Fiber core, and method for manufacturing the same

Abstract

To provide a fiber core that can be manufactured efficiently and with good yield. [Solution] The fiber core includes a yarn made up of multiple long fibers. Some or all of the yarn made up of multiple long fibers is subjected to both or either conductive processing and / or dyeing.

Description

Technical Field

[0001] The present invention relates to a fiber core and a method for manufacturing the same.

Background Art

[0002] As described in Japanese Patent Application Laid-Open No. 2013-200618 (Patent Document 1), a so-called touch pen or stylus pen for operating the surface of a liquid crystal panel (also referred to as a touch panel) of an electronic device such as a tablet or a smartphone by replacing a finger or the like is known. Such a touch pen has a pen-like shape having a shaft and a pen tip. In particular, for the above pen tip, in order to prevent damage to the above touch panel, a resin, rubber, or a fiber core formed by bundling a plurality of fibers made of a relatively soft material is usually applied. Further, in the case of a touch pen for use with a capacitive touch panel, the pen tip may be formed of a conductive material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the pen tip is formed of the resin, there is a problem that the contact sound (collision sound) between the pen tip and the touch panel becomes relatively large. When the pen tip is formed of the fiber core, after a plurality of fibers are bundled to form the fiber core, processes such as conductive processing and dyeing processing are performed, so that deformation or loss of the fiber core frequently occurs, and uneven processing or processing stains frequently occur, so that the fiber core tends not to be manufactured with good yield. There was also a problem that there was no general-purpose processing machine or the like for manufacturing the fiber core.

[0005] In view of the above circumstances, the object of the present invention is to provide a fiber core for obtaining the above-mentioned pen tip for a so-called touch pen or stylus pen with good yield, and a method for manufacturing the same. [Means for solving the problem]

[0006] The inventors diligently studied to solve the above problems and arrived at the present invention. The inventors reviewed the manufacturing process of the fiber core. Specifically, they found that by applying conductive processing, dyeing processing, etc., to each individual fiber constituting the fiber core, and then bundling the fibers to form the fiber core, the fiber core can be obtained with good yield without deformation or defects, and thus the present invention was completed. The present invention has the following specific features.

[0007] [1] The present invention relates to a fiber core comprising a yarn made of a plurality of long fibers, wherein part or all of the yarn made of the plurality of long fibers is subjected to both or either conductive processing and dyeing. [2] In the fiber core described in [1] above, the yarn consisting of the plurality of long fibers may be hardened with resin as a bundle of long fibers. [3] In the fiber core described in [1] or [2] above, the yarn made of the long fibers may include at least one selected from the group consisting of nylon polymers, polyester polymers, (meth)acrylic polymers, and urethane polymers. [4] The present invention is a method for producing a fiber core, comprising the steps of: preparing a yarn made of a plurality of long fibers; obtaining a fiber core precursor by subjecting a part or all of the yarn made of the plurality of long fibers to both or either a conductive processing treatment and a dyeing treatment; and obtaining a fiber core by bundling the fiber core precursors and solidifying them with resin. [Effects of the Invention]

[0008] According to the present invention, a fiber core for obtaining the above-mentioned pen tip of a so-called touch pen or stylus pen with good yield, and a method for manufacturing the same are provided. [Brief explanation of the drawing]

[0009] [Figure 1] This is an explanatory diagram showing an example of a pen tip formed from a fiber core according to this embodiment. [Figure 2] This is a flowchart illustrating the manufacturing method for the fiber core according to this embodiment. [Modes for carrying out the invention]

[0010] The embodiments of the present invention (hereinafter also referred to as "this embodiment") will be described in more detail below. In this specification, the notation in the form of "A~B" means the upper and lower limits of a range (i.e., A or greater and B or less), and it should be noted that if no unit is specified for A, but a unit is specified only for B, the unit for A and the unit for B are the same.

[0011] [Fiber core] The fiber core according to this embodiment includes a yarn made of multiple long fibers. Some or all of the yarn made of multiple long fibers is subjected to both or either conductive processing and / or dyeing. A fiber core having such characteristics can be obtained with good yield and can be applied as a pen tip for a so-called touch pen or stylus pen with stable quality. The fiber core may be formed only from a yarn made of multiple long fibers, and may also include yarn made of other fibers such as short fibers, as long as the yarn made of multiple long fibers is the main component of the fibers contained in the fiber core. The term "main component" refers to fibers that account for more than 50% by mass of the fibers constituting the fiber core.

[0012] <Yarn made from long fibers> The fiber core described above includes a yarn made of multiple long fibers, as stated above. In this specification, "long fiber" refers to a fiber in which a single fiber is long, and although there is no clear standard for its length, as a guideline, it refers to a fiber in which the length of a single fiber is 1000m or more. The yarn made of the above long fibers may be untwisted, or it may have portions that are twisted about 1 to 100 times per meter.

[0013] (Conductive processing) Some or all of the yarn consisting of the multiple long fibers described above is subjected to both or either conductive processing and / or dyeing. The yarn consisting of the multiple long fibers contained in the fiber core may be subjected to conductive processing at a rate of 1% to 100% by mass. Various known conductive processing methods may be used for the conductive processing of the yarn consisting of the multiple long fibers, including a method of adsorbing monovalent copper ions onto the fibers. The yarn consisting of the multiple long fibers may be subjected to conductive processing at a rate of 5% to 100% by mass, and may be subjected to conductive processing at a rate of 10% to 25% by mass.

[0014] (Dialysis treatment) Furthermore, the yarn consisting of the above-mentioned multiple long fibers may be dyed at a rate of 1% to 100% by mass. Various known dyeing treatments, such as methods of adsorbing pigments or dyes onto the fibers, may be used for the dyeing treatment of the yarn consisting of the above-mentioned multiple long fibers. The type and amount of pigments and dyes used may be appropriately selected according to the application of the fiber core. The yarn consisting of the above-mentioned multiple long fibers may be dyed at a rate of 5% to 50% by mass, or at a rate of 10% to 25% by mass. The yarn consisting of the above-mentioned multiple long fibers may be subjected to conductive processing only at a rate of 1% to 100% by mass, or to be dyed only at a rate of 1% to 100% by mass. The yarn consisting of the above-mentioned multiple long fibers may be dyed after conductive processing, or to be dyed first and then subjected to conductive processing.

[0015] (Long fiber bundles, fixed with resin) In the fiber core described above, the thread consisting of the multiple long fibers may be hardened with resin as a bundle of long fibers. In this case, the dimensional accuracy of the fiber core is improved, and a pen tip of stable quality can be provided without secondary processing related to dimensions.

[0016] The yarn consisting of multiple long fibers described above is solidified with resin as a long fiber bundle, for example, as follows. First, the yarn consisting of multiple long fibers is formed into a rod shape by heat compression molding, and then a resin liquid is immersed in the rod shape to obtain a resin liquid-impregnated rod shape. Subsequently, the resin liquid-impregnated rod shape is subjected to internal heating, causing the solvent in the resin liquid to evaporate from the resin liquid-impregnated rod shape, and the resin liquid-impregnated rod shape is hardened by the resin component in the resin liquid. In this way, the yarn consisting of multiple long fibers can be solidified with resin as a long fiber bundle. A thermosetting resin may be used as the resin component in the resin liquid. Specifically, epoxy resin, urethane resin, phenolic resin, etc., are examples of the resin component. The solvent in the resin liquid may be a solvent that can be recovered and reused and has a fast evaporation rate, and specifically, methanol, acetone, ethyl acetate, methylene chloride, etc.

[0017] (Material of long fibers) The yarn made of the long fibers described above may contain at least one selected from the group consisting of nylon polymers, polyester polymers, (meth)acrylic polymers, and urethane polymers. In particular, the yarn made of the long fibers may contain both or either polyester polymers and (meth)acrylic polymers. The yarn made of the long fibers may be used alone as one of the above-mentioned options, or two or more may be used in mixture form. In this specification, "(meth)acrylic polymer" means acrylic polymer or methacrylic polymer. The material of the yarn made of the long fibers may be appropriately selected depending on the application to which the fiber core is applied, such as a pen tip.

[0018] The yarn made of the above-mentioned long fibers may, for example, be 2 denier or more and 10 denier or less per fiber (1 filament). As a result, the yarn made of the above-mentioned long fibers may be 200 denier or more and 1000 denier or less. The denier of the long fiber bundle forming the fiber core may be 350 or more and 130000 or less. The above-mentioned "denier" is a unit of fineness representing the thickness of fibers, yarns, etc. A fiber or yarn with a mass of 1 g for 9000 m is called 1 denier, meaning that the larger the number, the thicker the yarn.

[0019] (Shape, etc.) The above-mentioned fiber core typically has a diameter of 1 mm or more and 10 mm or less, and the axial length may be 10 mm or more and 200 mm or less, but is not limited to this dimension. The above-mentioned fiber core may have a diameter of 2 mm or more and 8 mm or less, and the axial length may be 15 mm or more and 100 mm or less. The above-mentioned fiber core may have a diameter of 3 mm or more and 6 mm or less, and the axial length may be 20 mm or more and 50 mm or less.

[0020] When the above-mentioned fiber core includes a yarn made of long fibers subjected to conductive processing, its electrical resistance value may be 100 Ω / 10 cm or more and 10 MΩ / 10 cm or less. The above-mentioned electrical resistance value may also be 200 Ω / 10 cm or more and 1 MΩ / 10 cm or less. When the above-mentioned fiber core includes a yarn made of long fibers subjected to conductive processing or dyeing processing, designability can be imparted by intentionally arranging these processed long fibers in the fiber core. Specifically, the above-mentioned fiber core can be provided with a cross, dots, a mottled pattern, or other designs on the radial cross-section of the long fiber bundle.

[0021] (Use) The above-mentioned fiber core may be used, for example, as part or all of a pen tip. In this case, the fiber core may be used as is, or its shape may be appropriately processed to form part or all of a pen tip. When the above-mentioned pen tip contains conductively treated long fibers in the fiber core, it can be applied to so-called touch pens or stylus pens for operating surfaces such as touch panels of electronic devices. When the above-mentioned pen tip contains dyed long fibers in the fiber core, it can be applied not only to capacitive touch pens but also to the pen tips of colorful pens.

[0022] The above-mentioned fiber core may be applied not only to pen tips, but also to volatile fragrance absorbent fiber sticks, hairbrushes, anti-static brushes, and the like.

[0023] Figure 1 is an explanatory diagram showing an example of a pen tip formed from a fiber core according to this embodiment. As shown in Figure 1, the pen tip 100 is formed from a fiber core 1. In the pen tip 100 of Figure 1, multiple long fibers are subjected to conductive processing, and then these are hardened together as a long fiber bundle with resin. The resin-hardened long fiber bundle is then processed into a thin rod shape to form the fiber core 1. 100% by mass of the long fibers forming the fiber core 1 are conductively processed. Therefore, the color of the fiber core 1 is actually predominantly black. The shape of the pen tip shown in Figure 1 has a diameter of 2 mm and an axial length of 30 mm.

[0024] [Method for manufacturing fiber cores] The above-mentioned fiber core can be manufactured by any appropriate method. However, the above-mentioned fiber core can be obtained with good yield by the fiber core manufacturing method according to this embodiment, which will be described below. That is, the fiber core manufacturing method includes the steps of: preparing a yarn made of a plurality of long fibers; obtaining a fiber core precursor by subjecting a part or all of the yarn made of the plurality of long fibers to both or either conductive processing and dyeing; and obtaining a fiber core by bundling the fiber core precursor and solidifying it with resin. The fiber core manufacturing method may include a post-processing step after the step of obtaining the fiber core in which the fiber core is processed into a shape suitable for various applications such as pen tips. Hereinafter, each step included in the fiber core manufacturing method will be described with reference to Figure 2. Figure 2 is a flowchart illustrating the fiber core manufacturing method according to this embodiment.

[0025] <Preparation steps> As shown in Figure 2, the above method for manufacturing a fiber core includes a step S10 for preparing a yarn made of multiple long fibers. The purpose of the above preparation step S10 is to prepare multiple yarns made of long fibers to be used as fibers for obtaining a fiber core with good yield. The yarn made of long fibers may include at least one selected from the group consisting of nylon polymers, polyester polymers, (meth)acrylic polymers, and urethane polymers, as described above. One fiber (one filament) constituting the yarn made of long fibers may be 2 denier or more and 10 denier or less, and the yarn made of long fibers may be 200 denier or more and 1000 denier or less.

[0026] <Process for obtaining a fiber core precursor> The above-described method for manufacturing a fiber core includes a step S20 to obtain a fiber core precursor by subjecting a part or all of the yarn made up of multiple long fibers to both or either a conductive processing treatment and a dyeing treatment. The purpose of the step S20 to obtain the fiber core precursor is to apply both or either a conductive processing treatment and a dyeing treatment to the yarn made up of multiple long fibers before solidifying it with resin, in order to obtain a fiber core with good yield. In this step, by subjecting both or either a conductive processing treatment and a dyeing treatment to a part or all of the yarn made up of multiple long fibers, the occurrence of deformation or defects, processing unevenness or unevenness in the fiber core can be reduced.

[0027] The conductive processing treatment for the yarn consisting of the multiple long fibers described above may be any known conductive processing treatment, including a method of adsorbing monovalent copper ions onto the fibers, or commercially available carbon composite conductive long fibers may be used as is. The yarn consisting of the multiple long fibers may be conductively processed at a rate of 1% to 100% by mass. The dyeing treatment for the yarn consisting of the multiple long fibers may be any known dyeing treatment, such as a method of adsorbing disperse dyes onto the fibers. The yarn consisting of the multiple long fibers may be dyed at a rate of 1% to 100% by mass. The type and amount of pigments and dyes used in the dyeing treatment may be appropriately selected according to the application of the fiber core. The yarn consisting of the multiple long fibers may be subjected to conductive processing only, dyeing only, or both conductive processing and dyeing. A fiber core precursor is obtained as a result of the above.

[0028] <Process for obtaining the fiber core> The above method for manufacturing a fiber core includes step S30, which involves bundling the fiber core precursors and solidifying them with resin to obtain a fiber core. The purpose of step S30 for obtaining the fiber core is to bundle the fiber core precursors, which are multiple long fibers that have undergone both or either conductive processing and / or dyeing processing in part or in whole, and solidify them with resin. This allows for the high yield of fiber cores without deformation, defects, or uneven processing.

[0029] In step S30, which is the process for obtaining the fiber core, the fiber core is obtained from the fiber core precursor by the following operation. First, the fiber core precursor is formed into a rod shape by heat compression molding. Specifically, the fiber core precursor is inserted into a pipe or die heated by a heating block having an inner diameter with the same cross-sectional shape as the radial cross-section of the fiber core, and the rod shape is obtained by performing heat molding and compression molding simultaneously. The temperature of the pipe or die during molding varies depending on the type of long fiber. For example, if the material of the yarn made of the long fiber is a nylon polymer, the temperature may be 170 to 215°C. If the material of the yarn made of the long fiber is a polyester polymer, the temperature may be 210 to 250°C. If the material of the yarn made of the long fiber is a (meth)acrylic polymer, the temperature may be 190 to 250°C. In all cases, the temperature may be approximately +250°C above the softening point of each fiber. The molding time may be 10 to 50 seconds, and the material of the pipe or die may be metal, alloy, or fluororesin such as TFF or FBE. If a cross, dot, mottled pattern, or other design is to be applied to the radial cross-section of the fiber core, the fiber core precursor may be placed in the pipe or die so that the intended design appears in the fiber core.

[0030] Next, a resin-impregnated rod is obtained by immersing the rod in the resin liquid. The rod is passed through an orifice having an inner diameter with the same cross-sectional shape as the pipe or die, and immersed in a resin liquid tank, thereby impregnating the rod with the resin liquid and obtaining the resin-impregnated rod. Thermosetting resins such as epoxy resin, urethane resin, and phenolic resin may be used as the resin component in the resin liquid. The solvent in the resin liquid may be a solvent that can be recovered and reused and has a fast evaporation rate, such as methanol, acetone, ethyl acetate, or methylene chloride. Specifically, methanol, acetone, ethyl acetate, methylene chloride, etc. A polar solvent with a relatively high dielectric constant as a dielectric, such as phenol or cresol having a hydroxyl group in the molecule, or dimethylformamide or dimethylacetamide having a carbonyl group, may be added to the solvent in the resin liquid at a concentration of 1 to 5% by mass relative to the total amount of the resin liquid. The resin content of the resin liquid may be 4 to 30% by mass.

[0031] Next, the resin-impregnated rod is passed through the orifice and introduced into the same pipe or die, and is internally heated, for example, by high frequency. This causes the solvent in the resin liquid to evaporate and the resin to gel, thereby hardening the resin-impregnated rod. After that, the resin-impregnated rod is further dried to obtain the fiber core.

[0032] <Post-processing steps> The above-described method for manufacturing a fiber core may include a post-processing step S40 after the step S30 for obtaining the fiber core, in which the fiber core is processed into a shape suitable for various applications such as pen tips. This allows the fiber core to be used as a material having a shape suitable for various applications. The post-processing in the post-processing step S40 may be performed by appropriate means such as molding, grinding, or polishing.

[0033] <Effects and Effects> The above-described method for manufacturing fiber cores reduces the occurrence of deformation or defects, as well as processing inconsistencies or unevenness, resulting in a high yield of the fiber cores. This provides fiber cores with stable quality and rich color, enabling applications such as the tips of touch pens or stylus pens, conductive and antistatic fiber cores, fragrance sticks (reed diffusers) with unprecedented lengths of 20-40 cm, and hairbrush bristles. [Examples]

[0034] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0035] [Manufacturing of fiber cores] <Example 1: Dyed fiber core> (Preparation process) A commercially available long fiber yarn made of polyester (PET) was prepared, consisting of 96 filaments with a fineness of 3 denier per strand.

[0036] (Process for obtaining a fibrous core precursor) One kilogram of yarn made from the long fibers described above was wound onto a dyed straight tube, and 30 of these dyed straight tubes (total yarn weight: 30 kg) were dyed with a black disperse dye in a cheese dyeing machine. After drying, the 30 yarns made from the long fibers described above were wound onto a pineapple cone to obtain a fiber core precursor.

[0037] (Process for obtaining the fiber core) The 30 fiber core precursors, each wound around the pineapple cone, were bundled together and treated with 100°C steam for 20 minutes to impart linearity to the fiber core precursors. Then, referring to Japanese Patent Publication No. 49-093122, the fiber core precursors were solidified as long fiber bundles with resin. Urethane resin was used as the resin component, and acetone was used as the solvent. The long fiber bundles solidified with resin were then cut to an axial length of 500 mm. Subsequently, they were cut to an axial length of 30 mm to obtain the fiber core of Example 1 (length 30 mm) with a diameter of 1.9 mm.

[0038] (post-process) By molding the fiber core of Example 1, a thin, rod-shaped pen tip with a diameter of 1.9 mm and an axial length of 30 mm was prepared, as shown in Figure 1.

[0039] <Example 2: Conductive processed fiber core> (Preparation process) A commercially available long fiber yarn made of polyester (PET) was prepared, consisting of 96 filaments with a fineness of 3 denier per strand.

[0040] (Process for obtaining a fibrous core precursor) Thirty kilograms of yarn consisting of the above-mentioned long fibers were prepared, and the entire amount was subjected to conductive processing using a known conductive processing method with monovalent copper ions, with reference to Japanese Patent Publication No. 55-051873. Subsequently, the 30 kilograms of conductively processed yarn consisting of long fibers were wound onto 30 pineapple cones to obtain a fiber core precursor.

[0041] (Process for obtaining the fiber core) The 30 fiber core precursors, each wound around the pineapple cone, were bundled together and treated with 100°C steam for 20 minutes to impart linearity to the fiber core precursors. Then, referring to Japanese Patent Publication No. 49-093122, the fiber core precursors were solidified as long fiber bundles with resin. Urethane resin was used as the resin component, and acetone was used as the solvent. The long fiber bundles solidified with resin were then cut to an axial length of 500 mm. Subsequently, they were cut to an axial length of 30 mm to obtain the fiber core of Example 1 (length 30 mm) with a diameter of 1.9 mm.

[0042] (post-process) The fiber core of Example 2 was subjected to a molding process to prepare a thin, rod-shaped pen tip with a diameter of 1.9 mm and an axial length of 30 mm, as shown in Figure 1. The electrical resistance of the fiber core of Example 2 was measured and found to be 200 Ω / 10 cm.

[0043] [Consideration] During the manufacturing of the fiber cores in Examples 1 and 2, no deformation, defects, or uneven or patchy dyeing occurred. Therefore, it was suggested that these fiber cores could be manufactured with a high yield.

[0044] As described above, embodiments and examples of the present invention have been explained, but it is also intended from the outset that the configurations of each of the above embodiments and examples may be combined as appropriate.

[0045] The embodiments and examples disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0046] 1 fiber core, 100 pen tip, S10 preparation process, S20 process to obtain fiber core precursor, S30 process to obtain fiber core, S40 post-processing process.

Claims

1. It contains yarn made of multiple long fibers, A fiber core in which some or all of the yarn, which consists of the plurality of long fibers, is subjected to both or either conductive processing and dyeing.

2. The fiber core according to claim 1, wherein the yarn consisting of the plurality of long fibers is hardened with resin as a bundle of long fibers.

3. The fiber core according to claim 1 or claim 2, wherein the yarn consisting of the long fibers comprises at least one selected from the group consisting of nylon polymers, polyester polymers, (meth)acrylic polymers, and urethane polymers.

4. The process of preparing a yarn made of multiple long fibers, A step of obtaining a fiber core precursor by subjecting a part or all of the yarn consisting of the plurality of long fibers to both or either conductive processing and dyeing treatment, A method for producing a fiber core, comprising the step of bundling the fiber core precursors and solidifying them with resin to obtain a fiber core.

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