JP2006098285A - Reversible moisture indicator for soil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reversible moisture indicator for soil that can accurately indicate a change in moisture in the soil for cultivating plants and the soil for keeping insects by selecting a water absorption material having water absorption force to the purpose of use, and can freely select color visually recognized by moisture detection. <P>SOLUTION: The reversible moisture indicator for soil comprises the water absorption material 2 at least partially inserted into the soil; and a porous layer 3 laminated at a position in contact with the water absorption material 2. The porous layer 3 has different transparency between a liquid-absorbed state and a non-liquid-absorbed state in which pigment having a low refractive index is stuck to a binder resin in a dispersed state. Or the reversible moisture indicator for soil comprises the water absorption material 2 at least partially inserted into the soil; a water permeable layer 5 laminated at a position in contact with the water absorption material; and the porous layer 3 laminated on the water permeable layer 5. The porous layer has different transparency between the liquid-absorbed state and the non-liquid-absorbed state in which the pigment having a low refractive index is stuck to the binder resin in a dispersed state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a reversible moisture indicator for soil. More specifically, the present invention relates to a reversible moisture indicator for soil showing different aspects in a dry state and a liquid absorption state.

Conventionally, in order to visually represent the timing of watering a potted plant or a nursery, a moisture indicator using a water-sensitive color changing material such as cobalt chloride that chemically changes color when contacted with water has been disclosed (for example, patents) References 1 and 2).
JP 10-267852 A Utility model No. 3036850

However, the water-sensitive color-changing material is excellent in reactivity with water, and when the trace amount of water is detected, the color is instantly changed, and the color is easily changed by water vapor evaporated from the soil or indoor humidity change. However, it was not possible to accurately show the moisture change in the soil where the plant is grown, and the accuracy of the indicator could not be increased due to the material and density of the water-absorbing material.
Moreover, since only a specific color change can be performed, the color of a discoloration part was not able to be selected with the color of the plant or flower to grow.

  The present invention can accurately show the water change in the soil for cultivating plants and the soil for raising insects by selecting a water absorbing material having a water absorbing power according to the purpose of use, and is visually recognized by moisture detection. It is intended to provide a reversible moisture indicator for soil in which the color to be selected can be freely selected.

The present invention is a soil reversible moisture indicator comprising at least a part of a water-absorbing material inserted into soil and a porous layer laminated at a position in contact with the water-absorbing material, wherein the porous layer comprises It is a requirement that the transparency is different between a liquid absorption state in which a low refractive index pigment is fixed to a binder resin in a dispersed state and a non-liquid absorption state.
Furthermore, a reversible moisture indicator for soil, comprising a water absorbing material at least partially inserted into the soil, a water permeable layer laminated at a position in contact with the water absorbing material, and a porous layer laminated on the water permeable layer. In addition, it is a requirement that the porous layer has a configuration in which transparency is different between a liquid absorbing state in which a low refractive index pigment is fixed to a binder resin in a dispersed state and a non-liquid absorbing state. Furthermore, it is a requirement that the water permeable layer is selected from a porous paper, a fabric, and a porous film.
Furthermore, it is required that a colored layer is provided below the porous layer, and that the porous layer is provided on the upper or middle part of the water-absorbing material inserted into the soil from below.

  According to the present invention, it is possible to accurately show the moisture change in the soil for plant cultivation and insect breeding, and can be formed without limiting the color and image visually recognized when moisture is detected. A high soil reversible moisture indicator can be provided.

  The reversible moisture indicator for soil of the present invention is composed of at least a water absorbing material and a porous layer provided at a position in contact with the water absorbing material, and is not affected by water vapor evaporated from the soil or changes in humidity. When the water in the soil is pulled upward via the water absorbing material inserted in the soil, the water content in the soil is instantly transparentized by this water. Can be visually confirmed.

Examples of the water-absorbing material are those capable of sucking liquid from the bottom to the top, specifically, porous (fiber convergence) paper such as filter paper, Japanese paper, cushion paper, and fiber bundles that have been processed with resin or heat-sealed. Examples include fiber processed bodies (fiber converging bodies), felts, fabrics, non-woven fabrics, and plastic porous bodies having continuous pores.
The water-absorbing material may be a colored one, and further, a portion where the porous layer is not formed (that is, a portion visually recognized in a non-liquid-absorbing state) such as a picture, a character, a pattern, a scale, etc. An image can also be formed. These are excellent in decorativeness and become an interesting indicator.

The porous layer laminated on the water-permeable material at a position in direct contact with the water-absorbing material is a layer in which a low refractive index pigment is fixed together with a binder resin in a dispersed state.
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 salt of silicic acid include aluminum silicate, aluminum calcium silicate, sodium aluminum silicate, aluminum potassium silicate, potassium silicate, magnesium silicate, sodium silicate, and magnesium potassium silicate.
The particle size of the low refractive index pigment is not particularly limited, but 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.
The silicic acid may be obtained by a dry process, but silicic acid produced by a wet process (hereinafter referred to as wet process silicic acid) is particularly 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) In general, the wet process silicic acid is most suitable for the purpose of functioning as the porous layer intended by the present invention. .
This is because the dry process silicic acid and the wet process silicic acid have different structures. The dry process silicic acid forms a three-dimensional structure in which the silicic acid is closely bound, whereas the wet process silicic acid is long due to condensation of silicic acid. It has a so-called two-dimensional structure part that forms a molecular arrangement.
Therefore, since the molecular structure becomes rough compared to the dry method silicic acid, when wet method silicic acid is applied to the porous layer, it is excellent in the diffused reflection of light in the dry state compared to the system using the dry method silicic acid, Therefore, it is guessed that the concealment property in a normal state becomes large.
In addition, since the porous layer of the present invention absorbs water, the wet process silicic acid has more hydroxyl groups present as silanol groups on the particle surface than the dry process silicic acid, and has a high degree of hydrophilicity. And is preferably used.
In addition, in order to adjust the concealability in the normal state of the porous layer and the transparency in the liquid absorption state, other general-purpose low-refractive-index pigments can be used in combination with the wet method silicic acid.

The wet process silicic acid in the porous layer depends on properties such as particle size, specific surface area, oil absorption, etc., but in order to satisfy both the concealing property in the normal state and the transparency in the liquid absorbing state, it is applied. preferably the amount is ^{1g / m 2 ~30g / m 2} , more preferably ^{5g / m 2 ~20g / 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 upon liquid absorption.
The particle size of the silicic acid is not particularly limited, but 0.03 to 10.0 μm is preferably used.
The silicic acid is dispersed in a vehicle containing a binder resin as a binder, applied to a base material, 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 silicic acid and these binder resins depends on the type and properties of silicic acid, but is preferably 0.5 to 2 parts by weight of binder resin solids, more preferably 1 part by weight of silicic acid. 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 silicic acid, it is difficult to obtain a practical film strength of the porous layer, and when it exceeds 2 parts by weight, The permeability of water into the porous layer is deteriorated.
Since the porous layer has a small mixing ratio of the binder resin to the colorant as compared with a conventionally known 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, in particular, a urethane-based emulsion resin or a colloidally dispersed urethane-based resin is suitable. 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.
In the binder resin, the crosslinkable resin 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 penetration time into the porous layer, the degree of penetration, and the slow speed of drying after the penetration can be adjusted. Furthermore, the said adjustment can be controlled by adding a dispersing agent suitably.

In the porous layer, conventionally known titanium dioxide-coated mica, iron oxide-titanium dioxide-coated mica, iron oxide-coated mica, guanine, sericite, basic lead carbonate, acidic lead arsenate, bismuth oxychloride, etc. The color change can be diversified by adding a metallic luster pigment or mixing general dyes and pigments, fluorescent dyes and fluorescent pigments.
In addition, conventionally known reversible thermochromic pigments that reversibly change color according to temperature change can be mixed, and the color can be changed depending on the environmental temperature or the water temperature to be adhered.
Furthermore, a non-discoloring layer can be disposed on and / or in the vicinity of the porous layer to further diversify the change in appearance.

  The porous layer is a conventionally known means, for example, printing means such as screen printing, offset printing, gravure printing, coater, tampo printing, transfer, brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating. It can be appropriately formed on the water-absorbing material or the colored layer by roller coating, immersion coating or the like.

The porous layer is not limited to a solid print, and may be an image such as a character, a symbol, or a design pattern. In particular, by forming the pattern pattern densely arranged, the color tone of the non-laminated portion of the porous layer can be visually recognized even in a non-liquid-absorbing state, and the design is improved.
Closely arranged patterns include dots, circles, ellipses, polygons, stars, hearts, etc., checkered pattern, turtle shell pattern, chain pattern, geometric pattern, lattice pattern, mesh pattern, stitch pattern A pattern, canvas-like pattern, denim-like pattern, or other image or design pattern can be formed in an independent state or in a state of partial contact.

Moreover, the water permeable layer which consists of a member which has liquid permeability can also be laminated | stacked on a water absorbing material by means, such as adhesion | attachment and crimping | compression-bonding. In the case of using the water permeable layer, it is possible to produce a laminate formed by forming a porous layer or a colored layer on the water permeable layer, and then to laminate the laminate on a water absorbing material. A clear colored layer can be easily formed using a general-purpose method such as the above, and vivid color changes can be visually recognized. Further, when an image is formed as a colored layer, even a fine design can be formed by printing, so that a rich and delicate image can be displayed.
The application of the water-permeable layer is particularly useful when the water-absorbing material is three-dimensional and the surface has a curved surface.
For the water permeable layer, a liquid permeable member capable of allowing liquid to pass through the member is used. For example, a porous material exemplified as the water absorbing material or a plurality of fine through holes in the resin film Or the porous film etc. which provide a communicating hole can be illustrated.
In particular, porous paper, fabric, and porous film are preferably used because they are excellent in processability and printing performance.
When an adhesive is used when laminating the water permeable layer, it is preferable to apply an adhesive having water permeability, but the water permeable layer and the water absorbing material are in direct contact with each other by partially applying an adhesive having poor water permeability. It is also possible to provide a portion to perform.

Furthermore, a colored layer can be laminated on the upper layer of the water-absorbing material or water-permeable layer (lower layer of the porous layer). The said colored layer is provided by apply | coating a coloring material directly on a water absorbing material or a water-permeable layer in the state of a paint etc., or using a colored water-permeable layer.
The colored layer is not limited to a solid print, and may be an image such as a character, a symbol, or a design pattern. By providing the colored layer, various colors and images can be visually recognized in the liquid absorption state of the porous layer, and the decoration effect is high.

Furthermore, it is also possible to improve the strength by providing a substrate on the water absorbing material. In particular, it is useful when soft materials such as papers, felts, and nonwoven fabrics are used as the water-absorbing material, and can prevent breakage and breakage that are likely to occur when inserted into soil.
As the base material, water-resistant materials such as polyethylene resin, polypropylene resin, polystyrene resin, ABS resin, AS resin, polyethylene terephthalate resin, phenol resin, melamine resin, urea resin, wood, metal member, etc. Is applicable. Moreover, when the said resin member is used, the outer surface of a water absorbing material and a porous layer can also be coat | covered in the state which open | released only the lower end part of the water absorbing material at least.

  The base material and the water-absorbing material can be provided with a label portion for describing a photograph or name of a plant or a date, or a scale for displaying a more accurate water amount.

  Examples are shown below, but the present invention is not limited to the examples. In addition, the part in an Example shows a weight part.

Example 1 (see FIG. 1)
As a support (water-absorbing material 2), red cushion paper having a thickness of 1 mm is used. On the entire surface of the cushion paper, 15 parts of wet-process fine powder silica [trade name: NIPSEAL E-200, manufactured by Nippon Silica Industry 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 part, thickener for water-based ink 3 parts, 1 part of ethylene glycol and 3 parts of an isocyanate cross-linking agent are uniformly mixed and agitated using a white screen printing ink, solid printed on a 100 mesh screen plate, and dried and cured at 70 ° C for 5 minutes Thus, a porous layer 3 was formed, and a water discolorable laminate that changed from white to red by absorbing water was obtained.
The obtained water discolorable laminate was cut into a rectangle, and one side of the end portion in the longitudinal direction was tapered to obtain a reversible moisture indicator 1 for soil.
When the obtained reversible moisture indicator 1 for soil is inserted into the soil 8, the colored layer is in a concealed state in the dry state, and the white porous layer 3 is visually recognized on the entire surface. As the water in the soil moves upward, the porous layer 3 changes from a white opaque state to a colorless and transparent state by liquid absorption, and the red color tone of the lower colored layer 4 is visually recognized. In the liquid absorption state (the state where there is sufficient water in the soil), the color tone of the colored layer 4 is maintained while being visually recognized. However, the water is evaporated and dried from the soil, and the water absorbing material 2 is dried. Change to state. This reversible change could be repeated.

Example 2 (see FIG. 2)
Blue pigment 5 parts, acrylic ester emulsion 50 parts, aqueous ink thickener 3 parts, leveling agent 0.5 part, epoxy-based crosslinking agent on the entire surface of a 1 mm thick white cushion paper as a support (water-absorbing material 2) A solid layer was printed using a blue screen printing ink obtained by uniformly mixing and stirring 5 parts, and dried and cured at 70 ° C. for 5 minutes to provide a colored layer 4.
Next, 15 parts of wet process fine powder silica [trade name: Nipseal E-200, manufactured by Nippon Silica Industry Co., Ltd.], urethane emulsion [trade name: Hydran HW-930, Dainippon Ink & Chemicals, Inc. ( Co., Ltd., solid content 50%] 30 parts, water 50 parts, silicone antifoam 0.5 parts, aqueous ink thickener 3 parts, ethylene glycol 1 part, isocyanate crosslinking agent 3 parts uniformly mixed Using a white screen printing ink obtained by stirring, solid printing is performed on a 100-mesh screen plate, followed by drying and curing at 70 ° C. for 5 minutes to form the porous layer 3. A water-discoloring laminate that changes to γ was obtained.
The obtained water discolorable laminate was cut into a rectangle, and one side of the end portion in the longitudinal direction was tapered to obtain a reversible moisture indicator 1 for soil.
When the obtained reversible moisture indicator 1 for soil is inserted into the soil 8, the colored layer is in a concealed state in the dry state, and the white porous layer 3 is visually recognized on the entire surface. As the water in the soil moves upward, the porous layer 3 changes from a white opaque state to a colorless and transparent state by liquid absorption, and the blue color tone of the lower colored layer 4 is visually recognized. In the liquid absorption state (the state where there is sufficient water in the soil), the color tone of the colored layer 4 is maintained while being visually recognized. However, the water is evaporated and dried from the soil, and the water absorbing material 2 is dried. Change to state. This reversible change could be repeated.

Example 3 (see FIG. 3)
The white polyethylene sheet provided with the label 61 which describes a name as the base material 6 was stuck on the water-absorbing material 2 side of the reversible moisture indicator 1 for soil obtained in Example 2 via an adhesive. Furthermore, the scale which consists of the non-color-change layer 7 was provided in the vicinity of the one side edge part of the longitudinal direction of the porous layer 3 surface at equal intervals.
The obtained indicator was more practical because it was able to visually observe the same change as in Example 2 depending on the amount of moisture, and was excellent in durability and more accurately confirmed the amount of moisture.

Example 4 (see FIG. 4)
A white rayon twill fabric having a basis weight of 180 g / m ² is selected as a support (water-permeable layer 5), and the blue screen printing ink used in Example 2 is used on the entire surface of the fabric to form a 180 mesh screen plate. The blue colored layer 4 was provided by solid printing and drying and curing at 100 ° C. for 3 minutes.
Subsequently, 15 parts of wet-process fine powder silica [trade name: Nipseal E-200, manufactured by Nippon Silica Industry Co., Ltd.], urethane emulsion [trade name: Hydran HW-930, Dainippon Ink & Chemicals, Inc.] Industrial Co., Ltd., solid content 50%] 30 parts, fluorescent pink coloring pigment 0.5 part, water 50 parts, silicone-based antifoaming agent 0.5 part, aqueous ink thickener 3 parts, ethylene glycol 1 part Then, using a white screen printing ink obtained by uniformly mixing and stirring 3 parts of a blocked isocyanate-based crosslinking agent, solid printing was performed on a 100-mesh screen plate, followed by drying and curing at 130 ° C. for 5 minutes to obtain a porous layer 3 To form a water-permeable water-coloring laminate.
The obtained water-permeable water discolorable laminate is attached via an adhesive so as to cover the entire upper outer peripheral surface of the cylindrical water-absorbing material 2 made of a fiber convergence processed body, thereby reversible moisture indicator for soil. 1 was obtained.
When the obtained reversible moisture indicator 1 for soil is inserted into the soil 8, the colored layer 4 is in a concealed state in the dry state, and the light pink porous layer 3 is visually recognized on the entire surface, but the water absorbing material 2 As the water in the soil moves upwards through the soil, the porous layer 3 changes from a light pink opaque state to a light pink transparent state due to liquid absorption, and the blue colored layer 4 below appears. A purple color is visible. In the liquid absorption state (the state where there is sufficient water in the potted plant), the purple color tone is kept visible, but when the water absorbing material 2 is dried by evaporating and drying the water from the soil, the original light pink state To change. This reversible change could be repeated.

Example 5 (see FIG. 5)
As a support (water absorbing material 2), 5 parts of blue pigment, 50 parts of acrylate emulsion, and water-based ink thickening are applied to a half of the longitudinal direction of white cushion paper (thickness 1 mm) cut into a rectangle. Using a blue screen printing ink obtained by uniformly mixing and stirring 3 parts of an agent, 0.5 part of a leveling agent, and 5 parts of an epoxy crosslinking agent, solid printing was performed on a 180 mesh screen plate at 100 ° C. for 3 minutes. The colored layer 3 was provided by drying and curing.
Next, 15 parts of wet-process fine powder silica [trade name: Nipseal E-200, manufactured by Nippon Silica Industry Co., Ltd.], urethane emulsion [trade name: Hydran HW-930, Dainippon Ink & Chemicals, Inc. ( Co., Ltd., solid content 50%] 30 parts, 50 parts of water, 0.5 part of silicone-based antifoaming agent, 3 parts of thickener for water-based ink, 1 part of ethylene glycol, 3 parts of blocked isocyanate-based crosslinking agent Using a white ink obtained by mixing and stirring, a canvas-like geometric pattern is printed on a 100-mesh screen plate and dried and cured at 130 ° C. for 5 minutes to form a porous layer 2. A reversible moisture indicator 1 for soil was obtained by sticking a polypropylene plate as a base material part 5 on the back surface of the material with an adhesive.
When the obtained reversible moisture indicator 1 for soil is inserted into the soil 8, in a dry state, a canvas-like geometric pattern composed of the white porous layer 3 in which a part of the colored layer 4 is concealed is visually recognized. As the water in the soil moves upward through the water absorbing material 2, the porous layer 3 changes from a white opaque state to a colorless and transparent state due to liquid absorption, and the entire surface of the lower blue colored layer 4 appears. As a result, a blue color tone is visually recognized. In the liquid absorption state (the state where there is sufficient water in the potted plant), the blue color tone is kept visible, but when the water-absorbing material 2 is dried by evaporating and drying the water from the soil, the original canvas-like pattern is obtained. And change. This reversible change could be repeated.

It is a longitudinal cross-sectional view of one Example of the reversible moisture indicator for soil of the present invention. It is a longitudinal cross-sectional view of one Example of the reversible moisture indicator for soil of the present invention. It is a surface view of one Example of the reversible moisture indicator for soil of the present invention. It is a longitudinal cross-sectional view of one Example of the reversible moisture indicator for soil of the present invention. It is a longitudinal cross-sectional view of one Example of the reversible moisture indicator for soil of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water | moisture-content indicator for pot plants 2 Water absorption material 3 Porous layer 4 Colored layer 5 Water-permeable layer 6 Base material 61 Label (display part)
7 Scale (non-discoloring layer)
8 soil

Claims (5)

  A reversible moisture indicator for soil, comprising at least a part of a water-absorbing material inserted into the soil and a porous layer laminated at a position in contact with the water-absorbing material, wherein the porous layer has a low refractive index. A reversible moisture indicator for soil, characterized in that transparency is different between a liquid-absorbing state in which a pigment is fixed in a binder resin in a dispersed state and a non-liquid-absorbing state.   A reversible moisture indicator for soil, comprising a water-absorbing material inserted at least in part into soil, a water-permeable layer laminated at a position in contact with the water-absorbing material, and a porous layer laminated on the water-permeable layer. Wherein the porous layer has a structure in which transparency is different between 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. indicator.   The reversible moisture indicator for soil according to claim 2, wherein the water permeable layer is selected from any of porous paper, fabric, and porous film.   The reversible moisture indicator for soil according to any one of claims 1 to 3, wherein a colored layer is provided below the porous layer.   The reversible moisture indicator for soil according to any one of claims 1 to 4, wherein the porous layer is provided on an upper portion or a middle portion of a water absorbing material inserted into the soil from below.

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