Water-discoloring body, water-coloring body set

Abstract

To provide a water-discoloring body and a water-discoloring body set capable of forming a desired image on the water-discoloring material by partially controlling the water-absorbing state and dry state of the porous layer in the cover material by covering the water-discoloring material that has absorbed water by pouring water onto the porous layer, with the cover material.SOLUTION: Provided are: a water-discoloring body 1 including a porous layer 5, which is formed on the upper layer of a colored layer 4 and in which a low refractive index pigment is fixed in a dispersed state in a binder resin, and a cover material which delays the drying of water absorbed by the porous layer of the water-discoloring material, the cover material having a cloth 8 made of water-absorbent fiber provided on a part of an inner surface of a substrate 7; and a water-discoloring body set including the water-discoloring body and a water adhesion tool.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a water-discoloring body and a water-discoloring body set. More specifically, the present invention relates to a water-discoloring body and a water-discoloring body set that include a water-discoloring material and a cover material that controls the drying of water attached to the water-discoloring material. [Background technology]

[0002] Conventionally, a water-discoloring sheet has been disclosed in which a porous layer in which a low refractive index pigment that is opaque in a non-water-absorbing state and becomes transparent in a water-absorbing state is fixed in a dispersed state in a binder resin is disposed on a colored layer, and a water-discoloring material set has been disclosed in which the water-discoloring image is formed by applying water to the image with a writing or stamping tool, a finger, or the like, and immediately after the water-discoloring image is formed, the image is covered with a cover member, thereby extending the maintenance time of the water-discoloring image (see, for example, Patent Document 1). The water-discoloring material set can extend the time for which the water-discoloring image is maintained, and can satisfy the practicality of toys and teaching tools. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-254547 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide an unexpected water-discoloring material and a water-discoloring material set capable of controlling the water absorption and dryness states of the porous layer and forming a desired image by covering this type of water-discoloring material with a porous layer that has absorbed water with a cover material. [Means for solving the problem]

[0005] The present invention requires a water-discoloring material comprising a porous layer, in which a low refractive index pigment is fixed in a dispersed state in a binder resin, on top of a colored layer, and a cover material that delays the drying of water absorbed by the porous layer of the water-discoloring material, the cover material being characterized in that a cloth made of water-absorbent fibers is provided on a portion of the inner surface of the substrate. Further requirements include that the substrate is opaque, that the covering material has a peripheral portion on the underside of the substrate that is in close contact with the surface of the water-discoloring material and a void portion that keeps the inner peripheral portion out of contact with the surface of the water-discoloring material, that the substrate is a cylindrical body with one or both ends open, that the fabric of the covering material and the porous layer of the water-discoloring material are not in contact, and that the substrate is made up of a plurality of the water-discoloring materials and a plurality of the covering materials. Furthermore, the present invention requires a water-discoloring body set comprising the water-discoloring body and a water-attaching tool. Effect of the Invention

[0006] The present invention provides a water-discoloring material and a water-discoloring material set that satisfy marketability and practicality as a toy or teaching tool, by covering a water-discoloring material that has been made water-absorbent by adhering water to a porous layer with a cover material, thereby partially controlling the water absorption state and dry state of the porous layer within the cover material and forming a desired image on the water-discoloring material. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a longitudinal sectional view of a water-discoloring material according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a longitudinal sectional view illustrating a cover material according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a longitudinal sectional view of a water-color changing material and a cover material according to an embodiment of the present invention. [Figure 4] FIG. 2 is a longitudinal sectional view illustrating a water-discoloring material according to another embodiment of the present invention. [Diagram 5] FIG. 11 is an explanatory vertical cross-sectional view of a cover material according to another embodiment of the present invention. [Figure 6] FIG. 13 is a longitudinal sectional view of a water-color changing material and a cover material according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The water discoloring material is formed by providing a porous layer on a colored layer, the porous layer being made of a low refractive index pigment fixed in a dispersed state in a binder resin. The support itself may serve as the colored layer, but it is preferable to provide a colored layer (including an image of any shape) on the surface of the support. The support may be made of paper, synthetic paper, fabric such as woven fabric, knitted fabric, braided fabric, or nonwoven fabric, natural or synthetic leather, plastic, glass, ceramics, metal, wood, stone, etc. The support is preferably flat in shape, but may also be uneven. The colored layer provided on the surface of the support is formed from a binder resin containing a colorant. Examples of the colorant include general dyes, general pigments, fluorescent dyes, fluorescent pigments, and metallic luster pigments. The colorant is contained in a vehicle containing a binder resin as a binding agent, and the ink or paint is applied to a support, and then the volatile components are dried to form a colored layer. Examples of the binder resin include urethane resins, nylon resins, vinyl acetate resins, acrylic ester resins, acrylic ester copolymer resins, acrylic polyol resins, vinyl chloride-vinyl acetate copolymer resins, maleic acid resins, polyester resins, styrene resins, styrene copolymer resins, polyethylene resins, polycarbonate resins, epoxy resins, styrene-butadiene copolymer resins, acrylonitrile-butadiene copolymer resins, methyl methacrylate-butadiene copolymer resins, butadiene resins, chloroprene resins, melamine resins, and emulsions of each of the above resins, casein, starch, cellulose derivatives, polyvinyl alcohol, urea resins, and phenol resins. The colored layer is formed on the support by a printing means such as process printing, screen printing, offset printing, gravure printing, coater, pad printing, inkjet printing, transfer printing, etc., brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, dip coating, etc. Alternatively, a transfer layer can be provided by first applying an ink or paint contained in a vehicle containing a colorant and a binder resin as a binder onto a separate substrate, and then transferring the transfer layer onto the support to provide a colored layer. Furthermore, when the support has transparency, a colored layer can be provided on the back surface of the support (the surface on which the porous layer is not provided).

[0009] A porous layer in which a low refractive index pigment is fixed in a dispersed state by a binder resin is laminated on the colored layer to obtain a water-discoloring material. The porous layer is a layer in which a low refractive index pigment is fixed in a dispersed state together with a binder resin, and has a different transparency in a dry state and in a liquid-absorbed state. Examples of the low refractive index pigment include silicic acid and its salts, baryte powder, barium sulfate, barium carbonate, calcium carbonate, gypsum, clay, talc, alumina white, magnesium carbonate, etc., which have a refractive index in the range of 1.4 to 1.8 and exhibit good transparency when absorbing water. Examples of the salt of silicic acid include aluminum silicate, potassium aluminum silicate, sodium aluminum silicate, calcium aluminum silicate, potassium silicate, calcium silicate, sodium calcium silicate, sodium silicate, magnesium silicate, and potassium magnesium silicate. An example of a low refractive index pigment that is preferably used is silicic acid. Two or more of the low refractive index pigments can be used in combination. The particle size of the low refractive index pigment is not particularly limited, but a particle size of 0.03 to 10.0 μm is preferably used. The silicic acid may be silicic acid produced by a dry method, but silicic acid produced by a wet method (hereinafter referred to as wet method silicic acid) is particularly effective. In this regard, silicic acid is produced as amorphous silicic acid, and depending on the production method, it is roughly divided into a dry method using a gas phase reaction such as thermal decomposition of silicon halide such as silicon tetrachloride (hereinafter referred to as dry method silicic acid) and a wet method using a liquid phase reaction such as decomposition with an acid such as sodium silicate. The dry method silicic acid and the wet method silicic acid have different structures, and the dry method silicic acid forms a three-dimensional structure in which silicic acid is densely bonded, while the wet method silicic acid has a so-called two-dimensional structure in which silicic acid is condensed to form a long molecular arrangement. Therefore, since the molecular structure is coarser than that of the dry process silicic acid, it is presumed that when wet process silicic acid is applied to a porous layer, it has superior diffuse reflection of light in a dry state and has greater hiding power in the normal state than a system using dry process silicic acid. In addition, since the porous layer is capable of absorbing water, wet-process silicic acid has more hydroxyl groups present as silanol groups on the particle surface than dry-process silicic acid and has a higher degree of hydrophilicity, and is therefore preferably used. In order to adjust the hiding power of the porous layer in a normal state and the transparency in a liquid-absorbed state, other low refractive index pigments can be used in combination with the wet-process silica.

[0010] The low refractive index pigment in the porous layer depends on the properties such as particle size, specific surface area, and oil absorption, but in order to satisfy both the hiding power in a normal state and the transparency in a liquid-absorbed state, the coating amount is set to 1 to 50 g / m. 2 It is preferable that the thickness is 5 to 50 g / m 2 1g / m 2 If it is less than 50 g / m, it is difficult to obtain sufficient hiding power under normal conditions. 2 If it exceeds this value, it becomes difficult to obtain sufficient transparency when absorbing liquid. The low refractive index pigment is dispersed in a vehicle containing a binder resin as a binding agent, and after being coated on a support, the volatile content is dried to form a porous layer. Examples of the binder resin include urethane resins, nylon resins, vinyl acetate resins, acrylic ester resins, acrylic ester copolymer resins, acrylic polyol resins, vinyl chloride-vinyl acetate copolymer resins, maleic acid resins, polyester resins, styrene resins, styrene copolymer resins, polyethylene resins, polycarbonate resins, epoxy resins, styrene-butadiene copolymer resins, acrylonitrile-butadiene copolymer resins, methyl methacrylate-butadiene copolymer resins, butadiene resins, chloroprene resins, melamine resins, and emulsions of each of the above resins, casein, starch, cellulose derivatives, polyvinyl alcohol, urea resins, and phenol resins. The mixing ratio of the low refractive index pigment and the binder resin depends on the type and properties of the low refractive index pigment, but is preferably 0.5 to 2 parts by mass, more preferably 0.8 to 1.5 parts by mass, of binder resin solid content per part by mass of the low refractive index pigment. If the binder resin solid content per part by mass of the low refractive index pigment is less than 0.5 parts by mass, it is difficult to obtain a practical film strength of the porous layer, and if it exceeds 2 parts by mass, the permeability of water into the porous layer is easily impaired. The porous layer has a smaller mixing ratio of binder resin to colorant than a general coating film, so it is difficult to obtain sufficient film strength. Therefore, in order to increase the abrasion resistance, it is effective to use a nylon resin or a urethane resin among the binder resins. The urethane resin may be a polyester urethane resin, a polycarbonate urethane resin, a polyether urethane resin, etc., and two or more of them may be used in combination. In addition, a urethane emulsion resin in which the resin is emulsified and dispersed in water, or a colloidal dispersion type (ionomer type) urethane resin in which the urethane resin (urethane ionomer) having ionic properties is self-emulsified without the need for an emulsifier due to the ionic group of the resin itself, and dissolved or dispersed in water, may be used. The urethane resin may be either an aqueous urethane resin or an oil-based urethane resin, but an aqueous urethane resin, particularly an urethane emulsion resin or a colloidal dispersion type urethane resin, is preferably used. The urethane resin can be used alone, but can also be used in combination with other binder resins depending on the performance required for the film. When a binder resin other than the urethane resin is used in combination, in order to obtain a practical film strength, it is preferable that the binder resin of the porous layer contains the urethane resin in an amount of 30% or more by solid mass ratio. In the above-mentioned binder resin, if it is crosslinkable, the strength of the film can be further improved by adding an arbitrary crosslinking agent to crosslink the binder resin. The binder resin has a large or small affinity with water, and by combining these, it is possible to adjust the time for penetration into the porous layer, the degree of penetration, and the drying speed after penetration. Furthermore, the above adjustment can be controlled by adding a dispersant or a surfactant as appropriate.

[0011] The porous layer can be formed on the colored layer by printing means such as screen printing, offset printing, gravure printing, coater, pad printing, transfer printing, brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, dip coating, or the like.

[0012] A colorant may be added to the porous layer to color the porous layer in a dry state. Examples of the colorant include general dyes, general pigments, fluorescent dyes, fluorescent pigments, metallic luster pigments, reversible thermochromic compositions, reversible thermochromic microcapsule pigments encapsulating reversible thermochromic compositions, photochromic compositions, and photochromic microcapsule pigments encapsulating photochromic compositions. When fluorescent colorants such as fluorescent dyes and fluorescent pigments are used, the clarity of color change is excellent. When photochromic colorants such as thermochromic colorants such as reversible thermochromic compositions and reversible thermochromic microcapsule pigments encapsulating reversible thermochromic compositions, photochromic colorants, photochromic compositions, and photochromic microcapsule pigments encapsulating photochromic compositions are used, a variety of changes can be imparted. As the reversible thermochromic composition, a reversible thermochromic composition containing three components, an electron donating organic color-forming compound, an electron accepting compound, and an organic compound medium that reversibly induces a color-forming reaction, is preferably used. As the photochromic composition, photochromic compounds such as spirooxazine compounds, spiropyran compounds, and diarylethene compounds are preferably used.

[0013] The cover material for covering the water-discoloring material having the porous layer in a water-absorbent state will now be described. The base material constituting the cover material is made of a plastic sheet material, a plastic molded body, glass, or the like. The shape of the cover material can be such that the peripheral portion of the underside of the substrate is in close contact with the surface of the water-discoloring material, and the inner side of the peripheral portion has a void portion that keeps it out of contact with the surface of the water-discoloring material, and the void portion can prevent the water absorbed by the porous layer from drying out. Alternatively, the cover material may be a cylindrical body with one or both ends open, and by inserting the water-discoloring material through the opening and forming a void between the inner surface of the substrate of the cover material and the porous layer of the water-discoloring material in this state, it is possible to prevent the water absorbed in the porous layer from drying out. The height of the void portion is 0.4 mm to 12.0 mm, preferably 0.5 mm to 10.0 mm, so that the space between the porous layer and the substrate can have a good function of preventing water from drying. If the height is less than 0.4 mm, the porous layer is likely to come into contact with the substrate, and water adheres to the substrate, making it difficult to satisfy the practicality of repeated use, whereas if the height exceeds 12.0 mm, it becomes difficult to exhibit the effect of suppressing the drying of water. The substrate is preferably opaque in order to make the process of forming an image on the water-discolorable material invisible to the naked eye and to provide an element of surprise. Furthermore, since the base material has flexibility, application and removal of the cover material can be facilitated.

[0014] The inner surface of the base material forming the cover material is partially provided with a cloth made of water-absorbent fibers. The absorbent fibers may be natural fibers such as cotton, hemp, silk, wool, or synthetic fibers as long as they have absorbent properties. Natural and synthetic fibers may also be used in combination. The shape of the fabric is not particularly limited, and examples include various letters, symbols, figures, patterns, as well as people, animals, plants, fruits, food products, vehicles, buildings, celestial bodies, and the like. The fabric can absorb the water absorbed in the porous layer of the water-discoloring material and cause the porous layer to partially dry (become non-water-absorbent), thereby forming a dry image in the shape of the fabric in the porous layer. The fabric and the porous layer may be in contact or not in contact with each other. However, in the case of a structure in which a water-discoloring material is inserted into a cover material, for example, a cover material consisting of a cylindrical body with one or both ends open, it is preferable that the fabric and the porous layer are not in contact with each other, so that a clear image can be formed.

[0015] Furthermore, by making the water-colorable body consist of a plurality of water-colorable materials and a plurality of cover materials, an image can be formed on another water-colorable material before the image disappears, so that the desired image can be formed quickly. Furthermore, by using fabrics of multiple cover materials with different shapes, different images can be formed on the water-colorable material, improving playability.

[0016] As a means for applying water to the water-discoloring material, a water application tool can be used in addition to contacting the material with wet hands or fingers. Examples of the water application tool include water guns, sprayers, writing or application tools having a brush tip or fiber pen body at the tip, writing or application tools that hold water in a container and have a fiber body or brush that expels the water from the container, stamp tools, and the like. In addition, a water-discoloring object set can be constructed by combining the water-adhering tool and the water-discoloring object, and can be used as a highly convenient teaching tool set or drawing toy set. EXAMPLES

[0017] The following examples are provided, but the present invention is not limited to these examples. In the examples, "parts" refers to parts by weight. Example 1 Preparation of hydrochromic bodies (see Figures 1 to 3) A colored layer 4 was formed on a support 3 made of white synthetic paper by screen printing using a 180 mesh screen plate using a screen printing ink made by uniformly mixing and stirring 5 parts of blue pigment, 50 parts of acrylic ester emulsion (solid content 50% by weight), 0.2 parts of silicone-based defoamer, 3 parts of thickener, 2 parts of wetting agent, 1 part of leveling agent, 10 parts of water, and 2.5 parts of epoxy-based crosslinking agent. Next, on the colored layer, 15 parts of finely divided silica produced by a wet method (product name: Nipsil E-200A, manufactured by Nippon Silica Kogyo Co., Ltd.), 50 parts of an aqueous urethane resin as a binder resin (product name: Hydran AP-10, polyester-based urethane resin, solid content 30% by weight, manufactured by Dainippon Ink and Chemicals, Inc.), 30 parts of water, 0.5 parts of a silicone-based defoamer, 3 parts of an aqueous ink thickener, 1 part of ethylene glycol, and 2 parts of an epoxy-based crosslinking agent were uniformly mixed and stirred to form a porous layer 5, which was then solid-printed over the entire surface using a white screen printing ink, thereby obtaining a water-discoloring material 2 measuring 150 mm x 200 mm. Next, a star-shaped fabric 8 made of cotton fibers was bonded to the inside of a black ABS resin molded body having a thickness of 1.0 mm and dimensions of 140 mm x 190 mm, with the bottom peripheral edge of the base material 7 being in close contact with the surface of the water-discoloring material, and a 5 mm-high gap that keeps the inner peripheral edge out of contact with the surface of the water-discoloring material, to obtain a cover material 6. A water-coloring body 1 including the water-coloring material 2 and the cover material 6 was obtained.

[0018] The water-discoloring material was normally white in color, but when water was applied to the porous layer using a water-filled sprayer, the color changed to blue. The blue-colored water-discoloring material maintained the image for 5 minutes in an environment of 25°C and 65% RH, but gradually disappeared as the water evaporated, and after 10 minutes the entire surface returned to the white water-discoloring material. This change in appearance could be repeated many times. Next, water was applied to the porous layer of the water-discoloring material using a sprayer containing water to cause the material to change color to blue, and then a cover material was placed on the material. After leaving it in an environment of 25°C and 65% RH for 5 minutes, the cover material was removed. The porous layer in the areas where the fabric was not placed maintained its water-absorbent state and appeared blue, while the porous layer in the areas where the fabric was placed dried and appeared white due to the water-absorbency of the fabric, even though it was not in contact with the fabric, so that a white star-shaped image was visible on a blue background. Water was again applied to the porous layer of the water-discoloring material to turn the entire surface blue, and then a cover material was placed on top to form a white star-shaped image. This could be done repeatedly.

[0019] Example 2 Preparation of hydrochromic body set A water-coloring object set was obtained by combining the water-coloring object of Example 1 with a pen having a bullet-shaped fiber pen body (made of nylon resin, diameter 7 mm) at the tip as a water adhesion device and configured so that water could be stored inside the barrel. The water-coloring object set was highly portable and could be played with repeatedly by adding water, as in Example 1.

[0020] Example 3 Preparation of hydrochromic bodies (see Figures 4 to 6) A porous layer 5 was formed on a support 3 made of red synthetic paper by solid printing over the entire surface using a white screen printing ink prepared by uniformly mixing and stirring 15 parts of fine particle silicic acid produced by a wet method (product name: Nipsil E-200A, manufactured by Nippon Silica Kogyo Co., Ltd.), 50 parts of an aqueous urethane resin as a binder resin (product name: Hydran AP-10, polyester-based urethane resin, solid content 30% by weight, manufactured by Dainippon Ink and Chemicals, Inc.), 30 parts of water, 0.5 parts of a silicone-based defoamer, 3 parts of an aqueous ink thickener, 1 part of ethylene glycol, and 2 parts of an epoxy-based crosslinking agent. The mixture was then mixed and stirred to form a porous layer 5 on the support 3 made of red synthetic paper. The porous layer 5 was then solid printed over the entire surface using a white screen printing ink prepared by uniformly mixing and stirring the mixture to form a porous layer 5 on the support 3 made of red synthetic paper, to form a porous layer 5 on the support 3 made of red synthetic paper. The porous layer 5 was then solid printed over the entire surface using a white screen printing ink prepared by uniformly mixing and stirring the mixture to form a porous layer 5 on the support 3 made of red synthetic paper. Next, a circular felt (fabric 8) made of wool fiber was attached to the inner surface of a white PP resin molded body having a thickness of 1.0 mm and dimensions of 150 mm x 200 mm x 5 mm, with both sides and the bottom open, to obtain a cover material 6. A water-coloring body 1 including the water-coloring material 2 and the cover material 6 was obtained.

[0021] The water-discoloring material was normally white, but when water was applied to the porous layer with a water-impregnated brush, it turned red. The red water-discoloring material maintained the image for 5 minutes in an environment of 25°C and 65% RH, but gradually disappeared as the water evaporated, and after 10 minutes the entire surface returned to the white water-discoloring material. This change in appearance could be repeated many times. Next, water was applied to the porous layer of the water-discoloring material with a water-impregnated brush to cause the material to change color to red, and the material was then set in a cover material. After leaving it in an environment of 25°C and 65% RH for 5 minutes, when it was removed from the cover material, the porous layer in the areas where the fabric was not provided maintained its water-absorbent state and exhibited a red color, while the porous layer in the areas where the fabric was provided dried and exhibited a white color due to the water-absorbent nature of the fabric, even though it was not in contact with the fabric, so that a white circular image could be seen on a red background. Water was again applied to the porous layer of the water-discoloring material to turn the entire surface red, and then the material was set on a cover material, whereby a white circular image could be formed, and this could be repeated many times.

[0022] Example 4 Preparation of hydrochromic body set The water-coloring material of Example 3 was combined with a sprayer as a water application tool to obtain a water-coloring material set. The water-coloring object set was highly portable and could be played with repeatedly by adding water, as in Example 3.

[0023] Example 5 Preparation of hydrochromic bodies (see Figures 4 to 6) The surface of a miniature car (support 3) made of a purple plastic molded body was uniformly mixed and stirred with 15 parts of fine particle silicic acid produced by a wet method (trade name: Nipsil E-200A, manufactured by Nippon Silica Kogyo Co., Ltd.), 50 parts of an aqueous urethane resin as a binder resin (trade name: Hydran AP-10, polyester-based urethane resin, solid content 30% by weight, manufactured by Dainippon Ink and Chemicals, Inc.), 30 parts of water, 0.5 parts of a silicone-based defoamer, 3 parts of an aqueous ink thickener, 1 part of ethylene glycol, and 2 parts of an epoxy-based crosslinking agent. The mixture was used to perform solid printing on the entire surface of the surface to form a porous layer 5, and a water-discoloring material 2 measuring 145 mm x 195 mm was obtained. Next, a heart-shaped felt (fabric 8) made of wool fiber was attached to the inner surface of a white PP resin molded body having a thickness of 1.0 mm and dimensions of 100 mm x 50 mm x 30 mm and open sides as the base material 7 to obtain a cover material 6. A water-coloring body 1 including the water-coloring material 2 and the cover material 6 was obtained.

[0024] The water-discoloring material was normally white, but when water was applied to the porous layer with a water-impregnated brush, it turned purple. The purple water-discoloring material maintained the image for 5 minutes in an environment of 25°C and 65% RH, but gradually disappeared as the water evaporated, and after 10 minutes the entire surface returned to the white water-discoloring material. This change in appearance could be repeated many times. Next, water was applied to the porous layer of the water-discoloring material with a water-impregnated brush to cause the material to change color to purple, and the material was then set in a cover material. After leaving it in an environment of 25°C and 65% RH for 5 minutes, when it was removed from the cover material, the porous layer in the areas where the fabric was not provided maintained its water-absorbent state and exhibited a purple color, while the porous layer in the areas where the fabric was provided dried and exhibited a white color due to the water-absorbency of the fabric even though it was not in contact with the fabric, so that a white heart-shaped image was visible on a purple background. Water was again applied to the porous layer of the water-discoloring material to turn the entire surface purple, and then the material was set on a cover material to form a white heart-shaped image, and this could be done repeatedly.

[0025] Example 6 Preparation of hydrochromic body set The water-colored product of Example 5 was combined with a brush as a water application tool to obtain a water-colored product set. The water-coloring object set was highly portable and could be played with repeatedly by applying water, as in Example 5. [Explanation of symbols]

[0026] 1 Water discoloration 2. Water discoloration material 3 Support 4 Colored layer 5 Porous layer 6 Covering material 7 Base material 8 Fabric

Claims

1. This water-discoloring material is characterized in that it comprises a porous layer, which is formed on the upper layer of a coloring layer and in which a low refractive index pigment is fixed in a dispersed state in a binder resin, and a cover material which delays the drying of water absorbed by the porous layer of the water-discoloring material, and the cover material is provided with a cloth made of water-absorbent fibers on a part of the inner surface of the base material.

2. 2. The hydrochromic material according to claim 1, wherein the substrate is opaque.

3. 3. The water-discoloring material according to claim 1, wherein the cover material has a peripheral portion on the lower surface of the substrate that is in close contact with the surface of the water-discoloring material, and an inner peripheral portion that is provided with a gap portion that keeps the inner peripheral portion out of contact with the surface of the water-discoloring material.

4. 3. The water-color changing material according to claim 1, wherein the substrate is a cylindrical body having one or both ends open.

5. 5. The water-discoloring material according to claim 4, wherein the fabric of the cover material is not in contact with the porous layer of the water-discoloring material.

6. 3. The water-discoloring body according to claim 1, comprising a plurality of said water-discoloring materials and a plurality of said cover materials.

7. A water-discoloring object set comprising the water-discoloring object according to claim 1 or 2 and a water-attaching device.

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