JP3142235B2 - Ballpoint pen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball-point pen using oil-based ink for writing by transferring ink adhered to the peripheral surface of a ball onto a paper surface or the like by rotating the ball. More specifically, the present invention relates to an oil-based ballpoint pen using a medium-viscosity oil-based ballpoint pen ink whose viscosity has been reduced in order to obtain a lighter and smoother writing taste than conventional oil-based ballpoint pens, or an oil-based ballpoint pen ink provided with shear thinning.

[0002]

2. Description of the Related Art Conventionally, various inventions and improvements relating to a ballpoint pen for obtaining beautiful handwriting with good writing have been made in various ways. These have evolved in a complex way.

[0003] First, a high viscosity (20,000 mPa.s) called an oil-based ink prepared by adding a resin or the like to a dye or a pigment and dissolving the dye or pigment in an aqueous ink prepared by dissolving a fountain pen dye in water. Before and after) Ballpoint pens made with ink are water-resistant and have strong handwriting, and even when the cap is off, the ink dries slowly, so you can write out quickly. In addition, you can write long distances with less ink and write with high pressure. In addition to its writing performance advantages, such as being able to be manufactured, it can be manufactured at low cost, thereby establishing its position as an office writing instrument. Indeed, even if you drop water on the document, the handwriting does not disappear, the ink does not dry and you can write immediately without fitting the cap, so it can be adapted to the place where you work busy, and it can be used for a long time with less ink, so it is light and compact The exterior is obtained, and it can be written with high writing pressure, so it is suitable for copying slips. It is cheap, so it can be placed anywhere and it can be used casually, and it has a good evaluation.

However, oil-based ballpoint pens made of high-viscosity ink also have disadvantages. One of the drawbacks is that the ink is transferred to the paper by rotating the ball. The other is that the lips are squeezed and cry at the edges, and the bosses are generated. The other is that the writing is heavy and the writing must be performed with a high pen pressure. Many people have neck and shoulder arm disease.
In response to this situation, ballpoint pens made of low-viscosity water-based ink that can write smoothly with light writing pressure and obtain clear handwriting first appeared, and initially ink was applied to the batting of plastic fibers stored in the ink storage cylinder. It is a batting-type water-based ballpoint pen that transmits ink to the ball via an ink relay core that binds plastic fibers so that the capillary action works more strongly than the batting, but the ink holding capacity is smaller than the size of the ink storage cylinder On the contrary, since the ink consumption is 4 to 5 times as large as that of the oil-based ball-point pen, a direct liquid type water-based ball-point pen having the following dissatisfaction with the expensive feeling of having a short writing life in spite of being expensive was born. In other words, the ink is stored directly in the barrel, and a pen core with an ink discharge adjustment mechanism is interposed between the tip and the ballpoint pen tip. The barrel is formed of a transparent material and the remaining amount of ink is seen through. While improvements are being made, it is possible to write with a ballpoint pen tip without using a costly pen core. Even viscous aqueous inks have emerged.

[0005] However, although writing instruments having the same ballpoint pen tip, a tough oil-based ballpoint pen that can withstand high writing pressure and a water-based ballpoint pen that pursues a delicate writing feel used at low writing pressure are incompatible. When used as a ballpoint pen, an oil-based ballpoint pen has an image with poor writing feel, and a water-based ballpoint pen has a dissatisfaction that writing with high writing pressure hasten the damage of the ballpoint pen tip and makes it impossible to write even though there is a considerable amount of ink remaining Become.

Therefore, the conventional oil-based ballpoint pen ink has a viscosity of 20,000 mPa.s. Attention has been paid to the point of lowering the ink viscosity so that a smooth writing feel can be obtained with a light touch from those prepared before and after the s, and attempts have been made to give a good writing feeling and durability to the ballpoint pen. However, on the actual writing surface, the writing mechanism that transfers ink to the paper surface by rotating the ball is the same, so the ink not transferred to the paper surface is squeezed at the tip edge of the chip,
Crying and bottling are still occurring. In Japanese Patent Publication No. 5-64120, Japanese Patent Application Publication No. 5-64120 discloses a method for preventing the occurrence of crying, bleeding, and improving ink followability. Discloses a method of manufacturing a ball-point pen tip having two optimized gaps, wherein a second gap is formed simultaneously between the caulked portion positioned slightly below the first gap and the ball peripheral surface. . The first void portion of the manufacturing method prevents crying and dents, and the second void portion has an effect of improving ink followability. However, the first void portion is too large and is plastically formed at the same time. On the other hand, the gaps have become too small, so that crying and the occurrence of dents can be prevented, but the relationship that results in poor ink followability has been awaited. Therefore, it is important for the conventional high-viscosity oil-based ballpoint pen tip to balance the first gap and the second gap to provide two optimized gaps. However, it is actually incompatible with the ink whose viscosity has been reduced, so that the ink crying and rubbing may occur.

[0007]

Problems to be Solved by the Invention and Means for Solving It
The inventor of the present invention does not give up even in the state of the prior art, and realizes an oil-based ball-point pen with beautiful handwriting that is durable even with a light touch, durable in high-pressure writing, dries, and has no dents. As a result of repeated studies, the chip produced by the method described in Japanese Patent Publication No. 5-64120 was crying and causing bleeding. The cohesive force of the ink was also reduced due to the decrease in the viscosity of the ink, and the remaining residue was not transferred to the paper. The ink was not found to be uniformly diffused into the first void portion, but was found as a phenomenon that caused a local overflow, causing tears and tearing. In other words, in the case of high-viscosity ink, the residual ink was uniformly diffused in the gap so as to be pulled by the ink in the first gap, and it was confirmed again that the cohesive force of the ink was acting. It is.

According to the present invention, with respect to the state in which the overflow occurs locally, the method of caulking the tip edge of the ball-point pen tip holding the ball is reduced, the caulking angle at the tip of the tip is reduced, and the first gap is reduced. through trial and error by a new experimental attempt to increase the opening angle, the viscosity of the B-type viscometer 20rpm at 20 ℃ 2,000~1
000 mPa. In the case of using a medium-viscosity oil-based ink which is s, it has been found that by setting the swaging angle at the foremost portion of the swaging portion to 40 ° to 50 °, crying and boring are eliminated and the ink followability is also good. . Fortunately, the decrease in the second void portion did not result in a loss of ink followability within the scope of the present invention because the fluidity of the ink was improved due to the decrease in the viscosity of the ink.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ball-point pen having an ink storage cylinder containing ink and a metal ball-point pen tip fitted into a tip end hole of the ink storage cylinder, wherein the ink is a B8H-HH type ink at 20.degree. The viscosity of the viscometer HH-2 rotor at 20 rpm is 2,000 to 10,000 mPa.s.
s There is oil-based inks, the cutting edge portion caulking angle of the caulking portion metal ballpoint pen tip to be caulked inwardly tip edge for holding the ball used to at least 40 ° 5
The angle is set to less than 0 °, and a required gap is formed between the foremost portion of the caulked portion and the peripheral surface of the ball. Thus, using a medium-viscosity oil-based ink, the ballpoint pen tip can be caulked in combination, and the present invention is intended to provide a light touch, smooth writing taste, and durability for high pressure writing. Moreover, in addition to beautiful handwriting without crying and rubbing, good ink followability was obtained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to drawings and tables showing examples.

The inks used in Examples and Comparative Examples of the present invention are prepared as follows. A Combination B Combination Nigrosine EX (manufactured by Orient Chemical) 30.0% by weight 30.0% by weight Hilac 111 (ketone resin manufactured by Hitachi Chemical) 4.0% by weight 10.0% by weight Oleic acid 5.0% by weight 5.0% by weight Phenyl glycol 48.5% by weight 43.9% by weight Benzyl alcohol 12.0% by weight 11.0% by weight PVP K-120 (manufactured by GAF) 0.5% by weight 0.1% by weight First, phenyl glycol, benzyl alcohol, and oleic acid were weighed, heated to 60 ° C., added with Hilac 111, stirred and dissolved, and then PVP K-120 was added with stirring to completely dissolve. Finally, nigrosine EX was added while stirring so as not to leave a residue, and after completion of the addition, the mixture was heated and stirred for 2 hours to completely dissolve nigrosine to prepare a black oil-based ballpoint pen ink. The viscosity of this ink at 20 ° C. was measured at a rotation speed of 20 rpm using a B8H-HH type viscometer HH-2 rotor. s, B blend about 2
000 mPa. s.

[0012] Figure 1 is an enlarged longitudinal sectional view of the tip end portion shape used in Examples 1 and 2 and Comparative Example 4 shown in Table 1 of the Examples and Comparative Examples, the tip outer periphery of the metal chip 1 The surface 1a is formed by an inclined surface having an angle of about 30 °, and the tip end edge thereof is inwardly caulked at a caulking angle θ1 of 44 ° to 48 ° to hold the ball 2, and the uppermost surface of the caulked portion 1b is formed. A required gap 1c is formed between the tip and the peripheral surface of the ball. FIG. 2 is an enlarged vertical cross-sectional view of the tip end portion shape of Example 3 and Comparative Examples 1 to 3, wherein tip end swaging for holding the ball is performed by setting the tip end swaging angle θ1 to 5;
The first caulking is performed at 0 ° to 70 °, and then the caulking angle θ2 is applied to the top side bordering the outer peripheral surface of the tip by the first caulking.
The second caulking is performed at 44 ° and the foremost portion of the caulking portion is opened, and the caulking portion 1b is formed in two steps. In this way, gaps of different sizes are formed between the tip end of the caulked portion of each chip and the peripheral surface of the ball. These chips are filled with the ink 4 (formulation A and composition B) prepared as described above into the ink container 3 and then fitted into the tip hole 3a to form a ballpoint pen refill R (see FIG. 3). A writing performance test by handwriting was performed after the ballpoint pen was completely loaded, and the results are shown in Table 1.

[0013]

[Table 1]

In the writing performance test results, in Examples 1 to 3 in which the first caulking angle θ1 of the caulked portion 1b is 50 ° or less, no ink bleeds out at the tip of the chip, and no good dents are found on the handwriting and good handwriting is obtained. In Comparative Examples 1 to 3 in which the first swaging angle was 55 ° or more, it was confirmed that as the first swaging angle was increased, the degree of crying was increased and the handwriting was stained. In Comparative Example 4, the same chip as in Example 1 was used, but the ink used was a high-viscosity B-blended ink, so that the ink followability at low temperatures was poor.

As described above, the present invention relates to
The viscosity of the H-HH type viscometer HH-2 rotor at 20 rpm is 2,000 to 10,000 mPa.s. s using a medium-viscosity oil-based ink 4 and setting the tip end swaging angle θ1 of the tip edge swaging portion 1b holding the ball 2 by the ballpoint pen tip 1 to 40 ° or more and less than 50 °. If the angle is less than 40 °, there is a concern that the ball holding power may be insufficient. If the angle is more than 55 °, the ink may cry, the ink may be burned, and good handwriting may not be obtained. Although the viscosity of the oil-based ink used in the present invention has been specified, it is also possible to naturally give the ink a shear thinning viscosity in order to prevent the ink from leaking from the tip of the chip. Such an ink for ballpoint pen with shear-thinning viscosity contains a wax-based thickener such as a fatty acid amide in the ink.
So-called shear-thinning substances such as metallic soap-based thickeners, inorganic and organic fine particles such as bentonite, smectite and aerosil, polysaccharide-based gums, and polymer-based thickeners such as acrylic acid and acrylate esters. Can be prepared by adding

[0016]

According to the present invention, the oil-based ink whose viscosity is reduced to a medium viscosity is used, and a ballpoint pen tip specification adapted to the ink is established, thereby providing a cap-off rich in water resistance and handwriting robustness. It has excellent writing performance even when the condition is continued for a long time, can write over long distances with a small amount of ink, and has the characteristics of a ballpoint pen using oil-based ink that does not cause performance degradation even when writing at high pressure. It provides a ballpoint pen that is suitable for office use and provides a smooth writing feel that can be written with writing pressure and a clear handwriting that is clear and free of dirt.

[Brief description of the drawings]

FIG. 1 is a partially enlarged longitudinal sectional view showing a ballpoint pen tip shape in which a caulking portion is only a tip portion.

FIG. 2 is a partially enlarged longitudinal sectional view showing a ball-point pen shape in which a caulking portion is caulked in two steps.

FIG. 3 is a longitudinal sectional view of a ballpoint pen refill used for a handwriting performance test.

[Description of Signs] 1 Ball-point pen tip 1a Tip outer peripheral surface 1b Caulked portion 1c Void 2 Ball 3 Ink cylinder 4 Ink R Ballpoint pen refill θ1 Foremost portion swage angle (first swage portion) θ2 Second swage angle

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-309571 (JP, A) JP-A-1-299880 (JP, A) JP-A-8-11476 (JP, A) JP-A-3-309 23021 (JP, A) JP-A-7-68989 (JP, A) JP-A-8-52978 (JP, A) JP-B 5-64120 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) A43K 1/08

Claims (1)

(57) [Claims] 1. A ball-point pen having ink stored in an ink container and a metal ball-point pen tip fitted into a tip end hole of the ink container, wherein the ink has a viscosity of 2 rpm at 20 ° C. with a B-type viscometer at 20 rpm. 000-10,00
0 mPa. b. The ink for a ball-point pen, wherein the ball-point pen tip has a swaging angle of 4 at the foremost end of the swaging portion whose tip edge is swaged inward to hold the ball.
A ballpoint pen characterized by being at least 0 ° and less than 50 °.