JP2011079253A - Water discoloration see-through sheet and water discoloration see-through sheet set using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water discoloration see-through sheet in which a sheet and a printed matter positioned at the lower part of a sheet do not shift easily when sprinkling water onto a porous layer, and which is superior in desired image forming quality and rich in practicality, and a water discoloration see-through sheet set using the same. <P>SOLUTION: A water discoloration sheet 1 makes the printed matter 5 located at the lower part either appear or disappear depending upon whether the sheet is sprinkled with water or dry and includes: a sheet body 3 which is composed of an upper support paper piece 31 with through-holes and a lower support paper piece 32 jointed together at the joint connection part and which holds a printed matter; and a water discoloration sheet 2 which has a porous layer 22 having low refractive index pigments fixed on binder resin in a dispersed condition and having different transparency in a liquid absorbed state and a liquid not-absorbed state formed on an upper surface of a transparent support 21, and the through-hole perimeter of the rear surface of the upper support paper piece and the perimeter of the side where the porous layer of the water discoloration sheet is prepared are adhered together. There also is provided the water discoloration see-through sheet set using the same. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a water-coloring fluoroscopic sheet that can clearly show a background picture due to adhesion of water, and a water-coloring fluoroscopic sheet set using the same.

Conventionally, there has been disclosed a water discoloring sheet provided with a porous layer in which a low refractive index pigment is fixed in a dispersed state in a binder resin on a transparent support (see, for example, Patent Document 1).
In the dry state, the printed material is not visually recognized by the porous layer when the sheet is placed in a dry state, and when the porous layer is wetted with water, the printed material is visually recognized, and when the porous layer is dried, the printed material is again printed. It is not visible.
However, when the sheet is only placed on the printed material, the adhesion between the sheet and the printed material is not sufficient, and when the hand or arm comes into contact with the sheet or the printed material, the sheet and the printed material are displaced and it is difficult to form a desired image. .

JP 2006-78932 A

  The present invention is a water-color-changing fluoroscopic sheet that allows a printed matter placed below to be clearly visible by application of water. When water is attached to a porous layer, the sheet and the printed matter placed below the sheet are not easily displaced and stable. It is an object of the present invention to provide a water-coloring fluoroscopic sheet that can form an image and a water-coloring fluoroscopic sheet set using the same.

The present invention is a water-color-changing sheet that conceals a printed matter placed below by adhesion and drying of water, and includes an upper mount piece provided with a through hole and a lower mount piece connected through a connecting portion. A sheet body for sandwiching the printed material, and a porous layer on the upper surface of the transparent support that has a low refractive index pigment fixed to a binder resin in a dispersed state and has a different transparency in a liquid absorbing state and a non-liquid absorbing state. And a water discolorable fluoroscopic sheet formed by adhering the periphery of the through hole on the back surface of the upper mount piece and the periphery of the water discolorable sheet on the side where the porous layer is provided.
Furthermore, the upper mount piece and the transparent support of the water discoloring sheet are directly attached, and the lower surface of the transparent support and / or the portion of the lower mount piece in contact with the transparency support is self-adhesive. It is required that an adhesive type adhesive layer is provided and that the self-adhesive type adhesive layer is made of a thermoplastic elastomer resin and a plasticizer.
Furthermore, a water discolorable fluoroscopic sheet set comprising the water discolorable fluoroscopic sheet and a water adhering tool is required.

  The present invention provides a water discolorable fluoroscopic sheet having excellent practical image forming properties and water discoloration, and a water discoloration using the same, in which when the water is adhered to the porous layer, the sheet and the printed material arranged below the sheet are not easily displaced. A transparent fluoroscopic sheet set can be provided.

It is longitudinal cross-sectional explanatory drawing of one Example of this invention water discolorable fluoroscopy sheet | seat. It is a perspective view of the water-color-changeable perspective sheet of FIG. It is longitudinal cross-sectional explanatory drawing which shows the state which has arrange | positioned printed matter to the water-color-changeable perspective sheet of FIG. It is longitudinal cross-sectional explanatory drawing which shows the state which has arrange | positioned and pinched the printed matter on the water-color-changeable perspective sheet of FIG. It is a perspective view which shows the state which formed the image using the water adhesion tool on the water-color-change fluoroscopic sheet | seat which has arrange | positioned and pinched | printed printed matter. It is a longitudinal cross-sectional explanatory drawing of the other Example of this invention water discolorable see-through | perspective sheet. It is a longitudinal cross-sectional explanatory drawing which shows the state which has arrange | positioned printed matter to the water-color-changeable perspective sheet of FIG. It is a longitudinal cross-sectional explanatory drawing which shows the state which has arrange | positioned and pinched the printed matter on the water-color-changeable perspective sheet of FIG. It is a longitudinal cross-sectional explanatory drawing of the other Example of this invention water discolorable see-through | perspective sheet. It is a longitudinal cross-sectional explanatory drawing of the other Example of this invention water discolorable see-through | perspective sheet. It is a longitudinal cross-sectional explanatory drawing of the other Example of this invention water discolorable see-through | perspective sheet.

The water discolorable sheet is provided with a porous layer having different transparency in a liquid absorbing state and a non-liquid absorbing state in which a low refractive index pigment is fixed to a binder resin in a dispersed state on an upper surface of a transparent support. .
The material of the transparent support is not particularly limited, and polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, polyacrylate, polystyrene, polycarbonate, cellulose triacetate, cellulose diacetate, polyvinyl alcohol, polyamide, vinyl chloride, and the like. Examples of the plastic sheet include polyethylene, polypropylene, polyethylene terephthalate, and vinyl chloride, which are excellent in flexibility and excellent in safety.
Although the shape of the said transparent support body is not specifically limited, It is preferable to set it as the shape matched with the shape of the through-hole provided in the upper mount piece mentioned later.
The transparent support may be translucent or colored and transparent.

The porous layer formed on the transparent support is a layer in which a low refractive index pigment is fixed in a dispersed state together with a binder resin.
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 white, magnesium carbonate, and the like. It is in the range of 1.8, and when the liquid composition is absorbed, good transparency is exhibited.
Examples of the silicic acid salt include aluminum silicate, aluminum potassium silicate, sodium aluminum silicate, aluminum calcium silicate, potassium silicate, calcium silicate, calcium sodium silicate, sodium silicate, magnesium silicate, and magnesium potassium silicate.
The particle diameter of the low refractive index pigment is not particularly limited, but a pigment having a thickness of 0.03 to 10.0 μm is preferably used.
Two or more of the low refractive index pigments can be used in combination.
In addition, silicic acid is mentioned as a low-refractive-index pigment used suitably, Although the silicic acid manufactured by a dry process may be sufficient, the silicic acid manufactured by a wet method (henceforth a wet process silicic acid) is especially effective. And satisfies practicality.
This point will be described below.
Silicic acid is produced as amorphous amorphous silicic acid, and according to its production method, a dry process using a gas phase reaction such as thermal decomposition of silicon halide such as silicon tetrachloride (hereinafter referred to as dry process silicic acid) These are roughly classified into those by a wet method using a liquid phase reaction such as decomposition by an acid such as sodium silicate. In order to function as a porous layer, a wet method silicic acid is suitable.
This is because the dry process silicic acid and the wet process silicic acid have different structures, and the dry process silicic acid forms a three-dimensional structure in which the silicic acid is closely bound, whereas the wet process silicic acid has a long molecular arrangement due to condensation of the silicic acid. It has a so-called two-dimensional structure portion formed.
Therefore, since the molecular structure is rough compared to dry process silicic acid, when wet process silicic acid is applied to the porous layer, it is superior in the diffused reflection of light in the dry state compared to the system using dry process silicic acid. It is presumed that the concealment property at the site will increase.
In addition, since the porous layer absorbs water, the wet method silicic acid has more hydroxyl groups present as silanol groups on the particle surface than the dry method silicic acid, and has a high degree of hydrophilicity. Used.
In order to adjust the concealability in the normal state of the porous layer and the transparency in the liquid absorption state, wet process silicic acid and other low refractive index pigments can be used in combination.

The low refractive index pigment in the porous layer depends on properties such as particle diameter, specific surface area, oil absorption, etc., in order to satisfy both the concealability in the normal state and the transparency in the liquid absorption state, The coating amount is preferably 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 concealability in a normal state, and if it exceeds 30 g / m ² , it is difficult to obtain sufficient transparency during liquid absorption.
The low refractive index pigment is dispersed in a vehicle containing a binder resin as a binder, and is applied to a substrate, and then the volatile matter is dried to form a porous layer.
Examples of the binder resin include urethane resin, nylon resin, vinyl acetate resin, acrylic ester resin, acrylic ester copolymer resin, acrylic polyol resin, vinyl chloride-vinyl acetate copolymer resin, maleic resin, 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 the above Each resin emulsion, casein, starch, cellulose derivative, polyvinyl alcohol, urea resin, phenol resin and the like can be mentioned.
The mixing ratio of the low refractive index pigment and these binder resins depends on the kind and properties of the low refractive index pigment, but preferably the binder resin solid content is 0.5 to 1 part by weight with respect to 1 part by weight of the low refractive index pigment. 2 parts by weight, more preferably 0.8 to 1.5 parts by weight. When the binder resin solid content is less than 0.5 parts by weight with respect to 1 part by weight of the low refractive index pigment, it is difficult to obtain a practical film strength of the porous layer, and the content exceeds 2 parts by weight. In this case, the water permeability into the porous layer is deteriorated.
Since the porous layer has a smaller mixing ratio of the binder resin to the colorant than a general coating film, it is difficult to obtain sufficient film strength. Therefore, in order to increase the scratch resistance, it is effective to use a nylon resin or a urethane resin among the binder resins.
Examples of the urethane resin include a polyester urethane resin, a polycarbonate urethane resin, and a polyether urethane resin, and two or more of them can be used in combination. In addition, a urethane emulsion resin in which the resin is emulsified and dispersed in water, or a colloid in which the resin is self-emulsified without the need for an emulsifier by an ionic group of the ionic urethane resin (urethane ionomer) itself and dissolved or dispersed in water. A dispersion type (ionomer type) urethane resin can also be used.
The urethane-based resin may be either an aqueous urethane-based resin or an oil-based urethane-based resin, but in the present invention, an aqueous urethane-based resin, particularly a urethane-based emulsion resin or a colloidally dispersed urethane-based resin is preferable. Used for.
The urethane resin can be used alone, but other binder resins can be used in combination depending on the type of support and the performance required for the coating. When a binder resin other than the urethane resin is used in combination, in order to obtain a practical film strength, it is preferable to contain 30% or more of the urethane resin in a solid content weight ratio in the binder resin of the porous layer. Among the binder resins, those having crosslinkability can be further improved in film strength by adding an arbitrary crosslinking agent and crosslinking.
The binder resin has a large or small affinity with water. 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. Furthermore, the said adjustment can be controlled by adding a dispersing agent suitably.

  The porous layer is a known means such as screen printing, offset printing, gravure printing, coater, tampo printing, transfer printing means, brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller It can be formed by coating, dip coating or the like.

The water discoloring sheet has a black sheet in close contact with the transparent support, the lightness value (Vd) measured when the porous layer is in a non-absorbing state, and the black sheet in close contact with the transparent support. It is preferable that the brightness value (Vw) measured when the porous layer is placed and the porous layer absorbs the liquid satisfies all the relational expressions (1) to (3).
The lightness value is measured according to JIS Z 8721-1993.
7.0 ≦ Vd ≦ 8.5 (1)
2.0 ≦ Vw ≦ 7.0 (2)
2.0 ≦ Vd−Vw ≦ 6.0 (3)
Explaining this in detail, the black sheet is closely arranged below, and the lightness value (Vd) measured in the non-absorbing state of the porous layer satisfies the formula (1), so that it is arranged below in the dry state. The color tone and outline of the printed material to be printed can be appropriately concealed.
When the lightness value (Vd) exceeds 8.5, the concealability of the porous layer is strong, and the color tone and outline of the printed material placed below are almost completely hidden, making it difficult to visually recognize the image. It is not suitable for a game of tracing along.
On the other hand, if the lightness value (Vd) is less than 7.0, the color tone and outline of the printed material placed below will be insufficiently concealed, and the printed material placed below will be clearly visible, reducing the interest of tracing. Become.
Further, the lightness value (Vw) in the liquid absorption state of the porous layer in the state where the black sheet is closely arranged below satisfies the formula (2), so that the color tone and contour of the printed material arranged below in the liquid absorption state Can be clearly seen. That is, when the lightness value (Vw) in the liquid absorption state exceeds 7.0, the color tone and outline of the printed material disposed below become unclear and inferior in visibility, so that the interest in tracing is halved.
Furthermore, when the relationship between the lightness value (Vd) and the lightness value (Vw) satisfies Expression (3), the difference in concentration between the non-liquid-absorbing state and the liquid-absorbing state can be clearly recognized. If Vd−Vw is less than 2.0, the difference between the non-liquid-absorbing state and the liquid-absorbing state is too small, and there is little change in the appearance before and after the game, which impairs the merchantability. Further, if Vd−Vw exceeds 6.0, the change in the appearance of the printed matter that is visually recognized in the non-liquid-absorbing state and the liquid-absorbing state becomes large, but generally the concealability in the non-liquid-absorbing state As the value increases (the lightness value increases), the lightness value in the liquid absorption state tends to increase.
In order to obtain a sheet suitable for tracing, the limit of 6 or less is the limit of the technology, and it can be said that it is actually difficult.
Therefore, the water discoloring sheet is placed in close contact with the black sheet below the transparent support, and the lightness value (Vd) measured in the non-absorbed state of the porous layer and the black sheet in close contact with the transparent support. The relationship between the brightness values (Vw) measured when the porous layer is placed in the liquid-absorbing state satisfies all of the formulas (1) to (3). The contour is appropriately concealed in the non-water-absorbing state, vividly visible in the water-absorbing state, and a sufficient density difference can be developed between the non-liquid-absorbing state and the liquid-absorbing state. This is an important requirement for applications where you want to trace along the contour of an image.

The water color-changing sheet is adhered to a sheet body composed of an upper mount piece provided with a through hole and a lower mount piece connected via a connecting portion.
The water discoloration sheet is attached to the periphery of the through hole on the back surface of the upper mount, and the periphery of the water discoloration sheet on the side where the porous layer is provided is attached.
Therefore, when the printed material is appropriately sandwiched between the sheet main body (between the upper mount piece and the lower mount piece), the water discoloration sheet and the printed matter adhered to the back surface of the upper mount piece are arranged in close contact with each other, and the porous layer Since it is possible to prevent the position of the water discoloration sheet and the printed matter from shifting due to the hands and arms coming into contact with the water discoloration sheet or the printed matter when water is attached to the child, and thus a desired image can be stably formed. Etc. can be used conveniently.
In addition, if the transparent backing of the upper backing sheet and the water discoloring sheet is directly attached, and the porous layer is not interposed at the attaching portion, the water attached to the porous layer is attached to the upper attaching portion of the attaching portion. It is difficult to leak from between the piece and the water discoloring sheet, it is difficult to cause a problem that water adheres to the printed matter, and the merchantability can be improved.
The sheet body is composed of an upper mount piece and a lower mount piece provided with through holes, and is connected via a connecting portion.
Examples of the connecting portion include a configuration in which an upper mount piece and a lower mount piece are integrated, and a configuration in which the upper mount piece and the lower mount piece are connected by an appropriate connecting member such as a ring-shaped member.
The material of the mount piece is not particularly limited, and a plastic sheet, water resistant paper, synthetic paper or the like is used.

A self-adhesive pressure-sensitive adhesive layer for fixing the printed matter can be provided at the lower surface of the transparent support and / or a portion of the lower mount piece in contact with the transparent support to further improve the image formability.
For the self-adhesive pressure-sensitive adhesive layer, a self-adhesive composition comprising a thermoplastic elastomer resin and a plasticizer can be applied.
In the composition, the thermoplastic elastomer component is plasticized by the plasticizer component, the cohesive force is reduced, and the self-adhesiveness is enhanced. “Self-adhesive” refers to the property that a sheet on which a pressure-sensitive adhesive layer consisting essentially of the composition is formed exhibits adhesiveness to the adherend surface under pressure due to its own weight.
Examples of the thermoplastic elastomer include those composed of a block segment composed of a block of a styrene monomer and a block of a rubber monomer.
The rubber monomer is a monomer constituting a natural rubber and a polymer generally called a synthetic rubber, and examples of the rubber monomer block include a polyisoprene block, a polybutylene block, and a poly (ethylene / butylene) block. Specific examples of the thermoplastic elastomer include polystyrene-polyisoprene-polystyrene (SIS), polystyrene-polybutylene-polystyrene (SBS), polystyrene-poly (ethylene / butylene) block-polystyrene (SEBS), polystyrene-poly (ethylene / ethylene / polyethylene). Examples include propylene) block-polystyrene (SEPS), polystyrene-polyisoprene (SI), polystyrene-polybutylene (SB), and polystyrene-poly (ethylene / propylene) block (SEP).
The plasticizer is selected as an effective material for adding self-adhesiveness to the elastomer, but if the thermoplastic elastomer used has a polystyrene phase and a rubber phase, it has an affinity for the rubber phase. A high molecular weight compound having a high affinity for the polystyrene phase is suitable. For example, naphthenic oil and / or paraffin oil is used.

As means for attaching water to the water-color-changing fluoroscopic sheet, a hand or a finger can be wetted with water and brought into contact with the porous layer, but a writing or applicator having a brush tip or a fiber pen body at the tip. A water adhering tool such as a writing or applicator provided with a fibrous body or brush for containing water in the container and leading out the water in the container can be used.
In addition, as a preferable water attachment tool, it is a writing tool or applicator which applied the plastic porous body or fiber processed body which has a continuous pore as a pen tip member, A writing image can be formed easily and practicality can be improved.
The plastic porous body or fiber processed body having continuous pores may be any material that absorbs and discharges water in an appropriate amount. Conventionally, a continuous pore body or fiber of various general-purpose polyolefin-based, polyurethane-based, or other various plastics can be used. Examples include a focused brush-like one, a fiber processed by resin processing or heat welding, a felt, and a non-woven fabric, and the shape and dimensions can be arbitrarily set.
A water-coloring fluoroscopic sheet set is obtained by combining the water applicator and the water-coloring fluoroscopic sheet, and portability and convenience can be satisfied.

Examples are shown below, but the present invention is not limited thereto. In addition, the part in an Example shows a mass part.
Example 1 (see FIGS. 1 to 5)
On the surface of a polyethylene terephthalate sheet (thickness 150 μm, 16 cm × 21 cm) as a transparent support 21, 15 parts of a wet process silicic acid [trade name: NIPSEAL E-200, manufactured by Nippon Silica Kogyo Co., Ltd.], urethane emulsion [trade name] : Hydran HW-930, manufactured by Dainippon Ink & Chemicals, Inc., solid content 50%] 30 parts, water 50 parts, silicone-based antifoaming agent 0.5 parts, aqueous ink thickener 3 parts, ethylene glycol 1 Using a white screen printing ink that is uniformly mixed and stirred with 3 parts of a blocked isocyanate-based crosslinking agent, the entire surface is solid-printed on a 120 mesh screen plate, dried and cured at 130 ° C. for 5 minutes, and porous. A quality layer 22 was formed to obtain a water-discoloring sheet 2.
A black sheet having a lightness value of 2.5 was closely arranged below the water discoloring sheet, and the lightness value (Vd) when the porous layer was in a non-liquid-absorbing state was 8.2.
Similarly, a lightness value (Vw) in a water absorption state in which a black sheet having a lightness value of 2.5 was closely arranged below the sheet and the porous layer was impregnated with water was 6.1.
Therefore, Vd−Vw of the formula (3) was 2.1.
The brightness value was measured using a color difference meter [TC3600 type color difference meter, manufactured by Tokyo Denshoku Co., Ltd.].
Separately from this, a sheet body 3 made of an upper mount piece 31 made of white synthetic paper (25 cm × 35 cm) and a lower mount piece 32 connected via a connecting portion was produced.
The upper mount piece of the sheet body is provided with a through hole (15 cm × 20 cm).
Adhesive was applied to the periphery of the through hole on the back surface of the upper mount to provide an adhesive layer 4, and adhered to the periphery of the water discolorable sheet on the side where the porous layer was provided to obtain a water discolorable fluoroscopic sheet 1. (See FIGS. 1 and 2).

A rainbow-colored (red, orange, yellow, green, blue, indigo, purple) printed material 5 is placed between the upper and lower mount pieces of the water-coloring fluoroscopic sheet, and is visible from above the sheet. Then, a white porous layer is visually recognized in a dry state.
When water is attached from the porous layer of the water-color-changing fluoroscopic sheet using a pen configured to accommodate water in the shaft cylinder as the water adhering tool 6, the porous layer changes to a transparent state by liquid absorption, A clear rainbow-colored handwriting is visually recognized and maintained in the liquid-absorbing state, but the original white porous layer is visually recognized as the water evaporates and dries (see FIGS. 3 to 5).
In addition, when writing with the water adhering tool, the hand or arm only touches the upper mount piece, and does not touch the water-coloring sheet or printed matter. A water discolorable see-through sheet excellent in formability was obtained.

Example 2
A water-coloring fluoroscopic sheet set obtained in Example 1 was combined with a pen configured to be able to store water in the shaft tube as a water attachment tool to obtain a water-coloring fluoroscopic sheet set.
In the water discolorable fluoroscopic sheet set, as in Example 1, when water was attached using a water attachment tool, the porous layer changed to a transparent state by liquid absorption, and a clear rainbow-colored handwriting was visually recognized. In the liquid state, this state is maintained, but the original white porous layer is visually recognized by evaporating and drying the water.
Further, when writing with the water adhering tool, the hand or arm only touches the upper mount piece, and does not touch the water-coloring sheet or printed matter. A water discolorable fluoroscopic sheet set having excellent formability and portability was obtained.

Example 3
As a transparent support 21, on the surface of a soft vinyl chloride sheet (thickness 200 μm, 16 cm × 21 cm), 15 parts of wet process silicic acid [trade name: Nipseal E-200, manufactured by Nippon Silica Kogyo Co., Ltd.], urethane emulsion [commodity Name: Hydran AP-10, manufactured by Dainippon Ink & Chemicals, Inc., solid content 30%] 45 parts, water 40 parts, silicone antifoam 0.5 parts, aqueous ink thickener 3 parts, ethylene 1 part of glycol and 3 parts of isocyanate cross-linking agent were mixed and stirred in white screen printing ink, printed on a 230-mesh screen plate leaving the periphery, and dried and cured at 50 ° C. for 30 minutes. The porous layer 22 was formed to obtain the water discoloring sheet 2.
A black sheet having a lightness value of 2.5 was closely arranged below the color-changing see-through writing sheet, and the lightness value (Vd) when the porous layer was in a non-liquid-absorbing state was 7.3.
Similarly, a lightness value (Vw) in a water absorption state in which a black sheet having a lightness value of 2.5 was closely arranged below the sheet and the porous layer was impregnated with water was 4.2.
Therefore, Vd−Vw of the formula (3) was 3.1.
The brightness value was measured using a color difference meter [TC3600 type color difference meter, manufactured by Tokyo Denshoku Co., Ltd.].
Separately from this, a sheet body 3 composed of an upper mount piece 31 made of blue synthetic paper (25 cm × 35 cm) and a lower mount piece 32 connected via a connecting portion was produced.
The upper mount piece of the sheet body is provided with a through hole (15 cm × 20 cm).
An adhesive is applied around the through hole on the back surface of the upper mount to provide an adhesive layer 4, which is adhered to a transparent support on the side where the porous layer of the water discolorable sheet is provided, and the water discolorable fluoroscopic sheet 1. Was obtained (see FIG. 6).

When the printed matter 5 on which the blue “ABC” characters are printed is placed and sandwiched between the upper mount piece and the lower mount piece of the water-color-changing fluoroscopic sheet, and it is visually confirmed on the sheet, “ABC” in the dry state. The outline and color tone of the characters are slightly visible (see FIGS. 7 and 8).
When water is attached from above the porous layer of the water discolorable see-through sheet using a pen configured to accommodate water in the shaft cylinder as the water attachment tool 6, the porous layer changes to a transparent state by liquid absorption and becomes clear. Blue characters are visually recognized and maintained in the liquid-absorbing state, but when the water is evaporated and dried, the original characters are slightly visually recognized.
Further, when writing with the water adhering tool, the hand or arm only touches the upper mount piece, and does not touch the water-coloring sheet or printed matter. A water discolorable see-through sheet excellent in formability was obtained.

Example 4
A water-coloring fluoroscopic sheet set obtained in Example 3 was combined with a pen that was configured to be able to accommodate water in the shaft tube as a water attachment tool to obtain a water-coloring fluoroscopic sheet set.
In the water discolorable fluoroscopic sheet set, the porous layer is changed to a transparent state by liquid absorption when water is adhered using a water adhering tool in the same manner as in Example 3, and clear blue characters are visually recognized. Although the state is maintained in the state, the original character is slightly visually recognized as the water evaporates and dries.
Further, when writing with the water adhering tool, the hand or arm only touches the upper mount piece, and does not touch the water-coloring sheet or printed matter. A water discolorable fluoroscopic sheet set having excellent formability and portability was obtained.

Example 5
As a transparent support 21, a polyethylene terephthalate sheet (thickness: 100 μm, circular shape with a diameter of 15 cm) has a wet process silicic acid [trade name: NIPSEAL E-200A, manufactured by Nippon Silica Kogyo Co., Ltd.], urethane emulsion [commodity] Name: Hydran AP-20, manufactured by Dainippon Ink & Chemicals, Inc., solid content 30%] 45 parts, water 40 parts, silicone antifoam 0.5 parts, aqueous ink thickener 3 parts, ethylene 1 part of glycol and 3 parts of isocyanate cross-linking agent were mixed and stirred uniformly, printed on a 180-mesh screen plate with white screen printing ink, and dried and cured at 50 ° C. for 30 minutes. A porous layer 22 was formed.
A black sheet having a lightness value of 2.5 was closely arranged below the color-changing see-through writing sheet, and the lightness value (Vd) when the porous layer was in a non-liquid-absorbing state was 7.7.
Similarly, a lightness value (Vw) in a water absorption state in which a black sheet having a lightness value of 2.5 was closely arranged below the sheet and water was impregnated into the porous layer was 3.0.
Therefore, Vd−Vw in the formula (3) was 4.7.
The brightness value was measured using a color difference meter [TC3600 type color difference meter, manufactured by Tokyo Denshoku Co., Ltd.].
Separately from this, a sheet body 3 made of an upper mount piece 31 made of green synthetic paper (20 cm × 30 cm) and a lower mount piece 32 connected via a connecting portion was produced.
In addition, the upper mount piece of the sheet main body is provided with a through hole (circular with a diameter of 14 cm), and the lower mount piece is provided with a self-adhesive adhesive layer 7.
An adhesive is applied around the through hole on the back surface of the upper mount to provide an adhesive layer 4, which is adhered to a transparent support on the side where the porous layer of the water discolorable sheet is provided, and the water discolorable fluoroscopic sheet 1. Was obtained (see FIG. 9).

When the printed matter 5 on which the doll pattern is printed is placed between the upper mount piece and the lower mount piece of the water-coloring fluoroscopic sheet and is sandwiched and visually confirmed on the sheet, the outline of the characters “ABC” in the dry state The color tone is slightly visible.
When water is attached from the porous layer of the water-color-changing fluoroscopic sheet using a pen configured to be able to contain water as a water attachment tool in the shaft tube, the porous layer changes to a transparent state due to liquid absorption and becomes clear. The pattern of the doll is visually recognized, and the state is maintained in the liquid absorption state. However, when the water is evaporated and dried, the pattern of the original doll is slightly visually recognized.
Further, when writing with the water adhering tool, the hand or arm only touches the upper mount piece, does not touch the water-coloring sheet or printed matter, and the printed matter is fixed by the self-adhesive adhesive layer. Therefore, a water-discoloring fluoroscopic sheet excellent in image forming property was obtained without causing any deviation between the sheet and the printed matter.

Example 6
A water-coloring fluoroscopic sheet set obtained in Example 5 was combined with a pen that was configured to be able to accommodate water in a shaft tube as a water attachment tool to obtain a water-coloring fluoroscopic sheet set.
When the water discolorable fluoroscopic sheet set is attached with water using a water adhering tool in the same manner as in Example 5, the porous layer is changed to a transparent state by liquid absorption, and a clear doll pattern is visually recognized. Although the state is maintained in the state, the water changes to a state where the pattern of the original doll is slightly visible as the water evaporates and dries.
Further, when writing with the water adhering tool, the hand or arm only touches the upper mount piece, and does not touch the water-coloring sheet or printed matter. A water discolorable fluoroscopic sheet set having excellent formability and portability was obtained.

Example 7
As a transparent support 21, on the surface of a polymethyl methacrylate sheet (thickness 1 mm, 11 cm × 16 cm), 12 parts wet type silicic acid [trade name: Nipseal E-200A, manufactured by Nippon Silica Kogyo Co., Ltd.], urethane emulsion [product Name: Hydran AP-20, manufactured by Dainippon Ink & Chemicals, Inc., solid content 30%] 40 parts, water 35 parts, silicone-based antifoaming agent 0.5 part, water-based ink thickener 3 parts, ethylene 1 part of glycol and 3 parts of isocyanate-based cross-linking agent are printed on a 180-mesh screen plate using a white screen printing ink that is uniformly mixed and stirred, and dried and cured at 50 ° C. for 30 minutes. The porous layer 22 was formed, and the self-adhesive adhesive layer 7 was formed on the back surface of the support.
A black sheet having a lightness value of 2.5 was closely arranged below the water discoloring sheet, and the lightness value (Vd) when the porous layer was in a non-liquid-absorbing state was 7.1.
Similarly, a lightness value (Vw) in a water absorption state in which a black sheet having a lightness value of 2.5 was closely arranged below the sheet and the porous layer was impregnated with water was 2.3.
Therefore, Vd−Vw in the formula (3) was 4.8.
The brightness value was measured using a color difference meter [TC3600 type color difference meter, manufactured by Tokyo Denshoku Co., Ltd.].
Separately from this, a sheet body 3 composed of an upper mount piece 31 made of green synthetic paper (15 cm × 20 cm) and a lower mount piece 32 connected via a connecting portion was produced.
The upper mount piece of the sheet body is provided with a through hole (10 cm × 15 cm).
An adhesive is applied around the through hole on the back surface of the upper mount to provide an adhesive layer 4, which is adhered to a transparent support on the side where the porous layer of the water discolorable sheet is provided, and the water discolorable fluoroscopic sheet 1. Was obtained (see FIG. 10).

When the printed matter 5 on which the orange number “123” is printed is placed and sandwiched between the upper mount piece and the lower mount piece of the water-coloring fluoroscopic sheet, and it is visually confirmed on the sheet, it is “123” in the dry state. The outline and color tone of the numbers are slightly visible.
When water is attached from the porous layer of the water-color-changing fluoroscopic sheet using a pen configured to be able to contain water as a water attachment tool in the shaft tube, the porous layer changes to a transparent state due to liquid absorption and becomes clear. An orange number is visually recognized, and the state is maintained in the liquid absorption state, but when the water is evaporated and dried, the original number is changed to a state where the number is visually recognized.
Further, when writing with the water adhering tool, the hand or arm only touches the upper mount piece, does not touch the water-coloring sheet or printed matter, and the printed matter is fixed by the self-adhesive adhesive layer. Therefore, a water-coloring see-through sheet excellent in image formability was obtained without causing a shift between the water-coloring sheet and the printed material.

Example 8
A water-coloring fluoroscopic sheet set obtained in Example 7 was combined with a pen configured to accommodate water in a shaft tube as a water adhering tool to obtain a water-coloring fluoroscopic sheet set.
In the water discolorable fluoroscopic sheet set, as in Example 7, when water was attached using a water attachment tool, the porous layer changed to a transparent state by liquid absorption, and clear orange numbers were visually recognized. In the state, the state is maintained, but when the water evaporates and drys, the original number changes slightly.
Further, when writing with the water adhering tool, the hand or arm only touches the upper mount piece, and does not touch the water-coloring sheet or printed matter. A water discolorable fluoroscopic sheet set having excellent formability and portability was obtained.

Example 9
On the surface of a polyethylene terephthalate sheet (thickness 150 μm, 26 cm × 36 cm) as a transparent support 21, 12 parts of a wet process silicic acid [trade name: NIPSEAL E-200A, manufactured by Nippon Silica Kogyo Co., Ltd.], urethane emulsion [trade name] : Hydran AP-20, manufactured by Dainippon Ink & Chemicals, Inc., solid content 30%] 40 parts, water 35 parts, silicone antifoam 0.5 parts, aqueous ink thickener 3 parts, ethylene glycol 1 part and 3 parts of an isocyanate-based cross-linking agent are uniformly mixed and stirred using white screen printing ink, printed on a 180 mesh screen plate, leaving the periphery, and dried and cured at 50 ° C. for 30 minutes. The porous layer 22 was formed, and the self-adhesive adhesive layer 7 was formed on the back surface of the support.
A black sheet having a lightness value of 2.5 was closely arranged below the water discoloring sheet, and the lightness value (Vd) when the porous layer was in a non-liquid-absorbing state was 7.5.
Similarly, a lightness value (Vw) in a water absorption state in which a black sheet having a lightness value of 2.5 was closely arranged below the sheet and the porous layer was impregnated with water was 2.5.
Therefore, Vd−Vw of the formula (3) was 5.0.
The brightness value was measured using a color difference meter [TC3600 type color difference meter, manufactured by Tokyo Denshoku Co., Ltd.].
Separately from this, a sheet body 3 composed of an upper mount piece 31 made of green synthetic paper (30 cm × 40 cm) and a lower mount piece 32 connected through a connecting portion was produced.
The upper mount piece of the sheet main body is provided with a through hole (25 cm × 35 cm), and the lower mount piece is provided with a self-adhesive adhesive layer 7.
An adhesive is applied around the through hole on the back surface of the upper mount to provide an adhesive layer 4, which is adhered to a transparent support on the side where the porous layer of the water discolorable sheet is provided, and the water discolorable fluoroscopic sheet 1. Was obtained (see FIG. 11).

When the printed matter 5 on which the flower pattern is printed is placed and sandwiched between the upper mount piece and the lower mount piece of the water-colorable fluoroscopic sheet, and the sheet is viewed on the sheet, the outline and color tone of the flower pattern in the dry state Is slightly visible.
When water is attached from the porous layer of the water-color-changing fluoroscopic sheet using a pen configured to be able to contain water as a water attachment tool in the shaft tube, the porous layer changes to a transparent state due to liquid absorption and becomes clear. The flower pattern is visually recognized and maintained in the liquid-absorbing state, but when the water evaporates and drys, the outline and color tone of the original flower pattern changes slightly.
Further, when writing with the water adhering tool, the hand or arm only touches the upper mount piece, does not touch the water-coloring sheet or printed matter, and the printed matter is fixed by the self-adhesive adhesive layer. Therefore, a water-coloring see-through sheet excellent in image formability was obtained without causing a shift between the water-coloring sheet and the printed material.

Example 10
A water-coloring fluoroscopic sheet set obtained in Example 9 was combined with a pen that was configured to be able to store water in a shaft tube as a water attachment tool to obtain a water-coloring fluoroscopic sheet set.
When the water discolorable fluoroscopic sheet set is attached with water using a water adhering tool as in Example 9, the porous layer is changed to a transparent state by liquid absorption, and a clear flower pattern is visually recognized. In the state, the state is maintained, but when the water evaporates and drys, the outline and color tone of the original flower pattern are slightly visible.
Further, when writing with the water adhering tool, the hand or arm only touches the upper mount piece, and does not touch the water-coloring sheet or printed matter. A water discolorable fluoroscopic sheet set having excellent formability and portability was obtained.

Comparative Example 1
As a transparent support, on the surface of a soft vinyl chloride sheet (thickness: 200 μm, 16 cm × 21 cm), 15 parts of wet process silicic acid [trade name: Nipseal E-200, manufactured by Nippon Silica Kogyo Co., Ltd.], urethane emulsion [trade name : Hydran AP-10, manufactured by Dainippon Ink & Chemicals, Inc., solid content 30%] 45 parts, water 40 parts, silicone antifoam 0.5 parts, aqueous ink thickener 3 parts, ethylene glycol 1 part and 3 parts of isocyanate cross-linking agent are mixed and stirred with white screen printing ink, printed on a 230 mesh screen plate and dried and cured at 50 ° C. for 30 minutes to form a porous layer. Thus, a water discoloring sheet was obtained.
A black sheet having a lightness value of 2.5 was closely arranged below the color-changing see-through writing sheet, and the lightness value (Vd) when the porous layer was in a non-liquid-absorbing state was 7.3.
Similarly, a lightness value (Vw) in a water absorption state in which a black sheet having a lightness value of 2.5 was closely arranged below the sheet and the porous layer was impregnated with water was 4.2.
Therefore, Vd−Vw of the formula (3) was 3.1.
The brightness value was measured using a color difference meter [TC3600 type color difference meter, manufactured by Tokyo Denshoku Co., Ltd.].

When a printed matter on which blue “ABC” characters are printed is placed below the water-coloring fluoroscopic sheet and viewed from above the sheet, the outline and color tone of the characters “ABC” are slightly visible in the dry state.
When water is attached from the porous layer of the water discolorable fluoroscopic sheet using a pen configured to accommodate water as a water attachment tool in the shaft tube, the porous layer changes to a colorless and transparent state by liquid absorption, A clear blue character is visually recognized, and the state is maintained in the liquid absorption state, but the original character is slightly visually recognized as the water evaporates and dries.
However, when writing with the water adhering tool, the hand or arm touched the sheet and the printed material and the sheet were displaced, and satisfactory image forming properties could not be satisfied.

DESCRIPTION OF SYMBOLS 1 Water discoloration see-through sheet 2 Water discoloration sheet 21 Transparency support body 22 Porous layer 3 Sheet | seat main body 31 Upper mount piece 32 Lower mount piece 4 Adhesive layer 5 Printed matter 6 Water adhesion tool 7 Self-adhesive type adhesive layer

Claims (6)

  A water-color-changing sheet that conceals the printed matter placed below due to water adhesion and drying, and sandwiches the printed matter comprising an upper mount piece provided with a through hole and a lower mount piece connected via a connecting portion. Water discoloration with a sheet body to be used and a porous layer with a low refractive index pigment adhering to a binder resin in a dispersed state on the upper surface of a transparent support and having a different transparency between a liquid absorbing state and a non-liquid absorbing state A water discoloration see-through sheet comprising a sheet, and is formed by adhering the periphery of the through hole on the back surface of the upper mount piece and the periphery of the water discoloration sheet on which the porous layer is provided.   The water-coloring see-through sheet according to claim 1, wherein the upper mount piece and a transparent support of the water-coloring sheet are directly attached.   The water-color-changeable fluoroscopic sheet set according to claim 1 or 2, wherein a self-adhesive adhesive layer is provided on a lower surface of the transparent support and / or a portion of the lower mount piece in contact with the transparent support.   The water discolorable see-through sheet set according to claim 3, wherein the self-adhesive adhesive layer comprises a thermoplastic elastomer resin and a plasticizer.   A water-coloring see-through sheet set comprising the color-changing see-through writing sheet according to claim 1 and a water adhering tool.   The water discolorable fluoroscopic sheet set according to claim 5, wherein the water adhering tool is a writing instrument or an applicator to which a plastic porous body or a fiber processed body having continuous pores is applied as a pen tip member.

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