Writing instrument oil-based ink composition

Abstract

The writing instrument oil-based ink composition of the present invention is a writing instrument oil-based ink composition containing: pigment, binder resin, organic solvent, and fluorinated resin particles. Taking the mass of the solid components of the aforementioned writing instrument oil-based ink composition as a basis, the total content of the aforementioned pigment and the aforementioned fluorinated resin particles is 35 to 70% by mass, and the mass ratio of the aforementioned fluorinated resin particles to the total mass of the aforementioned pigment and the aforementioned fluorinated resin particles is 0.10 to 0.45.

Description

Technical Field

[0001] This invention relates to an oil-based ink composition for writing instruments. Background Technology

[0002] For oil-based ink compositions used in ballpoint pens, properties such as excellent adhesion to various writing surfaces and lightfastness to prevent fading when exposed to sunlight for extended periods are required. In particular, oil-based inks must provide sufficiently adherent lines when writing on materials with poor wetting properties, such as synthetic resin films, resin-coated paper, and metals. Furthermore, oil-based inks must also exhibit scratch resistance after prolonged exposure to ultraviolet light and other forms of light.

[0003] To meet the above requirements, Patent Document 1 discloses an oil-based ink composition for writing instruments, which contains: a colorant, a resin, an organic solvent, and fluorinated resin particles, wherein the average particle size of the fluorinated resin particles, as measured by dynamic light scattering method, is 0.1 μm or more and less than 1.0 μm.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-11401 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] According to the oil-based ink composition for writing instruments in Patent Document 1, lines with rubbing resistance that can withstand repeated rubbing, rubbing under stronger force, and are maintained even after ultraviolet light exposure can be obtained.

[0009] However, lines are required to withstand further harsh environments. In such environments, the oil-based ink composition for writing instruments according to Patent Document 1 sometimes leaves no residue.

[0010] Therefore, the present invention provides an oil-based ink composition for writing instruments that provides lines with further enhanced rub resistance.

[0011] Solution for solving the problem

[0012] The inventors conducted in-depth research and discovered that the above-mentioned problems can be solved by the following solution, thus completing the present invention. That is, the present invention is as follows:

[0013] <Method 1> An oil-based ink composition for writing instruments, comprising: pigment, binder resin, organic solvent, and fluorinated resin particles.

[0014] Using the mass of the solid components of the aforementioned oil-based ink composition for writing instruments as a benchmark, the total content of the aforementioned pigment and the aforementioned fluorinated resin particles is 35-70% by mass, and

[0015] The mass ratio of the aforementioned fluorinated resin particles to the total mass of the aforementioned pigment and the aforementioned fluorinated resin particles is 0.10 to 0.45.

[0016] <Method 2> An oil-based ink composition for writing instruments according to Method 1, wherein the aforementioned pigment comprises a metal oxide pigment.

[0017] <Method 3> The writing instrument oil-based ink composition according to Method 2, wherein the aforementioned metal oxide pigment is titanium oxide.

[0018] <Method 4> The oil-based ink composition for writing instruments according to Method 2 or 3, wherein, when measured by dynamic light scattering method, the ratio of the average particle size of the aforementioned metal oxide pigment to the average particle size of the aforementioned fluorine resin particles is 0.2 to 4.0.

[0019] <Form 5> An oil-based ink composition for writing instruments according to any one of Forms 1 to 4, wherein the aforementioned pigment comprises a carbon-based pigment.

[0020] <Method 6> An oil-based ink composition for writing instruments according to any one of Methods 1 to 4, wherein the aforementioned fluorinated resin particles are polytetrafluoroethylene particles.

[0021] <Method 7> A writing instrument having at least an ink storage section, a writing section, and a holding section.

[0022] The aforementioned ink storage compartment contains an oil-based ink composition for writing instruments as described in any one of methods 1 to 6.

[0023] <Method 8> The writing instrument according to Method 7, wherein the writing instrument further comprises an annular ink reservoir arranged to surround the writing part.

[0024] <Method 9> The writing instrument according to Method 8, wherein the density of the aforementioned ink reservoir, according to JIS K7222, is 50 kg / m³. 3 The following, and according to JIS K6400-1, have a bubble count of 40 or more per 25mm.

[0025] The effects of the invention

[0026] According to the present invention, an oil-based ink composition for writing instruments can be provided, which provides lines with further enhanced rub resistance. Attached Figure Description

[0027] Figure 1(a) is a side view showing one embodiment of the valve-type marker of the present invention. Figure 1 (b) is a side sectional view showing one embodiment of the valve-type marker of the present invention. Detailed Implementation

[0028] Oil-based ink compositions for writing instruments

[0029] The oil-based ink composition for writing instruments of the present invention is an oil-based ink composition for writing instruments.

[0030] It contains: pigments, binder resins, organic solvents, and fluorinated resin particles.

[0031] Using the mass of the solid components of the aforementioned oil-based ink composition for writing instruments as a benchmark, the total content of the aforementioned pigment and the aforementioned fluorinated resin particles is 35-70% by mass, and

[0032] The mass ratio of the aforementioned fluorinated resin particles to the total mass of the aforementioned pigment and the aforementioned fluorinated resin particles is 0.10 to 0.45.

[0033] The inventors have discovered that, through the above-described configuration, the abrasion resistance of the lines becomes even better. Specifically, by combining (1) a high total content of pigments and fluorinated resin particles (a low total content of binder resins and dyes) with (2) a predetermined amount of fluorinated resin relative to the total mass of pigments and fluorinated resin particles, the fluorinated resin particles become less likely to move within the lines when the lines are wiped, and as a result, it is believed that the abrasion resistance provided by the fluorinated resin particles becomes easier to maintain.

[0034] The total content of pigments and fluorinated resin particles is based on the mass of the solids component of the oil-based ink composition for writing instruments, and can be 35% or more by mass, 40% or more by mass, 45% or more by mass, or 50% or more by mass; alternatively, it can be 70% or less by mass, 65% or less by mass, or 60% or less by mass. Here, "solids component of the oil-based ink composition for writing instruments" refers to the portion from which volatile components such as organic solvents have been removed.

[0035] The content of solid components in the oil-based ink composition for writing instruments can be 10% or more by mass, 15% or more by mass, 20% or more by mass, or 25% or more by mass, or less than 40% by mass, less than 35% by mass, or less than 30% by mass, based on the overall mass of the oil-based ink composition for writing instruments.

[0036] The oil-based ink composition for writing instruments of the present invention may also contain dyes.

[0037] The constituent elements of the present invention will be described below.

[0038] <pigment>

[0039] As a pigment, any pigment can be used, such as metal oxide pigments and carbon-based pigments. Additionally, other pigments used for coloring can also be used.

[0040] The average particle size of the pigment can be 50 nm or more, 70 nm or more, 90 nm or more, 100 nm or more, 120 nm or more, 150 nm or more, 170 nm or more, or 200 nm or more. Alternatively, it can be less than 1000 nm, less than 800 nm, less than 700 nm, less than 600 nm, less than 550 nm, less than 500 nm, less than 450 nm, or less than 400 nm. When the average particle size of the pigment is within the above range, the movement of fluorinated resin particles in the lines can be effectively suppressed when wiping the lines, thereby obtaining further good abrasion resistance.

[0041] In this specification, the average particle size refers to the average particle size obtained using dynamic light scattering. Specifically, this average particle size is the value of the average particle size obtained by cumulative analysis of the scattering intensity distribution using the nanoPartica SZ-100V2 nanoparticle analysis device (HORIBA).

[0042] (Metal oxide pigments)

[0043] As metal oxide pigments, talc, silica, alumina, titanium dioxide, aluminum silicate, and aluminum oxide can be used, for example.

[0044] (Carbon-based pigments)

[0045] As carbon-based pigments, amorphous carbon powder, graphene, carbon nanotubes, graphite, and carbon black can be used, for example.

[0046] (Other coloring pigments)

[0047] Other coloring pigments include, for example, azo pigments, fused azo pigments, phthalocyanine pigments, anthraquinone pigments, quinacridone pigments, isoindolineone pigments, diketopyrrolopyrrole pigments, various chelate pigments, and other organic pigments, fluorescent pigments, pearl pigments, and metallic pigments such as gold and silver.

[0048] <Adhesive Resin>

[0049] As adhesive resins, ketone resins, sulfonamide resins, maleic acid resins, terpene resins, terpene phenol resins, rosin esters, xylene resins, alkyd resins, phenolic resins, butyral resins, rosin, polyvinylpyrrolidone, polyvinyl alcohol, acrylic resins, melamine resins, cellulose resins, and their derivatives can be used. For example, rosin-modified maleic acid resins can be used as derivatives of the above resins. These resins can be used alone or in mixtures.

[0050] The content of the binder resin can be based on the mass of the solid component of the writing instrument oil-based ink composition, and can be 10% or more by mass, 15% or more by mass, 20% or more by mass, or 25% or more by mass. Alternatively, it can be 50% or less by mass, 45% or less by mass, 40% or less by mass, 35% or less by mass, or 30% or less by mass.

[0051] <Organic Solvents>

[0052] As organic solvents, such as aromatics, alcohols, polyols, glycol ethers, hydrocarbons, and esters can be used. These solvents can be used alone or in combination.

[0053] As aromatic compounds, for example, benzyl alcohol, ethylene glycol monobenzyl ether, ethylene glycol monobenzyl ether, propylene glycol monobenzyl ether, diethylene glycol monobenzyl ether, alkyl sulfonate phenyl ester, butyl phthalate, ethylhexyl phthalate, tridecyl phthalate, ethylhexyl trimellitate, diethylene glycol dibenzoate, dipropylene glycol dibenzoate, etc.

[0054] As alcohols, examples include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, 1-pentanol, isopentanol, sec-pentanol, 3-pentanol, tert-pentanol, n-hexanol, methylpentanol, 2-ethylbutanol, n-heptanol, 2-heptanol, 3-heptanol, n-octanol, 2-octanol, 2-ethylhexanol, 3,5,5-trimethylhexanol, nonanol, n-decanol, undecanol, n-decanol, trimethylnonanol, tetradecanol, heptadecanol, cyclohexanol, 2-methylcyclohexanol, etc.

[0055] As polyols, ethylene glycol, diethylene glycol, 3-methyl-1,3-butanediol, triethylene glycol, dipropylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,5-pentanediol, hexanediol, octanediol, etc. can be used.

[0056] As glycol ethers, examples include methyl isopropyl ether, diethyl ether, ethyl propyl ether, ethyl butyl ether, isopropyl ether, butyl ether, hexyl ether, 2-ethylhexyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylbutyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, 3-methyl-3-methoxy-1-butanol, 3-methoxy-1-butanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monobutyl ether, tetrapropylene glycol monobutyl ether, etc.

[0057] As hydrocarbons, straight-chain hydrocarbons such as hexane, isohexane, heptane, octane, nonane, and decane, as well as cyclic hydrocarbons such as cyclohexane, methylcyclohexane, and ethylcyclohexane can be used.

[0058] As esters, examples include propylene glycol methyl ether acetate, propylene glycol diacetate, 3-methyl-3-methoxybutyl acetate, propylene glycol ethyl ether acetate, ethylene glycol ethyl ether acetate, butyl formate, isobutyl formate, isoamyl formate, propyl acetate, butyl acetate, isopropyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, propyl propionate, isobutyl propionate, isoamyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, methyl isobutyrate, ethyl isobutyrate, and propyl isobutyrate. Methyl valerate, ethyl valerate, propyl valerate, methyl isovalerate, ethyl isovalerate, propyl isovalerate, methyl trimethylacetate, ethyl trimethylacetate, propyl trimethylacetate, methyl hexanoate, ethyl hexanoate, propyl hexanoate, methyl octanoate, ethyl octanoate, propyl octanoate, methyl laurate, ethyl laurate, methyl oleate, ethyl oleate, triglyceride octanoate, tributyl citrate, octyl hydroxystearate, propylene glycol monoricinoleate, methyl 2-hydroxyisobutyrate, 3-methoxybutylacetate, etc.

[0059] Fluorine resin particles

[0060] Fluorine resin particles are particles composed of polymers polymerized from fluorine-containing monomers. In particular, the fluorine resin particles in the oil-based ink composition for writing instruments of the present invention are fluorine resin particles with an average particle size of 100 nm or more and less than 1000 nm when measured by dynamic light scattering method.

[0061] From the viewpoint that it is easy to expose the fluorinated resin particles on the surface of the line, thereby making the line have good abrasion resistance, it is preferable that the average particle size is 100nm or more, 200nm or more, or 300nm or more. In addition, from the viewpoint that it is not easily affected by the durability of the line due to ultraviolet light, thereby maintaining the abrasion resistance of the line after durability, it is preferable that the particle size is less than 1000nm, 900nm or less, or 800nm ​​or less.

[0062] As fluorinated resin particles, fully fluorinated resin particles, partially fluorinated resin particles, and fluorinated resin-olefin copolymer particles can be used. Among them, from the viewpoint of reducing the coefficient of friction of the surface of the line and thus making the line have good abrasion resistance, fully fluorinated resin particles are preferred.

[0063] When the oil-based ink composition for writing instruments of the present invention contains metal oxide pigments, the ratio of the average particle size of the metal oxide pigments to the average particle size of the fluorinated resin particles can be 0.2 or more, 0.3 or more, 0.5 or more, 0.7 or more, 0.9 or more, 1.0 or more, or 1.2 or more; it can be 1.5 or more, 1.7 or more, or 2.0 or more; or it can be 4.0 or less, 3.5 or less, 3.3 or less, 3.0 or less, 2.8 or less, 2.5 or less, 2.3 or less, 2.0 or less, 1.7 or less, or 1.5 or less. When this ratio is within the above range, the movement of fluorinated resin particles in the lines can be effectively suppressed when erasing lines, thereby obtaining further good abrasion resistance.

[0064] Examples of fully fluorinated resin particles include polytetrafluoroethylene (PTFE) particles, perfluoroalkoxyalkylene (PFA) particles, and tetrafluoroethylene-hexafluoropropylene copolymer (FEP) particles. From the viewpoints of chemical stability and cost, PTFE is preferred.

[0065] Examples of partially fluorinated resin particles include polyvinylidene fluoride (PVDF) particles and polytrifluoroethylene chloride (PCTFE) particles.

[0066] Fluorinated resin-olefin copolymer particles are copolymer particles of fully fluorinated resin and / or partially fluorinated resin with olefins, such as tetrafluoroethylene-ethylene copolymer (ETFE) particles and trichlorofluoroethylene-ethylene copolymer (ECTFE) particles.

[0067] The ratio of the mass of fluorinated resin particles to the total mass of pigment and fluorinated resin particles can be 0.10 or more, 0.15 or more, 0.20 or more, or 0.25 or more; alternatively, it can be 0.45 or less, 0.40 or less, or 0.35 or less.

[0068] <dye>

[0069] As dyes, for example, any of the following can be used: direct dyes, acid dyes, basic dyes, mordant / acid mordant dyes, alcohol-soluble dyes, azo dyes, sulfur-based / sulfur-based dyes, dyes, disperse dyes, oil-soluble dyes, food dyes, metal complex salt dyes, salt-forming dyes, dyes dyed on resins, and solutions thereof.

[0070] <Other Ingredients>

[0071] The oil-based ink composition for writing instruments of the present invention may also contain any other components. Examples of other components include dispersants, leveling agents, rust inhibitors, corrosion inhibitors, lubricants, and resins. For example, butyral resin can be used as a dispersant. For example, fluorinated surfactants, silicone oils, and phosphate ester surfactants can be used as leveling agents.

[0072] Writing Tools

[0073] The writing instrument of the present invention is a writing instrument that includes at least:

[0074] Ink storage section, writing section, and preservation section.

[0075] The aforementioned ink storage compartment contains the aforementioned oil-based ink composition for writing instruments.

[0076] The writing instrument of this invention can be a marker pen or a ballpoint pen.

[0077] Here, in this specification, "marker" refers to a pen having a mechanism that supplies ink stored in an ink reservoir to a resin writing part using capillary action, and also includes pens referred to by those skilled in the art as "signature pens." Additionally, in this specification, "ballpoint pen" refers to a pen having a mechanism that uses the rotation of a ball in the writing part to cause ink stored in an ink reservoir to seep out.

[0078] In particular, when the writing instrument of the present invention is a marker, from the viewpoint of obtaining good ink flow, it is preferable that the writing instrument of the present invention is a valve-type marker that also has a valve mechanism between the ink reservoir and the writing section. Furthermore, in this case, from the viewpoint of suppressing the penetration of the writing section and obtaining sufficient ink flow for writing, it is preferable that the writing instrument of the present invention also has a ring-shaped ink reservoir arranged to surround the writing section. One embodiment of such a valve-type marker will be described with reference to the accompanying drawings.

[0079] like Figure 1As shown, one embodiment 100 of a valve-type marker includes: a writing section 10, an ink reservoir 20, a holding section 30, an ink storage body 40, a valve mechanism 50, an inner cover 60, and an outer cover 70. The following descriptions of each component will be provided with reference to the accompanying drawings.

[0080] <Ink Storage Section>

[0081] The ink storage compartment contains the aforementioned oil-based ink composition for writing instruments.

[0082] The ink storage department can use any unit that stores ink and can supply ink to the writing department.

[0083] From the perspective of preventing ink clogging, it is preferable that the ink storage section is formed by a hollow space. Additionally, as... Figure 1 As shown, from the viewpoint of ensuring uniform dispersion of pigments before use, it is preferable that the ink storage section 20 is sealed with a stir bar 22.

[0084] <Writing Section>

[0085] The writing part can be made of any material depending on the intended use of the writing instrument. When the writing instrument of the present invention is a marker, the writing part can be, for example, made of a fiber core or a plastic core. When the writing instrument of the present invention is a ballpoint pen, the writing part can be a writing part with a ballpoint pen tip at the front end.

[0086] The fiber core is a parallel fiber bundle or felt formed by processing the fiber bundle or the fiber bundle through resin processing, which is a combination of one or more of the following: natural fiber, animal hair fiber, polyacetal resin, acrylic resin, polyester resin, polyamide resin, polyurethane resin, polyolefin resin, polyvinyl resin, polycarbonate resin, polyether resin, and polyphenylene resin.

[0087] <Maintenance Section>

[0088] The holding part can be a section that allows the writing instrument to be held by hand. A holding part such as... Figure 1 As shown, it can be integrated with the ink storage section 20, or it can have a hollow structure (not shown) that exists independently of the ink storage section and can accommodate the ink storage section. The holding section can have, for example, a cylindrical or polygonal cylindrical shape.

[0089] <Ink Storage>

[0090] The ink reservoir is a ring-shaped ink reservoir arranged to surround the writing part. The material constituting the ink reservoir is not particularly limited as long as it is a flexible porous body, such as urethane foam, especially polyether-based urethane foam, polyester-based urethane foam, etc.

[0091] When the writing instrument has an inner cover, the ink reservoir can be configured to fill the gap between the inner cover and the writing part.

[0092] In particular, when using an oil-based ink composition for writing instruments with a high content of particulate components, as in this invention, from the viewpoint of suppressing the permeation of the writing area and obtaining sufficient ink flow for writing, a low density and a high number of pores are preferred.

[0093] More specifically, from the viewpoint of obtaining sufficient ink flow for writing, the preferred density of the ink reservoir is 50 kg / m³. 3 The density is as follows. It was determined according to JIS K7222. The density can be 45 kg / m³. 3 Below, or 40kg / m 3 Additionally, it can be 10 kg / m 3 Above, 15kg / m 3 Above, or 20kg / m 3 above.

[0094] Furthermore, from the viewpoint of increasing the contact area with the writing surface and thereby suppressing ink penetration through the writing surface, it is preferable that the number of pores in the ink reservoir is 40 or more per 25 mm. This number of pores is measured according to JIS K6400-1. The number of pores can be 45 or more per 25 mm, or it can be 100 or less per 25 mm, 90 or less per 25 mm, 80 or less per 25 mm, 70 or less per 25 mm, or 60 or less per 25 mm.

[0095] Valve Mechanism

[0096] like Figure 1 As shown, the valve mechanism 50 includes: a valve seat 52 with sequentially connected openings, a valve body 54 that moves forward and backward relative to the valve seat 52 to open and close, and a spring 56 that applies force to the valve body 54 in the direction of the writing section 10.

[0097] The front end of the valve body 54 abuts against the rear end of the writing section 10. When the writing section 10 moves rearward, the valve seat 52 opens, and ink flows within the valve seat 52, thus supplying ink to the writing section 10. Based on this mechanism, those skilled in the art sometimes refer to the act of moving the writing section back and forth to supply ink to the writing section as "pumping".

[0098] <Inner Cover>

[0099] The inner cover is a hollow cylindrical body that extends through the length of the inner cover and tapers at the front end. The end on the writing section side is also tapered, and a rib supporting the writing section 10 is formed at this end. The writing section 10 is provided within the inner cover 60 and can move back and forth. In addition, the end of the inner cover 60 on the valve mechanism side is a portion that tapers in a stepped manner with the thickest diameter, and this stepped surface has an end edge shape that is inclined relative to the central axis.

[0100] <Outer Cover>

[0101] The outer cover is a component used to cover the writing part. The outer cover may have a structure for fitting into the inner cover or the retaining part.

[0102] Method for manufacturing oil-based ink compositions for writing instruments

[0103] The oil-based ink composition for writing instruments can be manufactured by mixing the pigment, binder resin, organic solvent, and fluorinated resin particles using a stirring device such as a disperser, by a conventionally known method.

[0104] Example

[0105] The present invention will be specifically described with reference to embodiments and comparative examples, but the present invention is not limited thereto.

[0106] Example 1

[0107] 4 parts by weight of dye (Valifast Black 3830, ORIENT CHEMICAL INDUSTRIES CO., LTD.) as a colorant, 4 parts by weight of carbon black tinting agent (average particle size 200 nm) as a pigment, 3 parts by weight of fluorine resin particles (Algoflon L203F, SOLVAY, average particle size 300 nm), 3 parts by weight of rosin-modified maleic acid resin (MALKYD No. 33, Arakawa Chemical Industry Co., Ltd.) as a binder resin, 0.9 parts by weight of nitrocellulose, 3 parts by weight of rosin ester, and 26.0 parts by weight of ethanol and 50.10 parts by weight of propylene glycol monoethyl ether as solvents were mixed by stirring to prepare 100 parts by weight of the oil-based ink composition for writing instruments of Example 1.

[0108] <Examples 2-9 and Comparative Examples 1-4>

[0109] As shown in Tables 1 and 2, the types and amounts of each component were changed. Otherwise, 100 parts by weight of the oil-based ink compositions for writing instruments of Examples 2-9 and Comparative Examples 1-4 were prepared in the same manner as in Example 1. It should be noted that the average particle size of the titanium dioxide toner used here is 400 nm.

[0110] The Making of Writing Instruments

[0111] A marker pen was made by filling the aforementioned oil-based ink composition for writing instruments into a PC-5M (trade name "Posca", lead: round core (polyethylene terephthalate (PET) fiber core) manufactured by Mitsubishi Pencil Co., Ltd. The erasability of this round core was then evaluated.

[0112] Evaluation as an ink composition

[0113] <Abrasion Resistance (KIMWIPER)>

[0114] Based on the description in Patent Document 1, the abrasion resistance of the KIMWIPER was evaluated. Specifically, a pre-made pen was used to write on the surface of a polyethylene terephthalate (PET) film or a SUS board, and the lines were allowed to dry. The KIMWIPER, on which a 500g weight was placed, was moved 5 times to wipe the lines, and the abrasion resistance of the lines was evaluated.

[0115] The evaluation criteria are as follows:

[0116] A: Almost all the lines remain.

[0117] B: 90% of the lines remain.

[0118] C: 80% of the lines remain.

[0119] D: 70% of the lines remain.

[0120] E: The residual rate of the lines is less than 70%.

[0121] <Abrasion Resistance (Steel Wool)>

[0122] The steel wool, on which a 500g weight is placed, is moved 5 times to wipe the lines obtained in the same manner as above, and the abrasion resistance of the lines is evaluated. The evaluation criteria are the same as those described above.

[0123] <Covering>

[0124] Visually inspect the lines to confirm whether the underlying substrate is visible beneath them. Evaluation criteria are as follows:

[0125] A: The base is completely unidentifiable.

[0126] B: The base cannot be clearly seen, but it can be identified.

[0127] C: The base is clearly visible.

[0128] <Viscosity>

[0129] Write using the prepared writing instrument, and evaluate the viscosity based on sensory evaluation. The evaluation criteria are as follows:

[0130] A: The viscosity is such that there are no problems with writing.

[0131] B: The viscosity is slightly problematic in writing.

[0132] C: The degree of viscosity indicating writing problems

[0133] The configuration and evaluation results of the embodiments and comparative examples are shown in Tables 1 and 2:

[0134] [Table 1]

[0135]

[0136] [Table 2]

[0137]

[0138] As can be understood from Tables 1 and 2, the writing instrument oil-based ink compositions of Examples 1 to 9, which contain pigments, binder resins, organic solvents, and fluorinated resin particles, with the mass of the solid components of the writing instrument oil-based ink composition as a reference, a total content of pigments and fluorinated resin particles of 35 to 70% by mass, and a mass ratio of fluorinated resin particles to the total mass of pigments and fluorinated resin particles of 0.10 to 0.45, exhibit better rub resistance than the writing instrument oil-based ink compositions of Comparative Examples 1 to 4.

[0139] Evaluation as a writing tool

[0140] <Evaluation of the production of writing instruments>

[0141] (Example 10)

[0142] exist Figure 1 The writing instrument of Example 10 was made by filling the ink reservoir of the valve-type marker (PC-5M, Mitsubishi Pencil Co., Ltd.) shown with the oil-based ink composition for writing instruments of Example 5. A round core of PET fiber (manufactured by Mitsubishi Pencil Co., Ltd., replacement core PCR-5) was used as the writing part.

[0143] Used as a density of 30±5 kg / m³ 3 Commercially available soft porous materials are used as ink storage bodies for filters made of urethane foam (UF) with 50±5 pores / 25mm.

[0144] (Examples 11-17)

[0145] As shown in Table 3, the writing instruments for Examples 11-17 were made in the same manner as in Example 10, except that the oil-based ink composition and ink reservoir for writing instruments were modified. It should be noted that the oil-based ink composition for writing instruments used in Examples 14-17 was the same as that used in Example 6.

[0146] <evaluate>

[0147] (Ink Flow)

[0148] The writing section of each prepared writing instrument is pressed against the paper and pumped to allow ink to penetrate to the front end of the writing section. Then, in this state, the writing instrument is pumped 30 more times, followed by writing for 250 cm. Evaluation criteria are as follows.

[0149] A: The flow rate is required to obtain a 250cm line without wiping.

[0150] B: The flow rate that, although not wiped, does not achieve a line length of 250cm.

[0151] C: The flow rate to obtain lines with a degree of wiping.

[0152] (The difficulty of writing)

[0153] After evaluating the ink flow rate as described above, with the writing section exposed, the writing instrument was vibrated 30 times along its length, and the transmission of ink through the writing section was observed. Then, the instrument was vibrated 30 times while writing at a distance of 250 cm, and the transmission of ink through the writing section was observed. This process was repeated 50 times. The evaluation criteria are as follows.

[0154] A: There is no transparency or protrusion of the writing section.

[0155] B: The writing section sometimes protrudes towards the front compared to its original position.

[0156] C: Through the writing department.

[0157] The configuration and evaluation results of the embodiments and comparative examples are shown in Table 3.

[0158] [Table 3]

[0159]

[0160] As can be seen from Table 3, a density of 30±5 kg / m³ was used. 3 The writing instruments of Examples 10-12 and 14-16, which use ink storage cells, have good ink flow. Furthermore, it can be understood that the writing instruments of Examples 10 and 14, which use ink storage cells with a cell count of 50±5 per 25mm, also exhibit good ink permeability in the writing section.

[0161] Explanation of reference numerals in the attached figures

[0162] 100 Writing Instruments

[0163] 10. Writing Department

[0164] 20 Ink Storage Department

[0165] 22 Mixing balls

[0166] 30. Maintaining section

[0167] 40 ink storage units

[0168] 50 Valve Mechanism

[0169] 52 Valve seat

[0170] 54 Valve body

[0171] 56 Springs

[0172] 60 Inner Cover

[0173] 70 Outer Cover

Claims

1. An oil-based ink composition for writing instruments, comprising: pigment, binder resin, organic solvent, and fluorinated resin particles. Based on the mass of the solid components of the oil-based ink composition for writing instruments, the total content of the pigment and the fluorinated resin particles is 35-70% by mass. The mass ratio of the fluorinated resin particles to the total mass of the pigment and the fluorinated resin particles is 0.10 to 0.

45. The pigments include metal oxide pigments. When measured using the dynamic light scattering method, the ratio of the average particle size of the metal oxide pigment to the average particle size of the fluorine resin particles is 0.2 to 4.0, and The adhesive resin is selected from one or more of the following: ketone resin, sulfonamide resin, maleic acid resin, terpene resin, terpene phenol resin, rosin ester, xylene resin, alkyd resin, phenolic resin, butyral resin, rosin, polyvinylpyrrolidone, polyvinyl alcohol, acrylic resin, melamine resin, cellulose resin, and rosin-modified maleic acid resin.

2. The oil-based ink composition for writing instruments according to claim 1, wherein, The metal oxide pigment is titanium oxide.

3. The oil-based ink composition for writing instruments according to claim 1 or 2, wherein, The pigments include carbon-based pigments.

4. The oil-based ink composition for writing instruments according to claim 1 or 2, wherein, The fluorinated resin particles are polytetrafluoroethylene particles.

5. A writing instrument comprising at least an ink storage section, a writing section, and a ink retention section. The ink storage compartment contains the oil-based ink composition for writing instruments as described in any one of claims 1 to 4.

6. The writing instrument according to claim 5, wherein, The writing instrument also has a ring-shaped ink reservoir arranged to surround the writing part.

7. The writing instrument according to claim 6, wherein, The density of the ink storage medium, according to JIS K7222, is 50 kg / m³. 3 The following, and according to JIS K6400-1, have a bubble count of 40 or more per 25mm.

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