JP2006263921A - Thermochromism writing utensil set - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a writing utensil set so convenient that a holograph with a writing utensil is constituted not to be visually judged by a colored transparent sheet and the holograph can be easily erased when unnecessary and writing can be performed again with the writing utensil to the erased portion of the holograph. <P>SOLUTION: This thermochromism writing utensil set is formed by dispersing in a vehicle a microcapsulated pigment comprising a reversible thermochromism composition consisting of (α) an electron donative colorable organic compound, (β) an electron acceptive compound and (γ) a reacting medium controlling the color reaction between (α) and (β) and changes color from a colored state to a colorless state, and comprises a writing utensil housing a reversible thermochromism ink having the microcapsulated pigment under its colored state and the colored transparent sheet under the condition that the hue shown by the ink is the same color as the hue of the sheet or the colored hue shown by the ink is included in the structural color obtained by subtractive color blending of the hue of the sheet. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermochromic writing instrument set. More particularly, the present invention relates to a thermochromic writing instrument set comprising a writing instrument that gives a handwriting that changes color from colorless to colorless according to a temperature change, and a sheet that renders the colored handwriting invisible.

Conventionally, a writing instrument containing ink containing a general colorant and a learning tool composed of a colored transparent sheet having the same color relationship as the color tone of the ink have been disclosed (for example, see Patent Document 1).
Although the learning tool is a learning tool suitable for memorization when a colored transparent film is placed on a handwriting obtained by writing with a writing tool and visually observed, the handwriting cannot be erased. . As a result, the handwriting that was no longer needed remained forever, and the content that had been memorized could hinder studying or prevented the formation of another handwriting.
As a method for solving the above-described problem, a color-changing ink using a dye that changes color or decolors with a reducing agent as a colorant is disclosed (for example, see Patent Document 1).
The handwriting formed by the writing instrument incorporating the ink can be discolored or decolored by applying a color changing liquid from above, but even if an attempt is made to form the handwriting again with the writing tool once erased, Since the components in the erasing liquid remained, there was a problem that the handwriting could not be formed and could not be used repeatedly.
JP 57-37389 A Japanese Patent Publication No.54-22345

  As a result of further study on the learning tool composed of the writing instrument and the colored transparent sheet, the present invention is suitable for memorization and convenience by using ink that changes color from colorless to colorless by temperature change as ink contained in the writing instrument. We found that learning tools with excellent and high commercial value can be obtained.

〔式中、Ｒ_１は水素原子又はメチル基を示し、ｍは０〜２の整数を示し、Ｘ_１、Ｘ_２のいずれか一方は−（ＣＨ_２）_ｎＯＣＯＲ_２又は−（ＣＨ_２）_ｎＣＯＯＲ_２、他方は水素原子を示し、ｎは０〜２の整数を示し、Ｒ_２は炭素数４以上のアルキル基又はアルケニル基を示し、Ｙ_１及びＹ_２は水素原子、炭素数１〜４のアルキル基、メトキシ基、又は、ハロゲンを示し、ｒ及びｐは１〜３の整数を示す。〕

〔式中、Ｒは炭素数８以上のアルキル基又はアルケニル基を示す。〕
摩擦体を備えてなること、筆記具に摩擦体が装着されてなること、摩擦体は、ゴム又はプラスチック発泡体であること等を要件とする。 The present invention comprises (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that controls the color reaction of (a) and (b). A writing instrument containing a reversible thermochromic ink in which the microcapsule pigment is dispersed in a vehicle, the microcapsule pigment changing color from colorless to colorless by temperature change encapsulating the reversible thermochromic composition; A colored transparent sheet, and the colored hue exhibited by the reversible thermochromic ink and the hue of the colored transparent sheet are the same, or the colored hue exhibited by the reversible thermochromic ink is the hue of the colored transparent sheet. A thermochromic writing instrument set included as a constituent color by subtractive color mixing is required.
Furthermore, the microcapsule pigment exhibits a large hysteresis characteristic with respect to the color density-temperature curve, exhibits tautomerism between the first hue and the second hue, and has a two-phase holding temperature range in which both phases can coexist in the normal temperature range. a pigment, wherein the pigment is in the process of temperature in the first color state is increased and reaches the second temperature T _3, the first color begins to discolor, the second temperature T ₃ higher than the temperature T ₄ In the above temperature range, the second hue is completely changed to the second hue state, and in the process of decreasing the temperature in the second hue state, when the first temperature T ₂ lower than the second temperature T ₃ is reached, the second hue changes color. was started, become completely the first color at a first low temperature T ₁ of the following temperature range than temperature T _2, a first color at a temperature range between the first temperature T ₂ and the second temperature T ₃ It exhibits hysteresis characteristics in which both phases of the second hue can coexist, and the temperature T ₁ is −3 The reaction medium for controlling the color reaction of (A) and (B) above is in the range of 0 to 0 ° C. and the temperature T ₄ is in the range of 40 to 80 ° C. The following formula (1) or (2) A compound represented by

[Wherein, R ₁ represents a hydrogen atom or a methyl group, m represents an integer of 0 to 2, and _one of X ₁ and X ₂ represents — (CH ₂ ) _n OCOR ₂ or — (CH ₂ ) _n COOR ₂ , the other represents a hydrogen atom, n represents an integer of 0 to 2, R ₂ represents an alkyl or alkenyl group having 4 or more carbon atoms, Y ₁ and Y ₂ represent a hydrogen atom, 1 to 4 carbon atoms An alkyl group, a methoxy group, or halogen, and r and p each represent an integer of 1 to 3. ]

[Wherein, R represents an alkyl group or an alkenyl group having 8 or more carbon atoms. ]
It is required that the friction body is provided, the friction body is attached to the writing instrument, and that the friction body is rubber or plastic foam.

  The present invention forms an arbitrary handwriting with a writing instrument, the handwriting is configured so as not to be visually discernable by a colored transparent sheet, and can provide an unexpected property that the handwriting can be easily erased when it is not needed, and the erased portion is again A thermochromic writing instrument set that is excellent in convenience of writing using the writing instrument and is suitable for memorizing learning and learning elements can be provided.

The microcapsule pigments contained in the ink are conventionally known (i) electron-donating color-forming organic compounds, (b) electron-accepting compounds, and (c) reactions that determine the temperature at which the color reaction of the two occurs. A pigment in which a reversible thermochromic composition containing at least three essential components of a medium is encapsulated in a microcapsule is effective.
Among the reversible thermochromic compositions, the compositions that can be decolored by heating are described in JP-B-51-44706, JP-B-51-44707, JP-B-1-29398, and the like. The color changes before and after the temperature (discoloration point), shows a decolored state in the temperature range above the high temperature side discoloration point, and develops a color state in the temperature range below the low temperature side discoloration point. There is only one specific state, and the other state is maintained while the heat or cold required to develop that state is applied, but if the heat or cold is no longer applied, The composition which has the characteristic ((DELTA) H = 1-7 degreeC) with a comparatively small hysteresis width | variety which returns to the state exhibited in a region can be illustrated.
In addition, large hysteresis characteristics described in JP-B-4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, JP-A-2005-1369, and the like. (ΔH = 8 to 70 ° C.), and the shape of the curve plotting the change in color density due to the temperature change is from the higher temperature side than the color change temperature range, contrary to the case where the temperature is raised from the lower temperature side than the color change temperature range. Use a reversible thermochromic composition that changes color by following a path that differs greatly from that of lowering, and can store and retain the color development state in the low temperature range or the decoloration state in the high temperature range in the specific temperature range. You can also.

The hysteresis characteristic in the color density-temperature curve of the composition will be described in detail.
In FIG. 1, the vertical axis represents color density and the horizontal axis represents temperature. The change in color density due to the temperature change proceeds along the arrow. Here, A is a point indicating the density at the lowest temperature T ₄ (hereinafter referred to as the complete color erasing temperature) reaching the complete color erasing state, and B is the maximum temperature T ₃ (hereinafter referred to as the color erasing) capable of maintaining the complete color development state. C is a point indicating the density at the lowest temperature T ₂ (hereinafter referred to as a color development start temperature) at which a completely decolored state can be maintained, and D reaches a complete color development state. This is a point indicating the density at the maximum temperature T ₁ (hereinafter referred to as a complete color development temperature).
Discoloration temperature region is a temperature region between the T ₁ and T _4, the first hue and can co-exist two phases of the second color, the temperature range between T ₂ and T ₃ is a large area of the difference in color density Is a substantial discoloration temperature range (two-phase holding temperature range).
The length of the line segment EF is a scale indicating the discoloration contrast, and the length of the line segment HG passing through the midpoint of the line segment EF is a temperature width indicating the degree of hysteresis (hereinafter referred to as hysteresis width ΔH). If this ΔH value is small, only one specific state can exist in the normal temperature range among both states before and after the color change. Further, when the ΔH value is large, it is easy to maintain each state before and after the color change.

  Further, as a heat-developable reversible thermochromic composition, a specific alkoxyphenol compound having a linear or side chain alkyl group having 3 to 18 carbon atoms as an electron-accepting compound that develops color when heated from a decolored state (Applications of JP-A-11-129623, JP-A-11-5973), systems to which specific hydroxybenzoates are applied (JP-A-2001-105732), systems to which gallic acid esters are applied (Japanese Patent Publication No. 51-44706) can be exemplified.

By using a reversible thermochromic composition having a color memory property among the above-described compositions, the color can be easily changed from the first state (colored) to the second state (colorless). And different colors can be seen interchangeably.
Specifically, the complete color development temperature T ₁ is a temperature that can be obtained only in a freezing room, a cold district, etc., that is, −30 to 0 ° C., preferably −30 to −5 ° C., more preferably −30 to −10 ° C. and, the complete decoloring temperature _{T 4} frictional heat generated by friction body, the temperature obtained from the hair dryer familiar heating body, i.e. 40 to 80 ° C., preferably 50 to 80 ° C., and more preferably in the range of 60-80 ° C. By specifying and specifying the ΔH value of 40 to 60 ° C., it is possible to effectively function to maintain the color exhibited in the normal state (daily life temperature range).
The present invention is a writing instrument containing an ink containing a microcapsule pigment encapsulating a reversible thermochromic composition in a colored state, and preferably has a configuration in which handwriting formed by the writing instrument is not discolored by finger touch or the like. . Moreover, it is preferable that the erased handwriting does not appear again.
Therefore, the above-described temperature setting of T ₁ and T ₄ is an extremely important requirement.

Specific examples of the compounds (a), (b) and (c) are shown below.
As the component (a) of the present invention, that is, the electron-donating color-forming organic compound, conventionally known diphenylmethane phthalides, phenyl indolyl phthalides, indolyl phthalides, diphenyl methane azaphthalides, phenyl in Examples thereof include drill azaphthalides, fluorans, styrinoquinolines, diazarhodamine lactones, and the like.
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-diphenylaminofluorane, 3,6-dimethoxyfluorane, 3,6-di -N-butoxyfluorane, 2-methyl-6- (N-ethyl-Np-tolylamino) fluorane, 3-chloro-6-cyclohexylaminofluorane, 2-methyl -6-cyclohexylaminofluorane, 2- (2-chloroanilino) -6-di-n-butylaminofluorane, 2- (3-trifluoromethylanilino) -6-diethylaminofluorane, 2- (N- Methylanilino) -6- (N-ethyl-Np-tolylamino) fluorane, 1,3-dimethyl-6-diethylaminofluorane, 2-chloro-3-methyl-6-diethylaminofluorane, 2-anilino-3- Methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6-di-n-butylaminofluorane, 2-xylidino-3-methyl-6-diethylaminofluorane, 1,2-benz-6-diethylamino Fluorane, 1,2-benz-6- (N-ethyl-N-isobutylamino) fluorane, 1,2-benz-6 N-ethyl-N-isoamylamino) fluorane, 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) pyrimidine-5,1' (3′H) isobenzofuran] -3′-one, 2- (di-n-butylamino) -8- (di-n-butylamino) -4-methyl-, spiro [5H- (1) benzopyrano ( 2,3-d) pyrimidine-5,1 '(3'H) isobenzofuran] -3'-one, 2- (di-n-butylamino) -8- (diethylamino) -4-methyl-, spiro [ 5H- (1) benzopyrano (2, 3-d) Pyrimidine-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) pyrimidine-5,1 '(3'H) isobenzofuran] -3'-one, 2- (di-n-butylamino)- 8- (Di-n-butylamino) -4-phenyl, 3- (2-methoxy-4-dimethylaminophenyl) -3- (1-butyl-2-methylindol-3-yl) -4,5 6,7-tetrachlorophthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4,5,6,7-tetrachlorophthalide 3- (2-ethoxy-4-diethylaminophenyl) 3- (1-pentyl-2-methylindole-3-yl) -4,5,6,7 can be given tetrachloro phthalide like.
Furthermore, there can be mentioned pyridine-based, quinazoline-based, bisquinazoline-based compounds and the like that are effective in developing fluorescent yellow to red color development.

As the electron-accepting compound of component (b), a group of compounds having active protons, a group of pseudo-acidic compounds (a group of compounds that are not acids but act as an acid in the composition and cause component (a) to develop color), electrons There is a group of compounds having pores.
Examples of compounds having active protons include monophenols to polyphenols as compounds having phenolic hydroxyl groups, and alkyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, carboxy groups and esters thereof as substituents. Or what has an amide group, a halogen group, etc., phenol-aldehyde condensation resin etc., such as a bis type and a tris type phenol, are mentioned. Moreover, the metal salt of the compound which has the said phenolic hydroxyl group may be sufficient.

（式中、Ｒは炭素数１乃至８のアルキル基を示す。）
前記少なくとも３以上のベンゼン環を有し、且つ、分子量が２５０以上のフェノール性水酸基を有する化合物としては、
４，４′，４″−メチリデントリスフェノール、
２，６−ビス〔（２−ヒドロキシ−５−メチルフェノール）メチル〕−４−メチルフェノール、
４，４′−〔１−［４−［１−（４−ヒドロキシフェニル）−１−メチルエチル］フェニル］エチリデン〕ビスフェノール、
４，４′，４″−エチリデントリス〔２−メチルフェノール〕、
４，４′−〔（２−ヒドロキシフェニル）メチレン〕ビス［２，３，６−トリフェニルフェノール］、
２，２−メチレンビス［６−［（２−ヒドロキシ−５−メチルフェニル）メチル］−４−メチルフェノール］、
２，４，６−トリス（４−ヒドロキシフェニルメチル）１，３−ベンゼンジオール、
４，４′，４″−エチリデントリスフェノール、
４，４′−［（４−ヒドロキシフェニル）メチレン］ビス［２−メチルフェノール］、
４，４′−［（４−ヒドロキシフェニル）メチレン］ビス［２，６−ジメチルフェノール］、
４，４′−［（４−ヒドロキシフェニル）メチレン］ビス［２−メチルフェノール］、
４，４′−［（４−ヒドロキシフェニル］メチレン］ビス［２，６−ジメチルフェノール］、
４，４′−［（４−ヒドロキシ−３−メトキシフェニル）メチレン］ビス［２，６−ジメチルフェノール］、
２，４−ビス［（５−メチル−２−ヒドロキシフェニル）メチル］−６−シクロヘキシルフェノール、
４，４′−［１−［４−［１−（４−ヒドロキシ−３−メチルフェノール）−１−メチルエチル］フェニル］エチリデン］ビス［２−メチルフェノール］、
４，４′−［（４−ヒドロキシフェニル）メチレン］ビス［２−シクロヘキシル−５−メチルフェノール］、
４，６−ビス［（４−ヒドロキシフェニル）メチル］１，３−ベンゼンジオール、
４，４′−［（３，４−ジ−ヒドロキシフェニル）メチレン］ビス［２，６−ジメチルフェノール］、
４，４′−（１−フェニルエチリデン）ビスフェノール、
５，５′−（１−メチルエチリデン）ビス［１−フェニル−２−オール］、
４，４′，４″−メチリデントリスフェノール、
４，４′−［１−［４−［１−（４−ヒドロキシフェニル）−１−メチルエチル］フェニル］エチリデン］ビスフェノール、
４，４′−（フェニルメチレン）ビスフェノール、
４，４′−［１，４−フェニレンビス（１−メチルエチリデン）］ビス［２−メチルフェノール］、
５，５′−（１，１−シクロヘキシリデン）ビス−［１−ビフェニル−２−オール］等が挙げられる。
前記式（３）で示されるフェノール性水酸基を有する化合物としては、
ビス（３−メチル−４−ヒドロキシフェニル）スルフィド、ビス（３，５−ジメチル−４−ヒドロキシフェニル）、ビス（３−エチル−４−ヒドロキシフェニル）スルフィド、ビス（３，５−ジエチル−４−ヒドロキシフェニル）スルフィド、ビス（３−プロピル−４−ヒドロキシフェニル）スルフィド、ビス（３，５−ジプロピル−４−ヒドロキシフェニル）スルフィド、ビス（３−ｔ−ブチル−４−ヒドロキシフェニル）スルフィド、ビス（３，５−ｔ−ブチル−４−ヒドロキシフェニル）スルフィド、ビス（３−ペンチル−４−ヒドロキシフェニル）スルフィド、ビス（３−ヘキシル−４−ヒドロキシフェニル）スルフィド、ビス（３−ヘプチル−４−ヒドキシフェニル）スルフィド、ビス（５−オクチル−２−ヒドロキシフェニル）スルフィド等が挙げられる。
前記フェノール性水酸基を有する化合物が最も有効な熱変色特性を発現させることができるが、芳香族カルボン酸及び炭素数２〜５の脂肪族カルボン酸、カルボン酸金属塩、酸性リン酸エステル及びそれらの金属塩、１、２、３−トリアゾール及びその誘導体から選ばれる化合物等であってもよい。 Specific examples are given below.
Phenol, o-cresol, tertiary butylcatechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, n-butyl p-hydroxybenzoate N-octyl p-hydroxybenzoate, resorcin, dodecyl gallate, 2,2-bis (4-hydroxyphenyl) propane, 4,4-dihydroxydiphenylsulfone, 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-methylbu 1,1-bis (4-hydroxyphenyl) -2-methylpropane, 1,1-bis (4-hydroxyphenyl) n-hexane, 1,1-bis (4-hydroxyphenyl) n-heptane, , 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) ethylpropionate, 2,2-bis (4-hydroxyphenyl)- 4-methylpentane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 2,2-bis (4-hydroxyphenyl) n-heptane, 2,2-bis It is 4-hydroxyphenyl) n- nonane.
As the compound having a phenolic hydroxyl group, a compound having a phenolic hydroxyl group having at least three benzene rings and having a molecular weight of 250 or more, preferably a molecular weight of 250 to 500, or the following formula (3) When the compound having a phenolic hydroxyl group represented by is used, it is possible to make the color change sensitivity when shifting from the decolored state to the colored state more sensitive. Specifically, discoloration behavior when reaching the temperature (T ₁₎ indicating the complete coloring temperature via the temperature (T ₂₎ to start the coloring from the temperature (T ₄₎ showing complete decolored state as shown in FIG. 2 in the temperature to start the color development (T ₂₎ showed no behavior that develops color gradually shifted to the high temperature side, the temperature indicating the complete coloring temperature and the temperature (T ₂₎ to start the color development as in FIG. 1 (T ₁ ) The temperature difference is small, and it becomes easy to show a behavior that shifts sharply from the decolored state to the colored state.

(In the formula, R represents an alkyl group having 1 to 8 carbon atoms.)
As the compound having at least 3 or more benzene rings and having a phenolic hydroxyl group having a molecular weight of 250 or more,
4,4 ', 4 "-methylidenetrisphenol,
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-triphenylphenol],
2,2-methylenebis [6-[(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol],
2,4,6-tris (4-hydroxyphenylmethyl) 1,3-benzenediol,
4,4 ', 4 "-ethylidene trisphenol,
4,4 '-[(4-hydroxyphenyl) methylene] bis [2-methylphenol],
4,4 '-[(4-hydroxyphenyl) methylene] bis [2,6-dimethylphenol],
4,4 '-[(4-hydroxyphenyl) methylene] bis [2-methylphenol],
4,4 '-[(4-hydroxyphenyl] methylene] bis [2,6-dimethylphenol],
4,4 '-[(4-hydroxy-3-methoxyphenyl) methylene] bis [2,6-dimethylphenol],
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-di-hydroxyphenyl) methylene] bis [2,6-dimethylphenol],
4,4 '-(1-phenylethylidene) bisphenol,
5,5 ′-(1-methylethylidene) bis [1-phenyl-2-ol],
4,4 ', 4 "-methylidenetrisphenol,
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.
As the compound having a phenolic hydroxyl group represented by the formula (3),
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-hydride) Xylphenyl) sulfide, bis (5-octyl-2-hydroxyphenyl) Rufido, and the like.
The compound having a phenolic hydroxyl group can develop the most effective thermochromic property, but aromatic carboxylic acids and aliphatic carboxylic acids having 2 to 5 carbon atoms, carboxylic acid metal salts, acidic phosphate esters and their It may be a compound selected from metal salts, 1,2,3-triazole and derivatives thereof.

The component (c) of the reaction medium that causes the electron transfer reaction by the components (a) and (b) to occur reversibly in a specific temperature range will be described. Examples of the component (c) include alcohols, esters, ketones, ethers, and acid amides.
The component (c) is preferably a large hysteresis characteristic regarding the color density-temperature curve (a curve plotting a change in color density due to a temperature change changes the temperature from the low temperature side to the high temperature side and the high temperature side to the low temperature side). A carboxylic acid ester compound that exhibits a ΔT value (melting point-cloud point) of 5 ° C. or higher and lower than 50 ° C., which can form a reversible thermochromic composition that exhibits color memory, and changes color when changing to the side) For example, a carboxylic acid ester having a substituted aromatic ring in the molecule, an ester of a carboxylic acid having an unsubstituted aromatic ring and an aliphatic alcohol having 10 or more carbon atoms, a carboxylic acid ester having a cyclohexyl group in the molecule, 6 carbon atoms Fatty acid and unsubstituted aromatic alcohol or phenol ester, fatty acid having 8 or more carbon atoms and branched aliphatic alcohol or ester, dicarboxylic acid And esters of aromatic alcohols or branched aliphatic alcohols, dibenzyl cinnamate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, trilaurin, trimyristin, tristearin, Dimyristin, distearin and the like are used.

Also, fatty acid ester compounds obtained from an odd aliphatic monohydric alcohol having 9 or more carbon atoms and an aliphatic carboxylic acid having an even number of carbon atoms, n-pentyl alcohol or n-heptyl alcohol and an even fat having 10 to 16 carbon atoms. A fatty acid ester compound having a total carbon number of 17 to 23 obtained from a group carboxylic acid is also effective.
Specifically, n-pentadecyl acetate, n-tridecyl butyrate, n-pentadecyl butyrate, n-undecyl caproate, n-tridecyl caproate, n-pentadecyl caproate, n-nonyl caprylate, n-undecyl caprylate, N-tridecyl caprylate, n-pentadecyl caprylate, n-heptyl caprate, n-nonyl caprate, n-undecyl caprate, n-tridecyl caprate, n-pentadecyl caprate, n-pentyl laurate, lauric acid n-heptyl, n-nonyl laurate, n-undecyl laurate, n-tridecyl laurate, n-pentadecyl laurate, n-pentyl myristate, n-heptyl myristate, n-nonyl myristate, n-myristate Undecyl, n-tridecyl myristate, N-pentadecyl ristinate, n-pentyl palmitate, n-heptyl palmitate, n-nonyl palmitate, n-undecyl palmitate, n-tridecyl palmitate, n-pentadecyl palmitate, n-nonyl stearate, stearic acid n-undecyl, n-tridecyl stearate, n-pentadecyl stearate, n-nonyl eicosanoate, n-undecyl eicosanoate, n-tridecyl eicosanoate, n-pentadecyl eicosanoate, n-nonyl behenate, n-behenate Examples include undecyl, n-tridecyl behenate, and n-pentadecyl behenate.

As the ketones, aliphatic ketones having a total carbon number of 10 or more are effective, and 2-decanone, 3-decanone, 4-decanone, 2-undecanone, 3-undecanone, 4-undecanone, and 5-undecanone. 2-dodecanone, 3-dodecanone, 4-dodecanone, 5-dodecanone, 2-tridecanone, 3-tridecanone, 2-tetradecanone, 2-pentadecanone, 8-pentadecanone, 2-hexadecanone, 3-hexadecanone, 9-heptadecanone, 2 -Pentadecanone, 2-octadecanone, 2-nonadecanone, 10-nonadacanone, 2-eicosanone, 11-eicosanone, 2-heneicosanone, 2-docosanone, laurone, stearone and the like.
Further, arylalkyl ketones having 12 to 24 carbon atoms in total, such as n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-pentadecanophenone, n-tetradecano Phenone, 4-n-dodecanacetophenone, n-tridecanophenone, 4-n-undecanoacetophenone, n-laurophenone, 4-n-decanoacetophenone, n-undecanophenone, 4-n-nonylacetophenone, n -Decanophenone, 4-n-octylacetophenone, n-nonanophenone, 4-n-heptylacetophenone, n-octanophenone, 4-n-hexylacetophenone, 4-n-cyclohexylacetophenone, 4-tert-butylpropiophenone, n-heptaphenone, 4-n-pentylacetophene Emissions, cyclohexyl phenyl ketone, benzyl -n- butyl ketone, 4-n-butyl acetophenone, n- hexanophenone, 4-isobutyl acetophenone, 1-acetonaphthone, 2-acetonaphthone, cyclopentyl phenyl ketone.

As ethers, aliphatic ethers having a total carbon number of 10 or more are effective, and dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether, didecyl ether, diundecyl ether, didodecyl ether. , Ditridecyl ether, ditetradecyl ether, dipentadecyl ether, dihexadecyl ether, dioctadecyl ether, decane diol dimethyl ether, undecane diol dimethyl ether, dodecane diol dimethyl ether, tridecane diol dimethyl ether, decane diol diethyl ether, undecane diol diethyl ether Etc.
Further, the compound (c) is more preferably a compound represented by the formula (1) or (2), specifically a compound represented by the formula (1).

The compound shown by Formula (2) is shown concretely.
In the formula, R represents an alkyl group or alkenyl group having 8 or more carbon atoms, preferably an alkyl group having 10 to 24 carbon atoms, more preferably an alkyl group having 12 to 22 carbon atoms.
Examples of the compound include 1,1-diphenylmethyl octanoate, 1,1-diphenylmethyl nonanoate, 11-diphenylmethyl decanoate, 1,1-diphenylmethyl undecanoate, 1,1-genylmethyl dodecanoate, tridecanoic acid 1 1,1-diphenylmethyl, 1,1-diphenylmethyl tetradecanoate, 1,1-diphenylmethyl pentadecanoate, 1,1-diphenylmethyl hexadecanoate, 1,1-diphenylmethyl heptadecanoate, 1,1-diphenylyl octadecanoate, nonadecane Acid 1,1-diphenylmethyl, eicosanoic acid 1,1-diphenylmethylheneicosanoic acid 1,1-diphenylmethyl, docosanoic acid 1,1-diphenylmethyl, tocosanoic acid 1,1-diphenylmethyl, tetracosanoic acid 1,1 -Diphenylmethyl, 1,1-diphenylmethyl pentasanate 1,1-diphenylmethyl hexacosanoate, 1,1-diphenylmethyl heptaconate, 1,1-diphenylmethyl octacosanoate, 1,1-diphenylmethyl nonacosane, 1,1-diphenylmethyl triacontanoate, hentriakotanic acid An example is 1,1-diphenylmethyl.

Among the compounds represented by the formula (1), when R ₁ is a hydrogen atom, it is preferable because a reversible thermochromic composition having a wider hysteresis width can be obtained, and R ₁ is a hydrogen atom, and , M is more preferably 0.

Although the form of the microcapsule pigment applied to the present invention does not refuse application of a circular cross-sectional form, a non-circular cross-sectional form is effective.
The reversible thermochromic handwriting formed by writing has the above-mentioned microcapsule pigment closely oriented and fixed in close contact with the writing surface on the long diameter side (maximum outer diameter side). In addition, the microcapsule pigment is slightly elastically deformed into a shape that relaxes the external force against the external force caused by rubbing with a friction body such as rubber, and the destruction of the wall film of the microcapsule is suppressed. It can be expressed effectively without impairing the function.
Here, the non-circular cross-sectional shape microcapsule pigment has an average maximum outer diameter in the range of 0.5 to 5.0 μm and a reversible thermochromic composition / wall film = 7/1 to 1. / 1 (weight ratio) is preferably satisfied.
The microcapsule pigments (including those having a circular cross-sectional shape) exhibit a decrease in the ability to flow out from the capillary gap when the average maximum outer diameter exceeds 5.0 μm, while the average maximum outer diameter In a system having a value of 0.5 μm or less, it is difficult to show coloration at a high concentration. Preferably, the average value of the maximum outer diameter is in the range of 1 to 4 μm, and the average particle diameter of the microcapsule The minimum outer diameter) / 2] is preferably in the range of 1 to 3 μm.
If the ratio of the reversible thermochromic composition to the wall film is larger than the above range, the wall film becomes too thin, causing a decrease in pressure and heat resistance, and conversely, the reversible thermochromic composition of the wall film. When the ratio to the above is larger than the above range, the color density and sharpness during color development are unavoidable, and preferably the reversible thermochromic composition / wall film = 6/1 to 1/1 (weight ratio). .

  For the microencapsulation of the reversible thermochromic composition, known means such as an interfacial polymerization method, an interfacial polycondensation method, an in situ polymerization method, and a coacervate method can be applied, but the particle size range satisfying the above-described requirements of the present invention. In order to obtain a microcapsule pigment having a non-circular cross-sectional shape, it is effective to apply an interfacial polymerization method or an interfacial polycondensation method that hardly causes aggregation or coalescence.

  The microcapsule pigment can be blended in an amount of 2 to 50% by weight (preferably 3 to 40% by weight, more preferably 4 to 30% by weight) based on the total amount of the ink composition. If it is less than 2% by weight, the color density is insufficient, and if it exceeds 50% by weight, the ink outflow is reduced and the writing property is impaired.

The reversible thermochromic ink applied to the present invention is an ink in which a microcapsule pigment showing a colored state is dispersed in a vehicle, or an ink in which a microcapsule pigment showing a colorless state is dispersed in a vehicle is heated or cooled. It is effective to develop color.
The vehicle is preferably an aqueous vehicle, but may be an oil vehicle.
Specific examples include a shear-thinning ink containing a shear-thinning agent and an aggregating ink obtained by suspending a reversibly thermochromic microcapsule pigment in a gentle aggregation state with a water-soluble polymer flocculant. Furthermore, there is an ink in which the specific gravity difference between the reversible thermochromic pigment and the vehicle is adjusted to 0.05 or less.

By adding the shear thinning agent, it is possible to suppress the aggregation / sedimentation of the microcapsule pigment and to suppress the bleeding of the handwriting. Even if writing on the material, the handwriting does not bleed and a good handwriting can be formed.
Furthermore, when the writing instrument to be filled with the ink is in the form of a ballpoint pen, it prevents ink leakage from the gap between the ball and the tip when not in use, or the ink when the writing tip is left upward (upright state). Backflow can be prevented.
The viscosity of the ink added with the shear thinning agent is 20 to 300 mPa · s at a shear rate of 3.84S ⁻¹ measured by an E-type rotational viscometer at 20 ° C. It is preferable that the viscosity index is 0.1 to 0.9.
By showing the above-mentioned viscosity range and shear thinning index, it is possible to further leak ink and prevent ink backflow.
The shear thinning index (n) is expressed by an empirical formula T = Kj ⁿ (K is a non-Newtonian viscosity coefficient) obtained from rheological measurement by a viscometer such as a shear stress value (T) and a shear rate value (j). It is a value calculated by fitting.

  Examples of the shear thinning agent include xanthan gum, welan gum, succinoglycan (average molecular weight of about 1 to 8 million) whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose, guar gum, locust bean gum and derivatives thereof , Hydroxyethyl cellulose, alginic acid alkyl esters, polymers having a molecular weight of 100,000 to 150,000, mainly composed of alkyl esters of methacrylic acid, thickening agent having gelling ability extracted from seaweed such as glucomannan, agar and carrageenan Sugars, benzylidene sorbitol and benzylidene xylitol or their derivatives, crosslinkable acrylic acid polymer, inorganic fine particles, polyglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polio Shi polyoxyethylene alkyl ether-polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ether, nonionic HLB value, such as fatty acid amide is 8-12 surfactants, salts of dialkyl or dialkenyl sulfosuccinic acid. Examples thereof include a mixture of N-alkyl-2-pyrrolidone and an anionic surfactant, and a mixture of polyvinyl alcohol and an acrylic resin.

As the water-soluble polymer flocculant, a nonionic water-soluble polymer compound is preferably used.
Specific examples include polyvinyl pyrrolidone, polyethylene oxide, water-soluble polysaccharides, nonionic water-soluble cellulose derivatives, and the like. Among these, specific examples of water-soluble polysaccharides include tragacanth gum, guar gum, pullulan, cyclodextrin, and specific examples of nonionic water-soluble cellulose derivatives include methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxy Examples thereof include propylmethylcellulose.
In the reversible thermochromic ink of the present invention, any water-soluble polymer exhibiting a loose bridging action between pigment particles can be applied, but the nonionic water-soluble cellulose derivative is most effective. Works.
The polymer flocculant can be blended in an amount of 0.05 to 20% by weight based on the total amount of the ink composition.

  Examples of water-soluble organic solvents added together with water in the ink include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, and propylene glycol. , Butylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrole Don, N- methyl-2-pyrrolidone.

  Further, when the ink of the present invention is used by filling a ballpoint pen, a higher fatty acid such as oleic acid, a nonionic surfactant having a long chain alkyl group, a polyether-modified silicone oil, thiophosphorous acid tri (alkoxycarbonylmethyl ester) ) And thiophosphite triester (alkoxycarbonylethyl ester), etc., polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether phosphate monoester, polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether It is preferable to add a lubricant such as a phosphoric acid diester or a metal salt, an ammonium salt, an amine salt, an alkanolamine salt thereof to give the ball seat an antiwear effect.

In addition, resins such as acrylic resin, styrene maleic acid copolymer, cellulose derivative, polyvinyl pyrrolidone, polyvinyl alcohol, and dextrin can be added as necessary to impart adhesion to paper and viscosity.
In addition, pH adjusters such as inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, organic basic compounds such as water-soluble amine compounds, benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, saponin, etc. Rust preventive agent, coalic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- Preservatives or antifungal agents such as (methylsulfonyl) pyridine, urea, nonionic surfactants, reduced or non-reduced starch hydrolysates, oligosaccharides such as trehalose, sucrose, cyclodextrin, glucose, dextrin sorbit, mannitol The pillow Wetting agents such as phosphate sodium, defoamers, dispersing agents, a surfactant may be added a fluorine-based surfactant or a nonionic improve the ink permeability.

The ink is put into practical use by filling a marking pen or ballpoint pen with a marking pen tip or ballpoint pen tip attached to the writing tip.
When filling the ballpoint pen, the structure and shape of the ballpoint pen itself are not particularly limited. For example, the ballpoint pen has an ink containing tube filled with shear-thinning ink, and the ink containing tube contains a ball. An example is a ball-point pen that communicates with a tip attached to the tip, and further has a liquid stopper for backflow prevention in close contact with the end face of the ink.

The ballpoint pen tip will be described in more detail. A tip formed by holding a ball in a ball holding portion obtained by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, or a metal material is cut by a drill or the like A chip formed by holding the ball in the ball holding part formed by the above, a chip provided with a resin ball receiving seat inside a metal or plastic chip, or a ball held by the chip is moved forward by a spring body Energized items can be applied.
The ball is 0.3 to 3.0 mm, preferably 0.4 to 1.5 mm, more preferably 0.5 to 1.0 mm, such as cemented carbide, stainless steel, ruby, ceramic, resin, and rubber. A thing of a diameter is applicable.
In addition, the writing instrument filled with the ink of the present invention includes those provided with a rolling mechanism for forming a handwriting by the same rolling action as the ball.

For example, a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon is used as the ink storage tube for storing the ink.
Furthermore, by using a transparent, colored transparent, or translucent molded body as the ink containing tube, the ink color, the remaining amount of ink, and the like can be confirmed.
In addition to directly connecting the chip to the ink storage tube, the ink storage tube and the chip may be connected via a connecting member.
The ink storage tube may be a refill type in which the refill is stored in a shaft tube, or the shaft tube itself having a tip attached to a tip is used as an ink container, and ink is directly applied to the shaft tube. It may be filled.

An ink backflow preventer is filled at the rear end of the ink stored in the ink storage tube.
The ink backflow prevention body composition is composed of a non-volatile liquid or a hardly volatile liquid.
Specifically, petroleum jelly, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or co-oligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, Examples thereof include polyether-modified silicone oil and fatty acid-modified silicone oil, and one or more can be used in combination.

It is preferable to add a gelling agent to the nonvolatile liquid and / or the hardly volatile liquid to increase the viscosity to a suitable viscosity. The surface of the silica is hydrophobized, the surface is methylated fine particle silica, and aluminum silicate. , Swellable mica, hydrophobic thickeners such as bentonite and montmorillonite, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, tribenzylidene sorbitol, fatty acid amide, amide modified Examples include dextrin compounds such as polyethylene wax, hydrogenated castor oil, fatty acid dextrin, and cellulose compounds.
Furthermore, the liquid ink backflow prevention body composition and a solid ink backflow prevention body composition can be used in combination.

  In addition, when filling a marking pen, the structure and shape of the marking pen itself are not particularly limited. For example, a fiber in which an ink occlusion body made of a fiber converging body is built in a shaft cylinder and a capillary gap is formed. Marking in which a pen body made of a processed body is mounted on a shaft cylinder directly or via a relay member, and the ink storage body of the marking pen formed by connecting the ink storage body and the pen body is impregnated with cohesive ink A pen can be exemplified.

The pen body is a porous member having continuous ventilation holes selected from the range of generally 30 to 70% of general porosity, such as a resin processed body of fibers, a fusion processed body of hot melt fibers, and a felt body. One end is processed into a shape corresponding to the purpose such as a bullet shape, a rectangular shape, a chisel shape, etc.
The chisel-shaped pen body has versatility that can form marks with a constant line width for fine writing or for thick writing by changing the contact position on the writing surface. It is possible to construct a writing instrument that is excellent in convenience and capable of forming a handwriting with a good thermochromic property.
The ink occlusion body is formed by converging crimped fibers in the longitudinal direction, and is made to be contained in a covering body such as a plastic cylinder or a film and adjusted to have a porosity of approximately 40 to 90%. The
Further, the form of the ballpoint pen or the marking pen is not limited to that described above, and it may be a twin-type writing instrument with a pen body with a different form or a pen body with which a different color tone is derived. Good.

The handwriting obtained by writing on a writing material such as paper with the above-described writing tool can change the color tone from a colored state to a colorless state by rubbing with a finger, heating, or applying a cooling tool.
Examples of the heating means include a heating color changer equipped with a resistance heating element, a heating color changer filled with warm water, and a hair dryer. Preferably, a scraping member is used as a means capable of changing color by a simple method. Used.
As the rubbing member, an elastic body such as an elastomer or a plastic foam which is rich in elasticity and can generate frictional heat by rubbing at the time of rubbing is preferable, but a plastic molded body, stone material, wood, Metals and fabrics may be used.
Although it is possible to scrape the handwriting by using an eraser, it is preferable to use a rubbing member as described above because erase scraps are generated at the time of rubbing.
As the material of the rubbing member, silicone resin or SEBS resin (styrene ethylene butadiene styrene block copolymer) is preferably used. However, the silicone resin easily adheres to the portion erased by rubbing, and when repeatedly written. Since the handwriting tends to be repelled, SEBS resin is more preferably used.
The scraping member may be a member having an arbitrary shape that is separate from the writing instrument, but is excellent in portability by being fixed to the writing instrument.
Examples of the location where the rubbing member is fixed include a cap tip (top) or a shaft tube tip (portion where no writing tip is provided).
Furthermore, it is also possible to provide a small protrusion of any shape on a part of the cap or a part of the shaft tube to make a scraping member.
Examples of the cooling means include a cold / hot color changing tool using a Peltier element, a cold / hot color changing tool filled with a coolant such as cold water and ice pieces, a refrigerator and a freezer.

The colored transparent sheet is a sheet-like product formed by containing a colorant in a transparent resin, or a sheet-like product formed with a transparent resin, and its size and thickness are particularly limited. However, there are those having a size and thickness of an underlay, rulers, and those having a size and thickness of a strip.
The colored transparent sheet satisfies the color relationship of the same color (including similar colors) as the colored hue exhibited by the reversible thermochromic ink.
This will be described in detail. When the color is red, the colored transparent sheet is a similar red sheet. Moreover, when exhibiting green, a colored transparent sheet is also the same green sheet. In the case described above, when the color tone of the colored transparent sheet is dark with respect to the color tone of the handwriting, the handwriting is not easily visualized when the sheet is placed on the handwriting.
In addition, even if the colored hue exhibited by the reversible thermochromic ink does not exhibit the same color as the hue of the colored transparent sheet, the colored hue exhibited by the reversible thermochromic ink is a subtractive color mixture of the hue of the colored transparent sheet. The same effect can be obtained by using the constituent colors.
Specifically, the combination of the color of the handwriting and the color of the sheet that makes the handwriting invisible is as follows: yellow handwriting and orange, red, green sheet, orange handwriting and red sheet, pink A combination of colored handwriting and red and purple sheets, and blue handwriting and purple and green sheets.

A specific method of using the reversible thermochromic writing instrument set comprising the writing instrument of the present invention and a colored transparent sheet will be described. A writing instrument containing reversible thermochromic ink that changes color from red to colorless, and a red transparent sheet. In the case of a writing instrument set, the red handwriting obtained by writing a desired character string on paper with the writing instrument is red in a normal state, and when a red transparent sheet is placed on the handwriting, the red handwriting is It is no longer visible.
When the handwriting is abraded with a friction body, the rubbing portion of the handwriting discolors to be colorless and is not visually recognized.
Therefore, since it becomes invisible when a colored transparent sheet is placed at a place to be stored in an arbitrary character string written by the user, it is effective for memorization and the handwriting can be erased after memorization.

  The above-described configuration is suitable for memorization. For example, in the case of a writing instrument containing a reversible thermochromic ink that changes color from orange to colorless and a writing instrument set made of a red transparent sheet, the writing instrument is desired on the paper surface. The orange handwriting obtained by writing the character string is orange in a normal state, and when the red transparent sheet is placed on the handwriting, the handwriting part is not visually recognized. Further, when the handwriting is abraded with a friction body, the handwritten part of the abraded portion is discolored in a colorless manner and is not visually recognized.

Examples are shown below, but the present invention is not limited to these examples.
In addition, the part in an Example is a weight part.
Example 1 (see FIGS. 3 to 5)
Preparation of reversible thermochromic ink (i) 1.0 part of 1,2-benz-6- (N-ethyl-N-isoamylamino) fluorane as component, 1,3-dimethyl-6-diethylaminofluorane 2.0 Part (b), 1,1-bis (4′-hydroxyphenyl) 2-ethylhexane 8.0 parts, (c) color memory comprising 40.0 parts palmitic acid-4-methylbenzyl as component (c) A microcapsule pigment (T ₁ : −2 ° C., T ₂ : 10 ° C., T ₃ : 35 ° C., T ₄ : 48 ° C., average particle size: 2.5 μm, reversible thermochromic) Composition / wall membrane = 2.6 / 1.0, color change from red to colorless) 12.5 parts, succinoglycan (shear thinning agent) 0.33 parts, urea 10 parts, glycerin 10 parts , 0.6 part of a nonionic permeability imparting agent, Sex silicone anti-foaming agent 0.1 parts, 0.1 parts of a fungicide, to prepare a reversible thermochromic ink comprising water 66.37 parts.

Preparation of writing instrument The ink (previously cooled to −2 ° C. or less to cause the microcapsule pigment to develop a red color and left at room temperature) is sucked and filled into a polypropylene pipe having an inner diameter of 4.4 mm, and a resin holder And connected to a ballpoint pen tip.
Next, a viscoelastic ink backflow prevention body (liquid stopper) mainly composed of polybutene is filled from the rear part of the polypropylene pipe, and a tail plug is fitted to the rear part of the pipe. After the cylinder was assembled and the cap was fitted, a degassing process was performed by centrifugation to obtain a reversible thermochromic ballpoint pen.
The ball-point pen tip has a stainless steel ball having a diameter of 0.7 mm held at the tip end of a tip formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, and the ball is a spring. The cap is urged forward by the body, and the cap is provided with a SEBS resin member as a rubbing member at the top.

Preparation of colored transparent sheet A red transparent sheet (130 mm × 30 mm, thickness 0.5 mm) in which the transparent resin was colored red was obtained.

Preparation of thermochromic writing instrument set A thermochromic writing instrument set was obtained by combining the reversible thermochromic ballpoint pen and a red transparent sheet.
Using the ballpoint pen, a red “apple” character (handwriting 2) was formed by writing on the paper surface 1 (see FIG. 3) on which the black “apple” character (printed image 2) had been previously formed (see FIG. 3). 4).
The handwriting 2 is red at room temperature (25 ° C.). When the red transparent sheet 3 is placed on the letter, the printed image 2 is visible, but the letter “apple” has the same color as the sheet. Therefore, it was no longer visible (see FIG. 5).
When rubbing with a scraping member from above the characters “apple”, the characters disappeared and were not visually recognized, and this state could be maintained at room temperature (see FIG. 3).
Again, using the writing instrument, it was possible to form a character at the location where the character “apple” was formed, and a thermochromic writing instrument set excellent in convenience was obtained.

Example 2
Preparation of reversible thermochromic ink (a) 2- (Butylamino) -8- (diphenylamino) -4-methylspiro [5H- [1] benzopyrano [2-3-g] pyrimidine-5,1 (3) 'H) -Isobenzofuran] -3-one 2.0 parts by weight, (2-) 2,2-bis (4'-hydroxyphenyl) hexafluoropropane 5.0 parts by weight, 1,1-bis (4 '-Hydroxyphenyl) n-decane 3.0 parts by weight, and (c) microcapsules encapsulating a reversible thermochromic composition having color memory consisting of 4-benzyloxyphenylethyl caprate as component 5) Pigment (T ₁ : −16 ° C., T ₂ : −8 ° C., T ₃ : 48 ° C., T ₄ : 58 ° C., ΔH: 65 ° C., average particle size: 2.5 μm, reversible thermochromic composition / wall film = 2.6 / 1.0, pin A uniform color in an aqueous medium consisting of 12 parts, 5 parts of glycerin, 0.7 parts of antifungal agent, 0.1 part of silicone antifoaming agent and 74.2 parts of water. After that, hydroxyethylcellulose (Union Carbide Japan Co., Ltd., trade name: Cellosize WP-09L, water-soluble polymer flocculant) was added to the liquid in a dispersed state while stirring 8 parts of a 5% by weight aqueous solution. Then, a reversible thermochromic ink was prepared by suspending the reversible thermochromic pigment in a loosely aggregated state.

Preparation of writing instrument The reversibly thermochromic ink (preliminarily cooled to -16 ° C. or lower to develop a microcapsule pigment in a fiber-focused ink occlusion body (porosity of about 80%) covered with a polyester resin sliver. A polyester fiber resin processing pen body (porosity of about 50%) that is impregnated immediately after being uniformly stirred and accommodated in the shaft cylinder and attached to the tip of the shaft cylinder. It assembled in the contact state and obtained the reversible thermochromic marking pen.
The shaft tube is provided with a SEBS resin member as a rubbing member at the rear.

Preparation of colored transparent sheet A red transparent sheet (260 mm × 180 mm, thickness 1 mm) obtained by coloring a transparent resin in red was obtained.

Preparation of thermochromic writing instrument set A thermochromic writing instrument set was obtained by combining the reversible thermochromic marking pen and a red transparent sheet.
Using the marking pen, a pink “DOG” character (handwriting 2) was formed by writing on a paper surface on which a brown dog pattern was previously formed.
The handwriting has a pink color at room temperature (25 ° C.). When a red transparent sheet is placed on the letter, the pattern is visible, but the letter “DOG” is a component color by subtractive color mixing of the sheet. Disappeared because of it.
When rubbing with a scraping member on the character “DOG”, the character disappeared and was not visually recognized, and this state could be maintained at room temperature.
Again, a [dog] character could be formed at the location where the character “DOG” was formed using the writing instrument, and a thermochromic writing instrument set excellent in convenience was obtained.

Example 3
Preparation of reversible thermochromic ink (i) 2,5-part by weight of 1,3-dimethyl-6-diethylaminofluorane as component, 2,2-bis (4'-hydroxyphenyl) hexafluoropropane 5 as component (b) A color memory comprising 0.0 parts by weight, 4.0 parts by weight of 1,1-bis (4′-hydroxyphenyl) n-decane, and 50.0 parts by weight of 4-benzyloxyphenylethyl laurate as component (c). A microcapsule pigment (T ₁ : −8 ° C., T ₂ : −1 ° C., T ₃ : 52 ° C., T ₄ : 65 ° C., ΔH: 63 ° C., average particle size: 2) 0.5 μm, reversible thermochromic composition / wall film = 2.6 / 1.0, color change from orange to colorless) 12.5 parts, succinoglycan (shear thinning agent) 0.33 parts, urea 10 parts, glycerin 10 parts, nonio A reversible thermochromic ink comprising 0.6 part of a penetrability agent, 0.1 part of a modified silicone antifoaming agent, 0.1 part of an antifungal agent and 66.37 parts of water was prepared.

Preparation of writing instrument The above ink (previously cooled to −8 ° C. or less to cause the microcapsule pigment to develop an orange color and then allowed to stand at room temperature) is sucked and filled into a polypropylene pipe having an inner diameter of 4.4 mm, and a resin holder And connected to a ballpoint pen tip.
Next, a viscoelastic ink backflow prevention body (liquid stopper) mainly composed of polybutene is filled from the rear part of the polypropylene pipe, and a tail plug is fitted to the rear part of the pipe. After the cylinder was assembled and the cap was fitted, a degassing process was performed by centrifugation to obtain a reversible thermochromic ballpoint pen.
The ball-point pen tip has a stainless steel ball having a diameter of 0.5 mm held at the tip of a tip formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, and the ball is a spring The body is urged forward by the body, and the rear barrel is formed by attaching SEBS resin as a friction member to the rear part.

Production of colored transparent sheet A red transparent sheet (150 mm × 50 mm, thickness 0.3 mm) in which the transparent resin was colored red was obtained.

Preparation of thermochromic writing instrument set A thermochromic writing instrument set was obtained by combining the reversible thermochromic ballpoint pen and a red transparent sheet.
Using the ballpoint pen, an orange “apple” character (handwriting) was formed by writing on a paper surface on which black “APPLE” characters had been previously formed.
The handwriting has an orange color at room temperature (25 ° C.). When a red transparent sheet is placed on the letter, the letter “APPLE” is visible, but the letter “apple” is a subtractive color mixture of the sheet. Due to the composition color, it is no longer visible.
When the “apple” character was rubbed with a scraping member, the character disappeared and was not visually recognized, and this state could be maintained at room temperature.
Again, "apple" characters could be formed at the locations where the "apple" characters were formed using the writing instrument, and a thermochromic writing instrument set excellent in convenience was obtained.

Example 4
Preparation of reversible thermochromic ink (a) 4,5,6,7-tetrachloro-3,3-bis [4- (diethylamino) -2-ethoxyphenyl] -1 (3H) isobenzofuranone as component (1) 5 parts, 5.0 parts of 2,2-bis (4′-hydroxyphenyl) hexafluoropropane, 3.0 parts of 1,1-bis (4′-hydroxyphenyl) n-decane, ) Microcapsule pigment (T ₁ : −18 ° C., T ₂ : −9 ° C.) encapsulating a reversible thermochromic composition having color memory consisting of 50.0 parts of capric acid-4-benzyloxyphenylethyl (T ₃ : 42 ° C., T ₄ : 63 ° C., average particle size: 2.5 μm, reversible thermochromic composition / wall film = 2.6 / 1.0, color change from green to colorless) 12.5 parts , Xanthan gum (shear thinning agent) 0.3 3 parts, 10 parts urea, 10 parts glycerin, 0.6 part nonionic permeability imparting agent, 0.1 part modified silicone antifoaming agent, 0.1 part antifungal agent, 66.37 parts water A color changing ink was prepared.

Preparation of writing instrument 0.97 g of the ink (previously cooled to −18 ° C. or lower and allowed to stand at room temperature after coloring the microcapsule pigment in green) was sucked and filled in 0.97 g of polypropylene pipe having an inner diameter of 4.4 mm, It connected with the ball-point pen tip through the resin holder.
Next, a viscoelastic ink backflow prevention body (liquid stopper) mainly composed of polybutene is filled from the rear part of the polypropylene pipe, and a tail plug is fitted to the rear part of the pipe. After the cylinder was assembled and the cap was fitted, a degassing process was performed by centrifugation to obtain a reversible thermochromic ballpoint pen.
The ball-point pen tip has a stainless steel ball having a diameter of 0.5 mm held at the tip of a tip formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, and the ball is a spring The body is urged forward by the body, and a silicone rubber is fixed to the rear barrel as a friction member at the rear.

Preparation of colored transparent sheet A green transparent sheet (200 mm × 100 mm, thickness 1.5 mm) in which the transparent resin was colored green was obtained.

Preparation of thermochromic writing instrument set A thermochromic writing instrument set was obtained by combining the reversible thermochromic ballpoint pen and a green transparent sheet.
Using the ball-point pen, a green “H ₂ O” character (handwriting) was formed by writing on a paper surface in which a black “water” character was previously formed.
The handwriting is green at room temperature (25 ° C.). When a green transparent sheet is placed on the letter, the letter “water” is visible, but the letter “H ₂ O” is the sheet. It disappeared because of the same color.
When rubbing with a scraping member from above the characters “H ₂ O”, the characters disappeared and were not visually recognized, and this state could be maintained at room temperature.
Again, using the writing instrument, the same character could be formed at the location where the letter “H ₂ O” was formed, and a thermochromic writing instrument set excellent in convenience was obtained.

It is a graph explaining the hysteresis characteristic in the color density-temperature curve of the reversible thermochromic composition which has color memory property used for this invention. It is a graph explaining the hysteresis characteristic in the color density-temperature curve of the reversible thermochromic composition which has color memory property used for this invention. It is explanatory drawing which shows the paper surface to which this invention thermochromic writing instrument set is applied. It is explanatory drawing which shows the state which formed the handwriting on the paper surface using the writing instrument of this invention thermochromic writing instrument set. It is explanatory drawing which shows the state which mounted the colored transparency sheet | seat on the handwriting formed on the paper surface of FIG.

Explanation of symbols

T ₁ complete color development temperature T ₂ color development start temperature T ₃ color erasure start temperature T ₄ complete color erasure temperature ΔH hysteresis width 1 paper surface 2 printed image 3 handwriting 4 colored transparency sheet

Claims (6)

  (A) Reversible thermochromic property comprising at least an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling the color reaction of (a) and (b). A writing instrument containing a reversible thermochromic ink in which a microcapsule pigment that changes color from colorless to colorless according to a temperature change encapsulating the composition is dispersed in a vehicle, and the microcapsule pigment is in a colored state, and a colored transparent sheet The colored hue exhibited by the reversible thermochromic ink and the hue of the colored transparent sheet are the same color, or the colored hue exhibited by the reversible thermochromic ink is due to subtractive color mixing of the hue of the colored transparent sheet. A thermochromic writing instrument set characterized by being included as a constituent color. The microcapsule pigment is a pigment that exhibits a large hysteresis characteristic with respect to a color density-temperature curve, exhibits tautomerism between the first hue and the second hue, and has a two-phase holding temperature range in which both phases can coexist in a normal temperature range. the pigment is in the process of temperature in the first color state is increased and reaches the second temperature T _3, the first color begins to discolor, the second high temperature T ₄ or more than the temperature T ₃ In the process of completely becoming the second hue in the region and in the second hue state and the temperature decreasing, when the first temperature T ₂ lower than the second temperature T ₃ is reached, the second hue starts to change color, The first hue is completely obtained in a temperature range lower than the first temperature T ₂ and lower than the temperature T ₁ , and the first hue and the second hue are obtained in a temperature range between the first temperature T ₂ and the second temperature T _3. Shows a hysteresis characteristic in which both phases can coexist, and temperature T ₁ is −30 to 0 ° C. In the range of thermochromic writing instrument set according to claim 1, wherein the temperature T ₄ is in the range of 40 to 80 ° C.. The thermochromic writing instrument set according to claim 1 or 2, wherein the reaction medium for controlling the color reaction of (a) and (b) is a compound represented by the following formula (1) or (2).

[Wherein, R ₁ represents a hydrogen atom or a methyl group, m represents an integer of 0 to 2, and _one of X ₁ and X ₂ represents — (CH ₂ ) _n OCOR ₂ or — (CH ₂ ) _n COOR ₂ , the other represents a hydrogen atom, n represents an integer of 0 to 2, R ₂ represents an alkyl or alkenyl group having 4 or more carbon atoms, Y ₁ and Y ₂ represent a hydrogen atom, 1 to 4 carbon atoms An alkyl group, a methoxy group, or halogen, and r and p each represent an integer of 1 to 3. ]

[Wherein, R represents an alkyl group or an alkenyl group having 8 or more carbon atoms. ]   The thermochromic writing instrument set according to any one of claims 1 to 3, comprising a friction body.   The thermochromic writing instrument set according to claim 4, wherein a friction body is attached to the writing instrument.   The thermochromic writing instrument set according to claim 4 or 5, wherein the friction body is rubber or plastic foam.

Images