9 , wherein the nonionic surfactant has an HLB of 9 or more. The method for producing an emulsion according to any one of claims 1 to 10, wherein the content of the oil agent that is liquid at 20 ° C in the oil component is 80% by mass or more.

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