JP6580384B2 - Direct liquid writing instrument and ink cartridge used therefor - Google Patents

Description

The present invention relates to a direct liquid writing instrument in which ink is guided from an ink storage unit to a pen tip via a pen core, and an ink cartridge used therefor .

Conventionally, a large number of thin disk bodies are arranged in parallel with a slight gap (comb groove-like interval) between them, and a slit-shaped ink guide groove that passes through the disk body in the axial direction and a ventilation groove wider than the groove are provided. A writing instrument of a type that guides ink from the ink storage section to the pen tip via a so-called pen core, in which an ink guide core for guiding the ink from the ink storage section to the pen tip is arranged at the shaft center. Liquid writing instruments) are widely used.
The pen core is usually molded from a synthetic resin material, and its surface is relatively hydrophobic. Therefore, when applying water-based ink, the surface tension of the ink is adjusted or a surfactant is added. By doing so, the affinity (wetting property) with a pen core is improved (for example, refer patent document 1).
In addition, the direct liquid writing instrument tends to use a cartridge-type writing instrument in which the ink storage unit can be replaced from the viewpoint of high economic efficiency and environmental consideration (see, for example, Patent Document 2).

JP-A-3-79682 JP 2005-324336 A

  In the technique of the above-mentioned Patent Document 1, without adding a nonionic surfactant, without causing ink drop from the pen tip and poor ink recovery in the pen core, which has occurred by lowering the surface tension of the ink, Although it improves the wettability of the pen core, depending on the structure of the writing instrument to be applied, ink ejection during writing lacks stability. In particular, when the water-based ink is applied to an ink cartridge type writing instrument as in Patent Document 2, ink ejection stability is obtained during initial writing (that is, until the first connected cartridge is used up). However, when replacing the cartridge with a new one, the air supply from the ink reservoir to the pen tip becomes unstable due to the inclusion of air bubbles during the replacement, and the ink ejection stability during writing cannot be obtained. May not be obtained stably.

The present invention is a water-based ink that is applied to a writing instrument having the above-described pen core, and can exhibit pen core performance without causing ink drop off from the pen nib and ink recovery failure in the pen core. Ink ejection at the time of writing that can stably provide ink supply to the pen tip after replacement of the cartridge for a long time even when applied to ink cartridge type direct liquid writing instruments as well as providing ejection stability It is an object of the present invention to provide a direct liquid type writing instrument incorporating a water-based ink composition for a writing instrument excellent in stability and cartridge exchangeability, and an ink cartridge used therefor .

The present invention relates to a pen tip, an ink storage unit in the form of an ink cartridge that can be attached to and detached from the writing instrument body, and a plurality of disc bodies arranged in parallel at intervals of a comb groove shape, and a slit shape penetrating the disc body in the axial direction. the ink guiding grooves and ventilation grooves of large width are provided from the groove, is composed of a pen core which ink guiding core is disposed for guiding the ink from the ink reservoir to the axis to the pen tip, the A direct liquid containing a water-based ink composition containing water, a colorant, polyoxyethylene polyoxypropylene glycol and / or polyoxyethylene polyoxypropylene alkyl ether, and an emulsion of silica or silicone resin in the ink reservoir. Require a formula writing instrument .
Furthermore, it is required that the emulsion is added in the range of 0.01 to 5% by weight in the total amount of the ink composition.
Furthermore, the pen point is a ballpoint pen tip that holds a ball at the tip of a metal pipe, a core is disposed in the metal pipe, and an inner diameter B of the metal pipe and an outer diameter C of the core are , B / C ≦ 2 .
Furthermore, the ink cartridge used for any of the direct liquid writing instruments described above is a requirement.

By applying to the writing instrument provided with the pen lead by this invention, while exhibiting favorable pen lead performance, ink discharge stability can be obtained over a long period of time. In particular, when applied to an ink cartridge type direct liquid writing instrument, the ink supply to the pen tip is stably maintained even after replacement of the ink cartridge at the beginning, and is uniform during writing. a handwriting can be formed over a long period, Ri Do a water based ink composition for a writing instrument which is excellent in ink ejection stability, ink cartridge replacement time of the ink follower of excellent ink cartridges and Chokuekishiki writing instrument (cartridge exchange performance) Is obtained.
In particular, by adding a specific emulsion to the ink, it is possible to maintain a stable ink ejection property even for long-term continuous use accompanying ink cartridge replacement.

  In general, water-based ink applied to a direct liquid writing instrument equipped with a pen core cannot retain ink in the comb groove when the surface tension is too high, and ink from the pen tip via the induction core due to a change in atmospheric pressure inside the writing instrument. In the case of a pen tip having a low capillary force, a hand or a break occurs in the handwriting. In addition, when the surface tension is too low, a problem such as that the ink held in the comb groove portion cannot be recovered due to a change in atmospheric pressure inside the writing instrument arises. Therefore, various ink compositions are applied so as to regulate the surface tension. On the other hand, in the present invention, by using polyoxyethylene polyoxypropylene glycol or polyoxyethylene polyoxypropylene alkyl ether, the above problems can be solved regardless of the surface tension, and it cannot be obtained only by adjusting the surface tension. In addition, the present inventors have found that ink supply stability (cartridge exchangeability) at the time of ink cartridge replacement can be imparted.

The polyoxyethylene polyoxypropylene alkyl ether is a compound represented by the general formula (1), and is a random copolymer having a structure in which ethylene oxide and propylene oxide are polymerized in an arbitrary arrangement. Polyoxyethylene polyoxypropylene glycol is a compound in which R in the formula of general formula (1) is H.
R—O— (C ₃ H ₆ O) _m (C ₂ H ₄ O) _n —H (1)
[Wherein R represents an alkyl group, and m and n each independently represents a number of 1 to 40]
Examples of the alkyl group represented by R in the general formula include those having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms. The number of moles of ethylene oxide and propylene oxide added represented by m and n is independently 1 to 40, preferably 1 to 24.
In particular, those having a molecular weight of 800 to 3500 are preferred from the viewpoint that the ink viscosity is hardly increased by addition.

Specific examples of the polyoxyethylene polyoxypropylene glycol and the polyoxyethylene polyoxypropylene alkyl ether include unilube 50MB-2, 50MB-5, 50MB-11, 50MB-26, 50MB-72, 50MB-168, 75DE-25, 75DE-60, 75DE-170 (above, NOF Corporation),
Carpol GH-5, GH-10, GH-200, MH-20, MH-70, MH-150, MH-500 (above, manufactured by ADEKA) and the like.

The polyoxyethylene polyoxypropylene glycol or polyoxyethylene polyoxypropylene alkyl ether can be added in the range of 0.1 to 10% by weight, preferably 1 to 5% by weight, based on the total amount of the ink composition.
If it is less than 0.1% by weight, it is difficult to give sufficient ink ejection performance, and even if added in excess of 10% by weight, no improvement in ink ejection performance beyond a certain level is observed. No addition is required.

  Furthermore, by using an emulsion obtained by emulsifying silica or silicone resin with an emulsifier, the ink supply to the nib after the ink cartridge replacement is further stabilized while maintaining the above effect, and the handwriting is uniform over a long period of time. Can be formed. In particular, since the stability effect is maintained even after a long period of time, a plurality of ink cartridges stocked for a long period of time are used, and it is more useful for a cartridge-type writing instrument in which a single writing instrument body continues to be used for a long period of time. It will be something.

As an emulsifier for emulsifying the silica or the silicone resin, either one having strong hydrophilicity or one having strong lipophilicity can be used. Specifically, strong emulsifiers include alkaline soaps, organic amine soaps, sulfates of higher alcohols, tweens nonionic active agents, vegetable gums (gum arabic, abramin, casein, etc.), alginic acid, carboxymethyl Cellulose, saponin and the like can be exemplified, and those having strong lipophilicity include heavy metal soap, lanolin, rosin, cholesterol, lecithin, fatty acid ester of polyhydric alcohol in nonionic surfactant and the like.
In particular, silicone-based surfactants and sorbitan-based surfactants are effective because they have high emulsifying properties for silica and silicone resins and exhibit high effects in a small amount.

The emulsion is added in an amount of 0.01 to 5% by weight, preferably 0.1 to 3% by weight, based on the total amount of the ink composition.
If it is less than 0.01% by weight, it is difficult to obtain the desired effect, and even if it is added in excess of 5% by weight, no improvement of the effect is observed, so no further addition is required.

As the colorant, dyes and pigments that can be dissolved or dispersed in an aqueous medium can be used, and specific examples thereof are illustrated below.
As the dye, an acid dye, a basic dye, a direct dye, or the like can be used.
Examples of the acid dye include New Coxin (CI. 16255), Tartrazine (CI. 19140), Acid Blue Black 10B (CI. 20470), Guinea Green (CI. 42085), Brilliant Blue FCF. (CI.42090), Acid Violet 6B (C.I.42640), Soluble Blue (C.I.42755), Naphthalene Green (C.I.44025), Eosin (C.I.45380), Phloxin (C.I. 45410), erythrosine (C.I. 45430), nigrosine (C.I. 50420), acid flavin (C.I. 56205) and the like are used.
Examples of basic dyes include chrysoidine (C.I. 11270), methyl violet FN (C.I. 42535), crystal violet (C.I. 42555), malachite green (C.I. 42000), Victoria blue FB ( CI 44045), rhodamine B (C.I. 45170), acridine orange NS (C.I. 46005), methylene blue B (C.I. 52015) and the like are used.
As direct dyes, Congo Red (C.I. 22120), Direct Sky Blue 5B (C.I. 24400), Violet BB (C.I. 27905), Direct Deep Black EX (C.I. 30235), Kaya Las Black G Conch (C.I. 35225), Direct Fast Black G (C.I. 35255), Phthalocyanine Blue (C.I. 74180) and the like are used.

Examples of the pigment include inorganic pigments such as carbon black and ultramarine blue, and organic pigments such as copper phthalocyanine blue and benzidine yellow, as well as water-dispersed pigments that are finely and stably dispersed in an aqueous medium in advance using a surfactant or the like. For example, C.I. I. Pigment Blue 15: 3B [Product Name: S.P. S. Blue GLL, pigment content 22%, manufactured by Sanyo Color Co., Ltd.], C.I. I. Pigment Red 146 [Product Name: S.P. S. Pink FBL, pigment content 21.5%, manufactured by Sanyo Dye Co., Ltd.], C.I. I. Pigment Yellow 81 [Product name: TC Yellow FG, pigment content about 30%, manufactured by Dainichi Seika Kogyo Co., Ltd.], C.I. I. Pigment Red220 / 166 [Product name: TC Red FG, pigment content: about 35%, manufactured by Dainichi Seika Kogyo Co., Ltd.].
As the fluorescent pigment, a fluorescent pigment in the form of fine particles of a synthetic resin in which various fluorescent dyes are formed into a solid solution in a resin matrix can be used.
In addition, pearl pigments, gold and silver metallic pigments, luminous pigments, white pigments such as titanium dioxide used in correction pens, metal powders such as aluminum, thermochromic compositions, photochromic compositions, and fragrances Examples thereof include capsule pigments directly or microencapsulated.

The thermochromic composition includes (a) an electron-donating color-forming 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 occurs. The composition is suitable and is encapsulated in microcapsules and applied as a reversible thermochromic microcapsule pigment.
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 decolorable microcapsule pigment in which a reversible thermochromic composition having relatively small characteristics (ΔH = 1 to 7 ° C.) is encapsulated in a microcapsule can be applied.

Furthermore, comparatively large hysteresis characteristics (ΔH = 8 to 50) described in JP-B-4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, and the like. C.) can also be applied.
In addition, the large hysteresis characteristics described in JP-A-2005-1369, JP-A-2006-137886, JP-A-2006-188660, JP-A-2008-45062, JP-A-2008-280523, etc. In other words, the shape of the curve plotting the change in color density due to the temperature change is the case where the temperature is raised from the lower temperature side than the color change temperature range and the case where the temperature is lowered from the higher temperature side than the color change temperature range. The color changes in a very different route, and the color development state in the low temperature range below the complete color development temperature, or the color erase state in the high temperature range above the complete color erase temperature is a specific temperature range (substantially two-phase holding temperature range). It is also possible to use a microcapsule pigment encapsulating a reversible thermochromic composition having color memory.
Specifically, as the reversible thermochromic composition having color memory, a complete color development temperature 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 complete decoloring temperature obtained from a frictional heat generated by a friction body, a heating body such as a hair dryer, that is, 50 to 95 ° C., preferably 50 to 90 ° C. More preferably, by specifying the range of 60 to 80 ° C. and specifying the ΔH value of 40 to 100 ° C., it is possible to effectively function to maintain the color exhibited in the normal state (daily life temperature range).

The colorant may be used singly or in combination of two or more, and is used in the range of 1 to 30% by weight, preferably 2 to 20% by weight in the ink composition.
Further, when a pigment is used as the colorant, a pigment dispersant can be added as necessary. Examples of the pigment dispersant include surfactants such as anions and nonions, anionic polymers such as polyacrylic acid and styreneacrylic acid, and nonionic polymers such as PVP and PVA.

In addition, a conventional general-purpose water-soluble organic solvent compatible with water can be used. Specifically, ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol mono Examples include ethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, and N-methyl-2-pyrrolidone.
In addition, the said water-soluble organic solvent can be used 1 type or in combination of 2 or more types, and is used in 2 to 60 weight%, Preferably it is 5 to 35 weight%.

  Furthermore, a water-soluble resin can be added in order to impart adhesion and viscosity to the paper surface. Examples of the water-soluble resin include alkyd resins, acrylic resins, styrene maleic acid copolymers, cellulose derivatives, polyvinyl pyrrolidone, polyvinyl alcohol, and dextrin. The water-soluble resin can be used alone or in combination of two or more, and is used in the range of 1 to 30% by weight in the ink composition.

  Further, a surfactant or a water-soluble cutting oil can be added to the ink. These surfactants and water-soluble cutting oils are useful for adjusting the ink physical properties, and also act effectively in adjusting to a desired surface tension value.

Examples of the surfactant include phosphate ester surfactants, silicone surfactants, fluorine surfactants, acetylene glycol surfactants, anionic surfactants, nonionic surfactants, and the like. It is done.
In addition, since phosphate ester type | system | group surfactant has adsorption power with respect to metals, it shows high lubricity by adsorb | sucking with respect to a ball | bowl or a chip | tip main body. Therefore, it is more useful in a ballpoint pen-type writing instrument.

  Examples of the phosphoric ester surfactant include phosphoric acid monoester of polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether, phosphoric diester of polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether, phosphoric acid triester Or the derivative | guide_body etc. can be illustrated and these phosphate ester type surfactants are used individually or in mixture of 2 or more types. Among these, in view of ink aging stability, phosphoric acid monoesters and phosphoric acid diesters of polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether are most preferable.

In addition, as necessary, inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, pH adjusters such as organic basic compounds such as water-soluble amine compounds, rust preventives such as tolyltriazole and saponin, coalic acid, 1,2-benzthiazolin-3-one sodium salt, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, etc. Preservatives or antifungal agents, urea, sorbit, mannitol, sucrose, glucose, reduced starch hydrolyzate, wetting agents such as sodium pyrophosphate, and antifoaming agents may be used.
Further, when applied to a ballpoint pen-type writing instrument, a lubricant can be added, such as metal soap, polyalkylene glycol fatty acid ester, ethylene oxide addition type cationic surfactant, dicarboxylic acid type surfactant, β-alanine type interface. Activator, 2,5-dimercapto-1,3,4-thiadiazole and its salts and oligomers, 3-amino-5-mercapto-1,2,4-triazole, thiocarbamate, dimethyldithiocarbamate, N- A condensate of acyl-L-glutamic acid and L-lysine or a salt thereof is used.

  Furthermore, if necessary, a shear thinning agent can be added to give the ink an appropriate viscosity for practical use. The shear thinning agent to be used can be appropriately selected from conventionally known agents. Specific examples thereof include xanthan gum, succinoglycan, carrageenan and other polysaccharides, polyacrylic acid, cross-linked acrylic acid, polyvinylacetamide, Nonionic surfactants, anionic surfactants, associative urethane emulsions and the like can be mentioned, and these can be used alone or in combination.

  In the water-based ink composition, various tips are attached to the writing tip, the ink is directly stored in the shaft cylinder (ink storage unit), and a comb-shaped ink flow rate adjusting member (pen core) made of synthetic resin is interposed. In addition to being filled directly into general-purpose direct liquid type (pen-core type) writing instruments such as marking pens, ballpoint pens, brush pens, and fountain pens having a structure, the ink storage part of an ink cartridge detachable from the writing instrument body is filled.

Among the chips constituting the writing instrument, as a marking pen tip, for example, a fiber tip, a felt tip, a plastic tip, a brush, etc. can be applied, and as a ballpoint pen tip, the vicinity of the tip of a metal pipe is inward from the outer surface. A chip formed by holding the ball in the pressed ball holding part, a chip formed by holding a ball in the ball holding part formed by cutting a metal material with a drill or the like, and a metal or plastic chip inside A chip provided with a resin ball receiving seat, or a ball held by the chip biased forward by a spring body can be applied. The ball may be made of cemented carbide, stainless steel, ruby, ceramic, resin, rubber, or the like, and those having a diameter in the range of 0.15 mm to 2.0 mm are preferably used. Further, the ball may be subjected to a surface treatment such as DLC coating.
Further, as a fountain pen-shaped tip (pen body), a metal plate such as a stainless steel plate or a gold alloy plate is cut into a taper taper shape, bent or curved, or resin-molded into a pen tip shape can be applied. . The pen body can be provided with a slit at the center or a ball at the tip.
As described above, since the ink of the present invention has excellent ink supply performance to the nib, it is useful in that high discharge stability can be expressed regardless of the type of nib.

In particular, a ball-point pen tip has a poor capillary force of the tip itself and a low ink induction force to the writing tip, and therefore, when the surface tension is high like water-based ink, the discharge stability tends to be lowered. For this reason, in a chip using a metal pipe with particularly poor ink ejection properties, it is preferable to provide a configuration in which the capillary force inside the chip is increased by disposing a core in the chip.
In this case, by setting the inner diameter B of the metal pipe and the outer diameter C of the core to be in the range of B / C ≦ 2, high discharge without causing clogging of water-based ink or excessive discharge. A ballpoint pen that can maintain stability.

  As the material of the pen core, any of general-purpose polycarbonate, polypropylene, polyethylene, acrylonitrile-butadiene-styrene copolymer, etc. may be used as long as it is a synthetic resin that can be injection-molded into a structure in which a large number of discs are comb-shaped. However, an acrylonitrile-butadiene-styrene copolymer is preferable because it has a high moldability and can easily achieve pen core performance.

Furthermore, the ink storage part that is disposed behind the pen core and stores the water-based ink can be in the form of an ink cartridge as a structure that can be attached to and detached from the writing instrument body. In this case, since the ink stored in advance is used up and replaced with a new ink cartridge, it is necessary to newly cause the ink in the ink storage section to flow to the pen tip. Therefore, application of the ink of the present application configuration becomes more useful.
As the ink cartridge, one that also serves as a shaft cylinder constituting the writing instrument by being connected to the writing instrument body, or one that covers and protects the shaft cylinder (rear shaft) after being connected to the writing instrument body can be applied. In the latter case, in addition to the application of the ink cartridge alone, the writing instrument before use, in which the writing instrument body and the ink cartridge are connected, or the user uses the ink cartridge in the shaft cylinder when the writing instrument is used It may be any of those accommodated in the shaft cylinder in a non-connected state so as to start.

Examples will be described below, but the present invention is not limited to these examples.
The table below shows the compositions of the water-based inks for direct liquid writing instruments of Examples and Comparative Examples and the outer diameter of the core used. In addition, the numerical value of a composition in a table | surface shows a weight part. The surface tension was measured at 20 ° C. using a surface tension meter DY-300 manufactured by Kyowa Interface Science Co., Ltd.

The contents of the raw materials in the table will be described along the note numbers.
(1) Product name: Water Black 191L, manufactured by Orient Chemical Co., Ltd.
(2) Sanyo Dye Co., Ltd., trade name: Sundai Super Black CE: 30% pigment content
(3) Product name: Brilliant Blue FCF-L, manufactured by Daiwa Kasei Kogyo Co., Ltd.
(4) NOF Corporation product name: UNILOVE 75DE-60
(5) NOF Corporation product name: UNILOVE 50MB-11
(6) Nikko Chemicals Co., Ltd., trade name: Nikkor NP-20
(7) Product name: Surflon S-111N, manufactured by AGC Seimi Chemical Co., Ltd.
(8) Product name: Prisurf AL, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
(9) Arch Chemicals Japan, trade name: Proxel XL-2
(10) Emulsion obtained by emulsifying silica with silicone surfactant, manufactured by Toray Dow Corning Co., Ltd., trade name: FS Antifoam 013A
(11) An emulsion obtained by emulsifying a silicone resin with a sorbitan surfactant, manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KM-72

Preparation of Ink Each component was added to water, heated to room temperature or in the range of 50 ° C. to 60 ° C. as necessary, mixed and stirred, and then heated to stand to cool to prepare each ink.

Preparation of writing instrument A By filling each ink composition 0.5 g into the ink storage part of the pen core type writing instrument (Pilot Corporation, Hi-Tecpoint V5) having a ballpoint pen-shaped pen tip, and fitting a cap. A sample writing instrument A was prepared. The pen core of the writing instrument was formed by injection molding an ABS resin material.

Preparation of ink cartridge The inside of a bottomed cylindrical molded body made of polyethylene resin is used as an ink storage part, and after filling 0.9 g of each ink composition, an ink cartridge is press-fitted inside the opening. Got.

Production of writing instrument B Using a pen nib with a ball-point pen tip used in the writing instrument A, an ink cartridge can be accommodated on the front shaft provided with a connecting part (housing) that allows the ink storage part to be attached and detached. A writing instrument body was formed by screwing the rear shaft (cap is fitted).
A sample writing instrument B was prepared by connecting the previously prepared ink cartridge to the writing instrument body. Note that a stainless steel pipe having an inner diameter of 0.5 mm was used as the pen tip, and 0.10 mm, 0.30 mm, and 0.46 mm were used as the center core.

The following tests were conducted using the sample writing instrument.
Writing Test Each sample writing instrument A that was confirmed to be writable was handwritten on a commercially available report paper at room temperature by continuously writing 12 spiral circles in one line. At that time, the presence or absence of bleeding of the handwriting was confirmed visually.

Pen Core Performance Test Pen after holding the sample writing instrument A held in the pen tip downward state at 0 ° C. for 1 hour in the cap fitting state, then removing the cap and raising the pen tip downward state to 30 ° C. The state of ink flowing into the core comb groove and the presence or absence of ink splatter from the pen tip were observed. Further, when the ink was cooled again to 0 ° C., the state of ink collected from the pen core comb groove to the ink storage was observed.

Cartridge exchange test The sample writing instrument B was written on a JIS P3201 writing paper A at room temperature by continuously writing a spiral circle with a running tester (manufactured by Seiki Kogyo Laboratories), and then onto a new ink cartridge of the same configuration. It was exchanged and left for 1 hour in a state where the pen tip was removed with the cap removed. Then, the state of the handwriting at the time of 500 m continuous writing with the said travel test machine was confirmed.

Ink discharge test Each sample writing instrument B that was confirmed to be writable was written on the JIS P3201 writing paper A continuously at room temperature with the above running tester, and then replaced with a new ink cartridge of the same configuration. At the room temperature, the state of the handwriting when twelve spiral circles were continuously written in one line by hand on a commercially available report paper was confirmed.

Aging performance test Each sample writing instrument B and ink cartridge confirmed to be writable was stored for 30 days at 50 ° C., and then continuously written on JIS P3201 writing paper A at room temperature with the above running tester. I wrote it down. Further, the used cartridge was replaced with the ink cartridge stored at 50 ° C., and left for one hour in a state where the cap was removed and the pen tip faced downward. Thereafter, the ink ejection amount was measured by continuously writing 100 m with the running test machine. The ink discharge amount and the state of the handwriting when the measurement for each 100 m continuous writing was repeated 5 times (total of 500 m) were confirmed.
The results of each test are shown in the following table.

The evaluation of the test results is as follows.
Written test ○: A good handwriting was shown.
X: Bleeding was observed in the handwriting.
Pen core performance test ○: Inflow smoothly, but no dropout occurred. Moreover, all the ink in a pen core was collect | recovered favorably.
X: The inflow was irregular and the dropping of the ink occurred or the ink was not collected and remained in the pen core comb groove.
Cartridge replacement test ○: The ink supply to the pen tip was stable, and no smudges or line jumps were seen, and good handwriting was obtained.
X: Ink supply to the pen tip was irregular, and blurring and line jumping were observed in the handwriting.
Ink ejection test ○: Good handwriting was shown.
X: The blur and the line skip which continued intermittently in the handwriting occurred.
Aging performance test A: Scratches and line skipping were not observed, and good handwriting was obtained with constant ink ejection.
○: Slight blemishes were observed, but the ink ejection was constant.
X: The ink supply to the pen tip was irregular, and continuation of the handwriting and the skipped portions were intermittently generated.

Claims (4)

An ink storage part in the form of an ink cartridge that can be attached to and detached from the pen tip, a writing instrument body, and a slit-shaped ink guide groove in which a large number of disc bodies are arranged in parallel at intervals of a comb groove shape, and vertically pass through the disc body in the axial direction. And a pen core provided with a ventilation groove having a width wider than the groove, and an ink guide core for guiding ink from the ink storage section to the pen tip at the shaft center, and the ink storage section , water, a colorant, polyoxyethylene polyoxypropylene glycol and / or polyoxyethylene polyoxypropylene alkyl ether and, silica or direct liquid type writing instrument having a built-in water-based ink composition comprising an emulsion of a silicone resin. The direct liquid writing instrument according to claim 1, wherein the emulsion is added in an amount of 0.01 to 5% by weight based on the total amount of the ink composition. The nib is a ballpoint pen tip that holds a ball at the tip of a metal pipe, a center core is disposed in the metal pipe, and an inner diameter B of the metal pipe and an outer diameter C of the center core are B The direct liquid writing instrument according to claim 1, wherein / C ≦ 2. An ink cartridge for use in the direct liquid writing instrument according to any one of claims 1 to 3.