Colloidal crystal structure, bath additive, and method for producing a colloidal crystal structure

Abstract

The objective is to obtain a novel colloidal crystal structure that has any shape, exhibits good glossiness, is composed only of materials safe for the human body without the use of polymerization initiators or the like in its immobilization, and allows for the dispersion of colloidal particles in water after being placed in water. [Solution] The colloidal crystal structure 10 is a mixture of sugars that are soluble in water and have different molecular weights and / or molecular species, and comprises a mixed sugar 20 which is at least partially vitrified, and colloidal particles 30 which are immobilized by the mixed sugar 20.

Description

Technical Field

[0001] The present disclosure relates to a colloidal crystal structure, a bath agent, and a method for producing a colloidal crystal structure.

Background Art

[0002] Patent Document 1 discloses a resin composition in which colloidal crystals are fixed in an acrylamide resin. This resin composition is obtained using a photopolymerization initiator such as 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide] or benzophenone. Also, it is described that ornaments formed using this resin composition exhibit a good bleeding effect. Patent Document 2 describes a technique for obtaining edible colloidal crystals using a polymer compound having a three-dimensional network structure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventor of the present application has long been developing a material that exhibits luster derived from Bragg reflection from colloidal crystals using a material safe for the human body without using a polymerization initiator or a monomer for polymerization. The colloidal crystal structure as a luster material is desired to have various characteristics according to its use. For example, a technique of using a colloidal crystal structure as a bath agent has been studied. The colloidal crystal structure used as a bath agent is desired to have good luster of the colloidal crystals before being put into water and to be able to disperse colloidal particles in water after being put into water.

[0005] Furthermore, while the colloidal crystal structures previously manufactured by the present inventor were easy to form on flat surfaces, forming them on curved surfaces was difficult. However, when colloidal crystal structures are used as bath additives, any three-dimensional structure, such as tablet-shaped, ellipsoidal, or spherical, is desirable.

[0006] This invention has been made in view of the above-mentioned conventional circumstances, and aims to solve the problem of obtaining a novel colloidal crystal structure. [Means for solving the problem]

[0007] The colloidal crystal structure of this disclosure comprises a mixture of sugars that are soluble in water and have different molecular weights and / or molecular species, the mixture of sugars being at least partially vitrified, and colloidal particles immobilized by the mixture of sugars.

[0008] The bath additive of this disclosure comprises the above-described colloidal crystal structure.

[0009] The present disclosure provides a method for producing a colloidal crystal structure, which involves preparing a dispersion in which colloidal particles are dispersed in a solution of mixed sugars, which is a mixture of sugars that are soluble in water and have different molecular weights and / or molecular species; placing the dispersion into a mold; and vitrifying at least a portion of the mixed sugars while regularly arranging the colloidal particles within the mold, thereby immobilizing the colloidal particles with the mixed sugars. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of a colloidal crystal structure that exhibits gloss due to Bragg reflection. [Figure 2] This is a diagram illustrating the preparation and molding processes. [Figure 3] This diagram schematically shows the state of the dispersion during the initial stages of the maturation process. [Figure 4] This diagram schematically shows the state of the dispersion during the maturation process. [Figure 5]This diagram shows the demolding process and the process of combining two colloidal crystal structures to produce an ellipsoidal bath additive. [Modes for carrying out the invention]

[0011] Preferred embodiments of this disclosure will be described. The colloidal crystal structure of this disclosure may be free from polymerization initiators. In the method for manufacturing the colloidal crystal structure of this disclosure, the surface of the mold is hydrophobic, and the design surface of the colloidal crystal structure is formed in a shape that conforms to the surface of the mold.

[0012] The embodiment will be described in detail below. In this specification, when a numerical range is described using "-", it includes both the lower limit and the upper limit unless otherwise specified. For example, the description "10-20" includes both the lower limit "10" and the upper limit "20". In other words, "10-20" has the same meaning as "10 or more and 20 or less".

[0013] 1. Colloidal crystal structure 10 As shown in Figure 1, the colloidal crystal structure 10 of this embodiment comprises a mixture of sugars 20 which are soluble in water and are a mixture of sugars with different molecular weights and / or molecular species, and colloidal particles 30 immobilized by the mixture of sugars 20.

[0014] (1) Mixed sugars 20 Mixed sugars 20 is a mixture of sugars that are soluble in water and have different molecular weights and / or molecular species. In this specification, "sugars" includes monosaccharides, polysaccharides, sugar alcohols, and sugar derivatives. Monosaccharides include, for example, glucose, mannose, galactose, fructose, arabinose, ribose, and xylose. Polysaccharides are sugars formed by the polymerization of two or more monosaccharides. Polysaccharides can be classified mainly by their size. Polysaccharides include, for example, disaccharides, oligosaccharides, dextrins, and starches. Disaccharides are sugars formed by the polymerization of two monosaccharides. Oligosaccharides are sugars formed by the polymerization of three to ten monosaccharides. Dextrins are sugars obtained by hydrolyzing starch or glycogen and refer to sugars that are larger than oligosaccharides. Sugar alcohols are a type of sugar produced by the reduction of the carbonyl group of aldoses and ketoses. Sugar alcohols include, for example, erythritol, pentaerythritol, xylitol, sorbitol, and mannitol. Sugar derivatives are sugars that have been chemically modified with a functional group of their choice. For example, monosaccharides include glucuronic acid and glucosamine, while polysaccharides include starch acetate and oxidized starch.

[0015] The water-soluble mixed sugars 20 in this disclosure can maintain a solution state, for example, in the initial stages of the maturation process described later. The solubility of sugars in water is determined by factors such as molecular weight, presence or absence of side chains, and type and number of functional groups. The mixed sugars 20 can be vitrified in the later stages of the maturation process. In general, monosaccharides or disaccharides with a homogeneous molecular species tend to crystallize easily. From the viewpoint of promoting vitrification in the later stages of the maturation process, it is preferable that the mixed sugars 20 are not easily crystallized. Furthermore, the mixed sugars in this disclosure are preferably mixed sugars that exclude polysaccharides that are prone to gelation, for example, mixed sugars that exclude roasted bean gum, carrageenan, and agarose.

[0016] The mixed saccharides 20 are a mixture of saccharides having different molecular weights and / or molecular species from the viewpoint of immobilizing colloidal crystals while being vitrified. In particular, the mixed saccharides 20 preferably contain starch syrup and / or dextrin. Either starch syrup or dextrin alone may be used, or they may be used in combination. Starch syrup is a viscous saccharide obtained by saccharifying starch with an acid and / or a saccharifying enzyme. Starch syrup usually contains glucose (dextrose), maltose (malt sugar), oligosaccharides, and dextrin. Generally, starch syrup contains 70% to 90% by mass of water-soluble saccharides and the balance as water. Commercial products of starch syrup and / or dextrin can be appropriately used. In each figure, the mixed saccharides 20 are conceptually represented, and their size, arrangement, etc. may not be accurate.

[0017] From the viewpoint of light transmittance, in the colloidal crystal structure 10, most of the mixed saccharides 20 may be present in the state of a glass phase (amorphous phase). As described above, monosaccharides and disaccharides tend to crystallize easily. From the viewpoint of suppressing crystallization, the mixed saccharides 20 preferably contain one or more selected from the group consisting of oligosaccharides and dextrin, and more preferably are starch syrup.

[0018] (2) Colloidal particles 30 The colloidal particles 30 are not particularly limited as long as they can be immobilized by the mixed saccharides 20 to form the colloidal crystal structure 10. From the viewpoint of safety to the human body, the colloidal particles 30 are preferably selected from amorphous silica particles, iron oxide, calcium carbonate particles, etc.

[0019] From the viewpoint of preferably obtaining the diffraction wavelength in the visible light wavelength range, the average particle size of the colloidal particles 30 is preferably 100 nm or more and 300 nm or less. From the viewpoint of preferably forming colloidal crystals, the coefficient of variation in particle size is preferably 10% or less. The average particle size of the colloidal particles 30 can be measured, for example, by a particle size distribution measuring device. The coefficient of variation in the particle size of the colloidal particles 30 can be calculated based on the particle size distribution. For commercial products, catalog values may be adopted.

[0020] (3) Ratio of colloidal particles 30 to mixed saccharides 20 The ratio of colloidal particles 30 to mixed saccharides 20 (mass ratio of colloidal particles: mixed saccharides) in the dispersion liquid 11 at the initial stage of the aging process described below is preferably 25:20 - 25:3, more preferably 25:16 - 25:6, and still more preferably 25:14 - 25:9. The mass of the mixed saccharides 20 is the total amount of the mixed saccharides 20 when the total raw materials are 100 parts by mass.

[0021] (4) Other components The colloidal crystal structure 10 may contain other components as long as the effects of the present invention are not impaired. Appropriate chemicals used in bath agents may be used as the other components. Chemicals used in bath agents are, for example, collagen, hyaluronic acid, vitamin C, vitamin E, coloring agents, fragrances, etc. However, in order to prevent aggregation of the colloidal particles 30 and crystallization of the mixed saccharides 20, the addition amount of the chemicals used in bath agents may be appropriately adjusted. For example, in order to prevent aggregation of the colloidal particles 30, the addition amount of ionic additives should be kept to a very small amount or not added.

[0022] The colloidal crystal structure 10 preferably does not contain a polymerization initiator from the viewpoint of safety to the human body when it enters the mouth or eyes. A polymerization initiator is a compound used to initiate a polymerization reaction for synthesizing a polymer, and photoinitiators, thermal initiators, etc. are known. The colloidal crystal structure 10 of the present embodiment more preferably does not contain a polymer monomer for polymerization.

[0023] (5) Appearance and shape of the colloidal crystal structure 10 The appearance of the colloidal crystal structure 10, such as its color and gloss, is not particularly limited. The colloidal crystal structure 10 in the examples described later appears to have a luster like that of a pearl or opal. The appearance of the colloidal crystal structure 10 can be controlled, for example, by adjusting the type and average particle size of the colloidal particles 30. The colloidal crystal structure 10 can Bragg reflect light of a specific wavelength depending on the distance between the colloidal particles 30. For example, when amorphous silica particles are dispersed in a polar solvent such as water, the particle surfaces become charged with the same sign, and adjacent amorphous silica particles repel each other by electrostatic force. That is, by appropriately selecting the type and average particle size of the colloidal particles 30, the distance between the colloidal particles 30 can be adjusted, and light of a desired wavelength (e.g., visible light wavelength) can be Bragg reflected. The colloidal crystal structure 10 maintains its gloss even when stored at room temperature in the atmosphere.

[0024] The shape of the colloidal crystal structure 10 is not particularly limited. From the viewpoint of manufacturability, it is preferable that the surface of the colloidal crystal structure 10 in this embodiment is smooth. The surface of the colloidal crystal structure 10 is a design surface that exhibits the luster characteristic of colloidal crystals. The surface may be flat or curved. The thickness of the colloidal crystal structure 10 is not particularly limited and can be, for example, 10 mm or less, 5 mm or less, or 3 mm or less. The shape of the colloidal crystal structure 10 in plan view can be set as appropriate. For example, the colloidal crystal structure 10 may be circular, square, star-shaped, etc. in plan view, or it may be shaped like an animal such as a cat or dog.

[0025] The colloidal crystal structure 10 may be partially or entirely colored. In this case, if a colorant containing a large amount of ions is used, it will be difficult for the colloidal crystal to form, so it is appropriate to use a colorant that does not increase the ionic strength as much as possible.

[0026] 2. Bath additive 40 The bath additive 40 of this embodiment comprises a colloidal crystal structure 10. The bath additive 40 may be, for example, the colloidal crystal structure 10 itself. The bath additive 40 may comprise a base portion (not shown) containing bath additive components and a colloidal crystal structure 10 that decorates the surface of the base portion. That is, it is preferable that at least a portion of the design surface of the bath additive 40 is composed of the colloidal crystal structure 10. The bath additive 40 exhibits a pearl- or opal-like luster due to the luster of the colloidal crystals. The technology of this disclosure is groundbreaking in that it is possible to produce a lustrous bath additive 40 without using metals such as gold leaf or silver leaf.

[0027] The shape of the bath additive 40 is not particularly limited. The bath additive 40 may be formed into a larger three-dimensional shape by appropriately combining a plurality of colloidal crystal structures 10. For example, as shown in Figure 5, two flattened dome-shaped colloidal crystal structures 10, 10 may be combined to form a bath additive 40 having a Go stone-like or spherical three-dimensional shape. Two disc-shaped colloidal crystal structures may be combined to form a bath additive having a coin-shaped three-dimensional shape. The colloidal crystal structures 10 can be bonded together, for example, by the tackiness of the mixed sugars 20. The non-designed surface of the colloidal crystal structure 10 immediately after manufacturing is slightly sticky due to the mixed sugars 20. When the non-designed surfaces of the colloidal crystal structures 10 in this state are brought together, the colloidal crystal structures 10 can be bonded together without using an adhesive.

[0028] Bath additive 40 is used by dissolving the colloidal crystal structure 10 in water, for example, like a so-called bath bomb or bath ball. When the colloidal crystal structure 10 dissolves in water, the colloidal particles 30 disperse in the water and cause it to become cloudy. In other words, the colloidal crystal structure 10 is suitable as a bath additive 40 for creating cloudy bathwater.

[0029] Bath additives 40 using mixed sugars 20 tend to dissolve more slowly in water than commercially available bath additives using inorganic salts, etc. However, the dissolution rate of the colloidal crystal structure 10 can be controlled by adjusting the type and mixing ratio of the mixed sugars 20 and colloidal particles 30. Even if the dissolution rate of the colloidal crystal structure 10 is slow, one can still enjoy the process of the colloidal crystal structure 10 dissolving by rubbing its surface with their fingers.

[0030] 3. Method for producing the colloidal crystal structure 10 An example of a method for producing the colloidal crystal structure 10 is described below. In this embodiment, the method for producing the colloidal crystal structure 10 involves preparing a dispersion 11 by dispersing colloidal particles 30 in a mixture of sugars 20 which are soluble in water and are a mixture of sugars with different molecular weights and / or molecular species (hereinafter also referred to as the preparation step), placing the dispersion 11 into a mold 13 (hereinafter also referred to as the molding step), and while arranging the colloidal particles 30 regularly within the mold 13, vitrifying at least a portion of the mixture of sugars 20 to fix the colloidal particles 30 with the mixture of sugars 20 (hereinafter also referred to as the maturation step). Note that the method for producing the colloidal crystal structure 10 may include other steps besides those described above.

[0031] (1) Preparation process As shown in Figure 2, in the preparation step, a dispersion 11 is prepared in which colloidal particles 30 are dispersed in a solution of mixed sugars 20. The solution of mixed sugars 20 is, for example, a concentrated aqueous solution of mixed sugars 20. In the preparation step, the solution of mixed sugars 20 and the colloidal particles 30 are mixed so that the mass ratio of mixed sugars 20 to colloidal particles 30 is a predetermined mass ratio. At this time, the hardness of the resulting colloidal crystal structure 10 may be adjusted by adjusting the amount of dextrin in the mixed sugars 20 and the amount of additives added to the dispersion 11. However, the ionic strength in the dispersion 11 should be as low as possible.

[0032] (2) Molding process First, a mold 13 is prepared. By molding the colloidal crystal structure 10 using the mold 13, the colloidal crystal structure 10 can be formed as intended, according to the surface shape of the mold 13. The surface 13A of the mold 13 is preferably hydrophobic. A mold (container) made of silicone resin is preferred as such a mold 13. The surface 13A of the mold 13 is the surface that contacts the design surface of the colloidal crystal structure 10. Furthermore, it is preferable that the mold 13 be flexible in order to facilitate demolding and to suppress the collapse of the colloidal crystal structure 10 during demolding. From the viewpoint of suppressing the growth of bacteria during the maturation process, it is preferable that the mold 13 be sterilized before use.

[0033] The prepared dispersion 11 is poured into the mold 13. The molding process is preferably carried out in a clean bench from the viewpoint of suppressing the growth of bacteria. In Figure 2, the square frame surrounding the diagram showing the pouring of the dispersion 11 into the mold 13 represents the clean bench or a simple enclosure to prevent the intrusion of dust and bacteria. The preferred height (depth) of the dispersion 11 in the mold 13 is 1 mm to 10 mm. In the molding process, the mold 13 containing the dispersion 11 is preferably covered with a cover 15 such as plastic wrap. Depending on whether or not the cover 15 is used and the gap between the cover 15 and the mold 13, the evaporation rate of water in the subsequent maturation process can be controlled.

[0034] (3) Aging process As shown in Figures 3 and 4, the maturation process involves regularly arranging colloidal particles 30 within the mold 13, vitrifying at least a portion of the mixed sugars 20, and immobilizing the colloidal particles 30 with the mixed sugars 20. The maturation process is mainly a process of constructing colloidal crystals through the crystallization of colloidal particles 30 and the evaporation of the dispersion medium (water) containing the mixed sugars 20, which vitrifies the mixed sugars 20 (immobilizing the colloidal crystals).

[0035] The maturation process is preferably carried out by leaving the dispersion 11 undisturbed in an environment with minimal vibration. The temperature of the maturation process should be set to, for example, 10°C to 25°C. The duration of the maturation process can be appropriately set according to the size of the colloidal crystal structure 10 itself, the maturation temperature, the amount of dispersion medium (water) in the dispersion 11, etc. The maturation process duration can be set to, for example, 1 month to 4 months. By slowing down the evaporation rate of the dispersion medium (water) and, for example, providing a maturation process duration of 1 month or more, it is possible to avoid the immobilization of unaligned colloidal particles 30 and allow the colloidal crystals to grow sufficiently. Furthermore, by adjusting the above-mentioned maturation temperature and the evaporation rate of the dispersion medium (water), the mixed sugars 20 can be suitably vitrified. The end point of the maturation process may also be determined after confirming that the colloidal crystal structure 10 has hardened sufficiently.

[0036] During the maturation process, the refractive index of the dispersion 11 may be approximately the same as that of the dispersion medium and the colloidal particles 30. Specifically, in the initial stages of the maturation process, the dispersion 11 is cloudy. However, as the dispersion medium evaporates and the refractive index of the dispersion medium and the refractive index of the colloidal particles 30 become approximately the same, the dispersion 11 tends to become more transparent. In the dispersion 11, which has become more transparent due to refractive index assimilation, theoretically, the attractive force between colloidal particles weakens, and the dispersibility of the colloidal particles 30 increases. Increased dispersibility makes it easier to optimize the position of the colloidal particles 30. This effect is presumed to be useful in constructing the colloidal crystal structure 10 of this disclosure.

[0037] Thus, the maturation process is preferable in which the colloidal particles 30 are arranged regularly to allow sufficient growth of colloidal crystals, while the crystalline structure of the colloidal particles 30 is fixed by utilizing the glass phase transition of the mixed sugars 20.

[0038] Furthermore, during the maturation process, it is preferable to form the design surface of the colloidal crystal structure 10 in a shape that conforms to the surface 13A of the mold 13. The surface of the colloidal crystal structure 10 that was in contact with the surface 13A of the mold 13 has particularly good gloss and is suitable for the design surface of the colloidal crystal structure 10. In addition, by forming the design surface of the colloidal crystal structure 10 in a shape that conforms to the surface 13A of the mold 13, the degree of freedom in the shape of the colloidal crystal structure 10 can be improved.

[0039] (4) Demolding process (optional process) The method for manufacturing the colloidal crystal structure 10 involves, for example, removing the colloidal crystal structure 10 from the mold 13. If a flexible mold 13 is used, the colloidal crystal structure 10 should be carefully removed while deforming the mold 13, taking care not to apply any unnecessary external force to it. The removed colloidal crystal structure 10 can be used as is, or in combination with other structures, as a bath additive 40 (see Figure 5). In this way, the colloidal crystal structure 10 and the bath additive 40 containing the colloidal crystal structure 10 are manufactured.

[0040] 4. Operation and Effects of this Embodiment The colloidal crystal structure 10 of this embodiment comprises a mixture of sugars 20 that are soluble in water and have different molecular weights and / or molecular species, and at least a portion of which are vitrified, and colloidal particles 30 immobilized by the mixture of sugars 20. The inventors of the present invention have been investigating the use of the colloidal crystal structure 10 as a bath additive. In the process, they found that there are the following problems when using the colloidal crystal structure 10 as a bath additive. First, the conventional colloidal crystal structure described in Patent Document 2 was too hard and did not dissolve in water at a suitable temperature for bathing. Also, the conventional colloidal crystal structure adhered too strongly to the mold and could not be easily removed from the mold. Furthermore, it was difficult to manufacture the conventional colloidal crystal structure in a curved shape such as a sphere. To overcome these problems, the inventors have found that the above problems can be overcome by using the mixture of sugars 20 as a material that has high affinity with the colloidal particles 30 and tends to vitrify, by using a mold 13 suitable for the mixture of sugars 20, and by slowing down the rate of water evaporation in the colloidal crystal structure 10. The colloidal crystal structure 10 described above uses materials that are highly safe for the human body, possesses good luster, and is easily soluble in water. Such a colloidal crystal structure 10 is useful as a bath additive 40 and is suitable for various other applications. This disclosure shall not be limited by the development history described above.

[0041] The colloidal crystal structure 10 of this embodiment does not contain a polymerization initiator. Although polymerization initiators are commonly used in colloidal crystals with good gloss, there are concerns regarding their safety to the human body if they come into contact with the mouth or eyes. This embodiment is highly useful because it allows for the production of colloidal crystals with good gloss without the use of a polymerization initiator.

[0042] Bath additive 40 is equipped with a colloidal crystal structure 10. According to bath additive 40, the structural color of the colloidal crystal has the potential to contribute to the creation of a new bathing culture. Traditionally, bath bombs and bath balls, known as bath additives, are sold for their novel appearance and colorfulness before dissolving, and are also used as souvenirs and toys. The colloidal crystal structure 10 is useful as bath additive 40 because of its appearance before dissolving and its iridescent luster. Furthermore, when the colloidal crystal structure 10 dissolves in water, the colloidal particles 30 disperse in the water and become cloudy. Bath additive 40 equipped with the colloidal crystal structure 10 can also be described as a bath additive that transforms from a sparkling solid into a cloudy liquid, allowing users to enjoy this transformation while bathing.

[0043] The method for producing the colloidal crystal structure 10 of this embodiment involves preparing a dispersion 11 in which colloidal particles 30 are dispersed in a mixture of sugars 20, which is a mixture of sugars soluble in water and having different molecular weights and / or molecular species; placing the dispersion 11 into a mold 13; and vitrifying at least a portion of the mixture of sugars 20 while regularly arranging the colloidal particles 30 within the mold 13, thereby immobilizing the colloidal particles 30 with the mixture of sugars 20. According to this method for producing the colloidal crystal structure 10, it is possible to produce a colloidal crystal structure 10 that has good gloss and is easily soluble in water, using materials that are highly safe for the human body.

[0044] In this embodiment, the surface 13A of the mold 13 is hydrophobic, and the design surface of the colloidal crystal structure 10 is formed in a shape that conforms to the surface 13A of the mold 13. In this way, a colloidal crystal with suitable gloss can be obtained, and it is also easy to remove it from the mold 13. [Examples]

[0045] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples.

[0046] 1. Fabrication of colloidal crystal structures To prepare the colloidal crystal structure in the example, the following raw materials and molds were prepared. Mixed sugars: Corn syrup (a mixture of glucose, maltose, oligosaccharides, dextrin, etc.), water-soluble sugar content 75% by mass, manufactured by Sudo Jam Co., Ltd., product name: corn syrup, product number: 130151. • Colloidal particles: Dispersion of silica microparticles (highly monodispersible spherical amorphous silica particles, average particle size 251.4 nm, coefficient of variation (CV value) of particle size 2.9% or less) (34.0% by mass), manufactured by Fuji Chemical Co., Ltd., product name: Howtform Silbol-EX250. • Type: A flexible silicone resin container with a hydrophobic surface, forming a tart cake mold, manufactured by Martellato, part number SF014.

[0047] 338g of the above silica particle dispersion, 72g of corn syrup, and 23g of pure water were mixed. The pure water was added to account for the evaporation of water during the subsequent boiling process. The mixture was heated to a boil for 10 minutes while stirring to prepare dispersion A, in which silica particles were dispersed in the corn syrup solution. Dispersion A was cloudy. Dispersion A was poured into a mold in a clean bench. The amount of dispersion A was adjusted so that the liquid height was 6mm. The mold was then covered with plastic wrap, leaving a gap.

[0048] Dispersion A, placed in a mold, was aged in a cool, dark place (10°C) for two months. During the aging process, dispersion A, which was initially cloudy, became clear. Subsequently, the water in dispersion A was evaporated until the corn syrup solidified. The solidified colloidal crystal structure was removed from the mold. Thus, a colloidal crystal structure was obtained.

[0049] 2. Observation The obtained colloidal crystal structure was observed visually. The colloidal crystal structure appeared to have a luster similar to that of a pearl or opal. When the colloidal crystal structure was stored at room temperature, its luster was maintained. Even when stored at room temperature, it did not change visually for several months, and no mold grew on it.

[0050] The colloidal crystal structure possessed shape retention properties suitable for use in bath additives. When the colloidal crystal structure was placed in 40°C water, it gradually dissolved, becoming a cloudy white liquid. When the colloidal crystal structure was rubbed with a finger in the water, the dissolution rate increased. The colloidal crystal structure possessed solubility suitable for use in bath additives.

[0051] 3. Effects of the Examples According to this embodiment, a novel colloidal crystal structure was obtained in which the colloidal crystal exhibits good gloss and, after being placed in water, the colloidal particles can be dispersed in the water.

[0052] The present invention is not limited to the embodiments detailed above, and various modifications or changes are possible within the scope of the claims of this disclosure. [Explanation of Symbols]

[0053] 10...Colloidal crystal structure, 11...Dispersion, 13...Type, 13A...Surface, 20...Mixed sugars, 30...Colloidal particles, 40...Bath additive

Claims

1. A mixture of sugars that are soluble in water and have different molecular weights and / or molecular species, comprising at least a portion of which are vitrified mixed sugars, A colloidal crystal structure comprising colloidal particles immobilized by the aforementioned mixed sugars.

2. A colloidal crystal structure according to claim 1, which does not contain a polymerization initiator.

3. A bath additive comprising the colloidal crystal structure described in either claim 1 or claim 2.

4. Prepare a dispersion in which colloidal particles are dispersed in a solution of mixed sugars, which are a mixture of sugars that are soluble in water and have different molecular weights and / or molecular species. The dispersion is poured into a mold. A method for producing a colloidal crystal structure, comprising regularly arranging the colloidal particles within the mold, vitrifying at least a portion of the mixed sugars, and immobilizing the colloidal particles with the mixed sugars.

5. A method for producing a colloidal crystal structure according to claim 4, The surface of the aforementioned type is hydrophobic. A method for manufacturing a colloidal crystal structure, comprising forming the design surface of the colloidal crystal structure in a shape that conforms to the surface of the mold.

Images