JPH10236064A - Writing implement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop sufficiently the function of a counterflow prevention mechanism by higher viscosity ink using a coloring agent having a large grain size by making the minimum cross sectional area of an ink passage the same or larger than the pen flow path cross sectional area and projection cross sectional area of a pen tip, and setting it smaller than a specific value of the ink flow path cross sectional area of the pen tip. SOLUTION: Ink is produced using a scale aluminum powder of an average grain diameter of 0.3-3m, having a shearing reduction viscosity of 100-500cp during the high shearing period and 200-20000cp during the low shearing period regarding ink viscosity at 23 deg.C. As such, the minimum projectile cross sectional area G of a flow path f the check mechanism is made the same or more than the projection cross sectional area of a writing ball, and the minimum projection cross sectional area G of the check mechanism is made having a smaller dimension than 50 times the ink flow path cross sectional area S of the pen tip because of no resistance in the flow of ink. The check mechanism is effective in its operation, and an operational retardance of the check mechanism can be prevented through the agency of volatility of the pen tip part, as a result, preventive operations of thinning or counterflow can be expected by an interaction with the ink flow path.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has a pen point which is a writing portion, and often causes a problem in a writing instrument or a writing instrument-like container for storing a liquid such as ink directly in an ink storage tube. This is an improvement related to a writing implement having a backflow prevention mechanism for preventing so-called backflow which prevents ink from flowing to the rear end side when not writing or when the pen tip is turned upward, and leaks from an air hole. The present invention relates to an improvement for sufficiently exhibiting a backflow preventing effect and preventing an internal mechanism from being deformed and destroyed during assembly.

[0002]

2. Description of the Related Art Conventionally, in a writing instrument or a container for cosmetics or the like similar to a writing instrument, a liquid such as ink (hereinafter referred to as ink) is absorbed into a fiber bundle called batting, and a pen tip is utilized by utilizing a difference in capillary force. Many mechanisms have been used to derive ink.However, since the remaining amount of ink is large, ink cannot be seen, and the ink flow rate is large at the beginning, there are drawbacks such as thinning with use. Various types of writing implements that have only a mechanism and directly store ink in an ink storage tube have been invented and marketed. However, with this type of direct storage of ink, if the pen tip is stored for an extended period of time, or if it is vibrated, or if it is written upward, ink called backflow leaks from the air hole at the rear end, making writing impossible. It is known that there is a problem of soiling clothes. In order to solve this, some inks have a high viscosity of 5000 cp or more, and a grease-like follower is further provided at the rear end, but these are not fundamental solutions, and a backflow prevention mechanism and Inventions such as a combination of a ball and a valve, and a combination of a spring and a ball to be written (Japanese Utility Model 4-52067, Japanese Utility Model Application Laid-Open No. 6-68887).
4, Japanese Utility Model Application Laid-Open No. Hei 7-28675, and Japanese Patent Laid-Open No. Hei 7-237386). These inventions are already commercially available as products and inventions for improving their development.In recent years, gold, silver, and pastel inks have been dispersed with a pigment-based colorant having a large particle size such as metal powder and inorganic substances. However, these inks must use a relatively large colorant having a particle size of about 0.3 μm to 3 μm in order to secure the color development of the particles. In order to pass through and to disperse large particles, it is necessary to use an ink with a higher viscosity than other general colors,
In some cases, there has been a problem that it is difficult to derive the ink. However, if the flow path is extremely large, the backflow will stop, but the volume of the check mechanism and the movement of the check ball will take time, causing a large amount of air to enter the tip of the pen tip, causing problems. There is a problem that the sensitivity of the mechanism operation in the backflow prevention mechanism becomes dull, and the flow path of the check mechanism is weak or lacks chemical resistance during centrifugal defoaming. There has also been a problem that the check mechanism is easily destroyed during manufacturing.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention is mainly aimed at improving a popular writing instrument, and not only solves the problem of ink backflow, but also has the problem of writing property in combination with various inks. In addition, a water-based ink that has recently been marketed, has a lower viscosity than the ink used in ordinary oil-based ballpoint pens, and a medium-viscosity type direct liquid ballpoint pen with a higher viscosity than the batting water-based ink has been launched. However, these inks have a medium viscosity and are easy to move when ink is used, and air easily enters the pen tip due to the shock during storage or movement, and the backflow prevention mechanism has a sufficient function. Solved the problem of air entrapment in the pen tip and the problem of the backflow prevention mechanism with a slightly higher viscosity ink using a large particle colorant until it is fully activated. Provide a writing instrument that does not become a complicated mechanism in consideration of assemblability and performance stability, that is inexpensive and does not cause backflow or fraying. To provide a writing implement that does not cause problems in writing properties and backflow prevention performance even when the ink flow path is deformed due to swelling, cracking, and when the pen tip is dry,
To solve the problem.

[0004]

To achieve the above object, there is provided a writing implement or a writing implement-like cosmetic which has a pen tip as a writing section and directly stores a liquid such as ink in an ink storage tube. Therefore, the writing implement of the present invention focuses on the projected cross-sectional area S of the ink flow path of the pen tip and the minimum cross-sectional area G of the flow path of the backflow prevention mechanism, and determines the minimum cross-sectional area G of the flow path of the pen-tip ink flow path. The area was set to be equal to or more than S and smaller than 50 times S. The check mechanism has a groove or a protrusion that can secure a flow path when the check ball is loosely fitted inside the joint and the check ball moves to the pen tip side, and the check ball is provided at the rear end side. When the ink moves, there is a mechanism to block the ink flow path by the seal surface in the joint to prevent backflow, and to form a seal surface on the rear end of the pen tip by loosely fitting a check ball into the pen tip. The writing ball is pressed from the back with a check mechanism that is narrowed down to the writing ball, or a ball-point pen-type writing tool that loosely fits the ball that is the writing part of the pen tip between the swaged part at the tip and the receiving seat that has the ink channel behind By doing this, a spring tip type that prevents backflow by closing with the inner side wall of the tip side and the writing ball when writing is not performed, or has a check ball with a front end instead of a ball and a seal surface at the rear end The reverse of the material, which is much heavier than the ink Such as those with the frame is available. Further, in the case of inks such as gold and silver, since a colorant having a large average particle diameter of 0.3 to 3 μm is used in the ink, the viscosity of the ink in the ink of these large particles is reduced by another. It is necessary to make it slightly higher than the pigment ink or the dye ink, and in these cases, the resistance of the flow of the ink inside has a great effect, so it is very difficult to configure the flow path of the check mechanism of the present invention. It is valid.
In order to prevent the pen tip from drying and increasing the viscosity due to drying, a less volatile solvent than water is used as an auxiliary solvent in the ink.In the present invention, the viscosity of the ink is lower than that of water. One or more high solvents were incorporated in a total amount of 3% to 40%. When a joint provided between the tip of the pen tip and the rear end of the ink storage tube is used, the material of the joint can be made of synthetic resin to form the ink flow path and the seal portion of the check mechanism. The material of the resin is not only the base resin component, but also more heat-resistant and chemical-resistant than the base component.
Metal powders such as aluminum, copper, and metal whiskers, or inorganic substances such as glass, carbon, and talc, or polyphenylene ether, polyamide, polycarbonate, polyester, fluorine, and polyimide, which are excellent in at least one of the three rigidity items. And 3% to 70% of an organic material such as an engineering plastic (including a super engineering plastic).

[0005]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 3 show a first embodiment of the present invention. As shown in the figure, it is a writing implement for storing ink inside an ink storage tube made of transparent or translucent resin, and is a direct liquid type refill containing aqueous medium viscosity ink. A medium viscosity ink with shear thinning called pseudoplasticity and a grease-like follower that hardly evaporates behind the refill and a PP or P having a specific gravity almost equal to that of the follower so as to float on the follower
A chip that holds a writing ball, which is a writing part, has a built-in follower rod made of resin such as E, and the writing ball is prevented from falling inside by a circumferential caulking part, and the writing ball is freely rotatably loosely fitted. The inside of the pen tip has a flow path necessary for writing. A joint is press-fitted into the tip end of the ink storage tube, and a receiving protrusion having an ink introduction groove having a cross section as shown in FIG. 2 is provided substantially at the center of the inside, and ink is guided to the pen tip by the groove of the receiving protrusion. . A seal piece is press-fitted and fixed to the rear inside of the joint, and a tapered seal surface is formed on the seal piece, and a non-return check fit is loosely fitted in a valve chamber formed between the seal surface and the groove of the receiving projection. During normal writing, a ball is used to communicate from the ink storage section to the ball that will be the writing section, and in the upward direction, the non-return ball is in close contact with the seal surface, blocking the ink flow path and preventing ink movement. This is a ballpoint pen having a backflow prevention mechanism having a structure that prevents backflow.

The ink used here is a medium-viscosity ink and a scale-like aluminum powder having a mean particle size of 0.3 to 3 μm when converted into spheres as a colorant such as gold or silver at 23 ° C. Ink viscosity from 100 to 500c at high shear
p, an ink having a shear thinning viscosity of 200 to 20,000 cp at low shear. Even if the ink has a relatively high viscosity as a medium-viscosity ink having such large particles, the minimum projected cross-sectional area G of the flow path of the check mechanism is set to the projected cross-sectional area S of the writing ball so as not to cause resistance to ink flow. It is set to be equal to or more than. In addition, if the minimum cross-sectional area G of the check mechanism is too large, it takes a long time for the check ball to contact the seal surface and close when the cover is turned upward, and the ink around the check mechanism section becomes ineffective. The minimum cross-sectional area G of the non-return mechanism is set so that the problem that the non-return mechanism operates after moving backward and air enters the pen tip (a so-called poor sensitivity state) does not occur. The dimensions were smaller than 50 times the area S. With such a range, it is possible to provide a mechanism in which particularly large particles are not clogged on the way and the sensitivity of the backflow does not cause any problem. In addition, centrifugal force of 3000G is applied when centrifugal defoaming during assembly is more than 10G, so the check ball will not move because the receiving protrusion in the joint is difficult, the receiving protrusion will be broken, and the receiving protrusion will swell with ink. Therefore, when the joint is made of synthetic resin, the resin material used as the base material has at least one of the three items of heat resistance, chemical resistance, and rigidity that are higher than those of the base component. These problems can be further eliminated by molding with a metal powder such as aluminum, copper, metal whiskers, or glass, carbon, talc, or other inorganic substances or organic substances such as engineering plastics that are dispersed or compatible with organic substances such as aluminum, copper, and metal whiskers that have excellent performance. Can be used as a writing instrument. In the case of base polypropylene only, the centrifugal deformation resistance test is 600
Deformation occurred at about G, and in the heat resistance test, it was deformed at 90 ° C. for 1 hour. However, a material in which glass fiber as an additive was dispersed at 10% by weight in polypropylene as a base material increased rigidity and improved heat resistance. The centrifugal force G during work is 20
Even at 00G, there is no deformation or destruction, and a heat resistance test (100 ° C, 2 hours) that is conscious of the interior of a car in midsummer
However, there was no problem at all, and the backflow prevention mechanism of the present invention was able to be advanced. As a combination having the same effect, a base material such as polyethylene, polyacetal, polyamide, polystyrene, or polyethylene terephthalate, and additives such as aluminum powder, glass beads, talc, mica, whisker, and carbon fiber can be considered. Further additives such as polyphenylene ether, unsaturated polyester resin, polypolyamide, polyimide, melamine resin which is a thermosetting resin,
Rigidity often increases only slightly with materials in which fluorine resin or the like is dispersed or compatible with the base material.However, chemical resistance and heat resistance can be increased, and the check mechanism swells over a long period of time. As a result, it is possible to provide a check mechanism that does not cause a problem that the ink flow path is narrowed or a problem that the seal surface for preventing backflow is not perfect because the ink flow path becomes brittle and cracks are broken.

As a second embodiment of the present invention, as shown in FIG. 4, a pen tip has an axially continuous irregular cross-section or a capillary tube such as a fiber bundle, and the outside has a non-permeable resin or metal. The writing point is a pen tip covered with a pen, which is a so-called sign pen or marker that has an ink storage tube behind the pen tip and stores ink directly inside the pen tip. The configuration of the check mechanism is the first embodiment. The effect is the same as that of the first embodiment described above by making it exactly the same as the example. The check mechanism may be a writing implement in which the valve chamber in the joint is decentered so that the check ball does not block the rear end of the pen tip even if the check ball moves forward.

As a third embodiment of the present invention, as shown in FIG. 5, a tip spring for pressing with a load of about 1 g to 40 g is built in, and a circumferential caulking portion serving as a sealing surface with a writing ball is provided. A ball valve mechanism is formed by the writing ball and the writing ball, thereby providing a non-return mechanism having a structure for improving impact resistance, preventing ink volatilization, and preventing reverse flow of ink. This tip spring is usually a spring with a linear portion integrally provided at the tip to directly press a very small writing ball of φ0.3 to φ1.2, and the tip of the tip is used to prevent the tip from coming off. Is secured by caulking. In this case, the minimum cross-sectional area G of the check mechanism is exactly the same as the projected cross-sectional area S of the ball of the writing portion, and the rear end side is a flow path having a larger cross-sectional area, and the effect of the present invention is exhibited. You. In addition, when a hot-melt type tip sealant 16 that melts at 80 ° C. to 150 ° C. is attached to the tip for the purpose of protecting the pen tip and preventing volatilization during transport, long-term storage is improved and transport to the user is performed. Trouble can be prevented.

As a fourth embodiment of the present invention, as shown in FIG. 6, instead of a check ball, a material having a specific gravity greater than that of ink and having a tapered portion for closing the sealing surface at the rear end side. In addition, a check top having a groove or a protrusion serving as an ink flow path in front of the pen tip side is provided. The minimum cross-sectional area G in the check mechanism is equal to or larger than the projected cross-sectional area S of the writing section. In addition, it is a writing instrument that is within 50 times.

In another embodiment (not shown), a joint is not used, a check ball is loosely fitted inside the pen tip, and the rear end of the pen tip is radially inwardly sealed over the entire circumference. The spring that comes out of the pen tip is formed by holding the check ball and preventing it from slipping out. The same effect of the present invention can be expected even with the writing implement of the embodiment, such as an object received inside the joint.

[0011]

The operation of the present invention will be described in an embodiment. Generally, it is thought that the backflow of the writing instrument can be prevented by having the backflow prevention mechanism, but when various inks are used in recent years, the resistance of the ink flow path is increased by the backflow prevention mechanism. There is a problem that rash occurs and the colorant particles are clogged. However, experiments have shown that if the minimum cross-sectional area of the check mechanism is too large, the operation of the check mechanism will be delayed, and the minimum cross-sectional area G of the check mechanism of the present invention is changed to the minimum cross-sectional area of the pen tip. It was found that when the value is equal to or more than S and within 50 times, the function of the check mechanism without these problems can be obtained. Further, by setting the viscosity of the ink, the particle size of the colorant, and the type and amount of the solvent within the scope of the present invention, the operation of the check mechanism is made effective, and the operation delay of the check mechanism is reduced by volatilization of the pen tip. In addition to this, it is possible to expect an effect of preventing blurring and backflow by interaction with the ink flow path. In addition, by using a material in which the second component having excellent heat resistance, chemical resistance, and rigidity is dispersed or dissolved in the base material as a material of the joint, there is a problem in the manufacture of the non-return mechanism and an ink in long-term storage. Effectively works to secure the flow path.

[0012]

The construction and operation of the writing instrument according to the present invention are as described above, and have the effect of not causing a serious accident such as backflow that stains clothes. It is possible to provide an easy-to-use writing instrument that can easily use the writing instrument. In addition, there is no problem in manufacturing, and it is possible to use a writing implement that is common to all inks that do not need to combine various parts depending on the ink type. It is possible to provide a stable product with good long-term durability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a distal end portion of a writing instrument according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a check mechanism section AA of the writing instrument according to the first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing the entire writing instrument according to the first embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a tip portion of a writing instrument according to a second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a tip portion of a writing instrument according to a third embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a tip portion of a writing instrument according to a fourth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pen tip 2 writing ball 3 joint 4 receiving protrusion 5 seal face of seal piece 6 seal piece 7 check ball 8 ink storage tube 9 air hole 10 ink 11 follower 12 follower rod 13 tail plug 14 pen tip caulking part 15 spring 16 straight part 17 Back end caulking 18 Reverse check 19 Reverse check taper

Claims (4)

[Claims] 1. A ball-point pen having an ink storage tube at the back of a pen tip to which a ball serving as a writing portion is rotatably retained and loosely fitted with the ball protruding from the tip, and which stores ink directly inside thereof. In the case where the pen tip is upward or in a non-writing state, the ink flow path is closed to prevent backflow, and the pen tip is in a downward or writing state ahead of the air replacement hole. In such a case, a so-called backflow prevention mechanism for securing an ink flow path for writing is provided. The minimum cross-sectional area G mm2 of the ink flow path in this backflow prevention mechanism is the projected cross-sectional area S mm2 of the writing ball. Between (S × 50)> G
A ballpoint pen-type writing implement, provided so as to satisfy the relational expression of> = S. 2. A writing portion having a pen tip having an irregularly continuous section in the axial direction or a capillary tube made of a fiber bundle or the like and having an outside coated with a non-permeable resin or metal as a writing portion, and an ink storage tube behind the pen tip. In the case of a so-called sign pen or marker that stores ink directly inside the pen, when the pen tip is turned upward or in a non-writing state, the ink flow path is closed to prevent backflow, and the pen tip is A so-called backflow prevention mechanism that secures an ink flow path for writing when facing down or in a writing state is provided. The minimum cross-sectional area G mm2 of the ink flow path in this backflow prevention mechanism is determined by the writing pen tip. And a projected cross-sectional area S mm2 of the ink flow path inside the writing tool, wherein the writing tool is provided so as to satisfy the relational expression of (S × 50)>G> = S. 3. An ink viscosity at a typical shear rate of 23
At 100 ° C., the average particle size in terms of spheres as a colorant is from 0.30 μm to 3.0.
μm of an ink in which at least one kind of metal powder such as aluminum or an inorganic substance such as mica is dispersed, the ink contains 50% or more of water as a main solvent, and water such as ethylene glycol, propylene glycol or glycerin. A solvent having a higher viscosity than that of water and a volatilization solvent which is harder to volatilize than water is used as an auxiliary solvent, and at least one or more of them are used in a total of 3% or more and 40% or more.
The writing implement according to claim 1, wherein the writing implement has an ink containing not more than%. 4. A backflow prevention mechanism, wherein a joint provided between the front end of the writing portion and the rear end of the ink containing tube is made of synthetic resin, and the material of the resin includes a base resin component and a base component. Metal powder such as aluminum, copper, metal whisker, or glass, carbon, which is superior in at least one of the three items of heat resistance, chemical resistance, and rigidity.
The writing implement according to any one of claims 1 to 3, wherein the writing implement is formed of a synthetic resin in which an inorganic substance such as talc or an organic substance such as engineering plastic is dispersed or dissolved.