Writing way learning tool

Abstract

To provide a repeatedly usable writing way learning tool which enables even a preschooler who is not accustomed to handling a writing instrument or the like to efficiently learn with a real feeling of writing and enables a third person to visually determine whether or not a user can correctly trace and learn a model because a color of the model changes or a size or shape of the model changes when the model such as a character is traced with a fingertip.SOLUTION: A writing way learning sheet in which a model selected from the group consisting of characters, numbers, and symbols is provided on a base material, wherein the model contains a reversible thermochromic material and reversibly changes in color from a colored state to a different colored state, and the reversible thermochromic material has a complete decoloring temperature t4 of 26 to 37°C and exhibits a hysteresis width (ΔH) of 5°C or less with respect to a color density-temperature curve.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a writing training tool. [Background technology]

[0002] Conventionally, teaching tools for children to learn letters such as hiragana, katakana, and the alphabet include cards, blocks, panels, etc. on which letters are printed on a base material made of paper or resin, allowing children to become familiar with and learn letters through play. Some of these teaching tools have a picture related to a specific letter and the name (word) of that picture placed near the specific letter, and the combination of the letter with the picture or the name of the picture has the effect of encouraging learning of the letter.

[0003] Also disclosed are writing practice sheets in which writing grooves in the shape of letter patterns that can be traced with a writing implement are formed on a resin sheet, and hard-tip calligraphy cards for learning characters, in which letters such as hiragana, katakana, kanji, and alphabets are printed or molded into thick paper or plastic with varying depths of depressions (see, for example, Patent Documents 1 and 2). These allow children to learn how to write characters by tracing the grooves of the letters with a writing implement, but it can be difficult for preschool children (young children) who are not accustomed to using writing implements to practice writing characters using such sheets or cards, and furthermore, when used with a pencil or the like, the sheets or cards become noticeably dirty with repeated use, requiring a lot of effort to clean. Another example is a letter board that combines a picture of a familiar object with the first kana character of its name and a carved indentation representing the letter, all on the surface of a single board, allowing the user to memorize the letter by tracing the indentations (see, for example, Patent Document 3). This letter board allows a child to memorize the letter by tracing the indentations carved into the letter shape with their finger, utilizing the synergistic effect of vision and touch. However, preschool children (toddlers) who are unable to control their strength may apply too much force when tracing the indentations, potentially leaving marks on their fingers or causing injury. Furthermore, it is difficult for third parties to see whether the user is tracing along the indentations, making it difficult to determine whether the user is learning the letters correctly. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Microfilm of Utility Model Application No. 62-113426 (Utility Model Application No. 1-19981) [Patent Document 2] Japanese Utility Model Application Publication No. 6-40971 [Patent Document 3] Japanese Utility Model Application Publication No. 6-40970 Summary of the Invention [Problem to be solved by the invention]

[0005] To provide a reusable writing learning tool which changes the color or size or shape of a model character or the like when the model character is traced with a fingertip, allowing a user to learn efficiently with a sense of actual writing, and also allowing a third party to visually judge whether the user is tracing the model correctly. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides the following aspects. [1] A writing learning tool having a base material on which a model selected from the group consisting of letters, numbers, and symbols is provided, The sample comprises a reversible thermochromic material, and reversibly changes color from one color to another color, and the reversible thermochromic material is a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that controls the color reaction of the components (a) and (b), or a reversible thermochromic resin particle in which the reversible thermochromic composition is dispersed in a thermoplastic resin or a thermosetting resin, and exhibits hysteresis characteristics in the color density-temperature curve. A writing learning tool that exhibits alternating changes between a colored state and a colorless state, and in the process of increasing temperature from the colored state, it begins to fade when it reaches a color-fading starting temperature t3 and becomes completely colorless in the temperature range above the complete color-fading temperature t4, which is higher than the temperature t3, and in the process of decreasing temperature from the colorless state, it begins to color when it reaches a color-fading starting temperature t2 and becomes completely colored in the temperature range below the complete color-fading temperature t1, which is lower than the temperature t2, and exhibits hysteresis characteristics, with the complete color-fading temperature t4 being 26 to 37°C and a hysteresis width (ΔH) of 5°C or less on the color density-temperature curve. [2] A writing learning tool having a base material on which a model selected from the group consisting of letters, numbers, and symbols is provided, The sample is composed of a non-thermochromic image and a reversible thermochromic image, and is the letter, number, or symbol whose size or shape at least changes with a temperature change and remains the same before and after the temperature change; The reversible thermochromic image comprises a reversible thermochromic material, and undergoes a reversible color change from colored to colorless. The reversible thermochromic material is a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling the color reaction of the components (a) and (b), or a reversible thermochromic resin particle in which the reversible thermochromic composition is dispersed in a thermoplastic resin or a thermosetting resin, and exhibits hysteresis characteristics in the color density-temperature curve. A writing learning tool that exhibits alternating changes between a colored state and a colorless state, and in the process of increasing temperature from the colored state, it begins to fade when it reaches a color-fading starting temperature t3 and becomes completely colorless in the temperature range above the complete color-fading temperature t4, which is higher than the temperature t3, and in the process of decreasing temperature from the colorless state, it begins to color when it reaches a color-fading starting temperature t2 and becomes completely colored in the temperature range below the complete color-fading temperature t1, which is lower than the temperature t2, and exhibits hysteresis characteristics, with the complete color-fading temperature t4 being 26 to 37°C and a hysteresis width (ΔH) of 5°C or less on the color density-temperature curve. [3] The writing learning tool according to [1] or [2] above, wherein at least one of the following indication images is provided inside or near the model: a number corresponding to the stroke order of the letter, number, or symbol; an arrow indicating the stroke direction; or stroke collection information. [4] The writing learning tool according to any one of [1] to [3] above, further comprising a related image related to the model, selected from the group consisting of letters, numbers, symbols, figures, and pictures. [5] The writing learning tool according to any one of [1] to [4] above, wherein the reversible thermochromic material exhibits a hysteresis width (ΔH) of 3°C or less in terms of a color density-temperature curve. [6] The writing learning tool according to any one of [1] to [5] above, which is made using two or more of the reversible thermochromic materials. [7] The writing learning tool according to any one of [1] to [6] above, wherein the decolorization starting temperature t3 is 25°C or lower. [8] The writing learning tools [1] to [7] above are in sheet form. [9] A booklet-type writing learning tool that uses the writing learning tools described above in [1] to [8].

[10] The above-mentioned [9] writing learning tool is a picture book. [Effects of the Invention]

[0007] To provide a reusable writing learning tool which changes the color or size or shape of a model character or the like when the model character is traced with a fingertip, allowing even a preschool child who is not accustomed to handling writing implements to learn efficiently with a sense of actual writing, and also allows a third party to visually determine whether the user is correctly tracing the model and learning. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a graph illustrating the hysteresis characteristics in the color density-temperature curve of a reversible thermochromic composition. [Figure 2] 1 is an example of a writing learning tool according to the present invention. [Figure 3] This is a diagram showing the discoloration of a part of the example in Figure 2. [Figure 4] 3 is a cross-sectional view taken along line XX in FIG. 2. [Figure 5] 10 is another example of a writing learning tool according to the present invention. [Figure 6] FIG. 6 is a cross-sectional view taken along the line XX in FIG. 5. [Figure 7] 10 is another example of a writing learning tool according to the present invention. [Figure 8] 8 is a cross-sectional view taken along line XX in FIG. 7. [Figure 9] 10 is another example of a writing learning tool according to the present invention. [Figure 10] 10 is a cross-sectional view taken along line XX in FIG. 9. [Figure 11] 10 is another example of a writing learning tool according to the present invention. [Figure 12] 10 is another example of a writing learning tool according to the present invention. [Figure 13] 13 is a cross-sectional view taken along the line XX in FIG. 12. [Figure 14] 10 is another example of a writing learning tool according to the present invention. [Figure 15] 10 is another example of a writing learning tool according to the present invention. [Figure 16] 16 is a cross-sectional view taken along line XX in FIG. 15. [Figure 17] 10 is another example of a writing learning tool according to the present invention. [Figure 18] 10 is another example of a writing learning tool according to the present invention. [Figure 19] 10 is another example of a writing learning tool according to the present invention. [Figure 20] 10 is another example of a writing learning tool according to the present invention. [Figure 21] 10 is another example of a writing learning tool according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The model provided on the substrate of the writing learning tool (hereinafter sometimes referred to as "learning tool") according to the present invention comprises a reversible thermochromic material. Examples of reversible thermochromic materials include reversible thermochromic microcapsule pigments in which a reversible thermochromic composition containing at least the three essential components of (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color reaction of components (a) and (b) occurs is encapsulated in a microcapsule, and reversible thermochromic resin particles in which the above-mentioned reversible thermochromic composition is dispersed in a thermoplastic resin or a thermosetting resin.

[0010] The reversible thermochromic composition used in the reversible thermochromic material can be a heat-discolorable reversible thermochromic composition with a hysteresis width (ΔH) of 5°C or less, as described in Japanese Patent Publication Nos. 51-44706 and 51-44707. This reversible thermochromic composition changes color around a specific temperature (discoloration point), exhibiting a discolored state in a temperature range above the high-side discoloration point and a colored state in a temperature range below the low-side discoloration point; only one of these two states exists at room temperature; the other state is maintained as long as the heat or cold required to manifest that state is applied, but returns to the state it exhibits at room temperature when the application of heat or cold is removed. The term "thermal decolorization type" means that the color disappears when heated and the color develops when cooled.

[0011] The hysteresis characteristics of the color density-temperature curve of the reversible thermochromic composition will now be described. In Figure 1, the vertical axis represents color density and the horizontal axis represents temperature. Changes in color density due to temperature changes progress along the arrows. Here, A represents the density at temperature t4 (hereinafter referred to as the complete decolorization temperature) at which the material reaches a completely decolorized state, B represents the density at temperature t3 (hereinafter referred to as the decolorization onset temperature) at which decolorization begins, C represents the density at temperature t2 (hereinafter referred to as the color development onset temperature), and D represents the density at temperature t1 (hereinafter referred to as the complete color development temperature) at which the material reaches a completely colored state. The discoloration temperature range is the temperature range between the complete color development temperature t1 and the complete decolorization temperature t4, and the material can exhibit either a colored state or a decolorized state. The temperature range between the color development start temperature t2 and the decolorization start temperature t3, which is the region where the difference in color density is large, is essentially the two-phase maintenance temperature range. The length of the line segment EF is a measure of the contrast of the discoloration, and the length of the line segment HG passing through the midpoint of the line segment EF is the temperature range indicating the degree of hysteresis. This temperature range is the hysteresis width (ΔH). If the ΔH value is small, only one specific state can exist between the two states before and after the discoloration in the room temperature range. Furthermore, if the ΔH value is large, it is easier to maintain both the states before and after the discoloration. In the present invention, the reversible thermochromic material is a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition, or a reversible thermochromic resin particle in which a reversible thermochromic composition is dispersed in a thermoplastic resin or a thermosetting resin, and the hysteresis characteristics in the color density-temperature curve of the reversible thermochromic material are the same as the hysteresis characteristics in the color density-temperature curve of the reversible thermochromic composition.

[0012] Components (a), (b) and (c) of the reversible thermochromic composition applied to the present invention will be specifically explained below.

[0013] Component (A), that is, the electron-donating organic color-forming compound, is the component that determines the color, and is a compound that donates electrons to component (B), which is the color developer, to develop color.

[0014] Examples of the electron-donating color-forming organic compound include a phthalide compound, a fluoran compound, a styrinoquinoline compound, a diazarhodamine lactone compound, a pyridine compound, a quinazoline compound, and a bisquinazoline compound. Examples of the phthalide compound include a diphenylmethane phthalide compound, a phenylindolyl phthalide compound, an indolyl phthalide compound, a diphenylmethane azaphthalide compound, a phenylindolyl azaphthalide compound, and derivatives thereof. Among these, the phenylindolyl azaphthalide compound and derivatives thereof are preferred. Examples of fluoran compounds include aminofluoran compounds, alkoxyfluoran compounds, and derivatives thereof.

[0015] Examples of compounds that can be used as component (a) are given below. 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide, 3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide, 3,3-bis(1-n-butyl-2-methylindol-3-yl)phthalide, 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-n-hexyloxy-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, 3-(2-acetamido-4-diethylaminophenyl)-3-(1-propyl-2-methylindol-3-yl)-4-azaphthalide, 3,6-bis(diphenylamino)fluoran, 3,6-bis(N-phenyl-Np-tolylamino)fluoran, 3,6-dimethoxyfluoran, 3,6-di-n-butoxyfluorane, 2-methyl-6-(N-ethyl-Np-tolylamino)fluoran, 3-chloro-6-cyclohexylaminofluoran, 2-methyl-6-cyclohexylaminofluoran, 2-chloroamino-6-di-n-butylaminofluoran, 2-(2-chloroanilino)-6-di-n-butylaminofluoran, 2-(3-trifluoromethylanilino)-6-diethylaminofluoran, 2-(3-trifluoromethylanilino)-6-di-n-pentylaminofluoran, 2-dibenzylamino-6-diethylaminofluoran, 2-N-methylanilino-6-(N-ethyl-Np-tolylamino)fluoran, 1,3-dimethyl-6-diethylaminofluoran, 2-chloro-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methoxy-6-diethylaminofluoran, 2-anilino-3-methyl-6-di-n-butylaminofluoran, 2-anilino-3-methoxy-6-di-n-butylaminofluoran, 2-xylidino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-(N-ethyl-Np-tolylamino)fluoran, 6-diethylamino-1,2-benzofluoran, 6-(N-ethyl-N-isobutylamino)-1,2-benzofluoran, 6-(N-ethyl-N-isopentylamino)-1,2-benzofluoran, 2-(3-methoxy-4-dodecoxystyryl)quinoline, 2-diethylamino-8-diethylamino-4-methylspiro[5H-[1]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-(N-ethyl-N-isoamylamino)-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 2-di-n-butylamino-8-di-n-pentylamino-4-methylspiro[5H-[1]benzopyrano[2,3-d]pyrimidin-5,1′(3′H)-isobenzofuran]-3′-one, 4,5,6,7-tetrachloro-3-(4-dimethylamino-2-methoxyphenyl)-3-(1-n-butyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 4,5,6,7-tetrachloro-3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 4,5,6,7-tetrachloro-3-(4-diethylamino-2-ethoxyphenyl)-3-(1-n-pentyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 4,5,6,7-tetrachloro-3-(4-diethylamino-2-methylphenyl)-3-(1-ethyl-2-methylindol-3-yl)-1(3H)-isobenzofuranone, 3',6'-bis[phenyl(2-methylphenyl)amino]spiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3-one, 3',6'-bis[phenyl(3-methylphenyl)amino]spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one, 3',6'-bis[phenyl(3-ethylphenyl)amino]spiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one, 2,6-bis(2′-ethyloxyphenyl)-4-(4′-dimethylaminophenyl)pyridine, 2,6-bis(2′,4′-diethyloxyphenyl)-4-(4′-dimethylaminophenyl)pyridine, 2,6-bis(2,4-diethyloxyphenyl)-4-[4-bis(4-methyloxyphenyl)aminophenyl]pyridine, 2-(4′-dimethylaminophenyl)-4-methoxyquinazoline, 4,4'-Ethylenedioxy-bis[2-(4-diethylaminophenyl)quinazoline]

[0016] In addition, fluorans may be compounds having a substituent on the phenyl group forming the xanthene ring, or may be compounds that have a substituent on the phenyl group forming the xanthene ring and also have a substituent on the phenyl group forming the lactone ring (for example, an alkyl group such as a methyl group, or a halogen atom such as a chlorine atom), and that exhibit a blue or black color.

[0017] Component (b), ie, the electron accepting compound, is a compound that accepts electrons from component (a) and functions as a developer for component (a). The electron-accepting compound may be selected from the group consisting of compounds having an active proton, pseudo-acidic compounds (compounds that are not acids but act as acids in the reversible thermochromic composition to cause the color of component (A)), and compounds having an electron vacancy. Among the above-mentioned component (B), compounds selected from the group consisting of compounds having an active proton are preferred.

[0018] Examples of compounds having an active proton include compounds having a phenolic hydroxy group and derivatives thereof, carboxylic acids and derivatives thereof, acidic phosphate esters and derivatives thereof, azole compounds and derivatives thereof, 1,2,3-triazole and derivatives thereof, cyclic carbosulfimides, halohydrins having 2 to 5 carbon atoms, sulfonic acids and derivatives thereof, and inorganic acids. Preferred examples of carboxylic acids and derivatives thereof include aromatic carboxylic acids and derivatives thereof, or aliphatic carboxylic acids having 2 to 5 carbon atoms and derivatives thereof. Examples of the pseudo-acidic compounds include metal salts of compounds having a phenolic hydroxy group, metal salts of carboxylic acids, metal salts of acidic phosphate esters, metal salts of sulfonic acids, aromatic carboxylic acid anhydrides, aliphatic carboxylic acid anhydrides, mixed anhydrides of aromatic carboxylic acids and sulfonic acids, cycloolefin dicarboxylic acid anhydrides, urea and its derivatives, thiourea and its derivatives, guanidine and its derivatives, and halogenated alcohols. Compounds having electron vacancies include borates, borate esters, and inorganic salts.

[0019] Among the above-mentioned components (ii), compounds having a phenolic hydroxy group are preferred because they can more effectively exhibit thermochromic properties. Compounds having a phenolic hydroxy group include a wide range of compounds, from monophenol compounds to polyphenol compounds, and also include bisphenol compounds, trisphenol compounds, phenol-aldehyde condensation resins, etc. The compound having a phenolic hydroxy group preferably has at least two benzene rings. The compound having a phenolic hydroxy group may also have a substituent such as an alkyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a carboxyl group and its ester or amide group, or a halogen atom.

[0020] Examples of metals contained in metal salts of compounds having a phenolic hydroxy group include sodium, potassium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, and molybdenum.

[0021] Examples of compounds that can be used as component (b) are given below. Phenol, o-cresol, 4-np-nonylphenol, 4-n-octylphenol, 4-n-dodecylphenol, 4-n-stearylphenol, 4-chlorophenol, 4-bromophenol, 2-phenylphenol, n-butyl 4-hydroxybenzoate, n-octyl 4-hydroxybenzoate, resorcinol, 4-tert-butylcatechol, 2,4-dihydroxy-4′-tert-butylbenzophenone, dodecyl gallate, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)n-butane, 1,1-bis(4-hydroxyphenyl)n-pentane, 1,1-bis(4-hydroxyphenyl)n-hexane, 1,1-bis(4-hydroxyphenyl)n-heptane, 1,1-bis(4-hydroxyphenyl)n-octane, 1,1-bis(4-hydroxyphenyl)n-nonane, 1,1-bis(4-hydroxyphenyl)n-decane, 1,1-bis(4-hydroxyphenyl)n-dodecane, 1,1-bis(4-hydroxyphenyl)-2-methylpropane, 1,1-bis(4-hydroxyphenyl)n-methylpropane 1,1-bis(4-hydroxyphenyl)-3-methylbutane, 1,1-bis(4-hydroxyphenyl)-3-methylpentane, 1,1-bis(4-hydroxyphenyl)-2,3-dimethylpentane, 1,1-bis(4-hydroxyphenyl)-2-ethylbutane, 1,1-bis(4-hydroxyphenyl)-2-ethylhexane, 1,1-bis(4-hydroxyphenyl)-3,7-dimethyloctane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1-phenyl-1,1-bi bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)n-butane, 2,2-bis(4-hydroxyphenyl)n-pentane, 2,2-bis(4-hydroxyphenyl)n-hexane, 2,2-bis(4-hydroxyphenyl)n-heptane, 2,2-bis(4-hydroxyphenyl)n-octane, 2,2-bis(4-hydroxyphenyl)n-nonane, 2,2-bis(4-hydroxyphenyl)n-decane, 2,2-bis(4-hydroxyphenyl)n-dodecane, 2,2-bis(4-hydroxyphenyl)ethyl propionate, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 2,2-bis(4-hydroxyphenyl)-4-methylhexane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)butane, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,3-bis[2-(4-hydroxyphenyl) -2-propyl]benzene, bis(2-hydroxyphenyl)methane, 4,4'-dihydroxydiphenyl sulfone, 4-isopropoxy-4'-hydroxydiphenyl sulfone, bis(4-hydroxyphenyl) sulfide, 1,1,1-tris(4-hydroxyphenyl)ethane, 4,4'-[1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene]bisphenol, 4,4'-[4-(4-hydroxyphenyl)-sec-butylidene]bis(2-methylphenol),

[0022] The component (c) of the reaction medium that reversibly induces an electron donor-acceptor reaction between the components (a) and (b) in a specific temperature range will now be described. Examples of the component (c) include alcohols, esters, ketones, ethers, and acid amides.

[0023] As the alcohol, aliphatic monohydric saturated alcohols having 10 or more carbon atoms are effective. Examples of alcohols include decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, heptadecyl alcohol, octadecyl alcohol, eicosyl alcohol, and docosyl alcohol.

[0024] As the esters, esters having 10 or more carbon atoms are effective, and examples thereof include esters obtained from any combination of a monocarboxylic acid having an aliphatic and an alicyclic or aromatic ring and a monohydric alcohol having an aliphatic and an alicyclic or aromatic ring, esters obtained from any combination of a polycarboxylic acid having an aliphatic and an alicyclic or aromatic ring and a monohydric alcohol having an aliphatic and an alicyclic or aromatic ring, and esters obtained from any combination of a monocarboxylic acid having an aliphatic and an alicyclic or aromatic ring and a polyhydric alcohol having an aliphatic and an alicyclic or aromatic ring. Examples of esters include ethyl caprylate, octyl caprylate, stearyl caprylate, myristyl caprate, cetyl caprate, stearyl caprate, docosyl caprate, 2-ethylhexyl laurate, n-decyl laurate, 3-methylbutyl myristate, cetyl myristate, isopropyl palmitate, neopentyl palmitate, nonyl palmitate, cyclohexyl palmitate, n-butyl stearate, 2-methylbutyl stearate, 3,5,5-trimethylhexyl stearate, n-undecyl stearate, pentadecyl stearate, stearyl stearate, cyclohexylmethyl stearate, isopropyl behenate, hexyl behenate, lauryl behenate, behenyl behenate, cetyl benzoate, and p-tert-butyl benzoate. Examples of the alkyl acrylate include stearyl benzoate, dimyristyl phthalate, distearyl phthalate, dimyristyl oxalate, dicetyl oxalate, dicetyl malonate, dilauryl succinate, dilauryl glutarate, diundecyl adipate, dilauryl azelate, di-(n-nonyl) sebacate, dineopentyl 1,18-octadecylmethylenedicarboxylate, ethylene glycol dimyristate, propylene glycol dilaurate, propylene glycol distearate, hexylene glycol dipalmitate, 1,5-pentanediol distearate, 1,2,6-hexanetriol trimyristate, 1,4-cyclohexanediol didecyl, 1,4-cyclohexanedimethanol dimyristate, xylene glycol dicaprinate, and xylene glycol distearate.

[0025] Examples of ketones include diethyl ketone, ethyl butyl ketone, methyl hexyl ketone, mesityl oxide, cyclohexanone, methylcyclohexanone, acetophenone, propiophenone, benzophenone, acetylacetone, acetonylacetone, and diacetone alcohol.

[0026] Examples of ethers include butyl ether, hexyl ether, isopropyl benzyl ether, diphenyl ether, dioxane, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, and ethylene glycol diphenyl ether.

[0027] Examples of acid amides include acetamide, propionic acid amide, butyric acid amide, caproic acid amide, caprylic acid amide, capric acid amide, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, erucic acid amide, benzamide, caproic acid anilide, caprylic acid anilide, capric acid anilide, lauric acid anilide, myristic acid anilide, palmitic acid anilide, stearic acid anilide, behenic acid anilide, oleic acid anilide, erucic acid anilide, and N-methylcaproic acid anilide. amide, caprylic acid N-methylamide, capric acid N-methylamide, lauric acid N-methylamide, myristic acid N-methylamide, palmitic acid N-methylamide, stearic acid N-methylamide, behenic acid N-methylamide, oleic acid N-methylamide, erucic acid N-methylamide, lauric acid N-ethylamide, myristic acid N-ethylamide, palmitic acid N-ethylamide, stearic acid N-ethylamide, oleic acid N-ethylamide, lauric acid N-butylamide, myristic acid N-butylamide, palmitic acid N-butylamide, stearic acid N-ethylamide Phosphoric acid N-butylamide, oleic acid N-butylamide, lauric acid N-octylamide, myristic acid N-octylamide, palmitic acid N-octylamide, stearic acid N-octylamide, oleic acid N-octylamide, lauric acid N-dodecylamide, myristic acid N-dodecylamide, palmitic acid N-dodecylamide, stearic acid N-dodecylamide, oleic acid N-dodecylamide, dilauric acid amide, dimyristic acid amide, dipalmitic acid amide, distearic acid amide, dioleic acid amide, trilauric acid amide, tri Myristic acid amide, tripalmitic acid amide, tristearic acid amide, trioleic acid amide, succinic acid amide, adipic acid amide, glutaric acid amide, malonic acid amide, azelaic acid amide, maleic acid amide, succinic acid N-methylamide, adipic acid N-methylamide, glutaric acid N-methylamide, malonic acid N-methylamide, azelaic acid N-methylamide, succinic acid N-ethylamide, adipic acid N-ethylamide, glutaric acid N-ethylamide, malonic acid N-ethylamide, azelaic acid N-ethylamide, succinic acid N-butylamide,Examples include adipic acid N-butylamide, glutaric acid N-butylamide, malonic acid N-butylamide, adipic acid N-octylamide, and adipic acid N-dodecylamide.

[0028] Ester compounds exhibiting a ΔT value (melting point - cloud point) of 3°C or less (preferably 2.5°C or less) are also effective as component (c). Reversible thermochromic compositions using such ester compounds as component (c) have the properties of an extremely small hysteresis width (ΔH) and a sharp reversible change from a colored state to a discolored state. In other words, they can be made into reversible thermochromic compositions that change color with high sensitivity. Here, the smaller the difference (t2 - t1) between the color development onset temperature t2 and the complete color development temperature t1 of the reversible thermochromic composition and the smaller the difference (t4 - t3) between the complete discoloration temperature t4 and the discoloration onset temperature t3, the sharper the reversible change from the colored state to the discolored state, and the more sensitive the reversible thermochromic composition will be to change color.

[0029] Examples of ester compounds having a ΔT value of 3°C or less include esters of saturated fatty acids and branched fatty alcohols, esters of unsaturated fatty acids or branched or substituted saturated fatty acids and branched fatty alcohols or fatty alcohols having 16 or more carbon atoms, and ester compounds selected from cetyl butyrate, stearyl butyrate, and behenyl butyrate. For example, 2-ethylhexyl butyrate, 2-ethylhexyl behenate, 2-ethylhexyl myristate, 2-ethylhexyl caprate, 3,5,5-trimethylhexyl laurate, 3,5,5-trimethylhexyl palmitate, 3,5,5-trimethylhexyl stearate, 3,5,5-trimethylhexyl behenate, 2-methylbutyl caproate, 2-methylbutyl caprylate, 2-methylbutyl caprate, 1-ethylpropyl palmitate, 1-ethylpropyl stearate, 1-ethylpropyl behenate, laurate, 1-Ethylhexyl urate, 1-ethylhexyl myristate, 1-ethylhexyl palmitate, 2-methylpentyl behenate, 2-methylpentyl caproate, 2-methylpentyl caprylate, 2-methylpentyl caprate, 2-methylpentyl laurate, 2-methylbutyl stearate, 2-methylbutyl stearate, 3-methylbutyl stearate, 1-methylheptyl stearate, 2-methylbutyl behenate, 3-methylbutyl behenate, 1-methylheptyl stearate, 1-methylheptyl behenate , 1-ethylpentyl caproate, 1-ethylpentyl palmitate, 1-methylpropyl stearate, 1-methyloctyl stearate, 1-methylhexyl stearate, 1,1-dimethylpropyl laurate, 1-methylpentyl caprate, 2-methylhexyl palmitate, 2-methylhexyl stearate, 2-methylhexyl behenate, 3,7-dimethyloctyl laurate, 3,7-dimethyloctyl myristate, 3,7-dimethyloctyl palmitate, 3,7-dimethyloctyl stearate, Behen Examples include 3,7-dimethyloctyl phosphate, stearyl oleate, behenyl oleate, stearyl linoleate, behenyl linoleate, 3,7-dimethyloctyl erucate, stearyl erucate, isostearyl erucate, cetyl isostearate, stearyl isostearate, 2-methylpentyl 12-hydroxystearate, 2-ethylhexyl 18-bromostearate, isostearyl 2-ketomyristate, 2-ethylhexyl 2-fluoromyristate, cetyl butyrate, stearyl butyrate, and behenyl butyrate.

[0030] The reversible thermochromic composition is a compatible solution containing the above components (A), (B), and (C) as essential components. The proportions of each component depend on the concentration, discoloration temperature, discoloration form, and type of each component, but generally, the component ratios that achieve the desired properties are 1 part of component (A) to 0.1 to 100 parts of component (B), preferably 0.1 to 50 parts, more preferably 0.5 to 20 parts, and even more preferably 2 to 20 parts, and 1 to 800 parts of component (C), preferably 5 to 200 parts, more preferably 5 to 100 parts, and even more preferably 10 to 100 parts (all of the above proportions are in parts by mass).

[0031] The reversible thermochromic composition of the present invention may contain various light stabilizers, if necessary. The light stabilizer is included to prevent photodegradation of the reversible thermochromic composition consisting of components (A), (B), and (C). The component ratio that achieves the desired properties is 0.3 to 24 parts, preferably 0.3 to 16 parts, of light stabilizer per 1 part of component (A) (all ratios are in parts by mass). Among the light stabilizers, the ultraviolet absorber effectively blocks ultraviolet light contained in sunlight and prevents photodegradation caused by the excited state due to the photoreaction of component (A). Furthermore, antioxidants, singlet oxygen quenchers, superoxide anion quenchers, ozone quenchers, etc., suppress photooxidation reactions. The light stabilizers can be used alone or in combination of two or more.

[0032] The reversible thermochromic composition is encapsulated in microcapsules to be used as a reversible thermochromic microcapsule pigment (hereinafter sometimes referred to as a "microcapsule pigment"), or dispersed in a thermoplastic resin or a thermosetting resin to be used as a reversible thermochromic resin particle (hereinafter sometimes referred to as a "resin particle"). The reversible thermochromic composition is preferably encapsulated in microcapsules to form a reversible thermochromic microcapsule pigment. By encapsulating the reversible thermochromic composition in microcapsules, a chemically or physically stable pigment can be formed, and the reversible thermochromic composition can maintain the same composition under various use conditions and exhibit the same effects.

[0033] Microencapsulation can be performed by known methods such as isocyanate-based interfacial polymerization, in situ polymerization such as melamine-formalin polymerization, in-liquid curing coating, phase separation from an aqueous solution, phase separation from an organic solvent, melt-dispersion cooling, air suspension coating, and spray drying, and can be selected appropriately depending on the application.

[0034] Depending on the purpose, the surface of the microcapsules may be further provided with a resin film or the like, thereby imparting durability or modifying the surface properties.

[0035] The reversible thermochromic microcapsule pigment comprises a microcapsule wall (wall material) and an inclusion (including a reversible thermochromic composition) encapsulated therein, with the mass ratio of inclusion to wall being preferably 7:1 to 1:1. By having the mass ratio of inclusion to wall within the above range, it is possible to prevent a decrease in color density and clarity during color development. More preferably, the mass ratio of inclusion to wall is 6:1 to 1:1.

[0036] The average particle size of the reversible thermochromic microencapsulated pigment or resin particles is preferably 0.01 to 50 μm, more preferably 0.1 to 30 μm, and even more preferably 0.5 to 20 μm. If the average particle size exceeds 50 μm, dispersion stability and processability are poor when blended into ink, paint, or resin. On the other hand, if the average particle size is less than 0.01 μm, it becomes difficult to achieve high-concentration color development.

[0037] The average particle diameter was measured by determining the particle area using image analysis particle size distribution measurement software (manufactured by Mountec Co., Ltd., product name: MacView), calculating the diameter equivalent to a circle with a projected area (Heywood diameter) from the area of ​​the particle area, and measuring the average particle diameter of particles equivalent to a sphere of equal volume using this value. If the particle size of all or the majority of particles exceeds 0.2 μm, it is also possible to measure the average particle size of particles equivalent to an equal volume sphere using the Coulter method using a particle size distribution analyzer (Beckman Coulter, Inc., product name: Multisizer 4e). Furthermore, the volumetric particle size and average particle size may be measured using a calibrated laser diffraction / scattering particle size distribution analyzer (manufactured by HORIBA, Ltd., product name: LA-960V2) based on values ​​measured using the above software or a measuring device using the Coulter method.

[0038] [First embodiment] The model provided on the substrate of the writing learning tool according to the present invention is selected from the group consisting of letters, numbers, and symbols, and reversibly changes color from one color to a different color. That is, it exhibits an alternating color change from a first color to a second color. This occurs because the reversible thermochromic material reversibly changes from a colored state to a colorless state in response to a temperature change. The combined use of a reversible thermochromic material and a non-thermochromic material produces the effect of the model reversibly changing color from one color to a different color (reversibly changing color from a first color to a second color). The color (first color) is the color that the reversible thermochromic material shows when it is in a colored state, and is a mixture of the color of the reversible thermochromic material in the colored state and the color of the non-thermochromic material.A different color (second color) from the color is the color that the reversible thermochromic material shows when it is in a colorless state, and is the color of the non-thermochromic material only. Reversible color changes from one color to another include changes in tone (e.g., from dark to light) and changes in hue (e.g., from purple to pink, or from green to yellow). As the non-thermochromic material, at least one of a general dye and a general pigment can be used.

[0039] The reversible thermochromic material according to the present invention is a material that has a complete decolorization temperature t4 of 26 to 37°C and exhibits a hysteresis width (ΔH) of 5°C or less on the color density-temperature curve. Because the reversible thermochromic material's complete decolorization temperature t4 is between 26 and 37°C, which is higher than room temperature and below normal human body temperature, the reversible thermochromic material remains in a colored state at room temperature. In other words, in the initial state, the writing learning tool of the present invention visually displays a model in a color that is a mixture of the color of the reversible thermochromic material in its colored state and the color of the non-thermochromic material. When the user of the writing learning tool touches the model with their fingers or other objects and traces the model from this state, heat (body heat) from the fingers or other objects is applied to the reversible thermochromic material in the traced area, causing the reversible thermochromic material to decolorize, and the model in the color of the non-thermochromic material becomes visible. In other words, the color of the model changes in the traced area, stimulating the user's visual sense, allowing the user to learn letters and characters with a sense of real writing. Furthermore, because the model changes color when the user traces the model correctly, a third party can visually confirm whether the user is tracing the model correctly. A reversible thermochromic material is a material that has a hysteresis width (ΔH) of 5°C or less in the color density-temperature curve, and it is difficult to maintain either the colored state or the colorless state alternatively, so a reversible change from the colored state to the colorless state occurs easily. Therefore, after tracing the example with a finger or the like, the reversible thermochromic material in the colorless state quickly changes color, and the writing learning tool returns to its initial state, so the writing learning tool can be used repeatedly. The writing learning tool of the present invention can be used repeatedly because the color change of the model is reversible, and allows the user to learn efficiently with the feeling of actually writing, and also allows a third party to judge whether the user is correctly tracing the model and learning. In the present invention, "room temperature" refers to a temperature range of 15 to 25°C, which is a temperature at which people can feel comfortable, and "normal human body temperature" refers to a temperature range of 35 to 37°C.

[0040] The complete decolorization temperature t4 of the reversible thermochromic material is 26 to 37°C, which is a temperature higher than room temperature but lower than the normal human body temperature, at which the material reversibly changes from a colored state to a decolored state upon contact with a finger or the like.Since the material can be easily changed upon contact with a finger or the like, the temperature is preferably 27 to 35°C, and more preferably 28 to 33°C. The hysteresis width (ΔH) of the color density-temperature curve of the reversible thermochromic material is 5°C or less, which allows the sample to change color quickly, and is therefore preferably 3°C or less, more preferably 2°C or less.

[0041] It is preferable that the sample changes color quickly when traced with a finger or the like, and that the sample quickly returns to its original color after tracing. In other words, it is preferable that the reversible thermochromic material undergoes a sharp reversible change from a colored state to a colorless state, that is, changes color with high sensitivity, and therefore t2-t1 and t4-t3 are preferably 10°C or less, more preferably 6°C or less, even more preferably 5°C or less, and particularly preferably 3°C or less.

[0042] The writing learning tool of the present invention allows the reversible thermochromic material to easily return to its initial colored state after tracing the model with a finger or the like without using a cooling device or the like, and therefore the complete color development temperature t1 of the reversible thermochromic material is preferably 25 to 30°C, more preferably 26 to 29°C.

[0043] The writing learning tool according to the present invention can be obtained by printing or applying a reversible thermochromic liquid composition, such as ink or paint, containing a reversible thermochromic material and a non-thermochromic material in a vehicle containing a binder resin onto a substrate, thereby providing a reversible thermochromic image on the substrate that reversibly changes color from one color to a different color. Examples of methods for printing or applying the reversible thermochromic liquid composition on a substrate include printing methods such as screen printing, offset printing, gravure printing, coater printing, and transfer printing, and application methods such as brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, and dip coating.

[0044] The above-mentioned reversibly thermochromic liquid composition may be either a reversibly thermochromic material dispersed in a vehicle containing a non-thermochromic material, or a reversibly thermochromic material and a non-thermochromic material dispersed in a vehicle. Examples of reversible thermochromic materials that contain non-thermochromic materials include reversible thermochromic microcapsule pigments that contain both a reversible thermochromic composition and a non-thermochromic material, or reversible thermochromic resin particles that contain both a reversible thermochromic composition and a non-thermochromic material dispersed in a thermoplastic resin or a thermosetting resin.

[0045] A writing learning tool can be obtained by printing or applying a non-thermochromic liquid composition, such as ink or paint, in which a non-thermochromic material is dispersed in a vehicle containing a binder resin, to a substrate to form a non-thermochromic image on the substrate, and then printing or applying a reversible thermochromic liquid composition, such as ink or paint, in which a reversible thermochromic material is dispersed in a vehicle containing a binder resin, to the non-thermochromic image to form a reversible thermochromic image that reversibly changes color from colored to colorless on the non-thermochromic image. Here, the non-thermochromic image and the reversible thermochromic image are images of the same size and shape. Methods for printing or applying the non-thermochromic liquid composition and the reversible thermochromic liquid composition onto a substrate include the same printing or application methods as those described above.

[0046] The reversible thermochromic image and the non-thermochromic image are formed by drying and solidifying a liquid composition, and are formed from components other than volatile components. The reversible thermochromic liquid composition and the non-thermochromic liquid composition may be printed or applied once to a substrate and then dried and solidified to form a reversible thermochromic image and a non-thermochromic image, but the density of the reversible thermochromic image and the non-thermochromic image can be improved by printing or applying the ink composition multiple times.

[0047] The binder resin is not particularly limited as long as it does not affect the coloring, fading, or discoloration of reversibly thermochromic materials or the coloring, etc. of non-thermochromic materials. Examples include ionomer resins, isobutylene-maleic anhydride copolymer resins, acrylonitrile-acrylic styrene copolymer resins, acrylonitrile-styrene copolymer resins, acrylonitrile-butadiene-styrene copolymer resins, acrylonitrile-chlorinated polyethylene-styrene copolymer resins, ethylene-vinyl chloride copolymer resins, ethylene-vinyl acetate copolymer resins, ethylene-vinyl acetate-vinyl chloride graft copolymer resins, vinylidene chloride resins, vinyl chloride resins, chlorinated vinyl chloride resins, vinyl chloride-vinylidene chloride copolymer resins, chlorinated polyethylene, chlorinated polypropylene, polyamide, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polystyrene, high-impact polystyrene, polypropylene, polymethylstyrene, polyacrylic esters, polymethyl methacrylate, epoxy acrylate resins, alkylphenol resins, and rosin. Examples of the resin include modified phenolic resins, rosin-modified alkyd resins, phenolic resin-modified alkyd resins, epoxy resin-modified alkyd resins, styrene-modified alkyd resins, acrylic-modified alkyd resins, aminoalkyd resins, vinyl chloride-vinyl acetate resins, styrene-butadiene resins, epoxy resins, unsaturated polyesters, saturated polyesters, polyurethanes, alkyd resins, natural rubber, polyisobutylene, butyl rubber, polyvinyl alkyl ethers, rosin, rosin esters, rosin derivatives, polyterpenes, oil-soluble phenolic resins, petroleum-based hydrocarbon resins, shellac, cyclized rubbers, vinyl acetate-based emulsion resins, styrene-butadiene-based emulsion resins, acrylic acid ester-based emulsion resins, water-soluble alkyd resins, water-soluble melamine resins, water-soluble urea resins, water-soluble phenolic resins, water-soluble epoxy resins, water-soluble polybutadiene, cellulose acetate, cellulose nitrate, and ethyl cellulose.

[0048] The model is selected from the group consisting of letters, numbers, and symbols, such as various characters such as hiragana, katakana, kanji, the alphabet, and Greek letters; various numbers such as Arabic numerals and Roman numerals; and various symbols such as musical notes, yen signs, percent signs, ampersands, exclamation marks, and question marks.

[0049] The substrate is not particularly limited as long as it is capable of forming a model (a reversible thermochromic image or a non-thermochromic image), and the substrate also serves as a support for the model (a reversible thermochromic image or a non-thermochromic image). The material of the substrate is not limited, and examples thereof include paper, synthetic paper, fiber, fabric, synthetic leather, leather, plastic, foam, glass, elastomer, rubber, ceramic material, metal material, wood, stone, etc. As for the form, flat, sheet, or film form is preferable.

[0050] The writing learning tool of the present invention can use a reversible thermochromic laminate having a structure in which a reversible thermochromic image that reversibly changes color from a color to a different color is provided on a substrate, or a reversible thermochromic laminate having a structure in which a non-thermochromic image is provided on a substrate and a reversible thermochromic image that reversibly changes color from a color to a colorless image and has the same size and shape as the non-thermochromic image is provided on the non-thermochromic image.

[0051] [Second embodiment] The model provided on the substrate of the writing learning tool of the present invention is selected from the group consisting of letters, numbers, and symbols, and is composed of a non-thermochromic image and a reversible thermochromic image that reversibly changes color from colored to colorless, and at least one of its size and shape changes with temperature. The model remains the same before and after the temperature change. This is due to the reversible thermochromic material reversibly changing from a colored state to a colorless state with temperature change. The combined use of a reversible thermochromic material and a non-thermochromic material results in the model changing in size or shape with temperature change. In other words, the model visible on the writing learning tool in its initial state, when the reversible thermochromic material is in its colored state, can be of different sizes and / or shapes from the model visible when the user of the writing learning tool traces the model with their own finger, etc. Specifically, when a user traces the model with their fingers or other objects in the initial state of the writing learning tool, heat (body heat) from the fingers or other objects is applied to the reversible thermochromic material at the traced area, causing the reversible thermochromic material to disappear. This allows a non-thermochromic image of the model to be visually recognized, differing in at least one of size and shape from the model in the initial state of the writing learning tool. In other words, because at least one of the size and shape of the model at the traced area changes, the user's visual sense is stimulated, allowing the user to learn characters and other characters with a sense of actual writing. Furthermore, because at least one of the size and shape of the model changes when the model is traced correctly, a third party can visually confirm whether the user is tracing the model correctly. In the present invention, "the same letters, numbers, or symbols before and after the temperature change" means that the letters, numbers, or symbols are the same type before and after the temperature change. In other words, if the example before the temperature change is the hiragana "a", the example after the temperature change will also be the hiragana "a", but this does not include the example after the temperature change being the hiragana "i" or the katakana "a". The reversible thermochromic material can be the same as that used in the above-described embodiment (first embodiment), and therefore a detailed description thereof will be omitted.

[0052] The model is composed of a non-thermochromic image and a reversible thermochromic image that reversibly changes color from colored to colorless. The model may be configured in a layered configuration in which a non-thermochromic image and a reversible thermochromic image that reversibly changes color from colored to colorless are layered, or in a juxtaposed configuration in which a non-thermochromic image and a reversible thermochromic image that reversibly changes color from colored to colorless are arranged side by side. As described below, "the color produced by the reversible thermochromic material in the colored state is the same as the color produced by the non-thermochromic material" means that the hue and tone of the two are the same and there is absolutely no difference between them. This invention also includes cases where there is a difference between the two to the extent that they appear to have the same hue and tone. Furthermore, "the color produced by the reversible thermochromic material in the colored state is different from the color produced by the non-thermochromic material" means that the hue and tone of the two are different (not identical). Here, hue refers to a color such as blue, green, or yellow, and tone refers to the shade of a color.

[0053] In a laminated structure, a non-thermochromic image smaller than the reversible thermochromic image is provided on a reversible thermochromic image that reversibly changes color from colored to colorless. In this structure, the non-thermochromic image conceals part of the reversible thermochromic image, and the reversible thermochromic image is arranged around the non-thermochromic image. That is, in the initial state of the writing learning tool, a model combining the reversible thermochromic image and the non-thermochromic image is visible, and when the model is traced with a finger or the like, the reversible thermochromic material disappears, and the model consisting only of the non-thermochromic image is visible. For example, if the color of the reversible thermochromic material in the colored state and the color of the non-thermochromic material are the same, in the initial state of the writing learning tool, a model in which the reversible thermochromic image and the non-thermochromic image are combined will be visible. Then, with a change in temperature, only the non-thermochromic image will be visible, and a model that is relatively smaller than the initial model will be visible. In other words, the size of the model will change with a change in temperature. Furthermore, when the color of the reversible thermochromic material in the colored state differs from the color of the non-thermochromic material, the reversible thermochromic image and the non-thermochromic image are combined in the initial state of the writing learning tool, and the area inside the border is outlined with the color of the reversible thermochromic material in the colored state, and the model (i.e., outlined letters) is visible. Then, with a change in temperature, only the non-thermochromic image remains, and a model without the border and relatively smaller than the initial model is visible. In other words, the size and shape of the model change with temperature.

[0054] In a laminated structure, a reversible thermochromic image that reversibly changes color from colored to colorless and is larger than or the same size as the non-thermochromic image is provided on top of the non-thermochromic image. In this structure, the reversible thermochromic image completely conceals the non-thermochromic image. That is, in the initial state of the writing learning tool, the model is visible only as the reversible thermochromic image, but when the model is traced with a finger or the like, the reversible thermochromic material disappears, and the model is visible only as the non-thermochromic image. For example, if the reversible thermochromic image is larger than the non-thermochromic image, the model will be visible only as the reversible thermochromic image in the initial state of the writing learning tool. Then, with a temperature change, only the non-thermochromic image will be visible, and a model relatively smaller than the reversible thermochromic image will be visible. In other words, the size of the model will change with temperature change. Furthermore, when the reversible thermochromic image and the non-thermochromic image are the same size and are stacked so that the reversible thermochromic image coincides with the non-thermochromic image, an example configuration is possible in which the reversible thermochromic image is a solid line and the non-thermochromic image is a line other than the solid line (e.g., a dotted line, a dashed line, a chain line, etc.). In this case, in the initial state of the writing learning tool, a solid line model made up of only the reversible thermochromic image is visible. Then, only the non-thermochromic image caused by temperature change is visible, and a line other than the solid line (dotted line, a dashed line, a chain line, etc.) model is visible. In other words, the shape of the model changes with temperature change.

[0055] In the initial state of the writing learning tool, it is preferable that the non-thermochromic image located underneath the reversible thermochromic image is difficult to see, which can add a sense of surprise to the changes in the model due to temperature changes. From the viewpoint of concealing the reversible thermochromic image, it is preferable that the color exhibited by the reversible thermochromic material in the colored state is a dark color such as black, navy blue, or dark brown. Furthermore, if the color of the reversible thermochromic material in the colored state and the color of the non-thermochromic material are the same hue, the color of the reversible thermochromic material in the colored state can be darker than the color of the non-thermochromic material, thereby improving the concealing ability of the reversible thermochromic image.

[0056] In a laminated structure, a reversible thermochromic image that changes color from colored to colorless and is smaller than the non-thermochromic image is provided on top of the non-thermochromic image. In this structure, the reversible thermochromic image conceals part of the non-thermochromic image, and the non-thermochromic image is arranged around the reversible thermochromic image. That is, in the initial state of the writing learning tool, a model that combines the reversible thermochromic image and the non-thermochromic image is visible, and when the model is traced with a finger or the like, the reversible thermochromic material disappears, and the model consisting only of the non-thermochromic image is visible. For example, if the color of the reversible thermochromic material in the colored state is different from the color of the non-thermochromic material, in the initial state of the writing learning tool, the reversible thermochromic image and the non-thermochromic image are combined, and the inside of the border is outlined in the color of the reversible thermochromic material in the colored state (i.e., outlined letters) is visible. Then, with a change in temperature, only the non-thermochromic image remains, and an unbordered example consisting only of the non-thermochromic image is visible. In other words, the shape of the example changes with temperature.

[0057] In the juxtaposed configuration, the non-thermochromic image is arranged around the reversible thermochromic image, which reversibly changes color from colored to colorless. In this configuration, in the initial state of the writing learning tool, a model consisting of a combination of the reversible thermochromic image and the non-thermochromic image is visible, and when the model is traced with a finger or the like, the reversible thermochromic material disappears, and the model consisting of only the non-thermochromic image is visible. For example, if the color of the reversible thermochromic material in the colored state is the same as the color of the non-thermochromic material, the initial state of the writing learning tool will show a model in which the reversible thermochromic image and the non-thermochromic image are combined. Then, with a temperature change, only the non-thermochromic image will be visible, outlined with the color of the non-thermochromic material, and the inside of the outline will be the model (i.e., white letters) whose color is that of the base material (typically white). In other words, the shape of the model changes with temperature changes. Furthermore, when the color of the reversible thermochromic material in the colored state differs from the color of the non-thermochromic material, in the initial state of the writing learning tool, a model is visible that is outlined in the color of the non-thermochromic material, with the interior of the outline being the color of the reversible thermochromic material in the colored state. Then, with a change in temperature, only the non-thermochromic image remains, and a model (i.e., outlined letters) is visible that is outlined in the color of the non-thermochromic material, with the interior of the outline being the color of the base material (typically white). In other words, the shape of the model changes with a change in temperature.

[0058] In the parallel arrangement, a reversible thermochromic image that reversibly changes color from colored to colorless is arranged around a non-thermochromic image. In this arrangement, in the initial state of the writing learning tool, a model that combines the reversible thermochromic image and the non-thermochromic image is visible, and when the model is traced with a finger or the like, the reversible thermochromic material disappears, and the model consisting only of the non-thermochromic image is visible. For example, if the color of the reversible thermochromic material in the colored state and the color of the non-thermochromic material are the same, in the initial state of the writing learning tool, a model in which the reversible thermochromic image and the non-thermochromic image are combined will be visible. Then, with a change in temperature, only the non-thermochromic image will be visible, and a model that is relatively smaller than the initial model will be visible. In other words, the size of the model will change with a change in temperature. Furthermore, when the color of the reversible thermochromic material in the colored state differs from the color of the non-thermochromic material, the writing learning tool in its initial state is outlined in the color of the reversible thermochromic material in the colored state, and the inside of the outline is visible as a model (i.e., outlined letters) in the color of the non-thermochromic material. Then, with a change in temperature, only the non-thermochromic image remains, and a model that is relatively smaller than the initial model without the border is visible. In other words, the size and shape of the model change.

[0059] In addition, in a side-by-side configuration, the shape of the line formed from the reversible thermochromic image and the non-thermochromic image may be different from the shape of the line formed from only the non-thermochromic image, i.e., the shape of the line forming the model may be different when the reversible thermochromic material is in a colored state and when it is in a decolored state. For example, if the reversible thermochromic images are dotted lines and the non-thermochromic images are dashed lines, and the reversible thermochromic images and non-thermochromic images are arranged alternately, the reversible thermochromic images and non-thermochromic images will combine to form a dashed-dotted line model in the initial state of the writing learning tool. Then, with a change in temperature, only the non-thermochromic images will be visible, resulting in a dashed line model consisting of only the non-thermochromic images. Also, if both the reversible thermochromic images and non-thermochromic images are dashed lines, and the reversible thermochromic images and non-thermochromic images are arranged alternately so that the dashed lines are in contact with each other, the reversible thermochromic images and non-thermochromic images will combine to form a solid line model in the initial state of the writing learning tool. Then, with a change in temperature, only the non-thermochromic images will be visible, resulting in a dashed line model consisting of the non-thermochromic images. Furthermore, when both the reversible thermochromic image and the non-thermochromic image are formed as dots and arranged alternately, the reversible thermochromic image and the non-thermochromic image are combined in the initial state of the writing learning tool, resulting in a dotted line model being visible. Then, with a temperature change, only the non-thermochromic image remains, and a dotted line model with wider dot spacing than the initial model is visible. In other words, the shape of the model changes with temperature changes.

[0060] The writing learning tool according to the present invention can be obtained by printing or applying a non-thermochromic liquid composition, such as ink or paint, in which a non-thermochromic material is dispersed in a vehicle containing a binder resin, onto a substrate to form a non-thermochromic image on the substrate, and then printing or applying a reversible thermochromic liquid composition, such as ink or paint, in which a reversible thermochromic material is dispersed in a vehicle containing a binder resin, onto the non-thermochromic image to form a reversible thermochromic image that reversibly changes color from colored to colorless, superimposed on the non-thermochromic image. Alternatively, the reversible thermochromic liquid composition can be printed or applied onto a substrate to provide a reversible thermochromic image on the substrate that reversibly changes color from colored to colorless, and then a non-thermochromic liquid composition can be printed or applied onto the reversible thermochromic image to provide a non-thermochromic image laminated on the reversible thermochromic image. Alternatively, the reversible thermochromic liquid composition and the non-thermochromic liquid composition can be printed or applied to a substrate, respectively, to provide a reversible thermochromic image and a non-thermochromic image, which reversibly change color from colored to colorless, side by side on the substrate, thereby obtaining the image. Methods for printing or applying the non-thermochromic liquid composition and the reversible thermochromic liquid composition onto a substrate include the same printing or application methods as those described above. The binder resin and the substrate can be the same as those used in the above-described embodiment (first embodiment), and therefore detailed description thereof will be omitted.

[0061] The model is selected from the group consisting of letters, numbers, and symbols, such as various characters such as hiragana, katakana, kanji, the alphabet, and Greek letters; various numbers such as Arabic numerals and Roman numerals; and various symbols such as musical notes, yen signs, percent signs, ampersands, exclamation marks, and question marks.

[0062] The writing learning tool of the present invention can use a reversible thermochromic laminate having a configuration in which a non-thermochromic image and a reversible thermochromic image that reversibly changes color from colored to colorless are provided in this order on a substrate. It can also use a reversible thermochromic laminate having a configuration in which a reversible thermochromic image that reversibly changes color from colored to colorless and a non-thermochromic image that is smaller than the reversible thermochromic image are provided in this order on a substrate. It can also use a reversible thermochromic laminate having a configuration in which a non-thermochromic image and a reversible thermochromic image are provided side by side on a substrate.

[0063] The model according to the present invention may use two or more types of reversible thermochromic materials, preferably two or more types of reversible thermochromic materials with at least different decolorization onset temperatures t3. In other words, the reversible thermochromic material according to the present invention may use two or more types of reversible thermochromic materials in combination, preferably two or more types of reversible thermochromic materials with at least different decolorization onset temperatures t3. This allows the model to change color gradually when traced with a finger or the like, or to change at least one of its size or shape gradually, or to change both its color and its size or shape, thereby further stimulating the user's visual sense and promoting the learning of letters, etc. Hereinafter, the complete color development temperature of the first reversible thermochromic material is referred to as t 1-1 , the color development start temperature is t 2-1 , the decolorization starting temperature is t 3-1 , the complete decolorization temperature is t 4-1 The complete color development temperature of the nth reversible thermochromic material is t 1-n , the color development start temperature is t 2-n , the decolorization starting temperature is t 3-n , the complete decolorization temperature is t 4-n (n is an integer of 2 or greater). When the sample contains two or more types of reversible thermochromic materials, the sample can be a reversible thermochromic image that changes color from color to a different color and contains both two or more types of reversible thermochromic materials and non-thermochromic materials. Alternatively, the sample may be composed of a reversible thermochromic image that changes color reversibly from color to colorless and contains both two or more types of reversible thermochromic materials, and a non-thermochromic image that contains a non-thermochromic material. Alternatively, the sample may be composed of two or more reversible thermochromic images (a first reversible thermochromic image containing a first reversible thermochromic material and an nth reversible thermochromic image (n is an integer of 2 or greater) containing an nth reversible thermochromic material), each containing two or more types of reversible thermochromic materials, and a non-thermochromic image.

[0064] For example, the following example includes a first reversible thermochromic material that exhibits a blue color in the colored state, a second reversible thermochromic material that exhibits a blue color in the colored state, and a yellow non-thermochromic material. In its initial state, the sample shows a dark green color, a mixture of blue and yellow, but when it is traced with a finger, one of the reversible thermochromic materials fades first, and the sample changes from light green to yellow. In other words, the color changes gradually from one color (first color, green) to a different color (second color, yellow) with a change in hue.

[0065] For example, the sample may include a first reversible thermochromic material that exhibits blue in the colored state, a second reversible thermochromic material that exhibits pink in the colored state, and a yellow non-thermochromic material, and the first reversible thermochromic material has a color-disappearing starting temperature t 3-1 is the decolorization starting temperature t of the second reversible thermochromic material 3-2 The smaller case is shown below. In its initial state, the sample shows a brown color, a mixture of blue, pink, and yellow, but when it is traced with a finger, the first reversible thermochromic material loses its color first, and the sample changes from orange, a mixture of pink and yellow, to yellow. In other words, the color changes gradually from one color (first color, brown) to a different color (second color, yellow).

[0066] For example, the following shows a sample in which a solid reversible thermochromic image of the same size as the dotted non-thermochromic image is layered on top of the non-thermochromic image so that it matches the non-thermochromic image, and the sample includes a first reversible thermochromic material that exhibits blue in the colored state, a second reversible thermochromic material that exhibits blue in the colored state, and a blue non-thermochromic material. The model initially appears as a dark blue solid line, but when traced with a finger, one of the reversible thermochromic materials fades first, and the model changes from a mixture of a light blue solid line and a blue dotted line to a blue dotted line. In other words, the shape changes along with the change in color tone.

[0067] The reversible thermochromic image formed using two or more kinds of reversible thermochromic materials may be applied to a learning tool. That is, a learning tool having a reversible thermochromic image provided on a substrate, the learning tool comprising two or more kinds of reversible thermochromic materials, the reversible thermochromic material being a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling the color reaction of the components (a) and (b), or a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition dispersed in a thermoplastic resin or a thermosetting resin. The learning tool may be a thermochromic resin particle that exhibits hysteresis characteristics with respect to the color density-temperature curve, exhibiting alternation between a colored state and a decolored state, and in the process of temperature rise from the colored state, begins to decolor when it reaches the decoloring start temperature t3, and becomes completely decolored in a temperature range above the complete decoloring temperature t4, which is higher than temperature t3, and in the process of temperature decrease from the decolored state, begins to color when it reaches the coloring start temperature t2, and becomes completely colored in a temperature range below the complete coloring temperature t1, which is lower than temperature t2. In such learning tools, the reversible thermochromic image changes color gradually, or at least one of the size and shape changes gradually, or at least one of the size and shape changes along with the color change, so that the change in the reversible thermochromic image further stimulates the user's vision and enhances the effectiveness of learning.

[0068] Furthermore, when two or more reversible thermochromic materials using an ester compound with a ΔT value of 3°C or less as component (c) are used in combination, the model will exhibit a behavior in which the low-temperature discoloration point of the reversible thermochromic material used in combination with the lowest discoloration point (i.e., complete color development temperature t1 and complete discoloration temperature t3) becomes the low-temperature discoloration point of the model. Similarly, the model will exhibit a color change behavior in which the high-temperature discoloration point of the reversible thermochromic material used in combination with the highest discoloration point (i.e., color development temperature t2 and complete discoloration temperature t4) becomes the high-temperature discoloration point of the model. Specifically, the sample includes a first reversible thermochromic material and a second reversible thermochromic material, and the first reversible thermochromic material has a complete color temperature t 1-1 , color onset temperature t 2-1 , decolorization start temperature t 3-1 , complete decolorization temperature t 4-1 All of these are at the complete color-changing temperature t 1-2 , color onset temperature t 2-2 , decolorization start temperature t 3-2 , complete decolorization temperature t 4-2 The configuration for the lower case will be explained. In this case, the first reversible thermochromic material has a lower low-temperature color change point (complete color development temperature t1 and color disappearance temperature t3), while the second reversible thermochromic material has a higher high-temperature color change point (color development temperature t2 and color disappearance temperature t4). 1-1 and the color-developing starting temperature t2 is the color-developing starting temperature t 2-2 and the decolorization starting temperature t3 is the decolorization starting temperature t 3-1 and the complete bleaching temperature t4 is the complete bleaching temperature t 4-2 This becomes: In this way, if the model is a combination of two reversible thermochromic materials using an ester compound that has a ΔT value of 3°C or less as component (c), the low-temperature discoloration point of one reversible thermochromic material (first reversible thermochromic material) and the high-temperature discoloration point of the other reversible thermochromic material (second reversible thermochromic material) can be considered to be the low-temperature discoloration point and high-temperature discoloration point of the model. Therefore, by using two or more types of reversible thermochromic materials in combination, when the model is traced with a finger or the like, the model gradually changes color, or gradually changes at least one of its size or shape, or at least one of its size or shape changes along with the color change, thereby providing the aforementioned effect of further stimulating the user's vision and encouraging learning of letters, etc., and in addition to this, the color change behavior of the model can be easily adjusted, making it easy to obtain a writing learning tool that changes color at the desired temperature.

[0069] A reversible thermochromic image made of two or more reversible thermochromic materials using an ester compound exhibiting a ΔT value of 3°C or less as the component (c) may be applied to a learning tool. That is, a learning tool having a reversible thermochromic image provided on a substrate, the learning tool comprising two or more reversible thermochromic materials, the reversible thermochromic material being a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that controls the color reaction of the components (a) and (b), or reversible thermochromic resin particles in which the reversible thermochromic composition is dispersed in a thermoplastic resin or a thermosetting resin, and the color density-temperature The learning tool may also be one that exhibits hysteresis characteristics in terms of the curve, exhibiting alternation between the colored state and the decolored state, and in the process of temperature rise from the colored state, it begins to decolor when it reaches the decoloring starting temperature t3, and becomes completely decolored in a temperature range above the complete decoloring temperature t4, which is higher than temperature t3, and in the process of temperature decrease from the decolored state, it begins to color when it reaches the coloring starting temperature t2, and becomes completely colored in a temperature range below the complete coloring temperature t1, which is lower than temperature t2, and in which the component (c) is an ester compound that exhibits a ΔT value (melting point - cloud point) of 3°C or less. In such learning tools, the reversible thermochromic image changes color gradually, or at least one of the size and shape changes gradually, or at least one of the size and shape changes along with the color change, so in addition to the above-mentioned effect that the change in the reversible thermochromic image further stimulates the user's vision and enhances the learning effect, the color change behavior of the reversible thermochromic image can be easily adjusted, and learning tools can be easily obtained in which the reversible thermochromic image changes color at a desired temperature.

[0070] In the writing learning tool of the present invention, the complete color change temperature t3 of the reversible thermochromic material is preferably 25°C or less, and more preferably 20 to 25°C, from the viewpoint that the writing learning tool can easily erase the model and make the traced area easily visible regardless of factors such as the ambient temperature in which the learning tool is used, the season, the user's body temperature, and the user's age.

[0071] The writing learning tool according to the present invention is preferably resistant to the influence of heat from the surface on which it is placed, so that the model can be quickly discolored by heat from fingers or the like. To make it less susceptible to the effects of heat from the ground surface, a heat insulating material (for example, a foaming agent) may be used as the base material, or a heat insulating material may be provided on the side of the base material opposite to the side on which the model is provided. Another example is to provide a raised area (for example, embossing) on ​​the part of the writing learning tool where the model is provided, so that the model does not come into contact with the ground.

[0072] The writing learning tool according to the present invention preferably has at least one of the following indication images provided inside or near a model selected from the group consisting of letters, numbers, and symbols: numbers corresponding to the stroke order of the model, an arrow indicating the direction of strokes, and finishing stroke information. Finishing strokes refers to the final action of writing a character, etc., and finishing stroke information includes "stops," "strokes," and "stroke-finishing strokes." This makes it easy to understand the order, direction, and finishing action of tracing the model, making it easier to learn how to write letters, numbers, symbols, etc. The image of the stroke information may be only the image of a character such as "stop," "stroke," or "stroke," but may also include an image of a symbol or figure. For example, if the stroke is a "stop," the image of the character "stop" and the image of the symbol "·" may be arranged side by side, and if the stroke is a "stroke," the image of the character "stroke" and the image of an arrow symbol may be arranged side by side.

[0073] The writing learning tool according to the present invention preferably has a related image associated with the model, selected from the group consisting of letters, numbers, symbols, figures, and pictures. For example, in a writing learning tool having a model provided on a base, the model and the related image associated with the model can be arranged side by side, i.e., the model and the related image associated with the model can be arranged on the same side of the base. The position of the related image associated with the model is not particularly limited, but it is preferably arranged near the model, and may be in any direction, up, down, left, or right. Furthermore, in a writing learning tool having a model provided on a base material, a related image relating to the model can be provided on the surface of the base material opposite to the side on which the model is provided. The related image associated with the example may be a reversible thermochromic image comprising a reversible thermochromic material, a non-thermochromic image comprising a non-thermochromic material, or an image comprising both a reversible thermochromic material and a non-thermochromic material.

[0074] A specific example of a writing learning sheet provided with related images related to a model is one in which the letter "a" is provided as a model on a base material, and the word "duck," the word "duck" (the English spelling of duck), a picture of a duck, or the like is provided next to the letter "a" as related images related to the model. It is generally said that learning how to read letters is more effective when learned by associating them with words or familiar objects than by memorizing single sounds, and by providing not only specific letters (models) but also words beginning with specific letters and pictures of those words (related images related to the model), the writing learning tool of the present invention not only allows students to learn how to write letters, but also how to read them at the same time, thereby promoting the development of language ability. Another example is a configuration in which the number "5" is provided as a model on a base material, and five dot symbols (·, dots) are provided on the opposite side of the base material as related images to the model. This type of writing learning sheet not only allows children to learn how to write and read numbers, but also allows them to recognize the quantities corresponding to numbers, thereby promoting the development of number sense.

[0075] The writing learning tool of the present invention may have a transparent glittering layer on the model to give the model a glittery appearance. This can increase preschool children's (toddlers') interest in letters and encourage them to learn letters. The glittering appearance of the model can also stimulate the user's visual sense and encourage them to learn letters. The transparent glossy layer is preferably a transparent glossy image that is an image having the same size and shape as the sample.

[0076] The transparent glossy layer can be formed as a coating layer on the sample by printing or applying a liquid composition containing a transparent metallic luster pigment onto the sample. Examples of methods for printing or applying a liquid composition containing a transparent metallic luster pigment include printing methods such as screen printing, offset printing, gravure printing, coater printing, and transfer printing, and application methods such as brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, and dip coating. The coating layer is formed by drying and solidifying a liquid composition, and is formed from components other than volatile components.

[0077] The transparent glitter layer may be a single-layer transparent glitter resin film formed by melt-blending a transparent metallic luster pigment into a transparent thermoplastic resin or a transparent thermosetting resin to prepare a molding resin composition such as pellets, powder, or paste, and molding the composition into a planar form such as a sheet or film by various molding methods such as extrusion molding, calendar molding, inflation molding, etc. Alternatively, the transparent glitter layer may be a laminated transparent glitter resin film formed as a coating layer on a transparent substrate by printing or applying a liquid composition containing the transparent metallic luster pigment onto the transparent substrate.

[0078] Examples of transparent metallic luster pigments include pigments in which the core material is natural mica, synthetic mica, glass pieces, alumina, transparent film pieces, or silicon oxide whose surface is coated with a metal oxide such as titanium oxide, and cholesteric liquid crystal pigments (e.g., the HELICONE HC series manufactured by Wacker Chemie). A transparent glossy layer using a transparent metallic luster pigment is preferable because it can also impart light resistance to the sample.

[0079] The transparent glitter layer may be a transparent glitter resin film having pearlescent properties and containing a translucent dye in a transparent multilayer film that exhibits a light interference phenomenon and has 10 or more layers made of polymers with different refractive indices as intermediate layers, such as BASF's product name: AURORA FILM. The film may also be a transparent photoluminescent resin film having holographic properties, which uses a relief hologram in which a transparent reflective layer is formed on the surface of a transparent hologram-forming layer having a fine uneven pattern, or a volume hologram. In addition, a transparent multilayer film with a thickness of 15 μm, in which the outermost layers on both sides are polypropylene layers and the inside is formed with 113 alternating layers of thin ethylene-vinyl acetate copolymer layers and thin polystyrene layers, and which has blue reflected light and green interference light; a transparent multilayer film with a thickness of 17 μm, in which the outermost layers on both sides are polypropylene layers and the inside is formed with 113 alternating layers of thin ethylene-vinyl acetate copolymer layers and thin polystyrene layers, and which has green reflected light and red interference light; a transparent multilayer film with a thickness of 17 μm, in which the outermost layers on both sides are polypropylene layers and the inside is formed with 113 alternating layers of thin ethylene-vinyl acetate copolymer layers and thin polystyrene layers, and which has A transparent multilayer film with a thickness of 28 μm, which has blue reflected light and green interference light, and in which 226 layers are alternately formed; a transparent multilayer film with a thickness of 31 μm, which has red reflected light and green interference light, and in which 226 layers of thin ethylene-vinyl acetate copolymer and thin polystyrene layers are alternately formed inside; a transparent multilayer film with a thickness of 15 μm, which has blue reflected light and green interference light, and in which 113 layers of thin polyester and polyolefin layers are alternately formed inside; A transparent multilayer film with a thickness of 17 μm, in which 113 layers of thin polyester and thin polyolefin layers are alternately formed inside, and having red reflected light and green interference light; a transparent multilayer film with a thickness of 15 μm, in which 113 layers of thin polyolefin and thin polyester layers are alternately formed inside, and having blue reflected light and green interference light; a transparent multilayer film with a thickness of 15 μm, in which 113 layers of thin polyolefin and thin polyester layers are alternately formed inside, and having red reflected light and green interference light; A transparent multilayer film with a thickness of 17 μm, the outermost layers on both sides being acrylic resin layers with 113 layers of thin polyester and acrylic resin layers alternately formed inside; a transparent multilayer film with a thickness of 15 μm, which has blue reflected light and green interference light, the outermost layers on both sides being acrylic resin layers with 113 layers of thin polyester and acrylic resin layers alternately formed inside; a transparent multilayer film with a thickness of 17 μm, which has red reflected light and green interference light, the outermost layers on both sides being acrylic resin layers with 113 layers of thin polyester and acrylic resin layers alternately formed inside;A 30μm thick transparent multilayer film with blue reflected light and green interference light, the outermost layers on both sides being acrylic resin layers with 113 alternating layers of thin polyester and acrylic resin layers formed inside; a 34μm thick transparent multilayer film with red reflected light and green interference light, the outermost layers on both sides being acrylic resin layers with 226 alternating layers of thin polyester and acrylic resin layers formed inside; a 28μm thick transparent multilayer film with blue reflected light and green interference light, the outermost layers on both sides being acrylic resin layers with 226 alternating layers of thin polyester and acrylic resin layers formed inside; The film may be a transparent photoluminescent resin film having iridescence, such as a 31 μm-thick transparent multilayer film having blue reflected light and green interference light, a 15 μm-thick transparent multilayer film having blue reflected light and green interference light, in which the outermost layers on the front and back are polyester layers and the interior is formed with 113 alternating layers of thin polyester layers and thin acrylic resin layers, or a 17 μm-thick transparent multilayer film having red reflected light and green interference light, in which the outermost layers on the front and back are polyester layers and the interior is formed with 113 alternating layers of thin polyester layers and thin acrylic resin layers, and examples thereof include IRIDESCENT FILM, manufactured by ENGELHARD. Alternatively, the film may be a transparent, photoluminescent resin film having a light-reflecting property, which has a structure in which multiple polyester thin films are stacked with their stretching axes shifted, such as a product name: Magical Film (Mirage Film) manufactured by Hologram Supply Co., Ltd.

[0080] The writing learning tool according to the present invention may have a layer containing a light stabilizer on the model for the purpose of imparting light resistance to the model. Examples of the light stabilizer include an ultraviolet absorber, an antioxidant, an antiaging agent, a singlet oxygen quencher, a superoxide anion quencher, an ozone quencher, a visible light absorber, and an infrared absorber.

[0081] The writing learning tool of the present invention may be designed so that the thickness of the model is increased or the model itself is provided with irregularities in order to enhance the tactile sensation when tracing the model. As a result, when the user of the writing learning tool traces the model, the user's vision is stimulated by changes in color or at least one of the size and shape of the model itself, and the irregularities stimulate the user's tactile sensation, thereby promoting the acquisition of letters, etc., through a synergistic effect of vision and touch. One method for providing irregularities to the model is, for example, to apply a graining finish to the model.

[0082] The writing learning tool according to the present invention may be provided with a transparent protective layer for the purpose of protecting the model provided on the base material from scratches and dirt. The transparent protective layer can be formed by printing or applying a solution containing a resin or a resin emulsion onto the sample, or by adhering a plastic, elastomer, rubber, or the like in the form of a flat surface, sheet, film, or the like. The transparent protective layer can be provided by a conventional lamination process, such as dry lamination or hot melt lamination, or by interposing a heat-sealing film between the transparent protective layer and the adjacent sample and then heat-pressing the two together. The transparent protective layer is preferably provided at least on the model, but is preferably provided on the entire surface of the base material, which makes it possible to impart durability to the writing learning tool itself. The transparent glossy layer may also serve as the transparent protective layer, or a transparent protective layer may be further provided on the transparent glossy layer provided on the sample.

[0083] In the present invention, transparency refers to the property of transmitting light with wavelengths in the visible light region (the wavelength region of 380 to 780 nm as defined by JIS B 7079), and the light transmittance (visible light transmittance) in the visible light region of the transparent glittering layer and the transparent protective layer is preferably 5% or more, more preferably 10% or more, and even more preferably 20% or more. If the visible light transmittance is less than 5%, it becomes difficult to visually recognize adjacent examples. The above visible light transmittance is the midpoint between the maximum and minimum values ​​when a transparent glossy layer or transparent protective layer is provided on a transparent substrate that transmits light with wavelengths in the visible light region, and measured in the wavelength region from 380 nm to 780 nm using a spectrophotometer (manufactured by Hitachi, Ltd., product name: U-3210).

[0084] The shape of the writing learning tool according to the present invention is not particularly limited. For example, it may be a three-dimensional shape or a sheet shape (flat shape). A sheet shape is preferable from the viewpoint of ease of tracing with a finger or the like. Hereinafter, a sheet-shaped writing learning tool may be referred to as a "writing learning sheet" or "sheet."

[0085] The writing learning tool according to the present invention is preferably in card form, which is smaller than sheet form, so that it is easier for preschool children (toddlers) to hold and carry. Hereinafter, card-form writing learning tools may be referred to as "writing learning cards" or "cards." The writing learning tool may be a single sheet (card) or may consist of multiple sheets (cards). When it consists of multiple sheets (cards), by selecting only the sheets (cards) that contain characters that the child has not yet mastered, the child can efficiently learn how to write specific characters. It is preferable to round the four corners of the sheet (card) in order to ensure safety when handling the sheet (card).

[0086] The writing learning tool according to the present invention is preferably in the form of a booklet. A booklet form is a form in which a plurality of pages (sheets) are bound together. The booklet form may be one that uses only the sheet (card) form of the writing learning tool, or may be one that combines the sheet (card) form of the writing learning tool with a front cover, a back cover, a sheet provided with only a non-thermochromic image, or the like.

[0087] A booklet-type writing learning tool can be obtained by forming holes in one or more places on multiple sheets (cards) and binding them together by passing a string or a ring-shaped fastener through the holes. By using an openable fastener, desired sheets (cards) can be selected from multiple sheets (cards) and bound together, so that writing can be efficiently learned by focusing on specific characters, etc., regardless of location. Alternatively, a booklet-shaped writing learning tool can be obtained by using a clip, a thread, a wire, an adhesive, or by heat fusion using a hot melt adhesive.

[0088] Examples of booklet-type writing learning tools include picture books, workbooks (drills), and notebooks. Booklet-type writing learning tools may be opened vertically or horizontally.

[0089] The writing learning tool according to the present invention is suitable as a teaching tool, educational tool, or educational toy for learning how to write letters, numbers, symbols, etc. and the order in which they are written. [Example]

[0090] Examples are given below, but the present invention is not limited thereto. In the examples, "parts" means "parts by mass."

[0091] Example 1 Preparation of reversible thermochromic material A (reversible thermochromic microencapsulated pigment A) A reversible thermochromic composition consisting of 1.5 parts of 3-(4-diethylamino-2-hexyloxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide as component (A), 5 parts of 1,1-bis(4-hydroxyphenyl)n-decane as component (B), and 40 parts of 2-ethylhexyl behenate and 10 parts of n-butyl stearate as component (C) was heated and dissolved uniformly, and encapsulated in microcapsules by interfacial polymerization to prepare a microcapsule dispersion. Reversible thermochromic microcapsule pigment A was obtained from the above microcapsule dispersion by centrifugation. Microcapsule pigment A had a complete color development temperature t1 of 26°C, a color development start temperature t2 of 29°C, a color disappearance start temperature t3 of 26°C, a complete disappearance temperature t4 of 31°C, t2-t1 of 3°C, t4-t3 of 5°C, and ΔH of 1°C, and reversibly changed from blue to colorless with temperature change.

[0092] Creation of writing learning tools (writing learning sheets) (see Figures 2 to 4) A reversible thermochromic ink was prepared by uniformly dispersing 30 parts of microcapsule pigment A as a reversible thermochromic material, 62 parts of a urethane emulsion, 2 parts of a thickener, 0.5 parts of a leveling agent, 0.5 parts of an antifoaming agent, 5 parts of a crosslinking agent, and 0.2 parts of a pink general pigment. The above-mentioned reversible thermochromic ink was screen printed on one side of a white high-quality paper substrate (3), and the ink was dried and hardened to form the character "a" (reversible thermochromic image (2') that reversibly changes color from one color to another). Next, screen printing was carried out using black non-thermochromic ink, which was then dried and hardened to form, near the reversible thermochromic image, images (instruction images) of numbers corresponding to the stroke order, arrows indicating the direction of strokes, and stroke completion information ('stops' and 'strokes'). Next, a 16 μm thick transparent PET film with an adhesive layer was attached to the entire surface of the substrate on which the model was to be placed (the side of the substrate opposite the side of the model on which the substrate was to be placed) via the adhesive layer, and laminated to form a transparent protective layer (4), thereby producing a writing learning tool (1) [writing learning sheet (1')].

[0093] Because the reversible thermochromic material on the writing learning sheet is in a colored state at room temperature (temperature range of 15 to 25°C), the model (letter "a") was purple (first color) that was a mixture of blue from the reversible thermochromic material and pink from the general pigment (initial state, see Figure 2). When the model was traced with a finger, the heat of the finger (body temperature) caused the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the material to decolorize, and the traced area of ​​the model turned pink (second color) due to the general pigment (see Figure 3). When this writing study sheet was used, the traced area changed color from one color (first color) to a different color (second color) when the user traced the model with their finger, stimulating the user's visual sense and allowing the user to learn how to write the characters with a sense of reality. Furthermore, numbers corresponding to the stroke order, arrows indicating the direction of strokes, and images of stroke information (instruction images) were placed near the characters (model), allowing the user to accurately learn how to write the characters and the order in which to write them. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. When the application of heat (body heat) to the model was removed, the reversible thermochromic material reached its full color-changing temperature t1, and the model returned to its initial purple color (first color). This allowed for repeated use, making it useful as a teaching tool or educational toy. Furthermore, because the t2-t1 and t4-t3 temperatures of the reversible thermochromic material were below 5°C and the ΔH was 1°C, the color change of the model was rapid.

[0094] Example 2 Preparation of reversible thermochromic material B (reversible thermochromic microencapsulated pigment B) A reversible thermochromic composition consisting of 5 parts of 2-(2-chloroanilino)-6-di-n-butylaminofluoran as component (A), 8 parts of 1,1-bis(4-hydroxyphenyl)n-decane as component (B), and 40 parts of stearyl decanoate, 5 parts of stearyl laurate, and 5 parts of decyl decanoate as component (C) was uniformly heated and dissolved, and the mixture was encapsulated in microcapsules by interfacial polymerization to prepare a microcapsule dispersion. Reversible thermochromic microcapsule pigment B was obtained from the above microcapsule dispersion by centrifugation. Microcapsule pigment B had a complete color development temperature t1 of 28°C, a color development start temperature t2 of 30°C, a color disappearance start temperature t3 of 29°C, a complete disappearance temperature t4 of 35°C, t2-t1 of 2°C, t4-t3 of 6°C, and ΔH of 3°C, and reversibly changed from black to colorless with temperature change.

[0095] Creation of writing learning tools (writing learning sheets) (see Figures 5 and 6) A reversible thermochromic ink was prepared by uniformly dispersing 30 parts of microcapsule pigment B as a reversible thermochromic material, 62 parts of urethane emulsion, 2 parts of thickener, 0.5 parts of leveling agent, 0.5 parts of antifoaming agent, and 5 parts of crosslinking agent. The letters "I" and "i" were screen printed on one side of white high-quality paper as the substrate (3) using pink non-thermochromic ink and dried and cured to form the non-thermochromic image (2"'). The reversible thermochromic ink was then screen printed on the non-thermochromic image and dried and cured to form the letters "I" and "i" which are reversible thermochromic images (2") that reversibly change color from colored to colorless, forming the letters "I" and "i" which are model (2). The non-thermochromic image and the reversible thermochromic image that reversibly change color from colored to colorless are identical in shape and size, and the model letters "I" and "i" are visible in the writing learning tool as reversible thermochromic images (2') that reversibly change color from colored to a different color. Next, black non-thermochromic ink was used for screen printing, which was then dried and hardened to form, near the model, images of numbers corresponding to the stroke order and arrows indicating the stroke direction (instruction images). Next, a 16 μm thick transparent PET film having an adhesive layer was attached to the entire surface of the side of the substrate on which the sample was to be placed (the side of the sample opposite to the side on which the substrate was to be placed) via the adhesive layer, and a lamination process was performed to form a transparent protective layer (4). Next, an adhesive layer (5) was provided on the other side of the substrate (the side of the substrate opposite to the side on which the model was provided), and a polyolefin foam sheet (insulating sheet) was further provided as a heat insulating material (6) on the side of the adhesive layer opposite to the side on which the substrate was provided, thereby producing a writing learning tool (1) [writing learning sheet (1')].

[0096] Because the reversible thermochromic material in the writing learning sheet is in a colored state at room temperature (temperature range of 15 to 25°C), the model (letters "I" and "i") was black (first color) that was a mixture of the black color from the reversible thermochromic material and the pink color from the general pigment (initial state). When the model was traced with a finger, the heat of the finger (body temperature) caused the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the reversible thermochromic material to decolorize, and the traced area of ​​the model turned pink (second color) due to the general pigment. When the user traces the model with his / her finger, the traced area changes color from a color (first color) to a different color (second color), stimulating the user's visual sense, allowing the user to learn how to write the character with a sense of actual writing. In addition, the image of the number corresponding to the stroke order and the arrow indicating the stroke direction (instruction image) are displayed on the character (model). ) placed near the model, the user was able to accurately learn the stroke order of the characters. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. When heat (body heat) is no longer applied to the model, the reversible thermochromic material reaches its full color-changing temperature t1, the material changes color, and the model returns to its initial black state (first color).This means that the model can be used repeatedly and is useful as a teaching tool or educational toy. The writing learning sheet has heat insulating material on the contact surface and is less susceptible to heat from the contact surface, so the color of the example changes quickly when traced with a finger.

[0097] Example 3 Preparation of reversible thermochromic material C (reversible thermochromic microcapsule pigment C) A reversible thermochromic composition consisting of 1 part of 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide as component (A), 6 parts of 1,1-bis(4-hydroxyphenyl)n-decane as component (B), and 45 parts of stearyl decanoate and 5 parts of stearyl laurate as component (C) was heated and dissolved uniformly, and encapsulated in microcapsules by interfacial polymerization to prepare a microcapsule dispersion. Reversible thermochromic microcapsule pigment C was obtained from the above microcapsule dispersion by centrifugation. Microcapsule pigment C had a complete color development temperature t1 of 29°C, a color development start temperature t2 of 33°C, a color disappearance start temperature t3 of 30°C, a complete disappearance temperature t4 of 36°C, t2-t1 of 4°C, t4-t3 of 6°C, and ΔH of 2°C, and reversibly changed from blue to colorless with temperature change.

[0098] Creation of writing learning tools (writing learning sheets) (see Figures 7 and 8) A reversible thermochromic ink was prepared by uniformly dispersing 30 parts of microcapsule pigment C as a reversible thermochromic material, 62 parts of a urethane emulsion, 2 parts of a thickener, 0.5 parts of a leveling agent, 0.5 parts of an antifoaming agent, 5 parts of a crosslinking agent, and 0.2 parts of a yellow general pigment. The above-mentioned reversible thermochromic ink was screen printed on one side of a white high-quality paper substrate (3), and the ink was dried and cured to form the number "5" (reversible thermochromic image (2') that reversibly changes color from one color to a different color), which is the model (2). Next, black non-thermochromic ink was used for screen printing, which was then dried and hardened to form, near the model, images of numbers corresponding to the stroke order and arrows indicating the stroke direction (instruction images). Next, the other side of the substrate (the side of the substrate opposite to the side on which the example was placed) was screen printed using red non-discoloring ink, which was then dried and hardened to form five pictures of apples as related images (7) associated with the example. Next, a 16 μm thick transparent PET film with an adhesive layer was attached to the entire surface of both sides of the substrate (the side of the model opposite to the side on which the substrate is provided, and the side of the related image related to the model opposite to the side on which the substrate is provided), and laminated to form a transparent protective layer (4), thereby producing a writing learning tool (1) [writing learning sheet (1')]. This writing learning sheet has a structure in which a model is provided on one side (front side) of a base material, and a related image related to the non-thermochromic model is provided on the other side (back side) of the base material.

[0099] In the writing learning sheet, the reversible thermochromic material is in a colored state at room temperature (temperature range of 15 to 25°C), so the model (number "5") was green (first color) (initial state) that was a mixture of blue from the reversible thermochromic material and yellow from the general pigment. When the sample was traced with the finger, the heat of the finger (body temperature) caused the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the material to decolorize, and the reversible thermochromic image of the traced area turned yellow (second color) due to the general pigment. When this writing study sheet was used, the traced area changed color from one color (first color) to a different color (second color) when the user traced the model with their finger, stimulating the user's visual sense and allowing the user to learn how to write numbers with a sense of reality. Furthermore, the numbers corresponding to the stroke order and arrows indicating the stroke direction (instruction images) were placed near the numbers (model), allowing the user to accurately learn the stroke order of the numbers. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. In addition, after learning how to write and read numbers on the front side of the writing learning sheet, by turning the sheet over, children could see pictures of five apples (images related to the model), which not only allowed them to learn how to write or read numbers, but also helped them recognize the quantities corresponding to the numbers, promoting the development of number sense. When the application of heat (body temperature) to the model is stopped, the reversible thermochromic material reaches its full color-changing temperature t1, and the reversible thermochromic material changes color, returning the model to its initial purple color (first color).This means that the model can be used repeatedly and is useful as a teaching tool or educational toy.

[0100] Example 4 Preparation of reversible thermochromic material D (reversible thermochromic microcapsule pigment D) A reversible thermochromic composition consisting of 1.5 parts of 3-(4-diethylamino-2-hexyloxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide as component (A), 5 parts of 1,1-bis(4-hydroxyphenyl)n-decane as component (B), and 40 parts of 2-ethylhexyl behenate and 10 parts of 2-methylpentyl behenate as component (C) was heated and dissolved uniformly, and encapsulated in microcapsules by interfacial polymerization to prepare a microcapsule dispersion. Reversible thermochromic microcapsule pigment D was obtained from the above microcapsule dispersion by centrifugation. Microcapsule pigment D had a complete color development temperature t1 of 28°C, a color development start temperature t2 of 31°C, a color disappearance start temperature t3 of 28°C, a complete disappearance temperature t4 of 33°C, t2-t1 of 3°C, t4-t3 of 5°C, and ΔH of 1°C, and reversibly changed from blue to colorless with temperature change.

[0101] Creation of writing learning tools (writing learning sheets) (see Figures 9 and 10) A reversible thermochromic ink was prepared by uniformly dispersing 30 parts of microcapsule pigment D as a reversible thermochromic material, 62 parts of a urethane emulsion, 2 parts of a thickener, 0.5 parts of a leveling agent, 0.5 parts of an antifoaming agent, 5 parts of a crosslinking agent, and 0.2 parts of a pink general pigment. The reversible thermochromic ink was screen printed on one side of a white wood-free paper substrate (3), and then dried and cured to form the symbol "￥" (reversible thermochromic image (2') that reversibly changes color from one color to another). This symbol was then embossed. Next, black non-thermochromic ink was used for screen printing, which was then dried and hardened to form, near the model, images of numbers corresponding to the stroke order and arrows indicating the stroke direction (instruction images). Next, a 16 μm thick transparent PET film with an adhesive layer was attached to the entire surface of the substrate on which the model was to be placed (the side of the substrate opposite the side of the model on which the substrate was to be placed) via the adhesive layer, and laminated to form a transparent protective layer (4), thereby producing a writing learning tool (1) [writing learning sheet (1')].

[0102] In the writing learning sheet, the reversible thermochromic material is in a colored state at room temperature (temperature range of 15 to 25°C), so the model (symbol "￥") was purple (first color) (initial state), a mixture of blue from the reversible thermochromic material and pink from the general pigment. When the model was traced with a finger, the heat of the finger (body temperature) caused the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the reversible thermochromic material to decolorize, and the traced area of ​​the model turned pink (second color) due to the general pigment. When this writing study sheet was used, the traced area changed color from one color (first color) to a different color (second color) when the user traced the model with their finger, stimulating the user's visual sense and allowing the user to learn how to write the symbols with a sense of actual writing. Furthermore, numbers corresponding to the stroke order and arrows indicating the direction of strokes (instruction images) were placed near the symbols (model), allowing the user to accurately learn the stroke order of the symbols. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. The model on the writing learning sheet is embossed to create a textured surface, and when the user traces the model, the color of the model itself changes to stimulate the user's vision, and the texture also stimulates the user's sense of touch, so the synergistic effect of vision and touch can encourage the user to learn symbols. When the application of heat (body heat) to the model was removed, the reversible thermochromic material reached its full color-changing temperature t1, and the model returned to its initial purple color (first color). This made the model reusable and useful as a teaching tool or educational toy. Furthermore, the t2-t1 and t4-t3 temperatures of the reversible thermochromic material were below 5°C, and the ΔH was 1°C, so the color change of the model was rapid.

[0103] Example 5 Preparation of reversible thermochromic material E (reversible thermochromic microencapsulated pigment E) A reversible thermochromic composition consisting of 1 part of 6-(N-ethyl-N-isopentylamino)-1,2-benzofluoran as component (A), 5 parts of 1,1-bis(4-hydroxyphenyl)-2-ethylhexane as component (B), and 25 parts of 2-ethylhexyl behenate and 25 parts of 2-methylpentyl behenate as component (C) was heated and dissolved uniformly, and encapsulated in microcapsules by interfacial polymerization to prepare a microcapsule dispersion. Reversible thermochromic microcapsule pigment E was obtained from the above microcapsule dispersion by centrifugation. Microcapsule pigment E had a complete color development temperature t1 of 27°C, a color development start temperature t2 of 30°C, a color disappearance start temperature t3 of 29°C, a complete disappearance temperature t4 of 31°C, t2-t1 of 3°C, t4-t3 of 2°C, and ΔH of 1.5°C, and reversibly changed from pink to colorless with temperature change.

[0104] Creation of writing learning tools (writing learning sheets) (see Figure 11) A reversible thermochromic ink was prepared by uniformly dispersing 30 parts of microcapsule pigment E as a reversible thermochromic material, 62 parts of a urethane emulsion, 2 parts of a thickener, 0.5 parts of a leveling agent, 0.5 parts of an antifoaming agent, 5 parts of a crosslinking agent, and 0.2 parts of a blue general pigment. The above-mentioned reversible thermochromic ink was screen printed on one side of a white high-quality paper substrate (3), and the ink was dried and hardened to form the character "a" (reversible thermochromic image (2') that reversibly changes color from one color to another). Next, black non-thermochromic ink was used for screen printing, which was then dried and hardened to form, near the model, numbers corresponding to the stroke order, arrows indicating the direction of strokes, and images (indicative images) of stroke-finishing information ("stops" and "strokes"), as well as the word "duck" and a picture of a duck as related images (7) related to the model. Next, a 16 μm thick transparent PET film with an adhesive layer was attached to the entire surface of the side of the substrate where the model and related images related to the model were to be placed (the side opposite the side where the model and related images related to the model were to be placed on the substrate), and laminated to form a transparent protective layer, thereby producing a writing learning tool (1) [writing learning sheet (1')]. This writing learning sheet has a model (letters) on one side of a base material, and related images (words and pictures) related to the non-thermochromic model, with the model and the related images related to the model arranged side by side.

[0105] Because the reversible thermochromic material in the writing learning sheet is in a colored state at room temperature (temperature range of 15 to 25°C), the model (letter "a") was purple (first color) (initial state) which was a mixture of the pink color from the reversible thermochromic material and the blue color from the general pigment. When the model was traced with a finger, the heat of the finger (body temperature) caused the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the reversible thermochromic material to decolorize, and the traced area of ​​the model turned blue (second color) due to the general pigment. When this writing study sheet was used, the traced area changed color from one color (first color) to a different color (second color) when the user traced the model with their finger, stimulating the user's visual sense and allowing the user to learn how to write the character with a sense of reality. Furthermore, numbers corresponding to the stroke order, arrows indicating the direction of strokes, and images of stroke information (instruction images) were placed near the character (model), allowing the user to accurately learn how to write the character and the order in which to write it. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. In addition, the writing learning sheets have related images (words and pictures) placed near the examples, allowing students to learn how to read specific characters by associating them with the words and pictures.This means that students can learn the stroke order and reading of characters at the same time, which promotes the development of language skills. When the application of heat (body heat) to the model was removed, the reversible thermochromic material reached its full color-changing temperature t1, and the model returned to its initial purple color (first color). This made the model reusable and useful as a teaching tool or educational toy. Furthermore, the t2-t1 and t4-t3 temperatures of the reversible thermochromic material were below 3°C, and the ΔH was 1.5°C, so the color change of the model was rapid.

[0106] Example 6 Creation of writing learning tools (writing learning sheets) (see Figures 12 and 13) A reversible thermochromic ink was prepared by uniformly dispersing 30 parts of microcapsule pigment B as a reversible thermochromic material, 62 parts of a urethane emulsion, 2 parts of a thickener, 0.5 parts of a leveling agent, 0.5 parts of an antifoaming agent, 5 parts of a crosslinking agent, and 0.2 parts of a pink general pigment. In addition, a metallic luster ink was prepared by uniformly mixing 10 parts of a transparent metallic luster pigment (Merck Co., Ltd., product name: Iriodin 205 (average particle size: 10-60 μm, color: rutile platinum gold)) in which the surface of natural mica is coated with titanium oxide, into a vehicle consisting of 100 parts of a 50% acrylic resin xylene solution, 1 part antifoaming agent, 40 parts xylene, and 40 parts methyl isobutyl ketone. The reversible thermochromic ink was screen printed on one side of a sheet of white wood-free paper (3), and then dried and cured to form the letter "A" (model (2) [reversible thermochromic image (2') that reversibly changes color from a colored to a different color]). The metallic luster ink was then screen printed on the model, and then dried and cured to form the letter "A" (transparent lustrous layer, 8). The model and the transparent lustrous image are identical in shape and size, and the letter "A" is visible on the writing study sheet as the reversible thermochromic image (2') that reversibly changes color from a lustrous colored to a different color. Next, black non-thermochromic ink was used for screen printing, which was then dried and hardened to form, near the model, images of numbers corresponding to the stroke order and arrows indicating the stroke direction (instruction images). Next, a 16 μm thick transparent PET film having an adhesive layer was attached to the entire surface of the substrate on the side where the transparent glossy layer was to be provided (the side of the transparent glossy layer opposite the side where the substrate was to be provided) via the adhesive layer, and laminated to form a transparent protective layer (4), thereby producing a writing learning tool (1) [writing learning sheet (1')].

[0107] At room temperature (temperature range of 15 to 25°C), the reversible thermochromic material of the writing learning sheet is in a colored state, and the black color from the reversible thermochromic material and the pink color from the general pigment are mixed together, but because a transparent lustrous layer (transparent lustrous image) is placed on the model, the model (letter "A") is yellow with a metallic luster (metallic yellow) (first color) (initial state). When the model was traced with a finger, the heat of the finger (body temperature) caused the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the reversible thermochromic material to decolorize, and the traced area of ​​the model turned pink (second color) due to the general pigment. When this writing study sheet was used, the traced area changed color from a luminous color (first color) to a different color (second color) when the user traced the model with their finger. This stimulated the user's visual sense, allowing them to learn how to write the characters while experiencing the sensation of actually writing. Furthermore, numbers corresponding to the stroke order and arrows indicating the direction of strokes (instruction images) were placed near the characters (model), allowing users to accurately learn the stroke order of the characters. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. The writing learning sheet has a transparent luminous layer (transparent luminous image) on the model, which gives the letters a luminous quality, which can stimulate preschool children's (toddlers') interest in letters and lead them to learn letters. Furthermore, the luminous feel of the letters stimulates the user's vision and encourages them to learn letters. When the application of heat (body temperature) to the model is stopped, the reversible thermochromic material reaches its full color-changing temperature t1 and enters a colored state, returning the model to its initial metallic luster yellow color (first color).This means that the model can be used repeatedly and is useful as a teaching tool or educational toy.

[0108] Example 7 Preparation of reversible thermochromic material F (reversible thermochromic microencapsulated pigment F) A reversible thermochromic composition consisting of 1.25 parts of 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide as component (A), 5 parts of 1,1-bis(4-hydroxyphenyl)n-decane as component (B), and 30 parts of 2-ethylhexyl behenate and 20 parts of n-butyl stearate as component (C) was heated and dissolved uniformly, and encapsulated in microcapsules by interfacial polymerization to prepare a microcapsule dispersion. Reversible thermochromic microcapsule pigment F was obtained from the above microcapsule dispersion by centrifugation. Microcapsule pigment F had a complete color development temperature t1 of 24°C, a color development start temperature t2 of 28°C, a color disappearance start temperature t3 of 25°C, a complete disappearance temperature t4 of 29°C, t2-t1 of 4°C, t4-t3 of 4°C, and ΔH of 1°C, and reversibly changed from blue to colorless with temperature change.

[0109] Creation of writing learning tools (writing learning sheets) (see Figure 14) A reversible thermochromic ink was prepared by uniformly dispersing 30 parts of microcapsule pigment F as a reversible thermochromic material, 62 parts of urethane emulsion, 2 parts of thickener, 0.5 parts of leveling agent, 0.5 parts of antifoaming agent, and 5 parts of crosslinking agent. A blue non-thermochromic ink was screen printed on one side of a white high-quality paper substrate (3), and the ink was dried and cured to form a dotted letter "a" that is a non-thermochromic image (2"'). Next, the reversible thermochromic ink was screen printed on the non-thermochromic image, and the ink was dried and cured to form a reversible thermochromic image (2") that reversibly changes color from colored to colorless, forming the letter "a" that is the model (2). The size of the non-thermochromic image is smaller than that of the reversible thermochromic image that reversibly changes color from colored to colorless, and the non-thermochromic image is included in the reversible thermochromic image that reversibly changes color from colored to colorless. The letter "a" that is the model in the writing learning tool is composed of a layered structure of a non-thermochromic image and a reversible thermochromic image that reversibly changes color from colored to colorless. Next, black, non-thermochromic ink was used for screen printing, which was then dried and hardened to form, near the model, images (instruction images) of numbers corresponding to the stroke order, arrows indicating the direction of strokes, and information on finishing strokes ('stops' and 'strokes'). Next, a 16 μm thick transparent PET film with an adhesive layer was attached to the entire surface of the substrate on which the model was to be placed (the side of the substrate opposite the side of the model on which the substrate was to be placed) via the adhesive layer, and laminated to form a transparent protective layer (4), thereby producing a writing learning tool (1) [writing learning sheet (1')].

[0110] The writing learning sheet contains a reversible thermochromic material that is in a colored state at room temperature (15 to 25°C), so the model (letter "a") was blue due to the reversible thermochromic material (initial state, see Figure 14, left). When the model was traced with a finger, the heat of the finger (body temperature) caused the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the reversible thermochromic material to decolorize, and the traced area of ​​the model turned into a blue dotted letter "a" made of non-thermochromic material (see Figure 14, right). When the user traces the model with their finger, the size and shape of the traced part of the model changes, stimulating the user's visual sense, allowing them to learn how to write the characters with a sense of reality. Furthermore, numbers corresponding to the stroke order, arrows indicating the direction of the stroke, and images of stroke information (instruction images) are placed near the character (model), allowing users to accurately learn how to write the characters and the stroke order. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. When the application of heat (body heat) to the model is removed, the reversible thermochromic material reaches its full color-changing temperature t1, and the reversible thermochromic material returns to its colored state, returning the model to its original state. This makes it possible to reuse the model, making it useful as a teaching tool or educational toy. In addition, the reversible thermochromic material's t2-t1 and t4-t3 are below 5°C, and ΔH is 1°C, so the color change of the model is rapid.

[0111] Example 8 Preparation of reversible thermochromic material G (reversible thermochromic microencapsulated pigment G) A reversible thermochromic composition consisting of 1.25 parts of 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide as component (A), 5 parts of 1,1-bis(4-hydroxyphenyl)n-decane as component (B), and 40 parts of 2-ethylhexyl behenate and 10 parts of n-butyl stearate as component (C) was heated and dissolved uniformly, and encapsulated in microcapsules by interfacial polymerization to prepare a microcapsule dispersion. Reversible thermochromic microcapsule pigment G was obtained from the above microcapsule dispersion by centrifugation. Microcapsule pigment G had a complete color development temperature t1 of 26°C, a color development start temperature t2 of 30°C, a color disappearance start temperature t3 of 27°C, a complete disappearance temperature t4 of 31°C, t2-t1 of 4°C, t4-t3 of 4°C, and ΔH of 1°C, and reversibly changed from blue to colorless with temperature change.

[0112] Creation of writing learning tools (writing learning sheets) (see Figures 15 and 16) A reversible thermochromic ink was prepared by uniformly dispersing 30 parts of microcapsule pigment G as a reversible thermochromic material, 62 parts of urethane emulsion, 2 parts of thickener, 0.5 parts of leveling agent, 0.5 parts of antifoaming agent, and 5 parts of crosslinking agent. The above-mentioned reversible thermochromic ink was screen printed on one side of white high-quality paper as the substrate (3), and dried and cured to form the letter "A," which is a reversible thermochromic image (2") that reversibly changes color from colored to colorless. Next, blue non-thermochromic ink was screen printed around the reversible thermochromic image, and dried and cured to form a non-thermochromic image (2"), forming the letter "A" as the model (2). The model letter "A" in the writing learning tool is composed of a non-thermochromic image and a reversible thermochromic image that reversibly changes color from colored to colorless, arranged side by side. Next, black non-thermochromic ink was used for screen printing, which was then dried and hardened to form, near the model, images of numbers corresponding to the stroke order and arrows indicating the stroke direction (instruction images). Next, a 16 μm thick transparent PET film with an adhesive layer was attached to the entire surface of the side of the substrate where the model was to be placed (the side of the substrate opposite to the side where the model was to be placed) via the adhesive layer, and laminated to form a transparent protective layer (4), thereby producing a writing learning tool (1) [writing learning sheet (1')].

[0113] In the writing learning sheet, the reversible thermochromic material is in a colored state at room temperature (temperature range of 15 to 25°C), so the model (letter "A") was blue, consisting of a non-thermochromic image and a reversible thermochromic image that reversibly changes color from colored to colorless (initial state, see the left diagram in Figure 15). When the model was traced with a finger, the heat of the finger (body temperature) caused the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the reversible thermochromic material to decolorize, and the traced area of ​​the model became the white letter "A" outlined in blue by the non-thermochromic image (see Figure 15, right). When this writing study sheet was used, the shape of the model changed as the user traced the part they had traced, stimulating the user's visual sense and allowing them to learn how to write the characters with a sense of reality. Furthermore, numbers corresponding to the stroke order and arrows indicating the direction of strokes (instruction images) were placed near the characters (model), allowing users to accurately learn how to write the characters and the stroke order. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. When the application of heat (body heat) to the model is removed, the reversible thermochromic material reaches its full color-changing temperature t1, and the reversible thermochromic material returns to its colored state, returning the model to its original state. This makes it possible to reuse the model, making it useful as a teaching tool or educational toy. In addition, the reversible thermochromic material's t2-t1 and t4-t3 are below 5°C, and ΔH is 1°C, so the color change of the model is rapid.

[0114] Example 9 Creation of writing learning tools (writing learning sheets) (see Figure 17) A reversible thermochromic ink was prepared by uniformly dispersing 30 parts of microcapsule pigment G as a reversible thermochromic material, 62 parts of a urethane emulsion, 2 parts of a thickener, 0.5 parts of a leveling agent, 0.5 parts of an antifoaming agent, 5 parts of a crosslinking agent, and 0.2 parts of a pink general pigment. A blue non-thermochromic ink was screen printed on one side of a white high-quality paper substrate (3), and the ink was dried and cured to form a dashed line number "5" which is a non-thermochromic image (2"'). Next, the reversible thermochromic ink was screen printed on the same surface, and the ink was dried and cured to form a reversible thermochromic image (2") which reversibly changes color from colored to colorless between the dashed lines of the non-thermochromic image and in contact with the dashed lines of the non-thermochromic image, thereby forming the model number "5." The model number "5" in the writing learning tool is configured so that a non-thermochromic image and a reversible thermochromic image which reversibly changes color from colored to colorless are arranged side by side. Next, black non-thermochromic ink was used for screen printing, which was then dried and hardened to form, near the model, images of numbers corresponding to the stroke order and arrows indicating the stroke direction (instruction images). Next, a 16 μm thick transparent PET film with an adhesive layer was attached to the entire surface of the side of the substrate where the model was to be placed (the side of the substrate opposite to the side where the model was to be placed) via the adhesive layer, and laminated to form a transparent protective layer (4), thereby producing a writing learning tool (1) [writing learning sheet (1')].

[0115] In the writing learning sheet, the reversible thermochromic material is in a colored state at room temperature (temperature range of 15 to 25°C), so the model (number "5") was blue, with both the non-thermochromic image and the reversible thermochromic image, which reversibly changes color from colored to colorless, combined (initial state, see the left diagram in Figure 17). When the model is traced with a finger, the heat of the finger (body temperature) causes the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the reversible thermochromic material to decolorize, and the traced area of ​​the model becomes a non-thermochromic image of the number "5" in dashed blue lines (see Figure 17, right). When this writing study sheet was traced with the user's finger, the shape of the model changed as the user traced, stimulating the user's visual sense, allowing the user to learn how to write numbers with a sense of reality. Furthermore, images of numbers corresponding to the stroke order and arrows indicating the direction of stroke (instruction images) were placed near the numbers (model), allowing the user to accurately learn how to write the numbers and the stroke order. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. When the application of heat (body heat) to the model is removed, the reversible thermochromic material reaches its full color-changing temperature t1, and the reversible thermochromic material returns to its colored state, returning the model to its original state. This makes it possible to reuse the model, making it useful as a teaching tool or educational toy. In addition, the reversible thermochromic material's t2-t1 and t4-t3 are below 5°C, and ΔH is 1°C, so the color change of the model is rapid.

[0116] Example 10 Preparation of reversible thermochromic material H (reversible thermochromic microcapsule pigment H) A reversible thermochromic composition consisting of 1.5 parts of 3-[2-ethoxy-4-(N-ethylanilino)phenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide as component (A), 8 parts of 1,1-bis(4-hydroxyphenyl)-2-ethylhexane as component (B), and 30 parts of cetyl caprate and 20 parts of stearyl caprate as component (C) was uniformly heated and dissolved, and the mixture was encapsulated in microcapsules by interfacial polymerization to prepare a microcapsule dispersion. Reversible thermochromic microcapsule pigment H was obtained from the above microcapsule dispersion by centrifugation. Microcapsule pigment H had a complete color development temperature t1 of 19°C, a color development start temperature t2 of 28°C, a color disappearance start temperature t3 of 21°C, a complete disappearance temperature t4 of 31°C, t2-t1 of 9°C, t4-t3 of 10°C, and ΔH of 2.5°C, and reversibly changed from blue to colorless with temperature change.

[0117] Creation of writing learning tools (see Figures 18 and 19) A reversible thermochromic ink was prepared by uniformly dispersing 30 parts of microcapsule pigment H as a reversible thermochromic material, 62 parts of a urethane emulsion, 2 parts of a thickener, 0.5 parts of a leveling agent, 0.5 parts of an antifoaming agent, 5 parts of a crosslinking agent, and 0.2 parts of a pink general pigment. The ink changes color from one color to another. The above-mentioned reversible thermochromic ink was screen printed on one side of a white high-quality paper substrate (3), and the ink was dried and hardened to form the character "a" (reversible thermochromic image (2') that reversibly changes color from one color to another). Next, black non-thermochromic ink was used for screen printing, which was then dried and hardened to form, near the model, numbers corresponding to the stroke order, arrows indicating the direction of the stroke, and images (indicative images) of stroke completion information ('stop' and 'stroke'), as well as the word 'ame' (candy) and a picture of a candy as related images (7) related to the model.

[0118] Furthermore, a reversible thermochromic ink that changes color from colored to colorless was prepared by uniformly dispersing 30 parts of microcapsule pigment H as a reversible thermochromic material, 62 parts of urethane emulsion, 2 parts of thickener, 0.5 parts of leveling agent, 0.5 parts of defoaming agent, and 5 parts of crosslinking agent. The above-mentioned reversible thermochromic ink was screen-printed onto the letters ("a" and "me") that make up the word ("ame"), which is a related image related to the example, and the ink was then dried and hardened to form a circle, which is a reversible thermochromic image (2") that reversibly changes color from colored to colorless.When the reversible thermochromic image is in its colored state, the letters "a" and "me" are hidden by the reversible thermochromic image (see Figure 18, top), and when the reversible thermochromic image is in its colorless state, the letters "a" and "me" are visible (see Figure 18, bottom). Next, a 16 μm thick transparent PET film with an adhesive layer was attached to the entire surface of the substrate on the side where the model and related images related to the model were to be provided (the side opposite the side where the model and related images related to the model were to be provided on the substrate), and laminated to form a transparent protective layer, thereby producing a sheet. A round hole (9) was made in one place at the upper end of the left side of the sheet, and the corners of the sheet were rounded, thereby producing a card-shaped writing learning tool (1) [writing learning card (1″)]. This writing practice card has a base material on one side of which is provided with a model (letter) that changes color from a colored to a different color, and a related image (word and picture) related to the non-thermochromic model, with the model and the related image related to the model being arranged side by side. Furthermore, on the letters that make up the word, a reversible thermochromic image (figure) that changes color from colored to colorless is provided, and when the reversible thermochromic image is in a colored state, it is concealed by the reversible thermochromic image, and when the reversible thermochromic image is in a colorless state, the character is visible.

[0119] In the above writing learning card, the model (2) was changed to the character "i" and the related image (7) related to the model was changed to the word "strawberry" and a picture of a strawberry, and a card-type writing learning tool (1) [writing learning card (1")] was created using the same procedure. In the above writing learning card, the model (2) was changed to the character "u" and the related image (7) related to the model was changed to the word "ukiwa" (float) and a picture of a life jacket, and a card-type writing learning tool (1) [writing learning card (1")] was created using the same procedure. In the above writing learning card, the model (2) was changed to the character "e" and the related image (7) related to the model was changed to the word "pencil" and a picture of a pencil, and a card-type writing learning tool (1) [writing learning card (1")] was created using the same procedure. In the above writing learning card, the model (2) was changed to the character "o" and the related image (7) related to the model was changed to the word "origami" and a picture of origami paper. Using the same procedure, a card-type writing learning tool (1) [writing learning card (1")] was created.

[0120] The holes in the prepared writing learning cards were passed through an openable polypropylene fastener (10) to bind the cards together, and the cards were put to practical use as a booklet-type writing learning tool (1''') (see Figure 19).

[0121] In each card that makes up the booklet-style writing learning tool, the reversible thermochromic material is in a colored state at room temperature (20°C), so the model was purple (first color) (initial state), a mixture of blue from the reversible thermochromic material and pink from the general pigment. When the model was traced with a finger, the heat of the finger (body temperature) caused the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the reversible thermochromic material to decolorize, and the traced area of ​​the model turned pink (second color) due to the general pigment. When this writing learning tool was used, the traced area changed color from one color (first color) to a different color (second color) when the user traced the model with their finger, stimulating the user's visual sense and allowing the user to learn how to write the character with a sense of reality. Furthermore, numbers corresponding to the stroke order, arrows indicating the direction of strokes, and stroke-finding information images (instruction images) were placed near the character (model), allowing the user to accurately learn how to write the character and the stroke order. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. In addition, on each card, a related image (word and picture) related to the example was placed near the example, and the word was concealed by a reversible thermochromic image that changed color from colored to colorless, so that after saying the name shown by the picture, the reversible thermochromic image could be made to disappear with the heat of the fingers (body temperature), allowing the child to confirm whether the name shown by the picture was correct or incorrect. Furthermore, because it was possible to learn how to read specific characters by associating them with words and pictures, it was possible to learn the stroke order and reading of the characters at the same time, promoting the development of language ability. When the application of heat (body temperature) to the model is stopped, the reversible thermochromic material reaches its full color-changing temperature t1, and the reversible thermochromic material changes color, returning the model to its initial purple color (first color).This means that the model can be used repeatedly and is useful as a teaching tool or educational toy. Furthermore, the t3 of the reversible thermochromic material was 21°C, and the writing learning tool was easy to erase the model regardless of factors such as the ambient temperature, season, the user's body temperature, or age, and the traced areas were easy to see. This writing learning tool was excellent in that it was easy to carry multiple cards, allowing students to learn how to write letters regardless of location. Furthermore, because the fasteners could be opened and closed, it was possible to select and bind the desired cards (for example, the letters "a," "e," and "o"), allowing students to learn only specific letters, resulting in excellent learning efficiency.

[0122] Example 11 Creation of writing learning tools (see Figure 20) A reversible thermochromic ink was prepared by uniformly dispersing 15 parts of microcapsule pigment F and 15 parts of microcapsule pigment G as reversible thermochromic materials, 62 parts of urethane emulsion, 2 parts of thickener, 0.5 parts of leveling agent, 0.5 parts of antifoaming agent, 5 parts of crosslinking agent, and 0.2 parts of a pink general pigment. The above-mentioned reversible thermochromic ink was screen-printed onto the right half (140mm x 140mm) of one side of a white coated paper (a rectangle measuring 140mm x 280mm) used as the substrate (3), and the ink was dried and hardened to form the characters ('a', 'i', 'u', 'e', ​​'o') contained in the 'a' row of characters (model (2)) [reversible thermochromic image (2') that reversibly changes color from one color to another]. Next, black non-thermochromic ink was used for screen printing, which was then dried and hardened to form numbers corresponding to the stroke order, arrows indicating the direction of strokes, and stroke ending information ("stops" and "strokes") (indicator images) near the model, as well as a frame surrounding the model. Next, the left half of one side of the substrate (an area of ​​140 mm long x 140 mm wide) was screen-printed using non-thermochromic ink, which was then dried and hardened to form related images (7) related to the model: words beginning with letters included in the "A" row ("candy," "strawberry," "float," "pencil," "origami") and pictures of those words. Next, a 16 μm thick transparent PET film with an adhesive layer was attached to the entire surface of the substrate on the side where the model and related images related to the model were to be placed (the side opposite the side where the model and related images related to the model were to be placed on the substrate), and laminated to form a transparent protective layer.The corners were then rounded to produce a sheet (see the left image in Figure 20).

[0123] In the above sheet, the model (2) was changed to a character included in the "ka" to "wa" row, and the related image (7) related to the model was changed to a word beginning with a character included in the "ka" to "wa" row and a picture of that word, and a sheet related to the "ka" to "wa" row was created using the same procedure.

[0124] The multiple sheets prepared above were folded so that the printed surfaces faced each other and formed a square measuring 140 mm long x 140 mm wide. Next, adhesive was applied to the other side of the sheet related to the "A" row, on which the characters (models) included in the "A" row were printed (the side of the base opposite to the side on which the models were provided), and the sheet related to the "K" row was attached to the other side of the sheet related to the "K" row, on which words starting with characters included in the "K" row and pictures of those words were printed (the side of the base opposite to the side on which related images related to the models were provided) (see the right diagram in Figure 20). The sheets related to the "S" row through "W" row were attached in the same way. Next, a spine was attached to produce a booklet-shaped writing learning tool (1,1"') (picture book).

[0125] On each page of the picture book, the reversible thermochromic material is in a colored state at room temperature (20°C), so the model was purple (first color) (initial state), a mixture of blue from the reversible thermochromic material and pink from the general pigment. When the model was traced with a finger, the heat of the finger (body temperature) caused the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the reversible thermochromic material to decolorize, and the traced area of ​​the model turned pink (second color) due to the general pigment. When this writing learning tool was used, the traced area changed color from one color (first color) to a different color (second color) when the user traced the model with their finger, stimulating the user's visual sense and allowing the user to learn how to write the character with a sense of reality. Furthermore, numbers corresponding to the stroke order and arrows indicating the direction of strokes (instruction images) were placed near the character (model), allowing the user to accurately learn how to write the character and the stroke order. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. In addition, on each page, related images (words and pictures) are placed near the model, allowing students to learn how to read specific characters by associating them with the words and pictures.This means that students can learn the stroke order and reading of characters at the same time, which promotes the development of language skills. When the application of heat (body temperature) to the model is stopped, the reversible thermochromic material reaches its full color-changing temperature t1, and the reversible thermochromic material changes color, returning the model to its initial purple color (first color).This means that the model can be used repeatedly and is useful as a teaching tool or educational toy. The model also uses two types of reversible thermochromic materials (C) that use an ester compound with a ΔT value of 3°C or less. The low-temperature color change points of the model (complete color development temperature t1 and color fade onset temperature t3) are considered to be the low-temperature color change points of reversible thermochromic material F, while the high-temperature color change points (color development onset temperature t2 and color fade onset temperature t4) are considered to be the high-temperature color change points of reversible thermochromic material G. In other words, the model exhibited the following color change behavior: complete color development temperature t1: 24°C, color development onset temperature t2: 30°C, color fade onset temperature t3: 25°C, and complete fade temperature t4: 31°C (t2-t1: 6°C, t4-t3: 6°C, ΔH: 1°C). By using two types of reversible thermochromic materials in combination, it was easy to obtain a writing learning tool in which the model changes color at the desired temperature. The t3 of the reversible thermochromic material was 25°C, and the writing learning tool was easy to erase the model regardless of factors such as the ambient temperature, season, the user's body temperature, and age, and the traced areas were easy to see. This writing learning tool is in the form of a booklet, making it easy to carry around and allowing students to learn how to write characters regardless of location.

[0126] Example 12 Creation of writing learning tools (see Figure 21) A reversible thermochromic ink was prepared by uniformly dispersing 15 parts of microcapsule pigment F and 15 parts of microcapsule pigment G as reversible thermochromic materials, 62 parts of urethane emulsion, 2 parts of thickener, 0.5 parts of leveling agent, 0.5 parts of antifoaming agent, 5 parts of crosslinking agent, and 0.2 parts of a pink general pigment. The substrate (3) was a white coated paper (rectangle, 140 mm long x 160 mm wide), and one side of the substrate was screen-printed with non-thermochromic ink, which was then dried and hardened to form the cover design. Next, on the other side of the substrate (the side opposite the cover design), words beginning with letters in the "A" row ("candy," "strawberry," "float," "pencil," "origami") and pictures of words were printed as related images (7) to the model, producing Sheet 1. Furthermore, nine rectangular holes (9) were made at equal intervals near the left edge of the side on which the cover design was printed, and the top and bottom corners of the right edge were rounded.

[0127] Next, the above-mentioned reversible thermochromic ink was screen-printed on one side of another white coated paper (a square measuring 140 mm long x 160 mm wide) as the substrate (3), and the ink was dried and hardened to form the reversible thermochromic image (2') of the characters contained in the "A" row ("A," "I," "U," "E," and "O"), which is the model (2). Furthermore, black non-thermochromic ink was screen-printed and dried and hardened to form, near the model, numbers corresponding to the stroke order and arrows indicating the stroke direction (indicator images), as well as a frame surrounding the model. Next, the other side of the substrate (3) (the side of the substrate opposite to where the model is to be placed) was screen printed using non-thermochromic ink, which was then dried and hardened to form words beginning with letters included in the "ka" row ("umbrella," "goldfish," "shoes," "watch," "top") and pictures of those words as related images (7) to the model, thereby producing sheet 2. Furthermore, nine rectangular holes (9) were made at equal intervals near the left side of the side on which the model was printed, and the top and bottom corners of the right side were rounded.

[0128] In the above Sheet 2, the model was changed to characters from the "sa" to "wa" rows, and the related images related to the model were changed to words and pictures beginning with characters from the "ta" to "wa" rows, as well as the design of the back cover, and a sheet was created using the same procedure.

[0129] The sheets prepared above were bound with a polypropylene fastener (10) so that the letter (model), the word beginning with that letter, and its picture (a related image related to the model image) faced each other, and were put to practical use as a booklet-type writing learning tool (1,1''') (see Figure 21).

[0130] In each sheet that makes up the booklet-style writing learning tool, the reversible thermochromic material is in a colored state at room temperature (20°C), so the sample was purple (first color) (initial state), a mixture of blue from the reversible thermochromic material and pink from the general pigment. When the model was traced with a finger, the heat of the finger (body temperature) caused the traced area to reach the complete decolorization temperature t4 of the reversible thermochromic material, causing the reversible thermochromic material to decolorize, and the traced area of ​​the model turned pink (second color) due to the general pigment. When this writing learning tool was used, the traced area changed color from one color (first color) to a different color (second color) when the user traced the model with their finger, stimulating the user's visual sense and allowing the user to learn how to write the character with a sense of reality. Furthermore, numbers corresponding to the stroke order and arrows indicating the direction of strokes (instruction images) were placed near the character (model), allowing the user to accurately learn how to write the character and the stroke order. Furthermore, a third party could visually confirm whether the user was tracing the model correctly. Furthermore, on each sheet, images (words and pictures) related to the model are placed to the left of the printed model, allowing students to learn how to read specific characters by associating them with the words and pictures. This allows students to learn the stroke order and reading of characters at the same time, which promotes the development of language skills. When the application of heat (body temperature) to the model is stopped, the reversible thermochromic material reaches its full color-changing temperature t1, and the reversible thermochromic material changes color, returning the model to its initial purple color (first color).This means that the model can be used repeatedly and is useful as a teaching tool or educational toy. The model also uses two types of reversible thermochromic materials (C) that use an ester compound with a ΔT value of 3°C or less. The low-temperature color change points of the model (complete color development temperature t1 and color fade onset temperature t3) are considered to be the low-temperature color change points of reversible thermochromic material F, while the high-temperature color change points (color development onset temperature t2 and color fade onset temperature t4) are considered to be the high-temperature color change points of reversible thermochromic material G. In other words, the model exhibited the following color change behavior: complete color development temperature t1: 24°C, color development onset temperature t2: 30°C, color fade onset temperature t3: 25°C, and complete fade temperature t4: 31°C (t2-t1: 6°C, t4-t3: 6°C, ΔH: 1°C). By using two types of reversible thermochromic materials in combination, it was easy to obtain a writing learning tool in which the model changes color at the desired temperature. The t3 of the reversible thermochromic material was 25°C, and the writing learning tool was easy to erase the model regardless of factors such as the ambient temperature, season, the user's body temperature, and age, and the traced areas were easy to see. This writing learning tool is in the form of a booklet, making it easy to carry around and allowing students to learn how to write characters regardless of location. [Explanation of symbols]

[0131] t1 Complete color development temperature of reversible thermochromic material (reversible thermochromic composition) t2 Color development start temperature of reversible thermochromic material (reversible thermochromic composition) t3 Reversible thermochromic material (reversible thermochromic composition) discoloration starting temperature t4 Complete decolorization temperature of reversible thermochromic material (reversible thermochromic composition) ΔH Hysteresis width 1 Writing learning tools 1′ Writing study sheet 1" Writing Learning Cards 1"' Booklet-style writing aid 2. Example 2' Reversible thermochromic image that changes color reversibly from colored to a different color 2" Reversible thermochromic image that changes color from colored to colorless 2" Non-thermochromic image 3 Base material 4 Transparent protective layer 5 Adhesive layer 6. Heat insulation material (heat insulation sheet) 7. Related Images of the Exemplar 8 Transparent glitter layer (transparent glitter image) 9 Hole 10 Fasteners

Claims

1. A writing learning tool having a base material on which a model selected from the group consisting of letters, numbers, and symbols is provided, The sample contains a reversible thermochromic material, and reversibly changes color from a color to a different color. The reversible thermochromic material is a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that controls the color reaction of the components (a) and (b), or a reversible thermochromic resin particle in which the reversible thermochromic composition is dispersed in a thermoplastic resin or a thermosetting resin. The sample exhibits hysteresis characteristics in a color density-temperature curve, and exhibits alternation between a colored state and a decolorized state. In the process of increasing temperature from the colored state, the decolorization starting temperature t ３ When the temperature reaches t ３ Higher complete bleaching temperature t ４ In the above temperature range, the color is completely lost. In the process of decreasing the temperature from the lost color state, the coloring start temperature t ２ When the temperature reaches t ２ Lower full color temperature t １ It exhibits hysteresis characteristics in which it becomes completely colored in the temperature range below, and completely fades at the temperature t ４ The writing learning tool is a material having a temperature of 26 to 37°C and exhibiting a hysteresis width (ΔH) of 5°C or less in terms of a color density-temperature curve.

2. A writing learning tool having a base material on which a model selected from the group consisting of letters, numbers, and symbols is provided, The sample is composed of a non-thermochromic image and a reversible thermochromic image, and is the letter, number, or symbol whose size or shape at least changes with a temperature change and remains the same before and after the temperature change; The reversible thermochromic image comprises a reversible thermochromic material, and undergoes a reversible color change from colored to colorless. The reversible thermochromic material is a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising at least (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling the color reaction of the components (a) and (b), or reversible thermochromic resin particles in which the reversible thermochromic composition is dispersed in a thermoplastic resin or a thermosetting resin. The reversible thermochromic image exhibits hysteresis characteristics in a color density-temperature curve, exhibiting alternation between a colored state and a decolorized state, and in the process of increasing temperature from the colored state, the decolorization starting temperature t ３ When the temperature reaches t ３ Higher complete bleaching temperature t ４ In the above temperature range, the color is completely lost. In the process of decreasing the temperature from the lost color state, the coloring start temperature t ２ When the temperature reaches t ２ Lower full color temperature t １ It exhibits hysteresis characteristics in which it becomes completely colored in the temperature range below, and completely fades at the temperature t ４ The writing learning tool is a material having a temperature of 26 to 37°C and exhibiting a hysteresis width (ΔH) of 5°C or less in terms of a color density-temperature curve.

3. 3. A writing learning tool according to claim 1, wherein at least one of the following indication images is provided inside or near said model: numbers corresponding to the stroke order of said letters, numbers or symbols; arrows indicating the direction of strokes; and stroke collection information.

4. 3. A writing learning tool according to claim 1, further comprising an image related to said model, said image being selected from the group consisting of letters, numbers, symbols, figures and pictures.

5. 3. A writing learning tool according to claim 1, wherein the reversible thermochromic material exhibits a hysteresis width (ΔH) of 3° C. or less in a color density-temperature curve.

6. 3. A writing learning tool according to claim 1, which comprises two or more types of said reversible thermochromic materials.

7. The decolorization start temperature t ３ 3. The writing learning tool according to claim 1, wherein the temperature is 25° C. or lower.

8. 3. The writing learning tool according to claim 1 or 2, which is in the form of a sheet.

9. A booklet-type writing learning tool comprising the writing learning tool according to claim 1 or 2.

10. 10. The writing learning tool according to claim 9, which is a picture book.

Images