JPS6031871B2 - green ink composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink used in an inkjet printing system, and particularly to an ink composition suitable for printing on the surfaces of fruits, eggs, etc.

The ink used in the inkjet method has certain conditions such as viscosity, surface tension, resistivity, and specific gravity, and must exhibit certain values.

Viscosity (2000) 1~Pillow p Resistivity 10000・Surface tension 50~6 Hit 1/Yellow specific gravity
0.8 - 1.2 Inkjet recording involves equipment parts that come into contact with the ink, and ink that does not come into contact with the printed material is automatically collected and reused from a collection tank, so there is no loss of solvent due to evaporation and ink loss. Water-based inks have been mainly used because they require replenishment.

However, when used for printing on the surface of fruits, eggs, etc., the ink itself must be in a complete solution state.
It is necessary to be compatible with water. It must also be relatively insoluble or water resistant when dry. The inks that have been used so far are improved versions of traditional water-based inks; their composition is basically the same as, for example, water-based inks for writing or felt-bens, and they are non-volatile at room temperature to prevent clogging. In addition, a solvent and the like are added. The purpose of the present invention is to provide an ink that makes it possible to print on the surface of unprocessed foods such as fruits and eggs. However, with conventional inks, the surface of fruits, eggs, etc.
Furthermore, it could not be used with confidence from the standpoint of safety and hygiene, and no ink was available that could be printed using the inkjet method.

The present invention has been developed based on consideration of these points, and is an ink that simply adheres to the surface of the object to be printed without causing any change, and has good adhesion and excellent water resistance.
Our objective is to provide ink that has extremely excellent performance in terms of safety and health. A feature of the present invention is an ink composition containing the following as essential components of the ink. {1} Shellac that can be diluted with water and is soluble in alcohol (
In particular, binders consisting of white lac, a natural resin) and morpholin fatty acid salts.

[2} Copper chlorophyllin sodium as a coloring agent.

Sodium iron chlorophyllin. [3' A diluent that is mostly water and contains a small amount of alcohol.

White lac is a colorless resin made by bleaching serrac (a natural resin extracted from lac scale insects).

This substance itself is soluble in alcohol and does not dissolve in water.
However, when mixed with morpholine fatty acid salt, it becomes water-soluble and becomes an alkaline aqueous solution. After drying, the white lac and morpholin separate, resulting in a water-tight coating. Drying properties can be increased by increasing the ratio of alcohol to water. However, if the amount of alcohol is too large, the surface tension will decrease. In addition, the flash point of the ink decreases, which is not desirable from a safety standpoint.
A suitable alcohol to water ratio is 0 to 2 parts by weight. It is also necessary that the amount of binder be 25% or less with respect to the solvent consisting of alcohol and water. This is because as the amount of binder increases, the viscosity exceeds &p,
This is not covered by the ink of the present invention. Since the viscosity increases as the temperature decreases, the amount of binder is preferably 10% or less. The coloring agents copper chlorophyllin sodium and iron chlorophyllin sodium are derivatives of chlorophyll, respectively, and are water-soluble, but do not bleed in acidic conditions.

Both are heat stable and can be used. The above-mentioned dyes are usually used in the form of an aqueous solution made alkaline using soda carbonate. The amount dissolved in water is 1 to 3% by weight,
Powdered dyes can also be dissolved in the coexistence of the above-mentioned sodium carbonate. In this case, the pH is adjusted to about 9.0 to 10.0. The above-mentioned dye exhibits a deep green color, and sodium iron chlorophyll in particular has a gradation tone, and is suitable for printing with a dark background color. The above configuration constitutes a water-based ink made of shellac.

Examples will be described in detail below. Example 1 White lac aqueous solution (transparent white lac, morpholine fatty acid salt, 25
% aqueous solution, BM-25 Fruit surface treatment base, manufactured by Gifu Shellac Seisakusho ■ 2 parts by weight Copper chlorophyllin sodium aqueous solution (Takeda Pharmaceutical 1% aqueous solution) pHIO. 0
75 parts by weight ethyl alcohol (99.
5% purity) 1 part by weight are mixed well and filtered through a 0.2ッ filter.

The obtained ink composition exhibited a viscosity of $p, a surface tension of 39 yn/d, and a resistivity of 7,500 at 20 qo. Further, when printing was performed using a Hitachi industrial marking device (DP-2), good date printing was achieved. Example 2 The following composition is printed in the same manner as in Example 1.

Claims (1)

[Claims] 1. In the inkjet recording ink, the binder is shellac, the shellac is water-solubilized with morpholine, and contains a solvent consisting of water and alcohol, and sodium iron chlorophyllin or (and) sodium copper chlorophyllin as a coloring agent. , a green ink composition having a pH of 9.0 to 10.5.