JPH07188597A - Indian ink composition - Google Patents

Abstract

PURPOSE:To obtain an Indian ink composition excellent in long-term dispersion stability and capable of being used for writing without diluting it by using an acidic carbon black in combination with a basic carbon black as pigments, a protective colloid, a surfactant and water as the main components. CONSTITUTION:This Indian ink composition contains an acidic carbon black and a basic carbon black in combination as pigments in an amount of 4.0 to 20.0wt.% in total, preferably in a ratio of 1:0.01 to 1:5.0. Further, this ink composition contains preferably 2.0 to 5.0wt.% protective colloid (e.g. a water-soluble resin such as gelatin or PVA) and preferably 0.1 to 5.0wt.% surfactant (preferably an anionic surfactant or a nonionic surfactant) and water as the main components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a black ink composition having excellent dispersion stability and mainly used for calligraphy. More specifically, it retains dispersion stability for a long period of time, and it can be printed at the same concentration without dilution, and when it is printed with light ink diluted with water, it has a "clear base line" and "beautiful bleeding". The present invention relates to a black ink composition having excellent characteristics such as ".

[0002]

2. Description of the Related Art At present, liquid ink for calligraphy (hereinafter referred to as "ink juice") sold in liquid form is obtained by kneading a black pigment represented by carbon black with an aqueous solution of glue or other water-soluble resin. , If necessary, surfactant, preservative,
Other additives are added, and carbon black is dispersed by using a dispersing device such as a roller. As the carbon black as a colorant, it is common to use a single carbon black or a mixture of a plurality of carbon blacks having the same hydrogen ion concentration in the same region. Generally, the smaller the particle size of these inks, the less problems such as sedimentation occur, and in order to maintain long-term storage stability, fine particles of about 0.05 μm to about 0.5 μm are generally dispersed. It was target. However, in traditional calligraphy, it is better to use a black ink obtained by brushing solid black ink with ink (hereinafter referred to as a black ink) rather than using a black ink. It is said that "bleeding" can be obtained. The "base line" here means the handwriting part at the time of writing (the base line becomes clearer when writing with light ink), and the "bleeding" means the state in which the fine particles of the colorant exude outside the base line. is there. It is easier to obtain a "clear base line" or "beautiful bleeding" with the scented liquid than with the India ink because the dispersed carbon black has a relatively wide particle size distribution (particle size from about 0.05 μm to about 5 μm). This is because the distribution is shown).

In order to produce India ink having a particle size distribution similar to that of the ink, the normally dispersed India ink is frozen to cause dispersion destruction. The normally dispersed India ink is heated for a long time at high temperature to cause dispersion destruction. Ink using an anionic activator as a dispersion aid and ink using a cationic activator as a dispersion aid are liquid-liquid mixed. There are methods such as liquid-liquid mixing of acidic India ink and basic India ink, but all of them are costly and it is difficult to control the dispersion state. Even if it is attempted to control by dispersion, among the carbon black forcibly dispersed, coarse particles tend to settle quickly, and it is difficult to mix fine particles and coarse particles stably for a long time only with glue or a water-soluble resin or a dispersant. At the same time, it was very difficult to obtain the "clear base line" and "beautiful bleeding" similar to that of the ink with ink.

[0004]

[Problems to be Solved by the Invention] It is difficult to control the degree of dispersion even if a surfactant is used in order to produce India ink having a "clear base line" and "beautiful bleeding". In addition, in order to prevent the sedimentation of coarse particles contained in India ink, high-viscosity India ink is generally prepared. However, as the viscosity increases, "easy to write", that is, writing performance decreases, so use The need arises to dilute with water. An object of the present invention is to control the particle size distribution of fine particles and coarse particles by utilizing the agglomeration reaction of carbon black generated by mixing and using two or more kinds of carbon black having different properties, and to make the viscosity easy to write. In order to obtain India ink having a weak flocculation between the particles of carbon black in order to retain the ink, the present invention is intended to provide India ink that is stable for a long period of time and has a particle size distribution equivalent to that of a polishing liquid. To do.

[0005]

[Means for Solving the Problems] In order to obtain a "clear base line" and "beautiful bleeding" at the time of writing ink with light ink, the inventors of the present invention have the same particle size distribution as ink liquid. I found the following method to get the. One of the methods is to knead and disperse two or more kinds of carbon black having different properties from the beginning and other components, and as another method, India ink in which carbon black and other components are mixed and dispersed. There are two methods which are obtained by mixing carbon black having a property different from that of the above carbon black and other components and mixing the dispersed ink. In either case, the electric double layer of the carbon black particles and the protective colloid component on the surface of the carbon black particles is destroyed by the difference in surface potential between the carbon black particles having different properties and the amount of carbon black added excessively. The inventors have found that an agglomeration reaction occurs in an equimolar ratio and the width of the particle size distribution can be made larger than that of India ink, and the present invention has been completed. The term "other components" as used herein means components other than carbon black necessary for producing India ink, that is, a water-soluble resin as a protective colloid, a surfactant, and other additives.

The carbon blacks having different properties used in the present invention have different hydrogen ion concentrations, and mean acidic carbon black and basic carbon black. By utilizing the agglomeration reaction of carbon black generated by mixing and using two or more kinds of carbon black having different hydrogen ion concentrations, the particle size distribution of fine particles and coarse particles is adjusted by changing the addition amount of each. In addition, in order to keep the viscosity that is easy to write, ink ink having weak flocculation between carbon black particles is to be obtained.

More specifically, the relationship between the agglutination reaction and the mixing ratio of carbon blacks having different hydrogen ion concentrations is as follows.
When the amount of acidic carbon black (or basic carbon black) used is 1.0, when carbon black having opposite hydrogen ion concentrations is added in a range of 0.01 to 5.0, the same amount is equimolar. Causes a coagulation reaction to form particles larger than the excessively added carbon black particles, and has a particle size distribution equivalent to that of a cleaning liquid, and it is possible to obtain a "clear base line" and "beautiful bleeding". Regarding the width of the particle size distribution, the particle size generated by the agglutination reaction can be adjusted by the mixing ratio of the two or more kinds of hydrogen black having the opposite hydrogen ion concentrations which are used at first. That is, it is possible to control the particle size distribution within a certain range between the particle size generated by the agglomeration reaction that has proceeded in an equimolar ratio and the particle size at the time of addition that does not cause the agglomeration reaction. The agglutination reaction is completed in a few hours to a few days, depending on the reaction conditions after the production of India ink, and no progress is observed thereafter.

The present invention will be described in detail below. The carbon black used in the present invention is used as a colorant, and any commercially available carbon black for coloring or carbon black for rubber can be used, and it is limited by a difference in manufacturing method such as channel black, furnace black, etc. It is not a matter of course, but it must be a combination of acidic carbon black and basic carbon black in which the hydrogen ion concentrations are contradictory. Specific examples of the acidic carbon black include MA-7 and MA-10.
0, # 970, # 2200, # 2600 [above, manufactured by Mitsubishi Kasei Co., Ltd.], Special Black-5, Special Black 100, Color Black S-170, Printex 140V [above, manufactured by Degussa Japan Co., Ltd.],
There are Neo Spectra Mark 5, Neo Spectra Mark 1 [above, Columbian Carbon Japan Co., Ltd.] and the like.
Further, as a specific example of the basic carbon black, #
5, # 40, # 960, # 2300 [above, manufactured by Mitsubishi Kasei Co., Ltd.], Printex 90, Printex G,
Printex 45, Printex L [above, manufactured by Degussa Japan Co., Ltd.], RAVEN420, RAVEN
H20 POWDER [above, Columbyan Carbon Japan Co., Ltd.] and the like. Furthermore, oil smoke and pine smoke obtained by burning natural oil, pine resin, etc. can be similarly used. Although the amount used varies depending on the type of carbon black, the total amount of acidic carbon black and basic carbon black is 4.0 to 20.0% by weight based on the total amount of the final ink composition. If it is less than 0.0% by weight or 20.0% by weight or more, the aggregation reaction is difficult to occur or the aggregation reaction proceeds too much to be practical as ink, and 5.0 to 10.0% by weight is a preferable composition. Further, it is most effective to use the carbon black having a contradictory hydrogen ion concentration in a mixing ratio of 1: 0.01 to 1: 5.0.

The water-soluble resin as a protective colloid used in the present invention is used as a dispersion stabilizer and a fixing agent for carbon black. Natural products such as glue and gelatin and polyvinyl alcohol, which have been conventionally used, It is possible to use synthetic resins such as polyvinylpyrrolidone, water-soluble acrylic, acrylamide, vinylpyridine and polyacrylic acid. The amount of the ink used is 1.0 to 15.0% by weight based on the total amount of the ink composition. If it is less than 1.0% by weight, it is difficult to maintain the stability of the ink.
When it exceeds 0% by weight, the viscosity increases and it cannot be used as ink, so 2.0 to 5.0% by weight is a preferable composition.

As the surfactant used in the present invention, known anionic, nonionic or cationic surfactants can be used, the purpose of which is to assist dispersion stability in a water-soluble polymer solution. It has an effect. Either a natural product or a synthetic product having a surface-active property may be used, but the synthetic anion-based or nonionic-based product is most suitable from the viewpoint of mold development and decay. The amount used is based on the total amount of the ink composition.
0.1 to 5.0% by weight is preferable.

Next, the embodiment will be described more specifically.
"Parts" simply means "parts by weight", and "carbon" means "carbon black". The present invention is
It is not limited in any way by this example, and it is also possible to appropriately add an antiseptic agent, a moistening agent, a freeze stabilizer, an antifoaming agent, a perfume, and other additives, if necessary.

[0012]

Examples (Example 1) MA-100 [acidic carbon, manufactured by Mitsubishi Kasei Co., Ltd.] 5.0 parts # 5 [basic carbon, manufactured by Mitsubishi Kasei Co., Ltd.] 1.0 part Polyvinylpyrrolidone [BASF ( Co., Ltd.] 3.0 parts Demol N [anionic surfactant, manufactured by Kao Corporation] 2.0 parts Water 89.0 parts

(Example 2) MA-100 [acidic carbon, manufactured by Mitsubishi Kasei Co., Ltd.] 7.0 parts Printex 45 [basic carbon, manufactured by Degussa Co., Ltd.] 6.0 parts Polyvinyl alcohol [Shin-Etsu Chemical ( Co., Ltd.] 2.5 parts Emulgen [nonionic surfactant, manufactured by Kao Co., Ltd.] 2.0 parts Water 82.5 parts

(Example 3) Special black # 5 [acidic carbon, manufactured by Degussa Co., Ltd.] 0.5 part Printex 90 [basic carbon, manufactured by Degussa Co., Ltd.] 6.0 parts Polyvinyl alcohol [Shin-Etsu Chemical ( Co., Ltd.] 2.5 parts Demol N [anionic surfactant, Kao Co., Ltd.] 1.0 part Water 90.0 parts

(Example 4) MA-100 [acidic carbon, manufactured by Mitsubishi Kasei Co., Ltd.] 7.0 parts Polyvinyl alcohol [manufactured by Shin-Etsu Chemical Co., Ltd.] 2.5 parts Demol N [anionic surfactant, Kao] Co., Ltd.] 2.0 parts Water 88.5 parts Let the above-mentioned India ink composition be (A). Printex 45 [basic carbon, manufactured by Degussa Co., Ltd.] 7.0 parts Polyvinyl alcohol [manufactured by Shin-Etsu Chemical Co., Ltd.] 2.5 parts Demol N [anionic surfactant, manufactured by Kao Co., Ltd.] 2.0 Part water 88.5 parts Let the above-mentioned India ink composition be (B). The above ink composition (A)
And (B) the above ink composition.

Comparative Example 1 MA-100 [acidic carbon, manufactured by Mitsubishi Kasei Co., Ltd.] 7.0 parts Polyvinyl alcohol [manufactured by Shin-Etsu Chemical Co., Ltd.] 2.5 parts Demol N [anionic surfactant, Kao] Co., Ltd.] 2.0 parts Water 88.5 parts

A part of a predetermined amount of water was added to the formulations of Examples 1 to 3 and Comparative Example 1 to pre-knead them, and then forced kneading was repeated several times using a roll mill to leave a residue in the resulting paste. Water was added to obtain the desired sumi-juice composition.
For Example 4, after adding a predetermined amount of water to each formulation and pre-kneading, forced kneading was repeated several times using a roll mill, and the remaining water was added to the obtained paste. After preparing the India ink composition, the liquids (A) and (B) were mixed with a stirrer to obtain the intended India ink composition. Example 1
In any case of 4, the target India ink can be obtained by dispersing and mixing with a dispersing machine such as a bead mill or a homomixer.

[0018]

EFFECTS OF THE INVENTION The inks obtained in Examples 1 to 4 and Comparative Example 1 were tested for "stability" after standing for 24 months and "baseline" and "bleeding" when copied on calligraphy half-paper. The comparison results are shown in Table 1.

[0019]

[Table 1]

As for the evaluation method, "stability" is as follows.
The state of dispersion immediately after production was visually confirmed with a microscope, and after standing in a standard state for 24 months, the precipitation of coarse particles was confirmed by filtration. Regarding the "base line" and "bleeding", the ink obtained in the present invention was diluted about 50 times with water, and was copied on calligraphy paper for evaluation. Regarding the "baseline", check whether the handwriting part is clearly visible,
In regard to the above, it was visually confirmed whether the spread spreads uniformly from the base line and a blur with a three-dimensional effect appears.

Stability evaluation ⊚ indicates that there is no precipitate and the dispersion is kept uniform. ○
Has some soft precipitate, but can be dispersed uniformly by stirring. × indicates that the particles have agglomerated and do not disperse even if they are stirred again.

Evaluation of Base Line ◎ indicates that the boundary between the base line and the blur is clear. ○: The boundary between the baseline and the blur is slightly unclear. × indicates that the boundary between the baseline and the blur is unclear.

Evaluation of bleeding ◎ indicates that bleeding is uniform and has a three-dimensional effect. ○ indicates that the bleeding is uniform. × indicates that the bleeding is uneven.

As explained above, the ink composition according to the present invention is a mixture of two or more kinds of carbon blacks having different hydrogen ion concentrations, namely acidic carbon black and basic carbon black. By utilizing the aggregating action of carbon black generated when carbon blacks with different hydrogen ion concentrations are used together, the particle size distribution between fine particles and coarse particles is adjusted, and yet the viscosity between the carbon particles is weak in order to maintain a viscosity that is easy to write. The purpose is to obtain ink with flocculation. The agglomeration action that occurs here is that the equivalent amount of carbon black added excessively causes an agglomeration action in an equimolar ratio, and the action stops at a certain place, so it is stable for a long period of time and has a particle size equivalent to that of a cleaning liquid. It has the excellent properties of being able to obtain India ink with a distribution and obtaining a "clear base line" and "beautiful bleeding" when it is copied with a handwriting.

Claims (1)

[Claims] 1. A India ink composition comprising a pigment, a protective colloid, a surfactant and water as main components, wherein acidic carbon black and basic carbon black are used in combination as the pigment.