JP2005213361A - Ink composition for thermochromic color-memory writing utensil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an ink composition for writing utensils, effectively developing properties in which wide hysteresis width (▵H) is exhibited with respect to a color intensity-temperature curve, a reversible change in color of coloring and decoloring is caused, both a color of a lower-temperature side than a temperature of change in color and a color of a higher-temperature side are alternately stored and kept, any color is reversibly reproduced and stored and kept by application of heat or cold, if necessary. <P>SOLUTION: The ink composition for a thermochromic color-memory writing utensils comprises microcapsule pigment containing a thermochromic color-memory composition composed of a homogeneous solubilized mixture of (a) an electron donative coloring organic compound, (b) an electron-accepting compound and (c) an ester compound represented by general formula (1) (R is a ≥4C alkyl group or alkenyl group) as a reaction medium for controlling color reactions of the aforementioned (a) and (b). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink composition for a temperature-sensitive color-changing color memory writing instrument. In more detail, it exhibits a reversible discoloration of color development and decoloration by exhibiting a large hysteresis characteristic due to temperature change, and even after the application of heat or cold heat required for discoloration is removed, either the colored state or the decolored state The present invention relates to an ink composition for a temperature-sensitive color-changing color memory writing instrument having a color-changing function that holds the color reversibly and reversibly.

Conventionally, (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound (c) a compound that is a reaction medium that reversibly causes the electron-donating reaction by (a) and (b) above. An ink composition for a writing instrument in which a temperature-sensitive color-changing color memory composition is dispersed in a solvent is disclosed (for example, see Patent Document 1).
The ink composition changes color before and after the color change temperature, and there is only one specific state in the normal temperature range of both states before and after the color change, and the other state is required for the state to be manifested. Compared with the type that is maintained while heat or cold is applied and returns to the normal state when heat or cold is not applied, either the color at the lower temperature side or the color at the higher temperature side than the discoloration temperature. Controls the color reaction contained in the temperature-sensitive color-changing color memory composition by being able to hold it selectively in the normal temperature range and can be held interchangeably by applying heat or cold as needed. Only a system in which a specific compound is applied as a constituent as a reaction medium is expressed.
JP-A-7-186588

  The inventor further examined the ink composition for a reversible thermochromic writing instrument, and (i) an electron-donating color-forming organic compound, (b) an electron-accepting compound, (c) the (i), (B) Reaction medium in an ink composition for a writing instrument comprising a microcapsule pigment encapsulating a temperature-sensitive color-changing color memory composition comprising a homogeneous solution of a reaction medium for controlling the color reaction of (b) and a solvent. It is intended to further increase the degree of freedom of selection.

（式中、Ｒは炭素数４以上のアルキル基又はアルケニル基を示す。）
更には、前記（ロ）電子受容性化合物が少なくとも３以上のベンゼン環を有し、且つ、分子量が２５０以上のフェノール性水酸基を有する化合物、又は、一般式（２）で示されるフェノール性水酸基を有する化合物であること、

（式中、Ｒは炭素数１乃至８のアルキル基を示す。）
更には、前記マイクロカプセル顔料は、色濃度−温度曲線に関して４０℃乃至７０℃のヒステリシス幅（ΔＨ）を示して変色すること、前記マイクロカプセル顔料は、色濃度−温度曲線に関して、完全消色温度（Ｔ₄ ）が４０℃以上であり、且つ、最低保持温度（Ｔ₂ ）が２０℃以下である、常温域で色彩記憶性を有すること等を要件とする。 The present inventor is a system in which an ester compound composed of an alcohol compound having two aromatic rings in a molecule and a saturated or unsaturated fatty acid having 4 or more carbon atoms is applied as a reaction medium for the color reaction, The present inventors have found that a thermochromic property having a large hysteresis width (ΔH) is exhibited and an effective color memory effect is exhibited, and the present invention has been completed.
That is, the present invention provides (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling the color reaction of (a) and (b) described below. Requirements for ink composition for temperature-sensitive color-change color memory writing instrument comprising a microcapsule pigment containing a temperature-sensitive color-change color memory composition comprising a homogeneous solution of an ester compound represented by formula (1) and a solvent. And

(In the formula, R represents an alkyl group or alkenyl group having 4 or more carbon atoms.)
Furthermore, the (b) electron-accepting compound has at least 3 or more benzene rings and a compound having a phenolic hydroxyl group having a molecular weight of 250 or more, or a phenolic hydroxyl group represented by the general formula (2). Having a compound,

(In the formula, R represents an alkyl group having 1 to 8 carbon atoms.)
Furthermore, the microcapsule pigment changes color with a hysteresis width (ΔH) of 40 ° C. to 70 ° C. with respect to the color density-temperature curve, and the microcapsule pigment has a complete decoloring temperature with respect to the color density-temperature curve. It is required that (T ₄ ) is 40 ° C. or higher and that the minimum holding temperature (T ₂ ) is 20 ° C. or lower and has color memory in a normal temperature range.

  The present invention relates to an ester composed of an alcohol compound having two aromatic rings in the molecule and a saturated or unsaturated fatty acid having 4 or more carbon atoms as the component (c) in the thermochromic color-memory composition. By using a compound, a wide hysteresis width (ΔH) is exhibited with respect to the color density-temperature curve, causing reversible discoloration of color development and decoloration, and both the color on the low temperature side and the color on the high temperature side are changed alternately. Since it is possible to effectively express the characteristics that can be stored and retained by reversibly reproducing any color by applying heat or cold as necessary, conventional ester compounds can be used. It is possible to provide an ink composition for writing instruments that is more practical than a blended system.

The hysteresis characteristics in the color density-temperature curve of the temperature-sensitive color-changing color memory composition used in the present invention will be described below with reference to the graph of FIG.
In FIG. 1, the vertical axis represents color density and the horizontal axis represents temperature. The change in color density due to the temperature change proceeds along the arrow. Here, A is a point indicating the density at the minimum temperature T ₄ (hereinafter referred to as the complete color erasing temperature) reaching the complete color erasing state, and B is the maximum temperature T ₃ (hereinafter referred to as color development holding) at which the complete color development state can be maintained. C is a point indicating the density at the minimum temperature T ₂ (hereinafter referred to as the minimum holding temperature) at which the completely decolored state can be maintained, and D is the maximum at which the fully colored state is reached. This is a point indicating the density at the temperature T ₁ (hereinafter referred to as the complete color development temperature).
The discoloration temperature region is the temperature region between T ₁ and T ₄ , and both the colored state and the decolored state can coexist, and the temperature region between T ₂ and T _3, which is the region where the difference in color density is large, is substantial. Discoloration temperature range (two-phase holding temperature range).
The length of the line segment EF is a scale indicating the discoloration contrast, and the length of the line segment HG is a temperature width indicating the degree of hysteresis (hereinafter referred to as hysteresis width ΔH). It is easy to maintain each state before and after the color change.
In the experiments of the present inventors, the ΔH value that can be maintained in each state before and after the color change is in the range of 40 ° C. to 70 ° C., preferably 50 to 70 ° C., more preferably 60 to 70 ° C.
In the above, the two phases of the colored state and the decolored state are substantially maintained, and the temperature which is practically used, that is, the temperature range between T ₃ and T ₂ including T _A is 20 ° C. or more and 60 ° C. A range of less than is valid.
Further, in order to allow only one specific state to exist in the room temperature range before and after the discoloration, the complete decoloring temperature (T ₄ ) is 40 ° C. or higher, preferably 50 ° C. or higher, and the minimum holding temperature. (T ₂ ) is 20 ° C. or lower, preferably 10 ° C. or lower.
Here, Δt, which is the difference between T ₄ and T ₃ , or the difference between T ₂ and T ₁ , is a scale indicating the sensitivity of discoloration.

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

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

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-dihydroxydiphenyl sulfone, 1,1-bis (4′-hydroxyphenyl) Ethane, 2,2-bis (4'-hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, 1-phenyl-1,1-bis (4'-hydroxyphenyl) ethane, 1,1 -Bis (4'-hydroxyphenyl) -3 Methylbutane, 1,1-bis (4'-hydroxyphenyl) -2-methylpropane, 1,1-bis (4'-hydroxyphenyl) n-hexane, 1,1-bis (4'-hydroxyphenyl) n- Heptane, 1,1-bis (4′-hydroxyphenyl) n-octane, 1,1-bis (4′-hydroxyphenyl) n-nonane, 1,1-bis (4′-hydroxyphenyl) n-decane, 1,1-bis (4′-hydroxyphenyl) n-dodecane, 2,2-bis (4′-hydroxyphenyl) butane, 2,2-bis (4′-hydroxyphenyl) ethyl propionate, 2,2 -Bis (4'-hydroxyphenyl) -4-methylpentane, 2,2-bis (4'-hydroxyphenyl) hexafluoropropane, 2,2-bis (4'-hydroxyphenyl) Sulfonyl) n- heptane, there is 2,2-bis (4'-hydroxyphenyl) n- nonane.
As the compound having a phenolic hydroxyl group, a compound having a phenolic hydroxyl group having at least 3 benzene rings and having a molecular weight of 250 or more, preferably a molecular weight of 250 to 500, or the general formula (2) When the compound having a phenolic hydroxyl group represented by is used, it is possible to make the color change sensitivity when shifting from the decolored state to the colored state more sensitive. Specifically, as shown in FIG. 2, the discoloration behavior at the time of reaching the temperature (T ₁ ) indicating the complete color development temperature from the temperature (T ₄ ) indicating the completely decolored state through the temperature (T ₂ ) for starting the color development. in the temperature to start the color development (T ₂₎ showed no behavior that develops color gradually shifted to the high temperature side, the temperature indicating the complete coloring temperature and the temperature (T ₂₎ to start the color development as in FIG. 1 (T The temperature difference of ₁ ) is small, and it becomes easy to show a behavior that shifts sharply from the decolored state to the colored state.
As the compound having at least 3 or more benzene rings and having a phenolic hydroxyl group having a molecular weight of 250 or more,
4,4 ', 4 "-methylidenetrisphenol,
2,6-bis [(2-hydroxy-5-methylphenol) methyl] -4-methylphenol,
4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol,
4,4 ', 4 "-ethylidene tris [2-methylphenol],
4,4 ′-[(2-hydroxyphenyl) methylene] bis [2,3,6-triphenylphenol],
2,2-methylenebis [6-[(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol],
2,4,6-tris (4-hydroxyphenylmethyl) 1,3-benzenediol,
4,4 ', 4 "-ethylidenetrisphenol,
4,4 ′-[(4-hydroxyphenyl) methylene] bis [2-methylphenol],
4,4 ′-[(4-hydroxyphenyl) methylene] bis [2,6-dimethylphenol],
4,4 ′-[(4-hydroxyphenyl) methylene] bis [2-methylphenol],
4,4 ′-[(4-hydroxyphenyl] methylene] bis [2,6-dimethylphenol],
4,4 ′-[(4-hydroxy-3-methoxyphenyl) methylene] bis [2,6-dimethylphenol],
2,4-bis [(5-methyl-2-hydroxyphenyl) methyl] -6-cyclohexylphenol,
4,4 ′-[1- [4- [1- (4-hydroxy-3-methylphenol) -1-methylethyl] phenyl] ethylidene] bis [2-methylphenol],
4,4 ′-[(4-hydroxyphenyl) methylene] bis [2-cyclohexyl-5-methylphenol],
4,6-bis [(4-hydroxyphenyl) methyl] 1,3-benzenediol,
4,4 ′-[(3,4-di-hydroxyphenyl) methylene] bis [2,6-dimethylphenol],
4,4 ′-(1-phenylethylidene) bisphenol,
5,5 ′-(1-methylethylidene) bis [1-phenyl-2-ol],
4,4 ', 4 "-methylidenetrisphenol,
4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol,
4,4 ′-(phenylmethylene) bisphenol,
4,4 ′-[1,4-phenylenebis (1-methylethylidene)] bis [2-methylphenol],
5,5 ′-(1,1-cyclohexylidene) bis- [1-biphenyl-2-ol] and the like.
As the compound having a phenolic hydroxyl group represented by the general formula (2),
Bis (3-methyl-4-hydroxyphenyl) sulfide, bis (3,5-dimethyl-4-hydroxyphenyl), bis (3-ethyl-4-hydroxyphenyl) sulfide, bis (3,5-diethyl-4-) Hydroxyphenyl) sulfide, bis (3-propyl-4-hydroxyphenyl) sulfide, bis (3,5-dipropyl-4-hydroxyphenyl) sulfide, bis (3-t-butyl-4-hydroxyphenyl) sulfide, bis ( 3,5-t-butyl-4-hydroxyphenyl) sulfide, bis (3-pentyl-4-hydroxyphenyl) sulfide, bis (3-hexyl-4-hydroxyphenyl) sulfide, bis (3-heptyl-4-hydride) Xylphenyl) sulfide, bis (5-octyl-2-hydroxyphenyl) Rufido, and the like.
The compound having a phenolic hydroxyl group can develop the most effective thermochromic property, but aromatic carboxylic acids and aliphatic carboxylic acids having 2 to 5 carbon atoms, carboxylic acid metal salts, acidic phosphate esters and their It may be a compound selected from metal salts, 1,2,3-triazole and derivatives thereof.

Next, the ester compound of component (c) will be specifically exemplified.
The ester compound used in the present invention is an ester compound composed of an alcohol compound having two aromatic rings in the molecule and a saturated or unsaturated fatty acid having 4 or more carbon atoms.
R in the formula represents an alkyl group or alkenyl group having 4 or more carbon atoms, preferably an alkyl group having 6 to 20 carbon atoms, more preferably an alkyl group having 8 to 18 carbon atoms.
Specific examples of the compound include butanoic acid-4-benzyloxyphenylethyl, pentanoic acid-4-benzyloxyphenylethyl, hexanoic acid-4-benzyloxyphenylethyl, heptanoic acid-4-benzyloxyphenylethyl, and octanoic acid. -4-benzyloxyphenylethyl, nonanoic acid-4-benzyloxyphenylethyl, decanoic acid-4-benzyloxyphenylethyl, undecanoic acid-4-benzyloxyphenylethyl, dodecanoic acid-4-benzyloxyphenylethyl, tridecanoic acid -4-benzyloxyphenylethyl, tetradecanoic acid-4-benzyloxyphenylethyl, pentadecanoic acid-4-benzyloxyphenylethyl, hexadecanoic acid-4-benzyloxyphenylethyl, heptadecanoic acid-4-benzylo Cyphenylethyl, octadecanoic acid-4-benzyloxyphenylethyl, nonadecanoic acid-4-benzyloxyphenylethyl, eicosanoic acid-4-benzyloxyphenylethyl, tricosanoic acid-4-benzyloxyphenylethyl, tetracosanoic acid-4-benzyl Oxyphenylethyl, pentacosanoic acid-4-benzyloxyphenylethyl, hexacosanoic acid-4-benzyloxyphenylethyl, heptacosanoic acid-4-benzyloxyphenylethyl, octacosanoic acid-4-benzyloxyphenylethyl, nonacosanoic acid-4-benzyl Examples thereof include oxyphenyl ethyl, triacontanoic acid-4-benzyloxyphenylethyl, and hentriacontanoic acid-4-benzyloxyphenylethyl.

  The ester compound has a wide hysteresis width equivalent to or higher than the case of using an ester compound used in a conventional temperature-sensitive color-changing color-memory liquid composition. Excellent applicability.

  As the component (c) of the present invention, the ester compound is used, and other esters, alcohols, carboxylic acids, ketones, amides, and the like can be added as long as the hysteresis characteristics do not greatly change. In this case, the addition amount is preferably 20 or less (parts by weight) with respect to the ester 100 of the present invention in order to effectively exhibit the desired color memory effect.

In the present invention, the proportions of the three components (A), (B), and (C) depend on the concentration, the color change temperature, the color change form, and the type of each component, but in general, components that provide desired characteristics. The ratio is in the range of (b) component 1 to (b) component 0.1 to 50, preferably 0.5 to 20, (c) component 1 to 800, preferably 5 to 200 (the ratio). Are all parts by weight).
Each component may be a mixture of two or more, and an antioxidant, an ultraviolet absorber, an infrared absorber, a dissolution aid, etc. can be added as long as the function is not hindered.

The three-component homogeneous compatible mixture 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 temperature-sensitive color-changing color memory composition can be maintained in the same composition and exhibit the same effects under various usage conditions.
The microcapsules satisfy practicality in the range of an average particle size of 0.5 to 20 μm, preferably 0.5 to 10 μm.
When the average value of the maximum outer diameter exceeds 20 μm, the microcapsule lacks dispersion stability for use in ink.
On the other hand, in a system having an average value of the maximum outer diameter of 0.5 μm or less, it is difficult to exhibit high density color development.
In addition, the range of inclusion / wall membrane = 7/1 to 1/1 (weight ratio) is effective for the microcapsule. When the ratio of inclusion is larger than the above range, the color density and sharpness at the time of color development. However, the inclusion / wall membrane = 6/1 to 1/1 (weight ratio) is preferable.
The microencapsulation includes conventionally known isocyanate-based interfacial polymerization methods, in-situ polymerization methods such as melamine-formalin, in-liquid curing coating methods, phase separation methods from aqueous solutions, phase separation methods from organic solvents, melting There are a dispersion cooling method, an air suspension coating method, a spray drying method, and the like, which are appropriately selected according to use. 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 temperature-sensitive color-changing color memory composition or the ink composition using the same is mixed with a general dye (non-thermochromic) to change from colored (1) to colored (2). It can also exhibit a discoloration behavior.

  In the present invention, the microcapsule pigment is dispersed in a solvent to obtain an ink composition.

As a solvent used for the ink, 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, and the like.

  Examples of resins include ketone resins, ketone-formaldehyde resins, amide resins, alkyd resins, rosin-modified resins, rosin-modified phenol resins, phenol resins, xylene resins, polyvinylpyrrolidone, α- and β-pinene / phenol polycondensation resins, and polyvinyl butyral. Resins, acrylic resins, styrene maleic acid copolymers, cellulose derivatives, polyvinyl pyrrolidone, polyvinyl alcohol, dextrin, and the like can be added, and are used for fixing to a writing material and imparting viscosity.

Further, if necessary, a shear thinning agent can be added.
By adding the shear thinning agent, it is possible to suppress bleeding of the handwriting, so that even if writing on a fiber material such as a highly penetrating cloth as well as paper, the handwriting does not bleed and a good handwriting is achieved. Can be formed.
Furthermore, when the writing instrument to be filled with the ink is in the form of a ballpoint pen, it prevents ink leakage from the gap between the ball and the tip when not in use, or the ink when the writing tip is left upward (upright state). Backflow can be prevented.
The viscosity of the ink composition to which the shear thinning agent is added is 20 to 300 mPa · s at a shear rate of 3.84 S ⁻¹ by an E-type rotational viscometer at 20 ° C., and It is preferable that the shear thinning index is 0.1 to 0.9.
The shear thinning index (n) is expressed by an empirical formula T = Kj ⁿ (K is a non-Newtonian viscosity coefficient) obtained from rheological measurement using a viscometer such as a shear stress value (T) and a shear rate value (j). It is a value calculated by fitting.

  Examples of the shear thinning agent include xanthan gum, welan gum, succinoglycan (average molecular weight of about 1 to 8 million) whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose, alka gum, guar gum, locust bean gum and A gel having a gelling ability extracted from seaweeds such as glucomannan, agar and carrageenan, polymers having a molecular weight of 100,000 to 150,000 mainly composed of derivatives thereof, hydroxyethyl cellulose, alginic acid alkyl esters, and alkyl esters of methacrylic acid. Viscous polysaccharides, benzylidene sorbitol and benzylidene xylitol or derivatives thereof, crosslinkable acrylic acid polymer, inorganic fine particles, polyglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester Nonionics having an HLB value of 8 to 12, such as polyoxyethylene castor oil, polyoxyethylene lanolin, lanolin alcohol, beeswax derivatives, polyoxyethylene alkyl ether / polyoxypropylene alkyl ether, polyoxyethylene alkyl phenyl ether, fatty acid amide, etc. Examples of the surfactant include salts of dialkyl or dialkenylsulfosuccinic acid, a mixture of N-alkyl-2-pyrrolidone and an anionic surfactant, and a mixture of polyvinyl alcohol and an acrylic resin.

  When the ink composition of the present invention is used by filling a ballpoint pen, a higher fatty acid such as oleic acid, a nonionic surfactant having a long chain alkyl group, a polyether-modified silicone oil, 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 add a lubricant such as a phosphoric acid diester or a metal salt, an ammonium salt, an amine salt, an alkanolamine salt thereof to give the ball seat an antiwear effect.

  In addition, 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 pyrophosphate sodium, defoamers, may be used a dispersing agent, a fluorine based surfactant to improve ink permeability and nonionic surfactants.

The ink composition is put into practical use by filling a marking pen or ballpoint pen with a tip attached to the writing tip.
When filling the marking pen, the structure and shape of the marking pen itself are not particularly limited. For example, a fiber tip, felt tip, plastic tip is attached to the writing tip, and the fiber bundle contained in the shaft cylinder is used. The ink occlusion body is impregnated with ink, the ink is supplied to the tip of the writing, the ink is directly stored inside the shaft cylinder, and the ink flow rate adjustment member consisting of a comb groove-like ink flow rate adjustment member or fiber bundle is interposed The marking pen of structure is mentioned.
When filling the ball-point pen, the structure and shape of the ball-point pen itself are not particularly limited. For example, an ink occlusion body composed of a fiber bundle housed in the shaft tube is impregnated with ink and supplied to the writing tip. Structure, ink is stored directly inside the shaft cylinder, and there is an ink storage tube filled with the ink composition in the shaft cylinder, with a comb groove-shaped ink flow control member and an ink flow control member consisting of fiber bundles interposed The ink storage tube communicates with a chip having a ball attached to the tip, and a ballpoint pen having a structure in which a liquid stopper for backflow prevention is in intimate contact with the end surface of the ink.

The ballpoint pen tip will be described in more detail. A tip formed by holding a ball in a ball holding portion obtained by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, or a metal material is cut by a drill or the like A chip formed by holding a ball in a ball holding part formed by the above, a chip provided with a resin ball receiving seat inside a metal or plastic chip, or a ball held by the chip forward by a spring body Energized items can be applied.
Moreover, the said ball | bowl can use the thing about 0.3-3 mm diameters, such as a cemented carbide alloy, stainless steel, a ruby, a ceramic, resin, rubber | gum.
In addition, the writing instrument filled with the ink of the present invention includes those provided with a rolling mechanism such as a roller at the tip of the writing for forming a handwriting by the same rolling operation as that of the ball.

For example, a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon is used as the ink storage tube that stores the ink composition.
Furthermore, by using a transparent, colored transparent, or translucent molded body as the ink containing tube, the ink color, the remaining amount of ink, and the like can be confirmed.
In addition to directly connecting the chip to the ink storage tube, the ink storage tube and the chip may be connected via a connecting member.
The ink storage tube may be a refill type in which the refill is accommodated in the shaft cylinder, or the shaft cylinder itself having a tip mounted on the tip is used as an ink container to directly fill the shaft cylinder with ink. May be.

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

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

Examples of the present invention are shown below, but the present invention is not limited thereto.
Example 1
Preparation of temperature-sensitive color-changing color-memory microcapsule pigment (i) 4.5 parts by weight of 2- (2-chloroanilino) -6-di-n-butylaminofluorane as component (1,) 1,1- Bis (4'-hydroxyphenyl) n-decane 4.5 parts by weight, 1,1-bis (4'-hydroxyphenyl) hexafluoropropane 7.5 parts by weight, (c) 4-benzyloxyphenyl laurate as component A temperature-sensitive color-changing color memory composition comprising 50.0 parts by weight of ethyl is uniformly heated and dissolved, and 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 40.0 parts by weight of a co-solvent are used as wall film materials. The mixed solution is emulsified and dispersed in 8% aqueous polyvinyl alcohol solution so as to form fine droplets. After stirring at 70 ° C. for about 1 hour, 2.5 parts by weight of a water-soluble aliphatic modified amine is added. Stirring was continued for 6 hours to obtain a temperature-sensitive color-change color-memory microcapsule pigment suspension.
The suspension was centrifuged to isolate a thermochromic color memory microcapsule pigment.
The microcapsule pigment changes its color from black to colorless due to temperature change.

Preparation of temperature-sensitive color-changing color memory ink 25.7 parts by weight of the microcapsule pigment, 0.2 parts by weight of succinoglycan (shear thinning agent), 5.5 parts by weight of urea, 7.5 parts by weight of glycerin, Nonionic permeability imparting agent [manufactured by San Nopco Co., Ltd., trade name: Nopco SW-WET-366] 0.03 parts by weight, modified silicone antifoaming agent [manufactured by Nippon Silicone Co., Ltd., trade name: FS Antifoam 013B] 0.15 parts by weight, preservative [Zeneca Co., Ltd., trade name: Proxel XL-2] 0.1 parts, lubricant [Daiichi Kogyo Seiyaku Co., Ltd. Prisurf A212C] 0.5 parts by weight A temperature-sensitive color-changing color memory ink comprising 0.5 parts by weight of triethanolamine and 59.82 parts by weight of water was prepared.

Preparation of writing instrument 0.97 g of the ink (previously cooled to −20 ° C. or lower and allowed to stand at room temperature after coloring the microcapsule pigment in black) was sucked and filled in 0.97 g of a polypropylene pipe having an inner diameter of 4.4 mm, It connected with the ball-point pen tip through the resin holder.
Next, from the rear part of the polypropylene pipe, an ink backflow prevention body (liquid stopper) having viscoelasticity mainly composed of polybutene is filled, and a tail plug is fitted to the rear part of the pipe. After the cylinder was assembled and the cap was fitted, a deaeration process was performed by a centrifugal process to obtain a ballpoint pen.
The ball-point pen tip has a stainless steel ball having a diameter of 0.7 mm held at the tip end of a tip formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, and the ball is a spring. The cap is biased forward by the body, and the cap is formed by mounting silicone rubber as a friction body on the top.

Black characters (handwriting) were formed by writing on the paper using the ballpoint pen.
The handwriting has a black color at room temperature (25 ° C.), and when the characters are scraped with a friction body attached to the cap, the characters are discolored and become colorless, and this state does not cool to −22 ° C. or lower. Could be maintained as long as possible.
When the paper surface was put in a freezer and cooled to −22 ° C. or lower, the characters again showed a discoloration behavior that turned black, and the discoloration behavior could be reproduced repeatedly.

Example 2
Preparation of thermosensitive color-changing color memory microcapsule pigment (a) As component (3- (4-diethylamino-2-hexyloxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4- 2.0 parts by weight of azaphthalide, 8.0 parts by weight of bis (3-methyl-4-hydroxyphenyl) sulfide as component (b), 5.0 parts by weight of 1,1-bis (4′-hydroxyphenyl) hexafluoropropane A temperature-sensitive color-changing color memory composition comprising 50.0 parts by weight of 4-benzyloxyphenylethyl caprate as the component (c) is uniformly heated and dissolved, and the aromatic polyvalent isocyanate prepolymer 30 is used as the wall film material. A solution prepared by mixing 0.0 part by weight and 40.0 parts by weight of a co-solvent is emulsified and dispersed in an 8% aqueous solution of polyvinyl alcohol so as to form fine droplets. After stirring for a while, 2.5 parts by weight of a water-soluble aliphatic modified amine was added, and stirring was further continued for 6 hours to obtain a temperature-sensitive color-changing color memory microcapsule pigment suspension.
The suspension was centrifuged to isolate a thermochromic color memory microcapsule pigment.
The microcapsule pigment changes its color from blue to colorless with temperature change.

Preparation of temperature-sensitive color-changing color memory ink 25.7 parts by weight of the above microcapsule pigment, 0.2 parts by weight of an acidic dye [Eisulosin, Eisen Hodogaya Co., Ltd.], 0.2 of succinoglycan (shear thinning agent) Parts by weight, 5.5 parts by weight of urea, 7.5 parts by weight of glycerin, nonionic permeability imparting agent [manufactured by San Nopco Co., Ltd., trade name: Nopco SW-WET-366] 0.03 parts by weight, modified silicone Defoaming agent [manufactured by Nippon Silicone Co., Ltd., trade name: FS Antifoam 013B] 0.15 parts by weight, preservative [manufactured by Zeneca Co., Ltd., trade name: Proxel XL-2], lubricant [ Daiichi Kogyo Seiyaku Co., Ltd. Plysurf A212C] A temperature-sensitive color-changing color memory ink comprising 0.5 parts by weight, triethanolamine 0.5 parts by weight and water 59.62 parts by weight was prepared.

Preparation of writing instrument 0.97 g of the above ink (previously cooled to −20 ° C. or lower and allowed to stand at room temperature after coloring the microcapsule pigment in pink) was sucked and filled in 0.97 g of polypropylene pipe having an inner diameter of 4.4 mm. The ballpoint pen tip was connected via a resin holder.
Next, from the rear part of the polypropylene pipe, an ink backflow prevention body (liquid stopper) having viscoelasticity mainly composed of polybutene is filled, and a tail plug is fitted to the rear part of the pipe. After the cylinder was assembled and the cap was fitted, a deaeration process was performed by a centrifugal process to obtain a ballpoint pen.
The ball-point pen tip has a stainless steel ball having a diameter of 0.7 mm held at the tip end of a tip formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, and the ball is a spring. The cap is biased forward by the body, and the cap is formed by mounting silicone rubber as a friction body on the top.

A purple character (handwriting) was formed by writing on the paper surface using the ballpoint pen.
The handwriting has a purple color at room temperature (25 ° C.), and when the character is scraped with a friction body attached to the cap, the character changes color and becomes pink, and this state does not cool to −22 ° C. or lower. Could be maintained as long as possible.
When the paper surface was placed in a freezer and cooled to −22 ° C. or lower, the letters again showed a color change behavior that turned purple, and the color change behavior could be reproduced repeatedly.

Example 3
Preparation of thermosensitive color-changing color memory microcapsule pigment (a) 2- (butylamino) -8- (diphenylamino) -4-methylspiro [5H- [1] benzopyrano [2-3-g] pyrimidine- as component (a) 5,1 (3′H) -isobenzofuran] -3-one 2.0 parts by weight, (ro) component 1,1-bis (4′-hydroxyphenyl) n-decane 3.0 parts by weight, A temperature-sensitive color-changing color memory composition comprising 50.0 parts by weight of 4-benzyloxyphenylethyl caprate as a component of 5.0 parts by weight of 1-bis (4'-hydroxyphenyl) hexafluoropropane A solution prepared by heating and dissolving and mixing 30.0 parts by weight of an aromatic polyisocyanate prepolymer and 40.0 parts by weight of a co-solvent as a wall membrane material is made into fine droplets in an 8% aqueous polyvinyl alcohol solution. The mixture was emulsified and dispersed at 70 ° C. for about 1 hour, 2.5 parts by weight of a water-soluble aliphatic modified amine was added, and the mixture was further stirred for 6 hours to change the temperature-sensitive color change color memory microcapsule pigment. A suspension was obtained.
The suspension was centrifuged to isolate a thermochromic color memory microcapsule pigment.
The microcapsule pigment changes its color from pink to colorless when the temperature changes.

Preparation of temperature-sensitive color-changing color memory ink 25.7 parts by weight of the microcapsule pigment, 1.0 part by weight of acidic dye [Brilliant Blue FCF manufactured by Eisen Hodogaya Co., Ltd.], xanthan gum (shear thinning agent) 33 parts by weight, 10.0 parts by weight of urea, 10.0 parts by weight of glycerol, 0.6 part by weight of nonionic penetrability imparting agent [manufactured by San Nopco Co., Ltd., trade name: Nopco SW-WET-366], modified silicone 0.1 part by weight of an antifoaming agent (manufactured by San Nopco, trade name: Nopco 8034), 0.1 part by weight of an antiseptic (trade name: Proxel XL-2, manufactured by Zeneca), 52.17 water A temperature-sensitive color-change color memory ink consisting of parts by weight was prepared.

Preparation of writing instrument 0.97 g of the above ink (previously cooled to −20 ° C. or lower and allowed to stand at room temperature after coloring the microcapsule pigment in pink) was sucked and filled in 0.97 g of polypropylene pipe having an inner diameter of 4.4 mm. The ballpoint pen tip was connected via a resin holder.
The ballpoint pen tip has a stainless steel ball having a diameter of 0.6 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 mounting silicone rubber on the top as a friction body.

A purple character (handwriting) was formed by writing on the paper surface using the ballpoint pen.
The handwriting has a purple color at room temperature (25 ° C.). When the character is scraped with a friction body attached to the cap, the character changes color to blue, and this state is not cooled to −22 ° C. or lower. Could be maintained.
When the paper surface was placed in a freezer and cooled to −22 ° C. or lower, the letters again showed a color change behavior that turned purple, and the color change behavior could be reproduced repeatedly.

Example 4
Preparation of thermosensitive color-changing color memory microcapsule pigment (a) 2- (butylamino) -8- (diphenylamino) -4-methylspiro [5H- [1] benzopyrano [2-3-g] pyrimidine- as component (a) 5,1 (3′H) -isobenzofuran] -3-one 2.0 parts by weight, (ro) component 1,1-bis (4′-hydroxyphenyl) n-decane 3.0 parts by weight, Uniform temperature-sensitive color-changing color memory composition comprising 5.0 parts by weight of 1-bis (4'-hydroxyphenyl) hexafluoropropane and 50.0 parts by weight of 4-benzyloxyphenylethyl caprate as component (c) A solution prepared by mixing 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 40.0 parts by weight of a co-solvent as a wall film material was dissolved into fine droplets in an 8% aqueous polyvinyl alcohol solution. The mixture was emulsified and dispersed, and stirred at 70 ° C. for about 1 hour. Then, 2.5 parts by weight of a water-soluble aliphatic modified amine was added, and stirring was further continued for 6 hours to make a thermosensitive color-change color memory microcapsule pigment. A suspension was obtained.
The suspension was centrifuged to isolate a thermochromic color memory microcapsule pigment.
The microcapsule pigment changes its color from pink to colorless when the temperature changes.

Preparation of temperature-sensitive color-changing color memory ink 25.7 parts by weight of the microcapsule pigment, 0.2 parts by weight of succinoglycan (shear thinning agent), 5.5 parts by weight of urea, 7.5 parts by weight of glycerin, Nonionic permeability imparting agent [manufactured by San Nopco Co., Ltd., trade name: Nopco SW-WET-366] 0.03 parts by weight, modified silicone antifoaming agent [manufactured by Nippon Silicone Co., Ltd., trade name: FS Antifoam 013B] 0.15 parts by weight, preservative [Zeneca Co., Ltd., trade name: Proxel XL-2] 0.1 parts, lubricant [Daiichi Kogyo Seiyaku Co., Ltd. Prisurf A212C] 0.5 parts by weight A temperature-sensitive color-changing color memory ink comprising 0.5 parts by weight of triethanolamine and 59.82 parts by weight of water was prepared.

Preparation of writing instrument 0.97 g of the above ink (previously cooled to −20 ° C. or lower and allowed to stand at room temperature after coloring the microcapsule pigment in pink) was sucked and filled in 0.97 g of polypropylene pipe having an inner diameter of 4.4 mm. The ballpoint pen tip was connected via a resin holder.
Next, an ink backflow prevention body (liquid stopper) having viscoelasticity mainly composed of polybutene was filled from the rear part of the polypropylene pipe to obtain a ballpoint pen refill.
The ball-point pen refill was accommodated in the shaft cylinder, and a knock member at the rear end of the shaft cylinder was pressed to obtain a knock-type ball pen in which the ball-point pen tip was drawn out from the tip of the shaft cylinder.
The ballpoint pen tip has a stainless steel ball having a diameter of 0.6 mm held at the tip end of a tip formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, and the ball is a spring. It is energized forward by the body.

A pink character (handwriting) was formed by writing on the paper using the ballpoint pen. The handwriting has a pink color at room temperature (25 ° C.), and when characters are scraped with a friction body, the characters are discolored and become colorless, and this state is maintained unless cooled to −22 ° C. or lower. I was able to.
When the paper surface was placed in a freezer and cooled to -22 ° C or lower, the characters again showed a discoloration behavior that turned pink, and the discoloration behavior could be reproduced repeatedly.

Example 5
Preparation of thermosensitive color-changing color memory microcapsule pigment (a) As component (3- (4-diethylamino-2-hexyloxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4- 4. 2.0 parts by weight of azaphthalide, 3.0 parts by weight of 1,1-bis (4′-hydroxyphenyl) n-decane as component (b), 1,1-bis (4′-hydroxyphenyl) hexafluoropropane A thermosensitive color-changing color memory composition comprising 0 parts by weight and 50.0 parts by weight of 4-benzyloxyphenylethyl caprate as the component (c) is uniformly heated and dissolved, and an aromatic polyvalent isocyanate is used as a wall film material. A solution prepared by mixing 30.0 parts by weight of the prepolymer and 40.0 parts by weight of the co-solvent is emulsified and dispersed in an 8% aqueous solution of polyvinyl alcohol so as to form fine droplets. After continuing stirring, 2.5 parts by weight of a water-soluble aliphatic modified amine was added, and stirring was further continued for 6 hours to obtain a temperature-sensitive color-changing color memory microcapsule pigment suspension.
The suspension was centrifuged to isolate a thermochromic color memory microcapsule pigment.
The microcapsule pigment changes its color from blue to colorless with temperature change.

Preparation of temperature-sensitive color-changing color memory ink 20.0 parts by weight of the above microcapsule pigment, 5.0 parts by weight of urea, 15.0 parts by weight of glycerin, 5.0 parts by weight of carboxylic acid, a lubricant [Daiichi Kogyo Seiyaku Co., Ltd. Plysurf AL manufactured] A temperature-sensitive color-changing color memory ink comprising 0.5 parts by weight, 0.5 parts by weight of triethanolamine, and 54.0 parts by weight of water was prepared.

Preparation of a writing instrument The ink (which was previously cooled to -20 ° C. or less to develop a blue color of the microcapsule pigment and left at room temperature) was directly accommodated in the shaft cylinder, and a comb groove in front of the shaft cylinder. A ballpoint pen provided with a ballpoint pen tip held by a metal member having a cylindrical ink adjusting member and having a stainless steel ball having a diameter of 0.5 mm formed by ball machining on a ball receiving seat was obtained.
The ballpoint pen is provided with a detachable cap, and the cap is provided with silicone rubber as a friction body on the top.

Blue letters (handwriting) were formed by writing on the paper using the ballpoint pen.
The handwriting has a blue color at room temperature (25 ° C.), and when the character is scraped with a friction body attached to the cap, the character is discolored and becomes colorless, and this state does not cool to −22 ° C. or lower. Could be maintained as long as possible.
When the paper surface was placed in a freezer and cooled to −22 ° C. or lower, the characters again showed a discoloration behavior that turned blue, and the discoloration behavior could be reproduced repeatedly.

Example 6
Preparation of thermosensitive color-change color memory microcapsule pigment (i) As component (4), 3.0 parts by weight of 4- [2,6-bis (2-ethoxyphenyl) -4-pyridinyl] -N, N-dimethylbenzenamine The temperature-sensitive discoloration comprising 10.0 parts by weight of 1,1-bis (4′-hydroxyphenyl) hexafluoropropane as the component (b) and 50.0 parts by weight of 4-benzyloxyphenylethyl laurate as the component (c) The color color memory composition was uniformly heated and dissolved, and a solution prepared by mixing 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 40.0 parts by weight of a co-solvent as a wall film material was added to an aqueous 8% polyvinyl alcohol solution. After emulsifying and dispersing to form fine droplets, stirring at 70 ° C. for about 1 hour, adding 2.5 parts by weight of water-soluble aliphatic modified amine, and further stirring for 6 hours, temperature-sensitive discoloration color A chromatic memory microcapsule pigment suspension was obtained.
The suspension was centrifuged to isolate a thermochromic color memory microcapsule pigment.
The microcapsule pigment changes color from yellow to colorless with temperature change.

Preparation of temperature-sensitive color-changing color memory ink 18.8 parts by weight of the microcapsule pigment, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: Cellosize WP-09B], 0.4 parts by weight, glycerin 5.0 parts by weight Parts, modified silicone antifoaming agent [manufactured by Nippon Silicone Co., Ltd., trade name: FS Antifoam 013B] 0.02 parts by weight, preservative [manufactured by Zeneca Co., Ltd., trade name: Proxel XL-2] 1.0 Part, and 74.78 parts by weight of water were prepared.

Fabrication of a writing instrument A fiber-focused ink occlusion body in which the ink (previously cooled to −20 ° C. or less and allowed to stand at room temperature after coloring the microcapsule pigment in yellow) is coated with a polyester resin sliver with a synthetic resin film ( A marking pen was obtained by impregnating 2.0 g of the porosity (about 80%) into the shaft cylinder and storing it in the shaft cylinder, and attaching a chisel-type fiber pen body (porosity about 50%) to the tip of the shaft cylinder.
The marking pen is provided with a detachable cap, and the cap is provided with silicone rubber as a friction body at the top.

A yellow character (handwriting) was formed by writing on the paper using the marking pen.
The handwriting has a yellow color at room temperature (25 ° C.), and when the character is scraped with a friction body attached to the cap, the character is discolored and becomes colorless, and this state does not cool to −22 ° C. or lower. Could be maintained as long as possible.
When the paper surface was placed in a freezer and cooled to −22 ° C. or lower, the characters again showed a discoloration behavior that turned yellow, and the discoloration behavior could be reproduced repeatedly.

Example 7
Preparation of thermosensitive color-changing color memory microcapsule pigment (a) 2- (butylamino) -8- (diphenylamino) -4-methylspiro [5H- [1] benzopyrano [2-3-g] pyrimidine- as component (a) 5,1 (3′H) -isobenzofuran] -3-one 2.0 parts by weight, (ro) component 1,1-bis (4′-hydroxyphenyl) hexafluoropropane 5.0 parts by weight, 1, Uniform temperature-sensitive color-changing color memory composition comprising 3.0 parts by weight of 1-bis (4'-hydroxyphenyl) n-decane and 50.0 parts by weight of 4-benzyloxyphenylethyl caprate as component (c) A solution prepared by mixing 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 40.0 parts by weight of a co-solvent as a wall film material was dissolved into fine droplets in an 8% aqueous polyvinyl alcohol solution. The mixture was emulsified and dispersed, and stirred at 70 ° C. for about 1 hour. Then, 2.5 parts by weight of a water-soluble aliphatic modified amine was added, and stirring was further continued for 6 hours to make a thermosensitive color-change color memory microcapsule pigment. A suspension was obtained.
The suspension was centrifuged to isolate a thermochromic color memory microcapsule pigment.
The microcapsule pigment changes its color from pink to colorless when the temperature changes.

Preparation of temperature-sensitive color-changing color memory ink 18.8 parts by weight of the microcapsule pigment, 0.2 parts by weight of anhydrous sodium carbonate, acid dye [manufactured by Eisen Hodogaya Co., Ltd., trade name: Quinoline Yellow WS] 0.5 Parts by weight, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cello size WP-09B] 0.4 parts by weight, glycerin 5.0 parts by weight, modified silicone antifoaming agent [manufactured by Nippon Silicone Co., Ltd., product Name: FS Antifoam 013B] 0.02 part by weight, preservative [manufactured by Zeneca Co., Ltd., trade name: Proxel XL-2] 1.0 part, temperature sensitive color change color memory consisting of 74.08 part by weight of water An ink was prepared.

Fabrication of a writing instrument A fiber-focused ink occlusion body in which the above-mentioned ink (previously cooled to -20 ° C. or less and colored with a microcapsule pigment in pink and then left at room temperature) is covered with a polyester sliver with a synthetic resin film. 2.0 g of (porosity of about 89%) was impregnated and accommodated in the shaft cylinder, and a chisel type fiber pen body (porosity of about 53%) was attached to the tip of the shaft cylinder to obtain a marking pen.
The marking pen is provided with a detachable cap, and the cap is provided with silicone rubber as a friction body at the top.

The marking pen was used to write on the paper surface to form red letters (handwriting).
The handwriting has a red color at room temperature (25 ° C.). When the character is scraped with a friction body, the character is discolored to become yellow, and this state can be maintained unless it is cooled to −22 ° C. or lower. did it.
When the paper surface was put in a freezer and cooled to -22 ° C. or lower, the characters again showed a discoloration behavior that turned red, and the discoloration behavior could be reproduced repeatedly.

Example 8
Preparation of thermosensitive color-changing color memory microcapsule pigment a (i) 2,5-part by weight of 1,3-dimethyl-6-diethylaminofluorane as component, 1,1-bis (4'-hydroxy) as component (b) Phenyl) hexafluoropropane 5.0 parts by weight, 1,1-bis (4'-hydroxyphenyl) n-decane 3.0 parts by weight, and (c) component 4-benzyloxyphenylethyl caprate 50.0 parts by weight A solution in which 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer and 40.0 parts by weight of a co-solvent are mixed as a wall film material is uniformly dissolved in a temperature-sensitive color-changing color memory composition comprising 8 After emulsifying and dispersing in fine water in a polyvinyl alcohol solution to form fine droplets, stirring was continued at 70 ° C. for about 1 hour, 2.5 parts by weight of a water-soluble aliphatic modified amine was added, and stirring was further continued for 6 hours. A temperature-sensitive color-change color-memory microcapsule pigment suspension was obtained.
The suspension was centrifuged to isolate thermochromic color memory microcapsule pigment a.
The microcapsule pigment changes color from orange to colorless with temperature change.

Preparation of thermosensitive color-changing color memory microcapsule pigment b (a) 2.5 parts by weight of 3,3-bis- (2-ethoxy-4-diethylaminiamino) 4-azaphthalide as component (b) 1 as component (b) , 1-bis (4′-hydroxyphenyl) hexafluoropropane 5.0 parts by weight, 1,1-bis (4′-hydroxyphenyl) n-decane 3.0 parts by weight, (c) capric acid 4- A temperature-sensitive color-changing color memory composition comprising 50.0 parts by weight of benzyloxyphenylethyl is uniformly heated and dissolved, and 30.0 parts by weight of an aromatic polyvalent isocyanate prepolymer as a wall film material, 40.0% of a co-solvent The mixed solution is emulsified and dispersed in 8% aqueous polyvinyl alcohol so as to form fine droplets, and after stirring at 70 ° C. for about 1 hour, 2.5 parts by weight of a water-soluble aliphatic modified amine is added. The mixture was further stirred for 6 hours to obtain a temperature-sensitive color-change color memory microcapsule pigment suspension.
The suspension was centrifuged to isolate thermochromic color memory microcapsule pigment b.
The microcapsule pigment changes its color from blue-green to colorless when the temperature changes.

Preparation of temperature-sensitive color-changing color memory ink 18.8 parts by weight of the above microcapsule pigment a, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09B], 0.4 parts by weight, glycerin 5.0 parts by weight Parts, modified silicone antifoaming agent [manufactured by Nippon Silicone Co., Ltd., trade name: FS Antifoam 013B] 0.02 parts by weight, preservative [manufactured by Zeneca Co., Ltd., trade name: Proxel XL-2] 1.0 Part, and 74.78 parts by weight of water were prepared.
Separately from this, 18.8 parts by weight of microcapsule pigment b, hydroxyethyl cellulose (manufactured by Union Carbide Japan Co., Ltd., trade name: Cellosize WP-09B), 0.4 parts by weight, glycerin 5.0 parts by weight, modified silicone-based pigment 0.02 part by weight of a foaming agent [manufactured by Nippon Silicone Co., Ltd., trade name: FS Antifoam 013B], 1.0 part of an antiseptic [manufactured by Zeneca Co., Ltd., trade name: Proxel XL-2], 74.78 water A thermochromic color memory ink B consisting of parts by weight was prepared.

Fabrication of a writing instrument A fiber-focused ink occlusion body in which the ink A (previously cooled to −20 ° C. or lower and the microcapsule pigment is colored orange and left at room temperature) is coated with a polyester sliver with a synthetic resin film. (Porosity of about 89%) is impregnated with 1.0 g, accommodated in one of the shaft cylinders provided with a partition in the central part inside, and a chisel-type fiber pen (porosity of about 53%) is attached to the tip of the shaft cylinder It was.
In addition, a fiber-focused ink occlusion body in which ink B (cooled to −20 ° C. or less in advance to develop a microcapsule pigment in blue-green color and allowed to stand at room temperature) covered with a polyester sliver with a synthetic resin film ( (Porosity of about 89%) was impregnated with 1.0 g, accommodated in the other end of the shaft tube, and a chisel-type fiber pen body (porosity of about 53%) was attached to the end of the shaft tube to obtain a double-headed marking pen. .
The marking pen is provided with a detachable cap, and the cap is provided with silicone rubber as a friction body at the top.
An orange character (handwriting) and a blue-green character (handwriting) were formed by writing on the paper using the marking pen.
The handwriting is orange and blue-green at room temperature (25 ° C.). When the characters are scraped with a friction body attached to the cap, the characters are discolored and become colorless, and this state is −22 ° C. or lower. It could be maintained unless cooled down.
When the paper surface was placed in a freezer and cooled to −22 ° C. or lower, the characters again showed a discoloration behavior that turned orange and blue-green, and the discoloration behavior could be reproduced repeatedly.

Example 9
Preparation of thermosensitive color-changing color memory microcapsule pigment (a) As component (3- (4-diethylamino-2-hexyloxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4- 4. 2.0 parts by weight of azaphthalide, 3.0 parts by weight of 1,1-bis (4′-hydroxyphenyl) n-decane as component (b), 1,1-bis (4′-hydroxyphenyl) hexafluoropropane A thermosensitive color-changing color memory composition comprising 0 parts by weight and 50.0 parts by weight of 4-benzyloxyphenylethyl caprate as the component (c) is uniformly heated and dissolved, and an aromatic polyvalent isocyanate is used as a wall film material. A solution prepared by mixing 30.0 parts by weight of the prepolymer and 40.0 parts by weight of the co-solvent is emulsified and dispersed in an 8% aqueous solution of polyvinyl alcohol so as to form fine droplets. After continuing stirring, 2.5 parts by weight of a water-soluble aliphatic modified amine was added, and stirring was further continued for 6 hours to obtain a temperature-sensitive color-changing color memory microcapsule pigment suspension.
The suspension was centrifuged to isolate a thermochromic color memory microcapsule pigment.
The microcapsule pigment changes its color from blue to colorless with temperature change.

Preparation of temperature-sensitive color-changing color memory ink 20.0 parts by weight of the above microcapsule pigment, acid dye [manufactured by Eisen Hodogaya Co., Ltd., trade name: erythrosine], hydroxyethyl cellulose [Union Carbide Japan Co., Ltd. Product name: Serosize WP-09B] 0.6 parts by weight, glycerin 5.0 parts by weight, modified silicone antifoaming agent [manufactured by Nippon Silicone Co., Ltd., trade name: FS Antifoam 013B] 0.02 weight Part, antiseptic [manufactured by Zeneca Co., Ltd., trade name: Proxel XL-2] 1.0 parts, temperature-sensitive color-change color memory ink consisting of 73.18 parts by weight of water was prepared.

Preparation of a writing instrument The ink (which was previously cooled to −20 ° C. or less to cause the microcapsule pigment to develop a blue color and then allowed to stand at room temperature) was directly accommodated in the barrel, and a bullet-type fiber pen body (porosity) A pen holder to which about 50%) was fixed was fitted to the tip of the shaft cylinder through a valve mechanism to obtain a marking pen.
The cap is provided with silicone rubber as a friction body at the top.

A purple character (handwriting) was formed by writing on the paper surface using the ballpoint pen.
The handwriting has a purple color at room temperature (25 ° C.), and when characters are scraped with a friction body, the characters change color to pink, and this state is maintained unless cooled to −22 ° C. or lower. I was able to.
When the paper surface was placed in a freezer and cooled to −22 ° C. or lower, the letters again showed a color change behavior that turned purple, and the color change behavior could be reproduced repeatedly.

Example 10
Preparation of temperature-sensitive color-changing color memory microcapsule pigment c (I) As component, 2- (2-chloroanilino) -6-di-n-butylaminofluorane (5.0 parts by weight), (B) component 1,1 -4.5 parts by weight of bis (4'-hydroxyphenyl) n-decane, 7.5 parts by weight of 1,1-bis (4'-hydroxyphenyl) hexafluoropropane, and 4-benzyloxy laurate as component (c) A temperature-sensitive color-changing color memory composition comprising 50.0 parts by weight of phenylethyl is uniformly heated and dissolved, and 30.0 parts by weight of an aromatic polyisocyanate prepolymer as a wall film material and 40.0 parts by weight of a co-solvent Is mixed in an aqueous solution of 8% polyvinyl alcohol so as to form fine droplets, and stirring is continued at 70 ° C. for about 1 hour, and then 2.5 parts by weight of a water-soluble aliphatic modified amine is added. The mixture was continuously stirred for 6 hours to obtain a temperature-sensitive color-change color memory microcapsule pigment suspension.
The suspension was centrifuged to isolate thermochromic color memory microcapsule pigment c.
The microcapsule pigment changes color from black to colorless due to temperature change.

Preparation of thermochromic color memory microcapsule pigment d (a) 6 '-[ethyl (4-methylphenyl) amino] -2'-(methylphenylamino) -spiro [isobenzofuran-1 (3H) as component (a) , 9 '-(9H) xanthen] -3-one 8.0 parts by weight, 4.5 parts by weight of 1,1-bis (4'-hydroxyphenyl) n-decane as component (b), 1,1-bis A temperature-sensitive color-changing color memory composition comprising 7.5 parts by weight of (4'-hydroxyphenyl) hexafluoropropane and 50.0 parts by weight of 4-benzyloxyphenylethyl laurate as component (c) is uniformly heated. Dissolve and mix a solution containing 30.0 parts by weight of aromatic polyisocyanate prepolymer and 40.0 parts by weight of co-solvent as a wall film material so as to form fine droplets in an 8% aqueous polyvinyl alcohol solution. The mixture was emulsified and dispersed, and stirred at 70 ° C. for about 1 hour. Then, 2.5 parts by weight of a water-soluble aliphatic modified amine was added, and stirring was further continued for 6 hours to suspend the temperature-sensitive color-changing color memory microcapsule pigment. A liquid was obtained.
The suspension was centrifuged to isolate a thermochromic color memory microcapsule pigment d.
The microcapsule pigment changes its color from dark green to colorless with temperature change.

Preparation of temperature-sensitive color-changing color memory ink The microcapsule pigment c10.0 parts by weight, the microcapsule pigment d10.0 parts by weight, the acid dye [manufactured by Eisen Hodogaya Co., Ltd., trade name: erythrosine] 0.5 parts by weight , Hydroxyethylcellulose [Union Carbide Japan Co., Ltd., trade name: Cello size WP-09B] 0.6 parts by weight, Glycerin 5.0 parts by weight, Modified silicone antifoaming agent [Nippon Silicone Co., Ltd., trade name: FS Antifoam 013B] 0.02 part by weight, preservative [manufactured by Zeneca Co., Ltd., trade name: Proxel XL-2] 1.0 part, temperature-sensitive color-change color memory ink comprising 72.88 parts by weight of water Prepared.

Preparation of a writing instrument The ink (cooled in advance to -20 ° C or less and made the microcapsule pigment black and dark green and then left at room temperature) is directly housed in the shaft tube, and the front in the shaft tube A marking pen having a comb groove-shaped ink adjusting member and a chisel-type fiber pen body (porosity of about 53%) was obtained.
The marking pen is provided with a detachable cap, and the cap is provided with silicone rubber as a friction body at the top.

Black characters (handwriting) were formed by writing on the paper using the ballpoint pen.
The handwriting has a black color at room temperature (25 ° C.), and when the character is scraped with a friction body attached to the cap, the character changes color and becomes red, unless this state is cooled to −22 ° C. or lower. Could be maintained.
When the paper surface was put in a freezer and cooled to −22 ° C. or lower, the characters again showed a discoloration behavior that turned black, and the discoloration behavior could be reproduced repeatedly.

It is a graph explaining the hysteresis characteristic in the color density-temperature curve of the temperature-sensitive color-change color memory composition used for this invention. It is a graph explaining the hysteresis characteristic in the color density-temperature curve of the temperature-sensitive color-change color memory composition used for this invention.

Explanation of symbols

T ₁ complete coloring temperature T ₂ minimum holding temperature T ₃ maximum holding temperature T ₄ complete color erasing temperature ΔH Hysteresis width

Claims (4)

(B) Electron-donating color-forming organic compound, (b) electron-accepting compound, (c) As a reaction medium for controlling the color reaction of (b) and (b), the following general formula (1) An ink composition for a temperature-sensitive color-changing color memory writing instrument comprising at least a microcapsule pigment encapsulating a temperature-sensitive color-changing color memory composition comprising a homogeneous solution of an ester compound.

(In the formula, R represents an alkyl group or alkenyl group having 4 or more carbon atoms.) (B) a compound having a phenolic hydroxyl group having at least 3 or more benzene rings and having a molecular weight of 250 or more, or a compound having a phenolic hydroxyl group represented by formula (2) The ink composition for a temperature-sensitive color-changing color memory writing instrument according to claim 1.

(In the formula, R represents an alkyl group having 1 to 8 carbon atoms.)   3. The ink composition for a temperature-sensitive color-change color memory writing instrument according to claim 1, wherein the microcapsule pigment changes color by exhibiting a hysteresis width (ΔH) of 40 ° C. to 70 ° C. with respect to a color density-temperature curve. The microcapsule pigment has a color erasability in a normal temperature range in which a complete decoloring temperature (T ₄ ) is 40 ° C. or higher and a minimum holding temperature (T ₂ ) is 20 ° C. or lower with respect to a color density-temperature curve. The ink composition for a temperature-sensitive color-changing color memory writing instrument according to any one of claims 1 to 3.

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