Fiber bundle body for liquid cosmetics or liquid medicines, and application part and applicator using the same

Abstract

To provide a fiber bundle body for liquid cosmetics or liquid medicines with excellent strength and durability, being suitably usable as an ink guide core for an application part or as an application pen core, etc, and applicator using the fiber bundle body.SOLUTION: A fiber bundle body for liquid cosmetics or liquid medicines used for an ink guide core to an application part or an application pen core, the fiber bundle body for liquid cosmetics or liquid medicines is characterized in that the fiber bundle body for liquid cosmetics or liquid medicines is composed of multifilaments of long fibers having fibers with different melting points, and the multifilaments contain at least crimped fibers.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present specification relates to a fiber bundle for a liquid cosmetic or liquid medicine, which has excellent strength and durability and can be suitably used as an ink guide core for an application part, or an application pen core, etc., and to an application part and an applicator using the same. [Background technology]

[0002] 2. Description of the Related Art A wide variety of structures have been known for writing instruments in which fiber bundles made of synthetic resin fibers, natural fibers, or the like are used as pen tips, intermediate cores, or the like, and for applicators used as applicators for cosmetics, etc. The fiber bundles used in these writing instruments and cosmetic tools are used as ink supply cores such as pen cores and relay cores, and liquid supply cores for applicators and the like.

[0003] Among these fiber bundles, binderless fiber bundles (which do not use thermosetting resin for adhesion) are known as ones that can easily adjust hardness and porosity and can meet a wide range of required qualities. An example of this binderless fiber bundle is a fiber liquid supply core that is formed by mixing two or more types of fibers, including a main fiber and a heat-fused fiber having a low-melting point portion with a lower melting point than the main fiber on at least a part or all of the outer surface, aligning them in the longitudinal direction, bundling them, and compressing them, and is characterized in that the fibers are bound by the low-melting point portions when the fibers are heat-fused in a state in which there are continuous pores between the fibers, and are formed into a solid rod shape with the fibers oriented in the longitudinal direction (see, for example, Patent Document 1).

[0004] The technology described in Patent Document 1 uses two or more types of fibers, one of which is a low-melting point fiber. However, there is an issue with dimensional stability due to thermal shrinkage of the low-melting point fiber, making it difficult to produce the product using only multifilaments of composite long fibers such as a core-sheath type. In order to stably fix the low-melting point fiber, it was necessary to manufacture the product by mixing two or more types of short fibers with different melting points (fiber lengths that are not approximately the same as the length of the pen core or the like to be molded, but are formed short for thermal welding). However, in the case of fiber bundles using short fibers, when pen cores, relay cores, liquid supply cores, etc. are made to have a slender cross section, for example, when forming cores with a rectangular or irregular cross section, particularly when forming fiber bundle cores with a small diameter, it is necessary to reduce the amount of bundled short fibers. In this case, tension is applied to the front and rear in the longitudinal direction when drawing out the yarn bundle, which may cause the entanglement of the short fibers to become misaligned. This causes problems such as variations in the yarn density in the longitudinal direction of the core, or, in the worst case, the entanglement of the short fibers is weakened, causing the yarn bundle to separate from the front and rear. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2011-20443 A (Claims, Examples, etc.) Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure is made in consideration of the problems and the like of the conventional technology and seeks to solve these problems, and aims to provide a fiber bundle for a writing instrument used as a pen core, relay core, liquid supply core, etc., which has no variation in thread density in the longitudinal direction of the core, and has excellent strength and durability, without compromising the liquid supply performance of the fiber bundle, even when the fiber bundle core has a rectangular or irregular cross section, especially when it has a small diameter. It also aims to provide a pen tip and a writing instrument using the same. [Means for solving the problem]

[0007] The inventors have attempted to solve the above-mentioned problems in the conventional art by discovering that a fiber bundle for a writing instrument used as an ink guide core for a pen tip or as a writing pen core is composed of a multifilament of long fibers having fibers with different melting points, and that the multifilament contains at least fibers with specific physical properties, thereby obtaining the above-mentioned fiber bundle for a writing instrument, and a pen tip and writing instrument using the same, and have thus completed the present disclosure.

[0008] In other words, the fiber bundle for a writing instrument disclosed herein is a fiber bundle for a writing instrument used as an ink guide core for a pen tip or as a writing pen core, and is characterized in that the fiber bundle for a writing instrument is composed of a multifilament of long fibers having fibers with different melting points, and that the multifilament contains at least crimped fibers. The crimped fiber preferably has a crimp ratio calculated by the following formula (I) of 1 to 50%. Crimp ratio = (crimp width ÷ crimp length) × 100 …… (I) (In the above formula (I), the distance from the peak to the peak of the wavy shape of the fiber is defined as the "crimp length", and the distance between the peak (crest) and the bottom (trough) of the wave in the direction perpendicular to the crimp length is defined as the "crimp width".) However, the crimp shape is not limited to a wave shape, and may also include a loop shape as shown in FIG. 1(d). The content of the crimped fibers is preferably 10 to 100% by mass based on the total amount of the fiber bundle for a writing instrument. These fiber bundles for writing instruments preferably have a rectangular cross-sectional shape. The pen tip of the present disclosure is a pen tip having a writing pen core, characterized in that the writing pen core is made from a fiber bundle for a writing instrument of the above-mentioned configuration, and is also a pen tip having an ink guide core that guides ink to the writing portion, characterized in that the ink guide core is made from a fiber bundle for a writing instrument of the above-mentioned configuration. The writing instrument of the present disclosure is characterized by having a pen tip having a writing pen core of the above-mentioned configuration, and / or a pen tip having an ink guide core that guides ink to the writing portion of the above-mentioned configuration. In this disclosure, the term "crimped fiber" refers to a fiber that is given bulkiness and stretchability by imparting two-dimensional or three-dimensional crimp and strain to the fiber, fixing the strain by an appropriate method, and disrupting the parallelism between the fibers. As described above, in this disclosure, the preferred crimped fiber is one that has a crimp ratio calculated by the above formula (I) within the above range. Effect of the Invention

[0009] According to the present disclosure, there is provided a fiber bundle for a writing instrument, which has excellent strength and durability, no variation in thread density in the longitudinal direction of the core, and no loss in the liquid supply performance of the fiber bundle, even in the case of a fiber bundle core with a rectangular or irregular cross-section, especially a small diameter, and a pen tip and a writing instrument using the same. The objects and advantages of the disclosure will be realized and obtained by means of the elements and combinations particularly pointed out in the claims. Both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the disclosure as claimed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1(a) is a schematic oblique view showing an example of an embodiment of a fiber bundle for a writing instrument of the present disclosure; FIG. 1(b) is an explanatory diagram explaining the crimp rate of the crimped fiber in the fiber bundle for a writing instrument of the present disclosure; FIG. 1(c) is an electron microscope (SEM) photograph showing an example of having crimped fiber in a fiber bundle for a writing instrument; and FIG. 1(d) is an electron microscope (SEM) photograph showing an example of a case where the crimp shape of the crimped fiber in the fiber bundle for a writing instrument of the present disclosure is not limited to a wavy shape but includes a loop shape. [Diagram 2]1A and 1B are schematic diagrams showing cross-sectional views to explain the shape of multifilaments having different melting points used in the fiber bundle for a writing instrument of the present disclosure, where (a) shows a side-by-side type and (b) shows a core-sheath type. [Diagram 3] FIG. 2 is a schematic perspective view showing another embodiment of a fiber bundle for a writing instrument according to the present disclosure. [Figure 4] 1 is a schematic diagram showing, in cross-section, an example of an embodiment of a manufacturing process for producing a fiber bundle for a writing instrument according to the present disclosure. FIG. [Diagram 5] 1A is an end view of an example (embodiment) of a fiber bundle for a writing instrument of the present disclosure, and a scanning electron microscope (SEM) photograph of its enlarged view; FIG. 1B is an end view of an example (embodiment) of a fiber bundle for a writing instrument of the present disclosure, and a scanning electron microscope (SEM) photograph of its enlarged view; FIG. [Figure 6] FIG. 1 shows an example of a writing instrument of the present disclosure, which is an embodiment of a twin-type writing instrument having pen tips on both ends, where (a) is a front view and (b) is a vertical cross-sectional view as viewed from the front. [Figure 7] 7A, 7B, and 7C are diagrams showing the writing implement of FIG. 6 with caps at both ends removed, where (a) is a plan view, (b) is a front view, and (c) is a vertical cross-sectional view as seen from the front. [Figure 8] 7 is an enlarged perspective view showing half of the twin-type writing instrument of FIG. 6, including a pen tip having one of the writing pen cores. FIG. [Figure 9] 9A and 9B are drawings showing an example of an embodiment of a holder for holding the writing pen core of the pen tip of FIG. 8, in which (a) is a perspective view from the front side, (b) is a plan view, (c) is a perspective view from the rear side, (d) is a right side view, (e) is a front view, (f) is a left side view, (g) is a vertical cross-sectional view as seen from the front, and (h) is a bottom view. [Figure 10] 7 is an enlarged perspective view showing one half of the twin-type writing instrument of FIG. 6, including the pen tip having the other ink supply core. FIG. [Figure 11]11A and 11B are drawings showing an example of an embodiment of a holder for holding the ink supply core and writing part of the pen tip in FIG. 10, in which (a) is a perspective view from the front, (b) is a plan view, (c) is a perspective view from the rear, (d) is a right side view, (e) is a front view, (f) is a left side view, (g) is a vertical cross-sectional view as seen from the front, and (h) is a bottom view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. However, it should be noted that the technical scope of the present disclosure is not limited to the embodiments described below, but covers the inventions described in the claims and their equivalents.

[0012] The fiber bundle for a writing instrument of the present disclosure is characterized in that it is composed of a multifilament of long fibers having fibers with different melting points (in the present disclosure, the melting point includes a case where the bundle has no melting point but a softening point), and the multifilament contains at least crimped fibers. Fig. 1(a) is a schematic perspective view showing an example of an embodiment of a fiber bundle for a writing instrument having a rectangular cross-sectional shape.

[0013] Fibers generally come in filament (monofilament, multifilament) and sliver forms, and monofilament or multifilament are used to obtain a fiber bundle with uniform density in the longitudinal direction. In the present disclosure, however, the fiber bundle for a writing instrument is formed from a multifilament of long fibers having fibers with different melting points, and some of the multifilament long fibers contain crimped fibers.

[0014] In the present disclosure, examples of multifilaments having different melting points include those composed of a combination of two or more polymers having different chemical structures, such as polyester, acrylic, polypropylene, wholly aromatic polyester, wholly aromatic polyesteramide, polyamide, semi-aromatic polyamide, wholly aromatic polyamide, wholly aromatic polyether, wholly aromatic polycarbonate, polyimide, polyamideimide (PAI), polyether ether ketone (PEEK), polyphenylene sulfide (PPS), poly-p-phenylene benzobisoxazole (PBO), polybenzimidazole (PBI), polytetrafluoroethylene (PTFE), and ethylene-vinyl alcohol copolymers. In addition, those having at least a common chemical structure in part but having different melting points due to the introduction of other structural units to form a copolymer, such as a combination of polyethylene terephthalate and a copolymerized polyethylene terephthalate copolymer having a lower melting point, can be preferably mentioned.

[0015] For example, as shown in Figures 2(a) and (b), it is possible to use either a sheath-core type having a low melting point fiber and a high melting point fiber, or a side-by-side type. The sheath-core type is a multifilament in which a single yarn is composed of a core component and a sheath component, and the side-by-side type is a multifilament in which a single yarn is composed of two or more polymers in a side-by-side type. Among these, the sheath-core type multifilament is preferable, and it is more preferable that the sheath component of the sheath-core type is a component with a lower melting point than the core component. In the present disclosure, the melting point difference (high melting point temperature - low melting point temperature) is at least 30 ° C, preferably 50 ° C or more. When the melting point difference is 30 ° C or more, only the sheath part of the core-sheath type multifilament is thermally melted, and the intertwining points between the fibers that have been disrupted in parallelism by the crimping process are point-bonded to form a three-dimensional network structure, which makes it easy to solidify them together. There is no upper limit to the melting point difference as long as the fibers can be subjected to crimping and are heat-fusible composite fibers that are available on the market, but 100 ° C is realistic. In the present disclosure, the melting point is a value measured in accordance with JIS K 7121:2012.

[0016] In the present disclosure, the multifilament of long fibers having fibers with different melting points includes at least crimped fibers. The crimped fibers used are fibers that are obtained by imparting two-dimensional or three-dimensional crimp / strain to the multifilament of long fibers having fibers with different melting points, fixing the strain by an appropriate method, and disrupting the parallelism between the fibers, thereby imparting bulkiness and stretchability. The crimped fibers used in the present disclosure preferably have a crimp (crimp) ratio of 1 to 50%, more preferably 1 to 20%, as shown in the following formula (I) and FIG. 1(b), from the standpoints of adhesion and solidification, which form a three-dimensional network structure by point-bonding the intertwining points between fibers, and the formation of a fiber bundle core with high porosity achieved by the entanglement of highly bulky fibers. Crimp ratio = (crimp width ÷ crimp length) × 100 …… (I) (In the above formula (I), the distance from the peak to the peak of the wavy shape of the fiber is defined as the "crimp length", and the distance between the peak (crest) and the bottom (trough) of the wave in the direction perpendicular to the crimp length is defined as the "crimp width".) In the crimped fibers in the fiber bundle for a writing instrument of the present disclosure, the crimp shape is not limited to a wavy shape, and when a loop shape is included as shown in FIG. 1(d), the crimp ratio can be calculated as the distance from the apex of the loop to the bottom point (valley) of the fiber, which is the "crimp width", in the same manner as for wavy fibers.

[0017] By setting the crimp ratio at 1% or more, the intertwining points between the fibers can be point-bonded to form a three-dimensional mesh structure, which can then be solidified to form a fiber bundle core with high porosity due to the entanglement of the fibers with high bulkiness. On the other hand, by setting the crimp ratio at 50% or less, the parallelism between the fibers is not lost, and a flow path that is optimal for ink outflow can be formed. From the above viewpoints, the content of the crimped fibers is preferably 10 to 100% by mass based on the total amount of the fiber bundle for a writing instrument.

[0018] The fineness of each of the multifilament of long fibers having fibers with different melting points and the crimped fibers is preferably 1 to 20 denier or less in terms of ink retention and writing feel when used as a pen tip.

[0019] The fiber bundle for a writing instrument of the present disclosure is formed by aligning and bundling the long fiber multifilament having the above-mentioned fibers with different melting points and the crimped fiber having the above-mentioned configuration in the above-mentioned predetermined ratio, heating the fiber bundle, and solidifying the fibers by heating and pressing without using short fibers or a solvent that serves as a binder resin, i.e., forming a fiber bundle in which the fibers are solidified and bound together. For example, as shown in Fig. 4, a thermoforming machine 10 is arranged with the long fiber multifilament having the above-mentioned fibers with different melting points and the crimped fiber having the above-mentioned configuration aligned in the longitudinal direction in the above-mentioned predetermined ratio while pulling them with a pulling roller 11 arranged in the front, bundling them, and solidifying the fibers by heating and pressing without using a binder resin or a solvent, forming a fiber bundle having a predetermined shape such as a sheet-like body with a rectangular cross section, a cylindrical body, a polygonal column, or a star-shaped polygonal column. It is important that the heating method used here is within a range that does not cause complete fusion of the fibers, and the heating temperature and time may be within a range that allows the purpose of thermoforming to solidify and bind the fibers together with heat and pressure to form a fiber bundle with a binding strength that exceeds the die drawing resistance, and although this varies depending on the type of fiber and the size of the fiber bundle to be manufactured, a fiber bundle is formed in which the fibers are solidified and bound by heat by heating at a temperature equal to or higher than the lower melting point of two types of fibers that have different melting points and equal to or higher than the heat shrinkage completion temperature of the crimp. For example, if PET-based fibers are used as the crimped fibers made of thermoplastic resin and the heat shrinkage completion temperature is 150°C, the fibers can be solidified and bound by heating at 150°C or higher, equal to or higher than the melting point of the fiber with the lower melting point and lower than the melting point of the fiber with the higher melting point. Regarding the strength of the fiber bundle, the degree of fusion of the low melting point fibers can be controlled by adjusting the amount of fiber put in (weight per unit area), heating temperature, and heating time.

[0020] The shape, size, etc. of the fiber bundle for a writing instrument obtained by the above method can be any shape (rectangular cross-sectional shape, sheet-like, cylindrical, polygonal prism, star-shaped polygonal prism), size, thickness, etc., depending on the application, for example, as a batting, pen core, ink guide core, relay core, etc. The fiber bundle obtained by the above method can be cut to any length depending on the use of the fiber bundle, for example, a pen core, an ink guide core, a relay core, etc., and then processed as necessary for each use to obtain the desired fiber bundle for a writing instrument. FIG. 1(a) shows an example of an embodiment of the sheet-shaped fiber bundle A for a writing instrument having a rectangular cross-sectional shape obtained above, and FIG. 3 is a schematic oblique view of a cylindrical fiber bundle B for a writing instrument.

[0021] In the resulting fiber bundle for a writing instrument, it is preferable that the fiber bundle has a substantially uniform density. In order to obtain a fiber bundle having a substantially uniform density, the fiber bundle has a density of 2,000 to 7,000 d / mm 2 This can be achieved by forming a fiber bundle having a yarn density of 100% or more. In addition, in such a manufacturing method, the thickness of the rectangular cross section is 0.1 to 10 mm, the outer diameter of the circular cross section is 0.1 mm or more, and the fiber density is 2,000 d / mm 2 The above fiber bundle can be successfully manufactured. The porosity, hardness, etc. of the fiber bundle for a writing instrument vary depending on the type of ink, the type of writing instrument, etc., and during the above-mentioned production, the fiber bundle density, molding temperature, heating time, etc. can be adjusted to, for example, a porosity of 30 to 80%. In the present disclosure, the "porosity" is calculated as follows. First, a fiber bundle for a writing instrument having a known mass and apparent volume is immersed in water, and after the fiber bundle is sufficiently saturated with water, the mass is measured in a state where it is taken out of the water. From the measured mass, the volume of water that has been saturated in the writing core is derived. The porosity is calculated from the following formula, assuming that the volume of this water is the same as the pore volume of the fiber bundle for a writing instrument. Porosity (unit: %) = (volume of water) / (apparent volume of fiber bundle for writing instrument) x 100

[0022] In the fiber bundle for writing instruments disclosed in this manner, even when the core body has a rectangular or irregular cross section, especially a fiber bundle core with a small diameter, it is possible to obtain a fiber bundle that is suitable for application tools such as writing instruments and cosmetic tools, which has no variation in thread density in the longitudinal direction of the core, is excellent in strength and durability, and can be manufactured simply and efficiently at low cost, without compromising the liquid supply performance of the fiber bundle, such as ink, and which has no variation in thread density in the longitudinal direction of the core.

[0023] Next, the pen tip and writing instrument of the present disclosure will be described. The pen tip of the present disclosure is 1) a pen tip having a writing pen core, characterized in that the writing pen core is composed of the fiber bundle for a writing instrument having the above-mentioned configuration, and 2) a pen tip having an ink guide core that guides ink to the writing portion of the pen tip, characterized in that the ink guide core is composed of the fiber bundle for a writing instrument having the above-mentioned configuration. The writing instrument of the present disclosure is characterized by being provided with a pen tip having a writing pen core of the above-described configuration, and / or a pen tip having an ink guide core that guides ink to the writing portion of the above-described configuration.

[0024] Figures 6 to 11 are drawings showing an example of a pen tip obtained by the fiber bundle for a writing instrument of the present disclosure and an embodiment in which the pen tip is used in a writing instrument. Figures 6 and 7 show the state before and after a cap is attached to a twin-type writing instrument having a pen tip with a writing pen core at both ends and a pen tip with an ink guide core, Figures 8 and 9 are an enlarged view of the pen tip with the writing pen core and drawings of a holder for mounting the writing pen core, and Figures 10 and 11 are an enlarged view of the pen tip with the ink guide core and drawings of a holder for mounting the ink guide core. As shown in Figures 6 and 7, the writing instrument X of this embodiment is configured to include a shaft member 10 which forms the main body of the writing instrument, ink holders 20, 21 which store the ink contained within the shaft member 10, pen tips 30, 50 via tip shafts 15, 16 respectively fixed to both ends of the shaft member 10, and removable caps 70, 71 which surround the pen tips 30, 50, respectively.

[0025] The shaft member 10, which is the main body of the writing instrument, is formed in a cylindrical shape and is made of thermoplastic resins, thermosetting resins, such as polyacetal resin, polyethylene resin, acrylic resin, polyester resin, polyamide resin, polyurethane resin, polyolefin resin, polyvinyl resin, polycarbonate resin, polyether resin, and polyphenylene resin (hereinafter, each of the above resins will be simply referred to as "each resin"), and tip shafts 15 and 16 that hold pen tips 30 and 50 are attached to the openings on both ends, respectively. Ink holders 20 and 21 that store ink are contained within this shaft member 10, and the ink holders 20 and 21 are divided by a partition member 23 in the center, and ink impregnated in the ink holders 20 and 21 is supplied to each of the pen tips 30 and 50.

[0026] The ink holders 20, 21 are impregnated with an ink composition for writing instruments such as water-based ink, oil-based ink, or thermochromic ink, and include, for example, fiber bundles made of one or a combination of two or more types of natural fibers, animal hair fibers, polyacetal resins, acrylic resins, polyester resins, polyamide resins, polyurethane resins, polyolefin resins, polyvinyl resins, polycarbonate resins, polyether resins, polyphenylene resins, etc., processed fiber bundles such as felt, and porous bodies such as sponges, resin particles, and sintered bodies.

[0027] The composition of the writing instrument ink composition to be impregnated into the ink holders 20, 21 is not particularly limited, and can be a suitable blend of water-based ink, oil-based ink, thermochromic ink, etc., depending on the application of the writing instrument (felt pen, marking pen, felt-tip pen, etc.). For example, in the case of an underline pen, etc., the ink can contain a fluorescent dye, such as Basic Violet 11 or Basic Yellow 40, and can also contain a thermochromic microencapsulated pigment, etc. In this embodiment, the ink holders 20 and 21 are impregnated with the same ink composition. However, the ink holders 20 and 21 may be impregnated with inks having different ink compositions.

[0028] As shown in Figures 6 to 9, the pen tip 30 has a writing pen core 31 and is equipped with a holder 40 to which the writing pen core 31 is attached, and the writing pen core 31 is formed from the fiber bundle for a writing instrument having the above-mentioned configuration. The writing pen core 31 of this embodiment has dimensions of 1.0 mm in thickness x 2.0 mm in width x 16 mm in length. The tip end of this writing pen core 31 becomes the writing part 32, and the rear end side is attached inside the tip side of the ink holder 20, so that the tip end of the writing pen core 31 supplies the ink impregnated in the ink holder 20 to the writing part 32.

[0029] As shown in Figures 6 to 9, the holder 40 is fixed to the opening at the tip of the front barrel 15 of the barrel 10 by attaching thereto the writing pen core 31, which serves as the writing core. The holder 40 has a bulging mounting main body portion 41 and, on the front side of the main body portion 41, a flange portion 42 and a plain window frame portion 43 with a trapezoidal cross-section. Mounting holes 44, 45 for attaching the writing pen core 31 are formed inside the mounting main body portion 41 and on the tip side of the window frame portion 43, respectively, so as to mount and hold the writing pen core 31. The mounting body 41 of the holder 40 made of these members has a recessed fitting portion 46a formed on its widthwise outer peripheral surface, and linear air circulation grooves 46b, 46c formed on both sides of the air circulation grooves on its longitudinal outer peripheral surface. The holder 40 thus constructed is made of, for example, synthetic resin, metal, glass, etc.

[0030] 6, 7, 10 and 11, the pen tip 50 has an ink supply core 51, a writing part 52 made of a porous material at the tip side of the ink supply core 51, and is equipped with a holder 60 to which the ink supply core 51 and writing part 52 are attached, the ink supply core 51 being made of the fiber bundle for a writing instrument having the above-mentioned configuration. The ink supply core 51 of this embodiment efficiently guides (supplies) ink impregnated in the ink holder 21 to the writing part 52, and has dimensions of 0.8 mm thick x 1.6 mm wide x 16 mm long.

[0031] As shown in Figures 6, 7, 10 and 11, the retaining body 60 is composed of a plate-shaped retaining portion 61, a flange portion 62 formed integrally with the rear end of the plate-shaped retaining portion 61 and protruding radially outward, and a bulging mounting main body portion 63 formed integrally behind the flange portion 62. The plate-shaped holding part 61 is composed of two plate surface parts 61a, 61b and a plate thickness part 61c that surrounds the front and one side of the plate surface parts 61a, 61b and is formed in the plate thickness direction. The plate thickness part 61c of the plate-shaped holding part 61 holds the writing part 52 consisting of a writing lead. The plate surface parts 61a, 61b are provided on both sides so as to sandwich the plate thickness part 61c. Each plate surface part 61a, 61b is formed by a surface that is approximately perpendicular to the plate thickness part 61c (i.e., a surface that is approximately perpendicular to the plate thickness direction). In addition, the plate surface parts 61a, 61b have continuous triangular uneven bodies 64, 64 formed on both outer surfaces, which gives the plate-shaped holding part 61 moderate flexibility in the plate thickness direction. The thick plate surface portion 61c is formed with a holding groove 65 for holding the writing part 42. Furthermore, a holding groove 66 is formed at the upper end of the plate surface portions 61a and 61b, and the ink guide core 51 is attached to the holding groove 66. A concave fitting portion 63a is formed on the widthwise outer peripheral surface of the mounting main body portion 63 of the holder 60 constructed from these components, and linear air flow grooves 63b, 63c are formed on both sides of the longitudinal outer peripheral surface.

[0032] The entire holder 60 thus configured may be made of a relatively hard synthetic resin, such as polypropylene, polyethylene, polystyrene, polycarbonate, polyethylene terephthalate, polyacetal, acrylic, nylon, acrylonitrile-styrene copolymer resin (AS resin), acrylonitrile-butadiene-styrene copolymer resin (ABS resin), etc. The material constituting the holder 43 may be a synthetic resin having elasticity, and examples of such synthetic resin having elasticity include soft polyethylene, soft polypropylene, nylon, and rubber elastic materials (for example, thermoplastic elastomers such as styrene-based elastomers, olefin-based elastomers, and polyester-based elastomers). The synthetic resin constituting the holder 60 may be a transparent resin, which allows the contact state between the writing part 52 consisting of the writing core and the paper surface to be visually confirmed when writing.

[0033] In the pen tip 30 of the above embodiment, the writing pen core 31 is made of the fiber bundle for writing instruments having the above-mentioned configuration, and even though it has a thin thickness with a rectangular cross section and dimensions of 1.0 mm thick x 2.0 mm wide x 16 mm long, it does not impair the ink supply performance, etc. of the fiber bundle, and there is no variation in thread density in the longitudinal direction of the core, and as a writing pen core, it has excellent strength against writing loads and excellent durability. The pen tip 50 of this embodiment is a pen tip having an ink guide core 51 that guides ink to the writing portion, and the ink guide core 51 is composed of a fiber bundle for a writing instrument having the above-mentioned configuration, and does not impair the ink supply performance, etc. as a fiber bundle, and has no variation in thread density in the longitudinal direction of the core, and also has excellent strength and durability as a sheet-like ink guide core. In addition, in the pen tip 50 of this embodiment, the plate-shaped holding part 61 has the uneven bodies 64, 64 having a depth in the plate thickness direction, so that the plate-shaped holding part 61 can have appropriate flexibility in the plate thickness direction. Moreover, because the plate-shaped holding part 61 is made of an elastic synthetic resin, the plate-shaped holding part 61 can reliably obtain flexibility in the plate thickness direction.

[0034] The writing instrument of the present disclosure, which has pen tip 30 and pen tip 50 on both ends, does not impair the ink supply performance or writing performance as a fiber bundle, and there is no variation in thread density in the longitudinal direction of the core, making it strong and durable as a writing pen core or ink supply core.

[0035] The writing instrument of the present disclosure is not limited to the above-described embodiment, and can be further modified in various ways without departing from the technical concept of the present disclosure. In the above embodiment of the writing instrument, a twin-type writing instrument has been described in detail, which is equipped with a pen tip 30 having a writing pen core 31 at both ends of the barrel 10, and a pen tip 50 having an ink guide core 51 that guides ink to the writing portion 52. However, it may also be a single-type writing instrument, each of which has a pen tip 30 having a writing pen core 31, or a writing instrument equipped with a pen tip 50 having an ink guide core 51 that guides ink to the writing portion 52. In addition, in each of the above embodiments, the ink (water-based ink, oil-based ink, thermochromic ink) for writing instruments is described, but the ink may also be a liquid such as a liquid cosmetic, a liquid medicine, a coating liquid, or a correction fluid. EXAMPLES

[0036] Next, the present disclosure will be described in further detail with reference to examples and comparative examples, but the present disclosure is not limited to the following examples, etc.

[0037] Example 1 A fiber bundle for a writing instrument was obtained by the method described below using fibers made of the thermoplastic resin described below. (Multifilament of long fibers with different melting points: core-sheath type composite fiber) Core-sheath composite fiber: A composite fiber (thickness 5 denier) with a sheath made of polyethylene terephthalate copolymer with a low melting point (melting point: 160°C) and a core made of polyethylene terephthalate with a high melting point (melting point: 250°C). (crimped fiber) The above core-sheath type composite fiber was subjected to a crimping treatment by false twist processing. The crimp ratios of the crimped fibers were calculated to be 5% and 15%, and the content of the crimped fibers was 100% by mass for both types of fibers relative to the total amount of the fiber bundle.

[0038] (Method for manufacturing fiber bundles) As shown in FIG. 4, the fibers were aligned in the longitudinal direction in a thermoforming machine 10, and the thermoplastic resin fibers were solidified and bound to form a fiber bundle. The solidification and binding temperature was 160°C, and the time for passing through the die was 30 seconds. Specifically, the obtained fiber bundle was a sheet-like fiber bundle with a thickness of 1.0 mm and a width of 2.0 mm. At this time, the fiber with a crimp rate of 5% had a fiber density of 5000 d / mm 2 The other fiber had a crimp rate of 15% and a fiber density of 3000 d / mm 2 The porosity was adjusted to 65%. When this fiber bundle was examined using a scanning electron microscope (SEM), it was confirmed that a uniform cross-sectional structure had been formed with almost no difference in density distribution between the center of the core and the skin, as shown in Figure 5(a). This fiber bundle was cut into a length of 16 mm to form a writing pen core 31 for the pen tip 30 shown in FIG.

[0039] Example 2 A fiber bundle for a writing instrument was obtained by the method described below using fibers made of the following thermoplastic resin. (Multifilament of long fibers with different melting points: core-sheath type composite fiber) Core-sheath composite fiber: A composite fiber (thickness 5 denier) with a sheath made of polyethylene terephthalate copolymer with a low melting point (melting point: 160°C) and a core made of polyethylene terephthalate with a high melting point (melting point: 250°C). (crimped fiber) The above core-sheath type composite fiber was subjected to a crimping treatment by false twist processing. The crimp rate of the crimped fiber was calculated to be 5%, and the content of the crimped fiber was set to 100% by mass based on the total amount of the fiber bundle.

[0040] (Method for manufacturing fiber bundles) As shown in FIG. 4, the fibers were aligned in the longitudinal direction in a thermoforming machine 10, and the thermoplastic resin fibers were solidified and bound together to form a fiber bundle. The solidification and binding temperature was 160°C, and the time for passing through the die was 30 seconds. The obtained fiber bundle had a thickness of 0.8 mm, a width of 1.6 mm, and a fiber density of 4,000 d / mm. 2 The sheet-like fiber bundle having a porosity of 60% was obtained. When this fiber bundle was examined using a scanning electron microscope (SEM), it was confirmed that a uniform cross-sectional structure had been formed with almost no difference in density distribution between the center of the core and the skin, similar to that shown in Figure 5(a). This fiber bundle was cut into a length of 16 mm to form an ink supply core 51 for the pen tip 50 shown in FIG.

[0041] Example 3 A fiber bundle for a writing instrument was obtained by the method described below using fibers made of the following thermoplastic resin. (Multifilament of long fibers with different melting points: Side-by-side composite fiber) Side-by-side composite fiber: Composite fiber (thickness 5 denier) with one side made of 66 nylon (melting point: 265°C) and the other side made of 6 nylon (melting point: 225°C) in a mass ratio of 1:1. (crimped fiber) The side-by-side type composite fiber was subjected to a crimping treatment by a push-in type (gear type) crimping process. The crimp rate of the crimped fiber was calculated to be 8%, and the content of the crimped fiber was set to 100% by mass based on the total amount of the fiber bundle.

[0042] (Method for manufacturing fiber bundles) As shown in FIG. 4, the fibers were aligned in the longitudinal direction in a thermoforming machine 10, and the thermoplastic resin fibers were solidified and bound together to form a fiber bundle. The solidification and binding temperature was 225°C, and the time for passing through the die was 30 seconds. The obtained fiber bundle had a thickness of 1.0 mm, a width of 2.0 mm, and a fiber density of 5,000 d / mm. 2 The sheet-like fiber bundle having a porosity of 50% was obtained. When this fiber bundle was examined using a scanning electron microscope (SEM), it was confirmed that a uniform cross-sectional structure had been formed with almost no difference in density distribution between the center of the core and the skin, as shown in Figure 5(a). This fiber bundle was cut into a length of 16 mm to form a writing pen core 31 for the pen tip 30 shown in FIG.

[0043] Comparative Example 1 In the above-mentioned Example 1, crimped fibers of a core-sheath type multifilament having a different melting point were not used, and instead, a method was used in which a conventional single-component polyester multifilament crimped fiber was molded, impregnated with a polyurethane binder resin, and the binder was solidified in a heating furnace. Instead, the fiber was produced in the same manner as in the above-mentioned Example 1. The obtained fiber bundle had a thickness of 1.0 mm, a width of 2.0 mm, and a fiber density of 5,000 d / mm 2 The crimp ratio of the crimped fibers was 13%, and the content of the crimped fibers was 100% by mass relative to the total amount of the fiber bundle. The porosity was 50%. When this fiber bundle was examined using a scanning electron microscope (SEM), it was found that, as shown in Figure 5(b), the polyurethane binder resin had concentrated in the outer skin of the core due to the effect of the solvent evaporating, resulting in an uneven cross-sectional structure with a large difference in density distribution between the center and outer skin of the core. This fiber bundle was cut into a length of 16 mm to form a writing pen core 31 for the pen tip 30 shown in FIG.

[0044] The fiber bundles obtained in Examples 1 to 3 and Comparative Example 1 were used to assemble the pen body shown in FIG. 6, and the writing performance was evaluated. As a result, it was confirmed that the pen body was superior to the fiber bundle of Comparative Example 1, which used a conventional binder, in the following points. (1) By adjusting the amount of fiber (weight per unit area) and the heating temperature and heating time, sufficient strength and durability for writing was obtained even without using a binder. (2) There is no bias in the binder, and the hardness of the pen core is consistent, so there is no discomfort when writing due to directional differences. (3) Ink absorption improved by more than 10%. (4) The ink flowability and spreadability became uniform.

[0045] (Examples of pen tips and writing implements) A writing instrument conforming to Figs. 6 to 11 was produced using the fiber bundles obtained in Examples 1 and 2 as the writing pen core 31 and the ink supply core 51. The dimensions of the writing instrument, each writing pen core 31, and the ink supply core 51 were as shown above. Ink for the writing instrument having the following composition was used.

[0046] (Writing Instrument Composition) Shaft tube 10: Made of polypropylene, length 100 mm, central inner diameter 8 mm, outer diameter 10 mm Ink holder 20, 21: Made of PET fiber, porosity 85%, size: φ6×45mm Holder 40: Acrylic resin, plain window frame: 5 x 4 x 11.5 mm Writing section 52: Sintered polyethylene core, porosity 50%, size: 4 x 3 x 6 mm Holder 60: Acrylic resin, plain window frame: 5 x 2.5 x 12 mm

[0047] (Ink composition for writing instruments, ink color: black) As the ink for the writing instrument, an ink having the following composition (total 100% by mass) was used. Surfactant: Megafac F410 (fluorine-based anionic surfactant, perfluoroalkyl-containing carboxylate, manufactured by DIC Corporation) 1% by mass Antifungal agent: 0.2% by mass of benzoisothiazolin-3-one Glyceryl glucoside aqueous solution: αGG (high concentration α-glyceryl glucoside aqueous solution, 60% α-glyceryl glucoside aqueous solution, manufactured by JTS Co., Ltd.) 3% by mass Pigment water dispersion: FUJI SP BLACK 8041 (black pigment water dispersion, solid content 20%, manufactured by Fuji Pigment Co., Ltd.) 20% by mass Water-soluble organic solvent: glycerin 5% by mass Water-soluble organic solvent: 5% by mass of ethylene glycol Water (solvent): Ion-exchanged water 65.8% by mass Viscosity (25°C): 3.6 mPa·s (Complate type viscometer, TOKIMEC, TV-20) Surface tension (25°C): 40mN / m (automatic surface tensiometer, Kyowa Interface Science Co., Ltd., DY-300)

[0048] It was confirmed that the writing instrument X, which is equipped with the writing pen core 31 and the pen tip 30 using the ink supply core 51 made of the fiber bundle obtained in Examples 1 and 2 above, and the pen tip 50, can be obtained without compromising the ink supply performance of the writing instrument, without variation in thread density in the longitudinal direction of the core, and has excellent strength and durability. [Industrial Applicability]

[0049] It is possible to obtain an ink guide core used for the pen tip of a writing instrument, a fiber bundle for a writing instrument suitable for a writing pen core, and a pen tip and a writing instrument using the same. [Explanation of symbols]

[0050] X writing instrument A Fiber bundle for writing implements B. Fiber bundle for writing implement 30 Pen Tips 31 Writing pen core 50 Pen Tip 51 Ink guide core

Claims

1. A fiber bundle for liquid cosmetics or liquid medicines used as an ink guide core for an application section or as an application pen core, the fiber bundle for liquid cosmetics or liquid medicines being composed of multifilaments of long fibers having fibers with different melting points, and the multifilaments containing at least crimped fibers.

2. 2. The fiber bundle for liquid cosmetics or liquid medicines according to claim 1, characterized in that the crimped fibers have a crimp ratio calculated by the following formula (I) of 1 to 50%. Crimp ratio = (crimp width ÷ crimp length) × 100 ... (I) (In the above formula (I), the distance from the peak to the peak of the wavy shape of the fiber is defined as the "crimp length", and the distance between the peak (peak) and the bottom (valley) of the wave in the direction perpendicular to the crimp length is defined as the "crimp width".)

3. 3. The fiber bundle for liquid cosmetics or liquid medicines according to claim 1 or 2, characterized in that the content of the crimped fibers is 10 to 100% by mass based on the total amount of the fiber bundle for liquid cosmetics or liquid medicines.

4. 4. The fiber bundle for liquid cosmetics or liquid medicines according to claim 1, wherein the cross-sectional shape is rectangular.

5. A pen tip having an applicator, the applicator being made of a fiber bundle for liquid cosmetics or liquid medicines according to any one of claims 1 to 4.

6. A pen tip having an ink guide core for guiding ink to an application part, the ink guide core being composed of a fiber bundle for liquid cosmetics or liquid medicines according to any one of claims 1 to 4.

7. An applicator comprising the applicator part according to claim 5 or 6.

Images