JP6938214B2 - Water discoloration indicator - Google Patents

Description

The present invention relates to a water discoloration indicator. More specifically, the present invention relates to a water discoloration indicator that can visually recognize a different aspect from the dry state due to the adhesion of water.

Conventionally, a discolorable laminate in which a porous layer containing a low refractive index pigment is formed on the surface of a support, water is absorbed by the porous layer to make it transparent, and the color of the base is revealed has been disclosed. (See, for example, Patent Document 1).
Further, a discolorable adhesive label in which an adhesive layer is provided on the back surface of a transparent substrate and a porous layer containing a low refractive index pigment and a colored layer are provided on the surface of the transparent substrate is disclosed (for example, a patent). Reference 2).
Although the discolorable laminate and the discolorable adhesive label can be used as an indicator for detecting the adhesion of water, it can only confirm the state in which water is attached, and it returns to the original state by drying, so that water has been used in the past. It was not possible to determine if there was any adhesion.
Further, as another attempt, a water-wetting-sensing printed matter in which an ink containing a water-soluble dye is printed on a paper that does not easily repel water is disclosed (see, for example, Patent Document 3).
In the water-sensitive printed matter, the water-soluble dye elutes from the printed portion and exudes to the non-printed portion due to the adhesion of water, so that it is possible to determine whether or not water has adhered in the past. It did not have a function to determine whether or not the dye was attached.

Japanese Unexamined Patent Publication No. 11-1982271 JP-A-2007-322594 Japanese Unexamined Patent Publication No. 10-2893

The present invention is intended to provide a water discoloration indicator having a function of determining whether or not water has adhered in the past and at present whether or not water has adhered.

In the present invention, a colored layer solubilized with water is attached to one surface of the transparent support, and a low refractive index pigment is fixed to the binder resin in a dispersed state on the other surface, which is opaque in a non-liquid absorbing state and absorbs. A porous layer that becomes transparent in a liquid state is provided, and the refractive index of the low refractive index pigment requires a water discoloration indicator in the range of 1.4 to 1.8.
Further, the colored layer solubilized with water is a layer containing a water-soluble dye, the colored layer solubilized with water is a layer containing a water-soluble dye and a binder resin, and the binder resin is It contains a water-soluble resin and a water-insoluble resin, the transparent support is a water-permeable support, and the transparent support drops 0.1 g of water on one surface for 60 seconds. It is a support that exhibits water permeability that reaches the other surface within the range, a non-discoloring colored layer is provided on the outer surface of the colored layer or the porous layer, and an adhesive layer is provided on the surface in contact with the object. It is a requirement.

INDUSTRIAL APPLICABILITY The present invention can provide a highly convenient water discoloration indicator having a function of determining whether or not water has adhered in the past and at present whether or not water has adhered.

It is a vertical sectional view of one Example of the water discoloration indicator of this invention. It is a vertical sectional view of another Example of the water discoloration indicator of this invention.

In the present invention, a colored layer solubilized with water is attached to one surface of the transparent support, and a low refractive index pigment is fixed to the binder resin in a dispersed state on the other surface. It is a water discoloration indicator provided with a porous layer that becomes transparent in a liquid state.

The transparent support is not particularly limited, and for example, cloth such as paper, synthetic paper, woven fabric, knitted fabric, braid, non-woven fabric, plastic, glass, ceramics and the like are used. Further, the shape may be a planar shape or a three-dimensional shape.
The transparent support may have colored transparency in which the support itself is colored.
Examples of the coloring agent for coloring the support include general dyes, fluorescent dyes, and coloring pigments. Among them, the coloring pigments include general pigments, fluorescent pigments, metal powders, and core materials such as mica, alumina, and glass. Can be exemplified by a transparent metal glossy pigment (pearl pigment) coated with titanium oxide.
When a non-permeable support is used as the transparent support, the change in the appearance of the colored layer provided on one surface and the change in the appearance of the porous layer provided on the other surface are visually recognized through the transparent support. NS.
By using a water-permeable support as the transparent support, water adhering from the colored layer side adheres to the porous layer through the support, and water adhering from the porous layer side passes through the support. Since it adheres to the colored layer, it is possible to express a change in the appearance of both layers.
The water-permeable support preferably expresses the appearance change of both layers by using a support in which 0.1 g of water is dropped on one surface and the water reaches the other surface within 60 seconds. Can be made to.
As a method for evaluating water permeability, 1.0 part of red dye [trade name: phloxine, manufactured by Eisen Co., Ltd.], polyvinyl alcohol resin [trade name: Gosenol KL03, manufactured by Nippon Synthetic Chemical Co., Ltd.] 30.0. An ink consisting of 69.0 parts of water was applied onto a polyethylene terephthalate film, dried and cured at 130 ° C. for 5 minutes, and the support was closely placed on the film provided with a red coating film. When 0.1 g of water is dropped on one surface (front surface) and the state of the other surface (back surface) is visually observed, if the red coating film adheres to the support within 60 seconds, it is said to have water permeability. Shall be.

Examples of the water-soluble colored layer provided on one surface of the transparent support include a colored layer composed of a water-soluble dye and, if necessary, a binder resin, or a colored layer containing a pigment and a water-soluble resin. ..
In the colored layer, the water-soluble dye contained in the colored layer elutes to the surroundings due to the adhesion of water, and the pigment diffuses to the surroundings, so that it is possible to determine whether or not water has adhered in the past.
As the water-soluble dye, an acid dye, a basic dye, a direct dye or the like can be used.
Acid dyes include ponceau (CI 16255), tartrazine (CI 19140), acid blue black 10B (CI 20470), guinea green (CI 42085), brilliant blue FCF. (CI 42090), Acid Violet 6B (CI 42640), Solve Blue (CI 42755), Naphthalene Green (CI 44025), Eosin (CI 45380), Phloxine (CI 45410), erythrosine (CI 45430), niglosin (CI 50420), acid phloxine (CI 56205) and the like are used.
As basic dyes, chrysoidin (CI 11270), methyl violet FN (CI 42535), crystal violet (CI 42555), malachite green (CI 42000), Victoria blue FB ( CI 44045), Rhodamine B (CI 45170), Acridine Orange NS (CI 46005), Methylene Blue B (CI 52015) and the like are used.
As direct dyes, Congo Red (CI 22120), Direct Sky Blue 5B (CI 24400), Violet BB (CI 27905), Direct Deep Black EX (CI 30235), Kaya Las Black G Conch (CI 35225), Direct Fast Black G (CI 35255), Phthalocyanine Blue (CI 74180) and the like are used.
Examples of the pigment include inorganic pigments such as carbon black and ultramarine, organic pigments such as copper phthalocyanine blue and benzidine yellow, synthetic resin fine particle fluorescent pigments obtained by solidifying various fluorescent dyes in a resin matrix, and metallic gloss pigments. It can be exemplified.

As the binder resin, either a water-soluble resin or a water-insoluble resin can be used, but a water-soluble resin is preferably used, and a water-soluble resin and a water-insoluble resin are more preferably used in combination.
By using the water-soluble resin, the elution property and diffusivity at the time of water adhesion are excellent, and by using the water-soluble resin and the water-insoluble resin in combination, the elution property and diffusivity at the time of water adhesion are excellent and high. It also has excellent storage stability in the initial state of the colored layer under humidity.
When the water-soluble resin and the water-insoluble resin are used in combination, it is preferable to use the water-soluble resin and the water-insoluble resin in the colored layer in a mass ratio of 95: 5 to 5:95, more preferably 90. : 10 to 10:90.
The water-soluble resin is not particularly limited as long as it is soluble in water, but is a water-soluble synthesis of polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, polyethylene glycol, water-soluble acrylic resin, water-soluble nylon resin and the like. Resin, sodium alginate, propylene glycol alginate, gum arabic, casein, sodium caseinate, guar gum, gelatin, dextrin, starch, processed starch, water-soluble resin derived from natural products such as reduced candy, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose , Methyl cellulose, ethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl ethyl cellulose, and other cell rolls and cellulose derivatives and salts thereof, and polysaccharides such as dextran, starch sugar, pullulan, and cycloamylose.
Examples of the water-insoluble resin include urethane-based resin, nylon resin, vinyl acetate resin, acrylic acid ester resin, acrylic acid ester copolymer resin, acrylic polyol resin, vinyl chloride-vinyl acetate copolymer resin, maleic acid resin, and polyester resin. , Styrene resin, styrene copolymer resin, polyethylene resin, polycarbonate resin, epoxy resin, styrene-butadiene copolymer resin, acrylonitrile-butadiene copolymer resin, methyl methacrylate-butadiene copolymer resin, butadiene resin, chloroprene resin, melamine resin, And emulsions of the above-mentioned resins and the like.

The colored layer is formed by mixing a colorant such as a water-soluble dye or a pigment in a vehicle to prepare a liquid composition such as a paint or a printing ink, and by the same means as the porous layer described later.
As the solvent for the paint or printing ink, water, water and a water-soluble organic solvent, or a solvent can be used.
The solvents used are aromatic hydrocarbons of benzene, toluene and xylene, hexane, cyclohexane, saturated hydrocarbons of octane, acetone, methyl ethyl ketone, ketones of cyclohexanone, chloroform, halogenated hydrocarbons of trichloroethane, mineral spirit and petroleum ether. Petroleum-based solvent can be mentioned.
The paint or printing ink may contain a thickener, a dispersant, a pH adjuster, a preservative, a fungicide, an antioxidant, or the like, if necessary.

Examples of the colored layer include various characters, symbols, figures, patterns, and shapes such as people, animals, plants, fruits, foodstuffs, vehicles, buildings, and celestial bodies. The pattern may be a colored image of an independent discontinuous pattern such as a polka dot pattern, or a colored image of a partially connected continuous pattern such as a checkered pattern.

The colored layer is provided on one surface of the transparent support, and it is possible to determine whether or not the colorant is eluted or diffused by the adhesion of water to the adhesion of water.
In addition, when a water-permeable support is used, it is necessary to determine whether or not the colorant elutes or diffuses into the support or the support and the porous layer due to the adhesion of water and the water adheres. Can be done.
As the colored layer, the colored layer containing the water-soluble dye is preferably used because the water-soluble dye is easily eluted into the support or the support and the porous layer due to the adhesion of water, and is highly variable.

The porous layer provided on the other surface of the transparent support is a layer in which a low refractive index pigment is fixed together with a binder resin in a dispersed state, and the transparency is different between a dry state and a liquid absorbing state.
The refractive index of the low refractive index pigment is in the range of 1.4 to 1.8, and exhibits good transparency when it absorbs water.
Examples of the low refractive index pigment include silicic acid and salts thereof, barite powder, barium sulfate, barium carbonate, calcium carbonate, gypsum, clay, talc, alumina, alumina white, magnesium carbonate and the like, and silicic acid and salts thereof are preferable. Used.
Examples of the salt of silicate include aluminum silicate, potassium aluminum silicate, sodium aluminum silicate, aluminum calcium silicate, potassium silicate, calcium silicate, sodium calcium silicate, sodium silicate, magnesium silicate, potassium magnesium silicate and the like.
Further, two or more kinds 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 those having a particle size of 0.03 to 10.0 μm are preferably used.
Silicic acid is mentioned as a preferably used low refractive index pigment.
The silicic acid may be a silicic acid produced by a dry method, but a silicic acid produced by a wet method (hereinafter referred to as a wet method silicic acid) is particularly effective. Explaining this point, the silicic acid is amorphous. It is produced as a quality amorphous silicic acid, and depending on the production method, a dry method using a vapor phase reaction such as thermal decomposition of silicon halide such as silicon tetrachloride (hereinafter referred to as dry silicic acid) and sodium silicate are used. The dry method silicic acid and the wet method silicic acid have different structures, and the dry method silicic acid has a three-dimensional structure in which silicic acid is tightly bonded. On the other hand, the wet method silicic acid has a so-called two-dimensional structural portion in which silicic acid is condensed to form a long molecular arrangement.
Therefore, since the molecular structure is coarser than that of the dry silicic acid, when the wet silicic acid is applied to the porous layer, the diffuse reflection of light in the dry state is excellent as compared with the system using the dry silicic acid. Therefore, it is presumed that the concealment property under normal conditions will increase.
Further, since the porous layer absorbs water, the wet method silicic acid has more hydroxyl groups existing as silanol groups on the particle surface than the dry method silicic acid, and the degree of hydrophilicity is large. It is preferably used.
In addition, in order to adjust the hiding property of the porous layer in a normal state and the transparency in a liquid absorbing state, another general-purpose low refractive index pigment can be used in combination with the wet method silicic acid.

The low refractive index pigment in the porous layer depends on properties such as particle size, specific surface area, and oil absorption, but in order to satisfy both the hiding property in the normal state and the transparency in the liquid absorbing state, it is necessary to satisfy both. preferably the coating amount is 1 to 30 g / ^{m 2,} more preferably 5 to 20 g / ^{m 2.} If it is less than 1 g / m ² , it is difficult to obtain sufficient concealment under normal conditions, and if it ^{exceeds 30 g / m 2} , it is difficult to obtain sufficient transparency at the time of liquid absorption.
The low refractive index pigment is dispersed in a vehicle containing a binder resin as a binder, applied to a support, and then dried to form a porous layer.
Examples of the binder resin include urethane resin, nylon resin, vinyl acetate resin, acrylic acid ester resin, acrylic acid ester copolymer resin, acrylic polyol resin, vinyl chloride-vinyl acetate copolymer resin, maleic acid resin, polyester resin, and styrene. Resin, styrene copolymer resin, polyethylene resin, polycarbonate resin, epoxy resin, styrene-butadiene copolymer resin, acrylonitrile-butadiene copolymer resin, methyl methacrylate-butadiene copolymer resin, butadiene resin, chloroprene resin, melamine resin, and the above. Examples thereof include each resin emulsion, casein, starch, cellulose derivative, polyvinyl alcohol, urea resin, phenol resin and the like.
The mixing ratio of the low refractive index pigment and these binder resins depends on the type and properties of the low refractive index pigment, but preferably, the binder resin solid content is 0.5 to 1 part by mass of the low refractive index pigment. It is 2 parts by mass, more preferably 0.8 to 1.5 parts by mass. When the solid content of the binder resin is less than 0.5 parts by mass with respect to 1 part by mass of the low refractive index pigment, it is difficult to obtain a practical film strength of the porous layer, and when it exceeds 2 parts by mass. In addition, the permeability of water into the porous layer is deteriorated.
Since the mixing ratio of the binder resin to the colorant is small in the porous layer as compared with a general coating film, it is difficult to obtain sufficient film strength. Therefore, it is effective to use a nylon resin or a urethane-based resin among the above-mentioned binder resins in order to increase the scratch resistance.
Examples of the urethane-based resin include polyester-based urethane resin, polycarbonate-based urethane resin, and polyether-based urethane resin, and two or more of them can be used in combination. Further, a colloid in which the resin is emulsified and dispersed in water or self-emulsified by the ionic group of the ionic urethane resin (urethane ionomer) itself without the need for an emulsifier and dissolved or dispersed in water. A dispersed type (ionomer type) urethane resin can also be used.
Either an aqueous urethane resin or an oil urethane resin can be used as the urethane resin, but in the present invention, an aqueous urethane resin, particularly a urethane emulsion resin or a colloidal dispersion type urethane resin is preferable. Used for.
The urethane-based resin can be used alone, but other binder resins can also be used in combination depending on the type of support and the performance required for the film. When a binder resin other than the urethane resin is used in combination, it is preferable that the urethane resin is contained in the binder resin of the porous layer in a solid content mass ratio of 30% or more in order to obtain a practical film strength.
Among the binder resins, those having a crosslinkable property can be further improved in film strength by adding an arbitrary cross-linking agent and cross-linking.
The binder resin has different affinities with water, and by combining these, the permeation time into the porous layer, the degree of permeation, and the slow speed of drying after permeation can be adjusted. Further, the adjustment can be controlled by appropriately adding a dispersant or a surfactant.

The porous layer can be coated by screen printing, offset printing, gravure printing, coater, tampo printing, transfer or other printing means, brush coating, spray coating, electrostatic coating, electrodeposition coating, sink coating, roller coating, dip coating, etc. It can be formed on a support.
The porous layer may be an image of a circle, an ellipse, a square, a rectangle, or the like, but in addition to various characters, symbols, figures, and patterns, people, animals, plants, fruits, foodstuffs, vehicles, and buildings. , An image of a celestial body or the like.

The water discoloration indicator can be easily adhered to an object by providing an adhesive layer at the bottom layer.
The pressure-sensitive adhesive layer is formed of a general-purpose acrylic resin, urethane-based resin, styrene-butadiene copolymer, vinyl ether copolymer, a pressure-sensitive adhesive mainly composed of natural rubber, and the like.
Further, the adhesive layer may be provided with a release layer such as a release paper for convenience at the time of use.

The water discoloration indicator can be attached to an article, cut into a desired size and shape and attached to the article, or a water discoloration indicator can be wound on the surface of a core formed of paper or the like. It can also be put into practical use as a tape form.
By adopting the tape form, it is easy to carry and it is not necessary to provide a release layer, so that resource saving can be promoted, and it can be cut into an appropriate size according to the length of the object and attached. Satisfies applicability to articles of various shapes and sizes.

Examples of the object to which the water discoloration indicator is attached include water leakage detection of pipes, pipes, water tanks, etc., and disposable diapers, which can detect urine.

Examples of the present invention will be described below. In addition, the part in an Example shows a mass part.
Example 1 (see FIG. 1)
Phloxine (CI 45410) as a red water-soluble dye on one surface of ^{a polyester tuffa fabric (grain size: 60 g / m 2} ) having white water permeability and transparency (translucency) as the transparency support 2. ) 1.0 part, polyvinylpyrrolidone resin (trade name: Socalan K-17, manufactured by BASF) 45.0 parts, acrylic acid ester resin emulsion 11.1 parts [trade name: Movinyl 966A, manufactured by Nippon Synthetic Chemical Co., Ltd., A dot pattern having a diameter of 2 mm is printed on a 180-mesh screen plate using a screen printing ink containing 45.0 parts of water and a solid content of 45%, and dried and cured at 130 ° C. for 5 minutes to form a colored layer 4. Formed.
It took 3 seconds for the water to reach the back surface by dropping 0.1 g of water from the front surface on the transparent support at room temperature (25 ° C.).
Next, on the other surface of the transparent support, 15 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], vinyl chloride / vinyl acetate modified resin [trade name: solvent AL, manufactured by Nissin Chemical Industry Co., Ltd.] 10 parts, petroleum-based aromatic hydrocarbon solvent [trade name: Solbesso 100, manufactured by ExxonMobil Co., Ltd.] 15 parts, cyclohexanone 25 parts, surfactant 0.5 parts Using the mixed ink for screen printing, the entire surface was solid-printed on a 100-mesh screen plate and dried and cured at 60 ° C. for 30 minutes to form the porous layer 3.
Next, 1.0 part of blue pigment, 10 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], urethane emulsion [trade name: Hydran AP-10, on the porous layer. Dainippon Ink Chemical Industry Co., Ltd., solid content 30%] 45 parts, water 40 parts, silicone-based defoamer 0.5 parts, water-based ink thickener 3 parts, ethylene glycol 1 part, isocyanate-based cross-linking agent A blue non-discoloring colored layer 5 having water permeability, which is solid-printed on the entire surface with a 180-mesh screen plate using a blue screen printing ink obtained by mixing three parts, and dried and cured at 130 ° C. for 5 minutes. Was further formed, and a water-insoluble adhesive layer 6 made of a dot-shaped acrylic resin was provided on the non-color-changing colored layer to obtain a water-coloring indicator 1.

When the adhesive layer of the water discoloration indicator was attached to the connecting portion of the pipe and put into practical use, it was porous under the normal state (non-water absorption state) via the red dot pattern by the colored layer and the white transparent support. White color due to the layer is visible, but when water leaks from the connecting part of the pipe and adheres to the back surface of the water discoloration indicator, the porous layer becomes transparent by absorbing liquid and the blue color due to the non-discoloration colored layer is visually recognized. , The water-soluble dye contained in the colored layer is eluted to the surroundings, the dot pattern is in a blurred state, and the dot pattern is transferred to the transparent support and is in a soaked state.
The state in which water has adhered shows the above-mentioned aspect, but when the porous layer dries, it returns to the original white state, and only the bleeding red dot pattern due to the colored layer is visually recognized, and it is determined that water has adhered in the past. I was able to.
In addition, the water discoloration indicator was able to visually recognize the same appearance change even if water adhered from the surface (colored layer side).

Example 2 (see FIG. 2)
Wet method fine particle silica [trade name: Nip Seal E-220] on one surface of ^{a polyester tuffa fabric (grain size: 80 g / m 2} ) having white water permeability and transparency (translucency) as the transparency support 2. , Nippon Silica Industry Co., Ltd.] 15 parts, Urethane emulsion [Product name: Hydran AP-10, Dainippon Ink Chemical Industry Co., Ltd., Solid content 30%] 45 parts, Water 40 parts, Silicone defoamer Using a screen printing ink made by mixing 0.5 parts, 3 parts of a thickener for water-based ink, 1 part of ethylene glycol, and 3 parts of an isocyanate-based cross-linking agent, the entire surface is solid-printed on a 100-mesh screen plate. The porous layer 3 was formed by drying and curing at 100 ° C. for 5 minutes.
It took 15 seconds for the water to reach the back surface by dropping 0.1 g of water from the front surface on the transparent support at room temperature (25 ° C.).
Next, 1.0 part of phloxine (CI 45410), 35.0 parts of polyvinylpyrrolidone resin (trade name: Socalan K-17, manufactured by BASF), as a red water-soluble dye, were placed on the other surface of the transparent support. 180 mesh screen plate using screen printing ink containing 32.6 parts of acrylic acid ester resin emulsion [trade name: Movinyl 966A, manufactured by Nippon Synthetic Chemical Co., Ltd., solid content 45%] and 35.0 parts of water. A dot pattern having a diameter of 2 mm was printed at 100 ° C. and dried and cured at 100 ° C. for 5 minutes to form a colored layer 4.
Further, 1.0 part of blue pigment, 5 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], vinyl chloride / vinyl acetate modified resin [trade name: Solvine AL, manufactured by Nissin Chemical Industry Co., Ltd.] 10 parts, petroleum-based aromatic hydrocarbon solvent [trade name: Solbesso 100, manufactured by Exxon Mobile Co., Ltd.] 15 parts, cyclohexanone 25 parts, surfactant 0.5 parts The entire surface is solid-printed on a 100-mesh screen plate using a screen printing ink obtained by mixing the above, and dried and cured at 60 ° C. for 30 minutes to form a blue non-discoloring colored layer 5 having water permeability. Further, a water-insoluble adhesive layer 6 made of a dot-shaped acrylic resin was provided on the non-color-changing colored layer to obtain a water-coloring indicator 1.

When the adhesive layer of the water discoloration indicator was attached to the connecting portion of the pipe and put into practical use, the white color due to the porous layer was visually recognized in the normal state (non-water absorption state), but water leaked from the connecting portion of the pipe. When it adheres to the back surface of the water discoloration indicator, the water-soluble dye contained in the colored layer elutes to the surroundings and the dot pattern becomes blurred, and it migrates to the transparent support and the porous layer and soaks into it. At the same time, the porous layer becomes transparent due to the liquid absorption, and the bleeding red dot pattern and the blue color due to the non-discoloring colored layer are visually recognized.
The state where water adheres shows the above-mentioned aspect, but when the porous layer dries, it returns to the original white state, but a pale red dot pattern due to the colored layer soaked into the porous layer is visually recognized, and water has been seen in the past. It was possible to determine that it had adhered.
Further, even if water adhered from the surface (porous layer side) of the indicator, the same aspect change could be visually recognized.

Example 3
Nylon Taffeta Fabric (basis weight: 70 g / m ²⁾ having a white water permeability and transparency as transparent support (translucent) on one side of the wet process particulate silica [trade name: Nipsil E-220, Nippon Silica Industry Co., Ltd.] 15 parts, urethane emulsion [trade name: Hydran AP-10, Dainippon Ink and Chemicals Co., Ltd., solid content 30%] 45 parts, water 40 parts, silicone defoamer 0 Using a screen printing ink that is a mixture of 5 parts, 3 parts of thickener for water-based ink, 1 part of ethylene glycol, and 3 parts of isocyanate-based cross-linking agent, solid printing is performed on the entire surface with a 100-mesh screen plate, and 100 parts are printed. It was dried and cured at ° C. for 5 minutes to form a porous layer.
It took 5 seconds for the water to reach the back surface by dropping 0.1 g of water from the front surface on the transparent support at room temperature (25 ° C.).
Next, 1.0 part of phloxine (CI 45410), 35.0 parts of polyvinylpyrrolidone resin (trade name: Socalan K-17, manufactured by BASF), as a red water-soluble dye, were placed on the other surface of the transparent support. 180 mesh screen plate using screen printing ink containing 32.6 parts of acrylic acid ester resin emulsion [trade name: Movinyl 966A, manufactured by Nippon Synthetic Chemical Co., Ltd., solid content 45%] and 35.0 parts of water. A dot pattern having a diameter of 2 mm was printed at 100 ° C. and dried and cured at 100 ° C. for 5 minutes to form a colored layer.
Further, 1.0 part of blue pigment, 5 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], vinyl chloride / vinyl acetate modified resin [trade name: Solvine AL, manufactured by Nissin Chemical Industry Co., Ltd.] 10 parts, petroleum-based aromatic hydrocarbon solvent [trade name: Solbesso 100, manufactured by Exxon Mobile Co., Ltd.] 15 parts, cyclohexanone 25 parts, surfactant 0.5 parts The entire surface is solid-printed on a 100-mesh screen plate using a screen printing ink obtained by mixing the above, and dried and cured at 60 ° C. for 30 minutes to form a water-permeable blue non-discoloring colored layer. Further, a water-insoluble adhesive layer made of a dot-shaped acrylic resin was provided on the non-color-changing colored layer to obtain a water-color change indicator.

When the adhesive layer of the water discoloration indicator was attached to the connecting portion of the pipe and put into practical use, the white color due to the porous layer was visually recognized in the normal state (non-water absorption state), but water leaked from the connecting portion of the pipe. When it adheres to the back surface of the water discoloration indicator, the water-soluble dye contained in the colored layer elutes to the surroundings and the dot pattern becomes blurred, and it migrates to the transparent support and the porous layer and soaks into it. At the same time, the porous layer becomes transparent due to the liquid absorption, and the bleeding red dot pattern and the blue color due to the non-discoloring colored layer are visually recognized.
The state where water adheres shows the above-mentioned aspect, but when the porous layer dries, it returns to the original white state, but a pale red dot pattern due to the colored layer soaked into the porous layer is visually recognized, and water has been seen in the past. It was possible to determine that it had adhered.
Further, even if water adhered from the surface (porous layer side) of the indicator, the same aspect change could be visually recognized.

Example 4
Brilliant Blue FCF-L as a blue water-soluble dye on one surface of a calendar-processed polyester tuffa fabric (grain size: 85 g / m ^{2) that has white water permeability and transparency (translucency) as a transparency support.} Use a screen printing ink containing 1.0 part (CI.42090), 30.0 parts of polyvinyl alcohol resin (trade name: Gosenol KL03, manufactured), and 70.0 parts of water to make a 180-mesh screen plate. The lattice pattern was printed and dried and cured at 130 ° C. for 5 minutes to form a colored layer.
It took 55 seconds for the water to reach the back surface by dropping 0.1 g of water from the front surface on the transparent support at room temperature (25 ° C.).
Next, on the other surface of the transparent support, 15 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], vinyl chloride / vinyl acetate modified resin [trade name: solvent AL, manufactured by Nissin Chemical Industry Co., Ltd.] 10 parts, petroleum-based aromatic hydrocarbon solvent [trade name: Solbesso 100, manufactured by ExxonMobil Co., Ltd.] 15 parts, cyclohexanone 25 parts, surfactant 0.5 parts Using the mixed ink for screen printing, the entire surface was solid-printed on a 100-mesh screen plate and dried and cured at 60 ° C. for 30 minutes to form a porous layer.
Next, 1.0 part of pink pigment, 10 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], urethane emulsion [trade name: Hydran AP-10] on the porous layer. , Dainippon Ink Chemical Industry Co., Ltd., solid content 30%] 45 parts, water 40 parts, silicone-based defoaming agent 0.5 parts, water-based ink thickener 3 parts, ethylene glycol 1 part, isocyanate-based cross-linking Using a pink screen printing ink made by mixing 3 parts of the agent, solid printing is performed on the entire surface with a 180 mesh screen plate, and the product is dried and cured at 130 ° C. for 5 minutes to have water permeability and non-discoloration of pink. A colored layer was formed, and a water-insoluble adhesive layer made of a dot-shaped acrylic resin was further provided on the non-color-changing colored layer to obtain a water-color change indicator.

When the adhesive layer of the water discoloration indicator was attached to the connecting portion of the pipe and put into practical use, in a normal state (non-water absorption state), it was formed of a porous layer via a blue lattice pattern by a colored layer and a transparent support. White is visible, but when water leaks from the connecting part of the pipe and adheres to the back surface of the water discoloration indicator, the porous layer becomes transparent by absorbing liquid and the pink color due to the non-discoloration coloring layer is visually recognized. The water-soluble dye contained in the colored layer elutes to the surroundings, the lattice pattern becomes blurred, and the transparent support is transferred to the soaked state.
The state in which water adheres shows the above-mentioned aspect, but when the porous layer dries, it returns to the original white state, and only the blurred blue lattice pattern due to the colored layer is visually recognized, and it is determined that water has adhered in the past. I was able to.
In addition, the water discoloration indicator was able to visually recognize the same appearance change even if water adhered from the surface (colored layer side).

Example 5
^{One of the single-sided heat-seal papers (grain size: 50 g / m 2} , trade name: Heat Pack MW, manufactured by Nippon Paper Pavilia Co., Ltd.) that has white water permeability and transparency (translucency) as a transparency support. On the surface (heat seal surface), 1.0 part of floxin (CI 45410) as a red water-soluble dye, 45.0 parts of polyvinylpyrrolidone resin (trade name: Socalan K-17, manufactured by BASF), acrylic acid ester resin. Using a screen printing ink containing 11.1 parts of emulsion [trade name: Movinyl 966A, manufactured by Nippon Synthetic Chemical Co., Ltd., solid content 45%] and 45.0 parts of water, a 180 mesh screen plate with a diameter of 2 mm The dot pattern was printed and dried and cured at 130 ° C. for 5 minutes to form a colored layer.
It took 20 seconds for the water to reach the back surface by dropping 0.1 g of water from the front surface on the transparent support at room temperature (25 ° C.).
Next, on the other surface of the transparent support, 15 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], vinyl chloride / vinyl acetate modified resin [trade name: solvent AL, manufactured by Nissin Chemical Industry Co., Ltd.] 10 parts, petroleum-based aromatic hydrocarbon solvent [trade name: Solbesso 100, manufactured by ExxonMobil Co., Ltd.] 15 parts, cyclohexanone 25 parts, surfactant 0.5 parts Using the mixed ink for screen printing, the entire surface was solid-printed on a 100-mesh screen plate and dried and cured at 60 ° C. for 30 minutes to form a porous layer.
Next, 1.0 part of blue pigment, 10 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], urethane emulsion [trade name: Hydran AP-10, on the porous layer. Dainippon Ink Chemical Industry Co., Ltd., solid content 30%] 45 parts, water 40 parts, silicone-based defoamer 0.5 parts, water-based ink thickener 3 parts, ethylene glycol 1 part, isocyanate-based cross-linking agent Using a blue screen printing ink made by mixing three parts, the entire surface is solid-printed on a 180-mesh screen plate, and dried and cured at 80 ° C. for 10 minutes to form a water-permeable blue non-discoloring colored layer. Further, a water-insoluble adhesive layer made of a dot-shaped acrylic resin was provided on the non-discoloring colored layer to obtain a water discoloration indicator.

When the adhesive layer of the water discoloration indicator was attached to the connecting portion of the pipe and put into practical use, in the normal state (non-water absorption state), the red dot pattern by the colored layer and the porous layer via the transparent support White is visible, but when water leaks from the connecting part of the pipe and adheres to the back surface of the water discoloration indicator, the porous layer becomes transparent due to liquid absorption, and the blue color due to the non-discoloration coloring layer is visually recognized and colored. The water-soluble dye contained in the layer elutes to the surroundings, and the dot pattern becomes a bleeding state, and the dot pattern shifts to the transparent support and becomes a soaked state.
The state where water is attached shows the above-mentioned aspect, but when the porous layer dries, it returns to the original white state, and only the bleeding red dot pattern due to the colored layer is visible, indicating that water has adhered in the past. I was able to distinguish.
In addition, the water discoloration indicator was able to visually recognize the same appearance change even if water adhered from the surface (colored layer side).

Example 6
Wet method fine particles on one surface of ^{low-density synthetic fiber compounded paper (grain size: 50 g / m 2,} manufactured by Nippon Paper Pavilia Co., Ltd.) that has white water permeability and transparency (translucency) as a transparent support. Silica [Product name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.] 15 parts, Urethane emulsion [Product name: Hydran AP-10, manufactured by Dainippon Ink Chemical Industry Co., Ltd., solid content 30%] 45 parts, Using a screen printing ink made by mixing 40 parts of water, 0.5 part of silicone defoamer, 3 parts of thickener for water-based ink, 1 part of ethylene glycol, and 3 parts of isocyanate-based cross-linking agent, 100 mesh. The entire surface was solidly printed on a screen plate and dried and cured at 100 ° C. for 5 minutes to form a porous layer.
It took 10 seconds for the water to reach the back surface by dropping 0.1 g of water from the front surface on the transparent support at room temperature (25 ° C.).
Next, 1.0 part of phloxine (CI 45410), 35.0 parts of polyvinylpyrrolidone resin (trade name: Socalan K-17, manufactured by BASF), as a red water-soluble dye, were placed on the other surface of the transparent support. 180 mesh screen plate using screen printing ink containing 32.6 parts of acrylic acid ester resin emulsion [trade name: Movinyl 966A, manufactured by Nippon Synthetic Chemical Co., Ltd., solid content 45%] and 35.0 parts of water. A dot pattern having a diameter of 2 mm was printed at 100 ° C. and dried and cured at 100 ° C. for 5 minutes to form a colored layer.
Further, 1.0 part of blue pigment, 5 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], vinyl chloride / vinyl acetate modified resin [trade name: Solvine AL, manufactured by Nissin Chemical Industry Co., Ltd.] 10 parts, petroleum-based aromatic hydrocarbon solvent [trade name: Solbesso 100, manufactured by Exxon Mobile Co., Ltd.] 15 parts, cyclohexanone 25 parts, surfactant 0.5 parts The entire surface is solid-printed on a 100-mesh screen plate using a screen printing ink obtained by mixing the above, and dried and cured at 60 ° C. for 30 minutes to form a water-permeable blue non-discoloring colored layer. Further, a water-insoluble adhesive layer made of a dot-shaped acrylic resin was provided on the non-color-changing colored layer to obtain a water-coloring indicator.

When the adhesive layer of the water discoloration indicator was attached to the connecting portion of the pipe and put into practical use, the white color due to the porous layer was visually recognized in the normal state (non-water absorption state), but water leaked from the connecting portion of the pipe. When it adheres to the back surface of the water discoloration indicator, the water-soluble dye contained in the colored layer elutes to the surroundings and the dot pattern becomes blurred, and it migrates to the transparent support and the porous layer and soaks into it. At the same time, the porous layer becomes transparent due to the liquid absorption, and the bleeding red dot pattern and the blue color due to the non-discoloring colored layer are visually recognized.
The state where water adheres shows the above-mentioned aspect, but when the porous layer dries, it returns to the original white state, but a pale red dot pattern due to the colored layer soaked into the porous layer is visually recognized, and water has been seen in the past. It was possible to determine that it had adhered.
Further, even if water adhered from the surface (porous layer side) of the indicator, the same aspect change could be visually recognized.

Example 7
^{As a blue water-soluble dye on one side of Japanese paper for inkjet printing (grain size: 50 g / m 2} , manufactured by Nippon Paper Industries Co., Ltd.), which has white water permeability and transparency (translucency) as a transparency support. 180 parts using screen printing ink containing 1.0 part of Brilliant Blue FCF-L (CI 42090), 30.0 parts of polyvinyl alcohol resin (trade name: Gosenol KL03, manufactured), and 70.0 parts of water. A lattice pattern was printed on a mesh screen plate and dried and cured at 130 ° C. for 5 minutes to form a colored layer.
The time required for water to reach the back surface of the transparent support by dropping 0.1 g of water from the front surface at room temperature (25 ° C.) was 10 seconds.
Next, on the other surface of the support, 15 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], vinyl chloride / vinyl acetate modified resin [trade name: solvent AL, Nissin Chemical Industry Co., Ltd.] 10 parts, petroleum-based aromatic hydrocarbon solvent [trade name: Solbesso 100, ExxonMobil Co., Ltd.] 15 parts, cyclohexanone 25 parts, surfactant 0.5 parts mixed The entire surface was solid-printed on a 100-mesh screen plate using the above-mentioned screen printing ink, and dried and cured at 60 ° C. for 30 minutes to form a porous layer.
Next, 1.0 part of pink pigment, 10 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], urethane emulsion [trade name: Hydran AP-10] on the porous layer. , Dainippon Ink Chemical Industry Co., Ltd., solid content 30%] 45 parts, water 40 parts, silicone-based defoaming agent 0.5 parts, water-based ink thickener 3 parts, ethylene glycol 1 part, isocyanate-based cross-linking Using a pink screen printing ink made by mixing 3 parts of the agent, solid printing is performed on the entire surface with a 180 mesh screen plate, and the product is dried and cured at 130 ° C. for 5 minutes to have water permeability and non-discoloration of pink. A colored layer was formed, and a water-insoluble adhesive layer made of a dot-shaped acrylic resin was further provided on the non-color-changing colored layer to obtain a water-color change indicator.

When the adhesive layer of the water discoloration indicator was attached to the connecting portion of the pipe and put into practical use, in a normal state (non-water absorption state), it was formed of a porous layer via a blue lattice pattern by a colored layer and a transparent support. White is visible, but when water leaks from the connecting part of the pipe and adheres to the back surface of the water discoloration indicator, the porous layer becomes transparent by absorbing liquid and the pink color due to the non-discoloration coloring layer is visually recognized. The water-soluble dye contained in the colored layer elutes to the surroundings, the lattice pattern becomes blurred, and the transparent support is transferred to the soaked state.
The state in which water adheres shows the above-mentioned aspect, but when the porous layer dries, it returns to the original white state, and only the blurred blue lattice pattern due to the colored layer is visually recognized, and it is determined that water has adhered in the past. I was able to.
In addition, the water discoloration indicator was able to visually recognize the same appearance change even if water adhered from the surface (colored layer side).

Example 8
Brilliant Blue FCF-L (CI 42090) 1.0 part as a blue water-soluble dye, polyvinyl alcohol resin (trade name: Gosenol KL03,) on one surface of a polyethylene terephthalate film having transparency as a transparency support. A lattice pattern was printed on a 180-mesh screen plate using a screen printing ink containing 30.0 parts and 70.0 parts of water, and dried and cured at 130 ° C. for 5 minutes to form a colored layer.
Next, on the other surface of the transparent support, 15 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], vinyl chloride / vinyl acetate modified resin [trade name: solvent AL, manufactured by Nissin Chemical Industry Co., Ltd.] 10 parts, petroleum-based aromatic hydrocarbon solvent [trade name: Solbesso 100, manufactured by ExxonMobil Co., Ltd.] 15 parts, cyclohexanone 25 parts, surfactant 0.5 parts Using the mixed ink for screen printing, the entire surface was solid-printed on a 100-mesh screen plate and dried and cured at 60 ° C. for 30 minutes to form a porous layer.
Next, 1.0 part of pink pigment, 10 parts of wet method fine particle silica [trade name: Nipseal E-220, manufactured by Nippon Silica Industry Co., Ltd.], urethane emulsion [trade name: Hydran AP-10] on the porous layer. , Dainippon Ink Chemical Industry Co., Ltd., solid content 30%] 45 parts, water 40 parts, silicone-based defoaming agent 0.5 parts, water-based ink thickener 3 parts, ethylene glycol 1 part, isocyanate-based cross-linking Using a pink screen printing ink made by mixing 3 parts of the agent, solid printing is performed on the entire surface with a 180 mesh screen plate, and the product is dried and cured at 130 ° C. for 5 minutes to have water permeability and non-discoloration of pink. A colored layer was formed, and a water-insoluble adhesive layer made of a dot-shaped acrylic resin was further provided on the non-color-changing colored layer to obtain a water-color change indicator.

When the adhesive layer of the water discoloration indicator was attached to the connecting portion of the pipe and put into practical use, in the normal state (non-water absorption state), the blue lattice pattern by the colored layer and the porous layer via the transparent support White is visible, but when water leaks from the connecting part of the pipe and adheres to the back surface of the water discoloration indicator, the porous layer becomes transparent due to liquid absorption, and the blue lattice pattern and the pink color due to the non-discoloration coloring layer appear. It is visually recognized.
The state in which water adhered shows the above-mentioned aspect, but when the porous layer dried, it returned to the original white state, and only the blue lattice pattern due to the colored layer was visually recognized.
Further, in the water discoloration indicator, when water adheres from the surface (colored layer side), the water-soluble dye contained in the colored layer elutes to the surroundings and the lattice pattern becomes blurred, and water adheres in the past. I was able to determine what was done.

1 Water discoloration indicator 2 Transparent support 3 Porous layer 4 Colored layer 5 Non-discolorable colored layer 6 Adhesive layer

Claims (8)

A colored layer that is solubilized with water on one surface of the transparent support, and a low refractive index pigment fixed to the binder resin in a dispersed state on the other surface. It is opaque in a non-liquid absorbing state and transparent in a liquid absorbing state. A water discoloration indicator provided with a porous layer to be formed, and the refractive index of the low refractive index pigment is in the range of 1.4 to 1.8. The water discoloration indicator according to claim 1, wherein the colored layer solubilized with water is a layer containing a water-soluble dye. The water discoloration indicator according to claim 2, wherein the colored layer solubilized with water is a layer containing a water-soluble dye and a binder resin. The water discoloration indicator according to claim 3, wherein the binder resin contains a water-soluble resin and a water-insoluble resin. The water discoloration indicator according to any one of claims 1 to 4, wherein the transparent support is a water-permeable support. The water discoloration indicator according to claim 5, wherein the transparent support is a support that exhibits water permeability in which 0.1 g of water is dropped on one surface and reaches the other surface within 60 seconds. The water discoloration indicator according to any one of claims 1 to 6, wherein a non-discoloration coloring layer is provided on the outer surface of the coloring layer or the porous layer. The water discoloration indicator according to any one of claims 1 to 7, wherein an adhesive layer is provided on a surface in contact with an object.

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