JP6180254B2 - Hydrogel particles - Google Patents

Description

  The present invention relates to hydrogel particles, a production method thereof, and a whitening cosmetic using the same.

  It is known to add a whitening agent to cosmetics.

  For example, Patent Document 1 discloses that a whitening agent is blended with an ultraviolet protective cosmetic. Patent Document 2 discloses that whitening agent-containing microcapsules are blended in cosmetics.

JP 2011-148771 A Japanese Patent Laid-Open No. 2005-2012

  By the way, in the hydrogel particles in which the dispersed phase is dispersed in the continuous phase of the non-crosslinked hydrogel, when the crystalline whitening agent is included in the dispersed phase, the crystalline whitening agent leaks out of the hydrogel particles, and the crystals are May precipitate. And in the cosmetics in which such hydrogel particles are blended, the touch at the time of use becomes inferior.

  The subject of this invention is suppressing the precipitation of the crystal | crystallization of the crystalline whitening agent outside a hydrogel particle.

  The hydrogel particles of the present invention comprise a continuous phase of a non-crosslinked hydrogel and a dispersed phase dispersed in the continuous phase, and the dispersed phase is a solid containing fatty acid glyceride and a higher alcohol having 14 to 22 carbon atoms. Contains fat and a crystalline whitening agent having a biphenyl skeleton.

  The whitening cosmetic composition of the present invention contains the hydrogel particles of the present invention.

  The method for producing hydrogel particles of the present invention drops a solid fat containing fatty acid glyceride and a higher alcohol having 14 to 22 carbon atoms, a crystalline whitening agent having a biphenyl skeleton, a gel-forming agent, and a dispersion containing water. It is cooled and solidified as droplets by the method, spraying method or stirring method.

  According to the present invention, a hydrogel particle of a crystalline whitening agent having a biphenyl skeleton contained in a dispersed phase because the dispersed phase contains a solid fat containing a fatty acid glyceride and a higher alcohol having 14 to 22 carbon atoms. Leakage from the liquid can be suppressed, so that the precipitation of the crystalline whitening agent crystal outside the hydrogel particles can be suppressed.

  Hereinafter, embodiments will be described in detail.

[Hydrogel particles]
The hydrogel particles according to this embodiment include a continuous phase of a non-crosslinked hydrogel and a dispersed phase dispersed in the continuous phase. The dispersed phase includes solid fat A containing fatty acid glyceride A1 and higher alcohol A2 having 14 to 22 carbon atoms (hereinafter abbreviated as “higher alcohol A2”), and crystalline whitening agent B (hereinafter “crystal” A whitening agent B ”). The hydrogel particles according to the present embodiment are used, for example, by blending in cosmetics, mainly whitening cosmetics.

  According to the hydrogel particles according to the present embodiment, leakage of the crystalline whitening agent B contained in the dispersed phase from the hydrogel particles can be suppressed by having the above-described configuration. Precipitation of the crystal of the whitening agent B can be suppressed. Therefore, for example, even when the hydrogel particles according to the present embodiment are blended in a cosmetic, the precipitation of the crystal whitening agent B in the cosmetic is suppressed, and therefore it is stably stored for a long period of time. Can do. The crystal whitening agent B has the effect of suppressing the precipitation of crystals by forming a film with fatty acid glyceride A1 and higher alcohol A2 on the surface layer of the dispersed phase, thereby suppressing leakage of the crystalline whitening agent B from the dispersed phase. It is speculated that it may be played.

  In addition, although it is described in patent document 1 that you may mix | blend a whitening agent with hydrogel particle, there is no description about a crystalline whitening agent, and it is not disclosed regarding the subject. Patent Document 2 describes a whitening agent-encapsulating microcapsule, which is obtained by atomizing a whitening agent into a microcapsule and not containing an oil in the microcapsule.

  Here, “hydrogel particles” in the present application are one or more particles in which a dispersed phase is dispersed in a continuous phase of a non-crosslinked hydrogel. In addition, the “non-crosslinked hydrogel” in the present application is a gel obtained from a gel-forming agent using water as a solvent, and gelation is caused by the thermoreversibility of the sol-gel. In addition, the structure in which the dispersed phase is dispersed in the continuous phase in the hydrogel particles can be confirmed by, for example, photographic observation analysis using a frozen cleaving SEM.

  From the viewpoint of productivity, the volume-based average particle size of the hydrogel particles is preferably 10 μm or more, more preferably 20 μm or more, and further preferably 30 μm or more. Hereinafter, it is also simply referred to as “use feeling”) and from the viewpoint of excellent appearance, it is preferably 10,000 μm or less, more preferably 1000 μm or less, and even more preferably 250 μm or less. The volume-based average particle diameter of the hydrogel particles can be measured by a laser diffraction scattering method (for example, model number: LA-920 manufactured by Horiba, Ltd.) or a sieving method. The laser diffraction / scattering method is preferably used for measuring particles of 1000 μm or less, and the screening method is preferably used for measuring particles exceeding 1000 μm.

  The shape of the hydrogel particles is not particularly limited, but is preferably a shape of a rotating body formed of a curved surface. Here, the “rotary body constituted by a curved surface” means a closed figure constituted by a virtual axis and a continuous curve, rotated by the virtual axis, and has a shape such as a triangular pyramid or a cylinder. Is not included. The shape of the hydrogel particles is more preferably spherical or elliptical from the viewpoint of aesthetics when blended in a cosmetic.

(Continuous phase)
The continuous phase is composed of a non-crosslinked hydrogel and contains a gel forming agent and water.

  The dissolution temperature of the non-crosslinked hydrogel is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and still more preferably 75 ° C. or higher, from the viewpoint of blending in cosmetics, and preferably from the viewpoint of productivity. It is 98 degrees C or less, More preferably, it is 95 degrees C or less. In addition, the gelation temperature of the non-crosslinked hydrogel is preferably 20 ° C. or higher, more preferably 25 ° C. or higher, further preferably 30 ° C. or higher, from the viewpoint of productivity. 50 ° C. or lower, more preferably 45 ° C. or lower.

Jelly strength of non-crosslinked hydrogel, from the viewpoint of feel during use when applied to cosmetics, preferably 147kPa (1500g / cm ²⁾ or less, more preferably 19.6kPa (200g / ^cm 2) ~ 127 kPa (1300 g / cm ² ). The jelly strength can be determined by the Nissho water method. Specifically, the jelly strength is determined by preparing a 1.5% by weight aqueous solution of a gel forming agent, and allowing the aqueous solution to stand for 15 hours at 20 ° C. to solidify the gel. The maximum mass (g) per 1 cm ² of the surface area when the gel withstands the load at 20 ° C. for 20 seconds at 20 ° C. can be obtained.

  The content of the continuous phase in the hydrogel particles is preferably 30% by mass or more, more preferably 40% by mass or more, and still more preferably 50% by mass, from the viewpoint of ease of spreading on the skin when applied to cosmetics and the like. % Or more, more preferably 60% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, from the viewpoint of suppressing disintegration at the time of blending hydrogel particles into a cosmetic or the like. More preferably, it is 80 mass% or less.

  Examples of the gel forming agent include agar, carrageenan, gelatin and the like. Of these, agar is preferred from the viewpoint of storage stability of the hydrogel particles. The gel forming agent may contain only a single species or a plurality of species.

  The content of the gel-forming agent in the continuous phase is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and more preferably 0.5% by mass or more from the viewpoint of preventing the hydrogel particles from collapsing when blended with cosmetics. Preferably, it is 1.5% by mass or more, and preferably 8% by mass or less, more preferably 5% by mass or less, and still more preferably, from the viewpoint of good feel when used when applied to cosmetics and the like. Is 3% by mass or less.

  The content of the gel forming agent in the hydrogel particles is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, from the viewpoint of preventing the hydrogel particles from collapsing when blended with cosmetics. More preferably, it is 1% by mass or more, and from the viewpoint of good feel when used when applied to cosmetics, etc., preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably. 2% by mass or less.

(Dispersed phase)
The dispersed phase contains solid fat A and crystalline whitening agent B. Further, the dispersed phase may further contain liquid oil C. In this case, in the dispersed phase, the solid fat A and the liquid oil C constitute an oil and fat component.

  Here, “solid fat A” in the present application refers to an oil having a melting point of 35 ° C. or higher. Further, “liquid oil C” in the present application refers to an oil having a melting point of less than 35 ° C. In addition, these melting | fusing points can be measured by the differential scanning calorimetry (DSC: Differential Scanning Calorimentry).

  The content of the dispersed phase in the hydrogel particles is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 15% by mass, from the viewpoint of suppressing the collapse of the hydrogel particles when blended with cosmetics. % Or more, more preferably 20% by mass or more, still more preferably 25% by mass or more, and preferably 70% by mass or less from the viewpoint of easy extension on the skin when applied to cosmetics and the like. More preferably, it is 60 mass% or less, More preferably, it is 50 mass% or less, More preferably, it is 40 mass% or less, More preferably, it is 35 mass% or less.

  The volume-based average particle size of the dispersed phase is preferably 1/10 or less of the volume-based average particle size of the hydrogel particles. Specifically, the volume-based average particle diameter of the dispersed phase can be smoothly extended on the skin when applied to cosmetics, etc., and the dispersion phase leakage suppression from hydrogel particles, cosmetics, etc. From the viewpoint of good conformability to the skin when applied to the skin, it is preferably 0.01 to 100 μm, more preferably 0.5 to 20 μm. The volume-based average particle size of the dispersed phase is a laser diffraction / scattering using a laser diffraction / scattering particle size distribution measuring device (for example, model number: LA-920, manufactured by Horiba, Ltd.) in the state of the dispersion before particle formation. It can be measured by the method.

<Solid fat A>
The solid fat A is an oil having a melting point of 35 ° C. or higher, and includes fatty acid glyceride A1 and higher alcohol A2. The solid fat A may contain other, for example, higher alcohols having 14 to 22 carbon atoms, solid paraffin, or the like, as long as the effect of suppressing the leakage of the crystalline whitening agent B from the hydrogel particles is not inhibited. Good.

  The content of the solid fat A in the dispersed phase is preferably 4% by mass or more, more preferably 6% by mass or more, and still more preferably 10% by mass from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles. From the viewpoint of easiness of spreading on the skin when applied to cosmetics, etc., preferably 50% by mass or less, more preferably 40% by mass or less, and more preferably 11% by mass or more. Preferably it is 34 mass% or less, More preferably, it is 30 mass% or less, More preferably, it is 29 mass% or less.

  The total content of the solid fat A in the hydrogel particles is preferably 1% by mass or more, more preferably 2% by mass or more, and further preferably 2 from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles. 0.5% by mass or more, more preferably 3% by mass or more, and preferably 30% by mass or less, more preferably from the viewpoint of ease of spreading on the skin when applied to cosmetics and the like. It is 25 mass% or less, More preferably, it is 20 mass% or less, More preferably, it is 15 mass% or less, More preferably, it is 10 mass% or less.

-Fatty acid glyceride A1-
The fatty acid glyceride A1 preferably contains a compound represented by the following general formula (I).

R ₁ COOCH ₂ (CHX) CH ₂ Y (I)
(In the formula, X and Y each independently represent OH or OCOR ₂ , and R ₁ and R ₂ each independently represent a saturated hydrocarbon group having 13 to 21 carbon atoms, preferably 13 to 13 carbon atoms. 21 represents a straight-chain saturated hydrocarbon group)
The fatty acid glyceride A1 of the general formula (I) may include a fatty acid triglyceride in which both X and Y are OCOR ₂ , but from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles, X and It is preferable to include at least one of fatty acid monoglycerides in which all of Y is OH and fatty acid diglycerides in which one of X and Y is OH and the other is OCOR ₂ , and more preferably includes fatty acid monoglycerides. From the same viewpoint, in the fatty acid glyceride A1 of the general formula (I), R ₁ and R ₂ are preferably each independently a saturated hydrocarbon group having 16 or 18 carbon atoms. It is more preferably a saturated hydrocarbon group. The saturated hydrocarbon group may be either linear or branched, but is preferably linear.

  Specific examples of the fatty acid monoglyceride include palmitic acid monoglyceride, stearic acid monoglyceride, and behenic acid monoglyceride. Specific fatty acid diglycerides include, for example, palmitic acid diglyceride, stearic acid diglyceride, behenic acid diglyceride, and the like, and fatty acid glyceride A1 includes only a single species or a plurality of species. Or either. Among these, from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles, one or more selected from the group consisting of stearic acid monoglyceride and stearic acid diglyceride are preferable, and the combination of both is more preferable.

  The content of the fatty acid glyceride A1 in the dispersed phase is preferably 2% by mass or more, more preferably 3% by mass or more, and further preferably 5% by mass from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles. Above, more preferably 6% by mass or more, and from the viewpoint of ease of spreading on the skin when applied to cosmetics and the like, preferably 25% by mass or less, more preferably 20% by mass or less, further Preferably it is 17 mass% or less, More preferably, it is 15 mass% or less.

  The total content of fatty acid glyceride A1 in the hydrogel particles is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles. More preferably, it is 1% by mass or more, still more preferably 1.5% by mass or more, and preferably 20% by mass or less from the viewpoint of easy extension on the skin when applied to cosmetics and the like. More preferably, it is 10 mass% or less, More preferably, it is 5 mass% or less.

-Higher alcohol A2-
The higher alcohol A2 is a chain alcohol having 14 to 22 carbon atoms contained in the molecule. From the viewpoint of suppressing the leakage of the crystalline whitening agent B from the hydrogel particles, the higher alcohol A2 preferably has 16 to 22 carbon atoms, more preferably 16 to 18 carbon atoms in the molecule. The higher alcohol A2 is preferably a linear or branched saturated monohydric alcohol, and more preferably linear.

  Examples of the higher alcohol A2 include cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, 2-octyldodecanol, and arachidyl alcohol. The higher alcohol A2 preferably contains one or more selected from the group consisting of these higher alcohols, more preferably one or two selected from the group consisting of cetyl alcohol, stearyl alcohol, and behenyl alcohol. More preferably, cetyl alcohol and / or stearyl alcohol are included.

  The higher alcohol A2 may include only a single species or a plurality of species. In the latter case, cetostearyl alcohol in which cetyl alcohol and stearyl alcohol are mixed is preferable from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles. The mixed mass ratio of cetostearyl alcohol (cetyl alcohol / stearyl alcohol) is preferably 0.33 or more, more preferably 0.5 or more, still more preferably 1 or more, and preferably 3 or less, more preferably 2 Hereinafter, it is more preferably 1.5 or less.

  The content of the higher alcohol A2 in the dispersed phase is preferably 2% by mass or more, more preferably 3% by mass or more, and further preferably 5% by mass from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles. Above, more preferably 6% by mass or more, and from the viewpoint of ease of spreading on the skin when applied to cosmetics and the like, preferably 25% by mass or less, more preferably 20% by mass or less, further Preferably it is 17 mass% or less, More preferably, it is 15 mass% or less.

  The total content of the fatty acid glyceride A1 and the higher alcohol A2 in the dispersed phase is preferably 4% by mass or more, more preferably 6% by mass or more, from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles. It is preferably 10% by mass or more, more preferably 11% by mass or more, and preferably 50% by mass or less, more preferably 40% from the viewpoint of ease of spreading on the skin when applied to cosmetics and the like. It is not more than mass%, more preferably not more than 34 mass%, still more preferably not more than 30 mass%, still more preferably not more than 29 mass%.

  The mass ratio of the content of fatty acid glyceride A1 to the content of higher alcohol A2 in the dispersed phase (fatty acid glyceride A1 / higher alcohol A2) is preferably from the viewpoint of suppressing leakage of crystalline whitening agent B from the hydrogel particles. It is 0.2 or more, more preferably 0.3 or more, further preferably 0.4 or more, and from the same viewpoint, it is preferably 4 or less, more preferably 3 or less, still more preferably 2.5 or less.

  The total content of higher alcohol A2 in the hydrogel particles is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles. More preferably 1% by mass or more, still more preferably 1.5% by mass or more, and from the viewpoint of ease of spreading on the skin when applied to cosmetics, etc., preferably 20% by mass or less, more Preferably it is 15 mass% or less, More preferably, it is 10 mass% or less, More preferably, it is 5 mass% or less.

  The total total content of fatty acid glyceride A1 and higher alcohol A2 in the hydrogel particles is preferably 1% by mass or more, more preferably 2% by mass or more from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles. More preferably, it is 3% by mass or more, and from the viewpoint of ease of spreading on the skin when applied to cosmetics, etc., it is preferably 30% by mass or less, more preferably 25% by mass or less, and still more preferably. It is 20 mass% or less, More preferably, it is 15 mass% or less, More preferably, it is 10 mass% or less.

<Crystalline whitening agent B>
“Crystalline whitening agent B” in the present application refers to a crystalline compound having a biphenyl skeleton that exhibits a tyrosinase activity inhibitory effect and / or a melanin production inhibitory effect. The crystallinity can be confirmed by having a peak by X-ray diffraction. As the crystalline whitening agent B, magnolignan is preferable.

  The crystalline whitening agent B preferably contains a biphenyl compound represented by the following general formula (1).

In the crystalline whitening agent B represented by the general formula (1), R ₃ and R ₄ are each independently a hydrogen atom or a straight chain having 1 to 10 carbon atoms from the viewpoint of whitening effect and stability. It is preferable to include a biphenyl compound that is an alkyl group, more preferably a biphenyl compound that is a linear alkyl group having 1 to 8 carbon atoms, and biphenyl that is a linear alkyl group having 1 to 5 carbon atoms. More preferably, it comprises a compound. Examples of R ₃ and R ₄ include H, CH ₃ , C ₂ H ₅ , C ₃ H ₇ , C ₄ H ₉ , C ₅ H ₁₁ , C ₆ H ₁₃ , C ₇ H ₁₅ , C ₈ H _{17 and the} like. Is mentioned. The crystalline whitening agent B of the biphenyl compound represented by the general formula (1) is 2,2′-dihydroxy-5,5′-di-n-propyl in which each of R ₃ and R ₄ is C ₃ H ₇ It is even more preferable that biphenyl (magnolignan) is contained.

  The crystalline whitening agent B preferably contains a biphenyl compound represented by the following general formula (2).

In the crystalline whitening agent B represented by the general formula (2), R ₅ and R ₆ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, or 1 to 10 carbon atoms. A linear or branched hydroxyalkyl group, an aldehyde group, or a biphenyl compound that is an acetyl group, preferably a linear or branched alkyl group having 1 to 5 carbon atoms, It is more preferable to include a biphenyl compound that is a 5 linear or branched hydroxyalkyl group, aldehyde group, or acetyl group, and a biphenyl compound that is a linear alkyl group having 1 to 3 carbon atoms. Is more preferable. Examples of R ₅ and R ₆ include CH ₃ , C ₂ H ₅ , C ₃ H ₇ , CH ₂ OH, C ₃ H ₆ OH, CHO, COCH ₃ , CH ₂ CH═CH _{2, and the} like.

  Furthermore, the crystalline whitening agent B may contain a biphenyl compound represented by the following general formula (3). Further, the crystalline whitening agent B may include an acylated biphenyl compound represented by the following general formula (4).

  The crystalline whitening agent B may contain only a single species or a plurality of species. The crystalline whitening agent B can be obtained by synthesis by a conventional method, or can be obtained by hydrogenating a substance extracted from a plant or the like.

  The content of the crystalline whitening agent B in the dispersed phase is preferably 3% by mass or more, more preferably 5% by mass or more, still more preferably 8% by mass or more, from the viewpoint of the whitening effect. From the viewpoint of suppressing the leakage of the crystalline whitening agent B and the ease of spreading on the skin when applied to cosmetics and the like, it is preferably 25% by mass or less, more preferably 20% by mass or less, and still more preferably. It is 15 mass% or less, More preferably, it is 13 mass% or less.

  From the viewpoint of the whitening effect, the mass ratio of the content of the crystalline whitening agent B to the total content of the fatty acid glyceride A1 and the higher alcohol A2 in the dispersed phase (crystalline whitening agent B / (fatty acid glyceride A1 + higher alcohol A2)) Preferably it is 0.1 or more, more preferably 0.2 or more, further preferably 0.3 or more, and preferably 5 or less from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles. More preferably, it is 4 or less, More preferably, it is 3 or less, More preferably, it is 2 or less, More preferably, it is 1 or less.

  From the viewpoint of the whitening effect, the total content of the crystalline whitening agent B in the hydrogel particles is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and even more. Preferably, it is 2% by mass or more, and from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles, it is preferably 10% by mass or less, more preferably 7% by mass or less, and further preferably 5% by mass. Hereinafter, it is more preferably 4% by mass or less.

  It is preferable that the crystalline whitening agent B is not crystallized in the hydrogel particles from the viewpoint of usability.

<Liquid oil C>
The liquid oil C is an oil having a melting point of less than 35 ° C., and from the viewpoint of stably blending the poorly soluble crystalline whitening agent B and ease of spreading on the skin when applied to cosmetics and the like, It is preferable that the aliphatic dicarboxylic acid ester represented by the general formula (i) is included.

  The number of carbon atoms contained in the molecule of the aliphatic dicarboxylic acid constituting the aliphatic dicarboxylic acid ester is preferably 4 to 12, more preferably 6 to 12, still more preferably 8 to 12, and still more preferably 8 to 10. is there. Examples of the aliphatic dicarboxylic acid include adipic acid, suberic acid, azelaic acid, sebacic acid, 1,10-decanedicarboxylic acid, and the like.

  The alcohol constituting the aliphatic dicarboxylic acid ester is preferably a linear or branched alcohol having 1 to 4 carbon atoms. Examples of such alcohol include methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-1-propanol, and 2-methyl-2-propanol.

  Specifically, examples of the aliphatic dicarboxylic acid ester include diisopropyl sebacate.

  The content of the aliphatic dicarboxylic acid ester in the liquid oil C is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 70% by mass from the viewpoint of stably blending the poorly soluble crystalline whitening agent B. % Or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and most preferably 100% by mass.

  In addition, the liquid oil C may contain a propylene glycol fatty acid ester represented by the following general formula (ii). In addition, the liquid oil C may contain a propylene glycol fatty acid ester represented by the following general formula (iii).

  The liquid oil C may include only a single species or a plurality of species.

  The content of the liquid oil C in the dispersed phase is preferably 30% by mass from the viewpoint of stably blending the poorly soluble crystalline whitening agent B and the ease of spreading on the skin when applied to cosmetics and the like. Or more, more preferably 40% by mass or more, further preferably 50% by mass or more, still more preferably 60% by mass or more, and preferably from the viewpoint of suppressing leakage of the crystalline whitening agent B from the hydrogel particles. Is 90% by mass or less, more preferably 85% by mass or less, still more preferably 80% by mass or less, and still more preferably 78% by mass or less.

  Mass ratio of content of crystalline whitening agent B to content of liquid oil C in dispersed phase (crystalline whitening agent B / liquid oil C), preferably crystallinity with respect to content of said aliphatic dicarboxylic acid ester in dispersed phase From the viewpoint of enhancing the whitening effect, the mass ratio of the content of whitening agent B (crystalline whitening agent B / aliphatic dicarboxylic acid ester) is preferably 0.03 or more, more preferably 0.05 or more, and even more preferably 0. From the viewpoint of stably blending the poorly soluble crystalline whitening agent B and the ease of spreading on the skin when applied to cosmetics, etc., preferably 0.5 or less, more Preferably it is 0.3 or less, More preferably, it is 0.2 or less.

  The content of the fat and oil component consisting of the solid fat A and the liquid oil C in the dispersed phase is easy to extend on the skin when applied to cosmetics and the like in terms of stably blending the poorly soluble crystalline whitening agent B. From a viewpoint, Preferably it is 60 mass% or more, More preferably, it is 70 mass% or more, More preferably, it is 80 mass% or more, From a viewpoint of mix | blending the crystalline whitening agent B, Preferably it is 98 mass% or less, More preferably Is 95% by mass or less, more preferably 93% by mass or less.

  The total content of the liquid oil C in the hydrogel particles is preferably 5 from the viewpoint of stably blending the poorly soluble crystalline whitening agent B and the ease of spreading on the skin when applied to cosmetics and the like. % By weight or more, more preferably 10% by weight or more, more preferably 15% by weight or more, and still more preferably 20% by weight or more. Further, from the viewpoint of excellent usability and the crystalline whitening agent B from the hydrogel particles. From the viewpoint of suppressing leakage, it is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and still more preferably 25% by mass or less.

  The total content of fat and oil components composed of solid fat A and liquid oil C in the hydrogel particles is easy to extend on the skin when applied to cosmetics and the like in view of stably blending the poorly soluble crystalline whitening agent B From the viewpoint of thickness, it is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and still more preferably 24% by mass or more. From the viewpoint of suppressing leakage of the crystalline whitening agent B from the gel particles, it is preferably 40% by mass or less, more preferably 35% by mass or less, and further preferably 31% by mass or less.

(Optional component)
The continuous phase is composed of water-soluble organic compounds such as sugars, polyhydric alcohols, water-soluble polymer compounds and water-soluble fragrances described in JP-A-2000-126586, in addition to the gelling agent for non-crosslinked hydrogel and water. You may contain a component.

  Each of the continuous phase and the dispersed phase may contain components such as an emulsifying dispersant, a colorant, and a preservative described later. Examples of the preservative include methyl paraoxybenzoate, isopropylmethylphenol, dehydroacetic acid and salts thereof.

  In addition, each of the continuous phase and the dispersed phase may contain components such as a humectant, an antiperspirant, an antibacterial agent, a bactericidal agent, and a powder generally applied to cosmetics.

  It is preferable that the hydrogel particle which concerns on this embodiment is a thing obtained by the manufacturing method demonstrated below.

[Method for producing hydrogel particles]
Hereinafter, the manufacturing method of the hydrogel particle which concerns on this embodiment is demonstrated.

  The method for producing hydrogel particles according to this embodiment comprises a solid fat containing fatty acid glyceride and a higher alcohol having 14 to 22 carbon atoms, a crystalline whitening agent having a biphenyl skeleton, a gel forming agent, and a dispersion containing water. A method of cooling and solidifying into droplets by a dropping method, a spraying method, or a stirring method is preferable.

(Preparation of dispersion)
First, as the dispersed phase component liquid, a mixed liquid in which the solid fat A containing the fatty acid glyceride A1 and the higher alcohol A2 and the crystalline whitening agent B are heated and mixed and sufficiently dissolved is prepared. When the dispersed phase contains liquid oil C, liquid oil C is included in the dispersed phase component liquid. In addition, as a continuous phase component liquid, a gel forming agent and ion-exchanged water are mixed and heated to a temperature equal to or higher than the melting temperature to prepare a mixed liquid that is sufficiently dissolved.

  Then, the dispersion phase component liquid and the continuous phase component liquid are mixed at a temperature equal to or higher than the gelation temperature to prepare an oil-in-water dispersion. Here, the method for preparing the dispersion is not particularly limited, and known techniques using various stirrers, dispersers and the like can be applied.

  An emulsifying dispersant is preferably added to the dispersed phase component liquid and / or the continuous phase component liquid at the time of preparation and / or after the preparation, and the emulsifying dispersant may be added to the continuous phase component liquid at the time of preparation. More preferred. Further, an emulsifying dispersant may be added during and / or after mixing of the dispersed phase component liquid and the continuous phase component liquid.

  Examples of the emulsifying dispersant include a polymer emulsifying dispersant, a nonionic surfactant, an anionic surfactant, a cationic surfactant, and an amphoteric surfactant. The emulsifying dispersant may be either a single type or a plurality of types.

(Particulate dispersion)
Subsequently, after preparing the dispersion, hydrogel particles are produced by cooling and solidifying the dispersion into droplets by a general dropping method, spraying method, or stirring method.

  The dropping method uses the property that a dispersion liquid is discharged from a hole and the discharged dispersion liquid becomes a droplet by its surface tension or interfacial tension, and the droplet is cooled in a gas phase such as air or in a liquid phase. This is a method for producing hydrogel particles by solidification. From the viewpoint of producing hydrogel particles having a uniform particle size, it is preferable to vibrate the dispersion discharged from the holes.

  The spraying method uses a spray nozzle, sprays the dispersion liquid from the spray nozzle into the gas phase, forms droplets by the surface tension, and cools and solidifies the droplets in the gas phase to produce hydrogel particles. It is.

  From the viewpoint of productivity, the temperature of the gas phase or liquid phase when cooled and solidified by the dropping method, and the temperature of the gas phase when cooled and solidified by the spray method are preferably 0 ° C. or more, more preferably 5 ° C. From the viewpoint of cooling and solidification, it is preferably 35 ° C. or lower, more preferably 30 ° C. or lower.

  In the stirring method, the dispersion liquid is put into a liquid having properties that do not substantially mix with the dispersion liquid and adjusted to a temperature equal to or higher than the gelling temperature, and the dispersion liquid is atomized by a shearing force by stirring, and the interfacial tension is applied. By utilizing the property of becoming droplets, hydrogel particles are produced by cooling and solidifying the droplets in a liquid that does not substantially mix with the dispersion.

  In any case of the dropping method, the spraying method, and the stirring method, the temperature of the dispersion liquid at the time of discharge, spraying, or charging can be easily manufactured from the viewpoint of being able to easily produce spherical particles having an excellent appearance. Preferably the gelling temperature or higher, more preferably the gelling temperature + 10 ° C or higher, more preferably the gelling temperature + 20 ° C or higher, and from the viewpoint of productivity, preferably 100 ° C or lower, more preferably 95 ° C or lower, More preferably, it is 90 degrees C or less.

  In addition, the dropping method and the spraying method are preferable from the viewpoint of suppressing leakage of the oil and fat component from the hydrogel particles, and the spraying method is more preferable from the viewpoint of productivity.

  The hydrogel particles produced as described above may be further refined by pulverization or the like as necessary.

[Whitening cosmetics]
A whitening cosmetic having a whitening effect can be obtained by blending the hydrogel particles according to the present embodiment. When used in an emulsion, it can be applied to both w / o type and o / w type cosmetics. From the viewpoint of the dispersion stability of hydrogel particles, o / w type cosmetics can be used. It is preferable to use it. The hydrogel particles according to the present embodiment can be applied to cosmetics mainly composed of a water-soluble solvent such as skin lotion.

  The content of the hydrogel particles in the whitening cosmetic is preferably 1% by mass or more, more preferably 3% by mass or more, and further preferably 5% by mass or more, from the viewpoint of expressing the whitening effect. From the viewpoint of the dispersion stability, it is preferably 80% by mass or less, more preferably 60% by mass or less, and still more preferably 50% by mass or less.

  The content of the crystalline whitening agent B in the whitening cosmetic, although the optimum amount varies depending on the substance, from the viewpoint of expressing the whitening effect, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, More preferably, it is 0.3% by mass or more, and from the viewpoint of the stability of the crystalline whitening agent B, it is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 3% by mass or less. .

  In the whitening cosmetic, in addition to the hydrogel particles containing the crystalline whitening agent B, an ultraviolet absorber, a polymer emulsifying dispersant, a bactericidal agent, as long as the inhibitory effect on leakage of the crystalline whitening agent B from the hydrogel particles is not inhibited. An agent, an antiperspirant, a moisturizer, a refreshing agent, a fragrance, a colorant, and the like may be blended.

  The following configuration is further disclosed with respect to the embodiment described above.

  <1> A continuous phase of a non-crosslinked hydrogel and a dispersed phase dispersed in the continuous phase, wherein the dispersed phase includes a solid fat containing fatty acid glyceride and a higher alcohol having 14 to 22 carbon atoms, and a biphenyl skeleton. Hydrogel particles containing a crystalline whitening agent having

  <2> The hydrogel particles according to <1>, wherein the higher alcohol has a carbon number of preferably 16 to 22, more preferably 16 to 18.

  <3> The hydrogel particles according to <1> or <2>, wherein the higher alcohol is preferably a linear or branched saturated monohydric alcohol.

  <4> The higher alcohol preferably contains one or more selected from the group consisting of cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, 2-octyldodecanol, and arachidyl alcohol, more preferably One or more selected from the group consisting of cetyl alcohol, stearyl alcohol, and behenyl alcohol, more preferably cetyl alcohol and / or stearyl alcohol, any one of <1> to <3> above Hydrogel particles.

  <5> The content of the higher alcohol in the dispersed phase is preferably 2% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, and still more preferably 6% by mass or more. The hydro hydride according to any one of <1> to <4>, preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 17% by mass or less, and still more preferably 15% by mass or less. Gel particles.

  <6> The mass ratio of the fatty acid glyceride content to the higher alcohol content in the dispersed phase (fatty acid glyceride / higher alcohol) is preferably 0.2 or more, more preferably 0.3 or more, more preferably 0. 4 or more, and from the same viewpoint, the hydrogel according to any one of <1> to <5>, preferably 4 or less, more preferably 3 or less, and still more preferably 2.5 or less. particle.

  <7> The mass ratio of the content of the crystalline whitening agent to the total content of the fatty acid glyceride and the higher alcohol in the dispersed phase (crystalline whitening agent / (fatty acid glyceride + higher alcohol)) is preferably 0. .1 or more, more preferably 0.2 or more, still more preferably 0.3 or more, and preferably 5 or less, more preferably 4 or less, still more preferably 3 or less, still more preferably 2 or less, and still more The hydrogel particle according to any one of <1> to <6>, which is preferably 1 or less.

  <8> The hydrogel particles according to any one of claims 1 to 7, wherein the fatty acid glyceride includes a compound represented by the following general formula (I).

R ₁ COOCH ₂ (CHX) CH ₂ Y (I)
(Wherein, X and Y each independently represent OH or OCOR ₂ , and R ₁ and R ₂ each independently represent a saturated hydrocarbon group having 13 to 21 carbon atoms)
<9> The fatty acid glyceride of the general formula (I) is preferably a fatty acid monoglyceride in which both X and Y are OH, and a fatty acid diglyceride in which one of X and Y is OH and the other is OCOR ₂ The hydrogel particles according to <8>, including at least one, more preferably fatty acid monoglyceride.

<10> In the fatty acid glyceride of the general formula (I), R ₁ and R ₂ are each independently preferably a saturated hydrocarbon group having 16 or 18 carbon atoms, more preferably 16 or 18 carbon atoms. The hydrogel particle according to <8> or <9>, which is a linear saturated hydrocarbon group.

  <11> The fatty acid glyceride represented by the general formula (I) is preferably one selected from the group consisting of palmitic acid monoglyceride, stearic acid monoglyceride, behenic acid monoglyceride, palmitic acid diglyceride, stearic acid diglyceride, and behenic acid diglyceride. <8> to <10, comprising two or more, more preferably one or more selected from the group consisting of stearic acid monoglyceride and stearic acid diglyceride, and still more preferably a combination of stearic acid monoglyceride and stearic acid diglyceride. > The hydrogel particle in any one of.

  <12> The hydrogel particles according to any one of <1> to <11>, wherein the crystalline whitening agent includes a biphenyl compound represented by the following general formula (1).

<13> In the crystalline whitening agent B represented by the general formula (1), R ₃ and R ₄ are preferably each independently a hydrogen atom or a linear alkyl group having 1 to 10 carbon atoms. A biphenyl compound, more preferably a biphenyl compound which is a linear alkyl group having 1 to 8 carbon atoms, more preferably a biphenyl compound which is a linear alkyl group having 1 to 5 carbon atoms, and still more preferably C _3. It is H ₇ containing 2,2'-dihydroxy-5,5'-di -n- propyl biphenyl, hydrogel particles according to <12>.

  <14> The hydrogel particles according to any one of <1> to <13>, wherein the dispersed phase further contains liquid oil.

  <15> The hydrogel particles according to <14>, wherein the liquid oil contains an aliphatic dicarboxylic acid ester represented by the following general formula (i).

  <16> The number of carbon atoms contained in the molecule of the aliphatic dicarboxylic acid constituting the aliphatic dicarboxylic acid ester of the liquid oil is preferably 4 to 12, more preferably 6 to 12, still more preferably 8 to 12, The hydrogel particles according to <15>, further preferably 8 to 10.

  <17> The <15>, wherein the aliphatic dicarboxylic acid includes one or more selected from the group consisting of adipic acid, suberic acid, azelaic acid, sebacic acid, and 1,10-decanedicarboxylic acid. Or the hydrogel particle as described in <16>.

  <18> The hydrogel particles according to <15> or <16>, wherein the liquid oil contains diisopropyl sebacate.

  <19> The content of the aliphatic dicarboxylic acid ester in the liquid oil is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, still more preferably 80% by mass or more, The hydrogel particles according to any one of <15> to <18>, more preferably 90% by mass or more, and most preferably 100% by mass.

  <20> The content of the liquid oil in the dispersed phase is preferably 30% by mass or more, more preferably 40% by mass or more, still more preferably 50% by mass or more, and still more preferably 60% by mass or more. The hydrogel according to any one of <14> to <19>, preferably 90% by mass or less, more preferably 85% by mass or less, further preferably 80% by mass or less, and still more preferably 78% by mass or less. Gel particles.

  <21> Mass ratio of the content of the crystalline whitening agent to the content of the liquid oil in the dispersed phase (crystalline whitening agent / liquid oil), preferably the content of the aliphatic dicarboxylic acid ester in the dispersed phase The mass ratio of the content of the crystalline whitening agent with respect to (crystalline whitening agent / aliphatic dicarboxylic acid ester) is preferably 0.03 or more, more preferably 0.05 or more, still more preferably 0.1 or more. The hydrogel particles according to any one of <14> to <20>, preferably 0.5 or less, more preferably 0.3 or less, and still more preferably 0.2 or less.

  <22> The content of the oil and fat component comprising the solid fat and the liquid oil in the dispersed phase is preferably 60% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more. The hydrogel particles according to any one of <14> to <21>, preferably 98% by mass or less, more preferably 95% by mass or less, and still more preferably 93% by mass or less.

  <23> The total content of the liquid oil in the hydrogel particles is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and still more preferably 20% by mass or more. Moreover, Preferably it is 50 mass% or less, More preferably, it is 40 mass% or less, More preferably, it is 30 mass% or less, More preferably, it is 25 mass% or less, Any one of said <14>-<22>. Hydrogel particles.

  <24> The total content of the fat and oil component composed of the solid fat and the liquid oil in the hydrogel particles is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and still more. Preferably, it is 24% by mass or more, preferably 40% by mass or more, more preferably 35% by mass or more, and further preferably 31% by mass or more, according to any one of <14> to <23>. Hydrogel particles.

  <25> The content of the continuous phase in the hydrogel particles is preferably 30% by mass or more, more preferably 40% by mass or more, still more preferably 50% by mass or more, and still more preferably 60% by mass or more. The hydrogel particles according to any one of <1> to <24>, preferably 95% by mass or less, more preferably 90% by mass or less, and still more preferably 80% by mass or less.

  <26> The hydrogel particles according to any one of <1> to <25>, wherein the gel forming agent is agar.

  <27> The content of the gel-forming agent in the continuous phase is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1.5% by mass or more. Is 8 mass% or less, More preferably, it is 5 mass% or less, More preferably, it is 3 mass% or less, The hydrogel particle in any one of said <1>-<26>.

  <28> The content of the gel-forming agent in the hydrogel particles is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and preferably The hydrogel particle according to any one of <1> to <27>, which is 5% by mass or less, more preferably 3% by mass or less, and still more preferably 2% by mass or less.

  <29> The dissolution temperature of the non-crosslinked hydrogel of the continuous phase is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, still more preferably 75 ° C. or higher, and preferably 98 ° C. or lower, more preferably The hydrogel particle according to any one of <1> to <28>, which is 95 ° C. or lower.

  <30> The gelation temperature of the non-crosslinked hydrogel of the continuous phase is preferably 20 ° C. or higher, more preferably 25 ° C. or higher, still more preferably 30 ° C. or higher, and preferably 50 ° C. or lower, more preferably Is a hydrogel particle according to any one of <1> to <29>, which is 45 ° C. or lower.

  <31> The content of the dispersed phase is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, still more preferably 20% by mass or more, and still more preferably 25% by mass. Or more, preferably 70% by mass or less, more preferably 60% by mass or less, further preferably 50% by mass or less, still more preferably 40% by mass or less, and still more preferably 35% by mass or less, <1> -The hydrogel particle in any one of <30>.

  <32> The content of the solid fat in the dispersed phase is preferably 4% by mass or more, more preferably 6% by mass or more, still more preferably 10% by mass or more, and still more preferably 11% by mass or more. Preferably, it is 50 mass% or less, More preferably, it is 40 mass% or less, More preferably, it is 34 mass% or less, More preferably, it is 30 mass% or less, More preferably, it is 29 mass% or less, <1>-< 31> The hydrogel particle according to any one of

  <33> The total content of the solid fat in the hydrogel particles is preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 2.5% by mass or more, and still more preferably 3% by mass or more. And preferably 30% by mass or less, more preferably 25% by mass or less, still more preferably 20% by mass or less, still more preferably 15% by mass or less, and still more preferably 10% by mass or less. The hydrogel particles according to any one of 1> to <32>.

  <34> The content of the fatty acid glyceride in the dispersed phase is preferably 2% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, and still more preferably 6% by mass or more. The hydrogel according to any one of <1> to <33>, preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 17% by mass or less, and still more preferably 15% by mass or less. Gel particles.

  <35> The total content of the fatty acid glycerides in the hydrogel particles is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. 5% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, and still more preferably 5% by mass or less, according to any one of <1> to <34>. Gel particles.

  <36> The total content of the fatty acid glyceride and the higher alcohol in the dispersed phase is preferably 4% by mass or more, more preferably 6% by mass or more, still more preferably 10% by mass or more, and still more preferably 11% by mass. Or more, preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 34% by mass or less, still more preferably 30% by mass or less, still more preferably 29% by mass or less, <1> -The hydrogel particle in any one of <35>.

  <37> The total content of the higher alcohol in the hydrogel particles is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and still more preferably 1. <1> to <36, which is 5% by mass or more, preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less, and still more preferably 5% by mass or less. > The hydrogel particle in any one of.

  <38> The total total content of the fatty acid glyceride and the higher alcohol in the hydrogel particles is preferably 1% by mass or more, more preferably 2% by mass or more, and further preferably 3% by mass or more. Is 30% by mass or less, more preferably 25% by mass or less, still more preferably 20% by mass or less, still more preferably 15% by mass or less, and still more preferably 10% by mass or less. <1> to <37> The hydrogel particle according to any one of the above.

  <39> The content of the crystalline whitening agent in the dispersed phase is preferably 3% by mass or more, more preferably 5% by mass or more, still more preferably 8% by mass or more, and preferably 25% by mass or less. The hydrogel particles according to any one of <1> to <38>, more preferably 20% by mass or less, further preferably 15% by mass or less, and still more preferably 13% by mass or less.

  <40> The total content of the crystalline whitening agent in the hydrogel particles is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and still more preferably. <1> to <39, which is 2% by mass or more, preferably 10% by mass or less, more preferably 7% by mass or less, still more preferably 5% by mass or less, and still more preferably 4% by mass or less. > The hydrogel particle in any one of.

  <41> The volume-based average particle size of the hydrogel particles is preferably 10 μm or more, more preferably 20 μm or more, still more preferably 30 μm or more, and preferably 10,000 μm or less, more preferably 1000 μm or less, still more preferably. The hydrogel particle according to any one of <1> to <40>, which is 250 μm or less.

  <42> A solid fat containing fatty acid glyceride and a higher alcohol having 14 to 22 carbon atoms, a crystalline whitening agent having a biphenyl skeleton, a gel forming agent, and a dispersion containing water, preferably a dropping method, a spraying method, or The hydrogel particles according to any one of <1> to <42>, which are obtained by cooling and solidifying into droplets by a stirring method, more preferably a dropping method or a spraying method, and still more preferably a spraying method.

  <43> A whitening cosmetic containing the hydrogel particles according to any one of <1> to <42>.

  <44> The content of the hydrogel particles is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, and preferably 80% by mass or less, more preferably 60%. Whitening cosmetics as described in said <43> which are the mass% or less, More preferably, it is 50 mass% or less.

  <45> The content of the crystalline whitening agent in the whitening cosmetic is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.3% by mass or more. The whitening cosmetic according to <43> or <44>, preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 3% by mass or less.

  <46> Fatty acid glyceride and a solid fat containing a higher alcohol having 14 to 22 carbon atoms, a crystalline whitening agent having a biphenyl skeleton, a gel-forming agent, and a dispersion containing water, preferably a dropping method, a spraying method, or The method for producing hydrogel particles according to any one of <1> to <42>, wherein the droplets are cooled and solidified by a stirring method, more preferably a dropping method or a spraying method, more preferably a spraying method.

  <47> The method for producing hydrogel particles according to <46>, wherein the dispersion further contains liquid oil.

(Hydrogel particles)
The following hydrogel particles of Examples 1 to 10 and Comparative Examples 1 and 2 were prepared. It shows also in Tables 1-3 about each structure.

<Example 1>
Fatty acid glyceride A1 (a1) stearic acid glyceride (trade name: Leodol MS-60, stearic acid monoglyceride 60% by mass, stearic acid diglyceride 40% by mass), higher alcohol A2 (a2-1) cetyl alcohol (Kao) Product name: Calcoal 6098, carbon number 16 in the molecule) and (a2-2) stearyl alcohol (product name: Calcoal 8098, carbon number 18 in the molecule), high crystalline whitening agent B as (b) di A dispersed phase component liquid containing propylbiphenyldiol (trade name: Magnolignan manufactured by Hasegawa Koryo Co., Ltd.) and (c) diisopropyl sebacate (trade name: N-DIS manufactured by Nippon Surfactant Kogyo Co., Ltd.) as liquid oil C was prepared. At this time, each content in the hydrogel particle obtained is (a1) stearic acid glyceride 4 mass%, (a2-1) cetyl alcohol 1.2 mass%, (a2-2) stearyl alcohol 0.8 mass%. (B) 3% by mass of dipropylbiphenyldiol, and (c) 21% by mass of diisopropyl sebacate.

  Agar as a gel forming agent (trade name: CS-16A, manufactured by Ina Food Industry Co., Ltd., dissolution temperature of non-crosslinked hydrogel: 92 ° C., gelation temperature of non-crosslinked hydrogel: 40 ° C.), acrylic acid as emulsifying dispersant -Alkyl methacrylate copolymer (trade name: PEMULEN TR-2 manufactured by Nikko Chemicals) and polyvinyl alcohol (trade name: Gohsenol EG-05 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), 1N NaOH aqueous solution (manufactured by Kishida Chemical Co., Ltd.) as a pH adjuster ), And a continuous phase component liquid containing ion-exchanged water. At this time, each content in the obtained hydrogel particles was 1.5% by mass of agar, 0.1% by mass of acrylic acid / alkyl methacrylate copolymer, 0.5% by mass of polyvinyl alcohol, and 1N NaOH aqueous solution. Mixing was performed so that 75% by mass and ion-exchanged water were the other balance.

  A total of 1000 g of the dispersed phase component liquid and the continuous phase component liquid were prepared so as to have a mass ratio of 30:70, and the dispersed phase component liquid was heated and dissolved at 80 ° C. and the continuous phase component liquid was heated at 90 ° C., respectively. Thereafter, the dispersed phase component liquid is added to the continuous phase component liquid, and the mixture is stirred for 1 minute at a rotational speed of 8000 rpm using a homomixer (trade name: TK Robotics, manufactured by Primics) to disperse the oil in water type. A liquid was prepared.

  The temperature of the dispersion liquid is maintained at 80 ° C., and at a height of 3.4 m in the tank, the dispersion liquid is supplied from a spray nozzle (Ikeuchi Co., Ltd. empty cone nozzle K-010) at a flow rate of 12 kg / hr. It sprayed in the gaseous phase of 25 degreeC, and the hydrogel particle which the droplet of the dispersion liquid formed by spraying solidified by cooling was collect | recovered in the tank lower part. And this hydrogel particle was made into Example 1. FIG.

  The hydrogel particles of Example 1 were measured using a laser diffraction scattering method (for example, model number: LA-920, manufactured by Horiba, Ltd.), and the volume-based average particle diameter was about 150 μm. The hydrogel particles of Examples 2 to 10 and Comparative Examples 1 and 2 below also had a volume-based average particle size of about 150 μm.

  When the magnolignan as a raw material was measured under the following conditions using an X-ray diffractometer (“Rigaku RINT 2500VC X-RAYdiffractometer” manufactured by Rigaku Corporation), a diffraction angle 2θ = 13.2 °, 20.6 °, X-ray diffraction intensity peaks were observed at 21.9 ° and 24.0 °. On the other hand, in the produced hydrogel particles of Example 1, a peak was not observed at the same diffraction angle, but a peak of X-ray diffraction intensity thought to be derived from the film structure was observed at a diffraction angle 2θ = 21.5 °. .

  The measurement conditions were X-ray source: Cu / Kα-radiation, tube voltage: 40 kv, tube current: 120 mA, measurement range: diffraction angle 2θ = 5-45 °, and X-ray scan speed: 10 ° / min.

<Example 2>
The content of (a1) glyceride stearate in the resulting hydrogel particles is 3.0% by mass, the content of (a2-1) cetyl alcohol is 1.8% by mass, and the content of (a2-2) stearyl alcohol. A hydrogel particle having the same structure as that of Example 1 was prepared except that the formulation was adjusted to 1.2 mass%.

<Example 3>
The content of (a1) glyceride stearate in the resulting hydrogel particles is 2.0% by mass, the content of (a2-1) cetyl alcohol is 2.4% by mass, and the content of (a2-2) stearyl alcohol. A hydrogel particle having the same configuration as that of Example 1 was prepared except that blending was performed so that the amount was 1.6% by mass.

<Example 4>
Only (a2-2) stearyl alcohol is used as the higher alcohol A2, the content of (a1) glyceride stearate in the resulting hydrogel particles is 3.0% by mass, and the content of (a2-2) stearyl alcohol is 3. A hydrogel particle having the same configuration as that of Example 1 was prepared except that the mixing was performed so that the content became 0.0% by mass.

<Example 5>
(A2-3) behenyl alcohol (trade name: Calcoal 8098, carbon number 22 in the molecule) was used as the higher alcohol A2, and the content of (a2-3) behenyl alcohol in the resulting hydrogel particles was 2.0 mass. %, Hydrogel particles having the same structure as in Example 1 were prepared except that the blending was performed so as to be 5%.

<Example 6>
Except for blending so that the content of (a1) glyceride stearate in the resulting hydrogel particles is 3.0 mass% and the content of (a2-3) behenyl alcohol is 3.0 mass%. A hydrogel particle having the same configuration as that of Example 5 was produced.

<Example 7>
Except for blending such that the content of (a1) glyceride stearate in the resulting hydrogel particles is 2.0 mass% and the content of (a2-3) behenyl alcohol is 4.0 mass%. Hydrogel particles having the same configuration as in Example 5 were produced, and this was designated as Example 7.

<Example 8>
The content of (a1) glyceride stearate in the resulting hydrogel particles is 1.5% by mass, the content of (a2-1) cetyl alcohol is 0.75% by mass, and the content of (a2-2) stearyl alcohol The hydrogel particles having the same configuration as in Example 1 except that the dispersion phase component liquid and the continuous phase component liquid were mixed at a mass ratio of 27:73. This was made into Example 8.

<Example 9>
The content of (a1) glyceride stearate in the obtained hydrogel particles is 5.0% by mass, the content of (a2-1) cetyl alcohol is 2.5% by mass, and the content of (a2-2) stearyl alcohol. The hydrogel particles having the same configuration as that of Example 1 except that the dispersion phase component liquid and the continuous phase component liquid were mixed at a mass ratio of 34:66. This was made into Example 9.

<Example 10>
(A2-4) Myristyl alcohol (trade name: Calcoal 4098, carbon number 14 in the molecule) is used as the higher alcohol A2, and the content of (a1) stearic acid glyceride in the obtained hydrogel particles is 3.0. A hydrogel particle having the same configuration as that of Example 1 was prepared except that the blending was performed so that the content of the mass% and (a2-4) myristyl alcohol was 3.0 mass%. It was set to 10.

<Comparative Example 1>
Mixing is performed so that the content of (a1) glyceride stearate in the resulting hydrogel particles is 3.0% by mass without using the higher alcohol A2, and the mass ratio of the dispersed phase component liquid and the continuous phase component liquid is A hydrogel particle having the same structure as that of Example 1 was prepared except that the mixing was performed at a ratio of 27:73.

<Comparative example 2>
Without using fatty acid glyceride A1, (a2-2) stearyl alcohol is used as higher alcohol A2, and blending is performed so that the content of (a2-2) stearyl alcohol in the resulting hydrogel particles is 3.0% by mass. And the hydrogel particle of the same structure as Example 1 was produced except having mixed the dispersed phase component liquid and the continuous phase component liquid in the ratio of mass ratio 27:73, and this was made into Comparative Example 2.

(Storage stability test evaluation method)
About each hydrogel particle of Examples 1-10 and Comparative Examples 1-2, 50 mass% of hydrogel particles, 0.2 mass% of phenoxyethanol (Toho Chemical Co., Ltd. product name: Hisolv EPH), 10 mass% of ethanol, and A slurry-like cosmetic material having a composition ratio of 49.8% by mass of purified water was prepared.

  Next, the slurry is stored under each temperature atmosphere of 5 ° C., room temperature, and 40 ° C., and the state of the slurry containing the hydrogel particles is measured using a CCD (trade name: DIGITAL MICROSCOPE VHX-500 manufactured by KEYENCE). Observed over time.

  If the crystalline whitening agent crystals are precipitated within 1 month from the start of storage in the slurry, C is deposited for more than 1 month and within 2 months, and B is not deposited even after 2 months. Was evaluated as A. Moreover, about Examples 1-10, observation was continued for a maximum of seven months, and the period until the crystal | crystallization of a crystalline whitening agent precipitated from a storage start was investigated. In all temperature regions under 5 ° C., room temperature (25 ° C.), and 40 ° C. atmosphere, the evaluation requires B or more, and A is preferable.

(Test evaluation results)
Table 4 shows the test results. In Table 4, “> 7 months” means that no precipitation of crystalline whitening agent was observed after 7 months from the start of storage. Similarly, “> 2 months” It means that no precipitation of crystalline whitening agent crystals is observed when 2 months have passed since the start.

  As for the storage stability evaluation at 5 ° C., room temperature (25 ° C.) and 40 ° C., in Examples 1 to 10, no precipitation of crystalline whitening agent crystals was observed even after 1 month from the start of storage. In Comparative Example 1 in which the evaluation was A or B but no higher alcohol was used, and in Comparative Example 2 in which no fatty acid glyceride was used, the crystalline whitening agent at any temperature in 3 weeks from the start of storage The crystal was deposited, and there was a portion with an evaluation of C.

  Comparing Example 4 using stearyl alcohol, Example 6 using behenyl alcohol, and Example 10 using myristyl alcohol, in Example 4, crystals were observed in all temperature ranges even after 7 months from the start of storage. In Example 6, there was a temperature range in which crystals were precipitated in 3 months from the start of storage, and in Example 10, there was a temperature range in which crystals were precipitated in 2 months from the start of storage. From these, it can be seen that stearyl alcohol has the highest storage stability.

  Even in Examples 1 to 3 in which cetyl alcohol and stearyl alcohol were used in combination, no precipitation of crystals was observed in all temperature regions even after 7 months from the start of storage, indicating that the storage stability is high.

  Moreover, the cosmetics containing the hydrogel particles of Examples 1 to 10 were easy to extend on the skin and were excellent in touch. This is presumably because the crystalline whitening agent is not crystallized in the hydrogel particles.

  INDUSTRIAL APPLICATION This invention is useful about hydrogel particle, its manufacturing method, and the whitening cosmetics using the same.

Claims (12)

A continuous phase of a non-crosslinked hydrogel, and a dispersed phase dispersed in the continuous phase,
The said dispersed phase is hydrogel particle containing the fatty acid glyceride and the solid fat containing a C14-C22 higher alcohol, and the crystalline whitening agent which has a biphenyl skeleton.   The hydrogel particles according to claim 1, wherein the higher alcohol has 16 to 22 carbon atoms.   The hydrogel particles according to claim 1 or 2, wherein the content of the higher alcohol in the dispersed phase is 2 to 25% by mass.   The hydrogel particle according to any one of claims 1 to 3, wherein a mass ratio of the fatty acid glyceride content to the higher alcohol content in the dispersed phase (fatty acid glyceride / higher alcohol) is 0.2 to 4. .   The mass ratio of the content of the crystalline whitening agent to the total content of the fatty acid glyceride and the higher alcohol in the dispersed phase (crystalline whitening agent / (fatty acid glyceride + higher alcohol)) is 0.1 to 3. The hydrogel particles according to any one of claims 1 to 4. The hydrogel particle in any one of Claims 1-5 in which the said fatty-acid glyceride contains the compound represented by the following general formula (I).
R ₁ COOCH ₂ (CHX) CH ₂ Y (I)
(Wherein, X and Y each independently represent OH or OCOR ₂ , and R ₁ and R ₂ each independently represent a saturated hydrocarbon group having 13 to 21 carbon atoms)   The hydrogel particle according to any one of claims 1 to 6, wherein the crystalline whitening agent comprises 2,2'-dihydroxy-5,5'-di-n-propylbiphenyl.   The hydrogel particle according to any one of claims 1 to 7, wherein the dispersed phase further contains a liquid oil. The hydrogel particles according to claim 8, wherein the liquid oil contains an aliphatic dicarboxylic acid ester represented by the following general formula (i).

  A whitening cosmetic comprising the hydrogel particles according to claim 1.   A solid fat containing a fatty acid glyceride and a higher alcohol having 14 to 22 carbon atoms, a crystalline whitening agent having a biphenyl skeleton, a gel-forming agent, and water-containing dispersion liquid are dropped by a dropping method, a spraying method, or a stirring method. The hydrogel particles according to claim 1, which are obtained by cooling and solidifying.   A solid fat containing a fatty acid glyceride and a higher alcohol having 14 to 22 carbon atoms, a crystalline whitening agent having a biphenyl skeleton, a gel-forming agent, and water-containing dispersion liquid are dropped by a dropping method, a spraying method, or a stirring method. The method for producing hydrogel particles according to claim 1, wherein the hydrogel particles are cooled and solidified.