Notebook

Abstract

To provide a writing instrument that can contribute to environmental protection by eliminating plastic by using a material that includes a paper base material for an ink storage container.SOLUTION: A writing instrument 1 includes a container body 2 containing ink, a writing portion 62 disposed at a mouth portion 29 of the container body, and a detachable cap member 68 that covers the writing portion. By causing the ink inside the container body to ooze out from the writing portion, writing can be performed on the writing surface W. The container body 2 is formed from a laminated material 3 having sealant layers 3f on the innermost layer surface of the container using paper as a base material, and the sealant layers are bonded together to form the container body 2. The writing portion 62 is detachably attached to the mouth portion 29 of the container body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a writing instrument that reduces environmental impact by using an ink container made of paper material. [Background technology]

[0002] A writing instrument is provided that contains a liquid such as paint, pigment, or ink inside a container, and supplies the aforementioned liquid to a writing section, for example, made of a porous synthetic resin, attached to the mouth of the container. According to this writing instrument, the writing surface has a relatively large surface area, and by allowing liquid such as ink from the container to seep into the porous writing surface, it is possible to apply or draw on the writing surface (paper, etc.).

[0003] In this type of writing instrument, the line width produced by the writing part is generally thick, and a relatively large amount of ink is consumed. Therefore, as disclosed in Patent Document 1, for example, a relatively large-capacity bottle-type ink container is often used. Accordingly, the ink container used in this writing instrument is molded from a plastic material such as polypropylene (PP) resin or polyethylene terephthalate (PET) resin. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2006-123305 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Incidentally, in recent years, the problem of microplastics flowing into the ocean has attracted attention, and there is growing momentum to address global environmental issues, such as refraining from using disposable plastics. Therefore, attention has also been paid to eliminating plastic from some of the components that make up writing instruments. The applicant has proposed a writing instrument refill that can achieve low pollution by molding the ink reservoir tube, which is housed inside the barrel and has a writing tip attached to its front end, from a composite material including a paper base.

[0006] This invention further develops the above by focusing on a relatively large-capacity ink container that also serves as the grip (barrel) of a writing instrument molded from plastic such as PP resin, and aims to replace it with a material that includes a paper base. This aims to provide writing instruments that contribute to environmental protection through the elimination of plastics. [Means for solving the problem]

[0007] The writing instrument according to this invention, made to solve the aforementioned problems, comprises a container body for containing ink, a writing section positioned at the mouth of the container body, and a detachable cap member covering the writing section, and enables writing on a writing surface by causing the ink in the container body to seep out from the writing section, wherein the container body is formed from a laminated material with paper as the base material and a sealant layer on the innermost layer surface of the container, and the sealant layers are bonded together to form the container body. Furthermore, the container body is formed in a rectangular prism shape, and a writing unit including a writing section and a cap member is attached to the mouth formed on the top surface, and the top surface is a sloping surface that slopes downward from the back side to the front side of the container body, and the writing section is attached in a state that protrudes in a direction perpendicular to the sloping surface. It is characterized by being present.

[0008] Furthermore, it is desirable that the writing section be detachably attached to the mouth of the container body. In this case, preferably, a holder for supporting the writing section is placed at the mouth of the container body, and the writing section is attached to the holder by screwing it in. Furthermore, it is preferable that the writing section comprises a valve seat member which is cylindrical and has a valve opening on its front surface and has male threads on its circumferential surface; a valve body member which is housed within the valve seat member and has a valve body which rises from a ring member and is biased by a plurality of spirally formed spring bodies; a sheet-like writing body which is formed using a foamed sheet material and attached to the front side of the valve body member; and a support ring for the writing body which attaches the peripheral edge of the writing body to the valve seat member. [Effects of the Invention]

[0009] According to the writing instrument of this invention described above, the container body, which has a relatively large volume in which the ink is contained, is formed from a laminated material with paper as the base material, thus contributing to environmental protection by reducing plastic use. In addition, since the container body is constructed by bonding a sealant layer applied to the innermost surface of the laminated material, it is possible to provide an ink storage container that is highly airtight and resistant to breakage.

[0010] Furthermore, a container body molded from a laminated material with paper as the base material can be made more flexible overall compared to containers made from plastic materials such as PP. Therefore, by moderately and repeatedly deforming the container body, an effective stirring action can be applied to the ink inside the container, which contains titanium dioxide and other colorants as mentioned above. [Brief explanation of the drawing]

[0011] [Figure 1] The overall external appearance of the writing instrument according to this invention is shown in (A) a perspective view with the cap member attached to the writing part, (B) a perspective view with the cap member removed, and (C) a perspective view with the writing part further removed. [Figure 2] Figure 1 is a front view showing the process of drawing a line on a horizontal writing surface using the writing instrument shown. [Figure 3] Figure 1 is an unfolded view of the laminated material that forms the body of the writing instrument container. [Figure 4] This is a cross-sectional view showing the layer structure of the laminated material. [Figure 5] The overall configuration of the writing unit is shown, with (A) being an oblique view, (B) a front view, (C) a side view, (D) a top view, and (E) a bottom view. [Figure 6] This is an enlarged cross-sectional view of the writing unit, with (A) being a front cross-sectional view and (B) being a side cross-sectional view. [Figure 7] The individual components of the holder supporting the writing section are shown, with (A) being a perspective view from the top, (B) a perspective view from the bottom, (C) a top view, (D) a front view, (E) a side view, and (F) a front cross-sectional view. [Figure 8] Shows the external configuration of the writing part, (A) is a perspective view, (B) is a front view, (C) is a side view, (D) is a top view, and (E) is a bottom view. [Figure 9] It is also an enlarged cross-sectional view of the writing part, (A) is a front cross-sectional view, and (B) is a side cross-sectional view.

Embodiments for Carrying Out the Invention

[0012] The writing instrument according to this invention will be described based on the embodiments shown in the figures. FIG. 1 and FIG. 2 show the overall configuration of the writing instrument according to this invention. This writing instrument 1 has a container body 2 for accommodating writing ink (not shown), a writing part 62 disposed at a mouth part 29 formed in the container body 2 described later, and a detachable cap member 68 for covering the writing part 62. Thereby, the ink in the container body 2 can be made to exude to the writing body 65 of the writing part 62, and a drawing line can be drawn on the writing surface W.

[0013] The container body 2 is formed of a laminated material 3 having paper as a base material (FIGS. 3 and 4). In the illustrated example, the body part 4 is formed in a prismatic shape, and a writing unit 61 including the writing part 62, the cap member 68, etc. is attached to the mouth part 29 formed on the top surface T. The top surface T is formed as an inclined surface that gradually becomes lower from the back side to the front side of the container body 2, and the writing part 62 is attached in a state of protruding in a direction orthogonal to this inclined surface. Therefore, when the writing part 62 is turned downward as shown in FIG. 2 and the writing part 62 is brought into contact with a horizontal writing surface W, the body part 4 of the container body 2 takes a slightly inclined posture with respect to the vertical direction. Note that the bottom surface B of the container body 2 is formed in a substantially square shape orthogonal to the longitudinal direction of the body part 4, and by placing this bottom surface B on a horizontal plane, the container body 2 of the writing instrument 1 is configured to be stored in a vertically upright state.

[0014] FIG. 3 shows the laminated material 3 forming the container body 2 in a developed state. This laminated material 3 is formed by connecting a front panel 9 in the center, left and right side panels 10 and 11 on either side of the front panel 9, and a pair of rear panels 12 and 13 on either side of the front panel, via vertical fold lines 5, 6, 7 and 8 that form a rectangular cylindrical body 4. In this example, one of the rear panels 12 has an adhesive margin 12a formed along its edge. Furthermore, the container body 2 has top panels 15 and 16 connected to the front panel 9 and rear panels 12 and 13 of the body section, which form the top surface T, via a first top horizontal fold line 14, and side panels 18 and 19 connected to the left and right side panels 10 and 11 of the body section via a second top horizontal fold line 17.

[0015] The system includes first top seal panels 21 and 22 connected to the aforementioned top panels 15 and 16 via a first top seal horizontal fold line 20, and a pair of second top seal panels 24 and 25 connected to a pair of side panels 18 and 19 via a second top seal horizontal fold line 23. A pair of side panels 18 and 19 have inclined lines 26 and 27 formed on them, connecting the midpoint of the second top seal panel horizontal fold line 23 to both ends of the second top horizontal fold line 17, and the second top seal panels 24 and 25 have side top seal vertical fold lines 28 formed on them, hanging down from the upper ends of the second top seal panels 24 and 25 to the midpoint of the second top seal panel horizontal fold line 23.

[0016] Furthermore, the top panel 15, which is connected to the front panel 9 of the body via the first top horizontal fold line 14, has a circular opening 29 into which the writing unit 61 is mounted, formed, for example, by a punching process. Furthermore, in this embodiment, the pair of side panels 18, 19 and the left and right side panels 10, 11 of the body to which the pair of side panels 18, 19 are connected are provided with folding guide lines 30, 31 in the center of the left and right side panels 10, 11 of the body, straddling the second top horizontal fold line 17.

[0017] On the other hand, the container body 2 has bottom panels 35 and 36 connected to the front panel 9 and rear panels 12 and 13 of the body which form the bottom surface B, via a first bottom transverse fold line 34, and side panels 38 and 39 connected to the left and right side panels 10 and 11 of the body via a second bottom transverse fold line 37.

[0018] The system includes first bottom seal panels 41 and 42 connected to the aforementioned bottom panels 35 and 36 via a first bottom seal lateral fold line 40, and a pair of second bottom seal panels 44 and 45 connected to a pair of side panels 38 and 39 via a second bottom seal lateral fold line 43. A pair of side panels 38 and 39 have inclined lines 46 and 47 formed on them, connecting the midpoint of the horizontal fold line 43 of the second bottom seal panel to both ends of the horizontal fold line 37 of the second bottom seal panel, and a vertical fold line 48 of the side top seal is formed on the second bottom seal panels 44 and 45, extending from the lower end of the second bottom seal panels 44 and 45 to the midpoint of the horizontal fold line 43 of the second bottom seal panel.

[0019] Figure 4 shows an example of the layer structure of the laminated material 3 that forms the container body 2 described above. This laminated material 3 has, from the outside to the inside of the container body 2, a first paper substrate layer 3a constituting a first paper substrate, an intermediate layer 3c formed inside the first paper substrate layer 3a and being a metal layer or a silica vapor-deposited layer, and a second paper substrate layer 3e formed inside the intermediate layer 3c and constituting a second paper substrate. Furthermore, it has a layered structure comprising a first adhesive layer 3b that joins the first paper substrate layer 3a and the intermediate layer 3c, and a second adhesive layer 3d that joins the intermediate layer 3c and the second paper substrate layer 3e. Furthermore, a sealant layer 3f made of thermoplastic resin, which is bonded by ultrasonic sealing or the like, is formed on the inside of the second paper substrate layer 3e. In addition, a printed layer 3g is formed on the outside of the first paper substrate layer 3a, on which the product name and logo of the writing instrument 1 are written as needed.

[0020] The same material can be used for the paper substrates constituting the first paper substrate layer 3a and the second paper substrate layer 3e. Various known materials such as fine paper, medium paper, glossy paper, kraft paper, glossy kraft paper, bleached kraft paper, cardboard, white cardboard, liner, lightly coated paper, coated paper, art paper, cast coated paper, glassine paper, parchment paper, and vulcanized fiber can be used. The density of these paper substrates is 0.8 g / cm³. 3 Preferably, the density is 0.8 g / cm³. 3 By using the above-mentioned paper substrate, sufficient water resistance and oil resistance can be provided. The paper substrates constituting the first paper substrate layer 3a and the second paper substrate layer 3e are, in particular, glassine paper, parchment paper, or vulcanized fiber, and have a density of 0.8 g / cm³. 3 It is preferable if the above conditions are met.

[0021] Glassine paper is a high-density, highly transparent paper made by highly beating virgin pulp to increase its specific surface area during papermaking, and then processing the resulting paper with a supercalender to densify it and strengthen the bonds between cellulose fibers. In this invention, the basis weight is 20-50 g / m². 2 Glassine paper is used. By using glassine paper for the first paper base layer 3a and the second paper base layer 3e, it becomes easy to impart water resistance and oil resistance. Also, the basis weight is 20-50 g / m². 2 Glassine paper may be used as the base paper, with a coating solution such as an aqueous polyvinyl alcohol solution applied to one or both sides. The thickness of the glassine paper is usually 20 to 50 μm, preferably 20 to 30 μm.

[0022] Parchment paper and vulcanized fiber are manufactured by treating them with concentrated sulfuric acid or zinc chloride solution during the manufacturing process, thereby strengthening the direct bonds between cellulose fibers; in other words, increasing the density of hydrogen bonds between cellulose fibers. Therefore, by using parchment paper and vulcanized fiber as the paper substrates constituting the first paper substrate layer 3a and the second paper substrate layer 3e, the generation of paper dust can be effectively suppressed.

[0023] For the parchment paper, for example, those with a basis weight of 20 to 100 g / m 2 are used. Preferably, based on the water absorption test method (Cobb method) for paper and paperboard, when mineral oil is used instead of water, the oil absorption is 13 g / m 2 or less, and those with enhanced oil resistance are used. The thickness of the parchment paper is usually 20 to 100 μm, preferably 20 to 60 μm.

[0024] Vulcanized fiber is easier to make thicker than parchment paper due to the difference in reactivity during the manufacturing process. Therefore, it is suitable when thick paper is required as the paper substrate. Considering the ease of handling during manufacturing, the thickness of the vulcanized fiber is usually 0.08 to 1 mm, preferably 0.1 to 0.5 mm. Also, the density of the vulcanized fiber is usually 0.8 to 1.4 g / cm 3 and, considering the ease of obtaining, 0.8 to 1.3 g / cm 3 is preferred.

[0025] In addition, the parchment paper and the vulcanized fiber may be subjected to resin impregnation treatment or glass coating treatment. By performing the above treatment, the bonding between cellulose fibers is further strengthened, and even when these papers are used as the paper substrates constituting the first paper substrate layer 3a and the second paper substrate layer 3e, the generation of paper powder can be suppressed.

[0026] The above-mentioned intermediate layer 3c is a metal layer or a silica vapor deposition layer. The metal layer may be formed by adhering a metal foil such as aluminum foil to one side of the paper substrate with an adhesive containing a polyolefin resin, or by electron beam evaporation of aluminum, or an alloy of aluminum and zinc, etc. under vacuum.

[0027] Next, the adhesives for the first adhesive layer 3b that joins the first paper substrate layer 3a and the intermediate layer 3c, and the second adhesive layer 3d that joins between the intermediate layer 3c and the second paper substrate layer 3e will be described. The adhesive used here may be an adhesive made of one or more types of polyolefin resins, or an adhesive made by mixing the polyolefin resin with other resins.

[0028] Polyolefin resins specifically include polyethylene ionomers, polypropylene ionomers, polypropylene elastomers, polyethylene elastomers, high-density polyethylene, and low-density polyethylene, as well as modified polyolefin resins such as maleic anhydride-modified polypropylene. Of these, polypropylene ionomers and maleic anhydride-modified polypropylene are preferred.

[0029] Other resins include, specifically, acrylic acid copolymers, ethylene-vinyl alcohol copolymers (EVOH), ethylene-acrylic acid copolymers (EAA), ethylene-methacrylic acid copolymers (EMAA), epoxy resins, carbodiimide crosslinking agents, ethylene-vinyl acetate copolymers, or polyvinyl alcohol.

[0030] When mixing polyolefin resin with other resins, the proportion of polyolefin resin in the total amount of adhesive is approximately 60-97% by weight, preferably 90-97% by weight. Furthermore, the proportion of polyolefin resin in the total amount of polyolefin resin and other resins is approximately 68-98% by weight, preferably 93-98% by weight.

[0031] Adhesives containing polyolefin resins are used in the form of dispersion-type or emulsion-type resin liquids, with polyolefin resin or a mixture of polyolefin resin and other resins as the base polymer. Additives such as silane coupling agents may be added to the resin liquid as needed. Of these, dispersion-type adhesives such as polypropylene ionomer and maleic anhydride-modified polypropylene are preferred due to their excellent adhesive properties and handling characteristics.

[0032] By applying an adhesive containing polyolefin resin, which has excellent adhesion and ink resistance to paper materials, the interlayers of the first paper substrate layer 3a, the intermediate layer 3c, and the second paper substrate layer 3e are tightly bonded, preventing ink leakage. Ink resistance refers to the degree to which the elution of the adhesive resin component into the ink can be suppressed. When using an adhesive containing polyolefin resin, the low compatibility with ink prevents the polyolefin resin from dissolving into the ink, thus providing expected benefits in terms of ink resistance.

[0033] On the other hand, for the sealant layer 3f provided inside the second paper substrate layer 3e, thermoplastic resins such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polyvinyl alcohol (PVA) can be suitably used.

[0034] To form the container body 2 using the laminated material 3 shown in Figures 3 and 4, one of the folding guide lines 30 is folded in a mountain fold to fold the outer half of the left side panel 10 of the body and the body rear panel 12 connected thereto toward the rear, and the other folding guide line 31 is folded in a mountain fold to fold the outer half of the right side panel 11 of the body and the body rear panel 13 connected thereto toward the rear. As a result, the adhesive portion 12a of the rear body panel 12 faces the edge of the rear body panel 13. In addition, the first top seal panels 21 and 22 and the second top seal panels 24 and 25 face each other, as do the first bottom seal panels 41 and 42 and the second bottom seal panels 44 and 45.

[0035] By applying, for example, ultrasonic waves to the sealant layer 3e in the aforementioned opposing portions to bond the opposing surfaces together, the laminated material 3 is formed into a bag-like shape with the adhesive allowance 12a on the back and the top and bottom sealed. By folding the inclined lines 26 and 27 that form the top surface T of this bag-shaped laminated body, approximately triangular flaps 32 and 33 are formed on the left and right sides from the side panels 18 and 19, respectively (see Figures 1 and 2). By folding these flaps 32 and 33 onto the left and right side panels 10 and 11 of the cylindrical body 4, a flat top surface T that slopes toward the front can be formed.

[0036] Similarly, by folding the inclined lines 46 and 47 that form the bottom surface B of the bag-shaped laminated body, approximately triangular flaps 49 and 50 are formed on the left and right sides from the side panels 38 and 39, respectively, and the flaps 49 and 50 are folded over the bottom panels 35 and 36, respectively, a flat bottom surface B can be formed. As a result, the vertical fold lines 5, 6, 7, and 8 applied to the laminated material 3 allow for the creation of a container body 2 in which the body 4 is formed into a rectangular prism shape, as shown in Figures 1 and 2. Then, the writing unit 61 is attached to the opening 29 formed on the top surface T of the container body 2 using adhesive or the like, thereby forming the writing instrument 1 shown in Figures 1 and 2.

[0037] Figures 5 and 6 show a writing unit 61 consisting of a holder 67 that supports the writing section 62 and a cap member 68 that covers the writing section 62. The writing unit 61 is mounted with the writing section 62 housed within the holder 67, and the cap member 68 is detachably attached to the holder 67 by screwing it in. The holder 67 is then attached to the mouth portion 29 of the container body 2 along the aforementioned top surface T of the container body 2, thereby forming the writing instrument 1.

[0038] The cap member 68 has a flat closed end face 68b integrally molded from resin material at one end of a short cylindrical portion 68a, and a female thread 68c is formed on the inner circumferential surface of the cylindrical portion 68a, allowing it to be detachably attached to the holder 67 by screwing it in.

[0039] The individual components of the holder 67 are shown in Figure 7. This holder 67 has a flat flange 67a on both sides, with a first cylindrical portion 67b and a second cylindrical portion 67c integrally molded in resin. The outer circumferential surface of the first cylindrical portion 67b is fitted with a male screw 67d. The male thread 67d is screwed into the female thread 68c provided on the inner circumferential surface of the cap member 68, thereby attaching the cap member 68 to the holder 67.

[0040] Furthermore, the inner circumferential surfaces of the first cylindrical portion 67b and the second cylindrical portion 67c are formed coaxially and have the same inner diameter, and an internal thread 67e is formed on this inner circumferential surface. The writing portion 62, which will be described later, is detachably attached to this internal thread 67e by screwing it in. The aforementioned second cylindrical portion 67c is inserted into and positioned in the opening 29 formed on the top surface T of the container body 2, and the flat flange 67a is attached to the top surface T by, for example, an adhesive.

[0041] Figures 8 and 9 show the writing section 62, which consists of a valve seat member 63 that is cylindrical and has a valve opening 63a on its front surface and male threads 63b on its circumferential surface; a valve body member 64 that is housed within the valve seat member 63 and has a valve body 64c that rises from a ring member 64a and is biased by a plurality of spirally formed spring bodies 64b; a sheet-like writing body 65 attached to the front side of the valve body member 64; and a support ring 66 for the writing body 65 that attaches the peripheral edge of the writing body 65 to the valve seat member 63. The ring member 64a, the multiple spring bodies 64b, and the valve body 64c that constitute the valve body member 64 are integrally molded from an elastic resin material.

[0042] The sheet-like cursive writing element 65 is formed using a flexible foamed sheet material. This cursive writing element 65 is made from the foamed sheet material cut into a circular shape, and a spherical protrusion 65a (see Figure 9) is formed in the center to match the shape of the front side of the valve seat member 63. Furthermore, the portion of the cursive writing 65 that forms the spherical protrusion 65a in the center retains the same thickness as the aforementioned foamed sheet material, while its peripheral portion is formed, for example, by press working, so that it becomes thinner than the spherical protrusion 65a.

[0043] The support ring 66 for the cursive writing instrument 65 supports the surface-shaped cursive writing instrument 65 along its periphery by pressing the peripheral edge of the cursive writing instrument 65, which is mounted on the front surface of the valve seat member 63, along the front peripheral edge of the valve seat member 63. This support ring 66 is molded from a resin material and attached by welding it along the circumferential surface on the front side of the valve seat member 63.

[0044] The writing section 62 is provided with a male thread 63b on the circumferential surface of a cylindrical valve seat member 63, and is detachably attached to a female thread 67e on the inner circumferential surface of the holder 67 using this male thread 63b. Therefore, if the writing tip 65 of the writing section 62 wears out, it can be replaced, and the container body 2 can be reused by removing the writing section 62 and filling it with ink.

[0045] A preferred writing ink to be contained in the container body 2 comprises a pigment, a surfactant having an acetylene bond, a β-propiolactone compound, and a solvent, wherein the surfactant having an acetylene bond has an HLB value of 6 to 15, and the β-propiolactone compound contains an alkyl ketene dimer made from a fatty acid having 14 to 20 carbon atoms.

[0046] In embodiments, the colorant can be arbitrarily selected from conventionally known pigments and dyes. Examples of pigments include inorganic pigments such as metal oxides or metal salts, organic pigments such as organic dye pigments or lake pigments, and glossy pigments such as aluminum pigments. Examples of dyes include acid dyes, basic dyes, direct dyes, reactive dyes, vat dyes, sulfide dyes, metal-containing dyes, cationic dyes, and disperse dyes. Among these, titanium dioxide is particularly preferred because it can be combined with complementary pigments, as described later, to achieve a wide range of colors. In the writing ink of the embodiment, the pigment is preferably surface-treated with a coating material. Preferred materials for the coating material include inorganic oxides such as silica, alumina, zirconia, and zinc oxide, metals such as molybdenum, and phosphates. This is because surface-treating the pigment with the coating material suppresses aggregation of pigments in the ink, stabilizing the dispersion of the pigment, and also suppresses the reaction between the pigment and water, thereby reducing the generation of bubbles. Furthermore, when a pigment containing metal is subjected to shear force from a mixer or the like during ink manufacturing, the deformation and damage of the pigment and the elution of metal ions are suppressed, thus improving the long-term stability of the ink. Considering the dispersion stability in the ink as described above, the coating material for the pigment is more preferably an inorganic oxide containing silica or alumina. Regarding the pigment, the amount of coating material applied to the surface-treated pigment is preferably 0.01% to 20% by mass, relative to 100 parts by mass of pigment after surface treatment. If the coating amount is within the above numerical range, ink dispersion and metal elution can be easily suppressed.

[0047] In the embodiments, when using pigments surface-treated with inorganic oxides, considering dispersion stability in the ink, it is preferable that the pigments surface-treated with inorganic oxides have a positive or negative surface charge in the ink. In particular, when using pigments treated with silica-containing inorganic oxides, it is preferable that they have a negative surface charge, and when using pigments treated with alumina-containing inorganic oxides, it is preferable that they have a positive surface charge. Such pigments exhibit good dispersibility in the composition, but their dispersibility and redispersibility can be further enhanced by combining them with pigment dispersants described later. When the surface-treated pigment has the above surface charge, considering dispersion stability in the ink, it is preferable that the surface-treated pigment is titanium dioxide. The average particle size of the pigment is preferably 0.01 μm to 30 μm on a volume basis. If the average particle size of the pigment is within the above numerical range, even when writing on a writing surface with large gaps between fibers, such as paper or cloth, the pigment is less likely to penetrate the gaps between the fibers, making it easier to obtain vivid color development. Furthermore, when using an ink containing a pigment with an average particle size within the above numerical range in a writing instrument such as a marker, the ink ejection performance can be improved. In this specification, the average particle size 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. The pigment content in the ink is preferably 1% to 40% by mass, based on the total mass of the ink. If the pigment content is within the above numerical range, a decrease in ink ejection performance can be prevented, and the clarity and opacity of the ink and the writing formed using it can be maintained.

[0048] The writing ink of the embodiment preferably contains a pigment dispersant. By combining a pigment dispersant with a pigment, it is possible to suppress the aggregation of pigments and improve the stability of the ink. The pigment dispersant used in the embodiment is not particularly limited as long as it has the effect of improving the dispersibility of the pigment, but when using a pigment surface-treated with an inorganic oxide, it is preferable to use a pigment dispersant having anionic or cationic adsorbent groups, considering the dispersion stability of the pigment. When using a pigment surface-treated with an inorganic oxide containing silica in the composition of the embodiment, it is preferable that the pigment dispersant has cationic adsorbent groups. Considering the stability and safety of the ink composition, it is preferable that the acid-base balance is near neutral, but at this pH, the pigment in the ink composition has a negative surface charge, so cationic adsorbent groups can easily adsorb to the pigment by electrical attraction, making dispersion easier. One or more types of pigment dispersants can be used. Furthermore, when using a pigment surface-treated with an inorganic oxide containing alumina in the composition, it is preferable that the pigment dispersant has anionic adsorbent groups. In the aforementioned acid-base conditions, the pigment has a positive surface charge, so anionic adsorption groups readily adsorb to the pigment by electrical attraction, facilitating dispersion. In the embodiment, the content of the pigment dispersant is preferably 0.01% to 5% by mass, calculated on a solid content basis of the active ingredient. Furthermore, if A is the total content of the colorant relative to the total amount of the ink composition, and B is the total content of the pigment dispersant relative to the total amount of the ink composition, then B / A is preferably 0.005 ≤ B / A ≤ 0.5. When the content of the pigment dispersant and the ratio of the pigment dispersant content to the colorant content are within the above numerical range, the dispersibility of the pigment is good, and it is possible to suppress the viscosity of the ink composition from becoming excessively high.

[0049] The writing ink of the embodiment comprises a penetrating agent. The penetrating agent is preferably a surfactant having an HLB value of 4 to 18, considering its wettability improvement effect and solubility in the ink composition. Here, the HLB value of the surfactant is a value used by Griffin to evaluate the hydrophilicity of a compound, and is calculated by the following formula (1). The HLB value obtained by the Griffin method is in the range of 0 to 20, with a higher value indicating greater hydrophilicity of the compound. HLB value = 20 × (mass of hydrophilic groups %) = 20 × (sum of formula weights of hydrophilic groups / molecular weight of surfactant) ... (1) As a penetrating agent, it is preferable to select and use one or more from surfactants having an acetylene bond in their structure, fluorine-based surfactants, silicone-based surfactants, and succinic acid-based surfactants. By incorporating such surfactants into the ink, the surface tension is lowered, improving the wettability of the ink to impermeable recording media such as films, and improving writing performance by reducing streaking and gaps in the writing on the impermeable recording media. Among the penetrating agents, surfactants having an acetylene bond are highly stable and can sustainably exhibit the effect of improving wettability, improving writing performance by reducing streaking and gaps in the writing on the impermeable recording media. A preferred penetrating agent is an acetylene glycol-based surfactant, which is excellent at suppressing bubble generation and easily suppresses foaming of the writing during writing, resulting in a smooth writing surface. Furthermore, the content of the surfactant having an acetylene bond is preferably 0.001% to 1.5% by mass. When the content is within the above numerical range, it is possible to achieve both suppression of foaming of the writing and improvement of wettability.

[0050] The ink according to the embodiment preferably contains a β-propiolactone compound. The β-propiolactone compound in the embodiment is a compound having a β-propiolactone ring, and in the ink composition, it adsorbs with colorant particles, polyolefin particles (described later), and complementary pigments, forming bulky aggregates of colorant. When writing on a writing surface such as paper or cloth, which has large gaps between its fibers, the colorant does not penetrate into the writing surface through the gaps between the fibers, and the colorant adheres more easily to the fibers on the surface of the writing surface, resulting in good color development of the writing. Furthermore, when writing on a non-penetrating surface, it adsorbs to the writing surface, improving the fixation of the writing. In addition, since the β-propiolactone compound has an anti-slip effect, when writing on writing formed by the composition, even if lubricating substances such as hand grease are attached to the writing surface, the ink dispensing part of the writing surface is prevented from slipping. Thus, the β-propiolactone compound also has the effect of preventing interruptions in the writing during writing. In this embodiment, by using the penetrating agent and a β-propiolactone compound in combination, it is possible to create a writing instrument ink composition that not only improves the writing properties on the non-penetrating recording medium but also improves the fixation of the writing marks. At the same time, it also exhibits excellent color development and high fixation of writing marks even on writing materials with large gaps between fibers, such as paper and cloth, and allows for good writing on both non-penetrating and penetrating surfaces. In this embodiment, the β-propiolactone compound is not particularly limited as long as it exhibits the above effects, but it is preferably an alkyl ketene dimer composed of a fatty acid having 10 to 24 carbon atoms. When the number of carbon atoms of the fatty acid is within the above numerical range, the β-propiolactone compound is more likely to adsorb with the coloring agent and form bulky aggregates, and can be stably dispersed in the ink composition. Furthermore, considering stable dispersion, it is more preferable that it be an alkyl ketene dimer composed of a fatty acid having 14 to 20 carbon atoms. Furthermore, alkyl ketene dimers may be composed of multiple types of fatty acids with different numbers of carbon atoms, as long as the number of carbon atoms of the constituent fatty acids meets the above range.The β-propiolactone compound used in the embodiment is preferably an alkyl ketene dimer containing a C18 fatty acid as a constituent raw material, considering the formation and dispersibility of bulky aggregates. Furthermore, such an alkyl ketene dimer preferably has an average particle size of 0.1 μm to 2.0 μm. If the average particle size is within this range, the alkyl ketene dimer readily forms bulky aggregates with colorants and other materials, and readily exhibits good ink discharge properties. The above alkyl ketene dimer is preferably used as an emulsion, which allows for the maintenance of high stability over time. The content of the β-propiolactone compound is preferably 0.1% to 4% by mass relative to the total amount of the ink composition. If the content is within the above range, it is possible to prevent the ink viscosity from becoming too high and to prevent a decrease in ink discharge properties when writing. When the sum of the total content of the colorant relative to the total amount of the ink composition and the total content of the complementary pigment (described later) relative to the total amount of the ink composition is A, and the total content of the β-propiolactone compound relative to the total amount of the ink composition is B, it is preferable that the range is 0.005 ≤ B / A ≤ 0.5. This is because, within the above numerical range, the colorant adheres more easily to the surface of the writing surface, resulting in good color development, and the viscosity of the ink composition does not become too high, resulting in good ink discharge and excellent writing performance.

[0051] The ink according to the embodiment preferably contains a poorly water-soluble resin. A poorly water-soluble resin is a resin whose solubility in water (amount of solute per 100g of water) is less than 1.0g. In the ink composition, it binds to the bulky aggregates, colorants, and polyolefin particles described later, and adheres to the writing surface during writing, thereby improving the fixation and abrasion resistance of the writing and improving the color development of the writing. Therefore, in the writing ink of the embodiment, it is preferable to use both a β-propiolactone compound and a poorly water-soluble resin in combination, as this further improves the fixation and color development of the writing. In the embodiment, the poorly water-soluble resin is preferably used as an emulsion or dispersion, which allows the poorly water-soluble resin to maintain a stable dispersion state. Considering the improvement of the color development, fixation, and abrasion resistance of the writing, it is more preferable that the composition of the embodiment contains one or more selected from polyolefin resins, acrylic resins, nylon resins, and polyester resins. By including a polyolefin resin or acrylic resin, it is possible to achieve both good color development and high ink retention and abrasion resistance. These effects are effectively manifested by using a β-propiolactone compound in combination with the above-mentioned poorly water-soluble resin. Considering the color development and retention of the ink, a copolymer of ethylene and acrylic acid is more preferable as the polyolefin resin used in the ink composition, and a self-emulsifying copolymer of ethylene and acrylic acid is particularly preferable. The acrylic resin used in the embodiments is a polymer containing acrylic acid or methacrylic acid in its repeating units, and it is possible to use one or more types of acrylic resins. To further improve ink retention and abrasion resistance, acrylic styrene resin is preferred, and a self-crosslinking acrylic styrene copolymer is even more preferred. The molecular weight of the above-mentioned acrylic resin is not particularly limited, but generally, a mass-average molecular weight of 1,000 to 1,000,000 is used. Furthermore, the nylon resin and polyester resin used in the embodiments are not particularly limited as long as they have the effect of improving the color development, ink fixation, and abrasion resistance of the ink composition.The content of the poorly water-soluble resin is preferably 0.1% to 10% by mass relative to the total amount of the ink composition. Furthermore, if the total content of the β-propiolactone compound relative to the total amount of the ink composition is A, and the total content of the poorly water-soluble resin relative to the total amount of the ink composition is B, then it is preferable that the range is 0.1 ≤ B / A ≤ 5. This is because if the content of the poorly water-soluble resin and the ratio of the content of the poorly water-soluble resin to the content of the β-propiolactone compound are within the above numerical range, the adhesion of the colorant to the writing surface will be improved, and it will be easier to achieve excellent writing properties.

[0052] Suitable solvents include water and mixed solvents of water and organic solvents. Conventional waters such as deionized water, distilled water, and tap water can be used as the water. When using a mixed solvent of water and organic solvent, ethanol, n-propanol, isopropanol, etc., can be used as the organic solvent. Diols or triols with relatively high boiling points, such as glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and polyethylene glycol, can be used, but their concentration should be small. The organic solvent content is preferably 1% to 30% by mass relative to the total mass of the solvent. If the organic solvent content is within the above range relative to the total mass of the solvent, good drying performance and ink drying properties can be achieved. The solvent content in the ink is preferably 20% to 90% by mass, based on the total mass of the composition. Within this numerical range, the solvent content allows for stable dissolution or dispersion of each component, and enables the formation of bulky aggregates in the ink that are easily redispersible.

[0053] Furthermore, the writing ink composition of the embodiment can be given high fixability and abrasion resistance to the handwriting by using polyolefin resin particles. Polyolefin resin particles are fine particles with surface lubricity, consisting of polyolefins such as polyethylene and polypropylene, and mixtures thereof, which suppress excessive force being applied to the handwriting when the handwriting is subjected to external forces such as abrasion, and are a different type of polyolefin resin from the poorly water-soluble resins mentioned above. The molecular weight of these polyolefins is not particularly limited, but for example, polyolefins with a mass-average molecular weight of 500 to 100,000 are preferred. If the mass-average molecular weight of the polyolefin resin particles is within the above numerical range, when this ink is used with a writing instrument such as a marker to write, it is possible to give the formed handwriting higher lubricity and consequently higher abrasion resistance, resulting in good handwriting. The polyolefin resin particles may contain materials other than polyolefin as needed. Therefore, using the aforementioned poorly water-soluble resin and polyolefin resin in combination is preferable because it is easier to improve the color development, fixation, and abrasion resistance of the handwriting, and in particular, it is easy to write well even when writing on an impermeable recording medium. The shape of the polyolefin resin particles is not particularly limited and can take any shape such as irregular, spherical, needle-shaped, plate-shaped, or square. The average particle diameter of the polyolefin resin particles is preferably 0.1 μm to 35 μm. If the average particle diameter of the polyolefin resin particles is within the above numerical range, when this ink is used with a writing instrument such as a marker to write, it is possible to impart higher lubricity and, consequently, higher abrasion resistance to the formed writing line, and good handwriting can be obtained. Furthermore, from the viewpoint of imparting high abrasion resistance, it is more preferable that it be 0.1 μm to 25 μm. The average particle diameter of the polyolefin resin particles can be measured by the Coulter counter method. The content of polyolefin resin particles in the ink is preferably 0.01% to 10% by mass, based on the total mass of the ink. If the content of polyolefin resin particles is within the above numerical range, ink ejection performance can be maintained, and higher lubricity can be imparted to the writing line.

[0054] The ink according to the embodiment may contain complementary pigments to adjust the color of the resulting writing line. In particular, when white titanium dioxide is selected as the main pigment particles, various colors can be achieved by combining it with complementary pigments. The complementary pigment is not particularly limited, and various pigments of different colors such as red, blue, yellow, green, white, and black can be used, and it is also possible to use a pigment dispersion obtained by dispersing the pigment in a solvent. The content of the complementary pigment in the ink is preferably 0.01% to 15% by mass, based on the total mass of the ink.

[0055] Furthermore, the ink may contain, as necessary, binders, preservatives, defoamers, rust inhibitors, pH adjusters, bubble inhibitors, bubble absorbers, shear viscosity reducers, and viscosity modifiers.

[0056] The viscosity of the ink according to the embodiment is preferably low. The viscosity of the composition can be measured using an E-type rotational viscometer (manufactured by Brookfield). Specifically, the viscosity of the ink at 20°C is preferably 1 to 100 mPa·s when measured at a rotation speed of 100 rpm (shear rate 380 sec-1). Furthermore, when measured at a rotation speed of 10 rpm (shear rate 38 sec-1), it is preferably 1 to 600 mPa·s. At a rotation speed of 1 rpm (shear rate 3.8 sec-1), it is preferably 1 to 3000 mPa·s. If the viscosity of the ink is within the above numerical range, the ink ejection performance can be improved, and the writing performance on non-permeable recording media such as films can be improved. The surface tension of the ink is preferably 10 to 35 mN / m at a 20°C environment. If the surface tension is within this range, it tends to prevent ink bleeding and show-through on the paper, improves the wettability of the ink, and reduces streaking and gaps in the writing on the non-permeable recording medium, thereby improving writing performance. In particular, surfactants having an acetylene bond in their structure are suitable for adjusting the surface tension of the ink. The surface tension is determined at a 20°C environment using a surface tension meter manufactured by Kyowa Interface Science Co., Ltd., with a platinum plate and measured by the vertical plate method. The pH of the ink is preferably 6 to 10. If the pH of the ink is within this range, it is possible to suppress discoloration of the ink composition and excessive viscosity. Furthermore, when using a pigment treated with an inorganic oxide containing silica or alumina in the ink composition, the dispersibility of the pigment can be further improved by using the aforementioned pigment dispersant. In the embodiment, the pH value can be measured at 20°C using, for example, an IM-40S pH meter (manufactured by Toa DKK Co., Ltd.). The ink according to the embodiment can be manufactured by any conventionally known method. Specifically, the required amounts of each component are blended and mixed using various stirrers such as propeller stirring, homodispersing, or homomixing machines, or various dispersers such as bead mills.

[0057] Furthermore, by eliminating the need for a stirring ball contained within the ink container to redisperse the conventional colorants, it is possible to provide a writing instrument that reduces manufacturing costs and facilitates container recycling.

[0058] In this embodiment, the writing section 62 of the writing instrument 1 is equipped with an internal stopper (valve valve) consisting of a valve opening 63a of a valve seat member 63 and a valve body 64c of a valve body member 64. Therefore, as shown in Figure 2, by pressing the writing tip 65 of the writing section 62 against the writing surface W, the valve member 64c can be retracted against the biasing force of the spring body 64b via the writing tip 65. As a result, the seal of the valve body 64c against the valve opening 63a is released, and the ink in the container body 2 is supplied to the writing tip 65 and absorbed. Then, ink seeps from the cursive writing instrument 65 toward the spherical protrusion 65a, thereby writing on the writing surface W.

[0059] In the above-described embodiment, the writing section 62 attached to the mouth 29 of the container body 2 is equipped with an inner stopper (valve valve) including a valve opening 63a and a valve body 64c. However, the writing instrument 1 according to this invention does not necessarily require the inner stopper, and can also be used in a direct-ink type writing instrument in which the ink in the container body 2 directly permeates the writing section 65. [Explanation of symbols]

[0060] 1 writing implements 2. Container body 3 Laminated material 3a 1st paper base layer 3b 1st adhesive layer 3c middle class 3d second adhesive layer 3e 2nd paper base layer 3f sealant layer 3g printing layer 4 Torso 29 Mouth 61 writing units 62 Writing section 65 Cursive 67 Holder 68 Cap component T Top surface B Bottom W writing surface

Claims

[Claim 1] A writing instrument comprising a container body for holding ink, a writing section positioned at the mouth of the container body, and a removable cap member covering the writing section, wherein writing is made possible on a writing surface by causing the ink in the container body to seep out from the writing section, The container body is formed from a laminated material with paper as the base material and a sealant layer on the innermost surface of the container, and the sealant layer is bonded to form the container body. The container body has a rectangular prism-shaped body, and a writing unit including a writing section and a cap member is attached to the opening formed on the top surface. The top surface is sloped downward from the back to the front of the container body, and the writing section is attached in a position where it protrudes in a direction perpendicular to the sloped surface. The writing section is detachably attached to the mouth of the container body, a holder for supporting the writing section is positioned at the mouth of the container body, and the writing section is attached to the holder by screwing it in, The writing instrument is characterized by comprising: a valve seat member which is cylindrical in shape and has a valve opening on its front surface and has male threads on its circumferential surface; a valve body member which is housed within the valve seat member and has a valve body which rises from a ring member and is biased by a plurality of spirally formed spring bodies; a sheet-like writing body which is formed using a foamed sheet material and attached to the front side of the valve body member; and a support ring for the writing body which attaches the peripheral edge of the writing body to the valve seat member.

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