Liquid container for applicator

Abstract

To provide a liquid storage member for an applicator, in which the liquid storage member is made of paper, and an ink follower is charged into a rear end portion of an ink in the paper-made liquid storage pipe, and the liquid storage member for an applicator is capable of preventing leakage and backflow of the ink follower.SOLUTION: The liquid storage member for an applicator of the present invention includes: a liquid storage pipe made of a paper substrate; and an ink follower having a yield stress of 16 Pa or more and preferably a phase angle of 35° or more when shear strain amplitude at 25°C and 1 Hz is 0 to 30%. The ink follower is suitable as a paper refill for writing instruments.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an ink-following body that is filled into the rear end of the ink of a paper liquid storage tube, in a liquid storage member for an applicator made of paper material. [Background technology]

[0002] Traditionally, transparent or translucent plastics such as polypropylene have been used for the ink reservoirs of writing instruments such as ballpoint pens. However, in recent years, with growing momentum to address global environmental issues, including reducing the use of plastics, proposals focusing on plastic-free alternatives have been made for each component of writing instruments.

[0003] For example, Patent Document 1 discloses an ink storage member for a writing instrument that uses a multilayered ink storage tube, in which one or more layers of other resins are molded inside a storage tube base made of biodegradable resin. According to this document, the containment tube base, molded from biodegradable resin, biodegrades over time, thus contributing to a reduction in the amount of waste to be disposed of.

[0004] On the other hand, a writing instrument has also been proposed that uses paper as a base material, laminated with a synthetic resin or metal such as aluminum that has barrier properties, and has a barrel made by spiral molding this composite material (Patent Document 2). To improve water resistance and gas barrier properties, this barrel has a structure in which, from the outer surface of the barrel, two layers of aluminum foil label paper with a kraft paper backing and liner paper are layered, followed by a polyethylene layer on the inner surface, and then a polyester film with an aluminum vapor-deposited film on the outside. According to Patent Document 2, by using a composite material including a paper base material for the barrel, it is possible to provide a writing instrument that can achieve low pollution while maintaining durability.

[0005] Furthermore, Patent Document 3 discloses a liquid-containing member for an applicator having at least three layers: an inner layer of a paper substrate, an intermediate layer formed on the outer circumferential surface of the inner layer and being a metal layer or a silica vapor-deposited layer, and an outer layer formed on the outer circumferential surface of the intermediate layer and being made of a paper substrate. In this liquid-containing member, the paper substrate laminate and the outer layer are wound in a spiral shape in contact with each other so that their adjacent surfaces do not overlap, and ink leakage is prevented by leaving a gap of 1 mm or more and half the width of the outer layer between the joints of the outer layers and between the paper substrate laminates.

[0006] Patent Document 4 discloses an ink reservoir for a writing instrument, in which an ink reservoir tube is constructed using paper as a base material, and one end of the ink reservoir tube is connected to a connection portion formed on a writing member or an intermediate member that supports the writing member. In this ink reservoir, a locking means capable of ensuring a certain connection strength to the ink reservoir tube is provided at the connection portion of the intermediate member that supports the writing member, thereby providing a practical writing instrument. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2001-146091 [Patent Document 2] Japanese Patent Application Publication No. 62-70097 [Patent Document 3] Japanese Patent Publication No. 2021-16976 [Patent Document 4] Japanese Patent Publication No. 2020-172044 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, when ink and ink-following materials were filled into ink reservoirs designed to be plastic-free, the adhesion and frictional resistance between the inner wall of the ink reservoir and the ink-following material were insufficient. As a result, the ink-following material would sometimes backflow, scattering or leaking into the ink. Furthermore, when a certain amount of ink was consumed through writing, the inner wall of the ink reservoir would become wet with ink, further weakening the adhesion between the follower and the inner wall of the ink reservoir, making it more slippery. This resulted in increased likelihood of backflow and leakage of the ink-following material, negatively impacting not only the performance but also the appearance of the writing instrument. Therefore, it was necessary to develop an ink-following material that would exhibit stable tracking performance. The present invention aims to provide a liquid containment member for an applicator that can improve the performance of the ink-following body and suppress leakage and backflow phenomena of the ink-following body. [Means for solving the problem]

[0009] The liquid containment member for an applicator according to the present invention is characterized by comprising a liquid containment tube made of a paper substrate and an ink-following body having a yield strength of 16 Pa or more, which is filled into the liquid containment tube. The ink-following body preferably has a phase angle of 35° or more when the shear strain amplitude is 0-30% at 25°C and 1Hz. It is preferable that the refill is made of paper for writing instruments. [Effects of the Invention]

[0010] In this invention, the yield stress of the ink-following body is set to 16 Pa or higher, and preferably the phase angle at which the shear strain amplitude is 0-30% at 25°C and 1 Hz is 35° or higher. By filling a liquid-containing tube made of paper substrate with the ink-following body, leakage and reversal of the ink-following body can be suppressed even when the applicator is placed upright after being mounted on it. [Brief explanation of the drawing]

[0011] [Figure 1]FIG. 1 is a diagram showing one form of a refill including a liquid storage member for an applicator according to the present invention. FIG. 1(a) is a front view of the appearance of the refill, and FIG. 1(b) is a cross-sectional view taken along line A-A of the refill. [Figure 2] FIG. 2 is a diagram showing a three-layer structure of an inner layer, an intermediate layer, and an outer layer constituting a liquid storage member for an applicator according to the present invention. FIG. 2(a) shows a form having an adhesive layer between the inner layer and the intermediate layer, FIG. 2(b) shows a form having an adhesive layer between the intermediate layer and the outer layer, and FIG. 2(c) is a diagram showing a form having an adhesive layer between the inner layer, the intermediate layer, and the outer layer. MODE FOR CARRYING OUT THE INVENTION

[0012] [Liquid storage member for applicator] The liquid storage member for an applicator of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing an example of the configuration of a refill including a liquid storage member 10 for an applicator according to the present invention. FIG. 1(a) shows a front view of the appearance of the refill, and FIG. 1(b) shows a cross-sectional view taken along line A-A of the refill. In FIG. 1, for example, the refill housed in the shaft cylinder of a ballpoint pen is a liquid storage member 10 for an applicator (hereinafter also simply referred to as "liquid storage member 10"), which is a long and thin cylindrical ink storage tube having paper as a base material and storing ink (not shown), a joint 11 attached to the tip of this liquid storage member 10, and a ballpoint pen tip 12 attached to the tip of the joint 11 as a writing member.

[0013] Specifically, the joint 11 is formed with a cylindrical rear end portion that joins with the liquid storage member 10 and a cylindrical front end portion having an outer diameter larger than that of the rear end portion. The ballpoint pen tip 12 is attached to this front end portion. Further, an adhesive is applied in advance to the joint portion of the rear end portion of the joint 11 with the liquid storage member 10 to have a certain bonding strength. In this state, the rear end portion of the joint 11 is press-fitted into the inside of the tip of the liquid storage member 10, thereby joining the joint 11 and the liquid storage member 10. As a result, the liquid storage member 10 and the ballpoint pen tip 12 are connected via the joint 11 so that ink can flow through.

[0014] The liquid containment member 10 comprises a liquid containment tube made of a paper substrate and an ink-following body filled in the liquid containment tube, the ink-following body having a yield strength of 19 Pa or more. [Ink-following body] I will now explain the ink-following mechanism in detail. The ink follower can be any non-water-soluble, non-volatile organic substance with a yield strength of 16 Pa or higher. Specifically, a non-water-soluble, non-volatile organic substance with a yield strength of 16 Pa or higher is used, mainly composed of a base oil and containing thickeners, surfactants, and antioxidants.

[0015] The aforementioned base oil is the main component of the ink follower and includes mineral oil, poly-alpha-olefin (PAO), polybutene, and silicone oil. Mineral oil is derived from petroleum and is also known as mineral oil, petrolatum, paraffin, or liquid paraffin. Commercially available mineral oils include, for example, Diana Process Oil PW-90, PW-150, PW-380, and NR-26 (manufactured by Idemitsu Kosan Co., Ltd.), and Barrel Process Oil B-05 and P-2200 (manufactured by Matsumura Petroleum Co., Ltd.).

[0016] Poly-alpha-olefins (PAOs) are synthetic oils obtained by polymerizing alpha-olefins. The alpha-olefin, which is a terminal alkene, acts as the reaction initiation site, forming a branched structure within the molecule. Because this branched structure contributes to flexibility, the viscosity and viscoelasticity of the ink follower can be adjusted by appropriately selecting the alpha-olefin. Examples of alpha-olefins include ethylene, propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene.

[0017] From the perspective of maintaining the performance of the coating tool over the long term, polybutene with a number-average molecular weight of 600 or more, which is non-volatile, is used. Specifically, commercially available products such as Nissan Polybutene 200N (manufactured by NOF Corporation), Polybutene 30N (manufactured by NOF Corporation), Polybutene 015N (manufactured by NOF Corporation), Polybutene HV-15 (manufactured by Shin Nippon Chemical Co., Ltd.), and 35R (manufactured by Idemitsu Kosan Co., Ltd.) are used.

[0018] Commercially available silicone oils such as KF-54 (manufactured by Shin-Etsu Chemical Co., Ltd.), KF-96 (manufactured by Shin-Etsu Chemical Co., Ltd.), TSF451 series, TSF456 series, and TSF458 series (all manufactured by GE Toshiba Silicone Co., Ltd.) can be used.

[0019] These base oils have a kinematic viscosity of 1 to 30,000 mmHg at 40°C, in accordance with JIS K2283:2000. 2 It is / s. These base oils may be used individually or in combination of two or more, and the amount used is 70 to 99.8% by weight, preferably 85 to 99.5% by weight, relative to the total amount of the ink-following body.

[0020] In addition to the base oil, the ink-following material contains appropriate amounts of thickeners, surfactants, and antioxidants. Thickeners are added during the manufacturing of grease and are components that disperse as fine solids in the base oil, giving it semi-solid properties. Thickeners have an affinity for the base oil and create a three-dimensional network structure that contains the base oil, thereby keeping the ink-following material stationary. When shear is applied, this network breaks down and softens, giving the material the ability to soften, and also acting on viscoelasticity.

[0021] Thickeners are classified into soap-type and non-soap-type (inorganic and organic). Soap-type thickeners include calcium soap, lithium soap, lithium complex soap, and aluminum complex soap. Non-soap-type (inorganic) thickeners include silica gel and organic bentonite, while non-soap-type (organic) thickeners include polytetrafluoroethylene (PTFE), polyurea, and sodium terephthalate. Commercially available thickeners include DYNARON 6200P (olefin crystal / ethylenebutylene / olefin crystal block copolymer; manufactured by JSR Corporation), DYNARON 8300P (styrene / ethylenebutylene / styrene block copolymer; manufactured by JSR Corporation), lithium stearate (manufactured by Kawamura Chemical Industries, Ltd.), AEROSIL R202 (manufactured by Nippon Aerosil Co., Ltd.), and AEROSIL R974 (manufactured by Nippon Aerosil Co., Ltd.). When these additives are used, the amount added will vary depending on the heating, stirring, or heating and kneading conditions during the manufacture of the ink follower, but it is usually about 0.2 to 30%, preferably 0.5 to 15%, relative to the total amount of the ink follower.

[0022] These thickeners can be used individually or in combination of two or more types, and their total amount (A) should be sufficient to make the ink follower semi-solid, with an A / B ratio of approximately 0.2 to 30.0, preferably 1.0 to 10.0, relative to the amount of base oil (B).

[0023] The ink-following body may contain other components such as surfactants and antioxidants. Surfactants and antioxidants are added while adjusting the phase angle that exhibits the viscoelasticity of the ink follower.

[0024] The yield stress of the ink-following material in this invention is 16 Pa or higher, preferably 16 to 100 Pa, and more preferably 16 to 50 Pa. The yield stress is the limiting stress at which, when an external force above a certain level is applied to the ink-following material, a flow occurs rapidly, transitioning from elastic deformation to fluid deformation. In other words, the ink-following material in this invention behaves like a solid and does not flow under small stresses below 16 Pa, but it does flow at stresses of 16 Pa or higher.

[0025] It is preferable that the phase angle is 35° or greater when the shear strain amplitude at 25°C and 1Hz is 0-30%. Shear strain is a type of dynamic viscoelasticity, and it measures the shear deformation of an ink-following body. Shear deformation is measured as the ratio of the deformation of the strain in the gap between the flat sample and the measuring platform. Specifically, the ink-following body, which is the sample, is made into a flat plate and placed on the measuring platform, and a load is applied to hold it in place without sagging. In this state, a vibrator connected to the sample via an axis is driven to apply dynamic stress to the sample. When dynamic stress is applied to the sample as a stimulus by driving the vibrator, dynamic strain is generated in the sample in response. When the dynamic stress and dynamic strain are converted into electrical signals from their respective detectors and output, two waveforms (phases) are aligned on the time axis. The ratio of the stress peak value to the strain peak value of the waveform is taken as the shear strain, and the phase angle (°) at a shear strain amplitude of 0 to 30% is determined. The phase angle represents how much the sample's response lags behind the application of strain.

[0026] When the phase angle is 35° or greater when the shear strain amplitude at 25°C and 1Hz is between 0 and 30%, the ink-following material exhibits excellent tracking and impact resistance. On the other hand, if the phase angle is less than 35°, the ink-following material becomes sufficiently viscous (gelled) and loses its fluidity, but its impact resistance is poor. The ink-following body has a phase angle of more preferably 35 to 80° when the shear strain amplitude at 25°C and 1Hz is 0 to 30%.

[0027] The characteristics of the ink-following material can be optimized by selecting the type and amount of base oil and thickener used, as well as by selecting the manufacturing conditions.

[0028] The ink-following material is manufactured by heating, stirring, or kneading a base oil, thickener, and other components. The heating time and the number of stirring / kneading cycles are adjusted as appropriate depending on the type of base oil, thickener, etc., and the required viscoelasticity. The viscoelasticity of the obtained ink-following material may be further adjusted by re-kneading or heating it in a disperser such as a roll mill or kneader.

[0029] [Liquid container made from paper substrate] Next, we will explain in detail about liquid storage tubes using paper substrates. After filling a liquid container tube made of paper substrate (hereinafter simply referred to as "liquid container tube") with ink, the ink-following body is filled into the rear end of the ink. The ink can be any known aqueous or oil-based coating liquid without particular limitation.

[0030] The liquid containment tube has at least three layers: an inner layer 1 that comes into contact with the liquid, an intermediate layer 2, and an outer layer 3. At least one of the layers between the inner layer 1 and the intermediate layer 2, and between the intermediate layer 2 and the outer layer 3, is provided with an adhesive layer 5 containing polyolefin resin (hereinafter simply referred to as "adhesive layer 5"). Figure 2c shows a configuration in which adhesive layers 5 are provided both between the inner layer 1 and the intermediate layer 2, and between the intermediate layer 2 and the outer layer 3. In this three-layer structure, the inner layer 1 and the intermediate layer 2 are paper substrate laminates, which are composite materials in which a metal layer or a silica vapor-deposited layer is laminated on the surface of a paper substrate. As described above, the adhesive layer 5 may be interposed in the paper substrate laminate.

[0031] Various known paper materials can be used as the paper substrate constituting the inner layer 1, including high-quality paper, medium-quality paper, glossy paper on one side, kraft paper, glossy kraft paper on one side, bleached kraft paper, cardboard, white cardboard, liner, lightly coated paper, coated paper, art paper, cast coated paper, glassine paper, parchment paper, and vulcanized fiber. The density of these paper substrates is 0.8 g / cm³. 3Preferably, 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 substrate constituting the inner layer 1 is glassine paper, parchment paper, or vulcanized fiber, with a density of 0.8 g / cm³. 3 It is preferable if the above conditions are met.

[0032] 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 as the paper base material that makes up the inner layer 1, 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.

[0033] 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, using parchment paper and vulcanized fiber as the paper substrate constituting the inner layer 1 can effectively suppress the generation of paper dust.

[0034] Parchment paper has a basis weight of, for example, 20-100 g / m². 2 Preferably, the oil absorption rate is 13 g / m² when mineral oil is used instead of water in accordance with the Cobb method for testing the water absorption of paper and cardboard. 2 The parchment paper used should have enhanced oil resistance as follows: The thickness of the parchment paper is usually 20 to 100 μm, preferably 20 to 60 μm.

[0035] Vulcanized fiber can be made thicker than parchment paper due to differences in reactivity during the manufacturing process. Therefore, it is suitable when cardboard is required as the paper base material. Considering the compressive strength of the paper tube part after forming the liquid storage tube and the ease of handling during manufacturing, the thickness of vulcanized fiber is usually 0.08 - 1 mm, preferably 0.1 - 0.5 mm. Also, the density of vulcanized fiber is higher than that of general paper tube base paper and is usually 0.8 - 1.4 g / cm 3 However, in the present invention, considering the strength and availability of the paper tube part, it is preferably 0.8 - 1.3 g / cm 3 .

[0036] In addition, the parchment paper and 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 when these papers are used as the paper base material constituting the inner layer 1, the generation of paper powder can be suppressed.

[0037] The intermediate layer 2 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 base material with an adhesive containing a polyolefin resin, or by electron beam evaporation of aluminum, or an alloy of aluminum and zinc, etc. under vacuum.

[0038] Here, the adhesive containing a polyolefin resin used in the present invention will be described. The adhesive containing a polyolefin resin may be an adhesive composed of one or more polyolefin resins, or an adhesive obtained by mixing the polyolefin resin and other resins, etc.

[0039] 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.

[0040] Other resins that can be used 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.

[0041] 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.

[0042] The adhesive containing polyolefin resin according to the present invention is used in the form of a dispersion-type or emulsion-type resin liquid, with a polyolefin resin or a mixture of polyolefin resins and other resins as the base polymer. Additives such as silane coupling agents may be added to the resin liquid as needed. Among these, dispersion-type adhesives such as polypropylene ionomer and maleic anhydride-modified polypropylene are preferred due to their excellent adhesive properties and handling characteristics.

[0043] The adhesive containing polyolefin resin is applied to at least one of the spaces between the inner layer 1 and the intermediate layer 2, and between the intermediate layer 2 and the outer layer 3. That is, as shown in Figure 2, an adhesive layer 5 may be provided between the inner layer 1 and the intermediate layer 2 (Figure 2a), or between the intermediate layer 2 and the outer layer 3 (Figure 2b), or both between the inner layer 1 and the intermediate layer 2, and between the intermediate layer 2 and the outer layer 3 (Figure 2c). By applying an adhesive containing polyolefin resin, which has excellent adhesion to paper material and ink resistance, the layers of the liquid storage tube are tightly sealed between the inner layer 1, the intermediate layer 2, and the outer layer 3, preventing ink from leaking to the outside of the liquid storage tube. Note that ink resistance refers to the degree to which the elution of the adhesive resin component into the ink can be suppressed. When an adhesive containing polyolefin resin is used, the low compatibility with ink prevents the polyolefin resin from dissolving into the ink, and these effects on ink resistance can be expected.

[0044] In this invention, the inner layer 1, intermediate layer 2, and outer layer 3 may be bonded together with an adhesive containing polyolefin resin, and other adhesives, such as vinyl acetate resin-based, acrylic resin-based, and polyvinyl alcohol-based general-purpose adhesives, may also be used in combination.

[0045] The adhesive containing polyolefin resin is applied in a raised manner near the center of either the inner layer 1 or the intermediate layer 2. Then, while pressing the inner layer 1 and the intermediate layer 2 together, the adhesive is spread over the entire bonding surface, ensuring that no air bubbles remain in the bonding area and that there are no bonding defects. After bonding the inner layer 1 and the intermediate layer 2 together, pressure is applied to fix them in place until the adhesive hardens.

[0046] For inner layer 1 or intermediate layer 2, the adhesive containing polyolefin resin should be 5-50 g / m². 2 Degree, preferably 5-25 g / m 2 Apply in this amount.

[0047] The inner layer 1 and intermediate layer 2 of the liquid storage tube may all be formed from a paper substrate laminate using a paper substrate and a metal layer or silica vapor-deposited layer of the same thickness, or they may be formed by appropriately combining paper substrate laminates using paper substrates and metal layers or silica vapor-deposited layers of different thicknesses. In paper-based laminates, the ratio of the thickness of the paper substrate to the thickness of the metal layer or silica vapor-deposited layer is approximately 1 / 2 to 1 / 1200.

[0048] After the intermediate layer 2 is firmly attached to the inner layer 1, a paper substrate laminate, which is a strip-shaped sheet, is obtained by cutting it into strips of 4 to 20 mm in width using a bobbin slitter or the like. Next, the paper substrate laminate is wound spirally around a mandrel (paper tube manufacturing machine) with the inner layer 1 on the inside. It is preferable to either treat the surface of the mandrel with an appropriate lubricant beforehand after forming the inner layer 1, intermediate layer 2, and outer layer 3, in order to facilitate the removal of the mandrel, or to apply an appropriate amount of lubricant to the side of the inner layer 1 (paper substrate) that is wound around the mandrel. After that, an adhesive such as an adhesive containing polyolefin resin is applied to the outer intermediate layer 2 in order to bond the outer layer 3.

[0049] The paper substrate laminate is a strip-shaped sheet cut to a width of 4 to 20 mm, preferably 5 to 15 mm. By spiral winding such a wide paper substrate laminate, the required length of the liquid storage member 10 can be reached without winding many times, and as a result, the number of contact surfaces between the paper substrates, i.e., the number of joints 4, can be reduced, thereby suppressing leakage of the liquid stored in the liquid storage tube.

[0050] On the outside of the intermediate layer 2, a paper substrate is further wrapped spirally to form the outer layer 3. It is preferable that the outer layer 3 is also formed from a paper substrate with a width of 4 to 20 mm, specifically 6 to 15 mm. Similar to the paper substrate laminate, reducing the number of seams 4' prevents leakage of liquid from inside the liquid containment member 10. The paper substrate that makes up the outer layer 3 can be the same paper substrate that makes up the inner layer 1 described above. The outer layer 3 may be attached to the intermediate layer 2 using the adhesive containing the polyolefin resin. The method and amount of application of the adhesive containing the polyolefin resin in this case are similar to those applied to the inner layer 1 or the intermediate layer 2.

[0051] The ratio of the thicknesses (μm) of the inner layer 1, intermediate layer 2, and outer layer 3 is typically 20-60:0.025-12:50-200, and preferably 20-30:0.025-12:50-200.

[0052] As described above, the liquid storage tube according to the present invention has a structure in which a paper substrate laminate is wound spirally along the longitudinal direction of the liquid storage tube, with adjacent surfaces in contact with each other so as not to overlap. Even if adjacent surfaces overlap at the contact points between the paper substrate laminates, i.e., at the joint 4, the overlap width is limited to a maximum of 1 mm. By ensuring that the joint 4 does not overlap, or by limiting the overlap width to a maximum of 1 mm, leakage of liquid from the joint 4 can be suppressed. If the overlap width at the joint 4 exceeds 1 mm, a step will be created in the overlapping portion, which may lead to liquid leakage.

[0053] It is preferable that the outer layer 3 be wound with its adjacent surfaces in contact with each other, similar to the paper substrate laminate. The seams 4' of the outer layers 3 and the seams 4 of the paper substrate laminates are preferably spaced at least 1 mm apart along the longitudinal direction of the liquid containment member 10 and at least half the width of the paper substrate laminate or the outer layer 3, and more preferably 3 mm or more apart and at least half the width of the paper substrate laminate or the outer layer 3. Note that even if the seams 4' of the outer layers 3 overlap slightly, there is no problem of liquid leakage.

[0054] The liquid storage tube manufactured as described above is completed by forming the inner layer 1, intermediate layer 2, and outer layer 3, then removing the mandrel, cutting the cylindrical molded body to the required length for the liquid storage member 10, and drying it for several hours under appropriate temperature and humidity.

[0055] The resulting liquid-containing tube is smaller in diameter than ordinary paper tubes, with an outer diameter of typically 20 mm or less, preferably 15 mm or less, and more preferably 10 mm or less, and a lower limit of the outer diameter of typically 1 mm or more, preferably 2 mm or more. Such small-diameter liquid-containing members require strict dimensional accuracy. Therefore, the smaller the outer diameter of the liquid-containing tube, the more preferable it is to ensure that when spirally winding the paper substrate laminate and the outer layer made of paper substrate, the adjacent surfaces of the paper substrate laminate are in contact with each other and the adjacent surfaces of the outer layer made of paper substrate are in contact with each other.

[0056] The thickness of liquid storage tubes is typically 0.07 to 0.6 mm, specifically 0.2 to 0.4 mm. By setting the thickness of the liquid storage tubes within this range, a sufficient amount of liquid can be stored, and the barrier properties are improved, making it easier to suppress liquid leakage and deterioration.

[0057] [Applicator] The applicator of the present invention is not limited as long as it is equipped with the liquid-containing member 10, and may be a cotton-filled or direct-ink type writing instrument, or a cosmetic tool such as an eyeliner, mascara, or concealer, but is preferably a writing instrument. Therefore, the liquid-containing member 10 is suitable as a paper refill for a writing instrument.

[0058] In the case of writing instruments, the pen tip can be any type, such as a brush, soft tip, or hard tip. Specific examples of writing instruments include fountain pens, ballpoint pens, marking pens, felt-tip pens, correction tools, and brush pens. In this case, the ink contained in the liquid storage member 10 can be either water-based (gel) ink or oil-based ink, and depending on the type of pen, ink for ballpoint pens, pressurized ballpoint pens, or marking pens may be used. [Examples]

[0059] The present invention will be described in more detail below based on examples, but the present invention is not limited to the following examples. The liquid storage tubes used in each example and comparative example were manufactured as described below. [Manufacturing Example 1] Glassine paper with a thickness of 25 μm (basis weight 25 g / m²) 2 , density 1.0g / cm 3 A laminated paper with a total thickness of 38 μm, consisting of a 6.5 μm thick aluminum foil bonded to a polyolefin resin-containing adhesive (Chemipearl S500; manufactured by Mitsui Chemicals, Inc.), was cut to a width of 13 mm using a bobbin slitter. Using a roll-type applicator, 12 g / m² of the adhesive containing the polyolefin resin is applied to the aluminum foil side, which is the outer layer of the strip-shaped laminated paper. 2 The coating was applied, and the glassine paper was spirally wound in a single layer around the outer surface of the mandrel of the paper tube manufacturing machine (Langston), with the glassine paper facing inward. Next, coated paper (85 g / m² basis weight) with a thickness of 66 μm was cut to a width of 13 mm using a bobbin slitter. 2 ) was spirally wound in a single layer onto aluminum foil, which is the outer layer of the laminated paper. In this process, the laminated paper and coated paper were rolled so that their adjacent surfaces did not overlap, but rather butted together. Furthermore, the contact points between the laminated paper sheets and the contact points between the coated paper sheets were rolled so that they were separated by 3 mm along the longitudinal direction. The obtained spiral tube was cut to a length of 89.3 mm to obtain a paper liquid storage tube (paper tube 1) with an inner diameter of 3.8 mm.

[0060] [Manufacturing Example 2] In Manufacturing Example 1, a liquid storage tube (paper tube 2) was obtained in the same manner as in Manufacturing Example 1, except that the outer surface of the mandrel of the paper tube manufacturing machine (Langston) was spirally wound with strip-shaped laminated paper in a double layer instead of a single layer.

[0061] [Manufacturing Example 3] In manufacturing example 2, parchment paper with a thickness of 25 μm (basis weight 25 g / m²) was used as the laminating paper instead of glassine paper. 2 , density 1.0g / cm 3 A liquid storage tube (paper tube 3) was obtained in the same manner as in Manufacturing Example 2, except that a material was used which was made by bonding a 6.5 μm thick aluminum foil with an adhesive containing polyolefin resin.

[0062] [Manufacturing Example 4] In manufacturing example 2, glassine paper with a thickness of 25 μm (basis weight 25 g / m²) was used as the laminated paper. 2 , density 1.0g / cm 3 A liquid storage tube (paper tube 4) was obtained in the same manner as in Manufacturing Example 2, except that a silica vapor-deposited layer with a thickness of 0.4 μm was formed on top of the aluminum foil.

[0063] [Manufacturing Example 5] In manufacturing example 2, a liquid storage tube (paper tube 5) was obtained in the same manner as in manufacturing example 2, except that instead of butting adjacent surfaces of the coated paper together, they were rolled with a 1 mm overlap.

[0064] [Manufacturing Example 6] In manufacturing example 2, a liquid storage tube (paper tube 6) was obtained in the same manner as in manufacturing example 2, except that the gap between the contact points of the laminated paper and the contact points of the coated paper was 5 mm instead of 3 mm.

[0065] The inks used in each example and comparative example were prepared according to the following formulations. <Coating Solution 1> (Total amount 100% by mass) Spiron Violet C-RH [Manufactured by Hodogaya Chemical Co., Ltd.] 8% Spiron Yellow C-GNH [Manufactured by Hodogaya Chemical Industry Co., Ltd.] 5% Printex #35 [Manufactured by Degussa Japan Co., Ltd.] 8% Polyvinyl butyral BL-1 [Manufactured by Sekisui Chemical Co., Ltd.] 4% Polyvinyl butyral BH-3 [Manufactured by Sekisui Chemical Co., Ltd.] 0.7% Highrack 110H [Manufactured by Hitachi Chemical Co., Ltd.] 10% SOLSPERSE 28000 [Manufactured by Lubrizol Japan Co., Ltd.] 1% (Acid value: 29, weight average molecular weight: approx. 3400) Benzotriazole 0.5% 3-Methoxy-3-methyl-1-butanol 62.8%

[0066] <Coating Solution 2> (Total amount 100% by mass) FUJI RED 2510 [Manufactured by Fuji Pigment Co., Ltd.] 8% Johncryl 63J [Manufactured by BASF Japan Ltd.] 6% Xanthan gum KELSAN S [Manufactured by Sansho Co., Ltd. 0.32%] Isopropyl phosphate 0.5% Bioden S [Manufactured by Nippon Soda Co., Ltd.] 0.2% Benzotriazole 0.3% Triethanolamine 1.4% Propylene glycol 15% Ion-exchanged water 68.28%

[0067] <Coating Solution 3> (Total amount 100% by mass) Vinibran GV5651 [Manufactured by Nisshin Chemical Industry Co., Ltd.] 80% (Polyvinyl acetate emulsion; solids content 40%) Acid dye Red No. 227 0.22% Yellow No. 4 0.34% Blue No. 1 0.08% Purified water 19.36%

[0068] The ink-following bodies used in each example and comparative example were prepared as described below. The preparation method for the ink-following body used in Example 1 is shown as a representative example. As a base oil, 55.5% by mass of polybutene 015N (polybutene; manufactured by NOF Corporation) and 40.0% by mass of Diana Process Oil PW-380 (mineral oil; manufactured by Idemitsu Kosan Co., Ltd.) were mixed with 4.5% by mass of AEROSIL R202 (hydrophobic fumed silica; manufactured by Nippon Aerosil Co., Ltd.) as a thickener. The mixture was heated and kneaded using a planetary mixer and a roll mill to prepare an ink-following body. This ink-following body is referred to as ink-following body 1.

[0069] The ink-following bodies used in Examples 2-9 and Comparative Examples 1-3 were prepared using the types and amounts of base oil and thickener shown in Table 1, and under the mixing conditions shown in Table 1. These are referred to as ink-following bodies 2-12.

[0070] The evaluation methods for ink-following bodies 1 to 12 used in each example and comparative example are shown below. [Yield stress] The yield stress (τ0) is the shear stress at zero shear rate. The shear stress (τ) can be calculated from the shear rate (D) and the measured viscosity (at 25°C). The yield stress (τ0, in Pa) is the square of the intercept of a linear line plotted from the square roots of three or more shear rate-shear stress (measured values).

[0071] [Phase angle] The ink-following body (sample) was placed on a measuring platform, and a load was applied to hold the sample in place without sagging. In this state, a vibration exciter (Anton Paar Co., Ltd.; MCR-302), connected to the sample via an axis, was driven at 25°C and 1Hz to apply dynamic stress to the sample. The ratio of the stress peak value to the strain peak value in the two waveforms (phases) converted from the dynamic stress and dynamic strain was defined as the shear strain, and the phase angles (°) for shear strain amplitudes of 10%, 25%, and 45% were determined. Table 1 shows the phase angles (°) for shear strain amplitudes of 10%, 25%, and 45% at 25°C and 1 Hz for the ink-following bodies used in Examples 1-7 and Comparative Examples 1-3.

[0072] [Backflow of ink-following body] (i) Backflow of the ink follower when not written on. A refill was created by filling a paper liquid container tube with ink and an ink-following material, and combining it with a pen tip consisting of a connector and a ball diameter of 0.7 mm. The refill was left standing at 25°C for one week with the pen tip facing upwards. After writing, the refill was cut along its length, and backflow was determined by visually evaluating the amount of ink leakage from the rear end of the refill according to the following criteria. A: Neither the ink nor the ink tracker had moved. B: The ink-following unit was moving. C: Ink-following material was leaking from the rear end of the refill.

[0073] (ii) Backflow of the ink follower after writing In the same manner as in (i) above, after preparing the refill, spiral writing was performed using a writing test machine in a 25°C, 65% humidity environment with a load of 100g, a writing speed of 4.5m / min, and a writing angle of 60°. This was continued until the total weight of ink consumed, measured every 100m, reached 1.5 times or more the filled weight of the ink-following body. After writing, the pen was left standing at 25°C for one week with the nib facing upwards. Backflow was judged using the same criteria as in (i) above. A: Neither the ink nor the ink tracker had moved. B: The ink-following unit was moving. C: Ink-following material was leaking from the rear end of the refill.

[0074] [Example 1] 0.7g of coating liquid 1 was filled into paper tube 1, and then an ink-following body 1 was filled to a length of approximately 10mm. After measuring the filled weight, the rear end of the coating liquid was sealed. Next, a stainless steel fitting was attached to the opposite side of the sealing portion of the paper tube 1, and a pen tip consisting of a 0.7 mm ball diameter tip was attached to the tip of the fitting to create a refill. The resulting refills (unwritten and written) were left standing at 25°C for one week with the pen tips facing upwards.

[0075] [Example 2] 0.7 g of coating liquid 1 was filled into the paper tube 2, and then the ink-following body 2 was filled to a length of approximately 10 mm. After measuring the filled weight, the rear end of the coating liquid was sealed. A refill was prepared in the same manner as in Example 1. The sample was left to stand under the same conditions as in Example 1.

[0076] [Example 3] 0.7 g of coating liquid 1 was filled into paper tube 2, and then ink-following body 3 was filled to a length of approximately 10 mm. After measuring the filled weight, the rear end of the coating liquid was sealed. A refill was prepared in the same manner as in Example 1. The sample was left to stand under the same conditions as in Example 1.

[0077] [Example 4] 0.7 g of coating liquid 1 was filled into the paper tube 3, and then an ink-following body 4 was filled to a length of approximately 10 mm. After measuring the filled weight, the rear end of the coating liquid was sealed. A refill was prepared in the same manner as in Example 1. The sample was left to stand under the same conditions as in Example 1.

[0078] [Example 5] 0.7 g of coating liquid 2 was filled into the paper tube 4, and then an ink-following body 5 was filled to a length of approximately 10 mm. After measuring the filled weight, the rear end of the coating liquid was sealed. A refill was prepared in the same manner as in Example 1. The sample was left to stand under the same conditions as in Example 1.

[0079] [Example 6] 0.7 g of coating liquid 2 was filled into the paper tube 5, and then an ink-following body 6 was filled to a length of approximately 10 mm. After measuring the filled weight, the rear end of the coating liquid was sealed. A refill was prepared in the same manner as in Example 1. The sample was left to stand under the same conditions as in Example 1.

[0080] [Example 7] 0.7 g of coating liquid 3 was filled into the paper tube 6, and then an ink-following body 7 was filled to a length of approximately 10 mm. After measuring the filled weight, the rear end of the coating liquid was sealed. A refill was prepared in the same manner as in Example 1. The sample was left to stand under the same conditions as in Example 1.

[0081] [Example 8] 0.7 g of coating liquid 1 was filled into paper tube 1, and then an ink-following body 8 was filled to a length of approximately 10 mm. After measuring the filled weight, the rear end of the coating liquid was sealed. A refill was prepared in the same manner as in Example 1. The sample was left to stand under the same conditions as in Example 1.

[0082] [Example 9] 0.7 g of coating liquid 2 was filled into the paper tube 2, and then an ink-following body 9 was filled to a length of approximately 10 mm. After measuring the filled weight, the rear end of the coating liquid was sealed. A refill was prepared in the same manner as in Example 1. The sample was left to stand under the same conditions as in Example 1.

[0083] Ink-following bodies 1-7 all exhibited high yield stress, and in the backflow evaluation of the ink-following bodies, they all received an A rating both before and after writing. The results are shown in Table 1.

[0084] [Comparative Example 1] In Example 2, a refill was prepared in the same manner as in Example 2, except that an ink-following body 10 was used instead of an ink-following body 2. In Comparative Example 1, which used ink follower 8 with a higher proportion of polybutene and a lower proportion of thickener compared to ink follower 2, the yield stress was low at 9 Pa, and leakage of the ink follower was observed in the backflow evaluation of the ink follower, resulting in a C rating in both cases. The results are shown in Table 1.

[0085] [Comparative Example 2] In Example 5, a refill was prepared in the same manner as in Example 5, except that an ink-following body 11 was used instead of the ink-following body 5. In Comparative Example 1, which used ink follower 11 with a larger amount of silicone oil and a smaller amount of thickener compared to ink follower 5, the yield stress was low at 12 Pa, and leakage of the ink follower was observed in the backflow evaluation of the ink follower, resulting in a C rating in both cases. The results are shown in Table 1.

[0086] [Comparative Example 3] In Example 7, a refill was prepared in the same manner as in Example 7, except that an ink-following body 12 was used instead of an ink-following body 7. In Comparative Example 3, which used ink-following material 12 with a larger base oil content and a smaller thickener content compared to ink-following material 7, the yield stress was low at 15 Pa. In the backflow evaluation of the ink-following material, it was rated B before writing, but C after writing. The results are shown in Table 1.

[0087] [Table 1] [Explanation of Symbols]

[0088] 10 Liquid container for applicator 11 Fittings 12 ballpoint pen tips 1. Inner layer 2. Middle class 3 Outer layer 4, 4' seam 5 Adhesive layer

Claims

1. A liquid container having at least an inner layer that comes into contact with a liquid, an intermediate layer, and an outer layer, wherein the inner layer that comes into contact with the liquid is made of a paper substrate, An ink-following body having a yield strength of 16 Pa or more and 98 Pa or less is filled into the liquid-containing tube. Equipped with, The liquid container for an applicator is characterized in that the ink-following body contains 70 to 99.8% by weight of a base oil having a kinematic viscosity of 1 to 30,000 mm² / s at 40°C in accordance with JIS K2283:2000.

2. The liquid container for an applicator according to claim 1, wherein the ink-following body has a phase angle of 35° or more when the shear strain amplitude at 25°C and 1 Hz is 0 to 30%.

3. A liquid container for an applicator according to claim 1 or 2, which is a paper refill for a writing instrument.

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