JP5201919B2 - Water-based ink composition for writing instruments, writing instrument containing the same, and writing instrument set - Google Patents

Description

  The present invention relates to a water-based ink composition for a writing instrument, a writing instrument containing it, and a writing instrument set. More specifically, the present invention relates to a water-based ink composition for a writing instrument having color change properties and aroma, a writing instrument containing the composition, and a writing instrument set.

Conventionally, a thermochromic ink composition containing a reversible thermochromic material has been disclosed (for example, see Patent Document 1).
Moreover, the aroma ink composition containing a fragrance | flavor is disclosed (for example, refer patent document 2).
JP-A-9-124993 JP 2000-248221 A

  The handwriting formed on the writing surface using the ink composition is discolored or scented due to temperature change, but the handwriting may be discolored or only scented to be monotonous and tired. there were.

The present invention, initial handwriting emits a scent, moreover, the handwriting is a water based ink composition for a writing instrument that emits initial different aroma with discoloration, a colorant that changes color when heated, and water, and flavors, the A water-based ink composition for a writing instrument comprising at least microcapsules containing a fragrance having a different scent from the fragrance is required.
Furthermore, the colorant that changes color upon heating controls (i) the electron donating color-forming organic compound, (b) the electron-accepting compound, and (c) the color reaction of (i) and (b) above. A microcapsule pigment including a reversible thermochromic composition comprising at least a reaction medium, and the microcapsule pigment exhibits a large hysteresis characteristic with respect to a color density-temperature curve and exhibits a tautomerism between a colored state and a colorless state. a pigment retention temperature range of both states are both a normal temperature range, the pigment in the process of temperature increase from the colored state, begins decolorized to reach a temperature t _3, a temperature t ₄ or more than the temperature t ₃ In the process in which the temperature becomes completely colorless in the temperature range, and in the process of decreasing the temperature from the colorless state, the coloring starts when reaching the temperature t ₂ lower than the temperature t ₃ , and completely in the temperature range below the temperature t ₁ lower than the temperature t _2. Arrival Becomes color state, shows a hysteresis characteristic colored state and the colorless state in a temperature range are selectively retained between the temperature t ₂ and the temperature t _3, the temperature t ₁ is in the range of -30 to 0 ° C., a temperature It is necessary that t ₄ is in the range of 45 to 95 ° C., contains a non-discoloring colorant, and that the fragrance not encapsulated in the microcapsule is selected from the fragrance included in the fragrance emulsion or cyclodextrin. To do.
Furthermore, a writing instrument set including the writing instrument containing the water-based ink composition for writing instruments, the writing instrument provided with a friction member, the writing instrument containing the aqueous ink composition for writing instruments, and a friction body is required.

  The present invention includes a water-based ink composition for writing instruments having a surprising and novel property in which handwriting formed on a writing surface emits a scent, and the handwriting changes color due to temperature change and emits a scent different from the initial, and the same. Writing instruments and writing instrument sets can be provided.

The present invention is a water-based ink composition for a writing instrument including a colorant that changes color by heating, water, a fragrance, and a microcapsule that contains a fragrance different from the fragrance, and the colorant that changes color by heating Is preferably a microcapsule pigment in which a reversible thermochromic composition is encapsulated in a microcapsule wall film.
As the microcapsule pigment, the color changes before and after a predetermined temperature (color change point) described in JP-B-51-44706, JP-B-51-44707, JP-B-1-29398, and the like. In the temperature range above the high temperature side discoloration point, the color disappears, and the color development state occurs in the temperature range below the low temperature side discoloration point. The state is maintained while the heat or cold necessary to develop the state is applied, but when the heat or cold is no longer applied, the state returns to the state exhibited at room temperature, and the hysteresis width is relatively small. A heat decolorable microcapsule pigment encapsulating a reversible thermochromic composition having 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-erasable microcapsule pigment containing a reversible thermochromic composition having color memory in the temperature range between t _{2 and} t ₃ (substantially two-phase holding temperature range) is also applicable (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, both states of the colored state and the decolored state can coexist, a temperature range of between t ₂ and t ₃ is a region having a large difference in color density It is a real 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 is a temperature that can be obtained only in a freezing room, a cold district, etc., that is, −30 to 0 ° C., preferably −30 to − 5 ° C., more preferably −30 to −10 ° C., and the 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 By specifying 90 ° C., more preferably 60 to 80 ° C., and specifying the ΔH value 40 to 60 ° C., it is possible to effectively function to maintain colors exhibited in a normal state (daily life temperature range). .

Specific examples of the compounds (a), (b) and (c) are shown below.
As the component (a) of the present invention, that is, the electron donating color-forming organic compound, diphenylmethane phthalides, phenyl indolyl phthalides, indolyl phthalides, diphenyl methane azaphthalides, phenyl indolyl azaphthalide , Fluorans, stylinoquinolines, diazarhodamine lactones, etc., and these compounds are exemplified 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-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. 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, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) ethylpropionate, 2,2-bis (4-hydroxyphenyl)- 4-methylpentane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 2,2-bis (4-hydroxyphenyl) n-heptane, 2,2-bis It is 4-hydroxyphenyl) n- nonane.
The compound having a phenolic hydroxyl group can develop the most effective thermochromic property, but aromatic carboxylic acids and aliphatic carboxylic acids having 2 to 5 carbon atoms, carboxylic acid metal salts, acidic phosphate esters and their It may be a compound selected from metal salts, 1,2,3-triazole and derivatives thereof.

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

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

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

〔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。〕 Furthermore, as the component (c), a compound represented by the following general formula (1) described in JP-A-2006-137886, or a general formula (described below) described in JP-A-2006-188660 ( The compound represented by 2) is preferably used.

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

[Wherein, R represents an alkyl group or 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 The alkoxy group of number 1-4, and a halogen are shown. ]

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.
In the formula (2), R represents an alkyl group or alkenyl group having 8 or more carbon atoms, preferably an alkyl group having 10 to 24 carbon atoms, more preferably an alkyl group having 12 to 22 carbon atoms.
Examples of the compound include 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- Benzyloxyphenylethyl, octadecanoic acid-4-benzyloxyphenylethyl, 1,1-diphenylmethyl octanoate, 1,1-diphenylmethyl nonanoate, 1,1-diphenylmethyl decanoate, 1,1-didecanoic acid Phenylmethyl, 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 Examples include 1,1-diphenylmethyl and 1,1-diphenylmethyl octadecanoate.

  Furthermore, as an electron-accepting compound, a specific alkoxyphenol compound having a linear or side chain alkyl group having 3 to 18 carbon atoms (Japanese Patent Laid-Open No. 11-129623), a specific hydroxybenzoic acid ester (Japanese Patent Laid-Open No. 2001-105732). Gazette), gallic acid ester (Japanese Patent Laid-Open No. 2003-253149) and the like, and a heat-colorable microcapsule pigment encapsulating a reversible thermochromic composition can also be applied (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, but the component ratio that generally provides the desired color change characteristics is (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 microencapsulation of the reversible thermochromic composition includes interfacial polymerization method, interfacial polycondensation method, in situ polymerization method, submerged curing coating method, phase separation method from aqueous solution, phase separation method from organic solvent, melt dispersion There are a cooling method, an air suspension coating method, a spray drying method, and the like, which are appropriately selected according to the application. 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 form of the microcapsule pigment does not refuse application of a circular cross-section, but a non-circular cross-section is effective.
The handwriting formed by writing, the microcapsule pigment is closely oriented and fixed in close contact with the writing surface on the long diameter side (maximum outer diameter side), and exhibits a high concentration of color development. The microcapsule pigment is slightly elastically deformed into a shape that relaxes the external force against the external force caused by friction caused by the frictional material, and the destruction of the microcapsule wall film is suppressed, and it is effectively expressed without impairing the thermal discoloration function. Can be made.
The above microcapsule pigments (including those having a circular cross-sectional shape) exhibit a decrease in ink outflow in systems where the average maximum outer diameter exceeds 5.0 μm, while the average maximum outer diameter is In a system of 0.5 μm or less, it is difficult to show high density color development. Preferably, the average value of the maximum outer diameter is in the range of 1 to 4 μm, the average particle diameter of the microcapsule [(maximum outer diameter + minimum at the center) The outer diameter) / 2] is preferably in the range of 1 to 3 μm.
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.

An ink composition that changes color from colored (1) to colored (2) by heating is obtained by incorporating a general colored dye or pigment as a non-color-changing colorant in the ink together with the reversible thermochromic microcapsule pigment. It is done.
Examples of the dye include acid dyes, basic dyes, and direct dyes, and pigments include inorganic pigments such as carbon black and ultramarine blue, phthalocyanine-based, azo-based, anthraquinone-based, diketopyrrolopyrrole-based, quinacridone-based dyes, Examples thereof include organic pigments such as isoindolinone. As fluorescent pigments, synthetic resin fine particle fluorescent pigments in which various fluorescent dyes are formed into a solid solution in a resin matrix can be used.

The fragrance | flavor contained in the said ink composition is for giving off fragrance at the time of the formation (initial stage) of a handwriting. Although the said fragrance | flavor is divided into food fragrance | flavor (flavor) and cosmetics fragrance | flavor (fragrance), use of food fragrance | flavor with higher safety | security is preferable. In addition, there are water-soluble fragrances, oil-soluble fragrances, and emulsified fragrances in the form of the fragrance. In the case of oil-soluble fragrances, the fragrance is emulsified or included in the cyclodextrin to be used in the ink composition. It is possible to improve the dispersibility of the ink and develop a stable fragrance of handwriting.
Examples of the perfumes include grapefruit oil, orange oil, lemon oil, lime oil, jasmine oil, peppermint oil, rosemary oil, nutmeg oil, cassia oil, lavender oil, cypress oil, hiba oil, fennel oil and other essential oils, hexyl Alcohols such as alcohol, phenylethyl alcohol (rose P), furfuryl alcohol, cycloten, geraniol, aldehydes such as heptanal, octanal, dodecanal, tetradecanal, hexadecanal, octadecanal, benzaldehyde, furfural, ethyl aceto Esters such as acetate, propyl acetate, amyl acetate, linalyl acetate, benzyl acetate, dimethylbenzylcarbinyl acetate, benzylpropionate, nootkatone, ethylpyra Emissions, lemon terpene-less, orange terpene-less, Wanirin, Echiruwanirin, furfuryl mercaptan, aromatic compounds such as Boneoru and heliotrope, alpha-pinene, exemplified β- pinene, terpene oils such as limonene.
In addition, blended fragrances such as banana flavor, blueberry flavor, vanilla flavor, mint flavor, apple flavor, peach flavor, melon flavor, pineapple flavor, grape flavor, lilac flavor, jasmine flavor, etc. are used. You can also
The microcapsules enclosing the fragrance contained in the ink composition are those in which the fragrance is encapsulated in a microcapsule wall film, and the microencapsulation is the same as the microencapsulation of the reversible thermochromic composition. .
The capsule is destroyed by rubbing a handwriting including a microcapsule encapsulating the fragrance with a finger or rubbing using a friction body, and the fragrance of the encapsulated fragrance can be enjoyed.
Therefore, in the initial stage, the fragrance of the fragrance contained in the ink is released, and the fragrance of the fragrance contained in the microcapsule is released by friction.
The fragrance contained in the ink and the fragrance contained in the microcapsule are different from each other. Due to the effect of changing the handwriting and the combined effect of enjoying different fragrances, the water-based ink for writing instruments has high commercial value that is rich in surprise and novelty. A composition, a writing instrument containing the composition, and a writing instrument set are obtained.
In addition, when the fragrance | flavor of the scent of the object which has the same color tone reminiscent from the color tone of ink is used, the water-based ink composition for writing instruments which is still more surprising, and the writing instrument and writing instrument set which accommodated it can be obtained.

  Examples of the ink include a shear-thinning ink containing a shear-thinning agent, and an aggregating ink in which a microcapsule pigment is suspended in a gentle aggregation state using a water-soluble polymer flocculant.

By adding the shear thinning agent, it is possible to suppress agglomeration and sedimentation of the microcapsule 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 is in the form of a ballpoint pen, ink leakage from the gap between the ball and the tip when not in use is prevented, or the ink flows backward when the writing tip is left upward (upright state). 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 polyoxyethylene alkyl ether-polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ether, nonionic HLB value, such as fatty acid amide is 8-12 surfactants, salts of dialkyl or dialkenyl sulfosuccinic acid. Examples thereof include a mixture of N-alkyl-2-pyrrolidone and an anionic surfactant, and a mixture of polyvinyl alcohol and an acrylic resin.

Examples of the water-soluble polymer flocculant include polyvinyl pyrrolidone, polyethylene oxide, water-soluble polysaccharides, water-soluble cellulose derivatives and the like. Specific examples of water-soluble polysaccharides include tragacanth gum, guar gum, pullulan, cyclodextrin, and specific examples of water-soluble cellulose derivatives include methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, etc. Can be mentioned.
Any water-soluble polymer flocculant that exhibits a gentle bridging action between pigment particles can be applied to the ink, and among these, a water-soluble cellulose derivative works most effectively.
The polymer flocculant can be blended in an amount of 0.05 to 20% by weight based on the total amount of the ink composition.

Water and, if necessary, a water-soluble organic solvent can be added to the ink.
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, 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-pyrrolide And the like can be given.

  Further, when the ink of the present invention is used by filling a ballpoint pen, a higher fatty acid such as oleic acid, a nonionic surfactant having a long chain alkyl group, a polyether-modified silicone oil, thiophosphorous acid tri (alkoxycarbonylmethyl ester) ) And thiophosphite triester (alkoxycarbonylethyl ester), etc., polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether phosphate monoester, polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether It is preferable to 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, resins such as acrylic resin, styrene maleic acid copolymer, cellulose derivative, polyvinyl pyrrolidone, polyvinyl alcohol, and dextrin can be added as necessary to impart fixing properties and viscosity to the paper surface.
In addition, pH adjusters such as inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, organic basic compounds such as water-soluble amine compounds, benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, saponin, etc. Rust preventive agent, coalic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (Methylsulfonyl) pyridine and other preservatives or antifungal agents, urea, nonionic surfactants, reduced or non-reduced starch hydrolysates, oligosaccharides such as trehalose, sucrose, cyclodextrin, glucose, dextrin, sorbit, man Knit, Pi Wetting agents such as sodium phosphate, defoamers, dispersing agents, a surfactant may be added a fluorine-based surfactant or a nonionic improve the ink permeability.

  The ink is put into practical use by filling a writing instrument such as a marking pen or a ballpoint pen with a marking pen tip or a ballpoint pen tip 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 ball-point pen that communicates with the tip mounted on the ink-jet head and has a liquid stopper for backflow prevention in close contact with the end face of the ink.

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

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.
In addition to directly connecting the chip to the ink storage tube, the ink storage tube and the chip may be connected via a connecting member.
The ink storage tube may be a refill type in which the refill is stored in a shaft tube, or the shaft tube itself having a tip attached to a tip is used as an ink container, and ink is directly applied to the shaft tube. It may be filled.

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

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.

  In addition, when filling a marking pen, the structure and shape of the marking pen itself are not particularly limited. For example, a fiber in which an ink occlusion body made of a fiber converging body is built in a shaft cylinder and a capillary gap is formed. A marking in which a pen tip made of a processed body is mounted on a shaft cylinder directly or via a relay member, and the ink occlusion body of the marking pen in which the ink occlusion body and the pen tip are connected is impregnated with cohesive ink. An example is a marking pen in which a pen tip and an ink storage tube are arranged via a pen or a valve body that is opened when the pen tip is pressed, and ink is directly stored in the ink storage tube.

The pen nib is a porous member having a continuous vent selected from a range of porosity of approximately 30 to 70%, such as a fiber processed resin body, a heat-fusible fiber fusion-bonded body, and a felt body, and has a bullet at one end. Processed into a shape according to the purpose such as a shape, a rectangular shape, a chisel shape, etc., and provided for practical use.
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 pumping type, but is preferably a spring pressure that can be pressed and released by writing pressure.

  Furthermore, the form of the ballpoint pen and the marking pen is not limited to those described above, and a composite writing instrument (a double-headed type or a nib with a pen point with a different form or a pen point with which a different color tone is derived) is attached. It may be a pay-out type or the like.

The handwriting formed from the writing instrument containing the ink composition can be discolored by friction with a finger or application of a friction body.
As the friction body, an elastic body such as an elastomer, plastic foam or the like that is rich in elasticity and can generate frictional heat by generating appropriate friction during friction is preferable, but a plastic molded body, stone, wood, Metals and fabrics may be used.
Although it is possible to rub the handwriting by using an eraser, it is preferable to use a friction body as described above because erase scraps are generated at the time of friction.
As the material of the friction body, silicone resin or SEBS resin (styrene ethylene butadiene styrene block copolymer) is preferably used. However, the silicone resin easily adheres to the portion erased by friction, and is repeatedly written. Since the handwriting tends to be repelled, SEBS resin is more preferably used.
Although the said friction body can also combine a writing tool and the member (friction body) of the arbitrary shapes of separate bodies, it can also obtain a writing tool set, but it is excellent in portability by making a friction member (friction body) adhere to a writing instrument.
Examples of the location where the friction member is fixed include a cap tip (top) or a shaft tip (portion where no writing tip is provided).
Furthermore, a small protrusion having an arbitrary shape can be provided on a part of the cap or a part of the shaft tube to form a friction member.

Next, the water-based ink composition for a writing instrument of the present invention, the writing instrument containing it, and the writing instrument set will be described. In addition, the mixing | blending in an Example shows a mass part.
Example 1
Preparation of water-based ink composition for writing instruments (i) 4,5,6,7-tetrachloro-3- [4- (diethylamino) -2-methylphenyl] -3- [1-ethyl-2-methyl- 1H-Indol-3-yl] -1 (3H) -isobenzofuranone, (2) 2,2-bis (4'-hydroxyphenyl) hexafluoropropane as component (5), 4,4'- A microcapsule pigment (t1 :: encapsulating a reversible thermochromic composition having color memory composed of 3 parts of (2-methylpropylidene) bisphenol and 50 parts of 4-benzyloxyphenylethyl caprate as component (c) 18 ° C, t2: -9 ° C, t3: 42 ° C, t4: 63 ° C, ΔH: 66 ° C, average particle size: 2.5 µm, color change from blue to colorless) 20 parts, yellow dye 0.8 parts, Lemon scent [Product name: LEMON TJP-F-000765, manufactured by Takasago International Corporation], 5 parts microcapsule containing 50 parts of capric acid-4-benzyloxyphenylethyl, mint fragrance Product name: Super Emulsion Peppermint 106] 0.2 part, Succinoglucan (shear thinning agent) 0.2 part, Antifungal agent 0.1 part, Lubricant 1.0 part, Triethanol A water-based ink composition for a writing instrument comprising 1.0 part of an amine and 71.7 parts of water was prepared.

Writing instrument production (see Fig. 4)
The ink (previously cooled to develop the color of the microcapsule pigment and then allowed to stand at room temperature) was filled in an ink containing tube 21 having an inner diameter of 4.4 mm and connected to the ballpoint pen tip 3 via the relay member 22. .
Next, an ink backflow prevention body 5 (liquid stopper) having a viscoelastic property mainly composed of polybutene was filled from the rear part of the polypropylene pipe, and a tail plug 23 was fitted to the rear part of the pipe to obtain a refill 2. Further, the refill 2 was assembled in a shaft cylinder 6 (comprised of a front shaft cylinder and a rear shaft cylinder), and after a cap 7 was fitted, a deaeration process was performed by a centrifugal process to obtain a writing instrument 1 (ballpoint pen).
The ballpoint pen tip is formed by holding a stainless steel ball having a diameter of 0.7 mm at the tip of a tip obtained by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface.
In addition, a SEBS resin member having a convex curved top as a friction member 8 is attached to the rear cylinder end.

When writing on the writing paper using the writing instrument, a green handwriting can be formed, and the handwriting gives a scent of mint due to the fragrance.
When the handwriting is rubbed with a friction body provided on the writing instrument, the green handwriting turns yellow, and the lemon-scented fragrance is released outside the capsule from the microcapsule containing the fragrance contained in the handwriting. To come.

Example 2
Preparation of water-based ink composition for writing instruments (i) 4,5,6,7-tetrachloro-3- [4- (diethylamino) -2-methylphenyl] -3- [1-ethyl-2-methyl- 1H-Indol-3-yl] -1 (3H) -isobenzofuranone, (2) 2,2-bis (4'-hydroxyphenyl) hexafluoropropane as component (5), 4,4'- A microcapsule pigment (t1 :: encapsulating a reversible thermochromic composition having color memory composed of 3 parts of (2-methylpropylidene) bisphenol and 50 parts of 4-benzyloxyphenylethyl caprate as component (c) 18 ° C, t2: -9 ° C, t3: 42 ° C, t4: 63 ° C, ΔH: 66 ° C, average particle size: 2.5 µm, color change from blue to colorless) 20 parts, 0.4 part of red dye, Strawberry Rino fragrance [trade name: STRAWBERRY TJP-F-000764] manufactured by Takasago International Corporation, 5 parts microcapsule containing 50 parts of capric acid-4-benzyloxyphenylethyl, perilla fragrance [ Manufactured by Taiyo Kagaku Co., Ltd., trade name: Super Emulsion Perilla 105] 0.2 part, succinoglucan (shear thinning agent) 0.2 part, antifungal agent 0.1 part, lubricant 1.0 part, A water-based ink composition for a writing instrument comprising 1.0 part of triethanolamine and 72.1 parts of water was prepared.

Preparation of writing instrument The ink (which was precooled to develop the color of the microcapsule pigment and allowed to stand at room temperature) was filled in an ink containing tube having an inner diameter of 4.4 mm and connected to a ballpoint pen tip via a relay member. .
Next, an ink backflow prevention body (liquid stopper) having viscoelasticity mainly composed of polybutene was filled from the rear part of the polypropylene pipe, and a tail plug was fitted to the rear part of the pipe to obtain a refill. Further, the refill was incorporated into a shaft cylinder (comprised of a front shaft cylinder and a rear shaft cylinder), a cap was fitted, and then a deaeration process was performed by a centrifugal process to obtain a writing instrument (ball pen).
The ballpoint pen tip is formed by holding a stainless steel ball having a diameter of 0.7 mm at the tip of a tip obtained by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface.
In addition, a SEBS resin member having a convex curved top as a friction member is attached to the rear cylinder end.

When writing on the writing paper using the writing instrument, a purple handwriting can be formed, and the handwriting gives a perfume fragrance.
When the handwriting is rubbed with a friction body provided on the writing instrument, the purple handwriting turns red, and the strawberry fragrance is released from the microcapsule containing the fragrance contained in the handwriting to give the strawberry scent. To come.

Example 3
Preparation of water-based ink composition for writing instruments (i) 4,5,6,7-tetrachloro-3- [4- (diethylamino) -2-methylphenyl] -3- [1-ethyl-2-methyl- 1H-Indol-3-yl] -1 (3H) -isobenzofuranone, (2) 2,2-bis (4'-hydroxyphenyl) hexafluoropropane as component (5), 4,4'- A microcapsule pigment (t1 :: encapsulating a reversible thermochromic composition having color memory composed of 3 parts of (2-methylpropylidene) bisphenol and 50 parts of 4-benzyloxyphenylethyl caprate as component (c) 18 ° C, t2: -9 ° C, t3: 42 ° C, t4: 63 ° C, ΔH: 66 ° C, average particle size: 2.5 µm, color change from blue to colorless) 10 parts, (Butyl Ami ) -8- (dipentylamino) -4-methyl-spiro [5H- [1] benzopyrano [2-3-g] pyrimidin-5,1 '(3'H) -isobenzofuran] -3-one, (B) Component 2,5-bis (4'-hydroxyphenyl) hexafluoropropane 5 parts, 4,4 '-(2-methylpropylidene) bisphenol 3 (C) Component 4-capillic acid 4-benzyl Microcapsule pigment (t1: -16 ° C, t2: -8 ° C, t3: 48 ° C, t4: 58 ° C, ΔH: 65 encapsulating a reversible thermochromic composition having color memory consisting of 50 parts of oxyphenylethyl 10 parts at 10 ° C., average particle diameter: 2.5 μm, color change from pink to colorless, lavender fragrance [manufactured by Takasago International Corporation, trade name: LENDENDAR TJP-F-000763] 10 And 5 parts of microcapsule pigment encapsulating 50 parts of capric acid-4-benzyloxyphenylethyl, 0.2 parts of mango fragrance [manufactured by Saneigen FFI Co., Ltd., trade name: mango flavor] A water-based ink composition for a writing instrument comprising 0.2 part of succinoglucan (shear thinning agent), 0.1 part of an antifungal agent, 1 part of a lubricant, 1 part of triethanolamine and 72.5 parts of water was prepared. .

Preparation of writing instrument The ink (which was precooled to develop the color of the microcapsule pigment and allowed to stand at room temperature) was filled in an ink containing tube having an inner diameter of 4.4 mm and connected to a ballpoint pen tip via a relay member. .
Next, an ink backflow prevention body (liquid stopper) having viscoelasticity mainly composed of polybutene was filled from the rear part of the polypropylene pipe, and a tail plug was fitted to the rear part of the pipe to obtain a refill. Further, the refill was incorporated into a shaft cylinder (comprised of a front shaft cylinder and a rear shaft cylinder), a cap was fitted, and then a deaeration process was performed by a centrifugal process to obtain a writing instrument (ball pen).
The ballpoint pen tip is formed by holding a stainless steel ball having a diameter of 0.7 mm at the tip of a tip obtained by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface.
In addition, a SEBS resin member having a convex curved top as a friction member is attached to the rear cylinder end.

When writing on the writing paper using the writing instrument, a purple handwriting can be formed and the handwriting has a mango scent.
When the handwriting is rubbed with a friction body provided on the writing instrument, the purple handwriting becomes colorless, and the fragrance of lavender scent is released from the microcapsule containing the fragrance contained in the handwriting to give the scent of lavender. It becomes like this.

Example 4
Preparation of water-based ink composition for writing instruments (a) 4,5,6,7-tetrachloro-3- [4- (diethylamino) -2-ethoxyphenyl] -3- (1-ethyl-2-methyl-) as component 1H-Indol-3-yl) -1 (3H) -isobenzofuranone 1 part, (b) as component stearyl gallate 8 parts, (ha) component lauryl alcohol 10.0 parts, heptyl stearate 15 parts , A microcapsule pigment (T ₁ : encapsulating a heat-colorable reversible thermochromic composition comprising 3.0 parts of 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) 5-chlorobenzotriazole. 12 ° C., T ₂ : 22 ° C., T ₃ : 36 ° C., T ₄ : 50 ° C., ΔH: 26 ° C., average particle size: 3.0 μm, color change from colorless to blue) 20 parts, yellow dye 0.8 Department of mint incense Perfume [Takasago Perfume Industry Co., Ltd., trade name: MINT TJP-G-006265] and 5 parts microcapsule containing 50 parts of capric acid-4-benzyloxyphenylethyl, scent of banana fragrance [San-Ei Gen Product name: Banana Flavor NA-3509] 0.2 part, Succinoglucan (shear thinning agent) 0.2 part, Antifungal agent 0.1 part, Lubricant 1 A water-based ink composition for a writing instrument comprising 0.0 part, 1.0 part of triethanolamine and 71.7 parts of water was prepared.

Preparation of writing instrument Fill the ink containing tube with an inner diameter of 4.4 mm with the ink (precooled and decolored the microcapsule pigment, and let it stand at room temperature), and connect it to the ballpoint pen tip via the relay member. It was.
Next, an ink backflow prevention body (liquid stopper) having viscoelasticity mainly composed of polybutene was filled from the rear part of the polypropylene pipe, and a tail plug was fitted to the rear part of the pipe to obtain a refill. Further, the refill was incorporated into a shaft cylinder (comprised of a front shaft cylinder and a rear shaft cylinder), a cap was fitted, and then a deaeration process was performed by a centrifugal process to obtain a writing instrument (ball pen).
The ballpoint pen tip is formed by holding a stainless steel ball having a diameter of 0.7 mm at the tip of a tip obtained by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface.
In addition, a SEBS resin member having a convex curved top as a friction member is attached to the rear cylinder end.

When writing on the writing paper using the writing instrument, a yellow handwriting can be formed, and the handwriting gives a scent of banana due to the fragrance.
When the handwriting is rubbed with a friction body provided on the writing instrument, the yellow handwriting turns green, and the scent of mint is released from the microcapsule containing the fragrance contained in the handwriting to give the scent of mint. To come.

It is explanatory drawing which shows the discoloration behavior of a heat decoloring type reversible thermochromic microcapsule pigment. It is explanatory drawing which shows the discoloration behavior of the heat decoloring type reversible thermochromic microcapsule pigment having color memory. It is explanatory drawing which shows the discoloration behavior of a heat coloring type reversible thermochromic microcapsule pigment. It is explanatory drawing of one Example of the writing instrument which accommodated the water-based ink composition for writing instruments of this invention.

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 type T ₄ Color development start temperature of the reversible thermochromic microcapsule pigment of the heat development type 1 Writing instrument 2 Refill 21 Accommodating tube 22 Relay member 23 Tail plug 3 Ballpoint pen tip 4 Ink 5 Ink backflow prevention body 6 Shaft cylinder 7 Cap 8 Friction member

Claims (8)

A water-based ink composition for a writing instrument comprising at least a colorant that changes color by heating, water, a fragrance, and a microcapsule containing a fragrance different from the fragrance.   The colorant that changes color upon heating is (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that controls the color reaction of (a) and (b) above. The water-based ink composition for a writing instrument according to claim 1, which is a microcapsule pigment encapsulating at least a reversible thermochromic composition comprising: The microcapsule pigment is a pigment that exhibits a large hysteresis characteristic with respect to a color density-temperature curve, exhibits a tautomerism between a colored state and a colorless state, and both holding temperature ranges in both states are in a normal temperature range, and the pigment is in a colored state In the process in which the temperature rises from the temperature t ₃ , the color starts to disappear when reaching the temperature t ₃ , becomes completely colorless in the temperature range above the temperature t ₄ higher than the temperature t ₃ , and in the process in which the temperature falls from the colorless state, the temperature t ₃ begins to coloration from reaching the lower temperature t _2, becomes completely colored state at a lower temperature t ₁ the following temperature range than the temperature t _2, the colored state and colorless in the temperature range between the temperature t ₂ and the temperature t ₃ state indicates a hysteresis characteristic to be selectively retained, the temperature t ₁ is in the range of -30 to 0 ° C., water based ink composition for a writing instrument according to claim 2, wherein the temperature t ₄ is in the range of 45 to 95 ° C. .   The water-based ink composition for a writing instrument according to claim 2 or 3, comprising a non-discoloring colorant. The water-based ink composition for writing instruments as described in any one of Claims 1 thru | or 4 from which the fragrance | flavor which is not included in the said microcapsule is chosen from the fragrance | flavor included by the fragrance | flavor emulsion or the cyclodextrin.   A writing instrument containing the water-based ink composition for a writing instrument according to any one of claims 1 to 5.   The writing instrument according to claim 6, further comprising a friction member.   A writing instrument set comprising the writing instrument according to claim 6 and a friction body.

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