JP7784355B2 - Indicator-equipped items - Google Patents

Description

An embodiment of the present invention relates to an article with an indicator.

Some humidity sensors use an electrolyte polymer composition as a humidity-sensitive membrane. This humidity sensor detects humidity by taking advantage of the change in electrical resistance of the humidity-sensitive membrane as it absorbs moisture.

Special Publication No. 2007-502342

The problem that this invention aims to solve is to provide technology that makes it possible to check solvent content using a simple configuration.

According to one embodiment, an article with an indicator is provided, comprising a support, an adhesive layer supported on the support, and an indicator that displays the degree of drying of the adhesive layer in a wet state, the indicator being adjacent to the adhesive layer and including a color former and a color developer.

FIG. 1 is a cross-sectional view showing an article with an indicator according to an embodiment. FIG. 2 is a diagram showing the state in which the release sheet has been removed from the product with the indicator shown in FIG. 1 and the adhesive layer has been wetted. FIG. 3 is a diagram showing a state where drying has progressed from the state shown in FIG. FIG. 4 is a diagram showing the state in which the release sheet has been removed from the modified product with an indicator and the adhesive layer has been wetted. FIG. 5 is a diagram showing a state where drying has progressed from the state shown in FIG. FIG. 6 is a cross-sectional view showing a label according to a reference example. FIG. 7 is a cross-sectional view showing a containerized product according to a reference example. FIG. 8 is a graph showing an example of the relationship between humidity and image density.

The following describes the embodiment with reference to the drawings.

<1> Article with indicator Fig. 1 is a cross-sectional view showing an article with an indicator according to an embodiment. Fig. 2 is a diagram showing a state in which the release sheet has been removed from the article with an indicator shown in Fig. 1 and the adhesive layer has been moistened. Fig. 3 is a diagram showing a state in which drying has progressed from the state shown in Fig. 2.

The indicator-equipped article 1 shown in Figure 1 includes an article body 10 and a release sheet 20.

<1.1> Article Body The article body 10 includes a support 110, an adhesive layer 120, an indicator 130, and a print layer 140 shown in FIGS. 2 and 3.

<1.1.1> Support The support 110 is an article to be attached to an article other than the article with the indicator (hereinafter referred to as the other article). The support 110 is, for example, a film or sheet. In this case, the support 110 may include a base layer such as paper or a polymer film. Such a support 110 may have a single-layer structure or a multi-layer structure. If the support 110 has a multi-layer structure, it may further include one or more other layers such as a printing layer and a protective layer. In one example, the support 110 is wallpaper.

<1.1.2> Adhesive Layer The adhesive layer 120 is supported by the support 110. Here, the support 110 is a film or a sheet, and the adhesive layer 120 is supported by one of the main surfaces of the support 110.

The adhesive layer 120 is a layer made of an adhesive. In one example, the adhesive contains a solvent. In another example, the adhesive is solvent-free or has a low solvent content, and has low adhesive strength when not in use, but whose adhesive strength increases when a solvent is applied when attaching the support 110 to another article.

The solvent evaporates as the adhesive layer 120 dries. The solvent may be water, an organic solvent, or a mixture thereof. In one example, the solvent is an aqueous solvent. The aqueous solvent may be water, alcohol, or a mixture of water and alcohol. The solvent may also be a hydrophobic organic solvent.

<1.1.3> Indicator The color of the indicator 130 can be confirmed when the article main body 10 is observed from the adhesive layer 120 side. The indicator 130 indicates the progress of drying of the adhesive layer 120 in a wet state, i.e., the adhesive layer 120 containing a solvent. The color of the indicator 130 changes as the drying of the adhesive layer 120 progresses. For example, the color of the indicator 130 becomes darker as the drying of the adhesive layer 120 progresses.

The indicator 130 is adjacent to the adhesive layer 120. That is, the indicator 130 is in contact with the adhesive layer 120. Placing the indicator 130 adjacent to the adhesive layer 120 increases the correlation between the solvent concentration in the adhesive layer 120 and the solvent concentration in the indicator 130 compared to when another layer is interposed between them. Therefore, placing the indicator 130 adjacent to the adhesive layer 120 increases the correlation between the solvent concentration in the adhesive layer 120 and the color of the indicator 130 compared to when another layer is interposed between them.

Here, the indicator 130 is interposed between the support 110 and the adhesive layer 120. The indicator 130 may also be interposed between the adhesive layer 120 and the release sheet 20. Alternatively, the indicator 130 may be embedded within the adhesive layer 120.

The indicator 130 is made of a coloring material containing a coloring agent and a color developer. Any combination of coloring agent and color developer may be used as long as it produces the color change described above. Examples of coloring agents and color developers are listed below.

(1) Color Developer The color developer causes the coloring agent to develop color. The color developer is, for example, porous particles made of inorganic oxide.

The inorganic oxide may be a non-metal oxide such as silica, a metal oxide such as titania or alumina, or a combination thereof.

The porous particles are preferably made of an electron-accepting material. According to one example, when a colorant is bound to the surface of a porous particle, the colorant donates electrons to the porous particle, causing the colorant to develop color.

The porous particles are preferably silica, and more preferably activated silica. Here, "activated silica" refers to silica with a large surface area and high reactivity due to the hydroxyl groups (silanol groups) on the silica surface.

Activated silica has excellent thermal stability and is readily available in small particle form. Therefore, using activated silica as porous particles allows for the color-producing particles to be made smaller. Therefore, using activated silica as porous particles is advantageous for displaying high-resolution images on the indicator 130. Furthermore, such color developers have a high affinity for hydrophilic substances. Therefore, for example, when the above-mentioned solvent is an aqueous solvent, using activated silica as porous particles can amplify the color change of the indicator 130 as the adhesive layer 120 dries.

Specific examples of activated silica include VP SG40 (40 m ² /g) and AEROSIL (registered trademark) OX50 (50 m ² /g), 50 (50 m ² /g), 90G (90 m ² /g), 130 (130 m ² /g), 200 (200 m ² /g), 300 (300 m ² /g), and 380S (380 m ² /g) manufactured by Nippon Aerosil Co., Ltd.; and Reolosil (registered trademark) QS-10 (140 m ² /g), QS-20 (220 m ² /g), QS-30 (300 m ² /g), and QS-40 (380 m ² /g) manufactured by Tokuyama Corporation. /g), Sunsil (registered trademark) series, and Silfil (registered trademark) series; CAB-O-SIL (registered trademark) fumed silica HS-5, MS-5, and MS-7 manufactured by Cabot Corporation; Nipsil (registered trademark) series and NIPGEL (registered trademark) series such as Nipsil (registered trademark) LP manufactured by Tosoh Silica Corporation; Sunsphere (registered trademark) H-31 (800m ² /g), H-51 (800m 2 /g), H-121 (800m ² /g), H-201 (800m ² /g), H-32 (700m ² /g), H-52 (700m ² /g), H-122 (700m ^{2 /g), H-33 (700m 2 /} g), H-53 (700m ² /g) manufactured by AGC Si-Tech Co., ^Ltd. /g), L-31 (300m ² /g), and L-51 (300m ² /g); SB-300 (300m ² /g), SB-700 (700m ² /g), and SB-705 (600m ² /g) manufactured by Miyoshi Chemicals Co., Ltd.; and Sylysia (registered trademark) 250 (280m ² /g), 310P (300m ² /g), 320 (300m ² /g), 420 (350m ² /g), 530 (500m ² /g), and 710 (700m ² /g) manufactured by Fuji Silysia Chemical Ltd. The numbers in parentheses represent the BET specific surface area described below.

The porous particles preferably have a specific surface area measured by the Brunauer, Emmett and Teller (BET) method, i.e., a BET specific surface area, of 50 ^m /g or more, more preferably in the range of 200 to 750 ^m /g. Increasing the BET specific surface area deepens the color of the indicator 130 in a completely dried state. However, if the BET specific surface area is excessively large, the color of the indicator 130 may also deepen when the solvent content is excessive.

Porous particles may or may not be secondary particles formed by agglomeration of primary particles. Preferably, porous particles are secondary particles with a three-dimensional structure formed by agglomeration of primary particles with an average particle diameter of 10 nm or less. Here, the "average particle diameter" of the primary particles is a value obtained by image analysis using an electron microscope.

The porous particles preferably have an average particle size in the range of 40 nm to 10 μm, and more preferably in the range of 50 nm to 5 μm. Here, the "average particle size" of the porous particles is a value obtained by laser diffraction scattering. If the average particle size is large, it may not be possible to obtain a large specific surface area. If the average particle size is too small, strong aggregation may occur.

(2) Coloring Agent When the indicator 130 is completely dry, the coloring agent is supported by the porous particles. According to one example, the coloring agent is adsorbed by the porous particles. The coloring agent develops color due to the action of the porous particles.

The color former is, for example, an electron-donating color-forming compound. Examples of color-forming compounds that can be used include leuco dyes, specifically electron-donating organic compounds such as leucoauramines, rhodamine B lactams, indolines, spiropyrans, and fluorans. Other examples of such color-forming compounds include diphenylmethane phthalides, phenylindolyl phthalides, indolyl phthalides, diphenylmethane azaphthalides, phenylindolyl azaphthalides, fluorans, styrinoquinolines, and diazarhodamine lactones. Other examples of such color-forming compounds include pyridine-based, quinazoline-based, and bisquinazoline-based compounds.

Specific examples of color-forming compounds include 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (crystal violet lactone; CVL), malachite green lactone, 2-anilino-6-(N-cyclohexyl-N-methylamino)-3-methylfluoran, 2-anilino-3-methyl-6-(N-methyl-N-propylamino)fluoran, 3-[4-(4-phenylaminophenyl)aminophenyl]amino-6-methyl-7-chlorofluoran, 2-anilino-6-(N-methyl-N-isobutylamino)-3-methylfluoran, 2-anilino-6-(dibutylamino)-3-methylfluoran, 3-chloro-6-(cyclohexylamino)fluoran, 2-chloro-6-(diethylamino)fluoran, 7-(N,N-dibenzylamino)-3-(N,N-diethylamino)fluoran, 3,6-bis(diethylamino)fluoran-γ-(4'-nitro)anilinolactam, 3-diethylaminobenzo[a]-fluoran, 3-diethylamino-6-methyl-7-aminofluoran, 3-diethylamino-7-xylidinofluoran, 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide, 3-diethylamino-7-chloroanilinofluoran, 3-di Ethylamino-7,8-benzofluoran, 3,3-Bis(1-n-butyl-2-methylindol-3-yl)phthalide, 3,6-dimethylethoxyfluoran, 3-diethylamino-6-methoxy-7-aminofluoran, DEPM, ATP, ETAC, 2-(2-chloroanilino)-6-dibutylaminofluoran, crystal violet carbinol, malachite green carbinol, N-(2,3-dichlorophenyl)leucoauramine, N-benzoylauramine, rhodamine B lactam, N-acetylauramine, N-phenylauramine, 2-(phenyliminoethanedylidene)-3,3-dimethylindoline, N-3,3-trimethylindolinobenzospiropy fluoran, 8'-methoxy-N-3,3-trimethylindolinobenzospiropyran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-diethylamino-7-methoxyfluoran, 3-diethylamino-6-benzyloxyfluoran, 1,2-benz-6-diethylaminofluoran, 3,6-di-p-toluidino-4,5-dimethylfluoran-phenylhydrazide-γ-lactam, 3-amino-5-methylfluoran, 3,6-diphenylaminofluoran, 3,6-dimethoxyfluoran, 3,6-di-n-butoxyfluoran, 2-methyl-6-(N-ethyl-N-p-tolylamino)fluoran, 2-N,N-dibenzylamino-6-diethylaminofluoran, 3-chloro-6-cyclohexylaminofluoran, 2-methyl-6-cyclohexylaminofluoran, 2-(2-chloroanilino)-6-di-n-butylaminofluoran, 2-(3-trifluoromethylanilino)-6-diethylaminofluoran, 2-(N-methylanilino)-6-(N-ethyl-N-p-tolylamino)fluoran, 1,3-dimethyl-6-diethylaminofluoran, 2-chloro-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-di-n-butylaminofluoran, 2-xylidino-3-methyl-6-diethylaminofluoran, 1,2-benz-6-diethylaminofluoran Fluoran, 1,2-benz-6-(N-ethyl-N-isobutylamino)fluoran, 1,2-benz-6-(N-ethyl-N-isoamylamino)fluoran, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-[2-ethoxy-4-(N-ethylanilino)phenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 2-(3-methoxy-4-dodecoxystyryl)quinolinespiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5,1'(3'H)isobenzofuran] benzopyrano(2,3-d)pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(di-n-butylamino)-4-methylspiro[5H-(1)benzopyrano(2,3-d)pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(diethylamino)-4-methylspiro[5H-(1)benzopyrano(2,3-d)pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(diethylamino)-4-methylspiro[5H-(1)benzopyrano(2,3-d)pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(N-ethyl-N-i-amylamino)-4-methylspiro[5H-(1)benzopyrano(2,3-d)pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, Examples include pyro[5H-(1)benzopyrano(2,3-d)pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(di-n-butylamino)-4-phenyl-3-(2-methoxy-4-dimethylaminophenyl)-3-(1-butyl-2-methylindol-3-yl)-4,5,6,7-tetrachlorophthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4,5,6,7-tetrachlorophthalide, and 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-pentyl-2-methylindol-3-yl)-4,5,6,7-tetrachlorophthalide.

Commercially available color-developing compounds include RED500, RED520, CVL, S-205, BLACK305, BLACK400, ETAC, NIR BLACK78, BLUE220, H-3035, BLUE203, GREEN300, ATP, H-1046, and H-2114 manufactured by Yamada Chemical Co., Ltd., and ODB-4, Blue-63, Blue-502, GN-169, GN-2, Green-118, Red-40, and Red-8 manufactured by Yamamoto Chemicals Co., Ltd.

These can be used alone or in combination of two or more. By appropriately selecting the color-forming compound, a variety of color-developing states can be obtained, making it possible to express multiple colors.

The amount of colorant is preferably in the range of 5 to 50 parts by mass, and more preferably in the range of 10 to 40 parts by mass, per 100 parts by mass of porous particles. Increasing the amount of colorant will result in a darker color for the indicator 130 when completely dried. However, if too much colorant is used, the color of the indicator 130 may also darken when the solvent content is excessive.

(3) Other Components The indicator 130 preferably does not contain any compounds that can function as a decolorizer, except for the solvent. The decolorizer has the property of decolorizing the colorant when heated to a predetermined temperature or higher. Examples of decolorizers include those having an ester group, a ketone group, a hydroxyl group, an ether group, or an amide group. Examples of decolorizers include polyhydric alcohols, nonionic surfactants, cationic surfactants, and hindered amine derivatives.

The indicator 130 is preferably salt-free. That is, the indicator 130 preferably does not contain any salt, except for any salt that may be unavoidably contained. Here, the indicator 130 being salt-free means that the proportion of salt in the indicator 130 is 100 ppm or less (by mass).

The indicator 130 can be formed using ink containing the above-mentioned colorant and dispersion medium. This ink can further contain the other components mentioned above. Various printing methods can be used to form the indicator 130 using this ink, such as inkjet printing, screen printing, offset printing, and flexographic printing.

The indicator 130 and the ink used to form it may further include other ingredients such as humectants, moisture absorption inhibitors, and viscosity adjusters. For example, the ink may further include glycerin.

The indicator 130 and the ink used to form it may further contain an anionic surfactant. Examples of anionic surfactants include alkylbenzene sulfonates, sulfosuccinate ester salts, higher alcohol phosphate ester salts, higher alcohol sulfate ester salts, and amino acid surfactants. Specific examples include sodium dodecylbenzenesulfonate and sodium dioctyl sulfosuccinate.

These additives may, for example, enable or stabilize the ejection of ink from an inkjet head.

<1.1.4> Printed Layer The printed layer 140 is provided near the indicator 130. Here, the printed layer 140 is provided between the support 110 and the adhesive layer 120 so as to be adjacent to the indicator 130. The printed layer 140 can be formed by various printing methods similar to those described above for the indicator 130.

Unlike the indicator 130, the printed layer 140 does not undergo color change. The printed layer 140 includes a color sample section. In this example, the color sample section includes multiple colored sections and a printed section. The printed section can be omitted.

The colored portions are different in color. In one example, the colored portions are different in color intensity. Each of the colored portions preferably corresponds to the color that the indicator 130 exhibits when the adhesive layer 120 contains a certain concentration of solvent. In Figures 2 and 3, the color of the colored portions increases in color from the right end to the left end.

The printed portion includes multiple printed patterns that serve as indicators of the degree of drying. These printed patterns are arranged to correspond to the colored portions. Here, these printed patterns display the letters "A," "B," "C," "D," "E," and "F." As an example, the degree of drying increases in the order of indicators A, B, C, D, E, and F, with indicators A through C indicating that the adhesive layer 120 contains too much solvent, indicators E and F indicating that the adhesive layer 120 contains too little solvent, and indicator D indicating that the solvent content of the adhesive layer 120 is within an appropriate range.

<1.2> Release Sheet The release sheet 20 is removably attached to the adhesive layer 120. When the indicator-equipped article 1 is not in use, for example, when the indicator-equipped article 1 is stored or transported when not in use, the release sheet 20 prevents the surface of the adhesive layer 120 from coming into contact with the surface of the support 110 or other articles. Furthermore, if the adhesive layer 120 contains a solvent, the release sheet 20 makes it difficult for the adhesive layer 120 to dry out when the indicator-equipped article 1 is not in use. The release sheet 20 can be omitted.

<1.3> Effects As described above, when using the indicator-equipped article 1, the release sheet 20 is peeled off from the adhesive layer 120, and the support 110 is attached to another article via the adhesive layer 120. The adhesive layer 120 exhibits high adhesive strength when attaching the support 110 to another article, provided that the solvent content is within an appropriate range. If the solvent content of the adhesive layer 120 is too low or too high during this attachment, sufficient adhesive strength may not be obtained.

The article body 10 includes an indicator 130 and a printed layer 140. The printed layer 140 includes a color sample section.

The user can visually compare the color of the indicator 130 with the color of the colored portion of the color sample board and select the colored portion that is closest in color to the indicator 130. The user can then determine that the period during which the indicator corresponding to the selected colored portion is indicator D is the optimal period for attaching the support 110 to another item.

Furthermore, if the indicator 130 and the printing layer 140 can be observed through the support 110, the progress of drying of the adhesive layer 120 can be confirmed using the same method as above after the support 110 is attached to another article. For example, when installing wallpaper, the wallpaper is attached to a wall, and the next step is performed after the adhesive layer has sufficiently dried. Conventionally, the determination of whether the adhesive layer has sufficiently dried was left to the experience of the installer. By using the above method using the indicator 130, etc., even if the installer is inexperienced or inexperienced, the next step can be performed after the adhesive layer has sufficiently dried.

In this way, the configuration described above for indicator-equipped article 1 allows the user to check the solvent content, for example, the water content, without using electrical circuits, etc. In other words, the configuration described above for indicator-equipped article 1 is simple yet allows the user to check the solvent content.

<2> Modifications The indicator-equipped article 1 can be modified in various ways.
For example, the article main body 10 may not include the printed layer 140. If a color sample similar to the color sample book described above is prepared separately from the article main body 10, the user can check the solvent content in the same manner as described above.

The solvent content can be determined without the use of a color swatch.
Fig. 4 is a diagram showing a state in which the release sheet has been removed from the article with an indicator according to the modified example and the adhesive layer has been moistened, and Fig. 5 is a diagram showing a state in which drying has progressed from the state shown in Fig. 4 .

The indicator-equipped item of this modified example is similar to the indicator-equipped item 1 described above, except that it includes an item main body 11 instead of the item main body 10. The item main body 11 is similar to the indicator-equipped item 10 described above, except that it has the following configuration.

That is, in the article body 11, the printing layer 140 is interposed between the support 110 and the indicator 130. The printing layer 140 does not include a color sample unit.

In this article body 11, if the adhesive layer 120 contains an excessive amount of solvent, the indicator 130 exhibits high transmittance for visible light, allowing the printed layer 140 to be seen through, as shown in Figure 4.

As the solvent content of the adhesive layer 120 decreases, the transmittance of the indicator 130 to visible light decreases, and the printed layer 140 becomes invisible, as shown in Figure 5. Therefore, for example, if the user is instructed to attach the support 110 to another item a predetermined time after the printed layer 140 becomes invisible, the user can attach the support 110 to another item within the optimal period of time.

<3> Reference Example In the Reference Example, the object for which the indicator should indicate the degree of drying is not limited to an adhesive layer. The color material according to the Reference Example is a color material used in an indicator that indicates the degree of drying of a wet substance, and includes a coloring agent and porous particles made of an inorganic oxide as a color developer. The ink according to the Reference Example is an ink used in an indicator that indicates the degree of drying of a wet substance, and includes the above-mentioned color material.

The colorants described above can be used, for example, in labels and packaged articles.
An example of such a label comprises a support and an indicator that displays the progress of drying of a wet substance, the indicator being supported on the support and containing the color material described above.

An example of a containerized item includes a container, a wet substance contained in the container, and an indicator that displays the progress of drying of the wet substance, the indicator being provided inside the container and containing the color material described above.

FIG. 6 is a cross-sectional view showing a label according to a reference example.
The label 2 shown in FIG. 6 includes a label body 13 and a release sheet 20 .

The label body 13 includes a support 110, an adhesive layer 120, an indicator 130, and a printing layer (not shown).

The support 110 is, for example, a film or sheet. The support 110 may include a substrate layer such as paper or a polymer film. The support 110 may have a single-layer structure or a multi-layer structure.

The adhesive layer 120 is supported by one of the main surfaces of the support 110. The adhesive layer 120 is made of, for example, the adhesive described above for the adhesive layer 120 of the indicator-equipped article 1. The adhesive layer 120 may be made of a solvent-free adhesive or a pressure-sensitive adhesive.

The indicator 130 is supported by the other main surface of the support 110. The indicator 130 is as described above for the indicator 130 of the indicator-equipped item 1.

According to one example, the printing layer is supported by the other major surface of the support 110. In this case, the printing layer may include the color sample unit described above for the printing layer 140 with reference to Figures 2 and 3.

In another example, the printing layer is provided between the support 110 and the indicator 130. For example, the printing layer may be covered by the indicator 130, such as the printing layer 140 described with reference to Figure 4.

In yet another example, the printing layer is arranged to face the support 110 with the indicator 130 sandwiched between them. This arrangement is also possible in applications where the label body 13 is intended to be observed from the adhesive layer 120 side.

The release sheet 20 is removably attached to the adhesive layer 120. The release sheet 20 is as described above for the release sheet 20 of the indicator-equipped article 1.

Label 2 can be used, for example, in the production of containerized goods. An example of a containerized goods that can be produced using label 2 is described below.

FIG. 7 is a cross-sectional view showing a containerized product according to a reference example.
The containerized product 3 shown in FIG. 7 includes a container 30 , contents 31 , and a label body 13 .

The container 30 is a sealed container. At least a portion of the container 30 is transparent. This transparent portion allows the user to observe the label body 13 in an unopened state.

Here, the container 30 includes a container body 310 and a lid 320. The container body 310 is cylindrical with a bottom and has a flange at the opening. The lid 320 is heat-sealed to the flange of the container body 310, closing the opening of the container body 310. The container 30 may also be in other forms, such as a bag.

Contents 31 are contained within container 30. Contents 31 are a wet substance. In one example, contents 31 are a food product containing water. The food product containing water may be, for example, fresh food, processed food, cooked food, or confectionery.

The label body 13 is placed inside the container 30. Here, the label body 13 is attached to the inner surface of the lid body 320. If the contents 31 are food, it is preferable that the coloring material contained in the label body 13 or the ink used to form the indicator 130 is edible.

As described above, the label body 13 includes an indicator 130 that displays the degree of drying of a wet substance. The color of the indicator 130 changes depending on the humidity inside the container 30. Therefore, the indicator 130 can display the degree of drying of the contents 31.

The containerized item 3 may not include the label body 13. In this case, the indicator 130 and the printed layer 140 are provided on the inner surface of the container 30. The printed layer 140 may be omitted.

Examples are described below.

Five parts by weight of colorant, 50 parts by weight of developer, and 800 parts by weight of acetone were placed in a pear-shaped flask and the mixture was stirred. Crystal Violet Lactone (Yamada Chemical Co., Ltd.) was used as the colorant. AEROSIL® 300 (Nippon Aerosil Co., Ltd.), a silica particle, was used as the developer. Next, a rotary evaporator was used to remove the acetone from the mixture to obtain a colored material. This colored material was then pulverized in a mixer to obtain colored particles as a color material.

Next, a dispersion containing these color-forming particles and water was prepared. An indicator was formed on a medium by printing using this dispersion as ink. This was placed in an enclosed space, and the humidity within the space was changed to measure the density of the image displayed by the indicator. The results are shown in Figure 8.

Figure 8 is a graph showing an example of the relationship between humidity and image density. As shown in Figure 8, as humidity decreased, image density increased. Here, humidity and image density had a linear relationship. Furthermore, the change in image density in response to changes in humidity was reversible.

The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the various embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the multiple elements disclosed. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

1...Item with indicator, 2...Label, 3...Item in container, 10...Item body, 11...Item body, 13...Label body, 20...Release sheet, 30...Container, 31...Contents, 110...Support, 120...Adhesive layer, 130...Indicator, 140...Printed layer, 310...Container body, 320...Lid.

Claims (5)

A support;
an adhesive layer supported on the support;
An indicator-equipped article comprising an indicator that displays the degree of drying of the adhesive layer in a wet state, the indicator being adjacent to the adhesive layer and containing a coloring agent and a color developer. The article with an indicator according to claim 1, further comprising a release sheet covering the adhesive layer. The article with an indicator according to claim 1, wherein the developer is porous particles made of an inorganic oxide. The article with an indicator according to claim 1, wherein the indicator is salt-free. 2. The article with an indicator according to claim 1, wherein the support is wallpaper.