JP6423240B2 - Writing instrument - Google Patents

Description

  The present invention relates to a writing instrument suitable for a marking pen or the like that causes ink in a writing refill to flow out by using pressure applied by writing pressure.

2. Description of the Related Art Conventionally, writing tools that cause ink in a writing refill to flow out according to writing pressure are known.
For example, 1) Assuming that high-viscosity ink is pumped using a pressurizing action by writing pressure and writing is possible, a return spring is urged between the shaft tube and the tip device, and the tip device is applied to the shaft tube. Is provided to move back and forth within an appropriate range, a first spring is inserted into the tip bore, a second valve body abuts on the rear end thereof, and a second spring is mounted on the rear end of the second valve body. The rear end of the second spring is inserted so that it cannot be removed from the rear end of the chip, the rear end of the tip ball is pressed, and the tip ball comes into close contact with the inner edge of the ball holding portion of the chip. A closed space filled with ink is formed between the tip ball of the chip and the valve body, and the ink from the tip of the tip is retracted by the retraction of the tip of the tip tube due to the writing pressure. When it is pushed out and the writing pressure is released, Jill and ballpoint cursive a negative pressure in the valve body opens the ink, characterized in that it is configured to be replenished (e.g., see Patent Document 1),
2) The ball of the nib is pushed in by a writing load, the valve function is opened, and a part of the ink transport unit is contracted, so that the ink in the ink transport unit flows into the hole in the writing chip and the writing is performed. When the writing load is released, a part of the ink transport part returns to the pre-contraction state and the internal pressure becomes negative, so that the ball valve in the valve chamber is released and guided from the ink containing tube. A writing instrument (for example, see Patent Document 2) that is configured to allow ink to flow through a hole and that can be written by supplying ink to the pen tip with a writing load when the pen tip is used downward is known. Yes.

  However, each of the writing tools described in Patent Documents 1 and 2 is a writing unit in which the ink in the writing refill flows out according to the writing pressure, but the pen tip is made of a spring tip having a sealing property. Therefore, it is necessary to take measures such as sealing the tip of writing, and when a pressurizing mechanism is formed in the ink flow path, there is a problem that a structure for smooth outflow of ink is required. In particular, in a writing instrument that causes the ink in the writing refill to flow out according to the writing pressure, even if a non-sealable pen tip is used for the writing part, such as shear thinning ink that becomes high viscosity without using a complicated mechanism There is a strong demand for writing instruments that allow ink to flow smoothly.

JP-A-11-240287 (Claims, drawings, etc.) JP 2013-193272 A (Claims, drawings, etc.)

  The present invention has been made in view of the above-described problems of the prior art, and is intended to solve this problem. Even when the pen tip uses a non-sealable pen tip, the pressure applied by the writing pressure is used in the writing refill. To provide a writing instrument suitable for a marking pen that can smoothly flow out ink from a writing portion and that maintains the pressure in the writing refill at normal pressure even when the writing pressure is released and does not blow out ink. With the goal.

  As a result of intensive studies to solve the above-described conventional problems, the present inventors have used a non-sealable nib in the writing portion of the writing refill that becomes an ink tank accommodated in the shaft cylinder, It is a writing instrument that pressurizes the ink tank when writing pressure is applied, and finds that the above-mentioned writing instrument can be obtained by providing a pressurizing mechanism having a specific structure on the rear end side of the writing refill, thereby completing the present invention. It came to.

That is, the present invention resides in the following (1) to (4).
(1) A writing instrument that uses a non-sealable pen tip in the writing part of the writing refill to be an ink tank housed in the shaft cylinder, and the ink tank pressurizes when writing pressure is applied, and the trailing end of the writing refill A writing instrument characterized in that a pressure mechanism is provided on the side and the entire writing refill is movable.
(2) The writing instrument as described in (1) above, wherein the pressurizing mechanism has a flexible member in order to compress and expand.
(3) The writing instrument as described in (1) or (2) above, wherein the pressurizing mechanism has a check valve for taking in air when the writing pressure is returned.
(4) The writing instrument as described in any one of (1) to (3) above, wherein the writing refill is filled with shear thinning ink.

  According to the present invention, even when the pen tip uses a non-sealable pen tip, the ink in the writing refill can be smoothly discharged from the writing portion by using the pressure applied by the writing pressure, and the writing pressure can be reduced. Thus, a writing instrument suitable for a marking pen or the like that maintains the pressure in the writing refill at normal pressure and does not blow out ink even if is released.

It is the writing instrument of the non-writing state which shows an example of embodiment of this invention, (a) is a front view, (b) is a longitudinal cross-sectional view, (c) is an expanded longitudinal cross-sectional view of a pressurization mechanism. FIGS. 1A and 1B show a state at the start of pressurization of the writing instrument of FIG. 1, where FIG. 1A is a front view, FIG. 1B is a longitudinal sectional view, and FIG. 1 shows a state in which the writing pressure of the writing instrument of FIG. 1 is maximized, (a) is a front view, (b) is a longitudinal sectional view, and (c) is an enlarged longitudinal sectional view of a pressurizing mechanism. FIG. 2 shows an example of a writing refill provided with a pen tip which is a component of the writing instrument in FIG. 1, (a) is a front view, and (b) is a longitudinal sectional view. FIG. 2 shows an example of a cylindrical member used for the pressure mechanism of the writing instrument in FIG. 1, (a) is a perspective view seen from the left side, (b) is a left side view, (c) is a plan view, and (d) front view. (E) is a longitudinal sectional view, (f) is a perspective view seen from the right side, and (g) is a right side view. FIG. 2 shows an example of a flexible member used in the pressure mechanism of the writing instrument in FIG. 1, (a) is a perspective view seen from the left side, (b) is a left side view, (c) is a plan view, (d ) Front view, (e) is a longitudinal sectional view, (f) is a perspective view seen from the right side, and (g) is a right side view. FIG. 2 shows an example of a tail plug used in the pressure mechanism of the writing instrument in FIG. 1, (a) is a perspective view seen from the left side, (b) is a left side view, (c) is a plan view, and (d) front view. (E) is a longitudinal sectional view, (f) is a perspective view seen from the right side, and (g) is a right side view.

Embodiments of the present invention will be described below in detail with reference to the drawings.
1-7 is each drawing of the writing instrument which shows an example of embodiment of this invention.
As shown in FIGS. 1 to 3, the writing instrument A of the present embodiment includes a writing refill 20 serving as an ink tank housed in a shaft cylinder 10 serving as a writing instrument body, and a pen provided at the front portion of the writing refill 20. The pen 30 and the cap 40 for sealing the nib 30 are provided. The writing refill 20 serving as an ink tank is filled with ink 25, and a trailing body 26 is filled at the rear end of the ink 25. A pressure mechanism 50 is provided on the rear end side of the writing refill 20 to pressurize ink when writing pressure is applied.

The shaft tube 10 serves as a writing instrument body (outer shaft), and can be formed using a synthetic resin, metal, or the like. In this embodiment, the shaft tube 10 uses acrylonitrile styrene (AS) resin. And is formed into a cylindrical shape.
The shaft cylinder 10 includes a writing refill 20 that accommodates the ink 25.
The writing refill 20 is preferably one that does not suffer from the adverse effects of the raw materials contained in the ink contained therein over time, for example, polypropylene (PP), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene (PE). It is possible to use a visible or non-visible material such as a resin such as aluminum or a metal such as aluminum. In this embodiment, the writing refill 20 serving as an ink tank is formed into a cylindrical shape using polypropylene (PP).

The ink 25 accommodated in the writing refill 20 serving as an ink tank is not particularly limited, such as water-based ink, oil-based ink, and gel ink. The ink composition to be used includes pigments (including resin pigments), coloring agents such as dyes, main solvents, resins, and additives depending on the application (water-based ink, oil-based ink, gel ink, etc.) and writing instrument type (marking pen, ballpoint pen, etc.). Arbitrary components contained in the ink for a sticky agent and a writing instrument can be used.
As optional components, for example, rust preventives, antifungal agents, surfactants, lubricants, wetting agents and the like that can be compatible without adversely affecting the ink can be contained. In ballpoint pen inks, fatty acids and the like can be suitably used as lubricants. Further, as a drying inhibiting additive, a non-volatile solvent that is compatible with the main solvent may be contained within a range that does not adversely affect the product characteristics.
In this embodiment, the ink 25 is 20 to 3000 mPa · s at a shear rate of 3.83 / s and a viscosity value of 5 to 200 mPa at a shear rate of 383 / s as measured with an EMD type viscometer at 25 ° C. -It is comprised with the ink for water-based sign pens which has the shear thinning viscosity used as s.

A follower (following body) 26 that follows the ink consumption during writing is provided at the rear of the ink 25 filled in the writing refill 20, and the rear side thereof is a space portion 27 that serves as an air chamber.
The follower (follower) 26 is preferably one that has low permeability and low diffusibility with respect to the solvent used in the ink. The base thereof is a non-volatile or hardly volatile fluid, specifically, polybutene. Or liquid paraffin, mineral oil, process oil, etc. can be used.
When the viscosity of these substances is low, it is preferable to use a thickener or a gelling agent. Specific examples include metal soaps, bentonites, fatty acid amides, hydrogenated castor oil, metal fine particles containing titanium oxide, silica, alumina and the like, celluloses, elastomers, and the like. In the present embodiment, the follower (follower) 26 is composed of mineral oil and a thickener.

The pen tip 30 includes a pen core 31 that is a writing unit made of a porous body, and a relay core 32 that relays the ink 25 in the writing refill 20 to the pen core 31.
The pen core 31 serving as a writing unit is, for example, a fiber bundle composed of natural fibers, animal hair fibers, resin fibers, etc., a fiber bundle such as felt, or a fiber core obtained by resin processing of these fiber bundles, or It consists of a sintered core (porous body) obtained by sintering various plastic powders. Examples of the shape include a chisel shape, a cannonball shape, a cylinder, an elliptical column, a cube, a rectangular parallelepiped shape, and a cross-sectional shape of which is a trapezoid, a parallelogram, a rhombus, a kamaboko, and a half moon In this embodiment, it is composed of a chisel-shaped sintered core. The chisel shape is a shape in which the tip forms an inclined surface with respect to the center line of the pen shaft, and the inclined surface is flat.

  As shown in FIGS. 4A and 4B, the pen core 31 is fixed by a cylindrical joint member 35 attached to the outer peripheral surface portion 20 a on the distal end side of the writing refill 20. The joint member 35 includes a cylindrical fixing portion 35a that is fixed to the distal end side outer peripheral surface mouth portion 20a of the refill 20 by fitting, and a holding portion 35b that holds the pen core 31, and in the holding portion 35b. The relay core 32 made of a porous material is stored and held, and the ink 25 filled in the writing refill 20 that becomes an ink tank is supplied to the pen core 31 that becomes the writing portion through the relay core 32 made of the porous material. It has become.

The writing refill 20 in which the pen core 31 is fixed to the tip by the joint member 35 is further attached to the front end side of the shaft tube 10 by a base 36 and accommodated so as to be slidable backward in the shaft tube 10. It has become. The joint member 35 attached to the writing instrument refill 20 is held by a cylindrical base 36 attached to the tip outer peripheral portion 11 of the shaft tube 10 by fitting.
As shown in FIGS. 2A and 2B, the base 36 holds an attachment portion 36 a attached to the tip outer peripheral portion 10 a of the shaft tube 10 by fitting, and a rear end side outer periphery of the joint member 35. A holding portion 36b, and between the front end portion of the shaft tube 10 and the rear end portion of the joint member 35, the writing refill 20 is moved backward in the shaft tube 10 with the writing pressure of the pen core 31, as will be described later. It is attached to the outer periphery of the tip outer peripheral portion 10a of the shaft tube 10 and the fixing portion 35a on the rear end side of the joint member 35 so that a movable space portion 37 is formed so that the joint member 35 can move backward when moving. Yes.

As shown in FIGS. 1A and 1B, the cap 40 includes a cylindrical main body portion 41 serving as a mounting portion that is detachably attached to the front end side of the shaft tube 10, and an opening portion of the main body portion 31. The crown 42 attached to the head, and a rubber such as nitrile rubber (NBR) and butyl rubber (IIR) that seals the entire protruding portion of the pen tip 20 inside the crown 42, a thermoplastic elastomer, a soft resin, etc. And a plate-like mounting portion 44 for mounting the sealing member 43.
By fitting the cap body 40 to the front end side of the shaft tube 10, the entire tip of the pen core 31 protruding from the joint member 35 is sealed by the seal member 43. The seal member 43 of this embodiment is made of butyl rubber (IIR).

In this writing instrument A, as shown in each of FIGS. 1 to 3, when writing pressure is applied to the rear end side of the writing refill 20, the entire writing refill 20 moves rearward and pressurizes the ink. A mechanism 50 is provided.
The pressurizing mechanism 50 includes at least a cylindrical member 60 fixed to the rear end portion of the writing refill 20, a flexible member 70 having a check valve, and a tail fixed to the rear end opening portion of the shaft tube 10. A stopper 80 is provided. As will be described later, the pressurizing mechanism 50 is provided with a flexible member 70 having a check valve that can be shrunk by a writing load on the rear end portion side of the writing refill 20, whereby writing pressure is applied. The entire writing refill 20 slides rearward, the rear end side of the writing refill 20 is sealed, and the volume shrinks, so the inside of the writing refill 20 is pressurized, the ink is pushed out to the pen core 31 side, and the writing pressure is released. Then, the inside of the writing refill 20 expands in volume, but since the rear end portion is a valve body 75 serving as a check valve, air is immediately flowed into the writing refill 20 from outside air without reducing pressure. It will return to its original state.

The cylindrical member 60 constituting the pressurizing mechanism is fixed to the rear end opening 20a of the writing refill 20, and the outer diameter of the cylindrical member 60 is substantially the same as that of the writing refill 20 as shown in FIGS. A large-diameter portion 61 having the same diameter, and a medium-diameter portion 63 that is continuous with the large-diameter portion 61 and has a medium diameter. Ventilation holes 62 and 62 are formed on the top and bottom surfaces of the large-diameter portion 61. In addition, the intermediate diameter portion 63 has a fitting protrusion surface 63a on the outer peripheral surface on the base end side and a fitting step portion 63b on the inner peripheral surface.
In the cylindrical member 60, the middle diameter portion 63 is fixedly fitted into the rear end opening 20 a of the writing refill 20 by fitting, and the rear end opening 20 a of the writing refill 20 is sealed by the end surface 61 a of the large diameter portion 61. It will be a thing.

The flexible member 70 constituting the pressurizing mechanism is fixed to the inside of the cylindrical member 60. As shown in FIGS. 6A to 6G, a cylindrical member having a flange 71 on the proximal end side. A main body 72, a cylindrical expansion / contraction part 73 sequentially from the main body 72 toward the distal end side, a thick connection part 74 having an inner diameter that becomes a small diameter, and a fitting protrusion 74 a on the outer peripheral surface, and the connection part 74. And a valve body 76 serving as a duckbill-shaped check valve in which a slit 75 is formed toward the distal end side.
The flexible member 70 is made of a flexible material, and can be integrally formed with, for example, a synthetic rubber, a thermoplastic elastomer, a soft resin, or the like.

  The flexible member 70 is fixed in a cylindrical member 60 attached to the rear end opening of the writing refill 20. Specifically, when the flexible member 70 is press-fitted into the cylindrical member 60, the fitting protrusion 74a of the thick connecting portion 74 enters to the vicinity of the fitting step portion 63b in the cylindrical member 60, and has a duckbill-like shape. The distal end side of the valve body 76 serving as a check valve is configured to protrude into the space portion 27 of the writing refill 20. The cylindrical main body 72 having the flange 71 of the flexible member 70 is fixed by fitting into the large diameter portion 61 of the cylindrical member 60, and the opening 60 a of the cylindrical member 60 is sealed by the flange 71. It will be a thing.

The tail plug 80 constituting the pressurizing mechanism includes a cylindrical tail plug body 82 having a flange 81 fixed by fitting in the opening 10b on the rear end side of the writing instrument body 10, and the cylindrical tail plug. A closing portion 83 for closing the front end surface of the main body portion 82 and a rod-like portion 85 having a vent hole 84 on the inside from the central portion of the closing portion 83 to the distal end side. The closing portion 83 includes a rod-like portion 85. Ventilation holes 83a and 83a larger than the ventilation hole 84 of the rod-like portion 85 are formed in the proximity.
When this tail plug 80 is fitted into the opening 10b on the rear end side of the writing instrument body 10 by fitting,
The rod-shaped portion 85 having the vent hole 84 passes through the cylindrical main body 72 of the flexible member 70 and is press-fitted into the small-diameter stretchable portion 73, and the tip of the rod-shaped portion 85 is the stepped portion 75 b of the connecting portion 74. It becomes the structure which contacts. Thereby, the flow of air into the writing instrument refill 20 is performed only from the tail plug 80 side.
Further, the tail plug main body 82 and the main body 72 of the flexible member 70 form a movable space 90 of the writing instrument refill 20 without abutting. The length t of the movable space 90 is the movable (sliding) range of the writing instrument refill 20.

In the writing instrument A of the present embodiment configured as described above, the ink in the writing refill can be smoothly discharged from the writing portion by using the pressure applied by the writing pressure, and the writing refill can be achieved even if the writing pressure is released. The internal pressure is maintained at normal pressure.
The action mechanism of the writing instrument A will be described in detail with reference to FIGS. FIG. 1 is a non-writing state, FIG. 2 is a state at the start of pressurization of the writing instrument A, and FIG. 3 is a drawing showing a state where the writing pressure of the writing instrument is maximized.
When writing pressure is applied to the pen core 31 serving as the writing unit, the entire writing instrument refill 20 is moved backward (to the tail plug 80 side) as shown in FIGS. Immediately after the movement, the fitting protrusion 74a of the connecting portion 74 of the flexible member 70 comes into contact with the fitting step portion 63b in the cylindrical member 60 and seals.
Furthermore, when writing pressure is applied, the expansion / contraction part 73 of the flexible member 70 extends, and the fitting protrusion 74a slides toward the pen core 31 side while being sealed by the fitting step part 63b in the cylindrical member 60. By compressing the inside of the writing instrument refill 20 serving as an ink tank, the ink in the writing instrument refill 20 is pressurized, and the ink is pushed out (flows out) to the pen core 31. When the writing pressure is maximum, the flange 71 of the flexible member 70 contacts the closing portion 83 of the tail plug 80 as shown in FIG.
When writing is stopped, the return force (elastic force) of the expansion / contraction part 73 of the flexible member 70 advances the writing instrument refill 20 to expand the inside of the writing instrument refill 20 serving as an ink tank. Since the valve body 76 is a check valve, the outside air is taken into the writing tool refill 20 from the tail plug 80 side through the vent hole 84 of the rod-like portion 85 and the valve body 76 (the slit 75 opens). The inside of the refill 20 becomes a normal pressure and returns to the original state (non-writing state).

In the writing instrument A of the present embodiment, the ink in the writing refill is applied using the pressure applied by the writing pressure even if a non-sealable pen tip is used without using a spring tip having a sealing tip. The writing part can be smoothly discharged from the writing part, and even if the writing pressure is released, the pressure in the writing refill is maintained at a normal pressure, and the writing tool is suitable for a marking pen or the like that does not blow ink.
Furthermore, in the writing instrument A of the present embodiment, when the cap 40 is mounted, the entire protruding portion of the pen core 31 is sealed by the seal member 44. Therefore, even when the internal pressure changes such as heating of the ink tank, the pen tip The direct current phenomenon from 30 is prevented.

  The present invention is not limited to the above-described embodiment, and can be modified into various forms without departing from the gist of the present invention.

  Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[Example 1: based on FIGS. 1 to 7]
(Each component such as shaft tube, writing refill, and nib)
Shaft tube (writing instrument body) 10: made of AS resin, wall thickness (average thickness other than the gripping part) 1.5 mm, length 120 mm, diameter φ10 mm
Written refill (ink tank) 20: made of PP, thickness (thickness) 0.8 mm, length 100 mm, diameter φ5.6 mm
Base: Made of SUS (configuration of the nib)
Joint member: PBT, 12.5mm long
Relay core: Acrylic fiber core, length 5mm, diameter φ5mm
Writing part pen core: PET fiber core, porosity 60%, length 10 mm, chisel shape (cap configuration)
Body: Made of PP, Seal member: Made of IIR (Configuration of pressure mechanism)
Cylindrical member: made of polypropylene, length 12 mm, vent hole φ3 mm
Flexible member: NBR, length 15 mm, slit length 3 mm
Tail plug: made of polypropylene, length 20 mm, rod-like portion length 10 mm, rod-like portion vent hole φ0.6 mm,
Movable length t: 2mm

(Composition of ink 25 and follower 26)
As the ink, a shear thinning ink having the following composition (25 ° C., EMD type viscometer: VISCOMETER RE110R: manufactured by Toki Sangyo Co., Ltd., 791 mPa · s at a shear rate of 3.83 / s, 37 mPa · s at a shear rate of 383 / s, 100 parts by weight in total) was used.
Colorant: WATER BLACK R455 (manufactured by Orient Chemical Industry Co., Ltd.) 10 parts by mass Bubble inhibitor: 1 part by mass of citrulline Oxygen absorbent: 0.5 part by mass of water-soluble liquid medium: 5 parts by mass of glycerin Water-soluble liquid medium: propylene glycol 10 parts by mass pH adjuster: triethanolamine 1.6 parts by mass Lubricant: Potassium soap potassium ricinoleate 0.3 parts by mass Preservative: Natriumumomadin 0.1 parts by mass Rust preventive: benzotriazole 0.2 parts by mass Part Thickener: Xanthan gum 0.3 part by mass Water (main solvent): ion-exchanged water Remainder As a follower, Matsumura Oil Co., Ltd. Barrel Process Oil P-26 was used.

  When the writing instrument of Example 1 configured in this way is actually used, when writing pressure is applied to the pen core 31, the entire writing refill 20 slides backward, and the ink 25 flows out from the pen core 31 appropriately. Even if the writing pressure is released, since the outside air flows into the writing refill 20 by the check valve 76 of the pressurizing mechanism, the pressure in the writing refill 20 can be controlled to normal pressure, and the ink DC It was confirmed that there was no phenomenon.

  In the writing instrument of this invention, it can be used conveniently for marking pens, such as an underline pen, an oil-based marker, and a water-based marker.

A Writing instrument 10 Shaft cylinder 20 Writing refill (ink tank)
25 ink 26 follower (follower)
30 Pen Tip 31 Pen Core 32 Relay Core 40 Cap 50 Pressure Mechanism 60 Cylindrical Member 70 Flexible Member 75 Slit 76 Valve Element (Check Valve)
80 Tail plug

Claims (4)

A writing instrument that uses a non-sealable pen tip in the writing part of the writing refill, which is the ink tank housed in the shaft cylinder, and pressurizes the ink tank when writing pressure is applied, compressing to the rear end side of the writing refill A writing instrument comprising a pressurizing mechanism in which a flexible member and a check valve for taking in air when the writing pressure is returned to expand are provided, and the entire writing refill is movable. The writing instrument according to claim 1 , further comprising a cap that seals the writing portion, the cap having a plate-like mounting portion on which a seal member that seals a protruding portion of the writing portion is mounted . The pressurizing mechanism is fixed by fitting into at least a cylindrical member fixed to the rear end opening of the writing refill, a flexible member fixed to the cylindrical member, and an opening on the rear end side of the writing instrument body. And a rod-shaped portion having a vent hole in the inside from the center portion of the tail plug to the distal end side, and the rod-shaped portion having the vent hole is press-fitted into the expansion / contraction portion of the flexible member. The writing instrument according to claim 1 or 2. A shear-thinning ink having a viscosity of 20 to 3000 mPa · s at a shear rate of 3.83 / s and a viscosity value of 5 to 200 mPa · s at a shear rate of 383 / s when measured with an EMD type viscometer at 25 ° C. The writing instrument according to claim 1, wherein the writing refill is filled.

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