Process for producing an oil-in-water emulsion

Abstract

The present invention relates to a method for producing an oil-in-water emulsion, wherein an oil-in-water pre-emulsion (L1) obtained by dispersing an oil phase in a first water phase is added in a jet stream to a second water phase (L2).

Description

Technical Field

[0001] This invention relates to a method for manufacturing oil-in-water emulsions. Background Technology

[0002] Methods for manufacturing emulsions by mixing pre-prepared raw material emulsions in an aqueous or oil phase to produce a final product are known. For example, Patent Document 1 discloses a method in which a primary emulsion obtained by dispersing droplets of phase A in phase B is used as a starting material. This primary emulsion is placed in a container made of a coaxial cylinder and subjected to shear stress, thereby producing a secondary emulsion in which the diameter of the droplets of phase A is smaller than that of the primary emulsion. Patent Document 2 discloses a method for manufacturing an emulsion in which a portion of the aqueous phase and all of the oil phase, all of the aqueous phase and a portion of the oil phase, or a portion of the aqueous phase and a portion of the oil phase are continuously fed into an emulsifier to generate a pre-emulsion. The pre-emulsion and the remaining aqueous and / or oil phase are then fed into another emulsifier for stirring and mixing.

[0003] Furthermore, there are known mixing methods in which one of the two liquids is ejected into the other in a jet state. For example, Patent Document 3 discloses a method for manufacturing a fatty acid neutralizer by ejecting a fatty acid complex liquid into an alkaline aqueous solution in a jet state.

[0004] Existing technical documents:

[0005] Patent Document 1: Japanese Patent Publication No. 11-509473

[0006] Patent Document 2: Japanese Patent Application Publication No. 5-154367

[0007] Patent Document 3: International Publication No. 2020 / 129723 Summary of the Invention

[0008] This invention relates to a method for manufacturing an oil-in-water emulsion by spraying an oil-in-water pre-emulsion obtained by dispersing an oil phase in a first aqueous phase into a second aqueous phase. Attached Figure Description

[0009] Figure 1 This is a diagram showing the structure of the water-in-oil emulsion manufacturing apparatus used in the embodiments.

[0010] Symbol Explanation

[0011] 10…Water-in-oil emulsion manufacturing apparatus

[0012] 11…Preparation slot

[0013] 12…Matching groove

[0014] 13…Liquid supply pipe

[0015] 14…Jet nozzle (jet discharge section)

[0016] 15…pump

[0017] L1…preemulsion

[0018] L2…Second liquid phase Detailed Implementation

[0019] The implementation method will be described in detail below.

[0020] The method for manufacturing an oil-in-water emulsion according to the embodiment involves jetting an oil-in-water pre-emulsion obtained by dispersing an oil phase in a first aqueous phase into a second aqueous phase. Here, "jet state" in this application refers to a state in which the oil-in-water pre-emulsion obtained by dispersing an oil phase in a first aqueous phase is jetted from an orifice disposed in the second aqueous phase into a wider area filling the second aqueous phase, forming droplets of the pre-emulsion smaller than the orifice diameter, which can be visually confirmed to diffuse from the orifice. "Jet addition" in this application refers to adding the oil-in-water pre-emulsion in a "jet state" from an orifice disposed in the second aqueous phase into a wider area filling the second aqueous phase.

[0021] However, in the production of low-viscosity emulsions, since high-shear mixing of the oil and water phases is not required, a simpler mixer can be used. This mixer has low setup and maintenance costs, excellent cleaning performance, and is suitable for mass production.

[0022] On the other hand, in the manufacture of high-viscosity emulsions, high-shear mixing of the oil and water phases requires the use of complex mixers. These mixers suffer from high introduction and maintenance costs, poor cleaning performance, and are unsuitable for mass production.

[0023] In contrast, according to the method for manufacturing oil-in-water emulsions according to the embodiments, a device with a simple structure having a mixing tank having a jet outlet portion like a jet nozzle is used to add a pre-emulsion jet to a second aqueous phase accumulated in the mixing tank from the jet outlet portion. This allows the production of oil-in-water emulsions with small average oil phase particles, regardless of their viscosity. This is presumably because, when the pre-emulsion jet is added to the second aqueous phase, an oil-water interface is already formed during jetting, thus efficiently imparting shear force to the oil phase interface, thereby promoting the refinement of the oil phase.

[0024] Therefore, the cost of introducing and maintaining this equipment can be kept low. Furthermore, due to the equipment's excellent cleanability, the switching between manufactured oil-in-water emulsions can be performed quickly, resulting in high productivity. Consequently, large-scale production of oil-in-water emulsions in a single batch is possible.

[0025] In the method for manufacturing an oil-in-water emulsion in the embodiment, firstly, the oil phase and the first aqueous phase are mixed to prepare an oil-in-water pre-emulsion.

[0026] There are no particular limitations on the preparation method of pre-emulsions. Examples include common high-pressure emulsification, phase inversion emulsification, membrane emulsification, and D-phase emulsification.

[0027] Examples of oil phases include: fragrances, oils, antioxidants, cooling agents, dyes, pigments, silicones, solvents, and oil-soluble polymers. The oil phase preferably contains one or more of these components. From the viewpoint of producing an oil-in-water emulsion with a small average particle size of the oil phase and improving the stability of the oil-in-water emulsion, it is more preferable to include oils and / or silicones, and even more preferably, silicones.

[0028] The oil is preferably an organic compound with a solubility of less than 1 g in 100 g of water. The solubility of the oil in 100 g of water is the solubility at 25°C (1013.25 hPa). The solubility of the oil in 100 g of water is preferably 0.5 g or less, more preferably 0.1 g or less, and can also be 0 g. For methods of determining solubility, please refer to, for example, the Journal of the Chemical Society of Japan, 1985, No. 11, pp. 2116-2119, and the Journal of the Chemical Society of Japan, 1982, No. 11, pp. 1830-1834.

[0029] Examples of oiling agents include liquid oils that are liquid at 20°C and solid greases that are solid at 20°C. An oiling agent may contain only liquid oil, or only solid grease, or both, or any combination thereof.

[0030] Examples of oils include: alcohols, ester oils, hydrocarbon oils, dialkyl ether compounds, amine compounds, amide compounds, fats, and higher fatty acids. Preferably, the oil contains one or more of these. Additionally, the oil may include oils used as fragrances, antioxidants, cooling agents, humectants, dyes, pigments, etc.

[0031] Examples of silicones include: dimethylpolysiloxane, methylpolysiloxane, methylphenylpolysiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, methylhydropolysiloxane, silicone resins, amino-modified silicones, alkyl-modified silicones, polyether-modified silicones, glycerol-modified silicones, silicone waxes, etc. The silicone preferably contains one or more of these, and from the viewpoint of obtaining a dispersion of fine particles, dimethylpolysiloxane is more preferred. It should be noted that the silicone may contain silicones used as tactile enhancers or moisturizing ingredients.

[0032] The first aqueous phase can be water alone, or it can be an aqueous solution containing water-soluble substances dissolved in water. Examples of water-soluble substances include thickeners and emulsion stabilizers. From the viewpoint of improving the stability of oil-in-water emulsions, the thickener preferably contains one or more polysaccharides, more preferably sodium alginate, carboxymethyl cellulose and its salts, carrageenan, xanthan gum, sodium polyacrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, pectin, tragacanth gum, gum arabic, guar gum, ark tarragon gum, locust bean gum, gellan gum, tamarind gum, and psyllium gum, and even more preferably locust bean gum. From the viewpoint of improving the stability of oil-in-water emulsions, the emulsion stabilizer preferably contains one or more compounds with polar groups, more preferably one or more neutral compounds, even more preferably one or more neutral polymers, and even more preferably polyvinyl alcohol. Furthermore, the first aqueous phase can be a dispersion in which dispersed particles are dispersed in water.

[0033] From the viewpoint of increasing the freedom of formulation, the mass ratio (oil phase / first aqueous phase) of the oil phase content to the first aqueous phase content in the preemulsion is preferably 0.01 or more, more preferably 0.05 or more, further preferably 0.1 or more, and even more preferably 0.3 or more. From the viewpoint of obtaining a stable oil-in-water preemulsion, it is preferably 4 or less, more preferably 3.5 or less, even more preferably 3 or less, and even more preferably 2 or less.

[0034] From the viewpoint of producing oil-in-water emulsions with a small average particle size of the oil phase, the average particle size of the oil phase in the preemulsion is preferably 2000 μm or less, more preferably 1000 μm or less, even more preferably 500 μm or less, even more preferably 100 μm or less, even more preferably 70 μm or less, preferably 1 μm or more, and more preferably 10 μm or more. Here, the average particle size of the oil phase in this application is the area-based average particle size measured by laser diffraction scattering using a laser diffraction / scattering particle size distribution measuring device.

[0035] In the method for manufacturing an oil-in-water emulsion according to the embodiment, after preparing a pre-emulsion, the pre-emulsion is jetted into a second aqueous phase, thereby obtaining the final oil-in-water emulsion.

[0036] The second aqueous phase can be water alone, but like the first aqueous phase, it can be an aqueous solution containing water-soluble substances dissolved in water, or a dispersion containing dispersed particles in water. Preferably, the composition of the second aqueous phase is the same as that of the first aqueous phase of the preemulsion. The second aqueous phase can have the same composition as the first aqueous phase, or it can have a different composition.

[0037] The addition of the pre-emulsion to the second aqueous phase is preferably performed using a nozzle. In this case, it is preferable that the tip of the nozzle is in the second aqueous phase. From a productivity point of view, the inner diameter of the nozzle is preferably 0.01 mm or more, more preferably 0.05 mm or more, and even more preferably 0.1 mm or more. From the viewpoint of spraying the pre-emulsion, it is preferably 20 mm or less, more preferably 10 mm or less, and even more preferably 1 mm or less. Furthermore, when the nozzle opening shape is not perfectly circular, the inner diameter of the nozzle is the hydraulic diameter of the opening shape.

[0038] From the viewpoint of suppressing the creaming of the preemulsion, the viscosity of the preemulsion at the temperature at which it is added to the second aqueous phase via jetting is preferably 1 mPa·s or more, more preferably 10 mPa·s or more, and even more preferably 100 mPa·s or more. From the viewpoint of reducing the pressure loss of the nozzle, it is preferably 15,000 mPa·s or less, more preferably 10,000 mPa·s or less, and even more preferably 6,000 mPa·s or less.

[0039] From the viewpoint of suppressing emulsification in the manufactured oil-in-water emulsion, the viscosity of the second aqueous phase at the temperature at which the preemulsion is added via jet is preferably 0.1 mPa·s or more, more preferably 0.5 mPa·s or more, and most preferably 1.0 mPa·s or more. From the viewpoint of miscibility, it is preferably 20,000 mPa·s or less, more preferably 10,000 mPa·s or less, more preferably 6,000 mPa·s or less, more preferably 1,000 mPa·s or less, further preferably 500 mPa·s or less, and most preferably 10 mPa·s or less. From the viewpoint of producing an oil-in-water emulsion with a small average particle size of the oil phase, the viscosity of the second aqueous phase is preferably lower than the viscosity of the preemulsion.

[0040] From the viewpoint of producing an oil-in-water emulsion with a small average particle size in the oil phase, the linear velocity of the pre-emulsion when it is added to the second aqueous phase via jetting is preferably 5 m / s or more, more preferably 10 m / s or more, even more preferably 20 m / s or more, and even more preferably 30 m / s or more. From the viewpoint of reducing the load on the apparatus, it is preferably 100 m / s or less, more preferably 50 m / s or less, and even more preferably 40 m / s or less. Here, the "linear velocity of the pre-emulsion" in this application refers to the velocity of the liquid in the discharge direction of the pre-emulsion. Furthermore, the absolute value of the linear velocity of the pre-emulsion is calculated as follows: divide the mass flow rate of the pre-emulsion by the density of the pre-emulsion, then divide that by the area of ​​the discharge orifice, and convert it to a value per second.

[0041] From the perspective of effectively imparting shear to the oil-water interface between the preemulsion and the second aqueous phase, thereby refining the oil phase, the preferred shear rate when the preemulsion is jet-added to the second aqueous phase is 0.25 kb / s.-1 The above is preferred to be 0.5 million s. -1 The above is further optimized to 10,000 seconds. -1 The above is further optimized to 20,000 seconds. -1 The above is further optimized to 30,000 seconds. -1 From the perspective of reducing the load on the equipment, 500,000 seconds is preferred. -1 Below, 400,000 s is preferred. -1 The following is a further preferred option: 300,000 s -1 The shear rate is calculated by dividing the linear velocity of the pre-emulsion by the inner diameter of the nozzle when adding the pre-emulsion to the second aqueous phase using a nozzle (linear velocity of pre-emulsion / inner diameter of nozzle).

[0042] The average particle size of the oil phase in the manufactured oil-in-water emulsion is preferably 35 μm or less, more preferably 30 μm or less, even more preferably 20 μm or less, and more preferably 1 μm or more.

[0043] From the viewpoint of energy saving and emulsification, the ratio of the average particle size of the oil phase in the oil-in-water emulsion to the average particle size of the oil phase in the pre-emulsion (average particle size of the oil phase in the oil-in-water emulsion / average particle size of the oil phase in the pre-emulsion) is preferably 0.001 or more, more preferably 0.01 or more, and even more preferably 0.1 or more. Furthermore, from the viewpoint of manufacturing fine emulsions, it is preferably 0.9 or less, more preferably 0.7 or less, and even more preferably 0.6 or less.

[0044] Regarding the above-described embodiments, the present invention also discloses the following methods.

[0045] [1] A method for manufacturing an oil-in-water emulsion, wherein an oil-in-water pre-emulsion obtained by dispersing an oil phase in a first aqueous phase is added to a second aqueous phase.

[0046] [2] According to the method for manufacturing an oil-in-water emulsion described in [1], the viscosity of the second aqueous phase at the temperature at which the pre-emulsion is added by jet is above 0.1 mPa·s and below 20000 mPa·s.

[0047] [3] The method for manufacturing an oil-in-water emulsion according to [1] or [2], wherein the viscosity of the second aqueous phase at the temperature at which the pre-emulsion is added by jet is above 0.1 mPa·s and below 10000 mPa·s.

[0048] [4] The method for manufacturing an oil-in-water emulsion according to any one of [1] to [3], wherein the viscosity of the second aqueous phase at the temperature at which the pre-emulsion is added by jet is more than 1 mPa·s and less than 10,000 mPa·s.

[0049] [5] The method for manufacturing an oil-in-water emulsion according to any one of [1] to [4], wherein the viscosity of the second aqueous phase at the temperature at which the pre-emulsion is added by jet is 1 mPa·s or more and 6000 mPa·s or less.

[0050] [6] A method for manufacturing an oil-in-water emulsion according to any one of [1] to [5], wherein the pre-emulsion is added by jetting from the jetting outlet to the second aqueous phase accumulated in the stirring tank using a mixing tank having a jetting outlet.

[0051] [7] The method for manufacturing an oil-in-water emulsion according to any one of [1] to [6], wherein the mass ratio of the content of the oil phase in the pre-emulsion to the content of the first aqueous phase is 0.01 or more and 4 or less.

[0052] [8] A method for manufacturing an oil-in-water emulsion according to any one of [1] to [7], wherein the mass ratio of the content of the oil phase in the pre-emulsion to the content of the first aqueous phase is 0.01 or more and 3 or less.

[0053] [9] A method for manufacturing an oil-in-water emulsion according to any one of [1] to [8], wherein the mass ratio of the content of the oil phase in the pre-emulsion to the content of the first aqueous phase is 0.05 or more and 3 or less.

[0054]

[10] The method for manufacturing an oil-in-water emulsion according to any one of [1] to [9], wherein the mass ratio of the content of the oil phase in the pre-emulsion to the content of the first aqueous phase is 0.1 or more and 3 or less.

[0055]

[11] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[10] , wherein the mass ratio of the content of the oil phase in the pre-emulsion to the content of the first aqueous phase is 0.1 or more and 2 or less.

[0056]

[12] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[11] , wherein the average particle size of the oil phase in the pre-emulsion is 2000 μm or less.

[0057]

[13] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[12] , wherein the average particle size of the oil phase in the pre-emulsion is less than 1000 μm.

[0058]

[14] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[13] , wherein the average particle size of the oil phase in the pre-emulsion is 1 μm or more and 500 μm or less.

[0059]

[15] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[14] , wherein the average particle size of the oil phase in the pre-emulsion is 10 μm or more and 100 μm or less.

[0060]

[16] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[15] , wherein the viscosity of the pre-emulsion at the temperature at which it is added to the second aqueous phase by jet is 1 mPa·s or more and 15000 mPa·s or less.

[0061]

[17] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[16] , wherein the viscosity of the pre-emulsion at the temperature at which it is added to the second aqueous phase by jet is 1 mPa·s or more and 10,000 mPa·s or less.

[0062]

[18] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[17] , wherein the viscosity of the pre-emulsion at the temperature at which it is added to the second aqueous phase by jet is 1 mPa·s or more and 6000 mPa·s or less.

[0063]

[19] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[18] , wherein the viscosity of the pre-emulsion at the temperature at which it is added to the second aqueous phase by jet is 10 mPa·s or more and 6000 mPa·s or less.

[0064]

[20] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[19] , wherein the viscosity of the second aqueous phase (at the temperature at which the pre-emulsion is added by jet) is lower than the viscosity of the pre-emulsion (at the temperature at which it is added by jet to the second aqueous phase).

[0065]

[21] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[20] , wherein the composition of the second aqueous phase is the same as the composition of the first aqueous phase of the preemulsion.

[0066]

[22] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[21] , wherein the average particle size of the oil phase in the manufactured oil-in-water emulsion is 35 μm or less.

[0067]

[23] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[22] , wherein the average particle size of the oil phase in the manufactured oil-in-water emulsion is 30 μm or less.

[0068]

[24] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[23] , wherein the average particle size of the oil phase in the manufactured oil-in-water emulsion is 1 μm or more and 20 μm or less.

[0069]

[25] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[24] , wherein the linear velocity of the pre-emulsion when it is added to the second aqueous phase by jet is 5 m / s or more.

[0070]

[26] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[25] , wherein the linear velocity of the pre-emulsion when it is added to the second aqueous phase by jet is 5 m / s or more and 100 m / s or less.

[0071]

[27] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[26] , wherein the linear velocity of the pre-emulsion when it is added to the second aqueous phase by jet is 10 m / s or more and 100 m / s or less.

[0072]

[28] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[27] , wherein the oil phase comprises an oiling agent and / or a silicone.

[0073]

[29] According to the method for manufacturing oil-in-water emulsions described in

[28] , the oil agent comprises one or more of alcohols, ester oils, hydrocarbon oils, dialkyl ether compounds, amine compounds, amide compounds, oils and fats and higher fatty acids.

[0074]

[30] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[29] , wherein the oil phase comprises silicone.

[0075]

[31] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[30] , wherein the pre-emulsion is added to the second aqueous phase by jetting using a nozzle.

[0076]

[32] In the method for manufacturing an oil-in-water emulsion according to

[31] , the inner diameter of the nozzle is 0.01 mm or more and 20 mm or less.

[0077]

[33] In the method for manufacturing an oil-in-water emulsion according to

[31] , the inner diameter of the nozzle is 0.05 mm or more and 10 mm or less.

[0078]

[34] In the method for manufacturing an oil-in-water emulsion according to

[31] , the inner diameter of the nozzle is 0.1 mm or more and 1 mm or less.

[0079]

[35] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[34] , wherein the shear rate of the pre-emulsion when it is sprayed into the second aqueous phase is 0.25 s. -1 Above and 500,000 s -1 the following.

[0080]

[36] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[34] , wherein the shear rate of the pre-emulsion when it is sprayed into the second aqueous phase is 0.5 s⁻¹. -1 Above and 400,000 s -1 the following.

[0081]

[37] The method for manufacturing an oil-in-water emulsion according to any one of [1] to

[34] , wherein the shear rate of the pre-emulsion when it is sprayed into the second aqueous phase is 10,000 s. -1 Above and 300,000 s -1 the following.

[0082] Example

[0083] (Water-in-oil emulsion manufacturing apparatus)

[0084] Figure 1 This illustrates the structure of the oil-in-water emulsion manufacturing apparatus 10 used in this embodiment.

[0085] The oil-in-water emulsion manufacturing apparatus 10 includes a preparation tank 11 and a mating tank 12. A liquid supply pipe 13 extends from the bottom of the preparation tank 11 and connects to a circular jet nozzle 14 provided on the bottom side of the mating tank 12. A pump 15 for liquid delivery is provided on the liquid supply pipe 13.

[0086] (Manufacturing of oil-in-water emulsions)

[0087] <Example 1 and Comparative Example 1>

[0088] In Example 1, an oil-in-water preemulsion L1 with a mass ratio of oil phase to first aqueous phase of 0.5, obtained by dispersing the oil phase as shown in Table 1 in a first aqueous phase, was prepared and placed in a preparation tank 11. A second liquid phase L2 with the composition shown in Table 1 was prepared and placed in a mixing tank 12. The commercially available materials used for preparing the oil phase, the first aqueous phase, and the second aqueous phase L2 of the preemulsion L1 are as follows.

[0089] Silicone: Methylcyclopentasiloxane (TSF 405A, manufactured by Momentive)

[0090] Oil: Ethylhexyl methoxycinnamate (Uvinul MC80, manufactured by BASF Japan) Thickener: Locust bean gum (Soalocust A120, manufactured by Mitsubishi Chemical Foods Co., Ltd.)

[0091] Emulsion stabilizer: Polyvinyl alcohol (Gohsenol EG-05, manufactured by Mitsubishi Chemical Corporation)

[0092] Then, by operating pump 15 (diaphragm pump), the pre-emulsion L1 in preparation tank 11 is supplied to the second liquid phase L2 in mixing tank 12 via liquid supply pipe 13 under the conditions described in Table 1. At this time, the pre-emulsion L1 is ejected into the second liquid phase L2 from a jet nozzle 14 with an inner diameter of 0.35 mm, producing an oil-in-water emulsion. At this time, the pre-emulsion L1 is ejected from the jet nozzle 14 and diffused through the surface of the transparent wall of mixing tank 12, which can be visually confirmed.

[0093] In Comparative Example 1, the same operations as in Example 1 were performed except that an oil-in-water pre-emulsion with a mass ratio of 5.0 of oil phase to first water phase, prepared in the same manner as in Example 1, and a second liquid phase were used.

[0094] <Examples 2-10 and Comparative Example 2>

[0095] Except for changing the conditions to those described in Tables 1 to 5, perform the same operations as in Example 1.

[0096] <Examples 11 and 12>

[0097] In Example 11, an oil-in-water preemulsion L1 with a mass ratio of oil phase to first aqueous phase of 0.5, obtained by dispersing the oil phase as shown in Table 6 in a first aqueous phase, was prepared and placed in a preparation tank 11. A second liquid phase L2 with the composition shown in Table 6 was prepared and placed in a mixing tank 12. The commercially available materials used to prepare the oil phase, first aqueous phase, and second aqueous phase L2 of the preemulsion L1 are as described above.

[0098] Then, by operating pump 15 (rotary pump), the pre-emulsion L1 in preparation tank 11 is supplied to the second liquid phase L2 in mixing tank 12 via liquid supply pipe 13 under the conditions described in Table 6. At this time, the pre-emulsion L1 is ejected into the second liquid phase L2 from jet nozzle 14 with an inner diameter of 5 mm, producing an oil-in-water emulsion. At this time, the ejection and diffusion of pre-emulsion L1 from jet nozzle 14 can be visually confirmed from above mixing tank 12.

[0099] In Example 12, the same operations as in Example 11 are performed, except that the conditions are changed to those described in Table 6.

[0100] [Table 1]

[0101]

[0102] [Table 2]

[0103]

[0104] [Table 3]

[0105]

[0106] [Table 4]

[0107]

[0108] [Table 5]

[0109]

[0110] [Table 6]

[0111]

[0112] (Determination of the average particle size of the oil phase)

[0113] For the pre-emulsions L1 obtained in Examples 1-12 and Comparative Example 2, the average particle size of the oil phase (22°C) was measured using a laser diffraction / scattering particle size distribution measuring device (LA-960 S, manufactured by Horiba Manufacturing Co., Ltd.) as the area-based average particle size. Similarly, for the oil-in-water emulsions obtained in Examples 1-12 and Comparative Examples 1 and 2, the average particle size of the oil phase was measured (22°C). The average particle size of the oil phase in the oil-in-water emulsions obtained in Examples 1-12 was smaller than the inner diameter of the circular jet nozzle 14 used in each example. In Examples 1-12, it was possible to visually confirm that the pre-emulsion L1 was ejected and diffused from the jet nozzle 14. Therefore, in Examples 1-12, the state of the fluid ejected from the jet nozzle 14 was determined to be a jet state. The results are shown in Tables 1-6. It should be noted that in Comparative Example 1, the emulsified state of the pre-emulsion could not be maintained, so the measurement could not be performed.

[0114] (Viscosity measurement)

[0115] The viscosity of the preemulsion L1 and the second aqueous phase L2 obtained in Examples 1-12 and Comparative Example 2, respectively, was measured using a Type B viscometer (manufactured by BL Toki Sangyo Co., Ltd.) at 22°C under the following conditions. Similarly, the viscosity of the oil-in-water emulsions obtained in Examples 1-12 and Comparative Examples 1-2 was measured. The results are shown in Tables 1-6. The measurement temperature was the same as when the preemulsion L1 was added to the second liquid phase L2, which was room temperature (22°C).

[0116] When the viscosity is below 50 mPa·m, the rotor is No. 1, the rotation speed is 60 rpm, and the measurement time is 1 minute.

[0117] When the viscosity exceeds 50 mPa·m but is less than 20000 Pa·m, the rotor is No. 2, the rotation speed is 6 rpm, and the measurement time is 1 minute.

[0118] When the viscosity is above 20000 mPa·m, the rotor is No. 4, the rotation speed is 6 rpm, and the measurement time is 1 minute.

[0119] Industrial availability

[0120] This invention is useful in the technical field of methods for manufacturing oil-in-water emulsions.

Claims

1. A method for manufacturing an oil-in-water emulsion, wherein, The oil-in-water preemulsion obtained by dispersing the oil phase in the first aqueous phase is added to the second aqueous phase by a jet with a linear velocity of 5 m / s or higher.

2. The method for manufacturing an oil-in-water emulsion according to claim 1, wherein, The viscosity of the second aqueous phase at the temperature at which the preemulsion is added by jet is above 0.1 mPa·s and below 20,000 mPa·s.

3. The method for manufacturing an oil-in-water emulsion according to claim 1, wherein, The viscosity of the second aqueous phase at the temperature at which the preemulsion is added via jetting is above 1 mPa·s and below 10000 mPa·s.

4. The method for manufacturing an oil-in-water emulsion according to claim 1, wherein, The viscosity of the second aqueous phase at the temperature at which the preemulsion is added via jet is above 1 mPa·s and below 6000 mPa·s.

5. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, Using a mixing tank with a jet outlet, the pre-emulsion is jet-added from the jet outlet into the second aqueous phase accumulated in the mixing tank.

6. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The oil phase content in the preemulsion is at a mass ratio of 0.01 or more and 4 or less relative to the first aqueous phase content.

7. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The oil phase content in the preemulsion is at least 0.05 and less than 3 by mass relative to the first aqueous phase content.

8. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The oil phase content in the preemulsion is at a mass ratio of 0.1 or more and 3 or less relative to the first aqueous phase content.

9. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The average particle size of the oil phase in the preemulsion is less than 2000 μm.

10. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The average particle size of the oil phase in the preemulsion is less than 1000 μm.

11. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The average particle size of the oil phase in the preemulsion is greater than 1 μm and less than 500 μm.

12. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The average particle size of the oil phase in the preemulsion is greater than 10 μm and less than 100 μm.

13. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The viscosity of the preemulsion at the temperature at which it is added to the second aqueous phase by jet is greater than 1 mPa·s and less than 15000 mPa·s.

14. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The viscosity of the preemulsion at the temperature at which it is added to the second aqueous phase by jet is greater than 1 mPa·s and less than 10,000 mPa·s.

15. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The viscosity of the preemulsion at the temperature at which it is added to the second aqueous phase by jet is greater than 1 mPa·s and less than 6000 mPa·s.

16. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The viscosity of the preemulsion at the temperature at which it is added to the second aqueous phase by jet is above 10 mPa·s and below 6000 mPa·s.

17. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The viscosity of the second aqueous phase is lower than that of the preemulsion. Wherein, the viscosity of the second aqueous phase is the viscosity at the temperature at which the preemulsion is added by jetting, and the viscosity of the preemulsion is the viscosity at the temperature at which it is added to the second aqueous phase by jetting.

18. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The composition of the second aqueous phase is the same as that of the first aqueous phase of the preemulsion.

19. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The oil phase contains oiling agents and / or silicones.

20. The method for manufacturing an oil-in-water emulsion according to claim 19, wherein, The oil contains one or more of the following: alcohols, ester oils, hydrocarbon oils, dialkyl ether compounds, amine compounds, amide compounds, fats and oils, and higher fatty acids.

21. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The average particle size of the oil phase in the manufactured oil-in-water emulsion is less than 35 μm.

22. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The average particle size of the oil phase in the manufactured oil-in-water emulsion is less than 30 μm.

23. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The average particle size of the oil phase in the manufactured oil-in-water emulsion is greater than 1 μm and less than 20 μm.

24. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The pre-emulsion is added to the second aqueous phase using a nozzle.

25. The method for manufacturing an oil-in-water emulsion according to claim 24, wherein, The inner diameter of the nozzle is greater than 0.01 mm and less than 20 mm.

26. The method for manufacturing an oil-in-water emulsion according to claim 24, wherein, The inner diameter of the nozzle is greater than 0.05 mm and less than 10 mm.

27. The method for manufacturing an oil-in-water emulsion according to claim 24, wherein, The inner diameter of the nozzle is greater than 0.1 mm and less than 1 mm.

28. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The linear velocity of the preemulsion when it is added to the second aqueous phase by jet is above 10 m / s and below 100 m / s.

29. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The preemulsion has a shear rate of 0.25 kb / s when it is added to the second aqueous phase by jetting. -1 Above and 500,000 s -1 the following.

30. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The preemulsion has a shear rate of 0.5 s⁻¹ when it is added to the second aqueous phase by jetting. -1 Above and 400,000 s -1 the following.

31. The method for manufacturing an oil-in-water emulsion according to any one of claims 1 to 4, wherein, The preemulsion has a shear rate of 10,000 s⁻¹ when it is sprayed into the second aqueous phase. -1 Above and 300,000 s -1 the following.

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