Ballpoint pen
The writing instrument addresses ink leakage by using an air displacement groove and a compressible joint to manage pressure, ensuring ink is supplied smoothly and allowing for controlled line width and shading expression.
Patent Information
- Application Number
- JP2021016857
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-02-04
- Publication Date
- 2025-01-06
- Estimated Expiration
- 2041-02-04
AI Technical Summary
Existing writing instruments face the issue of ink leakage due to residual pressure in the writing section after use, and there is a need to eliminate this pressure to prevent ink from leaking.
A writing instrument design featuring a linear groove on the outer periphery of an air displacement member between the writing section and the ink accommodating section, with a compressible joint that contacts the writing surface before the joint compresses, and a cap that connects to the barrel, ensuring ink is supplied via the writing pressure applied to the tip.
The design effectively eliminates pressure within the writing section, preventing ink leakage and allowing for controlled line width and shading expression through varying writing pressure, mimicking the feel of a fountain pen.
Smart Images
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Abstract
Description
[Technical field]
[0001] The present invention relates to a writing instrument. [Background technology]
[0002] 2. Description of the Related Art There have been proposals to make it possible to adjust the amount of ink flow to a pen tip in a writing instrument.
[0003] For this type of writing instrument, an ink flow rate adjustment mechanism has been proposed which has an elastic wall portion on the peripheral wall of the barrel, and when the elastic wall portion is pressed, opens and closes a valve member inside the barrel to adjust the ink flow rate (see, for example, Patent Document 1).
[0004] Also, in a writing instrument, a pump function has been proposed in which the internal volume of a part of the ink transport passage connecting the pen tip and the valve chamber is elastically contracted by the writing load, thereby enabling ink to be ejected from the writing tip (see, for example, Patent Document 2). [Prior art documents] [Patent documents]
[0005] [Patent Document 1] JP 2002-283786 A [Patent Document 2] JP 2013-193272 A Summary of the Invention [Problem to be solved by the invention]
[0006] However, in the above-mentioned writing implement, if a pressurized state remains within the writing part after writing, there is a possibility that ink may leak from the writing part.
[0007] In view of the above circumstances, the present invention aims to provide a writing implement capable of releasing the pressurized state in the writing part and preventing ink from leaking out from the writing part. [Means for solving the problem]
[0008] The present invention is a writing instrument in which ink contained in an ink storage compartment at the rear of the barrel is supplied by the writing part sliding back and forth due to writing pressure applied to its tip, and which is characterized in that a linear groove along the axis is formed on the outer periphery of an air replacement member contained between the ink storage compartment and the writing part.
[0009] In the present invention, it is preferable that the outer periphery of the tip of the writing part is provided with a ferrule that connects to the barrel, and a joint that can be compressed as the writing part moves is attached between the air replacement member and the writing part, and when writing with the writing part in a vertical position, the ferrule abuts against the writing surface before the compression part of the joint abuts.
[0010] In the present invention, it is preferable that the ink contains an aqueous ink composition for a writing instrument, which contains at least a dispersion of colored resin microparticles for aqueous ink, characterized in that the colored resin microparticles are dispersed in water and are composed of a cyclohexyl (meth)acrylate monomer and a basic dye or an oil-soluble dye, wherein the content of the cyclohexyl (meth)acrylate monomer is 30 mass% or more based on all polymer components constituting the colored resin microparticles and the content of the basic dye or oil-soluble dye is 15 mass% or more based on all polymer components. Effect of the Invention
[0011] According to the writing instrument of the present invention, it is possible to obtain the excellent effect of providing a writing instrument capable of preventing the ink from leaking out from the writing part by releasing the pressurized state in the writing part, and also to easily express the shading of the written lines. [Brief description of the drawings]
[0012] [Figure 1] 1A and 1B are explanatory diagrams of a ballpoint pen according to an embodiment with the cap removed, in which (a) is a front view and (b) is an overall vertical cross-sectional view. [Diagram 2]2 is an explanatory diagram of the ballpoint pen of FIG. 1 when no writing pressure is applied, (a) being a front view, (b) being an overall longitudinal cross-sectional view, and (c) being a longitudinal cross-sectional view of the main parts from the collector to the writing part. [Diagram 3] 2A is a front view of the ballpoint pen of FIG. 1 when writing pressure is applied, FIG. 2B is a longitudinal cross-sectional view of the entire pen, and FIG. 2C is a longitudinal cross-sectional view of the main parts from the collector to the writing part. [Figure 4] FIG. 1 is a part diagram of a collector, in which (a) is an oblique view from the front, (b) is a view from the front, (c) is a front view from the side where the slits are formed, (d) is a view rotated 90 degrees circumferentially from (c) with the air replacement groove facing downward, (e) is a cross-sectional view along line EE of (c), (f) is a view rotated 90 degrees circumferentially from (d) as seen from the air replacement groove side, and (g) is an oblique view from the rear. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
[0014] In the embodiment, a ballpoint pen 1 having an internal collector is used as an example of a writing instrument. In the embodiment, the term "front" of the writing instrument and its components refers to the tip side of the writing instrument, and the term "rear" refers to the rear end side.
[0015] [Overall structure of ballpoint pen 1] As shown in FIG. 1, ballpoint pen (writing instrument) 1 includes a ballpoint pen tip (writing part) 40 that holds a writing ball 50 at its tip, an ink supply part 30 that supplies ink to the ballpoint pen tip 40, a joint 60 that connects the ballpoint pen tip 40 and the ink supply part 30, a barrel 10 that houses the ballpoint pen tip 40, the joint 60 and the ink supply part 30 inside, and an outer casing 20 that is attached to the tip of the barrel 10 and covers the outer periphery of the ballpoint pen tip 40.
[0016] In ballpoint pen 1, ballpoint pen tip 40 slides back and forth due to writing pressure applied to the tip of the ballpoint pen, thereby supplying ink contained in ink tank (ink storage section) 13 covered by the rear barrel at the rear of barrel 10. Collector (air displacement member) 31 housed between ink tank 13 and ballpoint pen tip 40 has an air displacement groove 31c formed on its outer periphery which is straight at the rear and slightly curved at the front.
[0017] [Shaft tube 10] As shown in Figures 1 to 3, barrel 10 has a cylindrical ink tank 13 with a closed rear end, a cylindrical front barrel 11 with a tapered front end and into whose inner periphery the front end of ink tank 13 fits, and a rear barrel 12 with a cylindrical rear end with a closed rear end and into whose inner periphery the rear end of front barrel 11 fits.
[0018] The outer diameter of ink tank 13 is approximately the same as the inner diameter of the rear end of front barrel 11. A protrusion that protrudes outward is provided on the outer periphery of ink tank 13 at a position approximately 1 / 3 of the way from the tip of ink tank 13, and this protrusion engages with the inside of front barrel 11 to fix ink tank 13 in place. Ink tank 13 is filled with ink (not shown).
[0019] Front barrel 11 is generally cylindrical with a tapered tip. A flange 15 is provided on the outer periphery of front barrel 11, the outer diameter of which is generally the same as the outer diameter of rear barrel 12, against which the tip of rear barrel 12 abuts.
[0020] As shown in each of Figures 1 to 3(b), front barrel 11 is made up of front barrel rear portion 14 which is roughly cylindrical at the rear, and front barrel front portion 16 which is tapered at the front, with flange 15 as the boundary. When ink tank 13 is fitted into front barrel rear portion 14, the uneven portion on the inner periphery of front barrel rear portion 14 engages with the uneven portion on the outer periphery of ink tank 13, so that ink tank 13 is detachably fixed to front barrel 11. Also, the outer periphery of front barrel rear portion 14 is formed with an uneven portion which engages with the uneven portion inside rear barrel 12, and the uneven portions engage with each other to detachably fix rear barrel 12 to the front barrel.
[0021] 2 and 3(b), a ring-shaped front barrel front inward protrusion 16a that engages with ink supply portion 30 is formed on the inner circumference of front barrel front portion 16 at a position where it begins to taper. Also, in front of front barrel front portion 16, there is provided outer barrel insertion hole 16b that is reduced in diameter so that the tip of joint 60 can be inserted, and into which outer barrel 20 connected to the front is inserted.
[0022] [Ink supply unit 30] 2 and 3, the ink supply unit 30 has a collector (temporary ink reservoir) 31 that is substantially cylindrical and has a plurality of blades 31a formed on the outer periphery in a comb-like shape, and a collector core 32 made of rod-shaped polyester fiber that passes through the collector 31 in the axial direction and has a tip portion 32a that fits into the rear end of the ballpoint pen tip 40. As shown in Fig. 4, a tip holder 34 with an expanded inner diameter is formed at the tip of the collector 31.
[0023] [Collector 31] As shown in Fig. 4, in collector 31, a ring-shaped collector flange 34a whose outer diameter tapers stepwise toward the tip side is formed on the outer periphery of tip holding portion 34. This collector flange 34a engages with front barrel front inward protrusion 16a formed on the inner periphery of front barrel front portion 16, and is prevented from slipping out of front barrel front portion 16, as shown in Figs. 2 and 3.
[0024] 4, the collector 31 has the function of temporarily storing overflowing ink from the ink tank 13 between the multiple vane portions 31a. Slits 31b are formed through the multiple vane portions 31a arranged in the axial direction, and the slits 31b have the function of guiding the temporarily stored ink to the collector core 32 side by capillary force.
[0025] In addition, a wide air replacement groove 31c is formed on the opposite side of the axis of the slit 31b. The air replacement groove 31 ensures smooth air circulation through the air replacement groove 31c when pressure fluctuations occur inside the ink tank 13, thereby properly replacing air from inside the ink tank 13 and preventing excessive supply of ink to the tip of the ballpoint pen tip 40 via the cocklet core 32.
[0026] The rear end of collector 31 is located in the space within front barrel front portion 16 and communicates with ink tank 13 through that space.
[0027] The rear end of the collector core 32 protrudes into the ink tank 13 , and the front end passes through the joint 60 from the rear end of the joint 60 and is inserted into the ballpoint pen tip 40 .
[0028] [Ballpoint Pen Tip 40] As shown in Figs. 2 and 3, the ballpoint pen tip 40 has a roughly cylindrical holder 42 and a writing ball 50 held by the holder 42. The rod-shaped tip 32a of the collector core 32 is inserted into the holder 42 from the rear end opening. At the tip of the holder 42, a crimped portion 42a is formed by pressing the small end inward to reduce its diameter. The tip of the writing ball 50 is exposed from the tip edge of the crimped portion 42a. The tip 32a of the collector core 32 reaches just behind the writing ball 50, and absorbs the ink that has permeated the collector core 32 and supplies the ink to the writing ball 50. Furthermore, about 1 / 3 of the ballpoint pen tip 40 from the tip is held by the outer 20.
[0029] The collector core 32 is formed by selecting an appropriate polyester fiber porosity and surface shape according to the properties of the ink used, such as the viscosity.
[0030] [Joint 60] As shown in Figures 2 and 3, the joint 60 is composed of a substantially cylindrical central member 61, a substantially cylindrical peripheral member 62 formed from about 1 / 4 to about 1 / 3 of the rear end of the central member 61 so as to have a gap 64 on the outer periphery of the rear of the central member 61, the gap being the thickness of the tip holding portion 34 of the collector 31, and an intervening member 63 formed to cover from the tip of the peripheral member 62 to a position about 1 / 3 of the way from the tip of the central member 61. The collector core 32 is inserted from the rear into the insertion hole 61a inside the central member 61 and protrudes forward, and the tip portion 32a is inserted into the ballpoint pen tip 40. The tip holding portion 34 is fitted into the gap 64 formed between the central member 61 and the peripheral member 62.
[0031] 2 and 3, an insertion hole 61a having approximately the same diameter as the collector wick 32 is provided at the rear end of the inner periphery of the central member 61. A ring-shaped central member flange 61b is formed on the outer periphery of the central member 61, located approximately 1 / 3 rearward from the tip of the insertion hole 61a of the central member 61 and forward of the tip of the peripheral member 62, and has a diameter smaller than the outer diameter of the tip holding portion 34.
[0032] Here, the outer diameter of the rear part 61c of the rear columnar part behind the central member flange part 61b is approximately the same as the inner diameter of the tip holding part .
[0033] The inner diameter of the peripheral member 62 is approximately the same as the outer diameter of the tip holding portion 34 of the collector 31. The inner periphery of the peripheral member 62 has a slightly enlarged diameter at its rear end. Here, the diameter of the enlarged rear end of the peripheral member 62 is smaller than the diameter of the collector abutment portion 34c, and is provided to make it easier to insert the tip holding portion 34.
[0034] 2 and 3, the intervening member 63 covers the peripheral member 62 up to its tip and engages with the front part of the peripheral member. The inner circumference of the intervening member 63 is formed to follow the outer circumference of the central member 61 and the peripheral member 62, and forms a connecting part (cushion part) 63a that has a smaller diameter rearward to the central flange part 61b. The inner diameter at the rear end of the connecting part 63a is the same as the inner diameter of the peripheral member 62, and the inner diameter at the front of the connecting part 63a is shaped to extend from the inner diameter of the intervening member 63 to the outer diameter of the central member flange part 61b, and to contact the outer circumference of the central member 61 at its front.
[0035] [Two-color molding] The joint 60 is a part molded by two-color molding, in which a central member 61 and peripheral members 62 are molded in a primary molding, and an intermediate member 63 is molded integrally with the central member 61 and peripheral members 62 in a secondary molding. The intermediate member 63 is formed from an elastic resin material at the connecting portion 63a to provide flexibility. As the elastic material, a thermoplastic elastomer is preferable because the molding process is performed at high temperatures using a mold. The material of the central member 61 and peripheral members 62, which are the primary molded bodies, is preferably a hard resin such as polyacetal resin.
[0036] [Outerwear 20] As shown in FIG. 2 and FIG. 3, the outer 20 is composed of a cylindrical outer fixing part 21 and an outer tapered part 22 having a substantially conical shape connected to the outer fixing part 21. The tip of the outer tapered part 22 is provided with a chamfered outer tip part 23. The outer 20 also has holes 24a and 24b formed inside from the rear end to the tip, and the inner surface of the outer fixing part 21 is provided with a rear insertion hole 24a, and the inner surface near the tip of the outer tapered part 22 is provided with a front insertion hole 24b having a smaller diameter than the rear insertion hole 24a. The outer fixing part 21 is fixed to the front barrel 11 by being attached to the outer insertion hole 16b of the front barrel front part 14. The outer 20 covers the ballpoint pen tip 40. At this time, the tip part 32a of the collector core 32 is inserted into the ballpoint pen tip 40, and the ballpoint pen tip 40 is inserted into the front insertion hole 24b so as to be movable forward and backward. As shown in FIGS. 2 and 3, writing ball 50 and crimped portion 42a covering writing ball 50 are exposed from outer tip portion 23.
[0037] [Function of the writing part (ballpoint pen tip 40)] The outer periphery of the tip of the writing part (ballpoint pen tip 40) is provided with a ferrule (outer 20) that connects to the barrel 10, and a joint (joint 60 having a central member 61, peripheral member 62, and intervening member 63) that can be compressed as the writing part (ballpoint pen tip 40) moves is attached between the air replacement member (collector 31) and the writing part (ballpoint pen tip 40). Therefore, when writing with the ballpoint pen tip 40 in a vertical position, the ferrule outer 30 comes into contact with the writing surface before the compressed part (intervening member 63) of the joint 60 comes into contact.
[0038] [Ink Production Examples 1-2: Dispersibility of Colored Ink Particles] Each color fine particle contained in the ink used in the ballpoint pen 1 was produced in the following production example. In the following, "parts" refers to parts by mass. The total amount (total weight) of each component in the production example is 500 parts.
[0039] [Production Example 1] A 2-L flask was equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen gas inlet tube, and a 1,000-mL separating funnel for monomer introduction, and placed in a warm water bath. 329.5 parts of distilled water, 5 parts of glycerin monomethacrylate (Blenmer GLM, NOF Corporation), 5 parts of sodium 2-sulfoethyl methacrylate (acrylic ester SEM-Na, Mitsubishi Chemical Corporation), 20 parts of a polymerizable surfactant (ADEKA Corporation, Adeka Reasoap SE-10N, ether sulfate), and 0.5 parts of ammonium persulfate were then charged, and the internal temperature was raised to 50° C. while introducing nitrogen gas.
[0040] On the other hand, a liquid was prepared by mixing a monomer mixture consisting of 55 parts of cyclohexyl methacrylate monomer and 35 parts of n-butyl methacrylate as another monomer with 40 parts of an oil-soluble dye (Suninyl Blue GLS, Clariant) and 10 parts of a crosslinking agent (triallyl isocyanurate, Nippon Kasei Chemical Industry Co., Ltd., "TAIC").
[0041] This preparation liquid was added from the separating funnel to the flask kept at about 50° C. over a period of 3 hours with stirring to carry out emulsion polymerization. The mixture was further aged for 5 hours to terminate the polymerization, yielding a dispersion of colored resin particles for aqueous ink (particles 1).
[0042] The content of the cyclohexyl methacrylate monomer was 50.0% by mass relative to the total polymer components constituting the colored resin particles, and the content of the oil-soluble dye was 36.4% by mass relative to the total polymer components. The average particle size of the colored resin particles was 40 nm.
[0043] [Production Example 2] A colored fine particle aqueous dispersion for aqueous ink (particles 2) was obtained in the same manner as in Production Example 1, except that in Production Example 1, 340.5 parts of distilled water, 30 parts of cyclohexyl methacrylate monomer, 45 parts of n-butyl methacrylate, and 20 parts of an oil-soluble dye (Valifast Pink 2310N, manufactured by Orient Chemical Industry Co., Ltd.), 12 parts of an oil-soluble dye (Oil Pink 314, manufactured by Orient Chemical Industry Co., Ltd.), and 12 parts of an oil-soluble dye (Valifast Red 3312, manufactured by Orient Chemical Industry Co., Ltd.) were used.
[0044] The content of the cyclohexyl methacrylate monomer was 31.6% by mass relative to the total polymer components constituting the colored resin particles, and the content of the oil-soluble dye was 46.3% by mass relative to the total polymer components. The average particle size of the colored resin particles was 82 nm.
[0045] The dispersions of colored resin microparticles for water-based inks obtained in Production Examples 1 and 2 each had a resin solid content of 20 to 40% by mass.
[0046] [Preparation of aqueous ink composition for writing instruments] Using the dispersions of the colored resin particles (particles 1 and 2) produced in Production Examples 1 and 2 above, aqueous ink compositions for writing instruments were prepared by a conventional method according to the formulations shown below (total amount 100% by mass).
[0047] Ink composition: (total 100% by mass) Dispersion of colored resin particles for water-based inks 20% by weight pH adjuster (triethanolamine) 1% by mass Water-soluble organic solvent (ethylene glycol) 5% by mass Ion-exchanged water 74% by mass
[0048] [Functions and Effects of Ballpoint Pen 1 of the Embodiment] In this ballpoint pen 1, the joint 60 is composed of three components, and although the peripheral component 62 and the central component 61 are the same primary molded body, they are not continuous with each other as primary molded bodies. As a result, the vicinity of the connecting portion 63a of the intervening component 63 deforms, making the joint 60 prone to bending.
[0049] When not writing and the writing pressure is light, the tip of the ballpoint pen tip 40 protrudes from the tip of the outer 20 attached to the barrel 10, and the tip of the ball 50 is exposed, as shown in Figure 2. When writing with the ball 50 exposed, writing can be performed with a line width controlled by the ball 50.
[0050] When writing is performed with further application of writing pressure, the connecting portion 63a of the interposed member 63 elastically deforms, and the ballpoint pen tip 40 retracts backward, as shown in Fig. 3. When further writing pressure is applied, the outer tip portion 23 abuts against the writing surface, such as the paper surface, and the retraction of the ballpoint pen tip 40 stops. At that time, ink flows to the outer tip portion 63a along with the ball 50, acting to widen the writing width.
[0051] Therefore, according to the ballpoint pen 1 of the embodiment, it is possible to easily obtain writing in which the line width can be controlled in a manner similar to that of a fountain pen by changing the writing pressure.
[0052] Depending on the amount of force applied when writing, the collector 31 and collector core 32 can bend, and the outer 20 and ink supply unit 30 can be tilted from the central axis of the barrel 10, providing a soft writing feel like that of a fountain pen. In particular, because there is space between the rear insertion hole 24a of the outer 20 and the outer periphery of the ballpoint pen tip 40, the collector core 32 can be easily bent, improving the writing feel.
[0053] Furthermore, by changing the writing pressure and moving the ballpoint pen tip 40 and the collector core 32 back and forth, the space in the connecting portion 63a of the intervening member 63 is repeatedly decompressed and compressed, creating a pumping action, which allows ink to be smoothly supplied to the ballpoint pen tip 40 via the collector core 32, and makes it easy to express the shading of a written line. The shading of a written line is at least a level at which a color difference is clearly discernible by the naked eye under normal dyeing. Specifically, 50 mm was written under conditions of a writing speed of 250 mm / 3 sec, a writing angle of 75°, and a writing load of 150 g, and the spectral reflectance of the drawn line hue at 1 to 2 mm from the beginning and the drawn line hue at 10 to 20 mm from the beginning was measured with a microsurface spectrocolorimeter VSS7700 manufactured by Nippon Denshoku Kogyo Co., Ltd. at a measurement hole of 0.5 mm, and the following conditional formula was satisfied: (L* value of the line drawn from the first 1 to 2 mm) / (L* value of the line drawn from the first 10 to 20 mm) However, if the difference was less than 0.8, it was determined that there was a difference in shading in the drawn lines.
[0054] Although the embodiment has been described using a ballpoint pen as an example of a writing instrument, the writing instrument is not limited to a ballpoint pen, and the present invention can be implemented using a writing instrument equipped with an ink guide core having a guide groove or a fiber-formed core. [Industrial Applicability]
[0055] The present invention can be used in writing instruments such as ballpoint pens and marker pens. [Explanation of symbols]
[0056] 10 shaft cylinder 11 First axis 12 rear axle 13 Ink tank 15 Flange 20 Outer (clamp) 21 Outer fixing part 22 Outer taper 23 Outer tip 24a Rear insertion hole 24b Front insertion hole 30 Ink supply unit 31 Collector 32 Collector core 32a Collector core tip 34 Tip holding part 34a Collector flange 40 Ballpoint Pen Tip 42 Holder (base) 42a Crimping part 50 Writing Ball 60 fittings 61 Central member 61a Insertion hole 61b Central member flange 62 Peripheral parts 63 Intervening members 63a Connecting part 64 void
Claims
1. A ballpoint pen in which ink is supplied from an ink storage compartment at the rear of a barrel by sliding the writing part back and forth against the barrel due to writing pressure applied to the tip of the writing part, wherein a linear groove is formed along the axis on the outer periphery of an air replacement member housed between the ink storage compartment and the writing part, a ferrule that connects to the barrel on the outer periphery of the tip of the writing part, a joint that can compress the space within the compression section as the writing part moves is attached between the air replacement member and the writing part, and when the writing part is in a vertical position and the space within the compression section is compressed, the ferrule can come into contact with the writing surface.
2. 2. The ballpoint pen according to claim 1, which contains an aqueous ink composition for a writing instrument, comprising: a dispersion of colored resin microparticles for aqueous ink, the colored resin microparticles being composed of at least a cyclohexyl (meth)acrylate monomer and a basic dye or an oil-soluble dye, the content of the cyclohexyl (meth)acrylate monomer being 31.6 to 50 mass% based on all polymer components constituting the colored resin microparticles, and the content of the basic dye or the oil-soluble dye being 36.4 to 46.3 mass% based on all polymer components, the colored resin microparticles being dispersed in water; a water-soluble organic solvent; and water.
Citation Information
Patent Citations
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