JPH09241569A - Water-base ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-base ink composition which has excellent drying resistance and good writing quality and is desirable for use in writing utensils, recorders, printers, etc., by mixing a colorant with water and mixture of at least two specified compounds. SOLUTION: This composition is prepared by mixing a colorant(e.g. Aizen Primula Red 4BH) with water and a mixture of at least two members selected from compounds represented by the formula (wherein n is an integer of 1 or greater) and having different values of n. Examples of the compounds represented by the formula include p-xylyene glycol (n=1), 4,4'-bis(hydroxymethyl) dibenzyl ether (n=2) and 4,4''-bis (hydroxymethyl) tribenzyl ether (n=3). It is desirable to use a mixture comprising a compound represented by formula I (wherein n=1) and a compound represented by formula I (wherein n>=2) and having a content of the latter compound of 20wt.% or below.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous ink composition having excellent drying resistance, which can be used for writing instruments, stamps, recorders, printers, printing and the like.

[0002]

2. Description of the Prior Art Writing instruments using water-based inks up to now have the ink dried when the cap is removed from the writing instrument body and the pen tip is exposed to the atmosphere for a long time, and the solid matter clogs the ink flow path. , It was sometimes impossible to write.

Therefore, in order to obtain a water-based ink having excellent drying resistance, an ink has been known in which a water-soluble organic solvent such as ethylene glycol or urea or the like is added to its composition as an evaporation inhibitor. .

However, if a water-soluble organic solvent such as ethylene glycol or urea is used in the composition in order to obtain a water-based ink having excellent drying resistance, a considerably large amount must be added to the ink. No satisfactory improvement in performance was observed. In such a case,
There are problems such as difficulty in flowing out due to increase in ink viscosity, faint drawing lines, and marked deterioration in the sticking property of drawing lines on the non-absorption surface after writing due to difficulty in drying the ink.

Further, when a water-soluble organic solvent such as ethylene glycol is used, the surface tension of the ink is lowered, the drawn line tends to bleed, and a clear drawn line cannot be obtained. Furthermore, when urea is added, decomposition of urea occurs when the ink is stored at high temperature, and there is a problem in its stability. Furthermore, when the above-mentioned additives are added to the ink composition in order to improve the drying resistance, it may show a behavior of deteriorating the ink performance. The present situation is that an aqueous ink composition having excellent dryness has not been obtained.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of conventional water-based inks, and it is an object of the present invention to solve the problems. The purpose is to provide a water-based ink.

[0007]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that when a water-based ink contains a specific compound, it has good drying resistance and is filled in a pen. The inventors have found that there are no defects such as bleeding of strokes and blurring when written with the above, and thus completed the present invention. That is, the water-based ink composition of the present invention contains a colorant, water, and a mixture of at least two kinds of compounds represented by the following general formula (I) having different n values. Is characterized by.

Embedded image Among the compounds represented by the general formula (I), it is preferable to include a mixture of compounds of n = 1 and n ≧ 2. Also,
The content of the compound of n ≧ 2 in the mixture of the compounds of n = 1 and n ≧ 2 is preferably 20% by weight or less.

The reason why the water-based ink composition of the present invention is excellent in drying resistance is speculated as follows. When a water-based ink composition containing a mixture of at least two kinds of compounds having different values of n among the compounds represented by the general formula (I) is applied to a writing instrument or the like, it is easy to use with a pen tip or the like. Crystals will be deposited. This crystal is
It is considered that it plays a role of a lid in the opening of the pen tip, and suppresses evaporation and drying of water from the ink in the pen tip. In addition, the precipitated crystal is very thin, it is easily destroyed during writing, and the amount of crushed powder is also very small, and the influence on the drawn line is so small that it cannot be visually discerned, and it affects the writing performance. It does not affect.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the contents of the present invention will be described in detail. The water-based ink composition of the present invention contains a colorant, water (purified water), and a mixture of at least two kinds of compounds having different values of n among the compounds represented by the general formula (I). It will be. A mixture of at least two kinds of compounds having different values of n among the compounds represented by the general formula (I), which is the gist of the present invention, is used as a desiccant, and is mixed in an aqueous ink composition. However, it does not cause deterioration of ink performance such as bleeding of drawn lines and blurring. Examples of the compound represented by the general formula (I) include paraxylene glycol [where n = 1, another name: terephthalyl alcohol], 4,4′-bis (hydroxymethyl) dibenzyl ether [n = 2 Case, 4,4 ″ -bis (hydroxymethyl) tribenzyl ether [when n = 3], and the like, and these are used in combination of two or more kinds. In the compound represented by the general formula (I), n ≧ 2 is also a para-xylene glycol multimer, and when n = 2, a para-xylene glycol dimer, and when n = 3, It is a trimer.

The amount of the mixture used is 0.
01% to 10.0% by weight, preferably 0.1% by weight
~ 5.0% by weight. If the amount used is less than 0.01% by weight, the desired good drying resistance will not be obtained, and if it exceeds 10.0% by weight, not only will it be difficult to dissolve, but the pen tip will dry faster. Is not preferable. In addition, among the compounds represented by the general formula (I), n
As a mixture of at least two kinds of compounds having different values of, it is preferable to use a mixture of compounds of n = 1 and n ≧ 2. Further, the content of the compound of n ≧ 2 in the mixture is 20% by weight or less (based on the total amount of the mixture),
It is preferably 3.0% by weight to 15.0% by weight. When the content is within this range, the drying resistance, which is the effect of the present invention, can be efficiently and maximally exhibited.

As the coloring material, any of the dyes and pigments conventionally used in water-based inks can be used without limitation. Examples of the dyes include direct dyes such as Eisenbrimura Red 4BH and Eisenbrimuraello GCLH (manufactured by Aisen Co., Ltd.), Aisenbonso RH, Aizen Opal Pink BH, Aizen Opal Black WH Extra Conc (or more, Eisen Co., Ltd., Orient Solvel Blue OBX, Orient Solvel Blue OBB (above, Orient Chemical Co., Ltd.)
Acid dyes such as), tartrazine, acid red,
Examples thereof include food dyes such as Phloxine (above, manufactured by Eisen Co., Ltd.). Examples of the pigment include inorganic pigments such as carbon black, titanium oxide and iron oxide, organic pigments such as phthalocyanine pigments and azo pigments, inorganic fluorescent pigments such as calcium sulfide, and other organic fluorescent pigments. These dyes and pigments may be used alone or in combination of two or more, and preferably 0.1% by weight to 40.0% by weight based on the total amount of the ink.

When the above pigment is used as a coloring material, it is desirable to use a dispersant at the same time. As the dispersant, for example, used in general water-based ink,
John Krill J-62, John Krill J-450 (manufactured by Johnson Co.), Jolimar AT-210, Jolimar S
Water-soluble resins such as EK-101 (manufactured by Nippon Pure Chemical Industries, Ltd.), anion activators, nonion activators and the like can be used without limitation.

In addition to the above main components, sodium benzoate (manufactured by Wako Pure Chemical Industries, Ltd.), Bioden-18, Amorden-HS, Amorden BT-50, Amorden FS
A small amount of antibacterial agent such as -14D (all manufactured by Daiwa Chemical Industry Co., Ltd.), Proxel BDN, Proxel GXL, Proxel TN (all manufactured by Zeneca Corporation) can be added. Further, as the pH adjuster, for example, aminomethyl propanol and triethanolamine (above, manufactured by Wako Pure Chemical Industries, Ltd.) can be added. Furthermore, since the tip of the ballpoint pen is used, anticorrosive agents, lubricants, etc. can be used without limitation.

The aqueous ink composition of the present invention can be manufactured by the following method. In the case of dye ink, the above components are mixed by stirring to dissolve them. In the case of a pigment ink or an ink in which a pigment and a dye are used in combination, the above components are mixed and pulverized by a known disperser such as a ball mill, a roll mill, a sand mill, a flow mill, a dyno mill or an attritor. The desired aqueous ink composition can be easily obtained by removing coarse particles and dust from the intermediate product obtained by stirring and mixing or pulverizing the mixture, if necessary, by a method such as filtration and centrifugal sedimentation.

[0015]

EXAMPLES Next, the contents of the present invention will be described in more detail with reference to Examples.

Example 1 Water 71.70 parts by weight Carbon black MA-100 (manufactured by Mitsubishi Chemical Co., Ltd.) 15.00 Jonkuryl 62 (dispersant, manufactured by Johnson Co.) 10.00 Aminomethylpropanol 0.10 Bioden-18 (antibacterial agent, manufactured by Daiwa Chemical Industry Co., Ltd.) 0.20 Para-xylene glycol 2.85 4,4'-bis (hydroxymethyl) dibenzyl ether 0.15 Mix and grind the above components After that, a black ink was prepared by filtering.

Example 2 Water 67.51 parts by weight Emacol.Blue.FB (pigment, manufactured by Sanyo Dyestuffs Co., Ltd.) 18.00 Johncryl J450 (dispersant, manufactured by Johnson Co.) 11.13 Triethanolamine 0.13 Proxel BDN (antibacterial agent, manufactured by Zeneca Corporation) 0.23 para-xylene glycol 2.82 4,4'-bis (hydroxymethyl) dibenzyl ether 0.18 After mixing and pulverizing the above components, filter To prepare a blue ink.

Example 3 Water 56.67 parts by weight Fuji.SP.Red.5111 (pigment, manufactured by Fuji Dye Co., Ltd.) 18.00 Jolima-AT210 (dispersant, manufactured by Nippon Pure Chemical Co., Ltd.) 12.00 Propylene glycol 10.00 Aminomethyl propanol 0.13 Amorden-HS (antibacterial agent, manufactured by Daiwa Chemical Industry Co., Ltd.) 0.20 Paraxylene glycol 2.85 4,4 ″ -bis (hydroxy) Methyl) tribenzyl ether 0.15 The above components were mixed and ground, and then filtered to prepare a red ink.

Example 4 Water 61.77 parts by weight Eisenburi Mura Red 4BH (dye) 3.77 Eisenburu Muraero-GCLH (dye) 0.23 Propylene Glycol 30.00 Triethanolamine 0.01 Benzoic Acid Sodium 1.22 para-xylene glycol 2.82 4,4 ″ -bis (hydroxymethyl) tribenzyl ether 0.18 After mixing and stirring the above components, a red ink was prepared by filtering.

Comparative Examples 1 to 4 Examples 1 to 4 except that water was used instead of the compound (mixture of n = 1, 2, 3) represented by the general formula (I) in Examples 1 to 4 above. Each ink was prepared in the same manner as in.

Test Example Each of the ink compositions obtained in the above Examples 1 to 4 and Comparative Examples 1 to 4 was prepared with a commercially available aqueous pen for fine writing (Mitsubishi PIN-103:
It was filled in Mitsubishi Pencil Co., Ltd., the cap was removed, the sample was left in the atmosphere, handwritten every fixed time, and the time until it became faint and unable to be drawn was measured. As a result, the writable leaving time was 5 minutes or less in any of Comparative Examples 1 to 4, while the writable leaving time was extended to 120 minutes or more in any of Examples 1 to 4. . Further, the water-based ink compositions containing the mixture of the compounds represented by the general formula (I) of Examples 1 to 4 [mixture of n = 1, 2, 3] do not show deterioration or change in ink performance. I understood.

[0022]

EFFECTS OF THE INVENTION According to the present invention, there is provided a water-based ink composition which is excellent in drying resistance at the pen tip of a writing instrument and has good writing quality.

Claims (3)

[Claims] 1. A water-based ink composition comprising a colorant, water, and a mixture of at least two types of compounds represented by the following general formula (I) having different n values. Embedded image 2. A mixture of compounds represented by the general formula (I), wherein n = 1 and n ≧ 2.
The water-based ink composition described. 3. The aqueous ink composition according to claim 2, wherein the content of the compound of n ≧ 2 in the mixture of the compounds of n = 1 and n ≧ 2 is 20% by weight or less.