JP2021116367A - Water-based ink composition for writing instruments - Google Patents

Abstract

To provide a water-based ink composition for writing instruments that has high safety, a wide antibacterial spectrum, and excellent antiseptic effect (antibacterial/antifungal properties) without sacrificing storage stability or writing performance.SOLUTION: A water-based ink composition for writing instruments includes at least particles each of which includes an iodopropargyl compound and has a shell composed of cyanoacrylate. The particles preferably have an average particle size of 10-800 nm, and the iodopropargyl compound preferably has at least 3-iodo-2-propynyl butylcarbamate.SELECTED DRAWING: None

Description

The present invention relates to a water-based ink composition for writing utensils, which is highly safe, has a wide antibacterial spectrum, and has an excellent antiseptic effect (bactericidal and antifungal properties) without impairing storage stability and writing performance.

Conventionally, some materials have been known as preservatives and the like used in water-based ink compositions for writing tools.
For example, (1) (pigment and pigment dispersant) and / or a colorant consisting of a resin emulsion colorant, a water-soluble organic solvent, a pseudoplasticity-imparting agent, and a water-based ink basic composition consisting of water and the weight of the water-based ink basic composition. An ink composition for an aqueous ball pen containing 0.05 to 0.5% by weight of a crosslinked acrylic acid polymer salt and further containing a preservative such as 1,2-benzisothiazolin-3-one (for example, Patent Document 1). reference),
(2) An aqueous ink composition obtained by finely dispersing a water-insoluble coloring material and a fine particle resin composition in an aqueous medium, wherein the fine particle resin composition is made of an oil-soluble antibacterial fungicide and a water-insoluble polymer. Aqueous ink composition characterized by (see, for example, Patent Document 2).
It consists of (3) water, a water-soluble organic solvent, (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color reaction of both of them occurs. A reversible thermochromic microcapsule pigment containing a reversible thermochromic composition, a comb-shaped polymer dispersant having a carboxyl group in the side chain, a water-soluble resin, a sugar alcohol having 3 or more carbon atoms, and cationic. A reversible thermochromic water-based ink composition comprising an antiseptic having the above (see, for example, Patent Document 3).
(4) A water-based ink composed of at least a colorant, water, a polyhydric alcohol, and an antiseptic and antifungal agent, characterized in that the antiseptic and antifungal agent contains 3-iodo-2-propynylbutylcarbamate. Water-based ink (see, for example, Patent Document 4),
Etc. are known.

On the other hand, examples of the antibacterial / antiseptic composition include (5) microcapsules containing at least one iodopropargyl compound, wherein the at least one iodopropargyl compound contains at least one melamine-formaldehyde polymer. Microcapsules (see, eg, Patent Document 5), which are microencapsulated using a microencapsulating material that contains.
(6) Sterilization and antiseptic of iodine-based compounds (3-iodo-2-propynylbutylcarbamate: IPBC), triazole-based compounds, carbamoylimidazole-based compounds, dithiol-based compounds, isothiazoline-based compounds, nitroalcohol-based compounds, paraoxybenzoic acid esters, etc. Hydrophobic antibiotics selected from insect repellents such as algae and fungi, pyrethroid compounds, neonicotinoid compounds, organic chlorine compounds, organic phosphorus compounds, carbamate compounds, oxadiadin compounds, and insecticides. A hydrophobic solution is prepared by dissolving the active compound with a hydrophobic polymerizable vinyl monomer, water and an emulsifier are mixed to prepare an emulsifier aqueous solution, and the hydrophobic solution is emulsified in the emulsifier aqueous solution. The polymerizable vinyl monomer is subjected to mini-emulsion polymerization in the presence of a polymerization initiator to produce a polymer containing an antibiotic-active compound and having an average particle size of less than 1 μm. Sex particles (see, for example, Patent Document 6) and the like are known.

However, the water-based ink compositions for writing tools, preservatives, and the like described in Patent Documents 1 to 6 are limited in amount due to safety problems, have some adverse effect on other ink materials, or , There are problems such as insufficient effect on specific pollution sources.

JP-A-8-48929 (Claims, Examples, etc.) JP-A-2002-138231 (Claims, Examples, etc.) Japanese Unexamined Patent Publication No. 2015-10125 (Claims, Examples, etc.) JP-A-2015-196745 (Claims, Examples, etc.) Japanese Patent Application Laid-Open No. 2017-507952 (Claims, Examples, etc.) Japanese Unexamined Patent Publication No. 2013-151471 (Claims, Examples, etc.)

The present invention is intended to solve this problem in view of the above-mentioned problems of the prior art, has high safety, has a wide antibacterial spectrum, and has an antiseptic effect (prevention) without impairing storage stability and writing performance. It is an object of the present invention to provide a water-based ink composition for writing utensils having excellent fungal and antifungal properties.

As a result of diligent research in view of the above-mentioned conventional problems and the like, the present inventors have obtained particles in which at least a compound having specific antibacterial and antifungal properties is contained and the shell is composed of a specific polymer. It has been found that a water-based ink composition for writing utensils of the above-mentioned object can be obtained by containing the ink, and the present invention has been completed.

That is, the water-based ink composition for writing tools of the present invention is characterized in that it contains at least an iodopropargyl compound and the shell contains particles composed of cyanoacrylate.
The average particle size of the particles is preferably 10 to 800 nm.
The iodopropargyl compound preferably contains at least 3-iodo-2-propynylbutylcarbamate.
The mass ratio of the cyanoacrylate constituting the shell is preferably 90 to 100% by mass.
The cyanoacrylate preferably contains at least one selected from isobutyl cyanoacrylate, n-butyl cyanoacrylate, tert-butyl cyanoacrylate, n-octyl cyanoacrylate, and 2-octyl cyanoacrylate.

According to the present invention, a water-based ink composition for writing utensils having high safety, a wide antibacterial spectrum, and excellent antiseptic effect (bactericidal and antifungal properties) without impairing storage stability and writing performance can be obtained. Provided.

Hereinafter, embodiments of the present invention will be described in detail.
The water-based ink composition for writing tools of the present invention is characterized by containing at least an iodopropargyl compound and a shell containing particles composed of cyanoacrylate.

Examples of the iodopropargyl compound used in the present invention include 3-iodo-2-propynylpropyl carbamate, 3-iodo-2-propynylbutyl carbamate (IPBC), 3-iodo-2-propynyl m-chlorophenyl carbamate, and 3-iodo. -2-Propinylphenylcarbamate, 3-iodo-2-propynyl 2,4,5-trichlorophenyl ether, 3-iodo-2-propynyl 4-chlorophenylformal (IPCF), di- (3-iodo-2-propynyl) Hexyldicarbamate, 3-iodo-2-propynyloxyethanolethyl carbamate, 3-iodo-2-propynyloxyethanolphenyl carbamate, 3-iodo-2-propynyl thioxothioethyl carbamate, 3-iodo-2-propynyl carbamate Ester (IPC), N-iodopropargyloxycarbonylalanine, N-iodopropargyloxycarbonylalanine ethyl ester, 3- (3-iodopropargyl) benzoxazole-2-one, 3- (3-iodopropargyl) -6-chloro Benzoxazole-2-one, 3-iodo-2-propynyl alcohol, 4-chlorophenyl 3-iodopropargylformal, 3-bromo-2,3-diiodo-2-propenylethylcarbamate, 3-iodo-2-propynyl-n Included are at least one selected from −hexyl carbamate, 3-iodo-2-propynylcyclohexyl carbamate, etc. (each alone or a mixture of two or more, and so on).

These iodopropargyl compounds themselves are conventionally known, highly safe, antibacterial and antifungal compounds, and their production methods are also known, and they should be prepared by various production methods. And if there are commercial products, they can be used.
In the present invention, from the viewpoint of safety, stability, etc., preferably, those containing at least 3-iodo-2-propynylbutylcarbamate (hereinafter, may be simply referred to as "IPBC") (IPBC alone or IPBC). Mixture containing) is preferred.

In the present invention, the particles having the above constitution contain at least the iodine propargyl compound and the shell is composed of cyanoacrylate. For example, the polymer represented by the following formula (I) is used as a shell for iodopropargyl. It can be produced by encapsulating a compound.

Examples of the alkyl group having 2 to 8 carbon atoms of R in the general formula (I) include an ethyl group, a propyl group (straight chain, branched), a butyl group (straight chain, branched), and a pentyl group (straight chain, branched). Branch), hexyl group (linear, branched), heptyl group (linear, branched), octyl group (linear, branched), etc., preferably used as an adhesive for suturing wounds in the surgical field. Alkyl groups having 4 carbon atoms and octyl groups having 8 carbon atoms are preferable, and isobutyl groups, n-octyl groups and 2-octyl groups are particularly preferable.
Specifically, at least one selected from isobutyl cyanoacrylate, n-butyl cyanoacrylate, tert-butyl cyanoacrylate, n-octyl cyanoacrylate, and 2-octyl cyanoacrylate from the viewpoint of further exerting the effects of the present invention. It is desirable to configure it with one containing.
The mass ratio of the cyanoacrylate constituting the shell is preferably 90 to 100% by mass from the viewpoint of safety and stability.

The particles of the present invention are composed of a cyanoacrylate polymer containing the iodine propargyl compound and having a shell having a structure represented by the general formula (I) in a repeating unit. In these particles, cyanoacrylate itself adheres to the cell wall of bacteria, interferes with cell wall synthesis, causes lysis, and inhibits the growth of bacteria (including molds), thereby independently having an antibacterial effect (antibacterial and antibacterial). In addition, in the present invention, the iodopropargyl compound itself contained in the particles is highly safe and has an antibacterial effect as described above, and due to these synergistic actions, It is highly safe, has a wide antibacterial spectrum, is excellent in stability, and has an excellent antibacterial effect (including an antifungal effect) (these points will be described in detail in Examples and the like described later).

In the production of the particles, for example, when the structural unit (monomer) represented by the general formula (I) is polymerized by anionic polymerization, the iodopropargyl compound is added to form the iodopropargyl compound inside the particles. By encapsulation (conjugation), it is obtained as an aqueous dispersion containing the particles.
A polymerization agent can be used to initiate the polymerization and stabilize the polymerization. Examples of this polymerization agent include at least one sugar selected from the group consisting of polyoxyethylene sorbitan fatty acid ester, monosaccharide having a hydroxyl group and disaccharide.

Examples of the polyoxyethylene sorbitan fatty acid ester that can be used include polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, and polyoxyethylene sorbitan oleate.
Further, by using sugar as a polymerization agent separately from the above-mentioned polyoxyethylene sorbitan fatty acid ester, the effect can be further enhanced.
The sugar that can be used may be any monosaccharide or disaccharide having a hydroxyl group, and preferred examples thereof include glucose, mannose, ribose, fructose, maltose, trehalose, lactose and sucrose. These sugars may be in either a cyclic or chain form, and in the case of a cyclic form, they may be in either a pyranose type or a furanose type. Further, although various isomers are present in sugar, any of them may be used. Usually, monosaccharides exist in the form of pyranose type or furanose type, and disaccharides are those in which they are α-bonded or β-bonded, and sugars in such a normal form can be used as they are. The monosaccharide and disaccharide can be used alone or in combination of two or more.

Water (distilled water, purified water, pure water, etc.) is usually used as the solvent for the polymerization reaction. Since anionic polymerization is initiated by hydroxide ions, the pH of the reaction solution affects the polymerization rate. When the pH of the reaction solution is high, the concentration of hydroxide ions is high, so that the polymerization is fast, and when the pH is low, the polymerization is slow. Usually, an appropriate polymerization rate can be obtained under acidic conditions having a pH of about 2 to 4. The acid added to acidify the reaction solution is not particularly limited, but phosphoric acid, hydrochloric acid, acetic acid, phthalic acid, citric acid and the like, which do not adversely affect the reaction, can be preferably used.

The concentration of the structural unit represented by the above formula (I) in the polymerization reaction solution at the start of the reaction is not particularly limited, but is usually about 0.1 to 10% by mass, preferably about 1 to 5% by mass. be. The concentration of the polymerization agent in the polymerization reaction solution at the start of the reaction (the total concentration when a plurality of types are used) is not particularly limited, but is usually 1 to 30% by mass, preferably about 5 to 20% by mass. be. The reaction temperature is not particularly limited, but it is convenient and preferable to carry out the reaction at room temperature. The reaction time is not particularly limited, but is usually about 0.5 to 4 hours. The polymerization reaction is preferably carried out under stirring. Since the particles are usually used as neutral particles, it is preferable to add a base such as an aqueous sodium hydroxide solution to the reaction solution to neutralize the particles after the reaction is completed.

By the above polymerization reaction, the structural unit represented by the above formula (I) is anionically polymerized to generate polymer particles having the structure represented by the above formula (I) in the repeating unit, and the above-mentioned particles are inside the particles. It contains (conjugates) an iodopropargyl compound.
The amount of the iodine propargyl compound to be encapsulated (conjugated) can be appropriately set according to the use of the antibacterial agent, the dose required at the time of use, and the like. For example, it is about 0.1 to 35% by mass with respect to the total amount of particles, but is not limited to these ranges.
The average particle size of the particles obtained by the above method is not particularly limited, but is preferably less than 1000 nm (1 μm), more preferably 10 to 800 nm, particularly from the viewpoint of dispersion stability and surface area. Preferably, it is 10 to 200 nm.
The average particle size can be adjusted by adjusting the concentration of the structural unit represented by the above formula (I) in the reaction solution, the type of polymerization agent to be used and the amount thereof, the reaction time, and the like. If necessary, the generated particles can be recovered by a conventional method such as centrifugal ultrafiltration.
The "average particle size" defined in the present invention is a histogram average particle size based on the scattered light intensity distribution. In the present invention (including examples described later), a particle size distribution measuring device [FPAR1000 (manufactured by Otsuka Electronics Co., Ltd.)] ], It is the value of _{D 50 measured.}

The obtained particles have the antibacterial / antifungal effect and iodine of the particles alone by encapsulating (conjugating) the above-mentioned iodopropargyl compound in the polymer particles having the structure represented by the above general formula (I) in the repeating unit. The amount of iodine propargyl compound used can be reduced as much as possible due to the integrated action (synergistic action) of the propargyl compound such as the antibacterial effect, and even if the iodine propargyl compound has insufficient effect on a specific pollution source, both of the above. Due to the integrated action (synergistic action) of iodine, it is possible to exhibit high safety, excellent storage stability, and excellent antibacterial properties (including antifungal effect).

The particles having the above characteristics can be used alone or in combination of two or more, and the (total) content of the active ingredient thereof is 0.1 to 30% by mass, preferably 0.1 to 30% by mass, based on the total amount of the ink composition. , 0.1 to 10% by mass is desirable.
In the present invention, the "active ingredient" refers only to an ingredient that exhibits an antiseptic effect (antibacterial and antifungal properties), and refers to a polymerization agent (polyoxyethylene sorbitan fatty acid ester or sugar), water, or the like used for the above polymerization. The active ingredient is a particle itself that does not contain each component and does not contain a polymerization agent or the like, and an iodopropargyl compound contained in the particle.
If the content of this active ingredient is less than 0.1% by mass, the effect of the present invention cannot be exhibited, while if it exceeds 30% by mass, the dispersion stability is likely to be impaired, which is not preferable. ..

In addition to the particles having the above characteristics, the water-based ink composition for writing tools of the present invention contains a general-purpose colorant and a water-soluble solvent in the water-based ink for writing tools.
As the colorant that can be used, water-soluble dyes and pigments, for example, inorganic pigments, organic pigments, plastic pigments, hollow resin particles having voids inside the particles are used as white pigments, or dyes having excellent color development and dispersibility. Resin particles dyed with (pseudo-pigment) and the like can also be used.
As the water-soluble dye, any of a direct dye, an acid dye, an edible dye, and a basic dye can be used in an appropriate amount as long as the effects of the present invention are not impaired.

Examples of the water-soluble solvent that can be used include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, 3-butylene glycol, thiodiethylene glycol, and glycerin, and ethylene glycol monomethyl ether and diethylene glycol monomethyl ether. , Glycol ethers such as propylene glycol monomethyl ether can be used alone or in combination. The content of this water-soluble solvent is preferably 5 to 40% by mass in the total amount of the water-based ink composition for writing tools.

In addition to the particles, colorants, and water-soluble solvents having the above characteristics, the water-based ink composition for writing tools of the present invention contains water as a solvent (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.). In addition, a dispersant, a lubricant, a pH adjuster, a rust preventive, a thickener, an evaporation inhibitor, a surfactant and the like can be appropriately contained as long as the effects of the present invention are not impaired.
As the dispersant that can be used, nonionic, anionic surfactant and water-soluble resin are used. A water-soluble polymer is preferably used.
As lubricants, nonionics such as fatty acid esters of polyhydric alcohols, higher fatty acid esters of sugars, polyoxyalkylene higher fatty acid esters, and alkylphosphates, which are also used as surface treatment agents for pigments, and alkylsulfonic acids of higher fatty acid amides. Examples thereof include salts, anionic compounds such as alkylallyl sulfonates, derivatives of polyalkylene glycols, fluorine-based surfactants, and polyether-modified silicones.

Acidity regulators include ammonia, urea, monoethanoamine, diethanolamine, triethanolamine, sodium tripolyphosphate, sodium carbonate and other carbonates, alkali metal salts of phosphoric acid, and alkali metal hydrates such as sodium hydroxide. And so on. Examples of the rust preventive include benzotriazole, tolyltriazole, dicyclohexylammonium nitrate, saponins and the like.
Examples of the thickener include carboxymethyl cellulose (CMC) or a salt thereof, fermented cellulose, crystalline cellulose, polysaccharide and the like. Examples of polysaccharides that can be used include xanthan gum, guar gum, hydroxypropylated guar gum, casein, arabic gum, gelatin, amylose, agarose, agaropectin, arabinan, curdran, curose, carboxymethyl starch, chitin, chitosan, and quince seed. , Glucomannan, gellan gum, tamarind seed gum, dextran, nigeran, hyaluronic acid, pustulan, funoran, HM pectin, porphyran, laminaran, likenan, carrageenan, alginic acid, tragacanth gum, alkathy gum, succinoglycan, locust bean gum, tara gum, etc. These may be used alone or in combination of two or more. Moreover, if these commercial products are available, they can be used.
Examples of the evaporation inhibitor include pentaerythritol, p-xylene glycol, trimethylolpropane, trimethylolpropane, dextrin and the like.
Examples of the surfactant include fluorine-based, silicone-based, and acetylene glycol-based surfactants.

The water-based ink composition for writing instruments of the present invention is a homomixer, a homogenizer, in which particles having the above characteristics, a water-soluble solvent, and other components are appropriately combined according to the use of ink for writing instruments (for ballpoint pens, marking pens, etc.). Alternatively, the water-based ink composition for writing instruments can be prepared by stirring and mixing with a stirrer such as a disper, and if necessary, removing coarse particles in the ink composition by filtration or centrifugation.

The pH (25 ° C.) of the water-based ink composition for writing utensils of the present invention can be adjusted to 5 to 10 depending on a pH adjuster or the like from the viewpoints of usability, safety, stability of the ink itself, and matching with the ink container. It is preferably adjusted, and more preferably 6 to 9.5.

The water-based ink composition for writing instruments of the present invention is mounted on a ballpoint pen, a marking pen, or the like having a pen tip such as a ballpoint pen tip, a fiber tip, a felt tip, or a plastic tip.
As the ballpoint pen, the water-based ink composition for writing instruments having the above composition is housed in a ballpoint pen ink container (refill) having a ball having a diameter of 0.18 to 2.0 mm, and the water-based ink is contained in the ink container. Examples thereof include substances that are incompatible with the ink composition and have a small specific gravity with respect to the water-based ink composition, for example, polybutene, silicone oil, mineral oil, and the like, which are contained as ink followers.
The structure of the ballpoint pen and the marking pen is not particularly limited, and for example, a collector structure (ink holding mechanism) in which the shaft cylinder itself is used as an ink container and the shaft cylinder is filled with the water-based ink composition for writing tools having the above configuration. It may be a direct liquid type ballpoint pen or a marking pen provided.

In the water-based ink composition for writing tools of the present invention configured as described above, since the particles having the above-mentioned characteristics to be used are blended in the water-based ink composition for writing tools, the antiseptic effect (antibacterial effect) in the ink composition. It is suitable for writing tools such as ballpoint pens and marking pens because it can exhibit (property and antifungal properties), has a long-lasting effect for a long period of time, and these particles do not impair storage stability and writing performance. A water-based ink composition for use will be obtained.

Next, the present invention will be described in more detail with reference to Production Examples, Examples and Comparative Examples, but the present invention is not limited to the following Examples and the like.

[Production Examples 1 to 7: Production of Particles A to G]
Each particle A to G was produced according to the following Production Examples 1 to 7. The following "parts" represent parts by mass.

(Production Example 1: Production of Particle A)
A stirrer, a reflux condenser, and a thermometer were attached to a 2 liter flask and set in a water tank. 89.8 parts of distilled water, 2 parts of polyoxyethylene sorbitan monolaurate (20EO), 0.2 parts of phosphoric acid. , 6 parts of iso-butyl monomer and 2 parts of iodopropargyl compound: 3-iodo-2-propynylbutylcarbamate were charged with R in the formula (I), and the mixture was stirred for about 15 minutes to complete the anion polymerization. A dispersion liquid (particle A) was obtained. The average particle size of the particles was 83 nm.

(Production Examples 2 to 7: Production of particles B to G)
With the compounding composition shown in Table 1 below, dispersion liquids (particles B to G) of each particle were obtained in the same manner as in Production Example 1 above. The average particle size of each particle is shown in Table 1 below.

(Examples 1 to 7 and Comparative Example 1)
Using the particles A to G of Production Examples 1 to 7 obtained above, the compounding composition (particles A to G, colored resin fine particles, triethanolamine, ethylene glycol, distilled water) shown in Table 2 below is used in a conventional method. Obtained a water-based ink composition for writing tools. As the particles A to G, each dispersion (particle) obtained by concentrating the dispersion of each particle to 25% by mass of the active ingredient was used. Comparative Example 1 is a water-based ink composition for writing tools having a compounding composition that does not contain the particles A to G.

As the colored resin fine particles, a colored resin fine particle dispersion obtained by the following production method was used.
(Manufacturing of colored resin fine particles)
A stirrer, a reflux condenser, a thermometer, a nitrogen gas introduction tube, and a 1000 ml separatory funnel for adding a monomer are attached to a 2 liter flask, set in a hot water tank, 500 g of distilled water, and a polymerizable surfactant [manufactured by Adeca]. “Adecaria Soap SE-10N”] 50 g and 3 g of ammonium persulfate were charged, and the internal temperature was raised to 50 ° C. while introducing nitrogen gas.
On the other hand, a water-soluble base is added to 500 g of a mixed monomer composed of 300 g of -2-methacryloyloxyethyl phthalate [manufactured by Mitsubishi Rayon Co., Ltd., acrylic ester PA) as a monomer and 200 g of n-butyl methacrylate as another monomer. A solution prepared by mixing 40 g of a sex dye [“AIZEN CATHILON RED BLH 200%” manufactured by Hodoya Chemical Industry Co., Ltd.] was prepared.
This prepared liquid was added from the separating funnel into the flask kept at a temperature of about 50 ° C. for 3 hours with stirring, and emulsion polymerization was carried out. Further, the mixture was aged for 5 hours to complete the polymerization to obtain a dispersion liquid (particles) of colored resin fine particles for water-based ink. The average particle size of the colored resin fine particles was 80 nm, and the resin solid content was 30% by mass.
The obtained water-based ink composition for writing tools (total amount 100% by mass) was evaluated for antibacterial properties by the following evaluation method.
These results are shown in Table 2 below.

[Test method for antiseptic effect (antibacterial and antifungal properties)]
The following microbial test methods were performed in accordance with ISO 11930: 2012 (procedures for interpreting data generated by conservative efficacy testing and / or microbiological risk assessment).
A challenge test was conducted with the following three groups of bacteria, yeast, and filamentous fungi.
Bacterial population: Stapylococcus aureus NBRC13276, Escherichia coli NBRC3972
Yeast: Candida albicans NBRC1594
Aspergillus brasiliensis

<Preparation of inoculum solution>
Preparation of inoculated bacterial solution: The bacterial solution was prepared according to ISO 11930: 2012.
Bacterial group: Bacterial solution was prepared according to ISO 11930: 2012 for each bacterial species. ^{Three types of bacterial solutions adjusted to 1 × 10 7} to 1 × 10 ⁸ cfu / ml for each bacterial species were mixed in equal amounts to prepare an inoculated bacterial solution.
Yeast: According to ISO 11930: 2012, the bacterial solution was prepared so as to be ^{1 × 10 6} to 1 × 10 ^{7 cfu / ml.}
Filamentous fungi: According to ISO 11930: 2012, the bacterial solution was prepared so as to be ^{1 × 10 6} to 1 × 10 ^{7 cfu / ml.}
<Inoculation>
The ink composition for writing utensils was inoculated with a bacterial solution in an amount of 1% by mass.
<storage>
The inoculated ink composition for writing utensils was stored at a temperature of 22.5 ± 2.5 ° C. and detected and cultured every specified period.

<Detection culture>
Bacterial group is SCD agar medium, yeast is SD agar medium, filamentous fungus is smeared on 10 sheets in total of 1 g, bacterial group and yeast are 32.5 ° C. for 2 days, filamentous fungus is 22.5 Incubated at ° C for 5 days.
<Evaluation criteria>
A: No colonies appear on the 7th day.
B: No colonies appear on the 21st day.
C: As of the 28th day, several to dozens of colonies have appeared.
D: As of the 28th, there is a clear increase.

Considering Tables 1 and 2 above, the water-based ink composition for writing tools of Examples 1 to 7 containing the particles A to G of the present invention is a water-based ink composition for writing tools of Comparative Example 1 which is outside the scope of the present invention. It was found that the antiseptic effect (antibacterial and antifungal properties) was superior to that of the product.
Further, the water-based ink compositions for writing tools of Examples 1 to 7 were placed in a closed container and stored at 26 ° C. for 3 months, and then the agglomerates and the like were visually evaluated by sensory analysis. As a result, there was no agglomeration of particles and the like. , It was found that there is no problem with storage stability.

Further, a water-based marking pen was produced using each of the writing tool ink compositions of Examples 1 to 7 after the storage stability evaluation. Specifically, a marking pen [manufactured by Mitsubishi Pencil Co., Ltd., trade name: Propass Window PUS-102T, pen tip, thick: PE resin, fine: PET fiber] is filled with each of the above water-based inks to prepare a marking pen. did. Using each of the obtained marking pens, 10-round spiral writing was performed so as to continuously draw a circle with a diameter of about 2 cm on PPC paper, and it was found that writing was good without blurring and there was no problem in writing performance. ..

A water-based ink composition for writing instruments suitable for writing instruments such as marking pens and ballpoint pens can be obtained.

Claims (5)

A water-based ink composition for writing utensils, which comprises at least an iodopropargyl compound and whose shell contains particles composed of cyanoacrylate. The water-based ink composition for writing tools according to claim 1, wherein the average particle size of the particles is 10 to 800 nm. The water-based ink composition for writing tools according to claim 1 or 2, wherein the iodine propargyl compound contains at least 3-iodo-2-propynylbutylcarbamate. The water-based ink composition for writing tools according to any one of claims 1 to 3, wherein the cyanoacrylate constituting the shell is 90 to 100% by mass in mass ratio. Claims 1 to 4, wherein the cyanoacrylate contains at least one selected from isobutyl cyanoacrylate, n-butyl cyanoacrylate, tert-butyl cyanoacrylate, n-octyl cyanoacrylate, and 2-octyl cyanoacrylate. The water-based ink composition for writing tools according to any one of them.