JP7520540B2 - Water-discolorable fabric, water-discolorable fabric set using same, and method for manufacturing water-discolorable fabric - Google Patents

Description

The present invention relates to a water-discolorable fabric, a water-discolorable fabric set using the same, and a method for manufacturing the water-discolorable fabric. More specifically, the present invention relates to a water-discolorable fabric that exhibits different appearances when dry (non-liquid-absorbing state) and when impregnated with water (liquid-absorbing state), a water-discolorable fabric set using the same, and a method for manufacturing the water-discolorable fabric.

Conventionally, a water-discoloring fabric has been disclosed which comprises a porous layer on a colored fabric, in which a low refractive index pigment is fixed in a dispersed state together with a binder resin, and in which the porous layer is white in a dry state to conceal the underlying layer, and becomes transparent when it absorbs liquid, allowing the color of the underlying layer to be visually confirmed (see, for example, Patent Document 1).
Although the water-discoloring fabric can enjoy color changes due to the adhesion of water, when forming a porous layer on the fabric, the low refractive index pigment and binder resin may penetrate into the fabric, resulting in insufficient hiding power, or the porous layer may be formed unevenly, resulting in the color of the lower layer being visible in a dry state. Furthermore, the low refractive index pigment and binder resin that penetrate into the fabric may cause adhesion between fibers, resulting in a loss of texture of the fabric.

JP 2000-135386 A

The present invention aims to provide a water-discolorable fabric in which the porous layer sufficiently conceals the underlying layer in a dry state while allowing a clear, visible color change, a water-discolorable fabric set using the same, and a method for producing the water-discolorable fabric.

The present invention provides a water-discolorable fabric comprising a printed fabric and a porous layer on which a low refractive index pigment is fixed in a dispersed state together with a binder resin via a transparent resin layer, the total mass of the transparent resin layer (A) and the porous layer (B) being in the range of 10 to 100 g/ ^m2 , and satisfying the following formula (1); or a water-discolorable fabric comprising a printed fabric and a porous layer on which a low refractive index pigment is fixed in a dispersed state together with a binder resin via a transparent resin layer, the mass C of the printed fabric being 30 g/ ^m2 or more, and satisfying the following formula (2).
0.1≦Mass B/Mass A≦10.0 (1)
0.1≦(mass A of transparent resin layer +mass B of porous layer )/mass C≦1.0 (2)
Further requirements include that the transparent resin layer is formed from a heat-fusible resin or a two-component curing resin, that the printed fabric is a woven fabric, and that the printed fabric is a fabric printed with an image consisting of at least four colors, namely yellow, magenta, cyan, and black.
Further, the present invention requires a water-discolorable fabric set comprising the water-discolorable fabric and a water adhesion tool, and a method for producing a water-discolorable fabric comprising: printing a printed fabric dyed by printing with an inkjet ink on the fabric, printing the printed fabric with a printing ink containing a transparent resin to form a transparent resin layer; and printing an ink containing a low refractive index pigment and a binder resin on the transparent resin layer to provide a porous layer in which the low refractive index pigment is fixed in a dispersed state together with the binder resin.

The present invention provides a water-discolorable fabric in which the porous layer sufficiently conceals the layer underneath when dry, and the porous layer becomes transparent when water is applied, allowing the color of the layer underneath to be clearly seen, and which is highly applicable to a wide variety of fields, including toys, decorations, and design. It also provides a water-discolorable fabric set using the same, and a method for producing the water-discolorable fabric.

1 is a longitudinal sectional view of one embodiment of a water-discolorable fabric of the present invention; FIG.

The fabric may be a woven fabric, a knitted fabric, a braided fabric, a nonwoven fabric, etc., and is preferably a woven fabric. The fabric has a basis weight of 30 g/ ^m2 or more, preferably 40 g/ ^m2 or more, and more preferably 50 g/ ^m2 or more, and is suitable for satisfying printability and durability.
The printing onto the fabric may be performed by screen printing, roller printing, or ink-jet printing, which allows small-lot production of a wide variety of products and instant printing.
A printing ink containing a colorant and a binder resin is printed on a fabric, and then, if necessary, fixed through a drying and curing step to obtain a printed fabric.
The colorant for the textile printing ink may be at least one of a pigment and a dye. By using an inorganic pigment or an organic pigment as the colorant, the light fastness of the printed fabric can be improved.
Examples of the organic pigment include azo pigments, phthalocyanine pigments, quinacridone pigments, perylene pigments, perinone pigments, isoindolinone pigments, isoindoline pigments, dioxazine pigments, thioindigo pigments, anthraquinone pigments, quinophthalone pigments, diketopyrrolopyrrole pigments, threne pigments, indigo pigments, phthalone pigments, methine/azomethine pigments, and metal complex pigments.
Examples of the pigment include color pigments such as yellow, cyan, magenta, and black.
Examples of yellow pigments include C.I. Pigment Yellow 1, 2, 3, 12, 13, 14C, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 119, 110, 114, 128, 129, 138, 150, 151, 154, 155, 180, and 185.
Examples of magenta pigments include C.I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57:1, 112, 122, 123, 168, 184, 202, C.I. Pigment Violet 19, and the like.
Cyan pigments include C.I. Pigment Blue 1, 2, 3, 15:3, 15:4, 16, 22, 60, etc.; C.I. Bat Blue 4, 60, etc.
Examples of black pigments include furnace black, lamp black, acetylene black, channel black, and the like (C.I. Pigment Black 7).
The dyes include acid dyes, direct dyes, reactive dyes, basic dyes, disperse dyes, and the like, and specifically include C.I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. Acid Red 52, 80, 82, 249, 254, 289, C.I. Acid Blue 9, 45, 249, C.I. Acid Black 1, 2, 24, 94, C.I. Food Black 1, 2, C.I. Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173, C.I. Direct Red 1, 4, 9, 80, 81, 225, 227, C.I. Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, C.I. Direct Black 19, 38, 51, 71, 154, 168, 171, 195, C.I. Reactive Red 14, 32, 55, 79, 249, C.I. Reactive Black 3, 4, 35, I. Disperse Yellow 1, 3, 8, 9, 16, 33, 41, 42, 54, 60, 77, 116, 201, 231, C.I. Disperse Red 1, 4, 6, 11, 15, 17, 50, 55, 59, 60, 73, 83, 111, C.I. Disperse Blue 3, 14, 19, 24, 26, 56, 60, 64, 72, 99, 108, 241, 354,
C.I. Disperse Violet 26 and 31.
The colorants may be used in combination of two or more kinds.
Examples of the 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 solvent may be water or a mixture of water and a water-soluble organic solvent. The water-soluble organic solvent may be glycols such as ethylene glycol, diethylene glycol, triethylene glycol, thiodiethylene glycol, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and polyethylene glycol dimethyl ether.
Furthermore, dispersants, surfactants, surface tension adjusters, pH adjusters, conductivity adjusters, preservatives, antifungal agents, ultraviolet absorbers, viscosity adjusters, antioxidants, chelating agents, antifoaming agents, etc. may be added as necessary.
A clear image having rich gradations and consisting of four colors can also be formed by using dye-based inks or pigment-based inks consisting of at least four colors, namely, yellow, magenta, cyan, and black, as the printing inks, and it is preferable to perform printing using an inkjet recording apparatus.
A resin layer is provided on the back surface of the printed fabric by coating, or a water-impermeable sheet material is attached or sewn to the back surface, thereby preventing water from adhering to the back surface of the fabric, thereby achieving satisfactory drying properties and preventing the growth of mold.

The transparent resin layer is provided on the printed fabric.
When a porous layer is formed using an ink for forming a porous layer, which will be described later, the transparent resin layer can prevent the ink from penetrating into the printed fabric, thereby forming a uniform porous layer, and the porous layer can sufficiently conceal the underlying layer in a dry state.
In addition, since the ink forming the porous layer does not penetrate into the printed fabric, the texture and soft feel of the fabric can be maintained.
Examples of the resin that forms the transparent resin layer include amide resins, olefin resins, ethylene-vinyl acetate resins, acrylic resins, epoxy resins, epoxy-acrylate resins, urethane resins, ethylene resins, urethane-acrylic resins, melamine resins, phenol resins, urea resins, urea-melamine resins, diallyl phthalate resins, ester resins, alkyd resins, maleic rosin, vinyl butyral resins, cellulose resins, amide resins, two-component curing resins, ultraviolet curing resins, and electron beam curing resins.
As the transparent resin layer, a heat-meltable resin or a two-component curable resin is preferably used.
Furthermore, it is preferable to use a resin having a glass transition point (Tg) of 20° C. or less, since this makes it possible to maintain the soft feel of the printed fabric.
The transparent resin layer may be formed directly on the printed fabric, or the transparent resin layer may be formed by bonding a transfer sheet having a transparent resin layer formed by applying a transparent resin to a substrate having releasability to the printed fabric, heat fusing the substrate, and then removing the substrate.
It is also possible to adhere the printed fabric via an adhesive resin layer, and then remove the base material to form a transparent resin layer.

The porous layer provided on the transparent resin layer is a layer in which a low refractive index pigment is fixed in a dispersed state together with a binder resin, and is a layer whose transparency differs between a dry state and 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, and the like, 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 the 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.

The amount of 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 the normal state and the transparency in the liquid-absorbed state, the coating amount is preferably 1 to 50 g/ ^m2 , and more preferably 5 to 50 g/ ^m2 . If it is less than 1 g/ ^m2 , it is difficult to obtain sufficient hiding power in the normal state, and if it exceeds 50 g/ ^m2 , it is difficult to obtain sufficient transparency when liquid is absorbed.
The low refractive index pigment is dispersed in a vehicle containing a binder resin as a binding agent, and after coating 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 the binder resin solid content per 1 part by mass of the low refractive index pigment. If the binder resin solid content is less than 0.5 parts by mass per 1 part by mass of the low refractive index pigment, 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 inside of 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 having ionic properties (urethane ionomer) 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 also 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-based 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-based 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-based resin in an amount of 30% or more in terms of solid content 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 resins have different affinities 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 adjustments can be controlled by adding a dispersant or a surfactant as appropriate.

The porous layer can be formed on the transparent resin 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, etc.

In addition, a colorant may be added to the porous layer to color the porous layer in a dry state, or a colored image containing a colorant may be provided on the porous layer to create a configuration that exhibits complex changes in appearance.
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 the 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, a photochromic compound such as a spirooxazine compound, a spiropyran compound, or a diarylethene compound is preferably used.

The mass A of the transparent resin layer of the water-discolorable fabric obtained as described above is in the range of 5 to 90 g/m ² , preferably 5 to 70 g/m ² , and more preferably 5 to 50 g/m ² , so that the hiding power and soft feel of the porous layer can be satisfied.
If the mass A is less than 5 g/ ^m2 , it becomes difficult to form a uniform transparent resin layer on the printed fabric, and therefore it becomes difficult to form a uniform porous layer thereon, and therefore it becomes difficult for the porous layer to sufficiently conceal the underlying layer in a dry state.
If the mass A exceeds 90 g/ ^m2 , the soft feel of the fabric is easily impaired.
When the total mass of the mass A of the transparent resin layer and the mass B of the porous layer is in the range of 10 to 100 g/ ^m2 , preferably 20 to 100 g/ ^m2 , and more preferably 30 to 100 g/ ^m2 , and satisfies the following formula (1), a clear color change can be visually recognized and a soft texture can be satisfied.
0.1≦Mass B/Mass A≦10.0 (1)
If the total mass is less than 10 g, the shielding properties in a dry state decrease, resulting in less color change between the dry state and the liquid-absorbed state.
If the total mass exceeds 100 g/ ^m2 , the texture of the fabric is likely to be impaired, and the transparency of the porous layer in the liquid-absorbed state decreases, making it difficult to visually recognize the original color of the printed fabric.
Regarding formula (1), if the mass B/mass A is less than 0.1, the ratio of the porous layer to the transparent resin layer decreases, and while the texture of the fabric is maintained, the shielding property of the porous layer in a dry state decreases, making it difficult to visually recognize a clear color change.
If the ratio of mass B/mass A exceeds 10, the ratio of the porous layer to the transparent resin layer becomes large, the ability of the transparent resin layer to prevent the ink forming the porous layer from penetrating into the printed fabric decreases, the porous layer becomes non-uniform, and it becomes difficult to uniformly conceal the printed fabric. In addition, since the porous layer is non-uniform in the liquid-absorbed state, it becomes difficult to visually recognize a uniform color change.
Furthermore, when the mass C of the printed fabric is 30 g/ ^m2 or more and satisfies the following formula (2), the hiding power, clear color change, and soft texture of the porous layer can be satisfied.
0.1≦(mass A+mass B)/mass C≦1.0 (2)
If the mass C is less than 30 g/ ^m2 , it becomes difficult to form a uniform transparent resin layer on the printed fabric, and the porous layer also becomes non-uniform, making it difficult for the porous layer to sufficiently hide the underlying layer in a dry state.
If (mass A+mass B)/mass C is less than 0.1, the shielding properties of the porous layer in a dry state decrease, the color change between the dry state and the liquid-absorbed state decreases, and a clear color change becomes difficult to visually recognize.
If (mass A+mass B)/mass C exceeds 1.0, the texture of the fabric is easily impaired.
The water-discolorable fabric is produced by printing and dyeing a fabric using an inkjet recording device with an inkjet ink, optionally rinsing the printed fabric with water and drying by heating, printing a printing ink containing a transparent resin on the printed fabric, optionally drying by heating to form a transparent resin layer, printing an ink containing a low refractive index pigment and a binder resin on the transparent resin layer, optionally drying by heating to provide a porous layer in which the low refractive index pigment is fixed in a dispersed state together with the binder resin.

Specific examples of the water-discoloring fabric include stuffed toys, dolls, doll costumes such as doll dresses, doll accessories such as bags, water gun targets, animal models, drawing toys, toys such as boards that show traces of human and doll handprints and footprints, teaching tools such as water brush sheets, clothing such as dresses and swimsuits, shoes, bags, furniture, artificial flowers, etc.
The present invention can also be applied as various indicators, for example, to detect leakage from piping, pipes, aquariums, tanks, etc., detection of water damage to personal belongings and furniture, detection of water damage to water-prone chemicals in transport or storage locations, detection of condensation, detection of urine in disposable diapers, detection of moisture in soil, etc.

The water-discoloring fabric can be applied with water by directly immersing it in water, by contacting it with wet hands or fingers, or by using a water application tool.
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 directs the water from the container, stamp tools, etc.
A writing implement or applicator using a plastic porous body or a fiber processed body having continuous pores as a pen tip member as the water adhesion implement can easily form a written image and has high practicality.
In addition, the water-adhering tool and water-discolorable fabric can be combined to form a water-discolorable fabric set, which can be used as a teaching tool set or a drawing toy set.

The following examples are given, but the present invention is not limited thereto.
In the examples, "parts" refers to parts by weight.
Example 1 (see FIG. 1)
A colorful floral pattern was process-printed on a white cotton broadcloth (woven fabric with a basis weight of 100 g/ ^cm2 ) using a inkjet printer with non-discoloring inkjet water-based inks in yellow, cyan, magenta, and black containing reactive dyes as colorants.The pattern was then dyed by steam treatment, washed with water, and dried by heating to obtain printed fabric 2 (110 g/ ^cm2 ).
A colorless and transparent water-based screen printing ink consisting of 50 parts of acrylic resin emulsion [product name: Mowinyl 7320, manufactured by Japan Coating Co., Ltd., solid content 40%, glass transition temperature (Tg) -20°C], 5 parts of thickener, 1 part of defoamer, 2 parts of blocked isocyanate-based curing agent, and 42 parts of water was used to perform solid printing on the entire surface of the printed fabric using a 150-mesh screen, and the ink was dried and cured at 130°C for 5 minutes to provide a transparent resin layer 3 (weight A: 20 g/ ^m2 ).
Next, on the transparent resin layer, 15 parts of wet-process silicic acid (trade name: Nipsil E-200, manufactured by Nippon Silica Kogyo Co., Ltd.), 30 parts of urethane emulsion (trade name: Hydran HW-930, manufactured by DIC Corporation, solid content 50%), 40 parts of water, 0.5 parts of silicone-based defoamer, 3 parts of thickener for water-based ink, 1 part of ethylene glycol, and 3 parts of blocked isocyanate-based crosslinking agent were uniformly mixed and stirred to form a white screen printing ink, which was then solid-printed over the entire surface using a 100-mesh screen plate and dried and cured at 130°C for 5 minutes to form a porous layer 4 (weight B: 40 g/ ^m2 ), thereby obtaining a water-discolorable fabric 1.

The total mass (A+B) of the transparent resin layer and the porous layer in the water-discolorable fabric was 60 g/ ^m2 , the mass of the porous layer/the mass of the transparent resin layer was 2.0, and the total mass of the transparent resin layer and the porous layer/the mass of the printed fabric was 0.6.
The water-discolorable fabric has a soft texture and is white in a dry state, and the floral pattern printed on the printed fabric is not visible. However, when water is applied to the porous layer, the water penetrates the porous layer and makes it transparent, and further, the floral pattern printed on the printed fabric is clearly and vividly visible through the transparent resin layer.
The above-mentioned appearance was observed when water was attached, but as it dried, the flower pattern gradually became invisible, and when it was completely dry, it returned to its original white color.
The phase change could be repeated.

The water-discolorable fabric was cut and sewn to obtain doll clothes.
When water was applied to the doll costume, the flower pattern was visible from the white state, and as it dried, the flower pattern gradually became invisible, and when it was completely dry, it returned to the original white color.
The phase change could be repeated.

Example 2
A white polyester taffeta fabric (woven fabric with a basis weight of 70 g/ ^cm2 , coated with 10 g/ ^m2 of transparent acrylic resin on the entire back surface) was process-printed with an inkjet printer using non-discoloring inkjet water-based inks in yellow, cyan, magenta, and black containing disperse dyes as colorants, and the pattern was then dyed by heat treatment to obtain a printed fabric (80 g/ ^cm2 ).
A colorless and transparent water-based screen printing ink consisting of 50 parts of urethane resin emulsion (product name: Hydran AP70, manufactured by DIC Corporation, solid content 35%, glass transition temperature (Tg): -4°C), 5 parts of thickener, 1 part of defoamer, 2 parts of blocked isocyanate curing agent, and 42 parts of water was used to perform solid printing on the entire surface of the printed fabric using a 180-mesh screen, and the ink was dried and cured at 130°C for 5 minutes to provide a transparent resin layer (weight A: 10 g/ ^m2 ).
Next, on the transparent resin layer, 15 parts of wet-process silicic acid (trade name: Nipsil E-200, manufactured by Nippon Silica Kogyo Co., Ltd.), 30 parts of urethane emulsion (trade name: Hydran HW-930, manufactured by DIC Corporation, solid content 50%), 40 parts of water, 0.5 parts of silicone-based defoamer, 3 parts of thickener for water-based ink, 1 part of ethylene glycol, and 3 parts of blocked isocyanate-based crosslinking agent were uniformly mixed and stirred to form a white screen printing ink, which was then solid-printed over the entire surface using a 100-mesh screen plate and dried and cured at 130°C for 5 minutes to form a porous layer 4 (weight B: 40 g/ ^m2 ), thereby obtaining a water-discolorable fabric.

The total mass (A+B) of the transparent resin layer and the porous layer in the water-discolorable fabric was 50 g/ ^m2 , the mass of the porous layer/the mass of the transparent resin layer was 4.0, and the total mass of the transparent resin layer and the porous layer/the mass of the printed fabric was 0.625.
The water-discolorable fabric has a soft texture and is white in a dry state, and the animal pattern printed on the printed fabric cannot be seen, but when water is applied to the porous layer, the water penetrates the porous layer and makes it transparent, and the animal pattern printed on the printed fabric can be clearly and vividly seen through the transparent resin layer.
The above-mentioned appearance was observed when water was attached, but as it dried, the animal patterns gradually became less visible, and when it was completely dry, it returned to its original white color.
The phase change could be repeated.

The water-discolorable fabric was cut, sewn, and attached to an umbrella frame to obtain an umbrella.
When water was applied to the umbrella, the animal pattern became visible from the white state, and as the umbrella dried, the animal pattern gradually became less visible, and when the umbrella was completely dry, it returned to its original white color.
The phase change could be repeated.

Example 3
A pictorial floral pattern was process-printed on a white cotton broadcloth (woven fabric with a basis weight of 200 g/ ^cm2 ) using a inkjet printer with non-discoloring water-based inkjet inks in yellow, cyan, magenta, and black, each containing a reactive dye as a colorant.The pattern was then dyed by steam treatment, washed with water, and dried by heating to obtain a printed fabric (210 g/ ^cm2 ).
A colorless and transparent water-based screen printing ink consisting of 50 parts of acrylic resin emulsion [product name: Mowinyl DM772, manufactured by Japan Coating Co., Ltd., solid content 45%, glass transition temperature (Tg) 6°C], 5 parts of thickener, 1 part of defoamer, 5 parts of finely powdered silica, 3 parts of blocked isocyanate-based curing agent, and 36 parts of water was used to perform solid printing on the entire surface of the printed fabric using a 150 mesh screen, and the ink was dried and cured at 130°C for 5 minutes to provide a transparent resin layer (weight A: 25 g/ ^m2 ).
Next, on the transparent resin layer, 15 parts of wet-process silicic acid (trade name: Nipsil E-200, manufactured by Nippon Silica Industrial Co., Ltd.), 30 parts of urethane emulsion (trade name: Hydran HW-930, manufactured by DIC Corporation, solid content 50%), 40 parts of water, 0.5 parts of silicone-based defoamer, 3 parts of thickener for water-based ink, 1 part of ethylene glycol, and 3 parts of blocked isocyanate-based crosslinking agent were uniformly mixed and stirred to form a white screen printing ink, which was then solid-printed over the entire surface using a 100-mesh screen plate, and dried and cured at 130°C for 5 minutes to form a porous layer, thereby obtaining a water-discolorable fabric (weight B: 45 g/ ^m2 ).

The total mass (A+B) of the transparent resin layer and the porous layer in the water-discolorable fabric was 70 g/ ^m2 , the mass of the porous layer/the mass of the transparent resin layer was 1.8, and the total mass of the transparent resin layer and the porous layer/the mass of the printed fabric was 0.35.
The water-discolorable fabric has a soft texture and is white in a dry state, and the floral pattern printed on the printed fabric cannot be seen, but when water is applied to the porous layer, the water penetrates the porous layer and makes it transparent, and the floral pattern printed on the printed fabric can be clearly and vividly seen through the transparent resin layer.
The above-mentioned appearance was observed when water was attached, but as it dried, the flower pattern gradually became invisible, and when it was completely dry, it returned to its original white color.
The phase change could be repeated.

The water-discolorable fabric was cut and attached to a frame to obtain a canvas-like drawing toy.
A drawing toy set (water-discolorable fabric set) was obtained by combining the drawing toy with a pen having a fiber pen body or the like at the tip as a water-adhering tool and configured so that water can be contained within the barrel.
When the drawing toy set is drawn on the drawing toy with a pen containing water, a floral pattern is visible from a white state, and as it dries, the floral pattern gradually becomes invisible, and when it is completely dry, it returns to the original white color.
The phase change could be repeated.

Example 4
A photographic fruit pattern was process-printed on a white polyester pongee fabric (woven fabric with a basis weight of 100 g/ ^cm2 ) using a inkjet printer with non-discoloring water-based inkjet inks in yellow, cyan, magenta, and black containing disperse dyes as colorants, and the pattern was then dyed by heat treatment to obtain a printed fabric (110 g/ ^cm2 ).
A colorless and transparent water-based screen printing ink consisting of 50 parts of acrylic resin emulsion [product name: Mowinyl 952B, manufactured by Japan Coating Co., Ltd., solid content 46%, glass transition temperature (Tg) -38°C], 5 parts of thickener, 1 part of defoamer, and 44 parts of water was used to perform solid printing on the entire surface of the printed fabric using a 180-mesh screen, and the ink was dried and cured at 150°C for 5 minutes to provide a transparent resin layer (weight A: 15 g/ ^m2 ).
Next, on the transparent resin layer, 15 parts of wet-process silicic acid (trade name: Nipsil E-200, manufactured by Nippon Silica Kogyo Co., Ltd.), 30 parts of urethane emulsion (trade name: Hydran HW-930, manufactured by DIC Corporation, solid content 50%), 40 parts of water, 0.5 parts of silicone-based defoamer, 3 parts of thickener for water-based ink, 1 part of ethylene glycol, and 3 parts of blocked isocyanate-based crosslinking agent were uniformly mixed and stirred to form a white screen printing ink, which was then solid-printed over the entire surface using an 80-mesh screen plate and dried and cured at 130°C for 5 minutes to form a porous layer (weight B: 45 g/ ^m2 ), thereby obtaining a water-discolorable fabric.

The total mass (A+B) of the transparent resin layer and the porous layer in the water-discolorable fabric was 60 g/ ^m2 , the mass of the porous layer/the mass of the transparent resin layer was 3.0, and the total mass of the transparent resin layer and the porous layer/the mass of the printed fabric was 0.75.
The water-discolorable fabric has a soft texture and is white in a dry state, and the fruit pattern printed on the printed fabric cannot be seen, but when water is applied to the porous layer, the water penetrates the porous layer and makes it transparent, and the fruit pattern printed on the printed fabric can be clearly and vividly seen through the transparent resin layer.
The above-mentioned appearance was observed when water was attached, but as it dried, the fruit pattern gradually became invisible, and when it was completely dry, it returned to its original white color.
The phase change could be repeated.

The water-discolorable fabric was cut and sewn to obtain a drawing toy.
A drawing toy set (water-discolorable fabric set) was obtained by combining the drawing toy with a pen having a fiber pen body or the like at the tip as a water-adhering tool and configured so that water can be contained within the barrel.
When the drawing toy set is drawn on the drawing toy with a pen containing water, a fruit pattern is visible from a white state, and as it dries, the fruit pattern gradually becomes invisible, and when it is completely dry, it returns to the original white color.
The phase change could be repeated.

Example 5
On a white rayon twill fabric (woven fabric with a basis weight of 150 g/ ^cm2 ), animation characters were process-printed using an inkjet printer with non-discoloring water-based inks in yellow, cyan, magenta, and black, each containing a reactive dye as a colorant.The ink was then dyed by steam treatment, washed with water, and dried by heating to obtain a printed fabric (160 g/ ^cm2 ).
An aqueous coating ink consisting of 50 parts of vinyl acetate acrylic copolymer resin [product name: Mowinyl 760H, manufactured by Japan Coating Co., Ltd., solid content 50%, glass transition temperature (Tg) -17°C], 1 part of defoaming agent, 1 part of leveling agent, 1 part of viscosity modifier, and 47 parts of water was used to perform solid printing on the entire surface of the printed fabric using a doctor coater, and the ink was dried and cured at 150°C for 5 minutes to provide a transparent resin layer (weight A: 40 g/ ^m2 ).
Next, on the transparent resin layer, 15 parts of wet-process silicic acid (trade name: Nipsil E-200, manufactured by Nippon Silica Kogyo Co., Ltd.), 30 parts of urethane emulsion (trade name: Hydran HW-930, manufactured by DIC Corporation, solid content 50%), 40 parts of water, 0.5 parts of silicone-based defoamer, 3 parts of thickener for water-based ink, 1 part of ethylene glycol, and 3 parts of blocked isocyanate-based crosslinking agent were uniformly mixed and stirred to form a white screen printing ink, which was then solid-printed over the entire surface using an 80-mesh screen plate and dried and cured at 130°C for 5 minutes to form a porous layer (weight B: 40 g/ ^m2 ), thereby obtaining a water-discolorable fabric.

The total mass (A+B) of the transparent resin layer and the porous layer in the water-discolorable fabric was 80 g/ ^m2 , the mass of the porous layer/the mass of the transparent resin layer was 1.0, and the total mass of the transparent resin layer and the porous layer/the mass of the printed fabric was 0.53.
The water-discolorable fabric has a soft texture and is white in a dry state, and the characters printed on the printed fabric cannot be seen, but when water is applied to the porous layer, the water penetrates the porous layer and makes it transparent, and the character pattern printed on the printed fabric can be clearly and vividly seen through the transparent resin layer.
The above-mentioned appearance was observed when water was attached, but as it dried, the character pattern gradually became less visible, and when it was completely dry, it returned to its original white color.
The phase change could be repeated.

The water-discolorable fabric was cut and sewn to obtain a swimsuit.
When water was applied to the swimsuit, the characters were visible from the white state, and as the swimsuit dried, the characters gradually became less visible, and when the swimsuit was completely dry, it returned to its original white color.
The phase change could be repeated.

Comparative Example 1
A colorful floral pattern was process-printed on a white cotton broadcloth (woven fabric with a basis weight of 100 g/ ^cm2 ) by an inkjet printer using non-discoloring inkjet water-based inks of yellow, cyan, magenta, and black containing reactive dyes as colorants, and the pattern was dyed by steam treatment, followed by rinsing with water and drying by heating to obtain a printed fabric.
On the printed fabric, 15 parts of wet-process silicic acid (trade name: Nipsil E-200, manufactured by Nippon Silica Kogyo Co., Ltd.), 30 parts of urethane emulsion (trade name: Hydran HW-930, manufactured by DIC Corporation, solid content 50%), 40 parts of water, 0.5 parts of silicone-based defoamer, 3 parts of thickener for water-based ink, 1 part of ethylene glycol, and 3 parts of blocked isocyanate-based crosslinking agent were uniformly mixed and stirred to form a white screen printing ink, which was then solid-printed over the entire surface using a 100-mesh screen plate, and the ink was dried and cured at 130°C for 5 minutes to form a porous layer (40 g/ ^m2 ), thereby obtaining a water-discolorable fabric.

Although the water-discolorable fabric is white in a dry state, the floral pattern printed on the printed fabric can be seen through the porous layer.
When water was applied from above the porous layer, the water penetrated the porous layer and made it transparent, allowing the floral pattern printed on the printed fabric to be seen. However, the floral pattern was visible even in a dry state, and there was little change between the dry state and the liquid-absorbed state.

Reference Signs List 1 Water-discolorable fabric 2 Printed fabric 3 Transparent resin layer 4 Porous layer

Claims (9)

A water-discolorable fabric comprising a printed fabric and a porous layer provided on the printed fabric, the porous layer having a low refractive index pigment and a binder resin fixed thereto in a dispersed state via a transparent resin layer, the total mass of the transparent resin layer (A) and the porous layer (B) being in the range of 10 to 100 g/ ^m2 , and satisfying the following formula (1):
0.1≦Mass B/Mass A≦10.0 (1) A water-discolorable fabric comprising a printed fabric and a porous layer provided on the printed fabric, the porous layer having a low refractive index pigment and a binder resin fixed in a dispersed state thereto via a transparent resin layer, the printed fabric having a mass C of 30 g/m2 or ^more and satisfying the following formula (2):
0.1≦(mass A of transparent resin layer +mass B of porous layer )/mass C≦1.0 (2) The water-discolorable fabric according to claim 1 or 2, wherein the mass A of the transparent resin layer is in the range of 5 to 90 g/ ^m2 . The water-discolorable fabric according to any one of claims 1 to 3, wherein the transparent resin layer is formed from a heat-melting resin or a two-component curing resin. The water-discolorable fabric according to any one of claims 1 to 4, wherein the printed fabric is a woven fabric. The water-discolorable fabric according to any one of claims 1 to 5, wherein the printed fabric is a fabric printed with an image consisting of at least four colors: yellow, magenta, cyan, and black. A water-discolorable fabric set comprising the water-discolorable fabric according to any one of claims 1 to 6 and a water attachment tool. The water-discoloring fabric set according to claim 7, wherein the water-applying tool is in the form of a writing tool or applicator using a plastic porous body or a fiber processed body having continuous pores as a pen tip member. A method for producing a water-discolorable fabric, comprising the steps of: printing a printed fabric with inkjet ink to dye the fabric; forming a transparent resin layer on the printed fabric by printing with a printing ink containing a transparent resin; and printing an ink containing a low refractive index pigment and a binder resin on the transparent resin layer to form a porous layer in which the low refractive index pigment is fixed in a dispersed state together with the binder resin.

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