JP3035147B2 - 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 a picture or a writing ink for general writing implements used by infants and lower grades.

[0002]

2. Description of the Related Art Conventionally, aqueous ink compositions used for marking pens, ball-point pens and the like are well known. For example, a water-soluble dye and water as essential components, and a solvent, an It can be easily prepared by adding additives such as an activator, a pH adjuster and a preservative. In recent years, attention has been paid to the problem of ecology, and safety is required both for ink compositions for writing instruments and the like, and for coloring materials and solvents. However, in general, the danger to the human body of the water-based ink composition is less problematic than the oil-based ink composition containing a highly toxic volatile component. For this reason, the material used for the aqueous ink composition is selected mainly from the viewpoint of the performance and the price as the ink.

[0003] By the way, in the aqueous ink composition, harmful bacteria may be generated and propagated in the writing instrument, if the conditions are satisfied, and may greatly affect the performance of the product itself, for example, may cause poor writing and an unpleasant odor. In addition, adverse effects on the human body,
For example, there is a risk that mold spores scattered from a writing instrument may be inhaled or the infant may accidentally lick it.

Therefore, in the conventional water-based ink composition, an antiseptic effect is imparted to harmful bacteria such as mold and bacteria by adding an antiseptic. This preservative suppresses or kills the generation of harmful bacteria, but those having a high preservative effect are often harmful not only to harmful bacteria but also to the human body. Under these circumstances, as a safe water-based ink composition, dyes as essential components and additives such as solvents, surfactants, and preservatives that are added as necessary are all derived from food additives and compatible products. Aqueous ink compositions are already known (JP-A-4-298577, JP-A-4-3180).
No. 81). In these publications, as a pH adjuster,
For example, in the official standard of food additives (6th edition), citric acid, lactic acid, malic acid, succinic acid, gluconic acid, etc. specified as sour agents, phosphoric acid specified as brewing materials,
It has been suggested that sodium carbonate, sodium hydrogen carbonate, potassium carbonate, dipotassium phosphate, etc., which are specified as alkali materials for food production, such as ammonium sulfate, can be used.

However, in the aqueous ink composition containing the pH adjuster described in the above-mentioned officially defined food additive (sixth edition), the pH is liable to change due to aging and the like.
There is a problem that the hue of the ink is changed and the preservative effectiveness is also reduced due to the decrease in the dissolution stability of the preservative. Accordingly, it is desirable to achieve further improvements in aqueous ink compositions.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide an aqueous ink composition which is excellent in stability over time and antiseptic effect against harmful bacteria. And

[0007]

Means for Solving the Problems In order to solve the above-mentioned conventional problems, the inventors of the present invention have changed the materials of the aqueous ink composition to the official standard for food additives (6th edition) and the standard for cosmetic raw materials (6th edition). 2nd edition), and as a result of intensive research, as compared with the above-mentioned conventional aqueous ink composition, the performance was satisfactory and the stability over time and the antiseptic effect against harmful bacteria were excellent. The aqueous ink composition was successfully obtained, and the present invention was completed.

That is, the present invention relates to an aqueous ink composition containing at least a dye, water and a pH adjuster,
It is characterized in that all components except for the H adjuster are composed of food additives and their compatible products, and the pH adjuster is composed of triethanolamine specified in the standard of cosmetic raw materials. The blending amount of the triethanolamine is preferably 0.01 to 1.0% by weight based on the total amount of the ink composition. The aqueous ink composition preferably contains at least one of a solvent, a surfactant, and a preservative.

[0009]

According to the present invention, all components of the aqueous ink composition except for the pH adjuster are composed of food additives and their compatible products.
The conditioning agent is composed of triethanolamine specified in the standard of cosmetic raw materials. This triethanolamine is the first water-based ink composition composed of food additives and its compatible products to have stability over time and antiseptic against harmful bacteria. It is based on the new fact that potency can be increased, and the object of the present invention will not be achieved if this triethanolamine is not contained.
(This point will be described in detail in Examples and the like which will be described later). The stability over time defined in the present invention is determined based on a pH value, a change in the color of an ink, and the precipitation of solids, and the antiseptic effect refers to the loss of an antiseptic in an ink composition. It means to prevent activity.

Hereinafter, the contents of the present invention will be described in detail. The triethanolamine [N (CH ₂ CH ₂ OH) ₃ used in the present invention as a pH adjuster is specified in the standard for cosmetic raw materials (second edition), and its safety has already been confirmed. The triethanolamine is used for the purpose of enhancing the stability of the aqueous ink composition over time and the preservative effect against harmful bacteria. Further, the triethanolamine used in the present invention is limited to those specified in the standard for cosmetic raw materials (second edition). The first reason is that purity is different between industrial triethanolamine and triethanolamine specified in the standard of cosmetic raw materials (second edition). That is, it depends on the difference in impurities. Triethanolamine specified in the Cosmetic Ingredients Standard (Second Edition) does not include nitrosamines such as dimethylnitrosamine and diethylnitrosamine as impurities contained therein. Nitrosamines generate toxic compounds, especially when a chemical having a hydroxyl group replaced by a halogen element acts, and in addition, this compound is a carcinogenic substance,
It is a substance with a high risk to the human body. Therefore, from the viewpoint of human safety, the use of triethanolamine specified in the Cosmetic Ingredients Standard (Second Edition), which does not contain impurities of nitrosamines, is limited. Secondly, when all the components of the aqueous ink composition, especially the pH adjuster are composed of food additives and their compatible products, effective solvents used for general aqueous inks, for example, ethylene glycol, diethylene glycol, Since the use of the activator is restricted, the ink composition tends to change under a small condition. Therefore, due to the influence of heavy metals contained as contained impurities, it is easy to cause a change in hue over time of the written line and deactivation of the preservative effect of the preservative. Therefore, without selecting a pH adjuster from food additives and their compatible products,
Triethanolamine specified in the above-mentioned standard for cosmetic raw materials (second edition) was selected. These points will be described in detail in Examples, Comparative Examples, and Safety Test Examples which will be described later.

The amount of triethanolamine used in the present invention is 0.01 to 0.01% based on the total amount of the aqueous ink composition.
It is 1.0% by weight, preferably 0.01 to 0.1% by weight. If the amount is less than 0.01% by weight, a change in hue tends to occur. If the amount is more than 1.0% by weight, the pH increases and the preservative effect decreases, which is not preferable. By blending triethanolamine in the aqueous ink composition of the present invention, stabilization of color development by stabilization of dye solubility and stabilization of solubility of individual materials such as stabilization of preservative solubility are obtained. Stabilization of the ink system itself over time is achieved. Further, dry-up resistance and the like when the cap is off for a long time can be obtained.

In the water-based ink composition of the present invention, legal dyes specified as coloring agents for food additives are used as dyes. Specific examples thereof include, for example, Food Red No. 2, No. 3, No. 102, No. 104, No. 105,
Food colors such as No. 06, Food Yellow No. 4, No. 5, Food Blue No. 1, No. 2, etc., Turmeric Dye (yellow), Pubica Dye (orange), Cochineal Dye (red), Gardenia Blue Dye (blue) ), Β-carotene (yellow) and the like, and most colors can be prepared by appropriately mixing these edible pigments and / or legal pigments of the natural pigments.

[0013] The aqueous ink composition of the present invention may contain a solvent specified in the official specification of food additives (6th edition). The solvent is used to enhance the antiseptic effect and the stability over time when the performance of the ink is insufficient simply by dissolving the legal dye used as the dye in water. As the solvent, for example, glycerin, D specified in the Food Additives Compendium (Sixth Edition)
-Sorbitol liquid, propylene glycol and the like,
These may be used alone or as a mixture of two or more.

[0014] Further, a surfactant specified as an emulsifier in the Japanese Standards for Food Additives (6th edition) may be used for improving the wettability. Examples of the surfactant include glycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, and the like. These may be used alone or in combination of two or more.

[0015] Further, a preservative specified as a preservative in the official Japanese Standards for Food Additives (6th edition) may be used to prevent the generation of harmful bacteria of the ink such as bacteria and fungi. Examples of the preservative include sodium dehydroacetate, sorbic acid, potassium sorbate, benzoic acid, sodium benzoate, paraoxybenzoic acid esters (eg, ethyl, propyl, butyl, isobutyl, isopropyl, etc.), propionic acid, propionic acid Sodium may be used, and these may be used alone or in combination.

The aqueous ink composition of the present invention uses triethanolamine as a pH adjuster specified in the standard of cosmetic raw materials, and uses all the ink components except the pH adjuster as the above various food additives and their compatible products. By using the composition, water-based ink compositions for various uses such as for painting used by infants and lower grades, or for general writing instruments such as water-based marking pens and ball-point pens can be prepared.

[0017]

Next, the present invention will be described more specifically and in detail with reference to examples, comparative examples and safety test examples, but the present invention is not limited to these examples. Note that “%” in Examples and Comparative Examples is% by weight. (Examples 1 to 5, Comparative Examples 1 to 10)

Each of the components of Examples 1 to 5 and Comparative Examples 1 to 10 was mixed at the compounding ratios shown in Tables 1, 3, 5, 7, and 9 below, and stirred for 5 hours. Were prepared respectively. Examples 1 to 5 are cases in which triethanolamine specified in the standard of cosmetic raw materials is contained as a pH adjuster, and Comparative Examples 1, 3, 5, 7, and 9 are cases in which no pH adjuster is contained. Comparative Examples 2, 4,
6, 8, and 10 use the pH adjuster as a food additive official standard (No. 6).
Comparative Example 2 was potassium carbonate (0.1N), Comparative Example 4 was sodium lactate, Comparative Example 6 was potassium carbonate (0.1N), Comparative Example 8
Is L-ascorbic acid, and Comparative Example 10 uses disodium hydrogen phosphate. Then, each of Examples 1 to 5
And after storing each of the aqueous ink compositions prepared in Comparative Examples 1 to 10 in a constant temperature bath at 50 ° C. and −10 ° C. for 3 months, the aging stability (pH value, color change) of each ink composition , Solid deposits) and the preservative efficacy are shown in Tables 2, 4, 6, 8, and 10 below.

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

Precipitation of the solid matter was performed using filter paper (Toyo Roshi Kaisha NO.
In 2), one drop of ink was dropped with a dropper, and the presence or absence of a precipitate was visually determined.

The antiseptic effect was measured by adding a fixed amount of each of the following groups I and II to the ink, applying a fixed amount to each medium, and examining the antibacterial agent on days 0, 1, 2, 3, 7, and 14. The effect was determined by the change in the number of bacteria over time (killing rate of bacteria). Culture medium Medium Group I Escherichia coli ATCC 8739 Staphylococcus aureus ATCC 6538 SCDA Pseudomomas aeruginosa ATCC 9027 Group II Candida albicans 10231 GPLP The above-mentioned bacteria of Groups I and II (commonly known as USP strain) have been prepared for microbial testing by the United States Pharmaceutical Affairs Law. It is a regulated bacterium. Testing with this fungus can confirm the lowest level of preservative efficacy of cosmetics and foods.

The evaluation criteria in Tables 2, 4, 6, 8, and 10 are as follows. A: No change from the initial value. Δ: Smaller than initial value (problem as a product). ×: Greater than initial value (added as product).

(Example of safety test) Table 11 below shows the aqueous ink composition of the present invention, and the aqueous ink obtained by changing triethanolamine based on cosmetic raw materials in the aqueous ink composition of the present invention to industrial ethanol. The results of testing the safety of the composition, the conventionally used water-based ink composition, and the raw materials (triethanolamine, industrial triethanolamine, nitrosamines based on cosmetic raw materials) are shown. Safety is the value of LD ₅₀ by additive rule. The larger the value of this LD _50, the higher the safety. The LD ₅₀ refers to a lethal dose (mg / kg) required to kill a majority of the specimens when a certain amount is orally administered to mice and rabbits for a certain period of time. In addition, the range (range) of the LD ₅₀ of each aqueous ink composition described in the first part of Table 11 indicates the maximum value and the minimum value when various aqueous ink components are combined.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

[0027]

[Table 4]

[0028]

[Table 5]

[0029]

[Table 6]

[0030]

[Table 7]

[0031]

[Table 8]

[0032]

[Table 9]

[0033]

[Table 10]

[0034]

[Table 11]

As is clear from the results of Tables 2, 4, 6, 8, and 10, when Examples 1 to 5 and Comparative Examples 1 to 10 are compared, triethanolamine specified in the standard of cosmetic raw materials is The contained Examples 1 to 5 show the stability over time (p
H value, color change, solid deposition) and antiseptic effect were both excellent. On the other hand, when triethanolamine is not contained (Comparative Examples 1, 3, 5, 7,
9) Alternatively, the pH adjuster may be added to the official
(Comparative Example 2,
In Comparative Examples 1 to 10 of 4, 6, 8, and 10), it was confirmed that the color (hue) was changed due to a large change in pH, solid content such as dye was precipitated, and the antiseptic effect was significantly reduced. It was found that all of the aging stability (pH value, color change, solid deposition) and antiseptic effect could not be satisfied.

Further, as is apparent from the results shown in Table 11, the aqueous ink composition of the present invention is 5 times less than the conventionally used aqueous marking pen ink composition.
It was found that the safety was about 8 times higher. Further, nitrosamines (dimethylnitrosamine, diethylnitrosamine) have been confirmed to be highly toxic, and industrial triethanolamine which may contain these impurities, and an aqueous ink composition using the industrial triethanolamine. Was found to be less safe than the aqueous ink composition of the present invention. Summarizing these results, the aqueous ink composition of the present invention contains triethanolamine specified in the Cosmetic Ingredients Standard (Second Edition), and for the first time, enhances the antiseptic effect against harmful bacteria, and
The stability of the ink system itself over time can be obtained by stabilizing the solubility of individual materials, such as stabilization of color development by stabilizing the solubility of dyes. Can also be obtained,
Moreover, it was found that the safety was extremely high.

[0037]

According to the present invention, it is possible to obtain an aqueous ink composition having high aging stability and an antiseptic effect against harmful bacteria, and the use of the ink composition which has ensured the safety for the human body enables the safety. Aqueous ink composition having a high water content.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C09D 11/00-11/20

Claims (3)

(57) [Claims] 1. An aqueous ink composition containing at least a dye, water and a pH adjuster, wherein all components except the pH adjuster are composed of food additives and their compatible products, and the pH adjuster is specified in the standard of cosmetic raw materials. An aqueous ink composition comprising triethanolamine. 2. The aqueous ink composition according to claim 1, wherein the amount of the triethanolamine is 0.01 to 1.0% by weight based on the total amount of the ink composition. 3. The aqueous ink composition according to claim 1, further comprising at least one of a solvent, a surfactant, and a preservative.