JPH0967534A - Water-base ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-base ink improved in drying resistance without deteriorating or changing the ink by mixing a colorant with water and 1,4- cyclohexanediol. SOLUTION: This water-base ink composition is prepared by mixing 0.1-40wt.% colorant comprising a dye or a pigment with 40-95wt.% water, 0.01-50wt.% 1,4-cyclohexanediol and optional additives such as an antibacterial, a pH controlling agent, an organic solvent, an anticorrosive and a lubricant.

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 Related Art A writing instrument using water-based ink has a problem that when the cap is removed from the writing instrument main body and the pen tip is exposed to the atmosphere for a long period of time, the ink dries to form a solid substance and clog the ink flow path. It may be possible. An ink in which a water-soluble organic solvent such as ethylene glycol or urea is added as an evaporation inhibitor in order to obtain a water-based ink having excellent drying resistance is known. When a water-soluble organic solvent such as ethylene glycol or urea is used, satisfactory performance improvement cannot be observed unless it is added to the ink in a considerably large amount. In such a case, the increase in the viscosity of the ink makes it difficult for the ink to flow out, the drawn line is faint, and the ink is difficult to dry. For this reason, the problem is that the phenomenon in which the line-fixing property on the non-absorbing surface after writing is significantly reduced becomes remarkable. Further, when a water-soluble organic solvent such as ethylene glycol is used, the surface tension of the ink is lowered, and the drawn line tends to bleed, so that a clear drawn line cannot be obtained. Further, when urea is added and the ink is stored at a high temperature, urea is decomposed and there is a problem in its stability. Thus, in order to improve the drying resistance, when the above-mentioned additives are added to the ink composition, it often exhibits a behavior that deteriorates the ink performance, and it is desired to solve these problems. .

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a water-based ink composition which suppresses deterioration or change in ink performance and is excellent in drying resistance. It is to be.

[0004]

Means for Solving the Problems As a result of repeated studies to solve the above problems, the present inventors have found that when water-based ink is blended with 1,4-cyclohexanediol, the drying resistance is good. The present invention has been completed by finding that there are no defects such as bleeding of drawing lines and blurring when the pen body is filled and written. That is,

The aqueous ink composition of the present invention is characterized in that the aqueous ink containing a colorant and water contains 1,4-cyclohexanediol.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION 1,4-Cyclohexanediol used in the ink composition of the present invention has the following formula:

Embedded image Indicated by The content of 1,4-cyclohexanediol in the ink composition is 0.01% to 50%, preferably 0.5% to 30%, more preferably 0.5% to 10%.
It is. When the content is within this range, an ink composition having excellent dry resistance can be provided. If it is less than 0.01%, an ink having a dry resistance cannot be obtained, and if it exceeds 50%, there is a problem in the storage stability of the ink composition.

As the colorant used in the ink composition of the present invention, any dye or pigment conventionally used in water-based inks can be used without limitation. As the dyes, direct dyes such as Aizen Brimla Red 4BH and Aizen Blumuraello GCLH (above, made by Aizen Co., Ltd.), Aizen Bonso RH, Aizen Opal Pink BH, Aizen Opal Black WH Extraconc (above, Co., Ltd.) Eisen), Orient Solve Blue OBX, Orient Solve Blue OBB (above, Orient Chemical Co., Ltd.)
Acid dyes such as), tartrazine, acid red,
Examples include food dyes such as Phloxine (above, manufactured by Aizen Co., Ltd.). These colorants can be used alone or in combination with others, and are 0.1 to 0.1% of the total amount of ink.
40% by weight is desirable. Examples of the pigment include inorganic pigments such as carbon black, titanium oxide and iron oxide, inorganic pigments and organic pigments such as phthalocyanine pigments and azo pigments, inorganic fluorescent pigments such as calcium sulfide, and other organic fluorescent pigments.

When a pigment is used as a colorant, it is desirable to use a dispersant at the same time. Jonkryl J-62 and Jonkryl J, which are commonly used as dispersants
-450 (manufactured by Johnson), Jolimer AT-21
0, Jolimmer SEK-101 (Nippon Pure Chemical Industries, Ltd.)
Water-soluble resins such as those manufactured by K.K.), anion activators, nonionic activators, etc. can be used without limitation.

The water content of the ink composition of the present invention is not particularly limited, but is usually 40 to 95% by weight in the ink composition.

The ink composition of the present invention contains the above 1,4
The following may be used in addition to the cyclohexanediol, the colorant and the main components of water. Sodium benzoate (manufactured by Wako Pure Chemical Industries, Ltd.), Bioden-18,
Amorden-HS, Amorden-HS, Amorden BT
A small amount of antibacterial agent such as -50, Amorden FS-14D (above, manufactured by Daiwa Chemical Industry Co., Ltd.), Proxel BDN, Proxel GXL, Proxel TN (above, manufactured by Zeneca Corporation) can be added. Also, as a pH adjuster, aminomethyl propanol, triethanolamine (above,
Wako Pure Chemical Industries, Ltd.), propylene glycol or the like can be added as an organic solvent. Furthermore, since the tip of the ballpoint pen is used, anticorrosive agents, lubricants, etc. can be used without limitation.

The method for producing the aqueous ink composition of the present invention is as follows. 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 well-known dispersers, for example, a ball mill, a roll mill, a sand mill, a flow mill,
Mix and pulverize with a Dyno mill, attritor, etc. The intermediate obtained by stirring and mixing or mixing and pulverizing these,
It can be easily obtained by removing coarse particles and dust by a method such as filtration or centrifugal sedimentation, if necessary.

The reason why the water-based ink composition of the present invention is excellent in drying resistance is presumed as follows. 1,4-
Cyclohexanediol has two hydroxyl groups in the molecule and has a strong hydrogen bonding force with a water molecule. It is believed that this force of hydrogen bonding suppresses evaporation and drying of water from the water-based ink at the pen tip.

[0013]

The present invention will be described below in detail with reference to examples. (Example 1) Pigment: "Carbon black MA-100" [manufactured by Mitsubishi Chemical Corporation] 15.0 parts by weight Dispersant: "John Kryl 62" [manufactured by Johnson Co.] 10.0 parts by weight pH adjuster : Aminomethyl propanol 0.1 parts by weight Antibacterial agent: "Bioden-18" (manufactured by Daiwa Chemical Industry Co., Ltd.) 0.2 parts by weight 1,4-cyclohexanediol 10.0 parts by weight water 64.7 parts by weight Above A black ink was obtained by mixing and pulverizing each component and then filtering. (Comparative Example 1) A black ink was obtained in the same manner as in Example 1 except that water was used instead of 1,4-cyclohexanediol.

(Example 2) Pigment: "Emacol.Blue.FB" [manufactured by Sanyo Dye Co., Ltd.] 18.00 parts by weight Dispersant: "John Cryl J450" [manufactured by Johnson Co.] 11.13 parts by weight pH adjuster: triethanolamine 0.13 parts by weight Antibacterial agent: "Proxel BDN" [manufactured by Zeneca Corporation] 0.23 parts by weight 1,4-cyclohexanediol 10.00 parts by weight water 60.51 parts by weight A blue ink was obtained by mixing and pulverizing each component and then filtering. (Comparative Example 2) A blue ink was obtained in the same manner as in Example 2 except that water was used instead of 1,4-cyclohexanediol.

(Example 3) Primitive: "Euji.SP.Red.5111" [manufactured by Fuji Dye Co., Ltd.] 18.00 parts by weight Dispersing agent: "Jolimer AT210" [manufactured by Nippon Pure Chemical Industries, Ltd. ] 12.00 parts by weight pH adjuster: aminomethyl propanol 0.13 parts by weight Antibacterial agent: "Amorden-HS" [manufactured by Daiwa Chemical Industry Co., Ltd.] 0.20 parts by weight 1,4-cyclohexanediol 10.00 Parts by weight Water 59.67 parts by weight After mixing and pulverizing the above components, a red ink was obtained by filtering. (Comparative Example 3) A red ink was obtained in the same manner as in Example 3 except that water was used instead of 1,4-cyclohexanediol.

(Example 4) Dye: "Eisen Primula Red 4BH" [made by Eisen Co., Ltd.] 3.77 parts by weight Dye: "Eisen Primula Yellow GCLH" [made by Eisen Co., Ltd.] 0.23 parts by weight Organic solvent: Propylene glycol 30.00 parts by weight pH adjuster: Triethanolamine 0.01 parts by weight Antibacterial agent: Sodium benzoate 1.22 parts by weight 1,4-Cyclohexanediol 10.00 parts by weight Water 54.77 parts by weight Parts A red ink was obtained by mixing and pulverizing the above components and then filtering. (Comparative Example 4) A red ink was obtained in the same manner as in Example 4 except that water was used instead of 1,4-cyclohexanediol.

Each of the inks obtained in Examples and Comparative Examples was filled in an aqueous pen for fine writing (Mitsubishi PIN-103: manufactured by Mitsubishi Pencil Co., Ltd.), the cap was removed, and the ink was allowed to stand in the atmosphere at regular intervals. I wrote it by hand and measured the time until it became faint and unable to draw. As a result, the writable leaving time was 5 minutes or less in all the comparative examples, whereas the writable leaving time was extended to 60 minutes or more in all the examples.

[0018]

Since the ink composition of the present invention has excellent drying resistance, it is suitable for an aqueous pen for fine writing. When writing with the pen body filled, there are no defects such as bleeding of strokes and blurring.

Claims (1)

[Claims] 1. A water-based ink composition containing a colorant and water, containing 1,4-cyclohexanediol.