Writing instrument and method for recycling writing instrument

Abstract

To solve the problem that, when a writing utensil is subjected to material recycling, since a different resin is adopted for each part, separation for each part is required and a decomposition load is high. Accordingly, an object of the present invention is to provide a writing instrument which can be material-recycled only by simple disassembly and separation.SOLUTION: In the writing utensil 100 having two or more resin parts, all the resin parts except a writing core part are composed of a resin composition containing an acrylonitrile-butadiene-styrene resin as a main component.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to writing instruments and methods for recycling writing instruments. [Background technology]

[0002] Each part that makes up a writing instrument is required to have different performance characteristics, so each part is made from a different resin material. Therefore, it is difficult to melt down writing instruments and reuse them as resin material, i.e., to recycle them as materials. Although there is an option to disassemble and separate writing instruments for material recycling, because writing instruments are not easy to disassemble, users end up discarding them as they are without disassembling or separating them.

[0003] Therefore, in order to recycle the materials of writing implements, the following writing implements have been disclosed, which are made up of parts using the same type of resin.

[0004] For example, Patent Document 1 discloses a writing instrument in which all resin components are made of the same material and grade. The writing instrument in Patent Document 1 is said to reduce the amount of raw materials used and contribute to improving the global environment.

[0005] Patent Document 2 discloses a writing implement made of acrylonitrile-butadiene-styrene resin, in which a writing stem is formed by separably joining two writing stem members divided into two by an axial plane, a ring body made of an elastic material is fitted into a groove formed around the outer periphery of the tip of the writing stem to fix the writing stem members together, and the inner wall of the cover covering the outer periphery of the tip of the writing stem is engaged with the ring body protruding from within the groove.The writing implement in Patent Document 2 is said to be easily disassembled by removing the ring body. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-025381 [Patent Document 2] Japanese Utility Model Application Publication No. 6-064967 Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, different resins have been used for each part that makes up a writing instrument in order to satisfy various requirements such as transparency, sliding properties, and flexibility. Therefore, when melting and reusing the resin material, i.e., when recycling materials, it is necessary to separate each part, which increases the disassembly load. Furthermore, when the writing instrument has a structure that employs press-fit fittings, the disassembly load is even higher. In response to this, if it were possible to design a writing instrument that can be recycled with simple disassembly and separation, it would be possible to further improve the recyclability of writing instruments.

[0008] Therefore, an object of the present invention is to provide a writing instrument that can be recycled by simply disassembling and separating the materials. [Means for solving the problem]

[0009] The present inventors have conducted extensive research and found that the above problems can be solved by the following means, and have completed the present invention. That is, the present invention is as follows: <Aspect 1> A writing instrument having two or more resin parts, All of the resin parts except for the writing core are made of a resin composition whose main component is acrylonitrile-butadiene-styrene resin. Writing implements. <Aspect 2> A writing instrument according to aspect 1, wherein the acrylonitrile-butadiene-styrene resin contained in a first of the resin parts excluding the writing core and the acrylonitrile-butadiene-styrene resin contained in a second of the resin parts excluding the writing core have different physical properties. <Aspect 3> A writing instrument according to aspect 1 or 2, wherein the composition of the first resin composition constituting the first of the resin parts excluding the writing core portion is different from the composition of the second resin composition constituting the resin parts excluding the writing core portion. <Aspect 4> A method for recycling a writing instrument according to any one of aspects 1 to 3, comprising the steps of: Melting the resin parts excluding the writing core to obtain a molten resin composition; and The molten resin composition is molded to form a molded article. [Effects of the Invention]

[0010] The writing implement of the present invention can be recycled by simply disassembling and separating the materials. [Brief explanation of the drawings]

[0011] [Figure 1] 1(a) to 1(c) are a plan view, a front view, and a vertical cross-sectional view, respectively, of a writing instrument according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] 《Writing implements》 The writing instrument of the present invention comprises: It has two or more plastic parts, and All resin parts except the writing core are made from a resin composition whose main component is acrylonitrile-butadiene-styrene (ABS) resin.

[0013] The inventors have discovered that each of the resin parts that make up a writing instrument and that are required to have various performance capabilities, excluding the writing core, can be made using an ABS resin composition containing ABS resins with different physical properties, and / or an ABS resin composition whose physical properties have been adjusted by additives, etc.

[0014] Furthermore, the present inventors have found that the writing implement can be recycled by simple disassembly and separation, even though it contains various ABS resin compositions.

[0015] 1 and 2, a brief description will be given of the configuration of a writing instrument 100, which is an embodiment of the present invention. The writing instrument 100 is a knock-type ballpoint pen. Note that the present invention is not limited to this embodiment, and various modifications can be made within the scope of the gist of this disclosure.

[0016] 1(a) to 1(c) are a plan view, a front view, and a longitudinal cross-sectional view, respectively, of a writing instrument 100 according to an embodiment of the present invention. In this specification, the tip of the writing instrument 100, i.e., the nib side, is defined as the "front" side of the writing instrument 100, and the side opposite the nib of the writing instrument 100 along the axial direction (longitudinal direction) of the writing instrument 100 is defined as the "rear" side of the writing instrument 100.

[0017] The writing instrument 100 comprises a rear barrel 110 which is integral with the clip 116, a front barrel 120 which is arranged in front of the rear barrel 110, a grip 130 formed on the outer surface of the front barrel 120, a knock cover 140 which is arranged at the rear end of the writing instrument 100, a tip member 150 which is arranged at the front end of the writing instrument 100, a rotor 160 housed inside the rear barrel 110, and a writing core portion 170 which extends in front of the rotor 160.

[0018] The front barrel 120 and the grip 130, as well as the rear barrel (primary molded portion) 112 and the rear barrel (secondary molded portion) 114 are molded in two colors.

[0019] The writing core 170 is made up of a spring 172 that biases the writing core 170 rearward, an ink reservoir 174 that contains ink, and a ballpoint pen tip 176 at the front end. The knock cover 140 can be moved back and forth with a finger to cause the ballpoint pen tip 176 to protrude from and retract into the tip member 150.

[0020] Each component of the present invention will be described below.

[0021] The writing instrument of the present invention has two or more resin parts.

[0022] The resin parts include, for example, a front barrel, a grip, a rear barrel, a tip member, a rear barrel, a rotor, a knock cover, and a writing lead.

[0023] Of the parts that make up the writing core, the spring is generally made of metal, but it may also be made of resin.

[0024] All of the resin parts of the writing implement of the present invention, excluding the writing core, are made of a resin composition containing ABS resin as the main component (ABS resin composition).

[0025] Here, with respect to the present invention, the "main component" of the resin composition means a material that constitutes more than 50 parts by mass, for example, 60 parts by mass or more, 70 parts by mass or more, 80 parts by mass or more, or 90 parts by mass or more, or 95 parts by mass or more, per 100 parts by mass of the ABS resin composition, and this proportion may be 98 parts by mass or less, 95 parts by mass or less, 90 parts by mass or less, 80 parts by mass or less, 70 parts by mass or less, or 60 parts by mass or less.

[0026] Acrylonitrile-butadiene-styrene (ABS) resin is a thermoplastic resin composed of three types of monomers: acrylonitrile (A), butadiene (B), and styrene (S).

[0027] The composition of the first resin composition constituting the first of the resin parts excluding the writing core may be different from the composition of the second resin composition constituting the resin parts excluding the writing core. The composition of the first resin composition and the composition of the second resin composition may be the same. Here, "the two resin compositions have the same composition" means that the types and amounts of the auxiliary materials contained in the two resin compositions are the same. Therefore, the physical properties (see below) of the ABS resin itself contained in the two resin compositions may be the same or different.

[0028] The ABS resin composition may contain a secondary material.

[0029] The mass of the above-mentioned secondary material is preferably less than the mass of the ABS resin in each resin part, from the viewpoint of ensuring the necessary physical properties of the molten resin composition obtained by melting the resin parts excluding the writing core.

[0030] The ABS resin composition may contain colorants such as pigments and dyes as secondary materials. These colorants may be in the form of, for example, dry color, paste color, color compound, masterbatch, etc.

[0031] As the pigment, for example, organic pigments, inorganic pigments, luster pigments, etc. can be used.

[0032] Examples of the organic pigment that can be used include azo pigments, lake pigments, phthalocyanine pigments, quinacridone pigments, dioxazine pigments, perylene red pigments, and isoindolinone pigments.

[0033] Examples of the inorganic pigment that can be used include black iron oxide, yellow iron oxide, red iron oxide, chromium oxide, titanium oxide, carbon black, and ultramarine.

[0034] As the above-mentioned bright pigment, for example, aluminum powder, synthetic mica, natural mica, etc. can be used.

[0035] It is preferable that the amount of the above colorant be less than 10 parts by mass, less than 8 parts by mass, less than 6 parts by mass, less than 5 parts by mass, less than 4 parts by mass, or less than 3 parts by mass relative to 100 parts by mass of the ABS resin composition constituting each resin part, from the viewpoint of ensuring the necessary physical properties of the molten resin composition obtained by melting the resin parts excluding the writing core.

[0036] The content of ABS resin contained in the ABS resin composition that constitutes all of the resin parts excluding the writing core is preferably 50% by mass or more, 55% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more, from the viewpoint of ensuring the necessary physical properties of the molten resin composition obtained by melting the resin parts excluding the writing core.

[0037] The ABS resin contained in the first resin part of the resin parts excluding the writing core and the ABS resin contained in the second resin part of the resin parts excluding the writing core may have different physical properties, such as the degree of polymerization (molecular weight) and monomer composition.

[0038] By selecting the degree of polymerization (molecular weight) and monomer composition ratio of the ABS resin, the composition and amount of auxiliary materials, and the composition and amount of pigments, each resin part can meet its required physical properties.

[0039] The physical properties required for each resin part include, for example, transparency, flexibility, sliding property, flowability, mechanical strength, chemical resistance, oil resistance, light resistance, and the like.

[0040] The resin parts of the writing implement of the present invention, excluding the writing core, can be produced by molding, for example, injection molding, an ABS resin composition.

[0041] Below, examples of physical properties required for each resin part excluding the writing core are given.

[0042] <Front shaft cylinder> Front barrels are often required to have high durability. If ABS resin alone cannot meet the durability required for a writing instrument part, it is preferable to add a secondary material.

[0043] Examples of the secondary materials that can be used include impact strength modifiers (butadiene rubber), weather resistance / impact strength modifiers (acrylic rubber), antioxidants, ultraviolet absorbers, light stabilizers, light shielding materials, dispersants, etc. These materials are commercially available.

[0044] The oil resistance of the front barrel is preferably such that no cracks occur when sesame oil is left on it for 24 hours under the standard conditions specified in JIS-Z8703.

[0045] <grip> Grips often require high flexibility. If ABS resin alone cannot meet the required quality, it is preferable to add a secondary material.

[0046] The flexibility of the grip is preferably such that the durometer hardness measured in accordance with JIS-K-7215 is HDA 55 or more, 60 or more, or 65 or more, and is preferably 80 or less, 75 or less, or 70 or less.

[0047] As the secondary material, for example, polyester-based thermoplastic elastomer, urethane-based thermoplastic elastomer, olefin-based thermoplastic elastomer, and styrene-based thermoplastic elastomer can be used.

[0048] Grips are often required to have high oil and light resistance.

[0049] The oil resistance of the grip is preferably such that the shaft and grip do not separate when the front barrel and grip formed by two-color molding are immersed in moisturizing cream for 24 hours under the standard conditions described in JIS-Z8703.

[0050] The grip's light resistance is measured by exposing the grip to ultraviolet light at an irradiance of 320W / m 2 It is preferable that when the film is irradiated with light at 100 Hz for 100 hours, no discoloration occurs when visually observed.

[0051] <Liking parts> High durability is often required for tip components. If ABS resin alone cannot meet the required durability, a secondary material can be added.

[0052] Examples of secondary materials that can be used include impact strength modifiers (butadiene rubber), weather resistance / impact strength modifiers (acrylic rubber), antioxidants, UV absorbers, light stabilizers, light shielding materials, and dispersants.

[0053] The oil resistance of the tip member is preferably such that no cracks occur when sesame oil is applied to the tip member for 24 hours under the standard conditions described in JIS-Z8703.

[0054] <Rear cylinder> Rear barrels often require high sliding properties. If ABS resin alone cannot meet the required sliding properties, secondary materials can be added.

[0055] As the secondary material, it is preferable to use, for example, a silicone-acrylic copolymer resin.

[0056] It is preferable that the durability of the rear barrel is such that the ballpoint pen tip can be extended and retracted without damage to the rear barrel or deterioration in sliding properties even after the ballpoint pen tip is extended and retracted 15,000 times with a pressing load of 5N against the knock cover.

[0057] The oil resistance of the rear barrel is preferably such that no cracks occur when sesame oil is left on it for 24 hours under the standard conditions specified in JIS-Z8703.

[0058] <Rotor> Rotors often require high sliding properties. If ABS resin alone cannot meet the required sliding properties, auxiliary materials can be added.

[0059] As the secondary material, for example, a silicone-acrylic copolymer resin can be used.

[0060] Rotors are often required to have high durability.

[0061] The durability of the rotor is preferably such that the ballpoint pen tip can be extended and retracted without damage to the rotor or deterioration in sliding properties even after 15,000 times of extending and retracting the ballpoint pen tip against the knock cover with a pressing load of 5N.

[0062] <Knock cover> Knock covers often require high sliding properties. If ABS resin alone cannot meet the required sliding properties, it is preferable to add a secondary material.

[0063] As the secondary material, it is preferable to use, for example, a silicone-acrylic copolymer resin.

[0064] Knock covers are often required to have high durability.

[0065] The durability of the knock cover is preferably such that the ballpoint pen tip can be extended and retracted without damage to the knock cover or deterioration in sliding properties even after the ballpoint pen tip is extended and retracted 15,000 times with a pressure load of 5 N applied to the knock cover.

[0066] How to recycle writing instruments The method of the present invention for recycling a writing instrument of the present invention comprises the steps of: Melting the resin parts excluding the writing core to obtain a molten resin composition; and Molding the molten resin composition to form a molded article.

[0067] A writing implement made of the above-mentioned ABS resin composition can be obtained by melt-kneading all the resin parts together, excluding the writing tip, without separating them into individual resin parts, to obtain a molten resin composition.

[0068] The molten resin composition can be molded in the same manner as any of the resin parts made of the ABS resin composition, and can be used in writing implements in place of the resin parts.

[0069] A writing instrument having resin parts obtained by molding the above-mentioned molten resin composition may be melt-kneaded together without separating the resin parts, excluding the writing core, to obtain a new molten resin composition.

[0070] The type of resin part obtained by molding the above-mentioned molten resin composition is not limited as long as it satisfies the required physical properties, but a rear barrel or tip member, which does not require much transparency and flexibility, is preferred.

[0071] The mechanical strength of the molten resin composition is preferably such that the elongation at break (strain) in the tensile test according to JIS-K-7113 is 10% or more.

[0072] The oil resistance of the molten resin composition is preferably such that no cracks occur when sesame oil is applied to the composition for 24 hours under the standard conditions described in JIS-Z8703. [Example]

[0073] The present invention will be specifically explained with reference to Example 1, but the present invention is not limited thereto.

[0074] <Evaluation of resin parts made of ABS resin composition> <Making resin parts> As Example 1, a resin part molded from the ABS resin and auxiliary materials shown in Table 1 was produced. [Table 1]

[0075] As Comparative Example 1, a resin part molded from the resin in Table 2 was produced. [Table 2]

[0076] <evaluation> (Durability evaluation of tip member, front barrel, rear barrel, rotor, and knock cover) For the writing instruments of Example 1 and Comparative Example 1, the ballpoint pen tip was extended and retracted 15,000 times with a pressure load of 5N on the knock cover, and the rear barrel, rotor, and knock cover were evaluated according to the following criteria to see if there was any damage or deterioration in sliding properties to the ballpoint pen tip. A: The ballpoint pen tip can be extended and retracted. B: The ballpoint pen tip cannot be extended or retracted.

[0077] (Evaluation of oil resistance of tip material, front barrel, and rear barrel) Sesame oil was applied to the clip portion of the rear barrel of Example 1 and Comparative Example 1 for 24 hours under the standard conditions specified in JIS-Z8703, and the occurrence of cracks was evaluated according to the following criteria. A: No cracks have occurred in the tip, clip, or shaft. B: Cracks have occurred in all or any of the tip member, clip portion, and stem portion.

[0078] (Grip oil resistance evaluation) The front barrels and grips molded by two-color molding in Example 1 and Comparative Example 1 were immersed in hand cream (Nibeya Cream, manufactured by Kao Corporation) for 24 hours under the standard conditions specified in JIS-Z8703, and the separation of the front barrels and grips was evaluated according to the following criteria. A: The front barrel and grip are not separated. B: The front barrel and grip are separated.

[0079] (Grip discoloration evaluation) In Example 1 and Comparative Example 1, a plate-shaped grip was prepared. The grip was irradiated with ultraviolet light using a fade meter (X25, manufactured by Suga Test Instruments Co., Ltd.) at an irradiance of 320 W / m 2 The color change before and after irradiation was evaluated visually. A: No discoloration is observed. B: Discoloration was observed.

[0080] (Mechanical strength evaluation of recycled materials) For Example 1 and Comparative Example 1, when the resin parts were melted together to create the rear barrel (primary molded part), a tensile test was carried out in accordance with JIS-K-7113 to determine whether or not a recycled material with sufficient mechanical strength could be obtained, and the results were evaluated according to the following criteria. A: The elongation (strain) at break is 10% or more. B: The elongation (strain) at break is less than 10%.

[0081] (Durability evaluation of recycled material) For Example 1 and Comparative Example 1, when the resin parts were melted together to create the rear barrel (primary molded part), whether recycled material with sufficient oil resistance could be obtained was evaluated by applying sesame oil for 24 hours under the standard conditions described in JIS-Z8703 and checking for the occurrence of cracks according to the following criteria. A: No cracks have occurred in the clip or shaft. B: Cracks have occurred in the clip and / or shaft.

[0082] The evaluation results are shown in Table 3. [Table 3]

[0083] From Example 1 and Comparative Example 1 in Table 3, it can be seen that even when the resin material of the rotor is changed from POM to ABS, sufficient durability is maintained.

[0084] From Example 1 and Comparative Example 1 in Table 3, it can be seen that sufficient durability is maintained even when the resin material of the knock cover is changed from PC to ABS.

[0085] From Example 1 and Comparative Example 1 in Table 3, it can be seen that even when the resin material of the grip is changed from TPE to ABS and TPE, sufficient oil resistance and light resistance are still maintained.

[0086] From Example 1 and Comparative Example 1 in Table 3, it can be seen that the resin part made of recycled material in Example 1 has sufficient mechanical strength.

[0087] From the Examples and Comparative Example 1 in Table 3, it can be seen that the resin part made of the recycled material of Example 1 has sufficient oil resistance. [Explanation of symbols]

[0088] 100 writing instruments 110 Rear shaft cylinder 112 Rear shaft cylinder (primary molding part) 114 Rear shaft cylinder (secondary molding part) 116 clips 120 Front barrel 130 Grip 140 Knock Cover 150 Tip member 160 rotor 170 Writing core 172 Spring 174 Ink reservoir 176 Ballpoint Pen Tip

Claims

1. A writing instrument having two or more resin parts, All of the resin parts except for the writing core are made of a resin composition mainly composed of acrylonitrile-butadiene-styrene resin. Writing implements.

2. The writing instrument according to claim 1, wherein the acrylonitrile-butadiene-styrene resin contained in the first resin part of the resin parts excluding the writing core and the acrylonitrile-butadiene-styrene resin contained in the second resin part of the resin parts excluding the writing core have different physical properties.

3. 2. The writing instrument according to claim 1, wherein the composition of the first resin composition constituting the first of the resin parts excluding the writing core portion is different from the composition of the second resin composition constituting the resin parts excluding the writing core portion.

4. A method for recycling a writing instrument according to any one of claims 1 to 3, comprising the steps of: Melting the resin parts excluding the writing core to obtain a molten resin composition; and The molten resin composition is molded to form a molded article.

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