JPH1142884A - Ink follow-up material gelled product for water-based ball-point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make separation of oil difficult while a low consistency assuring a high follow-up property is provided by a method wherein a viscosity of base oil is a specific value or under, a content of a thickener is a specific % or under, two or more kinds of thickeners of a combination with a different group are contained from the thickeners, and an ink follow up material gelled product is used individually or used jointly with a solid matter of a specific gravity within a specific range. SOLUTION: In a water-based ball-point pen for receiving an ink 20 directly in an ink receiving tube 10, an ink follow-up material gelled product 30 wherein a viscosity of base oil at 25 deg.C is 3 Pa.sec or under, a content of a thickener is 6% or under in total, and two or more kinds of thickeners having a combination with at least a different group from in the thickeners composed of groups of inorganic fine grain thickeners, viscosity thickeners, and metallic soaps are contained, is used independently, or used jointly with solid matter of which a specific gravity is 0.80 to 1.10. For a manufacture of the gelled product 30, as an exampls, a very simple method wherein after preliminarily kneading all gelled product components of all thickeners, base oil, surfactant, etc., at room temperature, it is kneaded with a dispersing machine such as a three rolls mill, the kneader, etc., suffices.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink follower for use at the tail end of an aqueous ballpoint pen ink directly accommodated in an ink reservoir.

[0002]

2. Description of the Related Art The viscosity of an ink for an aqueous ballpoint pen is 3 Pa · sec to 20 Pa for an oil ballpoint pen having a similar form.
-In contrast to 50 mPa-sec to 3 Pa-sec, the ink leaks when the pen is left upward or sideways. In addition, since ink may be scattered even by a slight impact to stain hands and clothes, an ink follower is provided to prevent this.

JP-A-48-40510, JP-A-57-1
53070, JP-A-57-200472, JP-A-58-1982
1772, JP-A-61-57673, JP-A-61-14
5269, JP-A-61-151289, JP-A-61-2
00187, JP-A-61-268786, JP-A-62-1987
50379, JP-A-62-148581, JP-A-62-148581
199492, JP-A-63-6077, JP-A-02-2
48487, JP-A-04-202281, JP-A-05-202
270192, JP-A-05-270193, JP-A-06
-200235, JP-A-06-220418, JP-A-0-220418
6-247094, JP-A-06-264048, JP-A-06-328890, JP-A-06-336584, JP-A-07-61187, JP-A-07-173426, JP-A-07-214974, JP-A-07-214975, JP-A-07-1979 242093, JP-A-07-266780,
JP-A-08-2171, JP-A-08-11481, JP-A-08-58282, JP-A-08-72465, JP-A-08-90982, JP-A-08-108679, JP-A-08-142570, JP-A-08-183286, JP-A-08-183286 08-300873, JP-A-08-300874, JP-A-09-11683, and JP-A-09-76687, etc., use a gel-like material or a combination of a gel-like material and a solid material in an aqueous ballpoint pen in which ink is directly stored in an ink storage tube. It is disclosed that an ink follower is provided. These inventions are aimed at various purposes and eyes, such as making it easy to follow ink, withstanding the impact of falling, enhancing the effect of preventing backflow, and improving the appearance.

[0004] A common feature of these is that a non-volatile or non-volatile solvent is given pseudoplasticity by using a certain thickener so that it does not flow backward even when left sideways or upward. Another characteristic is that in the case of conventional oil-based ballpoint pens, ink followers having the same consistency as general grease used for lubricants (hereinafter referred to as lubricating grease) were often used. , Viscosity and consistency are often low. This is for improving the followability to the ink. The amount of ink required for writing with a ball-point pen varies depending on the ball diameter.
A water-based ballpoint pen has a thickness of 0.3 mm to 0.7 mm and a water-based ballpoint pen has a thickness of 10 to 30 mg per 100 m for an oil-based ballpoint pen having a thickness of 1.0 mm to bold 1.0 mm.
Requires mg of ink. Since water-based ballpoint pens consume 5 to 10 times or more ink, strict ink following performance has been required for ink followers. Furthermore, these days,
Ballpoint pens that use metal powder or titanium oxide, such as gold, silver, or white, have appeared. However, the outflow of these special inks is 400mg / 100m when using 0.7mm balls.
In some cases, it is necessary to deal with an outflow amount that is 1.5 times the maximum value of the conventional color.

However, in general, the lower the viscosity of lubricating grease, the lower the stability, and if left unattended, a phenomenon in which oil is separated (oil separation) tends to occur. Further, since the thickener component easily moves in the lubricating grease, a sparse part and a dense part are mixed, and it is easy to lose the uniform state. Since the ink follower for the water-based ballpoint pen also uses a material similar to the lubricating grease, it exhibits a time-dependent behavior based on a similar physical law, which is a major problem. If oil separation occurs, it will affect the surfactant in the ink to weaken the effect in the ink, or cut off the ink flow path as oil droplets to adversely affect writing. In addition, if there is no uniformity, a part to be followed and a substance that adheres granularly to the inner wall of the ink storage tube will be formed, which not only makes the appearance worse, but also reduces the amount by the amount attached to the inner wall, and finally prevents volatilization and leakage. Also, the function as a follower of such as will be lost.

In Japanese Patent Application Laid-Open No. 06-328890, two or more gels having different viscosities of base oils are used to obtain followability and drop resistance. In Japanese Patent Application Laid-Open No. 07-61187, a solid material is used in combination to improve the drop impact resistance, and a gel-like material having a good fluidity ensures the followability to the ink. Both inks have excellent fluidity, that is, inks with both high follow-up properties and drop impact resistance by increasing the storage elastic modulus of the entire system by combining those with high loss elastic modulus and those with high impact resistance. It is an invention of a follower. However,
These use ink followers that have low viscosity and flow easily, and thus have the above-mentioned problem, that is, they are very weak against oil separation.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a low-viscosity ink having a low ink viscosity that guarantees a high degree of ink followability required for an ink follower for a water-based ballpoint pen in which ink is directly contained in an ink reservoir. Another object of the present invention is to provide an ink follower gel which is difficult to release oil. The gel-like material of the present invention functions effectively even when used alone as it is.However, in order to make the most of the property of obtaining a stable viscoelasticity with very little oil separation, even a strong drop impact affects writing performance. Absent,
JP-A-06-328890 and JP-A-07-6118
It is recommended to use it as a low-viscosity gel-like substance of the ink follower found in No. 7 etc.

[0008]

The inventors of the present invention have conducted intensive studies on the above-mentioned problems, and as a result, a gel-like substance having low viscosity and a base oil having low viscosity have a plurality of mechanisms. By adding viscoelasticity and interfering with each other, they found that it was more difficult to release oil than when used alone, and completed the present invention.

The ink follower gel of the present invention is non-volatile or non-volatile (hereinafter simply referred to as non-volatile).
In, low-viscosity base oil selected from water-insoluble organic solvents,
An extremely fluid gel characterized by pseudoplastic viscosity imparted by two or more thickeners, which can be used alone or in combination with a solid or viscous gel. Used as a follower.

[0010] The use of two or more thickeners for gelling hardly volatile solvents has not been denied at all. More specifically, JP-A-61-145269, JP-A-61-151289, JP-A-62-50379, JP-A-63-6077, JP-A-04-202281, and JP-A-0-202281
JP-A-5-270192, JP-A-05-270193, JP-A-06-200235 and JP-A-08-2171 disclose combinations of hydrophobic silica and dextrin fatty acid esters, and JP-A-62-148587 disclose combinations of hydrogenated castor oil and hydrophobic silica. Are introduced as examples. In addition, expressions such as "one or more thickeners" are also found in the text.

However, from the standpoint of designing a low-viscosity ink follower, there is a tendency that a simpler and simpler ink follower is desired. This is because, in the case of troubles such as oil release and interference with the ink, the cause is easier to understand as a simple system, and because of the low viscosity, a large amount is not required as a total addition amount. . In fact, except for the above case, almost 1
Only thickeners are used. Furthermore, dextrin fatty acid esters are thickeners that once restructured and lose their viscosity unless reheated and cooled again, and are rather special thickeners that cannot withstand single use. In this sense, the combination of hydrogenated castor oil and hydrophobic silica disclosed in Japanese Patent Application Laid-Open No. Sho 62-148587 is an example in which a thickener having a thickening ability is used alone or in combination. It is about 7500 mPa · sec at ° C., and it is presumed that the design will be based on the drop impact resistance and the like from the ink follower intended by the present inventors.

The present invention is directed to an ink follower gel which is particularly concerned with the ability to follow the ink, in order to cope with recent special inks which have a large amount of ink flowing out. In order to improve the followability to the ink, the viscosity of the base oil may be reduced, and the pseudoplasticity may be further reduced. However, in this case, two problems emerge. One is drop impact resistance. The present invention is not concerned with this matter. JP-A-06-328890 and JP-A-07-61187 are excellent inventions as means for improving the impact resistance of an ink follower, and are sufficient methods for improving the drop impact resistance of the present invention. Another is oil release. As described above, even in the world of lubricating grease, oil release is more likely to occur as the viscosity becomes lower, and the ink follower did not break through the common sense at all.

An object of the present invention is to minimize the oil separation. The principle of the present invention, in short, utilizes steric hindrance between thickeners. Therefore, even if a thickener is simply used in combination, the principle differs depending on the combination. Inorganic fine particles having a primary particle size of 50 nm or less, such as fine particle silica, ultrafine aluminum oxide, and ultrafine titanium oxide, impart pseudoplasticity and structural viscosity to the liquid by chain-like secondary aggregation. In the clay thickener, the flat surface of the plate-shaped thickener has a negative charge and the end face has a positive charge, and the thickener is connected vertically and horizontally to obtain structural viscosity. This is called a card house structure. In the metal soap, the lipophilic group of the soap molecule and the metal salt released by heating are entangled in a wide range while attracting each other, and they become steric hindrance to each other to increase the viscosity.

For example, the dispersed inorganic fine particle thickener is
Fine particles that have become uniform throughout have a loose chain structure.
Eventually, the chain structure gradually grows, subsides under the influence of gravity, and becomes a large local mass. At this point, a sense of non-uniformity in viscosity appears and the particles adhere to the ink storage tube in a granular manner, or the oil release reflects on the performance of the ballpoint pen. However, if the card house structure of the clay thickener exists as a steric hindrance, the chain structure is appropriately divided, and conversely, the card house structure is hindered by the fine particle chains, and the local structure is not obtained as a complete structure. Continue to exist without bias.

The interaction between the particulate thickener and the clay thickener is:
It is conceptually easy to understand, and for that reason, it is the most effective in the present invention. If the clay thickener is changed to metal soap, the card house structure will interfere with the inorganic fine particle chains as a fiber-like structure due to the lipophilic base of moderately entangled soap, and if the fine particle chains become metal soap, . It is a fibrous structure of lipophilic base and metal salt separated from the card house.

The gel material used in the present invention is designed so that the viscous response (loss modulus) exceeds the elastic response (storage modulus) (ie, tan δ> 1). Therefore, it is necessary to pay attention to the addition of the gel. If the thickener used in the present invention is added too much, it will exhibit strong consistency. Specifically, the BET specific surface area is 50 to 200.
Fine-grained silica such as about 〓 / g, similar ultra-fine alumina and ultra-fine titanium oxide, organically treated clay such as dimethyldioctadecyl ammonium bentonite, and commonly known thickeners such as lithium and aluminum soaps have some differences. It is a value close to the addition amount. Even if two or more are added, the total amount should not exceed 6%. If it exceeds 6%, the tracking ability will be poor,
When a ballpoint pen is used, it may prevent ink from flowing out. Furthermore, a total viscosity of 4% or less gives a preferable viscosity. However, when the total amount is less than 1.5%, the oil separation becomes remarkable although the effect is seen as compared with the case where the viscosity is increased alone.

Since the gel-like ink follower of the present invention has better fluidity than ordinary ones, the base oil has good followability with the ink at 25 ° C. unless the viscosity exceeds 5 Pa · sec. There is no loss of line quality. Further, if the base oil is 3 Pa · sec or less, it can sufficiently follow the ink consumption of more than 400 mg per 100 m of the drawn line. Therefore, the viscosity of the base oil of the gel material used in the present invention is 3 Pa · sec or less at 25 ° C., preferably 2 Pa · sec.
It can be said that the viscosity is Pa · sec or less, and the viscosity is not too low. The solvent used as the base oil is polybutene,
Examples include mineral oils such as liquid paraffin and spindle oil, and silicone oils such as dimethylpolysiloxane and methylphenylpolysiloxane. These may be used alone or in combination.

In the gel base oil used in the present invention, thickeners such as resins and rubbers can be used if necessary, but it is not preferable to use these in large amounts. This is because the elastic response of the gel-like material increases. If the elastic response of the gel is superior to the viscous response, impact such as dropping is once absorbed and dispersed in the gel.
That is, it exhibits excellent drop impact resistance. However, at the same time, it has an absorbing power against all external forces, and also absorbs the negative pressure due to the outflow of the ink, which hinders the outflow of the ink. In the present invention, impact such as dropping is based on the idea of absorbing and dispersing in a solid material serving as a nucleus, and the gel-like material does not need to have an impact absorbing ability. Therefore, the viscous response is superior to the elastic response from the low shear rate range to the high shear rate range so as not to hinder the outflow of the ink at all.

It is also an effective means to use a surfactant in order to improve the followability of the gel material used in the present invention with ink. Although the type of the surfactant is not limited, those which elute into the ink during storage over time are not preferable.
A nonionic surfactant having a (hydrophilic / hydrophobic balance) value of 4 or less is preferable. Furthermore, what is generally called a fluorine-based surfactant or a silicon-based surfactant is most preferable because it significantly lowers the surface tension of the base oil. The addition amount of the surfactant is from 0.01%, which is the minimum addition amount at which the effect is exhibited, to about 5% by weight at the maximum. 5% by weight
When used in excess of this, there is no problem in performance, but the effect of addition is completely meaningless.

The method for producing the gel material used in the present invention may be the same as that of the ink follower of the prior art. As an example,
When using inorganic fine particles and clay-based thickeners, all gel-like components such as all thickeners, base oils, and surfactants are pre-kneaded at room temperature, and then kneaded with a disperser such as a three-roll mill or kneader. A very simple way of doing so. When metal soap is used as the thickener, it has to be heated and kneaded at a high temperature of 200 ° C. or higher, and the surfactant must be added after cooling according to its heat resistance. When a clay thickener is used, the weight ratio of the clay thickener is 20% to 20%.
If 0% of lower alcohol is added on an out-of-box basis, it can be easily dispersed. If the lower alcohol added in this manner is removed during the working process, for example, in a three-roll mill, vacuum degassing, or the like, there is no adverse effect on the ink.

Next, the present invention will be described in detail with reference to examples.

(Gel A) Diana Process Oil MC-W90 (mineral oil; Idemitsu Kosan Co., Ltd.) 95 parts by weight Aerosil R-974D (hydrophobic silica; Nippon Aerosil Co., Ltd .; BET surface area 200 cm / g) 4 {KF 6015 (silicone surfactant; brand name of Shin-Etsu Chemical Co., Ltd.) 1} The above was kneaded three times with a three-roll mill to obtain gel-like material A.

(Gel-like substance B) Diana process oil MC-W90 95 parts by weight BETON 34 (organic treated bentonite: trade name of Wilba Ellis Co., Ltd.) 4 Ｋ KF 60151-1 メ タ ノ ー ル methanol 2 〃 Kneading twice or more with a three-roll mill Thus, a gel B was obtained. During the kneading of the three-roll mill, methanol was volatilized and was lost.

(Gel-like substance C) Diana process oil MC-W90 95 parts by weight Lithium stearate 4 に was weighed in a stainless steel beaker (3 l) and heated with stirring to 270 ° C with a mantle heater. After stirring at 270 ° C. for 10 minutes, the mixture was kneaded twice with a three-roll mill in which the temperature of the roll section was adjusted to 120 ° C. while the temperature was not sufficiently cooled, and allowed to cool. Then, 1 part by weight of KF 60151 was added. The mixture was kneaded once with a roll mill to obtain a gel C.

(Gel-like substance D) Polybutene 100H (Idemitsu Kosan Co., Ltd., trade name; MW = 960) 95 parts by weight Aerosil R-974D 4 {KF 6015 1} The above is kneaded three times with a three-roll mill, and gel-like substance D Got

(Gel-like substance E) Polybutene 100H 95 parts by weight BETON 344 {KF 60151-1} methanol 2} The above mixture was kneaded twice with a three-roll mill to obtain a gel-like substance E. During the kneading of the three-roll mill, methanol was volatilized and was lost.

(Gel-like substance F) Polybutene 100H 95 parts by weight Lithium stearate 4〃 was weighed in a stainless beaker (3 l), and heated with stirring to 270 ° C with a mantle heater. After stirring at 270 ° C. for 10 minutes, the mixture was kneaded twice with a three-roll mill in which the temperature of the roll section was adjusted to 120 ° C. while the temperature was not sufficiently cooled, and allowed to cool. Then, 1 part by weight of KF 60151 was added. The mixture was kneaded once with a roll mill to obtain a gel material F.

Example 1 Gel A 50 parts by weight Gel E 50% The above were mixed and kneaded once with a three-roll mill.
I got

(Example 2) Gel substance B 50 parts by weight Gel substance F 50% The above substances were mixed and kneaded once with a three-roll mill.
I got

(Example 3) Gel A 50 parts by weight Gel B 25 {Gel C 25} The above materials were mixed and kneaded once with a three-roll mill.
I got

Example 4 Gel A 25 parts by weight Gel E 25 {Diana Process Oil MC-W90 50} The above components were mixed and kneaded once with a three-roll mill.
I got

Example 5 Gel B 25 parts by weight Gel D 25 {Diana Process Oil MC-W90 50} The above components were mixed and kneaded once with a three-roll mill.
I got

Example 6 Diana Process Oil MC-W90 73.75 parts by weight BETON 341 Ｋ KF 6015 0.5 〃 Methanol 0.5 ポ リ Polybutene 100H 23.75 〃 Aerosil R-974D 1 ３ The mixture was kneaded four times with a roll mill to obtain Example 6.
During the kneading of the roll mill, methanol was volatilized and was lost.

Comparative Example 1 100 parts by weight of gel A was kneaded once with a three-roll mill to obtain Comparative Example 1.

Comparative Example 2 100 parts by weight of gel B was kneaded once with a three-roll mill to obtain Comparative Example 2.

Comparative Example 3 100 parts by weight of gel C was kneaded once with a three-roll mill to obtain Comparative Example 3.

Comparative Example 4 Gel Part D 100 parts by weight The above was kneaded once with a three-roll mill to obtain Comparative Example 4.

Comparative Example 5 25 parts by weight of gel-like material B 25 parts by weight of gel-like material D 25 {polybutene 100H 50} or more were mixed and kneaded once with a three-roll mill.
I got

Comparative Example 6 Diana Process Oil MC-W90 73.75 parts by weight BETON 342 {KF 6015 0.5} Methanol 0.5 {Polybutene 100H 23.75} The above mixture was kneaded four times with a three-roll mill. To obtain Comparative Example 6 3
During the kneading of the roll mill, methanol was volatilized and was lost.

As described above, Examples 1 to 5 and Comparative Examples 1 to 5 were evaluated by the following three tests. The base oil viscosity of each sample was determined by mixing polybutene and mineral oil in the same lot as the compounded mixture at the compounding ratio, and measuring the viscosity at 25 ° C. with an E-type viscometer manufactured by Toki Sangyo Co., Ltd. It was determined that the base oil had no shear thinning, and the value at which the load on the viscometer was as close to 50% as possible was taken as the measured value. Test 1 Stability over time -1 (oil separation test) Each of Examples 1 to 5 and Comparative Examples 1 to 5 was rubbed and removed in a 1-liter stainless beaker, taking care not to mix conspicuous bubbles, and ping-pong balls. A hole equivalent to half was drilled and left in a 50 ° C. constant temperature bath for one week, and it was confirmed that oil was accumulated in the hole. The evaluation is ○ for approximately 1 cc or less (less than 1.5 cc), and approximately 2 to 3 cc (1.5 cc).
cc or more and less than 3.5 cc), and な ら when it was about 4 cc or more (3.5 cc or more).

The aqueous ballpoint pen inks of Tests 2 and 3 were prepared as follows. PRINTEX 25 (Carbon Flack; trade name of Degussa) 7 parts by weight PVP K-30 (Polyvinyl Hydrolitone; manufactured by GAF) 3.5 glycerin 10 potassium ricinoleate 0.5 triethanolamine 1 1,2- Benzisothiazolin 3-one 0.2 {benzotriazole 0.2} water 27.2} After kneading the above with a bead mill, coarse particles of carbon black are removed and propylene glycol 20 parts by weight Carbopol 940 (crosslinked polyacrylic acid) BF Cut (trade name of Rich Co., Ltd.) 0.4 (water 30) was added to obtain an ink for a water-based ballpoint pen having a viscosity of 500 mPa · sec at 40 sec ^-1 .

Test 2 Stability over time-2 (pen body storage test) Ten each of Examples 1 to 5 and Comparative Examples 1 to 5,
The ballpoint pen shown in FIG. 1 was assembled. A translucent polypropylene tube with an inner diameter of 4.0 mm is used as the ink storage tube 7,
Predetermined ink 8 and ink follower 9 of each embodiment and comparative example
Was filled 20 mm. A commercially available ballpoint pen (UM-100 (Fri); Mitsubishi Pencil
The same ballpoint pen tip as that of (trade name) was mounted. The material of the ballpoint pen tip holder 3 is free-cutting stainless steel, and the ball 4 is tungsten carbide having a diameter of 0.7 mm. The assembled ball-point pen was left in a thermostat at 50 ° C. for 2 weeks with the pen tip facing upward, and the number of oils mixed in the ink was counted by silent gaze to obtain a score. Examples and Comparative Examples are 10 samples each,
0 points is the best and the lowest is 10 points.

Test 3 The sample evaluated in Test 2 was used at a speed of 4.5 m / s.
Spiral writing was performed at the speed of ec, and the ink follower was observed. Almost no adhesion to the inner wall of the ink storage tube, approx.
5 points following with an amount of mm or more, 3 points for 10-18 mm, 1 point for 3-10 mm, 0 for 3 mm or less
As points, 10 were totaled. The maximum score is 50 points, and the higher the score, the better, and the minimum is 0.

Table 1 shows the test results.

[0046]

[Table 1]

Although the test was prepared mainly by mixing gels using a single thickener, Examples 5 and 6 had exactly the same composition, and were originally mixed with a mixture of gels. It is a mixture of ingredients. The results were exactly the same, indicating no differences due to the formulation procedure. In Comparative Examples 1 to 4, the performance of each gel-like material used in the test as an ink follower alone was evaluated. Example 1 in which these were mixed and used
The result is remarkably inferior to that of # 6. It is obvious that stable performance is obtained by a synergistic effect when used in combination. In Comparative Example 4 and Comparative Example 5, no oil separation was confirmed. This is because the base oil viscosity is high. The high viscosity of the base oil is reflected in the poor followability of the ink in Test 3. In Comparative Example 6, the fine particle silica of Example 5 was replaced with a clay thickener to use only one thickener. The test results were the worst. The ability to follow the ink is zero because all the samples violently separated oil before the ink flow path was blocked, so that writing was impossible. Since the blending was slightly different because methanol was not used as an auxiliary, it was not described as a comparative example. However, almost the same results were obtained when the clay thickener was replaced with fine-particle silica.

For reference, polybutene, liquid paraffin, spindle oil, dimethyl silicone oil and methyl phenyl silicone oil were used as base oils, and Aerosil R-972, R-974D, R-976D and RY-2 were used as thickeners.
00, # 200, 380, 300, 100, OX50,
TITANIUM DIOXIDE P25, ALMINIUM OXIDE (Nippon Aerosil Co., Ltd. product name) BETON 27, 34, EW (Wilbaelis Company product name), Synthetic smectite SAN, SA
F, SWN (brand name of Corp Chemical Co., Ltd.) as additives such as fluorine-based, silicon-based, polyoxyethylene derivatives, glycerin / polyglycerin derivatives, sorbitan derivatives, phosphates and other surfactants, silane coupling agents, titanium-based Tests arbitrarily combining the coupling agents showed the same tendency as in the examples of the present application.

[0049]

As described above, the gel of the present invention has a
Even with an ink outflow exceeding 400 mg per 0 m,
It is an ink-follower gel having excellent stability and excellent stability, while not releasing oil even in a forced heating test.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a refill holder of an aqueous ballpoint pen using the ink follower of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 ink storage tube 20 ink 30 ink follower 40 joint between pen tip and ink storage tube 41 pen tip (ballpoint pen tip holder) 42 ball

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Miki Sugiyama 2-12-12 Irie, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsubishi Pencil Co., Ltd. Yokohama Office (72) Inventor Katsuhiko Shiraishi 2-chome Irie, Kanagawa-ku, Yokohama-shi, Kanagawa 5-12 Mitsubishi Pencil Co., Ltd. Yokohama Office

Claims (4)

[Claims] In an aqueous ballpoint pen which directly stores ink in an ink storage tube, the viscosity of a base oil at 25.degree.
Pa · sec or less, and the content of the thickener is 6% or less in total, and is at least different from the thickener consisting of the group of inorganic fine particle thickeners, clay thickeners, and metal soaps. An ink-follower gel containing two or more thickeners having a combination with a solid, and used alone or in combination with a solid having a specific gravity of 0.80 to 1.10. 2. When a strain rate of 10% to 200% is applied, 5%
In a gel having a shear rate of 〜3000 sec −1 or a tan δ of a shear frequency range corresponding thereto of greater than 1.0,
2. The ink follower gel according to claim 1, comprising at least one of each of an inorganic fine particle thickener and a clay thickener. 3. When a strain rate of 10% to 200% is given, 5
In a gel having a shear rate of 〜3000 sec −1 or a tan δ of a shear frequency range corresponding thereto of greater than 1.0,
At least 1 each of the inorganic fine particle thickener and the metal soap
2. The ink-follower gel according to claim 1, which contains seeds. 4. When a strain rate of 10% to 200% is given, 5
In a gel having a shear rate of 〜3000 sec −1 or a tan δ of a shear frequency range corresponding thereto of greater than 1.0,
The ink-follower gel according to claim 1, comprising at least one of each of a metal soap and a clay thickener.