JP4363178B2 - Ink container - Google Patents

Description

  The present invention is an ink container that contains an ink absorber that is directly impregnated with ink or impregnated with an ink in a writing instrument such as a ballpoint pen, a sign pen, a marker, a fountain pen, a small tube pen, and a correction tool. It relates to members.

  Conventionally used for writing instruments such as ballpoint pens, sign pens, markers, fountain pens, small-tube pens, and applicators such as correction tools, and contains ink directly inside or contains an ink absorber impregnated with ink. As the ink containing member, members such as a shaft cylinder, a pen tip holder, an ink containing cylinder, and a tail plug are known.

For example, in order to make the state of the ink visible from the outside, a shaft that accommodates the ink is formed of transparent polypropylene (see Patent Document 1), not only transparency but also airtightness is obtained. In addition, a member in which a member such as a shaft cylinder is formed of polyethylene terephthalate so as to suppress ink loss is known (see Patent Document 2).
JP 2001-310593 A Japanese Patent Application Laid-Open No. 07-149093

  In the case where the shaft cylinder containing the ink is formed by the transparent polypropylene as disclosed in Patent Document 1, the state such as the remaining amount of ink and the color can be visually recognized from the outside. There is. However, the polypropylene resin has relatively large pores between communicating molecules, and easily allows gas molecules such as oxygen, nitrogen, carbon dioxide, and hydrogen to pass through. For this reason, it is easy to reduce the amount of ink stored, and in the case of a writing instrument or applicator that compresses the gas inside and seals and stores it, and supports the discharge of ink by this compressed gas, leave it for a long time. When this is done, pressure is gradually released from the inside of the shaft cylinder to the outside, and the ink discharge cannot be supported by the pressure, causing problems such as ink smearing and ejection failure.

  In the case where a member such as a shaft cylinder is formed of polyethylene terephthalate as disclosed in Patent Document 2, the molecule is deformed because polyethylene terephthalate has a double bond portion in its molecular structure. It was difficult to perform, lacked in flexibility, easily broken against stress, and cracked. That is, when the container material is used, cracks are likely to occur due to stress such as press-fitting or fitting, and if the ink leaks from the cracked part or is filled with compressed gas, the gas This causes a problem that the ink leaks out and causes defective ink and poor ink discharge.

The present invention provides an injection of polybutylene terephthalate in which a ball holder for rotatably holding a ball is connected to the tip end of a member formed by extrusion molding of polybutylene terephthalate having at least an inner wall portion that is transparent. The front shaft, which is a molded product, is connected by press-fitting, and the tail plug, which is an injection-molded product of polybutylene terephthalate, is connected to the rear end by press-fitting, together with a compressed gas that is in a compressed state higher than atmospheric pressure, The gist is an ink containing member that contains methylcyclohexane as a main solvent and hermetically contains a correction liquid ink in which a white pigment such as titanium oxide is dispersed .

  Since the ink containing member is formed of polybutylene terephthalate having at least an inner wall portion having transparency, the pores between the communicating molecules are small, and the passage of gas molecules such as oxygen, nitrogen, carbon dioxide, and hydrogen is allowed to pass. Suppress. Therefore, a writing instrument and an applicator that are transparent and have a reduced weight loss due to evaporation of the stored ink are compressed as much as possible. Even when left for a long period of time, the release of pressure from the inside of the shaft cylinder to the outside is suppressed, and ink smearing and ejection defects are suppressed as much as possible. In addition, the molecular skeleton is flexible and easily deformed, and the ink containing member can suppress cracking by stress such as press-fitting or fitting.

  The present invention is an extremely efficient and reliable method for evaporating ink in a writing instrument or applicator that contains ink directly in a free state or contains an ink absorber impregnated with ink. In particular, with respect to those that are compressed and sealed in a gas, and those that support the ejection of ink by this compressed gas, the pressure release is suppressed, and there is a risk of scumming during the use of writing instruments and applicators. It is possible to suppress discharge defects such as.

Hereinafter, an example will be described with reference to the drawings.
The one shown in FIG. 1 has a high viscosity of 700 mPa · s (B-type viscometer No. 3 rotor, 60 rpm, 25 ° C.) in which methylcyclohexane is used as a main solvent and a white pigment such as titanium oxide is dispersed. This is an example of a correction applicator in which the correction liquid ink 1 is directly stored in the shaft 2. The shaft 2 is an extruded product of polybutylene terephthalate having transparency, and the ink 1 is directly accommodated in the shaft 2.

A front shaft 3 that is an injection-molded product of polybutylene terephthalate is connected to the tip of the shaft 2. Further, a ball holder 5 on which a ball 4 is rotatably held is connected to the front end opening of the front shaft 3. The ball 4 is urged forward by a coil spring 6 and functions as a valve that controls the discharge of the ink 1 by liquid-tightly contacting the inner edge of the ball holder 5. The ball holder 5 is press-fitted and connected to the front end opening of the front shaft 3 so that the strength is 42.5 kg / cm ² . This is to prevent the ball holder 5 from coming off and the ink 1 from being scattered outside due to the pressure of the compressed gas 7 filled in the shaft 2, which will be described later. The connection method is not limited to press-fit connection, and includes adhesive, heat, ultrasonic waves, welding by vibration, and the like, and can be appropriately performed in consideration of productivity, hermeticity, and durability.

  A follower 8 is disposed that contacts the interface of the ink 1 in the shaft 2 and moves following the movement of the interface of the ink 1 as the ink 1 is consumed. The follower 8 is an injection-molded product of a polyester-based thermoplastic elastomer having a bottomed cylindrical shape and a hardness of 65 ° (Duroe hardness type A), and is colored yellow so that the ink 1 is not mistaken for white. Has been. Of course, it may be a color having a different brightness or color tone, such as black.

  The rear end opening of the shaft 2 is sealed with a tail plug 9 which is an injection-molded product of polybutylene terephthalate, and the space between the tail plug 9 and the follower 8 has a pressure state higher than atmospheric pressure of 130 kPa to 270 kPa. Compressed gas 7 is filled. The pressure by the compressed gas 7 supports the ejection by pushing the ink 1 from behind via the follower 8. Further, in order to prevent the tail plug 9 from being pushed up and removed by the compressed gas 7, it is connected to the rear end opening of the shaft 2 by press-fitting so that the strength becomes 42.7 kg / cm 2. . The connection method of the tail plug 9 is not limited to the press-fit connection as in the case of the front shaft 3 and the ball holder 5 described above, and can be appropriately performed in consideration of productivity, hermeticity, and durability.

Since the shaft 2 used in this example is polybutylene terephthalate having transparency, the remaining amount of the ink 1 stored directly in the shaft 2 can be visually observed. In addition, the pores between the communicating molecules of polybutylene terephthalate are small and the gas permeability is low at about 100 cc / m ² day / 25 μm · 23 ° C./O _2. It is possible to suppress the pressure and maintain the pressure for supporting the ink discharge. Moreover, since the pores between the molecules are small, the weight loss due to evaporation of the stored ink 1 can be suppressed as much as possible. In addition, since polybutylene terephthalate does not have a double bond portion in the molecular structure, the molecule is easily deformed and has high flexibility against stress. For this reason, even if it is the stress by the press injection with the comparatively strong intensity | strength in which the front shaft 3 and the tail plug 9 do not remove | deviate to the shaft 2 with the compressed gas 7, it does not produce a crack of a connection part, but the ink 1 from a junction part. And the outflow of the compressed gas 7 can be suppressed.

  In addition to this example, it is formed of a polybutylene terephthalate having transparency, and is an ink container that can suppress pressure change due to permeation of gas, reduction of ink 1, and cracking of the connection part of the ink container. For example, the compressed gas 7 may be injected by a pumping operation from the rear end of the shaft 2, for example. In addition, the compressed gas 7 for assisting the discharge is not required, the liquid is discharged at a water head pressure, and a high-viscosity follower fluid that follows the consumption of the ink 1 is disposed at the interface of the ink 1. Water-based dye inks and pigments that have a relatively low viscosity, for example, water as a main medium, such as those in which a temporary ink reservoir member for pressure adjustment is provided, or in which an ink occlusion body is impregnated with ink 1 Can be used with ballpoint pens, sign pens, markers, fountain pens, small tube pens, etc., using inks and oil-based inks with organic solvents as the main medium.

The longitudinal cross-sectional view which shows an example.

Explanation of symbols

1 ink 2 shaft 3 front shaft 4 ball 5 ball holder 6 coil spring 7 compressed gas 8 follower 9 tail plug

Claims (1)

This is an injection molded product of polybutylene terephthalate in which a ball holder that rotatably holds a ball is connected to the tip end of a member formed by extrusion molding of polybutylene terephthalate having at least an inner wall portion that is transparent. The front shaft is connected by press-fitting, and the tail plug, which is an injection molded product of polybutylene terephthalate, is connected to the rear end by press-fitting. An ink containing member containing a correction liquid ink in which a white pigment such as titanium oxide is dispersed as a solvent .

Images