JP2003191680A - Ballpoint pen - Google Patents

Abstract

(57) [Summary] [Problem] A ballpoint pen equipped with a ballpoint pen tip rotatably holding a writing tip ball and filled with oil-based ink has clear handwriting, good writing, bleeding, strikethrough, dripping. Provide a ballpoint pen without going down. Kind Code: A1 A color pen, an organic solvent, a non-Newtonian viscosity-imparting agent, and an aliphatic alcohol having 4 or less carbon atoms are provided. Having a non-Newtonian viscosity index of 0.4 to 0.9 and a viscosity at a shear rate of 500 sec ^-1 of 500 to 5000 mPa.s. A ballpoint pen filled with an oil-based ink for a ballpoint pen having a temperature of S (20 ° C.), and when the ball diameter is X, the ink consumption per 100 m Y (mg) satisfies Y ≧ 60X.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ballpoint pen filled with oil-based ink.

[0002]

2. Description of the Related Art Conventionally, a coloring agent, a solvent such as ethylene glycol monophenyl ether, which is a solvent having a high boiling point and a low vapor pressure, has been used as an oil-based ink for a ball-point pen having a ball-point pen tip rotatably holding a writing tip ball. ,
Contains alcohols such as benzyl alcohol and has an ink viscosity of 10,000 to 30,000 mPa.
Those composed of s (20 ° C.) are well known. In a ballpoint pen filled with such an oil-based ink, the ink consumption amount per 100 m at the time of writing is, for example, about 10 when the diameter of the writing tip ball is φ0.5 mm.
In the case of mg, φ0.7 mm, about 20 mg, φ1.0 m
In the case of m, it was about 30 mg. That is, the ball diameter is X mm, and the ink consumption amount per 100 m is Y (m
In the case of g), the relationship of Y ≦ 30X is general, and Y <35X even when the ink consumption amount is set to be large.

However, since the oil-based ink has a high ink viscosity, the ball rotation resistance at the time of writing naturally increases, and the writing feel is very heavy and not good. However, if you simply reduce the ink viscosity, the writing quality will be good, but there will be the problem that the dryness of the handwriting will decrease, and there will be a problem that sagging will occur, and as a result, The reality was that he sacrificed writing quality.

To solve these problems, Japanese Patent Laid-Open Nos. 6-313143, 6-313144, 7-196972, and 9-48 are available.
According to Japanese Patent Publication No. 941 etc., the ink viscosity characteristic is pseudoplastic,
A new ink has been proposed which has a low ink viscosity when written and a high viscosity when not written.

[0005]

However, even if the ink viscosity characteristic is pseudoplastic, in the ballpoint pen filled with the oil-based ink as described above, as described above,
Since the ink consumption amount Y (mg) per 00 m is small (Y <35X when the ball diameter is X), there is the effect of suppressing the sagging and improving the writing feeling, but the point of sharpness of the handwriting There was a part that I was not satisfied with.

Therefore, as a result of various investigations, the inventor increased the ink consumption amount per 100 m: Y (mg) in order to obtain the sharpness of the handwriting, and as a result of various investigations, the relationship between the outer diameter of the writing tip ball: X and Y was obtained. It has been found that a clear handwriting can be obtained by setting ≧ 60X.

However, although the ink consumption amount can be increased and a high-density handwriting can be obtained due to the clearance of the ballpoint pen tip, the conventional oil-based ink having a high-boiling point solvent has a problem as described above. As the amount of consumption increases, new problems such as blurring of handwriting, strike-through on the paper surface, and poor dryness of handwriting occur. That is, ink consumption per 100 m: Y (m
By setting g) to Y ≧ 60X, clearer handwriting can be obtained, but problems such as blurring of handwriting and strike-through on the paper surface occur.

In view of these problems, the present invention has a ballpoint pen tip that rotatably holds a writing tip ball and is filled with an oil-based ink. It provides a ball-point pen that does not come off or drip.

[0009]

Means for Solving the Problems The present invention provides "1. A colorant, an organic solvent, a non-Newton viscosity imparting agent, and an aliphatic alcohol having a carbon number of 4 or less, and a non-Newton viscosity index of 0.4 to 0.9. And a shear rate of 500 s
Viscosity at ec ⁻¹ is 500 to 5000 mPa · s
(20 ° C.) oil-based ink is filled, and the ball diameter of the writing tip ball of the ballpoint pen tip is X (mm) 10
An ink consumption amount Y (mg) per 0 m is in a relation of Y ≧ 60X. 2. Ink consumption amount per 100 m where the ball diameter of the writing tip ball of the ballpoint pen tip is X (mm) Y
(Mg) has a relationship of 200X ≧ Y ≧ 60X, The ball-point pen according to item 1, wherein 3. The ball-point pen according to the first or second aspect, wherein the diameter of the ball is φ1.0 mm or less. 4. The aliphatic alcohol having 4 or less carbon atoms is contained in an amount of 5 to 50% by mass with respect to the total amount of the ink.
The ballpoint pen according to any one of items 1 to 3. 5. The ink viscosity at a shear rate of 500 sec ⁻¹ is
It is 1,000-3,000 mPa * s (20 degreeC), The ball-point pen of any one of the 1st thru | or 4 characterized by the above-mentioned. It is.

As a method of calculating the ink consumption amount per 100 m in the present invention, a method according to ISO12757-1 is used.

Ink viscosity is C
Using an LS rheometer, the cone plate angle and diameter are adjusted to appropriate values at a shear rate of 1 to 60 in a measurement environment of 20 ° C.
It was measured in the range of ⁰ sec ⁻¹ . The non-Newtonian viscosity index (n) is an empirical formula (T = Kj ⁿ : K) obtained from the rheological measurement by a viscometer of the shear stress value (T) and the shear rate value (j) obtained by the CLS rheometer. , And n are calculated constants).

The first feature of the present invention is that the amount of ink consumed per 100 m is Y (mg) in order to obtain a sharp handwriting.
However, the ball diameter of the writing tip ball of the ballpoint pen tip is X
(Mm), the relational expression of Y ≧ 60X is satisfied.

It is well known that the sharpness of handwriting is improved by increasing the ink consumption, but when Y <60X,
We cannot obtain satisfactory handwriting sharpness. On the other hand, it is also true that the handwriting dryness decreases as the ink consumption increases, and when Y> 200X, the handwriting dryness tends to decrease due to the large ink consumption. In consideration of the fact that the total writing distance of the ballpoint pen decreases as the ink consumption increases, 200X ≧ Y ≧ 60X
It is preferable that The total writing distance referred to here is the writing distance when writing is performed until the oil-based ink of the ballpoint pen is used up.

The second characteristic is that the ink composition has 4 carbon atoms.
It is to contain the following aliphatic alcohols.

As described above, in order for the handwriting to be clear, the ink consumption amount per 100 m: Y (mg) is Y ≧ 6 when the ball diameter of the writing tip ball is X (mm).
Ink consumption that satisfies the relational expression of 0X is required,
In an ink composition containing a conventional high-boiling solvent such as ethylene glycol monophenyl ether or benzyl alcohol, it is impossible to prevent bleeding and strike-through even if an ink viscosity modifier is contained due to vapor pressure. .

In order to solve this drawback, the ink composition contains an aliphatic alcohol having a carbon number of 4 or less so that the evaporation power is increased and when the ink composition is drawn on the paper, it is instantaneously evaporated and dried to increase the viscosity. However, it has been found that the blurring of handwriting and strike-through on the paper surface are prevented. The content of the aliphatic alcohol having 4 or less carbon atoms is preferably 5 to 50 mass% with respect to the total amount of the ink. If it is less than 5% by mass, a sufficient evaporation effect cannot be obtained, and handwriting blurs and strike-through occurs on the paper surface.
Poor handwriting dryness. On the other hand, if it is more than 50% by mass, not only the desired ink viscosity is difficult to obtain, but also the evaporation power becomes large and the writing performance becomes poor. Examples of the aliphatic alcohol having 4 or less carbon atoms include methanol, ethanol, n-butanol, s-butanol, t-butanol, n-propanol and the like. Ethanol, n-butanol, and n-propanol are preferable.
These may be used alone or in combination.

The third characteristic is that the shear rate is 500 sec-1.
The viscosity at is 500 to 5,000 mPa · s.

When the ink viscosity is less than 500 mPa · s,
Although the writing feeling is good, even if an aliphatic alcohol having a carbon number of 4 or less is contained, it is not possible to prevent handwriting from blurring and strike through to the paper surface. On the other hand, when it is more than 5,000 mPa · s, the writing feeling is not good, and the dryness of the handwriting tends to decrease.

The fourth characteristic is that a non-Newtonian viscosity-imparting material is added to the ink composition to obtain a non-Newtonian viscosity index of 0.4.
It is to be set to 0.9.

As described above, the ink viscosity at the time of writing, that is, at the time of high shear is set to be low in order to obtain a good writing feeling, so that the possibility of ink leakage is inevitably increased. In addition, to increase the ink consumption per 100 m,
It is necessary to widen the gap between the ball and the tip, that is, to increase the opening area of the tip, and ink leakage cannot be prevented only by the evaporation force of the aliphatic alcohol having 4 or less carbon atoms. In order to solve this drawback, a non-Newtonian viscosity-imparting agent is contained in the ink composition so that the ink viscosity characteristic becomes pseudoplastic and the ink viscosity when the ballpoint pen is not used is as high as possible. When the non-Newtonian viscosity index is 0.4 or less, poor follow-up occurs, resulting in line breakage, breathing, and handwriting blur. On the other hand, when it is 0.9 or more, sufficient viscosity at rest cannot be obtained, and it is impossible to prevent sagging.

The non-Newtonian viscosity imparting agent used in the oil-based ballpoint pen ink of the present invention is a fatty acid amide wax and its derivative, a cross-linked poly-N-vinylacetamide, a linear fatty acid ester polymer, a polyethylene oxide, hydrogenated castor oil, and an organic bentonite. , Silica, sulfate ester-based surfactants, cross-linked acrylic acid polymers and the like, but fatty acid amide wax and cross-linked poly-N-vinylacetamide are preferable from the viewpoint of stability.

As the coloring material used in the present invention, a dye and / or a pigment is used. As the dye, alcohol-soluble dyes, oil-soluble dyes, direct dyes, acid dyes, basic dyes, metal-containing dyes, and various salt-forming dyes that have been conventionally used in oil-based ballpoint pens can be used. Examples of the pigment include organic, inorganic and processed pigments such as carbon black, phthalocyanine type, azo type, quinacridone type, quinophthalone type, slene type and triphenylmethane type. These colorants may be used alone or in combination of two or more. The content is preferably 5 to 40 mass% with respect to the total amount of the ink composition.

The organic solvent is used as a solvent and a dispersion medium for the ink component. Specifically, benzyl alcohol,
Alcohols and glycols such as propylene glycol and butylene glycol, glycol ethers such as ethylene glycol monophenyl ether, and nitrogen-containing solvents such as N-methylpyrrolidone can be used. These may be used alone or in combination of two or more. The content ratio is preferably 10 to 60 mass% with respect to the total amount of the ink composition.

Examples of the ink viscosity modifier include phenol resin, maleic resin, amide resin, xylene resin, hydrogenated rosin resin, ketone resin, terpene resin and butyral resin. These are also effective as a fixing agent for paper, a fixing agent, and a pigment dispersant. These may be used alone or in combination of two or more.

In addition, a spinnability imparting agent can also be employed in a timely manner in order to improve crying and swelling performance. Examples of additives include polyvinylpyrrolidone, polyethylene oxide, hydroxypropyl cellulose, rubber-based polymer compounds, and the like. These may be used alone or in combination of two or more. As other additives, surfactants, rust preventives, dispersants, lubricants, dye dissolution stabilizers and the like can be selected and added at appropriate times.

Further, in the present invention, in order to make the handwriting clear, the ink consumption amount per 100 m: Y (mg), and the ball diameter of the writing tip ball is X (mm), Y ≧ 6.
It is one of the important requirements to have ink discharge that satisfies the relational expression of 0X, but when the ball diameter is 1.0 mm or less, the total ink consumption is small and it is difficult to express the sharpness of handwriting. Therefore, the effect is particularly remarkable.

[0027]

Embodiment 1 As shown in FIG. 1, a ballpoint pen of an embodiment of the present invention has a ballpoint pen tip 3 in which a ball 4 having a diameter of 0.7 mm is rotatably held at the tip of an ink containing cylinder 2. Of a general structure in which the ball-point pen refill 1 containing the following oil-based ink 6 is housed in a shaft cylinder (not shown) while being mounted via a chip holder 5. It is a thing. In this embodiment, for the sake of convenience, the ball-point pen tip is mounted on the ink containing cylinder via the tip holder, but it may have a structure without the tip holder. Further, in the present embodiment, the coil spring for pressing the ball against the inner wall of the tip end edge of the ball is not arranged at the rear end of the ball, but it is preferable to dispose the coil spring because the suppression of drooping is improved.

The oil-based ink 6 first employs benzyl alcohol and ethylene glycol monophenyl ether as an organic solvent, weighs a predetermined amount of the organic solvent and heats it to 60 ° C., and then uses a disper stirrer to prepare a fatty acid amide wax. Thalene BA600 (manufactured by Kyoeisha Chemical Co., Ltd.) was uniformly dispersed and swollen. Next, oleic acid was used as a lubricant, and polyvinylpyrrolidone K was used as a spinnability imparting agent.
-90 (manufactured by Wako Pure Chemical Industries, Ltd.) is used as a coloring agent for dye-based Spiron Black GMH-Special (manufactured by Hodogaya Chemical Co., Ltd.) and Varifast Violet 1.
Two types of 701 (manufactured by Orient Chemical Industry Co., Ltd.) were completely dissolved and naturally cooled to room temperature to obtain a black base ink. On the other hand, ethanol is adopted as an aliphatic alcohol having 4 or less carbon atoms, a predetermined amount of this is weighed, and Hirac 110H (Kitato resin manufactured by Hitachi Chemical Co., Ltd.) is used as an ink viscosity adjusting agent (oil-soluble viscosity adjusting resin) at room temperature. ) Was completely dissolved using a Disper stirrer, and this was added little by little to the black base ink using the Disper stirrer and stirred at room temperature for 1 hour to obtain an oil-based ink. The specific compounding amount is as follows.

[0029]   18.0% by mass of aliphatic alcohol (ethanol) having 4 or less carbon atoms   Organic solvent (benzyl alcohol) 8.0% by mass   Organic solvent (ethylene glycol monophenyl ether) 14.7% by mass   Fatty acid amide wax (Tarlen BA600) 1.2% by mass   Coloring agent (Spiron Black GMH-Special) 15.0% by mass   Coloring agent (Varifast violet 1701) 15.0% by mass   Lubricant (oleic acid) 1.0% by mass   Ink viscosity modifier (Hirac 110H) 27.0 mass%   Spinnability imparting agent (polyvinylpyrrolidone K-90) 0.1% by mass

Examples 2 and 3 In the same manner as in Example 1 except that the aliphatic alcohol having 4 or less carbon atoms of the oil-based ink was as shown in Table 1, the oil-based ink was obtained and filled in the ink containing cylinder, and the operation was performed. A ballpoint pen was obtained in the same manner as in Example 1.

Example 4 A pigment was added as a colorant for an oil-based ink, uniformly dispersed in the ink, butyral resin was used as a viscosity adjusting resin, and each ink composition was compounded as shown in Table 1. An oil-based ink was obtained in the same manner as in Example 1 and filled in an ink container, and a ballpoint pen was obtained in the same manner as in Example 1.
As a pigment, Printex 140V (manufactured by Degussa)
It was adopted. Butyral resins include PVB BX-
L (manufactured by Sekisui Chemical Co., Ltd.) was adopted.

Examples 5 and 6 Examples were carried out except that two or more kinds of aliphatic alcohols having 4 or less carbon atoms of the oil-based ink were blended as shown in Table 1 and each ink composition was blended as shown in Table 1. An oil-based ink was obtained in the same manner as in Example 1 and filled in an ink container, and a ballpoint pen was obtained in the same manner as in Example 1.

Example 7 Crosslinked poly (N-vinylacetamide) was added as described in Table 1 as a non-Newtonian viscosity imparting agent for oil-based inks,
An oil-based ink was obtained in the same manner as in Example 1 except that the respective ink compositions were blended as described in Table 1, and the ink was filled in the ink containing cylinder, to obtain a ballpoint pen in the same manner as in Example 1. As a cross-linked poly-N-vinylacetamide, Rheogic GX
205 (manufactured by Nippon Pure Chemical Co., Ltd.) was adopted.

Examples 8 and 9 A ballpoint pen similar to that of Example 1 or 2 was obtained, except that a ballpoint pen tip rotatably holding a ball having a diameter of 1.0 mm was attached.

Examples 10 and 11 The same ballpoint pens as those of Examples 1 and 2 were obtained except that a ballpoint pen tip rotatably holding a ball having a diameter of 0.5 mm was attached.

Table 1

Comparative Example 1 The same as Example 1 except that the oil ink of Example 1 was not added with ethanol, which is an aliphatic alcohol having 4 or less carbon atoms, and the other composition was as shown in Table 2. Then, an oil-based ballpoint pen ink was obtained and filled in an ink container, and a ballpoint pen was obtained in the same manner as in Example 1.

Comparative Example 2 The same procedure as in Example 1 was carried out except that the oil ink of Example 4 was not added with ethanol, which is an aliphatic alcohol having 4 or less carbon atoms, and the other composition was as shown in Table 2. To obtain an oil-based ink, which was filled in an ink container, and a ballpoint pen was obtained in the same manner as in Example 1.

Comparative Example 3 Ink for an oil-based ballpoint pen was prepared in the same manner as in Example 1 except that the non-Newtonian viscosity-imparting agent was not added to the oil-based ink of Example 1 and the other composition was as shown in Table 2. Was obtained and filled in an ink container, and a ballpoint pen was obtained in the same manner as in Example 1.

Comparative Examples 4 and 5 In the oil-based ink of Example 1, an oil-based ballpoint pen ink was obtained in the same manner as in Example 1 except that the composition of each ink composition was as shown in Table 2. A ball-point pen was obtained in the same manner as in Example 1 by filling the tube.

Comparative Example 6 A cross-linked poly (N-vinylacetamide) was added as a non-Newtonian viscosity-imparting agent, and each ink composition was blended as shown in Table 2 to obtain an oil-based ballpoint pen ink and filled in an ink container. A ballpoint pen was obtained in the same manner as in Example 1. Rheozic GX205 (manufactured by Nippon Pure Chemical Co., Ltd.) was adopted as the crosslinked poly-N-vinylacetamide.

Comparative Examples 7 and 8 A ballpoint pen similar to that of Example 6 or 2 was obtained except that a ballpoint pen tip rotatably holding a ball having a diameter of 1.0 mm was attached.

Comparative Examples 9 and 10 A ballpoint pen similar to that of Example 1 or 2 was obtained, except that a ballpoint pen tip rotatably holding a ball having a diameter of 0.5 mm was attached.

Table 2

Test Method and Evaluation The ballpoint pens of Examples 1 to 11 and Comparative Examples 1 to 10 were evaluated by the following tests. 1. Writing feeling (in handwriting) It is possible to write with low writing pressure and it is smooth and particularly good …… ◎ Good is …… ○ Somewhat inferior …… △ It is not possible to write with low writing pressure and there is no feeling of slippage …… It was set as ×. 2. Bleeding (during handwriting) Very good ones that do not occur at all …… ◎ Things that do not matter in practical use …… ○ Some things that are annoying …… △ Very something that annoys me …… × . 3. Strikethrough: Very good ones that do not occur at all in handwritten writing .... ◎ Those that do not bother you in practical use .... ○ Somewhat worrisome .... △ Very worrisome. . 4. Writing sharpness: After 100 m writing, the handwriting is visually confirmed. Those with vivid ink colors and clear handwriting …… ○ Those with light ink colors and not clear handwriting were marked with ×. 5. Handwriting dryness: Immediately after writing, press the paper with 500 gf for 1 minute, and the transfer formation is not observed .... ○ Transfer formation is recognized, but it is not of practical use. △ Transfer The formation was recognized, and what was very worrisome was ....

The evaluation results of each Example and Comparative Example are as shown in Tables 1 and 2. Since Comparative Examples 1 and 2 do not contain an aliphatic alcohol having a carbon number of 4 or less, sufficient evaporative power cannot be obtained for the handwriting immediately after writing, the drying property is poor, the ink penetrates into the paper, and the handwriting bleeds and strikes through. Was not good.

In Comparative Example 3, the non-Newtonian viscosity-imparting agent was not contained, so that the drooping could not be prevented.

In Comparative Example 4, since the ink viscosity at 500 sec-1 hour is high and the ball rotation resistance becomes strong, the writing feeling is not good. Further, the evaporation of only the surface of the ink transferred by writing proceeds, and the ink inside the handwriting is not dried, so that the handwriting dryness is not good.

In Comparative Example 5, since the ink viscosity was too low, the bleed-through was not satisfactory even when the aliphatic alcohol having a carbon number of 4 or less was evaporated.

In Comparative Examples 6 to 10, since the ratio of the ink consumption amount (Ymg) per 100 m to the ball diameter (X) was small, there was no bleeding, strike-through, or drooping, but the ink color was thin and the handwriting was clear. It wasn't.

[0051]

As described above in detail, in a ballpoint pen in which a ballpoint pen tip rotatably holding a writing tip ball is mounted and oil-based ink is filled, the handwriting is clear, the writing feel is good, and the blurring is good. We were able to provide a ballpoint pen that does not show through or hang down.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a ball-point pen of the present invention.

[Explanation of symbols]

1 ballpoint pen 2 Ink storage cylinder 3 ballpoint pen tip Four balls 5 chip holder 6 Oil-based ballpoint pen ink

Claims (5)

[Claims] 1. A non-Newtonian viscosity index of 0.4 to 0.9, containing a colorant, an organic solvent, a non-Newtonian viscosity imparting agent, and an aliphatic alcohol having 4 or less carbon atoms, and a shear rate of 5
Viscosity at 00 sec ^-1 is 500 to 5,000 mP
The ink consumption Y (mg) per 100 m in which the ball diameter of the writing tip ball of the ballpoint pen tip is X (mm) filled with an oil-based ink of a · s (20 ° C.) is Y ≧ 6.
A ballpoint pen characterized by having a relationship of 0X. 2. The ink consumption amount Y (mg) per 100 m in which the ball diameter of the writing tip ball of the ball-point pen tip is X (mm) has a relationship of 200X ≧ Y ≧ 60X. 1. The ballpoint pen according to 1. 3. The ball-point pen according to claim 1, wherein the diameter of the ball is 1.0 mm or less. 4. The aliphatic alcohol having 4 or less carbon atoms,
The ball-point pen according to any one of claims 1 to 3, wherein the ball-point pen contains 5 to 50 mass% of the total amount of the ink. 5. The ballpoint pen according to claim 1, wherein the ink viscosity at a shear rate of 500 sec ⁻¹ is 1000 to 3000 mPa · s (20 ° C.).