Ink for ball-point pen and ball-point pen

Details Ink for ball-point pen and ball-point pen Ink for ball-point pen and ball-point pen

2002-06-14

2004-12-07

Klemanski, Helene (Department: 1755)

Compositions: coating or plastic

Coating or plastic compositions

Marking

C106S031270, C106S031590, C106S031600, C106S031890

Reexamination Certificate

active

06827767

ABSTRACT:

TECHNICAL FIELD
The present invention relates to ink for a ballpoint pen which is called medium viscosity ink, neutral ink, gel ink, aqueous gel ink or the like, and to a ballpoint pen using the ink for a ballpoint pen, more specifically the present invention relates to ink for a ballpoint pen which consumes much ink, that is, a ballpoint pen for writing thick and bold letters and a ballpoint pen using the ink for a ballpoint pen.
BACKGROUND ART
Various types of ballpoint pen have been proposed conventionally.
For example, there is provided a ballpoint pen filled with ink using water or an aqueous medium as a solvent and dye or pigment as a colorant. Hereinafter the ink is referred to as “aqueous ink” and the ballpoint pen as an “aqueous ballpoint pen.”
The aqueous ballpoint pen shows so low viscosity that it may advantageously write smoothly at low writing-pressure. On the other hand, however, it is likely to occur that, since the pen is weak to vibration or impact, the ink leaks from the point of pen-tip (hereinafter referred to as “direct flow”) and that the stability of the ink-flow rate decreases (hereinafter referred to as “fluctuating”) by the air involved from the point of the pen-tip. Further, the aqueous ballpoint pen also has a defect that lines written therewith tend to be blurred.
Meanwhile, there is also provided a ballpoint pen filled with ink using an organic medium as a solvent and dye or pigment as a colorant. Hereinafter the ink is referred to as “oil-based ink” and the ballpoint pen as an “oil-based ballpoint pen.”
Since the oil-based ballpoint pen uses highly viscous ink, it is free from above-mentioned defects as seen in the aqueous ballpoint pen. However, it has a defect that high writing pressure is needed for writing, resulting in a heavy writing feeling. Further, it also has a defect that it is likely to make the pen-tip and the paper surface dirty with ink blots (hereinafter referred to as “blotting”).
There has recently been provided a ballpoint pen filled with ink using water or a water-soluble medium as a solvent, dye or pigment as a colorant and, further, a pseudoplasticizing so that the ink may have pseudoplasticity. Hereinafter the of ink is referred to as “aqueous gel ink” and the ballpoint pen as an “aqueous-gel ballpoint pen.”
Here, pseudoplasticity is a property showing non-flowability in a static state and also showing flowability when a shearing force is applied.
The aqueous gel ink shows non-flowability in an ink reservoir as well as the oil-based ink while it shows flowability like aqueous ink near the point of the pen-tip where a shearing force is applied to the ink due to the rotation of the ball.
Accordingly, the aqueous-gel ballpoint pen has both the advantage of an aqueous ballpoint pen and that of an oil-based ballpoint pen. That is, the aqueous-gel ballpoint pen has advantages that it can write smoothly at a low writing pressure, that the lines written there with are hard to blur and that the blotting is less likely to occur.
Actually, however, the production of the aqueous-gel ballpoint pen is not so easy.
For example, a pen-tip containing a ball with a diameter of 0.5 mm and a pen-tip containing a ball with a diameter of 0.7 mm are different in the clearance between the ball and a holder as well as in the shearing force applied to the ink caused by rotation of the ball.
Therefore, if aqueous gel ink suitable for one of these two types of pen-tips is used for the other, the direct flow and fluctuating will occur or the blotting will occur.
Accordingly, the viscosity of the aqueous gel ink is adjusted in accordance with the pen-tip to be used.
Further, an aqueous-gel ballpoint pen with which relatively thick and bold letters (hereinafter referred to as an “aqueous-gel bold ballpoint pen”) can be written is desired recently.
The aqueous-gel bold ballpoint pen uses a ball with a diameter of 0.9 mm or more so as to be adapted for writing bold letters.
Further, the aqueous-gel bold ballpoint pen is formed to have a relatively large clearance between the ball and the holder since, only by enlarging the diameter of the ball, the written line, which can be wider, appears pale in color.
Moreover, the aqueous-gel bold ballpoint pen needs so much ink to be supplied to the pen-tip as to account for the amount according to wider lines due to the larger diameter of the ball and the amount according to the increase of the flow rate due to the larger clearance between the ball and the holder.
Specifically, ink should be supplied to the pen-tip so that the ink-consumption value per unit area may fall within a range on the order of 0.64 to 1.6 mg/cm
2
.
This ink consumption corresponds to as much as 1.5 to 3 times that of a conventional aqueous-gel ballpoint pen.
Here, the ink-consumption value per unit area means a value of the ink-consumption value per unit length which is divided by the line width.
For example, the ink-consumption value per unit length of an aqueous-gel bold ballpoint pen is preferably on the order of 300 to 750 mg/100 m. When the ink-consumption value per unit length is 300 mg/100 m or less, written lines appear pale in color. On the other hand, when the ink-consumption value per unit length is 750 mg/100 m or more, the ink transferred onto the paper surface will be harder to dry.
The line width by the ball with a diameter of 1.0 mm, though it may vary due to the quality of paper, is on the order of 0.47 mm when written on the writing test paper in compliance with ISO standard 14145-1.
Accordingly, the ink-consumption value per unit area of an aqueous-gel bold ballpoint pen is on the order of 0.64 to 1.6 mg/cm
2
.
Actually, however, the preparation of the ink for an aqueous-gel bold ballpoint pen is very difficult.
For example, when ink suitable for a pen-tip with a ball with a diameter of 0.5 mm is used for a pen-tip with a ball with a diameter of 1.0 mm, the blotting and a phenomenon that a written line splits into plural lines (hereinafter referred to as “line splitting”) is likely to occur due to the larger clearance between the ball and the holder becomes and to the less shearing force applied to the ink caused by rotation of the ball.
In addition, the amount of ink flow from the point of the pen-tip increases in the aqueous-gel bold ballpoint pen, and consequently the ink transferred onto the paper surface becomes harder to dry.
Further, since the amount of ink flow from the point of the pen-tip becomes unstable in such an aqueous-gel bold ballpoint pen due to a storage environment and to a writing condition, there occurs a wide variation in the density and width of the written lines.
DISCLOSURE OF THE INVENTION
Accordingly, the object of the present invention is to provide ink for a ballpoint pen to be used in an aqueous-gel bold ballpoint pen as described above which is unlikely to cause blotting or line splitting, which is excellent in quick drying property when transferred onto the paper surface and which is unlikely to cause fluctuation in the density and width of the written lines due to a storage environment and to a writing condition.
Further, the object of the present invention is to provide an aqueous-gel bold ballpoint pen as described above which is unlikely to cause blotting or line splitting, which is excellent in quick drying property when transferred onto the paper surface and which is unlikely to cause fluctuation in the density and width of the written lines due to a storage environment and to a writing condition.
The present inventors have made intensive studies to achieve the above-described objects and found that a ballpoint pen formed to have an ink-consumption value per unit area of 0.64 to 1.6 mg/cm
2
, when the surface tension of the aqueous gel ink to be used is adjusted to a range of 16 to 32 mN/m, is unlikely to cause blotting and line splitting. They also found that the ink transferred onto the paper surface therewith is excellent in quick drying property and that the density and the width of the lines written therewith are unlikely to vary due to a storage environment and to a writing cond

Affiliated with

Also associated with

Rating

Ink for ball-point pen and ball-point pen does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Ink for ball-point pen and ball-point pen, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink for ball-point pen and ball-point pen will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3285990