Reversible thermochromic composition, writing implement and toy using said reversible thermochromic composition

Abstract

The present invention addresses the problem of providing: a reversible thermochromic composition that has a non-phenolic structure with low load on a human body and the environment and that has both excellent color development sensitivity and decoloring property; a writing instrument that accommodates the reversible thermochromic composition; and a toy that contains the reversible thermochromic composition.　This problem is solved by a reversible thermochromic composition containing: a color developer that contains a compound which has a sulfonylurea (-NH-CO-NH-SO2-) moiety represented by formula (1); a leuco dye; and a discoloration temperature adjusting agent. (In formula (1), A is an optionally substituted aryl group, heteroaryl group, alkyl group, or cycloalkyl group, and B is an optionally substituted aryl group, heteroaryl group, or alkyl group.)

Description

[Technical Field]

[0001] The present invention relates to a reversible thermochromic composition, a writing instrument containing the reversible thermochromic composition, and a toy including the reversible thermochromic composition. [Background technology]

[0002] The reversible thermochromic composition mainly comprises a basic (electron-donating) leuco dye (hereinafter sometimes abbreviated as "leuco dye"), an electron-accepting color developer (hereinafter sometimes abbreviated as "color developer"), and a color change temperature regulator. The color change temperature regulator controls the switching between the colorless state and the colored state by reversibly inducing an electron donor-acceptor reaction between the leuco dye and the color developer within a specific temperature range (for example, Patent Document 1).

[0003] The color developer contained in the reversible thermochromic composition is often a compound mainly having a bisphenol structure, such as 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane (bisphenol AF), etc. However, from the viewpoint of the influence of the bisphenol structure on environmental hormones, etc., it is considered preferable to use a compound that does not have a bisphenol structure or a phenol structure as a color developer.

[0004] Patent Documents 2, 3 and 4 disclose reversible thermochromic compositions containing diphenylurea or diphenylthiourea as color developers having neither a bisphenol structure nor a phenol structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-213361 [Patent Document 2] Japanese Patent Application Publication No. 62-140881 [Patent Document 3] Japanese Patent Application Publication No. 62-079283 [Patent Document 4] Japanese Patent Application Publication No. 62-101684 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, there is a need for the development of color developers that are less harmful to the human body and the environment than compounds primarily having a bisphenol structure or a phenol structure. Furthermore, the present inventors have prepared reversibly color-changing compositions using the color developers disclosed in Patent Documents 2 to 4 and evaluated their color-developing sensitivity and decoloring properties, but found that the compositions did not exhibit sufficient color-developing sensitivity and decoloring properties. That is, the object of the present invention is to provide a reversible thermochromic composition which has a non-phenolic structure that places a low burden on the human body and the environment and which combines excellent color development sensitivity with decolorization ability, as well as a writing instrument containing the reversible thermochromic composition and a toy containing the reversible thermochromic composition. [Means for solving the problem]

[0007] As a result of extensive investigations, the present inventors have found that the above problems can be solved by using a compound having a sulfonylurea moiety as a color developer.

[0008] [1] A reversible thermochromic composition comprising a developer containing a compound having a sulfonylurea (-NH-CO-NH-SO2-) moiety represented by the following formula (1), a leuco dye, and a color-change temperature regulator: [ka] (In the above formula (1), A is an aryl group, heteroaryl group, alkyl group, or cycloalkyl group which may have a substituent, and B is an aryl group, heteroaryl group, or alkyl group which may have a substituent.) [2] In the formula (1), A is an aryl group or a heteroaryl group, and A is a substituent R other than a hydrogen atom. 0 and R 0is bonded at the o-position relative to the NH group adjacent to A. However, A is R 0 It may have a substituent other than the above. [3] R 0 is a halogen atom, a nitrile group, a carboxyl group, or an alkyl group, aryl group, heteroaryl group, ether group, thioether group, oxycarbonyl group, carbonyloxy group, carbonyl group, amino group, carbonylamino group, aminocarbonyl group, urea group, sulfonylamido group, aminosulfonyl group, sulfinyl group, sulfonyl group, or sulfonyloxy group which may have a substituent. [4] R 0 is a fluoro group or an alkyl group having at least one fluoro group. [5] The reversible thermochromic composition according to [1], wherein A in the formula (1) is a secondary or tertiary alkyl group or a cycloalkyl group. [6] A microcapsule pigment in which the reversible thermochromic composition according to any one of [1] to [5] is encapsulated in a microcapsule. [7] A writing instrument containing the reversible thermochromic composition according to any one of [1] to [5] or the microcapsule pigment according to [6]. [8] A toy comprising the reversible thermochromic composition according to any one of [1] to [5] or the microcapsule pigment according to [6]. [Effects of the Invention]

[0009] According to the present invention, there are provided a reversible thermochromic composition having excellent color development sensitivity and decolorization properties, a writing instrument containing the reversible thermochromic composition, and a toy containing the reversible thermochromic composition. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below, but the present invention is not limited to the following description and can be practiced with any modifications within the scope of the gist of the present invention. In the present invention, when a numerical value or a physical property value is enclosed by "~", the values ​​before and after the "~" are used to include the values ​​before and after the "~"

[0011] The reversible thermochromic composition according to the present invention comprises a color developer containing a compound having a sulfonylurea (-NH-CO-NH-SO2-) moiety, a leuco dye, and a color change temperature adjuster.

[0012] The reversible thermochromic composition of the present invention exhibits the remarkable effects of being excellent in color-developing sensitivity and decolorizing property when heat is applied. It is believed that the reversible thermochromic composition exhibits high color-developing sensitivity, particularly due to the presence of a sulfonylurea group that is highly reactive with a leuco dye.

[0013] [Developer] A reversible thermochromic composition according to one embodiment of the present invention comprises a color developer containing a compound represented by the following formula (1): In this specification, the compound represented by formula (1) may be referred to as "compound (1)." [ka] (In the above formula (1), A is an aryl group, heteroaryl group, alkyl group, or cycloalkyl group which may have a substituent, and B is an aryl group, heteroaryl group, or alkyl group which may have a substituent.)

[0014] In the above formula (1), A is an aryl group (also called an aromatic hydrocarbon group), a heteroaryl group (also called an aromatic heterocyclic group), an alkyl group, or a cycloalkyl group, preferably an aromatic hydrocarbon group having 6 to 20 carbon atoms, an aromatic heterocyclic group having 2 to 20 carbon atoms, an alkyl group having 1 to 22 carbon atoms, or a cycloalkyl group having 3 to 22 carbon atoms.

[0015] Examples of aromatic hydrocarbon groups include phenyl, naphthyl, phenanthryl, biphenyl, anthryl, pyrenyl, fluorenyl, azulenyl, acenaphthenyl, fluoranthenyl, naphthacenyl, perylenyl, pentacenyl, triphenylenyl, and quaterphenyl groups. Among these, phenyl and naphthyl groups are preferred.

[0016] Examples of aromatic heterocyclic groups include pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, oxadiazolyl, thiadiazolyl, pyrazinyl, pyrimidinyl, pyrazolyl, imidazolyl, benzothienyl, dibenzofuryl, dibenzothienyl, phenylcarbazolyl, phenoxathienyl, xanthenyl, benzofuranyl, thianthrenyl, indolizinyl, phenoxazinyl, phenothiazinyl, acridinyl, phenanthridinyl, phenanthrolinyl, quinolyl, isoquinolyl, indolyl, and quinoxalinyl. Among these, a pyridyl group, a pyrazinyl group, a pyrimidinyl group, a pyrazolyl group, a quinolyl group, an isoquinolyl group, an imidazolyl group, an acridinyl group, a phenanthridinyl group, a phenanthrolinyl group, a quinoxalinyl group, a dibenzofuryl group, a dibenzothienyl group, a phenylcarbazolyl group, a xanthenyl group, or a phenoxazinyl group is preferred.

[0017] Among the aryl group, heteroaryl group, alkyl group, and cycloalkyl group, an aromatic hydrocarbon group or an alkyl group is preferred, and a phenyl group is particularly preferred, since it is easy to improve the color development sensitivity and decolorization property by improving the compatibility with the leuco dye and the color change temperature regulator.

[0018] When A is an aryl or heteroaryl group, the aryl and heteroaryl groups preferably have a substituent R other than a hydrogen atom. 0 and R 0 is bonded at the o-position to the NH group adjacent to A. In this case, A is R 0 It may have a substituent other than the above.

[0019] R 0 is not particularly limited, and examples thereof include a halogen atom, a nitrile group, a carboxyl group, or an alkyl group which may have a substituent, an aryl group, a heteroaryl group, an ether group, a thioether group, an oxycarbonyl group, a carbonyloxy group, a carbonyl group, an amino group, a carbonylamino group, an aminocarbonyl group, a urea group, a sulfonylamido group, an aminosulfonyl group, a sulfinyl group, a sulfonyl group, or a sulfonyloxy group.

[0020] Examples of the halogen atom include a fluoro group, a chloro group, a bromo group, and an iodo group. A fluoro group, a chloro group, or a bromo group is preferred because it has a high reactivity with the leuco dye. A fluoro group or a chloro group is particularly preferred because it tends to have high light resistance, and a fluoro group is more preferred.

[0021] The alkyl group is preferably a linear or branched alkyl group having 1 to 22 carbon atoms, which may have a substituent. The alkyl group enhances compatibility with the discoloration temperature regulator and improves decolorization properties. If the number of carbon atoms is too large, the melting point may be too low, reducing the preservability of the colored state and reducing color development properties. Therefore, the number of carbon atoms is preferably 12 or less, more preferably 6 or less, and particularly preferably 4 or less.

[0022] Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, a 1-ethylpentyl group, an octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, an eicosyl group, a heniicosyl group, and a docosyl group. Preferably, it is a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, or hexyl group, more preferably a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, or t-butyl group, and particularly preferably a methyl group.

[0023] The alkyl group may have a substituent, and a halogen atom is preferred as the substituent because the electron-withdrawing property enhances the reactivity with the leuco dye. Among these, a fluoro group, a chloro group, or a bromo group is preferred, and a fluoro group is particularly preferred.

[0024] Among the alkyl groups, R 0 It is particularly preferred that R is an alkyl group having at least one fluoro group. 0 If R has at least one fluoro group, its electron-withdrawing property can increase the color development sensitivity. There are no restrictions on the position or number of fluoro groups, but the more fluoro groups there are, the higher the electron-withdrawing property and the higher the reactivity with the leuco dye. 0 is preferably a perfluoroalkyl group. On the other hand, if the number of fluoro groups is too large, it is thought that the compatibility with the leuco dye and the color-changing temperature regulator will decrease, resulting in a decrease in color-developing sensitivity and decolorization property. The strong electron-withdrawing property increases the reactivity with the leuco dye and provides appropriate compatibility, so R 0 is particularly preferably a trifluoromethyl group.

[0025] The aryl group and heteroaryl group are, respectively, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 2 to 20 carbon atoms which may have a substituent. Examples of aromatic hydrocarbon groups include phenyl, naphthyl, phenanthryl, biphenyl, anthryl, pyrenyl, fluorenyl, azulenyl, acenaphthenyl, fluoranthenyl, naphthacenyl, perylenyl, pentacenyl, triphenylenyl, and quaterphenyl groups. Among these, phenyl and naphthyl groups are preferred.

[0026] Examples of aromatic heterocyclic groups include pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, oxadiazolyl, thiadiazolyl, pyrazinyl, pyrimidinyl, pyrazolyl, imidazolyl, benzothienyl, dibenzofuryl, dibenzothienyl, phenylcarbazolyl, phenoxathienyl, xanthenyl, benzofuranyl, thianthrenyl, indolizinyl, phenoxazinyl, phenothiazinyl, acridinyl, phenanthridinyl, phenanthrolinyl, quinolyl, isoquinolyl, indolyl, and quinoxalinyl. Among these, a pyridyl group, a pyrazinyl group, a pyrimidinyl group, a pyrazolyl group, a quinolyl group, an isoquinolyl group, an imidazolyl group, an acridinyl group, a phenanthridinyl group, a phenanthrolinyl group, a quinoxalinyl group, a dibenzofuryl group, a dibenzothienyl group, a phenylcarbazolyl group, a xanthenyl group, and a phenoxazinyl group are preferred.

[0027] Among the aryl groups and heteroaryl groups, aromatic hydrocarbon groups are preferred, and phenyl groups are particularly preferred, since they can improve compatibility with leuco dyes and discoloration temperature regulators, thereby easily increasing color development sensitivity and decolorization properties.

[0028] The ether group is represented by the following formula (2). [ka]

[0029] In the above formula (2), R 1 is an alkyl group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 14 carbon atoms, or an aromatic heterocyclic group having 2 to 10 carbon atoms, which may have any substituent. Alkyl groups are preferred because they can reduce crystallinity, thereby increasing compatibility with the discoloration temperature regulator and improving the decolorization properties, and aromatic hydrocarbon groups are preferred because they increase compatibility with the discoloration temperature regulator and improve the decolorization properties. In the formula (2), * indicates the site where A is bonded.

[0030] Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, 1-ethylpentyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, and dodecyl. If the chain length is too long, compatibility with the color change temperature regulator becomes too high, and the stability of the colored state tends to decrease. Therefore, preferred are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, and decyl groups.

[0031] Examples of aromatic hydrocarbon groups include phenyl, naphthyl, phenanthryl, biphenyl, anthryl, pyrenyl, fluorenyl, azulenyl, acenaphthenyl, fluoranthenyl, naphthacenyl, perylenyl, pentacenyl, triphenylenyl, and quaterphenyl groups. Among these, phenyl and naphthyl groups are preferred.

[0032] Examples of aromatic heterocyclic groups include pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, oxadiazolyl, thiadiazolyl, pyrazinyl, pyrimidinyl, pyrazolyl, imidazolyl, benzothienyl, dibenzofuryl, dibenzothienyl, phenylcarbazolyl, phenoxathienyl, xanthenyl, benzofuranyl, thianthrenyl, indolizinyl, phenoxazinyl, phenothiazinyl, acridinyl, phenanthridinyl, phenanthrolinyl, quinolyl, isoquinolyl, indolyl, and quinoxalinyl. Among these, a pyridyl group, a pyrazinyl group, a pyrimidinyl group, a pyrazolyl group, a quinolyl group, an isoquinolyl group, an imidazolyl group, an acridinyl group, a phenanthridinyl group, a phenanthrolinyl group, a quinoxalinyl group, a dibenzofuryl group, a dibenzothienyl group, a phenylcarbazolyl group, a xanthenyl group, or a phenoxazinyl group is preferred.

[0033] The thioether group is represented by the following formula (3). [ka]

[0034] In the above formula (3), R 2 is R 1 An alkyl group is preferred because it is possible to increase compatibility with the discoloration temperature regulator and improve the decolorization property by decreasing the crystallinity, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. In the formula (3), * indicates the site where A is bonded.

[0035] The oxycarbonyl group is represented by the following formula (4). [ka]

[0036] In the above formula (4), R 3 is R 1An alkyl group is preferred because it is possible to increase compatibility with the discoloration temperature regulator and improve the decolorization property by decreasing the crystallinity, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. R 0 When is an oxycarbonyl group, its electron-withdrawing property can enhance the reactivity with the leuco dye, and at the same time, the compatibility with the discoloration temperature regulator can be improved, thereby improving the decolorization property. In the formula (4), * indicates the bonding site to A.

[0037] The carbonyloxy group is represented by the following formula (5). [ka]

[0038] In the above formula (5), R 4 is R 1 An alkyl group is preferred because it is possible to increase compatibility with the discoloration temperature regulator and improve the decolorization property by decreasing the crystallinity, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. In the formula (5), * indicates the bonding site to A.

[0039] The carbonyl group is represented by the following formula (6). [ka]

[0040] In the above formula (6), R 5 is R 1 An alkyl group is preferred because it is possible to increase compatibility with the discoloration temperature regulator and improve the decolorization property by decreasing the crystallinity, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. R 0When is a carbonyl group, its electron-withdrawing property can enhance the reactivity with the leuco dye, and at the same time, the compatibility with the discoloration temperature regulator can be improved, thereby improving the decolorization property. In the formula (6), * indicates the bonding site to A.

[0041] The amino group is represented by the following formula (7). [ka]

[0042] In the above formula (7), R 6 is R 1 The same applies to R. An alkyl group is preferred because it can reduce crystallinity, thereby increasing compatibility with the discoloration temperature regulator and improving the decolorization property, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. 0 When R is an amino group, the number of hydrogen atoms that contribute to the reaction with the leuco dye increases, which increases the color development sensitivity and improves compatibility with the color change temperature regulator, thereby improving the decolorization property. 0 In particular, R 6 is an aromatic hydrocarbon group or an aromatic heterocyclic group, and among these, an aromatic hydrocarbon group is preferred. In the formula (7), * indicates the bonding site to A.

[0043] The carbonylamino group is represented by the following formula (8). [ka]

[0044] In the above formula (8), R 7 is R 1The same applies to R. An alkyl group is preferred because it can reduce crystallinity, thereby increasing compatibility with the discoloration temperature regulator and improving the decolorization property, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. 0 is a carbonylamino group, the number of hydrogen atoms that contribute to the reaction with the leuco dye increases, making it possible to enhance the color-developing sensitivity and, at the same time, improve the compatibility with the color-change temperature regulator, thereby improving the decolorization property. In the formula (8), * indicates the site where A is bonded.

[0045] The aminocarbonyl group is represented by the following formula (9). [ka]

[0046] In the above formula (9), R 8 is R 1 The same applies to R. An alkyl group is preferred because it can reduce crystallinity, thereby increasing compatibility with the discoloration temperature regulator and improving the decolorization property, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. 0 When is an aminocarbonyl group, its electron-withdrawing property can enhance the reactivity with the leuco dye, and at the same time, the compatibility with the discoloration temperature regulator can be improved, thereby improving the decolorization property. In the formula (9), * indicates the bonding site to A.

[0047] The urea group is represented by the following formula (10). [ka]

[0048] In the above formula (10), R 9 is R 1The same applies to R. An alkyl group is preferred because it can reduce crystallinity, thereby increasing compatibility with the discoloration temperature regulator and improving the decolorization property, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. 0 When is a urea group, the number of hydrogen atoms that contribute to the reaction with the leuco dye increases, thereby increasing the color-developing sensitivity and, at the same time, improving the compatibility with the color-change temperature regulator and thereby improving the decolorization property. In the formula (10), * indicates the bonding site to A.

[0049] The sulfonylamido group is represented by the following formula (11). [ka]

[0050] In the above formula (11), R 10 is R 1 The same applies to R. An alkyl group is preferred because it can reduce crystallinity, thereby increasing compatibility with the discoloration temperature regulator and improving the decolorization property, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. 0 is a sulfonylamide group, the number of hydrogen atoms that contribute to the reaction with the leuco dye increases, making it possible to enhance the color-developing sensitivity and, at the same time, improve the compatibility with the color-change temperature regulator, thereby improving the decolorization property. In the formula (11), * indicates the bonding site to A.

[0051] The aminosulfonyl group is represented by the following formula (12). [ka]

[0052] In the above formula (12), R 11 is R 1The same applies to R. An alkyl group is preferred because it can reduce crystallinity, thereby increasing compatibility with the discoloration temperature regulator and improving the decolorization property, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. 0 When is an aminosulfonyl group, its electron-withdrawing property can enhance the reactivity with the leuco dye, and at the same time, the compatibility with the discoloration temperature regulator can be improved, thereby improving the decolorization property. In addition, in formula (12), * is the site to which A is bonded.

[0053] The sulfinyl group is represented by the following formula (13). [ka]

[0054] In the above formula (13), R 12 is R 1 The same applies to R. An alkyl group is preferred because it can reduce crystallinity, thereby increasing compatibility with the discoloration temperature regulator and improving the decolorization property, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. 0 When is a sulfinyl group, its electron-withdrawing property can enhance the reactivity with the leuco dye, and at the same time, the compatibility with the discoloration temperature regulator can be improved, thereby improving the decolorization property. In the formula (13), * indicates the bonding site to A.

[0055] The sulfonyl group is represented by the following formula (14). [ka]

[0056] In the above formula (14), R 13 is R 1The same applies to R. An alkyl group is preferred because it can reduce crystallinity, thereby increasing compatibility with the discoloration temperature regulator and improving the decolorization property, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. 0 When is a sulfonyl group, its electron-withdrawing property can enhance the reactivity with the leuco dye, and at the same time, the compatibility with the discoloration temperature regulator can be improved, thereby improving the decolorization property. In the formula (14), * indicates the bonding site to A.

[0057] The sulfonyloxy group is represented by the following formula (15). [ka]

[0058] In the above formula (15), R 14 is R 1 An alkyl group is preferred because it is possible to increase compatibility with the discoloration temperature regulator and improve the decolorization property by decreasing the crystallinity, and an aromatic hydrocarbon group or aromatic heterocyclic group is preferred because it increases compatibility with the discoloration temperature regulator and improves the decolorization property. In the formula (15), * indicates the bonding site to A.

[0059] R 0 is preferably selected from a chloro group, a fluoro group, a nitrile group, a carboxyl group, an alkyl group, an alkyl group having at least one fluoro group, an ether group which may have a substituent, an oxycarbonyl group, a carbonyloxy group, a carbonyl group, an aminocarbonyl group, an aminosulfonyl group, a sulfinyl group, a sulfonyl group, or a sulfonyloxy group, and more preferably selected from a fluoro group, an alkyl group, an alkyl group having at least one fluoro group, an ether group which may have a substituent, an oxycarbonyl group, a carbonyloxy group, or a sulfonyloxy group. 0In particular, a fluoro group or an alkyl group having at least one fluoro group is preferred because it is easy to achieve both improved reactivity with the leuco dye due to its strong electron-withdrawing property and improved compatibility with the leuco dye, and a trifluoromethyl group is particularly preferred.

[0060] R 0 is substituted at the o-position relative to the NH group adjacent to A in formula (1). By substituting at the o-position in this way, it is thought that the steric hindrance and electronic repulsion thereof can moderately reduce the stability of the colored state resulting from the reaction with the leuco dye, thereby effectively improving the decolorization property when heat is applied.

[0061] In the above formula (1), A is R 0 R may have a substituent other than 0 There is no particular limitation on the type or number of substituents other than R 0 The same can be mentioned.

[0062] R 0 As the substituent other than (a), a halogen atom, a nitrile group, a carboxyl group, or an oxycarbonyl group, carbonyl group, aminocarbonyl group, aminosulfonyl group, sulfinyl group, or sulfonyl group which may have a substituent is preferred because it can enhance color development due to its electron-withdrawing property, and among these, a halogen atom or an oxycarbonyl group or carbonyl group which may have a substituent is preferred because it is easy to enhance compatibility with the leuco dye. As the halogen atom, a fluoro group or a chloro group is preferred. From the viewpoint that the color development can be enhanced by being a proton-donating functional group, R 0 The substituent other than the above is preferably a carboxyl group, or an amino group, a carbonylamino group, a urea group, or a sulfonylamido group which may have a substituent. From the viewpoint of increasing the compatibility with leuco dyes and color-changing temperature regulators, R 0The substituent other than the above is preferably a halogen atom, or an optionally substituted alkyl group, aryl group, ether group, thioether group, carbonyl group, oxycarbonyl group, carbonyloxy group, or sulfonyloxy group, and among these, a halogen atom, or an optionally substituted alkyl group, aryl group, ether group, or thioether group is preferred.

[0063] R 0 Particularly preferred substituents other than the above are a fluoro group, a chloro group, or an alkyl group, aryl group, ether group, thioether group, carbonyl group, oxycarbonyl group, carbonyloxy group, or sulfonyloxy group which may have a substituent, and among these, particularly preferred are a fluoro group, a chloro group, or an alkyl group, ether group, oxycarbonyl group, carbonyloxy group, or sulfonyloxy group which may have a substituent.

[0064] R 0 The number of substituents other than R is not particularly limited, but may be 0 to 4, and may be 1 or more, or may be 2 or more. 0 When the number of substituents other than 0 The substituents other than may be different from each other or may be the same.

[0065] When A is an alkyl group or a cycloalkyl group, the alkyl group or the cycloalkyl group is preferably a linear or branched alkyl group having 1 to 22 carbon atoms, which may have a substituent, or a cycloalkyl group having 3 to 22 carbon atoms, which may have a substituent. The alkyl group or the cycloalkyl group can weaken the protonity of the adjacent NH group compared to an aryl group or a heteroaryl group, thereby appropriately reducing the stability of the colored state after reaction with the leuco dye, which is thought to effectively improve the decolorization property when heated. Furthermore, the alkyl group enhances compatibility with the discoloration temperature regulator, improving the decolorization property. Since a too large number of carbon atoms is thought to lower the melting point too much, resulting in poor preservation of the colored state and reduced color development, the linear or branched alkyl group preferably has 12 or fewer carbon atoms, more preferably 6 or fewer carbon atoms, and particularly preferably 4 or fewer carbon atoms. Furthermore, the cycloalkyl group preferably has 12 or fewer carbon atoms, more preferably 8 or fewer carbon atoms.

[0066] Examples of the linear or branched alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, henicosyl, and docosyl. Preferred are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, or hexyl, and more preferred are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, or t-butyl. Particularly preferred are secondary or tertiary alkyl groups, specifically isopropyl, sec-butyl, or t-butyl groups, because they can moderately reduce the stability of the color-developed state due to steric hindrance.

[0067] Examples of the cycloalkyl group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group. Preferred are a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group, and particularly preferred is a cyclohexyl group.

[0068] Among the alkyl groups, secondary or tertiary alkyl groups or cycloalkyl groups are preferred, and among these, an isopropyl group, a sec-butyl group, a t-butyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group is preferred, and an isopropyl group, a sec-butyl group, or a cyclohexyl group is particularly preferred.

[0069] These groups may have a substituent. The substituent may be any of the R groups that A may have. 0 The substituents other than the above are the same as those mentioned above.

[0070] In the above formula (1), B is an aryl group, a heteroaryl group, or an alkyl group which may have a substituent. The aryl group and heteroaryl group are the same as those of A.

[0071] The alkyl group is preferably a linear or branched alkyl group having 1 to 22 carbon atoms, which may have a substituent. The alkyl group enhances compatibility with the discoloration temperature regulator and improves decolorization properties. If the number of carbon atoms is too large, the melting point may be too low, reducing the preservability of the colored state and reducing color development properties. Therefore, the number of carbon atoms is preferably 12 or less, more preferably 6 or less, and particularly preferably 4 or less.

[0072] Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, henicosyl, and docosyl. Preferred are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, or hexyl, more preferred are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, or t-butyl, and particularly preferred is methyl.

[0073] These groups may have a substituent. There is no particular limitation on the type or number of the substituent. 0 The same can be mentioned.

[0074] Specific examples of the above formula (1) include, but are not limited to, the following: [ka] [ka] [ka] [ka] [ka] [ka]

[0075] [Leuco dye] The reversible thermochromic composition according to an embodiment of the present invention contains a leuco dye. The leuco dye is usually basic, and any known leuco dye can be used. Specific examples of leuco dyes include conventionally known diphenylmethane phthalides, phenylindolyl phthalides, indolyl phthalides, diphenylmethane azaphthalides, phenylindolyl azaphthalides, fluorans, styriinoquinolines, and diazarhodamine lactones. These leuco dyes (leuco dye precursors) may be used alone or in combination of two or more. The developer is preferably used in an amount of 0.1 to 50 parts by weight, more preferably 0.5 to 20 parts by weight, per part by weight of the leuco dye.

[0076] Specific examples of leuco dyes are listed below. 3,3-Bis(p-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-(N-ethylanilino)phenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3,6-diphenylaminofluoran, 3,6-dimethoxy Cyfluoran, 3,6-di-n-butoxyfluoran, 2-methyl-6-(N-ethyl-Np-tolylamino)fluoran, 3-chloro-6-cyclohexylaminofluoran, 2-methyl-6-cyclohexylaminofluoran, 2-(2-chloroanilino)-6-di-n-butylaminofluoran, 2-(3-trifluoromethylanilino)-6-diethylaminofluoran, 2-(N-methylanilino)-6-(N-ethyl-Np-tolylamino)fluoran, 1,3-dimethyl-6-diethylaminofluoran, 2-chloro-3-methyl-6-di Ethylaminofluoran, 2-anilino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-di-n-butylaminofluoran, 2-xylidino-3-methyl-6-diethylaminofluoran, 1,2-benz-6-diethylaminofluoran, 1,2-benz-6-(N-ethyl-N-isobutylamino)fluoran, 1,2-benz-6-(N-ethyl-N-isoamylamino)fluoran, 2-(3-methoxy-4-dodecoxystyryl)quinoline, spiro[5H-(1)benzopyrano(2,3-d)pyrimidine-5, 1'(3'H)isobenzofuran]-3'-one, 2-(diethylamino)-8-(diethylamino)-4-methyl-spiro[5H-(1)benzopyrano(2,3-d)pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(di-n-butylamino)-4-methyl-spiro[5H-(1)benzopyrano(2,3-d)pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(diethylamino)-4-methyl-spiro[5H-(1)benzopyrano(2,3-d) pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(N-ethyl-Ni-amylamino)-4-methyl-spiro[5H-(1)benzopyrano(2,3-d)pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, 2-(di-n-butylamino)-8-(di-n-butylamino)-4-phenyl-spiro[5H-(1)benzopyrano(2,3-d)pyrimidin-5,1'(3'H)isobenzofuran]-3'-one, Examples include 3-(2-methoxy-4-dimethylaminophenyl)-3-(1-butyl-2-methylindol-3-yl)-4,5,6,7-tetrachlorophthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)-4,5,6,7-tetrachlorophthalide, and 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-pentyl-2-methylindol-3-yl)-4,5,6,7-tetrachlorophthalide. Further examples include pyridine-based, quinazoline-based and bisquinazoline-based compounds, which are effective in producing fluorescent yellow to red color development.

[0077] [Discoloration temperature regulator] The reversible thermochromic composition of this embodiment contains a color-change temperature regulator, which is a substance that reversibly induces an electron donor-acceptor reaction between the color developer and the leuco dye. Known discoloration temperature regulators can be used, and specific examples include chain hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, alcohols, esters, ketones, ethers, and acid amides. Among these, those having 8 or more carbon atoms are preferred, and those having 10 or more carbon atoms are more preferred. Furthermore, those having 30 or less carbon atoms are preferred.

[0078] Specific examples of the ester include compounds represented by the following formulas (16) to (19) (hereinafter, sometimes referred to as compounds (16) to (19)). [ka] (In formula (16), X independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom; m independently represents an integer of 1 to 3; and n independently represents an integer of 1 to 8.)

[0079] Examples of compound (16) include the diester of malonic acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, the diester of succinic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of succinic acid and 2-[4-(3-methylbenzyloxy)phenyl]ethanol, the diester of glutaric acid and 2-(4-benzyloxyphenyl)ethanol, the diester of glutaric acid and 2-[4-(4-chlorobenzyloxy)phenyl]ethanol, the diester of adipic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of pimelic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of suberic acid and 2-(4-benzyloxyphenyl)ethanol, and the diester of suberic acid and 2-[4-(3-methylbenzyloxy)phenyl]ethanol. Examples thereof include the diester of suberic acid and 2-[4-(4-chlorobenzyloxy)phenyl)]ethanol, the diester of suberic acid and 2-[4-(2,4-dichlorobenzyloxy)phenyl]ethanol, the diester of azelaic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of sebacic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of 1,10-decanedicarboxylic acid and 2-(4-benzyloxyphenyl)ethanol, the diester of 1,18-octadecanedicarboxylic acid and 2-(4-benzyloxyphenyl)ethanol, and the diester of 1,18-octadecanedicarboxylic acid and 2-[4-(2-methylbenzyloxy)phenyl)]ethanol.

[0080] [ka] (In formula (17), R 15 is a hydrogen atom or a methyl group, r is an integer of 0 to 2, and X 1 , X 2 Either one of them is -(CH2)n OCOR 16 or -(CH2) n COOR 16 the other is a hydrogen atom, n is an integer of 0 to 2, and R 16 is an alkyl or alkenyl group having 4 or more carbon atoms, and Y 1 and Y 2 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom, and p and q are each independently an integer of 1 to 3.

[0081] In the formula (17), R 15 is a hydrogen atom, it is preferable because a reversible thermochromic composition having a wider hysteresis width can be obtained, and R 15 It is more preferable that is a hydrogen atom and m is 0.

[0082] Among the compounds (17), the compound represented by the following formula (18) is more preferred. [ka] (In formula (18), R 16 is an alkyl or alkenyl group having 7 or more carbon atoms, preferably an alkyl group having 9 to 24 carbon atoms, and more preferably an alkyl group having 9 to 20 carbon atoms.

[0083] Examples of compound (18) include 4-benzyloxyphenylethyl octanoate, 4-benzyloxyphenylethyl nonanoate, 4-benzyloxyphenylethyl decanoate, 4-benzyloxyphenylethyl undecanoate, 4-benzyloxyphenylethyl dodecanoate, 4-benzyloxyphenylethyl tridecanoate, 4-benzyloxyphenylethyl tetradecanoate, 4-benzyloxyphenylethyl pentadecanoate, 4-benzyloxyphenylethyl hexadecanoate, 4-benzyloxyphenylethyl heptadecanoate, and 4-benzyloxyphenylethyl octadecanoate.

[0084] [ka] (In formula (19), R 17 is an alkyl or alkenyl group having 7 or more carbon atoms, s and t are each independently an integer of 1 to 3, and X 3 and Y 3 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom.

[0085] Examples of compound (19) include 1,1-diphenylmethyl octanoate, 1,1-diphenylmethyl nonanoate, 1,1-diphenylmethyl decanoate, 1,1-diphenylmethyl undecanoate, 1,1-diphenylmethyl dodecanoate, 1,1-diphenylmethyl tridecanoate, 1,1-diphenylmethyl tetradecanoate, 1,1-diphenylmethyl pentadecanoate, 1,1-diphenylmethyl hexadecanoate, 1,1-diphenylmethyl heptadecanoate, and 1,1-diphenylmethyl octadecanoate. These discoloration temperature regulators may be used alone or in combination of two or more.

[0086] The discoloration temperature regulator is preferably used in an amount of 1 to 800 parts by weight, more preferably 5 to 200 parts by weight, per 1 part by weight of the leuco dye.

[0087] By heating to a temperature exceeding the melting point of the discoloration temperature regulator, the colored state caused by the electron donor / acceptor reaction between the leuco dye and the developer can be changed to a discolored state.

[0088] [Other additives] The reversible thermochromic composition according to this embodiment may contain a color developer other than the compound (1) (hereinafter, sometimes referred to as "other color developers").

[0089] <Other color developers> The reversible thermochromic composition may contain other color developers to the extent that the effects of the present invention are not impaired. Any known color developers can be used as the other color developers, and although there are no particular limitations, an electron-accepting color developer is preferred. One type of other color developer may be used alone, or two or more types may be used in combination. When using other color developers, the amount used is preferably 1 to 5,000 parts by weight, more preferably 5 to 1,000 parts by weight, and even more preferably 10 to 500 parts by weight, relative to 100 parts by weight of the color developer containing the compound represented by formula (1). By using other color developers, it is possible to obtain a reversibly thermochromic composition that maintains high color development sensitivity and has improved decolorization properties.

[0090] Other color developers include monophenols and polyphenols, which may further have, as substituents, alkyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, carboxy groups and their esters, amide groups, halogen groups, etc. Other examples include bis- or tris-phenols, phenol-aldehyde condensation resins, etc. Furthermore, the color developers may be metal salts of compounds having a phenolic hydroxyl group.

[0091] Specific examples are given below. Phenol, o-cresol, t-butylcatechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, n-butyl p-hydroxybenzoate, n-octyl p-hydroxybenzoate, resorcinol, dodecyl gallate, 2,2-bis(4'-hydroxyphenyl)propane, 4,4-dihydroxydiphenyl sulfone, 1,1-bis(4'-hydroxyphenyl)ethane, 2,2-bis(4'-hydroxy-3-methylphenyl)propane, bis(4-hydroxyphenyl)sulfide, 1-phenyl-1,1-bis(4'-hydroxyphenyl)ethane, 1,1-bis(4'-hydroxyphenyl)-3-methylbutane, 1,1-bis(4'-hydroxyphenyl)-3-methylbutane, 2,2-bis(4'-hydroxyphenyl)-2-methylpropane, 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, 2,2-bis(4'-hydroxyphenyl)butane, 2,2-bis(4'-hydroxyphenyl)ethyl propionate, 2,2-bis(4'-hydroxyphenyl)-4-methylpentane, 2,2-bis(4'-hydroxyphenyl)hexafluoropropane, 2,2-bis(4'-hydroxyphenyl)n-heptane, and 2,2-bis(4'-hydroxyphenyl)n-nonane.

[0092] In addition, when a compound having a phenolic hydroxyl group that has at least three benzene rings and a molecular weight of 250 or more, preferably a molecular weight of 250 to 500, or a compound having a phenolic hydroxyl group represented by the following formula (20) is used as the compound having a phenolic hydroxyl group, the degree of color change between the colored state and the colorless state can be made more acute. [ka] (In formula (20), R18 is an alkyl group having 1 to 8 carbon atoms.

[0093] Examples of the compound having at least three benzene rings and a phenolic hydroxyl group with a molecular weight of 250 or more include 4,4',4"-methylidene trisphenol, 2,6-bis[(2-hydroxy-5-methylphenol)methyl]-4-methylphenol, 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol, 4,4',4"-ethylidene tris[2-methylphenol], 4,4'-[(2-hydroxyphenyl)methylene]bis[2,3,6-triphenyl 4,4'-[(4-hydroxyphenyl)methylene]bis[2-methylphenol], 4,4'-[(4-hydroxyphenyl)methylene]bis[2,6-dimethylphenol], 4,4'-[(4-hydroxyphenyl)methylene]bis[2,6-dimethylphenol], 4,4'-[(4-hydroxy-3-methoxy ... phenol], 2,4-bis[(5-methyl-2-hydroxyphenyl)methyl]-6-cyclohexylphenol, 4,4'-[1-[4-[1-(4-hydroxy-3-methylphenol)-1-methylethyl]phenyl]ethylidene]bis[2-methylphenol], 4,4'-[(4-hydroxyphenyl)methylene]bis[2-cyclohexyl-5-methylphenol], 4,6-bis[(4-hydroxyphenyl)methyl]1,3-benzenediol, 4,4'-[(3,4-dihydroxyphenyl)methylene]bis[2,6 -dimethylphenol], 4,4'-(1-phenylethylidene)bisphenol, 5,5'-(1-methylethylidene)bis[1-phenyl-2-ol], 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol, 4,4'-(phenylmethylene)bisphenol, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bis[2-methylphenol], 5,5'-(1,1-cyclohexylidene)bis-[1-biphenyl-2-ol], and the like.

[0094] Examples of the compound having a phenolic hydroxyl group represented by the formula (20) include bis(3-methyl-4-hydroxyphenyl) sulfide, bis(3,5-dimethyl-4-hydroxyphenyl), bis(3-ethyl-4-hydroxyphenyl) sulfide, bis(3,5-diethyl-4-hydroxyphenyl) sulfide, bis(3-propyl-4-hydroxyphenyl) sulfide, bis(3,5-dipropyl-4-hydroxyphenyl) sulfide, bis(3-t-butyl-4-hydroxyphenyl) sulfide, bis(3,5-t-butyl-4-hydroxyphenyl) sulfide, bis(3-pentyl-4-hydroxyphenyl) sulfide, bis(3-hexyl-4-hydroxyphenyl) sulfide, bis(3-heptyl-4-hydroxyphenyl) sulfide, and bis(5-octyl-2-hydroxyphenyl) sulfide.

[0095] The compound having a phenolic hydroxyl group is the most effective in exhibiting thermochromic properties, but other color developers may also be compounds selected from aromatic carboxylic acids and aliphatic carboxylic acids having 2 to 5 carbon atoms, carboxylic acid metal salts, acidic phosphate esters and their metal salts, 1,2,3-triazole and its derivatives, etc.

[0096] The reversible thermochromic composition according to the embodiment of the present invention may be encapsulated in microcapsules to form a microencapsulated pigment. When encapsulated in microcapsules, its functionality is not impaired even when it comes into contact with chemically active substances such as acidic substances, basic substances, and peroxides, or other solvent components. Furthermore, heat resistance stability can be maintained, and the composition of the reversible thermochromic composition remains the same under various usage conditions, thereby achieving the same effects.

[0097] The specific embodiment of the microcapsule pigment is not particularly limited, and reference can be made to, for example, Japanese Patent No. 6851787. Specifically, the microcapsule pigment can be produced by known methods such as interfacial polymerization, in situ polymerization, liquid curing coating, phase separation from an aqueous solution, phase separation from an organic solvent, melt-dispersion cooling, air suspension coating, and spray drying.

[0098] The average particle size of the microcapsule pigment is preferably 0.1 to 100 μm, and more preferably 3 to 30 μm. The particle size and particle size distribution are measured using a laser diffraction / scattering particle size distribution analyzer (LA-300, manufactured by Horiba, Ltd.), and the average particle size (median size) can be calculated on a volume basis based on the measured values.

[0099] The ratio of the inclusions to the wall film constituting the microcapsule pigment is preferably in the range of 7:1 to 1:1 (mass ratio) of inclusions:wall film. By keeping the ratio within this range, it is possible to prevent a decrease in color density and clarity during color development. More preferably, the ratio of the inclusions to the wall film is 6:1 to 1:1 (mass ratio) of inclusions:wall film.

[0100] The reversible thermochromic composition and microcapsule pigment according to the embodiments of the present invention can be used, for example, in printing inks, writing inks, paints, etc. Specifically, a reversible thermochromic layer can be formed on any support or dispersed in a support by printing means such as screen printing, offset printing, gravure printing, coater printing, pad printing, or transfer printing, or by coating means such as brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, or dip coating.

[0101] The reversible thermochromic composition or microcapsule pigment may also be contained in a writing instrument. The writing instrument includes a barrel containing a reversible thermochromic composition or a microencapsulated pigment, and a pen body that dispenses the reversible thermochromic composition or the microencapsulated pigment from the barrel. Examples of the pen body include a marking pen body, a ballpoint pen body, and a brush pen body. Examples of the marking pen body include a marking tip such as a fiber tip, a felt tip, or a plastic tip. Examples of the ballpoint pen body include a ballpoint pen tip.

[0102] The reversible thermochromic composition or microcapsule pigment may also be included in the toy. Specific examples of the above toys include dolls or animal-shaped toys, hair for dolls or animal-shaped toys, doll houses and furniture, doll accessories such as clothes, hats, bags and shoes, accessory toys, stuffed toys, drawing toys, toy picture books, puzzle toys such as jigsaw puzzles, building block toys, block toys, clay toys, fluid toys, tops, kites, musical instrument toys, cooking toys, gun toys, catching toys, background toys, vehicles, toys that resemble animals, plants, buildings and food.

[0103] In the above-mentioned toy, the form in which the reversible thermochromic composition or microcapsule pigment is contained is not particularly limited, and a reversible thermochromic layer can be formed on the surface of the toy by the above-mentioned printing means or painting means, or the reversible thermochromic composition or microcapsule pigment can be dispersed in the material that constitutes the toy. The method of using the toy is not particularly limited, but for example, the reversible thermochromic composition can be caused to change color by bringing the toy into contact with warm water or cold water. [Example]

[0104] The present invention will be described in detail below using examples and comparative examples, but the present invention is not limited to the following examples. In the following examples and comparative examples, "parts" and "%" mean "parts by weight" and "% by weight", respectively, unless otherwise specified.

[0105] <Synthesis Example 1> Synthesis of 4-methyl-N-(phenylaminocarbonyl)benzenesulfonamide [ka] Using aniline and p-toluenesulfonyl isocyanate as raw materials, the target product was obtained by the same procedure as in Patent Document 3 (Japanese Patent No. 2679459). The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:2.37(s,3H),6.98-7.02(m,1H),7.23-7.27(m,2H),7.31-7.33(m,2H),7.42(d,2H),7.85(d,2H),8.81(s,1H),10.68(brs,1H)

[0106] <Synthesis Example 2> Synthesis of 4-methyl-N-[[[4-fluorophenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 4-fluoroaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated methanol solvent were as follows: δ:2.43(s,3H),6.99(t,2H),7.31-7.34(m,2H),7.39(d,2H),7.90(d,2H)

[0107] <Synthesis Example 3> Synthesis of 4-methyl-N-[[[2-(trifluoromethyl)phenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-(trifluoromethyl)aniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated chloroform solvent were as follows: δ:2.47(s,3H),7.25-7.30(m,1H),7.36(d,2H),7.56(t,1H),7.66(d,1H),7.87(d,2H),7.99(d,1H),8.77(brs,1H)

[0108] <Synthesis Example 4> Synthesis of 4-methyl-N-[[[2-fluorophenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-fluoroaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated chloroform solvent were as follows: δ:2.47(s,3H),7.10-7.14(m,3H),7.36(d,2H),7.86(d,2H),8.00-8.03(m,1H),8.76(brs,1H)

[0109] <Synthesis Example 5> Synthesis of 4-methyl-N-[[[2,4-difluorophenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2,4-difluoroaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:2.38(s,3H),6.98-7.03(m,1H),7.27-7.32(m,1H),7.43(d,2H),7.71-7.78(m,1H),7.83(d,2H),8.56(s,1H),10.9(brs,1H)

[0110] <Synthesis Example 6> Synthesis of 4-methyl-N-[[[2-methylphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that o-toluidine (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated chloroform solvent were as follows: δ:2.24(s,3H),2.45(s,3H),7.07-7.12(m,1H),7.17-7.23(m,2H),7.34(d,2H),7.69(d,1H),7.85(d,2H),8.3(brs,1H),8.4(brs,1H)

[0111] <Synthesis Example 7> Synthesis of 4-methyl-N-[[[2,4-dimethylphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2,4-dimethylaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated chloroform solvent were as follows: δ:2.19(s,3H),2.29(s,3H),2.45(s,3H),6.98-7.02(m,2H),7.34(d,2H),7.45-7.50(m,1H),7.85(d,2H),8.1(brs,1H),8.2(brs,1H)

[0112] <Synthesis Example 8> Synthesis of 4-methyl-N-[[[2,5-dimethylphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2,5-dimethylaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:2.07(s,3H),2.19(s,3H),2.39(s,3H),6.80(d,1H),7.02(d,1H),7.41-7.44(m,3H),7.84(d,2H),7.99(s,1H),10.9(brs,1H)

[0113] <Synthesis Example 9> Synthesis of 4-methyl-N-[[[2,6-dimethylphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2,6-dimethylaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:1.99(s,6H),2.39(s,3H),6.98-7.07(m,3H),7.41(d,2H),7.82(d,2H),7.93(brs,1H),10.9(brs,1H)

[0114] <Synthesis Example 10> Synthesis of 4-methyl-N-[[[2-ethylphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-ethylaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated chloroform solvent were as follows: δ:1.21(t,3H),2.45(s,3H),7.12-7.24(m,3H),7.34(d,2H),7.63-7.70(m,1H),7.86(d,2H),8.37(brs,1H),8.53(brs,1H)

[0115] <Synthesis Example 11> Synthesis of 4-methyl-N-[[[2-isopropylphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-isopropylaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated chloroform solvent were as follows: δ:1.22(d,6H),2.46(s,3H),2.97(m,1H),7.17-7.23(m,2H),7.27-7.32(m,1H ),7.35(d,2H),7.52-7.57(m,1H),7.86(d,2H),8.23(brs,1H),8.34(brs,1H)

[0116] <Synthesis Example 12> Synthesis of 4-methyl-N-[[[2-butylphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-butylaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated chloroform solvent were as follows: δ:0.94(t,3H),1.37-1.41(m,2H),1.53-1.57(m,2H),2.45(s,3H),2.57(t,2H),7.09-7.15(m,1H ),7.17-7.22(m,2H),7.34(d,2H),7.65-7.70(m,1H),7.84(d,2H),8.15(brs,1H),8.42(brs,1H)

[0117] <Synthesis Example 13> Synthesis of 4-methyl-N-[[[2-methoxyphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-methoxyaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:2.38(s,3H),3.83(s,3H),6.85-6.87(m,1H),6.99-7.00(m,2H),7.43(d,2H),7.82-7.85(m,3H),8.39(s,1H),11.0(brs,1H)

[0118] <Synthesis Example 14> Synthesis of 4-methyl-N-[[[2-ethoxyphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-ethoxyaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:1.38(t,3H),2.39(s,3H),4.07(q,2H),6.83-6.85(m,1H),6.96-6.99(m,2H),7.43(d,2H),7.83-7.88(m,3H),8.32(s,1H),11.3(brs,1H)

[0119] <Synthesis Example 15> Synthesis of 4-methyl-N-[[[2-methoxy-5-methylphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-methoxy-5-methylaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:2.17(s,3H),2.39(s,3H),3.79(s,3H),6.78-6.80(m,1H),6.88(d,1H),7.43(d,2H),7.69(s,1H),7.83(d,2H),8.33(s,1H),11.1(brs,1H)

[0120] <Synthesis Example 16> Synthesis of 4-methyl-N-[[[2,5-dimethoxyphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2,5-dimethoxyaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated chloroform solvent were as follows: δ:2.43(s,3H),3.76(s,3H),3.92(s,3H),6.60(dd,1H),6.83(d,1H),7.32(d,2H),7.67(brs,1H),7.76(d,1H),7.86(d,2H),9.09(brs,1H)

[0121] <Synthesis Example 17> Synthesis of 4-methyl-N-[[[2,4-dimethoxyphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2,4-dimethoxyaniline (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:2.38(s,3H),3.70(s,3H),3.81(s,3H),6.42(dd,1H),6.59(d,1H),7.42(d,2H),7.66(d,1H),7.82(d,2H),8.16(s,1H),10.9(brs,1H)

[0122] <Synthesis Example 18> Synthesis of 4-methyl-N-[[[2-(pentylcarbonyloxy)phenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-(pentylcarbonyloxy)aniline (synthesized with reference to a non-patent document (Bioorganic & Medicinal Chemistry Letters, 2006, vol. 16, pp. 1160-1163)) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated chloroform solvent were as follows: δ:0.92(t,3H,J=7.2Hz),1.35-1.45(m,4H),1.75-1.85(m,2H),2.74(t,2H,J=7.2Hz),7.1-7.25( m,3H),7.32(d,2H,J=8.4Hz),7.78(d,2H,J=8.4Hz),7.98(s,1H),8.09(d,1H,7.6Hz),8.96(s,1H)

[0123] <Synthesis Example 19> Synthesis of 4-methyl-N-[[[4-hexyloxy-2-methylphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 4-hexyloxy-2-methylaniline (synthesized with reference to Patent Document (US2015 / 0152049A1)) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated chloroform solvent were as follows: δ:0.91(t,3H),1.30-1.37(m,4H),1.42-1.48(m,2H),1.73-1.80(m,2H),2.18(s,3H),2. 46(s,3H),3.92(t,2H),6.69-6.77(m,2H),7.35-7.45(m,4H),7.86(d,2H),8.17(brs,1H)

[0124] <Synthesis Example 20> Synthesis of 4-methyl-N-[[[2-methyl-(4-pentylcarbonyloxy)phenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-methyl-(4-pentylcarbonyloxy)aniline (synthesized with reference to Patent Document (WO2010 / 120382A1)) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated chloroform solvent were as follows: δ:0.94(t,3H),1.35-1.45(m,4H),1.72-1.80(m,2H),2.21(s,3H),2.45(s,3H),2.55(t,2H) ),6.88-6.91(m,2H),7.35(d,2H),7.69(d,1H),7.84(d,2H),8.06(brs,1H),8.27(brs,1H)

[0125] <Synthesis Example 21> Synthesis of 4-methyl-N-[[[4-(4-t-butylphenylcarbonyloxy)-2-methylphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 4-(4-t-butylphenylcarbonyloxy)-2-methylaniline (synthesized with reference to Patent Document (WO2010 / 120382A1)) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:1.32(s,9H),2.14(s,3H),2.40(s,3H),7.00-7.05(m,1H),7.09(d,1H,J=3.2Hz),7.43(d,2H,J=8 .4Hz),7.59-7.62(m,3H),7.86(d,2H,J=8.4Hz),8.03(d,2H,J=7.6Hz),8.15(s,1H),10.9(brs,1H)

[0126] <Synthesis Example 22> Synthesis of 4-methyl-N-[[[2-methyl-(3-hexyloxycarbonyl)phenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-methyl-(3-hexyloxycarbonyl)aniline (synthesized with reference to Non-Patent Document (Macromolecules 2018, Vol. 51 (No. 19), pp. 7800-7806)) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:0.86(t,3H,J=6.8Hz),1.25-1.4(m,6H),1.6-1.7(m,2H),2.21(s,3H),2.39(s,3H),4.22(t,2H,J=6.8Hz), 7.2-7.25(m,1H),7.4-7.47(m,3H),7.64(d,1H,J=8.0Hz),7.84(d,2H,J=8.4Hz),8.28(s,1H),11.0(brs,1H)

[0127] <Synthesis Example 23> Synthesis of 4-methyl-N-[[[3-(4-t-amylphenyloxycarbonyl)-2-methylphenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 3-(4-t-amylphenyloxycarbonyl)-2-methylaniline (synthesized with reference to patent document (EP1462485A1)) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:0.65(t,3H,J=7.2Hz),1.26(s,6H),1.63(q,2H,J=7.2Hz),2.35(s,3H),2.37(s,3H),7.19(d,2H,J=8.4Hz),7.2-7.3(m ,1H),7.30(d,2H,J=8.4Hz),7.40(d,2H,J=8.8Hz),7.61(d,1H,J=7.6Hz),7.76(d,2H,J=8.0Hz),7.84(m,1H),8.04(s,1H)

[0128] <Synthesis Example 24> Synthesis of 4-methyl-N-[[[2-methyl-(4-hexyloxycarbonyl)phenyl]amino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that 2-methyl-(4-hexyloxycarbonyl)aniline (synthesized with reference to Non-Patent Document (Macromolecules 2018, Vol. 51 (No. 19), pp. 7800-7806)) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:0.85(t,3H,J=7.2Hz),1.2-1.4(m,6H),1.6-1.7(m,2H),2.21(s,3H),2.39(s,3H),4.21(t,2H) ,J=6.8Hz),7.43(d,2H,8.0Hz),7.7-7.77(m,2H),7.84-7.9(m,3H),8.22(s,1H),11.1(brs,1H)

[0129] <Synthesis Example 25> Synthesis of N-(p-toluenesulfonyl)-N'-(3-p-toluenesulfonyloxyphenyl)urea [ka] The target compound was obtained by the same procedure as in Synthesis Example 4 of Patent Document (Patent No. 4601174). The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:2.40(s,6H),6.57-6.61(m,1H),7.18-7.26(m,3H),7.44(d,4H,J=8.4Hz ),7.72(d,2H,J=8.4Hz),7.85(d,2H,J=8.4Hz),9.09(s,1H),10.8(brs,1H)

[0130] <Synthesis Example 26> Synthesis of 4-methyl-N-[[isopropylamino]carbonyl]benzenesulfonamide [ka] The target product was obtained by the same procedure as in Synthesis Example 1, except that isopropylamine (purchased from Tokyo Chemical Industry Co., Ltd.) was used in place of aniline in the same molar ratio. The chemical shifts (δ ppm) in the proton NMR spectrum (400 MHz) measured in deuterated DMSO solvent were as follows: δ:0.99(d,6H,J=6.8Hz),2.39(s,3H),3.5-3.65(m,1H),6.27(d,1H,J=7.6Hz),7.40(d,2H,J=8.4Hz),7.77(d,2H,J=8.4Hz)

[0131] <Comparative Example 1> A reversible thermochromic composition was obtained by mixing 1 part of 2'-(2-chloroanilino)-6'-(dibutylamino)fluoran as a leuco dye, 4 parts of 1,3-diphenylurea (purchased from Tokyo Chemical Industry Co., Ltd.) as a color developer, and 25 parts of 4-benzyloxyphenylethyl caprate as a color change temperature regulator.

[0132] <Comparative Example 2> A reversible thermochromic composition was obtained in the same manner as in Comparative Example 1, except that 4 parts of 1,3-diphenylthiourea (purchased from Tokyo Chemical Industry Co., Ltd.) was used as the color developer.

[0133] Example 1 A reversible thermochromic composition was obtained by mixing 1 part of 2'-(2-chloroanilino)-6'-(dibutylamino)fluoran as a leuco dye, 4 parts of 4-methyl-N-(phenylaminocarbonyl)benzenesulfonamide as a color developer, and 25 parts of 4-benzyloxyphenylethyl caprate as a color change temperature regulator.

[0134] <Example 2> A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 2 was used as the developer.

[0135] Example 3 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 3 was used as the developer.

[0136] Example 4 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 4 was used as the developer.

[0137] <Example 5> A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 5 was used as the developer.

[0138] Example 6 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 6 was used as the developer.

[0139] Example 7 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 7 was used as the developer.

[0140] Example 8 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 8 was used as the developer.

[0141] Example 9 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 9 was used as the developer.

[0142] Example 10 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 10 was used as the developer.

[0143] Example 11 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 11 was used as the developer.

[0144] Example 12 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 12 was used as the developer.

[0145] Example 13 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 13 was used as the developer.

[0146] Example 14 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 14 was used as the developer.

[0147] Example 15 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 15 was used as the developer.

[0148] Example 16 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 16 was used as the developer.

[0149] Example 17 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 17 was used as the developer.

[0150] Example 18 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 18 was used as the developer.

[0151] Example 19 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 19 was used as the developer.

[0152] Example 20 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 20 was used as the developer.

[0153] <Example 21> A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 21 was used as the developer.

[0154] <Example 22> A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 22 was used as the developer.

[0155] Example 23 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 23 was used as the developer.

[0156] Example 24 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 24 was used as the developer.

[0157] Example 25 A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 25 was used as the developer.

[0158] <Example 26> A reversible thermochromic composition was obtained in the same manner as in Example 1, except that the compound obtained in Synthesis Example 26 was used as the developer.

[0159] <Comparative Example 3> A composition was obtained in the same manner as in Example 3, except that no discoloration temperature regulator was used.

[0160] <Comparative Example 4> A composition was obtained in the same manner as in Example 6, except that no discoloration temperature regulator was used.

[0161] <Comparative Example 5> A composition was obtained in the same manner as in Example 12, except that no discoloration temperature regulator was used.

[0162] <Color development sensitivity> 30 parts of each composition obtained in the comparative examples and examples was dissolved in 120 parts of methyl ethyl ketone, and then the solution was applied to fine paper (Shirogane, manufactured by Nippon Paper Papylia Co., Ltd.) and left to cure overnight to prepare measurement samples. The image density of the prepared measurement samples was measured using an X-Rite spectrodensitometer / colorimeter (eXact). The results are shown in Tables 1 to 3. Note that the higher the image density value in this test, the better the color development sensitivity.

[0163] <Decolorization> The prepared measurement samples were pressed for 5 seconds at a heat source temperature of 70°C or 90°C using a thermal paper static color tester manufactured by Okura Engineering Co., Ltd., and the decolorization property was evaluated visually after the heat source was removed. The results are shown in Tables 1 to 3. The symbols used in the decolorization property evaluation in this test are explained below. A: Significant discoloration is observed compared to the sample before heat source compression. B: Discoloration is observed compared to the sample before heat source compression. C: Some discoloration is observed compared to the sample before heat source compression. D: No difference was observed compared to the sample before heat source pressing.

[0164] [Table 1] [Table 2] [Table 3]

[0165] As is clear from Tables 1 to 3, the compounds described in Examples 1 to 26 have improved reactivity of the urea group due to the presence of a sulfonyl group compared to Comparative Examples 1 and 2. This improves compatibility with discoloration temperature regulators and provides satisfactory erasability while maintaining sufficient image density. Furthermore, the compounds described in Examples 3 to 24 have a substituent at the ortho-position of the benzene ring adjacent to the NH group of the sulfonylurea group, which facilitates dissociation from the leuco dye due to steric hindrance, thereby providing even more excellent erasability. Even when A is an alkyl group in formula (1), as in the compound described in Example 26, weakening the proton character of the NH group of the sulfonylurea group facilitates dissociation from the leuco dye, providing excellent erasability. Therefore, the compound described in the present application exhibits excellent color development properties when reacted with a leuco dye via the sulfonylurea group, and also exhibits excellent decolorization properties because it can be dissociated from the leuco dye by utilizing its compatibility with a discoloration temperature regulator and steric hindrance, and therefore exhibits excellent effects as a color developer for a non-phenolic reversible thermochromic composition. Furthermore, as is clear from Table 3, when no discoloration temperature regulator is contained, no decolorization is exhibited.

Claims

1. Sulfonylurea (—NH—CO—NH—SO) represented by the following formula (1) ２ A reversible thermochromic composition comprising a developer containing a compound having a -) moiety, a leuco dye, and a color-change temperature regulator. 【Chemistry 1】 (In the above formula (1), A is an aryl group or a heteroaryl group which may have a substituent, A has a substituent R 0 other than a hydrogen atom, and R 0 is bonded at the o-position to the NH group adjacent to A. However, A is not R ０ The R 0 may have a substituent other than the above. The R 0 is a halogen atom, a nitrile group, a carboxyl group, or an alkyl group, aryl group, heteroaryl group, ether group, thioether group, oxycarbonyl group, carbonyloxy group, carbonyl group, amino group, carbonylamino group, aminocarbonyl group, urea group, sulfonylamido group, sulfinyl group, sulfonyl group, or sulfonyloxy group, which may have a substituent. The substituent other than R 0 is at least one selected from the group consisting of a fluoro group, a chloro group, and an alkyl group, aryl group, ether group, thioether group, carbonyl group, oxycarbonyl group, carbonyloxy group, and sulfonyloxy group, which may have a substituent. B is an aryl group, heteroaryl group, or alkyl group, which may have a substituent.

2. The R ０ The reversible thermochromic composition according to claim 1, wherein is a fluoro group or an alkyl group having at least one fluoro group.

3. A microcapsule in which the reversible thermochromic composition according to claim 1 is encapsulated. Cell pigment.

4. A writing implement containing the reversible thermochromic composition according to claim 1 or 2 or the microcapsule pigment according to claim 3.

5. A toy comprising the reversible thermochromic composition according to claim 1 or 2 or the microcapsule pigment according to claim 3.

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