JP2012183706A - Ballpoint pen refill, and ballpoint pen housing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ballpoint pen refill in which color fastness to light of a reversible thermochromic ink composition incorporated in the ballpoint pen refill is significantly improved so as to last a thermochromic function, and provide a ballpoint pen housing the same.SOLUTION: In the ballpoint pen refill 1, the reversible thermochromic ink composition 6 and an ink backflow preventing body 7 are incorporated in an ink housing tube 5, which is formed of two or more resin layers, wherein at least one layer of the resin layers is formed of resin selected from ethylene vinyl alcohol copolymer resin, vinylidene chloride resin, acrylonitrile resin, and polyester resin. A ballpoint pen chip 2 is attached to one end of the ink housing tube. The ballpoint pen houses the ballpoint pen refill.

Description

  The present invention relates to a ballpoint pen refill and a ballpoint pen containing the same. More specifically, the present invention relates to a ballpoint pen refill containing a reversible thermochromic ink and a ballpoint pen containing the same.

Conventionally, a reversible heat comprising a reversible thermochromic composition comprising (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color reaction of both occurs. A ballpoint pen refill containing a discolorable ink composition is disclosed (for example, see Patent Document 1).
The ink composition comprises, as a colorant, (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reversible thermal discoloration comprising a reaction medium that determines the temperature at which the color reaction occurs. However, when the ink composition in a state where the reversible thermochromic composition is colored is exposed to light, the color density is lowered (fading) and a handwriting having a desired color density is obtained. Or when the ink composition in a state in which the reversible thermochromic composition has been decolored is exposed to light, it causes browning (coloring) degradation and the handwriting is visually recognized, or a desired color tone cannot be obtained during color development. May cause problems.
In order to solve the above problems, it is conceivable to include an ultraviolet absorber in the ink containing tube, or to provide a layer containing the ultraviolet absorber in the ink containing tube. However, the electron donating color-forming organic compound and the electron accepting compound may be used. In the system based on the electron transfer reaction, it is difficult to completely prevent the photo-degradation of the electron-donating color-forming organic compound only by the ultraviolet ray cutting means using the ultraviolet absorber or the like. Therefore, even if an attempt is made to contain a colorant in the ink storage tube or to provide a layer containing the colorant in the ink storage tube to shield light, the effect is not sufficient and the ink in the refill Since the amount cannot be visually recognized or is difficult to visually recognize, the convenience may be impaired.

JP-A-9-124993

  In the ballpoint refill incorporating the reversible thermochromic water-based ink composition, the present invention can significantly improve the light fastness and perpetuate the thermochromic function, and uses a transparent ink containing tube. Provides a ballpoint pen refill in which the remaining amount of ink can be visually recognized and a ballpoint pen containing the same.

The present inventors are greatly concerned with the presence of oxygen in the process of photodegradation of the thermochromic function of the electron donating reaction between the electron donating color-forming organic compound and the electron accepting compound of the reversible thermochromic composition. In an oxygen-free atmosphere, it is difficult to deteriorate even when irradiated with light, and if oxygen can be eliminated, light resistance (particularly direct sunlight) can be significantly improved. The present invention has been completed by finding that it is efficient and effective in preventing the deterioration of functions.
That is, the present invention comprises an ink container comprising two or more resin layers, wherein at least one of the resin layers is formed of a resin selected from an ethylene vinyl alcohol copolymer resin, a vinylidene chloride resin, an acrylonitrile resin, and a polyester resin. The tube contains a reversible thermochromic composition comprising (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color reaction of the two occurs. It has a built-in thermochromic ink composition and an ink backflow prevention body, and requires a ballpoint pen refill in which a ballpoint pen tip having a ball rotatably held at one end of the ink containing tube is mounted directly or via a connecting member. To do.
Further, the resin layer is composed of at least three layers, and a resin layer made of a resin selected from ethylene vinyl alcohol copolymer resin, vinylidene chloride resin, acrylonitrile resin, and polyester resin constitutes a layer excluding the inner surface layer and the outer surface layer. The inner surface layer and the outer surface layer are formed of a polyolefin resin, at least one layer of the resin layer contains an ultraviolet absorber, the ink containing tube has transparency, the reversible heat It is a requirement that the color-changing composition is in a colored state in the ink composition and that the reversible thermochromic microcapsule pigment encapsulating the reversible thermochromic composition is used.
Further, the ballpoint pen refill is accommodated in a shaft cylinder, and the ballpoint pen provided with a cap for covering the ballpoint pen tip or the ballpoint pen refill is accommodated in a shaft cylinder provided with a retracting mechanism. A ballpoint pen in which the writing tip portion of the ballpoint pen refill is projected and retracted from the front end opening portion of the barrel by operation is required.

  The present invention can remarkably improve the light fastness of the reversible thermochromic ink composition incorporated in the ballpoint pen refill and perpetuate the thermochromic function. Therefore, the ink container has excellent practicality and transparency. In a system using a tube, since the remaining amount of ink can be visually recognized, it is possible to provide a ballpoint pen refill that is highly convenient and a ballpoint pen containing the same.

It is explanatory drawing which shows the discoloration behavior of the microcapsule pigment which included the heat decoloring type reversible thermochromic composition. It is explanatory drawing which shows the discoloration behavior of the microcapsule pigment which included the heat decoloring type reversible thermochromic composition which has color memory property. It is explanatory drawing which shows the discoloration behavior of the microcapsule pigment which included the heating coloring type reversible thermochromic composition. It is explanatory drawing which shows one Example of the ball-point refill of this invention. It is explanatory drawing which shows one Example of the ball-point pen which accommodated the ball-point refill of FIG. It is explanatory drawing which shows the other Example of the ball-point pen which accommodated the ball-point refill of FIG. It is explanatory drawing which shows the other Example of the ball-point pen which accommodated the ball-point refill of FIG. It is explanatory drawing which shows the other Example of the ball-point pen which accommodated the ball-point refill of FIG.

The colorant contained in the reversible thermochromic ink composition determines (i) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) the temperature at which the color reaction of the both occurs. A reversible thermochromic composition comprising a reaction medium.
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 reversible thermochromic composition having a relatively small characteristic (ΔH = 1 to 7 ° C.) (discolored by heating and developed by cooling) can be applied (see FIG. 1).

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

The hysteresis characteristic in the color density-temperature curve of the reversible thermochromic composition will be described.
In FIG. 2, the vertical axis represents color density and the horizontal axis represents temperature. The change in color density due to the temperature change proceeds along the arrow. Here, A is a point indicating a density at a temperature t ₄ (hereinafter referred to as a complete decoloring temperature) that reaches a completely decolored state, and B is a temperature t ₃ (hereinafter referred to as a decoloring start temperature). C is a point indicating a density at a temperature t ₂ at which color development starts (hereinafter referred to as a color development start temperature), and D is a temperature t ₁ at which a complete color development state is reached (hereinafter referred to as a complete color development state). This is a point indicating a density at a color development temperature).
Discoloration temperature region is a temperature range between the t ₁ and t _4, it is possible to exhibit any of the states of the colored state and the decolored state, between t ₂ and t ₃ is a region having a large difference in color density The temperature range is substantially the discoloration temperature range.
The length of the line segment EF is a scale indicating the discoloration contrast, and the length of the line segment HG passing through the midpoint of the line segment EF is a temperature width indicating the degree of hysteresis (hereinafter referred to as hysteresis width ΔH). If this ΔH value is small, only one specific state can exist in the normal temperature range among both states before and after the color change. Further, when the ΔH value is large, it is easy to maintain each state before and after the color change.

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

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

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

Specific examples are given below.
Phenol, o-cresol, tertiary butylcatechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, n-butyl p-hydroxybenzoate N-octyl p-hydroxybenzoate, resorcin, dodecyl gallate, 2,2-bis (4-hydroxyphenyl) propane, 4,4-dihydroxydiphenylsulfone, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, 1-phenyl-1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4 -Hydroxyphenyl) -3-methylbu 1,1-bis (4-hydroxyphenyl) -2-methylpropane, 1,1-bis (4-hydroxyphenyl) n-hexane, 1,1-bis (4-hydroxyphenyl) n-heptane, , 1-bis (4-hydroxyphenyl) n-octane, 1,1-bis (4-hydroxyphenyl) n-nonane, 1,1-bis (4-hydroxyphenyl) n-decane, 1,1-bis ( 4-hydroxyphenyl) n-dodecane, 1,1-bis (4-hydroxyphenyl) 2-ethylhexane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) ethyl Propionate, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 2,2 Bis (4-hydroxyphenyl) n- heptane, there is 2,2-bis (4-hydroxyphenyl) n- nonane.
The compound having a phenolic hydroxyl group can develop the most effective thermochromic property, but aromatic carboxylic acids and aliphatic carboxylic acids having 2 to 5 carbon atoms, carboxylic acid metal salts, acidic phosphate esters and their It may be a compound selected from metal salts, 1,2,3-triazole and derivatives thereof.

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

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

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

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

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

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

[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.

（式中、Ｘは水素原子、炭素数１乃至４のアルキル基、炭素数１乃至４のアルコキシ基、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、こはく酸と２−フェノキシエタノールとのジエステル、スベリン酸と２−フェノキシエタノールとのジエステル、セバシン酸と２−フェノキシ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−フェノキシ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−フェノキシ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 (6) can also be used as the component (c).

(Wherein, X represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom, m represents an integer of 1 to 3, and n represents 1 to 20) Indicates an integer.)
Examples of the compound include a diester of succinic acid and 2-phenoxyethanol, a diester of suberic acid and 2-phenoxyethanol, a diester of sebacic acid and 2-phenoxyethanol, a diester of 1,10-decanedicarboxylic acid and 2-phenoxyethanol, An example is a diester of 1,18-octadecanedicarboxylic acid and 2-phenoxyethanol.

  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), Hydroxybenzoic acid esters (Japanese Patent Laid-Open No. 2001-105732), gallic acid esters and the like (Japanese Patent Publication No. 51-44706, Japanese Patent Laid-Open No. 2003-253149) are used. It is also possible to apply a reversible thermochromic composition that is decolored by cooling (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 is effective when applied as it is, but is preferably used as a microcapsule pigment encapsulated in microcapsules. This is because the reversible thermochromic composition can be kept in the same composition under the various use conditions and can exhibit the same effects.
Methods for microencapsulating the reversible thermochromic composition include interfacial polymerization, interfacial polycondensation, in situ polymerization, in-liquid curing coating, phase separation from aqueous solution, and phase separation 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 according to use. Further, a secondary resin film may be provided on the surface of the microcapsule according to the purpose to impart durability, or the surface characteristics may be modified for practical use.
Here, a non-thermochromic dye or pigment may be blended in the microcapsule pigment so as to exhibit a tautomatic color change from colored (1) to colored (2).
As the non-thermochromic dye and / or non-thermochromic pigment, a general dye or a general pigment is used.
The microcapsule pigment has an average particle size of 0.01 to 5.0 [mu] m, preferably 0.1 to 4.0 [mu] m, more preferably 0.5 to 3.0 [mu] m, which satisfies the practicality.
When the average particle diameter exceeds 5.0 μm, the microcapsule pigment clogs the gap between the ball and the ball holding portion when it is put into practical use by being accommodated in a ballpoint pen, and ink ejection properties are liable to be impaired. On the other hand, in a system of less than 0.01 μm, it is difficult to show a high density color developability.
The particle diameter is measured using a laser diffraction / scattering particle size distribution measuring apparatus (manufactured by Horiba, Ltd .; LA-300), and the average particle diameter (median diameter) is calculated based on the numerical value. .

The microcapsule pigment may have a circular cross section or a non-circular cross section.
Here, the reversible thermochromic composition: microcapsule wall film = 7: 1 to 1: 1 (mass ratio), preferably 6: 1 to 1: 1.
When the ratio of the reversible thermochromic composition to the wall film is larger than the above range, the thickness of the wall film becomes too thin, and the resistance to pressure and heat tends to decrease, and the ratio of the wall film to the reversible thermochromic composition When the value is larger than the above range, color density and sharpness during color development tend to be reduced.
The microcapsule pigments may be used alone or in combination of two or more, and used in the ink composition in the range of 10 to 50% by mass, preferably 15 to 45% by mass, more preferably 20 to 45% by mass. It is done.

The medium used in the ink composition may be 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, and the like.

Examples of the ink composition include a shear thinning ink containing a shear thinning agent.
By adding the shear thinning agent, it is possible to suppress bleeding of the handwriting, so that a good handwriting can be formed. Further, in a system using a reversible thermochromic microcapsule pigment, aggregation and sedimentation of the microcapsule pigment can be suppressed.
Furthermore, ink leakage from the gap between the ball and the ball holding portion when not in use can be prevented, and ink backflow can be prevented when the writing tip is left facing upward (upright state).
Examples of the shear thinning agent include xanthan gum, welan gum, succinoglycan (average molecular weight of about 1 to 8 million) whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose, guar gum, locust bean gum and derivatives thereof , Hydroxyethyl cellulose, alginic acid alkyl esters, polymers having a molecular weight of 100,000 to 150,000, mainly composed of alkyl esters of methacrylic acid, thickening agent having gelling ability extracted from seaweed such as glucomannan, agar and carrageenan Sugars, benzylidene sorbitol and benzylidene xylitol or their derivatives, crosslinkable acrylic acid polymers, inorganic particles such as smectite, hectorite, laponite, polyglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyester Glycol fatty acid esters, polyoxyethylene alkyl ethers, polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ether, nonionic HLB value, such as fatty acid amide is 8-12 surfactants, salts of dialkyl or dialkenyl sulfosuccinic acid. Examples thereof include a mixture of N-alkyl-2-pyrrolidone and an anionic surfactant, and a mixture of polyvinyl alcohol and an acrylic resin.
When the polysaccharide and inorganic particles are used in combination, inorganic particles selected from xanthan gum, smectite, hectorite, and laponite are preferably used.
Reversible thermochromic properties comprising (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling the color reaction of (a) and (b) as colorants. In a system using a microcapsule pigment in which a composition is encapsulated in a microcapsule, a ballpoint pen refill containing ink or a ballpoint pen writing tip is long in the air by using the polysaccharide and inorganic particles in combination. Even when left for a long time, it is possible to suppress the occurrence of scumming or inability to write due to drying of the nib.
The polysaccharide is contained in the ink composition in an amount of 0.2 to 0.5% by mass, and the mass ratio of the polysaccharide to the inorganic particles is 1: 0.2 to 1: 1.5. Ball pen refill that satisfies both the effect of suppressing the aggregation and sedimentation of the microcapsule pigment and the effect of suppressing the occurrence of scumming and inability to write due to drying of the pen tip, and showing good writing performance even after time, A ballpoint pen can be obtained.

In the ink composition, it is preferable to contain 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, which can improve the drying resistance, A sagging prevention performance can be imparted.
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, if necessary, an alkyd resin, an acrylic resin, a styrene maleic acid copolymer, a cellulose derivative, polyvinyl pyrrolidone, polyvinyl alcohol or the like may be added for fixing to the paper surface or imparting viscosity.

  Also, higher fatty acids such as oleic acid, nonionic surfactants having a long chain alkyl group, polyether-modified silicone oil, thiophosphite tri (alkoxycarbonylmethyl ester) and thiophosphite tri (alkoxycarbonylethyl ester) Thiophosphorous acid triester, polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether phosphoric acid monoester, polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether phosphoric acid diester, or metal salt or ammonium salt thereof It is preferable to add a lubricant such as an amine salt or an alkanolamine salt to prevent wear of the ball seat.

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

  When the reversible thermochromic ink composition incorporated in the ink containing tube changes color from colorless to colorless, the reversible thermochromic composition contained in the ink forms a colored state in order to form a handwriting that can be visually recognized during writing. It is preferable that

As the ballpoint pen tip, a tip holding a ball in a ball holding portion in which the vicinity of the tip of a metal pipe is pressed and deformed inward from the outer surface, a ball holding portion formed by cutting a metal material with a drill or the like A chip holding a ball on a metal, a plastic ball receiving seat inside a metal or plastic ball holding part, a chip holding the ball, a chip in which the ball is urged forward by a spring body, etc. Can be applied.
The ball is 0.1 to 2.0 mm, preferably 0.3 to 1.5 mm, more preferably 0.3 to 1.0 mm, such as cemented carbide, stainless steel, ruby, ceramic, resin, rubber, etc. The thing of a diameter is applicable.
The ballpoint pen tip and the ink containing tube are fitted directly or via a connecting member, and are filled with an ink composition and an ink backflow prevention body to form a ballpoint pen refill.

An ink backflow preventer is filled at the rear end of the ink stored in the ink storage tube.
The ink backflow preventer comprises a non-volatile liquid or a hardly volatile liquid.
Specifically, petroleum jelly, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or co-oligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, A polyether modified silicone oil, a fatty acid modified silicone oil, etc. are mentioned, 1 type, or 2 or more types can also be used together.
The non-volatile liquid and / or the hardly volatile liquid is preferably thickened to a suitable viscosity by adding a thickener. As the thickener, the surface is treated with hydrophobic silica, and the surface is methylated. Fine particle silica, aluminum silicate, swellable mica, hydrophobic thickener such as bentonite and montmorillonite, fatty acid metal soap such as magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, tribenzylidene sorbitol, Examples thereof include fatty acid amide, amide-modified polyethylene wax, hydrogenated castor oil, dextrin compounds such as fatty acid dextrin, and cellulose compounds.
Furthermore, the liquid ink backflow prevention body and the solid ink backflow prevention body can be used in combination.

A conventional ink storage tube, for example, an ink storage tube made of polypropylene, cannot sufficiently suppress the permeation of gas, so that oxygen sometimes enters the ink storage tube storage over time.
In the present invention, the ink containing tube containing the ink composition is composed of two or more resin layers, and at least one of the resin layers is made of an ethylene vinyl alcohol copolymer resin, a vinylidene chloride resin, an acrylonitrile resin, or a polyester resin. It is made of a resin that hardly permeates selected oxygen.
Therefore, as long as a resin layer selected from the above resins is formed, it may have any number of layers such as two layers, three layers or more, for example, four layers or five layers. The position at which the resin layer is formed is not particularly specified, such as the innermost, outermost or intermediate layer, but the resin layer is composed of at least three layers, an ethylene vinyl alcohol copolymer resin, a vinylidene chloride resin. The resin layer made of a resin selected from acrylonitrile resin and polyester resin is preferably a layer excluding the inner surface layer and the outer surface layer.
When the resin layer is composed of at least three layers, the inner surface layer and the outer surface layer are formed of a polyolefin resin such as general-purpose polypropylene, polyethylene, polymethylpentene, etc. in terms of solvent resistance, economy, and productivity. Is preferred.
The thickness of the ink storage tube is not particularly limited, and is not particularly limited as long as it is a thickness that satisfies oxygen permeability, but the outer diameter of the ink storage tube constituting the refill is roughly determined. If each resin layer is thickened, the inner diameter of the ink containing tube is reduced and the amount of ink contained is reduced. Therefore, the thickness of the ink containing tube is 0.1 to 1.5 mm, preferably 0.3 to 1. 0.0 mm, more preferably 0.5 to 0.8 mm.
Examples of the ethylene vinyl alcohol copolymer resin include Kuraray Co., Ltd., trade name: EVAL.
The vinylidene chloride resin may be a vinylidene chloride copolymer resin, such as vinylidene chloride-acrylonitrile copolymer, vinylidene chloride-methacrylic acid copolymer, vinylidene chloride-acrylate copolymer, vinylidene chloride-methacrylate copolymer. And vinylidene chloride-vinyl acetate copolymer.
In particular, in the case of a ballpoint pen in which a plurality of ballpoint pen refills are housed in the 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 retracting mechanism, the outer diameter of the shaft cylinder is reduced and held. In order to make it easy to hold, it is necessary to design the outer diameter of the ink containing tube to be small. Furthermore, in order to prevent a decrease in the amount of ink, it is necessary to make the thickness of the ink storage tube as thin as possible, and the application of the ink storage tube having the low oxygen permeability is an important requirement.
In addition, it is preferable that the said ink accommodating tube has transparency so that the ink remaining amount can be visually recognized.

The ink consumption obtained by writing using a ballpoint pen refill incorporating the ink composition is 0.7 to 1.4 mg / cm ² , preferably 0.8 to 1.3 mg / cm ^2. Since the reversible thermochromic composition used in the composition has a lower color density than a general dye or pigment, the color density of the handwriting is not sufficient with a small ink consumption set for a normal ballpoint pen. Therefore, it is preferable to supply ink to the chip so that the ink consumption per unit area is 0.7 mg / cm ² or more. In addition, if the ink consumption per unit area exceeds 1.4 mg / cm ² , the ink transferred onto the paper surface is difficult to dry.

By containing an ultraviolet absorber in at least one of the resin layers constituting the ink containing tube, the reversible thermochromic composition can improve the light fastness of the decolored state.
Examples of the ultraviolet absorber include 2,4-hydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxy. Benzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-octoxybenzophenone, bis- (2-methoxy-4-hydroxy-5-benzoylphenyl) -methane 2- [2'- Hydroxy-3'-5'-di-t-amylphenyl] -benzophenone, 2-hydroxy-4-dodecyloxy-benzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone 2-hydroxy-4-benzyloxyben Phenone, 2- [2'-hydroxy-3'-5'-di -t- amyl phenyl] - benzophenone ultraviolet absorbers such as benzophenone.
Phenyl salicylate, para-t-butylphenyl salicylate, para-octylphenyl salicylate, 2-4-di-t-butylphenyl-4-hydroxybenzoate, 1-hydroxybenzoate, 1-hydroxy-3-t-butyl-benzoate, 1 Salicylic acid ultraviolet absorbers such as hydroxy-3-t-octylbenzoate and resorcinol monobenzoate.
Cyanoacrylate UV absorption such as ethyl-2-cyano-3,3'-diphenyl acrylate, 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate, 2-ethylhexyl-2-cyano-3-phenylcinnarate Agent.
2- [5-t-butyl-2-hydroxyphenyl] -benzotriazole, 2- [5-methyl-2-hydroxyphenyl] -benzotriazole, 2- [2, hydroxy-3,5-bis (a, a -Dimethylbenzyl) phenyl] -2H benzotriazole, 2- [3,5-di-tert-butyl-2-hydroxyphenyl] -benzotriazole, 2- [3-tert-butyl-5-methyl-2-hydroxyphenyl ] -5-chlorobenzotriazole, 2- [3,5-di-t-butyl-2-hydroxyphenyl] -5-chlorobenzotriazole, 2- [3,5-di-t-amyl-2-hydroxyphenyl] ] -Benzotriazole, 2- [3-dodecyl-5-methyl-2-hydroxyphenyl] benzotriazole, 2- [3-t-butyl-5-propiyl] Octylate-2-hydroxyphenyl] -5-chlorobenzotriazole, 2- [2-hydroxyphenyl-3,5-di- (1,1'-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- [2- Hydroxy-5-t-octylphenyl] -2H-benzotriazole, 2- [3-t-butyl-5-octyloxycarbonylethyl-2-hydroxyphenyl] -benzotriazole, 2- [2-hydroxy-5-tetra Octylphenyl] -benzotriazole, 2- [2-hydroxy-4-octoxy-phenyl] -benzotriazole, 2- [2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimide Methyl) -5'-methylphenyl] -benzotriazole, 2- (2-hydroxy-5-t Butylphenyl) - benzotriazole ultraviolet absorbers such as benzotriazole.
Ethanediamide-N- (2-ethoxyphenyl) -N ′-(4-isododecylphenyl), 2,2,4,4-tetramethyl-20- (β-lauryl-oxycarbonyl) -ethyl-7-oxa- Examples include oxalic acid anilide ultraviolet absorbers such as 3,20-diazodispiro (5,1,11,2) heneic acid-21-one.

When the ink composition is accommodated in a ballpoint pen with a cap, the structure and shape of the ballpoint pen are not particularly limited, and the ballpoint pen refill writing tip (tip) is exposed outside and accommodated in the shaft cylinder. Any structure having a cap that covers the writing tip can be used.
In addition, when the ink composition is housed in a retractable ballpoint pen, the structure and shape of the retractable ballpoint pen are not particularly limited, and the writing tip provided on the ballpoint pen refill is exposed to the outside air. Any structure can be used as long as it is housed in the cylinder and the writing tip protrudes from the shaft cylinder opening by the operation of the retracting mechanism.
Examples of the operation method of the retracting mechanism include a knock type, a rotary type, and a slide type.
The knock type has a knock portion on the rear end portion of the shaft tube and the side surface of the shaft tube, and a configuration in which the ball-point pen tip is projected and retracted from the front end opening portion of the shaft tube by pressing the knock portion, or a clip portion provided on the shaft tube A configuration in which the ball-point pen tip is projected and retracted from the front end opening of the shaft cylinder can be exemplified by pressing.
The rotary type has a rotating part at the rear part of the shaft cylinder, and a configuration in which the ball-point pen tip is projected and retracted from the front end opening part of the shaft cylinder by rotating the rotating part can be exemplified.
The slide type has a slide part on the side surface of the shaft tube, and by operating the slide, the ballpoint pen tip is projected and retracted from the opening at the front end of the shaft tube, or by sliding a clip part provided on the shaft tube, A configuration in which the ball-point pen tip is projected and retracted from the front end opening of the shaft cylinder can be exemplified.
The retractable ballpoint pen is a compound type retractable ballpoint pen in which a plurality of ballpoint pen refills are accommodated in a shaft cylinder, and the writing tip of one of the ballpoint pen refills protrudes and retracts from the opening at the front end of the shaft cylinder by the operation of the retractable mechanism. May be.

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

Examples of the present invention are shown below, but the present invention is not limited thereto.
In addition, the part in an Example is a mass part, and the melt flow rate (MFR) of resin is the value measured according to JISK6921-2.
Example 1
Preparation of microcapsule pigment (a) 6 '-[ethyl (4-methylphenyl) amino] -2'-(methylphenylamino) -spiro [isobenzofuran-1 (3H), 9 '-[9H] xanthene as component (a) ] -3-one 5.0 parts, (b) Component 4,4 '-(2-ethylhexane-1,1-diyl) diphenol 5.0 parts, 2,2-bis (4'-hydroxyphenyl) A microcapsule pigment suspension containing a reversible thermochromic composition having color memory composed of 5.0 parts of hexafluoropropane) and 50.0 parts of 4-benzyloxyphenylethyl caprate as component (c). Obtained.
The suspension was centrifuged to isolate microcapsule pigment A.

Preparation of reversible thermochromic ink composition The microcapsule pigment has an average particle size of 2.0 μm, a complete decolorization temperature of 58 ° C., a complete color development temperature of −20 ° C., and changes from pink to colorless by temperature change. Discolor.
The microcapsule pigment (cooled in advance to −20 ° C. or less to make the microcapsule pigment develop a pink color) was used as a colorant.

  20.0 parts of the reversible thermochromic microcapsule pigment, xanthan gum [trade name: Kelzan ST, manufactured by Sanki Co., Ltd.] 0.3 part, sugar mixture [trade name: Sandeck 30, Sanwa Starch Co., Ltd. ] 1.5 parts, lubricant (trade name: Prisurf AL, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1.0 part, 1.0 part of triethanolamine and 76.2 parts of water were mixed to reversibly change the color. An ink composition was obtained.

Preparation of ink containing tube Polypropylene [extruded grade, MFR: 1 to 10] as the first layer (inner layer), ethylene vinyl alcohol copolymer resin [oxygen permeation rate of 0.4 cc · 20 μm / m2] as the second layer (intermediate layer) m ² · day · atm], polypropylene (extrusion molding grade, MFR: 1 to 10) as the third layer (outer layer), and an inner diameter of 1.7 mm by an extrusion molding machine (multilayer extrusion mold, 3 types, 3 layers) Then, it was extruded into a cylindrical shape with an outer diameter of 3.1 mm, and the length was cut to 100 mm to produce an ink containing tube.
The thickness of the first layer of the ink containing tube was 0.19 mm, the thickness of the second layer was 0.09 mm, and the thickness of the third layer was 0.42 mm.

Ballpoint refill fabrication (see Figure 4)
A ball holding portion formed by sucking and filling the ink composition 6 into the ink containing tube 5 and pressing and deforming the vicinity of the tip of the metal pipe inward from the outer surface via the resin connecting member (holder) 4. The ballpoint pen tip 2 holding a stainless steel ball 3 having a diameter of 0.5 mm was connected.
Next, an ink backflow preventer 7 (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 1.
The following tests were performed using the ballpoint pen refill.

Example 2
Preparation of ink containing tube As the first layer (inner layer), polypropylene (extrusion molding grade, MFR: 1 to 10) and 8: 2 mixture of polyolefin adhesive resin, as the second layer (intermediate layer), ethylene vinyl alcohol copolymer resin [Oxygen permeation rate: 1.5 cc · 20 μm / m ² · day · atm], 8 pairs of polypropylene (extrusion molding grade, MFR: 1 to 10) and polyolefin adhesive resin as a third layer (outer layer) 2 The mixture was extruded into a cylindrical shape with an inner diameter of 1.7 mm and an outer diameter of 3.1 mm by an extrusion molding machine (multilayer extrusion mold, 3 types, 3 layers), and the length was cut to 100 mm. An ink containing tube was prepared.
The thickness of the first layer of the ink containing tube was 0.19 mm, the thickness of the second layer was 0.09 mm, and the thickness of the third layer was 0.42 mm.

  A ballpoint pen refill was obtained in the same manner as in Example 1 except that the ink containing tube was used.

Example 3
Preparation of ink containing tube Polypropylene [extrusion grade, MFR: 1 to 10] as the first layer (inner layer), polyolefin adhesive resin as the second layer, ethylene vinyl alcohol copolymer resin [oxygen transmission rate 0 .4cc · 20μm / m ² · day · atm], polyolefin adhesive resin as the fourth layer, and polypropylene (extrusion grade, MFR: 1 to 10) as the fifth layer (outer layer) Extrusion molds, 5 types and 5 layers) were extruded into a cylindrical shape with an inner diameter of 1.7 mm and an outer diameter of 3.1 mm, and the length was cut to 100 mm to produce an ink containing tube.
The thickness of the first layer of the ink containing tube is 0.2 mm, the thickness of the second layer is 0.06 mm, the thickness of the third layer is 0.09 mm, and the thickness of the fourth layer is 0. 0.06 mm and the thickness of the fifth layer was 0.29 mm.

A ballpoint pen refill was obtained in the same manner as in Example 1 except that the ink containing tube was used.

Example 4
Preparation of ink containing tube Polypropylene [extrusion grade, MFR: 1 to 10] as the first layer (inner layer), polyolefin adhesive resin as the second layer, ethylene vinyl alcohol copolymer resin [oxygen transmission rate 0 .4 cc · 20 μm / m ² · day · atm], a polyolefin adhesive resin as the fourth layer, and a cyclic olefin copolymer [MFR: 5 to 20] as the fifth layer (outer layer). An ink containing tube was manufactured by extruding into a cylindrical shape with an inner diameter of 1.7 mm and an outer diameter of 3.1 mm by using a mold, 5 types and 5 layers, and cutting the length to 100 mm.
The thickness of the first layer of the ink containing tube is 0.2 mm, the thickness of the second layer is 0.06 mm, the thickness of the third layer is 0.09 mm, and the thickness of the fourth layer is 0. 0.06 mm and the thickness of the fifth layer was 0.29 mm.

A ballpoint pen refill was obtained in the same manner as in Example 1 except that the ink containing tube was used.

Comparative Example 1
Preparation of ink containing tube Polypropylene (extrusion molding grade MFR: 1 to 10) is extruded into a cylindrical shape with an inner diameter of 1.7 mm and an outer diameter of 3.1 mm by an extrusion molding machine to a length of 100 mm. The ink containing tube was prepared by cutting.
The wall thickness of the ink containing tube was 0.7 mm.

The following tests were conducted using each ballpoint pen refill.
Light resistance test Each ballpoint pen refill was irradiated with light for 300 hours at an irradiation intensity of 180 W / m2 using a xenon light resistance tester (Suga tester, xenon lamp applied), and the color tone of the ink visible through the refill was compared with the initial color tone. (Appearance test).
Each ball-point pen refill was set in a running test machine, and a spiral circle was continuously written on JIS P3201 writing paper A, and the state of the handwriting immediately after starting writing and immediately before finishing writing was visually observed.

The following table shows the results of the appearance test and the writing test.
In addition, the evaluation regarding the symbol of the test result in a table | surface is as follows.
Appearance test ○: No change was observed in the color of the ink compared to the initial stage.
X: Discoloration was seen in the ink compared with the initial stage.
Written test ○: There was no change in the color of the handwriting immediately after the start of writing and immediately before the end of writing.
X: Significant discoloration was observed in the color tone of the handwriting immediately after the start of writing and immediately before the end of writing.

Application example 1
Production of Ballpoint Pen The ballpoint refill obtained in Example 2 was incorporated into the shaft tube 9 to obtain a retractable ballpoint pen 8 (see FIG. 5).
The retractable ballpoint pen is housed in the shaft cylinder in a state where the writing tip provided on the ballpoint pen refill is exposed to the outside air, and by the operation of the retracting mechanism (knock mechanism) provided at the rear portion of the shaft cylinder. This is a structure in which the writing tip protrudes from the opening at the front end of the barrel.
The initial handwriting obtained by writing in a state where the ballpoint pen tip was projected and retracted from the opening at the front end of the barrel by the operation of the retracting mechanism was blue.
In addition, the said handwriting can be decolored by rubbing using the friction member 10 made from SEBS resin provided in the intrusion mechanism.

Application example 2
Production of Ballpoint Pen The ballpoint refill obtained in Example 3 was incorporated into the shaft tube 9 to obtain a retractable ballpoint pen 8 (see FIG. 6).
The retractable ballpoint pen is housed in the shaft cylinder with the writing tip provided on the ballpoint pen refill exposed to the outside air, and a clip-shaped retracting mechanism (slide mechanism) provided on the side surface of the shaft cylinder Is a structure in which the writing tip protrudes from the opening at the front end of the shaft cylinder.
The initial handwriting obtained by writing in a state where the ballpoint pen tip was projected and retracted from the opening at the front end of the barrel by the operation of the retracting mechanism was blue.
In addition, the said handwriting can be decolored by rubbing using the friction member 10 made from SEBS resin provided in the shaft cylinder rear end part.

Application example 3
Preparation of microcapsule pigment (i) 4.5 parts of 2- (2-chloroamino) -6-dibutylaminofluorane as component (4), 4,4 '-(2-ethylhexane-1, 1- Diyl) Color comprising 3.0 parts of diphenol, 5.0 parts of 2,2-bis (4'-hydroxyphenyl) -hexafluoropropane, and 50.0 parts of 4-benzyloxyphenylethyl caprate as component (c) A microcapsule pigment suspension containing a reversible thermochromic composition having a memory property was obtained.
The suspension was centrifuged to isolate reversible thermochromic microcapsule pigment B.
The microcapsule pigment has an average particle size of 2.3 μm, a complete color erasing temperature of 56 ° C., a complete color development temperature of −20 ° C., and changes from black to colorless according to temperature change.
The microcapsule pigment (cooled in advance to −20 ° C. or less to make the microcapsule pigment develop a black color) was used as a colorant.

  20.0 parts of the reversible thermochromic microcapsule pigment, xanthan gum [trade name: Kelzan ST, manufactured by Sanki Co., Ltd.] 0.3 part, sugar mixture [trade name: Sandeck 30, Sanwa Starch Co., Ltd. ] 1.5 parts, lubricant (trade name: Prisurf AL, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1.0 part, 1.0 part of triethanolamine and 76.2 parts of water were mixed to reversibly change the color. An ink composition was obtained.

Preparation of Ballpoint Pen Refill The ink composition was housed in the same ink containing tube as in Example 3 to obtain a ballpoint pen refill.

Preparation of Ballpoint Pen The ballpoint pen refill and the ballpoint pen refill obtained in Example 3 are incorporated in the light shielding shaft cylinder 9, and the writing tip of one of the ballpoint pen refills is opened from the front end opening of the shaft cylinder by the operation of the retracting mechanism. A retractable ballpoint pen 8 that appears and disappears was obtained (see FIG. 7).
A friction member 10 made of SEBS resin is provided in the vicinity of the opening at the tip of the shaft cylinder.
The initial handwriting obtained by writing in a state where the ballpoint pen tip was projected and retracted from the opening at the front end of the barrel by the operation of the retracting mechanism was pink and black.
The handwriting can be decolored by rubbing with a friction member.

Application example 5
An operation body having the same color as that of the ink composition was fitted to the rear part of the ink containing tube of the ballpoint pen refill obtained in Example 3.
An operation body having the same color as the ink composition was fitted to the rear part of the ink containing tube of the ballpoint pen refill obtained in Application Example 4.

Production of Ballpoint Pens The two refills for the ballpoint pen obtained as described above are incorporated into a transparent shaft cylinder 9 having a lid 11 that can be opened and closed at the rear, and the lid is closed, and then the operation body of the retracting mechanism is operated. Thus, a retractable ballpoint pen 8 in which the writing tip portion of any of the ballpoint pen refills protrudes and retracts from the front end opening portion of the shaft cylinder was obtained (see FIG. 8).
A friction member 10 made of SEBS resin is provided in the vicinity of the opening at the tip of the shaft cylinder.
The initial handwriting obtained by writing in a state where the ballpoint pen tip was projected and retracted from the opening at the front end of the barrel by the operation of the retracting mechanism was pink and black.
The handwriting can be decolored by rubbing with a friction member.

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 coloring type T ₄ Color development temperature of the reversible thermochromic microcapsule pigment of the heating ₄ coloring type ΔH Hysteresis width 1 Ballpoint refill 2 Ball-point pen tip 3 Ball 4 Connection member 5 Ink receiving tube 6 Ink composition 7 Ink backflow preventer 8 Ballpoint pen 9 Shaft cylinder 10 Friction Wood 11 lid

Claims (12)

  In an ink containing tube formed of a resin selected from ethylene vinyl alcohol copolymer resin, vinylidene chloride resin, acrylonitrile resin, and polyester resin. Reversible thermochromic ink composition comprising an electron-donating color-changing organic compound, (b) an electron-accepting compound, and (c) a reversible thermochromic composition comprising a reaction medium that determines the temperature at which the color reaction of both occurs. And a ballpoint pen refill in which a ballpoint pen tip having a ball rotatably held at one end of the ink containing tube is mounted directly or via a connecting member.   The resin layer comprises at least three layers, and the resin layer comprising a resin selected from ethylene vinyl alcohol copolymer resin, vinylidene chloride resin, acrylonitrile resin, and polyester resin constitutes a layer excluding the inner surface layer and the outer surface layer. The ballpoint pen refill according to 1.   The ballpoint pen refill according to claim 1 or 2, wherein the inner surface layer and the outer surface layer are formed of a polyolefin resin.   The ballpoint pen refill according to any one of claims 1 to 3, wherein an ultraviolet absorber is contained in at least one of the resin layers.   The ballpoint pen refill according to any one of claims 1 to 4, wherein the ink containing tube has transparency.   The ballpoint pen refill according to any one of claims 1 to 5, wherein the reversible thermochromic composition is in a colored state in the ink composition.   The ballpoint pen refill according to any one of claims 1 to 6, wherein the reversible thermochromic microcapsule pigment encapsulating the reversible thermochromic composition is used.   A ballpoint pen comprising a cap that covers the ballpoint pen tip, wherein the ballpoint pen refill according to any one of claims 1 to 7 is accommodated in a shaft cylinder.   The ballpoint pen refill according to any one of claims 1 to 7 is accommodated in a shaft cylinder provided with a retracting mechanism, and the writing tip portion of the ballpoint pen refill appears and disappears from the front end opening of the shaft cylinder by the operation of the retracting mechanism. Ballpoint pen to do.   The ballpoint pen according to claim 9, wherein a plurality of ballpoint pen refills are accommodated in the shaft cylinder, and a writing tip portion of any of the ballpoint pen refills protrudes and retracts from the front end opening portion of the shaft cylinder by the operation of the retracting mechanism.   The ballpoint pen according to any one of claims 8 to 10 in which said axial cylinder has transparency.   The ball-point pen as described in any one of Claims 8 thru | or 11 provided with a friction member.

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