Writing implement

Abstract

To provide an environmentally friendly writing implement using a writing implement part formed by integrating two types of parts.SOLUTION: A writing implement member is formed by two-color molding, with one resin molded member being formed as a primary molded body and the other resin molded member being a secondary molded body bonded to the primary molded body, the primary molded body being a functional part formed from virgin material, and the secondary molded body having a resin molded member which is a non-functional part formed from environmentally friendly material.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a writing instrument. [Background technology]

[0002] BACKGROUND ART Writing implements using resin molded members formed by two-color molding, such as that shown in Patent Document 1, have been disclosed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2015-71292 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the writing instrument described in Patent Document 1, although the resin molded parts are made of different materials, it is assumed that so-called virgin materials are used for both the primary molding material and the secondary molding material, and it is not a writing instrument that uses environmentally friendly materials in accordance with the Sustainable Development Goals (SDGs) that have been called for recently. In light of the above, the objective is to provide a writing instrument that uses environmentally friendly materials. [Means for solving the problem]

[0005] Therefore, the inventors have carried out intensive development and have achieved the following invention. This writing instrument is equipped with resin molded parts, and is formed by two-color molding, with one of the resin molded parts being formed as a primary molded body and the other being a secondary molded body bonded to the primary molded body, the primary molded body being a functional part formed from virgin material, and the secondary molded body being a non-functional part formed from environmentally friendly material. Virgin material refers to resin material that has not yet been used, i.e., has not undergone a usage cycle. This is what is known as a brand new resin molded product.

[0006] In the present invention, functional parts refer to parts whose physical properties are likely to change when they come into contact with liquids such as ink, and parts that require fitting or press-fitting with other parts, such as the press-fit portion between a clip and a cap, parts that require fitting, and parts that require fitting between a barrel and a cap.

[0007] Environmentally friendly materials include post-consumer materials and resin materials containing starch, rice flour, cellulose-derived materials, used tea leaves, coffee beans, grain husks, charcoal, bamboo charcoal, seaweed, algae, wood flour, bamboo flour, rice husk flour, used rice flour, or rice bran powder, or biomass materials such as vegetable oils and fats, plant-derived materials, industrial recycled plastics, and plastics derived from marine waste. Post-consumer materials are materials described in JIS Q14021:2000. These materials are generated from materials discarded from households or products by commercial, industrial, and other facilities that are no longer usable for their intended purposes. They are materials that were once shipped to the market, then recovered and reused after use by the user or facility. It is preferable that they contain at least 10% or more of these materials in the secondary molded body.

[0008] Furthermore, it is preferable that the biomass content of environmentally friendly materials be 10 pMC or higher. Biomass content is a value measured by radiocarbon (C14) analysis to determine the amount of carbon derived from biomass. Virgin synthetic resins have a carbon content of less than 10 pMC. The biomass content can be calculated by measuring the percentage of carbon contained in the outer layer of the material. If all components were made from environmentally friendly materials, their physical properties would be unstable, which could adversely affect the mechanical properties of the components. Therefore, by using two-color molded parts made of virgin materials for functional components and environmentally friendly materials for non-functional components, it is possible to provide a writing instrument with molded parts that are environmentally friendly and do not impair the functionality of the components. [Effects of the Invention]

[0009] By using the above-described means, it is possible to provide a more environmentally friendly product than before by using virgin materials for functional parts and environmentally friendly materials for non-functional parts. [Brief explanation of the drawings]

[0010] [Figure 1] The appearance of the writing implement of the embodiment is shown in a front view (A) and a side view (B). [Figure 2] FIG. 2 is a cross-sectional view taken along line VV of FIG. [Figure 3] The barrel of the writing implement of FIG. 1 is shown in a perspective view (A), a side view (B), a cross-sectional view (C) taken along line IIc-IIc in FIG. 3(B), and a cross-sectional view (D) taken along line IId-IId in FIG. [Figure 4] The clip of the writing implement of FIG. 1 is shown in a front view (A), a perspective view (B), a side view (C), and a cross-sectional view (D) taken along line IIId-IIId in FIG. 4(A). [Figure 5] The crown of the writing instrument of Figure 1 is shown in a side view (A), a plan view (B), a bottom view (C), a top perspective view (D), a bottom perspective view (E), and a cross-sectional view (F) taken along line IV-IV in Figure 5(A). DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In the drawings described below, the side of the writing instrument 10 where the writing tip (ballpoint pen tip 13 described below) is located will be referred to as the "tip side," and the opposite side will be referred to as the "rear side." Furthermore, the surface of the writing instrument 10 viewed from the tip side will be referred to as the "flat surface," and the surface of the writing instrument 10 viewed from the rear side will be referred to as the "bottom surface." Note that symbols commonly used in the drawings indicate common parts, members, or structures, even if no special explanation is given in the explanation of each drawing.

[0012] (1) Writing instruments 10 A writing instrument 10 according to this embodiment is formed as a ballpoint pen as shown in Figure 1. Figure 1(A) is a front view of this writing instrument 10. Figure 1(B) is a side view of this writing instrument 10.

[0013] As shown in Figures 1(A) and 1(B), this writing instrument 10 has an external appearance in which a cap 17 is attached to the tip of a barrel 20 serving as a writing instrument part 50, and a tail plug 14 is attached to the rear end of the barrel 20. A clip 30 serving as a writing instrument part 50 is attached to the side of the cap 17. A crown 40 serving as a writing instrument part 50 is attached to the tip of the clip 30. The barrel 20, clip 30, and crown 40 are made of synthetic resin.

[0014] FIG. 2 is a VV cross-sectional view of FIG. 1(A). A tip barrel 11, tapered toward the tip, is attached to the tip of the barrel 20. A ballpoint pen tip 13 is attached to the tip of the tip barrel 11 via a joint 12. A collector 15, consisting of ring-shaped thin plates stacked in the axial direction, is formed in the collector housing section 23 of the barrel 20 (see FIG. 3(C)). In a direct ink type ballpoint pen, the collector 15 serves to retain the ink 18 and prevent leakage to the outside when air in the ink storage section 24 expands due to changes in air pressure or temperature. The ink 18 is stored in the ink storage section 24 of the barrel 20 in its liquid state (i.e., direct ink type). An ink guide core 16, connecting the ink storage section 24 and the ballpoint pen tip 13, passes through the axial center of the collector 15. The short side 32 of the clip 30 is inserted into the inside of the cap 17 from the tip side of the cap 17, and the crown 40 inserted further from the tip serves to prevent the clip 30 from coming off.

[0015] Figure 3 shows the structure of barrel 20 in writing instrument 10 of Figure 1. Figure 3(A) is a perspective view of barrel 20. Figure 3(B) is a side view of barrel 20. Figure 3(C) is a cross-sectional view taken along IIc-IIc in Figure 3(B). Figure 3(D) is a cross-sectional view taken along IId-IId in Figure 3(B).

[0016] As shown in FIGS. 3A to 3C, the barrel 20 serving as the writing instrument component 50 has an appearance in which a substantially cylindrical outer barrel 22 is fitted around the middle of a substantially cylindrical inner barrel 21. The front end of the inner barrel 21 is open and the rear end is closed. The inner barrel 21 and the outer barrel 22 are formed by two-color molding using synthetic resins with different compositions. The synthetic resin forming the inner barrel 21 is made of virgin material because it comes into contact with ink and is required for fitting and press-fitting with the front barrel 11, tail plug 14, cap 17, etc. The synthetic resin forming the outer barrel 22 is a non-functional component and is therefore made of an environmentally friendly material. Biomass-derived polyolefin is used as the environmentally friendly material for the outer barrel 22. Suitable examples of biomass-derived polyolefin include polyethylene resin and polypropylene resin. From the perspective of carbon neutrality and environmental consideration, the biomass plastic content of biomass-derived polyolefin is preferably 80% or higher. The upper limit is not particularly limited, but is usually less than 99% due to the possibility of mixing in other agents during molding. Therefore, the biomass plastic content of biomass-derived polyolefins is preferably 80% or more and less than 99%. The biomass plastic content is specified in ASTM D6866.

[0017] The barrel 20 has a shape in which the outer diameter is reduced at both the front end 26, where the cap 17 is attached, and the rear end 28, where the tail plug 14 is attached, compared to the middle section 27, where the outer tube 22 is fitted. As shown in Figure 3(C), the internal space of the front end 26 of the barrel 20 forms a collector housing section 23, where the collector 15 (see Figure 2) is housed. The internal spaces of the middle section 27 and the rear end 28 of the barrel 20 form an ink storage section 24, where the ink 18 (see Figure 2) is housed. The inner peripheral surface of the ink storage section 24 has multiple ribs 25, which are protrusions along the longitudinal direction, evenly spaced about the axis.

[0018] Figure 4 shows the structure of the clip 30 in the writing instrument 10 of Figure 1. Figure 4(A) is a front view of the clip 30. Figure 4(B) is a perspective view of the clip 30. Figure 4(C) is a side view of the clip 30. Figure 4(D) is a cross-sectional view taken along IIId-IIId in Figure 4(A). Figure 4(E) is a cross-sectional view taken along IIIe-IIIe in Figure 4(A).

[0019] As shown in FIGS. 4(B) and 4(C), the clip 30 as a writing instrument component 50 is composed of a long side 31 exposed to the outside of the cap 17 (see FIG. 1(B)), a short side 32 embedded in the cap 17, a connecting side 33 connecting the long side 31 and the short side 32 at their leading ends, and a fold 34 formed by folding the rear end of the long side 31 inward. Also, as shown in FIG. 4(D), the portion constituting the long side 31 has a two-layer structure consisting of an outermost layer 51 and an inner layer 52. That is, the outermost layer 51 and the inner layer 52 are formed by two-color molding of synthetic resins with different compositions, and the interiors of the outermost layer 51 and the inner layer 52 are visible. The synthetic resin constituting the outermost layer 51 is made of virgin material because it is required for functionality such as fitting and press-fitting with the cap 17, etc. The synthetic resin constituting the inner layer 52 is a non-functional component and is therefore made of an environmentally friendly material. When the inner layer is made of biomass or biologically derived materials, the biomass ratio of the inner layer is preferably 10 pMC or more. The biomass ratio can be calculated using the following formula. Biomass ratio = dry weight of biologically derived raw materials (g) / total weight of component materials (g) x 100

[0020] Figure 5 shows the structure of crown 40 in writing instrument 10 of Figure 1. Figure 5(A) is a side view of crown 40. Figure 5(B) is a plan view of crown 40. Figure 5(C) is a bottom view of crown 40. Figure 5(D) is a top perspective view of crown 40. Figure 5(E) is a bottom perspective view of crown 40. Figure 5(F) is a cross-sectional view taken along line IV-IV in Figure 5(A).

[0021] As shown in Figures 5(A), 5(C), 5(D), 5(E), and 5(F), crown 40 as writing instrument component 50 is composed of a substantially hemispherical dome portion 41, a disk-shaped flange portion 42 that expands in diameter at the rear end of dome portion 41, a substantially cylindrical press-fit portion 43 that protrudes rearward from flange portion 42, and an inner piece 44 that is press-fitted into a first through hole 45 that passes through dome portion 41, flange portion 42, and press-fit portion 43. Inner piece 44 is provided with a second through hole 46 that passes through from the front end to the rear end.

[0022] As shown in FIG. 5(F), the portion corresponding to the dome portion 41 has a two-layer structure consisting of an outermost layer 51 and an inner layer 52. That is, the outermost layer 51 and the inner layer 52 are formed by two-color molding of synthetic resins with different components. The synthetic resin constituting the outermost layer 51 is made of virgin material because it is required for functionality such as fitting and press-fitting with the cap 17, etc. The synthetic resin constituting the inner layer 52 is a non-functional part and is therefore made of an environmentally friendly material. The environmentally friendly material used for the inner layer 52 is preferably a hydrated vegetable residue with a moisture content of 20 to 95% by weight. Examples of vegetable residues include beverage residues from green tea, oolong tea, coffee, black tea, etc.; vegetable residues from radish, potato, corn, etc.; beverage residues from chocolate, milk pomace, discarded milk, etc.; cut bamboo, grass clippings, bran, crab shells, mushroom soil, etc. The moisture content refers to the weight percentage of moisture contained in the hydrous organic residue. If the moisture content is less than 20% by weight, the dispersibility of the components decreases, which is likely to cause problems such as poor appearance of the resulting molded product and reduced discharge volume during extrusion molding. If the moisture content exceeds 95% by weight, the mixability in the mixer decreases, which is likely to cause problems such as poor appearance of the resulting molded product and reduced discharge stability during extrusion molding.

[0023] The ink 18 may be supplied not by direct liquid supply but by being soaked in a batting contained in the ink storage section 24. Also, the barrel 20 itself may not be provided with the ink storage section 24, and a separate ballpoint pen refill may be housed inside the barrel 20. [Industrial Applicability]

[0024] The present invention can be used in writing instruments such as ballpoint pens, felt-tip pens, and mechanical pencils. [Explanation of symbols]

[0025] 10 Writing instruments 11 First axis 12 Joints 13 Ballpoint pen tip 14 tail plug 15 Collector 16 Ink guide core 17 Cap 18 Ink 20 shaft cylinder 21 Inner cylinder 22 Outer cylinder 23 Collector Housing 24 Ink storage section 25 Ribs 26 Tip 27 Middle section 28 Rear end 30 clips 31 Long side 32 Short Side 33 Connecting Edges 34 Turn Around 40 Crown of Heaven 41 Dome section 42 Flange 43 Press-fit section 44 Inner Peace 45 First through hole 46 Second through hole 50 Writing instrument parts 51 Outermost layer 52 Inner layer 60 Engraving

Claims

1. In a writing instrument provided with a resin molded member, A writing instrument characterized in that one of the resin molded members is formed as a primary molded body, and the other of the resin molded members is formed by two-color molding consisting of a secondary molded body adhered to the primary molded body, the primary molded body being a functional part formed from virgin material, and the secondary molded body is provided with a writing instrument part that is a non-functional part formed from environmentally friendly material.

2. 2. The writing instrument according to claim 1, wherein the environmentally friendly material is a writing instrument part containing any one of post-consumer material, biomass material, plant-derived material, industrial recycled plastic material, and plastic material derived from marine waste.

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