Notebook

Abstract

To provide a writing instrument having a pen tip having a maximum effective area of a visual recognition portion capable of visually recognizing the writing direction with respect to the entire pen tip without impairing the ink outflow property.SOLUTION: The writing instrument A includes a pen tip 20 having a visual recognition portion that guides ink supplied from a writing instrument main body 10 and can visually recognize the writing direction. The pen tip 20 has a holding body 40 having at least a visual recognition portion, and a writing portion 25 that attaches a writing core 30 having a U-shaped or L-shaped outer shape to the holding body 40. The portion of the writing core 30 that comes into contact with the side surface of the holding body 40 has a rectangular cross section.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a writing instrument having a pen tip capable of visually recognizing the writing direction. More specifically, it relates to a writing instrument having a pen tip with a maximum effective area of a visual recognition portion capable of visually recognizing the writing direction with respect to the entire pen tip without impairing the ink outflow property.

Background Art

[0002] Conventionally, the pen tips of writing instruments such as paint markers and underlining markers are those that enable wide line drawing by providing a wide pen core, and are widely used because they are excellent in the visibility and workability of marking. The pen tips of writing instruments such as line markers generally have capillary action imparted to porous members such as those obtained by aggregating synthetic resin fibers or the like into a rod shape or a sintered body of a polymer, and thereby ink supplied from the shaft body serving as the writing instrument body is led out to the pen tip to enable writing.

[0003] In addition, with the spread of writing instruments that house fluorescent ink in the shaft body serving as the writing instrument body, many writing instruments using pen tips with various structures and shapes that enable wide line drawing have been commercially available, providing users with a wide selection of writing instruments for their uses and making the workability comfortable.

[0004] The applicant of the present application has disclosed a writing instrument having a pen tip that can guide and hold ink supplied from an ink absorber (wick) in the shaft body serving as the writing instrument body, and the pen tip is provided with a visual recognition portion (visible portion) capable of visually recognizing the writing direction (see, for example, Patent Document 1). Since the pen tip of this type of writing instrument can visually recognize the writing portion, it can be stopped firmly at the portion where it is desired to stop after finishing drawing, and can prevent over-drawing and overhang.

[0005] However, the pen tip in the above-mentioned Patent Document 1 has a shape in which the ink guide part and the writing part are integrated, and the material used is a sintered body made by sintering thermoplastic resin particles such as polyethylene. However, because of its complex shape, ink guide from the ink absorber is required for the length of the holder, so the ink guide part needs to be designed to be thick. However, if the ink guide part is made thicker, the visible part is obstructed by the thickened ink guide part, resulting in the problem that the effective area of ​​the visible part relative to the entire pen tip is reduced.

[0006] On the other hand, as prior art for pen tips having a viewing section that allows for the visualization of writing directions other than those described above, the applicant has provided, for example, 1) A writing instrument comprising a porous body whose tip serves as the writing part, an ink guide core for holding the porous body and supplying ink to the writing part, and the ink guide core provided inside the holder, wherein the holder serves as a viewing part from which the writing direction can be seen, and wherein at least one groove is formed on the outer surface of the holder to make the ink guide core appear thinner (see, for example, Patent Document 2). 2) A writing instrument characterized in that the pen tip comprises a porous body which serves as the writing part, and a holder which holds the porous body and has at least one ink guide part for supplying ink to the writing part, and has a relay porous body for supplying ink contained in the writing instrument body to the ink guide part provided on the holder, and the holder is a viewing part which allows the writing direction to be seen, the ink guide part is located approximately in the center and has an ink-impregnated ink supply core provided therein (see, for example, Patent Document 3), 3) A writing instrument having a barrel containing writing ink and a writing section attached to one end of the barrel, wherein the writing section has a writing body that guides writing ink from the barrel and allows writing with the writing ink, and a holder that holds the writing body, the holder is made of a hard material that is visible, the writing body is provided on the holder and when viewed at a specific angle, the visible portion of the writing body is 50% or less of the surface area of ​​the holder (see, for example, Patent Document 4).

[0007] However, while the pen tips described in Patent Documents 2 to 4 above offer a wider visible writing surface through the tip than the conventional Patent Document 1, they still fail to maximize the visible area that allows for visual confirmation of the writing direction across the entire pen tip, and further improvements were desired. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2000-52682 (Claims, Figure 1, etc.) [Patent Document 2] Japanese Patent Publication No. 2018-118420 (Claims, Figure 4, etc.) [Patent Document 3] Japanese Patent Publication No. 2014-50970 (Claims, Figure 1, etc.) [Patent Document 4] Japanese Patent Publication No. 2018-30293 (Claims, Figure 4, etc.) [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] In view of the problems of the prior art described above, the present invention aims to solve these problems and provides a writing instrument having a pen tip that allows the writing direction to be seen, with a pen tip that maximizes the effective area of ​​the visible portion that allows the writing direction to be seen on the entire pen tip without impairing ink flow. [Means for solving the problem]

[0010] As a result of diligent research to solve the above-mentioned conventional problems, the present inventors have found that a writing instrument can be obtained by providing a pen tip with a visible portion that guides the ink supplied from the writing instrument body and allows the writing direction to be visually confirmed, and by giving the pen tip a specific structure, etc., the above-mentioned writing instrument can be obtained, and thus the present invention has been completed.

[0011] In other words, the writing instrument of the present invention comprises a pen tip having a viewing portion that guides ink supplied from the writing instrument body and allows the writing direction to be visually confirmed, the pen tip comprising a holder having at least a viewing portion and a writing portion for attaching a writing lead with an outer shape of U or L to the holder, wherein the portion of the writing lead that contacts the side surface of the holder has a rectangular cross-section. The front end of the holder is preferably formed as a refractive surface. Preferably, the surface of the holder that comes into contact with the pen tip has ribs formed perpendicular to the axis. It is preferable that the aspect ratio of the cross-section of the flow portion in the pen nib is 1:1.2 or greater. Preferably, the aforementioned tip shaft covers the outer circumference of the pen tip. [Effects of the Invention]

[0012] According to the present invention, a writing instrument is provided that maximizes the effective area of ​​the viewing section, which allows the writing direction to be visually confirmed across the entire pen tip, without impairing ink flow. [Brief explanation of the drawing]

[0013] [Figure 1] These are drawings showing a writing instrument according to a first embodiment of the present invention, where (a) is a plan view, (b) is a front view, and (c) is a longitudinal cross-sectional view from the front. [Figure 2] Figure 1 shows an enlarged perspective view of the pen tip, where (a) is an enlarged perspective view of the pen tip seen from one direction, and (b) is an enlarged perspective view of the pen tip seen from the direction 180° rotated from (a). [Figure 3] Figure 1 shows an example of a pen nib used in a writing instrument, where (a) is a plan view, (b) is a front view, (c) is a longitudinal section view from the front, (d) is a bottom view, (e) is a perspective view from the front, (f) is a perspective view from the rear, (g) is a left side view, (h) is a section view of line XX in (b), and (i) is a right side view. [Figure 4]It is a drawing showing an example of a holder at the pen tip used for the writing instrument of FIG. 1. (a) is a plan view, (b) is a front view, (c) is a longitudinal sectional view seen from the front, (d) is a bottom view, (e) is a perspective view seen from the front side, (f) is a left side view, (g) is a sectional view taken along the Y-Y line of (f), (h) is a right side view, and (i) is a perspective view seen from the rear side of the bottom side. [Figure 5] It is a drawing showing the writing instrument of the second embodiment of the present invention. (a) is a plan view, (b) is a front view, and (c) is a longitudinal sectional view seen from the front. [Figure 6] It is an enlarged perspective view of the pen tip of FIG. 5. (a) is an enlarged perspective view of the pen tip seen from one direction, and (b) is an enlarged perspective view of the pen tip seen from the direction where (a) is unfolded by 180°. [Figure 7] It is a drawing showing an example of a pen tip used for the writing instrument of FIG. 5. (a) is a plan view, (b) is a front view, (c) is a longitudinal sectional view seen from the front, (d) is a bottom view, (e) is a perspective view seen from the front side, (f) is a perspective view seen from the rear side, (g) is a left side view, (h) is a sectional view taken along the Z-Z line of (b), and (i) is a right side view. [Figure 8] It is a drawing showing an example of a holder at the pen tip used for the writing instrument of FIG. 5. (a) is a plan view, (b) is a front view, (c) is a longitudinal sectional view seen from the front, (d) is a bottom view, (e) is a perspective view seen from the front side, (f) is a left side view, (g) is a sectional view taken along the V-V line of (f), (h) is a right side view, and (i) is a perspective view seen from the rear side of the bottom side. [Figure 9] (a) and (b) are enlarged partial side views showing the state in which the writing instruments of the first and second embodiments are being written while being tilted. [Figure 10] It is a drawing showing the writing instrument of the third embodiment of the present invention. (a) is a front view, (b) is a longitudinal sectional view, and (c) is an enlarged longitudinal sectional view of the pen tip. [Figure 11] It is an enlarged perspective view of the pen tip of FIG. 10. [Figure 12] It is a drawing showing an example of a pen tip used for the writing instrument of FIG. 10. (a) is a plan view, (b) is a left side view, (c) is a front view, (d) is a right side view, and (e) is a longitudinal sectional view seen from the front. [Figure 13]Figure 10 shows an example of a holder for the nib of a writing instrument, where (a) is a perspective view from the front, (b) is a perspective view from the rear, (c) is a top view, (d) is a left side view, (e) is a front view, (f) is a right side view, and (g) is a longitudinal cross-sectional view from the front. [Figure 14] Figure 10 shows an example of the tip barrel of a pen nib used in a writing instrument, where (a) is a plan view, (b) is a perspective view from the front and above, (c) is a left side view, (d) is a front view, (e) is a right side view, (f) is a longitudinal section view from the front, and (g) to (i) are cross-sectional views of (f) along lines GG, HH, and II. [Figure 15] Figure 10 shows an example of a writing lead in a pen tip used in a writing instrument, where (a) is a perspective view from the front, (b) is a perspective view from the rear, (c) is a plan view, (d) is a left side view, (e) is a front view, (f) is a right side view, (g) is a longitudinal section view from the front, and (h) is a transverse section of the thin plate (sheet) portion. [Figure 16] Figure 15 shows the writing lead before assembly, with (a) being a plan view, (b) a front view, and (c) a longitudinal cross-sectional view from the front. [Figure 17] This is an enlarged partial side view showing the writing instrument of the third embodiment in an inclined position. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described in detail below with reference to the drawings. Figures 1 to 4 show a writing instrument according to the first embodiment of the present invention, and are drawings of a twin-type writing instrument with two types of pen tips. Figure 2 is an enlarged perspective view of the pen tip used in the writing instrument of Figure 1, viewed from various directions, and Figures 3 and 4 are drawings of the individual components that make up the pen tip, such as the writing lead and the holder. As shown in Figures 1(a) to 1(c), the writing instrument A of this embodiment is a twin-type writing instrument equipped with a pen tip 20 that guides ink supplied from the writing instrument body (barrel) 10 and has a viewing section that allows the writing direction to be visually confirmed, and a rod-shaped polyacetal pen tip 50 on the opposite side of the pen tip 20. Furthermore, a cap 60 having a clip portion 60a that protects the detachable pen tip 20 and a cap 70 that protects the pen tip 50 are attached to both sides of the writing instrument body 10.

[0015] The writing instrument body 10 is made of, for example, a thermoplastic resin, a thermosetting resin, etc., and consists of a cylindrical body that houses an ink reservoir 15 impregnated with writing ink. In the drawing, one end on the right side has a holding part 11 with a fitting part for fixing a holder 55 that holds a fine-point rod-shaped pen tip 50, and the other end on the left side has a front barrel 16 attached to which a pen tip 20 having a viewing part that allows the writing direction to be seen is fixed. The writing instrument body 10 is molded into a cylindrical shape using a resin such as polypropylene, and functions as the writing instrument body (barrel). The writing instrument body 10 is molded to be opaque or transparent (and translucent), and either can be used from the viewpoint of appearance or practicality.

[0016] The ink-absorbing body 15 is impregnated with writing instrument ink such as water-based ink or oil-based ink, and includes, for example, fiber bundles made from one or more combinations of natural fibers, animal hair fibers, polyacetal resins, acrylic resins, polyester resins, polyamide resins, polyurethane resins, polyolefin resins, polyvinyl resins, polycarbonate resins, polyether resins, and polyphenylene resins, processed fiber bundles such as felt, and porous bodies such as sponges, resin particles, and sintered bodies. This ink-absorbing body 15 is housed and held within the writing instrument body 10.

[0017] The composition of the ink used for writing instruments is not particularly limited, and a suitable formulation such as water-based ink, oil-based ink, or thermochromic ink can be used depending on the intended use of the writing instrument. For example, in the case of an underline pen, the ink can contain fluorescent dyes, such as Basic Violet 11, Basic Yellow 40, or thermochromic microcapsule pigments. These inks are preferable because, by adjusting the types and amounts of ink components, they achieve an ink viscosity (25°C: complate-type viscometer) of 1-5 mPa·s, a surface tension of 30-60 mN / m, an ink flow rate X from the pen tip 20 of 5-20 mg / m, and an ink flow rate Y from the pen tip 50 of 0.1-5 mg / m, with X > Y, making it easy to differentiate between handwriting styles. The ink flow rate was measured by setting the pen body in an automatic writing device and, in accordance with JIS S6037, on high-quality paper at a writing angle of 65°, a writing force of 1 N, and a speed of 7 cm / s. Furthermore, by making the bending stress of the pen tip 50 higher than that of the pen tip 20, a writing instrument suitable for writing fine characters with the pen tip 50 can be provided. Furthermore, if the ink for the writing instrument is a thermochromic ink, a thermoplastic elastomer with an erasing ability (erasing rate) of less than 70% of pencil lines as specified in JIS S 6050-2002 is formed on the top of the cap 60. This creates a friction body that easily generates frictional heat through rubbing and has low wear, thereby reducing the generation of eraser residue during friction and preventing staining of the surrounding area.

[0018] As shown in Figures 2(a) and (b), and Figures 3(a) to (i), the pen tip 20 is composed of a writing lead 30 having at least a writing portion 25 and a holder 40 having a viewing portion. The writing lead 30 having the writing portion 25 is attached to the holder 40, which will be described later, by adhesive, welding, fitting, etc.

[0019] As shown in Figures 3(a) to (i), the writing lead 30 of this embodiment has a writing section 25 that is inclined (knife-cut) to provide a writing angle that is easy to write with, and thin plate bodies (sheet bodies) 31, 31 extending from both ends of the writing section 25, which are integrally connected, and the outer shape is formed in a substantially U shape (including a U-shape), and the cross-section of the thin plate bodies 31, 31 is rectangular. The writing lead 30 is not particularly limited as long as it efficiently guides (supplies) the ink absorbed in the writing instrument body 10 to the writing section 25 via the thin plates 31, 31. Examples include fabrics such as nonwoven fabric, woven fabric, or knitted fabric, or materials that have liquid permeability such as liquid permeable foam or sintered body. The writing lead 30, including the writing section 25, can be made from a single material, but it can also be made by combining multiple materials, such as by laminating them, or by connecting or joining the writing section 25 and the parts other than the writing section 25 with other components. In the present invention, "nonwoven fabric" refers to a fabric-like structure formed by forming a mass of one or more fibers without weaving or knitting. The fiber material can be synthetic fiber, natural fiber, animal hair fiber, inorganic fiber, etc. Examples of synthetic fiber materials include one or more combinations of polyacetal resin, polyethylene resin, acrylic resin, polyester resin, polyamide resin, polyurethane resin, polyolefin resin, polyvinyl resin, polycarbonate resin, polyether resin, and polyphenylene resin.

[0020] The fibers that make up the fabric can be obtained by known methods such as melt spinning, dry spinning, wet spinning, direct spinning (meltblown, spunbond, electrostatic spinning, etc.), a method of extracting fine fibers by adsorbing one or more resin components from composite fibers, and a method of obtaining divided fibers by beating the fibers.

[0021] The fibers that make up the fabric may consist of one or more types of resin components, and composite fibers, such as core-sheath type, sea-island type, side-by-side type, and orange type, which are generally referred to as composite fibers, can be used.

[0022] The fineness of the fibers constituting the fabric is not particularly limited, but it is preferably 0.1 to 500 dtex (decitex), and more preferably 2 to 5 dtex (decitex). The fiber length is also not particularly limited, but short fibers, long fibers, or continuous fibers can be used. If the fabric is woven or knitted, it can be prepared by weaving or knitting the fibers prepared as described above.

[0023] When the fabric is a nonwoven fabric, methods such as a dry method or a wet method can be used to prepare a fiber web capable of producing a nonwoven fabric. Methods for entangling and / or integrating the fibers constituting the fiber web to form a nonwoven fabric include, for example, entangling by needles or water flow, integrating the fibers with a binder, or, if the fiber web contains a thermoplastic resin, melting the thermoplastic resin by heat treatment of the fiber web to integrate the fibers. Methods for heat treatment of the fiber web include, for example, heating and pressurizing with a calender roll, heating with a hot air dryer, or melting the thermoplastic resin fibers by irradiating with infrared rays under no pressure. Alternatively, the nonwoven fabric may be prepared by collecting fibers spun using a direct spinning method. In the case of permeable foams, they can be prepared by known methods, such as pouring molten resin into a mold for molding and foaming. Sintered bodies can be composed of porous bodies (sintered cores) obtained by sintering plastic powders such as polyacetal resins, polyethylene resins, acrylic resins, polyester resins, polyamide resins, polyurethane resins, polyolefin resins, polyvinyl resins, polycarbonate resins, polyether resins, and polyphenylene resins.

[0024] The shape and thickness of the writing tip 30 having the writing portion 25 are determined based on the manner of attachment to the holder 40, the shape of the writing portion 25, maximizing the viewing area of ​​the viewing portion 43, and efficiently supplying ink to the writing portion. Preferably, the width and length are the width and circumferential lengths of the mounting surface and circumferential length of the holder 40, which will be described later, to which the thin plate bodies 31, 31 of the writing tip 30 are fixed, and lengths suitable for efficiently supplying ink to the writing portion 25 are set accordingly. Furthermore, the thickness t of the thin plate bodies 31, 31 other than the writing portion 25 of the writing tip 30 is preferably 0.3 to 3.0 mm, and most preferably 0.5 to 1.0 mm, based on the point of maximizing the viewing area of ​​the viewing portion 43.

[0025] In this embodiment, the writing section 25 is integrally formed with the thin plate bodies 31, 31 of the writing lead 30, and is inclined (knife-cut) to provide a comfortable writing angle. This inclination and other characteristics are set as appropriate to suit the ease of use for writing, etc. Furthermore, the writing section 25 has a thick line width W, preferably a line width W of 1 mm or more, and more preferably a line width W of 2 mm or more. The writing tip 30, including the writing section 25 of this embodiment, is integrally constructed from a sintered core made by sintering plastic powder.

[0026] In the above embodiment, the writing portion 25 of the writing lead 30 and the thin plates 31, 31 are integrally constructed from the same material. However, the writing portion 25 and the thin plates 31, 31 may be constructed from separate components and connected, joined, or abutted together. The writing portion 25 may be made of, for example, a porous material having pores. Specifically, examples include sponges, sintered bodies, fiber bundles, foams, sponges, felts, and porous materials. Materials used to form the porous body include, for example, natural fibers, animal hair fibers, polyacetal resins, polyethylene resins, acrylic resins, polyester resins, polyamide resins, polyurethane resins, polyolefin resins, polyvinyl resins, polycarbonate resins, polyether resins, and polyphenylene resins. Specifically, the writing portion 25 may be made from a sintered body obtained by sintering various plastic powders, and the thin plates 31, 31 may be made from, for example, nonwoven fabrics, woven or knitted fabrics, or permeable materials such as permeable foams.

[0027] As shown in Figures 3(a) to (i) and 4(a) to (i), the holder 40 fixes the writing portion 25 and thin plate bodies 31, 31 of the writing lead 30 and is fixed to the tip opening of the front shaft 16 of the writing instrument body 10. The holder 40 has a bulging body portion 41, a flange portion 42 on the front side of the body portion 41 that abuts against the end face of the writing instrument body 10, and a viewing portion (visible portion) 43 that allows the writing direction to be seen, and also has front holding portions 44a, 44b on the tip side of the visible portion 43 that hold the tip side (end face) of the writing portion 25. Furthermore, the main body portion 41 is equipped with a rear holding portion 45 connected to the main body portion 41 on its rear side. The entire longitudinal outer surface of the holder 40, which is composed of these components, has a structure attached (arranged) on its outer circumference. Specifically, the entire longitudinal outer surface of the holder 40 has holding grooves 46, 46 formed therein, which fit and hold the thin plate-like parts 31, 31 of the writing lead 30 in a U-shape. In addition, a concave fitting portion 41a is formed on the widthwise outer surface of the main body portion 41.

[0028] Furthermore, the holder 40 has a rectangular cross-section for the portion (thin plate-like body 31, 31) of the writing lead 30 that comes into contact with the side surface of the holder 40, and the outer edge of the visible portion 43, which is the front end of the holder 40, is formed as an inclined bending surface 43a, 43a. By making the portion of the writing lead 30 that contacts the side surface of the holder 40 rectangular in cross-section, the width of the visible portion 43 relative to the cross-sectional area can be increased. Furthermore, by making the outer edges of the visible portion 43 of the holder 40 inclined bending surfaces 43a, 43a, the rectangular cross-section can be made to appear thinner, making the area of ​​the visible portion 43 appear even wider than before.

[0029] The entire holder 40, as configured in this way, is made of a hard material, such as a hard material that is visible, such as glass or a resin that does not have rubber elasticity. As a resin that does not have rubber elasticity and is visible, for example, by molding it from a material with a visible light transmittance of 50% or more, such as PP, PE, PET, PEN, nylon (including amorphous nylon in addition to common nylons such as nylon 6 and nylon 12), acrylic, polymethylpentene, polystyrene, or ABS, the characters written in the writing direction can be effectively seen on the viewing part 43. Alternatively, only the viewing part 43 (including the inclined refractive surfaces 43a, 43a) may be made of a material that is visible. The visible light transmittance can be determined by measuring the reflectance with a multi-light source spectrophotometer [Suga Test Instruments Co., Ltd., (MSC-5N)]. Furthermore, the holder 40 may be constructed using one of the above materials, or two or more materials for further improvements in durability, visibility, etc., and can be molded by various molding methods such as injection molding and blow molding.

[0030] The thin plates 31, 31 of the writing lead 30 are fixed to the mounting surface 47 of the U-shaped retaining groove 46 of the holder 40 by adhesive bonding, welding, etc., and are fixed to the writing section 25. In this embodiment, in order to maximize the viewing area of ​​the viewing section 43, the thickness t of the thin plates 31, 31 is thinner than the thickness of the writing section 25, and the width (m) of the ink guidance section is less than 90% of the width (M) of the viewing section 43 of the holder 40, more preferably 50-80%. Furthermore, in order to further demonstrate the effects of the present invention, the aspect ratio of the cross-section of the thin plates 31, 31 that form the ink guidance section, that is, the ratio of thickness t to width m (t:m), is preferably 1:1.2 or more and less than 10, more preferably 1:2 or more and less than 5.

[0031] In this writing instrument A, the writing portion 25 is fixed (attached) to the holder 40 by fitting and holding the writing portion 25 between the front holding portions 44a and 44b. Furthermore, in order to ensure that the writing portion 25 is fixed (prevents it from coming off), adhesive bonding, welding, etc., may be used.

[0032] As shown in Figures 1(a) and (b), the pen tip 50 is a fine-point, rod-shaped pen tip with a circular cross-section. The rear end of the pen tip 50 (the side facing the ink reservoir) is inserted into the ink reservoir 15, and ink from the ink reservoir is supplied to the pen tip 50 by capillary action. The pen tip 50 is made of a porous material, and for example, it is made of a parallel fiber bundle consisting of one or more types of materials such as natural fibers, animal hair fibers, polyacetal resin, polyethylene resin, acrylic resin, polyester resin, polyamide resin, polyurethane resin, polyolefin resin, polyvinyl resin, polycarbonate resin, polyether resin, and polyphenylene resin, or a fiber core made by processing fiber bundles such as felt or resin processing these fiber bundles, or a porous body (sintered core) made by sintering plastic powder such as thermoplastic resin such as polyolefin resin, acrylic resin, polyester resin, polyamide resin, and polyurethane resin. Preferred pen tip 50 includes fiber bundle cores, fiber cores, sintered cores, felt cores, sponge cores, and inorganic porous cores, with fiber cores being particularly preferred from the viewpoint of deformation moldability and productivity. Furthermore, the porosity, size, hardness, etc. of the pen tip 50 used will vary depending on the type of ink, the type of writing instrument, etc., and for example, a porosity of 30 to 60% is preferred. In the present invention, "porosity" is calculated as follows. First, a writing lead having a known mass and apparent volume is immersed in water and, after being thoroughly soaked in water, the mass is measured when it is removed from the water. From the measured mass, the volume of water soaked into the writing lead is derived. Assuming that this volume of water is the same as the pore volume of the writing lead, the porosity is calculated from the following formula. Porosity (unit: %) = (volume of water) / (apparent volume of pen tip 50) × 100

[0033] In the writing instrument A configured in this way, an ink-absorbing body 15 containing writing ink is inserted and held inside the writing instrument body 10, the pen tip 20 with the above configuration is sequentially fitted and fixed to the front end via the front shaft 16, and the holder 55 to which the pen tip 50 is fixed is fitted and fixed to the other end, thereby easily creating a twin-type writing instrument A. The ink absorbed in the ink-absorbing body 15 is efficiently supplied by capillary action to the writing section 25 and the pen tip 50 via the thin plates 31, 31 of the writing core 30 at the pen tip 20, and is used for writing.

[0034] In this writing instrument A, the nib 50 is the same as that of conventional general-purpose nibs, so the functions of the nib 20 will be explained below. As shown in Figures 1 and 2, the pen tip 20 of this writing instrument A has a viewing section (window) 43 that allows the writing direction to be seen. The ink from the ink reservoir 15 reaches the writing section 25 by the capillary force of the thin plates 31, 31 of the writing core 30 and is used for writing. When writing, looking at the viewing side through the viewing section (window) 43 makes it easier to align the starting position of the stroke and to stop precisely at the desired end point, preventing over-strokes and smudging.

[0035] In this invention, the pen tip 20 guides ink from the ink storage body 15 to the writing section 25 via thin plates 31, 31 of the writing lead 30, which are thinner than the thickness of the writing section 25 and have good ink flow properties. Furthermore, since these thin plates 31, 31 are made of a sheet-like porous material, the ink flow properties are good, there is no need to design it to be thick, the visibility section 43 is not obstructed, and by making the portion of the writing lead 30 that contacts the side surface of the holder 40 rectangular in cross-section, the width of the visibility section 43 relative to the cross-sectional area can be increased, and the outside of the visibility section 43 of the holder 40 By making the periphery an inclined bending surface 43a, 43a, the rectangular cross-section can be made to appear thinner. This allows right-handed users to draw lines with the writing section 25 while visually confirming the writing direction with the viewing section 43 when writing from left to right. In addition, the effective area of ​​the viewing section relative to the entire pen tip is maximized, and ink is efficiently supplied to the writing section 25, which is integrally constructed by the thin plates 31, 31 with the above characteristics. As a result, the ink flow is also good, and a writing instrument is obtained that can maximize the effective area of ​​the viewing section 43 without compromising ink flow. Furthermore, since this writing instrument A has good ink flow, even when writing at a high speed with the pen tip 20 moving, the ink supply keeps up well, resulting in a writing instrument that does not produce smudging or other issues with the writing.

[0036] The writing instrument of the present invention is characterized by having a pen tip 20 with the above configuration; therefore, the configuration other than the pen tip 20 is not particularly limited. Other embodiments of the writing instrument of the present invention will be described below. Figures 5 to 8 are drawings showing other examples of the pen tip 20 in the writing instrument of the second embodiment of the present invention. In the following embodiments, if the writing instrument has the same configuration and function as the writing instrument A of the above embodiment, the same reference numerals will be used in the drawings, etc., and their descriptions will be omitted.

[0037] The 1 Writing instrument of the embodiment A In the above embodiment, the writing lead 30 had a U-shape, but in the second embodiment... Writing instrument BAs shown in Figures 5 to 8, the difference lies in the fact that the L-shaped writing lead 35 is attached to the holder 40. The writing portion 36 of the writing lead 35 in the second embodiment has the same shape as the writing portion of the above embodiment, and is inclined (knife-cut) to provide an angle that is easy to write with. In the writing lead 35, a thin plate body 37 is integrally attached from the end side of the writing portion 36, and its outer shape is formed in an L shape, with a rectangular cross-section of the thin plate body 37. As shown in Figures 5 to 8, the holder 40 fixes the writing portion 36 and the thin plate body 37 of the writing lead 35 and is fixed to the tip opening of the front shaft 16 of the writing instrument body 10. In the embodiment shown in Figure 1, mounting surfaces 47 for attaching the thin plate bodies 31, 31 were formed on the top and bottom, but in this embodiment, since the outer shape is L-shaped, it is attached only to the bottom side of the holder 40. Accordingly, the holder 40, similar to the embodiment in Figure 1, has a bulging main body portion 41, a flange portion 42 that abuts the end face of the writing instrument body 10 on the front side of the main body portion 41, and a viewing portion (visible part) 43 that allows the writing direction to be seen, and also has front holding portions 44a, 44b that hold the tip side (end face) of the writing portion 36 on the tip side of the visible part 43. Furthermore, the main body 41 is provided with a rear holding portion 45 connected to the main body 41 on its rear bottom surface. To maximize the viewing area of ​​the viewing portion 43, a structure is attached (placed) on the bottom surface of the holding body 40. Specifically, a holding groove 46 is formed on the entire longitudinal bottom surface of the holding body 40, which fits and holds the thin plate-like body 37 of the writing lead 35 in an L-shape. In addition, a concave fitting portion 41a is formed on the outer circumferential surface of the main body 41 in the width direction, similar to Figure 1.

[0038] The holder 40 has a rectangular cross-section for the portion (thin plate-like body 37) of the writing lead 35 that comes into contact with the side surface of the holder 40, and the outer edge of the visible portion 43, which is the front end of the holder 40, is formed as an inclined bending surface 43a, 43a. In this writing instrument B, since the writing lead 35 has an L-shape, the thin plate 31 is not attached to the upper side of the viewing area 43, unlike the U-shaped structure in Figure 1. Therefore, there is nothing obstructing the view, and the area of ​​the viewing area can be enlarged. Furthermore, by making the part of the writing lead 35 that contacts the side of the holder 40 rectangular in cross-section, the width of the viewing area 43 relative to the cross-sectional area on the bottom side can be increased. Moreover, by making the outer edges of the viewing area 43 of the holder 40 inclined bending surfaces 43a, 43a, the rectangular cross-section can be made to appear thinner, and the area of ​​the viewing area 43 can be made to appear even wider than in Figure 1.

[0039] The pen tip 20 of this second embodiment is attached in the same way as the writing instrument in Figure 1, and has a viewing section (window) 43 that allows the writing direction to be seen. The ink from the ink reservoir 15 reaches the writing section 35 by the capillary force of the writing lead 36 and is used for writing. When writing, looking at the viewing side through the viewing section (window) 43 makes it easier to align the starting position of the stroke, and also allows you to stop precisely at the desired end of the stroke, preventing over-strokes and smudging. In the second embodiment, the pen tip 20 guides ink from the ink storage body 15 to the writing section 36 via a thin plate 37 of the writing lead 35 that is thinner than the thickness of the writing section 35 and has good ink flowability. Furthermore, since this thin plate 37 is made of a material that has better ink supply capacity than the embodiment in Figure 1, the ink flowability is good, there is no need to design it to be thick, the visibility section 43 is not obstructed, and by making the part of the writing lead 35 that contacts the side surface of the holder 40 rectangular in cross-section, the width of the visibility section 43 relative to the cross-sectional area can be increased, and the holder 40 By making the outer edges of the viewing portion 43 inclined bending surfaces 43a, 43a, the rectangular cross-section can be made to appear thinner. This allows right-handed users to visually confirm the writing direction with the viewing portion 43 while drawing lines with the writing portion 36 when writing from left to right. Furthermore, in addition to maximizing the effective area of ​​the viewing portion relative to the entire pen tip, ink is efficiently supplied to the writing portion 36, which is integrally constructed by the thin plate body 37 with the above characteristics. As a result, the ink flow is also good, and a writing instrument can be obtained that achieves a greater maximization of the effective area of ​​the viewing portion 43 than the embodiment in Figure 1 without compromising ink flow. Furthermore, since this writing instrument B has good ink flow, even when writing at a high speed with the pen tip 20 moving, the ink supply keeps up well, resulting in a writing instrument that does not produce smudging or other issues with the writing.

[0040] As shown in Figures 9(a) and (b), the pen tip shape of the writing instrument A in the first embodiment and the writing instrument B in the second embodiment is preferably configured such that, at the limit writing angle, the guide heights on both sides of the writing lead 30 are in a compressive relationship with respect to the load applied from the writing surface. This configuration allows for even greater strength to be achieved.

[0041] Figures 10 to 15 are drawings showing a writing instrument that is a third embodiment of the present invention. The writing instrument C of this embodiment differs from the writing instrument A of the above embodiment in that the structures of the ink reservoir 15, the front barrel 16, the writing lead 30, the holder 40, and the cap 60 are slightly different. Specifically, as shown in Figures 14(a) to (i), the front shaft 16 is composed of a circular cylindrical body, and comprises at least a flange portion 16a towards the rear of the central part, a rear portion 16b having a fitting step portion on the rear side of the flange portion 16a, a front portion 16c having a fitting step portion on the front side, a covering piece 16d integrally provided at the tip of the front portion 16c that covers at least a part of the outer circumference of the writing lead 30, and elliptical ink-absorbing bodies 15 held at predetermined intervals on the elliptical outer circumference 16e inside the cylindrical body. This writing instrument differs from the above embodiment of writing instrument A in that it is composed of retaining protrusions 16f, 16f…, the retainer 40 has ribs 48, 48… formed on the surface in which the writing lead 30 contacts at predetermined intervals perpendicular to the axis, as shown in Figures 13(a) to (g), and air circulation grooves 49, 49 with circular holes are formed on both longitudinal outer circumferences of the main body 41, the tip shaft 16 and the retainer 40 are fitted together by an arrowhead, as shown in Figure 10(c), and the cap 60 has a friction element 62 made of a thermoplastic elastomer with an erasing ability (erasing rate) of less than 70% of pencil lines as specified in JIS S 6050-2002 fixed to the recess 61 at the top, as shown in Figure 10(b).

[0042] The writing instrument C, configured in this manner, has good ink flow properties, similar to the effects of the writing instrument A described above. It can maximize the effective area of ​​the viewing section 43 without impairing ink flow, and further exhibits the following effects due to slight differences in the structures of the ink reservoir 15, the front barrel 16, the writing tip 30, the holder 40, and the cap 60. The ink-absorbing body 15 has an elliptical shape, and retaining protrusions 16f, 16f… that hold the elliptical ink-absorbing body 15 are formed on the outer circumference 16e inside the front barrel 16, so that the rotation of the ink-absorbing body 15 is suppressed. Furthermore, as shown in Figure 10(c), the front barrel 16 and the retaining body 40 are fixed together by an arrowhead fitting, so that the fixing force of the retaining body 40 to which the writing lead 30 is attached to the writing instrument is further enhanced, resulting in excellent durability.

[0043] As shown in Figures 10(c) and 11, one of the thin plates 31 is covered by the covering piece 16d integrally provided at the tip of the front part 16c of the front shaft 16, thus protecting the outer surface of the thin plate 31 and preventing the ruler from getting dirty when drawing lines with it. When the ink absorbed by the ink-absorbing body 15 is a thermochromic ink, the writing lines are erased by the friction action of the friction element 62 fixed to the top of the cap 60. This friction element is designed to easily generate frictional heat and have low wear, thereby reducing the generation of eraser residue during friction and preventing staining of the surrounding area.

[0044] As shown in Figure 13, the holder 40 has ribs 48, 48... formed at predetermined intervals perpendicular to the axis on the surface in contact with the writing lead 30. This allows the brittle base of the writing lead 30, which may have dimensional variations due to the molding process, to be stably assembled to the holder 40. Furthermore, even if the air pressure inside the writing instrument expands, it can be adjusted by the air circulation grooves 49, 49, eliminating ink leakage. Furthermore, in the writing instrument C, which is a third embodiment of the present invention, compared to the writing instrument A, which is the first embodiment described above, the inclined bending surfaces 43a, 43a formed on the outer peripheral edge of the viewing portion 43 which is the front end of the holder 40 can be omitted, and the effective area of ​​the viewing portion 43 can be maximized even with only a structure in which the portion of the writing lead 30 that contacts the side surface of the holder 40 has a rectangular cross-section. Furthermore, by varying the vertical difference at the rear end of the holder 40, the distance between the writing lead 30 and the holder 40, which have different vertical differences as shown in Figure 12, becomes equal. This prevents only one side of the rear end of the writing lead 30 from bending when it comes into contact with the cotton lining.

[0045] Figure 15 shows various drawings illustrating the writing lead 30 used in the writing instrument C of the third embodiment described above. As shown in Figures 15(a) to (h), the writing lead 30 of this embodiment has a writing section 25 that is inclined (knife-cut) to provide an angle that is easy to write with, and thin plate bodies (sheet bodies) 31, 31 that have inclined portions extending from both ends of the writing section 25, apart from the writing section 25, and these are integrally connected, and the outer shape is formed in a substantially U shape (including a U-shape), and the cross-section of the thin plate bodies 31, 31 is rectangular, which is the same as the writing leads used in the above embodiments of writing instruments A to C, but this embodiment differs in that steps 32, 32 are provided at the boundary between the thin plate bodies (sheet bodies) 31, 31 that serve as the ink guide section and the writing section 25. This is the result. Furthermore, by adopting a flattened shape such as an elliptical cross-section, it is possible to maximize the effective area of ​​the viewing section 43. In this writing lead 30, as shown in Figure 16, steps 32, 32 are provided at the boundary between the thin plate (sheet) 31, 31 which serves as the ink guide and the writing section 25. This prevents the side surface of the thin plate 31 from hitting the corner of the groove when assembling the thin plate 31 after the writing section 25 has been assembled into the groove of the holder, thus further improving ease of assembly. Furthermore, as shown in Figure 16, the strength of the base portions 33, 33 on the inside of the connecting portion between the thin plate (sheet) 31, 31 which serves as the ink guide portion and the writing portion 25 may be further enhanced by applying R-shaped or C-shaped processing as shown in the drawing.

[0046] The writing instrument of the present invention is not limited to the embodiments described above, and can be further modified in various ways without altering the technical concept of the present invention.

[0047] Furthermore, as shown in Figure 17, it is preferable to have a pen tip shape that does not significantly increase the line width even when the writing angle is changed. By using a unique R-shape, such as one in which the writing contact surface is shorter than the width of the pen tip, it is possible to prevent the contact width with the paper surface from increasing drastically with the writing angle when setting the pen tip to draw lines narrower than the width of the pen tip.

[0048] Furthermore, the holder 40 and the writing lead 30 can be fixed by various methods, including fitting, hot-melt adhesive, solvent penetration, ultrasonic welding, reactive adhesive (moisture curing, UV curing, oxygen curing, two-component curing), solvent-based adhesive (soluble synthetic resin, emulsion, rubber), tape, and double-sided tape.

[0049] The porosity of the writing lead 30 is preferably within the following range. The porosity is preferably 30-80%, and more preferably 40-70%. The above method for measuring porosity is to determine the apparent volume of pores by immersion in water. This value was calculated using the formula (1 - (Apparent volume of stomata / Volume of writing lead)) × 100 (%).

[0050] Furthermore, although the writing instruments A to C of the above embodiments are shown as twin-type writing instruments, the pen tip 50 may be omitted (the barrel may be a bottomed cylindrical barrel) and a single-type writing instrument equipped with a pen tip 20 may be used, or a writing instrument in which the pen tip 20 extends and retracts by a click mechanism may be used. In the writing instruments A to C of the above embodiments, the cross-section of the shaft of the writing instrument body is formed as a circular shaft, but it may also be made into an irregular shape such as a triangular shape, a square or more rectangular shape, or an elliptical shape. Furthermore, although the case in which the entire pen tip 20 is made of a transparent material is shown, it is also possible to construct the pen tip 20 using a two-color molded product made of a resin material other than a transparent material, with at least the visible part 43 being made of a transparent material, and the main body part 41 that is attached inside the writing instrument body being made of a resin material other than a transparent material. Furthermore, although the above embodiments were described using inks for writing instruments (water-based inks, oil-based inks, and thermochromic inks), liquid substances such as liquid cosmetics, liquid pharmaceuticals, coating solutions, and correction fluids may also be used. [Examples]

[0051] 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.

[0052] [Example 1] A writing instrument with a nib conforming to the configuration and Figures 1-4 below, and writing ink with the composition described below were used. The dimensions of the nib were as shown below.

[0053] (20-piece pen nib configuration) Made of acrylic resin, with a visible light transmittance of 85%. [Reflectance was measured using a multi-light source spectrophotometer (MSC-5N) manufactured by Suga Test Instruments Co., Ltd., and the visible light transmittance was determined from this.] Dimensions of the viewing area (window) 43 (square): 9mm x 8mm x 5mm x 4mm Width of the visible area M: 3.0 mm Writing core 30: Composition of thin plate bodies 31, 31: Polyethylene sintered core, width direction length m: 2 mm, length direction length: 20 mm, thickness t: 0.5 mm, t:m = 1:4; Writing part 25: Polyethylene sintered core, porosity: 50%, 4 × 3 × 6 mm, T = 3 mm, W = 5.5 mm

[0054] Ink absorbent 15: PET fiber bundle, 85% porosity, φ6 × 77 mm Writing instrument body 10, caps 60, 70: Made of polypropylene (PP) Pen tip 50: Polyester fiber bundle core, 60% porosity, φ2.0 × 40.0 mm

[0055] (Writing instrument ink composition: Ink color: Fluorescent yellow) The following ink composition (total 100% by mass) was used as the ink for the writing instrument. Moisturizer: Trimethylglycine (glycine betaine) 7.5% by mass Pentaerythritol 4.5% by mass Coloring agent: NKW-4805 Yellow (manufactured by Nippon Fluorescent Co., Ltd.) 40.0% by mass Preservative: BioAce (manufactured by Kei-I Kasei Co., Ltd.) 0.3% by mass pH adjuster: Triethanolamine 1.0% by mass Fluorine-based surfactant: Surflon 8111N (manufactured by AGC Seimi Chemical Co., Ltd.) 0.2% by mass Water-soluble organic solvent: Ethylene glycol 3.0% by mass Water (solvent): Deionized water 43.5% by mass Viscosity (25°C): 3.0 mPa·s (Complete viscometer, TOKIMEC TV-20) Surface tension (25°C): 33 mN / m (Automatic surface tension meter, Kyowa Interface Science Co., Ltd., DY-300)

[0056] In the writing instrument using the pen tip 20 of Example 1 according to Figures 1 to 4, the ink from the ink storage body 15 is guided to the writing body 25 by thin, flowable plates 31, 31 that are thinner than the thickness of the writing body 25. Furthermore, the writing core 30, which has an outer shape of U-shape including the writing body 25 and the thin plates 31, 31, is made of a polyethylene sintered core with the above configuration, so the capillary force relative to the porosity is high, and its thickness can be made extremely thin, resulting in good ink flowability, there is no need to design the ink guidance part to be thick, the visibility part 43 is not obstructed, and the part of the writing core 30 that contacts the side surface of the holder 40 has a rectangular cross-sectional shape, The width of the viewing area 43 can be widened, and by making the outer edges of the viewing area 43 of the holder 40 into inclined bending surfaces 43a, 43a, the rectangular cross-section can be made to appear thinner. This allows right-handed users to draw lines with the writing section 25 while visually confirming the writing direction with the viewing area 43 when writing from left to right. In addition, the effective area of ​​the viewing area relative to the entire pen tip is maximized, and ink is efficiently supplied to the writing section 25, which is integrally constructed by the thin plates 31, 31 with the above characteristics. As a result, the ink flow is also good, and it has been confirmed that a writing instrument can be obtained that maximizes the effective area of ​​the viewing area 43 without impairing the ink flow. Furthermore, it was confirmed that writing can be performed without skipping even after being dropped from a height of 1 mm.

[0057] Furthermore, when this writing instrument was set in an automatic writing device and tested according to the test method compliant with JIS S6037, a straight line was written on high-quality paper at a writing angle of 65°, a writing load of 1N, and a speed of 7cm / s. The condition of the written line was then visually inspected. It was found that because the above-mentioned preferred ink composition was used, the ink flow rate of the 20mm pen tip (15mg / m) was also good, and while the drying of the pen tip was suppressed, the drying properties of the line and the low-temperature stability of the ink were excellent, resulting in a function that prevents bleeding and show-through of the line.

[0058] [Example 2] The following components were used: a writing instrument with a nib conforming to Figures 5-8, and ink for writing instruments with the following composition. The dimensions of the nib were as shown below.

[0059] (20-piece pen nib configuration) Except for the fact that the writing lead 35 has the following configuration, it is the same as the writing instrument in the above embodiment, so the explanation will be omitted. The writing instrument body 10, ink absorber 15, holder 40, ink composition, etc. were manufactured in the same manner as or in accordance with Example 1 above. Dimensions of the viewing area (window) 43 (square): 9mm x 8mm x 5.2mm x 4.2mm Width of the visible area M: 3.0 mm Writing core 35: Thin plate body 37 composition: Polyethylene sintered core, width direction length m: 2 mm, length direction length: 20 mm, thickness t: 0.8 mm, t:m = 1:2.5; Writing part 36: Polyethylene sintered core, porosity: 50%, 4 × 3 × 6 mm, T = 3 mm, W = 5.5 mm

[0060] In this writing instrument using the pen tip 20 of Embodiment 2, which conforms to Figures 5-8, the ink from the ink absorber 15 is guided to the writing section 36 by a thin, flowable plate 37 that is thinner than the thickness of the writing section 36. Furthermore, the writing lead 35, which has an L-shaped outer shape including the writing section 36 and the thin plate 37, can be made to appear thinner in its rectangular cross-section by making the L-shaped outer edge of the visible part 43 of the holder 40 an inclined bending surface 43a, 43a. When writing, the user can visually confirm the writing direction with the viewing section 43 while drawing lines with the writing section 36. Furthermore, the effective area of ​​the viewing section relative to the entire pen tip can be further maximized compared to Embodiment 1. In addition, ink is efficiently supplied to the integrally constructed writing section 36 by the thin plate body 37 with the above characteristics, resulting in good ink flow. It was confirmed that a writing instrument can be obtained that maximizes the effective area of ​​the viewing section 43 without impairing ink flow. It was also confirmed that the pen can write without skipping even after being dropped from a height of 1 meter. Furthermore, in this embodiment as well, since the ink flow is good, even when writing at a high speed of movement of the pen tip 20, the ink supply keeps up well, resulting in a writing instrument that does not produce smudging or other issues in the writing. Furthermore, when this writing instrument was set in an automatic writing device and tested according to the test method compliant with JIS S6037, a straight line was written on high-quality paper at a writing angle of 65°, a writing load of 1N, and a speed of 7cm / s. The condition of the written line was then visually inspected. It was found that because the above-mentioned preferred ink composition was used, the ink flow rate of the 20mm pen tip (15mg / m) was also good, and while the drying of the pen tip was suppressed, the drying properties of the line and the low-temperature stability of the ink were excellent, resulting in a function that prevents bleeding and show-through of the line. [Industrial applicability]

[0061] The pen tip of the present invention can be suitably applied as a pen tip for writing instruments of the type known as underline pens, paint markers, oil-based markers, and water-based markers. [Explanation of Symbols]

[0062] 10 Writing instrument body 20 nibs 25 Writing section 30 writing lead 40 Holder 43 Visibility section

Claims

1. A writing instrument comprising a pen tip having a viewing portion that guides ink supplied from the writing instrument body and allows the writing direction to be visually confirmed, wherein the pen tip is fixed to a front barrel attached to the front end of the writing instrument body, and the writing instrument comprises a holder having at least a viewing portion and a writing portion for attaching a U-shaped or L-shaped writing lead to the holder, wherein the portion of the writing lead that contacts the side surface of the holder has a rectangular cross-section, and a covering piece that covers at least a part of the outer circumference of the writing lead is provided at the tip of the front barrel.

2. The writing instrument according to claim 1, characterized in that the front end of the holder is formed as an inclined refractive surface.

3. The writing instrument according to Claim 1, characterized in that the ink is a thermochromic ink, and a thermoplastic elastomer with an erasing ability (erasing rate) of less than 70% of pencil lines as defined in JIS S 6050-2002 is formed on the top of the cap that protects the pen tip.

4. The writing instrument according to claim 1, characterized in that the porosity of the pen tip is 30 to 60%.

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