Refill for writing instrument

Abstract

To provide a refill for a writing instrument capable of reducing the amount of work due to the use of an adhesive while maintaining the joint strength of a joint part between a joint and an ink storage tube.SOLUTION: A refill 10 according to the present invention is configured such that a ballpoint pen tip 11 and an ink storage tube 12 are connected via a joint 13. Further, the joint 13 is continuously provided with a joint portion 21 formed into a substantially cylindrical shape as a portion to be joined to the ink storage tube 12, a collar portion 23 with an adhesive receiving portion 22 having an outer diameter larger than that of the joint portion 21 and having a space capable of accommodating excess adhesive, and a cylindrical portion 24 having an outer diameter smaller than that of the collar portion 23 and having a substantially cylindrical shape up to the tip.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a refill for a writing instrument that includes paper as a substrate. [Background technology]

[0002] A ballpoint pen refill is formed by attaching one end (tip) of an ink reservoir to a joint (joint) that supports the ballpoint pen tip, and is used while housed inside the barrel of the ballpoint pen. Furthermore, transparent or translucent plastics such as polypropylene have traditionally been used for the ink reservoir to ensure ease of molding and visibility of the ink level.

[0003] On the other hand, in recent years, the problem of microplastics leaking into the ocean has been attracting attention, and there is growing momentum to address global environmental issues, such as by reducing the use of disposable plastics.

[0004] The problem of microplastics leaking into the ocean is also an issue that needs to be resolved for writing implements that contain resin materials, and as a solution, the use of paper materials, for example, is being considered in order to eliminate plastic.

[0005] For example, Patent Document 1 below discloses an ink reservoir for a writing instrument that uses an environmentally friendly ink reservoir. Specifically, the ink reservoir is made of a composite material in which another material is laminated onto a paper base material, and one end of the ink reservoir is joined to a connection part formed on the writing instrument or on a relay part that supports the writing instrument, thereby forming the ink reservoir for the writing instrument.

[0006] Furthermore, Patent Document 2 below discloses a liquid containing member in which an ink containing tube molded from plastic such as polypropylene is replaced with a material containing a paper base material, thereby reducing the amount of plastic used and the impact on the environment. Specifically, this liquid containing member has at least three layers consisting of a paper base laminate including an inner layer of a paper base material and an intermediate layer which is a metal layer or a silica vapor deposition layer formed on the outer peripheral surface of the inner layer, and an outer layer of the paper base material formed on the outer peripheral surface of the intermediate layer, and the density of the paper base material of the inner layer is 0.8 g / cm 3 The present invention is characterized in that: [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2020-172044 [Patent Document 2] Patent Publication No. 2021-16976 Summary of the Invention [Problem to be solved by the invention]

[0008] On the other hand, in the above prior art, ballpoint pen refills are formed by press-fitting and joining a fitting into the tip of an ink reservoir tube. In order to ensure a certain level of joining strength at this joint, it is desirable to apply adhesive to the rear end of the fitting where the fitting and the ink reservoir tube come into contact before joining, and then press-fit the rear end of the fitting into the tip of the ink reservoir tube in this state.

[0009] Furthermore, in the above-mentioned prior art, in the process of press-fitting the joint into the tip of the ink containing tube, for example, as shown in Figure 10, the tip of the ink containing tube is pushed in until it abuts against the locking flange provided on the joint.

[0010] However, while forming a ballpoint pen refill using the above process can provide a certain level of bonding strength, if too much adhesive is applied, for example, the adhesive may be pushed out by the pressure and spill out of the refill. This results in the need for work outside of the actual manufacturing process during the process of manufacturing ballpoint pen refills, such as checking the condition of the adhesive and, if an abnormality such as adhesive leaking out is discovered during the checking work, repairing the problem.

[0011] The present invention has been made to solve the above-mentioned problems, and aims to provide a refill for a writing instrument that can reduce the amount of work required by using adhesive while maintaining the bonding strength of the joint between the fitting and the ink reservoir tube. [Means for solving the problem]

[0012] The writing instrument refill of the present invention is characterized in that the writing member and the ink reservoir are connected via a joint, and the joint includes, for example, a joint formed as a portion to be joined to the ink reservoir, and a flange formed with an adhesive receiver having an outer diameter larger than that of the joint and a space capable of receiving excess adhesive. The joint, on which adhesive has been applied in advance, is press-fitted into the tip of the ink reservoir, and the ink reservoir and the joint are joined together with a space between the tip of the ink reservoir and the bottom of the adhesive receiver.

[0013] With this configuration, any excess adhesive that is pushed away by the ink reservoir tube due to press-fitting and leaks out is sealed in the adhesive receiver formed in the flange, so that the adhesive does not adversely affect the writing instrument refill or the ballpoint pen it is stored in. In other words, in the writing instrument refill of the present invention, the adhesive provides a certain level of bond strength at the joint between the fitting and the ink reservoir tube, while eliminating the need for repair work when adhesive leaks out, which has been a problem in the past.

[0014] Furthermore, it is desirable that the writing instrument refill according to the present invention has a step inside the adhesive receiver that has a locking surface formed at a fixed height from the bottom surface of the adhesive receiver and that contacts the outer circumferential surface of the joint at that fixed height, so that the tip of the ink reservoir that has been pressed into the adhesive receiver by press-fitting is locked by the locking surface formed on the step. This makes it possible to keep the joint position between the ink reservoir and the joint constant.

[0015] Furthermore, in a writing instrument refill according to the present invention, a writing member and an ink reservoir are connected via a joint, and the joint, for example, is configured to include a joint formed as a portion that joins with the ink reservoir and a flange formed with an outer diameter larger than the joint. The flange is also configured to include a through-hole that allows excess adhesive to flow to the outside to prevent it from accumulating, and a groove into which the ink reservoir can be fitted to allow excess adhesive to flow into the through-hole. The joint, which has adhesive pre-applied, is then press-fitted into the tip of the ink reservoir, and the tip of the ink reservoir is then further inserted into the groove and pushed near the bottom of the groove, leaving a space between the tip of the ink reservoir and the bottom of the groove, and the ink reservoir and the joint are then joined.

[0016] With this configuration, excess adhesive that is swept away by the ink reservoir tube due to the press-fitting is swept into the groove, and any excess adhesive that has nowhere to go in the groove due to the fitting is discharged through the through-hole, so that the adhesive does not adversely affect the writing instrument refill or the ballpoint pen that the writing instrument refill is stored in. In other words, in the writing instrument refill according to the present invention, the adhesive provides a certain level of bond strength at the joint between the fitting and the ink reservoir tube, while eliminating the need for repair work if the adhesive leaks out, which has been a problem in the past.

[0017] In addition, in the writing instrument refill according to the present invention, it is preferable that the joint contains calcium carbonate or a biomass-derived polyolefin, and that the adhesive is a low-temperature curing one-component adhesive. [Effects of the Invention]

[0018] According to the writing instrument packaging of the present invention, the adhesive effect is such that the strength of the joint between the fitting and the ink reservoir tube is maintained, while the amount of work required to use the adhesive can be reduced compared to conventional methods. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 shows an example of the configuration of a first embodiment of a writing instrument refill according to the present invention, where (a) shows a front view of the appearance of the refill housed in a ballpoint pen, (b) shows a cross-sectional view of the refill, and (c) shows an enlarged cross-sectional view of the dotted line portion in (b). [Figure 2] FIG. 2 shows an example of the configuration of a first embodiment of a writing instrument refill according to the present invention, with (a) and (b) showing perspective views of the refill. [Figure 3] FIG. 3 shows an example of the configuration of a joint used in the refill of the first embodiment, where (a) is a front oblique view, (b) is a rear oblique view, (c) is a bottom view, (d) is a plan view, (e) is a front view, and (f) is a front cross-sectional view. [Figure 4] Figure 4 shows an example of the configuration of a second embodiment of a writing instrument refill according to the present invention, where (a) shows a front view of the refill's appearance housed in a ballpoint pen, (b) shows a side view of the refill's appearance, (c) shows a side cross-sectional view of the refill, and (d) shows an enlarged cross-sectional view of the dotted line portion in (c). [Figure 5] FIG. 5 shows an example of the configuration of a second embodiment of a writing instrument refill according to the present invention, with (a) and (b) showing perspective views of the refill. [Figure 6] Figure 6 shows an example of the configuration of a joint used in the refill of the second embodiment, where (a) is a front oblique view, (b) is a rear oblique view, (c) is a bottom view, (d) is a plan view, (e) is a side view, (f) is a side cross-sectional view, (g) is a front view, and (h) is a front cross-sectional view. [Figure 7]Figure 7 shows an example of the configuration of a third embodiment of a writing instrument refill according to the present invention, where (a) shows a front view of the appearance of the refill housed in a ballpoint pen, (b) shows a plan view of the appearance of the refill, (c) shows an AA cross-sectional view (side cross-sectional view) of the refill, (d) shows a BB cross-sectional view of the refill, (e) shows an enlarged cross-sectional view of the dotted line portion of (c), and (f) shows an enlarged cross-sectional view of the dotted line portion of (d). [Figure 8] FIG. 8 shows an example of the configuration of a third embodiment of a writing instrument refill according to the present invention, with (a) and (b) showing perspective views of the refill. [Figure 9] Figure 9 shows an example of the configuration of a joint used in the refill of the third embodiment, where (a) is a front oblique view, (b) is a rear oblique view, (c) is a bottom view, (d) is a plan view, (e) is a front view, (f) is an AA cross-sectional view, and (g) is a BB cross-sectional view. [Figure 10] FIG. 10 is a diagram showing a conventional refill. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of a writing instrument refill according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to this embodiment. Furthermore, in the specification and drawings of this application, elements that can be similarly described may be designated by the same reference numerals to avoid redundant description.

[0021] First Embodiment A first embodiment of a writing instrument refill according to the present invention will be described in detail with reference to the drawings.

[0022] Figures 1 and 2 show an example of the configuration of a first embodiment of a writing instrument refill according to the present invention, where Figure 1(a) shows a front view of the appearance of the refill housed in a ballpoint pen, Figure 1(b) shows a cross-sectional view of this refill, Figure 1(c) shows an enlarged cross-sectional view of the dotted line portion in Figure 1(b), and Figures 2(a) and (b) show oblique views of this refill.

[0023] <Overall structure> Generally, a ballpoint pen has a generally cylindrical barrel, and stores, for example, the refill 10 of this embodiment in the barrel. A tapered tip barrel that tapers toward the tip is screwed onto the tip of the barrel, and a ballpoint pen tip 11, which is part of the refill 10, protrudes from the tip of the tip barrel.

[0024] 1, the refill 10 housed in the ballpoint pen as described above includes, for example, a long, thin, cylindrical ink reservoir 12 containing paper as a base material and containing ink (not shown), a joint 13 attached to the tip of the ink reservoir 12, and a ballpoint pen tip 11 attached to the tip of the joint 13. In other words, the ballpoint pen tip 11 and the ink reservoir 12 are connected via the joint 13.

[0025] <Joints> Figure 3 shows an example of the configuration of the joint 13 used in the refill 10 of this embodiment, where (a) is a front oblique view, (b) is a rear oblique view, (c) is a bottom view, (d) is a plan view, (e) is a front view, and (f) is a front cross-sectional view.

[0026] As shown in Figures 3 and 1(c), the joint 13 is configured to include a joint portion 21 formed in an approximately cylindrical shape as the rear end portion that joins with the ink containing tube 12, a flange portion 23 formed with an outer diameter larger than that of the joint portion 21 and having an adhesive receiving portion 22 with a space (gap) capable of containing excess adhesive, and a cylindrical portion 24 formed in an outer diameter smaller than that of the flange portion 23 and formed in an approximately cylindrical shape all the way to the tip.

[0027] In addition, an ink circulation hole 25 is formed inside the joint 21 so that ink can flow to the ballpoint pen tip 11, and a tip insertion hole 26 is formed at the tip of the cylindrical portion 24 so that the ballpoint pen tip 11 can be inserted.

[0028] In addition, in the joint 13 having the above-described configuration, the press-fit portion 11a of the ballpoint pen tip 11 is press-fitted into the tip insertion hole 26 inside the tip, as shown in FIG. 1(c), for example. On the other hand, in the refill 10 of this embodiment, the joining portion 21 formed at the rear end of the joint 13 is press-fitted into the tip of the ink containing tube 12. At this time, the tip of the ink containing tube 12 is pushed into the adhesive receiving portion 22 by the press-fitting, but does not abut against the bottom of the adhesive receiving portion 22. In other words, the ink containing tube 12 is joined to the joining portion 21 at a position where it does not abut against the bottom of the adhesive receiving portion 22.

[0029] Furthermore, to ensure a certain level of bonding strength at the joint with the ink containing tube 12, adhesive is applied to the joint 21 of the fitting 13 before press-fitting. Then, with the adhesive applied, the joint 21 of the fitting 13 is press-fitted into the tip of the ink containing tube 12, thereby joining the fitting 13 and the ink containing tube 12. At this time, any excess adhesive that is washed away by the tip of the ink containing tube 12 and leaks out due to the press-fitting is sealed inside the adhesive receiver 22.

[0030] In this way, the refill 10 of this embodiment connects the ballpoint pen tip 11 and the ink containing tube 12 via the joint 13, and the joint 13 is configured to have, for example, a joint portion 21 formed in an approximately cylindrical shape as the part that joins with the ink containing tube 12, a flange portion 23 formed in an outer diameter larger than the joint portion 21 and having an adhesive receiving portion 22 with a space capable of containing excess adhesive, and a cylindrical portion 24 formed in an outer diameter smaller than the flange portion 23 and formed in an approximately cylindrical shape all the way to the tip.

[0031] At this time, in this embodiment, the joint portion 21, which has adhesive pre-applied thereto, is press-fitted into the tip of the ink containing tube 12. Then, the tip of the ink containing tube 12 is pushed close to the bottom of the adhesive receiving portion 22 (a position where it does not abut against the bottom), and the ink containing tube 12 and the joint portion 21 are joined at this position. In other words, the ink containing tube 12 and the joint portion 21 are joined together with a space between the tip of the ink containing tube 12 and the bottom of the adhesive receiving portion 22.

[0032] With this configuration, any excess adhesive that is swept away by the tip of the ink reservoir 12 and leaks out is contained within the adhesive receiver 22 formed in the flange 23, and the adhesive does not adversely affect the refill 10 or the ballpoint pen that contains the refill 10. In other words, in this embodiment, the adhesive provides a certain level of bonding strength to the joint between the fitting 13 and the ink reservoir 12, while eliminating the need for repair work when adhesive leaks out, which has remained a problem in the past.

[0033] The arithmetic mean roughness Ra of the surface of the inner surface portion 27 located on the outer periphery of the adhesive receiving portion 22 is preferably 1.0 μm or more. By making the arithmetic mean roughness a certain matte finish rather than a smooth finish, the adhesive can be more easily attached to the inner surface portion 27 of the joint 13, improving the adhesive strength. On the other hand, if the arithmetic mean roughness is too large, air bubbles are more likely to be generated at the interface between the inner surface portion 27 and the adhesive, reducing the adhesive strength, so it is preferable that the arithmetic mean roughness Ra be 2.0 to 4.0 μm.

[0034] The surface roughness (arithmetic mean roughness Ra) is measured by cutting out the inner surface portion 27 and measuring a single point on the surface, measuring 0.532 mm x 0.709 mm square, at intervals of 0.002 mm, using a laser microscope (Keyence Corporation: VK-X260). The smoothing conditions are: filter size 3 x 3, filter type simple average, number of runs 1, lens magnification 20x, color ultra-deep mode, and other settings conforming to the standard specifications.

[0035] In addition, in this embodiment, a refill housed in a ballpoint pen has been described as an example of a refill for a writing instrument, but the present invention is not limited to this, and can be applied to all writing instruments that contain ink, such as fountain pens, markers, brush pens, etc. In this case, the ballpoint pen tip 11 can be described as a writing member corresponding to the writing instrument.

[0036] <Suitable joint material 1> Next, suitable joint materials for the refill 10 of this embodiment will be described.

[0037] For example, in order to provide a joint with a low environmental impact, it is preferable that the mass ratio of the crystalline polymer to the inorganic fine powder or the organic fine powder is 50:50 to 20:80, preferably 48:52 to 30:70, more preferably 43:57 to 35:65, and even more preferably 41:59 to 39:61, in the resin composition.

[0038] A crystalline polymer refers to a polymer that has a melting point and has crystalline regions where the polymer is regularly arranged and irregular amorphous regions. The type of crystalline polymer is not particularly limited as long as it has crystalline regions, but examples include polyolefin resins (such as polypropylene resin and polyethylene resin), biodegradable resins, polyamide resins, polybutylene terephthalate (PBT), and polyethylene terephthalate (PET). Among these, polyolefin resins and biodegradable resins are preferred, with polypropylene resin and polyethylene resin being particularly preferred. Polyolefin resins and polyamide resins refer to resins having polyolefin or polyamide as their main chain. More specifically, for example, polypropylene resin refers to a resin having polypropylene as its main chain, and these resins may be copolymers with other resins as long as they are crystalline. For example, propylene-ethylene copolymers may be used. Biodegradable resins refer to resins that are completely consumed by microorganisms in nature and ultimately decomposed into water and carbon dioxide. Specific examples include polylactic acid, polycaprolactone, polybutylene succinate, polybutylene adipate, polyethylene succinate, cellulose ester, etc. The crystalline polymer may be one type alone or two or more types, for example, a mixture of polypropylene resin and polyethylene resin.

[0039] Examples of inorganic fine powders include calcium carbonate, titanium oxide, silica, clay, talc, kaolin, aluminum hydroxide, calcium sulfate, barium sulfate, mica, zinc oxide, dolomite, glass fiber, and hollow glass. The type of organic fine powder is not particularly limited, but examples include methyl cellulose, ethyl cellulose, polystyrene, polyacrylic acid ester, and polyvinyl acetate. Of these, calcium carbonate is preferably used as the inorganic fine powder. These may be used alone or in combination of two or more. Furthermore, to improve the dispersibility of the inorganic fine powder in the resin composition, the surface of the inorganic fine powder may be modified in advance by a conventional method.

[0040] The average particle size of the inorganic or organic fine powder is preferably 0.1 μm to 50 μm, more preferably 1.0 μm to 15 μm. The average particle size of the inorganic particles is the 50% particle size (d50) obtained from the cumulative % distribution curve measured with a laser diffraction particle size distribution analyzer. The shape of the inorganic or organic fine powder may be granular, acicular, or flat.

[0041] In addition to the crystalline polymer, inorganic fine powder, or organic fine powder, the resin composition may contain other additives such as colorants, lubricants, coupling agents, flow improvers, dispersants, antioxidants, ultraviolet absorbers, stabilizers, antistatic agents, and foaming agents. These additives may be added to the resin composition before the molding step.

[0042] Examples of lubricants include fatty acid-based lubricants such as stearic acid, hydroxystearic acid, complex stearic acid, and oleic acid; aliphatic alcohol-based lubricants; aliphatic amide-based lubricants such as stearamide, oxystearamide, oleylamide, erucylamide, ricinoleamide, behenamide, methylolamide, methylenebisstearamide, methylenebisstearobenamide, bisamic acids of higher fatty acids, and complex amides; aliphatic ester-based lubricants such as n-butyl stearate, methyl hydroxystearate, polyhydric alcohol fatty acid esters, saturated fatty acid esters, and ester waxes; and fatty acid metal soap-based lubricants.

[0043] As the antioxidant, phosphorus-based antioxidants, phenol-based antioxidants, and pentaerythritol-based antioxidants can be used. Phosphorus-based antioxidant stabilizers, more specifically phosphorus-based antioxidant stabilizers such as phosphites and phosphate esters, are preferably used. Examples of phosphites include triesters, diesters, and monoesters of phosphorous acid, such as triphenyl phosphite, trisnonylphenyl phosphite, and tris(2,4-di-tert-butylphenyl) phosphite.

[0044] Examples of phosphoric acid esters include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, tris(nonylphenyl)phosphate, 2-ethylphenyldiphenyl phosphate, etc. These phosphorus-based antioxidants may be used alone or in combination of two or more.

[0045] Examples of phenolic antioxidants include α-tocopherol, butylhydroxytoluene, sinapyl alcohol, vitamin E, n-octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenylacrylate, 2,6-di-tert-butyl-4-(N,N-dimethylaminomethyl)phenol, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl ester, and tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxymethyl]methane, and the like, which can be used alone or in combination of two or more.

[0046] <Suitable joint material 2> Another example of a suitable joint material with low environmental impact is biomass-derived polyolefin. Biomass-derived polyolefin uses biomass-derived ethylene as a raw material. Biomass-derived ethylene can be produced using biomass-derived ethanol as a raw material. In particular, it is preferable to use biomass-derived fermented ethanol obtained from plant raw materials. The plant raw material is not particularly limited, and conventionally known plants can be used. Examples include corn, sugarcane, beet, and manioc.

[0047] Biomass-derived polyolefins are produced by polymerizing monomers containing biomass-derived ethylene. When biomass-derived ethylene is used as the raw material monomer, the polymerized polyolefin is biomass-derived. Note that the raw material monomer for polyolefins does not have to contain 100% by mass of biomass-derived ethylene.

[0048] The monomers that are raw materials for biomass-derived polyolefins may further contain at least one selected from fossil fuel-derived ethylene and fossil fuel-derived α-olefins, or may further contain biomass-derived α-olefins.

[0049] The number of carbon atoms in the α-olefin is not particularly limited and is usually an integer of 3 to 20. The α-olefin is preferably butylene, hexene, or octene.

[0050] Because biomass-derived polyolefins and fossil-fuel-derived polyolefins have similar physical properties, such as molecular weight and mechanical and thermal properties, the biomass plastic content defined in ASTM D6866 is commonly used to distinguish between them. Radioactive carbon-14C exists in the atmosphere at a ratio of 1 in 1012 particles. This ratio is the same for atmospheric carbon dioxide, and therefore remains the same even in plants that fix this carbon dioxide through photosynthesis. Therefore, the carbon in biomass-derived polyolefins contains radioactive carbon-14C. In contrast, the carbon in petroleum-derived resins contains almost no radioactive carbon-14C. Therefore, the proportion of plant-derived resin in a resin, i.e., the biomass plastic content, can be determined by measuring the concentration of radioactive carbon-14C in the resin using an accelerator mass spectrometer.

[0051] The biomass plastic content of biomass-derived polyolefins is not particularly limited. From the perspective of carbon neutrality and environmental consideration, the lower limit of the biomass plastic content of biomass-derived polyolefins is preferably 80% or more. The upper limit is not particularly limited, but is usually less than 99% due to the possibility of mixing with other agents during molding. Therefore, the biomass plastic content of biomass-derived polyolefins is preferably 80% or more and less than 99%.

[0052] Suitable examples of biomass-derived polyolefins include polyethylene resins and polypropylene resins. Polyethylene resins are preferred because they can improve the recovery rate through silanol crosslinking. Polyethylene resins with a density of 0.941 g / cm are preferred. 3 High density polyethylene (HDPE), density 0.910g / cm 3 More than 0.94g / cm 3Linear low-density polyethylene resin (LLDPE) with a density of less than 0.910 g / cm 3 More than 0.940g / cm 3 Examples include low-density polyethylene resins (LDPE) of less than 1000 kJ / 1000 kcal. The melt flow rate (MFR) of the polyolefin is not particularly limited. From the viewpoint of moldability, the MFR (JIS K6922-1:1997 Appendix (190°C, 21.18 N load)) is preferably 1 g to 30 g / 10 min, more preferably 1 g to 25 g / 10 min, and even more preferably 1 g to 20 g / 10 min.

[0053] Examples of biomass-derived polyolefins that can be used include Braskem products under the product names "SHA7260" (HDPE), "SBC818" (LDPE), and "SLL118 / 21" (LLDPE).

[0054] <Suitable adhesive> Next, a suitable adhesive for the refill 10 of this embodiment will be described.

[0055] (1) A compound or a mixture of compounds containing one or more of the compounds (A) to (C) above, namely, (A) a compound containing two or more thiirane rings in the molecule, (B) a compound containing both a thiirane ring and an oxirane ring in the molecule, and (C) a compound having one or more oxirane rings but not a thiirane ring in the molecule, wherein the ratio of the number of oxirane rings to the number of thiirane rings is 40 / 60 to 10 / 90. (2) Thiol compounds having one or more thiol groups in the molecule (3) Thermal latent curing accelerator (4) Core-shell type acrylic rubber particles (5) Acidic compounds and / or boric acid esters It is preferable to use a heat-curable one-component resin composition containing the above components (1) to (5), which has excellent low-temperature fast curing properties, high adhesive strength, does not cause separation of uncured portions during heat curing, and has good storage stability (preservation stability).

[0056] (1) Resin components containing thiirane rings The thiirane ring-containing compound (A) used may be a compound containing two or more thiirane rings in the molecule. The thiirane ring-containing compound (B) may be a compound containing both one or more thiirane rings and one or more oxirane rings in the molecule. The thiirane ring-containing compound (A) or (B) may have a functional group other than the oxirane ring and the thiirane ring. Specific examples of such functional groups include a hydroxyl group, a vinyl group, an acetal group, an ester group, a carbonyl group, an amide group, and an alkoxysilyl group. The thiirane ring-containing compound (A) or (B) may be used alone or in combination of two or more.

[0057] Thiirane ring-containing compounds are prepared by a variety of methods, including thermal hydrolysis of hydroxymercaptans, treatment with weak alkaline solutions of 1,2-chlorothiols, and treatment of ethylenically unsaturated ethers with compounds such as sulfur or polysulfide dialkyls.

[0058] Specific examples of the thiirane ring-containing compound include, but are not limited to, 2,2-bis(4-(2,3-epithiopropoxy)phenyl)propane, bis(4-(2,3-epithiopropoxy)phenyl)methane, 1,6-di(2,3-epithiopropoxy)naphthalene, 1,1,1-tris-(4-(2,3-epithiopropoxy)phenyl)ethane, 2,2-bis(4-(2,3-epithiopropoxy)cyclohexyl)propane, bis(4-(2,3-epithiopropoxy)cyclohexyl)methane, 1,1,1-tris-(4-(2,3-epithiopropoxy)cyclohexyl)ethane, 2,3-epithiocyclohexyl)ether of 1,5-pentanediol, and di(3,4-epithiooctyl)ether of 1,6-hexanediol.

[0059] Compound (B) having both a thiirane ring and an oxirane ring in one molecule can be obtained by adjusting the amount of episulfidation reagent used or reaction conditions when synthesizing an episulfide resin by exchanging the oxygen atom in the epoxy ring of an epoxy compound as a raw material with a sulfur atom. It can also be obtained by mixing a partial episulfide product obtained by separation using various purification methods with a full episulfide product.

[0060] Compound (C) having one or more oxirane rings in the molecule but not containing a thiirane ring is generally called an epoxy compound. This epoxy compound may have one or more epoxy groups in the molecule. Commercially available products of this epoxy compound include, but are not limited to, monofunctional epoxy compounds such as Cardura E10P manufactured by Japan Epoxy Resins Co., Ltd., Denacol EX111, EX121, EX141, EX145, and EX146 manufactured by Nagase ChemteX Corporation, and KBM403 manufactured by Shin-Etsu Chemical Co., Ltd. Furthermore, examples of epoxy compounds having two or more epoxy groups in the molecule include, but are not limited to, Epicoat 828, 1001, 801, 806, 807, 152, 604, 630, 871, YX8000, YX8034, and YX4000 manufactured by Japan Epoxy Resins Co., Ltd.; Epiclon 830, 835LV, HP4032D, 703, 720, 726, and HP820 manufactured by Dainippon Ink Mfg. Co., Ltd.; and EP4100, EP4000, EP4080, EP4085, EP4088, EPU6, EPR4023, EPR1309, and EP49-20 manufactured by Asahi Denka Kogyo Co., Ltd.

[0061] The above-mentioned epoxy compounds may be used either alone or in combination of two or more.

[0062] Monofunctional epoxy compounds are preferably used to adjust the properties (e.g., viscosity) of the composition and the crosslink density of the cured product, while epoxy compounds having two or more functional groups are preferably added to improve heat resistance and adhesiveness.

[0063] In particular, the inclusion of a bisphenol type epoxy resin is preferred because it provides greater toughness and an excellent balance between curability and storage stability.

[0064] Each of the components (A) to (C) may have a functional group other than the oxirane ring and the thiirane ring, such as a hydroxyl group, a vinyl group, an acetal group, an ester group, a carbonyl group, an amide group, or an alkoxysilyl group.

[0065] The compounds (A) to (C) in the above composition include at least one of the following: (A) a compound containing two or more thiirane rings in its molecule; (B) a compound containing at least one thiirane ring and at least one oxirane ring in its molecule; or (C) a compound containing at least one oxirane ring in its molecule but no thiirane ring; and the ratio of the number of oxirane rings to the number of thiirane rings is 40 / 60 to 10 / 90, or a mixture of the above compounds. If the ratio of the number of thiirane rings is lower than this range, the composition will not exhibit sufficient rapid curing properties. The presence of a compound containing an oxirane ring improves the solubility of the latent curing agent, resulting in a faster curing rate.

[0066] (2) Thiol compounds with one or more thiol groups in the molecule The thiol compound to be used may be any thiol compound having one or more thiol groups in the molecule. Specific examples include 3-methoxybutyl 3-mercaptopropionate, 2-ethylhexyl 3-mercaptopropionate, tridecyl 3-mercaptopropionate, trimethylolpropane tristhiopropionate, pentaerythritol tetrakisthiopropionate, methyl thioglycolate, 2-ethylhexyl thioglycolate, ethylene glycol bisthioglycolate, 1,4-butanediol bisthioglycolate, trimethylolpropane tristhioglycolate, pentaerythritol tetrakisthioglycolate, di(2-mercaptoethyl)ether, 1-butanethiol, 1-hexanethiol, and the like. Examples of thiol compounds include, but are not limited to, cyclohexyl mercaptan, 1,4-butanedithiol, 3-mercapto-2-butanol, γ-mercaptopropyltrimethoxysilane, benzenethiol, benzyl mercaptan, 1,3,5-trimercaptomethylbenzene, 1,3,5-trimercaptomethyl-2,4,6-trimethylbenzene, polyethers containing terminal thiol groups, polythioethers containing terminal thiol groups, thiol compounds obtained by reacting an epoxy compound with hydrogen sulfide, and thiol compounds having terminal thiol groups obtained by reacting a polythiol compound with an epoxy compound.

[0067] Examples of commercially available thiol compound products include, but are not limited to, Epomate QX11, QX12, Epicure QX30, QX40, QX60, QX900, and Capcure CP3-800 manufactured by Japan Epoxy Resins Co., Ltd., OTG, EGTG, TMTG, PETG, 3-MPA, TMTP, and PETP manufactured by Yodo Chemical Co., Ltd., Thiokol LP-2 and LP-3, and Polythiol QE-340M manufactured by Toray Fine Chemical Co., Ltd., and KBM803 manufactured by Shin-Etsu Chemical Co., Ltd. These may be used alone or in combination of two or more.

[0068] In terms of storage stability, more preferred thiol compounds are those containing as few basic impurities as possible. In terms of heat resistance of the cured product, thiol compounds having two or more functional groups and thiol compounds containing an aromatic ring in the molecule are more preferred.

[0069] The amount of thiol compound to be added is not particularly limited, but it is preferably added in a range of 0.01 to 0.5 in terms of thiol equivalent ratio relative to the total of the thiirane rings and oxirane rings in the resin component described in (1) above. Adding the thiol compound within the above range can further improve the curing speed and storage stability, and also can provide a composition with an excellent balance between the strength and heat resistance of the cured product.

[0070] (3) Thermal latent curing accelerator The thermal latent curing accelerator used is a compound that has no activity toward epoxy resins at room temperature but is activated by heating through dissolution, decomposition, rearrangement reaction, or the like, and functions as an accelerator. Examples include, but are not limited to, imidazole compounds and their derivatives that are solid at room temperature, salts of various amines and acids, and solid-dispersed amine adduct-based latent curing accelerators. Furthermore, examples of solid-dispersed amine adduct-based latent curing accelerators include, but are not limited to, reaction products of amine compounds and epoxy compounds (amine-epoxy adducts) and reaction products of amine compounds and isocyanate compounds or urea compounds (urea adducts). Of these thermal latent curing accelerators, solid-dispersed amine adduct-based latent curing accelerators are preferred, and urea adduct-based latent curing accelerators are more preferred, as they exhibit excellent effects in terms of the low curing temperature and storage stability of the above-mentioned composition. The amount of these thermal latent curing accelerators to be added is not particularly limited, but is preferably added in the range of 0.1 to 30 parts by weight per 100 parts by weight of the total resin components of (1) above. If the amount of curing accelerator is too small, curing will be slow, and if it is too large, storage stability will be poor.

[0071] Examples of commercially available thermal latent curing accelerators include imidazole compounds 2PZ, 2PHZ, 2P4MHZ, C17Z, 2MZ-A, 2E4MZ-CNS, and 2MA-OK manufactured by Shikoku Chemicals Corporation; Amicure PN23, PN31, PN40J, PN-H, MY24, and MY-H manufactured by Ajinomoto Fine-Techno Co., Ltd.; EH-3293S, EH-3366S, EH-3615S, EH-4070S, EH-4342S, and EH-3731S manufactured by Asahi Denka Co., Ltd.; Novacure HX-3742 and HX-3721 manufactured by Asahi Kasei Chemicals Corporation; and FXE-1000, FXR-1030, FXR-1080, and FXR-1110 manufactured by Fuji Chemical Industry Co., Ltd., but are not limited thereto.

[0072] (4) Core-shell type acrylic rubber particles Core-shell acrylic rubber microparticles are microparticles made of a polymer whose core and shell have different properties. While many examples exist, core-shell microparticles consisting of a rubbery polymer core and a glassy polymer shell are preferred. These core-shell structured particles have "elasticity" in the core and "hardness" in the shell, and are insoluble in liquid resins. Addition of core-shell acrylic rubber microparticles imparts high adhesive strength and thermal shock resistance at low temperatures after curing, and prevents separation and uncuring.

[0073] In the production of preferred powder particles, the core portion is first produced by polymerizing a polymerizable monomer. Examples of the polymerizable monomer include (meth)acrylate monomers such as n-propyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and n-decyl (meth)acrylate; aromatic vinyl compounds such as styrene, vinyltoluene, and α-methylstyrene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; vinylidene cyanide; 2-hydroxyethyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 2-hydroxyethyl fumarate, hydroxybutyl vinyl ether, monobutyl maleate, and butoxyethyl methacrylate. Further examples include crosslinkable monomers having two or more reactive groups, such as ethylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, hexanediol tri(meth)acrylate, oligoethylene di(meth)acrylate, and oligoethylene tri(meth)acrylate; aromatic divinyl monomers such as divinylbenzene; triallyl trimellitate; and triallyl isocyanelate, and these can be used alone or in combination of two or more different types.

[0074] The rubber properties of the polymer obtained by polymerizing the polymerizable monomers vary depending on the molecular weight, molecular shape, and crosslink density. In this embodiment, the core portion must be a rubbery polymer at room temperature (e.g., 25°C). More preferably, the glass transition point of the resulting polymer is -10°C or lower.

[0075] Next, a second polymerization is performed using the polymer particles thus obtained as cores, in which a polymerizable monomer is polymerized to form a shell composed of a polymer that is glassy at room temperature. The polymerizable monomer used in this process can be selected from the same polymerizable monomers used to obtain the core. However, in this embodiment, the shell portion must be a glassy polymer at room temperature (e.g., 25°C). Preferably, the glass transition temperature of the resulting polymer is 70°C or higher. This can be determined by the molecular weight, molecular shape, crosslink density, etc. of the polymer obtained when the selected polymerizable monomer is copolymerized. If the polymer particles are not glassy at room temperature, when the present polymer particles are mixed with a liquid resin capable of radical polymerization to form a sealant composition, the particles will swell due to the radical polymerizable monomer, increasing viscosity over time during storage and resulting in gelation. In other words, storage stability will be insufficient.

[0076] Preferred examples of polymerizable monomers used as the shell material include (meth)acrylates in which the alkyl group has 1 to 4 carbon atoms, such as ethyl (meth)acrylate, n-butyl acrylate, methyl methacrylate, and butyl methacrylate. These may be used alone or in combination of two or more, with methyl methacrylate being particularly preferred.

[0077] Furthermore, the particle size of these core-shell type acrylic rubber particles is preferably in the range of 0.05 μm to 10 μm. If it is smaller than 0.05 μm, high adhesive strength cannot be obtained, and if it exceeds 10 μm, the toughness of the cured product cannot be obtained (the balance of the sea-island structure is lost).

[0078] Commercially available examples of such core-shell type acrylic rubber microparticles include F351 manufactured by Zeon Corporation, Metablen S manufactured by Mitsubishi Rayon Co., Ltd., and Staphyloid manufactured by Ganz Chemical Co., Ltd. (all trade names). Other commercially available products include Acryset BPF-307 manufactured by Nippon Shokubai Co., Ltd., in which core-shell type acrylic rubber microparticles are uniformly dispersed in an epoxy resin. However, core-shell type acrylic rubber microparticles are not limited to these.

[0079] The core-shell acrylic rubber microparticles are included in an amount that will impart good properties to the adhesive composition after curing. Specifically, they are used in the range of 1 to 50 parts by weight per 100 parts by weight of the total of component (1). If the amount is less than 1 part by weight, the adhesive strength will decrease and sufficient measures against separation and uncured adhesive will not be obtained. If the amount is more than 50 parts by weight, the adhesive strength will decrease and the viscosity will increase, which tends to make the adhesive composition less easy to work with.

[0080] (5) Acidic compounds and / or boric acid esters The acidic compound and / or boric acid ester used in this embodiment reacts with the surface of the curing accelerator to block the basicity of the surface of the curing accelerator, and has the effect of further improving the storage stability of the composition during storage.

[0081] The acidic compound is an organic or inorganic acid that is liquid or solid at room temperature, such as, but not limited to, sulfuric acid, acetic acid, adipic acid, tartaric acid, fumaric acid, barbituric acid, boric acid, pyrogallol, phenolic resins, and carboxylic acid anhydrides.

[0082] The borate esters are liquid or solid at room temperature, and examples thereof include, but are not limited to, trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-n-butyl borate, tripentyl borate, triallyl borate, trihexyl borate, tricyclohexyl borate, trioctyl borate, trinonyl borate, tridecyl borate, tridodecyl borate, trihexadecyl borate, trioctadecyl borate, tris(2-ethylhexyloxy)borane, bis(1,4,7,10-tetraoxaundecyl)(1,4,7,10,13-pentaoxatetradecyl)(1,4,7-trioxaundecyl)borane, tribenzyl borate, triphenyl borate, tri-o-tolyl borate, tri-m-tolyl borate, and triethanolamine borate.

[0083] These (5) acidic compounds and / or boric acid esters may be used alone or in combination of two or more. Furthermore, a masterbatch of these acidic substances mixed with epoxy resins or the like may be added as a storage stability improver. Commercially available examples of such storage stability improvers include, but are not limited to, Cureduct L-07N manufactured by Shikoku Chemical Industries, Ltd. The amounts of these acidic substances and boric acid esters added are not particularly limited, but are preferably added in the range of 0.01 to 10 parts by weight per 100 parts by weight of the resin component (1). While the addition of these acidic substances and boric acid esters further improves storage stability, curability decreases when the amount added exceeds 10 parts by weight, and no effect is observed when the amount added is less than 0.01 part by weight.

[0084] The heat-curable one-component resin composition may contain appropriate amounts of additives such as colorants such as pigments and dyes, inorganic fillers such as calcium carbonate, talc, silica, alumina, and aluminum hydroxide, flame retardants, organic fillers, plasticizers, antioxidants, antifoaming agents, coupling agents, leveling agents, and rheology control agents. The addition of these additives can result in a composition with superior resin strength, adhesive strength, flame retardancy, thermal conductivity, and workability.

[0085] Preferred physical properties include a viscosity of 2 to 5 Pa·s (25° C., 20 rpm) and a specific gravity of 1.1 to 1.2.

[0086] <Second embodiment> Next, a second embodiment of the writing instrument refill according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to this embodiment. Furthermore, elements that can be described in the same manner as in the first embodiment described above will be assigned the same reference numerals and will not be described again.

[0087] Figures 4 and 5 are diagrams showing an example of the configuration of a second embodiment of a writing instrument refill according to the present invention, where Figure 4(a) shows a front view of the appearance of the refill housed in a ballpoint pen, Figure 4(b) shows a side view of the appearance of this refill, Figure 4(c) shows a side cross-sectional view of this refill, Figure 4(d) shows an enlarged cross-sectional view of the dotted line portion in Figure 4(c), and Figures 5(a) and (b) show oblique views of this refill.

[0088] <Overall structure> 4, the refill 30 of this embodiment includes, for example, the ink containing tube 12 described above, a joint 31 attached to the tip of the ink containing tube 12, and the ballpoint pen tip 11 attached to the tip of the joint 31. In other words, the ballpoint pen tip 11 and the ink containing tube 12 are connected via the joint 31.

[0089] <Joints> Figure 6 shows an example of the configuration of the joint 31 used in the refill 30 of this embodiment, where (a) is a front oblique view, (b) is a rear oblique view, (c) is a bottom view, (d) is a plan view, (e) is a side view, (f) is a side cross-sectional view, (g) is a front view, and (h) is a front cross-sectional view.

[0090] As shown in Figures 6 and 4(c), the joint 31 is configured to include a joint portion 21 formed in an approximately cylindrical shape as the rear end portion that joins with the ink containing tube 12, a flange portion 41 formed with an outer diameter larger than that of the joint portion 21, and a cylindrical portion 24 formed with an outer diameter smaller than that of the flange portion 41 and formed in an approximately cylindrical shape all the way to the tip.Furthermore, the flange portion 41 is formed with a through hole 42 that allows excess adhesive to flow to the outside so as not to accumulate, and a groove portion 43 that is arranged so that the ink containing tube 12 can be fitted into to allow excess adhesive to flow into the through hole 42.

[0091] In addition, in the joint 31 having the above-described configuration, the press-fit portion 11a of the ballpoint pen tip 11 is press-fitted into the tip insertion hole 26 inside the tip, as shown in FIG. 4(d), for example. In the refill 30 of this embodiment, the joining portion 21 formed at the rear end of the joint 31 is press-fitted into the tip of the ink containing tube 12. At this time, the tip of the ink containing tube 12 is fitted into the groove 43 of the flange 41 and pushed close to the bottom, but does not abut against the bottom of the groove 43. In other words, the ink containing tube 12 is joined to the joining portion 21 at a position where it does not abut against the bottom of the groove 43.

[0092] As in the first embodiment, adhesive is applied to the joint 21 of the fitting 31 before press-fitting to ensure a certain level of bonding strength at the joint with the ink containing tube 12. Then, with the adhesive applied, the joint 21 of the fitting 31 is press-fitted into the tip of the ink containing tube 12, thereby joining the fitting 31 and the ink containing tube 12. At this time, excess adhesive that has been pushed away by the ink containing tube 12 due to the press-fitting is further pushed into the groove 43, and the excess adhesive that has nowhere to go in the groove 43 due to the fitting flows out through the through-hole 42. This allows the excess adhesive to be discharged to the outside of the refill 30.

[0093] In this way, the refill 30 of this embodiment connects the ballpoint pen tip 11 and the ink containing tube 12 via the joint 31, and for example, the joint 31 is configured to connect a joining portion 21 formed in an approximately cylindrical shape as the part that joins with the ink containing tube 12, a flange portion 41 formed in an outer diameter larger than the joining portion 21 and having the function of causing excess adhesive to flow out and be removed, and a cylindrical portion 24 formed in an outer diameter smaller than the flange portion 41 and formed in an approximately cylindrical shape all the way to the tip.

[0094] At this time, in this embodiment, the joint portion 21, which has been pre-applied with adhesive, is press-fitted into the tip of the ink containing tube 12. Then, the tip of the ink containing tube 12, which has been pressed in by the press-fitting, is further inserted into the groove portion 43 and pushed close to the bottom of the groove portion 43 (a position where it does not abut the bottom), and the ink containing tube 12 and the joint portion 21 are joined at this position. In other words, the ink containing tube 12 and the joint portion 21 are joined together with a space between the tip of the ink containing tube 12 and the bottom of the groove portion 43.

[0095] With this configuration, excess adhesive washed away by the ink reservoir 12 is washed into the groove 43, and any excess adhesive that overflows from the groove 43 due to being fitted in is discharged from the through-hole 42, so that the adhesive does not adversely affect the refill 30 or the ballpoint pen itself. In other words, in this embodiment, the adhesive provides a certain level of bonding strength to the bonded portion between the fitting 31 and the ink reservoir 12, while eliminating the need for repair work when the adhesive leaks out, which has remained a problem in the past.

[0096] <Third embodiment> Next, a third embodiment of the writing instrument refill according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to this embodiment. Furthermore, elements that can be described in the same manner as in the first embodiment described above will be given the same reference numerals and will not be described again.

[0097] Figures 7 and 8 are figures showing an example of the configuration of a third embodiment of a writing instrument refill according to the present invention, where Figure 7(a) shows a front view of the appearance of the refill housed in a ballpoint pen, Figure 7(b) shows a plan view of the appearance of this refill, Figure 7(c) shows an AA cross-sectional view (side cross-sectional view) of this refill, Figure 7(d) shows a BB cross-sectional view of this refill, Figure 7(e) shows an enlarged cross-sectional view of the dotted line portion of Figure 7(c), Figure 7(f) shows an enlarged cross-sectional view of the dotted line portion of Figure 7(d), and Figures 8(a) and (b) show oblique views of this refill.

[0098] <Overall structure> 7, the refill 50 of this embodiment includes, for example, the ink containing tube 12 described above, a joint 51 attached to the tip of the ink containing tube 12, and the ballpoint pen tip 11 attached to the tip of the joint 51. In other words, the ballpoint pen tip 11 and the ink containing tube 12 are connected via the joint 51.

[0099] <Joints> Figure 9 shows an example of the configuration of the joint 51 used in the refill 50 of this embodiment, where (a) is a front oblique view, (b) is a rear oblique view, (c) is a bottom view, (d) is a plan view, (e) is a front view, (f) is an AA cross-sectional view, and (g) is a BB cross-sectional view.

[0100] This embodiment differs from the first embodiment in that, for example, a step 61 is provided inside the adhesive receiving portion 22 of the flange 23, which has a locking surface formed at a certain height from the bottom surface of the adhesive receiving portion 22 and contacts the outer circumferential surface of the joint portion 21 at that height. In this case, it is preferable that multiple step portions 61 are provided uniformly in the radial direction from the outer circumferential surface of the joint portion 21, as shown in Figures 8 and 9.

[0101] Furthermore, in the refill 50 of this embodiment, the joint 21 formed at the rear end of the joint 51 provided as described above is press-fitted into the tip of the ink containing tube 12. At this time, the tip of the ink containing tube 12 is pushed into the adhesive receiving portion 22 by the press-fitting, and then, as shown in Figures 7(e) and 7(f), it is locked by (comes into contact with) the locking surface formed on the step portion 61. In other words, the ink containing tube 12 is joined to the joint 21 at a position where it abuts against the step portion 61 (at the certain height described above) without abutting against the bottom of the adhesive receiving portion 22.

[0102] In addition, excess adhesive that is pushed away by the tip of the ink containing tube 12 and leaks out due to the press-fitting flows into the space from the engagement surface of the step portion 61 (the fixed height mentioned above) to the bottom surface of the adhesive receiving portion 22 and is sealed there.

[0103] The configuration with the step portion 61 provides the same effects as the first embodiment described above, and further allows the joining position between the ink containing tube 12 and the joint 51 to be constant.

[0104] In this embodiment, as an example, multiple step portions 61 are provided evenly in the radial direction from the outer peripheral surface of the joint portion 21, but this is not limited to this, and the step portion 61 may be, for example, a single step portion as long as it can engage the tip of the ink containing tube 12 at a fixed position. [Explanation of symbols]

[0105] 10, 30, 50 refills 11 Ballpoint pen tip 11a Press-fit part 12 Ink reservoir tube 13,31,51 Joints 21 Joint 22 Adhesive receiver 23,41 Tsuba section 24 Cylindrical part 25 Ink flow hole 26 Tip insertion hole 27 Inner surface part 42 Through hole 43 Groove 61 Step part

Claims

[Claim 1] The invention described herein.

Images