Hydrogel structure

Abstract

A hydrogel structure (10) is provided with a first hydrogel continuous phase (11) and a second hydrogel dispersed phase (12) dispersed in the continuous phase (11). The ratio of the minimum value of load after breaking to the breaking load of the hydrogel structure (10) (minimum value of load after breaking / breaking load) is 0.1 or more.

Description

Technical Field

[0001] The present invention relates to a hydrogel structure, a method for producing the same, a cosmetic composition containing the hydrogel structure, and use of the hydrogel structure as a cosmetic.

Background Art

[0002] Hydrogels are widely used in cosmetics, pharmaceuticals, quasi-drugs, foods, and the like. For example, Patent Document 1 discloses a form in which seamless capsules having an outer film formed of agar or the like are dispersed in a gummy raw material containing gelatin. Patent Document 2 discloses hydrogel particles in which a dispersed phase of an oily component is dispersed in a continuous phase of a hydrogel. Patent Document 3 discloses a jelly food in which particles of a hydrogel are dispersed in a hydrogel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0004] The present invention provides a hydrogel structure comprising a continuous phase of a first hydrogel and a dispersed phase of a second hydrogel dispersed in the continuous phase, wherein a ratio (minimum value of the load after fracture / fracture load) of the minimum value of the load after fracture to the fracture load is 0.1 or more.

[0005] The present invention provides a hydrogel structure comprising a continuous phase of a first hydrogel and a dispersed phase of a second hydrogel dispersed in the continuous phase, wherein a mass ratio (dispersed phase / continuous phase) of the dispersed phase to the continuous phase exceeds 1 / 99.

[0006] The present invention relates to a cosmetic composition containing the hydrogel structure of the present invention.

[0007] The present invention relates to the use of the hydrogel structure of the present invention as a cosmetic.

[0008] The present invention relates to a method for producing the hydrogel structure of the present invention, in which hydrogel particles that become the dispersed phase of the second hydrogel are dispersed in a first aqueous gel agent solution for forming the continuous phase of the first hydrogel, and then the first aqueous gel agent solution is gelled.

[0009] The present invention relates to a method for producing a hydrogel structure in which a second hydrogel is dispersed in a first aqueous gel agent solution for forming the continuous phase of the first hydrogel, and then the first aqueous gel agent solution is gelled, wherein the temperature of the first aqueous gel agent solution when the second hydrogel is dispersed is equal to or higher than the freezing point of the first aqueous gel agent solution and lower than the melting point of the second hydrogel.

Brief Description of the Drawings

[0010]

Figure 1

Modes for Carrying Out the Invention

[0011] Hereinafter, the embodiments will be described in detail.

[0012] FIG. 1 shows a hydrogel structure 10 according to an embodiment. The hydrogel structure 10 according to the embodiment can be used, for example, as a cosmetic, a pharmaceutical, a quasi-drug, a food, etc., and can be preferably used as a component to be contained in a cosmetic composition.

[0013] The hydrogel structure 10 according to the embodiment includes a continuous phase 11 and a dispersed phase A12 dispersed in the continuous phase 11.

[0014] Incidentally, for example, cosmetics such as emulsions are usually used by taking an appropriate amount and spreading it on the palm. At this time, if a hydrogel is used in the cosmetic, the hydrogel will be crushed on the palm. However, if the gel strength of the hydrogel is high, there is a problem that it is difficult to crush it on the palm and it takes time to crush it. Therefore, it is conceivable to increase the water content to lower the gel strength of the hydrogel, but in that case, bleeding of water from the hydrogel will increase. Also, it is conceivable to add oil or powder to lower the gel strength, but in that case, it will be necessary to contain those unnecessary components.

[0015] However, according to the hydrogel structure 10 according to this embodiment, since the dispersed phase A12 of the second hydrogel is dispersed in the continuous phase 11 of the first hydrogel, excellent disintegrability can be obtained. Although the reason why the hydrogel structure 10 according to this embodiment exhibits such an effect is not clear, due to the presence of the dispersed phase A12, the hydrogel structure 10 is difficult to elastically deform before disintegration, so it is considered that excellent disintegrability can be obtained while maintaining the breaking load within a range that can ensure the storage stability of the hydrogel structure 10.

[0016] The content of the continuous phase 11 in the hydrogel structure 10 is preferably 20% by mass or more, more preferably 30% by mass or more, still more preferably 40% by mass or more, from the viewpoint of ensuring the storage stability of the hydrogel structure, and preferably 80% by mass or less, more preferably 70% by mass or less, still more preferably 60% by mass or less, from the viewpoint of obtaining excellent disintegrability of the hydrogel structure.

[0017] The continuous phase 11 is formed of a first hydrogel. Here, the "hydrogel" in the present application refers to a gel obtained from a gelling agent and water, and means a gel formed by the thermoreversibility of sol-gel, for example, when the gelling agent is agar. The "gelling agent" refers to a water-soluble organic compound, and an aqueous solution obtained by dissolving this in water undergoes a sol-gel transition at the gelling point (freezing point). Therefore, assuming that the first hydrogel is obtained from a first gelling agent and water, the continuous phase 11 is formed by the first aqueous gelling agent solution containing the first gelling agent generating the first hydrogel at a temperature lower than the gelling point.

[0018] The first gelling agent contains a water-soluble polymer. Examples of the water-soluble polymer include water-soluble non-crosslinked polymers such as agar, carrageenan, gellan gum, xanthan gum, and high-methoxyl pectin. From the viewpoint of obtaining excellent disintegrability of the hydrogel structure, the first gelling agent preferably contains a water-soluble non-crosslinked polymer, more preferably contains one or more selected from the group consisting of agar, carrageenan, gellan gum, xanthan gum, and high-methoxyl pectin, and still more preferably contains agar. Here, the "agar" in the present application refers to hemicellulose containing galactan composed of 1,3 bonds and 1,4 bonds of galactose.

[0019] The jelly strength of the first gelling agent is, for example, 19.6 kPa (200 g / cm 2 ) or more and 147 kPa (1500 g / cm 2 ) or less. Here, the jelly strength of the gelling agent can be determined by the Nissin method. Specifically, the jelly strength of the gelling agent is obtained by preparing a 1.5 mass% aqueous solution of the gelling agent, allowing the aqueous solution to stand at 20°C for 15 hours to solidify it into a hydrogel, applying a load to the hydrogel with a Nissin jelly strength measuring instrument (manufactured by Kiyaki Seisakusho Co., Ltd.), and measuring the maximum mass (g) per 1 cm 2 of the surface area when the hydrogel withstands the load for 20 seconds at 20°C.

[0020] The content of the first gelling agent in the continuous phase 11 is preferably 0.8% by mass or more, more preferably 1.0% by mass or more, still more preferably 1.2% by mass or more, from the viewpoint of ensuring the storage stability of the hydrogel structure, and is 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 6% by mass or less from the viewpoint of obtaining excellent disintegrability of the hydrogel structure.

[0021] The continuous phase 11 may contain an emulsifying and dispersing agent. Examples of the emulsifying and dispersing agent include polymer emulsifying and dispersing agents, nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. The emulsifying and dispersing agent preferably contains one or more of these.

[0022] The content of the emulsifying and dispersing agent in the continuous phase 11 is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, from the viewpoint of ensuring the storage stability of the hydrogel structure, and is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 2% by mass or less from the same viewpoint.

[0023] In addition, the continuous phase 11 may contain water-soluble vitamins B and C, a humectant, an antiperspirant, an antibacterial agent, a bactericide, etc.

[0024] The breaking load of the continuous phase 11 is preferably 0.1 N or more, more preferably 1 N or more, still more preferably 5 N or more, from the viewpoint of ensuring the storage stability of the hydrogel structure, and is preferably 30 N or less, more preferably 20 N or less, still more preferably 15 N or less from the viewpoint of obtaining excellent disintegrability of the hydrogel structure. This breaking load is measured by the method described in the examples below.

[0025] In the hydrogel structure 10, the mass ratio of the dispersed phase A12 to the continuous phase 11 (dispersed phase A12 / continuous phase 11) exceeds 1 / 99, preferably 3 / 97 or more, more preferably 13 / 87 or more, still more preferably 15 / 85 or more, from the viewpoint of obtaining excellent disintegrability of the hydrogel structure, and is preferably 99 / 1 or less, more preferably 80 / 20 or less, still more preferably 40 / 60 or less, still more preferably 25 / 75 or less, from the viewpoint of ensuring the storage stability of the hydrogel structure.

[0026] The content of the dispersed phase A12 in the hydrogel structure 10 is preferably 3% by mass or more, more preferably 13% by mass or more, still more preferably 20% by mass or more, still more preferably 30% by mass or more, still more preferably 40% by mass or more, from the viewpoint of obtaining excellent disintegrability of the hydrogel structure, and is preferably 99% by mass or less, more preferably 90% by mass or less, still more preferably 80% by mass or less, still more preferably 70% by mass or less, still more preferably 60% by mass or less, from the viewpoint of ensuring the storage stability of the hydrogel structure.

[0027] The dispersed phase A12 is formed of a second hydrogel. Assuming that the second hydrogel is obtained from a second gelling agent and water, the dispersed phase A12 is formed by the second gelling agent aqueous solution containing the second gelling agent generating the second hydrogel at a temperature lower than the gelling point. The melting point of the dispersed phase A12 is preferably higher than the freezing point of the first gelling agent aqueous solution, for example, 85 to 95 °C, from the viewpoint of ensuring the storage stability of the hydrogel structure.

[0028] Examples of the second gelling agent include the same ones as the above-mentioned first gelling agent. From the viewpoint of obtaining excellent disintegrability of the hydrogel structure, the second gelling agent preferably contains one or more of them, and more preferably contains agar. The second gelling agent may be the same as or different from the first gelling agent.

[0029] The jelly strength of the second gelling agent and the gelling point (freezing point) of the second gelling agent aqueous solution are the same as those of the above-mentioned first gelling agent and the first gelling agent aqueous solution.

[0030] From the viewpoint of ensuring the storage stability of the hydrogel structure, the content of the second gelling agent in the dispersed phase A12 is preferably 0.8% by mass or more, more preferably 1.0% by mass or more, still more preferably 1.2% by mass or more. From the viewpoint of obtaining excellent disintegrability of the hydrogel structure, it is preferably 10% by mass or less, more preferably 8% by mass or less, still more preferably 6% by mass or less.

[0031] The second gelling agent may be the same as the first gelling agent. In that case, the content of the second gelling agent in the dispersed phase A12 may be the same as the content of the first gelling agent in the continuous phase 11. That is, the first hydrogel and the second hydrogel may have the same composition.

[0032] The dispersed phase A12 may contain an emulsifying and dispersing agent. Examples of the emulsifying and dispersing agent are the same as those in the case of the continuous phase 11 above. The preferred content of the emulsifying and dispersing agent in the dispersed phase A12 is also the same as in the case of the continuous phase 11 above.

[0033] The dispersed phase A12 may have the same composition as the continuous phase 11 or a different composition. Similar to the continuous phase 11, the dispersed phase A12 may also contain other water-soluble vitamins B and C, humectants, antiperspirants, antibacterial agents, bactericides, etc.

[0034] Examples of the shape of the dispersed phase A12 include granular shapes such as spherical, plate-like, needle-like, etc. In this specification, the term "spherical" includes not only true spheres but also substantially spherical shapes such as ellipsoids and those with irregularities on their surfaces. From the viewpoints of obtaining excellent disintegrability and storage stability, the average particle diameter of the dispersed phase A12 is preferably 1 μm or more, more preferably 5 μm or more, still more preferably 10 μm or more. From the viewpoint of obtaining a good feel when applied to the skin, it is preferably 5 mm or less, more preferably 3 mm or less, still more preferably 2 mm or less. This average particle diameter of the dispersed phase A12 is the volume-based average particle diameter measured by the laser diffraction scattering method using a laser diffraction / scattering particle size distribution measuring device (for example, LA-960 manufactured by Horiba, Ltd.).

[0035] From the viewpoint of obtaining excellent collapsibility of the hydrogel structure, the breaking load of the dispersed phase A12 is preferably 0.1 N or more, more preferably 1 N or more, still more preferably 5 N or more, and from the same viewpoint, it is preferably 30 N or less, more preferably 20 N or less, still more preferably 15 N or less. This breaking load is measured by the method described in the examples below.

[0036] From the viewpoint of ensuring the storage stability of the hydrogel structure, the content of the first gelling agent and the second gelling agent in the hydrogel structure 10 is preferably 0.8% by mass or more, more preferably 1.0% by mass or more, still more preferably 1.2% by mass or more, and from the viewpoint of obtaining excellent collapsibility, it is 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 6% by mass or less.

[0037] Also, from the viewpoint of ensuring the storage stability of the hydrogel structure, the content of the emulsifying dispersant in the hydrogel structure 10 is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, still more preferably 0.5% by mass or more, and from the same viewpoint, it is preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less.

[0038] The hydrogel structure 10 according to the embodiment may include dispersed particles B13 different from the dispersed phase A12 dispersed in the continuous phase 11.

[0039] Examples of the dispersed particles B13 include water-insoluble cosmetic components and the like. Examples of such water-insoluble cosmetic components include cosmetic oily components such as silicone oil, ceramide, and fat-soluble vitamins; cosmetic powders such as titanium oxide, zinc oxide, and pigments. The dispersed particles B13 preferably contain one or more of these. Here, "water-insoluble" means that the solubility in water at 20 °C is 1% by mass or less.

[0040] From the perspective of using the hydrogel structure as a cosmetic, the content of the dispersed particles B13 in the hydrogel structure 10 is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 10% by mass or more. From the perspective of ensuring the storage stability of the hydrogel structure, it is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less.

[0041] Examples of the shape of the dispersed particles B13 include granular shapes such as spherical, plate-like, needle-like, etc. From the perspective of ensuring emulsion stability, the average particle size of the dispersed particles B13 is preferably 0.1 μm or more, more preferably 1 μm or more, still more preferably 5 μm or more. From the same perspective, it is preferably 100 μm or less, more preferably 50 μm or less, still more preferably 20 μm or less. The average particle size of this dispersed particles B13 is also the volume-based average particle size. The average particle size of the dispersed particles B13 is preferably smaller than the average particle size of the dispersed phase A12.

[0042] The hydrogel structure 10 according to the embodiment may include dispersed particles C14 dispersed in the dispersed phase A12. The type, content, shape, and size of the dispersed particles C14 are the same as those of the dispersed particles B13.

[0043] Examples of the shape of the hydrogel structure 10 according to the embodiment include granular shapes such as spherical, plate-like, needle-like, and the like. The maximum dimension of the hydrogel structure 10 is preferably 500 μm or more, more preferably 1 mm or more, still more preferably 5 mm or more, and even more preferably 10 mm or more from the viewpoint of ensuring the ease of blending and dispersion stability of the dispersed phase A12. From the viewpoints of the ease of molding and handling of the hydrogel structure 10, it is preferably 40 mm or less, more preferably 30 mm or less, and still more preferably 20 mm or less. In this specification, the "maximum dimension" means the maximum value of the dimensions that can be taken within the hydrogel structure. When the shape of the hydrogel structure is ellipsoidal, the "maximum dimension" means the length of the major axis of the hydrogel structure, and when it is spherical, it means the diameter of the hydrogel structure. When the hydrogel structure 10 is used alone in a paste form, the maximum dimension of the hydrogel structure 10 is preferably 500 μm or more and 1 mm or less from the viewpoint of ensuring the fluidity of the paste preparation. When the hydrogel structure 10 is used by being blended in a preparation, the maximum dimension of the hydrogel structure 10 is preferably 500 μm or more and 5 mm or less from the viewpoint of the dispersion stability of the hydrogel structure 10.

[0044] In addition, the ratio of the maximum dimension of the hydrogel structure 10 to the average particle diameter of the dispersed phase A12 is preferably 1 or more, more preferably 5 or more, still more preferably 10 or more from the viewpoints of the ease of blending and dispersion stability of the dispersed phase A12. From the viewpoints of the ease of molding and handling of the hydrogel structure 10, it is preferably 50000 or less, more preferably 10000 or less, still more preferably 1000 or less, even more preferably 800 or less, and even more preferably 700 or less.

[0045] The breaking load of the hydrogel structure 10 according to the embodiment is preferably 0.1 N or more, more preferably 0.3 N or more, still more preferably 0.5 N or more, from the viewpoint of ensuring the storage stability of the hydrogel structure, and preferably 30 N or less, more preferably 20 N or less, still more preferably 15 N or less, still more preferably 10 N or less, still more preferably 5 N or less, from the viewpoint of obtaining excellent collapsibility of the hydrogel structure. The ratio of the minimum value of the load after breaking to the breaking load (minimum value of the load after breaking / breaking load) of the hydrogel structure 10 according to the embodiment is 0.1 or more, preferably 0.2 or more, more preferably 0.33 or more, from the viewpoint of obtaining excellent collapsibility of the hydrogel structure, and preferably 1 or less, more preferably 0.95 or less, still more preferably 0.9 or less, from the viewpoint of ensuring the storage stability of the hydrogel structure.

[0046] The breaking strain rate of the hydrogel structure 10 according to the embodiment is preferably 1% or more, more preferably 3% or more, still more preferably 5% or more, from the viewpoint of ensuring the storage stability of the hydrogel structure, and preferably 50% or less, more preferably 45% or less, still more preferably 40% or less, still more preferably 35% or less, from the viewpoint of obtaining excellent collapsibility of the hydrogel structure. These breaking load, the minimum value of the load after breaking, and the breaking strain rate can be measured, for example, by texture measurement using a texture tester under the condition of 25°C.

[0047] In texture measurement, a texture curve showing the relationship between the compression distance and the load is obtained. In this texture curve, as the compression distance of the hydrogel structure increases, the load increases, and a peak of the load is shown where the hydrogel structure breaks. The breaking load and the breaking strain rate are determined from the peak load and the compression distance at this time. After the hydrogel structure breaks, when the compression distance further increases, the texture curve shows one or more load minima accompanying the morphological change of the broken hydrogel structure, and finally, the broken hydrogel structure shows a rise in load by losing its elasticity. The load minimum value after breaking is determined from the load minimum value at that time when the load minimum value occurs once, and is determined from the minimum value among them when the load minimum value occurs multiple times. From the viewpoint of obtaining a good feeling in use when the hydrogel structure is used in cosmetics or the like, the number of load minima after breaking of the hydrogel structure in the texture curve is preferably one.

[0048] Next, a method for manufacturing the hydrogel structure 10 according to the embodiment will be described.

[0049] First, an aqueous solution of a second gelling agent for forming the dispersed phase A12 is prepared. When dispersing the dispersed particles C14 in the dispersed phase A12, the dispersed particles C14 are dispersed in the aqueous solution of the second gelling agent in advance. Hydrogel particles that will become the dispersed phase A12 of the second hydrogel are produced using this aqueous solution of the second gelling agent.

[0050] Examples of methods for producing hydrogel particles include a dropping method, a spraying method, a stirring method, a disintegration method, and a stirring and cooling method. The dropping method is a method for producing a hydrogel by discharging an aqueous solution of a second gelling agent from a hole, utilizing the property that the discharged aqueous solution of a second gelling agent turns into droplets due to its surface tension or interfacial tension, and cooling and solidifying the droplets in a gas phase such as air or in a liquid phase. The spraying method is a method for producing a hydrogel by using a spray nozzle, spraying an aqueous solution of a second gelling agent from the spray nozzle into a gas phase, forming droplets due to the surface tension, and cooling and solidifying the droplets in the gas phase. The stirring method is a method for producing a hydrogel by introducing the second gelling aqueous solution into a liquid that is substantially immiscible with the second gelling aqueous solution and that has been adjusted to a temperature higher than the gelling point of the second gelling aqueous solution, and by utilizing the property of the second gelling aqueous solution being atomized by shearing force caused by stirring and turning into droplets by interfacial tension, the droplets are cooled and solidified in a liquid that is substantially immiscible with the second gelling aqueous solution, and a hydrogel is produced. The crushing method is a method for mechanically crushing a mass of solidified matter obtained by cooling and solidifying the second gelling aqueous solution. The stirring and cooling method is a method for producing hydrogel particles while stirring the second gelling aqueous solution until it reaches a gelling point or lower.

[0051] Next, a first gelling agent aqueous solution is prepared to form the continuous phase 11 of the first hydrogel. When dispersing the dispersed particles B13 in the continuous phase 11, the dispersed particles B13 are dispersed in advance in the first gelling agent aqueous solution.

[0052] Then, after adding a predetermined amount of hydrogel particles to the first gelling agent aqueous solution and dispersing them, the obtained dispersion is cooled and gelled to obtain the hydrogel structure 10 according to the embodiment. At this time, when the first gelling agent and the second gelling agent are agar, the temperature of the first gelling agent aqueous solution when adding and dispersing the hydrogel particles is preferably not less than the freezing point of the first gelling agent aqueous solution and less than the melting point of the hydrogel particles, more preferably 40°C or higher and 80°C or lower, still more preferably 45°C or higher and 75°C or lower, and still more preferably 50°C or higher and 70°C or lower, from the viewpoint of maintaining the sol state of the first gelling agent aqueous solution and suppressing the resolubilization of the hydrogel particles. Incidentally, the dispersion obtained by adding hydrogel particles to the first gelling agent aqueous solution is poured into a mold before cooling, and the dispersion is cooled and gelled in the mold, whereby a shape can be imparted to the hydrogel structure 10. Further, a shape can be imparted to the hydrogel structure 10 by mechanically crushing the solidified product obtained by cooling the dispersion obtained by adding hydrogel particles to the first gelling agent aqueous solution. Further, in the dropping method, spraying method, stirring method, crushing method, or stirring cooling method, by using the dispersion obtained by adding hydrogel particles to the first gelling agent aqueous solution instead of the second gelling agent aqueous solution, the hydrogel structure 10 according to the embodiment can be made into particles.

[0053] Regarding the above-described embodiments, the following configurations are further disclosed.

[0054] <1>A hydrogel structure comprising a continuous phase of a first hydrogel and a dispersed phase of a second hydrogel dispersed in the continuous phase, wherein the ratio of the minimum value of the load after fracture to the fracture load (minimum value of the load after fracture / fracture load) is 0.1 or more.

[0055] <2>A hydrogel structure comprising a continuous phase of a first hydrogel and a dispersed phase of a second hydrogel dispersed in the continuous phase, wherein the mass ratio of the dispersed phase to the continuous phase (dispersed phase / continuous phase) exceeds 1 / 99.

[0056] <3>The mass ratio of the dispersed phase to the continuous phase (dispersed phase / continuous phase) is preferably 3 / 97 or more, more preferably 13 / 87 or more, still more preferably 15 / 85 or more, and preferably 99 / 1 or less, more preferably 80 / 20 or less, still more preferably 40 / 60 or less, and still more preferably 25 / 75 or less, and is the hydrogel structure described in <1> or <2>.

[0057] <4>The mass ratio of the dispersed phase to the continuous phase (dispersed phase / continuous phase) is 99 / 1 or less, and is the hydrogel structure described in <1> or <2>.

[0058] <5>The mass ratio of the dispersed phase to the continuous phase (dispersed phase / continuous phase) is 3 / 97 or more and 80 / 20 or less, and is the hydrogel structure described in <4>.

[0059] <6>The mass ratio of the dispersed phase to the continuous phase (dispersed phase / continuous phase) is 15 / 85 or more and 80 / 20 or less, and is the hydrogel structure described in <4>.

[0060] <7>The maximum span is preferably 500 μm or more, more preferably 1 mm or more, still more preferably 5 mm or more, and even more preferably 10 mm or more, and preferably 40 mm or less, more preferably 30 mm or less, still more preferably 20 mm or less, and is the hydrogel structure described in any one of <1> to <6>.

[0061] <8>The content of the continuous phase in the hydrogel structure is preferably 20% by mass or more, more preferably 30% by mass or more, still more preferably 40% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, still more preferably 60% by mass or less, and is the hydrogel structure described in any one of <1> to <7>.

[0062] <9>The first gelling agent used to obtain the first hydrogel is preferably a water-soluble non-crosslinked polymer, more preferably one or more selected from the group consisting of agar, carrageenan, gellan gum, xanthan gum, and high-methoxyl pectin, and still more preferably contains agar, the hydrogel structure according to any one of <1> to <8>.

[0063] <10>The content of the first gelling agent in the continuous phase is preferably 0.8% by mass or more, more preferably 1.0% by mass or more, still more preferably 1.2% by mass or more, and 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 6% by mass or less, the hydrogel structure according to any one of <1> to <9>.

[0064] <11>The hydrogel structure according to any one of <1> to <10>, wherein one or both of the continuous phase and the dispersed phase contain an emulsifying and dispersing agent.

[0065] <12>The content of the emulsifying and dispersing agent in the continuous phase or the dispersed phase 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 10% by mass or less, more preferably 5% by mass or less, still more preferably 2% by mass or less, the hydrogel structure according to <10>.

[0066] <13>The content of the emulsifying and dispersing agent in the hydrogel structure is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, still more preferably 0.5% by mass or more, and preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less, the hydrogel structure according to <11> or <12>.

[0067] <14>The breaking load of the continuous phase is preferably 0.1 N or more, more preferably 1 N or more, still more preferably 5 N or more, and preferably 30 N or less, more preferably 20 N or less, still more preferably 15 N or less, the hydrogel structure according to any one of <1> to <13>.

[0068] <15>The content of the dispersed phase in the hydrogel structure is preferably 3% by mass or more, more preferably 13% by mass or more, still more preferably 20% by mass or more, still more preferably 30% by mass or more, still more preferably 40% by mass or more, and preferably 99% by mass or less, more preferably 90% by mass or less, still more preferably 80% by mass or less, still more preferably 70% by mass or less, still more preferably 60% by mass or less, and is the hydrogel structure according to any one of <1> to <14>.

[0069] <16>The second gelling agent used to obtain the second hydrogel is preferably a water-soluble non-crosslinked polymer, more preferably one or more selected from the group consisting of agar, carrageenan, gellan gum, xanthan gum, and high-methoxyl pectin, and still more preferably contains agar, and is the hydrogel structure according to any one of <1> to <15>.

[0070] <17>The gelling agents used to obtain the first hydrogel and the second hydrogel are the same, and are the hydrogel structure according to any one of <1> to <16>.

[0071] <18>The content of the second gelling agent in the dispersed phase is preferably 0.8% by mass or more, more preferably 1.0% by mass or more, still more preferably 1.2% by mass or more, and preferably 10% by mass or less, more preferably 8% by mass or less, still more preferably 6% by mass or less, and is the hydrogel structure according to any one of <1> to <17>.

[0072] <19>The first hydrogel and the second hydrogel have the same composition, and are the hydrogel structure according to any one of <1> to <18>.

[0073] <20>The average particle diameter of the dispersed phase is preferably 1 μm or more, more preferably 5 μm or more, still more preferably 10 μm or more, and preferably 5 mm or less, more preferably 3 mm or less, still more preferably 2 mm or less, and is the hydrogel structure according to any one of <1> to <19>.

[0074] <21>The breaking load of the dispersed phase is preferably 0.1 N or more, more preferably 1 N or more, still more preferably 5 N or more, and preferably 30 N or less, more preferably 20 N or less, still more preferably 15 N or less, and is the hydrogel structure according to any one of <1> to <20>.

[0075] <22>The content of the first gelling agent and the second gelling agent in the hydrogel structure is preferably 0.8% by mass or more, more preferably 1.0% by mass or more, still more preferably 1.2% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less, still more preferably 6% by mass or less, and is the hydrogel structure according to any one of <1> to <21>.

[0076] <23>The hydrogel structure according to any one of <1> to <22> further includes dispersed particles different from the dispersed phase dispersed in the continuous phase.

[0077] <24>The dispersed particles are a water-insoluble cosmetic component, and are the hydrogel structure according to <23>.

[0078] <25>The content of the dispersed particles in the hydrogel structure is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and is the hydrogel structure according to <23> or <24>.

[0079] <26>The average particle size of the dispersed particles is preferably 0.1 μm or more, more preferably 1 μm or more, still more preferably 5 μm or more, and preferably 100 μm or less, more preferably 50 μm or less, still more preferably 20 μm or less. The hydrogel structure according to any one of <23> to <25>.

[0080] <27>The average particle size of the dispersed particles is smaller than the average particle size of the dispersed phase. The hydrogel structure according to any one of <23> to <26>.

[0081] <28>The breaking load of the hydrogel structure is preferably 0.1 N or more, more preferably 0.3 N or more, still more preferably 0.5 N or more, and preferably 30 N or less, more preferably 20 N or less, still more preferably 15 N or less, still more preferably 10 N or less, still more preferably 5 N or less. The hydrogel structure according to any one of <1> to <27>.

[0082] <29>The ratio of the minimum value of the load after fracture to the breaking load of the hydrogel structure (minimum value of the load after fracture / breaking load) is preferably 0.2 or more, more preferably 0.33 or more. The hydrogel structure according to any one of <1> to <28>.

[0083] <30>The ratio of the minimum value of the load after fracture to the breaking load of the hydrogel structure (minimum value of the load after fracture / breaking load) is preferably 1 or less, more preferably 0.95 or less, still more preferably 0.9 or less. The hydrogel structure according to any one of <1> to <29>.

[0084] <31>The breaking strain rate of the hydrogel structure is preferably 1% or more, more preferably 3% or more, still more preferably 5% or more, and preferably 50% or less, more preferably 45% or less, still more preferably 40% or less, still more preferably 35% or less. The hydrogel structure according to any one of <1> to <30>.

[0085] <32>The hydrogel structure according to any one of <1> to <31>, wherein the shape of the hydrogel structure is preferably granular, more preferably spherical.

[0086] <33>The ratio of the maximum span of the hydrogel structure to the average particle diameter of the dispersed phase is preferably 1 or more, more preferably 5 or more, still more preferably 10 or more, preferably 50000 or less, more preferably 10000 or less, still more preferably 1000 or less, still more preferably 800 or less, still more preferably 700 or less. The hydrogel structure according to any one of <1> to <32>.

[0087] <34>A cosmetic composition containing the hydrogel structure according to any one of <1> to <33>.

[0088] <35>Use of the hydrogel structure according to any one of <1> to <33> as a cosmetic.

[0089] <36>A method for producing a hydrogel structure according to any one of <1> to <33>, wherein hydrogel particles serving as the dispersed phase of the second hydrogel are dispersed in a first gelling agent aqueous solution for forming a continuous phase of the first hydrogel, and then the first gelling agent aqueous solution is gelled.

[0090] <37>The first gelling agent and the second gelling agent used to obtain the first hydrogel and the second hydrogel are agar, and the temperature of the first gelling agent aqueous solution when dispersing the hydrogel particles is preferably not less than the freezing point of the first gelling agent aqueous solution and less than the melting point of the hydrogel particles, more preferably 40°C or more and 80°C or less, still more preferably 45°C or more and 75°C or less, still more preferably 50°C or more and 70°C or less. The method for producing a hydrogel structure according to <36>.

[0091] <38>A method for manufacturing a hydrogel structure, comprising dispersing a second hydrogel in an aqueous solution of a first gelling agent for forming a continuous phase of the first hydrogel, and then gelling the aqueous solution of the first gelling agent, wherein the temperature of the aqueous solution of the first gelling agent when dispersing the second hydrogel is equal to or higher than the freezing point of the aqueous solution of the first gelling agent and lower than the melting point of the second hydrogel.

Example

[0092] The following is a test evaluation of the hydrogel structure. The composition and test evaluation results of the hydrogel structure are shown in Tables 1 to 4.

[0093] (Test evaluation method) <Average particle size of hydrogel particles> Regarding the agar hydrogel particles that become the dispersed phase A, an appropriate amount was dispersed in deionized water, and then the volume-based average particle size was measured using a laser diffraction / scattering particle size distribution analyzer (LA-960 manufactured by Horiba, Ltd.). The measurement conditions were a refractive index of 1.2 and a number of trials N of 3 times. And the average value of the 3 trials was used as the data.

[0094] <Breaking load and breaking strain rate of the hydrogel structure> In order to compare the hardness and brittleness of the hydrogel structure, the continuous phase, and the dispersed phase A, the breaking load and the breaking strain rate were determined as indices.

[0095] Regarding the rectangular parallelepiped hydrogel structure, texture measurement was performed using a desktop physical property measuring instrument (TPU-2D manufactured by Yamaden Co., Ltd.), and the breaking load and the breaking strain rate were analyzed using the texture analysis software attached to the apparatus. The measurement conditions were as follows. And for the breaking load, the average value of 4 trials was used as the data. For the breaking strain rate, the average value of 4 trials was used as the data. In addition, using the aqueous solution of the first gelling agent and the aqueous solution of the second gelling agent, the breaking load of each of the continuous phase and the dispersed phase A was also determined.

[0096] Plunger: No.6 (φ8mm) ACCESSORY: L30 CLEARANCE: 2.0 mm (SET: 20 × 0.1 mm) SPEED: 2.5 mm / sec TIMES: 1 Number of test runs N: 4 Temperature: 25°C

[0097] <Evaluation of the Disintegration Physical Properties of Spherical Hydrogel Structures> Regarding the spherical hydrogel structure, texture measurement was carried out using a desktop physical property measuring instrument (TPU-2D manufactured by Yamaden Co., Ltd.), and the breaking load and breaking strain rate were analyzed using the texture analysis software attached to the device. The measurement conditions were as follows. And the minimum value of the load after breaking was read from the texture curve (compression distance - load curve) created by the texture analysis software, and using this value, the ratio of the minimum value of the load after breaking to the breaking load (minimum value of the load after breaking / breaking load) was calculated.

[0098] Plunger: No.1 (φ30 mm) ACCESSORY: L40 CLEARANCE: 0.3 mm (SET: 3 × 0.1 mm) SPEED: 1 mm / sec TIMES: 1 Number of test runs N: 1 Temperature: 25°C

[0099] <Evaluation of Disintegration Functionality> Regarding the spherical hydrogel structure, three panelists evaluated the feel when crushed on the palm on a five-point scale according to the following evaluation criteria. And the average score of the three sensory evaluations was obtained, and if it was 3 points or more, it was rated as A, if it was 2 points or more and less than 3 points, it was rated as B, and if it was less than 2 points, it was rated as C.

[0100] 5: Collapses uniformly 4: Collapses somewhat uniformly 3: Neither can be said 2: Collapses somewhat non-uniformly 1: Collapses non-uniformly

[0101] <Evaluation of Storage Stability> Regarding the spherical hydrogel structure, after arranging them flat in a sterilized petri dish and covering it, they were stored in a refrigerator at 4°C for 3 days. The mass of each hydrogel structure before and after storage was measured, and the shape retention rate was calculated from the mass change according to the following formula. The number of test runs N was 18. Then, the average value of the 18 tests was obtained, and if it was 90% or more, it was given an A evaluation, and if it was less than 90%, it was given a C evaluation. Shape retention rate (%) = (mass after storage / mass before storage) × 100

[0102] (Hydrogel structure) Hydrogel structures were prepared as in Examples 1 to 15 and Comparative Examples 1 to 4 below. As the agar, Ina agar CS-16A (manufactured by Ina Food Industry Co., Ltd., freezing point of 1.5 mass% aqueous solution = 34.5 to 36.5°C, melting point of 1.5 mass% aqueous gel = 86.0 to 90.0°C) was used.

[0103] <Examples 1 to 8 and Comparative Example 2> - Preparation of hydrogel particles - After putting 985 g of deionized water into a 2 L SUS beaker, while stirring it with a turbine blade having a diameter of 50 mm at a rotation speed of 400 rpm, 15 g of agar was added and dispersed. Then, the beaker was immersed in a water bath set at a temperature of 92°C and heated, and held at a temperature of 85 to 92°C for 15 minutes to dissolve the agar, thereby preparing a 1.5 mass% agar aqueous solution.

[0104] Subsequently, after cooling the obtained 1.5 mass% agar aqueous solution to 60°C for temperature adjustment, 500 mL of half of it was dispensed into a sprayer (Safety 3 battery-powered sprayer SSD-1 manufactured by Fujiwara Sangyo Co., Ltd.) with a tank capacity of 1 L as a second gel agent aqueous solution using agar as the second gel agent.

[0105] Then, a vinyl sheet was spread on the floor, and the 1.5 mass% agar aqueous solution was sprayed from a spray nozzle into the air above it and cooled and solidified to produce agar hydrogel particles that would become the dispersed phase A of the second hydrogel on the vinyl sheet.

[0106] - Preparation of hydrogel structure - Into a disposable cup with a volume of 100 mL, take the first gel agent aqueous solution for forming the continuous phase of the first hydrogel from the remaining 1.5 mass% agar aqueous solution with the liquid temperature maintained at 60°C so as to have the blending amounts of the continuous phase and the dispersed phase A described in the table. Then, put the hydrogel particles of agar heated to 60°C into it and disperse them with a spatula.

[0107] A part of the 1.5 mass% agar aqueous solution in which the hydrogel particles are dispersed is poured into the cavity of a mold that is a true sphere with a diameter of 17 mm, and the temperature of the mold is adjusted to 4°C and cooled for 1 hour to cause gelation, thereby producing the spherical hydrogel structure described in the table. The hydrogel structure is recovered by irradiating compressed air with an air duster (model CD-31ECO, manufactured by Sunwa Supply Co., Ltd.) at the interface with the mold to release the mold, and it is assumed that the shape of the obtained hydrogel structure is the same as the cavity of the mold. Therefore, it is assumed that the maximum cross dimension of the obtained spherical hydrogel structure is 17 mm.

[0108] Also, take 15 g each of the first gel agent aqueous solution, the second gel agent aqueous solution, and the 1.5 mass% agar aqueous solution in which the hydrogel particles are dispersed and place them in a balance dish (BD-2 manufactured by AS ONE Corporation) with a side length of 6 cm, and let them stand at room temperature for 1 hour to cause gelation. The obtained gels are shaped with a spatula to form rectangular parallelepiped gel structures with a length of 3 cm, a width of 3 cm, and a thickness of 4 mm, respectively.

[0109] <Example 9> A 1.5% by mass aqueous agar solution prepared in the same manner as in Example 1 was taken as the second gelling agent aqueous solution and placed in a vacuum emulsifying and dispersing machine (AD Homomixer 2M-05 type, manufactured by PRIMIX). While stirring it with the attached first stirring unit (Homomixer MARKII 2.5 type, manufactured by PRIMIX) and the second stirring unit (paddle mixer) at rotational speeds of 8000 rpm and 60 rpm respectively, it was ice-cooled and held at an internal temperature of 35°C or lower for 60 minutes to prepare agar hydrogel particles that would become the dispersed phase A of the second hydrogel. Then, using these hydrogel particles and a 1.5% by mass aqueous agar solution with the liquid temperature maintained at 60°C, a hydrogel structure as described in the table was prepared by the same operation as in Example 7.

[0110] <Example 10> A hydrogel structure as described in the table was prepared by the same operation as in Example 9, except that the rotational speed of the first stirring unit was set to 4000 rpm.

[0111] <Example 11> A 1.5% by mass aqueous agar solution prepared in the same manner as in Example 1 was taken in a dropper. While stirring 200 g of ice-cooled silicone oil (KF-96A-6CS(-G), manufactured by Shin-Etsu Silicone) with a turbine blade having a diameter of 50 mm at a rotational speed of 500 rpm, 50 g of the 1.5% by mass aqueous agar solution at 60°C was dropped from the dropper thereto to prepare agar hydrogel particles that would become the dispersed phase A of the second hydrogel in the silicone oil. Then, the silicone oil containing the hydrogel particles was classified by passing it through a stainless steel sieve (manufactured by Tokyo Screen) with an opening size of 500 μm, and the recovered hydrogel particles were washed with water to remove the silicone oil. Then, using these hydrogel particles and the remaining 1.5% by mass aqueous agar solution with the liquid temperature maintained at 60°C, a hydrogel structure as described in the table was prepared by the same operation as in Example 7.

[0112] <Example 12> A hydrogel structure as described in the table was prepared by the same operation as in Example 11, except that the silicone oil containing the hydrogel particles was classified by passing it through a stainless steel sieve (manufactured by Tokyo Screen) with an opening size of 1 mm.

[0113] <Example 13> After putting 288.75 g of deionized water into a 500 mL SUS beaker, while stirring it at 200 rpm with a turbine blade having a diameter of 50 mm, 6.75 g of agar and 4.5 g of a surfactant (NIKKOL SMT (sodium stearoylmethyl taurine), manufactured by Nikko Chemicals Co., Ltd.) were added and dispersed. Then, the beaker was immersed in a water bath set at a temperature of 92°C and heated to raise the temperature, and held at a temperature of 85 to 92°C for 15 minutes to dissolve the agar, thereby preparing a 2.25 mass% agar aqueous solution.

[0114] Subsequently, the obtained 2.25 mass% agar aqueous solution was cooled to 60°C for temperature adjustment, placed in an ultra-high-speed multi-stirring system (manufactured by Lab Revolution PRIMIX), and 100 g of silicone oil (KF-96A-6CS(-G), manufactured by Shin-Etsu Silicone Co., Ltd.) serving as dispersed particles B at 60°C was added thereto. These were stirred at 6000 rpm for 1 minute with an attached stirring unit (Homomixer MARKII2.5 type, manufactured by PRIMIX) to prepare a 2.25 mass% agar emulsion in which the silicone oil was dispersed. The volume-based average particle diameter of the silicone oil was 9 μm as measured using a laser diffraction / scattering particle size distribution measuring device (LA-960, manufactured by Horiba, Ltd.).

[0115] 75 g of the agar emulsion maintained at a liquid temperature of 60°C was taken into a 100 mL disposable cup, and 25 g of hydrogel particles of agar heated to 60°C prepared in the same manner as in Example 1 was added thereto and dispersed with a spatula. Then, using this, a hydrogel structure described in the table was produced by the same operation as in Example 7.

[0116] <Example 14> After putting 3860 g of deionized water into a 5 L SUS beaker, 140 g of agar was added and dispersed while stirring at 400 rpm with a turbine blade having a diameter of 50 mm. Then, the beaker was immersed in a water bath set at a temperature of 92°C and heated up, and held at a temperature of 85 to 92°C for 15 minutes to dissolve the agar, thereby preparing a 3.5 mass% agar aqueous solution.

[0117] Subsequently, the obtained 3.5% agar aqueous solution was held at 80°C and flowed through a rotary positive displacement single-axis eccentric screw pump (model Mono Pump 2NL10F, manufactured by Heishin Equipment Co., Ltd.) heated to 80°C with deionized water at an output of 95 Hz, and sprayed into a spray tank with a volume of 4 m 3 from a two-fluid nozzle (nozzle model number SUE45B, manufactured by Spraying Systems Co., Ltd.) and cooled and solidified to produce agar hydrogel particles that become the dispersed phase A of the second hydrogel. At this time, the spray flow rate was 12 kg / h, the air flow rate was 27 m 3 / h, and the air pressure was 0.4 MPa.

[0118] Then, using these hydrogel particles and a 1.5 mass% agar aqueous solution with the liquid temperature maintained at 60°C, a hydrogel structure described in the table was produced by the same operation as in Example 7.

[0119] <Example 15> A hydrogel structure described in the table was produced by the same operation as in Example 7, except that an agar aqueous solution having the same composition as the dispersed phase A described in the table was used to prepare the dispersed phase A.

[0120] <Comparative Example 1> A hydrogel structure of only the continuous phase was produced in the same manner as in Example 1, except that only a 1.5 mass% agar aqueous solution was used without adding hydrogel particles.

[0121] <Comparative Example 3> A hydrogel structure of only the continuous phase was produced in the same manner as in Comparative Example 1, except that a 0.5 mass% agar aqueous solution was used.

[0122] <Comparative Example 4> A hydrogel structure composed only of a continuous phase was prepared in the same manner as in Comparative Example 1, except that an aqueous agar solution of 3.0% by mass was used.

[0123] From the above experimental results, it was found that the hydrogel structure of the example of the present invention is superior to the hydrogel structure of the comparative example in terms of disintegrability and storage stability. On the other hand, it was found that a hydrogel structure without a dispersed phase of a second hydrogel dispersed in the continuous phase cannot ensure storage stability even if it reaches a disintegrability that allows use by reducing the breaking load (Comparative Example 3).

[0124] [Table 1]

[0125] [Table 2]

[0126] [Table 3]

[0127] [Table 4] [Industrial Applicability]

[0128] The present invention is useful in the technical fields of a hydrogel structure and a method for producing the same, a cosmetic composition containing the hydrogel structure, and use of the hydrogel structure as a cosmetic. [Explanation of Signs]

[0129] 10 Hydrogel structure 11 Continuous phase 12 Dispersed phase A 13 Dispersed particle B 14 Dispersed particle C

Claims

1. A hydrogel structure comprising a continuous phase of a first hydrogel and a dispersed phase of a second hydrogel dispersed in the continuous phase, wherein the ratio of the minimum value of the load after fracture to the fracture load (minimum value of the load after fracture / fracture load) is 0.1 or more, the gelling agent used to obtain the first hydrogel contains a water-soluble non-crosslinked polymer, and the gelling agent used to obtain the second hydrogel contains a water-soluble non-crosslinked polymer.

2. A hydrogel structure comprising a continuous phase of a first hydrogel and a dispersed phase of a second hydrogel dispersed in the continuous phase, wherein the mass ratio of the dispersed phase to the continuous phase (dispersed phase / continuous phase) exceeds 1 / 99, the gelling agent used to obtain the first hydrogel contains a water-soluble non-crosslinked polymer, and the gelling agent used to obtain the second hydrogel contains a water-soluble non-crosslinked polymer.

3. The hydrogel structure according to claim 1 or 2, wherein the maximum span is 500 μm or more and 40 mm or less.

4. The hydrogel structure according to any one of claims 1 to 3, wherein the gelling agent used to obtain the first hydrogel and the second hydrogel contains agar.

5. The hydrogel structure according to any one of claims 1 to 4, wherein the ratio of the maximum span of the hydrogel structure to the average particle diameter of the dispersed phase is 1 or more and 50000 or less.

6. The hydrogel structure according to any one of claims 1 to 5, wherein the average particle diameter of the dispersed phase is 1 μm or more and 5 mm or less.

7. The hydrogel structure according to any one of claims 1 to 6, wherein the fracture strain rate of the hydrogel structure is 50% or less.

8. The hydrogel structure according to any one of claims 1 to 7, wherein the fracture load of the hydrogel structure is 0.1 N or more and 30 N or less.

9. The hydrogel structure according to any one of claims 1 to 8, having a granular shape.

10. The hydrogel structure according to any one of claims 1 to 9, wherein the content of the first gelling agent, which is the gelling agent for forming the continuous phase in the continuous phase of the first hydrogel, is 0.8% by mass or more and 20% by mass or less.

11. The hydrogel structure according to any one of claims 1 to 10, wherein the content of the second gelling agent, which is a gelling agent for forming the dispersed phase in the dispersed phase of the second hydrogel, is 0.8% by mass or more and 10% by mass or less.

12. The hydrogel structure according to any one of claims 1 to 11, wherein the first hydrogel and the second hydrogel have the same composition.

13. The hydrogel structure according to any one of claims 1 to 12, wherein the ratio of the minimum value of the load after fracture to the fracture load (minimum value of the load after fracture / fracture load) is 1 or less.

14. The hydrogel structure according to any one of claims 1 to 13, wherein the mass ratio of the dispersed phase to the continuous phase (dispersed phase / continuous phase) is 99 / 1 or less.

15. A cosmetic composition containing the hydrogel structure according to any one of claims 1 to 14.

16. A method for producing a hydrogel structure according to any one of claims 1 to 14, A method for producing a hydrogel structure, comprising dispersing hydrogel particles that will form the dispersed phase of the second hydrogel in an aqueous solution of a first gelling agent for forming the continuous phase of the first hydrogel, and then gelling the aqueous solution of the first gelling agent.

17. A method for producing a hydrogel structure, comprising dispersing a second hydrogel in an aqueous solution of a first gelling agent for forming the continuous phase of the first hydrogel, and then gelling the aqueous solution of the first gelling agent, wherein the temperature of the aqueous solution of the first gelling agent when dispersing the second hydrogel is equal to or higher than the freezing point of the aqueous solution of the first gelling agent and lower than the melting point of the second hydrogel, The method for producing a hydrogel structure, wherein the gelling agent used to obtain the first hydrogel contains a water-soluble non-crosslinked polymer, and the gelling agent used to obtain the second hydrogel contains a water-soluble non-crosslinked polymer.

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