JP2012077260A - Pastel tone reversibly thermochromic ink composition for writing utensil, and writing utensil and writing utensil set using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pastel tone reversibly thermochromic ink composition for writing utensils, in which handwriting formed by writing on a colored writing surface has a pastel tone color, and which shows such good erasability of handwriting that a clouded residual image is not visible in the handwriting part when handwriting is decolored, and to provide writing utensils and a writing utensil set using the ink composition.SOLUTION: The pastel tone reversibly thermochromic ink composition for writing utensils contains: a microcapsule pigment that changes from chromatic color to achromatic color and has an average particle size of 0.01-1.0 μm; and a microcapsule pigment that changes from white color to achromatic color and has an average particle size of 0.01-1.0 μm; wherein a weight ratio between the microcapsule pigment that changes from chromatic color to achromatic color and the microcapsule pigment that changes from white color to achromatic color is 1:1 to 1:25. Then, the writing utensils 1 and the writing utensil set using the ink composition are provided.

Description

  The present invention relates to an ink composition for a pastel reversible thermochromic writing instrument, a writing instrument using the same, and a writing instrument set.

Conventionally, there has been disclosed a reversible thermochromic writing instrument ink capable of forming a handwriting whose color tone changes with temperature change, and a writing instrument containing the ink (see, for example, Patent Document 1).
The handwriting formed by the writing instrument can change the reversible thermochromic material in the handwriting from colored to colorless with a body temperature such as touch, frictional heat generated by rubbing, a hair dryer, etc., and as a result, the handwriting can be erased. However, a cloudy afterimage (handwriting) is visually recognized at the location where the handwriting is erased.
The white turbid afterimage is difficult to see when the writing surface (paper) is white, but when written on a colored writing surface, the afterimage is remarkably visually recognized, which impairs practicality.

JP-A-7-186588

  The present invention is intended to solve the above-described problems, that is, to form handwriting having a pastel color when writing on a colored writing surface as well as a white writing surface. Thus, an object of the present invention is to provide an ink composition for a pastel tone reversible thermochromic writing instrument and a writing instrument containing the same, in which when the handwriting is erased, a cloudy afterimage is not visually recognized in the handwriting part.

The present invention relates to a reversible thermochromic composition comprising water and (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color reaction occurs. A microcapsule pigment having an average particle diameter of 0.01 to 1.0 μm which changes from colored to colorless in which the product is encapsulated, and crystalline esters having a melting point in the range of −40 ° C. to + 95 ° C., ethers, A microcapsule pigment having an average particle diameter of 0.01 to 1.0 μm which changes from white to colorless and encapsulating a compound selected from ketones, and which changes from colored to colorless; A pastel tone reversible thermochromic ink composition having a weight ratio of a microcapsule pigment that changes from white to colorless is 1: 1 to 1:25.
Further, the microcapsule pigment that changes from colored to colorless has a particle size of 1.5 μm or more of 30% by volume or less in the total microcapsule pigment, and the microcapsule pigment that changes from white to colorless has a color of 1.5 μm. The above particles are 30% by volume or less in the total microcapsule pigment, the average particle diameter of the microcapsule pigment that changes from colored to colorless is in the range of 0.1 to 0.65 μm, and white to colorless. The average particle size of the microcapsule pigment that changes color to 0.1 to 0.65 μm, comprising a polymer flocculant, a comb polymer dispersant having a carboxyl group in the side chain, and organic A nitrogen-sulfur compound, a water-soluble resin, a water-soluble organic solvent, a comb-type polymer dispersant having a carboxyl group in the side chain, an organic nitrogen-sulfur compound, water The organic nitrogen sulfur compound is 2- (4-thiazoyl) -benzimidazole, 2- (thiocyanatomethylthio) -1,3-benzothiazole, 2-methyl-4-isothiazoline-3 It is a requirement that it is a compound selected from -one and 5-chloro-2-methyl-4-isothiazolin-3-one, and that it contains a shear thinning agent.
Furthermore, a writing instrument set including a writing instrument, a writing instrument, and a friction body containing the ink composition for a pastel reversible thermochromic writing instrument is required.

  In the present invention, the handwriting formed by writing on the colored writing surface has a pastel color, and when the handwriting is decolored, a white cloudy afterimage is not visually recognized in the handwriting part, and is good. An ink composition for a pastel tone reversible thermochromic writing instrument that exhibits the erasability of handwriting and a writing instrument containing the ink composition can be provided.

It is explanatory drawing which shows the discoloration behavior of the microcapsule pigment which included the heat decoloring type reversible thermochromic composition. It is explanatory drawing which shows the discoloration behavior of the microcapsule pigment which included the heat decoloring type reversible thermochromic composition which has color memory property. It is explanatory drawing which shows the discoloration behavior of the microcapsule pigment which included the heating coloring type reversible thermochromic composition. It is explanatory drawing which shows one Example of the writing instrument of this invention. It is explanatory drawing which shows the other Example of the writing instrument of this invention. It is explanatory drawing which shows the other Example of the writing instrument of this invention. It is explanatory drawing which shows the other Example of the writing instrument of this invention. It is explanatory drawing which shows the other Example of the writing instrument of this invention. It is explanatory drawing which shows the other Example of the writing instrument of this invention. It is explanatory drawing which shows the other Example of the writing instrument of this invention. It is explanatory drawing which shows the other Example of the writing instrument of this invention.

The colorant contained in the ink composition for a pastel reversible thermochromic writing instrument includes (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a color reaction of the both. It is a reversible thermochromic microcapsule pigment that changes color from colored (excluding white) encapsulating a reversible thermochromic composition comprising a reaction medium that determines the occurrence temperature.
Examples of the reversible thermochromic composition include those described in Japanese Patent Publication No. 51-44706, Japanese Patent Publication No. 51-44707, Japanese Patent Publication No. 1-29398, etc., at a predetermined temperature (discoloration point). Discolored before and after, decolored state in the temperature range above the high temperature side discoloration point, color development state in the temperature range below the low temperature side discoloration point, only one specific state exists in the normal temperature range among the two states, The other state is maintained as long as the heat or cold required to develop the state is applied, but when the heat or cold is no longer applied, the hysteresis width returns to the state exhibited in the normal temperature range. A heat decoloring reversible thermochromic composition having relatively small characteristics (ΔH = 1 to 7 ° C.) can be applied (see FIG. 1).

In addition, large hysteresis characteristics (ΔH _B = 8 to 50 ° C.) described in JP- _B -4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, and the like. ), That is, when the shape of the curve plotting the change in the color density due to the temperature change is lowering the temperature from the lower temperature side than the color changing temperature range, as opposed to increasing the temperature from the lower temperature side. In the specific temperature range, the color changes in a low temperature range below the complete color development temperature (t ₁ ) or the color erase state in the high temperature range above the complete color erase temperature (t ₄ ). A heat decoloring reversible thermochromic composition having color memory in the [temperature range between t _{2 and} t ₃ (substantially two-phase holding temperature range)] can also be applied (see FIG. 2).

The hysteresis characteristic in the color density-temperature curve of the reversible thermochromic composition will be described.
In FIG. 2, 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 a density at a temperature t ₄ (hereinafter referred to as a complete decoloring temperature) that reaches a completely decolored state, and B is a temperature t ₃ (hereinafter referred to as a decoloring start temperature). C is a point indicating a density at a temperature t ₂ at which color development starts (hereinafter referred to as a color development start temperature), and D is a temperature t ₁ at which a complete color development state is reached (hereinafter referred to as a complete color development state). This is a point indicating a density at a color development temperature).
Discoloration temperature region is a temperature range between the t ₁ and t _4, it is possible to exhibit any of the states of the colored state and the decolored state, between t ₂ and t ₃ is a region having a large difference in color density The temperature range is substantially the discoloration 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.

Specifically, as the reversible thermochromic composition having color memory, a complete color development temperature t ₁ can be obtained only in a freezing room, a cold district, etc., that is, −50 to 0 ° C., preferably −40 to − 5 ° C., more preferably −30 to −10 ° C., and the temperature at which the complete decoloring temperature t ₄ is obtained from a frictional heat generated by a friction body, a heating body such as a hair dryer, that is, 45 to 95 ° C., preferably 50 to 90
By specifying the temperature in the range of 60 ° C., more preferably in the range of 60 to 80 ° C., and specifying the ΔH value in the range of 40 to 100 ° C., it is possible to effectively function to maintain the color exhibited in the normal state (daily life temperature range).
If the complete color erasing temperature t ₄ is 45 ° C. or higher, the state before discoloration can be maintained even under high temperature conditions such as summer, and if it is 95 ° C. or lower, the handwriting formed on the writing surface Can be sufficiently erased by frictional heat due to several rubbing by the friction member.
Complete decoloring If the temperature t ₄ is a temperature exceeding 95 ° C., since the frictional heat obtained by rubbing due to friction member is less likely to reach the complete decoloring temperature, easily becomes difficult to erase, or increased abrasion number, or Since the load tends to be excessively rubbed, the writing surface may be damaged.
Further, in the temperature setting of the complete coloring temperature t _1, is preferably a lower temperature to be maintained in the decolored state is normal use, is preferably 0 ℃ less.
Furthermore, it is necessary to make the reversible thermochromic composition filled in the writing instrument into a colored state. Therefore, it is necessary to cool the writing instrument, the ink composition, or the microcapsule pigment in advance to develop the reversible thermochromic composition.
As a cooling means in the production process, it is preferable to cool with a general-purpose freezer, but considering the cooling capacity of the freezer, the limit is up to −50 ° C.

Examples of the compounds (a), (b), and (c) of the reversible thermochromic composition are shown below.
Examples of the electron donating color-forming organic compound as component (a) of the present invention include diphenylmethane phthalides, phenyl indolyl phthalides, indolyl phthalides, diphenyl methane azaphthalides, and phenyl indolyl azaphthalides. , Fluorans, stylinoquinolines, diazarhodamine lactones and the like.
Examples of these compounds are given 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-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-chloroamino) -6-dibutylaminofluorane,
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-diethylaminofluorane,
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-g) pyrimidine-5,1 ′ (3′H) isobenzofuran] -3-one,
2- (Di-n-butylamino) -8- (di-n-butylamino) -4-methyl-spiro [5H- (1) benzopyrano (2,3-g) pyrimidine-5,1 '(3' H) Isobenzofuran] -3-one,
2- (Di-n-butylamino) -8- (diethylamino) -4-methyl-spiro [5H- (1) benzopyrano (2,3-g) 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-g) pyrimidine-5,1 ' (3′H) isobenzofuran] -3-one,
2- (Dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- (1) benzopyrano (2,3-g) pyrimidine-5,1 '(3'H) -isobenzofuran] -3 -On,
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-methylindol-3-yl) -4,5,6,7-tetrachlorophthalide,
4,5,6,7-Tetrachloro-3- [4- (dimethylamino) -2-methylphenyl] -3- (1-ethyl-2-methyl-1H-indol-3-yl) -1 (3H ) -Isobenzofuranone,
3 ′, 6′-bis [phenyl (2-methylphenyl) amino] -spiro [isobenzofuran-1 (3H), 9 ′-[9H] xanthen] -3-one,
3 ′, 6′-bis [phenyl (3-methylphenyl) amino] -spiro [isobenzofuran-1 (3H), 9 ′-[9H] xanthen] -3-one,
And 3 ', 6'-bis [phenyl (3-ethylphenyl) amino] -spiro [isobenzofuran-1 (3H), 9'-[9H] xanthen] -3-one.
Furthermore, there can be mentioned pyridine-based, quinazoline-based, bisquinazoline-based compounds and the like which are effective for developing a fluorescent yellow to red color, such as 4- [2,6-bis (2-ethoxyphenyl). -4-pyridinyl] -N, N-dimethylbenzenamine.

As the electron-accepting compound of the component (b), a compound group having active protons, a pseudo-acidic compound group (a compound group that is not an acid but acts as an acid in the composition to cause the component (I) to develop color), There is a group of compounds having electron vacancies.
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. Alternatively, those having an amide group, a halogen group, etc., and bis-type and tris-type phenols, phenol-aldehyde condensation resins and the like can be mentioned. Moreover, the metal salt of the compound which has the said phenolic hydroxyl group may be sufficient.

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, 1,1-bis (4-hydroxyphenyl) 2-ethylhexane, 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, there is 2,2-bis (4-hydroxyphenyl) n- nonane.
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, and ethers.
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-nonadecanone, 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, may be mentioned 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, decanediol dimethyl ether, undecane diol dimethyl ether, dodecane diol dimethyl ether, tridecane diol dimethyl ether, decane diol diethyl ether, undecane diol diethyl ether Etc.

〔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。〕
前記式（１）で示される化合物のうち、Ｒ_１が水素原子の場合、より広いヒステリシス幅を有する可逆熱変色性組成物が得られるため好適であり、更にＲ_１が水素原子であり、且つ、ｍが０の場合がより好適である。
なお、式（１）で示される化合物のうち、より好ましくは下記一般式（２）で示される化合物が用いられる。

式中の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が、好ましくは炭素数１０〜２４のアルキル基、更に好ましくは炭素数１２〜２２のアルキル基である。
前記化合物として具体的には、オクタン酸−４−ベンジルオキシフェニルエチル、ノナン酸−４−ベンジルオキシフェニルエチル、デカン酸−４−ベンジルオキシフェニルエチル、ウンデカン酸−４−ベンジルオキシフェニルエチル、ドデカン酸−４−ベンジルオキシフェニルエチル、トリデカン酸−４−ベンジルオキシフェニルエチル、テトラデカン酸−４−ベンジルオキシフェニルエチル、ペンタデカン酸−４−ベンジルオキシフェニルエチル、ヘキサデカン酸−４−ベンジルオキシフェニルエチル、ヘプタデカン酸−４−ベンジルオキシフェニルエチル、オクタデカン酸−４−ベンジルオキシフェニルエチルを例示できる。 Furthermore, a compound represented by the following general formula (1) is preferably used as the component (c).

[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. ]
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.
Of the compounds represented by the formula (1), a compound represented by the following general formula (2) is more preferably used.

R in the formula 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.
Specific examples of the compound include octanoic acid-4-benzyloxyphenylethyl, nonanoic acid-4-benzyloxyphenylethyl, decanoic acid-4-benzyloxyphenylethyl, undecanoic acid-4-benzyloxyphenylethyl, and dodecanoic acid. -4-benzyloxyphenylethyl, tridecanoic acid-4-benzyloxyphenylethyl, tetradecanoic acid-4-benzyloxyphenylethyl, pentadecanoic acid-4-benzyloxyphenylethyl, hexadecanoic acid-4-benzyloxyphenylethyl, heptadecanoic acid Examples thereof include -4-benzyloxyphenylethyl and octadecanoic acid-4-benzyloxyphenylethyl.

（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し、ｍ及びｎはそれぞれ１〜３の整数を示し、Ｘ及びＹはそれぞれ水素原子、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基、ハロゲンを示す。）
前記化合物として具体的には、オクタン酸１,１−ジフェニルメチル、ノナン酸１,１−ジフェニルメチル、デカン酸１,１−ジフェニルメチル、ウンデカン酸１,１−ジフェニルメチル、ドデカン酸１,１−ジフェニルメチル、トリデカン酸１,１−ジフェニルメチル、テトラデカン酸１,１−ジフェニルメチル、ペンタデカン酸１,１−ジフェニルメチル、ヘキサデカン酸１,１−ジフェニルメチル、ヘプタデカン酸１,１−ジフェニルメチル、オクタデカン酸１,１−ジフェニルメチルを例示できる。 Furthermore, a compound represented by the following general formula (3) can also be used as the component (c).

(In the formula, R represents an alkyl group or alkenyl group having 8 or more carbon atoms, m and n each represents an integer of 1 to 3, X and Y represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, carbon, respectively. (The alkoxy group of Formula 1-4 is shown, and a halogen.)
Specific examples of the compound include 1,1-diphenylmethyl octanoate, 1,1-diphenylmethyl nonanoate, 1,1-diphenylmethyl decanoate, 1,1-diphenylmethyl undecanoate, 1,1-dodecanoic acid 1,1- Diphenylmethyl, tridecanoic acid 1,1-diphenylmethyl, tetradecanoic acid 1,1-diphenylmethyl, pentadecanoic acid 1,1-diphenylmethyl, hexadecanoic acid 1,1-diphenylmethyl, heptadecanoic acid 1,1-diphenylmethyl, octadecanoic acid An example is 1,1-diphenylmethyl.

（式中、Ｘは水素原子、炭素数１乃至４のアルキル基、メトキシ基、ハロゲン原子のいずれかを示し、ｍは１乃至３の整数を示し、ｎは１乃至２０の整数を示す。）
前記化合物としては、マロン酸と２−〔４−(４−クロロベンジルオキシ）フェニル）〕エタノールとのジエステル、こはく酸と２−（４−ベンジルオキシフェニル）エタノールとのジエステル、こはく酸と２−〔４−(３−メチルベンジルオキシ）フェニル）〕エタノールとのジエステル、グルタル酸と２−（４−ベンジルオキシフェニル）エタノールとのジエステル、グルタル酸と２−〔４−(４−クロロベンジルオキシ）フェニル）〕エタノールとのジエステル、アジピン酸と２−（４−ベンジルオキシフェニル）エタノールとのジエステル、ピメリン酸と２−（４−ベンジルオキシフェニル）エタノールとのジエステル、スベリン酸と２−（４−ベンジルオキシフェニル）エタノールとのジエステル、スベリン酸と２−〔４−(３−メチルベンジルオキシ）フェニル）〕エタノールとのジエステル、スベリン酸と２−〔４−(４−クロロベンジルオキシ）フェニル）〕エタノールとのジエステル、スベリン酸と２−〔４−(２，４−ジクロロベンジルオキシ）フェニル）〕エタノールとのジエステル、アゼライン酸と２−（４−ベンジルオキシフェニル）エタノールとのジエステル、セバシン酸と２−（４−ベンジルオキシフェニル）エタノールとのジエステル、１，１０−デカンジカルボン酸と２−（４−ベンジルオキシフェニル）エタノールとのジエステル、１，１８-オクタデカンジカルボン酸と２−（４−ベンジルオキシフェニル）エタノールとのジエステル、１，１８-オクタデカンジカルボン酸と２−〔４−(２−メチルベンジルオキシ）フェニル）〕エタノールとのジエステルを例示できる。 Furthermore, a compound represented by the following general formula (4) can also be used as the component (c).

(Wherein, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a methoxy group, or a halogen atom, m represents an integer of 1 to 3, and n represents an integer of 1 to 20)
Examples of the compound include a diester of malonic acid and 2- [4- (4-chlorobenzyloxy) phenyl)] ethanol, a diester of succinic acid and 2- (4-benzyloxyphenyl) ethanol, succinic acid and 2- Diester with [4- (3-methylbenzyloxy) phenyl)] ethanol, diester with glutaric acid and 2- (4-benzyloxyphenyl) ethanol, glutaric acid and 2- [4- (4-chlorobenzyloxy) Phenyl)] ethanol diester, adipic acid and 2- (4-benzyloxyphenyl) ethanol diester, pimelic acid and 2- (4-benzyloxyphenyl) ethanol diester, suberic acid and 2- (4- Diester with benzyloxyphenyl) ethanol, suberic acid and 2- [4- (3-methyl Benzyloxy) phenyl)] ethanol diester, suberic acid and 2- [4- (4-chlorobenzyloxy) phenyl)] ethanol diester, suberic acid and 2- [4- (2,4-dichlorobenzyloxy) ) Phenyl)] ethanol diester, azelaic acid and 2- (4-benzyloxyphenyl) ethanol diester, sebacic acid and 2- (4-benzyloxyphenyl) ethanol diester, 1,10-decanedicarboxylic acid And 2- (4-benzyloxyphenyl) ethanol diester, 1,18-octadecanedicarboxylic acid and 2- (4-benzyloxyphenyl) ethanol diester, 1,18-octadecanedicarboxylic acid and 2- [4- (2-Methylbenzyloxy) phenyl)] die with ethanol It can be exemplified ether.

（式中、Ｒは炭素数１乃至２１のアルキル基又はアルケニル基を示し、ｎは１乃至３の整数を示す。）
前記化合物としては、１，３−ビス（２−ヒドロキシエトキシ）ベンゼンとカプリン酸とのジエステル、１，３−ビス（２−ヒドロキシエトキシ）ベンゼンとウンデカン酸とのジエステル、１，３−ビス（２−ヒドロキシエトキシ）ベンゼンとラウリン酸とのジエステル、１，３−ビス（２−ヒドロキシエトキシ）ベンゼンとミリスチン酸とのジエステル、１，４−ビス（ヒドロキシメトキシ）ベンゼンと酪酸とのジエステル、１，４−ビス（ヒドロキシメトキシ）ベンゼンとイソ吉草酸とのジエステル、１，４−ビス（２−ヒドロキシエトキシ）ベンゼンと酢酸とのジエステル、１，４−ビス（２−ヒドロキシエトキシ）ベンゼンとプロピオン酸とのジエステル、１，４−ビス（２−ヒドロキシエトキシ）ベンゼンと吉草酸とのジエステル、１，４−ビス（２−ヒドロキシエトキシ）ベンゼンとカプロン酸とのジエステル、１，４−ビス（２−ヒドロキシエトキシ）ベンゼンとカプリル酸とのジエステル、１，４−ビス（２−ヒドロキシエトキシ）ベンゼンとカプリン酸とのジエステル、１，４−ビス（２−ヒドロキシエトキシ）ベンゼンとラウリン酸とのジエステル、１，４−ビス（２−ヒドロキシエトキシ）ベンゼンとミリスチン酸とのジエステルを例示できる。 Furthermore, a compound represented by the following general formula (5) can also be used as the component (c).

(In the formula, R represents an alkyl group or alkenyl group having 1 to 21 carbon atoms, and n represents an integer of 1 to 3).
Examples of the compound include a diester of 1,3-bis (2-hydroxyethoxy) benzene and capric acid, a diester of 1,3-bis (2-hydroxyethoxy) benzene and undecanoic acid, and 1,3-bis (2 -Hydroxyethoxy) benzene and lauric acid diester, 1,3-bis (2-hydroxyethoxy) benzene and myristic acid diester, 1,4-bis (hydroxymethoxy) benzene and butyric acid diester, 1,4 Diesters of bis (hydroxymethoxy) benzene and isovaleric acid, diesters of 1,4-bis (2-hydroxyethoxy) benzene and acetic acid, and 1,4-bis (2-hydroxyethoxy) benzene and propionic acid Diester, diester of 1,4-bis (2-hydroxyethoxy) benzene and valeric acid Diester of 1,4-bis (2-hydroxyethoxy) benzene and caproic acid, diester of 1,4-bis (2-hydroxyethoxy) benzene and caprylic acid, 1,4-bis (2-hydroxyethoxy) benzene And diester of capric acid, 1,4-bis (2-hydroxyethoxy) benzene and lauric acid, and 1,4-bis (2-hydroxyethoxy) benzene and myristic acid.

  Further, as the electron-accepting compound, a specific alkoxyphenol compound having a linear or side chain alkyl group having 3 to 18 carbon atoms may be used (Japanese Patent Laid-Open Nos. 11-129623 and 11-5973), Heat-coloring reversible thermochromic composition using hydroxybenzoic acid ester (Japanese Patent Laid-Open No. 2001-105732) or gallic acid ester (Japanese Patent Publication No. 51-44706, Japanese Patent Laid-Open No. 2003-253149) It is also possible to apply a microcapsule pigment enclosing an object (see FIG. 3).

  The blending ratio of the components (a), (b), and (c) depends on the concentration, the color change temperature, the color change form, and the type of each component. In general, the component ratio at which a desired color change characteristic is obtained is as follows. (B) Component 1 is in the range of (b) Component 0.1-50, preferably 0.5-20, (c) Component 1-800, preferably 5-200. Part by mass).

The reversible thermochromic composition comprising the above three components is used by being encapsulated in microcapsules. It does not deteriorate its function even when it comes in contact with chemically active substances such as acidic substances, basic substances, peroxides, or other solvent components. This is because the reversible thermochromic composition can be maintained in the same composition and exhibit the same action and effect under various use conditions.
The microcapsule pigment has an average particle size of 0.01 to 1.0 μm, preferably 0.1 to 0.65 μm, more preferably 0.1 to 0.49 μm, satisfying practicality.
When the average particle diameter exceeds 1.0 μm, the ratio of the microcapsule pigment that diffuses light is increased. As a result, the dried coating film (handwriting) on the writing surface in a state where the handwriting is erased becomes cloudy and is easily visually recognized as an afterimage.
If the average particle size is less than 0.01 μm, the afterimage is difficult to be visually recognized, but the color density of the handwriting before erasure is not sufficient because the color developability is poor.
In the system satisfying the average particle diameter of the microcapsule pigment in the range of 0.01 to 1.0 μm, the microcapsule pigment of 1.5 μm or more that easily diffuses light is less than 30% by volume in the total microcapsule pigment, By adjusting the volume to preferably 20% by volume or less, more preferably 15% by volume or less, it is possible to further prevent the dried coating film (handwriting) on the writing surface at the time of erasing from becoming cloudy and make it difficult to visually recognize the afterimage. Can do.
Furthermore, when the average particle diameter of the microcapsule pigment is 0.1 to 0.65 μm, the particles exceeding 1.5 μm in the microcapsule pigment are 15% by volume or less in the total microcapsule pigment, preferably 10 volumes. By adjusting to not more than%, more preferably not more than 5% by volume, it is possible to prevent the dried coating film (handwriting) on the writing surface at the time of decoloring from becoming cloudy and make it difficult to visually recognize the afterimage.
Further, when the average particle size of the reversible thermochromic microcapsule pigment is 0.1 to 0.49 μm, the particles exceeding 1.5 μm in the microcapsule pigment are preferably 15% by volume or less in the total microcapsule pigment, 10 volume% or less, more preferably 5 volume% or less, it is possible to prevent the dry paint film (handwriting) on the writing surface at the time of decoloring from becoming cloudy and make it difficult to visually recognize the afterimage. it can.
The particle size and particle size distribution were measured using a laser diffraction / scattering particle size distribution measuring apparatus (manufactured by Horiba, Ltd .; LA-300), and the average particle size (median diameter) based on the numerical values. Is calculated.
Here, it is preferable that the reversible thermochromic composition: wall film = 7: 1 to 1: 1 (mass ratio), preferably 6: 1 to 1: 1.
When the ratio of the reversible thermochromic composition to the wall film is larger than the above range, the thickness of the wall film becomes too thin, and the resistance to pressure and heat tends to decrease, and the ratio of the wall film to the reversible thermochromic composition When the value is larger than the above range, color density and sharpness during color development tend to be reduced.
The microencapsulation of the reversible thermochromic composition includes interfacial polymerization method, interfacial polycondensation method, in situ polymerization method, coacervate method, submerged curing coating method, phase separation method from aqueous solution, phase separation method from organic solvent There are a melt dispersion cooling method, an air suspension coating method, a spray drying method and the like, which are appropriately selected. Further, a secondary resin film may be provided on the surface of the microcapsule according to the purpose to impart durability, or the surface characteristics may be modified for practical use.
The microcapsule pigment may be in the form of a circular cross section or a noncircular cross section, or may be a mixture of a microcapsule pigment having a circular cross section and a noncircular cross section.

Next, a microcapsule pigment having a melting point in the range of −40 ° C. to + 95 ° C. and changing color from white to colorless encapsulating a compound selected from esters, ethers and ketones will be described.
The microcapsule pigment is a microcapsule pigment exhibiting a reversible thermochromic property of white opaque and colorless and transparent, and the inclusions become a solid state crystal at a temperature below the freezing point, scatter light and become a white state, and incident light. On the other hand, when the temperature is raised above the melting point of the inclusion by heating, the inclusion becomes liquid and the transmittance of incident light increases and becomes transparent.
The following are examples of esters included.
As esters having a total number of carbon atoms of 13 or more consisting of monovalent fatty acids and aliphatic monohydric alcohols or monohydric alcohols having an alicyclic ring, pentadecyl acetate, n-tridecyl butyrate, n-pentadecyl butyrate, and n-nonyl caprylate N-undecyl caprylate, n-lauryl caprylate, n-tridecyl caprylate, n-pentadecyl caprylate, cetyl caprylate, stearyl caprylate, n-propyl caprate, n-heptyl caprate, n-undecyl caprate N-lauryl caprate, n-tridecyl caprate, n-pentadecyl caprate, cetyl caprate, stearyl caprate, n-undecyl caproate, n-tridecyl caproate, n-pentadecyl caproate, n-nonyl caproate , N-undecyl caproate, capron Stearyl, n-hexyl caprylate, n-heptyl caprylate, n-octyl caprylate, methyl laurate, n-heptyl laurate, n-pentyl laurate, neopentyl laurate, 2-ethylhexyl laurate, n-octyl laurate N-nonyl laurate, n-decyl laurate, n-undecyl laurate, lauryl laurate, n-tridecyl laurate, myristyl laurate, n-pentadecyl laurate, stearyl laurate, cyclohexylmethyl laurate, myristic acid Methyl, myristate n-pentyl, myristate n-heptyl, myristate n-nonyl, myristate n-decyl, myristate n-undecyl, myristate lauryl, myristate n-tridecyl, myristate myristate , N-pentadecyl myristate, cetyl myristate, stearyl myristate, cyclohexyl myristate, methyl palmitate, ethyl palmitate, n-propyl palmitate, n-pentyl palmitate, neopentyl palmitate, n-heptyl palmitate, palmitate N-nonyl acid, n-decyl palmitate, n-undecyl palmitate, lauryl palmitate, n-tridecyl palmitate, myristyl palmitate n-pentadecyl palmitate, cetyl palmitate, cyclohexylmethyl palmitate stearyl palmitate, stearic acid Methyl, n-amyl stearate, n-heptyl stearate, neopentyl stearate, n-octyl stearate, n-nonyl stearate, n-de stearate Sil, n-undecyl stearate, n-tridecyl stearate, myristyl stearate, n-pentadecyl stearate, cetyl stearate, stearyl stearate, eicosyl stearate, n-docosyl stearate, cyclohexylmethyl stearate, oleyl stearate , Isostearyl stearate, cyclohexylmethyl stearate, methyl eicoate, n-amyl eicoate, n-heptyl eicoate, n-octyl eicoate, n-nonyl eicoate, n-decyl eicoate, n-undecyl eicoate N-tridecyl eicoate, n-pentadecyl eicoate, ethyl behenate, n-amyl behenate, n-heptyl behenate, neopentyl behenate, n-octyl behenate, n-nonyl behenate, n-decyl behenate The Phosphate n- undecyl, behenic acid n- tridecyl, behenate, myristyl behenate n- pentadecyl, cetyl behenate, cyclohexyl acetate stearyl, 2-cyclohexyl propionic acid stearyl, and neopentyl octylate and the like.

  Esters having a total carbon number of 18 or more consisting of an aliphatic divalent or polyvalent carboxylic acid and an aliphatic monohydric alcohol or a monohydric alcohol having an alicyclic ring include di-n-butyl sebacate, di-n-hexyl adipate, shu Di-n-nonyl oxalate, di-n-decyl oxalate, di-n-undecyl oxalate, dilauryl oxalate, di-n-tridecyl oxalate, dimyristyl oxalate, di-n-pentadecyl oxalate, dicetyl oxalate, di-n-oxalate -Heptadecyl, distearyl oxalate, dilauryl malonate, di-n-tridecyl malonate, dimyristyl malonate, di-n-pentadecyl malonate, dicetyl malonate, di-n-heptadecyl malonate, distearyl malonate, di-n-succinate Nonyl, di-n-decyl succinate, di-n-undecyl succinate, dilauryl succinate, succinate Di-n-tridecyl succinate, dimyristyl succinate, di-n-pentadecyl succinate, dicetyl succinate, diheptadecyl succinate, distearyl succinate, di-n-decyl glutarate, di-n-decyl glutarate, dilauryl glutarate, glutaric acid Di-n-tridecyl, dimyristyl glutarate, di-n-pentadecyl glutarate, dicetyl glutarate, di-n-heptadecyl glutarate, distearyl glutarate, di-n-decyl adipate, di-n-undecyl adipate, dilauryl adipate, Di-n-tridecyl adipate, dimyristyl adipate, di-n-pentadecyl adipate, dicetyl adipate, di-n-heptadecyl adipate, distearyl adipate, di-n-docosyl adipate, di-n-decyl pimelate, pimelic acid Jin-un Sil, dilauryl pimelate, di-n-tridecyl pimelate, dimyristyl pimelate, di-n-pentadecyl pimelate, dicetyl pimelate, di-n-heptadecyl pimelate, distearyl pimelate, di-n-decyl suberate, di-suberate n-undecyl, dilauryl suberate, di-n-tridecyl suberate, dimyristyl suberate, di-n-nonyl sebacate, di-n-decyl sebacate, di-undecyl sebacate, dilauryl sebacate, di-n-tridecyl sebacate , Dimyristyl sebacate, di-n-pentadecyl sebacate, dicetyl sebacate, di-n-heptadecyl sebacate, distearyl sebacate, di-n-pentadecyl suberate, dicetyl suberate, di-n-heptadecyl suberate, distearyl suberate , Di-n-decyl azelate, di-undecyl azelate, dilauryl azelate, di-n-tridecyl azelate, dimyristyl azelate, di-n-pentadecyl azelate, dicetyl azelate, di-n-heptadecyl azelate, azelaic acid Examples include distearyl, di-n-octyl 1,18 octadecylmethylenedicarboxylate, dicyclohexyl 1,18 octadecylmethylenedicarboxylate, and dineopentyl 1,18 octadecylmethylenedicarboxylate.

  As esters having a total of 18 or more carbon atoms composed of aliphatic divalent or polyhydric alcohol or alicyclic divalent and polyhydric alcohol and monovalent fatty acid, ethylene glycol dicaprylate, ethylene glycol dicaprate, ethylene Glycol diundecanoate, ethylene glycol dilaurate, ethylene glycol ditridecanoate, ethylene glycol dimyristic ester, ethylene glycol dipentadecanoate, ethylene glycol dipalmitate, ethylene glycol diheptadecanoate, ethylene Glycol distearate, 1,3-propanediol dicaprylate, 1,3-propanediol dicaprate, 1,3-propanediol diunde Acid ester, 1,3-propanediol dilauric acid ester, 1,3-propanediol ditridecanoic acid ester, 1,3-propanediol dimyristic acid ester, 1,3-propanediol dipentadecanoic acid ester, 1, 3-propanediol dipalmitate, 1,3-propanediol diheptadecanoate, 1,3-propanediol distearate, 1,4-butanediol dicaprylate, 1,4-butanediol dicapric acid Ester, 1,4-butanediol diundecanoate, 1,4-butanediol dilaurate, 1,4-butanediol ditridecanoate, 1,4-butanediol dimyristate, 1,4- Butanediol dipentadecanoate 1,4-butanediol dipalmitate, 1,4-butanediol diheptadecanoate, 1,4-butanediol distearate, 1,5-pentanediol dicaprate, 1,5- Pentanediol diundecanoic acid ester, 1,5-pentanediol dilauric acid ester, 1,5-pentanediol ditridecanoic acid ester, 1,5-pentanediol dimyristic acid ester, 1,5-pentanediol dipentadecanoic acid ester 1,5-pentanediol dipalmitate, 1,5-pentanediol diheptadecanoate, 1,5-pentanediol distearate, 1,6-hexanediol dicaprate, 1,6-hexane Diol diundecanoate 1,6-hexanediol dilauric acid ester, 1,6-hexanediol ditridecanoic acid ester, 1,6-hexanediol dimyristic acid ester, 1,6-hexanediol dipentadecanoic acid ester, 1,6- Hexanediol dipalmitate, 1,6-hexanediol diheptadecanoate, 1,6-hexanediol distearate, 1,7-pentanediol dicaprate, 1,7-pentanediol diundecanoate 1,7-pentanediol dilauric acid ester, 1,7-pentanediol ditridecanoic acid ester, 1,7-pentanediol dimyristic acid ester, 1,7-pentanediol dipentadecanoic acid ester, 1,7-pentane Diol dipalmitic acid Steal, 1,7-pentanediol diheptadecanoate, 1,7-pentanediol distearate, 1,8-octanediol dicaprate, 1,8-octanediol diundecanoate, 1,8- Octanediol dilaurate, 1,8-octanediol ditridecanoate, 1,8-octanediol dimyristate, 1,8-octanediol dipentadecanoate, 1,8-octanediol dipalmitate 1,8-octanediol diheptadecanoic acid ester, 1,8-octanediol distearic acid ester, 1,9-nonanediol dicapric acid ester, 1,9-nonanediol diundecanoic acid ester, 1,9-nonane Diol dilaurate 1,9-nonanediol ditridecanoic acid ester, 1,9-nonanediol dimyristic acid ester, 1,9-nonanediol dipentadecanoic acid ester, 1,9-nonanediol dipalmitic acid ester, 1,9- Nonanediol diheptadecanoic acid ester, 1,9-nonanediol distearic acid ester, 1,10-decanediol dicaprylic acid ester, 1,10-decanediol dicapric acid ester, 1,10-decanediol diundecanoic acid ester, 1,10-decanediol dilauric acid ester, 1,10-decanediol ditridecanoic acid ester, 1,10-decanediol dimyristic acid ester, 1,10-decanediol dipentadecanoic acid ester, 1,10-decanediol Dipalmitate, 1,10-decanediol diheptadecanoic acid ester, 1,10-decanediol distearic acid ester, 1,5-pentanediol distearate, 1,2,6-hexanetriol dimyristate, pentaerythritol trimyristate , Pentaerythritol tetralaurate, 1,4-cyclohexanediol dimyristyl, 1,4-cyclohexanediol didecyl, 1,4-cyclohexanediol dimyristyl, 1,4-cyclohexanediol distearyl, 1,4-cyclohexanedi Examples include methanol dilaurate and 1,4-cyclohexanedimethanol dimyristate.

  As esters having a total number of carbon atoms of 24 or more consisting of a dihydric alcohol having an aromatic ring and a monovalent fatty acid, xylylene glycol dicaprylate, xylylene glycol dicaprate, xylylene glycol diundecanoate, xylylene glycol Dilauric acid ester, xylylene glycol ditridecanoic acid ester, xylylene glycol dimyristic acid ester, xylylene glycol dipentadecanoic acid ester, xylylene glycol dipalmitic acid ester, xylylene glycol diheptadecanoic acid ester, xylylene glycol distearic acid ester Acid ester etc. are mentioned.

  Esters having a total carbon number of 15 or more consisting of a monovalent carboxylic acid having an aromatic ring and an aliphatic monohydric alcohol or a monohydric alcohol having an alicyclic ring, hexyl 3,5-dimethylbenzoate, decyl 2-methylbenzoate Lauryl 2-methylbenzoate, myristyl 2-methylbenzoate, stearyl 2-methylbenzoate, cetyl 4-tert-butylbenzoate, behenyl 4-cyclohexylbenzoate, myristyl 4-phenylbenzoate, 4-octylbenzoic acid Lauryl, stearyl 3-ethylbenzoate, decyl 4-isopropylbenzoate, stearyl 4-benzoyl stearyl benzoate, stearyl 4-chlorobenzoate, myristyl 3-bromobenzoate, stearyl 2-chloro-4-bromobenzoate, 3, Decyl 4-dichlorobenzoate, octyl 2,4-dibromobenzoate Cetyl 3-nitrobenzoate, cyclohexylmethyl 4-aminobenzoate, cetyl 4-diethylaminobenzoate, stearyl 4-anilinobenzoate, decyl 4-methoxybenzoate, cetyl 4-methoxybenzoate, 4-butoxybenzoic acid Octyl, cetyl 4-hydroxybenzoate, stearyl p-chlorophenylacetate, cetyl p-chlorophenylacetate, neopentyl salicylate, stearyl 2-naphthoate, cetyl benzylate, stearyl benzylate, decyl 3-benzoylpropionate, stearyl benzoate, benzoate Examples include acid myristyl, cyclohexylmethyl 2-benzoylpropionate, and cyclohexylmethyl cinnamate.

  Esters having a total carbon number of 14 or more consisting of a monovalent carboxylic acid having an aromatic ring and a monohydric alcohol having an aromatic ring include benzyl salicylate, 4-methoxymethylphenylmethyl salicylate, 4-chlorophenylmethyl benzoate, and cinnamic acid. Examples include benzyl, phenyl 4-tert-butylbenzoate, 4-chlorobenzyl 2-methylbenzoate, 4-methoxyphenylmethyl benzoate, and the like.

  As esters having a total number of carbon atoms of 15 or more consisting of monohydric fatty acids and monohydric alcohols having aromatic rings, 4-chlorophenylmethyl caprylate, 4-chlorophenylmethyl caprate, 4-methoxyphenylmethyl laurate, 4-myristate 4- Methoxyphenylmethyl, 4-nitrophenylmethyl stearate, 4-methylphenylmethyl caprate, 2-chlorophenylmethyl myristate, 4-chlorophenyl 11-bromolaurate, 4-isopropylphenyl stearate, stearyl 2-naphthoate, benzyl Examples include cetyl acid, stearyl benzylate, benzyl caproate, benzyl palmitate, 3-phenylpropyl stearate, and phenyl 11-bromolaurate.

  Examples of the ester having 16 or more carbon atoms composed of a divalent fatty acid and a monohydric alcohol having an aromatic ring include dibenzyl sebacate, dineopentyl 4,4'-diphenyldicarboxylate, and the like.

Next, ethers will be exemplified.
Examples of aliphatic ethers having a total carbon number of 16 or more include dioctyl ether, diniethylhexyl ether, didecyl ether, didodecyl ether, ditridecyl ether, ditetradecyl ether, dipentadecyl ether, dihexadecyl ether, diheptadecyl. Examples include ether and dioctadecyl ether.
Examples of ethers having an aromatic ring having a total carbon number of 11 or more include benzyl isoamyl ether, diphenyl ether, ethylene glycol diphenyl ether, diisopropyl benzyl ether and the like.

Next, ketones will be exemplified.
As aliphatic ketones having a total carbon number of 10 or more, 2-decanone, 3-decanone, 4-decanone, 2-undecanone, 3-undecanone, 4-undecanone, 5-undecanone, 6-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, Examples include 2-nonadecanone, 10-nonadecanone, 2-eicosanone, 11-heneicosanone, 2-docosanone, laurone, stearone, and cyclodecanone.
As ketones having an aromatic ring or alicyclic ring having a total carbon number of 10 or more, benzylacetophenone, benzylphenylketone, n-octadecanophenone, n-heptadecanophenone, n-hexadecanophenone, n-tetradecano Phenone, n-tridecanophenone, laurophenone, n-undecanophenone, n-decanophenone, 4'-n-octylacetophenone, n-nonanophenone, 4'-n-heptylacetophenone, n-octanophenone, 4'- n-hexylacetophenone, 4′-cyclohexylacetophenone, 2-methylbenzophenone, dicyclohexylketone, 4-tert-butylpropiophenone, n-heptanophenone, 4′-n-pentylacetophenone, cyclohexylphenylketone, 2-benzylidenecyclo Xanone, benzophenone, cyclodecanone, 2-n-heptylcyclohexanone, 2-cyclohexylcyclohexanone, 2- (1-cyclohexyl) cyclohexanone, benzyl n-butyl ketone, 4'-n-butylacetophenone, n-hexanophenone, 4-isobutylacetophenone , Cyclopentylphenylketone, 4-phenylcyclohexanone, 1-acetephthalanone, 2-acetephthalanone, 4-n-pentylcyclohexanone, benzylisopropylketone, 4′-n-propylacetophenone, 2 ′, 4 ′, 6′-trimethylacetophenone, cyclo Butyl phenyl ketone, 2 ′, 4′-dimethylacetophenone, 2 ′, 5′-dimethylacetophenone, 4′-ethylacetophenone, isopropyl phenyl ketone, 4′-methyl group Piophenone, 1-phenyl-2-butanone, phenyl n-propioketone, cyclopropylphenylketone, phenylpropenylketone, 2-amino-4′-chlorobenzophenone, 2-amino-5-chlorobenzophenone, 4-fluorobenzophenone, 2- Amino-2 ′, 5-chlorobenzophenone, 4-chloro-4′-hydroxybenzophenone, 2-chlorobenzophenone, 4-chlorobenzophenone, 2,4′-difluorobenzophenone, 4,4′-difluorobenzophenone, 2,4- Dichlorobenzophenone, 2,4′-dichlorobenzophenone, 4,4′-dichlorobenzophenone, 2,3,4,5,6, -pentafluorobenzophenone, decafluorobenzophenone, 3-3′diaminobenzophenone, 3-4 diaminobenzo Phenone, 4,4′diaminobenzophenone, 2-aminobenzophenone, 4-aminobenzophenone, 3,4-dimethoxyphenyl cycetone, 2 ′, 3 ′, 4′-trimethoxyacetophenone, 3 ′, 4 ′, 5′- Examples include trimethoxyacetophenone.

A method of encapsulating a crystalline compound having a melting point in the range of −40 ° C. to + 95 ° C. selected from esters, ethers, and ketones in a microcapsule is the same as the above-described microcapsule pigment that changes color from colorless to colorless. The method is mentioned.
The microcapsule pigment has an average particle size of 0.01 to 1.0 μm, preferably 0.1 to 0.65 μm, more preferably 0.1 to 0.49 μm, satisfying practicality.
When the average particle diameter exceeds 1.0 μm, the ratio of the microcapsule pigment that diffuses light is increased, so that the melting point contained in the microcapsule pigment in the handwriting is in the range of −40 ° C. to + 95 ° C. , A compound selected from esters, ethers, and ketones is changed from white to colorless, and as a result, the dry paint film (handwriting) on the writing surface in a state where the handwriting is erased becomes cloudy and is easily recognized as an afterimage. .
Further, when the average particle size is less than 0.01 μm, the afterimage is difficult to be visually recognized, but since the color developability is poor, it is difficult to obtain a sufficient pastel handwriting before erasure.
In the system satisfying the average particle diameter of the microcapsule pigment in the range of 0.01 to 1.0 μm, the microcapsule pigment of 1.5 μm or more that easily diffuses light is less than 30% by volume in the total microcapsule pigment, By adjusting the volume to preferably 20% by volume or less, more preferably 15% by volume or less, it is possible to further prevent the dried coating film (handwriting) on the writing surface at the time of erasing from becoming cloudy and make it difficult to visually recognize the afterimage. Can do.
Furthermore, when the average particle diameter of the microcapsule pigment is 0.1 to 0.65 μm, the particles exceeding 1.5 μm in the microcapsule pigment have a volume of 15% by volume or less in the total microcapsule pigment, preferably 10 volumes. By adjusting to not more than%, more preferably not more than 5% by volume, it is possible to prevent the dried coating film (handwriting) on the writing surface at the time of decoloring from becoming cloudy and make it difficult to visually recognize the afterimage.
Further, when the average particle size of the reversible thermochromic microcapsule pigment is 0.1 to 0.49 μm, the particles exceeding 1.5 μm in the microcapsule pigment are preferably 15% by volume or less in the total microcapsule pigment, 10 volume% or less, more preferably 5 volume% or less, it is possible to prevent the dry paint film (handwriting) on the writing surface at the time of decoloring from becoming cloudy and make it difficult to visually recognize the afterimage. it can.
The particle diameter and particle size distribution are measured by the same method as for the microcapsule pigment that changes from colored to colorless.
Here, a crystalline compound having a melting point in the range of −40 ° C. to + 95 ° C., selected from esters, ethers and ketones: wall membrane = 7: 1 to 1: 1 (mass ratio), preferably 6 : It is preferable to satisfy | fill the range of 1-1: 1.
When the ratio of the encapsulated compound to the wall film is larger than the above range, the thickness of the wall film becomes too thin, and the resistance to pressure and heat tends to decrease, and the ratio of the wall film to the compound becomes larger than the above range. It tends to cause a decrease in color density and sharpness during color development.

The weight ratio of the microcapsule pigment that changes from colored to colorless and the microcapsule pigment that changes from white to colorless is 1: 1 to 1:25, preferably 1: 5 to 1:25, more preferably 1: 5. When the microcapsule pigment that changes from white to colorless with respect to the microcapsule pigment that changes from colored to colorless is less than 1, it is difficult to obtain a pastel-like handwriting, while when it exceeds 25, Since it becomes a pale white handwriting, it becomes poor in practicality.

As a medium used for the ink composition, water and, if necessary, a water-soluble organic solvent are used.
Examples of the water-soluble organic solvent include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, and 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-pyrrolidone, N-methyl-2- Pyrrolidone, or the like is used.
Note that the microcapsule pigment encapsulating the reversible thermochromic composition having a large hysteresis width has a specific gravity of more than 1, so that the water-soluble organic solvent to be applied is preferably more than 1.1.
Examples of the ink composition include a shear-thinning ink containing a shear-thinning agent, a cohesive ink containing a water-soluble polymer flocculant in a vehicle, and a pigment suspended in a loosely-aggregated state. it can.

By adding the shear thinning agent, it is possible to suppress aggregation and sedimentation of the pigment, and it is possible to suppress bleeding of the handwriting, so that a good handwriting can be formed.
Furthermore, when the writing instrument filled with the ink composition is in the form of a ballpoint pen, ink leakage from the gap between the ball and the ball holding portion when not in use is prevented, or the writing tip is left facing upward (upright state). In this case, the back flow of ink can be prevented.
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 ethylene alkyl ethers, 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.

Examples of the water-soluble polymer flocculant include polyvinyl pyrrolidone, polyethylene oxide, and water-soluble polysaccharides.
Examples of the water-soluble polysaccharides include tragacanth gum, guar gum, pullulan, cyclodextrin, water-soluble cellulose derivatives and the like. Specific examples of water-soluble cellulose derivatives include methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose. Etc.
Two or more kinds of the polymer flocculants can be used in combination.

Combining the polymer flocculant with a comb polymer dispersant having a carboxyl group in the side chain and an organic nitrogen sulfur compound improves dispersibility of loose aggregates of microcapsule pigments by the polymer flocculant. be able to.
The comb polymer dispersant having a carboxyl group in the side chain is not particularly limited as long as it is a comb polymer compound having a plurality of carboxyl groups in the side chain, but a plurality of carboxyl groups in the side chain. An acrylic polymer compound having the formula:

When the organic nitrogen sulfur compound is used in combination, when the ink composition is filled in a writing instrument and put to practical use, the precipitation of the microcapsule pigment due to vibration is further suppressed.
This further improves dispersibility in which loose aggregates of microcapsule pigments are dispersed by a comb-type polymer dispersant having a carboxyl group in the side chain.
As the organic nitrogen sulfur compound, a compound selected from thiazole compounds, isothiazole compounds, benzothiazole compounds, and benzoisothiazole compounds is used.
Specific examples of the organic nitrogen sulfur compound include 2- (4-thiazoyl) -benzimidazole (TBZ), 2- (thiocyanatomethylthio) -1,3-benzothiazole (TCMTB), 2-methyl-4-isothiazoline- One or more compounds selected from 3-one and 5-chloro-2-methyl-4-isothiazolin-3-one are used, preferably 2- (4-thiazoyl) -benzimidazole (TBZ), 2 One or more compounds selected from -methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one are used.
As the organic nitrogen sulfur compound, manufactured by Permachem Asia Co., Ltd., trade names: Topside 88, 133, 170, 220, 288, 300, 400, 500, 600, 700Z, 800, 950, manufactured by Hokuko Sangyo Co., Ltd., trade names: Hokuster HP, E50A, Hokuside P200, 6500, 7400, MC, 369, and R-150.
The mass ratio of the comb-type polymer dispersant having a carboxyl group in the side chain and the organic nitrogen sulfur compound is 1: 1 to 1:10, preferably 1: 1 to 1: 5, and satisfies the above range. Thus, the dispersibility of loose aggregates of the microcapsule pigment and the suppression of sedimentation of the microcapsule pigment due to vibration can be sufficiently expressed.

Furthermore, addition of a water-soluble resin can provide adhesion and viscosity to the paper surface, and increase the stability of the above-described comb polymer dispersant having a carboxyl group in the side chain and organic nitrogen sulfur compound in ink. Functions can be added.
Examples of the water-soluble resin include alkyd resins, acrylic resins, styrene maleic acid copolymers, cellulose derivatives, polyvinyl pyrrolidone, polyvinyl alcohol, dextrin, and preferably polyvinyl alcohol is used.
Furthermore, when a partially saponification type polyvinyl alcohol having a saponification degree of 70 to 89 mol% is used as the polyvinyl alcohol, the ink composition is more soluble even in an acidic region, and thus is more preferably used.
The addition amount of the water-soluble resin is 0.3 to 3.0% by mass, preferably 0.5 to 1.5% by mass in the ink composition.

The ink composition does not contain the water-soluble polymer flocculant, specifically, a water-soluble organic solvent, a comb-type polymer dispersant having a carboxyl group in the side chain, an organic nitrogen sulfur compound, and a water-soluble By containing the resin, an ink composition having excellent dispersibility of the microcapsule pigment can be obtained.
Glycerin is preferably used as the water-soluble organic solvent, and can be blended in an amount of 5 to 40% by weight, preferably 25 to 40% by weight, more preferably 30 to 35% by weight based on the total amount of the ink composition.
For the comb polymer dispersant having a carboxyl group in the side chain, the organic nitrogen sulfur compound, and the water-soluble resin, the same compounds as described above are used.

  In addition, when the ink composition 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, a 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 prevent wear of the ball seat by adding a lubricant such as a phosphoric acid diester or a metal salt, ammonium salt, amine salt or alkanolamine salt thereof.

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 night as necessary Rust prevention agent such as light, saponin, coalic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetra Preservatives or fungicides such as chloro-4- (methylsulfonyl) pyridine, urea, nonionic surfactants, reduced or non-reduced starch hydrolysates, oligosaccharides such as trehalose, sucrose, cyclodextrin, glucose, dextrin , Sorbit, N'nitto, wetting agents such as sodium pyrophosphate, defoamers, dispersing agents, a surfactant may be added a fluorine-based surfactant or a nonionic improve the ink permeability.
Further, by adding a sulfur-based extreme pressure additive such as 2,5-dimercapto-1,3,4-thiadiazole and / or a salt thereof, the ink was once frozen even in the acidic or alkaline region. It is possible to suppress poor dispersion and aggregation of the microcapsule pigment that occurs after the ink is thawed again, thereby preventing an increase in ink viscosity, accompanying handwriting blurring and lightening, and preventing ball corrosion.

The ink composition is used by filling a writing instrument such as a marking pen or a ballpoint pen with a pen body attached to the writing tip.
When filling the ball-point pen, the structure and shape of the ball-point pen itself are not particularly limited. For example, the ball-point pen has an ink containing tube filled with shear-thinning ink in the shaft cylinder, and the ink containing tube has a ball at the tip portion. An example is a ballpoint pen that communicates with a pen body attached to the ink cartridge and has a liquid stopper for backflow prevention in close contact with the end face of the ink.
The ball pen body will be described in more detail. A pen body in which a ball is held in a ball holding portion in which the vicinity of the tip of a metal pipe is pressed and deformed inward from the outer surface, or a metal material is cut by a drill or the like. A pen body formed by holding a ball in a ball holding section formed by processing, a pen body provided with a resin ball receiving seat inside a metal or plastic ball holding section, or held by the pen body A ball or the like that is urged forward by a spring body 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.
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 composition.
In addition to directly connecting the pen body to the ink storage tube, the ink storage tube and the pen body may be connected via a connecting member.
The ink storage tube may be in the form of a refill, and the refill may be accommodated in a shaft cylinder made of resin, metal, or the like, or the shaft cylinder itself with a pen body attached to the tip is used as an ink container. The shaft cylinder may be filled directly with ink.
In addition, when the ink composition is housed in a retractable ballpoint pen, the structure and shape of the retractable ballpoint pen are not particularly limited, and the writing tip provided on the ballpoint pen refill is exposed to the outside air. Any structure can be used as long as it is housed in the cylinder and the writing tip protrudes from the shaft cylinder opening by the operation of the retracting mechanism.
Examples of the operation method of the retracting mechanism include a knock type, a rotary type, and a slide type.
The knock type has a knock portion on the rear end portion of the shaft tube and the side surface of the shaft tube, and a configuration in which the ball-point pen tip is projected and retracted from the front end opening portion of the shaft tube by pressing the knock portion, or a clip portion provided on the shaft tube A configuration in which the ball-point pen tip is projected and retracted from the front end opening of the shaft cylinder can be exemplified by pressing.
The rotary type has a rotating part at the rear part of the shaft cylinder, and a configuration in which the ball-point pen tip is projected and retracted from the front end opening part of the shaft cylinder by rotating the rotating part can be exemplified.
The slide type has a slide part on the side surface of the shaft tube, and by operating the slide, the ballpoint pen tip is projected and retracted from the opening at the front end of the shaft tube, or by sliding a clip part provided on the shaft tube, A configuration in which the ball-point pen tip is projected and retracted from the front end opening of the shaft cylinder can be exemplified.
The retractable ballpoint pen is a compound type retractable ballpoint pen in which a plurality of ballpoint pen refills are accommodated in a shaft cylinder, and the writing tip of one of the ballpoint pen refills protrudes and retracts from the opening at the front end of the shaft cylinder by the operation of the retractable mechanism. May be.

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, A polyether modified silicone oil, a fatty acid modified silicone oil, etc. are mentioned, 1 type, or 2 or more types can also be used together.
The non-volatile liquid and / or the hardly volatile liquid is preferably thickened to a suitable viscosity by adding a thickener. As the thickener, the surface is treated with hydrophobic silica, and the surface is methylated. Fine particle silica, aluminum silicate, swellable mica, hydrophobic thickener such as bentonite and montmorillonite, fatty acid metal soap such as magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, tribenzylidene sorbitol, Examples thereof include fatty acid amide, amide-modified polyethylene wax, hydrogenated castor oil, dextrin compounds such as fatty acid dextrin, and cellulose compounds.
Furthermore, the liquid ink backflow prevention body and the solid ink backflow prevention body can be used in combination.

When filling the marking pen with the ink composition, the structure and shape of the marking pen itself are not particularly limited. For example, an ink occlusion body consisting of a fiber bundling body is built in the shaft cylinder to form a capillary gap. A marking pen body made of a processed fiber body is attached to a shaft cylinder directly or via a relay member, and cohesive ink is applied to the ink storage body of the marking pen formed by connecting the ink storage body and the pen body. Examples thereof include a marking pen impregnated, a marking pen in which a pen body and an ink storage tube are arranged via a valve body opened by pressing of the pen body, and ink is directly stored in the ink storage tube.
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 ink occlusion body is formed by converging crimped fibers in the longitudinal direction, and is configured to be included in a covering body such as a plastic cylinder or a film and to adjust the porosity to a range of approximately 40 to 90%. Is done.
The valve body can be of a general-purpose pumping type, but is preferably set to a spring pressure that can be released by writing pressure.

  Furthermore, the form of the ballpoint pen or the marking pen is not limited to the one described above, but a composite writing instrument (a double-headed type or a nib with a pen body having a different shape or a pen point for deriving different colors of ink). It may be a pay-out type or the like.

The handwriting formed by the writing instrument can be discolored by rubbing with a finger, heating, or application of a cooling / heating tool.
Examples of the heating tool include an energization heating color changing tool equipped with a resistance heating element, a heating color changing tool filled with hot water, and a hair dryer. Preferably, a friction member is used as a means capable of changing color by a simple method. Used.
As the friction 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 suitable.
Although it is possible to rub the handwriting using an eraser, the above-mentioned friction member that hardly generates erase scraps is preferably used because erase scraps are generated during friction.
As the material of the friction member, silicone resin, SEBS resin (styrene ethylene butadiene styrene block copolymer), polyester resin, or the like is used.
The friction member can be obtained by combining a writing instrument and a member of arbitrary shape (friction body) separately to obtain a writing instrument set. However, by providing the writing instrument with a friction member, it is excellent in portability.
In the case of a writing instrument having a cap, the location where the friction member is provided is not particularly limited. For example, when the cap itself is formed of a friction member, the shaft tube itself is formed of a friction member, or a clip is provided. The clip itself can be formed of a friction member, or the friction member can be provided at the tip end (top) of the cap or the rear end of the shaft cylinder (the portion where the writing tip is not provided).
In the case of a retractable writing instrument, the location where the friction member is provided is not particularly limited, but for example, the shaft cylinder itself is formed with a friction member, or when the clip is provided, the clip itself is formed with a friction member, A friction member can be provided in the vicinity of the shaft tube opening, the rear end portion of the shaft tube (the portion where the writing tip portion is not provided) or the knock portion.
Examples of the cooling / heating tool include a cooling / heating discoloration tool using a Peltier element, a cooling / heating discoloration tool filled with a coolant such as cold water and ice pieces, a refrigerator and a freezer.

Examples of the present invention are shown below, but the present invention is not limited thereto.
In addition, the part in an Example is a mass part.
Example 1
Preparation of microcapsule pigment which changes color from colorless to colorless (i) 4,5,6,7-tetrachloro-3- [4- (dimethylamino) -2-methylphenyl] -3- (1-ethyl-) as component 2.0 parts of 2-methyl-1H-indol-3-yl) -1 (3H) -isobenzofuranone, 4,4 '-(2-ethylhexane-1,1-diyl) diphenol as component (b) 3.0 parts, 5.0 parts of 2,2-bis (4′-hydroxyphenyl) -hexafluoropropane, and (c) color memory consisting of 50.0 parts of 4-benzyloxyphenylethyl caprate as the component A microcapsule pigment suspension containing the reversible thermochromic composition was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 1.0 μm, the complete color erasing temperature is 55 ° C., the complete color development temperature is −30 ° C., and particles exceeding 1.5 μm are 26% by volume in the total microcapsule pigment. The color changes from blue to colorless.

Preparation of microcapsule pigment which changes color from white to colorless 2,2-bis (4′-hydroxyphenyl) hexafluoropropane 3.0 parts, 1,1-bis (4-hydroxyphenyl) decane 3.0 parts, capric acid A microcapsule pigment suspension containing a composition comprising 50.0 parts of stearyl was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 1.0 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −30 ° C., and particles exceeding 1.5 μm are 26% by volume in the total microcapsule pigment. The color changes from white to colorless.

Preparation of ink composition for pastel reversible thermochromic writing instrument: 3.0 parts of microcapsule pigment that changes from colored to colorless (previously cooled to -30 ° C or less to develop blue), white to colorless 22.0 parts of microcapsule pigment (previously cooled to −30 ° C. or less to develop a white color), 0.5 parts of hydroxyethyl cellulose, comb-type polymer dispersant [manufactured by Nippon Lubrizol Corporation, trade name : Solsperse 43000], 0.2 parts, organic nitrogen sulfur compound [made by Hokuko Chemical Co., Ltd., trade name: Hokuside R-150, 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl- 4-isothiazolin-3-one mixture] 1.0 parts, polyvinyl alcohol 0.5 parts, glycerin 25.0 parts, antifoaming agent 0.02 parts, water 47.78 parts mixed and passed. A tell-tone reversible thermochromic ink composition for writing instruments was obtained.

Writing instrument production (see Fig. 4)
The ink occlusion body 2 in which a polyester sliver is coated with a synthetic resin film is impregnated with the ink composition, accommodated in a shaft cylinder 4 made of polypropylene resin, and a marking made of polyester fiber at the tip of the shaft cylinder via a holder 5 The pen body 3 (bullet type) was assembled in a connected state, and the cap 6 was attached to obtain a writing instrument 1 (marking pen).
A SEBS resin is attached as a friction member 7 to the rear end portion of the shaft cylinder.

Pastel blue handwriting was formed on white paper using the writing instrument.
The handwriting had a pastel blue color at room temperature (25 ° C.). When the handwriting was rubbed using a friction member attached to the shaft tube, the handwriting was discolored and became colorless, and this state was maintained at room temperature.
In addition, pastel blue handwriting was formed on black paper using the writing instrument.
The handwriting was blue at room temperature (25 ° C.), and when rubbed with a SEBS friction member attached to the shaft tube, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 2
Preparation of microcapsule pigment which changes color from colorless to colorless (I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine as component 1.0 part of -5,1 '(3'H) -isobenzofuran] -3-one, and 4,4'-(2-ethylhexane-1,1-diyl) diphenol 3.0 as component (b) Part, 2,2-bis (4'-hydroxyphenyl) -hexafluoropropane 5.0 parts, (c) reversible thermal discoloration having color memory composed of 50.0 parts 4-benzyloxyphenylethyl caprate A microcapsule pigment suspension encapsulating the composition was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 0.8 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −40 ° C., and the particles exceeding 1.5 μm are 12% by volume in all the microcapsule pigments. The color changes from pink to colorless.

Preparation of microcapsule pigment which changes color from white to colorless 2,2-bis (4′-hydroxyphenyl) hexafluoropropane 3.0 parts, 1,1-bis (4-hydroxyphenyl) decane 3.0 parts, capric acid A microcapsule pigment suspension containing a composition comprising 50.0 parts of stearyl was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 0.8 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −42 ° C., and particles exceeding 1.5 μm are 12% by volume in the total microcapsule pigment. The color changes from white to colorless.

Preparation of ink composition for pastel reversible thermochromic writing utensil The microcapsule pigment (previously cooled to -40 ° C. or less and colored pink), microcapsule pigment that changes from white to colorless ( 24.0 parts previously cooled to −40 ° C. or less to develop a white color), comb-shaped polymer dispersant [manufactured by Nippon Lubrizol Co., Ltd., trade name: Solsperse 43000], 0.4 parts of organic nitrogen sulfur compound [Product name: Hokuside R-150, a mixture of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one manufactured by Hokuko Chemical Co., Ltd.] 1.0 Part, polyvinyl alcohol 0.5 part, glycerin 35.0 parts, antifoaming agent 0.02 part, and water 33.08 parts were mixed to obtain an ink composition for a pastel reversible thermochromic writing instrument.

Writing instrument production (see Fig. 5)
The ink composition 8 and the stirrer 9 (SUS-304 ferritic stainless steel ball, diameter 3 mm) are built in the shaft cylinder 4, and the pen body 3 (chisel type) is attached to the tip via the holder 5. A writing instrument 1 (marking pen) was obtained by attaching the cap 6.
A valve mechanism 10 is provided in the shaft cylinder, and the valve mechanism includes a valve seat, a valve body, and a metal spring that urges the valve body to press against the valve seat. The valve opens with the pressure applied to the pen body at the time.
A SEBS resin is attached as a friction member 7 to the rear end portion of the shaft cylinder.

Pastel pink handwriting was formed on the paper surface using the writing instrument.
The handwriting had a pastel pink color at room temperature (25 ° C.). When the handwriting was rubbed with a friction member attached to the shaft tube, the handwriting was discolored and became colorless. This state was maintained at room temperature.
Moreover, the pastel pink handwriting was formed on the black paper using the writing instrument.
The handwriting was pink at room temperature (25 ° C.), and when rubbed with a SEBS friction member attached to the shaft tube, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 3
Preparation of microcapsule pigment which changes color from colorless to colorless (i) 4,5,6,7-tetrachloro-3- [4- (dimethylamino) -2-methylphenyl] -3- (1-ethyl-) as component 2.0 parts of 2-methyl-1H-indol-3-yl) -1 (3H) -isobenzofuranone, 4,4 '-(2-ethylhexane-1,1-diyl) diphenol as component (b) 3.0 parts, 5.0 parts of 2,2-bis (4′-hydroxyphenyl) -hexafluoropropane, and (c) color memory consisting of 50.0 parts of 4-benzyloxyphenylethyl caprate as the component A microcapsule pigment suspension containing the reversible thermochromic composition was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 0.5 μm, the complete color erasing temperature is 55 ° C., the complete color development temperature is −40 ° C., and particles exceeding 1.5 μm are 2% by volume in the total microcapsule pigment, The color changes from blue to colorless.

Preparation of microcapsule pigment which changes color from white to colorless 2,2-bis (4′-hydroxyphenyl) hexafluoropropane 3.0 parts, 1,1-bis (4-hydroxyphenyl) decane 3.0 parts, capric acid A microcapsule pigment suspension containing a composition comprising 50.0 parts of stearyl was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 0.5 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −40 ° C., and the particles exceeding 1.5 μm are 2% by volume in the total microcapsule pigment. The color changes from white to colorless.

Preparation of ink composition for pastel reversible thermochromic writing instrument: 5.0 parts of the above microcapsule pigment (previously cooled to −40 ° C. or less to develop a blue color), microcapsule pigment that changes color from white to colorless (previously 20.0 parts cooled to -40 ° C. or less and colored white) 0.3 parts succinoglycan (shear thinning agent), 10 parts urea, 10 parts glycerin, phosphate ester surfactant 0.5 part, nonionic permeability imparting agent 0.6 part, modified silicone antifoaming agent 0.1 part, antifungal agent 0.1 part, triethanolamine 0.5 part, water 52.9 parts An ink composition for a pastel reversible thermochromic writing instrument was prepared.

Writing instrument production (see Fig. 6)
An ink containing tube 11 made of polypropylene resin was connected to a pen body 3 holding a 0.5 mm stainless steel ball at the tip through a resin holder 5.
The ink composition 8 is filled into the ink containing tube, then the ink backflow prevention body 12 (liquid stopper) is filled at the rear end of the ink, and the tail plug 13 is fitted to the rear part of the ink containing tube to form the refill 14. Obtained.
Further, the refill was incorporated into the shaft cylinder 4 (comprised of a front shaft cylinder and a rear shaft cylinder), and after the cap 6 was fitted, a deaeration process was performed by a centrifugal process to obtain a writing instrument 1 (ballpoint pen).
In addition, SEBS rubber is attached to the rear portion of the rear shaft cylinder as the friction member 7.

A pastel blue handwriting was formed on the paper surface using the writing instrument.
The handwriting had a pastel blue color at room temperature (25 ° C.). When the handwriting was rubbed using a friction member attached to the shaft tube, the handwriting was discolored and became colorless, and this state was maintained at room temperature.
In addition, pastel blue handwriting was formed on black paper using the writing instrument.
The handwriting was blue at room temperature (25 ° C.), and when rubbed with a SEBS friction member attached to the shaft tube, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 4
Preparation of microcapsule pigment which changes color from colorless to colorless (I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine as component 1.0 part of -5,1 '(3'H) -isobenzofuran] -3-one, and 4,4'-(2-ethylhexane-1,1-diyl) diphenol 3.0 as component (b) Part, 2,2-bis (4'-hydroxyphenyl) -hexafluoropropane 5.0 parts, (c) reversible thermal discoloration having color memory composed of 50.0 parts 4-benzyloxyphenylethyl caprate A microcapsule pigment suspension encapsulating the composition was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 0.45 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −40 ° C., and particles exceeding 1.5 μm are 1% by volume in the total microcapsule pigment, The color changes from pink to colorless.

Preparation of microcapsule pigment which changes color from white to colorless 2,2-bis (4′-hydroxyphenyl) hexafluoropropane 3.0 parts, 1,1-bis (4-hydroxyphenyl) decane 3.0 parts, capric acid A microcapsule pigment suspension containing a composition comprising 50.0 parts of stearyl was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 0.45 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −40 ° C., and particles exceeding 1.5 μm are 1% by volume in the total microcapsule pigment, The color changes from white to colorless.

Preparation of ink composition for pastel reversible thermochromic writing instrument 7.5 parts of the above microcapsule pigment (previously cooled to −20 ° C. or less to develop blue color), microcapsule pigment that changes color from white to colorless (previously 17.5 parts cooled to -22 ° C. or less and colored white) 0.3 parts succinoglycan (shear thinning agent), 10 parts urea, 10 parts glycerin, phosphate ester surfactant 0.5 part, nonionic permeability imparting agent 0.6 part, modified silicone antifoaming agent 0.1 part, antifungal agent 0.1 part, triethanolamine 0.5 part, water 52.9 parts An ink composition for a pastel reversible thermochromic writing instrument was prepared.

Writing instrument production (see Figure 7)
The ink composition 8 was filled in the polypropylene shaft cylinder 4 having the pen body 3 fixed to the tip, then the ink follower 12 was filled, and the tail plug 13 was fitted.
Furthermore, after fitting the cap 6 containing the rubber seal 15, a deaeration process was performed by a centrifugal process to obtain a writing instrument 1 (ballpoint pen).
The pen body includes a stainless steel ball having a diameter of 0.7 mm held by a ball holding portion formed by cutting a metal material with a drill, and the ball is biased forward by a spring body. The cap is formed by attaching SEBS rubber as the friction member 7 at the tip.

A pastel pink character (handwriting) was formed by writing on the paper using the writing instrument.
The handwriting had a pastel pink color at room temperature (25 ° C.). When the handwriting was rubbed with a friction member attached to the cap, the handwriting was discolored and became colorless, and this state was maintained at room temperature.
Moreover, the pastel pink handwriting was formed on the black paper using the writing instrument.
The handwriting was pink at room temperature (25 ° C.), and when rubbed with a SEBS friction member attached to the shaft tube, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 5
Preparation of microcapsule pigment which changes color from colorless to colorless (I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine as component 1.0 part of -5,1 '(3'H) -isobenzofuran] -3-one, and 4,4'-(2-ethylhexane-1,1-diyl) diphenol 3.0 as component (b) Part, 2,2-bis (4'-hydroxyphenyl) -hexafluoropropane 5.0 parts, (c) reversible thermal discoloration having color memory composed of 50.0 parts 4-benzyloxyphenylethyl caprate A microcapsule pigment suspension encapsulating the composition was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 0.65 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −40 ° C., and the particles exceeding 1.5 μm are 7% by volume in the total microcapsule pigment. The color changes from pink to colorless.

Preparation of microcapsule pigment which changes color from white to colorless 2,2-bis (4′-hydroxyphenyl) hexafluoropropane 3.0 parts, 1,1-bis (4-hydroxyphenyl) decane 3.0 parts, capric acid A microcapsule pigment suspension containing a composition comprising 50.0 parts of stearyl was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 0.65 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −40 ° C., and particles exceeding 1.5 μm are 7% by volume in the total microcapsule pigment. The color changes from white to colorless.

Preparation of ink composition for pastel reversible thermochromic writing instrument: 5.0 parts of microcapsule pigment that changes from colored to colorless (previously cooled to -40 ° C. or less to develop pink), white to colorless 20.0 parts of a microcapsule pigment that changes color (previously cooled to -40 ° C. or less to develop a white color), 0.5 parts of hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: Cellosize WP-09L] 12.0 parts of glycerin, 0.02 part of antifoaming agent, 1.5 parts of preservative, 0.1 part of 10% diluted phosphoric acid solution and 54.88 parts of water are mixed to prepare a pastel reversible thermochromic writing instrument. An ink composition was obtained.

Writing instrument production (see Fig. 8)
The ink composition 8 is directly accommodated in the shaft cylinder 4, has a comb groove-shaped ink adjustment member 16 in front of the shaft cylinder, and the marking pen tip 3 (chisel type) is connected via the connection member 5. The writing instrument 1 (marking pen) was obtained by fitting.
The writing instrument is provided with a detachable cap, and SEBS resin is provided as a friction member 7 at the rear end of the shaft tube.

Pastel pink handwriting was formed on the paper surface using the writing instrument.
The handwriting had a pastel pink color at room temperature (25 ° C.). When the handwriting was rubbed with a friction member attached to the shaft tube, the handwriting was discolored and became colorless. This state was maintained at room temperature.
Moreover, the pastel pink handwriting was formed on the black paper using the writing instrument.
The handwriting was pink at room temperature (25 ° C.), and when rubbed with a SEBS friction member attached to the shaft tube, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 6
Preparation of microcapsule pigment which changes color from colorless to colorless (i) 4,5,6,7-tetrachloro-3- [4- (dimethylamino) -2-methylphenyl] -3- (1-ethyl-) as component 2.0 parts of 2-methyl-1H-indol-3-yl) -1 (3H) -isobenzofuranone, 4,4 '-(2-ethylhexane-1,1-diyl) diphenol as component (b) 3.0 parts, 5.0 parts of 2,2-bis (4′-hydroxyphenyl) -hexafluoropropane, and (c) color memory consisting of 50.0 parts of 4-benzyloxyphenylethyl caprate as the component A microcapsule pigment suspension containing the reversible thermochromic composition was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle size of the microcapsule pigment is 0.7 μm, the complete color erasing temperature is 55 ° C., the complete color development temperature is −40 ° C., and particles exceeding 1.5 μm are 7% by volume in the total microcapsule pigment. Turns colorless.

Preparation of microcapsule pigment which changes color from white to colorless 2,2-bis (4′-hydroxyphenyl) hexafluoropropane 3.0 parts, 1,1-bis (4-hydroxyphenyl) decane 3.0 parts, capric acid A microcapsule pigment suspension containing a composition comprising 50.0 parts of stearyl was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle size of the microcapsule pigment is 0.7 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −40 ° C., particles exceeding 1.5 μm are 7% by volume in the total microcapsule pigment, and the white color changes with temperature. Turns colorless.

Preparation of ink composition for pastel reversible thermochromic writing instrument Microcapsule pigment that changes from colored to colorless (previously cooled to -40 ° C or less to develop orange), 5.0 parts from white to colorless 25.0 parts of a microcapsule pigment (previously cooled to -40 ° C. or less and colored in white), hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cello size WP-09L], 0.5 parts, Pastel tone reversible thermochromic writing instrument ink by mixing 18.0 parts glycerin, 0.02 part defoaming agent, 1.5 parts preservative, 0.1 part 10% diluted phosphoric acid solution and 49.88 parts water. A composition was obtained.

Writing instrument production (see Fig. 9)
The ink composition 2 is impregnated with a polyester sliver covered with a synthetic resin film, impregnated with the ink composition, accommodated in a shaft cylinder 4 made of polypropylene resin, and made of polyester fiber at the tip of the shaft cylinder via a connecting member 5. The marking pen tip 3 (chisel type) was assembled in the connected state, and the cap 6 was attached to obtain the writing instrument 1 (marking pen).
The cap is an elastomer made of a polyester resin and serves also as a friction member.

A pastel blue handwriting was formed on the paper surface using the writing instrument.
The handwriting had a pastel blue color at room temperature (25 ° C.). When the handwriting was rubbed on the top of the cap, the handwriting was discolored and became colorless, and this state was maintained at room temperature.
In addition, pastel blue handwriting was formed on black paper using the writing instrument.
The handwriting was blue at room temperature (25 ° C.), and when it was rubbed at the top of the cap, the characters were decolored and no cloudy afterimage was visually recognized at the writing location.

Example 7
Preparation of microcapsule pigment which changes color from colorless to colorless (i) 4,5,6,7-tetrachloro-3- [4- (dimethylamino) -2-methylphenyl] -3- (1-ethyl-) as component 2.0 parts of 2-methyl-1H-indol-3-yl) -1 (3H) -isobenzofuranone, 4,4 '-(2-ethylhexane-1,1-diyl) diphenol as component (b) 3.0 parts, 5.0 parts of 2,2-bis (4′-hydroxyphenyl) -hexafluoropropane, and (c) color memory consisting of 50.0 parts of 4-benzyloxyphenylethyl caprate as the component A microcapsule pigment suspension containing the reversible thermochromic composition was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 1.0 μm, the complete color erasing temperature is 55 ° C., the complete color development temperature is −30 ° C., and the particles exceeding 1.5 μm are 20% by volume in the total microcapsule pigment. The color changes from blue to colorless.

Preparation of microcapsule pigment which changes color from white to colorless 2,2-bis (4′-hydroxyphenyl) hexafluoropropane 3.0 parts, 1,1-bis (4-hydroxyphenyl) decane 3.0 parts, capric acid A microcapsule pigment suspension containing a composition comprising 50.0 parts of stearyl was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 1.0 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −30 ° C., and the particles exceeding 1.5 μm are 20% by volume in the total microcapsule pigment. The color changes from white to colorless.

Preparation of ink composition for pastel reversible thermochromic writing instrument Microcapsule pigment that changes from colored to colorless (previously cooled to -30 ° C or less to develop blue) 5.0 parts, color changed from white to colorless 20.0 parts of microcapsule pigment (previously cooled to -30 ° C. or less to develop a white color), 0.3 part of succinoglycan (shear thinning agent), sugar mixture [Sanwa Starch Co., Ltd. ), Trade name: Sandeck 70] 3.0 parts, 0.5 parts of phosphate ester surfactant, 0.1 part of antifungal agent, 1.0 part of triethanolamine, and 70.1 parts of water were mixed. Thus, an ink composition for a pastel reversible thermochromic writing instrument was obtained.

Writing instrument production (see Fig. 10)
A ball holding portion formed by sucking and filling the ink composition 8 into the ink containing tube 11 made of polypropylene resin, and pressing and deforming the vicinity of the tip of the metal pipe inward from the outer surface via the resin connection member 5 And a ballpoint pen tip 3 holding a stainless steel ball having a diameter of 0.5 mm.
Next, an ink backflow preventer (liquid stopper) was filled from the rear end of the polypropylene pipe, and a tail plug was fitted to the rear part of the pipe to obtain a ballpoint refill.
The ball-point pen refill was incorporated into the shaft cylinder 4 to obtain a retractable writing instrument 1 (ballpoint pen).
The writing instrument is housed in the shaft cylinder in a state where the tip provided on the ballpoint pen refill is exposed to the outside air, and the shaft is formed by the operation of a clip-shaped protrusion / displacement mechanism (slide mechanism) provided on the side surface of the shaft cylinder. In this structure, the tip protrudes from the opening at the front end of the cylinder.
A friction member 7 made of SEBS resin is provided at the rear end portion of the shaft cylinder.

A pastel blue handwriting was formed on the paper surface using the writing instrument.
The handwriting had a pastel blue color at room temperature (25 ° C.). When the handwriting was rubbed using a friction member attached to the shaft tube, the handwriting was discolored and became colorless, and this state was maintained at room temperature.
In addition, pastel blue handwriting was formed on black paper using the writing instrument.
The handwriting was blue at room temperature (25 ° C.), and when rubbed with a SEBS friction member attached to the shaft tube, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 8
Preparation of microcapsule pigment which changes color from colorless to colorless (I) 2- (dibutylamino) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2,3-g] pyrimidine as component 1.0 part of -5,1 '(3'H) -isobenzofuran] -3-one, and 4,4'-(2-ethylhexane-1,1-diyl) diphenol 3.0 as component (b) Part, 2,2-bis (4'-hydroxyphenyl) -hexafluoropropane 5.0 parts, (c) reversible thermal discoloration having color memory composed of 50.0 parts 4-benzyloxyphenylethyl caprate A microcapsule pigment suspension encapsulating the composition was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 0.5 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −40 ° C., and the particles exceeding 1.5 μm are 1% by volume in the total microcapsule pigment. The color changes from pink to colorless.

Preparation of microcapsule pigment which changes color from white to colorless 2,2-bis (4′-hydroxyphenyl) hexafluoropropane 3.0 parts, 1,1-bis (4-hydroxyphenyl) decane 3.0 parts, capric acid A microcapsule pigment suspension containing a composition comprising 50.0 parts of stearyl was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 0.5 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −40 ° C., and the particles exceeding 1.5 μm are 1% by volume in the total microcapsule pigment. The color changes from white to colorless.

Preparation of ink composition for pastel reversible thermochromic writing instrument Microcapsule pigment that changes from colored to colorless (previously cooled to -40 ° C or less to develop blue) 5.0 parts, discolored from white to colorless 20.0 parts of microcapsule pigment (previously cooled to −40 ° C. or less and colored white), 0.3 part of succinoglycan (shear thinning agent), sugar mixture [Sanwa Starch Co., Ltd. ), Trade name: Sandeck 70] 3.0 parts, 0.5 parts of phosphate ester surfactant, 0.1 part of antifungal agent, 1.0 part of triethanolamine, and 70.1 parts of water were mixed. Thus, an ink composition for a pastel reversible thermochromic writing instrument was obtained.

Writing instrument production (see Fig. 11)
A ball holding portion formed by sucking and filling the ink composition 8 into the ink containing tube 11 made of polypropylene resin, and pressing and deforming the vicinity of the tip of the metal pipe inward from the outer surface via the resin connection member 5 And a ballpoint pen tip 3 holding a stainless steel ball having a diameter of 0.5 mm.
Next, an ink backflow preventer (liquid stopper) was filled from the rear end of the polypropylene pipe, and a tail plug was fitted to the rear part of the pipe to obtain a ballpoint refill.
The ball-point pen refill was incorporated into the shaft cylinder 4 to obtain a retractable writing instrument 1 (ballpoint pen).
The writing instrument is housed in the shaft cylinder with the tip provided on the ballpoint pen refill exposed to the outside air, and the front end opening of the shaft cylinder is activated by the operation of a retracting mechanism (knock mechanism) provided at the rear of the shaft cylinder. The chip protrudes from the part.
The intruding mechanism is provided with a friction member 7 made of SEBS resin.

Pastel pink handwriting was formed on the paper surface using the writing instrument.
The handwriting had a pastel pink color at room temperature (25 ° C.). When the handwriting was rubbed with a friction member attached to the shaft tube, the handwriting was discolored and became colorless. This state was maintained at room temperature.
Moreover, the pastel pink handwriting was formed on the black paper using the writing instrument.
The handwriting was pink at room temperature (25 ° C.), and when rubbed with a SEBS friction member attached to the shaft tube, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 9
Preparation of microcapsule pigment which changes color from colorless to colorless (i) 4,5,6,7-tetrachloro-3- [4- (dimethylamino) -2-methylphenyl] -3- (1-ethyl-) as component 2.0 parts of 2-methyl-1H-indol-3-yl) -1 (3H) -isobenzofuranone, 4,4 '-(2-ethylhexane-1,1-diyl) diphenol as component (b) 3.0 parts, 5.0 parts of 2,2-bis (4′-hydroxyphenyl) -hexafluoropropane, and (c) color memory consisting of 50.0 parts of 4-benzyloxyphenylethyl caprate as the component A microcapsule pigment suspension containing the reversible thermochromic composition was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 0.7 μm, the complete color erasing temperature is 55 ° C., the complete color development temperature is −40 ° C., and the particles exceeding 1.5 μm are 5% by volume in all the microcapsule pigments. Turns colorless.

Preparation of microcapsule pigment which changes color from white to colorless 2,2-bis (4′-hydroxyphenyl) hexafluoropropane 3.0 parts, 1,1-bis (4-hydroxyphenyl) decane 3.0 parts, capric acid A microcapsule pigment suspension containing a composition comprising 50.0 parts of stearyl was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle size of the microcapsule pigment is 0.7 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −40 ° C., and particles exceeding 1.5 μm are 5% by volume in the total microcapsule pigment. Turns colorless.

Preparation of ink composition for pastel reversible thermochromic writing instrument Microcapsule pigment that changes from colored to colorless (previously cooled to -40 ° C or less to develop orange), 5.0 parts from white to colorless 25.0 parts of a microcapsule pigment (previously cooled to -40 ° C. or less and colored in white), hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cello size WP-09L], 0.5 parts, Pastel tone reversible thermochromic writing instrument ink by mixing 18.0 parts glycerin, 0.02 part defoaming agent, 1.5 parts preservative, 0.1 part 10% diluted phosphoric acid solution and 49.88 parts water. A composition was obtained.

Preparation of writing instrument The ink composition covered with a synthetic resin film on a polyester sliver is impregnated with the ink composition, accommodated in a shaft tube made of polypropylene resin, and a marking made of polyester fiber at the tip of the shaft tube through a connecting member The pen tip 3 (bullet type) was assembled in a connected state, and a cap was attached to obtain a writing instrument (marking pen).

Preparation of writing instrument set The writing instrument set was obtained by combining the writing instrument and a rectangular SEBS resin friction body.
A pastel blue character (handwriting) was formed by writing on the paper using the writing instrument.
The handwriting had a pastel blue color at room temperature (25 ° C.). When the character was rubbed with a friction body, the character was decolored and colorless, and this state was maintained at room temperature.
In addition, pastel blue handwriting was formed on black paper using the writing instrument.
The handwriting was blue at room temperature (25 ° C.), and when rubbed with a SEBS friction member attached to the shaft tube, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Comparative Example 1
Preparation of microcapsule pigment which changes color from colorless to colorless (i) 4,5,6,7-tetrachloro-3- [4- (dimethylamino) -2-methylphenyl] -3- (1-ethyl-) as component 2.0 parts of 2-methyl-1H-indol-3-yl) -1 (3H) -isobenzofuranone, 4,4 '-(2-ethylhexane-1,1-diyl) diphenol as component (b) 3.0 parts, 5.0 parts of 2,2-bis (4′-hydroxyphenyl) -hexafluoropropane, and (c) color memory consisting of 50.0 parts of 4-benzyloxyphenylethyl caprate as the component A microcapsule pigment suspension containing the reversible thermochromic composition was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 2.3 μm, the complete color erasing temperature is 55 ° C., the complete color development temperature is −20 ° C., and particles exceeding 1.5 μm are 80% by volume in the total microcapsule pigment. The color changes from blue to colorless.

Preparation of microcapsule pigment which changes color from white to colorless 2,2-bis (4′-hydroxyphenyl) hexafluoropropane 3.0 parts, 1,1-bis (4-hydroxyphenyl) decane 3.0 parts, capric acid A microcapsule pigment suspension containing a composition comprising 50.0 parts of stearyl was obtained.
The suspension was centrifuged to isolate the microcapsule pigment.
The average particle diameter of the microcapsule pigment is 2.3 μm, the complete color erasing temperature is 58 ° C., the complete color development temperature is −20 ° C., and particles exceeding 1.5 μm are 80% by volume in the total microcapsule pigment, The color changes from white to colorless.

Preparation of ink composition for pastel reversible thermochromic writing instrument Microcapsule pigment that changes from colored to colorless (previously cooled to -20 ° C or less to develop blue) 3.0 parts, color changed from white to colorless 22.0 parts of microcapsule pigment (previously cooled to -20 ° C. or less and colored in white), 0.5 part of hydroxyethyl cellulose, comb-type polymer dispersant [made by Nippon Lubrizol Co., Ltd., trade name : Solsperse 43000], 0.2 parts, organic nitrogen sulfur compound [made by Hokuko Chemical Co., Ltd., trade name: Hokuside R-150, 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl- 4-isothiazolin-3-one mixture] 1.0 parts, polyvinyl alcohol 0.5 parts, glycerin 25.0 parts, antifoaming agent 0.02 parts, water 47.78 parts mixed and passed. A tell-tone reversible thermochromic ink composition for writing instruments was obtained.

Preparation of a writing instrument A marking pen made of polyester fiber is impregnated with an ink occlusion body in which a polyester sliver is coated with a synthetic resin film, impregnated with the ink composition, accommodated in a shaft tube made of polypropylene resin, and a polyester fiber at the tip of the shaft tube through a holder. The body (cannonball type) was assembled in a connected state, and a cap was attached to obtain a writing instrument (marking pen).
A SEBS resin is mounted as a friction member on the rear end of the shaft tube.

Pastel blue handwriting was formed on white paper using the writing instrument.
The handwriting had a pastel blue color at room temperature (25 ° C.). When the handwriting was rubbed using a friction member attached to the shaft tube, the handwriting was discolored and became colorless, and this state was maintained at room temperature.
In addition, pastel blue handwriting was formed on black paper using the writing instrument.
The handwriting was blue at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft tube, the characters disappeared, but a cloudy afterimage was visually recognized at the writing location.

t ₁ Complete color development temperature of reversible thermochromic microcapsule pigment with heat decoloring type t ₂ Color development start temperature of reversible thermochromic microcapsule pigment with heat decoloration type t ₃ Reversible thermochromic microcapsule pigment with heat decoloration type Decoloration start temperature of t ₄ Complete decolorization temperature of reversible thermochromic microcapsule pigment of heat decoloring type T ₁ Complete decoloration temperature of reversible thermochromic microcapsule pigment of ₁ heating color developing type T ₂ Reversible heat of color developing type of heat decoloring type Discoloration start temperature of the color-changing microcapsule pigment T ₃ Color development start temperature of the reversible thermochromic microcapsule pigment of the ₃ heating color development type T ₄ Color development temperature of the reversible thermochromic microcapsule pigment of the heat development color type ΔH Hysteresis width 1 Writing instrument 2 Ink occlusion body 3 Pen body 4 Shaft cylinder 5 Holder 6 Cap 7 Friction member 8 Ink composition 9 Stirring body 10 Valve mechanism 11 Ink storage tube 12 Ink reverse Current prevention body 13 Tail plug 14 Refill 15 Rubber seal 16 Ink adjustment member

Claims (11)

  Encapsulating a reversible thermochromic composition comprising water and (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color reaction occurs. Selected from microcapsule pigments having an average particle diameter of 0.01 to 1.0 μm that changes from colored to colorless, and crystalline esters, ethers, and ketones having a melting point in the range of −40 ° C. to + 95 ° C. A microcapsule pigment having an average particle diameter of 0.01 to 1.0 μm which changes from white to colorless, in which the compound is encapsulated, and from white to colorless An ink composition for a pastel reversible thermochromic writing instrument, wherein the weight ratio of the microcapsule pigment that changes color is 1: 1 to 1:25.   The microcapsule pigment that changes from colored to colorless has particles of 1.5 μm or more in 30% by volume or less of the total microcapsule pigment, and the microcapsule pigment that changes from white to colorless has particles of 1.5 μm or more. The ink composition for a reversible thermochromic writing instrument according to claim 1, wherein is not more than 30% by volume in the total microcapsule pigment.   The average particle diameter of the microcapsule pigment that changes from colored to colorless is in the range of 0.1 to 0.65 μm, and the average particle diameter of the microcapsule pigment that changes from white to colorless is from 0.1 to 0.65 μm. The ink composition for reversible thermochromic writing instruments according to claim 1 or 2, which is in the range of   The ink composition for pastel reversible thermochromic writing instruments according to any one of claims 1 to 3, comprising a polymer flocculant.   The ink composition for a pastel reversible thermochromic writing instrument according to claim 4, comprising a comb-type polymer dispersant having a carboxyl group in a side chain, an organic nitrogen sulfur compound, and a water-soluble resin.   The description as described in any one of Claims 1 thru | or 3 containing the water-soluble organic solvent, the comb-type polymer dispersing agent which has a carboxyl group in a side chain, an organic nitrogen sulfur compound, and water-soluble resin. Pastel reversible thermochromic ink composition for writing instruments.   The organic nitrogen sulfur compound is 2- (4-thiazoyl) -benzimidazole, 2- (thiocyanatomethylthio) -1,3-benzothiazole, 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl The ink composition for a pastel tone reversible thermochromic writing instrument according to claim 5 or 6, which is a compound selected from -4-isothiazolin-3-one.   The ink composition for a pastel reversible thermochromic writing instrument according to any one of claims 1 to 3, comprising a shear thinning agent.   A writing instrument containing the ink composition for a pastel tone reversible thermochromic writing instrument according to any one of claims 1 to 8.   The writing instrument according to claim 9, comprising a friction member.   A writing instrument set comprising the writing instrument according to claim 9 and a friction body.

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