JPH0533152B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to thermochromic compositions. Electron-donating color-forming organic compounds (hereinafter referred to as color formers), compounds that develop color by reacting with color formers (hereinafter referred to as color developers), and compounds that suppress the reaction between color formers and color developers (hereinafter referred to as desensitizers) Thermochromic colorants are known. Such coloring agents are useful as temperature indicators because they produce a so-called thermochromic phenomenon in which the composition reversibly changes color or discolors in response to temperature changes. However, since known thermochromic colorant compositions mainly use phenolic compounds as color developers, their uses may be limited in terms of toxicity. Furthermore, since the phenolic compound is not resistant to air oxidation or exposure to sunlight, it also has problems such as unstable thermochromic properties. The present inventor has conducted various studies in view of the above-mentioned drawbacks of known thermochromic compositions, and has found that the above-mentioned drawbacks can be avoided when saccharin, a sacchulin derivative, or a duplex of saccharin is used as a color developer. It was found that the problem was virtually eliminated. That is, the present invention provides (i) one part of at least one electron-donating color-forming organic compound; (ii) a compound having the general formula At least one of saccharin, a saccalin derivative, or a sacculin duplex represented by
1/10 to 10 parts of seeds, [R is hydrogen, lower alkyl group,
Nitro group, halogen group, allyl group, amino group,
Indicates a carboxylic acid group, sulfonic acid group, dialkylamino group, diallylamino group, hydroxyl group, or alkoxy group. ] and (iii) a thermochromic composition containing at least one compound selected from the group consisting of alcohols, esters, ketones, ethers, acid amides, carboxylic acids, and hydrocarbons. . The inventive agent used in the present invention is not particularly different from those used in known thermochromic colorant compositions. Among these, more preferable compounds are as follows. Triphenylmethane phthalides...crystal violet lactone, malachite green lactone, etc. Fluoranes...3,6-diethoxyfluorane, 3-dimethylamino-6-methyl-7-chlorofluoran, 1,2-benz-6-diethylaminofluorane, 3-diethylamino-7
-Methoxyfluorane etc. Phenothiazines...benzoylleucomethylene blue, methylleucomethylene blue, ethylleucomethylene blue, methoxybenzoylleucomethylene blue, etc. Indolylphthalides...2-(phenyliminoethanedylidene)-3,3-dimethylindoline, etc. Spiropyrans...1,3,3-trimethyl-indolino-7'-chloro-β-naphthospiropyran, di-β-naphthospiropyran, benzo-β
-naphthoisospiropyran, xantho-β-naphthospiropyran, etc. Leuco auramines...N-acetyl auramine, N-phenyl auramine, etc. Rhodamine lactams... Rhodamine B lactam, etc. Examples of saccharin, saccharin derivatives, or saccharin dimers used as a color developer in the present invention include the following. Satucalin, -ethylsactucalin, 1'-nitrosactucalin, 1'-bromsactucalin, phenylsactucalin, 1'-aminosactucalin, hydroxysactucalin, saccalin-5'-carboxylic acid, saccharin sulfonic acid, Examples include dimethylaminosacchulin, diphenylaminosacchulin, 1-methylolsacchulin, P-disactucalin, and m-disactucalin. As the desensitizer used in the present invention, those used in known thermochromic coloring compositions can be used. Among them, more preferable examples are as follows. Alcohols...n-octyl alcohol, n-
Nonyl alcohol, n-decyl alcohol, n
-Lauryl alcohol, n-myristyl alcohol, n-cetyl alcohol, n-stearyl alcohol, n-icosyl alcohol, n-
Docosyl alcohol, oleyl alcohol, cyclohexanol, benzyl alcohol, ethylene glycol, polyethylene glycol, trimethylolpropane, pentaerythritol, etc. Esters...Lauryl caproate, octyl caprate, butyl laurate, dodecyl laurate, hexyl myristate, myristyl myristate, octyl palmitate, stearyl palmitate, butyl stearate, cetyl stearate, lauryl behenate, oleic acid cetyl, butyl benzoate, phenyl benzoate,
dibutyl sebatate, etc. Ketones... cyclohexanone, acetophenone, benzophenone, dimyristyl ketone,
etc. Ethers: dilauryl ether, dicetyl ether, diphenyl ether, ethylene glycol monostearyl ether, etc. Fatty acids: caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, partoleic acid, oleic acid, ricinoleic acid, linoleic acid, Linolenic acid, eleostearic acid, erucic acid, etc. Acid amides: caprylic acid amide, capric acid amide, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, benzamide, etc. Hydrocarbons: aliphatic hydrocarbons such as octane, isooctane, decane, etc. Aromatic hydrocarbons such as benzene, toluene, xylene, etc. Alicyclic hydrocarbons such as cyclohexane, ethylcyclohexane, butylcyclohexane. A mixed solvent of the above sold as ligroin, volatile oil, gasoline, and kerosene. The ratio of color former: color developer: desensitizer in the present invention is usually about 1:1/10:5 to 200, more preferably 1:1/2 to 5:10 to 100, by weight. That's about it. If the amount of color developer is excessive, the reversible color changing property and color erasing property will deteriorate, whereas if the amount of color developer is insufficient, the color density will be low. If the amount of desensitizer is excessive, the coloring density will be low, whereas if it is insufficient, the color erasing property will be decreased. Pigments, extender pigments, etc. can be added to the thermochromic composition of the present invention, if necessary. The composition of the present invention is prepared, for example, as follows. However, the preparation method is completely arbitrary and is not limited to the examples below. When the composition of the present invention is used as a liquid coloring agent for ink for writing instrument ink stamps, etc.,
A desensitizer that can serve as a solvent for a specific color former and developer may be selected and dissolved therein, or the color former, developer, and desensitizer may be dissolved in a solvent. Furthermore, when used as a solid coloring agent for crayons and pastels, the color former, color developer, and desensitizer are melted by heating and dispersed uniformly, then molded into a predetermined shape, and cooled or heated. After uniformly dispersing color formers, color developers, and desensitizers in warmly melted microcrystalline wax, polyethylene, holypropylene, and other excipients, it is molded into a predetermined shape by pouring, injection, or extrusion. , just need to cool it down. According to the present invention, the following effects are achieved. (i) Since the color developer is non-toxic or has low toxicity, there are no restrictions on its uses. (ii) The thermochromic property is stable even after repeated use over a long period of time, and the color changes clearly at a specified temperature. Example 1 1 part of crystal violet lactone (the following parts indicate parts by weight), 1 part of saccharin, and 2 parts of myristyl alcohol were added to 25 parts of myristyl alcohol, melted by heating to 140°C, and after uniformly dispersing, the mixture was poured into a mold. The mixture was poured into a container and cooled to solidify to obtain a crayon-like solid colorant. This colorant was blue at 20°C, but completely disappeared when it was applied to paper and heated to 35°C. This discoloration was reversible. Colorants of Examples 2 to 22 were prepared according to Example 1. The composition and physical properties are shown in Table 1. However, Examples 5, 13 and 16 are liquid at room temperature. Example 23 1 part of NCR (trade name, fluoran dye manufactured by Hodogaya Chemical Industry) 2 parts of 1-methylolsaccharin was added to 25 parts of lauryl alcohol, heated and melted at 120°C, and uniformly dispersed by high-speed stirring. , 0.5 part of Ostapalm Green 8G (trade name, CI Pigment Green 41 manufactured by Hoechst Synthesis) was added, stirring was continued, and the mixture was uniformly dispersed.The mixture was poured into a mold and solidified by cooling to obtain a crayon-like solid colorant. . This colorant was purple at 20°C, but when it was applied to a glass board and heated to 22°C, it turned green. This discoloration was reversible. Colorants of Examples 24 and 25 were prepared according to Example 23. The composition and physical properties are shown in Table 2.

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Claims (1)

[Claims] 1 (i) at least one electron-donating color-forming organic compound, 1 part (ii) general formula At least one type of sacculin, saccalin derivative, or saccalin dimer represented by
1/10 to 10 parts [R is hydrogen, lower alkyl group, nitro group, halogen group, allyl group, amino group, carboxylic acid group,
Indicates a sulfonic acid group, dialkylamino group, diallylamino group, hydroxyl group, or alkoxy group. ] and (iii) a thermochromic material containing 5 to 200 parts of at least one compound selected from the group consisting of alcohols, esters, ketones, ethers, acid amides, carboxylic acids, and hydrocarbons. Composition.