JPS6123827B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides an aqueous ink composition suitable for writing instruments, stamps, printing, and recorders, and more specifically, it suppresses evaporation, has excellent drying resistance even when exposed to the atmosphere for a long time, and has a high density. The present invention relates to an aqueous ink composition having the following characteristics. Traditionally, for example, writing instruments, specifically writing instruments with pen nibs made of fiber, felt, or monofilament,
Or, for capillary type writing instruments such as fountain pens, even if the pen tip is exposed to the atmosphere for a long time during storage or when the cap is removed from the writing instrument body, the ink always flows out smoothly without clogging the ink flow path of the pen tip. However, there was a demand for a water-based ink that would allow for extremely smooth writing. In order to meet this demand, water-soluble organic solvents such as glycol solvents, glycol ether solvents, and glycol ether ester solvents, or hygroscopic inorganic compounds such as lithium chloride and calcium chloride, are included in the aqueous solution of water-soluble dyes to make them dry-resistant. Water-based inks with improved dryness resistance have been known, but none have satisfactorily achieved dryness resistance. The reason for this is that glycol solvents generally have a high viscosity and a high boiling point, which increases the viscosity of the ink.
When used in writing instruments that require low viscosity, the outflow of ink is inhibited, causing ink to run out.
Furthermore, it has drawbacks such as the handwriting is difficult to dry and the abrasion resistance after writing is poor, and there is a limit to the amount used, and it is not possible to add it in an amount sufficient to satisfy the drying resistance. Glycol ether solvents and glycol ether ester solvents generally have low surface tension, so handwriting tends to smear, and the ink may penetrate to the back side of the paper or smudge on the surface, making it impossible to obtain clear handwriting. It has disadvantages such as low ability to dissolve dyes, insufficient color development, increased ink viscosity, and strong odor.
Similarly to the above, it is not possible to add enough amount to satisfy the drying resistance. In addition, lithium chloride and calcium chloride react with dyes to form salts and reduce the solubility of dyes, making it difficult to prepare inks with high concentrations and making it impossible to add them in amounts sufficient to satisfy drying resistance. Furthermore, inks other than those for writing instruments, such as inks for stamps, have not yet been sufficiently developed. Therefore, the present inventors have conducted various studies to solve the conventional problems mentioned above, and have found that when an alkylsulfonamide derivative is blended into an aqueous solution of a water-soluble dye, the drying resistance is good and the viscosity suddenly increases. The present invention was completed based on the discovery that an aqueous ink composition with excellent dye solubility can be obtained without an increase in dye solubility. That is, the gist of the present invention is a water-based ink composition in which an alkylsulfonamide derivative represented by the following general formula (1) is blended into an aqueous solution of a water-soluble dye. [In the formula, m is an integer of 1 to 20, R ₂ is hydrogen or
An alkyl group represented by Cm′H ₂ m′+1 (m′ is an integer from 1 to 5) or

It represents an oxyalkyl group represented by the formula: (n is an integer of 1 to 5, R ₁ is hydrogen or a methyl group). ] As the alkylsulfonamide derivatives, methanesulfonamide, ethanesulfonamide, propanesulfonamide, isopropanesulfonamide, n-tetradecanesulfonamide, methane-
N-methylsulfonamide, ethane-N-methylsulfonamide, propane N-methylsulfonamide, isopropane N-methylsulfonamide,
n-tetradecane N-methylsulfonamide, methane N-ethylsulfonamide, ethane N-ethylsulfonamide, propane N-ethylsulfonamide, isopropane N-ethylsulfonamide, n-tetradecane N-ethylsulfonamide, etc. and ethylene oxide Alternatively, addition products with propylene oxide may be mentioned. Next, each component of the aqueous ink composition of the present invention will be explained in more detail. Most of the water-soluble acid dyes, direct dyes, and basic dyes can be used as water-soluble dyes.
(CI45380), Water Black #21 (C.
Mixed dyes of I.15985, 42090, 42745), nigrosine
NBconc (CI50420), water blue #9
(CI42090), Water Pink # (CI45410),
Kayaktarazin (CI19140) and other direct dyes include Water Black #100 (C.
I.35255), Direct Deep Black XA (manufactured by Sumitomo Chemical), Direct Deep Black EX
(CI35225), Direct First Black
conc (CI27720), etc. Basic dyes include Victoria Blue F4B (CI42563), Victoria Blue FB (CI44045), and Methyl Violet.
FN (CI42535), Rhodamine 6GCP (CI45160)
These dyes can be used alone or in combination with other water-soluble dyes. The amount of the water-soluble dye to be used may be varied depending on the purpose; for example, when used as an ink for writing instruments, suitable results can be obtained when it is used in an amount of 0.5 to 30% by weight of the ink composition. The amount of the alkylsulfonamide derivative represented by general formula (1) to be used varies depending on the purpose, but for example, when used as an ink for writing instruments,
Suitable results are obtained when it is used in an amount of 5 to 70% by weight of the ink composition. The solubility of the dye is increased, the hygroscopicity is good, the dye in the ink does not coagulate at room temperature, and the ink at the tip of the pen does not evaporate even if the cap is removed and left in the atmosphere for a long time. An ink composition with excellent drying properties can be obtained. Acidic can directly increase the solubility of all basic dyes,
In particular, it is possible to use direct dyes, which have conventionally been poorly used due to poor solubility, and therefore, by using direct dyes, an inca composition with good water resistance and drying resistance can be obtained. As mentioned above, the present invention greatly improves drying resistance by adding and blending the compound represented by general formula (1) to an aqueous solution of a water-soluble dye.
If necessary, solvents such as glycol, glycol ether, glycol ether ester, dimethyl oxide, 2-pyrrolidone, and N-methyl-2-pyrrolidone, or preservatives may be appropriately selected and used. Examples of the present invention will be described below regarding ink for writing instruments. In the examples, parts simply refer to parts by weight. Example 1 Eiseneosin GH (CI45380, manufactured by Hodogaya Chemical Industry Co., Ltd.) 4.0 parts Sodium pentachlorophenol (preservative)
1.0〃 Ethylene glycol 20.0〃 Methanesulfone diethanolamide 25.0〃 Water 50.0〃 Ethylene glycol and water among the above components were mixed first, and then the remaining components were mixed into the mixed solution and heated to 40 to 50°C for about 1 hour. Stir while heating to make ink. This ink has good color strength and
The adhesive properties on writing paper are also good, and when used on writing paper, it does not smudge or bleed. In addition, the drying resistance of this ink can be tested by removing the cap from a writing instrument made of fiber, felt, monofilament, porous, or using a capillary tip and leaving it for 10 days at a temperature of 20°C and humidity of 65°C. Even when I left it in the water, the pen tip did not dry out and I was able to write on it. Note that an ink obtained by removing methanesulfone diethanolamide from this formulation and adding that amount of water dried under the same conditions in about one day. Example 2 Water black #21 (CI15985, 42090,
42745 mixed dye, manufactured by Orient Chemical Industry Co., Ltd.)
6.5 parts Nigrosine NBconc (CI50420, manufactured by Sumitomo Chemical Co., Ltd.) 1.0〃 Formalin (preservative) 1.0〃 Ethylene glycol 20.0〃 Methanesulfone diisopropanolamide 20.0〃 Water 51.5〃 The above ink has good writing characteristics, and Example 1
Even if I left the pen for 10 days with the cap removed under the same conditions as above, the pen tip did not dry out and I was still able to write. Note that an ink obtained by removing methanesulfone diisopropanolamide from this formulation and adding that amount of water dried in about one day under the same conditions. Example 3 Water black #100 (CI35255, manufactured by Orient Chemical Industry Co., Ltd.) 6.5 parts Sodium pentachlorophenol (preservative)
1.0〃 Ethylene glycol 20.0〃 Reaction product of tetradecane sulfonamide and ethylene oxide (10 mol) 15.0〃 Water 57.5〃 The above ink has good writing properties, and Example 1
Even if I left the pen for 10 days with the cap removed under the same conditions as above, the pen tip did not dry out and I was still able to write. An ink obtained by removing the reaction product of tetradecane sulfonamide and ethylene oxide (10 moles) from this formulation and adding that amount of water dried under the same conditions in about one day. Although the present invention has been mainly described above with respect to a water-based ink composition for writing instruments, it can also be applied to water-based ink compositions for stamps, printing, recorders, and the like.

Claims (1)

[Scope of Claims] 1. An aqueous ink composition characterized by containing an alkylsulfonamide derivative represented by the following general formula (1). [In the formula, m is an integer of 1 to 20, R ₂ is hydrogen or
Cm′H ₂ m′+1 (m′ is an integer of 1 to 5) or an oxyalkyl group represented by [Formula] (n is an integer of 1 to 5, R ₁ is hydrogen or methyl group) represent ]