JP3451122B2 - Aqueous ink composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based ink composition, and more particularly to a water-based ink composition for paintings used by infants and lower grades, or a water-based ink composition for general writing instruments.

[0002]

2. Description of the Related Art In recent years, where ecology has become a problem, the safety of coloring materials, solvents and the like is also required in ink compositions for writing instruments and the like. At present, water-based ink compositions used for marking pens, ballpoint pens, etc., contain water-soluble dyes and water as essential components and, if necessary, additives such as solvents, surfactants, pH adjusters and preservatives. The product can be easily prepared by adding In general, the water-based ink composition is less likely to cause a danger to the human body than the oil-based ink composition containing a highly toxic volatile component. Therefore, the material for the water-based ink composition has been selected mainly from the viewpoint of performance and price as an ink, and has never been selected from the viewpoint of safety.

By the way, in a water-based ink composition, harmful bacteria are generated and propagate in a writing instrument if the conditions are met.
Greatly affects the performance of the product itself (poor writing, odor, etc.)
In addition to the effects on the human body, there is a risk that the spores of mold will be scattered and the infants' mouths will be adversely affected.

Therefore, in the conventional water-based ink composition, an antibacterial effect against harmful bacteria (mold and bacteria) is imparted by adding a preservative. This antiseptic suppresses or kills the generation of harmful bacteria, but many of them have high antibacterial effect and are harmful not only to harmful bacteria but also to the human body. Under these circumstances, as a safe aqueous ink composition, a dye as an essential component and an additive such as a solvent, a surfactant, an antiseptic, etc., which are optionally added, are all food additives and / or their compatibility. A water-based ink composition consisting of a product has already been filed (JP-A-4-298577 and JP-A-4-318081).
Issue).

However, the official standard for food additives (No. 6)
Edition), the water-based ink composition consisting of
There is a problem in that the antibacterial effect is also reduced due to the change in hue and the dissolution stability of the preservative. Also, compared to food,
Due to the low solubility of water in water-based marking pen inks that are directly affected by harmful bacteria depending on storage and usage conditions, antibacterial agents effective against harmful bacteria specified in the Food Additives Standard are low in water. However, there is a problem that it is practically impossible to add a bacteriostatic agent for completely suppressing and sterilizing harmful bacteria with the composition of only those specified in the official standard for food additives.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to solve the above conventional problems, and an object thereof is to provide an aqueous ink composition having excellent stability over time and antibacterial effect against harmful bacteria. And

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned conventional problems, the present inventors have decided to use the materials for water-based ink compositions as official standards for food additives (6th edition) As a result of diligent research conducted by selecting from those specified in (Second Edition), the performance is more satisfactory than the conventional water-based ink composition, and the stability over time and the antibacterial effect against harmful bacteria are excellent. It succeeded in obtaining an aqueous ink composition and completed the present invention.

That is, the aqueous ink composition of the present invention comprises
Dye and, if necessary, solvent, surfactant,
A water-based ink composition in which additives such as preservatives are all food additives and compatible products, and in addition to containing propylene glycol and para-oxybenzoic acid ester, it also contains phenoxyethanol stipulated in the cosmetic product type permission standard. And In the above water-based ink composition, the content of propylene glycol is 10.0.
It is preferable that the content of paraoxybenzoic acid ester is 0.01 to 1.0% by weight, and the content of phenoxyethanol is 1.0 to 10.0% by weight.

[0009]

The present invention is a water-based ink composition in which a dye and an additive such as a solvent, a surfactant and an antiseptic which are optionally added are food additives and compatible products thereof, and propylene glycol is added. It is composed by containing three components of paraoxybenzoic acid ester and phenoxyethanol specified in the cosmetic product type permission standard, and stabilization of physical properties over time (due to pH change by the synergistic effect of the above three components). It is based on the new fact that it can exert the effect of enhancing the change of hue) and the antibacterial activity against harmful bacteria (preservation of antiseptic in ink system = stability of antibacterial effect), and each component is partially Even if combined, the object of the present invention cannot be achieved. (This point will be described in detail in Examples and the like described later).

The contents of the present invention will be described in detail below. In the present invention, dyes and additives such as solvents, surfactants, and preservatives that are added as required are all described in food additives and compatible products (Food Additives Official Book (6th Edition)). The water-based ink composition of the present invention comprises three components of propylene glycol, paraoxybenzoic acid ester, and phenoxyethanol specified in the cosmetic product type permission standard.

The dye as an essential component used in the aqueous ink composition of the present invention is a legal dye defined as a colorant for food additives, for example, food red Nos. 2, 3, 102.
No. 104, 105, 106, edible yellow No. 4, 5
Natural dyes such as food dyes such as No. 1, food blue No. 1 and 2, turmeric dye (yellow), publica dye (orange), cochineal dye (red), gardenia blue (blue), etc. can be used. Most colors can be prepared by appropriately mixing these food dyes and / or legal dyes of natural dyes.

In the water-based ink composition of the present invention, the solvent, which is optionally added, does not have sufficient ink performance by only dissolving the legal dye used as the above dye in water, and the moisture retention and dissolution stability are improved. It is used for the purpose of adjusting viscosity. As this solvent, for example, glycerin, which is specified in the official compendial document for food additives (6th edition),
D-sorbit solution or the like can be used.

Further, the surfactant added as necessary is used for improving the wettability, and this surfactant is used as an emulsifier in the official standard for food additives (6th edition). As specified, for example, glycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester and the like can be used.

Further, harmful ink bacteria (bacteria, mold)
Antibacterial agents and antifungal agents against are defined in the official standard for food additives (4th edition), for example, devidroacetic acid,
Sodium devidroacetate, sorbic acid, potassium sorbate, benzoic acid, sodium benzoate, propionic acid,
Sodium propionate and the like can be used, and they can be used alone or as a mixture of two or more.

Propylene glycol in the present invention is
It is specified in the official compendial document for food additives (6th edition), and it mixes well with water, alcohol, and other organic solvents in any proportion,
In addition, since it dissolves various organic compounds, it acts as a solvent for coloring agents, preservatives, etc., and also has fungi, bacteriostatic action of bacteria (fermentation inhibition, antifungal action), and moisturizing action.
It is used for the purpose of imparting these effects. The content of propylene glycol is 10.
0 to 30.0% by weight, preferably 20.0 to 30.0
% By weight. The propylene glycol content is 10.
If it is less than 0% by weight, the solubility of the paraoxybenzoic acid ester will be lowered, and if it exceeds 30.0% by weight, the viscosity of the ink will be high and writing defects will occur, which is not preferable.

The paraoxybenzoic acid ester (eg, ethyl, propyl, butyl, isobutyl, isopropyl, etc.) in the present invention is a food additive compendial document (No. 6).
It is used for the purpose of imparting antiseptic and antifungal action. It should be noted that the paraoxybenzoic acid ester is preferably used as a mixture rather than used alone in order to enhance the water solubility. The content of paraoxybenzoic acid ester is 0.01 to 1.0% by weight, preferably 0.05 to 1.0% by weight. When the content of the paraoxybenzoic acid ester is less than 0.01% by weight, the bacteriostatic action on mold and bacteria is reduced, and 1.0
If it exceeds 5% by weight, needle-like crystals are liable to occur, which causes writing defects, which is not preferable.

Phenoxyethanol [C used in the present invention
₆ H ₅ OCH ₂ CH ₂ OH] is defined in the cosmetic product type permission standard (second edition) (when quantified, it contains 96.0% or more of 2-phenoxyethanol), and its safety is It has been confirmed. This phenoxyethanol is limited to those specified in the cosmetics product type permission standard (second edition). The reason is that the industrial phenoxyethanol and the phenoxyethanol have different purities. The phenoxyethanol used in the present invention, in addition to the generally known antibacterial action, further improves the action effects of the above-mentioned propylene glycol and paraoxybenzoic acid ester, and stabilizes the physical properties over time, which is the object of the present invention (due to pH change). It is used in order to achieve a change in hue) and an antibacterial activity against harmful bacteria (prevention of deactivation of antiseptic in ink system = stability of antibacterial effect). The content of phenoxyethanol is 1.0 to 10.0% by weight, preferably 1.0 to 5.0% by weight. If the content of phenoxyethanol is less than 1.0% by weight, the antibacterial action and stability over time decrease, and if it exceeds 10.0% by weight, it becomes insoluble in water, which is not preferable.

In the aqueous ink composition of the present invention, all the dyes as essential components and additives such as solvents to be added as required are described in the official compendial document for food additives (4th edition). By selecting from the items, for paintings used by young children and lower grades, or for water-based marking pens,
It is possible to prepare water-based ink compositions for various applications such as ballpoint pens and other general writing instruments.

[0019]

EXAMPLES Next, the present invention will be described more specifically and in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. (Example 1, Comparative Examples 1 to 3)

The respective components of Example 1 and Comparative Examples 1 to 3 were mixed at the compounding ratios shown in Table 1 below and stirred for 5 hours to give a red aqueous ink composition (aqueous marking pen ink composition). Were prepared respectively. Comparative Example 1
Is obtained by excluding only phenoxyethanol of Example 1, Comparative Example 2 is obtained by excluding only propylene glycol of Example 1, and Comparative Example 3 is obtained by excluding paraoxybenzoic acid ester of Example 1 (ethyl, Propyl, butyl)
Only the ones are excluded. Next, each of the red aqueous ink compositions prepared in Example 1 and Comparative Examples 1 to 3 was stored in a constant temperature bath at 50 ° C and -10 ° C for 3 months, and then the stability of each ink composition with time ( The results of comparison of pH value, color change, solid matter deposition) and antibacterial properties are shown in Table 2 below.

The evaluation of each item in Examples and Comparative Examples was measured by the methods shown below. The color change is
The following two items were comprehensively judged. One is the same lot of writing paper (JIS P3201 Writing paper A grammage)
In 28.5), a spiral is written on the product, and the difference in hue from the initial stage is visually determined. On the other hand, depending on the product, the ink was extracted, and the color was applied to AH Kent paper (JIS 3301 drawing paper A basis weight 200) with a bar coater (wire diameter 0.6 mm). / C measurement.

Precipitation of solid matter is caused by filter paper (Toyo Filter Paper NO.
A drop of ink was dropped onto 2) with a dropper, and the presence or absence of precipitate was visually determined.

The antibacterial property is as follows. A certain amount of the bacteria of the following groups I and II is put in the ink, and a certain amount is applied to each medium, and the antibacterial agent at 0, 1, 2, 3, 7, 14 days is treated. The effect was judged by the change in the number of bacteria over time (killing rate of the bacteria). Culture Bacteria Medium Group I Escherichia coli ATCC 8739 Staphylococcus aureus ATCC 6538 SCDA Pseudomomas aeruginosa ATCC 9027 Group II Candida albicans 10231 GPLP The above group I and group II bacteria (commonly known as USP strains) are attached to the microbial test of the US Pharmaceutical Affairs Law. It is a regulated bacterium. Testing with this bacterium can confirm the lowest levels of antibacterial properties in cosmetics and foods.

[0024]

[Table 1]

[0025]

[Table 2]

As is clear from the results of Table 2, Example 1
When Comparative Examples 1 to 3 are compared with each other, Example 1 in which the three components of propylene glycol, paraoxybenzoic acid ester and phenoxyethanol are mixed is stable with time (pH value, color change, solid deposition) and It was found that the antibacterial property is excellent. On the other hand, in Comparative Example 1 in which phenoxyethanol was not mixed, a change in color (hue) accompanying a large change in pH (7.7 → 6.6) and precipitation of solid components such as dyes were confirmed, It was also found that the antibacterial property was significantly reduced. Comparative Example 2 in which propylene glycol was not blended and Comparative Example 3 in which no paraoxybenzoic acid ester (ethyl, propyl, butyl) was blended could not be used as a product because the antibacterial property was remarkably reduced, and -10 ° C. It was found that there was a color change and precipitation of solid matter at the standing temperature of.

Comprehensively examining the results of Table 2 and the like, the aqueous ink composition of the present invention is composed of propylene glycol, paraoxybenzoic acid ester, and phenoxyethanol defined in the cosmetic product type permission standard). For the first time, the components synergize with each other to enhance the antibacterial activity against harmful bacteria, stabilize the solubility of antibacterial agents, and stabilize the solubility of individual materials such as the stabilization of color development by stabilizing the solubility of dyes. It has been found that the ink system itself can be stabilized with the passage of time, and as a result, it is possible to increase the density of the drawn lines and the dryness of the drawn lines.

[0028]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain an aqueous ink composition having a high stability over time and a high antibacterial effect against harmful bacteria, and the use of the ink composition ensuring the safety to the human body also improves the safety. We can provide high quality products.

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Claims (2)

(57) [Claims] 1. A water-based ink composition in which a dye and additives to be added as necessary are all food additives and compatible products thereof, which contain propylene glycol and paraoxybenzoic acid ester, and the permission standard for each cosmetic product type. A water-based ink composition comprising phenoxyethanol as defined in 1. 2. The content of propylene glycol is 10.
The water-based ink composition according to claim 1, wherein 0 to 30.0% by weight, the content of paraoxybenzoic acid ester is 0.01 to 1.0% by weight, and the content of phenoxyethanol is 1.0 to 10.0% by weight. object.