Notebook

Abstract

To provide a writing instrument capable of easily selecting a usage for suppressing the occurrence of handwriting defects such as faint lines and broken lines in handwriting (drawn lines) and a usage for obtaining handwriting including faint lines.SOLUTION: The writing instrument includes a container body 2 containing ink for writing, a writing body 7 arranged to close a mouth part 2c of the container body, and a cap member 4 detachably attached to the mouth part to cover the writing body, allowing writing on a writing surface by allowing the ink in the container body to seep out from the writing body. The container body includes a bottom portion 2a, a body portion 2b continuous to the bottom portion and erected upward, and a mouth part 2c continuous to the body portion and erected obliquely upward. An intersection angle between an axis Ax1 of the container body orthogonal to a surface of the bottom portion in the container body and an axis Ax2 of the mouth part passing through the center of the mouth part forms an obtuse angle.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a writing instrument that can easily select a usage method capable of suppressing the occurrence of writing defects such as bleeding and line skipping in handwriting (strokes), and a usage method capable of obtaining handwriting including bleeding and the like.

Background Art

[0002] A writing instrument is disclosed in Patent Document 1 in which a liquid such as paint, drawing ink, or ink is contained in a container, and the liquid is exuded from a writing part having a relatively large area provided with continuous pores in a synthetic resin material attached to the mouth of the container. In the writing instrument disclosed in this Patent Document 1, the container for containing a liquid such as ink has a planar bottom surface on which the container can be placed on a horizontal plane, and a body portion is formed continuously from this bottom surface and having an outer diameter that decreases upward. And the above-mentioned writing part is attached so as to cover the mouth part formed at the upper end part of the body part.

[0003] Similar to the writing instrument disclosed in the above-mentioned Patent Document 1, writing instruments that contain a liquid such as ink in a container and exude the liquid from a writing part made of a rubber sponge or the like having a relatively large area attached to the mouth of the container are disclosed in Patent Documents 2 and 3. In the writing instruments disclosed in these Patent Documents 2 and 3, the container is described as being teardrop-shaped. That is, the container body forms a substantially spherical shape, and a cylindrical mouth part is formed by slightly protruding slenderly from a part thereof, and a writing part made of a sponge or the like is attached so as to cover this mouth part.

[0004] In each of the writing instruments disclosed in these patent documents, the axis of the mouth part to which the container body and the writing part are attached is formed on the same straight line. That is, this writing instrument has a structure premised on writing in a posture such that the writing part faces downward with respect to, for example, the paper surface on a desk. This allows for a smooth supply of ink from the container body to the downward-facing writing section, enabling the smooth supply of the necessary amount of ink to a relatively large area of ​​cursive writing. Therefore, it is possible to provide a writing instrument that does not produce smudging, skipped lines, or uneven lines in the handwriting (lines). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2006-123305 [Patent Document 2] Japanese Patent Publication No. 2013-240895 [Patent Document 3] Japanese Patent Publication No. 2013-240896 [Overview of the project] [Problems that the invention aims to solve]

[0006] In recent years, with improvements in the structure of writing instruments and the development of ink compositions, there has been an increase in proposals for writing instruments that enable writing on a writing surface by allowing paints, pigments, inks, etc., to seep out from a writing part such as a sponge with a relatively large surface area, as disclosed in the aforementioned patent documents, and demand for such instruments is also increasing.

[0007] Accordingly, various proposals have been made for this type of writing instrument, with the aim of obtaining a writing instrument that prevents smudging, skipping lines, and uneven lines in the writing by improving the ink supply to the writing part, as mentioned above. However, on the other hand, there is a potential demand for using the aforementioned writing instruments that can produce thick strokes and lines to obtain unique strokes and lines that include smudging and other variations.

[0008] This invention aims to address the aforementioned needs and primarily aims to provide a writing instrument that allows for easy selection between a usage method that suppresses handwriting defects such as smudging and skipped lines, and a usage method that produces handwriting that includes smudging and other imperfections. [Means for solving the problem]

[0009] The writing instrument according to this invention, which was made to solve the aforementioned problems, comprises a container body for containing writing ink and a writing element positioned to close the mouth of the container body. A writing unit equipped with A writing instrument comprising a cap member detachably attached to the mouth portion and covering the writing body, wherein the ink in the container body is released from the writing body to enable writing on the writing surface, the container body is provided with a bottom portion, a body portion that rises upright above the bottom portion and is continuous with the body portion, and the angle of intersection between the axis of the container body perpendicular to the surface of the bottom portion and the axis of the mouth portion passing through the center of the mouth portion constitutes an obtuse angle, The writing unit comprises a valve seat member that is cylindrical and has a valve opening on its front surface, a valve body member that is housed within the valve seat member and has a valve body that is biased by a spring, and a sheet-like writing body that is attached to the front side of the valve seat member and positioned to cover the mouth of the container body. The liquid flow passage that guides the ink in the container body to the writing instrument is Between the valve seat member and the valve body member meandering formed It is characterized by being present.

[0010] In this case, the container body contains an agitation ball for the writing ink, and it is desirable that the diameter of the agitation ball is larger than the diameter of the opening of the writing unit, which supports the writing body and is attached to the mouth of the container, and which faces inward.

[0011] Furthermore, the writing instrument attached with the opening closed is Foam sheet It is desirable that the writing ink be composed of the following materials, and furthermore, titanium dioxide is used in the writing ink. and flocculation control agent It is desirable that it contains [this ingredient].

[0012] On the other hand, in the writing instrument according to this invention, preferably, the container body and the cap member attached to the mouth of the container body are covered in a tightly sealed state by a packaging sheet. Furthermore, the packaging sheet is provided with a slit so that a portion of the packaging sheet covering the cap member can be peeled off by the slit, and the slit is formed parallel to the bottom of the container body, along the smallest cross-sectional portion of the container body between the body and the opening of the container body. [Effects of the Invention]

[0013] According to the writing instrument of this invention described above, the angle of intersection between the axis of the container body perpendicular to the bottom surface of the container body and the axis passing through the center of the mouth of the container body constitutes an obtuse angle. Therefore, for example, when writing with the bottom of the container body facing upwards on a vertical writing surface, sufficient ink can be supplied to the writing instrument placed at the mouth of the container body. Furthermore, when writing with the bottom of the container facing downwards, the supply of ink to the writing instrument can be restricted.

[0014] Therefore, by selecting the orientation of the container body during writing, it is possible to provide a writing instrument that allows users to choose between a usage method that suppresses handwriting defects such as smudging and skipped lines, and a usage method that actively produces handwriting that includes smudging and other imperfections. In addition, the meandering shape of the liquid flow passage that guides the ink from the container body to the writing instrument provides appropriate flow resistance to the ink passing through the passage. This makes it possible to provide a writing instrument that can prevent sudden leakage of liquid from the writing instrument, especially when using liquids with low viscosity and surface tension as ink. [Brief explanation of the drawing]

[0015] [Figure 1] The overall external configuration of the writing instrument according to this invention is shown, with (A) being a front view, (B) a side view, (C) a rear view, (D) a top view, and (E) a bottom view. [Figure 2] Similarly, the overall external configuration of the writing instrument is shown; (A) is a perspective view taken from the front along the right side, and (B) is a perspective view taken from the right side along the back. [Figure 3] It is an enlarged longitudinal sectional view of the writing instrument cut at the center portion as a whole. [Figure 4] It shows an external appearance configuration in which the writing instrument is covered with a packaging sheet, (A) is a perspective view in a state of covering the whole, and (B) is a perspective view in a state of peeling off a part of the packaging sheet from the cut. [Figure 5] It shows an assembly view of a writing unit attached to the mouth portion of the container body, (A) is a perspective view seen from the writing body side of the front, (B) is a central sectional view, and (C) is a perspective view seen from the back side. [Figure 6] It is an enlarged sectional view explaining the action of the liquid flow path provided in the writing unit. [Figure 7] It shows the single-piece configuration of the valve seat member, (A) is a side view, (B) is a longitudinal sectional view, (C) is a perspective view seen from the front side, and (D) is a perspective view seen from the back side. [Figure 8] It shows the single-piece configuration of the valve body member, (A) is a front view, (B) is a side view, (C) is a perspective view seen from the front side, (D) is a perspective view seen from the back side, and (E) is a central sectional view. [Figure 9] It shows the single-piece configuration of the writing body, (A) is a perspective view seen from the front side, (B) is a perspective view seen from the back side, and (C) is a central longitudinal sectional view. [Figure 10] It shows a state in which a part is deformed when the writing body shown in Fig. 9 is attached to the writing instrument, (A) is a front view, (B) is a side view, and (C) is a central longitudinal sectional view. [Figure 11] It shows the single-piece configuration of the writing body support ring, (A) is a back view, (B) is a perspective view seen from the back side, and (C) is a central sectional view. [Figure 12] It shows the single-piece configuration of the cap member, (A) is a perspective view seen from the front side, (B) is a central sectional view, and (C) is a perspective view seen from the back side. [Figure 13] It shows the usage state of the writing instrument, (A) is a side view showing an example of writing with the bottom of the container body upward, and (B) is a side view showing an example of writing with the bottom of the container body downward.

Embodiments for Carrying Out the Invention

[0016] The writing instrument according to this invention will be described based on the embodiment shown in the figure. Figures 1 to 3 show the overall configuration of the writing instrument according to this invention, with Figure 3 being an enlarged cross-sectional view. Therefore, the overall configuration of the writing instrument according to this invention will first be explained based on Figure 3. In the following diagrams, the same parts are indicated by the same reference numerals. However, in some diagrams, due to space limitations, representative parts are indicated by different reference numerals. Details of each part will be explained by referring to the reference numerals used in the diagrams showing the individual component configurations.

[0017] The writing instrument 1 according to this invention is equipped with a bottle-shaped container body 2 for containing writing ink (not shown), as shown in Figures 1 to 3. The container body 2 is made of a flat plate with an elliptical bottom 2a (see Figure 1(E)) so that it can be placed on a horizontal surface, and a body portion 2b is formed that stands upright at the top, continuous with the bottom 2a. This body portion 2b constitutes an inclined body portion 2b1 in which the upright surface on the front side of the container body 2, that is, the upright surface on the left side of the container body 2 as shown in Figure 3, decreases in diameter towards the center of the container body 2 as it rises upward. Furthermore, the upright surface on the back side of the container body 2, that is, the upright surface on the right side of the container body 2 as shown in Figure 3, constitutes an upright body portion 2b2 that is substantially perpendicular to the bottom portion 2a mentioned above.

[0018] Furthermore, a neck portion 2b3 is formed at the upper part of the upright body portion 2b2, which curves toward the front side of the container body 2, and a cylindrical mouth portion 2c is integrally formed along the curved surface of this neck portion 2b3, rising diagonally upward. As a result, the intersection angle between the axis Ax1 of the container body 2, which is perpendicular to the surface of the bottom portion 2a of the container body 2, and the axis Ax2 of the opening portion 2c, which passes through the center of the opening portion 2c, is obtuse. In the illustrated example, the intersection angle between the axis Ax1 of the container body 2 and the axis Ax2 of the opening portion 2c is set to approximately 120 degrees.

[0019] Furthermore, the mouth portion 2c is configured to be located directly above the inclined body portion 2b1, which, as explained earlier, narrows in diameter towards the center of the container body 2 as it rises upward. This ensures that the weight balance is considered so that the center of gravity of the entire writing instrument 1, including the writing unit 3 (described later) attached to the mouthpiece 2c, does not shift to the front side of the container body 2 where the mouthpiece 2c is formed. In addition, multiple finger-receiving recesses 2d are formed on the front and back sides of the container body 2, allowing the fingertips to be placed when the container body 2 is grasped. These finger-receiving recesses 2d function as an anti-slip feature when the container body 2 is grasped.

[0020] The container body 2 is preferably molded from a flexible synthetic resin. This results in a squeeze container that can be deformed by lightly pressing the left and right sides of the container body 2 with a hand or the like.

[0021] Furthermore, the writing unit 3, which is attached to the mouth portion 2c of the container body 2, has a writing body 7 (described later) that allows writing by releasing ink from inside the container body 2, positioned in a state that closes the mouth portion 2c. Then, a cap member 4 that covers the writing body 7 is detachably attached using the male thread 2e formed on the circumferential surface of the cylindrical portion that constitutes the mouth portion 2c, thereby forming the writing instrument 1.

[0022] Figure 4 shows the external appearance of the writing instrument 1 covered with the packaging sheet 11, and in Figure 4, the packaging sheet 11 is shown with hatching. The packaging sheet 11 is made of a heat-shrinkable resin sheet molded into a cylindrical shape, for example, and is tightly fitted to the outer casing of the writing instrument 1. Figure 4(A) shows the entire writing instrument 1 covered with the packaging sheet 11, indicating that the product (writing instrument 1) is unused. Figure 4(B) shows the product (writing instrument 1) ready for use, with the cap release sheet 11b separated from the body side sheet 11a using the dotted lines 11c on the packaging sheet 11.

[0023] Furthermore, it is desirable that the dashed cuts 11c made in the packaging sheet 11 be pre-formed in a portion of the heat-shrinkable resin sheet. When the resin sheet is heat-shrinkable and in close contact with the container body 2, the position of the dashed cuts 11c is set to be parallel to the bottom 2a of the container body 2, along the smallest cross-sectional portion of the container body 2 between the body portion 2b and the opening portion 2c of the container body 2 as shown in Figure 3. By setting the position of the dashed cuts 11c in this way, the majority of the outer casing of the container body 2, which has a special shape, can be covered by the body-side sheet 11a. Therefore, by pre-printing the product name and logo of the writing instrument 1 on the heat-shrinkable resin sheet corresponding to the main body sheet 11a, it becomes possible to provide a writing instrument 1 with the product name and logo displayed, utilizing the large area of ​​the main body sheet 11a.

[0024] Figure 5 shows a writing unit 3 attached to the mouth 2c of the container body 2. This writing unit 3 consists of a valve seat member 5 which is cylindrical and has a valve opening on its front surface, a valve body member 6 which is housed inside the valve seat member 5 and has a valve body that is biased by a spring, a sheet-like writing body 7 which is attached to the front side of the valve seat member 5 and positioned to cover the mouth 2c of the container body 2, and a writing body support ring 8 which attaches the peripheral edge of the writing body 7 to the valve seat member 5. Figure 6 shows the state in which writing pressure is applied to the writing body 7 of the writing unit 3 shown in Figure 5, causing the inner stopper (valve valve) 3b, which will be described later, to open. This is an enlarged cross-sectional view illustrating the liquid flow passage 3a provided in the writing unit 3 to ensure the correct ink flow rate in this state. The function of this liquid flow passage 3a will be explained later.

[0025] In the following, each of the aforementioned components constituting the writing unit 3 will be described based on the drawings showing their individual components. Figure 7 shows the individual components of the valve seat member 5 that make up the writing unit 3. The valve seat member 5 is formed in a cylindrical shape overall, with its front portion closed and a valve opening 5a in its center. The area around this valve opening 5a is tapered, with the inner diameter decreasing towards the front side. The frustoconical valve body 6c of the valve body member 6, which will be described later, is fitted onto this valve opening 5a to close the valve. The outer circumferential surface of the valve seat member 5 is formed to have the same diameter along the axial direction, forming a fitting portion 5b into the mouth 2c of the container body 2. A tapered portion 5c is formed along the rear half of the tapered portion 5c, slightly reducing the outer diameter. This tapered portion 5c functions as a guide when attaching the writing unit 3 to the mouth 2c of the container body 2.

[0026] On the front side of the fitting portion 5b of the valve seat member 5, a flange portion 5d with a larger diameter than the fitting portion 5b is formed, and this flange portion 5d abuts against the front end of the mouth portion 2c of the container body 2 and serves the function of positioning the writing unit 3. Furthermore, an annular locking portion 5e is formed within the opening at the rear end of the valve seat member 5, protruding inward. This annular locking portion 5e functions as a stopper to prevent the valve body member 6, which will be described later, from falling out when it is installed inside the valve seat member 5. Furthermore, an annular projection 5f is formed on the front side of the valve seat member 5, which supports the writing instrument 7 (described later) from its rear side and serves to position the writing instrument 7.

[0027] As shown in the cross-sectional view in Figure 7(B), two annular protrusions 5g and 5h are formed concentrically inside the valve seat member 5, surrounding the valve opening 5a. These two annular protrusions 5g and 5h are formed to be at the same height toward the rear end of the valve seat member 5, thereby forming an annular groove 5j between the two annular protrusions 5g and 5h. These annular protrusions 5g, 5h and the annular groove 5j, in combination with the valve member 6 described below, form a liquid flow passage 3a that guides the ink inside the container body 2 towards the writing instrument 7.

[0028] Figure 8 shows the individual components of the valve body member 6 that make up the writing unit 3. The valve body member 6 is integrally molded from elastic synthetic resin and is equipped with a single spring body 6b that extends spirally upward from a ring body 6a. A frustoconical valve body 6c is formed at the upper end of this spring body 6b. A valve stem 6d is molded in the center of the valve body 6c so as to protrude from the valve body 6c. Furthermore, as shown in Figure 8(E), an annular projection 6e is formed surrounding the frustoconical valve body 6c, and an annular groove 6f is formed between this annular projection 6e and the annular circumferential surface surrounding the valve body 6c.

[0029] The outer diameter of the aforementioned ring body 6a is approximately equal to the inner diameter of the cylindrically formed valve seat member 5, and is slightly larger than the inner diameter of the annular locking portion 5e. Therefore, by inserting and pushing the valve stem 6d of the valve body member 6 from the annular projection 5e side at the rear end of the valve seat member 5, the rear ring body 6a overcomes the annular locking portion 5e of the valve seat member 5 and is housed inside the valve seat member 5. The ring body 6a of the valve body member 6 is then positioned inside the valve seat member 5 while locked to the annular locking portion 5e of the valve seat member 5 [see Figure 5(B)]. As a result, the valve body 6c comes into contact with the valve opening 5a, closing the valve, while the central valve stem 6d protrudes slightly forward from the valve opening 5a.

[0030] As described above, when the valve body member 6 is attached to the valve seat member 5, the aforementioned annular projection 6e of the valve body member 6 is accommodated in the annular groove 5j formed in the valve seat member 5, and the annular projection 5h of the valve seat member 5 is accommodated in the annular groove 6f of the valve body member 6. As a result, a meandering liquid flow passage 3a is formed between the valve seat member 5 and the valve body member 6, as shown by the arrows in Figure 6 indicating the flow of ink. This meandering liquid flow passage 3a is formed immediately before the plug (valve valve) 3b, which is formed between the valve opening 5a of the valve seat member 5 and the valve body 6c of the valve body member 6.

[0031] According to the liquid flow passage 3a described above, the total length of the gap formed between the annular projections 5g and 5h of the valve seat member 5 and the annular projection 6e of the valve body member 6 changes in response to the retraction movement caused by the writing pressure applied to the valve body member 6. In other words, as the writing pressure applied to the valve body member 6 increases, the total length of the gap in the liquid flow passage 3a decreases. This reduces the flow resistance to the ink, making it possible to control the amount of ink supplied in the liquid flow passage 3a, which cannot be properly controlled by the degree of opening and closing of the aforementioned stopper (valve) 3b. Furthermore, when a liquid with particularly low viscosity and surface tension is used as the ink, the liquid flow passage 3a can suppress excessive ink flow with appropriate flow resistance, thereby providing a writing instrument that can prevent sudden liquid leakage from the writing body 7.

[0032] Figure 9 shows the individual components of the cursive writing font 7 that make up the writing unit 3. This cursive font 7 is formed using a flexible foamed sheet material. This foamed sheet material can preferably be open-cell urethane or polyethylene, or even rubber sponge; however, from the viewpoint of durability, foamed urethane is preferred. This cursive writing 7 is made from the aforementioned foam sheet material cut into a circular shape, and in accordance with the shape of the front side of the valve seat member 5, a spherical convex portion 7a is formed in the center, a short cylindrical portion 7b is formed around the periphery of the spherical convex portion 7a, and an annular flange portion 7c is formed outward at the end of the cylindrical portion 7b. Furthermore, the portion of the cursive writing 7 that forms the spherical protrusion 7a in the center retains the same thickness as the aforementioned foamed sheet material, while the short cylindrical portion 7b and flange portion 7c around its periphery are formed, for example, by press working, so that they are thinner than the spherical protrusion 7a.

[0033] Figure 10 shows the cursive writing font 7 shown in Figure 9 in a partially deformed state after being attached to the writing unit 3 shown in Figure 5. In other words, on the back side of the aforementioned spherical protrusion 7a, a recess 7d is formed, which is deformed by the tip of the valve stem 6d that protrudes from the central part of the valve seat member 5, as shown in Figure 10(C). Furthermore, on the back side of the spherical protrusion 7a, an annular recess 7e is formed along the inside of the cylindrical portion 7b, surrounding the aforementioned central recess 7d. This is deformed when the annular projection 5f that protrudes from the front side of the valve seat member 5 comes into contact with it. Furthermore, on the front side of the annular flange portion 7c, numerous recesses 7f are formed by multiple small protrusions 8d that are formed on the support ring 8 side, which is deformed by being pressed by the cursive writing support ring 8 described later. In addition, on the back side of the flange portion 7c, a groove 7g is formed, which is deformed by being pressed by the valve seat member 5.

[0034] Figure 11 shows the individual components of the writing support ring 8 that makes up the writing unit 3. The support ring 8 supports the surface-shaped cursive writing instrument 7 along its periphery by pressing the periphery of the cursive writing instrument 7, which is attached to the front surface of the valve seat member 5, along the front side periphery of the valve seat member 5. This support ring 8 is molded from a resin material and has a tapered surface 8a whose outer diameter slightly decreases from the back side to the front side. Inside it, an annular first stage 8b and a second stage 8c are molded concentrically, with their inner diameters decreasing from the back side to the front side.

[0035] Furthermore, the second stage portion 8c has a series of small protrusions 8d that project toward the rear side, formed continuously along its circumference. Therefore, the writing body 7, which is pressed against the front surface of the valve seat member 5 by this support ring 8, is supported by the multiple small protrusions 8d so as not to loosen. This support ring 8 is welded along the flange portion 5d of the valve seat member 5 to form the writing unit 3 shown in Figure 5. The writing unit 3 is then attached to the mouth 2c of the container body 2 using the tapered portion 5c of the valve seat member 5, and fitted and installed inside the mouth 2c of the container body 2 by the fitting portion 5b of the valve seat member 5 [see Figure 3].

[0036] Figure 12 shows the individual components of the cap member 4. This cap member 4 has a cylindrical shape with its end closed by a top surface 4a, and its outer circumferential surface is continuously provided with numerous knurled grooves 4b that are groove-shaped indentations along the axial direction. Furthermore, a female thread 4c is provided on the inner circumferential surface on the opening side, and a ring-shaped projection ring 4d is formed on the back side of the top surface 4a, located behind the female thread 4c, projecting in the axial direction.

[0037] As shown in Figure 3, the cap member 4 is attached to the mouth 2c of the container body 4 by screwing the female thread 4c of the cap member 4 onto the male thread 2e of the mouth 2c. This allows the writing instrument 1 to be stored with the writing body 7 of the writing unit 3 covered. At this time, the protruding ring 4d inside the cap member 4 comes into contact with the writing body support ring 8 of the writing unit 3, sealing the writing body 7, and thus suppressing the evaporation of the ink solvent from the writing body 7.

[0038] In the aforementioned writing instrument 1, as shown in Figure 3, writing ink (not shown) is contained within the container body 2 along with a stirring ball 9. The stirring ball 9 is made of hard ball or glass ball, and it is preferable to select a ball diameter D1 of the stirring ball 9 that is larger than the opening diameter D2 facing inward of the writing unit 3 which supports the writing body 7 and is attached to the mouth portion 2c. In other words, in this embodiment, as shown in Figure 3, the ball diameter D1 of the stirring ball 9 is selected to be larger than the inner circumference diameter D2 of the annular locking portion 5e of the valve seat member 5. This allows the large-diameter, heavy stirring ball 9 to effectively stir the sedimentation of the coloring agent in the writing ink used in this type of writing instrument, which has a relatively wide line width. This helps to prevent unevenness in the writing line (uneven coloring, etc.).

[0039] A preferred writing ink to be contained in the container body 2 is an ink composition comprising at least pigment particles, wet silica, hydrated kaolin, a flocculation control agent, and water, wherein the pigment particles contain titanium dioxide, and the content of the flocculation control agent is 0.05% to 1.0% by mass, based on the total mass of the writing ink.

[0040] Examples of pigment particles include inorganic pigments such as metal oxides or metal salts, and organic pigments such as organic dye pigments or lake pigments. Among inorganic pigment particles, metal oxide particles are particularly preferred. Titanium dioxide is particularly preferred because, being white, it can be combined with complementary pigments, as described later, to achieve a wide range of colors. Furthermore, using titanium dioxide with an alumina surface treatment is particularly preferred because it improves dispersion stability. In addition, glossy, lustrous pigments, such as aluminum pigments, can also be used as pigments. The average particle size of the pigment particles is preferably 0.1 μm to 10 μm. The average particle size described herein can be measured by the particle size (D50) at 50% volume accumulation of the particle size distribution measured by laser diffraction using a laser diffraction particle size distribution analyzer (product name "MicrotracHRA9320-X100", Nikkiso Co., Ltd.). Unless otherwise specified, this refers to the average particle size based on volume. The pigment particle content in the ink composition is preferably 10 to 40% by mass, based on the total mass of the ink composition. If the pigment particle content is within the above numerical range, a decrease in ink ejection performance can be prevented, and the opacity of the ink composition and the writing formed using it can be maintained.

[0041] Wet silica is amorphous silica synthesized by a wet process, consisting of aggregated primary particles of several to tens of nanometers in size, and secondary particles of several to tens of micrometers in size, which are difficult to form as primary particles through dispersion. In this invention, wet silica has a higher specific surface area and more silanol groups on its surface compared to dry silica, and therefore forms a loose crosslinking network through interaction with pigment particles. As a result, it can form loose, bulky aggregates with flocculation control agents and flocculation dispersants, and by including wet silica in the ink composition, the dispersion stability of pigment particles is improved, and the redispersibility of the aggregates can be further improved. On the other hand, when dry silica is used, dispersion stability can be maintained, but even a small amount of addition causes structural viscosity, increasing the ink viscosity, which is undesirable. Furthermore, when paper is used as the writing surface, wet silica exhibits a strong sealing effect, preventing pigment particles from penetrating between the paper fibers, and when used in combination with hydrated kaolin, as described later, it enhances the color development of the writing. The average particle size of wet silica is preferably 1 μm to 5 μm. If the average particle size of wet silica is within the above range, stable dispersion in the ink composition is possible, and a high effect of suppressing pigment sedimentation can be obtained. The content of wet silica in the ink composition is preferably 1% to 3% by mass, based on the total mass of the ink composition.

[0042] The flocculation control agent binds to the relatively low-density aggregates formed by the wet silica described above, and further disperses hydrated kaolin and extenders, described later, in the ink composition to create bulky aggregates. This flocculation control agent prevents the ink composition from becoming a hard cake and improves redispersibility by creating bulky aggregates. As the flocculation control agent, for example, a cellulose derivative can be used, and two or more cellulose derivatives can be used in combination. Examples of cellulose derivatives include carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxypropylethylcellulose, and their salts. The content of the flocculation control agent in the ink composition is preferably 0.1 to 0.5% by mass, based on the total mass of the ink composition.

[0043] Hydrated kaolin is a flat or plate-shaped natural clay mineral mainly composed of aluminum silicate containing crystal water, obtained by refining kaolin clay, a natural clay mineral. In the present invention, as described above, hydrated kaolin has a flat or plate-shaped particle form. Therefore, when paper is used as the writing surface, the inclusion of hydrated kaolin in the ink composition provides a strong sealing effect, preventing pigment particles from penetrating between the paper fibers and further enhancing the color development of the writing. Furthermore, because hydrated kaolin is uniformly dispersed in the ink composition within relatively low-density aggregates formed by pigment particles, wet silica, and a flocculation control agent, it creates bulky aggregates despite their relatively low density, thus improving redispersibility compared to the case where calcined kaolin is used. Furthermore, due to its flat or plate-like particle shape, hydrated kaolin is placed parallel to the paper surface when writing, preventing scratching of the paper even when writing over it, thus allowing writing without damaging the paper. The average particle size of hydrated kaolin is preferably 0.5 μm to 2 μm. If the average particle size of hydrated kaolin is within the above range, the redispersibility of the ink composition and the color development of the writing can be improved, and the paper surface can be prevented from being damaged. The content of hydrated kaolin in the ink composition is preferably 5% to 15% by mass, based on the total mass of the ink composition. If the content of hydrated kaolin is within the above range, the ink viscosity will not become too high, hard cake formation will not occur, and the paper surface can be prevented from being damaged when writing. Furthermore, the opacity of the ink composition and the writing formed using it can be maintained.

[0044] In addition, other components such as resins, flocculants / dispersants, extenders, complementary pigments, surfactants, preservatives, wetting agents, defoamers, rust inhibitors, pH adjusters, bubble inhibitors, bubble absorbers, shear viscosity reducers, and viscosity modifiers may be added as needed, provided they do not affect the performance of the ink as a writing instrument ink.

[0045] The viscosity of the ink composition is preferably 1 to 20 mPa·s. The viscosity of the composition can be measured using a rotational viscometer (TV-20, manufactured by TOKIMEC) at 25°C and 10 rpm. If the viscosity of the ink composition is within the above numerical range, the ink ejection performance when used in writing instruments such as markers can be improved, and the writing performance on non-permeable recording media such as films can also be improved.

[0046] Furthermore, it can contain not only writing instrument inks, but also low-viscosity liquids such as alcohols like ethanol and isopropanol, polyhydric alcohols like propylene glycol and dipropylene glycol, and purified water. Various components can be appropriately blended into the liquid depending on the application. In the case of pharmaceuticals, examples include anti-inflammatory and analgesic components (e.g., felbinac, indomethacin, glycol salicylate), antihistamines (e.g., diphenhydramine hydrochloride, chlorpheniramine maleate), blood circulation promoting components (e.g., vanillylamide nonanoate), cooling agents (e.g., l-menthol), and other preservatives, stabilizers, and pH adjusters. In the case of cosmetics, examples include antiperspirant components (e.g., aluminum chlorohydrate, zinc paraphenolsulfonate), antibacterial components (e.g., benzalkonium chloride, benzethonium chloride), deodorant components (e.g., Sophora flavescens extract), and fragrances. The viscosity of this liquid is preferably 1 to 1000 mPa·s. The viscosity of a liquid can be measured, for example, using a B-type viscometer (Brookfield DV-II) with a T-E1 rotor at a rotation speed of 6 rpm.

[0047] Furthermore, when the liquid content described above is used, the cursive writing material is made of low-density polyethylene, which has excellent absorption and release properties of the liquid, as well as good strength and texture. The low-density polyethylene may be either high-pressure low-density polyethylene or linear low-density polyethylene, and its density is usually 0.910 to 0.930 g / cm³. 3The average pore size is preferably 50 to 180 μm, as if it is too large, the retention of the impregnated coating liquid decreases and dripping is likely to occur, while if it is too small, the permeability and release of the coating liquid decreases. The average pore size is measured using a mercury intrusion porosimeter. In addition, the bulk density of the coated material (the weight of the coated material divided by its apparent volume) is preferably 0.15 to 0.25 g / cm³, as if it is too large, the permeability and release decreases, while if it is too small, the retention of the coating liquid decreases. 3 This is preferable. Furthermore, it is preferable that the material consists of an open-cell foam with an open-cell ratio of 70% or more, as measured in accordance with ASTM D 1940-62T, which can further improve the absorption, release, and retention of the coating liquid. As for the thickness of the writing material, if it is too large, deformation due to swelling will be greater and the release of the coating liquid will decrease, while if it is too small, the texture will deteriorate, so a thickness of 0.5 to 3.5 mm is preferable.

[0048] The writing unit 3 of the writing instrument 1 according to this embodiment includes an inner plug (valve valve) 3 formed by the valve opening 5a of the valve seat member 5 and the valve body 6c of the valve body member 6. b It is installed. Therefore, by pressing the writing tip 7 against the writing surface, the valve stem 6d of the valve member 6 can be retracted against the biasing force of the spring body 6b via the writing tip 7. This releases the seal of the valve body 6c on the valve opening 5a, and the ink in the container body 2 is supplied to and absorbed by the writing tip 7. Then, the ink seeps out from the writing tip 7 toward the writing surface, and writing is performed. In this case, the inner stopper 3 b A meandering ink flow passage 3a is formed immediately before this point, and as explained earlier, this liquid flow passage 3a can suppress excessive ink flow and prevent a sudden outflow of liquid from the cursive writing 7.

[0049] Figure 13 shows an example of the usage state of the writing instrument 1 according to this invention. In this example, (A) shows the case where writing is performed with the bottom 2a of the container body 2 facing upwards relative to the vertical writing surface 15, and (B) shows the case where writing is performed with the bottom 2a of the container body 2 facing downwards relative to the vertical writing surface 15.

[0050] As shown in Figure 13(A), when writing with the bottom 2a of the container body 2 facing upwards on a vertical writing surface 15, sufficient ink can be supplied to the writing instrument 7 positioned at the mouth 2c of the container body 2. This makes it possible to draw while suppressing handwriting defects such as smudging and skipped lines. Furthermore, as shown in Figure 13(B), when writing is performed with the bottom 2a of the container body 2 facing downwards on a vertical writing surface 15, the supply of ink to the writing instrument 7 can be restricted. This makes it possible to obtain drawings that include smudging or other imperfections in the handwriting (lines).

[0051] In the above-described embodiment, the writing unit attached to the mouth portion 2c of the container body 1 includes an inner stopper (valve valve) 3 which includes a valve opening 5a and a valve body 6c. b Although a configuration with the aforementioned stopper is employed, the writing instrument according to this invention does not necessarily require the aforementioned stopper and can also be used in a direct-ink type writing instrument in which the ink in the container body 1 directly permeates the writing instrument 7. [Explanation of symbols]

[0052] 1 writing implements 2. Container body 2a bottom 2b Torso 2c Mouth 2d finger rest recess 3 Writing Units 3a Liquid flow path 3b. Inner plug (valve valve) 4 Cap Member 4a Top surface 5 Valve seat member 5a Benguchi 5e Annular locking section 5g, 5h Annular protrusion 5j annular groove 6 Valve body member 6b Spring body 6c valve body 6d valve stem 6e Annular projection 6f Annular groove section 7 Cursive 7a Spherical protrusion 8. Cursive writing support rings 9 Mixing ball 11 Packaging sheets 11a Main unit side sheet 11b Release sheet on the cap side 11c cut 15 Writing surface

Claims

1. A writing instrument comprising a container body for containing writing ink, a writing unit having a writing body positioned to close the mouth of the container body, and a cap member detachably attached to the mouth and covering the writing body, wherein writing is made possible on a writing surface by causing the ink in the container body to seep out from the writing body, The container body is provided with a bottom, a body portion that rises upright above the bottom and is continuous with the body, and a mouth portion that rises diagonally upward and is continuous with the body. The angle of intersection between the axis of the container body perpendicular to the bottom surface of the container body and the axis of the opening passing through the center of the opening constitutes an obtuse angle, The writing unit comprises a valve seat member that is cylindrical and has a valve opening on its front surface, a valve body member that is housed within the valve seat member and has a valve body that is biased by a spring, and a sheet-like writing body that is attached to the front side of the valve seat member and positioned to cover the mouth of the container body. A writing instrument characterized in that the liquid flow passage that guides the ink in the container body to the writing instrument is formed in a meandering manner between the valve seat member and the valve body member.

2. The writing instrument according to claim 1, characterized in that the writing body attached to close the mouth is made of foamed sheet material.

3. The writing instrument according to claim 1, characterized in that the writing ink contains titanium dioxide and a flocculation control agent.

Images