JP2014156605A - Reversibly thermochromic ink composition for a writing utensil and writing utensil housing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an immensely practical reversibly thermochromic ink composition for a writing utensil exhibiting, when decoloring a writing mark formed by writing atop a colored writing surface, a favorable writing mark erasability without a white and turbid afterimage being visually observed on the marked site; and a writing utensil housing the same.SOLUTION: Provided is a reversibly thermochromic ink composition 8 for a writing utensil including at least: a reversibly thermochromic microencapsulated pigment including a reversibly thermochromic composition comprising (i) an electron-donating colorable organic compound, (ii) an electron-accepting compound, and (iii) a reaction medium which determines a temperature for inducing a coloring reaction of the former two, and water, wherein the average particle diameter of the reversibly thermochromic microencapsulated pigment is in a range of 0.1-0.49 μm and wherein the ratio of particles of 1.5 μm or larger is no more than 5 vol.% of the entire microencapsulated pigment. Also provided is a writing utensil 1 housing the same.

Description

  The present invention relates to an ink composition for a reversible thermochromic writing instrument and a writing instrument containing the ink composition.

Conventionally, there has been disclosed a reversible thermochromic writing instrument ink capable of forming a handwriting whose color tone changes with temperature change, and a writing instrument containing the ink (see, for example, Patent Document 1).
The handwriting formed by the writing instrument can change the reversible thermochromic material in the handwriting from colored to colorless with a body temperature such as touch, frictional heat generated by rubbing, a hair dryer, etc., and as a result, the handwriting can be erased. However, a cloudy afterimage (handwriting) is visually recognized at the location where the handwriting is erased.
The white turbid afterimage is difficult to see when the writing surface (paper) is white, but when written on a colored writing surface, the afterimage is remarkably visually recognized, which impairs practicality.
JP-A-7-186588

  The present invention is intended to solve the above-mentioned problems, that is, when the handwriting formed is erased not only on the white writing surface but also on the colored writing surface. An ink composition for a reversible thermochromic writing instrument in which a white cloudy afterimage is not visually recognized at a handwritten part and a writing instrument containing the ink composition are provided.

The present invention is intended to solve the problems of the above-described conventional ink composition for reversible thermochromic writing instruments and writing instruments containing the ink composition, that is, (i) an electron-donating color-forming organic compound, (B) an electron-accepting compound, (c) a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising a reaction medium that determines the temperature at which the color reaction of both occurs, and at least water. The reversible thermochromic microcapsule pigment has an average particle size in the range of 0.1 to 0.49 μm, and particles of 1.5 μm or more are 5% by volume or less in the total microcapsule pigment. A reversible thermochromic writing instrument ink composition is required.
Further, the reversible thermochromic microcapsule pigment has a complete decolorization temperature (t ₄ ) of 50 ° C. or higher and a complete color development temperature (t ₁ ) of 0 ° C. or lower with respect to the color density-temperature curve, Comprising a viscosity reducing agent, comprising a sugar mixture comprising 30% by mass or more of a starch saccharified product of 8 or more sugars and / or a reduced product thereof, and comprising a water-soluble polymer flocculant. It becomes a requirement to become.
Furthermore, a writing instrument in the form of a ballpoint pen or a marking pen containing the ink composition for a reversible thermochromic writing instrument is required.
Furthermore, it is required that the writing instrument is provided with a friction member, and that the friction member is an elastomer or a plastic foam.

  The present invention is rich in practicality showing good erasability of the handwriting without observing a cloudy afterimage when the handwriting formed by writing on the colored writing surface is erased. An ink composition for a reversible thermochromic writing instrument and a writing instrument containing the ink composition can be provided.

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

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

In addition, large hysteresis characteristics (ΔH _B = 8 to 80 ° C.) described in JP- _B -4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, and the like. ), That is, when the shape of the curve plotting the change in the color density due to the temperature change is lowering the temperature from the lower temperature side than the color changing temperature range, as opposed to increasing the temperature from the lower temperature side. In the specific temperature range, the color changes in a low temperature range below the complete color development temperature (t ₁ ) or the color erase state in the high temperature range above the complete color erase temperature (t ₄ ). A heat decoloring reversible thermochromic composition having color memory in the [temperature range between t _{2 and} t ₃ (substantially two-phase holding temperature range)] can also be applied (see FIG. 2).

The hysteresis characteristic in the color density-temperature curve of the reversible thermochromic composition will be described.
In FIG. 2, the vertical axis represents color density and the horizontal axis represents temperature. The change in color density due to the temperature change proceeds along the arrow. Here, A is a point indicating a density at a temperature t ₄ (hereinafter referred to as a complete decoloring temperature) that reaches a completely decolored state, and B is a temperature t ₃ (hereinafter referred to as a decoloring start temperature). C is a point indicating a density at a temperature t ₂ at which color development starts (hereinafter referred to as a color development start temperature), and D is a temperature t ₁ at which a complete color development state is reached (hereinafter referred to as a complete color development state). This is a point indicating a density at a color development temperature).
Discoloration temperature region is a temperature range between the t ₁ and t _4, 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 This is the actual color change 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 reversible thermochromic composition having a color-memory property, complete coloring temperature t ₁ the freezer compartment, below 0 ℃ only not be obtained by the temperature in a cold region or the like, friction complete decoloring temperature t ₄ By setting the temperature to 50 ° C. or higher, which is a temperature obtained from a familiar heating body such as heat or a hair dryer, the color can be effectively functioned to be maintained in a normal state (daily life temperature range).
The complete color developing temperature t ₁ is preferably −50 to 0 ° C., more preferably −50 to −5 ° C., and the complete color erasing temperature t ₄ is preferably 50 to 95 ° C., more preferably 55 to 95 ° C. .
If the complete color erasing temperature t ₄ is 50 ° C. or higher, the state before discoloration can be maintained even under high temperature conditions such as in summer, and if it is 95 ° C. or lower, the handwriting formed on the writing surface Can be sufficiently erased by frictional heat due to several rubbing by the friction member.
Complete decoloring If the temperature t ₄ is a temperature exceeding 95 ° C., since the frictional heat obtained by rubbing due to friction member is less likely to reach the complete decoloring temperature, easily becomes difficult to erase, or increased abrasion number, or Since the load tends to be excessively rubbed, the writing surface may be damaged.
Further, in the temperature setting of the complete coloring temperature t _1, is preferably a lower temperature to be maintained in the decolored state is normal use, is preferably 0 ℃ less.
Furthermore, it is necessary to make the reversible thermochromic composition filled in the writing instrument into a colored state. Therefore, it is necessary to cool the writing instrument, the ink composition, or the microcapsule pigment in advance to develop the reversible thermochromic composition.
As a cooling means in the production process, it is preferable to cool with a general-purpose freezer, but considering the cooling capacity of the freezer, the limit is up to −50 ° C.

Examples of the compounds (a), (b), and (c) of the reversible thermochromic composition are shown below.
Examples of the electron donating color-forming organic compound as component (a) of the present invention include diphenylmethane phthalides, phenyl indolyl phthalides, indolyl phthalides, diphenyl methane azaphthalides, and phenyl indolyl azaphthalides. , Fluorans, stylinoquinolines, diazarhodamine lactones and the like.
Examples of these compounds are given below.
3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide,
3- (4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide,
3,3-bis (1-n-butyl-2-methylindol-3-yl) phthalide,
3,3-bis (2-ethoxy-4-diethylaminophenyl) -4-azaphthalide,
3- [2-ethoxy-4- (N-ethylanilino) phenyl] -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide,
3,6-diphenylaminofluorane,
3,6-dimethoxyfluorane,
3,6-di-n-butoxyfluorane,
2-methyl-6- (N-ethyl-Np-tolylamino) fluorane,
3-chloro-6-cyclohexylaminofluorane,
2-methyl-6-cyclohexylaminofluorane,
2- (2-chloroanilino) -6-di-n-butylaminofluorane,
2- (3-trifluoromethylanilino) -6-diethylaminofluorane,
2- (N-methylanilino) -6- (N-ethyl-Np-tolylamino) fluorane,
1,3-dimethyl-6-diethylaminofluorane,
2-chloro-3-methyl-6-diethylaminofluorane,
2-anilino-3-methyl-6-diethylaminofluorane,
2-anilino-3-methyl-6-di-n-butylaminofluorane,
2-xylidino-3-methyl-6-diethylaminofluorane,
1,2-benz-6-diethylaminofluorane,
1,2-benz-6- (N-ethyl-N-isobutylamino) fluorane,
1,2-benz-6- (N-ethyl-N-isoamylamino) fluorane,
2- (3-methoxy-4-dodecoxystyryl) quinoline,
Spiro [5H- (1) benzopyrano (2,3-d) pyrimidine-5,1 '(3'H) isobenzofuran] -3'-one,
2- (diethylamino) -8- (diethylamino) -4-methyl-spiro [5H- (1) benzopyrano (2,3-g) pyrimidine-5,1 ′ (3′H) isobenzofuran] -3-one,
2- (Di-n-butylamino) -8- (di-n-butylamino) -4-methyl-spiro [5H- (1) benzopyrano (2,3-g) pyrimidine-5,1 '(3' H) Isobenzofuran] -3-one,
2- (Di-n-butylamino) -8- (diethylamino) -4-methyl-spiro [5H- (1) benzopyrano (2,3-g) pyrimidine-5,1 '(3'H) isobenzofuran] -3-one,
2- (Di-n-butylamino) -8- (N-ethyl-Ni-amylamino) -4-methyl-spiro [5H- (1) benzopyrano (2,3-g) pyrimidine-5,1 ' (3′H) isobenzofuran] -3-one,
3- (2-methoxy-4-dimethylaminophenyl) -3- (1-butyl-2-methylindol-3-yl) -4,5,6,7-tetrachlorophthalide,
3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4,5,6,7-tetrachlorophthalide,
3- (2-ethoxy-4-diethylaminophenyl) -3- (1-pentyl-2-methylindol-3-yl) -4,5,6,7-tetrachlorophthalide,
3 ′, 6′-bis [phenyl (2-methylphenyl) amino] -spiro [isobenzofuran-1 (3H), 9 ′-[9H] xanthen] -3-one,
3 ′, 6′-bis [phenyl (3-methylphenyl) amino] -spiro [isobenzofuran-1 (3H), 9 ′-[9H] xanthen] -3-one,
And 3 ', 6'-bis [phenyl (3-ethylphenyl) amino] -spiro [isobenzofuran-1 (3H), 9'-[9H] xanthen] -3-one.
Furthermore, there can be mentioned pyridine-based, quinazoline-based, bisquinazoline-based compounds and the like that are effective in developing fluorescent yellow to red color development.

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

Specific examples are given below.
Phenol, o-cresol, tertiary butylcatechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, n-butyl p-hydroxybenzoate N-octyl p-hydroxybenzoate, resorcin, dodecyl gallate, 2,2-bis (4-hydroxyphenyl) propane, 4,4-dihydroxydiphenylsulfone, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, 1-phenyl-1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4 -Hydroxyphenyl) -3-methylbu 1,1-bis (4-hydroxyphenyl) -2-methylpropane, 1,1-bis (4-hydroxyphenyl) n-hexane, 1,1-bis (4-hydroxyphenyl) n-heptane, , 1-bis (4-hydroxyphenyl) n-octane, 1,1-bis (4-hydroxyphenyl) n-nonane, 1,1-bis (4-hydroxyphenyl) n-decane, 1,1-bis ( 4-hydroxyphenyl) n-dodecane, 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, and ethers.
The component (c) is preferably a large hysteresis characteristic regarding the color density-temperature curve (a curve plotting a change in color density due to a temperature change changes the temperature from the low temperature side to the high temperature side and the high temperature side to the low temperature side). A carboxylic acid ester compound that exhibits a ΔT value (melting point-cloud point) of 5 ° C. or higher and lower than 50 ° C., which can form a reversible thermochromic composition that exhibits color memory, and changes color when changing to the side) For example, a carboxylic acid ester having a substituted aromatic ring in the molecule, an ester of a carboxylic acid having an unsubstituted aromatic ring and an aliphatic alcohol having 10 or more carbon atoms, a carboxylic acid ester having a cyclohexyl group in the molecule, 6 carbon atoms Fatty acid and unsubstituted aromatic alcohol or phenol ester, fatty acid having 8 or more carbon atoms and branched aliphatic alcohol or ester, dicarboxylic acid And esters of aromatic alcohol or branched aliphatic alcohol, dibenzyl cinnamate, heptyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, trilaurin, trimyristin, tristearin, Dimyristin, distearin and the like are used.

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

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

  As ethers, aliphatic ethers having a total carbon number of 10 or more are effective, and dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether, didecyl ether, diundecyl ether, didodecyl ether. , Ditridecyl ether, ditetradecyl ether, dipentadecyl ether, dihexadecyl ether, dioctadecyl ether, decane diol dimethyl ether, undecane diol dimethyl ether, dodecane diol dimethyl ether, tridecane diol dimethyl ether, decane diol diethyl ether, undecane diol diethyl ether Etc.

〔式中、Ｒ_１は水素原子又はメチル基を示し、ｍは０〜２の整数を示し、Ｘ_１、Ｘ_２のいずれか一方は−（ＣＨ_２）_ｎＯＣＯＲ_２又は−（ＣＨ_２）_ｎＣＯＯＲ_２、他方は水素原子を示し、ｎは０〜２の整数を示し、Ｒ_２は炭素数４以上のアルキル基又はアルケニル基を示し、Ｙ_１及びＹ_２は水素原子、炭素数１〜４のアルキル基、メトキシ基、又は、ハロゲンを示し、ｒ及びｐは１〜３の整数を示す。〕
前記式（１）で示される化合物のうち、Ｒ_１が水素原子の場合、より広いヒステリシス幅を有する可逆熱変色性組成物が得られるため好適であり、更にＲ_１が水素原子であり、且つ、ｍが０の場合がより好適である。
なお、式（１）で示される化合物のうち、より好ましくは下記一般式（２）で示される化合物が用いられる。

式中のＲは炭素数８以上のアルキル基又はアルケニル基を示すが、好ましくは炭素数１０〜２４のアルキル基、更に好ましくは炭素数１２〜２２のアルキル基である。
前記化合物として具体的には、オクタン酸−４−ベンジルオキシフェニルエチル、ノナン酸−４−ベンジルオキシフェニルエチル、デカン酸−４−ベンジルオキシフェニルエチル、ウンデカン酸−４−ベンジルオキシフェニルエチル、ドデカン酸−４−ベンジルオキシフェニルエチル、トリデカン酸−４−ベンジルオキシフェニルエチル、テトラデカン酸−４−ベンジルオキシフェニルエチル、ペンタデカン酸−４−ベンジルオキシフェニルエチル、ヘキサデカン酸−４−ベンジルオキシフェニルエチル、ヘプタデカン酸−４−ベンジルオキシフェニルエチル、オクタデカン酸−４−ベンジルオキシフェニルエチルを例示できる。 Furthermore, a compound represented by the following general formula (1) is preferably used as the component (c).

[Wherein, R ₁ represents a hydrogen atom or a methyl group, m represents an integer of 0 to 2, and _one of X ₁ and X ₂ represents — (CH ₂ ) _n OCOR ₂ or — (CH ₂ ) _n COOR ₂ , the other represents a hydrogen atom, n represents an integer of 0 to 2, R ₂ represents an alkyl or alkenyl group having 4 or more carbon atoms, Y ₁ and Y ₂ represent a hydrogen atom, 1 to 4 carbon atoms An alkyl group, a methoxy group, or halogen, and r and p each represent an integer of 1 to 3. ]
Among the compounds represented by the formula (1), when R ₁ is a hydrogen atom, it is preferable because a reversible thermochromic composition having a wider hysteresis width can be obtained, and R ₁ is a hydrogen atom, and , M is more preferably 0.
Of the compounds represented by the formula (1), a compound represented by the following general formula (2) is more preferably used.

R in the formula represents an alkyl group or alkenyl group having 8 or more carbon atoms, preferably an alkyl group having 10 to 24 carbon atoms, more preferably an alkyl group having 12 to 22 carbon atoms.
Specific examples of the compound include octanoic acid-4-benzyloxyphenylethyl, nonanoic acid-4-benzyloxyphenylethyl, decanoic acid-4-benzyloxyphenylethyl, undecanoic acid-4-benzyloxyphenylethyl, and dodecanoic acid. -4-benzyloxyphenylethyl, tridecanoic acid-4-benzyloxyphenylethyl, tetradecanoic acid-4-benzyloxyphenylethyl, pentadecanoic acid-4-benzyloxyphenylethyl, hexadecanoic acid-4-benzyloxyphenylethyl, heptadecanoic acid Examples thereof include -4-benzyloxyphenylethyl and octadecanoic acid-4-benzyloxyphenylethyl.

（式中、Ｒは炭素数８以上のアルキル基又はアルケニル基を示し、ｍ及びｎはそれぞれ１〜３の整数を示し、Ｘ及びＹはそれぞれ水素原子、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基、ハロゲンを示す。）
前記化合物として具体的には、オクタン酸１,１−ジフェニルメチル、ノナン酸１,１−ジフェニルメチル、デカン酸１,１−ジフェニルメチル、ウンデカン酸１,１−ジフェニルメチル、ドデカン酸１,１−ジフェニルメチル、トリデカン酸１,１−ジフェニルメチル、テトラデカン酸１,１−ジフェニルメチル、ペンタデカン酸１,１−ジフェニルメチル、ヘキサデカン酸１,１−ジフェニルメチル、ヘプタデカン酸１,１−ジフェニルメチル、オクタデカン酸１,１−ジフェニルメチルを例示できる。 Furthermore, a compound represented by the following general formula (3) can also be used as the component (c).

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

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

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

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

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

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

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

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

The reversible thermochromic microcapsule pigment can be blended in an amount of 15 to 50% by mass, preferably 20 to 45% by mass, and more preferably 25 to 40% by mass with respect to the total amount of the ink composition.
If it is less than 15% by mass, the color density is insufficient, and if it exceeds 50% by mass, the ink outflow is reduced and writing performance is impaired.

The solvent used in the ink may be only an organic solvent, but water and, if necessary, a water-soluble organic solvent are preferably used.
Examples of the water-soluble organic solvent include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, and ethylene glycol monomethyl. Ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, N-methyl-2- Pyrrolidone, or the like is used.

By adding a polymer flocculant in the ink, the flocculant causes a loose bridging action between the microcapsule pigment particles and exhibits a loose flocculent state. Ink showing such a loose agglomerated state is unlikely to cause separation of microcapsule pigments in the capillary space of an ink occlusion body (batting) made of a fiber bundling body and a marking pen body made of a resin bundle of fibers.
As the water-soluble polymer flocculant, a nonionic water-soluble polymer compound is used, and examples thereof include polyvinyl pyrrolidone, polyethylene oxide, and water-soluble polysaccharides.
Examples of the water-soluble polysaccharide include tragacanth gum, guar gum, pullulan, cyclodextrin, nonionic water-soluble cellulose derivatives and the like. Specific examples of nonionic water-soluble cellulose derivatives include methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxy Examples include ethyl methyl cellulose and hydroxypropyl methyl cellulose.

In addition, by adding a shear thinning agent to the ink, ink leakage from the gap between the ball and the tip can be prevented when the ballpoint pen that fills the ink is not used, or the writing tip is directed upward (upright state) ), It is possible to prevent the ink from flowing backward.
In addition, the viscosity of the ink composition to which the shear thinning agent is added shows an ink viscosity of 200 to 3000 mPa · s at a shear rate of 3.84S ⁻¹ by an E-type rotational viscometer at 20 ° C., and It is preferable that the shear thinning index is 0.1 to 0.6.
The shear thinning index (n) is expressed by an empirical formula T = Kj ⁿ (K is a non-Newtonian viscosity coefficient) obtained from rheological measurement by a viscometer such as a shear stress value (T) and a shear rate value (j). It is a value calculated by fitting.
Examples of the shear thinning agent include xanthan gum, welan gum, succinoglycan whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose (average molecular weight of about 1 to 8 million), alka gum, guar gum, diutane gum, Locust bean gum and its derivatives, 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, gelation extracted from seaweeds such as glucomannan, agar and carrageenan Thickening polysaccharide, 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 Nonionic surfactants having an HLB value of 8 to 12, such as Cole fatty acid ester, polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyoxyethylene alkyl phenyl ether, fatty acid amide, salts of dialkyl or dialkenylsulfosuccinic acid, N Examples thereof include a mixture of alkyl-2-pyrrolidone and an anionic surfactant, and a mixture of polyvinyl alcohol and an acrylic resin.

When the ink composition contains a sugar mixture containing 30% by mass or more of a starch saccharified product of 8 or more sugars and / or a reduced product thereof, the drying resistance can be improved and the dripping prevention performance can be improved. Can be granted.
As the sugar mixture, those containing 50% or more of saccharides having 8 or more sugars are preferably used, and more preferably those containing 70% or more of 8 or more sugars are used.
In order to impart dry resistance, it is necessary to form a dry film to some extent, but monosaccharides and disaccharides are not sufficient to form a dry film, so the effect on dry resistance is small and water absorption is high. When applied to a ballpoint pen, dripping is likely to occur when the tip is left facing down (inverted). In addition, in the case of about 3 to 7 sugars, the water absorption is lower than that of monosaccharides or disaccharides, but sufficient drying resistance cannot be obtained.
Furthermore, if a large amount of addition is attempted in order to obtain sufficient drying resistance, the water absorption increases and causes dripping, or the added sugar cannot be completely dissolved and the solid content in the ink increases, resulting in drying resistance. May decrease.
Since the saccharides have the characteristics that the hygroscopicity decreases as the molecular weight increases and a dry film is easily formed, the use of saccharides of 8 or more sugars can prevent drooping under high humidity and resistance to drying. Will also improve.
Furthermore, performances such as heat resistance, acid resistance, and microbial resistance are improved, and a stable state can be maintained in the ink.
As the saccharides having 8 or more sugars, a starch saccharified product obtained by enzymatic decomposition of starch or a reduced starch saccharified product obtained by reducing the terminal group of the starch saccharified product can be used.
Further, when starch is decomposed, saccharides having various degrees of polymerization are generated, and therefore it is technically difficult to completely isolate only saccharides having 8 or more sugars, and manufacturing costs are also increased. Therefore, in a sugar mixture containing 7 or less saccharides, the above performance can be sufficiently obtained in the ink by containing 30% by mass or more of the 8 or more saccharides, and is resistant to dripping and dripping prevention. Can be granted.
The said sugar mixture is mix | blended in 0.5-10.0 mass% with respect to the ink composition whole quantity, Preferably it is 1.0-8.0 mass%. If the amount is less than 0.5% by mass, it is difficult to obtain the effect of improving the drying resistance. If the amount is more than 10.0% by mass, the viscosity of the ink increases, which may cause crying or blurring, and hinder followability. There is. Furthermore, drying resistance may be deteriorated.

  Further, when the ink is incorporated in a ballpoint pen for practical use, 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 triesters such as thiophosphite triester (alkoxycarbonylethyl ester), 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 phosphoric acid diesters or their metal salts, ammonium salts, amine salts, alkanolamine salts, etc. to give the ball seat wear-preventing effect.

In addition, benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, saponin and other rust preventives, coalic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, dehydro as necessary Preservatives or antifungal agents such as sodium acetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, urea, nonionic surfactants, reduced or non- Reduced starch hydrolyzate, oligosaccharides such as trehalose, sucrose, cyclodextrin, glucose, dextrin, sorbit, mannitol, sodium pyrophosphate, etc. wetting agents, antifoaming agents, dispersants, fluorine that improves ink permeability Surfactants and noni The emissions-based surfactant may be used.
If necessary, acrylic resin, styrene maleic acid copolymer resin, polyvinyl pyrrolidone, polyvinyl alcohol, dextrin and the like can be used for fixing to the paper surface and imparting viscosity.

The ink composition is put to practical use by filling a writing instrument such as a marking pen, a ballpoint pen, or a brush pen with a tip attached to a writing tip.
When filling the marking pen, the structure and shape of the marking pen itself are not particularly limited. For example, a marking pen tip such as a fiber tip, a felt tip, or a plastic tip is attached to the writing tip and the inside of the shaft tube. A structure in which ink is impregnated into a stored fiber bundle and ink is supplied to the writing tip, ink is stored directly in the shaft cylinder, and ink flow adjustment member or fiber bundle made up of fiber bundle A marking pen with a structure that supplies a predetermined amount of ink to the writing tip through an adjusting member, a marking pen that contains ink directly inside the shaft cylinder, and supplies a predetermined amount of ink to the writing tip by a valve mechanism It is done.
When filling the ballpoint pen, the structure and shape of the ballpoint pen itself are not particularly limited.For example, the ink occlusion body composed of a bundle of fibers accommodated in the shaft tube is impregnated with ink, and the writing tip portion attached with the ballpoint pen tip is used. A structure for supplying ink, a structure in which ink is directly stored in the shaft cylinder, and a predetermined amount of ink is supplied to the writing tip portion via an ink flow rate adjusting member composed of a comb groove-shaped ink flow rate adjusting member or a fiber bundle, A ball pen having a structure in which an ink storage tube filled with ink is provided in the shaft cylinder, the ink storage tube communicates with a ballpoint pen tip, and a liquid stopper for backflow prevention is provided on the end surface of the ink. .

The ballpoint pen tip is a ball holder formed by cutting with a tip holding a ball in a ball holding portion formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, a metal material drill or the like. Examples include a chip holding a ball in the holding portion, a chip holding a ball by providing a resin ball receiving seat inside a metal or plastic molded body, and the like.
The tip may be configured to bias the ball forward by a spring body.
The ball may be about 0.1 to 3.0 mm in diameter, such as cemented carbide, stainless steel, ruby, ceramic, resin, rubber, etc., preferably 0.3 to 1.5 mm, more preferably 0. 3 to 1.0 mm are used.

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.
The ball-point pen tip and the ink containing tube are fitted directly or via a connecting member, and a ball-point pen refill is formed by filling the ink composition and, if necessary, the ink backflow prevention body composition.

The ink backflow prevention body composition is composed of a non-volatile liquid or a hardly volatile liquid.
Specifically, petroleum jelly, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or co-oligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, Examples thereof include polyether-modified silicone oil and fatty acid-modified silicone oil, and one or more can be used in combination.
It is preferable to add a gelling agent to the nonvolatile liquid and / or the hardly volatile liquid to increase the viscosity to a suitable viscosity. The surface of the silica is hydrophobized, the surface is methylated fine particle silica, and aluminum silicate. , Swellable mica, hydrophobic thickeners such as bentonite and montmorillonite, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, tribenzylidene sorbitol, fatty acid amide, amide modified Examples include dextrin compounds such as polyethylene wax, hydrogenated castor oil, fatty acid dextrin, and cellulose compounds.
Furthermore, the liquid ink backflow prevention body composition and a solid backflow prevention body can be used in combination.

The tip of the ballpoint pen tip can be fixed with a resin film for preventing the tip of the tip from drying, and the tip of the tip of the ball, the ball holding portion, and the gap between the ball and the ball holding portion are fixed. As a result, it is possible to prevent the tip of the tip from drying and volatilization of the medium in the ink.
As the resin for forming the resin film, a thermoplastic resin, a thermosetting resin, or an ultraviolet curable resin is used.

The ballpoint pen refill can be accommodated in a shaft tube to obtain a cap-type ballpoint pen.
Further, the ballpoint pen refill can be accommodated in a shaft cylinder to obtain a retractable ballpoint pen. The ballpoint pen refill is stored in the shaft cylinder with the tip exposed to the outside air, and the operation of the retracting mechanism is performed. Thus, the writing tip protrudes from the shaft tube opening.
Examples of the appearance mechanism include a knock type, a rotary type, and a slide type.
The knock type has a knock portion on the rear end portion of the shaft tube and the side surface of the shaft tube, and by pressing the knock portion, the writing tip portion of the ballpoint pen refill is projected and retracted from the front end opening portion of the shaft tube, or on the shaft tube. The structure which makes the writing tip part of a ball-point pen refill appear and disappear from the axial cylinder front-end opening part by pressing the provided clip part can be illustrated.
The rotary type has a rotating part at the rear part of the shaft cylinder, and can be exemplified by a configuration in which the writing tip part of the ballpoint pen refill is projected and retracted from the front end part of the shaft cylinder by turning the rotating part.
The slide type has a slide part on the side surface of the shaft cylinder, and the sliding tip of the writing point of the ballpoint pen refill is projected and retracted from the front end opening of the shaft cylinder by operating the slide, or the clip part provided on the shaft cylinder is slid. By doing so, it is possible to exemplify a configuration in which the writing tip portion of the ballpoint pen refill is projected and retracted from the opening at the front end of the shaft cylinder.
The retractable ballpoint pen is a compound type retractable ballpoint pen in which a plurality of ballpoint pen refills are accommodated in a shaft cylinder, and the writing tip of one of the ballpoint pen refills protrudes and retracts from the opening at the front end of the shaft cylinder by the operation of the retractable mechanism. May be.

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

Examples of the present invention are shown below, but the present invention is not limited thereto.
In addition, the part in an Example is a mass part.
Preparation of reversible thermochromic microcapsule pigment A (a) 2.5 parts of 1,3-dimethyl-6-diethylaminofluorane as component, and 2,2-bis (4′-hydroxyphenyl) hexafluoro as component (b) It has color memory consisting of 5.0 parts of propane, 3.0 parts of 1,1-bis (4′-hydroxyphenyl) n-decane and 50.0 parts of 4-benzyloxyphenylethyl caprate as component (c). A reversible thermochromic composition is dissolved by heating, and a solution in which 30.0 parts of an aromatic isocyanate prepolymer and 40.0 parts of a co-solvent are mixed as a wall film material in an aqueous 8% polyvinyl alcohol solution has an average particle size. The dispersion conditions were adjusted to about 1.2 μm, emulsified and dispersed, and after stirring while warming, 2.5 parts of a water-soluble aliphatic modified amine was added, and stirring was continued to achieve reversible heat. It was obtained dichroism microcapsule pigment suspension.
The suspension was centrifuged to isolate a reversible thermochromic microcapsule pigment.
The microcapsule pigment (T ₁ : −35 ° C., T ₂ : −15 ° C., T ₃ : 45 ° C., T ₄ : 64 ° C.) changes its color from orange to colorless, and the average particle size is 1.0 μm. Particles exceeding 1.5 μm were 26% by volume in the total microcapsule pigment.

Preparation of reversible thermochromic microcapsule pigment B (a) 2.5 parts of 1,3-dimethyl-6-diethylaminofluorane as component, and 2,2-bis (4'-hydroxyphenyl) hexafluoro as component (b) It has color memory consisting of 5.0 parts of propane, 3.0 parts of 1,1-bis (4′-hydroxyphenyl) n-decane and 50.0 parts of 4-benzyloxyphenylethyl caprate as component (c). A reversible thermochromic composition is dissolved by heating, and a solution in which 30.0 parts of an aromatic isocyanate prepolymer and 40.0 parts of a co-solvent are mixed as a wall film material in an aqueous 8% polyvinyl alcohol solution has an average particle size. The dispersion condition was adjusted to about 0.9 μm, emulsified and dispersed. After stirring while warming, 2.5 parts of a water-soluble aliphatic modified amine was added, and stirring was continued to achieve reversible heat. It was obtained dichroism microcapsule pigment suspension.
The suspension was centrifuged to isolate a reversible thermochromic microcapsule pigment.
The microcapsule pigment (T ₁ : −40 ° C., T ₂ : −18 ° C., T ₃ : 45 ° C., T ₄ : 64 ° C.) changes its color from orange to colorless, and the average particle size is 0.8 μm. Particles exceeding 1.5 μm were 11% by volume in the total microcapsule pigment.

Preparation of reversible thermochromic microcapsule pigment C (a) 2.5 parts of 1,3-dimethyl-6-diethylaminofluorane as component (2) 2,2-bis (4'-hydroxyphenyl) hexafluoro as component (b) It has color memory consisting of 5.0 parts of propane, 3.0 parts of 1,1-bis (4′-hydroxyphenyl) n-decane and 50.0 parts of 4-benzyloxyphenylethyl caprate as component (c). A reversible thermochromic composition is dissolved by heating, and a solution in which 30.0 parts of an aromatic isocyanate prepolymer and 40.0 parts of a co-solvent are mixed as a wall film material in an aqueous 8% polyvinyl alcohol solution has an average particle size. Emulsified and dispersed by adjusting the dispersion conditions so as to be about 0.7 μm. After stirring while heating, 2.5 parts of a water-soluble aliphatic modified amine was added, and further stirring was continued for reversible heat. It was obtained dichroism microcapsule pigment suspension.
The suspension was centrifuged to isolate a reversible thermochromic microcapsule pigment.
The microcapsule pigment (T ₁ : −40 ° C., T ₂ : −18 ° C., T ₃ : 45 ° C., T ₄ : 64 ° C.) changes its color from orange to colorless, and the average particle size is 0.65 μm. Particles exceeding 1.5 μm were 7% by volume in the total microcapsule pigment.

Preparation of reversible thermochromic microcapsule pigment D (a) 2.5 parts of 1,3-dimethyl-6-diethylaminofluorane as component and 2,2-bis (4'-hydroxyphenyl) hexafluoro as component (b) It has color memory consisting of 5.0 parts of propane, 3.0 parts of 1,1-bis (4′-hydroxyphenyl) n-decane and 50.0 parts of 4-benzyloxyphenylethyl caprate as component (c). A reversible thermochromic composition is dissolved by heating, and a solution in which 30.0 parts of an aromatic isocyanate prepolymer and 40.0 parts of a co-solvent are mixed as a wall film material in an aqueous 8% polyvinyl alcohol solution has an average particle size. Emulsified and dispersed by adjusting the dispersion conditions so as to be about 0.5 μm. After stirring while heating, 2.5 parts of a water-soluble aliphatic modified amine was added, and further stirring was continued for reversible heat. It was obtained dichroism microcapsule pigment suspension.
The suspension was centrifuged to isolate a reversible thermochromic microcapsule pigment.
The microcapsule pigment (T ₁ : −40 ° C., T ₂ : −20 ° C., T ₃ : 45 ° C., T ₄ : 64 ° C.) changes its color from orange to colorless, and the average particle size is 0.45 μm. Particles exceeding 1.5 μm were 2% by volume in the total microcapsule pigment.

Preparation of reversible thermochromic microcapsule pigment E (i) 2.5 parts of 1,3-dimethyl-6-diethylaminofluorane as component (2) 2,2-bis (4'-hydroxyphenyl) hexafluoro as component (b) It has color memory consisting of 5.0 parts of propane, 3.0 parts of 1,1-bis (4′-hydroxyphenyl) n-decane and 50.0 parts of 4-benzyloxyphenylethyl caprate as component (c). A reversible thermochromic composition is dissolved by heating, and a solution in which 30.0 parts of an aromatic isocyanate prepolymer and 40.0 parts of a co-solvent are mixed as a wall film material in an aqueous 8% polyvinyl alcohol solution has an average particle size. The dispersion conditions were adjusted to about 2.3 μm, emulsified and dispersed, and stirring was continued while warming. Then, 2.5 parts of a water-soluble aliphatic modified amine was added, and stirring was continued to achieve reversible heat. It was obtained dichroism microcapsule pigment suspension.
The suspension was centrifuged to isolate a reversible thermochromic microcapsule pigment.
The microcapsule pigment (T ₁ : −18 ° C., T ₂ : −9 ° C., T ₃ : 45 ° C., T ₄ : 64 ° C.) changes its color from orange to colorless, and the average particle size is 2.0 μm. Particles exceeding 1.5 μm were 70% by volume in the total microcapsule pigment.

Preparation of reversible thermochromic microcapsule pigment F (i) 2.5 parts of 1,3-dimethyl-6-diethylaminofluorane as component and 2,2-bis (4'-hydroxyphenyl) hexafluoro as component (b) It has color memory consisting of 5.0 parts of propane, 3.0 parts of 1,1-bis (4′-hydroxyphenyl) n-decane and 50.0 parts of 4-benzyloxyphenylethyl caprate as component (c). A reversible thermochromic composition is dissolved by heating, and a solution in which 30.0 parts of an aromatic isocyanate prepolymer and 40.0 parts of a co-solvent are mixed as a wall film material in an aqueous 8% polyvinyl alcohol solution has an average particle size. The dispersion conditions were adjusted to about 1.5 μm, emulsified and dispersed. After stirring while warming, 2.5 parts of a water-soluble aliphatic modified amine was added, and stirring was continued to achieve reversible heat. It was obtained dichroism microcapsule pigment suspension.
The suspension was centrifuged to isolate a reversible thermochromic microcapsule pigment.
The microcapsule pigment (T ₁ : −20 ° C., T ₂ : −10 ° C., T ₃ : 45 ° C., T ₄ : 64 ° C.) changes its color from orange to colorless, and the average particle size is 1.3 μm. Particles exceeding 1.5 μm were 35% by volume in the total microcapsule pigment.

Preparation of reversible thermochromic microcapsule pigment G (i) 4,5,6,7-tetrachloro-3- [4- (diethylamino) -2-methylphenyl] -3- (1-ethyl-2-) as component Methyl-1H-indol-3-yl) -1 (3H) -isobenzofuranone 2.0 parts, 2,2-bis (4′-hydroxyphenyl) hexafluoropropane 5.0 parts, 1,1-bis ( 4'-hydroxyphenyl) n-decane 3.0 parts, and (c) a reversible thermochromic composition having color memory consisting of 50.0 parts of 4-benzyloxyphenylethyl caprate as a component, Dispersion conditions of a solution prepared by mixing 30.0 parts of an aromatic isocyanate prepolymer and 40.0 parts of a co-solvent as a wall film material in an 8% aqueous polyvinyl alcohol solution are adjusted so that the average particle size is about 0.5 μm. Emulsification and dispersed in integer, Stirring was continued while warming, added 2.5 parts of a water-soluble aliphatic modified amine to give the reversible thermal discoloration microcapsule pigment suspension further continued agitation.
The suspension was centrifuged to isolate a reversible thermochromic microcapsule pigment.
The microcapsule pigment (T ₁ : −40 ° C., T ₂ : −20 ° C., T ₃ : 45 ° C., T ₄ : 64 ° C.) changes color from blue to colorless, and the average particle size is 0.45 μm. Particles exceeding 1.5 μm were 3% by volume in the total microcapsule pigment.

Reference example 1
Preparation of ink composition for reversible thermochromic writing instrument Microcapsule pigment A 25.0 parts, succinoglycan (shear thinning agent) 0.3 parts, urea 10.0 parts, glycerin 10.0 parts, phosphate ester 0.5 part of a surfactant, 0.6 part of a nonionic permeability imparting agent, 0.1 part of a modified silicone antifoaming agent, 0.1 part of an antifungal agent, 0.5 part of triethanolamine, water 47. An ink composition for reversible thermochromic writing instruments consisting of 5 parts was prepared.

Writing instrument production (see Fig. 4)
A 0.5 mm stainless steel ball was connected to the tip 3 held at the tip of the ink containing tube 11 made of polypropylene resin via the connecting member 5.
The ink composition 8 is filled into the ink containing tube, then the ink backflow prevention body 12 (liquid stopper) is filled at the rear end of the ink, and the tail plug 13 is fitted to the rear part of the ink containing tube to form the refill 14. Obtained.
Further, the refill is incorporated in a shaft cylinder (comprised of a front shaft cylinder 41 and a rear shaft cylinder 42), and a cap 6 having a rubber seal 15 is fitted therein. )
The rear barrel is provided with SEBS rubber as the friction member 7.

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Reference example 2
Preparation of ink composition for reversible thermochromic writing instrument 25.0 parts of microcapsule pigment B, 0.3 part of succinoglycan (shear thinning agent), 10.0 parts of urea, 10.0 parts of glycerin, phosphate ester 0.5 part of a surfactant, 0.6 part of a nonionic permeability imparting agent, 0.1 part of a modified silicone antifoaming agent, 0.1 part of an antifungal agent, 0.5 part of triethanolamine, water 47. An ink composition for reversible thermochromic writing instruments consisting of 5 parts was prepared.

Writing instrument production (see Fig. 5)
The ink composition 8 is filled in a polypropylene shaft cylinder 4 having an inner diameter of 5 mm and an outer diameter of 9 mm, to which a ballpoint pen tip 3 is fixed through a connecting member 5, and then has a viscoelasticity whose main component is polybutene and has an ink backflow prevention body having viscoelasticity. 12 and the tail plug 13 was fitted to the rear portion of the shaft tube.
Further, a rubber seal 15 was incorporated, and a cap 6 having a friction member 7 made of SEBS resin was fitted to the tip, and then a deaeration process was performed by a centrifugal process to obtain a writing instrument 1 (ballpoint pen).
The ballpoint pen tip has a 0.7 mm diameter stainless steel ball held in a ball holding portion formed by cutting a metal material with a drill, and the ball is biased forward by a spring body. It is a thing.

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Reference example 3
Preparation of ink composition for reversible thermochromic writing instrument 25.0 parts of the microcapsule pigment B, 0.3 part of succinoglycan (shear thinning agent), sugar mixture [manufactured by Sanwa Starch Co., Ltd., trade name: Sandeck 30] reversible thermochromic writing instrument ink comprising 3.0 parts, phosphate ester surfactant 0.5 part, antifungal agent 0.1 part, triethanolamine 1.0 part, water 70.1 part A composition was prepared.

Writing instrument production (see Fig. 6)
A ball holding portion formed by sucking and filling the ink composition 8 into the ink containing tube 11 made of polypropylene resin, and pressing and deforming the vicinity of the tip of the metal pipe inward from the outer surface via the resin connection member 5 And a ballpoint pen tip 3 holding a stainless steel ball having a diameter of 0.7 mm.
Next, an ink backflow preventer (liquid stopper) was filled from the rear end of the polypropylene pipe, and a tail plug was fitted to the rear part of the pipe to obtain a ballpoint refill.
The ball-point pen refill was incorporated into the shaft cylinder 4 to obtain a retractable writing instrument 1 (ballpoint pen).
The writing instrument is housed in the shaft cylinder in a state where the tip provided on the ballpoint pen refill is exposed to the outside air, and the shaft cylinder is activated by the operation of the retracting mechanism (knock mechanism) provided at the rear end of the shaft cylinder. The chip protrudes from the front end opening.
In addition, a friction member 7 made of SEBS resin is provided around the shaft tip end opening.

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Reference example 4
Preparation of reversible thermochromic writing ink composition ink composition 25.0 parts, 20.0 parts of microcapsule pigment C, 0.3 part of succinoglycan (shear thinning agent), sugar mixture [Sanwa Starch Co., Ltd. Product name: Sandek 70] 3.0 parts, 0.5 parts phosphate surfactant, 0.1 part antifungal agent, 1.0 part triethanolamine, 70.1 parts water An ink composition for a thermochromic writing instrument was prepared.

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

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 1
Preparation of ink composition for reversible thermochromic writing instrument 25.0 parts of the microcapsule pigment D, 20.0 parts of succinoglycan (shear thinning agent), sugar mixture [Sanwa Starch Co., Ltd. Product name: Sandeck 30] 3.0 parts, phosphate ester surfactant 0.5 part, antifungal agent 0.1 part, triethanolamine 1.0 part, water 70.1 parts reversible heat An ink composition for a color-changing writing instrument was prepared.

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

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Reference Example 5
Preparation of ink composition for reversible thermochromic writing instrument 20.0 parts of the above microcapsule pigment B, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], 18.0 parts of glycerin, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

Writing instrument production (see Fig. 9)
The ink composition 2 is impregnated with a polyester sliver covered with a synthetic resin film, impregnated with the ink composition, accommodated in a shaft cylinder 4 made of polypropylene resin, and made of polyester fiber at the tip of the shaft cylinder via a connecting member 5. The marking pen tip 3 (cannonball type) was assembled in a connected state, and the cap 6 was attached to obtain a writing instrument 1 (marking pen).
SEBS resin is provided as a friction member 7 at the rear end of the shaft tube.

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Reference Example 6
Preparation of ink composition for reversible thermochromic writing instrument The microcapsule pigment C20.0 parts, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cello size WP-09L], glycerin 18.0 parts, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

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

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 2
Preparation of ink composition for reversible thermochromic writing instrument 20.0 parts of the above microcapsule pigment D, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], 18.0 parts of glycerin, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

Writing instrument production (see Fig. 11)
The ink composition 8 is directly accommodated in the shaft cylinder 4, has a comb groove-shaped ink adjustment member 16 in the front of the shaft cylinder, and is deformed by pressing the vicinity of the tip of a metal pipe inward from the outer surface. A ballpoint pen tip 3 in which a tip made of a cemented carbide alloy having a diameter of 0.5 mm is held is fitted through a connecting member 5 to obtain a writing instrument 1 (ballpoint pen).
The writing instrument is provided with a detachable cap (not shown), and a friction member 7 is provided at the rear end of the shaft tube.

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 3
Preparation of ink composition for reversible thermochromic writing instrument 20.0 parts of the above microcapsule pigment D, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], 18.0 parts of glycerin, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

Writing instrument production (see Figure 12)
The ink composition 8 is directly accommodated in the shaft cylinder 4, has a comb groove-shaped ink adjustment member 16 in front of the shaft cylinder, and the marking pen tip 3 (chisel type) is connected via the connection member 5. The writing instrument 1 (marking pen) was obtained by fitting.
The writing instrument is provided with a detachable cap (not shown), and a friction member 7 is provided at the rear end of the shaft tube.

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 4
Preparation of ink composition for reversible thermochromic writing instrument 20.0 parts of the above microcapsule pigment D, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], 18.0 parts of glycerin, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

Writing instrument production (see Fig. 13)
The marking pen tip 3, the ink occluding body 2 connected to the rear end of the tip, the intermediate member 17 disposed behind the ink occluding member, and the removable ink tank 18 disposed behind the intermediate member. (An ink cartridge in which the ink composition 8 is sealed by the plug 181 before use), the shaft cylinder 4, and the tail plug 13 including the friction member 7 that is detachably screwed into the rear end opening of the shaft cylinder. And the writing instrument 1 (marking pen) which consists of a cap 9 was obtained.
The intermediate member includes a partition that partitions the ink storage body and the ink tank, and a plurality of (specifically, two) communication pipes that are pierced and connected to the inside of the ink storage body protruding from the partition. And a connecting pipe inserted into the ink tank protruding from the partition wall.

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 5
Preparation of ink composition for reversible thermochromic writing instrument 20.0 parts of the above microcapsule pigment D, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], 18.0 parts of glycerin, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

Writing instrument production (see Fig. 14)
The ink composition was impregnated in the ink occlusion body 2 in which a polyester sliver was coated with a synthetic resin film.
The ink occlusion body 2 is accommodated in a shaft cylinder 4 made of polypropylene resin having a marking pen tip 3 (cannonball type) made of polyester fiber attached to one end, and a marking pen tip 3 (chisel type) made of polyester fiber is attached. The connecting member 5 was fitted to the shaft cylinder at the other end, and a cap 6 was attached to each pen tip to obtain a double-headed writing instrument 1 (marking pen).
Each pen tip has a different size, and a friction member 7 made of SEBS resin is provided on the top of one cap.

Characters (handwriting) were formed by writing on light blue paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when it was rubbed with a friction member attached to the shaft tube, the characters were decolored, and a cloudy afterimage was not visually recognized at the writing location.

Example 6
Preparation of ink composition for reversible thermochromic writing instrument 20.0 parts of the above microcapsule pigment D, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], 18.0 parts of glycerin, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

Writing instrument production (see Figure 15)
The ink composition 2 impregnated with a polyester resin sliver covered with a synthetic resin film is impregnated with the ink composition, accommodated in a shaft cylinder 4 made of polypropylene resin, and made of polyester fiber at the tip of the shaft cylinder via a connecting member 5. The marking pen tip 3 (chisel type) was assembled in the connected state, and the cap 6 was attached to obtain the writing instrument 1 (marking pen).
The cap is an elastomer made of a polyester resin and serves also as a friction member.

A letter (handwriting) was formed by writing on light yellow paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when it was rubbed at the top of the cap, the characters were erased and no cloudy afterimage was visually recognized at the writing site.

Example 7
Preparation of ink composition for reversible thermochromic writing instrument 20.0 parts of the above microcapsule pigment D, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], 18.0 parts of glycerin, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

Writing instrument production (see Fig. 16)
The ink composition 8 and the stirrer 9 (SUS-304 ferritic stainless steel ball, diameter 3 mm) are built in the shaft cylinder 4, and the marking pen tip 3 (chisel type) is attached to the tip via the connecting member 5. The writing instrument 1 (marking pen) was obtained by attaching and attaching the cap 6.
A valve mechanism 10 is provided in the shaft cylinder, and the valve mechanism includes a valve seat, a valve body, and a metal spring that urges the valve body to press against the valve seat. The valve opens with the pressure applied to the pen body at the time.
The cap is an elastomer made of a polyester resin and serves also as a friction member.

A letter (handwriting) was formed by writing on gray paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when it was rubbed at the top of the cap, the characters were erased and no cloudy afterimage was visually recognized at the writing site.

Example 8
Preparation of ink composition for reversible thermochromic writing instrument 20.0 parts of the above microcapsule pigment D, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], 18.0 parts of glycerin, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

Writing instrument production (see Figure 17)
The ink composition 8 was accommodated in an ink tank 18 (an ink cartridge in which the ink composition was sealed by a plug 181 before use).
The front shaft cylinder 41 has a comb groove-shaped ink adjusting member 16, and the marking pen tip 3 (chisel type) is fitted through the connecting member 5, and the intermediate member 17 is fitted to the rear portion of the ink adjusting member. did.
Next, a cartridge was mounted on the intermediate member, and the rear barrel 42 was screwed to obtain a writing instrument 1 (marking pen).
The writing instrument is provided with a cap 6 made of a polyester resin and also serves as a friction member.

A letter (handwriting) was formed by writing on light green paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when it was rubbed at the top of the cap, the characters were erased, and no cloudy afterimage was visually recognized at the writing location.

Example 9
Preparation of ink composition for reversible thermochromic writing instrument 20.0 parts of the above microcapsule pigment D, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], 18.0 parts of glycerin, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

Writing instrument production (see Figure 18)
The marking pen tip 3, the ink occluding body 2 connected to the rear end of the tip, the intermediate member 17 disposed behind the ink occluding member, and the removable ink tank 18 disposed behind the intermediate member. (An ink cartridge in which the ink composition 8 is sealed by the plug 181 before use), the shaft cylinder 4, the tail plug 13 detachably screwed into the rear end opening of the shaft cylinder, and the cap 9 Writing instrument 1 (marking pen) was obtained.
The intermediate member includes a partition that partitions the ink storage body and the ink tank, and a plurality of (specifically, two) communication pipes that are pierced and connected to the inside of the ink storage body protruding from the partition. The connecting pipe is inserted into the ink tank protruding from the partition wall, and the cap is made of polyester resin and also serves as a friction member.

Characters (handwriting) were formed by writing on light blue paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when it was rubbed at the top of the cap, the characters were erased, and no cloudy afterimage was visually recognized at the writing location.

Example 10
Preparation of ink composition for reversible thermochromic writing instrument 20.0 parts of the above microcapsule pigment D, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], 18.0 parts of glycerin, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

Writing instrument production (see Figure 19)
The ink composition 8 was incorporated in the shaft cylinder 4, the tip 3 made of a brush tip was attached to the tip, and the cap 6 was attached to obtain a writing instrument 1 (brush pen).
A valve mechanism 10 is provided in the shaft cylinder, and the valve mechanism includes a valve seat, a valve body, and a metal spring that biases the valve body so as to press the valve body against the valve seat. The valve opens by pressing the operating mechanism at the rear end of the cylinder.
The cap is an elastomer made of a polyester resin and serves also as a friction member.

A letter (handwriting) was formed by writing on light yellow paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 11
Preparation of ink composition for reversible thermochromic writing instrument 20.0 parts of the above microcapsule pigment D, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], 18.0 parts of glycerin, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 0.1 part of 10% diluted phosphoric acid solution and 59.88 parts of water and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

Writing instrument production (see Figure 20)
The ink composition 2 impregnated with a polyester resin sliver covered with a synthetic resin film is impregnated with the ink composition, accommodated in a shaft cylinder 4 made of polypropylene resin, and made of polyester fiber at the tip of the shaft cylinder via a connecting member 5. The marking pen tip 3 (chisel type) was assembled in the connected state, and the cap 6 was attached to obtain the writing instrument 1 (marking pen).
The marking pen tip includes a transparent member 31 at the center.
The cap is an elastomer made of a polyester resin and serves also as a friction member.

A letter (handwriting) was formed by writing on gray paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when it was rubbed at the top of the cap, the characters were erased and no cloudy afterimage was visually recognized at the writing site.

Example 12
Preparation of ink composition for reversible thermochromic writing instrument 25.0 parts of the microcapsule pigment D, 0.3 part of succinoglycan (shear thinning agent), sugar mixture [manufactured by Sanwa Starch Co., Ltd., trade name: Sandeck 30] reversible thermochromic writing instrument ink comprising 3.0 parts, phosphate ester surfactant 0.5 part, antifungal agent 0.1 part, triethanolamine 1.0 part, water 70.1 part A composition was prepared.
25.0 parts of the above microcapsule pigment G, 0.3 part of succinoglycan (shear thinning agent), sugar mixture [manufactured by Sanwa Starch Co., Ltd., trade name: Sandeck 30], 3.0 parts, phosphate ester An ink composition for a reversible thermochromic writing instrument comprising 0.5 part of a surfactant, 0.1 part of an antifungal agent, 1.0 part of triethanolamine and 70.1 parts of water was prepared.

Preparation of ball-point pen refill Each ink composition 8 is sucked and filled into an ink containing tube 11 made of polypropylene resin, and is formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface through a resin connection member 5. The ball holding part was connected to a ballpoint pen tip 3 holding a stainless steel ball having a diameter of 0.5 mm.
Next, an ink backflow preventer (liquid stopper) was filled from the rear end of the polypropylene pipe, and a tail plug was fitted to the rear part of the pipe to obtain a ballpoint refill.

Writing instrument production (see Figure 21)
Fabrication of compound ballpoint pen (see Fig. 21)
The two composite ballpoint pen refills obtained as described above are incorporated in a light shielding (opaque) shaft cylinder 4 (diameter 11 mm), and the writing tip of one of the ballpoint pen refills is a shaft cylinder by the operation of the retracting mechanism. A writing instrument 1 (composite ballpoint pen) that appears and disappears from the front end opening was obtained.
A friction member 10 made of SEBS resin is provided at the rear end of the shaft of the composite ballpoint pen.

A letter (handwriting) was formed by writing on light green paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Example 13
Preparation of ink composition for reversible thermochromic writing instrument 25.0 parts of the microcapsule pigment D, 0.3 part of succinoglycan (shear thinning agent), sugar mixture [manufactured by Sanwa Starch Co., Ltd., trade name: Sandeck 30] reversible thermochromic writing instrument ink comprising 3.0 parts, phosphate ester surfactant 0.5 part, antifungal agent 0.1 part, triethanolamine 1.0 part, water 70.1 part A composition was prepared.
25.0 parts of the above microcapsule pigment G, 0.3 part of succinoglycan (shear thinning agent), sugar mixture [manufactured by Sanwa Starch Co., Ltd., trade name: Sandeck 30], 3.0 parts, phosphate ester An ink composition for a reversible thermochromic writing instrument comprising 0.5 part of a surfactant, 0.1 part of an antifungal agent, 1.0 part of triethanolamine and 70.1 parts of water was prepared.

Preparation of ball-point pen refill Each ink composition 8 is sucked and filled into an ink containing tube 11 made of polypropylene resin, and is formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface through a resin connection member 5. The ball holding portion was connected to a ballpoint pen tip 3 holding a stainless steel ball having a diameter of 0.4 mm.
Next, an ink backflow preventer (liquid stopper) was filled from the rear end of the polypropylene pipe, and a tail plug was fitted to the rear part of the pipe to obtain a ballpoint refill.

Writing instrument production (see Figure 21)
The two ballpoint pen refills obtained as described above are incorporated into a transparent shaft cylinder 4 (diameter 11 mm) having a lid 19 that can be opened and closed at the rear, and after the lid is closed, either of them is operated by the operation of the retracting mechanism. A writing instrument 1 (composite ballpoint pen) was obtained in which the writing tip of the ballpoint pen refill protruded from the opening at the front end of the barrel.
A friction member 10 made of SEBS resin is provided in the vicinity of the opening at the tip of the shaft cylinder.

A letter (handwriting) was formed by writing on gray paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Reference Example 7
Preparation of ink composition for reversible thermochromic writing instrument 25.0 parts of the microcapsule pigment B, 0.3 part of succinoglycan (shear thinning agent), sugar mixture [manufactured by Sanwa Starch Co., Ltd., trade name: Sandeck 30] reversible thermochromic writing instrument ink comprising 3.0 parts, phosphate ester surfactant 0.5 part, antifungal agent 0.1 part, triethanolamine 1.0 part, water 70.1 part A composition was prepared.

Preparation of writing instrument A ball holding portion formed by sucking and filling the ink composition tube made of polypropylene resin with the ink composition, and pressing and deforming the vicinity of the tip of the metal pipe inward from the outer surface via the resin connection member And a ballpoint pen tip holding a stainless steel ball having a diameter of 0.7 mm.
Next, an ink backflow prevention body (liquid stopper) and a rare gas were filled from the rear end of the polypropylene pipe, and a ballpoint pen refill was obtained in which the tail plug was fitted to the rear part of the pipe to make the inside pressurized. .
The ballpoint pen refill was incorporated into a shaft tube to obtain a retractable writing instrument (ballpoint pen).
The writing instrument is housed in the shaft cylinder in a state where the tip provided on the ballpoint pen refill is exposed to the outside air, and the shaft cylinder is activated by the operation of the retracting mechanism (knock mechanism) provided at the rear end of the shaft cylinder. The chip protrudes from the front end opening.
In addition, a friction member made of SEBS resin is provided around the shaft cylinder tip opening.

A letter (handwriting) was formed by writing on light yellow paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters were erased, and a cloudy afterimage was not visually recognized at the writing location.

Comparative Example 1
Preparation of ink composition for reversible thermochromic writing instrument 25.0 parts of the microcapsule pigment E, 0.3 part of succinoglycan (shear thinning agent), 10.0 parts of urea, 10.0 parts of glycerin, phosphate ester 0.5 part of a surfactant, 0.6 part of a nonionic permeability imparting agent, 0.1 part of a modified silicone antifoaming agent, 0.1 part of an antifungal agent, 0.5 part of triethanolamine, water 47. An ink composition for reversible thermochromic writing instruments consisting of 5 parts was prepared.

Preparation of Writing Instruments An ink containing tube made of polypropylene resin was connected to a pen body holding a 0.5 mm stainless steel ball at the tip through a resin holder.
The ink composition was filled into the ink containing tube, then an ink backflow preventer (liquid stopper) was filled at the rear end of the ink, and a tail plug was fitted into the rear part of the ink containing tube to obtain a refill.
Further, the refill is incorporated in a shaft cylinder (comprised of a front shaft cylinder and a rear shaft cylinder), a cap is fitted, and then a deaeration process is performed by a centrifugal process to write a writing instrument (ball pen)
In addition, SEBS rubber is provided as a friction member at the rear portion of the rear shaft cylinder.

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters disappeared, but a cloudy afterimage was visually recognized at the writing location.

Comparative Example 2
Preparation of ink composition for reversible thermochromic writing instrument The microcapsule pigment F20.0 parts, hydroxyethyl cellulose [manufactured by Union Carbide Japan Co., Ltd., trade name: cellosize WP-09L], glycerin 18.0 parts, Add 0.02 part of antifoaming agent, 1.5 part of preservative, 59.88 parts of water and 0.1 part of 10% diluted phosphoric acid solution and stir uniformly to obtain an ink composition for reversible thermochromic writing instrument. Obtained.

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

A letter (handwriting) was formed by writing on black paper using the writing instrument.
The handwriting was orange at room temperature (25 ° C.), and when rubbed with a friction member made of SEBS attached to the shaft cylinder, the characters disappeared, but a cloudy afterimage was visually recognized at the writing location.

t ₁ Complete color development temperature of reversible thermochromic microcapsule pigment with heat decoloring type t ₂ Color development start temperature of reversible thermochromic microcapsule pigment with heat decoloration type t ₃ Reversible thermochromic microcapsule pigment with heat decoloration type Decoloration start temperature of t ₄ Complete decolorization temperature of reversible thermochromic microcapsule pigment of heat decoloring type T ₁ Complete decoloration temperature of reversible thermochromic microcapsule pigment of ₁ heating color developing type T ₂ Reversible heat of color developing type of heat decoloring type Discoloration start temperature of the color-changing microcapsule pigment T ₃ Color development start temperature of the reversible thermochromic microcapsule pigment of the ₃ heating color development type T ₄ Color development temperature of the reversible thermochromic microcapsule pigment of the heat development color type ΔH Hysteresis width 1 Writing instrument 2 Ink occlusion body 3 Chip 31 Transparent member 4 Shaft cylinder 41 Front shaft cylinder 42 Rear shaft cylinder 5 Connection member 6 Cap 7 Friction member 8 Ink composition 9 Stirrer 10 Mechanism 11 ink reservoir 12 ink follower 13 breechblock 14 Refill 15 rubber seal 16 ink adjustment member 17 intermediate member 18 ink tank 181 plug 19 lid

Claims (9)

  (B) Reversible heat encapsulating a reversible thermochromic composition comprising a reaction medium that determines the temperature at which the color reaction of both occurs (b) an electron-donating color-forming organic compound; A color-changing microcapsule pigment and at least water, wherein the reversibly thermochromic microcapsule pigment has an average particle size in the range of 0.1 to 0.49 μm, and particles of 1.5 μm or more are all microcapsules An ink composition for a reversible thermochromic writing instrument, characterized by being 5% by volume or less in the pigment. 2. The reversible composition according to claim 1, wherein the reversible thermochromic microcapsule pigment has a complete decolorization temperature (t ₄ ) of 50 ° C. or more and a complete color development temperature (t ₁ ) of 0 ° C. or less with respect to a color density-temperature curve. An ink composition for thermochromic writing instruments.   The ink composition for reversible thermochromic writing instruments according to claim 1 or 2, comprising a shear thinning agent.   The ink composition for a reversible thermochromic writing instrument according to claim 3, comprising a sugar mixture containing at least 30% by mass of a starch saccharified product of 8 or more sugars and / or a reduced product thereof.   The ink composition for reversible thermochromic writing instruments according to claim 1 or 2, comprising a water-soluble polymer flocculant.   A writing instrument in the form of a ballpoint pen containing the water-based ink composition for reversible thermochromic writing instrument according to claim 3 or 4.   A writing instrument in the form of a marking pen containing the water-based ink composition for reversible thermochromic writing instrument according to claim 5.   The writing instrument according to claim 6 or 7, wherein a friction member is provided on the writing instrument.   The writing instrument according to claim 8, wherein the friction member is an elastomer or a plastic foam.

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