JPH0241151Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is installed in the ink cylinder of a writing instrument such as a ballpoint pen or felt-tip pen, and prevents ink from flowing backwards toward the end of the ink cylinder, or by scattering ink from the end of the ink cylinder due to backflow. The present invention relates to a backflow prevention device for an ink cylinder of a writing instrument, which prevents the occurrence of backflow.

[Conventional technology]

Conventionally, a ballpoint pen, a type of writing instrument, is a plastic or metal pen with an open end, made of ink made by dissolving dye in a non-volatile liquid such as hexylene glycol or benzene alcohol, and with a nib at the tip. The ink cylinder is filled with the ink. Although these inks are quite viscous, the ink may flow backwards due to impact and scatter from the end of the ink cylinder. For this reason, as shown in Figure 1,
An extremely viscous grease-like material 4' is filled at the end of the ink cylinder 2' so that its end surface contacts the end surface of the ink 3'.

However, these grease-like substances 4' have a large change in fluidity due to temperature changes, and become too hard at low temperatures, making it difficult to move within the ink cylinder as the amount of ink decreases, thus hindering the smooth flow and outflow of ink. Furthermore, at high temperatures, the ink softens and becomes more fluid, causing the ink to scatter even with a weak impact and cause the ink to flow backwards.

In order to improve this drawback, dibenzylidene sorbitol was dissolved in, for example, polypropylene glycol (average molecular weight 2000), or an amino acid derivative (for example, Ajinomoto Co., Ltd., Amisoft GP-1) was dissolved and gelled in liquid paraffin. Research has been conducted on preventing ink from scattering by filling the end of the ink cylinder with a backflow preventive agent that is free-flowing at high temperatures and gels at room temperature but does not lose its fluidity. There is.

However, these gelled backflow prevention agents may be destroyed by strong impact, causing the ink to flow back and scatter.

The present invention combines a gelling backflow prevention agent that is easy to flow at high temperatures and gels at room temperature but does not lose its fluidity with a network structure to provide impact resistance and create a better backflow prevention device. The purpose is to provide

[Means for Solving the Problems] The present invention impregnates a network body capable of impregnating liquid with a backflow preventive agent consisting of a gelling agent and a solvent that dissolves the gelling agent in an easily flowing state at high temperatures. After that, the ink is allowed to cool and gel, forming a backflow prevention device for an ink cylinder of a writing instrument.

[Effect]

According to the configuration of the present invention, a gel-like backflow preventive agent that is less likely to be deformed or deteriorated due to changes in temperature;
In combination with the network structure, it exhibits great impact resistance, so there is no risk of it being destroyed even by strong impact, and it has an even better backflow prevention effect. Also,
Since it has a network structure as its skeleton, it has an excellent backflow prevention effect even in large-diameter ink cylinders.

〔Example〕

With reference to FIG. 2, details of the present invention will be explained using a ballpoint pen as an example.

Reference numeral 1 denotes a ballpoint pen tip, which is molded by brass cutting or plastic injection molding, and has a ball 11 rotatably housed at its tip.

Reference numeral 2 denotes an ink cylinder tightly fitted into the small diameter portion 12 at the inner end of the ballpoint pen tip 1, and is made of metal or plastic. 3 is ink filled in the ink cylinder 2. Note that the ink 3 may be either oil-based or water-based.

4 is a backflow prevention device attached to the end of the ink cylinder 2 with its end surface in contact with the end surface of the ink 3; It consists of a network body 41 and a backflow prevention agent 42 impregnated into the network body 41 and gelled. The backflow prevention agent 42 is made of a gelling agent and a solvent that dissolves the gelling agent, as shown in Example 1 or 2 below. Note that the solvent for dissolving the gelling agent is selected to be incompatible with the ink.

(Example 1) Gelol 0.6% by weight (trade name, gelling agent manufactured by Shin Nippon Chemical Co., Ltd., dibenzylidene sorbitol) Polypropylene glycol 99.4% by weight (manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 2000) (Example 2) Gelol D 1.0% by weight Olive oil 99.0% by weight The network body 41 is a material that can be impregnated with liquid, that is, in the present invention, it is a material that can be impregnated with the backflow prevention agent 42 under easy-flowing conditions, such as coarse hair, etc. Fiber bundle/
A network structure such as polyurethane foam or sintered resin powder is used.

This backflow prevention device 4 is formed, for example, by the following process, and is attached to the ink cylinder 2. That is, first, at the end of the ink cylinder 2 filled with the ink 3,
The mesh body 41 is inserted so as not to come into contact with the ink 3. Next, the backflow preventive agent 42, which has been made free-flowing by heating, is impregnated into the network structure 41 by means such as press-fitting, and then left to cool at room temperature.
1 to gel. Then, the obtained backflow prevention device 4 is brought into contact with the end surface of the ink 3, and the ink cylinder 2 is
will be installed on the

[Effect of idea]

Since the backflow prevention device 4 of the present invention has the above-described configuration, it is less likely to be deformed or deteriorated due to changes in temperature, and has great impact resistance, so it will not be destroyed even by strong impact. It has no fear and exhibits excellent backflow prevention effects. Moreover, if the outer diameter of the network body 41 is made slightly smaller than the inner diameter of the cylinder body 2,
In addition to the backflow prevention effect, the backflow prevention device moves more smoothly as the amount of ink decreases, and has the effect of keeping the ink outflow constant. In addition, since the skeleton is a network structure, it has an effect that can be applied to a large diameter ink cylinder. Furthermore, the backflow prevention device of the present invention can be applied to writing instruments such as felt-tip pens and fountain pens in addition to ballpoint pens.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional ballpoint pen ink barrel.
FIG. 2 is a longitudinal sectional view of a ballpoint pen ink barrel using the backflow prevention device according to an embodiment of the present invention, and FIG. 3 is an enlarged sectional view of the backflow prevention device. 4... Backflow prevention device, 41... Network tissue body, 4
2...Anti-reflux agent.

Claims (1)

[Scope of utility model registration request] A writing instrument ink that is obtained by impregnating a liquid-impregnable network with a backflow preventive agent consisting of a gelling agent and a solvent that dissolves the gelling agent in an easily flowing state at high temperature, and then allowing it to cool and gel. Cylinder backflow prevention device.