JPH0794625B2 - 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 black ink composition having excellent dispersion stability and mainly used for calligraphy. If you describe this in detail, while maintaining dispersion stability for a long period of time, it is possible to write at the same concentration without diluting, and when writing with light ink diluted with water, "clear base line" and "beautiful" The present invention relates to a black ink composition having excellent characteristics such as "bleeding".

[0002]

2. Description of the Related Art At present, liquid black ink for calligraphy (hereinafter referred to as ink), which is commercially available in liquid form, is prepared by kneading a black pigment represented by carbon black with an aqueous solution of glue or other water-soluble resin. If necessary, a surfactant, a preservative, and other additives are added thereto, and carbon black is dispersed by using a dispersing device such as a roller. The carbon black particles dispersed in the ink are
Generally, particles having various particle sizes are mixed and dispersed, from fine particles having a particle diameter of about 0.05 μm to coarse particles of about 0.5 μm. However, conventionally, in 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 "beautiful 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 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 scouring liquid than with the India ink because the dispersed carbon black has a relatively wide particle size distribution (particle size is from about 0.05 μm to 5 μm).
This is because the distribution up to about m is shown. Even if India ink with a particle size distribution similar to that of a polishing liquid is produced, coarse particles of the forcibly dispersed carbon black tend to settle quickly, and only fine particles or a water-soluble resin or a dispersant can be used for stable long-term fine particles. It was difficult to mix the same with coarse particles, and it was very difficult to obtain the same "clear base line" and "beautiful bleeding" as with the ink with ink.

[0003]

[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. The object of the present invention is to add to the carbon black a particle size adjusting agent such as activated carbon or the like consisting of particles having a particle size similar to that of the coarse particles of carbon black or having a slightly larger particle size, and thereby the particle size of the fine particles and coarse particles The purpose of the present invention is to obtain India ink which has a controlled distribution and yet retains a viscosity that facilitates writing. At this time, the particle size regulator, which is a coarse particle component,
Along with the coarse particles of carbon black, clay minerals with smectite structure and synthetic products with similar properties are used to maintain thixotropic properties so that they do not settle for a long period of time. The aim is to provide India ink that is stable for a long period of time and has a particle size distribution equivalent to that of the ink solution.

[0004]

[Means for Solving the Problems] The inventors of the present invention have found that the long-term dispersion stability of India ink and the "clear baseline" at the time of printing with light ink.
In order to obtain a "beautiful bleeding", a traditional black ink composition consisting of carbon black, a water-soluble resin, a surfactant, and water is used, and in addition, activated carbon, a metal compound, graphite or various shaped particles of a polymer are selected. The inventors have found a method of adding one or more kinds of grain size controlling agents and a clay mineral having a smectite structure as an anti-settling agent. That is, the particle size of carbon black (0.1 to 0.
By adding a particle size regulator having a particle size of about the same as or slightly larger than 5 μm), it becomes possible to impart the “clear base line” and “beautiful bleeding” similar to those of the ink solution.
As shown in the crystal structure diagram of (FIG. 1), the smectite structure is a single crystal composed of three layers having a tetrahedral silicic acid layer on the outer side and an octahedral hydrated oxide layer on the central part. It has the structural formula shown in 1). The cations between each layer are easily exchanged with other cations in water, and in water, they are swollen by water molecules to expand the interlayer distance, and the dispersion has the ability to form a colloidal solution or a thixotropic gel. And found that it can impart dispersion stability for a long time,
The present invention has been completed.

The present invention comprises carbon black, a water-soluble resin,
An ink composition comprising a surfactant and water, and a particle size adjusting agent for forming particles having a particle size similar to or slightly larger than the coarse particles of carbon black, and / or an anti-settling agent. The present invention relates to a black ink composition. The present invention relates to a India ink composition comprising, as a particle size controlling agent, one or more kinds selected from activated carbon, metal compounds, graphite or various shaped particles of polymers, and further a clay mineral having a smectite structure as an anti-settling agent.

The present invention will be described in detail below. The carbon black used in the present invention is used as a colorant, and any of commercially available pigment carbon black or carbon black for rubber can be used, and channel black,
It is not limited to furnace black and distinction between acidity and alkalinity. Specifically, MA-10
0, MA-7 (above, Mitsubishi Kasei Co., Ltd.), Special Black-5, Printex-30 (above, DEGUS
SA made) etc. In addition, oil smoke or pine smoke obtained by burning natural oil or pine resin can be used in the same manner. The amount used varies depending on the type of carbon black, but is 3 to 20% by weight with respect to the total amount of the ink composition.
If it is less than 3% by weight or exceeds 20% by weight, it cannot be practically used as India ink. A preferred composition is 8-12% by weight.

The water-soluble resin used in the present invention acts as a dispersion stabilizer and a fixing agent for carbon black, and is a conventionally used natural product such as glue or gelatin, or a synthetic product such as polyvinyl alcohol or polyvinylpyrrolidone. It is possible to use a resin. The amount used is 1 to 15% by weight based on the total amount of the ink composition. If it is less than 1% by weight, it is difficult to maintain the stability as ink,
When it exceeds, the viscosity increases and the ink cannot be used as India ink, so 2 to 5% by weight is a preferable composition.

As the surfactant used in the present invention, known anionic, nonionic or cationic surfactants can be used, and the purpose of use thereof is to assist dispersion stability in a water-soluble resin solution. There is. It may be either a natural product or a synthetic product having surface-active ability, but from the viewpoint of mold development and putrefaction, a synthetic anionic or nonionic product is preferable. The amount used is 0.1 with respect to the total amount of the ink composition.
It may be up to 5% by weight.

Activated carbon, metal compounds used in the present invention,
The particle size regulator selected from graphite and various shaped particles of polymer is a particle having a particle size similar to or slightly larger than the coarse particles of carbon black, and obtains particles corresponding to the coarse particles of the scouring liquid. It has a purpose. The activated carbon is Kuraray Coal PW, the same PK, the same YP (manufactured by Kuraray Chemical Co., Ltd.), and the metal compound is Titanium Black 20M.
(Mitsubishi Metals Co., Ltd.), aluminum paste 500W, 70
0W (Nakatsuka Metal Foil & Powder Co., Ltd.), Aluminum powder 4L
12, the same No. 1000 (Japan Metal Powder Co., Ltd.) and the like are graphite, Hitasol GP-60, the same GP-82 (Hitachi Powder Metallurgical Co., Ltd.), Fine Powder SGP-5, SGO-.
1 (Co., Ltd.) and the like, EPOCOLOR BP-1002, the same BP-1004,
Examples thereof include CX-0504 (Nippon Shokubai Co., Ltd.).
And the particle size of them is suitably about 0.5 to 5 μm, and the amount used is preferably 0.1 to 5% by weight with respect to the total amount of the ink composition. If it is 0.1% by weight or less, a "clear base line" cannot be obtained, and if it is 5% by weight or more, stable dispersion cannot be maintained and sedimentation occurs.

The clay mineral having a smectite structure used in the present invention has the structural formula shown in (Chemical formula 1) and the crystal structure shown in (FIG. 1). Due to its crystal structure, cations between each layer are easily exchanged with other cations in water, and in water, swelling by water molecules expands the interlayer distance and disperses to form a colloidal solution or thixotropic gel. It is used to maintain dispersion stability for a long time. Clay minerals having a smectite structure include dioctahedral and trioctahedral, and dioctahedral include bentonite, montmorillonite, beidellite and nontronite, and trioctahedral include laponite, hectorite and saponite, etc. In addition, synthetic products having a structure similar to those natural products have been synthesized. Products include Wenger and Wenger-HV
(Toyojun Yoko Co., Ltd.), Laponite B (Nippon Silica Industry Co., Ltd.), etc., and any of them can be used. The amount used is 1 to 20 with respect to the total amount of the ink composition.
Weight percent is preferred. If it is less than 1% by weight, the dispersion stability cannot be maintained, and if it is more than 20% by weight, it loses fluidity and is unsuitable as ink.

Next, the embodiment will be described more specifically.
The term “part” simply means “part by weight”. The present invention is not limited to these examples, and it is possible to add an antiseptic, a fragrance and other additives as needed.

[0012]

【Example】

 (Example 1) MA-100 (carbon black, manufactured by Mitsubishi Kasei Co., Ltd.) 10.0 parts Polyvinylpyrrolidone (manufactured by BASF) 3.0 parts Demol N (anionic surfactant, manufactured by Kao Co., Ltd.) 2. 0 parts Bengel (bentonite, manufactured by Toyojun Yoko Co., Ltd.) 1.5 parts Kuraray Coal YP (activated carbon, manufactured by Kuraray Chemical Co., Ltd.) 1.0 parts Water 82.5 parts

Example 2 MA-100 (carbon black, manufactured by Mitsubishi Kasei Co., Ltd.) 7.0 parts Polyvinyl alcohol (manufactured by Shin-Etsu Chemical Co., Ltd.) 2.5 parts Emulgen (nonionic activator, Kao Corporation) ) 2.0 parts Laponite B (Laponite, manufactured by Toyojun Yoko Co., Ltd.) 2.0 parts Kuraray Coal PW (activated carbon, Kuraray Chemical Co., Ltd.) 1.2 parts Water 85.3 parts

(Example 3) MA-100 (carbon black, 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) 2.0 parts Bengel (bentonite, manufactured by Toyojun Yoko Co., Ltd.) 2.0 parts Epocolor BP (black spherical polymer, manufactured by Nippon Shokubai Co., Ltd.) 1.5 parts water 85.0 parts

Comparative Example 1 MA-100 (carbon black, 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 for preliminary kneading, and then forced kneading was repeated several times using a roll mill, and the residue was left in the resulting paste. Water was added to obtain the desired sumi-juice composition.
In this case, the desired India ink can also be obtained by dispersing and mixing with a dispersing machine such as a bead mill or a homomixer.

[0017]

The inks obtained in Examples 1 to 3 and Comparative Example 1 were tested for "stability" after standing for 24 months and "baseline" and "bleeding" when copied on calligraphy paper. The comparison results are shown in (Table 1).

[0018]

[Table 1]

As for the evaluation method, "stability" is as follows.
The state of dispersion immediately after the production was visually confirmed with a microscope, and after standing at room temperature for 24 months, the precipitation of coarse particles was confirmed by filtration. Regarding the "baseline" and "bleeding", the ink obtained in the present invention was diluted about 50 times with water, and it was written on a calligraphy paper and evaluated. With respect to the "base line", it was visually confirmed whether or not the handwriting part appeared clearly, and with respect to the "bleeding", it was evenly spread from the base line, and it was visually confirmed whether or not a three-dimensional bleeding appeared.

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

Evaluation of Baseline ⊚ indicates that the boundary between the baseline and bleeding 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 described above, the ink composition according to the present invention is adjusted to have a particle size adjusted by the addition of an anti-settling agent to have a particle size of the same or slightly larger than that of carbon black particles and coarse particles of carbon black. The agent has excellent properties such that long-term dispersion stability can be obtained, and a "clear base line" and "beautiful bleeding" can be obtained when copied by hand.

[Brief description of drawings]

FIG. 1 is a crystal structure diagram of a clayey mineral having a smectite structure.

[Explanation of symbols]

 1 oxygen 2 silicon 3 hydroxyl group 4 magnesium and lithium 5 sodium ion

Claims (1)

[Claims] 1. A black ink composition comprising carbon black, a water-soluble resin, a surfactant and water, and one or more particle sizes selected from activated carbon, metal compounds, graphite and various shaped particles of polymers. A black ink composition comprising a regulator and / or a clay mineral having a smectite structure shown below as an anti-settling agent. [Chemical 1]